fs/ext4/extents.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com
   4  * Written by Alex Tomas <alex@clusterfs.com>
   5  *
   6  * Architecture independence:
   7  *   Copyright (c) 2005, Bull S.A.
   8  *   Written by Pierre Peiffer <pierre.peiffer@bull.net>
   9  */
  10
  11 /*
  12  * Extents support for EXT4
  13  *
  14  * TODO:
  15  *   - ext4*_error() should be used in some situations
  16  *   - analyze all BUG()/BUG_ON(), use -EIO where appropriate
  17  *   - smart tree reduction
  18  */
  19
  20 #include <linux/fs.h>
  21 #include <linux/time.h>
  22 #include <linux/jbd2.h>
  23 #include <linux/highuid.h>
  24 #include <linux/pagemap.h>
  25 #include <linux/quotaops.h>
  26 #include <linux/string.h>
  27 #include <linux/slab.h>
  28 #include <linux/uaccess.h>
  29 #include <linux/fiemap.h>
  30 #include <linux/iomap.h>
  31 #include <linux/sched/mm.h>
  32 #include "ext4_jbd2.h"
  33 #include "ext4_extents.h"
  34 #include "xattr.h"
  35
  36 #include <trace/events/ext4.h>
  37
  38 /*
  39  * used by extent splitting.
  40  */
  41 #define EXT4_EXT_MAY_ZEROOUT    0x1  /* safe to zeroout if split fails \
  42                                         due to ENOSPC */
  43 #define EXT4_EXT_MARK_UNWRIT1   0x2  /* mark first half unwritten */
  44 #define EXT4_EXT_MARK_UNWRIT2   0x4  /* mark second half unwritten */
  45
  46 #define EXT4_EXT_DATA_VALID1    0x8  /* first half contains valid data */
  47 #define EXT4_EXT_DATA_VALID2    0x10 /* second half contains valid data */
  48
  49 static __le32 ext4_extent_block_csum(struct inode *inode,
  50                                      struct ext4_extent_header *eh)
  51 {
  52         struct ext4_inode_info *ei = EXT4_I(inode);
  53         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
  54         __u32 csum;
  55
  56         csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)eh,
  57                            EXT4_EXTENT_TAIL_OFFSET(eh));
  58         return cpu_to_le32(csum);
  59 }
  60
  61 static int ext4_extent_block_csum_verify(struct inode *inode,
  62                                          struct ext4_extent_header *eh)
  63 {
  64         struct ext4_extent_tail *et;
  65
  66         if (!ext4_has_metadata_csum(inode->i_sb))
  67                 return 1;
  68
  69         et = find_ext4_extent_tail(eh);
  70         if (et->et_checksum != ext4_extent_block_csum(inode, eh))
  71                 return 0;
  72         return 1;
  73 }
  74
  75 static void ext4_extent_block_csum_set(struct inode *inode,
  76                                        struct ext4_extent_header *eh)
  77 {
  78         struct ext4_extent_tail *et;
  79
  80         if (!ext4_has_metadata_csum(inode->i_sb))
  81                 return;
  82
  83         et = find_ext4_extent_tail(eh);
  84         et->et_checksum = ext4_extent_block_csum(inode, eh);
  85 }
  86
  87 static int ext4_split_extent_at(handle_t *handle,
  88                              struct inode *inode,
  89                              struct ext4_ext_path **ppath,
  90                              ext4_lblk_t split,
  91                              int split_flag,
  92                              int flags);
  93
  94 static int ext4_ext_trunc_restart_fn(struct inode *inode, int *dropped)
  95 {
  96         /*
  97          * Drop i_data_sem to avoid deadlock with ext4_map_blocks.  At this
  98          * moment, get_block can be called only for blocks inside i_size since
  99          * page cache has been already dropped and writes are blocked by
 100          * i_rwsem. So we can safely drop the i_data_sem here.
 101          */
 102         BUG_ON(EXT4_JOURNAL(inode) == NULL);
 103         ext4_discard_preallocations(inode, 0);
 104         up_write(&EXT4_I(inode)->i_data_sem);
 105         *dropped = 1;
 106         return 0;
 107 }
 108
 109 static void ext4_ext_drop_refs(struct ext4_ext_path *path)
 110 {
 111         int depth, i;
 112
 113         if (!path)
 114                 return;
 115         depth = path->p_depth;
 116         for (i = 0; i <= depth; i++, path++) {
 117                 brelse(path->p_bh);
 118                 path->p_bh = NULL;
 119         }
 120 }
 121
 122 void ext4_free_ext_path(struct ext4_ext_path *path)
 123 {
 124         ext4_ext_drop_refs(path);
 125         kfree(path);
 126 }
 127
 128 /*
 129  * Make sure 'handle' has at least 'check_cred' credits. If not, restart
 130  * transaction with 'restart_cred' credits. The function drops i_data_sem
 131  * when restarting transaction and gets it after transaction is restarted.
 132  *
 133  * The function returns 0 on success, 1 if transaction had to be restarted,
 134  * and < 0 in case of fatal error.
 135  */
 136 int ext4_datasem_ensure_credits(handle_t *handle, struct inode *inode,
 137                                 int check_cred, int restart_cred,
 138                                 int revoke_cred)
 139 {
 140         int ret;
 141         int dropped = 0;
 142
 143         ret = ext4_journal_ensure_credits_fn(handle, check_cred, restart_cred,
 144                 revoke_cred, ext4_ext_trunc_restart_fn(inode, &dropped));
 145         if (dropped)
 146                 down_write(&EXT4_I(inode)->i_data_sem);
 147         return ret;
 148 }
 149
 150 /*
 151  * could return:
 152  *  - EROFS
 153  *  - ENOMEM
 154  */
 155 static int ext4_ext_get_access(handle_t *handle, struct inode *inode,
 156                                 struct ext4_ext_path *path)
 157 {
 158         int err = 0;
 159
 160         if (path->p_bh) {
 161                 /* path points to block */
 162                 BUFFER_TRACE(path->p_bh, "get_write_access");
 163                 err = ext4_journal_get_write_access(handle, inode->i_sb,
 164                                                     path->p_bh, EXT4_JTR_NONE);
 165                 /*
 166                  * The extent buffer's verified bit will be set again in
 167                  * __ext4_ext_dirty(). We could leave an inconsistent
 168                  * buffer if the extents updating procudure break off du
 169                  * to some error happens, force to check it again.
 170                  */
 171                 if (!err)
 172                         clear_buffer_verified(path->p_bh);
 173         }
 174         /* path points to leaf/index in inode body */
 175         /* we use in-core data, no need to protect them */
 176         return err;
 177 }
 178
 179 /*
 180  * could return:
 181  *  - EROFS
 182  *  - ENOMEM
 183  *  - EIO
 184  */
 185 static int __ext4_ext_dirty(const char *where, unsigned int line,
 186                             handle_t *handle, struct inode *inode,
 187                             struct ext4_ext_path *path)
 188 {
 189         int err;
 190
 191         WARN_ON(!rwsem_is_locked(&EXT4_I(inode)->i_data_sem));
 192         if (path->p_bh) {
 193                 ext4_extent_block_csum_set(inode, ext_block_hdr(path->p_bh));
 194                 /* path points to block */
 195                 err = __ext4_handle_dirty_metadata(where, line, handle,
 196                                                    inode, path->p_bh);
 197                 /* Extents updating done, re-set verified flag */
 198                 if (!err)
 199                         set_buffer_verified(path->p_bh);
 200         } else {
 201                 /* path points to leaf/index in inode body */
 202                 err = ext4_mark_inode_dirty(handle, inode);
 203         }
 204         return err;
 205 }
 206
 207 #define ext4_ext_dirty(handle, inode, path) \
 208                 __ext4_ext_dirty(__func__, __LINE__, (handle), (inode), (path))
 209
 210 static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode,
 211                               struct ext4_ext_path *path,
 212                               ext4_lblk_t block)
 213 {
 214         if (path) {
 215                 int depth = path->p_depth;
 216                 struct ext4_extent *ex;
 217
 218                 /*
 219                  * Try to predict block placement assuming that we are
 220                  * filling in a file which will eventually be
 221                  * non-sparse --- i.e., in the case of libbfd writing
 222                  * an ELF object sections out-of-order but in a way
 223                  * the eventually results in a contiguous object or
 224                  * executable file, or some database extending a table
 225                  * space file.  However, this is actually somewhat
 226                  * non-ideal if we are writing a sparse file such as
 227                  * qemu or KVM writing a raw image file that is going
 228                  * to stay fairly sparse, since it will end up
 229                  * fragmenting the file system's free space.  Maybe we
 230                  * should have some hueristics or some way to allow
 231                  * userspace to pass a hint to file system,
 232                  * especially if the latter case turns out to be
 233                  * common.
 234                  */
 235                 ex = path[depth].p_ext;
 236                 if (ex) {
 237                         ext4_fsblk_t ext_pblk = ext4_ext_pblock(ex);
 238                         ext4_lblk_t ext_block = le32_to_cpu(ex->ee_block);
 239
 240                         if (block > ext_block)
 241                                 return ext_pblk + (block - ext_block);
 242                         else
 243                                 return ext_pblk - (ext_block - block);
 244                 }
 245
 246                 /* it looks like index is empty;
 247                  * try to find starting block from index itself */
 248                 if (path[depth].p_bh)
 249                         return path[depth].p_bh->b_blocknr;
 250         }
 251
 252         /* OK. use inode's group */
 253         return ext4_inode_to_goal_block(inode);
 254 }
 255
 256 /*
 257  * Allocation for a meta data block
 258  */
 259 static ext4_fsblk_t
 260 ext4_ext_new_meta_block(handle_t *handle, struct inode *inode,
 261                         struct ext4_ext_path *path,
 262                         struct ext4_extent *ex, int *err, unsigned int flags)
 263 {
 264         ext4_fsblk_t goal, newblock;
 265
 266         goal = ext4_ext_find_goal(inode, path, le32_to_cpu(ex->ee_block));
 267         newblock = ext4_new_meta_blocks(handle, inode, goal, flags,
 268                                         NULL, err);
 269         return newblock;
 270 }
 271
 272 static inline int ext4_ext_space_block(struct inode *inode, int check)
 273 {
 274         int size;
 275
 276         size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
 277                         / sizeof(struct ext4_extent);
 278 #ifdef AGGRESSIVE_TEST
 279         if (!check && size > 6)
 280                 size = 6;
 281 #endif
 282         return size;
 283 }
 284
 285 static inline int ext4_ext_space_block_idx(struct inode *inode, int check)
 286 {
 287         int size;
 288
 289         size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
 290                         / sizeof(struct ext4_extent_idx);
 291 #ifdef AGGRESSIVE_TEST
 292         if (!check && size > 5)
 293                 size = 5;
 294 #endif
 295         return size;
 296 }
 297
 298 static inline int ext4_ext_space_root(struct inode *inode, int check)
 299 {
 300         int size;
 301
 302         size = sizeof(EXT4_I(inode)->i_data);
 303         size -= sizeof(struct ext4_extent_header);
 304         size /= sizeof(struct ext4_extent);
 305 #ifdef AGGRESSIVE_TEST
 306         if (!check && size > 3)
 307                 size = 3;
 308 #endif
 309         return size;
 310 }
 311
 312 static inline int ext4_ext_space_root_idx(struct inode *inode, int check)
 313 {
 314         int size;
 315
 316         size = sizeof(EXT4_I(inode)->i_data);
 317         size -= sizeof(struct ext4_extent_header);
 318         size /= sizeof(struct ext4_extent_idx);
 319 #ifdef AGGRESSIVE_TEST
 320         if (!check && size > 4)
 321                 size = 4;
 322 #endif
 323         return size;
 324 }
 325
 326 static inline int
 327 ext4_force_split_extent_at(handle_t *handle, struct inode *inode,
 328                            struct ext4_ext_path **ppath, ext4_lblk_t lblk,
 329                            int nofail)
 330 {
 331         struct ext4_ext_path *path = *ppath;
 332         int unwritten = ext4_ext_is_unwritten(path[path->p_depth].p_ext);
 333         int flags = EXT4_EX_NOCACHE | EXT4_GET_BLOCKS_PRE_IO;
 334
 335         if (nofail)
 336                 flags |= EXT4_GET_BLOCKS_METADATA_NOFAIL | EXT4_EX_NOFAIL;
 337
 338         return ext4_split_extent_at(handle, inode, ppath, lblk, unwritten ?
 339                         EXT4_EXT_MARK_UNWRIT1|EXT4_EXT_MARK_UNWRIT2 : 0,
 340                         flags);
 341 }
 342
 343 static int
 344 ext4_ext_max_entries(struct inode *inode, int depth)
 345 {
 346         int max;
 347
 348         if (depth == ext_depth(inode)) {
 349                 if (depth == 0)
 350                         max = ext4_ext_space_root(inode, 1);
 351                 else
 352                         max = ext4_ext_space_root_idx(inode, 1);
 353         } else {
 354                 if (depth == 0)
 355                         max = ext4_ext_space_block(inode, 1);
 356                 else
 357                         max = ext4_ext_space_block_idx(inode, 1);
 358         }
 359
 360         return max;
 361 }
 362
 363 static int ext4_valid_extent(struct inode *inode, struct ext4_extent *ext)
 364 {
 365         ext4_fsblk_t block = ext4_ext_pblock(ext);
 366         int len = ext4_ext_get_actual_len(ext);
 367         ext4_lblk_t lblock = le32_to_cpu(ext->ee_block);
 368
 369         /*
 370          * We allow neither:
 371          *  - zero length
 372          *  - overflow/wrap-around
 373          */
 374         if (lblock + len <= lblock)
 375                 return 0;
 376         return ext4_inode_block_valid(inode, block, len);
 377 }
 378
 379 static int ext4_valid_extent_idx(struct inode *inode,
 380                                 struct ext4_extent_idx *ext_idx)
 381 {
 382         ext4_fsblk_t block = ext4_idx_pblock(ext_idx);
 383
 384         return ext4_inode_block_valid(inode, block, 1);
 385 }
 386
 387 static int ext4_valid_extent_entries(struct inode *inode,
 388                                      struct ext4_extent_header *eh,
 389                                      ext4_lblk_t lblk, ext4_fsblk_t *pblk,
 390                                      int depth)
 391 {
 392         unsigned short entries;
 393         ext4_lblk_t lblock = 0;
 394         ext4_lblk_t cur = 0;
 395
 396         if (eh->eh_entries == 0)
 397                 return 1;
 398
 399         entries = le16_to_cpu(eh->eh_entries);
 400
 401         if (depth == 0) {
 402                 /* leaf entries */
 403                 struct ext4_extent *ext = EXT_FIRST_EXTENT(eh);
 404
 405                 /*
 406                  * The logical block in the first entry should equal to
 407                  * the number in the index block.
 408                  */
 409                 if (depth != ext_depth(inode) &&
 410                     lblk != le32_to_cpu(ext->ee_block))
 411                         return 0;
 412                 while (entries) {
 413                         if (!ext4_valid_extent(inode, ext))
 414                                 return 0;
 415
 416                         /* Check for overlapping extents */
 417                         lblock = le32_to_cpu(ext->ee_block);
 418                         if (lblock < cur) {
 419                                 *pblk = ext4_ext_pblock(ext);
 420                                 return 0;
 421                         }
 422                         cur = lblock + ext4_ext_get_actual_len(ext);
 423                         ext++;
 424                         entries--;
 425                 }
 426         } else {
 427                 struct ext4_extent_idx *ext_idx = EXT_FIRST_INDEX(eh);
 428
 429                 /*
 430                  * The logical block in the first entry should equal to
 431                  * the number in the parent index block.
 432                  */
 433                 if (depth != ext_depth(inode) &&
 434                     lblk != le32_to_cpu(ext_idx->ei_block))
 435                         return 0;
 436                 while (entries) {
 437                         if (!ext4_valid_extent_idx(inode, ext_idx))
 438                                 return 0;
 439
 440                         /* Check for overlapping index extents */
 441                         lblock = le32_to_cpu(ext_idx->ei_block);
 442                         if (lblock < cur) {
 443                                 *pblk = ext4_idx_pblock(ext_idx);
 444                                 return 0;
 445                         }
 446                         ext_idx++;
 447                         entries--;
 448                         cur = lblock + 1;
 449                 }
 450         }
 451         return 1;
 452 }
 453
 454 static int __ext4_ext_check(const char *function, unsigned int line,
 455                             struct inode *inode, struct ext4_extent_header *eh,
 456                             int depth, ext4_fsblk_t pblk, ext4_lblk_t lblk)
 457 {
 458         const char *error_msg;
 459         int max = 0, err = -EFSCORRUPTED;
 460
 461         if (unlikely(eh->eh_magic != EXT4_EXT_MAGIC)) {
 462                 error_msg = "invalid magic";
 463                 goto corrupted;
 464         }
 465         if (unlikely(le16_to_cpu(eh->eh_depth) != depth)) {
 466                 error_msg = "unexpected eh_depth";
 467                 goto corrupted;
 468         }
 469         if (unlikely(eh->eh_max == 0)) {
 470                 error_msg = "invalid eh_max";
 471                 goto corrupted;
 472         }
 473         max = ext4_ext_max_entries(inode, depth);
 474         if (unlikely(le16_to_cpu(eh->eh_max) > max)) {
 475                 error_msg = "too large eh_max";
 476                 goto corrupted;
 477         }
 478         if (unlikely(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max))) {
 479                 error_msg = "invalid eh_entries";
 480                 goto corrupted;
 481         }
 482         if (unlikely((eh->eh_entries == 0) && (depth > 0))) {
 483                 error_msg = "eh_entries is 0 but eh_depth is > 0";
 484                 goto corrupted;
 485         }
 486         if (!ext4_valid_extent_entries(inode, eh, lblk, &pblk, depth)) {
 487                 error_msg = "invalid extent entries";
 488                 goto corrupted;
 489         }
 490         if (unlikely(depth > 32)) {
 491                 error_msg = "too large eh_depth";
 492                 goto corrupted;
 493         }
 494         /* Verify checksum on non-root extent tree nodes */
 495         if (ext_depth(inode) != depth &&
 496             !ext4_extent_block_csum_verify(inode, eh)) {
 497                 error_msg = "extent tree corrupted";
 498                 err = -EFSBADCRC;
 499                 goto corrupted;
 500         }
 501         return 0;
 502
 503 corrupted:
 504         ext4_error_inode_err(inode, function, line, 0, -err,
 505                              "pblk %llu bad header/extent: %s - magic %x, "
 506                              "entries %u, max %u(%u), depth %u(%u)",
 507                              (unsigned long long) pblk, error_msg,
 508                              le16_to_cpu(eh->eh_magic),
 509                              le16_to_cpu(eh->eh_entries),
 510                              le16_to_cpu(eh->eh_max),
 511                              max, le16_to_cpu(eh->eh_depth), depth);
 512         return err;
 513 }
 514
 515 #define ext4_ext_check(inode, eh, depth, pblk)                  \
 516         __ext4_ext_check(__func__, __LINE__, (inode), (eh), (depth), (pblk), 0)
 517
 518 int ext4_ext_check_inode(struct inode *inode)
 519 {
 520         return ext4_ext_check(inode, ext_inode_hdr(inode), ext_depth(inode), 0);
 521 }
 522
 523 static void ext4_cache_extents(struct inode *inode,
 524                                struct ext4_extent_header *eh)
 525 {
 526         struct ext4_extent *ex = EXT_FIRST_EXTENT(eh);
 527         ext4_lblk_t prev = 0;
 528         int i;
 529
 530         for (i = le16_to_cpu(eh->eh_entries); i > 0; i--, ex++) {
 531                 unsigned int status = EXTENT_STATUS_WRITTEN;
 532                 ext4_lblk_t lblk = le32_to_cpu(ex->ee_block);
 533                 int len = ext4_ext_get_actual_len(ex);
 534
 535                 if (prev && (prev != lblk))
 536                         ext4_es_cache_extent(inode, prev, lblk - prev, ~0,
 537                                              EXTENT_STATUS_HOLE);
 538
 539                 if (ext4_ext_is_unwritten(ex))
 540                         status = EXTENT_STATUS_UNWRITTEN;
 541                 ext4_es_cache_extent(inode, lblk, len,
 542                                      ext4_ext_pblock(ex), status);
 543                 prev = lblk + len;
 544         }
 545 }
 546
 547 static struct buffer_head *
 548 __read_extent_tree_block(const char *function, unsigned int line,
 549                          struct inode *inode, struct ext4_extent_idx *idx,
 550                          int depth, int flags)
 551 {
 552         struct buffer_head              *bh;
 553         int                             err;
 554         gfp_t                           gfp_flags = __GFP_MOVABLE | GFP_NOFS;
 555         ext4_fsblk_t                    pblk;
 556
 557         if (flags & EXT4_EX_NOFAIL)
 558                 gfp_flags |= __GFP_NOFAIL;
 559
 560         pblk = ext4_idx_pblock(idx);
 561         bh = sb_getblk_gfp(inode->i_sb, pblk, gfp_flags);
 562         if (unlikely(!bh))
 563                 return ERR_PTR(-ENOMEM);
 564
 565         if (!bh_uptodate_or_lock(bh)) {
 566                 trace_ext4_ext_load_extent(inode, pblk, _RET_IP_);
 567                 err = ext4_read_bh(bh, 0, NULL);
 568                 if (err < 0)
 569                         goto errout;
 570         }
 571         if (buffer_verified(bh) && !(flags & EXT4_EX_FORCE_CACHE))
 572                 return bh;
 573         err = __ext4_ext_check(function, line, inode, ext_block_hdr(bh),
 574                                depth, pblk, le32_to_cpu(idx->ei_block));
 575         if (err)
 576                 goto errout;
 577         set_buffer_verified(bh);
 578         /*
 579          * If this is a leaf block, cache all of its entries
 580          */
 581         if (!(flags & EXT4_EX_NOCACHE) && depth == 0) {
 582                 struct ext4_extent_header *eh = ext_block_hdr(bh);
 583                 ext4_cache_extents(inode, eh);
 584         }
 585         return bh;
 586 errout:
 587         put_bh(bh);
 588         return ERR_PTR(err);
 589
 590 }
 591
 592 #define read_extent_tree_block(inode, idx, depth, flags)                \
 593         __read_extent_tree_block(__func__, __LINE__, (inode), (idx),    \
 594                                  (depth), (flags))
 595
 596 /*
 597  * This function is called to cache a file's extent information in the
 598  * extent status tree
 599  */
 600 int ext4_ext_precache(struct inode *inode)
 601 {
 602         struct ext4_inode_info *ei = EXT4_I(inode);
 603         struct ext4_ext_path *path = NULL;
 604         struct buffer_head *bh;
 605         int i = 0, depth, ret = 0;
 606
 607         if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
 608                 return 0;       /* not an extent-mapped inode */
 609
 610         down_read(&ei->i_data_sem);
 611         depth = ext_depth(inode);
 612
 613         /* Don't cache anything if there are no external extent blocks */
 614         if (!depth) {
 615                 up_read(&ei->i_data_sem);
 616                 return ret;
 617         }
 618
 619         path = kcalloc(depth + 1, sizeof(struct ext4_ext_path),
 620                        GFP_NOFS);
 621         if (path == NULL) {
 622                 up_read(&ei->i_data_sem);
 623                 return -ENOMEM;
 624         }
 625
 626         path[0].p_hdr = ext_inode_hdr(inode);
 627         ret = ext4_ext_check(inode, path[0].p_hdr, depth, 0);
 628         if (ret)
 629                 goto out;
 630         path[0].p_idx = EXT_FIRST_INDEX(path[0].p_hdr);
 631         while (i >= 0) {
 632                 /*
 633                  * If this is a leaf block or we've reached the end of
 634                  * the index block, go up
 635                  */
 636                 if ((i == depth) ||
 637                     path[i].p_idx > EXT_LAST_INDEX(path[i].p_hdr)) {
 638                         brelse(path[i].p_bh);
 639                         path[i].p_bh = NULL;
 640                         i--;
 641                         continue;
 642                 }
 643                 bh = read_extent_tree_block(inode, path[i].p_idx++,
 644                                             depth - i - 1,
 645                                             EXT4_EX_FORCE_CACHE);
 646                 if (IS_ERR(bh)) {
 647                         ret = PTR_ERR(bh);
 648                         break;
 649                 }
 650                 i++;
 651                 path[i].p_bh = bh;
 652                 path[i].p_hdr = ext_block_hdr(bh);
 653                 path[i].p_idx = EXT_FIRST_INDEX(path[i].p_hdr);
 654         }
 655         ext4_set_inode_state(inode, EXT4_STATE_EXT_PRECACHED);
 656 out:
 657         up_read(&ei->i_data_sem);
 658         ext4_free_ext_path(path);
 659         return ret;
 660 }
 661
 662 #ifdef EXT_DEBUG
 663 static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path)
 664 {
 665         int k, l = path->p_depth;
 666
 667         ext_debug(inode, "path:");
 668         for (k = 0; k <= l; k++, path++) {
 669                 if (path->p_idx) {
 670                         ext_debug(inode, "  %d->%llu",
 671                                   le32_to_cpu(path->p_idx->ei_block),
 672                                   ext4_idx_pblock(path->p_idx));
 673                 } else if (path->p_ext) {
 674                         ext_debug(inode, "  %d:[%d]%d:%llu ",
 675                                   le32_to_cpu(path->p_ext->ee_block),
 676                                   ext4_ext_is_unwritten(path->p_ext),
 677                                   ext4_ext_get_actual_len(path->p_ext),
 678                                   ext4_ext_pblock(path->p_ext));
 679                 } else
 680                         ext_debug(inode, "  []");
 681         }
 682         ext_debug(inode, "\n");
 683 }
 684
 685 static void ext4_ext_show_leaf(struct inode *inode, struct ext4_ext_path *path)
 686 {
 687         int depth = ext_depth(inode);
 688         struct ext4_extent_header *eh;
 689         struct ext4_extent *ex;
 690         int i;
 691
 692         if (!path)
 693                 return;
 694
 695         eh = path[depth].p_hdr;
 696         ex = EXT_FIRST_EXTENT(eh);
 697
 698         ext_debug(inode, "Displaying leaf extents\n");
 699
 700         for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ex++) {
 701                 ext_debug(inode, "%d:[%d]%d:%llu ", le32_to_cpu(ex->ee_block),
 702                           ext4_ext_is_unwritten(ex),
 703                           ext4_ext_get_actual_len(ex), ext4_ext_pblock(ex));
 704         }
 705         ext_debug(inode, "\n");
 706 }
 707
 708 static void ext4_ext_show_move(struct inode *inode, struct ext4_ext_path *path,
 709                         ext4_fsblk_t newblock, int level)
 710 {
 711         int depth = ext_depth(inode);
 712         struct ext4_extent *ex;
 713
 714         if (depth != level) {
 715                 struct ext4_extent_idx *idx;
 716                 idx = path[level].p_idx;
 717                 while (idx <= EXT_MAX_INDEX(path[level].p_hdr)) {
 718                         ext_debug(inode, "%d: move %d:%llu in new index %llu\n",
 719                                   level, le32_to_cpu(idx->ei_block),
 720                                   ext4_idx_pblock(idx), newblock);
 721                         idx++;
 722                 }
 723
 724                 return;
 725         }
 726
 727         ex = path[depth].p_ext;
 728         while (ex <= EXT_MAX_EXTENT(path[depth].p_hdr)) {
 729                 ext_debug(inode, "move %d:%llu:[%d]%d in new leaf %llu\n",
 730                                 le32_to_cpu(ex->ee_block),
 731                                 ext4_ext_pblock(ex),
 732                                 ext4_ext_is_unwritten(ex),
 733                                 ext4_ext_get_actual_len(ex),
 734                                 newblock);
 735                 ex++;
 736         }
 737 }
 738
 739 #else
 740 #define ext4_ext_show_path(inode, path)
 741 #define ext4_ext_show_leaf(inode, path)
 742 #define ext4_ext_show_move(inode, path, newblock, level)
 743 #endif
 744
 745 /*
 746  * ext4_ext_binsearch_idx:
 747  * binary search for the closest index of the given block
 748  * the header must be checked before calling this
 749  */
 750 static void
 751 ext4_ext_binsearch_idx(struct inode *inode,
 752                         struct ext4_ext_path *path, ext4_lblk_t block)
 753 {
 754         struct ext4_extent_header *eh = path->p_hdr;
 755         struct ext4_extent_idx *r, *l, *m;
 756
 757
 758         ext_debug(inode, "binsearch for %u(idx):  ", block);
 759
 760         l = EXT_FIRST_INDEX(eh) + 1;
 761         r = EXT_LAST_INDEX(eh);
 762         while (l <= r) {
 763                 m = l + (r - l) / 2;
 764                 ext_debug(inode, "%p(%u):%p(%u):%p(%u) ", l,
 765                           le32_to_cpu(l->ei_block), m, le32_to_cpu(m->ei_block),
 766                           r, le32_to_cpu(r->ei_block));
 767
 768                 if (block < le32_to_cpu(m->ei_block))
 769                         r = m - 1;
 770                 else
 771                         l = m + 1;
 772         }
 773
 774         path->p_idx = l - 1;
 775         ext_debug(inode, "  -> %u->%lld ", le32_to_cpu(path->p_idx->ei_block),
 776                   ext4_idx_pblock(path->p_idx));
 777
 778 #ifdef CHECK_BINSEARCH
 779         {
 780                 struct ext4_extent_idx *chix, *ix;
 781                 int k;
 782
 783                 chix = ix = EXT_FIRST_INDEX(eh);
 784                 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ix++) {
 785                         if (k != 0 && le32_to_cpu(ix->ei_block) <=
 786                             le32_to_cpu(ix[-1].ei_block)) {
 787                                 printk(KERN_DEBUG "k=%d, ix=0x%p, "
 788                                        "first=0x%p\n", k,
 789                                        ix, EXT_FIRST_INDEX(eh));
 790                                 printk(KERN_DEBUG "%u <= %u\n",
 791                                        le32_to_cpu(ix->ei_block),
 792                                        le32_to_cpu(ix[-1].ei_block));
 793                         }
 794                         BUG_ON(k && le32_to_cpu(ix->ei_block)
 795                                            <= le32_to_cpu(ix[-1].ei_block));
 796                         if (block < le32_to_cpu(ix->ei_block))
 797                                 break;
 798                         chix = ix;
 799                 }
 800                 BUG_ON(chix != path->p_idx);
 801         }
 802 #endif
 803
 804 }
 805
 806 /*
 807  * ext4_ext_binsearch:
 808  * binary search for closest extent of the given block
 809  * the header must be checked before calling this
 810  */
 811 static void
 812 ext4_ext_binsearch(struct inode *inode,
 813                 struct ext4_ext_path *path, ext4_lblk_t block)
 814 {
 815         struct ext4_extent_header *eh = path->p_hdr;
 816         struct ext4_extent *r, *l, *m;
 817
 818         if (eh->eh_entries == 0) {
 819                 /*
 820                  * this leaf is empty:
 821                  * we get such a leaf in split/add case
 822                  */
 823                 return;
 824         }
 825
 826         ext_debug(inode, "binsearch for %u:  ", block);
 827
 828         l = EXT_FIRST_EXTENT(eh) + 1;
 829         r = EXT_LAST_EXTENT(eh);
 830
 831         while (l <= r) {
 832                 m = l + (r - l) / 2;
 833                 ext_debug(inode, "%p(%u):%p(%u):%p(%u) ", l,
 834                           le32_to_cpu(l->ee_block), m, le32_to_cpu(m->ee_block),
 835                           r, le32_to_cpu(r->ee_block));
 836
 837                 if (block < le32_to_cpu(m->ee_block))
 838                         r = m - 1;
 839                 else
 840                         l = m + 1;
 841         }
 842
 843         path->p_ext = l - 1;
 844         ext_debug(inode, "  -> %d:%llu:[%d]%d ",
 845                         le32_to_cpu(path->p_ext->ee_block),
 846                         ext4_ext_pblock(path->p_ext),
 847                         ext4_ext_is_unwritten(path->p_ext),
 848                         ext4_ext_get_actual_len(path->p_ext));
 849
 850 #ifdef CHECK_BINSEARCH
 851         {
 852                 struct ext4_extent *chex, *ex;
 853                 int k;
 854
 855                 chex = ex = EXT_FIRST_EXTENT(eh);
 856                 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ex++) {
 857                         BUG_ON(k && le32_to_cpu(ex->ee_block)
 858                                           <= le32_to_cpu(ex[-1].ee_block));
 859                         if (block < le32_to_cpu(ex->ee_block))
 860                                 break;
 861                         chex = ex;
 862                 }
 863                 BUG_ON(chex != path->p_ext);
 864         }
 865 #endif
 866
 867 }
 868
 869 void ext4_ext_tree_init(handle_t *handle, struct inode *inode)
 870 {
 871         struct ext4_extent_header *eh;
 872
 873         eh = ext_inode_hdr(inode);
 874         eh->eh_depth = 0;
 875         eh->eh_entries = 0;
 876         eh->eh_magic = EXT4_EXT_MAGIC;
 877         eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode, 0));
 878         eh->eh_generation = 0;
 879         ext4_mark_inode_dirty(handle, inode);
 880 }
 881
 882 struct ext4_ext_path *
 883 ext4_find_extent(struct inode *inode, ext4_lblk_t block,
 884                  struct ext4_ext_path **orig_path, int flags)
 885 {
 886         struct ext4_extent_header *eh;
 887         struct buffer_head *bh;
 888         struct ext4_ext_path *path = orig_path ? *orig_path : NULL;
 889         short int depth, i, ppos = 0;
 890         int ret;
 891         gfp_t gfp_flags = GFP_NOFS;
 892
 893         if (flags & EXT4_EX_NOFAIL)
 894                 gfp_flags |= __GFP_NOFAIL;
 895
 896         eh = ext_inode_hdr(inode);
 897         depth = ext_depth(inode);
 898         if (depth < 0 || depth > EXT4_MAX_EXTENT_DEPTH) {
 899                 EXT4_ERROR_INODE(inode, "inode has invalid extent depth: %d",
 900                                  depth);
 901                 ret = -EFSCORRUPTED;
 902                 goto err;
 903         }
 904
 905         if (path) {
 906                 ext4_ext_drop_refs(path);
 907                 if (depth > path[0].p_maxdepth) {
 908                         kfree(path);
 909                         *orig_path = path = NULL;
 910                 }
 911         }
 912         if (!path) {
 913                 /* account possible depth increase */
 914                 path = kcalloc(depth + 2, sizeof(struct ext4_ext_path),
 915                                 gfp_flags);
 916                 if (unlikely(!path))
 917                         return ERR_PTR(-ENOMEM);
 918                 path[0].p_maxdepth = depth + 1;
 919         }
 920         path[0].p_hdr = eh;
 921         path[0].p_bh = NULL;
 922
 923         i = depth;
 924         if (!(flags & EXT4_EX_NOCACHE) && depth == 0)
 925                 ext4_cache_extents(inode, eh);
 926         /* walk through the tree */
 927         while (i) {
 928                 ext_debug(inode, "depth %d: num %d, max %d\n",
 929                           ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
 930
 931                 ext4_ext_binsearch_idx(inode, path + ppos, block);
 932                 path[ppos].p_block = ext4_idx_pblock(path[ppos].p_idx);
 933                 path[ppos].p_depth = i;
 934                 path[ppos].p_ext = NULL;
 935
 936                 bh = read_extent_tree_block(inode, path[ppos].p_idx, --i, flags);
 937                 if (IS_ERR(bh)) {
 938                         ret = PTR_ERR(bh);
 939                         goto err;
 940                 }
 941
 942                 eh = ext_block_hdr(bh);
 943                 ppos++;
 944                 path[ppos].p_bh = bh;
 945                 path[ppos].p_hdr = eh;
 946         }
 947
 948         path[ppos].p_depth = i;
 949         path[ppos].p_ext = NULL;
 950         path[ppos].p_idx = NULL;
 951
 952         /* find extent */
 953         ext4_ext_binsearch(inode, path + ppos, block);
 954         /* if not an empty leaf */
 955         if (path[ppos].p_ext)
 956                 path[ppos].p_block = ext4_ext_pblock(path[ppos].p_ext);
 957
 958         ext4_ext_show_path(inode, path);
 959
 960         return path;
 961
 962 err:
 963         ext4_free_ext_path(path);
 964         if (orig_path)
 965                 *orig_path = NULL;
 966         return ERR_PTR(ret);
 967 }
 968
 969 /*
 970  * ext4_ext_insert_index:
 971  * insert new index [@logical;@ptr] into the block at @curp;
 972  * check where to insert: before @curp or after @curp
 973  */
 974 static int ext4_ext_insert_index(handle_t *handle, struct inode *inode,
 975                                  struct ext4_ext_path *curp,
 976                                  int logical, ext4_fsblk_t ptr)
 977 {
 978         struct ext4_extent_idx *ix;
 979         int len, err;
 980
 981         err = ext4_ext_get_access(handle, inode, curp);
 982         if (err)
 983                 return err;
 984
 985         if (unlikely(logical == le32_to_cpu(curp->p_idx->ei_block))) {
 986                 EXT4_ERROR_INODE(inode,
 987                                  "logical %d == ei_block %d!",
 988                                  logical, le32_to_cpu(curp->p_idx->ei_block));
 989                 return -EFSCORRUPTED;
 990         }
 991
 992         if (unlikely(le16_to_cpu(curp->p_hdr->eh_entries)
 993                              >= le16_to_cpu(curp->p_hdr->eh_max))) {
 994                 EXT4_ERROR_INODE(inode,
 995                                  "eh_entries %d >= eh_max %d!",
 996                                  le16_to_cpu(curp->p_hdr->eh_entries),
 997                                  le16_to_cpu(curp->p_hdr->eh_max));
 998                 return -EFSCORRUPTED;
 999         }
1000
1001         if (logical > le32_to_cpu(curp->p_idx->ei_block)) {
1002                 /* insert after */
1003                 ext_debug(inode, "insert new index %d after: %llu\n",
1004                           logical, ptr);
1005                 ix = curp->p_idx + 1;
1006         } else {
1007                 /* insert before */
1008                 ext_debug(inode, "insert new index %d before: %llu\n",
1009                           logical, ptr);
1010                 ix = curp->p_idx;
1011         }
1012
1013         if (unlikely(ix > EXT_MAX_INDEX(curp->p_hdr))) {
1014                 EXT4_ERROR_INODE(inode, "ix > EXT_MAX_INDEX!");
1015                 return -EFSCORRUPTED;
1016         }
1017
1018         len = EXT_LAST_INDEX(curp->p_hdr) - ix + 1;
1019         BUG_ON(len < 0);
1020         if (len > 0) {
1021                 ext_debug(inode, "insert new index %d: "
1022                                 "move %d indices from 0x%p to 0x%p\n",
1023                                 logical, len, ix, ix + 1);
1024                 memmove(ix + 1, ix, len * sizeof(struct ext4_extent_idx));
1025         }
1026
1027         ix->ei_block = cpu_to_le32(logical);
1028         ext4_idx_store_pblock(ix, ptr);
1029         le16_add_cpu(&curp->p_hdr->eh_entries, 1);
1030
1031         if (unlikely(ix > EXT_LAST_INDEX(curp->p_hdr))) {
1032                 EXT4_ERROR_INODE(inode, "ix > EXT_LAST_INDEX!");
1033                 return -EFSCORRUPTED;
1034         }
1035
1036         err = ext4_ext_dirty(handle, inode, curp);
1037         ext4_std_error(inode->i_sb, err);
1038
1039         return err;
1040 }
1041
1042 /*
1043  * ext4_ext_split:
1044  * inserts new subtree into the path, using free index entry
1045  * at depth @at:
1046  * - allocates all needed blocks (new leaf and all intermediate index blocks)
1047  * - makes decision where to split
1048  * - moves remaining extents and index entries (right to the split point)
1049  *   into the newly allocated blocks
1050  * - initializes subtree
1051  */
1052 static int ext4_ext_split(handle_t *handle, struct inode *inode,
1053                           unsigned int flags,
1054                           struct ext4_ext_path *path,
1055                           struct ext4_extent *newext, int at)
1056 {
1057         struct buffer_head *bh = NULL;
1058         int depth = ext_depth(inode);
1059         struct ext4_extent_header *neh;
1060         struct ext4_extent_idx *fidx;
1061         int i = at, k, m, a;
1062         ext4_fsblk_t newblock, oldblock;
1063         __le32 border;
1064         ext4_fsblk_t *ablocks = NULL; /* array of allocated blocks */
1065         gfp_t gfp_flags = GFP_NOFS;
1066         int err = 0;
1067         size_t ext_size = 0;
1068
1069         if (flags & EXT4_EX_NOFAIL)
1070                 gfp_flags |= __GFP_NOFAIL;
1071
1072         /* make decision: where to split? */
1073         /* FIXME: now decision is simplest: at current extent */
1074
1075         /* if current leaf will be split, then we should use
1076          * border from split point */
1077         if (unlikely(path[depth].p_ext > EXT_MAX_EXTENT(path[depth].p_hdr))) {
1078                 EXT4_ERROR_INODE(inode, "p_ext > EXT_MAX_EXTENT!");
1079                 return -EFSCORRUPTED;
1080         }
1081         if (path[depth].p_ext != EXT_MAX_EXTENT(path[depth].p_hdr)) {
1082                 border = path[depth].p_ext[1].ee_block;
1083                 ext_debug(inode, "leaf will be split."
1084                                 " next leaf starts at %d\n",
1085                                   le32_to_cpu(border));
1086         } else {
1087                 border = newext->ee_block;
1088                 ext_debug(inode, "leaf will be added."
1089                                 " next leaf starts at %d\n",
1090                                 le32_to_cpu(border));
1091         }
1092
1093         /*
1094          * If error occurs, then we break processing
1095          * and mark filesystem read-only. index won't
1096          * be inserted and tree will be in consistent
1097          * state. Next mount will repair buffers too.
1098          */
1099
1100         /*
1101          * Get array to track all allocated blocks.
1102          * We need this to handle errors and free blocks
1103          * upon them.
1104          */
1105         ablocks = kcalloc(depth, sizeof(ext4_fsblk_t), gfp_flags);
1106         if (!ablocks)
1107                 return -ENOMEM;
1108
1109         /* allocate all needed blocks */
1110         ext_debug(inode, "allocate %d blocks for indexes/leaf\n", depth - at);
1111         for (a = 0; a < depth - at; a++) {
1112                 newblock = ext4_ext_new_meta_block(handle, inode, path,
1113                                                    newext, &err, flags);
1114                 if (newblock == 0)
1115                         goto cleanup;
1116                 ablocks[a] = newblock;
1117         }
1118
1119         /* initialize new leaf */
1120         newblock = ablocks[--a];
1121         if (unlikely(newblock == 0)) {
1122                 EXT4_ERROR_INODE(inode, "newblock == 0!");
1123                 err = -EFSCORRUPTED;
1124                 goto cleanup;
1125         }
1126         bh = sb_getblk_gfp(inode->i_sb, newblock, __GFP_MOVABLE | GFP_NOFS);
1127         if (unlikely(!bh)) {
1128                 err = -ENOMEM;
1129                 goto cleanup;
1130         }
1131         lock_buffer(bh);
1132
1133         err = ext4_journal_get_create_access(handle, inode->i_sb, bh,
1134                                              EXT4_JTR_NONE);
1135         if (err)
1136                 goto cleanup;
1137
1138         neh = ext_block_hdr(bh);
1139         neh->eh_entries = 0;
1140         neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
1141         neh->eh_magic = EXT4_EXT_MAGIC;
1142         neh->eh_depth = 0;
1143         neh->eh_generation = 0;
1144
1145         /* move remainder of path[depth] to the new leaf */
1146         if (unlikely(path[depth].p_hdr->eh_entries !=
1147                      path[depth].p_hdr->eh_max)) {
1148                 EXT4_ERROR_INODE(inode, "eh_entries %d != eh_max %d!",
1149                                  path[depth].p_hdr->eh_entries,
1150                                  path[depth].p_hdr->eh_max);
1151                 err = -EFSCORRUPTED;
1152                 goto cleanup;
1153         }
1154         /* start copy from next extent */
1155         m = EXT_MAX_EXTENT(path[depth].p_hdr) - path[depth].p_ext++;
1156         ext4_ext_show_move(inode, path, newblock, depth);
1157         if (m) {
1158                 struct ext4_extent *ex;
1159                 ex = EXT_FIRST_EXTENT(neh);
1160                 memmove(ex, path[depth].p_ext, sizeof(struct ext4_extent) * m);
1161                 le16_add_cpu(&neh->eh_entries, m);
1162         }
1163
1164         /* zero out unused area in the extent block */
1165         ext_size = sizeof(struct ext4_extent_header) +
1166                 sizeof(struct ext4_extent) * le16_to_cpu(neh->eh_entries);
1167         memset(bh->b_data + ext_size, 0, inode->i_sb->s_blocksize - ext_size);
1168         ext4_extent_block_csum_set(inode, neh);
1169         set_buffer_uptodate(bh);
1170         unlock_buffer(bh);
1171
1172         err = ext4_handle_dirty_metadata(handle, inode, bh);
1173         if (err)
1174                 goto cleanup;
1175         brelse(bh);
1176         bh = NULL;
1177
1178         /* correct old leaf */
1179         if (m) {
1180                 err = ext4_ext_get_access(handle, inode, path + depth);
1181                 if (err)
1182                         goto cleanup;
1183                 le16_add_cpu(&path[depth].p_hdr->eh_entries, -m);
1184                 err = ext4_ext_dirty(handle, inode, path + depth);
1185                 if (err)
1186                         goto cleanup;
1187
1188         }
1189
1190         /* create intermediate indexes */
1191         k = depth - at - 1;
1192         if (unlikely(k < 0)) {
1193                 EXT4_ERROR_INODE(inode, "k %d < 0!", k);
1194                 err = -EFSCORRUPTED;
1195                 goto cleanup;
1196         }
1197         if (k)
1198                 ext_debug(inode, "create %d intermediate indices\n", k);
1199         /* insert new index into current index block */
1200         /* current depth stored in i var */
1201         i = depth - 1;
1202         while (k--) {
1203                 oldblock = newblock;
1204                 newblock = ablocks[--a];
1205                 bh = sb_getblk(inode->i_sb, newblock);
1206                 if (unlikely(!bh)) {
1207                         err = -ENOMEM;
1208                         goto cleanup;
1209                 }
1210                 lock_buffer(bh);
1211
1212                 err = ext4_journal_get_create_access(handle, inode->i_sb, bh,
1213                                                      EXT4_JTR_NONE);
1214                 if (err)
1215                         goto cleanup;
1216
1217                 neh = ext_block_hdr(bh);
1218                 neh->eh_entries = cpu_to_le16(1);
1219                 neh->eh_magic = EXT4_EXT_MAGIC;
1220                 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
1221                 neh->eh_depth = cpu_to_le16(depth - i);
1222                 neh->eh_generation = 0;
1223                 fidx = EXT_FIRST_INDEX(neh);
1224                 fidx->ei_block = border;
1225                 ext4_idx_store_pblock(fidx, oldblock);
1226
1227                 ext_debug(inode, "int.index at %d (block %llu): %u -> %llu\n",
1228                                 i, newblock, le32_to_cpu(border), oldblock);
1229
1230                 /* move remainder of path[i] to the new index block */
1231                 if (unlikely(EXT_MAX_INDEX(path[i].p_hdr) !=
1232                                         EXT_LAST_INDEX(path[i].p_hdr))) {
1233                         EXT4_ERROR_INODE(inode,
1234                                          "EXT_MAX_INDEX != EXT_LAST_INDEX ee_block %d!",
1235                                          le32_to_cpu(path[i].p_ext->ee_block));
1236                         err = -EFSCORRUPTED;
1237                         goto cleanup;
1238                 }
1239                 /* start copy indexes */
1240                 m = EXT_MAX_INDEX(path[i].p_hdr) - path[i].p_idx++;
1241                 ext_debug(inode, "cur 0x%p, last 0x%p\n", path[i].p_idx,
1242                                 EXT_MAX_INDEX(path[i].p_hdr));
1243                 ext4_ext_show_move(inode, path, newblock, i);
1244                 if (m) {
1245                         memmove(++fidx, path[i].p_idx,
1246                                 sizeof(struct ext4_extent_idx) * m);
1247                         le16_add_cpu(&neh->eh_entries, m);
1248                 }
1249                 /* zero out unused area in the extent block */
1250                 ext_size = sizeof(struct ext4_extent_header) +
1251                    (sizeof(struct ext4_extent) * le16_to_cpu(neh->eh_entries));
1252                 memset(bh->b_data + ext_size, 0,
1253                         inode->i_sb->s_blocksize - ext_size);
1254                 ext4_extent_block_csum_set(inode, neh);
1255                 set_buffer_uptodate(bh);
1256                 unlock_buffer(bh);
1257
1258                 err = ext4_handle_dirty_metadata(handle, inode, bh);
1259                 if (err)
1260                         goto cleanup;
1261                 brelse(bh);
1262                 bh = NULL;
1263
1264                 /* correct old index */
1265                 if (m) {
1266                         err = ext4_ext_get_access(handle, inode, path + i);
1267                         if (err)
1268                                 goto cleanup;
1269                         le16_add_cpu(&path[i].p_hdr->eh_entries, -m);
1270                         err = ext4_ext_dirty(handle, inode, path + i);
1271                         if (err)
1272                                 goto cleanup;
1273                 }
1274
1275                 i--;
1276         }
1277
1278         /* insert new index */
1279         err = ext4_ext_insert_index(handle, inode, path + at,
1280                                     le32_to_cpu(border), newblock);
1281
1282 cleanup:
1283         if (bh) {
1284                 if (buffer_locked(bh))
1285                         unlock_buffer(bh);
1286                 brelse(bh);
1287         }
1288
1289         if (err) {
1290                 /* free all allocated blocks in error case */
1291                 for (i = 0; i < depth; i++) {
1292                         if (!ablocks[i])
1293                                 continue;
1294                         ext4_free_blocks(handle, inode, NULL, ablocks[i], 1,
1295                                          EXT4_FREE_BLOCKS_METADATA);
1296                 }
1297         }
1298         kfree(ablocks);
1299
1300         return err;
1301 }
1302
1303 /*
1304  * ext4_ext_grow_indepth:
1305  * implements tree growing procedure:
1306  * - allocates new block
1307  * - moves top-level data (index block or leaf) into the new block
1308  * - initializes new top-level, creating index that points to the
1309  *   just created block
1310  */
1311 static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
1312                                  unsigned int flags)
1313 {
1314         struct ext4_extent_header *neh;
1315         struct buffer_head *bh;
1316         ext4_fsblk_t newblock, goal = 0;
1317         struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
1318         int err = 0;
1319         size_t ext_size = 0;
1320
1321         /* Try to prepend new index to old one */
1322         if (ext_depth(inode))
1323                 goal = ext4_idx_pblock(EXT_FIRST_INDEX(ext_inode_hdr(inode)));
1324         if (goal > le32_to_cpu(es->s_first_data_block)) {
1325                 flags |= EXT4_MB_HINT_TRY_GOAL;
1326                 goal--;
1327         } else
1328                 goal = ext4_inode_to_goal_block(inode);
1329         newblock = ext4_new_meta_blocks(handle, inode, goal, flags,
1330                                         NULL, &err);
1331         if (newblock == 0)
1332                 return err;
1333
1334         bh = sb_getblk_gfp(inode->i_sb, newblock, __GFP_MOVABLE | GFP_NOFS);
1335         if (unlikely(!bh))
1336                 return -ENOMEM;
1337         lock_buffer(bh);
1338
1339         err = ext4_journal_get_create_access(handle, inode->i_sb, bh,
1340                                              EXT4_JTR_NONE);
1341         if (err) {
1342                 unlock_buffer(bh);
1343                 goto out;
1344         }
1345
1346         ext_size = sizeof(EXT4_I(inode)->i_data);
1347         /* move top-level index/leaf into new block */
1348         memmove(bh->b_data, EXT4_I(inode)->i_data, ext_size);
1349         /* zero out unused area in the extent block */
1350         memset(bh->b_data + ext_size, 0, inode->i_sb->s_blocksize - ext_size);
1351
1352         /* set size of new block */
1353         neh = ext_block_hdr(bh);
1354         /* old root could have indexes or leaves
1355          * so calculate e_max right way */
1356         if (ext_depth(inode))
1357                 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
1358         else
1359                 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
1360         neh->eh_magic = EXT4_EXT_MAGIC;
1361         ext4_extent_block_csum_set(inode, neh);
1362         set_buffer_uptodate(bh);
1363         set_buffer_verified(bh);
1364         unlock_buffer(bh);
1365
1366         err = ext4_handle_dirty_metadata(handle, inode, bh);
1367         if (err)
1368                 goto out;
1369
1370         /* Update top-level index: num,max,pointer */
1371         neh = ext_inode_hdr(inode);
1372         neh->eh_entries = cpu_to_le16(1);
1373         ext4_idx_store_pblock(EXT_FIRST_INDEX(neh), newblock);
1374         if (neh->eh_depth == 0) {
1375                 /* Root extent block becomes index block */
1376                 neh->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode, 0));
1377                 EXT_FIRST_INDEX(neh)->ei_block =
1378                         EXT_FIRST_EXTENT(neh)->ee_block;
1379         }
1380         ext_debug(inode, "new root: num %d(%d), lblock %d, ptr %llu\n",
1381                   le16_to_cpu(neh->eh_entries), le16_to_cpu(neh->eh_max),
1382                   le32_to_cpu(EXT_FIRST_INDEX(neh)->ei_block),
1383                   ext4_idx_pblock(EXT_FIRST_INDEX(neh)));
1384
1385         le16_add_cpu(&neh->eh_depth, 1);
1386         err = ext4_mark_inode_dirty(handle, inode);
1387 out:
1388         brelse(bh);
1389
1390         return err;
1391 }
1392
1393 /*
1394  * ext4_ext_create_new_leaf:
1395  * finds empty index and adds new leaf.
1396  * if no free index is found, then it requests in-depth growing.
1397  */
1398 static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode,
1399                                     unsigned int mb_flags,
1400                                     unsigned int gb_flags,
1401                                     struct ext4_ext_path **ppath,
1402                                     struct ext4_extent *newext)
1403 {
1404         struct ext4_ext_path *path = *ppath;
1405         struct ext4_ext_path *curp;
1406         int depth, i, err = 0;
1407
1408 repeat:
1409         i = depth = ext_depth(inode);
1410
1411         /* walk up to the tree and look for free index entry */
1412         curp = path + depth;
1413         while (i > 0 && !EXT_HAS_FREE_INDEX(curp)) {
1414                 i--;
1415                 curp--;
1416         }
1417
1418         /* we use already allocated block for index block,
1419          * so subsequent data blocks should be contiguous */
1420         if (EXT_HAS_FREE_INDEX(curp)) {
1421                 /* if we found index with free entry, then use that
1422                  * entry: create all needed subtree and add new leaf */
1423                 err = ext4_ext_split(handle, inode, mb_flags, path, newext, i);
1424                 if (err)
1425                         goto out;
1426
1427                 /* refill path */
1428                 path = ext4_find_extent(inode,
1429                                     (ext4_lblk_t)le32_to_cpu(newext->ee_block),
1430                                     ppath, gb_flags);
1431                 if (IS_ERR(path))
1432                         err = PTR_ERR(path);
1433         } else {
1434                 /* tree is full, time to grow in depth */
1435                 err = ext4_ext_grow_indepth(handle, inode, mb_flags);
1436                 if (err)
1437                         goto out;
1438
1439                 /* refill path */
1440                 path = ext4_find_extent(inode,
1441                                    (ext4_lblk_t)le32_to_cpu(newext->ee_block),
1442                                     ppath, gb_flags);
1443                 if (IS_ERR(path)) {
1444                         err = PTR_ERR(path);
1445                         goto out;
1446                 }
1447
1448                 /*
1449                  * only first (depth 0 -> 1) produces free space;
1450                  * in all other cases we have to split the grown tree
1451                  */
1452                 depth = ext_depth(inode);
1453                 if (path[depth].p_hdr->eh_entries == path[depth].p_hdr->eh_max) {
1454                         /* now we need to split */
1455                         goto repeat;
1456                 }
1457         }
1458
1459 out:
1460         return err;
1461 }
1462
1463 /*
1464  * search the closest allocated block to the left for *logical
1465  * and returns it at @logical + it's physical address at @phys
1466  * if *logical is the smallest allocated block, the function
1467  * returns 0 at @phys
1468  * return value contains 0 (success) or error code
1469  */
1470 static int ext4_ext_search_left(struct inode *inode,
1471                                 struct ext4_ext_path *path,
1472                                 ext4_lblk_t *logical, ext4_fsblk_t *phys)
1473 {
1474         struct ext4_extent_idx *ix;
1475         struct ext4_extent *ex;
1476         int depth, ee_len;
1477
1478         if (unlikely(path == NULL)) {
1479                 EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical);
1480                 return -EFSCORRUPTED;
1481         }
1482         depth = path->p_depth;
1483         *phys = 0;
1484
1485         if (depth == 0 && path->p_ext == NULL)
1486                 return 0;
1487
1488         /* usually extent in the path covers blocks smaller
1489          * then *logical, but it can be that extent is the
1490          * first one in the file */
1491
1492         ex = path[depth].p_ext;
1493         ee_len = ext4_ext_get_actual_len(ex);
1494         if (*logical < le32_to_cpu(ex->ee_block)) {
1495                 if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) {
1496                         EXT4_ERROR_INODE(inode,
1497                                          "EXT_FIRST_EXTENT != ex *logical %d ee_block %d!",
1498                                          *logical, le32_to_cpu(ex->ee_block));
1499                         return -EFSCORRUPTED;
1500                 }
1501                 while (--depth >= 0) {
1502                         ix = path[depth].p_idx;
1503                         if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) {
1504                                 EXT4_ERROR_INODE(inode,
1505                                   "ix (%d) != EXT_FIRST_INDEX (%d) (depth %d)!",
1506                                   ix != NULL ? le32_to_cpu(ix->ei_block) : 0,
1507                                   le32_to_cpu(EXT_FIRST_INDEX(path[depth].p_hdr)->ei_block),
1508                                   depth);
1509                                 return -EFSCORRUPTED;
1510                         }
1511                 }
1512                 return 0;
1513         }
1514
1515         if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) {
1516                 EXT4_ERROR_INODE(inode,
1517                                  "logical %d < ee_block %d + ee_len %d!",
1518                                  *logical, le32_to_cpu(ex->ee_block), ee_len);
1519                 return -EFSCORRUPTED;
1520         }
1521
1522         *logical = le32_to_cpu(ex->ee_block) + ee_len - 1;
1523         *phys = ext4_ext_pblock(ex) + ee_len - 1;
1524         return 0;
1525 }
1526
1527 /*
1528  * Search the closest allocated block to the right for *logical
1529  * and returns it at @logical + it's physical address at @phys.
1530  * If not exists, return 0 and @phys is set to 0. We will return
1531  * 1 which means we found an allocated block and ret_ex is valid.
1532  * Or return a (< 0) error code.
1533  */
1534 static int ext4_ext_search_right(struct inode *inode,
1535                                  struct ext4_ext_path *path,
1536                                  ext4_lblk_t *logical, ext4_fsblk_t *phys,
1537                                  struct ext4_extent *ret_ex)
1538 {
1539         struct buffer_head *bh = NULL;
1540         struct ext4_extent_header *eh;
1541         struct ext4_extent_idx *ix;
1542         struct ext4_extent *ex;
1543         int depth;      /* Note, NOT eh_depth; depth from top of tree */
1544         int ee_len;
1545
1546         if (unlikely(path == NULL)) {
1547                 EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical);
1548                 return -EFSCORRUPTED;
1549         }
1550         depth = path->p_depth;
1551         *phys = 0;
1552
1553         if (depth == 0 && path->p_ext == NULL)
1554                 return 0;
1555
1556         /* usually extent in the path covers blocks smaller
1557          * then *logical, but it can be that extent is the
1558          * first one in the file */
1559
1560         ex = path[depth].p_ext;
1561         ee_len = ext4_ext_get_actual_len(ex);
1562         if (*logical < le32_to_cpu(ex->ee_block)) {
1563                 if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) {
1564                         EXT4_ERROR_INODE(inode,
1565                                          "first_extent(path[%d].p_hdr) != ex",
1566                                          depth);
1567                         return -EFSCORRUPTED;
1568                 }
1569                 while (--depth >= 0) {
1570                         ix = path[depth].p_idx;
1571                         if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) {
1572                                 EXT4_ERROR_INODE(inode,
1573                                                  "ix != EXT_FIRST_INDEX *logical %d!",
1574                                                  *logical);
1575                                 return -EFSCORRUPTED;
1576                         }
1577                 }
1578                 goto found_extent;
1579         }
1580
1581         if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) {
1582                 EXT4_ERROR_INODE(inode,
1583                                  "logical %d < ee_block %d + ee_len %d!",
1584                                  *logical, le32_to_cpu(ex->ee_block), ee_len);
1585                 return -EFSCORRUPTED;
1586         }
1587
1588         if (ex != EXT_LAST_EXTENT(path[depth].p_hdr)) {
1589                 /* next allocated block in this leaf */
1590                 ex++;
1591                 goto found_extent;
1592         }
1593
1594         /* go up and search for index to the right */
1595         while (--depth >= 0) {
1596                 ix = path[depth].p_idx;
1597                 if (ix != EXT_LAST_INDEX(path[depth].p_hdr))
1598                         goto got_index;
1599         }
1600
1601         /* we've gone up to the root and found no index to the right */
1602         return 0;
1603
1604 got_index:
1605         /* we've found index to the right, let's
1606          * follow it and find the closest allocated
1607          * block to the right */
1608         ix++;
1609         while (++depth < path->p_depth) {
1610                 /* subtract from p_depth to get proper eh_depth */
1611                 bh = read_extent_tree_block(inode, ix, path->p_depth - depth, 0);
1612                 if (IS_ERR(bh))
1613                         return PTR_ERR(bh);
1614                 eh = ext_block_hdr(bh);
1615                 ix = EXT_FIRST_INDEX(eh);
1616                 put_bh(bh);
1617         }
1618
1619         bh = read_extent_tree_block(inode, ix, path->p_depth - depth, 0);
1620         if (IS_ERR(bh))
1621                 return PTR_ERR(bh);
1622         eh = ext_block_hdr(bh);
1623         ex = EXT_FIRST_EXTENT(eh);
1624 found_extent:
1625         *logical = le32_to_cpu(ex->ee_block);
1626         *phys = ext4_ext_pblock(ex);
1627         if (ret_ex)
1628                 *ret_ex = *ex;
1629         if (bh)
1630                 put_bh(bh);
1631         return 1;
1632 }
1633
1634 /*
1635  * ext4_ext_next_allocated_block:
1636  * returns allocated block in subsequent extent or EXT_MAX_BLOCKS.
1637  * NOTE: it considers block number from index entry as
1638  * allocated block. Thus, index entries have to be consistent
1639  * with leaves.
1640  */
1641 ext4_lblk_t
1642 ext4_ext_next_allocated_block(struct ext4_ext_path *path)
1643 {
1644         int depth;
1645
1646         BUG_ON(path == NULL);
1647         depth = path->p_depth;
1648
1649         if (depth == 0 && path->p_ext == NULL)
1650                 return EXT_MAX_BLOCKS;
1651
1652         while (depth >= 0) {
1653                 struct ext4_ext_path *p = &path[depth];
1654
1655                 if (depth == path->p_depth) {
1656                         /* leaf */
1657                         if (p->p_ext && p->p_ext != EXT_LAST_EXTENT(p->p_hdr))
1658                                 return le32_to_cpu(p->p_ext[1].ee_block);
1659                 } else {
1660                         /* index */
1661                         if (p->p_idx != EXT_LAST_INDEX(p->p_hdr))
1662                                 return le32_to_cpu(p->p_idx[1].ei_block);
1663                 }
1664                 depth--;
1665         }
1666
1667         return EXT_MAX_BLOCKS;
1668 }
1669
1670 /*
1671  * ext4_ext_next_leaf_block:
1672  * returns first allocated block from next leaf or EXT_MAX_BLOCKS
1673  */
1674 static ext4_lblk_t ext4_ext_next_leaf_block(struct ext4_ext_path *path)
1675 {
1676         int depth;
1677
1678         BUG_ON(path == NULL);
1679         depth = path->p_depth;
1680
1681         /* zero-tree has no leaf blocks at all */
1682         if (depth == 0)
1683                 return EXT_MAX_BLOCKS;
1684
1685         /* go to index block */
1686         depth--;
1687
1688         while (depth >= 0) {
1689                 if (path[depth].p_idx !=
1690                                 EXT_LAST_INDEX(path[depth].p_hdr))
1691                         return (ext4_lblk_t)
1692                                 le32_to_cpu(path[depth].p_idx[1].ei_block);
1693                 depth--;
1694         }
1695
1696         return EXT_MAX_BLOCKS;
1697 }
1698
1699 /*
1700  * ext4_ext_correct_indexes:
1701  * if leaf gets modified and modified extent is first in the leaf,
1702  * then we have to correct all indexes above.
1703  * TODO: do we need to correct tree in all cases?
1704  */
1705 static int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode,
1706                                 struct ext4_ext_path *path)
1707 {
1708         struct ext4_extent_header *eh;
1709         int depth = ext_depth(inode);
1710         struct ext4_extent *ex;
1711         __le32 border;
1712         int k, err = 0;
1713
1714         eh = path[depth].p_hdr;
1715         ex = path[depth].p_ext;
1716
1717         if (unlikely(ex == NULL || eh == NULL)) {
1718                 EXT4_ERROR_INODE(inode,
1719                                  "ex %p == NULL or eh %p == NULL", ex, eh);
1720                 return -EFSCORRUPTED;
1721         }
1722
1723         if (depth == 0) {
1724                 /* there is no tree at all */
1725                 return 0;
1726         }
1727
1728         if (ex != EXT_FIRST_EXTENT(eh)) {
1729                 /* we correct tree if first leaf got modified only */
1730                 return 0;
1731         }
1732
1733         /*
1734          * TODO: we need correction if border is smaller than current one
1735          */
1736         k = depth - 1;
1737         border = path[depth].p_ext->ee_block;
1738         err = ext4_ext_get_access(handle, inode, path + k);
1739         if (err)
1740                 return err;
1741         path[k].p_idx->ei_block = border;
1742         err = ext4_ext_dirty(handle, inode, path + k);
1743         if (err)
1744                 return err;
1745
1746         while (k--) {
1747                 /* change all left-side indexes */
1748                 if (path[k+1].p_idx != EXT_FIRST_INDEX(path[k+1].p_hdr))
1749                         break;
1750                 err = ext4_ext_get_access(handle, inode, path + k);
1751                 if (err)
1752                         break;
1753                 path[k].p_idx->ei_block = border;
1754                 err = ext4_ext_dirty(handle, inode, path + k);
1755                 if (err)
1756                         break;
1757         }
1758
1759         return err;
1760 }
1761
1762 static int ext4_can_extents_be_merged(struct inode *inode,
1763                                       struct ext4_extent *ex1,
1764                                       struct ext4_extent *ex2)
1765 {
1766         unsigned short ext1_ee_len, ext2_ee_len;
1767
1768         if (ext4_ext_is_unwritten(ex1) != ext4_ext_is_unwritten(ex2))
1769                 return 0;
1770
1771         ext1_ee_len = ext4_ext_get_actual_len(ex1);
1772         ext2_ee_len = ext4_ext_get_actual_len(ex2);
1773
1774         if (le32_to_cpu(ex1->ee_block) + ext1_ee_len !=
1775                         le32_to_cpu(ex2->ee_block))
1776                 return 0;
1777
1778         if (ext1_ee_len + ext2_ee_len > EXT_INIT_MAX_LEN)
1779                 return 0;
1780
1781         if (ext4_ext_is_unwritten(ex1) &&
1782             ext1_ee_len + ext2_ee_len > EXT_UNWRITTEN_MAX_LEN)
1783                 return 0;
1784 #ifdef AGGRESSIVE_TEST
1785         if (ext1_ee_len >= 4)
1786                 return 0;
1787 #endif
1788
1789         if (ext4_ext_pblock(ex1) + ext1_ee_len == ext4_ext_pblock(ex2))
1790                 return 1;
1791         return 0;
1792 }
1793
1794 /*
1795  * This function tries to merge the "ex" extent to the next extent in the tree.
1796  * It always tries to merge towards right. If you want to merge towards
1797  * left, pass "ex - 1" as argument instead of "ex".
1798  * Returns 0 if the extents (ex and ex+1) were _not_ merged and returns
1799  * 1 if they got merged.
1800  */
1801 static int ext4_ext_try_to_merge_right(struct inode *inode,
1802                                  struct ext4_ext_path *path,
1803                                  struct ext4_extent *ex)
1804 {
1805         struct ext4_extent_header *eh;
1806         unsigned int depth, len;
1807         int merge_done = 0, unwritten;
1808
1809         depth = ext_depth(inode);
1810         BUG_ON(path[depth].p_hdr == NULL);
1811         eh = path[depth].p_hdr;
1812
1813         while (ex < EXT_LAST_EXTENT(eh)) {
1814                 if (!ext4_can_extents_be_merged(inode, ex, ex + 1))
1815                         break;
1816                 /* merge with next extent! */
1817                 unwritten = ext4_ext_is_unwritten(ex);
1818                 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
1819                                 + ext4_ext_get_actual_len(ex + 1));
1820                 if (unwritten)
1821                         ext4_ext_mark_unwritten(ex);
1822
1823                 if (ex + 1 < EXT_LAST_EXTENT(eh)) {
1824                         len = (EXT_LAST_EXTENT(eh) - ex - 1)
1825                                 * sizeof(struct ext4_extent);
1826                         memmove(ex + 1, ex + 2, len);
1827                 }
1828                 le16_add_cpu(&eh->eh_entries, -1);
1829                 merge_done = 1;
1830                 WARN_ON(eh->eh_entries == 0);
1831                 if (!eh->eh_entries)
1832                         EXT4_ERROR_INODE(inode, "eh->eh_entries = 0!");
1833         }
1834
1835         return merge_done;
1836 }
1837
1838 /*
1839  * This function does a very simple check to see if we can collapse
1840  * an extent tree with a single extent tree leaf block into the inode.
1841  */
1842 static void ext4_ext_try_to_merge_up(handle_t *handle,
1843                                      struct inode *inode,
1844                                      struct ext4_ext_path *path)
1845 {
1846         size_t s;
1847         unsigned max_root = ext4_ext_space_root(inode, 0);
1848         ext4_fsblk_t blk;
1849
1850         if ((path[0].p_depth != 1) ||
1851             (le16_to_cpu(path[0].p_hdr->eh_entries) != 1) ||
1852             (le16_to_cpu(path[1].p_hdr->eh_entries) > max_root))
1853                 return;
1854
1855         /*
1856          * We need to modify the block allocation bitmap and the block
1857          * group descriptor to release the extent tree block.  If we
1858          * can't get the journal credits, give up.
1859          */
1860         if (ext4_journal_extend(handle, 2,
1861                         ext4_free_metadata_revoke_credits(inode->i_sb, 1)))
1862                 return;
1863
1864         /*
1865          * Copy the extent data up to the inode
1866          */
1867         blk = ext4_idx_pblock(path[0].p_idx);
1868         s = le16_to_cpu(path[1].p_hdr->eh_entries) *
1869                 sizeof(struct ext4_extent_idx);
1870         s += sizeof(struct ext4_extent_header);
1871
1872         path[1].p_maxdepth = path[0].p_maxdepth;
1873         memcpy(path[0].p_hdr, path[1].p_hdr, s);
1874         path[0].p_depth = 0;
1875         path[0].p_ext = EXT_FIRST_EXTENT(path[0].p_hdr) +
1876                 (path[1].p_ext - EXT_FIRST_EXTENT(path[1].p_hdr));
1877         path[0].p_hdr->eh_max = cpu_to_le16(max_root);
1878
1879         brelse(path[1].p_bh);
1880         ext4_free_blocks(handle, inode, NULL, blk, 1,
1881                          EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
1882 }
1883
1884 /*
1885  * This function tries to merge the @ex extent to neighbours in the tree, then
1886  * tries to collapse the extent tree into the inode.
1887  */
1888 static void ext4_ext_try_to_merge(handle_t *handle,
1889                                   struct inode *inode,
1890                                   struct ext4_ext_path *path,
1891                                   struct ext4_extent *ex)
1892 {
1893         struct ext4_extent_header *eh;
1894         unsigned int depth;
1895         int merge_done = 0;
1896
1897         depth = ext_depth(inode);
1898         BUG_ON(path[depth].p_hdr == NULL);
1899         eh = path[depth].p_hdr;
1900
1901         if (ex > EXT_FIRST_EXTENT(eh))
1902                 merge_done = ext4_ext_try_to_merge_right(inode, path, ex - 1);
1903
1904         if (!merge_done)
1905                 (void) ext4_ext_try_to_merge_right(inode, path, ex);
1906
1907         ext4_ext_try_to_merge_up(handle, inode, path);
1908 }
1909
1910 /*
1911  * check if a portion of the "newext" extent overlaps with an
1912  * existing extent.
1913  *
1914  * If there is an overlap discovered, it updates the length of the newext
1915  * such that there will be no overlap, and then returns 1.
1916  * If there is no overlap found, it returns 0.
1917  */
1918 static unsigned int ext4_ext_check_overlap(struct ext4_sb_info *sbi,
1919                                            struct inode *inode,
1920                                            struct ext4_extent *newext,
1921                                            struct ext4_ext_path *path)
1922 {
1923         ext4_lblk_t b1, b2;
1924         unsigned int depth, len1;
1925         unsigned int ret = 0;
1926
1927         b1 = le32_to_cpu(newext->ee_block);
1928         len1 = ext4_ext_get_actual_len(newext);
1929         depth = ext_depth(inode);
1930         if (!path[depth].p_ext)
1931                 goto out;
1932         b2 = EXT4_LBLK_CMASK(sbi, le32_to_cpu(path[depth].p_ext->ee_block));
1933
1934         /*
1935          * get the next allocated block if the extent in the path
1936          * is before the requested block(s)
1937          */
1938         if (b2 < b1) {
1939                 b2 = ext4_ext_next_allocated_block(path);
1940                 if (b2 == EXT_MAX_BLOCKS)
1941                         goto out;
1942                 b2 = EXT4_LBLK_CMASK(sbi, b2);
1943         }
1944
1945         /* check for wrap through zero on extent logical start block*/
1946         if (b1 + len1 < b1) {
1947                 len1 = EXT_MAX_BLOCKS - b1;
1948                 newext->ee_len = cpu_to_le16(len1);
1949                 ret = 1;
1950         }
1951
1952         /* check for overlap */
1953         if (b1 + len1 > b2) {
1954                 newext->ee_len = cpu_to_le16(b2 - b1);
1955                 ret = 1;
1956         }
1957 out:
1958         return ret;
1959 }
1960
1961 /*
1962  * ext4_ext_insert_extent:
1963  * tries to merge requested extent into the existing extent or
1964  * inserts requested extent as new one into the tree,
1965  * creating new leaf in the no-space case.
1966  */
1967 int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
1968                                 struct ext4_ext_path **ppath,
1969                                 struct ext4_extent *newext, int gb_flags)
1970 {
1971         struct ext4_ext_path *path = *ppath;
1972         struct ext4_extent_header *eh;
1973         struct ext4_extent *ex, *fex;
1974         struct ext4_extent *nearex; /* nearest extent */
1975         struct ext4_ext_path *npath = NULL;
1976         int depth, len, err;
1977         ext4_lblk_t next;
1978         int mb_flags = 0, unwritten;
1979
1980         if (gb_flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
1981                 mb_flags |= EXT4_MB_DELALLOC_RESERVED;
1982         if (unlikely(ext4_ext_get_actual_len(newext) == 0)) {
1983                 EXT4_ERROR_INODE(inode, "ext4_ext_get_actual_len(newext) == 0");
1984                 return -EFSCORRUPTED;
1985         }
1986         depth = ext_depth(inode);
1987         ex = path[depth].p_ext;
1988         eh = path[depth].p_hdr;
1989         if (unlikely(path[depth].p_hdr == NULL)) {
1990                 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
1991                 return -EFSCORRUPTED;
1992         }
1993
1994         /* try to insert block into found extent and return */
1995         if (ex && !(gb_flags & EXT4_GET_BLOCKS_PRE_IO)) {
1996
1997                 /*
1998                  * Try to see whether we should rather test the extent on
1999                  * right from ex, or from the left of ex. This is because
2000                  * ext4_find_extent() can return either extent on the
2001                  * left, or on the right from the searched position. This
2002                  * will make merging more effective.
2003                  */
2004                 if (ex < EXT_LAST_EXTENT(eh) &&
2005                     (le32_to_cpu(ex->ee_block) +
2006                     ext4_ext_get_actual_len(ex) <
2007                     le32_to_cpu(newext->ee_block))) {
2008                         ex += 1;
2009                         goto prepend;
2010                 } else if ((ex > EXT_FIRST_EXTENT(eh)) &&
2011                            (le32_to_cpu(newext->ee_block) +
2012                            ext4_ext_get_actual_len(newext) <
2013                            le32_to_cpu(ex->ee_block)))
2014                         ex -= 1;
2015
2016                 /* Try to append newex to the ex */
2017                 if (ext4_can_extents_be_merged(inode, ex, newext)) {
2018                         ext_debug(inode, "append [%d]%d block to %u:[%d]%d"
2019                                   "(from %llu)\n",
2020                                   ext4_ext_is_unwritten(newext),
2021                                   ext4_ext_get_actual_len(newext),
2022                                   le32_to_cpu(ex->ee_block),
2023                                   ext4_ext_is_unwritten(ex),
2024                                   ext4_ext_get_actual_len(ex),
2025                                   ext4_ext_pblock(ex));
2026                         err = ext4_ext_get_access(handle, inode,
2027                                                   path + depth);
2028                         if (err)
2029                                 return err;
2030                         unwritten = ext4_ext_is_unwritten(ex);
2031                         ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
2032                                         + ext4_ext_get_actual_len(newext));
2033                         if (unwritten)
2034                                 ext4_ext_mark_unwritten(ex);
2035                         nearex = ex;
2036                         goto merge;
2037                 }
2038
2039 prepend:
2040                 /* Try to prepend newex to the ex */
2041                 if (ext4_can_extents_be_merged(inode, newext, ex)) {
2042                         ext_debug(inode, "prepend %u[%d]%d block to %u:[%d]%d"
2043                                   "(from %llu)\n",
2044                                   le32_to_cpu(newext->ee_block),
2045                                   ext4_ext_is_unwritten(newext),
2046                                   ext4_ext_get_actual_len(newext),
2047                                   le32_to_cpu(ex->ee_block),
2048                                   ext4_ext_is_unwritten(ex),
2049                                   ext4_ext_get_actual_len(ex),
2050                                   ext4_ext_pblock(ex));
2051                         err = ext4_ext_get_access(handle, inode,
2052                                                   path + depth);
2053                         if (err)
2054                                 return err;
2055
2056                         unwritten = ext4_ext_is_unwritten(ex);
2057                         ex->ee_block = newext->ee_block;
2058                         ext4_ext_store_pblock(ex, ext4_ext_pblock(newext));
2059                         ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
2060                                         + ext4_ext_get_actual_len(newext));
2061                         if (unwritten)
2062                                 ext4_ext_mark_unwritten(ex);
2063                         nearex = ex;
2064                         goto merge;
2065                 }
2066         }
2067
2068         depth = ext_depth(inode);
2069         eh = path[depth].p_hdr;
2070         if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max))
2071                 goto has_space;
2072
2073         /* probably next leaf has space for us? */
2074         fex = EXT_LAST_EXTENT(eh);
2075         next = EXT_MAX_BLOCKS;
2076         if (le32_to_cpu(newext->ee_block) > le32_to_cpu(fex->ee_block))
2077                 next = ext4_ext_next_leaf_block(path);
2078         if (next != EXT_MAX_BLOCKS) {
2079                 ext_debug(inode, "next leaf block - %u\n", next);
2080                 BUG_ON(npath != NULL);
2081                 npath = ext4_find_extent(inode, next, NULL, gb_flags);
2082                 if (IS_ERR(npath))
2083                         return PTR_ERR(npath);
2084                 BUG_ON(npath->p_depth != path->p_depth);
2085                 eh = npath[depth].p_hdr;
2086                 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) {
2087                         ext_debug(inode, "next leaf isn't full(%d)\n",
2088                                   le16_to_cpu(eh->eh_entries));
2089                         path = npath;
2090                         goto has_space;
2091                 }
2092                 ext_debug(inode, "next leaf has no free space(%d,%d)\n",
2093                           le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
2094         }
2095
2096         /*
2097          * There is no free space in the found leaf.
2098          * We're gonna add a new leaf in the tree.
2099          */
2100         if (gb_flags & EXT4_GET_BLOCKS_METADATA_NOFAIL)
2101                 mb_flags |= EXT4_MB_USE_RESERVED;
2102         err = ext4_ext_create_new_leaf(handle, inode, mb_flags, gb_flags,
2103                                        ppath, newext);
2104         if (err)
2105                 goto cleanup;
2106         depth = ext_depth(inode);
2107         eh = path[depth].p_hdr;
2108
2109 has_space:
2110         nearex = path[depth].p_ext;
2111
2112         err = ext4_ext_get_access(handle, inode, path + depth);
2113         if (err)
2114                 goto cleanup;
2115
2116         if (!nearex) {
2117                 /* there is no extent in this leaf, create first one */
2118                 ext_debug(inode, "first extent in the leaf: %u:%llu:[%d]%d\n",
2119                                 le32_to_cpu(newext->ee_block),
2120                                 ext4_ext_pblock(newext),
2121                                 ext4_ext_is_unwritten(newext),
2122                                 ext4_ext_get_actual_len(newext));
2123                 nearex = EXT_FIRST_EXTENT(eh);
2124         } else {
2125                 if (le32_to_cpu(newext->ee_block)
2126                            > le32_to_cpu(nearex->ee_block)) {
2127                         /* Insert after */
2128                         ext_debug(inode, "insert %u:%llu:[%d]%d before: "
2129                                         "nearest %p\n",
2130                                         le32_to_cpu(newext->ee_block),
2131                                         ext4_ext_pblock(newext),
2132                                         ext4_ext_is_unwritten(newext),
2133                                         ext4_ext_get_actual_len(newext),
2134                                         nearex);
2135                         nearex++;
2136                 } else {
2137                         /* Insert before */
2138                         BUG_ON(newext->ee_block == nearex->ee_block);
2139                         ext_debug(inode, "insert %u:%llu:[%d]%d after: "
2140                                         "nearest %p\n",
2141                                         le32_to_cpu(newext->ee_block),
2142                                         ext4_ext_pblock(newext),
2143                                         ext4_ext_is_unwritten(newext),
2144                                         ext4_ext_get_actual_len(newext),
2145                                         nearex);
2146                 }
2147                 len = EXT_LAST_EXTENT(eh) - nearex + 1;
2148                 if (len > 0) {
2149                         ext_debug(inode, "insert %u:%llu:[%d]%d: "
2150                                         "move %d extents from 0x%p to 0x%p\n",
2151                                         le32_to_cpu(newext->ee_block),
2152                                         ext4_ext_pblock(newext),
2153                                         ext4_ext_is_unwritten(newext),
2154                                         ext4_ext_get_actual_len(newext),
2155                                         len, nearex, nearex + 1);
2156                         memmove(nearex + 1, nearex,
2157                                 len * sizeof(struct ext4_extent));
2158                 }
2159         }
2160
2161         le16_add_cpu(&eh->eh_entries, 1);
2162         path[depth].p_ext = nearex;
2163         nearex->ee_block = newext->ee_block;
2164         ext4_ext_store_pblock(nearex, ext4_ext_pblock(newext));
2165         nearex->ee_len = newext->ee_len;
2166
2167 merge:
2168         /* try to merge extents */
2169         if (!(gb_flags & EXT4_GET_BLOCKS_PRE_IO))
2170                 ext4_ext_try_to_merge(handle, inode, path, nearex);
2171
2172
2173         /* time to correct all indexes above */
2174         err = ext4_ext_correct_indexes(handle, inode, path);
2175         if (err)
2176                 goto cleanup;
2177
2178         err = ext4_ext_dirty(handle, inode, path + path->p_depth);
2179
2180 cleanup:
2181         ext4_free_ext_path(npath);
2182         return err;
2183 }
2184
2185 static int ext4_fill_es_cache_info(struct inode *inode,
2186                                    ext4_lblk_t block, ext4_lblk_t num,
2187                                    struct fiemap_extent_info *fieinfo)
2188 {
2189         ext4_lblk_t next, end = block + num - 1;
2190         struct extent_status es;
2191         unsigned char blksize_bits = inode->i_sb->s_blocksize_bits;
2192         unsigned int flags;
2193         int err;
2194
2195         while (block <= end) {
2196                 next = 0;
2197                 flags = 0;
2198                 if (!ext4_es_lookup_extent(inode, block, &next, &es))
2199                         break;
2200                 if (ext4_es_is_unwritten(&es))
2201                         flags |= FIEMAP_EXTENT_UNWRITTEN;
2202                 if (ext4_es_is_delayed(&es))
2203                         flags |= (FIEMAP_EXTENT_DELALLOC |
2204                                   FIEMAP_EXTENT_UNKNOWN);
2205                 if (ext4_es_is_hole(&es))
2206                         flags |= EXT4_FIEMAP_EXTENT_HOLE;
2207                 if (next == 0)
2208                         flags |= FIEMAP_EXTENT_LAST;
2209                 if (flags & (FIEMAP_EXTENT_DELALLOC|
2210                              EXT4_FIEMAP_EXTENT_HOLE))
2211                         es.es_pblk = 0;
2212                 else
2213                         es.es_pblk = ext4_es_pblock(&es);
2214                 err = fiemap_fill_next_extent(fieinfo,
2215                                 (__u64)es.es_lblk << blksize_bits,
2216                                 (__u64)es.es_pblk << blksize_bits,
2217                                 (__u64)es.es_len << blksize_bits,
2218                                 flags);
2219                 if (next == 0)
2220                         break;
2221                 block = next;
2222                 if (err < 0)
2223                         return err;
2224                 if (err == 1)
2225                         return 0;
2226         }
2227         return 0;
2228 }
2229
2230
2231 /*
2232  * ext4_ext_find_hole - find hole around given block according to the given path
2233  * @inode:      inode we lookup in
2234  * @path:       path in extent tree to @lblk
2235  * @lblk:       pointer to logical block around which we want to determine hole
2236  *
2237  * Determine hole length (and start if easily possible) around given logical
2238  * block. We don't try too hard to find the beginning of the hole but @path
2239  * actually points to extent before @lblk, we provide it.
2240  *
2241  * The function returns the length of a hole starting at @lblk. We update @lblk
2242  * to the beginning of the hole if we managed to find it.
2243  */
2244 static ext4_lblk_t ext4_ext_find_hole(struct inode *inode,
2245                                       struct ext4_ext_path *path,
2246                                       ext4_lblk_t *lblk)
2247 {
2248         int depth = ext_depth(inode);
2249         struct ext4_extent *ex;
2250         ext4_lblk_t len;
2251
2252         ex = path[depth].p_ext;
2253         if (ex == NULL) {
2254                 /* there is no extent yet, so gap is [0;-] */
2255                 *lblk = 0;
2256                 len = EXT_MAX_BLOCKS;
2257         } else if (*lblk < le32_to_cpu(ex->ee_block)) {
2258                 len = le32_to_cpu(ex->ee_block) - *lblk;
2259         } else if (*lblk >= le32_to_cpu(ex->ee_block)
2260                         + ext4_ext_get_actual_len(ex)) {
2261                 ext4_lblk_t next;
2262
2263                 *lblk = le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex);
2264                 next = ext4_ext_next_allocated_block(path);
2265                 BUG_ON(next == *lblk);
2266                 len = next - *lblk;
2267         } else {
2268                 BUG();
2269         }
2270         return len;
2271 }
2272
2273 /*
2274  * ext4_ext_rm_idx:
2275  * removes index from the index block.
2276  */
2277 static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode,
2278                         struct ext4_ext_path *path, int depth)
2279 {
2280         int err;
2281         ext4_fsblk_t leaf;
2282
2283         /* free index block */
2284         depth--;
2285         path = path + depth;
2286         leaf = ext4_idx_pblock(path->p_idx);
2287         if (unlikely(path->p_hdr->eh_entries == 0)) {
2288                 EXT4_ERROR_INODE(inode, "path->p_hdr->eh_entries == 0");
2289                 return -EFSCORRUPTED;
2290         }
2291         err = ext4_ext_get_access(handle, inode, path);
2292         if (err)
2293                 return err;
2294
2295         if (path->p_idx != EXT_LAST_INDEX(path->p_hdr)) {
2296                 int len = EXT_LAST_INDEX(path->p_hdr) - path->p_idx;
2297                 len *= sizeof(struct ext4_extent_idx);
2298                 memmove(path->p_idx, path->p_idx + 1, len);
2299         }
2300
2301         le16_add_cpu(&path->p_hdr->eh_entries, -1);
2302         err = ext4_ext_dirty(handle, inode, path);
2303         if (err)
2304                 return err;
2305         ext_debug(inode, "index is empty, remove it, free block %llu\n", leaf);
2306         trace_ext4_ext_rm_idx(inode, leaf);
2307
2308         ext4_free_blocks(handle, inode, NULL, leaf, 1,
2309                          EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
2310
2311         while (--depth >= 0) {
2312                 if (path->p_idx != EXT_FIRST_INDEX(path->p_hdr))
2313                         break;
2314                 path--;
2315                 err = ext4_ext_get_access(handle, inode, path);
2316                 if (err)
2317                         break;
2318                 path->p_idx->ei_block = (path+1)->p_idx->ei_block;
2319                 err = ext4_ext_dirty(handle, inode, path);
2320                 if (err)
2321                         break;
2322         }
2323         return err;
2324 }
2325
2326 /*
2327  * ext4_ext_calc_credits_for_single_extent:
2328  * This routine returns max. credits that needed to insert an extent
2329  * to the extent tree.
2330  * When pass the actual path, the caller should calculate credits
2331  * under i_data_sem.
2332  */
2333 int ext4_ext_calc_credits_for_single_extent(struct inode *inode, int nrblocks,
2334                                                 struct ext4_ext_path *path)
2335 {
2336         if (path) {
2337                 int depth = ext_depth(inode);
2338                 int ret = 0;
2339
2340                 /* probably there is space in leaf? */
2341                 if (le16_to_cpu(path[depth].p_hdr->eh_entries)
2342                                 < le16_to_cpu(path[depth].p_hdr->eh_max)) {
2343
2344                         /*
2345                          *  There are some space in the leaf tree, no
2346                          *  need to account for leaf block credit
2347                          *
2348                          *  bitmaps and block group descriptor blocks
2349                          *  and other metadata blocks still need to be
2350                          *  accounted.
2351                          */
2352                         /* 1 bitmap, 1 block group descriptor */
2353                         ret = 2 + EXT4_META_TRANS_BLOCKS(inode->i_sb);
2354                         return ret;
2355                 }
2356         }
2357
2358         return ext4_chunk_trans_blocks(inode, nrblocks);
2359 }
2360
2361 /*
2362  * How many index/leaf blocks need to change/allocate to add @extents extents?
2363  *
2364  * If we add a single extent, then in the worse case, each tree level
2365  * index/leaf need to be changed in case of the tree split.
2366  *
2367  * If more extents are inserted, they could cause the whole tree split more
2368  * than once, but this is really rare.
2369  */
2370 int ext4_ext_index_trans_blocks(struct inode *inode, int extents)
2371 {
2372         int index;
2373         int depth;
2374
2375         /* If we are converting the inline data, only one is needed here. */
2376         if (ext4_has_inline_data(inode))
2377                 return 1;
2378
2379         depth = ext_depth(inode);
2380
2381         if (extents <= 1)
2382                 index = depth * 2;
2383         else
2384                 index = depth * 3;
2385
2386         return index;
2387 }
2388
2389 static inline int get_default_free_blocks_flags(struct inode *inode)
2390 {
2391         if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode) ||
2392             ext4_test_inode_flag(inode, EXT4_INODE_EA_INODE))
2393                 return EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET;
2394         else if (ext4_should_journal_data(inode))
2395                 return EXT4_FREE_BLOCKS_FORGET;
2396         return 0;
2397 }
2398
2399 /*
2400  * ext4_rereserve_cluster - increment the reserved cluster count when
2401  *                          freeing a cluster with a pending reservation
2402  *
2403  * @inode - file containing the cluster
2404  * @lblk - logical block in cluster to be reserved
2405  *
2406  * Increments the reserved cluster count and adjusts quota in a bigalloc
2407  * file system when freeing a partial cluster containing at least one
2408  * delayed and unwritten block.  A partial cluster meeting that
2409  * requirement will have a pending reservation.  If so, the
2410  * RERESERVE_CLUSTER flag is used when calling ext4_free_blocks() to
2411  * defer reserved and allocated space accounting to a subsequent call
2412  * to this function.
2413  */
2414 static void ext4_rereserve_cluster(struct inode *inode, ext4_lblk_t lblk)
2415 {
2416         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2417         struct ext4_inode_info *ei = EXT4_I(inode);
2418
2419         dquot_reclaim_block(inode, EXT4_C2B(sbi, 1));
2420
2421         spin_lock(&ei->i_block_reservation_lock);
2422         ei->i_reserved_data_blocks++;
2423         percpu_counter_add(&sbi->s_dirtyclusters_counter, 1);
2424         spin_unlock(&ei->i_block_reservation_lock);
2425
2426         percpu_counter_add(&sbi->s_freeclusters_counter, 1);
2427         ext4_remove_pending(inode, lblk);
2428 }
2429
2430 static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
2431                               struct ext4_extent *ex,
2432                               struct partial_cluster *partial,
2433                               ext4_lblk_t from, ext4_lblk_t to)
2434 {
2435         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2436         unsigned short ee_len = ext4_ext_get_actual_len(ex);
2437         ext4_fsblk_t last_pblk, pblk;
2438         ext4_lblk_t num;
2439         int flags;
2440
2441         /* only extent tail removal is allowed */
2442         if (from < le32_to_cpu(ex->ee_block) ||
2443             to != le32_to_cpu(ex->ee_block) + ee_len - 1) {
2444                 ext4_error(sbi->s_sb,
2445                            "strange request: removal(2) %u-%u from %u:%u",
2446                            from, to, le32_to_cpu(ex->ee_block), ee_len);
2447                 return 0;
2448         }
2449
2450 #ifdef EXTENTS_STATS
2451         spin_lock(&sbi->s_ext_stats_lock);
2452         sbi->s_ext_blocks += ee_len;
2453         sbi->s_ext_extents++;
2454         if (ee_len < sbi->s_ext_min)
2455                 sbi->s_ext_min = ee_len;
2456         if (ee_len > sbi->s_ext_max)
2457                 sbi->s_ext_max = ee_len;
2458         if (ext_depth(inode) > sbi->s_depth_max)
2459                 sbi->s_depth_max = ext_depth(inode);
2460         spin_unlock(&sbi->s_ext_stats_lock);
2461 #endif
2462
2463         trace_ext4_remove_blocks(inode, ex, from, to, partial);
2464
2465         /*
2466          * if we have a partial cluster, and it's different from the
2467          * cluster of the last block in the extent, we free it
2468          */
2469         last_pblk = ext4_ext_pblock(ex) + ee_len - 1;
2470
2471         if (partial->state != initial &&
2472             partial->pclu != EXT4_B2C(sbi, last_pblk)) {
2473                 if (partial->state == tofree) {
2474                         flags = get_default_free_blocks_flags(inode);
2475                         if (ext4_is_pending(inode, partial->lblk))
2476                                 flags |= EXT4_FREE_BLOCKS_RERESERVE_CLUSTER;
2477                         ext4_free_blocks(handle, inode, NULL,
2478                                          EXT4_C2B(sbi, partial->pclu),
2479                                          sbi->s_cluster_ratio, flags);
2480                         if (flags & EXT4_FREE_BLOCKS_RERESERVE_CLUSTER)
2481                                 ext4_rereserve_cluster(inode, partial->lblk);
2482                 }
2483                 partial->state = initial;
2484         }
2485
2486         num = le32_to_cpu(ex->ee_block) + ee_len - from;
2487         pblk = ext4_ext_pblock(ex) + ee_len - num;
2488
2489         /*
2490          * We free the partial cluster at the end of the extent (if any),
2491          * unless the cluster is used by another extent (partial_cluster
2492          * state is nofree).  If a partial cluster exists here, it must be
2493          * shared with the last block in the extent.
2494          */
2495         flags = get_default_free_blocks_flags(inode);
2496
2497         /* partial, left end cluster aligned, right end unaligned */
2498         if ((EXT4_LBLK_COFF(sbi, to) != sbi->s_cluster_ratio - 1) &&
2499             (EXT4_LBLK_CMASK(sbi, to) >= from) &&
2500             (partial->state != nofree)) {
2501                 if (ext4_is_pending(inode, to))
2502                         flags |= EXT4_FREE_BLOCKS_RERESERVE_CLUSTER;
2503                 ext4_free_blocks(handle, inode, NULL,
2504                                  EXT4_PBLK_CMASK(sbi, last_pblk),
2505                                  sbi->s_cluster_ratio, flags);
2506                 if (flags & EXT4_FREE_BLOCKS_RERESERVE_CLUSTER)
2507                         ext4_rereserve_cluster(inode, to);
2508                 partial->state = initial;
2509                 flags = get_default_free_blocks_flags(inode);
2510         }
2511
2512         flags |= EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER;
2513
2514         /*
2515          * For bigalloc file systems, we never free a partial cluster
2516          * at the beginning of the extent.  Instead, we check to see if we
2517          * need to free it on a subsequent call to ext4_remove_blocks,
2518          * or at the end of ext4_ext_rm_leaf or ext4_ext_remove_space.
2519          */
2520         flags |= EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER;
2521         ext4_free_blocks(handle, inode, NULL, pblk, num, flags);
2522
2523         /* reset the partial cluster if we've freed past it */
2524         if (partial->state != initial && partial->pclu != EXT4_B2C(sbi, pblk))
2525                 partial->state = initial;
2526
2527         /*
2528          * If we've freed the entire extent but the beginning is not left
2529          * cluster aligned and is not marked as ineligible for freeing we
2530          * record the partial cluster at the beginning of the extent.  It
2531          * wasn't freed by the preceding ext4_free_blocks() call, and we
2532          * need to look farther to the left to determine if it's to be freed
2533          * (not shared with another extent). Else, reset the partial
2534          * cluster - we're either  done freeing or the beginning of the
2535          * extent is left cluster aligned.
2536          */
2537         if (EXT4_LBLK_COFF(sbi, from) && num == ee_len) {
2538                 if (partial->state == initial) {
2539                         partial->pclu = EXT4_B2C(sbi, pblk);
2540                         partial->lblk = from;
2541                         partial->state = tofree;
2542                 }
2543         } else {
2544                 partial->state = initial;
2545         }
2546
2547         return 0;
2548 }
2549
2550 /*
2551  * ext4_ext_rm_leaf() Removes the extents associated with the
2552  * blocks appearing between "start" and "end".  Both "start"
2553  * and "end" must appear in the same extent or EIO is returned.
2554  *
2555  * @handle: The journal handle
2556  * @inode:  The files inode
2557  * @path:   The path to the leaf
2558  * @partial_cluster: The cluster which we'll have to free if all extents
2559  *                   has been released from it.  However, if this value is
2560  *                   negative, it's a cluster just to the right of the
2561  *                   punched region and it must not be freed.
2562  * @start:  The first block to remove
2563  * @end:   The last block to remove
2564  */
2565 static int
2566 ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
2567                  struct ext4_ext_path *path,
2568                  struct partial_cluster *partial,
2569                  ext4_lblk_t start, ext4_lblk_t end)
2570 {
2571         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2572         int err = 0, correct_index = 0;
2573         int depth = ext_depth(inode), credits, revoke_credits;
2574         struct ext4_extent_header *eh;
2575         ext4_lblk_t a, b;
2576         unsigned num;
2577         ext4_lblk_t ex_ee_block;
2578         unsigned short ex_ee_len;
2579         unsigned unwritten = 0;
2580         struct ext4_extent *ex;
2581         ext4_fsblk_t pblk;
2582
2583         /* the header must be checked already in ext4_ext_remove_space() */
2584         ext_debug(inode, "truncate since %u in leaf to %u\n", start, end);
2585         if (!path[depth].p_hdr)
2586                 path[depth].p_hdr = ext_block_hdr(path[depth].p_bh);
2587         eh = path[depth].p_hdr;
2588         if (unlikely(path[depth].p_hdr == NULL)) {
2589                 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
2590                 return -EFSCORRUPTED;
2591         }
2592         /* find where to start removing */
2593         ex = path[depth].p_ext;
2594         if (!ex)
2595                 ex = EXT_LAST_EXTENT(eh);
2596
2597         ex_ee_block = le32_to_cpu(ex->ee_block);
2598         ex_ee_len = ext4_ext_get_actual_len(ex);
2599
2600         trace_ext4_ext_rm_leaf(inode, start, ex, partial);
2601
2602         while (ex >= EXT_FIRST_EXTENT(eh) &&
2603                         ex_ee_block + ex_ee_len > start) {
2604
2605                 if (ext4_ext_is_unwritten(ex))
2606                         unwritten = 1;
2607                 else
2608                         unwritten = 0;
2609
2610                 ext_debug(inode, "remove ext %u:[%d]%d\n", ex_ee_block,
2611                           unwritten, ex_ee_len);
2612                 path[depth].p_ext = ex;
2613
2614                 a = max(ex_ee_block, start);
2615                 b = min(ex_ee_block + ex_ee_len - 1, end);
2616
2617                 ext_debug(inode, "  border %u:%u\n", a, b);
2618
2619                 /* If this extent is beyond the end of the hole, skip it */
2620                 if (end < ex_ee_block) {
2621                         /*
2622                          * We're going to skip this extent and move to another,
2623                          * so note that its first cluster is in use to avoid
2624                          * freeing it when removing blocks.  Eventually, the
2625                          * right edge of the truncated/punched region will
2626                          * be just to the left.
2627                          */
2628                         if (sbi->s_cluster_ratio > 1) {
2629                                 pblk = ext4_ext_pblock(ex);
2630                                 partial->pclu = EXT4_B2C(sbi, pblk);
2631                                 partial->state = nofree;
2632                         }
2633                         ex--;
2634                         ex_ee_block = le32_to_cpu(ex->ee_block);
2635                         ex_ee_len = ext4_ext_get_actual_len(ex);
2636                         continue;
2637                 } else if (b != ex_ee_block + ex_ee_len - 1) {
2638                         EXT4_ERROR_INODE(inode,
2639                                          "can not handle truncate %u:%u "
2640                                          "on extent %u:%u",
2641                                          start, end, ex_ee_block,
2642                                          ex_ee_block + ex_ee_len - 1);
2643                         err = -EFSCORRUPTED;
2644                         goto out;
2645                 } else if (a != ex_ee_block) {
2646                         /* remove tail of the extent */
2647                         num = a - ex_ee_block;
2648                 } else {
2649                         /* remove whole extent: excellent! */
2650                         num = 0;
2651                 }
2652                 /*
2653                  * 3 for leaf, sb, and inode plus 2 (bmap and group
2654                  * descriptor) for each block group; assume two block
2655                  * groups plus ex_ee_len/blocks_per_block_group for
2656                  * the worst case
2657                  */
2658                 credits = 7 + 2*(ex_ee_len/EXT4_BLOCKS_PER_GROUP(inode->i_sb));
2659                 if (ex == EXT_FIRST_EXTENT(eh)) {
2660                         correct_index = 1;
2661                         credits += (ext_depth(inode)) + 1;
2662                 }
2663                 credits += EXT4_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb);
2664                 /*
2665                  * We may end up freeing some index blocks and data from the
2666                  * punched range. Note that partial clusters are accounted for
2667                  * by ext4_free_data_revoke_credits().
2668                  */
2669                 revoke_credits =
2670                         ext4_free_metadata_revoke_credits(inode->i_sb,
2671                                                           ext_depth(inode)) +
2672                         ext4_free_data_revoke_credits(inode, b - a + 1);
2673
2674                 err = ext4_datasem_ensure_credits(handle, inode, credits,
2675                                                   credits, revoke_credits);
2676                 if (err) {
2677                         if (err > 0)
2678                                 err = -EAGAIN;
2679                         goto out;
2680                 }
2681
2682                 err = ext4_ext_get_access(handle, inode, path + depth);
2683                 if (err)
2684                         goto out;
2685
2686                 err = ext4_remove_blocks(handle, inode, ex, partial, a, b);
2687                 if (err)
2688                         goto out;
2689
2690                 if (num == 0)
2691                         /* this extent is removed; mark slot entirely unused */
2692                         ext4_ext_store_pblock(ex, 0);
2693
2694                 ex->ee_len = cpu_to_le16(num);
2695                 /*
2696                  * Do not mark unwritten if all the blocks in the
2697                  * extent have been removed.
2698                  */
2699                 if (unwritten && num)
2700                         ext4_ext_mark_unwritten(ex);
2701                 /*
2702                  * If the extent was completely released,
2703                  * we need to remove it from the leaf
2704                  */
2705                 if (num == 0) {
2706                         if (end != EXT_MAX_BLOCKS - 1) {
2707                                 /*
2708                                  * For hole punching, we need to scoot all the
2709                                  * extents up when an extent is removed so that
2710                                  * we dont have blank extents in the middle
2711                                  */
2712                                 memmove(ex, ex+1, (EXT_LAST_EXTENT(eh) - ex) *
2713                                         sizeof(struct ext4_extent));
2714
2715                                 /* Now get rid of the one at the end */
2716                                 memset(EXT_LAST_EXTENT(eh), 0,
2717                                         sizeof(struct ext4_extent));
2718                         }
2719                         le16_add_cpu(&eh->eh_entries, -1);
2720                 }
2721
2722                 err = ext4_ext_dirty(handle, inode, path + depth);
2723                 if (err)
2724                         goto out;
2725
2726                 ext_debug(inode, "new extent: %u:%u:%llu\n", ex_ee_block, num,
2727                                 ext4_ext_pblock(ex));
2728                 ex--;
2729                 ex_ee_block = le32_to_cpu(ex->ee_block);
2730                 ex_ee_len = ext4_ext_get_actual_len(ex);
2731         }
2732
2733         if (correct_index && eh->eh_entries)
2734                 err = ext4_ext_correct_indexes(handle, inode, path);
2735
2736         /*
2737          * If there's a partial cluster and at least one extent remains in
2738          * the leaf, free the partial cluster if it isn't shared with the
2739          * current extent.  If it is shared with the current extent
2740          * we reset the partial cluster because we've reached the start of the
2741          * truncated/punched region and we're done removing blocks.
2742          */
2743         if (partial->state == tofree && ex >= EXT_FIRST_EXTENT(eh)) {
2744                 pblk = ext4_ext_pblock(ex) + ex_ee_len - 1;
2745                 if (partial->pclu != EXT4_B2C(sbi, pblk)) {
2746                         int flags = get_default_free_blocks_flags(inode);
2747
2748                         if (ext4_is_pending(inode, partial->lblk))
2749                                 flags |= EXT4_FREE_BLOCKS_RERESERVE_CLUSTER;
2750                         ext4_free_blocks(handle, inode, NULL,
2751                                          EXT4_C2B(sbi, partial->pclu),
2752                                          sbi->s_cluster_ratio, flags);
2753                         if (flags & EXT4_FREE_BLOCKS_RERESERVE_CLUSTER)
2754                                 ext4_rereserve_cluster(inode, partial->lblk);
2755                 }
2756                 partial->state = initial;
2757         }
2758
2759         /* if this leaf is free, then we should
2760          * remove it from index block above */
2761         if (err == 0 && eh->eh_entries == 0 && path[depth].p_bh != NULL)
2762                 err = ext4_ext_rm_idx(handle, inode, path, depth);
2763
2764 out:
2765         return err;
2766 }
2767
2768 /*
2769  * ext4_ext_more_to_rm:
2770  * returns 1 if current index has to be freed (even partial)
2771  */
2772 static int
2773 ext4_ext_more_to_rm(struct ext4_ext_path *path)
2774 {
2775         BUG_ON(path->p_idx == NULL);
2776
2777         if (path->p_idx < EXT_FIRST_INDEX(path->p_hdr))
2778                 return 0;
2779
2780         /*
2781          * if truncate on deeper level happened, it wasn't partial,
2782          * so we have to consider current index for truncation
2783          */
2784         if (le16_to_cpu(path->p_hdr->eh_entries) == path->p_block)
2785                 return 0;
2786         return 1;
2787 }
2788
2789 int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start,
2790                           ext4_lblk_t end)
2791 {
2792         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2793         int depth = ext_depth(inode);
2794         struct ext4_ext_path *path = NULL;
2795         struct partial_cluster partial;
2796         handle_t *handle;
2797         int i = 0, err = 0;
2798
2799         partial.pclu = 0;
2800         partial.lblk = 0;
2801         partial.state = initial;
2802
2803         ext_debug(inode, "truncate since %u to %u\n", start, end);
2804
2805         /* probably first extent we're gonna free will be last in block */
2806         handle = ext4_journal_start_with_revoke(inode, EXT4_HT_TRUNCATE,
2807                         depth + 1,
2808                         ext4_free_metadata_revoke_credits(inode->i_sb, depth));
2809         if (IS_ERR(handle))
2810                 return PTR_ERR(handle);
2811
2812 again:
2813         trace_ext4_ext_remove_space(inode, start, end, depth);
2814
2815         /*
2816          * Check if we are removing extents inside the extent tree. If that
2817          * is the case, we are going to punch a hole inside the extent tree
2818          * so we have to check whether we need to split the extent covering
2819          * the last block to remove so we can easily remove the part of it
2820          * in ext4_ext_rm_leaf().
2821          */
2822         if (end < EXT_MAX_BLOCKS - 1) {
2823                 struct ext4_extent *ex;
2824                 ext4_lblk_t ee_block, ex_end, lblk;
2825                 ext4_fsblk_t pblk;
2826
2827                 /* find extent for or closest extent to this block */
2828                 path = ext4_find_extent(inode, end, NULL,
2829                                         EXT4_EX_NOCACHE | EXT4_EX_NOFAIL);
2830                 if (IS_ERR(path)) {
2831                         ext4_journal_stop(handle);
2832                         return PTR_ERR(path);
2833                 }
2834                 depth = ext_depth(inode);
2835                 /* Leaf not may not exist only if inode has no blocks at all */
2836                 ex = path[depth].p_ext;
2837                 if (!ex) {
2838                         if (depth) {
2839                                 EXT4_ERROR_INODE(inode,
2840                                                  "path[%d].p_hdr == NULL",
2841                                                  depth);
2842                                 err = -EFSCORRUPTED;
2843                         }
2844                         goto out;
2845                 }
2846
2847                 ee_block = le32_to_cpu(ex->ee_block);
2848                 ex_end = ee_block + ext4_ext_get_actual_len(ex) - 1;
2849
2850                 /*
2851                  * See if the last block is inside the extent, if so split
2852                  * the extent at 'end' block so we can easily remove the
2853                  * tail of the first part of the split extent in
2854                  * ext4_ext_rm_leaf().
2855                  */
2856                 if (end >= ee_block && end < ex_end) {
2857
2858                         /*
2859                          * If we're going to split the extent, note that
2860                          * the cluster containing the block after 'end' is
2861                          * in use to avoid freeing it when removing blocks.
2862                          */
2863                         if (sbi->s_cluster_ratio > 1) {
2864                                 pblk = ext4_ext_pblock(ex) + end - ee_block + 1;
2865                                 partial.pclu = EXT4_B2C(sbi, pblk);
2866                                 partial.state = nofree;
2867                         }
2868
2869                         /*
2870                          * Split the extent in two so that 'end' is the last
2871                          * block in the first new extent. Also we should not
2872                          * fail removing space due to ENOSPC so try to use
2873                          * reserved block if that happens.
2874                          */
2875                         err = ext4_force_split_extent_at(handle, inode, &path,
2876                                                          end + 1, 1);
2877                         if (err < 0)
2878                                 goto out;
2879
2880                 } else if (sbi->s_cluster_ratio > 1 && end >= ex_end &&
2881                            partial.state == initial) {
2882                         /*
2883                          * If we're punching, there's an extent to the right.
2884                          * If the partial cluster hasn't been set, set it to
2885                          * that extent's first cluster and its state to nofree
2886                          * so it won't be freed should it contain blocks to be
2887                          * removed. If it's already set (tofree/nofree), we're
2888                          * retrying and keep the original partial cluster info
2889                          * so a cluster marked tofree as a result of earlier
2890                          * extent removal is not lost.
2891                          */
2892                         lblk = ex_end + 1;
2893                         err = ext4_ext_search_right(inode, path, &lblk, &pblk,
2894                                                     NULL);
2895                         if (err < 0)
2896                                 goto out;
2897                         if (pblk) {
2898                                 partial.pclu = EXT4_B2C(sbi, pblk);
2899                                 partial.state = nofree;
2900                         }
2901                 }
2902         }
2903         /*
2904          * We start scanning from right side, freeing all the blocks
2905          * after i_size and walking into the tree depth-wise.
2906          */
2907         depth = ext_depth(inode);
2908         if (path) {
2909                 int k = i = depth;
2910                 while (--k > 0)
2911                         path[k].p_block =
2912                                 le16_to_cpu(path[k].p_hdr->eh_entries)+1;
2913         } else {
2914                 path = kcalloc(depth + 1, sizeof(struct ext4_ext_path),
2915                                GFP_NOFS | __GFP_NOFAIL);
2916                 if (path == NULL) {
2917                         ext4_journal_stop(handle);
2918                         return -ENOMEM;
2919                 }
2920                 path[0].p_maxdepth = path[0].p_depth = depth;
2921                 path[0].p_hdr = ext_inode_hdr(inode);
2922                 i = 0;
2923
2924                 if (ext4_ext_check(inode, path[0].p_hdr, depth, 0)) {
2925                         err = -EFSCORRUPTED;
2926                         goto out;
2927                 }
2928         }
2929         err = 0;
2930
2931         while (i >= 0 && err == 0) {
2932                 if (i == depth) {
2933                         /* this is leaf block */
2934                         err = ext4_ext_rm_leaf(handle, inode, path,
2935                                                &partial, start, end);
2936                         /* root level has p_bh == NULL, brelse() eats this */
2937                         brelse(path[i].p_bh);
2938                         path[i].p_bh = NULL;
2939                         i--;
2940                         continue;
2941                 }
2942
2943                 /* this is index block */
2944                 if (!path[i].p_hdr) {
2945                         ext_debug(inode, "initialize header\n");
2946                         path[i].p_hdr = ext_block_hdr(path[i].p_bh);
2947                 }
2948
2949                 if (!path[i].p_idx) {
2950                         /* this level hasn't been touched yet */
2951                         path[i].p_idx = EXT_LAST_INDEX(path[i].p_hdr);
2952                         path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries)+1;
2953                         ext_debug(inode, "init index ptr: hdr 0x%p, num %d\n",
2954                                   path[i].p_hdr,
2955                                   le16_to_cpu(path[i].p_hdr->eh_entries));
2956                 } else {
2957                         /* we were already here, see at next index */
2958                         path[i].p_idx--;
2959                 }
2960
2961                 ext_debug(inode, "level %d - index, first 0x%p, cur 0x%p\n",
2962                                 i, EXT_FIRST_INDEX(path[i].p_hdr),
2963                                 path[i].p_idx);
2964                 if (ext4_ext_more_to_rm(path + i)) {
2965                         struct buffer_head *bh;
2966                         /* go to the next level */
2967                         ext_debug(inode, "move to level %d (block %llu)\n",
2968                                   i + 1, ext4_idx_pblock(path[i].p_idx));
2969                         memset(path + i + 1, 0, sizeof(*path));
2970                         bh = read_extent_tree_block(inode, path[i].p_idx,
2971                                                     depth - i - 1,
2972                                                     EXT4_EX_NOCACHE);
2973                         if (IS_ERR(bh)) {
2974                                 /* should we reset i_size? */
2975                                 err = PTR_ERR(bh);
2976                                 break;
2977                         }
2978                         /* Yield here to deal with large extent trees.
2979                          * Should be a no-op if we did IO above. */
2980                         cond_resched();
2981                         if (WARN_ON(i + 1 > depth)) {
2982                                 err = -EFSCORRUPTED;
2983                                 break;
2984                         }
2985                         path[i + 1].p_bh = bh;
2986
2987                         /* save actual number of indexes since this
2988                          * number is changed at the next iteration */
2989                         path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries);
2990                         i++;
2991                 } else {
2992                         /* we finished processing this index, go up */
2993                         if (path[i].p_hdr->eh_entries == 0 && i > 0) {
2994                                 /* index is empty, remove it;
2995                                  * handle must be already prepared by the
2996                                  * truncatei_leaf() */
2997                                 err = ext4_ext_rm_idx(handle, inode, path, i);
2998                         }
2999                         /* root level has p_bh == NULL, brelse() eats this */
3000                         brelse(path[i].p_bh);
3001                         path[i].p_bh = NULL;
3002                         i--;
3003                         ext_debug(inode, "return to level %d\n", i);
3004                 }
3005         }
3006
3007         trace_ext4_ext_remove_space_done(inode, start, end, depth, &partial,
3008                                          path->p_hdr->eh_entries);
3009
3010         /*
3011          * if there's a partial cluster and we have removed the first extent
3012          * in the file, then we also free the partial cluster, if any
3013          */
3014         if (partial.state == tofree && err == 0) {
3015                 int flags = get_default_free_blocks_flags(inode);
3016
3017                 if (ext4_is_pending(inode, partial.lblk))
3018                         flags |= EXT4_FREE_BLOCKS_RERESERVE_CLUSTER;
3019                 ext4_free_blocks(handle, inode, NULL,
3020                                  EXT4_C2B(sbi, partial.pclu),
3021                                  sbi->s_cluster_ratio, flags);
3022                 if (flags & EXT4_FREE_BLOCKS_RERESERVE_CLUSTER)
3023                         ext4_rereserve_cluster(inode, partial.lblk);
3024                 partial.state = initial;
3025         }
3026
3027         /* TODO: flexible tree reduction should be here */
3028         if (path->p_hdr->eh_entries == 0) {
3029                 /*
3030                  * truncate to zero freed all the tree,
3031                  * so we need to correct eh_depth
3032                  */
3033                 err = ext4_ext_get_access(handle, inode, path);
3034                 if (err == 0) {
3035                         ext_inode_hdr(inode)->eh_depth = 0;
3036                         ext_inode_hdr(inode)->eh_max =
3037                                 cpu_to_le16(ext4_ext_space_root(inode, 0));
3038                         err = ext4_ext_dirty(handle, inode, path);
3039                 }
3040         }
3041 out:
3042         ext4_free_ext_path(path);
3043         path = NULL;
3044         if (err == -EAGAIN)
3045                 goto again;
3046         ext4_journal_stop(handle);
3047
3048         return err;
3049 }
3050
3051 /*
3052  * called at mount time
3053  */
3054 void ext4_ext_init(struct super_block *sb)
3055 {
3056         /*
3057          * possible initialization would be here
3058          */
3059
3060         if (ext4_has_feature_extents(sb)) {
3061 #if defined(AGGRESSIVE_TEST) || defined(CHECK_BINSEARCH) || defined(EXTENTS_STATS)
3062                 printk(KERN_INFO "EXT4-fs: file extents enabled"
3063 #ifdef AGGRESSIVE_TEST
3064                        ", aggressive tests"
3065 #endif
3066 #ifdef CHECK_BINSEARCH
3067                        ", check binsearch"
3068 #endif
3069 #ifdef EXTENTS_STATS
3070                        ", stats"
3071 #endif
3072                        "\n");
3073 #endif
3074 #ifdef EXTENTS_STATS
3075                 spin_lock_init(&EXT4_SB(sb)->s_ext_stats_lock);
3076                 EXT4_SB(sb)->s_ext_min = 1 << 30;
3077                 EXT4_SB(sb)->s_ext_max = 0;
3078 #endif
3079         }
3080 }
3081
3082 /*
3083  * called at umount time
3084  */
3085 void ext4_ext_release(struct super_block *sb)
3086 {
3087         if (!ext4_has_feature_extents(sb))
3088                 return;
3089
3090 #ifdef EXTENTS_STATS
3091         if (EXT4_SB(sb)->s_ext_blocks && EXT4_SB(sb)->s_ext_extents) {
3092                 struct ext4_sb_info *sbi = EXT4_SB(sb);
3093                 printk(KERN_ERR "EXT4-fs: %lu blocks in %lu extents (%lu ave)\n",
3094                         sbi->s_ext_blocks, sbi->s_ext_extents,
3095                         sbi->s_ext_blocks / sbi->s_ext_extents);
3096                 printk(KERN_ERR "EXT4-fs: extents: %lu min, %lu max, max depth %lu\n",
3097                         sbi->s_ext_min, sbi->s_ext_max, sbi->s_depth_max);
3098         }
3099 #endif
3100 }
3101
3102 static void ext4_zeroout_es(struct inode *inode, struct ext4_extent *ex)
3103 {
3104         ext4_lblk_t  ee_block;
3105         ext4_fsblk_t ee_pblock;
3106         unsigned int ee_len;
3107
3108         ee_block  = le32_to_cpu(ex->ee_block);
3109         ee_len    = ext4_ext_get_actual_len(ex);
3110         ee_pblock = ext4_ext_pblock(ex);
3111
3112         if (ee_len == 0)
3113                 return;
3114
3115         ext4_es_insert_extent(inode, ee_block, ee_len, ee_pblock,
3116                               EXTENT_STATUS_WRITTEN);
3117 }
3118
3119 /* FIXME!! we need to try to merge to left or right after zero-out  */
3120 static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex)
3121 {
3122         ext4_fsblk_t ee_pblock;
3123         unsigned int ee_len;
3124
3125         ee_len    = ext4_ext_get_actual_len(ex);
3126         ee_pblock = ext4_ext_pblock(ex);
3127         return ext4_issue_zeroout(inode, le32_to_cpu(ex->ee_block), ee_pblock,
3128                                   ee_len);
3129 }
3130
3131 /*
3132  * ext4_split_extent_at() splits an extent at given block.
3133  *
3134  * @handle: the journal handle
3135  * @inode: the file inode
3136  * @path: the path to the extent
3137  * @split: the logical block where the extent is splitted.
3138  * @split_flags: indicates if the extent could be zeroout if split fails, and
3139  *               the states(init or unwritten) of new extents.
3140  * @flags: flags used to insert new extent to extent tree.
3141  *
3142  *
3143  * Splits extent [a, b] into two extents [a, @split) and [@split, b], states
3144  * of which are determined by split_flag.
3145  *
3146  * There are two cases:
3147  *  a> the extent are splitted into two extent.
3148  *  b> split is not needed, and just mark the extent.
3149  *
3150  * return 0 on success.
3151  */
3152 static int ext4_split_extent_at(handle_t *handle,
3153                              struct inode *inode,
3154                              struct ext4_ext_path **ppath,
3155                              ext4_lblk_t split,
3156                              int split_flag,
3157                              int flags)
3158 {
3159         struct ext4_ext_path *path = *ppath;
3160         ext4_fsblk_t newblock;
3161         ext4_lblk_t ee_block;
3162         struct ext4_extent *ex, newex, orig_ex, zero_ex;
3163         struct ext4_extent *ex2 = NULL;
3164         unsigned int ee_len, depth;
3165         int err = 0;
3166
3167         BUG_ON((split_flag & (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2)) ==
3168                (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2));
3169
3170         ext_debug(inode, "logical block %llu\n", (unsigned long long)split);
3171
3172         ext4_ext_show_leaf(inode, path);
3173
3174         depth = ext_depth(inode);
3175         ex = path[depth].p_ext;
3176         ee_block = le32_to_cpu(ex->ee_block);
3177         ee_len = ext4_ext_get_actual_len(ex);
3178         newblock = split - ee_block + ext4_ext_pblock(ex);
3179
3180         BUG_ON(split < ee_block || split >= (ee_block + ee_len));
3181         BUG_ON(!ext4_ext_is_unwritten(ex) &&
3182                split_flag & (EXT4_EXT_MAY_ZEROOUT |
3183                              EXT4_EXT_MARK_UNWRIT1 |
3184                              EXT4_EXT_MARK_UNWRIT2));
3185
3186         err = ext4_ext_get_access(handle, inode, path + depth);
3187         if (err)
3188                 goto out;
3189
3190         if (split == ee_block) {
3191                 /*
3192                  * case b: block @split is the block that the extent begins with
3193                  * then we just change the state of the extent, and splitting
3194                  * is not needed.
3195                  */
3196                 if (split_flag & EXT4_EXT_MARK_UNWRIT2)
3197                         ext4_ext_mark_unwritten(ex);
3198                 else
3199                         ext4_ext_mark_initialized(ex);
3200
3201                 if (!(flags & EXT4_GET_BLOCKS_PRE_IO))
3202                         ext4_ext_try_to_merge(handle, inode, path, ex);
3203
3204                 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3205                 goto out;
3206         }
3207
3208         /* case a */
3209         memcpy(&orig_ex, ex, sizeof(orig_ex));
3210         ex->ee_len = cpu_to_le16(split - ee_block);
3211         if (split_flag & EXT4_EXT_MARK_UNWRIT1)
3212                 ext4_ext_mark_unwritten(ex);
3213
3214         /*
3215          * path may lead to new leaf, not to original leaf any more
3216          * after ext4_ext_insert_extent() returns,
3217          */
3218         err = ext4_ext_dirty(handle, inode, path + depth);
3219         if (err)
3220                 goto fix_extent_len;
3221
3222         ex2 = &newex;
3223         ex2->ee_block = cpu_to_le32(split);
3224         ex2->ee_len   = cpu_to_le16(ee_len - (split - ee_block));
3225         ext4_ext_store_pblock(ex2, newblock);
3226         if (split_flag & EXT4_EXT_MARK_UNWRIT2)
3227                 ext4_ext_mark_unwritten(ex2);
3228
3229         err = ext4_ext_insert_extent(handle, inode, ppath, &newex, flags);
3230         if (err != -ENOSPC && err != -EDQUOT && err != -ENOMEM)
3231                 goto out;
3232
3233         if (EXT4_EXT_MAY_ZEROOUT & split_flag) {
3234                 if (split_flag & (EXT4_EXT_DATA_VALID1|EXT4_EXT_DATA_VALID2)) {
3235                         if (split_flag & EXT4_EXT_DATA_VALID1) {
3236                                 err = ext4_ext_zeroout(inode, ex2);
3237                                 zero_ex.ee_block = ex2->ee_block;
3238                                 zero_ex.ee_len = cpu_to_le16(
3239                                                 ext4_ext_get_actual_len(ex2));
3240                                 ext4_ext_store_pblock(&zero_ex,
3241                                                       ext4_ext_pblock(ex2));
3242                         } else {
3243                                 err = ext4_ext_zeroout(inode, ex);
3244                                 zero_ex.ee_block = ex->ee_block;
3245                                 zero_ex.ee_len = cpu_to_le16(
3246                                                 ext4_ext_get_actual_len(ex));
3247                                 ext4_ext_store_pblock(&zero_ex,
3248                                                       ext4_ext_pblock(ex));
3249                         }
3250                 } else {
3251                         err = ext4_ext_zeroout(inode, &orig_ex);
3252                         zero_ex.ee_block = orig_ex.ee_block;
3253                         zero_ex.ee_len = cpu_to_le16(
3254                                                 ext4_ext_get_actual_len(&orig_ex));
3255                         ext4_ext_store_pblock(&zero_ex,
3256                                               ext4_ext_pblock(&orig_ex));
3257                 }
3258
3259                 if (!err) {
3260                         /* update the extent length and mark as initialized */
3261                         ex->ee_len = cpu_to_le16(ee_len);
3262                         ext4_ext_try_to_merge(handle, inode, path, ex);
3263                         err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3264                         if (!err)
3265                                 /* update extent status tree */
3266                                 ext4_zeroout_es(inode, &zero_ex);
3267                         /* If we failed at this point, we don't know in which
3268                          * state the extent tree exactly is so don't try to fix
3269                          * length of the original extent as it may do even more
3270                          * damage.
3271                          */
3272                         goto out;
3273                 }
3274         }
3275
3276 fix_extent_len:
3277         ex->ee_len = orig_ex.ee_len;
3278         /*
3279          * Ignore ext4_ext_dirty return value since we are already in error path
3280          * and err is a non-zero error code.
3281          */
3282         ext4_ext_dirty(handle, inode, path + path->p_depth);
3283         return err;
3284 out:
3285         ext4_ext_show_leaf(inode, path);
3286         return err;
3287 }
3288
3289 /*
3290  * ext4_split_extents() splits an extent and mark extent which is covered
3291  * by @map as split_flags indicates
3292  *
3293  * It may result in splitting the extent into multiple extents (up to three)
3294  * There are three possibilities:
3295  *   a> There is no split required
3296  *   b> Splits in two extents: Split is happening at either end of the extent
3297  *   c> Splits in three extents: Somone is splitting in middle of the extent
3298  *
3299  */
3300 static int ext4_split_extent(handle_t *handle,
3301                               struct inode *inode,
3302                               struct ext4_ext_path **ppath,
3303                               struct ext4_map_blocks *map,
3304                               int split_flag,
3305                               int flags)
3306 {
3307         struct ext4_ext_path *path = *ppath;
3308         ext4_lblk_t ee_block;
3309         struct ext4_extent *ex;
3310         unsigned int ee_len, depth;
3311         int err = 0;
3312         int unwritten;
3313         int split_flag1, flags1;
3314         int allocated = map->m_len;
3315
3316         depth = ext_depth(inode);
3317         ex = path[depth].p_ext;
3318         ee_block = le32_to_cpu(ex->ee_block);
3319         ee_len = ext4_ext_get_actual_len(ex);
3320         unwritten = ext4_ext_is_unwritten(ex);
3321
3322         if (map->m_lblk + map->m_len < ee_block + ee_len) {
3323                 split_flag1 = split_flag & EXT4_EXT_MAY_ZEROOUT;
3324                 flags1 = flags | EXT4_GET_BLOCKS_PRE_IO;
3325                 if (unwritten)
3326                         split_flag1 |= EXT4_EXT_MARK_UNWRIT1 |
3327                                        EXT4_EXT_MARK_UNWRIT2;
3328                 if (split_flag & EXT4_EXT_DATA_VALID2)
3329                         split_flag1 |= EXT4_EXT_DATA_VALID1;
3330                 err = ext4_split_extent_at(handle, inode, ppath,
3331                                 map->m_lblk + map->m_len, split_flag1, flags1);
3332                 if (err)
3333                         goto out;
3334         } else {
3335                 allocated = ee_len - (map->m_lblk - ee_block);
3336         }
3337         /*
3338          * Update path is required because previous ext4_split_extent_at() may
3339          * result in split of original leaf or extent zeroout.
3340          */
3341         path = ext4_find_extent(inode, map->m_lblk, ppath, flags);
3342         if (IS_ERR(path))
3343                 return PTR_ERR(path);
3344         depth = ext_depth(inode);
3345         ex = path[depth].p_ext;
3346         if (!ex) {
3347                 EXT4_ERROR_INODE(inode, "unexpected hole at %lu",
3348                                  (unsigned long) map->m_lblk);
3349                 return -EFSCORRUPTED;
3350         }
3351         unwritten = ext4_ext_is_unwritten(ex);
3352
3353         if (map->m_lblk >= ee_block) {
3354                 split_flag1 = split_flag & EXT4_EXT_DATA_VALID2;
3355                 if (unwritten) {
3356                         split_flag1 |= EXT4_EXT_MARK_UNWRIT1;
3357                         split_flag1 |= split_flag & (EXT4_EXT_MAY_ZEROOUT |
3358                                                      EXT4_EXT_MARK_UNWRIT2);
3359                 }
3360                 err = ext4_split_extent_at(handle, inode, ppath,
3361                                 map->m_lblk, split_flag1, flags);
3362                 if (err)
3363                         goto out;
3364         }
3365
3366         ext4_ext_show_leaf(inode, path);
3367 out:
3368         return err ? err : allocated;
3369 }
3370
3371 /*
3372  * This function is called by ext4_ext_map_blocks() if someone tries to write
3373  * to an unwritten extent. It may result in splitting the unwritten
3374  * extent into multiple extents (up to three - one initialized and two
3375  * unwritten).
3376  * There are three possibilities:
3377  *   a> There is no split required: Entire extent should be initialized
3378  *   b> Splits in two extents: Write is happening at either end of the extent
3379  *   c> Splits in three extents: Somone is writing in middle of the extent
3380  *
3381  * Pre-conditions:
3382  *  - The extent pointed to by 'path' is unwritten.
3383  *  - The extent pointed to by 'path' contains a superset
3384  *    of the logical span [map->m_lblk, map->m_lblk + map->m_len).
3385  *
3386  * Post-conditions on success:
3387  *  - the returned value is the number of blocks beyond map->l_lblk
3388  *    that are allocated and initialized.
3389  *    It is guaranteed to be >= map->m_len.
3390  */
3391 static int ext4_ext_convert_to_initialized(handle_t *handle,
3392                                            struct inode *inode,
3393                                            struct ext4_map_blocks *map,
3394                                            struct ext4_ext_path **ppath,
3395                                            int flags)
3396 {
3397         struct ext4_ext_path *path = *ppath;
3398         struct ext4_sb_info *sbi;
3399         struct ext4_extent_header *eh;
3400         struct ext4_map_blocks split_map;
3401         struct ext4_extent zero_ex1, zero_ex2;
3402         struct ext4_extent *ex, *abut_ex;
3403         ext4_lblk_t ee_block, eof_block;
3404         unsigned int ee_len, depth, map_len = map->m_len;
3405         int allocated = 0, max_zeroout = 0;
3406         int err = 0;
3407         int split_flag = EXT4_EXT_DATA_VALID2;
3408
3409         ext_debug(inode, "logical block %llu, max_blocks %u\n",
3410                   (unsigned long long)map->m_lblk, map_len);
3411
3412         sbi = EXT4_SB(inode->i_sb);
3413         eof_block = (EXT4_I(inode)->i_disksize + inode->i_sb->s_blocksize - 1)
3414                         >> inode->i_sb->s_blocksize_bits;
3415         if (eof_block < map->m_lblk + map_len)
3416                 eof_block = map->m_lblk + map_len;
3417
3418         depth = ext_depth(inode);
3419         eh = path[depth].p_hdr;
3420         ex = path[depth].p_ext;
3421         ee_block = le32_to_cpu(ex->ee_block);
3422         ee_len = ext4_ext_get_actual_len(ex);
3423         zero_ex1.ee_len = 0;
3424         zero_ex2.ee_len = 0;
3425
3426         trace_ext4_ext_convert_to_initialized_enter(inode, map, ex);
3427
3428         /* Pre-conditions */
3429         BUG_ON(!ext4_ext_is_unwritten(ex));
3430         BUG_ON(!in_range(map->m_lblk, ee_block, ee_len));
3431
3432         /*
3433          * Attempt to transfer newly initialized blocks from the currently
3434          * unwritten extent to its neighbor. This is much cheaper
3435          * than an insertion followed by a merge as those involve costly
3436          * memmove() calls. Transferring to the left is the common case in
3437          * steady state for workloads doing fallocate(FALLOC_FL_KEEP_SIZE)
3438          * followed by append writes.
3439          *
3440          * Limitations of the current logic:
3441          *  - L1: we do not deal with writes covering the whole extent.
3442          *    This would require removing the extent if the transfer
3443          *    is possible.
3444          *  - L2: we only attempt to merge with an extent stored in the
3445          *    same extent tree node.
3446          */
3447         if ((map->m_lblk == ee_block) &&
3448                 /* See if we can merge left */
3449                 (map_len < ee_len) &&           /*L1*/
3450                 (ex > EXT_FIRST_EXTENT(eh))) {  /*L2*/
3451                 ext4_lblk_t prev_lblk;
3452                 ext4_fsblk_t prev_pblk, ee_pblk;
3453                 unsigned int prev_len;
3454
3455                 abut_ex = ex - 1;
3456                 prev_lblk = le32_to_cpu(abut_ex->ee_block);
3457                 prev_len = ext4_ext_get_actual_len(abut_ex);
3458                 prev_pblk = ext4_ext_pblock(abut_ex);
3459                 ee_pblk = ext4_ext_pblock(ex);
3460
3461                 /*
3462                  * A transfer of blocks from 'ex' to 'abut_ex' is allowed
3463                  * upon those conditions:
3464                  * - C1: abut_ex is initialized,
3465                  * - C2: abut_ex is logically abutting ex,
3466                  * - C3: abut_ex is physically abutting ex,
3467                  * - C4: abut_ex can receive the additional blocks without
3468                  *   overflowing the (initialized) length limit.
3469                  */
3470                 if ((!ext4_ext_is_unwritten(abut_ex)) &&                /*C1*/
3471                         ((prev_lblk + prev_len) == ee_block) &&         /*C2*/
3472                         ((prev_pblk + prev_len) == ee_pblk) &&          /*C3*/
3473                         (prev_len < (EXT_INIT_MAX_LEN - map_len))) {    /*C4*/
3474                         err = ext4_ext_get_access(handle, inode, path + depth);
3475                         if (err)
3476                                 goto out;
3477
3478                         trace_ext4_ext_convert_to_initialized_fastpath(inode,
3479                                 map, ex, abut_ex);
3480
3481                         /* Shift the start of ex by 'map_len' blocks */
3482                         ex->ee_block = cpu_to_le32(ee_block + map_len);
3483                         ext4_ext_store_pblock(ex, ee_pblk + map_len);
3484                         ex->ee_len = cpu_to_le16(ee_len - map_len);
3485                         ext4_ext_mark_unwritten(ex); /* Restore the flag */
3486
3487                         /* Extend abut_ex by 'map_len' blocks */
3488                         abut_ex->ee_len = cpu_to_le16(prev_len + map_len);
3489
3490                         /* Result: number of initialized blocks past m_lblk */
3491                         allocated = map_len;
3492                 }
3493         } else if (((map->m_lblk + map_len) == (ee_block + ee_len)) &&
3494                    (map_len < ee_len) &&        /*L1*/
3495                    ex < EXT_LAST_EXTENT(eh)) {  /*L2*/
3496                 /* See if we can merge right */
3497                 ext4_lblk_t next_lblk;
3498                 ext4_fsblk_t next_pblk, ee_pblk;
3499                 unsigned int next_len;
3500
3501                 abut_ex = ex + 1;
3502                 next_lblk = le32_to_cpu(abut_ex->ee_block);
3503                 next_len = ext4_ext_get_actual_len(abut_ex);
3504                 next_pblk = ext4_ext_pblock(abut_ex);
3505                 ee_pblk = ext4_ext_pblock(ex);
3506
3507                 /*
3508                  * A transfer of blocks from 'ex' to 'abut_ex' is allowed
3509                  * upon those conditions:
3510                  * - C1: abut_ex is initialized,
3511                  * - C2: abut_ex is logically abutting ex,
3512                  * - C3: abut_ex is physically abutting ex,
3513                  * - C4: abut_ex can receive the additional blocks without
3514                  *   overflowing the (initialized) length limit.
3515                  */
3516                 if ((!ext4_ext_is_unwritten(abut_ex)) &&                /*C1*/
3517                     ((map->m_lblk + map_len) == next_lblk) &&           /*C2*/
3518                     ((ee_pblk + ee_len) == next_pblk) &&                /*C3*/
3519                     (next_len < (EXT_INIT_MAX_LEN - map_len))) {        /*C4*/
3520                         err = ext4_ext_get_access(handle, inode, path + depth);
3521                         if (err)
3522                                 goto out;
3523
3524                         trace_ext4_ext_convert_to_initialized_fastpath(inode,
3525                                 map, ex, abut_ex);
3526
3527                         /* Shift the start of abut_ex by 'map_len' blocks */
3528                         abut_ex->ee_block = cpu_to_le32(next_lblk - map_len);
3529                         ext4_ext_store_pblock(abut_ex, next_pblk - map_len);
3530                         ex->ee_len = cpu_to_le16(ee_len - map_len);
3531                         ext4_ext_mark_unwritten(ex); /* Restore the flag */
3532
3533                         /* Extend abut_ex by 'map_len' blocks */
3534                         abut_ex->ee_len = cpu_to_le16(next_len + map_len);
3535
3536                         /* Result: number of initialized blocks past m_lblk */
3537                         allocated = map_len;
3538                 }
3539         }
3540         if (allocated) {
3541                 /* Mark the block containing both extents as dirty */
3542                 err = ext4_ext_dirty(handle, inode, path + depth);
3543
3544                 /* Update path to point to the right extent */
3545                 path[depth].p_ext = abut_ex;
3546                 goto out;
3547         } else
3548                 allocated = ee_len - (map->m_lblk - ee_block);
3549
3550         WARN_ON(map->m_lblk < ee_block);
3551         /*
3552          * It is safe to convert extent to initialized via explicit
3553          * zeroout only if extent is fully inside i_size or new_size.
3554          */
3555         split_flag |= ee_block + ee_len <= eof_block ? EXT4_EXT_MAY_ZEROOUT : 0;
3556
3557         if (EXT4_EXT_MAY_ZEROOUT & split_flag)
3558                 max_zeroout = sbi->s_extent_max_zeroout_kb >>
3559                         (inode->i_sb->s_blocksize_bits - 10);
3560
3561         /*
3562          * five cases:
3563          * 1. split the extent into three extents.
3564          * 2. split the extent into two extents, zeroout the head of the first
3565          *    extent.
3566          * 3. split the extent into two extents, zeroout the tail of the second
3567          *    extent.
3568          * 4. split the extent into two extents with out zeroout.
3569          * 5. no splitting needed, just possibly zeroout the head and / or the
3570          *    tail of the extent.
3571          */
3572         split_map.m_lblk = map->m_lblk;
3573         split_map.m_len = map->m_len;
3574
3575         if (max_zeroout && (allocated > split_map.m_len)) {
3576                 if (allocated <= max_zeroout) {
3577                         /* case 3 or 5 */
3578                         zero_ex1.ee_block =
3579                                  cpu_to_le32(split_map.m_lblk +
3580                                              split_map.m_len);
3581                         zero_ex1.ee_len =
3582                                 cpu_to_le16(allocated - split_map.m_len);
3583                         ext4_ext_store_pblock(&zero_ex1,
3584                                 ext4_ext_pblock(ex) + split_map.m_lblk +
3585                                 split_map.m_len - ee_block);
3586                         err = ext4_ext_zeroout(inode, &zero_ex1);
3587                         if (err)
3588                                 goto fallback;
3589                         split_map.m_len = allocated;
3590                 }
3591                 if (split_map.m_lblk - ee_block + split_map.m_len <
3592                                                                 max_zeroout) {
3593                         /* case 2 or 5 */
3594                         if (split_map.m_lblk != ee_block) {
3595                                 zero_ex2.ee_block = ex->ee_block;
3596                                 zero_ex2.ee_len = cpu_to_le16(split_map.m_lblk -
3597                                                         ee_block);
3598                                 ext4_ext_store_pblock(&zero_ex2,
3599                                                       ext4_ext_pblock(ex));
3600                                 err = ext4_ext_zeroout(inode, &zero_ex2);
3601                                 if (err)
3602                                         goto fallback;
3603                         }
3604
3605                         split_map.m_len += split_map.m_lblk - ee_block;
3606                         split_map.m_lblk = ee_block;
3607                         allocated = map->m_len;
3608                 }
3609         }
3610
3611 fallback:
3612         err = ext4_split_extent(handle, inode, ppath, &split_map, split_flag,
3613                                 flags);
3614         if (err > 0)
3615                 err = 0;
3616 out:
3617         /* If we have gotten a failure, don't zero out status tree */
3618         if (!err) {
3619                 ext4_zeroout_es(inode, &zero_ex1);
3620                 ext4_zeroout_es(inode, &zero_ex2);
3621         }
3622         return err ? err : allocated;
3623 }
3624
3625 /*
3626  * This function is called by ext4_ext_map_blocks() from
3627  * ext4_get_blocks_dio_write() when DIO to write
3628  * to an unwritten extent.
3629  *
3630  * Writing to an unwritten extent may result in splitting the unwritten
3631  * extent into multiple initialized/unwritten extents (up to three)
3632  * There are three possibilities:
3633  *   a> There is no split required: Entire extent should be unwritten
3634  *   b> Splits in two extents: Write is happening at either end of the extent
3635  *   c> Splits in three extents: Somone is writing in middle of the extent
3636  *
3637  * This works the same way in the case of initialized -> unwritten conversion.
3638  *
3639  * One of more index blocks maybe needed if the extent tree grow after
3640  * the unwritten extent split. To prevent ENOSPC occur at the IO
3641  * complete, we need to split the unwritten extent before DIO submit
3642  * the IO. The unwritten extent called at this time will be split
3643  * into three unwritten extent(at most). After IO complete, the part
3644  * being filled will be convert to initialized by the end_io callback function
3645  * via ext4_convert_unwritten_extents().
3646  *
3647  * Returns the size of unwritten extent to be written on success.
3648  */
3649 static int ext4_split_convert_extents(handle_t *handle,
3650                                         struct inode *inode,
3651                                         struct ext4_map_blocks *map,
3652                                         struct ext4_ext_path **ppath,
3653                                         int flags)
3654 {
3655         struct ext4_ext_path *path = *ppath;
3656         ext4_lblk_t eof_block;
3657         ext4_lblk_t ee_block;
3658         struct ext4_extent *ex;
3659         unsigned int ee_len;
3660         int split_flag = 0, depth;
3661
3662         ext_debug(inode, "logical block %llu, max_blocks %u\n",
3663                   (unsigned long long)map->m_lblk, map->m_len);
3664
3665         eof_block = (EXT4_I(inode)->i_disksize + inode->i_sb->s_blocksize - 1)
3666                         >> inode->i_sb->s_blocksize_bits;
3667         if (eof_block < map->m_lblk + map->m_len)
3668                 eof_block = map->m_lblk + map->m_len;
3669         /*
3670          * It is safe to convert extent to initialized via explicit
3671          * zeroout only if extent is fully inside i_size or new_size.
3672          */
3673         depth = ext_depth(inode);
3674         ex = path[depth].p_ext;
3675         ee_block = le32_to_cpu(ex->ee_block);
3676         ee_len = ext4_ext_get_actual_len(ex);
3677
3678         /* Convert to unwritten */
3679         if (flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN) {
3680                 split_flag |= EXT4_EXT_DATA_VALID1;
3681         /* Convert to initialized */
3682         } else if (flags & EXT4_GET_BLOCKS_CONVERT) {
3683                 split_flag |= ee_block + ee_len <= eof_block ?
3684                               EXT4_EXT_MAY_ZEROOUT : 0;
3685                 split_flag |= (EXT4_EXT_MARK_UNWRIT2 | EXT4_EXT_DATA_VALID2);
3686         }
3687         flags |= EXT4_GET_BLOCKS_PRE_IO;
3688         return ext4_split_extent(handle, inode, ppath, map, split_flag, flags);
3689 }
3690
3691 static int ext4_convert_unwritten_extents_endio(handle_t *handle,
3692                                                 struct inode *inode,
3693                                                 struct ext4_map_blocks *map,
3694                                                 struct ext4_ext_path **ppath)
3695 {
3696         struct ext4_ext_path *path = *ppath;
3697         struct ext4_extent *ex;
3698         ext4_lblk_t ee_block;
3699         unsigned int ee_len;
3700         int depth;
3701         int err = 0;
3702
3703         depth = ext_depth(inode);
3704         ex = path[depth].p_ext;
3705         ee_block = le32_to_cpu(ex->ee_block);
3706         ee_len = ext4_ext_get_actual_len(ex);
3707
3708         ext_debug(inode, "logical block %llu, max_blocks %u\n",
3709                   (unsigned long long)ee_block, ee_len);
3710
3711         /* If extent is larger than requested it is a clear sign that we still
3712          * have some extent state machine issues left. So extent_split is still
3713          * required.
3714          * TODO: Once all related issues will be fixed this situation should be
3715          * illegal.
3716          */
3717         if (ee_block != map->m_lblk || ee_len > map->m_len) {
3718 #ifdef CONFIG_EXT4_DEBUG
3719                 ext4_warning(inode->i_sb, "Inode (%ld) finished: extent logical block %llu,"
3720                              " len %u; IO logical block %llu, len %u",
3721                              inode->i_ino, (unsigned long long)ee_block, ee_len,
3722                              (unsigned long long)map->m_lblk, map->m_len);
3723 #endif
3724                 err = ext4_split_convert_extents(handle, inode, map, ppath,
3725                                                  EXT4_GET_BLOCKS_CONVERT);
3726                 if (err < 0)
3727                         return err;
3728                 path = ext4_find_extent(inode, map->m_lblk, ppath, 0);
3729                 if (IS_ERR(path))
3730                         return PTR_ERR(path);
3731                 depth = ext_depth(inode);
3732                 ex = path[depth].p_ext;
3733         }
3734
3735         err = ext4_ext_get_access(handle, inode, path + depth);
3736         if (err)
3737                 goto out;
3738         /* first mark the extent as initialized */
3739         ext4_ext_mark_initialized(ex);
3740
3741         /* note: ext4_ext_correct_indexes() isn't needed here because
3742          * borders are not changed
3743          */
3744         ext4_ext_try_to_merge(handle, inode, path, ex);
3745
3746         /* Mark modified extent as dirty */
3747         err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3748 out:
3749         ext4_ext_show_leaf(inode, path);
3750         return err;
3751 }
3752
3753 static int
3754 convert_initialized_extent(handle_t *handle, struct inode *inode,
3755                            struct ext4_map_blocks *map,
3756                            struct ext4_ext_path **ppath,
3757                            unsigned int *allocated)
3758 {
3759         struct ext4_ext_path *path = *ppath;
3760         struct ext4_extent *ex;
3761         ext4_lblk_t ee_block;
3762         unsigned int ee_len;
3763         int depth;
3764         int err = 0;
3765
3766         /*
3767          * Make sure that the extent is no bigger than we support with
3768          * unwritten extent
3769          */
3770         if (map->m_len > EXT_UNWRITTEN_MAX_LEN)
3771                 map->m_len = EXT_UNWRITTEN_MAX_LEN / 2;
3772
3773         depth = ext_depth(inode);
3774         ex = path[depth].p_ext;
3775         ee_block = le32_to_cpu(ex->ee_block);
3776         ee_len = ext4_ext_get_actual_len(ex);
3777
3778         ext_debug(inode, "logical block %llu, max_blocks %u\n",
3779                   (unsigned long long)ee_block, ee_len);
3780
3781         if (ee_block != map->m_lblk || ee_len > map->m_len) {
3782                 err = ext4_split_convert_extents(handle, inode, map, ppath,
3783                                 EXT4_GET_BLOCKS_CONVERT_UNWRITTEN);
3784                 if (err < 0)
3785                         return err;
3786                 path = ext4_find_extent(inode, map->m_lblk, ppath, 0);
3787                 if (IS_ERR(path))
3788                         return PTR_ERR(path);
3789                 depth = ext_depth(inode);
3790                 ex = path[depth].p_ext;
3791                 if (!ex) {
3792                         EXT4_ERROR_INODE(inode, "unexpected hole at %lu",
3793                                          (unsigned long) map->m_lblk);
3794                         return -EFSCORRUPTED;
3795                 }
3796         }
3797
3798         err = ext4_ext_get_access(handle, inode, path + depth);
3799         if (err)
3800                 return err;
3801         /* first mark the extent as unwritten */
3802         ext4_ext_mark_unwritten(ex);
3803
3804         /* note: ext4_ext_correct_indexes() isn't needed here because
3805          * borders are not changed
3806          */
3807         ext4_ext_try_to_merge(handle, inode, path, ex);
3808
3809         /* Mark modified extent as dirty */
3810         err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3811         if (err)
3812                 return err;
3813         ext4_ext_show_leaf(inode, path);
3814
3815         ext4_update_inode_fsync_trans(handle, inode, 1);
3816
3817         map->m_flags |= EXT4_MAP_UNWRITTEN;
3818         if (*allocated > map->m_len)
3819                 *allocated = map->m_len;
3820         map->m_len = *allocated;
3821         return 0;
3822 }
3823
3824 static int
3825 ext4_ext_handle_unwritten_extents(handle_t *handle, struct inode *inode,
3826                         struct ext4_map_blocks *map,
3827                         struct ext4_ext_path **ppath, int flags,
3828                         unsigned int allocated, ext4_fsblk_t newblock)
3829 {
3830         struct ext4_ext_path __maybe_unused *path = *ppath;
3831         int ret = 0;
3832         int err = 0;
3833
3834         ext_debug(inode, "logical block %llu, max_blocks %u, flags 0x%x, allocated %u\n",
3835                   (unsigned long long)map->m_lblk, map->m_len, flags,
3836                   allocated);
3837         ext4_ext_show_leaf(inode, path);
3838
3839         /*
3840          * When writing into unwritten space, we should not fail to
3841          * allocate metadata blocks for the new extent block if needed.
3842          */
3843         flags |= EXT4_GET_BLOCKS_METADATA_NOFAIL;
3844
3845         trace_ext4_ext_handle_unwritten_extents(inode, map, flags,
3846                                                     allocated, newblock);
3847
3848         /* get_block() before submitting IO, split the extent */
3849         if (flags & EXT4_GET_BLOCKS_PRE_IO) {
3850                 ret = ext4_split_convert_extents(handle, inode, map, ppath,
3851                                          flags | EXT4_GET_BLOCKS_CONVERT);
3852                 if (ret < 0) {
3853                         err = ret;
3854                         goto out2;
3855                 }
3856                 /*
3857                  * shouldn't get a 0 return when splitting an extent unless
3858                  * m_len is 0 (bug) or extent has been corrupted
3859                  */
3860                 if (unlikely(ret == 0)) {
3861                         EXT4_ERROR_INODE(inode,
3862                                          "unexpected ret == 0, m_len = %u",
3863                                          map->m_len);
3864                         err = -EFSCORRUPTED;
3865                         goto out2;
3866                 }
3867                 map->m_flags |= EXT4_MAP_UNWRITTEN;
3868                 goto out;
3869         }
3870         /* IO end_io complete, convert the filled extent to written */
3871         if (flags & EXT4_GET_BLOCKS_CONVERT) {
3872                 err = ext4_convert_unwritten_extents_endio(handle, inode, map,
3873                                                            ppath);
3874                 if (err < 0)
3875                         goto out2;
3876                 ext4_update_inode_fsync_trans(handle, inode, 1);
3877                 goto map_out;
3878         }
3879         /* buffered IO cases */
3880         /*
3881          * repeat fallocate creation request
3882          * we already have an unwritten extent
3883          */
3884         if (flags & EXT4_GET_BLOCKS_UNWRIT_EXT) {
3885                 map->m_flags |= EXT4_MAP_UNWRITTEN;
3886                 goto map_out;
3887         }
3888
3889         /* buffered READ or buffered write_begin() lookup */
3890         if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
3891                 /*
3892                  * We have blocks reserved already.  We
3893                  * return allocated blocks so that delalloc
3894                  * won't do block reservation for us.  But
3895                  * the buffer head will be unmapped so that
3896                  * a read from the block returns 0s.
3897                  */
3898                 map->m_flags |= EXT4_MAP_UNWRITTEN;
3899                 goto out1;
3900         }
3901
3902         /*
3903          * Default case when (flags & EXT4_GET_BLOCKS_CREATE) == 1.
3904          * For buffered writes, at writepage time, etc.  Convert a
3905          * discovered unwritten extent to written.
3906          */
3907         ret = ext4_ext_convert_to_initialized(handle, inode, map, ppath, flags);
3908         if (ret < 0) {
3909                 err = ret;
3910                 goto out2;
3911         }
3912         ext4_update_inode_fsync_trans(handle, inode, 1);
3913         /*
3914          * shouldn't get a 0 return when converting an unwritten extent
3915          * unless m_len is 0 (bug) or extent has been corrupted
3916          */
3917         if (unlikely(ret == 0)) {
3918                 EXT4_ERROR_INODE(inode, "unexpected ret == 0, m_len = %u",
3919                                  map->m_len);
3920                 err = -EFSCORRUPTED;
3921                 goto out2;
3922         }
3923
3924 out:
3925         allocated = ret;
3926         map->m_flags |= EXT4_MAP_NEW;
3927 map_out:
3928         map->m_flags |= EXT4_MAP_MAPPED;
3929 out1:
3930         map->m_pblk = newblock;
3931         if (allocated > map->m_len)
3932                 allocated = map->m_len;
3933         map->m_len = allocated;
3934         ext4_ext_show_leaf(inode, path);
3935 out2:
3936         return err ? err : allocated;
3937 }
3938
3939 /*
3940  * get_implied_cluster_alloc - check to see if the requested
3941  * allocation (in the map structure) overlaps with a cluster already
3942  * allocated in an extent.
3943  *      @sb     The filesystem superblock structure
3944  *      @map    The requested lblk->pblk mapping
3945  *      @ex     The extent structure which might contain an implied
3946  *                      cluster allocation
3947  *
3948  * This function is called by ext4_ext_map_blocks() after we failed to
3949  * find blocks that were already in the inode's extent tree.  Hence,
3950  * we know that the beginning of the requested region cannot overlap
3951  * the extent from the inode's extent tree.  There are three cases we
3952  * want to catch.  The first is this case:
3953  *
3954  *               |--- cluster # N--|
3955  *    |--- extent ---|  |---- requested region ---|
3956  *                      |==========|
3957  *
3958  * The second case that we need to test for is this one:
3959  *
3960  *   |--------- cluster # N ----------------|
3961  *         |--- requested region --|   |------- extent ----|
3962  *         |=======================|
3963  *
3964  * The third case is when the requested region lies between two extents
3965  * within the same cluster:
3966  *          |------------- cluster # N-------------|
3967  * |----- ex -----|                  |---- ex_right ----|
3968  *                  |------ requested region ------|
3969  *                  |================|
3970  *
3971  * In each of the above cases, we need to set the map->m_pblk and
3972  * map->m_len so it corresponds to the return the extent labelled as
3973  * "|====|" from cluster #N, since it is already in use for data in
3974  * cluster EXT4_B2C(sbi, map->m_lblk).  We will then return 1 to
3975  * signal to ext4_ext_map_blocks() that map->m_pblk should be treated
3976  * as a new "allocated" block region.  Otherwise, we will return 0 and
3977  * ext4_ext_map_blocks() will then allocate one or more new clusters
3978  * by calling ext4_mb_new_blocks().
3979  */
3980 static int get_implied_cluster_alloc(struct super_block *sb,
3981                                      struct ext4_map_blocks *map,
3982                                      struct ext4_extent *ex,
3983                                      struct ext4_ext_path *path)
3984 {
3985         struct ext4_sb_info *sbi = EXT4_SB(sb);
3986         ext4_lblk_t c_offset = EXT4_LBLK_COFF(sbi, map->m_lblk);
3987         ext4_lblk_t ex_cluster_start, ex_cluster_end;
3988         ext4_lblk_t rr_cluster_start;
3989         ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block);
3990         ext4_fsblk_t ee_start = ext4_ext_pblock(ex);
3991         unsigned short ee_len = ext4_ext_get_actual_len(ex);
3992
3993         /* The extent passed in that we are trying to match */
3994         ex_cluster_start = EXT4_B2C(sbi, ee_block);
3995         ex_cluster_end = EXT4_B2C(sbi, ee_block + ee_len - 1);
3996
3997         /* The requested region passed into ext4_map_blocks() */
3998         rr_cluster_start = EXT4_B2C(sbi, map->m_lblk);
3999
4000         if ((rr_cluster_start == ex_cluster_end) ||
4001             (rr_cluster_start == ex_cluster_start)) {
4002                 if (rr_cluster_start == ex_cluster_end)
4003                         ee_start += ee_len - 1;
4004                 map->m_pblk = EXT4_PBLK_CMASK(sbi, ee_start) + c_offset;
4005                 map->m_len = min(map->m_len,
4006                                  (unsigned) sbi->s_cluster_ratio - c_offset);
4007                 /*
4008                  * Check for and handle this case:
4009                  *
4010                  *   |--------- cluster # N-------------|
4011                  *                     |------- extent ----|
4012                  *         |--- requested region ---|
4013                  *         |===========|
4014                  */
4015
4016                 if (map->m_lblk < ee_block)
4017                         map->m_len = min(map->m_len, ee_block - map->m_lblk);
4018
4019                 /*
4020                  * Check for the case where there is already another allocated
4021                  * block to the right of 'ex' but before the end of the cluster.
4022                  *
4023                  *          |------------- cluster # N-------------|
4024                  * |----- ex -----|                  |---- ex_right ----|
4025                  *                  |------ requested region ------|
4026                  *                  |================|
4027                  */
4028                 if (map->m_lblk > ee_block) {
4029                         ext4_lblk_t next = ext4_ext_next_allocated_block(path);
4030                         map->m_len = min(map->m_len, next - map->m_lblk);
4031                 }
4032
4033                 trace_ext4_get_implied_cluster_alloc_exit(sb, map, 1);
4034                 return 1;
4035         }
4036
4037         trace_ext4_get_implied_cluster_alloc_exit(sb, map, 0);
4038         return 0;
4039 }
4040
4041 /*
4042  * Determine hole length around the given logical block, first try to
4043  * locate and expand the hole from the given @path, and then adjust it
4044  * if it's partially or completely converted to delayed extents, insert
4045  * it into the extent cache tree if it's indeed a hole, finally return
4046  * the length of the determined extent.
4047  */
4048 static ext4_lblk_t ext4_ext_determine_insert_hole(struct inode *inode,
4049                                                   struct ext4_ext_path *path,
4050                                                   ext4_lblk_t lblk)
4051 {
4052         ext4_lblk_t hole_start, len;
4053         struct extent_status es;
4054
4055         hole_start = lblk;
4056         len = ext4_ext_find_hole(inode, path, &hole_start);
4057 again:
4058         ext4_es_find_extent_range(inode, &ext4_es_is_delayed, hole_start,
4059                                   hole_start + len - 1, &es);
4060         if (!es.es_len)
4061                 goto insert_hole;
4062
4063         /*
4064          * There's a delalloc extent in the hole, handle it if the delalloc
4065          * extent is in front of, behind and straddle the queried range.
4066          */
4067         if (lblk >= es.es_lblk + es.es_len) {
4068                 /*
4069                  * The delalloc extent is in front of the queried range,
4070                  * find again from the queried start block.
4071                  */
4072                 len -= lblk - hole_start;
4073                 hole_start = lblk;
4074                 goto again;
4075         } else if (in_range(lblk, es.es_lblk, es.es_len)) {
4076                 /*
4077                  * The delalloc extent containing lblk, it must have been
4078                  * added after ext4_map_blocks() checked the extent status
4079                  * tree, adjust the length to the delalloc extent's after
4080                  * lblk.
4081                  */
4082                 len = es.es_lblk + es.es_len - lblk;
4083                 return len;
4084         } else {
4085                 /*
4086                  * The delalloc extent is partially or completely behind
4087                  * the queried range, update hole length until the
4088                  * beginning of the delalloc extent.
4089                  */
4090                 len = min(es.es_lblk - hole_start, len);
4091         }
4092
4093 insert_hole:
4094         /* Put just found gap into cache to speed up subsequent requests */
4095         ext_debug(inode, " -> %u:%u\n", hole_start, len);
4096         ext4_es_insert_extent(inode, hole_start, len, ~0, EXTENT_STATUS_HOLE);
4097
4098         /* Update hole_len to reflect hole size after lblk */
4099         if (hole_start != lblk)
4100                 len -= lblk - hole_start;
4101
4102         return len;
4103 }
4104
4105 /*
4106  * Block allocation/map/preallocation routine for extents based files
4107  *
4108  *
4109  * Need to be called with
4110  * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block
4111  * (ie, create is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem)
4112  *
4113  * return > 0, number of blocks already mapped/allocated
4114  *          if create == 0 and these are pre-allocated blocks
4115  *              buffer head is unmapped
4116  *          otherwise blocks are mapped
4117  *
4118  * return = 0, if plain look up failed (blocks have not been allocated)
4119  *          buffer head is unmapped
4120  *
4121  * return < 0, error case.
4122  */
4123 int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
4124                         struct ext4_map_blocks *map, int flags)
4125 {
4126         struct ext4_ext_path *path = NULL;
4127         struct ext4_extent newex, *ex, ex2;
4128         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
4129         ext4_fsblk_t newblock = 0, pblk;
4130         int err = 0, depth, ret;
4131         unsigned int allocated = 0, offset = 0;
4132         unsigned int allocated_clusters = 0;
4133         struct ext4_allocation_request ar;
4134         ext4_lblk_t cluster_offset;
4135
4136         ext_debug(inode, "blocks %u/%u requested\n", map->m_lblk, map->m_len);
4137         trace_ext4_ext_map_blocks_enter(inode, map->m_lblk, map->m_len, flags);
4138
4139         /* find extent for this block */
4140         path = ext4_find_extent(inode, map->m_lblk, NULL, 0);
4141         if (IS_ERR(path)) {
4142                 err = PTR_ERR(path);
4143                 path = NULL;
4144                 goto out;
4145         }
4146
4147         depth = ext_depth(inode);
4148
4149         /*
4150          * consistent leaf must not be empty;
4151          * this situation is possible, though, _during_ tree modification;
4152          * this is why assert can't be put in ext4_find_extent()
4153          */
4154         if (unlikely(path[depth].p_ext == NULL && depth != 0)) {
4155                 EXT4_ERROR_INODE(inode, "bad extent address "
4156                                  "lblock: %lu, depth: %d pblock %lld",
4157                                  (unsigned long) map->m_lblk, depth,
4158                                  path[depth].p_block);
4159                 err = -EFSCORRUPTED;
4160                 goto out;
4161         }
4162
4163         ex = path[depth].p_ext;
4164         if (ex) {
4165                 ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block);
4166                 ext4_fsblk_t ee_start = ext4_ext_pblock(ex);
4167                 unsigned short ee_len;
4168
4169
4170                 /*
4171                  * unwritten extents are treated as holes, except that
4172                  * we split out initialized portions during a write.
4173                  */
4174                 ee_len = ext4_ext_get_actual_len(ex);
4175
4176                 trace_ext4_ext_show_extent(inode, ee_block, ee_start, ee_len);
4177
4178                 /* if found extent covers block, simply return it */
4179                 if (in_range(map->m_lblk, ee_block, ee_len)) {
4180                         newblock = map->m_lblk - ee_block + ee_start;
4181                         /* number of remaining blocks in the extent */
4182                         allocated = ee_len - (map->m_lblk - ee_block);
4183                         ext_debug(inode, "%u fit into %u:%d -> %llu\n",
4184                                   map->m_lblk, ee_block, ee_len, newblock);
4185
4186                         /*
4187                          * If the extent is initialized check whether the
4188                          * caller wants to convert it to unwritten.
4189                          */
4190                         if ((!ext4_ext_is_unwritten(ex)) &&
4191                             (flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN)) {
4192                                 err = convert_initialized_extent(handle,
4193                                         inode, map, &path, &allocated);
4194                                 goto out;
4195                         } else if (!ext4_ext_is_unwritten(ex)) {
4196                                 map->m_flags |= EXT4_MAP_MAPPED;
4197                                 map->m_pblk = newblock;
4198                                 if (allocated > map->m_len)
4199                                         allocated = map->m_len;
4200                                 map->m_len = allocated;
4201                                 ext4_ext_show_leaf(inode, path);
4202                                 goto out;
4203                         }
4204
4205                         ret = ext4_ext_handle_unwritten_extents(
4206                                 handle, inode, map, &path, flags,
4207                                 allocated, newblock);
4208                         if (ret < 0)
4209                                 err = ret;
4210                         else
4211                                 allocated = ret;
4212                         goto out;
4213                 }
4214         }
4215
4216         /*
4217          * requested block isn't allocated yet;
4218          * we couldn't try to create block if create flag is zero
4219          */
4220         if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
4221                 ext4_lblk_t len;
4222
4223                 len = ext4_ext_determine_insert_hole(inode, path, map->m_lblk);
4224
4225                 map->m_pblk = 0;
4226                 map->m_len = min_t(unsigned int, map->m_len, len);
4227                 goto out;
4228         }
4229
4230         /*
4231          * Okay, we need to do block allocation.
4232          */
4233         newex.ee_block = cpu_to_le32(map->m_lblk);
4234         cluster_offset = EXT4_LBLK_COFF(sbi, map->m_lblk);
4235
4236         /*
4237          * If we are doing bigalloc, check to see if the extent returned
4238          * by ext4_find_extent() implies a cluster we can use.
4239          */
4240         if (cluster_offset && ex &&
4241             get_implied_cluster_alloc(inode->i_sb, map, ex, path)) {
4242                 ar.len = allocated = map->m_len;
4243                 newblock = map->m_pblk;
4244                 goto got_allocated_blocks;
4245         }
4246
4247         /* find neighbour allocated blocks */
4248         ar.lleft = map->m_lblk;
4249         err = ext4_ext_search_left(inode, path, &ar.lleft, &ar.pleft);
4250         if (err)
4251                 goto out;
4252         ar.lright = map->m_lblk;
4253         err = ext4_ext_search_right(inode, path, &ar.lright, &ar.pright, &ex2);
4254         if (err < 0)
4255                 goto out;
4256
4257         /* Check if the extent after searching to the right implies a
4258          * cluster we can use. */
4259         if ((sbi->s_cluster_ratio > 1) && err &&
4260             get_implied_cluster_alloc(inode->i_sb, map, &ex2, path)) {
4261                 ar.len = allocated = map->m_len;
4262                 newblock = map->m_pblk;
4263                 goto got_allocated_blocks;
4264         }
4265
4266         /*
4267          * See if request is beyond maximum number of blocks we can have in
4268          * a single extent. For an initialized extent this limit is
4269          * EXT_INIT_MAX_LEN and for an unwritten extent this limit is
4270          * EXT_UNWRITTEN_MAX_LEN.
4271          */
4272         if (map->m_len > EXT_INIT_MAX_LEN &&
4273             !(flags & EXT4_GET_BLOCKS_UNWRIT_EXT))
4274                 map->m_len = EXT_INIT_MAX_LEN;
4275         else if (map->m_len > EXT_UNWRITTEN_MAX_LEN &&
4276                  (flags & EXT4_GET_BLOCKS_UNWRIT_EXT))
4277                 map->m_len = EXT_UNWRITTEN_MAX_LEN;
4278
4279         /* Check if we can really insert (m_lblk)::(m_lblk + m_len) extent */
4280         newex.ee_len = cpu_to_le16(map->m_len);
4281         err = ext4_ext_check_overlap(sbi, inode, &newex, path);
4282         if (err)
4283                 allocated = ext4_ext_get_actual_len(&newex);
4284         else
4285                 allocated = map->m_len;
4286
4287         /* allocate new block */
4288         ar.inode = inode;
4289         ar.goal = ext4_ext_find_goal(inode, path, map->m_lblk);
4290         ar.logical = map->m_lblk;
4291         /*
4292          * We calculate the offset from the beginning of the cluster
4293          * for the logical block number, since when we allocate a
4294          * physical cluster, the physical block should start at the
4295          * same offset from the beginning of the cluster.  This is
4296          * needed so that future calls to get_implied_cluster_alloc()
4297          * work correctly.
4298          */
4299         offset = EXT4_LBLK_COFF(sbi, map->m_lblk);
4300         ar.len = EXT4_NUM_B2C(sbi, offset+allocated);
4301         ar.goal -= offset;
4302         ar.logical -= offset;
4303         if (S_ISREG(inode->i_mode))
4304                 ar.flags = EXT4_MB_HINT_DATA;
4305         else
4306                 /* disable in-core preallocation for non-regular files */
4307                 ar.flags = 0;
4308         if (flags & EXT4_GET_BLOCKS_NO_NORMALIZE)
4309                 ar.flags |= EXT4_MB_HINT_NOPREALLOC;
4310         if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
4311                 ar.flags |= EXT4_MB_DELALLOC_RESERVED;
4312         if (flags & EXT4_GET_BLOCKS_METADATA_NOFAIL)
4313                 ar.flags |= EXT4_MB_USE_RESERVED;
4314         newblock = ext4_mb_new_blocks(handle, &ar, &err);
4315         if (!newblock)
4316                 goto out;
4317         allocated_clusters = ar.len;
4318         ar.len = EXT4_C2B(sbi, ar.len) - offset;
4319         ext_debug(inode, "allocate new block: goal %llu, found %llu/%u, requested %u\n",
4320                   ar.goal, newblock, ar.len, allocated);
4321         if (ar.len > allocated)
4322                 ar.len = allocated;
4323
4324 got_allocated_blocks:
4325         /* try to insert new extent into found leaf and return */
4326         pblk = newblock + offset;
4327         ext4_ext_store_pblock(&newex, pblk);
4328         newex.ee_len = cpu_to_le16(ar.len);
4329         /* Mark unwritten */
4330         if (flags & EXT4_GET_BLOCKS_UNWRIT_EXT) {
4331                 ext4_ext_mark_unwritten(&newex);
4332                 map->m_flags |= EXT4_MAP_UNWRITTEN;
4333         }
4334
4335         err = ext4_ext_insert_extent(handle, inode, &path, &newex, flags);
4336         if (err) {
4337                 if (allocated_clusters) {
4338                         int fb_flags = 0;
4339
4340                         /*
4341                          * free data blocks we just allocated.
4342                          * not a good idea to call discard here directly,
4343                          * but otherwise we'd need to call it every free().
4344                          */
4345                         ext4_discard_preallocations(inode, 0);
4346                         if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
4347                                 fb_flags = EXT4_FREE_BLOCKS_NO_QUOT_UPDATE;
4348                         ext4_free_blocks(handle, inode, NULL, newblock,
4349                                          EXT4_C2B(sbi, allocated_clusters),
4350                                          fb_flags);
4351                 }
4352                 goto out;
4353         }
4354
4355         /*
4356          * Reduce the reserved cluster count to reflect successful deferred
4357          * allocation of delayed allocated clusters or direct allocation of
4358          * clusters discovered to be delayed allocated.  Once allocated, a
4359          * cluster is not included in the reserved count.
4360          */
4361         if (test_opt(inode->i_sb, DELALLOC) && allocated_clusters) {
4362                 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
4363                         /*
4364                          * When allocating delayed allocated clusters, simply
4365                          * reduce the reserved cluster count and claim quota
4366                          */
4367                         ext4_da_update_reserve_space(inode, allocated_clusters,
4368                                                         1);
4369                 } else {
4370                         ext4_lblk_t lblk, len;
4371                         unsigned int n;
4372
4373                         /*
4374                          * When allocating non-delayed allocated clusters
4375                          * (from fallocate, filemap, DIO, or clusters
4376                          * allocated when delalloc has been disabled by
4377                          * ext4_nonda_switch), reduce the reserved cluster
4378                          * count by the number of allocated clusters that
4379                          * have previously been delayed allocated.  Quota
4380                          * has been claimed by ext4_mb_new_blocks() above,
4381                          * so release the quota reservations made for any
4382                          * previously delayed allocated clusters.
4383                          */
4384                         lblk = EXT4_LBLK_CMASK(sbi, map->m_lblk);
4385                         len = allocated_clusters << sbi->s_cluster_bits;
4386                         n = ext4_es_delayed_clu(inode, lblk, len);
4387                         if (n > 0)
4388                                 ext4_da_update_reserve_space(inode, (int) n, 0);
4389                 }
4390         }
4391
4392         /*
4393          * Cache the extent and update transaction to commit on fdatasync only
4394          * when it is _not_ an unwritten extent.
4395          */
4396         if ((flags & EXT4_GET_BLOCKS_UNWRIT_EXT) == 0)
4397                 ext4_update_inode_fsync_trans(handle, inode, 1);
4398         else
4399                 ext4_update_inode_fsync_trans(handle, inode, 0);
4400
4401         map->m_flags |= (EXT4_MAP_NEW | EXT4_MAP_MAPPED);
4402         map->m_pblk = pblk;
4403         map->m_len = ar.len;
4404         allocated = map->m_len;
4405         ext4_ext_show_leaf(inode, path);
4406 out:
4407         ext4_free_ext_path(path);
4408
4409         trace_ext4_ext_map_blocks_exit(inode, flags, map,
4410                                        err ? err : allocated);
4411         return err ? err : allocated;
4412 }
4413
4414 int ext4_ext_truncate(handle_t *handle, struct inode *inode)
4415 {
4416         struct super_block *sb = inode->i_sb;
4417         ext4_lblk_t last_block;
4418         int err = 0;
4419
4420         /*
4421          * TODO: optimization is possible here.
4422          * Probably we need not scan at all,
4423          * because page truncation is enough.
4424          */
4425
4426         /* we have to know where to truncate from in crash case */
4427         EXT4_I(inode)->i_disksize = inode->i_size;
4428         err = ext4_mark_inode_dirty(handle, inode);
4429         if (err)
4430                 return err;
4431
4432         last_block = (inode->i_size + sb->s_blocksize - 1)
4433                         >> EXT4_BLOCK_SIZE_BITS(sb);
4434         ext4_es_remove_extent(inode, last_block, EXT_MAX_BLOCKS - last_block);
4435
4436 retry_remove_space:
4437         err = ext4_ext_remove_space(inode, last_block, EXT_MAX_BLOCKS - 1);
4438         if (err == -ENOMEM) {
4439                 memalloc_retry_wait(GFP_ATOMIC);
4440                 goto retry_remove_space;
4441         }
4442         return err;
4443 }
4444
4445 static int ext4_alloc_file_blocks(struct file *file, ext4_lblk_t offset,
4446                                   ext4_lblk_t len, loff_t new_size,
4447                                   int flags)
4448 {
4449         struct inode *inode = file_inode(file);
4450         handle_t *handle;
4451         int ret = 0, ret2 = 0, ret3 = 0;
4452         int retries = 0;
4453         int depth = 0;
4454         struct ext4_map_blocks map;
4455         unsigned int credits;
4456         loff_t epos;
4457
4458         BUG_ON(!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS));
4459         map.m_lblk = offset;
4460         map.m_len = len;
4461         /*
4462          * Don't normalize the request if it can fit in one extent so
4463          * that it doesn't get unnecessarily split into multiple
4464          * extents.
4465          */
4466         if (len <= EXT_UNWRITTEN_MAX_LEN)
4467                 flags |= EXT4_GET_BLOCKS_NO_NORMALIZE;
4468
4469         /*
4470          * credits to insert 1 extent into extent tree
4471          */
4472         credits = ext4_chunk_trans_blocks(inode, len);
4473         depth = ext_depth(inode);
4474
4475 retry:
4476         while (len) {
4477                 /*
4478                  * Recalculate credits when extent tree depth changes.
4479                  */
4480                 if (depth != ext_depth(inode)) {
4481                         credits = ext4_chunk_trans_blocks(inode, len);
4482                         depth = ext_depth(inode);
4483                 }
4484
4485                 handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS,
4486                                             credits);
4487                 if (IS_ERR(handle)) {
4488                         ret = PTR_ERR(handle);
4489                         break;
4490                 }
4491                 ret = ext4_map_blocks(handle, inode, &map, flags);
4492                 if (ret <= 0) {
4493                         ext4_debug("inode #%lu: block %u: len %u: "
4494                                    "ext4_ext_map_blocks returned %d",
4495                                    inode->i_ino, map.m_lblk,
4496                                    map.m_len, ret);
4497                         ext4_mark_inode_dirty(handle, inode);
4498                         ext4_journal_stop(handle);
4499                         break;
4500                 }
4501                 /*
4502                  * allow a full retry cycle for any remaining allocations
4503                  */
4504                 retries = 0;
4505                 map.m_lblk += ret;
4506                 map.m_len = len = len - ret;
4507                 epos = (loff_t)map.m_lblk << inode->i_blkbits;
4508                 inode_set_ctime_current(inode);
4509                 if (new_size) {
4510                         if (epos > new_size)
4511                                 epos = new_size;
4512                         if (ext4_update_inode_size(inode, epos) & 0x1)
4513                                 inode_set_mtime_to_ts(inode,
4514                                                       inode_get_ctime(inode));
4515                 }
4516                 ret2 = ext4_mark_inode_dirty(handle, inode);
4517                 ext4_update_inode_fsync_trans(handle, inode, 1);
4518                 ret3 = ext4_journal_stop(handle);
4519                 ret2 = ret3 ? ret3 : ret2;
4520                 if (unlikely(ret2))
4521                         break;
4522         }
4523         if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
4524                 goto retry;
4525
4526         return ret > 0 ? ret2 : ret;
4527 }
4528
4529 static int ext4_collapse_range(struct file *file, loff_t offset, loff_t len);
4530
4531 static int ext4_insert_range(struct file *file, loff_t offset, loff_t len);
4532
4533 static long ext4_zero_range(struct file *file, loff_t offset,
4534                             loff_t len, int mode)
4535 {
4536         struct inode *inode = file_inode(file);
4537         struct address_space *mapping = file->f_mapping;
4538         handle_t *handle = NULL;
4539         unsigned int max_blocks;
4540         loff_t new_size = 0;
4541         int ret = 0;
4542         int flags;
4543         int credits;
4544         int partial_begin, partial_end;
4545         loff_t start, end;
4546         ext4_lblk_t lblk;
4547         unsigned int blkbits = inode->i_blkbits;
4548
4549         trace_ext4_zero_range(inode, offset, len, mode);
4550
4551         /*
4552          * Round up offset. This is not fallocate, we need to zero out
4553          * blocks, so convert interior block aligned part of the range to
4554          * unwritten and possibly manually zero out unaligned parts of the
4555          * range. Here, start and partial_begin are inclusive, end and
4556          * partial_end are exclusive.
4557          */
4558         start = round_up(offset, 1 << blkbits);
4559         end = round_down((offset + len), 1 << blkbits);
4560
4561         if (start < offset || end > offset + len)
4562                 return -EINVAL;
4563         partial_begin = offset & ((1 << blkbits) - 1);
4564         partial_end = (offset + len) & ((1 << blkbits) - 1);
4565
4566         lblk = start >> blkbits;
4567         max_blocks = (end >> blkbits);
4568         if (max_blocks < lblk)
4569                 max_blocks = 0;
4570         else
4571                 max_blocks -= lblk;
4572
4573         inode_lock(inode);
4574
4575         /*
4576          * Indirect files do not support unwritten extents
4577          */
4578         if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
4579                 ret = -EOPNOTSUPP;
4580                 goto out_mutex;
4581         }
4582
4583         if (!(mode & FALLOC_FL_KEEP_SIZE) &&
4584             (offset + len > inode->i_size ||
4585              offset + len > EXT4_I(inode)->i_disksize)) {
4586                 new_size = offset + len;
4587                 ret = inode_newsize_ok(inode, new_size);
4588                 if (ret)
4589                         goto out_mutex;
4590         }
4591
4592         flags = EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT;
4593
4594         /* Wait all existing dio workers, newcomers will block on i_rwsem */
4595         inode_dio_wait(inode);
4596
4597         ret = file_modified(file);
4598         if (ret)
4599                 goto out_mutex;
4600
4601         /* Preallocate the range including the unaligned edges */
4602         if (partial_begin || partial_end) {
4603                 ret = ext4_alloc_file_blocks(file,
4604                                 round_down(offset, 1 << blkbits) >> blkbits,
4605                                 (round_up((offset + len), 1 << blkbits) -
4606                                  round_down(offset, 1 << blkbits)) >> blkbits,
4607                                 new_size, flags);
4608                 if (ret)
4609                         goto out_mutex;
4610
4611         }
4612
4613         /* Zero range excluding the unaligned edges */
4614         if (max_blocks > 0) {
4615                 flags |= (EXT4_GET_BLOCKS_CONVERT_UNWRITTEN |
4616                           EXT4_EX_NOCACHE);
4617
4618                 /*
4619                  * Prevent page faults from reinstantiating pages we have
4620                  * released from page cache.
4621                  */
4622                 filemap_invalidate_lock(mapping);
4623
4624                 ret = ext4_break_layouts(inode);
4625                 if (ret) {
4626                         filemap_invalidate_unlock(mapping);
4627                         goto out_mutex;
4628                 }
4629
4630                 ret = ext4_update_disksize_before_punch(inode, offset, len);
4631                 if (ret) {
4632                         filemap_invalidate_unlock(mapping);
4633                         goto out_mutex;
4634                 }
4635
4636                 /*
4637                  * For journalled data we need to write (and checkpoint) pages
4638                  * before discarding page cache to avoid inconsitent data on
4639                  * disk in case of crash before zeroing trans is committed.
4640                  */
4641                 if (ext4_should_journal_data(inode)) {
4642                         ret = filemap_write_and_wait_range(mapping, start,
4643                                                            end - 1);
4644                         if (ret) {
4645                                 filemap_invalidate_unlock(mapping);
4646                                 goto out_mutex;
4647                         }
4648                 }
4649
4650                 /* Now release the pages and zero block aligned part of pages */
4651                 truncate_pagecache_range(inode, start, end - 1);
4652                 inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
4653
4654                 ret = ext4_alloc_file_blocks(file, lblk, max_blocks, new_size,
4655                                              flags);
4656                 filemap_invalidate_unlock(mapping);
4657                 if (ret)
4658                         goto out_mutex;
4659         }
4660         if (!partial_begin && !partial_end)
4661                 goto out_mutex;
4662
4663         /*
4664          * In worst case we have to writeout two nonadjacent unwritten
4665          * blocks and update the inode
4666          */
4667         credits = (2 * ext4_ext_index_trans_blocks(inode, 2)) + 1;
4668         if (ext4_should_journal_data(inode))
4669                 credits += 2;
4670         handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
4671         if (IS_ERR(handle)) {
4672                 ret = PTR_ERR(handle);
4673                 ext4_std_error(inode->i_sb, ret);
4674                 goto out_mutex;
4675         }
4676
4677         inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
4678         if (new_size)
4679                 ext4_update_inode_size(inode, new_size);
4680         ret = ext4_mark_inode_dirty(handle, inode);
4681         if (unlikely(ret))
4682                 goto out_handle;
4683         /* Zero out partial block at the edges of the range */
4684         ret = ext4_zero_partial_blocks(handle, inode, offset, len);
4685         if (ret >= 0)
4686                 ext4_update_inode_fsync_trans(handle, inode, 1);
4687
4688         if (file->f_flags & O_SYNC)
4689                 ext4_handle_sync(handle);
4690
4691 out_handle:
4692         ext4_journal_stop(handle);
4693 out_mutex:
4694         inode_unlock(inode);
4695         return ret;
4696 }
4697
4698 /*
4699  * preallocate space for a file. This implements ext4's fallocate file
4700  * operation, which gets called from sys_fallocate system call.
4701  * For block-mapped files, posix_fallocate should fall back to the method
4702  * of writing zeroes to the required new blocks (the same behavior which is
4703  * expected for file systems which do not support fallocate() system call).
4704  */
4705 long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
4706 {
4707         struct inode *inode = file_inode(file);
4708         loff_t new_size = 0;
4709         unsigned int max_blocks;
4710         int ret = 0;
4711         int flags;
4712         ext4_lblk_t lblk;
4713         unsigned int blkbits = inode->i_blkbits;
4714
4715         /*
4716          * Encrypted inodes can't handle collapse range or insert
4717          * range since we would need to re-encrypt blocks with a
4718          * different IV or XTS tweak (which are based on the logical
4719          * block number).
4720          */
4721         if (IS_ENCRYPTED(inode) &&
4722             (mode & (FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_INSERT_RANGE)))
4723                 return -EOPNOTSUPP;
4724
4725         /* Return error if mode is not supported */
4726         if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |
4727                      FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE |
4728                      FALLOC_FL_INSERT_RANGE))
4729                 return -EOPNOTSUPP;
4730
4731         inode_lock(inode);
4732         ret = ext4_convert_inline_data(inode);
4733         inode_unlock(inode);
4734         if (ret)
4735                 goto exit;
4736
4737         if (mode & FALLOC_FL_PUNCH_HOLE) {
4738                 ret = ext4_punch_hole(file, offset, len);
4739                 goto exit;
4740         }
4741
4742         if (mode & FALLOC_FL_COLLAPSE_RANGE) {
4743                 ret = ext4_collapse_range(file, offset, len);
4744                 goto exit;
4745         }
4746
4747         if (mode & FALLOC_FL_INSERT_RANGE) {
4748                 ret = ext4_insert_range(file, offset, len);
4749                 goto exit;
4750         }
4751
4752         if (mode & FALLOC_FL_ZERO_RANGE) {
4753                 ret = ext4_zero_range(file, offset, len, mode);
4754                 goto exit;
4755         }
4756         trace_ext4_fallocate_enter(inode, offset, len, mode);
4757         lblk = offset >> blkbits;
4758
4759         max_blocks = EXT4_MAX_BLOCKS(len, offset, blkbits);
4760         flags = EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT;
4761
4762         inode_lock(inode);
4763
4764         /*
4765          * We only support preallocation for extent-based files only
4766          */
4767         if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
4768                 ret = -EOPNOTSUPP;
4769                 goto out;
4770         }
4771
4772         if (!(mode & FALLOC_FL_KEEP_SIZE) &&
4773             (offset + len > inode->i_size ||
4774              offset + len > EXT4_I(inode)->i_disksize)) {
4775                 new_size = offset + len;
4776                 ret = inode_newsize_ok(inode, new_size);
4777                 if (ret)
4778                         goto out;
4779         }
4780
4781         /* Wait all existing dio workers, newcomers will block on i_rwsem */
4782         inode_dio_wait(inode);
4783
4784         ret = file_modified(file);
4785         if (ret)
4786                 goto out;
4787
4788         ret = ext4_alloc_file_blocks(file, lblk, max_blocks, new_size, flags);
4789         if (ret)
4790                 goto out;
4791
4792         if (file->f_flags & O_SYNC && EXT4_SB(inode->i_sb)->s_journal) {
4793                 ret = ext4_fc_commit(EXT4_SB(inode->i_sb)->s_journal,
4794                                         EXT4_I(inode)->i_sync_tid);
4795         }
4796 out:
4797         inode_unlock(inode);
4798         trace_ext4_fallocate_exit(inode, offset, max_blocks, ret);
4799 exit:
4800         return ret;
4801 }
4802
4803 /*
4804  * This function convert a range of blocks to written extents
4805  * The caller of this function will pass the start offset and the size.
4806  * all unwritten extents within this range will be converted to
4807  * written extents.
4808  *
4809  * This function is called from the direct IO end io call back
4810  * function, to convert the fallocated extents after IO is completed.
4811  * Returns 0 on success.
4812  */
4813 int ext4_convert_unwritten_extents(handle_t *handle, struct inode *inode,
4814                                    loff_t offset, ssize_t len)
4815 {
4816         unsigned int max_blocks;
4817         int ret = 0, ret2 = 0, ret3 = 0;
4818         struct ext4_map_blocks map;
4819         unsigned int blkbits = inode->i_blkbits;
4820         unsigned int credits = 0;
4821
4822         map.m_lblk = offset >> blkbits;
4823         max_blocks = EXT4_MAX_BLOCKS(len, offset, blkbits);
4824
4825         if (!handle) {
4826                 /*
4827                  * credits to insert 1 extent into extent tree
4828                  */
4829                 credits = ext4_chunk_trans_blocks(inode, max_blocks);
4830         }
4831         while (ret >= 0 && ret < max_blocks) {
4832                 map.m_lblk += ret;
4833                 map.m_len = (max_blocks -= ret);
4834                 if (credits) {
4835                         handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS,
4836                                                     credits);
4837                         if (IS_ERR(handle)) {
4838                                 ret = PTR_ERR(handle);
4839                                 break;
4840                         }
4841                 }
4842                 ret = ext4_map_blocks(handle, inode, &map,
4843                                       EXT4_GET_BLOCKS_IO_CONVERT_EXT);
4844                 if (ret <= 0)
4845                         ext4_warning(inode->i_sb,
4846                                      "inode #%lu: block %u: len %u: "
4847                                      "ext4_ext_map_blocks returned %d",
4848                                      inode->i_ino, map.m_lblk,
4849                                      map.m_len, ret);
4850                 ret2 = ext4_mark_inode_dirty(handle, inode);
4851                 if (credits) {
4852                         ret3 = ext4_journal_stop(handle);
4853                         if (unlikely(ret3))
4854                                 ret2 = ret3;
4855                 }
4856
4857                 if (ret <= 0 || ret2)
4858                         break;
4859         }
4860         return ret > 0 ? ret2 : ret;
4861 }
4862
4863 int ext4_convert_unwritten_io_end_vec(handle_t *handle, ext4_io_end_t *io_end)
4864 {
4865         int ret = 0, err = 0;
4866         struct ext4_io_end_vec *io_end_vec;
4867
4868         /*
4869          * This is somewhat ugly but the idea is clear: When transaction is
4870          * reserved, everything goes into it. Otherwise we rather start several
4871          * smaller transactions for conversion of each extent separately.
4872          */
4873         if (handle) {
4874                 handle = ext4_journal_start_reserved(handle,
4875                                                      EXT4_HT_EXT_CONVERT);
4876                 if (IS_ERR(handle))
4877                         return PTR_ERR(handle);
4878         }
4879
4880         list_for_each_entry(io_end_vec, &io_end->list_vec, list) {
4881                 ret = ext4_convert_unwritten_extents(handle, io_end->inode,
4882                                                      io_end_vec->offset,
4883                                                      io_end_vec->size);
4884                 if (ret)
4885                         break;
4886         }
4887
4888         if (handle)
4889                 err = ext4_journal_stop(handle);
4890
4891         return ret < 0 ? ret : err;
4892 }
4893
4894 static int ext4_iomap_xattr_fiemap(struct inode *inode, struct iomap *iomap)
4895 {
4896         __u64 physical = 0;
4897         __u64 length = 0;
4898         int blockbits = inode->i_sb->s_blocksize_bits;
4899         int error = 0;
4900         u16 iomap_type;
4901
4902         /* in-inode? */
4903         if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
4904                 struct ext4_iloc iloc;
4905                 int offset;     /* offset of xattr in inode */
4906
4907                 error = ext4_get_inode_loc(inode, &iloc);
4908                 if (error)
4909                         return error;
4910                 physical = (__u64)iloc.bh->b_blocknr << blockbits;
4911                 offset = EXT4_GOOD_OLD_INODE_SIZE +
4912                                 EXT4_I(inode)->i_extra_isize;
4913                 physical += offset;
4914                 length = EXT4_SB(inode->i_sb)->s_inode_size - offset;
4915                 brelse(iloc.bh);
4916                 iomap_type = IOMAP_INLINE;
4917         } else if (EXT4_I(inode)->i_file_acl) { /* external block */
4918                 physical = (__u64)EXT4_I(inode)->i_file_acl << blockbits;
4919                 length = inode->i_sb->s_blocksize;
4920                 iomap_type = IOMAP_MAPPED;
4921         } else {
4922                 /* no in-inode or external block for xattr, so return -ENOENT */
4923                 error = -ENOENT;
4924                 goto out;
4925         }
4926
4927         iomap->addr = physical;
4928         iomap->offset = 0;
4929         iomap->length = length;
4930         iomap->type = iomap_type;
4931         iomap->flags = 0;
4932 out:
4933         return error;
4934 }
4935
4936 static int ext4_iomap_xattr_begin(struct inode *inode, loff_t offset,
4937                                   loff_t length, unsigned flags,
4938                                   struct iomap *iomap, struct iomap *srcmap)
4939 {
4940         int error;
4941
4942         error = ext4_iomap_xattr_fiemap(inode, iomap);
4943         if (error == 0 && (offset >= iomap->length))
4944                 error = -ENOENT;
4945         return error;
4946 }
4947
4948 static const struct iomap_ops ext4_iomap_xattr_ops = {
4949         .iomap_begin            = ext4_iomap_xattr_begin,
4950 };
4951
4952 static int ext4_fiemap_check_ranges(struct inode *inode, u64 start, u64 *len)
4953 {
4954         u64 maxbytes;
4955
4956         if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
4957                 maxbytes = inode->i_sb->s_maxbytes;
4958         else
4959                 maxbytes = EXT4_SB(inode->i_sb)->s_bitmap_maxbytes;
4960
4961         if (*len == 0)
4962                 return -EINVAL;
4963         if (start > maxbytes)
4964                 return -EFBIG;
4965
4966         /*
4967          * Shrink request scope to what the fs can actually handle.
4968          */
4969         if (*len > maxbytes || (maxbytes - *len) < start)
4970                 *len = maxbytes - start;
4971         return 0;
4972 }
4973
4974 int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
4975                 u64 start, u64 len)
4976 {
4977         int error = 0;
4978
4979         if (fieinfo->fi_flags & FIEMAP_FLAG_CACHE) {
4980                 error = ext4_ext_precache(inode);
4981                 if (error)
4982                         return error;
4983                 fieinfo->fi_flags &= ~FIEMAP_FLAG_CACHE;
4984         }
4985
4986         /*
4987          * For bitmap files the maximum size limit could be smaller than
4988          * s_maxbytes, so check len here manually instead of just relying on the
4989          * generic check.
4990          */
4991         error = ext4_fiemap_check_ranges(inode, start, &len);
4992         if (error)
4993                 return error;
4994
4995         if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) {
4996                 fieinfo->fi_flags &= ~FIEMAP_FLAG_XATTR;
4997                 return iomap_fiemap(inode, fieinfo, start, len,
4998                                     &ext4_iomap_xattr_ops);
4999         }
5000
5001         return iomap_fiemap(inode, fieinfo, start, len, &ext4_iomap_report_ops);
5002 }
5003
5004 int ext4_get_es_cache(struct inode *inode, struct fiemap_extent_info *fieinfo,
5005                       __u64 start, __u64 len)
5006 {
5007         ext4_lblk_t start_blk, len_blks;
5008         __u64 last_blk;
5009         int error = 0;
5010
5011         if (ext4_has_inline_data(inode)) {
5012                 int has_inline;
5013
5014                 down_read(&EXT4_I(inode)->xattr_sem);
5015                 has_inline = ext4_has_inline_data(inode);
5016                 up_read(&EXT4_I(inode)->xattr_sem);
5017                 if (has_inline)
5018                         return 0;
5019         }
5020
5021         if (fieinfo->fi_flags & FIEMAP_FLAG_CACHE) {
5022                 error = ext4_ext_precache(inode);
5023                 if (error)
5024                         return error;
5025                 fieinfo->fi_flags &= ~FIEMAP_FLAG_CACHE;
5026         }
5027
5028         error = fiemap_prep(inode, fieinfo, start, &len, 0);
5029         if (error)
5030                 return error;
5031
5032         error = ext4_fiemap_check_ranges(inode, start, &len);
5033         if (error)
5034                 return error;
5035
5036         start_blk = start >> inode->i_sb->s_blocksize_bits;
5037         last_blk = (start + len - 1) >> inode->i_sb->s_blocksize_bits;
5038         if (last_blk >= EXT_MAX_BLOCKS)
5039                 last_blk = EXT_MAX_BLOCKS-1;
5040         len_blks = ((ext4_lblk_t) last_blk) - start_blk + 1;
5041
5042         /*
5043          * Walk the extent tree gathering extent information
5044          * and pushing extents back to the user.
5045          */
5046         return ext4_fill_es_cache_info(inode, start_blk, len_blks, fieinfo);
5047 }
5048
5049 /*
5050  * ext4_ext_shift_path_extents:
5051  * Shift the extents of a path structure lying between path[depth].p_ext
5052  * and EXT_LAST_EXTENT(path[depth].p_hdr), by @shift blocks. @SHIFT tells
5053  * if it is right shift or left shift operation.
5054  */
5055 static int
5056 ext4_ext_shift_path_extents(struct ext4_ext_path *path, ext4_lblk_t shift,
5057                             struct inode *inode, handle_t *handle,
5058                             enum SHIFT_DIRECTION SHIFT)
5059 {
5060         int depth, err = 0;
5061         struct ext4_extent *ex_start, *ex_last;
5062         bool update = false;
5063         int credits, restart_credits;
5064         depth = path->p_depth;
5065
5066         while (depth >= 0) {
5067                 if (depth == path->p_depth) {
5068                         ex_start = path[depth].p_ext;
5069                         if (!ex_start)
5070                                 return -EFSCORRUPTED;
5071
5072                         ex_last = EXT_LAST_EXTENT(path[depth].p_hdr);
5073                         /* leaf + sb + inode */
5074                         credits = 3;
5075                         if (ex_start == EXT_FIRST_EXTENT(path[depth].p_hdr)) {
5076                                 update = true;
5077                                 /* extent tree + sb + inode */
5078                                 credits = depth + 2;
5079                         }
5080
5081                         restart_credits = ext4_writepage_trans_blocks(inode);
5082                         err = ext4_datasem_ensure_credits(handle, inode, credits,
5083                                         restart_credits, 0);
5084                         if (err) {
5085                                 if (err > 0)
5086                                         err = -EAGAIN;
5087                                 goto out;
5088                         }
5089
5090                         err = ext4_ext_get_access(handle, inode, path + depth);
5091                         if (err)
5092                                 goto out;
5093
5094                         while (ex_start <= ex_last) {
5095                                 if (SHIFT == SHIFT_LEFT) {
5096                                         le32_add_cpu(&ex_start->ee_block,
5097                                                 -shift);
5098                                         /* Try to merge to the left. */
5099                                         if ((ex_start >
5100                                             EXT_FIRST_EXTENT(path[depth].p_hdr))
5101                                             &&
5102                                             ext4_ext_try_to_merge_right(inode,
5103                                             path, ex_start - 1))
5104                                                 ex_last--;
5105                                         else
5106                                                 ex_start++;
5107                                 } else {
5108                                         le32_add_cpu(&ex_last->ee_block, shift);
5109                                         ext4_ext_try_to_merge_right(inode, path,
5110                                                 ex_last);
5111                                         ex_last--;
5112                                 }
5113                         }
5114                         err = ext4_ext_dirty(handle, inode, path + depth);
5115                         if (err)
5116                                 goto out;
5117
5118                         if (--depth < 0 || !update)
5119                                 break;
5120                 }
5121
5122                 /* Update index too */
5123                 err = ext4_ext_get_access(handle, inode, path + depth);
5124                 if (err)
5125                         goto out;
5126
5127                 if (SHIFT == SHIFT_LEFT)
5128                         le32_add_cpu(&path[depth].p_idx->ei_block, -shift);
5129                 else
5130                         le32_add_cpu(&path[depth].p_idx->ei_block, shift);
5131                 err = ext4_ext_dirty(handle, inode, path + depth);
5132                 if (err)
5133                         goto out;
5134
5135                 /* we are done if current index is not a starting index */
5136                 if (path[depth].p_idx != EXT_FIRST_INDEX(path[depth].p_hdr))
5137                         break;
5138
5139                 depth--;
5140         }
5141
5142 out:
5143         return err;
5144 }
5145
5146 /*
5147  * ext4_ext_shift_extents:
5148  * All the extents which lies in the range from @start to the last allocated
5149  * block for the @inode are shifted either towards left or right (depending
5150  * upon @SHIFT) by @shift blocks.
5151  * On success, 0 is returned, error otherwise.
5152  */
5153 static int
5154 ext4_ext_shift_extents(struct inode *inode, handle_t *handle,
5155                        ext4_lblk_t start, ext4_lblk_t shift,
5156                        enum SHIFT_DIRECTION SHIFT)
5157 {
5158         struct ext4_ext_path *path;
5159         int ret = 0, depth;
5160         struct ext4_extent *extent;
5161         ext4_lblk_t stop, *iterator, ex_start, ex_end;
5162         ext4_lblk_t tmp = EXT_MAX_BLOCKS;
5163
5164         /* Let path point to the last extent */
5165         path = ext4_find_extent(inode, EXT_MAX_BLOCKS - 1, NULL,
5166                                 EXT4_EX_NOCACHE);
5167         if (IS_ERR(path))
5168                 return PTR_ERR(path);
5169
5170         depth = path->p_depth;
5171         extent = path[depth].p_ext;
5172         if (!extent)
5173                 goto out;
5174
5175         stop = le32_to_cpu(extent->ee_block);
5176
5177        /*
5178         * For left shifts, make sure the hole on the left is big enough to
5179         * accommodate the shift.  For right shifts, make sure the last extent
5180         * won't be shifted beyond EXT_MAX_BLOCKS.
5181         */
5182         if (SHIFT == SHIFT_LEFT) {
5183                 path = ext4_find_extent(inode, start - 1, &path,
5184                                         EXT4_EX_NOCACHE);
5185                 if (IS_ERR(path))
5186                         return PTR_ERR(path);
5187                 depth = path->p_depth;
5188                 extent =  path[depth].p_ext;
5189                 if (extent) {
5190                         ex_start = le32_to_cpu(extent->ee_block);
5191                         ex_end = le32_to_cpu(extent->ee_block) +
5192                                 ext4_ext_get_actual_len(extent);
5193                 } else {
5194                         ex_start = 0;
5195                         ex_end = 0;
5196                 }
5197
5198                 if ((start == ex_start && shift > ex_start) ||
5199                     (shift > start - ex_end)) {
5200                         ret = -EINVAL;
5201                         goto out;
5202                 }
5203         } else {
5204                 if (shift > EXT_MAX_BLOCKS -
5205                     (stop + ext4_ext_get_actual_len(extent))) {
5206                         ret = -EINVAL;
5207                         goto out;
5208                 }
5209         }
5210
5211         /*
5212          * In case of left shift, iterator points to start and it is increased
5213          * till we reach stop. In case of right shift, iterator points to stop
5214          * and it is decreased till we reach start.
5215          */
5216 again:
5217         ret = 0;
5218         if (SHIFT == SHIFT_LEFT)
5219                 iterator = &start;
5220         else
5221                 iterator = &stop;
5222
5223         if (tmp != EXT_MAX_BLOCKS)
5224                 *iterator = tmp;
5225
5226         /*
5227          * Its safe to start updating extents.  Start and stop are unsigned, so
5228          * in case of right shift if extent with 0 block is reached, iterator
5229          * becomes NULL to indicate the end of the loop.
5230          */
5231         while (iterator && start <= stop) {
5232                 path = ext4_find_extent(inode, *iterator, &path,
5233                                         EXT4_EX_NOCACHE);
5234                 if (IS_ERR(path))
5235                         return PTR_ERR(path);
5236                 depth = path->p_depth;
5237                 extent = path[depth].p_ext;
5238                 if (!extent) {
5239                         EXT4_ERROR_INODE(inode, "unexpected hole at %lu",
5240                                          (unsigned long) *iterator);
5241                         return -EFSCORRUPTED;
5242                 }
5243                 if (SHIFT == SHIFT_LEFT && *iterator >
5244                     le32_to_cpu(extent->ee_block)) {
5245                         /* Hole, move to the next extent */
5246                         if (extent < EXT_LAST_EXTENT(path[depth].p_hdr)) {
5247                                 path[depth].p_ext++;
5248                         } else {
5249                                 *iterator = ext4_ext_next_allocated_block(path);
5250                                 continue;
5251                         }
5252                 }
5253
5254                 tmp = *iterator;
5255                 if (SHIFT == SHIFT_LEFT) {
5256                         extent = EXT_LAST_EXTENT(path[depth].p_hdr);
5257                         *iterator = le32_to_cpu(extent->ee_block) +
5258                                         ext4_ext_get_actual_len(extent);
5259                 } else {
5260                         extent = EXT_FIRST_EXTENT(path[depth].p_hdr);
5261                         if (le32_to_cpu(extent->ee_block) > start)
5262                                 *iterator = le32_to_cpu(extent->ee_block) - 1;
5263                         else if (le32_to_cpu(extent->ee_block) == start)
5264                                 iterator = NULL;
5265                         else {
5266                                 extent = EXT_LAST_EXTENT(path[depth].p_hdr);
5267                                 while (le32_to_cpu(extent->ee_block) >= start)
5268                                         extent--;
5269
5270                                 if (extent == EXT_LAST_EXTENT(path[depth].p_hdr))
5271                                         break;
5272
5273                                 extent++;
5274                                 iterator = NULL;
5275                         }
5276                         path[depth].p_ext = extent;
5277                 }
5278                 ret = ext4_ext_shift_path_extents(path, shift, inode,
5279                                 handle, SHIFT);
5280                 /* iterator can be NULL which means we should break */
5281                 if (ret == -EAGAIN)
5282                         goto again;
5283                 if (ret)
5284                         break;
5285         }
5286 out:
5287         ext4_free_ext_path(path);
5288         return ret;
5289 }
5290
5291 /*
5292  * ext4_collapse_range:
5293  * This implements the fallocate's collapse range functionality for ext4
5294  * Returns: 0 and non-zero on error.
5295  */
5296 static int ext4_collapse_range(struct file *file, loff_t offset, loff_t len)
5297 {
5298         struct inode *inode = file_inode(file);
5299         struct super_block *sb = inode->i_sb;
5300         struct address_space *mapping = inode->i_mapping;
5301         ext4_lblk_t punch_start, punch_stop;
5302         handle_t *handle;
5303         unsigned int credits;
5304         loff_t new_size, ioffset;
5305         int ret;
5306
5307         /*
5308          * We need to test this early because xfstests assumes that a
5309          * collapse range of (0, 1) will return EOPNOTSUPP if the file
5310          * system does not support collapse range.
5311          */
5312         if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
5313                 return -EOPNOTSUPP;
5314
5315         /* Collapse range works only on fs cluster size aligned regions. */
5316         if (!IS_ALIGNED(offset | len, EXT4_CLUSTER_SIZE(sb)))
5317                 return -EINVAL;
5318
5319         trace_ext4_collapse_range(inode, offset, len);
5320
5321         punch_start = offset >> EXT4_BLOCK_SIZE_BITS(sb);
5322         punch_stop = (offset + len) >> EXT4_BLOCK_SIZE_BITS(sb);
5323
5324         inode_lock(inode);
5325         /*
5326          * There is no need to overlap collapse range with EOF, in which case
5327          * it is effectively a truncate operation
5328          */
5329         if (offset + len >= inode->i_size) {
5330                 ret = -EINVAL;
5331                 goto out_mutex;
5332         }
5333
5334         /* Currently just for extent based files */
5335         if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
5336                 ret = -EOPNOTSUPP;
5337                 goto out_mutex;
5338         }
5339
5340         /* Wait for existing dio to complete */
5341         inode_dio_wait(inode);
5342
5343         ret = file_modified(file);
5344         if (ret)
5345                 goto out_mutex;
5346
5347         /*
5348          * Prevent page faults from reinstantiating pages we have released from
5349          * page cache.
5350          */
5351         filemap_invalidate_lock(mapping);
5352
5353         ret = ext4_break_layouts(inode);
5354         if (ret)
5355                 goto out_mmap;
5356
5357         /*
5358          * Need to round down offset to be aligned with page size boundary
5359          * for page size > block size.
5360          */
5361         ioffset = round_down(offset, PAGE_SIZE);
5362         /*
5363          * Write tail of the last page before removed range since it will get
5364          * removed from the page cache below.
5365          */
5366         ret = filemap_write_and_wait_range(mapping, ioffset, offset);
5367         if (ret)
5368                 goto out_mmap;
5369         /*
5370          * Write data that will be shifted to preserve them when discarding
5371          * page cache below. We are also protected from pages becoming dirty
5372          * by i_rwsem and invalidate_lock.
5373          */
5374         ret = filemap_write_and_wait_range(mapping, offset + len,
5375                                            LLONG_MAX);
5376         if (ret)
5377                 goto out_mmap;
5378         truncate_pagecache(inode, ioffset);
5379
5380         credits = ext4_writepage_trans_blocks(inode);
5381         handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits);
5382         if (IS_ERR(handle)) {
5383                 ret = PTR_ERR(handle);
5384                 goto out_mmap;
5385         }
5386         ext4_fc_mark_ineligible(sb, EXT4_FC_REASON_FALLOC_RANGE, handle);
5387
5388         down_write(&EXT4_I(inode)->i_data_sem);
5389         ext4_discard_preallocations(inode, 0);
5390         ext4_es_remove_extent(inode, punch_start, EXT_MAX_BLOCKS - punch_start);
5391
5392         ret = ext4_ext_remove_space(inode, punch_start, punch_stop - 1);
5393         if (ret) {
5394                 up_write(&EXT4_I(inode)->i_data_sem);
5395                 goto out_stop;
5396         }
5397         ext4_discard_preallocations(inode, 0);
5398
5399         ret = ext4_ext_shift_extents(inode, handle, punch_stop,
5400                                      punch_stop - punch_start, SHIFT_LEFT);
5401         if (ret) {
5402                 up_write(&EXT4_I(inode)->i_data_sem);
5403                 goto out_stop;
5404         }
5405
5406         new_size = inode->i_size - len;
5407         i_size_write(inode, new_size);
5408         EXT4_I(inode)->i_disksize = new_size;
5409
5410         up_write(&EXT4_I(inode)->i_data_sem);
5411         if (IS_SYNC(inode))
5412                 ext4_handle_sync(handle);
5413         inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
5414         ret = ext4_mark_inode_dirty(handle, inode);
5415         ext4_update_inode_fsync_trans(handle, inode, 1);
5416
5417 out_stop:
5418         ext4_journal_stop(handle);
5419 out_mmap:
5420         filemap_invalidate_unlock(mapping);
5421 out_mutex:
5422         inode_unlock(inode);
5423         return ret;
5424 }
5425
5426 /*
5427  * ext4_insert_range:
5428  * This function implements the FALLOC_FL_INSERT_RANGE flag of fallocate.
5429  * The data blocks starting from @offset to the EOF are shifted by @len
5430  * towards right to create a hole in the @inode. Inode size is increased
5431  * by len bytes.
5432  * Returns 0 on success, error otherwise.
5433  */
5434 static int ext4_insert_range(struct file *file, loff_t offset, loff_t len)
5435 {
5436         struct inode *inode = file_inode(file);
5437         struct super_block *sb = inode->i_sb;
5438         struct address_space *mapping = inode->i_mapping;
5439         handle_t *handle;
5440         struct ext4_ext_path *path;
5441         struct ext4_extent *extent;
5442         ext4_lblk_t offset_lblk, len_lblk, ee_start_lblk = 0;
5443         unsigned int credits, ee_len;
5444         int ret = 0, depth, split_flag = 0;
5445         loff_t ioffset;
5446
5447         /*
5448          * We need to test this early because xfstests assumes that an
5449          * insert range of (0, 1) will return EOPNOTSUPP if the file
5450          * system does not support insert range.
5451          */
5452         if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
5453                 return -EOPNOTSUPP;
5454
5455         /* Insert range works only on fs cluster size aligned regions. */
5456         if (!IS_ALIGNED(offset | len, EXT4_CLUSTER_SIZE(sb)))
5457                 return -EINVAL;
5458
5459         trace_ext4_insert_range(inode, offset, len);
5460
5461         offset_lblk = offset >> EXT4_BLOCK_SIZE_BITS(sb);
5462         len_lblk = len >> EXT4_BLOCK_SIZE_BITS(sb);
5463
5464         inode_lock(inode);
5465         /* Currently just for extent based files */
5466         if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
5467                 ret = -EOPNOTSUPP;
5468                 goto out_mutex;
5469         }
5470
5471         /* Check whether the maximum file size would be exceeded */
5472         if (len > inode->i_sb->s_maxbytes - inode->i_size) {
5473                 ret = -EFBIG;
5474                 goto out_mutex;
5475         }
5476
5477         /* Offset must be less than i_size */
5478         if (offset >= inode->i_size) {
5479                 ret = -EINVAL;
5480                 goto out_mutex;
5481         }
5482
5483         /* Wait for existing dio to complete */
5484         inode_dio_wait(inode);
5485
5486         ret = file_modified(file);
5487         if (ret)
5488                 goto out_mutex;
5489
5490         /*
5491          * Prevent page faults from reinstantiating pages we have released from
5492          * page cache.
5493          */
5494         filemap_invalidate_lock(mapping);
5495
5496         ret = ext4_break_layouts(inode);
5497         if (ret)
5498                 goto out_mmap;
5499
5500         /*
5501          * Need to round down to align start offset to page size boundary
5502          * for page size > block size.
5503          */
5504         ioffset = round_down(offset, PAGE_SIZE);
5505         /* Write out all dirty pages */
5506         ret = filemap_write_and_wait_range(inode->i_mapping, ioffset,
5507                         LLONG_MAX);
5508         if (ret)
5509                 goto out_mmap;
5510         truncate_pagecache(inode, ioffset);
5511
5512         credits = ext4_writepage_trans_blocks(inode);
5513         handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits);
5514         if (IS_ERR(handle)) {
5515                 ret = PTR_ERR(handle);
5516                 goto out_mmap;
5517         }
5518         ext4_fc_mark_ineligible(sb, EXT4_FC_REASON_FALLOC_RANGE, handle);
5519
5520         /* Expand file to avoid data loss if there is error while shifting */
5521         inode->i_size += len;
5522         EXT4_I(inode)->i_disksize += len;
5523         inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
5524         ret = ext4_mark_inode_dirty(handle, inode);
5525         if (ret)
5526                 goto out_stop;
5527
5528         down_write(&EXT4_I(inode)->i_data_sem);
5529         ext4_discard_preallocations(inode, 0);
5530
5531         path = ext4_find_extent(inode, offset_lblk, NULL, 0);
5532         if (IS_ERR(path)) {
5533                 up_write(&EXT4_I(inode)->i_data_sem);
5534                 goto out_stop;
5535         }
5536
5537         depth = ext_depth(inode);
5538         extent = path[depth].p_ext;
5539         if (extent) {
5540                 ee_start_lblk = le32_to_cpu(extent->ee_block);
5541                 ee_len = ext4_ext_get_actual_len(extent);
5542
5543                 /*
5544                  * If offset_lblk is not the starting block of extent, split
5545                  * the extent @offset_lblk
5546                  */
5547                 if ((offset_lblk > ee_start_lblk) &&
5548                                 (offset_lblk < (ee_start_lblk + ee_len))) {
5549                         if (ext4_ext_is_unwritten(extent))
5550                                 split_flag = EXT4_EXT_MARK_UNWRIT1 |
5551                                         EXT4_EXT_MARK_UNWRIT2;
5552                         ret = ext4_split_extent_at(handle, inode, &path,
5553                                         offset_lblk, split_flag,
5554                                         EXT4_EX_NOCACHE |
5555                                         EXT4_GET_BLOCKS_PRE_IO |
5556                                         EXT4_GET_BLOCKS_METADATA_NOFAIL);
5557                 }
5558
5559                 ext4_free_ext_path(path);
5560                 if (ret < 0) {
5561                         up_write(&EXT4_I(inode)->i_data_sem);
5562                         goto out_stop;
5563                 }
5564         } else {
5565                 ext4_free_ext_path(path);
5566         }
5567
5568         ext4_es_remove_extent(inode, offset_lblk, EXT_MAX_BLOCKS - offset_lblk);
5569
5570         /*
5571          * if offset_lblk lies in a hole which is at start of file, use
5572          * ee_start_lblk to shift extents
5573          */
5574         ret = ext4_ext_shift_extents(inode, handle,
5575                 max(ee_start_lblk, offset_lblk), len_lblk, SHIFT_RIGHT);
5576
5577         up_write(&EXT4_I(inode)->i_data_sem);
5578         if (IS_SYNC(inode))
5579                 ext4_handle_sync(handle);
5580         if (ret >= 0)
5581                 ext4_update_inode_fsync_trans(handle, inode, 1);
5582
5583 out_stop:
5584         ext4_journal_stop(handle);
5585 out_mmap:
5586         filemap_invalidate_unlock(mapping);
5587 out_mutex:
5588         inode_unlock(inode);
5589         return ret;
5590 }
5591
5592 /**
5593  * ext4_swap_extents() - Swap extents between two inodes
5594  * @handle: handle for this transaction
5595  * @inode1:     First inode
5596  * @inode2:     Second inode
5597  * @lblk1:      Start block for first inode
5598  * @lblk2:      Start block for second inode
5599  * @count:      Number of blocks to swap
5600  * @unwritten: Mark second inode's extents as unwritten after swap
5601  * @erp:        Pointer to save error value
5602  *
5603  * This helper routine does exactly what is promise "swap extents". All other
5604  * stuff such as page-cache locking consistency, bh mapping consistency or
5605  * extent's data copying must be performed by caller.
5606  * Locking:
5607  *              i_rwsem is held for both inodes
5608  *              i_data_sem is locked for write for both inodes
5609  * Assumptions:
5610  *              All pages from requested range are locked for both inodes
5611  */
5612 int
5613 ext4_swap_extents(handle_t *handle, struct inode *inode1,
5614                   struct inode *inode2, ext4_lblk_t lblk1, ext4_lblk_t lblk2,
5615                   ext4_lblk_t count, int unwritten, int *erp)
5616 {
5617         struct ext4_ext_path *path1 = NULL;
5618         struct ext4_ext_path *path2 = NULL;
5619         int replaced_count = 0;
5620
5621         BUG_ON(!rwsem_is_locked(&EXT4_I(inode1)->i_data_sem));
5622         BUG_ON(!rwsem_is_locked(&EXT4_I(inode2)->i_data_sem));
5623         BUG_ON(!inode_is_locked(inode1));
5624         BUG_ON(!inode_is_locked(inode2));
5625
5626         ext4_es_remove_extent(inode1, lblk1, count);
5627         ext4_es_remove_extent(inode2, lblk2, count);
5628
5629         while (count) {
5630                 struct ext4_extent *ex1, *ex2, tmp_ex;
5631                 ext4_lblk_t e1_blk, e2_blk;
5632                 int e1_len, e2_len, len;
5633                 int split = 0;
5634
5635                 path1 = ext4_find_extent(inode1, lblk1, NULL, EXT4_EX_NOCACHE);
5636                 if (IS_ERR(path1)) {
5637                         *erp = PTR_ERR(path1);
5638                         path1 = NULL;
5639                 finish:
5640                         count = 0;
5641                         goto repeat;
5642                 }
5643                 path2 = ext4_find_extent(inode2, lblk2, NULL, EXT4_EX_NOCACHE);
5644                 if (IS_ERR(path2)) {
5645                         *erp = PTR_ERR(path2);
5646                         path2 = NULL;
5647                         goto finish;
5648                 }
5649                 ex1 = path1[path1->p_depth].p_ext;
5650                 ex2 = path2[path2->p_depth].p_ext;
5651                 /* Do we have something to swap ? */
5652                 if (unlikely(!ex2 || !ex1))
5653                         goto finish;
5654
5655                 e1_blk = le32_to_cpu(ex1->ee_block);
5656                 e2_blk = le32_to_cpu(ex2->ee_block);
5657                 e1_len = ext4_ext_get_actual_len(ex1);
5658                 e2_len = ext4_ext_get_actual_len(ex2);
5659
5660                 /* Hole handling */
5661                 if (!in_range(lblk1, e1_blk, e1_len) ||
5662                     !in_range(lblk2, e2_blk, e2_len)) {
5663                         ext4_lblk_t next1, next2;
5664
5665                         /* if hole after extent, then go to next extent */
5666                         next1 = ext4_ext_next_allocated_block(path1);
5667                         next2 = ext4_ext_next_allocated_block(path2);
5668                         /* If hole before extent, then shift to that extent */
5669                         if (e1_blk > lblk1)
5670                                 next1 = e1_blk;
5671                         if (e2_blk > lblk2)
5672                                 next2 = e2_blk;
5673                         /* Do we have something to swap */
5674                         if (next1 == EXT_MAX_BLOCKS || next2 == EXT_MAX_BLOCKS)
5675                                 goto finish;
5676                         /* Move to the rightest boundary */
5677                         len = next1 - lblk1;
5678                         if (len < next2 - lblk2)
5679                                 len = next2 - lblk2;
5680                         if (len > count)
5681                                 len = count;
5682                         lblk1 += len;
5683                         lblk2 += len;
5684                         count -= len;
5685                         goto repeat;
5686                 }
5687
5688                 /* Prepare left boundary */
5689                 if (e1_blk < lblk1) {
5690                         split = 1;
5691                         *erp = ext4_force_split_extent_at(handle, inode1,
5692                                                 &path1, lblk1, 0);
5693                         if (unlikely(*erp))
5694                                 goto finish;
5695                 }
5696                 if (e2_blk < lblk2) {
5697                         split = 1;
5698                         *erp = ext4_force_split_extent_at(handle, inode2,
5699                                                 &path2,  lblk2, 0);
5700                         if (unlikely(*erp))
5701                                 goto finish;
5702                 }
5703                 /* ext4_split_extent_at() may result in leaf extent split,
5704                  * path must to be revalidated. */
5705                 if (split)
5706                         goto repeat;
5707
5708                 /* Prepare right boundary */
5709                 len = count;
5710                 if (len > e1_blk + e1_len - lblk1)
5711                         len = e1_blk + e1_len - lblk1;
5712                 if (len > e2_blk + e2_len - lblk2)
5713                         len = e2_blk + e2_len - lblk2;
5714
5715                 if (len != e1_len) {
5716                         split = 1;
5717                         *erp = ext4_force_split_extent_at(handle, inode1,
5718                                                 &path1, lblk1 + len, 0);
5719                         if (unlikely(*erp))
5720                                 goto finish;
5721                 }
5722                 if (len != e2_len) {
5723                         split = 1;
5724                         *erp = ext4_force_split_extent_at(handle, inode2,
5725                                                 &path2, lblk2 + len, 0);
5726                         if (*erp)
5727                                 goto finish;
5728                 }
5729                 /* ext4_split_extent_at() may result in leaf extent split,
5730                  * path must to be revalidated. */
5731                 if (split)
5732                         goto repeat;
5733
5734                 BUG_ON(e2_len != e1_len);
5735                 *erp = ext4_ext_get_access(handle, inode1, path1 + path1->p_depth);
5736                 if (unlikely(*erp))
5737                         goto finish;
5738                 *erp = ext4_ext_get_access(handle, inode2, path2 + path2->p_depth);
5739                 if (unlikely(*erp))
5740                         goto finish;
5741
5742                 /* Both extents are fully inside boundaries. Swap it now */
5743                 tmp_ex = *ex1;
5744                 ext4_ext_store_pblock(ex1, ext4_ext_pblock(ex2));
5745                 ext4_ext_store_pblock(ex2, ext4_ext_pblock(&tmp_ex));
5746                 ex1->ee_len = cpu_to_le16(e2_len);
5747                 ex2->ee_len = cpu_to_le16(e1_len);
5748                 if (unwritten)
5749                         ext4_ext_mark_unwritten(ex2);
5750                 if (ext4_ext_is_unwritten(&tmp_ex))
5751                         ext4_ext_mark_unwritten(ex1);
5752
5753                 ext4_ext_try_to_merge(handle, inode2, path2, ex2);
5754                 ext4_ext_try_to_merge(handle, inode1, path1, ex1);
5755                 *erp = ext4_ext_dirty(handle, inode2, path2 +
5756                                       path2->p_depth);
5757                 if (unlikely(*erp))
5758                         goto finish;
5759                 *erp = ext4_ext_dirty(handle, inode1, path1 +
5760                                       path1->p_depth);
5761                 /*
5762                  * Looks scarry ah..? second inode already points to new blocks,
5763                  * and it was successfully dirtied. But luckily error may happen
5764                  * only due to journal error, so full transaction will be
5765                  * aborted anyway.
5766                  */
5767                 if (unlikely(*erp))
5768                         goto finish;
5769                 lblk1 += len;
5770                 lblk2 += len;
5771                 replaced_count += len;
5772                 count -= len;
5773
5774         repeat:
5775                 ext4_free_ext_path(path1);
5776                 ext4_free_ext_path(path2);
5777                 path1 = path2 = NULL;
5778         }
5779         return replaced_count;
5780 }
5781
5782 /*
5783  * ext4_clu_mapped - determine whether any block in a logical cluster has
5784  *                   been mapped to a physical cluster
5785  *
5786  * @inode - file containing the logical cluster
5787  * @lclu - logical cluster of interest
5788  *
5789  * Returns 1 if any block in the logical cluster is mapped, signifying
5790  * that a physical cluster has been allocated for it.  Otherwise,
5791  * returns 0.  Can also return negative error codes.  Derived from
5792  * ext4_ext_map_blocks().
5793  */
5794 int ext4_clu_mapped(struct inode *inode, ext4_lblk_t lclu)
5795 {
5796         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
5797         struct ext4_ext_path *path;
5798         int depth, mapped = 0, err = 0;
5799         struct ext4_extent *extent;
5800         ext4_lblk_t first_lblk, first_lclu, last_lclu;
5801
5802         /*
5803          * if data can be stored inline, the logical cluster isn't
5804          * mapped - no physical clusters have been allocated, and the
5805          * file has no extents
5806          */
5807         if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA) ||
5808             ext4_has_inline_data(inode))
5809                 return 0;
5810
5811         /* search for the extent closest to the first block in the cluster */
5812         path = ext4_find_extent(inode, EXT4_C2B(sbi, lclu), NULL, 0);
5813         if (IS_ERR(path)) {
5814                 err = PTR_ERR(path);
5815                 path = NULL;
5816                 goto out;
5817         }
5818
5819         depth = ext_depth(inode);
5820
5821         /*
5822          * A consistent leaf must not be empty.  This situation is possible,
5823          * though, _during_ tree modification, and it's why an assert can't
5824          * be put in ext4_find_extent().
5825          */
5826         if (unlikely(path[depth].p_ext == NULL && depth != 0)) {
5827                 EXT4_ERROR_INODE(inode,
5828                     "bad extent address - lblock: %lu, depth: %d, pblock: %lld",
5829                                  (unsigned long) EXT4_C2B(sbi, lclu),
5830                                  depth, path[depth].p_block);
5831                 err = -EFSCORRUPTED;
5832                 goto out;
5833         }
5834
5835         extent = path[depth].p_ext;
5836
5837         /* can't be mapped if the extent tree is empty */
5838         if (extent == NULL)
5839                 goto out;
5840
5841         first_lblk = le32_to_cpu(extent->ee_block);
5842         first_lclu = EXT4_B2C(sbi, first_lblk);
5843
5844         /*
5845          * Three possible outcomes at this point - found extent spanning
5846          * the target cluster, to the left of the target cluster, or to the
5847          * right of the target cluster.  The first two cases are handled here.
5848          * The last case indicates the target cluster is not mapped.
5849          */
5850         if (lclu >= first_lclu) {
5851                 last_lclu = EXT4_B2C(sbi, first_lblk +
5852                                      ext4_ext_get_actual_len(extent) - 1);
5853                 if (lclu <= last_lclu) {
5854                         mapped = 1;
5855                 } else {
5856                         first_lblk = ext4_ext_next_allocated_block(path);
5857                         first_lclu = EXT4_B2C(sbi, first_lblk);
5858                         if (lclu == first_lclu)
5859                                 mapped = 1;
5860                 }
5861         }
5862
5863 out:
5864         ext4_free_ext_path(path);
5865
5866         return err ? err : mapped;
5867 }
5868
5869 /*
5870  * Updates physical block address and unwritten status of extent
5871  * starting at lblk start and of len. If such an extent doesn't exist,
5872  * this function splits the extent tree appropriately to create an
5873  * extent like this.  This function is called in the fast commit
5874  * replay path.  Returns 0 on success and error on failure.
5875  */
5876 int ext4_ext_replay_update_ex(struct inode *inode, ext4_lblk_t start,
5877                               int len, int unwritten, ext4_fsblk_t pblk)
5878 {
5879         struct ext4_ext_path *path = NULL, *ppath;
5880         struct ext4_extent *ex;
5881         int ret;
5882
5883         path = ext4_find_extent(inode, start, NULL, 0);
5884         if (IS_ERR(path))
5885                 return PTR_ERR(path);
5886         ex = path[path->p_depth].p_ext;
5887         if (!ex) {
5888                 ret = -EFSCORRUPTED;
5889                 goto out;
5890         }
5891
5892         if (le32_to_cpu(ex->ee_block) != start ||
5893                 ext4_ext_get_actual_len(ex) != len) {
5894                 /* We need to split this extent to match our extent first */
5895                 ppath = path;
5896                 down_write(&EXT4_I(inode)->i_data_sem);
5897                 ret = ext4_force_split_extent_at(NULL, inode, &ppath, start, 1);
5898                 up_write(&EXT4_I(inode)->i_data_sem);
5899                 if (ret)
5900                         goto out;
5901                 kfree(path);
5902                 path = ext4_find_extent(inode, start, NULL, 0);
5903                 if (IS_ERR(path))
5904                         return -1;
5905                 ppath = path;
5906                 ex = path[path->p_depth].p_ext;
5907                 WARN_ON(le32_to_cpu(ex->ee_block) != start);
5908                 if (ext4_ext_get_actual_len(ex) != len) {
5909                         down_write(&EXT4_I(inode)->i_data_sem);
5910                         ret = ext4_force_split_extent_at(NULL, inode, &ppath,
5911                                                          start + len, 1);
5912                         up_write(&EXT4_I(inode)->i_data_sem);
5913                         if (ret)
5914                                 goto out;
5915                         kfree(path);
5916                         path = ext4_find_extent(inode, start, NULL, 0);
5917                         if (IS_ERR(path))
5918                                 return -EINVAL;
5919                         ex = path[path->p_depth].p_ext;
5920                 }
5921         }
5922         if (unwritten)
5923                 ext4_ext_mark_unwritten(ex);
5924         else
5925                 ext4_ext_mark_initialized(ex);
5926         ext4_ext_store_pblock(ex, pblk);
5927         down_write(&EXT4_I(inode)->i_data_sem);
5928         ret = ext4_ext_dirty(NULL, inode, &path[path->p_depth]);
5929         up_write(&EXT4_I(inode)->i_data_sem);
5930 out:
5931         ext4_free_ext_path(path);
5932         ext4_mark_inode_dirty(NULL, inode);
5933         return ret;
5934 }
5935
5936 /* Try to shrink the extent tree */
5937 void ext4_ext_replay_shrink_inode(struct inode *inode, ext4_lblk_t end)
5938 {
5939         struct ext4_ext_path *path = NULL;
5940         struct ext4_extent *ex;
5941         ext4_lblk_t old_cur, cur = 0;
5942
5943         while (cur < end) {
5944                 path = ext4_find_extent(inode, cur, NULL, 0);
5945                 if (IS_ERR(path))
5946                         return;
5947                 ex = path[path->p_depth].p_ext;
5948                 if (!ex) {
5949                         ext4_free_ext_path(path);
5950                         ext4_mark_inode_dirty(NULL, inode);
5951                         return;
5952                 }
5953                 old_cur = cur;
5954                 cur = le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex);
5955                 if (cur <= old_cur)
5956                         cur = old_cur + 1;
5957                 ext4_ext_try_to_merge(NULL, inode, path, ex);
5958                 down_write(&EXT4_I(inode)->i_data_sem);
5959                 ext4_ext_dirty(NULL, inode, &path[path->p_depth]);
5960                 up_write(&EXT4_I(inode)->i_data_sem);
5961                 ext4_mark_inode_dirty(NULL, inode);
5962                 ext4_free_ext_path(path);
5963         }
5964 }
5965
5966 /* Check if *cur is a hole and if it is, skip it */
5967 static int skip_hole(struct inode *inode, ext4_lblk_t *cur)
5968 {
5969         int ret;
5970         struct ext4_map_blocks map;
5971
5972         map.m_lblk = *cur;
5973         map.m_len = ((inode->i_size) >> inode->i_sb->s_blocksize_bits) - *cur;
5974
5975         ret = ext4_map_blocks(NULL, inode, &map, 0);
5976         if (ret < 0)
5977                 return ret;
5978         if (ret != 0)
5979                 return 0;
5980         *cur = *cur + map.m_len;
5981         return 0;
5982 }
5983
5984 /* Count number of blocks used by this inode and update i_blocks */
5985 int ext4_ext_replay_set_iblocks(struct inode *inode)
5986 {
5987         struct ext4_ext_path *path = NULL, *path2 = NULL;
5988         struct ext4_extent *ex;
5989         ext4_lblk_t cur = 0, end;
5990         int numblks = 0, i, ret = 0;
5991         ext4_fsblk_t cmp1, cmp2;
5992         struct ext4_map_blocks map;
5993
5994         /* Determin the size of the file first */
5995         path = ext4_find_extent(inode, EXT_MAX_BLOCKS - 1, NULL,
5996                                         EXT4_EX_NOCACHE);
5997         if (IS_ERR(path))
5998                 return PTR_ERR(path);
5999         ex = path[path->p_depth].p_ext;
6000         if (!ex) {
6001                 ext4_free_ext_path(path);
6002                 goto out;
6003         }
6004         end = le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex);
6005         ext4_free_ext_path(path);
6006
6007         /* Count the number of data blocks */
6008         cur = 0;
6009         while (cur < end) {
6010                 map.m_lblk = cur;
6011                 map.m_len = end - cur;
6012                 ret = ext4_map_blocks(NULL, inode, &map, 0);
6013                 if (ret < 0)
6014                         break;
6015                 if (ret > 0)
6016                         numblks += ret;
6017                 cur = cur + map.m_len;
6018         }
6019
6020         /*
6021          * Count the number of extent tree blocks. We do it by looking up
6022          * two successive extents and determining the difference between
6023          * their paths. When path is different for 2 successive extents
6024          * we compare the blocks in the path at each level and increment
6025          * iblocks by total number of differences found.
6026          */
6027         cur = 0;
6028         ret = skip_hole(inode, &cur);
6029         if (ret < 0)
6030                 goto out;
6031         path = ext4_find_extent(inode, cur, NULL, 0);
6032         if (IS_ERR(path))
6033                 goto out;
6034         numblks += path->p_depth;
6035         ext4_free_ext_path(path);
6036         while (cur < end) {
6037                 path = ext4_find_extent(inode, cur, NULL, 0);
6038                 if (IS_ERR(path))
6039                         break;
6040                 ex = path[path->p_depth].p_ext;
6041                 if (!ex) {
6042                         ext4_free_ext_path(path);
6043                         return 0;
6044                 }
6045                 cur = max(cur + 1, le32_to_cpu(ex->ee_block) +
6046                                         ext4_ext_get_actual_len(ex));
6047                 ret = skip_hole(inode, &cur);
6048                 if (ret < 0) {
6049                         ext4_free_ext_path(path);
6050                         break;
6051                 }
6052                 path2 = ext4_find_extent(inode, cur, NULL, 0);
6053                 if (IS_ERR(path2)) {
6054                         ext4_free_ext_path(path);
6055                         break;
6056                 }
6057                 for (i = 0; i <= max(path->p_depth, path2->p_depth); i++) {
6058                         cmp1 = cmp2 = 0;
6059                         if (i <= path->p_depth)
6060                                 cmp1 = path[i].p_bh ?
6061                                         path[i].p_bh->b_blocknr : 0;
6062                         if (i <= path2->p_depth)
6063                                 cmp2 = path2[i].p_bh ?
6064                                         path2[i].p_bh->b_blocknr : 0;
6065                         if (cmp1 != cmp2 && cmp2 != 0)
6066                                 numblks++;
6067                 }
6068                 ext4_free_ext_path(path);
6069                 ext4_free_ext_path(path2);
6070         }
6071
6072 out:
6073         inode->i_blocks = numblks << (inode->i_sb->s_blocksize_bits - 9);
6074         ext4_mark_inode_dirty(NULL, inode);
6075         return 0;
6076 }
6077
6078 int ext4_ext_clear_bb(struct inode *inode)
6079 {
6080         struct ext4_ext_path *path = NULL;
6081         struct ext4_extent *ex;
6082         ext4_lblk_t cur = 0, end;
6083         int j, ret = 0;
6084         struct ext4_map_blocks map;
6085
6086         if (ext4_test_inode_flag(inode, EXT4_INODE_INLINE_DATA))
6087                 return 0;
6088
6089         /* Determin the size of the file first */
6090         path = ext4_find_extent(inode, EXT_MAX_BLOCKS - 1, NULL,
6091                                         EXT4_EX_NOCACHE);
6092         if (IS_ERR(path))
6093                 return PTR_ERR(path);
6094         ex = path[path->p_depth].p_ext;
6095         if (!ex) {
6096                 ext4_free_ext_path(path);
6097                 return 0;
6098         }
6099         end = le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex);
6100         ext4_free_ext_path(path);
6101
6102         cur = 0;
6103         while (cur < end) {
6104                 map.m_lblk = cur;
6105                 map.m_len = end - cur;
6106                 ret = ext4_map_blocks(NULL, inode, &map, 0);
6107                 if (ret < 0)
6108                         break;
6109                 if (ret > 0) {
6110                         path = ext4_find_extent(inode, map.m_lblk, NULL, 0);
6111                         if (!IS_ERR_OR_NULL(path)) {
6112                                 for (j = 0; j < path->p_depth; j++) {
6113
6114                                         ext4_mb_mark_bb(inode->i_sb,
6115                                                         path[j].p_block, 1, false);
6116                                         ext4_fc_record_regions(inode->i_sb, inode->i_ino,
6117                                                         0, path[j].p_block, 1, 1);
6118                                 }
6119                                 ext4_free_ext_path(path);
6120                         }
6121                         ext4_mb_mark_bb(inode->i_sb, map.m_pblk, map.m_len, false);
6122                         ext4_fc_record_regions(inode->i_sb, inode->i_ino,
6123                                         map.m_lblk, map.m_pblk, map.m_len, 1);
6124                 }
6125                 cur = cur + map.m_len;
6126         }
6127
6128         return 0;
6129 }