fs/nilfs2/inode.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * inode.c - NILFS inode operations.
   4  *
   5  * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
   6  *
   7  * Written by Ryusuke Konishi.
   8  *
   9  */
  10
  11 #include <linux/buffer_head.h>
  12 #include <linux/gfp.h>
  13 #include <linux/mpage.h>
  14 #include <linux/pagemap.h>
  15 #include <linux/writeback.h>
  16 #include <linux/uio.h>
  17 #include <linux/fiemap.h>
  18 #include "nilfs.h"
  19 #include "btnode.h"
  20 #include "segment.h"
  21 #include "page.h"
  22 #include "mdt.h"
  23 #include "cpfile.h"
  24 #include "ifile.h"
  25
  26 /**
  27  * struct nilfs_iget_args - arguments used during comparison between inodes
  28  * @ino: inode number
  29  * @cno: checkpoint number
  30  * @root: pointer on NILFS root object (mounted checkpoint)
  31  * @for_gc: inode for GC flag
  32  * @for_btnc: inode for B-tree node cache flag
  33  * @for_shadow: inode for shadowed page cache flag
  34  */
  35 struct nilfs_iget_args {
  36         u64 ino;
  37         __u64 cno;
  38         struct nilfs_root *root;
  39         bool for_gc;
  40         bool for_btnc;
  41         bool for_shadow;
  42 };
  43
  44 static int nilfs_iget_test(struct inode *inode, void *opaque);
  45
  46 void nilfs_inode_add_blocks(struct inode *inode, int n)
  47 {
  48         struct nilfs_root *root = NILFS_I(inode)->i_root;
  49
  50         inode_add_bytes(inode, i_blocksize(inode) * n);
  51         if (root)
  52                 atomic64_add(n, &root->blocks_count);
  53 }
  54
  55 void nilfs_inode_sub_blocks(struct inode *inode, int n)
  56 {
  57         struct nilfs_root *root = NILFS_I(inode)->i_root;
  58
  59         inode_sub_bytes(inode, i_blocksize(inode) * n);
  60         if (root)
  61                 atomic64_sub(n, &root->blocks_count);
  62 }
  63
  64 /**
  65  * nilfs_get_block() - get a file block on the filesystem (callback function)
  66  * @inode - inode struct of the target file
  67  * @blkoff - file block number
  68  * @bh_result - buffer head to be mapped on
  69  * @create - indicate whether allocating the block or not when it has not
  70  *      been allocated yet.
  71  *
  72  * This function does not issue actual read request of the specified data
  73  * block. It is done by VFS.
  74  */
  75 int nilfs_get_block(struct inode *inode, sector_t blkoff,
  76                     struct buffer_head *bh_result, int create)
  77 {
  78         struct nilfs_inode_info *ii = NILFS_I(inode);
  79         struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
  80         __u64 blknum = 0;
  81         int err = 0, ret;
  82         unsigned int maxblocks = bh_result->b_size >> inode->i_blkbits;
  83
  84         down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
  85         ret = nilfs_bmap_lookup_contig(ii->i_bmap, blkoff, &blknum, maxblocks);
  86         up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
  87         if (ret >= 0) { /* found */
  88                 map_bh(bh_result, inode->i_sb, blknum);
  89                 if (ret > 0)
  90                         bh_result->b_size = (ret << inode->i_blkbits);
  91                 goto out;
  92         }
  93         /* data block was not found */
  94         if (ret == -ENOENT && create) {
  95                 struct nilfs_transaction_info ti;
  96
  97                 bh_result->b_blocknr = 0;
  98                 err = nilfs_transaction_begin(inode->i_sb, &ti, 1);
  99                 if (unlikely(err))
 100                         goto out;
 101                 err = nilfs_bmap_insert(ii->i_bmap, blkoff,
 102                                         (unsigned long)bh_result);
 103                 if (unlikely(err != 0)) {
 104                         if (err == -EEXIST) {
 105                                 /*
 106                                  * The get_block() function could be called
 107                                  * from multiple callers for an inode.
 108                                  * However, the page having this block must
 109                                  * be locked in this case.
 110                                  */
 111                                 nilfs_warn(inode->i_sb,
 112                                            "%s (ino=%lu): a race condition while inserting a data block at offset=%llu",
 113                                            __func__, inode->i_ino,
 114                                            (unsigned long long)blkoff);
 115                                 err = 0;
 116                         }
 117                         nilfs_transaction_abort(inode->i_sb);
 118                         goto out;
 119                 }
 120                 nilfs_mark_inode_dirty_sync(inode);
 121                 nilfs_transaction_commit(inode->i_sb); /* never fails */
 122                 /* Error handling should be detailed */
 123                 set_buffer_new(bh_result);
 124                 set_buffer_delay(bh_result);
 125                 map_bh(bh_result, inode->i_sb, 0);
 126                 /* Disk block number must be changed to proper value */
 127
 128         } else if (ret == -ENOENT) {
 129                 /*
 130                  * not found is not error (e.g. hole); must return without
 131                  * the mapped state flag.
 132                  */
 133                 ;
 134         } else {
 135                 err = ret;
 136         }
 137
 138  out:
 139         return err;
 140 }
 141
 142 /**
 143  * nilfs_readpage() - implement readpage() method of nilfs_aops {}
 144  * address_space_operations.
 145  * @file - file struct of the file to be read
 146  * @page - the page to be read
 147  */
 148 static int nilfs_readpage(struct file *file, struct page *page)
 149 {
 150         return mpage_readpage(page, nilfs_get_block);
 151 }
 152
 153 static void nilfs_readahead(struct readahead_control *rac)
 154 {
 155         mpage_readahead(rac, nilfs_get_block);
 156 }
 157
 158 static int nilfs_writepages(struct address_space *mapping,
 159                             struct writeback_control *wbc)
 160 {
 161         struct inode *inode = mapping->host;
 162         int err = 0;
 163
 164         if (sb_rdonly(inode->i_sb)) {
 165                 nilfs_clear_dirty_pages(mapping, false);
 166                 return -EROFS;
 167         }
 168
 169         if (wbc->sync_mode == WB_SYNC_ALL)
 170                 err = nilfs_construct_dsync_segment(inode->i_sb, inode,
 171                                                     wbc->range_start,
 172                                                     wbc->range_end);
 173         return err;
 174 }
 175
 176 static int nilfs_writepage(struct page *page, struct writeback_control *wbc)
 177 {
 178         struct inode *inode = page->mapping->host;
 179         int err;
 180
 181         if (sb_rdonly(inode->i_sb)) {
 182                 /*
 183                  * It means that filesystem was remounted in read-only
 184                  * mode because of error or metadata corruption. But we
 185                  * have dirty pages that try to be flushed in background.
 186                  * So, here we simply discard this dirty page.
 187                  */
 188                 nilfs_clear_dirty_page(page, false);
 189                 unlock_page(page);
 190                 return -EROFS;
 191         }
 192
 193         redirty_page_for_writepage(wbc, page);
 194         unlock_page(page);
 195
 196         if (wbc->sync_mode == WB_SYNC_ALL) {
 197                 err = nilfs_construct_segment(inode->i_sb);
 198                 if (unlikely(err))
 199                         return err;
 200         } else if (wbc->for_reclaim)
 201                 nilfs_flush_segment(inode->i_sb, inode->i_ino);
 202
 203         return 0;
 204 }
 205
 206 static int nilfs_set_page_dirty(struct page *page)
 207 {
 208         struct inode *inode = page->mapping->host;
 209         int ret = __set_page_dirty_nobuffers(page);
 210
 211         if (page_has_buffers(page)) {
 212                 unsigned int nr_dirty = 0;
 213                 struct buffer_head *bh, *head;
 214
 215                 /*
 216                  * This page is locked by callers, and no other thread
 217                  * concurrently marks its buffers dirty since they are
 218                  * only dirtied through routines in fs/buffer.c in
 219                  * which call sites of mark_buffer_dirty are protected
 220                  * by page lock.
 221                  */
 222                 bh = head = page_buffers(page);
 223                 do {
 224                         /* Do not mark hole blocks dirty */
 225                         if (buffer_dirty(bh) || !buffer_mapped(bh))
 226                                 continue;
 227
 228                         set_buffer_dirty(bh);
 229                         nr_dirty++;
 230                 } while (bh = bh->b_this_page, bh != head);
 231
 232                 if (nr_dirty)
 233                         nilfs_set_file_dirty(inode, nr_dirty);
 234         } else if (ret) {
 235                 unsigned int nr_dirty = 1 << (PAGE_SHIFT - inode->i_blkbits);
 236
 237                 nilfs_set_file_dirty(inode, nr_dirty);
 238         }
 239         return ret;
 240 }
 241
 242 void nilfs_write_failed(struct address_space *mapping, loff_t to)
 243 {
 244         struct inode *inode = mapping->host;
 245
 246         if (to > inode->i_size) {
 247                 truncate_pagecache(inode, inode->i_size);
 248                 nilfs_truncate(inode);
 249         }
 250 }
 251
 252 static int nilfs_write_begin(struct file *file, struct address_space *mapping,
 253                              loff_t pos, unsigned len, unsigned flags,
 254                              struct page **pagep, void **fsdata)
 255
 256 {
 257         struct inode *inode = mapping->host;
 258         int err = nilfs_transaction_begin(inode->i_sb, NULL, 1);
 259
 260         if (unlikely(err))
 261                 return err;
 262
 263         err = block_write_begin(mapping, pos, len, flags, pagep,
 264                                 nilfs_get_block);
 265         if (unlikely(err)) {
 266                 nilfs_write_failed(mapping, pos + len);
 267                 nilfs_transaction_abort(inode->i_sb);
 268         }
 269         return err;
 270 }
 271
 272 static int nilfs_write_end(struct file *file, struct address_space *mapping,
 273                            loff_t pos, unsigned len, unsigned copied,
 274                            struct page *page, void *fsdata)
 275 {
 276         struct inode *inode = mapping->host;
 277         unsigned int start = pos & (PAGE_SIZE - 1);
 278         unsigned int nr_dirty;
 279         int err;
 280
 281         nr_dirty = nilfs_page_count_clean_buffers(page, start,
 282                                                   start + copied);
 283         copied = generic_write_end(file, mapping, pos, len, copied, page,
 284                                    fsdata);
 285         nilfs_set_file_dirty(inode, nr_dirty);
 286         err = nilfs_transaction_commit(inode->i_sb);
 287         return err ? : copied;
 288 }
 289
 290 static ssize_t
 291 nilfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
 292 {
 293         struct inode *inode = file_inode(iocb->ki_filp);
 294
 295         if (iov_iter_rw(iter) == WRITE)
 296                 return 0;
 297
 298         /* Needs synchronization with the cleaner */
 299         return blockdev_direct_IO(iocb, inode, iter, nilfs_get_block);
 300 }
 301
 302 const struct address_space_operations nilfs_aops = {
 303         .writepage              = nilfs_writepage,
 304         .readpage               = nilfs_readpage,
 305         .writepages             = nilfs_writepages,
 306         .set_page_dirty         = nilfs_set_page_dirty,
 307         .readahead              = nilfs_readahead,
 308         .write_begin            = nilfs_write_begin,
 309         .write_end              = nilfs_write_end,
 310         /* .releasepage         = nilfs_releasepage, */
 311         .invalidatepage         = block_invalidatepage,
 312         .direct_IO              = nilfs_direct_IO,
 313         .is_partially_uptodate  = block_is_partially_uptodate,
 314 };
 315
 316 static int nilfs_insert_inode_locked(struct inode *inode,
 317                                      struct nilfs_root *root,
 318                                      unsigned long ino)
 319 {
 320         struct nilfs_iget_args args = {
 321                 .ino = ino, .root = root, .cno = 0, .for_gc = false,
 322                 .for_btnc = false, .for_shadow = false
 323         };
 324
 325         return insert_inode_locked4(inode, ino, nilfs_iget_test, &args);
 326 }
 327
 328 struct inode *nilfs_new_inode(struct inode *dir, umode_t mode)
 329 {
 330         struct super_block *sb = dir->i_sb;
 331         struct the_nilfs *nilfs = sb->s_fs_info;
 332         struct inode *inode;
 333         struct nilfs_inode_info *ii;
 334         struct nilfs_root *root;
 335         struct buffer_head *bh;
 336         int err = -ENOMEM;
 337         ino_t ino;
 338
 339         inode = new_inode(sb);
 340         if (unlikely(!inode))
 341                 goto failed;
 342
 343         mapping_set_gfp_mask(inode->i_mapping,
 344                            mapping_gfp_constraint(inode->i_mapping, ~__GFP_FS));
 345
 346         root = NILFS_I(dir)->i_root;
 347         ii = NILFS_I(inode);
 348         ii->i_state = BIT(NILFS_I_NEW);
 349         ii->i_root = root;
 350
 351         err = nilfs_ifile_create_inode(root->ifile, &ino, &bh);
 352         if (unlikely(err))
 353                 goto failed_ifile_create_inode;
 354         /* reference count of i_bh inherits from nilfs_mdt_read_block() */
 355
 356         if (unlikely(ino < NILFS_USER_INO)) {
 357                 nilfs_warn(sb,
 358                            "inode bitmap is inconsistent for reserved inodes");
 359                 do {
 360                         brelse(bh);
 361                         err = nilfs_ifile_create_inode(root->ifile, &ino, &bh);
 362                         if (unlikely(err))
 363                                 goto failed_ifile_create_inode;
 364                 } while (ino < NILFS_USER_INO);
 365
 366                 nilfs_info(sb, "repaired inode bitmap for reserved inodes");
 367         }
 368         ii->i_bh = bh;
 369
 370         atomic64_inc(&root->inodes_count);
 371         inode_init_owner(inode, dir, mode);
 372         inode->i_ino = ino;
 373         inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
 374
 375         if (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)) {
 376                 err = nilfs_bmap_read(ii->i_bmap, NULL);
 377                 if (err < 0)
 378                         goto failed_after_creation;
 379
 380                 set_bit(NILFS_I_BMAP, &ii->i_state);
 381                 /* No lock is needed; iget() ensures it. */
 382         }
 383
 384         ii->i_flags = nilfs_mask_flags(
 385                 mode, NILFS_I(dir)->i_flags & NILFS_FL_INHERITED);
 386
 387         /* ii->i_file_acl = 0; */
 388         /* ii->i_dir_acl = 0; */
 389         ii->i_dir_start_lookup = 0;
 390         nilfs_set_inode_flags(inode);
 391         spin_lock(&nilfs->ns_next_gen_lock);
 392         inode->i_generation = nilfs->ns_next_generation++;
 393         spin_unlock(&nilfs->ns_next_gen_lock);
 394         if (nilfs_insert_inode_locked(inode, root, ino) < 0) {
 395                 err = -EIO;
 396                 goto failed_after_creation;
 397         }
 398
 399         err = nilfs_init_acl(inode, dir);
 400         if (unlikely(err))
 401                 /*
 402                  * Never occur.  When supporting nilfs_init_acl(),
 403                  * proper cancellation of above jobs should be considered.
 404                  */
 405                 goto failed_after_creation;
 406
 407         return inode;
 408
 409  failed_after_creation:
 410         clear_nlink(inode);
 411         if (inode->i_state & I_NEW)
 412                 unlock_new_inode(inode);
 413         iput(inode);  /*
 414                        * raw_inode will be deleted through
 415                        * nilfs_evict_inode().
 416                        */
 417         goto failed;
 418
 419  failed_ifile_create_inode:
 420         make_bad_inode(inode);
 421         iput(inode);
 422  failed:
 423         return ERR_PTR(err);
 424 }
 425
 426 void nilfs_set_inode_flags(struct inode *inode)
 427 {
 428         unsigned int flags = NILFS_I(inode)->i_flags;
 429         unsigned int new_fl = 0;
 430
 431         if (flags & FS_SYNC_FL)
 432                 new_fl |= S_SYNC;
 433         if (flags & FS_APPEND_FL)
 434                 new_fl |= S_APPEND;
 435         if (flags & FS_IMMUTABLE_FL)
 436                 new_fl |= S_IMMUTABLE;
 437         if (flags & FS_NOATIME_FL)
 438                 new_fl |= S_NOATIME;
 439         if (flags & FS_DIRSYNC_FL)
 440                 new_fl |= S_DIRSYNC;
 441         inode_set_flags(inode, new_fl, S_SYNC | S_APPEND | S_IMMUTABLE |
 442                         S_NOATIME | S_DIRSYNC);
 443 }
 444
 445 int nilfs_read_inode_common(struct inode *inode,
 446                             struct nilfs_inode *raw_inode)
 447 {
 448         struct nilfs_inode_info *ii = NILFS_I(inode);
 449         int err;
 450
 451         inode->i_mode = le16_to_cpu(raw_inode->i_mode);
 452         i_uid_write(inode, le32_to_cpu(raw_inode->i_uid));
 453         i_gid_write(inode, le32_to_cpu(raw_inode->i_gid));
 454         set_nlink(inode, le16_to_cpu(raw_inode->i_links_count));
 455         inode->i_size = le64_to_cpu(raw_inode->i_size);
 456         inode->i_atime.tv_sec = le64_to_cpu(raw_inode->i_mtime);
 457         inode->i_ctime.tv_sec = le64_to_cpu(raw_inode->i_ctime);
 458         inode->i_mtime.tv_sec = le64_to_cpu(raw_inode->i_mtime);
 459         inode->i_atime.tv_nsec = le32_to_cpu(raw_inode->i_mtime_nsec);
 460         inode->i_ctime.tv_nsec = le32_to_cpu(raw_inode->i_ctime_nsec);
 461         inode->i_mtime.tv_nsec = le32_to_cpu(raw_inode->i_mtime_nsec);
 462         if (nilfs_is_metadata_file_inode(inode) && !S_ISREG(inode->i_mode))
 463                 return -EIO; /* this inode is for metadata and corrupted */
 464         if (inode->i_nlink == 0)
 465                 return -ESTALE; /* this inode is deleted */
 466
 467         inode->i_blocks = le64_to_cpu(raw_inode->i_blocks);
 468         ii->i_flags = le32_to_cpu(raw_inode->i_flags);
 469 #if 0
 470         ii->i_file_acl = le32_to_cpu(raw_inode->i_file_acl);
 471         ii->i_dir_acl = S_ISREG(inode->i_mode) ?
 472                 0 : le32_to_cpu(raw_inode->i_dir_acl);
 473 #endif
 474         ii->i_dir_start_lookup = 0;
 475         inode->i_generation = le32_to_cpu(raw_inode->i_generation);
 476
 477         if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
 478             S_ISLNK(inode->i_mode)) {
 479                 err = nilfs_bmap_read(ii->i_bmap, raw_inode);
 480                 if (err < 0)
 481                         return err;
 482                 set_bit(NILFS_I_BMAP, &ii->i_state);
 483                 /* No lock is needed; iget() ensures it. */
 484         }
 485         return 0;
 486 }
 487
 488 static int __nilfs_read_inode(struct super_block *sb,
 489                               struct nilfs_root *root, unsigned long ino,
 490                               struct inode *inode)
 491 {
 492         struct the_nilfs *nilfs = sb->s_fs_info;
 493         struct buffer_head *bh;
 494         struct nilfs_inode *raw_inode;
 495         int err;
 496
 497         down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
 498         err = nilfs_ifile_get_inode_block(root->ifile, ino, &bh);
 499         if (unlikely(err))
 500                 goto bad_inode;
 501
 502         raw_inode = nilfs_ifile_map_inode(root->ifile, ino, bh);
 503
 504         err = nilfs_read_inode_common(inode, raw_inode);
 505         if (err)
 506                 goto failed_unmap;
 507
 508         if (S_ISREG(inode->i_mode)) {
 509                 inode->i_op = &nilfs_file_inode_operations;
 510                 inode->i_fop = &nilfs_file_operations;
 511                 inode->i_mapping->a_ops = &nilfs_aops;
 512         } else if (S_ISDIR(inode->i_mode)) {
 513                 inode->i_op = &nilfs_dir_inode_operations;
 514                 inode->i_fop = &nilfs_dir_operations;
 515                 inode->i_mapping->a_ops = &nilfs_aops;
 516         } else if (S_ISLNK(inode->i_mode)) {
 517                 inode->i_op = &nilfs_symlink_inode_operations;
 518                 inode_nohighmem(inode);
 519                 inode->i_mapping->a_ops = &nilfs_aops;
 520         } else {
 521                 inode->i_op = &nilfs_special_inode_operations;
 522                 init_special_inode(
 523                         inode, inode->i_mode,
 524                         huge_decode_dev(le64_to_cpu(raw_inode->i_device_code)));
 525         }
 526         nilfs_ifile_unmap_inode(root->ifile, ino, bh);
 527         brelse(bh);
 528         up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
 529         nilfs_set_inode_flags(inode);
 530         mapping_set_gfp_mask(inode->i_mapping,
 531                            mapping_gfp_constraint(inode->i_mapping, ~__GFP_FS));
 532         return 0;
 533
 534  failed_unmap:
 535         nilfs_ifile_unmap_inode(root->ifile, ino, bh);
 536         brelse(bh);
 537
 538  bad_inode:
 539         up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
 540         return err;
 541 }
 542
 543 static int nilfs_iget_test(struct inode *inode, void *opaque)
 544 {
 545         struct nilfs_iget_args *args = opaque;
 546         struct nilfs_inode_info *ii;
 547
 548         if (args->ino != inode->i_ino || args->root != NILFS_I(inode)->i_root)
 549                 return 0;
 550
 551         ii = NILFS_I(inode);
 552         if (test_bit(NILFS_I_BTNC, &ii->i_state)) {
 553                 if (!args->for_btnc)
 554                         return 0;
 555         } else if (args->for_btnc) {
 556                 return 0;
 557         }
 558         if (test_bit(NILFS_I_SHADOW, &ii->i_state)) {
 559                 if (!args->for_shadow)
 560                         return 0;
 561         } else if (args->for_shadow) {
 562                 return 0;
 563         }
 564
 565         if (!test_bit(NILFS_I_GCINODE, &ii->i_state))
 566                 return !args->for_gc;
 567
 568         return args->for_gc && args->cno == ii->i_cno;
 569 }
 570
 571 static int nilfs_iget_set(struct inode *inode, void *opaque)
 572 {
 573         struct nilfs_iget_args *args = opaque;
 574
 575         inode->i_ino = args->ino;
 576         NILFS_I(inode)->i_cno = args->cno;
 577         NILFS_I(inode)->i_root = args->root;
 578         if (args->root && args->ino == NILFS_ROOT_INO)
 579                 nilfs_get_root(args->root);
 580
 581         if (args->for_gc)
 582                 NILFS_I(inode)->i_state = BIT(NILFS_I_GCINODE);
 583         if (args->for_btnc)
 584                 NILFS_I(inode)->i_state |= BIT(NILFS_I_BTNC);
 585         if (args->for_shadow)
 586                 NILFS_I(inode)->i_state |= BIT(NILFS_I_SHADOW);
 587         return 0;
 588 }
 589
 590 struct inode *nilfs_ilookup(struct super_block *sb, struct nilfs_root *root,
 591                             unsigned long ino)
 592 {
 593         struct nilfs_iget_args args = {
 594                 .ino = ino, .root = root, .cno = 0, .for_gc = false,
 595                 .for_btnc = false, .for_shadow = false
 596         };
 597
 598         return ilookup5(sb, ino, nilfs_iget_test, &args);
 599 }
 600
 601 struct inode *nilfs_iget_locked(struct super_block *sb, struct nilfs_root *root,
 602                                 unsigned long ino)
 603 {
 604         struct nilfs_iget_args args = {
 605                 .ino = ino, .root = root, .cno = 0, .for_gc = false,
 606                 .for_btnc = false, .for_shadow = false
 607         };
 608
 609         return iget5_locked(sb, ino, nilfs_iget_test, nilfs_iget_set, &args);
 610 }
 611
 612 struct inode *nilfs_iget(struct super_block *sb, struct nilfs_root *root,
 613                          unsigned long ino)
 614 {
 615         struct inode *inode;
 616         int err;
 617
 618         inode = nilfs_iget_locked(sb, root, ino);
 619         if (unlikely(!inode))
 620                 return ERR_PTR(-ENOMEM);
 621         if (!(inode->i_state & I_NEW))
 622                 return inode;
 623
 624         err = __nilfs_read_inode(sb, root, ino, inode);
 625         if (unlikely(err)) {
 626                 iget_failed(inode);
 627                 return ERR_PTR(err);
 628         }
 629         unlock_new_inode(inode);
 630         return inode;
 631 }
 632
 633 struct inode *nilfs_iget_for_gc(struct super_block *sb, unsigned long ino,
 634                                 __u64 cno)
 635 {
 636         struct nilfs_iget_args args = {
 637                 .ino = ino, .root = NULL, .cno = cno, .for_gc = true,
 638                 .for_btnc = false, .for_shadow = false
 639         };
 640         struct inode *inode;
 641         int err;
 642
 643         inode = iget5_locked(sb, ino, nilfs_iget_test, nilfs_iget_set, &args);
 644         if (unlikely(!inode))
 645                 return ERR_PTR(-ENOMEM);
 646         if (!(inode->i_state & I_NEW))
 647                 return inode;
 648
 649         err = nilfs_init_gcinode(inode);
 650         if (unlikely(err)) {
 651                 iget_failed(inode);
 652                 return ERR_PTR(err);
 653         }
 654         unlock_new_inode(inode);
 655         return inode;
 656 }
 657
 658 /**
 659  * nilfs_attach_btree_node_cache - attach a B-tree node cache to the inode
 660  * @inode: inode object
 661  *
 662  * nilfs_attach_btree_node_cache() attaches a B-tree node cache to @inode,
 663  * or does nothing if the inode already has it.  This function allocates
 664  * an additional inode to maintain page cache of B-tree nodes one-on-one.
 665  *
 666  * Return Value: On success, 0 is returned. On errors, one of the following
 667  * negative error code is returned.
 668  *
 669  * %-ENOMEM - Insufficient memory available.
 670  */
 671 int nilfs_attach_btree_node_cache(struct inode *inode)
 672 {
 673         struct nilfs_inode_info *ii = NILFS_I(inode);
 674         struct inode *btnc_inode;
 675         struct nilfs_iget_args args;
 676
 677         if (ii->i_assoc_inode)
 678                 return 0;
 679
 680         args.ino = inode->i_ino;
 681         args.root = ii->i_root;
 682         args.cno = ii->i_cno;
 683         args.for_gc = test_bit(NILFS_I_GCINODE, &ii->i_state) != 0;
 684         args.for_btnc = true;
 685         args.for_shadow = test_bit(NILFS_I_SHADOW, &ii->i_state) != 0;
 686
 687         btnc_inode = iget5_locked(inode->i_sb, inode->i_ino, nilfs_iget_test,
 688                                   nilfs_iget_set, &args);
 689         if (unlikely(!btnc_inode))
 690                 return -ENOMEM;
 691         if (btnc_inode->i_state & I_NEW) {
 692                 nilfs_init_btnc_inode(btnc_inode);
 693                 unlock_new_inode(btnc_inode);
 694         }
 695         NILFS_I(btnc_inode)->i_assoc_inode = inode;
 696         NILFS_I(btnc_inode)->i_bmap = ii->i_bmap;
 697         ii->i_assoc_inode = btnc_inode;
 698
 699         return 0;
 700 }
 701
 702 /**
 703  * nilfs_detach_btree_node_cache - detach the B-tree node cache from the inode
 704  * @inode: inode object
 705  *
 706  * nilfs_detach_btree_node_cache() detaches the B-tree node cache and its
 707  * holder inode bound to @inode, or does nothing if @inode doesn't have it.
 708  */
 709 void nilfs_detach_btree_node_cache(struct inode *inode)
 710 {
 711         struct nilfs_inode_info *ii = NILFS_I(inode);
 712         struct inode *btnc_inode = ii->i_assoc_inode;
 713
 714         if (btnc_inode) {
 715                 NILFS_I(btnc_inode)->i_assoc_inode = NULL;
 716                 ii->i_assoc_inode = NULL;
 717                 iput(btnc_inode);
 718         }
 719 }
 720
 721 /**
 722  * nilfs_iget_for_shadow - obtain inode for shadow mapping
 723  * @inode: inode object that uses shadow mapping
 724  *
 725  * nilfs_iget_for_shadow() allocates a pair of inodes that holds page
 726  * caches for shadow mapping.  The page cache for data pages is set up
 727  * in one inode and the one for b-tree node pages is set up in the
 728  * other inode, which is attached to the former inode.
 729  *
 730  * Return Value: On success, a pointer to the inode for data pages is
 731  * returned. On errors, one of the following negative error code is returned
 732  * in a pointer type.
 733  *
 734  * %-ENOMEM - Insufficient memory available.
 735  */
 736 struct inode *nilfs_iget_for_shadow(struct inode *inode)
 737 {
 738         struct nilfs_iget_args args = {
 739                 .ino = inode->i_ino, .root = NULL, .cno = 0, .for_gc = false,
 740                 .for_btnc = false, .for_shadow = true
 741         };
 742         struct inode *s_inode;
 743         int err;
 744
 745         s_inode = iget5_locked(inode->i_sb, inode->i_ino, nilfs_iget_test,
 746                                nilfs_iget_set, &args);
 747         if (unlikely(!s_inode))
 748                 return ERR_PTR(-ENOMEM);
 749         if (!(s_inode->i_state & I_NEW))
 750                 return inode;
 751
 752         NILFS_I(s_inode)->i_flags = 0;
 753         memset(NILFS_I(s_inode)->i_bmap, 0, sizeof(struct nilfs_bmap));
 754         mapping_set_gfp_mask(s_inode->i_mapping, GFP_NOFS);
 755
 756         err = nilfs_attach_btree_node_cache(s_inode);
 757         if (unlikely(err)) {
 758                 iget_failed(s_inode);
 759                 return ERR_PTR(err);
 760         }
 761         unlock_new_inode(s_inode);
 762         return s_inode;
 763 }
 764
 765 void nilfs_write_inode_common(struct inode *inode,
 766                               struct nilfs_inode *raw_inode, int has_bmap)
 767 {
 768         struct nilfs_inode_info *ii = NILFS_I(inode);
 769
 770         raw_inode->i_mode = cpu_to_le16(inode->i_mode);
 771         raw_inode->i_uid = cpu_to_le32(i_uid_read(inode));
 772         raw_inode->i_gid = cpu_to_le32(i_gid_read(inode));
 773         raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
 774         raw_inode->i_size = cpu_to_le64(inode->i_size);
 775         raw_inode->i_ctime = cpu_to_le64(inode->i_ctime.tv_sec);
 776         raw_inode->i_mtime = cpu_to_le64(inode->i_mtime.tv_sec);
 777         raw_inode->i_ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
 778         raw_inode->i_mtime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec);
 779         raw_inode->i_blocks = cpu_to_le64(inode->i_blocks);
 780
 781         raw_inode->i_flags = cpu_to_le32(ii->i_flags);
 782         raw_inode->i_generation = cpu_to_le32(inode->i_generation);
 783
 784         if (NILFS_ROOT_METADATA_FILE(inode->i_ino)) {
 785                 struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
 786
 787                 /* zero-fill unused portion in the case of super root block */
 788                 raw_inode->i_xattr = 0;
 789                 raw_inode->i_pad = 0;
 790                 memset((void *)raw_inode + sizeof(*raw_inode), 0,
 791                        nilfs->ns_inode_size - sizeof(*raw_inode));
 792         }
 793
 794         if (has_bmap)
 795                 nilfs_bmap_write(ii->i_bmap, raw_inode);
 796         else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
 797                 raw_inode->i_device_code =
 798                         cpu_to_le64(huge_encode_dev(inode->i_rdev));
 799         /*
 800          * When extending inode, nilfs->ns_inode_size should be checked
 801          * for substitutions of appended fields.
 802          */
 803 }
 804
 805 void nilfs_update_inode(struct inode *inode, struct buffer_head *ibh, int flags)
 806 {
 807         ino_t ino = inode->i_ino;
 808         struct nilfs_inode_info *ii = NILFS_I(inode);
 809         struct inode *ifile = ii->i_root->ifile;
 810         struct nilfs_inode *raw_inode;
 811
 812         raw_inode = nilfs_ifile_map_inode(ifile, ino, ibh);
 813
 814         if (test_and_clear_bit(NILFS_I_NEW, &ii->i_state))
 815                 memset(raw_inode, 0, NILFS_MDT(ifile)->mi_entry_size);
 816         if (flags & I_DIRTY_DATASYNC)
 817                 set_bit(NILFS_I_INODE_SYNC, &ii->i_state);
 818
 819         nilfs_write_inode_common(inode, raw_inode, 0);
 820                 /*
 821                  * XXX: call with has_bmap = 0 is a workaround to avoid
 822                  * deadlock of bmap.  This delays update of i_bmap to just
 823                  * before writing.
 824                  */
 825
 826         nilfs_ifile_unmap_inode(ifile, ino, ibh);
 827 }
 828
 829 #define NILFS_MAX_TRUNCATE_BLOCKS       16384  /* 64MB for 4KB block */
 830
 831 static void nilfs_truncate_bmap(struct nilfs_inode_info *ii,
 832                                 unsigned long from)
 833 {
 834         __u64 b;
 835         int ret;
 836
 837         if (!test_bit(NILFS_I_BMAP, &ii->i_state))
 838                 return;
 839 repeat:
 840         ret = nilfs_bmap_last_key(ii->i_bmap, &b);
 841         if (ret == -ENOENT)
 842                 return;
 843         else if (ret < 0)
 844                 goto failed;
 845
 846         if (b < from)
 847                 return;
 848
 849         b -= min_t(__u64, NILFS_MAX_TRUNCATE_BLOCKS, b - from);
 850         ret = nilfs_bmap_truncate(ii->i_bmap, b);
 851         nilfs_relax_pressure_in_lock(ii->vfs_inode.i_sb);
 852         if (!ret || (ret == -ENOMEM &&
 853                      nilfs_bmap_truncate(ii->i_bmap, b) == 0))
 854                 goto repeat;
 855
 856 failed:
 857         nilfs_warn(ii->vfs_inode.i_sb, "error %d truncating bmap (ino=%lu)",
 858                    ret, ii->vfs_inode.i_ino);
 859 }
 860
 861 void nilfs_truncate(struct inode *inode)
 862 {
 863         unsigned long blkoff;
 864         unsigned int blocksize;
 865         struct nilfs_transaction_info ti;
 866         struct super_block *sb = inode->i_sb;
 867         struct nilfs_inode_info *ii = NILFS_I(inode);
 868
 869         if (!test_bit(NILFS_I_BMAP, &ii->i_state))
 870                 return;
 871         if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
 872                 return;
 873
 874         blocksize = sb->s_blocksize;
 875         blkoff = (inode->i_size + blocksize - 1) >> sb->s_blocksize_bits;
 876         nilfs_transaction_begin(sb, &ti, 0); /* never fails */
 877
 878         block_truncate_page(inode->i_mapping, inode->i_size, nilfs_get_block);
 879
 880         nilfs_truncate_bmap(ii, blkoff);
 881
 882         inode->i_mtime = inode->i_ctime = current_time(inode);
 883         if (IS_SYNC(inode))
 884                 nilfs_set_transaction_flag(NILFS_TI_SYNC);
 885
 886         nilfs_mark_inode_dirty(inode);
 887         nilfs_set_file_dirty(inode, 0);
 888         nilfs_transaction_commit(sb);
 889         /*
 890          * May construct a logical segment and may fail in sync mode.
 891          * But truncate has no return value.
 892          */
 893 }
 894
 895 static void nilfs_clear_inode(struct inode *inode)
 896 {
 897         struct nilfs_inode_info *ii = NILFS_I(inode);
 898
 899         /*
 900          * Free resources allocated in nilfs_read_inode(), here.
 901          */
 902         BUG_ON(!list_empty(&ii->i_dirty));
 903         brelse(ii->i_bh);
 904         ii->i_bh = NULL;
 905
 906         if (nilfs_is_metadata_file_inode(inode))
 907                 nilfs_mdt_clear(inode);
 908
 909         if (test_bit(NILFS_I_BMAP, &ii->i_state))
 910                 nilfs_bmap_clear(ii->i_bmap);
 911
 912         if (!test_bit(NILFS_I_BTNC, &ii->i_state))
 913                 nilfs_detach_btree_node_cache(inode);
 914
 915         if (ii->i_root && inode->i_ino == NILFS_ROOT_INO)
 916                 nilfs_put_root(ii->i_root);
 917 }
 918
 919 void nilfs_evict_inode(struct inode *inode)
 920 {
 921         struct nilfs_transaction_info ti;
 922         struct super_block *sb = inode->i_sb;
 923         struct nilfs_inode_info *ii = NILFS_I(inode);
 924         int ret;
 925
 926         if (inode->i_nlink || !ii->i_root || unlikely(is_bad_inode(inode))) {
 927                 truncate_inode_pages_final(&inode->i_data);
 928                 clear_inode(inode);
 929                 nilfs_clear_inode(inode);
 930                 return;
 931         }
 932         nilfs_transaction_begin(sb, &ti, 0); /* never fails */
 933
 934         truncate_inode_pages_final(&inode->i_data);
 935
 936         /* TODO: some of the following operations may fail.  */
 937         nilfs_truncate_bmap(ii, 0);
 938         nilfs_mark_inode_dirty(inode);
 939         clear_inode(inode);
 940
 941         ret = nilfs_ifile_delete_inode(ii->i_root->ifile, inode->i_ino);
 942         if (!ret)
 943                 atomic64_dec(&ii->i_root->inodes_count);
 944
 945         nilfs_clear_inode(inode);
 946
 947         if (IS_SYNC(inode))
 948                 nilfs_set_transaction_flag(NILFS_TI_SYNC);
 949         nilfs_transaction_commit(sb);
 950         /*
 951          * May construct a logical segment and may fail in sync mode.
 952          * But delete_inode has no return value.
 953          */
 954 }
 955
 956 int nilfs_setattr(struct dentry *dentry, struct iattr *iattr)
 957 {
 958         struct nilfs_transaction_info ti;
 959         struct inode *inode = d_inode(dentry);
 960         struct super_block *sb = inode->i_sb;
 961         int err;
 962
 963         err = setattr_prepare(dentry, iattr);
 964         if (err)
 965                 return err;
 966
 967         err = nilfs_transaction_begin(sb, &ti, 0);
 968         if (unlikely(err))
 969                 return err;
 970
 971         if ((iattr->ia_valid & ATTR_SIZE) &&
 972             iattr->ia_size != i_size_read(inode)) {
 973                 inode_dio_wait(inode);
 974                 truncate_setsize(inode, iattr->ia_size);
 975                 nilfs_truncate(inode);
 976         }
 977
 978         setattr_copy(inode, iattr);
 979         mark_inode_dirty(inode);
 980
 981         if (iattr->ia_valid & ATTR_MODE) {
 982                 err = nilfs_acl_chmod(inode);
 983                 if (unlikely(err))
 984                         goto out_err;
 985         }
 986
 987         return nilfs_transaction_commit(sb);
 988
 989 out_err:
 990         nilfs_transaction_abort(sb);
 991         return err;
 992 }
 993
 994 int nilfs_permission(struct inode *inode, int mask)
 995 {
 996         struct nilfs_root *root = NILFS_I(inode)->i_root;
 997
 998         if ((mask & MAY_WRITE) && root &&
 999             root->cno != NILFS_CPTREE_CURRENT_CNO)
1000                 return -EROFS; /* snapshot is not writable */
1001
1002         return generic_permission(inode, mask);
1003 }
1004
1005 int nilfs_load_inode_block(struct inode *inode, struct buffer_head **pbh)
1006 {
1007         struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
1008         struct nilfs_inode_info *ii = NILFS_I(inode);
1009         int err;
1010
1011         spin_lock(&nilfs->ns_inode_lock);
1012         if (ii->i_bh == NULL) {
1013                 spin_unlock(&nilfs->ns_inode_lock);
1014                 err = nilfs_ifile_get_inode_block(ii->i_root->ifile,
1015                                                   inode->i_ino, pbh);
1016                 if (unlikely(err))
1017                         return err;
1018                 spin_lock(&nilfs->ns_inode_lock);
1019                 if (ii->i_bh == NULL)
1020                         ii->i_bh = *pbh;
1021                 else {
1022                         brelse(*pbh);
1023                         *pbh = ii->i_bh;
1024                 }
1025         } else
1026                 *pbh = ii->i_bh;
1027
1028         get_bh(*pbh);
1029         spin_unlock(&nilfs->ns_inode_lock);
1030         return 0;
1031 }
1032
1033 int nilfs_inode_dirty(struct inode *inode)
1034 {
1035         struct nilfs_inode_info *ii = NILFS_I(inode);
1036         struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
1037         int ret = 0;
1038
1039         if (!list_empty(&ii->i_dirty)) {
1040                 spin_lock(&nilfs->ns_inode_lock);
1041                 ret = test_bit(NILFS_I_DIRTY, &ii->i_state) ||
1042                         test_bit(NILFS_I_BUSY, &ii->i_state);
1043                 spin_unlock(&nilfs->ns_inode_lock);
1044         }
1045         return ret;
1046 }
1047
1048 int nilfs_set_file_dirty(struct inode *inode, unsigned int nr_dirty)
1049 {
1050         struct nilfs_inode_info *ii = NILFS_I(inode);
1051         struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
1052
1053         atomic_add(nr_dirty, &nilfs->ns_ndirtyblks);
1054
1055         if (test_and_set_bit(NILFS_I_DIRTY, &ii->i_state))
1056                 return 0;
1057
1058         spin_lock(&nilfs->ns_inode_lock);
1059         if (!test_bit(NILFS_I_QUEUED, &ii->i_state) &&
1060             !test_bit(NILFS_I_BUSY, &ii->i_state)) {
1061                 /*
1062                  * Because this routine may race with nilfs_dispose_list(),
1063                  * we have to check NILFS_I_QUEUED here, too.
1064                  */
1065                 if (list_empty(&ii->i_dirty) && igrab(inode) == NULL) {
1066                         /*
1067                          * This will happen when somebody is freeing
1068                          * this inode.
1069                          */
1070                         nilfs_warn(inode->i_sb,
1071                                    "cannot set file dirty (ino=%lu): the file is being freed",
1072                                    inode->i_ino);
1073                         spin_unlock(&nilfs->ns_inode_lock);
1074                         return -EINVAL; /*
1075                                          * NILFS_I_DIRTY may remain for
1076                                          * freeing inode.
1077                                          */
1078                 }
1079                 list_move_tail(&ii->i_dirty, &nilfs->ns_dirty_files);
1080                 set_bit(NILFS_I_QUEUED, &ii->i_state);
1081         }
1082         spin_unlock(&nilfs->ns_inode_lock);
1083         return 0;
1084 }
1085
1086 int __nilfs_mark_inode_dirty(struct inode *inode, int flags)
1087 {
1088         struct buffer_head *ibh;
1089         int err;
1090
1091         err = nilfs_load_inode_block(inode, &ibh);
1092         if (unlikely(err)) {
1093                 nilfs_warn(inode->i_sb,
1094                            "cannot mark inode dirty (ino=%lu): error %d loading inode block",
1095                            inode->i_ino, err);
1096                 return err;
1097         }
1098         nilfs_update_inode(inode, ibh, flags);
1099         mark_buffer_dirty(ibh);
1100         nilfs_mdt_mark_dirty(NILFS_I(inode)->i_root->ifile);
1101         brelse(ibh);
1102         return 0;
1103 }
1104
1105 /**
1106  * nilfs_dirty_inode - reflect changes on given inode to an inode block.
1107  * @inode: inode of the file to be registered.
1108  *
1109  * nilfs_dirty_inode() loads a inode block containing the specified
1110  * @inode and copies data from a nilfs_inode to a corresponding inode
1111  * entry in the inode block. This operation is excluded from the segment
1112  * construction. This function can be called both as a single operation
1113  * and as a part of indivisible file operations.
1114  */
1115 void nilfs_dirty_inode(struct inode *inode, int flags)
1116 {
1117         struct nilfs_transaction_info ti;
1118         struct nilfs_mdt_info *mdi = NILFS_MDT(inode);
1119
1120         if (is_bad_inode(inode)) {
1121                 nilfs_warn(inode->i_sb,
1122                            "tried to mark bad_inode dirty. ignored.");
1123                 dump_stack();
1124                 return;
1125         }
1126         if (mdi) {
1127                 nilfs_mdt_mark_dirty(inode);
1128                 return;
1129         }
1130         nilfs_transaction_begin(inode->i_sb, &ti, 0);
1131         __nilfs_mark_inode_dirty(inode, flags);
1132         nilfs_transaction_commit(inode->i_sb); /* never fails */
1133 }
1134
1135 int nilfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
1136                  __u64 start, __u64 len)
1137 {
1138         struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
1139         __u64 logical = 0, phys = 0, size = 0;
1140         __u32 flags = 0;
1141         loff_t isize;
1142         sector_t blkoff, end_blkoff;
1143         sector_t delalloc_blkoff;
1144         unsigned long delalloc_blklen;
1145         unsigned int blkbits = inode->i_blkbits;
1146         int ret, n;
1147
1148         ret = fiemap_prep(inode, fieinfo, start, &len, 0);
1149         if (ret)
1150                 return ret;
1151
1152         inode_lock(inode);
1153
1154         isize = i_size_read(inode);
1155
1156         blkoff = start >> blkbits;
1157         end_blkoff = (start + len - 1) >> blkbits;
1158
1159         delalloc_blklen = nilfs_find_uncommitted_extent(inode, blkoff,
1160                                                         &delalloc_blkoff);
1161
1162         do {
1163                 __u64 blkphy;
1164                 unsigned int maxblocks;
1165
1166                 if (delalloc_blklen && blkoff == delalloc_blkoff) {
1167                         if (size) {
1168                                 /* End of the current extent */
1169                                 ret = fiemap_fill_next_extent(
1170                                         fieinfo, logical, phys, size, flags);
1171                                 if (ret)
1172                                         break;
1173                         }
1174                         if (blkoff > end_blkoff)
1175                                 break;
1176
1177                         flags = FIEMAP_EXTENT_MERGED | FIEMAP_EXTENT_DELALLOC;
1178                         logical = blkoff << blkbits;
1179                         phys = 0;
1180                         size = delalloc_blklen << blkbits;
1181
1182                         blkoff = delalloc_blkoff + delalloc_blklen;
1183                         delalloc_blklen = nilfs_find_uncommitted_extent(
1184                                 inode, blkoff, &delalloc_blkoff);
1185                         continue;
1186                 }
1187
1188                 /*
1189                  * Limit the number of blocks that we look up so as
1190                  * not to get into the next delayed allocation extent.
1191                  */
1192                 maxblocks = INT_MAX;
1193                 if (delalloc_blklen)
1194                         maxblocks = min_t(sector_t, delalloc_blkoff - blkoff,
1195                                           maxblocks);
1196                 blkphy = 0;
1197
1198                 down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
1199                 n = nilfs_bmap_lookup_contig(
1200                         NILFS_I(inode)->i_bmap, blkoff, &blkphy, maxblocks);
1201                 up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
1202
1203                 if (n < 0) {
1204                         int past_eof;
1205
1206                         if (unlikely(n != -ENOENT))
1207                                 break; /* error */
1208
1209                         /* HOLE */
1210                         blkoff++;
1211                         past_eof = ((blkoff << blkbits) >= isize);
1212
1213                         if (size) {
1214                                 /* End of the current extent */
1215
1216                                 if (past_eof)
1217                                         flags |= FIEMAP_EXTENT_LAST;
1218
1219                                 ret = fiemap_fill_next_extent(
1220                                         fieinfo, logical, phys, size, flags);
1221                                 if (ret)
1222                                         break;
1223                                 size = 0;
1224                         }
1225                         if (blkoff > end_blkoff || past_eof)
1226                                 break;
1227                 } else {
1228                         if (size) {
1229                                 if (phys && blkphy << blkbits == phys + size) {
1230                                         /* The current extent goes on */
1231                                         size += n << blkbits;
1232                                 } else {
1233                                         /* Terminate the current extent */
1234                                         ret = fiemap_fill_next_extent(
1235                                                 fieinfo, logical, phys, size,
1236                                                 flags);
1237                                         if (ret || blkoff > end_blkoff)
1238                                                 break;
1239
1240                                         /* Start another extent */
1241                                         flags = FIEMAP_EXTENT_MERGED;
1242                                         logical = blkoff << blkbits;
1243                                         phys = blkphy << blkbits;
1244                                         size = n << blkbits;
1245                                 }
1246                         } else {
1247                                 /* Start a new extent */
1248                                 flags = FIEMAP_EXTENT_MERGED;
1249                                 logical = blkoff << blkbits;
1250                                 phys = blkphy << blkbits;
1251                                 size = n << blkbits;
1252                         }
1253                         blkoff += n;
1254                 }
1255                 cond_resched();
1256         } while (true);
1257
1258         /* If ret is 1 then we just hit the end of the extent array */
1259         if (ret == 1)
1260                 ret = 0;
1261
1262         inode_unlock(inode);
1263         return ret;
1264 }