fs/ext4/namei.c

   1 /*
   2  *  linux/fs/ext4/namei.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Laboratoire MASI - Institut Blaise Pascal
   7  * Universite Pierre et Marie Curie (Paris VI)
   8  *
   9  *  from
  10  *
  11  *  linux/fs/minix/namei.c
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  *
  15  *  Big-endian to little-endian byte-swapping/bitmaps by
  16  *        David S. Miller (davem@caip.rutgers.edu), 1995
  17  *  Directory entry file type support and forward compatibility hooks
  18  *      for B-tree directories by Theodore Ts'o (tytso@mit.edu), 1998
  19  *  Hash Tree Directory indexing (c)
  20  *      Daniel Phillips, 2001
  21  *  Hash Tree Directory indexing porting
  22  *      Christopher Li, 2002
  23  *  Hash Tree Directory indexing cleanup
  24  *      Theodore Ts'o, 2002
  25  */
  26
  27 #include <linux/fs.h>
  28 #include <linux/pagemap.h>
  29 #include <linux/time.h>
  30 #include <linux/fcntl.h>
  31 #include <linux/stat.h>
  32 #include <linux/string.h>
  33 #include <linux/quotaops.h>
  34 #include <linux/buffer_head.h>
  35 #include <linux/bio.h>
  36 #include "ext4.h"
  37 #include "ext4_jbd2.h"
  38
  39 #include "xattr.h"
  40 #include "acl.h"
  41
  42 #include <trace/events/ext4.h>
  43 /*
  44  * define how far ahead to read directories while searching them.
  45  */
  46 #define NAMEI_RA_CHUNKS  2
  47 #define NAMEI_RA_BLOCKS  4
  48 #define NAMEI_RA_SIZE        (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS)
  49
  50 static struct buffer_head *ext4_append(handle_t *handle,
  51                                         struct inode *inode,
  52                                         ext4_lblk_t *block)
  53 {
  54         struct buffer_head *bh;
  55         int err;
  56
  57         if (unlikely(EXT4_SB(inode->i_sb)->s_max_dir_size_kb &&
  58                      ((inode->i_size >> 10) >=
  59                       EXT4_SB(inode->i_sb)->s_max_dir_size_kb)))
  60                 return ERR_PTR(-ENOSPC);
  61
  62         *block = inode->i_size >> inode->i_sb->s_blocksize_bits;
  63
  64         bh = ext4_bread(handle, inode, *block, EXT4_GET_BLOCKS_CREATE);
  65         if (IS_ERR(bh))
  66                 return bh;
  67         inode->i_size += inode->i_sb->s_blocksize;
  68         EXT4_I(inode)->i_disksize = inode->i_size;
  69         BUFFER_TRACE(bh, "get_write_access");
  70         err = ext4_journal_get_write_access(handle, bh);
  71         if (err) {
  72                 brelse(bh);
  73                 ext4_std_error(inode->i_sb, err);
  74                 return ERR_PTR(err);
  75         }
  76         return bh;
  77 }
  78
  79 static int ext4_dx_csum_verify(struct inode *inode,
  80                                struct ext4_dir_entry *dirent);
  81
  82 typedef enum {
  83         EITHER, INDEX, DIRENT
  84 } dirblock_type_t;
  85
  86 #define ext4_read_dirblock(inode, block, type) \
  87         __ext4_read_dirblock((inode), (block), (type), __func__, __LINE__)
  88
  89 static struct buffer_head *__ext4_read_dirblock(struct inode *inode,
  90                                                 ext4_lblk_t block,
  91                                                 dirblock_type_t type,
  92                                                 const char *func,
  93                                                 unsigned int line)
  94 {
  95         struct buffer_head *bh;
  96         struct ext4_dir_entry *dirent;
  97         int is_dx_block = 0;
  98
  99         bh = ext4_bread(NULL, inode, block, 0);
 100         if (IS_ERR(bh)) {
 101                 __ext4_warning(inode->i_sb, func, line,
 102                                "inode #%lu: lblock %lu: comm %s: "
 103                                "error %ld reading directory block",
 104                                inode->i_ino, (unsigned long)block,
 105                                current->comm, PTR_ERR(bh));
 106
 107                 return bh;
 108         }
 109         if (!bh) {
 110                 ext4_error_inode(inode, func, line, block,
 111                                  "Directory hole found");
 112                 return ERR_PTR(-EFSCORRUPTED);
 113         }
 114         dirent = (struct ext4_dir_entry *) bh->b_data;
 115         /* Determine whether or not we have an index block */
 116         if (is_dx(inode)) {
 117                 if (block == 0)
 118                         is_dx_block = 1;
 119                 else if (ext4_rec_len_from_disk(dirent->rec_len,
 120                                                 inode->i_sb->s_blocksize) ==
 121                          inode->i_sb->s_blocksize)
 122                         is_dx_block = 1;
 123         }
 124         if (!is_dx_block && type == INDEX) {
 125                 ext4_error_inode(inode, func, line, block,
 126                        "directory leaf block found instead of index block");
 127                 brelse(bh);
 128                 return ERR_PTR(-EFSCORRUPTED);
 129         }
 130         if (!ext4_has_metadata_csum(inode->i_sb) ||
 131             buffer_verified(bh))
 132                 return bh;
 133
 134         /*
 135          * An empty leaf block can get mistaken for a index block; for
 136          * this reason, we can only check the index checksum when the
 137          * caller is sure it should be an index block.
 138          */
 139         if (is_dx_block && type == INDEX) {
 140                 if (ext4_dx_csum_verify(inode, dirent))
 141                         set_buffer_verified(bh);
 142                 else {
 143                         ext4_error_inode(inode, func, line, block,
 144                                          "Directory index failed checksum");
 145                         brelse(bh);
 146                         return ERR_PTR(-EFSBADCRC);
 147                 }
 148         }
 149         if (!is_dx_block) {
 150                 if (ext4_dirent_csum_verify(inode, dirent))
 151                         set_buffer_verified(bh);
 152                 else {
 153                         ext4_error_inode(inode, func, line, block,
 154                                          "Directory block failed checksum");
 155                         brelse(bh);
 156                         return ERR_PTR(-EFSBADCRC);
 157                 }
 158         }
 159         return bh;
 160 }
 161
 162 #ifndef assert
 163 #define assert(test) J_ASSERT(test)
 164 #endif
 165
 166 #ifdef DX_DEBUG
 167 #define dxtrace(command) command
 168 #else
 169 #define dxtrace(command)
 170 #endif
 171
 172 struct fake_dirent
 173 {
 174         __le32 inode;
 175         __le16 rec_len;
 176         u8 name_len;
 177         u8 file_type;
 178 };
 179
 180 struct dx_countlimit
 181 {
 182         __le16 limit;
 183         __le16 count;
 184 };
 185
 186 struct dx_entry
 187 {
 188         __le32 hash;
 189         __le32 block;
 190 };
 191
 192 /*
 193  * dx_root_info is laid out so that if it should somehow get overlaid by a
 194  * dirent the two low bits of the hash version will be zero.  Therefore, the
 195  * hash version mod 4 should never be 0.  Sincerely, the paranoia department.
 196  */
 197
 198 struct dx_root
 199 {
 200         struct fake_dirent dot;
 201         char dot_name[4];
 202         struct fake_dirent dotdot;
 203         char dotdot_name[4];
 204         struct dx_root_info
 205         {
 206                 __le32 reserved_zero;
 207                 u8 hash_version;
 208                 u8 info_length; /* 8 */
 209                 u8 indirect_levels;
 210                 u8 unused_flags;
 211         }
 212         info;
 213         struct dx_entry entries[0];
 214 };
 215
 216 struct dx_node
 217 {
 218         struct fake_dirent fake;
 219         struct dx_entry entries[0];
 220 };
 221
 222
 223 struct dx_frame
 224 {
 225         struct buffer_head *bh;
 226         struct dx_entry *entries;
 227         struct dx_entry *at;
 228 };
 229
 230 struct dx_map_entry
 231 {
 232         u32 hash;
 233         u16 offs;
 234         u16 size;
 235 };
 236
 237 /*
 238  * This goes at the end of each htree block.
 239  */
 240 struct dx_tail {
 241         u32 dt_reserved;
 242         __le32 dt_checksum;     /* crc32c(uuid+inum+dirblock) */
 243 };
 244
 245 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
 246 static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
 247 static inline unsigned dx_get_hash(struct dx_entry *entry);
 248 static void dx_set_hash(struct dx_entry *entry, unsigned value);
 249 static unsigned dx_get_count(struct dx_entry *entries);
 250 static unsigned dx_get_limit(struct dx_entry *entries);
 251 static void dx_set_count(struct dx_entry *entries, unsigned value);
 252 static void dx_set_limit(struct dx_entry *entries, unsigned value);
 253 static unsigned dx_root_limit(struct inode *dir, unsigned infosize);
 254 static unsigned dx_node_limit(struct inode *dir);
 255 static struct dx_frame *dx_probe(struct ext4_filename *fname,
 256                                  struct inode *dir,
 257                                  struct dx_hash_info *hinfo,
 258                                  struct dx_frame *frame);
 259 static void dx_release(struct dx_frame *frames);
 260 static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de,
 261                        unsigned blocksize, struct dx_hash_info *hinfo,
 262                        struct dx_map_entry map[]);
 263 static void dx_sort_map(struct dx_map_entry *map, unsigned count);
 264 static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to,
 265                 struct dx_map_entry *offsets, int count, unsigned blocksize);
 266 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize);
 267 static void dx_insert_block(struct dx_frame *frame,
 268                                         u32 hash, ext4_lblk_t block);
 269 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
 270                                  struct dx_frame *frame,
 271                                  struct dx_frame *frames,
 272                                  __u32 *start_hash);
 273 static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
 274                 struct ext4_filename *fname,
 275                 struct ext4_dir_entry_2 **res_dir);
 276 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
 277                              struct dentry *dentry, struct inode *inode);
 278
 279 /* checksumming functions */
 280 void initialize_dirent_tail(struct ext4_dir_entry_tail *t,
 281                             unsigned int blocksize)
 282 {
 283         memset(t, 0, sizeof(struct ext4_dir_entry_tail));
 284         t->det_rec_len = ext4_rec_len_to_disk(
 285                         sizeof(struct ext4_dir_entry_tail), blocksize);
 286         t->det_reserved_ft = EXT4_FT_DIR_CSUM;
 287 }
 288
 289 /* Walk through a dirent block to find a checksum "dirent" at the tail */
 290 static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode,
 291                                                    struct ext4_dir_entry *de)
 292 {
 293         struct ext4_dir_entry_tail *t;
 294
 295 #ifdef PARANOID
 296         struct ext4_dir_entry *d, *top;
 297
 298         d = de;
 299         top = (struct ext4_dir_entry *)(((void *)de) +
 300                 (EXT4_BLOCK_SIZE(inode->i_sb) -
 301                 sizeof(struct ext4_dir_entry_tail)));
 302         while (d < top && d->rec_len)
 303                 d = (struct ext4_dir_entry *)(((void *)d) +
 304                     le16_to_cpu(d->rec_len));
 305
 306         if (d != top)
 307                 return NULL;
 308
 309         t = (struct ext4_dir_entry_tail *)d;
 310 #else
 311         t = EXT4_DIRENT_TAIL(de, EXT4_BLOCK_SIZE(inode->i_sb));
 312 #endif
 313
 314         if (t->det_reserved_zero1 ||
 315             le16_to_cpu(t->det_rec_len) != sizeof(struct ext4_dir_entry_tail) ||
 316             t->det_reserved_zero2 ||
 317             t->det_reserved_ft != EXT4_FT_DIR_CSUM)
 318                 return NULL;
 319
 320         return t;
 321 }
 322
 323 static __le32 ext4_dirent_csum(struct inode *inode,
 324                                struct ext4_dir_entry *dirent, int size)
 325 {
 326         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
 327         struct ext4_inode_info *ei = EXT4_I(inode);
 328         __u32 csum;
 329
 330         csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
 331         return cpu_to_le32(csum);
 332 }
 333
 334 #define warn_no_space_for_csum(inode)                                   \
 335         __warn_no_space_for_csum((inode), __func__, __LINE__)
 336
 337 static void __warn_no_space_for_csum(struct inode *inode, const char *func,
 338                                      unsigned int line)
 339 {
 340         __ext4_warning_inode(inode, func, line,
 341                 "No space for directory leaf checksum. Please run e2fsck -D.");
 342 }
 343
 344 int ext4_dirent_csum_verify(struct inode *inode, struct ext4_dir_entry *dirent)
 345 {
 346         struct ext4_dir_entry_tail *t;
 347
 348         if (!ext4_has_metadata_csum(inode->i_sb))
 349                 return 1;
 350
 351         t = get_dirent_tail(inode, dirent);
 352         if (!t) {
 353                 warn_no_space_for_csum(inode);
 354                 return 0;
 355         }
 356
 357         if (t->det_checksum != ext4_dirent_csum(inode, dirent,
 358                                                 (void *)t - (void *)dirent))
 359                 return 0;
 360
 361         return 1;
 362 }
 363
 364 static void ext4_dirent_csum_set(struct inode *inode,
 365                                  struct ext4_dir_entry *dirent)
 366 {
 367         struct ext4_dir_entry_tail *t;
 368
 369         if (!ext4_has_metadata_csum(inode->i_sb))
 370                 return;
 371
 372         t = get_dirent_tail(inode, dirent);
 373         if (!t) {
 374                 warn_no_space_for_csum(inode);
 375                 return;
 376         }
 377
 378         t->det_checksum = ext4_dirent_csum(inode, dirent,
 379                                            (void *)t - (void *)dirent);
 380 }
 381
 382 int ext4_handle_dirty_dirent_node(handle_t *handle,
 383                                   struct inode *inode,
 384                                   struct buffer_head *bh)
 385 {
 386         ext4_dirent_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
 387         return ext4_handle_dirty_metadata(handle, inode, bh);
 388 }
 389
 390 static struct dx_countlimit *get_dx_countlimit(struct inode *inode,
 391                                                struct ext4_dir_entry *dirent,
 392                                                int *offset)
 393 {
 394         struct ext4_dir_entry *dp;
 395         struct dx_root_info *root;
 396         int count_offset;
 397
 398         if (le16_to_cpu(dirent->rec_len) == EXT4_BLOCK_SIZE(inode->i_sb))
 399                 count_offset = 8;
 400         else if (le16_to_cpu(dirent->rec_len) == 12) {
 401                 dp = (struct ext4_dir_entry *)(((void *)dirent) + 12);
 402                 if (le16_to_cpu(dp->rec_len) !=
 403                     EXT4_BLOCK_SIZE(inode->i_sb) - 12)
 404                         return NULL;
 405                 root = (struct dx_root_info *)(((void *)dp + 12));
 406                 if (root->reserved_zero ||
 407                     root->info_length != sizeof(struct dx_root_info))
 408                         return NULL;
 409                 count_offset = 32;
 410         } else
 411                 return NULL;
 412
 413         if (offset)
 414                 *offset = count_offset;
 415         return (struct dx_countlimit *)(((void *)dirent) + count_offset);
 416 }
 417
 418 static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent,
 419                            int count_offset, int count, struct dx_tail *t)
 420 {
 421         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
 422         struct ext4_inode_info *ei = EXT4_I(inode);
 423         __u32 csum;
 424         int size;
 425         __u32 dummy_csum = 0;
 426         int offset = offsetof(struct dx_tail, dt_checksum);
 427
 428         size = count_offset + (count * sizeof(struct dx_entry));
 429         csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
 430         csum = ext4_chksum(sbi, csum, (__u8 *)t, offset);
 431         csum = ext4_chksum(sbi, csum, (__u8 *)&dummy_csum, sizeof(dummy_csum));
 432
 433         return cpu_to_le32(csum);
 434 }
 435
 436 static int ext4_dx_csum_verify(struct inode *inode,
 437                                struct ext4_dir_entry *dirent)
 438 {
 439         struct dx_countlimit *c;
 440         struct dx_tail *t;
 441         int count_offset, limit, count;
 442
 443         if (!ext4_has_metadata_csum(inode->i_sb))
 444                 return 1;
 445
 446         c = get_dx_countlimit(inode, dirent, &count_offset);
 447         if (!c) {
 448                 EXT4_ERROR_INODE(inode, "dir seems corrupt?  Run e2fsck -D.");
 449                 return 1;
 450         }
 451         limit = le16_to_cpu(c->limit);
 452         count = le16_to_cpu(c->count);
 453         if (count_offset + (limit * sizeof(struct dx_entry)) >
 454             EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
 455                 warn_no_space_for_csum(inode);
 456                 return 1;
 457         }
 458         t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
 459
 460         if (t->dt_checksum != ext4_dx_csum(inode, dirent, count_offset,
 461                                             count, t))
 462                 return 0;
 463         return 1;
 464 }
 465
 466 static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent)
 467 {
 468         struct dx_countlimit *c;
 469         struct dx_tail *t;
 470         int count_offset, limit, count;
 471
 472         if (!ext4_has_metadata_csum(inode->i_sb))
 473                 return;
 474
 475         c = get_dx_countlimit(inode, dirent, &count_offset);
 476         if (!c) {
 477                 EXT4_ERROR_INODE(inode, "dir seems corrupt?  Run e2fsck -D.");
 478                 return;
 479         }
 480         limit = le16_to_cpu(c->limit);
 481         count = le16_to_cpu(c->count);
 482         if (count_offset + (limit * sizeof(struct dx_entry)) >
 483             EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
 484                 warn_no_space_for_csum(inode);
 485                 return;
 486         }
 487         t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
 488
 489         t->dt_checksum = ext4_dx_csum(inode, dirent, count_offset, count, t);
 490 }
 491
 492 static inline int ext4_handle_dirty_dx_node(handle_t *handle,
 493                                             struct inode *inode,
 494                                             struct buffer_head *bh)
 495 {
 496         ext4_dx_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
 497         return ext4_handle_dirty_metadata(handle, inode, bh);
 498 }
 499
 500 /*
 501  * p is at least 6 bytes before the end of page
 502  */
 503 static inline struct ext4_dir_entry_2 *
 504 ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
 505 {
 506         return (struct ext4_dir_entry_2 *)((char *)p +
 507                 ext4_rec_len_from_disk(p->rec_len, blocksize));
 508 }
 509
 510 /*
 511  * Future: use high four bits of block for coalesce-on-delete flags
 512  * Mask them off for now.
 513  */
 514
 515 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
 516 {
 517         return le32_to_cpu(entry->block) & 0x00ffffff;
 518 }
 519
 520 static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
 521 {
 522         entry->block = cpu_to_le32(value);
 523 }
 524
 525 static inline unsigned dx_get_hash(struct dx_entry *entry)
 526 {
 527         return le32_to_cpu(entry->hash);
 528 }
 529
 530 static inline void dx_set_hash(struct dx_entry *entry, unsigned value)
 531 {
 532         entry->hash = cpu_to_le32(value);
 533 }
 534
 535 static inline unsigned dx_get_count(struct dx_entry *entries)
 536 {
 537         return le16_to_cpu(((struct dx_countlimit *) entries)->count);
 538 }
 539
 540 static inline unsigned dx_get_limit(struct dx_entry *entries)
 541 {
 542         return le16_to_cpu(((struct dx_countlimit *) entries)->limit);
 543 }
 544
 545 static inline void dx_set_count(struct dx_entry *entries, unsigned value)
 546 {
 547         ((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
 548 }
 549
 550 static inline void dx_set_limit(struct dx_entry *entries, unsigned value)
 551 {
 552         ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
 553 }
 554
 555 static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
 556 {
 557         unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
 558                 EXT4_DIR_REC_LEN(2) - infosize;
 559
 560         if (ext4_has_metadata_csum(dir->i_sb))
 561                 entry_space -= sizeof(struct dx_tail);
 562         return entry_space / sizeof(struct dx_entry);
 563 }
 564
 565 static inline unsigned dx_node_limit(struct inode *dir)
 566 {
 567         unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);
 568
 569         if (ext4_has_metadata_csum(dir->i_sb))
 570                 entry_space -= sizeof(struct dx_tail);
 571         return entry_space / sizeof(struct dx_entry);
 572 }
 573
 574 /*
 575  * Debug
 576  */
 577 #ifdef DX_DEBUG
 578 static void dx_show_index(char * label, struct dx_entry *entries)
 579 {
 580         int i, n = dx_get_count (entries);
 581         printk(KERN_DEBUG "%s index ", label);
 582         for (i = 0; i < n; i++) {
 583                 printk("%x->%lu ", i ? dx_get_hash(entries + i) :
 584                                 0, (unsigned long)dx_get_block(entries + i));
 585         }
 586         printk("\n");
 587 }
 588
 589 struct stats
 590 {
 591         unsigned names;
 592         unsigned space;
 593         unsigned bcount;
 594 };
 595
 596 static struct stats dx_show_leaf(struct inode *dir,
 597                                 struct dx_hash_info *hinfo,
 598                                 struct ext4_dir_entry_2 *de,
 599                                 int size, int show_names)
 600 {
 601         unsigned names = 0, space = 0;
 602         char *base = (char *) de;
 603         struct dx_hash_info h = *hinfo;
 604
 605         printk("names: ");
 606         while ((char *) de < base + size)
 607         {
 608                 if (de->inode)
 609                 {
 610                         if (show_names)
 611                         {
 612 #ifdef CONFIG_EXT4_FS_ENCRYPTION
 613                                 int len;
 614                                 char *name;
 615                                 struct ext4_str fname_crypto_str
 616                                         = {.name = NULL, .len = 0};
 617                                 int res = 0;
 618
 619                                 name  = de->name;
 620                                 len = de->name_len;
 621                                 if (ext4_encrypted_inode(inode))
 622                                         res = ext4_get_encryption_info(dir);
 623                                 if (res) {
 624                                         printk(KERN_WARNING "Error setting up"
 625                                                " fname crypto: %d\n", res);
 626                                 }
 627                                 if (ctx == NULL) {
 628                                         /* Directory is not encrypted */
 629                                         ext4fs_dirhash(de->name,
 630                                                 de->name_len, &h);
 631                                         printk("%*.s:(U)%x.%u ", len,
 632                                                name, h.hash,
 633                                                (unsigned) ((char *) de
 634                                                            - base));
 635                                 } else {
 636                                         /* Directory is encrypted */
 637                                         res = ext4_fname_crypto_alloc_buffer(
 638                                                 ctx, de->name_len,
 639                                                 &fname_crypto_str);
 640                                         if (res < 0) {
 641                                                 printk(KERN_WARNING "Error "
 642                                                         "allocating crypto "
 643                                                         "buffer--skipping "
 644                                                         "crypto\n");
 645                                                 ctx = NULL;
 646                                         }
 647                                         res = ext4_fname_disk_to_usr(ctx, NULL, de,
 648                                                         &fname_crypto_str);
 649                                         if (res < 0) {
 650                                                 printk(KERN_WARNING "Error "
 651                                                         "converting filename "
 652                                                         "from disk to usr"
 653                                                         "\n");
 654                                                 name = "??";
 655                                                 len = 2;
 656                                         } else {
 657                                                 name = fname_crypto_str.name;
 658                                                 len = fname_crypto_str.len;
 659                                         }
 660                                         ext4fs_dirhash(de->name, de->name_len,
 661                                                        &h);
 662                                         printk("%*.s:(E)%x.%u ", len, name,
 663                                                h.hash, (unsigned) ((char *) de
 664                                                                    - base));
 665                                         ext4_fname_crypto_free_buffer(
 666                                                 &fname_crypto_str);
 667                                 }
 668 #else
 669                                 int len = de->name_len;
 670                                 char *name = de->name;
 671                                 ext4fs_dirhash(de->name, de->name_len, &h);
 672                                 printk("%*.s:%x.%u ", len, name, h.hash,
 673                                        (unsigned) ((char *) de - base));
 674 #endif
 675                         }
 676                         space += EXT4_DIR_REC_LEN(de->name_len);
 677                         names++;
 678                 }
 679                 de = ext4_next_entry(de, size);
 680         }
 681         printk("(%i)\n", names);
 682         return (struct stats) { names, space, 1 };
 683 }
 684
 685 struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
 686                              struct dx_entry *entries, int levels)
 687 {
 688         unsigned blocksize = dir->i_sb->s_blocksize;
 689         unsigned count = dx_get_count(entries), names = 0, space = 0, i;
 690         unsigned bcount = 0;
 691         struct buffer_head *bh;
 692         printk("%i indexed blocks...\n", count);
 693         for (i = 0; i < count; i++, entries++)
 694         {
 695                 ext4_lblk_t block = dx_get_block(entries);
 696                 ext4_lblk_t hash  = i ? dx_get_hash(entries): 0;
 697                 u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
 698                 struct stats stats;
 699                 printk("%s%3u:%03u hash %8x/%8x ",levels?"":"   ", i, block, hash, range);
 700                 bh = ext4_bread(NULL,dir, block, 0);
 701                 if (!bh || IS_ERR(bh))
 702                         continue;
 703                 stats = levels?
 704                    dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
 705                    dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *)
 706                         bh->b_data, blocksize, 0);
 707                 names += stats.names;
 708                 space += stats.space;
 709                 bcount += stats.bcount;
 710                 brelse(bh);
 711         }
 712         if (bcount)
 713                 printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n",
 714                        levels ? "" : "   ", names, space/bcount,
 715                        (space/bcount)*100/blocksize);
 716         return (struct stats) { names, space, bcount};
 717 }
 718 #endif /* DX_DEBUG */
 719
 720 /*
 721  * Probe for a directory leaf block to search.
 722  *
 723  * dx_probe can return ERR_BAD_DX_DIR, which means there was a format
 724  * error in the directory index, and the caller should fall back to
 725  * searching the directory normally.  The callers of dx_probe **MUST**
 726  * check for this error code, and make sure it never gets reflected
 727  * back to userspace.
 728  */
 729 static struct dx_frame *
 730 dx_probe(struct ext4_filename *fname, struct inode *dir,
 731          struct dx_hash_info *hinfo, struct dx_frame *frame_in)
 732 {
 733         unsigned count, indirect;
 734         struct dx_entry *at, *entries, *p, *q, *m;
 735         struct dx_root *root;
 736         struct dx_frame *frame = frame_in;
 737         struct dx_frame *ret_err = ERR_PTR(ERR_BAD_DX_DIR);
 738         u32 hash;
 739
 740         frame->bh = ext4_read_dirblock(dir, 0, INDEX);
 741         if (IS_ERR(frame->bh))
 742                 return (struct dx_frame *) frame->bh;
 743
 744         root = (struct dx_root *) frame->bh->b_data;
 745         if (root->info.hash_version != DX_HASH_TEA &&
 746             root->info.hash_version != DX_HASH_HALF_MD4 &&
 747             root->info.hash_version != DX_HASH_LEGACY) {
 748                 ext4_warning_inode(dir, "Unrecognised inode hash code %u",
 749                                    root->info.hash_version);
 750                 goto fail;
 751         }
 752         if (fname)
 753                 hinfo = &fname->hinfo;
 754         hinfo->hash_version = root->info.hash_version;
 755         if (hinfo->hash_version <= DX_HASH_TEA)
 756                 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
 757         hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
 758         if (fname && fname_name(fname))
 759                 ext4fs_dirhash(fname_name(fname), fname_len(fname), hinfo);
 760         hash = hinfo->hash;
 761
 762         if (root->info.unused_flags & 1) {
 763                 ext4_warning_inode(dir, "Unimplemented hash flags: %#06x",
 764                                    root->info.unused_flags);
 765                 goto fail;
 766         }
 767
 768         indirect = root->info.indirect_levels;
 769         if (indirect > 1) {
 770                 ext4_warning_inode(dir, "Unimplemented hash depth: %#06x",
 771                                    root->info.indirect_levels);
 772                 goto fail;
 773         }
 774
 775         entries = (struct dx_entry *)(((char *)&root->info) +
 776                                       root->info.info_length);
 777
 778         if (dx_get_limit(entries) != dx_root_limit(dir,
 779                                                    root->info.info_length)) {
 780                 ext4_warning_inode(dir, "dx entry: limit %u != root limit %u",
 781                                    dx_get_limit(entries),
 782                                    dx_root_limit(dir, root->info.info_length));
 783                 goto fail;
 784         }
 785
 786         dxtrace(printk("Look up %x", hash));
 787         while (1) {
 788                 count = dx_get_count(entries);
 789                 if (!count || count > dx_get_limit(entries)) {
 790                         ext4_warning_inode(dir,
 791                                            "dx entry: count %u beyond limit %u",
 792                                            count, dx_get_limit(entries));
 793                         goto fail;
 794                 }
 795
 796                 p = entries + 1;
 797                 q = entries + count - 1;
 798                 while (p <= q) {
 799                         m = p + (q - p) / 2;
 800                         dxtrace(printk("."));
 801                         if (dx_get_hash(m) > hash)
 802                                 q = m - 1;
 803                         else
 804                                 p = m + 1;
 805                 }
 806
 807                 if (0) { // linear search cross check
 808                         unsigned n = count - 1;
 809                         at = entries;
 810                         while (n--)
 811                         {
 812                                 dxtrace(printk(","));
 813                                 if (dx_get_hash(++at) > hash)
 814                                 {
 815                                         at--;
 816                                         break;
 817                                 }
 818                         }
 819                         assert (at == p - 1);
 820                 }
 821
 822                 at = p - 1;
 823                 dxtrace(printk(" %x->%u\n", at == entries ? 0 : dx_get_hash(at),
 824                                dx_get_block(at)));
 825                 frame->entries = entries;
 826                 frame->at = at;
 827                 if (!indirect--)
 828                         return frame;
 829                 frame++;
 830                 frame->bh = ext4_read_dirblock(dir, dx_get_block(at), INDEX);
 831                 if (IS_ERR(frame->bh)) {
 832                         ret_err = (struct dx_frame *) frame->bh;
 833                         frame->bh = NULL;
 834                         goto fail;
 835                 }
 836                 entries = ((struct dx_node *) frame->bh->b_data)->entries;
 837
 838                 if (dx_get_limit(entries) != dx_node_limit(dir)) {
 839                         ext4_warning_inode(dir,
 840                                 "dx entry: limit %u != node limit %u",
 841                                 dx_get_limit(entries), dx_node_limit(dir));
 842                         goto fail;
 843                 }
 844         }
 845 fail:
 846         while (frame >= frame_in) {
 847                 brelse(frame->bh);
 848                 frame--;
 849         }
 850
 851         if (ret_err == ERR_PTR(ERR_BAD_DX_DIR))
 852                 ext4_warning_inode(dir,
 853                         "Corrupt directory, running e2fsck is recommended");
 854         return ret_err;
 855 }
 856
 857 static void dx_release(struct dx_frame *frames)
 858 {
 859         if (frames[0].bh == NULL)
 860                 return;
 861
 862         if (((struct dx_root *)frames[0].bh->b_data)->info.indirect_levels)
 863                 brelse(frames[1].bh);
 864         brelse(frames[0].bh);
 865 }
 866
 867 /*
 868  * This function increments the frame pointer to search the next leaf
 869  * block, and reads in the necessary intervening nodes if the search
 870  * should be necessary.  Whether or not the search is necessary is
 871  * controlled by the hash parameter.  If the hash value is even, then
 872  * the search is only continued if the next block starts with that
 873  * hash value.  This is used if we are searching for a specific file.
 874  *
 875  * If the hash value is HASH_NB_ALWAYS, then always go to the next block.
 876  *
 877  * This function returns 1 if the caller should continue to search,
 878  * or 0 if it should not.  If there is an error reading one of the
 879  * index blocks, it will a negative error code.
 880  *
 881  * If start_hash is non-null, it will be filled in with the starting
 882  * hash of the next page.
 883  */
 884 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
 885                                  struct dx_frame *frame,
 886                                  struct dx_frame *frames,
 887                                  __u32 *start_hash)
 888 {
 889         struct dx_frame *p;
 890         struct buffer_head *bh;
 891         int num_frames = 0;
 892         __u32 bhash;
 893
 894         p = frame;
 895         /*
 896          * Find the next leaf page by incrementing the frame pointer.
 897          * If we run out of entries in the interior node, loop around and
 898          * increment pointer in the parent node.  When we break out of
 899          * this loop, num_frames indicates the number of interior
 900          * nodes need to be read.
 901          */
 902         while (1) {
 903                 if (++(p->at) < p->entries + dx_get_count(p->entries))
 904                         break;
 905                 if (p == frames)
 906                         return 0;
 907                 num_frames++;
 908                 p--;
 909         }
 910
 911         /*
 912          * If the hash is 1, then continue only if the next page has a
 913          * continuation hash of any value.  This is used for readdir
 914          * handling.  Otherwise, check to see if the hash matches the
 915          * desired contiuation hash.  If it doesn't, return since
 916          * there's no point to read in the successive index pages.
 917          */
 918         bhash = dx_get_hash(p->at);
 919         if (start_hash)
 920                 *start_hash = bhash;
 921         if ((hash & 1) == 0) {
 922                 if ((bhash & ~1) != hash)
 923                         return 0;
 924         }
 925         /*
 926          * If the hash is HASH_NB_ALWAYS, we always go to the next
 927          * block so no check is necessary
 928          */
 929         while (num_frames--) {
 930                 bh = ext4_read_dirblock(dir, dx_get_block(p->at), INDEX);
 931                 if (IS_ERR(bh))
 932                         return PTR_ERR(bh);
 933                 p++;
 934                 brelse(p->bh);
 935                 p->bh = bh;
 936                 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
 937         }
 938         return 1;
 939 }
 940
 941
 942 /*
 943  * This function fills a red-black tree with information from a
 944  * directory block.  It returns the number directory entries loaded
 945  * into the tree.  If there is an error it is returned in err.
 946  */
 947 static int htree_dirblock_to_tree(struct file *dir_file,
 948                                   struct inode *dir, ext4_lblk_t block,
 949                                   struct dx_hash_info *hinfo,
 950                                   __u32 start_hash, __u32 start_minor_hash)
 951 {
 952         struct buffer_head *bh;
 953         struct ext4_dir_entry_2 *de, *top;
 954         int err = 0, count = 0;
 955         struct ext4_str fname_crypto_str = {.name = NULL, .len = 0}, tmp_str;
 956
 957         dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
 958                                                         (unsigned long)block));
 959         bh = ext4_read_dirblock(dir, block, DIRENT);
 960         if (IS_ERR(bh))
 961                 return PTR_ERR(bh);
 962
 963         de = (struct ext4_dir_entry_2 *) bh->b_data;
 964         top = (struct ext4_dir_entry_2 *) ((char *) de +
 965                                            dir->i_sb->s_blocksize -
 966                                            EXT4_DIR_REC_LEN(0));
 967 #ifdef CONFIG_EXT4_FS_ENCRYPTION
 968         /* Check if the directory is encrypted */
 969         if (ext4_encrypted_inode(dir)) {
 970                 err = ext4_get_encryption_info(dir);
 971                 if (err < 0) {
 972                         brelse(bh);
 973                         return err;
 974                 }
 975                 err = ext4_fname_crypto_alloc_buffer(dir, EXT4_NAME_LEN,
 976                                                      &fname_crypto_str);
 977                 if (err < 0) {
 978                         brelse(bh);
 979                         return err;
 980                 }
 981         }
 982 #endif
 983         for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) {
 984                 if (ext4_check_dir_entry(dir, NULL, de, bh,
 985                                 bh->b_data, bh->b_size,
 986                                 (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
 987                                          + ((char *)de - bh->b_data))) {
 988                         /* silently ignore the rest of the block */
 989                         break;
 990                 }
 991                 ext4fs_dirhash(de->name, de->name_len, hinfo);
 992                 if ((hinfo->hash < start_hash) ||
 993                     ((hinfo->hash == start_hash) &&
 994                      (hinfo->minor_hash < start_minor_hash)))
 995                         continue;
 996                 if (de->inode == 0)
 997                         continue;
 998                 if (!ext4_encrypted_inode(dir)) {
 999                         tmp_str.name = de->name;
1000                         tmp_str.len = de->name_len;
1001                         err = ext4_htree_store_dirent(dir_file,
1002                                    hinfo->hash, hinfo->minor_hash, de,
1003                                    &tmp_str);
1004                 } else {
1005                         int save_len = fname_crypto_str.len;
1006
1007                         /* Directory is encrypted */
1008                         err = ext4_fname_disk_to_usr(dir, hinfo, de,
1009                                                      &fname_crypto_str);
1010                         if (err < 0) {
1011                                 count = err;
1012                                 goto errout;
1013                         }
1014                         err = ext4_htree_store_dirent(dir_file,
1015                                    hinfo->hash, hinfo->minor_hash, de,
1016                                         &fname_crypto_str);
1017                         fname_crypto_str.len = save_len;
1018                 }
1019                 if (err != 0) {
1020                         count = err;
1021                         goto errout;
1022                 }
1023                 count++;
1024         }
1025 errout:
1026         brelse(bh);
1027 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1028         ext4_fname_crypto_free_buffer(&fname_crypto_str);
1029 #endif
1030         return count;
1031 }
1032
1033
1034 /*
1035  * This function fills a red-black tree with information from a
1036  * directory.  We start scanning the directory in hash order, starting
1037  * at start_hash and start_minor_hash.
1038  *
1039  * This function returns the number of entries inserted into the tree,
1040  * or a negative error code.
1041  */
1042 int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
1043                          __u32 start_minor_hash, __u32 *next_hash)
1044 {
1045         struct dx_hash_info hinfo;
1046         struct ext4_dir_entry_2 *de;
1047         struct dx_frame frames[2], *frame;
1048         struct inode *dir;
1049         ext4_lblk_t block;
1050         int count = 0;
1051         int ret, err;
1052         __u32 hashval;
1053         struct ext4_str tmp_str;
1054
1055         dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
1056                        start_hash, start_minor_hash));
1057         dir = file_inode(dir_file);
1058         if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) {
1059                 hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
1060                 if (hinfo.hash_version <= DX_HASH_TEA)
1061                         hinfo.hash_version +=
1062                                 EXT4_SB(dir->i_sb)->s_hash_unsigned;
1063                 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
1064                 if (ext4_has_inline_data(dir)) {
1065                         int has_inline_data = 1;
1066                         count = htree_inlinedir_to_tree(dir_file, dir, 0,
1067                                                         &hinfo, start_hash,
1068                                                         start_minor_hash,
1069                                                         &has_inline_data);
1070                         if (has_inline_data) {
1071                                 *next_hash = ~0;
1072                                 return count;
1073                         }
1074                 }
1075                 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
1076                                                start_hash, start_minor_hash);
1077                 *next_hash = ~0;
1078                 return count;
1079         }
1080         hinfo.hash = start_hash;
1081         hinfo.minor_hash = 0;
1082         frame = dx_probe(NULL, dir, &hinfo, frames);
1083         if (IS_ERR(frame))
1084                 return PTR_ERR(frame);
1085
1086         /* Add '.' and '..' from the htree header */
1087         if (!start_hash && !start_minor_hash) {
1088                 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
1089                 tmp_str.name = de->name;
1090                 tmp_str.len = de->name_len;
1091                 err = ext4_htree_store_dirent(dir_file, 0, 0,
1092                                               de, &tmp_str);
1093                 if (err != 0)
1094                         goto errout;
1095                 count++;
1096         }
1097         if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
1098                 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
1099                 de = ext4_next_entry(de, dir->i_sb->s_blocksize);
1100                 tmp_str.name = de->name;
1101                 tmp_str.len = de->name_len;
1102                 err = ext4_htree_store_dirent(dir_file, 2, 0,
1103                                               de, &tmp_str);
1104                 if (err != 0)
1105                         goto errout;
1106                 count++;
1107         }
1108
1109         while (1) {
1110                 block = dx_get_block(frame->at);
1111                 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
1112                                              start_hash, start_minor_hash);
1113                 if (ret < 0) {
1114                         err = ret;
1115                         goto errout;
1116                 }
1117                 count += ret;
1118                 hashval = ~0;
1119                 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
1120                                             frame, frames, &hashval);
1121                 *next_hash = hashval;
1122                 if (ret < 0) {
1123                         err = ret;
1124                         goto errout;
1125                 }
1126                 /*
1127                  * Stop if:  (a) there are no more entries, or
1128                  * (b) we have inserted at least one entry and the
1129                  * next hash value is not a continuation
1130                  */
1131                 if ((ret == 0) ||
1132                     (count && ((hashval & 1) == 0)))
1133                         break;
1134         }
1135         dx_release(frames);
1136         dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, "
1137                        "next hash: %x\n", count, *next_hash));
1138         return count;
1139 errout:
1140         dx_release(frames);
1141         return (err);
1142 }
1143
1144 static inline int search_dirblock(struct buffer_head *bh,
1145                                   struct inode *dir,
1146                                   struct ext4_filename *fname,
1147                                   const struct qstr *d_name,
1148                                   unsigned int offset,
1149                                   struct ext4_dir_entry_2 **res_dir)
1150 {
1151         return ext4_search_dir(bh, bh->b_data, dir->i_sb->s_blocksize, dir,
1152                                fname, d_name, offset, res_dir);
1153 }
1154
1155 /*
1156  * Directory block splitting, compacting
1157  */
1158
1159 /*
1160  * Create map of hash values, offsets, and sizes, stored at end of block.
1161  * Returns number of entries mapped.
1162  */
1163 static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de,
1164                        unsigned blocksize, struct dx_hash_info *hinfo,
1165                        struct dx_map_entry *map_tail)
1166 {
1167         int count = 0;
1168         char *base = (char *) de;
1169         struct dx_hash_info h = *hinfo;
1170
1171         while ((char *) de < base + blocksize) {
1172                 if (de->name_len && de->inode) {
1173                         ext4fs_dirhash(de->name, de->name_len, &h);
1174                         map_tail--;
1175                         map_tail->hash = h.hash;
1176                         map_tail->offs = ((char *) de - base)>>2;
1177                         map_tail->size = le16_to_cpu(de->rec_len);
1178                         count++;
1179                         cond_resched();
1180                 }
1181                 /* XXX: do we need to check rec_len == 0 case? -Chris */
1182                 de = ext4_next_entry(de, blocksize);
1183         }
1184         return count;
1185 }
1186
1187 /* Sort map by hash value */
1188 static void dx_sort_map (struct dx_map_entry *map, unsigned count)
1189 {
1190         struct dx_map_entry *p, *q, *top = map + count - 1;
1191         int more;
1192         /* Combsort until bubble sort doesn't suck */
1193         while (count > 2) {
1194                 count = count*10/13;
1195                 if (count - 9 < 2) /* 9, 10 -> 11 */
1196                         count = 11;
1197                 for (p = top, q = p - count; q >= map; p--, q--)
1198                         if (p->hash < q->hash)
1199                                 swap(*p, *q);
1200         }
1201         /* Garden variety bubble sort */
1202         do {
1203                 more = 0;
1204                 q = top;
1205                 while (q-- > map) {
1206                         if (q[1].hash >= q[0].hash)
1207                                 continue;
1208                         swap(*(q+1), *q);
1209                         more = 1;
1210                 }
1211         } while(more);
1212 }
1213
1214 static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
1215 {
1216         struct dx_entry *entries = frame->entries;
1217         struct dx_entry *old = frame->at, *new = old + 1;
1218         int count = dx_get_count(entries);
1219
1220         assert(count < dx_get_limit(entries));
1221         assert(old < entries + count);
1222         memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
1223         dx_set_hash(new, hash);
1224         dx_set_block(new, block);
1225         dx_set_count(entries, count + 1);
1226 }
1227
1228 /*
1229  * Test whether a directory entry matches the filename being searched for.
1230  *
1231  * Return: %true if the directory entry matches, otherwise %false.
1232  */
1233 static inline bool ext4_match(const struct ext4_filename *fname,
1234                               const struct ext4_dir_entry_2 *de)
1235 {
1236         const void *name = fname_name(fname);
1237         u32 len = fname_len(fname);
1238
1239         if (!de->inode)
1240                 return false;
1241
1242 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1243         if (unlikely(!name)) {
1244                 if (fname->usr_fname->name[0] == '_') {
1245                         int ret;
1246                         if (de->name_len <= 32)
1247                                 return 0;
1248                         ret = memcmp(de->name + ((de->name_len - 17) & ~15),
1249                                      fname->crypto_buf.name + 8, 16);
1250                         return (ret == 0) ? 1 : 0;
1251                 }
1252                 name = fname->crypto_buf.name;
1253                 len = fname->crypto_buf.len;
1254         }
1255 #endif
1256         if (de->name_len != len)
1257                 return 0;
1258         return (memcmp(de->name, name, len) == 0) ? 1 : 0;
1259 }
1260
1261 /*
1262  * Returns 0 if not found, -1 on failure, and 1 on success
1263  */
1264 int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size,
1265                     struct inode *dir, struct ext4_filename *fname,
1266                     const struct qstr *d_name,
1267                     unsigned int offset, struct ext4_dir_entry_2 **res_dir)
1268 {
1269         struct ext4_dir_entry_2 * de;
1270         char * dlimit;
1271         int de_len;
1272
1273         de = (struct ext4_dir_entry_2 *)search_buf;
1274         dlimit = search_buf + buf_size;
1275         while ((char *) de < dlimit) {
1276                 /* this code is executed quadratically often */
1277                 /* do minimal checking `by hand' */
1278                 if ((char *) de + de->name_len <= dlimit &&
1279                     ext4_match(fname, de)) {
1280                         /* found a match - just to be sure, do
1281                          * a full check */
1282                         if (ext4_check_dir_entry(dir, NULL, de, bh, search_buf,
1283                                                  buf_size, offset))
1284                                 return -1;
1285                         *res_dir = de;
1286                         return 1;
1287                 }
1288                 /* prevent looping on a bad block */
1289                 de_len = ext4_rec_len_from_disk(de->rec_len,
1290                                                 dir->i_sb->s_blocksize);
1291                 if (de_len <= 0)
1292                         return -1;
1293                 offset += de_len;
1294                 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
1295         }
1296         return 0;
1297 }
1298
1299 static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block,
1300                                struct ext4_dir_entry *de)
1301 {
1302         struct super_block *sb = dir->i_sb;
1303
1304         if (!is_dx(dir))
1305                 return 0;
1306         if (block == 0)
1307                 return 1;
1308         if (de->inode == 0 &&
1309             ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) ==
1310                         sb->s_blocksize)
1311                 return 1;
1312         return 0;
1313 }
1314
1315 /*
1316  *      ext4_find_entry()
1317  *
1318  * finds an entry in the specified directory with the wanted name. It
1319  * returns the cache buffer in which the entry was found, and the entry
1320  * itself (as a parameter - res_dir). It does NOT read the inode of the
1321  * entry - you'll have to do that yourself if you want to.
1322  *
1323  * The returned buffer_head has ->b_count elevated.  The caller is expected
1324  * to brelse() it when appropriate.
1325  */
1326 static struct buffer_head * ext4_find_entry (struct inode *dir,
1327                                         const struct qstr *d_name,
1328                                         struct ext4_dir_entry_2 **res_dir,
1329                                         int *inlined)
1330 {
1331         struct super_block *sb;
1332         struct buffer_head *bh_use[NAMEI_RA_SIZE];
1333         struct buffer_head *bh, *ret = NULL;
1334         ext4_lblk_t start, block, b;
1335         const u8 *name = d_name->name;
1336         int ra_max = 0;         /* Number of bh's in the readahead
1337                                    buffer, bh_use[] */
1338         int ra_ptr = 0;         /* Current index into readahead
1339                                    buffer */
1340         int num = 0;
1341         ext4_lblk_t  nblocks;
1342         int i, namelen, retval;
1343         struct ext4_filename fname;
1344
1345         *res_dir = NULL;
1346         sb = dir->i_sb;
1347         namelen = d_name->len;
1348         if (namelen > EXT4_NAME_LEN)
1349                 return NULL;
1350
1351         retval = ext4_fname_setup_filename(dir, d_name, 1, &fname);
1352         if (retval)
1353                 return ERR_PTR(retval);
1354
1355         if (ext4_has_inline_data(dir)) {
1356                 int has_inline_data = 1;
1357                 ret = ext4_find_inline_entry(dir, &fname, d_name, res_dir,
1358                                              &has_inline_data);
1359                 if (has_inline_data) {
1360                         if (inlined)
1361                                 *inlined = 1;
1362                         goto cleanup_and_exit;
1363                 }
1364         }
1365
1366         if ((namelen <= 2) && (name[0] == '.') &&
1367             (name[1] == '.' || name[1] == '\0')) {
1368                 /*
1369                  * "." or ".." will only be in the first block
1370                  * NFS may look up ".."; "." should be handled by the VFS
1371                  */
1372                 block = start = 0;
1373                 nblocks = 1;
1374                 goto restart;
1375         }
1376         if (is_dx(dir)) {
1377                 ret = ext4_dx_find_entry(dir, &fname, res_dir);
1378                 /*
1379                  * On success, or if the error was file not found,
1380                  * return.  Otherwise, fall back to doing a search the
1381                  * old fashioned way.
1382                  */
1383                 if (!IS_ERR(ret) || PTR_ERR(ret) != ERR_BAD_DX_DIR)
1384                         goto cleanup_and_exit;
1385                 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
1386                                "falling back\n"));
1387                 ret = NULL;
1388         }
1389         nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1390         if (!nblocks) {
1391                 ret = NULL;
1392                 goto cleanup_and_exit;
1393         }
1394         start = EXT4_I(dir)->i_dir_start_lookup;
1395         if (start >= nblocks)
1396                 start = 0;
1397         block = start;
1398 restart:
1399         do {
1400                 /*
1401                  * We deal with the read-ahead logic here.
1402                  */
1403                 cond_resched();
1404                 if (ra_ptr >= ra_max) {
1405                         /* Refill the readahead buffer */
1406                         ra_ptr = 0;
1407                         b = block;
1408                         for (ra_max = 0; ra_max < NAMEI_RA_SIZE; ra_max++) {
1409                                 /*
1410                                  * Terminate if we reach the end of the
1411                                  * directory and must wrap, or if our
1412                                  * search has finished at this block.
1413                                  */
1414                                 if (b >= nblocks || (num && block == start)) {
1415                                         bh_use[ra_max] = NULL;
1416                                         break;
1417                                 }
1418                                 num++;
1419                                 bh = ext4_getblk(NULL, dir, b++, 0);
1420                                 if (IS_ERR(bh)) {
1421                                         if (ra_max == 0) {
1422                                                 ret = bh;
1423                                                 goto cleanup_and_exit;
1424                                         }
1425                                         break;
1426                                 }
1427                                 bh_use[ra_max] = bh;
1428                                 if (bh)
1429                                         ll_rw_block(READ | REQ_META | REQ_PRIO,
1430                                                     1, &bh);
1431                         }
1432                 }
1433                 if ((bh = bh_use[ra_ptr++]) == NULL)
1434                         goto next;
1435                 wait_on_buffer(bh);
1436                 if (!buffer_uptodate(bh)) {
1437                         /* read error, skip block & hope for the best */
1438                         EXT4_ERROR_INODE(dir, "reading directory lblock %lu",
1439                                          (unsigned long) block);
1440                         brelse(bh);
1441                         goto next;
1442                 }
1443                 if (!buffer_verified(bh) &&
1444                     !is_dx_internal_node(dir, block,
1445                                          (struct ext4_dir_entry *)bh->b_data) &&
1446                     !ext4_dirent_csum_verify(dir,
1447                                 (struct ext4_dir_entry *)bh->b_data)) {
1448                         EXT4_ERROR_INODE(dir, "checksumming directory "
1449                                          "block %lu", (unsigned long)block);
1450                         brelse(bh);
1451                         goto next;
1452                 }
1453                 set_buffer_verified(bh);
1454                 i = search_dirblock(bh, dir, &fname, d_name,
1455                             block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
1456                 if (i == 1) {
1457                         EXT4_I(dir)->i_dir_start_lookup = block;
1458                         ret = bh;
1459                         goto cleanup_and_exit;
1460                 } else {
1461                         brelse(bh);
1462                         if (i < 0)
1463                                 goto cleanup_and_exit;
1464                 }
1465         next:
1466                 if (++block >= nblocks)
1467                         block = 0;
1468         } while (block != start);
1469
1470         /*
1471          * If the directory has grown while we were searching, then
1472          * search the last part of the directory before giving up.
1473          */
1474         block = nblocks;
1475         nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1476         if (block < nblocks) {
1477                 start = 0;
1478                 goto restart;
1479         }
1480
1481 cleanup_and_exit:
1482         /* Clean up the read-ahead blocks */
1483         for (; ra_ptr < ra_max; ra_ptr++)
1484                 brelse(bh_use[ra_ptr]);
1485         ext4_fname_free_filename(&fname);
1486         return ret;
1487 }
1488
1489 static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
1490                         struct ext4_filename *fname,
1491                         struct ext4_dir_entry_2 **res_dir)
1492 {
1493         struct super_block * sb = dir->i_sb;
1494         struct dx_frame frames[2], *frame;
1495         const struct qstr *d_name = fname->usr_fname;
1496         struct buffer_head *bh;
1497         ext4_lblk_t block;
1498         int retval;
1499
1500 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1501         *res_dir = NULL;
1502 #endif
1503         frame = dx_probe(fname, dir, NULL, frames);
1504         if (IS_ERR(frame))
1505                 return (struct buffer_head *) frame;
1506         do {
1507                 block = dx_get_block(frame->at);
1508                 bh = ext4_read_dirblock(dir, block, DIRENT);
1509                 if (IS_ERR(bh))
1510                         goto errout;
1511
1512                 retval = search_dirblock(bh, dir, fname, d_name,
1513                                          block << EXT4_BLOCK_SIZE_BITS(sb),
1514                                          res_dir);
1515                 if (retval == 1)
1516                         goto success;
1517                 brelse(bh);
1518                 if (retval == -1) {
1519                         bh = ERR_PTR(ERR_BAD_DX_DIR);
1520                         goto errout;
1521                 }
1522
1523                 /* Check to see if we should continue to search */
1524                 retval = ext4_htree_next_block(dir, fname->hinfo.hash, frame,
1525                                                frames, NULL);
1526                 if (retval < 0) {
1527                         ext4_warning_inode(dir,
1528                                 "error %d reading directory index block",
1529                                 retval);
1530                         bh = ERR_PTR(retval);
1531                         goto errout;
1532                 }
1533         } while (retval == 1);
1534
1535         bh = NULL;
1536 errout:
1537         dxtrace(printk(KERN_DEBUG "%s not found\n", d_name->name));
1538 success:
1539         dx_release(frames);
1540         return bh;
1541 }
1542
1543 static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
1544 {
1545         struct inode *inode;
1546         struct ext4_dir_entry_2 *de;
1547         struct buffer_head *bh;
1548
1549        if (ext4_encrypted_inode(dir)) {
1550                int res = ext4_get_encryption_info(dir);
1551
1552                 /*
1553                  * This should be a properly defined flag for
1554                  * dentry->d_flags when we uplift this to the VFS.
1555                  * d_fsdata is set to (void *) 1 if if the dentry is
1556                  * created while the directory was encrypted and we
1557                  * don't have access to the key.
1558                  */
1559                dentry->d_fsdata = NULL;
1560                if (ext4_encryption_info(dir))
1561                        dentry->d_fsdata = (void *) 1;
1562                d_set_d_op(dentry, &ext4_encrypted_d_ops);
1563                if (res && res != -ENOKEY)
1564                        return ERR_PTR(res);
1565        }
1566
1567         if (dentry->d_name.len > EXT4_NAME_LEN)
1568                 return ERR_PTR(-ENAMETOOLONG);
1569
1570         bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
1571         if (IS_ERR(bh))
1572                 return (struct dentry *) bh;
1573         inode = NULL;
1574         if (bh) {
1575                 __u32 ino = le32_to_cpu(de->inode);
1576                 brelse(bh);
1577                 if (!ext4_valid_inum(dir->i_sb, ino)) {
1578                         EXT4_ERROR_INODE(dir, "bad inode number: %u", ino);
1579                         return ERR_PTR(-EFSCORRUPTED);
1580                 }
1581                 if (unlikely(ino == dir->i_ino)) {
1582                         EXT4_ERROR_INODE(dir, "'%pd' linked to parent dir",
1583                                          dentry);
1584                         return ERR_PTR(-EFSCORRUPTED);
1585                 }
1586                 inode = ext4_iget(dir->i_sb, ino, EXT4_IGET_NORMAL);
1587                 if (inode == ERR_PTR(-ESTALE)) {
1588                         EXT4_ERROR_INODE(dir,
1589                                          "deleted inode referenced: %u",
1590                                          ino);
1591                         return ERR_PTR(-EFSCORRUPTED);
1592                 }
1593                 if (!IS_ERR(inode) && ext4_encrypted_inode(dir) &&
1594                     (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
1595                      S_ISLNK(inode->i_mode)) &&
1596                     !ext4_is_child_context_consistent_with_parent(dir,
1597                                                                   inode)) {
1598                         iput(inode);
1599                         ext4_warning(inode->i_sb,
1600                                      "Inconsistent encryption contexts: %lu/%lu\n",
1601                                      (unsigned long) dir->i_ino,
1602                                      (unsigned long) inode->i_ino);
1603                         return ERR_PTR(-EPERM);
1604                 }
1605         }
1606         return d_splice_alias(inode, dentry);
1607 }
1608
1609
1610 struct dentry *ext4_get_parent(struct dentry *child)
1611 {
1612         __u32 ino;
1613         static const struct qstr dotdot = QSTR_INIT("..", 2);
1614         struct ext4_dir_entry_2 * de;
1615         struct buffer_head *bh;
1616
1617         bh = ext4_find_entry(d_inode(child), &dotdot, &de, NULL);
1618         if (IS_ERR(bh))
1619                 return (struct dentry *) bh;
1620         if (!bh)
1621                 return ERR_PTR(-ENOENT);
1622         ino = le32_to_cpu(de->inode);
1623         brelse(bh);
1624
1625         if (!ext4_valid_inum(d_inode(child)->i_sb, ino)) {
1626                 EXT4_ERROR_INODE(d_inode(child),
1627                                  "bad parent inode number: %u", ino);
1628                 return ERR_PTR(-EFSCORRUPTED);
1629         }
1630
1631         return d_obtain_alias(ext4_iget(d_inode(child)->i_sb, ino, EXT4_IGET_NORMAL));
1632 }
1633
1634 /*
1635  * Move count entries from end of map between two memory locations.
1636  * Returns pointer to last entry moved.
1637  */
1638 static struct ext4_dir_entry_2 *
1639 dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count,
1640                 unsigned blocksize)
1641 {
1642         unsigned rec_len = 0;
1643
1644         while (count--) {
1645                 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
1646                                                 (from + (map->offs<<2));
1647                 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1648                 memcpy (to, de, rec_len);
1649                 ((struct ext4_dir_entry_2 *) to)->rec_len =
1650                                 ext4_rec_len_to_disk(rec_len, blocksize);
1651                 de->inode = 0;
1652                 map++;
1653                 to += rec_len;
1654         }
1655         return (struct ext4_dir_entry_2 *) (to - rec_len);
1656 }
1657
1658 /*
1659  * Compact each dir entry in the range to the minimal rec_len.
1660  * Returns pointer to last entry in range.
1661  */
1662 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize)
1663 {
1664         struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
1665         unsigned rec_len = 0;
1666
1667         prev = to = de;
1668         while ((char*)de < base + blocksize) {
1669                 next = ext4_next_entry(de, blocksize);
1670                 if (de->inode && de->name_len) {
1671                         rec_len = EXT4_DIR_REC_LEN(de->name_len);
1672                         if (de > to)
1673                                 memmove(to, de, rec_len);
1674                         to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
1675                         prev = to;
1676                         to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
1677                 }
1678                 de = next;
1679         }
1680         return prev;
1681 }
1682
1683 /*
1684  * Split a full leaf block to make room for a new dir entry.
1685  * Allocate a new block, and move entries so that they are approx. equally full.
1686  * Returns pointer to de in block into which the new entry will be inserted.
1687  */
1688 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
1689                         struct buffer_head **bh,struct dx_frame *frame,
1690                         struct dx_hash_info *hinfo)
1691 {
1692         unsigned blocksize = dir->i_sb->s_blocksize;
1693         unsigned count, continued;
1694         struct buffer_head *bh2;
1695         ext4_lblk_t newblock;
1696         u32 hash2;
1697         struct dx_map_entry *map;
1698         char *data1 = (*bh)->b_data, *data2;
1699         unsigned split, move, size;
1700         struct ext4_dir_entry_2 *de = NULL, *de2;
1701         struct ext4_dir_entry_tail *t;
1702         int     csum_size = 0;
1703         int     err = 0, i;
1704
1705         if (ext4_has_metadata_csum(dir->i_sb))
1706                 csum_size = sizeof(struct ext4_dir_entry_tail);
1707
1708         bh2 = ext4_append(handle, dir, &newblock);
1709         if (IS_ERR(bh2)) {
1710                 brelse(*bh);
1711                 *bh = NULL;
1712                 return (struct ext4_dir_entry_2 *) bh2;
1713         }
1714
1715         BUFFER_TRACE(*bh, "get_write_access");
1716         err = ext4_journal_get_write_access(handle, *bh);
1717         if (err)
1718                 goto journal_error;
1719
1720         BUFFER_TRACE(frame->bh, "get_write_access");
1721         err = ext4_journal_get_write_access(handle, frame->bh);
1722         if (err)
1723                 goto journal_error;
1724
1725         data2 = bh2->b_data;
1726
1727         /* create map in the end of data2 block */
1728         map = (struct dx_map_entry *) (data2 + blocksize);
1729         count = dx_make_map(dir, (struct ext4_dir_entry_2 *) data1,
1730                              blocksize, hinfo, map);
1731         map -= count;
1732         dx_sort_map(map, count);
1733         /* Ensure that neither split block is over half full */
1734         size = 0;
1735         move = 0;
1736         for (i = count-1; i >= 0; i--) {
1737                 /* is more than half of this entry in 2nd half of the block? */
1738                 if (size + map[i].size/2 > blocksize/2)
1739                         break;
1740                 size += map[i].size;
1741                 move++;
1742         }
1743         /*
1744          * map index at which we will split
1745          *
1746          * If the sum of active entries didn't exceed half the block size, just
1747          * split it in half by count; each resulting block will have at least
1748          * half the space free.
1749          */
1750         if (i > 0)
1751                 split = count - move;
1752         else
1753                 split = count/2;
1754
1755         hash2 = map[split].hash;
1756         continued = hash2 == map[split - 1].hash;
1757         dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
1758                         (unsigned long)dx_get_block(frame->at),
1759                                         hash2, split, count-split));
1760
1761         /* Fancy dance to stay within two buffers */
1762         de2 = dx_move_dirents(data1, data2, map + split, count - split,
1763                               blocksize);
1764         de = dx_pack_dirents(data1, blocksize);
1765         de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
1766                                            (char *) de,
1767                                            blocksize);
1768         de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
1769                                             (char *) de2,
1770                                             blocksize);
1771         if (csum_size) {
1772                 t = EXT4_DIRENT_TAIL(data2, blocksize);
1773                 initialize_dirent_tail(t, blocksize);
1774
1775                 t = EXT4_DIRENT_TAIL(data1, blocksize);
1776                 initialize_dirent_tail(t, blocksize);
1777         }
1778
1779         dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data1,
1780                         blocksize, 1));
1781         dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data2,
1782                         blocksize, 1));
1783
1784         /* Which block gets the new entry? */
1785         if (hinfo->hash >= hash2) {
1786                 swap(*bh, bh2);
1787                 de = de2;
1788         }
1789         dx_insert_block(frame, hash2 + continued, newblock);
1790         err = ext4_handle_dirty_dirent_node(handle, dir, bh2);
1791         if (err)
1792                 goto journal_error;
1793         err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
1794         if (err)
1795                 goto journal_error;
1796         brelse(bh2);
1797         dxtrace(dx_show_index("frame", frame->entries));
1798         return de;
1799
1800 journal_error:
1801         brelse(*bh);
1802         brelse(bh2);
1803         *bh = NULL;
1804         ext4_std_error(dir->i_sb, err);
1805         return ERR_PTR(err);
1806 }
1807
1808 int ext4_find_dest_de(struct inode *dir, struct inode *inode,
1809                       struct buffer_head *bh,
1810                       void *buf, int buf_size,
1811                       struct ext4_filename *fname,
1812                       struct ext4_dir_entry_2 **dest_de)
1813 {
1814         struct ext4_dir_entry_2 *de;
1815         unsigned short reclen = EXT4_DIR_REC_LEN(fname_len(fname));
1816         int nlen, rlen;
1817         unsigned int offset = 0;
1818         char *top;
1819
1820         de = (struct ext4_dir_entry_2 *)buf;
1821         top = buf + buf_size - reclen;
1822         while ((char *) de <= top) {
1823                 if (ext4_check_dir_entry(dir, NULL, de, bh,
1824                                          buf, buf_size, offset))
1825                         return -EFSCORRUPTED;
1826                 if (ext4_match(fname, de))
1827                         return -EEXIST;
1828                 nlen = EXT4_DIR_REC_LEN(de->name_len);
1829                 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
1830                 if ((de->inode ? rlen - nlen : rlen) >= reclen)
1831                         break;
1832                 de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
1833                 offset += rlen;
1834         }
1835         if ((char *) de > top)
1836                 return -ENOSPC;
1837
1838         *dest_de = de;
1839         return 0;
1840 }
1841
1842 int ext4_insert_dentry(struct inode *dir,
1843                        struct inode *inode,
1844                        struct ext4_dir_entry_2 *de,
1845                        int buf_size,
1846                        struct ext4_filename *fname)
1847 {
1848
1849         int nlen, rlen;
1850
1851         nlen = EXT4_DIR_REC_LEN(de->name_len);
1852         rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
1853         if (de->inode) {
1854                 struct ext4_dir_entry_2 *de1 =
1855                         (struct ext4_dir_entry_2 *)((char *)de + nlen);
1856                 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, buf_size);
1857                 de->rec_len = ext4_rec_len_to_disk(nlen, buf_size);
1858                 de = de1;
1859         }
1860         de->file_type = EXT4_FT_UNKNOWN;
1861         de->inode = cpu_to_le32(inode->i_ino);
1862         ext4_set_de_type(inode->i_sb, de, inode->i_mode);
1863         de->name_len = fname_len(fname);
1864         memcpy(de->name, fname_name(fname), fname_len(fname));
1865         return 0;
1866 }
1867
1868 /*
1869  * Add a new entry into a directory (leaf) block.  If de is non-NULL,
1870  * it points to a directory entry which is guaranteed to be large
1871  * enough for new directory entry.  If de is NULL, then
1872  * add_dirent_to_buf will attempt search the directory block for
1873  * space.  It will return -ENOSPC if no space is available, and -EIO
1874  * and -EEXIST if directory entry already exists.
1875  */
1876 static int add_dirent_to_buf(handle_t *handle, struct ext4_filename *fname,
1877                              struct inode *dir,
1878                              struct inode *inode, struct ext4_dir_entry_2 *de,
1879                              struct buffer_head *bh)
1880 {
1881         unsigned int    blocksize = dir->i_sb->s_blocksize;
1882         int             csum_size = 0;
1883         int             err;
1884
1885         if (ext4_has_metadata_csum(inode->i_sb))
1886                 csum_size = sizeof(struct ext4_dir_entry_tail);
1887
1888         if (!de) {
1889                 err = ext4_find_dest_de(dir, inode, bh, bh->b_data,
1890                                         blocksize - csum_size, fname, &de);
1891                 if (err)
1892                         return err;
1893         }
1894         BUFFER_TRACE(bh, "get_write_access");
1895         err = ext4_journal_get_write_access(handle, bh);
1896         if (err) {
1897                 ext4_std_error(dir->i_sb, err);
1898                 return err;
1899         }
1900
1901         /* By now the buffer is marked for journaling. Due to crypto operations,
1902          * the following function call may fail */
1903         err = ext4_insert_dentry(dir, inode, de, blocksize, fname);
1904         if (err < 0)
1905                 return err;
1906
1907         /*
1908          * XXX shouldn't update any times until successful
1909          * completion of syscall, but too many callers depend
1910          * on this.
1911          *
1912          * XXX similarly, too many callers depend on
1913          * ext4_new_inode() setting the times, but error
1914          * recovery deletes the inode, so the worst that can
1915          * happen is that the times are slightly out of date
1916          * and/or different from the directory change time.
1917          */
1918         dir->i_mtime = dir->i_ctime = ext4_current_time(dir);
1919         ext4_update_dx_flag(dir);
1920         dir->i_version++;
1921         ext4_mark_inode_dirty(handle, dir);
1922         BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1923         err = ext4_handle_dirty_dirent_node(handle, dir, bh);
1924         if (err)
1925                 ext4_std_error(dir->i_sb, err);
1926         return 0;
1927 }
1928
1929 /*
1930  * This converts a one block unindexed directory to a 3 block indexed
1931  * directory, and adds the dentry to the indexed directory.
1932  */
1933 static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname,
1934                             struct dentry *dentry,
1935                             struct inode *inode, struct buffer_head *bh)
1936 {
1937         struct inode    *dir = d_inode(dentry->d_parent);
1938         struct buffer_head *bh2;
1939         struct dx_root  *root;
1940         struct dx_frame frames[2], *frame;
1941         struct dx_entry *entries;
1942         struct ext4_dir_entry_2 *de, *de2;
1943         struct ext4_dir_entry_tail *t;
1944         char            *data1, *top;
1945         unsigned        len;
1946         int             retval;
1947         unsigned        blocksize;
1948         ext4_lblk_t  block;
1949         struct fake_dirent *fde;
1950         int csum_size = 0;
1951
1952         if (ext4_has_metadata_csum(inode->i_sb))
1953                 csum_size = sizeof(struct ext4_dir_entry_tail);
1954
1955         blocksize =  dir->i_sb->s_blocksize;
1956         dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
1957         BUFFER_TRACE(bh, "get_write_access");
1958         retval = ext4_journal_get_write_access(handle, bh);
1959         if (retval) {
1960                 ext4_std_error(dir->i_sb, retval);
1961                 brelse(bh);
1962                 return retval;
1963         }
1964         root = (struct dx_root *) bh->b_data;
1965
1966         /* The 0th block becomes the root, move the dirents out */
1967         fde = &root->dotdot;
1968         de = (struct ext4_dir_entry_2 *)((char *)fde +
1969                 ext4_rec_len_from_disk(fde->rec_len, blocksize));
1970         if ((char *) de >= (((char *) root) + blocksize)) {
1971                 EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
1972                 brelse(bh);
1973                 return -EFSCORRUPTED;
1974         }
1975         len = ((char *) root) + (blocksize - csum_size) - (char *) de;
1976
1977         /* Allocate new block for the 0th block's dirents */
1978         bh2 = ext4_append(handle, dir, &block);
1979         if (IS_ERR(bh2)) {
1980                 brelse(bh);
1981                 return PTR_ERR(bh2);
1982         }
1983         ext4_set_inode_flag(dir, EXT4_INODE_INDEX);
1984         data1 = bh2->b_data;
1985
1986         memcpy (data1, de, len);
1987         de = (struct ext4_dir_entry_2 *) data1;
1988         top = data1 + len;
1989         while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
1990                 de = de2;
1991         de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
1992                                            (char *) de,
1993                                            blocksize);
1994
1995         if (csum_size) {
1996                 t = EXT4_DIRENT_TAIL(data1, blocksize);
1997                 initialize_dirent_tail(t, blocksize);
1998         }
1999
2000         /* Initialize the root; the dot dirents already exist */
2001         de = (struct ext4_dir_entry_2 *) (&root->dotdot);
2002         de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
2003                                            blocksize);
2004         memset (&root->info, 0, sizeof(root->info));
2005         root->info.info_length = sizeof(root->info);
2006         root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
2007         entries = root->entries;
2008         dx_set_block(entries, 1);
2009         dx_set_count(entries, 1);
2010         dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
2011
2012         /* Initialize as for dx_probe */
2013         fname->hinfo.hash_version = root->info.hash_version;
2014         if (fname->hinfo.hash_version <= DX_HASH_TEA)
2015                 fname->hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
2016         fname->hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
2017         ext4fs_dirhash(fname_name(fname), fname_len(fname), &fname->hinfo);
2018
2019         memset(frames, 0, sizeof(frames));
2020         frame = frames;
2021         frame->entries = entries;
2022         frame->at = entries;
2023         frame->bh = bh;
2024
2025         retval = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
2026         if (retval)
2027                 goto out_frames;
2028         retval = ext4_handle_dirty_dirent_node(handle, dir, bh2);
2029         if (retval)
2030                 goto out_frames;
2031
2032         de = do_split(handle,dir, &bh2, frame, &fname->hinfo);
2033         if (IS_ERR(de)) {
2034                 retval = PTR_ERR(de);
2035                 goto out_frames;
2036         }
2037
2038         retval = add_dirent_to_buf(handle, fname, dir, inode, de, bh2);
2039 out_frames:
2040         /*
2041          * Even if the block split failed, we have to properly write
2042          * out all the changes we did so far. Otherwise we can end up
2043          * with corrupted filesystem.
2044          */
2045         if (retval)
2046                 ext4_mark_inode_dirty(handle, dir);
2047         dx_release(frames);
2048         brelse(bh2);
2049         return retval;
2050 }
2051
2052 /*
2053  *      ext4_add_entry()
2054  *
2055  * adds a file entry to the specified directory, using the same
2056  * semantics as ext4_find_entry(). It returns NULL if it failed.
2057  *
2058  * NOTE!! The inode part of 'de' is left at 0 - which means you
2059  * may not sleep between calling this and putting something into
2060  * the entry, as someone else might have used it while you slept.
2061  */
2062 static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
2063                           struct inode *inode)
2064 {
2065         struct inode *dir = d_inode(dentry->d_parent);
2066         struct buffer_head *bh = NULL;
2067         struct ext4_dir_entry_2 *de;
2068         struct ext4_dir_entry_tail *t;
2069         struct super_block *sb;
2070         struct ext4_filename fname;
2071         int     retval;
2072         int     dx_fallback=0;
2073         unsigned blocksize;
2074         ext4_lblk_t block, blocks;
2075         int     csum_size = 0;
2076
2077         if (ext4_has_metadata_csum(inode->i_sb))
2078                 csum_size = sizeof(struct ext4_dir_entry_tail);
2079
2080         sb = dir->i_sb;
2081         blocksize = sb->s_blocksize;
2082         if (!dentry->d_name.len)
2083                 return -EINVAL;
2084
2085         retval = ext4_fname_setup_filename(dir, &dentry->d_name, 0, &fname);
2086         if (retval)
2087                 return retval;
2088
2089         if (ext4_has_inline_data(dir)) {
2090                 retval = ext4_try_add_inline_entry(handle, &fname,
2091                                                    dentry, inode);
2092                 if (retval < 0)
2093                         goto out;
2094                 if (retval == 1) {
2095                         retval = 0;
2096                         goto out;
2097                 }
2098         }
2099
2100         if (is_dx(dir)) {
2101                 retval = ext4_dx_add_entry(handle, &fname, dentry, inode);
2102                 if (!retval || (retval != ERR_BAD_DX_DIR))
2103                         goto out;
2104                 /* Can we just ignore htree data? */
2105                 if (ext4_has_metadata_csum(sb)) {
2106                         EXT4_ERROR_INODE(dir,
2107                                 "Directory has corrupted htree index.");
2108                         retval = -EFSCORRUPTED;
2109                         goto out;
2110                 }
2111                 ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
2112                 dx_fallback++;
2113                 ext4_mark_inode_dirty(handle, dir);
2114         }
2115         blocks = dir->i_size >> sb->s_blocksize_bits;
2116         for (block = 0; block < blocks; block++) {
2117                 bh = ext4_read_dirblock(dir, block, DIRENT);
2118                 if (IS_ERR(bh)) {
2119                         retval = PTR_ERR(bh);
2120                         bh = NULL;
2121                         goto out;
2122                 }
2123                 retval = add_dirent_to_buf(handle, &fname, dir, inode,
2124                                            NULL, bh);
2125                 if (retval != -ENOSPC)
2126                         goto out;
2127
2128                 if (blocks == 1 && !dx_fallback &&
2129                     ext4_has_feature_dir_index(sb)) {
2130                         retval = make_indexed_dir(handle, &fname, dentry,
2131                                                   inode, bh);
2132                         bh = NULL; /* make_indexed_dir releases bh */
2133                         goto out;
2134                 }
2135                 brelse(bh);
2136         }
2137         bh = ext4_append(handle, dir, &block);
2138         if (IS_ERR(bh)) {
2139                 retval = PTR_ERR(bh);
2140                 bh = NULL;
2141                 goto out;
2142         }
2143         de = (struct ext4_dir_entry_2 *) bh->b_data;
2144         de->inode = 0;
2145         de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize);
2146
2147         if (csum_size) {
2148                 t = EXT4_DIRENT_TAIL(bh->b_data, blocksize);
2149                 initialize_dirent_tail(t, blocksize);
2150         }
2151
2152         retval = add_dirent_to_buf(handle, &fname, dir, inode, de, bh);
2153 out:
2154         ext4_fname_free_filename(&fname);
2155         brelse(bh);
2156         if (retval == 0)
2157                 ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY);
2158         return retval;
2159 }
2160
2161 /*
2162  * Returns 0 for success, or a negative error value
2163  */
2164 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
2165                              struct dentry *dentry, struct inode *inode)
2166 {
2167         struct dx_frame frames[2], *frame;
2168         struct dx_entry *entries, *at;
2169         struct buffer_head *bh;
2170         struct inode *dir = d_inode(dentry->d_parent);
2171         struct super_block *sb = dir->i_sb;
2172         struct ext4_dir_entry_2 *de;
2173         int err;
2174
2175         frame = dx_probe(fname, dir, NULL, frames);
2176         if (IS_ERR(frame))
2177                 return PTR_ERR(frame);
2178         entries = frame->entries;
2179         at = frame->at;
2180         bh = ext4_read_dirblock(dir, dx_get_block(frame->at), DIRENT);
2181         if (IS_ERR(bh)) {
2182                 err = PTR_ERR(bh);
2183                 bh = NULL;
2184                 goto cleanup;
2185         }
2186
2187         BUFFER_TRACE(bh, "get_write_access");
2188         err = ext4_journal_get_write_access(handle, bh);
2189         if (err)
2190                 goto journal_error;
2191
2192         err = add_dirent_to_buf(handle, fname, dir, inode, NULL, bh);
2193         if (err != -ENOSPC)
2194                 goto cleanup;
2195
2196         /* Block full, should compress but for now just split */
2197         dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
2198                        dx_get_count(entries), dx_get_limit(entries)));
2199         /* Need to split index? */
2200         if (dx_get_count(entries) == dx_get_limit(entries)) {
2201                 ext4_lblk_t newblock;
2202                 unsigned icount = dx_get_count(entries);
2203                 int levels = frame - frames;
2204                 struct dx_entry *entries2;
2205                 struct dx_node *node2;
2206                 struct buffer_head *bh2;
2207
2208                 if (levels && (dx_get_count(frames->entries) ==
2209                                dx_get_limit(frames->entries))) {
2210                         ext4_warning_inode(dir, "Directory index full!");
2211                         err = -ENOSPC;
2212                         goto cleanup;
2213                 }
2214                 bh2 = ext4_append(handle, dir, &newblock);
2215                 if (IS_ERR(bh2)) {
2216                         err = PTR_ERR(bh2);
2217                         goto cleanup;
2218                 }
2219                 node2 = (struct dx_node *)(bh2->b_data);
2220                 entries2 = node2->entries;
2221                 memset(&node2->fake, 0, sizeof(struct fake_dirent));
2222                 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
2223                                                            sb->s_blocksize);
2224                 BUFFER_TRACE(frame->bh, "get_write_access");
2225                 err = ext4_journal_get_write_access(handle, frame->bh);
2226                 if (err)
2227                         goto journal_error;
2228                 if (levels) {
2229                         unsigned icount1 = icount/2, icount2 = icount - icount1;
2230                         unsigned hash2 = dx_get_hash(entries + icount1);
2231                         dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
2232                                        icount1, icount2));
2233
2234                         BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
2235                         err = ext4_journal_get_write_access(handle,
2236                                                              frames[0].bh);
2237                         if (err)
2238                                 goto journal_error;
2239
2240                         memcpy((char *) entries2, (char *) (entries + icount1),
2241                                icount2 * sizeof(struct dx_entry));
2242                         dx_set_count(entries, icount1);
2243                         dx_set_count(entries2, icount2);
2244                         dx_set_limit(entries2, dx_node_limit(dir));
2245
2246                         /* Which index block gets the new entry? */
2247                         if (at - entries >= icount1) {
2248                                 frame->at = at = at - entries - icount1 + entries2;
2249                                 frame->entries = entries = entries2;
2250                                 swap(frame->bh, bh2);
2251                         }
2252                         dx_insert_block(frames + 0, hash2, newblock);
2253                         dxtrace(dx_show_index("node", frames[1].entries));
2254                         dxtrace(dx_show_index("node",
2255                                ((struct dx_node *) bh2->b_data)->entries));
2256                         err = ext4_handle_dirty_dx_node(handle, dir, bh2);
2257                         if (err)
2258                                 goto journal_error;
2259                         brelse (bh2);
2260                 } else {
2261                         dxtrace(printk(KERN_DEBUG
2262                                        "Creating second level index...\n"));
2263                         memcpy((char *) entries2, (char *) entries,
2264                                icount * sizeof(struct dx_entry));
2265                         dx_set_limit(entries2, dx_node_limit(dir));
2266
2267                         /* Set up root */
2268                         dx_set_count(entries, 1);
2269                         dx_set_block(entries + 0, newblock);
2270                         ((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels = 1;
2271
2272                         /* Add new access path frame */
2273                         frame = frames + 1;
2274                         frame->at = at = at - entries + entries2;
2275                         frame->entries = entries = entries2;
2276                         frame->bh = bh2;
2277                         err = ext4_journal_get_write_access(handle,
2278                                                              frame->bh);
2279                         if (err)
2280                                 goto journal_error;
2281                 }
2282                 err = ext4_handle_dirty_dx_node(handle, dir, frames[0].bh);
2283                 if (err) {
2284                         ext4_std_error(inode->i_sb, err);
2285                         goto cleanup;
2286                 }
2287         }
2288         de = do_split(handle, dir, &bh, frame, &fname->hinfo);
2289         if (IS_ERR(de)) {
2290                 err = PTR_ERR(de);
2291                 goto cleanup;
2292         }
2293         err = add_dirent_to_buf(handle, fname, dir, inode, de, bh);
2294         goto cleanup;
2295
2296 journal_error:
2297         ext4_std_error(dir->i_sb, err);
2298 cleanup:
2299         brelse(bh);
2300         dx_release(frames);
2301         return err;
2302 }
2303
2304 /*
2305  * ext4_generic_delete_entry deletes a directory entry by merging it
2306  * with the previous entry
2307  */
2308 int ext4_generic_delete_entry(handle_t *handle,
2309                               struct inode *dir,
2310                               struct ext4_dir_entry_2 *de_del,
2311                               struct buffer_head *bh,
2312                               void *entry_buf,
2313                               int buf_size,
2314                               int csum_size)
2315 {
2316         struct ext4_dir_entry_2 *de, *pde;
2317         unsigned int blocksize = dir->i_sb->s_blocksize;
2318         int i;
2319
2320         i = 0;
2321         pde = NULL;
2322         de = (struct ext4_dir_entry_2 *)entry_buf;
2323         while (i < buf_size - csum_size) {
2324                 if (ext4_check_dir_entry(dir, NULL, de, bh,
2325                                          entry_buf, buf_size, i))
2326                         return -EFSCORRUPTED;
2327                 if (de == de_del)  {
2328                         if (pde)
2329                                 pde->rec_len = ext4_rec_len_to_disk(
2330                                         ext4_rec_len_from_disk(pde->rec_len,
2331                                                                blocksize) +
2332                                         ext4_rec_len_from_disk(de->rec_len,
2333                                                                blocksize),
2334                                         blocksize);
2335                         else
2336                                 de->inode = 0;
2337                         dir->i_version++;
2338                         return 0;
2339                 }
2340                 i += ext4_rec_len_from_disk(de->rec_len, blocksize);
2341                 pde = de;
2342                 de = ext4_next_entry(de, blocksize);
2343         }
2344         return -ENOENT;
2345 }
2346
2347 static int ext4_delete_entry(handle_t *handle,
2348                              struct inode *dir,
2349                              struct ext4_dir_entry_2 *de_del,
2350                              struct buffer_head *bh)
2351 {
2352         int err, csum_size = 0;
2353
2354         if (ext4_has_inline_data(dir)) {
2355                 int has_inline_data = 1;
2356                 err = ext4_delete_inline_entry(handle, dir, de_del, bh,
2357                                                &has_inline_data);
2358                 if (has_inline_data)
2359                         return err;
2360         }
2361
2362         if (ext4_has_metadata_csum(dir->i_sb))
2363                 csum_size = sizeof(struct ext4_dir_entry_tail);
2364
2365         BUFFER_TRACE(bh, "get_write_access");
2366         err = ext4_journal_get_write_access(handle, bh);
2367         if (unlikely(err))
2368                 goto out;
2369
2370         err = ext4_generic_delete_entry(handle, dir, de_del,
2371                                         bh, bh->b_data,
2372                                         dir->i_sb->s_blocksize, csum_size);
2373         if (err)
2374                 goto out;
2375
2376         BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
2377         err = ext4_handle_dirty_dirent_node(handle, dir, bh);
2378         if (unlikely(err))
2379                 goto out;
2380
2381         return 0;
2382 out:
2383         if (err != -ENOENT)
2384                 ext4_std_error(dir->i_sb, err);
2385         return err;
2386 }
2387
2388 /*
2389  * DIR_NLINK feature is set if 1) nlinks > EXT4_LINK_MAX or 2) nlinks == 2,
2390  * since this indicates that nlinks count was previously 1.
2391  */
2392 static void ext4_inc_count(handle_t *handle, struct inode *inode)
2393 {
2394         inc_nlink(inode);
2395         if (is_dx(inode) && inode->i_nlink > 1) {
2396                 /* limit is 16-bit i_links_count */
2397                 if (inode->i_nlink >= EXT4_LINK_MAX || inode->i_nlink == 2) {
2398                         set_nlink(inode, 1);
2399                         ext4_set_feature_dir_nlink(inode->i_sb);
2400                 }
2401         }
2402 }
2403
2404 /*
2405  * If a directory had nlink == 1, then we should let it be 1. This indicates
2406  * directory has >EXT4_LINK_MAX subdirs.
2407  */
2408 static void ext4_dec_count(handle_t *handle, struct inode *inode)
2409 {
2410         if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
2411                 drop_nlink(inode);
2412 }
2413
2414
2415 static int ext4_add_nondir(handle_t *handle,
2416                 struct dentry *dentry, struct inode *inode)
2417 {
2418         int err = ext4_add_entry(handle, dentry, inode);
2419         if (!err) {
2420                 ext4_mark_inode_dirty(handle, inode);
2421                 d_instantiate_new(dentry, inode);
2422                 return 0;
2423         }
2424         drop_nlink(inode);
2425         unlock_new_inode(inode);
2426         iput(inode);
2427         return err;
2428 }
2429
2430 /*
2431  * By the time this is called, we already have created
2432  * the directory cache entry for the new file, but it
2433  * is so far negative - it has no inode.
2434  *
2435  * If the create succeeds, we fill in the inode information
2436  * with d_instantiate().
2437  */
2438 static int ext4_create(struct inode *dir, struct dentry *dentry, umode_t mode,
2439                        bool excl)
2440 {
2441         handle_t *handle;
2442         struct inode *inode;
2443         int err, credits, retries = 0;
2444
2445         err = dquot_initialize(dir);
2446         if (err)
2447                 return err;
2448
2449         credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2450                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2451 retry:
2452         inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
2453                                             NULL, EXT4_HT_DIR, credits);
2454         handle = ext4_journal_current_handle();
2455         err = PTR_ERR(inode);
2456         if (!IS_ERR(inode)) {
2457                 inode->i_op = &ext4_file_inode_operations;
2458                 inode->i_fop = &ext4_file_operations;
2459                 ext4_set_aops(inode);
2460                 err = ext4_add_nondir(handle, dentry, inode);
2461                 if (!err && IS_DIRSYNC(dir))
2462                         ext4_handle_sync(handle);
2463         }
2464         if (handle)
2465                 ext4_journal_stop(handle);
2466         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2467                 goto retry;
2468         return err;
2469 }
2470
2471 static int ext4_mknod(struct inode *dir, struct dentry *dentry,
2472                       umode_t mode, dev_t rdev)
2473 {
2474         handle_t *handle;
2475         struct inode *inode;
2476         int err, credits, retries = 0;
2477
2478         err = dquot_initialize(dir);
2479         if (err)
2480                 return err;
2481
2482         credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2483                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2484 retry:
2485         inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
2486                                             NULL, EXT4_HT_DIR, credits);
2487         handle = ext4_journal_current_handle();
2488         err = PTR_ERR(inode);
2489         if (!IS_ERR(inode)) {
2490                 init_special_inode(inode, inode->i_mode, rdev);
2491                 inode->i_op = &ext4_special_inode_operations;
2492                 err = ext4_add_nondir(handle, dentry, inode);
2493                 if (!err && IS_DIRSYNC(dir))
2494                         ext4_handle_sync(handle);
2495         }
2496         if (handle)
2497                 ext4_journal_stop(handle);
2498         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2499                 goto retry;
2500         return err;
2501 }
2502
2503 static int ext4_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
2504 {
2505         handle_t *handle;
2506         struct inode *inode;
2507         int err, retries = 0;
2508
2509         err = dquot_initialize(dir);
2510         if (err)
2511                 return err;
2512
2513 retry:
2514         inode = ext4_new_inode_start_handle(dir, mode,
2515                                             NULL, 0, NULL,
2516                                             EXT4_HT_DIR,
2517                         EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
2518                           4 + EXT4_XATTR_TRANS_BLOCKS);
2519         handle = ext4_journal_current_handle();
2520         err = PTR_ERR(inode);
2521         if (!IS_ERR(inode)) {
2522                 inode->i_op = &ext4_file_inode_operations;
2523                 inode->i_fop = &ext4_file_operations;
2524                 ext4_set_aops(inode);
2525                 d_tmpfile(dentry, inode);
2526                 err = ext4_orphan_add(handle, inode);
2527                 if (err)
2528                         goto err_unlock_inode;
2529                 mark_inode_dirty(inode);
2530                 unlock_new_inode(inode);
2531         }
2532         if (handle)
2533                 ext4_journal_stop(handle);
2534         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2535                 goto retry;
2536         return err;
2537 err_unlock_inode:
2538         ext4_journal_stop(handle);
2539         unlock_new_inode(inode);
2540         return err;
2541 }
2542
2543 struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
2544                           struct ext4_dir_entry_2 *de,
2545                           int blocksize, int csum_size,
2546                           unsigned int parent_ino, int dotdot_real_len)
2547 {
2548         de->inode = cpu_to_le32(inode->i_ino);
2549         de->name_len = 1;
2550         de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
2551                                            blocksize);
2552         strcpy(de->name, ".");
2553         ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2554
2555         de = ext4_next_entry(de, blocksize);
2556         de->inode = cpu_to_le32(parent_ino);
2557         de->name_len = 2;
2558         if (!dotdot_real_len)
2559                 de->rec_len = ext4_rec_len_to_disk(blocksize -
2560                                         (csum_size + EXT4_DIR_REC_LEN(1)),
2561                                         blocksize);
2562         else
2563                 de->rec_len = ext4_rec_len_to_disk(
2564                                 EXT4_DIR_REC_LEN(de->name_len), blocksize);
2565         strcpy(de->name, "..");
2566         ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2567
2568         return ext4_next_entry(de, blocksize);
2569 }
2570
2571 static int ext4_init_new_dir(handle_t *handle, struct inode *dir,
2572                              struct inode *inode)
2573 {
2574         struct buffer_head *dir_block = NULL;
2575         struct ext4_dir_entry_2 *de;
2576         struct ext4_dir_entry_tail *t;
2577         ext4_lblk_t block = 0;
2578         unsigned int blocksize = dir->i_sb->s_blocksize;
2579         int csum_size = 0;
2580         int err;
2581
2582         if (ext4_has_metadata_csum(dir->i_sb))
2583                 csum_size = sizeof(struct ext4_dir_entry_tail);
2584
2585         if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
2586                 err = ext4_try_create_inline_dir(handle, dir, inode);
2587                 if (err < 0 && err != -ENOSPC)
2588                         goto out;
2589                 if (!err)
2590                         goto out;
2591         }
2592
2593         inode->i_size = 0;
2594         dir_block = ext4_append(handle, inode, &block);
2595         if (IS_ERR(dir_block))
2596                 return PTR_ERR(dir_block);
2597         de = (struct ext4_dir_entry_2 *)dir_block->b_data;
2598         ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0);
2599         set_nlink(inode, 2);
2600         if (csum_size) {
2601                 t = EXT4_DIRENT_TAIL(dir_block->b_data, blocksize);
2602                 initialize_dirent_tail(t, blocksize);
2603         }
2604
2605         BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
2606         err = ext4_handle_dirty_dirent_node(handle, inode, dir_block);
2607         if (err)
2608                 goto out;
2609         set_buffer_verified(dir_block);
2610 out:
2611         brelse(dir_block);
2612         return err;
2613 }
2614
2615 static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
2616 {
2617         handle_t *handle;
2618         struct inode *inode;
2619         int err, credits, retries = 0;
2620
2621         if (EXT4_DIR_LINK_MAX(dir))
2622                 return -EMLINK;
2623
2624         err = dquot_initialize(dir);
2625         if (err)
2626                 return err;
2627
2628         credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2629                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2630 retry:
2631         inode = ext4_new_inode_start_handle(dir, S_IFDIR | mode,
2632                                             &dentry->d_name,
2633                                             0, NULL, EXT4_HT_DIR, credits);
2634         handle = ext4_journal_current_handle();
2635         err = PTR_ERR(inode);
2636         if (IS_ERR(inode))
2637                 goto out_stop;
2638
2639         inode->i_op = &ext4_dir_inode_operations;
2640         inode->i_fop = &ext4_dir_operations;
2641         err = ext4_init_new_dir(handle, dir, inode);
2642         if (err)
2643                 goto out_clear_inode;
2644         err = ext4_mark_inode_dirty(handle, inode);
2645         if (!err)
2646                 err = ext4_add_entry(handle, dentry, inode);
2647         if (err) {
2648 out_clear_inode:
2649                 clear_nlink(inode);
2650                 unlock_new_inode(inode);
2651                 ext4_mark_inode_dirty(handle, inode);
2652                 iput(inode);
2653                 goto out_stop;
2654         }
2655         ext4_inc_count(handle, dir);
2656         ext4_update_dx_flag(dir);
2657         err = ext4_mark_inode_dirty(handle, dir);
2658         if (err)
2659                 goto out_clear_inode;
2660         d_instantiate_new(dentry, inode);
2661         if (IS_DIRSYNC(dir))
2662                 ext4_handle_sync(handle);
2663
2664 out_stop:
2665         if (handle)
2666                 ext4_journal_stop(handle);
2667         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2668                 goto retry;
2669         return err;
2670 }
2671
2672 /*
2673  * routine to check that the specified directory is empty (for rmdir)
2674  */
2675 int ext4_empty_dir(struct inode *inode)
2676 {
2677         unsigned int offset;
2678         struct buffer_head *bh;
2679         struct ext4_dir_entry_2 *de, *de1;
2680         struct super_block *sb;
2681         int err = 0;
2682
2683         if (ext4_has_inline_data(inode)) {
2684                 int has_inline_data = 1;
2685
2686                 err = empty_inline_dir(inode, &has_inline_data);
2687                 if (has_inline_data)
2688                         return err;
2689         }
2690
2691         sb = inode->i_sb;
2692         if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2)) {
2693                 EXT4_ERROR_INODE(inode, "invalid size");
2694                 return 1;
2695         }
2696         bh = ext4_read_dirblock(inode, 0, EITHER);
2697         if (IS_ERR(bh))
2698                 return 1;
2699
2700         de = (struct ext4_dir_entry_2 *) bh->b_data;
2701         de1 = ext4_next_entry(de, sb->s_blocksize);
2702         if (le32_to_cpu(de->inode) != inode->i_ino ||
2703                         le32_to_cpu(de1->inode) == 0 ||
2704                         strcmp(".", de->name) || strcmp("..", de1->name)) {
2705                 ext4_warning_inode(inode, "directory missing '.' and/or '..'");
2706                 brelse(bh);
2707                 return 1;
2708         }
2709         offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) +
2710                  ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize);
2711         de = ext4_next_entry(de1, sb->s_blocksize);
2712         while (offset < inode->i_size) {
2713                 if ((void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
2714                         unsigned int lblock;
2715                         err = 0;
2716                         brelse(bh);
2717                         lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb);
2718                         bh = ext4_read_dirblock(inode, lblock, EITHER);
2719                         if (IS_ERR(bh))
2720                                 return 1;
2721                         de = (struct ext4_dir_entry_2 *) bh->b_data;
2722                 }
2723                 if (ext4_check_dir_entry(inode, NULL, de, bh,
2724                                          bh->b_data, bh->b_size, offset)) {
2725                         de = (struct ext4_dir_entry_2 *)(bh->b_data +
2726                                                          sb->s_blocksize);
2727                         offset = (offset | (sb->s_blocksize - 1)) + 1;
2728                         continue;
2729                 }
2730                 if (le32_to_cpu(de->inode)) {
2731                         brelse(bh);
2732                         return 0;
2733                 }
2734                 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
2735                 de = ext4_next_entry(de, sb->s_blocksize);
2736         }
2737         brelse(bh);
2738         return 1;
2739 }
2740
2741 /*
2742  * ext4_orphan_add() links an unlinked or truncated inode into a list of
2743  * such inodes, starting at the superblock, in case we crash before the
2744  * file is closed/deleted, or in case the inode truncate spans multiple
2745  * transactions and the last transaction is not recovered after a crash.
2746  *
2747  * At filesystem recovery time, we walk this list deleting unlinked
2748  * inodes and truncating linked inodes in ext4_orphan_cleanup().
2749  *
2750  * Orphan list manipulation functions must be called under i_mutex unless
2751  * we are just creating the inode or deleting it.
2752  */
2753 int ext4_orphan_add(handle_t *handle, struct inode *inode)
2754 {
2755         struct super_block *sb = inode->i_sb;
2756         struct ext4_sb_info *sbi = EXT4_SB(sb);
2757         struct ext4_iloc iloc;
2758         int err = 0, rc;
2759         bool dirty = false;
2760
2761         if (!sbi->s_journal || is_bad_inode(inode))
2762                 return 0;
2763
2764         WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
2765                      !mutex_is_locked(&inode->i_mutex));
2766         /*
2767          * Exit early if inode already is on orphan list. This is a big speedup
2768          * since we don't have to contend on the global s_orphan_lock.
2769          */
2770         if (!list_empty(&EXT4_I(inode)->i_orphan))
2771                 return 0;
2772
2773         /*
2774          * Orphan handling is only valid for files with data blocks
2775          * being truncated, or files being unlinked. Note that we either
2776          * hold i_mutex, or the inode can not be referenced from outside,
2777          * so i_nlink should not be bumped due to race
2778          */
2779         J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2780                   S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
2781
2782         BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2783         err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2784         if (err)
2785                 goto out;
2786
2787         err = ext4_reserve_inode_write(handle, inode, &iloc);
2788         if (err)
2789                 goto out;
2790
2791         mutex_lock(&sbi->s_orphan_lock);
2792         /*
2793          * Due to previous errors inode may be already a part of on-disk
2794          * orphan list. If so skip on-disk list modification.
2795          */
2796         if (!NEXT_ORPHAN(inode) || NEXT_ORPHAN(inode) >
2797             (le32_to_cpu(sbi->s_es->s_inodes_count))) {
2798                 /* Insert this inode at the head of the on-disk orphan list */
2799                 NEXT_ORPHAN(inode) = le32_to_cpu(sbi->s_es->s_last_orphan);
2800                 sbi->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
2801                 dirty = true;
2802         }
2803         list_add(&EXT4_I(inode)->i_orphan, &sbi->s_orphan);
2804         mutex_unlock(&sbi->s_orphan_lock);
2805
2806         if (dirty) {
2807                 err = ext4_handle_dirty_super(handle, sb);
2808                 rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
2809                 if (!err)
2810                         err = rc;
2811                 if (err) {
2812                         /*
2813                          * We have to remove inode from in-memory list if
2814                          * addition to on disk orphan list failed. Stray orphan
2815                          * list entries can cause panics at unmount time.
2816                          */
2817                         mutex_lock(&sbi->s_orphan_lock);
2818                         list_del_init(&EXT4_I(inode)->i_orphan);
2819                         mutex_unlock(&sbi->s_orphan_lock);
2820                 }
2821         } else
2822                 brelse(iloc.bh);
2823
2824         jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
2825         jbd_debug(4, "orphan inode %lu will point to %d\n",
2826                         inode->i_ino, NEXT_ORPHAN(inode));
2827 out:
2828         ext4_std_error(sb, err);
2829         return err;
2830 }
2831
2832 /*
2833  * ext4_orphan_del() removes an unlinked or truncated inode from the list
2834  * of such inodes stored on disk, because it is finally being cleaned up.
2835  */
2836 int ext4_orphan_del(handle_t *handle, struct inode *inode)
2837 {
2838         struct list_head *prev;
2839         struct ext4_inode_info *ei = EXT4_I(inode);
2840         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2841         __u32 ino_next;
2842         struct ext4_iloc iloc;
2843         int err = 0;
2844
2845         if (!sbi->s_journal && !(sbi->s_mount_state & EXT4_ORPHAN_FS))
2846                 return 0;
2847
2848         WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
2849                      !mutex_is_locked(&inode->i_mutex));
2850         /* Do this quick check before taking global s_orphan_lock. */
2851         if (list_empty(&ei->i_orphan))
2852                 return 0;
2853
2854         if (handle) {
2855                 /* Grab inode buffer early before taking global s_orphan_lock */
2856                 err = ext4_reserve_inode_write(handle, inode, &iloc);
2857         }
2858
2859         mutex_lock(&sbi->s_orphan_lock);
2860         jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
2861
2862         prev = ei->i_orphan.prev;
2863         list_del_init(&ei->i_orphan);
2864
2865         /* If we're on an error path, we may not have a valid
2866          * transaction handle with which to update the orphan list on
2867          * disk, but we still need to remove the inode from the linked
2868          * list in memory. */
2869         if (!handle || err) {
2870                 mutex_unlock(&sbi->s_orphan_lock);
2871                 goto out_err;
2872         }
2873
2874         ino_next = NEXT_ORPHAN(inode);
2875         if (prev == &sbi->s_orphan) {
2876                 jbd_debug(4, "superblock will point to %u\n", ino_next);
2877                 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2878                 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2879                 if (err) {
2880                         mutex_unlock(&sbi->s_orphan_lock);
2881                         goto out_brelse;
2882                 }
2883                 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
2884                 mutex_unlock(&sbi->s_orphan_lock);
2885                 err = ext4_handle_dirty_super(handle, inode->i_sb);
2886         } else {
2887                 struct ext4_iloc iloc2;
2888                 struct inode *i_prev =
2889                         &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
2890
2891                 jbd_debug(4, "orphan inode %lu will point to %u\n",
2892                           i_prev->i_ino, ino_next);
2893                 err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
2894                 if (err) {
2895                         mutex_unlock(&sbi->s_orphan_lock);
2896                         goto out_brelse;
2897                 }
2898                 NEXT_ORPHAN(i_prev) = ino_next;
2899                 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
2900                 mutex_unlock(&sbi->s_orphan_lock);
2901         }
2902         if (err)
2903                 goto out_brelse;
2904         NEXT_ORPHAN(inode) = 0;
2905         err = ext4_mark_iloc_dirty(handle, inode, &iloc);
2906 out_err:
2907         ext4_std_error(inode->i_sb, err);
2908         return err;
2909
2910 out_brelse:
2911         brelse(iloc.bh);
2912         goto out_err;
2913 }
2914
2915 static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
2916 {
2917         int retval;
2918         struct inode *inode;
2919         struct buffer_head *bh;
2920         struct ext4_dir_entry_2 *de;
2921         handle_t *handle = NULL;
2922
2923         /* Initialize quotas before so that eventual writes go in
2924          * separate transaction */
2925         retval = dquot_initialize(dir);
2926         if (retval)
2927                 return retval;
2928         retval = dquot_initialize(d_inode(dentry));
2929         if (retval)
2930                 return retval;
2931
2932         retval = -ENOENT;
2933         bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
2934         if (IS_ERR(bh))
2935                 return PTR_ERR(bh);
2936         if (!bh)
2937                 goto end_rmdir;
2938
2939         inode = d_inode(dentry);
2940
2941         retval = -EFSCORRUPTED;
2942         if (le32_to_cpu(de->inode) != inode->i_ino)
2943                 goto end_rmdir;
2944
2945         retval = -ENOTEMPTY;
2946         if (!ext4_empty_dir(inode))
2947                 goto end_rmdir;
2948
2949         handle = ext4_journal_start(dir, EXT4_HT_DIR,
2950                                     EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
2951         if (IS_ERR(handle)) {
2952                 retval = PTR_ERR(handle);
2953                 handle = NULL;
2954                 goto end_rmdir;
2955         }
2956
2957         if (IS_DIRSYNC(dir))
2958                 ext4_handle_sync(handle);
2959
2960         retval = ext4_delete_entry(handle, dir, de, bh);
2961         if (retval)
2962                 goto end_rmdir;
2963         if (!EXT4_DIR_LINK_EMPTY(inode))
2964                 ext4_warning_inode(inode,
2965                              "empty directory '%.*s' has too many links (%u)",
2966                              dentry->d_name.len, dentry->d_name.name,
2967                              inode->i_nlink);
2968         inode->i_version++;
2969         clear_nlink(inode);
2970         /* There's no need to set i_disksize: the fact that i_nlink is
2971          * zero will ensure that the right thing happens during any
2972          * recovery. */
2973         inode->i_size = 0;
2974         ext4_orphan_add(handle, inode);
2975         inode->i_ctime = dir->i_ctime = dir->i_mtime = ext4_current_time(inode);
2976         ext4_mark_inode_dirty(handle, inode);
2977         ext4_dec_count(handle, dir);
2978         ext4_update_dx_flag(dir);
2979         ext4_mark_inode_dirty(handle, dir);
2980
2981 end_rmdir:
2982         brelse(bh);
2983         if (handle)
2984                 ext4_journal_stop(handle);
2985         return retval;
2986 }
2987
2988 static int ext4_unlink(struct inode *dir, struct dentry *dentry)
2989 {
2990         int retval;
2991         struct inode *inode;
2992         struct buffer_head *bh;
2993         struct ext4_dir_entry_2 *de;
2994         handle_t *handle = NULL;
2995
2996         trace_ext4_unlink_enter(dir, dentry);
2997         /* Initialize quotas before so that eventual writes go
2998          * in separate transaction */
2999         retval = dquot_initialize(dir);
3000         if (retval)
3001                 return retval;
3002         retval = dquot_initialize(d_inode(dentry));
3003         if (retval)
3004                 return retval;
3005
3006         retval = -ENOENT;
3007         bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
3008         if (IS_ERR(bh))
3009                 return PTR_ERR(bh);
3010         if (!bh)
3011                 goto end_unlink;
3012
3013         inode = d_inode(dentry);
3014
3015         retval = -EFSCORRUPTED;
3016         if (le32_to_cpu(de->inode) != inode->i_ino)
3017                 goto end_unlink;
3018
3019         handle = ext4_journal_start(dir, EXT4_HT_DIR,
3020                                     EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
3021         if (IS_ERR(handle)) {
3022                 retval = PTR_ERR(handle);
3023                 handle = NULL;
3024                 goto end_unlink;
3025         }
3026
3027         if (IS_DIRSYNC(dir))
3028                 ext4_handle_sync(handle);
3029
3030         retval = ext4_delete_entry(handle, dir, de, bh);
3031         if (retval)
3032                 goto end_unlink;
3033         dir->i_ctime = dir->i_mtime = ext4_current_time(dir);
3034         ext4_update_dx_flag(dir);
3035         ext4_mark_inode_dirty(handle, dir);
3036         if (inode->i_nlink == 0)
3037                 ext4_warning_inode(inode, "Deleting file '%.*s' with no links",
3038                                    dentry->d_name.len, dentry->d_name.name);
3039         else
3040                 drop_nlink(inode);
3041         if (!inode->i_nlink)
3042                 ext4_orphan_add(handle, inode);
3043         inode->i_ctime = ext4_current_time(inode);
3044         ext4_mark_inode_dirty(handle, inode);
3045
3046 end_unlink:
3047         brelse(bh);
3048         if (handle)
3049                 ext4_journal_stop(handle);
3050         trace_ext4_unlink_exit(dentry, retval);
3051         return retval;
3052 }
3053
3054 static int ext4_symlink(struct inode *dir,
3055                         struct dentry *dentry, const char *symname)
3056 {
3057         handle_t *handle;
3058         struct inode *inode;
3059         int err, len = strlen(symname);
3060         int credits;
3061         bool encryption_required;
3062         struct ext4_str disk_link;
3063         struct ext4_encrypted_symlink_data *sd = NULL;
3064
3065         disk_link.len = len + 1;
3066         disk_link.name = (char *) symname;
3067
3068         encryption_required = (ext4_encrypted_inode(dir) ||
3069                                DUMMY_ENCRYPTION_ENABLED(EXT4_SB(dir->i_sb)));
3070         if (encryption_required) {
3071                 err = ext4_get_encryption_info(dir);
3072                 if (err)
3073                         return err;
3074                 if (ext4_encryption_info(dir) == NULL)
3075                         return -EPERM;
3076                 disk_link.len = (ext4_fname_encrypted_size(dir, len) +
3077                                  sizeof(struct ext4_encrypted_symlink_data));
3078                 sd = kzalloc(disk_link.len, GFP_KERNEL);
3079                 if (!sd)
3080                         return -ENOMEM;
3081         }
3082
3083         if (disk_link.len > dir->i_sb->s_blocksize) {
3084                 err = -ENAMETOOLONG;
3085                 goto err_free_sd;
3086         }
3087
3088         err = dquot_initialize(dir);
3089         if (err)
3090                 goto err_free_sd;
3091
3092         if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
3093                 /*
3094                  * For non-fast symlinks, we just allocate inode and put it on
3095                  * orphan list in the first transaction => we need bitmap,
3096                  * group descriptor, sb, inode block, quota blocks, and
3097                  * possibly selinux xattr blocks.
3098                  */
3099                 credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
3100                           EXT4_XATTR_TRANS_BLOCKS;
3101         } else {
3102                 /*
3103                  * Fast symlink. We have to add entry to directory
3104                  * (EXT4_DATA_TRANS_BLOCKS + EXT4_INDEX_EXTRA_TRANS_BLOCKS),
3105                  * allocate new inode (bitmap, group descriptor, inode block,
3106                  * quota blocks, sb is already counted in previous macros).
3107                  */
3108                 credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3109                           EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3;
3110         }
3111
3112         inode = ext4_new_inode_start_handle(dir, S_IFLNK|S_IRWXUGO,
3113                                             &dentry->d_name, 0, NULL,
3114                                             EXT4_HT_DIR, credits);
3115         handle = ext4_journal_current_handle();
3116         if (IS_ERR(inode)) {
3117                 if (handle)
3118                         ext4_journal_stop(handle);
3119                 err = PTR_ERR(inode);
3120                 goto err_free_sd;
3121         }
3122
3123         if (encryption_required) {
3124                 struct qstr istr;
3125                 struct ext4_str ostr;
3126
3127                 istr.name = (const unsigned char *) symname;
3128                 istr.len = len;
3129                 ostr.name = sd->encrypted_path;
3130                 ostr.len = disk_link.len;
3131                 err = ext4_fname_usr_to_disk(inode, &istr, &ostr);
3132                 if (err < 0)
3133                         goto err_drop_inode;
3134                 sd->len = cpu_to_le16(ostr.len);
3135                 disk_link.name = (char *) sd;
3136                 inode->i_op = &ext4_encrypted_symlink_inode_operations;
3137         }
3138
3139         if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
3140                 if (!encryption_required)
3141                         inode->i_op = &ext4_symlink_inode_operations;
3142                 inode_nohighmem(inode);
3143                 ext4_set_aops(inode);
3144                 /*
3145                  * We cannot call page_symlink() with transaction started
3146                  * because it calls into ext4_write_begin() which can wait
3147                  * for transaction commit if we are running out of space
3148                  * and thus we deadlock. So we have to stop transaction now
3149                  * and restart it when symlink contents is written.
3150                  *
3151                  * To keep fs consistent in case of crash, we have to put inode
3152                  * to orphan list in the mean time.
3153                  */
3154                 drop_nlink(inode);
3155                 err = ext4_orphan_add(handle, inode);
3156                 ext4_journal_stop(handle);
3157                 handle = NULL;
3158                 if (err)
3159                         goto err_drop_inode;
3160                 err = __page_symlink(inode, disk_link.name, disk_link.len, 1);
3161                 if (err)
3162                         goto err_drop_inode;
3163                 /*
3164                  * Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS
3165                  * + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified
3166                  */
3167                 handle = ext4_journal_start(dir, EXT4_HT_DIR,
3168                                 EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3169                                 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1);
3170                 if (IS_ERR(handle)) {
3171                         err = PTR_ERR(handle);
3172                         handle = NULL;
3173                         goto err_drop_inode;
3174                 }
3175                 set_nlink(inode, 1);
3176                 err = ext4_orphan_del(handle, inode);
3177                 if (err)
3178                         goto err_drop_inode;
3179         } else {
3180                 /* clear the extent format for fast symlink */
3181                 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
3182                 if (!encryption_required) {
3183                         inode->i_op = &ext4_fast_symlink_inode_operations;
3184                         inode->i_link = (char *)&EXT4_I(inode)->i_data;
3185                 }
3186                 memcpy((char *)&EXT4_I(inode)->i_data, disk_link.name,
3187                        disk_link.len);
3188                 inode->i_size = disk_link.len - 1;
3189         }
3190         EXT4_I(inode)->i_disksize = inode->i_size;
3191         err = ext4_add_nondir(handle, dentry, inode);
3192         if (!err && IS_DIRSYNC(dir))
3193                 ext4_handle_sync(handle);
3194
3195         if (handle)
3196                 ext4_journal_stop(handle);
3197         kfree(sd);
3198         return err;
3199 err_drop_inode:
3200         if (handle)
3201                 ext4_journal_stop(handle);
3202         clear_nlink(inode);
3203         unlock_new_inode(inode);
3204         iput(inode);
3205 err_free_sd:
3206         kfree(sd);
3207         return err;
3208 }
3209
3210 static int ext4_link(struct dentry *old_dentry,
3211                      struct inode *dir, struct dentry *dentry)
3212 {
3213         handle_t *handle;
3214         struct inode *inode = d_inode(old_dentry);
3215         int err, retries = 0;
3216
3217         if (inode->i_nlink >= EXT4_LINK_MAX)
3218                 return -EMLINK;
3219         if (ext4_encrypted_inode(dir) &&
3220             !ext4_is_child_context_consistent_with_parent(dir, inode))
3221                 return -EXDEV;
3222         err = dquot_initialize(dir);
3223         if (err)
3224                 return err;
3225
3226 retry:
3227         handle = ext4_journal_start(dir, EXT4_HT_DIR,
3228                 (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3229                  EXT4_INDEX_EXTRA_TRANS_BLOCKS) + 1);
3230         if (IS_ERR(handle))
3231                 return PTR_ERR(handle);
3232
3233         if (IS_DIRSYNC(dir))
3234                 ext4_handle_sync(handle);
3235
3236         inode->i_ctime = ext4_current_time(inode);
3237         ext4_inc_count(handle, inode);
3238         ihold(inode);
3239
3240         err = ext4_add_entry(handle, dentry, inode);
3241         if (!err) {
3242                 ext4_mark_inode_dirty(handle, inode);
3243                 /* this can happen only for tmpfile being
3244                  * linked the first time
3245                  */
3246                 if (inode->i_nlink == 1)
3247                         ext4_orphan_del(handle, inode);
3248                 d_instantiate(dentry, inode);
3249         } else {
3250                 drop_nlink(inode);
3251                 iput(inode);
3252         }
3253         ext4_journal_stop(handle);
3254         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
3255                 goto retry;
3256         return err;
3257 }
3258
3259
3260 /*
3261  * Try to find buffer head where contains the parent block.
3262  * It should be the inode block if it is inlined or the 1st block
3263  * if it is a normal dir.
3264  */
3265 static struct buffer_head *ext4_get_first_dir_block(handle_t *handle,
3266                                         struct inode *inode,
3267                                         int *retval,
3268                                         struct ext4_dir_entry_2 **parent_de,
3269                                         int *inlined)
3270 {
3271         struct buffer_head *bh;
3272
3273         if (!ext4_has_inline_data(inode)) {
3274                 bh = ext4_read_dirblock(inode, 0, EITHER);
3275                 if (IS_ERR(bh)) {
3276                         *retval = PTR_ERR(bh);
3277                         return NULL;
3278                 }
3279                 *parent_de = ext4_next_entry(
3280                                         (struct ext4_dir_entry_2 *)bh->b_data,
3281                                         inode->i_sb->s_blocksize);
3282                 return bh;
3283         }
3284
3285         *inlined = 1;
3286         return ext4_get_first_inline_block(inode, parent_de, retval);
3287 }
3288
3289 struct ext4_renament {
3290         struct inode *dir;
3291         struct dentry *dentry;
3292         struct inode *inode;
3293         bool is_dir;
3294         int dir_nlink_delta;
3295
3296         /* entry for "dentry" */
3297         struct buffer_head *bh;
3298         struct ext4_dir_entry_2 *de;
3299         int inlined;
3300
3301         /* entry for ".." in inode if it's a directory */
3302         struct buffer_head *dir_bh;
3303         struct ext4_dir_entry_2 *parent_de;
3304         int dir_inlined;
3305 };
3306
3307 static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent)
3308 {
3309         int retval;
3310
3311         ent->dir_bh = ext4_get_first_dir_block(handle, ent->inode,
3312                                               &retval, &ent->parent_de,
3313                                               &ent->dir_inlined);
3314         if (!ent->dir_bh)
3315                 return retval;
3316         if (le32_to_cpu(ent->parent_de->inode) != ent->dir->i_ino)
3317                 return -EFSCORRUPTED;
3318         BUFFER_TRACE(ent->dir_bh, "get_write_access");
3319         return ext4_journal_get_write_access(handle, ent->dir_bh);
3320 }
3321
3322 static int ext4_rename_dir_finish(handle_t *handle, struct ext4_renament *ent,
3323                                   unsigned dir_ino)
3324 {
3325         int retval;
3326
3327         ent->parent_de->inode = cpu_to_le32(dir_ino);
3328         BUFFER_TRACE(ent->dir_bh, "call ext4_handle_dirty_metadata");
3329         if (!ent->dir_inlined) {
3330                 if (is_dx(ent->inode)) {
3331                         retval = ext4_handle_dirty_dx_node(handle,
3332                                                            ent->inode,
3333                                                            ent->dir_bh);
3334                 } else {
3335                         retval = ext4_handle_dirty_dirent_node(handle,
3336                                                                ent->inode,
3337                                                                ent->dir_bh);
3338                 }
3339         } else {
3340                 retval = ext4_mark_inode_dirty(handle, ent->inode);
3341         }
3342         if (retval) {
3343                 ext4_std_error(ent->dir->i_sb, retval);
3344                 return retval;
3345         }
3346         return 0;
3347 }
3348
3349 static int ext4_setent(handle_t *handle, struct ext4_renament *ent,
3350                        unsigned ino, unsigned file_type)
3351 {
3352         int retval;
3353
3354         BUFFER_TRACE(ent->bh, "get write access");
3355         retval = ext4_journal_get_write_access(handle, ent->bh);
3356         if (retval)
3357                 return retval;
3358         ent->de->inode = cpu_to_le32(ino);
3359         if (ext4_has_feature_filetype(ent->dir->i_sb))
3360                 ent->de->file_type = file_type;
3361         ent->dir->i_version++;
3362         ent->dir->i_ctime = ent->dir->i_mtime =
3363                 ext4_current_time(ent->dir);
3364         ext4_mark_inode_dirty(handle, ent->dir);
3365         BUFFER_TRACE(ent->bh, "call ext4_handle_dirty_metadata");
3366         if (!ent->inlined) {
3367                 retval = ext4_handle_dirty_dirent_node(handle,
3368                                                        ent->dir, ent->bh);
3369                 if (unlikely(retval)) {
3370                         ext4_std_error(ent->dir->i_sb, retval);
3371                         return retval;
3372                 }
3373         }
3374
3375         return 0;
3376 }
3377
3378 static void ext4_resetent(handle_t *handle, struct ext4_renament *ent,
3379                           unsigned ino, unsigned file_type)
3380 {
3381         struct ext4_renament old = *ent;
3382         int retval = 0;
3383
3384         /*
3385          * old->de could have moved from under us during make indexed dir,
3386          * so the old->de may no longer valid and need to find it again
3387          * before reset old inode info.
3388          */
3389         old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, NULL);
3390         if (IS_ERR(old.bh))
3391                 retval = PTR_ERR(old.bh);
3392         if (!old.bh)
3393                 retval = -ENOENT;
3394         if (retval) {
3395                 ext4_std_error(old.dir->i_sb, retval);
3396                 return;
3397         }
3398
3399         ext4_setent(handle, &old, ino, file_type);
3400         brelse(old.bh);
3401 }
3402
3403 static int ext4_find_delete_entry(handle_t *handle, struct inode *dir,
3404                                   const struct qstr *d_name)
3405 {
3406         int retval = -ENOENT;
3407         struct buffer_head *bh;
3408         struct ext4_dir_entry_2 *de;
3409
3410         bh = ext4_find_entry(dir, d_name, &de, NULL);
3411         if (IS_ERR(bh))
3412                 return PTR_ERR(bh);
3413         if (bh) {
3414                 retval = ext4_delete_entry(handle, dir, de, bh);
3415                 brelse(bh);
3416         }
3417         return retval;
3418 }
3419
3420 static void ext4_rename_delete(handle_t *handle, struct ext4_renament *ent,
3421                                int force_reread)
3422 {
3423         int retval;
3424         /*
3425          * ent->de could have moved from under us during htree split, so make
3426          * sure that we are deleting the right entry.  We might also be pointing
3427          * to a stale entry in the unused part of ent->bh so just checking inum
3428          * and the name isn't enough.
3429          */
3430         if (le32_to_cpu(ent->de->inode) != ent->inode->i_ino ||
3431             ent->de->name_len != ent->dentry->d_name.len ||
3432             strncmp(ent->de->name, ent->dentry->d_name.name,
3433                     ent->de->name_len) ||
3434             force_reread) {
3435                 retval = ext4_find_delete_entry(handle, ent->dir,
3436                                                 &ent->dentry->d_name);
3437         } else {
3438                 retval = ext4_delete_entry(handle, ent->dir, ent->de, ent->bh);
3439                 if (retval == -ENOENT) {
3440                         retval = ext4_find_delete_entry(handle, ent->dir,
3441                                                         &ent->dentry->d_name);
3442                 }
3443         }
3444
3445         if (retval) {
3446                 ext4_warning_inode(ent->dir,
3447                                    "Deleting old file: nlink %d, error=%d",
3448                                    ent->dir->i_nlink, retval);
3449         }
3450 }
3451
3452 static void ext4_update_dir_count(handle_t *handle, struct ext4_renament *ent)
3453 {
3454         if (ent->dir_nlink_delta) {
3455                 if (ent->dir_nlink_delta == -1)
3456                         ext4_dec_count(handle, ent->dir);
3457                 else
3458                         ext4_inc_count(handle, ent->dir);
3459                 ext4_mark_inode_dirty(handle, ent->dir);
3460         }
3461 }
3462
3463 static struct inode *ext4_whiteout_for_rename(struct ext4_renament *ent,
3464                                               int credits, handle_t **h)
3465 {
3466         struct inode *wh;
3467         handle_t *handle;
3468         int retries = 0;
3469
3470         /*
3471          * for inode block, sb block, group summaries,
3472          * and inode bitmap
3473          */
3474         credits += (EXT4_MAXQUOTAS_TRANS_BLOCKS(ent->dir->i_sb) +
3475                     EXT4_XATTR_TRANS_BLOCKS + 4);
3476 retry:
3477         wh = ext4_new_inode_start_handle(ent->dir, S_IFCHR | WHITEOUT_MODE,
3478                                          &ent->dentry->d_name, 0, NULL,
3479                                          EXT4_HT_DIR, credits);
3480
3481         handle = ext4_journal_current_handle();
3482         if (IS_ERR(wh)) {
3483                 if (handle)
3484                         ext4_journal_stop(handle);
3485                 if (PTR_ERR(wh) == -ENOSPC &&
3486                     ext4_should_retry_alloc(ent->dir->i_sb, &retries))
3487                         goto retry;
3488         } else {
3489                 *h = handle;
3490                 init_special_inode(wh, wh->i_mode, WHITEOUT_DEV);
3491                 wh->i_op = &ext4_special_inode_operations;
3492         }
3493         return wh;
3494 }
3495
3496 /*
3497  * Anybody can rename anything with this: the permission checks are left to the
3498  * higher-level routines.
3499  *
3500  * n.b.  old_{dentry,inode) refers to the source dentry/inode
3501  * while new_{dentry,inode) refers to the destination dentry/inode
3502  * This comes from rename(const char *oldpath, const char *newpath)
3503  */
3504 static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
3505                        struct inode *new_dir, struct dentry *new_dentry,
3506                        unsigned int flags)
3507 {
3508         handle_t *handle = NULL;
3509         struct ext4_renament old = {
3510                 .dir = old_dir,
3511                 .dentry = old_dentry,
3512                 .inode = d_inode(old_dentry),
3513         };
3514         struct ext4_renament new = {
3515                 .dir = new_dir,
3516                 .dentry = new_dentry,
3517                 .inode = d_inode(new_dentry),
3518         };
3519         int force_reread;
3520         int retval;
3521         struct inode *whiteout = NULL;
3522         int credits;
3523         u8 old_file_type;
3524
3525         if ((ext4_encrypted_inode(old_dir) &&
3526              !ext4_has_encryption_key(old_dir)) ||
3527             (ext4_encrypted_inode(new_dir) &&
3528              !ext4_has_encryption_key(new_dir)))
3529                 return -ENOKEY;
3530
3531         retval = dquot_initialize(old.dir);
3532         if (retval)
3533                 return retval;
3534         retval = dquot_initialize(new.dir);
3535         if (retval)
3536                 return retval;
3537
3538         /* Initialize quotas before so that eventual writes go
3539          * in separate transaction */
3540         if (new.inode) {
3541                 retval = dquot_initialize(new.inode);
3542                 if (retval)
3543                         return retval;
3544         }
3545
3546         old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, NULL);
3547         if (IS_ERR(old.bh))
3548                 return PTR_ERR(old.bh);
3549         /*
3550          *  Check for inode number is _not_ due to possible IO errors.
3551          *  We might rmdir the source, keep it as pwd of some process
3552          *  and merrily kill the link to whatever was created under the
3553          *  same name. Goodbye sticky bit ;-<
3554          */
3555         retval = -ENOENT;
3556         if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3557                 goto release_bh;
3558
3559         if ((old.dir != new.dir) &&
3560             ext4_encrypted_inode(new.dir) &&
3561             !ext4_is_child_context_consistent_with_parent(new.dir,
3562                                                           old.inode)) {
3563                 retval = -EXDEV;
3564                 goto release_bh;
3565         }
3566
3567         new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
3568                                  &new.de, &new.inlined);
3569         if (IS_ERR(new.bh)) {
3570                 retval = PTR_ERR(new.bh);
3571                 new.bh = NULL;
3572                 goto release_bh;
3573         }
3574         if (new.bh) {
3575                 if (!new.inode) {
3576                         brelse(new.bh);
3577                         new.bh = NULL;
3578                 }
3579         }
3580         if (new.inode && !test_opt(new.dir->i_sb, NO_AUTO_DA_ALLOC))
3581                 ext4_alloc_da_blocks(old.inode);
3582
3583         credits = (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3584                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
3585         if (!(flags & RENAME_WHITEOUT)) {
3586                 handle = ext4_journal_start(old.dir, EXT4_HT_DIR, credits);
3587                 if (IS_ERR(handle)) {
3588                         retval = PTR_ERR(handle);
3589                         goto release_bh;
3590                 }
3591         } else {
3592                 whiteout = ext4_whiteout_for_rename(&old, credits, &handle);
3593                 if (IS_ERR(whiteout)) {
3594                         retval = PTR_ERR(whiteout);
3595                         goto release_bh;
3596                 }
3597         }
3598
3599         old_file_type = old.de->file_type;
3600         if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3601                 ext4_handle_sync(handle);
3602
3603         if (S_ISDIR(old.inode->i_mode)) {
3604                 if (new.inode) {
3605                         retval = -ENOTEMPTY;
3606                         if (!ext4_empty_dir(new.inode))
3607                                 goto end_rename;
3608                 } else {
3609                         retval = -EMLINK;
3610                         if (new.dir != old.dir && EXT4_DIR_LINK_MAX(new.dir))
3611                                 goto end_rename;
3612                 }
3613                 retval = ext4_rename_dir_prepare(handle, &old);
3614                 if (retval)
3615                         goto end_rename;
3616         }
3617         /*
3618          * If we're renaming a file within an inline_data dir and adding or
3619          * setting the new dirent causes a conversion from inline_data to
3620          * extents/blockmap, we need to force the dirent delete code to
3621          * re-read the directory, or else we end up trying to delete a dirent
3622          * from what is now the extent tree root (or a block map).
3623          */
3624         force_reread = (new.dir->i_ino == old.dir->i_ino &&
3625                         ext4_test_inode_flag(new.dir, EXT4_INODE_INLINE_DATA));
3626
3627         if (whiteout) {
3628                 /*
3629                  * Do this before adding a new entry, so the old entry is sure
3630                  * to be still pointing to the valid old entry.
3631                  */
3632                 retval = ext4_setent(handle, &old, whiteout->i_ino,
3633                                      EXT4_FT_CHRDEV);
3634                 if (retval)
3635                         goto end_rename;
3636                 ext4_mark_inode_dirty(handle, whiteout);
3637         }
3638         if (!new.bh) {
3639                 retval = ext4_add_entry(handle, new.dentry, old.inode);
3640                 if (retval)
3641                         goto end_rename;
3642         } else {
3643                 retval = ext4_setent(handle, &new,
3644                                      old.inode->i_ino, old_file_type);
3645                 if (retval)
3646                         goto end_rename;
3647         }
3648         if (force_reread)
3649                 force_reread = !ext4_test_inode_flag(new.dir,
3650                                                      EXT4_INODE_INLINE_DATA);
3651
3652         /*
3653          * Like most other Unix systems, set the ctime for inodes on a
3654          * rename.
3655          */
3656         old.inode->i_ctime = ext4_current_time(old.inode);
3657         ext4_mark_inode_dirty(handle, old.inode);
3658
3659         if (!whiteout) {
3660                 /*
3661                  * ok, that's it
3662                  */
3663                 ext4_rename_delete(handle, &old, force_reread);
3664         }
3665
3666         if (new.inode) {
3667                 ext4_dec_count(handle, new.inode);
3668                 new.inode->i_ctime = ext4_current_time(new.inode);
3669         }
3670         old.dir->i_ctime = old.dir->i_mtime = ext4_current_time(old.dir);
3671         ext4_update_dx_flag(old.dir);
3672         if (old.dir_bh) {
3673                 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
3674                 if (retval)
3675                         goto end_rename;
3676
3677                 ext4_dec_count(handle, old.dir);
3678                 if (new.inode) {
3679                         /* checked ext4_empty_dir above, can't have another
3680                          * parent, ext4_dec_count() won't work for many-linked
3681                          * dirs */
3682                         clear_nlink(new.inode);
3683                 } else {
3684                         ext4_inc_count(handle, new.dir);
3685                         ext4_update_dx_flag(new.dir);
3686                         ext4_mark_inode_dirty(handle, new.dir);
3687                 }
3688         }
3689         ext4_mark_inode_dirty(handle, old.dir);
3690         if (new.inode) {
3691                 ext4_mark_inode_dirty(handle, new.inode);
3692                 if (!new.inode->i_nlink)
3693                         ext4_orphan_add(handle, new.inode);
3694         }
3695         retval = 0;
3696
3697 end_rename:
3698         if (whiteout) {
3699                 if (retval) {
3700                         ext4_resetent(handle, &old,
3701                                       old.inode->i_ino, old_file_type);
3702                         drop_nlink(whiteout);
3703                         ext4_orphan_add(handle, whiteout);
3704                 }
3705                 unlock_new_inode(whiteout);
3706                 ext4_journal_stop(handle);
3707                 iput(whiteout);
3708         } else {
3709                 ext4_journal_stop(handle);
3710         }
3711 release_bh:
3712         brelse(old.dir_bh);
3713         brelse(old.bh);
3714         brelse(new.bh);
3715         return retval;
3716 }
3717
3718 static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
3719                              struct inode *new_dir, struct dentry *new_dentry)
3720 {
3721         handle_t *handle = NULL;
3722         struct ext4_renament old = {
3723                 .dir = old_dir,
3724                 .dentry = old_dentry,
3725                 .inode = d_inode(old_dentry),
3726         };
3727         struct ext4_renament new = {
3728                 .dir = new_dir,
3729                 .dentry = new_dentry,
3730                 .inode = d_inode(new_dentry),
3731         };
3732         u8 new_file_type;
3733         int retval;
3734
3735         if ((ext4_encrypted_inode(old_dir) &&
3736              !ext4_has_encryption_key(old_dir)) ||
3737             (ext4_encrypted_inode(new_dir) &&
3738              !ext4_has_encryption_key(new_dir)))
3739                 return -ENOKEY;
3740
3741         if ((ext4_encrypted_inode(old_dir) ||
3742              ext4_encrypted_inode(new_dir)) &&
3743             (old_dir != new_dir) &&
3744             (!ext4_is_child_context_consistent_with_parent(new_dir,
3745                                                            old.inode) ||
3746              !ext4_is_child_context_consistent_with_parent(old_dir,
3747                                                            new.inode)))
3748                 return -EXDEV;
3749
3750         retval = dquot_initialize(old.dir);
3751         if (retval)
3752                 return retval;
3753         retval = dquot_initialize(new.dir);
3754         if (retval)
3755                 return retval;
3756
3757         old.bh = ext4_find_entry(old.dir, &old.dentry->d_name,
3758                                  &old.de, &old.inlined);
3759         if (IS_ERR(old.bh))
3760                 return PTR_ERR(old.bh);
3761         /*
3762          *  Check for inode number is _not_ due to possible IO errors.
3763          *  We might rmdir the source, keep it as pwd of some process
3764          *  and merrily kill the link to whatever was created under the
3765          *  same name. Goodbye sticky bit ;-<
3766          */
3767         retval = -ENOENT;
3768         if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3769                 goto end_rename;
3770
3771         new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
3772                                  &new.de, &new.inlined);
3773         if (IS_ERR(new.bh)) {
3774                 retval = PTR_ERR(new.bh);
3775                 new.bh = NULL;
3776                 goto end_rename;
3777         }
3778
3779         /* RENAME_EXCHANGE case: old *and* new must both exist */
3780         if (!new.bh || le32_to_cpu(new.de->inode) != new.inode->i_ino)
3781                 goto end_rename;
3782
3783         handle = ext4_journal_start(old.dir, EXT4_HT_DIR,
3784                 (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3785                  2 * EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2));
3786         if (IS_ERR(handle)) {
3787                 retval = PTR_ERR(handle);
3788                 handle = NULL;
3789                 goto end_rename;
3790         }
3791
3792         if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3793                 ext4_handle_sync(handle);
3794
3795         if (S_ISDIR(old.inode->i_mode)) {
3796                 old.is_dir = true;
3797                 retval = ext4_rename_dir_prepare(handle, &old);
3798                 if (retval)
3799                         goto end_rename;
3800         }
3801         if (S_ISDIR(new.inode->i_mode)) {
3802                 new.is_dir = true;
3803                 retval = ext4_rename_dir_prepare(handle, &new);
3804                 if (retval)
3805                         goto end_rename;
3806         }
3807
3808         /*
3809          * Other than the special case of overwriting a directory, parents'
3810          * nlink only needs to be modified if this is a cross directory rename.
3811          */
3812         if (old.dir != new.dir && old.is_dir != new.is_dir) {
3813                 old.dir_nlink_delta = old.is_dir ? -1 : 1;
3814                 new.dir_nlink_delta = -old.dir_nlink_delta;
3815                 retval = -EMLINK;
3816                 if ((old.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(old.dir)) ||
3817                     (new.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(new.dir)))
3818                         goto end_rename;
3819         }
3820
3821         new_file_type = new.de->file_type;
3822         retval = ext4_setent(handle, &new, old.inode->i_ino, old.de->file_type);
3823         if (retval)
3824                 goto end_rename;
3825
3826         retval = ext4_setent(handle, &old, new.inode->i_ino, new_file_type);
3827         if (retval)
3828                 goto end_rename;
3829
3830         /*
3831          * Like most other Unix systems, set the ctime for inodes on a
3832          * rename.
3833          */
3834         old.inode->i_ctime = ext4_current_time(old.inode);
3835         new.inode->i_ctime = ext4_current_time(new.inode);
3836         ext4_mark_inode_dirty(handle, old.inode);
3837         ext4_mark_inode_dirty(handle, new.inode);
3838
3839         if (old.dir_bh) {
3840                 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
3841                 if (retval)
3842                         goto end_rename;
3843         }
3844         if (new.dir_bh) {
3845                 retval = ext4_rename_dir_finish(handle, &new, old.dir->i_ino);
3846                 if (retval)
3847                         goto end_rename;
3848         }
3849         ext4_update_dir_count(handle, &old);
3850         ext4_update_dir_count(handle, &new);
3851         retval = 0;
3852
3853 end_rename:
3854         brelse(old.dir_bh);
3855         brelse(new.dir_bh);
3856         brelse(old.bh);
3857         brelse(new.bh);
3858         if (handle)
3859                 ext4_journal_stop(handle);
3860         return retval;
3861 }
3862
3863 static int ext4_rename2(struct inode *old_dir, struct dentry *old_dentry,
3864                         struct inode *new_dir, struct dentry *new_dentry,
3865                         unsigned int flags)
3866 {
3867         if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
3868                 return -EINVAL;
3869
3870         if (flags & RENAME_EXCHANGE) {
3871                 return ext4_cross_rename(old_dir, old_dentry,
3872                                          new_dir, new_dentry);
3873         }
3874
3875         return ext4_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
3876 }
3877
3878 /*
3879  * directories can handle most operations...
3880  */
3881 const struct inode_operations ext4_dir_inode_operations = {
3882         .create         = ext4_create,
3883         .lookup         = ext4_lookup,
3884         .link           = ext4_link,
3885         .unlink         = ext4_unlink,
3886         .symlink        = ext4_symlink,
3887         .mkdir          = ext4_mkdir,
3888         .rmdir          = ext4_rmdir,
3889         .mknod          = ext4_mknod,
3890         .tmpfile        = ext4_tmpfile,
3891         .rename2        = ext4_rename2,
3892         .setattr        = ext4_setattr,
3893         .setxattr       = generic_setxattr,
3894         .getxattr       = generic_getxattr,
3895         .listxattr      = ext4_listxattr,
3896         .removexattr    = generic_removexattr,
3897         .get_acl        = ext4_get_acl,
3898         .set_acl        = ext4_set_acl,
3899         .fiemap         = ext4_fiemap,
3900 };
3901
3902 const struct inode_operations ext4_special_inode_operations = {
3903         .setattr        = ext4_setattr,
3904         .setxattr       = generic_setxattr,
3905         .getxattr       = generic_getxattr,
3906         .listxattr      = ext4_listxattr,
3907         .removexattr    = generic_removexattr,
3908         .get_acl        = ext4_get_acl,
3909         .set_acl        = ext4_set_acl,
3910 };