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/jbd2.h>
  30 #include <linux/time.h>
  31 #include <linux/fcntl.h>
  32 #include <linux/stat.h>
  33 #include <linux/string.h>
  34 #include <linux/quotaops.h>
  35 #include <linux/buffer_head.h>
  36 #include <linux/bio.h>
  37 #include "ext4.h"
  38 #include "ext4_jbd2.h"
  39
  40 #include "xattr.h"
  41 #include "acl.h"
  42
  43 #include <trace/events/ext4.h>
  44 /*
  45  * define how far ahead to read directories while searching them.
  46  */
  47 #define NAMEI_RA_CHUNKS  2
  48 #define NAMEI_RA_BLOCKS  4
  49 #define NAMEI_RA_SIZE        (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS)
  50 #define NAMEI_RA_INDEX(c,b)  (((c) * NAMEI_RA_BLOCKS) + (b))
  51
  52 static struct buffer_head *ext4_append(handle_t *handle,
  53                                         struct inode *inode,
  54                                         ext4_lblk_t *block, int *err)
  55 {
  56         struct buffer_head *bh;
  57
  58         if (unlikely(EXT4_SB(inode->i_sb)->s_max_dir_size_kb &&
  59                      ((inode->i_size >> 10) >=
  60                       EXT4_SB(inode->i_sb)->s_max_dir_size_kb))) {
  61                 *err = -ENOSPC;
  62                 return NULL;
  63         }
  64
  65         *block = inode->i_size >> inode->i_sb->s_blocksize_bits;
  66
  67         bh = ext4_bread(handle, inode, *block, 1, err);
  68         if (bh) {
  69                 inode->i_size += inode->i_sb->s_blocksize;
  70                 EXT4_I(inode)->i_disksize = inode->i_size;
  71                 *err = ext4_journal_get_write_access(handle, bh);
  72                 if (*err) {
  73                         brelse(bh);
  74                         bh = NULL;
  75                 }
  76         }
  77         if (!bh && !(*err)) {
  78                 *err = -EIO;
  79                 ext4_error(inode->i_sb,
  80                            "Directory hole detected on inode %lu\n",
  81                            inode->i_ino);
  82         }
  83         return bh;
  84 }
  85
  86 #ifndef assert
  87 #define assert(test) J_ASSERT(test)
  88 #endif
  89
  90 #ifdef DX_DEBUG
  91 #define dxtrace(command) command
  92 #else
  93 #define dxtrace(command)
  94 #endif
  95
  96 struct fake_dirent
  97 {
  98         __le32 inode;
  99         __le16 rec_len;
 100         u8 name_len;
 101         u8 file_type;
 102 };
 103
 104 struct dx_countlimit
 105 {
 106         __le16 limit;
 107         __le16 count;
 108 };
 109
 110 struct dx_entry
 111 {
 112         __le32 hash;
 113         __le32 block;
 114 };
 115
 116 /*
 117  * dx_root_info is laid out so that if it should somehow get overlaid by a
 118  * dirent the two low bits of the hash version will be zero.  Therefore, the
 119  * hash version mod 4 should never be 0.  Sincerely, the paranoia department.
 120  */
 121
 122 struct dx_root
 123 {
 124         struct fake_dirent dot;
 125         char dot_name[4];
 126         struct fake_dirent dotdot;
 127         char dotdot_name[4];
 128         struct dx_root_info
 129         {
 130                 __le32 reserved_zero;
 131                 u8 hash_version;
 132                 u8 info_length; /* 8 */
 133                 u8 indirect_levels;
 134                 u8 unused_flags;
 135         }
 136         info;
 137         struct dx_entry entries[0];
 138 };
 139
 140 struct dx_node
 141 {
 142         struct fake_dirent fake;
 143         struct dx_entry entries[0];
 144 };
 145
 146
 147 struct dx_frame
 148 {
 149         struct buffer_head *bh;
 150         struct dx_entry *entries;
 151         struct dx_entry *at;
 152 };
 153
 154 struct dx_map_entry
 155 {
 156         u32 hash;
 157         u16 offs;
 158         u16 size;
 159 };
 160
 161 /*
 162  * This goes at the end of each htree block.
 163  */
 164 struct dx_tail {
 165         u32 dt_reserved;
 166         __le32 dt_checksum;     /* crc32c(uuid+inum+dirblock) */
 167 };
 168
 169 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
 170 static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
 171 static inline unsigned dx_get_hash(struct dx_entry *entry);
 172 static void dx_set_hash(struct dx_entry *entry, unsigned value);
 173 static unsigned dx_get_count(struct dx_entry *entries);
 174 static unsigned dx_get_limit(struct dx_entry *entries);
 175 static void dx_set_count(struct dx_entry *entries, unsigned value);
 176 static void dx_set_limit(struct dx_entry *entries, unsigned value);
 177 static unsigned dx_root_limit(struct inode *dir, unsigned infosize);
 178 static unsigned dx_node_limit(struct inode *dir);
 179 static struct dx_frame *dx_probe(const struct qstr *d_name,
 180                                  struct inode *dir,
 181                                  struct dx_hash_info *hinfo,
 182                                  struct dx_frame *frame,
 183                                  int *err);
 184 static void dx_release(struct dx_frame *frames);
 185 static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize,
 186                        struct dx_hash_info *hinfo, struct dx_map_entry map[]);
 187 static void dx_sort_map(struct dx_map_entry *map, unsigned count);
 188 static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to,
 189                 struct dx_map_entry *offsets, int count, unsigned blocksize);
 190 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize);
 191 static void dx_insert_block(struct dx_frame *frame,
 192                                         u32 hash, ext4_lblk_t block);
 193 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
 194                                  struct dx_frame *frame,
 195                                  struct dx_frame *frames,
 196                                  __u32 *start_hash);
 197 static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
 198                 const struct qstr *d_name,
 199                 struct ext4_dir_entry_2 **res_dir,
 200                 int *err);
 201 static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
 202                              struct inode *inode);
 203
 204 /* checksumming functions */
 205 void initialize_dirent_tail(struct ext4_dir_entry_tail *t,
 206                             unsigned int blocksize)
 207 {
 208         memset(t, 0, sizeof(struct ext4_dir_entry_tail));
 209         t->det_rec_len = ext4_rec_len_to_disk(
 210                         sizeof(struct ext4_dir_entry_tail), blocksize);
 211         t->det_reserved_ft = EXT4_FT_DIR_CSUM;
 212 }
 213
 214 /* Walk through a dirent block to find a checksum "dirent" at the tail */
 215 static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode,
 216                                                    struct ext4_dir_entry *de)
 217 {
 218         struct ext4_dir_entry_tail *t;
 219
 220 #ifdef PARANOID
 221         struct ext4_dir_entry *d, *top;
 222
 223         d = de;
 224         top = (struct ext4_dir_entry *)(((void *)de) +
 225                 (EXT4_BLOCK_SIZE(inode->i_sb) -
 226                 sizeof(struct ext4_dir_entry_tail)));
 227         while (d < top && d->rec_len)
 228                 d = (struct ext4_dir_entry *)(((void *)d) +
 229                     le16_to_cpu(d->rec_len));
 230
 231         if (d != top)
 232                 return NULL;
 233
 234         t = (struct ext4_dir_entry_tail *)d;
 235 #else
 236         t = EXT4_DIRENT_TAIL(de, EXT4_BLOCK_SIZE(inode->i_sb));
 237 #endif
 238
 239         if (t->det_reserved_zero1 ||
 240             le16_to_cpu(t->det_rec_len) != sizeof(struct ext4_dir_entry_tail) ||
 241             t->det_reserved_zero2 ||
 242             t->det_reserved_ft != EXT4_FT_DIR_CSUM)
 243                 return NULL;
 244
 245         return t;
 246 }
 247
 248 static __le32 ext4_dirent_csum(struct inode *inode,
 249                                struct ext4_dir_entry *dirent, int size)
 250 {
 251         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
 252         struct ext4_inode_info *ei = EXT4_I(inode);
 253         __u32 csum;
 254
 255         csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
 256         return cpu_to_le32(csum);
 257 }
 258
 259 static void warn_no_space_for_csum(struct inode *inode)
 260 {
 261         ext4_warning(inode->i_sb, "no space in directory inode %lu leaf for "
 262                      "checksum.  Please run e2fsck -D.", inode->i_ino);
 263 }
 264
 265 int ext4_dirent_csum_verify(struct inode *inode, struct ext4_dir_entry *dirent)
 266 {
 267         struct ext4_dir_entry_tail *t;
 268
 269         if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
 270                                         EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 271                 return 1;
 272
 273         t = get_dirent_tail(inode, dirent);
 274         if (!t) {
 275                 warn_no_space_for_csum(inode);
 276                 return 0;
 277         }
 278
 279         if (t->det_checksum != ext4_dirent_csum(inode, dirent,
 280                                                 (void *)t - (void *)dirent))
 281                 return 0;
 282
 283         return 1;
 284 }
 285
 286 static void ext4_dirent_csum_set(struct inode *inode,
 287                                  struct ext4_dir_entry *dirent)
 288 {
 289         struct ext4_dir_entry_tail *t;
 290
 291         if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
 292                                         EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 293                 return;
 294
 295         t = get_dirent_tail(inode, dirent);
 296         if (!t) {
 297                 warn_no_space_for_csum(inode);
 298                 return;
 299         }
 300
 301         t->det_checksum = ext4_dirent_csum(inode, dirent,
 302                                            (void *)t - (void *)dirent);
 303 }
 304
 305 int ext4_handle_dirty_dirent_node(handle_t *handle,
 306                                   struct inode *inode,
 307                                   struct buffer_head *bh)
 308 {
 309         ext4_dirent_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
 310         return ext4_handle_dirty_metadata(handle, inode, bh);
 311 }
 312
 313 static struct dx_countlimit *get_dx_countlimit(struct inode *inode,
 314                                                struct ext4_dir_entry *dirent,
 315                                                int *offset)
 316 {
 317         struct ext4_dir_entry *dp;
 318         struct dx_root_info *root;
 319         int count_offset;
 320
 321         if (le16_to_cpu(dirent->rec_len) == EXT4_BLOCK_SIZE(inode->i_sb))
 322                 count_offset = 8;
 323         else if (le16_to_cpu(dirent->rec_len) == 12) {
 324                 dp = (struct ext4_dir_entry *)(((void *)dirent) + 12);
 325                 if (le16_to_cpu(dp->rec_len) !=
 326                     EXT4_BLOCK_SIZE(inode->i_sb) - 12)
 327                         return NULL;
 328                 root = (struct dx_root_info *)(((void *)dp + 12));
 329                 if (root->reserved_zero ||
 330                     root->info_length != sizeof(struct dx_root_info))
 331                         return NULL;
 332                 count_offset = 32;
 333         } else
 334                 return NULL;
 335
 336         if (offset)
 337                 *offset = count_offset;
 338         return (struct dx_countlimit *)(((void *)dirent) + count_offset);
 339 }
 340
 341 static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent,
 342                            int count_offset, int count, struct dx_tail *t)
 343 {
 344         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
 345         struct ext4_inode_info *ei = EXT4_I(inode);
 346         __u32 csum, old_csum;
 347         int size;
 348
 349         size = count_offset + (count * sizeof(struct dx_entry));
 350         old_csum = t->dt_checksum;
 351         t->dt_checksum = 0;
 352         csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
 353         csum = ext4_chksum(sbi, csum, (__u8 *)t, sizeof(struct dx_tail));
 354         t->dt_checksum = old_csum;
 355
 356         return cpu_to_le32(csum);
 357 }
 358
 359 static int ext4_dx_csum_verify(struct inode *inode,
 360                                struct ext4_dir_entry *dirent)
 361 {
 362         struct dx_countlimit *c;
 363         struct dx_tail *t;
 364         int count_offset, limit, count;
 365
 366         if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
 367                                         EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 368                 return 1;
 369
 370         c = get_dx_countlimit(inode, dirent, &count_offset);
 371         if (!c) {
 372                 EXT4_ERROR_INODE(inode, "dir seems corrupt?  Run e2fsck -D.");
 373                 return 1;
 374         }
 375         limit = le16_to_cpu(c->limit);
 376         count = le16_to_cpu(c->count);
 377         if (count_offset + (limit * sizeof(struct dx_entry)) >
 378             EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
 379                 warn_no_space_for_csum(inode);
 380                 return 1;
 381         }
 382         t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
 383
 384         if (t->dt_checksum != ext4_dx_csum(inode, dirent, count_offset,
 385                                             count, t))
 386                 return 0;
 387         return 1;
 388 }
 389
 390 static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent)
 391 {
 392         struct dx_countlimit *c;
 393         struct dx_tail *t;
 394         int count_offset, limit, count;
 395
 396         if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
 397                                         EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 398                 return;
 399
 400         c = get_dx_countlimit(inode, dirent, &count_offset);
 401         if (!c) {
 402                 EXT4_ERROR_INODE(inode, "dir seems corrupt?  Run e2fsck -D.");
 403                 return;
 404         }
 405         limit = le16_to_cpu(c->limit);
 406         count = le16_to_cpu(c->count);
 407         if (count_offset + (limit * sizeof(struct dx_entry)) >
 408             EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
 409                 warn_no_space_for_csum(inode);
 410                 return;
 411         }
 412         t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
 413
 414         t->dt_checksum = ext4_dx_csum(inode, dirent, count_offset, count, t);
 415 }
 416
 417 static inline int ext4_handle_dirty_dx_node(handle_t *handle,
 418                                             struct inode *inode,
 419                                             struct buffer_head *bh)
 420 {
 421         ext4_dx_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
 422         return ext4_handle_dirty_metadata(handle, inode, bh);
 423 }
 424
 425 /*
 426  * p is at least 6 bytes before the end of page
 427  */
 428 static inline struct ext4_dir_entry_2 *
 429 ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
 430 {
 431         return (struct ext4_dir_entry_2 *)((char *)p +
 432                 ext4_rec_len_from_disk(p->rec_len, blocksize));
 433 }
 434
 435 /*
 436  * Future: use high four bits of block for coalesce-on-delete flags
 437  * Mask them off for now.
 438  */
 439
 440 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
 441 {
 442         return le32_to_cpu(entry->block) & 0x00ffffff;
 443 }
 444
 445 static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
 446 {
 447         entry->block = cpu_to_le32(value);
 448 }
 449
 450 static inline unsigned dx_get_hash(struct dx_entry *entry)
 451 {
 452         return le32_to_cpu(entry->hash);
 453 }
 454
 455 static inline void dx_set_hash(struct dx_entry *entry, unsigned value)
 456 {
 457         entry->hash = cpu_to_le32(value);
 458 }
 459
 460 static inline unsigned dx_get_count(struct dx_entry *entries)
 461 {
 462         return le16_to_cpu(((struct dx_countlimit *) entries)->count);
 463 }
 464
 465 static inline unsigned dx_get_limit(struct dx_entry *entries)
 466 {
 467         return le16_to_cpu(((struct dx_countlimit *) entries)->limit);
 468 }
 469
 470 static inline void dx_set_count(struct dx_entry *entries, unsigned value)
 471 {
 472         ((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
 473 }
 474
 475 static inline void dx_set_limit(struct dx_entry *entries, unsigned value)
 476 {
 477         ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
 478 }
 479
 480 static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
 481 {
 482         unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
 483                 EXT4_DIR_REC_LEN(2) - infosize;
 484
 485         if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
 486                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 487                 entry_space -= sizeof(struct dx_tail);
 488         return entry_space / sizeof(struct dx_entry);
 489 }
 490
 491 static inline unsigned dx_node_limit(struct inode *dir)
 492 {
 493         unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);
 494
 495         if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
 496                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 497                 entry_space -= sizeof(struct dx_tail);
 498         return entry_space / sizeof(struct dx_entry);
 499 }
 500
 501 /*
 502  * Debug
 503  */
 504 #ifdef DX_DEBUG
 505 static void dx_show_index(char * label, struct dx_entry *entries)
 506 {
 507         int i, n = dx_get_count (entries);
 508         printk(KERN_DEBUG "%s index ", label);
 509         for (i = 0; i < n; i++) {
 510                 printk("%x->%lu ", i ? dx_get_hash(entries + i) :
 511                                 0, (unsigned long)dx_get_block(entries + i));
 512         }
 513         printk("\n");
 514 }
 515
 516 struct stats
 517 {
 518         unsigned names;
 519         unsigned space;
 520         unsigned bcount;
 521 };
 522
 523 static struct stats dx_show_leaf(struct dx_hash_info *hinfo, struct ext4_dir_entry_2 *de,
 524                                  int size, int show_names)
 525 {
 526         unsigned names = 0, space = 0;
 527         char *base = (char *) de;
 528         struct dx_hash_info h = *hinfo;
 529
 530         printk("names: ");
 531         while ((char *) de < base + size)
 532         {
 533                 if (de->inode)
 534                 {
 535                         if (show_names)
 536                         {
 537                                 int len = de->name_len;
 538                                 char *name = de->name;
 539                                 while (len--) printk("%c", *name++);
 540                                 ext4fs_dirhash(de->name, de->name_len, &h);
 541                                 printk(":%x.%u ", h.hash,
 542                                        (unsigned) ((char *) de - base));
 543                         }
 544                         space += EXT4_DIR_REC_LEN(de->name_len);
 545                         names++;
 546                 }
 547                 de = ext4_next_entry(de, size);
 548         }
 549         printk("(%i)\n", names);
 550         return (struct stats) { names, space, 1 };
 551 }
 552
 553 struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
 554                              struct dx_entry *entries, int levels)
 555 {
 556         unsigned blocksize = dir->i_sb->s_blocksize;
 557         unsigned count = dx_get_count(entries), names = 0, space = 0, i;
 558         unsigned bcount = 0;
 559         struct buffer_head *bh;
 560         int err;
 561         printk("%i indexed blocks...\n", count);
 562         for (i = 0; i < count; i++, entries++)
 563         {
 564                 ext4_lblk_t block = dx_get_block(entries);
 565                 ext4_lblk_t hash  = i ? dx_get_hash(entries): 0;
 566                 u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
 567                 struct stats stats;
 568                 printk("%s%3u:%03u hash %8x/%8x ",levels?"":"   ", i, block, hash, range);
 569                 if (!(bh = ext4_bread (NULL,dir, block, 0,&err))) continue;
 570                 stats = levels?
 571                    dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
 572                    dx_show_leaf(hinfo, (struct ext4_dir_entry_2 *) bh->b_data, blocksize, 0);
 573                 names += stats.names;
 574                 space += stats.space;
 575                 bcount += stats.bcount;
 576                 brelse(bh);
 577         }
 578         if (bcount)
 579                 printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n",
 580                        levels ? "" : "   ", names, space/bcount,
 581                        (space/bcount)*100/blocksize);
 582         return (struct stats) { names, space, bcount};
 583 }
 584 #endif /* DX_DEBUG */
 585
 586 /*
 587  * Probe for a directory leaf block to search.
 588  *
 589  * dx_probe can return ERR_BAD_DX_DIR, which means there was a format
 590  * error in the directory index, and the caller should fall back to
 591  * searching the directory normally.  The callers of dx_probe **MUST**
 592  * check for this error code, and make sure it never gets reflected
 593  * back to userspace.
 594  */
 595 static struct dx_frame *
 596 dx_probe(const struct qstr *d_name, struct inode *dir,
 597          struct dx_hash_info *hinfo, struct dx_frame *frame_in, int *err)
 598 {
 599         unsigned count, indirect;
 600         struct dx_entry *at, *entries, *p, *q, *m;
 601         struct dx_root *root;
 602         struct buffer_head *bh;
 603         struct dx_frame *frame = frame_in;
 604         u32 hash;
 605
 606         frame->bh = NULL;
 607         if (!(bh = ext4_bread(NULL, dir, 0, 0, err))) {
 608                 if (*err == 0)
 609                         *err = ERR_BAD_DX_DIR;
 610                 goto fail;
 611         }
 612         root = (struct dx_root *) bh->b_data;
 613         if (root->info.hash_version != DX_HASH_TEA &&
 614             root->info.hash_version != DX_HASH_HALF_MD4 &&
 615             root->info.hash_version != DX_HASH_LEGACY) {
 616                 ext4_warning(dir->i_sb, "Unrecognised inode hash code %d",
 617                              root->info.hash_version);
 618                 brelse(bh);
 619                 *err = ERR_BAD_DX_DIR;
 620                 goto fail;
 621         }
 622         hinfo->hash_version = root->info.hash_version;
 623         if (hinfo->hash_version <= DX_HASH_TEA)
 624                 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
 625         hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
 626         if (d_name)
 627                 ext4fs_dirhash(d_name->name, d_name->len, hinfo);
 628         hash = hinfo->hash;
 629
 630         if (root->info.unused_flags & 1) {
 631                 ext4_warning(dir->i_sb, "Unimplemented inode hash flags: %#06x",
 632                              root->info.unused_flags);
 633                 brelse(bh);
 634                 *err = ERR_BAD_DX_DIR;
 635                 goto fail;
 636         }
 637
 638         if ((indirect = root->info.indirect_levels) > 1) {
 639                 ext4_warning(dir->i_sb, "Unimplemented inode hash depth: %#06x",
 640                              root->info.indirect_levels);
 641                 brelse(bh);
 642                 *err = ERR_BAD_DX_DIR;
 643                 goto fail;
 644         }
 645
 646         if (!buffer_verified(bh) &&
 647             !ext4_dx_csum_verify(dir, (struct ext4_dir_entry *)bh->b_data)) {
 648                 ext4_warning(dir->i_sb, "Root failed checksum");
 649                 brelse(bh);
 650                 *err = ERR_BAD_DX_DIR;
 651                 goto fail;
 652         }
 653         set_buffer_verified(bh);
 654
 655         entries = (struct dx_entry *) (((char *)&root->info) +
 656                                        root->info.info_length);
 657
 658         if (dx_get_limit(entries) != dx_root_limit(dir,
 659                                                    root->info.info_length)) {
 660                 ext4_warning(dir->i_sb, "dx entry: limit != root limit");
 661                 brelse(bh);
 662                 *err = ERR_BAD_DX_DIR;
 663                 goto fail;
 664         }
 665
 666         dxtrace(printk("Look up %x", hash));
 667         while (1)
 668         {
 669                 count = dx_get_count(entries);
 670                 if (!count || count > dx_get_limit(entries)) {
 671                         ext4_warning(dir->i_sb,
 672                                      "dx entry: no count or count > limit");
 673                         brelse(bh);
 674                         *err = ERR_BAD_DX_DIR;
 675                         goto fail2;
 676                 }
 677
 678                 p = entries + 1;
 679                 q = entries + count - 1;
 680                 while (p <= q)
 681                 {
 682                         m = p + (q - p)/2;
 683                         dxtrace(printk("."));
 684                         if (dx_get_hash(m) > hash)
 685                                 q = m - 1;
 686                         else
 687                                 p = m + 1;
 688                 }
 689
 690                 if (0) // linear search cross check
 691                 {
 692                         unsigned n = count - 1;
 693                         at = entries;
 694                         while (n--)
 695                         {
 696                                 dxtrace(printk(","));
 697                                 if (dx_get_hash(++at) > hash)
 698                                 {
 699                                         at--;
 700                                         break;
 701                                 }
 702                         }
 703                         assert (at == p - 1);
 704                 }
 705
 706                 at = p - 1;
 707                 dxtrace(printk(" %x->%u\n", at == entries? 0: dx_get_hash(at), dx_get_block(at)));
 708                 frame->bh = bh;
 709                 frame->entries = entries;
 710                 frame->at = at;
 711                 if (!indirect--) return frame;
 712                 if (!(bh = ext4_bread(NULL, dir, dx_get_block(at), 0, err))) {
 713                         if (!(*err))
 714                                 *err = ERR_BAD_DX_DIR;
 715                         goto fail2;
 716                 }
 717                 at = entries = ((struct dx_node *) bh->b_data)->entries;
 718
 719                 if (!buffer_verified(bh) &&
 720                     !ext4_dx_csum_verify(dir,
 721                                          (struct ext4_dir_entry *)bh->b_data)) {
 722                         ext4_warning(dir->i_sb, "Node failed checksum");
 723                         brelse(bh);
 724                         *err = ERR_BAD_DX_DIR;
 725                         goto fail2;
 726                 }
 727                 set_buffer_verified(bh);
 728
 729                 if (dx_get_limit(entries) != dx_node_limit (dir)) {
 730                         ext4_warning(dir->i_sb,
 731                                      "dx entry: limit != node limit");
 732                         brelse(bh);
 733                         *err = ERR_BAD_DX_DIR;
 734                         goto fail2;
 735                 }
 736                 frame++;
 737                 frame->bh = NULL;
 738         }
 739 fail2:
 740         while (frame >= frame_in) {
 741                 brelse(frame->bh);
 742                 frame--;
 743         }
 744 fail:
 745         if (*err == ERR_BAD_DX_DIR)
 746                 ext4_warning(dir->i_sb,
 747                              "Corrupt dir inode %lu, running e2fsck is "
 748                              "recommended.", dir->i_ino);
 749         return NULL;
 750 }
 751
 752 static void dx_release (struct dx_frame *frames)
 753 {
 754         if (frames[0].bh == NULL)
 755                 return;
 756
 757         if (((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels)
 758                 brelse(frames[1].bh);
 759         brelse(frames[0].bh);
 760 }
 761
 762 /*
 763  * This function increments the frame pointer to search the next leaf
 764  * block, and reads in the necessary intervening nodes if the search
 765  * should be necessary.  Whether or not the search is necessary is
 766  * controlled by the hash parameter.  If the hash value is even, then
 767  * the search is only continued if the next block starts with that
 768  * hash value.  This is used if we are searching for a specific file.
 769  *
 770  * If the hash value is HASH_NB_ALWAYS, then always go to the next block.
 771  *
 772  * This function returns 1 if the caller should continue to search,
 773  * or 0 if it should not.  If there is an error reading one of the
 774  * index blocks, it will a negative error code.
 775  *
 776  * If start_hash is non-null, it will be filled in with the starting
 777  * hash of the next page.
 778  */
 779 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
 780                                  struct dx_frame *frame,
 781                                  struct dx_frame *frames,
 782                                  __u32 *start_hash)
 783 {
 784         struct dx_frame *p;
 785         struct buffer_head *bh;
 786         int err, num_frames = 0;
 787         __u32 bhash;
 788
 789         p = frame;
 790         /*
 791          * Find the next leaf page by incrementing the frame pointer.
 792          * If we run out of entries in the interior node, loop around and
 793          * increment pointer in the parent node.  When we break out of
 794          * this loop, num_frames indicates the number of interior
 795          * nodes need to be read.
 796          */
 797         while (1) {
 798                 if (++(p->at) < p->entries + dx_get_count(p->entries))
 799                         break;
 800                 if (p == frames)
 801                         return 0;
 802                 num_frames++;
 803                 p--;
 804         }
 805
 806         /*
 807          * If the hash is 1, then continue only if the next page has a
 808          * continuation hash of any value.  This is used for readdir
 809          * handling.  Otherwise, check to see if the hash matches the
 810          * desired contiuation hash.  If it doesn't, return since
 811          * there's no point to read in the successive index pages.
 812          */
 813         bhash = dx_get_hash(p->at);
 814         if (start_hash)
 815                 *start_hash = bhash;
 816         if ((hash & 1) == 0) {
 817                 if ((bhash & ~1) != hash)
 818                         return 0;
 819         }
 820         /*
 821          * If the hash is HASH_NB_ALWAYS, we always go to the next
 822          * block so no check is necessary
 823          */
 824         while (num_frames--) {
 825                 if (!(bh = ext4_bread(NULL, dir, dx_get_block(p->at),
 826                                       0, &err))) {
 827                         if (!err) {
 828                                 ext4_error(dir->i_sb,
 829                                            "Directory hole detected on inode %lu\n",
 830                                            dir->i_ino);
 831                                 return -EIO;
 832                         }
 833                         return err; /* Failure */
 834                 }
 835
 836                 if (!buffer_verified(bh) &&
 837                     !ext4_dx_csum_verify(dir,
 838                                          (struct ext4_dir_entry *)bh->b_data)) {
 839                         ext4_warning(dir->i_sb, "Node failed checksum");
 840                         return -EIO;
 841                 }
 842                 set_buffer_verified(bh);
 843
 844                 p++;
 845                 brelse(p->bh);
 846                 p->bh = bh;
 847                 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
 848         }
 849         return 1;
 850 }
 851
 852
 853 /*
 854  * This function fills a red-black tree with information from a
 855  * directory block.  It returns the number directory entries loaded
 856  * into the tree.  If there is an error it is returned in err.
 857  */
 858 static int htree_dirblock_to_tree(struct file *dir_file,
 859                                   struct inode *dir, ext4_lblk_t block,
 860                                   struct dx_hash_info *hinfo,
 861                                   __u32 start_hash, __u32 start_minor_hash)
 862 {
 863         struct buffer_head *bh;
 864         struct ext4_dir_entry_2 *de, *top;
 865         int err = 0, count = 0;
 866
 867         dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
 868                                                         (unsigned long)block));
 869         if (!(bh = ext4_bread(NULL, dir, block, 0, &err))) {
 870                 if (!err) {
 871                         err = -EIO;
 872                         ext4_error(dir->i_sb,
 873                                    "Directory hole detected on inode %lu\n",
 874                                    dir->i_ino);
 875                 }
 876                 return err;
 877         }
 878
 879         if (!buffer_verified(bh) &&
 880             !ext4_dirent_csum_verify(dir, (struct ext4_dir_entry *)bh->b_data))
 881                 return -EIO;
 882         set_buffer_verified(bh);
 883
 884         de = (struct ext4_dir_entry_2 *) bh->b_data;
 885         top = (struct ext4_dir_entry_2 *) ((char *) de +
 886                                            dir->i_sb->s_blocksize -
 887                                            EXT4_DIR_REC_LEN(0));
 888         for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) {
 889                 if (ext4_check_dir_entry(dir, NULL, de, bh,
 890                                 bh->b_data, bh->b_size,
 891                                 (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
 892                                          + ((char *)de - bh->b_data))) {
 893                         /* On error, skip the f_pos to the next block. */
 894                         dir_file->f_pos = (dir_file->f_pos |
 895                                         (dir->i_sb->s_blocksize - 1)) + 1;
 896                         brelse(bh);
 897                         return count;
 898                 }
 899                 ext4fs_dirhash(de->name, de->name_len, hinfo);
 900                 if ((hinfo->hash < start_hash) ||
 901                     ((hinfo->hash == start_hash) &&
 902                      (hinfo->minor_hash < start_minor_hash)))
 903                         continue;
 904                 if (de->inode == 0)
 905                         continue;
 906                 if ((err = ext4_htree_store_dirent(dir_file,
 907                                    hinfo->hash, hinfo->minor_hash, de)) != 0) {
 908                         brelse(bh);
 909                         return err;
 910                 }
 911                 count++;
 912         }
 913         brelse(bh);
 914         return count;
 915 }
 916
 917
 918 /*
 919  * This function fills a red-black tree with information from a
 920  * directory.  We start scanning the directory in hash order, starting
 921  * at start_hash and start_minor_hash.
 922  *
 923  * This function returns the number of entries inserted into the tree,
 924  * or a negative error code.
 925  */
 926 int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
 927                          __u32 start_minor_hash, __u32 *next_hash)
 928 {
 929         struct dx_hash_info hinfo;
 930         struct ext4_dir_entry_2 *de;
 931         struct dx_frame frames[2], *frame;
 932         struct inode *dir;
 933         ext4_lblk_t block;
 934         int count = 0;
 935         int ret, err;
 936         __u32 hashval;
 937
 938         dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
 939                        start_hash, start_minor_hash));
 940         dir = dir_file->f_path.dentry->d_inode;
 941         if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) {
 942                 hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
 943                 if (hinfo.hash_version <= DX_HASH_TEA)
 944                         hinfo.hash_version +=
 945                                 EXT4_SB(dir->i_sb)->s_hash_unsigned;
 946                 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
 947                 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
 948                                                start_hash, start_minor_hash);
 949                 *next_hash = ~0;
 950                 return count;
 951         }
 952         hinfo.hash = start_hash;
 953         hinfo.minor_hash = 0;
 954         frame = dx_probe(NULL, dir, &hinfo, frames, &err);
 955         if (!frame)
 956                 return err;
 957
 958         /* Add '.' and '..' from the htree header */
 959         if (!start_hash && !start_minor_hash) {
 960                 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
 961                 if ((err = ext4_htree_store_dirent(dir_file, 0, 0, de)) != 0)
 962                         goto errout;
 963                 count++;
 964         }
 965         if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
 966                 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
 967                 de = ext4_next_entry(de, dir->i_sb->s_blocksize);
 968                 if ((err = ext4_htree_store_dirent(dir_file, 2, 0, de)) != 0)
 969                         goto errout;
 970                 count++;
 971         }
 972
 973         while (1) {
 974                 block = dx_get_block(frame->at);
 975                 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
 976                                              start_hash, start_minor_hash);
 977                 if (ret < 0) {
 978                         err = ret;
 979                         goto errout;
 980                 }
 981                 count += ret;
 982                 hashval = ~0;
 983                 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
 984                                             frame, frames, &hashval);
 985                 *next_hash = hashval;
 986                 if (ret < 0) {
 987                         err = ret;
 988                         goto errout;
 989                 }
 990                 /*
 991                  * Stop if:  (a) there are no more entries, or
 992                  * (b) we have inserted at least one entry and the
 993                  * next hash value is not a continuation
 994                  */
 995                 if ((ret == 0) ||
 996                     (count && ((hashval & 1) == 0)))
 997                         break;
 998         }
 999         dx_release(frames);
1000         dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, "
1001                        "next hash: %x\n", count, *next_hash));
1002         return count;
1003 errout:
1004         dx_release(frames);
1005         return (err);
1006 }
1007
1008 static inline int search_dirblock(struct buffer_head *bh,
1009                                   struct inode *dir,
1010                                   const struct qstr *d_name,
1011                                   unsigned int offset,
1012                                   struct ext4_dir_entry_2 **res_dir)
1013 {
1014         return search_dir(bh, bh->b_data, dir->i_sb->s_blocksize, dir,
1015                           d_name, offset, res_dir);
1016 }
1017
1018 /*
1019  * Directory block splitting, compacting
1020  */
1021
1022 /*
1023  * Create map of hash values, offsets, and sizes, stored at end of block.
1024  * Returns number of entries mapped.
1025  */
1026 static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize,
1027                        struct dx_hash_info *hinfo,
1028                        struct dx_map_entry *map_tail)
1029 {
1030         int count = 0;
1031         char *base = (char *) de;
1032         struct dx_hash_info h = *hinfo;
1033
1034         while ((char *) de < base + blocksize) {
1035                 if (de->name_len && de->inode) {
1036                         ext4fs_dirhash(de->name, de->name_len, &h);
1037                         map_tail--;
1038                         map_tail->hash = h.hash;
1039                         map_tail->offs = ((char *) de - base)>>2;
1040                         map_tail->size = le16_to_cpu(de->rec_len);
1041                         count++;
1042                         cond_resched();
1043                 }
1044                 /* XXX: do we need to check rec_len == 0 case? -Chris */
1045                 de = ext4_next_entry(de, blocksize);
1046         }
1047         return count;
1048 }
1049
1050 /* Sort map by hash value */
1051 static void dx_sort_map (struct dx_map_entry *map, unsigned count)
1052 {
1053         struct dx_map_entry *p, *q, *top = map + count - 1;
1054         int more;
1055         /* Combsort until bubble sort doesn't suck */
1056         while (count > 2) {
1057                 count = count*10/13;
1058                 if (count - 9 < 2) /* 9, 10 -> 11 */
1059                         count = 11;
1060                 for (p = top, q = p - count; q >= map; p--, q--)
1061                         if (p->hash < q->hash)
1062                                 swap(*p, *q);
1063         }
1064         /* Garden variety bubble sort */
1065         do {
1066                 more = 0;
1067                 q = top;
1068                 while (q-- > map) {
1069                         if (q[1].hash >= q[0].hash)
1070                                 continue;
1071                         swap(*(q+1), *q);
1072                         more = 1;
1073                 }
1074         } while(more);
1075 }
1076
1077 static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
1078 {
1079         struct dx_entry *entries = frame->entries;
1080         struct dx_entry *old = frame->at, *new = old + 1;
1081         int count = dx_get_count(entries);
1082
1083         assert(count < dx_get_limit(entries));
1084         assert(old < entries + count);
1085         memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
1086         dx_set_hash(new, hash);
1087         dx_set_block(new, block);
1088         dx_set_count(entries, count + 1);
1089 }
1090
1091 /*
1092  * NOTE! unlike strncmp, ext4_match returns 1 for success, 0 for failure.
1093  *
1094  * `len <= EXT4_NAME_LEN' is guaranteed by caller.
1095  * `de != NULL' is guaranteed by caller.
1096  */
1097 static inline int ext4_match (int len, const char * const name,
1098                               struct ext4_dir_entry_2 * de)
1099 {
1100         if (len != de->name_len)
1101                 return 0;
1102         if (!de->inode)
1103                 return 0;
1104         return !memcmp(name, de->name, len);
1105 }
1106
1107 /*
1108  * Returns 0 if not found, -1 on failure, and 1 on success
1109  */
1110 int search_dir(struct buffer_head *bh,
1111                char *search_buf,
1112                int buf_size,
1113                struct inode *dir,
1114                const struct qstr *d_name,
1115                unsigned int offset,
1116                struct ext4_dir_entry_2 **res_dir)
1117 {
1118         struct ext4_dir_entry_2 * de;
1119         char * dlimit;
1120         int de_len;
1121         const char *name = d_name->name;
1122         int namelen = d_name->len;
1123
1124         de = (struct ext4_dir_entry_2 *)search_buf;
1125         dlimit = search_buf + buf_size;
1126         while ((char *) de < dlimit) {
1127                 /* this code is executed quadratically often */
1128                 /* do minimal checking `by hand' */
1129
1130                 if ((char *) de + namelen <= dlimit &&
1131                     ext4_match (namelen, name, de)) {
1132                         /* found a match - just to be sure, do a full check */
1133                         if (ext4_check_dir_entry(dir, NULL, de, bh, bh->b_data,
1134                                                  bh->b_size, offset))
1135                                 return -1;
1136                         *res_dir = de;
1137                         return 1;
1138                 }
1139                 /* prevent looping on a bad block */
1140                 de_len = ext4_rec_len_from_disk(de->rec_len,
1141                                                 dir->i_sb->s_blocksize);
1142                 if (de_len <= 0)
1143                         return -1;
1144                 offset += de_len;
1145                 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
1146         }
1147         return 0;
1148 }
1149
1150 static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block,
1151                                struct ext4_dir_entry *de)
1152 {
1153         struct super_block *sb = dir->i_sb;
1154
1155         if (!is_dx(dir))
1156                 return 0;
1157         if (block == 0)
1158                 return 1;
1159         if (de->inode == 0 &&
1160             ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) ==
1161                         sb->s_blocksize)
1162                 return 1;
1163         return 0;
1164 }
1165
1166 /*
1167  *      ext4_find_entry()
1168  *
1169  * finds an entry in the specified directory with the wanted name. It
1170  * returns the cache buffer in which the entry was found, and the entry
1171  * itself (as a parameter - res_dir). It does NOT read the inode of the
1172  * entry - you'll have to do that yourself if you want to.
1173  *
1174  * The returned buffer_head has ->b_count elevated.  The caller is expected
1175  * to brelse() it when appropriate.
1176  */
1177 static struct buffer_head * ext4_find_entry (struct inode *dir,
1178                                         const struct qstr *d_name,
1179                                         struct ext4_dir_entry_2 **res_dir,
1180                                         int *inlined)
1181 {
1182         struct super_block *sb;
1183         struct buffer_head *bh_use[NAMEI_RA_SIZE];
1184         struct buffer_head *bh, *ret = NULL;
1185         ext4_lblk_t start, block, b;
1186         const u8 *name = d_name->name;
1187         int ra_max = 0;         /* Number of bh's in the readahead
1188                                    buffer, bh_use[] */
1189         int ra_ptr = 0;         /* Current index into readahead
1190                                    buffer */
1191         int num = 0;
1192         ext4_lblk_t  nblocks;
1193         int i, err;
1194         int namelen;
1195
1196         *res_dir = NULL;
1197         sb = dir->i_sb;
1198         namelen = d_name->len;
1199         if (namelen > EXT4_NAME_LEN)
1200                 return NULL;
1201
1202         if (ext4_has_inline_data(dir)) {
1203                 int has_inline_data = 1;
1204                 ret = ext4_find_inline_entry(dir, d_name, res_dir,
1205                                              &has_inline_data);
1206                 if (has_inline_data) {
1207                         if (inlined)
1208                                 *inlined = 1;
1209                         return ret;
1210                 }
1211         }
1212
1213         if ((namelen <= 2) && (name[0] == '.') &&
1214             (name[1] == '.' || name[1] == '\0')) {
1215                 /*
1216                  * "." or ".." will only be in the first block
1217                  * NFS may look up ".."; "." should be handled by the VFS
1218                  */
1219                 block = start = 0;
1220                 nblocks = 1;
1221                 goto restart;
1222         }
1223         if (is_dx(dir)) {
1224                 bh = ext4_dx_find_entry(dir, d_name, res_dir, &err);
1225                 /*
1226                  * On success, or if the error was file not found,
1227                  * return.  Otherwise, fall back to doing a search the
1228                  * old fashioned way.
1229                  */
1230                 if (bh || (err != ERR_BAD_DX_DIR))
1231                         return bh;
1232                 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
1233                                "falling back\n"));
1234         }
1235         nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1236         start = EXT4_I(dir)->i_dir_start_lookup;
1237         if (start >= nblocks)
1238                 start = 0;
1239         block = start;
1240 restart:
1241         do {
1242                 /*
1243                  * We deal with the read-ahead logic here.
1244                  */
1245                 if (ra_ptr >= ra_max) {
1246                         /* Refill the readahead buffer */
1247                         ra_ptr = 0;
1248                         b = block;
1249                         for (ra_max = 0; ra_max < NAMEI_RA_SIZE; ra_max++) {
1250                                 /*
1251                                  * Terminate if we reach the end of the
1252                                  * directory and must wrap, or if our
1253                                  * search has finished at this block.
1254                                  */
1255                                 if (b >= nblocks || (num && block == start)) {
1256                                         bh_use[ra_max] = NULL;
1257                                         break;
1258                                 }
1259                                 num++;
1260                                 bh = ext4_getblk(NULL, dir, b++, 0, &err);
1261                                 bh_use[ra_max] = bh;
1262                                 if (bh)
1263                                         ll_rw_block(READ | REQ_META | REQ_PRIO,
1264                                                     1, &bh);
1265                         }
1266                 }
1267                 if ((bh = bh_use[ra_ptr++]) == NULL)
1268                         goto next;
1269                 wait_on_buffer(bh);
1270                 if (!buffer_uptodate(bh)) {
1271                         /* read error, skip block & hope for the best */
1272                         EXT4_ERROR_INODE(dir, "reading directory lblock %lu",
1273                                          (unsigned long) block);
1274                         brelse(bh);
1275                         goto next;
1276                 }
1277                 if (!buffer_verified(bh) &&
1278                     !is_dx_internal_node(dir, block,
1279                                          (struct ext4_dir_entry *)bh->b_data) &&
1280                     !ext4_dirent_csum_verify(dir,
1281                                 (struct ext4_dir_entry *)bh->b_data)) {
1282                         EXT4_ERROR_INODE(dir, "checksumming directory "
1283                                          "block %lu", (unsigned long)block);
1284                         brelse(bh);
1285                         goto next;
1286                 }
1287                 set_buffer_verified(bh);
1288                 i = search_dirblock(bh, dir, d_name,
1289                             block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
1290                 if (i == 1) {
1291                         EXT4_I(dir)->i_dir_start_lookup = block;
1292                         ret = bh;
1293                         goto cleanup_and_exit;
1294                 } else {
1295                         brelse(bh);
1296                         if (i < 0)
1297                                 goto cleanup_and_exit;
1298                 }
1299         next:
1300                 if (++block >= nblocks)
1301                         block = 0;
1302         } while (block != start);
1303
1304         /*
1305          * If the directory has grown while we were searching, then
1306          * search the last part of the directory before giving up.
1307          */
1308         block = nblocks;
1309         nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1310         if (block < nblocks) {
1311                 start = 0;
1312                 goto restart;
1313         }
1314
1315 cleanup_and_exit:
1316         /* Clean up the read-ahead blocks */
1317         for (; ra_ptr < ra_max; ra_ptr++)
1318                 brelse(bh_use[ra_ptr]);
1319         return ret;
1320 }
1321
1322 static struct buffer_head * ext4_dx_find_entry(struct inode *dir, const struct qstr *d_name,
1323                        struct ext4_dir_entry_2 **res_dir, int *err)
1324 {
1325         struct super_block * sb = dir->i_sb;
1326         struct dx_hash_info     hinfo;
1327         struct dx_frame frames[2], *frame;
1328         struct buffer_head *bh;
1329         ext4_lblk_t block;
1330         int retval;
1331
1332         if (!(frame = dx_probe(d_name, dir, &hinfo, frames, err)))
1333                 return NULL;
1334         do {
1335                 block = dx_get_block(frame->at);
1336                 if (!(bh = ext4_bread(NULL, dir, block, 0, err))) {
1337                         if (!(*err)) {
1338                                 *err = -EIO;
1339                                 ext4_error(dir->i_sb,
1340                                            "Directory hole detected on inode %lu\n",
1341                                            dir->i_ino);
1342                         }
1343                         goto errout;
1344                 }
1345
1346                 if (!buffer_verified(bh) &&
1347                     !ext4_dirent_csum_verify(dir,
1348                                 (struct ext4_dir_entry *)bh->b_data)) {
1349                         EXT4_ERROR_INODE(dir, "checksumming directory "
1350                                          "block %lu", (unsigned long)block);
1351                         brelse(bh);
1352                         *err = -EIO;
1353                         goto errout;
1354                 }
1355                 set_buffer_verified(bh);
1356                 retval = search_dirblock(bh, dir, d_name,
1357                                          block << EXT4_BLOCK_SIZE_BITS(sb),
1358                                          res_dir);
1359                 if (retval == 1) {      /* Success! */
1360                         dx_release(frames);
1361                         return bh;
1362                 }
1363                 brelse(bh);
1364                 if (retval == -1) {
1365                         *err = ERR_BAD_DX_DIR;
1366                         goto errout;
1367                 }
1368
1369                 /* Check to see if we should continue to search */
1370                 retval = ext4_htree_next_block(dir, hinfo.hash, frame,
1371                                                frames, NULL);
1372                 if (retval < 0) {
1373                         ext4_warning(sb,
1374                              "error reading index page in directory #%lu",
1375                              dir->i_ino);
1376                         *err = retval;
1377                         goto errout;
1378                 }
1379         } while (retval == 1);
1380
1381         *err = -ENOENT;
1382 errout:
1383         dxtrace(printk(KERN_DEBUG "%s not found\n", d_name->name));
1384         dx_release (frames);
1385         return NULL;
1386 }
1387
1388 static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
1389 {
1390         struct inode *inode;
1391         struct ext4_dir_entry_2 *de;
1392         struct buffer_head *bh;
1393
1394         if (dentry->d_name.len > EXT4_NAME_LEN)
1395                 return ERR_PTR(-ENAMETOOLONG);
1396
1397         bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
1398         inode = NULL;
1399         if (bh) {
1400                 __u32 ino = le32_to_cpu(de->inode);
1401                 brelse(bh);
1402                 if (!ext4_valid_inum(dir->i_sb, ino)) {
1403                         EXT4_ERROR_INODE(dir, "bad inode number: %u", ino);
1404                         return ERR_PTR(-EIO);
1405                 }
1406                 if (unlikely(ino == dir->i_ino)) {
1407                         EXT4_ERROR_INODE(dir, "'%.*s' linked to parent dir",
1408                                          dentry->d_name.len,
1409                                          dentry->d_name.name);
1410                         return ERR_PTR(-EIO);
1411                 }
1412                 inode = ext4_iget(dir->i_sb, ino);
1413                 if (inode == ERR_PTR(-ESTALE)) {
1414                         EXT4_ERROR_INODE(dir,
1415                                          "deleted inode referenced: %u",
1416                                          ino);
1417                         return ERR_PTR(-EIO);
1418                 }
1419         }
1420         return d_splice_alias(inode, dentry);
1421 }
1422
1423
1424 struct dentry *ext4_get_parent(struct dentry *child)
1425 {
1426         __u32 ino;
1427         static const struct qstr dotdot = QSTR_INIT("..", 2);
1428         struct ext4_dir_entry_2 * de;
1429         struct buffer_head *bh;
1430
1431         bh = ext4_find_entry(child->d_inode, &dotdot, &de, NULL);
1432         if (!bh)
1433                 return ERR_PTR(-ENOENT);
1434         ino = le32_to_cpu(de->inode);
1435         brelse(bh);
1436
1437         if (!ext4_valid_inum(child->d_inode->i_sb, ino)) {
1438                 EXT4_ERROR_INODE(child->d_inode,
1439                                  "bad parent inode number: %u", ino);
1440                 return ERR_PTR(-EIO);
1441         }
1442
1443         return d_obtain_alias(ext4_iget(child->d_inode->i_sb, ino));
1444 }
1445
1446 #define S_SHIFT 12
1447 static unsigned char ext4_type_by_mode[S_IFMT >> S_SHIFT] = {
1448         [S_IFREG >> S_SHIFT]    = EXT4_FT_REG_FILE,
1449         [S_IFDIR >> S_SHIFT]    = EXT4_FT_DIR,
1450         [S_IFCHR >> S_SHIFT]    = EXT4_FT_CHRDEV,
1451         [S_IFBLK >> S_SHIFT]    = EXT4_FT_BLKDEV,
1452         [S_IFIFO >> S_SHIFT]    = EXT4_FT_FIFO,
1453         [S_IFSOCK >> S_SHIFT]   = EXT4_FT_SOCK,
1454         [S_IFLNK >> S_SHIFT]    = EXT4_FT_SYMLINK,
1455 };
1456
1457 static inline void ext4_set_de_type(struct super_block *sb,
1458                                 struct ext4_dir_entry_2 *de,
1459                                 umode_t mode) {
1460         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE))
1461                 de->file_type = ext4_type_by_mode[(mode & S_IFMT)>>S_SHIFT];
1462 }
1463
1464 /*
1465  * Move count entries from end of map between two memory locations.
1466  * Returns pointer to last entry moved.
1467  */
1468 static struct ext4_dir_entry_2 *
1469 dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count,
1470                 unsigned blocksize)
1471 {
1472         unsigned rec_len = 0;
1473
1474         while (count--) {
1475                 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
1476                                                 (from + (map->offs<<2));
1477                 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1478                 memcpy (to, de, rec_len);
1479                 ((struct ext4_dir_entry_2 *) to)->rec_len =
1480                                 ext4_rec_len_to_disk(rec_len, blocksize);
1481                 de->inode = 0;
1482                 map++;
1483                 to += rec_len;
1484         }
1485         return (struct ext4_dir_entry_2 *) (to - rec_len);
1486 }
1487
1488 /*
1489  * Compact each dir entry in the range to the minimal rec_len.
1490  * Returns pointer to last entry in range.
1491  */
1492 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize)
1493 {
1494         struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
1495         unsigned rec_len = 0;
1496
1497         prev = to = de;
1498         while ((char*)de < base + blocksize) {
1499                 next = ext4_next_entry(de, blocksize);
1500                 if (de->inode && de->name_len) {
1501                         rec_len = EXT4_DIR_REC_LEN(de->name_len);
1502                         if (de > to)
1503                                 memmove(to, de, rec_len);
1504                         to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
1505                         prev = to;
1506                         to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
1507                 }
1508                 de = next;
1509         }
1510         return prev;
1511 }
1512
1513 /*
1514  * Split a full leaf block to make room for a new dir entry.
1515  * Allocate a new block, and move entries so that they are approx. equally full.
1516  * Returns pointer to de in block into which the new entry will be inserted.
1517  */
1518 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
1519                         struct buffer_head **bh,struct dx_frame *frame,
1520                         struct dx_hash_info *hinfo, int *error)
1521 {
1522         unsigned blocksize = dir->i_sb->s_blocksize;
1523         unsigned count, continued;
1524         struct buffer_head *bh2;
1525         ext4_lblk_t newblock;
1526         u32 hash2;
1527         struct dx_map_entry *map;
1528         char *data1 = (*bh)->b_data, *data2;
1529         unsigned split, move, size;
1530         struct ext4_dir_entry_2 *de = NULL, *de2;
1531         struct ext4_dir_entry_tail *t;
1532         int     csum_size = 0;
1533         int     err = 0, i;
1534
1535         if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
1536                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
1537                 csum_size = sizeof(struct ext4_dir_entry_tail);
1538
1539         bh2 = ext4_append (handle, dir, &newblock, &err);
1540         if (!(bh2)) {
1541                 brelse(*bh);
1542                 *bh = NULL;
1543                 goto errout;
1544         }
1545
1546         BUFFER_TRACE(*bh, "get_write_access");
1547         err = ext4_journal_get_write_access(handle, *bh);
1548         if (err)
1549                 goto journal_error;
1550
1551         BUFFER_TRACE(frame->bh, "get_write_access");
1552         err = ext4_journal_get_write_access(handle, frame->bh);
1553         if (err)
1554                 goto journal_error;
1555
1556         data2 = bh2->b_data;
1557
1558         /* create map in the end of data2 block */
1559         map = (struct dx_map_entry *) (data2 + blocksize);
1560         count = dx_make_map((struct ext4_dir_entry_2 *) data1,
1561                              blocksize, hinfo, map);
1562         map -= count;
1563         dx_sort_map(map, count);
1564         /* Split the existing block in the middle, size-wise */
1565         size = 0;
1566         move = 0;
1567         for (i = count-1; i >= 0; i--) {
1568                 /* is more than half of this entry in 2nd half of the block? */
1569                 if (size + map[i].size/2 > blocksize/2)
1570                         break;
1571                 size += map[i].size;
1572                 move++;
1573         }
1574         /* map index at which we will split */
1575         split = count - move;
1576         hash2 = map[split].hash;
1577         continued = hash2 == map[split - 1].hash;
1578         dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
1579                         (unsigned long)dx_get_block(frame->at),
1580                                         hash2, split, count-split));
1581
1582         /* Fancy dance to stay within two buffers */
1583         de2 = dx_move_dirents(data1, data2, map + split, count - split, blocksize);
1584         de = dx_pack_dirents(data1, blocksize);
1585         de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
1586                                            (char *) de,
1587                                            blocksize);
1588         de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
1589                                             (char *) de2,
1590                                             blocksize);
1591         if (csum_size) {
1592                 t = EXT4_DIRENT_TAIL(data2, blocksize);
1593                 initialize_dirent_tail(t, blocksize);
1594
1595                 t = EXT4_DIRENT_TAIL(data1, blocksize);
1596                 initialize_dirent_tail(t, blocksize);
1597         }
1598
1599         dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data1, blocksize, 1));
1600         dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data2, blocksize, 1));
1601
1602         /* Which block gets the new entry? */
1603         if (hinfo->hash >= hash2)
1604         {
1605                 swap(*bh, bh2);
1606                 de = de2;
1607         }
1608         dx_insert_block(frame, hash2 + continued, newblock);
1609         err = ext4_handle_dirty_dirent_node(handle, dir, bh2);
1610         if (err)
1611                 goto journal_error;
1612         err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
1613         if (err)
1614                 goto journal_error;
1615         brelse(bh2);
1616         dxtrace(dx_show_index("frame", frame->entries));
1617         return de;
1618
1619 journal_error:
1620         brelse(*bh);
1621         brelse(bh2);
1622         *bh = NULL;
1623         ext4_std_error(dir->i_sb, err);
1624 errout:
1625         *error = err;
1626         return NULL;
1627 }
1628
1629 int ext4_find_dest_de(struct inode *dir, struct inode *inode,
1630                       struct buffer_head *bh,
1631                       void *buf, int buf_size,
1632                       const char *name, int namelen,
1633                       struct ext4_dir_entry_2 **dest_de)
1634 {
1635         struct ext4_dir_entry_2 *de;
1636         unsigned short reclen = EXT4_DIR_REC_LEN(namelen);
1637         int nlen, rlen;
1638         unsigned int offset = 0;
1639         char *top;
1640
1641         de = (struct ext4_dir_entry_2 *)buf;
1642         top = buf + buf_size - reclen;
1643         while ((char *) de <= top) {
1644                 if (ext4_check_dir_entry(dir, NULL, de, bh,
1645                                          buf, buf_size, offset))
1646                         return -EIO;
1647                 if (ext4_match(namelen, name, de))
1648                         return -EEXIST;
1649                 nlen = EXT4_DIR_REC_LEN(de->name_len);
1650                 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
1651                 if ((de->inode ? rlen - nlen : rlen) >= reclen)
1652                         break;
1653                 de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
1654                 offset += rlen;
1655         }
1656         if ((char *) de > top)
1657                 return -ENOSPC;
1658
1659         *dest_de = de;
1660         return 0;
1661 }
1662
1663 void ext4_insert_dentry(struct inode *inode,
1664                         struct ext4_dir_entry_2 *de,
1665                         int buf_size,
1666                         const char *name, int namelen)
1667 {
1668
1669         int nlen, rlen;
1670
1671         nlen = EXT4_DIR_REC_LEN(de->name_len);
1672         rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
1673         if (de->inode) {
1674                 struct ext4_dir_entry_2 *de1 =
1675                                 (struct ext4_dir_entry_2 *)((char *)de + nlen);
1676                 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, buf_size);
1677                 de->rec_len = ext4_rec_len_to_disk(nlen, buf_size);
1678                 de = de1;
1679         }
1680         de->file_type = EXT4_FT_UNKNOWN;
1681         de->inode = cpu_to_le32(inode->i_ino);
1682         ext4_set_de_type(inode->i_sb, de, inode->i_mode);
1683         de->name_len = namelen;
1684         memcpy(de->name, name, namelen);
1685 }
1686 /*
1687  * Add a new entry into a directory (leaf) block.  If de is non-NULL,
1688  * it points to a directory entry which is guaranteed to be large
1689  * enough for new directory entry.  If de is NULL, then
1690  * add_dirent_to_buf will attempt search the directory block for
1691  * space.  It will return -ENOSPC if no space is available, and -EIO
1692  * and -EEXIST if directory entry already exists.
1693  */
1694 static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
1695                              struct inode *inode, struct ext4_dir_entry_2 *de,
1696                              struct buffer_head *bh)
1697 {
1698         struct inode    *dir = dentry->d_parent->d_inode;
1699         const char      *name = dentry->d_name.name;
1700         int             namelen = dentry->d_name.len;
1701         unsigned int    blocksize = dir->i_sb->s_blocksize;
1702         unsigned short  reclen;
1703         int             csum_size = 0;
1704         int             err;
1705
1706         if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
1707                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
1708                 csum_size = sizeof(struct ext4_dir_entry_tail);
1709
1710         reclen = EXT4_DIR_REC_LEN(namelen);
1711         if (!de) {
1712                 err = ext4_find_dest_de(dir, inode,
1713                                         bh, bh->b_data, blocksize - csum_size,
1714                                         name, namelen, &de);
1715                 if (err)
1716                         return err;
1717         }
1718         BUFFER_TRACE(bh, "get_write_access");
1719         err = ext4_journal_get_write_access(handle, bh);
1720         if (err) {
1721                 ext4_std_error(dir->i_sb, err);
1722                 return err;
1723         }
1724
1725         /* By now the buffer is marked for journaling */
1726         ext4_insert_dentry(inode, de, blocksize, name, namelen);
1727
1728         /*
1729          * XXX shouldn't update any times until successful
1730          * completion of syscall, but too many callers depend
1731          * on this.
1732          *
1733          * XXX similarly, too many callers depend on
1734          * ext4_new_inode() setting the times, but error
1735          * recovery deletes the inode, so the worst that can
1736          * happen is that the times are slightly out of date
1737          * and/or different from the directory change time.
1738          */
1739         dir->i_mtime = dir->i_ctime = ext4_current_time(dir);
1740         ext4_update_dx_flag(dir);
1741         dir->i_version++;
1742         ext4_mark_inode_dirty(handle, dir);
1743         BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1744         err = ext4_handle_dirty_dirent_node(handle, dir, bh);
1745         if (err)
1746                 ext4_std_error(dir->i_sb, err);
1747         return 0;
1748 }
1749
1750 /*
1751  * This converts a one block unindexed directory to a 3 block indexed
1752  * directory, and adds the dentry to the indexed directory.
1753  */
1754 static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
1755                             struct inode *inode, struct buffer_head *bh)
1756 {
1757         struct inode    *dir = dentry->d_parent->d_inode;
1758         const char      *name = dentry->d_name.name;
1759         int             namelen = dentry->d_name.len;
1760         struct buffer_head *bh2;
1761         struct dx_root  *root;
1762         struct dx_frame frames[2], *frame;
1763         struct dx_entry *entries;
1764         struct ext4_dir_entry_2 *de, *de2;
1765         struct ext4_dir_entry_tail *t;
1766         char            *data1, *top;
1767         unsigned        len;
1768         int             retval;
1769         unsigned        blocksize;
1770         struct dx_hash_info hinfo;
1771         ext4_lblk_t  block;
1772         struct fake_dirent *fde;
1773         int             csum_size = 0;
1774
1775         if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
1776                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
1777                 csum_size = sizeof(struct ext4_dir_entry_tail);
1778
1779         blocksize =  dir->i_sb->s_blocksize;
1780         dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
1781         retval = ext4_journal_get_write_access(handle, bh);
1782         if (retval) {
1783                 ext4_std_error(dir->i_sb, retval);
1784                 brelse(bh);
1785                 return retval;
1786         }
1787         root = (struct dx_root *) bh->b_data;
1788
1789         /* The 0th block becomes the root, move the dirents out */
1790         fde = &root->dotdot;
1791         de = (struct ext4_dir_entry_2 *)((char *)fde +
1792                 ext4_rec_len_from_disk(fde->rec_len, blocksize));
1793         if ((char *) de >= (((char *) root) + blocksize)) {
1794                 EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
1795                 brelse(bh);
1796                 return -EIO;
1797         }
1798         len = ((char *) root) + (blocksize - csum_size) - (char *) de;
1799
1800         /* Allocate new block for the 0th block's dirents */
1801         bh2 = ext4_append(handle, dir, &block, &retval);
1802         if (!(bh2)) {
1803                 brelse(bh);
1804                 return retval;
1805         }
1806         ext4_set_inode_flag(dir, EXT4_INODE_INDEX);
1807         data1 = bh2->b_data;
1808
1809         memcpy (data1, de, len);
1810         de = (struct ext4_dir_entry_2 *) data1;
1811         top = data1 + len;
1812         while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
1813                 de = de2;
1814         de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
1815                                            (char *) de,
1816                                            blocksize);
1817
1818         if (csum_size) {
1819                 t = EXT4_DIRENT_TAIL(data1, blocksize);
1820                 initialize_dirent_tail(t, blocksize);
1821         }
1822
1823         /* Initialize the root; the dot dirents already exist */
1824         de = (struct ext4_dir_entry_2 *) (&root->dotdot);
1825         de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
1826                                            blocksize);
1827         memset (&root->info, 0, sizeof(root->info));
1828         root->info.info_length = sizeof(root->info);
1829         root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
1830         entries = root->entries;
1831         dx_set_block(entries, 1);
1832         dx_set_count(entries, 1);
1833         dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
1834
1835         /* Initialize as for dx_probe */
1836         hinfo.hash_version = root->info.hash_version;
1837         if (hinfo.hash_version <= DX_HASH_TEA)
1838                 hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
1839         hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
1840         ext4fs_dirhash(name, namelen, &hinfo);
1841         frame = frames;
1842         frame->entries = entries;
1843         frame->at = entries;
1844         frame->bh = bh;
1845         bh = bh2;
1846
1847         ext4_handle_dirty_dx_node(handle, dir, frame->bh);
1848         ext4_handle_dirty_dirent_node(handle, dir, bh);
1849
1850         de = do_split(handle,dir, &bh, frame, &hinfo, &retval);
1851         if (!de) {
1852                 /*
1853                  * Even if the block split failed, we have to properly write
1854                  * out all the changes we did so far. Otherwise we can end up
1855                  * with corrupted filesystem.
1856                  */
1857                 ext4_mark_inode_dirty(handle, dir);
1858                 dx_release(frames);
1859                 return retval;
1860         }
1861         dx_release(frames);
1862
1863         retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
1864         brelse(bh);
1865         return retval;
1866 }
1867
1868 /*
1869  *      ext4_add_entry()
1870  *
1871  * adds a file entry to the specified directory, using the same
1872  * semantics as ext4_find_entry(). It returns NULL if it failed.
1873  *
1874  * NOTE!! The inode part of 'de' is left at 0 - which means you
1875  * may not sleep between calling this and putting something into
1876  * the entry, as someone else might have used it while you slept.
1877  */
1878 static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
1879                           struct inode *inode)
1880 {
1881         struct inode *dir = dentry->d_parent->d_inode;
1882         struct buffer_head *bh;
1883         struct ext4_dir_entry_2 *de;
1884         struct ext4_dir_entry_tail *t;
1885         struct super_block *sb;
1886         int     retval;
1887         int     dx_fallback=0;
1888         unsigned blocksize;
1889         ext4_lblk_t block, blocks;
1890         int     csum_size = 0;
1891
1892         if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
1893                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
1894                 csum_size = sizeof(struct ext4_dir_entry_tail);
1895
1896         sb = dir->i_sb;
1897         blocksize = sb->s_blocksize;
1898         if (!dentry->d_name.len)
1899                 return -EINVAL;
1900
1901         if (ext4_has_inline_data(dir)) {
1902                 retval = ext4_try_add_inline_entry(handle, dentry, inode);
1903                 if (retval < 0)
1904                         return retval;
1905                 if (retval == 1) {
1906                         retval = 0;
1907                         return retval;
1908                 }
1909         }
1910
1911         if (is_dx(dir)) {
1912                 retval = ext4_dx_add_entry(handle, dentry, inode);
1913                 if (!retval || (retval != ERR_BAD_DX_DIR))
1914                         return retval;
1915                 ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
1916                 dx_fallback++;
1917                 ext4_mark_inode_dirty(handle, dir);
1918         }
1919         blocks = dir->i_size >> sb->s_blocksize_bits;
1920         for (block = 0; block < blocks; block++) {
1921                 if (!(bh = ext4_bread(handle, dir, block, 0, &retval))) {
1922                         if (!retval) {
1923                                 retval = -EIO;
1924                                 ext4_error(inode->i_sb,
1925                                            "Directory hole detected on inode %lu\n",
1926                                            inode->i_ino);
1927                         }
1928                         return retval;
1929                 }
1930                 if (!buffer_verified(bh) &&
1931                     !ext4_dirent_csum_verify(dir,
1932                                 (struct ext4_dir_entry *)bh->b_data))
1933                         return -EIO;
1934                 set_buffer_verified(bh);
1935                 retval = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
1936                 if (retval != -ENOSPC) {
1937                         brelse(bh);
1938                         return retval;
1939                 }
1940
1941                 if (blocks == 1 && !dx_fallback &&
1942                     EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX))
1943                         return make_indexed_dir(handle, dentry, inode, bh);
1944                 brelse(bh);
1945         }
1946         bh = ext4_append(handle, dir, &block, &retval);
1947         if (!bh)
1948                 return retval;
1949         de = (struct ext4_dir_entry_2 *) bh->b_data;
1950         de->inode = 0;
1951         de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize);
1952
1953         if (csum_size) {
1954                 t = EXT4_DIRENT_TAIL(bh->b_data, blocksize);
1955                 initialize_dirent_tail(t, blocksize);
1956         }
1957
1958         retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
1959         brelse(bh);
1960         if (retval == 0)
1961                 ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY);
1962         return retval;
1963 }
1964
1965 /*
1966  * Returns 0 for success, or a negative error value
1967  */
1968 static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
1969                              struct inode *inode)
1970 {
1971         struct dx_frame frames[2], *frame;
1972         struct dx_entry *entries, *at;
1973         struct dx_hash_info hinfo;
1974         struct buffer_head *bh;
1975         struct inode *dir = dentry->d_parent->d_inode;
1976         struct super_block *sb = dir->i_sb;
1977         struct ext4_dir_entry_2 *de;
1978         int err;
1979
1980         frame = dx_probe(&dentry->d_name, dir, &hinfo, frames, &err);
1981         if (!frame)
1982                 return err;
1983         entries = frame->entries;
1984         at = frame->at;
1985
1986         if (!(bh = ext4_bread(handle, dir, dx_get_block(frame->at), 0, &err))) {
1987                 if (!err) {
1988                         err = -EIO;
1989                         ext4_error(dir->i_sb,
1990                                    "Directory hole detected on inode %lu\n",
1991                                    dir->i_ino);
1992                 }
1993                 goto cleanup;
1994         }
1995
1996         if (!buffer_verified(bh) &&
1997             !ext4_dirent_csum_verify(dir, (struct ext4_dir_entry *)bh->b_data))
1998                 goto journal_error;
1999         set_buffer_verified(bh);
2000
2001         BUFFER_TRACE(bh, "get_write_access");
2002         err = ext4_journal_get_write_access(handle, bh);
2003         if (err)
2004                 goto journal_error;
2005
2006         err = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
2007         if (err != -ENOSPC)
2008                 goto cleanup;
2009
2010         /* Block full, should compress but for now just split */
2011         dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
2012                        dx_get_count(entries), dx_get_limit(entries)));
2013         /* Need to split index? */
2014         if (dx_get_count(entries) == dx_get_limit(entries)) {
2015                 ext4_lblk_t newblock;
2016                 unsigned icount = dx_get_count(entries);
2017                 int levels = frame - frames;
2018                 struct dx_entry *entries2;
2019                 struct dx_node *node2;
2020                 struct buffer_head *bh2;
2021
2022                 if (levels && (dx_get_count(frames->entries) ==
2023                                dx_get_limit(frames->entries))) {
2024                         ext4_warning(sb, "Directory index full!");
2025                         err = -ENOSPC;
2026                         goto cleanup;
2027                 }
2028                 bh2 = ext4_append (handle, dir, &newblock, &err);
2029                 if (!(bh2))
2030                         goto cleanup;
2031                 node2 = (struct dx_node *)(bh2->b_data);
2032                 entries2 = node2->entries;
2033                 memset(&node2->fake, 0, sizeof(struct fake_dirent));
2034                 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
2035                                                            sb->s_blocksize);
2036                 BUFFER_TRACE(frame->bh, "get_write_access");
2037                 err = ext4_journal_get_write_access(handle, frame->bh);
2038                 if (err)
2039                         goto journal_error;
2040                 if (levels) {
2041                         unsigned icount1 = icount/2, icount2 = icount - icount1;
2042                         unsigned hash2 = dx_get_hash(entries + icount1);
2043                         dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
2044                                        icount1, icount2));
2045
2046                         BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
2047                         err = ext4_journal_get_write_access(handle,
2048                                                              frames[0].bh);
2049                         if (err)
2050                                 goto journal_error;
2051
2052                         memcpy((char *) entries2, (char *) (entries + icount1),
2053                                icount2 * sizeof(struct dx_entry));
2054                         dx_set_count(entries, icount1);
2055                         dx_set_count(entries2, icount2);
2056                         dx_set_limit(entries2, dx_node_limit(dir));
2057
2058                         /* Which index block gets the new entry? */
2059                         if (at - entries >= icount1) {
2060                                 frame->at = at = at - entries - icount1 + entries2;
2061                                 frame->entries = entries = entries2;
2062                                 swap(frame->bh, bh2);
2063                         }
2064                         dx_insert_block(frames + 0, hash2, newblock);
2065                         dxtrace(dx_show_index("node", frames[1].entries));
2066                         dxtrace(dx_show_index("node",
2067                                ((struct dx_node *) bh2->b_data)->entries));
2068                         err = ext4_handle_dirty_dx_node(handle, dir, bh2);
2069                         if (err)
2070                                 goto journal_error;
2071                         brelse (bh2);
2072                 } else {
2073                         dxtrace(printk(KERN_DEBUG
2074                                        "Creating second level index...\n"));
2075                         memcpy((char *) entries2, (char *) entries,
2076                                icount * sizeof(struct dx_entry));
2077                         dx_set_limit(entries2, dx_node_limit(dir));
2078
2079                         /* Set up root */
2080                         dx_set_count(entries, 1);
2081                         dx_set_block(entries + 0, newblock);
2082                         ((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels = 1;
2083
2084                         /* Add new access path frame */
2085                         frame = frames + 1;
2086                         frame->at = at = at - entries + entries2;
2087                         frame->entries = entries = entries2;
2088                         frame->bh = bh2;
2089                         err = ext4_journal_get_write_access(handle,
2090                                                              frame->bh);
2091                         if (err)
2092                                 goto journal_error;
2093                 }
2094                 err = ext4_handle_dirty_dx_node(handle, dir, frames[0].bh);
2095                 if (err) {
2096                         ext4_std_error(inode->i_sb, err);
2097                         goto cleanup;
2098                 }
2099         }
2100         de = do_split(handle, dir, &bh, frame, &hinfo, &err);
2101         if (!de)
2102                 goto cleanup;
2103         err = add_dirent_to_buf(handle, dentry, inode, de, bh);
2104         goto cleanup;
2105
2106 journal_error:
2107         ext4_std_error(dir->i_sb, err);
2108 cleanup:
2109         if (bh)
2110                 brelse(bh);
2111         dx_release(frames);
2112         return err;
2113 }
2114
2115 /*
2116  * ext4_generic_delete_entry deletes a directory entry by merging it
2117  * with the previous entry
2118  */
2119 int ext4_generic_delete_entry(handle_t *handle,
2120                               struct inode *dir,
2121                               struct ext4_dir_entry_2 *de_del,
2122                               struct buffer_head *bh,
2123                               void *entry_buf,
2124                               int buf_size,
2125                               int csum_size)
2126 {
2127         struct ext4_dir_entry_2 *de, *pde;
2128         unsigned int blocksize = dir->i_sb->s_blocksize;
2129         int i;
2130
2131         i = 0;
2132         pde = NULL;
2133         de = (struct ext4_dir_entry_2 *)entry_buf;
2134         while (i < buf_size - csum_size) {
2135                 if (ext4_check_dir_entry(dir, NULL, de, bh,
2136                                          bh->b_data, bh->b_size, i))
2137                         return -EIO;
2138                 if (de == de_del)  {
2139                         if (pde)
2140                                 pde->rec_len = ext4_rec_len_to_disk(
2141                                         ext4_rec_len_from_disk(pde->rec_len,
2142                                                                blocksize) +
2143                                         ext4_rec_len_from_disk(de->rec_len,
2144                                                                blocksize),
2145                                         blocksize);
2146                         else
2147                                 de->inode = 0;
2148                         dir->i_version++;
2149                         return 0;
2150                 }
2151                 i += ext4_rec_len_from_disk(de->rec_len, blocksize);
2152                 pde = de;
2153                 de = ext4_next_entry(de, blocksize);
2154         }
2155         return -ENOENT;
2156 }
2157
2158 static int ext4_delete_entry(handle_t *handle,
2159                              struct inode *dir,
2160                              struct ext4_dir_entry_2 *de_del,
2161                              struct buffer_head *bh)
2162 {
2163         int err, csum_size = 0;
2164
2165         if (ext4_has_inline_data(dir)) {
2166                 int has_inline_data = 1;
2167                 err = ext4_delete_inline_entry(handle, dir, de_del, bh,
2168                                                &has_inline_data);
2169                 if (has_inline_data)
2170                         return err;
2171         }
2172
2173         if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
2174                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
2175                 csum_size = sizeof(struct ext4_dir_entry_tail);
2176
2177         BUFFER_TRACE(bh, "get_write_access");
2178         err = ext4_journal_get_write_access(handle, bh);
2179         if (unlikely(err))
2180                 goto out;
2181
2182         err = ext4_generic_delete_entry(handle, dir, de_del,
2183                                         bh, bh->b_data,
2184                                         dir->i_sb->s_blocksize, csum_size);
2185         if (err)
2186                 goto out;
2187
2188         BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
2189         err = ext4_handle_dirty_dirent_node(handle, dir, bh);
2190         if (unlikely(err))
2191                 goto out;
2192
2193         return 0;
2194 out:
2195         if (err != -ENOENT)
2196                 ext4_std_error(dir->i_sb, err);
2197         return err;
2198 }
2199
2200 /*
2201  * DIR_NLINK feature is set if 1) nlinks > EXT4_LINK_MAX or 2) nlinks == 2,
2202  * since this indicates that nlinks count was previously 1.
2203  */
2204 static void ext4_inc_count(handle_t *handle, struct inode *inode)
2205 {
2206         inc_nlink(inode);
2207         if (is_dx(inode) && inode->i_nlink > 1) {
2208                 /* limit is 16-bit i_links_count */
2209                 if (inode->i_nlink >= EXT4_LINK_MAX || inode->i_nlink == 2) {
2210                         set_nlink(inode, 1);
2211                         EXT4_SET_RO_COMPAT_FEATURE(inode->i_sb,
2212                                               EXT4_FEATURE_RO_COMPAT_DIR_NLINK);
2213                 }
2214         }
2215 }
2216
2217 /*
2218  * If a directory had nlink == 1, then we should let it be 1. This indicates
2219  * directory has >EXT4_LINK_MAX subdirs.
2220  */
2221 static void ext4_dec_count(handle_t *handle, struct inode *inode)
2222 {
2223         if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
2224                 drop_nlink(inode);
2225 }
2226
2227
2228 static int ext4_add_nondir(handle_t *handle,
2229                 struct dentry *dentry, struct inode *inode)
2230 {
2231         int err = ext4_add_entry(handle, dentry, inode);
2232         if (!err) {
2233                 ext4_mark_inode_dirty(handle, inode);
2234                 unlock_new_inode(inode);
2235                 d_instantiate(dentry, inode);
2236                 return 0;
2237         }
2238         drop_nlink(inode);
2239         unlock_new_inode(inode);
2240         iput(inode);
2241         return err;
2242 }
2243
2244 /*
2245  * By the time this is called, we already have created
2246  * the directory cache entry for the new file, but it
2247  * is so far negative - it has no inode.
2248  *
2249  * If the create succeeds, we fill in the inode information
2250  * with d_instantiate().
2251  */
2252 static int ext4_create(struct inode *dir, struct dentry *dentry, umode_t mode,
2253                        bool excl)
2254 {
2255         handle_t *handle;
2256         struct inode *inode;
2257         int err, retries = 0;
2258
2259         dquot_initialize(dir);
2260
2261 retry:
2262         handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2263                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
2264                                         EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
2265         if (IS_ERR(handle))
2266                 return PTR_ERR(handle);
2267
2268         if (IS_DIRSYNC(dir))
2269                 ext4_handle_sync(handle);
2270
2271         inode = ext4_new_inode(handle, dir, mode, &dentry->d_name, 0, NULL);
2272         err = PTR_ERR(inode);
2273         if (!IS_ERR(inode)) {
2274                 inode->i_op = &ext4_file_inode_operations;
2275                 inode->i_fop = &ext4_file_operations;
2276                 ext4_set_aops(inode);
2277                 err = ext4_add_nondir(handle, dentry, inode);
2278         }
2279         ext4_journal_stop(handle);
2280         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2281                 goto retry;
2282         return err;
2283 }
2284
2285 static int ext4_mknod(struct inode *dir, struct dentry *dentry,
2286                       umode_t mode, dev_t rdev)
2287 {
2288         handle_t *handle;
2289         struct inode *inode;
2290         int err, retries = 0;
2291
2292         if (!new_valid_dev(rdev))
2293                 return -EINVAL;
2294
2295         dquot_initialize(dir);
2296
2297 retry:
2298         handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2299                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
2300                                         EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
2301         if (IS_ERR(handle))
2302                 return PTR_ERR(handle);
2303
2304         if (IS_DIRSYNC(dir))
2305                 ext4_handle_sync(handle);
2306
2307         inode = ext4_new_inode(handle, dir, mode, &dentry->d_name, 0, NULL);
2308         err = PTR_ERR(inode);
2309         if (!IS_ERR(inode)) {
2310                 init_special_inode(inode, inode->i_mode, rdev);
2311                 inode->i_op = &ext4_special_inode_operations;
2312                 err = ext4_add_nondir(handle, dentry, inode);
2313         }
2314         ext4_journal_stop(handle);
2315         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2316                 goto retry;
2317         return err;
2318 }
2319
2320 struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
2321                           struct ext4_dir_entry_2 *de,
2322                           int blocksize, int csum_size,
2323                           unsigned int parent_ino, int dotdot_real_len)
2324 {
2325         de->inode = cpu_to_le32(inode->i_ino);
2326         de->name_len = 1;
2327         de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
2328                                            blocksize);
2329         strcpy(de->name, ".");
2330         ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2331
2332         de = ext4_next_entry(de, blocksize);
2333         de->inode = cpu_to_le32(parent_ino);
2334         de->name_len = 2;
2335         if (!dotdot_real_len)
2336                 de->rec_len = ext4_rec_len_to_disk(blocksize -
2337                                         (csum_size + EXT4_DIR_REC_LEN(1)),
2338                                         blocksize);
2339         else
2340                 de->rec_len = ext4_rec_len_to_disk(
2341                                 EXT4_DIR_REC_LEN(de->name_len), blocksize);
2342         strcpy(de->name, "..");
2343         ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2344
2345         return ext4_next_entry(de, blocksize);
2346 }
2347
2348 static int ext4_init_new_dir(handle_t *handle, struct inode *dir,
2349                              struct inode *inode)
2350 {
2351         struct buffer_head *dir_block = NULL;
2352         struct ext4_dir_entry_2 *de;
2353         struct ext4_dir_entry_tail *t;
2354         unsigned int blocksize = dir->i_sb->s_blocksize;
2355         int csum_size = 0;
2356         int err;
2357
2358         if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
2359                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
2360                 csum_size = sizeof(struct ext4_dir_entry_tail);
2361
2362         if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
2363                 err = ext4_try_create_inline_dir(handle, dir, inode);
2364                 if (err < 0 && err != -ENOSPC)
2365                         goto out;
2366                 if (!err)
2367                         goto out;
2368         }
2369
2370         inode->i_size = EXT4_I(inode)->i_disksize = blocksize;
2371         if (!(dir_block = ext4_bread(handle, inode, 0, 1, &err))) {
2372                 if (!err) {
2373                         err = -EIO;
2374                         ext4_error(inode->i_sb,
2375                                    "Directory hole detected on inode %lu\n",
2376                                    inode->i_ino);
2377                 }
2378                 goto out;
2379         }
2380         BUFFER_TRACE(dir_block, "get_write_access");
2381         err = ext4_journal_get_write_access(handle, dir_block);
2382         if (err)
2383                 goto out;
2384         de = (struct ext4_dir_entry_2 *)dir_block->b_data;
2385         ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0);
2386         set_nlink(inode, 2);
2387         if (csum_size) {
2388                 t = EXT4_DIRENT_TAIL(dir_block->b_data, blocksize);
2389                 initialize_dirent_tail(t, blocksize);
2390         }
2391
2392         BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
2393         err = ext4_handle_dirty_dirent_node(handle, inode, dir_block);
2394         if (err)
2395                 goto out;
2396         set_buffer_verified(dir_block);
2397 out:
2398         brelse(dir_block);
2399         return err;
2400 }
2401
2402 static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
2403 {
2404         handle_t *handle;
2405         struct inode *inode;
2406         int err, retries = 0;
2407
2408         if (EXT4_DIR_LINK_MAX(dir))
2409                 return -EMLINK;
2410
2411         dquot_initialize(dir);
2412
2413 retry:
2414         handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2415                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
2416                                         EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
2417         if (IS_ERR(handle))
2418                 return PTR_ERR(handle);
2419
2420         if (IS_DIRSYNC(dir))
2421                 ext4_handle_sync(handle);
2422
2423         inode = ext4_new_inode(handle, dir, S_IFDIR | mode,
2424                                &dentry->d_name, 0, NULL);
2425         err = PTR_ERR(inode);
2426         if (IS_ERR(inode))
2427                 goto out_stop;
2428
2429         inode->i_op = &ext4_dir_inode_operations;
2430         inode->i_fop = &ext4_dir_operations;
2431         err = ext4_init_new_dir(handle, dir, inode);
2432         if (err)
2433                 goto out_clear_inode;
2434         err = ext4_mark_inode_dirty(handle, inode);
2435         if (!err)
2436                 err = ext4_add_entry(handle, dentry, inode);
2437         if (err) {
2438 out_clear_inode:
2439                 clear_nlink(inode);
2440                 unlock_new_inode(inode);
2441                 ext4_mark_inode_dirty(handle, inode);
2442                 iput(inode);
2443                 goto out_stop;
2444         }
2445         ext4_inc_count(handle, dir);
2446         ext4_update_dx_flag(dir);
2447         err = ext4_mark_inode_dirty(handle, dir);
2448         if (err)
2449                 goto out_clear_inode;
2450         unlock_new_inode(inode);
2451         d_instantiate(dentry, inode);
2452 out_stop:
2453         ext4_journal_stop(handle);
2454         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2455                 goto retry;
2456         return err;
2457 }
2458
2459 /*
2460  * routine to check that the specified directory is empty (for rmdir)
2461  */
2462 static int empty_dir(struct inode *inode)
2463 {
2464         unsigned int offset;
2465         struct buffer_head *bh;
2466         struct ext4_dir_entry_2 *de, *de1;
2467         struct super_block *sb;
2468         int err = 0;
2469
2470         if (ext4_has_inline_data(inode)) {
2471                 int has_inline_data = 1;
2472
2473                 err = empty_inline_dir(inode, &has_inline_data);
2474                 if (has_inline_data)
2475                         return err;
2476         }
2477
2478         sb = inode->i_sb;
2479         if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2) ||
2480             !(bh = ext4_bread(NULL, inode, 0, 0, &err))) {
2481                 if (err)
2482                         EXT4_ERROR_INODE(inode,
2483                                 "error %d reading directory lblock 0", err);
2484                 else
2485                         ext4_warning(inode->i_sb,
2486                                      "bad directory (dir #%lu) - no data block",
2487                                      inode->i_ino);
2488                 return 1;
2489         }
2490         if (!buffer_verified(bh) &&
2491             !ext4_dirent_csum_verify(inode,
2492                         (struct ext4_dir_entry *)bh->b_data)) {
2493                 EXT4_ERROR_INODE(inode, "checksum error reading directory "
2494                                  "lblock 0");
2495                 return -EIO;
2496         }
2497         set_buffer_verified(bh);
2498         de = (struct ext4_dir_entry_2 *) bh->b_data;
2499         de1 = ext4_next_entry(de, sb->s_blocksize);
2500         if (le32_to_cpu(de->inode) != inode->i_ino ||
2501                         !le32_to_cpu(de1->inode) ||
2502                         strcmp(".", de->name) ||
2503                         strcmp("..", de1->name)) {
2504                 ext4_warning(inode->i_sb,
2505                              "bad directory (dir #%lu) - no `.' or `..'",
2506                              inode->i_ino);
2507                 brelse(bh);
2508                 return 1;
2509         }
2510         offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) +
2511                  ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize);
2512         de = ext4_next_entry(de1, sb->s_blocksize);
2513         while (offset < inode->i_size) {
2514                 if (!bh ||
2515                     (void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
2516                         unsigned int lblock;
2517                         err = 0;
2518                         brelse(bh);
2519                         lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb);
2520                         bh = ext4_bread(NULL, inode, lblock, 0, &err);
2521                         if (!bh) {
2522                                 if (err)
2523                                         EXT4_ERROR_INODE(inode,
2524                                                 "error %d reading directory "
2525                                                 "lblock %u", err, lblock);
2526                                 else
2527                                         ext4_warning(inode->i_sb,
2528                                                 "bad directory (dir #%lu) - no data block",
2529                                                 inode->i_ino);
2530
2531                                 offset += sb->s_blocksize;
2532                                 continue;
2533                         }
2534                         if (!buffer_verified(bh) &&
2535                             !ext4_dirent_csum_verify(inode,
2536                                         (struct ext4_dir_entry *)bh->b_data)) {
2537                                 EXT4_ERROR_INODE(inode, "checksum error "
2538                                                  "reading directory lblock 0");
2539                                 return -EIO;
2540                         }
2541                         set_buffer_verified(bh);
2542                         de = (struct ext4_dir_entry_2 *) bh->b_data;
2543                 }
2544                 if (ext4_check_dir_entry(inode, NULL, de, bh,
2545                                          bh->b_data, bh->b_size, offset)) {
2546                         de = (struct ext4_dir_entry_2 *)(bh->b_data +
2547                                                          sb->s_blocksize);
2548                         offset = (offset | (sb->s_blocksize - 1)) + 1;
2549                         continue;
2550                 }
2551                 if (le32_to_cpu(de->inode)) {
2552                         brelse(bh);
2553                         return 0;
2554                 }
2555                 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
2556                 de = ext4_next_entry(de, sb->s_blocksize);
2557         }
2558         brelse(bh);
2559         return 1;
2560 }
2561
2562 /* ext4_orphan_add() links an unlinked or truncated inode into a list of
2563  * such inodes, starting at the superblock, in case we crash before the
2564  * file is closed/deleted, or in case the inode truncate spans multiple
2565  * transactions and the last transaction is not recovered after a crash.
2566  *
2567  * At filesystem recovery time, we walk this list deleting unlinked
2568  * inodes and truncating linked inodes in ext4_orphan_cleanup().
2569  */
2570 int ext4_orphan_add(handle_t *handle, struct inode *inode)
2571 {
2572         struct super_block *sb = inode->i_sb;
2573         struct ext4_iloc iloc;
2574         int err = 0, rc;
2575
2576         if (!EXT4_SB(sb)->s_journal)
2577                 return 0;
2578
2579         mutex_lock(&EXT4_SB(sb)->s_orphan_lock);
2580         if (!list_empty(&EXT4_I(inode)->i_orphan))
2581                 goto out_unlock;
2582
2583         /*
2584          * Orphan handling is only valid for files with data blocks
2585          * being truncated, or files being unlinked. Note that we either
2586          * hold i_mutex, or the inode can not be referenced from outside,
2587          * so i_nlink should not be bumped due to race
2588          */
2589         J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2590                   S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
2591
2592         BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access");
2593         err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
2594         if (err)
2595                 goto out_unlock;
2596
2597         err = ext4_reserve_inode_write(handle, inode, &iloc);
2598         if (err)
2599                 goto out_unlock;
2600         /*
2601          * Due to previous errors inode may be already a part of on-disk
2602          * orphan list. If so skip on-disk list modification.
2603          */
2604         if (NEXT_ORPHAN(inode) && NEXT_ORPHAN(inode) <=
2605                 (le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count)))
2606                         goto mem_insert;
2607
2608         /* Insert this inode at the head of the on-disk orphan list... */
2609         NEXT_ORPHAN(inode) = le32_to_cpu(EXT4_SB(sb)->s_es->s_last_orphan);
2610         EXT4_SB(sb)->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
2611         err = ext4_handle_dirty_super(handle, sb);
2612         rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
2613         if (!err)
2614                 err = rc;
2615
2616         /* Only add to the head of the in-memory list if all the
2617          * previous operations succeeded.  If the orphan_add is going to
2618          * fail (possibly taking the journal offline), we can't risk
2619          * leaving the inode on the orphan list: stray orphan-list
2620          * entries can cause panics at unmount time.
2621          *
2622          * This is safe: on error we're going to ignore the orphan list
2623          * anyway on the next recovery. */
2624 mem_insert:
2625         if (!err)
2626                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2627
2628         jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
2629         jbd_debug(4, "orphan inode %lu will point to %d\n",
2630                         inode->i_ino, NEXT_ORPHAN(inode));
2631 out_unlock:
2632         mutex_unlock(&EXT4_SB(sb)->s_orphan_lock);
2633         ext4_std_error(inode->i_sb, err);
2634         return err;
2635 }
2636
2637 /*
2638  * ext4_orphan_del() removes an unlinked or truncated inode from the list
2639  * of such inodes stored on disk, because it is finally being cleaned up.
2640  */
2641 int ext4_orphan_del(handle_t *handle, struct inode *inode)
2642 {
2643         struct list_head *prev;
2644         struct ext4_inode_info *ei = EXT4_I(inode);
2645         struct ext4_sb_info *sbi;
2646         __u32 ino_next;
2647         struct ext4_iloc iloc;
2648         int err = 0;
2649
2650         if ((!EXT4_SB(inode->i_sb)->s_journal) &&
2651             !(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_ORPHAN_FS))
2652                 return 0;
2653
2654         mutex_lock(&EXT4_SB(inode->i_sb)->s_orphan_lock);
2655         if (list_empty(&ei->i_orphan))
2656                 goto out;
2657
2658         ino_next = NEXT_ORPHAN(inode);
2659         prev = ei->i_orphan.prev;
2660         sbi = EXT4_SB(inode->i_sb);
2661
2662         jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
2663
2664         list_del_init(&ei->i_orphan);
2665
2666         /* If we're on an error path, we may not have a valid
2667          * transaction handle with which to update the orphan list on
2668          * disk, but we still need to remove the inode from the linked
2669          * list in memory. */
2670         if (!handle)
2671                 goto out;
2672
2673         err = ext4_reserve_inode_write(handle, inode, &iloc);
2674         if (err)
2675                 goto out_err;
2676
2677         if (prev == &sbi->s_orphan) {
2678                 jbd_debug(4, "superblock will point to %u\n", ino_next);
2679                 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2680                 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2681                 if (err)
2682                         goto out_brelse;
2683                 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
2684                 err = ext4_handle_dirty_super(handle, inode->i_sb);
2685         } else {
2686                 struct ext4_iloc iloc2;
2687                 struct inode *i_prev =
2688                         &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
2689
2690                 jbd_debug(4, "orphan inode %lu will point to %u\n",
2691                           i_prev->i_ino, ino_next);
2692                 err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
2693                 if (err)
2694                         goto out_brelse;
2695                 NEXT_ORPHAN(i_prev) = ino_next;
2696                 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
2697         }
2698         if (err)
2699                 goto out_brelse;
2700         NEXT_ORPHAN(inode) = 0;
2701         err = ext4_mark_iloc_dirty(handle, inode, &iloc);
2702
2703 out_err:
2704         ext4_std_error(inode->i_sb, err);
2705 out:
2706         mutex_unlock(&EXT4_SB(inode->i_sb)->s_orphan_lock);
2707         return err;
2708
2709 out_brelse:
2710         brelse(iloc.bh);
2711         goto out_err;
2712 }
2713
2714 static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
2715 {
2716         int retval;
2717         struct inode *inode;
2718         struct buffer_head *bh;
2719         struct ext4_dir_entry_2 *de;
2720         handle_t *handle;
2721
2722         /* Initialize quotas before so that eventual writes go in
2723          * separate transaction */
2724         dquot_initialize(dir);
2725         dquot_initialize(dentry->d_inode);
2726
2727         handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb));
2728         if (IS_ERR(handle))
2729                 return PTR_ERR(handle);
2730
2731         retval = -ENOENT;
2732         bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
2733         if (!bh)
2734                 goto end_rmdir;
2735
2736         if (IS_DIRSYNC(dir))
2737                 ext4_handle_sync(handle);
2738
2739         inode = dentry->d_inode;
2740
2741         retval = -EIO;
2742         if (le32_to_cpu(de->inode) != inode->i_ino)
2743                 goto end_rmdir;
2744
2745         retval = -ENOTEMPTY;
2746         if (!empty_dir(inode))
2747                 goto end_rmdir;
2748
2749         retval = ext4_delete_entry(handle, dir, de, bh);
2750         if (retval)
2751                 goto end_rmdir;
2752         if (!EXT4_DIR_LINK_EMPTY(inode))
2753                 ext4_warning(inode->i_sb,
2754                              "empty directory has too many links (%d)",
2755                              inode->i_nlink);
2756         inode->i_version++;
2757         clear_nlink(inode);
2758         /* There's no need to set i_disksize: the fact that i_nlink is
2759          * zero will ensure that the right thing happens during any
2760          * recovery. */
2761         inode->i_size = 0;
2762         ext4_orphan_add(handle, inode);
2763         inode->i_ctime = dir->i_ctime = dir->i_mtime = ext4_current_time(inode);
2764         ext4_mark_inode_dirty(handle, inode);
2765         ext4_dec_count(handle, dir);
2766         ext4_update_dx_flag(dir);
2767         ext4_mark_inode_dirty(handle, dir);
2768
2769 end_rmdir:
2770         ext4_journal_stop(handle);
2771         brelse(bh);
2772         return retval;
2773 }
2774
2775 static int ext4_unlink(struct inode *dir, struct dentry *dentry)
2776 {
2777         int retval;
2778         struct inode *inode;
2779         struct buffer_head *bh;
2780         struct ext4_dir_entry_2 *de;
2781         handle_t *handle;
2782
2783         trace_ext4_unlink_enter(dir, dentry);
2784         /* Initialize quotas before so that eventual writes go
2785          * in separate transaction */
2786         dquot_initialize(dir);
2787         dquot_initialize(dentry->d_inode);
2788
2789         handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb));
2790         if (IS_ERR(handle))
2791                 return PTR_ERR(handle);
2792
2793         if (IS_DIRSYNC(dir))
2794                 ext4_handle_sync(handle);
2795
2796         retval = -ENOENT;
2797         bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
2798         if (!bh)
2799                 goto end_unlink;
2800
2801         inode = dentry->d_inode;
2802
2803         retval = -EIO;
2804         if (le32_to_cpu(de->inode) != inode->i_ino)
2805                 goto end_unlink;
2806
2807         if (!inode->i_nlink) {
2808                 ext4_warning(inode->i_sb,
2809                              "Deleting nonexistent file (%lu), %d",
2810                              inode->i_ino, inode->i_nlink);
2811                 set_nlink(inode, 1);
2812         }
2813         retval = ext4_delete_entry(handle, dir, de, bh);
2814         if (retval)
2815                 goto end_unlink;
2816         dir->i_ctime = dir->i_mtime = ext4_current_time(dir);
2817         ext4_update_dx_flag(dir);
2818         ext4_mark_inode_dirty(handle, dir);
2819         drop_nlink(inode);
2820         if (!inode->i_nlink)
2821                 ext4_orphan_add(handle, inode);
2822         inode->i_ctime = ext4_current_time(inode);
2823         ext4_mark_inode_dirty(handle, inode);
2824         retval = 0;
2825
2826 end_unlink:
2827         ext4_journal_stop(handle);
2828         brelse(bh);
2829         trace_ext4_unlink_exit(dentry, retval);
2830         return retval;
2831 }
2832
2833 static int ext4_symlink(struct inode *dir,
2834                         struct dentry *dentry, const char *symname)
2835 {
2836         handle_t *handle;
2837         struct inode *inode;
2838         int l, err, retries = 0;
2839         int credits;
2840
2841         l = strlen(symname)+1;
2842         if (l > dir->i_sb->s_blocksize)
2843                 return -ENAMETOOLONG;
2844
2845         dquot_initialize(dir);
2846
2847         if (l > EXT4_N_BLOCKS * 4) {
2848                 /*
2849                  * For non-fast symlinks, we just allocate inode and put it on
2850                  * orphan list in the first transaction => we need bitmap,
2851                  * group descriptor, sb, inode block, quota blocks, and
2852                  * possibly selinux xattr blocks.
2853                  */
2854                 credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
2855                           EXT4_XATTR_TRANS_BLOCKS;
2856         } else {
2857                 /*
2858                  * Fast symlink. We have to add entry to directory
2859                  * (EXT4_DATA_TRANS_BLOCKS + EXT4_INDEX_EXTRA_TRANS_BLOCKS),
2860                  * allocate new inode (bitmap, group descriptor, inode block,
2861                  * quota blocks, sb is already counted in previous macros).
2862                  */
2863                 credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2864                           EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
2865                           EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb);
2866         }
2867 retry:
2868         handle = ext4_journal_start(dir, credits);
2869         if (IS_ERR(handle))
2870                 return PTR_ERR(handle);
2871
2872         if (IS_DIRSYNC(dir))
2873                 ext4_handle_sync(handle);
2874
2875         inode = ext4_new_inode(handle, dir, S_IFLNK|S_IRWXUGO,
2876                                &dentry->d_name, 0, NULL);
2877         err = PTR_ERR(inode);
2878         if (IS_ERR(inode))
2879                 goto out_stop;
2880
2881         if (l > EXT4_N_BLOCKS * 4) {
2882                 inode->i_op = &ext4_symlink_inode_operations;
2883                 ext4_set_aops(inode);
2884                 /*
2885                  * We cannot call page_symlink() with transaction started
2886                  * because it calls into ext4_write_begin() which can wait
2887                  * for transaction commit if we are running out of space
2888                  * and thus we deadlock. So we have to stop transaction now
2889                  * and restart it when symlink contents is written.
2890                  *
2891                  * To keep fs consistent in case of crash, we have to put inode
2892                  * to orphan list in the mean time.
2893                  */
2894                 drop_nlink(inode);
2895                 err = ext4_orphan_add(handle, inode);
2896                 ext4_journal_stop(handle);
2897                 if (err)
2898                         goto err_drop_inode;
2899                 err = __page_symlink(inode, symname, l, 1);
2900                 if (err)
2901                         goto err_drop_inode;
2902                 /*
2903                  * Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS
2904                  * + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified
2905                  */
2906                 handle = ext4_journal_start(dir,
2907                                 EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2908                                 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1);
2909                 if (IS_ERR(handle)) {
2910                         err = PTR_ERR(handle);
2911                         goto err_drop_inode;
2912                 }
2913                 set_nlink(inode, 1);
2914                 err = ext4_orphan_del(handle, inode);
2915                 if (err) {
2916                         ext4_journal_stop(handle);
2917                         clear_nlink(inode);
2918                         goto err_drop_inode;
2919                 }
2920         } else {
2921                 /* clear the extent format for fast symlink */
2922                 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
2923                 inode->i_op = &ext4_fast_symlink_inode_operations;
2924                 memcpy((char *)&EXT4_I(inode)->i_data, symname, l);
2925                 inode->i_size = l-1;
2926         }
2927         EXT4_I(inode)->i_disksize = inode->i_size;
2928         err = ext4_add_nondir(handle, dentry, inode);
2929 out_stop:
2930         ext4_journal_stop(handle);
2931         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2932                 goto retry;
2933         return err;
2934 err_drop_inode:
2935         unlock_new_inode(inode);
2936         iput(inode);
2937         return err;
2938 }
2939
2940 static int ext4_link(struct dentry *old_dentry,
2941                      struct inode *dir, struct dentry *dentry)
2942 {
2943         handle_t *handle;
2944         struct inode *inode = old_dentry->d_inode;
2945         int err, retries = 0;
2946
2947         if (inode->i_nlink >= EXT4_LINK_MAX)
2948                 return -EMLINK;
2949
2950         dquot_initialize(dir);
2951
2952 retry:
2953         handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2954                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS);
2955         if (IS_ERR(handle))
2956                 return PTR_ERR(handle);
2957
2958         if (IS_DIRSYNC(dir))
2959                 ext4_handle_sync(handle);
2960
2961         inode->i_ctime = ext4_current_time(inode);
2962         ext4_inc_count(handle, inode);
2963         ihold(inode);
2964
2965         err = ext4_add_entry(handle, dentry, inode);
2966         if (!err) {
2967                 ext4_mark_inode_dirty(handle, inode);
2968                 d_instantiate(dentry, inode);
2969         } else {
2970                 drop_nlink(inode);
2971                 iput(inode);
2972         }
2973         ext4_journal_stop(handle);
2974         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2975                 goto retry;
2976         return err;
2977 }
2978
2979
2980 /*
2981  * Try to find buffer head where contains the parent block.
2982  * It should be the inode block if it is inlined or the 1st block
2983  * if it is a normal dir.
2984  */
2985 static struct buffer_head *ext4_get_first_dir_block(handle_t *handle,
2986                                         struct inode *inode,
2987                                         int *retval,
2988                                         struct ext4_dir_entry_2 **parent_de,
2989                                         int *inlined)
2990 {
2991         struct buffer_head *bh;
2992
2993         if (!ext4_has_inline_data(inode)) {
2994                 if (!(bh = ext4_bread(handle, inode, 0, 0, retval))) {
2995                         if (!*retval) {
2996                                 *retval = -EIO;
2997                                 ext4_error(inode->i_sb,
2998                                            "Directory hole detected on inode %lu\n",
2999                                            inode->i_ino);
3000                         }
3001                         return NULL;
3002                 }
3003                 *parent_de = ext4_next_entry(
3004                                         (struct ext4_dir_entry_2 *)bh->b_data,
3005                                         inode->i_sb->s_blocksize);
3006                 return bh;
3007         }
3008
3009         *inlined = 1;
3010         return ext4_get_first_inline_block(inode, parent_de, retval);
3011 }
3012
3013 /*
3014  * Anybody can rename anything with this: the permission checks are left to the
3015  * higher-level routines.
3016  */
3017 static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
3018                        struct inode *new_dir, struct dentry *new_dentry)
3019 {
3020         handle_t *handle;
3021         struct inode *old_inode, *new_inode;
3022         struct buffer_head *old_bh, *new_bh, *dir_bh;
3023         struct ext4_dir_entry_2 *old_de, *new_de;
3024         int retval, force_da_alloc = 0;
3025         int inlined = 0, new_inlined = 0;
3026         struct ext4_dir_entry_2 *parent_de;
3027
3028         dquot_initialize(old_dir);
3029         dquot_initialize(new_dir);
3030
3031         old_bh = new_bh = dir_bh = NULL;
3032
3033         /* Initialize quotas before so that eventual writes go
3034          * in separate transaction */
3035         if (new_dentry->d_inode)
3036                 dquot_initialize(new_dentry->d_inode);
3037         handle = ext4_journal_start(old_dir, 2 *
3038                                         EXT4_DATA_TRANS_BLOCKS(old_dir->i_sb) +
3039                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
3040         if (IS_ERR(handle))
3041                 return PTR_ERR(handle);
3042
3043         if (IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir))
3044                 ext4_handle_sync(handle);
3045
3046         old_bh = ext4_find_entry(old_dir, &old_dentry->d_name, &old_de, NULL);
3047         /*
3048          *  Check for inode number is _not_ due to possible IO errors.
3049          *  We might rmdir the source, keep it as pwd of some process
3050          *  and merrily kill the link to whatever was created under the
3051          *  same name. Goodbye sticky bit ;-<
3052          */
3053         old_inode = old_dentry->d_inode;
3054         retval = -ENOENT;
3055         if (!old_bh || le32_to_cpu(old_de->inode) != old_inode->i_ino)
3056                 goto end_rename;
3057
3058         new_inode = new_dentry->d_inode;
3059         new_bh = ext4_find_entry(new_dir, &new_dentry->d_name,
3060                                  &new_de, &new_inlined);
3061         if (new_bh) {
3062                 if (!new_inode) {
3063                         brelse(new_bh);
3064                         new_bh = NULL;
3065                 }
3066         }
3067         if (S_ISDIR(old_inode->i_mode)) {
3068                 if (new_inode) {
3069                         retval = -ENOTEMPTY;
3070                         if (!empty_dir(new_inode))
3071                                 goto end_rename;
3072                 }
3073                 retval = -EIO;
3074                 dir_bh = ext4_get_first_dir_block(handle, old_inode,
3075                                                   &retval, &parent_de,
3076                                                   &inlined);
3077                 if (!dir_bh)
3078                         goto end_rename;
3079                 if (!inlined && !buffer_verified(dir_bh) &&
3080                     !ext4_dirent_csum_verify(old_inode,
3081                                 (struct ext4_dir_entry *)dir_bh->b_data))
3082                         goto end_rename;
3083                 set_buffer_verified(dir_bh);
3084                 if (le32_to_cpu(parent_de->inode) != old_dir->i_ino)
3085                         goto end_rename;
3086                 retval = -EMLINK;
3087                 if (!new_inode && new_dir != old_dir &&
3088                     EXT4_DIR_LINK_MAX(new_dir))
3089                         goto end_rename;
3090                 BUFFER_TRACE(dir_bh, "get_write_access");
3091                 retval = ext4_journal_get_write_access(handle, dir_bh);
3092                 if (retval)
3093                         goto end_rename;
3094         }
3095         if (!new_bh) {
3096                 retval = ext4_add_entry(handle, new_dentry, old_inode);
3097                 if (retval)
3098                         goto end_rename;
3099         } else {
3100                 BUFFER_TRACE(new_bh, "get write access");
3101                 retval = ext4_journal_get_write_access(handle, new_bh);
3102                 if (retval)
3103                         goto end_rename;
3104                 new_de->inode = cpu_to_le32(old_inode->i_ino);
3105                 if (EXT4_HAS_INCOMPAT_FEATURE(new_dir->i_sb,
3106                                               EXT4_FEATURE_INCOMPAT_FILETYPE))
3107                         new_de->file_type = old_de->file_type;
3108                 new_dir->i_version++;
3109                 new_dir->i_ctime = new_dir->i_mtime =
3110                                         ext4_current_time(new_dir);
3111                 ext4_mark_inode_dirty(handle, new_dir);
3112                 BUFFER_TRACE(new_bh, "call ext4_handle_dirty_metadata");
3113                 if (!new_inlined) {
3114                         retval = ext4_handle_dirty_dirent_node(handle,
3115                                                                new_dir, new_bh);
3116                         if (unlikely(retval)) {
3117                                 ext4_std_error(new_dir->i_sb, retval);
3118                                 goto end_rename;
3119                         }
3120                 }
3121                 brelse(new_bh);
3122                 new_bh = NULL;
3123         }
3124
3125         /*
3126          * Like most other Unix systems, set the ctime for inodes on a
3127          * rename.
3128          */
3129         old_inode->i_ctime = ext4_current_time(old_inode);
3130         ext4_mark_inode_dirty(handle, old_inode);
3131
3132         /*
3133          * ok, that's it
3134          */
3135         if (le32_to_cpu(old_de->inode) != old_inode->i_ino ||
3136             old_de->name_len != old_dentry->d_name.len ||
3137             strncmp(old_de->name, old_dentry->d_name.name, old_de->name_len) ||
3138             (retval = ext4_delete_entry(handle, old_dir,
3139                                         old_de, old_bh)) == -ENOENT) {
3140                 /* old_de could have moved from under us during htree split, so
3141                  * make sure that we are deleting the right entry.  We might
3142                  * also be pointing to a stale entry in the unused part of
3143                  * old_bh so just checking inum and the name isn't enough. */
3144                 struct buffer_head *old_bh2;
3145                 struct ext4_dir_entry_2 *old_de2;
3146
3147                 old_bh2 = ext4_find_entry(old_dir, &old_dentry->d_name,
3148                                           &old_de2, NULL);
3149                 if (old_bh2) {
3150                         retval = ext4_delete_entry(handle, old_dir,
3151                                                    old_de2, old_bh2);
3152                         brelse(old_bh2);
3153                 }
3154         }
3155         if (retval) {
3156                 ext4_warning(old_dir->i_sb,
3157                                 "Deleting old file (%lu), %d, error=%d",
3158                                 old_dir->i_ino, old_dir->i_nlink, retval);
3159         }
3160
3161         if (new_inode) {
3162                 ext4_dec_count(handle, new_inode);
3163                 new_inode->i_ctime = ext4_current_time(new_inode);
3164         }
3165         old_dir->i_ctime = old_dir->i_mtime = ext4_current_time(old_dir);
3166         ext4_update_dx_flag(old_dir);
3167         if (dir_bh) {
3168                 parent_de->inode = cpu_to_le32(new_dir->i_ino);
3169                 BUFFER_TRACE(dir_bh, "call ext4_handle_dirty_metadata");
3170                 if (!inlined) {
3171                         if (is_dx(old_inode)) {
3172                                 retval = ext4_handle_dirty_dx_node(handle,
3173                                                                    old_inode,
3174                                                                    dir_bh);
3175                         } else {
3176                                 retval = ext4_handle_dirty_dirent_node(handle,
3177                                                         old_inode, dir_bh);
3178                         }
3179                 } else {
3180                         retval = ext4_mark_inode_dirty(handle, old_inode);
3181                 }
3182                 if (retval) {
3183                         ext4_std_error(old_dir->i_sb, retval);
3184                         goto end_rename;
3185                 }
3186                 ext4_dec_count(handle, old_dir);
3187                 if (new_inode) {
3188                         /* checked empty_dir above, can't have another parent,
3189                          * ext4_dec_count() won't work for many-linked dirs */
3190                         clear_nlink(new_inode);
3191                 } else {
3192                         ext4_inc_count(handle, new_dir);
3193                         ext4_update_dx_flag(new_dir);
3194                         ext4_mark_inode_dirty(handle, new_dir);
3195                 }
3196         }
3197         ext4_mark_inode_dirty(handle, old_dir);
3198         if (new_inode) {
3199                 ext4_mark_inode_dirty(handle, new_inode);
3200                 if (!new_inode->i_nlink)
3201                         ext4_orphan_add(handle, new_inode);
3202                 if (!test_opt(new_dir->i_sb, NO_AUTO_DA_ALLOC))
3203                         force_da_alloc = 1;
3204         }
3205         retval = 0;
3206
3207 end_rename:
3208         brelse(dir_bh);
3209         brelse(old_bh);
3210         brelse(new_bh);
3211         ext4_journal_stop(handle);
3212         if (retval == 0 && force_da_alloc)
3213                 ext4_alloc_da_blocks(old_inode);
3214         return retval;
3215 }
3216
3217 /*
3218  * directories can handle most operations...
3219  */
3220 const struct inode_operations ext4_dir_inode_operations = {
3221         .create         = ext4_create,
3222         .lookup         = ext4_lookup,
3223         .link           = ext4_link,
3224         .unlink         = ext4_unlink,
3225         .symlink        = ext4_symlink,
3226         .mkdir          = ext4_mkdir,
3227         .rmdir          = ext4_rmdir,
3228         .mknod          = ext4_mknod,
3229         .rename         = ext4_rename,
3230         .setattr        = ext4_setattr,
3231         .setxattr       = generic_setxattr,
3232         .getxattr       = generic_getxattr,
3233         .listxattr      = ext4_listxattr,
3234         .removexattr    = generic_removexattr,
3235         .get_acl        = ext4_get_acl,
3236         .fiemap         = ext4_fiemap,
3237 };
3238
3239 const struct inode_operations ext4_special_inode_operations = {
3240         .setattr        = ext4_setattr,
3241         .setxattr       = generic_setxattr,
3242         .getxattr       = generic_getxattr,
3243         .listxattr      = ext4_listxattr,
3244         .removexattr    = generic_removexattr,
3245         .get_acl        = ext4_get_acl,
3246 };