fs/ext4/namei.c

   1 /*
   2  *  linux/fs/ext4/namei.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card ([email protected])
   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 ([email protected]), 1995
  17  *  Directory entry file type support and forward compatibility hooks
  18  *      for B-tree directories by Theodore Ts'o ([email protected]), 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 /*
  44  * define how far ahead to read directories while searching them.
  45  */
  46 #define NAMEI_RA_CHUNKS  2
  47 #define NAMEI_RA_BLOCKS  4
  48 #define NAMEI_RA_SIZE        (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS)
  49 #define NAMEI_RA_INDEX(c,b)  (((c) * NAMEI_RA_BLOCKS) + (b))
  50
  51 static struct buffer_head *ext4_append(handle_t *handle,
  52                                         struct inode *inode,
  53                                         ext4_lblk_t *block, int *err)
  54 {
  55         struct buffer_head *bh;
  56
  57         *block = inode->i_size >> inode->i_sb->s_blocksize_bits;
  58
  59         bh = ext4_bread(handle, inode, *block, 1, err);
  60         if (bh) {
  61                 inode->i_size += inode->i_sb->s_blocksize;
  62                 EXT4_I(inode)->i_disksize = inode->i_size;
  63                 *err = ext4_journal_get_write_access(handle, bh);
  64                 if (*err) {
  65                         brelse(bh);
  66                         bh = NULL;
  67                 }
  68         }
  69         return bh;
  70 }
  71
  72 #ifndef assert
  73 #define assert(test) J_ASSERT(test)
  74 #endif
  75
  76 #ifdef DX_DEBUG
  77 #define dxtrace(command) command
  78 #else
  79 #define dxtrace(command)
  80 #endif
  81
  82 struct fake_dirent
  83 {
  84         __le32 inode;
  85         __le16 rec_len;
  86         u8 name_len;
  87         u8 file_type;
  88 };
  89
  90 struct dx_countlimit
  91 {
  92         __le16 limit;
  93         __le16 count;
  94 };
  95
  96 struct dx_entry
  97 {
  98         __le32 hash;
  99         __le32 block;
 100 };
 101
 102 /*
 103  * dx_root_info is laid out so that if it should somehow get overlaid by a
 104  * dirent the two low bits of the hash version will be zero.  Therefore, the
 105  * hash version mod 4 should never be 0.  Sincerely, the paranoia department.
 106  */
 107
 108 struct dx_root
 109 {
 110         struct fake_dirent dot;
 111         char dot_name[4];
 112         struct fake_dirent dotdot;
 113         char dotdot_name[4];
 114         struct dx_root_info
 115         {
 116                 __le32 reserved_zero;
 117                 u8 hash_version;
 118                 u8 info_length; /* 8 */
 119                 u8 indirect_levels;
 120                 u8 unused_flags;
 121         }
 122         info;
 123         struct dx_entry entries[0];
 124 };
 125
 126 struct dx_node
 127 {
 128         struct fake_dirent fake;
 129         struct dx_entry entries[0];
 130 };
 131
 132
 133 struct dx_frame
 134 {
 135         struct buffer_head *bh;
 136         struct dx_entry *entries;
 137         struct dx_entry *at;
 138 };
 139
 140 struct dx_map_entry
 141 {
 142         u32 hash;
 143         u16 offs;
 144         u16 size;
 145 };
 146
 147 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
 148 static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
 149 static inline unsigned dx_get_hash(struct dx_entry *entry);
 150 static void dx_set_hash(struct dx_entry *entry, unsigned value);
 151 static unsigned dx_get_count(struct dx_entry *entries);
 152 static unsigned dx_get_limit(struct dx_entry *entries);
 153 static void dx_set_count(struct dx_entry *entries, unsigned value);
 154 static void dx_set_limit(struct dx_entry *entries, unsigned value);
 155 static unsigned dx_root_limit(struct inode *dir, unsigned infosize);
 156 static unsigned dx_node_limit(struct inode *dir);
 157 static struct dx_frame *dx_probe(const struct qstr *d_name,
 158                                  struct inode *dir,
 159                                  struct dx_hash_info *hinfo,
 160                                  struct dx_frame *frame,
 161                                  int *err);
 162 static void dx_release(struct dx_frame *frames);
 163 static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize,
 164                        struct dx_hash_info *hinfo, struct dx_map_entry map[]);
 165 static void dx_sort_map(struct dx_map_entry *map, unsigned count);
 166 static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to,
 167                 struct dx_map_entry *offsets, int count, unsigned blocksize);
 168 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize);
 169 static void dx_insert_block(struct dx_frame *frame,
 170                                         u32 hash, ext4_lblk_t block);
 171 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
 172                                  struct dx_frame *frame,
 173                                  struct dx_frame *frames,
 174                                  __u32 *start_hash);
 175 static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
 176                 const struct qstr *d_name,
 177                 struct ext4_dir_entry_2 **res_dir,
 178                 int *err);
 179 static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
 180                              struct inode *inode);
 181
 182 /*
 183  * p is at least 6 bytes before the end of page
 184  */
 185 static inline struct ext4_dir_entry_2 *
 186 ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
 187 {
 188         return (struct ext4_dir_entry_2 *)((char *)p +
 189                 ext4_rec_len_from_disk(p->rec_len, blocksize));
 190 }
 191
 192 /*
 193  * Future: use high four bits of block for coalesce-on-delete flags
 194  * Mask them off for now.
 195  */
 196
 197 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
 198 {
 199         return le32_to_cpu(entry->block) & 0x00ffffff;
 200 }
 201
 202 static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
 203 {
 204         entry->block = cpu_to_le32(value);
 205 }
 206
 207 static inline unsigned dx_get_hash(struct dx_entry *entry)
 208 {
 209         return le32_to_cpu(entry->hash);
 210 }
 211
 212 static inline void dx_set_hash(struct dx_entry *entry, unsigned value)
 213 {
 214         entry->hash = cpu_to_le32(value);
 215 }
 216
 217 static inline unsigned dx_get_count(struct dx_entry *entries)
 218 {
 219         return le16_to_cpu(((struct dx_countlimit *) entries)->count);
 220 }
 221
 222 static inline unsigned dx_get_limit(struct dx_entry *entries)
 223 {
 224         return le16_to_cpu(((struct dx_countlimit *) entries)->limit);
 225 }
 226
 227 static inline void dx_set_count(struct dx_entry *entries, unsigned value)
 228 {
 229         ((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
 230 }
 231
 232 static inline void dx_set_limit(struct dx_entry *entries, unsigned value)
 233 {
 234         ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
 235 }
 236
 237 static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
 238 {
 239         unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
 240                 EXT4_DIR_REC_LEN(2) - infosize;
 241         return entry_space / sizeof(struct dx_entry);
 242 }
 243
 244 static inline unsigned dx_node_limit(struct inode *dir)
 245 {
 246         unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);
 247         return entry_space / sizeof(struct dx_entry);
 248 }
 249
 250 /*
 251  * Debug
 252  */
 253 #ifdef DX_DEBUG
 254 static void dx_show_index(char * label, struct dx_entry *entries)
 255 {
 256         int i, n = dx_get_count (entries);
 257         printk(KERN_DEBUG "%s index ", label);
 258         for (i = 0; i < n; i++) {
 259                 printk("%x->%lu ", i ? dx_get_hash(entries + i) :
 260                                 0, (unsigned long)dx_get_block(entries + i));
 261         }
 262         printk("\n");
 263 }
 264
 265 struct stats
 266 {
 267         unsigned names;
 268         unsigned space;
 269         unsigned bcount;
 270 };
 271
 272 static struct stats dx_show_leaf(struct dx_hash_info *hinfo, struct ext4_dir_entry_2 *de,
 273                                  int size, int show_names)
 274 {
 275         unsigned names = 0, space = 0;
 276         char *base = (char *) de;
 277         struct dx_hash_info h = *hinfo;
 278
 279         printk("names: ");
 280         while ((char *) de < base + size)
 281         {
 282                 if (de->inode)
 283                 {
 284                         if (show_names)
 285                         {
 286                                 int len = de->name_len;
 287                                 char *name = de->name;
 288                                 while (len--) printk("%c", *name++);
 289                                 ext4fs_dirhash(de->name, de->name_len, &h);
 290                                 printk(":%x.%u ", h.hash,
 291                                        ((char *) de - base));
 292                         }
 293                         space += EXT4_DIR_REC_LEN(de->name_len);
 294                         names++;
 295                 }
 296                 de = ext4_next_entry(de, size);
 297         }
 298         printk("(%i)\n", names);
 299         return (struct stats) { names, space, 1 };
 300 }
 301
 302 struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
 303                              struct dx_entry *entries, int levels)
 304 {
 305         unsigned blocksize = dir->i_sb->s_blocksize;
 306         unsigned count = dx_get_count(entries), names = 0, space = 0, i;
 307         unsigned bcount = 0;
 308         struct buffer_head *bh;
 309         int err;
 310         printk("%i indexed blocks...\n", count);
 311         for (i = 0; i < count; i++, entries++)
 312         {
 313                 ext4_lblk_t block = dx_get_block(entries);
 314                 ext4_lblk_t hash  = i ? dx_get_hash(entries): 0;
 315                 u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
 316                 struct stats stats;
 317                 printk("%s%3u:%03u hash %8x/%8x ",levels?"":"   ", i, block, hash, range);
 318                 if (!(bh = ext4_bread (NULL,dir, block, 0,&err))) continue;
 319                 stats = levels?
 320                    dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
 321                    dx_show_leaf(hinfo, (struct ext4_dir_entry_2 *) bh->b_data, blocksize, 0);
 322                 names += stats.names;
 323                 space += stats.space;
 324                 bcount += stats.bcount;
 325                 brelse(bh);
 326         }
 327         if (bcount)
 328                 printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n",
 329                        levels ? "" : "   ", names, space/bcount,
 330                        (space/bcount)*100/blocksize);
 331         return (struct stats) { names, space, bcount};
 332 }
 333 #endif /* DX_DEBUG */
 334
 335 /*
 336  * Probe for a directory leaf block to search.
 337  *
 338  * dx_probe can return ERR_BAD_DX_DIR, which means there was a format
 339  * error in the directory index, and the caller should fall back to
 340  * searching the directory normally.  The callers of dx_probe **MUST**
 341  * check for this error code, and make sure it never gets reflected
 342  * back to userspace.
 343  */
 344 static struct dx_frame *
 345 dx_probe(const struct qstr *d_name, struct inode *dir,
 346          struct dx_hash_info *hinfo, struct dx_frame *frame_in, int *err)
 347 {
 348         unsigned count, indirect;
 349         struct dx_entry *at, *entries, *p, *q, *m;
 350         struct dx_root *root;
 351         struct buffer_head *bh;
 352         struct dx_frame *frame = frame_in;
 353         u32 hash;
 354
 355         frame->bh = NULL;
 356         if (!(bh = ext4_bread (NULL,dir, 0, 0, err)))
 357                 goto fail;
 358         root = (struct dx_root *) bh->b_data;
 359         if (root->info.hash_version != DX_HASH_TEA &&
 360             root->info.hash_version != DX_HASH_HALF_MD4 &&
 361             root->info.hash_version != DX_HASH_LEGACY) {
 362                 ext4_warning(dir->i_sb, "Unrecognised inode hash code %d",
 363                              root->info.hash_version);
 364                 brelse(bh);
 365                 *err = ERR_BAD_DX_DIR;
 366                 goto fail;
 367         }
 368         hinfo->hash_version = root->info.hash_version;
 369         if (hinfo->hash_version <= DX_HASH_TEA)
 370                 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
 371         hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
 372         if (d_name)
 373                 ext4fs_dirhash(d_name->name, d_name->len, hinfo);
 374         hash = hinfo->hash;
 375
 376         if (root->info.unused_flags & 1) {
 377                 ext4_warning(dir->i_sb, "Unimplemented inode hash flags: %#06x",
 378                              root->info.unused_flags);
 379                 brelse(bh);
 380                 *err = ERR_BAD_DX_DIR;
 381                 goto fail;
 382         }
 383
 384         if ((indirect = root->info.indirect_levels) > 1) {
 385                 ext4_warning(dir->i_sb, "Unimplemented inode hash depth: %#06x",
 386                              root->info.indirect_levels);
 387                 brelse(bh);
 388                 *err = ERR_BAD_DX_DIR;
 389                 goto fail;
 390         }
 391
 392         entries = (struct dx_entry *) (((char *)&root->info) +
 393                                        root->info.info_length);
 394
 395         if (dx_get_limit(entries) != dx_root_limit(dir,
 396                                                    root->info.info_length)) {
 397                 ext4_warning(dir->i_sb, "dx entry: limit != root limit");
 398                 brelse(bh);
 399                 *err = ERR_BAD_DX_DIR;
 400                 goto fail;
 401         }
 402
 403         dxtrace(printk("Look up %x", hash));
 404         while (1)
 405         {
 406                 count = dx_get_count(entries);
 407                 if (!count || count > dx_get_limit(entries)) {
 408                         ext4_warning(dir->i_sb,
 409                                      "dx entry: no count or count > limit");
 410                         brelse(bh);
 411                         *err = ERR_BAD_DX_DIR;
 412                         goto fail2;
 413                 }
 414
 415                 p = entries + 1;
 416                 q = entries + count - 1;
 417                 while (p <= q)
 418                 {
 419                         m = p + (q - p)/2;
 420                         dxtrace(printk("."));
 421                         if (dx_get_hash(m) > hash)
 422                                 q = m - 1;
 423                         else
 424                                 p = m + 1;
 425                 }
 426
 427                 if (0) // linear search cross check
 428                 {
 429                         unsigned n = count - 1;
 430                         at = entries;
 431                         while (n--)
 432                         {
 433                                 dxtrace(printk(","));
 434                                 if (dx_get_hash(++at) > hash)
 435                                 {
 436                                         at--;
 437                                         break;
 438                                 }
 439                         }
 440                         assert (at == p - 1);
 441                 }
 442
 443                 at = p - 1;
 444                 dxtrace(printk(" %x->%u\n", at == entries? 0: dx_get_hash(at), dx_get_block(at)));
 445                 frame->bh = bh;
 446                 frame->entries = entries;
 447                 frame->at = at;
 448                 if (!indirect--) return frame;
 449                 if (!(bh = ext4_bread (NULL,dir, dx_get_block(at), 0, err)))
 450                         goto fail2;
 451                 at = entries = ((struct dx_node *) bh->b_data)->entries;
 452                 if (dx_get_limit(entries) != dx_node_limit (dir)) {
 453                         ext4_warning(dir->i_sb,
 454                                      "dx entry: limit != node limit");
 455                         brelse(bh);
 456                         *err = ERR_BAD_DX_DIR;
 457                         goto fail2;
 458                 }
 459                 frame++;
 460                 frame->bh = NULL;
 461         }
 462 fail2:
 463         while (frame >= frame_in) {
 464                 brelse(frame->bh);
 465                 frame--;
 466         }
 467 fail:
 468         if (*err == ERR_BAD_DX_DIR)
 469                 ext4_warning(dir->i_sb,
 470                              "Corrupt dir inode %ld, running e2fsck is "
 471                              "recommended.", dir->i_ino);
 472         return NULL;
 473 }
 474
 475 static void dx_release (struct dx_frame *frames)
 476 {
 477         if (frames[0].bh == NULL)
 478                 return;
 479
 480         if (((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels)
 481                 brelse(frames[1].bh);
 482         brelse(frames[0].bh);
 483 }
 484
 485 /*
 486  * This function increments the frame pointer to search the next leaf
 487  * block, and reads in the necessary intervening nodes if the search
 488  * should be necessary.  Whether or not the search is necessary is
 489  * controlled by the hash parameter.  If the hash value is even, then
 490  * the search is only continued if the next block starts with that
 491  * hash value.  This is used if we are searching for a specific file.
 492  *
 493  * If the hash value is HASH_NB_ALWAYS, then always go to the next block.
 494  *
 495  * This function returns 1 if the caller should continue to search,
 496  * or 0 if it should not.  If there is an error reading one of the
 497  * index blocks, it will a negative error code.
 498  *
 499  * If start_hash is non-null, it will be filled in with the starting
 500  * hash of the next page.
 501  */
 502 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
 503                                  struct dx_frame *frame,
 504                                  struct dx_frame *frames,
 505                                  __u32 *start_hash)
 506 {
 507         struct dx_frame *p;
 508         struct buffer_head *bh;
 509         int err, num_frames = 0;
 510         __u32 bhash;
 511
 512         p = frame;
 513         /*
 514          * Find the next leaf page by incrementing the frame pointer.
 515          * If we run out of entries in the interior node, loop around and
 516          * increment pointer in the parent node.  When we break out of
 517          * this loop, num_frames indicates the number of interior
 518          * nodes need to be read.
 519          */
 520         while (1) {
 521                 if (++(p->at) < p->entries + dx_get_count(p->entries))
 522                         break;
 523                 if (p == frames)
 524                         return 0;
 525                 num_frames++;
 526                 p--;
 527         }
 528
 529         /*
 530          * If the hash is 1, then continue only if the next page has a
 531          * continuation hash of any value.  This is used for readdir
 532          * handling.  Otherwise, check to see if the hash matches the
 533          * desired contiuation hash.  If it doesn't, return since
 534          * there's no point to read in the successive index pages.
 535          */
 536         bhash = dx_get_hash(p->at);
 537         if (start_hash)
 538                 *start_hash = bhash;
 539         if ((hash & 1) == 0) {
 540                 if ((bhash & ~1) != hash)
 541                         return 0;
 542         }
 543         /*
 544          * If the hash is HASH_NB_ALWAYS, we always go to the next
 545          * block so no check is necessary
 546          */
 547         while (num_frames--) {
 548                 if (!(bh = ext4_bread(NULL, dir, dx_get_block(p->at),
 549                                       0, &err)))
 550                         return err; /* Failure */
 551                 p++;
 552                 brelse(p->bh);
 553                 p->bh = bh;
 554                 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
 555         }
 556         return 1;
 557 }
 558
 559
 560 /*
 561  * This function fills a red-black tree with information from a
 562  * directory block.  It returns the number directory entries loaded
 563  * into the tree.  If there is an error it is returned in err.
 564  */
 565 static int htree_dirblock_to_tree(struct file *dir_file,
 566                                   struct inode *dir, ext4_lblk_t block,
 567                                   struct dx_hash_info *hinfo,
 568                                   __u32 start_hash, __u32 start_minor_hash)
 569 {
 570         struct buffer_head *bh;
 571         struct ext4_dir_entry_2 *de, *top;
 572         int err, count = 0;
 573
 574         dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
 575                                                         (unsigned long)block));
 576         if (!(bh = ext4_bread (NULL, dir, block, 0, &err)))
 577                 return err;
 578
 579         de = (struct ext4_dir_entry_2 *) bh->b_data;
 580         top = (struct ext4_dir_entry_2 *) ((char *) de +
 581                                            dir->i_sb->s_blocksize -
 582                                            EXT4_DIR_REC_LEN(0));
 583         for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) {
 584                 if (ext4_check_dir_entry(dir, NULL, de, bh,
 585                                 (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
 586                                          + ((char *)de - bh->b_data))) {
 587                         /* On error, skip the f_pos to the next block. */
 588                         dir_file->f_pos = (dir_file->f_pos |
 589                                         (dir->i_sb->s_blocksize - 1)) + 1;
 590                         brelse(bh);
 591                         return count;
 592                 }
 593                 ext4fs_dirhash(de->name, de->name_len, hinfo);
 594                 if ((hinfo->hash < start_hash) ||
 595                     ((hinfo->hash == start_hash) &&
 596                      (hinfo->minor_hash < start_minor_hash)))
 597                         continue;
 598                 if (de->inode == 0)
 599                         continue;
 600                 if ((err = ext4_htree_store_dirent(dir_file,
 601                                    hinfo->hash, hinfo->minor_hash, de)) != 0) {
 602                         brelse(bh);
 603                         return err;
 604                 }
 605                 count++;
 606         }
 607         brelse(bh);
 608         return count;
 609 }
 610
 611
 612 /*
 613  * This function fills a red-black tree with information from a
 614  * directory.  We start scanning the directory in hash order, starting
 615  * at start_hash and start_minor_hash.
 616  *
 617  * This function returns the number of entries inserted into the tree,
 618  * or a negative error code.
 619  */
 620 int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
 621                          __u32 start_minor_hash, __u32 *next_hash)
 622 {
 623         struct dx_hash_info hinfo;
 624         struct ext4_dir_entry_2 *de;
 625         struct dx_frame frames[2], *frame;
 626         struct inode *dir;
 627         ext4_lblk_t block;
 628         int count = 0;
 629         int ret, err;
 630         __u32 hashval;
 631
 632         dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
 633                        start_hash, start_minor_hash));
 634         dir = dir_file->f_path.dentry->d_inode;
 635         if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) {
 636                 hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
 637                 if (hinfo.hash_version <= DX_HASH_TEA)
 638                         hinfo.hash_version +=
 639                                 EXT4_SB(dir->i_sb)->s_hash_unsigned;
 640                 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
 641                 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
 642                                                start_hash, start_minor_hash);
 643                 *next_hash = ~0;
 644                 return count;
 645         }
 646         hinfo.hash = start_hash;
 647         hinfo.minor_hash = 0;
 648         frame = dx_probe(NULL, dir, &hinfo, frames, &err);
 649         if (!frame)
 650                 return err;
 651
 652         /* Add '.' and '..' from the htree header */
 653         if (!start_hash && !start_minor_hash) {
 654                 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
 655                 if ((err = ext4_htree_store_dirent(dir_file, 0, 0, de)) != 0)
 656                         goto errout;
 657                 count++;
 658         }
 659         if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
 660                 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
 661                 de = ext4_next_entry(de, dir->i_sb->s_blocksize);
 662                 if ((err = ext4_htree_store_dirent(dir_file, 2, 0, de)) != 0)
 663                         goto errout;
 664                 count++;
 665         }
 666
 667         while (1) {
 668                 block = dx_get_block(frame->at);
 669                 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
 670                                              start_hash, start_minor_hash);
 671                 if (ret < 0) {
 672                         err = ret;
 673                         goto errout;
 674                 }
 675                 count += ret;
 676                 hashval = ~0;
 677                 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
 678                                             frame, frames, &hashval);
 679                 *next_hash = hashval;
 680                 if (ret < 0) {
 681                         err = ret;
 682                         goto errout;
 683                 }
 684                 /*
 685                  * Stop if:  (a) there are no more entries, or
 686                  * (b) we have inserted at least one entry and the
 687                  * next hash value is not a continuation
 688                  */
 689                 if ((ret == 0) ||
 690                     (count && ((hashval & 1) == 0)))
 691                         break;
 692         }
 693         dx_release(frames);
 694         dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, "
 695                        "next hash: %x\n", count, *next_hash));
 696         return count;
 697 errout:
 698         dx_release(frames);
 699         return (err);
 700 }
 701
 702
 703 /*
 704  * Directory block splitting, compacting
 705  */
 706
 707 /*
 708  * Create map of hash values, offsets, and sizes, stored at end of block.
 709  * Returns number of entries mapped.
 710  */
 711 static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize,
 712                        struct dx_hash_info *hinfo,
 713                        struct dx_map_entry *map_tail)
 714 {
 715         int count = 0;
 716         char *base = (char *) de;
 717         struct dx_hash_info h = *hinfo;
 718
 719         while ((char *) de < base + blocksize) {
 720                 if (de->name_len && de->inode) {
 721                         ext4fs_dirhash(de->name, de->name_len, &h);
 722                         map_tail--;
 723                         map_tail->hash = h.hash;
 724                         map_tail->offs = ((char *) de - base)>>2;
 725                         map_tail->size = le16_to_cpu(de->rec_len);
 726                         count++;
 727                         cond_resched();
 728                 }
 729                 /* XXX: do we need to check rec_len == 0 case? -Chris */
 730                 de = ext4_next_entry(de, blocksize);
 731         }
 732         return count;
 733 }
 734
 735 /* Sort map by hash value */
 736 static void dx_sort_map (struct dx_map_entry *map, unsigned count)
 737 {
 738         struct dx_map_entry *p, *q, *top = map + count - 1;
 739         int more;
 740         /* Combsort until bubble sort doesn't suck */
 741         while (count > 2) {
 742                 count = count*10/13;
 743                 if (count - 9 < 2) /* 9, 10 -> 11 */
 744                         count = 11;
 745                 for (p = top, q = p - count; q >= map; p--, q--)
 746                         if (p->hash < q->hash)
 747                                 swap(*p, *q);
 748         }
 749         /* Garden variety bubble sort */
 750         do {
 751                 more = 0;
 752                 q = top;
 753                 while (q-- > map) {
 754                         if (q[1].hash >= q[0].hash)
 755                                 continue;
 756                         swap(*(q+1), *q);
 757                         more = 1;
 758                 }
 759         } while(more);
 760 }
 761
 762 static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
 763 {
 764         struct dx_entry *entries = frame->entries;
 765         struct dx_entry *old = frame->at, *new = old + 1;
 766         int count = dx_get_count(entries);
 767
 768         assert(count < dx_get_limit(entries));
 769         assert(old < entries + count);
 770         memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
 771         dx_set_hash(new, hash);
 772         dx_set_block(new, block);
 773         dx_set_count(entries, count + 1);
 774 }
 775
 776 static void ext4_update_dx_flag(struct inode *inode)
 777 {
 778         if (!EXT4_HAS_COMPAT_FEATURE(inode->i_sb,
 779                                      EXT4_FEATURE_COMPAT_DIR_INDEX))
 780                 ext4_clear_inode_flag(inode, EXT4_INODE_INDEX);
 781 }
 782
 783 /*
 784  * NOTE! unlike strncmp, ext4_match returns 1 for success, 0 for failure.
 785  *
 786  * `len <= EXT4_NAME_LEN' is guaranteed by caller.
 787  * `de != NULL' is guaranteed by caller.
 788  */
 789 static inline int ext4_match (int len, const char * const name,
 790                               struct ext4_dir_entry_2 * de)
 791 {
 792         if (len != de->name_len)
 793                 return 0;
 794         if (!de->inode)
 795                 return 0;
 796         return !memcmp(name, de->name, len);
 797 }
 798
 799 /*
 800  * Returns 0 if not found, -1 on failure, and 1 on success
 801  */
 802 static inline int search_dirblock(struct buffer_head *bh,
 803                                   struct inode *dir,
 804                                   const struct qstr *d_name,
 805                                   unsigned int offset,
 806                                   struct ext4_dir_entry_2 ** res_dir)
 807 {
 808         struct ext4_dir_entry_2 * de;
 809         char * dlimit;
 810         int de_len;
 811         const char *name = d_name->name;
 812         int namelen = d_name->len;
 813
 814         de = (struct ext4_dir_entry_2 *) bh->b_data;
 815         dlimit = bh->b_data + dir->i_sb->s_blocksize;
 816         while ((char *) de < dlimit) {
 817                 /* this code is executed quadratically often */
 818                 /* do minimal checking `by hand' */
 819
 820                 if ((char *) de + namelen <= dlimit &&
 821                     ext4_match (namelen, name, de)) {
 822                         /* found a match - just to be sure, do a full check */
 823                         if (ext4_check_dir_entry(dir, NULL, de, bh, offset))
 824                                 return -1;
 825                         *res_dir = de;
 826                         return 1;
 827                 }
 828                 /* prevent looping on a bad block */
 829                 de_len = ext4_rec_len_from_disk(de->rec_len,
 830                                                 dir->i_sb->s_blocksize);
 831                 if (de_len <= 0)
 832                         return -1;
 833                 offset += de_len;
 834                 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
 835         }
 836         return 0;
 837 }
 838
 839
 840 /*
 841  *      ext4_find_entry()
 842  *
 843  * finds an entry in the specified directory with the wanted name. It
 844  * returns the cache buffer in which the entry was found, and the entry
 845  * itself (as a parameter - res_dir). It does NOT read the inode of the
 846  * entry - you'll have to do that yourself if you want to.
 847  *
 848  * The returned buffer_head has ->b_count elevated.  The caller is expected
 849  * to brelse() it when appropriate.
 850  */
 851 static struct buffer_head * ext4_find_entry (struct inode *dir,
 852                                         const struct qstr *d_name,
 853                                         struct ext4_dir_entry_2 ** res_dir)
 854 {
 855         struct super_block *sb;
 856         struct buffer_head *bh_use[NAMEI_RA_SIZE];
 857         struct buffer_head *bh, *ret = NULL;
 858         ext4_lblk_t start, block, b;
 859         const u8 *name = d_name->name;
 860         int ra_max = 0;         /* Number of bh's in the readahead
 861                                    buffer, bh_use[] */
 862         int ra_ptr = 0;         /* Current index into readahead
 863                                    buffer */
 864         int num = 0;
 865         ext4_lblk_t  nblocks;
 866         int i, err;
 867         int namelen;
 868
 869         *res_dir = NULL;
 870         sb = dir->i_sb;
 871         namelen = d_name->len;
 872         if (namelen > EXT4_NAME_LEN)
 873                 return NULL;
 874         if ((namelen <= 2) && (name[0] == '.') &&
 875             (name[1] == '.' || name[1] == '\0')) {
 876                 /*
 877                  * "." or ".." will only be in the first block
 878                  * NFS may look up ".."; "." should be handled by the VFS
 879                  */
 880                 block = start = 0;
 881                 nblocks = 1;
 882                 goto restart;
 883         }
 884         if (is_dx(dir)) {
 885                 bh = ext4_dx_find_entry(dir, d_name, res_dir, &err);
 886                 /*
 887                  * On success, or if the error was file not found,
 888                  * return.  Otherwise, fall back to doing a search the
 889                  * old fashioned way.
 890                  */
 891                 if (bh || (err != ERR_BAD_DX_DIR))
 892                         return bh;
 893                 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
 894                                "falling back\n"));
 895         }
 896         nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
 897         start = EXT4_I(dir)->i_dir_start_lookup;
 898         if (start >= nblocks)
 899                 start = 0;
 900         block = start;
 901 restart:
 902         do {
 903                 /*
 904                  * We deal with the read-ahead logic here.
 905                  */
 906                 if (ra_ptr >= ra_max) {
 907                         /* Refill the readahead buffer */
 908                         ra_ptr = 0;
 909                         b = block;
 910                         for (ra_max = 0; ra_max < NAMEI_RA_SIZE; ra_max++) {
 911                                 /*
 912                                  * Terminate if we reach the end of the
 913                                  * directory and must wrap, or if our
 914                                  * search has finished at this block.
 915                                  */
 916                                 if (b >= nblocks || (num && block == start)) {
 917                                         bh_use[ra_max] = NULL;
 918                                         break;
 919                                 }
 920                                 num++;
 921                                 bh = ext4_getblk(NULL, dir, b++, 0, &err);
 922                                 bh_use[ra_max] = bh;
 923                                 if (bh)
 924                                         ll_rw_block(READ_META, 1, &bh);
 925                         }
 926                 }
 927                 if ((bh = bh_use[ra_ptr++]) == NULL)
 928                         goto next;
 929                 wait_on_buffer(bh);
 930                 if (!buffer_uptodate(bh)) {
 931                         /* read error, skip block & hope for the best */
 932                         EXT4_ERROR_INODE(dir, "reading directory lblock %lu",
 933                                          (unsigned long) block);
 934                         brelse(bh);
 935                         goto next;
 936                 }
 937                 i = search_dirblock(bh, dir, d_name,
 938                             block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
 939                 if (i == 1) {
 940                         EXT4_I(dir)->i_dir_start_lookup = block;
 941                         ret = bh;
 942                         goto cleanup_and_exit;
 943                 } else {
 944                         brelse(bh);
 945                         if (i < 0)
 946                                 goto cleanup_and_exit;
 947                 }
 948         next:
 949                 if (++block >= nblocks)
 950                         block = 0;
 951         } while (block != start);
 952
 953         /*
 954          * If the directory has grown while we were searching, then
 955          * search the last part of the directory before giving up.
 956          */
 957         block = nblocks;
 958         nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
 959         if (block < nblocks) {
 960                 start = 0;
 961                 goto restart;
 962         }
 963
 964 cleanup_and_exit:
 965         /* Clean up the read-ahead blocks */
 966         for (; ra_ptr < ra_max; ra_ptr++)
 967                 brelse(bh_use[ra_ptr]);
 968         return ret;
 969 }
 970
 971 static struct buffer_head * ext4_dx_find_entry(struct inode *dir, const struct qstr *d_name,
 972                        struct ext4_dir_entry_2 **res_dir, int *err)
 973 {
 974         struct super_block * sb = dir->i_sb;
 975         struct dx_hash_info     hinfo;
 976         struct dx_frame frames[2], *frame;
 977         struct buffer_head *bh;
 978         ext4_lblk_t block;
 979         int retval;
 980
 981         if (!(frame = dx_probe(d_name, dir, &hinfo, frames, err)))
 982                 return NULL;
 983         do {
 984                 block = dx_get_block(frame->at);
 985                 if (!(bh = ext4_bread(NULL, dir, block, 0, err)))
 986                         goto errout;
 987
 988                 retval = search_dirblock(bh, dir, d_name,
 989                                          block << EXT4_BLOCK_SIZE_BITS(sb),
 990                                          res_dir);
 991                 if (retval == 1) {      /* Success! */
 992                         dx_release(frames);
 993                         return bh;
 994                 }
 995                 brelse(bh);
 996                 if (retval == -1) {
 997                         *err = ERR_BAD_DX_DIR;
 998                         goto errout;
 999                 }
1000
1001                 /* Check to see if we should continue to search */
1002                 retval = ext4_htree_next_block(dir, hinfo.hash, frame,
1003                                                frames, NULL);
1004                 if (retval < 0) {
1005                         ext4_warning(sb,
1006                              "error reading index page in directory #%lu",
1007                              dir->i_ino);
1008                         *err = retval;
1009                         goto errout;
1010                 }
1011         } while (retval == 1);
1012
1013         *err = -ENOENT;
1014 errout:
1015         dxtrace(printk(KERN_DEBUG "%s not found\n", name));
1016         dx_release (frames);
1017         return NULL;
1018 }
1019
1020 static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
1021 {
1022         struct inode *inode;
1023         struct ext4_dir_entry_2 *de;
1024         struct buffer_head *bh;
1025
1026         if (dentry->d_name.len > EXT4_NAME_LEN)
1027                 return ERR_PTR(-ENAMETOOLONG);
1028
1029         bh = ext4_find_entry(dir, &dentry->d_name, &de);
1030         inode = NULL;
1031         if (bh) {
1032                 __u32 ino = le32_to_cpu(de->inode);
1033                 brelse(bh);
1034                 if (!ext4_valid_inum(dir->i_sb, ino)) {
1035                         EXT4_ERROR_INODE(dir, "bad inode number: %u", ino);
1036                         return ERR_PTR(-EIO);
1037                 }
1038                 inode = ext4_iget(dir->i_sb, ino);
1039                 if (IS_ERR(inode)) {
1040                         if (PTR_ERR(inode) == -ESTALE) {
1041                                 EXT4_ERROR_INODE(dir,
1042                                                  "deleted inode referenced: %u",
1043                                                  ino);
1044                                 return ERR_PTR(-EIO);
1045                         } else {
1046                                 return ERR_CAST(inode);
1047                         }
1048                 }
1049         }
1050         return d_splice_alias(inode, dentry);
1051 }
1052
1053
1054 struct dentry *ext4_get_parent(struct dentry *child)
1055 {
1056         __u32 ino;
1057         static const struct qstr dotdot = {
1058                 .name = "..",
1059                 .len = 2,
1060         };
1061         struct ext4_dir_entry_2 * de;
1062         struct buffer_head *bh;
1063
1064         bh = ext4_find_entry(child->d_inode, &dotdot, &de);
1065         if (!bh)
1066                 return ERR_PTR(-ENOENT);
1067         ino = le32_to_cpu(de->inode);
1068         brelse(bh);
1069
1070         if (!ext4_valid_inum(child->d_inode->i_sb, ino)) {
1071                 EXT4_ERROR_INODE(child->d_inode,
1072                                  "bad parent inode number: %u", ino);
1073                 return ERR_PTR(-EIO);
1074         }
1075
1076         return d_obtain_alias(ext4_iget(child->d_inode->i_sb, ino));
1077 }
1078
1079 #define S_SHIFT 12
1080 static unsigned char ext4_type_by_mode[S_IFMT >> S_SHIFT] = {
1081         [S_IFREG >> S_SHIFT]    = EXT4_FT_REG_FILE,
1082         [S_IFDIR >> S_SHIFT]    = EXT4_FT_DIR,
1083         [S_IFCHR >> S_SHIFT]    = EXT4_FT_CHRDEV,
1084         [S_IFBLK >> S_SHIFT]    = EXT4_FT_BLKDEV,
1085         [S_IFIFO >> S_SHIFT]    = EXT4_FT_FIFO,
1086         [S_IFSOCK >> S_SHIFT]   = EXT4_FT_SOCK,
1087         [S_IFLNK >> S_SHIFT]    = EXT4_FT_SYMLINK,
1088 };
1089
1090 static inline void ext4_set_de_type(struct super_block *sb,
1091                                 struct ext4_dir_entry_2 *de,
1092                                 umode_t mode) {
1093         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE))
1094                 de->file_type = ext4_type_by_mode[(mode & S_IFMT)>>S_SHIFT];
1095 }
1096
1097 /*
1098  * Move count entries from end of map between two memory locations.
1099  * Returns pointer to last entry moved.
1100  */
1101 static struct ext4_dir_entry_2 *
1102 dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count,
1103                 unsigned blocksize)
1104 {
1105         unsigned rec_len = 0;
1106
1107         while (count--) {
1108                 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
1109                                                 (from + (map->offs<<2));
1110                 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1111                 memcpy (to, de, rec_len);
1112                 ((struct ext4_dir_entry_2 *) to)->rec_len =
1113                                 ext4_rec_len_to_disk(rec_len, blocksize);
1114                 de->inode = 0;
1115                 map++;
1116                 to += rec_len;
1117         }
1118         return (struct ext4_dir_entry_2 *) (to - rec_len);
1119 }
1120
1121 /*
1122  * Compact each dir entry in the range to the minimal rec_len.
1123  * Returns pointer to last entry in range.
1124  */
1125 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize)
1126 {
1127         struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
1128         unsigned rec_len = 0;
1129
1130         prev = to = de;
1131         while ((char*)de < base + blocksize) {
1132                 next = ext4_next_entry(de, blocksize);
1133                 if (de->inode && de->name_len) {
1134                         rec_len = EXT4_DIR_REC_LEN(de->name_len);
1135                         if (de > to)
1136                                 memmove(to, de, rec_len);
1137                         to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
1138                         prev = to;
1139                         to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
1140                 }
1141                 de = next;
1142         }
1143         return prev;
1144 }
1145
1146 /*
1147  * Split a full leaf block to make room for a new dir entry.
1148  * Allocate a new block, and move entries so that they are approx. equally full.
1149  * Returns pointer to de in block into which the new entry will be inserted.
1150  */
1151 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
1152                         struct buffer_head **bh,struct dx_frame *frame,
1153                         struct dx_hash_info *hinfo, int *error)
1154 {
1155         unsigned blocksize = dir->i_sb->s_blocksize;
1156         unsigned count, continued;
1157         struct buffer_head *bh2;
1158         ext4_lblk_t newblock;
1159         u32 hash2;
1160         struct dx_map_entry *map;
1161         char *data1 = (*bh)->b_data, *data2;
1162         unsigned split, move, size;
1163         struct ext4_dir_entry_2 *de = NULL, *de2;
1164         int     err = 0, i;
1165
1166         bh2 = ext4_append (handle, dir, &newblock, &err);
1167         if (!(bh2)) {
1168                 brelse(*bh);
1169                 *bh = NULL;
1170                 goto errout;
1171         }
1172
1173         BUFFER_TRACE(*bh, "get_write_access");
1174         err = ext4_journal_get_write_access(handle, *bh);
1175         if (err)
1176                 goto journal_error;
1177
1178         BUFFER_TRACE(frame->bh, "get_write_access");
1179         err = ext4_journal_get_write_access(handle, frame->bh);
1180         if (err)
1181                 goto journal_error;
1182
1183         data2 = bh2->b_data;
1184
1185         /* create map in the end of data2 block */
1186         map = (struct dx_map_entry *) (data2 + blocksize);
1187         count = dx_make_map((struct ext4_dir_entry_2 *) data1,
1188                              blocksize, hinfo, map);
1189         map -= count;
1190         dx_sort_map(map, count);
1191         /* Split the existing block in the middle, size-wise */
1192         size = 0;
1193         move = 0;
1194         for (i = count-1; i >= 0; i--) {
1195                 /* is more than half of this entry in 2nd half of the block? */
1196                 if (size + map[i].size/2 > blocksize/2)
1197                         break;
1198                 size += map[i].size;
1199                 move++;
1200         }
1201         /* map index at which we will split */
1202         split = count - move;
1203         hash2 = map[split].hash;
1204         continued = hash2 == map[split - 1].hash;
1205         dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
1206                         (unsigned long)dx_get_block(frame->at),
1207                                         hash2, split, count-split));
1208
1209         /* Fancy dance to stay within two buffers */
1210         de2 = dx_move_dirents(data1, data2, map + split, count - split, blocksize);
1211         de = dx_pack_dirents(data1, blocksize);
1212         de->rec_len = ext4_rec_len_to_disk(data1 + blocksize - (char *) de,
1213                                            blocksize);
1214         de2->rec_len = ext4_rec_len_to_disk(data2 + blocksize - (char *) de2,
1215                                             blocksize);
1216         dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data1, blocksize, 1));
1217         dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data2, blocksize, 1));
1218
1219         /* Which block gets the new entry? */
1220         if (hinfo->hash >= hash2)
1221         {
1222                 swap(*bh, bh2);
1223                 de = de2;
1224         }
1225         dx_insert_block(frame, hash2 + continued, newblock);
1226         err = ext4_handle_dirty_metadata(handle, dir, bh2);
1227         if (err)
1228                 goto journal_error;
1229         err = ext4_handle_dirty_metadata(handle, dir, frame->bh);
1230         if (err)
1231                 goto journal_error;
1232         brelse(bh2);
1233         dxtrace(dx_show_index("frame", frame->entries));
1234         return de;
1235
1236 journal_error:
1237         brelse(*bh);
1238         brelse(bh2);
1239         *bh = NULL;
1240         ext4_std_error(dir->i_sb, err);
1241 errout:
1242         *error = err;
1243         return NULL;
1244 }
1245
1246 /*
1247  * Add a new entry into a directory (leaf) block.  If de is non-NULL,
1248  * it points to a directory entry which is guaranteed to be large
1249  * enough for new directory entry.  If de is NULL, then
1250  * add_dirent_to_buf will attempt search the directory block for
1251  * space.  It will return -ENOSPC if no space is available, and -EIO
1252  * and -EEXIST if directory entry already exists.
1253  */
1254 static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
1255                              struct inode *inode, struct ext4_dir_entry_2 *de,
1256                              struct buffer_head *bh)
1257 {
1258         struct inode    *dir = dentry->d_parent->d_inode;
1259         const char      *name = dentry->d_name.name;
1260         int             namelen = dentry->d_name.len;
1261         unsigned int    offset = 0;
1262         unsigned int    blocksize = dir->i_sb->s_blocksize;
1263         unsigned short  reclen;
1264         int             nlen, rlen, err;
1265         char            *top;
1266
1267         reclen = EXT4_DIR_REC_LEN(namelen);
1268         if (!de) {
1269                 de = (struct ext4_dir_entry_2 *)bh->b_data;
1270                 top = bh->b_data + blocksize - reclen;
1271                 while ((char *) de <= top) {
1272                         if (ext4_check_dir_entry(dir, NULL, de, bh, offset))
1273                                 return -EIO;
1274                         if (ext4_match(namelen, name, de))
1275                                 return -EEXIST;
1276                         nlen = EXT4_DIR_REC_LEN(de->name_len);
1277                         rlen = ext4_rec_len_from_disk(de->rec_len, blocksize);
1278                         if ((de->inode? rlen - nlen: rlen) >= reclen)
1279                                 break;
1280                         de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
1281                         offset += rlen;
1282                 }
1283                 if ((char *) de > top)
1284                         return -ENOSPC;
1285         }
1286         BUFFER_TRACE(bh, "get_write_access");
1287         err = ext4_journal_get_write_access(handle, bh);
1288         if (err) {
1289                 ext4_std_error(dir->i_sb, err);
1290                 return err;
1291         }
1292
1293         /* By now the buffer is marked for journaling */
1294         nlen = EXT4_DIR_REC_LEN(de->name_len);
1295         rlen = ext4_rec_len_from_disk(de->rec_len, blocksize);
1296         if (de->inode) {
1297                 struct ext4_dir_entry_2 *de1 = (struct ext4_dir_entry_2 *)((char *)de + nlen);
1298                 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, blocksize);
1299                 de->rec_len = ext4_rec_len_to_disk(nlen, blocksize);
1300                 de = de1;
1301         }
1302         de->file_type = EXT4_FT_UNKNOWN;
1303         if (inode) {
1304                 de->inode = cpu_to_le32(inode->i_ino);
1305                 ext4_set_de_type(dir->i_sb, de, inode->i_mode);
1306         } else
1307                 de->inode = 0;
1308         de->name_len = namelen;
1309         memcpy(de->name, name, namelen);
1310         /*
1311          * XXX shouldn't update any times until successful
1312          * completion of syscall, but too many callers depend
1313          * on this.
1314          *
1315          * XXX similarly, too many callers depend on
1316          * ext4_new_inode() setting the times, but error
1317          * recovery deletes the inode, so the worst that can
1318          * happen is that the times are slightly out of date
1319          * and/or different from the directory change time.
1320          */
1321         dir->i_mtime = dir->i_ctime = ext4_current_time(dir);
1322         ext4_update_dx_flag(dir);
1323         dir->i_version++;
1324         ext4_mark_inode_dirty(handle, dir);
1325         BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1326         err = ext4_handle_dirty_metadata(handle, dir, bh);
1327         if (err)
1328                 ext4_std_error(dir->i_sb, err);
1329         return 0;
1330 }
1331
1332 /*
1333  * This converts a one block unindexed directory to a 3 block indexed
1334  * directory, and adds the dentry to the indexed directory.
1335  */
1336 static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
1337                             struct inode *inode, struct buffer_head *bh)
1338 {
1339         struct inode    *dir = dentry->d_parent->d_inode;
1340         const char      *name = dentry->d_name.name;
1341         int             namelen = dentry->d_name.len;
1342         struct buffer_head *bh2;
1343         struct dx_root  *root;
1344         struct dx_frame frames[2], *frame;
1345         struct dx_entry *entries;
1346         struct ext4_dir_entry_2 *de, *de2;
1347         char            *data1, *top;
1348         unsigned        len;
1349         int             retval;
1350         unsigned        blocksize;
1351         struct dx_hash_info hinfo;
1352         ext4_lblk_t  block;
1353         struct fake_dirent *fde;
1354
1355         blocksize =  dir->i_sb->s_blocksize;
1356         dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
1357         retval = ext4_journal_get_write_access(handle, bh);
1358         if (retval) {
1359                 ext4_std_error(dir->i_sb, retval);
1360                 brelse(bh);
1361                 return retval;
1362         }
1363         root = (struct dx_root *) bh->b_data;
1364
1365         /* The 0th block becomes the root, move the dirents out */
1366         fde = &root->dotdot;
1367         de = (struct ext4_dir_entry_2 *)((char *)fde +
1368                 ext4_rec_len_from_disk(fde->rec_len, blocksize));
1369         if ((char *) de >= (((char *) root) + blocksize)) {
1370                 EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
1371                 brelse(bh);
1372                 return -EIO;
1373         }
1374         len = ((char *) root) + blocksize - (char *) de;
1375
1376         /* Allocate new block for the 0th block's dirents */
1377         bh2 = ext4_append(handle, dir, &block, &retval);
1378         if (!(bh2)) {
1379                 brelse(bh);
1380                 return retval;
1381         }
1382         ext4_set_inode_flag(dir, EXT4_INODE_INDEX);
1383         data1 = bh2->b_data;
1384
1385         memcpy (data1, de, len);
1386         de = (struct ext4_dir_entry_2 *) data1;
1387         top = data1 + len;
1388         while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
1389                 de = de2;
1390         de->rec_len = ext4_rec_len_to_disk(data1 + blocksize - (char *) de,
1391                                            blocksize);
1392         /* Initialize the root; the dot dirents already exist */
1393         de = (struct ext4_dir_entry_2 *) (&root->dotdot);
1394         de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
1395                                            blocksize);
1396         memset (&root->info, 0, sizeof(root->info));
1397         root->info.info_length = sizeof(root->info);
1398         root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
1399         entries = root->entries;
1400         dx_set_block(entries, 1);
1401         dx_set_count(entries, 1);
1402         dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
1403
1404         /* Initialize as for dx_probe */
1405         hinfo.hash_version = root->info.hash_version;
1406         if (hinfo.hash_version <= DX_HASH_TEA)
1407                 hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
1408         hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
1409         ext4fs_dirhash(name, namelen, &hinfo);
1410         frame = frames;
1411         frame->entries = entries;
1412         frame->at = entries;
1413         frame->bh = bh;
1414         bh = bh2;
1415         de = do_split(handle,dir, &bh, frame, &hinfo, &retval);
1416         dx_release (frames);
1417         if (!(de))
1418                 return retval;
1419
1420         retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
1421         brelse(bh);
1422         return retval;
1423 }
1424
1425 /*
1426  *      ext4_add_entry()
1427  *
1428  * adds a file entry to the specified directory, using the same
1429  * semantics as ext4_find_entry(). It returns NULL if it failed.
1430  *
1431  * NOTE!! The inode part of 'de' is left at 0 - which means you
1432  * may not sleep between calling this and putting something into
1433  * the entry, as someone else might have used it while you slept.
1434  */
1435 static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
1436                           struct inode *inode)
1437 {
1438         struct inode *dir = dentry->d_parent->d_inode;
1439         struct buffer_head *bh;
1440         struct ext4_dir_entry_2 *de;
1441         struct super_block *sb;
1442         int     retval;
1443         int     dx_fallback=0;
1444         unsigned blocksize;
1445         ext4_lblk_t block, blocks;
1446
1447         sb = dir->i_sb;
1448         blocksize = sb->s_blocksize;
1449         if (!dentry->d_name.len)
1450                 return -EINVAL;
1451         if (is_dx(dir)) {
1452                 retval = ext4_dx_add_entry(handle, dentry, inode);
1453                 if (!retval || (retval != ERR_BAD_DX_DIR))
1454                         return retval;
1455                 ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
1456                 dx_fallback++;
1457                 ext4_mark_inode_dirty(handle, dir);
1458         }
1459         blocks = dir->i_size >> sb->s_blocksize_bits;
1460         for (block = 0; block < blocks; block++) {
1461                 bh = ext4_bread(handle, dir, block, 0, &retval);
1462                 if(!bh)
1463                         return retval;
1464                 retval = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
1465                 if (retval != -ENOSPC) {
1466                         brelse(bh);
1467                         return retval;
1468                 }
1469
1470                 if (blocks == 1 && !dx_fallback &&
1471                     EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX))
1472                         return make_indexed_dir(handle, dentry, inode, bh);
1473                 brelse(bh);
1474         }
1475         bh = ext4_append(handle, dir, &block, &retval);
1476         if (!bh)
1477                 return retval;
1478         de = (struct ext4_dir_entry_2 *) bh->b_data;
1479         de->inode = 0;
1480         de->rec_len = ext4_rec_len_to_disk(blocksize, blocksize);
1481         retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
1482         brelse(bh);
1483         if (retval == 0)
1484                 ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY);
1485         return retval;
1486 }
1487
1488 /*
1489  * Returns 0 for success, or a negative error value
1490  */
1491 static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
1492                              struct inode *inode)
1493 {
1494         struct dx_frame frames[2], *frame;
1495         struct dx_entry *entries, *at;
1496         struct dx_hash_info hinfo;
1497         struct buffer_head *bh;
1498         struct inode *dir = dentry->d_parent->d_inode;
1499         struct super_block *sb = dir->i_sb;
1500         struct ext4_dir_entry_2 *de;
1501         int err;
1502
1503         frame = dx_probe(&dentry->d_name, dir, &hinfo, frames, &err);
1504         if (!frame)
1505                 return err;
1506         entries = frame->entries;
1507         at = frame->at;
1508
1509         if (!(bh = ext4_bread(handle,dir, dx_get_block(frame->at), 0, &err)))
1510                 goto cleanup;
1511
1512         BUFFER_TRACE(bh, "get_write_access");
1513         err = ext4_journal_get_write_access(handle, bh);
1514         if (err)
1515                 goto journal_error;
1516
1517         err = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
1518         if (err != -ENOSPC)
1519                 goto cleanup;
1520
1521         /* Block full, should compress but for now just split */
1522         dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
1523                        dx_get_count(entries), dx_get_limit(entries)));
1524         /* Need to split index? */
1525         if (dx_get_count(entries) == dx_get_limit(entries)) {
1526                 ext4_lblk_t newblock;
1527                 unsigned icount = dx_get_count(entries);
1528                 int levels = frame - frames;
1529                 struct dx_entry *entries2;
1530                 struct dx_node *node2;
1531                 struct buffer_head *bh2;
1532
1533                 if (levels && (dx_get_count(frames->entries) ==
1534                                dx_get_limit(frames->entries))) {
1535                         ext4_warning(sb, "Directory index full!");
1536                         err = -ENOSPC;
1537                         goto cleanup;
1538                 }
1539                 bh2 = ext4_append (handle, dir, &newblock, &err);
1540                 if (!(bh2))
1541                         goto cleanup;
1542                 node2 = (struct dx_node *)(bh2->b_data);
1543                 entries2 = node2->entries;
1544                 memset(&node2->fake, 0, sizeof(struct fake_dirent));
1545                 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
1546                                                            sb->s_blocksize);
1547                 BUFFER_TRACE(frame->bh, "get_write_access");
1548                 err = ext4_journal_get_write_access(handle, frame->bh);
1549                 if (err)
1550                         goto journal_error;
1551                 if (levels) {
1552                         unsigned icount1 = icount/2, icount2 = icount - icount1;
1553                         unsigned hash2 = dx_get_hash(entries + icount1);
1554                         dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
1555                                        icount1, icount2));
1556
1557                         BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
1558                         err = ext4_journal_get_write_access(handle,
1559                                                              frames[0].bh);
1560                         if (err)
1561                                 goto journal_error;
1562
1563                         memcpy((char *) entries2, (char *) (entries + icount1),
1564                                icount2 * sizeof(struct dx_entry));
1565                         dx_set_count(entries, icount1);
1566                         dx_set_count(entries2, icount2);
1567                         dx_set_limit(entries2, dx_node_limit(dir));
1568
1569                         /* Which index block gets the new entry? */
1570                         if (at - entries >= icount1) {
1571                                 frame->at = at = at - entries - icount1 + entries2;
1572                                 frame->entries = entries = entries2;
1573                                 swap(frame->bh, bh2);
1574                         }
1575                         dx_insert_block(frames + 0, hash2, newblock);
1576                         dxtrace(dx_show_index("node", frames[1].entries));
1577                         dxtrace(dx_show_index("node",
1578                                ((struct dx_node *) bh2->b_data)->entries));
1579                         err = ext4_handle_dirty_metadata(handle, inode, bh2);
1580                         if (err)
1581                                 goto journal_error;
1582                         brelse (bh2);
1583                 } else {
1584                         dxtrace(printk(KERN_DEBUG
1585                                        "Creating second level index...\n"));
1586                         memcpy((char *) entries2, (char *) entries,
1587                                icount * sizeof(struct dx_entry));
1588                         dx_set_limit(entries2, dx_node_limit(dir));
1589
1590                         /* Set up root */
1591                         dx_set_count(entries, 1);
1592                         dx_set_block(entries + 0, newblock);
1593                         ((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels = 1;
1594
1595                         /* Add new access path frame */
1596                         frame = frames + 1;
1597                         frame->at = at = at - entries + entries2;
1598                         frame->entries = entries = entries2;
1599                         frame->bh = bh2;
1600                         err = ext4_journal_get_write_access(handle,
1601                                                              frame->bh);
1602                         if (err)
1603                                 goto journal_error;
1604                 }
1605                 err = ext4_handle_dirty_metadata(handle, inode, frames[0].bh);
1606                 if (err) {
1607                         ext4_std_error(inode->i_sb, err);
1608                         goto cleanup;
1609                 }
1610         }
1611         de = do_split(handle, dir, &bh, frame, &hinfo, &err);
1612         if (!de)
1613                 goto cleanup;
1614         err = add_dirent_to_buf(handle, dentry, inode, de, bh);
1615         goto cleanup;
1616
1617 journal_error:
1618         ext4_std_error(dir->i_sb, err);
1619 cleanup:
1620         if (bh)
1621                 brelse(bh);
1622         dx_release(frames);
1623         return err;
1624 }
1625
1626 /*
1627  * ext4_delete_entry deletes a directory entry by merging it with the
1628  * previous entry
1629  */
1630 static int ext4_delete_entry(handle_t *handle,
1631                              struct inode *dir,
1632                              struct ext4_dir_entry_2 *de_del,
1633                              struct buffer_head *bh)
1634 {
1635         struct ext4_dir_entry_2 *de, *pde;
1636         unsigned int blocksize = dir->i_sb->s_blocksize;
1637         int i, err;
1638
1639         i = 0;
1640         pde = NULL;
1641         de = (struct ext4_dir_entry_2 *) bh->b_data;
1642         while (i < bh->b_size) {
1643                 if (ext4_check_dir_entry(dir, NULL, de, bh, i))
1644                         return -EIO;
1645                 if (de == de_del)  {
1646                         BUFFER_TRACE(bh, "get_write_access");
1647                         err = ext4_journal_get_write_access(handle, bh);
1648                         if (unlikely(err)) {
1649                                 ext4_std_error(dir->i_sb, err);
1650                                 return err;
1651                         }
1652                         if (pde)
1653                                 pde->rec_len = ext4_rec_len_to_disk(
1654                                         ext4_rec_len_from_disk(pde->rec_len,
1655                                                                blocksize) +
1656                                         ext4_rec_len_from_disk(de->rec_len,
1657                                                                blocksize),
1658                                         blocksize);
1659                         else
1660                                 de->inode = 0;
1661                         dir->i_version++;
1662                         BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1663                         err = ext4_handle_dirty_metadata(handle, dir, bh);
1664                         if (unlikely(err)) {
1665                                 ext4_std_error(dir->i_sb, err);
1666                                 return err;
1667                         }
1668                         return 0;
1669                 }
1670                 i += ext4_rec_len_from_disk(de->rec_len, blocksize);
1671                 pde = de;
1672                 de = ext4_next_entry(de, blocksize);
1673         }
1674         return -ENOENT;
1675 }
1676
1677 /*
1678  * DIR_NLINK feature is set if 1) nlinks > EXT4_LINK_MAX or 2) nlinks == 2,
1679  * since this indicates that nlinks count was previously 1.
1680  */
1681 static void ext4_inc_count(handle_t *handle, struct inode *inode)
1682 {
1683         inc_nlink(inode);
1684         if (is_dx(inode) && inode->i_nlink > 1) {
1685                 /* limit is 16-bit i_links_count */
1686                 if (inode->i_nlink >= EXT4_LINK_MAX || inode->i_nlink == 2) {
1687                         inode->i_nlink = 1;
1688                         EXT4_SET_RO_COMPAT_FEATURE(inode->i_sb,
1689                                               EXT4_FEATURE_RO_COMPAT_DIR_NLINK);
1690                 }
1691         }
1692 }
1693
1694 /*
1695  * If a directory had nlink == 1, then we should let it be 1. This indicates
1696  * directory has >EXT4_LINK_MAX subdirs.
1697  */
1698 static void ext4_dec_count(handle_t *handle, struct inode *inode)
1699 {
1700         drop_nlink(inode);
1701         if (S_ISDIR(inode->i_mode) && inode->i_nlink == 0)
1702                 inc_nlink(inode);
1703 }
1704
1705
1706 static int ext4_add_nondir(handle_t *handle,
1707                 struct dentry *dentry, struct inode *inode)
1708 {
1709         int err = ext4_add_entry(handle, dentry, inode);
1710         if (!err) {
1711                 ext4_mark_inode_dirty(handle, inode);
1712                 d_instantiate(dentry, inode);
1713                 unlock_new_inode(inode);
1714                 return 0;
1715         }
1716         drop_nlink(inode);
1717         unlock_new_inode(inode);
1718         iput(inode);
1719         return err;
1720 }
1721
1722 /*
1723  * By the time this is called, we already have created
1724  * the directory cache entry for the new file, but it
1725  * is so far negative - it has no inode.
1726  *
1727  * If the create succeeds, we fill in the inode information
1728  * with d_instantiate().
1729  */
1730 static int ext4_create(struct inode *dir, struct dentry *dentry, int mode,
1731                        struct nameidata *nd)
1732 {
1733         handle_t *handle;
1734         struct inode *inode;
1735         int err, retries = 0;
1736
1737         dquot_initialize(dir);
1738
1739 retry:
1740         handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
1741                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
1742                                         EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
1743         if (IS_ERR(handle))
1744                 return PTR_ERR(handle);
1745
1746         if (IS_DIRSYNC(dir))
1747                 ext4_handle_sync(handle);
1748
1749         inode = ext4_new_inode(handle, dir, mode, &dentry->d_name, 0);
1750         err = PTR_ERR(inode);
1751         if (!IS_ERR(inode)) {
1752                 inode->i_op = &ext4_file_inode_operations;
1753                 inode->i_fop = &ext4_file_operations;
1754                 ext4_set_aops(inode);
1755                 err = ext4_add_nondir(handle, dentry, inode);
1756         }
1757         ext4_journal_stop(handle);
1758         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
1759                 goto retry;
1760         return err;
1761 }
1762
1763 static int ext4_mknod(struct inode *dir, struct dentry *dentry,
1764                       int mode, dev_t rdev)
1765 {
1766         handle_t *handle;
1767         struct inode *inode;
1768         int err, retries = 0;
1769
1770         if (!new_valid_dev(rdev))
1771                 return -EINVAL;
1772
1773         dquot_initialize(dir);
1774
1775 retry:
1776         handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
1777                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
1778                                         EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
1779         if (IS_ERR(handle))
1780                 return PTR_ERR(handle);
1781
1782         if (IS_DIRSYNC(dir))
1783                 ext4_handle_sync(handle);
1784
1785         inode = ext4_new_inode(handle, dir, mode, &dentry->d_name, 0);
1786         err = PTR_ERR(inode);
1787         if (!IS_ERR(inode)) {
1788                 init_special_inode(inode, inode->i_mode, rdev);
1789 #ifdef CONFIG_EXT4_FS_XATTR
1790                 inode->i_op = &ext4_special_inode_operations;
1791 #endif
1792                 err = ext4_add_nondir(handle, dentry, inode);
1793         }
1794         ext4_journal_stop(handle);
1795         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
1796                 goto retry;
1797         return err;
1798 }
1799
1800 static int ext4_mkdir(struct inode *dir, struct dentry *dentry, int mode)
1801 {
1802         handle_t *handle;
1803         struct inode *inode;
1804         struct buffer_head *dir_block = NULL;
1805         struct ext4_dir_entry_2 *de;
1806         unsigned int blocksize = dir->i_sb->s_blocksize;
1807         int err, retries = 0;
1808
1809         if (EXT4_DIR_LINK_MAX(dir))
1810                 return -EMLINK;
1811
1812         dquot_initialize(dir);
1813
1814 retry:
1815         handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
1816                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
1817                                         EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
1818         if (IS_ERR(handle))
1819                 return PTR_ERR(handle);
1820
1821         if (IS_DIRSYNC(dir))
1822                 ext4_handle_sync(handle);
1823
1824         inode = ext4_new_inode(handle, dir, S_IFDIR | mode,
1825                                &dentry->d_name, 0);
1826         err = PTR_ERR(inode);
1827         if (IS_ERR(inode))
1828                 goto out_stop;
1829
1830         inode->i_op = &ext4_dir_inode_operations;
1831         inode->i_fop = &ext4_dir_operations;
1832         inode->i_size = EXT4_I(inode)->i_disksize = inode->i_sb->s_blocksize;
1833         dir_block = ext4_bread(handle, inode, 0, 1, &err);
1834         if (!dir_block)
1835                 goto out_clear_inode;
1836         BUFFER_TRACE(dir_block, "get_write_access");
1837         err = ext4_journal_get_write_access(handle, dir_block);
1838         if (err)
1839                 goto out_clear_inode;
1840         de = (struct ext4_dir_entry_2 *) dir_block->b_data;
1841         de->inode = cpu_to_le32(inode->i_ino);
1842         de->name_len = 1;
1843         de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
1844                                            blocksize);
1845         strcpy(de->name, ".");
1846         ext4_set_de_type(dir->i_sb, de, S_IFDIR);
1847         de = ext4_next_entry(de, blocksize);
1848         de->inode = cpu_to_le32(dir->i_ino);
1849         de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(1),
1850                                            blocksize);
1851         de->name_len = 2;
1852         strcpy(de->name, "..");
1853         ext4_set_de_type(dir->i_sb, de, S_IFDIR);
1854         inode->i_nlink = 2;
1855         BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
1856         err = ext4_handle_dirty_metadata(handle, dir, dir_block);
1857         if (err)
1858                 goto out_clear_inode;
1859         err = ext4_mark_inode_dirty(handle, inode);
1860         if (!err)
1861                 err = ext4_add_entry(handle, dentry, inode);
1862         if (err) {
1863 out_clear_inode:
1864                 clear_nlink(inode);
1865                 unlock_new_inode(inode);
1866                 ext4_mark_inode_dirty(handle, inode);
1867                 iput(inode);
1868                 goto out_stop;
1869         }
1870         ext4_inc_count(handle, dir);
1871         ext4_update_dx_flag(dir);
1872         err = ext4_mark_inode_dirty(handle, dir);
1873         if (err)
1874                 goto out_clear_inode;
1875         d_instantiate(dentry, inode);
1876         unlock_new_inode(inode);
1877 out_stop:
1878         brelse(dir_block);
1879         ext4_journal_stop(handle);
1880         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
1881                 goto retry;
1882         return err;
1883 }
1884
1885 /*
1886  * routine to check that the specified directory is empty (for rmdir)
1887  */
1888 static int empty_dir(struct inode *inode)
1889 {
1890         unsigned int offset;
1891         struct buffer_head *bh;
1892         struct ext4_dir_entry_2 *de, *de1;
1893         struct super_block *sb;
1894         int err = 0;
1895
1896         sb = inode->i_sb;
1897         if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2) ||
1898             !(bh = ext4_bread(NULL, inode, 0, 0, &err))) {
1899                 if (err)
1900                         EXT4_ERROR_INODE(inode,
1901                                 "error %d reading directory lblock 0", err);
1902                 else
1903                         ext4_warning(inode->i_sb,
1904                                      "bad directory (dir #%lu) - no data block",
1905                                      inode->i_ino);
1906                 return 1;
1907         }
1908         de = (struct ext4_dir_entry_2 *) bh->b_data;
1909         de1 = ext4_next_entry(de, sb->s_blocksize);
1910         if (le32_to_cpu(de->inode) != inode->i_ino ||
1911                         !le32_to_cpu(de1->inode) ||
1912                         strcmp(".", de->name) ||
1913                         strcmp("..", de1->name)) {
1914                 ext4_warning(inode->i_sb,
1915                              "bad directory (dir #%lu) - no `.' or `..'",
1916                              inode->i_ino);
1917                 brelse(bh);
1918                 return 1;
1919         }
1920         offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) +
1921                  ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize);
1922         de = ext4_next_entry(de1, sb->s_blocksize);
1923         while (offset < inode->i_size) {
1924                 if (!bh ||
1925                     (void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
1926                         unsigned int lblock;
1927                         err = 0;
1928                         brelse(bh);
1929                         lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb);
1930                         bh = ext4_bread(NULL, inode, lblock, 0, &err);
1931                         if (!bh) {
1932                                 if (err)
1933                                         EXT4_ERROR_INODE(inode,
1934                                                 "error %d reading directory "
1935                                                 "lblock %u", err, lblock);
1936                                 offset += sb->s_blocksize;
1937                                 continue;
1938                         }
1939                         de = (struct ext4_dir_entry_2 *) bh->b_data;
1940                 }
1941                 if (ext4_check_dir_entry(inode, NULL, de, bh, offset)) {
1942                         de = (struct ext4_dir_entry_2 *)(bh->b_data +
1943                                                          sb->s_blocksize);
1944                         offset = (offset | (sb->s_blocksize - 1)) + 1;
1945                         continue;
1946                 }
1947                 if (le32_to_cpu(de->inode)) {
1948                         brelse(bh);
1949                         return 0;
1950                 }
1951                 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
1952                 de = ext4_next_entry(de, sb->s_blocksize);
1953         }
1954         brelse(bh);
1955         return 1;
1956 }
1957
1958 /* ext4_orphan_add() links an unlinked or truncated inode into a list of
1959  * such inodes, starting at the superblock, in case we crash before the
1960  * file is closed/deleted, or in case the inode truncate spans multiple
1961  * transactions and the last transaction is not recovered after a crash.
1962  *
1963  * At filesystem recovery time, we walk this list deleting unlinked
1964  * inodes and truncating linked inodes in ext4_orphan_cleanup().
1965  */
1966 int ext4_orphan_add(handle_t *handle, struct inode *inode)
1967 {
1968         struct super_block *sb = inode->i_sb;
1969         struct ext4_iloc iloc;
1970         int err = 0, rc;
1971
1972         if (!ext4_handle_valid(handle))
1973                 return 0;
1974
1975         mutex_lock(&EXT4_SB(sb)->s_orphan_lock);
1976         if (!list_empty(&EXT4_I(inode)->i_orphan))
1977                 goto out_unlock;
1978
1979         /* Orphan handling is only valid for files with data blocks
1980          * being truncated, or files being unlinked. */
1981
1982         /* @@@ FIXME: Observation from aviro:
1983          * I think I can trigger J_ASSERT in ext4_orphan_add().  We block
1984          * here (on s_orphan_lock), so race with ext4_link() which might bump
1985          * ->i_nlink. For, say it, character device. Not a regular file,
1986          * not a directory, not a symlink and ->i_nlink > 0.
1987          *
1988          * tytso, 4/25/2009: I'm not sure how that could happen;
1989          * shouldn't the fs core protect us from these sort of
1990          * unlink()/link() races?
1991          */
1992         J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
1993                   S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
1994
1995         BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access");
1996         err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
1997         if (err)
1998                 goto out_unlock;
1999
2000         err = ext4_reserve_inode_write(handle, inode, &iloc);
2001         if (err)
2002                 goto out_unlock;
2003         /*
2004          * Due to previous errors inode may be already a part of on-disk
2005          * orphan list. If so skip on-disk list modification.
2006          */
2007         if (NEXT_ORPHAN(inode) && NEXT_ORPHAN(inode) <=
2008                 (le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count)))
2009                         goto mem_insert;
2010
2011         /* Insert this inode at the head of the on-disk orphan list... */
2012         NEXT_ORPHAN(inode) = le32_to_cpu(EXT4_SB(sb)->s_es->s_last_orphan);
2013         EXT4_SB(sb)->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
2014         err = ext4_handle_dirty_metadata(handle, NULL, EXT4_SB(sb)->s_sbh);
2015         rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
2016         if (!err)
2017                 err = rc;
2018
2019         /* Only add to the head of the in-memory list if all the
2020          * previous operations succeeded.  If the orphan_add is going to
2021          * fail (possibly taking the journal offline), we can't risk
2022          * leaving the inode on the orphan list: stray orphan-list
2023          * entries can cause panics at unmount time.
2024          *
2025          * This is safe: on error we're going to ignore the orphan list
2026          * anyway on the next recovery. */
2027 mem_insert:
2028         if (!err)
2029                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2030
2031         jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
2032         jbd_debug(4, "orphan inode %lu will point to %d\n",
2033                         inode->i_ino, NEXT_ORPHAN(inode));
2034 out_unlock:
2035         mutex_unlock(&EXT4_SB(sb)->s_orphan_lock);
2036         ext4_std_error(inode->i_sb, err);
2037         return err;
2038 }
2039
2040 /*
2041  * ext4_orphan_del() removes an unlinked or truncated inode from the list
2042  * of such inodes stored on disk, because it is finally being cleaned up.
2043  */
2044 int ext4_orphan_del(handle_t *handle, struct inode *inode)
2045 {
2046         struct list_head *prev;
2047         struct ext4_inode_info *ei = EXT4_I(inode);
2048         struct ext4_sb_info *sbi;
2049         __u32 ino_next;
2050         struct ext4_iloc iloc;
2051         int err = 0;
2052
2053         /* ext4_handle_valid() assumes a valid handle_t pointer */
2054         if (handle && !ext4_handle_valid(handle))
2055                 return 0;
2056
2057         mutex_lock(&EXT4_SB(inode->i_sb)->s_orphan_lock);
2058         if (list_empty(&ei->i_orphan))
2059                 goto out;
2060
2061         ino_next = NEXT_ORPHAN(inode);
2062         prev = ei->i_orphan.prev;
2063         sbi = EXT4_SB(inode->i_sb);
2064
2065         jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
2066
2067         list_del_init(&ei->i_orphan);
2068
2069         /* If we're on an error path, we may not have a valid
2070          * transaction handle with which to update the orphan list on
2071          * disk, but we still need to remove the inode from the linked
2072          * list in memory. */
2073         if (sbi->s_journal && !handle)
2074                 goto out;
2075
2076         err = ext4_reserve_inode_write(handle, inode, &iloc);
2077         if (err)
2078                 goto out_err;
2079
2080         if (prev == &sbi->s_orphan) {
2081                 jbd_debug(4, "superblock will point to %u\n", ino_next);
2082                 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2083                 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2084                 if (err)
2085                         goto out_brelse;
2086                 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
2087                 err = ext4_handle_dirty_metadata(handle, NULL, sbi->s_sbh);
2088         } else {
2089                 struct ext4_iloc iloc2;
2090                 struct inode *i_prev =
2091                         &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
2092
2093                 jbd_debug(4, "orphan inode %lu will point to %u\n",
2094                           i_prev->i_ino, ino_next);
2095                 err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
2096                 if (err)
2097                         goto out_brelse;
2098                 NEXT_ORPHAN(i_prev) = ino_next;
2099                 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
2100         }
2101         if (err)
2102                 goto out_brelse;
2103         NEXT_ORPHAN(inode) = 0;
2104         err = ext4_mark_iloc_dirty(handle, inode, &iloc);
2105
2106 out_err:
2107         ext4_std_error(inode->i_sb, err);
2108 out:
2109         mutex_unlock(&EXT4_SB(inode->i_sb)->s_orphan_lock);
2110         return err;
2111
2112 out_brelse:
2113         brelse(iloc.bh);
2114         goto out_err;
2115 }
2116
2117 static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
2118 {
2119         int retval;
2120         struct inode *inode;
2121         struct buffer_head *bh;
2122         struct ext4_dir_entry_2 *de;
2123         handle_t *handle;
2124
2125         /* Initialize quotas before so that eventual writes go in
2126          * separate transaction */
2127         dquot_initialize(dir);
2128         dquot_initialize(dentry->d_inode);
2129
2130         handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb));
2131         if (IS_ERR(handle))
2132                 return PTR_ERR(handle);
2133
2134         retval = -ENOENT;
2135         bh = ext4_find_entry(dir, &dentry->d_name, &de);
2136         if (!bh)
2137                 goto end_rmdir;
2138
2139         if (IS_DIRSYNC(dir))
2140                 ext4_handle_sync(handle);
2141
2142         inode = dentry->d_inode;
2143
2144         retval = -EIO;
2145         if (le32_to_cpu(de->inode) != inode->i_ino)
2146                 goto end_rmdir;
2147
2148         retval = -ENOTEMPTY;
2149         if (!empty_dir(inode))
2150                 goto end_rmdir;
2151
2152         retval = ext4_delete_entry(handle, dir, de, bh);
2153         if (retval)
2154                 goto end_rmdir;
2155         if (!EXT4_DIR_LINK_EMPTY(inode))
2156                 ext4_warning(inode->i_sb,
2157                              "empty directory has too many links (%d)",
2158                              inode->i_nlink);
2159         inode->i_version++;
2160         clear_nlink(inode);
2161         /* There's no need to set i_disksize: the fact that i_nlink is
2162          * zero will ensure that the right thing happens during any
2163          * recovery. */
2164         inode->i_size = 0;
2165         ext4_orphan_add(handle, inode);
2166         inode->i_ctime = dir->i_ctime = dir->i_mtime = ext4_current_time(inode);
2167         ext4_mark_inode_dirty(handle, inode);
2168         ext4_dec_count(handle, dir);
2169         ext4_update_dx_flag(dir);
2170         ext4_mark_inode_dirty(handle, dir);
2171
2172 end_rmdir:
2173         ext4_journal_stop(handle);
2174         brelse(bh);
2175         return retval;
2176 }
2177
2178 static int ext4_unlink(struct inode *dir, struct dentry *dentry)
2179 {
2180         int retval;
2181         struct inode *inode;
2182         struct buffer_head *bh;
2183         struct ext4_dir_entry_2 *de;
2184         handle_t *handle;
2185
2186         /* Initialize quotas before so that eventual writes go
2187          * in separate transaction */
2188         dquot_initialize(dir);
2189         dquot_initialize(dentry->d_inode);
2190
2191         handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb));
2192         if (IS_ERR(handle))
2193                 return PTR_ERR(handle);
2194
2195         if (IS_DIRSYNC(dir))
2196                 ext4_handle_sync(handle);
2197
2198         retval = -ENOENT;
2199         bh = ext4_find_entry(dir, &dentry->d_name, &de);
2200         if (!bh)
2201                 goto end_unlink;
2202
2203         inode = dentry->d_inode;
2204
2205         retval = -EIO;
2206         if (le32_to_cpu(de->inode) != inode->i_ino)
2207                 goto end_unlink;
2208
2209         if (!inode->i_nlink) {
2210                 ext4_warning(inode->i_sb,
2211                              "Deleting nonexistent file (%lu), %d",
2212                              inode->i_ino, inode->i_nlink);
2213                 inode->i_nlink = 1;
2214         }
2215         retval = ext4_delete_entry(handle, dir, de, bh);
2216         if (retval)
2217                 goto end_unlink;
2218         dir->i_ctime = dir->i_mtime = ext4_current_time(dir);
2219         ext4_update_dx_flag(dir);
2220         ext4_mark_inode_dirty(handle, dir);
2221         drop_nlink(inode);
2222         if (!inode->i_nlink)
2223                 ext4_orphan_add(handle, inode);
2224         inode->i_ctime = ext4_current_time(inode);
2225         ext4_mark_inode_dirty(handle, inode);
2226         retval = 0;
2227
2228 end_unlink:
2229         ext4_journal_stop(handle);
2230         brelse(bh);
2231         return retval;
2232 }
2233
2234 static int ext4_symlink(struct inode *dir,
2235                         struct dentry *dentry, const char *symname)
2236 {
2237         handle_t *handle;
2238         struct inode *inode;
2239         int l, err, retries = 0;
2240
2241         l = strlen(symname)+1;
2242         if (l > dir->i_sb->s_blocksize)
2243                 return -ENAMETOOLONG;
2244
2245         dquot_initialize(dir);
2246
2247 retry:
2248         handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2249                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS + 5 +
2250                                         EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
2251         if (IS_ERR(handle))
2252                 return PTR_ERR(handle);
2253
2254         if (IS_DIRSYNC(dir))
2255                 ext4_handle_sync(handle);
2256
2257         inode = ext4_new_inode(handle, dir, S_IFLNK|S_IRWXUGO,
2258                                &dentry->d_name, 0);
2259         err = PTR_ERR(inode);
2260         if (IS_ERR(inode))
2261                 goto out_stop;
2262
2263         if (l > sizeof(EXT4_I(inode)->i_data)) {
2264                 inode->i_op = &ext4_symlink_inode_operations;
2265                 ext4_set_aops(inode);
2266                 /*
2267                  * page_symlink() calls into ext4_prepare/commit_write.
2268                  * We have a transaction open.  All is sweetness.  It also sets
2269                  * i_size in generic_commit_write().
2270                  */
2271                 err = __page_symlink(inode, symname, l, 1);
2272                 if (err) {
2273                         clear_nlink(inode);
2274                         unlock_new_inode(inode);
2275                         ext4_mark_inode_dirty(handle, inode);
2276                         iput(inode);
2277                         goto out_stop;
2278                 }
2279         } else {
2280                 /* clear the extent format for fast symlink */
2281                 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
2282                 inode->i_op = &ext4_fast_symlink_inode_operations;
2283                 memcpy((char *)&EXT4_I(inode)->i_data, symname, l);
2284                 inode->i_size = l-1;
2285         }
2286         EXT4_I(inode)->i_disksize = inode->i_size;
2287         err = ext4_add_nondir(handle, dentry, inode);
2288 out_stop:
2289         ext4_journal_stop(handle);
2290         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2291                 goto retry;
2292         return err;
2293 }
2294
2295 static int ext4_link(struct dentry *old_dentry,
2296                      struct inode *dir, struct dentry *dentry)
2297 {
2298         handle_t *handle;
2299         struct inode *inode = old_dentry->d_inode;
2300         int err, retries = 0;
2301
2302         if (inode->i_nlink >= EXT4_LINK_MAX)
2303                 return -EMLINK;
2304
2305         dquot_initialize(dir);
2306
2307         /*
2308          * Return -ENOENT if we've raced with unlink and i_nlink is 0.  Doing
2309          * otherwise has the potential to corrupt the orphan inode list.
2310          */
2311         if (inode->i_nlink == 0)
2312                 return -ENOENT;
2313
2314 retry:
2315         handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2316                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS);
2317         if (IS_ERR(handle))
2318                 return PTR_ERR(handle);
2319
2320         if (IS_DIRSYNC(dir))
2321                 ext4_handle_sync(handle);
2322
2323         inode->i_ctime = ext4_current_time(inode);
2324         ext4_inc_count(handle, inode);
2325         ihold(inode);
2326
2327         err = ext4_add_entry(handle, dentry, inode);
2328         if (!err) {
2329                 ext4_mark_inode_dirty(handle, inode);
2330                 d_instantiate(dentry, inode);
2331         } else {
2332                 drop_nlink(inode);
2333                 iput(inode);
2334         }
2335         ext4_journal_stop(handle);
2336         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2337                 goto retry;
2338         return err;
2339 }
2340
2341 #define PARENT_INO(buffer, size) \
2342         (ext4_next_entry((struct ext4_dir_entry_2 *)(buffer), size)->inode)
2343
2344 /*
2345  * Anybody can rename anything with this: the permission checks are left to the
2346  * higher-level routines.
2347  */
2348 static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
2349                        struct inode *new_dir, struct dentry *new_dentry)
2350 {
2351         handle_t *handle;
2352         struct inode *old_inode, *new_inode;
2353         struct buffer_head *old_bh, *new_bh, *dir_bh;
2354         struct ext4_dir_entry_2 *old_de, *new_de;
2355         int retval, force_da_alloc = 0;
2356
2357         dquot_initialize(old_dir);
2358         dquot_initialize(new_dir);
2359
2360         old_bh = new_bh = dir_bh = NULL;
2361
2362         /* Initialize quotas before so that eventual writes go
2363          * in separate transaction */
2364         if (new_dentry->d_inode)
2365                 dquot_initialize(new_dentry->d_inode);
2366         handle = ext4_journal_start(old_dir, 2 *
2367                                         EXT4_DATA_TRANS_BLOCKS(old_dir->i_sb) +
2368                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
2369         if (IS_ERR(handle))
2370                 return PTR_ERR(handle);
2371
2372         if (IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir))
2373                 ext4_handle_sync(handle);
2374
2375         old_bh = ext4_find_entry(old_dir, &old_dentry->d_name, &old_de);
2376         /*
2377          *  Check for inode number is _not_ due to possible IO errors.
2378          *  We might rmdir the source, keep it as pwd of some process
2379          *  and merrily kill the link to whatever was created under the
2380          *  same name. Goodbye sticky bit ;-<
2381          */
2382         old_inode = old_dentry->d_inode;
2383         retval = -ENOENT;
2384         if (!old_bh || le32_to_cpu(old_de->inode) != old_inode->i_ino)
2385                 goto end_rename;
2386
2387         new_inode = new_dentry->d_inode;
2388         new_bh = ext4_find_entry(new_dir, &new_dentry->d_name, &new_de);
2389         if (new_bh) {
2390                 if (!new_inode) {
2391                         brelse(new_bh);
2392                         new_bh = NULL;
2393                 }
2394         }
2395         if (S_ISDIR(old_inode->i_mode)) {
2396                 if (new_inode) {
2397                         retval = -ENOTEMPTY;
2398                         if (!empty_dir(new_inode))
2399                                 goto end_rename;
2400                 }
2401                 retval = -EIO;
2402                 dir_bh = ext4_bread(handle, old_inode, 0, 0, &retval);
2403                 if (!dir_bh)
2404                         goto end_rename;
2405                 if (le32_to_cpu(PARENT_INO(dir_bh->b_data,
2406                                 old_dir->i_sb->s_blocksize)) != old_dir->i_ino)
2407                         goto end_rename;
2408                 retval = -EMLINK;
2409                 if (!new_inode && new_dir != old_dir &&
2410                     EXT4_DIR_LINK_MAX(new_dir))
2411                         goto end_rename;
2412         }
2413         if (!new_bh) {
2414                 retval = ext4_add_entry(handle, new_dentry, old_inode);
2415                 if (retval)
2416                         goto end_rename;
2417         } else {
2418                 BUFFER_TRACE(new_bh, "get write access");
2419                 ext4_journal_get_write_access(handle, new_bh);
2420                 new_de->inode = cpu_to_le32(old_inode->i_ino);
2421                 if (EXT4_HAS_INCOMPAT_FEATURE(new_dir->i_sb,
2422                                               EXT4_FEATURE_INCOMPAT_FILETYPE))
2423                         new_de->file_type = old_de->file_type;
2424                 new_dir->i_version++;
2425                 new_dir->i_ctime = new_dir->i_mtime =
2426                                         ext4_current_time(new_dir);
2427                 ext4_mark_inode_dirty(handle, new_dir);
2428                 BUFFER_TRACE(new_bh, "call ext4_handle_dirty_metadata");
2429                 retval = ext4_handle_dirty_metadata(handle, new_dir, new_bh);
2430                 if (unlikely(retval)) {
2431                         ext4_std_error(new_dir->i_sb, retval);
2432                         goto end_rename;
2433                 }
2434                 brelse(new_bh);
2435                 new_bh = NULL;
2436         }
2437
2438         /*
2439          * Like most other Unix systems, set the ctime for inodes on a
2440          * rename.
2441          */
2442         old_inode->i_ctime = ext4_current_time(old_inode);
2443         ext4_mark_inode_dirty(handle, old_inode);
2444
2445         /*
2446          * ok, that's it
2447          */
2448         if (le32_to_cpu(old_de->inode) != old_inode->i_ino ||
2449             old_de->name_len != old_dentry->d_name.len ||
2450             strncmp(old_de->name, old_dentry->d_name.name, old_de->name_len) ||
2451             (retval = ext4_delete_entry(handle, old_dir,
2452                                         old_de, old_bh)) == -ENOENT) {
2453                 /* old_de could have moved from under us during htree split, so
2454                  * make sure that we are deleting the right entry.  We might
2455                  * also be pointing to a stale entry in the unused part of
2456                  * old_bh so just checking inum and the name isn't enough. */
2457                 struct buffer_head *old_bh2;
2458                 struct ext4_dir_entry_2 *old_de2;
2459
2460                 old_bh2 = ext4_find_entry(old_dir, &old_dentry->d_name, &old_de2);
2461                 if (old_bh2) {
2462                         retval = ext4_delete_entry(handle, old_dir,
2463                                                    old_de2, old_bh2);
2464                         brelse(old_bh2);
2465                 }
2466         }
2467         if (retval) {
2468                 ext4_warning(old_dir->i_sb,
2469                                 "Deleting old file (%lu), %d, error=%d",
2470                                 old_dir->i_ino, old_dir->i_nlink, retval);
2471         }
2472
2473         if (new_inode) {
2474                 ext4_dec_count(handle, new_inode);
2475                 new_inode->i_ctime = ext4_current_time(new_inode);
2476         }
2477         old_dir->i_ctime = old_dir->i_mtime = ext4_current_time(old_dir);
2478         ext4_update_dx_flag(old_dir);
2479         if (dir_bh) {
2480                 BUFFER_TRACE(dir_bh, "get_write_access");
2481                 ext4_journal_get_write_access(handle, dir_bh);
2482                 PARENT_INO(dir_bh->b_data, new_dir->i_sb->s_blocksize) =
2483                                                 cpu_to_le32(new_dir->i_ino);
2484                 BUFFER_TRACE(dir_bh, "call ext4_handle_dirty_metadata");
2485                 retval = ext4_handle_dirty_metadata(handle, old_dir, dir_bh);
2486                 if (retval) {
2487                         ext4_std_error(old_dir->i_sb, retval);
2488                         goto end_rename;
2489                 }
2490                 ext4_dec_count(handle, old_dir);
2491                 if (new_inode) {
2492                         /* checked empty_dir above, can't have another parent,
2493                          * ext4_dec_count() won't work for many-linked dirs */
2494                         new_inode->i_nlink = 0;
2495                 } else {
2496                         ext4_inc_count(handle, new_dir);
2497                         ext4_update_dx_flag(new_dir);
2498                         ext4_mark_inode_dirty(handle, new_dir);
2499                 }
2500         }
2501         ext4_mark_inode_dirty(handle, old_dir);
2502         if (new_inode) {
2503                 ext4_mark_inode_dirty(handle, new_inode);
2504                 if (!new_inode->i_nlink)
2505                         ext4_orphan_add(handle, new_inode);
2506                 if (!test_opt(new_dir->i_sb, NO_AUTO_DA_ALLOC))
2507                         force_da_alloc = 1;
2508         }
2509         retval = 0;
2510
2511 end_rename:
2512         brelse(dir_bh);
2513         brelse(old_bh);
2514         brelse(new_bh);
2515         ext4_journal_stop(handle);
2516         if (retval == 0 && force_da_alloc)
2517                 ext4_alloc_da_blocks(old_inode);
2518         return retval;
2519 }
2520
2521 /*
2522  * directories can handle most operations...
2523  */
2524 const struct inode_operations ext4_dir_inode_operations = {
2525         .create         = ext4_create,
2526         .lookup         = ext4_lookup,
2527         .link           = ext4_link,
2528         .unlink         = ext4_unlink,
2529         .symlink        = ext4_symlink,
2530         .mkdir          = ext4_mkdir,
2531         .rmdir          = ext4_rmdir,
2532         .mknod          = ext4_mknod,
2533         .rename         = ext4_rename,
2534         .setattr        = ext4_setattr,
2535 #ifdef CONFIG_EXT4_FS_XATTR
2536         .setxattr       = generic_setxattr,
2537         .getxattr       = generic_getxattr,
2538         .listxattr      = ext4_listxattr,
2539         .removexattr    = generic_removexattr,
2540 #endif
2541         .check_acl      = ext4_check_acl,
2542         .fiemap         = ext4_fiemap,
2543 };
2544
2545 const struct inode_operations ext4_special_inode_operations = {
2546         .setattr        = ext4_setattr,
2547 #ifdef CONFIG_EXT4_FS_XATTR
2548         .setxattr       = generic_setxattr,
2549         .getxattr       = generic_getxattr,
2550         .listxattr      = ext4_listxattr,
2551         .removexattr    = generic_removexattr,
2552 #endif
2553         .check_acl      = ext4_check_acl,
2554 };