fs/ext4/namei.c

   1 /*
   2  *  linux/fs/ext4/namei.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Laboratoire MASI - Institut Blaise Pascal
   7  * Universite Pierre et Marie Curie (Paris VI)
   8  *
   9  *  from
  10  *
  11  *  linux/fs/minix/namei.c
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  *
  15  *  Big-endian to little-endian byte-swapping/bitmaps by
  16  *        David S. Miller (davem@caip.rutgers.edu), 1995
  17  *  Directory entry file type support and forward compatibility hooks
  18  *      for B-tree directories by Theodore Ts'o (tytso@mit.edu), 1998
  19  *  Hash Tree Directory indexing (c)
  20  *      Daniel Phillips, 2001
  21  *  Hash Tree Directory indexing porting
  22  *      Christopher Li, 2002
  23  *  Hash Tree Directory indexing cleanup
  24  *      Theodore Ts'o, 2002
  25  */
  26
  27 #include <linux/fs.h>
  28 #include <linux/pagemap.h>
  29 #include <linux/jbd2.h>
  30 #include <linux/time.h>
  31 #include <linux/fcntl.h>
  32 #include <linux/stat.h>
  33 #include <linux/string.h>
  34 #include <linux/quotaops.h>
  35 #include <linux/buffer_head.h>
  36 #include <linux/bio.h>
  37 #include "ext4.h"
  38 #include "ext4_jbd2.h"
  39
  40 #include "namei.h"
  41 #include "xattr.h"
  42 #include "acl.h"
  43
  44 /*
  45  * define how far ahead to read directories while searching them.
  46  */
  47 #define NAMEI_RA_CHUNKS  2
  48 #define NAMEI_RA_BLOCKS  4
  49 #define NAMEI_RA_SIZE        (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS)
  50 #define NAMEI_RA_INDEX(c,b)  (((c) * NAMEI_RA_BLOCKS) + (b))
  51
  52 static struct buffer_head *ext4_append(handle_t *handle,
  53                                         struct inode *inode,
  54                                         ext4_lblk_t *block, int *err)
  55 {
  56         struct buffer_head *bh;
  57
  58         *block = inode->i_size >> inode->i_sb->s_blocksize_bits;
  59
  60         bh = ext4_bread(handle, inode, *block, 1, err);
  61         if (bh) {
  62                 inode->i_size += inode->i_sb->s_blocksize;
  63                 EXT4_I(inode)->i_disksize = inode->i_size;
  64                 *err = ext4_journal_get_write_access(handle, bh);
  65                 if (*err) {
  66                         brelse(bh);
  67                         bh = NULL;
  68                 }
  69         }
  70         return bh;
  71 }
  72
  73 #ifndef assert
  74 #define assert(test) J_ASSERT(test)
  75 #endif
  76
  77 #ifdef DX_DEBUG
  78 #define dxtrace(command) command
  79 #else
  80 #define dxtrace(command)
  81 #endif
  82
  83 struct fake_dirent
  84 {
  85         __le32 inode;
  86         __le16 rec_len;
  87         u8 name_len;
  88         u8 file_type;
  89 };
  90
  91 struct dx_countlimit
  92 {
  93         __le16 limit;
  94         __le16 count;
  95 };
  96
  97 struct dx_entry
  98 {
  99         __le32 hash;
 100         __le32 block;
 101 };
 102
 103 /*
 104  * dx_root_info is laid out so that if it should somehow get overlaid by a
 105  * dirent the two low bits of the hash version will be zero.  Therefore, the
 106  * hash version mod 4 should never be 0.  Sincerely, the paranoia department.
 107  */
 108
 109 struct dx_root
 110 {
 111         struct fake_dirent dot;
 112         char dot_name[4];
 113         struct fake_dirent dotdot;
 114         char dotdot_name[4];
 115         struct dx_root_info
 116         {
 117                 __le32 reserved_zero;
 118                 u8 hash_version;
 119                 u8 info_length; /* 8 */
 120                 u8 indirect_levels;
 121                 u8 unused_flags;
 122         }
 123         info;
 124         struct dx_entry entries[0];
 125 };
 126
 127 struct dx_node
 128 {
 129         struct fake_dirent fake;
 130         struct dx_entry entries[0];
 131 };
 132
 133
 134 struct dx_frame
 135 {
 136         struct buffer_head *bh;
 137         struct dx_entry *entries;
 138         struct dx_entry *at;
 139 };
 140
 141 struct dx_map_entry
 142 {
 143         u32 hash;
 144         u16 offs;
 145         u16 size;
 146 };
 147
 148 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
 149 static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
 150 static inline unsigned dx_get_hash(struct dx_entry *entry);
 151 static void dx_set_hash(struct dx_entry *entry, unsigned value);
 152 static unsigned dx_get_count(struct dx_entry *entries);
 153 static unsigned dx_get_limit(struct dx_entry *entries);
 154 static void dx_set_count(struct dx_entry *entries, unsigned value);
 155 static void dx_set_limit(struct dx_entry *entries, unsigned value);
 156 static unsigned dx_root_limit(struct inode *dir, unsigned infosize);
 157 static unsigned dx_node_limit(struct inode *dir);
 158 static struct dx_frame *dx_probe(const struct qstr *d_name,
 159                                  struct inode *dir,
 160                                  struct dx_hash_info *hinfo,
 161                                  struct dx_frame *frame,
 162                                  int *err);
 163 static void dx_release(struct dx_frame *frames);
 164 static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize,
 165                        struct dx_hash_info *hinfo, struct dx_map_entry map[]);
 166 static void dx_sort_map(struct dx_map_entry *map, unsigned count);
 167 static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to,
 168                 struct dx_map_entry *offsets, int count);
 169 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize);
 170 static void dx_insert_block(struct dx_frame *frame,
 171                                         u32 hash, ext4_lblk_t block);
 172 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
 173                                  struct dx_frame *frame,
 174                                  struct dx_frame *frames,
 175                                  __u32 *start_hash);
 176 static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
 177                 const struct qstr *d_name,
 178                 struct ext4_dir_entry_2 **res_dir,
 179                 int *err);
 180 static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
 181                              struct inode *inode);
 182
 183 /*
 184  * p is at least 6 bytes before the end of page
 185  */
 186 static inline struct ext4_dir_entry_2 *
 187 ext4_next_entry(struct ext4_dir_entry_2 *p)
 188 {
 189         return (struct ext4_dir_entry_2 *)((char *)p +
 190                 ext4_rec_len_from_disk(p->rec_len));
 191 }
 192
 193 /*
 194  * Future: use high four bits of block for coalesce-on-delete flags
 195  * Mask them off for now.
 196  */
 197
 198 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
 199 {
 200         return le32_to_cpu(entry->block) & 0x00ffffff;
 201 }
 202
 203 static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
 204 {
 205         entry->block = cpu_to_le32(value);
 206 }
 207
 208 static inline unsigned dx_get_hash(struct dx_entry *entry)
 209 {
 210         return le32_to_cpu(entry->hash);
 211 }
 212
 213 static inline void dx_set_hash(struct dx_entry *entry, unsigned value)
 214 {
 215         entry->hash = cpu_to_le32(value);
 216 }
 217
 218 static inline unsigned dx_get_count(struct dx_entry *entries)
 219 {
 220         return le16_to_cpu(((struct dx_countlimit *) entries)->count);
 221 }
 222
 223 static inline unsigned dx_get_limit(struct dx_entry *entries)
 224 {
 225         return le16_to_cpu(((struct dx_countlimit *) entries)->limit);
 226 }
 227
 228 static inline void dx_set_count(struct dx_entry *entries, unsigned value)
 229 {
 230         ((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
 231 }
 232
 233 static inline void dx_set_limit(struct dx_entry *entries, unsigned value)
 234 {
 235         ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
 236 }
 237
 238 static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
 239 {
 240         unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
 241                 EXT4_DIR_REC_LEN(2) - infosize;
 242         return entry_space / sizeof(struct dx_entry);
 243 }
 244
 245 static inline unsigned dx_node_limit(struct inode *dir)
 246 {
 247         unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);
 248         return entry_space / sizeof(struct dx_entry);
 249 }
 250
 251 /*
 252  * Debug
 253  */
 254 #ifdef DX_DEBUG
 255 static void dx_show_index(char * label, struct dx_entry *entries)
 256 {
 257         int i, n = dx_get_count (entries);
 258         printk(KERN_DEBUG "%s index ", label);
 259         for (i = 0; i < n; i++) {
 260                 printk("%x->%lu ", i ? dx_get_hash(entries + i) :
 261                                 0, (unsigned long)dx_get_block(entries + i));
 262         }
 263         printk("\n");
 264 }
 265
 266 struct stats
 267 {
 268         unsigned names;
 269         unsigned space;
 270         unsigned bcount;
 271 };
 272
 273 static struct stats dx_show_leaf(struct dx_hash_info *hinfo, struct ext4_dir_entry_2 *de,
 274                                  int size, int show_names)
 275 {
 276         unsigned names = 0, space = 0;
 277         char *base = (char *) de;
 278         struct dx_hash_info h = *hinfo;
 279
 280         printk("names: ");
 281         while ((char *) de < base + size)
 282         {
 283                 if (de->inode)
 284                 {
 285                         if (show_names)
 286                         {
 287                                 int len = de->name_len;
 288                                 char *name = de->name;
 289                                 while (len--) printk("%c", *name++);
 290                                 ext4fs_dirhash(de->name, de->name_len, &h);
 291                                 printk(":%x.%u ", h.hash,
 292                                        ((char *) de - base));
 293                         }
 294                         space += EXT4_DIR_REC_LEN(de->name_len);
 295                         names++;
 296                 }
 297                 de = ext4_next_entry(de);
 298         }
 299         printk("(%i)\n", names);
 300         return (struct stats) { names, space, 1 };
 301 }
 302
 303 struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
 304                              struct dx_entry *entries, int levels)
 305 {
 306         unsigned blocksize = dir->i_sb->s_blocksize;
 307         unsigned count = dx_get_count(entries), names = 0, space = 0, i;
 308         unsigned bcount = 0;
 309         struct buffer_head *bh;
 310         int err;
 311         printk("%i indexed blocks...\n", count);
 312         for (i = 0; i < count; i++, entries++)
 313         {
 314                 ext4_lblk_t block = dx_get_block(entries);
 315                 ext4_lblk_t hash  = i ? dx_get_hash(entries): 0;
 316                 u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
 317                 struct stats stats;
 318                 printk("%s%3u:%03u hash %8x/%8x ",levels?"":"   ", i, block, hash, range);
 319                 if (!(bh = ext4_bread (NULL,dir, block, 0,&err))) continue;
 320                 stats = levels?
 321                    dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
 322                    dx_show_leaf(hinfo, (struct ext4_dir_entry_2 *) bh->b_data, blocksize, 0);
 323                 names += stats.names;
 324                 space += stats.space;
 325                 bcount += stats.bcount;
 326                 brelse(bh);
 327         }
 328         if (bcount)
 329                 printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n",
 330                        levels ? "" : "   ", names, space/bcount,
 331                        (space/bcount)*100/blocksize);
 332         return (struct stats) { names, space, bcount};
 333 }
 334 #endif /* DX_DEBUG */
 335
 336 /*
 337  * Probe for a directory leaf block to search.
 338  *
 339  * dx_probe can return ERR_BAD_DX_DIR, which means there was a format
 340  * error in the directory index, and the caller should fall back to
 341  * searching the directory normally.  The callers of dx_probe **MUST**
 342  * check for this error code, and make sure it never gets reflected
 343  * back to userspace.
 344  */
 345 static struct dx_frame *
 346 dx_probe(const struct qstr *d_name, struct inode *dir,
 347          struct dx_hash_info *hinfo, struct dx_frame *frame_in, int *err)
 348 {
 349         unsigned count, indirect;
 350         struct dx_entry *at, *entries, *p, *q, *m;
 351         struct dx_root *root;
 352         struct buffer_head *bh;
 353         struct dx_frame *frame = frame_in;
 354         u32 hash;
 355
 356         frame->bh = NULL;
 357         if (!(bh = ext4_bread (NULL,dir, 0, 0, err)))
 358                 goto fail;
 359         root = (struct dx_root *) bh->b_data;
 360         if (root->info.hash_version != DX_HASH_TEA &&
 361             root->info.hash_version != DX_HASH_HALF_MD4 &&
 362             root->info.hash_version != DX_HASH_LEGACY) {
 363                 ext4_warning(dir->i_sb, __func__,
 364                              "Unrecognised inode hash code %d",
 365                              root->info.hash_version);
 366                 brelse(bh);
 367                 *err = ERR_BAD_DX_DIR;
 368                 goto fail;
 369         }
 370         hinfo->hash_version = root->info.hash_version;
 371         if (hinfo->hash_version <= DX_HASH_TEA)
 372                 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
 373         hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
 374         if (d_name)
 375                 ext4fs_dirhash(d_name->name, d_name->len, hinfo);
 376         hash = hinfo->hash;
 377
 378         if (root->info.unused_flags & 1) {
 379                 ext4_warning(dir->i_sb, __func__,
 380                              "Unimplemented inode hash flags: %#06x",
 381                              root->info.unused_flags);
 382                 brelse(bh);
 383                 *err = ERR_BAD_DX_DIR;
 384                 goto fail;
 385         }
 386
 387         if ((indirect = root->info.indirect_levels) > 1) {
 388                 ext4_warning(dir->i_sb, __func__,
 389                              "Unimplemented inode hash depth: %#06x",
 390                              root->info.indirect_levels);
 391                 brelse(bh);
 392                 *err = ERR_BAD_DX_DIR;
 393                 goto fail;
 394         }
 395
 396         entries = (struct dx_entry *) (((char *)&root->info) +
 397                                        root->info.info_length);
 398
 399         if (dx_get_limit(entries) != dx_root_limit(dir,
 400                                                    root->info.info_length)) {
 401                 ext4_warning(dir->i_sb, __func__,
 402                              "dx entry: limit != root limit");
 403                 brelse(bh);
 404                 *err = ERR_BAD_DX_DIR;
 405                 goto fail;
 406         }
 407
 408         dxtrace(printk("Look up %x", hash));
 409         while (1)
 410         {
 411                 count = dx_get_count(entries);
 412                 if (!count || count > dx_get_limit(entries)) {
 413                         ext4_warning(dir->i_sb, __func__,
 414                                      "dx entry: no count or count > limit");
 415                         brelse(bh);
 416                         *err = ERR_BAD_DX_DIR;
 417                         goto fail2;
 418                 }
 419
 420                 p = entries + 1;
 421                 q = entries + count - 1;
 422                 while (p <= q)
 423                 {
 424                         m = p + (q - p)/2;
 425                         dxtrace(printk("."));
 426                         if (dx_get_hash(m) > hash)
 427                                 q = m - 1;
 428                         else
 429                                 p = m + 1;
 430                 }
 431
 432                 if (0) // linear search cross check
 433                 {
 434                         unsigned n = count - 1;
 435                         at = entries;
 436                         while (n--)
 437                         {
 438                                 dxtrace(printk(","));
 439                                 if (dx_get_hash(++at) > hash)
 440                                 {
 441                                         at--;
 442                                         break;
 443                                 }
 444                         }
 445                         assert (at == p - 1);
 446                 }
 447
 448                 at = p - 1;
 449                 dxtrace(printk(" %x->%u\n", at == entries? 0: dx_get_hash(at), dx_get_block(at)));
 450                 frame->bh = bh;
 451                 frame->entries = entries;
 452                 frame->at = at;
 453                 if (!indirect--) return frame;
 454                 if (!(bh = ext4_bread (NULL,dir, dx_get_block(at), 0, err)))
 455                         goto fail2;
 456                 at = entries = ((struct dx_node *) bh->b_data)->entries;
 457                 if (dx_get_limit(entries) != dx_node_limit (dir)) {
 458                         ext4_warning(dir->i_sb, __func__,
 459                                      "dx entry: limit != node limit");
 460                         brelse(bh);
 461                         *err = ERR_BAD_DX_DIR;
 462                         goto fail2;
 463                 }
 464                 frame++;
 465                 frame->bh = NULL;
 466         }
 467 fail2:
 468         while (frame >= frame_in) {
 469                 brelse(frame->bh);
 470                 frame--;
 471         }
 472 fail:
 473         if (*err == ERR_BAD_DX_DIR)
 474                 ext4_warning(dir->i_sb, __func__,
 475                              "Corrupt dir inode %ld, running e2fsck is "
 476                              "recommended.", dir->i_ino);
 477         return NULL;
 478 }
 479
 480 static void dx_release (struct dx_frame *frames)
 481 {
 482         if (frames[0].bh == NULL)
 483                 return;
 484
 485         if (((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels)
 486                 brelse(frames[1].bh);
 487         brelse(frames[0].bh);
 488 }
 489
 490 /*
 491  * This function increments the frame pointer to search the next leaf
 492  * block, and reads in the necessary intervening nodes if the search
 493  * should be necessary.  Whether or not the search is necessary is
 494  * controlled by the hash parameter.  If the hash value is even, then
 495  * the search is only continued if the next block starts with that
 496  * hash value.  This is used if we are searching for a specific file.
 497  *
 498  * If the hash value is HASH_NB_ALWAYS, then always go to the next block.
 499  *
 500  * This function returns 1 if the caller should continue to search,
 501  * or 0 if it should not.  If there is an error reading one of the
 502  * index blocks, it will a negative error code.
 503  *
 504  * If start_hash is non-null, it will be filled in with the starting
 505  * hash of the next page.
 506  */
 507 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
 508                                  struct dx_frame *frame,
 509                                  struct dx_frame *frames,
 510                                  __u32 *start_hash)
 511 {
 512         struct dx_frame *p;
 513         struct buffer_head *bh;
 514         int err, num_frames = 0;
 515         __u32 bhash;
 516
 517         p = frame;
 518         /*
 519          * Find the next leaf page by incrementing the frame pointer.
 520          * If we run out of entries in the interior node, loop around and
 521          * increment pointer in the parent node.  When we break out of
 522          * this loop, num_frames indicates the number of interior
 523          * nodes need to be read.
 524          */
 525         while (1) {
 526                 if (++(p->at) < p->entries + dx_get_count(p->entries))
 527                         break;
 528                 if (p == frames)
 529                         return 0;
 530                 num_frames++;
 531                 p--;
 532         }
 533
 534         /*
 535          * If the hash is 1, then continue only if the next page has a
 536          * continuation hash of any value.  This is used for readdir
 537          * handling.  Otherwise, check to see if the hash matches the
 538          * desired contiuation hash.  If it doesn't, return since
 539          * there's no point to read in the successive index pages.
 540          */
 541         bhash = dx_get_hash(p->at);
 542         if (start_hash)
 543                 *start_hash = bhash;
 544         if ((hash & 1) == 0) {
 545                 if ((bhash & ~1) != hash)
 546                         return 0;
 547         }
 548         /*
 549          * If the hash is HASH_NB_ALWAYS, we always go to the next
 550          * block so no check is necessary
 551          */
 552         while (num_frames--) {
 553                 if (!(bh = ext4_bread(NULL, dir, dx_get_block(p->at),
 554                                       0, &err)))
 555                         return err; /* Failure */
 556                 p++;
 557                 brelse(p->bh);
 558                 p->bh = bh;
 559                 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
 560         }
 561         return 1;
 562 }
 563
 564
 565 /*
 566  * This function fills a red-black tree with information from a
 567  * directory block.  It returns the number directory entries loaded
 568  * into the tree.  If there is an error it is returned in err.
 569  */
 570 static int htree_dirblock_to_tree(struct file *dir_file,
 571                                   struct inode *dir, ext4_lblk_t block,
 572                                   struct dx_hash_info *hinfo,
 573                                   __u32 start_hash, __u32 start_minor_hash)
 574 {
 575         struct buffer_head *bh;
 576         struct ext4_dir_entry_2 *de, *top;
 577         int err, count = 0;
 578
 579         dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
 580                                                         (unsigned long)block));
 581         if (!(bh = ext4_bread (NULL, dir, block, 0, &err)))
 582                 return err;
 583
 584         de = (struct ext4_dir_entry_2 *) bh->b_data;
 585         top = (struct ext4_dir_entry_2 *) ((char *) de +
 586                                            dir->i_sb->s_blocksize -
 587                                            EXT4_DIR_REC_LEN(0));
 588         for (; de < top; de = ext4_next_entry(de)) {
 589                 if (!ext4_check_dir_entry("htree_dirblock_to_tree", dir, de, bh,
 590                                         (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
 591                                                 +((char *)de - bh->b_data))) {
 592                         /* On error, skip the f_pos to the next block. */
 593                         dir_file->f_pos = (dir_file->f_pos |
 594                                         (dir->i_sb->s_blocksize - 1)) + 1;
 595                         brelse(bh);
 596                         return count;
 597                 }
 598                 ext4fs_dirhash(de->name, de->name_len, hinfo);
 599                 if ((hinfo->hash < start_hash) ||
 600                     ((hinfo->hash == start_hash) &&
 601                      (hinfo->minor_hash < start_minor_hash)))
 602                         continue;
 603                 if (de->inode == 0)
 604                         continue;
 605                 if ((err = ext4_htree_store_dirent(dir_file,
 606                                    hinfo->hash, hinfo->minor_hash, de)) != 0) {
 607                         brelse(bh);
 608                         return err;
 609                 }
 610                 count++;
 611         }
 612         brelse(bh);
 613         return count;
 614 }
 615
 616
 617 /*
 618  * This function fills a red-black tree with information from a
 619  * directory.  We start scanning the directory in hash order, starting
 620  * at start_hash and start_minor_hash.
 621  *
 622  * This function returns the number of entries inserted into the tree,
 623  * or a negative error code.
 624  */
 625 int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
 626                          __u32 start_minor_hash, __u32 *next_hash)
 627 {
 628         struct dx_hash_info hinfo;
 629         struct ext4_dir_entry_2 *de;
 630         struct dx_frame frames[2], *frame;
 631         struct inode *dir;
 632         ext4_lblk_t block;
 633         int count = 0;
 634         int ret, err;
 635         __u32 hashval;
 636
 637         dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
 638                        start_hash, start_minor_hash));
 639         dir = dir_file->f_path.dentry->d_inode;
 640         if (!(EXT4_I(dir)->i_flags & EXT4_INDEX_FL)) {
 641                 hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
 642                 if (hinfo.hash_version <= DX_HASH_TEA)
 643                         hinfo.hash_version +=
 644                                 EXT4_SB(dir->i_sb)->s_hash_unsigned;
 645                 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
 646                 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
 647                                                start_hash, start_minor_hash);
 648                 *next_hash = ~0;
 649                 return count;
 650         }
 651         hinfo.hash = start_hash;
 652         hinfo.minor_hash = 0;
 653         frame = dx_probe(NULL, dir, &hinfo, frames, &err);
 654         if (!frame)
 655                 return err;
 656
 657         /* Add '.' and '..' from the htree header */
 658         if (!start_hash && !start_minor_hash) {
 659                 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
 660                 if ((err = ext4_htree_store_dirent(dir_file, 0, 0, de)) != 0)
 661                         goto errout;
 662                 count++;
 663         }
 664         if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
 665                 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
 666                 de = ext4_next_entry(de);
 667                 if ((err = ext4_htree_store_dirent(dir_file, 2, 0, de)) != 0)
 668                         goto errout;
 669                 count++;
 670         }
 671
 672         while (1) {
 673                 block = dx_get_block(frame->at);
 674                 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
 675                                              start_hash, start_minor_hash);
 676                 if (ret < 0) {
 677                         err = ret;
 678                         goto errout;
 679                 }
 680                 count += ret;
 681                 hashval = ~0;
 682                 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
 683                                             frame, frames, &hashval);
 684                 *next_hash = hashval;
 685                 if (ret < 0) {
 686                         err = ret;
 687                         goto errout;
 688                 }
 689                 /*
 690                  * Stop if:  (a) there are no more entries, or
 691                  * (b) we have inserted at least one entry and the
 692                  * next hash value is not a continuation
 693                  */
 694                 if ((ret == 0) ||
 695                     (count && ((hashval & 1) == 0)))
 696                         break;
 697         }
 698         dx_release(frames);
 699         dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, "
 700                        "next hash: %x\n", count, *next_hash));
 701         return count;
 702 errout:
 703         dx_release(frames);
 704         return (err);
 705 }
 706
 707
 708 /*
 709  * Directory block splitting, compacting
 710  */
 711
 712 /*
 713  * Create map of hash values, offsets, and sizes, stored at end of block.
 714  * Returns number of entries mapped.
 715  */
 716 static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize,
 717                        struct dx_hash_info *hinfo,
 718                        struct dx_map_entry *map_tail)
 719 {
 720         int count = 0;
 721         char *base = (char *) de;
 722         struct dx_hash_info h = *hinfo;
 723
 724         while ((char *) de < base + blocksize) {
 725                 if (de->name_len && de->inode) {
 726                         ext4fs_dirhash(de->name, de->name_len, &h);
 727                         map_tail--;
 728                         map_tail->hash = h.hash;
 729                         map_tail->offs = (u16) ((char *) de - base);
 730                         map_tail->size = le16_to_cpu(de->rec_len);
 731                         count++;
 732                         cond_resched();
 733                 }
 734                 /* XXX: do we need to check rec_len == 0 case? -Chris */
 735                 de = ext4_next_entry(de);
 736         }
 737         return count;
 738 }
 739
 740 /* Sort map by hash value */
 741 static void dx_sort_map (struct dx_map_entry *map, unsigned count)
 742 {
 743         struct dx_map_entry *p, *q, *top = map + count - 1;
 744         int more;
 745         /* Combsort until bubble sort doesn't suck */
 746         while (count > 2) {
 747                 count = count*10/13;
 748                 if (count - 9 < 2) /* 9, 10 -> 11 */
 749                         count = 11;
 750                 for (p = top, q = p - count; q >= map; p--, q--)
 751                         if (p->hash < q->hash)
 752                                 swap(*p, *q);
 753         }
 754         /* Garden variety bubble sort */
 755         do {
 756                 more = 0;
 757                 q = top;
 758                 while (q-- > map) {
 759                         if (q[1].hash >= q[0].hash)
 760                                 continue;
 761                         swap(*(q+1), *q);
 762                         more = 1;
 763                 }
 764         } while(more);
 765 }
 766
 767 static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
 768 {
 769         struct dx_entry *entries = frame->entries;
 770         struct dx_entry *old = frame->at, *new = old + 1;
 771         int count = dx_get_count(entries);
 772
 773         assert(count < dx_get_limit(entries));
 774         assert(old < entries + count);
 775         memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
 776         dx_set_hash(new, hash);
 777         dx_set_block(new, block);
 778         dx_set_count(entries, count + 1);
 779 }
 780
 781 static void ext4_update_dx_flag(struct inode *inode)
 782 {
 783         if (!EXT4_HAS_COMPAT_FEATURE(inode->i_sb,
 784                                      EXT4_FEATURE_COMPAT_DIR_INDEX))
 785                 EXT4_I(inode)->i_flags &= ~EXT4_INDEX_FL;
 786 }
 787
 788 /*
 789  * NOTE! unlike strncmp, ext4_match returns 1 for success, 0 for failure.
 790  *
 791  * `len <= EXT4_NAME_LEN' is guaranteed by caller.
 792  * `de != NULL' is guaranteed by caller.
 793  */
 794 static inline int ext4_match (int len, const char * const name,
 795                               struct ext4_dir_entry_2 * de)
 796 {
 797         if (len != de->name_len)
 798                 return 0;
 799         if (!de->inode)
 800                 return 0;
 801         return !memcmp(name, de->name, len);
 802 }
 803
 804 /*
 805  * Returns 0 if not found, -1 on failure, and 1 on success
 806  */
 807 static inline int search_dirblock(struct buffer_head *bh,
 808                                   struct inode *dir,
 809                                   const struct qstr *d_name,
 810                                   unsigned int offset,
 811                                   struct ext4_dir_entry_2 ** res_dir)
 812 {
 813         struct ext4_dir_entry_2 * de;
 814         char * dlimit;
 815         int de_len;
 816         const char *name = d_name->name;
 817         int namelen = d_name->len;
 818
 819         de = (struct ext4_dir_entry_2 *) bh->b_data;
 820         dlimit = bh->b_data + dir->i_sb->s_blocksize;
 821         while ((char *) de < dlimit) {
 822                 /* this code is executed quadratically often */
 823                 /* do minimal checking `by hand' */
 824
 825                 if ((char *) de + namelen <= dlimit &&
 826                     ext4_match (namelen, name, de)) {
 827                         /* found a match - just to be sure, do a full check */
 828                         if (!ext4_check_dir_entry("ext4_find_entry",
 829                                                   dir, de, bh, offset))
 830                                 return -1;
 831                         *res_dir = de;
 832                         return 1;
 833                 }
 834                 /* prevent looping on a bad block */
 835                 de_len = ext4_rec_len_from_disk(de->rec_len);
 836                 if (de_len <= 0)
 837                         return -1;
 838                 offset += de_len;
 839                 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
 840         }
 841         return 0;
 842 }
 843
 844
 845 /*
 846  *      ext4_find_entry()
 847  *
 848  * finds an entry in the specified directory with the wanted name. It
 849  * returns the cache buffer in which the entry was found, and the entry
 850  * itself (as a parameter - res_dir). It does NOT read the inode of the
 851  * entry - you'll have to do that yourself if you want to.
 852  *
 853  * The returned buffer_head has ->b_count elevated.  The caller is expected
 854  * to brelse() it when appropriate.
 855  */
 856 static struct buffer_head * ext4_find_entry (struct inode *dir,
 857                                         const struct qstr *d_name,
 858                                         struct ext4_dir_entry_2 ** res_dir)
 859 {
 860         struct super_block *sb;
 861         struct buffer_head *bh_use[NAMEI_RA_SIZE];
 862         struct buffer_head *bh, *ret = NULL;
 863         ext4_lblk_t start, block, b;
 864         int ra_max = 0;         /* Number of bh's in the readahead
 865                                    buffer, bh_use[] */
 866         int ra_ptr = 0;         /* Current index into readahead
 867                                    buffer */
 868         int num = 0;
 869         ext4_lblk_t  nblocks;
 870         int i, err;
 871         int namelen;
 872
 873         *res_dir = NULL;
 874         sb = dir->i_sb;
 875         namelen = d_name->len;
 876         if (namelen > EXT4_NAME_LEN)
 877                 return NULL;
 878         if (is_dx(dir)) {
 879                 bh = ext4_dx_find_entry(dir, d_name, res_dir, &err);
 880                 /*
 881                  * On success, or if the error was file not found,
 882                  * return.  Otherwise, fall back to doing a search the
 883                  * old fashioned way.
 884                  */
 885                 if (bh || (err != ERR_BAD_DX_DIR))
 886                         return bh;
 887                 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
 888                                "falling back\n"));
 889         }
 890         nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
 891         start = EXT4_I(dir)->i_dir_start_lookup;
 892         if (start >= nblocks)
 893                 start = 0;
 894         block = start;
 895 restart:
 896         do {
 897                 /*
 898                  * We deal with the read-ahead logic here.
 899                  */
 900                 if (ra_ptr >= ra_max) {
 901                         /* Refill the readahead buffer */
 902                         ra_ptr = 0;
 903                         b = block;
 904                         for (ra_max = 0; ra_max < NAMEI_RA_SIZE; ra_max++) {
 905                                 /*
 906                                  * Terminate if we reach the end of the
 907                                  * directory and must wrap, or if our
 908                                  * search has finished at this block.
 909                                  */
 910                                 if (b >= nblocks || (num && block == start)) {
 911                                         bh_use[ra_max] = NULL;
 912                                         break;
 913                                 }
 914                                 num++;
 915                                 bh = ext4_getblk(NULL, dir, b++, 0, &err);
 916                                 bh_use[ra_max] = bh;
 917                                 if (bh)
 918                                         ll_rw_block(READ_META, 1, &bh);
 919                         }
 920                 }
 921                 if ((bh = bh_use[ra_ptr++]) == NULL)
 922                         goto next;
 923                 wait_on_buffer(bh);
 924                 if (!buffer_uptodate(bh)) {
 925                         /* read error, skip block & hope for the best */
 926                         ext4_error(sb, __func__, "reading directory #%lu "
 927                                    "offset %lu", dir->i_ino,
 928                                    (unsigned long)block);
 929                         brelse(bh);
 930                         goto next;
 931                 }
 932                 i = search_dirblock(bh, dir, d_name,
 933                             block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
 934                 if (i == 1) {
 935                         EXT4_I(dir)->i_dir_start_lookup = block;
 936                         ret = bh;
 937                         goto cleanup_and_exit;
 938                 } else {
 939                         brelse(bh);
 940                         if (i < 0)
 941                                 goto cleanup_and_exit;
 942                 }
 943         next:
 944                 if (++block >= nblocks)
 945                         block = 0;
 946         } while (block != start);
 947
 948         /*
 949          * If the directory has grown while we were searching, then
 950          * search the last part of the directory before giving up.
 951          */
 952         block = nblocks;
 953         nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
 954         if (block < nblocks) {
 955                 start = 0;
 956                 goto restart;
 957         }
 958
 959 cleanup_and_exit:
 960         /* Clean up the read-ahead blocks */
 961         for (; ra_ptr < ra_max; ra_ptr++)
 962                 brelse(bh_use[ra_ptr]);
 963         return ret;
 964 }
 965
 966 static struct buffer_head * ext4_dx_find_entry(struct inode *dir, const struct qstr *d_name,
 967                        struct ext4_dir_entry_2 **res_dir, int *err)
 968 {
 969         struct super_block * sb;
 970         struct dx_hash_info     hinfo;
 971         u32 hash;
 972         struct dx_frame frames[2], *frame;
 973         struct ext4_dir_entry_2 *de, *top;
 974         struct buffer_head *bh;
 975         ext4_lblk_t block;
 976         int retval;
 977         int namelen = d_name->len;
 978         const u8 *name = d_name->name;
 979
 980         sb = dir->i_sb;
 981         /* NFS may look up ".." - look at dx_root directory block */
 982         if (namelen > 2 || name[0] != '.'||(name[1] != '.' && name[1] != '\0')){
 983                 if (!(frame = dx_probe(d_name, dir, &hinfo, frames, err)))
 984                         return NULL;
 985         } else {
 986                 frame = frames;
 987                 frame->bh = NULL;                       /* for dx_release() */
 988                 frame->at = (struct dx_entry *)frames;  /* hack for zero entry*/
 989                 dx_set_block(frame->at, 0);             /* dx_root block is 0 */
 990         }
 991         hash = hinfo.hash;
 992         do {
 993                 block = dx_get_block(frame->at);
 994                 if (!(bh = ext4_bread (NULL,dir, block, 0, err)))
 995                         goto errout;
 996                 de = (struct ext4_dir_entry_2 *) bh->b_data;
 997                 top = (struct ext4_dir_entry_2 *) ((char *) de + sb->s_blocksize -
 998                                        EXT4_DIR_REC_LEN(0));
 999                 for (; de < top; de = ext4_next_entry(de)) {
1000                         int off = (block << EXT4_BLOCK_SIZE_BITS(sb))
1001                                   + ((char *) de - bh->b_data);
1002
1003                         if (!ext4_check_dir_entry(__func__, dir, de, bh, off)) {
1004                                 brelse(bh);
1005                                 *err = ERR_BAD_DX_DIR;
1006                                 goto errout;
1007                         }
1008
1009                         if (ext4_match(namelen, name, de)) {
1010                                 *res_dir = de;
1011                                 dx_release(frames);
1012                                 return bh;
1013                         }
1014                 }
1015                 brelse(bh);
1016                 /* Check to see if we should continue to search */
1017                 retval = ext4_htree_next_block(dir, hash, frame,
1018                                                frames, NULL);
1019                 if (retval < 0) {
1020                         ext4_warning(sb, __func__,
1021                              "error reading index page in directory #%lu",
1022                              dir->i_ino);
1023                         *err = retval;
1024                         goto errout;
1025                 }
1026         } while (retval == 1);
1027
1028         *err = -ENOENT;
1029 errout:
1030         dxtrace(printk(KERN_DEBUG "%s not found\n", name));
1031         dx_release (frames);
1032         return NULL;
1033 }
1034
1035 static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
1036 {
1037         struct inode *inode;
1038         struct ext4_dir_entry_2 *de;
1039         struct buffer_head *bh;
1040
1041         if (dentry->d_name.len > EXT4_NAME_LEN)
1042                 return ERR_PTR(-ENAMETOOLONG);
1043
1044         bh = ext4_find_entry(dir, &dentry->d_name, &de);
1045         inode = NULL;
1046         if (bh) {
1047                 __u32 ino = le32_to_cpu(de->inode);
1048                 brelse(bh);
1049                 if (!ext4_valid_inum(dir->i_sb, ino)) {
1050                         ext4_error(dir->i_sb, "ext4_lookup",
1051                                    "bad inode number: %u", ino);
1052                         return ERR_PTR(-EIO);
1053                 }
1054                 inode = ext4_iget(dir->i_sb, ino);
1055                 if (IS_ERR(inode))
1056                         return ERR_CAST(inode);
1057         }
1058         return d_splice_alias(inode, dentry);
1059 }
1060
1061
1062 struct dentry *ext4_get_parent(struct dentry *child)
1063 {
1064         __u32 ino;
1065         struct inode *inode;
1066         static const struct qstr dotdot = {
1067                 .name = "..",
1068                 .len = 2,
1069         };
1070         struct ext4_dir_entry_2 * de;
1071         struct buffer_head *bh;
1072
1073         bh = ext4_find_entry(child->d_inode, &dotdot, &de);
1074         inode = NULL;
1075         if (!bh)
1076                 return ERR_PTR(-ENOENT);
1077         ino = le32_to_cpu(de->inode);
1078         brelse(bh);
1079
1080         if (!ext4_valid_inum(child->d_inode->i_sb, ino)) {
1081                 ext4_error(child->d_inode->i_sb, "ext4_get_parent",
1082                            "bad inode number: %u", ino);
1083                 return ERR_PTR(-EIO);
1084         }
1085
1086         return d_obtain_alias(ext4_iget(child->d_inode->i_sb, ino));
1087 }
1088
1089 #define S_SHIFT 12
1090 static unsigned char ext4_type_by_mode[S_IFMT >> S_SHIFT] = {
1091         [S_IFREG >> S_SHIFT]    = EXT4_FT_REG_FILE,
1092         [S_IFDIR >> S_SHIFT]    = EXT4_FT_DIR,
1093         [S_IFCHR >> S_SHIFT]    = EXT4_FT_CHRDEV,
1094         [S_IFBLK >> S_SHIFT]    = EXT4_FT_BLKDEV,
1095         [S_IFIFO >> S_SHIFT]    = EXT4_FT_FIFO,
1096         [S_IFSOCK >> S_SHIFT]   = EXT4_FT_SOCK,
1097         [S_IFLNK >> S_SHIFT]    = EXT4_FT_SYMLINK,
1098 };
1099
1100 static inline void ext4_set_de_type(struct super_block *sb,
1101                                 struct ext4_dir_entry_2 *de,
1102                                 umode_t mode) {
1103         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE))
1104                 de->file_type = ext4_type_by_mode[(mode & S_IFMT)>>S_SHIFT];
1105 }
1106
1107 /*
1108  * Move count entries from end of map between two memory locations.
1109  * Returns pointer to last entry moved.
1110  */
1111 static struct ext4_dir_entry_2 *
1112 dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count)
1113 {
1114         unsigned rec_len = 0;
1115
1116         while (count--) {
1117                 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *) (from + map->offs);
1118                 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1119                 memcpy (to, de, rec_len);
1120                 ((struct ext4_dir_entry_2 *) to)->rec_len =
1121                                 ext4_rec_len_to_disk(rec_len);
1122                 de->inode = 0;
1123                 map++;
1124                 to += rec_len;
1125         }
1126         return (struct ext4_dir_entry_2 *) (to - rec_len);
1127 }
1128
1129 /*
1130  * Compact each dir entry in the range to the minimal rec_len.
1131  * Returns pointer to last entry in range.
1132  */
1133 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize)
1134 {
1135         struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
1136         unsigned rec_len = 0;
1137
1138         prev = to = de;
1139         while ((char*)de < base + blocksize) {
1140                 next = ext4_next_entry(de);
1141                 if (de->inode && de->name_len) {
1142                         rec_len = EXT4_DIR_REC_LEN(de->name_len);
1143                         if (de > to)
1144                                 memmove(to, de, rec_len);
1145                         to->rec_len = ext4_rec_len_to_disk(rec_len);
1146                         prev = to;
1147                         to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
1148                 }
1149                 de = next;
1150         }
1151         return prev;
1152 }
1153
1154 /*
1155  * Split a full leaf block to make room for a new dir entry.
1156  * Allocate a new block, and move entries so that they are approx. equally full.
1157  * Returns pointer to de in block into which the new entry will be inserted.
1158  */
1159 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
1160                         struct buffer_head **bh,struct dx_frame *frame,
1161                         struct dx_hash_info *hinfo, int *error)
1162 {
1163         unsigned blocksize = dir->i_sb->s_blocksize;
1164         unsigned count, continued;
1165         struct buffer_head *bh2;
1166         ext4_lblk_t newblock;
1167         u32 hash2;
1168         struct dx_map_entry *map;
1169         char *data1 = (*bh)->b_data, *data2;
1170         unsigned split, move, size;
1171         struct ext4_dir_entry_2 *de = NULL, *de2;
1172         int     err = 0, i;
1173
1174         bh2 = ext4_append (handle, dir, &newblock, &err);
1175         if (!(bh2)) {
1176                 brelse(*bh);
1177                 *bh = NULL;
1178                 goto errout;
1179         }
1180
1181         BUFFER_TRACE(*bh, "get_write_access");
1182         err = ext4_journal_get_write_access(handle, *bh);
1183         if (err)
1184                 goto journal_error;
1185
1186         BUFFER_TRACE(frame->bh, "get_write_access");
1187         err = ext4_journal_get_write_access(handle, frame->bh);
1188         if (err)
1189                 goto journal_error;
1190
1191         data2 = bh2->b_data;
1192
1193         /* create map in the end of data2 block */
1194         map = (struct dx_map_entry *) (data2 + blocksize);
1195         count = dx_make_map((struct ext4_dir_entry_2 *) data1,
1196                              blocksize, hinfo, map);
1197         map -= count;
1198         dx_sort_map(map, count);
1199         /* Split the existing block in the middle, size-wise */
1200         size = 0;
1201         move = 0;
1202         for (i = count-1; i >= 0; i--) {
1203                 /* is more than half of this entry in 2nd half of the block? */
1204                 if (size + map[i].size/2 > blocksize/2)
1205                         break;
1206                 size += map[i].size;
1207                 move++;
1208         }
1209         /* map index at which we will split */
1210         split = count - move;
1211         hash2 = map[split].hash;
1212         continued = hash2 == map[split - 1].hash;
1213         dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
1214                         (unsigned long)dx_get_block(frame->at),
1215                                         hash2, split, count-split));
1216
1217         /* Fancy dance to stay within two buffers */
1218         de2 = dx_move_dirents(data1, data2, map + split, count - split);
1219         de = dx_pack_dirents(data1, blocksize);
1220         de->rec_len = ext4_rec_len_to_disk(data1 + blocksize - (char *) de);
1221         de2->rec_len = ext4_rec_len_to_disk(data2 + blocksize - (char *) de2);
1222         dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data1, blocksize, 1));
1223         dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data2, blocksize, 1));
1224
1225         /* Which block gets the new entry? */
1226         if (hinfo->hash >= hash2)
1227         {
1228                 swap(*bh, bh2);
1229                 de = de2;
1230         }
1231         dx_insert_block(frame, hash2 + continued, newblock);
1232         err = ext4_handle_dirty_metadata(handle, dir, bh2);
1233         if (err)
1234                 goto journal_error;
1235         err = ext4_handle_dirty_metadata(handle, dir, frame->bh);
1236         if (err)
1237                 goto journal_error;
1238         brelse(bh2);
1239         dxtrace(dx_show_index("frame", frame->entries));
1240         return de;
1241
1242 journal_error:
1243         brelse(*bh);
1244         brelse(bh2);
1245         *bh = NULL;
1246         ext4_std_error(dir->i_sb, err);
1247 errout:
1248         *error = err;
1249         return NULL;
1250 }
1251
1252 /*
1253  * Add a new entry into a directory (leaf) block.  If de is non-NULL,
1254  * it points to a directory entry which is guaranteed to be large
1255  * enough for new directory entry.  If de is NULL, then
1256  * add_dirent_to_buf will attempt search the directory block for
1257  * space.  It will return -ENOSPC if no space is available, and -EIO
1258  * and -EEXIST if directory entry already exists.
1259  *
1260  * NOTE!  bh is NOT released in the case where ENOSPC is returned.  In
1261  * all other cases bh is released.
1262  */
1263 static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
1264                              struct inode *inode, struct ext4_dir_entry_2 *de,
1265                              struct buffer_head *bh)
1266 {
1267         struct inode    *dir = dentry->d_parent->d_inode;
1268         const char      *name = dentry->d_name.name;
1269         int             namelen = dentry->d_name.len;
1270         unsigned int    offset = 0;
1271         unsigned short  reclen;
1272         int             nlen, rlen, err;
1273         char            *top;
1274
1275         reclen = EXT4_DIR_REC_LEN(namelen);
1276         if (!de) {
1277                 de = (struct ext4_dir_entry_2 *)bh->b_data;
1278                 top = bh->b_data + dir->i_sb->s_blocksize - reclen;
1279                 while ((char *) de <= top) {
1280                         if (!ext4_check_dir_entry("ext4_add_entry", dir, de,
1281                                                   bh, offset)) {
1282                                 brelse(bh);
1283                                 return -EIO;
1284                         }
1285                         if (ext4_match(namelen, name, de)) {
1286                                 brelse(bh);
1287                                 return -EEXIST;
1288                         }
1289                         nlen = EXT4_DIR_REC_LEN(de->name_len);
1290                         rlen = ext4_rec_len_from_disk(de->rec_len);
1291                         if ((de->inode? rlen - nlen: rlen) >= reclen)
1292                                 break;
1293                         de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
1294                         offset += rlen;
1295                 }
1296                 if ((char *) de > top)
1297                         return -ENOSPC;
1298         }
1299         BUFFER_TRACE(bh, "get_write_access");
1300         err = ext4_journal_get_write_access(handle, bh);
1301         if (err) {
1302                 ext4_std_error(dir->i_sb, err);
1303                 brelse(bh);
1304                 return err;
1305         }
1306
1307         /* By now the buffer is marked for journaling */
1308         nlen = EXT4_DIR_REC_LEN(de->name_len);
1309         rlen = ext4_rec_len_from_disk(de->rec_len);
1310         if (de->inode) {
1311                 struct ext4_dir_entry_2 *de1 = (struct ext4_dir_entry_2 *)((char *)de + nlen);
1312                 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen);
1313                 de->rec_len = ext4_rec_len_to_disk(nlen);
1314                 de = de1;
1315         }
1316         de->file_type = EXT4_FT_UNKNOWN;
1317         if (inode) {
1318                 de->inode = cpu_to_le32(inode->i_ino);
1319                 ext4_set_de_type(dir->i_sb, de, inode->i_mode);
1320         } else
1321                 de->inode = 0;
1322         de->name_len = namelen;
1323         memcpy(de->name, name, namelen);
1324         /*
1325          * XXX shouldn't update any times until successful
1326          * completion of syscall, but too many callers depend
1327          * on this.
1328          *
1329          * XXX similarly, too many callers depend on
1330          * ext4_new_inode() setting the times, but error
1331          * recovery deletes the inode, so the worst that can
1332          * happen is that the times are slightly out of date
1333          * and/or different from the directory change time.
1334          */
1335         dir->i_mtime = dir->i_ctime = ext4_current_time(dir);
1336         ext4_update_dx_flag(dir);
1337         dir->i_version++;
1338         ext4_mark_inode_dirty(handle, dir);
1339         BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1340         err = ext4_handle_dirty_metadata(handle, dir, bh);
1341         if (err)
1342                 ext4_std_error(dir->i_sb, err);
1343         brelse(bh);
1344         return 0;
1345 }
1346
1347 /*
1348  * This converts a one block unindexed directory to a 3 block indexed
1349  * directory, and adds the dentry to the indexed directory.
1350  */
1351 static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
1352                             struct inode *inode, struct buffer_head *bh)
1353 {
1354         struct inode    *dir = dentry->d_parent->d_inode;
1355         const char      *name = dentry->d_name.name;
1356         int             namelen = dentry->d_name.len;
1357         struct buffer_head *bh2;
1358         struct dx_root  *root;
1359         struct dx_frame frames[2], *frame;
1360         struct dx_entry *entries;
1361         struct ext4_dir_entry_2 *de, *de2;
1362         char            *data1, *top;
1363         unsigned        len;
1364         int             retval;
1365         unsigned        blocksize;
1366         struct dx_hash_info hinfo;
1367         ext4_lblk_t  block;
1368         struct fake_dirent *fde;
1369
1370         blocksize =  dir->i_sb->s_blocksize;
1371         dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
1372         retval = ext4_journal_get_write_access(handle, bh);
1373         if (retval) {
1374                 ext4_std_error(dir->i_sb, retval);
1375                 brelse(bh);
1376                 return retval;
1377         }
1378         root = (struct dx_root *) bh->b_data;
1379
1380         /* The 0th block becomes the root, move the dirents out */
1381         fde = &root->dotdot;
1382         de = (struct ext4_dir_entry_2 *)((char *)fde +
1383                 ext4_rec_len_from_disk(fde->rec_len));
1384         if ((char *) de >= (((char *) root) + blocksize)) {
1385                 ext4_error(dir->i_sb, __func__,
1386                            "invalid rec_len for '..' in inode %lu",
1387                            dir->i_ino);
1388                 brelse(bh);
1389                 return -EIO;
1390         }
1391         len = ((char *) root) + blocksize - (char *) de;
1392
1393         /* Allocate new block for the 0th block's dirents */
1394         bh2 = ext4_append(handle, dir, &block, &retval);
1395         if (!(bh2)) {
1396                 brelse(bh);
1397                 return retval;
1398         }
1399         EXT4_I(dir)->i_flags |= EXT4_INDEX_FL;
1400         data1 = bh2->b_data;
1401
1402         memcpy (data1, de, len);
1403         de = (struct ext4_dir_entry_2 *) data1;
1404         top = data1 + len;
1405         while ((char *)(de2 = ext4_next_entry(de)) < top)
1406                 de = de2;
1407         de->rec_len = ext4_rec_len_to_disk(data1 + blocksize - (char *) de);
1408         /* Initialize the root; the dot dirents already exist */
1409         de = (struct ext4_dir_entry_2 *) (&root->dotdot);
1410         de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2));
1411         memset (&root->info, 0, sizeof(root->info));
1412         root->info.info_length = sizeof(root->info);
1413         root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
1414         entries = root->entries;
1415         dx_set_block(entries, 1);
1416         dx_set_count(entries, 1);
1417         dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
1418
1419         /* Initialize as for dx_probe */
1420         hinfo.hash_version = root->info.hash_version;
1421         if (hinfo.hash_version <= DX_HASH_TEA)
1422                 hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
1423         hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
1424         ext4fs_dirhash(name, namelen, &hinfo);
1425         frame = frames;
1426         frame->entries = entries;
1427         frame->at = entries;
1428         frame->bh = bh;
1429         bh = bh2;
1430         de = do_split(handle,dir, &bh, frame, &hinfo, &retval);
1431         dx_release (frames);
1432         if (!(de))
1433                 return retval;
1434
1435         return add_dirent_to_buf(handle, dentry, inode, de, bh);
1436 }
1437
1438 /*
1439  *      ext4_add_entry()
1440  *
1441  * adds a file entry to the specified directory, using the same
1442  * semantics as ext4_find_entry(). It returns NULL if it failed.
1443  *
1444  * NOTE!! The inode part of 'de' is left at 0 - which means you
1445  * may not sleep between calling this and putting something into
1446  * the entry, as someone else might have used it while you slept.
1447  */
1448 static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
1449                           struct inode *inode)
1450 {
1451         struct inode *dir = dentry->d_parent->d_inode;
1452         struct buffer_head *bh;
1453         struct ext4_dir_entry_2 *de;
1454         struct super_block *sb;
1455         int     retval;
1456         int     dx_fallback=0;
1457         unsigned blocksize;
1458         ext4_lblk_t block, blocks;
1459
1460         sb = dir->i_sb;
1461         blocksize = sb->s_blocksize;
1462         if (!dentry->d_name.len)
1463                 return -EINVAL;
1464         if (is_dx(dir)) {
1465                 retval = ext4_dx_add_entry(handle, dentry, inode);
1466                 if (!retval || (retval != ERR_BAD_DX_DIR))
1467                         return retval;
1468                 EXT4_I(dir)->i_flags &= ~EXT4_INDEX_FL;
1469                 dx_fallback++;
1470                 ext4_mark_inode_dirty(handle, dir);
1471         }
1472         blocks = dir->i_size >> sb->s_blocksize_bits;
1473         for (block = 0; block < blocks; block++) {
1474                 bh = ext4_bread(handle, dir, block, 0, &retval);
1475                 if(!bh)
1476                         return retval;
1477                 retval = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
1478                 if (retval != -ENOSPC)
1479                         return retval;
1480
1481                 if (blocks == 1 && !dx_fallback &&
1482                     EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX))
1483                         return make_indexed_dir(handle, dentry, inode, bh);
1484                 brelse(bh);
1485         }
1486         bh = ext4_append(handle, dir, &block, &retval);
1487         if (!bh)
1488                 return retval;
1489         de = (struct ext4_dir_entry_2 *) bh->b_data;
1490         de->inode = 0;
1491         de->rec_len = ext4_rec_len_to_disk(blocksize);
1492         return add_dirent_to_buf(handle, dentry, inode, de, bh);
1493 }
1494
1495 /*
1496  * Returns 0 for success, or a negative error value
1497  */
1498 static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
1499                              struct inode *inode)
1500 {
1501         struct dx_frame frames[2], *frame;
1502         struct dx_entry *entries, *at;
1503         struct dx_hash_info hinfo;
1504         struct buffer_head *bh;
1505         struct inode *dir = dentry->d_parent->d_inode;
1506         struct super_block *sb = dir->i_sb;
1507         struct ext4_dir_entry_2 *de;
1508         int err;
1509
1510         frame = dx_probe(&dentry->d_name, dir, &hinfo, frames, &err);
1511         if (!frame)
1512                 return err;
1513         entries = frame->entries;
1514         at = frame->at;
1515
1516         if (!(bh = ext4_bread(handle,dir, dx_get_block(frame->at), 0, &err)))
1517                 goto cleanup;
1518
1519         BUFFER_TRACE(bh, "get_write_access");
1520         err = ext4_journal_get_write_access(handle, bh);
1521         if (err)
1522                 goto journal_error;
1523
1524         err = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
1525         if (err != -ENOSPC) {
1526                 bh = NULL;
1527                 goto cleanup;
1528         }
1529
1530         /* Block full, should compress but for now just split */
1531         dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
1532                        dx_get_count(entries), dx_get_limit(entries)));
1533         /* Need to split index? */
1534         if (dx_get_count(entries) == dx_get_limit(entries)) {
1535                 ext4_lblk_t newblock;
1536                 unsigned icount = dx_get_count(entries);
1537                 int levels = frame - frames;
1538                 struct dx_entry *entries2;
1539                 struct dx_node *node2;
1540                 struct buffer_head *bh2;
1541
1542                 if (levels && (dx_get_count(frames->entries) ==
1543                                dx_get_limit(frames->entries))) {
1544                         ext4_warning(sb, __func__,
1545                                      "Directory index full!");
1546                         err = -ENOSPC;
1547                         goto cleanup;
1548                 }
1549                 bh2 = ext4_append (handle, dir, &newblock, &err);
1550                 if (!(bh2))
1551                         goto cleanup;
1552                 node2 = (struct dx_node *)(bh2->b_data);
1553                 entries2 = node2->entries;
1554                 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize);
1555                 node2->fake.inode = 0;
1556                 BUFFER_TRACE(frame->bh, "get_write_access");
1557                 err = ext4_journal_get_write_access(handle, frame->bh);
1558                 if (err)
1559                         goto journal_error;
1560                 if (levels) {
1561                         unsigned icount1 = icount/2, icount2 = icount - icount1;
1562                         unsigned hash2 = dx_get_hash(entries + icount1);
1563                         dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
1564                                        icount1, icount2));
1565
1566                         BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
1567                         err = ext4_journal_get_write_access(handle,
1568                                                              frames[0].bh);
1569                         if (err)
1570                                 goto journal_error;
1571
1572                         memcpy((char *) entries2, (char *) (entries + icount1),
1573                                icount2 * sizeof(struct dx_entry));
1574                         dx_set_count(entries, icount1);
1575                         dx_set_count(entries2, icount2);
1576                         dx_set_limit(entries2, dx_node_limit(dir));
1577
1578                         /* Which index block gets the new entry? */
1579                         if (at - entries >= icount1) {
1580                                 frame->at = at = at - entries - icount1 + entries2;
1581                                 frame->entries = entries = entries2;
1582                                 swap(frame->bh, bh2);
1583                         }
1584                         dx_insert_block(frames + 0, hash2, newblock);
1585                         dxtrace(dx_show_index("node", frames[1].entries));
1586                         dxtrace(dx_show_index("node",
1587                                ((struct dx_node *) bh2->b_data)->entries));
1588                         err = ext4_handle_dirty_metadata(handle, inode, bh2);
1589                         if (err)
1590                                 goto journal_error;
1591                         brelse (bh2);
1592                 } else {
1593                         dxtrace(printk(KERN_DEBUG
1594                                        "Creating second level index...\n"));
1595                         memcpy((char *) entries2, (char *) entries,
1596                                icount * sizeof(struct dx_entry));
1597                         dx_set_limit(entries2, dx_node_limit(dir));
1598
1599                         /* Set up root */
1600                         dx_set_count(entries, 1);
1601                         dx_set_block(entries + 0, newblock);
1602                         ((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels = 1;
1603
1604                         /* Add new access path frame */
1605                         frame = frames + 1;
1606                         frame->at = at = at - entries + entries2;
1607                         frame->entries = entries = entries2;
1608                         frame->bh = bh2;
1609                         err = ext4_journal_get_write_access(handle,
1610                                                              frame->bh);
1611                         if (err)
1612                                 goto journal_error;
1613                 }
1614                 ext4_handle_dirty_metadata(handle, inode, frames[0].bh);
1615         }
1616         de = do_split(handle, dir, &bh, frame, &hinfo, &err);
1617         if (!de)
1618                 goto cleanup;
1619         err = add_dirent_to_buf(handle, dentry, inode, de, bh);
1620         bh = NULL;
1621         goto cleanup;
1622
1623 journal_error:
1624         ext4_std_error(dir->i_sb, err);
1625 cleanup:
1626         if (bh)
1627                 brelse(bh);
1628         dx_release(frames);
1629         return err;
1630 }
1631
1632 /*
1633  * ext4_delete_entry deletes a directory entry by merging it with the
1634  * previous entry
1635  */
1636 static int ext4_delete_entry(handle_t *handle,
1637                              struct inode *dir,
1638                              struct ext4_dir_entry_2 *de_del,
1639                              struct buffer_head *bh)
1640 {
1641         struct ext4_dir_entry_2 *de, *pde;
1642         int i;
1643
1644         i = 0;
1645         pde = NULL;
1646         de = (struct ext4_dir_entry_2 *) bh->b_data;
1647         while (i < bh->b_size) {
1648                 if (!ext4_check_dir_entry("ext4_delete_entry", dir, de, bh, i))
1649                         return -EIO;
1650                 if (de == de_del)  {
1651                         BUFFER_TRACE(bh, "get_write_access");
1652                         ext4_journal_get_write_access(handle, bh);
1653                         if (pde)
1654                                 pde->rec_len = ext4_rec_len_to_disk(
1655                                         ext4_rec_len_from_disk(pde->rec_len) +
1656                                         ext4_rec_len_from_disk(de->rec_len));
1657                         else
1658                                 de->inode = 0;
1659                         dir->i_version++;
1660                         BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1661                         ext4_handle_dirty_metadata(handle, dir, bh);
1662                         return 0;
1663                 }
1664                 i += ext4_rec_len_from_disk(de->rec_len);
1665                 pde = de;
1666                 de = ext4_next_entry(de);
1667         }
1668         return -ENOENT;
1669 }
1670
1671 /*
1672  * DIR_NLINK feature is set if 1) nlinks > EXT4_LINK_MAX or 2) nlinks == 2,
1673  * since this indicates that nlinks count was previously 1.
1674  */
1675 static void ext4_inc_count(handle_t *handle, struct inode *inode)
1676 {
1677         inc_nlink(inode);
1678         if (is_dx(inode) && inode->i_nlink > 1) {
1679                 /* limit is 16-bit i_links_count */
1680                 if (inode->i_nlink >= EXT4_LINK_MAX || inode->i_nlink == 2) {
1681                         inode->i_nlink = 1;
1682                         EXT4_SET_RO_COMPAT_FEATURE(inode->i_sb,
1683                                               EXT4_FEATURE_RO_COMPAT_DIR_NLINK);
1684                 }
1685         }
1686 }
1687
1688 /*
1689  * If a directory had nlink == 1, then we should let it be 1. This indicates
1690  * directory has >EXT4_LINK_MAX subdirs.
1691  */
1692 static void ext4_dec_count(handle_t *handle, struct inode *inode)
1693 {
1694         drop_nlink(inode);
1695         if (S_ISDIR(inode->i_mode) && inode->i_nlink == 0)
1696                 inc_nlink(inode);
1697 }
1698
1699
1700 static int ext4_add_nondir(handle_t *handle,
1701                 struct dentry *dentry, struct inode *inode)
1702 {
1703         int err = ext4_add_entry(handle, dentry, inode);
1704         if (!err) {
1705                 ext4_mark_inode_dirty(handle, inode);
1706                 d_instantiate(dentry, inode);
1707                 unlock_new_inode(inode);
1708                 return 0;
1709         }
1710         drop_nlink(inode);
1711         unlock_new_inode(inode);
1712         iput(inode);
1713         return err;
1714 }
1715
1716 /*
1717  * By the time this is called, we already have created
1718  * the directory cache entry for the new file, but it
1719  * is so far negative - it has no inode.
1720  *
1721  * If the create succeeds, we fill in the inode information
1722  * with d_instantiate().
1723  */
1724 static int ext4_create(struct inode *dir, struct dentry *dentry, int mode,
1725                        struct nameidata *nd)
1726 {
1727         handle_t *handle;
1728         struct inode *inode;
1729         int err, retries = 0;
1730
1731 retry:
1732         handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
1733                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
1734                                         2*EXT4_QUOTA_INIT_BLOCKS(dir->i_sb));
1735         if (IS_ERR(handle))
1736                 return PTR_ERR(handle);
1737
1738         if (IS_DIRSYNC(dir))
1739                 ext4_handle_sync(handle);
1740
1741         inode = ext4_new_inode (handle, dir, mode);
1742         err = PTR_ERR(inode);
1743         if (!IS_ERR(inode)) {
1744                 inode->i_op = &ext4_file_inode_operations;
1745                 inode->i_fop = &ext4_file_operations;
1746                 ext4_set_aops(inode);
1747                 err = ext4_add_nondir(handle, dentry, inode);
1748         }
1749         ext4_journal_stop(handle);
1750         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
1751                 goto retry;
1752         return err;
1753 }
1754
1755 static int ext4_mknod(struct inode *dir, struct dentry *dentry,
1756                       int mode, dev_t rdev)
1757 {
1758         handle_t *handle;
1759         struct inode *inode;
1760         int err, retries = 0;
1761
1762         if (!new_valid_dev(rdev))
1763                 return -EINVAL;
1764
1765 retry:
1766         handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
1767                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
1768                                         2*EXT4_QUOTA_INIT_BLOCKS(dir->i_sb));
1769         if (IS_ERR(handle))
1770                 return PTR_ERR(handle);
1771
1772         if (IS_DIRSYNC(dir))
1773                 ext4_handle_sync(handle);
1774
1775         inode = ext4_new_inode(handle, dir, mode);
1776         err = PTR_ERR(inode);
1777         if (!IS_ERR(inode)) {
1778                 init_special_inode(inode, inode->i_mode, rdev);
1779 #ifdef CONFIG_EXT4_FS_XATTR
1780                 inode->i_op = &ext4_special_inode_operations;
1781 #endif
1782                 err = ext4_add_nondir(handle, dentry, inode);
1783         }
1784         ext4_journal_stop(handle);
1785         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
1786                 goto retry;
1787         return err;
1788 }
1789
1790 static int ext4_mkdir(struct inode *dir, struct dentry *dentry, int mode)
1791 {
1792         handle_t *handle;
1793         struct inode *inode;
1794         struct buffer_head *dir_block;
1795         struct ext4_dir_entry_2 *de;
1796         int err, retries = 0;
1797
1798         if (EXT4_DIR_LINK_MAX(dir))
1799                 return -EMLINK;
1800
1801 retry:
1802         handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
1803                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
1804                                         2*EXT4_QUOTA_INIT_BLOCKS(dir->i_sb));
1805         if (IS_ERR(handle))
1806                 return PTR_ERR(handle);
1807
1808         if (IS_DIRSYNC(dir))
1809                 ext4_handle_sync(handle);
1810
1811         inode = ext4_new_inode(handle, dir, S_IFDIR | mode);
1812         err = PTR_ERR(inode);
1813         if (IS_ERR(inode))
1814                 goto out_stop;
1815
1816         inode->i_op = &ext4_dir_inode_operations;
1817         inode->i_fop = &ext4_dir_operations;
1818         inode->i_size = EXT4_I(inode)->i_disksize = inode->i_sb->s_blocksize;
1819         dir_block = ext4_bread(handle, inode, 0, 1, &err);
1820         if (!dir_block)
1821                 goto out_clear_inode;
1822         BUFFER_TRACE(dir_block, "get_write_access");
1823         ext4_journal_get_write_access(handle, dir_block);
1824         de = (struct ext4_dir_entry_2 *) dir_block->b_data;
1825         de->inode = cpu_to_le32(inode->i_ino);
1826         de->name_len = 1;
1827         de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len));
1828         strcpy(de->name, ".");
1829         ext4_set_de_type(dir->i_sb, de, S_IFDIR);
1830         de = ext4_next_entry(de);
1831         de->inode = cpu_to_le32(dir->i_ino);
1832         de->rec_len = ext4_rec_len_to_disk(inode->i_sb->s_blocksize -
1833                                                 EXT4_DIR_REC_LEN(1));
1834         de->name_len = 2;
1835         strcpy(de->name, "..");
1836         ext4_set_de_type(dir->i_sb, de, S_IFDIR);
1837         inode->i_nlink = 2;
1838         BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
1839         ext4_handle_dirty_metadata(handle, dir, dir_block);
1840         brelse(dir_block);
1841         ext4_mark_inode_dirty(handle, inode);
1842         err = ext4_add_entry(handle, dentry, inode);
1843         if (err) {
1844 out_clear_inode:
1845                 clear_nlink(inode);
1846                 unlock_new_inode(inode);
1847                 ext4_mark_inode_dirty(handle, inode);
1848                 iput(inode);
1849                 goto out_stop;
1850         }
1851         ext4_inc_count(handle, dir);
1852         ext4_update_dx_flag(dir);
1853         ext4_mark_inode_dirty(handle, dir);
1854         d_instantiate(dentry, inode);
1855         unlock_new_inode(inode);
1856 out_stop:
1857         ext4_journal_stop(handle);
1858         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
1859                 goto retry;
1860         return err;
1861 }
1862
1863 /*
1864  * routine to check that the specified directory is empty (for rmdir)
1865  */
1866 static int empty_dir(struct inode *inode)
1867 {
1868         unsigned int offset;
1869         struct buffer_head *bh;
1870         struct ext4_dir_entry_2 *de, *de1;
1871         struct super_block *sb;
1872         int err = 0;
1873
1874         sb = inode->i_sb;
1875         if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2) ||
1876             !(bh = ext4_bread(NULL, inode, 0, 0, &err))) {
1877                 if (err)
1878                         ext4_error(inode->i_sb, __func__,
1879                                    "error %d reading directory #%lu offset 0",
1880                                    err, inode->i_ino);
1881                 else
1882                         ext4_warning(inode->i_sb, __func__,
1883                                      "bad directory (dir #%lu) - no data block",
1884                                      inode->i_ino);
1885                 return 1;
1886         }
1887         de = (struct ext4_dir_entry_2 *) bh->b_data;
1888         de1 = ext4_next_entry(de);
1889         if (le32_to_cpu(de->inode) != inode->i_ino ||
1890                         !le32_to_cpu(de1->inode) ||
1891                         strcmp(".", de->name) ||
1892                         strcmp("..", de1->name)) {
1893                 ext4_warning(inode->i_sb, "empty_dir",
1894                              "bad directory (dir #%lu) - no `.' or `..'",
1895                              inode->i_ino);
1896                 brelse(bh);
1897                 return 1;
1898         }
1899         offset = ext4_rec_len_from_disk(de->rec_len) +
1900                  ext4_rec_len_from_disk(de1->rec_len);
1901         de = ext4_next_entry(de1);
1902         while (offset < inode->i_size) {
1903                 if (!bh ||
1904                         (void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
1905                         err = 0;
1906                         brelse(bh);
1907                         bh = ext4_bread(NULL, inode,
1908                                 offset >> EXT4_BLOCK_SIZE_BITS(sb), 0, &err);
1909                         if (!bh) {
1910                                 if (err)
1911                                         ext4_error(sb, __func__,
1912                                                    "error %d reading directory"
1913                                                    " #%lu offset %u",
1914                                                    err, inode->i_ino, offset);
1915                                 offset += sb->s_blocksize;
1916                                 continue;
1917                         }
1918                         de = (struct ext4_dir_entry_2 *) bh->b_data;
1919                 }
1920                 if (!ext4_check_dir_entry("empty_dir", inode, de, bh, offset)) {
1921                         de = (struct ext4_dir_entry_2 *)(bh->b_data +
1922                                                          sb->s_blocksize);
1923                         offset = (offset | (sb->s_blocksize - 1)) + 1;
1924                         continue;
1925                 }
1926                 if (le32_to_cpu(de->inode)) {
1927                         brelse(bh);
1928                         return 0;
1929                 }
1930                 offset += ext4_rec_len_from_disk(de->rec_len);
1931                 de = ext4_next_entry(de);
1932         }
1933         brelse(bh);
1934         return 1;
1935 }
1936
1937 /* ext4_orphan_add() links an unlinked or truncated inode into a list of
1938  * such inodes, starting at the superblock, in case we crash before the
1939  * file is closed/deleted, or in case the inode truncate spans multiple
1940  * transactions and the last transaction is not recovered after a crash.
1941  *
1942  * At filesystem recovery time, we walk this list deleting unlinked
1943  * inodes and truncating linked inodes in ext4_orphan_cleanup().
1944  */
1945 int ext4_orphan_add(handle_t *handle, struct inode *inode)
1946 {
1947         struct super_block *sb = inode->i_sb;
1948         struct ext4_iloc iloc;
1949         int err = 0, rc;
1950
1951         if (!ext4_handle_valid(handle))
1952                 return 0;
1953
1954         lock_super(sb);
1955         if (!list_empty(&EXT4_I(inode)->i_orphan))
1956                 goto out_unlock;
1957
1958         /* Orphan handling is only valid for files with data blocks
1959          * being truncated, or files being unlinked. */
1960
1961         /* @@@ FIXME: Observation from aviro:
1962          * I think I can trigger J_ASSERT in ext4_orphan_add().  We block
1963          * here (on lock_super()), so race with ext4_link() which might bump
1964          * ->i_nlink. For, say it, character device. Not a regular file,
1965          * not a directory, not a symlink and ->i_nlink > 0.
1966          */
1967         J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
1968                   S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
1969
1970         BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access");
1971         err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
1972         if (err)
1973                 goto out_unlock;
1974
1975         err = ext4_reserve_inode_write(handle, inode, &iloc);
1976         if (err)
1977                 goto out_unlock;
1978
1979         /* Insert this inode at the head of the on-disk orphan list... */
1980         NEXT_ORPHAN(inode) = le32_to_cpu(EXT4_SB(sb)->s_es->s_last_orphan);
1981         EXT4_SB(sb)->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
1982         err = ext4_handle_dirty_metadata(handle, inode, EXT4_SB(sb)->s_sbh);
1983         rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
1984         if (!err)
1985                 err = rc;
1986
1987         /* Only add to the head of the in-memory list if all the
1988          * previous operations succeeded.  If the orphan_add is going to
1989          * fail (possibly taking the journal offline), we can't risk
1990          * leaving the inode on the orphan list: stray orphan-list
1991          * entries can cause panics at unmount time.
1992          *
1993          * This is safe: on error we're going to ignore the orphan list
1994          * anyway on the next recovery. */
1995         if (!err)
1996                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
1997
1998         jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
1999         jbd_debug(4, "orphan inode %lu will point to %d\n",
2000                         inode->i_ino, NEXT_ORPHAN(inode));
2001 out_unlock:
2002         unlock_super(sb);
2003         ext4_std_error(inode->i_sb, err);
2004         return err;
2005 }
2006
2007 /*
2008  * ext4_orphan_del() removes an unlinked or truncated inode from the list
2009  * of such inodes stored on disk, because it is finally being cleaned up.
2010  */
2011 int ext4_orphan_del(handle_t *handle, struct inode *inode)
2012 {
2013         struct list_head *prev;
2014         struct ext4_inode_info *ei = EXT4_I(inode);
2015         struct ext4_sb_info *sbi;
2016         __u32 ino_next;
2017         struct ext4_iloc iloc;
2018         int err = 0;
2019
2020         if (!ext4_handle_valid(handle))
2021                 return 0;
2022
2023         lock_super(inode->i_sb);
2024         if (list_empty(&ei->i_orphan)) {
2025                 unlock_super(inode->i_sb);
2026                 return 0;
2027         }
2028
2029         ino_next = NEXT_ORPHAN(inode);
2030         prev = ei->i_orphan.prev;
2031         sbi = EXT4_SB(inode->i_sb);
2032
2033         jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
2034
2035         list_del_init(&ei->i_orphan);
2036
2037         /* If we're on an error path, we may not have a valid
2038          * transaction handle with which to update the orphan list on
2039          * disk, but we still need to remove the inode from the linked
2040          * list in memory. */
2041         if (sbi->s_journal && !handle)
2042                 goto out;
2043
2044         err = ext4_reserve_inode_write(handle, inode, &iloc);
2045         if (err)
2046                 goto out_err;
2047
2048         if (prev == &sbi->s_orphan) {
2049                 jbd_debug(4, "superblock will point to %u\n", ino_next);
2050                 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2051                 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2052                 if (err)
2053                         goto out_brelse;
2054                 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
2055                 err = ext4_handle_dirty_metadata(handle, inode, sbi->s_sbh);
2056         } else {
2057                 struct ext4_iloc iloc2;
2058                 struct inode *i_prev =
2059                         &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
2060
2061                 jbd_debug(4, "orphan inode %lu will point to %u\n",
2062                           i_prev->i_ino, ino_next);
2063                 err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
2064                 if (err)
2065                         goto out_brelse;
2066                 NEXT_ORPHAN(i_prev) = ino_next;
2067                 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
2068         }
2069         if (err)
2070                 goto out_brelse;
2071         NEXT_ORPHAN(inode) = 0;
2072         err = ext4_mark_iloc_dirty(handle, inode, &iloc);
2073
2074 out_err:
2075         ext4_std_error(inode->i_sb, err);
2076 out:
2077         unlock_super(inode->i_sb);
2078         return err;
2079
2080 out_brelse:
2081         brelse(iloc.bh);
2082         goto out_err;
2083 }
2084
2085 static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
2086 {
2087         int retval;
2088         struct inode *inode;
2089         struct buffer_head *bh;
2090         struct ext4_dir_entry_2 *de;
2091         handle_t *handle;
2092
2093         /* Initialize quotas before so that eventual writes go in
2094          * separate transaction */
2095         vfs_dq_init(dentry->d_inode);
2096         handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb));
2097         if (IS_ERR(handle))
2098                 return PTR_ERR(handle);
2099
2100         retval = -ENOENT;
2101         bh = ext4_find_entry(dir, &dentry->d_name, &de);
2102         if (!bh)
2103                 goto end_rmdir;
2104
2105         if (IS_DIRSYNC(dir))
2106                 ext4_handle_sync(handle);
2107
2108         inode = dentry->d_inode;
2109
2110         retval = -EIO;
2111         if (le32_to_cpu(de->inode) != inode->i_ino)
2112                 goto end_rmdir;
2113
2114         retval = -ENOTEMPTY;
2115         if (!empty_dir(inode))
2116                 goto end_rmdir;
2117
2118         retval = ext4_delete_entry(handle, dir, de, bh);
2119         if (retval)
2120                 goto end_rmdir;
2121         if (!EXT4_DIR_LINK_EMPTY(inode))
2122                 ext4_warning(inode->i_sb, "ext4_rmdir",
2123                              "empty directory has too many links (%d)",
2124                              inode->i_nlink);
2125         inode->i_version++;
2126         clear_nlink(inode);
2127         /* There's no need to set i_disksize: the fact that i_nlink is
2128          * zero will ensure that the right thing happens during any
2129          * recovery. */
2130         inode->i_size = 0;
2131         ext4_orphan_add(handle, inode);
2132         inode->i_ctime = dir->i_ctime = dir->i_mtime = ext4_current_time(inode);
2133         ext4_mark_inode_dirty(handle, inode);
2134         ext4_dec_count(handle, dir);
2135         ext4_update_dx_flag(dir);
2136         ext4_mark_inode_dirty(handle, dir);
2137
2138 end_rmdir:
2139         ext4_journal_stop(handle);
2140         brelse(bh);
2141         return retval;
2142 }
2143
2144 static int ext4_unlink(struct inode *dir, struct dentry *dentry)
2145 {
2146         int retval;
2147         struct inode *inode;
2148         struct buffer_head *bh;
2149         struct ext4_dir_entry_2 *de;
2150         handle_t *handle;
2151
2152         /* Initialize quotas before so that eventual writes go
2153          * in separate transaction */
2154         vfs_dq_init(dentry->d_inode);
2155         handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb));
2156         if (IS_ERR(handle))
2157                 return PTR_ERR(handle);
2158
2159         if (IS_DIRSYNC(dir))
2160                 ext4_handle_sync(handle);
2161
2162         retval = -ENOENT;
2163         bh = ext4_find_entry(dir, &dentry->d_name, &de);
2164         if (!bh)
2165                 goto end_unlink;
2166
2167         inode = dentry->d_inode;
2168
2169         retval = -EIO;
2170         if (le32_to_cpu(de->inode) != inode->i_ino)
2171                 goto end_unlink;
2172
2173         if (!inode->i_nlink) {
2174                 ext4_warning(inode->i_sb, "ext4_unlink",
2175                              "Deleting nonexistent file (%lu), %d",
2176                              inode->i_ino, inode->i_nlink);
2177                 inode->i_nlink = 1;
2178         }
2179         retval = ext4_delete_entry(handle, dir, de, bh);
2180         if (retval)
2181                 goto end_unlink;
2182         dir->i_ctime = dir->i_mtime = ext4_current_time(dir);
2183         ext4_update_dx_flag(dir);
2184         ext4_mark_inode_dirty(handle, dir);
2185         drop_nlink(inode);
2186         if (!inode->i_nlink)
2187                 ext4_orphan_add(handle, inode);
2188         inode->i_ctime = ext4_current_time(inode);
2189         ext4_mark_inode_dirty(handle, inode);
2190         retval = 0;
2191
2192 end_unlink:
2193         ext4_journal_stop(handle);
2194         brelse(bh);
2195         return retval;
2196 }
2197
2198 static int ext4_symlink(struct inode *dir,
2199                         struct dentry *dentry, const char *symname)
2200 {
2201         handle_t *handle;
2202         struct inode *inode;
2203         int l, err, retries = 0;
2204
2205         l = strlen(symname)+1;
2206         if (l > dir->i_sb->s_blocksize)
2207                 return -ENAMETOOLONG;
2208
2209 retry:
2210         handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2211                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS + 5 +
2212                                         2*EXT4_QUOTA_INIT_BLOCKS(dir->i_sb));
2213         if (IS_ERR(handle))
2214                 return PTR_ERR(handle);
2215
2216         if (IS_DIRSYNC(dir))
2217                 ext4_handle_sync(handle);
2218
2219         inode = ext4_new_inode(handle, dir, S_IFLNK|S_IRWXUGO);
2220         err = PTR_ERR(inode);
2221         if (IS_ERR(inode))
2222                 goto out_stop;
2223
2224         if (l > sizeof(EXT4_I(inode)->i_data)) {
2225                 inode->i_op = &ext4_symlink_inode_operations;
2226                 ext4_set_aops(inode);
2227                 /*
2228                  * page_symlink() calls into ext4_prepare/commit_write.
2229                  * We have a transaction open.  All is sweetness.  It also sets
2230                  * i_size in generic_commit_write().
2231                  */
2232                 err = __page_symlink(inode, symname, l, 1);
2233                 if (err) {
2234                         clear_nlink(inode);
2235                         unlock_new_inode(inode);
2236                         ext4_mark_inode_dirty(handle, inode);
2237                         iput(inode);
2238                         goto out_stop;
2239                 }
2240         } else {
2241                 /* clear the extent format for fast symlink */
2242                 EXT4_I(inode)->i_flags &= ~EXT4_EXTENTS_FL;
2243                 inode->i_op = &ext4_fast_symlink_inode_operations;
2244                 memcpy((char *)&EXT4_I(inode)->i_data, symname, l);
2245                 inode->i_size = l-1;
2246         }
2247         EXT4_I(inode)->i_disksize = inode->i_size;
2248         err = ext4_add_nondir(handle, dentry, inode);
2249 out_stop:
2250         ext4_journal_stop(handle);
2251         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2252                 goto retry;
2253         return err;
2254 }
2255
2256 static int ext4_link(struct dentry *old_dentry,
2257                      struct inode *dir, struct dentry *dentry)
2258 {
2259         handle_t *handle;
2260         struct inode *inode = old_dentry->d_inode;
2261         int err, retries = 0;
2262
2263         if (EXT4_DIR_LINK_MAX(inode))
2264                 return -EMLINK;
2265
2266         /*
2267          * Return -ENOENT if we've raced with unlink and i_nlink is 0.  Doing
2268          * otherwise has the potential to corrupt the orphan inode list.
2269          */
2270         if (inode->i_nlink == 0)
2271                 return -ENOENT;
2272
2273 retry:
2274         handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2275                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS);
2276         if (IS_ERR(handle))
2277                 return PTR_ERR(handle);
2278
2279         if (IS_DIRSYNC(dir))
2280                 ext4_handle_sync(handle);
2281
2282         inode->i_ctime = ext4_current_time(inode);
2283         ext4_inc_count(handle, inode);
2284         atomic_inc(&inode->i_count);
2285
2286         err = ext4_add_entry(handle, dentry, inode);
2287         if (!err) {
2288                 ext4_mark_inode_dirty(handle, inode);
2289                 d_instantiate(dentry, inode);
2290         } else {
2291                 drop_nlink(inode);
2292                 iput(inode);
2293         }
2294         ext4_journal_stop(handle);
2295         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2296                 goto retry;
2297         return err;
2298 }
2299
2300 #define PARENT_INO(buffer) \
2301         (ext4_next_entry((struct ext4_dir_entry_2 *)(buffer))->inode)
2302
2303 /*
2304  * Anybody can rename anything with this: the permission checks are left to the
2305  * higher-level routines.
2306  */
2307 static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
2308                        struct inode *new_dir, struct dentry *new_dentry)
2309 {
2310         handle_t *handle;
2311         struct inode *old_inode, *new_inode;
2312         struct buffer_head *old_bh, *new_bh, *dir_bh;
2313         struct ext4_dir_entry_2 *old_de, *new_de;
2314         int retval;
2315
2316         old_bh = new_bh = dir_bh = NULL;
2317
2318         /* Initialize quotas before so that eventual writes go
2319          * in separate transaction */
2320         if (new_dentry->d_inode)
2321                 vfs_dq_init(new_dentry->d_inode);
2322         handle = ext4_journal_start(old_dir, 2 *
2323                                         EXT4_DATA_TRANS_BLOCKS(old_dir->i_sb) +
2324                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
2325         if (IS_ERR(handle))
2326                 return PTR_ERR(handle);
2327
2328         if (IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir))
2329                 ext4_handle_sync(handle);
2330
2331         old_bh = ext4_find_entry(old_dir, &old_dentry->d_name, &old_de);
2332         /*
2333          *  Check for inode number is _not_ due to possible IO errors.
2334          *  We might rmdir the source, keep it as pwd of some process
2335          *  and merrily kill the link to whatever was created under the
2336          *  same name. Goodbye sticky bit ;-<
2337          */
2338         old_inode = old_dentry->d_inode;
2339         retval = -ENOENT;
2340         if (!old_bh || le32_to_cpu(old_de->inode) != old_inode->i_ino)
2341                 goto end_rename;
2342
2343         new_inode = new_dentry->d_inode;
2344         new_bh = ext4_find_entry(new_dir, &new_dentry->d_name, &new_de);
2345         if (new_bh) {
2346                 if (!new_inode) {
2347                         brelse(new_bh);
2348                         new_bh = NULL;
2349                 }
2350         }
2351         if (S_ISDIR(old_inode->i_mode)) {
2352                 if (new_inode) {
2353                         retval = -ENOTEMPTY;
2354                         if (!empty_dir(new_inode))
2355                                 goto end_rename;
2356                 }
2357                 retval = -EIO;
2358                 dir_bh = ext4_bread(handle, old_inode, 0, 0, &retval);
2359                 if (!dir_bh)
2360                         goto end_rename;
2361                 if (le32_to_cpu(PARENT_INO(dir_bh->b_data)) != old_dir->i_ino)
2362                         goto end_rename;
2363                 retval = -EMLINK;
2364                 if (!new_inode && new_dir != old_dir &&
2365                                 new_dir->i_nlink >= EXT4_LINK_MAX)
2366                         goto end_rename;
2367         }
2368         if (!new_bh) {
2369                 retval = ext4_add_entry(handle, new_dentry, old_inode);
2370                 if (retval)
2371                         goto end_rename;
2372         } else {
2373                 BUFFER_TRACE(new_bh, "get write access");
2374                 ext4_journal_get_write_access(handle, new_bh);
2375                 new_de->inode = cpu_to_le32(old_inode->i_ino);
2376                 if (EXT4_HAS_INCOMPAT_FEATURE(new_dir->i_sb,
2377                                               EXT4_FEATURE_INCOMPAT_FILETYPE))
2378                         new_de->file_type = old_de->file_type;
2379                 new_dir->i_version++;
2380                 new_dir->i_ctime = new_dir->i_mtime =
2381                                         ext4_current_time(new_dir);
2382                 ext4_mark_inode_dirty(handle, new_dir);
2383                 BUFFER_TRACE(new_bh, "call ext4_handle_dirty_metadata");
2384                 ext4_handle_dirty_metadata(handle, new_dir, new_bh);
2385                 brelse(new_bh);
2386                 new_bh = NULL;
2387         }
2388
2389         /*
2390          * Like most other Unix systems, set the ctime for inodes on a
2391          * rename.
2392          */
2393         old_inode->i_ctime = ext4_current_time(old_inode);
2394         ext4_mark_inode_dirty(handle, old_inode);
2395
2396         /*
2397          * ok, that's it
2398          */
2399         if (le32_to_cpu(old_de->inode) != old_inode->i_ino ||
2400             old_de->name_len != old_dentry->d_name.len ||
2401             strncmp(old_de->name, old_dentry->d_name.name, old_de->name_len) ||
2402             (retval = ext4_delete_entry(handle, old_dir,
2403                                         old_de, old_bh)) == -ENOENT) {
2404                 /* old_de could have moved from under us during htree split, so
2405                  * make sure that we are deleting the right entry.  We might
2406                  * also be pointing to a stale entry in the unused part of
2407                  * old_bh so just checking inum and the name isn't enough. */
2408                 struct buffer_head *old_bh2;
2409                 struct ext4_dir_entry_2 *old_de2;
2410
2411                 old_bh2 = ext4_find_entry(old_dir, &old_dentry->d_name, &old_de2);
2412                 if (old_bh2) {
2413                         retval = ext4_delete_entry(handle, old_dir,
2414                                                    old_de2, old_bh2);
2415                         brelse(old_bh2);
2416                 }
2417         }
2418         if (retval) {
2419                 ext4_warning(old_dir->i_sb, "ext4_rename",
2420                                 "Deleting old file (%lu), %d, error=%d",
2421                                 old_dir->i_ino, old_dir->i_nlink, retval);
2422         }
2423
2424         if (new_inode) {
2425                 ext4_dec_count(handle, new_inode);
2426                 new_inode->i_ctime = ext4_current_time(new_inode);
2427         }
2428         old_dir->i_ctime = old_dir->i_mtime = ext4_current_time(old_dir);
2429         ext4_update_dx_flag(old_dir);
2430         if (dir_bh) {
2431                 BUFFER_TRACE(dir_bh, "get_write_access");
2432                 ext4_journal_get_write_access(handle, dir_bh);
2433                 PARENT_INO(dir_bh->b_data) = cpu_to_le32(new_dir->i_ino);
2434                 BUFFER_TRACE(dir_bh, "call ext4_handle_dirty_metadata");
2435                 ext4_handle_dirty_metadata(handle, old_dir, dir_bh);
2436                 ext4_dec_count(handle, old_dir);
2437                 if (new_inode) {
2438                         /* checked empty_dir above, can't have another parent,
2439                          * ext4_dec_count() won't work for many-linked dirs */
2440                         new_inode->i_nlink = 0;
2441                 } else {
2442                         ext4_inc_count(handle, new_dir);
2443                         ext4_update_dx_flag(new_dir);
2444                         ext4_mark_inode_dirty(handle, new_dir);
2445                 }
2446         }
2447         ext4_mark_inode_dirty(handle, old_dir);
2448         if (new_inode) {
2449                 ext4_mark_inode_dirty(handle, new_inode);
2450                 if (!new_inode->i_nlink)
2451                         ext4_orphan_add(handle, new_inode);
2452         }
2453         retval = 0;
2454
2455 end_rename:
2456         brelse(dir_bh);
2457         brelse(old_bh);
2458         brelse(new_bh);
2459         ext4_journal_stop(handle);
2460         return retval;
2461 }
2462
2463 /*
2464  * directories can handle most operations...
2465  */
2466 const struct inode_operations ext4_dir_inode_operations = {
2467         .create         = ext4_create,
2468         .lookup         = ext4_lookup,
2469         .link           = ext4_link,
2470         .unlink         = ext4_unlink,
2471         .symlink        = ext4_symlink,
2472         .mkdir          = ext4_mkdir,
2473         .rmdir          = ext4_rmdir,
2474         .mknod          = ext4_mknod,
2475         .rename         = ext4_rename,
2476         .setattr        = ext4_setattr,
2477 #ifdef CONFIG_EXT4_FS_XATTR
2478         .setxattr       = generic_setxattr,
2479         .getxattr       = generic_getxattr,
2480         .listxattr      = ext4_listxattr,
2481         .removexattr    = generic_removexattr,
2482 #endif
2483         .permission     = ext4_permission,
2484 };
2485
2486 const struct inode_operations ext4_special_inode_operations = {
2487         .setattr        = ext4_setattr,
2488 #ifdef CONFIG_EXT4_FS_XATTR
2489         .setxattr       = generic_setxattr,
2490         .getxattr       = generic_getxattr,
2491         .listxattr      = ext4_listxattr,
2492         .removexattr    = generic_removexattr,
2493 #endif
2494         .permission     = ext4_permission,
2495 };