fs/ext3/xattr.c

   1 /*
   2  * linux/fs/ext3/xattr.c
   3  *
   4  * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
   5  *
   6  * Fix by Harrison Xing <harrison@mountainviewdata.com>.
   7  * Ext3 code with a lot of help from Eric Jarman <ejarman@acm.org>.
   8  * Extended attributes for symlinks and special files added per
   9  *  suggestion of Luka Renko <luka.renko@hermes.si>.
  10  */
  11
  12 /*
  13  * Extended attributes are stored on disk blocks allocated outside of
  14  * any inode. The i_file_acl field is then made to point to this allocated
  15  * block. If all extended attributes of an inode are identical, these
  16  * inodes may share the same extended attribute block. Such situations
  17  * are automatically detected by keeping a cache of recent attribute block
  18  * numbers and hashes over the block's contents in memory.
  19  *
  20  *
  21  * Extended attribute block layout:
  22  *
  23  *   +------------------+
  24  *   | header           |
  25  *   ¦ entry 1          | |
  26  *   | entry 2          | | growing downwards
  27  *   | entry 3          | v
  28  *   | four null bytes  |
  29  *   | . . .            |
  30  *   | value 1          | ^
  31  *   | value 3          | | growing upwards
  32  *   | value 2          | |
  33  *   +------------------+
  34  *
  35  * The block header is followed by multiple entry descriptors. These entry
  36  * descriptors are variable in size, and alligned to EXT3_XATTR_PAD
  37  * byte boundaries. The entry descriptors are sorted by attribute name,
  38  * so that two extended attribute blocks can be compared efficiently.
  39  *
  40  * Attribute values are aligned to the end of the block, stored in
  41  * no specific order. They are also padded to EXT3_XATTR_PAD byte
  42  * boundaries. No additional gaps are left between them.
  43  *
  44  * Locking strategy
  45  * ----------------
  46  * EXT3_I(inode)->i_file_acl is protected by EXT3_I(inode)->xattr_sem.
  47  * EA blocks are only changed if they are exclusive to an inode, so
  48  * holding xattr_sem also means that nothing but the EA block's reference
  49  * count will change. Multiple writers to an EA block are synchronized
  50  * by the bh lock. No more than a single bh lock is held at any time
  51  * to avoid deadlocks.
  52  */
  53
  54 #include <linux/init.h>
  55 #include <linux/fs.h>
  56 #include <linux/slab.h>
  57 #include <linux/ext3_jbd.h>
  58 #include <linux/ext3_fs.h>
  59 #include <linux/mbcache.h>
  60 #include <linux/quotaops.h>
  61 #include <linux/rwsem.h>
  62 #include "xattr.h"
  63 #include "acl.h"
  64
  65 #define HDR(bh) ((struct ext3_xattr_header *)((bh)->b_data))
  66 #define ENTRY(ptr) ((struct ext3_xattr_entry *)(ptr))
  67 #define FIRST_ENTRY(bh) ENTRY(HDR(bh)+1)
  68 #define IS_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0)
  69
  70 #ifdef EXT3_XATTR_DEBUG
  71 # define ea_idebug(inode, f...) do { \
  72                 printk(KERN_DEBUG "inode %s:%ld: ", \
  73                         inode->i_sb->s_id, inode->i_ino); \
  74                 printk(f); \
  75                 printk("\n"); \
  76         } while (0)
  77 # define ea_bdebug(bh, f...) do { \
  78                 char b[BDEVNAME_SIZE]; \
  79                 printk(KERN_DEBUG "block %s:%lu: ", \
  80                         bdevname(bh->b_bdev, b), \
  81                         (unsigned long) bh->b_blocknr); \
  82                 printk(f); \
  83                 printk("\n"); \
  84         } while (0)
  85 #else
  86 # define ea_idebug(f...)
  87 # define ea_bdebug(f...)
  88 #endif
  89
  90 static int ext3_xattr_set_handle2(handle_t *, struct inode *,
  91                                   struct buffer_head *,
  92                                   struct ext3_xattr_header *);
  93
  94 static int ext3_xattr_cache_insert(struct buffer_head *);
  95 static struct buffer_head *ext3_xattr_cache_find(handle_t *, struct inode *,
  96                                                  struct ext3_xattr_header *,
  97                                                  int *);
  98 static void ext3_xattr_cache_remove(struct buffer_head *);
  99 static void ext3_xattr_rehash(struct ext3_xattr_header *,
 100                               struct ext3_xattr_entry *);
 101
 102 static struct mb_cache *ext3_xattr_cache;
 103 static struct ext3_xattr_handler *ext3_xattr_handlers[EXT3_XATTR_INDEX_MAX];
 104 static rwlock_t ext3_handler_lock = RW_LOCK_UNLOCKED;
 105
 106 int
 107 ext3_xattr_register(int name_index, struct ext3_xattr_handler *handler)
 108 {
 109         int error = -EINVAL;
 110
 111         if (name_index > 0 && name_index <= EXT3_XATTR_INDEX_MAX) {
 112                 write_lock(&ext3_handler_lock);
 113                 if (!ext3_xattr_handlers[name_index-1]) {
 114                         ext3_xattr_handlers[name_index-1] = handler;
 115                         error = 0;
 116                 }
 117                 write_unlock(&ext3_handler_lock);
 118         }
 119         return error;
 120 }
 121
 122 void
 123 ext3_xattr_unregister(int name_index, struct ext3_xattr_handler *handler)
 124 {
 125         if (name_index > 0 || name_index <= EXT3_XATTR_INDEX_MAX) {
 126                 write_lock(&ext3_handler_lock);
 127                 ext3_xattr_handlers[name_index-1] = NULL;
 128                 write_unlock(&ext3_handler_lock);
 129         }
 130 }
 131
 132 static inline const char *
 133 strcmp_prefix(const char *a, const char *a_prefix)
 134 {
 135         while (*a_prefix && *a == *a_prefix) {
 136                 a++;
 137                 a_prefix++;
 138         }
 139         return *a_prefix ? NULL : a;
 140 }
 141
 142 /*
 143  * Decode the extended attribute name, and translate it into
 144  * the name_index and name suffix.
 145  */
 146 static inline struct ext3_xattr_handler *
 147 ext3_xattr_resolve_name(const char **name)
 148 {
 149         struct ext3_xattr_handler *handler = NULL;
 150         int i;
 151
 152         if (!*name)
 153                 return NULL;
 154         read_lock(&ext3_handler_lock);
 155         for (i=0; i<EXT3_XATTR_INDEX_MAX; i++) {
 156                 if (ext3_xattr_handlers[i]) {
 157                         const char *n = strcmp_prefix(*name,
 158                                 ext3_xattr_handlers[i]->prefix);
 159                         if (n) {
 160                                 handler = ext3_xattr_handlers[i];
 161                                 *name = n;
 162                                 break;
 163                         }
 164                 }
 165         }
 166         read_unlock(&ext3_handler_lock);
 167         return handler;
 168 }
 169
 170 static inline struct ext3_xattr_handler *
 171 ext3_xattr_handler(int name_index)
 172 {
 173         struct ext3_xattr_handler *handler = NULL;
 174         if (name_index > 0 && name_index <= EXT3_XATTR_INDEX_MAX) {
 175                 read_lock(&ext3_handler_lock);
 176                 handler = ext3_xattr_handlers[name_index-1];
 177                 read_unlock(&ext3_handler_lock);
 178         }
 179         return handler;
 180 }
 181
 182 /*
 183  * Inode operation getxattr()
 184  *
 185  * dentry->d_inode->i_sem: don't care
 186  */
 187 ssize_t
 188 ext3_getxattr(struct dentry *dentry, const char *name,
 189               void *buffer, size_t size)
 190 {
 191         struct ext3_xattr_handler *handler;
 192         struct inode *inode = dentry->d_inode;
 193
 194         handler = ext3_xattr_resolve_name(&name);
 195         if (!handler)
 196                 return -EOPNOTSUPP;
 197         return handler->get(inode, name, buffer, size);
 198 }
 199
 200 /*
 201  * Inode operation listxattr()
 202  *
 203  * dentry->d_inode->i_sem: don't care
 204  */
 205 ssize_t
 206 ext3_listxattr(struct dentry *dentry, char *buffer, size_t size)
 207 {
 208         return ext3_xattr_list(dentry->d_inode, buffer, size);
 209 }
 210
 211 /*
 212  * Inode operation setxattr()
 213  *
 214  * dentry->d_inode->i_sem: down
 215  */
 216 int
 217 ext3_setxattr(struct dentry *dentry, const char *name,
 218               const void *value, size_t size, int flags)
 219 {
 220         struct ext3_xattr_handler *handler;
 221         struct inode *inode = dentry->d_inode;
 222
 223         if (size == 0)
 224                 value = "";  /* empty EA, do not remove */
 225         handler = ext3_xattr_resolve_name(&name);
 226         if (!handler)
 227                 return -EOPNOTSUPP;
 228         return handler->set(inode, name, value, size, flags);
 229 }
 230
 231 /*
 232  * Inode operation removexattr()
 233  *
 234  * dentry->d_inode->i_sem: down
 235  */
 236 int
 237 ext3_removexattr(struct dentry *dentry, const char *name)
 238 {
 239         struct ext3_xattr_handler *handler;
 240         struct inode *inode = dentry->d_inode;
 241
 242         handler = ext3_xattr_resolve_name(&name);
 243         if (!handler)
 244                 return -EOPNOTSUPP;
 245         return handler->set(inode, name, NULL, 0, XATTR_REPLACE);
 246 }
 247
 248 /*
 249  * ext3_xattr_get()
 250  *
 251  * Copy an extended attribute into the buffer
 252  * provided, or compute the buffer size required.
 253  * Buffer is NULL to compute the size of the buffer required.
 254  *
 255  * Returns a negative error number on failure, or the number of bytes
 256  * used / required on success.
 257  */
 258 int
 259 ext3_xattr_get(struct inode *inode, int name_index, const char *name,
 260                void *buffer, size_t buffer_size)
 261 {
 262         struct buffer_head *bh = NULL;
 263         struct ext3_xattr_entry *entry;
 264         size_t name_len, size;
 265         char *end;
 266         int error;
 267
 268         ea_idebug(inode, "name=%d.%s, buffer=%p, buffer_size=%ld",
 269                   name_index, name, buffer, (long)buffer_size);
 270
 271         if (name == NULL)
 272                 return -EINVAL;
 273         down_read(&EXT3_I(inode)->xattr_sem);
 274         error = -ENODATA;
 275         if (!EXT3_I(inode)->i_file_acl)
 276                 goto cleanup;
 277         ea_idebug(inode, "reading block %d", EXT3_I(inode)->i_file_acl);
 278         bh = sb_bread(inode->i_sb, EXT3_I(inode)->i_file_acl);
 279         error = -EIO;
 280         if (!bh)
 281                 goto cleanup;
 282         ea_bdebug(bh, "b_count=%d, refcount=%d",
 283                 atomic_read(&(bh->b_count)), le32_to_cpu(HDR(bh)->h_refcount));
 284         end = bh->b_data + bh->b_size;
 285         if (HDR(bh)->h_magic != cpu_to_le32(EXT3_XATTR_MAGIC) ||
 286             HDR(bh)->h_blocks != cpu_to_le32(1)) {
 287 bad_block:      ext3_error(inode->i_sb, "ext3_xattr_get",
 288                         "inode %ld: bad block %d", inode->i_ino,
 289                         EXT3_I(inode)->i_file_acl);
 290                 error = -EIO;
 291                 goto cleanup;
 292         }
 293         /* find named attribute */
 294         name_len = strlen(name);
 295
 296         error = -ERANGE;
 297         if (name_len > 255)
 298                 goto cleanup;
 299         entry = FIRST_ENTRY(bh);
 300         while (!IS_LAST_ENTRY(entry)) {
 301                 struct ext3_xattr_entry *next =
 302                         EXT3_XATTR_NEXT(entry);
 303                 if ((char *)next >= end)
 304                         goto bad_block;
 305                 if (name_index == entry->e_name_index &&
 306                     name_len == entry->e_name_len &&
 307                     memcmp(name, entry->e_name, name_len) == 0)
 308                         goto found;
 309                 entry = next;
 310         }
 311         /* Check the remaining name entries */
 312         while (!IS_LAST_ENTRY(entry)) {
 313                 struct ext3_xattr_entry *next =
 314                         EXT3_XATTR_NEXT(entry);
 315                 if ((char *)next >= end)
 316                         goto bad_block;
 317                 entry = next;
 318         }
 319         if (ext3_xattr_cache_insert(bh))
 320                 ea_idebug(inode, "cache insert failed");
 321         error = -ENODATA;
 322         goto cleanup;
 323 found:
 324         /* check the buffer size */
 325         if (entry->e_value_block != 0)
 326                 goto bad_block;
 327         size = le32_to_cpu(entry->e_value_size);
 328         if (size > inode->i_sb->s_blocksize ||
 329             le16_to_cpu(entry->e_value_offs) + size > inode->i_sb->s_blocksize)
 330                 goto bad_block;
 331
 332         if (ext3_xattr_cache_insert(bh))
 333                 ea_idebug(inode, "cache insert failed");
 334         if (buffer) {
 335                 error = -ERANGE;
 336                 if (size > buffer_size)
 337                         goto cleanup;
 338                 /* return value of attribute */
 339                 memcpy(buffer, bh->b_data + le16_to_cpu(entry->e_value_offs),
 340                         size);
 341         }
 342         error = size;
 343
 344 cleanup:
 345         brelse(bh);
 346         up_read(&EXT3_I(inode)->xattr_sem);
 347
 348         return error;
 349 }
 350
 351 /*
 352  * ext3_xattr_list()
 353  *
 354  * Copy a list of attribute names into the buffer
 355  * provided, or compute the buffer size required.
 356  * Buffer is NULL to compute the size of the buffer required.
 357  *
 358  * Returns a negative error number on failure, or the number of bytes
 359  * used / required on success.
 360  */
 361 int
 362 ext3_xattr_list(struct inode *inode, char *buffer, size_t buffer_size)
 363 {
 364         struct buffer_head *bh = NULL;
 365         struct ext3_xattr_entry *entry;
 366         size_t size = 0;
 367         char *buf, *end;
 368         int error;
 369
 370         ea_idebug(inode, "buffer=%p, buffer_size=%ld",
 371                   buffer, (long)buffer_size);
 372
 373         down_read(&EXT3_I(inode)->xattr_sem);
 374         error = 0;
 375         if (!EXT3_I(inode)->i_file_acl)
 376                 goto cleanup;
 377         ea_idebug(inode, "reading block %d", EXT3_I(inode)->i_file_acl);
 378         bh = sb_bread(inode->i_sb, EXT3_I(inode)->i_file_acl);
 379         error = -EIO;
 380         if (!bh)
 381                 goto cleanup;
 382         ea_bdebug(bh, "b_count=%d, refcount=%d",
 383                 atomic_read(&(bh->b_count)), le32_to_cpu(HDR(bh)->h_refcount));
 384         end = bh->b_data + bh->b_size;
 385         if (HDR(bh)->h_magic != cpu_to_le32(EXT3_XATTR_MAGIC) ||
 386             HDR(bh)->h_blocks != cpu_to_le32(1)) {
 387 bad_block:      ext3_error(inode->i_sb, "ext3_xattr_list",
 388                         "inode %ld: bad block %d", inode->i_ino,
 389                         EXT3_I(inode)->i_file_acl);
 390                 error = -EIO;
 391                 goto cleanup;
 392         }
 393         /* compute the size required for the list of attribute names */
 394         for (entry = FIRST_ENTRY(bh); !IS_LAST_ENTRY(entry);
 395              entry = EXT3_XATTR_NEXT(entry)) {
 396                 struct ext3_xattr_handler *handler;
 397                 struct ext3_xattr_entry *next =
 398                         EXT3_XATTR_NEXT(entry);
 399                 if ((char *)next >= end)
 400                         goto bad_block;
 401
 402                 handler = ext3_xattr_handler(entry->e_name_index);
 403                 if (handler)
 404                         size += handler->list(NULL, inode, entry->e_name,
 405                                               entry->e_name_len);
 406         }
 407
 408         if (ext3_xattr_cache_insert(bh))
 409                 ea_idebug(inode, "cache insert failed");
 410         if (!buffer) {
 411                 error = size;
 412                 goto cleanup;
 413         } else {
 414                 error = -ERANGE;
 415                 if (size > buffer_size)
 416                         goto cleanup;
 417         }
 418
 419         /* list the attribute names */
 420         buf = buffer;
 421         for (entry = FIRST_ENTRY(bh); !IS_LAST_ENTRY(entry);
 422              entry = EXT3_XATTR_NEXT(entry)) {
 423                 struct ext3_xattr_handler *handler;
 424
 425                 handler = ext3_xattr_handler(entry->e_name_index);
 426                 if (handler)
 427                         buf += handler->list(buf, inode, entry->e_name,
 428                                              entry->e_name_len);
 429         }
 430         error = size;
 431
 432 cleanup:
 433         brelse(bh);
 434         up_read(&EXT3_I(inode)->xattr_sem);
 435
 436         return error;
 437 }
 438
 439 /*
 440  * If the EXT3_FEATURE_COMPAT_EXT_ATTR feature of this file system is
 441  * not set, set it.
 442  */
 443 static void ext3_xattr_update_super_block(handle_t *handle,
 444                                           struct super_block *sb)
 445 {
 446         if (EXT3_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_EXT_ATTR))
 447                 return;
 448
 449         lock_super(sb);
 450         if (ext3_journal_get_write_access(handle, EXT3_SB(sb)->s_sbh) == 0) {
 451                 EXT3_SB(sb)->s_es->s_feature_compat |=
 452                         cpu_to_le32(EXT3_FEATURE_COMPAT_EXT_ATTR);
 453                 sb->s_dirt = 1;
 454                 ext3_journal_dirty_metadata(handle, EXT3_SB(sb)->s_sbh);
 455         }
 456         unlock_super(sb);
 457 }
 458
 459 /*
 460  * ext3_xattr_set_handle()
 461  *
 462  * Create, replace or remove an extended attribute for this inode. Buffer
 463  * is NULL to remove an existing extended attribute, and non-NULL to
 464  * either replace an existing extended attribute, or create a new extended
 465  * attribute. The flags XATTR_REPLACE and XATTR_CREATE
 466  * specify that an extended attribute must exist and must not exist
 467  * previous to the call, respectively.
 468  *
 469  * Returns 0, or a negative error number on failure.
 470  */
 471 int
 472 ext3_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
 473                       const char *name, const void *value, size_t value_len,
 474                       int flags)
 475 {
 476         struct super_block *sb = inode->i_sb;
 477         struct buffer_head *bh = NULL;
 478         struct ext3_xattr_header *header = NULL;
 479         struct ext3_xattr_entry *here, *last;
 480         size_t name_len, free, min_offs = sb->s_blocksize;
 481         int not_found = 1, error;
 482         char *end;
 483
 484         /*
 485          * header -- Points either into bh, or to a temporarily
 486          *           allocated buffer.
 487          * here -- The named entry found, or the place for inserting, within
 488          *         the block pointed to by header.
 489          * last -- Points right after the last named entry within the block
 490          *         pointed to by header.
 491          * min_offs -- The offset of the first value (values are aligned
 492          *             towards the end of the block).
 493          * end -- Points right after the block pointed to by header.
 494          */
 495
 496         ea_idebug(inode, "name=%d.%s, value=%p, value_len=%ld",
 497                   name_index, name, value, (long)value_len);
 498
 499         if (IS_RDONLY(inode))
 500                 return -EROFS;
 501         if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
 502                 return -EPERM;
 503         if (value == NULL)
 504                 value_len = 0;
 505         if (name == NULL)
 506                 return -EINVAL;
 507         name_len = strlen(name);
 508         if (name_len > 255 || value_len > sb->s_blocksize)
 509                 return -ERANGE;
 510         down_write(&EXT3_I(inode)->xattr_sem);
 511         if (EXT3_I(inode)->i_file_acl) {
 512                 /* The inode already has an extended attribute block. */
 513                 bh = sb_bread(sb, EXT3_I(inode)->i_file_acl);
 514                 error = -EIO;
 515                 if (!bh)
 516                         goto cleanup;
 517                 ea_bdebug(bh, "b_count=%d, refcount=%d",
 518                         atomic_read(&(bh->b_count)),
 519                         le32_to_cpu(HDR(bh)->h_refcount));
 520                 header = HDR(bh);
 521                 end = bh->b_data + bh->b_size;
 522                 if (header->h_magic != cpu_to_le32(EXT3_XATTR_MAGIC) ||
 523                     header->h_blocks != cpu_to_le32(1)) {
 524 bad_block:              ext3_error(sb, "ext3_xattr_set",
 525                                 "inode %ld: bad block %d", inode->i_ino,
 526                                 EXT3_I(inode)->i_file_acl);
 527                         error = -EIO;
 528                         goto cleanup;
 529                 }
 530                 /* Find the named attribute. */
 531                 here = FIRST_ENTRY(bh);
 532                 while (!IS_LAST_ENTRY(here)) {
 533                         struct ext3_xattr_entry *next = EXT3_XATTR_NEXT(here);
 534                         if ((char *)next >= end)
 535                                 goto bad_block;
 536                         if (!here->e_value_block && here->e_value_size) {
 537                                 size_t offs = le16_to_cpu(here->e_value_offs);
 538                                 if (offs < min_offs)
 539                                         min_offs = offs;
 540                         }
 541                         not_found = name_index - here->e_name_index;
 542                         if (!not_found)
 543                                 not_found = name_len - here->e_name_len;
 544                         if (!not_found)
 545                                 not_found = memcmp(name, here->e_name,name_len);
 546                         if (not_found <= 0)
 547                                 break;
 548                         here = next;
 549                 }
 550                 last = here;
 551                 /* We still need to compute min_offs and last. */
 552                 while (!IS_LAST_ENTRY(last)) {
 553                         struct ext3_xattr_entry *next = EXT3_XATTR_NEXT(last);
 554                         if ((char *)next >= end)
 555                                 goto bad_block;
 556                         if (!last->e_value_block && last->e_value_size) {
 557                                 size_t offs = le16_to_cpu(last->e_value_offs);
 558                                 if (offs < min_offs)
 559                                         min_offs = offs;
 560                         }
 561                         last = next;
 562                 }
 563
 564                 /* Check whether we have enough space left. */
 565                 free = min_offs - ((char*)last - (char*)header) - sizeof(__u32);
 566         } else {
 567                 /* We will use a new extended attribute block. */
 568                 free = sb->s_blocksize -
 569                         sizeof(struct ext3_xattr_header) - sizeof(__u32);
 570                 here = last = NULL;  /* avoid gcc uninitialized warning. */
 571         }
 572
 573         if (not_found) {
 574                 /* Request to remove a nonexistent attribute? */
 575                 error = -ENODATA;
 576                 if (flags & XATTR_REPLACE)
 577                         goto cleanup;
 578                 error = 0;
 579                 if (value == NULL)
 580                         goto cleanup;
 581         } else {
 582                 /* Request to create an existing attribute? */
 583                 error = -EEXIST;
 584                 if (flags & XATTR_CREATE)
 585                         goto cleanup;
 586                 if (!here->e_value_block && here->e_value_size) {
 587                         size_t size = le32_to_cpu(here->e_value_size);
 588
 589                         if (le16_to_cpu(here->e_value_offs) + size >
 590                             sb->s_blocksize || size > sb->s_blocksize)
 591                                 goto bad_block;
 592                         free += EXT3_XATTR_SIZE(size);
 593                 }
 594                 free += EXT3_XATTR_LEN(name_len);
 595         }
 596         error = -ENOSPC;
 597         if (free < EXT3_XATTR_LEN(name_len) + EXT3_XATTR_SIZE(value_len))
 598                 goto cleanup;
 599
 600         /* Here we know that we can set the new attribute. */
 601
 602         if (header) {
 603                 int credits = 0;
 604
 605                 /* assert(header == HDR(bh)); */
 606                 if (header->h_refcount != cpu_to_le32(1))
 607                         goto skip_get_write_access;
 608                 /* ext3_journal_get_write_access() requires an unlocked bh,
 609                    which complicates things here. */
 610                 error = ext3_journal_get_write_access_credits(handle, bh,
 611                                                               &credits);
 612                 if (error)
 613                         goto cleanup;
 614                 lock_buffer(bh);
 615                 if (header->h_refcount == cpu_to_le32(1)) {
 616                         ea_bdebug(bh, "modifying in-place");
 617                         ext3_xattr_cache_remove(bh);
 618                         /* keep the buffer locked while modifying it. */
 619                 } else {
 620                         int offset;
 621
 622                         unlock_buffer(bh);
 623                         journal_release_buffer(handle, bh, credits);
 624                 skip_get_write_access:
 625                         ea_bdebug(bh, "cloning");
 626                         header = kmalloc(bh->b_size, GFP_KERNEL);
 627                         error = -ENOMEM;
 628                         if (header == NULL)
 629                                 goto cleanup;
 630                         memcpy(header, HDR(bh), bh->b_size);
 631                         header->h_refcount = cpu_to_le32(1);
 632                         offset = (char *)here - bh->b_data;
 633                         here = ENTRY((char *)header + offset);
 634                         offset = (char *)last - bh->b_data;
 635                         last = ENTRY((char *)header + offset);
 636                 }
 637         } else {
 638                 /* Allocate a buffer where we construct the new block. */
 639                 header = kmalloc(sb->s_blocksize, GFP_KERNEL);
 640                 error = -ENOMEM;
 641                 if (header == NULL)
 642                         goto cleanup;
 643                 memset(header, 0, sb->s_blocksize);
 644                 end = (char *)header + sb->s_blocksize;
 645                 header->h_magic = cpu_to_le32(EXT3_XATTR_MAGIC);
 646                 header->h_blocks = header->h_refcount = cpu_to_le32(1);
 647                 last = here = ENTRY(header+1);
 648         }
 649
 650         /* Iff we are modifying the block in-place, bh is locked here. */
 651
 652         if (not_found) {
 653                 /* Insert the new name. */
 654                 size_t size = EXT3_XATTR_LEN(name_len);
 655                 size_t rest = (char *)last - (char *)here;
 656                 memmove((char *)here + size, here, rest);
 657                 memset(here, 0, size);
 658                 here->e_name_index = name_index;
 659                 here->e_name_len = name_len;
 660                 memcpy(here->e_name, name, name_len);
 661         } else {
 662                 if (!here->e_value_block && here->e_value_size) {
 663                         char *first_val = (char *)header + min_offs;
 664                         size_t offs = le16_to_cpu(here->e_value_offs);
 665                         char *val = (char *)header + offs;
 666                         size_t size = EXT3_XATTR_SIZE(
 667                                 le32_to_cpu(here->e_value_size));
 668
 669                         if (size == EXT3_XATTR_SIZE(value_len)) {
 670                                 /* The old and the new value have the same
 671                                    size. Just replace. */
 672                                 here->e_value_size = cpu_to_le32(value_len);
 673                                 memset(val + size - EXT3_XATTR_PAD, 0,
 674                                        EXT3_XATTR_PAD); /* Clear pad bytes. */
 675                                 memcpy(val, value, value_len);
 676                                 goto skip_replace;
 677                         }
 678
 679                         /* Remove the old value. */
 680                         memmove(first_val + size, first_val, val - first_val);
 681                         memset(first_val, 0, size);
 682                         here->e_value_offs = 0;
 683                         min_offs += size;
 684
 685                         /* Adjust all value offsets. */
 686                         last = ENTRY(header+1);
 687                         while (!IS_LAST_ENTRY(last)) {
 688                                 size_t o = le16_to_cpu(last->e_value_offs);
 689                                 if (!last->e_value_block && o < offs)
 690                                         last->e_value_offs =
 691                                                 cpu_to_le16(o + size);
 692                                 last = EXT3_XATTR_NEXT(last);
 693                         }
 694                 }
 695                 if (value == NULL) {
 696                         /* Remove the old name. */
 697                         size_t size = EXT3_XATTR_LEN(name_len);
 698                         last = ENTRY((char *)last - size);
 699                         memmove(here, (char*)here + size,
 700                                 (char*)last - (char*)here);
 701                         memset(last, 0, size);
 702                 }
 703         }
 704
 705         if (value != NULL) {
 706                 /* Insert the new value. */
 707                 here->e_value_size = cpu_to_le32(value_len);
 708                 if (value_len) {
 709                         size_t size = EXT3_XATTR_SIZE(value_len);
 710                         char *val = (char *)header + min_offs - size;
 711                         here->e_value_offs =
 712                                 cpu_to_le16((char *)val - (char *)header);
 713                         memset(val + size - EXT3_XATTR_PAD, 0,
 714                                EXT3_XATTR_PAD); /* Clear the pad bytes. */
 715                         memcpy(val, value, value_len);
 716                 }
 717         }
 718
 719 skip_replace:
 720         if (IS_LAST_ENTRY(ENTRY(header+1))) {
 721                 /* This block is now empty. */
 722                 if (bh && header == HDR(bh))
 723                         unlock_buffer(bh);  /* we were modifying in-place. */
 724                 error = ext3_xattr_set_handle2(handle, inode, bh, NULL);
 725         } else {
 726                 ext3_xattr_rehash(header, here);
 727                 if (bh && header == HDR(bh))
 728                         unlock_buffer(bh);  /* we were modifying in-place. */
 729                 error = ext3_xattr_set_handle2(handle, inode, bh, header);
 730         }
 731
 732 cleanup:
 733         brelse(bh);
 734         if (!(bh && header == HDR(bh)))
 735                 kfree(header);
 736         up_write(&EXT3_I(inode)->xattr_sem);
 737
 738         return error;
 739 }
 740
 741 /*
 742  * Second half of ext3_xattr_set_handle(): Update the file system.
 743  */
 744 static int
 745 ext3_xattr_set_handle2(handle_t *handle, struct inode *inode,
 746                        struct buffer_head *old_bh,
 747                        struct ext3_xattr_header *header)
 748 {
 749         struct super_block *sb = inode->i_sb;
 750         struct buffer_head *new_bh = NULL;
 751         int credits = 0, error;
 752
 753         if (header) {
 754                 new_bh = ext3_xattr_cache_find(handle, inode, header, &credits);
 755                 if (new_bh) {
 756                         /* We found an identical block in the cache. */
 757                         if (new_bh == old_bh)
 758                                 ea_bdebug(new_bh, "keeping this block");
 759                         else {
 760                                 /* The old block is released after updating
 761                                    the inode. */
 762                                 ea_bdebug(new_bh, "reusing block");
 763
 764                                 error = -EDQUOT;
 765                                 if (DQUOT_ALLOC_BLOCK(inode, 1)) {
 766                                         unlock_buffer(new_bh);
 767                                         journal_release_buffer(handle, new_bh,
 768                                                                credits);
 769                                         goto cleanup;
 770                                 }
 771                                 HDR(new_bh)->h_refcount = cpu_to_le32(1 +
 772                                         le32_to_cpu(HDR(new_bh)->h_refcount));
 773                                 ea_bdebug(new_bh, "refcount now=%d",
 774                                         le32_to_cpu(HDR(new_bh)->h_refcount));
 775                         }
 776                         unlock_buffer(new_bh);
 777                 } else if (old_bh && header == HDR(old_bh)) {
 778                         /* Keep this block. No need to lock the block as we
 779                          * don't need to change the reference count. */
 780                         new_bh = old_bh;
 781                         get_bh(new_bh);
 782                         ext3_xattr_cache_insert(new_bh);
 783                 } else {
 784                         /* We need to allocate a new block */
 785                         int goal = le32_to_cpu(
 786                                         EXT3_SB(sb)->s_es->s_first_data_block) +
 787                                 EXT3_I(inode)->i_block_group *
 788                                 EXT3_BLOCKS_PER_GROUP(sb);
 789                         int block = ext3_new_block(handle,
 790                                 inode, goal, 0, 0, &error);
 791                         if (error)
 792                                 goto cleanup;
 793                         ea_idebug(inode, "creating block %d", block);
 794
 795                         new_bh = sb_getblk(sb, block);
 796                         if (!new_bh) {
 797 getblk_failed:
 798                                 ext3_free_blocks(handle, inode, block, 1);
 799                                 error = -EIO;
 800                                 goto cleanup;
 801                         }
 802                         lock_buffer(new_bh);
 803                         error = ext3_journal_get_create_access(handle, new_bh);
 804                         if (error) {
 805                                 unlock_buffer(new_bh);
 806                                 goto getblk_failed;
 807                         }
 808                         memcpy(new_bh->b_data, header, new_bh->b_size);
 809                         set_buffer_uptodate(new_bh);
 810                         unlock_buffer(new_bh);
 811                         ext3_xattr_cache_insert(new_bh);
 812
 813                         ext3_xattr_update_super_block(handle, sb);
 814                 }
 815                 error = ext3_journal_dirty_metadata(handle, new_bh);
 816                 if (error)
 817                         goto cleanup;
 818         }
 819
 820         /* Update the inode. */
 821         EXT3_I(inode)->i_file_acl = new_bh ? new_bh->b_blocknr : 0;
 822         inode->i_ctime = CURRENT_TIME;
 823         ext3_mark_inode_dirty(handle, inode);
 824         if (IS_SYNC(inode))
 825                 handle->h_sync = 1;
 826
 827         error = 0;
 828         if (old_bh && old_bh != new_bh) {
 829                 /*
 830                  * If there was an old block, and we are no longer using it,
 831                  * release the old block.
 832                 */
 833                 error = ext3_journal_get_write_access(handle, old_bh);
 834                 if (error)
 835                         goto cleanup;
 836                 lock_buffer(old_bh);
 837                 if (HDR(old_bh)->h_refcount == cpu_to_le32(1)) {
 838                         /* Free the old block. */
 839                         ea_bdebug(old_bh, "freeing");
 840                         ext3_free_blocks(handle, inode, old_bh->b_blocknr, 1);
 841
 842                         /* ext3_forget() calls bforget() for us, but we
 843                            let our caller release old_bh, so we need to
 844                            duplicate the handle before. */
 845                         get_bh(old_bh);
 846                         ext3_forget(handle, 1, inode, old_bh,old_bh->b_blocknr);
 847                 } else {
 848                         /* Decrement the refcount only. */
 849                         HDR(old_bh)->h_refcount = cpu_to_le32(
 850                                 le32_to_cpu(HDR(old_bh)->h_refcount) - 1);
 851                         DQUOT_FREE_BLOCK(inode, 1);
 852                         ext3_journal_dirty_metadata(handle, old_bh);
 853                         ea_bdebug(old_bh, "refcount now=%d",
 854                                 le32_to_cpu(HDR(old_bh)->h_refcount));
 855                 }
 856                 unlock_buffer(old_bh);
 857         }
 858
 859 cleanup:
 860         brelse(new_bh);
 861
 862         return error;
 863 }
 864
 865 /*
 866  * ext3_xattr_set()
 867  *
 868  * Like ext3_xattr_set_handle, but start from an inode. This extended
 869  * attribute modification is a filesystem transaction by itself.
 870  *
 871  * Returns 0, or a negative error number on failure.
 872  */
 873 int
 874 ext3_xattr_set(struct inode *inode, int name_index, const char *name,
 875                const void *value, size_t value_len, int flags)
 876 {
 877         handle_t *handle;
 878         int error;
 879
 880         handle = ext3_journal_start(inode, EXT3_DATA_TRANS_BLOCKS);
 881         if (IS_ERR(handle)) {
 882                 error = PTR_ERR(handle);
 883         } else {
 884                 int error2;
 885
 886                 error = ext3_xattr_set_handle(handle, inode, name_index, name,
 887                                               value, value_len, flags);
 888                 error2 = ext3_journal_stop(handle);
 889                 if (error == 0)
 890                         error = error2;
 891         }
 892
 893         return error;
 894 }
 895
 896 /*
 897  * ext3_xattr_delete_inode()
 898  *
 899  * Free extended attribute resources associated with this inode. This
 900  * is called immediately before an inode is freed.
 901  */
 902 void
 903 ext3_xattr_delete_inode(handle_t *handle, struct inode *inode)
 904 {
 905         struct buffer_head *bh = NULL;
 906
 907         down_write(&EXT3_I(inode)->xattr_sem);
 908         if (!EXT3_I(inode)->i_file_acl)
 909                 goto cleanup;
 910         bh = sb_bread(inode->i_sb, EXT3_I(inode)->i_file_acl);
 911         if (!bh) {
 912                 ext3_error(inode->i_sb, "ext3_xattr_delete_inode",
 913                         "inode %ld: block %d read error", inode->i_ino,
 914                         EXT3_I(inode)->i_file_acl);
 915                 goto cleanup;
 916         }
 917         if (HDR(bh)->h_magic != cpu_to_le32(EXT3_XATTR_MAGIC) ||
 918             HDR(bh)->h_blocks != cpu_to_le32(1)) {
 919                 ext3_error(inode->i_sb, "ext3_xattr_delete_inode",
 920                         "inode %ld: bad block %d", inode->i_ino,
 921                         EXT3_I(inode)->i_file_acl);
 922                 goto cleanup;
 923         }
 924         if (ext3_journal_get_write_access(handle, bh) != 0)
 925                 goto cleanup;
 926         lock_buffer(bh);
 927         if (HDR(bh)->h_refcount == cpu_to_le32(1)) {
 928                 ext3_xattr_cache_remove(bh);
 929                 ext3_free_blocks(handle, inode, EXT3_I(inode)->i_file_acl, 1);
 930                 get_bh(bh);
 931                 ext3_forget(handle, 1, inode, bh, EXT3_I(inode)->i_file_acl);
 932         } else {
 933                 HDR(bh)->h_refcount = cpu_to_le32(
 934                         le32_to_cpu(HDR(bh)->h_refcount) - 1);
 935                 ext3_journal_dirty_metadata(handle, bh);
 936                 if (IS_SYNC(inode))
 937                         handle->h_sync = 1;
 938                 DQUOT_FREE_BLOCK(inode, 1);
 939         }
 940         ea_bdebug(bh, "refcount now=%d", le32_to_cpu(HDR(bh)->h_refcount) - 1);
 941         unlock_buffer(bh);
 942         EXT3_I(inode)->i_file_acl = 0;
 943
 944 cleanup:
 945         brelse(bh);
 946         up_write(&EXT3_I(inode)->xattr_sem);
 947 }
 948
 949 /*
 950  * ext3_xattr_put_super()
 951  *
 952  * This is called when a file system is unmounted.
 953  */
 954 void
 955 ext3_xattr_put_super(struct super_block *sb)
 956 {
 957         mb_cache_shrink(ext3_xattr_cache, sb->s_bdev);
 958 }
 959
 960 /*
 961  * ext3_xattr_cache_insert()
 962  *
 963  * Create a new entry in the extended attribute cache, and insert
 964  * it unless such an entry is already in the cache.
 965  *
 966  * Returns 0, or a negative error number on failure.
 967  */
 968 static int
 969 ext3_xattr_cache_insert(struct buffer_head *bh)
 970 {
 971         __u32 hash = le32_to_cpu(HDR(bh)->h_hash);
 972         struct mb_cache_entry *ce;
 973         int error;
 974
 975         ce = mb_cache_entry_alloc(ext3_xattr_cache);
 976         if (!ce)
 977                 return -ENOMEM;
 978         error = mb_cache_entry_insert(ce, bh->b_bdev, bh->b_blocknr, &hash);
 979         if (error) {
 980                 mb_cache_entry_free(ce);
 981                 if (error == -EBUSY) {
 982                         ea_bdebug(bh, "already in cache (%d cache entries)",
 983                                 atomic_read(&ext3_xattr_cache->c_entry_count));
 984                         error = 0;
 985                 }
 986         } else {
 987                 ea_bdebug(bh, "inserting [%x] (%d cache entries)", (int)hash,
 988                           atomic_read(&ext3_xattr_cache->c_entry_count));
 989                 mb_cache_entry_release(ce);
 990         }
 991         return error;
 992 }
 993
 994 /*
 995  * ext3_xattr_cmp()
 996  *
 997  * Compare two extended attribute blocks for equality.
 998  *
 999  * Returns 0 if the blocks are equal, 1 if they differ, and
1000  * a negative error number on errors.
1001  */
1002 static int
1003 ext3_xattr_cmp(struct ext3_xattr_header *header1,
1004                struct ext3_xattr_header *header2)
1005 {
1006         struct ext3_xattr_entry *entry1, *entry2;
1007
1008         entry1 = ENTRY(header1+1);
1009         entry2 = ENTRY(header2+1);
1010         while (!IS_LAST_ENTRY(entry1)) {
1011                 if (IS_LAST_ENTRY(entry2))
1012                         return 1;
1013                 if (entry1->e_hash != entry2->e_hash ||
1014                     entry1->e_name_len != entry2->e_name_len ||
1015                     entry1->e_value_size != entry2->e_value_size ||
1016                     memcmp(entry1->e_name, entry2->e_name, entry1->e_name_len))
1017                         return 1;
1018                 if (entry1->e_value_block != 0 || entry2->e_value_block != 0)
1019                         return -EIO;
1020                 if (memcmp((char *)header1 + le16_to_cpu(entry1->e_value_offs),
1021                            (char *)header2 + le16_to_cpu(entry2->e_value_offs),
1022                            le32_to_cpu(entry1->e_value_size)))
1023                         return 1;
1024
1025                 entry1 = EXT3_XATTR_NEXT(entry1);
1026                 entry2 = EXT3_XATTR_NEXT(entry2);
1027         }
1028         if (!IS_LAST_ENTRY(entry2))
1029                 return 1;
1030         return 0;
1031 }
1032
1033 /*
1034  * ext3_xattr_cache_find()
1035  *
1036  * Find an identical extended attribute block.
1037  *
1038  * Returns a pointer to the block found, or NULL if such a block was
1039  * not found or an error occurred.
1040  */
1041 static struct buffer_head *
1042 ext3_xattr_cache_find(handle_t *handle, struct inode *inode,
1043                       struct ext3_xattr_header *header, int *credits)
1044 {
1045         __u32 hash = le32_to_cpu(header->h_hash);
1046         struct mb_cache_entry *ce;
1047
1048         if (!header->h_hash)
1049                 return NULL;  /* never share */
1050         ea_idebug(inode, "looking for cached blocks [%x]", (int)hash);
1051         ce = mb_cache_entry_find_first(ext3_xattr_cache, 0,
1052                                        inode->i_sb->s_bdev, hash);
1053         while (ce) {
1054                 struct buffer_head *bh = sb_bread(inode->i_sb, ce->e_block);
1055
1056                 if (!bh) {
1057                         ext3_error(inode->i_sb, "ext3_xattr_cache_find",
1058                                 "inode %ld: block %ld read error",
1059                                 inode->i_ino, (unsigned long) ce->e_block);
1060                 } else if (ext3_journal_get_write_access_credits(
1061                                 handle, bh, credits) == 0) {
1062                         /* ext3_journal_get_write_access() requires an unlocked
1063                          * bh, which complicates things here. */
1064                         lock_buffer(bh);
1065                         if (le32_to_cpu(HDR(bh)->h_refcount) >
1066                                    EXT3_XATTR_REFCOUNT_MAX) {
1067                                 ea_idebug(inode, "block %ld refcount %d>%d",
1068                                           (unsigned long) ce->e_block,
1069                                           le32_to_cpu(HDR(bh)->h_refcount),
1070                                           EXT3_XATTR_REFCOUNT_MAX);
1071                         } else if (!ext3_xattr_cmp(header, HDR(bh))) {
1072                                 mb_cache_entry_release(ce);
1073                                 /* buffer will be unlocked by caller */
1074                                 return bh;
1075                         }
1076                         unlock_buffer(bh);
1077                         journal_release_buffer(handle, bh, *credits);
1078                         *credits = 0;
1079                         brelse(bh);
1080                 }
1081                 ce = mb_cache_entry_find_next(ce, 0, inode->i_sb->s_bdev, hash);
1082         }
1083         return NULL;
1084 }
1085
1086 /*
1087  * ext3_xattr_cache_remove()
1088  *
1089  * Remove the cache entry of a block from the cache. Called when a
1090  * block becomes invalid.
1091  */
1092 static void
1093 ext3_xattr_cache_remove(struct buffer_head *bh)
1094 {
1095         struct mb_cache_entry *ce;
1096
1097         ce = mb_cache_entry_get(ext3_xattr_cache, bh->b_bdev,
1098                                 bh->b_blocknr);
1099         if (ce) {
1100                 ea_bdebug(bh, "removing (%d cache entries remaining)",
1101                           atomic_read(&ext3_xattr_cache->c_entry_count)-1);
1102                 mb_cache_entry_free(ce);
1103         } else
1104                 ea_bdebug(bh, "no cache entry");
1105 }
1106
1107 #define NAME_HASH_SHIFT 5
1108 #define VALUE_HASH_SHIFT 16
1109
1110 /*
1111  * ext3_xattr_hash_entry()
1112  *
1113  * Compute the hash of an extended attribute.
1114  */
1115 static inline void ext3_xattr_hash_entry(struct ext3_xattr_header *header,
1116                                          struct ext3_xattr_entry *entry)
1117 {
1118         __u32 hash = 0;
1119         char *name = entry->e_name;
1120         int n;
1121
1122         for (n=0; n < entry->e_name_len; n++) {
1123                 hash = (hash << NAME_HASH_SHIFT) ^
1124                        (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^
1125                        *name++;
1126         }
1127
1128         if (entry->e_value_block == 0 && entry->e_value_size != 0) {
1129                 __u32 *value = (__u32 *)((char *)header +
1130                         le16_to_cpu(entry->e_value_offs));
1131                 for (n = (le32_to_cpu(entry->e_value_size) +
1132                      EXT3_XATTR_ROUND) >> EXT3_XATTR_PAD_BITS; n; n--) {
1133                         hash = (hash << VALUE_HASH_SHIFT) ^
1134                                (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^
1135                                le32_to_cpu(*value++);
1136                 }
1137         }
1138         entry->e_hash = cpu_to_le32(hash);
1139 }
1140
1141 #undef NAME_HASH_SHIFT
1142 #undef VALUE_HASH_SHIFT
1143
1144 #define BLOCK_HASH_SHIFT 16
1145
1146 /*
1147  * ext3_xattr_rehash()
1148  *
1149  * Re-compute the extended attribute hash value after an entry has changed.
1150  */
1151 static void ext3_xattr_rehash(struct ext3_xattr_header *header,
1152                               struct ext3_xattr_entry *entry)
1153 {
1154         struct ext3_xattr_entry *here;
1155         __u32 hash = 0;
1156
1157         ext3_xattr_hash_entry(header, entry);
1158         here = ENTRY(header+1);
1159         while (!IS_LAST_ENTRY(here)) {
1160                 if (!here->e_hash) {
1161                         /* Block is not shared if an entry's hash value == 0 */
1162                         hash = 0;
1163                         break;
1164                 }
1165                 hash = (hash << BLOCK_HASH_SHIFT) ^
1166                        (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^
1167                        le32_to_cpu(here->e_hash);
1168                 here = EXT3_XATTR_NEXT(here);
1169         }
1170         header->h_hash = cpu_to_le32(hash);
1171 }
1172
1173 #undef BLOCK_HASH_SHIFT
1174
1175 int __init
1176 init_ext3_xattr(void)
1177 {
1178         int     err;
1179
1180         err = ext3_xattr_register(EXT3_XATTR_INDEX_USER,
1181                                   &ext3_xattr_user_handler);
1182         if (err)
1183                 return err;
1184         err = ext3_xattr_register(EXT3_XATTR_INDEX_TRUSTED,
1185                                   &ext3_xattr_trusted_handler);
1186         if (err)
1187                 goto out;
1188 #ifdef CONFIG_EXT3_FS_SECURITY
1189         err = ext3_xattr_register(EXT3_XATTR_INDEX_SECURITY,
1190                                   &ext3_xattr_security_handler);
1191         if (err)
1192                 goto out1;
1193 #endif
1194 #ifdef CONFIG_EXT3_FS_POSIX_ACL
1195         err = init_ext3_acl();
1196         if (err)
1197                 goto out2;
1198 #endif
1199         ext3_xattr_cache = mb_cache_create("ext3_xattr", NULL,
1200                 sizeof(struct mb_cache_entry) +
1201                 sizeof(struct mb_cache_entry_index), 1, 6);
1202         if (!ext3_xattr_cache) {
1203                 err = -ENOMEM;
1204                 goto out3;
1205         }
1206         return 0;
1207 out3:
1208 #ifdef CONFIG_EXT3_FS_POSIX_ACL
1209         exit_ext3_acl();
1210 out2:
1211 #endif
1212 #ifdef CONFIG_EXT3_FS_SECURITY
1213         ext3_xattr_unregister(EXT3_XATTR_INDEX_SECURITY,
1214                               &ext3_xattr_security_handler);
1215 out1:
1216 #endif
1217         ext3_xattr_unregister(EXT3_XATTR_INDEX_TRUSTED,
1218                               &ext3_xattr_trusted_handler);
1219 out:
1220         ext3_xattr_unregister(EXT3_XATTR_INDEX_USER,
1221                               &ext3_xattr_user_handler);
1222         return err;
1223 }
1224
1225 void
1226 exit_ext3_xattr(void)
1227 {
1228         if (ext3_xattr_cache)
1229                 mb_cache_destroy(ext3_xattr_cache);
1230         ext3_xattr_cache = NULL;
1231 #ifdef CONFIG_EXT3_FS_POSIX_ACL
1232         exit_ext3_acl();
1233 #endif
1234 #ifdef CONFIG_EXT3_FS_SECURITY
1235         ext3_xattr_unregister(EXT3_XATTR_INDEX_SECURITY,
1236                               &ext3_xattr_security_handler);
1237 #endif
1238         ext3_xattr_unregister(EXT3_XATTR_INDEX_TRUSTED,
1239                               &ext3_xattr_trusted_handler);
1240         ext3_xattr_unregister(EXT3_XATTR_INDEX_USER,
1241                               &ext3_xattr_user_handler);
1242 }