| 1 | |
| 2 | |
| 3 | * linux/fs/ext2/xattr.c
|
| 4 | *
|
| 5 | * Copyright (C) 2001-2003 Andreas Gruenbacher <[email protected]>
|
| 6 | *
|
| 7 | * Fix by Harrison Xing <[email protected]>.
|
| 8 | * Extended attributes for symlinks and special files added per
|
| 9 | * suggestion of Luka Renko <[email protected]>.
|
| 10 | * xattr consolidation Copyright (c) 2004 James Morris <[email protected]>,
|
| 11 | * Red Hat Inc.
|
| 12 | *
|
| 13 |
|
| 14 |
|
| 15 | |
| 16 | * Extended attributes are stored on disk blocks allocated outside of
|
| 17 | * any inode. The i_file_acl field is then made to point to this allocated
|
| 18 | * block. If all extended attributes of an inode are identical, these
|
| 19 | * inodes may share the same extended attribute block. Such situations
|
| 20 | * are automatically detected by keeping a cache of recent attribute block
|
| 21 | * numbers and hashes over the block's contents in memory.
|
| 22 | *
|
| 23 | *
|
| 24 | * Extended attribute block layout:
|
| 25 | *
|
| 26 | * +------------------+
|
| 27 | * | header |
|
| 28 | * | entry 1 | |
|
| 29 | * | entry 2 | | growing downwards
|
| 30 | * | entry 3 | v
|
| 31 | * | four null bytes |
|
| 32 | * | . . . |
|
| 33 | * | value 1 | ^
|
| 34 | * | value 3 | | growing upwards
|
| 35 | * | value 2 | |
|
| 36 | * +------------------+
|
| 37 | *
|
| 38 | * The block header is followed by multiple entry descriptors. These entry
|
| 39 | * descriptors are variable in size, and aligned to EXT2_XATTR_PAD
|
| 40 | * byte boundaries. The entry descriptors are sorted by attribute name,
|
| 41 | * so that two extended attribute blocks can be compared efficiently.
|
| 42 | *
|
| 43 | * Attribute values are aligned to the end of the block, stored in
|
| 44 | * no specific order. They are also padded to EXT2_XATTR_PAD byte
|
| 45 | * boundaries. No additional gaps are left between them.
|
| 46 | *
|
| 47 | * Locking strategy
|
| 48 | * ----------------
|
| 49 | * EXT2_I(inode)->i_file_acl is protected by EXT2_I(inode)->xattr_sem.
|
| 50 | * EA blocks are only changed if they are exclusive to an inode, so
|
| 51 | * holding xattr_sem also means that nothing but the EA block's reference
|
| 52 | * count will change. Multiple writers to an EA block are synchronized
|
| 53 | * by the bh lock. No more than a single bh lock is held at any time
|
| 54 | * to avoid deadlocks.
|
| 55 |
|
| 56 |
|
| 57 | #include <linux/buffer_head.h>
|
| 58 | #include <linux/init.h>
|
| 59 | #include <linux/printk.h>
|
| 60 | #include <linux/slab.h>
|
| 61 | #include <linux/mbcache.h>
|
| 62 | #include <linux/quotaops.h>
|
| 63 | #include <linux/rwsem.h>
|
| 64 | #include <linux/security.h>
|
| 65 | #include "ext2.h"
|
| 66 | #include "xattr.h"
|
| 67 | #include "acl.h"
|
| 68 |
|
| 69 | #define HDR(bh) ((struct ext2_xattr_header *)((bh)->b_data))
|
| 70 | #define ENTRY(ptr) ((struct ext2_xattr_entry *)(ptr))
|
| 71 | #define FIRST_ENTRY(bh) ENTRY(HDR(bh)+1)
|
| 72 | #define IS_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0)
|
| 73 |
|
| 74 | #ifdef EXT2_XATTR_DEBUG
|
| 75 | # define ea_idebug(inode, f...) do { \
|
| 76 | printk(KERN_DEBUG "inode %s:%llu: ", \
|
| 77 | inode->i_sb->s_id, inode->i_ino); \
|
| 78 | printk(f); \
|
| 79 | printk("\n"); \
|
| 80 | } while (0)
|
| 81 | # define ea_bdebug(bh, f...) do { \
|
| 82 | printk(KERN_DEBUG "block %pg:%lu: ", \
|
| 83 | bh->b_bdev, (unsigned long) bh->b_blocknr); \
|
| 84 | printk(f); \
|
| 85 | printk("\n"); \
|
| 86 | } while (0)
|
| 87 | #else
|
| 88 | # define ea_idebug(inode, f...) no_printk(f)
|
| 89 | # define ea_bdebug(bh, f...) no_printk(f)
|
| 90 | #endif
|
| 91 |
|
| 92 | static int ext2_xattr_set2(struct inode *, struct buffer_head *,
|
| 93 | struct ext2_xattr_header *);
|
| 94 |
|
| 95 | static int ext2_xattr_cache_insert(struct mb_cache *, struct buffer_head *);
|
| 96 | static struct buffer_head *ext2_xattr_cache_find(struct inode *,
|
| 97 | struct ext2_xattr_header *);
|
| 98 | static void ext2_xattr_rehash(struct ext2_xattr_header *,
|
| 99 | struct ext2_xattr_entry *);
|
| 100 |
|
| 101 | static const struct xattr_handler * const ext2_xattr_handler_map[] = {
|
| 102 | [EXT2_XATTR_INDEX_USER] = &ext2_xattr_user_handler,
|
| 103 | #ifdef CONFIG_EXT2_FS_POSIX_ACL
|
| 104 | [EXT2_XATTR_INDEX_POSIX_ACL_ACCESS] = &nop_posix_acl_access,
|
| 105 | [EXT2_XATTR_INDEX_POSIX_ACL_DEFAULT] = &nop_posix_acl_default,
|
| 106 | #endif
|
| 107 | [EXT2_XATTR_INDEX_TRUSTED] = &ext2_xattr_trusted_handler,
|
| 108 | #ifdef CONFIG_EXT2_FS_SECURITY
|
| 109 | [EXT2_XATTR_INDEX_SECURITY] = &ext2_xattr_security_handler,
|
| 110 | #endif
|
| 111 | };
|
| 112 |
|
| 113 | const struct xattr_handler * const ext2_xattr_handlers[] = {
|
| 114 | &ext2_xattr_user_handler,
|
| 115 | &ext2_xattr_trusted_handler,
|
| 116 | #ifdef CONFIG_EXT2_FS_SECURITY
|
| 117 | &ext2_xattr_security_handler,
|
| 118 | #endif
|
| 119 | NULL
|
| 120 | };
|
| 121 |
|
| 122 | #define EA_BLOCK_CACHE(inode) (EXT2_SB(inode->i_sb)->s_ea_block_cache)
|
| 123 |
|
| 124 | static inline const char *ext2_xattr_prefix(int name_index,
|
| 125 | struct dentry *dentry)
|
| 126 | {
|
| 127 | const struct xattr_handler *handler = NULL;
|
| 128 |
|
| 129 | if (name_index > 0 && name_index < ARRAY_SIZE(ext2_xattr_handler_map))
|
| 130 | handler = ext2_xattr_handler_map[name_index];
|
| 131 |
|
| 132 | if (!xattr_handler_can_list(handler, dentry))
|
| 133 | return NULL;
|
| 134 |
|
| 135 | return xattr_prefix(handler);
|
| 136 | }
|
| 137 |
|
| 138 | static bool
|
| 139 | ext2_xattr_header_valid(struct ext2_xattr_header *header)
|
| 140 | {
|
| 141 | if (header->h_magic != cpu_to_le32(EXT2_XATTR_MAGIC) ||
|
| 142 | header->h_blocks != cpu_to_le32(1))
|
| 143 | return false;
|
| 144 |
|
| 145 | return true;
|
| 146 | }
|
| 147 |
|
| 148 | static bool
|
| 149 | ext2_xattr_entry_valid(struct ext2_xattr_entry *entry,
|
| 150 | char *end, size_t end_offs)
|
| 151 | {
|
| 152 | struct ext2_xattr_entry *next;
|
| 153 | size_t size;
|
| 154 |
|
| 155 | next = EXT2_XATTR_NEXT(entry);
|
| 156 | if ((char *)next >= end)
|
| 157 | return false;
|
| 158 |
|
| 159 | if (entry->e_value_block != 0)
|
| 160 | return false;
|
| 161 |
|
| 162 | size = le32_to_cpu(entry->e_value_size);
|
| 163 | if (size > end_offs ||
|
| 164 | le16_to_cpu(entry->e_value_offs) + size > end_offs)
|
| 165 | return false;
|
| 166 |
|
| 167 | return true;
|
| 168 | }
|
| 169 |
|
| 170 | static int
|
| 171 | ext2_xattr_cmp_entry(int name_index, size_t name_len, const char *name,
|
| 172 | struct ext2_xattr_entry *entry)
|
| 173 | {
|
| 174 | int cmp;
|
| 175 |
|
| 176 | cmp = name_index - entry->e_name_index;
|
| 177 | if (!cmp)
|
| 178 | cmp = name_len - entry->e_name_len;
|
| 179 | if (!cmp)
|
| 180 | cmp = memcmp(name, entry->e_name, name_len);
|
| 181 |
|
| 182 | return cmp;
|
| 183 | }
|
| 184 |
|
| 185 | |
| 186 | * ext2_xattr_get()
|
| 187 | *
|
| 188 | * Copy an extended attribute into the buffer
|
| 189 | * provided, or compute the buffer size required.
|
| 190 | * Buffer is NULL to compute the size of the buffer required.
|
| 191 | *
|
| 192 | * Returns a negative error number on failure, or the number of bytes
|
| 193 | * used / required on success.
|
| 194 |
|
| 195 | int
|
| 196 | ext2_xattr_get(struct inode *inode, int name_index, const char *name,
|
| 197 | void *buffer, size_t buffer_size)
|
| 198 | {
|
| 199 | struct buffer_head *bh = NULL;
|
| 200 | struct ext2_xattr_entry *entry;
|
| 201 | size_t name_len, size;
|
| 202 | char *end;
|
| 203 | int error, not_found;
|
| 204 | struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
|
| 205 |
|
| 206 | ea_idebug(inode, "name=%d.%s, buffer=%p, buffer_size=%ld",
|
| 207 | name_index, name, buffer, (long)buffer_size);
|
| 208 |
|
| 209 | if (name == NULL)
|
| 210 | return -EINVAL;
|
| 211 | name_len = strlen(name);
|
| 212 | if (name_len > 255)
|
| 213 | return -ERANGE;
|
| 214 |
|
| 215 | down_read(&EXT2_I(inode)->xattr_sem);
|
| 216 | error = -ENODATA;
|
| 217 | if (!EXT2_I(inode)->i_file_acl)
|
| 218 | goto cleanup;
|
| 219 | ea_idebug(inode, "reading block %d", EXT2_I(inode)->i_file_acl);
|
| 220 | bh = sb_bread(inode->i_sb, EXT2_I(inode)->i_file_acl);
|
| 221 | error = -EIO;
|
| 222 | if (!bh)
|
| 223 | goto cleanup;
|
| 224 | ea_bdebug(bh, "b_count=%d, refcount=%d",
|
| 225 | atomic_read(&(bh->b_count)), le32_to_cpu(HDR(bh)->h_refcount));
|
| 226 | end = bh->b_data + bh->b_size;
|
| 227 | if (!ext2_xattr_header_valid(HDR(bh))) {
|
| 228 | bad_block:
|
| 229 | ext2_error(inode->i_sb, "ext2_xattr_get",
|
| 230 | "inode %llu: bad block %d", inode->i_ino,
|
| 231 | EXT2_I(inode)->i_file_acl);
|
| 232 | error = -EIO;
|
| 233 | goto cleanup;
|
| 234 | }
|
| 235 |
|
| 236 |
|
| 237 | entry = FIRST_ENTRY(bh);
|
| 238 | while (!IS_LAST_ENTRY(entry)) {
|
| 239 | if (!ext2_xattr_entry_valid(entry, end,
|
| 240 | inode->i_sb->s_blocksize))
|
| 241 | goto bad_block;
|
| 242 |
|
| 243 | not_found = ext2_xattr_cmp_entry(name_index, name_len, name,
|
| 244 | entry);
|
| 245 | if (!not_found)
|
| 246 | goto found;
|
| 247 | if (not_found < 0)
|
| 248 | break;
|
| 249 |
|
| 250 | entry = EXT2_XATTR_NEXT(entry);
|
| 251 | }
|
| 252 | if (ext2_xattr_cache_insert(ea_block_cache, bh))
|
| 253 | ea_idebug(inode, "cache insert failed");
|
| 254 | error = -ENODATA;
|
| 255 | goto cleanup;
|
| 256 | found:
|
| 257 | size = le32_to_cpu(entry->e_value_size);
|
| 258 | if (ext2_xattr_cache_insert(ea_block_cache, bh))
|
| 259 | ea_idebug(inode, "cache insert failed");
|
| 260 | if (buffer) {
|
| 261 | error = -ERANGE;
|
| 262 | if (size > buffer_size)
|
| 263 | goto cleanup;
|
| 264 |
|
| 265 | memcpy(buffer, bh->b_data + le16_to_cpu(entry->e_value_offs),
|
| 266 | size);
|
| 267 | }
|
| 268 | error = size;
|
| 269 |
|
| 270 | cleanup:
|
| 271 | brelse(bh);
|
| 272 | up_read(&EXT2_I(inode)->xattr_sem);
|
| 273 |
|
| 274 | return error;
|
| 275 | }
|
| 276 |
|
| 277 | |
| 278 | * ext2_xattr_list()
|
| 279 | *
|
| 280 | * Copy a list of attribute names into the buffer
|
| 281 | * provided, or compute the buffer size required.
|
| 282 | * Buffer is NULL to compute the size of the buffer required.
|
| 283 | *
|
| 284 | * Returns a negative error number on failure, or the number of bytes
|
| 285 | * used / required on success.
|
| 286 |
|
| 287 | static int
|
| 288 | ext2_xattr_list(struct dentry *dentry, char *buffer, size_t buffer_size)
|
| 289 | {
|
| 290 | struct inode *inode = d_inode(dentry);
|
| 291 | struct buffer_head *bh = NULL;
|
| 292 | struct ext2_xattr_entry *entry;
|
| 293 | char *end;
|
| 294 | size_t rest = buffer_size;
|
| 295 | int error;
|
| 296 | struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
|
| 297 |
|
| 298 | ea_idebug(inode, "buffer=%p, buffer_size=%ld",
|
| 299 | buffer, (long)buffer_size);
|
| 300 |
|
| 301 | down_read(&EXT2_I(inode)->xattr_sem);
|
| 302 | error = 0;
|
| 303 | if (!EXT2_I(inode)->i_file_acl)
|
| 304 | goto cleanup;
|
| 305 | ea_idebug(inode, "reading block %d", EXT2_I(inode)->i_file_acl);
|
| 306 | bh = sb_bread(inode->i_sb, EXT2_I(inode)->i_file_acl);
|
| 307 | error = -EIO;
|
| 308 | if (!bh)
|
| 309 | goto cleanup;
|
| 310 | ea_bdebug(bh, "b_count=%d, refcount=%d",
|
| 311 | atomic_read(&(bh->b_count)), le32_to_cpu(HDR(bh)->h_refcount));
|
| 312 | end = bh->b_data + bh->b_size;
|
| 313 | if (!ext2_xattr_header_valid(HDR(bh))) {
|
| 314 | bad_block:
|
| 315 | ext2_error(inode->i_sb, "ext2_xattr_list",
|
| 316 | "inode %llu: bad block %d", inode->i_ino,
|
| 317 | EXT2_I(inode)->i_file_acl);
|
| 318 | error = -EIO;
|
| 319 | goto cleanup;
|
| 320 | }
|
| 321 |
|
| 322 |
|
| 323 | entry = FIRST_ENTRY(bh);
|
| 324 | while (!IS_LAST_ENTRY(entry)) {
|
| 325 | if (!ext2_xattr_entry_valid(entry, end,
|
| 326 | inode->i_sb->s_blocksize))
|
| 327 | goto bad_block;
|
| 328 | entry = EXT2_XATTR_NEXT(entry);
|
| 329 | }
|
| 330 | if (ext2_xattr_cache_insert(ea_block_cache, bh))
|
| 331 | ea_idebug(inode, "cache insert failed");
|
| 332 |
|
| 333 |
|
| 334 | for (entry = FIRST_ENTRY(bh); !IS_LAST_ENTRY(entry);
|
| 335 | entry = EXT2_XATTR_NEXT(entry)) {
|
| 336 | const char *prefix;
|
| 337 |
|
| 338 | prefix = ext2_xattr_prefix(entry->e_name_index, dentry);
|
| 339 | if (prefix) {
|
| 340 | size_t prefix_len = strlen(prefix);
|
| 341 | size_t size = prefix_len + entry->e_name_len + 1;
|
| 342 |
|
| 343 | if (buffer) {
|
| 344 | if (size > rest) {
|
| 345 | error = -ERANGE;
|
| 346 | goto cleanup;
|
| 347 | }
|
| 348 | memcpy(buffer, prefix, prefix_len);
|
| 349 | buffer += prefix_len;
|
| 350 | memcpy(buffer, entry->e_name, entry->e_name_len);
|
| 351 | buffer += entry->e_name_len;
|
| 352 | *buffer++ = 0;
|
| 353 | }
|
| 354 | rest -= size;
|
| 355 | }
|
| 356 | }
|
| 357 | error = buffer_size - rest;
|
| 358 |
|
| 359 | cleanup:
|
| 360 | brelse(bh);
|
| 361 | up_read(&EXT2_I(inode)->xattr_sem);
|
| 362 |
|
| 363 | return error;
|
| 364 | }
|
| 365 |
|
| 366 | |
| 367 | * Inode operation listxattr()
|
| 368 | *
|
| 369 | * d_inode(dentry)->i_mutex: don't care
|
| 370 |
|
| 371 | ssize_t
|
| 372 | ext2_listxattr(struct dentry *dentry, char *buffer, size_t size)
|
| 373 | {
|
| 374 | return ext2_xattr_list(dentry, buffer, size);
|
| 375 | }
|
| 376 |
|
| 377 | |
| 378 | * If the EXT2_FEATURE_COMPAT_EXT_ATTR feature of this file system is
|
| 379 | * not set, set it.
|
| 380 |
|
| 381 | static void ext2_xattr_update_super_block(struct super_block *sb)
|
| 382 | {
|
| 383 | if (EXT2_HAS_COMPAT_FEATURE(sb, EXT2_FEATURE_COMPAT_EXT_ATTR))
|
| 384 | return;
|
| 385 |
|
| 386 | spin_lock(&EXT2_SB(sb)->s_lock);
|
| 387 | ext2_update_dynamic_rev(sb);
|
| 388 | EXT2_SET_COMPAT_FEATURE(sb, EXT2_FEATURE_COMPAT_EXT_ATTR);
|
| 389 | spin_unlock(&EXT2_SB(sb)->s_lock);
|
| 390 | mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
|
| 391 | }
|
| 392 |
|
| 393 | |
| 394 | * ext2_xattr_set()
|
| 395 | *
|
| 396 | * Create, replace or remove an extended attribute for this inode. Value
|
| 397 | * is NULL to remove an existing extended attribute, and non-NULL to
|
| 398 | * either replace an existing extended attribute, or create a new extended
|
| 399 | * attribute. The flags XATTR_REPLACE and XATTR_CREATE
|
| 400 | * specify that an extended attribute must exist and must not exist
|
| 401 | * previous to the call, respectively.
|
| 402 | *
|
| 403 | * Returns 0, or a negative error number on failure.
|
| 404 |
|
| 405 | int
|
| 406 | ext2_xattr_set(struct inode *inode, int name_index, const char *name,
|
| 407 | const void *value, size_t value_len, int flags)
|
| 408 | {
|
| 409 | struct super_block *sb = inode->i_sb;
|
| 410 | struct buffer_head *bh = NULL;
|
| 411 | struct ext2_xattr_header *header = NULL;
|
| 412 | struct ext2_xattr_entry *here = NULL, *last = NULL;
|
| 413 | size_t name_len, free, min_offs = sb->s_blocksize;
|
| 414 | int not_found = 1, error;
|
| 415 | char *end;
|
| 416 |
|
| 417 | |
| 418 | * header -- Points either into bh, or to a temporarily
|
| 419 | * allocated buffer.
|
| 420 | * here -- The named entry found, or the place for inserting, within
|
| 421 | * the block pointed to by header.
|
| 422 | * last -- Points right after the last named entry within the block
|
| 423 | * pointed to by header.
|
| 424 | * min_offs -- The offset of the first value (values are aligned
|
| 425 | * towards the end of the block).
|
| 426 | * end -- Points right after the block pointed to by header.
|
| 427 |
|
| 428 |
|
| 429 | ea_idebug(inode, "name=%d.%s, value=%p, value_len=%ld",
|
| 430 | name_index, name, value, (long)value_len);
|
| 431 |
|
| 432 | if (value == NULL)
|
| 433 | value_len = 0;
|
| 434 | if (name == NULL)
|
| 435 | return -EINVAL;
|
| 436 | name_len = strlen(name);
|
| 437 | if (name_len > 255 || value_len > sb->s_blocksize)
|
| 438 | return -ERANGE;
|
| 439 | error = dquot_initialize(inode);
|
| 440 | if (error)
|
| 441 | return error;
|
| 442 | down_write(&EXT2_I(inode)->xattr_sem);
|
| 443 | if (EXT2_I(inode)->i_file_acl) {
|
| 444 |
|
| 445 | bh = sb_bread(sb, EXT2_I(inode)->i_file_acl);
|
| 446 | error = -EIO;
|
| 447 | if (!bh)
|
| 448 | goto cleanup;
|
| 449 | ea_bdebug(bh, "b_count=%d, refcount=%d",
|
| 450 | atomic_read(&(bh->b_count)),
|
| 451 | le32_to_cpu(HDR(bh)->h_refcount));
|
| 452 | header = HDR(bh);
|
| 453 | end = bh->b_data + bh->b_size;
|
| 454 | if (!ext2_xattr_header_valid(header)) {
|
| 455 | bad_block:
|
| 456 | ext2_error(sb, "ext2_xattr_set",
|
| 457 | "inode %llu: bad block %d", inode->i_ino,
|
| 458 | EXT2_I(inode)->i_file_acl);
|
| 459 | error = -EIO;
|
| 460 | goto cleanup;
|
| 461 | }
|
| 462 | |
| 463 | * Find the named attribute. If not found, 'here' will point
|
| 464 | * to entry where the new attribute should be inserted to
|
| 465 | * maintain sorting.
|
| 466 |
|
| 467 | last = FIRST_ENTRY(bh);
|
| 468 | while (!IS_LAST_ENTRY(last)) {
|
| 469 | if (!ext2_xattr_entry_valid(last, end, sb->s_blocksize))
|
| 470 | goto bad_block;
|
| 471 | if (last->e_value_size) {
|
| 472 | size_t offs = le16_to_cpu(last->e_value_offs);
|
| 473 | if (offs < min_offs)
|
| 474 | min_offs = offs;
|
| 475 | }
|
| 476 | if (not_found > 0) {
|
| 477 | not_found = ext2_xattr_cmp_entry(name_index,
|
| 478 | name_len,
|
| 479 | name, last);
|
| 480 | if (not_found <= 0)
|
| 481 | here = last;
|
| 482 | }
|
| 483 | last = EXT2_XATTR_NEXT(last);
|
| 484 | }
|
| 485 | if (not_found > 0)
|
| 486 | here = last;
|
| 487 |
|
| 488 |
|
| 489 | free = min_offs - ((char*)last - (char*)header) - sizeof(__u32);
|
| 490 | } else {
|
| 491 |
|
| 492 | free = sb->s_blocksize -
|
| 493 | sizeof(struct ext2_xattr_header) - sizeof(__u32);
|
| 494 | }
|
| 495 |
|
| 496 | if (not_found) {
|
| 497 |
|
| 498 | error = -ENODATA;
|
| 499 | if (flags & XATTR_REPLACE)
|
| 500 | goto cleanup;
|
| 501 | error = 0;
|
| 502 | if (value == NULL)
|
| 503 | goto cleanup;
|
| 504 | } else {
|
| 505 |
|
| 506 | error = -EEXIST;
|
| 507 | if (flags & XATTR_CREATE)
|
| 508 | goto cleanup;
|
| 509 | free += EXT2_XATTR_SIZE(le32_to_cpu(here->e_value_size));
|
| 510 | free += EXT2_XATTR_LEN(name_len);
|
| 511 | }
|
| 512 | error = -ENOSPC;
|
| 513 | if (free < EXT2_XATTR_LEN(name_len) + EXT2_XATTR_SIZE(value_len))
|
| 514 | goto cleanup;
|
| 515 |
|
| 516 |
|
| 517 |
|
| 518 | if (header) {
|
| 519 | int offset;
|
| 520 |
|
| 521 | lock_buffer(bh);
|
| 522 | if (header->h_refcount == cpu_to_le32(1)) {
|
| 523 | __u32 hash = le32_to_cpu(header->h_hash);
|
| 524 | struct mb_cache_entry *oe;
|
| 525 |
|
| 526 | oe = mb_cache_entry_delete_or_get(EA_BLOCK_CACHE(inode),
|
| 527 | hash, bh->b_blocknr);
|
| 528 | if (!oe) {
|
| 529 | ea_bdebug(bh, "modifying in-place");
|
| 530 | goto update_block;
|
| 531 | }
|
| 532 | |
| 533 | * Someone is trying to reuse the block, leave it alone
|
| 534 |
|
| 535 | mb_cache_entry_put(EA_BLOCK_CACHE(inode), oe);
|
| 536 | }
|
| 537 | unlock_buffer(bh);
|
| 538 | ea_bdebug(bh, "cloning");
|
| 539 | header = kmemdup(HDR(bh), bh->b_size, GFP_KERNEL);
|
| 540 | error = -ENOMEM;
|
| 541 | if (header == NULL)
|
| 542 | goto cleanup;
|
| 543 | header->h_refcount = cpu_to_le32(1);
|
| 544 |
|
| 545 | offset = (char *)here - bh->b_data;
|
| 546 | here = ENTRY((char *)header + offset);
|
| 547 | offset = (char *)last - bh->b_data;
|
| 548 | last = ENTRY((char *)header + offset);
|
| 549 | } else {
|
| 550 |
|
| 551 | header = kzalloc(sb->s_blocksize, GFP_KERNEL);
|
| 552 | error = -ENOMEM;
|
| 553 | if (header == NULL)
|
| 554 | goto cleanup;
|
| 555 | header->h_magic = cpu_to_le32(EXT2_XATTR_MAGIC);
|
| 556 | header->h_blocks = header->h_refcount = cpu_to_le32(1);
|
| 557 | last = here = ENTRY(header+1);
|
| 558 | }
|
| 559 |
|
| 560 | update_block:
|
| 561 |
|
| 562 |
|
| 563 | if (not_found) {
|
| 564 |
|
| 565 | size_t size = EXT2_XATTR_LEN(name_len);
|
| 566 | size_t rest = (char *)last - (char *)here;
|
| 567 | memmove((char *)here + size, here, rest);
|
| 568 | memset(here, 0, size);
|
| 569 | here->e_name_index = name_index;
|
| 570 | here->e_name_len = name_len;
|
| 571 | memcpy(here->e_name, name, name_len);
|
| 572 | } else {
|
| 573 | if (here->e_value_size) {
|
| 574 | char *first_val = (char *)header + min_offs;
|
| 575 | size_t offs = le16_to_cpu(here->e_value_offs);
|
| 576 | char *val = (char *)header + offs;
|
| 577 | size_t size = EXT2_XATTR_SIZE(
|
| 578 | le32_to_cpu(here->e_value_size));
|
| 579 |
|
| 580 | if (size == EXT2_XATTR_SIZE(value_len)) {
|
| 581 | |
| 582 | size. Just replace.
|
| 583 | here->e_value_size = cpu_to_le32(value_len);
|
| 584 | memset(val + size - EXT2_XATTR_PAD, 0,
|
| 585 | EXT2_XATTR_PAD);
|
| 586 | memcpy(val, value, value_len);
|
| 587 | goto skip_replace;
|
| 588 | }
|
| 589 |
|
| 590 |
|
| 591 | memmove(first_val + size, first_val, val - first_val);
|
| 592 | memset(first_val, 0, size);
|
| 593 | min_offs += size;
|
| 594 |
|
| 595 |
|
| 596 | last = ENTRY(header+1);
|
| 597 | while (!IS_LAST_ENTRY(last)) {
|
| 598 | size_t o = le16_to_cpu(last->e_value_offs);
|
| 599 | if (o < offs)
|
| 600 | last->e_value_offs =
|
| 601 | cpu_to_le16(o + size);
|
| 602 | last = EXT2_XATTR_NEXT(last);
|
| 603 | }
|
| 604 |
|
| 605 | here->e_value_offs = 0;
|
| 606 | }
|
| 607 | if (value == NULL) {
|
| 608 |
|
| 609 | size_t size = EXT2_XATTR_LEN(name_len);
|
| 610 | last = ENTRY((char *)last - size);
|
| 611 | memmove(here, (char*)here + size,
|
| 612 | (char*)last - (char*)here);
|
| 613 | memset(last, 0, size);
|
| 614 | }
|
| 615 | }
|
| 616 |
|
| 617 | if (value != NULL) {
|
| 618 |
|
| 619 | here->e_value_size = cpu_to_le32(value_len);
|
| 620 | if (value_len) {
|
| 621 | size_t size = EXT2_XATTR_SIZE(value_len);
|
| 622 | char *val = (char *)header + min_offs - size;
|
| 623 | here->e_value_offs =
|
| 624 | cpu_to_le16((char *)val - (char *)header);
|
| 625 | memset(val + size - EXT2_XATTR_PAD, 0,
|
| 626 | EXT2_XATTR_PAD);
|
| 627 | memcpy(val, value, value_len);
|
| 628 | }
|
| 629 | }
|
| 630 |
|
| 631 | skip_replace:
|
| 632 | if (IS_LAST_ENTRY(ENTRY(header+1))) {
|
| 633 |
|
| 634 | if (bh && header == HDR(bh))
|
| 635 | unlock_buffer(bh);
|
| 636 | error = ext2_xattr_set2(inode, bh, NULL);
|
| 637 | } else {
|
| 638 | ext2_xattr_rehash(header, here);
|
| 639 | if (bh && header == HDR(bh))
|
| 640 | unlock_buffer(bh);
|
| 641 | error = ext2_xattr_set2(inode, bh, header);
|
| 642 | }
|
| 643 |
|
| 644 | cleanup:
|
| 645 | if (!(bh && header == HDR(bh)))
|
| 646 | kfree(header);
|
| 647 | brelse(bh);
|
| 648 | up_write(&EXT2_I(inode)->xattr_sem);
|
| 649 |
|
| 650 | return error;
|
| 651 | }
|
| 652 |
|
| 653 | static void ext2_xattr_release_block(struct inode *inode,
|
| 654 | struct buffer_head *bh)
|
| 655 | {
|
| 656 | struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
|
| 657 |
|
| 658 | retry_ref:
|
| 659 | lock_buffer(bh);
|
| 660 | if (HDR(bh)->h_refcount == cpu_to_le32(1)) {
|
| 661 | __u32 hash = le32_to_cpu(HDR(bh)->h_hash);
|
| 662 | struct mb_cache_entry *oe;
|
| 663 |
|
| 664 | |
| 665 | * This must happen under buffer lock to properly
|
| 666 | * serialize with ext2_xattr_set() reusing the block.
|
| 667 |
|
| 668 | oe = mb_cache_entry_delete_or_get(ea_block_cache, hash,
|
| 669 | bh->b_blocknr);
|
| 670 | if (oe) {
|
| 671 | |
| 672 | * Someone is trying to reuse the block. Wait
|
| 673 | * and retry.
|
| 674 |
|
| 675 | unlock_buffer(bh);
|
| 676 | mb_cache_entry_wait_unused(oe);
|
| 677 | mb_cache_entry_put(ea_block_cache, oe);
|
| 678 | goto retry_ref;
|
| 679 | }
|
| 680 |
|
| 681 |
|
| 682 | ea_bdebug(bh, "freeing");
|
| 683 | ext2_free_blocks(inode, bh->b_blocknr, 1);
|
| 684 | |
| 685 | * need to duplicate the buffer before.
|
| 686 | get_bh(bh);
|
| 687 | bforget(bh);
|
| 688 | unlock_buffer(bh);
|
| 689 | } else {
|
| 690 |
|
| 691 | le32_add_cpu(&HDR(bh)->h_refcount, -1);
|
| 692 | dquot_free_block(inode, 1);
|
| 693 | mark_buffer_dirty(bh);
|
| 694 | unlock_buffer(bh);
|
| 695 | ea_bdebug(bh, "refcount now=%d",
|
| 696 | le32_to_cpu(HDR(bh)->h_refcount));
|
| 697 | if (IS_SYNC(inode))
|
| 698 | sync_dirty_buffer(bh);
|
| 699 | }
|
| 700 | }
|
| 701 |
|
| 702 | |
| 703 | * Second half of ext2_xattr_set(): Update the file system.
|
| 704 |
|
| 705 | static int
|
| 706 | ext2_xattr_set2(struct inode *inode, struct buffer_head *old_bh,
|
| 707 | struct ext2_xattr_header *header)
|
| 708 | {
|
| 709 | struct super_block *sb = inode->i_sb;
|
| 710 | struct buffer_head *new_bh = NULL;
|
| 711 | int error;
|
| 712 | struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
|
| 713 |
|
| 714 | if (header) {
|
| 715 | new_bh = ext2_xattr_cache_find(inode, header);
|
| 716 | if (new_bh) {
|
| 717 |
|
| 718 | if (new_bh == old_bh) {
|
| 719 | ea_bdebug(new_bh, "keeping this block");
|
| 720 | } else {
|
| 721 | |
| 722 | the inode.
|
| 723 | ea_bdebug(new_bh, "reusing block");
|
| 724 |
|
| 725 | error = dquot_alloc_block(inode, 1);
|
| 726 | if (error) {
|
| 727 | unlock_buffer(new_bh);
|
| 728 | goto cleanup;
|
| 729 | }
|
| 730 | le32_add_cpu(&HDR(new_bh)->h_refcount, 1);
|
| 731 | ea_bdebug(new_bh, "refcount now=%d",
|
| 732 | le32_to_cpu(HDR(new_bh)->h_refcount));
|
| 733 | }
|
| 734 | unlock_buffer(new_bh);
|
| 735 | } else if (old_bh && header == HDR(old_bh)) {
|
| 736 | |
| 737 | don't need to change the reference count.
|
| 738 | new_bh = old_bh;
|
| 739 | get_bh(new_bh);
|
| 740 | ext2_xattr_cache_insert(ea_block_cache, new_bh);
|
| 741 | } else {
|
| 742 |
|
| 743 | ext2_fsblk_t goal = ext2_group_first_block_no(sb,
|
| 744 | EXT2_I(inode)->i_block_group);
|
| 745 | unsigned long count = 1;
|
| 746 | ext2_fsblk_t block = ext2_new_blocks(inode, goal,
|
| 747 | &count, &error,
|
| 748 | EXT2_ALLOC_NORESERVE);
|
| 749 | if (error)
|
| 750 | goto cleanup;
|
| 751 | ea_idebug(inode, "creating block %lu", block);
|
| 752 |
|
| 753 | new_bh = sb_getblk(sb, block);
|
| 754 | if (unlikely(!new_bh)) {
|
| 755 | ext2_free_blocks(inode, block, 1);
|
| 756 | mark_inode_dirty(inode);
|
| 757 | error = -ENOMEM;
|
| 758 | goto cleanup;
|
| 759 | }
|
| 760 | lock_buffer(new_bh);
|
| 761 | memcpy(new_bh->b_data, header, new_bh->b_size);
|
| 762 | set_buffer_uptodate(new_bh);
|
| 763 | unlock_buffer(new_bh);
|
| 764 | ext2_xattr_cache_insert(ea_block_cache, new_bh);
|
| 765 |
|
| 766 | ext2_xattr_update_super_block(sb);
|
| 767 | }
|
| 768 | mark_buffer_dirty(new_bh);
|
| 769 | if (IS_SYNC(inode)) {
|
| 770 | sync_dirty_buffer(new_bh);
|
| 771 | error = -EIO;
|
| 772 | if (buffer_write_io_error(new_bh))
|
| 773 | goto cleanup;
|
| 774 | }
|
| 775 | }
|
| 776 |
|
| 777 |
|
| 778 | EXT2_I(inode)->i_file_acl = new_bh ? new_bh->b_blocknr : 0;
|
| 779 | inode_set_ctime_current(inode);
|
| 780 | mark_inode_dirty(inode);
|
| 781 | if (IS_SYNC(inode)) {
|
| 782 | error = sync_inode_metadata(inode, 1);
|
| 783 | |
| 784 | * Inode writeout failed. Backing everything out is complex so
|
| 785 | * let's just leave it for e2fsck to cleanup the mess.
|
| 786 |
|
| 787 | if (error)
|
| 788 | goto cleanup;
|
| 789 | }
|
| 790 |
|
| 791 | error = 0;
|
| 792 | if (old_bh && old_bh != new_bh) {
|
| 793 | |
| 794 | * If there was an old block and we are no longer using it,
|
| 795 | * release the old block.
|
| 796 |
|
| 797 | ext2_xattr_release_block(inode, old_bh);
|
| 798 | }
|
| 799 |
|
| 800 | cleanup:
|
| 801 | brelse(new_bh);
|
| 802 |
|
| 803 | return error;
|
| 804 | }
|
| 805 |
|
| 806 | |
| 807 | * ext2_xattr_delete_inode()
|
| 808 | *
|
| 809 | * Free extended attribute resources associated with this inode. This
|
| 810 | * is called immediately before an inode is freed.
|
| 811 |
|
| 812 | void
|
| 813 | ext2_xattr_delete_inode(struct inode *inode)
|
| 814 | {
|
| 815 | struct buffer_head *bh = NULL;
|
| 816 | struct ext2_sb_info *sbi = EXT2_SB(inode->i_sb);
|
| 817 |
|
| 818 | |
| 819 | * We are the only ones holding inode reference. The xattr_sem should
|
| 820 | * better be unlocked! We could as well just not acquire xattr_sem at
|
| 821 | * all but this makes the code more futureproof. OTOH we need trylock
|
| 822 | * here to avoid false-positive warning from lockdep about reclaim
|
| 823 | * circular dependency.
|
| 824 |
|
| 825 | if (WARN_ON_ONCE(!down_write_trylock(&EXT2_I(inode)->xattr_sem)))
|
| 826 | return;
|
| 827 | if (!EXT2_I(inode)->i_file_acl)
|
| 828 | goto cleanup;
|
| 829 |
|
| 830 | if (!ext2_data_block_valid(sbi, EXT2_I(inode)->i_file_acl, 1)) {
|
| 831 | ext2_error(inode->i_sb, "ext2_xattr_delete_inode",
|
| 832 | "inode %llu: xattr block %d is out of data blocks range",
|
| 833 | inode->i_ino, EXT2_I(inode)->i_file_acl);
|
| 834 | goto cleanup;
|
| 835 | }
|
| 836 |
|
| 837 | bh = sb_bread(inode->i_sb, EXT2_I(inode)->i_file_acl);
|
| 838 | if (!bh) {
|
| 839 | ext2_error(inode->i_sb, "ext2_xattr_delete_inode",
|
| 840 | "inode %llu: block %d read error", inode->i_ino,
|
| 841 | EXT2_I(inode)->i_file_acl);
|
| 842 | goto cleanup;
|
| 843 | }
|
| 844 | ea_bdebug(bh, "b_count=%d", atomic_read(&(bh->b_count)));
|
| 845 | if (!ext2_xattr_header_valid(HDR(bh))) {
|
| 846 | ext2_error(inode->i_sb, "ext2_xattr_delete_inode",
|
| 847 | "inode %llu: bad block %d", inode->i_ino,
|
| 848 | EXT2_I(inode)->i_file_acl);
|
| 849 | goto cleanup;
|
| 850 | }
|
| 851 | ext2_xattr_release_block(inode, bh);
|
| 852 | EXT2_I(inode)->i_file_acl = 0;
|
| 853 |
|
| 854 | cleanup:
|
| 855 | brelse(bh);
|
| 856 | up_write(&EXT2_I(inode)->xattr_sem);
|
| 857 | }
|
| 858 |
|
| 859 | |
| 860 | * ext2_xattr_cache_insert()
|
| 861 | *
|
| 862 | * Create a new entry in the extended attribute cache, and insert
|
| 863 | * it unless such an entry is already in the cache.
|
| 864 | *
|
| 865 | * Returns 0, or a negative error number on failure.
|
| 866 |
|
| 867 | static int
|
| 868 | ext2_xattr_cache_insert(struct mb_cache *cache, struct buffer_head *bh)
|
| 869 | {
|
| 870 | __u32 hash = le32_to_cpu(HDR(bh)->h_hash);
|
| 871 | int error;
|
| 872 |
|
| 873 | error = mb_cache_entry_create(cache, GFP_KERNEL, hash, bh->b_blocknr,
|
| 874 | true);
|
| 875 | if (error) {
|
| 876 | if (error == -EBUSY) {
|
| 877 | ea_bdebug(bh, "already in cache");
|
| 878 | error = 0;
|
| 879 | }
|
| 880 | } else
|
| 881 | ea_bdebug(bh, "inserting [%x]", (int)hash);
|
| 882 | return error;
|
| 883 | }
|
| 884 |
|
| 885 | |
| 886 | * ext2_xattr_cmp()
|
| 887 | *
|
| 888 | * Compare two extended attribute blocks for equality.
|
| 889 | *
|
| 890 | * Returns 0 if the blocks are equal, 1 if they differ, and
|
| 891 | * a negative error number on errors.
|
| 892 |
|
| 893 | static int
|
| 894 | ext2_xattr_cmp(struct ext2_xattr_header *header1,
|
| 895 | struct ext2_xattr_header *header2)
|
| 896 | {
|
| 897 | struct ext2_xattr_entry *entry1, *entry2;
|
| 898 |
|
| 899 | entry1 = ENTRY(header1+1);
|
| 900 | entry2 = ENTRY(header2+1);
|
| 901 | while (!IS_LAST_ENTRY(entry1)) {
|
| 902 | if (IS_LAST_ENTRY(entry2))
|
| 903 | return 1;
|
| 904 | if (entry1->e_hash != entry2->e_hash ||
|
| 905 | entry1->e_name_index != entry2->e_name_index ||
|
| 906 | entry1->e_name_len != entry2->e_name_len ||
|
| 907 | entry1->e_value_size != entry2->e_value_size ||
|
| 908 | memcmp(entry1->e_name, entry2->e_name, entry1->e_name_len))
|
| 909 | return 1;
|
| 910 | if (entry1->e_value_block != 0 || entry2->e_value_block != 0)
|
| 911 | return -EIO;
|
| 912 | if (memcmp((char *)header1 + le16_to_cpu(entry1->e_value_offs),
|
| 913 | (char *)header2 + le16_to_cpu(entry2->e_value_offs),
|
| 914 | le32_to_cpu(entry1->e_value_size)))
|
| 915 | return 1;
|
| 916 |
|
| 917 | entry1 = EXT2_XATTR_NEXT(entry1);
|
| 918 | entry2 = EXT2_XATTR_NEXT(entry2);
|
| 919 | }
|
| 920 | if (!IS_LAST_ENTRY(entry2))
|
| 921 | return 1;
|
| 922 | return 0;
|
| 923 | }
|
| 924 |
|
| 925 | |
| 926 | * ext2_xattr_cache_find()
|
| 927 | *
|
| 928 | * Find an identical extended attribute block.
|
| 929 | *
|
| 930 | * Returns a locked buffer head to the block found, or NULL if such
|
| 931 | * a block was not found or an error occurred.
|
| 932 |
|
| 933 | static struct buffer_head *
|
| 934 | ext2_xattr_cache_find(struct inode *inode, struct ext2_xattr_header *header)
|
| 935 | {
|
| 936 | __u32 hash = le32_to_cpu(header->h_hash);
|
| 937 | struct mb_cache_entry *ce;
|
| 938 | struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
|
| 939 |
|
| 940 | if (!header->h_hash)
|
| 941 | return NULL;
|
| 942 | ea_idebug(inode, "looking for cached blocks [%x]", (int)hash);
|
| 943 |
|
| 944 | ce = mb_cache_entry_find_first(ea_block_cache, hash);
|
| 945 | while (ce) {
|
| 946 | struct buffer_head *bh;
|
| 947 |
|
| 948 | bh = sb_bread(inode->i_sb, ce->e_value);
|
| 949 | if (!bh) {
|
| 950 | ext2_error(inode->i_sb, "ext2_xattr_cache_find",
|
| 951 | "inode %llu: block %ld read error",
|
| 952 | inode->i_ino, (unsigned long) ce->e_value);
|
| 953 | } else {
|
| 954 | lock_buffer(bh);
|
| 955 | if (le32_to_cpu(HDR(bh)->h_refcount) >
|
| 956 | EXT2_XATTR_REFCOUNT_MAX) {
|
| 957 | ea_idebug(inode, "block %ld refcount %d>%d",
|
| 958 | (unsigned long) ce->e_value,
|
| 959 | le32_to_cpu(HDR(bh)->h_refcount),
|
| 960 | EXT2_XATTR_REFCOUNT_MAX);
|
| 961 | } else if (!ext2_xattr_cmp(header, HDR(bh))) {
|
| 962 | ea_bdebug(bh, "b_count=%d",
|
| 963 | atomic_read(&(bh->b_count)));
|
| 964 | mb_cache_entry_touch(ea_block_cache, ce);
|
| 965 | mb_cache_entry_put(ea_block_cache, ce);
|
| 966 | return bh;
|
| 967 | }
|
| 968 | unlock_buffer(bh);
|
| 969 | brelse(bh);
|
| 970 | }
|
| 971 | ce = mb_cache_entry_find_next(ea_block_cache, ce);
|
| 972 | }
|
| 973 | return NULL;
|
| 974 | }
|
| 975 |
|
| 976 | #define NAME_HASH_SHIFT 5
|
| 977 | #define VALUE_HASH_SHIFT 16
|
| 978 |
|
| 979 | |
| 980 | * ext2_xattr_hash_entry()
|
| 981 | *
|
| 982 | * Compute the hash of an extended attribute.
|
| 983 |
|
| 984 | static inline void ext2_xattr_hash_entry(struct ext2_xattr_header *header,
|
| 985 | struct ext2_xattr_entry *entry)
|
| 986 | {
|
| 987 | __u32 hash = 0;
|
| 988 | char *name = entry->e_name;
|
| 989 | int n;
|
| 990 |
|
| 991 | for (n=0; n < entry->e_name_len; n++) {
|
| 992 | hash = (hash << NAME_HASH_SHIFT) ^
|
| 993 | (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^
|
| 994 | *name++;
|
| 995 | }
|
| 996 |
|
| 997 | if (entry->e_value_block == 0 && entry->e_value_size != 0) {
|
| 998 | __le32 *value = (__le32 *)((char *)header +
|
| 999 | le16_to_cpu(entry->e_value_offs));
|
| 1000 | for (n = (le32_to_cpu(entry->e_value_size) +
|
| 1001 | EXT2_XATTR_ROUND) >> EXT2_XATTR_PAD_BITS; n; n--) {
|
| 1002 | hash = (hash << VALUE_HASH_SHIFT) ^
|
| 1003 | (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^
|
| 1004 | le32_to_cpu(*value++);
|
| 1005 | }
|
| 1006 | }
|
| 1007 | entry->e_hash = cpu_to_le32(hash);
|
| 1008 | }
|
| 1009 |
|
| 1010 | #undef NAME_HASH_SHIFT
|
| 1011 | #undef VALUE_HASH_SHIFT
|
| 1012 |
|
| 1013 | #define BLOCK_HASH_SHIFT 16
|
| 1014 |
|
| 1015 | |
| 1016 | * ext2_xattr_rehash()
|
| 1017 | *
|
| 1018 | * Re-compute the extended attribute hash value after an entry has changed.
|
| 1019 |
|
| 1020 | static void ext2_xattr_rehash(struct ext2_xattr_header *header,
|
| 1021 | struct ext2_xattr_entry *entry)
|
| 1022 | {
|
| 1023 | struct ext2_xattr_entry *here;
|
| 1024 | __u32 hash = 0;
|
| 1025 |
|
| 1026 | ext2_xattr_hash_entry(header, entry);
|
| 1027 | here = ENTRY(header+1);
|
| 1028 | while (!IS_LAST_ENTRY(here)) {
|
| 1029 | if (!here->e_hash) {
|
| 1030 |
|
| 1031 | hash = 0;
|
| 1032 | break;
|
| 1033 | }
|
| 1034 | hash = (hash << BLOCK_HASH_SHIFT) ^
|
| 1035 | (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^
|
| 1036 | le32_to_cpu(here->e_hash);
|
| 1037 | here = EXT2_XATTR_NEXT(here);
|
| 1038 | }
|
| 1039 | header->h_hash = cpu_to_le32(hash);
|
| 1040 | }
|
| 1041 |
|
| 1042 | #undef BLOCK_HASH_SHIFT
|
| 1043 |
|
| 1044 | #define HASH_BUCKET_BITS 10
|
| 1045 |
|
| 1046 | struct mb_cache *ext2_xattr_create_cache(void)
|
| 1047 | {
|
| 1048 | return mb_cache_create(HASH_BUCKET_BITS);
|
| 1049 | }
|
| 1050 |
|
| 1051 | void ext2_xattr_destroy_cache(struct mb_cache *cache)
|
| 1052 | {
|
| 1053 | if (cache)
|
| 1054 | mb_cache_destroy(cache);
|
| 1055 | }
|