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Commit | Line | Data |
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1da177e4 LT |
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 | * xattr consolidation Copyright (c) 2004 James Morris <jmorris@redhat.com>, | |
11 | * Red Hat Inc. | |
12 | * ea-in-inode support by Alex Tomas <alex@clusterfs.com> aka bzzz | |
13 | * and Andreas Gruenbacher <agruen@suse.de>. | |
14 | */ | |
15 | ||
16 | /* | |
17 | * Extended attributes are stored directly in inodes (on file systems with | |
18 | * inodes bigger than 128 bytes) and on additional disk blocks. The i_file_acl | |
19 | * field contains the block number if an inode uses an additional block. All | |
20 | * attributes must fit in the inode and one additional block. Blocks that | |
21 | * contain the identical set of attributes may be shared among several inodes. | |
22 | * Identical blocks are detected by keeping a cache of blocks that have | |
23 | * recently been accessed. | |
24 | * | |
25 | * The attributes in inodes and on blocks have a different header; the entries | |
26 | * are stored in the same format: | |
27 | * | |
28 | * +------------------+ | |
29 | * | header | | |
30 | * | entry 1 | | | |
31 | * | entry 2 | | growing downwards | |
32 | * | entry 3 | v | |
33 | * | four null bytes | | |
34 | * | . . . | | |
35 | * | value 1 | ^ | |
36 | * | value 3 | | growing upwards | |
37 | * | value 2 | | | |
38 | * +------------------+ | |
39 | * | |
40 | * The header is followed by multiple entry descriptors. In disk blocks, the | |
41 | * entry descriptors are kept sorted. In inodes, they are unsorted. The | |
42 | * attribute values are aligned to the end of the block in no specific order. | |
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 can change. Multiple writers to the same block are synchronized | |
50 | * by the buffer lock. | |
51 | */ | |
52 | ||
4613ad18 | 53 | #include "ext3.h" |
1da177e4 LT |
54 | #include <linux/mbcache.h> |
55 | #include <linux/quotaops.h> | |
1da177e4 LT |
56 | #include "xattr.h" |
57 | #include "acl.h" | |
58 | ||
59 | #define BHDR(bh) ((struct ext3_xattr_header *)((bh)->b_data)) | |
60 | #define ENTRY(ptr) ((struct ext3_xattr_entry *)(ptr)) | |
61 | #define BFIRST(bh) ENTRY(BHDR(bh)+1) | |
62 | #define IS_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0) | |
63 | ||
64 | #define IHDR(inode, raw_inode) \ | |
65 | ((struct ext3_xattr_ibody_header *) \ | |
66 | ((void *)raw_inode + \ | |
67 | EXT3_GOOD_OLD_INODE_SIZE + \ | |
68 | EXT3_I(inode)->i_extra_isize)) | |
69 | #define IFIRST(hdr) ((struct ext3_xattr_entry *)((hdr)+1)) | |
70 | ||
71 | #ifdef EXT3_XATTR_DEBUG | |
72 | # define ea_idebug(inode, f...) do { \ | |
eee194e7 | 73 | printk(KERN_DEBUG "inode %s:%lu: ", \ |
1da177e4 LT |
74 | inode->i_sb->s_id, inode->i_ino); \ |
75 | printk(f); \ | |
76 | printk("\n"); \ | |
77 | } while (0) | |
78 | # define ea_bdebug(bh, f...) do { \ | |
79 | char b[BDEVNAME_SIZE]; \ | |
80 | printk(KERN_DEBUG "block %s:%lu: ", \ | |
81 | bdevname(bh->b_bdev, b), \ | |
82 | (unsigned long) bh->b_blocknr); \ | |
83 | printk(f); \ | |
84 | printk("\n"); \ | |
85 | } while (0) | |
86 | #else | |
87 | # define ea_idebug(f...) | |
88 | # define ea_bdebug(f...) | |
89 | #endif | |
90 | ||
91 | static void ext3_xattr_cache_insert(struct buffer_head *); | |
92 | static struct buffer_head *ext3_xattr_cache_find(struct inode *, | |
93 | struct ext3_xattr_header *, | |
94 | struct mb_cache_entry **); | |
95 | static void ext3_xattr_rehash(struct ext3_xattr_header *, | |
96 | struct ext3_xattr_entry *); | |
431547b3 | 97 | static int ext3_xattr_list(struct dentry *dentry, char *buffer, |
15633005 | 98 | size_t buffer_size); |
1da177e4 LT |
99 | |
100 | static struct mb_cache *ext3_xattr_cache; | |
101 | ||
d1f21049 | 102 | static const struct xattr_handler *ext3_xattr_handler_map[] = { |
1da177e4 LT |
103 | [EXT3_XATTR_INDEX_USER] = &ext3_xattr_user_handler, |
104 | #ifdef CONFIG_EXT3_FS_POSIX_ACL | |
64e178a7 CH |
105 | [EXT3_XATTR_INDEX_POSIX_ACL_ACCESS] = &posix_acl_access_xattr_handler, |
106 | [EXT3_XATTR_INDEX_POSIX_ACL_DEFAULT] = &posix_acl_default_xattr_handler, | |
1da177e4 LT |
107 | #endif |
108 | [EXT3_XATTR_INDEX_TRUSTED] = &ext3_xattr_trusted_handler, | |
109 | #ifdef CONFIG_EXT3_FS_SECURITY | |
110 | [EXT3_XATTR_INDEX_SECURITY] = &ext3_xattr_security_handler, | |
111 | #endif | |
112 | }; | |
113 | ||
d1f21049 | 114 | const struct xattr_handler *ext3_xattr_handlers[] = { |
1da177e4 LT |
115 | &ext3_xattr_user_handler, |
116 | &ext3_xattr_trusted_handler, | |
117 | #ifdef CONFIG_EXT3_FS_POSIX_ACL | |
64e178a7 CH |
118 | &posix_acl_access_xattr_handler, |
119 | &posix_acl_default_xattr_handler, | |
1da177e4 LT |
120 | #endif |
121 | #ifdef CONFIG_EXT3_FS_SECURITY | |
122 | &ext3_xattr_security_handler, | |
123 | #endif | |
124 | NULL | |
125 | }; | |
126 | ||
d1f21049 | 127 | static inline const struct xattr_handler * |
1da177e4 LT |
128 | ext3_xattr_handler(int name_index) |
129 | { | |
d1f21049 | 130 | const struct xattr_handler *handler = NULL; |
1da177e4 LT |
131 | |
132 | if (name_index > 0 && name_index < ARRAY_SIZE(ext3_xattr_handler_map)) | |
133 | handler = ext3_xattr_handler_map[name_index]; | |
134 | return handler; | |
135 | } | |
136 | ||
137 | /* | |
138 | * Inode operation listxattr() | |
139 | * | |
2b0143b5 | 140 | * d_inode(dentry)->i_mutex: don't care |
1da177e4 LT |
141 | */ |
142 | ssize_t | |
143 | ext3_listxattr(struct dentry *dentry, char *buffer, size_t size) | |
144 | { | |
431547b3 | 145 | return ext3_xattr_list(dentry, buffer, size); |
1da177e4 LT |
146 | } |
147 | ||
148 | static int | |
149 | ext3_xattr_check_names(struct ext3_xattr_entry *entry, void *end) | |
150 | { | |
151 | while (!IS_LAST_ENTRY(entry)) { | |
152 | struct ext3_xattr_entry *next = EXT3_XATTR_NEXT(entry); | |
153 | if ((void *)next >= end) | |
154 | return -EIO; | |
155 | entry = next; | |
156 | } | |
157 | return 0; | |
158 | } | |
159 | ||
160 | static inline int | |
161 | ext3_xattr_check_block(struct buffer_head *bh) | |
162 | { | |
163 | int error; | |
164 | ||
165 | if (BHDR(bh)->h_magic != cpu_to_le32(EXT3_XATTR_MAGIC) || | |
166 | BHDR(bh)->h_blocks != cpu_to_le32(1)) | |
167 | return -EIO; | |
168 | error = ext3_xattr_check_names(BFIRST(bh), bh->b_data + bh->b_size); | |
169 | return error; | |
170 | } | |
171 | ||
172 | static inline int | |
173 | ext3_xattr_check_entry(struct ext3_xattr_entry *entry, size_t size) | |
174 | { | |
175 | size_t value_size = le32_to_cpu(entry->e_value_size); | |
176 | ||
177 | if (entry->e_value_block != 0 || value_size > size || | |
178 | le16_to_cpu(entry->e_value_offs) + value_size > size) | |
179 | return -EIO; | |
180 | return 0; | |
181 | } | |
182 | ||
183 | static int | |
184 | ext3_xattr_find_entry(struct ext3_xattr_entry **pentry, int name_index, | |
185 | const char *name, size_t size, int sorted) | |
186 | { | |
187 | struct ext3_xattr_entry *entry; | |
188 | size_t name_len; | |
189 | int cmp = 1; | |
190 | ||
191 | if (name == NULL) | |
192 | return -EINVAL; | |
193 | name_len = strlen(name); | |
194 | entry = *pentry; | |
195 | for (; !IS_LAST_ENTRY(entry); entry = EXT3_XATTR_NEXT(entry)) { | |
196 | cmp = name_index - entry->e_name_index; | |
197 | if (!cmp) | |
198 | cmp = name_len - entry->e_name_len; | |
199 | if (!cmp) | |
200 | cmp = memcmp(name, entry->e_name, name_len); | |
201 | if (cmp <= 0 && (sorted || cmp == 0)) | |
202 | break; | |
203 | } | |
204 | *pentry = entry; | |
205 | if (!cmp && ext3_xattr_check_entry(entry, size)) | |
206 | return -EIO; | |
207 | return cmp ? -ENODATA : 0; | |
208 | } | |
209 | ||
381be254 | 210 | static int |
1da177e4 LT |
211 | ext3_xattr_block_get(struct inode *inode, int name_index, const char *name, |
212 | void *buffer, size_t buffer_size) | |
213 | { | |
214 | struct buffer_head *bh = NULL; | |
215 | struct ext3_xattr_entry *entry; | |
216 | size_t size; | |
217 | int error; | |
218 | ||
219 | ea_idebug(inode, "name=%d.%s, buffer=%p, buffer_size=%ld", | |
220 | name_index, name, buffer, (long)buffer_size); | |
221 | ||
222 | error = -ENODATA; | |
223 | if (!EXT3_I(inode)->i_file_acl) | |
224 | goto cleanup; | |
1c2bf374 | 225 | ea_idebug(inode, "reading block %u", EXT3_I(inode)->i_file_acl); |
1da177e4 LT |
226 | bh = sb_bread(inode->i_sb, EXT3_I(inode)->i_file_acl); |
227 | if (!bh) | |
228 | goto cleanup; | |
229 | ea_bdebug(bh, "b_count=%d, refcount=%d", | |
230 | atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount)); | |
231 | if (ext3_xattr_check_block(bh)) { | |
e05b6b52 | 232 | bad_block: ext3_error(inode->i_sb, __func__, |
eee194e7 | 233 | "inode %lu: bad block "E3FSBLK, inode->i_ino, |
1da177e4 LT |
234 | EXT3_I(inode)->i_file_acl); |
235 | error = -EIO; | |
236 | goto cleanup; | |
237 | } | |
238 | ext3_xattr_cache_insert(bh); | |
239 | entry = BFIRST(bh); | |
240 | error = ext3_xattr_find_entry(&entry, name_index, name, bh->b_size, 1); | |
241 | if (error == -EIO) | |
242 | goto bad_block; | |
243 | if (error) | |
244 | goto cleanup; | |
245 | size = le32_to_cpu(entry->e_value_size); | |
246 | if (buffer) { | |
247 | error = -ERANGE; | |
248 | if (size > buffer_size) | |
249 | goto cleanup; | |
250 | memcpy(buffer, bh->b_data + le16_to_cpu(entry->e_value_offs), | |
251 | size); | |
252 | } | |
253 | error = size; | |
254 | ||
255 | cleanup: | |
256 | brelse(bh); | |
257 | return error; | |
258 | } | |
259 | ||
260 | static int | |
261 | ext3_xattr_ibody_get(struct inode *inode, int name_index, const char *name, | |
262 | void *buffer, size_t buffer_size) | |
263 | { | |
264 | struct ext3_xattr_ibody_header *header; | |
265 | struct ext3_xattr_entry *entry; | |
266 | struct ext3_inode *raw_inode; | |
267 | struct ext3_iloc iloc; | |
268 | size_t size; | |
269 | void *end; | |
270 | int error; | |
271 | ||
9df93939 | 272 | if (!ext3_test_inode_state(inode, EXT3_STATE_XATTR)) |
1da177e4 LT |
273 | return -ENODATA; |
274 | error = ext3_get_inode_loc(inode, &iloc); | |
275 | if (error) | |
276 | return error; | |
277 | raw_inode = ext3_raw_inode(&iloc); | |
278 | header = IHDR(inode, raw_inode); | |
279 | entry = IFIRST(header); | |
280 | end = (void *)raw_inode + EXT3_SB(inode->i_sb)->s_inode_size; | |
281 | error = ext3_xattr_check_names(entry, end); | |
282 | if (error) | |
283 | goto cleanup; | |
284 | error = ext3_xattr_find_entry(&entry, name_index, name, | |
285 | end - (void *)entry, 0); | |
286 | if (error) | |
287 | goto cleanup; | |
288 | size = le32_to_cpu(entry->e_value_size); | |
289 | if (buffer) { | |
290 | error = -ERANGE; | |
291 | if (size > buffer_size) | |
292 | goto cleanup; | |
293 | memcpy(buffer, (void *)IFIRST(header) + | |
294 | le16_to_cpu(entry->e_value_offs), size); | |
295 | } | |
296 | error = size; | |
297 | ||
298 | cleanup: | |
299 | brelse(iloc.bh); | |
300 | return error; | |
301 | } | |
302 | ||
303 | /* | |
304 | * ext3_xattr_get() | |
305 | * | |
306 | * Copy an extended attribute into the buffer | |
307 | * provided, or compute the buffer size required. | |
308 | * Buffer is NULL to compute the size of the buffer required. | |
309 | * | |
310 | * Returns a negative error number on failure, or the number of bytes | |
311 | * used / required on success. | |
312 | */ | |
313 | int | |
314 | ext3_xattr_get(struct inode *inode, int name_index, const char *name, | |
315 | void *buffer, size_t buffer_size) | |
316 | { | |
317 | int error; | |
318 | ||
319 | down_read(&EXT3_I(inode)->xattr_sem); | |
320 | error = ext3_xattr_ibody_get(inode, name_index, name, buffer, | |
321 | buffer_size); | |
322 | if (error == -ENODATA) | |
323 | error = ext3_xattr_block_get(inode, name_index, name, buffer, | |
324 | buffer_size); | |
325 | up_read(&EXT3_I(inode)->xattr_sem); | |
326 | return error; | |
327 | } | |
328 | ||
329 | static int | |
431547b3 | 330 | ext3_xattr_list_entries(struct dentry *dentry, struct ext3_xattr_entry *entry, |
1da177e4 LT |
331 | char *buffer, size_t buffer_size) |
332 | { | |
333 | size_t rest = buffer_size; | |
334 | ||
335 | for (; !IS_LAST_ENTRY(entry); entry = EXT3_XATTR_NEXT(entry)) { | |
d1f21049 | 336 | const struct xattr_handler *handler = |
1da177e4 LT |
337 | ext3_xattr_handler(entry->e_name_index); |
338 | ||
339 | if (handler) { | |
431547b3 | 340 | size_t size = handler->list(dentry, buffer, rest, |
1da177e4 | 341 | entry->e_name, |
431547b3 CH |
342 | entry->e_name_len, |
343 | handler->flags); | |
1da177e4 LT |
344 | if (buffer) { |
345 | if (size > rest) | |
346 | return -ERANGE; | |
347 | buffer += size; | |
348 | } | |
349 | rest -= size; | |
350 | } | |
351 | } | |
352 | return buffer_size - rest; | |
353 | } | |
354 | ||
381be254 | 355 | static int |
431547b3 | 356 | ext3_xattr_block_list(struct dentry *dentry, char *buffer, size_t buffer_size) |
1da177e4 | 357 | { |
2b0143b5 | 358 | struct inode *inode = d_inode(dentry); |
1da177e4 LT |
359 | struct buffer_head *bh = NULL; |
360 | int error; | |
361 | ||
362 | ea_idebug(inode, "buffer=%p, buffer_size=%ld", | |
363 | buffer, (long)buffer_size); | |
364 | ||
365 | error = 0; | |
366 | if (!EXT3_I(inode)->i_file_acl) | |
367 | goto cleanup; | |
1c2bf374 | 368 | ea_idebug(inode, "reading block %u", EXT3_I(inode)->i_file_acl); |
1da177e4 LT |
369 | bh = sb_bread(inode->i_sb, EXT3_I(inode)->i_file_acl); |
370 | error = -EIO; | |
371 | if (!bh) | |
372 | goto cleanup; | |
373 | ea_bdebug(bh, "b_count=%d, refcount=%d", | |
374 | atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount)); | |
375 | if (ext3_xattr_check_block(bh)) { | |
e05b6b52 | 376 | ext3_error(inode->i_sb, __func__, |
eee194e7 | 377 | "inode %lu: bad block "E3FSBLK, inode->i_ino, |
1da177e4 LT |
378 | EXT3_I(inode)->i_file_acl); |
379 | error = -EIO; | |
380 | goto cleanup; | |
381 | } | |
382 | ext3_xattr_cache_insert(bh); | |
431547b3 | 383 | error = ext3_xattr_list_entries(dentry, BFIRST(bh), buffer, buffer_size); |
1da177e4 LT |
384 | |
385 | cleanup: | |
386 | brelse(bh); | |
387 | ||
388 | return error; | |
389 | } | |
390 | ||
391 | static int | |
431547b3 | 392 | ext3_xattr_ibody_list(struct dentry *dentry, char *buffer, size_t buffer_size) |
1da177e4 | 393 | { |
2b0143b5 | 394 | struct inode *inode = d_inode(dentry); |
1da177e4 LT |
395 | struct ext3_xattr_ibody_header *header; |
396 | struct ext3_inode *raw_inode; | |
397 | struct ext3_iloc iloc; | |
398 | void *end; | |
399 | int error; | |
400 | ||
9df93939 | 401 | if (!ext3_test_inode_state(inode, EXT3_STATE_XATTR)) |
1da177e4 LT |
402 | return 0; |
403 | error = ext3_get_inode_loc(inode, &iloc); | |
404 | if (error) | |
405 | return error; | |
406 | raw_inode = ext3_raw_inode(&iloc); | |
407 | header = IHDR(inode, raw_inode); | |
408 | end = (void *)raw_inode + EXT3_SB(inode->i_sb)->s_inode_size; | |
409 | error = ext3_xattr_check_names(IFIRST(header), end); | |
410 | if (error) | |
411 | goto cleanup; | |
431547b3 | 412 | error = ext3_xattr_list_entries(dentry, IFIRST(header), |
1da177e4 LT |
413 | buffer, buffer_size); |
414 | ||
415 | cleanup: | |
416 | brelse(iloc.bh); | |
417 | return error; | |
418 | } | |
419 | ||
420 | /* | |
421 | * ext3_xattr_list() | |
422 | * | |
423 | * Copy a list of attribute names into the buffer | |
424 | * provided, or compute the buffer size required. | |
425 | * Buffer is NULL to compute the size of the buffer required. | |
426 | * | |
427 | * Returns a negative error number on failure, or the number of bytes | |
428 | * used / required on success. | |
429 | */ | |
15633005 | 430 | static int |
431547b3 | 431 | ext3_xattr_list(struct dentry *dentry, char *buffer, size_t buffer_size) |
1da177e4 LT |
432 | { |
433 | int i_error, b_error; | |
434 | ||
2b0143b5 | 435 | down_read(&EXT3_I(d_inode(dentry))->xattr_sem); |
431547b3 | 436 | i_error = ext3_xattr_ibody_list(dentry, buffer, buffer_size); |
1da177e4 LT |
437 | if (i_error < 0) { |
438 | b_error = 0; | |
439 | } else { | |
440 | if (buffer) { | |
441 | buffer += i_error; | |
442 | buffer_size -= i_error; | |
443 | } | |
431547b3 | 444 | b_error = ext3_xattr_block_list(dentry, buffer, buffer_size); |
1da177e4 LT |
445 | if (b_error < 0) |
446 | i_error = 0; | |
447 | } | |
2b0143b5 | 448 | up_read(&EXT3_I(d_inode(dentry))->xattr_sem); |
1da177e4 LT |
449 | return i_error + b_error; |
450 | } | |
451 | ||
452 | /* | |
453 | * If the EXT3_FEATURE_COMPAT_EXT_ATTR feature of this file system is | |
454 | * not set, set it. | |
455 | */ | |
456 | static void ext3_xattr_update_super_block(handle_t *handle, | |
457 | struct super_block *sb) | |
458 | { | |
459 | if (EXT3_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_EXT_ATTR)) | |
460 | return; | |
461 | ||
1da177e4 | 462 | if (ext3_journal_get_write_access(handle, EXT3_SB(sb)->s_sbh) == 0) { |
ed2908f3 | 463 | EXT3_SET_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_EXT_ATTR); |
1da177e4 LT |
464 | ext3_journal_dirty_metadata(handle, EXT3_SB(sb)->s_sbh); |
465 | } | |
1da177e4 LT |
466 | } |
467 | ||
468 | /* | |
469 | * Release the xattr block BH: If the reference count is > 1, decrement | |
470 | * it; otherwise free the block. | |
471 | */ | |
472 | static void | |
473 | ext3_xattr_release_block(handle_t *handle, struct inode *inode, | |
474 | struct buffer_head *bh) | |
475 | { | |
476 | struct mb_cache_entry *ce = NULL; | |
8a2bfdcb | 477 | int error = 0; |
1da177e4 LT |
478 | |
479 | ce = mb_cache_entry_get(ext3_xattr_cache, bh->b_bdev, bh->b_blocknr); | |
8a2bfdcb MC |
480 | error = ext3_journal_get_write_access(handle, bh); |
481 | if (error) | |
482 | goto out; | |
483 | ||
484 | lock_buffer(bh); | |
485 | ||
1da177e4 LT |
486 | if (BHDR(bh)->h_refcount == cpu_to_le32(1)) { |
487 | ea_bdebug(bh, "refcount now=0; freeing"); | |
488 | if (ce) | |
489 | mb_cache_entry_free(ce); | |
490 | ext3_free_blocks(handle, inode, bh->b_blocknr, 1); | |
491 | get_bh(bh); | |
492 | ext3_forget(handle, 1, inode, bh, bh->b_blocknr); | |
493 | } else { | |
50e8a289 | 494 | le32_add_cpu(&BHDR(bh)->h_refcount, -1); |
8a2bfdcb | 495 | error = ext3_journal_dirty_metadata(handle, bh); |
105fd108 AM |
496 | if (IS_SYNC(inode)) |
497 | handle->h_sync = 1; | |
5dd4056d | 498 | dquot_free_block(inode, 1); |
8a2bfdcb MC |
499 | ea_bdebug(bh, "refcount now=%d; releasing", |
500 | le32_to_cpu(BHDR(bh)->h_refcount)); | |
1da177e4 LT |
501 | if (ce) |
502 | mb_cache_entry_release(ce); | |
503 | } | |
8a2bfdcb MC |
504 | unlock_buffer(bh); |
505 | out: | |
506 | ext3_std_error(inode->i_sb, error); | |
507 | return; | |
1da177e4 LT |
508 | } |
509 | ||
510 | struct ext3_xattr_info { | |
511 | int name_index; | |
512 | const char *name; | |
513 | const void *value; | |
514 | size_t value_len; | |
515 | }; | |
516 | ||
517 | struct ext3_xattr_search { | |
518 | struct ext3_xattr_entry *first; | |
519 | void *base; | |
520 | void *end; | |
521 | struct ext3_xattr_entry *here; | |
522 | int not_found; | |
523 | }; | |
524 | ||
525 | static int | |
526 | ext3_xattr_set_entry(struct ext3_xattr_info *i, struct ext3_xattr_search *s) | |
527 | { | |
528 | struct ext3_xattr_entry *last; | |
529 | size_t free, min_offs = s->end - s->base, name_len = strlen(i->name); | |
530 | ||
531 | /* Compute min_offs and last. */ | |
532 | last = s->first; | |
533 | for (; !IS_LAST_ENTRY(last); last = EXT3_XATTR_NEXT(last)) { | |
534 | if (!last->e_value_block && last->e_value_size) { | |
535 | size_t offs = le16_to_cpu(last->e_value_offs); | |
536 | if (offs < min_offs) | |
537 | min_offs = offs; | |
538 | } | |
539 | } | |
540 | free = min_offs - ((void *)last - s->base) - sizeof(__u32); | |
541 | if (!s->not_found) { | |
542 | if (!s->here->e_value_block && s->here->e_value_size) { | |
543 | size_t size = le32_to_cpu(s->here->e_value_size); | |
544 | free += EXT3_XATTR_SIZE(size); | |
545 | } | |
546 | free += EXT3_XATTR_LEN(name_len); | |
547 | } | |
548 | if (i->value) { | |
78c3eb3c | 549 | if (free < EXT3_XATTR_LEN(name_len) + |
1da177e4 LT |
550 | EXT3_XATTR_SIZE(i->value_len)) |
551 | return -ENOSPC; | |
552 | } | |
553 | ||
554 | if (i->value && s->not_found) { | |
555 | /* Insert the new name. */ | |
556 | size_t size = EXT3_XATTR_LEN(name_len); | |
557 | size_t rest = (void *)last - (void *)s->here + sizeof(__u32); | |
558 | memmove((void *)s->here + size, s->here, rest); | |
559 | memset(s->here, 0, size); | |
560 | s->here->e_name_index = i->name_index; | |
561 | s->here->e_name_len = name_len; | |
562 | memcpy(s->here->e_name, i->name, name_len); | |
563 | } else { | |
564 | if (!s->here->e_value_block && s->here->e_value_size) { | |
565 | void *first_val = s->base + min_offs; | |
566 | size_t offs = le16_to_cpu(s->here->e_value_offs); | |
567 | void *val = s->base + offs; | |
568 | size_t size = EXT3_XATTR_SIZE( | |
569 | le32_to_cpu(s->here->e_value_size)); | |
570 | ||
571 | if (i->value && size == EXT3_XATTR_SIZE(i->value_len)) { | |
572 | /* The old and the new value have the same | |
573 | size. Just replace. */ | |
574 | s->here->e_value_size = | |
575 | cpu_to_le32(i->value_len); | |
576 | memset(val + size - EXT3_XATTR_PAD, 0, | |
577 | EXT3_XATTR_PAD); /* Clear pad bytes. */ | |
578 | memcpy(val, i->value, i->value_len); | |
579 | return 0; | |
580 | } | |
581 | ||
582 | /* Remove the old value. */ | |
583 | memmove(first_val + size, first_val, val - first_val); | |
584 | memset(first_val, 0, size); | |
585 | s->here->e_value_size = 0; | |
586 | s->here->e_value_offs = 0; | |
587 | min_offs += size; | |
588 | ||
589 | /* Adjust all value offsets. */ | |
590 | last = s->first; | |
591 | while (!IS_LAST_ENTRY(last)) { | |
592 | size_t o = le16_to_cpu(last->e_value_offs); | |
593 | if (!last->e_value_block && | |
594 | last->e_value_size && o < offs) | |
595 | last->e_value_offs = | |
596 | cpu_to_le16(o + size); | |
597 | last = EXT3_XATTR_NEXT(last); | |
598 | } | |
599 | } | |
600 | if (!i->value) { | |
601 | /* Remove the old name. */ | |
602 | size_t size = EXT3_XATTR_LEN(name_len); | |
603 | last = ENTRY((void *)last - size); | |
604 | memmove(s->here, (void *)s->here + size, | |
605 | (void *)last - (void *)s->here + sizeof(__u32)); | |
606 | memset(last, 0, size); | |
607 | } | |
608 | } | |
609 | ||
610 | if (i->value) { | |
611 | /* Insert the new value. */ | |
612 | s->here->e_value_size = cpu_to_le32(i->value_len); | |
613 | if (i->value_len) { | |
614 | size_t size = EXT3_XATTR_SIZE(i->value_len); | |
615 | void *val = s->base + min_offs - size; | |
616 | s->here->e_value_offs = cpu_to_le16(min_offs - size); | |
617 | memset(val + size - EXT3_XATTR_PAD, 0, | |
618 | EXT3_XATTR_PAD); /* Clear the pad bytes. */ | |
619 | memcpy(val, i->value, i->value_len); | |
620 | } | |
621 | } | |
622 | return 0; | |
623 | } | |
624 | ||
625 | struct ext3_xattr_block_find { | |
626 | struct ext3_xattr_search s; | |
627 | struct buffer_head *bh; | |
628 | }; | |
629 | ||
381be254 | 630 | static int |
1da177e4 LT |
631 | ext3_xattr_block_find(struct inode *inode, struct ext3_xattr_info *i, |
632 | struct ext3_xattr_block_find *bs) | |
633 | { | |
634 | struct super_block *sb = inode->i_sb; | |
635 | int error; | |
636 | ||
637 | ea_idebug(inode, "name=%d.%s, value=%p, value_len=%ld", | |
638 | i->name_index, i->name, i->value, (long)i->value_len); | |
639 | ||
640 | if (EXT3_I(inode)->i_file_acl) { | |
641 | /* The inode already has an extended attribute block. */ | |
642 | bs->bh = sb_bread(sb, EXT3_I(inode)->i_file_acl); | |
643 | error = -EIO; | |
644 | if (!bs->bh) | |
645 | goto cleanup; | |
646 | ea_bdebug(bs->bh, "b_count=%d, refcount=%d", | |
647 | atomic_read(&(bs->bh->b_count)), | |
648 | le32_to_cpu(BHDR(bs->bh)->h_refcount)); | |
649 | if (ext3_xattr_check_block(bs->bh)) { | |
e05b6b52 | 650 | ext3_error(sb, __func__, |
eee194e7 | 651 | "inode %lu: bad block "E3FSBLK, inode->i_ino, |
1da177e4 LT |
652 | EXT3_I(inode)->i_file_acl); |
653 | error = -EIO; | |
654 | goto cleanup; | |
655 | } | |
656 | /* Find the named attribute. */ | |
657 | bs->s.base = BHDR(bs->bh); | |
658 | bs->s.first = BFIRST(bs->bh); | |
659 | bs->s.end = bs->bh->b_data + bs->bh->b_size; | |
660 | bs->s.here = bs->s.first; | |
661 | error = ext3_xattr_find_entry(&bs->s.here, i->name_index, | |
662 | i->name, bs->bh->b_size, 1); | |
663 | if (error && error != -ENODATA) | |
664 | goto cleanup; | |
665 | bs->s.not_found = error; | |
666 | } | |
667 | error = 0; | |
668 | ||
669 | cleanup: | |
670 | return error; | |
671 | } | |
672 | ||
673 | static int | |
674 | ext3_xattr_block_set(handle_t *handle, struct inode *inode, | |
675 | struct ext3_xattr_info *i, | |
676 | struct ext3_xattr_block_find *bs) | |
677 | { | |
678 | struct super_block *sb = inode->i_sb; | |
679 | struct buffer_head *new_bh = NULL; | |
680 | struct ext3_xattr_search *s = &bs->s; | |
681 | struct mb_cache_entry *ce = NULL; | |
8a2bfdcb | 682 | int error = 0; |
1da177e4 LT |
683 | |
684 | #define header(x) ((struct ext3_xattr_header *)(x)) | |
685 | ||
686 | if (i->value && i->value_len > sb->s_blocksize) | |
687 | return -ENOSPC; | |
688 | if (s->base) { | |
689 | ce = mb_cache_entry_get(ext3_xattr_cache, bs->bh->b_bdev, | |
690 | bs->bh->b_blocknr); | |
8a2bfdcb MC |
691 | error = ext3_journal_get_write_access(handle, bs->bh); |
692 | if (error) | |
693 | goto cleanup; | |
694 | lock_buffer(bs->bh); | |
695 | ||
1da177e4 LT |
696 | if (header(s->base)->h_refcount == cpu_to_le32(1)) { |
697 | if (ce) { | |
698 | mb_cache_entry_free(ce); | |
699 | ce = NULL; | |
700 | } | |
701 | ea_bdebug(bs->bh, "modifying in-place"); | |
1da177e4 LT |
702 | error = ext3_xattr_set_entry(i, s); |
703 | if (!error) { | |
704 | if (!IS_LAST_ENTRY(s->first)) | |
705 | ext3_xattr_rehash(header(s->base), | |
706 | s->here); | |
707 | ext3_xattr_cache_insert(bs->bh); | |
708 | } | |
709 | unlock_buffer(bs->bh); | |
710 | if (error == -EIO) | |
711 | goto bad_block; | |
712 | if (!error) | |
713 | error = ext3_journal_dirty_metadata(handle, | |
714 | bs->bh); | |
715 | if (error) | |
716 | goto cleanup; | |
717 | goto inserted; | |
718 | } else { | |
719 | int offset = (char *)s->here - bs->bh->b_data; | |
720 | ||
8a2bfdcb MC |
721 | unlock_buffer(bs->bh); |
722 | journal_release_buffer(handle, bs->bh); | |
723 | ||
1da177e4 LT |
724 | if (ce) { |
725 | mb_cache_entry_release(ce); | |
726 | ce = NULL; | |
727 | } | |
728 | ea_bdebug(bs->bh, "cloning"); | |
c587f0c0 | 729 | s->base = kmalloc(bs->bh->b_size, GFP_NOFS); |
1da177e4 LT |
730 | error = -ENOMEM; |
731 | if (s->base == NULL) | |
732 | goto cleanup; | |
733 | memcpy(s->base, BHDR(bs->bh), bs->bh->b_size); | |
734 | s->first = ENTRY(header(s->base)+1); | |
735 | header(s->base)->h_refcount = cpu_to_le32(1); | |
736 | s->here = ENTRY(s->base + offset); | |
737 | s->end = s->base + bs->bh->b_size; | |
738 | } | |
739 | } else { | |
740 | /* Allocate a buffer where we construct the new block. */ | |
c587f0c0 | 741 | s->base = kzalloc(sb->s_blocksize, GFP_NOFS); |
1da177e4 LT |
742 | /* assert(header == s->base) */ |
743 | error = -ENOMEM; | |
744 | if (s->base == NULL) | |
745 | goto cleanup; | |
1da177e4 LT |
746 | header(s->base)->h_magic = cpu_to_le32(EXT3_XATTR_MAGIC); |
747 | header(s->base)->h_blocks = cpu_to_le32(1); | |
748 | header(s->base)->h_refcount = cpu_to_le32(1); | |
749 | s->first = ENTRY(header(s->base)+1); | |
750 | s->here = ENTRY(header(s->base)+1); | |
751 | s->end = s->base + sb->s_blocksize; | |
752 | } | |
753 | ||
754 | error = ext3_xattr_set_entry(i, s); | |
755 | if (error == -EIO) | |
756 | goto bad_block; | |
757 | if (error) | |
758 | goto cleanup; | |
759 | if (!IS_LAST_ENTRY(s->first)) | |
760 | ext3_xattr_rehash(header(s->base), s->here); | |
761 | ||
762 | inserted: | |
763 | if (!IS_LAST_ENTRY(s->first)) { | |
764 | new_bh = ext3_xattr_cache_find(inode, header(s->base), &ce); | |
765 | if (new_bh) { | |
766 | /* We found an identical block in the cache. */ | |
767 | if (new_bh == bs->bh) | |
768 | ea_bdebug(new_bh, "keeping"); | |
769 | else { | |
770 | /* The old block is released after updating | |
771 | the inode. */ | |
5dd4056d CH |
772 | error = dquot_alloc_block(inode, 1); |
773 | if (error) | |
1da177e4 LT |
774 | goto cleanup; |
775 | error = ext3_journal_get_write_access(handle, | |
776 | new_bh); | |
777 | if (error) | |
778 | goto cleanup_dquot; | |
779 | lock_buffer(new_bh); | |
50e8a289 | 780 | le32_add_cpu(&BHDR(new_bh)->h_refcount, 1); |
1da177e4 LT |
781 | ea_bdebug(new_bh, "reusing; refcount now=%d", |
782 | le32_to_cpu(BHDR(new_bh)->h_refcount)); | |
783 | unlock_buffer(new_bh); | |
784 | error = ext3_journal_dirty_metadata(handle, | |
785 | new_bh); | |
786 | if (error) | |
787 | goto cleanup_dquot; | |
788 | } | |
789 | mb_cache_entry_release(ce); | |
790 | ce = NULL; | |
791 | } else if (bs->bh && s->base == bs->bh->b_data) { | |
792 | /* We were modifying this block in-place. */ | |
793 | ea_bdebug(bs->bh, "keeping this block"); | |
794 | new_bh = bs->bh; | |
795 | get_bh(new_bh); | |
796 | } else { | |
797 | /* We need to allocate a new block */ | |
1eaafeae AM |
798 | ext3_fsblk_t goal = ext3_group_first_block_no(sb, |
799 | EXT3_I(inode)->i_block_group); | |
ad95c5e9 JK |
800 | ext3_fsblk_t block; |
801 | ||
802 | /* | |
803 | * Protect us agaist concurrent allocations to the | |
804 | * same inode from ext3_..._writepage(). Reservation | |
805 | * code does not expect racing allocations. | |
806 | */ | |
807 | mutex_lock(&EXT3_I(inode)->truncate_mutex); | |
808 | block = ext3_new_block(handle, inode, goal, &error); | |
809 | mutex_unlock(&EXT3_I(inode)->truncate_mutex); | |
1da177e4 LT |
810 | if (error) |
811 | goto cleanup; | |
812 | ea_idebug(inode, "creating block %d", block); | |
813 | ||
814 | new_bh = sb_getblk(sb, block); | |
1b7d76e9 | 815 | if (unlikely(!new_bh)) { |
1da177e4 LT |
816 | getblk_failed: |
817 | ext3_free_blocks(handle, inode, block, 1); | |
c04e88e2 | 818 | error = -ENOMEM; |
1da177e4 LT |
819 | goto cleanup; |
820 | } | |
821 | lock_buffer(new_bh); | |
822 | error = ext3_journal_get_create_access(handle, new_bh); | |
823 | if (error) { | |
824 | unlock_buffer(new_bh); | |
825 | goto getblk_failed; | |
826 | } | |
827 | memcpy(new_bh->b_data, s->base, new_bh->b_size); | |
828 | set_buffer_uptodate(new_bh); | |
829 | unlock_buffer(new_bh); | |
830 | ext3_xattr_cache_insert(new_bh); | |
831 | error = ext3_journal_dirty_metadata(handle, new_bh); | |
832 | if (error) | |
833 | goto cleanup; | |
834 | } | |
835 | } | |
836 | ||
837 | /* Update the inode. */ | |
838 | EXT3_I(inode)->i_file_acl = new_bh ? new_bh->b_blocknr : 0; | |
839 | ||
840 | /* Drop the previous xattr block. */ | |
841 | if (bs->bh && bs->bh != new_bh) | |
842 | ext3_xattr_release_block(handle, inode, bs->bh); | |
843 | error = 0; | |
844 | ||
845 | cleanup: | |
846 | if (ce) | |
847 | mb_cache_entry_release(ce); | |
848 | brelse(new_bh); | |
849 | if (!(bs->bh && s->base == bs->bh->b_data)) | |
850 | kfree(s->base); | |
851 | ||
852 | return error; | |
853 | ||
854 | cleanup_dquot: | |
5dd4056d | 855 | dquot_free_block(inode, 1); |
1da177e4 LT |
856 | goto cleanup; |
857 | ||
858 | bad_block: | |
e05b6b52 | 859 | ext3_error(inode->i_sb, __func__, |
eee194e7 | 860 | "inode %lu: bad block "E3FSBLK, inode->i_ino, |
1da177e4 LT |
861 | EXT3_I(inode)->i_file_acl); |
862 | goto cleanup; | |
863 | ||
864 | #undef header | |
865 | } | |
866 | ||
867 | struct ext3_xattr_ibody_find { | |
868 | struct ext3_xattr_search s; | |
869 | struct ext3_iloc iloc; | |
870 | }; | |
871 | ||
381be254 | 872 | static int |
1da177e4 LT |
873 | ext3_xattr_ibody_find(struct inode *inode, struct ext3_xattr_info *i, |
874 | struct ext3_xattr_ibody_find *is) | |
875 | { | |
876 | struct ext3_xattr_ibody_header *header; | |
877 | struct ext3_inode *raw_inode; | |
878 | int error; | |
879 | ||
880 | if (EXT3_I(inode)->i_extra_isize == 0) | |
881 | return 0; | |
882 | raw_inode = ext3_raw_inode(&is->iloc); | |
883 | header = IHDR(inode, raw_inode); | |
884 | is->s.base = is->s.first = IFIRST(header); | |
885 | is->s.here = is->s.first; | |
886 | is->s.end = (void *)raw_inode + EXT3_SB(inode->i_sb)->s_inode_size; | |
9df93939 | 887 | if (ext3_test_inode_state(inode, EXT3_STATE_XATTR)) { |
1da177e4 LT |
888 | error = ext3_xattr_check_names(IFIRST(header), is->s.end); |
889 | if (error) | |
890 | return error; | |
891 | /* Find the named attribute. */ | |
892 | error = ext3_xattr_find_entry(&is->s.here, i->name_index, | |
893 | i->name, is->s.end - | |
894 | (void *)is->s.base, 0); | |
895 | if (error && error != -ENODATA) | |
896 | return error; | |
897 | is->s.not_found = error; | |
898 | } | |
899 | return 0; | |
900 | } | |
901 | ||
902 | static int | |
903 | ext3_xattr_ibody_set(handle_t *handle, struct inode *inode, | |
904 | struct ext3_xattr_info *i, | |
905 | struct ext3_xattr_ibody_find *is) | |
906 | { | |
907 | struct ext3_xattr_ibody_header *header; | |
908 | struct ext3_xattr_search *s = &is->s; | |
909 | int error; | |
910 | ||
911 | if (EXT3_I(inode)->i_extra_isize == 0) | |
912 | return -ENOSPC; | |
913 | error = ext3_xattr_set_entry(i, s); | |
914 | if (error) | |
915 | return error; | |
916 | header = IHDR(inode, ext3_raw_inode(&is->iloc)); | |
917 | if (!IS_LAST_ENTRY(s->first)) { | |
918 | header->h_magic = cpu_to_le32(EXT3_XATTR_MAGIC); | |
9df93939 | 919 | ext3_set_inode_state(inode, EXT3_STATE_XATTR); |
1da177e4 LT |
920 | } else { |
921 | header->h_magic = cpu_to_le32(0); | |
9df93939 | 922 | ext3_clear_inode_state(inode, EXT3_STATE_XATTR); |
1da177e4 LT |
923 | } |
924 | return 0; | |
925 | } | |
926 | ||
927 | /* | |
928 | * ext3_xattr_set_handle() | |
929 | * | |
6e9510b0 | 930 | * Create, replace or remove an extended attribute for this inode. Value |
1da177e4 LT |
931 | * is NULL to remove an existing extended attribute, and non-NULL to |
932 | * either replace an existing extended attribute, or create a new extended | |
933 | * attribute. The flags XATTR_REPLACE and XATTR_CREATE | |
934 | * specify that an extended attribute must exist and must not exist | |
935 | * previous to the call, respectively. | |
936 | * | |
937 | * Returns 0, or a negative error number on failure. | |
938 | */ | |
939 | int | |
940 | ext3_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index, | |
941 | const char *name, const void *value, size_t value_len, | |
942 | int flags) | |
943 | { | |
944 | struct ext3_xattr_info i = { | |
945 | .name_index = name_index, | |
946 | .name = name, | |
947 | .value = value, | |
948 | .value_len = value_len, | |
949 | ||
950 | }; | |
951 | struct ext3_xattr_ibody_find is = { | |
952 | .s = { .not_found = -ENODATA, }, | |
953 | }; | |
954 | struct ext3_xattr_block_find bs = { | |
955 | .s = { .not_found = -ENODATA, }, | |
956 | }; | |
957 | int error; | |
958 | ||
1da177e4 LT |
959 | if (!name) |
960 | return -EINVAL; | |
961 | if (strlen(name) > 255) | |
962 | return -ERANGE; | |
963 | down_write(&EXT3_I(inode)->xattr_sem); | |
964 | error = ext3_get_inode_loc(inode, &is.iloc); | |
965 | if (error) | |
966 | goto cleanup; | |
967 | ||
d965736b ES |
968 | error = ext3_journal_get_write_access(handle, is.iloc.bh); |
969 | if (error) | |
970 | goto cleanup; | |
971 | ||
9df93939 | 972 | if (ext3_test_inode_state(inode, EXT3_STATE_NEW)) { |
1da177e4 LT |
973 | struct ext3_inode *raw_inode = ext3_raw_inode(&is.iloc); |
974 | memset(raw_inode, 0, EXT3_SB(inode->i_sb)->s_inode_size); | |
9df93939 | 975 | ext3_clear_inode_state(inode, EXT3_STATE_NEW); |
1da177e4 LT |
976 | } |
977 | ||
978 | error = ext3_xattr_ibody_find(inode, &i, &is); | |
979 | if (error) | |
980 | goto cleanup; | |
981 | if (is.s.not_found) | |
982 | error = ext3_xattr_block_find(inode, &i, &bs); | |
983 | if (error) | |
984 | goto cleanup; | |
985 | if (is.s.not_found && bs.s.not_found) { | |
986 | error = -ENODATA; | |
987 | if (flags & XATTR_REPLACE) | |
988 | goto cleanup; | |
989 | error = 0; | |
990 | if (!value) | |
991 | goto cleanup; | |
992 | } else { | |
993 | error = -EEXIST; | |
994 | if (flags & XATTR_CREATE) | |
995 | goto cleanup; | |
996 | } | |
1da177e4 LT |
997 | if (!value) { |
998 | if (!is.s.not_found) | |
999 | error = ext3_xattr_ibody_set(handle, inode, &i, &is); | |
1000 | else if (!bs.s.not_found) | |
1001 | error = ext3_xattr_block_set(handle, inode, &i, &bs); | |
1002 | } else { | |
1003 | error = ext3_xattr_ibody_set(handle, inode, &i, &is); | |
1004 | if (!error && !bs.s.not_found) { | |
1005 | i.value = NULL; | |
1006 | error = ext3_xattr_block_set(handle, inode, &i, &bs); | |
1007 | } else if (error == -ENOSPC) { | |
7e01c8e5 TY |
1008 | if (EXT3_I(inode)->i_file_acl && !bs.s.base) { |
1009 | error = ext3_xattr_block_find(inode, &i, &bs); | |
1010 | if (error) | |
1011 | goto cleanup; | |
1012 | } | |
1da177e4 LT |
1013 | error = ext3_xattr_block_set(handle, inode, &i, &bs); |
1014 | if (error) | |
1015 | goto cleanup; | |
1016 | if (!is.s.not_found) { | |
1017 | i.value = NULL; | |
1018 | error = ext3_xattr_ibody_set(handle, inode, &i, | |
1019 | &is); | |
1020 | } | |
1021 | } | |
1022 | } | |
1023 | if (!error) { | |
1024 | ext3_xattr_update_super_block(handle, inode->i_sb); | |
1025 | inode->i_ctime = CURRENT_TIME_SEC; | |
1026 | error = ext3_mark_iloc_dirty(handle, inode, &is.iloc); | |
1027 | /* | |
1028 | * The bh is consumed by ext3_mark_iloc_dirty, even with | |
1029 | * error != 0. | |
1030 | */ | |
1031 | is.iloc.bh = NULL; | |
1032 | if (IS_SYNC(inode)) | |
1033 | handle->h_sync = 1; | |
1034 | } | |
1035 | ||
1036 | cleanup: | |
1037 | brelse(is.iloc.bh); | |
1038 | brelse(bs.bh); | |
1039 | up_write(&EXT3_I(inode)->xattr_sem); | |
1040 | return error; | |
1041 | } | |
1042 | ||
1043 | /* | |
1044 | * ext3_xattr_set() | |
1045 | * | |
1046 | * Like ext3_xattr_set_handle, but start from an inode. This extended | |
1047 | * attribute modification is a filesystem transaction by itself. | |
1048 | * | |
1049 | * Returns 0, or a negative error number on failure. | |
1050 | */ | |
1051 | int | |
1052 | ext3_xattr_set(struct inode *inode, int name_index, const char *name, | |
1053 | const void *value, size_t value_len, int flags) | |
1054 | { | |
1055 | handle_t *handle; | |
1056 | int error, retries = 0; | |
1057 | ||
1058 | retry: | |
1f54587b | 1059 | handle = ext3_journal_start(inode, EXT3_DATA_TRANS_BLOCKS(inode->i_sb)); |
1da177e4 LT |
1060 | if (IS_ERR(handle)) { |
1061 | error = PTR_ERR(handle); | |
1062 | } else { | |
1063 | int error2; | |
1064 | ||
1065 | error = ext3_xattr_set_handle(handle, inode, name_index, name, | |
1066 | value, value_len, flags); | |
1067 | error2 = ext3_journal_stop(handle); | |
1068 | if (error == -ENOSPC && | |
1069 | ext3_should_retry_alloc(inode->i_sb, &retries)) | |
1070 | goto retry; | |
1071 | if (error == 0) | |
1072 | error = error2; | |
1073 | } | |
1074 | ||
1075 | return error; | |
1076 | } | |
1077 | ||
1078 | /* | |
1079 | * ext3_xattr_delete_inode() | |
1080 | * | |
1081 | * Free extended attribute resources associated with this inode. This | |
1082 | * is called immediately before an inode is freed. We have exclusive | |
1083 | * access to the inode. | |
1084 | */ | |
1085 | void | |
1086 | ext3_xattr_delete_inode(handle_t *handle, struct inode *inode) | |
1087 | { | |
1088 | struct buffer_head *bh = NULL; | |
1089 | ||
1090 | if (!EXT3_I(inode)->i_file_acl) | |
1091 | goto cleanup; | |
1092 | bh = sb_bread(inode->i_sb, EXT3_I(inode)->i_file_acl); | |
1093 | if (!bh) { | |
e05b6b52 | 1094 | ext3_error(inode->i_sb, __func__, |
eee194e7 | 1095 | "inode %lu: block "E3FSBLK" read error", inode->i_ino, |
1da177e4 LT |
1096 | EXT3_I(inode)->i_file_acl); |
1097 | goto cleanup; | |
1098 | } | |
1099 | if (BHDR(bh)->h_magic != cpu_to_le32(EXT3_XATTR_MAGIC) || | |
1100 | BHDR(bh)->h_blocks != cpu_to_le32(1)) { | |
e05b6b52 | 1101 | ext3_error(inode->i_sb, __func__, |
eee194e7 | 1102 | "inode %lu: bad block "E3FSBLK, inode->i_ino, |
1da177e4 LT |
1103 | EXT3_I(inode)->i_file_acl); |
1104 | goto cleanup; | |
1105 | } | |
1106 | ext3_xattr_release_block(handle, inode, bh); | |
1107 | EXT3_I(inode)->i_file_acl = 0; | |
1108 | ||
1109 | cleanup: | |
1110 | brelse(bh); | |
1111 | } | |
1112 | ||
1113 | /* | |
1114 | * ext3_xattr_put_super() | |
1115 | * | |
1116 | * This is called when a file system is unmounted. | |
1117 | */ | |
1118 | void | |
1119 | ext3_xattr_put_super(struct super_block *sb) | |
1120 | { | |
8c52ab42 | 1121 | mb_cache_shrink(sb->s_bdev); |
1da177e4 LT |
1122 | } |
1123 | ||
1124 | /* | |
1125 | * ext3_xattr_cache_insert() | |
1126 | * | |
1127 | * Create a new entry in the extended attribute cache, and insert | |
1128 | * it unless such an entry is already in the cache. | |
1129 | * | |
1130 | * Returns 0, or a negative error number on failure. | |
1131 | */ | |
1132 | static void | |
1133 | ext3_xattr_cache_insert(struct buffer_head *bh) | |
1134 | { | |
1135 | __u32 hash = le32_to_cpu(BHDR(bh)->h_hash); | |
1136 | struct mb_cache_entry *ce; | |
1137 | int error; | |
1138 | ||
335e92e8 | 1139 | ce = mb_cache_entry_alloc(ext3_xattr_cache, GFP_NOFS); |
1da177e4 LT |
1140 | if (!ce) { |
1141 | ea_bdebug(bh, "out of memory"); | |
1142 | return; | |
1143 | } | |
2aec7c52 | 1144 | error = mb_cache_entry_insert(ce, bh->b_bdev, bh->b_blocknr, hash); |
1da177e4 LT |
1145 | if (error) { |
1146 | mb_cache_entry_free(ce); | |
1147 | if (error == -EBUSY) { | |
1148 | ea_bdebug(bh, "already in cache"); | |
1149 | error = 0; | |
1150 | } | |
1151 | } else { | |
1152 | ea_bdebug(bh, "inserting [%x]", (int)hash); | |
1153 | mb_cache_entry_release(ce); | |
1154 | } | |
1155 | } | |
1156 | ||
1157 | /* | |
1158 | * ext3_xattr_cmp() | |
1159 | * | |
1160 | * Compare two extended attribute blocks for equality. | |
1161 | * | |
1162 | * Returns 0 if the blocks are equal, 1 if they differ, and | |
1163 | * a negative error number on errors. | |
1164 | */ | |
1165 | static int | |
1166 | ext3_xattr_cmp(struct ext3_xattr_header *header1, | |
1167 | struct ext3_xattr_header *header2) | |
1168 | { | |
1169 | struct ext3_xattr_entry *entry1, *entry2; | |
1170 | ||
1171 | entry1 = ENTRY(header1+1); | |
1172 | entry2 = ENTRY(header2+1); | |
1173 | while (!IS_LAST_ENTRY(entry1)) { | |
1174 | if (IS_LAST_ENTRY(entry2)) | |
1175 | return 1; | |
1176 | if (entry1->e_hash != entry2->e_hash || | |
1177 | entry1->e_name_index != entry2->e_name_index || | |
1178 | entry1->e_name_len != entry2->e_name_len || | |
1179 | entry1->e_value_size != entry2->e_value_size || | |
1180 | memcmp(entry1->e_name, entry2->e_name, entry1->e_name_len)) | |
1181 | return 1; | |
1182 | if (entry1->e_value_block != 0 || entry2->e_value_block != 0) | |
1183 | return -EIO; | |
1184 | if (memcmp((char *)header1 + le16_to_cpu(entry1->e_value_offs), | |
1185 | (char *)header2 + le16_to_cpu(entry2->e_value_offs), | |
1186 | le32_to_cpu(entry1->e_value_size))) | |
1187 | return 1; | |
1188 | ||
1189 | entry1 = EXT3_XATTR_NEXT(entry1); | |
1190 | entry2 = EXT3_XATTR_NEXT(entry2); | |
1191 | } | |
1192 | if (!IS_LAST_ENTRY(entry2)) | |
1193 | return 1; | |
1194 | return 0; | |
1195 | } | |
1196 | ||
1197 | /* | |
1198 | * ext3_xattr_cache_find() | |
1199 | * | |
1200 | * Find an identical extended attribute block. | |
1201 | * | |
1202 | * Returns a pointer to the block found, or NULL if such a block was | |
1203 | * not found or an error occurred. | |
1204 | */ | |
1205 | static struct buffer_head * | |
1206 | ext3_xattr_cache_find(struct inode *inode, struct ext3_xattr_header *header, | |
1207 | struct mb_cache_entry **pce) | |
1208 | { | |
1209 | __u32 hash = le32_to_cpu(header->h_hash); | |
1210 | struct mb_cache_entry *ce; | |
1211 | ||
1212 | if (!header->h_hash) | |
1213 | return NULL; /* never share */ | |
1214 | ea_idebug(inode, "looking for cached blocks [%x]", (int)hash); | |
1215 | again: | |
2aec7c52 AG |
1216 | ce = mb_cache_entry_find_first(ext3_xattr_cache, inode->i_sb->s_bdev, |
1217 | hash); | |
1da177e4 LT |
1218 | while (ce) { |
1219 | struct buffer_head *bh; | |
1220 | ||
1221 | if (IS_ERR(ce)) { | |
1222 | if (PTR_ERR(ce) == -EAGAIN) | |
1223 | goto again; | |
1224 | break; | |
1225 | } | |
1226 | bh = sb_bread(inode->i_sb, ce->e_block); | |
1227 | if (!bh) { | |
e05b6b52 | 1228 | ext3_error(inode->i_sb, __func__, |
eee194e7 | 1229 | "inode %lu: block %lu read error", |
1da177e4 LT |
1230 | inode->i_ino, (unsigned long) ce->e_block); |
1231 | } else if (le32_to_cpu(BHDR(bh)->h_refcount) >= | |
1232 | EXT3_XATTR_REFCOUNT_MAX) { | |
1c2bf374 | 1233 | ea_idebug(inode, "block %lu refcount %d>=%d", |
1da177e4 LT |
1234 | (unsigned long) ce->e_block, |
1235 | le32_to_cpu(BHDR(bh)->h_refcount), | |
1236 | EXT3_XATTR_REFCOUNT_MAX); | |
1237 | } else if (ext3_xattr_cmp(header, BHDR(bh)) == 0) { | |
1238 | *pce = ce; | |
1239 | return bh; | |
1240 | } | |
1241 | brelse(bh); | |
2aec7c52 | 1242 | ce = mb_cache_entry_find_next(ce, inode->i_sb->s_bdev, hash); |
1da177e4 LT |
1243 | } |
1244 | return NULL; | |
1245 | } | |
1246 | ||
1247 | #define NAME_HASH_SHIFT 5 | |
1248 | #define VALUE_HASH_SHIFT 16 | |
1249 | ||
1250 | /* | |
1251 | * ext3_xattr_hash_entry() | |
1252 | * | |
1253 | * Compute the hash of an extended attribute. | |
1254 | */ | |
1255 | static inline void ext3_xattr_hash_entry(struct ext3_xattr_header *header, | |
1256 | struct ext3_xattr_entry *entry) | |
1257 | { | |
1258 | __u32 hash = 0; | |
1259 | char *name = entry->e_name; | |
1260 | int n; | |
1261 | ||
1262 | for (n=0; n < entry->e_name_len; n++) { | |
1263 | hash = (hash << NAME_HASH_SHIFT) ^ | |
1264 | (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^ | |
1265 | *name++; | |
1266 | } | |
1267 | ||
1268 | if (entry->e_value_block == 0 && entry->e_value_size != 0) { | |
1269 | __le32 *value = (__le32 *)((char *)header + | |
1270 | le16_to_cpu(entry->e_value_offs)); | |
1271 | for (n = (le32_to_cpu(entry->e_value_size) + | |
1272 | EXT3_XATTR_ROUND) >> EXT3_XATTR_PAD_BITS; n; n--) { | |
1273 | hash = (hash << VALUE_HASH_SHIFT) ^ | |
1274 | (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^ | |
1275 | le32_to_cpu(*value++); | |
1276 | } | |
1277 | } | |
1278 | entry->e_hash = cpu_to_le32(hash); | |
1279 | } | |
1280 | ||
1281 | #undef NAME_HASH_SHIFT | |
1282 | #undef VALUE_HASH_SHIFT | |
1283 | ||
1284 | #define BLOCK_HASH_SHIFT 16 | |
1285 | ||
1286 | /* | |
1287 | * ext3_xattr_rehash() | |
1288 | * | |
1289 | * Re-compute the extended attribute hash value after an entry has changed. | |
1290 | */ | |
1291 | static void ext3_xattr_rehash(struct ext3_xattr_header *header, | |
1292 | struct ext3_xattr_entry *entry) | |
1293 | { | |
1294 | struct ext3_xattr_entry *here; | |
1295 | __u32 hash = 0; | |
1296 | ||
1297 | ext3_xattr_hash_entry(header, entry); | |
1298 | here = ENTRY(header+1); | |
1299 | while (!IS_LAST_ENTRY(here)) { | |
1300 | if (!here->e_hash) { | |
1301 | /* Block is not shared if an entry's hash value == 0 */ | |
1302 | hash = 0; | |
1303 | break; | |
1304 | } | |
1305 | hash = (hash << BLOCK_HASH_SHIFT) ^ | |
1306 | (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^ | |
1307 | le32_to_cpu(here->e_hash); | |
1308 | here = EXT3_XATTR_NEXT(here); | |
1309 | } | |
1310 | header->h_hash = cpu_to_le32(hash); | |
1311 | } | |
1312 | ||
1313 | #undef BLOCK_HASH_SHIFT | |
1314 | ||
1315 | int __init | |
1316 | init_ext3_xattr(void) | |
1317 | { | |
2aec7c52 | 1318 | ext3_xattr_cache = mb_cache_create("ext3_xattr", 6); |
1da177e4 LT |
1319 | if (!ext3_xattr_cache) |
1320 | return -ENOMEM; | |
1321 | return 0; | |
1322 | } | |
1323 | ||
1324 | void | |
1325 | exit_ext3_xattr(void) | |
1326 | { | |
1327 | if (ext3_xattr_cache) | |
1328 | mb_cache_destroy(ext3_xattr_cache); | |
1329 | ext3_xattr_cache = NULL; | |
1330 | } |