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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 | ||
53 | #include <linux/init.h> | |
54 | #include <linux/fs.h> | |
55 | #include <linux/slab.h> | |
56 | #include <linux/ext3_jbd.h> | |
57 | #include <linux/ext3_fs.h> | |
58 | #include <linux/mbcache.h> | |
59 | #include <linux/quotaops.h> | |
60 | #include <linux/rwsem.h> | |
61 | #include "xattr.h" | |
62 | #include "acl.h" | |
63 | ||
64 | #define BHDR(bh) ((struct ext3_xattr_header *)((bh)->b_data)) | |
65 | #define ENTRY(ptr) ((struct ext3_xattr_entry *)(ptr)) | |
66 | #define BFIRST(bh) ENTRY(BHDR(bh)+1) | |
67 | #define IS_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0) | |
68 | ||
69 | #define IHDR(inode, raw_inode) \ | |
70 | ((struct ext3_xattr_ibody_header *) \ | |
71 | ((void *)raw_inode + \ | |
72 | EXT3_GOOD_OLD_INODE_SIZE + \ | |
73 | EXT3_I(inode)->i_extra_isize)) | |
74 | #define IFIRST(hdr) ((struct ext3_xattr_entry *)((hdr)+1)) | |
75 | ||
76 | #ifdef EXT3_XATTR_DEBUG | |
77 | # define ea_idebug(inode, f...) do { \ | |
eee194e7 | 78 | printk(KERN_DEBUG "inode %s:%lu: ", \ |
1da177e4 LT |
79 | inode->i_sb->s_id, inode->i_ino); \ |
80 | printk(f); \ | |
81 | printk("\n"); \ | |
82 | } while (0) | |
83 | # define ea_bdebug(bh, f...) do { \ | |
84 | char b[BDEVNAME_SIZE]; \ | |
85 | printk(KERN_DEBUG "block %s:%lu: ", \ | |
86 | bdevname(bh->b_bdev, b), \ | |
87 | (unsigned long) bh->b_blocknr); \ | |
88 | printk(f); \ | |
89 | printk("\n"); \ | |
90 | } while (0) | |
91 | #else | |
92 | # define ea_idebug(f...) | |
93 | # define ea_bdebug(f...) | |
94 | #endif | |
95 | ||
96 | static void ext3_xattr_cache_insert(struct buffer_head *); | |
97 | static struct buffer_head *ext3_xattr_cache_find(struct inode *, | |
98 | struct ext3_xattr_header *, | |
99 | struct mb_cache_entry **); | |
100 | static void ext3_xattr_rehash(struct ext3_xattr_header *, | |
101 | struct ext3_xattr_entry *); | |
15633005 AB |
102 | static int ext3_xattr_list(struct inode *inode, char *buffer, |
103 | size_t buffer_size); | |
1da177e4 LT |
104 | |
105 | static struct mb_cache *ext3_xattr_cache; | |
106 | ||
107 | static struct xattr_handler *ext3_xattr_handler_map[] = { | |
108 | [EXT3_XATTR_INDEX_USER] = &ext3_xattr_user_handler, | |
109 | #ifdef CONFIG_EXT3_FS_POSIX_ACL | |
110 | [EXT3_XATTR_INDEX_POSIX_ACL_ACCESS] = &ext3_xattr_acl_access_handler, | |
111 | [EXT3_XATTR_INDEX_POSIX_ACL_DEFAULT] = &ext3_xattr_acl_default_handler, | |
112 | #endif | |
113 | [EXT3_XATTR_INDEX_TRUSTED] = &ext3_xattr_trusted_handler, | |
114 | #ifdef CONFIG_EXT3_FS_SECURITY | |
115 | [EXT3_XATTR_INDEX_SECURITY] = &ext3_xattr_security_handler, | |
116 | #endif | |
117 | }; | |
118 | ||
119 | struct xattr_handler *ext3_xattr_handlers[] = { | |
120 | &ext3_xattr_user_handler, | |
121 | &ext3_xattr_trusted_handler, | |
122 | #ifdef CONFIG_EXT3_FS_POSIX_ACL | |
123 | &ext3_xattr_acl_access_handler, | |
124 | &ext3_xattr_acl_default_handler, | |
125 | #endif | |
126 | #ifdef CONFIG_EXT3_FS_SECURITY | |
127 | &ext3_xattr_security_handler, | |
128 | #endif | |
129 | NULL | |
130 | }; | |
131 | ||
132 | static inline struct xattr_handler * | |
133 | ext3_xattr_handler(int name_index) | |
134 | { | |
135 | struct xattr_handler *handler = NULL; | |
136 | ||
137 | if (name_index > 0 && name_index < ARRAY_SIZE(ext3_xattr_handler_map)) | |
138 | handler = ext3_xattr_handler_map[name_index]; | |
139 | return handler; | |
140 | } | |
141 | ||
142 | /* | |
143 | * Inode operation listxattr() | |
144 | * | |
1b1dcc1b | 145 | * dentry->d_inode->i_mutex: don't care |
1da177e4 LT |
146 | */ |
147 | ssize_t | |
148 | ext3_listxattr(struct dentry *dentry, char *buffer, size_t size) | |
149 | { | |
150 | return ext3_xattr_list(dentry->d_inode, buffer, size); | |
151 | } | |
152 | ||
153 | static int | |
154 | ext3_xattr_check_names(struct ext3_xattr_entry *entry, void *end) | |
155 | { | |
156 | while (!IS_LAST_ENTRY(entry)) { | |
157 | struct ext3_xattr_entry *next = EXT3_XATTR_NEXT(entry); | |
158 | if ((void *)next >= end) | |
159 | return -EIO; | |
160 | entry = next; | |
161 | } | |
162 | return 0; | |
163 | } | |
164 | ||
165 | static inline int | |
166 | ext3_xattr_check_block(struct buffer_head *bh) | |
167 | { | |
168 | int error; | |
169 | ||
170 | if (BHDR(bh)->h_magic != cpu_to_le32(EXT3_XATTR_MAGIC) || | |
171 | BHDR(bh)->h_blocks != cpu_to_le32(1)) | |
172 | return -EIO; | |
173 | error = ext3_xattr_check_names(BFIRST(bh), bh->b_data + bh->b_size); | |
174 | return error; | |
175 | } | |
176 | ||
177 | static inline int | |
178 | ext3_xattr_check_entry(struct ext3_xattr_entry *entry, size_t size) | |
179 | { | |
180 | size_t value_size = le32_to_cpu(entry->e_value_size); | |
181 | ||
182 | if (entry->e_value_block != 0 || value_size > size || | |
183 | le16_to_cpu(entry->e_value_offs) + value_size > size) | |
184 | return -EIO; | |
185 | return 0; | |
186 | } | |
187 | ||
188 | static int | |
189 | ext3_xattr_find_entry(struct ext3_xattr_entry **pentry, int name_index, | |
190 | const char *name, size_t size, int sorted) | |
191 | { | |
192 | struct ext3_xattr_entry *entry; | |
193 | size_t name_len; | |
194 | int cmp = 1; | |
195 | ||
196 | if (name == NULL) | |
197 | return -EINVAL; | |
198 | name_len = strlen(name); | |
199 | entry = *pentry; | |
200 | for (; !IS_LAST_ENTRY(entry); entry = EXT3_XATTR_NEXT(entry)) { | |
201 | cmp = name_index - entry->e_name_index; | |
202 | if (!cmp) | |
203 | cmp = name_len - entry->e_name_len; | |
204 | if (!cmp) | |
205 | cmp = memcmp(name, entry->e_name, name_len); | |
206 | if (cmp <= 0 && (sorted || cmp == 0)) | |
207 | break; | |
208 | } | |
209 | *pentry = entry; | |
210 | if (!cmp && ext3_xattr_check_entry(entry, size)) | |
211 | return -EIO; | |
212 | return cmp ? -ENODATA : 0; | |
213 | } | |
214 | ||
381be254 | 215 | static int |
1da177e4 LT |
216 | ext3_xattr_block_get(struct inode *inode, int name_index, const char *name, |
217 | void *buffer, size_t buffer_size) | |
218 | { | |
219 | struct buffer_head *bh = NULL; | |
220 | struct ext3_xattr_entry *entry; | |
221 | size_t size; | |
222 | int error; | |
223 | ||
224 | ea_idebug(inode, "name=%d.%s, buffer=%p, buffer_size=%ld", | |
225 | name_index, name, buffer, (long)buffer_size); | |
226 | ||
227 | error = -ENODATA; | |
228 | if (!EXT3_I(inode)->i_file_acl) | |
229 | goto cleanup; | |
1c2bf374 | 230 | ea_idebug(inode, "reading block %u", EXT3_I(inode)->i_file_acl); |
1da177e4 LT |
231 | bh = sb_bread(inode->i_sb, EXT3_I(inode)->i_file_acl); |
232 | if (!bh) | |
233 | goto cleanup; | |
234 | ea_bdebug(bh, "b_count=%d, refcount=%d", | |
235 | atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount)); | |
236 | if (ext3_xattr_check_block(bh)) { | |
e05b6b52 | 237 | bad_block: ext3_error(inode->i_sb, __func__, |
eee194e7 | 238 | "inode %lu: bad block "E3FSBLK, inode->i_ino, |
1da177e4 LT |
239 | EXT3_I(inode)->i_file_acl); |
240 | error = -EIO; | |
241 | goto cleanup; | |
242 | } | |
243 | ext3_xattr_cache_insert(bh); | |
244 | entry = BFIRST(bh); | |
245 | error = ext3_xattr_find_entry(&entry, name_index, name, bh->b_size, 1); | |
246 | if (error == -EIO) | |
247 | goto bad_block; | |
248 | if (error) | |
249 | goto cleanup; | |
250 | size = le32_to_cpu(entry->e_value_size); | |
251 | if (buffer) { | |
252 | error = -ERANGE; | |
253 | if (size > buffer_size) | |
254 | goto cleanup; | |
255 | memcpy(buffer, bh->b_data + le16_to_cpu(entry->e_value_offs), | |
256 | size); | |
257 | } | |
258 | error = size; | |
259 | ||
260 | cleanup: | |
261 | brelse(bh); | |
262 | return error; | |
263 | } | |
264 | ||
265 | static int | |
266 | ext3_xattr_ibody_get(struct inode *inode, int name_index, const char *name, | |
267 | void *buffer, size_t buffer_size) | |
268 | { | |
269 | struct ext3_xattr_ibody_header *header; | |
270 | struct ext3_xattr_entry *entry; | |
271 | struct ext3_inode *raw_inode; | |
272 | struct ext3_iloc iloc; | |
273 | size_t size; | |
274 | void *end; | |
275 | int error; | |
276 | ||
277 | if (!(EXT3_I(inode)->i_state & EXT3_STATE_XATTR)) | |
278 | return -ENODATA; | |
279 | error = ext3_get_inode_loc(inode, &iloc); | |
280 | if (error) | |
281 | return error; | |
282 | raw_inode = ext3_raw_inode(&iloc); | |
283 | header = IHDR(inode, raw_inode); | |
284 | entry = IFIRST(header); | |
285 | end = (void *)raw_inode + EXT3_SB(inode->i_sb)->s_inode_size; | |
286 | error = ext3_xattr_check_names(entry, end); | |
287 | if (error) | |
288 | goto cleanup; | |
289 | error = ext3_xattr_find_entry(&entry, name_index, name, | |
290 | end - (void *)entry, 0); | |
291 | if (error) | |
292 | goto cleanup; | |
293 | size = le32_to_cpu(entry->e_value_size); | |
294 | if (buffer) { | |
295 | error = -ERANGE; | |
296 | if (size > buffer_size) | |
297 | goto cleanup; | |
298 | memcpy(buffer, (void *)IFIRST(header) + | |
299 | le16_to_cpu(entry->e_value_offs), size); | |
300 | } | |
301 | error = size; | |
302 | ||
303 | cleanup: | |
304 | brelse(iloc.bh); | |
305 | return error; | |
306 | } | |
307 | ||
308 | /* | |
309 | * ext3_xattr_get() | |
310 | * | |
311 | * Copy an extended attribute into the buffer | |
312 | * provided, or compute the buffer size required. | |
313 | * Buffer is NULL to compute the size of the buffer required. | |
314 | * | |
315 | * Returns a negative error number on failure, or the number of bytes | |
316 | * used / required on success. | |
317 | */ | |
318 | int | |
319 | ext3_xattr_get(struct inode *inode, int name_index, const char *name, | |
320 | void *buffer, size_t buffer_size) | |
321 | { | |
322 | int error; | |
323 | ||
324 | down_read(&EXT3_I(inode)->xattr_sem); | |
325 | error = ext3_xattr_ibody_get(inode, name_index, name, buffer, | |
326 | buffer_size); | |
327 | if (error == -ENODATA) | |
328 | error = ext3_xattr_block_get(inode, name_index, name, buffer, | |
329 | buffer_size); | |
330 | up_read(&EXT3_I(inode)->xattr_sem); | |
331 | return error; | |
332 | } | |
333 | ||
334 | static int | |
335 | ext3_xattr_list_entries(struct inode *inode, struct ext3_xattr_entry *entry, | |
336 | char *buffer, size_t buffer_size) | |
337 | { | |
338 | size_t rest = buffer_size; | |
339 | ||
340 | for (; !IS_LAST_ENTRY(entry); entry = EXT3_XATTR_NEXT(entry)) { | |
341 | struct xattr_handler *handler = | |
342 | ext3_xattr_handler(entry->e_name_index); | |
343 | ||
344 | if (handler) { | |
345 | size_t size = handler->list(inode, buffer, rest, | |
346 | entry->e_name, | |
347 | entry->e_name_len); | |
348 | if (buffer) { | |
349 | if (size > rest) | |
350 | return -ERANGE; | |
351 | buffer += size; | |
352 | } | |
353 | rest -= size; | |
354 | } | |
355 | } | |
356 | return buffer_size - rest; | |
357 | } | |
358 | ||
381be254 | 359 | static int |
1da177e4 LT |
360 | ext3_xattr_block_list(struct inode *inode, char *buffer, size_t buffer_size) |
361 | { | |
362 | struct buffer_head *bh = NULL; | |
363 | int error; | |
364 | ||
365 | ea_idebug(inode, "buffer=%p, buffer_size=%ld", | |
366 | buffer, (long)buffer_size); | |
367 | ||
368 | error = 0; | |
369 | if (!EXT3_I(inode)->i_file_acl) | |
370 | goto cleanup; | |
1c2bf374 | 371 | ea_idebug(inode, "reading block %u", EXT3_I(inode)->i_file_acl); |
1da177e4 LT |
372 | bh = sb_bread(inode->i_sb, EXT3_I(inode)->i_file_acl); |
373 | error = -EIO; | |
374 | if (!bh) | |
375 | goto cleanup; | |
376 | ea_bdebug(bh, "b_count=%d, refcount=%d", | |
377 | atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount)); | |
378 | if (ext3_xattr_check_block(bh)) { | |
e05b6b52 | 379 | ext3_error(inode->i_sb, __func__, |
eee194e7 | 380 | "inode %lu: bad block "E3FSBLK, inode->i_ino, |
1da177e4 LT |
381 | EXT3_I(inode)->i_file_acl); |
382 | error = -EIO; | |
383 | goto cleanup; | |
384 | } | |
385 | ext3_xattr_cache_insert(bh); | |
386 | error = ext3_xattr_list_entries(inode, BFIRST(bh), buffer, buffer_size); | |
387 | ||
388 | cleanup: | |
389 | brelse(bh); | |
390 | ||
391 | return error; | |
392 | } | |
393 | ||
394 | static int | |
395 | ext3_xattr_ibody_list(struct inode *inode, char *buffer, size_t buffer_size) | |
396 | { | |
397 | struct ext3_xattr_ibody_header *header; | |
398 | struct ext3_inode *raw_inode; | |
399 | struct ext3_iloc iloc; | |
400 | void *end; | |
401 | int error; | |
402 | ||
403 | if (!(EXT3_I(inode)->i_state & EXT3_STATE_XATTR)) | |
404 | return 0; | |
405 | error = ext3_get_inode_loc(inode, &iloc); | |
406 | if (error) | |
407 | return error; | |
408 | raw_inode = ext3_raw_inode(&iloc); | |
409 | header = IHDR(inode, raw_inode); | |
410 | end = (void *)raw_inode + EXT3_SB(inode->i_sb)->s_inode_size; | |
411 | error = ext3_xattr_check_names(IFIRST(header), end); | |
412 | if (error) | |
413 | goto cleanup; | |
414 | error = ext3_xattr_list_entries(inode, IFIRST(header), | |
415 | buffer, buffer_size); | |
416 | ||
417 | cleanup: | |
418 | brelse(iloc.bh); | |
419 | return error; | |
420 | } | |
421 | ||
422 | /* | |
423 | * ext3_xattr_list() | |
424 | * | |
425 | * Copy a list of attribute names into the buffer | |
426 | * provided, or compute the buffer size required. | |
427 | * Buffer is NULL to compute the size of the buffer required. | |
428 | * | |
429 | * Returns a negative error number on failure, or the number of bytes | |
430 | * used / required on success. | |
431 | */ | |
15633005 | 432 | static int |
1da177e4 LT |
433 | ext3_xattr_list(struct inode *inode, char *buffer, size_t buffer_size) |
434 | { | |
435 | int i_error, b_error; | |
436 | ||
437 | down_read(&EXT3_I(inode)->xattr_sem); | |
438 | i_error = ext3_xattr_ibody_list(inode, buffer, buffer_size); | |
439 | if (i_error < 0) { | |
440 | b_error = 0; | |
441 | } else { | |
442 | if (buffer) { | |
443 | buffer += i_error; | |
444 | buffer_size -= i_error; | |
445 | } | |
446 | b_error = ext3_xattr_block_list(inode, buffer, buffer_size); | |
447 | if (b_error < 0) | |
448 | i_error = 0; | |
449 | } | |
450 | up_read(&EXT3_I(inode)->xattr_sem); | |
451 | return i_error + b_error; | |
452 | } | |
453 | ||
454 | /* | |
455 | * If the EXT3_FEATURE_COMPAT_EXT_ATTR feature of this file system is | |
456 | * not set, set it. | |
457 | */ | |
458 | static void ext3_xattr_update_super_block(handle_t *handle, | |
459 | struct super_block *sb) | |
460 | { | |
461 | if (EXT3_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_EXT_ATTR)) | |
462 | return; | |
463 | ||
1da177e4 | 464 | if (ext3_journal_get_write_access(handle, EXT3_SB(sb)->s_sbh) == 0) { |
ed2908f3 | 465 | EXT3_SET_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_EXT_ATTR); |
1da177e4 LT |
466 | sb->s_dirt = 1; |
467 | ext3_journal_dirty_metadata(handle, EXT3_SB(sb)->s_sbh); | |
468 | } | |
1da177e4 LT |
469 | } |
470 | ||
471 | /* | |
472 | * Release the xattr block BH: If the reference count is > 1, decrement | |
473 | * it; otherwise free the block. | |
474 | */ | |
475 | static void | |
476 | ext3_xattr_release_block(handle_t *handle, struct inode *inode, | |
477 | struct buffer_head *bh) | |
478 | { | |
479 | struct mb_cache_entry *ce = NULL; | |
8a2bfdcb | 480 | int error = 0; |
1da177e4 LT |
481 | |
482 | ce = mb_cache_entry_get(ext3_xattr_cache, bh->b_bdev, bh->b_blocknr); | |
8a2bfdcb MC |
483 | error = ext3_journal_get_write_access(handle, bh); |
484 | if (error) | |
485 | goto out; | |
486 | ||
487 | lock_buffer(bh); | |
488 | ||
1da177e4 LT |
489 | if (BHDR(bh)->h_refcount == cpu_to_le32(1)) { |
490 | ea_bdebug(bh, "refcount now=0; freeing"); | |
491 | if (ce) | |
492 | mb_cache_entry_free(ce); | |
493 | ext3_free_blocks(handle, inode, bh->b_blocknr, 1); | |
494 | get_bh(bh); | |
495 | ext3_forget(handle, 1, inode, bh, bh->b_blocknr); | |
496 | } else { | |
50e8a289 | 497 | le32_add_cpu(&BHDR(bh)->h_refcount, -1); |
8a2bfdcb | 498 | error = ext3_journal_dirty_metadata(handle, bh); |
105fd108 AM |
499 | if (IS_SYNC(inode)) |
500 | handle->h_sync = 1; | |
8a2bfdcb MC |
501 | DQUOT_FREE_BLOCK(inode, 1); |
502 | ea_bdebug(bh, "refcount now=%d; releasing", | |
503 | le32_to_cpu(BHDR(bh)->h_refcount)); | |
1da177e4 LT |
504 | if (ce) |
505 | mb_cache_entry_release(ce); | |
506 | } | |
8a2bfdcb MC |
507 | unlock_buffer(bh); |
508 | out: | |
509 | ext3_std_error(inode->i_sb, error); | |
510 | return; | |
1da177e4 LT |
511 | } |
512 | ||
513 | struct ext3_xattr_info { | |
514 | int name_index; | |
515 | const char *name; | |
516 | const void *value; | |
517 | size_t value_len; | |
518 | }; | |
519 | ||
520 | struct ext3_xattr_search { | |
521 | struct ext3_xattr_entry *first; | |
522 | void *base; | |
523 | void *end; | |
524 | struct ext3_xattr_entry *here; | |
525 | int not_found; | |
526 | }; | |
527 | ||
528 | static int | |
529 | ext3_xattr_set_entry(struct ext3_xattr_info *i, struct ext3_xattr_search *s) | |
530 | { | |
531 | struct ext3_xattr_entry *last; | |
532 | size_t free, min_offs = s->end - s->base, name_len = strlen(i->name); | |
533 | ||
534 | /* Compute min_offs and last. */ | |
535 | last = s->first; | |
536 | for (; !IS_LAST_ENTRY(last); last = EXT3_XATTR_NEXT(last)) { | |
537 | if (!last->e_value_block && last->e_value_size) { | |
538 | size_t offs = le16_to_cpu(last->e_value_offs); | |
539 | if (offs < min_offs) | |
540 | min_offs = offs; | |
541 | } | |
542 | } | |
543 | free = min_offs - ((void *)last - s->base) - sizeof(__u32); | |
544 | if (!s->not_found) { | |
545 | if (!s->here->e_value_block && s->here->e_value_size) { | |
546 | size_t size = le32_to_cpu(s->here->e_value_size); | |
547 | free += EXT3_XATTR_SIZE(size); | |
548 | } | |
549 | free += EXT3_XATTR_LEN(name_len); | |
550 | } | |
551 | if (i->value) { | |
552 | if (free < EXT3_XATTR_SIZE(i->value_len) || | |
553 | free < EXT3_XATTR_LEN(name_len) + | |
554 | EXT3_XATTR_SIZE(i->value_len)) | |
555 | return -ENOSPC; | |
556 | } | |
557 | ||
558 | if (i->value && s->not_found) { | |
559 | /* Insert the new name. */ | |
560 | size_t size = EXT3_XATTR_LEN(name_len); | |
561 | size_t rest = (void *)last - (void *)s->here + sizeof(__u32); | |
562 | memmove((void *)s->here + size, s->here, rest); | |
563 | memset(s->here, 0, size); | |
564 | s->here->e_name_index = i->name_index; | |
565 | s->here->e_name_len = name_len; | |
566 | memcpy(s->here->e_name, i->name, name_len); | |
567 | } else { | |
568 | if (!s->here->e_value_block && s->here->e_value_size) { | |
569 | void *first_val = s->base + min_offs; | |
570 | size_t offs = le16_to_cpu(s->here->e_value_offs); | |
571 | void *val = s->base + offs; | |
572 | size_t size = EXT3_XATTR_SIZE( | |
573 | le32_to_cpu(s->here->e_value_size)); | |
574 | ||
575 | if (i->value && size == EXT3_XATTR_SIZE(i->value_len)) { | |
576 | /* The old and the new value have the same | |
577 | size. Just replace. */ | |
578 | s->here->e_value_size = | |
579 | cpu_to_le32(i->value_len); | |
580 | memset(val + size - EXT3_XATTR_PAD, 0, | |
581 | EXT3_XATTR_PAD); /* Clear pad bytes. */ | |
582 | memcpy(val, i->value, i->value_len); | |
583 | return 0; | |
584 | } | |
585 | ||
586 | /* Remove the old value. */ | |
587 | memmove(first_val + size, first_val, val - first_val); | |
588 | memset(first_val, 0, size); | |
589 | s->here->e_value_size = 0; | |
590 | s->here->e_value_offs = 0; | |
591 | min_offs += size; | |
592 | ||
593 | /* Adjust all value offsets. */ | |
594 | last = s->first; | |
595 | while (!IS_LAST_ENTRY(last)) { | |
596 | size_t o = le16_to_cpu(last->e_value_offs); | |
597 | if (!last->e_value_block && | |
598 | last->e_value_size && o < offs) | |
599 | last->e_value_offs = | |
600 | cpu_to_le16(o + size); | |
601 | last = EXT3_XATTR_NEXT(last); | |
602 | } | |
603 | } | |
604 | if (!i->value) { | |
605 | /* Remove the old name. */ | |
606 | size_t size = EXT3_XATTR_LEN(name_len); | |
607 | last = ENTRY((void *)last - size); | |
608 | memmove(s->here, (void *)s->here + size, | |
609 | (void *)last - (void *)s->here + sizeof(__u32)); | |
610 | memset(last, 0, size); | |
611 | } | |
612 | } | |
613 | ||
614 | if (i->value) { | |
615 | /* Insert the new value. */ | |
616 | s->here->e_value_size = cpu_to_le32(i->value_len); | |
617 | if (i->value_len) { | |
618 | size_t size = EXT3_XATTR_SIZE(i->value_len); | |
619 | void *val = s->base + min_offs - size; | |
620 | s->here->e_value_offs = cpu_to_le16(min_offs - size); | |
621 | memset(val + size - EXT3_XATTR_PAD, 0, | |
622 | EXT3_XATTR_PAD); /* Clear the pad bytes. */ | |
623 | memcpy(val, i->value, i->value_len); | |
624 | } | |
625 | } | |
626 | return 0; | |
627 | } | |
628 | ||
629 | struct ext3_xattr_block_find { | |
630 | struct ext3_xattr_search s; | |
631 | struct buffer_head *bh; | |
632 | }; | |
633 | ||
381be254 | 634 | static int |
1da177e4 LT |
635 | ext3_xattr_block_find(struct inode *inode, struct ext3_xattr_info *i, |
636 | struct ext3_xattr_block_find *bs) | |
637 | { | |
638 | struct super_block *sb = inode->i_sb; | |
639 | int error; | |
640 | ||
641 | ea_idebug(inode, "name=%d.%s, value=%p, value_len=%ld", | |
642 | i->name_index, i->name, i->value, (long)i->value_len); | |
643 | ||
644 | if (EXT3_I(inode)->i_file_acl) { | |
645 | /* The inode already has an extended attribute block. */ | |
646 | bs->bh = sb_bread(sb, EXT3_I(inode)->i_file_acl); | |
647 | error = -EIO; | |
648 | if (!bs->bh) | |
649 | goto cleanup; | |
650 | ea_bdebug(bs->bh, "b_count=%d, refcount=%d", | |
651 | atomic_read(&(bs->bh->b_count)), | |
652 | le32_to_cpu(BHDR(bs->bh)->h_refcount)); | |
653 | if (ext3_xattr_check_block(bs->bh)) { | |
e05b6b52 | 654 | ext3_error(sb, __func__, |
eee194e7 | 655 | "inode %lu: bad block "E3FSBLK, inode->i_ino, |
1da177e4 LT |
656 | EXT3_I(inode)->i_file_acl); |
657 | error = -EIO; | |
658 | goto cleanup; | |
659 | } | |
660 | /* Find the named attribute. */ | |
661 | bs->s.base = BHDR(bs->bh); | |
662 | bs->s.first = BFIRST(bs->bh); | |
663 | bs->s.end = bs->bh->b_data + bs->bh->b_size; | |
664 | bs->s.here = bs->s.first; | |
665 | error = ext3_xattr_find_entry(&bs->s.here, i->name_index, | |
666 | i->name, bs->bh->b_size, 1); | |
667 | if (error && error != -ENODATA) | |
668 | goto cleanup; | |
669 | bs->s.not_found = error; | |
670 | } | |
671 | error = 0; | |
672 | ||
673 | cleanup: | |
674 | return error; | |
675 | } | |
676 | ||
677 | static int | |
678 | ext3_xattr_block_set(handle_t *handle, struct inode *inode, | |
679 | struct ext3_xattr_info *i, | |
680 | struct ext3_xattr_block_find *bs) | |
681 | { | |
682 | struct super_block *sb = inode->i_sb; | |
683 | struct buffer_head *new_bh = NULL; | |
684 | struct ext3_xattr_search *s = &bs->s; | |
685 | struct mb_cache_entry *ce = NULL; | |
8a2bfdcb | 686 | int error = 0; |
1da177e4 LT |
687 | |
688 | #define header(x) ((struct ext3_xattr_header *)(x)) | |
689 | ||
690 | if (i->value && i->value_len > sb->s_blocksize) | |
691 | return -ENOSPC; | |
692 | if (s->base) { | |
693 | ce = mb_cache_entry_get(ext3_xattr_cache, bs->bh->b_bdev, | |
694 | bs->bh->b_blocknr); | |
8a2bfdcb MC |
695 | error = ext3_journal_get_write_access(handle, bs->bh); |
696 | if (error) | |
697 | goto cleanup; | |
698 | lock_buffer(bs->bh); | |
699 | ||
1da177e4 LT |
700 | if (header(s->base)->h_refcount == cpu_to_le32(1)) { |
701 | if (ce) { | |
702 | mb_cache_entry_free(ce); | |
703 | ce = NULL; | |
704 | } | |
705 | ea_bdebug(bs->bh, "modifying in-place"); | |
1da177e4 LT |
706 | error = ext3_xattr_set_entry(i, s); |
707 | if (!error) { | |
708 | if (!IS_LAST_ENTRY(s->first)) | |
709 | ext3_xattr_rehash(header(s->base), | |
710 | s->here); | |
711 | ext3_xattr_cache_insert(bs->bh); | |
712 | } | |
713 | unlock_buffer(bs->bh); | |
714 | if (error == -EIO) | |
715 | goto bad_block; | |
716 | if (!error) | |
717 | error = ext3_journal_dirty_metadata(handle, | |
718 | bs->bh); | |
719 | if (error) | |
720 | goto cleanup; | |
721 | goto inserted; | |
722 | } else { | |
723 | int offset = (char *)s->here - bs->bh->b_data; | |
724 | ||
8a2bfdcb MC |
725 | unlock_buffer(bs->bh); |
726 | journal_release_buffer(handle, bs->bh); | |
727 | ||
1da177e4 LT |
728 | if (ce) { |
729 | mb_cache_entry_release(ce); | |
730 | ce = NULL; | |
731 | } | |
732 | ea_bdebug(bs->bh, "cloning"); | |
c587f0c0 | 733 | s->base = kmalloc(bs->bh->b_size, GFP_NOFS); |
1da177e4 LT |
734 | error = -ENOMEM; |
735 | if (s->base == NULL) | |
736 | goto cleanup; | |
737 | memcpy(s->base, BHDR(bs->bh), bs->bh->b_size); | |
738 | s->first = ENTRY(header(s->base)+1); | |
739 | header(s->base)->h_refcount = cpu_to_le32(1); | |
740 | s->here = ENTRY(s->base + offset); | |
741 | s->end = s->base + bs->bh->b_size; | |
742 | } | |
743 | } else { | |
744 | /* Allocate a buffer where we construct the new block. */ | |
c587f0c0 | 745 | s->base = kzalloc(sb->s_blocksize, GFP_NOFS); |
1da177e4 LT |
746 | /* assert(header == s->base) */ |
747 | error = -ENOMEM; | |
748 | if (s->base == NULL) | |
749 | goto cleanup; | |
1da177e4 LT |
750 | header(s->base)->h_magic = cpu_to_le32(EXT3_XATTR_MAGIC); |
751 | header(s->base)->h_blocks = cpu_to_le32(1); | |
752 | header(s->base)->h_refcount = cpu_to_le32(1); | |
753 | s->first = ENTRY(header(s->base)+1); | |
754 | s->here = ENTRY(header(s->base)+1); | |
755 | s->end = s->base + sb->s_blocksize; | |
756 | } | |
757 | ||
758 | error = ext3_xattr_set_entry(i, s); | |
759 | if (error == -EIO) | |
760 | goto bad_block; | |
761 | if (error) | |
762 | goto cleanup; | |
763 | if (!IS_LAST_ENTRY(s->first)) | |
764 | ext3_xattr_rehash(header(s->base), s->here); | |
765 | ||
766 | inserted: | |
767 | if (!IS_LAST_ENTRY(s->first)) { | |
768 | new_bh = ext3_xattr_cache_find(inode, header(s->base), &ce); | |
769 | if (new_bh) { | |
770 | /* We found an identical block in the cache. */ | |
771 | if (new_bh == bs->bh) | |
772 | ea_bdebug(new_bh, "keeping"); | |
773 | else { | |
774 | /* The old block is released after updating | |
775 | the inode. */ | |
776 | error = -EDQUOT; | |
777 | if (DQUOT_ALLOC_BLOCK(inode, 1)) | |
778 | goto cleanup; | |
779 | error = ext3_journal_get_write_access(handle, | |
780 | new_bh); | |
781 | if (error) | |
782 | goto cleanup_dquot; | |
783 | lock_buffer(new_bh); | |
50e8a289 | 784 | le32_add_cpu(&BHDR(new_bh)->h_refcount, 1); |
1da177e4 LT |
785 | ea_bdebug(new_bh, "reusing; refcount now=%d", |
786 | le32_to_cpu(BHDR(new_bh)->h_refcount)); | |
787 | unlock_buffer(new_bh); | |
788 | error = ext3_journal_dirty_metadata(handle, | |
789 | new_bh); | |
790 | if (error) | |
791 | goto cleanup_dquot; | |
792 | } | |
793 | mb_cache_entry_release(ce); | |
794 | ce = NULL; | |
795 | } else if (bs->bh && s->base == bs->bh->b_data) { | |
796 | /* We were modifying this block in-place. */ | |
797 | ea_bdebug(bs->bh, "keeping this block"); | |
798 | new_bh = bs->bh; | |
799 | get_bh(new_bh); | |
800 | } else { | |
801 | /* We need to allocate a new block */ | |
1eaafeae AM |
802 | ext3_fsblk_t goal = ext3_group_first_block_no(sb, |
803 | EXT3_I(inode)->i_block_group); | |
1c2bf374 MC |
804 | ext3_fsblk_t block = ext3_new_block(handle, inode, |
805 | goal, &error); | |
1da177e4 LT |
806 | if (error) |
807 | goto cleanup; | |
808 | ea_idebug(inode, "creating block %d", block); | |
809 | ||
810 | new_bh = sb_getblk(sb, block); | |
811 | if (!new_bh) { | |
812 | getblk_failed: | |
813 | ext3_free_blocks(handle, inode, block, 1); | |
814 | error = -EIO; | |
815 | goto cleanup; | |
816 | } | |
817 | lock_buffer(new_bh); | |
818 | error = ext3_journal_get_create_access(handle, new_bh); | |
819 | if (error) { | |
820 | unlock_buffer(new_bh); | |
821 | goto getblk_failed; | |
822 | } | |
823 | memcpy(new_bh->b_data, s->base, new_bh->b_size); | |
824 | set_buffer_uptodate(new_bh); | |
825 | unlock_buffer(new_bh); | |
826 | ext3_xattr_cache_insert(new_bh); | |
827 | error = ext3_journal_dirty_metadata(handle, new_bh); | |
828 | if (error) | |
829 | goto cleanup; | |
830 | } | |
831 | } | |
832 | ||
833 | /* Update the inode. */ | |
834 | EXT3_I(inode)->i_file_acl = new_bh ? new_bh->b_blocknr : 0; | |
835 | ||
836 | /* Drop the previous xattr block. */ | |
837 | if (bs->bh && bs->bh != new_bh) | |
838 | ext3_xattr_release_block(handle, inode, bs->bh); | |
839 | error = 0; | |
840 | ||
841 | cleanup: | |
842 | if (ce) | |
843 | mb_cache_entry_release(ce); | |
844 | brelse(new_bh); | |
845 | if (!(bs->bh && s->base == bs->bh->b_data)) | |
846 | kfree(s->base); | |
847 | ||
848 | return error; | |
849 | ||
850 | cleanup_dquot: | |
851 | DQUOT_FREE_BLOCK(inode, 1); | |
852 | goto cleanup; | |
853 | ||
854 | bad_block: | |
e05b6b52 | 855 | ext3_error(inode->i_sb, __func__, |
eee194e7 | 856 | "inode %lu: bad block "E3FSBLK, inode->i_ino, |
1da177e4 LT |
857 | EXT3_I(inode)->i_file_acl); |
858 | goto cleanup; | |
859 | ||
860 | #undef header | |
861 | } | |
862 | ||
863 | struct ext3_xattr_ibody_find { | |
864 | struct ext3_xattr_search s; | |
865 | struct ext3_iloc iloc; | |
866 | }; | |
867 | ||
381be254 | 868 | static int |
1da177e4 LT |
869 | ext3_xattr_ibody_find(struct inode *inode, struct ext3_xattr_info *i, |
870 | struct ext3_xattr_ibody_find *is) | |
871 | { | |
872 | struct ext3_xattr_ibody_header *header; | |
873 | struct ext3_inode *raw_inode; | |
874 | int error; | |
875 | ||
876 | if (EXT3_I(inode)->i_extra_isize == 0) | |
877 | return 0; | |
878 | raw_inode = ext3_raw_inode(&is->iloc); | |
879 | header = IHDR(inode, raw_inode); | |
880 | is->s.base = is->s.first = IFIRST(header); | |
881 | is->s.here = is->s.first; | |
882 | is->s.end = (void *)raw_inode + EXT3_SB(inode->i_sb)->s_inode_size; | |
883 | if (EXT3_I(inode)->i_state & EXT3_STATE_XATTR) { | |
884 | error = ext3_xattr_check_names(IFIRST(header), is->s.end); | |
885 | if (error) | |
886 | return error; | |
887 | /* Find the named attribute. */ | |
888 | error = ext3_xattr_find_entry(&is->s.here, i->name_index, | |
889 | i->name, is->s.end - | |
890 | (void *)is->s.base, 0); | |
891 | if (error && error != -ENODATA) | |
892 | return error; | |
893 | is->s.not_found = error; | |
894 | } | |
895 | return 0; | |
896 | } | |
897 | ||
898 | static int | |
899 | ext3_xattr_ibody_set(handle_t *handle, struct inode *inode, | |
900 | struct ext3_xattr_info *i, | |
901 | struct ext3_xattr_ibody_find *is) | |
902 | { | |
903 | struct ext3_xattr_ibody_header *header; | |
904 | struct ext3_xattr_search *s = &is->s; | |
905 | int error; | |
906 | ||
907 | if (EXT3_I(inode)->i_extra_isize == 0) | |
908 | return -ENOSPC; | |
909 | error = ext3_xattr_set_entry(i, s); | |
910 | if (error) | |
911 | return error; | |
912 | header = IHDR(inode, ext3_raw_inode(&is->iloc)); | |
913 | if (!IS_LAST_ENTRY(s->first)) { | |
914 | header->h_magic = cpu_to_le32(EXT3_XATTR_MAGIC); | |
915 | EXT3_I(inode)->i_state |= EXT3_STATE_XATTR; | |
916 | } else { | |
917 | header->h_magic = cpu_to_le32(0); | |
918 | EXT3_I(inode)->i_state &= ~EXT3_STATE_XATTR; | |
919 | } | |
920 | return 0; | |
921 | } | |
922 | ||
923 | /* | |
924 | * ext3_xattr_set_handle() | |
925 | * | |
926 | * Create, replace or remove an extended attribute for this inode. Buffer | |
927 | * is NULL to remove an existing extended attribute, and non-NULL to | |
928 | * either replace an existing extended attribute, or create a new extended | |
929 | * attribute. The flags XATTR_REPLACE and XATTR_CREATE | |
930 | * specify that an extended attribute must exist and must not exist | |
931 | * previous to the call, respectively. | |
932 | * | |
933 | * Returns 0, or a negative error number on failure. | |
934 | */ | |
935 | int | |
936 | ext3_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index, | |
937 | const char *name, const void *value, size_t value_len, | |
938 | int flags) | |
939 | { | |
940 | struct ext3_xattr_info i = { | |
941 | .name_index = name_index, | |
942 | .name = name, | |
943 | .value = value, | |
944 | .value_len = value_len, | |
945 | ||
946 | }; | |
947 | struct ext3_xattr_ibody_find is = { | |
948 | .s = { .not_found = -ENODATA, }, | |
949 | }; | |
950 | struct ext3_xattr_block_find bs = { | |
951 | .s = { .not_found = -ENODATA, }, | |
952 | }; | |
953 | int error; | |
954 | ||
1da177e4 LT |
955 | if (!name) |
956 | return -EINVAL; | |
957 | if (strlen(name) > 255) | |
958 | return -ERANGE; | |
959 | down_write(&EXT3_I(inode)->xattr_sem); | |
960 | error = ext3_get_inode_loc(inode, &is.iloc); | |
961 | if (error) | |
962 | goto cleanup; | |
963 | ||
964 | if (EXT3_I(inode)->i_state & EXT3_STATE_NEW) { | |
965 | struct ext3_inode *raw_inode = ext3_raw_inode(&is.iloc); | |
966 | memset(raw_inode, 0, EXT3_SB(inode->i_sb)->s_inode_size); | |
967 | EXT3_I(inode)->i_state &= ~EXT3_STATE_NEW; | |
968 | } | |
969 | ||
970 | error = ext3_xattr_ibody_find(inode, &i, &is); | |
971 | if (error) | |
972 | goto cleanup; | |
973 | if (is.s.not_found) | |
974 | error = ext3_xattr_block_find(inode, &i, &bs); | |
975 | if (error) | |
976 | goto cleanup; | |
977 | if (is.s.not_found && bs.s.not_found) { | |
978 | error = -ENODATA; | |
979 | if (flags & XATTR_REPLACE) | |
980 | goto cleanup; | |
981 | error = 0; | |
982 | if (!value) | |
983 | goto cleanup; | |
984 | } else { | |
985 | error = -EEXIST; | |
986 | if (flags & XATTR_CREATE) | |
987 | goto cleanup; | |
988 | } | |
989 | error = ext3_journal_get_write_access(handle, is.iloc.bh); | |
990 | if (error) | |
991 | goto cleanup; | |
992 | if (!value) { | |
993 | if (!is.s.not_found) | |
994 | error = ext3_xattr_ibody_set(handle, inode, &i, &is); | |
995 | else if (!bs.s.not_found) | |
996 | error = ext3_xattr_block_set(handle, inode, &i, &bs); | |
997 | } else { | |
998 | error = ext3_xattr_ibody_set(handle, inode, &i, &is); | |
999 | if (!error && !bs.s.not_found) { | |
1000 | i.value = NULL; | |
1001 | error = ext3_xattr_block_set(handle, inode, &i, &bs); | |
1002 | } else if (error == -ENOSPC) { | |
1003 | error = ext3_xattr_block_set(handle, inode, &i, &bs); | |
1004 | if (error) | |
1005 | goto cleanup; | |
1006 | if (!is.s.not_found) { | |
1007 | i.value = NULL; | |
1008 | error = ext3_xattr_ibody_set(handle, inode, &i, | |
1009 | &is); | |
1010 | } | |
1011 | } | |
1012 | } | |
1013 | if (!error) { | |
1014 | ext3_xattr_update_super_block(handle, inode->i_sb); | |
1015 | inode->i_ctime = CURRENT_TIME_SEC; | |
1016 | error = ext3_mark_iloc_dirty(handle, inode, &is.iloc); | |
1017 | /* | |
1018 | * The bh is consumed by ext3_mark_iloc_dirty, even with | |
1019 | * error != 0. | |
1020 | */ | |
1021 | is.iloc.bh = NULL; | |
1022 | if (IS_SYNC(inode)) | |
1023 | handle->h_sync = 1; | |
1024 | } | |
1025 | ||
1026 | cleanup: | |
1027 | brelse(is.iloc.bh); | |
1028 | brelse(bs.bh); | |
1029 | up_write(&EXT3_I(inode)->xattr_sem); | |
1030 | return error; | |
1031 | } | |
1032 | ||
1033 | /* | |
1034 | * ext3_xattr_set() | |
1035 | * | |
1036 | * Like ext3_xattr_set_handle, but start from an inode. This extended | |
1037 | * attribute modification is a filesystem transaction by itself. | |
1038 | * | |
1039 | * Returns 0, or a negative error number on failure. | |
1040 | */ | |
1041 | int | |
1042 | ext3_xattr_set(struct inode *inode, int name_index, const char *name, | |
1043 | const void *value, size_t value_len, int flags) | |
1044 | { | |
1045 | handle_t *handle; | |
1046 | int error, retries = 0; | |
1047 | ||
1048 | retry: | |
1f54587b | 1049 | handle = ext3_journal_start(inode, EXT3_DATA_TRANS_BLOCKS(inode->i_sb)); |
1da177e4 LT |
1050 | if (IS_ERR(handle)) { |
1051 | error = PTR_ERR(handle); | |
1052 | } else { | |
1053 | int error2; | |
1054 | ||
1055 | error = ext3_xattr_set_handle(handle, inode, name_index, name, | |
1056 | value, value_len, flags); | |
1057 | error2 = ext3_journal_stop(handle); | |
1058 | if (error == -ENOSPC && | |
1059 | ext3_should_retry_alloc(inode->i_sb, &retries)) | |
1060 | goto retry; | |
1061 | if (error == 0) | |
1062 | error = error2; | |
1063 | } | |
1064 | ||
1065 | return error; | |
1066 | } | |
1067 | ||
1068 | /* | |
1069 | * ext3_xattr_delete_inode() | |
1070 | * | |
1071 | * Free extended attribute resources associated with this inode. This | |
1072 | * is called immediately before an inode is freed. We have exclusive | |
1073 | * access to the inode. | |
1074 | */ | |
1075 | void | |
1076 | ext3_xattr_delete_inode(handle_t *handle, struct inode *inode) | |
1077 | { | |
1078 | struct buffer_head *bh = NULL; | |
1079 | ||
1080 | if (!EXT3_I(inode)->i_file_acl) | |
1081 | goto cleanup; | |
1082 | bh = sb_bread(inode->i_sb, EXT3_I(inode)->i_file_acl); | |
1083 | if (!bh) { | |
e05b6b52 | 1084 | ext3_error(inode->i_sb, __func__, |
eee194e7 | 1085 | "inode %lu: block "E3FSBLK" read error", inode->i_ino, |
1da177e4 LT |
1086 | EXT3_I(inode)->i_file_acl); |
1087 | goto cleanup; | |
1088 | } | |
1089 | if (BHDR(bh)->h_magic != cpu_to_le32(EXT3_XATTR_MAGIC) || | |
1090 | BHDR(bh)->h_blocks != cpu_to_le32(1)) { | |
e05b6b52 | 1091 | ext3_error(inode->i_sb, __func__, |
eee194e7 | 1092 | "inode %lu: bad block "E3FSBLK, inode->i_ino, |
1da177e4 LT |
1093 | EXT3_I(inode)->i_file_acl); |
1094 | goto cleanup; | |
1095 | } | |
1096 | ext3_xattr_release_block(handle, inode, bh); | |
1097 | EXT3_I(inode)->i_file_acl = 0; | |
1098 | ||
1099 | cleanup: | |
1100 | brelse(bh); | |
1101 | } | |
1102 | ||
1103 | /* | |
1104 | * ext3_xattr_put_super() | |
1105 | * | |
1106 | * This is called when a file system is unmounted. | |
1107 | */ | |
1108 | void | |
1109 | ext3_xattr_put_super(struct super_block *sb) | |
1110 | { | |
8c52ab42 | 1111 | mb_cache_shrink(sb->s_bdev); |
1da177e4 LT |
1112 | } |
1113 | ||
1114 | /* | |
1115 | * ext3_xattr_cache_insert() | |
1116 | * | |
1117 | * Create a new entry in the extended attribute cache, and insert | |
1118 | * it unless such an entry is already in the cache. | |
1119 | * | |
1120 | * Returns 0, or a negative error number on failure. | |
1121 | */ | |
1122 | static void | |
1123 | ext3_xattr_cache_insert(struct buffer_head *bh) | |
1124 | { | |
1125 | __u32 hash = le32_to_cpu(BHDR(bh)->h_hash); | |
1126 | struct mb_cache_entry *ce; | |
1127 | int error; | |
1128 | ||
335e92e8 | 1129 | ce = mb_cache_entry_alloc(ext3_xattr_cache, GFP_NOFS); |
1da177e4 LT |
1130 | if (!ce) { |
1131 | ea_bdebug(bh, "out of memory"); | |
1132 | return; | |
1133 | } | |
1134 | error = mb_cache_entry_insert(ce, bh->b_bdev, bh->b_blocknr, &hash); | |
1135 | if (error) { | |
1136 | mb_cache_entry_free(ce); | |
1137 | if (error == -EBUSY) { | |
1138 | ea_bdebug(bh, "already in cache"); | |
1139 | error = 0; | |
1140 | } | |
1141 | } else { | |
1142 | ea_bdebug(bh, "inserting [%x]", (int)hash); | |
1143 | mb_cache_entry_release(ce); | |
1144 | } | |
1145 | } | |
1146 | ||
1147 | /* | |
1148 | * ext3_xattr_cmp() | |
1149 | * | |
1150 | * Compare two extended attribute blocks for equality. | |
1151 | * | |
1152 | * Returns 0 if the blocks are equal, 1 if they differ, and | |
1153 | * a negative error number on errors. | |
1154 | */ | |
1155 | static int | |
1156 | ext3_xattr_cmp(struct ext3_xattr_header *header1, | |
1157 | struct ext3_xattr_header *header2) | |
1158 | { | |
1159 | struct ext3_xattr_entry *entry1, *entry2; | |
1160 | ||
1161 | entry1 = ENTRY(header1+1); | |
1162 | entry2 = ENTRY(header2+1); | |
1163 | while (!IS_LAST_ENTRY(entry1)) { | |
1164 | if (IS_LAST_ENTRY(entry2)) | |
1165 | return 1; | |
1166 | if (entry1->e_hash != entry2->e_hash || | |
1167 | entry1->e_name_index != entry2->e_name_index || | |
1168 | entry1->e_name_len != entry2->e_name_len || | |
1169 | entry1->e_value_size != entry2->e_value_size || | |
1170 | memcmp(entry1->e_name, entry2->e_name, entry1->e_name_len)) | |
1171 | return 1; | |
1172 | if (entry1->e_value_block != 0 || entry2->e_value_block != 0) | |
1173 | return -EIO; | |
1174 | if (memcmp((char *)header1 + le16_to_cpu(entry1->e_value_offs), | |
1175 | (char *)header2 + le16_to_cpu(entry2->e_value_offs), | |
1176 | le32_to_cpu(entry1->e_value_size))) | |
1177 | return 1; | |
1178 | ||
1179 | entry1 = EXT3_XATTR_NEXT(entry1); | |
1180 | entry2 = EXT3_XATTR_NEXT(entry2); | |
1181 | } | |
1182 | if (!IS_LAST_ENTRY(entry2)) | |
1183 | return 1; | |
1184 | return 0; | |
1185 | } | |
1186 | ||
1187 | /* | |
1188 | * ext3_xattr_cache_find() | |
1189 | * | |
1190 | * Find an identical extended attribute block. | |
1191 | * | |
1192 | * Returns a pointer to the block found, or NULL if such a block was | |
1193 | * not found or an error occurred. | |
1194 | */ | |
1195 | static struct buffer_head * | |
1196 | ext3_xattr_cache_find(struct inode *inode, struct ext3_xattr_header *header, | |
1197 | struct mb_cache_entry **pce) | |
1198 | { | |
1199 | __u32 hash = le32_to_cpu(header->h_hash); | |
1200 | struct mb_cache_entry *ce; | |
1201 | ||
1202 | if (!header->h_hash) | |
1203 | return NULL; /* never share */ | |
1204 | ea_idebug(inode, "looking for cached blocks [%x]", (int)hash); | |
1205 | again: | |
1206 | ce = mb_cache_entry_find_first(ext3_xattr_cache, 0, | |
1207 | inode->i_sb->s_bdev, hash); | |
1208 | while (ce) { | |
1209 | struct buffer_head *bh; | |
1210 | ||
1211 | if (IS_ERR(ce)) { | |
1212 | if (PTR_ERR(ce) == -EAGAIN) | |
1213 | goto again; | |
1214 | break; | |
1215 | } | |
1216 | bh = sb_bread(inode->i_sb, ce->e_block); | |
1217 | if (!bh) { | |
e05b6b52 | 1218 | ext3_error(inode->i_sb, __func__, |
eee194e7 | 1219 | "inode %lu: block %lu read error", |
1da177e4 LT |
1220 | inode->i_ino, (unsigned long) ce->e_block); |
1221 | } else if (le32_to_cpu(BHDR(bh)->h_refcount) >= | |
1222 | EXT3_XATTR_REFCOUNT_MAX) { | |
1c2bf374 | 1223 | ea_idebug(inode, "block %lu refcount %d>=%d", |
1da177e4 LT |
1224 | (unsigned long) ce->e_block, |
1225 | le32_to_cpu(BHDR(bh)->h_refcount), | |
1226 | EXT3_XATTR_REFCOUNT_MAX); | |
1227 | } else if (ext3_xattr_cmp(header, BHDR(bh)) == 0) { | |
1228 | *pce = ce; | |
1229 | return bh; | |
1230 | } | |
1231 | brelse(bh); | |
1232 | ce = mb_cache_entry_find_next(ce, 0, inode->i_sb->s_bdev, hash); | |
1233 | } | |
1234 | return NULL; | |
1235 | } | |
1236 | ||
1237 | #define NAME_HASH_SHIFT 5 | |
1238 | #define VALUE_HASH_SHIFT 16 | |
1239 | ||
1240 | /* | |
1241 | * ext3_xattr_hash_entry() | |
1242 | * | |
1243 | * Compute the hash of an extended attribute. | |
1244 | */ | |
1245 | static inline void ext3_xattr_hash_entry(struct ext3_xattr_header *header, | |
1246 | struct ext3_xattr_entry *entry) | |
1247 | { | |
1248 | __u32 hash = 0; | |
1249 | char *name = entry->e_name; | |
1250 | int n; | |
1251 | ||
1252 | for (n=0; n < entry->e_name_len; n++) { | |
1253 | hash = (hash << NAME_HASH_SHIFT) ^ | |
1254 | (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^ | |
1255 | *name++; | |
1256 | } | |
1257 | ||
1258 | if (entry->e_value_block == 0 && entry->e_value_size != 0) { | |
1259 | __le32 *value = (__le32 *)((char *)header + | |
1260 | le16_to_cpu(entry->e_value_offs)); | |
1261 | for (n = (le32_to_cpu(entry->e_value_size) + | |
1262 | EXT3_XATTR_ROUND) >> EXT3_XATTR_PAD_BITS; n; n--) { | |
1263 | hash = (hash << VALUE_HASH_SHIFT) ^ | |
1264 | (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^ | |
1265 | le32_to_cpu(*value++); | |
1266 | } | |
1267 | } | |
1268 | entry->e_hash = cpu_to_le32(hash); | |
1269 | } | |
1270 | ||
1271 | #undef NAME_HASH_SHIFT | |
1272 | #undef VALUE_HASH_SHIFT | |
1273 | ||
1274 | #define BLOCK_HASH_SHIFT 16 | |
1275 | ||
1276 | /* | |
1277 | * ext3_xattr_rehash() | |
1278 | * | |
1279 | * Re-compute the extended attribute hash value after an entry has changed. | |
1280 | */ | |
1281 | static void ext3_xattr_rehash(struct ext3_xattr_header *header, | |
1282 | struct ext3_xattr_entry *entry) | |
1283 | { | |
1284 | struct ext3_xattr_entry *here; | |
1285 | __u32 hash = 0; | |
1286 | ||
1287 | ext3_xattr_hash_entry(header, entry); | |
1288 | here = ENTRY(header+1); | |
1289 | while (!IS_LAST_ENTRY(here)) { | |
1290 | if (!here->e_hash) { | |
1291 | /* Block is not shared if an entry's hash value == 0 */ | |
1292 | hash = 0; | |
1293 | break; | |
1294 | } | |
1295 | hash = (hash << BLOCK_HASH_SHIFT) ^ | |
1296 | (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^ | |
1297 | le32_to_cpu(here->e_hash); | |
1298 | here = EXT3_XATTR_NEXT(here); | |
1299 | } | |
1300 | header->h_hash = cpu_to_le32(hash); | |
1301 | } | |
1302 | ||
1303 | #undef BLOCK_HASH_SHIFT | |
1304 | ||
1305 | int __init | |
1306 | init_ext3_xattr(void) | |
1307 | { | |
1308 | ext3_xattr_cache = mb_cache_create("ext3_xattr", NULL, | |
1309 | sizeof(struct mb_cache_entry) + | |
1310 | sizeof(((struct mb_cache_entry *) 0)->e_indexes[0]), 1, 6); | |
1311 | if (!ext3_xattr_cache) | |
1312 | return -ENOMEM; | |
1313 | return 0; | |
1314 | } | |
1315 | ||
1316 | void | |
1317 | exit_ext3_xattr(void) | |
1318 | { | |
1319 | if (ext3_xattr_cache) | |
1320 | mb_cache_destroy(ext3_xattr_cache); | |
1321 | ext3_xattr_cache = NULL; | |
1322 | } |