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Commit | Line | Data |
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ac27a0ec | 1 | /* |
617ba13b | 2 | * linux/fs/ext4/xattr.c |
ac27a0ec DK |
3 | * |
4 | * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de> | |
5 | * | |
6 | * Fix by Harrison Xing <harrison@mountainviewdata.com>. | |
617ba13b | 7 | * Ext4 code with a lot of help from Eric Jarman <ejarman@acm.org>. |
ac27a0ec DK |
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 | * ---------------- | |
617ba13b | 46 | * EXT4_I(inode)->i_file_acl is protected by EXT4_I(inode)->xattr_sem. |
ac27a0ec DK |
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> | |
ac27a0ec DK |
56 | #include <linux/mbcache.h> |
57 | #include <linux/quotaops.h> | |
58 | #include <linux/rwsem.h> | |
3dcf5451 CH |
59 | #include "ext4_jbd2.h" |
60 | #include "ext4.h" | |
ac27a0ec DK |
61 | #include "xattr.h" |
62 | #include "acl.h" | |
63 | ||
617ba13b MC |
64 | #define BHDR(bh) ((struct ext4_xattr_header *)((bh)->b_data)) |
65 | #define ENTRY(ptr) ((struct ext4_xattr_entry *)(ptr)) | |
ac27a0ec DK |
66 | #define BFIRST(bh) ENTRY(BHDR(bh)+1) |
67 | #define IS_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0) | |
68 | ||
617ba13b | 69 | #ifdef EXT4_XATTR_DEBUG |
ac27a0ec DK |
70 | # define ea_idebug(inode, f...) do { \ |
71 | printk(KERN_DEBUG "inode %s:%lu: ", \ | |
72 | inode->i_sb->s_id, inode->i_ino); \ | |
73 | printk(f); \ | |
74 | printk("\n"); \ | |
75 | } while (0) | |
76 | # define ea_bdebug(bh, f...) do { \ | |
77 | char b[BDEVNAME_SIZE]; \ | |
78 | printk(KERN_DEBUG "block %s:%lu: ", \ | |
79 | bdevname(bh->b_bdev, b), \ | |
80 | (unsigned long) bh->b_blocknr); \ | |
81 | printk(f); \ | |
82 | printk("\n"); \ | |
83 | } while (0) | |
84 | #else | |
85 | # define ea_idebug(f...) | |
86 | # define ea_bdebug(f...) | |
87 | #endif | |
88 | ||
617ba13b MC |
89 | static void ext4_xattr_cache_insert(struct buffer_head *); |
90 | static struct buffer_head *ext4_xattr_cache_find(struct inode *, | |
91 | struct ext4_xattr_header *, | |
ac27a0ec | 92 | struct mb_cache_entry **); |
617ba13b MC |
93 | static void ext4_xattr_rehash(struct ext4_xattr_header *, |
94 | struct ext4_xattr_entry *); | |
431547b3 | 95 | static int ext4_xattr_list(struct dentry *dentry, char *buffer, |
d3a95d47 | 96 | size_t buffer_size); |
ac27a0ec | 97 | |
617ba13b | 98 | static struct mb_cache *ext4_xattr_cache; |
ac27a0ec | 99 | |
617ba13b MC |
100 | static struct xattr_handler *ext4_xattr_handler_map[] = { |
101 | [EXT4_XATTR_INDEX_USER] = &ext4_xattr_user_handler, | |
03010a33 | 102 | #ifdef CONFIG_EXT4_FS_POSIX_ACL |
617ba13b MC |
103 | [EXT4_XATTR_INDEX_POSIX_ACL_ACCESS] = &ext4_xattr_acl_access_handler, |
104 | [EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT] = &ext4_xattr_acl_default_handler, | |
ac27a0ec | 105 | #endif |
617ba13b | 106 | [EXT4_XATTR_INDEX_TRUSTED] = &ext4_xattr_trusted_handler, |
03010a33 | 107 | #ifdef CONFIG_EXT4_FS_SECURITY |
617ba13b | 108 | [EXT4_XATTR_INDEX_SECURITY] = &ext4_xattr_security_handler, |
ac27a0ec DK |
109 | #endif |
110 | }; | |
111 | ||
617ba13b MC |
112 | struct xattr_handler *ext4_xattr_handlers[] = { |
113 | &ext4_xattr_user_handler, | |
114 | &ext4_xattr_trusted_handler, | |
03010a33 | 115 | #ifdef CONFIG_EXT4_FS_POSIX_ACL |
617ba13b MC |
116 | &ext4_xattr_acl_access_handler, |
117 | &ext4_xattr_acl_default_handler, | |
ac27a0ec | 118 | #endif |
03010a33 | 119 | #ifdef CONFIG_EXT4_FS_SECURITY |
617ba13b | 120 | &ext4_xattr_security_handler, |
ac27a0ec DK |
121 | #endif |
122 | NULL | |
123 | }; | |
124 | ||
125 | static inline struct xattr_handler * | |
617ba13b | 126 | ext4_xattr_handler(int name_index) |
ac27a0ec DK |
127 | { |
128 | struct xattr_handler *handler = NULL; | |
129 | ||
617ba13b MC |
130 | if (name_index > 0 && name_index < ARRAY_SIZE(ext4_xattr_handler_map)) |
131 | handler = ext4_xattr_handler_map[name_index]; | |
ac27a0ec DK |
132 | return handler; |
133 | } | |
134 | ||
135 | /* | |
136 | * Inode operation listxattr() | |
137 | * | |
138 | * dentry->d_inode->i_mutex: don't care | |
139 | */ | |
140 | ssize_t | |
617ba13b | 141 | ext4_listxattr(struct dentry *dentry, char *buffer, size_t size) |
ac27a0ec | 142 | { |
431547b3 | 143 | return ext4_xattr_list(dentry, buffer, size); |
ac27a0ec DK |
144 | } |
145 | ||
146 | static int | |
617ba13b | 147 | ext4_xattr_check_names(struct ext4_xattr_entry *entry, void *end) |
ac27a0ec DK |
148 | { |
149 | while (!IS_LAST_ENTRY(entry)) { | |
617ba13b | 150 | struct ext4_xattr_entry *next = EXT4_XATTR_NEXT(entry); |
ac27a0ec DK |
151 | if ((void *)next >= end) |
152 | return -EIO; | |
153 | entry = next; | |
154 | } | |
155 | return 0; | |
156 | } | |
157 | ||
158 | static inline int | |
617ba13b | 159 | ext4_xattr_check_block(struct buffer_head *bh) |
ac27a0ec DK |
160 | { |
161 | int error; | |
162 | ||
617ba13b | 163 | if (BHDR(bh)->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC) || |
ac27a0ec DK |
164 | BHDR(bh)->h_blocks != cpu_to_le32(1)) |
165 | return -EIO; | |
617ba13b | 166 | error = ext4_xattr_check_names(BFIRST(bh), bh->b_data + bh->b_size); |
ac27a0ec DK |
167 | return error; |
168 | } | |
169 | ||
170 | static inline int | |
617ba13b | 171 | ext4_xattr_check_entry(struct ext4_xattr_entry *entry, size_t size) |
ac27a0ec DK |
172 | { |
173 | size_t value_size = le32_to_cpu(entry->e_value_size); | |
174 | ||
175 | if (entry->e_value_block != 0 || value_size > size || | |
176 | le16_to_cpu(entry->e_value_offs) + value_size > size) | |
177 | return -EIO; | |
178 | return 0; | |
179 | } | |
180 | ||
181 | static int | |
617ba13b | 182 | ext4_xattr_find_entry(struct ext4_xattr_entry **pentry, int name_index, |
ac27a0ec DK |
183 | const char *name, size_t size, int sorted) |
184 | { | |
617ba13b | 185 | struct ext4_xattr_entry *entry; |
ac27a0ec DK |
186 | size_t name_len; |
187 | int cmp = 1; | |
188 | ||
189 | if (name == NULL) | |
190 | return -EINVAL; | |
191 | name_len = strlen(name); | |
192 | entry = *pentry; | |
617ba13b | 193 | for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) { |
ac27a0ec DK |
194 | cmp = name_index - entry->e_name_index; |
195 | if (!cmp) | |
196 | cmp = name_len - entry->e_name_len; | |
197 | if (!cmp) | |
198 | cmp = memcmp(name, entry->e_name, name_len); | |
199 | if (cmp <= 0 && (sorted || cmp == 0)) | |
200 | break; | |
201 | } | |
202 | *pentry = entry; | |
617ba13b | 203 | if (!cmp && ext4_xattr_check_entry(entry, size)) |
ac27a0ec DK |
204 | return -EIO; |
205 | return cmp ? -ENODATA : 0; | |
206 | } | |
207 | ||
208 | static int | |
617ba13b | 209 | ext4_xattr_block_get(struct inode *inode, int name_index, const char *name, |
ac27a0ec DK |
210 | void *buffer, size_t buffer_size) |
211 | { | |
212 | struct buffer_head *bh = NULL; | |
617ba13b | 213 | struct ext4_xattr_entry *entry; |
ac27a0ec DK |
214 | size_t size; |
215 | int error; | |
216 | ||
217 | ea_idebug(inode, "name=%d.%s, buffer=%p, buffer_size=%ld", | |
218 | name_index, name, buffer, (long)buffer_size); | |
219 | ||
220 | error = -ENODATA; | |
617ba13b | 221 | if (!EXT4_I(inode)->i_file_acl) |
ac27a0ec | 222 | goto cleanup; |
617ba13b MC |
223 | ea_idebug(inode, "reading block %u", EXT4_I(inode)->i_file_acl); |
224 | bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl); | |
ac27a0ec DK |
225 | if (!bh) |
226 | goto cleanup; | |
227 | ea_bdebug(bh, "b_count=%d, refcount=%d", | |
228 | atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount)); | |
617ba13b | 229 | if (ext4_xattr_check_block(bh)) { |
12062ddd ES |
230 | bad_block: |
231 | ext4_error(inode->i_sb, | |
2ae02107 | 232 | "inode %lu: bad block %llu", inode->i_ino, |
617ba13b | 233 | EXT4_I(inode)->i_file_acl); |
ac27a0ec DK |
234 | error = -EIO; |
235 | goto cleanup; | |
236 | } | |
617ba13b | 237 | ext4_xattr_cache_insert(bh); |
ac27a0ec | 238 | entry = BFIRST(bh); |
617ba13b | 239 | error = ext4_xattr_find_entry(&entry, name_index, name, bh->b_size, 1); |
ac27a0ec DK |
240 | if (error == -EIO) |
241 | goto bad_block; | |
242 | if (error) | |
243 | goto cleanup; | |
244 | size = le32_to_cpu(entry->e_value_size); | |
245 | if (buffer) { | |
246 | error = -ERANGE; | |
247 | if (size > buffer_size) | |
248 | goto cleanup; | |
249 | memcpy(buffer, bh->b_data + le16_to_cpu(entry->e_value_offs), | |
250 | size); | |
251 | } | |
252 | error = size; | |
253 | ||
254 | cleanup: | |
255 | brelse(bh); | |
256 | return error; | |
257 | } | |
258 | ||
259 | static int | |
617ba13b | 260 | ext4_xattr_ibody_get(struct inode *inode, int name_index, const char *name, |
ac27a0ec DK |
261 | void *buffer, size_t buffer_size) |
262 | { | |
617ba13b MC |
263 | struct ext4_xattr_ibody_header *header; |
264 | struct ext4_xattr_entry *entry; | |
265 | struct ext4_inode *raw_inode; | |
266 | struct ext4_iloc iloc; | |
ac27a0ec DK |
267 | size_t size; |
268 | void *end; | |
269 | int error; | |
270 | ||
19f5fb7a | 271 | if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR)) |
ac27a0ec | 272 | return -ENODATA; |
617ba13b | 273 | error = ext4_get_inode_loc(inode, &iloc); |
ac27a0ec DK |
274 | if (error) |
275 | return error; | |
617ba13b | 276 | raw_inode = ext4_raw_inode(&iloc); |
ac27a0ec DK |
277 | header = IHDR(inode, raw_inode); |
278 | entry = IFIRST(header); | |
617ba13b MC |
279 | end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; |
280 | error = ext4_xattr_check_names(entry, end); | |
ac27a0ec DK |
281 | if (error) |
282 | goto cleanup; | |
617ba13b | 283 | error = ext4_xattr_find_entry(&entry, name_index, name, |
ac27a0ec DK |
284 | end - (void *)entry, 0); |
285 | if (error) | |
286 | goto cleanup; | |
287 | size = le32_to_cpu(entry->e_value_size); | |
288 | if (buffer) { | |
289 | error = -ERANGE; | |
290 | if (size > buffer_size) | |
291 | goto cleanup; | |
292 | memcpy(buffer, (void *)IFIRST(header) + | |
293 | le16_to_cpu(entry->e_value_offs), size); | |
294 | } | |
295 | error = size; | |
296 | ||
297 | cleanup: | |
298 | brelse(iloc.bh); | |
299 | return error; | |
300 | } | |
301 | ||
302 | /* | |
617ba13b | 303 | * ext4_xattr_get() |
ac27a0ec DK |
304 | * |
305 | * Copy an extended attribute into the buffer | |
306 | * provided, or compute the buffer size required. | |
307 | * Buffer is NULL to compute the size of the buffer required. | |
308 | * | |
309 | * Returns a negative error number on failure, or the number of bytes | |
310 | * used / required on success. | |
311 | */ | |
312 | int | |
617ba13b | 313 | ext4_xattr_get(struct inode *inode, int name_index, const char *name, |
ac27a0ec DK |
314 | void *buffer, size_t buffer_size) |
315 | { | |
316 | int error; | |
317 | ||
617ba13b MC |
318 | down_read(&EXT4_I(inode)->xattr_sem); |
319 | error = ext4_xattr_ibody_get(inode, name_index, name, buffer, | |
ac27a0ec DK |
320 | buffer_size); |
321 | if (error == -ENODATA) | |
617ba13b | 322 | error = ext4_xattr_block_get(inode, name_index, name, buffer, |
ac27a0ec | 323 | buffer_size); |
617ba13b | 324 | up_read(&EXT4_I(inode)->xattr_sem); |
ac27a0ec DK |
325 | return error; |
326 | } | |
327 | ||
328 | static int | |
431547b3 | 329 | ext4_xattr_list_entries(struct dentry *dentry, struct ext4_xattr_entry *entry, |
ac27a0ec DK |
330 | char *buffer, size_t buffer_size) |
331 | { | |
332 | size_t rest = buffer_size; | |
333 | ||
617ba13b | 334 | for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) { |
ac27a0ec | 335 | struct xattr_handler *handler = |
617ba13b | 336 | ext4_xattr_handler(entry->e_name_index); |
ac27a0ec DK |
337 | |
338 | if (handler) { | |
431547b3 | 339 | size_t size = handler->list(dentry, buffer, rest, |
ac27a0ec | 340 | entry->e_name, |
431547b3 CH |
341 | entry->e_name_len, |
342 | handler->flags); | |
ac27a0ec DK |
343 | if (buffer) { |
344 | if (size > rest) | |
345 | return -ERANGE; | |
346 | buffer += size; | |
347 | } | |
348 | rest -= size; | |
349 | } | |
350 | } | |
351 | return buffer_size - rest; | |
352 | } | |
353 | ||
354 | static int | |
431547b3 | 355 | ext4_xattr_block_list(struct dentry *dentry, char *buffer, size_t buffer_size) |
ac27a0ec | 356 | { |
431547b3 | 357 | struct inode *inode = dentry->d_inode; |
ac27a0ec DK |
358 | struct buffer_head *bh = NULL; |
359 | int error; | |
360 | ||
361 | ea_idebug(inode, "buffer=%p, buffer_size=%ld", | |
362 | buffer, (long)buffer_size); | |
363 | ||
364 | error = 0; | |
617ba13b | 365 | if (!EXT4_I(inode)->i_file_acl) |
ac27a0ec | 366 | goto cleanup; |
617ba13b MC |
367 | ea_idebug(inode, "reading block %u", EXT4_I(inode)->i_file_acl); |
368 | bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl); | |
ac27a0ec DK |
369 | error = -EIO; |
370 | if (!bh) | |
371 | goto cleanup; | |
372 | ea_bdebug(bh, "b_count=%d, refcount=%d", | |
373 | atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount)); | |
617ba13b | 374 | if (ext4_xattr_check_block(bh)) { |
12062ddd | 375 | ext4_error(inode->i_sb, |
2ae02107 | 376 | "inode %lu: bad block %llu", inode->i_ino, |
617ba13b | 377 | EXT4_I(inode)->i_file_acl); |
ac27a0ec DK |
378 | error = -EIO; |
379 | goto cleanup; | |
380 | } | |
617ba13b | 381 | ext4_xattr_cache_insert(bh); |
431547b3 | 382 | error = ext4_xattr_list_entries(dentry, BFIRST(bh), buffer, buffer_size); |
ac27a0ec DK |
383 | |
384 | cleanup: | |
385 | brelse(bh); | |
386 | ||
387 | return error; | |
388 | } | |
389 | ||
390 | static int | |
431547b3 | 391 | ext4_xattr_ibody_list(struct dentry *dentry, char *buffer, size_t buffer_size) |
ac27a0ec | 392 | { |
431547b3 | 393 | struct inode *inode = dentry->d_inode; |
617ba13b MC |
394 | struct ext4_xattr_ibody_header *header; |
395 | struct ext4_inode *raw_inode; | |
396 | struct ext4_iloc iloc; | |
ac27a0ec DK |
397 | void *end; |
398 | int error; | |
399 | ||
19f5fb7a | 400 | if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR)) |
ac27a0ec | 401 | return 0; |
617ba13b | 402 | error = ext4_get_inode_loc(inode, &iloc); |
ac27a0ec DK |
403 | if (error) |
404 | return error; | |
617ba13b | 405 | raw_inode = ext4_raw_inode(&iloc); |
ac27a0ec | 406 | header = IHDR(inode, raw_inode); |
617ba13b MC |
407 | end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; |
408 | error = ext4_xattr_check_names(IFIRST(header), end); | |
ac27a0ec DK |
409 | if (error) |
410 | goto cleanup; | |
431547b3 | 411 | error = ext4_xattr_list_entries(dentry, IFIRST(header), |
ac27a0ec DK |
412 | buffer, buffer_size); |
413 | ||
414 | cleanup: | |
415 | brelse(iloc.bh); | |
416 | return error; | |
417 | } | |
418 | ||
419 | /* | |
617ba13b | 420 | * ext4_xattr_list() |
ac27a0ec DK |
421 | * |
422 | * Copy a list of attribute names into the buffer | |
423 | * provided, or compute the buffer size required. | |
424 | * Buffer is NULL to compute the size of the buffer required. | |
425 | * | |
426 | * Returns a negative error number on failure, or the number of bytes | |
427 | * used / required on success. | |
428 | */ | |
d3a95d47 | 429 | static int |
431547b3 | 430 | ext4_xattr_list(struct dentry *dentry, char *buffer, size_t buffer_size) |
ac27a0ec DK |
431 | { |
432 | int i_error, b_error; | |
433 | ||
431547b3 CH |
434 | down_read(&EXT4_I(dentry->d_inode)->xattr_sem); |
435 | i_error = ext4_xattr_ibody_list(dentry, buffer, buffer_size); | |
ac27a0ec DK |
436 | if (i_error < 0) { |
437 | b_error = 0; | |
438 | } else { | |
439 | if (buffer) { | |
440 | buffer += i_error; | |
441 | buffer_size -= i_error; | |
442 | } | |
431547b3 | 443 | b_error = ext4_xattr_block_list(dentry, buffer, buffer_size); |
ac27a0ec DK |
444 | if (b_error < 0) |
445 | i_error = 0; | |
446 | } | |
431547b3 | 447 | up_read(&EXT4_I(dentry->d_inode)->xattr_sem); |
ac27a0ec DK |
448 | return i_error + b_error; |
449 | } | |
450 | ||
451 | /* | |
617ba13b | 452 | * If the EXT4_FEATURE_COMPAT_EXT_ATTR feature of this file system is |
ac27a0ec DK |
453 | * not set, set it. |
454 | */ | |
617ba13b | 455 | static void ext4_xattr_update_super_block(handle_t *handle, |
ac27a0ec DK |
456 | struct super_block *sb) |
457 | { | |
617ba13b | 458 | if (EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_EXT_ATTR)) |
ac27a0ec DK |
459 | return; |
460 | ||
617ba13b | 461 | if (ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh) == 0) { |
ed2908f3 | 462 | EXT4_SET_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_EXT_ATTR); |
ac27a0ec | 463 | sb->s_dirt = 1; |
0390131b | 464 | ext4_handle_dirty_metadata(handle, NULL, EXT4_SB(sb)->s_sbh); |
ac27a0ec | 465 | } |
ac27a0ec DK |
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 | |
617ba13b | 473 | ext4_xattr_release_block(handle_t *handle, struct inode *inode, |
ac27a0ec DK |
474 | struct buffer_head *bh) |
475 | { | |
476 | struct mb_cache_entry *ce = NULL; | |
8a2bfdcb | 477 | int error = 0; |
ac27a0ec | 478 | |
617ba13b | 479 | ce = mb_cache_entry_get(ext4_xattr_cache, bh->b_bdev, bh->b_blocknr); |
8a2bfdcb MC |
480 | error = ext4_journal_get_write_access(handle, bh); |
481 | if (error) | |
482 | goto out; | |
483 | ||
484 | lock_buffer(bh); | |
ac27a0ec DK |
485 | if (BHDR(bh)->h_refcount == cpu_to_le32(1)) { |
486 | ea_bdebug(bh, "refcount now=0; freeing"); | |
487 | if (ce) | |
488 | mb_cache_entry_free(ce); | |
ac27a0ec | 489 | get_bh(bh); |
e6362609 TT |
490 | ext4_free_blocks(handle, inode, bh, 0, 1, |
491 | EXT4_FREE_BLOCKS_METADATA | | |
492 | EXT4_FREE_BLOCKS_FORGET); | |
ac27a0ec | 493 | } else { |
e8546d06 | 494 | le32_add_cpu(&BHDR(bh)->h_refcount, -1); |
0390131b | 495 | error = ext4_handle_dirty_metadata(handle, inode, bh); |
8a2bfdcb | 496 | if (IS_SYNC(inode)) |
0390131b | 497 | ext4_handle_sync(handle); |
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)); | |
ac27a0ec DK |
501 | if (ce) |
502 | mb_cache_entry_release(ce); | |
503 | } | |
8a2bfdcb MC |
504 | unlock_buffer(bh); |
505 | out: | |
506 | ext4_std_error(inode->i_sb, error); | |
507 | return; | |
ac27a0ec DK |
508 | } |
509 | ||
6dd4ee7c KS |
510 | /* |
511 | * Find the available free space for EAs. This also returns the total number of | |
512 | * bytes used by EA entries. | |
513 | */ | |
514 | static size_t ext4_xattr_free_space(struct ext4_xattr_entry *last, | |
515 | size_t *min_offs, void *base, int *total) | |
516 | { | |
517 | for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) { | |
518 | *total += EXT4_XATTR_LEN(last->e_name_len); | |
519 | if (!last->e_value_block && last->e_value_size) { | |
520 | size_t offs = le16_to_cpu(last->e_value_offs); | |
521 | if (offs < *min_offs) | |
522 | *min_offs = offs; | |
523 | } | |
524 | } | |
525 | return (*min_offs - ((void *)last - base) - sizeof(__u32)); | |
526 | } | |
527 | ||
617ba13b | 528 | struct ext4_xattr_info { |
ac27a0ec DK |
529 | int name_index; |
530 | const char *name; | |
531 | const void *value; | |
532 | size_t value_len; | |
533 | }; | |
534 | ||
617ba13b MC |
535 | struct ext4_xattr_search { |
536 | struct ext4_xattr_entry *first; | |
ac27a0ec DK |
537 | void *base; |
538 | void *end; | |
617ba13b | 539 | struct ext4_xattr_entry *here; |
ac27a0ec DK |
540 | int not_found; |
541 | }; | |
542 | ||
543 | static int | |
617ba13b | 544 | ext4_xattr_set_entry(struct ext4_xattr_info *i, struct ext4_xattr_search *s) |
ac27a0ec | 545 | { |
617ba13b | 546 | struct ext4_xattr_entry *last; |
ac27a0ec DK |
547 | size_t free, min_offs = s->end - s->base, name_len = strlen(i->name); |
548 | ||
549 | /* Compute min_offs and last. */ | |
550 | last = s->first; | |
617ba13b | 551 | for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) { |
ac27a0ec DK |
552 | if (!last->e_value_block && last->e_value_size) { |
553 | size_t offs = le16_to_cpu(last->e_value_offs); | |
554 | if (offs < min_offs) | |
555 | min_offs = offs; | |
556 | } | |
557 | } | |
558 | free = min_offs - ((void *)last - s->base) - sizeof(__u32); | |
559 | if (!s->not_found) { | |
560 | if (!s->here->e_value_block && s->here->e_value_size) { | |
561 | size_t size = le32_to_cpu(s->here->e_value_size); | |
617ba13b | 562 | free += EXT4_XATTR_SIZE(size); |
ac27a0ec | 563 | } |
617ba13b | 564 | free += EXT4_XATTR_LEN(name_len); |
ac27a0ec DK |
565 | } |
566 | if (i->value) { | |
617ba13b MC |
567 | if (free < EXT4_XATTR_SIZE(i->value_len) || |
568 | free < EXT4_XATTR_LEN(name_len) + | |
569 | EXT4_XATTR_SIZE(i->value_len)) | |
ac27a0ec DK |
570 | return -ENOSPC; |
571 | } | |
572 | ||
573 | if (i->value && s->not_found) { | |
574 | /* Insert the new name. */ | |
617ba13b | 575 | size_t size = EXT4_XATTR_LEN(name_len); |
ac27a0ec DK |
576 | size_t rest = (void *)last - (void *)s->here + sizeof(__u32); |
577 | memmove((void *)s->here + size, s->here, rest); | |
578 | memset(s->here, 0, size); | |
579 | s->here->e_name_index = i->name_index; | |
580 | s->here->e_name_len = name_len; | |
581 | memcpy(s->here->e_name, i->name, name_len); | |
582 | } else { | |
583 | if (!s->here->e_value_block && s->here->e_value_size) { | |
584 | void *first_val = s->base + min_offs; | |
585 | size_t offs = le16_to_cpu(s->here->e_value_offs); | |
586 | void *val = s->base + offs; | |
617ba13b | 587 | size_t size = EXT4_XATTR_SIZE( |
ac27a0ec DK |
588 | le32_to_cpu(s->here->e_value_size)); |
589 | ||
617ba13b | 590 | if (i->value && size == EXT4_XATTR_SIZE(i->value_len)) { |
ac27a0ec DK |
591 | /* The old and the new value have the same |
592 | size. Just replace. */ | |
593 | s->here->e_value_size = | |
594 | cpu_to_le32(i->value_len); | |
617ba13b MC |
595 | memset(val + size - EXT4_XATTR_PAD, 0, |
596 | EXT4_XATTR_PAD); /* Clear pad bytes. */ | |
ac27a0ec DK |
597 | memcpy(val, i->value, i->value_len); |
598 | return 0; | |
599 | } | |
600 | ||
601 | /* Remove the old value. */ | |
602 | memmove(first_val + size, first_val, val - first_val); | |
603 | memset(first_val, 0, size); | |
604 | s->here->e_value_size = 0; | |
605 | s->here->e_value_offs = 0; | |
606 | min_offs += size; | |
607 | ||
608 | /* Adjust all value offsets. */ | |
609 | last = s->first; | |
610 | while (!IS_LAST_ENTRY(last)) { | |
611 | size_t o = le16_to_cpu(last->e_value_offs); | |
612 | if (!last->e_value_block && | |
613 | last->e_value_size && o < offs) | |
614 | last->e_value_offs = | |
615 | cpu_to_le16(o + size); | |
617ba13b | 616 | last = EXT4_XATTR_NEXT(last); |
ac27a0ec DK |
617 | } |
618 | } | |
619 | if (!i->value) { | |
620 | /* Remove the old name. */ | |
617ba13b | 621 | size_t size = EXT4_XATTR_LEN(name_len); |
ac27a0ec DK |
622 | last = ENTRY((void *)last - size); |
623 | memmove(s->here, (void *)s->here + size, | |
624 | (void *)last - (void *)s->here + sizeof(__u32)); | |
625 | memset(last, 0, size); | |
626 | } | |
627 | } | |
628 | ||
629 | if (i->value) { | |
630 | /* Insert the new value. */ | |
631 | s->here->e_value_size = cpu_to_le32(i->value_len); | |
632 | if (i->value_len) { | |
617ba13b | 633 | size_t size = EXT4_XATTR_SIZE(i->value_len); |
ac27a0ec DK |
634 | void *val = s->base + min_offs - size; |
635 | s->here->e_value_offs = cpu_to_le16(min_offs - size); | |
617ba13b MC |
636 | memset(val + size - EXT4_XATTR_PAD, 0, |
637 | EXT4_XATTR_PAD); /* Clear the pad bytes. */ | |
ac27a0ec DK |
638 | memcpy(val, i->value, i->value_len); |
639 | } | |
640 | } | |
641 | return 0; | |
642 | } | |
643 | ||
617ba13b MC |
644 | struct ext4_xattr_block_find { |
645 | struct ext4_xattr_search s; | |
ac27a0ec DK |
646 | struct buffer_head *bh; |
647 | }; | |
648 | ||
649 | static int | |
617ba13b MC |
650 | ext4_xattr_block_find(struct inode *inode, struct ext4_xattr_info *i, |
651 | struct ext4_xattr_block_find *bs) | |
ac27a0ec DK |
652 | { |
653 | struct super_block *sb = inode->i_sb; | |
654 | int error; | |
655 | ||
656 | ea_idebug(inode, "name=%d.%s, value=%p, value_len=%ld", | |
657 | i->name_index, i->name, i->value, (long)i->value_len); | |
658 | ||
617ba13b | 659 | if (EXT4_I(inode)->i_file_acl) { |
ac27a0ec | 660 | /* The inode already has an extended attribute block. */ |
617ba13b | 661 | bs->bh = sb_bread(sb, EXT4_I(inode)->i_file_acl); |
ac27a0ec DK |
662 | error = -EIO; |
663 | if (!bs->bh) | |
664 | goto cleanup; | |
665 | ea_bdebug(bs->bh, "b_count=%d, refcount=%d", | |
666 | atomic_read(&(bs->bh->b_count)), | |
667 | le32_to_cpu(BHDR(bs->bh)->h_refcount)); | |
617ba13b | 668 | if (ext4_xattr_check_block(bs->bh)) { |
12062ddd ES |
669 | ext4_error(sb, "inode %lu: bad block %llu", |
670 | inode->i_ino, EXT4_I(inode)->i_file_acl); | |
ac27a0ec DK |
671 | error = -EIO; |
672 | goto cleanup; | |
673 | } | |
674 | /* Find the named attribute. */ | |
675 | bs->s.base = BHDR(bs->bh); | |
676 | bs->s.first = BFIRST(bs->bh); | |
677 | bs->s.end = bs->bh->b_data + bs->bh->b_size; | |
678 | bs->s.here = bs->s.first; | |
617ba13b | 679 | error = ext4_xattr_find_entry(&bs->s.here, i->name_index, |
ac27a0ec DK |
680 | i->name, bs->bh->b_size, 1); |
681 | if (error && error != -ENODATA) | |
682 | goto cleanup; | |
683 | bs->s.not_found = error; | |
684 | } | |
685 | error = 0; | |
686 | ||
687 | cleanup: | |
688 | return error; | |
689 | } | |
690 | ||
691 | static int | |
617ba13b MC |
692 | ext4_xattr_block_set(handle_t *handle, struct inode *inode, |
693 | struct ext4_xattr_info *i, | |
694 | struct ext4_xattr_block_find *bs) | |
ac27a0ec DK |
695 | { |
696 | struct super_block *sb = inode->i_sb; | |
697 | struct buffer_head *new_bh = NULL; | |
617ba13b | 698 | struct ext4_xattr_search *s = &bs->s; |
ac27a0ec | 699 | struct mb_cache_entry *ce = NULL; |
8a2bfdcb | 700 | int error = 0; |
ac27a0ec | 701 | |
617ba13b | 702 | #define header(x) ((struct ext4_xattr_header *)(x)) |
ac27a0ec DK |
703 | |
704 | if (i->value && i->value_len > sb->s_blocksize) | |
705 | return -ENOSPC; | |
706 | if (s->base) { | |
617ba13b | 707 | ce = mb_cache_entry_get(ext4_xattr_cache, bs->bh->b_bdev, |
ac27a0ec | 708 | bs->bh->b_blocknr); |
8a2bfdcb MC |
709 | error = ext4_journal_get_write_access(handle, bs->bh); |
710 | if (error) | |
711 | goto cleanup; | |
712 | lock_buffer(bs->bh); | |
713 | ||
ac27a0ec DK |
714 | if (header(s->base)->h_refcount == cpu_to_le32(1)) { |
715 | if (ce) { | |
716 | mb_cache_entry_free(ce); | |
717 | ce = NULL; | |
718 | } | |
719 | ea_bdebug(bs->bh, "modifying in-place"); | |
617ba13b | 720 | error = ext4_xattr_set_entry(i, s); |
ac27a0ec DK |
721 | if (!error) { |
722 | if (!IS_LAST_ENTRY(s->first)) | |
617ba13b | 723 | ext4_xattr_rehash(header(s->base), |
ac27a0ec | 724 | s->here); |
617ba13b | 725 | ext4_xattr_cache_insert(bs->bh); |
ac27a0ec DK |
726 | } |
727 | unlock_buffer(bs->bh); | |
728 | if (error == -EIO) | |
729 | goto bad_block; | |
730 | if (!error) | |
0390131b FM |
731 | error = ext4_handle_dirty_metadata(handle, |
732 | inode, | |
733 | bs->bh); | |
ac27a0ec DK |
734 | if (error) |
735 | goto cleanup; | |
736 | goto inserted; | |
737 | } else { | |
738 | int offset = (char *)s->here - bs->bh->b_data; | |
739 | ||
8a2bfdcb MC |
740 | unlock_buffer(bs->bh); |
741 | jbd2_journal_release_buffer(handle, bs->bh); | |
ac27a0ec DK |
742 | if (ce) { |
743 | mb_cache_entry_release(ce); | |
744 | ce = NULL; | |
745 | } | |
746 | ea_bdebug(bs->bh, "cloning"); | |
216553c4 | 747 | s->base = kmalloc(bs->bh->b_size, GFP_NOFS); |
ac27a0ec DK |
748 | error = -ENOMEM; |
749 | if (s->base == NULL) | |
750 | goto cleanup; | |
751 | memcpy(s->base, BHDR(bs->bh), bs->bh->b_size); | |
752 | s->first = ENTRY(header(s->base)+1); | |
753 | header(s->base)->h_refcount = cpu_to_le32(1); | |
754 | s->here = ENTRY(s->base + offset); | |
755 | s->end = s->base + bs->bh->b_size; | |
756 | } | |
757 | } else { | |
758 | /* Allocate a buffer where we construct the new block. */ | |
216553c4 | 759 | s->base = kzalloc(sb->s_blocksize, GFP_NOFS); |
ac27a0ec DK |
760 | /* assert(header == s->base) */ |
761 | error = -ENOMEM; | |
762 | if (s->base == NULL) | |
763 | goto cleanup; | |
617ba13b | 764 | header(s->base)->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC); |
ac27a0ec DK |
765 | header(s->base)->h_blocks = cpu_to_le32(1); |
766 | header(s->base)->h_refcount = cpu_to_le32(1); | |
767 | s->first = ENTRY(header(s->base)+1); | |
768 | s->here = ENTRY(header(s->base)+1); | |
769 | s->end = s->base + sb->s_blocksize; | |
770 | } | |
771 | ||
617ba13b | 772 | error = ext4_xattr_set_entry(i, s); |
ac27a0ec DK |
773 | if (error == -EIO) |
774 | goto bad_block; | |
775 | if (error) | |
776 | goto cleanup; | |
777 | if (!IS_LAST_ENTRY(s->first)) | |
617ba13b | 778 | ext4_xattr_rehash(header(s->base), s->here); |
ac27a0ec DK |
779 | |
780 | inserted: | |
781 | if (!IS_LAST_ENTRY(s->first)) { | |
617ba13b | 782 | new_bh = ext4_xattr_cache_find(inode, header(s->base), &ce); |
ac27a0ec DK |
783 | if (new_bh) { |
784 | /* We found an identical block in the cache. */ | |
785 | if (new_bh == bs->bh) | |
786 | ea_bdebug(new_bh, "keeping"); | |
787 | else { | |
788 | /* The old block is released after updating | |
789 | the inode. */ | |
5dd4056d CH |
790 | error = dquot_alloc_block(inode, 1); |
791 | if (error) | |
ac27a0ec | 792 | goto cleanup; |
617ba13b | 793 | error = ext4_journal_get_write_access(handle, |
ac27a0ec DK |
794 | new_bh); |
795 | if (error) | |
796 | goto cleanup_dquot; | |
797 | lock_buffer(new_bh); | |
e8546d06 | 798 | le32_add_cpu(&BHDR(new_bh)->h_refcount, 1); |
ac27a0ec DK |
799 | ea_bdebug(new_bh, "reusing; refcount now=%d", |
800 | le32_to_cpu(BHDR(new_bh)->h_refcount)); | |
801 | unlock_buffer(new_bh); | |
0390131b FM |
802 | error = ext4_handle_dirty_metadata(handle, |
803 | inode, | |
804 | new_bh); | |
ac27a0ec DK |
805 | if (error) |
806 | goto cleanup_dquot; | |
807 | } | |
808 | mb_cache_entry_release(ce); | |
809 | ce = NULL; | |
810 | } else if (bs->bh && s->base == bs->bh->b_data) { | |
811 | /* We were modifying this block in-place. */ | |
812 | ea_bdebug(bs->bh, "keeping this block"); | |
813 | new_bh = bs->bh; | |
814 | get_bh(new_bh); | |
815 | } else { | |
816 | /* We need to allocate a new block */ | |
fb0a387d ES |
817 | ext4_fsblk_t goal, block; |
818 | ||
819 | goal = ext4_group_first_block_no(sb, | |
d00a6d7b | 820 | EXT4_I(inode)->i_block_group); |
fb0a387d ES |
821 | |
822 | /* non-extent files can't have physical blocks past 2^32 */ | |
823 | if (!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL)) | |
824 | goal = goal & EXT4_MAX_BLOCK_FILE_PHYS; | |
825 | ||
826 | block = ext4_new_meta_blocks(handle, inode, | |
97df5d15 | 827 | goal, NULL, &error); |
ac27a0ec DK |
828 | if (error) |
829 | goto cleanup; | |
fb0a387d ES |
830 | |
831 | if (!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL)) | |
832 | BUG_ON(block > EXT4_MAX_BLOCK_FILE_PHYS); | |
833 | ||
ac27a0ec DK |
834 | ea_idebug(inode, "creating block %d", block); |
835 | ||
836 | new_bh = sb_getblk(sb, block); | |
837 | if (!new_bh) { | |
838 | getblk_failed: | |
e6362609 TT |
839 | ext4_free_blocks(handle, inode, 0, block, 1, |
840 | EXT4_FREE_BLOCKS_METADATA); | |
ac27a0ec DK |
841 | error = -EIO; |
842 | goto cleanup; | |
843 | } | |
844 | lock_buffer(new_bh); | |
617ba13b | 845 | error = ext4_journal_get_create_access(handle, new_bh); |
ac27a0ec DK |
846 | if (error) { |
847 | unlock_buffer(new_bh); | |
848 | goto getblk_failed; | |
849 | } | |
850 | memcpy(new_bh->b_data, s->base, new_bh->b_size); | |
851 | set_buffer_uptodate(new_bh); | |
852 | unlock_buffer(new_bh); | |
617ba13b | 853 | ext4_xattr_cache_insert(new_bh); |
0390131b FM |
854 | error = ext4_handle_dirty_metadata(handle, |
855 | inode, new_bh); | |
ac27a0ec DK |
856 | if (error) |
857 | goto cleanup; | |
858 | } | |
859 | } | |
860 | ||
861 | /* Update the inode. */ | |
617ba13b | 862 | EXT4_I(inode)->i_file_acl = new_bh ? new_bh->b_blocknr : 0; |
ac27a0ec DK |
863 | |
864 | /* Drop the previous xattr block. */ | |
865 | if (bs->bh && bs->bh != new_bh) | |
617ba13b | 866 | ext4_xattr_release_block(handle, inode, bs->bh); |
ac27a0ec DK |
867 | error = 0; |
868 | ||
869 | cleanup: | |
870 | if (ce) | |
871 | mb_cache_entry_release(ce); | |
872 | brelse(new_bh); | |
873 | if (!(bs->bh && s->base == bs->bh->b_data)) | |
874 | kfree(s->base); | |
875 | ||
876 | return error; | |
877 | ||
878 | cleanup_dquot: | |
5dd4056d | 879 | dquot_free_block(inode, 1); |
ac27a0ec DK |
880 | goto cleanup; |
881 | ||
882 | bad_block: | |
12062ddd ES |
883 | ext4_error(inode->i_sb, "inode %lu: bad block %llu", |
884 | inode->i_ino, EXT4_I(inode)->i_file_acl); | |
ac27a0ec DK |
885 | goto cleanup; |
886 | ||
887 | #undef header | |
888 | } | |
889 | ||
617ba13b MC |
890 | struct ext4_xattr_ibody_find { |
891 | struct ext4_xattr_search s; | |
892 | struct ext4_iloc iloc; | |
ac27a0ec DK |
893 | }; |
894 | ||
895 | static int | |
617ba13b MC |
896 | ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i, |
897 | struct ext4_xattr_ibody_find *is) | |
ac27a0ec | 898 | { |
617ba13b MC |
899 | struct ext4_xattr_ibody_header *header; |
900 | struct ext4_inode *raw_inode; | |
ac27a0ec DK |
901 | int error; |
902 | ||
617ba13b | 903 | if (EXT4_I(inode)->i_extra_isize == 0) |
ac27a0ec | 904 | return 0; |
617ba13b | 905 | raw_inode = ext4_raw_inode(&is->iloc); |
ac27a0ec DK |
906 | header = IHDR(inode, raw_inode); |
907 | is->s.base = is->s.first = IFIRST(header); | |
908 | is->s.here = is->s.first; | |
617ba13b | 909 | is->s.end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; |
19f5fb7a | 910 | if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) { |
617ba13b | 911 | error = ext4_xattr_check_names(IFIRST(header), is->s.end); |
ac27a0ec DK |
912 | if (error) |
913 | return error; | |
914 | /* Find the named attribute. */ | |
617ba13b | 915 | error = ext4_xattr_find_entry(&is->s.here, i->name_index, |
ac27a0ec DK |
916 | i->name, is->s.end - |
917 | (void *)is->s.base, 0); | |
918 | if (error && error != -ENODATA) | |
919 | return error; | |
920 | is->s.not_found = error; | |
921 | } | |
922 | return 0; | |
923 | } | |
924 | ||
925 | static int | |
617ba13b MC |
926 | ext4_xattr_ibody_set(handle_t *handle, struct inode *inode, |
927 | struct ext4_xattr_info *i, | |
928 | struct ext4_xattr_ibody_find *is) | |
ac27a0ec | 929 | { |
617ba13b MC |
930 | struct ext4_xattr_ibody_header *header; |
931 | struct ext4_xattr_search *s = &is->s; | |
ac27a0ec DK |
932 | int error; |
933 | ||
617ba13b | 934 | if (EXT4_I(inode)->i_extra_isize == 0) |
ac27a0ec | 935 | return -ENOSPC; |
617ba13b | 936 | error = ext4_xattr_set_entry(i, s); |
ac27a0ec DK |
937 | if (error) |
938 | return error; | |
617ba13b | 939 | header = IHDR(inode, ext4_raw_inode(&is->iloc)); |
ac27a0ec | 940 | if (!IS_LAST_ENTRY(s->first)) { |
617ba13b | 941 | header->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC); |
19f5fb7a | 942 | ext4_set_inode_state(inode, EXT4_STATE_XATTR); |
ac27a0ec DK |
943 | } else { |
944 | header->h_magic = cpu_to_le32(0); | |
19f5fb7a | 945 | ext4_clear_inode_state(inode, EXT4_STATE_XATTR); |
ac27a0ec DK |
946 | } |
947 | return 0; | |
948 | } | |
949 | ||
950 | /* | |
617ba13b | 951 | * ext4_xattr_set_handle() |
ac27a0ec DK |
952 | * |
953 | * Create, replace or remove an extended attribute for this inode. Buffer | |
954 | * is NULL to remove an existing extended attribute, and non-NULL to | |
955 | * either replace an existing extended attribute, or create a new extended | |
956 | * attribute. The flags XATTR_REPLACE and XATTR_CREATE | |
957 | * specify that an extended attribute must exist and must not exist | |
958 | * previous to the call, respectively. | |
959 | * | |
960 | * Returns 0, or a negative error number on failure. | |
961 | */ | |
962 | int | |
617ba13b | 963 | ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index, |
ac27a0ec DK |
964 | const char *name, const void *value, size_t value_len, |
965 | int flags) | |
966 | { | |
617ba13b | 967 | struct ext4_xattr_info i = { |
ac27a0ec DK |
968 | .name_index = name_index, |
969 | .name = name, | |
970 | .value = value, | |
971 | .value_len = value_len, | |
972 | ||
973 | }; | |
617ba13b | 974 | struct ext4_xattr_ibody_find is = { |
ac27a0ec DK |
975 | .s = { .not_found = -ENODATA, }, |
976 | }; | |
617ba13b | 977 | struct ext4_xattr_block_find bs = { |
ac27a0ec DK |
978 | .s = { .not_found = -ENODATA, }, |
979 | }; | |
4d20c685 | 980 | unsigned long no_expand; |
ac27a0ec DK |
981 | int error; |
982 | ||
983 | if (!name) | |
984 | return -EINVAL; | |
985 | if (strlen(name) > 255) | |
986 | return -ERANGE; | |
617ba13b | 987 | down_write(&EXT4_I(inode)->xattr_sem); |
19f5fb7a TT |
988 | no_expand = ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND); |
989 | ext4_set_inode_state(inode, EXT4_STATE_NO_EXPAND); | |
4d20c685 | 990 | |
617ba13b | 991 | error = ext4_get_inode_loc(inode, &is.iloc); |
ac27a0ec DK |
992 | if (error) |
993 | goto cleanup; | |
994 | ||
86ebfd08 ES |
995 | error = ext4_journal_get_write_access(handle, is.iloc.bh); |
996 | if (error) | |
997 | goto cleanup; | |
998 | ||
19f5fb7a | 999 | if (ext4_test_inode_state(inode, EXT4_STATE_NEW)) { |
617ba13b MC |
1000 | struct ext4_inode *raw_inode = ext4_raw_inode(&is.iloc); |
1001 | memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size); | |
19f5fb7a | 1002 | ext4_clear_inode_state(inode, EXT4_STATE_NEW); |
ac27a0ec DK |
1003 | } |
1004 | ||
617ba13b | 1005 | error = ext4_xattr_ibody_find(inode, &i, &is); |
ac27a0ec DK |
1006 | if (error) |
1007 | goto cleanup; | |
1008 | if (is.s.not_found) | |
617ba13b | 1009 | error = ext4_xattr_block_find(inode, &i, &bs); |
ac27a0ec DK |
1010 | if (error) |
1011 | goto cleanup; | |
1012 | if (is.s.not_found && bs.s.not_found) { | |
1013 | error = -ENODATA; | |
1014 | if (flags & XATTR_REPLACE) | |
1015 | goto cleanup; | |
1016 | error = 0; | |
1017 | if (!value) | |
1018 | goto cleanup; | |
1019 | } else { | |
1020 | error = -EEXIST; | |
1021 | if (flags & XATTR_CREATE) | |
1022 | goto cleanup; | |
1023 | } | |
ac27a0ec DK |
1024 | if (!value) { |
1025 | if (!is.s.not_found) | |
617ba13b | 1026 | error = ext4_xattr_ibody_set(handle, inode, &i, &is); |
ac27a0ec | 1027 | else if (!bs.s.not_found) |
617ba13b | 1028 | error = ext4_xattr_block_set(handle, inode, &i, &bs); |
ac27a0ec | 1029 | } else { |
617ba13b | 1030 | error = ext4_xattr_ibody_set(handle, inode, &i, &is); |
ac27a0ec DK |
1031 | if (!error && !bs.s.not_found) { |
1032 | i.value = NULL; | |
617ba13b | 1033 | error = ext4_xattr_block_set(handle, inode, &i, &bs); |
ac27a0ec | 1034 | } else if (error == -ENOSPC) { |
7e01c8e5 TY |
1035 | if (EXT4_I(inode)->i_file_acl && !bs.s.base) { |
1036 | error = ext4_xattr_block_find(inode, &i, &bs); | |
1037 | if (error) | |
1038 | goto cleanup; | |
1039 | } | |
617ba13b | 1040 | error = ext4_xattr_block_set(handle, inode, &i, &bs); |
ac27a0ec DK |
1041 | if (error) |
1042 | goto cleanup; | |
1043 | if (!is.s.not_found) { | |
1044 | i.value = NULL; | |
617ba13b | 1045 | error = ext4_xattr_ibody_set(handle, inode, &i, |
ac27a0ec DK |
1046 | &is); |
1047 | } | |
1048 | } | |
1049 | } | |
1050 | if (!error) { | |
617ba13b | 1051 | ext4_xattr_update_super_block(handle, inode->i_sb); |
ef7f3835 | 1052 | inode->i_ctime = ext4_current_time(inode); |
6dd4ee7c | 1053 | if (!value) |
19f5fb7a | 1054 | ext4_clear_inode_state(inode, EXT4_STATE_NO_EXPAND); |
617ba13b | 1055 | error = ext4_mark_iloc_dirty(handle, inode, &is.iloc); |
ac27a0ec | 1056 | /* |
617ba13b | 1057 | * The bh is consumed by ext4_mark_iloc_dirty, even with |
ac27a0ec DK |
1058 | * error != 0. |
1059 | */ | |
1060 | is.iloc.bh = NULL; | |
1061 | if (IS_SYNC(inode)) | |
0390131b | 1062 | ext4_handle_sync(handle); |
ac27a0ec DK |
1063 | } |
1064 | ||
1065 | cleanup: | |
1066 | brelse(is.iloc.bh); | |
1067 | brelse(bs.bh); | |
4d20c685 | 1068 | if (no_expand == 0) |
19f5fb7a | 1069 | ext4_clear_inode_state(inode, EXT4_STATE_NO_EXPAND); |
617ba13b | 1070 | up_write(&EXT4_I(inode)->xattr_sem); |
ac27a0ec DK |
1071 | return error; |
1072 | } | |
1073 | ||
1074 | /* | |
617ba13b | 1075 | * ext4_xattr_set() |
ac27a0ec | 1076 | * |
617ba13b | 1077 | * Like ext4_xattr_set_handle, but start from an inode. This extended |
ac27a0ec DK |
1078 | * attribute modification is a filesystem transaction by itself. |
1079 | * | |
1080 | * Returns 0, or a negative error number on failure. | |
1081 | */ | |
1082 | int | |
617ba13b | 1083 | ext4_xattr_set(struct inode *inode, int name_index, const char *name, |
ac27a0ec DK |
1084 | const void *value, size_t value_len, int flags) |
1085 | { | |
1086 | handle_t *handle; | |
1087 | int error, retries = 0; | |
1088 | ||
1089 | retry: | |
617ba13b | 1090 | handle = ext4_journal_start(inode, EXT4_DATA_TRANS_BLOCKS(inode->i_sb)); |
ac27a0ec DK |
1091 | if (IS_ERR(handle)) { |
1092 | error = PTR_ERR(handle); | |
1093 | } else { | |
1094 | int error2; | |
1095 | ||
617ba13b | 1096 | error = ext4_xattr_set_handle(handle, inode, name_index, name, |
ac27a0ec | 1097 | value, value_len, flags); |
617ba13b | 1098 | error2 = ext4_journal_stop(handle); |
ac27a0ec | 1099 | if (error == -ENOSPC && |
617ba13b | 1100 | ext4_should_retry_alloc(inode->i_sb, &retries)) |
ac27a0ec DK |
1101 | goto retry; |
1102 | if (error == 0) | |
1103 | error = error2; | |
1104 | } | |
1105 | ||
1106 | return error; | |
1107 | } | |
1108 | ||
6dd4ee7c KS |
1109 | /* |
1110 | * Shift the EA entries in the inode to create space for the increased | |
1111 | * i_extra_isize. | |
1112 | */ | |
1113 | static void ext4_xattr_shift_entries(struct ext4_xattr_entry *entry, | |
1114 | int value_offs_shift, void *to, | |
1115 | void *from, size_t n, int blocksize) | |
1116 | { | |
1117 | struct ext4_xattr_entry *last = entry; | |
1118 | int new_offs; | |
1119 | ||
1120 | /* Adjust the value offsets of the entries */ | |
1121 | for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) { | |
1122 | if (!last->e_value_block && last->e_value_size) { | |
1123 | new_offs = le16_to_cpu(last->e_value_offs) + | |
1124 | value_offs_shift; | |
1125 | BUG_ON(new_offs + le32_to_cpu(last->e_value_size) | |
1126 | > blocksize); | |
1127 | last->e_value_offs = cpu_to_le16(new_offs); | |
1128 | } | |
1129 | } | |
1130 | /* Shift the entries by n bytes */ | |
1131 | memmove(to, from, n); | |
1132 | } | |
1133 | ||
1134 | /* | |
1135 | * Expand an inode by new_extra_isize bytes when EAs are present. | |
1136 | * Returns 0 on success or negative error number on failure. | |
1137 | */ | |
1138 | int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize, | |
1139 | struct ext4_inode *raw_inode, handle_t *handle) | |
1140 | { | |
1141 | struct ext4_xattr_ibody_header *header; | |
1142 | struct ext4_xattr_entry *entry, *last, *first; | |
1143 | struct buffer_head *bh = NULL; | |
1144 | struct ext4_xattr_ibody_find *is = NULL; | |
1145 | struct ext4_xattr_block_find *bs = NULL; | |
1146 | char *buffer = NULL, *b_entry_name = NULL; | |
1147 | size_t min_offs, free; | |
1148 | int total_ino, total_blk; | |
1149 | void *base, *start, *end; | |
1150 | int extra_isize = 0, error = 0, tried_min_extra_isize = 0; | |
ac39849d | 1151 | int s_min_extra_isize = le16_to_cpu(EXT4_SB(inode->i_sb)->s_es->s_min_extra_isize); |
6dd4ee7c KS |
1152 | |
1153 | down_write(&EXT4_I(inode)->xattr_sem); | |
1154 | retry: | |
1155 | if (EXT4_I(inode)->i_extra_isize >= new_extra_isize) { | |
1156 | up_write(&EXT4_I(inode)->xattr_sem); | |
1157 | return 0; | |
1158 | } | |
1159 | ||
1160 | header = IHDR(inode, raw_inode); | |
1161 | entry = IFIRST(header); | |
1162 | ||
1163 | /* | |
1164 | * Check if enough free space is available in the inode to shift the | |
1165 | * entries ahead by new_extra_isize. | |
1166 | */ | |
1167 | ||
1168 | base = start = entry; | |
1169 | end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; | |
1170 | min_offs = end - base; | |
1171 | last = entry; | |
1172 | total_ino = sizeof(struct ext4_xattr_ibody_header); | |
1173 | ||
1174 | free = ext4_xattr_free_space(last, &min_offs, base, &total_ino); | |
1175 | if (free >= new_extra_isize) { | |
1176 | entry = IFIRST(header); | |
1177 | ext4_xattr_shift_entries(entry, EXT4_I(inode)->i_extra_isize | |
1178 | - new_extra_isize, (void *)raw_inode + | |
1179 | EXT4_GOOD_OLD_INODE_SIZE + new_extra_isize, | |
1180 | (void *)header, total_ino, | |
1181 | inode->i_sb->s_blocksize); | |
1182 | EXT4_I(inode)->i_extra_isize = new_extra_isize; | |
1183 | error = 0; | |
1184 | goto cleanup; | |
1185 | } | |
1186 | ||
1187 | /* | |
1188 | * Enough free space isn't available in the inode, check if | |
1189 | * EA block can hold new_extra_isize bytes. | |
1190 | */ | |
1191 | if (EXT4_I(inode)->i_file_acl) { | |
1192 | bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl); | |
1193 | error = -EIO; | |
1194 | if (!bh) | |
1195 | goto cleanup; | |
1196 | if (ext4_xattr_check_block(bh)) { | |
12062ddd ES |
1197 | ext4_error(inode->i_sb, "inode %lu: bad block %llu", |
1198 | inode->i_ino, EXT4_I(inode)->i_file_acl); | |
6dd4ee7c KS |
1199 | error = -EIO; |
1200 | goto cleanup; | |
1201 | } | |
1202 | base = BHDR(bh); | |
1203 | first = BFIRST(bh); | |
1204 | end = bh->b_data + bh->b_size; | |
1205 | min_offs = end - base; | |
1206 | free = ext4_xattr_free_space(first, &min_offs, base, | |
1207 | &total_blk); | |
1208 | if (free < new_extra_isize) { | |
1209 | if (!tried_min_extra_isize && s_min_extra_isize) { | |
1210 | tried_min_extra_isize++; | |
1211 | new_extra_isize = s_min_extra_isize; | |
1212 | brelse(bh); | |
1213 | goto retry; | |
1214 | } | |
1215 | error = -1; | |
1216 | goto cleanup; | |
1217 | } | |
1218 | } else { | |
1219 | free = inode->i_sb->s_blocksize; | |
1220 | } | |
1221 | ||
1222 | while (new_extra_isize > 0) { | |
1223 | size_t offs, size, entry_size; | |
1224 | struct ext4_xattr_entry *small_entry = NULL; | |
1225 | struct ext4_xattr_info i = { | |
1226 | .value = NULL, | |
1227 | .value_len = 0, | |
1228 | }; | |
1229 | unsigned int total_size; /* EA entry size + value size */ | |
1230 | unsigned int shift_bytes; /* No. of bytes to shift EAs by? */ | |
1231 | unsigned int min_total_size = ~0U; | |
1232 | ||
1233 | is = kzalloc(sizeof(struct ext4_xattr_ibody_find), GFP_NOFS); | |
1234 | bs = kzalloc(sizeof(struct ext4_xattr_block_find), GFP_NOFS); | |
1235 | if (!is || !bs) { | |
1236 | error = -ENOMEM; | |
1237 | goto cleanup; | |
1238 | } | |
1239 | ||
1240 | is->s.not_found = -ENODATA; | |
1241 | bs->s.not_found = -ENODATA; | |
1242 | is->iloc.bh = NULL; | |
1243 | bs->bh = NULL; | |
1244 | ||
1245 | last = IFIRST(header); | |
1246 | /* Find the entry best suited to be pushed into EA block */ | |
1247 | entry = NULL; | |
1248 | for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) { | |
1249 | total_size = | |
1250 | EXT4_XATTR_SIZE(le32_to_cpu(last->e_value_size)) + | |
1251 | EXT4_XATTR_LEN(last->e_name_len); | |
1252 | if (total_size <= free && total_size < min_total_size) { | |
1253 | if (total_size < new_extra_isize) { | |
1254 | small_entry = last; | |
1255 | } else { | |
1256 | entry = last; | |
1257 | min_total_size = total_size; | |
1258 | } | |
1259 | } | |
1260 | } | |
1261 | ||
1262 | if (entry == NULL) { | |
1263 | if (small_entry) { | |
1264 | entry = small_entry; | |
1265 | } else { | |
1266 | if (!tried_min_extra_isize && | |
1267 | s_min_extra_isize) { | |
1268 | tried_min_extra_isize++; | |
1269 | new_extra_isize = s_min_extra_isize; | |
1270 | goto retry; | |
1271 | } | |
1272 | error = -1; | |
1273 | goto cleanup; | |
1274 | } | |
1275 | } | |
1276 | offs = le16_to_cpu(entry->e_value_offs); | |
1277 | size = le32_to_cpu(entry->e_value_size); | |
1278 | entry_size = EXT4_XATTR_LEN(entry->e_name_len); | |
1279 | i.name_index = entry->e_name_index, | |
1280 | buffer = kmalloc(EXT4_XATTR_SIZE(size), GFP_NOFS); | |
1281 | b_entry_name = kmalloc(entry->e_name_len + 1, GFP_NOFS); | |
1282 | if (!buffer || !b_entry_name) { | |
1283 | error = -ENOMEM; | |
1284 | goto cleanup; | |
1285 | } | |
1286 | /* Save the entry name and the entry value */ | |
1287 | memcpy(buffer, (void *)IFIRST(header) + offs, | |
1288 | EXT4_XATTR_SIZE(size)); | |
1289 | memcpy(b_entry_name, entry->e_name, entry->e_name_len); | |
1290 | b_entry_name[entry->e_name_len] = '\0'; | |
1291 | i.name = b_entry_name; | |
1292 | ||
1293 | error = ext4_get_inode_loc(inode, &is->iloc); | |
1294 | if (error) | |
1295 | goto cleanup; | |
1296 | ||
1297 | error = ext4_xattr_ibody_find(inode, &i, is); | |
1298 | if (error) | |
1299 | goto cleanup; | |
1300 | ||
1301 | /* Remove the chosen entry from the inode */ | |
1302 | error = ext4_xattr_ibody_set(handle, inode, &i, is); | |
9aaab058 RK |
1303 | if (error) |
1304 | goto cleanup; | |
6dd4ee7c KS |
1305 | |
1306 | entry = IFIRST(header); | |
1307 | if (entry_size + EXT4_XATTR_SIZE(size) >= new_extra_isize) | |
1308 | shift_bytes = new_extra_isize; | |
1309 | else | |
1310 | shift_bytes = entry_size + size; | |
1311 | /* Adjust the offsets and shift the remaining entries ahead */ | |
1312 | ext4_xattr_shift_entries(entry, EXT4_I(inode)->i_extra_isize - | |
1313 | shift_bytes, (void *)raw_inode + | |
1314 | EXT4_GOOD_OLD_INODE_SIZE + extra_isize + shift_bytes, | |
1315 | (void *)header, total_ino - entry_size, | |
1316 | inode->i_sb->s_blocksize); | |
1317 | ||
1318 | extra_isize += shift_bytes; | |
1319 | new_extra_isize -= shift_bytes; | |
1320 | EXT4_I(inode)->i_extra_isize = extra_isize; | |
1321 | ||
1322 | i.name = b_entry_name; | |
1323 | i.value = buffer; | |
ac39849d | 1324 | i.value_len = size; |
6dd4ee7c KS |
1325 | error = ext4_xattr_block_find(inode, &i, bs); |
1326 | if (error) | |
1327 | goto cleanup; | |
1328 | ||
1329 | /* Add entry which was removed from the inode into the block */ | |
1330 | error = ext4_xattr_block_set(handle, inode, &i, bs); | |
1331 | if (error) | |
1332 | goto cleanup; | |
1333 | kfree(b_entry_name); | |
1334 | kfree(buffer); | |
d3533d72 JL |
1335 | b_entry_name = NULL; |
1336 | buffer = NULL; | |
6dd4ee7c KS |
1337 | brelse(is->iloc.bh); |
1338 | kfree(is); | |
1339 | kfree(bs); | |
1340 | } | |
1341 | brelse(bh); | |
1342 | up_write(&EXT4_I(inode)->xattr_sem); | |
1343 | return 0; | |
1344 | ||
1345 | cleanup: | |
1346 | kfree(b_entry_name); | |
1347 | kfree(buffer); | |
1348 | if (is) | |
1349 | brelse(is->iloc.bh); | |
1350 | kfree(is); | |
1351 | kfree(bs); | |
1352 | brelse(bh); | |
1353 | up_write(&EXT4_I(inode)->xattr_sem); | |
1354 | return error; | |
1355 | } | |
1356 | ||
1357 | ||
1358 | ||
ac27a0ec | 1359 | /* |
617ba13b | 1360 | * ext4_xattr_delete_inode() |
ac27a0ec DK |
1361 | * |
1362 | * Free extended attribute resources associated with this inode. This | |
1363 | * is called immediately before an inode is freed. We have exclusive | |
1364 | * access to the inode. | |
1365 | */ | |
1366 | void | |
617ba13b | 1367 | ext4_xattr_delete_inode(handle_t *handle, struct inode *inode) |
ac27a0ec DK |
1368 | { |
1369 | struct buffer_head *bh = NULL; | |
1370 | ||
617ba13b | 1371 | if (!EXT4_I(inode)->i_file_acl) |
ac27a0ec | 1372 | goto cleanup; |
617ba13b | 1373 | bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl); |
ac27a0ec | 1374 | if (!bh) { |
12062ddd ES |
1375 | ext4_error(inode->i_sb, "inode %lu: block %llu read error", |
1376 | inode->i_ino, EXT4_I(inode)->i_file_acl); | |
ac27a0ec DK |
1377 | goto cleanup; |
1378 | } | |
617ba13b | 1379 | if (BHDR(bh)->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC) || |
ac27a0ec | 1380 | BHDR(bh)->h_blocks != cpu_to_le32(1)) { |
12062ddd ES |
1381 | ext4_error(inode->i_sb, "inode %lu: bad block %llu", |
1382 | inode->i_ino, EXT4_I(inode)->i_file_acl); | |
ac27a0ec DK |
1383 | goto cleanup; |
1384 | } | |
617ba13b MC |
1385 | ext4_xattr_release_block(handle, inode, bh); |
1386 | EXT4_I(inode)->i_file_acl = 0; | |
ac27a0ec DK |
1387 | |
1388 | cleanup: | |
1389 | brelse(bh); | |
1390 | } | |
1391 | ||
1392 | /* | |
617ba13b | 1393 | * ext4_xattr_put_super() |
ac27a0ec DK |
1394 | * |
1395 | * This is called when a file system is unmounted. | |
1396 | */ | |
1397 | void | |
617ba13b | 1398 | ext4_xattr_put_super(struct super_block *sb) |
ac27a0ec DK |
1399 | { |
1400 | mb_cache_shrink(sb->s_bdev); | |
1401 | } | |
1402 | ||
1403 | /* | |
617ba13b | 1404 | * ext4_xattr_cache_insert() |
ac27a0ec DK |
1405 | * |
1406 | * Create a new entry in the extended attribute cache, and insert | |
1407 | * it unless such an entry is already in the cache. | |
1408 | * | |
1409 | * Returns 0, or a negative error number on failure. | |
1410 | */ | |
1411 | static void | |
617ba13b | 1412 | ext4_xattr_cache_insert(struct buffer_head *bh) |
ac27a0ec DK |
1413 | { |
1414 | __u32 hash = le32_to_cpu(BHDR(bh)->h_hash); | |
1415 | struct mb_cache_entry *ce; | |
1416 | int error; | |
1417 | ||
335e92e8 | 1418 | ce = mb_cache_entry_alloc(ext4_xattr_cache, GFP_NOFS); |
ac27a0ec DK |
1419 | if (!ce) { |
1420 | ea_bdebug(bh, "out of memory"); | |
1421 | return; | |
1422 | } | |
1423 | error = mb_cache_entry_insert(ce, bh->b_bdev, bh->b_blocknr, &hash); | |
1424 | if (error) { | |
1425 | mb_cache_entry_free(ce); | |
1426 | if (error == -EBUSY) { | |
1427 | ea_bdebug(bh, "already in cache"); | |
1428 | error = 0; | |
1429 | } | |
1430 | } else { | |
1431 | ea_bdebug(bh, "inserting [%x]", (int)hash); | |
1432 | mb_cache_entry_release(ce); | |
1433 | } | |
1434 | } | |
1435 | ||
1436 | /* | |
617ba13b | 1437 | * ext4_xattr_cmp() |
ac27a0ec DK |
1438 | * |
1439 | * Compare two extended attribute blocks for equality. | |
1440 | * | |
1441 | * Returns 0 if the blocks are equal, 1 if they differ, and | |
1442 | * a negative error number on errors. | |
1443 | */ | |
1444 | static int | |
617ba13b MC |
1445 | ext4_xattr_cmp(struct ext4_xattr_header *header1, |
1446 | struct ext4_xattr_header *header2) | |
ac27a0ec | 1447 | { |
617ba13b | 1448 | struct ext4_xattr_entry *entry1, *entry2; |
ac27a0ec DK |
1449 | |
1450 | entry1 = ENTRY(header1+1); | |
1451 | entry2 = ENTRY(header2+1); | |
1452 | while (!IS_LAST_ENTRY(entry1)) { | |
1453 | if (IS_LAST_ENTRY(entry2)) | |
1454 | return 1; | |
1455 | if (entry1->e_hash != entry2->e_hash || | |
1456 | entry1->e_name_index != entry2->e_name_index || | |
1457 | entry1->e_name_len != entry2->e_name_len || | |
1458 | entry1->e_value_size != entry2->e_value_size || | |
1459 | memcmp(entry1->e_name, entry2->e_name, entry1->e_name_len)) | |
1460 | return 1; | |
1461 | if (entry1->e_value_block != 0 || entry2->e_value_block != 0) | |
1462 | return -EIO; | |
1463 | if (memcmp((char *)header1 + le16_to_cpu(entry1->e_value_offs), | |
1464 | (char *)header2 + le16_to_cpu(entry2->e_value_offs), | |
1465 | le32_to_cpu(entry1->e_value_size))) | |
1466 | return 1; | |
1467 | ||
617ba13b MC |
1468 | entry1 = EXT4_XATTR_NEXT(entry1); |
1469 | entry2 = EXT4_XATTR_NEXT(entry2); | |
ac27a0ec DK |
1470 | } |
1471 | if (!IS_LAST_ENTRY(entry2)) | |
1472 | return 1; | |
1473 | return 0; | |
1474 | } | |
1475 | ||
1476 | /* | |
617ba13b | 1477 | * ext4_xattr_cache_find() |
ac27a0ec DK |
1478 | * |
1479 | * Find an identical extended attribute block. | |
1480 | * | |
1481 | * Returns a pointer to the block found, or NULL if such a block was | |
1482 | * not found or an error occurred. | |
1483 | */ | |
1484 | static struct buffer_head * | |
617ba13b | 1485 | ext4_xattr_cache_find(struct inode *inode, struct ext4_xattr_header *header, |
ac27a0ec DK |
1486 | struct mb_cache_entry **pce) |
1487 | { | |
1488 | __u32 hash = le32_to_cpu(header->h_hash); | |
1489 | struct mb_cache_entry *ce; | |
1490 | ||
1491 | if (!header->h_hash) | |
1492 | return NULL; /* never share */ | |
1493 | ea_idebug(inode, "looking for cached blocks [%x]", (int)hash); | |
1494 | again: | |
617ba13b | 1495 | ce = mb_cache_entry_find_first(ext4_xattr_cache, 0, |
ac27a0ec DK |
1496 | inode->i_sb->s_bdev, hash); |
1497 | while (ce) { | |
1498 | struct buffer_head *bh; | |
1499 | ||
1500 | if (IS_ERR(ce)) { | |
1501 | if (PTR_ERR(ce) == -EAGAIN) | |
1502 | goto again; | |
1503 | break; | |
1504 | } | |
1505 | bh = sb_bread(inode->i_sb, ce->e_block); | |
1506 | if (!bh) { | |
12062ddd | 1507 | ext4_error(inode->i_sb, |
ac27a0ec DK |
1508 | "inode %lu: block %lu read error", |
1509 | inode->i_ino, (unsigned long) ce->e_block); | |
1510 | } else if (le32_to_cpu(BHDR(bh)->h_refcount) >= | |
617ba13b | 1511 | EXT4_XATTR_REFCOUNT_MAX) { |
ac27a0ec DK |
1512 | ea_idebug(inode, "block %lu refcount %d>=%d", |
1513 | (unsigned long) ce->e_block, | |
1514 | le32_to_cpu(BHDR(bh)->h_refcount), | |
617ba13b MC |
1515 | EXT4_XATTR_REFCOUNT_MAX); |
1516 | } else if (ext4_xattr_cmp(header, BHDR(bh)) == 0) { | |
ac27a0ec DK |
1517 | *pce = ce; |
1518 | return bh; | |
1519 | } | |
1520 | brelse(bh); | |
1521 | ce = mb_cache_entry_find_next(ce, 0, inode->i_sb->s_bdev, hash); | |
1522 | } | |
1523 | return NULL; | |
1524 | } | |
1525 | ||
1526 | #define NAME_HASH_SHIFT 5 | |
1527 | #define VALUE_HASH_SHIFT 16 | |
1528 | ||
1529 | /* | |
617ba13b | 1530 | * ext4_xattr_hash_entry() |
ac27a0ec DK |
1531 | * |
1532 | * Compute the hash of an extended attribute. | |
1533 | */ | |
617ba13b MC |
1534 | static inline void ext4_xattr_hash_entry(struct ext4_xattr_header *header, |
1535 | struct ext4_xattr_entry *entry) | |
ac27a0ec DK |
1536 | { |
1537 | __u32 hash = 0; | |
1538 | char *name = entry->e_name; | |
1539 | int n; | |
1540 | ||
2b2d6d01 | 1541 | for (n = 0; n < entry->e_name_len; n++) { |
ac27a0ec DK |
1542 | hash = (hash << NAME_HASH_SHIFT) ^ |
1543 | (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^ | |
1544 | *name++; | |
1545 | } | |
1546 | ||
1547 | if (entry->e_value_block == 0 && entry->e_value_size != 0) { | |
1548 | __le32 *value = (__le32 *)((char *)header + | |
1549 | le16_to_cpu(entry->e_value_offs)); | |
1550 | for (n = (le32_to_cpu(entry->e_value_size) + | |
617ba13b | 1551 | EXT4_XATTR_ROUND) >> EXT4_XATTR_PAD_BITS; n; n--) { |
ac27a0ec DK |
1552 | hash = (hash << VALUE_HASH_SHIFT) ^ |
1553 | (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^ | |
1554 | le32_to_cpu(*value++); | |
1555 | } | |
1556 | } | |
1557 | entry->e_hash = cpu_to_le32(hash); | |
1558 | } | |
1559 | ||
1560 | #undef NAME_HASH_SHIFT | |
1561 | #undef VALUE_HASH_SHIFT | |
1562 | ||
1563 | #define BLOCK_HASH_SHIFT 16 | |
1564 | ||
1565 | /* | |
617ba13b | 1566 | * ext4_xattr_rehash() |
ac27a0ec DK |
1567 | * |
1568 | * Re-compute the extended attribute hash value after an entry has changed. | |
1569 | */ | |
617ba13b MC |
1570 | static void ext4_xattr_rehash(struct ext4_xattr_header *header, |
1571 | struct ext4_xattr_entry *entry) | |
ac27a0ec | 1572 | { |
617ba13b | 1573 | struct ext4_xattr_entry *here; |
ac27a0ec DK |
1574 | __u32 hash = 0; |
1575 | ||
617ba13b | 1576 | ext4_xattr_hash_entry(header, entry); |
ac27a0ec DK |
1577 | here = ENTRY(header+1); |
1578 | while (!IS_LAST_ENTRY(here)) { | |
1579 | if (!here->e_hash) { | |
1580 | /* Block is not shared if an entry's hash value == 0 */ | |
1581 | hash = 0; | |
1582 | break; | |
1583 | } | |
1584 | hash = (hash << BLOCK_HASH_SHIFT) ^ | |
1585 | (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^ | |
1586 | le32_to_cpu(here->e_hash); | |
617ba13b | 1587 | here = EXT4_XATTR_NEXT(here); |
ac27a0ec DK |
1588 | } |
1589 | header->h_hash = cpu_to_le32(hash); | |
1590 | } | |
1591 | ||
1592 | #undef BLOCK_HASH_SHIFT | |
1593 | ||
1594 | int __init | |
617ba13b | 1595 | init_ext4_xattr(void) |
ac27a0ec | 1596 | { |
617ba13b | 1597 | ext4_xattr_cache = mb_cache_create("ext4_xattr", NULL, |
ac27a0ec DK |
1598 | sizeof(struct mb_cache_entry) + |
1599 | sizeof(((struct mb_cache_entry *) 0)->e_indexes[0]), 1, 6); | |
617ba13b | 1600 | if (!ext4_xattr_cache) |
ac27a0ec DK |
1601 | return -ENOMEM; |
1602 | return 0; | |
1603 | } | |
1604 | ||
1605 | void | |
617ba13b | 1606 | exit_ext4_xattr(void) |
ac27a0ec | 1607 | { |
617ba13b MC |
1608 | if (ext4_xattr_cache) |
1609 | mb_cache_destroy(ext4_xattr_cache); | |
1610 | ext4_xattr_cache = NULL; | |
ac27a0ec | 1611 | } |