Commit | Line | Data |
---|---|---|
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> | |
dab291af | 56 | #include <linux/ext4_jbd2.h> |
617ba13b | 57 | #include <linux/ext4_fs.h> |
ac27a0ec DK |
58 | #include <linux/mbcache.h> |
59 | #include <linux/quotaops.h> | |
60 | #include <linux/rwsem.h> | |
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 | ||
69 | #define IHDR(inode, raw_inode) \ | |
617ba13b | 70 | ((struct ext4_xattr_ibody_header *) \ |
ac27a0ec | 71 | ((void *)raw_inode + \ |
617ba13b MC |
72 | EXT4_GOOD_OLD_INODE_SIZE + \ |
73 | EXT4_I(inode)->i_extra_isize)) | |
74 | #define IFIRST(hdr) ((struct ext4_xattr_entry *)((hdr)+1)) | |
ac27a0ec | 75 | |
617ba13b | 76 | #ifdef EXT4_XATTR_DEBUG |
ac27a0ec DK |
77 | # define ea_idebug(inode, f...) do { \ |
78 | printk(KERN_DEBUG "inode %s:%lu: ", \ | |
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 | ||
617ba13b MC |
96 | static void ext4_xattr_cache_insert(struct buffer_head *); |
97 | static struct buffer_head *ext4_xattr_cache_find(struct inode *, | |
98 | struct ext4_xattr_header *, | |
ac27a0ec | 99 | struct mb_cache_entry **); |
617ba13b MC |
100 | static void ext4_xattr_rehash(struct ext4_xattr_header *, |
101 | struct ext4_xattr_entry *); | |
ac27a0ec | 102 | |
617ba13b | 103 | static struct mb_cache *ext4_xattr_cache; |
ac27a0ec | 104 | |
617ba13b MC |
105 | static struct xattr_handler *ext4_xattr_handler_map[] = { |
106 | [EXT4_XATTR_INDEX_USER] = &ext4_xattr_user_handler, | |
107 | #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL | |
108 | [EXT4_XATTR_INDEX_POSIX_ACL_ACCESS] = &ext4_xattr_acl_access_handler, | |
109 | [EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT] = &ext4_xattr_acl_default_handler, | |
ac27a0ec | 110 | #endif |
617ba13b MC |
111 | [EXT4_XATTR_INDEX_TRUSTED] = &ext4_xattr_trusted_handler, |
112 | #ifdef CONFIG_EXT4DEV_FS_SECURITY | |
113 | [EXT4_XATTR_INDEX_SECURITY] = &ext4_xattr_security_handler, | |
ac27a0ec DK |
114 | #endif |
115 | }; | |
116 | ||
617ba13b MC |
117 | struct xattr_handler *ext4_xattr_handlers[] = { |
118 | &ext4_xattr_user_handler, | |
119 | &ext4_xattr_trusted_handler, | |
120 | #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL | |
121 | &ext4_xattr_acl_access_handler, | |
122 | &ext4_xattr_acl_default_handler, | |
ac27a0ec | 123 | #endif |
617ba13b MC |
124 | #ifdef CONFIG_EXT4DEV_FS_SECURITY |
125 | &ext4_xattr_security_handler, | |
ac27a0ec DK |
126 | #endif |
127 | NULL | |
128 | }; | |
129 | ||
130 | static inline struct xattr_handler * | |
617ba13b | 131 | ext4_xattr_handler(int name_index) |
ac27a0ec DK |
132 | { |
133 | struct xattr_handler *handler = NULL; | |
134 | ||
617ba13b MC |
135 | if (name_index > 0 && name_index < ARRAY_SIZE(ext4_xattr_handler_map)) |
136 | handler = ext4_xattr_handler_map[name_index]; | |
ac27a0ec DK |
137 | return handler; |
138 | } | |
139 | ||
140 | /* | |
141 | * Inode operation listxattr() | |
142 | * | |
143 | * dentry->d_inode->i_mutex: don't care | |
144 | */ | |
145 | ssize_t | |
617ba13b | 146 | ext4_listxattr(struct dentry *dentry, char *buffer, size_t size) |
ac27a0ec | 147 | { |
617ba13b | 148 | return ext4_xattr_list(dentry->d_inode, buffer, size); |
ac27a0ec DK |
149 | } |
150 | ||
151 | static int | |
617ba13b | 152 | ext4_xattr_check_names(struct ext4_xattr_entry *entry, void *end) |
ac27a0ec DK |
153 | { |
154 | while (!IS_LAST_ENTRY(entry)) { | |
617ba13b | 155 | struct ext4_xattr_entry *next = EXT4_XATTR_NEXT(entry); |
ac27a0ec DK |
156 | if ((void *)next >= end) |
157 | return -EIO; | |
158 | entry = next; | |
159 | } | |
160 | return 0; | |
161 | } | |
162 | ||
163 | static inline int | |
617ba13b | 164 | ext4_xattr_check_block(struct buffer_head *bh) |
ac27a0ec DK |
165 | { |
166 | int error; | |
167 | ||
617ba13b | 168 | if (BHDR(bh)->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC) || |
ac27a0ec DK |
169 | BHDR(bh)->h_blocks != cpu_to_le32(1)) |
170 | return -EIO; | |
617ba13b | 171 | error = ext4_xattr_check_names(BFIRST(bh), bh->b_data + bh->b_size); |
ac27a0ec DK |
172 | return error; |
173 | } | |
174 | ||
175 | static inline int | |
617ba13b | 176 | ext4_xattr_check_entry(struct ext4_xattr_entry *entry, size_t size) |
ac27a0ec DK |
177 | { |
178 | size_t value_size = le32_to_cpu(entry->e_value_size); | |
179 | ||
180 | if (entry->e_value_block != 0 || value_size > size || | |
181 | le16_to_cpu(entry->e_value_offs) + value_size > size) | |
182 | return -EIO; | |
183 | return 0; | |
184 | } | |
185 | ||
186 | static int | |
617ba13b | 187 | ext4_xattr_find_entry(struct ext4_xattr_entry **pentry, int name_index, |
ac27a0ec DK |
188 | const char *name, size_t size, int sorted) |
189 | { | |
617ba13b | 190 | struct ext4_xattr_entry *entry; |
ac27a0ec DK |
191 | size_t name_len; |
192 | int cmp = 1; | |
193 | ||
194 | if (name == NULL) | |
195 | return -EINVAL; | |
196 | name_len = strlen(name); | |
197 | entry = *pentry; | |
617ba13b | 198 | for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) { |
ac27a0ec DK |
199 | cmp = name_index - entry->e_name_index; |
200 | if (!cmp) | |
201 | cmp = name_len - entry->e_name_len; | |
202 | if (!cmp) | |
203 | cmp = memcmp(name, entry->e_name, name_len); | |
204 | if (cmp <= 0 && (sorted || cmp == 0)) | |
205 | break; | |
206 | } | |
207 | *pentry = entry; | |
617ba13b | 208 | if (!cmp && ext4_xattr_check_entry(entry, size)) |
ac27a0ec DK |
209 | return -EIO; |
210 | return cmp ? -ENODATA : 0; | |
211 | } | |
212 | ||
213 | static int | |
617ba13b | 214 | ext4_xattr_block_get(struct inode *inode, int name_index, const char *name, |
ac27a0ec DK |
215 | void *buffer, size_t buffer_size) |
216 | { | |
217 | struct buffer_head *bh = NULL; | |
617ba13b | 218 | struct ext4_xattr_entry *entry; |
ac27a0ec DK |
219 | size_t size; |
220 | int error; | |
221 | ||
222 | ea_idebug(inode, "name=%d.%s, buffer=%p, buffer_size=%ld", | |
223 | name_index, name, buffer, (long)buffer_size); | |
224 | ||
225 | error = -ENODATA; | |
617ba13b | 226 | if (!EXT4_I(inode)->i_file_acl) |
ac27a0ec | 227 | goto cleanup; |
617ba13b MC |
228 | ea_idebug(inode, "reading block %u", EXT4_I(inode)->i_file_acl); |
229 | bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl); | |
ac27a0ec DK |
230 | if (!bh) |
231 | goto cleanup; | |
232 | ea_bdebug(bh, "b_count=%d, refcount=%d", | |
233 | atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount)); | |
617ba13b MC |
234 | if (ext4_xattr_check_block(bh)) { |
235 | bad_block: ext4_error(inode->i_sb, __FUNCTION__, | |
2ae02107 | 236 | "inode %lu: bad block %llu", inode->i_ino, |
617ba13b | 237 | EXT4_I(inode)->i_file_acl); |
ac27a0ec DK |
238 | error = -EIO; |
239 | goto cleanup; | |
240 | } | |
617ba13b | 241 | ext4_xattr_cache_insert(bh); |
ac27a0ec | 242 | entry = BFIRST(bh); |
617ba13b | 243 | error = ext4_xattr_find_entry(&entry, name_index, name, bh->b_size, 1); |
ac27a0ec DK |
244 | if (error == -EIO) |
245 | goto bad_block; | |
246 | if (error) | |
247 | goto cleanup; | |
248 | size = le32_to_cpu(entry->e_value_size); | |
249 | if (buffer) { | |
250 | error = -ERANGE; | |
251 | if (size > buffer_size) | |
252 | goto cleanup; | |
253 | memcpy(buffer, bh->b_data + le16_to_cpu(entry->e_value_offs), | |
254 | size); | |
255 | } | |
256 | error = size; | |
257 | ||
258 | cleanup: | |
259 | brelse(bh); | |
260 | return error; | |
261 | } | |
262 | ||
263 | static int | |
617ba13b | 264 | ext4_xattr_ibody_get(struct inode *inode, int name_index, const char *name, |
ac27a0ec DK |
265 | void *buffer, size_t buffer_size) |
266 | { | |
617ba13b MC |
267 | struct ext4_xattr_ibody_header *header; |
268 | struct ext4_xattr_entry *entry; | |
269 | struct ext4_inode *raw_inode; | |
270 | struct ext4_iloc iloc; | |
ac27a0ec DK |
271 | size_t size; |
272 | void *end; | |
273 | int error; | |
274 | ||
617ba13b | 275 | if (!(EXT4_I(inode)->i_state & EXT4_STATE_XATTR)) |
ac27a0ec | 276 | return -ENODATA; |
617ba13b | 277 | error = ext4_get_inode_loc(inode, &iloc); |
ac27a0ec DK |
278 | if (error) |
279 | return error; | |
617ba13b | 280 | raw_inode = ext4_raw_inode(&iloc); |
ac27a0ec DK |
281 | header = IHDR(inode, raw_inode); |
282 | entry = IFIRST(header); | |
617ba13b MC |
283 | end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; |
284 | error = ext4_xattr_check_names(entry, end); | |
ac27a0ec DK |
285 | if (error) |
286 | goto cleanup; | |
617ba13b | 287 | error = ext4_xattr_find_entry(&entry, name_index, name, |
ac27a0ec DK |
288 | end - (void *)entry, 0); |
289 | if (error) | |
290 | goto cleanup; | |
291 | size = le32_to_cpu(entry->e_value_size); | |
292 | if (buffer) { | |
293 | error = -ERANGE; | |
294 | if (size > buffer_size) | |
295 | goto cleanup; | |
296 | memcpy(buffer, (void *)IFIRST(header) + | |
297 | le16_to_cpu(entry->e_value_offs), size); | |
298 | } | |
299 | error = size; | |
300 | ||
301 | cleanup: | |
302 | brelse(iloc.bh); | |
303 | return error; | |
304 | } | |
305 | ||
306 | /* | |
617ba13b | 307 | * ext4_xattr_get() |
ac27a0ec DK |
308 | * |
309 | * Copy an extended attribute into the buffer | |
310 | * provided, or compute the buffer size required. | |
311 | * Buffer is NULL to compute the size of the buffer required. | |
312 | * | |
313 | * Returns a negative error number on failure, or the number of bytes | |
314 | * used / required on success. | |
315 | */ | |
316 | int | |
617ba13b | 317 | ext4_xattr_get(struct inode *inode, int name_index, const char *name, |
ac27a0ec DK |
318 | void *buffer, size_t buffer_size) |
319 | { | |
320 | int error; | |
321 | ||
617ba13b MC |
322 | down_read(&EXT4_I(inode)->xattr_sem); |
323 | error = ext4_xattr_ibody_get(inode, name_index, name, buffer, | |
ac27a0ec DK |
324 | buffer_size); |
325 | if (error == -ENODATA) | |
617ba13b | 326 | error = ext4_xattr_block_get(inode, name_index, name, buffer, |
ac27a0ec | 327 | buffer_size); |
617ba13b | 328 | up_read(&EXT4_I(inode)->xattr_sem); |
ac27a0ec DK |
329 | return error; |
330 | } | |
331 | ||
332 | static int | |
617ba13b | 333 | ext4_xattr_list_entries(struct inode *inode, struct ext4_xattr_entry *entry, |
ac27a0ec DK |
334 | char *buffer, size_t buffer_size) |
335 | { | |
336 | size_t rest = buffer_size; | |
337 | ||
617ba13b | 338 | for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) { |
ac27a0ec | 339 | struct xattr_handler *handler = |
617ba13b | 340 | ext4_xattr_handler(entry->e_name_index); |
ac27a0ec DK |
341 | |
342 | if (handler) { | |
343 | size_t size = handler->list(inode, buffer, rest, | |
344 | entry->e_name, | |
345 | entry->e_name_len); | |
346 | if (buffer) { | |
347 | if (size > rest) | |
348 | return -ERANGE; | |
349 | buffer += size; | |
350 | } | |
351 | rest -= size; | |
352 | } | |
353 | } | |
354 | return buffer_size - rest; | |
355 | } | |
356 | ||
357 | static int | |
617ba13b | 358 | ext4_xattr_block_list(struct inode *inode, char *buffer, size_t buffer_size) |
ac27a0ec DK |
359 | { |
360 | struct buffer_head *bh = NULL; | |
361 | int error; | |
362 | ||
363 | ea_idebug(inode, "buffer=%p, buffer_size=%ld", | |
364 | buffer, (long)buffer_size); | |
365 | ||
366 | error = 0; | |
617ba13b | 367 | if (!EXT4_I(inode)->i_file_acl) |
ac27a0ec | 368 | goto cleanup; |
617ba13b MC |
369 | ea_idebug(inode, "reading block %u", EXT4_I(inode)->i_file_acl); |
370 | bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl); | |
ac27a0ec DK |
371 | error = -EIO; |
372 | if (!bh) | |
373 | goto cleanup; | |
374 | ea_bdebug(bh, "b_count=%d, refcount=%d", | |
375 | atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount)); | |
617ba13b MC |
376 | if (ext4_xattr_check_block(bh)) { |
377 | ext4_error(inode->i_sb, __FUNCTION__, | |
2ae02107 | 378 | "inode %lu: bad block %llu", inode->i_ino, |
617ba13b | 379 | EXT4_I(inode)->i_file_acl); |
ac27a0ec DK |
380 | error = -EIO; |
381 | goto cleanup; | |
382 | } | |
617ba13b MC |
383 | ext4_xattr_cache_insert(bh); |
384 | error = ext4_xattr_list_entries(inode, BFIRST(bh), buffer, buffer_size); | |
ac27a0ec DK |
385 | |
386 | cleanup: | |
387 | brelse(bh); | |
388 | ||
389 | return error; | |
390 | } | |
391 | ||
392 | static int | |
617ba13b | 393 | ext4_xattr_ibody_list(struct inode *inode, char *buffer, size_t buffer_size) |
ac27a0ec | 394 | { |
617ba13b MC |
395 | struct ext4_xattr_ibody_header *header; |
396 | struct ext4_inode *raw_inode; | |
397 | struct ext4_iloc iloc; | |
ac27a0ec DK |
398 | void *end; |
399 | int error; | |
400 | ||
617ba13b | 401 | if (!(EXT4_I(inode)->i_state & EXT4_STATE_XATTR)) |
ac27a0ec | 402 | return 0; |
617ba13b | 403 | error = ext4_get_inode_loc(inode, &iloc); |
ac27a0ec DK |
404 | if (error) |
405 | return error; | |
617ba13b | 406 | raw_inode = ext4_raw_inode(&iloc); |
ac27a0ec | 407 | header = IHDR(inode, raw_inode); |
617ba13b MC |
408 | end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; |
409 | error = ext4_xattr_check_names(IFIRST(header), end); | |
ac27a0ec DK |
410 | if (error) |
411 | goto cleanup; | |
617ba13b | 412 | error = ext4_xattr_list_entries(inode, IFIRST(header), |
ac27a0ec DK |
413 | buffer, buffer_size); |
414 | ||
415 | cleanup: | |
416 | brelse(iloc.bh); | |
417 | return error; | |
418 | } | |
419 | ||
420 | /* | |
617ba13b | 421 | * ext4_xattr_list() |
ac27a0ec DK |
422 | * |
423 | * Copy a list of attribute names into the buffer | |
424 | * provided, or compute the buffer size required. | |
425 | * Buffer is NULL to compute the size of the buffer required. | |
426 | * | |
427 | * Returns a negative error number on failure, or the number of bytes | |
428 | * used / required on success. | |
429 | */ | |
430 | int | |
617ba13b | 431 | ext4_xattr_list(struct inode *inode, char *buffer, size_t buffer_size) |
ac27a0ec DK |
432 | { |
433 | int i_error, b_error; | |
434 | ||
617ba13b MC |
435 | down_read(&EXT4_I(inode)->xattr_sem); |
436 | i_error = ext4_xattr_ibody_list(inode, buffer, buffer_size); | |
ac27a0ec DK |
437 | if (i_error < 0) { |
438 | b_error = 0; | |
439 | } else { | |
440 | if (buffer) { | |
441 | buffer += i_error; | |
442 | buffer_size -= i_error; | |
443 | } | |
617ba13b | 444 | b_error = ext4_xattr_block_list(inode, buffer, buffer_size); |
ac27a0ec DK |
445 | if (b_error < 0) |
446 | i_error = 0; | |
447 | } | |
617ba13b | 448 | up_read(&EXT4_I(inode)->xattr_sem); |
ac27a0ec DK |
449 | return i_error + b_error; |
450 | } | |
451 | ||
452 | /* | |
617ba13b | 453 | * If the EXT4_FEATURE_COMPAT_EXT_ATTR feature of this file system is |
ac27a0ec DK |
454 | * not set, set it. |
455 | */ | |
617ba13b | 456 | static void ext4_xattr_update_super_block(handle_t *handle, |
ac27a0ec DK |
457 | struct super_block *sb) |
458 | { | |
617ba13b | 459 | if (EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_EXT_ATTR)) |
ac27a0ec DK |
460 | return; |
461 | ||
617ba13b | 462 | if (ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh) == 0) { |
ed2908f3 | 463 | EXT4_SET_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_EXT_ATTR); |
ac27a0ec | 464 | sb->s_dirt = 1; |
617ba13b | 465 | ext4_journal_dirty_metadata(handle, EXT4_SB(sb)->s_sbh); |
ac27a0ec | 466 | } |
ac27a0ec DK |
467 | } |
468 | ||
469 | /* | |
470 | * Release the xattr block BH: If the reference count is > 1, decrement | |
471 | * it; otherwise free the block. | |
472 | */ | |
473 | static void | |
617ba13b | 474 | ext4_xattr_release_block(handle_t *handle, struct inode *inode, |
ac27a0ec DK |
475 | struct buffer_head *bh) |
476 | { | |
477 | struct mb_cache_entry *ce = NULL; | |
478 | ||
617ba13b | 479 | ce = mb_cache_entry_get(ext4_xattr_cache, bh->b_bdev, bh->b_blocknr); |
ac27a0ec DK |
480 | if (BHDR(bh)->h_refcount == cpu_to_le32(1)) { |
481 | ea_bdebug(bh, "refcount now=0; freeing"); | |
482 | if (ce) | |
483 | mb_cache_entry_free(ce); | |
617ba13b | 484 | ext4_free_blocks(handle, inode, bh->b_blocknr, 1); |
ac27a0ec | 485 | get_bh(bh); |
617ba13b | 486 | ext4_forget(handle, 1, inode, bh, bh->b_blocknr); |
ac27a0ec | 487 | } else { |
617ba13b | 488 | if (ext4_journal_get_write_access(handle, bh) == 0) { |
ac27a0ec DK |
489 | lock_buffer(bh); |
490 | BHDR(bh)->h_refcount = cpu_to_le32( | |
491 | le32_to_cpu(BHDR(bh)->h_refcount) - 1); | |
617ba13b | 492 | ext4_journal_dirty_metadata(handle, bh); |
ac27a0ec DK |
493 | if (IS_SYNC(inode)) |
494 | handle->h_sync = 1; | |
495 | DQUOT_FREE_BLOCK(inode, 1); | |
496 | unlock_buffer(bh); | |
497 | ea_bdebug(bh, "refcount now=%d; releasing", | |
498 | le32_to_cpu(BHDR(bh)->h_refcount)); | |
499 | } | |
500 | if (ce) | |
501 | mb_cache_entry_release(ce); | |
502 | } | |
503 | } | |
504 | ||
617ba13b | 505 | struct ext4_xattr_info { |
ac27a0ec DK |
506 | int name_index; |
507 | const char *name; | |
508 | const void *value; | |
509 | size_t value_len; | |
510 | }; | |
511 | ||
617ba13b MC |
512 | struct ext4_xattr_search { |
513 | struct ext4_xattr_entry *first; | |
ac27a0ec DK |
514 | void *base; |
515 | void *end; | |
617ba13b | 516 | struct ext4_xattr_entry *here; |
ac27a0ec DK |
517 | int not_found; |
518 | }; | |
519 | ||
520 | static int | |
617ba13b | 521 | ext4_xattr_set_entry(struct ext4_xattr_info *i, struct ext4_xattr_search *s) |
ac27a0ec | 522 | { |
617ba13b | 523 | struct ext4_xattr_entry *last; |
ac27a0ec DK |
524 | size_t free, min_offs = s->end - s->base, name_len = strlen(i->name); |
525 | ||
526 | /* Compute min_offs and last. */ | |
527 | last = s->first; | |
617ba13b | 528 | for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) { |
ac27a0ec DK |
529 | if (!last->e_value_block && last->e_value_size) { |
530 | size_t offs = le16_to_cpu(last->e_value_offs); | |
531 | if (offs < min_offs) | |
532 | min_offs = offs; | |
533 | } | |
534 | } | |
535 | free = min_offs - ((void *)last - s->base) - sizeof(__u32); | |
536 | if (!s->not_found) { | |
537 | if (!s->here->e_value_block && s->here->e_value_size) { | |
538 | size_t size = le32_to_cpu(s->here->e_value_size); | |
617ba13b | 539 | free += EXT4_XATTR_SIZE(size); |
ac27a0ec | 540 | } |
617ba13b | 541 | free += EXT4_XATTR_LEN(name_len); |
ac27a0ec DK |
542 | } |
543 | if (i->value) { | |
617ba13b MC |
544 | if (free < EXT4_XATTR_SIZE(i->value_len) || |
545 | free < EXT4_XATTR_LEN(name_len) + | |
546 | EXT4_XATTR_SIZE(i->value_len)) | |
ac27a0ec DK |
547 | return -ENOSPC; |
548 | } | |
549 | ||
550 | if (i->value && s->not_found) { | |
551 | /* Insert the new name. */ | |
617ba13b | 552 | size_t size = EXT4_XATTR_LEN(name_len); |
ac27a0ec DK |
553 | size_t rest = (void *)last - (void *)s->here + sizeof(__u32); |
554 | memmove((void *)s->here + size, s->here, rest); | |
555 | memset(s->here, 0, size); | |
556 | s->here->e_name_index = i->name_index; | |
557 | s->here->e_name_len = name_len; | |
558 | memcpy(s->here->e_name, i->name, name_len); | |
559 | } else { | |
560 | if (!s->here->e_value_block && s->here->e_value_size) { | |
561 | void *first_val = s->base + min_offs; | |
562 | size_t offs = le16_to_cpu(s->here->e_value_offs); | |
563 | void *val = s->base + offs; | |
617ba13b | 564 | size_t size = EXT4_XATTR_SIZE( |
ac27a0ec DK |
565 | le32_to_cpu(s->here->e_value_size)); |
566 | ||
617ba13b | 567 | if (i->value && size == EXT4_XATTR_SIZE(i->value_len)) { |
ac27a0ec DK |
568 | /* The old and the new value have the same |
569 | size. Just replace. */ | |
570 | s->here->e_value_size = | |
571 | cpu_to_le32(i->value_len); | |
617ba13b MC |
572 | memset(val + size - EXT4_XATTR_PAD, 0, |
573 | EXT4_XATTR_PAD); /* Clear pad bytes. */ | |
ac27a0ec DK |
574 | memcpy(val, i->value, i->value_len); |
575 | return 0; | |
576 | } | |
577 | ||
578 | /* Remove the old value. */ | |
579 | memmove(first_val + size, first_val, val - first_val); | |
580 | memset(first_val, 0, size); | |
581 | s->here->e_value_size = 0; | |
582 | s->here->e_value_offs = 0; | |
583 | min_offs += size; | |
584 | ||
585 | /* Adjust all value offsets. */ | |
586 | last = s->first; | |
587 | while (!IS_LAST_ENTRY(last)) { | |
588 | size_t o = le16_to_cpu(last->e_value_offs); | |
589 | if (!last->e_value_block && | |
590 | last->e_value_size && o < offs) | |
591 | last->e_value_offs = | |
592 | cpu_to_le16(o + size); | |
617ba13b | 593 | last = EXT4_XATTR_NEXT(last); |
ac27a0ec DK |
594 | } |
595 | } | |
596 | if (!i->value) { | |
597 | /* Remove the old name. */ | |
617ba13b | 598 | size_t size = EXT4_XATTR_LEN(name_len); |
ac27a0ec DK |
599 | last = ENTRY((void *)last - size); |
600 | memmove(s->here, (void *)s->here + size, | |
601 | (void *)last - (void *)s->here + sizeof(__u32)); | |
602 | memset(last, 0, size); | |
603 | } | |
604 | } | |
605 | ||
606 | if (i->value) { | |
607 | /* Insert the new value. */ | |
608 | s->here->e_value_size = cpu_to_le32(i->value_len); | |
609 | if (i->value_len) { | |
617ba13b | 610 | size_t size = EXT4_XATTR_SIZE(i->value_len); |
ac27a0ec DK |
611 | void *val = s->base + min_offs - size; |
612 | s->here->e_value_offs = cpu_to_le16(min_offs - size); | |
617ba13b MC |
613 | memset(val + size - EXT4_XATTR_PAD, 0, |
614 | EXT4_XATTR_PAD); /* Clear the pad bytes. */ | |
ac27a0ec DK |
615 | memcpy(val, i->value, i->value_len); |
616 | } | |
617 | } | |
618 | return 0; | |
619 | } | |
620 | ||
617ba13b MC |
621 | struct ext4_xattr_block_find { |
622 | struct ext4_xattr_search s; | |
ac27a0ec DK |
623 | struct buffer_head *bh; |
624 | }; | |
625 | ||
626 | static int | |
617ba13b MC |
627 | ext4_xattr_block_find(struct inode *inode, struct ext4_xattr_info *i, |
628 | struct ext4_xattr_block_find *bs) | |
ac27a0ec DK |
629 | { |
630 | struct super_block *sb = inode->i_sb; | |
631 | int error; | |
632 | ||
633 | ea_idebug(inode, "name=%d.%s, value=%p, value_len=%ld", | |
634 | i->name_index, i->name, i->value, (long)i->value_len); | |
635 | ||
617ba13b | 636 | if (EXT4_I(inode)->i_file_acl) { |
ac27a0ec | 637 | /* The inode already has an extended attribute block. */ |
617ba13b | 638 | bs->bh = sb_bread(sb, EXT4_I(inode)->i_file_acl); |
ac27a0ec DK |
639 | error = -EIO; |
640 | if (!bs->bh) | |
641 | goto cleanup; | |
642 | ea_bdebug(bs->bh, "b_count=%d, refcount=%d", | |
643 | atomic_read(&(bs->bh->b_count)), | |
644 | le32_to_cpu(BHDR(bs->bh)->h_refcount)); | |
617ba13b MC |
645 | if (ext4_xattr_check_block(bs->bh)) { |
646 | ext4_error(sb, __FUNCTION__, | |
2ae02107 | 647 | "inode %lu: bad block %llu", inode->i_ino, |
617ba13b | 648 | EXT4_I(inode)->i_file_acl); |
ac27a0ec DK |
649 | error = -EIO; |
650 | goto cleanup; | |
651 | } | |
652 | /* Find the named attribute. */ | |
653 | bs->s.base = BHDR(bs->bh); | |
654 | bs->s.first = BFIRST(bs->bh); | |
655 | bs->s.end = bs->bh->b_data + bs->bh->b_size; | |
656 | bs->s.here = bs->s.first; | |
617ba13b | 657 | error = ext4_xattr_find_entry(&bs->s.here, i->name_index, |
ac27a0ec DK |
658 | i->name, bs->bh->b_size, 1); |
659 | if (error && error != -ENODATA) | |
660 | goto cleanup; | |
661 | bs->s.not_found = error; | |
662 | } | |
663 | error = 0; | |
664 | ||
665 | cleanup: | |
666 | return error; | |
667 | } | |
668 | ||
669 | static int | |
617ba13b MC |
670 | ext4_xattr_block_set(handle_t *handle, struct inode *inode, |
671 | struct ext4_xattr_info *i, | |
672 | struct ext4_xattr_block_find *bs) | |
ac27a0ec DK |
673 | { |
674 | struct super_block *sb = inode->i_sb; | |
675 | struct buffer_head *new_bh = NULL; | |
617ba13b | 676 | struct ext4_xattr_search *s = &bs->s; |
ac27a0ec DK |
677 | struct mb_cache_entry *ce = NULL; |
678 | int error; | |
679 | ||
617ba13b | 680 | #define header(x) ((struct ext4_xattr_header *)(x)) |
ac27a0ec DK |
681 | |
682 | if (i->value && i->value_len > sb->s_blocksize) | |
683 | return -ENOSPC; | |
684 | if (s->base) { | |
617ba13b | 685 | ce = mb_cache_entry_get(ext4_xattr_cache, bs->bh->b_bdev, |
ac27a0ec DK |
686 | bs->bh->b_blocknr); |
687 | if (header(s->base)->h_refcount == cpu_to_le32(1)) { | |
688 | if (ce) { | |
689 | mb_cache_entry_free(ce); | |
690 | ce = NULL; | |
691 | } | |
692 | ea_bdebug(bs->bh, "modifying in-place"); | |
617ba13b | 693 | error = ext4_journal_get_write_access(handle, bs->bh); |
ac27a0ec DK |
694 | if (error) |
695 | goto cleanup; | |
696 | lock_buffer(bs->bh); | |
617ba13b | 697 | error = ext4_xattr_set_entry(i, s); |
ac27a0ec DK |
698 | if (!error) { |
699 | if (!IS_LAST_ENTRY(s->first)) | |
617ba13b | 700 | ext4_xattr_rehash(header(s->base), |
ac27a0ec | 701 | s->here); |
617ba13b | 702 | ext4_xattr_cache_insert(bs->bh); |
ac27a0ec DK |
703 | } |
704 | unlock_buffer(bs->bh); | |
705 | if (error == -EIO) | |
706 | goto bad_block; | |
707 | if (!error) | |
617ba13b | 708 | error = ext4_journal_dirty_metadata(handle, |
ac27a0ec DK |
709 | bs->bh); |
710 | if (error) | |
711 | goto cleanup; | |
712 | goto inserted; | |
713 | } else { | |
714 | int offset = (char *)s->here - bs->bh->b_data; | |
715 | ||
716 | if (ce) { | |
717 | mb_cache_entry_release(ce); | |
718 | ce = NULL; | |
719 | } | |
720 | ea_bdebug(bs->bh, "cloning"); | |
721 | s->base = kmalloc(bs->bh->b_size, GFP_KERNEL); | |
722 | error = -ENOMEM; | |
723 | if (s->base == NULL) | |
724 | goto cleanup; | |
725 | memcpy(s->base, BHDR(bs->bh), bs->bh->b_size); | |
726 | s->first = ENTRY(header(s->base)+1); | |
727 | header(s->base)->h_refcount = cpu_to_le32(1); | |
728 | s->here = ENTRY(s->base + offset); | |
729 | s->end = s->base + bs->bh->b_size; | |
730 | } | |
731 | } else { | |
732 | /* Allocate a buffer where we construct the new block. */ | |
733 | s->base = kmalloc(sb->s_blocksize, GFP_KERNEL); | |
734 | /* assert(header == s->base) */ | |
735 | error = -ENOMEM; | |
736 | if (s->base == NULL) | |
737 | goto cleanup; | |
738 | memset(s->base, 0, sb->s_blocksize); | |
617ba13b | 739 | header(s->base)->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC); |
ac27a0ec DK |
740 | header(s->base)->h_blocks = cpu_to_le32(1); |
741 | header(s->base)->h_refcount = cpu_to_le32(1); | |
742 | s->first = ENTRY(header(s->base)+1); | |
743 | s->here = ENTRY(header(s->base)+1); | |
744 | s->end = s->base + sb->s_blocksize; | |
745 | } | |
746 | ||
617ba13b | 747 | error = ext4_xattr_set_entry(i, s); |
ac27a0ec DK |
748 | if (error == -EIO) |
749 | goto bad_block; | |
750 | if (error) | |
751 | goto cleanup; | |
752 | if (!IS_LAST_ENTRY(s->first)) | |
617ba13b | 753 | ext4_xattr_rehash(header(s->base), s->here); |
ac27a0ec DK |
754 | |
755 | inserted: | |
756 | if (!IS_LAST_ENTRY(s->first)) { | |
617ba13b | 757 | new_bh = ext4_xattr_cache_find(inode, header(s->base), &ce); |
ac27a0ec DK |
758 | if (new_bh) { |
759 | /* We found an identical block in the cache. */ | |
760 | if (new_bh == bs->bh) | |
761 | ea_bdebug(new_bh, "keeping"); | |
762 | else { | |
763 | /* The old block is released after updating | |
764 | the inode. */ | |
765 | error = -EDQUOT; | |
766 | if (DQUOT_ALLOC_BLOCK(inode, 1)) | |
767 | goto cleanup; | |
617ba13b | 768 | error = ext4_journal_get_write_access(handle, |
ac27a0ec DK |
769 | new_bh); |
770 | if (error) | |
771 | goto cleanup_dquot; | |
772 | lock_buffer(new_bh); | |
773 | BHDR(new_bh)->h_refcount = cpu_to_le32(1 + | |
774 | le32_to_cpu(BHDR(new_bh)->h_refcount)); | |
775 | ea_bdebug(new_bh, "reusing; refcount now=%d", | |
776 | le32_to_cpu(BHDR(new_bh)->h_refcount)); | |
777 | unlock_buffer(new_bh); | |
617ba13b | 778 | error = ext4_journal_dirty_metadata(handle, |
ac27a0ec DK |
779 | new_bh); |
780 | if (error) | |
781 | goto cleanup_dquot; | |
782 | } | |
783 | mb_cache_entry_release(ce); | |
784 | ce = NULL; | |
785 | } else if (bs->bh && s->base == bs->bh->b_data) { | |
786 | /* We were modifying this block in-place. */ | |
787 | ea_bdebug(bs->bh, "keeping this block"); | |
788 | new_bh = bs->bh; | |
789 | get_bh(new_bh); | |
790 | } else { | |
791 | /* We need to allocate a new block */ | |
617ba13b MC |
792 | ext4_fsblk_t goal = le32_to_cpu( |
793 | EXT4_SB(sb)->s_es->s_first_data_block) + | |
794 | (ext4_fsblk_t)EXT4_I(inode)->i_block_group * | |
795 | EXT4_BLOCKS_PER_GROUP(sb); | |
796 | ext4_fsblk_t block = ext4_new_block(handle, inode, | |
ac27a0ec DK |
797 | goal, &error); |
798 | if (error) | |
799 | goto cleanup; | |
800 | ea_idebug(inode, "creating block %d", block); | |
801 | ||
802 | new_bh = sb_getblk(sb, block); | |
803 | if (!new_bh) { | |
804 | getblk_failed: | |
617ba13b | 805 | ext4_free_blocks(handle, inode, block, 1); |
ac27a0ec DK |
806 | error = -EIO; |
807 | goto cleanup; | |
808 | } | |
809 | lock_buffer(new_bh); | |
617ba13b | 810 | error = ext4_journal_get_create_access(handle, new_bh); |
ac27a0ec DK |
811 | if (error) { |
812 | unlock_buffer(new_bh); | |
813 | goto getblk_failed; | |
814 | } | |
815 | memcpy(new_bh->b_data, s->base, new_bh->b_size); | |
816 | set_buffer_uptodate(new_bh); | |
817 | unlock_buffer(new_bh); | |
617ba13b MC |
818 | ext4_xattr_cache_insert(new_bh); |
819 | error = ext4_journal_dirty_metadata(handle, new_bh); | |
ac27a0ec DK |
820 | if (error) |
821 | goto cleanup; | |
822 | } | |
823 | } | |
824 | ||
825 | /* Update the inode. */ | |
617ba13b | 826 | EXT4_I(inode)->i_file_acl = new_bh ? new_bh->b_blocknr : 0; |
ac27a0ec DK |
827 | |
828 | /* Drop the previous xattr block. */ | |
829 | if (bs->bh && bs->bh != new_bh) | |
617ba13b | 830 | ext4_xattr_release_block(handle, inode, bs->bh); |
ac27a0ec DK |
831 | error = 0; |
832 | ||
833 | cleanup: | |
834 | if (ce) | |
835 | mb_cache_entry_release(ce); | |
836 | brelse(new_bh); | |
837 | if (!(bs->bh && s->base == bs->bh->b_data)) | |
838 | kfree(s->base); | |
839 | ||
840 | return error; | |
841 | ||
842 | cleanup_dquot: | |
843 | DQUOT_FREE_BLOCK(inode, 1); | |
844 | goto cleanup; | |
845 | ||
846 | bad_block: | |
617ba13b | 847 | ext4_error(inode->i_sb, __FUNCTION__, |
2ae02107 | 848 | "inode %lu: bad block %llu", inode->i_ino, |
617ba13b | 849 | EXT4_I(inode)->i_file_acl); |
ac27a0ec DK |
850 | goto cleanup; |
851 | ||
852 | #undef header | |
853 | } | |
854 | ||
617ba13b MC |
855 | struct ext4_xattr_ibody_find { |
856 | struct ext4_xattr_search s; | |
857 | struct ext4_iloc iloc; | |
ac27a0ec DK |
858 | }; |
859 | ||
860 | static int | |
617ba13b MC |
861 | ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i, |
862 | struct ext4_xattr_ibody_find *is) | |
ac27a0ec | 863 | { |
617ba13b MC |
864 | struct ext4_xattr_ibody_header *header; |
865 | struct ext4_inode *raw_inode; | |
ac27a0ec DK |
866 | int error; |
867 | ||
617ba13b | 868 | if (EXT4_I(inode)->i_extra_isize == 0) |
ac27a0ec | 869 | return 0; |
617ba13b | 870 | raw_inode = ext4_raw_inode(&is->iloc); |
ac27a0ec DK |
871 | header = IHDR(inode, raw_inode); |
872 | is->s.base = is->s.first = IFIRST(header); | |
873 | is->s.here = is->s.first; | |
617ba13b MC |
874 | is->s.end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; |
875 | if (EXT4_I(inode)->i_state & EXT4_STATE_XATTR) { | |
876 | error = ext4_xattr_check_names(IFIRST(header), is->s.end); | |
ac27a0ec DK |
877 | if (error) |
878 | return error; | |
879 | /* Find the named attribute. */ | |
617ba13b | 880 | error = ext4_xattr_find_entry(&is->s.here, i->name_index, |
ac27a0ec DK |
881 | i->name, is->s.end - |
882 | (void *)is->s.base, 0); | |
883 | if (error && error != -ENODATA) | |
884 | return error; | |
885 | is->s.not_found = error; | |
886 | } | |
887 | return 0; | |
888 | } | |
889 | ||
890 | static int | |
617ba13b MC |
891 | ext4_xattr_ibody_set(handle_t *handle, struct inode *inode, |
892 | struct ext4_xattr_info *i, | |
893 | struct ext4_xattr_ibody_find *is) | |
ac27a0ec | 894 | { |
617ba13b MC |
895 | struct ext4_xattr_ibody_header *header; |
896 | struct ext4_xattr_search *s = &is->s; | |
ac27a0ec DK |
897 | int error; |
898 | ||
617ba13b | 899 | if (EXT4_I(inode)->i_extra_isize == 0) |
ac27a0ec | 900 | return -ENOSPC; |
617ba13b | 901 | error = ext4_xattr_set_entry(i, s); |
ac27a0ec DK |
902 | if (error) |
903 | return error; | |
617ba13b | 904 | header = IHDR(inode, ext4_raw_inode(&is->iloc)); |
ac27a0ec | 905 | if (!IS_LAST_ENTRY(s->first)) { |
617ba13b MC |
906 | header->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC); |
907 | EXT4_I(inode)->i_state |= EXT4_STATE_XATTR; | |
ac27a0ec DK |
908 | } else { |
909 | header->h_magic = cpu_to_le32(0); | |
617ba13b | 910 | EXT4_I(inode)->i_state &= ~EXT4_STATE_XATTR; |
ac27a0ec DK |
911 | } |
912 | return 0; | |
913 | } | |
914 | ||
915 | /* | |
617ba13b | 916 | * ext4_xattr_set_handle() |
ac27a0ec DK |
917 | * |
918 | * Create, replace or remove an extended attribute for this inode. Buffer | |
919 | * is NULL to remove an existing extended attribute, and non-NULL to | |
920 | * either replace an existing extended attribute, or create a new extended | |
921 | * attribute. The flags XATTR_REPLACE and XATTR_CREATE | |
922 | * specify that an extended attribute must exist and must not exist | |
923 | * previous to the call, respectively. | |
924 | * | |
925 | * Returns 0, or a negative error number on failure. | |
926 | */ | |
927 | int | |
617ba13b | 928 | ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index, |
ac27a0ec DK |
929 | const char *name, const void *value, size_t value_len, |
930 | int flags) | |
931 | { | |
617ba13b | 932 | struct ext4_xattr_info i = { |
ac27a0ec DK |
933 | .name_index = name_index, |
934 | .name = name, | |
935 | .value = value, | |
936 | .value_len = value_len, | |
937 | ||
938 | }; | |
617ba13b | 939 | struct ext4_xattr_ibody_find is = { |
ac27a0ec DK |
940 | .s = { .not_found = -ENODATA, }, |
941 | }; | |
617ba13b | 942 | struct ext4_xattr_block_find bs = { |
ac27a0ec DK |
943 | .s = { .not_found = -ENODATA, }, |
944 | }; | |
945 | int error; | |
946 | ||
947 | if (!name) | |
948 | return -EINVAL; | |
949 | if (strlen(name) > 255) | |
950 | return -ERANGE; | |
617ba13b MC |
951 | down_write(&EXT4_I(inode)->xattr_sem); |
952 | error = ext4_get_inode_loc(inode, &is.iloc); | |
ac27a0ec DK |
953 | if (error) |
954 | goto cleanup; | |
955 | ||
617ba13b MC |
956 | if (EXT4_I(inode)->i_state & EXT4_STATE_NEW) { |
957 | struct ext4_inode *raw_inode = ext4_raw_inode(&is.iloc); | |
958 | memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size); | |
959 | EXT4_I(inode)->i_state &= ~EXT4_STATE_NEW; | |
ac27a0ec DK |
960 | } |
961 | ||
617ba13b | 962 | error = ext4_xattr_ibody_find(inode, &i, &is); |
ac27a0ec DK |
963 | if (error) |
964 | goto cleanup; | |
965 | if (is.s.not_found) | |
617ba13b | 966 | error = ext4_xattr_block_find(inode, &i, &bs); |
ac27a0ec DK |
967 | if (error) |
968 | goto cleanup; | |
969 | if (is.s.not_found && bs.s.not_found) { | |
970 | error = -ENODATA; | |
971 | if (flags & XATTR_REPLACE) | |
972 | goto cleanup; | |
973 | error = 0; | |
974 | if (!value) | |
975 | goto cleanup; | |
976 | } else { | |
977 | error = -EEXIST; | |
978 | if (flags & XATTR_CREATE) | |
979 | goto cleanup; | |
980 | } | |
617ba13b | 981 | error = ext4_journal_get_write_access(handle, is.iloc.bh); |
ac27a0ec DK |
982 | if (error) |
983 | goto cleanup; | |
984 | if (!value) { | |
985 | if (!is.s.not_found) | |
617ba13b | 986 | error = ext4_xattr_ibody_set(handle, inode, &i, &is); |
ac27a0ec | 987 | else if (!bs.s.not_found) |
617ba13b | 988 | error = ext4_xattr_block_set(handle, inode, &i, &bs); |
ac27a0ec | 989 | } else { |
617ba13b | 990 | error = ext4_xattr_ibody_set(handle, inode, &i, &is); |
ac27a0ec DK |
991 | if (!error && !bs.s.not_found) { |
992 | i.value = NULL; | |
617ba13b | 993 | error = ext4_xattr_block_set(handle, inode, &i, &bs); |
ac27a0ec | 994 | } else if (error == -ENOSPC) { |
617ba13b | 995 | error = ext4_xattr_block_set(handle, inode, &i, &bs); |
ac27a0ec DK |
996 | if (error) |
997 | goto cleanup; | |
998 | if (!is.s.not_found) { | |
999 | i.value = NULL; | |
617ba13b | 1000 | error = ext4_xattr_ibody_set(handle, inode, &i, |
ac27a0ec DK |
1001 | &is); |
1002 | } | |
1003 | } | |
1004 | } | |
1005 | if (!error) { | |
617ba13b | 1006 | ext4_xattr_update_super_block(handle, inode->i_sb); |
ac27a0ec | 1007 | inode->i_ctime = CURRENT_TIME_SEC; |
617ba13b | 1008 | error = ext4_mark_iloc_dirty(handle, inode, &is.iloc); |
ac27a0ec | 1009 | /* |
617ba13b | 1010 | * The bh is consumed by ext4_mark_iloc_dirty, even with |
ac27a0ec DK |
1011 | * error != 0. |
1012 | */ | |
1013 | is.iloc.bh = NULL; | |
1014 | if (IS_SYNC(inode)) | |
1015 | handle->h_sync = 1; | |
1016 | } | |
1017 | ||
1018 | cleanup: | |
1019 | brelse(is.iloc.bh); | |
1020 | brelse(bs.bh); | |
617ba13b | 1021 | up_write(&EXT4_I(inode)->xattr_sem); |
ac27a0ec DK |
1022 | return error; |
1023 | } | |
1024 | ||
1025 | /* | |
617ba13b | 1026 | * ext4_xattr_set() |
ac27a0ec | 1027 | * |
617ba13b | 1028 | * Like ext4_xattr_set_handle, but start from an inode. This extended |
ac27a0ec DK |
1029 | * attribute modification is a filesystem transaction by itself. |
1030 | * | |
1031 | * Returns 0, or a negative error number on failure. | |
1032 | */ | |
1033 | int | |
617ba13b | 1034 | ext4_xattr_set(struct inode *inode, int name_index, const char *name, |
ac27a0ec DK |
1035 | const void *value, size_t value_len, int flags) |
1036 | { | |
1037 | handle_t *handle; | |
1038 | int error, retries = 0; | |
1039 | ||
1040 | retry: | |
617ba13b | 1041 | handle = ext4_journal_start(inode, EXT4_DATA_TRANS_BLOCKS(inode->i_sb)); |
ac27a0ec DK |
1042 | if (IS_ERR(handle)) { |
1043 | error = PTR_ERR(handle); | |
1044 | } else { | |
1045 | int error2; | |
1046 | ||
617ba13b | 1047 | error = ext4_xattr_set_handle(handle, inode, name_index, name, |
ac27a0ec | 1048 | value, value_len, flags); |
617ba13b | 1049 | error2 = ext4_journal_stop(handle); |
ac27a0ec | 1050 | if (error == -ENOSPC && |
617ba13b | 1051 | ext4_should_retry_alloc(inode->i_sb, &retries)) |
ac27a0ec DK |
1052 | goto retry; |
1053 | if (error == 0) | |
1054 | error = error2; | |
1055 | } | |
1056 | ||
1057 | return error; | |
1058 | } | |
1059 | ||
1060 | /* | |
617ba13b | 1061 | * ext4_xattr_delete_inode() |
ac27a0ec DK |
1062 | * |
1063 | * Free extended attribute resources associated with this inode. This | |
1064 | * is called immediately before an inode is freed. We have exclusive | |
1065 | * access to the inode. | |
1066 | */ | |
1067 | void | |
617ba13b | 1068 | ext4_xattr_delete_inode(handle_t *handle, struct inode *inode) |
ac27a0ec DK |
1069 | { |
1070 | struct buffer_head *bh = NULL; | |
1071 | ||
617ba13b | 1072 | if (!EXT4_I(inode)->i_file_acl) |
ac27a0ec | 1073 | goto cleanup; |
617ba13b | 1074 | bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl); |
ac27a0ec | 1075 | if (!bh) { |
617ba13b | 1076 | ext4_error(inode->i_sb, __FUNCTION__, |
2ae02107 | 1077 | "inode %lu: block %llu read error", inode->i_ino, |
617ba13b | 1078 | EXT4_I(inode)->i_file_acl); |
ac27a0ec DK |
1079 | goto cleanup; |
1080 | } | |
617ba13b | 1081 | if (BHDR(bh)->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC) || |
ac27a0ec | 1082 | BHDR(bh)->h_blocks != cpu_to_le32(1)) { |
617ba13b | 1083 | ext4_error(inode->i_sb, __FUNCTION__, |
2ae02107 | 1084 | "inode %lu: bad block %llu", inode->i_ino, |
617ba13b | 1085 | EXT4_I(inode)->i_file_acl); |
ac27a0ec DK |
1086 | goto cleanup; |
1087 | } | |
617ba13b MC |
1088 | ext4_xattr_release_block(handle, inode, bh); |
1089 | EXT4_I(inode)->i_file_acl = 0; | |
ac27a0ec DK |
1090 | |
1091 | cleanup: | |
1092 | brelse(bh); | |
1093 | } | |
1094 | ||
1095 | /* | |
617ba13b | 1096 | * ext4_xattr_put_super() |
ac27a0ec DK |
1097 | * |
1098 | * This is called when a file system is unmounted. | |
1099 | */ | |
1100 | void | |
617ba13b | 1101 | ext4_xattr_put_super(struct super_block *sb) |
ac27a0ec DK |
1102 | { |
1103 | mb_cache_shrink(sb->s_bdev); | |
1104 | } | |
1105 | ||
1106 | /* | |
617ba13b | 1107 | * ext4_xattr_cache_insert() |
ac27a0ec DK |
1108 | * |
1109 | * Create a new entry in the extended attribute cache, and insert | |
1110 | * it unless such an entry is already in the cache. | |
1111 | * | |
1112 | * Returns 0, or a negative error number on failure. | |
1113 | */ | |
1114 | static void | |
617ba13b | 1115 | ext4_xattr_cache_insert(struct buffer_head *bh) |
ac27a0ec DK |
1116 | { |
1117 | __u32 hash = le32_to_cpu(BHDR(bh)->h_hash); | |
1118 | struct mb_cache_entry *ce; | |
1119 | int error; | |
1120 | ||
617ba13b | 1121 | ce = mb_cache_entry_alloc(ext4_xattr_cache); |
ac27a0ec DK |
1122 | if (!ce) { |
1123 | ea_bdebug(bh, "out of memory"); | |
1124 | return; | |
1125 | } | |
1126 | error = mb_cache_entry_insert(ce, bh->b_bdev, bh->b_blocknr, &hash); | |
1127 | if (error) { | |
1128 | mb_cache_entry_free(ce); | |
1129 | if (error == -EBUSY) { | |
1130 | ea_bdebug(bh, "already in cache"); | |
1131 | error = 0; | |
1132 | } | |
1133 | } else { | |
1134 | ea_bdebug(bh, "inserting [%x]", (int)hash); | |
1135 | mb_cache_entry_release(ce); | |
1136 | } | |
1137 | } | |
1138 | ||
1139 | /* | |
617ba13b | 1140 | * ext4_xattr_cmp() |
ac27a0ec DK |
1141 | * |
1142 | * Compare two extended attribute blocks for equality. | |
1143 | * | |
1144 | * Returns 0 if the blocks are equal, 1 if they differ, and | |
1145 | * a negative error number on errors. | |
1146 | */ | |
1147 | static int | |
617ba13b MC |
1148 | ext4_xattr_cmp(struct ext4_xattr_header *header1, |
1149 | struct ext4_xattr_header *header2) | |
ac27a0ec | 1150 | { |
617ba13b | 1151 | struct ext4_xattr_entry *entry1, *entry2; |
ac27a0ec DK |
1152 | |
1153 | entry1 = ENTRY(header1+1); | |
1154 | entry2 = ENTRY(header2+1); | |
1155 | while (!IS_LAST_ENTRY(entry1)) { | |
1156 | if (IS_LAST_ENTRY(entry2)) | |
1157 | return 1; | |
1158 | if (entry1->e_hash != entry2->e_hash || | |
1159 | entry1->e_name_index != entry2->e_name_index || | |
1160 | entry1->e_name_len != entry2->e_name_len || | |
1161 | entry1->e_value_size != entry2->e_value_size || | |
1162 | memcmp(entry1->e_name, entry2->e_name, entry1->e_name_len)) | |
1163 | return 1; | |
1164 | if (entry1->e_value_block != 0 || entry2->e_value_block != 0) | |
1165 | return -EIO; | |
1166 | if (memcmp((char *)header1 + le16_to_cpu(entry1->e_value_offs), | |
1167 | (char *)header2 + le16_to_cpu(entry2->e_value_offs), | |
1168 | le32_to_cpu(entry1->e_value_size))) | |
1169 | return 1; | |
1170 | ||
617ba13b MC |
1171 | entry1 = EXT4_XATTR_NEXT(entry1); |
1172 | entry2 = EXT4_XATTR_NEXT(entry2); | |
ac27a0ec DK |
1173 | } |
1174 | if (!IS_LAST_ENTRY(entry2)) | |
1175 | return 1; | |
1176 | return 0; | |
1177 | } | |
1178 | ||
1179 | /* | |
617ba13b | 1180 | * ext4_xattr_cache_find() |
ac27a0ec DK |
1181 | * |
1182 | * Find an identical extended attribute block. | |
1183 | * | |
1184 | * Returns a pointer to the block found, or NULL if such a block was | |
1185 | * not found or an error occurred. | |
1186 | */ | |
1187 | static struct buffer_head * | |
617ba13b | 1188 | ext4_xattr_cache_find(struct inode *inode, struct ext4_xattr_header *header, |
ac27a0ec DK |
1189 | struct mb_cache_entry **pce) |
1190 | { | |
1191 | __u32 hash = le32_to_cpu(header->h_hash); | |
1192 | struct mb_cache_entry *ce; | |
1193 | ||
1194 | if (!header->h_hash) | |
1195 | return NULL; /* never share */ | |
1196 | ea_idebug(inode, "looking for cached blocks [%x]", (int)hash); | |
1197 | again: | |
617ba13b | 1198 | ce = mb_cache_entry_find_first(ext4_xattr_cache, 0, |
ac27a0ec DK |
1199 | inode->i_sb->s_bdev, hash); |
1200 | while (ce) { | |
1201 | struct buffer_head *bh; | |
1202 | ||
1203 | if (IS_ERR(ce)) { | |
1204 | if (PTR_ERR(ce) == -EAGAIN) | |
1205 | goto again; | |
1206 | break; | |
1207 | } | |
1208 | bh = sb_bread(inode->i_sb, ce->e_block); | |
1209 | if (!bh) { | |
617ba13b | 1210 | ext4_error(inode->i_sb, __FUNCTION__, |
ac27a0ec DK |
1211 | "inode %lu: block %lu read error", |
1212 | inode->i_ino, (unsigned long) ce->e_block); | |
1213 | } else if (le32_to_cpu(BHDR(bh)->h_refcount) >= | |
617ba13b | 1214 | EXT4_XATTR_REFCOUNT_MAX) { |
ac27a0ec DK |
1215 | ea_idebug(inode, "block %lu refcount %d>=%d", |
1216 | (unsigned long) ce->e_block, | |
1217 | le32_to_cpu(BHDR(bh)->h_refcount), | |
617ba13b MC |
1218 | EXT4_XATTR_REFCOUNT_MAX); |
1219 | } else if (ext4_xattr_cmp(header, BHDR(bh)) == 0) { | |
ac27a0ec DK |
1220 | *pce = ce; |
1221 | return bh; | |
1222 | } | |
1223 | brelse(bh); | |
1224 | ce = mb_cache_entry_find_next(ce, 0, inode->i_sb->s_bdev, hash); | |
1225 | } | |
1226 | return NULL; | |
1227 | } | |
1228 | ||
1229 | #define NAME_HASH_SHIFT 5 | |
1230 | #define VALUE_HASH_SHIFT 16 | |
1231 | ||
1232 | /* | |
617ba13b | 1233 | * ext4_xattr_hash_entry() |
ac27a0ec DK |
1234 | * |
1235 | * Compute the hash of an extended attribute. | |
1236 | */ | |
617ba13b MC |
1237 | static inline void ext4_xattr_hash_entry(struct ext4_xattr_header *header, |
1238 | struct ext4_xattr_entry *entry) | |
ac27a0ec DK |
1239 | { |
1240 | __u32 hash = 0; | |
1241 | char *name = entry->e_name; | |
1242 | int n; | |
1243 | ||
1244 | for (n=0; n < entry->e_name_len; n++) { | |
1245 | hash = (hash << NAME_HASH_SHIFT) ^ | |
1246 | (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^ | |
1247 | *name++; | |
1248 | } | |
1249 | ||
1250 | if (entry->e_value_block == 0 && entry->e_value_size != 0) { | |
1251 | __le32 *value = (__le32 *)((char *)header + | |
1252 | le16_to_cpu(entry->e_value_offs)); | |
1253 | for (n = (le32_to_cpu(entry->e_value_size) + | |
617ba13b | 1254 | EXT4_XATTR_ROUND) >> EXT4_XATTR_PAD_BITS; n; n--) { |
ac27a0ec DK |
1255 | hash = (hash << VALUE_HASH_SHIFT) ^ |
1256 | (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^ | |
1257 | le32_to_cpu(*value++); | |
1258 | } | |
1259 | } | |
1260 | entry->e_hash = cpu_to_le32(hash); | |
1261 | } | |
1262 | ||
1263 | #undef NAME_HASH_SHIFT | |
1264 | #undef VALUE_HASH_SHIFT | |
1265 | ||
1266 | #define BLOCK_HASH_SHIFT 16 | |
1267 | ||
1268 | /* | |
617ba13b | 1269 | * ext4_xattr_rehash() |
ac27a0ec DK |
1270 | * |
1271 | * Re-compute the extended attribute hash value after an entry has changed. | |
1272 | */ | |
617ba13b MC |
1273 | static void ext4_xattr_rehash(struct ext4_xattr_header *header, |
1274 | struct ext4_xattr_entry *entry) | |
ac27a0ec | 1275 | { |
617ba13b | 1276 | struct ext4_xattr_entry *here; |
ac27a0ec DK |
1277 | __u32 hash = 0; |
1278 | ||
617ba13b | 1279 | ext4_xattr_hash_entry(header, entry); |
ac27a0ec DK |
1280 | here = ENTRY(header+1); |
1281 | while (!IS_LAST_ENTRY(here)) { | |
1282 | if (!here->e_hash) { | |
1283 | /* Block is not shared if an entry's hash value == 0 */ | |
1284 | hash = 0; | |
1285 | break; | |
1286 | } | |
1287 | hash = (hash << BLOCK_HASH_SHIFT) ^ | |
1288 | (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^ | |
1289 | le32_to_cpu(here->e_hash); | |
617ba13b | 1290 | here = EXT4_XATTR_NEXT(here); |
ac27a0ec DK |
1291 | } |
1292 | header->h_hash = cpu_to_le32(hash); | |
1293 | } | |
1294 | ||
1295 | #undef BLOCK_HASH_SHIFT | |
1296 | ||
1297 | int __init | |
617ba13b | 1298 | init_ext4_xattr(void) |
ac27a0ec | 1299 | { |
617ba13b | 1300 | ext4_xattr_cache = mb_cache_create("ext4_xattr", NULL, |
ac27a0ec DK |
1301 | sizeof(struct mb_cache_entry) + |
1302 | sizeof(((struct mb_cache_entry *) 0)->e_indexes[0]), 1, 6); | |
617ba13b | 1303 | if (!ext4_xattr_cache) |
ac27a0ec DK |
1304 | return -ENOMEM; |
1305 | return 0; | |
1306 | } | |
1307 | ||
1308 | void | |
617ba13b | 1309 | exit_ext4_xattr(void) |
ac27a0ec | 1310 | { |
617ba13b MC |
1311 | if (ext4_xattr_cache) |
1312 | mb_cache_destroy(ext4_xattr_cache); | |
1313 | ext4_xattr_cache = NULL; | |
ac27a0ec | 1314 | } |