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> | |
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 *); | |
d3a95d47 MC |
95 | static int ext4_xattr_list(struct inode *inode, char *buffer, |
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 | { |
617ba13b | 143 | return ext4_xattr_list(dentry->d_inode, 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)) { |
46e665e9 | 230 | bad_block: ext4_error(inode->i_sb, __func__, |
2ae02107 | 231 | "inode %lu: bad block %llu", inode->i_ino, |
617ba13b | 232 | EXT4_I(inode)->i_file_acl); |
ac27a0ec DK |
233 | error = -EIO; |
234 | goto cleanup; | |
235 | } | |
617ba13b | 236 | ext4_xattr_cache_insert(bh); |
ac27a0ec | 237 | entry = BFIRST(bh); |
617ba13b | 238 | error = ext4_xattr_find_entry(&entry, name_index, name, bh->b_size, 1); |
ac27a0ec DK |
239 | if (error == -EIO) |
240 | goto bad_block; | |
241 | if (error) | |
242 | goto cleanup; | |
243 | size = le32_to_cpu(entry->e_value_size); | |
244 | if (buffer) { | |
245 | error = -ERANGE; | |
246 | if (size > buffer_size) | |
247 | goto cleanup; | |
248 | memcpy(buffer, bh->b_data + le16_to_cpu(entry->e_value_offs), | |
249 | size); | |
250 | } | |
251 | error = size; | |
252 | ||
253 | cleanup: | |
254 | brelse(bh); | |
255 | return error; | |
256 | } | |
257 | ||
258 | static int | |
617ba13b | 259 | ext4_xattr_ibody_get(struct inode *inode, int name_index, const char *name, |
ac27a0ec DK |
260 | void *buffer, size_t buffer_size) |
261 | { | |
617ba13b MC |
262 | struct ext4_xattr_ibody_header *header; |
263 | struct ext4_xattr_entry *entry; | |
264 | struct ext4_inode *raw_inode; | |
265 | struct ext4_iloc iloc; | |
ac27a0ec DK |
266 | size_t size; |
267 | void *end; | |
268 | int error; | |
269 | ||
617ba13b | 270 | if (!(EXT4_I(inode)->i_state & EXT4_STATE_XATTR)) |
ac27a0ec | 271 | return -ENODATA; |
617ba13b | 272 | error = ext4_get_inode_loc(inode, &iloc); |
ac27a0ec DK |
273 | if (error) |
274 | return error; | |
617ba13b | 275 | raw_inode = ext4_raw_inode(&iloc); |
ac27a0ec DK |
276 | header = IHDR(inode, raw_inode); |
277 | entry = IFIRST(header); | |
617ba13b MC |
278 | end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; |
279 | error = ext4_xattr_check_names(entry, end); | |
ac27a0ec DK |
280 | if (error) |
281 | goto cleanup; | |
617ba13b | 282 | error = ext4_xattr_find_entry(&entry, name_index, name, |
ac27a0ec DK |
283 | end - (void *)entry, 0); |
284 | if (error) | |
285 | goto cleanup; | |
286 | size = le32_to_cpu(entry->e_value_size); | |
287 | if (buffer) { | |
288 | error = -ERANGE; | |
289 | if (size > buffer_size) | |
290 | goto cleanup; | |
291 | memcpy(buffer, (void *)IFIRST(header) + | |
292 | le16_to_cpu(entry->e_value_offs), size); | |
293 | } | |
294 | error = size; | |
295 | ||
296 | cleanup: | |
297 | brelse(iloc.bh); | |
298 | return error; | |
299 | } | |
300 | ||
301 | /* | |
617ba13b | 302 | * ext4_xattr_get() |
ac27a0ec DK |
303 | * |
304 | * Copy an extended attribute into the buffer | |
305 | * provided, or compute the buffer size required. | |
306 | * Buffer is NULL to compute the size of the buffer required. | |
307 | * | |
308 | * Returns a negative error number on failure, or the number of bytes | |
309 | * used / required on success. | |
310 | */ | |
311 | int | |
617ba13b | 312 | ext4_xattr_get(struct inode *inode, int name_index, const char *name, |
ac27a0ec DK |
313 | void *buffer, size_t buffer_size) |
314 | { | |
315 | int error; | |
316 | ||
617ba13b MC |
317 | down_read(&EXT4_I(inode)->xattr_sem); |
318 | error = ext4_xattr_ibody_get(inode, name_index, name, buffer, | |
ac27a0ec DK |
319 | buffer_size); |
320 | if (error == -ENODATA) | |
617ba13b | 321 | error = ext4_xattr_block_get(inode, name_index, name, buffer, |
ac27a0ec | 322 | buffer_size); |
617ba13b | 323 | up_read(&EXT4_I(inode)->xattr_sem); |
ac27a0ec DK |
324 | return error; |
325 | } | |
326 | ||
327 | static int | |
617ba13b | 328 | ext4_xattr_list_entries(struct inode *inode, struct ext4_xattr_entry *entry, |
ac27a0ec DK |
329 | char *buffer, size_t buffer_size) |
330 | { | |
331 | size_t rest = buffer_size; | |
332 | ||
617ba13b | 333 | for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) { |
ac27a0ec | 334 | struct xattr_handler *handler = |
617ba13b | 335 | ext4_xattr_handler(entry->e_name_index); |
ac27a0ec DK |
336 | |
337 | if (handler) { | |
338 | size_t size = handler->list(inode, buffer, rest, | |
339 | entry->e_name, | |
340 | entry->e_name_len); | |
341 | if (buffer) { | |
342 | if (size > rest) | |
343 | return -ERANGE; | |
344 | buffer += size; | |
345 | } | |
346 | rest -= size; | |
347 | } | |
348 | } | |
349 | return buffer_size - rest; | |
350 | } | |
351 | ||
352 | static int | |
617ba13b | 353 | ext4_xattr_block_list(struct inode *inode, char *buffer, size_t buffer_size) |
ac27a0ec DK |
354 | { |
355 | struct buffer_head *bh = NULL; | |
356 | int error; | |
357 | ||
358 | ea_idebug(inode, "buffer=%p, buffer_size=%ld", | |
359 | buffer, (long)buffer_size); | |
360 | ||
361 | error = 0; | |
617ba13b | 362 | if (!EXT4_I(inode)->i_file_acl) |
ac27a0ec | 363 | goto cleanup; |
617ba13b MC |
364 | ea_idebug(inode, "reading block %u", EXT4_I(inode)->i_file_acl); |
365 | bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl); | |
ac27a0ec DK |
366 | error = -EIO; |
367 | if (!bh) | |
368 | goto cleanup; | |
369 | ea_bdebug(bh, "b_count=%d, refcount=%d", | |
370 | atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount)); | |
617ba13b | 371 | if (ext4_xattr_check_block(bh)) { |
46e665e9 | 372 | ext4_error(inode->i_sb, __func__, |
2ae02107 | 373 | "inode %lu: bad block %llu", inode->i_ino, |
617ba13b | 374 | EXT4_I(inode)->i_file_acl); |
ac27a0ec DK |
375 | error = -EIO; |
376 | goto cleanup; | |
377 | } | |
617ba13b MC |
378 | ext4_xattr_cache_insert(bh); |
379 | error = ext4_xattr_list_entries(inode, BFIRST(bh), buffer, buffer_size); | |
ac27a0ec DK |
380 | |
381 | cleanup: | |
382 | brelse(bh); | |
383 | ||
384 | return error; | |
385 | } | |
386 | ||
387 | static int | |
617ba13b | 388 | ext4_xattr_ibody_list(struct inode *inode, char *buffer, size_t buffer_size) |
ac27a0ec | 389 | { |
617ba13b MC |
390 | struct ext4_xattr_ibody_header *header; |
391 | struct ext4_inode *raw_inode; | |
392 | struct ext4_iloc iloc; | |
ac27a0ec DK |
393 | void *end; |
394 | int error; | |
395 | ||
617ba13b | 396 | if (!(EXT4_I(inode)->i_state & EXT4_STATE_XATTR)) |
ac27a0ec | 397 | return 0; |
617ba13b | 398 | error = ext4_get_inode_loc(inode, &iloc); |
ac27a0ec DK |
399 | if (error) |
400 | return error; | |
617ba13b | 401 | raw_inode = ext4_raw_inode(&iloc); |
ac27a0ec | 402 | header = IHDR(inode, raw_inode); |
617ba13b MC |
403 | end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; |
404 | error = ext4_xattr_check_names(IFIRST(header), end); | |
ac27a0ec DK |
405 | if (error) |
406 | goto cleanup; | |
617ba13b | 407 | error = ext4_xattr_list_entries(inode, IFIRST(header), |
ac27a0ec DK |
408 | buffer, buffer_size); |
409 | ||
410 | cleanup: | |
411 | brelse(iloc.bh); | |
412 | return error; | |
413 | } | |
414 | ||
415 | /* | |
617ba13b | 416 | * ext4_xattr_list() |
ac27a0ec DK |
417 | * |
418 | * Copy a list of attribute names into the buffer | |
419 | * provided, or compute the buffer size required. | |
420 | * Buffer is NULL to compute the size of the buffer required. | |
421 | * | |
422 | * Returns a negative error number on failure, or the number of bytes | |
423 | * used / required on success. | |
424 | */ | |
d3a95d47 | 425 | static int |
617ba13b | 426 | ext4_xattr_list(struct inode *inode, char *buffer, size_t buffer_size) |
ac27a0ec DK |
427 | { |
428 | int i_error, b_error; | |
429 | ||
617ba13b MC |
430 | down_read(&EXT4_I(inode)->xattr_sem); |
431 | i_error = ext4_xattr_ibody_list(inode, buffer, buffer_size); | |
ac27a0ec DK |
432 | if (i_error < 0) { |
433 | b_error = 0; | |
434 | } else { | |
435 | if (buffer) { | |
436 | buffer += i_error; | |
437 | buffer_size -= i_error; | |
438 | } | |
617ba13b | 439 | b_error = ext4_xattr_block_list(inode, buffer, buffer_size); |
ac27a0ec DK |
440 | if (b_error < 0) |
441 | i_error = 0; | |
442 | } | |
617ba13b | 443 | up_read(&EXT4_I(inode)->xattr_sem); |
ac27a0ec DK |
444 | return i_error + b_error; |
445 | } | |
446 | ||
447 | /* | |
617ba13b | 448 | * If the EXT4_FEATURE_COMPAT_EXT_ATTR feature of this file system is |
ac27a0ec DK |
449 | * not set, set it. |
450 | */ | |
617ba13b | 451 | static void ext4_xattr_update_super_block(handle_t *handle, |
ac27a0ec DK |
452 | struct super_block *sb) |
453 | { | |
617ba13b | 454 | if (EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_EXT_ATTR)) |
ac27a0ec DK |
455 | return; |
456 | ||
617ba13b | 457 | if (ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh) == 0) { |
ed2908f3 | 458 | EXT4_SET_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_EXT_ATTR); |
ac27a0ec | 459 | sb->s_dirt = 1; |
0390131b | 460 | ext4_handle_dirty_metadata(handle, NULL, EXT4_SB(sb)->s_sbh); |
ac27a0ec | 461 | } |
ac27a0ec DK |
462 | } |
463 | ||
464 | /* | |
465 | * Release the xattr block BH: If the reference count is > 1, decrement | |
466 | * it; otherwise free the block. | |
467 | */ | |
468 | static void | |
617ba13b | 469 | ext4_xattr_release_block(handle_t *handle, struct inode *inode, |
ac27a0ec DK |
470 | struct buffer_head *bh) |
471 | { | |
472 | struct mb_cache_entry *ce = NULL; | |
8a2bfdcb | 473 | int error = 0; |
ac27a0ec | 474 | |
617ba13b | 475 | ce = mb_cache_entry_get(ext4_xattr_cache, bh->b_bdev, bh->b_blocknr); |
8a2bfdcb MC |
476 | error = ext4_journal_get_write_access(handle, bh); |
477 | if (error) | |
478 | goto out; | |
479 | ||
480 | lock_buffer(bh); | |
ac27a0ec DK |
481 | if (BHDR(bh)->h_refcount == cpu_to_le32(1)) { |
482 | ea_bdebug(bh, "refcount now=0; freeing"); | |
483 | if (ce) | |
484 | mb_cache_entry_free(ce); | |
c9de560d | 485 | ext4_free_blocks(handle, inode, bh->b_blocknr, 1, 1); |
ac27a0ec | 486 | get_bh(bh); |
617ba13b | 487 | ext4_forget(handle, 1, inode, bh, bh->b_blocknr); |
ac27a0ec | 488 | } else { |
e8546d06 | 489 | le32_add_cpu(&BHDR(bh)->h_refcount, -1); |
0390131b | 490 | error = ext4_handle_dirty_metadata(handle, inode, bh); |
8a2bfdcb | 491 | if (IS_SYNC(inode)) |
0390131b | 492 | ext4_handle_sync(handle); |
a269eb18 | 493 | vfs_dq_free_block(inode, 1); |
8a2bfdcb MC |
494 | ea_bdebug(bh, "refcount now=%d; releasing", |
495 | le32_to_cpu(BHDR(bh)->h_refcount)); | |
ac27a0ec DK |
496 | if (ce) |
497 | mb_cache_entry_release(ce); | |
498 | } | |
8a2bfdcb MC |
499 | unlock_buffer(bh); |
500 | out: | |
501 | ext4_std_error(inode->i_sb, error); | |
502 | return; | |
ac27a0ec DK |
503 | } |
504 | ||
6dd4ee7c KS |
505 | /* |
506 | * Find the available free space for EAs. This also returns the total number of | |
507 | * bytes used by EA entries. | |
508 | */ | |
509 | static size_t ext4_xattr_free_space(struct ext4_xattr_entry *last, | |
510 | size_t *min_offs, void *base, int *total) | |
511 | { | |
512 | for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) { | |
513 | *total += EXT4_XATTR_LEN(last->e_name_len); | |
514 | if (!last->e_value_block && last->e_value_size) { | |
515 | size_t offs = le16_to_cpu(last->e_value_offs); | |
516 | if (offs < *min_offs) | |
517 | *min_offs = offs; | |
518 | } | |
519 | } | |
520 | return (*min_offs - ((void *)last - base) - sizeof(__u32)); | |
521 | } | |
522 | ||
617ba13b | 523 | struct ext4_xattr_info { |
ac27a0ec DK |
524 | int name_index; |
525 | const char *name; | |
526 | const void *value; | |
527 | size_t value_len; | |
528 | }; | |
529 | ||
617ba13b MC |
530 | struct ext4_xattr_search { |
531 | struct ext4_xattr_entry *first; | |
ac27a0ec DK |
532 | void *base; |
533 | void *end; | |
617ba13b | 534 | struct ext4_xattr_entry *here; |
ac27a0ec DK |
535 | int not_found; |
536 | }; | |
537 | ||
538 | static int | |
617ba13b | 539 | ext4_xattr_set_entry(struct ext4_xattr_info *i, struct ext4_xattr_search *s) |
ac27a0ec | 540 | { |
617ba13b | 541 | struct ext4_xattr_entry *last; |
ac27a0ec DK |
542 | size_t free, min_offs = s->end - s->base, name_len = strlen(i->name); |
543 | ||
544 | /* Compute min_offs and last. */ | |
545 | last = s->first; | |
617ba13b | 546 | for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) { |
ac27a0ec DK |
547 | if (!last->e_value_block && last->e_value_size) { |
548 | size_t offs = le16_to_cpu(last->e_value_offs); | |
549 | if (offs < min_offs) | |
550 | min_offs = offs; | |
551 | } | |
552 | } | |
553 | free = min_offs - ((void *)last - s->base) - sizeof(__u32); | |
554 | if (!s->not_found) { | |
555 | if (!s->here->e_value_block && s->here->e_value_size) { | |
556 | size_t size = le32_to_cpu(s->here->e_value_size); | |
617ba13b | 557 | free += EXT4_XATTR_SIZE(size); |
ac27a0ec | 558 | } |
617ba13b | 559 | free += EXT4_XATTR_LEN(name_len); |
ac27a0ec DK |
560 | } |
561 | if (i->value) { | |
617ba13b MC |
562 | if (free < EXT4_XATTR_SIZE(i->value_len) || |
563 | free < EXT4_XATTR_LEN(name_len) + | |
564 | EXT4_XATTR_SIZE(i->value_len)) | |
ac27a0ec DK |
565 | return -ENOSPC; |
566 | } | |
567 | ||
568 | if (i->value && s->not_found) { | |
569 | /* Insert the new name. */ | |
617ba13b | 570 | size_t size = EXT4_XATTR_LEN(name_len); |
ac27a0ec DK |
571 | size_t rest = (void *)last - (void *)s->here + sizeof(__u32); |
572 | memmove((void *)s->here + size, s->here, rest); | |
573 | memset(s->here, 0, size); | |
574 | s->here->e_name_index = i->name_index; | |
575 | s->here->e_name_len = name_len; | |
576 | memcpy(s->here->e_name, i->name, name_len); | |
577 | } else { | |
578 | if (!s->here->e_value_block && s->here->e_value_size) { | |
579 | void *first_val = s->base + min_offs; | |
580 | size_t offs = le16_to_cpu(s->here->e_value_offs); | |
581 | void *val = s->base + offs; | |
617ba13b | 582 | size_t size = EXT4_XATTR_SIZE( |
ac27a0ec DK |
583 | le32_to_cpu(s->here->e_value_size)); |
584 | ||
617ba13b | 585 | if (i->value && size == EXT4_XATTR_SIZE(i->value_len)) { |
ac27a0ec DK |
586 | /* The old and the new value have the same |
587 | size. Just replace. */ | |
588 | s->here->e_value_size = | |
589 | cpu_to_le32(i->value_len); | |
617ba13b MC |
590 | memset(val + size - EXT4_XATTR_PAD, 0, |
591 | EXT4_XATTR_PAD); /* Clear pad bytes. */ | |
ac27a0ec DK |
592 | memcpy(val, i->value, i->value_len); |
593 | return 0; | |
594 | } | |
595 | ||
596 | /* Remove the old value. */ | |
597 | memmove(first_val + size, first_val, val - first_val); | |
598 | memset(first_val, 0, size); | |
599 | s->here->e_value_size = 0; | |
600 | s->here->e_value_offs = 0; | |
601 | min_offs += size; | |
602 | ||
603 | /* Adjust all value offsets. */ | |
604 | last = s->first; | |
605 | while (!IS_LAST_ENTRY(last)) { | |
606 | size_t o = le16_to_cpu(last->e_value_offs); | |
607 | if (!last->e_value_block && | |
608 | last->e_value_size && o < offs) | |
609 | last->e_value_offs = | |
610 | cpu_to_le16(o + size); | |
617ba13b | 611 | last = EXT4_XATTR_NEXT(last); |
ac27a0ec DK |
612 | } |
613 | } | |
614 | if (!i->value) { | |
615 | /* Remove the old name. */ | |
617ba13b | 616 | size_t size = EXT4_XATTR_LEN(name_len); |
ac27a0ec DK |
617 | last = ENTRY((void *)last - size); |
618 | memmove(s->here, (void *)s->here + size, | |
619 | (void *)last - (void *)s->here + sizeof(__u32)); | |
620 | memset(last, 0, size); | |
621 | } | |
622 | } | |
623 | ||
624 | if (i->value) { | |
625 | /* Insert the new value. */ | |
626 | s->here->e_value_size = cpu_to_le32(i->value_len); | |
627 | if (i->value_len) { | |
617ba13b | 628 | size_t size = EXT4_XATTR_SIZE(i->value_len); |
ac27a0ec DK |
629 | void *val = s->base + min_offs - size; |
630 | s->here->e_value_offs = cpu_to_le16(min_offs - size); | |
617ba13b MC |
631 | memset(val + size - EXT4_XATTR_PAD, 0, |
632 | EXT4_XATTR_PAD); /* Clear the pad bytes. */ | |
ac27a0ec DK |
633 | memcpy(val, i->value, i->value_len); |
634 | } | |
635 | } | |
636 | return 0; | |
637 | } | |
638 | ||
617ba13b MC |
639 | struct ext4_xattr_block_find { |
640 | struct ext4_xattr_search s; | |
ac27a0ec DK |
641 | struct buffer_head *bh; |
642 | }; | |
643 | ||
644 | static int | |
617ba13b MC |
645 | ext4_xattr_block_find(struct inode *inode, struct ext4_xattr_info *i, |
646 | struct ext4_xattr_block_find *bs) | |
ac27a0ec DK |
647 | { |
648 | struct super_block *sb = inode->i_sb; | |
649 | int error; | |
650 | ||
651 | ea_idebug(inode, "name=%d.%s, value=%p, value_len=%ld", | |
652 | i->name_index, i->name, i->value, (long)i->value_len); | |
653 | ||
617ba13b | 654 | if (EXT4_I(inode)->i_file_acl) { |
ac27a0ec | 655 | /* The inode already has an extended attribute block. */ |
617ba13b | 656 | bs->bh = sb_bread(sb, EXT4_I(inode)->i_file_acl); |
ac27a0ec DK |
657 | error = -EIO; |
658 | if (!bs->bh) | |
659 | goto cleanup; | |
660 | ea_bdebug(bs->bh, "b_count=%d, refcount=%d", | |
661 | atomic_read(&(bs->bh->b_count)), | |
662 | le32_to_cpu(BHDR(bs->bh)->h_refcount)); | |
617ba13b | 663 | if (ext4_xattr_check_block(bs->bh)) { |
46e665e9 | 664 | ext4_error(sb, __func__, |
2ae02107 | 665 | "inode %lu: bad block %llu", inode->i_ino, |
617ba13b | 666 | EXT4_I(inode)->i_file_acl); |
ac27a0ec DK |
667 | error = -EIO; |
668 | goto cleanup; | |
669 | } | |
670 | /* Find the named attribute. */ | |
671 | bs->s.base = BHDR(bs->bh); | |
672 | bs->s.first = BFIRST(bs->bh); | |
673 | bs->s.end = bs->bh->b_data + bs->bh->b_size; | |
674 | bs->s.here = bs->s.first; | |
617ba13b | 675 | error = ext4_xattr_find_entry(&bs->s.here, i->name_index, |
ac27a0ec DK |
676 | i->name, bs->bh->b_size, 1); |
677 | if (error && error != -ENODATA) | |
678 | goto cleanup; | |
679 | bs->s.not_found = error; | |
680 | } | |
681 | error = 0; | |
682 | ||
683 | cleanup: | |
684 | return error; | |
685 | } | |
686 | ||
687 | static int | |
617ba13b MC |
688 | ext4_xattr_block_set(handle_t *handle, struct inode *inode, |
689 | struct ext4_xattr_info *i, | |
690 | struct ext4_xattr_block_find *bs) | |
ac27a0ec DK |
691 | { |
692 | struct super_block *sb = inode->i_sb; | |
693 | struct buffer_head *new_bh = NULL; | |
617ba13b | 694 | struct ext4_xattr_search *s = &bs->s; |
ac27a0ec | 695 | struct mb_cache_entry *ce = NULL; |
8a2bfdcb | 696 | int error = 0; |
ac27a0ec | 697 | |
617ba13b | 698 | #define header(x) ((struct ext4_xattr_header *)(x)) |
ac27a0ec DK |
699 | |
700 | if (i->value && i->value_len > sb->s_blocksize) | |
701 | return -ENOSPC; | |
702 | if (s->base) { | |
617ba13b | 703 | ce = mb_cache_entry_get(ext4_xattr_cache, bs->bh->b_bdev, |
ac27a0ec | 704 | bs->bh->b_blocknr); |
8a2bfdcb MC |
705 | error = ext4_journal_get_write_access(handle, bs->bh); |
706 | if (error) | |
707 | goto cleanup; | |
708 | lock_buffer(bs->bh); | |
709 | ||
ac27a0ec DK |
710 | if (header(s->base)->h_refcount == cpu_to_le32(1)) { |
711 | if (ce) { | |
712 | mb_cache_entry_free(ce); | |
713 | ce = NULL; | |
714 | } | |
715 | ea_bdebug(bs->bh, "modifying in-place"); | |
617ba13b | 716 | error = ext4_xattr_set_entry(i, s); |
ac27a0ec DK |
717 | if (!error) { |
718 | if (!IS_LAST_ENTRY(s->first)) | |
617ba13b | 719 | ext4_xattr_rehash(header(s->base), |
ac27a0ec | 720 | s->here); |
617ba13b | 721 | ext4_xattr_cache_insert(bs->bh); |
ac27a0ec DK |
722 | } |
723 | unlock_buffer(bs->bh); | |
724 | if (error == -EIO) | |
725 | goto bad_block; | |
726 | if (!error) | |
0390131b FM |
727 | error = ext4_handle_dirty_metadata(handle, |
728 | inode, | |
729 | bs->bh); | |
ac27a0ec DK |
730 | if (error) |
731 | goto cleanup; | |
732 | goto inserted; | |
733 | } else { | |
734 | int offset = (char *)s->here - bs->bh->b_data; | |
735 | ||
8a2bfdcb MC |
736 | unlock_buffer(bs->bh); |
737 | jbd2_journal_release_buffer(handle, bs->bh); | |
ac27a0ec DK |
738 | if (ce) { |
739 | mb_cache_entry_release(ce); | |
740 | ce = NULL; | |
741 | } | |
742 | ea_bdebug(bs->bh, "cloning"); | |
216553c4 | 743 | s->base = kmalloc(bs->bh->b_size, GFP_NOFS); |
ac27a0ec DK |
744 | error = -ENOMEM; |
745 | if (s->base == NULL) | |
746 | goto cleanup; | |
747 | memcpy(s->base, BHDR(bs->bh), bs->bh->b_size); | |
748 | s->first = ENTRY(header(s->base)+1); | |
749 | header(s->base)->h_refcount = cpu_to_le32(1); | |
750 | s->here = ENTRY(s->base + offset); | |
751 | s->end = s->base + bs->bh->b_size; | |
752 | } | |
753 | } else { | |
754 | /* Allocate a buffer where we construct the new block. */ | |
216553c4 | 755 | s->base = kzalloc(sb->s_blocksize, GFP_NOFS); |
ac27a0ec DK |
756 | /* assert(header == s->base) */ |
757 | error = -ENOMEM; | |
758 | if (s->base == NULL) | |
759 | goto cleanup; | |
617ba13b | 760 | header(s->base)->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC); |
ac27a0ec DK |
761 | header(s->base)->h_blocks = cpu_to_le32(1); |
762 | header(s->base)->h_refcount = cpu_to_le32(1); | |
763 | s->first = ENTRY(header(s->base)+1); | |
764 | s->here = ENTRY(header(s->base)+1); | |
765 | s->end = s->base + sb->s_blocksize; | |
766 | } | |
767 | ||
617ba13b | 768 | error = ext4_xattr_set_entry(i, s); |
ac27a0ec DK |
769 | if (error == -EIO) |
770 | goto bad_block; | |
771 | if (error) | |
772 | goto cleanup; | |
773 | if (!IS_LAST_ENTRY(s->first)) | |
617ba13b | 774 | ext4_xattr_rehash(header(s->base), s->here); |
ac27a0ec DK |
775 | |
776 | inserted: | |
777 | if (!IS_LAST_ENTRY(s->first)) { | |
617ba13b | 778 | new_bh = ext4_xattr_cache_find(inode, header(s->base), &ce); |
ac27a0ec DK |
779 | if (new_bh) { |
780 | /* We found an identical block in the cache. */ | |
781 | if (new_bh == bs->bh) | |
782 | ea_bdebug(new_bh, "keeping"); | |
783 | else { | |
784 | /* The old block is released after updating | |
785 | the inode. */ | |
786 | error = -EDQUOT; | |
a269eb18 | 787 | if (vfs_dq_alloc_block(inode, 1)) |
ac27a0ec | 788 | goto cleanup; |
617ba13b | 789 | error = ext4_journal_get_write_access(handle, |
ac27a0ec DK |
790 | new_bh); |
791 | if (error) | |
792 | goto cleanup_dquot; | |
793 | lock_buffer(new_bh); | |
e8546d06 | 794 | le32_add_cpu(&BHDR(new_bh)->h_refcount, 1); |
ac27a0ec DK |
795 | ea_bdebug(new_bh, "reusing; refcount now=%d", |
796 | le32_to_cpu(BHDR(new_bh)->h_refcount)); | |
797 | unlock_buffer(new_bh); | |
0390131b FM |
798 | error = ext4_handle_dirty_metadata(handle, |
799 | inode, | |
800 | new_bh); | |
ac27a0ec DK |
801 | if (error) |
802 | goto cleanup_dquot; | |
803 | } | |
804 | mb_cache_entry_release(ce); | |
805 | ce = NULL; | |
806 | } else if (bs->bh && s->base == bs->bh->b_data) { | |
807 | /* We were modifying this block in-place. */ | |
808 | ea_bdebug(bs->bh, "keeping this block"); | |
809 | new_bh = bs->bh; | |
810 | get_bh(new_bh); | |
811 | } else { | |
812 | /* We need to allocate a new block */ | |
d00a6d7b AM |
813 | ext4_fsblk_t goal = ext4_group_first_block_no(sb, |
814 | EXT4_I(inode)->i_block_group); | |
cfe82c85 | 815 | ext4_fsblk_t block = ext4_new_meta_blocks(handle, inode, |
97df5d15 | 816 | goal, NULL, &error); |
ac27a0ec DK |
817 | if (error) |
818 | goto cleanup; | |
819 | ea_idebug(inode, "creating block %d", block); | |
820 | ||
821 | new_bh = sb_getblk(sb, block); | |
822 | if (!new_bh) { | |
823 | getblk_failed: | |
c9de560d | 824 | ext4_free_blocks(handle, inode, block, 1, 1); |
ac27a0ec DK |
825 | error = -EIO; |
826 | goto cleanup; | |
827 | } | |
828 | lock_buffer(new_bh); | |
617ba13b | 829 | error = ext4_journal_get_create_access(handle, new_bh); |
ac27a0ec DK |
830 | if (error) { |
831 | unlock_buffer(new_bh); | |
832 | goto getblk_failed; | |
833 | } | |
834 | memcpy(new_bh->b_data, s->base, new_bh->b_size); | |
835 | set_buffer_uptodate(new_bh); | |
836 | unlock_buffer(new_bh); | |
617ba13b | 837 | ext4_xattr_cache_insert(new_bh); |
0390131b FM |
838 | error = ext4_handle_dirty_metadata(handle, |
839 | inode, new_bh); | |
ac27a0ec DK |
840 | if (error) |
841 | goto cleanup; | |
842 | } | |
843 | } | |
844 | ||
845 | /* Update the inode. */ | |
617ba13b | 846 | EXT4_I(inode)->i_file_acl = new_bh ? new_bh->b_blocknr : 0; |
ac27a0ec DK |
847 | |
848 | /* Drop the previous xattr block. */ | |
849 | if (bs->bh && bs->bh != new_bh) | |
617ba13b | 850 | ext4_xattr_release_block(handle, inode, bs->bh); |
ac27a0ec DK |
851 | error = 0; |
852 | ||
853 | cleanup: | |
854 | if (ce) | |
855 | mb_cache_entry_release(ce); | |
856 | brelse(new_bh); | |
857 | if (!(bs->bh && s->base == bs->bh->b_data)) | |
858 | kfree(s->base); | |
859 | ||
860 | return error; | |
861 | ||
862 | cleanup_dquot: | |
a269eb18 | 863 | vfs_dq_free_block(inode, 1); |
ac27a0ec DK |
864 | goto cleanup; |
865 | ||
866 | bad_block: | |
46e665e9 | 867 | ext4_error(inode->i_sb, __func__, |
2ae02107 | 868 | "inode %lu: bad block %llu", inode->i_ino, |
617ba13b | 869 | EXT4_I(inode)->i_file_acl); |
ac27a0ec DK |
870 | goto cleanup; |
871 | ||
872 | #undef header | |
873 | } | |
874 | ||
617ba13b MC |
875 | struct ext4_xattr_ibody_find { |
876 | struct ext4_xattr_search s; | |
877 | struct ext4_iloc iloc; | |
ac27a0ec DK |
878 | }; |
879 | ||
880 | static int | |
617ba13b MC |
881 | ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i, |
882 | struct ext4_xattr_ibody_find *is) | |
ac27a0ec | 883 | { |
617ba13b MC |
884 | struct ext4_xattr_ibody_header *header; |
885 | struct ext4_inode *raw_inode; | |
ac27a0ec DK |
886 | int error; |
887 | ||
617ba13b | 888 | if (EXT4_I(inode)->i_extra_isize == 0) |
ac27a0ec | 889 | return 0; |
617ba13b | 890 | raw_inode = ext4_raw_inode(&is->iloc); |
ac27a0ec DK |
891 | header = IHDR(inode, raw_inode); |
892 | is->s.base = is->s.first = IFIRST(header); | |
893 | is->s.here = is->s.first; | |
617ba13b MC |
894 | is->s.end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; |
895 | if (EXT4_I(inode)->i_state & EXT4_STATE_XATTR) { | |
896 | error = ext4_xattr_check_names(IFIRST(header), is->s.end); | |
ac27a0ec DK |
897 | if (error) |
898 | return error; | |
899 | /* Find the named attribute. */ | |
617ba13b | 900 | error = ext4_xattr_find_entry(&is->s.here, i->name_index, |
ac27a0ec DK |
901 | i->name, is->s.end - |
902 | (void *)is->s.base, 0); | |
903 | if (error && error != -ENODATA) | |
904 | return error; | |
905 | is->s.not_found = error; | |
906 | } | |
907 | return 0; | |
908 | } | |
909 | ||
910 | static int | |
617ba13b MC |
911 | ext4_xattr_ibody_set(handle_t *handle, struct inode *inode, |
912 | struct ext4_xattr_info *i, | |
913 | struct ext4_xattr_ibody_find *is) | |
ac27a0ec | 914 | { |
617ba13b MC |
915 | struct ext4_xattr_ibody_header *header; |
916 | struct ext4_xattr_search *s = &is->s; | |
ac27a0ec DK |
917 | int error; |
918 | ||
617ba13b | 919 | if (EXT4_I(inode)->i_extra_isize == 0) |
ac27a0ec | 920 | return -ENOSPC; |
617ba13b | 921 | error = ext4_xattr_set_entry(i, s); |
ac27a0ec DK |
922 | if (error) |
923 | return error; | |
617ba13b | 924 | header = IHDR(inode, ext4_raw_inode(&is->iloc)); |
ac27a0ec | 925 | if (!IS_LAST_ENTRY(s->first)) { |
617ba13b MC |
926 | header->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC); |
927 | EXT4_I(inode)->i_state |= EXT4_STATE_XATTR; | |
ac27a0ec DK |
928 | } else { |
929 | header->h_magic = cpu_to_le32(0); | |
617ba13b | 930 | EXT4_I(inode)->i_state &= ~EXT4_STATE_XATTR; |
ac27a0ec DK |
931 | } |
932 | return 0; | |
933 | } | |
934 | ||
935 | /* | |
617ba13b | 936 | * ext4_xattr_set_handle() |
ac27a0ec DK |
937 | * |
938 | * Create, replace or remove an extended attribute for this inode. Buffer | |
939 | * is NULL to remove an existing extended attribute, and non-NULL to | |
940 | * either replace an existing extended attribute, or create a new extended | |
941 | * attribute. The flags XATTR_REPLACE and XATTR_CREATE | |
942 | * specify that an extended attribute must exist and must not exist | |
943 | * previous to the call, respectively. | |
944 | * | |
945 | * Returns 0, or a negative error number on failure. | |
946 | */ | |
947 | int | |
617ba13b | 948 | ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index, |
ac27a0ec DK |
949 | const char *name, const void *value, size_t value_len, |
950 | int flags) | |
951 | { | |
617ba13b | 952 | struct ext4_xattr_info i = { |
ac27a0ec DK |
953 | .name_index = name_index, |
954 | .name = name, | |
955 | .value = value, | |
956 | .value_len = value_len, | |
957 | ||
958 | }; | |
617ba13b | 959 | struct ext4_xattr_ibody_find is = { |
ac27a0ec DK |
960 | .s = { .not_found = -ENODATA, }, |
961 | }; | |
617ba13b | 962 | struct ext4_xattr_block_find bs = { |
ac27a0ec DK |
963 | .s = { .not_found = -ENODATA, }, |
964 | }; | |
4d20c685 | 965 | unsigned long no_expand; |
ac27a0ec DK |
966 | int error; |
967 | ||
968 | if (!name) | |
969 | return -EINVAL; | |
970 | if (strlen(name) > 255) | |
971 | return -ERANGE; | |
617ba13b | 972 | down_write(&EXT4_I(inode)->xattr_sem); |
4d20c685 KS |
973 | no_expand = EXT4_I(inode)->i_state & EXT4_STATE_NO_EXPAND; |
974 | EXT4_I(inode)->i_state |= EXT4_STATE_NO_EXPAND; | |
975 | ||
617ba13b | 976 | error = ext4_get_inode_loc(inode, &is.iloc); |
ac27a0ec DK |
977 | if (error) |
978 | goto cleanup; | |
979 | ||
617ba13b MC |
980 | if (EXT4_I(inode)->i_state & EXT4_STATE_NEW) { |
981 | struct ext4_inode *raw_inode = ext4_raw_inode(&is.iloc); | |
982 | memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size); | |
983 | EXT4_I(inode)->i_state &= ~EXT4_STATE_NEW; | |
ac27a0ec DK |
984 | } |
985 | ||
617ba13b | 986 | error = ext4_xattr_ibody_find(inode, &i, &is); |
ac27a0ec DK |
987 | if (error) |
988 | goto cleanup; | |
989 | if (is.s.not_found) | |
617ba13b | 990 | error = ext4_xattr_block_find(inode, &i, &bs); |
ac27a0ec DK |
991 | if (error) |
992 | goto cleanup; | |
993 | if (is.s.not_found && bs.s.not_found) { | |
994 | error = -ENODATA; | |
995 | if (flags & XATTR_REPLACE) | |
996 | goto cleanup; | |
997 | error = 0; | |
998 | if (!value) | |
999 | goto cleanup; | |
1000 | } else { | |
1001 | error = -EEXIST; | |
1002 | if (flags & XATTR_CREATE) | |
1003 | goto cleanup; | |
1004 | } | |
617ba13b | 1005 | error = ext4_journal_get_write_access(handle, is.iloc.bh); |
ac27a0ec DK |
1006 | if (error) |
1007 | goto cleanup; | |
1008 | if (!value) { | |
1009 | if (!is.s.not_found) | |
617ba13b | 1010 | error = ext4_xattr_ibody_set(handle, inode, &i, &is); |
ac27a0ec | 1011 | else if (!bs.s.not_found) |
617ba13b | 1012 | error = ext4_xattr_block_set(handle, inode, &i, &bs); |
ac27a0ec | 1013 | } else { |
617ba13b | 1014 | error = ext4_xattr_ibody_set(handle, inode, &i, &is); |
ac27a0ec DK |
1015 | if (!error && !bs.s.not_found) { |
1016 | i.value = NULL; | |
617ba13b | 1017 | error = ext4_xattr_block_set(handle, inode, &i, &bs); |
ac27a0ec | 1018 | } else if (error == -ENOSPC) { |
7e01c8e5 TY |
1019 | if (EXT4_I(inode)->i_file_acl && !bs.s.base) { |
1020 | error = ext4_xattr_block_find(inode, &i, &bs); | |
1021 | if (error) | |
1022 | goto cleanup; | |
1023 | } | |
617ba13b | 1024 | error = ext4_xattr_block_set(handle, inode, &i, &bs); |
ac27a0ec DK |
1025 | if (error) |
1026 | goto cleanup; | |
1027 | if (!is.s.not_found) { | |
1028 | i.value = NULL; | |
617ba13b | 1029 | error = ext4_xattr_ibody_set(handle, inode, &i, |
ac27a0ec DK |
1030 | &is); |
1031 | } | |
1032 | } | |
1033 | } | |
1034 | if (!error) { | |
617ba13b | 1035 | ext4_xattr_update_super_block(handle, inode->i_sb); |
ef7f3835 | 1036 | inode->i_ctime = ext4_current_time(inode); |
6dd4ee7c KS |
1037 | if (!value) |
1038 | EXT4_I(inode)->i_state &= ~EXT4_STATE_NO_EXPAND; | |
617ba13b | 1039 | error = ext4_mark_iloc_dirty(handle, inode, &is.iloc); |
ac27a0ec | 1040 | /* |
617ba13b | 1041 | * The bh is consumed by ext4_mark_iloc_dirty, even with |
ac27a0ec DK |
1042 | * error != 0. |
1043 | */ | |
1044 | is.iloc.bh = NULL; | |
1045 | if (IS_SYNC(inode)) | |
0390131b | 1046 | ext4_handle_sync(handle); |
ac27a0ec DK |
1047 | } |
1048 | ||
1049 | cleanup: | |
1050 | brelse(is.iloc.bh); | |
1051 | brelse(bs.bh); | |
4d20c685 KS |
1052 | if (no_expand == 0) |
1053 | EXT4_I(inode)->i_state &= ~EXT4_STATE_NO_EXPAND; | |
617ba13b | 1054 | up_write(&EXT4_I(inode)->xattr_sem); |
ac27a0ec DK |
1055 | return error; |
1056 | } | |
1057 | ||
1058 | /* | |
617ba13b | 1059 | * ext4_xattr_set() |
ac27a0ec | 1060 | * |
617ba13b | 1061 | * Like ext4_xattr_set_handle, but start from an inode. This extended |
ac27a0ec DK |
1062 | * attribute modification is a filesystem transaction by itself. |
1063 | * | |
1064 | * Returns 0, or a negative error number on failure. | |
1065 | */ | |
1066 | int | |
617ba13b | 1067 | ext4_xattr_set(struct inode *inode, int name_index, const char *name, |
ac27a0ec DK |
1068 | const void *value, size_t value_len, int flags) |
1069 | { | |
1070 | handle_t *handle; | |
1071 | int error, retries = 0; | |
1072 | ||
1073 | retry: | |
617ba13b | 1074 | handle = ext4_journal_start(inode, EXT4_DATA_TRANS_BLOCKS(inode->i_sb)); |
ac27a0ec DK |
1075 | if (IS_ERR(handle)) { |
1076 | error = PTR_ERR(handle); | |
1077 | } else { | |
1078 | int error2; | |
1079 | ||
617ba13b | 1080 | error = ext4_xattr_set_handle(handle, inode, name_index, name, |
ac27a0ec | 1081 | value, value_len, flags); |
617ba13b | 1082 | error2 = ext4_journal_stop(handle); |
ac27a0ec | 1083 | if (error == -ENOSPC && |
617ba13b | 1084 | ext4_should_retry_alloc(inode->i_sb, &retries)) |
ac27a0ec DK |
1085 | goto retry; |
1086 | if (error == 0) | |
1087 | error = error2; | |
1088 | } | |
1089 | ||
1090 | return error; | |
1091 | } | |
1092 | ||
6dd4ee7c KS |
1093 | /* |
1094 | * Shift the EA entries in the inode to create space for the increased | |
1095 | * i_extra_isize. | |
1096 | */ | |
1097 | static void ext4_xattr_shift_entries(struct ext4_xattr_entry *entry, | |
1098 | int value_offs_shift, void *to, | |
1099 | void *from, size_t n, int blocksize) | |
1100 | { | |
1101 | struct ext4_xattr_entry *last = entry; | |
1102 | int new_offs; | |
1103 | ||
1104 | /* Adjust the value offsets of the entries */ | |
1105 | for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) { | |
1106 | if (!last->e_value_block && last->e_value_size) { | |
1107 | new_offs = le16_to_cpu(last->e_value_offs) + | |
1108 | value_offs_shift; | |
1109 | BUG_ON(new_offs + le32_to_cpu(last->e_value_size) | |
1110 | > blocksize); | |
1111 | last->e_value_offs = cpu_to_le16(new_offs); | |
1112 | } | |
1113 | } | |
1114 | /* Shift the entries by n bytes */ | |
1115 | memmove(to, from, n); | |
1116 | } | |
1117 | ||
1118 | /* | |
1119 | * Expand an inode by new_extra_isize bytes when EAs are present. | |
1120 | * Returns 0 on success or negative error number on failure. | |
1121 | */ | |
1122 | int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize, | |
1123 | struct ext4_inode *raw_inode, handle_t *handle) | |
1124 | { | |
1125 | struct ext4_xattr_ibody_header *header; | |
1126 | struct ext4_xattr_entry *entry, *last, *first; | |
1127 | struct buffer_head *bh = NULL; | |
1128 | struct ext4_xattr_ibody_find *is = NULL; | |
1129 | struct ext4_xattr_block_find *bs = NULL; | |
1130 | char *buffer = NULL, *b_entry_name = NULL; | |
1131 | size_t min_offs, free; | |
1132 | int total_ino, total_blk; | |
1133 | void *base, *start, *end; | |
1134 | int extra_isize = 0, error = 0, tried_min_extra_isize = 0; | |
ac39849d | 1135 | int s_min_extra_isize = le16_to_cpu(EXT4_SB(inode->i_sb)->s_es->s_min_extra_isize); |
6dd4ee7c KS |
1136 | |
1137 | down_write(&EXT4_I(inode)->xattr_sem); | |
1138 | retry: | |
1139 | if (EXT4_I(inode)->i_extra_isize >= new_extra_isize) { | |
1140 | up_write(&EXT4_I(inode)->xattr_sem); | |
1141 | return 0; | |
1142 | } | |
1143 | ||
1144 | header = IHDR(inode, raw_inode); | |
1145 | entry = IFIRST(header); | |
1146 | ||
1147 | /* | |
1148 | * Check if enough free space is available in the inode to shift the | |
1149 | * entries ahead by new_extra_isize. | |
1150 | */ | |
1151 | ||
1152 | base = start = entry; | |
1153 | end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; | |
1154 | min_offs = end - base; | |
1155 | last = entry; | |
1156 | total_ino = sizeof(struct ext4_xattr_ibody_header); | |
1157 | ||
1158 | free = ext4_xattr_free_space(last, &min_offs, base, &total_ino); | |
1159 | if (free >= new_extra_isize) { | |
1160 | entry = IFIRST(header); | |
1161 | ext4_xattr_shift_entries(entry, EXT4_I(inode)->i_extra_isize | |
1162 | - new_extra_isize, (void *)raw_inode + | |
1163 | EXT4_GOOD_OLD_INODE_SIZE + new_extra_isize, | |
1164 | (void *)header, total_ino, | |
1165 | inode->i_sb->s_blocksize); | |
1166 | EXT4_I(inode)->i_extra_isize = new_extra_isize; | |
1167 | error = 0; | |
1168 | goto cleanup; | |
1169 | } | |
1170 | ||
1171 | /* | |
1172 | * Enough free space isn't available in the inode, check if | |
1173 | * EA block can hold new_extra_isize bytes. | |
1174 | */ | |
1175 | if (EXT4_I(inode)->i_file_acl) { | |
1176 | bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl); | |
1177 | error = -EIO; | |
1178 | if (!bh) | |
1179 | goto cleanup; | |
1180 | if (ext4_xattr_check_block(bh)) { | |
46e665e9 | 1181 | ext4_error(inode->i_sb, __func__, |
6dd4ee7c KS |
1182 | "inode %lu: bad block %llu", inode->i_ino, |
1183 | EXT4_I(inode)->i_file_acl); | |
1184 | error = -EIO; | |
1185 | goto cleanup; | |
1186 | } | |
1187 | base = BHDR(bh); | |
1188 | first = BFIRST(bh); | |
1189 | end = bh->b_data + bh->b_size; | |
1190 | min_offs = end - base; | |
1191 | free = ext4_xattr_free_space(first, &min_offs, base, | |
1192 | &total_blk); | |
1193 | if (free < new_extra_isize) { | |
1194 | if (!tried_min_extra_isize && s_min_extra_isize) { | |
1195 | tried_min_extra_isize++; | |
1196 | new_extra_isize = s_min_extra_isize; | |
1197 | brelse(bh); | |
1198 | goto retry; | |
1199 | } | |
1200 | error = -1; | |
1201 | goto cleanup; | |
1202 | } | |
1203 | } else { | |
1204 | free = inode->i_sb->s_blocksize; | |
1205 | } | |
1206 | ||
1207 | while (new_extra_isize > 0) { | |
1208 | size_t offs, size, entry_size; | |
1209 | struct ext4_xattr_entry *small_entry = NULL; | |
1210 | struct ext4_xattr_info i = { | |
1211 | .value = NULL, | |
1212 | .value_len = 0, | |
1213 | }; | |
1214 | unsigned int total_size; /* EA entry size + value size */ | |
1215 | unsigned int shift_bytes; /* No. of bytes to shift EAs by? */ | |
1216 | unsigned int min_total_size = ~0U; | |
1217 | ||
1218 | is = kzalloc(sizeof(struct ext4_xattr_ibody_find), GFP_NOFS); | |
1219 | bs = kzalloc(sizeof(struct ext4_xattr_block_find), GFP_NOFS); | |
1220 | if (!is || !bs) { | |
1221 | error = -ENOMEM; | |
1222 | goto cleanup; | |
1223 | } | |
1224 | ||
1225 | is->s.not_found = -ENODATA; | |
1226 | bs->s.not_found = -ENODATA; | |
1227 | is->iloc.bh = NULL; | |
1228 | bs->bh = NULL; | |
1229 | ||
1230 | last = IFIRST(header); | |
1231 | /* Find the entry best suited to be pushed into EA block */ | |
1232 | entry = NULL; | |
1233 | for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) { | |
1234 | total_size = | |
1235 | EXT4_XATTR_SIZE(le32_to_cpu(last->e_value_size)) + | |
1236 | EXT4_XATTR_LEN(last->e_name_len); | |
1237 | if (total_size <= free && total_size < min_total_size) { | |
1238 | if (total_size < new_extra_isize) { | |
1239 | small_entry = last; | |
1240 | } else { | |
1241 | entry = last; | |
1242 | min_total_size = total_size; | |
1243 | } | |
1244 | } | |
1245 | } | |
1246 | ||
1247 | if (entry == NULL) { | |
1248 | if (small_entry) { | |
1249 | entry = small_entry; | |
1250 | } else { | |
1251 | if (!tried_min_extra_isize && | |
1252 | s_min_extra_isize) { | |
1253 | tried_min_extra_isize++; | |
1254 | new_extra_isize = s_min_extra_isize; | |
1255 | goto retry; | |
1256 | } | |
1257 | error = -1; | |
1258 | goto cleanup; | |
1259 | } | |
1260 | } | |
1261 | offs = le16_to_cpu(entry->e_value_offs); | |
1262 | size = le32_to_cpu(entry->e_value_size); | |
1263 | entry_size = EXT4_XATTR_LEN(entry->e_name_len); | |
1264 | i.name_index = entry->e_name_index, | |
1265 | buffer = kmalloc(EXT4_XATTR_SIZE(size), GFP_NOFS); | |
1266 | b_entry_name = kmalloc(entry->e_name_len + 1, GFP_NOFS); | |
1267 | if (!buffer || !b_entry_name) { | |
1268 | error = -ENOMEM; | |
1269 | goto cleanup; | |
1270 | } | |
1271 | /* Save the entry name and the entry value */ | |
1272 | memcpy(buffer, (void *)IFIRST(header) + offs, | |
1273 | EXT4_XATTR_SIZE(size)); | |
1274 | memcpy(b_entry_name, entry->e_name, entry->e_name_len); | |
1275 | b_entry_name[entry->e_name_len] = '\0'; | |
1276 | i.name = b_entry_name; | |
1277 | ||
1278 | error = ext4_get_inode_loc(inode, &is->iloc); | |
1279 | if (error) | |
1280 | goto cleanup; | |
1281 | ||
1282 | error = ext4_xattr_ibody_find(inode, &i, is); | |
1283 | if (error) | |
1284 | goto cleanup; | |
1285 | ||
1286 | /* Remove the chosen entry from the inode */ | |
1287 | error = ext4_xattr_ibody_set(handle, inode, &i, is); | |
1288 | ||
1289 | entry = IFIRST(header); | |
1290 | if (entry_size + EXT4_XATTR_SIZE(size) >= new_extra_isize) | |
1291 | shift_bytes = new_extra_isize; | |
1292 | else | |
1293 | shift_bytes = entry_size + size; | |
1294 | /* Adjust the offsets and shift the remaining entries ahead */ | |
1295 | ext4_xattr_shift_entries(entry, EXT4_I(inode)->i_extra_isize - | |
1296 | shift_bytes, (void *)raw_inode + | |
1297 | EXT4_GOOD_OLD_INODE_SIZE + extra_isize + shift_bytes, | |
1298 | (void *)header, total_ino - entry_size, | |
1299 | inode->i_sb->s_blocksize); | |
1300 | ||
1301 | extra_isize += shift_bytes; | |
1302 | new_extra_isize -= shift_bytes; | |
1303 | EXT4_I(inode)->i_extra_isize = extra_isize; | |
1304 | ||
1305 | i.name = b_entry_name; | |
1306 | i.value = buffer; | |
ac39849d | 1307 | i.value_len = size; |
6dd4ee7c KS |
1308 | error = ext4_xattr_block_find(inode, &i, bs); |
1309 | if (error) | |
1310 | goto cleanup; | |
1311 | ||
1312 | /* Add entry which was removed from the inode into the block */ | |
1313 | error = ext4_xattr_block_set(handle, inode, &i, bs); | |
1314 | if (error) | |
1315 | goto cleanup; | |
1316 | kfree(b_entry_name); | |
1317 | kfree(buffer); | |
1318 | brelse(is->iloc.bh); | |
1319 | kfree(is); | |
1320 | kfree(bs); | |
1321 | } | |
1322 | brelse(bh); | |
1323 | up_write(&EXT4_I(inode)->xattr_sem); | |
1324 | return 0; | |
1325 | ||
1326 | cleanup: | |
1327 | kfree(b_entry_name); | |
1328 | kfree(buffer); | |
1329 | if (is) | |
1330 | brelse(is->iloc.bh); | |
1331 | kfree(is); | |
1332 | kfree(bs); | |
1333 | brelse(bh); | |
1334 | up_write(&EXT4_I(inode)->xattr_sem); | |
1335 | return error; | |
1336 | } | |
1337 | ||
1338 | ||
1339 | ||
ac27a0ec | 1340 | /* |
617ba13b | 1341 | * ext4_xattr_delete_inode() |
ac27a0ec DK |
1342 | * |
1343 | * Free extended attribute resources associated with this inode. This | |
1344 | * is called immediately before an inode is freed. We have exclusive | |
1345 | * access to the inode. | |
1346 | */ | |
1347 | void | |
617ba13b | 1348 | ext4_xattr_delete_inode(handle_t *handle, struct inode *inode) |
ac27a0ec DK |
1349 | { |
1350 | struct buffer_head *bh = NULL; | |
1351 | ||
617ba13b | 1352 | if (!EXT4_I(inode)->i_file_acl) |
ac27a0ec | 1353 | goto cleanup; |
617ba13b | 1354 | bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl); |
ac27a0ec | 1355 | if (!bh) { |
46e665e9 | 1356 | ext4_error(inode->i_sb, __func__, |
2ae02107 | 1357 | "inode %lu: block %llu read error", inode->i_ino, |
617ba13b | 1358 | EXT4_I(inode)->i_file_acl); |
ac27a0ec DK |
1359 | goto cleanup; |
1360 | } | |
617ba13b | 1361 | if (BHDR(bh)->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC) || |
ac27a0ec | 1362 | BHDR(bh)->h_blocks != cpu_to_le32(1)) { |
46e665e9 | 1363 | ext4_error(inode->i_sb, __func__, |
2ae02107 | 1364 | "inode %lu: bad block %llu", inode->i_ino, |
617ba13b | 1365 | EXT4_I(inode)->i_file_acl); |
ac27a0ec DK |
1366 | goto cleanup; |
1367 | } | |
617ba13b MC |
1368 | ext4_xattr_release_block(handle, inode, bh); |
1369 | EXT4_I(inode)->i_file_acl = 0; | |
ac27a0ec DK |
1370 | |
1371 | cleanup: | |
1372 | brelse(bh); | |
1373 | } | |
1374 | ||
1375 | /* | |
617ba13b | 1376 | * ext4_xattr_put_super() |
ac27a0ec DK |
1377 | * |
1378 | * This is called when a file system is unmounted. | |
1379 | */ | |
1380 | void | |
617ba13b | 1381 | ext4_xattr_put_super(struct super_block *sb) |
ac27a0ec DK |
1382 | { |
1383 | mb_cache_shrink(sb->s_bdev); | |
1384 | } | |
1385 | ||
1386 | /* | |
617ba13b | 1387 | * ext4_xattr_cache_insert() |
ac27a0ec DK |
1388 | * |
1389 | * Create a new entry in the extended attribute cache, and insert | |
1390 | * it unless such an entry is already in the cache. | |
1391 | * | |
1392 | * Returns 0, or a negative error number on failure. | |
1393 | */ | |
1394 | static void | |
617ba13b | 1395 | ext4_xattr_cache_insert(struct buffer_head *bh) |
ac27a0ec DK |
1396 | { |
1397 | __u32 hash = le32_to_cpu(BHDR(bh)->h_hash); | |
1398 | struct mb_cache_entry *ce; | |
1399 | int error; | |
1400 | ||
335e92e8 | 1401 | ce = mb_cache_entry_alloc(ext4_xattr_cache, GFP_NOFS); |
ac27a0ec DK |
1402 | if (!ce) { |
1403 | ea_bdebug(bh, "out of memory"); | |
1404 | return; | |
1405 | } | |
1406 | error = mb_cache_entry_insert(ce, bh->b_bdev, bh->b_blocknr, &hash); | |
1407 | if (error) { | |
1408 | mb_cache_entry_free(ce); | |
1409 | if (error == -EBUSY) { | |
1410 | ea_bdebug(bh, "already in cache"); | |
1411 | error = 0; | |
1412 | } | |
1413 | } else { | |
1414 | ea_bdebug(bh, "inserting [%x]", (int)hash); | |
1415 | mb_cache_entry_release(ce); | |
1416 | } | |
1417 | } | |
1418 | ||
1419 | /* | |
617ba13b | 1420 | * ext4_xattr_cmp() |
ac27a0ec DK |
1421 | * |
1422 | * Compare two extended attribute blocks for equality. | |
1423 | * | |
1424 | * Returns 0 if the blocks are equal, 1 if they differ, and | |
1425 | * a negative error number on errors. | |
1426 | */ | |
1427 | static int | |
617ba13b MC |
1428 | ext4_xattr_cmp(struct ext4_xattr_header *header1, |
1429 | struct ext4_xattr_header *header2) | |
ac27a0ec | 1430 | { |
617ba13b | 1431 | struct ext4_xattr_entry *entry1, *entry2; |
ac27a0ec DK |
1432 | |
1433 | entry1 = ENTRY(header1+1); | |
1434 | entry2 = ENTRY(header2+1); | |
1435 | while (!IS_LAST_ENTRY(entry1)) { | |
1436 | if (IS_LAST_ENTRY(entry2)) | |
1437 | return 1; | |
1438 | if (entry1->e_hash != entry2->e_hash || | |
1439 | entry1->e_name_index != entry2->e_name_index || | |
1440 | entry1->e_name_len != entry2->e_name_len || | |
1441 | entry1->e_value_size != entry2->e_value_size || | |
1442 | memcmp(entry1->e_name, entry2->e_name, entry1->e_name_len)) | |
1443 | return 1; | |
1444 | if (entry1->e_value_block != 0 || entry2->e_value_block != 0) | |
1445 | return -EIO; | |
1446 | if (memcmp((char *)header1 + le16_to_cpu(entry1->e_value_offs), | |
1447 | (char *)header2 + le16_to_cpu(entry2->e_value_offs), | |
1448 | le32_to_cpu(entry1->e_value_size))) | |
1449 | return 1; | |
1450 | ||
617ba13b MC |
1451 | entry1 = EXT4_XATTR_NEXT(entry1); |
1452 | entry2 = EXT4_XATTR_NEXT(entry2); | |
ac27a0ec DK |
1453 | } |
1454 | if (!IS_LAST_ENTRY(entry2)) | |
1455 | return 1; | |
1456 | return 0; | |
1457 | } | |
1458 | ||
1459 | /* | |
617ba13b | 1460 | * ext4_xattr_cache_find() |
ac27a0ec DK |
1461 | * |
1462 | * Find an identical extended attribute block. | |
1463 | * | |
1464 | * Returns a pointer to the block found, or NULL if such a block was | |
1465 | * not found or an error occurred. | |
1466 | */ | |
1467 | static struct buffer_head * | |
617ba13b | 1468 | ext4_xattr_cache_find(struct inode *inode, struct ext4_xattr_header *header, |
ac27a0ec DK |
1469 | struct mb_cache_entry **pce) |
1470 | { | |
1471 | __u32 hash = le32_to_cpu(header->h_hash); | |
1472 | struct mb_cache_entry *ce; | |
1473 | ||
1474 | if (!header->h_hash) | |
1475 | return NULL; /* never share */ | |
1476 | ea_idebug(inode, "looking for cached blocks [%x]", (int)hash); | |
1477 | again: | |
617ba13b | 1478 | ce = mb_cache_entry_find_first(ext4_xattr_cache, 0, |
ac27a0ec DK |
1479 | inode->i_sb->s_bdev, hash); |
1480 | while (ce) { | |
1481 | struct buffer_head *bh; | |
1482 | ||
1483 | if (IS_ERR(ce)) { | |
1484 | if (PTR_ERR(ce) == -EAGAIN) | |
1485 | goto again; | |
1486 | break; | |
1487 | } | |
1488 | bh = sb_bread(inode->i_sb, ce->e_block); | |
1489 | if (!bh) { | |
46e665e9 | 1490 | ext4_error(inode->i_sb, __func__, |
ac27a0ec DK |
1491 | "inode %lu: block %lu read error", |
1492 | inode->i_ino, (unsigned long) ce->e_block); | |
1493 | } else if (le32_to_cpu(BHDR(bh)->h_refcount) >= | |
617ba13b | 1494 | EXT4_XATTR_REFCOUNT_MAX) { |
ac27a0ec DK |
1495 | ea_idebug(inode, "block %lu refcount %d>=%d", |
1496 | (unsigned long) ce->e_block, | |
1497 | le32_to_cpu(BHDR(bh)->h_refcount), | |
617ba13b MC |
1498 | EXT4_XATTR_REFCOUNT_MAX); |
1499 | } else if (ext4_xattr_cmp(header, BHDR(bh)) == 0) { | |
ac27a0ec DK |
1500 | *pce = ce; |
1501 | return bh; | |
1502 | } | |
1503 | brelse(bh); | |
1504 | ce = mb_cache_entry_find_next(ce, 0, inode->i_sb->s_bdev, hash); | |
1505 | } | |
1506 | return NULL; | |
1507 | } | |
1508 | ||
1509 | #define NAME_HASH_SHIFT 5 | |
1510 | #define VALUE_HASH_SHIFT 16 | |
1511 | ||
1512 | /* | |
617ba13b | 1513 | * ext4_xattr_hash_entry() |
ac27a0ec DK |
1514 | * |
1515 | * Compute the hash of an extended attribute. | |
1516 | */ | |
617ba13b MC |
1517 | static inline void ext4_xattr_hash_entry(struct ext4_xattr_header *header, |
1518 | struct ext4_xattr_entry *entry) | |
ac27a0ec DK |
1519 | { |
1520 | __u32 hash = 0; | |
1521 | char *name = entry->e_name; | |
1522 | int n; | |
1523 | ||
2b2d6d01 | 1524 | for (n = 0; n < entry->e_name_len; n++) { |
ac27a0ec DK |
1525 | hash = (hash << NAME_HASH_SHIFT) ^ |
1526 | (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^ | |
1527 | *name++; | |
1528 | } | |
1529 | ||
1530 | if (entry->e_value_block == 0 && entry->e_value_size != 0) { | |
1531 | __le32 *value = (__le32 *)((char *)header + | |
1532 | le16_to_cpu(entry->e_value_offs)); | |
1533 | for (n = (le32_to_cpu(entry->e_value_size) + | |
617ba13b | 1534 | EXT4_XATTR_ROUND) >> EXT4_XATTR_PAD_BITS; n; n--) { |
ac27a0ec DK |
1535 | hash = (hash << VALUE_HASH_SHIFT) ^ |
1536 | (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^ | |
1537 | le32_to_cpu(*value++); | |
1538 | } | |
1539 | } | |
1540 | entry->e_hash = cpu_to_le32(hash); | |
1541 | } | |
1542 | ||
1543 | #undef NAME_HASH_SHIFT | |
1544 | #undef VALUE_HASH_SHIFT | |
1545 | ||
1546 | #define BLOCK_HASH_SHIFT 16 | |
1547 | ||
1548 | /* | |
617ba13b | 1549 | * ext4_xattr_rehash() |
ac27a0ec DK |
1550 | * |
1551 | * Re-compute the extended attribute hash value after an entry has changed. | |
1552 | */ | |
617ba13b MC |
1553 | static void ext4_xattr_rehash(struct ext4_xattr_header *header, |
1554 | struct ext4_xattr_entry *entry) | |
ac27a0ec | 1555 | { |
617ba13b | 1556 | struct ext4_xattr_entry *here; |
ac27a0ec DK |
1557 | __u32 hash = 0; |
1558 | ||
617ba13b | 1559 | ext4_xattr_hash_entry(header, entry); |
ac27a0ec DK |
1560 | here = ENTRY(header+1); |
1561 | while (!IS_LAST_ENTRY(here)) { | |
1562 | if (!here->e_hash) { | |
1563 | /* Block is not shared if an entry's hash value == 0 */ | |
1564 | hash = 0; | |
1565 | break; | |
1566 | } | |
1567 | hash = (hash << BLOCK_HASH_SHIFT) ^ | |
1568 | (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^ | |
1569 | le32_to_cpu(here->e_hash); | |
617ba13b | 1570 | here = EXT4_XATTR_NEXT(here); |
ac27a0ec DK |
1571 | } |
1572 | header->h_hash = cpu_to_le32(hash); | |
1573 | } | |
1574 | ||
1575 | #undef BLOCK_HASH_SHIFT | |
1576 | ||
1577 | int __init | |
617ba13b | 1578 | init_ext4_xattr(void) |
ac27a0ec | 1579 | { |
617ba13b | 1580 | ext4_xattr_cache = mb_cache_create("ext4_xattr", NULL, |
ac27a0ec DK |
1581 | sizeof(struct mb_cache_entry) + |
1582 | sizeof(((struct mb_cache_entry *) 0)->e_indexes[0]), 1, 6); | |
617ba13b | 1583 | if (!ext4_xattr_cache) |
ac27a0ec DK |
1584 | return -ENOMEM; |
1585 | return 0; | |
1586 | } | |
1587 | ||
1588 | void | |
617ba13b | 1589 | exit_ext4_xattr(void) |
ac27a0ec | 1590 | { |
617ba13b MC |
1591 | if (ext4_xattr_cache) |
1592 | mb_cache_destroy(ext4_xattr_cache); | |
1593 | ext4_xattr_cache = NULL; | |
ac27a0ec | 1594 | } |