?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
tools uapi asm: Update asm-generic/unistd.h copy
[linux/fpc-iii.git] / fs / ext4 / xattr.c
blob7643d52c776c61188ca6ac4a7ddd18d303c96e47
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * linux/fs/ext4/xattr.c
4 *
5 * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
6 *
7 * Fix by Harrison Xing <harrison@mountainviewdata.com>.
8 * Ext4 code with a lot of help from Eric Jarman <ejarman@acm.org>.
9 * Extended attributes for symlinks and special files added per
10 * suggestion of Luka Renko <luka.renko@hermes.si>.
11 * xattr consolidation Copyright (c) 2004 James Morris <jmorris@redhat.com>,
12 * Red Hat Inc.
13 * ea-in-inode support by Alex Tomas <alex@clusterfs.com> aka bzzz
14 * and Andreas Gruenbacher <agruen@suse.de>.
15 */
16
17 /*
18 * Extended attributes are stored directly in inodes (on file systems with
19 * inodes bigger than 128 bytes) and on additional disk blocks. The i_file_acl
20 * field contains the block number if an inode uses an additional block. All
21 * attributes must fit in the inode and one additional block. Blocks that
22 * contain the identical set of attributes may be shared among several inodes.
23 * Identical blocks are detected by keeping a cache of blocks that have
24 * recently been accessed.
25 *
26 * The attributes in inodes and on blocks have a different header; the entries
27 * are stored in the same format:
28 *
29 * +------------------+
30 * | header |
31 * | entry 1 | |
32 * | entry 2 | | growing downwards
33 * | entry 3 | v
34 * | four null bytes |
35 * | . . . |
36 * | value 1 | ^
37 * | value 3 | | growing upwards
38 * | value 2 | |
39 * +------------------+
40 *
41 * The header is followed by multiple entry descriptors. In disk blocks, the
42 * entry descriptors are kept sorted. In inodes, they are unsorted. The
43 * attribute values are aligned to the end of the block in no specific order.
44 *
45 * Locking strategy
46 * ----------------
47 * EXT4_I(inode)->i_file_acl is protected by EXT4_I(inode)->xattr_sem.
48 * EA blocks are only changed if they are exclusive to an inode, so
49 * holding xattr_sem also means that nothing but the EA block's reference
50 * count can change. Multiple writers to the same block are synchronized
51 * by the buffer lock.
52 */
53
54 #include <linux/init.h>
55 #include <linux/fs.h>
56 #include <linux/slab.h>
57 #include <linux/mbcache.h>
58 #include <linux/quotaops.h>
59 #include <linux/iversion.h>
60 #include "ext4_jbd2.h"
61 #include "ext4.h"
62 #include "xattr.h"
63 #include "acl.h"
64
65 #ifdef EXT4_XATTR_DEBUG
66 # define ea_idebug(inode, fmt, ...) \
67 printk(KERN_DEBUG "inode %s:%lu: " fmt "\n", \
68 inode->i_sb->s_id, inode->i_ino, ##__VA_ARGS__)
69 # define ea_bdebug(bh, fmt, ...) \
70 printk(KERN_DEBUG "block %pg:%lu: " fmt "\n", \
71 bh->b_bdev, (unsigned long)bh->b_blocknr, ##__VA_ARGS__)
72 #else
73 # define ea_idebug(inode, fmt, ...) no_printk(fmt, ##__VA_ARGS__)
74 # define ea_bdebug(bh, fmt, ...) no_printk(fmt, ##__VA_ARGS__)
75 #endif
76
77 static void ext4_xattr_block_cache_insert(struct mb_cache *,
78 struct buffer_head *);
79 static struct buffer_head *
80 ext4_xattr_block_cache_find(struct inode *, struct ext4_xattr_header *,
81 struct mb_cache_entry **);
82 static __le32 ext4_xattr_hash_entry(char *name, size_t name_len, __le32 *value,
83 size_t value_count);
84 static void ext4_xattr_rehash(struct ext4_xattr_header *);
85
86 static const struct xattr_handler * const ext4_xattr_handler_map[] = {
87 [EXT4_XATTR_INDEX_USER] = &ext4_xattr_user_handler,
88 #ifdef CONFIG_EXT4_FS_POSIX_ACL
89 [EXT4_XATTR_INDEX_POSIX_ACL_ACCESS] = &posix_acl_access_xattr_handler,
90 [EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT] = &posix_acl_default_xattr_handler,
91 #endif
92 [EXT4_XATTR_INDEX_TRUSTED] = &ext4_xattr_trusted_handler,
93 #ifdef CONFIG_EXT4_FS_SECURITY
94 [EXT4_XATTR_INDEX_SECURITY] = &ext4_xattr_security_handler,
95 #endif
96 };
97
98 const struct xattr_handler *ext4_xattr_handlers[] = {
99 &ext4_xattr_user_handler,
100 &ext4_xattr_trusted_handler,
101 #ifdef CONFIG_EXT4_FS_POSIX_ACL
102 &posix_acl_access_xattr_handler,
103 &posix_acl_default_xattr_handler,
104 #endif
105 #ifdef CONFIG_EXT4_FS_SECURITY
106 &ext4_xattr_security_handler,
107 #endif
108 NULL
109 };
110
111 #define EA_BLOCK_CACHE(inode) (((struct ext4_sb_info *) \
112 inode->i_sb->s_fs_info)->s_ea_block_cache)
113
114 #define EA_INODE_CACHE(inode) (((struct ext4_sb_info *) \
115 inode->i_sb->s_fs_info)->s_ea_inode_cache)
116
117 static int
118 ext4_expand_inode_array(struct ext4_xattr_inode_array **ea_inode_array,
119 struct inode *inode);
120
121 #ifdef CONFIG_LOCKDEP
122 void ext4_xattr_inode_set_class(struct inode *ea_inode)
123 {
124 lockdep_set_subclass(&ea_inode->i_rwsem, 1);
125 }
126 #endif
127
128 static __le32 ext4_xattr_block_csum(struct inode *inode,
129 sector_t block_nr,
130 struct ext4_xattr_header *hdr)
131 {
132 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
133 __u32 csum;
134 __le64 dsk_block_nr = cpu_to_le64(block_nr);
135 __u32 dummy_csum = 0;
136 int offset = offsetof(struct ext4_xattr_header, h_checksum);
137
138 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&dsk_block_nr,
139 sizeof(dsk_block_nr));
140 csum = ext4_chksum(sbi, csum, (__u8 *)hdr, offset);
141 csum = ext4_chksum(sbi, csum, (__u8 *)&dummy_csum, sizeof(dummy_csum));
142 offset += sizeof(dummy_csum);
143 csum = ext4_chksum(sbi, csum, (__u8 *)hdr + offset,
144 EXT4_BLOCK_SIZE(inode->i_sb) - offset);
145
146 return cpu_to_le32(csum);
147 }
148
149 static int ext4_xattr_block_csum_verify(struct inode *inode,
150 struct buffer_head *bh)
151 {
152 struct ext4_xattr_header *hdr = BHDR(bh);
153 int ret = 1;
154
155 if (ext4_has_metadata_csum(inode->i_sb)) {
156 lock_buffer(bh);
157 ret = (hdr->h_checksum == ext4_xattr_block_csum(inode,
158 bh->b_blocknr, hdr));
159 unlock_buffer(bh);
160 }
161 return ret;
162 }
163
164 static void ext4_xattr_block_csum_set(struct inode *inode,
165 struct buffer_head *bh)
166 {
167 if (ext4_has_metadata_csum(inode->i_sb))
168 BHDR(bh)->h_checksum = ext4_xattr_block_csum(inode,
169 bh->b_blocknr, BHDR(bh));
170 }
171
172 static inline const struct xattr_handler *
173 ext4_xattr_handler(int name_index)
174 {
175 const struct xattr_handler *handler = NULL;
176
177 if (name_index > 0 && name_index < ARRAY_SIZE(ext4_xattr_handler_map))
178 handler = ext4_xattr_handler_map[name_index];
179 return handler;
180 }
181
182 static int
183 ext4_xattr_check_entries(struct ext4_xattr_entry *entry, void *end,
184 void *value_start)
185 {
186 struct ext4_xattr_entry *e = entry;
187
188 /* Find the end of the names list */
189 while (!IS_LAST_ENTRY(e)) {
190 struct ext4_xattr_entry *next = EXT4_XATTR_NEXT(e);
191 if ((void *)next >= end)
192 return -EFSCORRUPTED;
193 if (strnlen(e->e_name, e->e_name_len) != e->e_name_len)
194 return -EFSCORRUPTED;
195 e = next;
196 }
197
198 /* Check the values */
199 while (!IS_LAST_ENTRY(entry)) {
200 u32 size = le32_to_cpu(entry->e_value_size);
201
202 if (size > EXT4_XATTR_SIZE_MAX)
203 return -EFSCORRUPTED;
204
205 if (size != 0 && entry->e_value_inum == 0) {
206 u16 offs = le16_to_cpu(entry->e_value_offs);
207 void *value;
208
209 /*
210 * The value cannot overlap the names, and the value
211 * with padding cannot extend beyond 'end'. Check both
212 * the padded and unpadded sizes, since the size may
213 * overflow to 0 when adding padding.
214 */
215 if (offs > end - value_start)
216 return -EFSCORRUPTED;
217 value = value_start + offs;
218 if (value < (void *)e + sizeof(u32) ||
219 size > end - value ||
220 EXT4_XATTR_SIZE(size) > end - value)
221 return -EFSCORRUPTED;
222 }
223 entry = EXT4_XATTR_NEXT(entry);
224 }
225
226 return 0;
227 }
228
229 static inline int
230 __ext4_xattr_check_block(struct inode *inode, struct buffer_head *bh,
231 const char *function, unsigned int line)
232 {
233 int error = -EFSCORRUPTED;
234
235 if (BHDR(bh)->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC) ||
236 BHDR(bh)->h_blocks != cpu_to_le32(1))
237 goto errout;
238 if (buffer_verified(bh))
239 return 0;
240
241 error = -EFSBADCRC;
242 if (!ext4_xattr_block_csum_verify(inode, bh))
243 goto errout;
244 error = ext4_xattr_check_entries(BFIRST(bh), bh->b_data + bh->b_size,
245 bh->b_data);
246 errout:
247 if (error)
248 __ext4_error_inode(inode, function, line, 0,
249 "corrupted xattr block %llu",
250 (unsigned long long) bh->b_blocknr);
251 else
252 set_buffer_verified(bh);
253 return error;
254 }
255
256 #define ext4_xattr_check_block(inode, bh) \
257 __ext4_xattr_check_block((inode), (bh), __func__, __LINE__)
258
259
260 static int
261 __xattr_check_inode(struct inode *inode, struct ext4_xattr_ibody_header *header,
262 void *end, const char *function, unsigned int line)
263 {
264 int error = -EFSCORRUPTED;
265
266 if (end - (void *)header < sizeof(*header) + sizeof(u32) ||
267 (header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC)))
268 goto errout;
269 error = ext4_xattr_check_entries(IFIRST(header), end, IFIRST(header));
270 errout:
271 if (error)
272 __ext4_error_inode(inode, function, line, 0,
273 "corrupted in-inode xattr");
274 return error;
275 }
276
277 #define xattr_check_inode(inode, header, end) \
278 __xattr_check_inode((inode), (header), (end), __func__, __LINE__)
279
280 static int
281 xattr_find_entry(struct inode *inode, struct ext4_xattr_entry **pentry,
282 void *end, int name_index, const char *name, int sorted)
283 {
284 struct ext4_xattr_entry *entry, *next;
285 size_t name_len;
286 int cmp = 1;
287
288 if (name == NULL)
289 return -EINVAL;
290 name_len = strlen(name);
291 for (entry = *pentry; !IS_LAST_ENTRY(entry); entry = next) {
292 next = EXT4_XATTR_NEXT(entry);
293 if ((void *) next >= end) {
294 EXT4_ERROR_INODE(inode, "corrupted xattr entries");
295 return -EFSCORRUPTED;
296 }
297 cmp = name_index - entry->e_name_index;
298 if (!cmp)
299 cmp = name_len - entry->e_name_len;
300 if (!cmp)
301 cmp = memcmp(name, entry->e_name, name_len);
302 if (cmp <= 0 && (sorted || cmp == 0))
303 break;
304 }
305 *pentry = entry;
306 return cmp ? -ENODATA : 0;
307 }
308
309 static u32
310 ext4_xattr_inode_hash(struct ext4_sb_info *sbi, const void *buffer, size_t size)
311 {
312 return ext4_chksum(sbi, sbi->s_csum_seed, buffer, size);
313 }
314
315 static u64 ext4_xattr_inode_get_ref(struct inode *ea_inode)
316 {
317 return ((u64)ea_inode->i_ctime.tv_sec << 32) |
318 (u32) inode_peek_iversion_raw(ea_inode);
319 }
320
321 static void ext4_xattr_inode_set_ref(struct inode *ea_inode, u64 ref_count)
322 {
323 ea_inode->i_ctime.tv_sec = (u32)(ref_count >> 32);
324 inode_set_iversion_raw(ea_inode, ref_count & 0xffffffff);
325 }
326
327 static u32 ext4_xattr_inode_get_hash(struct inode *ea_inode)
328 {
329 return (u32)ea_inode->i_atime.tv_sec;
330 }
331
332 static void ext4_xattr_inode_set_hash(struct inode *ea_inode, u32 hash)
333 {
334 ea_inode->i_atime.tv_sec = hash;
335 }
336
337 /*
338 * Read the EA value from an inode.
339 */
340 static int ext4_xattr_inode_read(struct inode *ea_inode, void *buf, size_t size)
341 {
342 int blocksize = 1 << ea_inode->i_blkbits;
343 int bh_count = (size + blocksize - 1) >> ea_inode->i_blkbits;
344 int tail_size = (size % blocksize) ?: blocksize;
345 struct buffer_head *bhs_inline[8];
346 struct buffer_head **bhs = bhs_inline;
347 int i, ret;
348
349 if (bh_count > ARRAY_SIZE(bhs_inline)) {
350 bhs = kmalloc_array(bh_count, sizeof(*bhs), GFP_NOFS);
351 if (!bhs)
352 return -ENOMEM;
353 }
354
355 ret = ext4_bread_batch(ea_inode, 0 /* block */, bh_count,
356 true /* wait */, bhs);
357 if (ret)
358 goto free_bhs;
359
360 for (i = 0; i < bh_count; i++) {
361 /* There shouldn't be any holes in ea_inode. */
362 if (!bhs[i]) {
363 ret = -EFSCORRUPTED;
364 goto put_bhs;
365 }
366 memcpy((char *)buf + blocksize * i, bhs[i]->b_data,
367 i < bh_count - 1 ? blocksize : tail_size);
368 }
369 ret = 0;
370 put_bhs:
371 for (i = 0; i < bh_count; i++)
372 brelse(bhs[i]);
373 free_bhs:
374 if (bhs != bhs_inline)
375 kfree(bhs);
376 return ret;
377 }
378
379 #define EXT4_XATTR_INODE_GET_PARENT(inode) ((__u32)(inode)->i_mtime.tv_sec)
380
381 static int ext4_xattr_inode_iget(struct inode *parent, unsigned long ea_ino,
382 u32 ea_inode_hash, struct inode **ea_inode)
383 {
384 struct inode *inode;
385 int err;
386
387 inode = ext4_iget(parent->i_sb, ea_ino);
388 if (IS_ERR(inode)) {
389 err = PTR_ERR(inode);
390 ext4_error(parent->i_sb,
391 "error while reading EA inode %lu err=%d", ea_ino,
392 err);
393 return err;
394 }
395
396 if (is_bad_inode(inode)) {
397 ext4_error(parent->i_sb,
398 "error while reading EA inode %lu is_bad_inode",
399 ea_ino);
400 err = -EIO;
401 goto error;
402 }
403
404 if (!(EXT4_I(inode)->i_flags & EXT4_EA_INODE_FL)) {
405 ext4_error(parent->i_sb,
406 "EA inode %lu does not have EXT4_EA_INODE_FL flag",
407 ea_ino);
408 err = -EINVAL;
409 goto error;
410 }
411
412 ext4_xattr_inode_set_class(inode);
413
414 /*
415 * Check whether this is an old Lustre-style xattr inode. Lustre
416 * implementation does not have hash validation, rather it has a
417 * backpointer from ea_inode to the parent inode.
418 */
419 if (ea_inode_hash != ext4_xattr_inode_get_hash(inode) &&
420 EXT4_XATTR_INODE_GET_PARENT(inode) == parent->i_ino &&
421 inode->i_generation == parent->i_generation) {
422 ext4_set_inode_state(inode, EXT4_STATE_LUSTRE_EA_INODE);
423 ext4_xattr_inode_set_ref(inode, 1);
424 } else {
425 inode_lock(inode);
426 inode->i_flags |= S_NOQUOTA;
427 inode_unlock(inode);
428 }
429
430 *ea_inode = inode;
431 return 0;
432 error:
433 iput(inode);
434 return err;
435 }
436
437 static int
438 ext4_xattr_inode_verify_hashes(struct inode *ea_inode,
439 struct ext4_xattr_entry *entry, void *buffer,
440 size_t size)
441 {
442 u32 hash;
443
444 /* Verify stored hash matches calculated hash. */
445 hash = ext4_xattr_inode_hash(EXT4_SB(ea_inode->i_sb), buffer, size);
446 if (hash != ext4_xattr_inode_get_hash(ea_inode))
447 return -EFSCORRUPTED;
448
449 if (entry) {
450 __le32 e_hash, tmp_data;
451
452 /* Verify entry hash. */
453 tmp_data = cpu_to_le32(hash);
454 e_hash = ext4_xattr_hash_entry(entry->e_name, entry->e_name_len,
455 &tmp_data, 1);
456 if (e_hash != entry->e_hash)
457 return -EFSCORRUPTED;
458 }
459 return 0;
460 }
461
462 /*
463 * Read xattr value from the EA inode.
464 */
465 static int
466 ext4_xattr_inode_get(struct inode *inode, struct ext4_xattr_entry *entry,
467 void *buffer, size_t size)
468 {
469 struct mb_cache *ea_inode_cache = EA_INODE_CACHE(inode);
470 struct inode *ea_inode;
471 int err;
472
473 err = ext4_xattr_inode_iget(inode, le32_to_cpu(entry->e_value_inum),
474 le32_to_cpu(entry->e_hash), &ea_inode);
475 if (err) {
476 ea_inode = NULL;
477 goto out;
478 }
479
480 if (i_size_read(ea_inode) != size) {
481 ext4_warning_inode(ea_inode,
482 "ea_inode file size=%llu entry size=%zu",
483 i_size_read(ea_inode), size);
484 err = -EFSCORRUPTED;
485 goto out;
486 }
487
488 err = ext4_xattr_inode_read(ea_inode, buffer, size);
489 if (err)
490 goto out;
491
492 if (!ext4_test_inode_state(ea_inode, EXT4_STATE_LUSTRE_EA_INODE)) {
493 err = ext4_xattr_inode_verify_hashes(ea_inode, entry, buffer,
494 size);
495 if (err) {
496 ext4_warning_inode(ea_inode,
497 "EA inode hash validation failed");
498 goto out;
499 }
500
501 if (ea_inode_cache)
502 mb_cache_entry_create(ea_inode_cache, GFP_NOFS,
503 ext4_xattr_inode_get_hash(ea_inode),
504 ea_inode->i_ino, true /* reusable */);
505 }
506 out:
507 iput(ea_inode);
508 return err;
509 }
510
511 static int
512 ext4_xattr_block_get(struct inode *inode, int name_index, const char *name,
513 void *buffer, size_t buffer_size)
514 {
515 struct buffer_head *bh = NULL;
516 struct ext4_xattr_entry *entry;
517 size_t size;
518 void *end;
519 int error;
520 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
521
522 ea_idebug(inode, "name=%d.%s, buffer=%p, buffer_size=%ld",
523 name_index, name, buffer, (long)buffer_size);
524
525 error = -ENODATA;
526 if (!EXT4_I(inode)->i_file_acl)
527 goto cleanup;
528 ea_idebug(inode, "reading block %llu",
529 (unsigned long long)EXT4_I(inode)->i_file_acl);
530 bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl);
531 if (!bh)
532 goto cleanup;
533 ea_bdebug(bh, "b_count=%d, refcount=%d",
534 atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount));
535 error = ext4_xattr_check_block(inode, bh);
536 if (error)
537 goto cleanup;
538 ext4_xattr_block_cache_insert(ea_block_cache, bh);
539 entry = BFIRST(bh);
540 end = bh->b_data + bh->b_size;
541 error = xattr_find_entry(inode, &entry, end, name_index, name, 1);
542 if (error)
543 goto cleanup;
544 size = le32_to_cpu(entry->e_value_size);
545 error = -ERANGE;
546 if (unlikely(size > EXT4_XATTR_SIZE_MAX))
547 goto cleanup;
548 if (buffer) {
549 if (size > buffer_size)
550 goto cleanup;
551 if (entry->e_value_inum) {
552 error = ext4_xattr_inode_get(inode, entry, buffer,
553 size);
554 if (error)
555 goto cleanup;
556 } else {
557 u16 offset = le16_to_cpu(entry->e_value_offs);
558 void *p = bh->b_data + offset;
559
560 if (unlikely(p + size > end))
561 goto cleanup;
562 memcpy(buffer, p, size);
563 }
564 }
565 error = size;
566
567 cleanup:
568 brelse(bh);
569 return error;
570 }
571
572 int
573 ext4_xattr_ibody_get(struct inode *inode, int name_index, const char *name,
574 void *buffer, size_t buffer_size)
575 {
576 struct ext4_xattr_ibody_header *header;
577 struct ext4_xattr_entry *entry;
578 struct ext4_inode *raw_inode;
579 struct ext4_iloc iloc;
580 size_t size;
581 void *end;
582 int error;
583
584 if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR))
585 return -ENODATA;
586 error = ext4_get_inode_loc(inode, &iloc);
587 if (error)
588 return error;
589 raw_inode = ext4_raw_inode(&iloc);
590 header = IHDR(inode, raw_inode);
591 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
592 error = xattr_check_inode(inode, header, end);
593 if (error)
594 goto cleanup;
595 entry = IFIRST(header);
596 error = xattr_find_entry(inode, &entry, end, name_index, name, 0);
597 if (error)
598 goto cleanup;
599 size = le32_to_cpu(entry->e_value_size);
600 error = -ERANGE;
601 if (unlikely(size > EXT4_XATTR_SIZE_MAX))
602 goto cleanup;
603 if (buffer) {
604 if (size > buffer_size)
605 goto cleanup;
606 if (entry->e_value_inum) {
607 error = ext4_xattr_inode_get(inode, entry, buffer,
608 size);
609 if (error)
610 goto cleanup;
611 } else {
612 u16 offset = le16_to_cpu(entry->e_value_offs);
613 void *p = (void *)IFIRST(header) + offset;
614
615 if (unlikely(p + size > end))
616 goto cleanup;
617 memcpy(buffer, p, size);
618 }
619 }
620 error = size;
621
622 cleanup:
623 brelse(iloc.bh);
624 return error;
625 }
626
627 /*
628 * ext4_xattr_get()
629 *
630 * Copy an extended attribute into the buffer
631 * provided, or compute the buffer size required.
632 * Buffer is NULL to compute the size of the buffer required.
633 *
634 * Returns a negative error number on failure, or the number of bytes
635 * used / required on success.
636 */
637 int
638 ext4_xattr_get(struct inode *inode, int name_index, const char *name,
639 void *buffer, size_t buffer_size)
640 {
641 int error;
642
643 if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
644 return -EIO;
645
646 if (strlen(name) > 255)
647 return -ERANGE;
648
649 down_read(&EXT4_I(inode)->xattr_sem);
650 error = ext4_xattr_ibody_get(inode, name_index, name, buffer,
651 buffer_size);
652 if (error == -ENODATA)
653 error = ext4_xattr_block_get(inode, name_index, name, buffer,
654 buffer_size);
655 up_read(&EXT4_I(inode)->xattr_sem);
656 return error;
657 }
658
659 static int
660 ext4_xattr_list_entries(struct dentry *dentry, struct ext4_xattr_entry *entry,
661 char *buffer, size_t buffer_size)
662 {
663 size_t rest = buffer_size;
664
665 for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) {
666 const struct xattr_handler *handler =
667 ext4_xattr_handler(entry->e_name_index);
668
669 if (handler && (!handler->list || handler->list(dentry))) {
670 const char *prefix = handler->prefix ?: handler->name;
671 size_t prefix_len = strlen(prefix);
672 size_t size = prefix_len + entry->e_name_len + 1;
673
674 if (buffer) {
675 if (size > rest)
676 return -ERANGE;
677 memcpy(buffer, prefix, prefix_len);
678 buffer += prefix_len;
679 memcpy(buffer, entry->e_name, entry->e_name_len);
680 buffer += entry->e_name_len;
681 *buffer++ = 0;
682 }
683 rest -= size;
684 }
685 }
686 return buffer_size - rest; /* total size */
687 }
688
689 static int
690 ext4_xattr_block_list(struct dentry *dentry, char *buffer, size_t buffer_size)
691 {
692 struct inode *inode = d_inode(dentry);
693 struct buffer_head *bh = NULL;
694 int error;
695
696 ea_idebug(inode, "buffer=%p, buffer_size=%ld",
697 buffer, (long)buffer_size);
698
699 error = 0;
700 if (!EXT4_I(inode)->i_file_acl)
701 goto cleanup;
702 ea_idebug(inode, "reading block %llu",
703 (unsigned long long)EXT4_I(inode)->i_file_acl);
704 bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl);
705 error = -EIO;
706 if (!bh)
707 goto cleanup;
708 ea_bdebug(bh, "b_count=%d, refcount=%d",
709 atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount));
710 error = ext4_xattr_check_block(inode, bh);
711 if (error)
712 goto cleanup;
713 ext4_xattr_block_cache_insert(EA_BLOCK_CACHE(inode), bh);
714 error = ext4_xattr_list_entries(dentry, BFIRST(bh), buffer, buffer_size);
715
716 cleanup:
717 brelse(bh);
718
719 return error;
720 }
721
722 static int
723 ext4_xattr_ibody_list(struct dentry *dentry, char *buffer, size_t buffer_size)
724 {
725 struct inode *inode = d_inode(dentry);
726 struct ext4_xattr_ibody_header *header;
727 struct ext4_inode *raw_inode;
728 struct ext4_iloc iloc;
729 void *end;
730 int error;
731
732 if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR))
733 return 0;
734 error = ext4_get_inode_loc(inode, &iloc);
735 if (error)
736 return error;
737 raw_inode = ext4_raw_inode(&iloc);
738 header = IHDR(inode, raw_inode);
739 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
740 error = xattr_check_inode(inode, header, end);
741 if (error)
742 goto cleanup;
743 error = ext4_xattr_list_entries(dentry, IFIRST(header),
744 buffer, buffer_size);
745
746 cleanup:
747 brelse(iloc.bh);
748 return error;
749 }
750
751 /*
752 * Inode operation listxattr()
753 *
754 * d_inode(dentry)->i_rwsem: don't care
755 *
756 * Copy a list of attribute names into the buffer
757 * provided, or compute the buffer size required.
758 * Buffer is NULL to compute the size of the buffer required.
759 *
760 * Returns a negative error number on failure, or the number of bytes
761 * used / required on success.
762 */
763 ssize_t
764 ext4_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
765 {
766 int ret, ret2;
767
768 down_read(&EXT4_I(d_inode(dentry))->xattr_sem);
769 ret = ret2 = ext4_xattr_ibody_list(dentry, buffer, buffer_size);
770 if (ret < 0)
771 goto errout;
772 if (buffer) {
773 buffer += ret;
774 buffer_size -= ret;
775 }
776 ret = ext4_xattr_block_list(dentry, buffer, buffer_size);
777 if (ret < 0)
778 goto errout;
779 ret += ret2;
780 errout:
781 up_read(&EXT4_I(d_inode(dentry))->xattr_sem);
782 return ret;
783 }
784
785 /*
786 * If the EXT4_FEATURE_COMPAT_EXT_ATTR feature of this file system is
787 * not set, set it.
788 */
789 static void ext4_xattr_update_super_block(handle_t *handle,
790 struct super_block *sb)
791 {
792 if (ext4_has_feature_xattr(sb))
793 return;
794
795 BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access");
796 if (ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh) == 0) {
797 ext4_set_feature_xattr(sb);
798 ext4_handle_dirty_super(handle, sb);
799 }
800 }
801
802 int ext4_get_inode_usage(struct inode *inode, qsize_t *usage)
803 {
804 struct ext4_iloc iloc = { .bh = NULL };
805 struct buffer_head *bh = NULL;
806 struct ext4_inode *raw_inode;
807 struct ext4_xattr_ibody_header *header;
808 struct ext4_xattr_entry *entry;
809 qsize_t ea_inode_refs = 0;
810 void *end;
811 int ret;
812
813 lockdep_assert_held_read(&EXT4_I(inode)->xattr_sem);
814
815 if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
816 ret = ext4_get_inode_loc(inode, &iloc);
817 if (ret)
818 goto out;
819 raw_inode = ext4_raw_inode(&iloc);
820 header = IHDR(inode, raw_inode);
821 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
822 ret = xattr_check_inode(inode, header, end);
823 if (ret)
824 goto out;
825
826 for (entry = IFIRST(header); !IS_LAST_ENTRY(entry);
827 entry = EXT4_XATTR_NEXT(entry))
828 if (entry->e_value_inum)
829 ea_inode_refs++;
830 }
831
832 if (EXT4_I(inode)->i_file_acl) {
833 bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl);
834 if (!bh) {
835 ret = -EIO;
836 goto out;
837 }
838
839 ret = ext4_xattr_check_block(inode, bh);
840 if (ret)
841 goto out;
842
843 for (entry = BFIRST(bh); !IS_LAST_ENTRY(entry);
844 entry = EXT4_XATTR_NEXT(entry))
845 if (entry->e_value_inum)
846 ea_inode_refs++;
847 }
848 *usage = ea_inode_refs + 1;
849 ret = 0;
850 out:
851 brelse(iloc.bh);
852 brelse(bh);
853 return ret;
854 }
855
856 static inline size_t round_up_cluster(struct inode *inode, size_t length)
857 {
858 struct super_block *sb = inode->i_sb;
859 size_t cluster_size = 1 << (EXT4_SB(sb)->s_cluster_bits +
860 inode->i_blkbits);
861 size_t mask = ~(cluster_size - 1);
862
863 return (length + cluster_size - 1) & mask;
864 }
865
866 static int ext4_xattr_inode_alloc_quota(struct inode *inode, size_t len)
867 {
868 int err;
869
870 err = dquot_alloc_inode(inode);
871 if (err)
872 return err;
873 err = dquot_alloc_space_nodirty(inode, round_up_cluster(inode, len));
874 if (err)
875 dquot_free_inode(inode);
876 return err;
877 }
878
879 static void ext4_xattr_inode_free_quota(struct inode *parent,
880 struct inode *ea_inode,
881 size_t len)
882 {
883 if (ea_inode &&
884 ext4_test_inode_state(ea_inode, EXT4_STATE_LUSTRE_EA_INODE))
885 return;
886 dquot_free_space_nodirty(parent, round_up_cluster(parent, len));
887 dquot_free_inode(parent);
888 }
889
890 int __ext4_xattr_set_credits(struct super_block *sb, struct inode *inode,
891 struct buffer_head *block_bh, size_t value_len,
892 bool is_create)
893 {
894 int credits;
895 int blocks;
896
897 /*
898 * 1) Owner inode update
899 * 2) Ref count update on old xattr block
900 * 3) new xattr block
901 * 4) block bitmap update for new xattr block
902 * 5) group descriptor for new xattr block
903 * 6) block bitmap update for old xattr block
904 * 7) group descriptor for old block
905 *
906 * 6 & 7 can happen if we have two racing threads T_a and T_b
907 * which are each trying to set an xattr on inodes I_a and I_b
908 * which were both initially sharing an xattr block.
909 */
910 credits = 7;
911
912 /* Quota updates. */
913 credits += EXT4_MAXQUOTAS_TRANS_BLOCKS(sb);
914
915 /*
916 * In case of inline data, we may push out the data to a block,
917 * so we need to reserve credits for this eventuality
918 */
919 if (inode && ext4_has_inline_data(inode))
920 credits += ext4_writepage_trans_blocks(inode) + 1;
921
922 /* We are done if ea_inode feature is not enabled. */
923 if (!ext4_has_feature_ea_inode(sb))
924 return credits;
925
926 /* New ea_inode, inode map, block bitmap, group descriptor. */
927 credits += 4;
928
929 /* Data blocks. */
930 blocks = (value_len + sb->s_blocksize - 1) >> sb->s_blocksize_bits;
931
932 /* Indirection block or one level of extent tree. */
933 blocks += 1;
934
935 /* Block bitmap and group descriptor updates for each block. */
936 credits += blocks * 2;
937
938 /* Blocks themselves. */
939 credits += blocks;
940
941 if (!is_create) {
942 /* Dereference ea_inode holding old xattr value.
943 * Old ea_inode, inode map, block bitmap, group descriptor.
944 */
945 credits += 4;
946
947 /* Data blocks for old ea_inode. */
948 blocks = XATTR_SIZE_MAX >> sb->s_blocksize_bits;
949
950 /* Indirection block or one level of extent tree for old
951 * ea_inode.
952 */
953 blocks += 1;
954
955 /* Block bitmap and group descriptor updates for each block. */
956 credits += blocks * 2;
957 }
958
959 /* We may need to clone the existing xattr block in which case we need
960 * to increment ref counts for existing ea_inodes referenced by it.
961 */
962 if (block_bh) {
963 struct ext4_xattr_entry *entry = BFIRST(block_bh);
964
965 for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry))
966 if (entry->e_value_inum)
967 /* Ref count update on ea_inode. */
968 credits += 1;
969 }
970 return credits;
971 }
972
973 static int ext4_xattr_ensure_credits(handle_t *handle, struct inode *inode,
974 int credits, struct buffer_head *bh,
975 bool dirty, bool block_csum)
976 {
977 int error;
978
979 if (!ext4_handle_valid(handle))
980 return 0;
981
982 if (handle->h_buffer_credits >= credits)
983 return 0;
984
985 error = ext4_journal_extend(handle, credits - handle->h_buffer_credits);
986 if (!error)
987 return 0;
988 if (error < 0) {
989 ext4_warning(inode->i_sb, "Extend journal (error %d)", error);
990 return error;
991 }
992
993 if (bh && dirty) {
994 if (block_csum)
995 ext4_xattr_block_csum_set(inode, bh);
996 error = ext4_handle_dirty_metadata(handle, NULL, bh);
997 if (error) {
998 ext4_warning(inode->i_sb, "Handle metadata (error %d)",
999 error);
1000 return error;
1001 }
1002 }
1003
1004 error = ext4_journal_restart(handle, credits);
1005 if (error) {
1006 ext4_warning(inode->i_sb, "Restart journal (error %d)", error);
1007 return error;
1008 }
1009
1010 if (bh) {
1011 error = ext4_journal_get_write_access(handle, bh);
1012 if (error) {
1013 ext4_warning(inode->i_sb,
1014 "Get write access failed (error %d)",
1015 error);
1016 return error;
1017 }
1018 }
1019 return 0;
1020 }
1021
1022 static int ext4_xattr_inode_update_ref(handle_t *handle, struct inode *ea_inode,
1023 int ref_change)
1024 {
1025 struct mb_cache *ea_inode_cache = EA_INODE_CACHE(ea_inode);
1026 struct ext4_iloc iloc;
1027 s64 ref_count;
1028 u32 hash;
1029 int ret;
1030
1031 inode_lock(ea_inode);
1032
1033 ret = ext4_reserve_inode_write(handle, ea_inode, &iloc);
1034 if (ret)
1035 goto out;
1036
1037 ref_count = ext4_xattr_inode_get_ref(ea_inode);
1038 ref_count += ref_change;
1039 ext4_xattr_inode_set_ref(ea_inode, ref_count);
1040
1041 if (ref_change > 0) {
1042 WARN_ONCE(ref_count <= 0, "EA inode %lu ref_count=%lld",
1043 ea_inode->i_ino, ref_count);
1044
1045 if (ref_count == 1) {
1046 WARN_ONCE(ea_inode->i_nlink, "EA inode %lu i_nlink=%u",
1047 ea_inode->i_ino, ea_inode->i_nlink);
1048
1049 set_nlink(ea_inode, 1);
1050 ext4_orphan_del(handle, ea_inode);
1051
1052 if (ea_inode_cache) {
1053 hash = ext4_xattr_inode_get_hash(ea_inode);
1054 mb_cache_entry_create(ea_inode_cache,
1055 GFP_NOFS, hash,
1056 ea_inode->i_ino,
1057 true /* reusable */);
1058 }
1059 }
1060 } else {
1061 WARN_ONCE(ref_count < 0, "EA inode %lu ref_count=%lld",
1062 ea_inode->i_ino, ref_count);
1063
1064 if (ref_count == 0) {
1065 WARN_ONCE(ea_inode->i_nlink != 1,
1066 "EA inode %lu i_nlink=%u",
1067 ea_inode->i_ino, ea_inode->i_nlink);
1068
1069 clear_nlink(ea_inode);
1070 ext4_orphan_add(handle, ea_inode);
1071
1072 if (ea_inode_cache) {
1073 hash = ext4_xattr_inode_get_hash(ea_inode);
1074 mb_cache_entry_delete(ea_inode_cache, hash,
1075 ea_inode->i_ino);
1076 }
1077 }
1078 }
1079
1080 ret = ext4_mark_iloc_dirty(handle, ea_inode, &iloc);
1081 if (ret)
1082 ext4_warning_inode(ea_inode,
1083 "ext4_mark_iloc_dirty() failed ret=%d", ret);
1084 out:
1085 inode_unlock(ea_inode);
1086 return ret;
1087 }
1088
1089 static int ext4_xattr_inode_inc_ref(handle_t *handle, struct inode *ea_inode)
1090 {
1091 return ext4_xattr_inode_update_ref(handle, ea_inode, 1);
1092 }
1093
1094 static int ext4_xattr_inode_dec_ref(handle_t *handle, struct inode *ea_inode)
1095 {
1096 return ext4_xattr_inode_update_ref(handle, ea_inode, -1);
1097 }
1098
1099 static int ext4_xattr_inode_inc_ref_all(handle_t *handle, struct inode *parent,
1100 struct ext4_xattr_entry *first)
1101 {
1102 struct inode *ea_inode;
1103 struct ext4_xattr_entry *entry;
1104 struct ext4_xattr_entry *failed_entry;
1105 unsigned int ea_ino;
1106 int err, saved_err;
1107
1108 for (entry = first; !IS_LAST_ENTRY(entry);
1109 entry = EXT4_XATTR_NEXT(entry)) {
1110 if (!entry->e_value_inum)
1111 continue;
1112 ea_ino = le32_to_cpu(entry->e_value_inum);
1113 err = ext4_xattr_inode_iget(parent, ea_ino,
1114 le32_to_cpu(entry->e_hash),
1115 &ea_inode);
1116 if (err)
1117 goto cleanup;
1118 err = ext4_xattr_inode_inc_ref(handle, ea_inode);
1119 if (err) {
1120 ext4_warning_inode(ea_inode, "inc ref error %d", err);
1121 iput(ea_inode);
1122 goto cleanup;
1123 }
1124 iput(ea_inode);
1125 }
1126 return 0;
1127
1128 cleanup:
1129 saved_err = err;
1130 failed_entry = entry;
1131
1132 for (entry = first; entry != failed_entry;
1133 entry = EXT4_XATTR_NEXT(entry)) {
1134 if (!entry->e_value_inum)
1135 continue;
1136 ea_ino = le32_to_cpu(entry->e_value_inum);
1137 err = ext4_xattr_inode_iget(parent, ea_ino,
1138 le32_to_cpu(entry->e_hash),
1139 &ea_inode);
1140 if (err) {
1141 ext4_warning(parent->i_sb,
1142 "cleanup ea_ino %u iget error %d", ea_ino,
1143 err);
1144 continue;
1145 }
1146 err = ext4_xattr_inode_dec_ref(handle, ea_inode);
1147 if (err)
1148 ext4_warning_inode(ea_inode, "cleanup dec ref error %d",
1149 err);
1150 iput(ea_inode);
1151 }
1152 return saved_err;
1153 }
1154
1155 static void
1156 ext4_xattr_inode_dec_ref_all(handle_t *handle, struct inode *parent,
1157 struct buffer_head *bh,
1158 struct ext4_xattr_entry *first, bool block_csum,
1159 struct ext4_xattr_inode_array **ea_inode_array,
1160 int extra_credits, bool skip_quota)
1161 {
1162 struct inode *ea_inode;
1163 struct ext4_xattr_entry *entry;
1164 bool dirty = false;
1165 unsigned int ea_ino;
1166 int err;
1167 int credits;
1168
1169 /* One credit for dec ref on ea_inode, one for orphan list addition, */
1170 credits = 2 + extra_credits;
1171
1172 for (entry = first; !IS_LAST_ENTRY(entry);
1173 entry = EXT4_XATTR_NEXT(entry)) {
1174 if (!entry->e_value_inum)
1175 continue;
1176 ea_ino = le32_to_cpu(entry->e_value_inum);
1177 err = ext4_xattr_inode_iget(parent, ea_ino,
1178 le32_to_cpu(entry->e_hash),
1179 &ea_inode);
1180 if (err)
1181 continue;
1182
1183 err = ext4_expand_inode_array(ea_inode_array, ea_inode);
1184 if (err) {
1185 ext4_warning_inode(ea_inode,
1186 "Expand inode array err=%d", err);
1187 iput(ea_inode);
1188 continue;
1189 }
1190
1191 err = ext4_xattr_ensure_credits(handle, parent, credits, bh,
1192 dirty, block_csum);
1193 if (err) {
1194 ext4_warning_inode(ea_inode, "Ensure credits err=%d",
1195 err);
1196 continue;
1197 }
1198
1199 err = ext4_xattr_inode_dec_ref(handle, ea_inode);
1200 if (err) {
1201 ext4_warning_inode(ea_inode, "ea_inode dec ref err=%d",
1202 err);
1203 continue;
1204 }
1205
1206 if (!skip_quota)
1207 ext4_xattr_inode_free_quota(parent, ea_inode,
1208 le32_to_cpu(entry->e_value_size));
1209
1210 /*
1211 * Forget about ea_inode within the same transaction that
1212 * decrements the ref count. This avoids duplicate decrements in
1213 * case the rest of the work spills over to subsequent
1214 * transactions.
1215 */
1216 entry->e_value_inum = 0;
1217 entry->e_value_size = 0;
1218
1219 dirty = true;
1220 }
1221
1222 if (dirty) {
1223 /*
1224 * Note that we are deliberately skipping csum calculation for
1225 * the final update because we do not expect any journal
1226 * restarts until xattr block is freed.
1227 */
1228
1229 err = ext4_handle_dirty_metadata(handle, NULL, bh);
1230 if (err)
1231 ext4_warning_inode(parent,
1232 "handle dirty metadata err=%d", err);
1233 }
1234 }
1235
1236 /*
1237 * Release the xattr block BH: If the reference count is > 1, decrement it;
1238 * otherwise free the block.
1239 */
1240 static void
1241 ext4_xattr_release_block(handle_t *handle, struct inode *inode,
1242 struct buffer_head *bh,
1243 struct ext4_xattr_inode_array **ea_inode_array,
1244 int extra_credits)
1245 {
1246 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
1247 u32 hash, ref;
1248 int error = 0;
1249
1250 BUFFER_TRACE(bh, "get_write_access");
1251 error = ext4_journal_get_write_access(handle, bh);
1252 if (error)
1253 goto out;
1254
1255 lock_buffer(bh);
1256 hash = le32_to_cpu(BHDR(bh)->h_hash);
1257 ref = le32_to_cpu(BHDR(bh)->h_refcount);
1258 if (ref == 1) {
1259 ea_bdebug(bh, "refcount now=0; freeing");
1260 /*
1261 * This must happen under buffer lock for
1262 * ext4_xattr_block_set() to reliably detect freed block
1263 */
1264 if (ea_block_cache)
1265 mb_cache_entry_delete(ea_block_cache, hash,
1266 bh->b_blocknr);
1267 get_bh(bh);
1268 unlock_buffer(bh);
1269
1270 if (ext4_has_feature_ea_inode(inode->i_sb))
1271 ext4_xattr_inode_dec_ref_all(handle, inode, bh,
1272 BFIRST(bh),
1273 true /* block_csum */,
1274 ea_inode_array,
1275 extra_credits,
1276 true /* skip_quota */);
1277 ext4_free_blocks(handle, inode, bh, 0, 1,
1278 EXT4_FREE_BLOCKS_METADATA |
1279 EXT4_FREE_BLOCKS_FORGET);
1280 } else {
1281 ref--;
1282 BHDR(bh)->h_refcount = cpu_to_le32(ref);
1283 if (ref == EXT4_XATTR_REFCOUNT_MAX - 1) {
1284 struct mb_cache_entry *ce;
1285
1286 if (ea_block_cache) {
1287 ce = mb_cache_entry_get(ea_block_cache, hash,
1288 bh->b_blocknr);
1289 if (ce) {
1290 ce->e_reusable = 1;
1291 mb_cache_entry_put(ea_block_cache, ce);
1292 }
1293 }
1294 }
1295
1296 ext4_xattr_block_csum_set(inode, bh);
1297 /*
1298 * Beware of this ugliness: Releasing of xattr block references
1299 * from different inodes can race and so we have to protect
1300 * from a race where someone else frees the block (and releases
1301 * its journal_head) before we are done dirtying the buffer. In
1302 * nojournal mode this race is harmless and we actually cannot
1303 * call ext4_handle_dirty_metadata() with locked buffer as
1304 * that function can call sync_dirty_buffer() so for that case
1305 * we handle the dirtying after unlocking the buffer.
1306 */
1307 if (ext4_handle_valid(handle))
1308 error = ext4_handle_dirty_metadata(handle, inode, bh);
1309 unlock_buffer(bh);
1310 if (!ext4_handle_valid(handle))
1311 error = ext4_handle_dirty_metadata(handle, inode, bh);
1312 if (IS_SYNC(inode))
1313 ext4_handle_sync(handle);
1314 dquot_free_block(inode, EXT4_C2B(EXT4_SB(inode->i_sb), 1));
1315 ea_bdebug(bh, "refcount now=%d; releasing",
1316 le32_to_cpu(BHDR(bh)->h_refcount));
1317 }
1318 out:
1319 ext4_std_error(inode->i_sb, error);
1320 return;
1321 }
1322
1323 /*
1324 * Find the available free space for EAs. This also returns the total number of
1325 * bytes used by EA entries.
1326 */
1327 static size_t ext4_xattr_free_space(struct ext4_xattr_entry *last,
1328 size_t *min_offs, void *base, int *total)
1329 {
1330 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
1331 if (!last->e_value_inum && last->e_value_size) {
1332 size_t offs = le16_to_cpu(last->e_value_offs);
1333 if (offs < *min_offs)
1334 *min_offs = offs;
1335 }
1336 if (total)
1337 *total += EXT4_XATTR_LEN(last->e_name_len);
1338 }
1339 return (*min_offs - ((void *)last - base) - sizeof(__u32));
1340 }
1341
1342 /*
1343 * Write the value of the EA in an inode.
1344 */
1345 static int ext4_xattr_inode_write(handle_t *handle, struct inode *ea_inode,
1346 const void *buf, int bufsize)
1347 {
1348 struct buffer_head *bh = NULL;
1349 unsigned long block = 0;
1350 int blocksize = ea_inode->i_sb->s_blocksize;
1351 int max_blocks = (bufsize + blocksize - 1) >> ea_inode->i_blkbits;
1352 int csize, wsize = 0;
1353 int ret = 0;
1354 int retries = 0;
1355
1356 retry:
1357 while (ret >= 0 && ret < max_blocks) {
1358 struct ext4_map_blocks map;
1359 map.m_lblk = block += ret;
1360 map.m_len = max_blocks -= ret;
1361
1362 ret = ext4_map_blocks(handle, ea_inode, &map,
1363 EXT4_GET_BLOCKS_CREATE);
1364 if (ret <= 0) {
1365 ext4_mark_inode_dirty(handle, ea_inode);
1366 if (ret == -ENOSPC &&
1367 ext4_should_retry_alloc(ea_inode->i_sb, &retries)) {
1368 ret = 0;
1369 goto retry;
1370 }
1371 break;
1372 }
1373 }
1374
1375 if (ret < 0)
1376 return ret;
1377
1378 block = 0;
1379 while (wsize < bufsize) {
1380 if (bh != NULL)
1381 brelse(bh);
1382 csize = (bufsize - wsize) > blocksize ? blocksize :
1383 bufsize - wsize;
1384 bh = ext4_getblk(handle, ea_inode, block, 0);
1385 if (IS_ERR(bh))
1386 return PTR_ERR(bh);
1387 if (!bh) {
1388 WARN_ON_ONCE(1);
1389 EXT4_ERROR_INODE(ea_inode,
1390 "ext4_getblk() return bh = NULL");
1391 return -EFSCORRUPTED;
1392 }
1393 ret = ext4_journal_get_write_access(handle, bh);
1394 if (ret)
1395 goto out;
1396
1397 memcpy(bh->b_data, buf, csize);
1398 set_buffer_uptodate(bh);
1399 ext4_handle_dirty_metadata(handle, ea_inode, bh);
1400
1401 buf += csize;
1402 wsize += csize;
1403 block += 1;
1404 }
1405
1406 inode_lock(ea_inode);
1407 i_size_write(ea_inode, wsize);
1408 ext4_update_i_disksize(ea_inode, wsize);
1409 inode_unlock(ea_inode);
1410
1411 ext4_mark_inode_dirty(handle, ea_inode);
1412
1413 out:
1414 brelse(bh);
1415
1416 return ret;
1417 }
1418
1419 /*
1420 * Create an inode to store the value of a large EA.
1421 */
1422 static struct inode *ext4_xattr_inode_create(handle_t *handle,
1423 struct inode *inode, u32 hash)
1424 {
1425 struct inode *ea_inode = NULL;
1426 uid_t owner[2] = { i_uid_read(inode), i_gid_read(inode) };
1427 int err;
1428
1429 /*
1430 * Let the next inode be the goal, so we try and allocate the EA inode
1431 * in the same group, or nearby one.
1432 */
1433 ea_inode = ext4_new_inode(handle, inode->i_sb->s_root->d_inode,
1434 S_IFREG | 0600, NULL, inode->i_ino + 1, owner,
1435 EXT4_EA_INODE_FL);
1436 if (!IS_ERR(ea_inode)) {
1437 ea_inode->i_op = &ext4_file_inode_operations;
1438 ea_inode->i_fop = &ext4_file_operations;
1439 ext4_set_aops(ea_inode);
1440 ext4_xattr_inode_set_class(ea_inode);
1441 unlock_new_inode(ea_inode);
1442 ext4_xattr_inode_set_ref(ea_inode, 1);
1443 ext4_xattr_inode_set_hash(ea_inode, hash);
1444 err = ext4_mark_inode_dirty(handle, ea_inode);
1445 if (!err)
1446 err = ext4_inode_attach_jinode(ea_inode);
1447 if (err) {
1448 iput(ea_inode);
1449 return ERR_PTR(err);
1450 }
1451
1452 /*
1453 * Xattr inodes are shared therefore quota charging is performed
1454 * at a higher level.
1455 */
1456 dquot_free_inode(ea_inode);
1457 dquot_drop(ea_inode);
1458 inode_lock(ea_inode);
1459 ea_inode->i_flags |= S_NOQUOTA;
1460 inode_unlock(ea_inode);
1461 }
1462
1463 return ea_inode;
1464 }
1465
1466 static struct inode *
1467 ext4_xattr_inode_cache_find(struct inode *inode, const void *value,
1468 size_t value_len, u32 hash)
1469 {
1470 struct inode *ea_inode;
1471 struct mb_cache_entry *ce;
1472 struct mb_cache *ea_inode_cache = EA_INODE_CACHE(inode);
1473 void *ea_data;
1474
1475 if (!ea_inode_cache)
1476 return NULL;
1477
1478 ce = mb_cache_entry_find_first(ea_inode_cache, hash);
1479 if (!ce)
1480 return NULL;
1481
1482 ea_data = ext4_kvmalloc(value_len, GFP_NOFS);
1483 if (!ea_data) {
1484 mb_cache_entry_put(ea_inode_cache, ce);
1485 return NULL;
1486 }
1487
1488 while (ce) {
1489 ea_inode = ext4_iget(inode->i_sb, ce->e_value);
1490 if (!IS_ERR(ea_inode) &&
1491 !is_bad_inode(ea_inode) &&
1492 (EXT4_I(ea_inode)->i_flags & EXT4_EA_INODE_FL) &&
1493 i_size_read(ea_inode) == value_len &&
1494 !ext4_xattr_inode_read(ea_inode, ea_data, value_len) &&
1495 !ext4_xattr_inode_verify_hashes(ea_inode, NULL, ea_data,
1496 value_len) &&
1497 !memcmp(value, ea_data, value_len)) {
1498 mb_cache_entry_touch(ea_inode_cache, ce);
1499 mb_cache_entry_put(ea_inode_cache, ce);
1500 kvfree(ea_data);
1501 return ea_inode;
1502 }
1503
1504 if (!IS_ERR(ea_inode))
1505 iput(ea_inode);
1506 ce = mb_cache_entry_find_next(ea_inode_cache, ce);
1507 }
1508 kvfree(ea_data);
1509 return NULL;
1510 }
1511
1512 /*
1513 * Add value of the EA in an inode.
1514 */
1515 static int ext4_xattr_inode_lookup_create(handle_t *handle, struct inode *inode,
1516 const void *value, size_t value_len,
1517 struct inode **ret_inode)
1518 {
1519 struct inode *ea_inode;
1520 u32 hash;
1521 int err;
1522
1523 hash = ext4_xattr_inode_hash(EXT4_SB(inode->i_sb), value, value_len);
1524 ea_inode = ext4_xattr_inode_cache_find(inode, value, value_len, hash);
1525 if (ea_inode) {
1526 err = ext4_xattr_inode_inc_ref(handle, ea_inode);
1527 if (err) {
1528 iput(ea_inode);
1529 return err;
1530 }
1531
1532 *ret_inode = ea_inode;
1533 return 0;
1534 }
1535
1536 /* Create an inode for the EA value */
1537 ea_inode = ext4_xattr_inode_create(handle, inode, hash);
1538 if (IS_ERR(ea_inode))
1539 return PTR_ERR(ea_inode);
1540
1541 err = ext4_xattr_inode_write(handle, ea_inode, value, value_len);
1542 if (err) {
1543 ext4_xattr_inode_dec_ref(handle, ea_inode);
1544 iput(ea_inode);
1545 return err;
1546 }
1547
1548 if (EA_INODE_CACHE(inode))
1549 mb_cache_entry_create(EA_INODE_CACHE(inode), GFP_NOFS, hash,
1550 ea_inode->i_ino, true /* reusable */);
1551
1552 *ret_inode = ea_inode;
1553 return 0;
1554 }
1555
1556 /*
1557 * Reserve min(block_size/8, 1024) bytes for xattr entries/names if ea_inode
1558 * feature is enabled.
1559 */
1560 #define EXT4_XATTR_BLOCK_RESERVE(inode) min(i_blocksize(inode)/8, 1024U)
1561
1562 static int ext4_xattr_set_entry(struct ext4_xattr_info *i,
1563 struct ext4_xattr_search *s,
1564 handle_t *handle, struct inode *inode,
1565 bool is_block)
1566 {
1567 struct ext4_xattr_entry *last, *next;
1568 struct ext4_xattr_entry *here = s->here;
1569 size_t min_offs = s->end - s->base, name_len = strlen(i->name);
1570 int in_inode = i->in_inode;
1571 struct inode *old_ea_inode = NULL;
1572 struct inode *new_ea_inode = NULL;
1573 size_t old_size, new_size;
1574 int ret;
1575
1576 /* Space used by old and new values. */
1577 old_size = (!s->not_found && !here->e_value_inum) ?
1578 EXT4_XATTR_SIZE(le32_to_cpu(here->e_value_size)) : 0;
1579 new_size = (i->value && !in_inode) ? EXT4_XATTR_SIZE(i->value_len) : 0;
1580
1581 /*
1582 * Optimization for the simple case when old and new values have the
1583 * same padded sizes. Not applicable if external inodes are involved.
1584 */
1585 if (new_size && new_size == old_size) {
1586 size_t offs = le16_to_cpu(here->e_value_offs);
1587 void *val = s->base + offs;
1588
1589 here->e_value_size = cpu_to_le32(i->value_len);
1590 if (i->value == EXT4_ZERO_XATTR_VALUE) {
1591 memset(val, 0, new_size);
1592 } else {
1593 memcpy(val, i->value, i->value_len);
1594 /* Clear padding bytes. */
1595 memset(val + i->value_len, 0, new_size - i->value_len);
1596 }
1597 goto update_hash;
1598 }
1599
1600 /* Compute min_offs and last. */
1601 last = s->first;
1602 for (; !IS_LAST_ENTRY(last); last = next) {
1603 next = EXT4_XATTR_NEXT(last);
1604 if ((void *)next >= s->end) {
1605 EXT4_ERROR_INODE(inode, "corrupted xattr entries");
1606 ret = -EFSCORRUPTED;
1607 goto out;
1608 }
1609 if (!last->e_value_inum && last->e_value_size) {
1610 size_t offs = le16_to_cpu(last->e_value_offs);
1611 if (offs < min_offs)
1612 min_offs = offs;
1613 }
1614 }
1615
1616 /* Check whether we have enough space. */
1617 if (i->value) {
1618 size_t free;
1619
1620 free = min_offs - ((void *)last - s->base) - sizeof(__u32);
1621 if (!s->not_found)
1622 free += EXT4_XATTR_LEN(name_len) + old_size;
1623
1624 if (free < EXT4_XATTR_LEN(name_len) + new_size) {
1625 ret = -ENOSPC;
1626 goto out;
1627 }
1628
1629 /*
1630 * If storing the value in an external inode is an option,
1631 * reserve space for xattr entries/names in the external
1632 * attribute block so that a long value does not occupy the
1633 * whole space and prevent futher entries being added.
1634 */
1635 if (ext4_has_feature_ea_inode(inode->i_sb) &&
1636 new_size && is_block &&
1637 (min_offs + old_size - new_size) <
1638 EXT4_XATTR_BLOCK_RESERVE(inode)) {
1639 ret = -ENOSPC;
1640 goto out;
1641 }
1642 }
1643
1644 /*
1645 * Getting access to old and new ea inodes is subject to failures.
1646 * Finish that work before doing any modifications to the xattr data.
1647 */
1648 if (!s->not_found && here->e_value_inum) {
1649 ret = ext4_xattr_inode_iget(inode,
1650 le32_to_cpu(here->e_value_inum),
1651 le32_to_cpu(here->e_hash),
1652 &old_ea_inode);
1653 if (ret) {
1654 old_ea_inode = NULL;
1655 goto out;
1656 }
1657 }
1658 if (i->value && in_inode) {
1659 WARN_ON_ONCE(!i->value_len);
1660
1661 ret = ext4_xattr_inode_alloc_quota(inode, i->value_len);
1662 if (ret)
1663 goto out;
1664
1665 ret = ext4_xattr_inode_lookup_create(handle, inode, i->value,
1666 i->value_len,
1667 &new_ea_inode);
1668 if (ret) {
1669 new_ea_inode = NULL;
1670 ext4_xattr_inode_free_quota(inode, NULL, i->value_len);
1671 goto out;
1672 }
1673 }
1674
1675 if (old_ea_inode) {
1676 /* We are ready to release ref count on the old_ea_inode. */
1677 ret = ext4_xattr_inode_dec_ref(handle, old_ea_inode);
1678 if (ret) {
1679 /* Release newly required ref count on new_ea_inode. */
1680 if (new_ea_inode) {
1681 int err;
1682
1683 err = ext4_xattr_inode_dec_ref(handle,
1684 new_ea_inode);
1685 if (err)
1686 ext4_warning_inode(new_ea_inode,
1687 "dec ref new_ea_inode err=%d",
1688 err);
1689 ext4_xattr_inode_free_quota(inode, new_ea_inode,
1690 i->value_len);
1691 }
1692 goto out;
1693 }
1694
1695 ext4_xattr_inode_free_quota(inode, old_ea_inode,
1696 le32_to_cpu(here->e_value_size));
1697 }
1698
1699 /* No failures allowed past this point. */
1700
1701 if (!s->not_found && here->e_value_size && here->e_value_offs) {
1702 /* Remove the old value. */
1703 void *first_val = s->base + min_offs;
1704 size_t offs = le16_to_cpu(here->e_value_offs);
1705 void *val = s->base + offs;
1706
1707 memmove(first_val + old_size, first_val, val - first_val);
1708 memset(first_val, 0, old_size);
1709 min_offs += old_size;
1710
1711 /* Adjust all value offsets. */
1712 last = s->first;
1713 while (!IS_LAST_ENTRY(last)) {
1714 size_t o = le16_to_cpu(last->e_value_offs);
1715
1716 if (!last->e_value_inum &&
1717 last->e_value_size && o < offs)
1718 last->e_value_offs = cpu_to_le16(o + old_size);
1719 last = EXT4_XATTR_NEXT(last);
1720 }
1721 }
1722
1723 if (!i->value) {
1724 /* Remove old name. */
1725 size_t size = EXT4_XATTR_LEN(name_len);
1726
1727 last = ENTRY((void *)last - size);
1728 memmove(here, (void *)here + size,
1729 (void *)last - (void *)here + sizeof(__u32));
1730 memset(last, 0, size);
1731 } else if (s->not_found) {
1732 /* Insert new name. */
1733 size_t size = EXT4_XATTR_LEN(name_len);
1734 size_t rest = (void *)last - (void *)here + sizeof(__u32);
1735
1736 memmove((void *)here + size, here, rest);
1737 memset(here, 0, size);
1738 here->e_name_index = i->name_index;
1739 here->e_name_len = name_len;
1740 memcpy(here->e_name, i->name, name_len);
1741 } else {
1742 /* This is an update, reset value info. */
1743 here->e_value_inum = 0;
1744 here->e_value_offs = 0;
1745 here->e_value_size = 0;
1746 }
1747
1748 if (i->value) {
1749 /* Insert new value. */
1750 if (in_inode) {
1751 here->e_value_inum = cpu_to_le32(new_ea_inode->i_ino);
1752 } else if (i->value_len) {
1753 void *val = s->base + min_offs - new_size;
1754
1755 here->e_value_offs = cpu_to_le16(min_offs - new_size);
1756 if (i->value == EXT4_ZERO_XATTR_VALUE) {
1757 memset(val, 0, new_size);
1758 } else {
1759 memcpy(val, i->value, i->value_len);
1760 /* Clear padding bytes. */
1761 memset(val + i->value_len, 0,
1762 new_size - i->value_len);
1763 }
1764 }
1765 here->e_value_size = cpu_to_le32(i->value_len);
1766 }
1767
1768 update_hash:
1769 if (i->value) {
1770 __le32 hash = 0;
1771
1772 /* Entry hash calculation. */
1773 if (in_inode) {
1774 __le32 crc32c_hash;
1775
1776 /*
1777 * Feed crc32c hash instead of the raw value for entry
1778 * hash calculation. This is to avoid walking
1779 * potentially long value buffer again.
1780 */
1781 crc32c_hash = cpu_to_le32(
1782 ext4_xattr_inode_get_hash(new_ea_inode));
1783 hash = ext4_xattr_hash_entry(here->e_name,
1784 here->e_name_len,
1785 &crc32c_hash, 1);
1786 } else if (is_block) {
1787 __le32 *value = s->base + le16_to_cpu(
1788 here->e_value_offs);
1789
1790 hash = ext4_xattr_hash_entry(here->e_name,
1791 here->e_name_len, value,
1792 new_size >> 2);
1793 }
1794 here->e_hash = hash;
1795 }
1796
1797 if (is_block)
1798 ext4_xattr_rehash((struct ext4_xattr_header *)s->base);
1799
1800 ret = 0;
1801 out:
1802 iput(old_ea_inode);
1803 iput(new_ea_inode);
1804 return ret;
1805 }
1806
1807 struct ext4_xattr_block_find {
1808 struct ext4_xattr_search s;
1809 struct buffer_head *bh;
1810 };
1811
1812 static int
1813 ext4_xattr_block_find(struct inode *inode, struct ext4_xattr_info *i,
1814 struct ext4_xattr_block_find *bs)
1815 {
1816 struct super_block *sb = inode->i_sb;
1817 int error;
1818
1819 ea_idebug(inode, "name=%d.%s, value=%p, value_len=%ld",
1820 i->name_index, i->name, i->value, (long)i->value_len);
1821
1822 if (EXT4_I(inode)->i_file_acl) {
1823 /* The inode already has an extended attribute block. */
1824 bs->bh = sb_bread(sb, EXT4_I(inode)->i_file_acl);
1825 error = -EIO;
1826 if (!bs->bh)
1827 goto cleanup;
1828 ea_bdebug(bs->bh, "b_count=%d, refcount=%d",
1829 atomic_read(&(bs->bh->b_count)),
1830 le32_to_cpu(BHDR(bs->bh)->h_refcount));
1831 error = ext4_xattr_check_block(inode, bs->bh);
1832 if (error)
1833 goto cleanup;
1834 /* Find the named attribute. */
1835 bs->s.base = BHDR(bs->bh);
1836 bs->s.first = BFIRST(bs->bh);
1837 bs->s.end = bs->bh->b_data + bs->bh->b_size;
1838 bs->s.here = bs->s.first;
1839 error = xattr_find_entry(inode, &bs->s.here, bs->s.end,
1840 i->name_index, i->name, 1);
1841 if (error && error != -ENODATA)
1842 goto cleanup;
1843 bs->s.not_found = error;
1844 }
1845 error = 0;
1846
1847 cleanup:
1848 return error;
1849 }
1850
1851 static int
1852 ext4_xattr_block_set(handle_t *handle, struct inode *inode,
1853 struct ext4_xattr_info *i,
1854 struct ext4_xattr_block_find *bs)
1855 {
1856 struct super_block *sb = inode->i_sb;
1857 struct buffer_head *new_bh = NULL;
1858 struct ext4_xattr_search s_copy = bs->s;
1859 struct ext4_xattr_search *s = &s_copy;
1860 struct mb_cache_entry *ce = NULL;
1861 int error = 0;
1862 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
1863 struct inode *ea_inode = NULL, *tmp_inode;
1864 size_t old_ea_inode_quota = 0;
1865 unsigned int ea_ino;
1866
1867
1868 #define header(x) ((struct ext4_xattr_header *)(x))
1869
1870 if (s->base) {
1871 BUFFER_TRACE(bs->bh, "get_write_access");
1872 error = ext4_journal_get_write_access(handle, bs->bh);
1873 if (error)
1874 goto cleanup;
1875 lock_buffer(bs->bh);
1876
1877 if (header(s->base)->h_refcount == cpu_to_le32(1)) {
1878 __u32 hash = le32_to_cpu(BHDR(bs->bh)->h_hash);
1879
1880 /*
1881 * This must happen under buffer lock for
1882 * ext4_xattr_block_set() to reliably detect modified
1883 * block
1884 */
1885 if (ea_block_cache)
1886 mb_cache_entry_delete(ea_block_cache, hash,
1887 bs->bh->b_blocknr);
1888 ea_bdebug(bs->bh, "modifying in-place");
1889 error = ext4_xattr_set_entry(i, s, handle, inode,
1890 true /* is_block */);
1891 ext4_xattr_block_csum_set(inode, bs->bh);
1892 unlock_buffer(bs->bh);
1893 if (error == -EFSCORRUPTED)
1894 goto bad_block;
1895 if (!error)
1896 error = ext4_handle_dirty_metadata(handle,
1897 inode,
1898 bs->bh);
1899 if (error)
1900 goto cleanup;
1901 goto inserted;
1902 } else {
1903 int offset = (char *)s->here - bs->bh->b_data;
1904
1905 unlock_buffer(bs->bh);
1906 ea_bdebug(bs->bh, "cloning");
1907 s->base = kmalloc(bs->bh->b_size, GFP_NOFS);
1908 error = -ENOMEM;
1909 if (s->base == NULL)
1910 goto cleanup;
1911 memcpy(s->base, BHDR(bs->bh), bs->bh->b_size);
1912 s->first = ENTRY(header(s->base)+1);
1913 header(s->base)->h_refcount = cpu_to_le32(1);
1914 s->here = ENTRY(s->base + offset);
1915 s->end = s->base + bs->bh->b_size;
1916
1917 /*
1918 * If existing entry points to an xattr inode, we need
1919 * to prevent ext4_xattr_set_entry() from decrementing
1920 * ref count on it because the reference belongs to the
1921 * original block. In this case, make the entry look
1922 * like it has an empty value.
1923 */
1924 if (!s->not_found && s->here->e_value_inum) {
1925 ea_ino = le32_to_cpu(s->here->e_value_inum);
1926 error = ext4_xattr_inode_iget(inode, ea_ino,
1927 le32_to_cpu(s->here->e_hash),
1928 &tmp_inode);
1929 if (error)
1930 goto cleanup;
1931
1932 if (!ext4_test_inode_state(tmp_inode,
1933 EXT4_STATE_LUSTRE_EA_INODE)) {
1934 /*
1935 * Defer quota free call for previous
1936 * inode until success is guaranteed.
1937 */
1938 old_ea_inode_quota = le32_to_cpu(
1939 s->here->e_value_size);
1940 }
1941 iput(tmp_inode);
1942
1943 s->here->e_value_inum = 0;
1944 s->here->e_value_size = 0;
1945 }
1946 }
1947 } else {
1948 /* Allocate a buffer where we construct the new block. */
1949 s->base = kzalloc(sb->s_blocksize, GFP_NOFS);
1950 /* assert(header == s->base) */
1951 error = -ENOMEM;
1952 if (s->base == NULL)
1953 goto cleanup;
1954 header(s->base)->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
1955 header(s->base)->h_blocks = cpu_to_le32(1);
1956 header(s->base)->h_refcount = cpu_to_le32(1);
1957 s->first = ENTRY(header(s->base)+1);
1958 s->here = ENTRY(header(s->base)+1);
1959 s->end = s->base + sb->s_blocksize;
1960 }
1961
1962 error = ext4_xattr_set_entry(i, s, handle, inode, true /* is_block */);
1963 if (error == -EFSCORRUPTED)
1964 goto bad_block;
1965 if (error)
1966 goto cleanup;
1967
1968 if (i->value && s->here->e_value_inum) {
1969 /*
1970 * A ref count on ea_inode has been taken as part of the call to
1971 * ext4_xattr_set_entry() above. We would like to drop this
1972 * extra ref but we have to wait until the xattr block is
1973 * initialized and has its own ref count on the ea_inode.
1974 */
1975 ea_ino = le32_to_cpu(s->here->e_value_inum);
1976 error = ext4_xattr_inode_iget(inode, ea_ino,
1977 le32_to_cpu(s->here->e_hash),
1978 &ea_inode);
1979 if (error) {
1980 ea_inode = NULL;
1981 goto cleanup;
1982 }
1983 }
1984
1985 inserted:
1986 if (!IS_LAST_ENTRY(s->first)) {
1987 new_bh = ext4_xattr_block_cache_find(inode, header(s->base),
1988 &ce);
1989 if (new_bh) {
1990 /* We found an identical block in the cache. */
1991 if (new_bh == bs->bh)
1992 ea_bdebug(new_bh, "keeping");
1993 else {
1994 u32 ref;
1995
1996 WARN_ON_ONCE(dquot_initialize_needed(inode));
1997
1998 /* The old block is released after updating
1999 the inode. */
2000 error = dquot_alloc_block(inode,
2001 EXT4_C2B(EXT4_SB(sb), 1));
2002 if (error)
2003 goto cleanup;
2004 BUFFER_TRACE(new_bh, "get_write_access");
2005 error = ext4_journal_get_write_access(handle,
2006 new_bh);
2007 if (error)
2008 goto cleanup_dquot;
2009 lock_buffer(new_bh);
2010 /*
2011 * We have to be careful about races with
2012 * freeing, rehashing or adding references to
2013 * xattr block. Once we hold buffer lock xattr
2014 * block's state is stable so we can check
2015 * whether the block got freed / rehashed or
2016 * not. Since we unhash mbcache entry under
2017 * buffer lock when freeing / rehashing xattr
2018 * block, checking whether entry is still
2019 * hashed is reliable. Same rules hold for
2020 * e_reusable handling.
2021 */
2022 if (hlist_bl_unhashed(&ce->e_hash_list) ||
2023 !ce->e_reusable) {
2024 /*
2025 * Undo everything and check mbcache
2026 * again.
2027 */
2028 unlock_buffer(new_bh);
2029 dquot_free_block(inode,
2030 EXT4_C2B(EXT4_SB(sb),
2031 1));
2032 brelse(new_bh);
2033 mb_cache_entry_put(ea_block_cache, ce);
2034 ce = NULL;
2035 new_bh = NULL;
2036 goto inserted;
2037 }
2038 ref = le32_to_cpu(BHDR(new_bh)->h_refcount) + 1;
2039 BHDR(new_bh)->h_refcount = cpu_to_le32(ref);
2040 if (ref >= EXT4_XATTR_REFCOUNT_MAX)
2041 ce->e_reusable = 0;
2042 ea_bdebug(new_bh, "reusing; refcount now=%d",
2043 ref);
2044 ext4_xattr_block_csum_set(inode, new_bh);
2045 unlock_buffer(new_bh);
2046 error = ext4_handle_dirty_metadata(handle,
2047 inode,
2048 new_bh);
2049 if (error)
2050 goto cleanup_dquot;
2051 }
2052 mb_cache_entry_touch(ea_block_cache, ce);
2053 mb_cache_entry_put(ea_block_cache, ce);
2054 ce = NULL;
2055 } else if (bs->bh && s->base == bs->bh->b_data) {
2056 /* We were modifying this block in-place. */
2057 ea_bdebug(bs->bh, "keeping this block");
2058 ext4_xattr_block_cache_insert(ea_block_cache, bs->bh);
2059 new_bh = bs->bh;
2060 get_bh(new_bh);
2061 } else {
2062 /* We need to allocate a new block */
2063 ext4_fsblk_t goal, block;
2064
2065 WARN_ON_ONCE(dquot_initialize_needed(inode));
2066
2067 goal = ext4_group_first_block_no(sb,
2068 EXT4_I(inode)->i_block_group);
2069
2070 /* non-extent files can't have physical blocks past 2^32 */
2071 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
2072 goal = goal & EXT4_MAX_BLOCK_FILE_PHYS;
2073
2074 block = ext4_new_meta_blocks(handle, inode, goal, 0,
2075 NULL, &error);
2076 if (error)
2077 goto cleanup;
2078
2079 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
2080 BUG_ON(block > EXT4_MAX_BLOCK_FILE_PHYS);
2081
2082 ea_idebug(inode, "creating block %llu",
2083 (unsigned long long)block);
2084
2085 new_bh = sb_getblk(sb, block);
2086 if (unlikely(!new_bh)) {
2087 error = -ENOMEM;
2088 getblk_failed:
2089 ext4_free_blocks(handle, inode, NULL, block, 1,
2090 EXT4_FREE_BLOCKS_METADATA);
2091 goto cleanup;
2092 }
2093 error = ext4_xattr_inode_inc_ref_all(handle, inode,
2094 ENTRY(header(s->base)+1));
2095 if (error)
2096 goto getblk_failed;
2097 if (ea_inode) {
2098 /* Drop the extra ref on ea_inode. */
2099 error = ext4_xattr_inode_dec_ref(handle,
2100 ea_inode);
2101 if (error)
2102 ext4_warning_inode(ea_inode,
2103 "dec ref error=%d",
2104 error);
2105 iput(ea_inode);
2106 ea_inode = NULL;
2107 }
2108
2109 lock_buffer(new_bh);
2110 error = ext4_journal_get_create_access(handle, new_bh);
2111 if (error) {
2112 unlock_buffer(new_bh);
2113 error = -EIO;
2114 goto getblk_failed;
2115 }
2116 memcpy(new_bh->b_data, s->base, new_bh->b_size);
2117 ext4_xattr_block_csum_set(inode, new_bh);
2118 set_buffer_uptodate(new_bh);
2119 unlock_buffer(new_bh);
2120 ext4_xattr_block_cache_insert(ea_block_cache, new_bh);
2121 error = ext4_handle_dirty_metadata(handle, inode,
2122 new_bh);
2123 if (error)
2124 goto cleanup;
2125 }
2126 }
2127
2128 if (old_ea_inode_quota)
2129 ext4_xattr_inode_free_quota(inode, NULL, old_ea_inode_quota);
2130
2131 /* Update the inode. */
2132 EXT4_I(inode)->i_file_acl = new_bh ? new_bh->b_blocknr : 0;
2133
2134 /* Drop the previous xattr block. */
2135 if (bs->bh && bs->bh != new_bh) {
2136 struct ext4_xattr_inode_array *ea_inode_array = NULL;
2137
2138 ext4_xattr_release_block(handle, inode, bs->bh,
2139 &ea_inode_array,
2140 0 /* extra_credits */);
2141 ext4_xattr_inode_array_free(ea_inode_array);
2142 }
2143 error = 0;
2144
2145 cleanup:
2146 if (ea_inode) {
2147 int error2;
2148
2149 error2 = ext4_xattr_inode_dec_ref(handle, ea_inode);
2150 if (error2)
2151 ext4_warning_inode(ea_inode, "dec ref error=%d",
2152 error2);
2153
2154 /* If there was an error, revert the quota charge. */
2155 if (error)
2156 ext4_xattr_inode_free_quota(inode, ea_inode,
2157 i_size_read(ea_inode));
2158 iput(ea_inode);
2159 }
2160 if (ce)
2161 mb_cache_entry_put(ea_block_cache, ce);
2162 brelse(new_bh);
2163 if (!(bs->bh && s->base == bs->bh->b_data))
2164 kfree(s->base);
2165
2166 return error;
2167
2168 cleanup_dquot:
2169 dquot_free_block(inode, EXT4_C2B(EXT4_SB(sb), 1));
2170 goto cleanup;
2171
2172 bad_block:
2173 EXT4_ERROR_INODE(inode, "bad block %llu",
2174 EXT4_I(inode)->i_file_acl);
2175 goto cleanup;
2176
2177 #undef header
2178 }
2179
2180 int ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i,
2181 struct ext4_xattr_ibody_find *is)
2182 {
2183 struct ext4_xattr_ibody_header *header;
2184 struct ext4_inode *raw_inode;
2185 int error;
2186
2187 if (EXT4_I(inode)->i_extra_isize == 0)
2188 return 0;
2189 raw_inode = ext4_raw_inode(&is->iloc);
2190 header = IHDR(inode, raw_inode);
2191 is->s.base = is->s.first = IFIRST(header);
2192 is->s.here = is->s.first;
2193 is->s.end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
2194 if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
2195 error = xattr_check_inode(inode, header, is->s.end);
2196 if (error)
2197 return error;
2198 /* Find the named attribute. */
2199 error = xattr_find_entry(inode, &is->s.here, is->s.end,
2200 i->name_index, i->name, 0);
2201 if (error && error != -ENODATA)
2202 return error;
2203 is->s.not_found = error;
2204 }
2205 return 0;
2206 }
2207
2208 int ext4_xattr_ibody_inline_set(handle_t *handle, struct inode *inode,
2209 struct ext4_xattr_info *i,
2210 struct ext4_xattr_ibody_find *is)
2211 {
2212 struct ext4_xattr_ibody_header *header;
2213 struct ext4_xattr_search *s = &is->s;
2214 int error;
2215
2216 if (EXT4_I(inode)->i_extra_isize == 0)
2217 return -ENOSPC;
2218 error = ext4_xattr_set_entry(i, s, handle, inode, false /* is_block */);
2219 if (error)
2220 return error;
2221 header = IHDR(inode, ext4_raw_inode(&is->iloc));
2222 if (!IS_LAST_ENTRY(s->first)) {
2223 header->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
2224 ext4_set_inode_state(inode, EXT4_STATE_XATTR);
2225 } else {
2226 header->h_magic = cpu_to_le32(0);
2227 ext4_clear_inode_state(inode, EXT4_STATE_XATTR);
2228 }
2229 return 0;
2230 }
2231
2232 static int ext4_xattr_ibody_set(handle_t *handle, struct inode *inode,
2233 struct ext4_xattr_info *i,
2234 struct ext4_xattr_ibody_find *is)
2235 {
2236 struct ext4_xattr_ibody_header *header;
2237 struct ext4_xattr_search *s = &is->s;
2238 int error;
2239
2240 if (EXT4_I(inode)->i_extra_isize == 0)
2241 return -ENOSPC;
2242 error = ext4_xattr_set_entry(i, s, handle, inode, false /* is_block */);
2243 if (error)
2244 return error;
2245 header = IHDR(inode, ext4_raw_inode(&is->iloc));
2246 if (!IS_LAST_ENTRY(s->first)) {
2247 header->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
2248 ext4_set_inode_state(inode, EXT4_STATE_XATTR);
2249 } else {
2250 header->h_magic = cpu_to_le32(0);
2251 ext4_clear_inode_state(inode, EXT4_STATE_XATTR);
2252 }
2253 return 0;
2254 }
2255
2256 static int ext4_xattr_value_same(struct ext4_xattr_search *s,
2257 struct ext4_xattr_info *i)
2258 {
2259 void *value;
2260
2261 /* When e_value_inum is set the value is stored externally. */
2262 if (s->here->e_value_inum)
2263 return 0;
2264 if (le32_to_cpu(s->here->e_value_size) != i->value_len)
2265 return 0;
2266 value = ((void *)s->base) + le16_to_cpu(s->here->e_value_offs);
2267 return !memcmp(value, i->value, i->value_len);
2268 }
2269
2270 static struct buffer_head *ext4_xattr_get_block(struct inode *inode)
2271 {
2272 struct buffer_head *bh;
2273 int error;
2274
2275 if (!EXT4_I(inode)->i_file_acl)
2276 return NULL;
2277 bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl);
2278 if (!bh)
2279 return ERR_PTR(-EIO);
2280 error = ext4_xattr_check_block(inode, bh);
2281 if (error) {
2282 brelse(bh);
2283 return ERR_PTR(error);
2284 }
2285 return bh;
2286 }
2287
2288 /*
2289 * ext4_xattr_set_handle()
2290 *
2291 * Create, replace or remove an extended attribute for this inode. Value
2292 * is NULL to remove an existing extended attribute, and non-NULL to
2293 * either replace an existing extended attribute, or create a new extended
2294 * attribute. The flags XATTR_REPLACE and XATTR_CREATE
2295 * specify that an extended attribute must exist and must not exist
2296 * previous to the call, respectively.
2297 *
2298 * Returns 0, or a negative error number on failure.
2299 */
2300 int
2301 ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
2302 const char *name, const void *value, size_t value_len,
2303 int flags)
2304 {
2305 struct ext4_xattr_info i = {
2306 .name_index = name_index,
2307 .name = name,
2308 .value = value,
2309 .value_len = value_len,
2310 .in_inode = 0,
2311 };
2312 struct ext4_xattr_ibody_find is = {
2313 .s = { .not_found = -ENODATA, },
2314 };
2315 struct ext4_xattr_block_find bs = {
2316 .s = { .not_found = -ENODATA, },
2317 };
2318 int no_expand;
2319 int error;
2320
2321 if (!name)
2322 return -EINVAL;
2323 if (strlen(name) > 255)
2324 return -ERANGE;
2325
2326 ext4_write_lock_xattr(inode, &no_expand);
2327
2328 /* Check journal credits under write lock. */
2329 if (ext4_handle_valid(handle)) {
2330 struct buffer_head *bh;
2331 int credits;
2332
2333 bh = ext4_xattr_get_block(inode);
2334 if (IS_ERR(bh)) {
2335 error = PTR_ERR(bh);
2336 goto cleanup;
2337 }
2338
2339 credits = __ext4_xattr_set_credits(inode->i_sb, inode, bh,
2340 value_len,
2341 flags & XATTR_CREATE);
2342 brelse(bh);
2343
2344 if (!ext4_handle_has_enough_credits(handle, credits)) {
2345 error = -ENOSPC;
2346 goto cleanup;
2347 }
2348 }
2349
2350 error = ext4_reserve_inode_write(handle, inode, &is.iloc);
2351 if (error)
2352 goto cleanup;
2353
2354 if (ext4_test_inode_state(inode, EXT4_STATE_NEW)) {
2355 struct ext4_inode *raw_inode = ext4_raw_inode(&is.iloc);
2356 memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size);
2357 ext4_clear_inode_state(inode, EXT4_STATE_NEW);
2358 }
2359
2360 error = ext4_xattr_ibody_find(inode, &i, &is);
2361 if (error)
2362 goto cleanup;
2363 if (is.s.not_found)
2364 error = ext4_xattr_block_find(inode, &i, &bs);
2365 if (error)
2366 goto cleanup;
2367 if (is.s.not_found && bs.s.not_found) {
2368 error = -ENODATA;
2369 if (flags & XATTR_REPLACE)
2370 goto cleanup;
2371 error = 0;
2372 if (!value)
2373 goto cleanup;
2374 } else {
2375 error = -EEXIST;
2376 if (flags & XATTR_CREATE)
2377 goto cleanup;
2378 }
2379
2380 if (!value) {
2381 if (!is.s.not_found)
2382 error = ext4_xattr_ibody_set(handle, inode, &i, &is);
2383 else if (!bs.s.not_found)
2384 error = ext4_xattr_block_set(handle, inode, &i, &bs);
2385 } else {
2386 error = 0;
2387 /* Xattr value did not change? Save us some work and bail out */
2388 if (!is.s.not_found && ext4_xattr_value_same(&is.s, &i))
2389 goto cleanup;
2390 if (!bs.s.not_found && ext4_xattr_value_same(&bs.s, &i))
2391 goto cleanup;
2392
2393 if (ext4_has_feature_ea_inode(inode->i_sb) &&
2394 (EXT4_XATTR_SIZE(i.value_len) >
2395 EXT4_XATTR_MIN_LARGE_EA_SIZE(inode->i_sb->s_blocksize)))
2396 i.in_inode = 1;
2397 retry_inode:
2398 error = ext4_xattr_ibody_set(handle, inode, &i, &is);
2399 if (!error && !bs.s.not_found) {
2400 i.value = NULL;
2401 error = ext4_xattr_block_set(handle, inode, &i, &bs);
2402 } else if (error == -ENOSPC) {
2403 if (EXT4_I(inode)->i_file_acl && !bs.s.base) {
2404 brelse(bs.bh);
2405 bs.bh = NULL;
2406 error = ext4_xattr_block_find(inode, &i, &bs);
2407 if (error)
2408 goto cleanup;
2409 }
2410 error = ext4_xattr_block_set(handle, inode, &i, &bs);
2411 if (!error && !is.s.not_found) {
2412 i.value = NULL;
2413 error = ext4_xattr_ibody_set(handle, inode, &i,
2414 &is);
2415 } else if (error == -ENOSPC) {
2416 /*
2417 * Xattr does not fit in the block, store at
2418 * external inode if possible.
2419 */
2420 if (ext4_has_feature_ea_inode(inode->i_sb) &&
2421 !i.in_inode) {
2422 i.in_inode = 1;
2423 goto retry_inode;
2424 }
2425 }
2426 }
2427 }
2428 if (!error) {
2429 ext4_xattr_update_super_block(handle, inode->i_sb);
2430 inode->i_ctime = current_time(inode);
2431 if (!value)
2432 no_expand = 0;
2433 error = ext4_mark_iloc_dirty(handle, inode, &is.iloc);
2434 /*
2435 * The bh is consumed by ext4_mark_iloc_dirty, even with
2436 * error != 0.
2437 */
2438 is.iloc.bh = NULL;
2439 if (IS_SYNC(inode))
2440 ext4_handle_sync(handle);
2441 }
2442
2443 cleanup:
2444 brelse(is.iloc.bh);
2445 brelse(bs.bh);
2446 ext4_write_unlock_xattr(inode, &no_expand);
2447 return error;
2448 }
2449
2450 int ext4_xattr_set_credits(struct inode *inode, size_t value_len,
2451 bool is_create, int *credits)
2452 {
2453 struct buffer_head *bh;
2454 int err;
2455
2456 *credits = 0;
2457
2458 if (!EXT4_SB(inode->i_sb)->s_journal)
2459 return 0;
2460
2461 down_read(&EXT4_I(inode)->xattr_sem);
2462
2463 bh = ext4_xattr_get_block(inode);
2464 if (IS_ERR(bh)) {
2465 err = PTR_ERR(bh);
2466 } else {
2467 *credits = __ext4_xattr_set_credits(inode->i_sb, inode, bh,
2468 value_len, is_create);
2469 brelse(bh);
2470 err = 0;
2471 }
2472
2473 up_read(&EXT4_I(inode)->xattr_sem);
2474 return err;
2475 }
2476
2477 /*
2478 * ext4_xattr_set()
2479 *
2480 * Like ext4_xattr_set_handle, but start from an inode. This extended
2481 * attribute modification is a filesystem transaction by itself.
2482 *
2483 * Returns 0, or a negative error number on failure.
2484 */
2485 int
2486 ext4_xattr_set(struct inode *inode, int name_index, const char *name,
2487 const void *value, size_t value_len, int flags)
2488 {
2489 handle_t *handle;
2490 struct super_block *sb = inode->i_sb;
2491 int error, retries = 0;
2492 int credits;
2493
2494 error = dquot_initialize(inode);
2495 if (error)
2496 return error;
2497
2498 retry:
2499 error = ext4_xattr_set_credits(inode, value_len, flags & XATTR_CREATE,
2500 &credits);
2501 if (error)
2502 return error;
2503
2504 handle = ext4_journal_start(inode, EXT4_HT_XATTR, credits);
2505 if (IS_ERR(handle)) {
2506 error = PTR_ERR(handle);
2507 } else {
2508 int error2;
2509
2510 error = ext4_xattr_set_handle(handle, inode, name_index, name,
2511 value, value_len, flags);
2512 error2 = ext4_journal_stop(handle);
2513 if (error == -ENOSPC &&
2514 ext4_should_retry_alloc(sb, &retries))
2515 goto retry;
2516 if (error == 0)
2517 error = error2;
2518 }
2519
2520 return error;
2521 }
2522
2523 /*
2524 * Shift the EA entries in the inode to create space for the increased
2525 * i_extra_isize.
2526 */
2527 static void ext4_xattr_shift_entries(struct ext4_xattr_entry *entry,
2528 int value_offs_shift, void *to,
2529 void *from, size_t n)
2530 {
2531 struct ext4_xattr_entry *last = entry;
2532 int new_offs;
2533
2534 /* We always shift xattr headers further thus offsets get lower */
2535 BUG_ON(value_offs_shift > 0);
2536
2537 /* Adjust the value offsets of the entries */
2538 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
2539 if (!last->e_value_inum && last->e_value_size) {
2540 new_offs = le16_to_cpu(last->e_value_offs) +
2541 value_offs_shift;
2542 last->e_value_offs = cpu_to_le16(new_offs);
2543 }
2544 }
2545 /* Shift the entries by n bytes */
2546 memmove(to, from, n);
2547 }
2548
2549 /*
2550 * Move xattr pointed to by 'entry' from inode into external xattr block
2551 */
2552 static int ext4_xattr_move_to_block(handle_t *handle, struct inode *inode,
2553 struct ext4_inode *raw_inode,
2554 struct ext4_xattr_entry *entry)
2555 {
2556 struct ext4_xattr_ibody_find *is = NULL;
2557 struct ext4_xattr_block_find *bs = NULL;
2558 char *buffer = NULL, *b_entry_name = NULL;
2559 size_t value_size = le32_to_cpu(entry->e_value_size);
2560 struct ext4_xattr_info i = {
2561 .value = NULL,
2562 .value_len = 0,
2563 .name_index = entry->e_name_index,
2564 .in_inode = !!entry->e_value_inum,
2565 };
2566 struct ext4_xattr_ibody_header *header = IHDR(inode, raw_inode);
2567 int error;
2568
2569 is = kzalloc(sizeof(struct ext4_xattr_ibody_find), GFP_NOFS);
2570 bs = kzalloc(sizeof(struct ext4_xattr_block_find), GFP_NOFS);
2571 buffer = kmalloc(value_size, GFP_NOFS);
2572 b_entry_name = kmalloc(entry->e_name_len + 1, GFP_NOFS);
2573 if (!is || !bs || !buffer || !b_entry_name) {
2574 error = -ENOMEM;
2575 goto out;
2576 }
2577
2578 is->s.not_found = -ENODATA;
2579 bs->s.not_found = -ENODATA;
2580 is->iloc.bh = NULL;
2581 bs->bh = NULL;
2582
2583 /* Save the entry name and the entry value */
2584 if (entry->e_value_inum) {
2585 error = ext4_xattr_inode_get(inode, entry, buffer, value_size);
2586 if (error)
2587 goto out;
2588 } else {
2589 size_t value_offs = le16_to_cpu(entry->e_value_offs);
2590 memcpy(buffer, (void *)IFIRST(header) + value_offs, value_size);
2591 }
2592
2593 memcpy(b_entry_name, entry->e_name, entry->e_name_len);
2594 b_entry_name[entry->e_name_len] = '\0';
2595 i.name = b_entry_name;
2596
2597 error = ext4_get_inode_loc(inode, &is->iloc);
2598 if (error)
2599 goto out;
2600
2601 error = ext4_xattr_ibody_find(inode, &i, is);
2602 if (error)
2603 goto out;
2604
2605 /* Remove the chosen entry from the inode */
2606 error = ext4_xattr_ibody_set(handle, inode, &i, is);
2607 if (error)
2608 goto out;
2609
2610 i.value = buffer;
2611 i.value_len = value_size;
2612 error = ext4_xattr_block_find(inode, &i, bs);
2613 if (error)
2614 goto out;
2615
2616 /* Add entry which was removed from the inode into the block */
2617 error = ext4_xattr_block_set(handle, inode, &i, bs);
2618 if (error)
2619 goto out;
2620 error = 0;
2621 out:
2622 kfree(b_entry_name);
2623 kfree(buffer);
2624 if (is)
2625 brelse(is->iloc.bh);
2626 if (bs)
2627 brelse(bs->bh);
2628 kfree(is);
2629 kfree(bs);
2630
2631 return error;
2632 }
2633
2634 static int ext4_xattr_make_inode_space(handle_t *handle, struct inode *inode,
2635 struct ext4_inode *raw_inode,
2636 int isize_diff, size_t ifree,
2637 size_t bfree, int *total_ino)
2638 {
2639 struct ext4_xattr_ibody_header *header = IHDR(inode, raw_inode);
2640 struct ext4_xattr_entry *small_entry;
2641 struct ext4_xattr_entry *entry;
2642 struct ext4_xattr_entry *last;
2643 unsigned int entry_size; /* EA entry size */
2644 unsigned int total_size; /* EA entry size + value size */
2645 unsigned int min_total_size;
2646 int error;
2647
2648 while (isize_diff > ifree) {
2649 entry = NULL;
2650 small_entry = NULL;
2651 min_total_size = ~0U;
2652 last = IFIRST(header);
2653 /* Find the entry best suited to be pushed into EA block */
2654 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
2655 /* never move system.data out of the inode */
2656 if ((last->e_name_len == 4) &&
2657 (last->e_name_index == EXT4_XATTR_INDEX_SYSTEM) &&
2658 !memcmp(last->e_name, "data", 4))
2659 continue;
2660 total_size = EXT4_XATTR_LEN(last->e_name_len);
2661 if (!last->e_value_inum)
2662 total_size += EXT4_XATTR_SIZE(
2663 le32_to_cpu(last->e_value_size));
2664 if (total_size <= bfree &&
2665 total_size < min_total_size) {
2666 if (total_size + ifree < isize_diff) {
2667 small_entry = last;
2668 } else {
2669 entry = last;
2670 min_total_size = total_size;
2671 }
2672 }
2673 }
2674
2675 if (entry == NULL) {
2676 if (small_entry == NULL)
2677 return -ENOSPC;
2678 entry = small_entry;
2679 }
2680
2681 entry_size = EXT4_XATTR_LEN(entry->e_name_len);
2682 total_size = entry_size;
2683 if (!entry->e_value_inum)
2684 total_size += EXT4_XATTR_SIZE(
2685 le32_to_cpu(entry->e_value_size));
2686 error = ext4_xattr_move_to_block(handle, inode, raw_inode,
2687 entry);
2688 if (error)
2689 return error;
2690
2691 *total_ino -= entry_size;
2692 ifree += total_size;
2693 bfree -= total_size;
2694 }
2695
2696 return 0;
2697 }
2698
2699 /*
2700 * Expand an inode by new_extra_isize bytes when EAs are present.
2701 * Returns 0 on success or negative error number on failure.
2702 */
2703 int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
2704 struct ext4_inode *raw_inode, handle_t *handle)
2705 {
2706 struct ext4_xattr_ibody_header *header;
2707 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2708 static unsigned int mnt_count;
2709 size_t min_offs;
2710 size_t ifree, bfree;
2711 int total_ino;
2712 void *base, *end;
2713 int error = 0, tried_min_extra_isize = 0;
2714 int s_min_extra_isize = le16_to_cpu(sbi->s_es->s_min_extra_isize);
2715 int isize_diff; /* How much do we need to grow i_extra_isize */
2716
2717 retry:
2718 isize_diff = new_extra_isize - EXT4_I(inode)->i_extra_isize;
2719 if (EXT4_I(inode)->i_extra_isize >= new_extra_isize)
2720 return 0;
2721
2722 header = IHDR(inode, raw_inode);
2723
2724 /*
2725 * Check if enough free space is available in the inode to shift the
2726 * entries ahead by new_extra_isize.
2727 */
2728
2729 base = IFIRST(header);
2730 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
2731 min_offs = end - base;
2732 total_ino = sizeof(struct ext4_xattr_ibody_header);
2733
2734 error = xattr_check_inode(inode, header, end);
2735 if (error)
2736 goto cleanup;
2737
2738 ifree = ext4_xattr_free_space(base, &min_offs, base, &total_ino);
2739 if (ifree >= isize_diff)
2740 goto shift;
2741
2742 /*
2743 * Enough free space isn't available in the inode, check if
2744 * EA block can hold new_extra_isize bytes.
2745 */
2746 if (EXT4_I(inode)->i_file_acl) {
2747 struct buffer_head *bh;
2748
2749 bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl);
2750 error = -EIO;
2751 if (!bh)
2752 goto cleanup;
2753 error = ext4_xattr_check_block(inode, bh);
2754 if (error) {
2755 brelse(bh);
2756 goto cleanup;
2757 }
2758 base = BHDR(bh);
2759 end = bh->b_data + bh->b_size;
2760 min_offs = end - base;
2761 bfree = ext4_xattr_free_space(BFIRST(bh), &min_offs, base,
2762 NULL);
2763 brelse(bh);
2764 if (bfree + ifree < isize_diff) {
2765 if (!tried_min_extra_isize && s_min_extra_isize) {
2766 tried_min_extra_isize++;
2767 new_extra_isize = s_min_extra_isize;
2768 goto retry;
2769 }
2770 error = -ENOSPC;
2771 goto cleanup;
2772 }
2773 } else {
2774 bfree = inode->i_sb->s_blocksize;
2775 }
2776
2777 error = ext4_xattr_make_inode_space(handle, inode, raw_inode,
2778 isize_diff, ifree, bfree,
2779 &total_ino);
2780 if (error) {
2781 if (error == -ENOSPC && !tried_min_extra_isize &&
2782 s_min_extra_isize) {
2783 tried_min_extra_isize++;
2784 new_extra_isize = s_min_extra_isize;
2785 goto retry;
2786 }
2787 goto cleanup;
2788 }
2789 shift:
2790 /* Adjust the offsets and shift the remaining entries ahead */
2791 ext4_xattr_shift_entries(IFIRST(header), EXT4_I(inode)->i_extra_isize
2792 - new_extra_isize, (void *)raw_inode +
2793 EXT4_GOOD_OLD_INODE_SIZE + new_extra_isize,
2794 (void *)header, total_ino);
2795 EXT4_I(inode)->i_extra_isize = new_extra_isize;
2796
2797 cleanup:
2798 if (error && (mnt_count != le16_to_cpu(sbi->s_es->s_mnt_count))) {
2799 ext4_warning(inode->i_sb, "Unable to expand inode %lu. Delete some EAs or run e2fsck.",
2800 inode->i_ino);
2801 mnt_count = le16_to_cpu(sbi->s_es->s_mnt_count);
2802 }
2803 return error;
2804 }
2805
2806 #define EIA_INCR 16 /* must be 2^n */
2807 #define EIA_MASK (EIA_INCR - 1)
2808
2809 /* Add the large xattr @inode into @ea_inode_array for deferred iput().
2810 * If @ea_inode_array is new or full it will be grown and the old
2811 * contents copied over.
2812 */
2813 static int
2814 ext4_expand_inode_array(struct ext4_xattr_inode_array **ea_inode_array,
2815 struct inode *inode)
2816 {
2817 if (*ea_inode_array == NULL) {
2818 /*
2819 * Start with 15 inodes, so it fits into a power-of-two size.
2820 * If *ea_inode_array is NULL, this is essentially offsetof()
2821 */
2822 (*ea_inode_array) =
2823 kmalloc(offsetof(struct ext4_xattr_inode_array,
2824 inodes[EIA_MASK]),
2825 GFP_NOFS);
2826 if (*ea_inode_array == NULL)
2827 return -ENOMEM;
2828 (*ea_inode_array)->count = 0;
2829 } else if (((*ea_inode_array)->count & EIA_MASK) == EIA_MASK) {
2830 /* expand the array once all 15 + n * 16 slots are full */
2831 struct ext4_xattr_inode_array *new_array = NULL;
2832 int count = (*ea_inode_array)->count;
2833
2834 /* if new_array is NULL, this is essentially offsetof() */
2835 new_array = kmalloc(
2836 offsetof(struct ext4_xattr_inode_array,
2837 inodes[count + EIA_INCR]),
2838 GFP_NOFS);
2839 if (new_array == NULL)
2840 return -ENOMEM;
2841 memcpy(new_array, *ea_inode_array,
2842 offsetof(struct ext4_xattr_inode_array, inodes[count]));
2843 kfree(*ea_inode_array);
2844 *ea_inode_array = new_array;
2845 }
2846 (*ea_inode_array)->inodes[(*ea_inode_array)->count++] = inode;
2847 return 0;
2848 }
2849
2850 /*
2851 * ext4_xattr_delete_inode()
2852 *
2853 * Free extended attribute resources associated with this inode. Traverse
2854 * all entries and decrement reference on any xattr inodes associated with this
2855 * inode. This is called immediately before an inode is freed. We have exclusive
2856 * access to the inode. If an orphan inode is deleted it will also release its
2857 * references on xattr block and xattr inodes.
2858 */
2859 int ext4_xattr_delete_inode(handle_t *handle, struct inode *inode,
2860 struct ext4_xattr_inode_array **ea_inode_array,
2861 int extra_credits)
2862 {
2863 struct buffer_head *bh = NULL;
2864 struct ext4_xattr_ibody_header *header;
2865 struct ext4_iloc iloc = { .bh = NULL };
2866 struct ext4_xattr_entry *entry;
2867 struct inode *ea_inode;
2868 int error;
2869
2870 error = ext4_xattr_ensure_credits(handle, inode, extra_credits,
2871 NULL /* bh */,
2872 false /* dirty */,
2873 false /* block_csum */);
2874 if (error) {
2875 EXT4_ERROR_INODE(inode, "ensure credits (error %d)", error);
2876 goto cleanup;
2877 }
2878
2879 if (ext4_has_feature_ea_inode(inode->i_sb) &&
2880 ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
2881
2882 error = ext4_get_inode_loc(inode, &iloc);
2883 if (error) {
2884 EXT4_ERROR_INODE(inode, "inode loc (error %d)", error);
2885 goto cleanup;
2886 }
2887
2888 error = ext4_journal_get_write_access(handle, iloc.bh);
2889 if (error) {
2890 EXT4_ERROR_INODE(inode, "write access (error %d)",
2891 error);
2892 goto cleanup;
2893 }
2894
2895 header = IHDR(inode, ext4_raw_inode(&iloc));
2896 if (header->h_magic == cpu_to_le32(EXT4_XATTR_MAGIC))
2897 ext4_xattr_inode_dec_ref_all(handle, inode, iloc.bh,
2898 IFIRST(header),
2899 false /* block_csum */,
2900 ea_inode_array,
2901 extra_credits,
2902 false /* skip_quota */);
2903 }
2904
2905 if (EXT4_I(inode)->i_file_acl) {
2906 bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl);
2907 if (!bh) {
2908 EXT4_ERROR_INODE(inode, "block %llu read error",
2909 EXT4_I(inode)->i_file_acl);
2910 error = -EIO;
2911 goto cleanup;
2912 }
2913 error = ext4_xattr_check_block(inode, bh);
2914 if (error)
2915 goto cleanup;
2916
2917 if (ext4_has_feature_ea_inode(inode->i_sb)) {
2918 for (entry = BFIRST(bh); !IS_LAST_ENTRY(entry);
2919 entry = EXT4_XATTR_NEXT(entry)) {
2920 if (!entry->e_value_inum)
2921 continue;
2922 error = ext4_xattr_inode_iget(inode,
2923 le32_to_cpu(entry->e_value_inum),
2924 le32_to_cpu(entry->e_hash),
2925 &ea_inode);
2926 if (error)
2927 continue;
2928 ext4_xattr_inode_free_quota(inode, ea_inode,
2929 le32_to_cpu(entry->e_value_size));
2930 iput(ea_inode);
2931 }
2932
2933 }
2934
2935 ext4_xattr_release_block(handle, inode, bh, ea_inode_array,
2936 extra_credits);
2937 /*
2938 * Update i_file_acl value in the same transaction that releases
2939 * block.
2940 */
2941 EXT4_I(inode)->i_file_acl = 0;
2942 error = ext4_mark_inode_dirty(handle, inode);
2943 if (error) {
2944 EXT4_ERROR_INODE(inode, "mark inode dirty (error %d)",
2945 error);
2946 goto cleanup;
2947 }
2948 }
2949 error = 0;
2950 cleanup:
2951 brelse(iloc.bh);
2952 brelse(bh);
2953 return error;
2954 }
2955
2956 void ext4_xattr_inode_array_free(struct ext4_xattr_inode_array *ea_inode_array)
2957 {
2958 int idx;
2959
2960 if (ea_inode_array == NULL)
2961 return;
2962
2963 for (idx = 0; idx < ea_inode_array->count; ++idx)
2964 iput(ea_inode_array->inodes[idx]);
2965 kfree(ea_inode_array);
2966 }
2967
2968 /*
2969 * ext4_xattr_block_cache_insert()
2970 *
2971 * Create a new entry in the extended attribute block cache, and insert
2972 * it unless such an entry is already in the cache.
2973 *
2974 * Returns 0, or a negative error number on failure.
2975 */
2976 static void
2977 ext4_xattr_block_cache_insert(struct mb_cache *ea_block_cache,
2978 struct buffer_head *bh)
2979 {
2980 struct ext4_xattr_header *header = BHDR(bh);
2981 __u32 hash = le32_to_cpu(header->h_hash);
2982 int reusable = le32_to_cpu(header->h_refcount) <
2983 EXT4_XATTR_REFCOUNT_MAX;
2984 int error;
2985
2986 if (!ea_block_cache)
2987 return;
2988 error = mb_cache_entry_create(ea_block_cache, GFP_NOFS, hash,
2989 bh->b_blocknr, reusable);
2990 if (error) {
2991 if (error == -EBUSY)
2992 ea_bdebug(bh, "already in cache");
2993 } else
2994 ea_bdebug(bh, "inserting [%x]", (int)hash);
2995 }
2996
2997 /*
2998 * ext4_xattr_cmp()
2999 *
3000 * Compare two extended attribute blocks for equality.
3001 *
3002 * Returns 0 if the blocks are equal, 1 if they differ, and
3003 * a negative error number on errors.
3004 */
3005 static int
3006 ext4_xattr_cmp(struct ext4_xattr_header *header1,
3007 struct ext4_xattr_header *header2)
3008 {
3009 struct ext4_xattr_entry *entry1, *entry2;
3010
3011 entry1 = ENTRY(header1+1);
3012 entry2 = ENTRY(header2+1);
3013 while (!IS_LAST_ENTRY(entry1)) {
3014 if (IS_LAST_ENTRY(entry2))
3015 return 1;
3016 if (entry1->e_hash != entry2->e_hash ||
3017 entry1->e_name_index != entry2->e_name_index ||
3018 entry1->e_name_len != entry2->e_name_len ||
3019 entry1->e_value_size != entry2->e_value_size ||
3020 entry1->e_value_inum != entry2->e_value_inum ||
3021 memcmp(entry1->e_name, entry2->e_name, entry1->e_name_len))
3022 return 1;
3023 if (!entry1->e_value_inum &&
3024 memcmp((char *)header1 + le16_to_cpu(entry1->e_value_offs),
3025 (char *)header2 + le16_to_cpu(entry2->e_value_offs),
3026 le32_to_cpu(entry1->e_value_size)))
3027 return 1;
3028
3029 entry1 = EXT4_XATTR_NEXT(entry1);
3030 entry2 = EXT4_XATTR_NEXT(entry2);
3031 }
3032 if (!IS_LAST_ENTRY(entry2))
3033 return 1;
3034 return 0;
3035 }
3036
3037 /*
3038 * ext4_xattr_block_cache_find()
3039 *
3040 * Find an identical extended attribute block.
3041 *
3042 * Returns a pointer to the block found, or NULL if such a block was
3043 * not found or an error occurred.
3044 */
3045 static struct buffer_head *
3046 ext4_xattr_block_cache_find(struct inode *inode,
3047 struct ext4_xattr_header *header,
3048 struct mb_cache_entry **pce)
3049 {
3050 __u32 hash = le32_to_cpu(header->h_hash);
3051 struct mb_cache_entry *ce;
3052 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
3053
3054 if (!ea_block_cache)
3055 return NULL;
3056 if (!header->h_hash)
3057 return NULL; /* never share */
3058 ea_idebug(inode, "looking for cached blocks [%x]", (int)hash);
3059 ce = mb_cache_entry_find_first(ea_block_cache, hash);
3060 while (ce) {
3061 struct buffer_head *bh;
3062
3063 bh = sb_bread(inode->i_sb, ce->e_value);
3064 if (!bh) {
3065 EXT4_ERROR_INODE(inode, "block %lu read error",
3066 (unsigned long)ce->e_value);
3067 } else if (ext4_xattr_cmp(header, BHDR(bh)) == 0) {
3068 *pce = ce;
3069 return bh;
3070 }
3071 brelse(bh);
3072 ce = mb_cache_entry_find_next(ea_block_cache, ce);
3073 }
3074 return NULL;
3075 }
3076
3077 #define NAME_HASH_SHIFT 5
3078 #define VALUE_HASH_SHIFT 16
3079
3080 /*
3081 * ext4_xattr_hash_entry()
3082 *
3083 * Compute the hash of an extended attribute.
3084 */
3085 static __le32 ext4_xattr_hash_entry(char *name, size_t name_len, __le32 *value,
3086 size_t value_count)
3087 {
3088 __u32 hash = 0;
3089
3090 while (name_len--) {
3091 hash = (hash << NAME_HASH_SHIFT) ^
3092 (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^
3093 *name++;
3094 }
3095 while (value_count--) {
3096 hash = (hash << VALUE_HASH_SHIFT) ^
3097 (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^
3098 le32_to_cpu(*value++);
3099 }
3100 return cpu_to_le32(hash);
3101 }
3102
3103 #undef NAME_HASH_SHIFT
3104 #undef VALUE_HASH_SHIFT
3105
3106 #define BLOCK_HASH_SHIFT 16
3107
3108 /*
3109 * ext4_xattr_rehash()
3110 *
3111 * Re-compute the extended attribute hash value after an entry has changed.
3112 */
3113 static void ext4_xattr_rehash(struct ext4_xattr_header *header)
3114 {
3115 struct ext4_xattr_entry *here;
3116 __u32 hash = 0;
3117
3118 here = ENTRY(header+1);
3119 while (!IS_LAST_ENTRY(here)) {
3120 if (!here->e_hash) {
3121 /* Block is not shared if an entry's hash value == 0 */
3122 hash = 0;
3123 break;
3124 }
3125 hash = (hash << BLOCK_HASH_SHIFT) ^
3126 (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^
3127 le32_to_cpu(here->e_hash);
3128 here = EXT4_XATTR_NEXT(here);
3129 }
3130 header->h_hash = cpu_to_le32(hash);
3131 }
3132
3133 #undef BLOCK_HASH_SHIFT
3134
3135 #define HASH_BUCKET_BITS 10
3136
3137 struct mb_cache *
3138 ext4_xattr_create_cache(void)
3139 {
3140 return mb_cache_create(HASH_BUCKET_BITS);
3141 }
3142
3143 void ext4_xattr_destroy_cache(struct mb_cache *cache)
3144 {
3145 if (cache)
3146 mb_cache_destroy(cache);
3147 }
3148
Linux with added FPC-III support