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perf tools: Don't clone maps from parent when synthesizing forks
[linux/fpc-iii.git] / fs / ext4 / xattr.c
blobf36fc5d5b257438666641028b8660c0ce3462e91
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 iloc.bh = NULL;
1036 goto out;
1037 }
1038
1039 ref_count = ext4_xattr_inode_get_ref(ea_inode);
1040 ref_count += ref_change;
1041 ext4_xattr_inode_set_ref(ea_inode, ref_count);
1042
1043 if (ref_change > 0) {
1044 WARN_ONCE(ref_count <= 0, "EA inode %lu ref_count=%lld",
1045 ea_inode->i_ino, ref_count);
1046
1047 if (ref_count == 1) {
1048 WARN_ONCE(ea_inode->i_nlink, "EA inode %lu i_nlink=%u",
1049 ea_inode->i_ino, ea_inode->i_nlink);
1050
1051 set_nlink(ea_inode, 1);
1052 ext4_orphan_del(handle, ea_inode);
1053
1054 if (ea_inode_cache) {
1055 hash = ext4_xattr_inode_get_hash(ea_inode);
1056 mb_cache_entry_create(ea_inode_cache,
1057 GFP_NOFS, hash,
1058 ea_inode->i_ino,
1059 true /* reusable */);
1060 }
1061 }
1062 } else {
1063 WARN_ONCE(ref_count < 0, "EA inode %lu ref_count=%lld",
1064 ea_inode->i_ino, ref_count);
1065
1066 if (ref_count == 0) {
1067 WARN_ONCE(ea_inode->i_nlink != 1,
1068 "EA inode %lu i_nlink=%u",
1069 ea_inode->i_ino, ea_inode->i_nlink);
1070
1071 clear_nlink(ea_inode);
1072 ext4_orphan_add(handle, ea_inode);
1073
1074 if (ea_inode_cache) {
1075 hash = ext4_xattr_inode_get_hash(ea_inode);
1076 mb_cache_entry_delete(ea_inode_cache, hash,
1077 ea_inode->i_ino);
1078 }
1079 }
1080 }
1081
1082 ret = ext4_mark_iloc_dirty(handle, ea_inode, &iloc);
1083 iloc.bh = NULL;
1084 if (ret)
1085 ext4_warning_inode(ea_inode,
1086 "ext4_mark_iloc_dirty() failed ret=%d", ret);
1087 out:
1088 brelse(iloc.bh);
1089 inode_unlock(ea_inode);
1090 return ret;
1091 }
1092
1093 static int ext4_xattr_inode_inc_ref(handle_t *handle, struct inode *ea_inode)
1094 {
1095 return ext4_xattr_inode_update_ref(handle, ea_inode, 1);
1096 }
1097
1098 static int ext4_xattr_inode_dec_ref(handle_t *handle, struct inode *ea_inode)
1099 {
1100 return ext4_xattr_inode_update_ref(handle, ea_inode, -1);
1101 }
1102
1103 static int ext4_xattr_inode_inc_ref_all(handle_t *handle, struct inode *parent,
1104 struct ext4_xattr_entry *first)
1105 {
1106 struct inode *ea_inode;
1107 struct ext4_xattr_entry *entry;
1108 struct ext4_xattr_entry *failed_entry;
1109 unsigned int ea_ino;
1110 int err, saved_err;
1111
1112 for (entry = first; !IS_LAST_ENTRY(entry);
1113 entry = EXT4_XATTR_NEXT(entry)) {
1114 if (!entry->e_value_inum)
1115 continue;
1116 ea_ino = le32_to_cpu(entry->e_value_inum);
1117 err = ext4_xattr_inode_iget(parent, ea_ino,
1118 le32_to_cpu(entry->e_hash),
1119 &ea_inode);
1120 if (err)
1121 goto cleanup;
1122 err = ext4_xattr_inode_inc_ref(handle, ea_inode);
1123 if (err) {
1124 ext4_warning_inode(ea_inode, "inc ref error %d", err);
1125 iput(ea_inode);
1126 goto cleanup;
1127 }
1128 iput(ea_inode);
1129 }
1130 return 0;
1131
1132 cleanup:
1133 saved_err = err;
1134 failed_entry = entry;
1135
1136 for (entry = first; entry != failed_entry;
1137 entry = EXT4_XATTR_NEXT(entry)) {
1138 if (!entry->e_value_inum)
1139 continue;
1140 ea_ino = le32_to_cpu(entry->e_value_inum);
1141 err = ext4_xattr_inode_iget(parent, ea_ino,
1142 le32_to_cpu(entry->e_hash),
1143 &ea_inode);
1144 if (err) {
1145 ext4_warning(parent->i_sb,
1146 "cleanup ea_ino %u iget error %d", ea_ino,
1147 err);
1148 continue;
1149 }
1150 err = ext4_xattr_inode_dec_ref(handle, ea_inode);
1151 if (err)
1152 ext4_warning_inode(ea_inode, "cleanup dec ref error %d",
1153 err);
1154 iput(ea_inode);
1155 }
1156 return saved_err;
1157 }
1158
1159 static void
1160 ext4_xattr_inode_dec_ref_all(handle_t *handle, struct inode *parent,
1161 struct buffer_head *bh,
1162 struct ext4_xattr_entry *first, bool block_csum,
1163 struct ext4_xattr_inode_array **ea_inode_array,
1164 int extra_credits, bool skip_quota)
1165 {
1166 struct inode *ea_inode;
1167 struct ext4_xattr_entry *entry;
1168 bool dirty = false;
1169 unsigned int ea_ino;
1170 int err;
1171 int credits;
1172
1173 /* One credit for dec ref on ea_inode, one for orphan list addition, */
1174 credits = 2 + extra_credits;
1175
1176 for (entry = first; !IS_LAST_ENTRY(entry);
1177 entry = EXT4_XATTR_NEXT(entry)) {
1178 if (!entry->e_value_inum)
1179 continue;
1180 ea_ino = le32_to_cpu(entry->e_value_inum);
1181 err = ext4_xattr_inode_iget(parent, ea_ino,
1182 le32_to_cpu(entry->e_hash),
1183 &ea_inode);
1184 if (err)
1185 continue;
1186
1187 err = ext4_expand_inode_array(ea_inode_array, ea_inode);
1188 if (err) {
1189 ext4_warning_inode(ea_inode,
1190 "Expand inode array err=%d", err);
1191 iput(ea_inode);
1192 continue;
1193 }
1194
1195 err = ext4_xattr_ensure_credits(handle, parent, credits, bh,
1196 dirty, block_csum);
1197 if (err) {
1198 ext4_warning_inode(ea_inode, "Ensure credits err=%d",
1199 err);
1200 continue;
1201 }
1202
1203 err = ext4_xattr_inode_dec_ref(handle, ea_inode);
1204 if (err) {
1205 ext4_warning_inode(ea_inode, "ea_inode dec ref err=%d",
1206 err);
1207 continue;
1208 }
1209
1210 if (!skip_quota)
1211 ext4_xattr_inode_free_quota(parent, ea_inode,
1212 le32_to_cpu(entry->e_value_size));
1213
1214 /*
1215 * Forget about ea_inode within the same transaction that
1216 * decrements the ref count. This avoids duplicate decrements in
1217 * case the rest of the work spills over to subsequent
1218 * transactions.
1219 */
1220 entry->e_value_inum = 0;
1221 entry->e_value_size = 0;
1222
1223 dirty = true;
1224 }
1225
1226 if (dirty) {
1227 /*
1228 * Note that we are deliberately skipping csum calculation for
1229 * the final update because we do not expect any journal
1230 * restarts until xattr block is freed.
1231 */
1232
1233 err = ext4_handle_dirty_metadata(handle, NULL, bh);
1234 if (err)
1235 ext4_warning_inode(parent,
1236 "handle dirty metadata err=%d", err);
1237 }
1238 }
1239
1240 /*
1241 * Release the xattr block BH: If the reference count is > 1, decrement it;
1242 * otherwise free the block.
1243 */
1244 static void
1245 ext4_xattr_release_block(handle_t *handle, struct inode *inode,
1246 struct buffer_head *bh,
1247 struct ext4_xattr_inode_array **ea_inode_array,
1248 int extra_credits)
1249 {
1250 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
1251 u32 hash, ref;
1252 int error = 0;
1253
1254 BUFFER_TRACE(bh, "get_write_access");
1255 error = ext4_journal_get_write_access(handle, bh);
1256 if (error)
1257 goto out;
1258
1259 lock_buffer(bh);
1260 hash = le32_to_cpu(BHDR(bh)->h_hash);
1261 ref = le32_to_cpu(BHDR(bh)->h_refcount);
1262 if (ref == 1) {
1263 ea_bdebug(bh, "refcount now=0; freeing");
1264 /*
1265 * This must happen under buffer lock for
1266 * ext4_xattr_block_set() to reliably detect freed block
1267 */
1268 if (ea_block_cache)
1269 mb_cache_entry_delete(ea_block_cache, hash,
1270 bh->b_blocknr);
1271 get_bh(bh);
1272 unlock_buffer(bh);
1273
1274 if (ext4_has_feature_ea_inode(inode->i_sb))
1275 ext4_xattr_inode_dec_ref_all(handle, inode, bh,
1276 BFIRST(bh),
1277 true /* block_csum */,
1278 ea_inode_array,
1279 extra_credits,
1280 true /* skip_quota */);
1281 ext4_free_blocks(handle, inode, bh, 0, 1,
1282 EXT4_FREE_BLOCKS_METADATA |
1283 EXT4_FREE_BLOCKS_FORGET);
1284 } else {
1285 ref--;
1286 BHDR(bh)->h_refcount = cpu_to_le32(ref);
1287 if (ref == EXT4_XATTR_REFCOUNT_MAX - 1) {
1288 struct mb_cache_entry *ce;
1289
1290 if (ea_block_cache) {
1291 ce = mb_cache_entry_get(ea_block_cache, hash,
1292 bh->b_blocknr);
1293 if (ce) {
1294 ce->e_reusable = 1;
1295 mb_cache_entry_put(ea_block_cache, ce);
1296 }
1297 }
1298 }
1299
1300 ext4_xattr_block_csum_set(inode, bh);
1301 /*
1302 * Beware of this ugliness: Releasing of xattr block references
1303 * from different inodes can race and so we have to protect
1304 * from a race where someone else frees the block (and releases
1305 * its journal_head) before we are done dirtying the buffer. In
1306 * nojournal mode this race is harmless and we actually cannot
1307 * call ext4_handle_dirty_metadata() with locked buffer as
1308 * that function can call sync_dirty_buffer() so for that case
1309 * we handle the dirtying after unlocking the buffer.
1310 */
1311 if (ext4_handle_valid(handle))
1312 error = ext4_handle_dirty_metadata(handle, inode, bh);
1313 unlock_buffer(bh);
1314 if (!ext4_handle_valid(handle))
1315 error = ext4_handle_dirty_metadata(handle, inode, bh);
1316 if (IS_SYNC(inode))
1317 ext4_handle_sync(handle);
1318 dquot_free_block(inode, EXT4_C2B(EXT4_SB(inode->i_sb), 1));
1319 ea_bdebug(bh, "refcount now=%d; releasing",
1320 le32_to_cpu(BHDR(bh)->h_refcount));
1321 }
1322 out:
1323 ext4_std_error(inode->i_sb, error);
1324 return;
1325 }
1326
1327 /*
1328 * Find the available free space for EAs. This also returns the total number of
1329 * bytes used by EA entries.
1330 */
1331 static size_t ext4_xattr_free_space(struct ext4_xattr_entry *last,
1332 size_t *min_offs, void *base, int *total)
1333 {
1334 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
1335 if (!last->e_value_inum && last->e_value_size) {
1336 size_t offs = le16_to_cpu(last->e_value_offs);
1337 if (offs < *min_offs)
1338 *min_offs = offs;
1339 }
1340 if (total)
1341 *total += EXT4_XATTR_LEN(last->e_name_len);
1342 }
1343 return (*min_offs - ((void *)last - base) - sizeof(__u32));
1344 }
1345
1346 /*
1347 * Write the value of the EA in an inode.
1348 */
1349 static int ext4_xattr_inode_write(handle_t *handle, struct inode *ea_inode,
1350 const void *buf, int bufsize)
1351 {
1352 struct buffer_head *bh = NULL;
1353 unsigned long block = 0;
1354 int blocksize = ea_inode->i_sb->s_blocksize;
1355 int max_blocks = (bufsize + blocksize - 1) >> ea_inode->i_blkbits;
1356 int csize, wsize = 0;
1357 int ret = 0;
1358 int retries = 0;
1359
1360 retry:
1361 while (ret >= 0 && ret < max_blocks) {
1362 struct ext4_map_blocks map;
1363 map.m_lblk = block += ret;
1364 map.m_len = max_blocks -= ret;
1365
1366 ret = ext4_map_blocks(handle, ea_inode, &map,
1367 EXT4_GET_BLOCKS_CREATE);
1368 if (ret <= 0) {
1369 ext4_mark_inode_dirty(handle, ea_inode);
1370 if (ret == -ENOSPC &&
1371 ext4_should_retry_alloc(ea_inode->i_sb, &retries)) {
1372 ret = 0;
1373 goto retry;
1374 }
1375 break;
1376 }
1377 }
1378
1379 if (ret < 0)
1380 return ret;
1381
1382 block = 0;
1383 while (wsize < bufsize) {
1384 if (bh != NULL)
1385 brelse(bh);
1386 csize = (bufsize - wsize) > blocksize ? blocksize :
1387 bufsize - wsize;
1388 bh = ext4_getblk(handle, ea_inode, block, 0);
1389 if (IS_ERR(bh))
1390 return PTR_ERR(bh);
1391 ret = ext4_journal_get_write_access(handle, bh);
1392 if (ret)
1393 goto out;
1394
1395 memcpy(bh->b_data, buf, csize);
1396 set_buffer_uptodate(bh);
1397 ext4_handle_dirty_metadata(handle, ea_inode, bh);
1398
1399 buf += csize;
1400 wsize += csize;
1401 block += 1;
1402 }
1403
1404 inode_lock(ea_inode);
1405 i_size_write(ea_inode, wsize);
1406 ext4_update_i_disksize(ea_inode, wsize);
1407 inode_unlock(ea_inode);
1408
1409 ext4_mark_inode_dirty(handle, ea_inode);
1410
1411 out:
1412 brelse(bh);
1413
1414 return ret;
1415 }
1416
1417 /*
1418 * Create an inode to store the value of a large EA.
1419 */
1420 static struct inode *ext4_xattr_inode_create(handle_t *handle,
1421 struct inode *inode, u32 hash)
1422 {
1423 struct inode *ea_inode = NULL;
1424 uid_t owner[2] = { i_uid_read(inode), i_gid_read(inode) };
1425 int err;
1426
1427 /*
1428 * Let the next inode be the goal, so we try and allocate the EA inode
1429 * in the same group, or nearby one.
1430 */
1431 ea_inode = ext4_new_inode(handle, inode->i_sb->s_root->d_inode,
1432 S_IFREG | 0600, NULL, inode->i_ino + 1, owner,
1433 EXT4_EA_INODE_FL);
1434 if (!IS_ERR(ea_inode)) {
1435 ea_inode->i_op = &ext4_file_inode_operations;
1436 ea_inode->i_fop = &ext4_file_operations;
1437 ext4_set_aops(ea_inode);
1438 ext4_xattr_inode_set_class(ea_inode);
1439 unlock_new_inode(ea_inode);
1440 ext4_xattr_inode_set_ref(ea_inode, 1);
1441 ext4_xattr_inode_set_hash(ea_inode, hash);
1442 err = ext4_mark_inode_dirty(handle, ea_inode);
1443 if (!err)
1444 err = ext4_inode_attach_jinode(ea_inode);
1445 if (err) {
1446 iput(ea_inode);
1447 return ERR_PTR(err);
1448 }
1449
1450 /*
1451 * Xattr inodes are shared therefore quota charging is performed
1452 * at a higher level.
1453 */
1454 dquot_free_inode(ea_inode);
1455 dquot_drop(ea_inode);
1456 inode_lock(ea_inode);
1457 ea_inode->i_flags |= S_NOQUOTA;
1458 inode_unlock(ea_inode);
1459 }
1460
1461 return ea_inode;
1462 }
1463
1464 static struct inode *
1465 ext4_xattr_inode_cache_find(struct inode *inode, const void *value,
1466 size_t value_len, u32 hash)
1467 {
1468 struct inode *ea_inode;
1469 struct mb_cache_entry *ce;
1470 struct mb_cache *ea_inode_cache = EA_INODE_CACHE(inode);
1471 void *ea_data;
1472
1473 if (!ea_inode_cache)
1474 return NULL;
1475
1476 ce = mb_cache_entry_find_first(ea_inode_cache, hash);
1477 if (!ce)
1478 return NULL;
1479
1480 ea_data = ext4_kvmalloc(value_len, GFP_NOFS);
1481 if (!ea_data) {
1482 mb_cache_entry_put(ea_inode_cache, ce);
1483 return NULL;
1484 }
1485
1486 while (ce) {
1487 ea_inode = ext4_iget(inode->i_sb, ce->e_value);
1488 if (!IS_ERR(ea_inode) &&
1489 !is_bad_inode(ea_inode) &&
1490 (EXT4_I(ea_inode)->i_flags & EXT4_EA_INODE_FL) &&
1491 i_size_read(ea_inode) == value_len &&
1492 !ext4_xattr_inode_read(ea_inode, ea_data, value_len) &&
1493 !ext4_xattr_inode_verify_hashes(ea_inode, NULL, ea_data,
1494 value_len) &&
1495 !memcmp(value, ea_data, value_len)) {
1496 mb_cache_entry_touch(ea_inode_cache, ce);
1497 mb_cache_entry_put(ea_inode_cache, ce);
1498 kvfree(ea_data);
1499 return ea_inode;
1500 }
1501
1502 if (!IS_ERR(ea_inode))
1503 iput(ea_inode);
1504 ce = mb_cache_entry_find_next(ea_inode_cache, ce);
1505 }
1506 kvfree(ea_data);
1507 return NULL;
1508 }
1509
1510 /*
1511 * Add value of the EA in an inode.
1512 */
1513 static int ext4_xattr_inode_lookup_create(handle_t *handle, struct inode *inode,
1514 const void *value, size_t value_len,
1515 struct inode **ret_inode)
1516 {
1517 struct inode *ea_inode;
1518 u32 hash;
1519 int err;
1520
1521 hash = ext4_xattr_inode_hash(EXT4_SB(inode->i_sb), value, value_len);
1522 ea_inode = ext4_xattr_inode_cache_find(inode, value, value_len, hash);
1523 if (ea_inode) {
1524 err = ext4_xattr_inode_inc_ref(handle, ea_inode);
1525 if (err) {
1526 iput(ea_inode);
1527 return err;
1528 }
1529
1530 *ret_inode = ea_inode;
1531 return 0;
1532 }
1533
1534 /* Create an inode for the EA value */
1535 ea_inode = ext4_xattr_inode_create(handle, inode, hash);
1536 if (IS_ERR(ea_inode))
1537 return PTR_ERR(ea_inode);
1538
1539 err = ext4_xattr_inode_write(handle, ea_inode, value, value_len);
1540 if (err) {
1541 ext4_xattr_inode_dec_ref(handle, ea_inode);
1542 iput(ea_inode);
1543 return err;
1544 }
1545
1546 if (EA_INODE_CACHE(inode))
1547 mb_cache_entry_create(EA_INODE_CACHE(inode), GFP_NOFS, hash,
1548 ea_inode->i_ino, true /* reusable */);
1549
1550 *ret_inode = ea_inode;
1551 return 0;
1552 }
1553
1554 /*
1555 * Reserve min(block_size/8, 1024) bytes for xattr entries/names if ea_inode
1556 * feature is enabled.
1557 */
1558 #define EXT4_XATTR_BLOCK_RESERVE(inode) min(i_blocksize(inode)/8, 1024U)
1559
1560 static int ext4_xattr_set_entry(struct ext4_xattr_info *i,
1561 struct ext4_xattr_search *s,
1562 handle_t *handle, struct inode *inode,
1563 bool is_block)
1564 {
1565 struct ext4_xattr_entry *last, *next;
1566 struct ext4_xattr_entry *here = s->here;
1567 size_t min_offs = s->end - s->base, name_len = strlen(i->name);
1568 int in_inode = i->in_inode;
1569 struct inode *old_ea_inode = NULL;
1570 struct inode *new_ea_inode = NULL;
1571 size_t old_size, new_size;
1572 int ret;
1573
1574 /* Space used by old and new values. */
1575 old_size = (!s->not_found && !here->e_value_inum) ?
1576 EXT4_XATTR_SIZE(le32_to_cpu(here->e_value_size)) : 0;
1577 new_size = (i->value && !in_inode) ? EXT4_XATTR_SIZE(i->value_len) : 0;
1578
1579 /*
1580 * Optimization for the simple case when old and new values have the
1581 * same padded sizes. Not applicable if external inodes are involved.
1582 */
1583 if (new_size && new_size == old_size) {
1584 size_t offs = le16_to_cpu(here->e_value_offs);
1585 void *val = s->base + offs;
1586
1587 here->e_value_size = cpu_to_le32(i->value_len);
1588 if (i->value == EXT4_ZERO_XATTR_VALUE) {
1589 memset(val, 0, new_size);
1590 } else {
1591 memcpy(val, i->value, i->value_len);
1592 /* Clear padding bytes. */
1593 memset(val + i->value_len, 0, new_size - i->value_len);
1594 }
1595 goto update_hash;
1596 }
1597
1598 /* Compute min_offs and last. */
1599 last = s->first;
1600 for (; !IS_LAST_ENTRY(last); last = next) {
1601 next = EXT4_XATTR_NEXT(last);
1602 if ((void *)next >= s->end) {
1603 EXT4_ERROR_INODE(inode, "corrupted xattr entries");
1604 ret = -EFSCORRUPTED;
1605 goto out;
1606 }
1607 if (!last->e_value_inum && last->e_value_size) {
1608 size_t offs = le16_to_cpu(last->e_value_offs);
1609 if (offs < min_offs)
1610 min_offs = offs;
1611 }
1612 }
1613
1614 /* Check whether we have enough space. */
1615 if (i->value) {
1616 size_t free;
1617
1618 free = min_offs - ((void *)last - s->base) - sizeof(__u32);
1619 if (!s->not_found)
1620 free += EXT4_XATTR_LEN(name_len) + old_size;
1621
1622 if (free < EXT4_XATTR_LEN(name_len) + new_size) {
1623 ret = -ENOSPC;
1624 goto out;
1625 }
1626
1627 /*
1628 * If storing the value in an external inode is an option,
1629 * reserve space for xattr entries/names in the external
1630 * attribute block so that a long value does not occupy the
1631 * whole space and prevent futher entries being added.
1632 */
1633 if (ext4_has_feature_ea_inode(inode->i_sb) &&
1634 new_size && is_block &&
1635 (min_offs + old_size - new_size) <
1636 EXT4_XATTR_BLOCK_RESERVE(inode)) {
1637 ret = -ENOSPC;
1638 goto out;
1639 }
1640 }
1641
1642 /*
1643 * Getting access to old and new ea inodes is subject to failures.
1644 * Finish that work before doing any modifications to the xattr data.
1645 */
1646 if (!s->not_found && here->e_value_inum) {
1647 ret = ext4_xattr_inode_iget(inode,
1648 le32_to_cpu(here->e_value_inum),
1649 le32_to_cpu(here->e_hash),
1650 &old_ea_inode);
1651 if (ret) {
1652 old_ea_inode = NULL;
1653 goto out;
1654 }
1655 }
1656 if (i->value && in_inode) {
1657 WARN_ON_ONCE(!i->value_len);
1658
1659 ret = ext4_xattr_inode_alloc_quota(inode, i->value_len);
1660 if (ret)
1661 goto out;
1662
1663 ret = ext4_xattr_inode_lookup_create(handle, inode, i->value,
1664 i->value_len,
1665 &new_ea_inode);
1666 if (ret) {
1667 new_ea_inode = NULL;
1668 ext4_xattr_inode_free_quota(inode, NULL, i->value_len);
1669 goto out;
1670 }
1671 }
1672
1673 if (old_ea_inode) {
1674 /* We are ready to release ref count on the old_ea_inode. */
1675 ret = ext4_xattr_inode_dec_ref(handle, old_ea_inode);
1676 if (ret) {
1677 /* Release newly required ref count on new_ea_inode. */
1678 if (new_ea_inode) {
1679 int err;
1680
1681 err = ext4_xattr_inode_dec_ref(handle,
1682 new_ea_inode);
1683 if (err)
1684 ext4_warning_inode(new_ea_inode,
1685 "dec ref new_ea_inode err=%d",
1686 err);
1687 ext4_xattr_inode_free_quota(inode, new_ea_inode,
1688 i->value_len);
1689 }
1690 goto out;
1691 }
1692
1693 ext4_xattr_inode_free_quota(inode, old_ea_inode,
1694 le32_to_cpu(here->e_value_size));
1695 }
1696
1697 /* No failures allowed past this point. */
1698
1699 if (!s->not_found && here->e_value_size && here->e_value_offs) {
1700 /* Remove the old value. */
1701 void *first_val = s->base + min_offs;
1702 size_t offs = le16_to_cpu(here->e_value_offs);
1703 void *val = s->base + offs;
1704
1705 memmove(first_val + old_size, first_val, val - first_val);
1706 memset(first_val, 0, old_size);
1707 min_offs += old_size;
1708
1709 /* Adjust all value offsets. */
1710 last = s->first;
1711 while (!IS_LAST_ENTRY(last)) {
1712 size_t o = le16_to_cpu(last->e_value_offs);
1713
1714 if (!last->e_value_inum &&
1715 last->e_value_size && o < offs)
1716 last->e_value_offs = cpu_to_le16(o + old_size);
1717 last = EXT4_XATTR_NEXT(last);
1718 }
1719 }
1720
1721 if (!i->value) {
1722 /* Remove old name. */
1723 size_t size = EXT4_XATTR_LEN(name_len);
1724
1725 last = ENTRY((void *)last - size);
1726 memmove(here, (void *)here + size,
1727 (void *)last - (void *)here + sizeof(__u32));
1728 memset(last, 0, size);
1729 } else if (s->not_found) {
1730 /* Insert new name. */
1731 size_t size = EXT4_XATTR_LEN(name_len);
1732 size_t rest = (void *)last - (void *)here + sizeof(__u32);
1733
1734 memmove((void *)here + size, here, rest);
1735 memset(here, 0, size);
1736 here->e_name_index = i->name_index;
1737 here->e_name_len = name_len;
1738 memcpy(here->e_name, i->name, name_len);
1739 } else {
1740 /* This is an update, reset value info. */
1741 here->e_value_inum = 0;
1742 here->e_value_offs = 0;
1743 here->e_value_size = 0;
1744 }
1745
1746 if (i->value) {
1747 /* Insert new value. */
1748 if (in_inode) {
1749 here->e_value_inum = cpu_to_le32(new_ea_inode->i_ino);
1750 } else if (i->value_len) {
1751 void *val = s->base + min_offs - new_size;
1752
1753 here->e_value_offs = cpu_to_le16(min_offs - new_size);
1754 if (i->value == EXT4_ZERO_XATTR_VALUE) {
1755 memset(val, 0, new_size);
1756 } else {
1757 memcpy(val, i->value, i->value_len);
1758 /* Clear padding bytes. */
1759 memset(val + i->value_len, 0,
1760 new_size - i->value_len);
1761 }
1762 }
1763 here->e_value_size = cpu_to_le32(i->value_len);
1764 }
1765
1766 update_hash:
1767 if (i->value) {
1768 __le32 hash = 0;
1769
1770 /* Entry hash calculation. */
1771 if (in_inode) {
1772 __le32 crc32c_hash;
1773
1774 /*
1775 * Feed crc32c hash instead of the raw value for entry
1776 * hash calculation. This is to avoid walking
1777 * potentially long value buffer again.
1778 */
1779 crc32c_hash = cpu_to_le32(
1780 ext4_xattr_inode_get_hash(new_ea_inode));
1781 hash = ext4_xattr_hash_entry(here->e_name,
1782 here->e_name_len,
1783 &crc32c_hash, 1);
1784 } else if (is_block) {
1785 __le32 *value = s->base + le16_to_cpu(
1786 here->e_value_offs);
1787
1788 hash = ext4_xattr_hash_entry(here->e_name,
1789 here->e_name_len, value,
1790 new_size >> 2);
1791 }
1792 here->e_hash = hash;
1793 }
1794
1795 if (is_block)
1796 ext4_xattr_rehash((struct ext4_xattr_header *)s->base);
1797
1798 ret = 0;
1799 out:
1800 iput(old_ea_inode);
1801 iput(new_ea_inode);
1802 return ret;
1803 }
1804
1805 struct ext4_xattr_block_find {
1806 struct ext4_xattr_search s;
1807 struct buffer_head *bh;
1808 };
1809
1810 static int
1811 ext4_xattr_block_find(struct inode *inode, struct ext4_xattr_info *i,
1812 struct ext4_xattr_block_find *bs)
1813 {
1814 struct super_block *sb = inode->i_sb;
1815 int error;
1816
1817 ea_idebug(inode, "name=%d.%s, value=%p, value_len=%ld",
1818 i->name_index, i->name, i->value, (long)i->value_len);
1819
1820 if (EXT4_I(inode)->i_file_acl) {
1821 /* The inode already has an extended attribute block. */
1822 bs->bh = sb_bread(sb, EXT4_I(inode)->i_file_acl);
1823 error = -EIO;
1824 if (!bs->bh)
1825 goto cleanup;
1826 ea_bdebug(bs->bh, "b_count=%d, refcount=%d",
1827 atomic_read(&(bs->bh->b_count)),
1828 le32_to_cpu(BHDR(bs->bh)->h_refcount));
1829 error = ext4_xattr_check_block(inode, bs->bh);
1830 if (error)
1831 goto cleanup;
1832 /* Find the named attribute. */
1833 bs->s.base = BHDR(bs->bh);
1834 bs->s.first = BFIRST(bs->bh);
1835 bs->s.end = bs->bh->b_data + bs->bh->b_size;
1836 bs->s.here = bs->s.first;
1837 error = xattr_find_entry(inode, &bs->s.here, bs->s.end,
1838 i->name_index, i->name, 1);
1839 if (error && error != -ENODATA)
1840 goto cleanup;
1841 bs->s.not_found = error;
1842 }
1843 error = 0;
1844
1845 cleanup:
1846 return error;
1847 }
1848
1849 static int
1850 ext4_xattr_block_set(handle_t *handle, struct inode *inode,
1851 struct ext4_xattr_info *i,
1852 struct ext4_xattr_block_find *bs)
1853 {
1854 struct super_block *sb = inode->i_sb;
1855 struct buffer_head *new_bh = NULL;
1856 struct ext4_xattr_search s_copy = bs->s;
1857 struct ext4_xattr_search *s = &s_copy;
1858 struct mb_cache_entry *ce = NULL;
1859 int error = 0;
1860 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
1861 struct inode *ea_inode = NULL, *tmp_inode;
1862 size_t old_ea_inode_quota = 0;
1863 unsigned int ea_ino;
1864
1865
1866 #define header(x) ((struct ext4_xattr_header *)(x))
1867
1868 if (s->base) {
1869 BUFFER_TRACE(bs->bh, "get_write_access");
1870 error = ext4_journal_get_write_access(handle, bs->bh);
1871 if (error)
1872 goto cleanup;
1873 lock_buffer(bs->bh);
1874
1875 if (header(s->base)->h_refcount == cpu_to_le32(1)) {
1876 __u32 hash = le32_to_cpu(BHDR(bs->bh)->h_hash);
1877
1878 /*
1879 * This must happen under buffer lock for
1880 * ext4_xattr_block_set() to reliably detect modified
1881 * block
1882 */
1883 if (ea_block_cache)
1884 mb_cache_entry_delete(ea_block_cache, hash,
1885 bs->bh->b_blocknr);
1886 ea_bdebug(bs->bh, "modifying in-place");
1887 error = ext4_xattr_set_entry(i, s, handle, inode,
1888 true /* is_block */);
1889 ext4_xattr_block_csum_set(inode, bs->bh);
1890 unlock_buffer(bs->bh);
1891 if (error == -EFSCORRUPTED)
1892 goto bad_block;
1893 if (!error)
1894 error = ext4_handle_dirty_metadata(handle,
1895 inode,
1896 bs->bh);
1897 if (error)
1898 goto cleanup;
1899 goto inserted;
1900 } else {
1901 int offset = (char *)s->here - bs->bh->b_data;
1902
1903 unlock_buffer(bs->bh);
1904 ea_bdebug(bs->bh, "cloning");
1905 s->base = kmalloc(bs->bh->b_size, GFP_NOFS);
1906 error = -ENOMEM;
1907 if (s->base == NULL)
1908 goto cleanup;
1909 memcpy(s->base, BHDR(bs->bh), bs->bh->b_size);
1910 s->first = ENTRY(header(s->base)+1);
1911 header(s->base)->h_refcount = cpu_to_le32(1);
1912 s->here = ENTRY(s->base + offset);
1913 s->end = s->base + bs->bh->b_size;
1914
1915 /*
1916 * If existing entry points to an xattr inode, we need
1917 * to prevent ext4_xattr_set_entry() from decrementing
1918 * ref count on it because the reference belongs to the
1919 * original block. In this case, make the entry look
1920 * like it has an empty value.
1921 */
1922 if (!s->not_found && s->here->e_value_inum) {
1923 ea_ino = le32_to_cpu(s->here->e_value_inum);
1924 error = ext4_xattr_inode_iget(inode, ea_ino,
1925 le32_to_cpu(s->here->e_hash),
1926 &tmp_inode);
1927 if (error)
1928 goto cleanup;
1929
1930 if (!ext4_test_inode_state(tmp_inode,
1931 EXT4_STATE_LUSTRE_EA_INODE)) {
1932 /*
1933 * Defer quota free call for previous
1934 * inode until success is guaranteed.
1935 */
1936 old_ea_inode_quota = le32_to_cpu(
1937 s->here->e_value_size);
1938 }
1939 iput(tmp_inode);
1940
1941 s->here->e_value_inum = 0;
1942 s->here->e_value_size = 0;
1943 }
1944 }
1945 } else {
1946 /* Allocate a buffer where we construct the new block. */
1947 s->base = kzalloc(sb->s_blocksize, GFP_NOFS);
1948 /* assert(header == s->base) */
1949 error = -ENOMEM;
1950 if (s->base == NULL)
1951 goto cleanup;
1952 header(s->base)->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
1953 header(s->base)->h_blocks = cpu_to_le32(1);
1954 header(s->base)->h_refcount = cpu_to_le32(1);
1955 s->first = ENTRY(header(s->base)+1);
1956 s->here = ENTRY(header(s->base)+1);
1957 s->end = s->base + sb->s_blocksize;
1958 }
1959
1960 error = ext4_xattr_set_entry(i, s, handle, inode, true /* is_block */);
1961 if (error == -EFSCORRUPTED)
1962 goto bad_block;
1963 if (error)
1964 goto cleanup;
1965
1966 if (i->value && s->here->e_value_inum) {
1967 /*
1968 * A ref count on ea_inode has been taken as part of the call to
1969 * ext4_xattr_set_entry() above. We would like to drop this
1970 * extra ref but we have to wait until the xattr block is
1971 * initialized and has its own ref count on the ea_inode.
1972 */
1973 ea_ino = le32_to_cpu(s->here->e_value_inum);
1974 error = ext4_xattr_inode_iget(inode, ea_ino,
1975 le32_to_cpu(s->here->e_hash),
1976 &ea_inode);
1977 if (error) {
1978 ea_inode = NULL;
1979 goto cleanup;
1980 }
1981 }
1982
1983 inserted:
1984 if (!IS_LAST_ENTRY(s->first)) {
1985 new_bh = ext4_xattr_block_cache_find(inode, header(s->base),
1986 &ce);
1987 if (new_bh) {
1988 /* We found an identical block in the cache. */
1989 if (new_bh == bs->bh)
1990 ea_bdebug(new_bh, "keeping");
1991 else {
1992 u32 ref;
1993
1994 WARN_ON_ONCE(dquot_initialize_needed(inode));
1995
1996 /* The old block is released after updating
1997 the inode. */
1998 error = dquot_alloc_block(inode,
1999 EXT4_C2B(EXT4_SB(sb), 1));
2000 if (error)
2001 goto cleanup;
2002 BUFFER_TRACE(new_bh, "get_write_access");
2003 error = ext4_journal_get_write_access(handle,
2004 new_bh);
2005 if (error)
2006 goto cleanup_dquot;
2007 lock_buffer(new_bh);
2008 /*
2009 * We have to be careful about races with
2010 * freeing, rehashing or adding references to
2011 * xattr block. Once we hold buffer lock xattr
2012 * block's state is stable so we can check
2013 * whether the block got freed / rehashed or
2014 * not. Since we unhash mbcache entry under
2015 * buffer lock when freeing / rehashing xattr
2016 * block, checking whether entry is still
2017 * hashed is reliable. Same rules hold for
2018 * e_reusable handling.
2019 */
2020 if (hlist_bl_unhashed(&ce->e_hash_list) ||
2021 !ce->e_reusable) {
2022 /*
2023 * Undo everything and check mbcache
2024 * again.
2025 */
2026 unlock_buffer(new_bh);
2027 dquot_free_block(inode,
2028 EXT4_C2B(EXT4_SB(sb),
2029 1));
2030 brelse(new_bh);
2031 mb_cache_entry_put(ea_block_cache, ce);
2032 ce = NULL;
2033 new_bh = NULL;
2034 goto inserted;
2035 }
2036 ref = le32_to_cpu(BHDR(new_bh)->h_refcount) + 1;
2037 BHDR(new_bh)->h_refcount = cpu_to_le32(ref);
2038 if (ref >= EXT4_XATTR_REFCOUNT_MAX)
2039 ce->e_reusable = 0;
2040 ea_bdebug(new_bh, "reusing; refcount now=%d",
2041 ref);
2042 ext4_xattr_block_csum_set(inode, new_bh);
2043 unlock_buffer(new_bh);
2044 error = ext4_handle_dirty_metadata(handle,
2045 inode,
2046 new_bh);
2047 if (error)
2048 goto cleanup_dquot;
2049 }
2050 mb_cache_entry_touch(ea_block_cache, ce);
2051 mb_cache_entry_put(ea_block_cache, ce);
2052 ce = NULL;
2053 } else if (bs->bh && s->base == bs->bh->b_data) {
2054 /* We were modifying this block in-place. */
2055 ea_bdebug(bs->bh, "keeping this block");
2056 ext4_xattr_block_cache_insert(ea_block_cache, bs->bh);
2057 new_bh = bs->bh;
2058 get_bh(new_bh);
2059 } else {
2060 /* We need to allocate a new block */
2061 ext4_fsblk_t goal, block;
2062
2063 WARN_ON_ONCE(dquot_initialize_needed(inode));
2064
2065 goal = ext4_group_first_block_no(sb,
2066 EXT4_I(inode)->i_block_group);
2067
2068 /* non-extent files can't have physical blocks past 2^32 */
2069 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
2070 goal = goal & EXT4_MAX_BLOCK_FILE_PHYS;
2071
2072 block = ext4_new_meta_blocks(handle, inode, goal, 0,
2073 NULL, &error);
2074 if (error)
2075 goto cleanup;
2076
2077 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
2078 BUG_ON(block > EXT4_MAX_BLOCK_FILE_PHYS);
2079
2080 ea_idebug(inode, "creating block %llu",
2081 (unsigned long long)block);
2082
2083 new_bh = sb_getblk(sb, block);
2084 if (unlikely(!new_bh)) {
2085 error = -ENOMEM;
2086 getblk_failed:
2087 ext4_free_blocks(handle, inode, NULL, block, 1,
2088 EXT4_FREE_BLOCKS_METADATA);
2089 goto cleanup;
2090 }
2091 error = ext4_xattr_inode_inc_ref_all(handle, inode,
2092 ENTRY(header(s->base)+1));
2093 if (error)
2094 goto getblk_failed;
2095 if (ea_inode) {
2096 /* Drop the extra ref on ea_inode. */
2097 error = ext4_xattr_inode_dec_ref(handle,
2098 ea_inode);
2099 if (error)
2100 ext4_warning_inode(ea_inode,
2101 "dec ref error=%d",
2102 error);
2103 iput(ea_inode);
2104 ea_inode = NULL;
2105 }
2106
2107 lock_buffer(new_bh);
2108 error = ext4_journal_get_create_access(handle, new_bh);
2109 if (error) {
2110 unlock_buffer(new_bh);
2111 error = -EIO;
2112 goto getblk_failed;
2113 }
2114 memcpy(new_bh->b_data, s->base, new_bh->b_size);
2115 ext4_xattr_block_csum_set(inode, new_bh);
2116 set_buffer_uptodate(new_bh);
2117 unlock_buffer(new_bh);
2118 ext4_xattr_block_cache_insert(ea_block_cache, new_bh);
2119 error = ext4_handle_dirty_metadata(handle, inode,
2120 new_bh);
2121 if (error)
2122 goto cleanup;
2123 }
2124 }
2125
2126 if (old_ea_inode_quota)
2127 ext4_xattr_inode_free_quota(inode, NULL, old_ea_inode_quota);
2128
2129 /* Update the inode. */
2130 EXT4_I(inode)->i_file_acl = new_bh ? new_bh->b_blocknr : 0;
2131
2132 /* Drop the previous xattr block. */
2133 if (bs->bh && bs->bh != new_bh) {
2134 struct ext4_xattr_inode_array *ea_inode_array = NULL;
2135
2136 ext4_xattr_release_block(handle, inode, bs->bh,
2137 &ea_inode_array,
2138 0 /* extra_credits */);
2139 ext4_xattr_inode_array_free(ea_inode_array);
2140 }
2141 error = 0;
2142
2143 cleanup:
2144 if (ea_inode) {
2145 int error2;
2146
2147 error2 = ext4_xattr_inode_dec_ref(handle, ea_inode);
2148 if (error2)
2149 ext4_warning_inode(ea_inode, "dec ref error=%d",
2150 error2);
2151
2152 /* If there was an error, revert the quota charge. */
2153 if (error)
2154 ext4_xattr_inode_free_quota(inode, ea_inode,
2155 i_size_read(ea_inode));
2156 iput(ea_inode);
2157 }
2158 if (ce)
2159 mb_cache_entry_put(ea_block_cache, ce);
2160 brelse(new_bh);
2161 if (!(bs->bh && s->base == bs->bh->b_data))
2162 kfree(s->base);
2163
2164 return error;
2165
2166 cleanup_dquot:
2167 dquot_free_block(inode, EXT4_C2B(EXT4_SB(sb), 1));
2168 goto cleanup;
2169
2170 bad_block:
2171 EXT4_ERROR_INODE(inode, "bad block %llu",
2172 EXT4_I(inode)->i_file_acl);
2173 goto cleanup;
2174
2175 #undef header
2176 }
2177
2178 int ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i,
2179 struct ext4_xattr_ibody_find *is)
2180 {
2181 struct ext4_xattr_ibody_header *header;
2182 struct ext4_inode *raw_inode;
2183 int error;
2184
2185 if (EXT4_I(inode)->i_extra_isize == 0)
2186 return 0;
2187 raw_inode = ext4_raw_inode(&is->iloc);
2188 header = IHDR(inode, raw_inode);
2189 is->s.base = is->s.first = IFIRST(header);
2190 is->s.here = is->s.first;
2191 is->s.end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
2192 if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
2193 error = xattr_check_inode(inode, header, is->s.end);
2194 if (error)
2195 return error;
2196 /* Find the named attribute. */
2197 error = xattr_find_entry(inode, &is->s.here, is->s.end,
2198 i->name_index, i->name, 0);
2199 if (error && error != -ENODATA)
2200 return error;
2201 is->s.not_found = error;
2202 }
2203 return 0;
2204 }
2205
2206 int ext4_xattr_ibody_inline_set(handle_t *handle, struct inode *inode,
2207 struct ext4_xattr_info *i,
2208 struct ext4_xattr_ibody_find *is)
2209 {
2210 struct ext4_xattr_ibody_header *header;
2211 struct ext4_xattr_search *s = &is->s;
2212 int error;
2213
2214 if (EXT4_I(inode)->i_extra_isize == 0)
2215 return -ENOSPC;
2216 error = ext4_xattr_set_entry(i, s, handle, inode, false /* is_block */);
2217 if (error)
2218 return error;
2219 header = IHDR(inode, ext4_raw_inode(&is->iloc));
2220 if (!IS_LAST_ENTRY(s->first)) {
2221 header->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
2222 ext4_set_inode_state(inode, EXT4_STATE_XATTR);
2223 } else {
2224 header->h_magic = cpu_to_le32(0);
2225 ext4_clear_inode_state(inode, EXT4_STATE_XATTR);
2226 }
2227 return 0;
2228 }
2229
2230 static int ext4_xattr_ibody_set(handle_t *handle, struct inode *inode,
2231 struct ext4_xattr_info *i,
2232 struct ext4_xattr_ibody_find *is)
2233 {
2234 struct ext4_xattr_ibody_header *header;
2235 struct ext4_xattr_search *s = &is->s;
2236 int error;
2237
2238 if (EXT4_I(inode)->i_extra_isize == 0)
2239 return -ENOSPC;
2240 error = ext4_xattr_set_entry(i, s, handle, inode, false /* is_block */);
2241 if (error)
2242 return error;
2243 header = IHDR(inode, ext4_raw_inode(&is->iloc));
2244 if (!IS_LAST_ENTRY(s->first)) {
2245 header->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
2246 ext4_set_inode_state(inode, EXT4_STATE_XATTR);
2247 } else {
2248 header->h_magic = cpu_to_le32(0);
2249 ext4_clear_inode_state(inode, EXT4_STATE_XATTR);
2250 }
2251 return 0;
2252 }
2253
2254 static int ext4_xattr_value_same(struct ext4_xattr_search *s,
2255 struct ext4_xattr_info *i)
2256 {
2257 void *value;
2258
2259 /* When e_value_inum is set the value is stored externally. */
2260 if (s->here->e_value_inum)
2261 return 0;
2262 if (le32_to_cpu(s->here->e_value_size) != i->value_len)
2263 return 0;
2264 value = ((void *)s->base) + le16_to_cpu(s->here->e_value_offs);
2265 return !memcmp(value, i->value, i->value_len);
2266 }
2267
2268 static struct buffer_head *ext4_xattr_get_block(struct inode *inode)
2269 {
2270 struct buffer_head *bh;
2271 int error;
2272
2273 if (!EXT4_I(inode)->i_file_acl)
2274 return NULL;
2275 bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl);
2276 if (!bh)
2277 return ERR_PTR(-EIO);
2278 error = ext4_xattr_check_block(inode, bh);
2279 if (error)
2280 return ERR_PTR(error);
2281 return bh;
2282 }
2283
2284 /*
2285 * ext4_xattr_set_handle()
2286 *
2287 * Create, replace or remove an extended attribute for this inode. Value
2288 * is NULL to remove an existing extended attribute, and non-NULL to
2289 * either replace an existing extended attribute, or create a new extended
2290 * attribute. The flags XATTR_REPLACE and XATTR_CREATE
2291 * specify that an extended attribute must exist and must not exist
2292 * previous to the call, respectively.
2293 *
2294 * Returns 0, or a negative error number on failure.
2295 */
2296 int
2297 ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
2298 const char *name, const void *value, size_t value_len,
2299 int flags)
2300 {
2301 struct ext4_xattr_info i = {
2302 .name_index = name_index,
2303 .name = name,
2304 .value = value,
2305 .value_len = value_len,
2306 .in_inode = 0,
2307 };
2308 struct ext4_xattr_ibody_find is = {
2309 .s = { .not_found = -ENODATA, },
2310 };
2311 struct ext4_xattr_block_find bs = {
2312 .s = { .not_found = -ENODATA, },
2313 };
2314 int no_expand;
2315 int error;
2316
2317 if (!name)
2318 return -EINVAL;
2319 if (strlen(name) > 255)
2320 return -ERANGE;
2321
2322 ext4_write_lock_xattr(inode, &no_expand);
2323
2324 /* Check journal credits under write lock. */
2325 if (ext4_handle_valid(handle)) {
2326 struct buffer_head *bh;
2327 int credits;
2328
2329 bh = ext4_xattr_get_block(inode);
2330 if (IS_ERR(bh)) {
2331 error = PTR_ERR(bh);
2332 goto cleanup;
2333 }
2334
2335 credits = __ext4_xattr_set_credits(inode->i_sb, inode, bh,
2336 value_len,
2337 flags & XATTR_CREATE);
2338 brelse(bh);
2339
2340 if (!ext4_handle_has_enough_credits(handle, credits)) {
2341 error = -ENOSPC;
2342 goto cleanup;
2343 }
2344 }
2345
2346 error = ext4_reserve_inode_write(handle, inode, &is.iloc);
2347 if (error)
2348 goto cleanup;
2349
2350 if (ext4_test_inode_state(inode, EXT4_STATE_NEW)) {
2351 struct ext4_inode *raw_inode = ext4_raw_inode(&is.iloc);
2352 memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size);
2353 ext4_clear_inode_state(inode, EXT4_STATE_NEW);
2354 }
2355
2356 error = ext4_xattr_ibody_find(inode, &i, &is);
2357 if (error)
2358 goto cleanup;
2359 if (is.s.not_found)
2360 error = ext4_xattr_block_find(inode, &i, &bs);
2361 if (error)
2362 goto cleanup;
2363 if (is.s.not_found && bs.s.not_found) {
2364 error = -ENODATA;
2365 if (flags & XATTR_REPLACE)
2366 goto cleanup;
2367 error = 0;
2368 if (!value)
2369 goto cleanup;
2370 } else {
2371 error = -EEXIST;
2372 if (flags & XATTR_CREATE)
2373 goto cleanup;
2374 }
2375
2376 if (!value) {
2377 if (!is.s.not_found)
2378 error = ext4_xattr_ibody_set(handle, inode, &i, &is);
2379 else if (!bs.s.not_found)
2380 error = ext4_xattr_block_set(handle, inode, &i, &bs);
2381 } else {
2382 error = 0;
2383 /* Xattr value did not change? Save us some work and bail out */
2384 if (!is.s.not_found && ext4_xattr_value_same(&is.s, &i))
2385 goto cleanup;
2386 if (!bs.s.not_found && ext4_xattr_value_same(&bs.s, &i))
2387 goto cleanup;
2388
2389 if (ext4_has_feature_ea_inode(inode->i_sb) &&
2390 (EXT4_XATTR_SIZE(i.value_len) >
2391 EXT4_XATTR_MIN_LARGE_EA_SIZE(inode->i_sb->s_blocksize)))
2392 i.in_inode = 1;
2393 retry_inode:
2394 error = ext4_xattr_ibody_set(handle, inode, &i, &is);
2395 if (!error && !bs.s.not_found) {
2396 i.value = NULL;
2397 error = ext4_xattr_block_set(handle, inode, &i, &bs);
2398 } else if (error == -ENOSPC) {
2399 if (EXT4_I(inode)->i_file_acl && !bs.s.base) {
2400 error = ext4_xattr_block_find(inode, &i, &bs);
2401 if (error)
2402 goto cleanup;
2403 }
2404 error = ext4_xattr_block_set(handle, inode, &i, &bs);
2405 if (!error && !is.s.not_found) {
2406 i.value = NULL;
2407 error = ext4_xattr_ibody_set(handle, inode, &i,
2408 &is);
2409 } else if (error == -ENOSPC) {
2410 /*
2411 * Xattr does not fit in the block, store at
2412 * external inode if possible.
2413 */
2414 if (ext4_has_feature_ea_inode(inode->i_sb) &&
2415 !i.in_inode) {
2416 i.in_inode = 1;
2417 goto retry_inode;
2418 }
2419 }
2420 }
2421 }
2422 if (!error) {
2423 ext4_xattr_update_super_block(handle, inode->i_sb);
2424 inode->i_ctime = current_time(inode);
2425 if (!value)
2426 no_expand = 0;
2427 error = ext4_mark_iloc_dirty(handle, inode, &is.iloc);
2428 /*
2429 * The bh is consumed by ext4_mark_iloc_dirty, even with
2430 * error != 0.
2431 */
2432 is.iloc.bh = NULL;
2433 if (IS_SYNC(inode))
2434 ext4_handle_sync(handle);
2435 }
2436
2437 cleanup:
2438 brelse(is.iloc.bh);
2439 brelse(bs.bh);
2440 ext4_write_unlock_xattr(inode, &no_expand);
2441 return error;
2442 }
2443
2444 int ext4_xattr_set_credits(struct inode *inode, size_t value_len,
2445 bool is_create, int *credits)
2446 {
2447 struct buffer_head *bh;
2448 int err;
2449
2450 *credits = 0;
2451
2452 if (!EXT4_SB(inode->i_sb)->s_journal)
2453 return 0;
2454
2455 down_read(&EXT4_I(inode)->xattr_sem);
2456
2457 bh = ext4_xattr_get_block(inode);
2458 if (IS_ERR(bh)) {
2459 err = PTR_ERR(bh);
2460 } else {
2461 *credits = __ext4_xattr_set_credits(inode->i_sb, inode, bh,
2462 value_len, is_create);
2463 brelse(bh);
2464 err = 0;
2465 }
2466
2467 up_read(&EXT4_I(inode)->xattr_sem);
2468 return err;
2469 }
2470
2471 /*
2472 * ext4_xattr_set()
2473 *
2474 * Like ext4_xattr_set_handle, but start from an inode. This extended
2475 * attribute modification is a filesystem transaction by itself.
2476 *
2477 * Returns 0, or a negative error number on failure.
2478 */
2479 int
2480 ext4_xattr_set(struct inode *inode, int name_index, const char *name,
2481 const void *value, size_t value_len, int flags)
2482 {
2483 handle_t *handle;
2484 struct super_block *sb = inode->i_sb;
2485 int error, retries = 0;
2486 int credits;
2487
2488 error = dquot_initialize(inode);
2489 if (error)
2490 return error;
2491
2492 retry:
2493 error = ext4_xattr_set_credits(inode, value_len, flags & XATTR_CREATE,
2494 &credits);
2495 if (error)
2496 return error;
2497
2498 handle = ext4_journal_start(inode, EXT4_HT_XATTR, credits);
2499 if (IS_ERR(handle)) {
2500 error = PTR_ERR(handle);
2501 } else {
2502 int error2;
2503
2504 error = ext4_xattr_set_handle(handle, inode, name_index, name,
2505 value, value_len, flags);
2506 error2 = ext4_journal_stop(handle);
2507 if (error == -ENOSPC &&
2508 ext4_should_retry_alloc(sb, &retries))
2509 goto retry;
2510 if (error == 0)
2511 error = error2;
2512 }
2513
2514 return error;
2515 }
2516
2517 /*
2518 * Shift the EA entries in the inode to create space for the increased
2519 * i_extra_isize.
2520 */
2521 static void ext4_xattr_shift_entries(struct ext4_xattr_entry *entry,
2522 int value_offs_shift, void *to,
2523 void *from, size_t n)
2524 {
2525 struct ext4_xattr_entry *last = entry;
2526 int new_offs;
2527
2528 /* We always shift xattr headers further thus offsets get lower */
2529 BUG_ON(value_offs_shift > 0);
2530
2531 /* Adjust the value offsets of the entries */
2532 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
2533 if (!last->e_value_inum && last->e_value_size) {
2534 new_offs = le16_to_cpu(last->e_value_offs) +
2535 value_offs_shift;
2536 last->e_value_offs = cpu_to_le16(new_offs);
2537 }
2538 }
2539 /* Shift the entries by n bytes */
2540 memmove(to, from, n);
2541 }
2542
2543 /*
2544 * Move xattr pointed to by 'entry' from inode into external xattr block
2545 */
2546 static int ext4_xattr_move_to_block(handle_t *handle, struct inode *inode,
2547 struct ext4_inode *raw_inode,
2548 struct ext4_xattr_entry *entry)
2549 {
2550 struct ext4_xattr_ibody_find *is = NULL;
2551 struct ext4_xattr_block_find *bs = NULL;
2552 char *buffer = NULL, *b_entry_name = NULL;
2553 size_t value_size = le32_to_cpu(entry->e_value_size);
2554 struct ext4_xattr_info i = {
2555 .value = NULL,
2556 .value_len = 0,
2557 .name_index = entry->e_name_index,
2558 .in_inode = !!entry->e_value_inum,
2559 };
2560 struct ext4_xattr_ibody_header *header = IHDR(inode, raw_inode);
2561 int error;
2562
2563 is = kzalloc(sizeof(struct ext4_xattr_ibody_find), GFP_NOFS);
2564 bs = kzalloc(sizeof(struct ext4_xattr_block_find), GFP_NOFS);
2565 buffer = kmalloc(value_size, GFP_NOFS);
2566 b_entry_name = kmalloc(entry->e_name_len + 1, GFP_NOFS);
2567 if (!is || !bs || !buffer || !b_entry_name) {
2568 error = -ENOMEM;
2569 goto out;
2570 }
2571
2572 is->s.not_found = -ENODATA;
2573 bs->s.not_found = -ENODATA;
2574 is->iloc.bh = NULL;
2575 bs->bh = NULL;
2576
2577 /* Save the entry name and the entry value */
2578 if (entry->e_value_inum) {
2579 error = ext4_xattr_inode_get(inode, entry, buffer, value_size);
2580 if (error)
2581 goto out;
2582 } else {
2583 size_t value_offs = le16_to_cpu(entry->e_value_offs);
2584 memcpy(buffer, (void *)IFIRST(header) + value_offs, value_size);
2585 }
2586
2587 memcpy(b_entry_name, entry->e_name, entry->e_name_len);
2588 b_entry_name[entry->e_name_len] = '\0';
2589 i.name = b_entry_name;
2590
2591 error = ext4_get_inode_loc(inode, &is->iloc);
2592 if (error)
2593 goto out;
2594
2595 error = ext4_xattr_ibody_find(inode, &i, is);
2596 if (error)
2597 goto out;
2598
2599 /* Remove the chosen entry from the inode */
2600 error = ext4_xattr_ibody_set(handle, inode, &i, is);
2601 if (error)
2602 goto out;
2603
2604 i.value = buffer;
2605 i.value_len = value_size;
2606 error = ext4_xattr_block_find(inode, &i, bs);
2607 if (error)
2608 goto out;
2609
2610 /* Add entry which was removed from the inode into the block */
2611 error = ext4_xattr_block_set(handle, inode, &i, bs);
2612 if (error)
2613 goto out;
2614 error = 0;
2615 out:
2616 kfree(b_entry_name);
2617 kfree(buffer);
2618 if (is)
2619 brelse(is->iloc.bh);
2620 kfree(is);
2621 kfree(bs);
2622
2623 return error;
2624 }
2625
2626 static int ext4_xattr_make_inode_space(handle_t *handle, struct inode *inode,
2627 struct ext4_inode *raw_inode,
2628 int isize_diff, size_t ifree,
2629 size_t bfree, int *total_ino)
2630 {
2631 struct ext4_xattr_ibody_header *header = IHDR(inode, raw_inode);
2632 struct ext4_xattr_entry *small_entry;
2633 struct ext4_xattr_entry *entry;
2634 struct ext4_xattr_entry *last;
2635 unsigned int entry_size; /* EA entry size */
2636 unsigned int total_size; /* EA entry size + value size */
2637 unsigned int min_total_size;
2638 int error;
2639
2640 while (isize_diff > ifree) {
2641 entry = NULL;
2642 small_entry = NULL;
2643 min_total_size = ~0U;
2644 last = IFIRST(header);
2645 /* Find the entry best suited to be pushed into EA block */
2646 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
2647 /* never move system.data out of the inode */
2648 if ((last->e_name_len == 4) &&
2649 (last->e_name_index == EXT4_XATTR_INDEX_SYSTEM) &&
2650 !memcmp(last->e_name, "data", 4))
2651 continue;
2652 total_size = EXT4_XATTR_LEN(last->e_name_len);
2653 if (!last->e_value_inum)
2654 total_size += EXT4_XATTR_SIZE(
2655 le32_to_cpu(last->e_value_size));
2656 if (total_size <= bfree &&
2657 total_size < min_total_size) {
2658 if (total_size + ifree < isize_diff) {
2659 small_entry = last;
2660 } else {
2661 entry = last;
2662 min_total_size = total_size;
2663 }
2664 }
2665 }
2666
2667 if (entry == NULL) {
2668 if (small_entry == NULL)
2669 return -ENOSPC;
2670 entry = small_entry;
2671 }
2672
2673 entry_size = EXT4_XATTR_LEN(entry->e_name_len);
2674 total_size = entry_size;
2675 if (!entry->e_value_inum)
2676 total_size += EXT4_XATTR_SIZE(
2677 le32_to_cpu(entry->e_value_size));
2678 error = ext4_xattr_move_to_block(handle, inode, raw_inode,
2679 entry);
2680 if (error)
2681 return error;
2682
2683 *total_ino -= entry_size;
2684 ifree += total_size;
2685 bfree -= total_size;
2686 }
2687
2688 return 0;
2689 }
2690
2691 /*
2692 * Expand an inode by new_extra_isize bytes when EAs are present.
2693 * Returns 0 on success or negative error number on failure.
2694 */
2695 int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
2696 struct ext4_inode *raw_inode, handle_t *handle)
2697 {
2698 struct ext4_xattr_ibody_header *header;
2699 struct buffer_head *bh;
2700 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2701 static unsigned int mnt_count;
2702 size_t min_offs;
2703 size_t ifree, bfree;
2704 int total_ino;
2705 void *base, *end;
2706 int error = 0, tried_min_extra_isize = 0;
2707 int s_min_extra_isize = le16_to_cpu(sbi->s_es->s_min_extra_isize);
2708 int isize_diff; /* How much do we need to grow i_extra_isize */
2709
2710 retry:
2711 isize_diff = new_extra_isize - EXT4_I(inode)->i_extra_isize;
2712 if (EXT4_I(inode)->i_extra_isize >= new_extra_isize)
2713 return 0;
2714
2715 header = IHDR(inode, raw_inode);
2716
2717 /*
2718 * Check if enough free space is available in the inode to shift the
2719 * entries ahead by new_extra_isize.
2720 */
2721
2722 base = IFIRST(header);
2723 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
2724 min_offs = end - base;
2725 total_ino = sizeof(struct ext4_xattr_ibody_header);
2726
2727 error = xattr_check_inode(inode, header, end);
2728 if (error)
2729 goto cleanup;
2730
2731 ifree = ext4_xattr_free_space(base, &min_offs, base, &total_ino);
2732 if (ifree >= isize_diff)
2733 goto shift;
2734
2735 /*
2736 * Enough free space isn't available in the inode, check if
2737 * EA block can hold new_extra_isize bytes.
2738 */
2739 if (EXT4_I(inode)->i_file_acl) {
2740 bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl);
2741 error = -EIO;
2742 if (!bh)
2743 goto cleanup;
2744 error = ext4_xattr_check_block(inode, bh);
2745 if (error)
2746 goto cleanup;
2747 base = BHDR(bh);
2748 end = bh->b_data + bh->b_size;
2749 min_offs = end - base;
2750 bfree = ext4_xattr_free_space(BFIRST(bh), &min_offs, base,
2751 NULL);
2752 brelse(bh);
2753 if (bfree + ifree < isize_diff) {
2754 if (!tried_min_extra_isize && s_min_extra_isize) {
2755 tried_min_extra_isize++;
2756 new_extra_isize = s_min_extra_isize;
2757 goto retry;
2758 }
2759 error = -ENOSPC;
2760 goto cleanup;
2761 }
2762 } else {
2763 bfree = inode->i_sb->s_blocksize;
2764 }
2765
2766 error = ext4_xattr_make_inode_space(handle, inode, raw_inode,
2767 isize_diff, ifree, bfree,
2768 &total_ino);
2769 if (error) {
2770 if (error == -ENOSPC && !tried_min_extra_isize &&
2771 s_min_extra_isize) {
2772 tried_min_extra_isize++;
2773 new_extra_isize = s_min_extra_isize;
2774 goto retry;
2775 }
2776 goto cleanup;
2777 }
2778 shift:
2779 /* Adjust the offsets and shift the remaining entries ahead */
2780 ext4_xattr_shift_entries(IFIRST(header), EXT4_I(inode)->i_extra_isize
2781 - new_extra_isize, (void *)raw_inode +
2782 EXT4_GOOD_OLD_INODE_SIZE + new_extra_isize,
2783 (void *)header, total_ino);
2784 EXT4_I(inode)->i_extra_isize = new_extra_isize;
2785
2786 cleanup:
2787 if (error && (mnt_count != le16_to_cpu(sbi->s_es->s_mnt_count))) {
2788 ext4_warning(inode->i_sb, "Unable to expand inode %lu. Delete some EAs or run e2fsck.",
2789 inode->i_ino);
2790 mnt_count = le16_to_cpu(sbi->s_es->s_mnt_count);
2791 }
2792 return error;
2793 }
2794
2795 #define EIA_INCR 16 /* must be 2^n */
2796 #define EIA_MASK (EIA_INCR - 1)
2797
2798 /* Add the large xattr @inode into @ea_inode_array for deferred iput().
2799 * If @ea_inode_array is new or full it will be grown and the old
2800 * contents copied over.
2801 */
2802 static int
2803 ext4_expand_inode_array(struct ext4_xattr_inode_array **ea_inode_array,
2804 struct inode *inode)
2805 {
2806 if (*ea_inode_array == NULL) {
2807 /*
2808 * Start with 15 inodes, so it fits into a power-of-two size.
2809 * If *ea_inode_array is NULL, this is essentially offsetof()
2810 */
2811 (*ea_inode_array) =
2812 kmalloc(offsetof(struct ext4_xattr_inode_array,
2813 inodes[EIA_MASK]),
2814 GFP_NOFS);
2815 if (*ea_inode_array == NULL)
2816 return -ENOMEM;
2817 (*ea_inode_array)->count = 0;
2818 } else if (((*ea_inode_array)->count & EIA_MASK) == EIA_MASK) {
2819 /* expand the array once all 15 + n * 16 slots are full */
2820 struct ext4_xattr_inode_array *new_array = NULL;
2821 int count = (*ea_inode_array)->count;
2822
2823 /* if new_array is NULL, this is essentially offsetof() */
2824 new_array = kmalloc(
2825 offsetof(struct ext4_xattr_inode_array,
2826 inodes[count + EIA_INCR]),
2827 GFP_NOFS);
2828 if (new_array == NULL)
2829 return -ENOMEM;
2830 memcpy(new_array, *ea_inode_array,
2831 offsetof(struct ext4_xattr_inode_array, inodes[count]));
2832 kfree(*ea_inode_array);
2833 *ea_inode_array = new_array;
2834 }
2835 (*ea_inode_array)->inodes[(*ea_inode_array)->count++] = inode;
2836 return 0;
2837 }
2838
2839 /*
2840 * ext4_xattr_delete_inode()
2841 *
2842 * Free extended attribute resources associated with this inode. Traverse
2843 * all entries and decrement reference on any xattr inodes associated with this
2844 * inode. This is called immediately before an inode is freed. We have exclusive
2845 * access to the inode. If an orphan inode is deleted it will also release its
2846 * references on xattr block and xattr inodes.
2847 */
2848 int ext4_xattr_delete_inode(handle_t *handle, struct inode *inode,
2849 struct ext4_xattr_inode_array **ea_inode_array,
2850 int extra_credits)
2851 {
2852 struct buffer_head *bh = NULL;
2853 struct ext4_xattr_ibody_header *header;
2854 struct ext4_iloc iloc = { .bh = NULL };
2855 struct ext4_xattr_entry *entry;
2856 struct inode *ea_inode;
2857 int error;
2858
2859 error = ext4_xattr_ensure_credits(handle, inode, extra_credits,
2860 NULL /* bh */,
2861 false /* dirty */,
2862 false /* block_csum */);
2863 if (error) {
2864 EXT4_ERROR_INODE(inode, "ensure credits (error %d)", error);
2865 goto cleanup;
2866 }
2867
2868 if (ext4_has_feature_ea_inode(inode->i_sb) &&
2869 ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
2870
2871 error = ext4_get_inode_loc(inode, &iloc);
2872 if (error) {
2873 EXT4_ERROR_INODE(inode, "inode loc (error %d)", error);
2874 goto cleanup;
2875 }
2876
2877 error = ext4_journal_get_write_access(handle, iloc.bh);
2878 if (error) {
2879 EXT4_ERROR_INODE(inode, "write access (error %d)",
2880 error);
2881 goto cleanup;
2882 }
2883
2884 header = IHDR(inode, ext4_raw_inode(&iloc));
2885 if (header->h_magic == cpu_to_le32(EXT4_XATTR_MAGIC))
2886 ext4_xattr_inode_dec_ref_all(handle, inode, iloc.bh,
2887 IFIRST(header),
2888 false /* block_csum */,
2889 ea_inode_array,
2890 extra_credits,
2891 false /* skip_quota */);
2892 }
2893
2894 if (EXT4_I(inode)->i_file_acl) {
2895 bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl);
2896 if (!bh) {
2897 EXT4_ERROR_INODE(inode, "block %llu read error",
2898 EXT4_I(inode)->i_file_acl);
2899 error = -EIO;
2900 goto cleanup;
2901 }
2902 error = ext4_xattr_check_block(inode, bh);
2903 if (error)
2904 goto cleanup;
2905
2906 if (ext4_has_feature_ea_inode(inode->i_sb)) {
2907 for (entry = BFIRST(bh); !IS_LAST_ENTRY(entry);
2908 entry = EXT4_XATTR_NEXT(entry)) {
2909 if (!entry->e_value_inum)
2910 continue;
2911 error = ext4_xattr_inode_iget(inode,
2912 le32_to_cpu(entry->e_value_inum),
2913 le32_to_cpu(entry->e_hash),
2914 &ea_inode);
2915 if (error)
2916 continue;
2917 ext4_xattr_inode_free_quota(inode, ea_inode,
2918 le32_to_cpu(entry->e_value_size));
2919 iput(ea_inode);
2920 }
2921
2922 }
2923
2924 ext4_xattr_release_block(handle, inode, bh, ea_inode_array,
2925 extra_credits);
2926 /*
2927 * Update i_file_acl value in the same transaction that releases
2928 * block.
2929 */
2930 EXT4_I(inode)->i_file_acl = 0;
2931 error = ext4_mark_inode_dirty(handle, inode);
2932 if (error) {
2933 EXT4_ERROR_INODE(inode, "mark inode dirty (error %d)",
2934 error);
2935 goto cleanup;
2936 }
2937 }
2938 error = 0;
2939 cleanup:
2940 brelse(iloc.bh);
2941 brelse(bh);
2942 return error;
2943 }
2944
2945 void ext4_xattr_inode_array_free(struct ext4_xattr_inode_array *ea_inode_array)
2946 {
2947 int idx;
2948
2949 if (ea_inode_array == NULL)
2950 return;
2951
2952 for (idx = 0; idx < ea_inode_array->count; ++idx)
2953 iput(ea_inode_array->inodes[idx]);
2954 kfree(ea_inode_array);
2955 }
2956
2957 /*
2958 * ext4_xattr_block_cache_insert()
2959 *
2960 * Create a new entry in the extended attribute block cache, and insert
2961 * it unless such an entry is already in the cache.
2962 *
2963 * Returns 0, or a negative error number on failure.
2964 */
2965 static void
2966 ext4_xattr_block_cache_insert(struct mb_cache *ea_block_cache,
2967 struct buffer_head *bh)
2968 {
2969 struct ext4_xattr_header *header = BHDR(bh);
2970 __u32 hash = le32_to_cpu(header->h_hash);
2971 int reusable = le32_to_cpu(header->h_refcount) <
2972 EXT4_XATTR_REFCOUNT_MAX;
2973 int error;
2974
2975 if (!ea_block_cache)
2976 return;
2977 error = mb_cache_entry_create(ea_block_cache, GFP_NOFS, hash,
2978 bh->b_blocknr, reusable);
2979 if (error) {
2980 if (error == -EBUSY)
2981 ea_bdebug(bh, "already in cache");
2982 } else
2983 ea_bdebug(bh, "inserting [%x]", (int)hash);
2984 }
2985
2986 /*
2987 * ext4_xattr_cmp()
2988 *
2989 * Compare two extended attribute blocks for equality.
2990 *
2991 * Returns 0 if the blocks are equal, 1 if they differ, and
2992 * a negative error number on errors.
2993 */
2994 static int
2995 ext4_xattr_cmp(struct ext4_xattr_header *header1,
2996 struct ext4_xattr_header *header2)
2997 {
2998 struct ext4_xattr_entry *entry1, *entry2;
2999
3000 entry1 = ENTRY(header1+1);
3001 entry2 = ENTRY(header2+1);
3002 while (!IS_LAST_ENTRY(entry1)) {
3003 if (IS_LAST_ENTRY(entry2))
3004 return 1;
3005 if (entry1->e_hash != entry2->e_hash ||
3006 entry1->e_name_index != entry2->e_name_index ||
3007 entry1->e_name_len != entry2->e_name_len ||
3008 entry1->e_value_size != entry2->e_value_size ||
3009 entry1->e_value_inum != entry2->e_value_inum ||
3010 memcmp(entry1->e_name, entry2->e_name, entry1->e_name_len))
3011 return 1;
3012 if (!entry1->e_value_inum &&
3013 memcmp((char *)header1 + le16_to_cpu(entry1->e_value_offs),
3014 (char *)header2 + le16_to_cpu(entry2->e_value_offs),
3015 le32_to_cpu(entry1->e_value_size)))
3016 return 1;
3017
3018 entry1 = EXT4_XATTR_NEXT(entry1);
3019 entry2 = EXT4_XATTR_NEXT(entry2);
3020 }
3021 if (!IS_LAST_ENTRY(entry2))
3022 return 1;
3023 return 0;
3024 }
3025
3026 /*
3027 * ext4_xattr_block_cache_find()
3028 *
3029 * Find an identical extended attribute block.
3030 *
3031 * Returns a pointer to the block found, or NULL if such a block was
3032 * not found or an error occurred.
3033 */
3034 static struct buffer_head *
3035 ext4_xattr_block_cache_find(struct inode *inode,
3036 struct ext4_xattr_header *header,
3037 struct mb_cache_entry **pce)
3038 {
3039 __u32 hash = le32_to_cpu(header->h_hash);
3040 struct mb_cache_entry *ce;
3041 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
3042
3043 if (!ea_block_cache)
3044 return NULL;
3045 if (!header->h_hash)
3046 return NULL; /* never share */
3047 ea_idebug(inode, "looking for cached blocks [%x]", (int)hash);
3048 ce = mb_cache_entry_find_first(ea_block_cache, hash);
3049 while (ce) {
3050 struct buffer_head *bh;
3051
3052 bh = sb_bread(inode->i_sb, ce->e_value);
3053 if (!bh) {
3054 EXT4_ERROR_INODE(inode, "block %lu read error",
3055 (unsigned long)ce->e_value);
3056 } else if (ext4_xattr_cmp(header, BHDR(bh)) == 0) {
3057 *pce = ce;
3058 return bh;
3059 }
3060 brelse(bh);
3061 ce = mb_cache_entry_find_next(ea_block_cache, ce);
3062 }
3063 return NULL;
3064 }
3065
3066 #define NAME_HASH_SHIFT 5
3067 #define VALUE_HASH_SHIFT 16
3068
3069 /*
3070 * ext4_xattr_hash_entry()
3071 *
3072 * Compute the hash of an extended attribute.
3073 */
3074 static __le32 ext4_xattr_hash_entry(char *name, size_t name_len, __le32 *value,
3075 size_t value_count)
3076 {
3077 __u32 hash = 0;
3078
3079 while (name_len--) {
3080 hash = (hash << NAME_HASH_SHIFT) ^
3081 (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^
3082 *name++;
3083 }
3084 while (value_count--) {
3085 hash = (hash << VALUE_HASH_SHIFT) ^
3086 (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^
3087 le32_to_cpu(*value++);
3088 }
3089 return cpu_to_le32(hash);
3090 }
3091
3092 #undef NAME_HASH_SHIFT
3093 #undef VALUE_HASH_SHIFT
3094
3095 #define BLOCK_HASH_SHIFT 16
3096
3097 /*
3098 * ext4_xattr_rehash()
3099 *
3100 * Re-compute the extended attribute hash value after an entry has changed.
3101 */
3102 static void ext4_xattr_rehash(struct ext4_xattr_header *header)
3103 {
3104 struct ext4_xattr_entry *here;
3105 __u32 hash = 0;
3106
3107 here = ENTRY(header+1);
3108 while (!IS_LAST_ENTRY(here)) {
3109 if (!here->e_hash) {
3110 /* Block is not shared if an entry's hash value == 0 */
3111 hash = 0;
3112 break;
3113 }
3114 hash = (hash << BLOCK_HASH_SHIFT) ^
3115 (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^
3116 le32_to_cpu(here->e_hash);
3117 here = EXT4_XATTR_NEXT(here);
3118 }
3119 header->h_hash = cpu_to_le32(hash);
3120 }
3121
3122 #undef BLOCK_HASH_SHIFT
3123
3124 #define HASH_BUCKET_BITS 10
3125
3126 struct mb_cache *
3127 ext4_xattr_create_cache(void)
3128 {
3129 return mb_cache_create(HASH_BUCKET_BITS);
3130 }
3131
3132 void ext4_xattr_destroy_cache(struct mb_cache *cache)
3133 {
3134 if (cache)
3135 mb_cache_destroy(cache);
3136 }
3137
Linux with added FPC-III support