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Merge branch 'stable/for-linus-5.13' of git://git.kernel.org/pub/scm/linux/kernel...
[mirror_ubuntu-jammy-kernel.git] / fs / ext4 / xattr.c
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 [EXT4_XATTR_INDEX_HURD] = &ext4_xattr_hurd_handler,
97 };
98
99 const struct xattr_handler *ext4_xattr_handlers[] = {
100 &ext4_xattr_user_handler,
101 &ext4_xattr_trusted_handler,
102 #ifdef CONFIG_EXT4_FS_POSIX_ACL
103 &posix_acl_access_xattr_handler,
104 &posix_acl_default_xattr_handler,
105 #endif
106 #ifdef CONFIG_EXT4_FS_SECURITY
107 &ext4_xattr_security_handler,
108 #endif
109 &ext4_xattr_hurd_handler,
110 NULL
111 };
112
113 #define EA_BLOCK_CACHE(inode) (((struct ext4_sb_info *) \
114 inode->i_sb->s_fs_info)->s_ea_block_cache)
115
116 #define EA_INODE_CACHE(inode) (((struct ext4_sb_info *) \
117 inode->i_sb->s_fs_info)->s_ea_inode_cache)
118
119 static int
120 ext4_expand_inode_array(struct ext4_xattr_inode_array **ea_inode_array,
121 struct inode *inode);
122
123 #ifdef CONFIG_LOCKDEP
124 void ext4_xattr_inode_set_class(struct inode *ea_inode)
125 {
126 lockdep_set_subclass(&ea_inode->i_rwsem, 1);
127 }
128 #endif
129
130 static __le32 ext4_xattr_block_csum(struct inode *inode,
131 sector_t block_nr,
132 struct ext4_xattr_header *hdr)
133 {
134 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
135 __u32 csum;
136 __le64 dsk_block_nr = cpu_to_le64(block_nr);
137 __u32 dummy_csum = 0;
138 int offset = offsetof(struct ext4_xattr_header, h_checksum);
139
140 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&dsk_block_nr,
141 sizeof(dsk_block_nr));
142 csum = ext4_chksum(sbi, csum, (__u8 *)hdr, offset);
143 csum = ext4_chksum(sbi, csum, (__u8 *)&dummy_csum, sizeof(dummy_csum));
144 offset += sizeof(dummy_csum);
145 csum = ext4_chksum(sbi, csum, (__u8 *)hdr + offset,
146 EXT4_BLOCK_SIZE(inode->i_sb) - offset);
147
148 return cpu_to_le32(csum);
149 }
150
151 static int ext4_xattr_block_csum_verify(struct inode *inode,
152 struct buffer_head *bh)
153 {
154 struct ext4_xattr_header *hdr = BHDR(bh);
155 int ret = 1;
156
157 if (ext4_has_metadata_csum(inode->i_sb)) {
158 lock_buffer(bh);
159 ret = (hdr->h_checksum == ext4_xattr_block_csum(inode,
160 bh->b_blocknr, hdr));
161 unlock_buffer(bh);
162 }
163 return ret;
164 }
165
166 static void ext4_xattr_block_csum_set(struct inode *inode,
167 struct buffer_head *bh)
168 {
169 if (ext4_has_metadata_csum(inode->i_sb))
170 BHDR(bh)->h_checksum = ext4_xattr_block_csum(inode,
171 bh->b_blocknr, BHDR(bh));
172 }
173
174 static inline const struct xattr_handler *
175 ext4_xattr_handler(int name_index)
176 {
177 const struct xattr_handler *handler = NULL;
178
179 if (name_index > 0 && name_index < ARRAY_SIZE(ext4_xattr_handler_map))
180 handler = ext4_xattr_handler_map[name_index];
181 return handler;
182 }
183
184 static int
185 ext4_xattr_check_entries(struct ext4_xattr_entry *entry, void *end,
186 void *value_start)
187 {
188 struct ext4_xattr_entry *e = entry;
189
190 /* Find the end of the names list */
191 while (!IS_LAST_ENTRY(e)) {
192 struct ext4_xattr_entry *next = EXT4_XATTR_NEXT(e);
193 if ((void *)next >= end)
194 return -EFSCORRUPTED;
195 if (strnlen(e->e_name, e->e_name_len) != e->e_name_len)
196 return -EFSCORRUPTED;
197 e = next;
198 }
199
200 /* Check the values */
201 while (!IS_LAST_ENTRY(entry)) {
202 u32 size = le32_to_cpu(entry->e_value_size);
203
204 if (size > EXT4_XATTR_SIZE_MAX)
205 return -EFSCORRUPTED;
206
207 if (size != 0 && entry->e_value_inum == 0) {
208 u16 offs = le16_to_cpu(entry->e_value_offs);
209 void *value;
210
211 /*
212 * The value cannot overlap the names, and the value
213 * with padding cannot extend beyond 'end'. Check both
214 * the padded and unpadded sizes, since the size may
215 * overflow to 0 when adding padding.
216 */
217 if (offs > end - value_start)
218 return -EFSCORRUPTED;
219 value = value_start + offs;
220 if (value < (void *)e + sizeof(u32) ||
221 size > end - value ||
222 EXT4_XATTR_SIZE(size) > end - value)
223 return -EFSCORRUPTED;
224 }
225 entry = EXT4_XATTR_NEXT(entry);
226 }
227
228 return 0;
229 }
230
231 static inline int
232 __ext4_xattr_check_block(struct inode *inode, struct buffer_head *bh,
233 const char *function, unsigned int line)
234 {
235 int error = -EFSCORRUPTED;
236
237 if (BHDR(bh)->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC) ||
238 BHDR(bh)->h_blocks != cpu_to_le32(1))
239 goto errout;
240 if (buffer_verified(bh))
241 return 0;
242
243 error = -EFSBADCRC;
244 if (!ext4_xattr_block_csum_verify(inode, bh))
245 goto errout;
246 error = ext4_xattr_check_entries(BFIRST(bh), bh->b_data + bh->b_size,
247 bh->b_data);
248 errout:
249 if (error)
250 __ext4_error_inode(inode, function, line, 0, -error,
251 "corrupted xattr block %llu",
252 (unsigned long long) bh->b_blocknr);
253 else
254 set_buffer_verified(bh);
255 return error;
256 }
257
258 #define ext4_xattr_check_block(inode, bh) \
259 __ext4_xattr_check_block((inode), (bh), __func__, __LINE__)
260
261
262 static int
263 __xattr_check_inode(struct inode *inode, struct ext4_xattr_ibody_header *header,
264 void *end, const char *function, unsigned int line)
265 {
266 int error = -EFSCORRUPTED;
267
268 if (end - (void *)header < sizeof(*header) + sizeof(u32) ||
269 (header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC)))
270 goto errout;
271 error = ext4_xattr_check_entries(IFIRST(header), end, IFIRST(header));
272 errout:
273 if (error)
274 __ext4_error_inode(inode, function, line, 0, -error,
275 "corrupted in-inode xattr");
276 return error;
277 }
278
279 #define xattr_check_inode(inode, header, end) \
280 __xattr_check_inode((inode), (header), (end), __func__, __LINE__)
281
282 static int
283 xattr_find_entry(struct inode *inode, struct ext4_xattr_entry **pentry,
284 void *end, int name_index, const char *name, int sorted)
285 {
286 struct ext4_xattr_entry *entry, *next;
287 size_t name_len;
288 int cmp = 1;
289
290 if (name == NULL)
291 return -EINVAL;
292 name_len = strlen(name);
293 for (entry = *pentry; !IS_LAST_ENTRY(entry); entry = next) {
294 next = EXT4_XATTR_NEXT(entry);
295 if ((void *) next >= end) {
296 EXT4_ERROR_INODE(inode, "corrupted xattr entries");
297 return -EFSCORRUPTED;
298 }
299 cmp = name_index - entry->e_name_index;
300 if (!cmp)
301 cmp = name_len - entry->e_name_len;
302 if (!cmp)
303 cmp = memcmp(name, entry->e_name, name_len);
304 if (cmp <= 0 && (sorted || cmp == 0))
305 break;
306 }
307 *pentry = entry;
308 return cmp ? -ENODATA : 0;
309 }
310
311 static u32
312 ext4_xattr_inode_hash(struct ext4_sb_info *sbi, const void *buffer, size_t size)
313 {
314 return ext4_chksum(sbi, sbi->s_csum_seed, buffer, size);
315 }
316
317 static u64 ext4_xattr_inode_get_ref(struct inode *ea_inode)
318 {
319 return ((u64)ea_inode->i_ctime.tv_sec << 32) |
320 (u32) inode_peek_iversion_raw(ea_inode);
321 }
322
323 static void ext4_xattr_inode_set_ref(struct inode *ea_inode, u64 ref_count)
324 {
325 ea_inode->i_ctime.tv_sec = (u32)(ref_count >> 32);
326 inode_set_iversion_raw(ea_inode, ref_count & 0xffffffff);
327 }
328
329 static u32 ext4_xattr_inode_get_hash(struct inode *ea_inode)
330 {
331 return (u32)ea_inode->i_atime.tv_sec;
332 }
333
334 static void ext4_xattr_inode_set_hash(struct inode *ea_inode, u32 hash)
335 {
336 ea_inode->i_atime.tv_sec = hash;
337 }
338
339 /*
340 * Read the EA value from an inode.
341 */
342 static int ext4_xattr_inode_read(struct inode *ea_inode, void *buf, size_t size)
343 {
344 int blocksize = 1 << ea_inode->i_blkbits;
345 int bh_count = (size + blocksize - 1) >> ea_inode->i_blkbits;
346 int tail_size = (size % blocksize) ?: blocksize;
347 struct buffer_head *bhs_inline[8];
348 struct buffer_head **bhs = bhs_inline;
349 int i, ret;
350
351 if (bh_count > ARRAY_SIZE(bhs_inline)) {
352 bhs = kmalloc_array(bh_count, sizeof(*bhs), GFP_NOFS);
353 if (!bhs)
354 return -ENOMEM;
355 }
356
357 ret = ext4_bread_batch(ea_inode, 0 /* block */, bh_count,
358 true /* wait */, bhs);
359 if (ret)
360 goto free_bhs;
361
362 for (i = 0; i < bh_count; i++) {
363 /* There shouldn't be any holes in ea_inode. */
364 if (!bhs[i]) {
365 ret = -EFSCORRUPTED;
366 goto put_bhs;
367 }
368 memcpy((char *)buf + blocksize * i, bhs[i]->b_data,
369 i < bh_count - 1 ? blocksize : tail_size);
370 }
371 ret = 0;
372 put_bhs:
373 for (i = 0; i < bh_count; i++)
374 brelse(bhs[i]);
375 free_bhs:
376 if (bhs != bhs_inline)
377 kfree(bhs);
378 return ret;
379 }
380
381 #define EXT4_XATTR_INODE_GET_PARENT(inode) ((__u32)(inode)->i_mtime.tv_sec)
382
383 static int ext4_xattr_inode_iget(struct inode *parent, unsigned long ea_ino,
384 u32 ea_inode_hash, struct inode **ea_inode)
385 {
386 struct inode *inode;
387 int err;
388
389 inode = ext4_iget(parent->i_sb, ea_ino, EXT4_IGET_NORMAL);
390 if (IS_ERR(inode)) {
391 err = PTR_ERR(inode);
392 ext4_error(parent->i_sb,
393 "error while reading EA inode %lu err=%d", ea_ino,
394 err);
395 return err;
396 }
397
398 if (is_bad_inode(inode)) {
399 ext4_error(parent->i_sb,
400 "error while reading EA inode %lu is_bad_inode",
401 ea_ino);
402 err = -EIO;
403 goto error;
404 }
405
406 if (!(EXT4_I(inode)->i_flags & EXT4_EA_INODE_FL)) {
407 ext4_error(parent->i_sb,
408 "EA inode %lu does not have EXT4_EA_INODE_FL flag",
409 ea_ino);
410 err = -EINVAL;
411 goto error;
412 }
413
414 ext4_xattr_inode_set_class(inode);
415
416 /*
417 * Check whether this is an old Lustre-style xattr inode. Lustre
418 * implementation does not have hash validation, rather it has a
419 * backpointer from ea_inode to the parent inode.
420 */
421 if (ea_inode_hash != ext4_xattr_inode_get_hash(inode) &&
422 EXT4_XATTR_INODE_GET_PARENT(inode) == parent->i_ino &&
423 inode->i_generation == parent->i_generation) {
424 ext4_set_inode_state(inode, EXT4_STATE_LUSTRE_EA_INODE);
425 ext4_xattr_inode_set_ref(inode, 1);
426 } else {
427 inode_lock(inode);
428 inode->i_flags |= S_NOQUOTA;
429 inode_unlock(inode);
430 }
431
432 *ea_inode = inode;
433 return 0;
434 error:
435 iput(inode);
436 return err;
437 }
438
439 static int
440 ext4_xattr_inode_verify_hashes(struct inode *ea_inode,
441 struct ext4_xattr_entry *entry, void *buffer,
442 size_t size)
443 {
444 u32 hash;
445
446 /* Verify stored hash matches calculated hash. */
447 hash = ext4_xattr_inode_hash(EXT4_SB(ea_inode->i_sb), buffer, size);
448 if (hash != ext4_xattr_inode_get_hash(ea_inode))
449 return -EFSCORRUPTED;
450
451 if (entry) {
452 __le32 e_hash, tmp_data;
453
454 /* Verify entry hash. */
455 tmp_data = cpu_to_le32(hash);
456 e_hash = ext4_xattr_hash_entry(entry->e_name, entry->e_name_len,
457 &tmp_data, 1);
458 if (e_hash != entry->e_hash)
459 return -EFSCORRUPTED;
460 }
461 return 0;
462 }
463
464 /*
465 * Read xattr value from the EA inode.
466 */
467 static int
468 ext4_xattr_inode_get(struct inode *inode, struct ext4_xattr_entry *entry,
469 void *buffer, size_t size)
470 {
471 struct mb_cache *ea_inode_cache = EA_INODE_CACHE(inode);
472 struct inode *ea_inode;
473 int err;
474
475 err = ext4_xattr_inode_iget(inode, le32_to_cpu(entry->e_value_inum),
476 le32_to_cpu(entry->e_hash), &ea_inode);
477 if (err) {
478 ea_inode = NULL;
479 goto out;
480 }
481
482 if (i_size_read(ea_inode) != size) {
483 ext4_warning_inode(ea_inode,
484 "ea_inode file size=%llu entry size=%zu",
485 i_size_read(ea_inode), size);
486 err = -EFSCORRUPTED;
487 goto out;
488 }
489
490 err = ext4_xattr_inode_read(ea_inode, buffer, size);
491 if (err)
492 goto out;
493
494 if (!ext4_test_inode_state(ea_inode, EXT4_STATE_LUSTRE_EA_INODE)) {
495 err = ext4_xattr_inode_verify_hashes(ea_inode, entry, buffer,
496 size);
497 if (err) {
498 ext4_warning_inode(ea_inode,
499 "EA inode hash validation failed");
500 goto out;
501 }
502
503 if (ea_inode_cache)
504 mb_cache_entry_create(ea_inode_cache, GFP_NOFS,
505 ext4_xattr_inode_get_hash(ea_inode),
506 ea_inode->i_ino, true /* reusable */);
507 }
508 out:
509 iput(ea_inode);
510 return err;
511 }
512
513 static int
514 ext4_xattr_block_get(struct inode *inode, int name_index, const char *name,
515 void *buffer, size_t buffer_size)
516 {
517 struct buffer_head *bh = NULL;
518 struct ext4_xattr_entry *entry;
519 size_t size;
520 void *end;
521 int error;
522 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
523
524 ea_idebug(inode, "name=%d.%s, buffer=%p, buffer_size=%ld",
525 name_index, name, buffer, (long)buffer_size);
526
527 if (!EXT4_I(inode)->i_file_acl)
528 return -ENODATA;
529 ea_idebug(inode, "reading block %llu",
530 (unsigned long long)EXT4_I(inode)->i_file_acl);
531 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
532 if (IS_ERR(bh))
533 return PTR_ERR(bh);
534 ea_bdebug(bh, "b_count=%d, refcount=%d",
535 atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount));
536 error = ext4_xattr_check_block(inode, bh);
537 if (error)
538 goto cleanup;
539 ext4_xattr_block_cache_insert(ea_block_cache, bh);
540 entry = BFIRST(bh);
541 end = bh->b_data + bh->b_size;
542 error = xattr_find_entry(inode, &entry, end, name_index, name, 1);
543 if (error)
544 goto cleanup;
545 size = le32_to_cpu(entry->e_value_size);
546 error = -ERANGE;
547 if (unlikely(size > EXT4_XATTR_SIZE_MAX))
548 goto cleanup;
549 if (buffer) {
550 if (size > buffer_size)
551 goto cleanup;
552 if (entry->e_value_inum) {
553 error = ext4_xattr_inode_get(inode, entry, buffer,
554 size);
555 if (error)
556 goto cleanup;
557 } else {
558 u16 offset = le16_to_cpu(entry->e_value_offs);
559 void *p = bh->b_data + offset;
560
561 if (unlikely(p + size > end))
562 goto cleanup;
563 memcpy(buffer, p, size);
564 }
565 }
566 error = size;
567
568 cleanup:
569 brelse(bh);
570 return error;
571 }
572
573 int
574 ext4_xattr_ibody_get(struct inode *inode, int name_index, const char *name,
575 void *buffer, size_t buffer_size)
576 {
577 struct ext4_xattr_ibody_header *header;
578 struct ext4_xattr_entry *entry;
579 struct ext4_inode *raw_inode;
580 struct ext4_iloc iloc;
581 size_t size;
582 void *end;
583 int error;
584
585 if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR))
586 return -ENODATA;
587 error = ext4_get_inode_loc(inode, &iloc);
588 if (error)
589 return error;
590 raw_inode = ext4_raw_inode(&iloc);
591 header = IHDR(inode, raw_inode);
592 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
593 error = xattr_check_inode(inode, header, end);
594 if (error)
595 goto cleanup;
596 entry = IFIRST(header);
597 error = xattr_find_entry(inode, &entry, end, name_index, name, 0);
598 if (error)
599 goto cleanup;
600 size = le32_to_cpu(entry->e_value_size);
601 error = -ERANGE;
602 if (unlikely(size > EXT4_XATTR_SIZE_MAX))
603 goto cleanup;
604 if (buffer) {
605 if (size > buffer_size)
606 goto cleanup;
607 if (entry->e_value_inum) {
608 error = ext4_xattr_inode_get(inode, entry, buffer,
609 size);
610 if (error)
611 goto cleanup;
612 } else {
613 u16 offset = le16_to_cpu(entry->e_value_offs);
614 void *p = (void *)IFIRST(header) + offset;
615
616 if (unlikely(p + size > end))
617 goto cleanup;
618 memcpy(buffer, p, size);
619 }
620 }
621 error = size;
622
623 cleanup:
624 brelse(iloc.bh);
625 return error;
626 }
627
628 /*
629 * ext4_xattr_get()
630 *
631 * Copy an extended attribute into the buffer
632 * provided, or compute the buffer size required.
633 * Buffer is NULL to compute the size of the buffer required.
634 *
635 * Returns a negative error number on failure, or the number of bytes
636 * used / required on success.
637 */
638 int
639 ext4_xattr_get(struct inode *inode, int name_index, const char *name,
640 void *buffer, size_t buffer_size)
641 {
642 int error;
643
644 if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
645 return -EIO;
646
647 if (strlen(name) > 255)
648 return -ERANGE;
649
650 down_read(&EXT4_I(inode)->xattr_sem);
651 error = ext4_xattr_ibody_get(inode, name_index, name, buffer,
652 buffer_size);
653 if (error == -ENODATA)
654 error = ext4_xattr_block_get(inode, name_index, name, buffer,
655 buffer_size);
656 up_read(&EXT4_I(inode)->xattr_sem);
657 return error;
658 }
659
660 static int
661 ext4_xattr_list_entries(struct dentry *dentry, struct ext4_xattr_entry *entry,
662 char *buffer, size_t buffer_size)
663 {
664 size_t rest = buffer_size;
665
666 for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) {
667 const struct xattr_handler *handler =
668 ext4_xattr_handler(entry->e_name_index);
669
670 if (handler && (!handler->list || handler->list(dentry))) {
671 const char *prefix = handler->prefix ?: handler->name;
672 size_t prefix_len = strlen(prefix);
673 size_t size = prefix_len + entry->e_name_len + 1;
674
675 if (buffer) {
676 if (size > rest)
677 return -ERANGE;
678 memcpy(buffer, prefix, prefix_len);
679 buffer += prefix_len;
680 memcpy(buffer, entry->e_name, entry->e_name_len);
681 buffer += entry->e_name_len;
682 *buffer++ = 0;
683 }
684 rest -= size;
685 }
686 }
687 return buffer_size - rest; /* total size */
688 }
689
690 static int
691 ext4_xattr_block_list(struct dentry *dentry, char *buffer, size_t buffer_size)
692 {
693 struct inode *inode = d_inode(dentry);
694 struct buffer_head *bh = NULL;
695 int error;
696
697 ea_idebug(inode, "buffer=%p, buffer_size=%ld",
698 buffer, (long)buffer_size);
699
700 if (!EXT4_I(inode)->i_file_acl)
701 return 0;
702 ea_idebug(inode, "reading block %llu",
703 (unsigned long long)EXT4_I(inode)->i_file_acl);
704 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
705 if (IS_ERR(bh))
706 return PTR_ERR(bh);
707 ea_bdebug(bh, "b_count=%d, refcount=%d",
708 atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount));
709 error = ext4_xattr_check_block(inode, bh);
710 if (error)
711 goto cleanup;
712 ext4_xattr_block_cache_insert(EA_BLOCK_CACHE(inode), bh);
713 error = ext4_xattr_list_entries(dentry, BFIRST(bh), buffer,
714 buffer_size);
715 cleanup:
716 brelse(bh);
717 return error;
718 }
719
720 static int
721 ext4_xattr_ibody_list(struct dentry *dentry, char *buffer, size_t buffer_size)
722 {
723 struct inode *inode = d_inode(dentry);
724 struct ext4_xattr_ibody_header *header;
725 struct ext4_inode *raw_inode;
726 struct ext4_iloc iloc;
727 void *end;
728 int error;
729
730 if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR))
731 return 0;
732 error = ext4_get_inode_loc(inode, &iloc);
733 if (error)
734 return error;
735 raw_inode = ext4_raw_inode(&iloc);
736 header = IHDR(inode, raw_inode);
737 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
738 error = xattr_check_inode(inode, header, end);
739 if (error)
740 goto cleanup;
741 error = ext4_xattr_list_entries(dentry, IFIRST(header),
742 buffer, buffer_size);
743
744 cleanup:
745 brelse(iloc.bh);
746 return error;
747 }
748
749 /*
750 * Inode operation listxattr()
751 *
752 * d_inode(dentry)->i_rwsem: don't care
753 *
754 * Copy a list of attribute names into the buffer
755 * provided, or compute the buffer size required.
756 * Buffer is NULL to compute the size of the buffer required.
757 *
758 * Returns a negative error number on failure, or the number of bytes
759 * used / required on success.
760 */
761 ssize_t
762 ext4_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
763 {
764 int ret, ret2;
765
766 down_read(&EXT4_I(d_inode(dentry))->xattr_sem);
767 ret = ret2 = ext4_xattr_ibody_list(dentry, buffer, buffer_size);
768 if (ret < 0)
769 goto errout;
770 if (buffer) {
771 buffer += ret;
772 buffer_size -= ret;
773 }
774 ret = ext4_xattr_block_list(dentry, buffer, buffer_size);
775 if (ret < 0)
776 goto errout;
777 ret += ret2;
778 errout:
779 up_read(&EXT4_I(d_inode(dentry))->xattr_sem);
780 return ret;
781 }
782
783 /*
784 * If the EXT4_FEATURE_COMPAT_EXT_ATTR feature of this file system is
785 * not set, set it.
786 */
787 static void ext4_xattr_update_super_block(handle_t *handle,
788 struct super_block *sb)
789 {
790 if (ext4_has_feature_xattr(sb))
791 return;
792
793 BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access");
794 if (ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh) == 0) {
795 lock_buffer(EXT4_SB(sb)->s_sbh);
796 ext4_set_feature_xattr(sb);
797 ext4_superblock_csum_set(sb);
798 unlock_buffer(EXT4_SB(sb)->s_sbh);
799 ext4_handle_dirty_metadata(handle, NULL, EXT4_SB(sb)->s_sbh);
800 }
801 }
802
803 int ext4_get_inode_usage(struct inode *inode, qsize_t *usage)
804 {
805 struct ext4_iloc iloc = { .bh = NULL };
806 struct buffer_head *bh = NULL;
807 struct ext4_inode *raw_inode;
808 struct ext4_xattr_ibody_header *header;
809 struct ext4_xattr_entry *entry;
810 qsize_t ea_inode_refs = 0;
811 void *end;
812 int ret;
813
814 lockdep_assert_held_read(&EXT4_I(inode)->xattr_sem);
815
816 if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
817 ret = ext4_get_inode_loc(inode, &iloc);
818 if (ret)
819 goto out;
820 raw_inode = ext4_raw_inode(&iloc);
821 header = IHDR(inode, raw_inode);
822 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
823 ret = xattr_check_inode(inode, header, end);
824 if (ret)
825 goto out;
826
827 for (entry = IFIRST(header); !IS_LAST_ENTRY(entry);
828 entry = EXT4_XATTR_NEXT(entry))
829 if (entry->e_value_inum)
830 ea_inode_refs++;
831 }
832
833 if (EXT4_I(inode)->i_file_acl) {
834 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
835 if (IS_ERR(bh)) {
836 ret = PTR_ERR(bh);
837 bh = NULL;
838 goto out;
839 }
840
841 ret = ext4_xattr_check_block(inode, bh);
842 if (ret)
843 goto out;
844
845 for (entry = BFIRST(bh); !IS_LAST_ENTRY(entry);
846 entry = EXT4_XATTR_NEXT(entry))
847 if (entry->e_value_inum)
848 ea_inode_refs++;
849 }
850 *usage = ea_inode_refs + 1;
851 ret = 0;
852 out:
853 brelse(iloc.bh);
854 brelse(bh);
855 return ret;
856 }
857
858 static inline size_t round_up_cluster(struct inode *inode, size_t length)
859 {
860 struct super_block *sb = inode->i_sb;
861 size_t cluster_size = 1 << (EXT4_SB(sb)->s_cluster_bits +
862 inode->i_blkbits);
863 size_t mask = ~(cluster_size - 1);
864
865 return (length + cluster_size - 1) & mask;
866 }
867
868 static int ext4_xattr_inode_alloc_quota(struct inode *inode, size_t len)
869 {
870 int err;
871
872 err = dquot_alloc_inode(inode);
873 if (err)
874 return err;
875 err = dquot_alloc_space_nodirty(inode, round_up_cluster(inode, len));
876 if (err)
877 dquot_free_inode(inode);
878 return err;
879 }
880
881 static void ext4_xattr_inode_free_quota(struct inode *parent,
882 struct inode *ea_inode,
883 size_t len)
884 {
885 if (ea_inode &&
886 ext4_test_inode_state(ea_inode, EXT4_STATE_LUSTRE_EA_INODE))
887 return;
888 dquot_free_space_nodirty(parent, round_up_cluster(parent, len));
889 dquot_free_inode(parent);
890 }
891
892 int __ext4_xattr_set_credits(struct super_block *sb, struct inode *inode,
893 struct buffer_head *block_bh, size_t value_len,
894 bool is_create)
895 {
896 int credits;
897 int blocks;
898
899 /*
900 * 1) Owner inode update
901 * 2) Ref count update on old xattr block
902 * 3) new xattr block
903 * 4) block bitmap update for new xattr block
904 * 5) group descriptor for new xattr block
905 * 6) block bitmap update for old xattr block
906 * 7) group descriptor for old block
907 *
908 * 6 & 7 can happen if we have two racing threads T_a and T_b
909 * which are each trying to set an xattr on inodes I_a and I_b
910 * which were both initially sharing an xattr block.
911 */
912 credits = 7;
913
914 /* Quota updates. */
915 credits += EXT4_MAXQUOTAS_TRANS_BLOCKS(sb);
916
917 /*
918 * In case of inline data, we may push out the data to a block,
919 * so we need to reserve credits for this eventuality
920 */
921 if (inode && ext4_has_inline_data(inode))
922 credits += ext4_writepage_trans_blocks(inode) + 1;
923
924 /* We are done if ea_inode feature is not enabled. */
925 if (!ext4_has_feature_ea_inode(sb))
926 return credits;
927
928 /* New ea_inode, inode map, block bitmap, group descriptor. */
929 credits += 4;
930
931 /* Data blocks. */
932 blocks = (value_len + sb->s_blocksize - 1) >> sb->s_blocksize_bits;
933
934 /* Indirection block or one level of extent tree. */
935 blocks += 1;
936
937 /* Block bitmap and group descriptor updates for each block. */
938 credits += blocks * 2;
939
940 /* Blocks themselves. */
941 credits += blocks;
942
943 if (!is_create) {
944 /* Dereference ea_inode holding old xattr value.
945 * Old ea_inode, inode map, block bitmap, group descriptor.
946 */
947 credits += 4;
948
949 /* Data blocks for old ea_inode. */
950 blocks = XATTR_SIZE_MAX >> sb->s_blocksize_bits;
951
952 /* Indirection block or one level of extent tree for old
953 * ea_inode.
954 */
955 blocks += 1;
956
957 /* Block bitmap and group descriptor updates for each block. */
958 credits += blocks * 2;
959 }
960
961 /* We may need to clone the existing xattr block in which case we need
962 * to increment ref counts for existing ea_inodes referenced by it.
963 */
964 if (block_bh) {
965 struct ext4_xattr_entry *entry = BFIRST(block_bh);
966
967 for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry))
968 if (entry->e_value_inum)
969 /* Ref count update on ea_inode. */
970 credits += 1;
971 }
972 return credits;
973 }
974
975 static int ext4_xattr_inode_update_ref(handle_t *handle, struct inode *ea_inode,
976 int ref_change)
977 {
978 struct mb_cache *ea_inode_cache = EA_INODE_CACHE(ea_inode);
979 struct ext4_iloc iloc;
980 s64 ref_count;
981 u32 hash;
982 int ret;
983
984 inode_lock(ea_inode);
985
986 ret = ext4_reserve_inode_write(handle, ea_inode, &iloc);
987 if (ret)
988 goto out;
989
990 ref_count = ext4_xattr_inode_get_ref(ea_inode);
991 ref_count += ref_change;
992 ext4_xattr_inode_set_ref(ea_inode, ref_count);
993
994 if (ref_change > 0) {
995 WARN_ONCE(ref_count <= 0, "EA inode %lu ref_count=%lld",
996 ea_inode->i_ino, ref_count);
997
998 if (ref_count == 1) {
999 WARN_ONCE(ea_inode->i_nlink, "EA inode %lu i_nlink=%u",
1000 ea_inode->i_ino, ea_inode->i_nlink);
1001
1002 set_nlink(ea_inode, 1);
1003 ext4_orphan_del(handle, ea_inode);
1004
1005 if (ea_inode_cache) {
1006 hash = ext4_xattr_inode_get_hash(ea_inode);
1007 mb_cache_entry_create(ea_inode_cache,
1008 GFP_NOFS, hash,
1009 ea_inode->i_ino,
1010 true /* reusable */);
1011 }
1012 }
1013 } else {
1014 WARN_ONCE(ref_count < 0, "EA inode %lu ref_count=%lld",
1015 ea_inode->i_ino, ref_count);
1016
1017 if (ref_count == 0) {
1018 WARN_ONCE(ea_inode->i_nlink != 1,
1019 "EA inode %lu i_nlink=%u",
1020 ea_inode->i_ino, ea_inode->i_nlink);
1021
1022 clear_nlink(ea_inode);
1023 ext4_orphan_add(handle, ea_inode);
1024
1025 if (ea_inode_cache) {
1026 hash = ext4_xattr_inode_get_hash(ea_inode);
1027 mb_cache_entry_delete(ea_inode_cache, hash,
1028 ea_inode->i_ino);
1029 }
1030 }
1031 }
1032
1033 ret = ext4_mark_iloc_dirty(handle, ea_inode, &iloc);
1034 if (ret)
1035 ext4_warning_inode(ea_inode,
1036 "ext4_mark_iloc_dirty() failed ret=%d", ret);
1037 out:
1038 inode_unlock(ea_inode);
1039 return ret;
1040 }
1041
1042 static int ext4_xattr_inode_inc_ref(handle_t *handle, struct inode *ea_inode)
1043 {
1044 return ext4_xattr_inode_update_ref(handle, ea_inode, 1);
1045 }
1046
1047 static int ext4_xattr_inode_dec_ref(handle_t *handle, struct inode *ea_inode)
1048 {
1049 return ext4_xattr_inode_update_ref(handle, ea_inode, -1);
1050 }
1051
1052 static int ext4_xattr_inode_inc_ref_all(handle_t *handle, struct inode *parent,
1053 struct ext4_xattr_entry *first)
1054 {
1055 struct inode *ea_inode;
1056 struct ext4_xattr_entry *entry;
1057 struct ext4_xattr_entry *failed_entry;
1058 unsigned int ea_ino;
1059 int err, saved_err;
1060
1061 for (entry = first; !IS_LAST_ENTRY(entry);
1062 entry = EXT4_XATTR_NEXT(entry)) {
1063 if (!entry->e_value_inum)
1064 continue;
1065 ea_ino = le32_to_cpu(entry->e_value_inum);
1066 err = ext4_xattr_inode_iget(parent, ea_ino,
1067 le32_to_cpu(entry->e_hash),
1068 &ea_inode);
1069 if (err)
1070 goto cleanup;
1071 err = ext4_xattr_inode_inc_ref(handle, ea_inode);
1072 if (err) {
1073 ext4_warning_inode(ea_inode, "inc ref error %d", err);
1074 iput(ea_inode);
1075 goto cleanup;
1076 }
1077 iput(ea_inode);
1078 }
1079 return 0;
1080
1081 cleanup:
1082 saved_err = err;
1083 failed_entry = entry;
1084
1085 for (entry = first; entry != failed_entry;
1086 entry = EXT4_XATTR_NEXT(entry)) {
1087 if (!entry->e_value_inum)
1088 continue;
1089 ea_ino = le32_to_cpu(entry->e_value_inum);
1090 err = ext4_xattr_inode_iget(parent, ea_ino,
1091 le32_to_cpu(entry->e_hash),
1092 &ea_inode);
1093 if (err) {
1094 ext4_warning(parent->i_sb,
1095 "cleanup ea_ino %u iget error %d", ea_ino,
1096 err);
1097 continue;
1098 }
1099 err = ext4_xattr_inode_dec_ref(handle, ea_inode);
1100 if (err)
1101 ext4_warning_inode(ea_inode, "cleanup dec ref error %d",
1102 err);
1103 iput(ea_inode);
1104 }
1105 return saved_err;
1106 }
1107
1108 static int ext4_xattr_restart_fn(handle_t *handle, struct inode *inode,
1109 struct buffer_head *bh, bool block_csum, bool dirty)
1110 {
1111 int error;
1112
1113 if (bh && dirty) {
1114 if (block_csum)
1115 ext4_xattr_block_csum_set(inode, bh);
1116 error = ext4_handle_dirty_metadata(handle, NULL, bh);
1117 if (error) {
1118 ext4_warning(inode->i_sb, "Handle metadata (error %d)",
1119 error);
1120 return error;
1121 }
1122 }
1123 return 0;
1124 }
1125
1126 static void
1127 ext4_xattr_inode_dec_ref_all(handle_t *handle, struct inode *parent,
1128 struct buffer_head *bh,
1129 struct ext4_xattr_entry *first, bool block_csum,
1130 struct ext4_xattr_inode_array **ea_inode_array,
1131 int extra_credits, bool skip_quota)
1132 {
1133 struct inode *ea_inode;
1134 struct ext4_xattr_entry *entry;
1135 bool dirty = false;
1136 unsigned int ea_ino;
1137 int err;
1138 int credits;
1139
1140 /* One credit for dec ref on ea_inode, one for orphan list addition, */
1141 credits = 2 + extra_credits;
1142
1143 for (entry = first; !IS_LAST_ENTRY(entry);
1144 entry = EXT4_XATTR_NEXT(entry)) {
1145 if (!entry->e_value_inum)
1146 continue;
1147 ea_ino = le32_to_cpu(entry->e_value_inum);
1148 err = ext4_xattr_inode_iget(parent, ea_ino,
1149 le32_to_cpu(entry->e_hash),
1150 &ea_inode);
1151 if (err)
1152 continue;
1153
1154 err = ext4_expand_inode_array(ea_inode_array, ea_inode);
1155 if (err) {
1156 ext4_warning_inode(ea_inode,
1157 "Expand inode array err=%d", err);
1158 iput(ea_inode);
1159 continue;
1160 }
1161
1162 err = ext4_journal_ensure_credits_fn(handle, credits, credits,
1163 ext4_free_metadata_revoke_credits(parent->i_sb, 1),
1164 ext4_xattr_restart_fn(handle, parent, bh, block_csum,
1165 dirty));
1166 if (err < 0) {
1167 ext4_warning_inode(ea_inode, "Ensure credits err=%d",
1168 err);
1169 continue;
1170 }
1171 if (err > 0) {
1172 err = ext4_journal_get_write_access(handle, bh);
1173 if (err) {
1174 ext4_warning_inode(ea_inode,
1175 "Re-get write access err=%d",
1176 err);
1177 continue;
1178 }
1179 }
1180
1181 err = ext4_xattr_inode_dec_ref(handle, ea_inode);
1182 if (err) {
1183 ext4_warning_inode(ea_inode, "ea_inode dec ref err=%d",
1184 err);
1185 continue;
1186 }
1187
1188 if (!skip_quota)
1189 ext4_xattr_inode_free_quota(parent, ea_inode,
1190 le32_to_cpu(entry->e_value_size));
1191
1192 /*
1193 * Forget about ea_inode within the same transaction that
1194 * decrements the ref count. This avoids duplicate decrements in
1195 * case the rest of the work spills over to subsequent
1196 * transactions.
1197 */
1198 entry->e_value_inum = 0;
1199 entry->e_value_size = 0;
1200
1201 dirty = true;
1202 }
1203
1204 if (dirty) {
1205 /*
1206 * Note that we are deliberately skipping csum calculation for
1207 * the final update because we do not expect any journal
1208 * restarts until xattr block is freed.
1209 */
1210
1211 err = ext4_handle_dirty_metadata(handle, NULL, bh);
1212 if (err)
1213 ext4_warning_inode(parent,
1214 "handle dirty metadata err=%d", err);
1215 }
1216 }
1217
1218 /*
1219 * Release the xattr block BH: If the reference count is > 1, decrement it;
1220 * otherwise free the block.
1221 */
1222 static void
1223 ext4_xattr_release_block(handle_t *handle, struct inode *inode,
1224 struct buffer_head *bh,
1225 struct ext4_xattr_inode_array **ea_inode_array,
1226 int extra_credits)
1227 {
1228 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
1229 u32 hash, ref;
1230 int error = 0;
1231
1232 BUFFER_TRACE(bh, "get_write_access");
1233 error = ext4_journal_get_write_access(handle, bh);
1234 if (error)
1235 goto out;
1236
1237 lock_buffer(bh);
1238 hash = le32_to_cpu(BHDR(bh)->h_hash);
1239 ref = le32_to_cpu(BHDR(bh)->h_refcount);
1240 if (ref == 1) {
1241 ea_bdebug(bh, "refcount now=0; freeing");
1242 /*
1243 * This must happen under buffer lock for
1244 * ext4_xattr_block_set() to reliably detect freed block
1245 */
1246 if (ea_block_cache)
1247 mb_cache_entry_delete(ea_block_cache, hash,
1248 bh->b_blocknr);
1249 get_bh(bh);
1250 unlock_buffer(bh);
1251
1252 if (ext4_has_feature_ea_inode(inode->i_sb))
1253 ext4_xattr_inode_dec_ref_all(handle, inode, bh,
1254 BFIRST(bh),
1255 true /* block_csum */,
1256 ea_inode_array,
1257 extra_credits,
1258 true /* skip_quota */);
1259 ext4_free_blocks(handle, inode, bh, 0, 1,
1260 EXT4_FREE_BLOCKS_METADATA |
1261 EXT4_FREE_BLOCKS_FORGET);
1262 } else {
1263 ref--;
1264 BHDR(bh)->h_refcount = cpu_to_le32(ref);
1265 if (ref == EXT4_XATTR_REFCOUNT_MAX - 1) {
1266 struct mb_cache_entry *ce;
1267
1268 if (ea_block_cache) {
1269 ce = mb_cache_entry_get(ea_block_cache, hash,
1270 bh->b_blocknr);
1271 if (ce) {
1272 ce->e_reusable = 1;
1273 mb_cache_entry_put(ea_block_cache, ce);
1274 }
1275 }
1276 }
1277
1278 ext4_xattr_block_csum_set(inode, bh);
1279 /*
1280 * Beware of this ugliness: Releasing of xattr block references
1281 * from different inodes can race and so we have to protect
1282 * from a race where someone else frees the block (and releases
1283 * its journal_head) before we are done dirtying the buffer. In
1284 * nojournal mode this race is harmless and we actually cannot
1285 * call ext4_handle_dirty_metadata() with locked buffer as
1286 * that function can call sync_dirty_buffer() so for that case
1287 * we handle the dirtying after unlocking the buffer.
1288 */
1289 if (ext4_handle_valid(handle))
1290 error = ext4_handle_dirty_metadata(handle, inode, bh);
1291 unlock_buffer(bh);
1292 if (!ext4_handle_valid(handle))
1293 error = ext4_handle_dirty_metadata(handle, inode, bh);
1294 if (IS_SYNC(inode))
1295 ext4_handle_sync(handle);
1296 dquot_free_block(inode, EXT4_C2B(EXT4_SB(inode->i_sb), 1));
1297 ea_bdebug(bh, "refcount now=%d; releasing",
1298 le32_to_cpu(BHDR(bh)->h_refcount));
1299 }
1300 out:
1301 ext4_std_error(inode->i_sb, error);
1302 return;
1303 }
1304
1305 /*
1306 * Find the available free space for EAs. This also returns the total number of
1307 * bytes used by EA entries.
1308 */
1309 static size_t ext4_xattr_free_space(struct ext4_xattr_entry *last,
1310 size_t *min_offs, void *base, int *total)
1311 {
1312 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
1313 if (!last->e_value_inum && last->e_value_size) {
1314 size_t offs = le16_to_cpu(last->e_value_offs);
1315 if (offs < *min_offs)
1316 *min_offs = offs;
1317 }
1318 if (total)
1319 *total += EXT4_XATTR_LEN(last->e_name_len);
1320 }
1321 return (*min_offs - ((void *)last - base) - sizeof(__u32));
1322 }
1323
1324 /*
1325 * Write the value of the EA in an inode.
1326 */
1327 static int ext4_xattr_inode_write(handle_t *handle, struct inode *ea_inode,
1328 const void *buf, int bufsize)
1329 {
1330 struct buffer_head *bh = NULL;
1331 unsigned long block = 0;
1332 int blocksize = ea_inode->i_sb->s_blocksize;
1333 int max_blocks = (bufsize + blocksize - 1) >> ea_inode->i_blkbits;
1334 int csize, wsize = 0;
1335 int ret = 0, ret2 = 0;
1336 int retries = 0;
1337
1338 retry:
1339 while (ret >= 0 && ret < max_blocks) {
1340 struct ext4_map_blocks map;
1341 map.m_lblk = block += ret;
1342 map.m_len = max_blocks -= ret;
1343
1344 ret = ext4_map_blocks(handle, ea_inode, &map,
1345 EXT4_GET_BLOCKS_CREATE);
1346 if (ret <= 0) {
1347 ext4_mark_inode_dirty(handle, ea_inode);
1348 if (ret == -ENOSPC &&
1349 ext4_should_retry_alloc(ea_inode->i_sb, &retries)) {
1350 ret = 0;
1351 goto retry;
1352 }
1353 break;
1354 }
1355 }
1356
1357 if (ret < 0)
1358 return ret;
1359
1360 block = 0;
1361 while (wsize < bufsize) {
1362 brelse(bh);
1363 csize = (bufsize - wsize) > blocksize ? blocksize :
1364 bufsize - wsize;
1365 bh = ext4_getblk(handle, ea_inode, block, 0);
1366 if (IS_ERR(bh))
1367 return PTR_ERR(bh);
1368 if (!bh) {
1369 WARN_ON_ONCE(1);
1370 EXT4_ERROR_INODE(ea_inode,
1371 "ext4_getblk() return bh = NULL");
1372 return -EFSCORRUPTED;
1373 }
1374 ret = ext4_journal_get_write_access(handle, bh);
1375 if (ret)
1376 goto out;
1377
1378 memcpy(bh->b_data, buf, csize);
1379 set_buffer_uptodate(bh);
1380 ext4_handle_dirty_metadata(handle, ea_inode, bh);
1381
1382 buf += csize;
1383 wsize += csize;
1384 block += 1;
1385 }
1386
1387 inode_lock(ea_inode);
1388 i_size_write(ea_inode, wsize);
1389 ext4_update_i_disksize(ea_inode, wsize);
1390 inode_unlock(ea_inode);
1391
1392 ret2 = ext4_mark_inode_dirty(handle, ea_inode);
1393 if (unlikely(ret2 && !ret))
1394 ret = ret2;
1395
1396 out:
1397 brelse(bh);
1398
1399 return ret;
1400 }
1401
1402 /*
1403 * Create an inode to store the value of a large EA.
1404 */
1405 static struct inode *ext4_xattr_inode_create(handle_t *handle,
1406 struct inode *inode, u32 hash)
1407 {
1408 struct inode *ea_inode = NULL;
1409 uid_t owner[2] = { i_uid_read(inode), i_gid_read(inode) };
1410 int err;
1411
1412 /*
1413 * Let the next inode be the goal, so we try and allocate the EA inode
1414 * in the same group, or nearby one.
1415 */
1416 ea_inode = ext4_new_inode(handle, inode->i_sb->s_root->d_inode,
1417 S_IFREG | 0600, NULL, inode->i_ino + 1, owner,
1418 EXT4_EA_INODE_FL);
1419 if (!IS_ERR(ea_inode)) {
1420 ea_inode->i_op = &ext4_file_inode_operations;
1421 ea_inode->i_fop = &ext4_file_operations;
1422 ext4_set_aops(ea_inode);
1423 ext4_xattr_inode_set_class(ea_inode);
1424 unlock_new_inode(ea_inode);
1425 ext4_xattr_inode_set_ref(ea_inode, 1);
1426 ext4_xattr_inode_set_hash(ea_inode, hash);
1427 err = ext4_mark_inode_dirty(handle, ea_inode);
1428 if (!err)
1429 err = ext4_inode_attach_jinode(ea_inode);
1430 if (err) {
1431 iput(ea_inode);
1432 return ERR_PTR(err);
1433 }
1434
1435 /*
1436 * Xattr inodes are shared therefore quota charging is performed
1437 * at a higher level.
1438 */
1439 dquot_free_inode(ea_inode);
1440 dquot_drop(ea_inode);
1441 inode_lock(ea_inode);
1442 ea_inode->i_flags |= S_NOQUOTA;
1443 inode_unlock(ea_inode);
1444 }
1445
1446 return ea_inode;
1447 }
1448
1449 static struct inode *
1450 ext4_xattr_inode_cache_find(struct inode *inode, const void *value,
1451 size_t value_len, u32 hash)
1452 {
1453 struct inode *ea_inode;
1454 struct mb_cache_entry *ce;
1455 struct mb_cache *ea_inode_cache = EA_INODE_CACHE(inode);
1456 void *ea_data;
1457
1458 if (!ea_inode_cache)
1459 return NULL;
1460
1461 ce = mb_cache_entry_find_first(ea_inode_cache, hash);
1462 if (!ce)
1463 return NULL;
1464
1465 WARN_ON_ONCE(ext4_handle_valid(journal_current_handle()) &&
1466 !(current->flags & PF_MEMALLOC_NOFS));
1467
1468 ea_data = kvmalloc(value_len, GFP_KERNEL);
1469 if (!ea_data) {
1470 mb_cache_entry_put(ea_inode_cache, ce);
1471 return NULL;
1472 }
1473
1474 while (ce) {
1475 ea_inode = ext4_iget(inode->i_sb, ce->e_value,
1476 EXT4_IGET_NORMAL);
1477 if (!IS_ERR(ea_inode) &&
1478 !is_bad_inode(ea_inode) &&
1479 (EXT4_I(ea_inode)->i_flags & EXT4_EA_INODE_FL) &&
1480 i_size_read(ea_inode) == value_len &&
1481 !ext4_xattr_inode_read(ea_inode, ea_data, value_len) &&
1482 !ext4_xattr_inode_verify_hashes(ea_inode, NULL, ea_data,
1483 value_len) &&
1484 !memcmp(value, ea_data, value_len)) {
1485 mb_cache_entry_touch(ea_inode_cache, ce);
1486 mb_cache_entry_put(ea_inode_cache, ce);
1487 kvfree(ea_data);
1488 return ea_inode;
1489 }
1490
1491 if (!IS_ERR(ea_inode))
1492 iput(ea_inode);
1493 ce = mb_cache_entry_find_next(ea_inode_cache, ce);
1494 }
1495 kvfree(ea_data);
1496 return NULL;
1497 }
1498
1499 /*
1500 * Add value of the EA in an inode.
1501 */
1502 static int ext4_xattr_inode_lookup_create(handle_t *handle, struct inode *inode,
1503 const void *value, size_t value_len,
1504 struct inode **ret_inode)
1505 {
1506 struct inode *ea_inode;
1507 u32 hash;
1508 int err;
1509
1510 hash = ext4_xattr_inode_hash(EXT4_SB(inode->i_sb), value, value_len);
1511 ea_inode = ext4_xattr_inode_cache_find(inode, value, value_len, hash);
1512 if (ea_inode) {
1513 err = ext4_xattr_inode_inc_ref(handle, ea_inode);
1514 if (err) {
1515 iput(ea_inode);
1516 return err;
1517 }
1518
1519 *ret_inode = ea_inode;
1520 return 0;
1521 }
1522
1523 /* Create an inode for the EA value */
1524 ea_inode = ext4_xattr_inode_create(handle, inode, hash);
1525 if (IS_ERR(ea_inode))
1526 return PTR_ERR(ea_inode);
1527
1528 err = ext4_xattr_inode_write(handle, ea_inode, value, value_len);
1529 if (err) {
1530 ext4_xattr_inode_dec_ref(handle, ea_inode);
1531 iput(ea_inode);
1532 return err;
1533 }
1534
1535 if (EA_INODE_CACHE(inode))
1536 mb_cache_entry_create(EA_INODE_CACHE(inode), GFP_NOFS, hash,
1537 ea_inode->i_ino, true /* reusable */);
1538
1539 *ret_inode = ea_inode;
1540 return 0;
1541 }
1542
1543 /*
1544 * Reserve min(block_size/8, 1024) bytes for xattr entries/names if ea_inode
1545 * feature is enabled.
1546 */
1547 #define EXT4_XATTR_BLOCK_RESERVE(inode) min(i_blocksize(inode)/8, 1024U)
1548
1549 static int ext4_xattr_set_entry(struct ext4_xattr_info *i,
1550 struct ext4_xattr_search *s,
1551 handle_t *handle, struct inode *inode,
1552 bool is_block)
1553 {
1554 struct ext4_xattr_entry *last, *next;
1555 struct ext4_xattr_entry *here = s->here;
1556 size_t min_offs = s->end - s->base, name_len = strlen(i->name);
1557 int in_inode = i->in_inode;
1558 struct inode *old_ea_inode = NULL;
1559 struct inode *new_ea_inode = NULL;
1560 size_t old_size, new_size;
1561 int ret;
1562
1563 /* Space used by old and new values. */
1564 old_size = (!s->not_found && !here->e_value_inum) ?
1565 EXT4_XATTR_SIZE(le32_to_cpu(here->e_value_size)) : 0;
1566 new_size = (i->value && !in_inode) ? EXT4_XATTR_SIZE(i->value_len) : 0;
1567
1568 /*
1569 * Optimization for the simple case when old and new values have the
1570 * same padded sizes. Not applicable if external inodes are involved.
1571 */
1572 if (new_size && new_size == old_size) {
1573 size_t offs = le16_to_cpu(here->e_value_offs);
1574 void *val = s->base + offs;
1575
1576 here->e_value_size = cpu_to_le32(i->value_len);
1577 if (i->value == EXT4_ZERO_XATTR_VALUE) {
1578 memset(val, 0, new_size);
1579 } else {
1580 memcpy(val, i->value, i->value_len);
1581 /* Clear padding bytes. */
1582 memset(val + i->value_len, 0, new_size - i->value_len);
1583 }
1584 goto update_hash;
1585 }
1586
1587 /* Compute min_offs and last. */
1588 last = s->first;
1589 for (; !IS_LAST_ENTRY(last); last = next) {
1590 next = EXT4_XATTR_NEXT(last);
1591 if ((void *)next >= s->end) {
1592 EXT4_ERROR_INODE(inode, "corrupted xattr entries");
1593 ret = -EFSCORRUPTED;
1594 goto out;
1595 }
1596 if (!last->e_value_inum && last->e_value_size) {
1597 size_t offs = le16_to_cpu(last->e_value_offs);
1598 if (offs < min_offs)
1599 min_offs = offs;
1600 }
1601 }
1602
1603 /* Check whether we have enough space. */
1604 if (i->value) {
1605 size_t free;
1606
1607 free = min_offs - ((void *)last - s->base) - sizeof(__u32);
1608 if (!s->not_found)
1609 free += EXT4_XATTR_LEN(name_len) + old_size;
1610
1611 if (free < EXT4_XATTR_LEN(name_len) + new_size) {
1612 ret = -ENOSPC;
1613 goto out;
1614 }
1615
1616 /*
1617 * If storing the value in an external inode is an option,
1618 * reserve space for xattr entries/names in the external
1619 * attribute block so that a long value does not occupy the
1620 * whole space and prevent further entries being added.
1621 */
1622 if (ext4_has_feature_ea_inode(inode->i_sb) &&
1623 new_size && is_block &&
1624 (min_offs + old_size - new_size) <
1625 EXT4_XATTR_BLOCK_RESERVE(inode)) {
1626 ret = -ENOSPC;
1627 goto out;
1628 }
1629 }
1630
1631 /*
1632 * Getting access to old and new ea inodes is subject to failures.
1633 * Finish that work before doing any modifications to the xattr data.
1634 */
1635 if (!s->not_found && here->e_value_inum) {
1636 ret = ext4_xattr_inode_iget(inode,
1637 le32_to_cpu(here->e_value_inum),
1638 le32_to_cpu(here->e_hash),
1639 &old_ea_inode);
1640 if (ret) {
1641 old_ea_inode = NULL;
1642 goto out;
1643 }
1644 }
1645 if (i->value && in_inode) {
1646 WARN_ON_ONCE(!i->value_len);
1647
1648 ret = ext4_xattr_inode_alloc_quota(inode, i->value_len);
1649 if (ret)
1650 goto out;
1651
1652 ret = ext4_xattr_inode_lookup_create(handle, inode, i->value,
1653 i->value_len,
1654 &new_ea_inode);
1655 if (ret) {
1656 new_ea_inode = NULL;
1657 ext4_xattr_inode_free_quota(inode, NULL, i->value_len);
1658 goto out;
1659 }
1660 }
1661
1662 if (old_ea_inode) {
1663 /* We are ready to release ref count on the old_ea_inode. */
1664 ret = ext4_xattr_inode_dec_ref(handle, old_ea_inode);
1665 if (ret) {
1666 /* Release newly required ref count on new_ea_inode. */
1667 if (new_ea_inode) {
1668 int err;
1669
1670 err = ext4_xattr_inode_dec_ref(handle,
1671 new_ea_inode);
1672 if (err)
1673 ext4_warning_inode(new_ea_inode,
1674 "dec ref new_ea_inode err=%d",
1675 err);
1676 ext4_xattr_inode_free_quota(inode, new_ea_inode,
1677 i->value_len);
1678 }
1679 goto out;
1680 }
1681
1682 ext4_xattr_inode_free_quota(inode, old_ea_inode,
1683 le32_to_cpu(here->e_value_size));
1684 }
1685
1686 /* No failures allowed past this point. */
1687
1688 if (!s->not_found && here->e_value_size && !here->e_value_inum) {
1689 /* Remove the old value. */
1690 void *first_val = s->base + min_offs;
1691 size_t offs = le16_to_cpu(here->e_value_offs);
1692 void *val = s->base + offs;
1693
1694 memmove(first_val + old_size, first_val, val - first_val);
1695 memset(first_val, 0, old_size);
1696 min_offs += old_size;
1697
1698 /* Adjust all value offsets. */
1699 last = s->first;
1700 while (!IS_LAST_ENTRY(last)) {
1701 size_t o = le16_to_cpu(last->e_value_offs);
1702
1703 if (!last->e_value_inum &&
1704 last->e_value_size && o < offs)
1705 last->e_value_offs = cpu_to_le16(o + old_size);
1706 last = EXT4_XATTR_NEXT(last);
1707 }
1708 }
1709
1710 if (!i->value) {
1711 /* Remove old name. */
1712 size_t size = EXT4_XATTR_LEN(name_len);
1713
1714 last = ENTRY((void *)last - size);
1715 memmove(here, (void *)here + size,
1716 (void *)last - (void *)here + sizeof(__u32));
1717 memset(last, 0, size);
1718 } else if (s->not_found) {
1719 /* Insert new name. */
1720 size_t size = EXT4_XATTR_LEN(name_len);
1721 size_t rest = (void *)last - (void *)here + sizeof(__u32);
1722
1723 memmove((void *)here + size, here, rest);
1724 memset(here, 0, size);
1725 here->e_name_index = i->name_index;
1726 here->e_name_len = name_len;
1727 memcpy(here->e_name, i->name, name_len);
1728 } else {
1729 /* This is an update, reset value info. */
1730 here->e_value_inum = 0;
1731 here->e_value_offs = 0;
1732 here->e_value_size = 0;
1733 }
1734
1735 if (i->value) {
1736 /* Insert new value. */
1737 if (in_inode) {
1738 here->e_value_inum = cpu_to_le32(new_ea_inode->i_ino);
1739 } else if (i->value_len) {
1740 void *val = s->base + min_offs - new_size;
1741
1742 here->e_value_offs = cpu_to_le16(min_offs - new_size);
1743 if (i->value == EXT4_ZERO_XATTR_VALUE) {
1744 memset(val, 0, new_size);
1745 } else {
1746 memcpy(val, i->value, i->value_len);
1747 /* Clear padding bytes. */
1748 memset(val + i->value_len, 0,
1749 new_size - i->value_len);
1750 }
1751 }
1752 here->e_value_size = cpu_to_le32(i->value_len);
1753 }
1754
1755 update_hash:
1756 if (i->value) {
1757 __le32 hash = 0;
1758
1759 /* Entry hash calculation. */
1760 if (in_inode) {
1761 __le32 crc32c_hash;
1762
1763 /*
1764 * Feed crc32c hash instead of the raw value for entry
1765 * hash calculation. This is to avoid walking
1766 * potentially long value buffer again.
1767 */
1768 crc32c_hash = cpu_to_le32(
1769 ext4_xattr_inode_get_hash(new_ea_inode));
1770 hash = ext4_xattr_hash_entry(here->e_name,
1771 here->e_name_len,
1772 &crc32c_hash, 1);
1773 } else if (is_block) {
1774 __le32 *value = s->base + le16_to_cpu(
1775 here->e_value_offs);
1776
1777 hash = ext4_xattr_hash_entry(here->e_name,
1778 here->e_name_len, value,
1779 new_size >> 2);
1780 }
1781 here->e_hash = hash;
1782 }
1783
1784 if (is_block)
1785 ext4_xattr_rehash((struct ext4_xattr_header *)s->base);
1786
1787 ret = 0;
1788 out:
1789 iput(old_ea_inode);
1790 iput(new_ea_inode);
1791 return ret;
1792 }
1793
1794 struct ext4_xattr_block_find {
1795 struct ext4_xattr_search s;
1796 struct buffer_head *bh;
1797 };
1798
1799 static int
1800 ext4_xattr_block_find(struct inode *inode, struct ext4_xattr_info *i,
1801 struct ext4_xattr_block_find *bs)
1802 {
1803 struct super_block *sb = inode->i_sb;
1804 int error;
1805
1806 ea_idebug(inode, "name=%d.%s, value=%p, value_len=%ld",
1807 i->name_index, i->name, i->value, (long)i->value_len);
1808
1809 if (EXT4_I(inode)->i_file_acl) {
1810 /* The inode already has an extended attribute block. */
1811 bs->bh = ext4_sb_bread(sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
1812 if (IS_ERR(bs->bh)) {
1813 error = PTR_ERR(bs->bh);
1814 bs->bh = NULL;
1815 return error;
1816 }
1817 ea_bdebug(bs->bh, "b_count=%d, refcount=%d",
1818 atomic_read(&(bs->bh->b_count)),
1819 le32_to_cpu(BHDR(bs->bh)->h_refcount));
1820 error = ext4_xattr_check_block(inode, bs->bh);
1821 if (error)
1822 return error;
1823 /* Find the named attribute. */
1824 bs->s.base = BHDR(bs->bh);
1825 bs->s.first = BFIRST(bs->bh);
1826 bs->s.end = bs->bh->b_data + bs->bh->b_size;
1827 bs->s.here = bs->s.first;
1828 error = xattr_find_entry(inode, &bs->s.here, bs->s.end,
1829 i->name_index, i->name, 1);
1830 if (error && error != -ENODATA)
1831 return error;
1832 bs->s.not_found = error;
1833 }
1834 return 0;
1835 }
1836
1837 static int
1838 ext4_xattr_block_set(handle_t *handle, struct inode *inode,
1839 struct ext4_xattr_info *i,
1840 struct ext4_xattr_block_find *bs)
1841 {
1842 struct super_block *sb = inode->i_sb;
1843 struct buffer_head *new_bh = NULL;
1844 struct ext4_xattr_search s_copy = bs->s;
1845 struct ext4_xattr_search *s = &s_copy;
1846 struct mb_cache_entry *ce = NULL;
1847 int error = 0;
1848 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
1849 struct inode *ea_inode = NULL, *tmp_inode;
1850 size_t old_ea_inode_quota = 0;
1851 unsigned int ea_ino;
1852
1853
1854 #define header(x) ((struct ext4_xattr_header *)(x))
1855
1856 if (s->base) {
1857 BUFFER_TRACE(bs->bh, "get_write_access");
1858 error = ext4_journal_get_write_access(handle, bs->bh);
1859 if (error)
1860 goto cleanup;
1861 lock_buffer(bs->bh);
1862
1863 if (header(s->base)->h_refcount == cpu_to_le32(1)) {
1864 __u32 hash = le32_to_cpu(BHDR(bs->bh)->h_hash);
1865
1866 /*
1867 * This must happen under buffer lock for
1868 * ext4_xattr_block_set() to reliably detect modified
1869 * block
1870 */
1871 if (ea_block_cache)
1872 mb_cache_entry_delete(ea_block_cache, hash,
1873 bs->bh->b_blocknr);
1874 ea_bdebug(bs->bh, "modifying in-place");
1875 error = ext4_xattr_set_entry(i, s, handle, inode,
1876 true /* is_block */);
1877 ext4_xattr_block_csum_set(inode, bs->bh);
1878 unlock_buffer(bs->bh);
1879 if (error == -EFSCORRUPTED)
1880 goto bad_block;
1881 if (!error)
1882 error = ext4_handle_dirty_metadata(handle,
1883 inode,
1884 bs->bh);
1885 if (error)
1886 goto cleanup;
1887 goto inserted;
1888 } else {
1889 int offset = (char *)s->here - bs->bh->b_data;
1890
1891 unlock_buffer(bs->bh);
1892 ea_bdebug(bs->bh, "cloning");
1893 s->base = kmalloc(bs->bh->b_size, GFP_NOFS);
1894 error = -ENOMEM;
1895 if (s->base == NULL)
1896 goto cleanup;
1897 memcpy(s->base, BHDR(bs->bh), bs->bh->b_size);
1898 s->first = ENTRY(header(s->base)+1);
1899 header(s->base)->h_refcount = cpu_to_le32(1);
1900 s->here = ENTRY(s->base + offset);
1901 s->end = s->base + bs->bh->b_size;
1902
1903 /*
1904 * If existing entry points to an xattr inode, we need
1905 * to prevent ext4_xattr_set_entry() from decrementing
1906 * ref count on it because the reference belongs to the
1907 * original block. In this case, make the entry look
1908 * like it has an empty value.
1909 */
1910 if (!s->not_found && s->here->e_value_inum) {
1911 ea_ino = le32_to_cpu(s->here->e_value_inum);
1912 error = ext4_xattr_inode_iget(inode, ea_ino,
1913 le32_to_cpu(s->here->e_hash),
1914 &tmp_inode);
1915 if (error)
1916 goto cleanup;
1917
1918 if (!ext4_test_inode_state(tmp_inode,
1919 EXT4_STATE_LUSTRE_EA_INODE)) {
1920 /*
1921 * Defer quota free call for previous
1922 * inode until success is guaranteed.
1923 */
1924 old_ea_inode_quota = le32_to_cpu(
1925 s->here->e_value_size);
1926 }
1927 iput(tmp_inode);
1928
1929 s->here->e_value_inum = 0;
1930 s->here->e_value_size = 0;
1931 }
1932 }
1933 } else {
1934 /* Allocate a buffer where we construct the new block. */
1935 s->base = kzalloc(sb->s_blocksize, GFP_NOFS);
1936 error = -ENOMEM;
1937 if (s->base == NULL)
1938 goto cleanup;
1939 header(s->base)->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
1940 header(s->base)->h_blocks = cpu_to_le32(1);
1941 header(s->base)->h_refcount = cpu_to_le32(1);
1942 s->first = ENTRY(header(s->base)+1);
1943 s->here = ENTRY(header(s->base)+1);
1944 s->end = s->base + sb->s_blocksize;
1945 }
1946
1947 error = ext4_xattr_set_entry(i, s, handle, inode, true /* is_block */);
1948 if (error == -EFSCORRUPTED)
1949 goto bad_block;
1950 if (error)
1951 goto cleanup;
1952
1953 if (i->value && s->here->e_value_inum) {
1954 /*
1955 * A ref count on ea_inode has been taken as part of the call to
1956 * ext4_xattr_set_entry() above. We would like to drop this
1957 * extra ref but we have to wait until the xattr block is
1958 * initialized and has its own ref count on the ea_inode.
1959 */
1960 ea_ino = le32_to_cpu(s->here->e_value_inum);
1961 error = ext4_xattr_inode_iget(inode, ea_ino,
1962 le32_to_cpu(s->here->e_hash),
1963 &ea_inode);
1964 if (error) {
1965 ea_inode = NULL;
1966 goto cleanup;
1967 }
1968 }
1969
1970 inserted:
1971 if (!IS_LAST_ENTRY(s->first)) {
1972 new_bh = ext4_xattr_block_cache_find(inode, header(s->base),
1973 &ce);
1974 if (new_bh) {
1975 /* We found an identical block in the cache. */
1976 if (new_bh == bs->bh)
1977 ea_bdebug(new_bh, "keeping");
1978 else {
1979 u32 ref;
1980
1981 WARN_ON_ONCE(dquot_initialize_needed(inode));
1982
1983 /* The old block is released after updating
1984 the inode. */
1985 error = dquot_alloc_block(inode,
1986 EXT4_C2B(EXT4_SB(sb), 1));
1987 if (error)
1988 goto cleanup;
1989 BUFFER_TRACE(new_bh, "get_write_access");
1990 error = ext4_journal_get_write_access(handle,
1991 new_bh);
1992 if (error)
1993 goto cleanup_dquot;
1994 lock_buffer(new_bh);
1995 /*
1996 * We have to be careful about races with
1997 * freeing, rehashing or adding references to
1998 * xattr block. Once we hold buffer lock xattr
1999 * block's state is stable so we can check
2000 * whether the block got freed / rehashed or
2001 * not. Since we unhash mbcache entry under
2002 * buffer lock when freeing / rehashing xattr
2003 * block, checking whether entry is still
2004 * hashed is reliable. Same rules hold for
2005 * e_reusable handling.
2006 */
2007 if (hlist_bl_unhashed(&ce->e_hash_list) ||
2008 !ce->e_reusable) {
2009 /*
2010 * Undo everything and check mbcache
2011 * again.
2012 */
2013 unlock_buffer(new_bh);
2014 dquot_free_block(inode,
2015 EXT4_C2B(EXT4_SB(sb),
2016 1));
2017 brelse(new_bh);
2018 mb_cache_entry_put(ea_block_cache, ce);
2019 ce = NULL;
2020 new_bh = NULL;
2021 goto inserted;
2022 }
2023 ref = le32_to_cpu(BHDR(new_bh)->h_refcount) + 1;
2024 BHDR(new_bh)->h_refcount = cpu_to_le32(ref);
2025 if (ref >= EXT4_XATTR_REFCOUNT_MAX)
2026 ce->e_reusable = 0;
2027 ea_bdebug(new_bh, "reusing; refcount now=%d",
2028 ref);
2029 ext4_xattr_block_csum_set(inode, new_bh);
2030 unlock_buffer(new_bh);
2031 error = ext4_handle_dirty_metadata(handle,
2032 inode,
2033 new_bh);
2034 if (error)
2035 goto cleanup_dquot;
2036 }
2037 mb_cache_entry_touch(ea_block_cache, ce);
2038 mb_cache_entry_put(ea_block_cache, ce);
2039 ce = NULL;
2040 } else if (bs->bh && s->base == bs->bh->b_data) {
2041 /* We were modifying this block in-place. */
2042 ea_bdebug(bs->bh, "keeping this block");
2043 ext4_xattr_block_cache_insert(ea_block_cache, bs->bh);
2044 new_bh = bs->bh;
2045 get_bh(new_bh);
2046 } else {
2047 /* We need to allocate a new block */
2048 ext4_fsblk_t goal, block;
2049
2050 WARN_ON_ONCE(dquot_initialize_needed(inode));
2051
2052 goal = ext4_group_first_block_no(sb,
2053 EXT4_I(inode)->i_block_group);
2054
2055 /* non-extent files can't have physical blocks past 2^32 */
2056 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
2057 goal = goal & EXT4_MAX_BLOCK_FILE_PHYS;
2058
2059 block = ext4_new_meta_blocks(handle, inode, goal, 0,
2060 NULL, &error);
2061 if (error)
2062 goto cleanup;
2063
2064 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
2065 BUG_ON(block > EXT4_MAX_BLOCK_FILE_PHYS);
2066
2067 ea_idebug(inode, "creating block %llu",
2068 (unsigned long long)block);
2069
2070 new_bh = sb_getblk(sb, block);
2071 if (unlikely(!new_bh)) {
2072 error = -ENOMEM;
2073 getblk_failed:
2074 ext4_free_blocks(handle, inode, NULL, block, 1,
2075 EXT4_FREE_BLOCKS_METADATA);
2076 goto cleanup;
2077 }
2078 error = ext4_xattr_inode_inc_ref_all(handle, inode,
2079 ENTRY(header(s->base)+1));
2080 if (error)
2081 goto getblk_failed;
2082 if (ea_inode) {
2083 /* Drop the extra ref on ea_inode. */
2084 error = ext4_xattr_inode_dec_ref(handle,
2085 ea_inode);
2086 if (error)
2087 ext4_warning_inode(ea_inode,
2088 "dec ref error=%d",
2089 error);
2090 iput(ea_inode);
2091 ea_inode = NULL;
2092 }
2093
2094 lock_buffer(new_bh);
2095 error = ext4_journal_get_create_access(handle, new_bh);
2096 if (error) {
2097 unlock_buffer(new_bh);
2098 error = -EIO;
2099 goto getblk_failed;
2100 }
2101 memcpy(new_bh->b_data, s->base, new_bh->b_size);
2102 ext4_xattr_block_csum_set(inode, new_bh);
2103 set_buffer_uptodate(new_bh);
2104 unlock_buffer(new_bh);
2105 ext4_xattr_block_cache_insert(ea_block_cache, new_bh);
2106 error = ext4_handle_dirty_metadata(handle, inode,
2107 new_bh);
2108 if (error)
2109 goto cleanup;
2110 }
2111 }
2112
2113 if (old_ea_inode_quota)
2114 ext4_xattr_inode_free_quota(inode, NULL, old_ea_inode_quota);
2115
2116 /* Update the inode. */
2117 EXT4_I(inode)->i_file_acl = new_bh ? new_bh->b_blocknr : 0;
2118
2119 /* Drop the previous xattr block. */
2120 if (bs->bh && bs->bh != new_bh) {
2121 struct ext4_xattr_inode_array *ea_inode_array = NULL;
2122
2123 ext4_xattr_release_block(handle, inode, bs->bh,
2124 &ea_inode_array,
2125 0 /* extra_credits */);
2126 ext4_xattr_inode_array_free(ea_inode_array);
2127 }
2128 error = 0;
2129
2130 cleanup:
2131 if (ea_inode) {
2132 int error2;
2133
2134 error2 = ext4_xattr_inode_dec_ref(handle, ea_inode);
2135 if (error2)
2136 ext4_warning_inode(ea_inode, "dec ref error=%d",
2137 error2);
2138
2139 /* If there was an error, revert the quota charge. */
2140 if (error)
2141 ext4_xattr_inode_free_quota(inode, ea_inode,
2142 i_size_read(ea_inode));
2143 iput(ea_inode);
2144 }
2145 if (ce)
2146 mb_cache_entry_put(ea_block_cache, ce);
2147 brelse(new_bh);
2148 if (!(bs->bh && s->base == bs->bh->b_data))
2149 kfree(s->base);
2150
2151 return error;
2152
2153 cleanup_dquot:
2154 dquot_free_block(inode, EXT4_C2B(EXT4_SB(sb), 1));
2155 goto cleanup;
2156
2157 bad_block:
2158 EXT4_ERROR_INODE(inode, "bad block %llu",
2159 EXT4_I(inode)->i_file_acl);
2160 goto cleanup;
2161
2162 #undef header
2163 }
2164
2165 int ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i,
2166 struct ext4_xattr_ibody_find *is)
2167 {
2168 struct ext4_xattr_ibody_header *header;
2169 struct ext4_inode *raw_inode;
2170 int error;
2171
2172 if (EXT4_I(inode)->i_extra_isize == 0)
2173 return 0;
2174 raw_inode = ext4_raw_inode(&is->iloc);
2175 header = IHDR(inode, raw_inode);
2176 is->s.base = is->s.first = IFIRST(header);
2177 is->s.here = is->s.first;
2178 is->s.end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
2179 if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
2180 error = xattr_check_inode(inode, header, is->s.end);
2181 if (error)
2182 return error;
2183 /* Find the named attribute. */
2184 error = xattr_find_entry(inode, &is->s.here, is->s.end,
2185 i->name_index, i->name, 0);
2186 if (error && error != -ENODATA)
2187 return error;
2188 is->s.not_found = error;
2189 }
2190 return 0;
2191 }
2192
2193 int ext4_xattr_ibody_inline_set(handle_t *handle, struct inode *inode,
2194 struct ext4_xattr_info *i,
2195 struct ext4_xattr_ibody_find *is)
2196 {
2197 struct ext4_xattr_ibody_header *header;
2198 struct ext4_xattr_search *s = &is->s;
2199 int error;
2200
2201 if (EXT4_I(inode)->i_extra_isize == 0)
2202 return -ENOSPC;
2203 error = ext4_xattr_set_entry(i, s, handle, inode, false /* is_block */);
2204 if (error)
2205 return error;
2206 header = IHDR(inode, ext4_raw_inode(&is->iloc));
2207 if (!IS_LAST_ENTRY(s->first)) {
2208 header->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
2209 ext4_set_inode_state(inode, EXT4_STATE_XATTR);
2210 } else {
2211 header->h_magic = cpu_to_le32(0);
2212 ext4_clear_inode_state(inode, EXT4_STATE_XATTR);
2213 }
2214 return 0;
2215 }
2216
2217 static int ext4_xattr_ibody_set(handle_t *handle, struct inode *inode,
2218 struct ext4_xattr_info *i,
2219 struct ext4_xattr_ibody_find *is)
2220 {
2221 struct ext4_xattr_ibody_header *header;
2222 struct ext4_xattr_search *s = &is->s;
2223 int error;
2224
2225 if (EXT4_I(inode)->i_extra_isize == 0)
2226 return -ENOSPC;
2227 error = ext4_xattr_set_entry(i, s, handle, inode, false /* is_block */);
2228 if (error)
2229 return error;
2230 header = IHDR(inode, ext4_raw_inode(&is->iloc));
2231 if (!IS_LAST_ENTRY(s->first)) {
2232 header->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
2233 ext4_set_inode_state(inode, EXT4_STATE_XATTR);
2234 } else {
2235 header->h_magic = cpu_to_le32(0);
2236 ext4_clear_inode_state(inode, EXT4_STATE_XATTR);
2237 }
2238 return 0;
2239 }
2240
2241 static int ext4_xattr_value_same(struct ext4_xattr_search *s,
2242 struct ext4_xattr_info *i)
2243 {
2244 void *value;
2245
2246 /* When e_value_inum is set the value is stored externally. */
2247 if (s->here->e_value_inum)
2248 return 0;
2249 if (le32_to_cpu(s->here->e_value_size) != i->value_len)
2250 return 0;
2251 value = ((void *)s->base) + le16_to_cpu(s->here->e_value_offs);
2252 return !memcmp(value, i->value, i->value_len);
2253 }
2254
2255 static struct buffer_head *ext4_xattr_get_block(struct inode *inode)
2256 {
2257 struct buffer_head *bh;
2258 int error;
2259
2260 if (!EXT4_I(inode)->i_file_acl)
2261 return NULL;
2262 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
2263 if (IS_ERR(bh))
2264 return bh;
2265 error = ext4_xattr_check_block(inode, bh);
2266 if (error) {
2267 brelse(bh);
2268 return ERR_PTR(error);
2269 }
2270 return bh;
2271 }
2272
2273 /*
2274 * ext4_xattr_set_handle()
2275 *
2276 * Create, replace or remove an extended attribute for this inode. Value
2277 * is NULL to remove an existing extended attribute, and non-NULL to
2278 * either replace an existing extended attribute, or create a new extended
2279 * attribute. The flags XATTR_REPLACE and XATTR_CREATE
2280 * specify that an extended attribute must exist and must not exist
2281 * previous to the call, respectively.
2282 *
2283 * Returns 0, or a negative error number on failure.
2284 */
2285 int
2286 ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
2287 const char *name, const void *value, size_t value_len,
2288 int flags)
2289 {
2290 struct ext4_xattr_info i = {
2291 .name_index = name_index,
2292 .name = name,
2293 .value = value,
2294 .value_len = value_len,
2295 .in_inode = 0,
2296 };
2297 struct ext4_xattr_ibody_find is = {
2298 .s = { .not_found = -ENODATA, },
2299 };
2300 struct ext4_xattr_block_find bs = {
2301 .s = { .not_found = -ENODATA, },
2302 };
2303 int no_expand;
2304 int error;
2305
2306 if (!name)
2307 return -EINVAL;
2308 if (strlen(name) > 255)
2309 return -ERANGE;
2310
2311 ext4_write_lock_xattr(inode, &no_expand);
2312
2313 /* Check journal credits under write lock. */
2314 if (ext4_handle_valid(handle)) {
2315 struct buffer_head *bh;
2316 int credits;
2317
2318 bh = ext4_xattr_get_block(inode);
2319 if (IS_ERR(bh)) {
2320 error = PTR_ERR(bh);
2321 goto cleanup;
2322 }
2323
2324 credits = __ext4_xattr_set_credits(inode->i_sb, inode, bh,
2325 value_len,
2326 flags & XATTR_CREATE);
2327 brelse(bh);
2328
2329 if (jbd2_handle_buffer_credits(handle) < credits) {
2330 error = -ENOSPC;
2331 goto cleanup;
2332 }
2333 WARN_ON_ONCE(!(current->flags & PF_MEMALLOC_NOFS));
2334 }
2335
2336 error = ext4_reserve_inode_write(handle, inode, &is.iloc);
2337 if (error)
2338 goto cleanup;
2339
2340 if (ext4_test_inode_state(inode, EXT4_STATE_NEW)) {
2341 struct ext4_inode *raw_inode = ext4_raw_inode(&is.iloc);
2342 memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size);
2343 ext4_clear_inode_state(inode, EXT4_STATE_NEW);
2344 }
2345
2346 error = ext4_xattr_ibody_find(inode, &i, &is);
2347 if (error)
2348 goto cleanup;
2349 if (is.s.not_found)
2350 error = ext4_xattr_block_find(inode, &i, &bs);
2351 if (error)
2352 goto cleanup;
2353 if (is.s.not_found && bs.s.not_found) {
2354 error = -ENODATA;
2355 if (flags & XATTR_REPLACE)
2356 goto cleanup;
2357 error = 0;
2358 if (!value)
2359 goto cleanup;
2360 } else {
2361 error = -EEXIST;
2362 if (flags & XATTR_CREATE)
2363 goto cleanup;
2364 }
2365
2366 if (!value) {
2367 if (!is.s.not_found)
2368 error = ext4_xattr_ibody_set(handle, inode, &i, &is);
2369 else if (!bs.s.not_found)
2370 error = ext4_xattr_block_set(handle, inode, &i, &bs);
2371 } else {
2372 error = 0;
2373 /* Xattr value did not change? Save us some work and bail out */
2374 if (!is.s.not_found && ext4_xattr_value_same(&is.s, &i))
2375 goto cleanup;
2376 if (!bs.s.not_found && ext4_xattr_value_same(&bs.s, &i))
2377 goto cleanup;
2378
2379 if (ext4_has_feature_ea_inode(inode->i_sb) &&
2380 (EXT4_XATTR_SIZE(i.value_len) >
2381 EXT4_XATTR_MIN_LARGE_EA_SIZE(inode->i_sb->s_blocksize)))
2382 i.in_inode = 1;
2383 retry_inode:
2384 error = ext4_xattr_ibody_set(handle, inode, &i, &is);
2385 if (!error && !bs.s.not_found) {
2386 i.value = NULL;
2387 error = ext4_xattr_block_set(handle, inode, &i, &bs);
2388 } else if (error == -ENOSPC) {
2389 if (EXT4_I(inode)->i_file_acl && !bs.s.base) {
2390 brelse(bs.bh);
2391 bs.bh = NULL;
2392 error = ext4_xattr_block_find(inode, &i, &bs);
2393 if (error)
2394 goto cleanup;
2395 }
2396 error = ext4_xattr_block_set(handle, inode, &i, &bs);
2397 if (!error && !is.s.not_found) {
2398 i.value = NULL;
2399 error = ext4_xattr_ibody_set(handle, inode, &i,
2400 &is);
2401 } else if (error == -ENOSPC) {
2402 /*
2403 * Xattr does not fit in the block, store at
2404 * external inode if possible.
2405 */
2406 if (ext4_has_feature_ea_inode(inode->i_sb) &&
2407 i.value_len && !i.in_inode) {
2408 i.in_inode = 1;
2409 goto retry_inode;
2410 }
2411 }
2412 }
2413 }
2414 if (!error) {
2415 ext4_xattr_update_super_block(handle, inode->i_sb);
2416 inode->i_ctime = current_time(inode);
2417 if (!value)
2418 no_expand = 0;
2419 error = ext4_mark_iloc_dirty(handle, inode, &is.iloc);
2420 /*
2421 * The bh is consumed by ext4_mark_iloc_dirty, even with
2422 * error != 0.
2423 */
2424 is.iloc.bh = NULL;
2425 if (IS_SYNC(inode))
2426 ext4_handle_sync(handle);
2427 }
2428 ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_XATTR);
2429
2430 cleanup:
2431 brelse(is.iloc.bh);
2432 brelse(bs.bh);
2433 ext4_write_unlock_xattr(inode, &no_expand);
2434 return error;
2435 }
2436
2437 int ext4_xattr_set_credits(struct inode *inode, size_t value_len,
2438 bool is_create, int *credits)
2439 {
2440 struct buffer_head *bh;
2441 int err;
2442
2443 *credits = 0;
2444
2445 if (!EXT4_SB(inode->i_sb)->s_journal)
2446 return 0;
2447
2448 down_read(&EXT4_I(inode)->xattr_sem);
2449
2450 bh = ext4_xattr_get_block(inode);
2451 if (IS_ERR(bh)) {
2452 err = PTR_ERR(bh);
2453 } else {
2454 *credits = __ext4_xattr_set_credits(inode->i_sb, inode, bh,
2455 value_len, is_create);
2456 brelse(bh);
2457 err = 0;
2458 }
2459
2460 up_read(&EXT4_I(inode)->xattr_sem);
2461 return err;
2462 }
2463
2464 /*
2465 * ext4_xattr_set()
2466 *
2467 * Like ext4_xattr_set_handle, but start from an inode. This extended
2468 * attribute modification is a filesystem transaction by itself.
2469 *
2470 * Returns 0, or a negative error number on failure.
2471 */
2472 int
2473 ext4_xattr_set(struct inode *inode, int name_index, const char *name,
2474 const void *value, size_t value_len, int flags)
2475 {
2476 handle_t *handle;
2477 struct super_block *sb = inode->i_sb;
2478 int error, retries = 0;
2479 int credits;
2480
2481 error = dquot_initialize(inode);
2482 if (error)
2483 return error;
2484
2485 retry:
2486 error = ext4_xattr_set_credits(inode, value_len, flags & XATTR_CREATE,
2487 &credits);
2488 if (error)
2489 return error;
2490
2491 handle = ext4_journal_start(inode, EXT4_HT_XATTR, credits);
2492 if (IS_ERR(handle)) {
2493 error = PTR_ERR(handle);
2494 } else {
2495 int error2;
2496
2497 error = ext4_xattr_set_handle(handle, inode, name_index, name,
2498 value, value_len, flags);
2499 error2 = ext4_journal_stop(handle);
2500 if (error == -ENOSPC &&
2501 ext4_should_retry_alloc(sb, &retries))
2502 goto retry;
2503 if (error == 0)
2504 error = error2;
2505 }
2506 ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_XATTR);
2507
2508 return error;
2509 }
2510
2511 /*
2512 * Shift the EA entries in the inode to create space for the increased
2513 * i_extra_isize.
2514 */
2515 static void ext4_xattr_shift_entries(struct ext4_xattr_entry *entry,
2516 int value_offs_shift, void *to,
2517 void *from, size_t n)
2518 {
2519 struct ext4_xattr_entry *last = entry;
2520 int new_offs;
2521
2522 /* We always shift xattr headers further thus offsets get lower */
2523 BUG_ON(value_offs_shift > 0);
2524
2525 /* Adjust the value offsets of the entries */
2526 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
2527 if (!last->e_value_inum && last->e_value_size) {
2528 new_offs = le16_to_cpu(last->e_value_offs) +
2529 value_offs_shift;
2530 last->e_value_offs = cpu_to_le16(new_offs);
2531 }
2532 }
2533 /* Shift the entries by n bytes */
2534 memmove(to, from, n);
2535 }
2536
2537 /*
2538 * Move xattr pointed to by 'entry' from inode into external xattr block
2539 */
2540 static int ext4_xattr_move_to_block(handle_t *handle, struct inode *inode,
2541 struct ext4_inode *raw_inode,
2542 struct ext4_xattr_entry *entry)
2543 {
2544 struct ext4_xattr_ibody_find *is = NULL;
2545 struct ext4_xattr_block_find *bs = NULL;
2546 char *buffer = NULL, *b_entry_name = NULL;
2547 size_t value_size = le32_to_cpu(entry->e_value_size);
2548 struct ext4_xattr_info i = {
2549 .value = NULL,
2550 .value_len = 0,
2551 .name_index = entry->e_name_index,
2552 .in_inode = !!entry->e_value_inum,
2553 };
2554 struct ext4_xattr_ibody_header *header = IHDR(inode, raw_inode);
2555 int error;
2556
2557 is = kzalloc(sizeof(struct ext4_xattr_ibody_find), GFP_NOFS);
2558 bs = kzalloc(sizeof(struct ext4_xattr_block_find), GFP_NOFS);
2559 buffer = kmalloc(value_size, GFP_NOFS);
2560 b_entry_name = kmalloc(entry->e_name_len + 1, GFP_NOFS);
2561 if (!is || !bs || !buffer || !b_entry_name) {
2562 error = -ENOMEM;
2563 goto out;
2564 }
2565
2566 is->s.not_found = -ENODATA;
2567 bs->s.not_found = -ENODATA;
2568 is->iloc.bh = NULL;
2569 bs->bh = NULL;
2570
2571 /* Save the entry name and the entry value */
2572 if (entry->e_value_inum) {
2573 error = ext4_xattr_inode_get(inode, entry, buffer, value_size);
2574 if (error)
2575 goto out;
2576 } else {
2577 size_t value_offs = le16_to_cpu(entry->e_value_offs);
2578 memcpy(buffer, (void *)IFIRST(header) + value_offs, value_size);
2579 }
2580
2581 memcpy(b_entry_name, entry->e_name, entry->e_name_len);
2582 b_entry_name[entry->e_name_len] = '\0';
2583 i.name = b_entry_name;
2584
2585 error = ext4_get_inode_loc(inode, &is->iloc);
2586 if (error)
2587 goto out;
2588
2589 error = ext4_xattr_ibody_find(inode, &i, is);
2590 if (error)
2591 goto out;
2592
2593 /* Remove the chosen entry from the inode */
2594 error = ext4_xattr_ibody_set(handle, inode, &i, is);
2595 if (error)
2596 goto out;
2597
2598 i.value = buffer;
2599 i.value_len = value_size;
2600 error = ext4_xattr_block_find(inode, &i, bs);
2601 if (error)
2602 goto out;
2603
2604 /* Add entry which was removed from the inode into the block */
2605 error = ext4_xattr_block_set(handle, inode, &i, bs);
2606 if (error)
2607 goto out;
2608 error = 0;
2609 out:
2610 kfree(b_entry_name);
2611 kfree(buffer);
2612 if (is)
2613 brelse(is->iloc.bh);
2614 if (bs)
2615 brelse(bs->bh);
2616 kfree(is);
2617 kfree(bs);
2618
2619 return error;
2620 }
2621
2622 static int ext4_xattr_make_inode_space(handle_t *handle, struct inode *inode,
2623 struct ext4_inode *raw_inode,
2624 int isize_diff, size_t ifree,
2625 size_t bfree, int *total_ino)
2626 {
2627 struct ext4_xattr_ibody_header *header = IHDR(inode, raw_inode);
2628 struct ext4_xattr_entry *small_entry;
2629 struct ext4_xattr_entry *entry;
2630 struct ext4_xattr_entry *last;
2631 unsigned int entry_size; /* EA entry size */
2632 unsigned int total_size; /* EA entry size + value size */
2633 unsigned int min_total_size;
2634 int error;
2635
2636 while (isize_diff > ifree) {
2637 entry = NULL;
2638 small_entry = NULL;
2639 min_total_size = ~0U;
2640 last = IFIRST(header);
2641 /* Find the entry best suited to be pushed into EA block */
2642 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
2643 /* never move system.data out of the inode */
2644 if ((last->e_name_len == 4) &&
2645 (last->e_name_index == EXT4_XATTR_INDEX_SYSTEM) &&
2646 !memcmp(last->e_name, "data", 4))
2647 continue;
2648 total_size = EXT4_XATTR_LEN(last->e_name_len);
2649 if (!last->e_value_inum)
2650 total_size += EXT4_XATTR_SIZE(
2651 le32_to_cpu(last->e_value_size));
2652 if (total_size <= bfree &&
2653 total_size < min_total_size) {
2654 if (total_size + ifree < isize_diff) {
2655 small_entry = last;
2656 } else {
2657 entry = last;
2658 min_total_size = total_size;
2659 }
2660 }
2661 }
2662
2663 if (entry == NULL) {
2664 if (small_entry == NULL)
2665 return -ENOSPC;
2666 entry = small_entry;
2667 }
2668
2669 entry_size = EXT4_XATTR_LEN(entry->e_name_len);
2670 total_size = entry_size;
2671 if (!entry->e_value_inum)
2672 total_size += EXT4_XATTR_SIZE(
2673 le32_to_cpu(entry->e_value_size));
2674 error = ext4_xattr_move_to_block(handle, inode, raw_inode,
2675 entry);
2676 if (error)
2677 return error;
2678
2679 *total_ino -= entry_size;
2680 ifree += total_size;
2681 bfree -= total_size;
2682 }
2683
2684 return 0;
2685 }
2686
2687 /*
2688 * Expand an inode by new_extra_isize bytes when EAs are present.
2689 * Returns 0 on success or negative error number on failure.
2690 */
2691 int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
2692 struct ext4_inode *raw_inode, handle_t *handle)
2693 {
2694 struct ext4_xattr_ibody_header *header;
2695 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2696 static unsigned int mnt_count;
2697 size_t min_offs;
2698 size_t ifree, bfree;
2699 int total_ino;
2700 void *base, *end;
2701 int error = 0, tried_min_extra_isize = 0;
2702 int s_min_extra_isize = le16_to_cpu(sbi->s_es->s_min_extra_isize);
2703 int isize_diff; /* How much do we need to grow i_extra_isize */
2704
2705 retry:
2706 isize_diff = new_extra_isize - EXT4_I(inode)->i_extra_isize;
2707 if (EXT4_I(inode)->i_extra_isize >= new_extra_isize)
2708 return 0;
2709
2710 header = IHDR(inode, raw_inode);
2711
2712 /*
2713 * Check if enough free space is available in the inode to shift the
2714 * entries ahead by new_extra_isize.
2715 */
2716
2717 base = IFIRST(header);
2718 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
2719 min_offs = end - base;
2720 total_ino = sizeof(struct ext4_xattr_ibody_header) + sizeof(u32);
2721
2722 error = xattr_check_inode(inode, header, end);
2723 if (error)
2724 goto cleanup;
2725
2726 ifree = ext4_xattr_free_space(base, &min_offs, base, &total_ino);
2727 if (ifree >= isize_diff)
2728 goto shift;
2729
2730 /*
2731 * Enough free space isn't available in the inode, check if
2732 * EA block can hold new_extra_isize bytes.
2733 */
2734 if (EXT4_I(inode)->i_file_acl) {
2735 struct buffer_head *bh;
2736
2737 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
2738 if (IS_ERR(bh)) {
2739 error = PTR_ERR(bh);
2740 goto cleanup;
2741 }
2742 error = ext4_xattr_check_block(inode, bh);
2743 if (error) {
2744 brelse(bh);
2745 goto cleanup;
2746 }
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_journal_ensure_credits(handle, extra_credits,
2860 ext4_free_metadata_revoke_credits(inode->i_sb, 1));
2861 if (error < 0) {
2862 EXT4_ERROR_INODE(inode, "ensure credits (error %d)", error);
2863 goto cleanup;
2864 }
2865
2866 if (ext4_has_feature_ea_inode(inode->i_sb) &&
2867 ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
2868
2869 error = ext4_get_inode_loc(inode, &iloc);
2870 if (error) {
2871 EXT4_ERROR_INODE(inode, "inode loc (error %d)", error);
2872 goto cleanup;
2873 }
2874
2875 error = ext4_journal_get_write_access(handle, iloc.bh);
2876 if (error) {
2877 EXT4_ERROR_INODE(inode, "write access (error %d)",
2878 error);
2879 goto cleanup;
2880 }
2881
2882 header = IHDR(inode, ext4_raw_inode(&iloc));
2883 if (header->h_magic == cpu_to_le32(EXT4_XATTR_MAGIC))
2884 ext4_xattr_inode_dec_ref_all(handle, inode, iloc.bh,
2885 IFIRST(header),
2886 false /* block_csum */,
2887 ea_inode_array,
2888 extra_credits,
2889 false /* skip_quota */);
2890 }
2891
2892 if (EXT4_I(inode)->i_file_acl) {
2893 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
2894 if (IS_ERR(bh)) {
2895 error = PTR_ERR(bh);
2896 if (error == -EIO) {
2897 EXT4_ERROR_INODE_ERR(inode, EIO,
2898 "block %llu read error",
2899 EXT4_I(inode)->i_file_acl);
2900 }
2901 bh = NULL;
2902 goto cleanup;
2903 }
2904 error = ext4_xattr_check_block(inode, bh);
2905 if (error)
2906 goto cleanup;
2907
2908 if (ext4_has_feature_ea_inode(inode->i_sb)) {
2909 for (entry = BFIRST(bh); !IS_LAST_ENTRY(entry);
2910 entry = EXT4_XATTR_NEXT(entry)) {
2911 if (!entry->e_value_inum)
2912 continue;
2913 error = ext4_xattr_inode_iget(inode,
2914 le32_to_cpu(entry->e_value_inum),
2915 le32_to_cpu(entry->e_hash),
2916 &ea_inode);
2917 if (error)
2918 continue;
2919 ext4_xattr_inode_free_quota(inode, ea_inode,
2920 le32_to_cpu(entry->e_value_size));
2921 iput(ea_inode);
2922 }
2923
2924 }
2925
2926 ext4_xattr_release_block(handle, inode, bh, ea_inode_array,
2927 extra_credits);
2928 /*
2929 * Update i_file_acl value in the same transaction that releases
2930 * block.
2931 */
2932 EXT4_I(inode)->i_file_acl = 0;
2933 error = ext4_mark_inode_dirty(handle, inode);
2934 if (error) {
2935 EXT4_ERROR_INODE(inode, "mark inode dirty (error %d)",
2936 error);
2937 goto cleanup;
2938 }
2939 ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_XATTR);
2940 }
2941 error = 0;
2942 cleanup:
2943 brelse(iloc.bh);
2944 brelse(bh);
2945 return error;
2946 }
2947
2948 void ext4_xattr_inode_array_free(struct ext4_xattr_inode_array *ea_inode_array)
2949 {
2950 int idx;
2951
2952 if (ea_inode_array == NULL)
2953 return;
2954
2955 for (idx = 0; idx < ea_inode_array->count; ++idx)
2956 iput(ea_inode_array->inodes[idx]);
2957 kfree(ea_inode_array);
2958 }
2959
2960 /*
2961 * ext4_xattr_block_cache_insert()
2962 *
2963 * Create a new entry in the extended attribute block cache, and insert
2964 * it unless such an entry is already in the cache.
2965 *
2966 * Returns 0, or a negative error number on failure.
2967 */
2968 static void
2969 ext4_xattr_block_cache_insert(struct mb_cache *ea_block_cache,
2970 struct buffer_head *bh)
2971 {
2972 struct ext4_xattr_header *header = BHDR(bh);
2973 __u32 hash = le32_to_cpu(header->h_hash);
2974 int reusable = le32_to_cpu(header->h_refcount) <
2975 EXT4_XATTR_REFCOUNT_MAX;
2976 int error;
2977
2978 if (!ea_block_cache)
2979 return;
2980 error = mb_cache_entry_create(ea_block_cache, GFP_NOFS, hash,
2981 bh->b_blocknr, reusable);
2982 if (error) {
2983 if (error == -EBUSY)
2984 ea_bdebug(bh, "already in cache");
2985 } else
2986 ea_bdebug(bh, "inserting [%x]", (int)hash);
2987 }
2988
2989 /*
2990 * ext4_xattr_cmp()
2991 *
2992 * Compare two extended attribute blocks for equality.
2993 *
2994 * Returns 0 if the blocks are equal, 1 if they differ, and
2995 * a negative error number on errors.
2996 */
2997 static int
2998 ext4_xattr_cmp(struct ext4_xattr_header *header1,
2999 struct ext4_xattr_header *header2)
3000 {
3001 struct ext4_xattr_entry *entry1, *entry2;
3002
3003 entry1 = ENTRY(header1+1);
3004 entry2 = ENTRY(header2+1);
3005 while (!IS_LAST_ENTRY(entry1)) {
3006 if (IS_LAST_ENTRY(entry2))
3007 return 1;
3008 if (entry1->e_hash != entry2->e_hash ||
3009 entry1->e_name_index != entry2->e_name_index ||
3010 entry1->e_name_len != entry2->e_name_len ||
3011 entry1->e_value_size != entry2->e_value_size ||
3012 entry1->e_value_inum != entry2->e_value_inum ||
3013 memcmp(entry1->e_name, entry2->e_name, entry1->e_name_len))
3014 return 1;
3015 if (!entry1->e_value_inum &&
3016 memcmp((char *)header1 + le16_to_cpu(entry1->e_value_offs),
3017 (char *)header2 + le16_to_cpu(entry2->e_value_offs),
3018 le32_to_cpu(entry1->e_value_size)))
3019 return 1;
3020
3021 entry1 = EXT4_XATTR_NEXT(entry1);
3022 entry2 = EXT4_XATTR_NEXT(entry2);
3023 }
3024 if (!IS_LAST_ENTRY(entry2))
3025 return 1;
3026 return 0;
3027 }
3028
3029 /*
3030 * ext4_xattr_block_cache_find()
3031 *
3032 * Find an identical extended attribute block.
3033 *
3034 * Returns a pointer to the block found, or NULL if such a block was
3035 * not found or an error occurred.
3036 */
3037 static struct buffer_head *
3038 ext4_xattr_block_cache_find(struct inode *inode,
3039 struct ext4_xattr_header *header,
3040 struct mb_cache_entry **pce)
3041 {
3042 __u32 hash = le32_to_cpu(header->h_hash);
3043 struct mb_cache_entry *ce;
3044 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
3045
3046 if (!ea_block_cache)
3047 return NULL;
3048 if (!header->h_hash)
3049 return NULL; /* never share */
3050 ea_idebug(inode, "looking for cached blocks [%x]", (int)hash);
3051 ce = mb_cache_entry_find_first(ea_block_cache, hash);
3052 while (ce) {
3053 struct buffer_head *bh;
3054
3055 bh = ext4_sb_bread(inode->i_sb, ce->e_value, REQ_PRIO);
3056 if (IS_ERR(bh)) {
3057 if (PTR_ERR(bh) == -ENOMEM)
3058 return NULL;
3059 bh = NULL;
3060 EXT4_ERROR_INODE(inode, "block %lu read error",
3061 (unsigned long)ce->e_value);
3062 } else if (ext4_xattr_cmp(header, BHDR(bh)) == 0) {
3063 *pce = ce;
3064 return bh;
3065 }
3066 brelse(bh);
3067 ce = mb_cache_entry_find_next(ea_block_cache, ce);
3068 }
3069 return NULL;
3070 }
3071
3072 #define NAME_HASH_SHIFT 5
3073 #define VALUE_HASH_SHIFT 16
3074
3075 /*
3076 * ext4_xattr_hash_entry()
3077 *
3078 * Compute the hash of an extended attribute.
3079 */
3080 static __le32 ext4_xattr_hash_entry(char *name, size_t name_len, __le32 *value,
3081 size_t value_count)
3082 {
3083 __u32 hash = 0;
3084
3085 while (name_len--) {
3086 hash = (hash << NAME_HASH_SHIFT) ^
3087 (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^
3088 *name++;
3089 }
3090 while (value_count--) {
3091 hash = (hash << VALUE_HASH_SHIFT) ^
3092 (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^
3093 le32_to_cpu(*value++);
3094 }
3095 return cpu_to_le32(hash);
3096 }
3097
3098 #undef NAME_HASH_SHIFT
3099 #undef VALUE_HASH_SHIFT
3100
3101 #define BLOCK_HASH_SHIFT 16
3102
3103 /*
3104 * ext4_xattr_rehash()
3105 *
3106 * Re-compute the extended attribute hash value after an entry has changed.
3107 */
3108 static void ext4_xattr_rehash(struct ext4_xattr_header *header)
3109 {
3110 struct ext4_xattr_entry *here;
3111 __u32 hash = 0;
3112
3113 here = ENTRY(header+1);
3114 while (!IS_LAST_ENTRY(here)) {
3115 if (!here->e_hash) {
3116 /* Block is not shared if an entry's hash value == 0 */
3117 hash = 0;
3118 break;
3119 }
3120 hash = (hash << BLOCK_HASH_SHIFT) ^
3121 (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^
3122 le32_to_cpu(here->e_hash);
3123 here = EXT4_XATTR_NEXT(here);
3124 }
3125 header->h_hash = cpu_to_le32(hash);
3126 }
3127
3128 #undef BLOCK_HASH_SHIFT
3129
3130 #define HASH_BUCKET_BITS 10
3131
3132 struct mb_cache *
3133 ext4_xattr_create_cache(void)
3134 {
3135 return mb_cache_create(HASH_BUCKET_BITS);
3136 }
3137
3138 void ext4_xattr_destroy_cache(struct mb_cache *cache)
3139 {
3140 if (cache)
3141 mb_cache_destroy(cache);
3142 }
3143
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