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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
77static void ext4_xattr_block_cache_insert(struct mb_cache *,
78 struct buffer_head *);
79static struct buffer_head *
80ext4_xattr_block_cache_find(struct inode *, struct ext4_xattr_header *,
81 struct mb_cache_entry **);
82static __le32 ext4_xattr_hash_entry(char *name, size_t name_len, __le32 *value,
83 size_t value_count);
84static __le32 ext4_xattr_hash_entry_signed(char *name, size_t name_len, __le32 *value,
85 size_t value_count);
86static void ext4_xattr_rehash(struct ext4_xattr_header *);
87
88static const struct xattr_handler * const ext4_xattr_handler_map[] = {
89 [EXT4_XATTR_INDEX_USER] = &ext4_xattr_user_handler,
90#ifdef CONFIG_EXT4_FS_POSIX_ACL
91 [EXT4_XATTR_INDEX_POSIX_ACL_ACCESS] = &posix_acl_access_xattr_handler,
92 [EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT] = &posix_acl_default_xattr_handler,
93#endif
94 [EXT4_XATTR_INDEX_TRUSTED] = &ext4_xattr_trusted_handler,
95#ifdef CONFIG_EXT4_FS_SECURITY
96 [EXT4_XATTR_INDEX_SECURITY] = &ext4_xattr_security_handler,
97#endif
98 [EXT4_XATTR_INDEX_HURD] = &ext4_xattr_hurd_handler,
99};
100
101const struct xattr_handler *ext4_xattr_handlers[] = {
102 &ext4_xattr_user_handler,
103 &ext4_xattr_trusted_handler,
104#ifdef CONFIG_EXT4_FS_POSIX_ACL
105 &posix_acl_access_xattr_handler,
106 &posix_acl_default_xattr_handler,
107#endif
108#ifdef CONFIG_EXT4_FS_SECURITY
109 &ext4_xattr_security_handler,
110#endif
111 &ext4_xattr_hurd_handler,
112 NULL
113};
114
115#define EA_BLOCK_CACHE(inode) (((struct ext4_sb_info *) \
116 inode->i_sb->s_fs_info)->s_ea_block_cache)
117
118#define EA_INODE_CACHE(inode) (((struct ext4_sb_info *) \
119 inode->i_sb->s_fs_info)->s_ea_inode_cache)
120
121static int
122ext4_expand_inode_array(struct ext4_xattr_inode_array **ea_inode_array,
123 struct inode *inode);
124
125#ifdef CONFIG_LOCKDEP
126void ext4_xattr_inode_set_class(struct inode *ea_inode)
127{
128 lockdep_set_subclass(&ea_inode->i_rwsem, 1);
129}
130#endif
131
132static __le32 ext4_xattr_block_csum(struct inode *inode,
133 sector_t block_nr,
134 struct ext4_xattr_header *hdr)
135{
136 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
137 __u32 csum;
138 __le64 dsk_block_nr = cpu_to_le64(block_nr);
139 __u32 dummy_csum = 0;
140 int offset = offsetof(struct ext4_xattr_header, h_checksum);
141
142 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&dsk_block_nr,
143 sizeof(dsk_block_nr));
144 csum = ext4_chksum(sbi, csum, (__u8 *)hdr, offset);
145 csum = ext4_chksum(sbi, csum, (__u8 *)&dummy_csum, sizeof(dummy_csum));
146 offset += sizeof(dummy_csum);
147 csum = ext4_chksum(sbi, csum, (__u8 *)hdr + offset,
148 EXT4_BLOCK_SIZE(inode->i_sb) - offset);
149
150 return cpu_to_le32(csum);
151}
152
153static int ext4_xattr_block_csum_verify(struct inode *inode,
154 struct buffer_head *bh)
155{
156 struct ext4_xattr_header *hdr = BHDR(bh);
157 int ret = 1;
158
159 if (ext4_has_metadata_csum(inode->i_sb)) {
160 lock_buffer(bh);
161 ret = (hdr->h_checksum == ext4_xattr_block_csum(inode,
162 bh->b_blocknr, hdr));
163 unlock_buffer(bh);
164 }
165 return ret;
166}
167
168static void ext4_xattr_block_csum_set(struct inode *inode,
169 struct buffer_head *bh)
170{
171 if (ext4_has_metadata_csum(inode->i_sb))
172 BHDR(bh)->h_checksum = ext4_xattr_block_csum(inode,
173 bh->b_blocknr, BHDR(bh));
174}
175
176static inline const struct xattr_handler *
177ext4_xattr_handler(int name_index)
178{
179 const struct xattr_handler *handler = NULL;
180
181 if (name_index > 0 && name_index < ARRAY_SIZE(ext4_xattr_handler_map))
182 handler = ext4_xattr_handler_map[name_index];
183 return handler;
184}
185
186static int
187ext4_xattr_check_entries(struct ext4_xattr_entry *entry, void *end,
188 void *value_start)
189{
190 struct ext4_xattr_entry *e = entry;
191
192 /* Find the end of the names list */
193 while (!IS_LAST_ENTRY(e)) {
194 struct ext4_xattr_entry *next = EXT4_XATTR_NEXT(e);
195 if ((void *)next >= end)
196 return -EFSCORRUPTED;
197 if (strnlen(e->e_name, e->e_name_len) != e->e_name_len)
198 return -EFSCORRUPTED;
199 e = next;
200 }
201
202 /* Check the values */
203 while (!IS_LAST_ENTRY(entry)) {
204 u32 size = le32_to_cpu(entry->e_value_size);
205
206 if (size > EXT4_XATTR_SIZE_MAX)
207 return -EFSCORRUPTED;
208
209 if (size != 0 && entry->e_value_inum == 0) {
210 u16 offs = le16_to_cpu(entry->e_value_offs);
211 void *value;
212
213 /*
214 * The value cannot overlap the names, and the value
215 * with padding cannot extend beyond 'end'. Check both
216 * the padded and unpadded sizes, since the size may
217 * overflow to 0 when adding padding.
218 */
219 if (offs > end - value_start)
220 return -EFSCORRUPTED;
221 value = value_start + offs;
222 if (value < (void *)e + sizeof(u32) ||
223 size > end - value ||
224 EXT4_XATTR_SIZE(size) > end - value)
225 return -EFSCORRUPTED;
226 }
227 entry = EXT4_XATTR_NEXT(entry);
228 }
229
230 return 0;
231}
232
233static inline int
234__ext4_xattr_check_block(struct inode *inode, struct buffer_head *bh,
235 const char *function, unsigned int line)
236{
237 int error = -EFSCORRUPTED;
238
239 if (BHDR(bh)->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC) ||
240 BHDR(bh)->h_blocks != cpu_to_le32(1))
241 goto errout;
242 if (buffer_verified(bh))
243 return 0;
244
245 error = -EFSBADCRC;
246 if (!ext4_xattr_block_csum_verify(inode, bh))
247 goto errout;
248 error = ext4_xattr_check_entries(BFIRST(bh), bh->b_data + bh->b_size,
249 bh->b_data);
250errout:
251 if (error)
252 __ext4_error_inode(inode, function, line, 0, -error,
253 "corrupted xattr block %llu",
254 (unsigned long long) bh->b_blocknr);
255 else
256 set_buffer_verified(bh);
257 return error;
258}
259
260#define ext4_xattr_check_block(inode, bh) \
261 __ext4_xattr_check_block((inode), (bh), __func__, __LINE__)
262
263
264static int
265__xattr_check_inode(struct inode *inode, struct ext4_xattr_ibody_header *header,
266 void *end, const char *function, unsigned int line)
267{
268 int error = -EFSCORRUPTED;
269
270 if (end - (void *)header < sizeof(*header) + sizeof(u32) ||
271 (header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC)))
272 goto errout;
273 error = ext4_xattr_check_entries(IFIRST(header), end, IFIRST(header));
274errout:
275 if (error)
276 __ext4_error_inode(inode, function, line, 0, -error,
277 "corrupted in-inode xattr");
278 return error;
279}
280
281#define xattr_check_inode(inode, header, end) \
282 __xattr_check_inode((inode), (header), (end), __func__, __LINE__)
283
284static int
285xattr_find_entry(struct inode *inode, struct ext4_xattr_entry **pentry,
286 void *end, int name_index, const char *name, int sorted)
287{
288 struct ext4_xattr_entry *entry, *next;
289 size_t name_len;
290 int cmp = 1;
291
292 if (name == NULL)
293 return -EINVAL;
294 name_len = strlen(name);
295 for (entry = *pentry; !IS_LAST_ENTRY(entry); entry = next) {
296 next = EXT4_XATTR_NEXT(entry);
297 if ((void *) next >= end) {
298 EXT4_ERROR_INODE(inode, "corrupted xattr entries");
299 return -EFSCORRUPTED;
300 }
301 cmp = name_index - entry->e_name_index;
302 if (!cmp)
303 cmp = name_len - entry->e_name_len;
304 if (!cmp)
305 cmp = memcmp(name, entry->e_name, name_len);
306 if (cmp <= 0 && (sorted || cmp == 0))
307 break;
308 }
309 *pentry = entry;
310 return cmp ? -ENODATA : 0;
311}
312
313static u32
314ext4_xattr_inode_hash(struct ext4_sb_info *sbi, const void *buffer, size_t size)
315{
316 return ext4_chksum(sbi, sbi->s_csum_seed, buffer, size);
317}
318
319static u64 ext4_xattr_inode_get_ref(struct inode *ea_inode)
320{
321 return ((u64)ea_inode->i_ctime.tv_sec << 32) |
322 (u32) inode_peek_iversion_raw(ea_inode);
323}
324
325static void ext4_xattr_inode_set_ref(struct inode *ea_inode, u64 ref_count)
326{
327 ea_inode->i_ctime.tv_sec = (u32)(ref_count >> 32);
328 inode_set_iversion_raw(ea_inode, ref_count & 0xffffffff);
329}
330
331static u32 ext4_xattr_inode_get_hash(struct inode *ea_inode)
332{
333 return (u32)ea_inode->i_atime.tv_sec;
334}
335
336static void ext4_xattr_inode_set_hash(struct inode *ea_inode, u32 hash)
337{
338 ea_inode->i_atime.tv_sec = hash;
339}
340
341/*
342 * Read the EA value from an inode.
343 */
344static int ext4_xattr_inode_read(struct inode *ea_inode, void *buf, size_t size)
345{
346 int blocksize = 1 << ea_inode->i_blkbits;
347 int bh_count = (size + blocksize - 1) >> ea_inode->i_blkbits;
348 int tail_size = (size % blocksize) ?: blocksize;
349 struct buffer_head *bhs_inline[8];
350 struct buffer_head **bhs = bhs_inline;
351 int i, ret;
352
353 if (bh_count > ARRAY_SIZE(bhs_inline)) {
354 bhs = kmalloc_array(bh_count, sizeof(*bhs), GFP_NOFS);
355 if (!bhs)
356 return -ENOMEM;
357 }
358
359 ret = ext4_bread_batch(ea_inode, 0 /* block */, bh_count,
360 true /* wait */, bhs);
361 if (ret)
362 goto free_bhs;
363
364 for (i = 0; i < bh_count; i++) {
365 /* There shouldn't be any holes in ea_inode. */
366 if (!bhs[i]) {
367 ret = -EFSCORRUPTED;
368 goto put_bhs;
369 }
370 memcpy((char *)buf + blocksize * i, bhs[i]->b_data,
371 i < bh_count - 1 ? blocksize : tail_size);
372 }
373 ret = 0;
374put_bhs:
375 for (i = 0; i < bh_count; i++)
376 brelse(bhs[i]);
377free_bhs:
378 if (bhs != bhs_inline)
379 kfree(bhs);
380 return ret;
381}
382
383#define EXT4_XATTR_INODE_GET_PARENT(inode) ((__u32)(inode)->i_mtime.tv_sec)
384
385static int ext4_xattr_inode_iget(struct inode *parent, unsigned long ea_ino,
386 u32 ea_inode_hash, struct inode **ea_inode)
387{
388 struct inode *inode;
389 int err;
390
391 inode = ext4_iget(parent->i_sb, ea_ino, EXT4_IGET_NORMAL);
392 if (IS_ERR(inode)) {
393 err = PTR_ERR(inode);
394 ext4_error(parent->i_sb,
395 "error while reading EA inode %lu err=%d", ea_ino,
396 err);
397 return err;
398 }
399
400 if (is_bad_inode(inode)) {
401 ext4_error(parent->i_sb,
402 "error while reading EA inode %lu is_bad_inode",
403 ea_ino);
404 err = -EIO;
405 goto error;
406 }
407
408 if (!(EXT4_I(inode)->i_flags & EXT4_EA_INODE_FL)) {
409 ext4_error(parent->i_sb,
410 "EA inode %lu does not have EXT4_EA_INODE_FL flag",
411 ea_ino);
412 err = -EINVAL;
413 goto error;
414 }
415
416 ext4_xattr_inode_set_class(inode);
417
418 /*
419 * Check whether this is an old Lustre-style xattr inode. Lustre
420 * implementation does not have hash validation, rather it has a
421 * backpointer from ea_inode to the parent inode.
422 */
423 if (ea_inode_hash != ext4_xattr_inode_get_hash(inode) &&
424 EXT4_XATTR_INODE_GET_PARENT(inode) == parent->i_ino &&
425 inode->i_generation == parent->i_generation) {
426 ext4_set_inode_state(inode, EXT4_STATE_LUSTRE_EA_INODE);
427 ext4_xattr_inode_set_ref(inode, 1);
428 } else {
429 inode_lock(inode);
430 inode->i_flags |= S_NOQUOTA;
431 inode_unlock(inode);
432 }
433
434 *ea_inode = inode;
435 return 0;
436error:
437 iput(inode);
438 return err;
439}
440
441/* Remove entry from mbcache when EA inode is getting evicted */
442void ext4_evict_ea_inode(struct inode *inode)
443{
444 struct mb_cache_entry *oe;
445
446 if (!EA_INODE_CACHE(inode))
447 return;
448 /* Wait for entry to get unused so that we can remove it */
449 while ((oe = mb_cache_entry_delete_or_get(EA_INODE_CACHE(inode),
450 ext4_xattr_inode_get_hash(inode), inode->i_ino))) {
451 mb_cache_entry_wait_unused(oe);
452 mb_cache_entry_put(EA_INODE_CACHE(inode), oe);
453 }
454}
455
456static int
457ext4_xattr_inode_verify_hashes(struct inode *ea_inode,
458 struct ext4_xattr_entry *entry, void *buffer,
459 size_t size)
460{
461 u32 hash;
462
463 /* Verify stored hash matches calculated hash. */
464 hash = ext4_xattr_inode_hash(EXT4_SB(ea_inode->i_sb), buffer, size);
465 if (hash != ext4_xattr_inode_get_hash(ea_inode))
466 return -EFSCORRUPTED;
467
468 if (entry) {
469 __le32 e_hash, tmp_data;
470
471 /* Verify entry hash. */
472 tmp_data = cpu_to_le32(hash);
473 e_hash = ext4_xattr_hash_entry(entry->e_name, entry->e_name_len,
474 &tmp_data, 1);
475 /* All good? */
476 if (e_hash == entry->e_hash)
477 return 0;
478
479 /*
480 * Not good. Maybe the entry hash was calculated
481 * using the buggy signed char version?
482 */
483 e_hash = ext4_xattr_hash_entry_signed(entry->e_name, entry->e_name_len,
484 &tmp_data, 1);
485 /* Still no match - bad */
486 if (e_hash != entry->e_hash)
487 return -EFSCORRUPTED;
488
489 /* Let people know about old hash */
490 pr_warn_once("ext4: filesystem with signed xattr name hash");
491 }
492 return 0;
493}
494
495/*
496 * Read xattr value from the EA inode.
497 */
498static int
499ext4_xattr_inode_get(struct inode *inode, struct ext4_xattr_entry *entry,
500 void *buffer, size_t size)
501{
502 struct mb_cache *ea_inode_cache = EA_INODE_CACHE(inode);
503 struct inode *ea_inode;
504 int err;
505
506 err = ext4_xattr_inode_iget(inode, le32_to_cpu(entry->e_value_inum),
507 le32_to_cpu(entry->e_hash), &ea_inode);
508 if (err) {
509 ea_inode = NULL;
510 goto out;
511 }
512
513 if (i_size_read(ea_inode) != size) {
514 ext4_warning_inode(ea_inode,
515 "ea_inode file size=%llu entry size=%zu",
516 i_size_read(ea_inode), size);
517 err = -EFSCORRUPTED;
518 goto out;
519 }
520
521 err = ext4_xattr_inode_read(ea_inode, buffer, size);
522 if (err)
523 goto out;
524
525 if (!ext4_test_inode_state(ea_inode, EXT4_STATE_LUSTRE_EA_INODE)) {
526 err = ext4_xattr_inode_verify_hashes(ea_inode, entry, buffer,
527 size);
528 if (err) {
529 ext4_warning_inode(ea_inode,
530 "EA inode hash validation failed");
531 goto out;
532 }
533
534 if (ea_inode_cache)
535 mb_cache_entry_create(ea_inode_cache, GFP_NOFS,
536 ext4_xattr_inode_get_hash(ea_inode),
537 ea_inode->i_ino, true /* reusable */);
538 }
539out:
540 iput(ea_inode);
541 return err;
542}
543
544static int
545ext4_xattr_block_get(struct inode *inode, int name_index, const char *name,
546 void *buffer, size_t buffer_size)
547{
548 struct buffer_head *bh = NULL;
549 struct ext4_xattr_entry *entry;
550 size_t size;
551 void *end;
552 int error;
553 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
554
555 ea_idebug(inode, "name=%d.%s, buffer=%p, buffer_size=%ld",
556 name_index, name, buffer, (long)buffer_size);
557
558 if (!EXT4_I(inode)->i_file_acl)
559 return -ENODATA;
560 ea_idebug(inode, "reading block %llu",
561 (unsigned long long)EXT4_I(inode)->i_file_acl);
562 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
563 if (IS_ERR(bh))
564 return PTR_ERR(bh);
565 ea_bdebug(bh, "b_count=%d, refcount=%d",
566 atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount));
567 error = ext4_xattr_check_block(inode, bh);
568 if (error)
569 goto cleanup;
570 ext4_xattr_block_cache_insert(ea_block_cache, bh);
571 entry = BFIRST(bh);
572 end = bh->b_data + bh->b_size;
573 error = xattr_find_entry(inode, &entry, end, name_index, name, 1);
574 if (error)
575 goto cleanup;
576 size = le32_to_cpu(entry->e_value_size);
577 error = -ERANGE;
578 if (unlikely(size > EXT4_XATTR_SIZE_MAX))
579 goto cleanup;
580 if (buffer) {
581 if (size > buffer_size)
582 goto cleanup;
583 if (entry->e_value_inum) {
584 error = ext4_xattr_inode_get(inode, entry, buffer,
585 size);
586 if (error)
587 goto cleanup;
588 } else {
589 u16 offset = le16_to_cpu(entry->e_value_offs);
590 void *p = bh->b_data + offset;
591
592 if (unlikely(p + size > end))
593 goto cleanup;
594 memcpy(buffer, p, size);
595 }
596 }
597 error = size;
598
599cleanup:
600 brelse(bh);
601 return error;
602}
603
604int
605ext4_xattr_ibody_get(struct inode *inode, int name_index, const char *name,
606 void *buffer, size_t buffer_size)
607{
608 struct ext4_xattr_ibody_header *header;
609 struct ext4_xattr_entry *entry;
610 struct ext4_inode *raw_inode;
611 struct ext4_iloc iloc;
612 size_t size;
613 void *end;
614 int error;
615
616 if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR))
617 return -ENODATA;
618 error = ext4_get_inode_loc(inode, &iloc);
619 if (error)
620 return error;
621 raw_inode = ext4_raw_inode(&iloc);
622 header = IHDR(inode, raw_inode);
623 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
624 error = xattr_check_inode(inode, header, end);
625 if (error)
626 goto cleanup;
627 entry = IFIRST(header);
628 error = xattr_find_entry(inode, &entry, end, name_index, name, 0);
629 if (error)
630 goto cleanup;
631 size = le32_to_cpu(entry->e_value_size);
632 error = -ERANGE;
633 if (unlikely(size > EXT4_XATTR_SIZE_MAX))
634 goto cleanup;
635 if (buffer) {
636 if (size > buffer_size)
637 goto cleanup;
638 if (entry->e_value_inum) {
639 error = ext4_xattr_inode_get(inode, entry, buffer,
640 size);
641 if (error)
642 goto cleanup;
643 } else {
644 u16 offset = le16_to_cpu(entry->e_value_offs);
645 void *p = (void *)IFIRST(header) + offset;
646
647 if (unlikely(p + size > end))
648 goto cleanup;
649 memcpy(buffer, p, size);
650 }
651 }
652 error = size;
653
654cleanup:
655 brelse(iloc.bh);
656 return error;
657}
658
659/*
660 * ext4_xattr_get()
661 *
662 * Copy an extended attribute into the buffer
663 * provided, or compute the buffer size required.
664 * Buffer is NULL to compute the size of the buffer required.
665 *
666 * Returns a negative error number on failure, or the number of bytes
667 * used / required on success.
668 */
669int
670ext4_xattr_get(struct inode *inode, int name_index, const char *name,
671 void *buffer, size_t buffer_size)
672{
673 int error;
674
675 if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
676 return -EIO;
677
678 if (strlen(name) > 255)
679 return -ERANGE;
680
681 down_read(&EXT4_I(inode)->xattr_sem);
682 error = ext4_xattr_ibody_get(inode, name_index, name, buffer,
683 buffer_size);
684 if (error == -ENODATA)
685 error = ext4_xattr_block_get(inode, name_index, name, buffer,
686 buffer_size);
687 up_read(&EXT4_I(inode)->xattr_sem);
688 return error;
689}
690
691static int
692ext4_xattr_list_entries(struct dentry *dentry, struct ext4_xattr_entry *entry,
693 char *buffer, size_t buffer_size)
694{
695 size_t rest = buffer_size;
696
697 for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) {
698 const struct xattr_handler *handler =
699 ext4_xattr_handler(entry->e_name_index);
700
701 if (handler && (!handler->list || handler->list(dentry))) {
702 const char *prefix = handler->prefix ?: handler->name;
703 size_t prefix_len = strlen(prefix);
704 size_t size = prefix_len + entry->e_name_len + 1;
705
706 if (buffer) {
707 if (size > rest)
708 return -ERANGE;
709 memcpy(buffer, prefix, prefix_len);
710 buffer += prefix_len;
711 memcpy(buffer, entry->e_name, entry->e_name_len);
712 buffer += entry->e_name_len;
713 *buffer++ = 0;
714 }
715 rest -= size;
716 }
717 }
718 return buffer_size - rest; /* total size */
719}
720
721static int
722ext4_xattr_block_list(struct dentry *dentry, char *buffer, size_t buffer_size)
723{
724 struct inode *inode = d_inode(dentry);
725 struct buffer_head *bh = NULL;
726 int error;
727
728 ea_idebug(inode, "buffer=%p, buffer_size=%ld",
729 buffer, (long)buffer_size);
730
731 if (!EXT4_I(inode)->i_file_acl)
732 return 0;
733 ea_idebug(inode, "reading block %llu",
734 (unsigned long long)EXT4_I(inode)->i_file_acl);
735 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
736 if (IS_ERR(bh))
737 return PTR_ERR(bh);
738 ea_bdebug(bh, "b_count=%d, refcount=%d",
739 atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount));
740 error = ext4_xattr_check_block(inode, bh);
741 if (error)
742 goto cleanup;
743 ext4_xattr_block_cache_insert(EA_BLOCK_CACHE(inode), bh);
744 error = ext4_xattr_list_entries(dentry, BFIRST(bh), buffer,
745 buffer_size);
746cleanup:
747 brelse(bh);
748 return error;
749}
750
751static int
752ext4_xattr_ibody_list(struct dentry *dentry, char *buffer, size_t buffer_size)
753{
754 struct inode *inode = d_inode(dentry);
755 struct ext4_xattr_ibody_header *header;
756 struct ext4_inode *raw_inode;
757 struct ext4_iloc iloc;
758 void *end;
759 int error;
760
761 if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR))
762 return 0;
763 error = ext4_get_inode_loc(inode, &iloc);
764 if (error)
765 return error;
766 raw_inode = ext4_raw_inode(&iloc);
767 header = IHDR(inode, raw_inode);
768 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
769 error = xattr_check_inode(inode, header, end);
770 if (error)
771 goto cleanup;
772 error = ext4_xattr_list_entries(dentry, IFIRST(header),
773 buffer, buffer_size);
774
775cleanup:
776 brelse(iloc.bh);
777 return error;
778}
779
780/*
781 * Inode operation listxattr()
782 *
783 * d_inode(dentry)->i_rwsem: don't care
784 *
785 * Copy a list of attribute names into the buffer
786 * provided, or compute the buffer size required.
787 * Buffer is NULL to compute the size of the buffer required.
788 *
789 * Returns a negative error number on failure, or the number of bytes
790 * used / required on success.
791 */
792ssize_t
793ext4_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
794{
795 int ret, ret2;
796
797 down_read(&EXT4_I(d_inode(dentry))->xattr_sem);
798 ret = ret2 = ext4_xattr_ibody_list(dentry, buffer, buffer_size);
799 if (ret < 0)
800 goto errout;
801 if (buffer) {
802 buffer += ret;
803 buffer_size -= ret;
804 }
805 ret = ext4_xattr_block_list(dentry, buffer, buffer_size);
806 if (ret < 0)
807 goto errout;
808 ret += ret2;
809errout:
810 up_read(&EXT4_I(d_inode(dentry))->xattr_sem);
811 return ret;
812}
813
814/*
815 * If the EXT4_FEATURE_COMPAT_EXT_ATTR feature of this file system is
816 * not set, set it.
817 */
818static void ext4_xattr_update_super_block(handle_t *handle,
819 struct super_block *sb)
820{
821 if (ext4_has_feature_xattr(sb))
822 return;
823
824 BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access");
825 if (ext4_journal_get_write_access(handle, sb, EXT4_SB(sb)->s_sbh,
826 EXT4_JTR_NONE) == 0) {
827 lock_buffer(EXT4_SB(sb)->s_sbh);
828 ext4_set_feature_xattr(sb);
829 ext4_superblock_csum_set(sb);
830 unlock_buffer(EXT4_SB(sb)->s_sbh);
831 ext4_handle_dirty_metadata(handle, NULL, EXT4_SB(sb)->s_sbh);
832 }
833}
834
835int ext4_get_inode_usage(struct inode *inode, qsize_t *usage)
836{
837 struct ext4_iloc iloc = { .bh = NULL };
838 struct buffer_head *bh = NULL;
839 struct ext4_inode *raw_inode;
840 struct ext4_xattr_ibody_header *header;
841 struct ext4_xattr_entry *entry;
842 qsize_t ea_inode_refs = 0;
843 void *end;
844 int ret;
845
846 lockdep_assert_held_read(&EXT4_I(inode)->xattr_sem);
847
848 if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
849 ret = ext4_get_inode_loc(inode, &iloc);
850 if (ret)
851 goto out;
852 raw_inode = ext4_raw_inode(&iloc);
853 header = IHDR(inode, raw_inode);
854 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
855 ret = xattr_check_inode(inode, header, end);
856 if (ret)
857 goto out;
858
859 for (entry = IFIRST(header); !IS_LAST_ENTRY(entry);
860 entry = EXT4_XATTR_NEXT(entry))
861 if (entry->e_value_inum)
862 ea_inode_refs++;
863 }
864
865 if (EXT4_I(inode)->i_file_acl) {
866 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
867 if (IS_ERR(bh)) {
868 ret = PTR_ERR(bh);
869 bh = NULL;
870 goto out;
871 }
872
873 ret = ext4_xattr_check_block(inode, bh);
874 if (ret)
875 goto out;
876
877 for (entry = BFIRST(bh); !IS_LAST_ENTRY(entry);
878 entry = EXT4_XATTR_NEXT(entry))
879 if (entry->e_value_inum)
880 ea_inode_refs++;
881 }
882 *usage = ea_inode_refs + 1;
883 ret = 0;
884out:
885 brelse(iloc.bh);
886 brelse(bh);
887 return ret;
888}
889
890static inline size_t round_up_cluster(struct inode *inode, size_t length)
891{
892 struct super_block *sb = inode->i_sb;
893 size_t cluster_size = 1 << (EXT4_SB(sb)->s_cluster_bits +
894 inode->i_blkbits);
895 size_t mask = ~(cluster_size - 1);
896
897 return (length + cluster_size - 1) & mask;
898}
899
900static int ext4_xattr_inode_alloc_quota(struct inode *inode, size_t len)
901{
902 int err;
903
904 err = dquot_alloc_inode(inode);
905 if (err)
906 return err;
907 err = dquot_alloc_space_nodirty(inode, round_up_cluster(inode, len));
908 if (err)
909 dquot_free_inode(inode);
910 return err;
911}
912
913static void ext4_xattr_inode_free_quota(struct inode *parent,
914 struct inode *ea_inode,
915 size_t len)
916{
917 if (ea_inode &&
918 ext4_test_inode_state(ea_inode, EXT4_STATE_LUSTRE_EA_INODE))
919 return;
920 dquot_free_space_nodirty(parent, round_up_cluster(parent, len));
921 dquot_free_inode(parent);
922}
923
924int __ext4_xattr_set_credits(struct super_block *sb, struct inode *inode,
925 struct buffer_head *block_bh, size_t value_len,
926 bool is_create)
927{
928 int credits;
929 int blocks;
930
931 /*
932 * 1) Owner inode update
933 * 2) Ref count update on old xattr block
934 * 3) new xattr block
935 * 4) block bitmap update for new xattr block
936 * 5) group descriptor for new xattr block
937 * 6) block bitmap update for old xattr block
938 * 7) group descriptor for old block
939 *
940 * 6 & 7 can happen if we have two racing threads T_a and T_b
941 * which are each trying to set an xattr on inodes I_a and I_b
942 * which were both initially sharing an xattr block.
943 */
944 credits = 7;
945
946 /* Quota updates. */
947 credits += EXT4_MAXQUOTAS_TRANS_BLOCKS(sb);
948
949 /*
950 * In case of inline data, we may push out the data to a block,
951 * so we need to reserve credits for this eventuality
952 */
953 if (inode && ext4_has_inline_data(inode))
954 credits += ext4_writepage_trans_blocks(inode) + 1;
955
956 /* We are done if ea_inode feature is not enabled. */
957 if (!ext4_has_feature_ea_inode(sb))
958 return credits;
959
960 /* New ea_inode, inode map, block bitmap, group descriptor. */
961 credits += 4;
962
963 /* Data blocks. */
964 blocks = (value_len + sb->s_blocksize - 1) >> sb->s_blocksize_bits;
965
966 /* Indirection block or one level of extent tree. */
967 blocks += 1;
968
969 /* Block bitmap and group descriptor updates for each block. */
970 credits += blocks * 2;
971
972 /* Blocks themselves. */
973 credits += blocks;
974
975 if (!is_create) {
976 /* Dereference ea_inode holding old xattr value.
977 * Old ea_inode, inode map, block bitmap, group descriptor.
978 */
979 credits += 4;
980
981 /* Data blocks for old ea_inode. */
982 blocks = XATTR_SIZE_MAX >> sb->s_blocksize_bits;
983
984 /* Indirection block or one level of extent tree for old
985 * ea_inode.
986 */
987 blocks += 1;
988
989 /* Block bitmap and group descriptor updates for each block. */
990 credits += blocks * 2;
991 }
992
993 /* We may need to clone the existing xattr block in which case we need
994 * to increment ref counts for existing ea_inodes referenced by it.
995 */
996 if (block_bh) {
997 struct ext4_xattr_entry *entry = BFIRST(block_bh);
998
999 for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry))
1000 if (entry->e_value_inum)
1001 /* Ref count update on ea_inode. */
1002 credits += 1;
1003 }
1004 return credits;
1005}
1006
1007static int ext4_xattr_inode_update_ref(handle_t *handle, struct inode *ea_inode,
1008 int ref_change)
1009{
1010 struct ext4_iloc iloc;
1011 s64 ref_count;
1012 int ret;
1013
1014 inode_lock(ea_inode);
1015
1016 ret = ext4_reserve_inode_write(handle, ea_inode, &iloc);
1017 if (ret)
1018 goto out;
1019
1020 ref_count = ext4_xattr_inode_get_ref(ea_inode);
1021 ref_count += ref_change;
1022 ext4_xattr_inode_set_ref(ea_inode, ref_count);
1023
1024 if (ref_change > 0) {
1025 WARN_ONCE(ref_count <= 0, "EA inode %lu ref_count=%lld",
1026 ea_inode->i_ino, ref_count);
1027
1028 if (ref_count == 1) {
1029 WARN_ONCE(ea_inode->i_nlink, "EA inode %lu i_nlink=%u",
1030 ea_inode->i_ino, ea_inode->i_nlink);
1031
1032 set_nlink(ea_inode, 1);
1033 ext4_orphan_del(handle, ea_inode);
1034 }
1035 } else {
1036 WARN_ONCE(ref_count < 0, "EA inode %lu ref_count=%lld",
1037 ea_inode->i_ino, ref_count);
1038
1039 if (ref_count == 0) {
1040 WARN_ONCE(ea_inode->i_nlink != 1,
1041 "EA inode %lu i_nlink=%u",
1042 ea_inode->i_ino, ea_inode->i_nlink);
1043
1044 clear_nlink(ea_inode);
1045 ext4_orphan_add(handle, ea_inode);
1046 }
1047 }
1048
1049 ret = ext4_mark_iloc_dirty(handle, ea_inode, &iloc);
1050 if (ret)
1051 ext4_warning_inode(ea_inode,
1052 "ext4_mark_iloc_dirty() failed ret=%d", ret);
1053out:
1054 inode_unlock(ea_inode);
1055 return ret;
1056}
1057
1058static int ext4_xattr_inode_inc_ref(handle_t *handle, struct inode *ea_inode)
1059{
1060 return ext4_xattr_inode_update_ref(handle, ea_inode, 1);
1061}
1062
1063static int ext4_xattr_inode_dec_ref(handle_t *handle, struct inode *ea_inode)
1064{
1065 return ext4_xattr_inode_update_ref(handle, ea_inode, -1);
1066}
1067
1068static int ext4_xattr_inode_inc_ref_all(handle_t *handle, struct inode *parent,
1069 struct ext4_xattr_entry *first)
1070{
1071 struct inode *ea_inode;
1072 struct ext4_xattr_entry *entry;
1073 struct ext4_xattr_entry *failed_entry;
1074 unsigned int ea_ino;
1075 int err, saved_err;
1076
1077 for (entry = first; !IS_LAST_ENTRY(entry);
1078 entry = EXT4_XATTR_NEXT(entry)) {
1079 if (!entry->e_value_inum)
1080 continue;
1081 ea_ino = le32_to_cpu(entry->e_value_inum);
1082 err = ext4_xattr_inode_iget(parent, ea_ino,
1083 le32_to_cpu(entry->e_hash),
1084 &ea_inode);
1085 if (err)
1086 goto cleanup;
1087 err = ext4_xattr_inode_inc_ref(handle, ea_inode);
1088 if (err) {
1089 ext4_warning_inode(ea_inode, "inc ref error %d", err);
1090 iput(ea_inode);
1091 goto cleanup;
1092 }
1093 iput(ea_inode);
1094 }
1095 return 0;
1096
1097cleanup:
1098 saved_err = err;
1099 failed_entry = entry;
1100
1101 for (entry = first; entry != failed_entry;
1102 entry = EXT4_XATTR_NEXT(entry)) {
1103 if (!entry->e_value_inum)
1104 continue;
1105 ea_ino = le32_to_cpu(entry->e_value_inum);
1106 err = ext4_xattr_inode_iget(parent, ea_ino,
1107 le32_to_cpu(entry->e_hash),
1108 &ea_inode);
1109 if (err) {
1110 ext4_warning(parent->i_sb,
1111 "cleanup ea_ino %u iget error %d", ea_ino,
1112 err);
1113 continue;
1114 }
1115 err = ext4_xattr_inode_dec_ref(handle, ea_inode);
1116 if (err)
1117 ext4_warning_inode(ea_inode, "cleanup dec ref error %d",
1118 err);
1119 iput(ea_inode);
1120 }
1121 return saved_err;
1122}
1123
1124static int ext4_xattr_restart_fn(handle_t *handle, struct inode *inode,
1125 struct buffer_head *bh, bool block_csum, bool dirty)
1126{
1127 int error;
1128
1129 if (bh && dirty) {
1130 if (block_csum)
1131 ext4_xattr_block_csum_set(inode, bh);
1132 error = ext4_handle_dirty_metadata(handle, NULL, bh);
1133 if (error) {
1134 ext4_warning(inode->i_sb, "Handle metadata (error %d)",
1135 error);
1136 return error;
1137 }
1138 }
1139 return 0;
1140}
1141
1142static void
1143ext4_xattr_inode_dec_ref_all(handle_t *handle, struct inode *parent,
1144 struct buffer_head *bh,
1145 struct ext4_xattr_entry *first, bool block_csum,
1146 struct ext4_xattr_inode_array **ea_inode_array,
1147 int extra_credits, bool skip_quota)
1148{
1149 struct inode *ea_inode;
1150 struct ext4_xattr_entry *entry;
1151 bool dirty = false;
1152 unsigned int ea_ino;
1153 int err;
1154 int credits;
1155
1156 /* One credit for dec ref on ea_inode, one for orphan list addition, */
1157 credits = 2 + extra_credits;
1158
1159 for (entry = first; !IS_LAST_ENTRY(entry);
1160 entry = EXT4_XATTR_NEXT(entry)) {
1161 if (!entry->e_value_inum)
1162 continue;
1163 ea_ino = le32_to_cpu(entry->e_value_inum);
1164 err = ext4_xattr_inode_iget(parent, ea_ino,
1165 le32_to_cpu(entry->e_hash),
1166 &ea_inode);
1167 if (err)
1168 continue;
1169
1170 err = ext4_expand_inode_array(ea_inode_array, ea_inode);
1171 if (err) {
1172 ext4_warning_inode(ea_inode,
1173 "Expand inode array err=%d", err);
1174 iput(ea_inode);
1175 continue;
1176 }
1177
1178 err = ext4_journal_ensure_credits_fn(handle, credits, credits,
1179 ext4_free_metadata_revoke_credits(parent->i_sb, 1),
1180 ext4_xattr_restart_fn(handle, parent, bh, block_csum,
1181 dirty));
1182 if (err < 0) {
1183 ext4_warning_inode(ea_inode, "Ensure credits err=%d",
1184 err);
1185 continue;
1186 }
1187 if (err > 0) {
1188 err = ext4_journal_get_write_access(handle,
1189 parent->i_sb, bh, EXT4_JTR_NONE);
1190 if (err) {
1191 ext4_warning_inode(ea_inode,
1192 "Re-get write access err=%d",
1193 err);
1194 continue;
1195 }
1196 }
1197
1198 err = ext4_xattr_inode_dec_ref(handle, ea_inode);
1199 if (err) {
1200 ext4_warning_inode(ea_inode, "ea_inode dec ref err=%d",
1201 err);
1202 continue;
1203 }
1204
1205 if (!skip_quota)
1206 ext4_xattr_inode_free_quota(parent, ea_inode,
1207 le32_to_cpu(entry->e_value_size));
1208
1209 /*
1210 * Forget about ea_inode within the same transaction that
1211 * decrements the ref count. This avoids duplicate decrements in
1212 * case the rest of the work spills over to subsequent
1213 * transactions.
1214 */
1215 entry->e_value_inum = 0;
1216 entry->e_value_size = 0;
1217
1218 dirty = true;
1219 }
1220
1221 if (dirty) {
1222 /*
1223 * Note that we are deliberately skipping csum calculation for
1224 * the final update because we do not expect any journal
1225 * restarts until xattr block is freed.
1226 */
1227
1228 err = ext4_handle_dirty_metadata(handle, NULL, bh);
1229 if (err)
1230 ext4_warning_inode(parent,
1231 "handle dirty metadata err=%d", err);
1232 }
1233}
1234
1235/*
1236 * Release the xattr block BH: If the reference count is > 1, decrement it;
1237 * otherwise free the block.
1238 */
1239static void
1240ext4_xattr_release_block(handle_t *handle, struct inode *inode,
1241 struct buffer_head *bh,
1242 struct ext4_xattr_inode_array **ea_inode_array,
1243 int extra_credits)
1244{
1245 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
1246 u32 hash, ref;
1247 int error = 0;
1248
1249 BUFFER_TRACE(bh, "get_write_access");
1250 error = ext4_journal_get_write_access(handle, inode->i_sb, bh,
1251 EXT4_JTR_NONE);
1252 if (error)
1253 goto out;
1254
1255retry_ref:
1256 lock_buffer(bh);
1257 hash = le32_to_cpu(BHDR(bh)->h_hash);
1258 ref = le32_to_cpu(BHDR(bh)->h_refcount);
1259 if (ref == 1) {
1260 ea_bdebug(bh, "refcount now=0; freeing");
1261 /*
1262 * This must happen under buffer lock for
1263 * ext4_xattr_block_set() to reliably detect freed block
1264 */
1265 if (ea_block_cache) {
1266 struct mb_cache_entry *oe;
1267
1268 oe = mb_cache_entry_delete_or_get(ea_block_cache, hash,
1269 bh->b_blocknr);
1270 if (oe) {
1271 unlock_buffer(bh);
1272 mb_cache_entry_wait_unused(oe);
1273 mb_cache_entry_put(ea_block_cache, oe);
1274 goto retry_ref;
1275 }
1276 }
1277 get_bh(bh);
1278 unlock_buffer(bh);
1279
1280 if (ext4_has_feature_ea_inode(inode->i_sb))
1281 ext4_xattr_inode_dec_ref_all(handle, inode, bh,
1282 BFIRST(bh),
1283 true /* block_csum */,
1284 ea_inode_array,
1285 extra_credits,
1286 true /* skip_quota */);
1287 ext4_free_blocks(handle, inode, bh, 0, 1,
1288 EXT4_FREE_BLOCKS_METADATA |
1289 EXT4_FREE_BLOCKS_FORGET);
1290 } else {
1291 ref--;
1292 BHDR(bh)->h_refcount = cpu_to_le32(ref);
1293 if (ref == EXT4_XATTR_REFCOUNT_MAX - 1) {
1294 struct mb_cache_entry *ce;
1295
1296 if (ea_block_cache) {
1297 ce = mb_cache_entry_get(ea_block_cache, hash,
1298 bh->b_blocknr);
1299 if (ce) {
1300 set_bit(MBE_REUSABLE_B, &ce->e_flags);
1301 mb_cache_entry_put(ea_block_cache, ce);
1302 }
1303 }
1304 }
1305
1306 ext4_xattr_block_csum_set(inode, bh);
1307 /*
1308 * Beware of this ugliness: Releasing of xattr block references
1309 * from different inodes can race and so we have to protect
1310 * from a race where someone else frees the block (and releases
1311 * its journal_head) before we are done dirtying the buffer. In
1312 * nojournal mode this race is harmless and we actually cannot
1313 * call ext4_handle_dirty_metadata() with locked buffer as
1314 * that function can call sync_dirty_buffer() so for that case
1315 * we handle the dirtying after unlocking the buffer.
1316 */
1317 if (ext4_handle_valid(handle))
1318 error = ext4_handle_dirty_metadata(handle, inode, bh);
1319 unlock_buffer(bh);
1320 if (!ext4_handle_valid(handle))
1321 error = ext4_handle_dirty_metadata(handle, inode, bh);
1322 if (IS_SYNC(inode))
1323 ext4_handle_sync(handle);
1324 dquot_free_block(inode, EXT4_C2B(EXT4_SB(inode->i_sb), 1));
1325 ea_bdebug(bh, "refcount now=%d; releasing",
1326 le32_to_cpu(BHDR(bh)->h_refcount));
1327 }
1328out:
1329 ext4_std_error(inode->i_sb, error);
1330 return;
1331}
1332
1333/*
1334 * Find the available free space for EAs. This also returns the total number of
1335 * bytes used by EA entries.
1336 */
1337static size_t ext4_xattr_free_space(struct ext4_xattr_entry *last,
1338 size_t *min_offs, void *base, int *total)
1339{
1340 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
1341 if (!last->e_value_inum && last->e_value_size) {
1342 size_t offs = le16_to_cpu(last->e_value_offs);
1343 if (offs < *min_offs)
1344 *min_offs = offs;
1345 }
1346 if (total)
1347 *total += EXT4_XATTR_LEN(last->e_name_len);
1348 }
1349 return (*min_offs - ((void *)last - base) - sizeof(__u32));
1350}
1351
1352/*
1353 * Write the value of the EA in an inode.
1354 */
1355static int ext4_xattr_inode_write(handle_t *handle, struct inode *ea_inode,
1356 const void *buf, int bufsize)
1357{
1358 struct buffer_head *bh = NULL;
1359 unsigned long block = 0;
1360 int blocksize = ea_inode->i_sb->s_blocksize;
1361 int max_blocks = (bufsize + blocksize - 1) >> ea_inode->i_blkbits;
1362 int csize, wsize = 0;
1363 int ret = 0, ret2 = 0;
1364 int retries = 0;
1365
1366retry:
1367 while (ret >= 0 && ret < max_blocks) {
1368 struct ext4_map_blocks map;
1369 map.m_lblk = block += ret;
1370 map.m_len = max_blocks -= ret;
1371
1372 ret = ext4_map_blocks(handle, ea_inode, &map,
1373 EXT4_GET_BLOCKS_CREATE);
1374 if (ret <= 0) {
1375 ext4_mark_inode_dirty(handle, ea_inode);
1376 if (ret == -ENOSPC &&
1377 ext4_should_retry_alloc(ea_inode->i_sb, &retries)) {
1378 ret = 0;
1379 goto retry;
1380 }
1381 break;
1382 }
1383 }
1384
1385 if (ret < 0)
1386 return ret;
1387
1388 block = 0;
1389 while (wsize < bufsize) {
1390 brelse(bh);
1391 csize = (bufsize - wsize) > blocksize ? blocksize :
1392 bufsize - wsize;
1393 bh = ext4_getblk(handle, ea_inode, block, 0);
1394 if (IS_ERR(bh))
1395 return PTR_ERR(bh);
1396 if (!bh) {
1397 WARN_ON_ONCE(1);
1398 EXT4_ERROR_INODE(ea_inode,
1399 "ext4_getblk() return bh = NULL");
1400 return -EFSCORRUPTED;
1401 }
1402 ret = ext4_journal_get_write_access(handle, ea_inode->i_sb, bh,
1403 EXT4_JTR_NONE);
1404 if (ret)
1405 goto out;
1406
1407 memcpy(bh->b_data, buf, csize);
1408 set_buffer_uptodate(bh);
1409 ext4_handle_dirty_metadata(handle, ea_inode, bh);
1410
1411 buf += csize;
1412 wsize += csize;
1413 block += 1;
1414 }
1415
1416 inode_lock(ea_inode);
1417 i_size_write(ea_inode, wsize);
1418 ext4_update_i_disksize(ea_inode, wsize);
1419 inode_unlock(ea_inode);
1420
1421 ret2 = ext4_mark_inode_dirty(handle, ea_inode);
1422 if (unlikely(ret2 && !ret))
1423 ret = ret2;
1424
1425out:
1426 brelse(bh);
1427
1428 return ret;
1429}
1430
1431/*
1432 * Create an inode to store the value of a large EA.
1433 */
1434static struct inode *ext4_xattr_inode_create(handle_t *handle,
1435 struct inode *inode, u32 hash)
1436{
1437 struct inode *ea_inode = NULL;
1438 uid_t owner[2] = { i_uid_read(inode), i_gid_read(inode) };
1439 int err;
1440
1441 /*
1442 * Let the next inode be the goal, so we try and allocate the EA inode
1443 * in the same group, or nearby one.
1444 */
1445 ea_inode = ext4_new_inode(handle, inode->i_sb->s_root->d_inode,
1446 S_IFREG | 0600, NULL, inode->i_ino + 1, owner,
1447 EXT4_EA_INODE_FL);
1448 if (!IS_ERR(ea_inode)) {
1449 ea_inode->i_op = &ext4_file_inode_operations;
1450 ea_inode->i_fop = &ext4_file_operations;
1451 ext4_set_aops(ea_inode);
1452 ext4_xattr_inode_set_class(ea_inode);
1453 unlock_new_inode(ea_inode);
1454 ext4_xattr_inode_set_ref(ea_inode, 1);
1455 ext4_xattr_inode_set_hash(ea_inode, hash);
1456 err = ext4_mark_inode_dirty(handle, ea_inode);
1457 if (!err)
1458 err = ext4_inode_attach_jinode(ea_inode);
1459 if (err) {
1460 if (ext4_xattr_inode_dec_ref(handle, ea_inode))
1461 ext4_warning_inode(ea_inode,
1462 "cleanup dec ref error %d", err);
1463 iput(ea_inode);
1464 return ERR_PTR(err);
1465 }
1466
1467 /*
1468 * Xattr inodes are shared therefore quota charging is performed
1469 * at a higher level.
1470 */
1471 dquot_free_inode(ea_inode);
1472 dquot_drop(ea_inode);
1473 inode_lock(ea_inode);
1474 ea_inode->i_flags |= S_NOQUOTA;
1475 inode_unlock(ea_inode);
1476 }
1477
1478 return ea_inode;
1479}
1480
1481static struct inode *
1482ext4_xattr_inode_cache_find(struct inode *inode, const void *value,
1483 size_t value_len, u32 hash)
1484{
1485 struct inode *ea_inode;
1486 struct mb_cache_entry *ce;
1487 struct mb_cache *ea_inode_cache = EA_INODE_CACHE(inode);
1488 void *ea_data;
1489
1490 if (!ea_inode_cache)
1491 return NULL;
1492
1493 ce = mb_cache_entry_find_first(ea_inode_cache, hash);
1494 if (!ce)
1495 return NULL;
1496
1497 WARN_ON_ONCE(ext4_handle_valid(journal_current_handle()) &&
1498 !(current->flags & PF_MEMALLOC_NOFS));
1499
1500 ea_data = kvmalloc(value_len, GFP_KERNEL);
1501 if (!ea_data) {
1502 mb_cache_entry_put(ea_inode_cache, ce);
1503 return NULL;
1504 }
1505
1506 while (ce) {
1507 ea_inode = ext4_iget(inode->i_sb, ce->e_value,
1508 EXT4_IGET_NORMAL);
1509 if (!IS_ERR(ea_inode) &&
1510 !is_bad_inode(ea_inode) &&
1511 (EXT4_I(ea_inode)->i_flags & EXT4_EA_INODE_FL) &&
1512 i_size_read(ea_inode) == value_len &&
1513 !ext4_xattr_inode_read(ea_inode, ea_data, value_len) &&
1514 !ext4_xattr_inode_verify_hashes(ea_inode, NULL, ea_data,
1515 value_len) &&
1516 !memcmp(value, ea_data, value_len)) {
1517 mb_cache_entry_touch(ea_inode_cache, ce);
1518 mb_cache_entry_put(ea_inode_cache, ce);
1519 kvfree(ea_data);
1520 return ea_inode;
1521 }
1522
1523 if (!IS_ERR(ea_inode))
1524 iput(ea_inode);
1525 ce = mb_cache_entry_find_next(ea_inode_cache, ce);
1526 }
1527 kvfree(ea_data);
1528 return NULL;
1529}
1530
1531/*
1532 * Add value of the EA in an inode.
1533 */
1534static int ext4_xattr_inode_lookup_create(handle_t *handle, struct inode *inode,
1535 const void *value, size_t value_len,
1536 struct inode **ret_inode)
1537{
1538 struct inode *ea_inode;
1539 u32 hash;
1540 int err;
1541
1542 hash = ext4_xattr_inode_hash(EXT4_SB(inode->i_sb), value, value_len);
1543 ea_inode = ext4_xattr_inode_cache_find(inode, value, value_len, hash);
1544 if (ea_inode) {
1545 err = ext4_xattr_inode_inc_ref(handle, ea_inode);
1546 if (err) {
1547 iput(ea_inode);
1548 return err;
1549 }
1550
1551 *ret_inode = ea_inode;
1552 return 0;
1553 }
1554
1555 /* Create an inode for the EA value */
1556 ea_inode = ext4_xattr_inode_create(handle, inode, hash);
1557 if (IS_ERR(ea_inode))
1558 return PTR_ERR(ea_inode);
1559
1560 err = ext4_xattr_inode_write(handle, ea_inode, value, value_len);
1561 if (err) {
1562 if (ext4_xattr_inode_dec_ref(handle, ea_inode))
1563 ext4_warning_inode(ea_inode, "cleanup dec ref error %d", err);
1564 iput(ea_inode);
1565 return err;
1566 }
1567
1568 if (EA_INODE_CACHE(inode))
1569 mb_cache_entry_create(EA_INODE_CACHE(inode), GFP_NOFS, hash,
1570 ea_inode->i_ino, true /* reusable */);
1571
1572 *ret_inode = ea_inode;
1573 return 0;
1574}
1575
1576/*
1577 * Reserve min(block_size/8, 1024) bytes for xattr entries/names if ea_inode
1578 * feature is enabled.
1579 */
1580#define EXT4_XATTR_BLOCK_RESERVE(inode) min(i_blocksize(inode)/8, 1024U)
1581
1582static int ext4_xattr_set_entry(struct ext4_xattr_info *i,
1583 struct ext4_xattr_search *s,
1584 handle_t *handle, struct inode *inode,
1585 bool is_block)
1586{
1587 struct ext4_xattr_entry *last, *next;
1588 struct ext4_xattr_entry *here = s->here;
1589 size_t min_offs = s->end - s->base, name_len = strlen(i->name);
1590 int in_inode = i->in_inode;
1591 struct inode *old_ea_inode = NULL;
1592 struct inode *new_ea_inode = NULL;
1593 size_t old_size, new_size;
1594 int ret;
1595
1596 /* Space used by old and new values. */
1597 old_size = (!s->not_found && !here->e_value_inum) ?
1598 EXT4_XATTR_SIZE(le32_to_cpu(here->e_value_size)) : 0;
1599 new_size = (i->value && !in_inode) ? EXT4_XATTR_SIZE(i->value_len) : 0;
1600
1601 /*
1602 * Optimization for the simple case when old and new values have the
1603 * same padded sizes. Not applicable if external inodes are involved.
1604 */
1605 if (new_size && new_size == old_size) {
1606 size_t offs = le16_to_cpu(here->e_value_offs);
1607 void *val = s->base + offs;
1608
1609 here->e_value_size = cpu_to_le32(i->value_len);
1610 if (i->value == EXT4_ZERO_XATTR_VALUE) {
1611 memset(val, 0, new_size);
1612 } else {
1613 memcpy(val, i->value, i->value_len);
1614 /* Clear padding bytes. */
1615 memset(val + i->value_len, 0, new_size - i->value_len);
1616 }
1617 goto update_hash;
1618 }
1619
1620 /* Compute min_offs and last. */
1621 last = s->first;
1622 for (; !IS_LAST_ENTRY(last); last = next) {
1623 next = EXT4_XATTR_NEXT(last);
1624 if ((void *)next >= s->end) {
1625 EXT4_ERROR_INODE(inode, "corrupted xattr entries");
1626 ret = -EFSCORRUPTED;
1627 goto out;
1628 }
1629 if (!last->e_value_inum && last->e_value_size) {
1630 size_t offs = le16_to_cpu(last->e_value_offs);
1631 if (offs < min_offs)
1632 min_offs = offs;
1633 }
1634 }
1635
1636 /* Check whether we have enough space. */
1637 if (i->value) {
1638 size_t free;
1639
1640 free = min_offs - ((void *)last - s->base) - sizeof(__u32);
1641 if (!s->not_found)
1642 free += EXT4_XATTR_LEN(name_len) + old_size;
1643
1644 if (free < EXT4_XATTR_LEN(name_len) + new_size) {
1645 ret = -ENOSPC;
1646 goto out;
1647 }
1648
1649 /*
1650 * If storing the value in an external inode is an option,
1651 * reserve space for xattr entries/names in the external
1652 * attribute block so that a long value does not occupy the
1653 * whole space and prevent further entries being added.
1654 */
1655 if (ext4_has_feature_ea_inode(inode->i_sb) &&
1656 new_size && is_block &&
1657 (min_offs + old_size - new_size) <
1658 EXT4_XATTR_BLOCK_RESERVE(inode)) {
1659 ret = -ENOSPC;
1660 goto out;
1661 }
1662 }
1663
1664 /*
1665 * Getting access to old and new ea inodes is subject to failures.
1666 * Finish that work before doing any modifications to the xattr data.
1667 */
1668 if (!s->not_found && here->e_value_inum) {
1669 ret = ext4_xattr_inode_iget(inode,
1670 le32_to_cpu(here->e_value_inum),
1671 le32_to_cpu(here->e_hash),
1672 &old_ea_inode);
1673 if (ret) {
1674 old_ea_inode = NULL;
1675 goto out;
1676 }
1677 }
1678 if (i->value && in_inode) {
1679 WARN_ON_ONCE(!i->value_len);
1680
1681 ret = ext4_xattr_inode_alloc_quota(inode, i->value_len);
1682 if (ret)
1683 goto out;
1684
1685 ret = ext4_xattr_inode_lookup_create(handle, inode, i->value,
1686 i->value_len,
1687 &new_ea_inode);
1688 if (ret) {
1689 new_ea_inode = NULL;
1690 ext4_xattr_inode_free_quota(inode, NULL, i->value_len);
1691 goto out;
1692 }
1693 }
1694
1695 if (old_ea_inode) {
1696 /* We are ready to release ref count on the old_ea_inode. */
1697 ret = ext4_xattr_inode_dec_ref(handle, old_ea_inode);
1698 if (ret) {
1699 /* Release newly required ref count on new_ea_inode. */
1700 if (new_ea_inode) {
1701 int err;
1702
1703 err = ext4_xattr_inode_dec_ref(handle,
1704 new_ea_inode);
1705 if (err)
1706 ext4_warning_inode(new_ea_inode,
1707 "dec ref new_ea_inode err=%d",
1708 err);
1709 ext4_xattr_inode_free_quota(inode, new_ea_inode,
1710 i->value_len);
1711 }
1712 goto out;
1713 }
1714
1715 ext4_xattr_inode_free_quota(inode, old_ea_inode,
1716 le32_to_cpu(here->e_value_size));
1717 }
1718
1719 /* No failures allowed past this point. */
1720
1721 if (!s->not_found && here->e_value_size && !here->e_value_inum) {
1722 /* Remove the old value. */
1723 void *first_val = s->base + min_offs;
1724 size_t offs = le16_to_cpu(here->e_value_offs);
1725 void *val = s->base + offs;
1726
1727 memmove(first_val + old_size, first_val, val - first_val);
1728 memset(first_val, 0, old_size);
1729 min_offs += old_size;
1730
1731 /* Adjust all value offsets. */
1732 last = s->first;
1733 while (!IS_LAST_ENTRY(last)) {
1734 size_t o = le16_to_cpu(last->e_value_offs);
1735
1736 if (!last->e_value_inum &&
1737 last->e_value_size && o < offs)
1738 last->e_value_offs = cpu_to_le16(o + old_size);
1739 last = EXT4_XATTR_NEXT(last);
1740 }
1741 }
1742
1743 if (!i->value) {
1744 /* Remove old name. */
1745 size_t size = EXT4_XATTR_LEN(name_len);
1746
1747 last = ENTRY((void *)last - size);
1748 memmove(here, (void *)here + size,
1749 (void *)last - (void *)here + sizeof(__u32));
1750 memset(last, 0, size);
1751 } else if (s->not_found) {
1752 /* Insert new name. */
1753 size_t size = EXT4_XATTR_LEN(name_len);
1754 size_t rest = (void *)last - (void *)here + sizeof(__u32);
1755
1756 memmove((void *)here + size, here, rest);
1757 memset(here, 0, size);
1758 here->e_name_index = i->name_index;
1759 here->e_name_len = name_len;
1760 memcpy(here->e_name, i->name, name_len);
1761 } else {
1762 /* This is an update, reset value info. */
1763 here->e_value_inum = 0;
1764 here->e_value_offs = 0;
1765 here->e_value_size = 0;
1766 }
1767
1768 if (i->value) {
1769 /* Insert new value. */
1770 if (in_inode) {
1771 here->e_value_inum = cpu_to_le32(new_ea_inode->i_ino);
1772 } else if (i->value_len) {
1773 void *val = s->base + min_offs - new_size;
1774
1775 here->e_value_offs = cpu_to_le16(min_offs - new_size);
1776 if (i->value == EXT4_ZERO_XATTR_VALUE) {
1777 memset(val, 0, new_size);
1778 } else {
1779 memcpy(val, i->value, i->value_len);
1780 /* Clear padding bytes. */
1781 memset(val + i->value_len, 0,
1782 new_size - i->value_len);
1783 }
1784 }
1785 here->e_value_size = cpu_to_le32(i->value_len);
1786 }
1787
1788update_hash:
1789 if (i->value) {
1790 __le32 hash = 0;
1791
1792 /* Entry hash calculation. */
1793 if (in_inode) {
1794 __le32 crc32c_hash;
1795
1796 /*
1797 * Feed crc32c hash instead of the raw value for entry
1798 * hash calculation. This is to avoid walking
1799 * potentially long value buffer again.
1800 */
1801 crc32c_hash = cpu_to_le32(
1802 ext4_xattr_inode_get_hash(new_ea_inode));
1803 hash = ext4_xattr_hash_entry(here->e_name,
1804 here->e_name_len,
1805 &crc32c_hash, 1);
1806 } else if (is_block) {
1807 __le32 *value = s->base + le16_to_cpu(
1808 here->e_value_offs);
1809
1810 hash = ext4_xattr_hash_entry(here->e_name,
1811 here->e_name_len, value,
1812 new_size >> 2);
1813 }
1814 here->e_hash = hash;
1815 }
1816
1817 if (is_block)
1818 ext4_xattr_rehash((struct ext4_xattr_header *)s->base);
1819
1820 ret = 0;
1821out:
1822 iput(old_ea_inode);
1823 iput(new_ea_inode);
1824 return ret;
1825}
1826
1827struct ext4_xattr_block_find {
1828 struct ext4_xattr_search s;
1829 struct buffer_head *bh;
1830};
1831
1832static int
1833ext4_xattr_block_find(struct inode *inode, struct ext4_xattr_info *i,
1834 struct ext4_xattr_block_find *bs)
1835{
1836 struct super_block *sb = inode->i_sb;
1837 int error;
1838
1839 ea_idebug(inode, "name=%d.%s, value=%p, value_len=%ld",
1840 i->name_index, i->name, i->value, (long)i->value_len);
1841
1842 if (EXT4_I(inode)->i_file_acl) {
1843 /* The inode already has an extended attribute block. */
1844 bs->bh = ext4_sb_bread(sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
1845 if (IS_ERR(bs->bh)) {
1846 error = PTR_ERR(bs->bh);
1847 bs->bh = NULL;
1848 return error;
1849 }
1850 ea_bdebug(bs->bh, "b_count=%d, refcount=%d",
1851 atomic_read(&(bs->bh->b_count)),
1852 le32_to_cpu(BHDR(bs->bh)->h_refcount));
1853 error = ext4_xattr_check_block(inode, bs->bh);
1854 if (error)
1855 return error;
1856 /* Find the named attribute. */
1857 bs->s.base = BHDR(bs->bh);
1858 bs->s.first = BFIRST(bs->bh);
1859 bs->s.end = bs->bh->b_data + bs->bh->b_size;
1860 bs->s.here = bs->s.first;
1861 error = xattr_find_entry(inode, &bs->s.here, bs->s.end,
1862 i->name_index, i->name, 1);
1863 if (error && error != -ENODATA)
1864 return error;
1865 bs->s.not_found = error;
1866 }
1867 return 0;
1868}
1869
1870static int
1871ext4_xattr_block_set(handle_t *handle, struct inode *inode,
1872 struct ext4_xattr_info *i,
1873 struct ext4_xattr_block_find *bs)
1874{
1875 struct super_block *sb = inode->i_sb;
1876 struct buffer_head *new_bh = NULL;
1877 struct ext4_xattr_search s_copy = bs->s;
1878 struct ext4_xattr_search *s = &s_copy;
1879 struct mb_cache_entry *ce = NULL;
1880 int error = 0;
1881 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
1882 struct inode *ea_inode = NULL, *tmp_inode;
1883 size_t old_ea_inode_quota = 0;
1884 unsigned int ea_ino;
1885
1886
1887#define header(x) ((struct ext4_xattr_header *)(x))
1888
1889 if (s->base) {
1890 int offset = (char *)s->here - bs->bh->b_data;
1891
1892 BUFFER_TRACE(bs->bh, "get_write_access");
1893 error = ext4_journal_get_write_access(handle, sb, bs->bh,
1894 EXT4_JTR_NONE);
1895 if (error)
1896 goto cleanup;
1897 lock_buffer(bs->bh);
1898
1899 if (header(s->base)->h_refcount == cpu_to_le32(1)) {
1900 __u32 hash = le32_to_cpu(BHDR(bs->bh)->h_hash);
1901
1902 /*
1903 * This must happen under buffer lock for
1904 * ext4_xattr_block_set() to reliably detect modified
1905 * block
1906 */
1907 if (ea_block_cache) {
1908 struct mb_cache_entry *oe;
1909
1910 oe = mb_cache_entry_delete_or_get(ea_block_cache,
1911 hash, bs->bh->b_blocknr);
1912 if (oe) {
1913 /*
1914 * Xattr block is getting reused. Leave
1915 * it alone.
1916 */
1917 mb_cache_entry_put(ea_block_cache, oe);
1918 goto clone_block;
1919 }
1920 }
1921 ea_bdebug(bs->bh, "modifying in-place");
1922 error = ext4_xattr_set_entry(i, s, handle, inode,
1923 true /* is_block */);
1924 ext4_xattr_block_csum_set(inode, bs->bh);
1925 unlock_buffer(bs->bh);
1926 if (error == -EFSCORRUPTED)
1927 goto bad_block;
1928 if (!error)
1929 error = ext4_handle_dirty_metadata(handle,
1930 inode,
1931 bs->bh);
1932 if (error)
1933 goto cleanup;
1934 goto inserted;
1935 }
1936clone_block:
1937 unlock_buffer(bs->bh);
1938 ea_bdebug(bs->bh, "cloning");
1939 s->base = kmemdup(BHDR(bs->bh), bs->bh->b_size, GFP_NOFS);
1940 error = -ENOMEM;
1941 if (s->base == NULL)
1942 goto cleanup;
1943 s->first = ENTRY(header(s->base)+1);
1944 header(s->base)->h_refcount = cpu_to_le32(1);
1945 s->here = ENTRY(s->base + offset);
1946 s->end = s->base + bs->bh->b_size;
1947
1948 /*
1949 * If existing entry points to an xattr inode, we need
1950 * to prevent ext4_xattr_set_entry() from decrementing
1951 * ref count on it because the reference belongs to the
1952 * original block. In this case, make the entry look
1953 * like it has an empty value.
1954 */
1955 if (!s->not_found && s->here->e_value_inum) {
1956 ea_ino = le32_to_cpu(s->here->e_value_inum);
1957 error = ext4_xattr_inode_iget(inode, ea_ino,
1958 le32_to_cpu(s->here->e_hash),
1959 &tmp_inode);
1960 if (error)
1961 goto cleanup;
1962
1963 if (!ext4_test_inode_state(tmp_inode,
1964 EXT4_STATE_LUSTRE_EA_INODE)) {
1965 /*
1966 * Defer quota free call for previous
1967 * inode until success is guaranteed.
1968 */
1969 old_ea_inode_quota = le32_to_cpu(
1970 s->here->e_value_size);
1971 }
1972 iput(tmp_inode);
1973
1974 s->here->e_value_inum = 0;
1975 s->here->e_value_size = 0;
1976 }
1977 } else {
1978 /* Allocate a buffer where we construct the new block. */
1979 s->base = kzalloc(sb->s_blocksize, GFP_NOFS);
1980 error = -ENOMEM;
1981 if (s->base == NULL)
1982 goto cleanup;
1983 header(s->base)->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
1984 header(s->base)->h_blocks = cpu_to_le32(1);
1985 header(s->base)->h_refcount = cpu_to_le32(1);
1986 s->first = ENTRY(header(s->base)+1);
1987 s->here = ENTRY(header(s->base)+1);
1988 s->end = s->base + sb->s_blocksize;
1989 }
1990
1991 error = ext4_xattr_set_entry(i, s, handle, inode, true /* is_block */);
1992 if (error == -EFSCORRUPTED)
1993 goto bad_block;
1994 if (error)
1995 goto cleanup;
1996
1997 if (i->value && s->here->e_value_inum) {
1998 /*
1999 * A ref count on ea_inode has been taken as part of the call to
2000 * ext4_xattr_set_entry() above. We would like to drop this
2001 * extra ref but we have to wait until the xattr block is
2002 * initialized and has its own ref count on the ea_inode.
2003 */
2004 ea_ino = le32_to_cpu(s->here->e_value_inum);
2005 error = ext4_xattr_inode_iget(inode, ea_ino,
2006 le32_to_cpu(s->here->e_hash),
2007 &ea_inode);
2008 if (error) {
2009 ea_inode = NULL;
2010 goto cleanup;
2011 }
2012 }
2013
2014inserted:
2015 if (!IS_LAST_ENTRY(s->first)) {
2016 new_bh = ext4_xattr_block_cache_find(inode, header(s->base),
2017 &ce);
2018 if (new_bh) {
2019 /* We found an identical block in the cache. */
2020 if (new_bh == bs->bh)
2021 ea_bdebug(new_bh, "keeping");
2022 else {
2023 u32 ref;
2024
2025 WARN_ON_ONCE(dquot_initialize_needed(inode));
2026
2027 /* The old block is released after updating
2028 the inode. */
2029 error = dquot_alloc_block(inode,
2030 EXT4_C2B(EXT4_SB(sb), 1));
2031 if (error)
2032 goto cleanup;
2033 BUFFER_TRACE(new_bh, "get_write_access");
2034 error = ext4_journal_get_write_access(
2035 handle, sb, new_bh,
2036 EXT4_JTR_NONE);
2037 if (error)
2038 goto cleanup_dquot;
2039 lock_buffer(new_bh);
2040 /*
2041 * We have to be careful about races with
2042 * adding references to xattr block. Once we
2043 * hold buffer lock xattr block's state is
2044 * stable so we can check the additional
2045 * reference fits.
2046 */
2047 ref = le32_to_cpu(BHDR(new_bh)->h_refcount) + 1;
2048 if (ref > EXT4_XATTR_REFCOUNT_MAX) {
2049 /*
2050 * Undo everything and check mbcache
2051 * again.
2052 */
2053 unlock_buffer(new_bh);
2054 dquot_free_block(inode,
2055 EXT4_C2B(EXT4_SB(sb),
2056 1));
2057 brelse(new_bh);
2058 mb_cache_entry_put(ea_block_cache, ce);
2059 ce = NULL;
2060 new_bh = NULL;
2061 goto inserted;
2062 }
2063 BHDR(new_bh)->h_refcount = cpu_to_le32(ref);
2064 if (ref == EXT4_XATTR_REFCOUNT_MAX)
2065 clear_bit(MBE_REUSABLE_B, &ce->e_flags);
2066 ea_bdebug(new_bh, "reusing; refcount now=%d",
2067 ref);
2068 ext4_xattr_block_csum_set(inode, new_bh);
2069 unlock_buffer(new_bh);
2070 error = ext4_handle_dirty_metadata(handle,
2071 inode,
2072 new_bh);
2073 if (error)
2074 goto cleanup_dquot;
2075 }
2076 mb_cache_entry_touch(ea_block_cache, ce);
2077 mb_cache_entry_put(ea_block_cache, ce);
2078 ce = NULL;
2079 } else if (bs->bh && s->base == bs->bh->b_data) {
2080 /* We were modifying this block in-place. */
2081 ea_bdebug(bs->bh, "keeping this block");
2082 ext4_xattr_block_cache_insert(ea_block_cache, bs->bh);
2083 new_bh = bs->bh;
2084 get_bh(new_bh);
2085 } else {
2086 /* We need to allocate a new block */
2087 ext4_fsblk_t goal, block;
2088
2089 WARN_ON_ONCE(dquot_initialize_needed(inode));
2090
2091 goal = ext4_group_first_block_no(sb,
2092 EXT4_I(inode)->i_block_group);
2093 block = ext4_new_meta_blocks(handle, inode, goal, 0,
2094 NULL, &error);
2095 if (error)
2096 goto cleanup;
2097
2098 ea_idebug(inode, "creating block %llu",
2099 (unsigned long long)block);
2100
2101 new_bh = sb_getblk(sb, block);
2102 if (unlikely(!new_bh)) {
2103 error = -ENOMEM;
2104getblk_failed:
2105 ext4_free_blocks(handle, inode, NULL, block, 1,
2106 EXT4_FREE_BLOCKS_METADATA);
2107 goto cleanup;
2108 }
2109 error = ext4_xattr_inode_inc_ref_all(handle, inode,
2110 ENTRY(header(s->base)+1));
2111 if (error)
2112 goto getblk_failed;
2113 if (ea_inode) {
2114 /* Drop the extra ref on ea_inode. */
2115 error = ext4_xattr_inode_dec_ref(handle,
2116 ea_inode);
2117 if (error)
2118 ext4_warning_inode(ea_inode,
2119 "dec ref error=%d",
2120 error);
2121 iput(ea_inode);
2122 ea_inode = NULL;
2123 }
2124
2125 lock_buffer(new_bh);
2126 error = ext4_journal_get_create_access(handle, sb,
2127 new_bh, EXT4_JTR_NONE);
2128 if (error) {
2129 unlock_buffer(new_bh);
2130 error = -EIO;
2131 goto getblk_failed;
2132 }
2133 memcpy(new_bh->b_data, s->base, new_bh->b_size);
2134 ext4_xattr_block_csum_set(inode, new_bh);
2135 set_buffer_uptodate(new_bh);
2136 unlock_buffer(new_bh);
2137 ext4_xattr_block_cache_insert(ea_block_cache, new_bh);
2138 error = ext4_handle_dirty_metadata(handle, inode,
2139 new_bh);
2140 if (error)
2141 goto cleanup;
2142 }
2143 }
2144
2145 if (old_ea_inode_quota)
2146 ext4_xattr_inode_free_quota(inode, NULL, old_ea_inode_quota);
2147
2148 /* Update the inode. */
2149 EXT4_I(inode)->i_file_acl = new_bh ? new_bh->b_blocknr : 0;
2150
2151 /* Drop the previous xattr block. */
2152 if (bs->bh && bs->bh != new_bh) {
2153 struct ext4_xattr_inode_array *ea_inode_array = NULL;
2154
2155 ext4_xattr_release_block(handle, inode, bs->bh,
2156 &ea_inode_array,
2157 0 /* extra_credits */);
2158 ext4_xattr_inode_array_free(ea_inode_array);
2159 }
2160 error = 0;
2161
2162cleanup:
2163 if (ea_inode) {
2164 int error2;
2165
2166 error2 = ext4_xattr_inode_dec_ref(handle, ea_inode);
2167 if (error2)
2168 ext4_warning_inode(ea_inode, "dec ref error=%d",
2169 error2);
2170
2171 /* If there was an error, revert the quota charge. */
2172 if (error)
2173 ext4_xattr_inode_free_quota(inode, ea_inode,
2174 i_size_read(ea_inode));
2175 iput(ea_inode);
2176 }
2177 if (ce)
2178 mb_cache_entry_put(ea_block_cache, ce);
2179 brelse(new_bh);
2180 if (!(bs->bh && s->base == bs->bh->b_data))
2181 kfree(s->base);
2182
2183 return error;
2184
2185cleanup_dquot:
2186 dquot_free_block(inode, EXT4_C2B(EXT4_SB(sb), 1));
2187 goto cleanup;
2188
2189bad_block:
2190 EXT4_ERROR_INODE(inode, "bad block %llu",
2191 EXT4_I(inode)->i_file_acl);
2192 goto cleanup;
2193
2194#undef header
2195}
2196
2197int ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i,
2198 struct ext4_xattr_ibody_find *is)
2199{
2200 struct ext4_xattr_ibody_header *header;
2201 struct ext4_inode *raw_inode;
2202 int error;
2203
2204 if (!EXT4_INODE_HAS_XATTR_SPACE(inode))
2205 return 0;
2206
2207 raw_inode = ext4_raw_inode(&is->iloc);
2208 header = IHDR(inode, raw_inode);
2209 is->s.base = is->s.first = IFIRST(header);
2210 is->s.here = is->s.first;
2211 is->s.end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
2212 if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
2213 error = xattr_check_inode(inode, header, is->s.end);
2214 if (error)
2215 return error;
2216 /* Find the named attribute. */
2217 error = xattr_find_entry(inode, &is->s.here, is->s.end,
2218 i->name_index, i->name, 0);
2219 if (error && error != -ENODATA)
2220 return error;
2221 is->s.not_found = error;
2222 }
2223 return 0;
2224}
2225
2226int ext4_xattr_ibody_set(handle_t *handle, struct inode *inode,
2227 struct ext4_xattr_info *i,
2228 struct ext4_xattr_ibody_find *is)
2229{
2230 struct ext4_xattr_ibody_header *header;
2231 struct ext4_xattr_search *s = &is->s;
2232 int error;
2233
2234 if (!EXT4_INODE_HAS_XATTR_SPACE(inode))
2235 return -ENOSPC;
2236
2237 error = ext4_xattr_set_entry(i, s, handle, inode, false /* is_block */);
2238 if (error)
2239 return error;
2240 header = IHDR(inode, ext4_raw_inode(&is->iloc));
2241 if (!IS_LAST_ENTRY(s->first)) {
2242 header->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
2243 ext4_set_inode_state(inode, EXT4_STATE_XATTR);
2244 } else {
2245 header->h_magic = cpu_to_le32(0);
2246 ext4_clear_inode_state(inode, EXT4_STATE_XATTR);
2247 }
2248 return 0;
2249}
2250
2251static int ext4_xattr_value_same(struct ext4_xattr_search *s,
2252 struct ext4_xattr_info *i)
2253{
2254 void *value;
2255
2256 /* When e_value_inum is set the value is stored externally. */
2257 if (s->here->e_value_inum)
2258 return 0;
2259 if (le32_to_cpu(s->here->e_value_size) != i->value_len)
2260 return 0;
2261 value = ((void *)s->base) + le16_to_cpu(s->here->e_value_offs);
2262 return !memcmp(value, i->value, i->value_len);
2263}
2264
2265static struct buffer_head *ext4_xattr_get_block(struct inode *inode)
2266{
2267 struct buffer_head *bh;
2268 int error;
2269
2270 if (!EXT4_I(inode)->i_file_acl)
2271 return NULL;
2272 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
2273 if (IS_ERR(bh))
2274 return bh;
2275 error = ext4_xattr_check_block(inode, bh);
2276 if (error) {
2277 brelse(bh);
2278 return ERR_PTR(error);
2279 }
2280 return bh;
2281}
2282
2283/*
2284 * ext4_xattr_set_handle()
2285 *
2286 * Create, replace or remove an extended attribute for this inode. Value
2287 * is NULL to remove an existing extended attribute, and non-NULL to
2288 * either replace an existing extended attribute, or create a new extended
2289 * attribute. The flags XATTR_REPLACE and XATTR_CREATE
2290 * specify that an extended attribute must exist and must not exist
2291 * previous to the call, respectively.
2292 *
2293 * Returns 0, or a negative error number on failure.
2294 */
2295int
2296ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
2297 const char *name, const void *value, size_t value_len,
2298 int flags)
2299{
2300 struct ext4_xattr_info i = {
2301 .name_index = name_index,
2302 .name = name,
2303 .value = value,
2304 .value_len = value_len,
2305 .in_inode = 0,
2306 };
2307 struct ext4_xattr_ibody_find is = {
2308 .s = { .not_found = -ENODATA, },
2309 };
2310 struct ext4_xattr_block_find bs = {
2311 .s = { .not_found = -ENODATA, },
2312 };
2313 int no_expand;
2314 int error;
2315
2316 if (!name)
2317 return -EINVAL;
2318 if (strlen(name) > 255)
2319 return -ERANGE;
2320
2321 ext4_write_lock_xattr(inode, &no_expand);
2322
2323 /* Check journal credits under write lock. */
2324 if (ext4_handle_valid(handle)) {
2325 struct buffer_head *bh;
2326 int credits;
2327
2328 bh = ext4_xattr_get_block(inode);
2329 if (IS_ERR(bh)) {
2330 error = PTR_ERR(bh);
2331 goto cleanup;
2332 }
2333
2334 credits = __ext4_xattr_set_credits(inode->i_sb, inode, bh,
2335 value_len,
2336 flags & XATTR_CREATE);
2337 brelse(bh);
2338
2339 if (jbd2_handle_buffer_credits(handle) < credits) {
2340 error = -ENOSPC;
2341 goto cleanup;
2342 }
2343 WARN_ON_ONCE(!(current->flags & PF_MEMALLOC_NOFS));
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;
2393retry_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 brelse(bs.bh);
2401 bs.bh = NULL;
2402 error = ext4_xattr_block_find(inode, &i, &bs);
2403 if (error)
2404 goto cleanup;
2405 }
2406 error = ext4_xattr_block_set(handle, inode, &i, &bs);
2407 if (!error && !is.s.not_found) {
2408 i.value = NULL;
2409 error = ext4_xattr_ibody_set(handle, inode, &i,
2410 &is);
2411 } else if (error == -ENOSPC) {
2412 /*
2413 * Xattr does not fit in the block, store at
2414 * external inode if possible.
2415 */
2416 if (ext4_has_feature_ea_inode(inode->i_sb) &&
2417 i.value_len && !i.in_inode) {
2418 i.in_inode = 1;
2419 goto retry_inode;
2420 }
2421 }
2422 }
2423 }
2424 if (!error) {
2425 ext4_xattr_update_super_block(handle, inode->i_sb);
2426 inode->i_ctime = current_time(inode);
2427 inode_inc_iversion(inode);
2428 if (!value)
2429 no_expand = 0;
2430 error = ext4_mark_iloc_dirty(handle, inode, &is.iloc);
2431 /*
2432 * The bh is consumed by ext4_mark_iloc_dirty, even with
2433 * error != 0.
2434 */
2435 is.iloc.bh = NULL;
2436 if (IS_SYNC(inode))
2437 ext4_handle_sync(handle);
2438 }
2439 ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_XATTR, handle);
2440
2441cleanup:
2442 brelse(is.iloc.bh);
2443 brelse(bs.bh);
2444 ext4_write_unlock_xattr(inode, &no_expand);
2445 return error;
2446}
2447
2448int ext4_xattr_set_credits(struct inode *inode, size_t value_len,
2449 bool is_create, int *credits)
2450{
2451 struct buffer_head *bh;
2452 int err;
2453
2454 *credits = 0;
2455
2456 if (!EXT4_SB(inode->i_sb)->s_journal)
2457 return 0;
2458
2459 down_read(&EXT4_I(inode)->xattr_sem);
2460
2461 bh = ext4_xattr_get_block(inode);
2462 if (IS_ERR(bh)) {
2463 err = PTR_ERR(bh);
2464 } else {
2465 *credits = __ext4_xattr_set_credits(inode->i_sb, inode, bh,
2466 value_len, is_create);
2467 brelse(bh);
2468 err = 0;
2469 }
2470
2471 up_read(&EXT4_I(inode)->xattr_sem);
2472 return err;
2473}
2474
2475/*
2476 * ext4_xattr_set()
2477 *
2478 * Like ext4_xattr_set_handle, but start from an inode. This extended
2479 * attribute modification is a filesystem transaction by itself.
2480 *
2481 * Returns 0, or a negative error number on failure.
2482 */
2483int
2484ext4_xattr_set(struct inode *inode, int name_index, const char *name,
2485 const void *value, size_t value_len, int flags)
2486{
2487 handle_t *handle;
2488 struct super_block *sb = inode->i_sb;
2489 int error, retries = 0;
2490 int credits;
2491
2492 error = dquot_initialize(inode);
2493 if (error)
2494 return error;
2495
2496retry:
2497 error = ext4_xattr_set_credits(inode, value_len, flags & XATTR_CREATE,
2498 &credits);
2499 if (error)
2500 return error;
2501
2502 handle = ext4_journal_start(inode, EXT4_HT_XATTR, credits);
2503 if (IS_ERR(handle)) {
2504 error = PTR_ERR(handle);
2505 } else {
2506 int error2;
2507
2508 error = ext4_xattr_set_handle(handle, inode, name_index, name,
2509 value, value_len, flags);
2510 error2 = ext4_journal_stop(handle);
2511 if (error == -ENOSPC &&
2512 ext4_should_retry_alloc(sb, &retries))
2513 goto retry;
2514 if (error == 0)
2515 error = error2;
2516 }
2517 ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_XATTR, NULL);
2518
2519 return error;
2520}
2521
2522/*
2523 * Shift the EA entries in the inode to create space for the increased
2524 * i_extra_isize.
2525 */
2526static void ext4_xattr_shift_entries(struct ext4_xattr_entry *entry,
2527 int value_offs_shift, void *to,
2528 void *from, size_t n)
2529{
2530 struct ext4_xattr_entry *last = entry;
2531 int new_offs;
2532
2533 /* We always shift xattr headers further thus offsets get lower */
2534 BUG_ON(value_offs_shift > 0);
2535
2536 /* Adjust the value offsets of the entries */
2537 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
2538 if (!last->e_value_inum && last->e_value_size) {
2539 new_offs = le16_to_cpu(last->e_value_offs) +
2540 value_offs_shift;
2541 last->e_value_offs = cpu_to_le16(new_offs);
2542 }
2543 }
2544 /* Shift the entries by n bytes */
2545 memmove(to, from, n);
2546}
2547
2548/*
2549 * Move xattr pointed to by 'entry' from inode into external xattr block
2550 */
2551static int ext4_xattr_move_to_block(handle_t *handle, struct inode *inode,
2552 struct ext4_inode *raw_inode,
2553 struct ext4_xattr_entry *entry)
2554{
2555 struct ext4_xattr_ibody_find *is = NULL;
2556 struct ext4_xattr_block_find *bs = NULL;
2557 char *buffer = NULL, *b_entry_name = NULL;
2558 size_t value_size = le32_to_cpu(entry->e_value_size);
2559 struct ext4_xattr_info i = {
2560 .value = NULL,
2561 .value_len = 0,
2562 .name_index = entry->e_name_index,
2563 .in_inode = !!entry->e_value_inum,
2564 };
2565 struct ext4_xattr_ibody_header *header = IHDR(inode, raw_inode);
2566 int error;
2567
2568 is = kzalloc(sizeof(struct ext4_xattr_ibody_find), GFP_NOFS);
2569 bs = kzalloc(sizeof(struct ext4_xattr_block_find), GFP_NOFS);
2570 buffer = kvmalloc(value_size, GFP_NOFS);
2571 b_entry_name = kmalloc(entry->e_name_len + 1, GFP_NOFS);
2572 if (!is || !bs || !buffer || !b_entry_name) {
2573 error = -ENOMEM;
2574 goto out;
2575 }
2576
2577 is->s.not_found = -ENODATA;
2578 bs->s.not_found = -ENODATA;
2579 is->iloc.bh = NULL;
2580 bs->bh = NULL;
2581
2582 /* Save the entry name and the entry value */
2583 if (entry->e_value_inum) {
2584 error = ext4_xattr_inode_get(inode, entry, buffer, value_size);
2585 if (error)
2586 goto out;
2587 } else {
2588 size_t value_offs = le16_to_cpu(entry->e_value_offs);
2589 memcpy(buffer, (void *)IFIRST(header) + value_offs, value_size);
2590 }
2591
2592 memcpy(b_entry_name, entry->e_name, entry->e_name_len);
2593 b_entry_name[entry->e_name_len] = '\0';
2594 i.name = b_entry_name;
2595
2596 error = ext4_get_inode_loc(inode, &is->iloc);
2597 if (error)
2598 goto out;
2599
2600 error = ext4_xattr_ibody_find(inode, &i, is);
2601 if (error)
2602 goto out;
2603
2604 /* Remove the chosen entry from the inode */
2605 error = ext4_xattr_ibody_set(handle, inode, &i, is);
2606 if (error)
2607 goto out;
2608
2609 i.value = buffer;
2610 i.value_len = value_size;
2611 error = ext4_xattr_block_find(inode, &i, bs);
2612 if (error)
2613 goto out;
2614
2615 /* Add entry which was removed from the inode into the block */
2616 error = ext4_xattr_block_set(handle, inode, &i, bs);
2617 if (error)
2618 goto out;
2619 error = 0;
2620out:
2621 kfree(b_entry_name);
2622 kvfree(buffer);
2623 if (is)
2624 brelse(is->iloc.bh);
2625 if (bs)
2626 brelse(bs->bh);
2627 kfree(is);
2628 kfree(bs);
2629
2630 return error;
2631}
2632
2633static int ext4_xattr_make_inode_space(handle_t *handle, struct inode *inode,
2634 struct ext4_inode *raw_inode,
2635 int isize_diff, size_t ifree,
2636 size_t bfree, int *total_ino)
2637{
2638 struct ext4_xattr_ibody_header *header = IHDR(inode, raw_inode);
2639 struct ext4_xattr_entry *small_entry;
2640 struct ext4_xattr_entry *entry;
2641 struct ext4_xattr_entry *last;
2642 unsigned int entry_size; /* EA entry size */
2643 unsigned int total_size; /* EA entry size + value size */
2644 unsigned int min_total_size;
2645 int error;
2646
2647 while (isize_diff > ifree) {
2648 entry = NULL;
2649 small_entry = NULL;
2650 min_total_size = ~0U;
2651 last = IFIRST(header);
2652 /* Find the entry best suited to be pushed into EA block */
2653 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
2654 /* never move system.data out of the inode */
2655 if ((last->e_name_len == 4) &&
2656 (last->e_name_index == EXT4_XATTR_INDEX_SYSTEM) &&
2657 !memcmp(last->e_name, "data", 4))
2658 continue;
2659 total_size = EXT4_XATTR_LEN(last->e_name_len);
2660 if (!last->e_value_inum)
2661 total_size += EXT4_XATTR_SIZE(
2662 le32_to_cpu(last->e_value_size));
2663 if (total_size <= bfree &&
2664 total_size < min_total_size) {
2665 if (total_size + ifree < isize_diff) {
2666 small_entry = last;
2667 } else {
2668 entry = last;
2669 min_total_size = total_size;
2670 }
2671 }
2672 }
2673
2674 if (entry == NULL) {
2675 if (small_entry == NULL)
2676 return -ENOSPC;
2677 entry = small_entry;
2678 }
2679
2680 entry_size = EXT4_XATTR_LEN(entry->e_name_len);
2681 total_size = entry_size;
2682 if (!entry->e_value_inum)
2683 total_size += EXT4_XATTR_SIZE(
2684 le32_to_cpu(entry->e_value_size));
2685 error = ext4_xattr_move_to_block(handle, inode, raw_inode,
2686 entry);
2687 if (error)
2688 return error;
2689
2690 *total_ino -= entry_size;
2691 ifree += total_size;
2692 bfree -= total_size;
2693 }
2694
2695 return 0;
2696}
2697
2698/*
2699 * Expand an inode by new_extra_isize bytes when EAs are present.
2700 * Returns 0 on success or negative error number on failure.
2701 */
2702int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
2703 struct ext4_inode *raw_inode, handle_t *handle)
2704{
2705 struct ext4_xattr_ibody_header *header;
2706 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2707 static unsigned int mnt_count;
2708 size_t min_offs;
2709 size_t ifree, bfree;
2710 int total_ino;
2711 void *base, *end;
2712 int error = 0, tried_min_extra_isize = 0;
2713 int s_min_extra_isize = le16_to_cpu(sbi->s_es->s_min_extra_isize);
2714 int isize_diff; /* How much do we need to grow i_extra_isize */
2715
2716retry:
2717 isize_diff = new_extra_isize - EXT4_I(inode)->i_extra_isize;
2718 if (EXT4_I(inode)->i_extra_isize >= new_extra_isize)
2719 return 0;
2720
2721 header = IHDR(inode, raw_inode);
2722
2723 /*
2724 * Check if enough free space is available in the inode to shift the
2725 * entries ahead by new_extra_isize.
2726 */
2727
2728 base = IFIRST(header);
2729 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
2730 min_offs = end - base;
2731 total_ino = sizeof(struct ext4_xattr_ibody_header) + sizeof(u32);
2732
2733 error = xattr_check_inode(inode, header, end);
2734 if (error)
2735 goto cleanup;
2736
2737 ifree = ext4_xattr_free_space(base, &min_offs, base, &total_ino);
2738 if (ifree >= isize_diff)
2739 goto shift;
2740
2741 /*
2742 * Enough free space isn't available in the inode, check if
2743 * EA block can hold new_extra_isize bytes.
2744 */
2745 if (EXT4_I(inode)->i_file_acl) {
2746 struct buffer_head *bh;
2747
2748 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
2749 if (IS_ERR(bh)) {
2750 error = PTR_ERR(bh);
2751 goto cleanup;
2752 }
2753 error = ext4_xattr_check_block(inode, bh);
2754 if (error) {
2755 brelse(bh);
2756 goto cleanup;
2757 }
2758 base = BHDR(bh);
2759 end = bh->b_data + bh->b_size;
2760 min_offs = end - base;
2761 bfree = ext4_xattr_free_space(BFIRST(bh), &min_offs, base,
2762 NULL);
2763 brelse(bh);
2764 if (bfree + ifree < isize_diff) {
2765 if (!tried_min_extra_isize && s_min_extra_isize) {
2766 tried_min_extra_isize++;
2767 new_extra_isize = s_min_extra_isize;
2768 goto retry;
2769 }
2770 error = -ENOSPC;
2771 goto cleanup;
2772 }
2773 } else {
2774 bfree = inode->i_sb->s_blocksize;
2775 }
2776
2777 error = ext4_xattr_make_inode_space(handle, inode, raw_inode,
2778 isize_diff, ifree, bfree,
2779 &total_ino);
2780 if (error) {
2781 if (error == -ENOSPC && !tried_min_extra_isize &&
2782 s_min_extra_isize) {
2783 tried_min_extra_isize++;
2784 new_extra_isize = s_min_extra_isize;
2785 goto retry;
2786 }
2787 goto cleanup;
2788 }
2789shift:
2790 /* Adjust the offsets and shift the remaining entries ahead */
2791 ext4_xattr_shift_entries(IFIRST(header), EXT4_I(inode)->i_extra_isize
2792 - new_extra_isize, (void *)raw_inode +
2793 EXT4_GOOD_OLD_INODE_SIZE + new_extra_isize,
2794 (void *)header, total_ino);
2795 EXT4_I(inode)->i_extra_isize = new_extra_isize;
2796
2797cleanup:
2798 if (error && (mnt_count != le16_to_cpu(sbi->s_es->s_mnt_count))) {
2799 ext4_warning(inode->i_sb, "Unable to expand inode %lu. Delete some EAs or run e2fsck.",
2800 inode->i_ino);
2801 mnt_count = le16_to_cpu(sbi->s_es->s_mnt_count);
2802 }
2803 return error;
2804}
2805
2806#define EIA_INCR 16 /* must be 2^n */
2807#define EIA_MASK (EIA_INCR - 1)
2808
2809/* Add the large xattr @inode into @ea_inode_array for deferred iput().
2810 * If @ea_inode_array is new or full it will be grown and the old
2811 * contents copied over.
2812 */
2813static int
2814ext4_expand_inode_array(struct ext4_xattr_inode_array **ea_inode_array,
2815 struct inode *inode)
2816{
2817 if (*ea_inode_array == NULL) {
2818 /*
2819 * Start with 15 inodes, so it fits into a power-of-two size.
2820 * If *ea_inode_array is NULL, this is essentially offsetof()
2821 */
2822 (*ea_inode_array) =
2823 kmalloc(offsetof(struct ext4_xattr_inode_array,
2824 inodes[EIA_MASK]),
2825 GFP_NOFS);
2826 if (*ea_inode_array == NULL)
2827 return -ENOMEM;
2828 (*ea_inode_array)->count = 0;
2829 } else if (((*ea_inode_array)->count & EIA_MASK) == EIA_MASK) {
2830 /* expand the array once all 15 + n * 16 slots are full */
2831 struct ext4_xattr_inode_array *new_array = NULL;
2832 int count = (*ea_inode_array)->count;
2833
2834 /* if new_array is NULL, this is essentially offsetof() */
2835 new_array = kmalloc(
2836 offsetof(struct ext4_xattr_inode_array,
2837 inodes[count + EIA_INCR]),
2838 GFP_NOFS);
2839 if (new_array == NULL)
2840 return -ENOMEM;
2841 memcpy(new_array, *ea_inode_array,
2842 offsetof(struct ext4_xattr_inode_array, inodes[count]));
2843 kfree(*ea_inode_array);
2844 *ea_inode_array = new_array;
2845 }
2846 (*ea_inode_array)->inodes[(*ea_inode_array)->count++] = inode;
2847 return 0;
2848}
2849
2850/*
2851 * ext4_xattr_delete_inode()
2852 *
2853 * Free extended attribute resources associated with this inode. Traverse
2854 * all entries and decrement reference on any xattr inodes associated with this
2855 * inode. This is called immediately before an inode is freed. We have exclusive
2856 * access to the inode. If an orphan inode is deleted it will also release its
2857 * references on xattr block and xattr inodes.
2858 */
2859int ext4_xattr_delete_inode(handle_t *handle, struct inode *inode,
2860 struct ext4_xattr_inode_array **ea_inode_array,
2861 int extra_credits)
2862{
2863 struct buffer_head *bh = NULL;
2864 struct ext4_xattr_ibody_header *header;
2865 struct ext4_iloc iloc = { .bh = NULL };
2866 struct ext4_xattr_entry *entry;
2867 struct inode *ea_inode;
2868 int error;
2869
2870 error = ext4_journal_ensure_credits(handle, extra_credits,
2871 ext4_free_metadata_revoke_credits(inode->i_sb, 1));
2872 if (error < 0) {
2873 EXT4_ERROR_INODE(inode, "ensure credits (error %d)", error);
2874 goto cleanup;
2875 }
2876
2877 if (ext4_has_feature_ea_inode(inode->i_sb) &&
2878 ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
2879
2880 error = ext4_get_inode_loc(inode, &iloc);
2881 if (error) {
2882 EXT4_ERROR_INODE(inode, "inode loc (error %d)", error);
2883 goto cleanup;
2884 }
2885
2886 error = ext4_journal_get_write_access(handle, inode->i_sb,
2887 iloc.bh, EXT4_JTR_NONE);
2888 if (error) {
2889 EXT4_ERROR_INODE(inode, "write access (error %d)",
2890 error);
2891 goto cleanup;
2892 }
2893
2894 header = IHDR(inode, ext4_raw_inode(&iloc));
2895 if (header->h_magic == cpu_to_le32(EXT4_XATTR_MAGIC))
2896 ext4_xattr_inode_dec_ref_all(handle, inode, iloc.bh,
2897 IFIRST(header),
2898 false /* block_csum */,
2899 ea_inode_array,
2900 extra_credits,
2901 false /* skip_quota */);
2902 }
2903
2904 if (EXT4_I(inode)->i_file_acl) {
2905 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
2906 if (IS_ERR(bh)) {
2907 error = PTR_ERR(bh);
2908 if (error == -EIO) {
2909 EXT4_ERROR_INODE_ERR(inode, EIO,
2910 "block %llu read error",
2911 EXT4_I(inode)->i_file_acl);
2912 }
2913 bh = NULL;
2914 goto cleanup;
2915 }
2916 error = ext4_xattr_check_block(inode, bh);
2917 if (error)
2918 goto cleanup;
2919
2920 if (ext4_has_feature_ea_inode(inode->i_sb)) {
2921 for (entry = BFIRST(bh); !IS_LAST_ENTRY(entry);
2922 entry = EXT4_XATTR_NEXT(entry)) {
2923 if (!entry->e_value_inum)
2924 continue;
2925 error = ext4_xattr_inode_iget(inode,
2926 le32_to_cpu(entry->e_value_inum),
2927 le32_to_cpu(entry->e_hash),
2928 &ea_inode);
2929 if (error)
2930 continue;
2931 ext4_xattr_inode_free_quota(inode, ea_inode,
2932 le32_to_cpu(entry->e_value_size));
2933 iput(ea_inode);
2934 }
2935
2936 }
2937
2938 ext4_xattr_release_block(handle, inode, bh, ea_inode_array,
2939 extra_credits);
2940 /*
2941 * Update i_file_acl value in the same transaction that releases
2942 * block.
2943 */
2944 EXT4_I(inode)->i_file_acl = 0;
2945 error = ext4_mark_inode_dirty(handle, inode);
2946 if (error) {
2947 EXT4_ERROR_INODE(inode, "mark inode dirty (error %d)",
2948 error);
2949 goto cleanup;
2950 }
2951 ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_XATTR, handle);
2952 }
2953 error = 0;
2954cleanup:
2955 brelse(iloc.bh);
2956 brelse(bh);
2957 return error;
2958}
2959
2960void ext4_xattr_inode_array_free(struct ext4_xattr_inode_array *ea_inode_array)
2961{
2962 int idx;
2963
2964 if (ea_inode_array == NULL)
2965 return;
2966
2967 for (idx = 0; idx < ea_inode_array->count; ++idx)
2968 iput(ea_inode_array->inodes[idx]);
2969 kfree(ea_inode_array);
2970}
2971
2972/*
2973 * ext4_xattr_block_cache_insert()
2974 *
2975 * Create a new entry in the extended attribute block cache, and insert
2976 * it unless such an entry is already in the cache.
2977 *
2978 * Returns 0, or a negative error number on failure.
2979 */
2980static void
2981ext4_xattr_block_cache_insert(struct mb_cache *ea_block_cache,
2982 struct buffer_head *bh)
2983{
2984 struct ext4_xattr_header *header = BHDR(bh);
2985 __u32 hash = le32_to_cpu(header->h_hash);
2986 int reusable = le32_to_cpu(header->h_refcount) <
2987 EXT4_XATTR_REFCOUNT_MAX;
2988 int error;
2989
2990 if (!ea_block_cache)
2991 return;
2992 error = mb_cache_entry_create(ea_block_cache, GFP_NOFS, hash,
2993 bh->b_blocknr, reusable);
2994 if (error) {
2995 if (error == -EBUSY)
2996 ea_bdebug(bh, "already in cache");
2997 } else
2998 ea_bdebug(bh, "inserting [%x]", (int)hash);
2999}
3000
3001/*
3002 * ext4_xattr_cmp()
3003 *
3004 * Compare two extended attribute blocks for equality.
3005 *
3006 * Returns 0 if the blocks are equal, 1 if they differ, and
3007 * a negative error number on errors.
3008 */
3009static int
3010ext4_xattr_cmp(struct ext4_xattr_header *header1,
3011 struct ext4_xattr_header *header2)
3012{
3013 struct ext4_xattr_entry *entry1, *entry2;
3014
3015 entry1 = ENTRY(header1+1);
3016 entry2 = ENTRY(header2+1);
3017 while (!IS_LAST_ENTRY(entry1)) {
3018 if (IS_LAST_ENTRY(entry2))
3019 return 1;
3020 if (entry1->e_hash != entry2->e_hash ||
3021 entry1->e_name_index != entry2->e_name_index ||
3022 entry1->e_name_len != entry2->e_name_len ||
3023 entry1->e_value_size != entry2->e_value_size ||
3024 entry1->e_value_inum != entry2->e_value_inum ||
3025 memcmp(entry1->e_name, entry2->e_name, entry1->e_name_len))
3026 return 1;
3027 if (!entry1->e_value_inum &&
3028 memcmp((char *)header1 + le16_to_cpu(entry1->e_value_offs),
3029 (char *)header2 + le16_to_cpu(entry2->e_value_offs),
3030 le32_to_cpu(entry1->e_value_size)))
3031 return 1;
3032
3033 entry1 = EXT4_XATTR_NEXT(entry1);
3034 entry2 = EXT4_XATTR_NEXT(entry2);
3035 }
3036 if (!IS_LAST_ENTRY(entry2))
3037 return 1;
3038 return 0;
3039}
3040
3041/*
3042 * ext4_xattr_block_cache_find()
3043 *
3044 * Find an identical extended attribute block.
3045 *
3046 * Returns a pointer to the block found, or NULL if such a block was
3047 * not found or an error occurred.
3048 */
3049static struct buffer_head *
3050ext4_xattr_block_cache_find(struct inode *inode,
3051 struct ext4_xattr_header *header,
3052 struct mb_cache_entry **pce)
3053{
3054 __u32 hash = le32_to_cpu(header->h_hash);
3055 struct mb_cache_entry *ce;
3056 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
3057
3058 if (!ea_block_cache)
3059 return NULL;
3060 if (!header->h_hash)
3061 return NULL; /* never share */
3062 ea_idebug(inode, "looking for cached blocks [%x]", (int)hash);
3063 ce = mb_cache_entry_find_first(ea_block_cache, hash);
3064 while (ce) {
3065 struct buffer_head *bh;
3066
3067 bh = ext4_sb_bread(inode->i_sb, ce->e_value, REQ_PRIO);
3068 if (IS_ERR(bh)) {
3069 if (PTR_ERR(bh) == -ENOMEM)
3070 return NULL;
3071 bh = NULL;
3072 EXT4_ERROR_INODE(inode, "block %lu read error",
3073 (unsigned long)ce->e_value);
3074 } else if (ext4_xattr_cmp(header, BHDR(bh)) == 0) {
3075 *pce = ce;
3076 return bh;
3077 }
3078 brelse(bh);
3079 ce = mb_cache_entry_find_next(ea_block_cache, ce);
3080 }
3081 return NULL;
3082}
3083
3084#define NAME_HASH_SHIFT 5
3085#define VALUE_HASH_SHIFT 16
3086
3087/*
3088 * ext4_xattr_hash_entry()
3089 *
3090 * Compute the hash of an extended attribute.
3091 */
3092static __le32 ext4_xattr_hash_entry(char *name, size_t name_len, __le32 *value,
3093 size_t value_count)
3094{
3095 __u32 hash = 0;
3096
3097 while (name_len--) {
3098 hash = (hash << NAME_HASH_SHIFT) ^
3099 (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^
3100 (unsigned char)*name++;
3101 }
3102 while (value_count--) {
3103 hash = (hash << VALUE_HASH_SHIFT) ^
3104 (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^
3105 le32_to_cpu(*value++);
3106 }
3107 return cpu_to_le32(hash);
3108}
3109
3110/*
3111 * ext4_xattr_hash_entry_signed()
3112 *
3113 * Compute the hash of an extended attribute incorrectly.
3114 */
3115static __le32 ext4_xattr_hash_entry_signed(char *name, size_t name_len, __le32 *value, size_t value_count)
3116{
3117 __u32 hash = 0;
3118
3119 while (name_len--) {
3120 hash = (hash << NAME_HASH_SHIFT) ^
3121 (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^
3122 (signed char)*name++;
3123 }
3124 while (value_count--) {
3125 hash = (hash << VALUE_HASH_SHIFT) ^
3126 (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^
3127 le32_to_cpu(*value++);
3128 }
3129 return cpu_to_le32(hash);
3130}
3131
3132#undef NAME_HASH_SHIFT
3133#undef VALUE_HASH_SHIFT
3134
3135#define BLOCK_HASH_SHIFT 16
3136
3137/*
3138 * ext4_xattr_rehash()
3139 *
3140 * Re-compute the extended attribute hash value after an entry has changed.
3141 */
3142static void ext4_xattr_rehash(struct ext4_xattr_header *header)
3143{
3144 struct ext4_xattr_entry *here;
3145 __u32 hash = 0;
3146
3147 here = ENTRY(header+1);
3148 while (!IS_LAST_ENTRY(here)) {
3149 if (!here->e_hash) {
3150 /* Block is not shared if an entry's hash value == 0 */
3151 hash = 0;
3152 break;
3153 }
3154 hash = (hash << BLOCK_HASH_SHIFT) ^
3155 (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^
3156 le32_to_cpu(here->e_hash);
3157 here = EXT4_XATTR_NEXT(here);
3158 }
3159 header->h_hash = cpu_to_le32(hash);
3160}
3161
3162#undef BLOCK_HASH_SHIFT
3163
3164#define HASH_BUCKET_BITS 10
3165
3166struct mb_cache *
3167ext4_xattr_create_cache(void)
3168{
3169 return mb_cache_create(HASH_BUCKET_BITS);
3170}
3171
3172void ext4_xattr_destroy_cache(struct mb_cache *cache)
3173{
3174 if (cache)
3175 mb_cache_destroy(cache);
3176}
3177
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
77static void ext4_xattr_block_cache_insert(struct mb_cache *,
78 struct buffer_head *);
79static struct buffer_head *
80ext4_xattr_block_cache_find(struct inode *, struct ext4_xattr_header *,
81 struct mb_cache_entry **);
82static __le32 ext4_xattr_hash_entry(char *name, size_t name_len, __le32 *value,
83 size_t value_count);
84static void ext4_xattr_rehash(struct ext4_xattr_header *);
85
86static 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
99const 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
119static int
120ext4_expand_inode_array(struct ext4_xattr_inode_array **ea_inode_array,
121 struct inode *inode);
122
123#ifdef CONFIG_LOCKDEP
124void ext4_xattr_inode_set_class(struct inode *ea_inode)
125{
126 lockdep_set_subclass(&ea_inode->i_rwsem, 1);
127}
128#endif
129
130static __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
151static 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
166static 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
174static inline const struct xattr_handler *
175ext4_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
184static int
185ext4_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
231static 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);
248errout:
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
262static 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));
272errout:
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
282static int
283xattr_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
311static u32
312ext4_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
317static 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
323static 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
329static u32 ext4_xattr_inode_get_hash(struct inode *ea_inode)
330{
331 return (u32)ea_inode->i_atime.tv_sec;
332}
333
334static 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 */
342static 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;
372put_bhs:
373 for (i = 0; i < bh_count; i++)
374 brelse(bhs[i]);
375free_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
383static 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;
434error:
435 iput(inode);
436 return err;
437}
438
439static int
440ext4_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 */
467static int
468ext4_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 }
508out:
509 iput(ea_inode);
510 return err;
511}
512
513static int
514ext4_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
568cleanup:
569 brelse(bh);
570 return error;
571}
572
573int
574ext4_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
623cleanup:
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 */
638int
639ext4_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
660static int
661ext4_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
690static int
691ext4_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);
715cleanup:
716 brelse(bh);
717 return error;
718}
719
720static int
721ext4_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
744cleanup:
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 */
761ssize_t
762ext4_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;
778errout:
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 */
787static 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
803int 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;
852out:
853 brelse(iloc.bh);
854 brelse(bh);
855 return ret;
856}
857
858static 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
868static 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
881static 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
892int __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
975static 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);
1037out:
1038 inode_unlock(ea_inode);
1039 return ret;
1040}
1041
1042static 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
1047static 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
1052static 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
1081cleanup:
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
1108static 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
1126static void
1127ext4_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 */
1222static void
1223ext4_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 }
1300out:
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 */
1309static 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 */
1327static 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
1338retry:
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
1396out:
1397 brelse(bh);
1398
1399 return ret;
1400}
1401
1402/*
1403 * Create an inode to store the value of a large EA.
1404 */
1405static 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
1449static struct inode *
1450ext4_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 */
1502static 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
1549static 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
1755update_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;
1788out:
1789 iput(old_ea_inode);
1790 iput(new_ea_inode);
1791 return ret;
1792}
1793
1794struct ext4_xattr_block_find {
1795 struct ext4_xattr_search s;
1796 struct buffer_head *bh;
1797};
1798
1799static int
1800ext4_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
1837static int
1838ext4_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
1970inserted:
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;
2073getblk_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
2130cleanup:
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
2153cleanup_dquot:
2154 dquot_free_block(inode, EXT4_C2B(EXT4_SB(sb), 1));
2155 goto cleanup;
2156
2157bad_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
2165int 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
2193int ext4_xattr_ibody_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
2217static int ext4_xattr_value_same(struct ext4_xattr_search *s,
2218 struct ext4_xattr_info *i)
2219{
2220 void *value;
2221
2222 /* When e_value_inum is set the value is stored externally. */
2223 if (s->here->e_value_inum)
2224 return 0;
2225 if (le32_to_cpu(s->here->e_value_size) != i->value_len)
2226 return 0;
2227 value = ((void *)s->base) + le16_to_cpu(s->here->e_value_offs);
2228 return !memcmp(value, i->value, i->value_len);
2229}
2230
2231static struct buffer_head *ext4_xattr_get_block(struct inode *inode)
2232{
2233 struct buffer_head *bh;
2234 int error;
2235
2236 if (!EXT4_I(inode)->i_file_acl)
2237 return NULL;
2238 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
2239 if (IS_ERR(bh))
2240 return bh;
2241 error = ext4_xattr_check_block(inode, bh);
2242 if (error) {
2243 brelse(bh);
2244 return ERR_PTR(error);
2245 }
2246 return bh;
2247}
2248
2249/*
2250 * ext4_xattr_set_handle()
2251 *
2252 * Create, replace or remove an extended attribute for this inode. Value
2253 * is NULL to remove an existing extended attribute, and non-NULL to
2254 * either replace an existing extended attribute, or create a new extended
2255 * attribute. The flags XATTR_REPLACE and XATTR_CREATE
2256 * specify that an extended attribute must exist and must not exist
2257 * previous to the call, respectively.
2258 *
2259 * Returns 0, or a negative error number on failure.
2260 */
2261int
2262ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
2263 const char *name, const void *value, size_t value_len,
2264 int flags)
2265{
2266 struct ext4_xattr_info i = {
2267 .name_index = name_index,
2268 .name = name,
2269 .value = value,
2270 .value_len = value_len,
2271 .in_inode = 0,
2272 };
2273 struct ext4_xattr_ibody_find is = {
2274 .s = { .not_found = -ENODATA, },
2275 };
2276 struct ext4_xattr_block_find bs = {
2277 .s = { .not_found = -ENODATA, },
2278 };
2279 int no_expand;
2280 int error;
2281
2282 if (!name)
2283 return -EINVAL;
2284 if (strlen(name) > 255)
2285 return -ERANGE;
2286
2287 ext4_write_lock_xattr(inode, &no_expand);
2288
2289 /* Check journal credits under write lock. */
2290 if (ext4_handle_valid(handle)) {
2291 struct buffer_head *bh;
2292 int credits;
2293
2294 bh = ext4_xattr_get_block(inode);
2295 if (IS_ERR(bh)) {
2296 error = PTR_ERR(bh);
2297 goto cleanup;
2298 }
2299
2300 credits = __ext4_xattr_set_credits(inode->i_sb, inode, bh,
2301 value_len,
2302 flags & XATTR_CREATE);
2303 brelse(bh);
2304
2305 if (jbd2_handle_buffer_credits(handle) < credits) {
2306 error = -ENOSPC;
2307 goto cleanup;
2308 }
2309 WARN_ON_ONCE(!(current->flags & PF_MEMALLOC_NOFS));
2310 }
2311
2312 error = ext4_reserve_inode_write(handle, inode, &is.iloc);
2313 if (error)
2314 goto cleanup;
2315
2316 if (ext4_test_inode_state(inode, EXT4_STATE_NEW)) {
2317 struct ext4_inode *raw_inode = ext4_raw_inode(&is.iloc);
2318 memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size);
2319 ext4_clear_inode_state(inode, EXT4_STATE_NEW);
2320 }
2321
2322 error = ext4_xattr_ibody_find(inode, &i, &is);
2323 if (error)
2324 goto cleanup;
2325 if (is.s.not_found)
2326 error = ext4_xattr_block_find(inode, &i, &bs);
2327 if (error)
2328 goto cleanup;
2329 if (is.s.not_found && bs.s.not_found) {
2330 error = -ENODATA;
2331 if (flags & XATTR_REPLACE)
2332 goto cleanup;
2333 error = 0;
2334 if (!value)
2335 goto cleanup;
2336 } else {
2337 error = -EEXIST;
2338 if (flags & XATTR_CREATE)
2339 goto cleanup;
2340 }
2341
2342 if (!value) {
2343 if (!is.s.not_found)
2344 error = ext4_xattr_ibody_set(handle, inode, &i, &is);
2345 else if (!bs.s.not_found)
2346 error = ext4_xattr_block_set(handle, inode, &i, &bs);
2347 } else {
2348 error = 0;
2349 /* Xattr value did not change? Save us some work and bail out */
2350 if (!is.s.not_found && ext4_xattr_value_same(&is.s, &i))
2351 goto cleanup;
2352 if (!bs.s.not_found && ext4_xattr_value_same(&bs.s, &i))
2353 goto cleanup;
2354
2355 if (ext4_has_feature_ea_inode(inode->i_sb) &&
2356 (EXT4_XATTR_SIZE(i.value_len) >
2357 EXT4_XATTR_MIN_LARGE_EA_SIZE(inode->i_sb->s_blocksize)))
2358 i.in_inode = 1;
2359retry_inode:
2360 error = ext4_xattr_ibody_set(handle, inode, &i, &is);
2361 if (!error && !bs.s.not_found) {
2362 i.value = NULL;
2363 error = ext4_xattr_block_set(handle, inode, &i, &bs);
2364 } else if (error == -ENOSPC) {
2365 if (EXT4_I(inode)->i_file_acl && !bs.s.base) {
2366 brelse(bs.bh);
2367 bs.bh = NULL;
2368 error = ext4_xattr_block_find(inode, &i, &bs);
2369 if (error)
2370 goto cleanup;
2371 }
2372 error = ext4_xattr_block_set(handle, inode, &i, &bs);
2373 if (!error && !is.s.not_found) {
2374 i.value = NULL;
2375 error = ext4_xattr_ibody_set(handle, inode, &i,
2376 &is);
2377 } else if (error == -ENOSPC) {
2378 /*
2379 * Xattr does not fit in the block, store at
2380 * external inode if possible.
2381 */
2382 if (ext4_has_feature_ea_inode(inode->i_sb) &&
2383 i.value_len && !i.in_inode) {
2384 i.in_inode = 1;
2385 goto retry_inode;
2386 }
2387 }
2388 }
2389 }
2390 if (!error) {
2391 ext4_xattr_update_super_block(handle, inode->i_sb);
2392 inode->i_ctime = current_time(inode);
2393 if (!value)
2394 no_expand = 0;
2395 error = ext4_mark_iloc_dirty(handle, inode, &is.iloc);
2396 /*
2397 * The bh is consumed by ext4_mark_iloc_dirty, even with
2398 * error != 0.
2399 */
2400 is.iloc.bh = NULL;
2401 if (IS_SYNC(inode))
2402 ext4_handle_sync(handle);
2403 }
2404 ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_XATTR);
2405
2406cleanup:
2407 brelse(is.iloc.bh);
2408 brelse(bs.bh);
2409 ext4_write_unlock_xattr(inode, &no_expand);
2410 return error;
2411}
2412
2413int ext4_xattr_set_credits(struct inode *inode, size_t value_len,
2414 bool is_create, int *credits)
2415{
2416 struct buffer_head *bh;
2417 int err;
2418
2419 *credits = 0;
2420
2421 if (!EXT4_SB(inode->i_sb)->s_journal)
2422 return 0;
2423
2424 down_read(&EXT4_I(inode)->xattr_sem);
2425
2426 bh = ext4_xattr_get_block(inode);
2427 if (IS_ERR(bh)) {
2428 err = PTR_ERR(bh);
2429 } else {
2430 *credits = __ext4_xattr_set_credits(inode->i_sb, inode, bh,
2431 value_len, is_create);
2432 brelse(bh);
2433 err = 0;
2434 }
2435
2436 up_read(&EXT4_I(inode)->xattr_sem);
2437 return err;
2438}
2439
2440/*
2441 * ext4_xattr_set()
2442 *
2443 * Like ext4_xattr_set_handle, but start from an inode. This extended
2444 * attribute modification is a filesystem transaction by itself.
2445 *
2446 * Returns 0, or a negative error number on failure.
2447 */
2448int
2449ext4_xattr_set(struct inode *inode, int name_index, const char *name,
2450 const void *value, size_t value_len, int flags)
2451{
2452 handle_t *handle;
2453 struct super_block *sb = inode->i_sb;
2454 int error, retries = 0;
2455 int credits;
2456
2457 error = dquot_initialize(inode);
2458 if (error)
2459 return error;
2460
2461retry:
2462 error = ext4_xattr_set_credits(inode, value_len, flags & XATTR_CREATE,
2463 &credits);
2464 if (error)
2465 return error;
2466
2467 handle = ext4_journal_start(inode, EXT4_HT_XATTR, credits);
2468 if (IS_ERR(handle)) {
2469 error = PTR_ERR(handle);
2470 } else {
2471 int error2;
2472
2473 error = ext4_xattr_set_handle(handle, inode, name_index, name,
2474 value, value_len, flags);
2475 error2 = ext4_journal_stop(handle);
2476 if (error == -ENOSPC &&
2477 ext4_should_retry_alloc(sb, &retries))
2478 goto retry;
2479 if (error == 0)
2480 error = error2;
2481 }
2482 ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_XATTR);
2483
2484 return error;
2485}
2486
2487/*
2488 * Shift the EA entries in the inode to create space for the increased
2489 * i_extra_isize.
2490 */
2491static void ext4_xattr_shift_entries(struct ext4_xattr_entry *entry,
2492 int value_offs_shift, void *to,
2493 void *from, size_t n)
2494{
2495 struct ext4_xattr_entry *last = entry;
2496 int new_offs;
2497
2498 /* We always shift xattr headers further thus offsets get lower */
2499 BUG_ON(value_offs_shift > 0);
2500
2501 /* Adjust the value offsets of the entries */
2502 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
2503 if (!last->e_value_inum && last->e_value_size) {
2504 new_offs = le16_to_cpu(last->e_value_offs) +
2505 value_offs_shift;
2506 last->e_value_offs = cpu_to_le16(new_offs);
2507 }
2508 }
2509 /* Shift the entries by n bytes */
2510 memmove(to, from, n);
2511}
2512
2513/*
2514 * Move xattr pointed to by 'entry' from inode into external xattr block
2515 */
2516static int ext4_xattr_move_to_block(handle_t *handle, struct inode *inode,
2517 struct ext4_inode *raw_inode,
2518 struct ext4_xattr_entry *entry)
2519{
2520 struct ext4_xattr_ibody_find *is = NULL;
2521 struct ext4_xattr_block_find *bs = NULL;
2522 char *buffer = NULL, *b_entry_name = NULL;
2523 size_t value_size = le32_to_cpu(entry->e_value_size);
2524 struct ext4_xattr_info i = {
2525 .value = NULL,
2526 .value_len = 0,
2527 .name_index = entry->e_name_index,
2528 .in_inode = !!entry->e_value_inum,
2529 };
2530 struct ext4_xattr_ibody_header *header = IHDR(inode, raw_inode);
2531 int error;
2532
2533 is = kzalloc(sizeof(struct ext4_xattr_ibody_find), GFP_NOFS);
2534 bs = kzalloc(sizeof(struct ext4_xattr_block_find), GFP_NOFS);
2535 buffer = kmalloc(value_size, GFP_NOFS);
2536 b_entry_name = kmalloc(entry->e_name_len + 1, GFP_NOFS);
2537 if (!is || !bs || !buffer || !b_entry_name) {
2538 error = -ENOMEM;
2539 goto out;
2540 }
2541
2542 is->s.not_found = -ENODATA;
2543 bs->s.not_found = -ENODATA;
2544 is->iloc.bh = NULL;
2545 bs->bh = NULL;
2546
2547 /* Save the entry name and the entry value */
2548 if (entry->e_value_inum) {
2549 error = ext4_xattr_inode_get(inode, entry, buffer, value_size);
2550 if (error)
2551 goto out;
2552 } else {
2553 size_t value_offs = le16_to_cpu(entry->e_value_offs);
2554 memcpy(buffer, (void *)IFIRST(header) + value_offs, value_size);
2555 }
2556
2557 memcpy(b_entry_name, entry->e_name, entry->e_name_len);
2558 b_entry_name[entry->e_name_len] = '\0';
2559 i.name = b_entry_name;
2560
2561 error = ext4_get_inode_loc(inode, &is->iloc);
2562 if (error)
2563 goto out;
2564
2565 error = ext4_xattr_ibody_find(inode, &i, is);
2566 if (error)
2567 goto out;
2568
2569 /* Remove the chosen entry from the inode */
2570 error = ext4_xattr_ibody_set(handle, inode, &i, is);
2571 if (error)
2572 goto out;
2573
2574 i.value = buffer;
2575 i.value_len = value_size;
2576 error = ext4_xattr_block_find(inode, &i, bs);
2577 if (error)
2578 goto out;
2579
2580 /* Add entry which was removed from the inode into the block */
2581 error = ext4_xattr_block_set(handle, inode, &i, bs);
2582 if (error)
2583 goto out;
2584 error = 0;
2585out:
2586 kfree(b_entry_name);
2587 kfree(buffer);
2588 if (is)
2589 brelse(is->iloc.bh);
2590 if (bs)
2591 brelse(bs->bh);
2592 kfree(is);
2593 kfree(bs);
2594
2595 return error;
2596}
2597
2598static int ext4_xattr_make_inode_space(handle_t *handle, struct inode *inode,
2599 struct ext4_inode *raw_inode,
2600 int isize_diff, size_t ifree,
2601 size_t bfree, int *total_ino)
2602{
2603 struct ext4_xattr_ibody_header *header = IHDR(inode, raw_inode);
2604 struct ext4_xattr_entry *small_entry;
2605 struct ext4_xattr_entry *entry;
2606 struct ext4_xattr_entry *last;
2607 unsigned int entry_size; /* EA entry size */
2608 unsigned int total_size; /* EA entry size + value size */
2609 unsigned int min_total_size;
2610 int error;
2611
2612 while (isize_diff > ifree) {
2613 entry = NULL;
2614 small_entry = NULL;
2615 min_total_size = ~0U;
2616 last = IFIRST(header);
2617 /* Find the entry best suited to be pushed into EA block */
2618 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
2619 /* never move system.data out of the inode */
2620 if ((last->e_name_len == 4) &&
2621 (last->e_name_index == EXT4_XATTR_INDEX_SYSTEM) &&
2622 !memcmp(last->e_name, "data", 4))
2623 continue;
2624 total_size = EXT4_XATTR_LEN(last->e_name_len);
2625 if (!last->e_value_inum)
2626 total_size += EXT4_XATTR_SIZE(
2627 le32_to_cpu(last->e_value_size));
2628 if (total_size <= bfree &&
2629 total_size < min_total_size) {
2630 if (total_size + ifree < isize_diff) {
2631 small_entry = last;
2632 } else {
2633 entry = last;
2634 min_total_size = total_size;
2635 }
2636 }
2637 }
2638
2639 if (entry == NULL) {
2640 if (small_entry == NULL)
2641 return -ENOSPC;
2642 entry = small_entry;
2643 }
2644
2645 entry_size = EXT4_XATTR_LEN(entry->e_name_len);
2646 total_size = entry_size;
2647 if (!entry->e_value_inum)
2648 total_size += EXT4_XATTR_SIZE(
2649 le32_to_cpu(entry->e_value_size));
2650 error = ext4_xattr_move_to_block(handle, inode, raw_inode,
2651 entry);
2652 if (error)
2653 return error;
2654
2655 *total_ino -= entry_size;
2656 ifree += total_size;
2657 bfree -= total_size;
2658 }
2659
2660 return 0;
2661}
2662
2663/*
2664 * Expand an inode by new_extra_isize bytes when EAs are present.
2665 * Returns 0 on success or negative error number on failure.
2666 */
2667int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
2668 struct ext4_inode *raw_inode, handle_t *handle)
2669{
2670 struct ext4_xattr_ibody_header *header;
2671 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2672 static unsigned int mnt_count;
2673 size_t min_offs;
2674 size_t ifree, bfree;
2675 int total_ino;
2676 void *base, *end;
2677 int error = 0, tried_min_extra_isize = 0;
2678 int s_min_extra_isize = le16_to_cpu(sbi->s_es->s_min_extra_isize);
2679 int isize_diff; /* How much do we need to grow i_extra_isize */
2680
2681retry:
2682 isize_diff = new_extra_isize - EXT4_I(inode)->i_extra_isize;
2683 if (EXT4_I(inode)->i_extra_isize >= new_extra_isize)
2684 return 0;
2685
2686 header = IHDR(inode, raw_inode);
2687
2688 /*
2689 * Check if enough free space is available in the inode to shift the
2690 * entries ahead by new_extra_isize.
2691 */
2692
2693 base = IFIRST(header);
2694 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
2695 min_offs = end - base;
2696 total_ino = sizeof(struct ext4_xattr_ibody_header) + sizeof(u32);
2697
2698 error = xattr_check_inode(inode, header, end);
2699 if (error)
2700 goto cleanup;
2701
2702 ifree = ext4_xattr_free_space(base, &min_offs, base, &total_ino);
2703 if (ifree >= isize_diff)
2704 goto shift;
2705
2706 /*
2707 * Enough free space isn't available in the inode, check if
2708 * EA block can hold new_extra_isize bytes.
2709 */
2710 if (EXT4_I(inode)->i_file_acl) {
2711 struct buffer_head *bh;
2712
2713 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
2714 if (IS_ERR(bh)) {
2715 error = PTR_ERR(bh);
2716 goto cleanup;
2717 }
2718 error = ext4_xattr_check_block(inode, bh);
2719 if (error) {
2720 brelse(bh);
2721 goto cleanup;
2722 }
2723 base = BHDR(bh);
2724 end = bh->b_data + bh->b_size;
2725 min_offs = end - base;
2726 bfree = ext4_xattr_free_space(BFIRST(bh), &min_offs, base,
2727 NULL);
2728 brelse(bh);
2729 if (bfree + ifree < isize_diff) {
2730 if (!tried_min_extra_isize && s_min_extra_isize) {
2731 tried_min_extra_isize++;
2732 new_extra_isize = s_min_extra_isize;
2733 goto retry;
2734 }
2735 error = -ENOSPC;
2736 goto cleanup;
2737 }
2738 } else {
2739 bfree = inode->i_sb->s_blocksize;
2740 }
2741
2742 error = ext4_xattr_make_inode_space(handle, inode, raw_inode,
2743 isize_diff, ifree, bfree,
2744 &total_ino);
2745 if (error) {
2746 if (error == -ENOSPC && !tried_min_extra_isize &&
2747 s_min_extra_isize) {
2748 tried_min_extra_isize++;
2749 new_extra_isize = s_min_extra_isize;
2750 goto retry;
2751 }
2752 goto cleanup;
2753 }
2754shift:
2755 /* Adjust the offsets and shift the remaining entries ahead */
2756 ext4_xattr_shift_entries(IFIRST(header), EXT4_I(inode)->i_extra_isize
2757 - new_extra_isize, (void *)raw_inode +
2758 EXT4_GOOD_OLD_INODE_SIZE + new_extra_isize,
2759 (void *)header, total_ino);
2760 EXT4_I(inode)->i_extra_isize = new_extra_isize;
2761
2762cleanup:
2763 if (error && (mnt_count != le16_to_cpu(sbi->s_es->s_mnt_count))) {
2764 ext4_warning(inode->i_sb, "Unable to expand inode %lu. Delete some EAs or run e2fsck.",
2765 inode->i_ino);
2766 mnt_count = le16_to_cpu(sbi->s_es->s_mnt_count);
2767 }
2768 return error;
2769}
2770
2771#define EIA_INCR 16 /* must be 2^n */
2772#define EIA_MASK (EIA_INCR - 1)
2773
2774/* Add the large xattr @inode into @ea_inode_array for deferred iput().
2775 * If @ea_inode_array is new or full it will be grown and the old
2776 * contents copied over.
2777 */
2778static int
2779ext4_expand_inode_array(struct ext4_xattr_inode_array **ea_inode_array,
2780 struct inode *inode)
2781{
2782 if (*ea_inode_array == NULL) {
2783 /*
2784 * Start with 15 inodes, so it fits into a power-of-two size.
2785 * If *ea_inode_array is NULL, this is essentially offsetof()
2786 */
2787 (*ea_inode_array) =
2788 kmalloc(offsetof(struct ext4_xattr_inode_array,
2789 inodes[EIA_MASK]),
2790 GFP_NOFS);
2791 if (*ea_inode_array == NULL)
2792 return -ENOMEM;
2793 (*ea_inode_array)->count = 0;
2794 } else if (((*ea_inode_array)->count & EIA_MASK) == EIA_MASK) {
2795 /* expand the array once all 15 + n * 16 slots are full */
2796 struct ext4_xattr_inode_array *new_array = NULL;
2797 int count = (*ea_inode_array)->count;
2798
2799 /* if new_array is NULL, this is essentially offsetof() */
2800 new_array = kmalloc(
2801 offsetof(struct ext4_xattr_inode_array,
2802 inodes[count + EIA_INCR]),
2803 GFP_NOFS);
2804 if (new_array == NULL)
2805 return -ENOMEM;
2806 memcpy(new_array, *ea_inode_array,
2807 offsetof(struct ext4_xattr_inode_array, inodes[count]));
2808 kfree(*ea_inode_array);
2809 *ea_inode_array = new_array;
2810 }
2811 (*ea_inode_array)->inodes[(*ea_inode_array)->count++] = inode;
2812 return 0;
2813}
2814
2815/*
2816 * ext4_xattr_delete_inode()
2817 *
2818 * Free extended attribute resources associated with this inode. Traverse
2819 * all entries and decrement reference on any xattr inodes associated with this
2820 * inode. This is called immediately before an inode is freed. We have exclusive
2821 * access to the inode. If an orphan inode is deleted it will also release its
2822 * references on xattr block and xattr inodes.
2823 */
2824int ext4_xattr_delete_inode(handle_t *handle, struct inode *inode,
2825 struct ext4_xattr_inode_array **ea_inode_array,
2826 int extra_credits)
2827{
2828 struct buffer_head *bh = NULL;
2829 struct ext4_xattr_ibody_header *header;
2830 struct ext4_iloc iloc = { .bh = NULL };
2831 struct ext4_xattr_entry *entry;
2832 struct inode *ea_inode;
2833 int error;
2834
2835 error = ext4_journal_ensure_credits(handle, extra_credits,
2836 ext4_free_metadata_revoke_credits(inode->i_sb, 1));
2837 if (error < 0) {
2838 EXT4_ERROR_INODE(inode, "ensure credits (error %d)", error);
2839 goto cleanup;
2840 }
2841
2842 if (ext4_has_feature_ea_inode(inode->i_sb) &&
2843 ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
2844
2845 error = ext4_get_inode_loc(inode, &iloc);
2846 if (error) {
2847 EXT4_ERROR_INODE(inode, "inode loc (error %d)", error);
2848 goto cleanup;
2849 }
2850
2851 error = ext4_journal_get_write_access(handle, iloc.bh);
2852 if (error) {
2853 EXT4_ERROR_INODE(inode, "write access (error %d)",
2854 error);
2855 goto cleanup;
2856 }
2857
2858 header = IHDR(inode, ext4_raw_inode(&iloc));
2859 if (header->h_magic == cpu_to_le32(EXT4_XATTR_MAGIC))
2860 ext4_xattr_inode_dec_ref_all(handle, inode, iloc.bh,
2861 IFIRST(header),
2862 false /* block_csum */,
2863 ea_inode_array,
2864 extra_credits,
2865 false /* skip_quota */);
2866 }
2867
2868 if (EXT4_I(inode)->i_file_acl) {
2869 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
2870 if (IS_ERR(bh)) {
2871 error = PTR_ERR(bh);
2872 if (error == -EIO) {
2873 EXT4_ERROR_INODE_ERR(inode, EIO,
2874 "block %llu read error",
2875 EXT4_I(inode)->i_file_acl);
2876 }
2877 bh = NULL;
2878 goto cleanup;
2879 }
2880 error = ext4_xattr_check_block(inode, bh);
2881 if (error)
2882 goto cleanup;
2883
2884 if (ext4_has_feature_ea_inode(inode->i_sb)) {
2885 for (entry = BFIRST(bh); !IS_LAST_ENTRY(entry);
2886 entry = EXT4_XATTR_NEXT(entry)) {
2887 if (!entry->e_value_inum)
2888 continue;
2889 error = ext4_xattr_inode_iget(inode,
2890 le32_to_cpu(entry->e_value_inum),
2891 le32_to_cpu(entry->e_hash),
2892 &ea_inode);
2893 if (error)
2894 continue;
2895 ext4_xattr_inode_free_quota(inode, ea_inode,
2896 le32_to_cpu(entry->e_value_size));
2897 iput(ea_inode);
2898 }
2899
2900 }
2901
2902 ext4_xattr_release_block(handle, inode, bh, ea_inode_array,
2903 extra_credits);
2904 /*
2905 * Update i_file_acl value in the same transaction that releases
2906 * block.
2907 */
2908 EXT4_I(inode)->i_file_acl = 0;
2909 error = ext4_mark_inode_dirty(handle, inode);
2910 if (error) {
2911 EXT4_ERROR_INODE(inode, "mark inode dirty (error %d)",
2912 error);
2913 goto cleanup;
2914 }
2915 ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_XATTR);
2916 }
2917 error = 0;
2918cleanup:
2919 brelse(iloc.bh);
2920 brelse(bh);
2921 return error;
2922}
2923
2924void ext4_xattr_inode_array_free(struct ext4_xattr_inode_array *ea_inode_array)
2925{
2926 int idx;
2927
2928 if (ea_inode_array == NULL)
2929 return;
2930
2931 for (idx = 0; idx < ea_inode_array->count; ++idx)
2932 iput(ea_inode_array->inodes[idx]);
2933 kfree(ea_inode_array);
2934}
2935
2936/*
2937 * ext4_xattr_block_cache_insert()
2938 *
2939 * Create a new entry in the extended attribute block cache, and insert
2940 * it unless such an entry is already in the cache.
2941 *
2942 * Returns 0, or a negative error number on failure.
2943 */
2944static void
2945ext4_xattr_block_cache_insert(struct mb_cache *ea_block_cache,
2946 struct buffer_head *bh)
2947{
2948 struct ext4_xattr_header *header = BHDR(bh);
2949 __u32 hash = le32_to_cpu(header->h_hash);
2950 int reusable = le32_to_cpu(header->h_refcount) <
2951 EXT4_XATTR_REFCOUNT_MAX;
2952 int error;
2953
2954 if (!ea_block_cache)
2955 return;
2956 error = mb_cache_entry_create(ea_block_cache, GFP_NOFS, hash,
2957 bh->b_blocknr, reusable);
2958 if (error) {
2959 if (error == -EBUSY)
2960 ea_bdebug(bh, "already in cache");
2961 } else
2962 ea_bdebug(bh, "inserting [%x]", (int)hash);
2963}
2964
2965/*
2966 * ext4_xattr_cmp()
2967 *
2968 * Compare two extended attribute blocks for equality.
2969 *
2970 * Returns 0 if the blocks are equal, 1 if they differ, and
2971 * a negative error number on errors.
2972 */
2973static int
2974ext4_xattr_cmp(struct ext4_xattr_header *header1,
2975 struct ext4_xattr_header *header2)
2976{
2977 struct ext4_xattr_entry *entry1, *entry2;
2978
2979 entry1 = ENTRY(header1+1);
2980 entry2 = ENTRY(header2+1);
2981 while (!IS_LAST_ENTRY(entry1)) {
2982 if (IS_LAST_ENTRY(entry2))
2983 return 1;
2984 if (entry1->e_hash != entry2->e_hash ||
2985 entry1->e_name_index != entry2->e_name_index ||
2986 entry1->e_name_len != entry2->e_name_len ||
2987 entry1->e_value_size != entry2->e_value_size ||
2988 entry1->e_value_inum != entry2->e_value_inum ||
2989 memcmp(entry1->e_name, entry2->e_name, entry1->e_name_len))
2990 return 1;
2991 if (!entry1->e_value_inum &&
2992 memcmp((char *)header1 + le16_to_cpu(entry1->e_value_offs),
2993 (char *)header2 + le16_to_cpu(entry2->e_value_offs),
2994 le32_to_cpu(entry1->e_value_size)))
2995 return 1;
2996
2997 entry1 = EXT4_XATTR_NEXT(entry1);
2998 entry2 = EXT4_XATTR_NEXT(entry2);
2999 }
3000 if (!IS_LAST_ENTRY(entry2))
3001 return 1;
3002 return 0;
3003}
3004
3005/*
3006 * ext4_xattr_block_cache_find()
3007 *
3008 * Find an identical extended attribute block.
3009 *
3010 * Returns a pointer to the block found, or NULL if such a block was
3011 * not found or an error occurred.
3012 */
3013static struct buffer_head *
3014ext4_xattr_block_cache_find(struct inode *inode,
3015 struct ext4_xattr_header *header,
3016 struct mb_cache_entry **pce)
3017{
3018 __u32 hash = le32_to_cpu(header->h_hash);
3019 struct mb_cache_entry *ce;
3020 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
3021
3022 if (!ea_block_cache)
3023 return NULL;
3024 if (!header->h_hash)
3025 return NULL; /* never share */
3026 ea_idebug(inode, "looking for cached blocks [%x]", (int)hash);
3027 ce = mb_cache_entry_find_first(ea_block_cache, hash);
3028 while (ce) {
3029 struct buffer_head *bh;
3030
3031 bh = ext4_sb_bread(inode->i_sb, ce->e_value, REQ_PRIO);
3032 if (IS_ERR(bh)) {
3033 if (PTR_ERR(bh) == -ENOMEM)
3034 return NULL;
3035 bh = NULL;
3036 EXT4_ERROR_INODE(inode, "block %lu read error",
3037 (unsigned long)ce->e_value);
3038 } else if (ext4_xattr_cmp(header, BHDR(bh)) == 0) {
3039 *pce = ce;
3040 return bh;
3041 }
3042 brelse(bh);
3043 ce = mb_cache_entry_find_next(ea_block_cache, ce);
3044 }
3045 return NULL;
3046}
3047
3048#define NAME_HASH_SHIFT 5
3049#define VALUE_HASH_SHIFT 16
3050
3051/*
3052 * ext4_xattr_hash_entry()
3053 *
3054 * Compute the hash of an extended attribute.
3055 */
3056static __le32 ext4_xattr_hash_entry(char *name, size_t name_len, __le32 *value,
3057 size_t value_count)
3058{
3059 __u32 hash = 0;
3060
3061 while (name_len--) {
3062 hash = (hash << NAME_HASH_SHIFT) ^
3063 (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^
3064 *name++;
3065 }
3066 while (value_count--) {
3067 hash = (hash << VALUE_HASH_SHIFT) ^
3068 (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^
3069 le32_to_cpu(*value++);
3070 }
3071 return cpu_to_le32(hash);
3072}
3073
3074#undef NAME_HASH_SHIFT
3075#undef VALUE_HASH_SHIFT
3076
3077#define BLOCK_HASH_SHIFT 16
3078
3079/*
3080 * ext4_xattr_rehash()
3081 *
3082 * Re-compute the extended attribute hash value after an entry has changed.
3083 */
3084static void ext4_xattr_rehash(struct ext4_xattr_header *header)
3085{
3086 struct ext4_xattr_entry *here;
3087 __u32 hash = 0;
3088
3089 here = ENTRY(header+1);
3090 while (!IS_LAST_ENTRY(here)) {
3091 if (!here->e_hash) {
3092 /* Block is not shared if an entry's hash value == 0 */
3093 hash = 0;
3094 break;
3095 }
3096 hash = (hash << BLOCK_HASH_SHIFT) ^
3097 (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^
3098 le32_to_cpu(here->e_hash);
3099 here = EXT4_XATTR_NEXT(here);
3100 }
3101 header->h_hash = cpu_to_le32(hash);
3102}
3103
3104#undef BLOCK_HASH_SHIFT
3105
3106#define HASH_BUCKET_BITS 10
3107
3108struct mb_cache *
3109ext4_xattr_create_cache(void)
3110{
3111 return mb_cache_create(HASH_BUCKET_BITS);
3112}
3113
3114void ext4_xattr_destroy_cache(struct mb_cache *cache)
3115{
3116 if (cache)
3117 mb_cache_destroy(cache);
3118}
3119