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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 ext4_set_feature_xattr(sb);
796 ext4_handle_dirty_super(handle, sb);
797 }
798}
799
800int ext4_get_inode_usage(struct inode *inode, qsize_t *usage)
801{
802 struct ext4_iloc iloc = { .bh = NULL };
803 struct buffer_head *bh = NULL;
804 struct ext4_inode *raw_inode;
805 struct ext4_xattr_ibody_header *header;
806 struct ext4_xattr_entry *entry;
807 qsize_t ea_inode_refs = 0;
808 void *end;
809 int ret;
810
811 lockdep_assert_held_read(&EXT4_I(inode)->xattr_sem);
812
813 if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
814 ret = ext4_get_inode_loc(inode, &iloc);
815 if (ret)
816 goto out;
817 raw_inode = ext4_raw_inode(&iloc);
818 header = IHDR(inode, raw_inode);
819 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
820 ret = xattr_check_inode(inode, header, end);
821 if (ret)
822 goto out;
823
824 for (entry = IFIRST(header); !IS_LAST_ENTRY(entry);
825 entry = EXT4_XATTR_NEXT(entry))
826 if (entry->e_value_inum)
827 ea_inode_refs++;
828 }
829
830 if (EXT4_I(inode)->i_file_acl) {
831 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
832 if (IS_ERR(bh)) {
833 ret = PTR_ERR(bh);
834 bh = NULL;
835 goto out;
836 }
837
838 ret = ext4_xattr_check_block(inode, bh);
839 if (ret)
840 goto out;
841
842 for (entry = BFIRST(bh); !IS_LAST_ENTRY(entry);
843 entry = EXT4_XATTR_NEXT(entry))
844 if (entry->e_value_inum)
845 ea_inode_refs++;
846 }
847 *usage = ea_inode_refs + 1;
848 ret = 0;
849out:
850 brelse(iloc.bh);
851 brelse(bh);
852 return ret;
853}
854
855static inline size_t round_up_cluster(struct inode *inode, size_t length)
856{
857 struct super_block *sb = inode->i_sb;
858 size_t cluster_size = 1 << (EXT4_SB(sb)->s_cluster_bits +
859 inode->i_blkbits);
860 size_t mask = ~(cluster_size - 1);
861
862 return (length + cluster_size - 1) & mask;
863}
864
865static int ext4_xattr_inode_alloc_quota(struct inode *inode, size_t len)
866{
867 int err;
868
869 err = dquot_alloc_inode(inode);
870 if (err)
871 return err;
872 err = dquot_alloc_space_nodirty(inode, round_up_cluster(inode, len));
873 if (err)
874 dquot_free_inode(inode);
875 return err;
876}
877
878static void ext4_xattr_inode_free_quota(struct inode *parent,
879 struct inode *ea_inode,
880 size_t len)
881{
882 if (ea_inode &&
883 ext4_test_inode_state(ea_inode, EXT4_STATE_LUSTRE_EA_INODE))
884 return;
885 dquot_free_space_nodirty(parent, round_up_cluster(parent, len));
886 dquot_free_inode(parent);
887}
888
889int __ext4_xattr_set_credits(struct super_block *sb, struct inode *inode,
890 struct buffer_head *block_bh, size_t value_len,
891 bool is_create)
892{
893 int credits;
894 int blocks;
895
896 /*
897 * 1) Owner inode update
898 * 2) Ref count update on old xattr block
899 * 3) new xattr block
900 * 4) block bitmap update for new xattr block
901 * 5) group descriptor for new xattr block
902 * 6) block bitmap update for old xattr block
903 * 7) group descriptor for old block
904 *
905 * 6 & 7 can happen if we have two racing threads T_a and T_b
906 * which are each trying to set an xattr on inodes I_a and I_b
907 * which were both initially sharing an xattr block.
908 */
909 credits = 7;
910
911 /* Quota updates. */
912 credits += EXT4_MAXQUOTAS_TRANS_BLOCKS(sb);
913
914 /*
915 * In case of inline data, we may push out the data to a block,
916 * so we need to reserve credits for this eventuality
917 */
918 if (inode && ext4_has_inline_data(inode))
919 credits += ext4_writepage_trans_blocks(inode) + 1;
920
921 /* We are done if ea_inode feature is not enabled. */
922 if (!ext4_has_feature_ea_inode(sb))
923 return credits;
924
925 /* New ea_inode, inode map, block bitmap, group descriptor. */
926 credits += 4;
927
928 /* Data blocks. */
929 blocks = (value_len + sb->s_blocksize - 1) >> sb->s_blocksize_bits;
930
931 /* Indirection block or one level of extent tree. */
932 blocks += 1;
933
934 /* Block bitmap and group descriptor updates for each block. */
935 credits += blocks * 2;
936
937 /* Blocks themselves. */
938 credits += blocks;
939
940 if (!is_create) {
941 /* Dereference ea_inode holding old xattr value.
942 * Old ea_inode, inode map, block bitmap, group descriptor.
943 */
944 credits += 4;
945
946 /* Data blocks for old ea_inode. */
947 blocks = XATTR_SIZE_MAX >> sb->s_blocksize_bits;
948
949 /* Indirection block or one level of extent tree for old
950 * ea_inode.
951 */
952 blocks += 1;
953
954 /* Block bitmap and group descriptor updates for each block. */
955 credits += blocks * 2;
956 }
957
958 /* We may need to clone the existing xattr block in which case we need
959 * to increment ref counts for existing ea_inodes referenced by it.
960 */
961 if (block_bh) {
962 struct ext4_xattr_entry *entry = BFIRST(block_bh);
963
964 for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry))
965 if (entry->e_value_inum)
966 /* Ref count update on ea_inode. */
967 credits += 1;
968 }
969 return credits;
970}
971
972static int ext4_xattr_inode_update_ref(handle_t *handle, struct inode *ea_inode,
973 int ref_change)
974{
975 struct mb_cache *ea_inode_cache = EA_INODE_CACHE(ea_inode);
976 struct ext4_iloc iloc;
977 s64 ref_count;
978 u32 hash;
979 int ret;
980
981 inode_lock(ea_inode);
982
983 ret = ext4_reserve_inode_write(handle, ea_inode, &iloc);
984 if (ret)
985 goto out;
986
987 ref_count = ext4_xattr_inode_get_ref(ea_inode);
988 ref_count += ref_change;
989 ext4_xattr_inode_set_ref(ea_inode, ref_count);
990
991 if (ref_change > 0) {
992 WARN_ONCE(ref_count <= 0, "EA inode %lu ref_count=%lld",
993 ea_inode->i_ino, ref_count);
994
995 if (ref_count == 1) {
996 WARN_ONCE(ea_inode->i_nlink, "EA inode %lu i_nlink=%u",
997 ea_inode->i_ino, ea_inode->i_nlink);
998
999 set_nlink(ea_inode, 1);
1000 ext4_orphan_del(handle, ea_inode);
1001
1002 if (ea_inode_cache) {
1003 hash = ext4_xattr_inode_get_hash(ea_inode);
1004 mb_cache_entry_create(ea_inode_cache,
1005 GFP_NOFS, hash,
1006 ea_inode->i_ino,
1007 true /* reusable */);
1008 }
1009 }
1010 } else {
1011 WARN_ONCE(ref_count < 0, "EA inode %lu ref_count=%lld",
1012 ea_inode->i_ino, ref_count);
1013
1014 if (ref_count == 0) {
1015 WARN_ONCE(ea_inode->i_nlink != 1,
1016 "EA inode %lu i_nlink=%u",
1017 ea_inode->i_ino, ea_inode->i_nlink);
1018
1019 clear_nlink(ea_inode);
1020 ext4_orphan_add(handle, ea_inode);
1021
1022 if (ea_inode_cache) {
1023 hash = ext4_xattr_inode_get_hash(ea_inode);
1024 mb_cache_entry_delete(ea_inode_cache, hash,
1025 ea_inode->i_ino);
1026 }
1027 }
1028 }
1029
1030 ret = ext4_mark_iloc_dirty(handle, ea_inode, &iloc);
1031 if (ret)
1032 ext4_warning_inode(ea_inode,
1033 "ext4_mark_iloc_dirty() failed ret=%d", ret);
1034out:
1035 inode_unlock(ea_inode);
1036 return ret;
1037}
1038
1039static int ext4_xattr_inode_inc_ref(handle_t *handle, struct inode *ea_inode)
1040{
1041 return ext4_xattr_inode_update_ref(handle, ea_inode, 1);
1042}
1043
1044static int ext4_xattr_inode_dec_ref(handle_t *handle, struct inode *ea_inode)
1045{
1046 return ext4_xattr_inode_update_ref(handle, ea_inode, -1);
1047}
1048
1049static int ext4_xattr_inode_inc_ref_all(handle_t *handle, struct inode *parent,
1050 struct ext4_xattr_entry *first)
1051{
1052 struct inode *ea_inode;
1053 struct ext4_xattr_entry *entry;
1054 struct ext4_xattr_entry *failed_entry;
1055 unsigned int ea_ino;
1056 int err, saved_err;
1057
1058 for (entry = first; !IS_LAST_ENTRY(entry);
1059 entry = EXT4_XATTR_NEXT(entry)) {
1060 if (!entry->e_value_inum)
1061 continue;
1062 ea_ino = le32_to_cpu(entry->e_value_inum);
1063 err = ext4_xattr_inode_iget(parent, ea_ino,
1064 le32_to_cpu(entry->e_hash),
1065 &ea_inode);
1066 if (err)
1067 goto cleanup;
1068 err = ext4_xattr_inode_inc_ref(handle, ea_inode);
1069 if (err) {
1070 ext4_warning_inode(ea_inode, "inc ref error %d", err);
1071 iput(ea_inode);
1072 goto cleanup;
1073 }
1074 iput(ea_inode);
1075 }
1076 return 0;
1077
1078cleanup:
1079 saved_err = err;
1080 failed_entry = entry;
1081
1082 for (entry = first; entry != failed_entry;
1083 entry = EXT4_XATTR_NEXT(entry)) {
1084 if (!entry->e_value_inum)
1085 continue;
1086 ea_ino = le32_to_cpu(entry->e_value_inum);
1087 err = ext4_xattr_inode_iget(parent, ea_ino,
1088 le32_to_cpu(entry->e_hash),
1089 &ea_inode);
1090 if (err) {
1091 ext4_warning(parent->i_sb,
1092 "cleanup ea_ino %u iget error %d", ea_ino,
1093 err);
1094 continue;
1095 }
1096 err = ext4_xattr_inode_dec_ref(handle, ea_inode);
1097 if (err)
1098 ext4_warning_inode(ea_inode, "cleanup dec ref error %d",
1099 err);
1100 iput(ea_inode);
1101 }
1102 return saved_err;
1103}
1104
1105static int ext4_xattr_restart_fn(handle_t *handle, struct inode *inode,
1106 struct buffer_head *bh, bool block_csum, bool dirty)
1107{
1108 int error;
1109
1110 if (bh && dirty) {
1111 if (block_csum)
1112 ext4_xattr_block_csum_set(inode, bh);
1113 error = ext4_handle_dirty_metadata(handle, NULL, bh);
1114 if (error) {
1115 ext4_warning(inode->i_sb, "Handle metadata (error %d)",
1116 error);
1117 return error;
1118 }
1119 }
1120 return 0;
1121}
1122
1123static void
1124ext4_xattr_inode_dec_ref_all(handle_t *handle, struct inode *parent,
1125 struct buffer_head *bh,
1126 struct ext4_xattr_entry *first, bool block_csum,
1127 struct ext4_xattr_inode_array **ea_inode_array,
1128 int extra_credits, bool skip_quota)
1129{
1130 struct inode *ea_inode;
1131 struct ext4_xattr_entry *entry;
1132 bool dirty = false;
1133 unsigned int ea_ino;
1134 int err;
1135 int credits;
1136
1137 /* One credit for dec ref on ea_inode, one for orphan list addition, */
1138 credits = 2 + extra_credits;
1139
1140 for (entry = first; !IS_LAST_ENTRY(entry);
1141 entry = EXT4_XATTR_NEXT(entry)) {
1142 if (!entry->e_value_inum)
1143 continue;
1144 ea_ino = le32_to_cpu(entry->e_value_inum);
1145 err = ext4_xattr_inode_iget(parent, ea_ino,
1146 le32_to_cpu(entry->e_hash),
1147 &ea_inode);
1148 if (err)
1149 continue;
1150
1151 err = ext4_expand_inode_array(ea_inode_array, ea_inode);
1152 if (err) {
1153 ext4_warning_inode(ea_inode,
1154 "Expand inode array err=%d", err);
1155 iput(ea_inode);
1156 continue;
1157 }
1158
1159 err = ext4_journal_ensure_credits_fn(handle, credits, credits,
1160 ext4_free_metadata_revoke_credits(parent->i_sb, 1),
1161 ext4_xattr_restart_fn(handle, parent, bh, block_csum,
1162 dirty));
1163 if (err < 0) {
1164 ext4_warning_inode(ea_inode, "Ensure credits err=%d",
1165 err);
1166 continue;
1167 }
1168 if (err > 0) {
1169 err = ext4_journal_get_write_access(handle, bh);
1170 if (err) {
1171 ext4_warning_inode(ea_inode,
1172 "Re-get write access err=%d",
1173 err);
1174 continue;
1175 }
1176 }
1177
1178 err = ext4_xattr_inode_dec_ref(handle, ea_inode);
1179 if (err) {
1180 ext4_warning_inode(ea_inode, "ea_inode dec ref err=%d",
1181 err);
1182 continue;
1183 }
1184
1185 if (!skip_quota)
1186 ext4_xattr_inode_free_quota(parent, ea_inode,
1187 le32_to_cpu(entry->e_value_size));
1188
1189 /*
1190 * Forget about ea_inode within the same transaction that
1191 * decrements the ref count. This avoids duplicate decrements in
1192 * case the rest of the work spills over to subsequent
1193 * transactions.
1194 */
1195 entry->e_value_inum = 0;
1196 entry->e_value_size = 0;
1197
1198 dirty = true;
1199 }
1200
1201 if (dirty) {
1202 /*
1203 * Note that we are deliberately skipping csum calculation for
1204 * the final update because we do not expect any journal
1205 * restarts until xattr block is freed.
1206 */
1207
1208 err = ext4_handle_dirty_metadata(handle, NULL, bh);
1209 if (err)
1210 ext4_warning_inode(parent,
1211 "handle dirty metadata err=%d", err);
1212 }
1213}
1214
1215/*
1216 * Release the xattr block BH: If the reference count is > 1, decrement it;
1217 * otherwise free the block.
1218 */
1219static void
1220ext4_xattr_release_block(handle_t *handle, struct inode *inode,
1221 struct buffer_head *bh,
1222 struct ext4_xattr_inode_array **ea_inode_array,
1223 int extra_credits)
1224{
1225 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
1226 u32 hash, ref;
1227 int error = 0;
1228
1229 BUFFER_TRACE(bh, "get_write_access");
1230 error = ext4_journal_get_write_access(handle, bh);
1231 if (error)
1232 goto out;
1233
1234 lock_buffer(bh);
1235 hash = le32_to_cpu(BHDR(bh)->h_hash);
1236 ref = le32_to_cpu(BHDR(bh)->h_refcount);
1237 if (ref == 1) {
1238 ea_bdebug(bh, "refcount now=0; freeing");
1239 /*
1240 * This must happen under buffer lock for
1241 * ext4_xattr_block_set() to reliably detect freed block
1242 */
1243 if (ea_block_cache)
1244 mb_cache_entry_delete(ea_block_cache, hash,
1245 bh->b_blocknr);
1246 get_bh(bh);
1247 unlock_buffer(bh);
1248
1249 if (ext4_has_feature_ea_inode(inode->i_sb))
1250 ext4_xattr_inode_dec_ref_all(handle, inode, bh,
1251 BFIRST(bh),
1252 true /* block_csum */,
1253 ea_inode_array,
1254 extra_credits,
1255 true /* skip_quota */);
1256 ext4_free_blocks(handle, inode, bh, 0, 1,
1257 EXT4_FREE_BLOCKS_METADATA |
1258 EXT4_FREE_BLOCKS_FORGET);
1259 } else {
1260 ref--;
1261 BHDR(bh)->h_refcount = cpu_to_le32(ref);
1262 if (ref == EXT4_XATTR_REFCOUNT_MAX - 1) {
1263 struct mb_cache_entry *ce;
1264
1265 if (ea_block_cache) {
1266 ce = mb_cache_entry_get(ea_block_cache, hash,
1267 bh->b_blocknr);
1268 if (ce) {
1269 ce->e_reusable = 1;
1270 mb_cache_entry_put(ea_block_cache, ce);
1271 }
1272 }
1273 }
1274
1275 ext4_xattr_block_csum_set(inode, bh);
1276 /*
1277 * Beware of this ugliness: Releasing of xattr block references
1278 * from different inodes can race and so we have to protect
1279 * from a race where someone else frees the block (and releases
1280 * its journal_head) before we are done dirtying the buffer. In
1281 * nojournal mode this race is harmless and we actually cannot
1282 * call ext4_handle_dirty_metadata() with locked buffer as
1283 * that function can call sync_dirty_buffer() so for that case
1284 * we handle the dirtying after unlocking the buffer.
1285 */
1286 if (ext4_handle_valid(handle))
1287 error = ext4_handle_dirty_metadata(handle, inode, bh);
1288 unlock_buffer(bh);
1289 if (!ext4_handle_valid(handle))
1290 error = ext4_handle_dirty_metadata(handle, inode, bh);
1291 if (IS_SYNC(inode))
1292 ext4_handle_sync(handle);
1293 dquot_free_block(inode, EXT4_C2B(EXT4_SB(inode->i_sb), 1));
1294 ea_bdebug(bh, "refcount now=%d; releasing",
1295 le32_to_cpu(BHDR(bh)->h_refcount));
1296 }
1297out:
1298 ext4_std_error(inode->i_sb, error);
1299 return;
1300}
1301
1302/*
1303 * Find the available free space for EAs. This also returns the total number of
1304 * bytes used by EA entries.
1305 */
1306static size_t ext4_xattr_free_space(struct ext4_xattr_entry *last,
1307 size_t *min_offs, void *base, int *total)
1308{
1309 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
1310 if (!last->e_value_inum && last->e_value_size) {
1311 size_t offs = le16_to_cpu(last->e_value_offs);
1312 if (offs < *min_offs)
1313 *min_offs = offs;
1314 }
1315 if (total)
1316 *total += EXT4_XATTR_LEN(last->e_name_len);
1317 }
1318 return (*min_offs - ((void *)last - base) - sizeof(__u32));
1319}
1320
1321/*
1322 * Write the value of the EA in an inode.
1323 */
1324static int ext4_xattr_inode_write(handle_t *handle, struct inode *ea_inode,
1325 const void *buf, int bufsize)
1326{
1327 struct buffer_head *bh = NULL;
1328 unsigned long block = 0;
1329 int blocksize = ea_inode->i_sb->s_blocksize;
1330 int max_blocks = (bufsize + blocksize - 1) >> ea_inode->i_blkbits;
1331 int csize, wsize = 0;
1332 int ret = 0, ret2 = 0;
1333 int retries = 0;
1334
1335retry:
1336 while (ret >= 0 && ret < max_blocks) {
1337 struct ext4_map_blocks map;
1338 map.m_lblk = block += ret;
1339 map.m_len = max_blocks -= ret;
1340
1341 ret = ext4_map_blocks(handle, ea_inode, &map,
1342 EXT4_GET_BLOCKS_CREATE);
1343 if (ret <= 0) {
1344 ext4_mark_inode_dirty(handle, ea_inode);
1345 if (ret == -ENOSPC &&
1346 ext4_should_retry_alloc(ea_inode->i_sb, &retries)) {
1347 ret = 0;
1348 goto retry;
1349 }
1350 break;
1351 }
1352 }
1353
1354 if (ret < 0)
1355 return ret;
1356
1357 block = 0;
1358 while (wsize < bufsize) {
1359 brelse(bh);
1360 csize = (bufsize - wsize) > blocksize ? blocksize :
1361 bufsize - wsize;
1362 bh = ext4_getblk(handle, ea_inode, block, 0);
1363 if (IS_ERR(bh))
1364 return PTR_ERR(bh);
1365 if (!bh) {
1366 WARN_ON_ONCE(1);
1367 EXT4_ERROR_INODE(ea_inode,
1368 "ext4_getblk() return bh = NULL");
1369 return -EFSCORRUPTED;
1370 }
1371 ret = ext4_journal_get_write_access(handle, bh);
1372 if (ret)
1373 goto out;
1374
1375 memcpy(bh->b_data, buf, csize);
1376 set_buffer_uptodate(bh);
1377 ext4_handle_dirty_metadata(handle, ea_inode, bh);
1378
1379 buf += csize;
1380 wsize += csize;
1381 block += 1;
1382 }
1383
1384 inode_lock(ea_inode);
1385 i_size_write(ea_inode, wsize);
1386 ext4_update_i_disksize(ea_inode, wsize);
1387 inode_unlock(ea_inode);
1388
1389 ret2 = ext4_mark_inode_dirty(handle, ea_inode);
1390 if (unlikely(ret2 && !ret))
1391 ret = ret2;
1392
1393out:
1394 brelse(bh);
1395
1396 return ret;
1397}
1398
1399/*
1400 * Create an inode to store the value of a large EA.
1401 */
1402static struct inode *ext4_xattr_inode_create(handle_t *handle,
1403 struct inode *inode, u32 hash)
1404{
1405 struct inode *ea_inode = NULL;
1406 uid_t owner[2] = { i_uid_read(inode), i_gid_read(inode) };
1407 int err;
1408
1409 /*
1410 * Let the next inode be the goal, so we try and allocate the EA inode
1411 * in the same group, or nearby one.
1412 */
1413 ea_inode = ext4_new_inode(handle, inode->i_sb->s_root->d_inode,
1414 S_IFREG | 0600, NULL, inode->i_ino + 1, owner,
1415 EXT4_EA_INODE_FL);
1416 if (!IS_ERR(ea_inode)) {
1417 ea_inode->i_op = &ext4_file_inode_operations;
1418 ea_inode->i_fop = &ext4_file_operations;
1419 ext4_set_aops(ea_inode);
1420 ext4_xattr_inode_set_class(ea_inode);
1421 unlock_new_inode(ea_inode);
1422 ext4_xattr_inode_set_ref(ea_inode, 1);
1423 ext4_xattr_inode_set_hash(ea_inode, hash);
1424 err = ext4_mark_inode_dirty(handle, ea_inode);
1425 if (!err)
1426 err = ext4_inode_attach_jinode(ea_inode);
1427 if (err) {
1428 iput(ea_inode);
1429 return ERR_PTR(err);
1430 }
1431
1432 /*
1433 * Xattr inodes are shared therefore quota charging is performed
1434 * at a higher level.
1435 */
1436 dquot_free_inode(ea_inode);
1437 dquot_drop(ea_inode);
1438 inode_lock(ea_inode);
1439 ea_inode->i_flags |= S_NOQUOTA;
1440 inode_unlock(ea_inode);
1441 }
1442
1443 return ea_inode;
1444}
1445
1446static struct inode *
1447ext4_xattr_inode_cache_find(struct inode *inode, const void *value,
1448 size_t value_len, u32 hash)
1449{
1450 struct inode *ea_inode;
1451 struct mb_cache_entry *ce;
1452 struct mb_cache *ea_inode_cache = EA_INODE_CACHE(inode);
1453 void *ea_data;
1454
1455 if (!ea_inode_cache)
1456 return NULL;
1457
1458 ce = mb_cache_entry_find_first(ea_inode_cache, hash);
1459 if (!ce)
1460 return NULL;
1461
1462 ea_data = kvmalloc(value_len, GFP_KERNEL);
1463 if (!ea_data) {
1464 mb_cache_entry_put(ea_inode_cache, ce);
1465 return NULL;
1466 }
1467
1468 while (ce) {
1469 ea_inode = ext4_iget(inode->i_sb, ce->e_value,
1470 EXT4_IGET_NORMAL);
1471 if (!IS_ERR(ea_inode) &&
1472 !is_bad_inode(ea_inode) &&
1473 (EXT4_I(ea_inode)->i_flags & EXT4_EA_INODE_FL) &&
1474 i_size_read(ea_inode) == value_len &&
1475 !ext4_xattr_inode_read(ea_inode, ea_data, value_len) &&
1476 !ext4_xattr_inode_verify_hashes(ea_inode, NULL, ea_data,
1477 value_len) &&
1478 !memcmp(value, ea_data, value_len)) {
1479 mb_cache_entry_touch(ea_inode_cache, ce);
1480 mb_cache_entry_put(ea_inode_cache, ce);
1481 kvfree(ea_data);
1482 return ea_inode;
1483 }
1484
1485 if (!IS_ERR(ea_inode))
1486 iput(ea_inode);
1487 ce = mb_cache_entry_find_next(ea_inode_cache, ce);
1488 }
1489 kvfree(ea_data);
1490 return NULL;
1491}
1492
1493/*
1494 * Add value of the EA in an inode.
1495 */
1496static int ext4_xattr_inode_lookup_create(handle_t *handle, struct inode *inode,
1497 const void *value, size_t value_len,
1498 struct inode **ret_inode)
1499{
1500 struct inode *ea_inode;
1501 u32 hash;
1502 int err;
1503
1504 hash = ext4_xattr_inode_hash(EXT4_SB(inode->i_sb), value, value_len);
1505 ea_inode = ext4_xattr_inode_cache_find(inode, value, value_len, hash);
1506 if (ea_inode) {
1507 err = ext4_xattr_inode_inc_ref(handle, ea_inode);
1508 if (err) {
1509 iput(ea_inode);
1510 return err;
1511 }
1512
1513 *ret_inode = ea_inode;
1514 return 0;
1515 }
1516
1517 /* Create an inode for the EA value */
1518 ea_inode = ext4_xattr_inode_create(handle, inode, hash);
1519 if (IS_ERR(ea_inode))
1520 return PTR_ERR(ea_inode);
1521
1522 err = ext4_xattr_inode_write(handle, ea_inode, value, value_len);
1523 if (err) {
1524 ext4_xattr_inode_dec_ref(handle, ea_inode);
1525 iput(ea_inode);
1526 return err;
1527 }
1528
1529 if (EA_INODE_CACHE(inode))
1530 mb_cache_entry_create(EA_INODE_CACHE(inode), GFP_NOFS, hash,
1531 ea_inode->i_ino, true /* reusable */);
1532
1533 *ret_inode = ea_inode;
1534 return 0;
1535}
1536
1537/*
1538 * Reserve min(block_size/8, 1024) bytes for xattr entries/names if ea_inode
1539 * feature is enabled.
1540 */
1541#define EXT4_XATTR_BLOCK_RESERVE(inode) min(i_blocksize(inode)/8, 1024U)
1542
1543static int ext4_xattr_set_entry(struct ext4_xattr_info *i,
1544 struct ext4_xattr_search *s,
1545 handle_t *handle, struct inode *inode,
1546 bool is_block)
1547{
1548 struct ext4_xattr_entry *last, *next;
1549 struct ext4_xattr_entry *here = s->here;
1550 size_t min_offs = s->end - s->base, name_len = strlen(i->name);
1551 int in_inode = i->in_inode;
1552 struct inode *old_ea_inode = NULL;
1553 struct inode *new_ea_inode = NULL;
1554 size_t old_size, new_size;
1555 int ret;
1556
1557 /* Space used by old and new values. */
1558 old_size = (!s->not_found && !here->e_value_inum) ?
1559 EXT4_XATTR_SIZE(le32_to_cpu(here->e_value_size)) : 0;
1560 new_size = (i->value && !in_inode) ? EXT4_XATTR_SIZE(i->value_len) : 0;
1561
1562 /*
1563 * Optimization for the simple case when old and new values have the
1564 * same padded sizes. Not applicable if external inodes are involved.
1565 */
1566 if (new_size && new_size == old_size) {
1567 size_t offs = le16_to_cpu(here->e_value_offs);
1568 void *val = s->base + offs;
1569
1570 here->e_value_size = cpu_to_le32(i->value_len);
1571 if (i->value == EXT4_ZERO_XATTR_VALUE) {
1572 memset(val, 0, new_size);
1573 } else {
1574 memcpy(val, i->value, i->value_len);
1575 /* Clear padding bytes. */
1576 memset(val + i->value_len, 0, new_size - i->value_len);
1577 }
1578 goto update_hash;
1579 }
1580
1581 /* Compute min_offs and last. */
1582 last = s->first;
1583 for (; !IS_LAST_ENTRY(last); last = next) {
1584 next = EXT4_XATTR_NEXT(last);
1585 if ((void *)next >= s->end) {
1586 EXT4_ERROR_INODE(inode, "corrupted xattr entries");
1587 ret = -EFSCORRUPTED;
1588 goto out;
1589 }
1590 if (!last->e_value_inum && last->e_value_size) {
1591 size_t offs = le16_to_cpu(last->e_value_offs);
1592 if (offs < min_offs)
1593 min_offs = offs;
1594 }
1595 }
1596
1597 /* Check whether we have enough space. */
1598 if (i->value) {
1599 size_t free;
1600
1601 free = min_offs - ((void *)last - s->base) - sizeof(__u32);
1602 if (!s->not_found)
1603 free += EXT4_XATTR_LEN(name_len) + old_size;
1604
1605 if (free < EXT4_XATTR_LEN(name_len) + new_size) {
1606 ret = -ENOSPC;
1607 goto out;
1608 }
1609
1610 /*
1611 * If storing the value in an external inode is an option,
1612 * reserve space for xattr entries/names in the external
1613 * attribute block so that a long value does not occupy the
1614 * whole space and prevent futher entries being added.
1615 */
1616 if (ext4_has_feature_ea_inode(inode->i_sb) &&
1617 new_size && is_block &&
1618 (min_offs + old_size - new_size) <
1619 EXT4_XATTR_BLOCK_RESERVE(inode)) {
1620 ret = -ENOSPC;
1621 goto out;
1622 }
1623 }
1624
1625 /*
1626 * Getting access to old and new ea inodes is subject to failures.
1627 * Finish that work before doing any modifications to the xattr data.
1628 */
1629 if (!s->not_found && here->e_value_inum) {
1630 ret = ext4_xattr_inode_iget(inode,
1631 le32_to_cpu(here->e_value_inum),
1632 le32_to_cpu(here->e_hash),
1633 &old_ea_inode);
1634 if (ret) {
1635 old_ea_inode = NULL;
1636 goto out;
1637 }
1638 }
1639 if (i->value && in_inode) {
1640 WARN_ON_ONCE(!i->value_len);
1641
1642 ret = ext4_xattr_inode_alloc_quota(inode, i->value_len);
1643 if (ret)
1644 goto out;
1645
1646 ret = ext4_xattr_inode_lookup_create(handle, inode, i->value,
1647 i->value_len,
1648 &new_ea_inode);
1649 if (ret) {
1650 new_ea_inode = NULL;
1651 ext4_xattr_inode_free_quota(inode, NULL, i->value_len);
1652 goto out;
1653 }
1654 }
1655
1656 if (old_ea_inode) {
1657 /* We are ready to release ref count on the old_ea_inode. */
1658 ret = ext4_xattr_inode_dec_ref(handle, old_ea_inode);
1659 if (ret) {
1660 /* Release newly required ref count on new_ea_inode. */
1661 if (new_ea_inode) {
1662 int err;
1663
1664 err = ext4_xattr_inode_dec_ref(handle,
1665 new_ea_inode);
1666 if (err)
1667 ext4_warning_inode(new_ea_inode,
1668 "dec ref new_ea_inode err=%d",
1669 err);
1670 ext4_xattr_inode_free_quota(inode, new_ea_inode,
1671 i->value_len);
1672 }
1673 goto out;
1674 }
1675
1676 ext4_xattr_inode_free_quota(inode, old_ea_inode,
1677 le32_to_cpu(here->e_value_size));
1678 }
1679
1680 /* No failures allowed past this point. */
1681
1682 if (!s->not_found && here->e_value_size && !here->e_value_inum) {
1683 /* Remove the old value. */
1684 void *first_val = s->base + min_offs;
1685 size_t offs = le16_to_cpu(here->e_value_offs);
1686 void *val = s->base + offs;
1687
1688 memmove(first_val + old_size, first_val, val - first_val);
1689 memset(first_val, 0, old_size);
1690 min_offs += old_size;
1691
1692 /* Adjust all value offsets. */
1693 last = s->first;
1694 while (!IS_LAST_ENTRY(last)) {
1695 size_t o = le16_to_cpu(last->e_value_offs);
1696
1697 if (!last->e_value_inum &&
1698 last->e_value_size && o < offs)
1699 last->e_value_offs = cpu_to_le16(o + old_size);
1700 last = EXT4_XATTR_NEXT(last);
1701 }
1702 }
1703
1704 if (!i->value) {
1705 /* Remove old name. */
1706 size_t size = EXT4_XATTR_LEN(name_len);
1707
1708 last = ENTRY((void *)last - size);
1709 memmove(here, (void *)here + size,
1710 (void *)last - (void *)here + sizeof(__u32));
1711 memset(last, 0, size);
1712 } else if (s->not_found) {
1713 /* Insert new name. */
1714 size_t size = EXT4_XATTR_LEN(name_len);
1715 size_t rest = (void *)last - (void *)here + sizeof(__u32);
1716
1717 memmove((void *)here + size, here, rest);
1718 memset(here, 0, size);
1719 here->e_name_index = i->name_index;
1720 here->e_name_len = name_len;
1721 memcpy(here->e_name, i->name, name_len);
1722 } else {
1723 /* This is an update, reset value info. */
1724 here->e_value_inum = 0;
1725 here->e_value_offs = 0;
1726 here->e_value_size = 0;
1727 }
1728
1729 if (i->value) {
1730 /* Insert new value. */
1731 if (in_inode) {
1732 here->e_value_inum = cpu_to_le32(new_ea_inode->i_ino);
1733 } else if (i->value_len) {
1734 void *val = s->base + min_offs - new_size;
1735
1736 here->e_value_offs = cpu_to_le16(min_offs - new_size);
1737 if (i->value == EXT4_ZERO_XATTR_VALUE) {
1738 memset(val, 0, new_size);
1739 } else {
1740 memcpy(val, i->value, i->value_len);
1741 /* Clear padding bytes. */
1742 memset(val + i->value_len, 0,
1743 new_size - i->value_len);
1744 }
1745 }
1746 here->e_value_size = cpu_to_le32(i->value_len);
1747 }
1748
1749update_hash:
1750 if (i->value) {
1751 __le32 hash = 0;
1752
1753 /* Entry hash calculation. */
1754 if (in_inode) {
1755 __le32 crc32c_hash;
1756
1757 /*
1758 * Feed crc32c hash instead of the raw value for entry
1759 * hash calculation. This is to avoid walking
1760 * potentially long value buffer again.
1761 */
1762 crc32c_hash = cpu_to_le32(
1763 ext4_xattr_inode_get_hash(new_ea_inode));
1764 hash = ext4_xattr_hash_entry(here->e_name,
1765 here->e_name_len,
1766 &crc32c_hash, 1);
1767 } else if (is_block) {
1768 __le32 *value = s->base + le16_to_cpu(
1769 here->e_value_offs);
1770
1771 hash = ext4_xattr_hash_entry(here->e_name,
1772 here->e_name_len, value,
1773 new_size >> 2);
1774 }
1775 here->e_hash = hash;
1776 }
1777
1778 if (is_block)
1779 ext4_xattr_rehash((struct ext4_xattr_header *)s->base);
1780
1781 ret = 0;
1782out:
1783 iput(old_ea_inode);
1784 iput(new_ea_inode);
1785 return ret;
1786}
1787
1788struct ext4_xattr_block_find {
1789 struct ext4_xattr_search s;
1790 struct buffer_head *bh;
1791};
1792
1793static int
1794ext4_xattr_block_find(struct inode *inode, struct ext4_xattr_info *i,
1795 struct ext4_xattr_block_find *bs)
1796{
1797 struct super_block *sb = inode->i_sb;
1798 int error;
1799
1800 ea_idebug(inode, "name=%d.%s, value=%p, value_len=%ld",
1801 i->name_index, i->name, i->value, (long)i->value_len);
1802
1803 if (EXT4_I(inode)->i_file_acl) {
1804 /* The inode already has an extended attribute block. */
1805 bs->bh = ext4_sb_bread(sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
1806 if (IS_ERR(bs->bh)) {
1807 error = PTR_ERR(bs->bh);
1808 bs->bh = NULL;
1809 return error;
1810 }
1811 ea_bdebug(bs->bh, "b_count=%d, refcount=%d",
1812 atomic_read(&(bs->bh->b_count)),
1813 le32_to_cpu(BHDR(bs->bh)->h_refcount));
1814 error = ext4_xattr_check_block(inode, bs->bh);
1815 if (error)
1816 return error;
1817 /* Find the named attribute. */
1818 bs->s.base = BHDR(bs->bh);
1819 bs->s.first = BFIRST(bs->bh);
1820 bs->s.end = bs->bh->b_data + bs->bh->b_size;
1821 bs->s.here = bs->s.first;
1822 error = xattr_find_entry(inode, &bs->s.here, bs->s.end,
1823 i->name_index, i->name, 1);
1824 if (error && error != -ENODATA)
1825 return error;
1826 bs->s.not_found = error;
1827 }
1828 return 0;
1829}
1830
1831static int
1832ext4_xattr_block_set(handle_t *handle, struct inode *inode,
1833 struct ext4_xattr_info *i,
1834 struct ext4_xattr_block_find *bs)
1835{
1836 struct super_block *sb = inode->i_sb;
1837 struct buffer_head *new_bh = NULL;
1838 struct ext4_xattr_search s_copy = bs->s;
1839 struct ext4_xattr_search *s = &s_copy;
1840 struct mb_cache_entry *ce = NULL;
1841 int error = 0;
1842 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
1843 struct inode *ea_inode = NULL, *tmp_inode;
1844 size_t old_ea_inode_quota = 0;
1845 unsigned int ea_ino;
1846
1847
1848#define header(x) ((struct ext4_xattr_header *)(x))
1849
1850 if (s->base) {
1851 BUFFER_TRACE(bs->bh, "get_write_access");
1852 error = ext4_journal_get_write_access(handle, bs->bh);
1853 if (error)
1854 goto cleanup;
1855 lock_buffer(bs->bh);
1856
1857 if (header(s->base)->h_refcount == cpu_to_le32(1)) {
1858 __u32 hash = le32_to_cpu(BHDR(bs->bh)->h_hash);
1859
1860 /*
1861 * This must happen under buffer lock for
1862 * ext4_xattr_block_set() to reliably detect modified
1863 * block
1864 */
1865 if (ea_block_cache)
1866 mb_cache_entry_delete(ea_block_cache, hash,
1867 bs->bh->b_blocknr);
1868 ea_bdebug(bs->bh, "modifying in-place");
1869 error = ext4_xattr_set_entry(i, s, handle, inode,
1870 true /* is_block */);
1871 ext4_xattr_block_csum_set(inode, bs->bh);
1872 unlock_buffer(bs->bh);
1873 if (error == -EFSCORRUPTED)
1874 goto bad_block;
1875 if (!error)
1876 error = ext4_handle_dirty_metadata(handle,
1877 inode,
1878 bs->bh);
1879 if (error)
1880 goto cleanup;
1881 goto inserted;
1882 } else {
1883 int offset = (char *)s->here - bs->bh->b_data;
1884
1885 unlock_buffer(bs->bh);
1886 ea_bdebug(bs->bh, "cloning");
1887 s->base = kmalloc(bs->bh->b_size, GFP_NOFS);
1888 error = -ENOMEM;
1889 if (s->base == NULL)
1890 goto cleanup;
1891 memcpy(s->base, BHDR(bs->bh), bs->bh->b_size);
1892 s->first = ENTRY(header(s->base)+1);
1893 header(s->base)->h_refcount = cpu_to_le32(1);
1894 s->here = ENTRY(s->base + offset);
1895 s->end = s->base + bs->bh->b_size;
1896
1897 /*
1898 * If existing entry points to an xattr inode, we need
1899 * to prevent ext4_xattr_set_entry() from decrementing
1900 * ref count on it because the reference belongs to the
1901 * original block. In this case, make the entry look
1902 * like it has an empty value.
1903 */
1904 if (!s->not_found && s->here->e_value_inum) {
1905 ea_ino = le32_to_cpu(s->here->e_value_inum);
1906 error = ext4_xattr_inode_iget(inode, ea_ino,
1907 le32_to_cpu(s->here->e_hash),
1908 &tmp_inode);
1909 if (error)
1910 goto cleanup;
1911
1912 if (!ext4_test_inode_state(tmp_inode,
1913 EXT4_STATE_LUSTRE_EA_INODE)) {
1914 /*
1915 * Defer quota free call for previous
1916 * inode until success is guaranteed.
1917 */
1918 old_ea_inode_quota = le32_to_cpu(
1919 s->here->e_value_size);
1920 }
1921 iput(tmp_inode);
1922
1923 s->here->e_value_inum = 0;
1924 s->here->e_value_size = 0;
1925 }
1926 }
1927 } else {
1928 /* Allocate a buffer where we construct the new block. */
1929 s->base = kzalloc(sb->s_blocksize, GFP_NOFS);
1930 /* assert(header == s->base) */
1931 error = -ENOMEM;
1932 if (s->base == NULL)
1933 goto cleanup;
1934 header(s->base)->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
1935 header(s->base)->h_blocks = cpu_to_le32(1);
1936 header(s->base)->h_refcount = cpu_to_le32(1);
1937 s->first = ENTRY(header(s->base)+1);
1938 s->here = ENTRY(header(s->base)+1);
1939 s->end = s->base + sb->s_blocksize;
1940 }
1941
1942 error = ext4_xattr_set_entry(i, s, handle, inode, true /* is_block */);
1943 if (error == -EFSCORRUPTED)
1944 goto bad_block;
1945 if (error)
1946 goto cleanup;
1947
1948 if (i->value && s->here->e_value_inum) {
1949 /*
1950 * A ref count on ea_inode has been taken as part of the call to
1951 * ext4_xattr_set_entry() above. We would like to drop this
1952 * extra ref but we have to wait until the xattr block is
1953 * initialized and has its own ref count on the ea_inode.
1954 */
1955 ea_ino = le32_to_cpu(s->here->e_value_inum);
1956 error = ext4_xattr_inode_iget(inode, ea_ino,
1957 le32_to_cpu(s->here->e_hash),
1958 &ea_inode);
1959 if (error) {
1960 ea_inode = NULL;
1961 goto cleanup;
1962 }
1963 }
1964
1965inserted:
1966 if (!IS_LAST_ENTRY(s->first)) {
1967 new_bh = ext4_xattr_block_cache_find(inode, header(s->base),
1968 &ce);
1969 if (new_bh) {
1970 /* We found an identical block in the cache. */
1971 if (new_bh == bs->bh)
1972 ea_bdebug(new_bh, "keeping");
1973 else {
1974 u32 ref;
1975
1976 WARN_ON_ONCE(dquot_initialize_needed(inode));
1977
1978 /* The old block is released after updating
1979 the inode. */
1980 error = dquot_alloc_block(inode,
1981 EXT4_C2B(EXT4_SB(sb), 1));
1982 if (error)
1983 goto cleanup;
1984 BUFFER_TRACE(new_bh, "get_write_access");
1985 error = ext4_journal_get_write_access(handle,
1986 new_bh);
1987 if (error)
1988 goto cleanup_dquot;
1989 lock_buffer(new_bh);
1990 /*
1991 * We have to be careful about races with
1992 * freeing, rehashing or adding references to
1993 * xattr block. Once we hold buffer lock xattr
1994 * block's state is stable so we can check
1995 * whether the block got freed / rehashed or
1996 * not. Since we unhash mbcache entry under
1997 * buffer lock when freeing / rehashing xattr
1998 * block, checking whether entry is still
1999 * hashed is reliable. Same rules hold for
2000 * e_reusable handling.
2001 */
2002 if (hlist_bl_unhashed(&ce->e_hash_list) ||
2003 !ce->e_reusable) {
2004 /*
2005 * Undo everything and check mbcache
2006 * again.
2007 */
2008 unlock_buffer(new_bh);
2009 dquot_free_block(inode,
2010 EXT4_C2B(EXT4_SB(sb),
2011 1));
2012 brelse(new_bh);
2013 mb_cache_entry_put(ea_block_cache, ce);
2014 ce = NULL;
2015 new_bh = NULL;
2016 goto inserted;
2017 }
2018 ref = le32_to_cpu(BHDR(new_bh)->h_refcount) + 1;
2019 BHDR(new_bh)->h_refcount = cpu_to_le32(ref);
2020 if (ref >= EXT4_XATTR_REFCOUNT_MAX)
2021 ce->e_reusable = 0;
2022 ea_bdebug(new_bh, "reusing; refcount now=%d",
2023 ref);
2024 ext4_xattr_block_csum_set(inode, new_bh);
2025 unlock_buffer(new_bh);
2026 error = ext4_handle_dirty_metadata(handle,
2027 inode,
2028 new_bh);
2029 if (error)
2030 goto cleanup_dquot;
2031 }
2032 mb_cache_entry_touch(ea_block_cache, ce);
2033 mb_cache_entry_put(ea_block_cache, ce);
2034 ce = NULL;
2035 } else if (bs->bh && s->base == bs->bh->b_data) {
2036 /* We were modifying this block in-place. */
2037 ea_bdebug(bs->bh, "keeping this block");
2038 ext4_xattr_block_cache_insert(ea_block_cache, bs->bh);
2039 new_bh = bs->bh;
2040 get_bh(new_bh);
2041 } else {
2042 /* We need to allocate a new block */
2043 ext4_fsblk_t goal, block;
2044
2045 WARN_ON_ONCE(dquot_initialize_needed(inode));
2046
2047 goal = ext4_group_first_block_no(sb,
2048 EXT4_I(inode)->i_block_group);
2049
2050 /* non-extent files can't have physical blocks past 2^32 */
2051 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
2052 goal = goal & EXT4_MAX_BLOCK_FILE_PHYS;
2053
2054 block = ext4_new_meta_blocks(handle, inode, goal, 0,
2055 NULL, &error);
2056 if (error)
2057 goto cleanup;
2058
2059 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
2060 BUG_ON(block > EXT4_MAX_BLOCK_FILE_PHYS);
2061
2062 ea_idebug(inode, "creating block %llu",
2063 (unsigned long long)block);
2064
2065 new_bh = sb_getblk(sb, block);
2066 if (unlikely(!new_bh)) {
2067 error = -ENOMEM;
2068getblk_failed:
2069 ext4_free_blocks(handle, inode, NULL, block, 1,
2070 EXT4_FREE_BLOCKS_METADATA);
2071 goto cleanup;
2072 }
2073 error = ext4_xattr_inode_inc_ref_all(handle, inode,
2074 ENTRY(header(s->base)+1));
2075 if (error)
2076 goto getblk_failed;
2077 if (ea_inode) {
2078 /* Drop the extra ref on ea_inode. */
2079 error = ext4_xattr_inode_dec_ref(handle,
2080 ea_inode);
2081 if (error)
2082 ext4_warning_inode(ea_inode,
2083 "dec ref error=%d",
2084 error);
2085 iput(ea_inode);
2086 ea_inode = NULL;
2087 }
2088
2089 lock_buffer(new_bh);
2090 error = ext4_journal_get_create_access(handle, new_bh);
2091 if (error) {
2092 unlock_buffer(new_bh);
2093 error = -EIO;
2094 goto getblk_failed;
2095 }
2096 memcpy(new_bh->b_data, s->base, new_bh->b_size);
2097 ext4_xattr_block_csum_set(inode, new_bh);
2098 set_buffer_uptodate(new_bh);
2099 unlock_buffer(new_bh);
2100 ext4_xattr_block_cache_insert(ea_block_cache, new_bh);
2101 error = ext4_handle_dirty_metadata(handle, inode,
2102 new_bh);
2103 if (error)
2104 goto cleanup;
2105 }
2106 }
2107
2108 if (old_ea_inode_quota)
2109 ext4_xattr_inode_free_quota(inode, NULL, old_ea_inode_quota);
2110
2111 /* Update the inode. */
2112 EXT4_I(inode)->i_file_acl = new_bh ? new_bh->b_blocknr : 0;
2113
2114 /* Drop the previous xattr block. */
2115 if (bs->bh && bs->bh != new_bh) {
2116 struct ext4_xattr_inode_array *ea_inode_array = NULL;
2117
2118 ext4_xattr_release_block(handle, inode, bs->bh,
2119 &ea_inode_array,
2120 0 /* extra_credits */);
2121 ext4_xattr_inode_array_free(ea_inode_array);
2122 }
2123 error = 0;
2124
2125cleanup:
2126 if (ea_inode) {
2127 int error2;
2128
2129 error2 = ext4_xattr_inode_dec_ref(handle, ea_inode);
2130 if (error2)
2131 ext4_warning_inode(ea_inode, "dec ref error=%d",
2132 error2);
2133
2134 /* If there was an error, revert the quota charge. */
2135 if (error)
2136 ext4_xattr_inode_free_quota(inode, ea_inode,
2137 i_size_read(ea_inode));
2138 iput(ea_inode);
2139 }
2140 if (ce)
2141 mb_cache_entry_put(ea_block_cache, ce);
2142 brelse(new_bh);
2143 if (!(bs->bh && s->base == bs->bh->b_data))
2144 kfree(s->base);
2145
2146 return error;
2147
2148cleanup_dquot:
2149 dquot_free_block(inode, EXT4_C2B(EXT4_SB(sb), 1));
2150 goto cleanup;
2151
2152bad_block:
2153 EXT4_ERROR_INODE(inode, "bad block %llu",
2154 EXT4_I(inode)->i_file_acl);
2155 goto cleanup;
2156
2157#undef header
2158}
2159
2160int ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i,
2161 struct ext4_xattr_ibody_find *is)
2162{
2163 struct ext4_xattr_ibody_header *header;
2164 struct ext4_inode *raw_inode;
2165 int error;
2166
2167 if (EXT4_I(inode)->i_extra_isize == 0)
2168 return 0;
2169 raw_inode = ext4_raw_inode(&is->iloc);
2170 header = IHDR(inode, raw_inode);
2171 is->s.base = is->s.first = IFIRST(header);
2172 is->s.here = is->s.first;
2173 is->s.end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
2174 if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
2175 error = xattr_check_inode(inode, header, is->s.end);
2176 if (error)
2177 return error;
2178 /* Find the named attribute. */
2179 error = xattr_find_entry(inode, &is->s.here, is->s.end,
2180 i->name_index, i->name, 0);
2181 if (error && error != -ENODATA)
2182 return error;
2183 is->s.not_found = error;
2184 }
2185 return 0;
2186}
2187
2188int ext4_xattr_ibody_inline_set(handle_t *handle, struct inode *inode,
2189 struct ext4_xattr_info *i,
2190 struct ext4_xattr_ibody_find *is)
2191{
2192 struct ext4_xattr_ibody_header *header;
2193 struct ext4_xattr_search *s = &is->s;
2194 int error;
2195
2196 if (EXT4_I(inode)->i_extra_isize == 0)
2197 return -ENOSPC;
2198 error = ext4_xattr_set_entry(i, s, handle, inode, false /* is_block */);
2199 if (error)
2200 return error;
2201 header = IHDR(inode, ext4_raw_inode(&is->iloc));
2202 if (!IS_LAST_ENTRY(s->first)) {
2203 header->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
2204 ext4_set_inode_state(inode, EXT4_STATE_XATTR);
2205 } else {
2206 header->h_magic = cpu_to_le32(0);
2207 ext4_clear_inode_state(inode, EXT4_STATE_XATTR);
2208 }
2209 return 0;
2210}
2211
2212static int ext4_xattr_ibody_set(handle_t *handle, struct inode *inode,
2213 struct ext4_xattr_info *i,
2214 struct ext4_xattr_ibody_find *is)
2215{
2216 struct ext4_xattr_ibody_header *header;
2217 struct ext4_xattr_search *s = &is->s;
2218 int error;
2219
2220 if (EXT4_I(inode)->i_extra_isize == 0)
2221 return -ENOSPC;
2222 error = ext4_xattr_set_entry(i, s, handle, inode, false /* is_block */);
2223 if (error)
2224 return error;
2225 header = IHDR(inode, ext4_raw_inode(&is->iloc));
2226 if (!IS_LAST_ENTRY(s->first)) {
2227 header->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
2228 ext4_set_inode_state(inode, EXT4_STATE_XATTR);
2229 } else {
2230 header->h_magic = cpu_to_le32(0);
2231 ext4_clear_inode_state(inode, EXT4_STATE_XATTR);
2232 }
2233 return 0;
2234}
2235
2236static int ext4_xattr_value_same(struct ext4_xattr_search *s,
2237 struct ext4_xattr_info *i)
2238{
2239 void *value;
2240
2241 /* When e_value_inum is set the value is stored externally. */
2242 if (s->here->e_value_inum)
2243 return 0;
2244 if (le32_to_cpu(s->here->e_value_size) != i->value_len)
2245 return 0;
2246 value = ((void *)s->base) + le16_to_cpu(s->here->e_value_offs);
2247 return !memcmp(value, i->value, i->value_len);
2248}
2249
2250static struct buffer_head *ext4_xattr_get_block(struct inode *inode)
2251{
2252 struct buffer_head *bh;
2253 int error;
2254
2255 if (!EXT4_I(inode)->i_file_acl)
2256 return NULL;
2257 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
2258 if (IS_ERR(bh))
2259 return bh;
2260 error = ext4_xattr_check_block(inode, bh);
2261 if (error) {
2262 brelse(bh);
2263 return ERR_PTR(error);
2264 }
2265 return bh;
2266}
2267
2268/*
2269 * ext4_xattr_set_handle()
2270 *
2271 * Create, replace or remove an extended attribute for this inode. Value
2272 * is NULL to remove an existing extended attribute, and non-NULL to
2273 * either replace an existing extended attribute, or create a new extended
2274 * attribute. The flags XATTR_REPLACE and XATTR_CREATE
2275 * specify that an extended attribute must exist and must not exist
2276 * previous to the call, respectively.
2277 *
2278 * Returns 0, or a negative error number on failure.
2279 */
2280int
2281ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
2282 const char *name, const void *value, size_t value_len,
2283 int flags)
2284{
2285 struct ext4_xattr_info i = {
2286 .name_index = name_index,
2287 .name = name,
2288 .value = value,
2289 .value_len = value_len,
2290 .in_inode = 0,
2291 };
2292 struct ext4_xattr_ibody_find is = {
2293 .s = { .not_found = -ENODATA, },
2294 };
2295 struct ext4_xattr_block_find bs = {
2296 .s = { .not_found = -ENODATA, },
2297 };
2298 int no_expand;
2299 int error;
2300
2301 if (!name)
2302 return -EINVAL;
2303 if (strlen(name) > 255)
2304 return -ERANGE;
2305
2306 ext4_write_lock_xattr(inode, &no_expand);
2307
2308 /* Check journal credits under write lock. */
2309 if (ext4_handle_valid(handle)) {
2310 struct buffer_head *bh;
2311 int credits;
2312
2313 bh = ext4_xattr_get_block(inode);
2314 if (IS_ERR(bh)) {
2315 error = PTR_ERR(bh);
2316 goto cleanup;
2317 }
2318
2319 credits = __ext4_xattr_set_credits(inode->i_sb, inode, bh,
2320 value_len,
2321 flags & XATTR_CREATE);
2322 brelse(bh);
2323
2324 if (jbd2_handle_buffer_credits(handle) < credits) {
2325 error = -ENOSPC;
2326 goto cleanup;
2327 }
2328 }
2329
2330 error = ext4_reserve_inode_write(handle, inode, &is.iloc);
2331 if (error)
2332 goto cleanup;
2333
2334 if (ext4_test_inode_state(inode, EXT4_STATE_NEW)) {
2335 struct ext4_inode *raw_inode = ext4_raw_inode(&is.iloc);
2336 memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size);
2337 ext4_clear_inode_state(inode, EXT4_STATE_NEW);
2338 }
2339
2340 error = ext4_xattr_ibody_find(inode, &i, &is);
2341 if (error)
2342 goto cleanup;
2343 if (is.s.not_found)
2344 error = ext4_xattr_block_find(inode, &i, &bs);
2345 if (error)
2346 goto cleanup;
2347 if (is.s.not_found && bs.s.not_found) {
2348 error = -ENODATA;
2349 if (flags & XATTR_REPLACE)
2350 goto cleanup;
2351 error = 0;
2352 if (!value)
2353 goto cleanup;
2354 } else {
2355 error = -EEXIST;
2356 if (flags & XATTR_CREATE)
2357 goto cleanup;
2358 }
2359
2360 if (!value) {
2361 if (!is.s.not_found)
2362 error = ext4_xattr_ibody_set(handle, inode, &i, &is);
2363 else if (!bs.s.not_found)
2364 error = ext4_xattr_block_set(handle, inode, &i, &bs);
2365 } else {
2366 error = 0;
2367 /* Xattr value did not change? Save us some work and bail out */
2368 if (!is.s.not_found && ext4_xattr_value_same(&is.s, &i))
2369 goto cleanup;
2370 if (!bs.s.not_found && ext4_xattr_value_same(&bs.s, &i))
2371 goto cleanup;
2372
2373 if (ext4_has_feature_ea_inode(inode->i_sb) &&
2374 (EXT4_XATTR_SIZE(i.value_len) >
2375 EXT4_XATTR_MIN_LARGE_EA_SIZE(inode->i_sb->s_blocksize)))
2376 i.in_inode = 1;
2377retry_inode:
2378 error = ext4_xattr_ibody_set(handle, inode, &i, &is);
2379 if (!error && !bs.s.not_found) {
2380 i.value = NULL;
2381 error = ext4_xattr_block_set(handle, inode, &i, &bs);
2382 } else if (error == -ENOSPC) {
2383 if (EXT4_I(inode)->i_file_acl && !bs.s.base) {
2384 brelse(bs.bh);
2385 bs.bh = NULL;
2386 error = ext4_xattr_block_find(inode, &i, &bs);
2387 if (error)
2388 goto cleanup;
2389 }
2390 error = ext4_xattr_block_set(handle, inode, &i, &bs);
2391 if (!error && !is.s.not_found) {
2392 i.value = NULL;
2393 error = ext4_xattr_ibody_set(handle, inode, &i,
2394 &is);
2395 } else if (error == -ENOSPC) {
2396 /*
2397 * Xattr does not fit in the block, store at
2398 * external inode if possible.
2399 */
2400 if (ext4_has_feature_ea_inode(inode->i_sb) &&
2401 !i.in_inode) {
2402 i.in_inode = 1;
2403 goto retry_inode;
2404 }
2405 }
2406 }
2407 }
2408 if (!error) {
2409 ext4_xattr_update_super_block(handle, inode->i_sb);
2410 inode->i_ctime = current_time(inode);
2411 if (!value)
2412 no_expand = 0;
2413 error = ext4_mark_iloc_dirty(handle, inode, &is.iloc);
2414 /*
2415 * The bh is consumed by ext4_mark_iloc_dirty, even with
2416 * error != 0.
2417 */
2418 is.iloc.bh = NULL;
2419 if (IS_SYNC(inode))
2420 ext4_handle_sync(handle);
2421 }
2422
2423cleanup:
2424 brelse(is.iloc.bh);
2425 brelse(bs.bh);
2426 ext4_write_unlock_xattr(inode, &no_expand);
2427 return error;
2428}
2429
2430int ext4_xattr_set_credits(struct inode *inode, size_t value_len,
2431 bool is_create, int *credits)
2432{
2433 struct buffer_head *bh;
2434 int err;
2435
2436 *credits = 0;
2437
2438 if (!EXT4_SB(inode->i_sb)->s_journal)
2439 return 0;
2440
2441 down_read(&EXT4_I(inode)->xattr_sem);
2442
2443 bh = ext4_xattr_get_block(inode);
2444 if (IS_ERR(bh)) {
2445 err = PTR_ERR(bh);
2446 } else {
2447 *credits = __ext4_xattr_set_credits(inode->i_sb, inode, bh,
2448 value_len, is_create);
2449 brelse(bh);
2450 err = 0;
2451 }
2452
2453 up_read(&EXT4_I(inode)->xattr_sem);
2454 return err;
2455}
2456
2457/*
2458 * ext4_xattr_set()
2459 *
2460 * Like ext4_xattr_set_handle, but start from an inode. This extended
2461 * attribute modification is a filesystem transaction by itself.
2462 *
2463 * Returns 0, or a negative error number on failure.
2464 */
2465int
2466ext4_xattr_set(struct inode *inode, int name_index, const char *name,
2467 const void *value, size_t value_len, int flags)
2468{
2469 handle_t *handle;
2470 struct super_block *sb = inode->i_sb;
2471 int error, retries = 0;
2472 int credits;
2473
2474 error = dquot_initialize(inode);
2475 if (error)
2476 return error;
2477
2478retry:
2479 error = ext4_xattr_set_credits(inode, value_len, flags & XATTR_CREATE,
2480 &credits);
2481 if (error)
2482 return error;
2483
2484 handle = ext4_journal_start(inode, EXT4_HT_XATTR, credits);
2485 if (IS_ERR(handle)) {
2486 error = PTR_ERR(handle);
2487 } else {
2488 int error2;
2489
2490 error = ext4_xattr_set_handle(handle, inode, name_index, name,
2491 value, value_len, flags);
2492 error2 = ext4_journal_stop(handle);
2493 if (error == -ENOSPC &&
2494 ext4_should_retry_alloc(sb, &retries))
2495 goto retry;
2496 if (error == 0)
2497 error = error2;
2498 }
2499
2500 return error;
2501}
2502
2503/*
2504 * Shift the EA entries in the inode to create space for the increased
2505 * i_extra_isize.
2506 */
2507static void ext4_xattr_shift_entries(struct ext4_xattr_entry *entry,
2508 int value_offs_shift, void *to,
2509 void *from, size_t n)
2510{
2511 struct ext4_xattr_entry *last = entry;
2512 int new_offs;
2513
2514 /* We always shift xattr headers further thus offsets get lower */
2515 BUG_ON(value_offs_shift > 0);
2516
2517 /* Adjust the value offsets of the entries */
2518 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
2519 if (!last->e_value_inum && last->e_value_size) {
2520 new_offs = le16_to_cpu(last->e_value_offs) +
2521 value_offs_shift;
2522 last->e_value_offs = cpu_to_le16(new_offs);
2523 }
2524 }
2525 /* Shift the entries by n bytes */
2526 memmove(to, from, n);
2527}
2528
2529/*
2530 * Move xattr pointed to by 'entry' from inode into external xattr block
2531 */
2532static int ext4_xattr_move_to_block(handle_t *handle, struct inode *inode,
2533 struct ext4_inode *raw_inode,
2534 struct ext4_xattr_entry *entry)
2535{
2536 struct ext4_xattr_ibody_find *is = NULL;
2537 struct ext4_xattr_block_find *bs = NULL;
2538 char *buffer = NULL, *b_entry_name = NULL;
2539 size_t value_size = le32_to_cpu(entry->e_value_size);
2540 struct ext4_xattr_info i = {
2541 .value = NULL,
2542 .value_len = 0,
2543 .name_index = entry->e_name_index,
2544 .in_inode = !!entry->e_value_inum,
2545 };
2546 struct ext4_xattr_ibody_header *header = IHDR(inode, raw_inode);
2547 int error;
2548
2549 is = kzalloc(sizeof(struct ext4_xattr_ibody_find), GFP_NOFS);
2550 bs = kzalloc(sizeof(struct ext4_xattr_block_find), GFP_NOFS);
2551 buffer = kmalloc(value_size, GFP_NOFS);
2552 b_entry_name = kmalloc(entry->e_name_len + 1, GFP_NOFS);
2553 if (!is || !bs || !buffer || !b_entry_name) {
2554 error = -ENOMEM;
2555 goto out;
2556 }
2557
2558 is->s.not_found = -ENODATA;
2559 bs->s.not_found = -ENODATA;
2560 is->iloc.bh = NULL;
2561 bs->bh = NULL;
2562
2563 /* Save the entry name and the entry value */
2564 if (entry->e_value_inum) {
2565 error = ext4_xattr_inode_get(inode, entry, buffer, value_size);
2566 if (error)
2567 goto out;
2568 } else {
2569 size_t value_offs = le16_to_cpu(entry->e_value_offs);
2570 memcpy(buffer, (void *)IFIRST(header) + value_offs, value_size);
2571 }
2572
2573 memcpy(b_entry_name, entry->e_name, entry->e_name_len);
2574 b_entry_name[entry->e_name_len] = '\0';
2575 i.name = b_entry_name;
2576
2577 error = ext4_get_inode_loc(inode, &is->iloc);
2578 if (error)
2579 goto out;
2580
2581 error = ext4_xattr_ibody_find(inode, &i, is);
2582 if (error)
2583 goto out;
2584
2585 /* Remove the chosen entry from the inode */
2586 error = ext4_xattr_ibody_set(handle, inode, &i, is);
2587 if (error)
2588 goto out;
2589
2590 i.value = buffer;
2591 i.value_len = value_size;
2592 error = ext4_xattr_block_find(inode, &i, bs);
2593 if (error)
2594 goto out;
2595
2596 /* Add entry which was removed from the inode into the block */
2597 error = ext4_xattr_block_set(handle, inode, &i, bs);
2598 if (error)
2599 goto out;
2600 error = 0;
2601out:
2602 kfree(b_entry_name);
2603 kfree(buffer);
2604 if (is)
2605 brelse(is->iloc.bh);
2606 if (bs)
2607 brelse(bs->bh);
2608 kfree(is);
2609 kfree(bs);
2610
2611 return error;
2612}
2613
2614static int ext4_xattr_make_inode_space(handle_t *handle, struct inode *inode,
2615 struct ext4_inode *raw_inode,
2616 int isize_diff, size_t ifree,
2617 size_t bfree, int *total_ino)
2618{
2619 struct ext4_xattr_ibody_header *header = IHDR(inode, raw_inode);
2620 struct ext4_xattr_entry *small_entry;
2621 struct ext4_xattr_entry *entry;
2622 struct ext4_xattr_entry *last;
2623 unsigned int entry_size; /* EA entry size */
2624 unsigned int total_size; /* EA entry size + value size */
2625 unsigned int min_total_size;
2626 int error;
2627
2628 while (isize_diff > ifree) {
2629 entry = NULL;
2630 small_entry = NULL;
2631 min_total_size = ~0U;
2632 last = IFIRST(header);
2633 /* Find the entry best suited to be pushed into EA block */
2634 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
2635 /* never move system.data out of the inode */
2636 if ((last->e_name_len == 4) &&
2637 (last->e_name_index == EXT4_XATTR_INDEX_SYSTEM) &&
2638 !memcmp(last->e_name, "data", 4))
2639 continue;
2640 total_size = EXT4_XATTR_LEN(last->e_name_len);
2641 if (!last->e_value_inum)
2642 total_size += EXT4_XATTR_SIZE(
2643 le32_to_cpu(last->e_value_size));
2644 if (total_size <= bfree &&
2645 total_size < min_total_size) {
2646 if (total_size + ifree < isize_diff) {
2647 small_entry = last;
2648 } else {
2649 entry = last;
2650 min_total_size = total_size;
2651 }
2652 }
2653 }
2654
2655 if (entry == NULL) {
2656 if (small_entry == NULL)
2657 return -ENOSPC;
2658 entry = small_entry;
2659 }
2660
2661 entry_size = EXT4_XATTR_LEN(entry->e_name_len);
2662 total_size = entry_size;
2663 if (!entry->e_value_inum)
2664 total_size += EXT4_XATTR_SIZE(
2665 le32_to_cpu(entry->e_value_size));
2666 error = ext4_xattr_move_to_block(handle, inode, raw_inode,
2667 entry);
2668 if (error)
2669 return error;
2670
2671 *total_ino -= entry_size;
2672 ifree += total_size;
2673 bfree -= total_size;
2674 }
2675
2676 return 0;
2677}
2678
2679/*
2680 * Expand an inode by new_extra_isize bytes when EAs are present.
2681 * Returns 0 on success or negative error number on failure.
2682 */
2683int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
2684 struct ext4_inode *raw_inode, handle_t *handle)
2685{
2686 struct ext4_xattr_ibody_header *header;
2687 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2688 static unsigned int mnt_count;
2689 size_t min_offs;
2690 size_t ifree, bfree;
2691 int total_ino;
2692 void *base, *end;
2693 int error = 0, tried_min_extra_isize = 0;
2694 int s_min_extra_isize = le16_to_cpu(sbi->s_es->s_min_extra_isize);
2695 int isize_diff; /* How much do we need to grow i_extra_isize */
2696
2697retry:
2698 isize_diff = new_extra_isize - EXT4_I(inode)->i_extra_isize;
2699 if (EXT4_I(inode)->i_extra_isize >= new_extra_isize)
2700 return 0;
2701
2702 header = IHDR(inode, raw_inode);
2703
2704 /*
2705 * Check if enough free space is available in the inode to shift the
2706 * entries ahead by new_extra_isize.
2707 */
2708
2709 base = IFIRST(header);
2710 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
2711 min_offs = end - base;
2712 total_ino = sizeof(struct ext4_xattr_ibody_header) + sizeof(u32);
2713
2714 error = xattr_check_inode(inode, header, end);
2715 if (error)
2716 goto cleanup;
2717
2718 ifree = ext4_xattr_free_space(base, &min_offs, base, &total_ino);
2719 if (ifree >= isize_diff)
2720 goto shift;
2721
2722 /*
2723 * Enough free space isn't available in the inode, check if
2724 * EA block can hold new_extra_isize bytes.
2725 */
2726 if (EXT4_I(inode)->i_file_acl) {
2727 struct buffer_head *bh;
2728
2729 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
2730 if (IS_ERR(bh)) {
2731 error = PTR_ERR(bh);
2732 goto cleanup;
2733 }
2734 error = ext4_xattr_check_block(inode, bh);
2735 if (error) {
2736 brelse(bh);
2737 goto cleanup;
2738 }
2739 base = BHDR(bh);
2740 end = bh->b_data + bh->b_size;
2741 min_offs = end - base;
2742 bfree = ext4_xattr_free_space(BFIRST(bh), &min_offs, base,
2743 NULL);
2744 brelse(bh);
2745 if (bfree + ifree < isize_diff) {
2746 if (!tried_min_extra_isize && s_min_extra_isize) {
2747 tried_min_extra_isize++;
2748 new_extra_isize = s_min_extra_isize;
2749 goto retry;
2750 }
2751 error = -ENOSPC;
2752 goto cleanup;
2753 }
2754 } else {
2755 bfree = inode->i_sb->s_blocksize;
2756 }
2757
2758 error = ext4_xattr_make_inode_space(handle, inode, raw_inode,
2759 isize_diff, ifree, bfree,
2760 &total_ino);
2761 if (error) {
2762 if (error == -ENOSPC && !tried_min_extra_isize &&
2763 s_min_extra_isize) {
2764 tried_min_extra_isize++;
2765 new_extra_isize = s_min_extra_isize;
2766 goto retry;
2767 }
2768 goto cleanup;
2769 }
2770shift:
2771 /* Adjust the offsets and shift the remaining entries ahead */
2772 ext4_xattr_shift_entries(IFIRST(header), EXT4_I(inode)->i_extra_isize
2773 - new_extra_isize, (void *)raw_inode +
2774 EXT4_GOOD_OLD_INODE_SIZE + new_extra_isize,
2775 (void *)header, total_ino);
2776 EXT4_I(inode)->i_extra_isize = new_extra_isize;
2777
2778cleanup:
2779 if (error && (mnt_count != le16_to_cpu(sbi->s_es->s_mnt_count))) {
2780 ext4_warning(inode->i_sb, "Unable to expand inode %lu. Delete some EAs or run e2fsck.",
2781 inode->i_ino);
2782 mnt_count = le16_to_cpu(sbi->s_es->s_mnt_count);
2783 }
2784 return error;
2785}
2786
2787#define EIA_INCR 16 /* must be 2^n */
2788#define EIA_MASK (EIA_INCR - 1)
2789
2790/* Add the large xattr @inode into @ea_inode_array for deferred iput().
2791 * If @ea_inode_array is new or full it will be grown and the old
2792 * contents copied over.
2793 */
2794static int
2795ext4_expand_inode_array(struct ext4_xattr_inode_array **ea_inode_array,
2796 struct inode *inode)
2797{
2798 if (*ea_inode_array == NULL) {
2799 /*
2800 * Start with 15 inodes, so it fits into a power-of-two size.
2801 * If *ea_inode_array is NULL, this is essentially offsetof()
2802 */
2803 (*ea_inode_array) =
2804 kmalloc(offsetof(struct ext4_xattr_inode_array,
2805 inodes[EIA_MASK]),
2806 GFP_NOFS);
2807 if (*ea_inode_array == NULL)
2808 return -ENOMEM;
2809 (*ea_inode_array)->count = 0;
2810 } else if (((*ea_inode_array)->count & EIA_MASK) == EIA_MASK) {
2811 /* expand the array once all 15 + n * 16 slots are full */
2812 struct ext4_xattr_inode_array *new_array = NULL;
2813 int count = (*ea_inode_array)->count;
2814
2815 /* if new_array is NULL, this is essentially offsetof() */
2816 new_array = kmalloc(
2817 offsetof(struct ext4_xattr_inode_array,
2818 inodes[count + EIA_INCR]),
2819 GFP_NOFS);
2820 if (new_array == NULL)
2821 return -ENOMEM;
2822 memcpy(new_array, *ea_inode_array,
2823 offsetof(struct ext4_xattr_inode_array, inodes[count]));
2824 kfree(*ea_inode_array);
2825 *ea_inode_array = new_array;
2826 }
2827 (*ea_inode_array)->inodes[(*ea_inode_array)->count++] = inode;
2828 return 0;
2829}
2830
2831/*
2832 * ext4_xattr_delete_inode()
2833 *
2834 * Free extended attribute resources associated with this inode. Traverse
2835 * all entries and decrement reference on any xattr inodes associated with this
2836 * inode. This is called immediately before an inode is freed. We have exclusive
2837 * access to the inode. If an orphan inode is deleted it will also release its
2838 * references on xattr block and xattr inodes.
2839 */
2840int ext4_xattr_delete_inode(handle_t *handle, struct inode *inode,
2841 struct ext4_xattr_inode_array **ea_inode_array,
2842 int extra_credits)
2843{
2844 struct buffer_head *bh = NULL;
2845 struct ext4_xattr_ibody_header *header;
2846 struct ext4_iloc iloc = { .bh = NULL };
2847 struct ext4_xattr_entry *entry;
2848 struct inode *ea_inode;
2849 int error;
2850
2851 error = ext4_journal_ensure_credits(handle, extra_credits,
2852 ext4_free_metadata_revoke_credits(inode->i_sb, 1));
2853 if (error < 0) {
2854 EXT4_ERROR_INODE(inode, "ensure credits (error %d)", error);
2855 goto cleanup;
2856 }
2857
2858 if (ext4_has_feature_ea_inode(inode->i_sb) &&
2859 ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
2860
2861 error = ext4_get_inode_loc(inode, &iloc);
2862 if (error) {
2863 EXT4_ERROR_INODE(inode, "inode loc (error %d)", error);
2864 goto cleanup;
2865 }
2866
2867 error = ext4_journal_get_write_access(handle, iloc.bh);
2868 if (error) {
2869 EXT4_ERROR_INODE(inode, "write access (error %d)",
2870 error);
2871 goto cleanup;
2872 }
2873
2874 header = IHDR(inode, ext4_raw_inode(&iloc));
2875 if (header->h_magic == cpu_to_le32(EXT4_XATTR_MAGIC))
2876 ext4_xattr_inode_dec_ref_all(handle, inode, iloc.bh,
2877 IFIRST(header),
2878 false /* block_csum */,
2879 ea_inode_array,
2880 extra_credits,
2881 false /* skip_quota */);
2882 }
2883
2884 if (EXT4_I(inode)->i_file_acl) {
2885 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
2886 if (IS_ERR(bh)) {
2887 error = PTR_ERR(bh);
2888 if (error == -EIO) {
2889 EXT4_ERROR_INODE_ERR(inode, EIO,
2890 "block %llu read error",
2891 EXT4_I(inode)->i_file_acl);
2892 }
2893 bh = NULL;
2894 goto cleanup;
2895 }
2896 error = ext4_xattr_check_block(inode, bh);
2897 if (error)
2898 goto cleanup;
2899
2900 if (ext4_has_feature_ea_inode(inode->i_sb)) {
2901 for (entry = BFIRST(bh); !IS_LAST_ENTRY(entry);
2902 entry = EXT4_XATTR_NEXT(entry)) {
2903 if (!entry->e_value_inum)
2904 continue;
2905 error = ext4_xattr_inode_iget(inode,
2906 le32_to_cpu(entry->e_value_inum),
2907 le32_to_cpu(entry->e_hash),
2908 &ea_inode);
2909 if (error)
2910 continue;
2911 ext4_xattr_inode_free_quota(inode, ea_inode,
2912 le32_to_cpu(entry->e_value_size));
2913 iput(ea_inode);
2914 }
2915
2916 }
2917
2918 ext4_xattr_release_block(handle, inode, bh, ea_inode_array,
2919 extra_credits);
2920 /*
2921 * Update i_file_acl value in the same transaction that releases
2922 * block.
2923 */
2924 EXT4_I(inode)->i_file_acl = 0;
2925 error = ext4_mark_inode_dirty(handle, inode);
2926 if (error) {
2927 EXT4_ERROR_INODE(inode, "mark inode dirty (error %d)",
2928 error);
2929 goto cleanup;
2930 }
2931 }
2932 error = 0;
2933cleanup:
2934 brelse(iloc.bh);
2935 brelse(bh);
2936 return error;
2937}
2938
2939void ext4_xattr_inode_array_free(struct ext4_xattr_inode_array *ea_inode_array)
2940{
2941 int idx;
2942
2943 if (ea_inode_array == NULL)
2944 return;
2945
2946 for (idx = 0; idx < ea_inode_array->count; ++idx)
2947 iput(ea_inode_array->inodes[idx]);
2948 kfree(ea_inode_array);
2949}
2950
2951/*
2952 * ext4_xattr_block_cache_insert()
2953 *
2954 * Create a new entry in the extended attribute block cache, and insert
2955 * it unless such an entry is already in the cache.
2956 *
2957 * Returns 0, or a negative error number on failure.
2958 */
2959static void
2960ext4_xattr_block_cache_insert(struct mb_cache *ea_block_cache,
2961 struct buffer_head *bh)
2962{
2963 struct ext4_xattr_header *header = BHDR(bh);
2964 __u32 hash = le32_to_cpu(header->h_hash);
2965 int reusable = le32_to_cpu(header->h_refcount) <
2966 EXT4_XATTR_REFCOUNT_MAX;
2967 int error;
2968
2969 if (!ea_block_cache)
2970 return;
2971 error = mb_cache_entry_create(ea_block_cache, GFP_NOFS, hash,
2972 bh->b_blocknr, reusable);
2973 if (error) {
2974 if (error == -EBUSY)
2975 ea_bdebug(bh, "already in cache");
2976 } else
2977 ea_bdebug(bh, "inserting [%x]", (int)hash);
2978}
2979
2980/*
2981 * ext4_xattr_cmp()
2982 *
2983 * Compare two extended attribute blocks for equality.
2984 *
2985 * Returns 0 if the blocks are equal, 1 if they differ, and
2986 * a negative error number on errors.
2987 */
2988static int
2989ext4_xattr_cmp(struct ext4_xattr_header *header1,
2990 struct ext4_xattr_header *header2)
2991{
2992 struct ext4_xattr_entry *entry1, *entry2;
2993
2994 entry1 = ENTRY(header1+1);
2995 entry2 = ENTRY(header2+1);
2996 while (!IS_LAST_ENTRY(entry1)) {
2997 if (IS_LAST_ENTRY(entry2))
2998 return 1;
2999 if (entry1->e_hash != entry2->e_hash ||
3000 entry1->e_name_index != entry2->e_name_index ||
3001 entry1->e_name_len != entry2->e_name_len ||
3002 entry1->e_value_size != entry2->e_value_size ||
3003 entry1->e_value_inum != entry2->e_value_inum ||
3004 memcmp(entry1->e_name, entry2->e_name, entry1->e_name_len))
3005 return 1;
3006 if (!entry1->e_value_inum &&
3007 memcmp((char *)header1 + le16_to_cpu(entry1->e_value_offs),
3008 (char *)header2 + le16_to_cpu(entry2->e_value_offs),
3009 le32_to_cpu(entry1->e_value_size)))
3010 return 1;
3011
3012 entry1 = EXT4_XATTR_NEXT(entry1);
3013 entry2 = EXT4_XATTR_NEXT(entry2);
3014 }
3015 if (!IS_LAST_ENTRY(entry2))
3016 return 1;
3017 return 0;
3018}
3019
3020/*
3021 * ext4_xattr_block_cache_find()
3022 *
3023 * Find an identical extended attribute block.
3024 *
3025 * Returns a pointer to the block found, or NULL if such a block was
3026 * not found or an error occurred.
3027 */
3028static struct buffer_head *
3029ext4_xattr_block_cache_find(struct inode *inode,
3030 struct ext4_xattr_header *header,
3031 struct mb_cache_entry **pce)
3032{
3033 __u32 hash = le32_to_cpu(header->h_hash);
3034 struct mb_cache_entry *ce;
3035 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
3036
3037 if (!ea_block_cache)
3038 return NULL;
3039 if (!header->h_hash)
3040 return NULL; /* never share */
3041 ea_idebug(inode, "looking for cached blocks [%x]", (int)hash);
3042 ce = mb_cache_entry_find_first(ea_block_cache, hash);
3043 while (ce) {
3044 struct buffer_head *bh;
3045
3046 bh = ext4_sb_bread(inode->i_sb, ce->e_value, REQ_PRIO);
3047 if (IS_ERR(bh)) {
3048 if (PTR_ERR(bh) == -ENOMEM)
3049 return NULL;
3050 bh = NULL;
3051 EXT4_ERROR_INODE(inode, "block %lu read error",
3052 (unsigned long)ce->e_value);
3053 } else if (ext4_xattr_cmp(header, BHDR(bh)) == 0) {
3054 *pce = ce;
3055 return bh;
3056 }
3057 brelse(bh);
3058 ce = mb_cache_entry_find_next(ea_block_cache, ce);
3059 }
3060 return NULL;
3061}
3062
3063#define NAME_HASH_SHIFT 5
3064#define VALUE_HASH_SHIFT 16
3065
3066/*
3067 * ext4_xattr_hash_entry()
3068 *
3069 * Compute the hash of an extended attribute.
3070 */
3071static __le32 ext4_xattr_hash_entry(char *name, size_t name_len, __le32 *value,
3072 size_t value_count)
3073{
3074 __u32 hash = 0;
3075
3076 while (name_len--) {
3077 hash = (hash << NAME_HASH_SHIFT) ^
3078 (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^
3079 *name++;
3080 }
3081 while (value_count--) {
3082 hash = (hash << VALUE_HASH_SHIFT) ^
3083 (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^
3084 le32_to_cpu(*value++);
3085 }
3086 return cpu_to_le32(hash);
3087}
3088
3089#undef NAME_HASH_SHIFT
3090#undef VALUE_HASH_SHIFT
3091
3092#define BLOCK_HASH_SHIFT 16
3093
3094/*
3095 * ext4_xattr_rehash()
3096 *
3097 * Re-compute the extended attribute hash value after an entry has changed.
3098 */
3099static void ext4_xattr_rehash(struct ext4_xattr_header *header)
3100{
3101 struct ext4_xattr_entry *here;
3102 __u32 hash = 0;
3103
3104 here = ENTRY(header+1);
3105 while (!IS_LAST_ENTRY(here)) {
3106 if (!here->e_hash) {
3107 /* Block is not shared if an entry's hash value == 0 */
3108 hash = 0;
3109 break;
3110 }
3111 hash = (hash << BLOCK_HASH_SHIFT) ^
3112 (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^
3113 le32_to_cpu(here->e_hash);
3114 here = EXT4_XATTR_NEXT(here);
3115 }
3116 header->h_hash = cpu_to_le32(hash);
3117}
3118
3119#undef BLOCK_HASH_SHIFT
3120
3121#define HASH_BUCKET_BITS 10
3122
3123struct mb_cache *
3124ext4_xattr_create_cache(void)
3125{
3126 return mb_cache_create(HASH_BUCKET_BITS);
3127}
3128
3129void ext4_xattr_destroy_cache(struct mb_cache *cache)
3130{
3131 if (cache)
3132 mb_cache_destroy(cache);
3133}
3134