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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};
97
98const struct xattr_handler *ext4_xattr_handlers[] = {
99 &ext4_xattr_user_handler,
100 &ext4_xattr_trusted_handler,
101#ifdef CONFIG_EXT4_FS_POSIX_ACL
102 &posix_acl_access_xattr_handler,
103 &posix_acl_default_xattr_handler,
104#endif
105#ifdef CONFIG_EXT4_FS_SECURITY
106 &ext4_xattr_security_handler,
107#endif
108 NULL
109};
110
111#define EA_BLOCK_CACHE(inode) (((struct ext4_sb_info *) \
112 inode->i_sb->s_fs_info)->s_ea_block_cache)
113
114#define EA_INODE_CACHE(inode) (((struct ext4_sb_info *) \
115 inode->i_sb->s_fs_info)->s_ea_inode_cache)
116
117static int
118ext4_expand_inode_array(struct ext4_xattr_inode_array **ea_inode_array,
119 struct inode *inode);
120
121#ifdef CONFIG_LOCKDEP
122void ext4_xattr_inode_set_class(struct inode *ea_inode)
123{
124 lockdep_set_subclass(&ea_inode->i_rwsem, 1);
125}
126#endif
127
128static __le32 ext4_xattr_block_csum(struct inode *inode,
129 sector_t block_nr,
130 struct ext4_xattr_header *hdr)
131{
132 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
133 __u32 csum;
134 __le64 dsk_block_nr = cpu_to_le64(block_nr);
135 __u32 dummy_csum = 0;
136 int offset = offsetof(struct ext4_xattr_header, h_checksum);
137
138 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&dsk_block_nr,
139 sizeof(dsk_block_nr));
140 csum = ext4_chksum(sbi, csum, (__u8 *)hdr, offset);
141 csum = ext4_chksum(sbi, csum, (__u8 *)&dummy_csum, sizeof(dummy_csum));
142 offset += sizeof(dummy_csum);
143 csum = ext4_chksum(sbi, csum, (__u8 *)hdr + offset,
144 EXT4_BLOCK_SIZE(inode->i_sb) - offset);
145
146 return cpu_to_le32(csum);
147}
148
149static int ext4_xattr_block_csum_verify(struct inode *inode,
150 struct buffer_head *bh)
151{
152 struct ext4_xattr_header *hdr = BHDR(bh);
153 int ret = 1;
154
155 if (ext4_has_metadata_csum(inode->i_sb)) {
156 lock_buffer(bh);
157 ret = (hdr->h_checksum == ext4_xattr_block_csum(inode,
158 bh->b_blocknr, hdr));
159 unlock_buffer(bh);
160 }
161 return ret;
162}
163
164static void ext4_xattr_block_csum_set(struct inode *inode,
165 struct buffer_head *bh)
166{
167 if (ext4_has_metadata_csum(inode->i_sb))
168 BHDR(bh)->h_checksum = ext4_xattr_block_csum(inode,
169 bh->b_blocknr, BHDR(bh));
170}
171
172static inline const struct xattr_handler *
173ext4_xattr_handler(int name_index)
174{
175 const struct xattr_handler *handler = NULL;
176
177 if (name_index > 0 && name_index < ARRAY_SIZE(ext4_xattr_handler_map))
178 handler = ext4_xattr_handler_map[name_index];
179 return handler;
180}
181
182static int
183ext4_xattr_check_entries(struct ext4_xattr_entry *entry, void *end,
184 void *value_start)
185{
186 struct ext4_xattr_entry *e = entry;
187
188 /* Find the end of the names list */
189 while (!IS_LAST_ENTRY(e)) {
190 struct ext4_xattr_entry *next = EXT4_XATTR_NEXT(e);
191 if ((void *)next >= end)
192 return -EFSCORRUPTED;
193 if (strnlen(e->e_name, e->e_name_len) != e->e_name_len)
194 return -EFSCORRUPTED;
195 e = next;
196 }
197
198 /* Check the values */
199 while (!IS_LAST_ENTRY(entry)) {
200 u32 size = le32_to_cpu(entry->e_value_size);
201
202 if (size > EXT4_XATTR_SIZE_MAX)
203 return -EFSCORRUPTED;
204
205 if (size != 0 && entry->e_value_inum == 0) {
206 u16 offs = le16_to_cpu(entry->e_value_offs);
207 void *value;
208
209 /*
210 * The value cannot overlap the names, and the value
211 * with padding cannot extend beyond 'end'. Check both
212 * the padded and unpadded sizes, since the size may
213 * overflow to 0 when adding padding.
214 */
215 if (offs > end - value_start)
216 return -EFSCORRUPTED;
217 value = value_start + offs;
218 if (value < (void *)e + sizeof(u32) ||
219 size > end - value ||
220 EXT4_XATTR_SIZE(size) > end - value)
221 return -EFSCORRUPTED;
222 }
223 entry = EXT4_XATTR_NEXT(entry);
224 }
225
226 return 0;
227}
228
229static inline int
230__ext4_xattr_check_block(struct inode *inode, struct buffer_head *bh,
231 const char *function, unsigned int line)
232{
233 int error = -EFSCORRUPTED;
234
235 if (BHDR(bh)->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC) ||
236 BHDR(bh)->h_blocks != cpu_to_le32(1))
237 goto errout;
238 if (buffer_verified(bh))
239 return 0;
240
241 error = -EFSBADCRC;
242 if (!ext4_xattr_block_csum_verify(inode, bh))
243 goto errout;
244 error = ext4_xattr_check_entries(BFIRST(bh), bh->b_data + bh->b_size,
245 bh->b_data);
246errout:
247 if (error)
248 __ext4_error_inode(inode, function, line, 0,
249 "corrupted xattr block %llu",
250 (unsigned long long) bh->b_blocknr);
251 else
252 set_buffer_verified(bh);
253 return error;
254}
255
256#define ext4_xattr_check_block(inode, bh) \
257 __ext4_xattr_check_block((inode), (bh), __func__, __LINE__)
258
259
260static int
261__xattr_check_inode(struct inode *inode, struct ext4_xattr_ibody_header *header,
262 void *end, const char *function, unsigned int line)
263{
264 int error = -EFSCORRUPTED;
265
266 if (end - (void *)header < sizeof(*header) + sizeof(u32) ||
267 (header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC)))
268 goto errout;
269 error = ext4_xattr_check_entries(IFIRST(header), end, IFIRST(header));
270errout:
271 if (error)
272 __ext4_error_inode(inode, function, line, 0,
273 "corrupted in-inode xattr");
274 return error;
275}
276
277#define xattr_check_inode(inode, header, end) \
278 __xattr_check_inode((inode), (header), (end), __func__, __LINE__)
279
280static int
281xattr_find_entry(struct inode *inode, struct ext4_xattr_entry **pentry,
282 void *end, int name_index, const char *name, int sorted)
283{
284 struct ext4_xattr_entry *entry, *next;
285 size_t name_len;
286 int cmp = 1;
287
288 if (name == NULL)
289 return -EINVAL;
290 name_len = strlen(name);
291 for (entry = *pentry; !IS_LAST_ENTRY(entry); entry = next) {
292 next = EXT4_XATTR_NEXT(entry);
293 if ((void *) next >= end) {
294 EXT4_ERROR_INODE(inode, "corrupted xattr entries");
295 return -EFSCORRUPTED;
296 }
297 cmp = name_index - entry->e_name_index;
298 if (!cmp)
299 cmp = name_len - entry->e_name_len;
300 if (!cmp)
301 cmp = memcmp(name, entry->e_name, name_len);
302 if (cmp <= 0 && (sorted || cmp == 0))
303 break;
304 }
305 *pentry = entry;
306 return cmp ? -ENODATA : 0;
307}
308
309static u32
310ext4_xattr_inode_hash(struct ext4_sb_info *sbi, const void *buffer, size_t size)
311{
312 return ext4_chksum(sbi, sbi->s_csum_seed, buffer, size);
313}
314
315static u64 ext4_xattr_inode_get_ref(struct inode *ea_inode)
316{
317 return ((u64)ea_inode->i_ctime.tv_sec << 32) |
318 (u32) inode_peek_iversion_raw(ea_inode);
319}
320
321static void ext4_xattr_inode_set_ref(struct inode *ea_inode, u64 ref_count)
322{
323 ea_inode->i_ctime.tv_sec = (u32)(ref_count >> 32);
324 inode_set_iversion_raw(ea_inode, ref_count & 0xffffffff);
325}
326
327static u32 ext4_xattr_inode_get_hash(struct inode *ea_inode)
328{
329 return (u32)ea_inode->i_atime.tv_sec;
330}
331
332static void ext4_xattr_inode_set_hash(struct inode *ea_inode, u32 hash)
333{
334 ea_inode->i_atime.tv_sec = hash;
335}
336
337/*
338 * Read the EA value from an inode.
339 */
340static int ext4_xattr_inode_read(struct inode *ea_inode, void *buf, size_t size)
341{
342 int blocksize = 1 << ea_inode->i_blkbits;
343 int bh_count = (size + blocksize - 1) >> ea_inode->i_blkbits;
344 int tail_size = (size % blocksize) ?: blocksize;
345 struct buffer_head *bhs_inline[8];
346 struct buffer_head **bhs = bhs_inline;
347 int i, ret;
348
349 if (bh_count > ARRAY_SIZE(bhs_inline)) {
350 bhs = kmalloc_array(bh_count, sizeof(*bhs), GFP_NOFS);
351 if (!bhs)
352 return -ENOMEM;
353 }
354
355 ret = ext4_bread_batch(ea_inode, 0 /* block */, bh_count,
356 true /* wait */, bhs);
357 if (ret)
358 goto free_bhs;
359
360 for (i = 0; i < bh_count; i++) {
361 /* There shouldn't be any holes in ea_inode. */
362 if (!bhs[i]) {
363 ret = -EFSCORRUPTED;
364 goto put_bhs;
365 }
366 memcpy((char *)buf + blocksize * i, bhs[i]->b_data,
367 i < bh_count - 1 ? blocksize : tail_size);
368 }
369 ret = 0;
370put_bhs:
371 for (i = 0; i < bh_count; i++)
372 brelse(bhs[i]);
373free_bhs:
374 if (bhs != bhs_inline)
375 kfree(bhs);
376 return ret;
377}
378
379#define EXT4_XATTR_INODE_GET_PARENT(inode) ((__u32)(inode)->i_mtime.tv_sec)
380
381static int ext4_xattr_inode_iget(struct inode *parent, unsigned long ea_ino,
382 u32 ea_inode_hash, struct inode **ea_inode)
383{
384 struct inode *inode;
385 int err;
386
387 inode = ext4_iget(parent->i_sb, ea_ino, EXT4_IGET_NORMAL);
388 if (IS_ERR(inode)) {
389 err = PTR_ERR(inode);
390 ext4_error(parent->i_sb,
391 "error while reading EA inode %lu err=%d", ea_ino,
392 err);
393 return err;
394 }
395
396 if (is_bad_inode(inode)) {
397 ext4_error(parent->i_sb,
398 "error while reading EA inode %lu is_bad_inode",
399 ea_ino);
400 err = -EIO;
401 goto error;
402 }
403
404 if (!(EXT4_I(inode)->i_flags & EXT4_EA_INODE_FL)) {
405 ext4_error(parent->i_sb,
406 "EA inode %lu does not have EXT4_EA_INODE_FL flag",
407 ea_ino);
408 err = -EINVAL;
409 goto error;
410 }
411
412 ext4_xattr_inode_set_class(inode);
413
414 /*
415 * Check whether this is an old Lustre-style xattr inode. Lustre
416 * implementation does not have hash validation, rather it has a
417 * backpointer from ea_inode to the parent inode.
418 */
419 if (ea_inode_hash != ext4_xattr_inode_get_hash(inode) &&
420 EXT4_XATTR_INODE_GET_PARENT(inode) == parent->i_ino &&
421 inode->i_generation == parent->i_generation) {
422 ext4_set_inode_state(inode, EXT4_STATE_LUSTRE_EA_INODE);
423 ext4_xattr_inode_set_ref(inode, 1);
424 } else {
425 inode_lock(inode);
426 inode->i_flags |= S_NOQUOTA;
427 inode_unlock(inode);
428 }
429
430 *ea_inode = inode;
431 return 0;
432error:
433 iput(inode);
434 return err;
435}
436
437static int
438ext4_xattr_inode_verify_hashes(struct inode *ea_inode,
439 struct ext4_xattr_entry *entry, void *buffer,
440 size_t size)
441{
442 u32 hash;
443
444 /* Verify stored hash matches calculated hash. */
445 hash = ext4_xattr_inode_hash(EXT4_SB(ea_inode->i_sb), buffer, size);
446 if (hash != ext4_xattr_inode_get_hash(ea_inode))
447 return -EFSCORRUPTED;
448
449 if (entry) {
450 __le32 e_hash, tmp_data;
451
452 /* Verify entry hash. */
453 tmp_data = cpu_to_le32(hash);
454 e_hash = ext4_xattr_hash_entry(entry->e_name, entry->e_name_len,
455 &tmp_data, 1);
456 if (e_hash != entry->e_hash)
457 return -EFSCORRUPTED;
458 }
459 return 0;
460}
461
462/*
463 * Read xattr value from the EA inode.
464 */
465static int
466ext4_xattr_inode_get(struct inode *inode, struct ext4_xattr_entry *entry,
467 void *buffer, size_t size)
468{
469 struct mb_cache *ea_inode_cache = EA_INODE_CACHE(inode);
470 struct inode *ea_inode;
471 int err;
472
473 err = ext4_xattr_inode_iget(inode, le32_to_cpu(entry->e_value_inum),
474 le32_to_cpu(entry->e_hash), &ea_inode);
475 if (err) {
476 ea_inode = NULL;
477 goto out;
478 }
479
480 if (i_size_read(ea_inode) != size) {
481 ext4_warning_inode(ea_inode,
482 "ea_inode file size=%llu entry size=%zu",
483 i_size_read(ea_inode), size);
484 err = -EFSCORRUPTED;
485 goto out;
486 }
487
488 err = ext4_xattr_inode_read(ea_inode, buffer, size);
489 if (err)
490 goto out;
491
492 if (!ext4_test_inode_state(ea_inode, EXT4_STATE_LUSTRE_EA_INODE)) {
493 err = ext4_xattr_inode_verify_hashes(ea_inode, entry, buffer,
494 size);
495 if (err) {
496 ext4_warning_inode(ea_inode,
497 "EA inode hash validation failed");
498 goto out;
499 }
500
501 if (ea_inode_cache)
502 mb_cache_entry_create(ea_inode_cache, GFP_NOFS,
503 ext4_xattr_inode_get_hash(ea_inode),
504 ea_inode->i_ino, true /* reusable */);
505 }
506out:
507 iput(ea_inode);
508 return err;
509}
510
511static int
512ext4_xattr_block_get(struct inode *inode, int name_index, const char *name,
513 void *buffer, size_t buffer_size)
514{
515 struct buffer_head *bh = NULL;
516 struct ext4_xattr_entry *entry;
517 size_t size;
518 void *end;
519 int error;
520 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
521
522 ea_idebug(inode, "name=%d.%s, buffer=%p, buffer_size=%ld",
523 name_index, name, buffer, (long)buffer_size);
524
525 if (!EXT4_I(inode)->i_file_acl)
526 return -ENODATA;
527 ea_idebug(inode, "reading block %llu",
528 (unsigned long long)EXT4_I(inode)->i_file_acl);
529 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
530 if (IS_ERR(bh))
531 return PTR_ERR(bh);
532 ea_bdebug(bh, "b_count=%d, refcount=%d",
533 atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount));
534 error = ext4_xattr_check_block(inode, bh);
535 if (error)
536 goto cleanup;
537 ext4_xattr_block_cache_insert(ea_block_cache, bh);
538 entry = BFIRST(bh);
539 end = bh->b_data + bh->b_size;
540 error = xattr_find_entry(inode, &entry, end, name_index, name, 1);
541 if (error)
542 goto cleanup;
543 size = le32_to_cpu(entry->e_value_size);
544 error = -ERANGE;
545 if (unlikely(size > EXT4_XATTR_SIZE_MAX))
546 goto cleanup;
547 if (buffer) {
548 if (size > buffer_size)
549 goto cleanup;
550 if (entry->e_value_inum) {
551 error = ext4_xattr_inode_get(inode, entry, buffer,
552 size);
553 if (error)
554 goto cleanup;
555 } else {
556 u16 offset = le16_to_cpu(entry->e_value_offs);
557 void *p = bh->b_data + offset;
558
559 if (unlikely(p + size > end))
560 goto cleanup;
561 memcpy(buffer, p, size);
562 }
563 }
564 error = size;
565
566cleanup:
567 brelse(bh);
568 return error;
569}
570
571int
572ext4_xattr_ibody_get(struct inode *inode, int name_index, const char *name,
573 void *buffer, size_t buffer_size)
574{
575 struct ext4_xattr_ibody_header *header;
576 struct ext4_xattr_entry *entry;
577 struct ext4_inode *raw_inode;
578 struct ext4_iloc iloc;
579 size_t size;
580 void *end;
581 int error;
582
583 if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR))
584 return -ENODATA;
585 error = ext4_get_inode_loc(inode, &iloc);
586 if (error)
587 return error;
588 raw_inode = ext4_raw_inode(&iloc);
589 header = IHDR(inode, raw_inode);
590 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
591 error = xattr_check_inode(inode, header, end);
592 if (error)
593 goto cleanup;
594 entry = IFIRST(header);
595 error = xattr_find_entry(inode, &entry, end, name_index, name, 0);
596 if (error)
597 goto cleanup;
598 size = le32_to_cpu(entry->e_value_size);
599 error = -ERANGE;
600 if (unlikely(size > EXT4_XATTR_SIZE_MAX))
601 goto cleanup;
602 if (buffer) {
603 if (size > buffer_size)
604 goto cleanup;
605 if (entry->e_value_inum) {
606 error = ext4_xattr_inode_get(inode, entry, buffer,
607 size);
608 if (error)
609 goto cleanup;
610 } else {
611 u16 offset = le16_to_cpu(entry->e_value_offs);
612 void *p = (void *)IFIRST(header) + offset;
613
614 if (unlikely(p + size > end))
615 goto cleanup;
616 memcpy(buffer, p, size);
617 }
618 }
619 error = size;
620
621cleanup:
622 brelse(iloc.bh);
623 return error;
624}
625
626/*
627 * ext4_xattr_get()
628 *
629 * Copy an extended attribute into the buffer
630 * provided, or compute the buffer size required.
631 * Buffer is NULL to compute the size of the buffer required.
632 *
633 * Returns a negative error number on failure, or the number of bytes
634 * used / required on success.
635 */
636int
637ext4_xattr_get(struct inode *inode, int name_index, const char *name,
638 void *buffer, size_t buffer_size)
639{
640 int error;
641
642 if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
643 return -EIO;
644
645 if (strlen(name) > 255)
646 return -ERANGE;
647
648 down_read(&EXT4_I(inode)->xattr_sem);
649 error = ext4_xattr_ibody_get(inode, name_index, name, buffer,
650 buffer_size);
651 if (error == -ENODATA)
652 error = ext4_xattr_block_get(inode, name_index, name, buffer,
653 buffer_size);
654 up_read(&EXT4_I(inode)->xattr_sem);
655 return error;
656}
657
658static int
659ext4_xattr_list_entries(struct dentry *dentry, struct ext4_xattr_entry *entry,
660 char *buffer, size_t buffer_size)
661{
662 size_t rest = buffer_size;
663
664 for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) {
665 const struct xattr_handler *handler =
666 ext4_xattr_handler(entry->e_name_index);
667
668 if (handler && (!handler->list || handler->list(dentry))) {
669 const char *prefix = handler->prefix ?: handler->name;
670 size_t prefix_len = strlen(prefix);
671 size_t size = prefix_len + entry->e_name_len + 1;
672
673 if (buffer) {
674 if (size > rest)
675 return -ERANGE;
676 memcpy(buffer, prefix, prefix_len);
677 buffer += prefix_len;
678 memcpy(buffer, entry->e_name, entry->e_name_len);
679 buffer += entry->e_name_len;
680 *buffer++ = 0;
681 }
682 rest -= size;
683 }
684 }
685 return buffer_size - rest; /* total size */
686}
687
688static int
689ext4_xattr_block_list(struct dentry *dentry, char *buffer, size_t buffer_size)
690{
691 struct inode *inode = d_inode(dentry);
692 struct buffer_head *bh = NULL;
693 int error;
694
695 ea_idebug(inode, "buffer=%p, buffer_size=%ld",
696 buffer, (long)buffer_size);
697
698 if (!EXT4_I(inode)->i_file_acl)
699 return 0;
700 ea_idebug(inode, "reading block %llu",
701 (unsigned long long)EXT4_I(inode)->i_file_acl);
702 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
703 if (IS_ERR(bh))
704 return PTR_ERR(bh);
705 ea_bdebug(bh, "b_count=%d, refcount=%d",
706 atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount));
707 error = ext4_xattr_check_block(inode, bh);
708 if (error)
709 goto cleanup;
710 ext4_xattr_block_cache_insert(EA_BLOCK_CACHE(inode), bh);
711 error = ext4_xattr_list_entries(dentry, BFIRST(bh), buffer,
712 buffer_size);
713cleanup:
714 brelse(bh);
715 return error;
716}
717
718static int
719ext4_xattr_ibody_list(struct dentry *dentry, char *buffer, size_t buffer_size)
720{
721 struct inode *inode = d_inode(dentry);
722 struct ext4_xattr_ibody_header *header;
723 struct ext4_inode *raw_inode;
724 struct ext4_iloc iloc;
725 void *end;
726 int error;
727
728 if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR))
729 return 0;
730 error = ext4_get_inode_loc(inode, &iloc);
731 if (error)
732 return error;
733 raw_inode = ext4_raw_inode(&iloc);
734 header = IHDR(inode, raw_inode);
735 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
736 error = xattr_check_inode(inode, header, end);
737 if (error)
738 goto cleanup;
739 error = ext4_xattr_list_entries(dentry, IFIRST(header),
740 buffer, buffer_size);
741
742cleanup:
743 brelse(iloc.bh);
744 return error;
745}
746
747/*
748 * Inode operation listxattr()
749 *
750 * d_inode(dentry)->i_rwsem: don't care
751 *
752 * Copy a list of attribute names into the buffer
753 * provided, or compute the buffer size required.
754 * Buffer is NULL to compute the size of the buffer required.
755 *
756 * Returns a negative error number on failure, or the number of bytes
757 * used / required on success.
758 */
759ssize_t
760ext4_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
761{
762 int ret, ret2;
763
764 down_read(&EXT4_I(d_inode(dentry))->xattr_sem);
765 ret = ret2 = ext4_xattr_ibody_list(dentry, buffer, buffer_size);
766 if (ret < 0)
767 goto errout;
768 if (buffer) {
769 buffer += ret;
770 buffer_size -= ret;
771 }
772 ret = ext4_xattr_block_list(dentry, buffer, buffer_size);
773 if (ret < 0)
774 goto errout;
775 ret += ret2;
776errout:
777 up_read(&EXT4_I(d_inode(dentry))->xattr_sem);
778 return ret;
779}
780
781/*
782 * If the EXT4_FEATURE_COMPAT_EXT_ATTR feature of this file system is
783 * not set, set it.
784 */
785static void ext4_xattr_update_super_block(handle_t *handle,
786 struct super_block *sb)
787{
788 if (ext4_has_feature_xattr(sb))
789 return;
790
791 BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access");
792 if (ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh) == 0) {
793 ext4_set_feature_xattr(sb);
794 ext4_handle_dirty_super(handle, sb);
795 }
796}
797
798int ext4_get_inode_usage(struct inode *inode, qsize_t *usage)
799{
800 struct ext4_iloc iloc = { .bh = NULL };
801 struct buffer_head *bh = NULL;
802 struct ext4_inode *raw_inode;
803 struct ext4_xattr_ibody_header *header;
804 struct ext4_xattr_entry *entry;
805 qsize_t ea_inode_refs = 0;
806 void *end;
807 int ret;
808
809 lockdep_assert_held_read(&EXT4_I(inode)->xattr_sem);
810
811 if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
812 ret = ext4_get_inode_loc(inode, &iloc);
813 if (ret)
814 goto out;
815 raw_inode = ext4_raw_inode(&iloc);
816 header = IHDR(inode, raw_inode);
817 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
818 ret = xattr_check_inode(inode, header, end);
819 if (ret)
820 goto out;
821
822 for (entry = IFIRST(header); !IS_LAST_ENTRY(entry);
823 entry = EXT4_XATTR_NEXT(entry))
824 if (entry->e_value_inum)
825 ea_inode_refs++;
826 }
827
828 if (EXT4_I(inode)->i_file_acl) {
829 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
830 if (IS_ERR(bh)) {
831 ret = PTR_ERR(bh);
832 bh = NULL;
833 goto out;
834 }
835
836 ret = ext4_xattr_check_block(inode, bh);
837 if (ret)
838 goto out;
839
840 for (entry = BFIRST(bh); !IS_LAST_ENTRY(entry);
841 entry = EXT4_XATTR_NEXT(entry))
842 if (entry->e_value_inum)
843 ea_inode_refs++;
844 }
845 *usage = ea_inode_refs + 1;
846 ret = 0;
847out:
848 brelse(iloc.bh);
849 brelse(bh);
850 return ret;
851}
852
853static inline size_t round_up_cluster(struct inode *inode, size_t length)
854{
855 struct super_block *sb = inode->i_sb;
856 size_t cluster_size = 1 << (EXT4_SB(sb)->s_cluster_bits +
857 inode->i_blkbits);
858 size_t mask = ~(cluster_size - 1);
859
860 return (length + cluster_size - 1) & mask;
861}
862
863static int ext4_xattr_inode_alloc_quota(struct inode *inode, size_t len)
864{
865 int err;
866
867 err = dquot_alloc_inode(inode);
868 if (err)
869 return err;
870 err = dquot_alloc_space_nodirty(inode, round_up_cluster(inode, len));
871 if (err)
872 dquot_free_inode(inode);
873 return err;
874}
875
876static void ext4_xattr_inode_free_quota(struct inode *parent,
877 struct inode *ea_inode,
878 size_t len)
879{
880 if (ea_inode &&
881 ext4_test_inode_state(ea_inode, EXT4_STATE_LUSTRE_EA_INODE))
882 return;
883 dquot_free_space_nodirty(parent, round_up_cluster(parent, len));
884 dquot_free_inode(parent);
885}
886
887int __ext4_xattr_set_credits(struct super_block *sb, struct inode *inode,
888 struct buffer_head *block_bh, size_t value_len,
889 bool is_create)
890{
891 int credits;
892 int blocks;
893
894 /*
895 * 1) Owner inode update
896 * 2) Ref count update on old xattr block
897 * 3) new xattr block
898 * 4) block bitmap update for new xattr block
899 * 5) group descriptor for new xattr block
900 * 6) block bitmap update for old xattr block
901 * 7) group descriptor for old block
902 *
903 * 6 & 7 can happen if we have two racing threads T_a and T_b
904 * which are each trying to set an xattr on inodes I_a and I_b
905 * which were both initially sharing an xattr block.
906 */
907 credits = 7;
908
909 /* Quota updates. */
910 credits += EXT4_MAXQUOTAS_TRANS_BLOCKS(sb);
911
912 /*
913 * In case of inline data, we may push out the data to a block,
914 * so we need to reserve credits for this eventuality
915 */
916 if (inode && ext4_has_inline_data(inode))
917 credits += ext4_writepage_trans_blocks(inode) + 1;
918
919 /* We are done if ea_inode feature is not enabled. */
920 if (!ext4_has_feature_ea_inode(sb))
921 return credits;
922
923 /* New ea_inode, inode map, block bitmap, group descriptor. */
924 credits += 4;
925
926 /* Data blocks. */
927 blocks = (value_len + sb->s_blocksize - 1) >> sb->s_blocksize_bits;
928
929 /* Indirection block or one level of extent tree. */
930 blocks += 1;
931
932 /* Block bitmap and group descriptor updates for each block. */
933 credits += blocks * 2;
934
935 /* Blocks themselves. */
936 credits += blocks;
937
938 if (!is_create) {
939 /* Dereference ea_inode holding old xattr value.
940 * Old ea_inode, inode map, block bitmap, group descriptor.
941 */
942 credits += 4;
943
944 /* Data blocks for old ea_inode. */
945 blocks = XATTR_SIZE_MAX >> sb->s_blocksize_bits;
946
947 /* Indirection block or one level of extent tree for old
948 * ea_inode.
949 */
950 blocks += 1;
951
952 /* Block bitmap and group descriptor updates for each block. */
953 credits += blocks * 2;
954 }
955
956 /* We may need to clone the existing xattr block in which case we need
957 * to increment ref counts for existing ea_inodes referenced by it.
958 */
959 if (block_bh) {
960 struct ext4_xattr_entry *entry = BFIRST(block_bh);
961
962 for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry))
963 if (entry->e_value_inum)
964 /* Ref count update on ea_inode. */
965 credits += 1;
966 }
967 return credits;
968}
969
970static int ext4_xattr_ensure_credits(handle_t *handle, struct inode *inode,
971 int credits, struct buffer_head *bh,
972 bool dirty, bool block_csum)
973{
974 int error;
975
976 if (!ext4_handle_valid(handle))
977 return 0;
978
979 if (handle->h_buffer_credits >= credits)
980 return 0;
981
982 error = ext4_journal_extend(handle, credits - handle->h_buffer_credits);
983 if (!error)
984 return 0;
985 if (error < 0) {
986 ext4_warning(inode->i_sb, "Extend journal (error %d)", error);
987 return error;
988 }
989
990 if (bh && dirty) {
991 if (block_csum)
992 ext4_xattr_block_csum_set(inode, bh);
993 error = ext4_handle_dirty_metadata(handle, NULL, bh);
994 if (error) {
995 ext4_warning(inode->i_sb, "Handle metadata (error %d)",
996 error);
997 return error;
998 }
999 }
1000
1001 error = ext4_journal_restart(handle, credits);
1002 if (error) {
1003 ext4_warning(inode->i_sb, "Restart journal (error %d)", error);
1004 return error;
1005 }
1006
1007 if (bh) {
1008 error = ext4_journal_get_write_access(handle, bh);
1009 if (error) {
1010 ext4_warning(inode->i_sb,
1011 "Get write access failed (error %d)",
1012 error);
1013 return error;
1014 }
1015 }
1016 return 0;
1017}
1018
1019static int ext4_xattr_inode_update_ref(handle_t *handle, struct inode *ea_inode,
1020 int ref_change)
1021{
1022 struct mb_cache *ea_inode_cache = EA_INODE_CACHE(ea_inode);
1023 struct ext4_iloc iloc;
1024 s64 ref_count;
1025 u32 hash;
1026 int ret;
1027
1028 inode_lock(ea_inode);
1029
1030 ret = ext4_reserve_inode_write(handle, ea_inode, &iloc);
1031 if (ret)
1032 goto out;
1033
1034 ref_count = ext4_xattr_inode_get_ref(ea_inode);
1035 ref_count += ref_change;
1036 ext4_xattr_inode_set_ref(ea_inode, ref_count);
1037
1038 if (ref_change > 0) {
1039 WARN_ONCE(ref_count <= 0, "EA inode %lu ref_count=%lld",
1040 ea_inode->i_ino, ref_count);
1041
1042 if (ref_count == 1) {
1043 WARN_ONCE(ea_inode->i_nlink, "EA inode %lu i_nlink=%u",
1044 ea_inode->i_ino, ea_inode->i_nlink);
1045
1046 set_nlink(ea_inode, 1);
1047 ext4_orphan_del(handle, ea_inode);
1048
1049 if (ea_inode_cache) {
1050 hash = ext4_xattr_inode_get_hash(ea_inode);
1051 mb_cache_entry_create(ea_inode_cache,
1052 GFP_NOFS, hash,
1053 ea_inode->i_ino,
1054 true /* reusable */);
1055 }
1056 }
1057 } else {
1058 WARN_ONCE(ref_count < 0, "EA inode %lu ref_count=%lld",
1059 ea_inode->i_ino, ref_count);
1060
1061 if (ref_count == 0) {
1062 WARN_ONCE(ea_inode->i_nlink != 1,
1063 "EA inode %lu i_nlink=%u",
1064 ea_inode->i_ino, ea_inode->i_nlink);
1065
1066 clear_nlink(ea_inode);
1067 ext4_orphan_add(handle, ea_inode);
1068
1069 if (ea_inode_cache) {
1070 hash = ext4_xattr_inode_get_hash(ea_inode);
1071 mb_cache_entry_delete(ea_inode_cache, hash,
1072 ea_inode->i_ino);
1073 }
1074 }
1075 }
1076
1077 ret = ext4_mark_iloc_dirty(handle, ea_inode, &iloc);
1078 if (ret)
1079 ext4_warning_inode(ea_inode,
1080 "ext4_mark_iloc_dirty() failed ret=%d", ret);
1081out:
1082 inode_unlock(ea_inode);
1083 return ret;
1084}
1085
1086static int ext4_xattr_inode_inc_ref(handle_t *handle, struct inode *ea_inode)
1087{
1088 return ext4_xattr_inode_update_ref(handle, ea_inode, 1);
1089}
1090
1091static int ext4_xattr_inode_dec_ref(handle_t *handle, struct inode *ea_inode)
1092{
1093 return ext4_xattr_inode_update_ref(handle, ea_inode, -1);
1094}
1095
1096static int ext4_xattr_inode_inc_ref_all(handle_t *handle, struct inode *parent,
1097 struct ext4_xattr_entry *first)
1098{
1099 struct inode *ea_inode;
1100 struct ext4_xattr_entry *entry;
1101 struct ext4_xattr_entry *failed_entry;
1102 unsigned int ea_ino;
1103 int err, saved_err;
1104
1105 for (entry = first; !IS_LAST_ENTRY(entry);
1106 entry = EXT4_XATTR_NEXT(entry)) {
1107 if (!entry->e_value_inum)
1108 continue;
1109 ea_ino = le32_to_cpu(entry->e_value_inum);
1110 err = ext4_xattr_inode_iget(parent, ea_ino,
1111 le32_to_cpu(entry->e_hash),
1112 &ea_inode);
1113 if (err)
1114 goto cleanup;
1115 err = ext4_xattr_inode_inc_ref(handle, ea_inode);
1116 if (err) {
1117 ext4_warning_inode(ea_inode, "inc ref error %d", err);
1118 iput(ea_inode);
1119 goto cleanup;
1120 }
1121 iput(ea_inode);
1122 }
1123 return 0;
1124
1125cleanup:
1126 saved_err = err;
1127 failed_entry = entry;
1128
1129 for (entry = first; entry != failed_entry;
1130 entry = EXT4_XATTR_NEXT(entry)) {
1131 if (!entry->e_value_inum)
1132 continue;
1133 ea_ino = le32_to_cpu(entry->e_value_inum);
1134 err = ext4_xattr_inode_iget(parent, ea_ino,
1135 le32_to_cpu(entry->e_hash),
1136 &ea_inode);
1137 if (err) {
1138 ext4_warning(parent->i_sb,
1139 "cleanup ea_ino %u iget error %d", ea_ino,
1140 err);
1141 continue;
1142 }
1143 err = ext4_xattr_inode_dec_ref(handle, ea_inode);
1144 if (err)
1145 ext4_warning_inode(ea_inode, "cleanup dec ref error %d",
1146 err);
1147 iput(ea_inode);
1148 }
1149 return saved_err;
1150}
1151
1152static void
1153ext4_xattr_inode_dec_ref_all(handle_t *handle, struct inode *parent,
1154 struct buffer_head *bh,
1155 struct ext4_xattr_entry *first, bool block_csum,
1156 struct ext4_xattr_inode_array **ea_inode_array,
1157 int extra_credits, bool skip_quota)
1158{
1159 struct inode *ea_inode;
1160 struct ext4_xattr_entry *entry;
1161 bool dirty = false;
1162 unsigned int ea_ino;
1163 int err;
1164 int credits;
1165
1166 /* One credit for dec ref on ea_inode, one for orphan list addition, */
1167 credits = 2 + extra_credits;
1168
1169 for (entry = first; !IS_LAST_ENTRY(entry);
1170 entry = EXT4_XATTR_NEXT(entry)) {
1171 if (!entry->e_value_inum)
1172 continue;
1173 ea_ino = le32_to_cpu(entry->e_value_inum);
1174 err = ext4_xattr_inode_iget(parent, ea_ino,
1175 le32_to_cpu(entry->e_hash),
1176 &ea_inode);
1177 if (err)
1178 continue;
1179
1180 err = ext4_expand_inode_array(ea_inode_array, ea_inode);
1181 if (err) {
1182 ext4_warning_inode(ea_inode,
1183 "Expand inode array err=%d", err);
1184 iput(ea_inode);
1185 continue;
1186 }
1187
1188 err = ext4_xattr_ensure_credits(handle, parent, credits, bh,
1189 dirty, block_csum);
1190 if (err) {
1191 ext4_warning_inode(ea_inode, "Ensure credits err=%d",
1192 err);
1193 continue;
1194 }
1195
1196 err = ext4_xattr_inode_dec_ref(handle, ea_inode);
1197 if (err) {
1198 ext4_warning_inode(ea_inode, "ea_inode dec ref err=%d",
1199 err);
1200 continue;
1201 }
1202
1203 if (!skip_quota)
1204 ext4_xattr_inode_free_quota(parent, ea_inode,
1205 le32_to_cpu(entry->e_value_size));
1206
1207 /*
1208 * Forget about ea_inode within the same transaction that
1209 * decrements the ref count. This avoids duplicate decrements in
1210 * case the rest of the work spills over to subsequent
1211 * transactions.
1212 */
1213 entry->e_value_inum = 0;
1214 entry->e_value_size = 0;
1215
1216 dirty = true;
1217 }
1218
1219 if (dirty) {
1220 /*
1221 * Note that we are deliberately skipping csum calculation for
1222 * the final update because we do not expect any journal
1223 * restarts until xattr block is freed.
1224 */
1225
1226 err = ext4_handle_dirty_metadata(handle, NULL, bh);
1227 if (err)
1228 ext4_warning_inode(parent,
1229 "handle dirty metadata err=%d", err);
1230 }
1231}
1232
1233/*
1234 * Release the xattr block BH: If the reference count is > 1, decrement it;
1235 * otherwise free the block.
1236 */
1237static void
1238ext4_xattr_release_block(handle_t *handle, struct inode *inode,
1239 struct buffer_head *bh,
1240 struct ext4_xattr_inode_array **ea_inode_array,
1241 int extra_credits)
1242{
1243 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
1244 u32 hash, ref;
1245 int error = 0;
1246
1247 BUFFER_TRACE(bh, "get_write_access");
1248 error = ext4_journal_get_write_access(handle, bh);
1249 if (error)
1250 goto out;
1251
1252 lock_buffer(bh);
1253 hash = le32_to_cpu(BHDR(bh)->h_hash);
1254 ref = le32_to_cpu(BHDR(bh)->h_refcount);
1255 if (ref == 1) {
1256 ea_bdebug(bh, "refcount now=0; freeing");
1257 /*
1258 * This must happen under buffer lock for
1259 * ext4_xattr_block_set() to reliably detect freed block
1260 */
1261 if (ea_block_cache)
1262 mb_cache_entry_delete(ea_block_cache, hash,
1263 bh->b_blocknr);
1264 get_bh(bh);
1265 unlock_buffer(bh);
1266
1267 if (ext4_has_feature_ea_inode(inode->i_sb))
1268 ext4_xattr_inode_dec_ref_all(handle, inode, bh,
1269 BFIRST(bh),
1270 true /* block_csum */,
1271 ea_inode_array,
1272 extra_credits,
1273 true /* skip_quota */);
1274 ext4_free_blocks(handle, inode, bh, 0, 1,
1275 EXT4_FREE_BLOCKS_METADATA |
1276 EXT4_FREE_BLOCKS_FORGET);
1277 } else {
1278 ref--;
1279 BHDR(bh)->h_refcount = cpu_to_le32(ref);
1280 if (ref == EXT4_XATTR_REFCOUNT_MAX - 1) {
1281 struct mb_cache_entry *ce;
1282
1283 if (ea_block_cache) {
1284 ce = mb_cache_entry_get(ea_block_cache, hash,
1285 bh->b_blocknr);
1286 if (ce) {
1287 ce->e_reusable = 1;
1288 mb_cache_entry_put(ea_block_cache, ce);
1289 }
1290 }
1291 }
1292
1293 ext4_xattr_block_csum_set(inode, bh);
1294 /*
1295 * Beware of this ugliness: Releasing of xattr block references
1296 * from different inodes can race and so we have to protect
1297 * from a race where someone else frees the block (and releases
1298 * its journal_head) before we are done dirtying the buffer. In
1299 * nojournal mode this race is harmless and we actually cannot
1300 * call ext4_handle_dirty_metadata() with locked buffer as
1301 * that function can call sync_dirty_buffer() so for that case
1302 * we handle the dirtying after unlocking the buffer.
1303 */
1304 if (ext4_handle_valid(handle))
1305 error = ext4_handle_dirty_metadata(handle, inode, bh);
1306 unlock_buffer(bh);
1307 if (!ext4_handle_valid(handle))
1308 error = ext4_handle_dirty_metadata(handle, inode, bh);
1309 if (IS_SYNC(inode))
1310 ext4_handle_sync(handle);
1311 dquot_free_block(inode, EXT4_C2B(EXT4_SB(inode->i_sb), 1));
1312 ea_bdebug(bh, "refcount now=%d; releasing",
1313 le32_to_cpu(BHDR(bh)->h_refcount));
1314 }
1315out:
1316 ext4_std_error(inode->i_sb, error);
1317 return;
1318}
1319
1320/*
1321 * Find the available free space for EAs. This also returns the total number of
1322 * bytes used by EA entries.
1323 */
1324static size_t ext4_xattr_free_space(struct ext4_xattr_entry *last,
1325 size_t *min_offs, void *base, int *total)
1326{
1327 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
1328 if (!last->e_value_inum && last->e_value_size) {
1329 size_t offs = le16_to_cpu(last->e_value_offs);
1330 if (offs < *min_offs)
1331 *min_offs = offs;
1332 }
1333 if (total)
1334 *total += EXT4_XATTR_LEN(last->e_name_len);
1335 }
1336 return (*min_offs - ((void *)last - base) - sizeof(__u32));
1337}
1338
1339/*
1340 * Write the value of the EA in an inode.
1341 */
1342static int ext4_xattr_inode_write(handle_t *handle, struct inode *ea_inode,
1343 const void *buf, int bufsize)
1344{
1345 struct buffer_head *bh = NULL;
1346 unsigned long block = 0;
1347 int blocksize = ea_inode->i_sb->s_blocksize;
1348 int max_blocks = (bufsize + blocksize - 1) >> ea_inode->i_blkbits;
1349 int csize, wsize = 0;
1350 int ret = 0;
1351 int retries = 0;
1352
1353retry:
1354 while (ret >= 0 && ret < max_blocks) {
1355 struct ext4_map_blocks map;
1356 map.m_lblk = block += ret;
1357 map.m_len = max_blocks -= ret;
1358
1359 ret = ext4_map_blocks(handle, ea_inode, &map,
1360 EXT4_GET_BLOCKS_CREATE);
1361 if (ret <= 0) {
1362 ext4_mark_inode_dirty(handle, ea_inode);
1363 if (ret == -ENOSPC &&
1364 ext4_should_retry_alloc(ea_inode->i_sb, &retries)) {
1365 ret = 0;
1366 goto retry;
1367 }
1368 break;
1369 }
1370 }
1371
1372 if (ret < 0)
1373 return ret;
1374
1375 block = 0;
1376 while (wsize < bufsize) {
1377 if (bh != NULL)
1378 brelse(bh);
1379 csize = (bufsize - wsize) > blocksize ? blocksize :
1380 bufsize - wsize;
1381 bh = ext4_getblk(handle, ea_inode, block, 0);
1382 if (IS_ERR(bh))
1383 return PTR_ERR(bh);
1384 if (!bh) {
1385 WARN_ON_ONCE(1);
1386 EXT4_ERROR_INODE(ea_inode,
1387 "ext4_getblk() return bh = NULL");
1388 return -EFSCORRUPTED;
1389 }
1390 ret = ext4_journal_get_write_access(handle, bh);
1391 if (ret)
1392 goto out;
1393
1394 memcpy(bh->b_data, buf, csize);
1395 set_buffer_uptodate(bh);
1396 ext4_handle_dirty_metadata(handle, ea_inode, bh);
1397
1398 buf += csize;
1399 wsize += csize;
1400 block += 1;
1401 }
1402
1403 inode_lock(ea_inode);
1404 i_size_write(ea_inode, wsize);
1405 ext4_update_i_disksize(ea_inode, wsize);
1406 inode_unlock(ea_inode);
1407
1408 ext4_mark_inode_dirty(handle, ea_inode);
1409
1410out:
1411 brelse(bh);
1412
1413 return ret;
1414}
1415
1416/*
1417 * Create an inode to store the value of a large EA.
1418 */
1419static struct inode *ext4_xattr_inode_create(handle_t *handle,
1420 struct inode *inode, u32 hash)
1421{
1422 struct inode *ea_inode = NULL;
1423 uid_t owner[2] = { i_uid_read(inode), i_gid_read(inode) };
1424 int err;
1425
1426 /*
1427 * Let the next inode be the goal, so we try and allocate the EA inode
1428 * in the same group, or nearby one.
1429 */
1430 ea_inode = ext4_new_inode(handle, inode->i_sb->s_root->d_inode,
1431 S_IFREG | 0600, NULL, inode->i_ino + 1, owner,
1432 EXT4_EA_INODE_FL);
1433 if (!IS_ERR(ea_inode)) {
1434 ea_inode->i_op = &ext4_file_inode_operations;
1435 ea_inode->i_fop = &ext4_file_operations;
1436 ext4_set_aops(ea_inode);
1437 ext4_xattr_inode_set_class(ea_inode);
1438 unlock_new_inode(ea_inode);
1439 ext4_xattr_inode_set_ref(ea_inode, 1);
1440 ext4_xattr_inode_set_hash(ea_inode, hash);
1441 err = ext4_mark_inode_dirty(handle, ea_inode);
1442 if (!err)
1443 err = ext4_inode_attach_jinode(ea_inode);
1444 if (err) {
1445 iput(ea_inode);
1446 return ERR_PTR(err);
1447 }
1448
1449 /*
1450 * Xattr inodes are shared therefore quota charging is performed
1451 * at a higher level.
1452 */
1453 dquot_free_inode(ea_inode);
1454 dquot_drop(ea_inode);
1455 inode_lock(ea_inode);
1456 ea_inode->i_flags |= S_NOQUOTA;
1457 inode_unlock(ea_inode);
1458 }
1459
1460 return ea_inode;
1461}
1462
1463static struct inode *
1464ext4_xattr_inode_cache_find(struct inode *inode, const void *value,
1465 size_t value_len, u32 hash)
1466{
1467 struct inode *ea_inode;
1468 struct mb_cache_entry *ce;
1469 struct mb_cache *ea_inode_cache = EA_INODE_CACHE(inode);
1470 void *ea_data;
1471
1472 if (!ea_inode_cache)
1473 return NULL;
1474
1475 ce = mb_cache_entry_find_first(ea_inode_cache, hash);
1476 if (!ce)
1477 return NULL;
1478
1479 ea_data = ext4_kvmalloc(value_len, GFP_NOFS);
1480 if (!ea_data) {
1481 mb_cache_entry_put(ea_inode_cache, ce);
1482 return NULL;
1483 }
1484
1485 while (ce) {
1486 ea_inode = ext4_iget(inode->i_sb, ce->e_value,
1487 EXT4_IGET_NORMAL);
1488 if (!IS_ERR(ea_inode) &&
1489 !is_bad_inode(ea_inode) &&
1490 (EXT4_I(ea_inode)->i_flags & EXT4_EA_INODE_FL) &&
1491 i_size_read(ea_inode) == value_len &&
1492 !ext4_xattr_inode_read(ea_inode, ea_data, value_len) &&
1493 !ext4_xattr_inode_verify_hashes(ea_inode, NULL, ea_data,
1494 value_len) &&
1495 !memcmp(value, ea_data, value_len)) {
1496 mb_cache_entry_touch(ea_inode_cache, ce);
1497 mb_cache_entry_put(ea_inode_cache, ce);
1498 kvfree(ea_data);
1499 return ea_inode;
1500 }
1501
1502 if (!IS_ERR(ea_inode))
1503 iput(ea_inode);
1504 ce = mb_cache_entry_find_next(ea_inode_cache, ce);
1505 }
1506 kvfree(ea_data);
1507 return NULL;
1508}
1509
1510/*
1511 * Add value of the EA in an inode.
1512 */
1513static int ext4_xattr_inode_lookup_create(handle_t *handle, struct inode *inode,
1514 const void *value, size_t value_len,
1515 struct inode **ret_inode)
1516{
1517 struct inode *ea_inode;
1518 u32 hash;
1519 int err;
1520
1521 hash = ext4_xattr_inode_hash(EXT4_SB(inode->i_sb), value, value_len);
1522 ea_inode = ext4_xattr_inode_cache_find(inode, value, value_len, hash);
1523 if (ea_inode) {
1524 err = ext4_xattr_inode_inc_ref(handle, ea_inode);
1525 if (err) {
1526 iput(ea_inode);
1527 return err;
1528 }
1529
1530 *ret_inode = ea_inode;
1531 return 0;
1532 }
1533
1534 /* Create an inode for the EA value */
1535 ea_inode = ext4_xattr_inode_create(handle, inode, hash);
1536 if (IS_ERR(ea_inode))
1537 return PTR_ERR(ea_inode);
1538
1539 err = ext4_xattr_inode_write(handle, ea_inode, value, value_len);
1540 if (err) {
1541 ext4_xattr_inode_dec_ref(handle, ea_inode);
1542 iput(ea_inode);
1543 return err;
1544 }
1545
1546 if (EA_INODE_CACHE(inode))
1547 mb_cache_entry_create(EA_INODE_CACHE(inode), GFP_NOFS, hash,
1548 ea_inode->i_ino, true /* reusable */);
1549
1550 *ret_inode = ea_inode;
1551 return 0;
1552}
1553
1554/*
1555 * Reserve min(block_size/8, 1024) bytes for xattr entries/names if ea_inode
1556 * feature is enabled.
1557 */
1558#define EXT4_XATTR_BLOCK_RESERVE(inode) min(i_blocksize(inode)/8, 1024U)
1559
1560static int ext4_xattr_set_entry(struct ext4_xattr_info *i,
1561 struct ext4_xattr_search *s,
1562 handle_t *handle, struct inode *inode,
1563 bool is_block)
1564{
1565 struct ext4_xattr_entry *last, *next;
1566 struct ext4_xattr_entry *here = s->here;
1567 size_t min_offs = s->end - s->base, name_len = strlen(i->name);
1568 int in_inode = i->in_inode;
1569 struct inode *old_ea_inode = NULL;
1570 struct inode *new_ea_inode = NULL;
1571 size_t old_size, new_size;
1572 int ret;
1573
1574 /* Space used by old and new values. */
1575 old_size = (!s->not_found && !here->e_value_inum) ?
1576 EXT4_XATTR_SIZE(le32_to_cpu(here->e_value_size)) : 0;
1577 new_size = (i->value && !in_inode) ? EXT4_XATTR_SIZE(i->value_len) : 0;
1578
1579 /*
1580 * Optimization for the simple case when old and new values have the
1581 * same padded sizes. Not applicable if external inodes are involved.
1582 */
1583 if (new_size && new_size == old_size) {
1584 size_t offs = le16_to_cpu(here->e_value_offs);
1585 void *val = s->base + offs;
1586
1587 here->e_value_size = cpu_to_le32(i->value_len);
1588 if (i->value == EXT4_ZERO_XATTR_VALUE) {
1589 memset(val, 0, new_size);
1590 } else {
1591 memcpy(val, i->value, i->value_len);
1592 /* Clear padding bytes. */
1593 memset(val + i->value_len, 0, new_size - i->value_len);
1594 }
1595 goto update_hash;
1596 }
1597
1598 /* Compute min_offs and last. */
1599 last = s->first;
1600 for (; !IS_LAST_ENTRY(last); last = next) {
1601 next = EXT4_XATTR_NEXT(last);
1602 if ((void *)next >= s->end) {
1603 EXT4_ERROR_INODE(inode, "corrupted xattr entries");
1604 ret = -EFSCORRUPTED;
1605 goto out;
1606 }
1607 if (!last->e_value_inum && last->e_value_size) {
1608 size_t offs = le16_to_cpu(last->e_value_offs);
1609 if (offs < min_offs)
1610 min_offs = offs;
1611 }
1612 }
1613
1614 /* Check whether we have enough space. */
1615 if (i->value) {
1616 size_t free;
1617
1618 free = min_offs - ((void *)last - s->base) - sizeof(__u32);
1619 if (!s->not_found)
1620 free += EXT4_XATTR_LEN(name_len) + old_size;
1621
1622 if (free < EXT4_XATTR_LEN(name_len) + new_size) {
1623 ret = -ENOSPC;
1624 goto out;
1625 }
1626
1627 /*
1628 * If storing the value in an external inode is an option,
1629 * reserve space for xattr entries/names in the external
1630 * attribute block so that a long value does not occupy the
1631 * whole space and prevent futher entries being added.
1632 */
1633 if (ext4_has_feature_ea_inode(inode->i_sb) &&
1634 new_size && is_block &&
1635 (min_offs + old_size - new_size) <
1636 EXT4_XATTR_BLOCK_RESERVE(inode)) {
1637 ret = -ENOSPC;
1638 goto out;
1639 }
1640 }
1641
1642 /*
1643 * Getting access to old and new ea inodes is subject to failures.
1644 * Finish that work before doing any modifications to the xattr data.
1645 */
1646 if (!s->not_found && here->e_value_inum) {
1647 ret = ext4_xattr_inode_iget(inode,
1648 le32_to_cpu(here->e_value_inum),
1649 le32_to_cpu(here->e_hash),
1650 &old_ea_inode);
1651 if (ret) {
1652 old_ea_inode = NULL;
1653 goto out;
1654 }
1655 }
1656 if (i->value && in_inode) {
1657 WARN_ON_ONCE(!i->value_len);
1658
1659 ret = ext4_xattr_inode_alloc_quota(inode, i->value_len);
1660 if (ret)
1661 goto out;
1662
1663 ret = ext4_xattr_inode_lookup_create(handle, inode, i->value,
1664 i->value_len,
1665 &new_ea_inode);
1666 if (ret) {
1667 new_ea_inode = NULL;
1668 ext4_xattr_inode_free_quota(inode, NULL, i->value_len);
1669 goto out;
1670 }
1671 }
1672
1673 if (old_ea_inode) {
1674 /* We are ready to release ref count on the old_ea_inode. */
1675 ret = ext4_xattr_inode_dec_ref(handle, old_ea_inode);
1676 if (ret) {
1677 /* Release newly required ref count on new_ea_inode. */
1678 if (new_ea_inode) {
1679 int err;
1680
1681 err = ext4_xattr_inode_dec_ref(handle,
1682 new_ea_inode);
1683 if (err)
1684 ext4_warning_inode(new_ea_inode,
1685 "dec ref new_ea_inode err=%d",
1686 err);
1687 ext4_xattr_inode_free_quota(inode, new_ea_inode,
1688 i->value_len);
1689 }
1690 goto out;
1691 }
1692
1693 ext4_xattr_inode_free_quota(inode, old_ea_inode,
1694 le32_to_cpu(here->e_value_size));
1695 }
1696
1697 /* No failures allowed past this point. */
1698
1699 if (!s->not_found && here->e_value_size && !here->e_value_inum) {
1700 /* Remove the old value. */
1701 void *first_val = s->base + min_offs;
1702 size_t offs = le16_to_cpu(here->e_value_offs);
1703 void *val = s->base + offs;
1704
1705 memmove(first_val + old_size, first_val, val - first_val);
1706 memset(first_val, 0, old_size);
1707 min_offs += old_size;
1708
1709 /* Adjust all value offsets. */
1710 last = s->first;
1711 while (!IS_LAST_ENTRY(last)) {
1712 size_t o = le16_to_cpu(last->e_value_offs);
1713
1714 if (!last->e_value_inum &&
1715 last->e_value_size && o < offs)
1716 last->e_value_offs = cpu_to_le16(o + old_size);
1717 last = EXT4_XATTR_NEXT(last);
1718 }
1719 }
1720
1721 if (!i->value) {
1722 /* Remove old name. */
1723 size_t size = EXT4_XATTR_LEN(name_len);
1724
1725 last = ENTRY((void *)last - size);
1726 memmove(here, (void *)here + size,
1727 (void *)last - (void *)here + sizeof(__u32));
1728 memset(last, 0, size);
1729 } else if (s->not_found) {
1730 /* Insert new name. */
1731 size_t size = EXT4_XATTR_LEN(name_len);
1732 size_t rest = (void *)last - (void *)here + sizeof(__u32);
1733
1734 memmove((void *)here + size, here, rest);
1735 memset(here, 0, size);
1736 here->e_name_index = i->name_index;
1737 here->e_name_len = name_len;
1738 memcpy(here->e_name, i->name, name_len);
1739 } else {
1740 /* This is an update, reset value info. */
1741 here->e_value_inum = 0;
1742 here->e_value_offs = 0;
1743 here->e_value_size = 0;
1744 }
1745
1746 if (i->value) {
1747 /* Insert new value. */
1748 if (in_inode) {
1749 here->e_value_inum = cpu_to_le32(new_ea_inode->i_ino);
1750 } else if (i->value_len) {
1751 void *val = s->base + min_offs - new_size;
1752
1753 here->e_value_offs = cpu_to_le16(min_offs - new_size);
1754 if (i->value == EXT4_ZERO_XATTR_VALUE) {
1755 memset(val, 0, new_size);
1756 } else {
1757 memcpy(val, i->value, i->value_len);
1758 /* Clear padding bytes. */
1759 memset(val + i->value_len, 0,
1760 new_size - i->value_len);
1761 }
1762 }
1763 here->e_value_size = cpu_to_le32(i->value_len);
1764 }
1765
1766update_hash:
1767 if (i->value) {
1768 __le32 hash = 0;
1769
1770 /* Entry hash calculation. */
1771 if (in_inode) {
1772 __le32 crc32c_hash;
1773
1774 /*
1775 * Feed crc32c hash instead of the raw value for entry
1776 * hash calculation. This is to avoid walking
1777 * potentially long value buffer again.
1778 */
1779 crc32c_hash = cpu_to_le32(
1780 ext4_xattr_inode_get_hash(new_ea_inode));
1781 hash = ext4_xattr_hash_entry(here->e_name,
1782 here->e_name_len,
1783 &crc32c_hash, 1);
1784 } else if (is_block) {
1785 __le32 *value = s->base + le16_to_cpu(
1786 here->e_value_offs);
1787
1788 hash = ext4_xattr_hash_entry(here->e_name,
1789 here->e_name_len, value,
1790 new_size >> 2);
1791 }
1792 here->e_hash = hash;
1793 }
1794
1795 if (is_block)
1796 ext4_xattr_rehash((struct ext4_xattr_header *)s->base);
1797
1798 ret = 0;
1799out:
1800 iput(old_ea_inode);
1801 iput(new_ea_inode);
1802 return ret;
1803}
1804
1805struct ext4_xattr_block_find {
1806 struct ext4_xattr_search s;
1807 struct buffer_head *bh;
1808};
1809
1810static int
1811ext4_xattr_block_find(struct inode *inode, struct ext4_xattr_info *i,
1812 struct ext4_xattr_block_find *bs)
1813{
1814 struct super_block *sb = inode->i_sb;
1815 int error;
1816
1817 ea_idebug(inode, "name=%d.%s, value=%p, value_len=%ld",
1818 i->name_index, i->name, i->value, (long)i->value_len);
1819
1820 if (EXT4_I(inode)->i_file_acl) {
1821 /* The inode already has an extended attribute block. */
1822 bs->bh = ext4_sb_bread(sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
1823 if (IS_ERR(bs->bh))
1824 return PTR_ERR(bs->bh);
1825 ea_bdebug(bs->bh, "b_count=%d, refcount=%d",
1826 atomic_read(&(bs->bh->b_count)),
1827 le32_to_cpu(BHDR(bs->bh)->h_refcount));
1828 error = ext4_xattr_check_block(inode, bs->bh);
1829 if (error)
1830 return error;
1831 /* Find the named attribute. */
1832 bs->s.base = BHDR(bs->bh);
1833 bs->s.first = BFIRST(bs->bh);
1834 bs->s.end = bs->bh->b_data + bs->bh->b_size;
1835 bs->s.here = bs->s.first;
1836 error = xattr_find_entry(inode, &bs->s.here, bs->s.end,
1837 i->name_index, i->name, 1);
1838 if (error && error != -ENODATA)
1839 return error;
1840 bs->s.not_found = error;
1841 }
1842 return 0;
1843}
1844
1845static int
1846ext4_xattr_block_set(handle_t *handle, struct inode *inode,
1847 struct ext4_xattr_info *i,
1848 struct ext4_xattr_block_find *bs)
1849{
1850 struct super_block *sb = inode->i_sb;
1851 struct buffer_head *new_bh = NULL;
1852 struct ext4_xattr_search s_copy = bs->s;
1853 struct ext4_xattr_search *s = &s_copy;
1854 struct mb_cache_entry *ce = NULL;
1855 int error = 0;
1856 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
1857 struct inode *ea_inode = NULL, *tmp_inode;
1858 size_t old_ea_inode_quota = 0;
1859 unsigned int ea_ino;
1860
1861
1862#define header(x) ((struct ext4_xattr_header *)(x))
1863
1864 if (s->base) {
1865 BUFFER_TRACE(bs->bh, "get_write_access");
1866 error = ext4_journal_get_write_access(handle, bs->bh);
1867 if (error)
1868 goto cleanup;
1869 lock_buffer(bs->bh);
1870
1871 if (header(s->base)->h_refcount == cpu_to_le32(1)) {
1872 __u32 hash = le32_to_cpu(BHDR(bs->bh)->h_hash);
1873
1874 /*
1875 * This must happen under buffer lock for
1876 * ext4_xattr_block_set() to reliably detect modified
1877 * block
1878 */
1879 if (ea_block_cache)
1880 mb_cache_entry_delete(ea_block_cache, hash,
1881 bs->bh->b_blocknr);
1882 ea_bdebug(bs->bh, "modifying in-place");
1883 error = ext4_xattr_set_entry(i, s, handle, inode,
1884 true /* is_block */);
1885 ext4_xattr_block_csum_set(inode, bs->bh);
1886 unlock_buffer(bs->bh);
1887 if (error == -EFSCORRUPTED)
1888 goto bad_block;
1889 if (!error)
1890 error = ext4_handle_dirty_metadata(handle,
1891 inode,
1892 bs->bh);
1893 if (error)
1894 goto cleanup;
1895 goto inserted;
1896 } else {
1897 int offset = (char *)s->here - bs->bh->b_data;
1898
1899 unlock_buffer(bs->bh);
1900 ea_bdebug(bs->bh, "cloning");
1901 s->base = kmalloc(bs->bh->b_size, GFP_NOFS);
1902 error = -ENOMEM;
1903 if (s->base == NULL)
1904 goto cleanup;
1905 memcpy(s->base, BHDR(bs->bh), bs->bh->b_size);
1906 s->first = ENTRY(header(s->base)+1);
1907 header(s->base)->h_refcount = cpu_to_le32(1);
1908 s->here = ENTRY(s->base + offset);
1909 s->end = s->base + bs->bh->b_size;
1910
1911 /*
1912 * If existing entry points to an xattr inode, we need
1913 * to prevent ext4_xattr_set_entry() from decrementing
1914 * ref count on it because the reference belongs to the
1915 * original block. In this case, make the entry look
1916 * like it has an empty value.
1917 */
1918 if (!s->not_found && s->here->e_value_inum) {
1919 ea_ino = le32_to_cpu(s->here->e_value_inum);
1920 error = ext4_xattr_inode_iget(inode, ea_ino,
1921 le32_to_cpu(s->here->e_hash),
1922 &tmp_inode);
1923 if (error)
1924 goto cleanup;
1925
1926 if (!ext4_test_inode_state(tmp_inode,
1927 EXT4_STATE_LUSTRE_EA_INODE)) {
1928 /*
1929 * Defer quota free call for previous
1930 * inode until success is guaranteed.
1931 */
1932 old_ea_inode_quota = le32_to_cpu(
1933 s->here->e_value_size);
1934 }
1935 iput(tmp_inode);
1936
1937 s->here->e_value_inum = 0;
1938 s->here->e_value_size = 0;
1939 }
1940 }
1941 } else {
1942 /* Allocate a buffer where we construct the new block. */
1943 s->base = kzalloc(sb->s_blocksize, GFP_NOFS);
1944 /* assert(header == s->base) */
1945 error = -ENOMEM;
1946 if (s->base == NULL)
1947 goto cleanup;
1948 header(s->base)->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
1949 header(s->base)->h_blocks = cpu_to_le32(1);
1950 header(s->base)->h_refcount = cpu_to_le32(1);
1951 s->first = ENTRY(header(s->base)+1);
1952 s->here = ENTRY(header(s->base)+1);
1953 s->end = s->base + sb->s_blocksize;
1954 }
1955
1956 error = ext4_xattr_set_entry(i, s, handle, inode, true /* is_block */);
1957 if (error == -EFSCORRUPTED)
1958 goto bad_block;
1959 if (error)
1960 goto cleanup;
1961
1962 if (i->value && s->here->e_value_inum) {
1963 /*
1964 * A ref count on ea_inode has been taken as part of the call to
1965 * ext4_xattr_set_entry() above. We would like to drop this
1966 * extra ref but we have to wait until the xattr block is
1967 * initialized and has its own ref count on the ea_inode.
1968 */
1969 ea_ino = le32_to_cpu(s->here->e_value_inum);
1970 error = ext4_xattr_inode_iget(inode, ea_ino,
1971 le32_to_cpu(s->here->e_hash),
1972 &ea_inode);
1973 if (error) {
1974 ea_inode = NULL;
1975 goto cleanup;
1976 }
1977 }
1978
1979inserted:
1980 if (!IS_LAST_ENTRY(s->first)) {
1981 new_bh = ext4_xattr_block_cache_find(inode, header(s->base),
1982 &ce);
1983 if (new_bh) {
1984 /* We found an identical block in the cache. */
1985 if (new_bh == bs->bh)
1986 ea_bdebug(new_bh, "keeping");
1987 else {
1988 u32 ref;
1989
1990 WARN_ON_ONCE(dquot_initialize_needed(inode));
1991
1992 /* The old block is released after updating
1993 the inode. */
1994 error = dquot_alloc_block(inode,
1995 EXT4_C2B(EXT4_SB(sb), 1));
1996 if (error)
1997 goto cleanup;
1998 BUFFER_TRACE(new_bh, "get_write_access");
1999 error = ext4_journal_get_write_access(handle,
2000 new_bh);
2001 if (error)
2002 goto cleanup_dquot;
2003 lock_buffer(new_bh);
2004 /*
2005 * We have to be careful about races with
2006 * freeing, rehashing or adding references to
2007 * xattr block. Once we hold buffer lock xattr
2008 * block's state is stable so we can check
2009 * whether the block got freed / rehashed or
2010 * not. Since we unhash mbcache entry under
2011 * buffer lock when freeing / rehashing xattr
2012 * block, checking whether entry is still
2013 * hashed is reliable. Same rules hold for
2014 * e_reusable handling.
2015 */
2016 if (hlist_bl_unhashed(&ce->e_hash_list) ||
2017 !ce->e_reusable) {
2018 /*
2019 * Undo everything and check mbcache
2020 * again.
2021 */
2022 unlock_buffer(new_bh);
2023 dquot_free_block(inode,
2024 EXT4_C2B(EXT4_SB(sb),
2025 1));
2026 brelse(new_bh);
2027 mb_cache_entry_put(ea_block_cache, ce);
2028 ce = NULL;
2029 new_bh = NULL;
2030 goto inserted;
2031 }
2032 ref = le32_to_cpu(BHDR(new_bh)->h_refcount) + 1;
2033 BHDR(new_bh)->h_refcount = cpu_to_le32(ref);
2034 if (ref >= EXT4_XATTR_REFCOUNT_MAX)
2035 ce->e_reusable = 0;
2036 ea_bdebug(new_bh, "reusing; refcount now=%d",
2037 ref);
2038 ext4_xattr_block_csum_set(inode, new_bh);
2039 unlock_buffer(new_bh);
2040 error = ext4_handle_dirty_metadata(handle,
2041 inode,
2042 new_bh);
2043 if (error)
2044 goto cleanup_dquot;
2045 }
2046 mb_cache_entry_touch(ea_block_cache, ce);
2047 mb_cache_entry_put(ea_block_cache, ce);
2048 ce = NULL;
2049 } else if (bs->bh && s->base == bs->bh->b_data) {
2050 /* We were modifying this block in-place. */
2051 ea_bdebug(bs->bh, "keeping this block");
2052 ext4_xattr_block_cache_insert(ea_block_cache, bs->bh);
2053 new_bh = bs->bh;
2054 get_bh(new_bh);
2055 } else {
2056 /* We need to allocate a new block */
2057 ext4_fsblk_t goal, block;
2058
2059 WARN_ON_ONCE(dquot_initialize_needed(inode));
2060
2061 goal = ext4_group_first_block_no(sb,
2062 EXT4_I(inode)->i_block_group);
2063
2064 /* non-extent files can't have physical blocks past 2^32 */
2065 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
2066 goal = goal & EXT4_MAX_BLOCK_FILE_PHYS;
2067
2068 block = ext4_new_meta_blocks(handle, inode, goal, 0,
2069 NULL, &error);
2070 if (error)
2071 goto cleanup;
2072
2073 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
2074 BUG_ON(block > EXT4_MAX_BLOCK_FILE_PHYS);
2075
2076 ea_idebug(inode, "creating block %llu",
2077 (unsigned long long)block);
2078
2079 new_bh = sb_getblk(sb, block);
2080 if (unlikely(!new_bh)) {
2081 error = -ENOMEM;
2082getblk_failed:
2083 ext4_free_blocks(handle, inode, NULL, block, 1,
2084 EXT4_FREE_BLOCKS_METADATA);
2085 goto cleanup;
2086 }
2087 error = ext4_xattr_inode_inc_ref_all(handle, inode,
2088 ENTRY(header(s->base)+1));
2089 if (error)
2090 goto getblk_failed;
2091 if (ea_inode) {
2092 /* Drop the extra ref on ea_inode. */
2093 error = ext4_xattr_inode_dec_ref(handle,
2094 ea_inode);
2095 if (error)
2096 ext4_warning_inode(ea_inode,
2097 "dec ref error=%d",
2098 error);
2099 iput(ea_inode);
2100 ea_inode = NULL;
2101 }
2102
2103 lock_buffer(new_bh);
2104 error = ext4_journal_get_create_access(handle, new_bh);
2105 if (error) {
2106 unlock_buffer(new_bh);
2107 error = -EIO;
2108 goto getblk_failed;
2109 }
2110 memcpy(new_bh->b_data, s->base, new_bh->b_size);
2111 ext4_xattr_block_csum_set(inode, new_bh);
2112 set_buffer_uptodate(new_bh);
2113 unlock_buffer(new_bh);
2114 ext4_xattr_block_cache_insert(ea_block_cache, new_bh);
2115 error = ext4_handle_dirty_metadata(handle, inode,
2116 new_bh);
2117 if (error)
2118 goto cleanup;
2119 }
2120 }
2121
2122 if (old_ea_inode_quota)
2123 ext4_xattr_inode_free_quota(inode, NULL, old_ea_inode_quota);
2124
2125 /* Update the inode. */
2126 EXT4_I(inode)->i_file_acl = new_bh ? new_bh->b_blocknr : 0;
2127
2128 /* Drop the previous xattr block. */
2129 if (bs->bh && bs->bh != new_bh) {
2130 struct ext4_xattr_inode_array *ea_inode_array = NULL;
2131
2132 ext4_xattr_release_block(handle, inode, bs->bh,
2133 &ea_inode_array,
2134 0 /* extra_credits */);
2135 ext4_xattr_inode_array_free(ea_inode_array);
2136 }
2137 error = 0;
2138
2139cleanup:
2140 if (ea_inode) {
2141 int error2;
2142
2143 error2 = ext4_xattr_inode_dec_ref(handle, ea_inode);
2144 if (error2)
2145 ext4_warning_inode(ea_inode, "dec ref error=%d",
2146 error2);
2147
2148 /* If there was an error, revert the quota charge. */
2149 if (error)
2150 ext4_xattr_inode_free_quota(inode, ea_inode,
2151 i_size_read(ea_inode));
2152 iput(ea_inode);
2153 }
2154 if (ce)
2155 mb_cache_entry_put(ea_block_cache, ce);
2156 brelse(new_bh);
2157 if (!(bs->bh && s->base == bs->bh->b_data))
2158 kfree(s->base);
2159
2160 return error;
2161
2162cleanup_dquot:
2163 dquot_free_block(inode, EXT4_C2B(EXT4_SB(sb), 1));
2164 goto cleanup;
2165
2166bad_block:
2167 EXT4_ERROR_INODE(inode, "bad block %llu",
2168 EXT4_I(inode)->i_file_acl);
2169 goto cleanup;
2170
2171#undef header
2172}
2173
2174int ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i,
2175 struct ext4_xattr_ibody_find *is)
2176{
2177 struct ext4_xattr_ibody_header *header;
2178 struct ext4_inode *raw_inode;
2179 int error;
2180
2181 if (EXT4_I(inode)->i_extra_isize == 0)
2182 return 0;
2183 raw_inode = ext4_raw_inode(&is->iloc);
2184 header = IHDR(inode, raw_inode);
2185 is->s.base = is->s.first = IFIRST(header);
2186 is->s.here = is->s.first;
2187 is->s.end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
2188 if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
2189 error = xattr_check_inode(inode, header, is->s.end);
2190 if (error)
2191 return error;
2192 /* Find the named attribute. */
2193 error = xattr_find_entry(inode, &is->s.here, is->s.end,
2194 i->name_index, i->name, 0);
2195 if (error && error != -ENODATA)
2196 return error;
2197 is->s.not_found = error;
2198 }
2199 return 0;
2200}
2201
2202int ext4_xattr_ibody_inline_set(handle_t *handle, struct inode *inode,
2203 struct ext4_xattr_info *i,
2204 struct ext4_xattr_ibody_find *is)
2205{
2206 struct ext4_xattr_ibody_header *header;
2207 struct ext4_xattr_search *s = &is->s;
2208 int error;
2209
2210 if (EXT4_I(inode)->i_extra_isize == 0)
2211 return -ENOSPC;
2212 error = ext4_xattr_set_entry(i, s, handle, inode, false /* is_block */);
2213 if (error)
2214 return error;
2215 header = IHDR(inode, ext4_raw_inode(&is->iloc));
2216 if (!IS_LAST_ENTRY(s->first)) {
2217 header->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
2218 ext4_set_inode_state(inode, EXT4_STATE_XATTR);
2219 } else {
2220 header->h_magic = cpu_to_le32(0);
2221 ext4_clear_inode_state(inode, EXT4_STATE_XATTR);
2222 }
2223 return 0;
2224}
2225
2226static int 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_I(inode)->i_extra_isize == 0)
2235 return -ENOSPC;
2236 error = ext4_xattr_set_entry(i, s, handle, inode, false /* is_block */);
2237 if (error)
2238 return error;
2239 header = IHDR(inode, ext4_raw_inode(&is->iloc));
2240 if (!IS_LAST_ENTRY(s->first)) {
2241 header->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
2242 ext4_set_inode_state(inode, EXT4_STATE_XATTR);
2243 } else {
2244 header->h_magic = cpu_to_le32(0);
2245 ext4_clear_inode_state(inode, EXT4_STATE_XATTR);
2246 }
2247 return 0;
2248}
2249
2250static int ext4_xattr_value_same(struct ext4_xattr_search *s,
2251 struct ext4_xattr_info *i)
2252{
2253 void *value;
2254
2255 /* When e_value_inum is set the value is stored externally. */
2256 if (s->here->e_value_inum)
2257 return 0;
2258 if (le32_to_cpu(s->here->e_value_size) != i->value_len)
2259 return 0;
2260 value = ((void *)s->base) + le16_to_cpu(s->here->e_value_offs);
2261 return !memcmp(value, i->value, i->value_len);
2262}
2263
2264static struct buffer_head *ext4_xattr_get_block(struct inode *inode)
2265{
2266 struct buffer_head *bh;
2267 int error;
2268
2269 if (!EXT4_I(inode)->i_file_acl)
2270 return NULL;
2271 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
2272 if (IS_ERR(bh))
2273 return bh;
2274 error = ext4_xattr_check_block(inode, bh);
2275 if (error) {
2276 brelse(bh);
2277 return ERR_PTR(error);
2278 }
2279 return bh;
2280}
2281
2282/*
2283 * ext4_xattr_set_handle()
2284 *
2285 * Create, replace or remove an extended attribute for this inode. Value
2286 * is NULL to remove an existing extended attribute, and non-NULL to
2287 * either replace an existing extended attribute, or create a new extended
2288 * attribute. The flags XATTR_REPLACE and XATTR_CREATE
2289 * specify that an extended attribute must exist and must not exist
2290 * previous to the call, respectively.
2291 *
2292 * Returns 0, or a negative error number on failure.
2293 */
2294int
2295ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
2296 const char *name, const void *value, size_t value_len,
2297 int flags)
2298{
2299 struct ext4_xattr_info i = {
2300 .name_index = name_index,
2301 .name = name,
2302 .value = value,
2303 .value_len = value_len,
2304 .in_inode = 0,
2305 };
2306 struct ext4_xattr_ibody_find is = {
2307 .s = { .not_found = -ENODATA, },
2308 };
2309 struct ext4_xattr_block_find bs = {
2310 .s = { .not_found = -ENODATA, },
2311 };
2312 int no_expand;
2313 int error;
2314
2315 if (!name)
2316 return -EINVAL;
2317 if (strlen(name) > 255)
2318 return -ERANGE;
2319
2320 ext4_write_lock_xattr(inode, &no_expand);
2321
2322 /* Check journal credits under write lock. */
2323 if (ext4_handle_valid(handle)) {
2324 struct buffer_head *bh;
2325 int credits;
2326
2327 bh = ext4_xattr_get_block(inode);
2328 if (IS_ERR(bh)) {
2329 error = PTR_ERR(bh);
2330 goto cleanup;
2331 }
2332
2333 credits = __ext4_xattr_set_credits(inode->i_sb, inode, bh,
2334 value_len,
2335 flags & XATTR_CREATE);
2336 brelse(bh);
2337
2338 if (!ext4_handle_has_enough_credits(handle, credits)) {
2339 error = -ENOSPC;
2340 goto cleanup;
2341 }
2342 }
2343
2344 error = ext4_reserve_inode_write(handle, inode, &is.iloc);
2345 if (error)
2346 goto cleanup;
2347
2348 if (ext4_test_inode_state(inode, EXT4_STATE_NEW)) {
2349 struct ext4_inode *raw_inode = ext4_raw_inode(&is.iloc);
2350 memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size);
2351 ext4_clear_inode_state(inode, EXT4_STATE_NEW);
2352 }
2353
2354 error = ext4_xattr_ibody_find(inode, &i, &is);
2355 if (error)
2356 goto cleanup;
2357 if (is.s.not_found)
2358 error = ext4_xattr_block_find(inode, &i, &bs);
2359 if (error)
2360 goto cleanup;
2361 if (is.s.not_found && bs.s.not_found) {
2362 error = -ENODATA;
2363 if (flags & XATTR_REPLACE)
2364 goto cleanup;
2365 error = 0;
2366 if (!value)
2367 goto cleanup;
2368 } else {
2369 error = -EEXIST;
2370 if (flags & XATTR_CREATE)
2371 goto cleanup;
2372 }
2373
2374 if (!value) {
2375 if (!is.s.not_found)
2376 error = ext4_xattr_ibody_set(handle, inode, &i, &is);
2377 else if (!bs.s.not_found)
2378 error = ext4_xattr_block_set(handle, inode, &i, &bs);
2379 } else {
2380 error = 0;
2381 /* Xattr value did not change? Save us some work and bail out */
2382 if (!is.s.not_found && ext4_xattr_value_same(&is.s, &i))
2383 goto cleanup;
2384 if (!bs.s.not_found && ext4_xattr_value_same(&bs.s, &i))
2385 goto cleanup;
2386
2387 if (ext4_has_feature_ea_inode(inode->i_sb) &&
2388 (EXT4_XATTR_SIZE(i.value_len) >
2389 EXT4_XATTR_MIN_LARGE_EA_SIZE(inode->i_sb->s_blocksize)))
2390 i.in_inode = 1;
2391retry_inode:
2392 error = ext4_xattr_ibody_set(handle, inode, &i, &is);
2393 if (!error && !bs.s.not_found) {
2394 i.value = NULL;
2395 error = ext4_xattr_block_set(handle, inode, &i, &bs);
2396 } else if (error == -ENOSPC) {
2397 if (EXT4_I(inode)->i_file_acl && !bs.s.base) {
2398 brelse(bs.bh);
2399 bs.bh = NULL;
2400 error = ext4_xattr_block_find(inode, &i, &bs);
2401 if (error)
2402 goto cleanup;
2403 }
2404 error = ext4_xattr_block_set(handle, inode, &i, &bs);
2405 if (!error && !is.s.not_found) {
2406 i.value = NULL;
2407 error = ext4_xattr_ibody_set(handle, inode, &i,
2408 &is);
2409 } else if (error == -ENOSPC) {
2410 /*
2411 * Xattr does not fit in the block, store at
2412 * external inode if possible.
2413 */
2414 if (ext4_has_feature_ea_inode(inode->i_sb) &&
2415 !i.in_inode) {
2416 i.in_inode = 1;
2417 goto retry_inode;
2418 }
2419 }
2420 }
2421 }
2422 if (!error) {
2423 ext4_xattr_update_super_block(handle, inode->i_sb);
2424 inode->i_ctime = current_time(inode);
2425 if (!value)
2426 no_expand = 0;
2427 error = ext4_mark_iloc_dirty(handle, inode, &is.iloc);
2428 /*
2429 * The bh is consumed by ext4_mark_iloc_dirty, even with
2430 * error != 0.
2431 */
2432 is.iloc.bh = NULL;
2433 if (IS_SYNC(inode))
2434 ext4_handle_sync(handle);
2435 }
2436
2437cleanup:
2438 brelse(is.iloc.bh);
2439 brelse(bs.bh);
2440 ext4_write_unlock_xattr(inode, &no_expand);
2441 return error;
2442}
2443
2444int ext4_xattr_set_credits(struct inode *inode, size_t value_len,
2445 bool is_create, int *credits)
2446{
2447 struct buffer_head *bh;
2448 int err;
2449
2450 *credits = 0;
2451
2452 if (!EXT4_SB(inode->i_sb)->s_journal)
2453 return 0;
2454
2455 down_read(&EXT4_I(inode)->xattr_sem);
2456
2457 bh = ext4_xattr_get_block(inode);
2458 if (IS_ERR(bh)) {
2459 err = PTR_ERR(bh);
2460 } else {
2461 *credits = __ext4_xattr_set_credits(inode->i_sb, inode, bh,
2462 value_len, is_create);
2463 brelse(bh);
2464 err = 0;
2465 }
2466
2467 up_read(&EXT4_I(inode)->xattr_sem);
2468 return err;
2469}
2470
2471/*
2472 * ext4_xattr_set()
2473 *
2474 * Like ext4_xattr_set_handle, but start from an inode. This extended
2475 * attribute modification is a filesystem transaction by itself.
2476 *
2477 * Returns 0, or a negative error number on failure.
2478 */
2479int
2480ext4_xattr_set(struct inode *inode, int name_index, const char *name,
2481 const void *value, size_t value_len, int flags)
2482{
2483 handle_t *handle;
2484 struct super_block *sb = inode->i_sb;
2485 int error, retries = 0;
2486 int credits;
2487
2488 error = dquot_initialize(inode);
2489 if (error)
2490 return error;
2491
2492retry:
2493 error = ext4_xattr_set_credits(inode, value_len, flags & XATTR_CREATE,
2494 &credits);
2495 if (error)
2496 return error;
2497
2498 handle = ext4_journal_start(inode, EXT4_HT_XATTR, credits);
2499 if (IS_ERR(handle)) {
2500 error = PTR_ERR(handle);
2501 } else {
2502 int error2;
2503
2504 error = ext4_xattr_set_handle(handle, inode, name_index, name,
2505 value, value_len, flags);
2506 error2 = ext4_journal_stop(handle);
2507 if (error == -ENOSPC &&
2508 ext4_should_retry_alloc(sb, &retries))
2509 goto retry;
2510 if (error == 0)
2511 error = error2;
2512 }
2513
2514 return error;
2515}
2516
2517/*
2518 * Shift the EA entries in the inode to create space for the increased
2519 * i_extra_isize.
2520 */
2521static void ext4_xattr_shift_entries(struct ext4_xattr_entry *entry,
2522 int value_offs_shift, void *to,
2523 void *from, size_t n)
2524{
2525 struct ext4_xattr_entry *last = entry;
2526 int new_offs;
2527
2528 /* We always shift xattr headers further thus offsets get lower */
2529 BUG_ON(value_offs_shift > 0);
2530
2531 /* Adjust the value offsets of the entries */
2532 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
2533 if (!last->e_value_inum && last->e_value_size) {
2534 new_offs = le16_to_cpu(last->e_value_offs) +
2535 value_offs_shift;
2536 last->e_value_offs = cpu_to_le16(new_offs);
2537 }
2538 }
2539 /* Shift the entries by n bytes */
2540 memmove(to, from, n);
2541}
2542
2543/*
2544 * Move xattr pointed to by 'entry' from inode into external xattr block
2545 */
2546static int ext4_xattr_move_to_block(handle_t *handle, struct inode *inode,
2547 struct ext4_inode *raw_inode,
2548 struct ext4_xattr_entry *entry)
2549{
2550 struct ext4_xattr_ibody_find *is = NULL;
2551 struct ext4_xattr_block_find *bs = NULL;
2552 char *buffer = NULL, *b_entry_name = NULL;
2553 size_t value_size = le32_to_cpu(entry->e_value_size);
2554 struct ext4_xattr_info i = {
2555 .value = NULL,
2556 .value_len = 0,
2557 .name_index = entry->e_name_index,
2558 .in_inode = !!entry->e_value_inum,
2559 };
2560 struct ext4_xattr_ibody_header *header = IHDR(inode, raw_inode);
2561 int error;
2562
2563 is = kzalloc(sizeof(struct ext4_xattr_ibody_find), GFP_NOFS);
2564 bs = kzalloc(sizeof(struct ext4_xattr_block_find), GFP_NOFS);
2565 buffer = kmalloc(value_size, GFP_NOFS);
2566 b_entry_name = kmalloc(entry->e_name_len + 1, GFP_NOFS);
2567 if (!is || !bs || !buffer || !b_entry_name) {
2568 error = -ENOMEM;
2569 goto out;
2570 }
2571
2572 is->s.not_found = -ENODATA;
2573 bs->s.not_found = -ENODATA;
2574 is->iloc.bh = NULL;
2575 bs->bh = NULL;
2576
2577 /* Save the entry name and the entry value */
2578 if (entry->e_value_inum) {
2579 error = ext4_xattr_inode_get(inode, entry, buffer, value_size);
2580 if (error)
2581 goto out;
2582 } else {
2583 size_t value_offs = le16_to_cpu(entry->e_value_offs);
2584 memcpy(buffer, (void *)IFIRST(header) + value_offs, value_size);
2585 }
2586
2587 memcpy(b_entry_name, entry->e_name, entry->e_name_len);
2588 b_entry_name[entry->e_name_len] = '\0';
2589 i.name = b_entry_name;
2590
2591 error = ext4_get_inode_loc(inode, &is->iloc);
2592 if (error)
2593 goto out;
2594
2595 error = ext4_xattr_ibody_find(inode, &i, is);
2596 if (error)
2597 goto out;
2598
2599 /* Remove the chosen entry from the inode */
2600 error = ext4_xattr_ibody_set(handle, inode, &i, is);
2601 if (error)
2602 goto out;
2603
2604 i.value = buffer;
2605 i.value_len = value_size;
2606 error = ext4_xattr_block_find(inode, &i, bs);
2607 if (error)
2608 goto out;
2609
2610 /* Add entry which was removed from the inode into the block */
2611 error = ext4_xattr_block_set(handle, inode, &i, bs);
2612 if (error)
2613 goto out;
2614 error = 0;
2615out:
2616 kfree(b_entry_name);
2617 kfree(buffer);
2618 if (is)
2619 brelse(is->iloc.bh);
2620 if (bs)
2621 brelse(bs->bh);
2622 kfree(is);
2623 kfree(bs);
2624
2625 return error;
2626}
2627
2628static int ext4_xattr_make_inode_space(handle_t *handle, struct inode *inode,
2629 struct ext4_inode *raw_inode,
2630 int isize_diff, size_t ifree,
2631 size_t bfree, int *total_ino)
2632{
2633 struct ext4_xattr_ibody_header *header = IHDR(inode, raw_inode);
2634 struct ext4_xattr_entry *small_entry;
2635 struct ext4_xattr_entry *entry;
2636 struct ext4_xattr_entry *last;
2637 unsigned int entry_size; /* EA entry size */
2638 unsigned int total_size; /* EA entry size + value size */
2639 unsigned int min_total_size;
2640 int error;
2641
2642 while (isize_diff > ifree) {
2643 entry = NULL;
2644 small_entry = NULL;
2645 min_total_size = ~0U;
2646 last = IFIRST(header);
2647 /* Find the entry best suited to be pushed into EA block */
2648 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
2649 /* never move system.data out of the inode */
2650 if ((last->e_name_len == 4) &&
2651 (last->e_name_index == EXT4_XATTR_INDEX_SYSTEM) &&
2652 !memcmp(last->e_name, "data", 4))
2653 continue;
2654 total_size = EXT4_XATTR_LEN(last->e_name_len);
2655 if (!last->e_value_inum)
2656 total_size += EXT4_XATTR_SIZE(
2657 le32_to_cpu(last->e_value_size));
2658 if (total_size <= bfree &&
2659 total_size < min_total_size) {
2660 if (total_size + ifree < isize_diff) {
2661 small_entry = last;
2662 } else {
2663 entry = last;
2664 min_total_size = total_size;
2665 }
2666 }
2667 }
2668
2669 if (entry == NULL) {
2670 if (small_entry == NULL)
2671 return -ENOSPC;
2672 entry = small_entry;
2673 }
2674
2675 entry_size = EXT4_XATTR_LEN(entry->e_name_len);
2676 total_size = entry_size;
2677 if (!entry->e_value_inum)
2678 total_size += EXT4_XATTR_SIZE(
2679 le32_to_cpu(entry->e_value_size));
2680 error = ext4_xattr_move_to_block(handle, inode, raw_inode,
2681 entry);
2682 if (error)
2683 return error;
2684
2685 *total_ino -= entry_size;
2686 ifree += total_size;
2687 bfree -= total_size;
2688 }
2689
2690 return 0;
2691}
2692
2693/*
2694 * Expand an inode by new_extra_isize bytes when EAs are present.
2695 * Returns 0 on success or negative error number on failure.
2696 */
2697int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
2698 struct ext4_inode *raw_inode, handle_t *handle)
2699{
2700 struct ext4_xattr_ibody_header *header;
2701 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2702 static unsigned int mnt_count;
2703 size_t min_offs;
2704 size_t ifree, bfree;
2705 int total_ino;
2706 void *base, *end;
2707 int error = 0, tried_min_extra_isize = 0;
2708 int s_min_extra_isize = le16_to_cpu(sbi->s_es->s_min_extra_isize);
2709 int isize_diff; /* How much do we need to grow i_extra_isize */
2710
2711retry:
2712 isize_diff = new_extra_isize - EXT4_I(inode)->i_extra_isize;
2713 if (EXT4_I(inode)->i_extra_isize >= new_extra_isize)
2714 return 0;
2715
2716 header = IHDR(inode, raw_inode);
2717
2718 /*
2719 * Check if enough free space is available in the inode to shift the
2720 * entries ahead by new_extra_isize.
2721 */
2722
2723 base = IFIRST(header);
2724 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
2725 min_offs = end - base;
2726 total_ino = sizeof(struct ext4_xattr_ibody_header) + sizeof(u32);
2727
2728 error = xattr_check_inode(inode, header, end);
2729 if (error)
2730 goto cleanup;
2731
2732 ifree = ext4_xattr_free_space(base, &min_offs, base, &total_ino);
2733 if (ifree >= isize_diff)
2734 goto shift;
2735
2736 /*
2737 * Enough free space isn't available in the inode, check if
2738 * EA block can hold new_extra_isize bytes.
2739 */
2740 if (EXT4_I(inode)->i_file_acl) {
2741 struct buffer_head *bh;
2742
2743 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
2744 if (IS_ERR(bh)) {
2745 error = PTR_ERR(bh);
2746 goto cleanup;
2747 }
2748 error = ext4_xattr_check_block(inode, bh);
2749 if (error) {
2750 brelse(bh);
2751 goto cleanup;
2752 }
2753 base = BHDR(bh);
2754 end = bh->b_data + bh->b_size;
2755 min_offs = end - base;
2756 bfree = ext4_xattr_free_space(BFIRST(bh), &min_offs, base,
2757 NULL);
2758 brelse(bh);
2759 if (bfree + ifree < isize_diff) {
2760 if (!tried_min_extra_isize && s_min_extra_isize) {
2761 tried_min_extra_isize++;
2762 new_extra_isize = s_min_extra_isize;
2763 goto retry;
2764 }
2765 error = -ENOSPC;
2766 goto cleanup;
2767 }
2768 } else {
2769 bfree = inode->i_sb->s_blocksize;
2770 }
2771
2772 error = ext4_xattr_make_inode_space(handle, inode, raw_inode,
2773 isize_diff, ifree, bfree,
2774 &total_ino);
2775 if (error) {
2776 if (error == -ENOSPC && !tried_min_extra_isize &&
2777 s_min_extra_isize) {
2778 tried_min_extra_isize++;
2779 new_extra_isize = s_min_extra_isize;
2780 goto retry;
2781 }
2782 goto cleanup;
2783 }
2784shift:
2785 /* Adjust the offsets and shift the remaining entries ahead */
2786 ext4_xattr_shift_entries(IFIRST(header), EXT4_I(inode)->i_extra_isize
2787 - new_extra_isize, (void *)raw_inode +
2788 EXT4_GOOD_OLD_INODE_SIZE + new_extra_isize,
2789 (void *)header, total_ino);
2790 EXT4_I(inode)->i_extra_isize = new_extra_isize;
2791
2792cleanup:
2793 if (error && (mnt_count != le16_to_cpu(sbi->s_es->s_mnt_count))) {
2794 ext4_warning(inode->i_sb, "Unable to expand inode %lu. Delete some EAs or run e2fsck.",
2795 inode->i_ino);
2796 mnt_count = le16_to_cpu(sbi->s_es->s_mnt_count);
2797 }
2798 return error;
2799}
2800
2801#define EIA_INCR 16 /* must be 2^n */
2802#define EIA_MASK (EIA_INCR - 1)
2803
2804/* Add the large xattr @inode into @ea_inode_array for deferred iput().
2805 * If @ea_inode_array is new or full it will be grown and the old
2806 * contents copied over.
2807 */
2808static int
2809ext4_expand_inode_array(struct ext4_xattr_inode_array **ea_inode_array,
2810 struct inode *inode)
2811{
2812 if (*ea_inode_array == NULL) {
2813 /*
2814 * Start with 15 inodes, so it fits into a power-of-two size.
2815 * If *ea_inode_array is NULL, this is essentially offsetof()
2816 */
2817 (*ea_inode_array) =
2818 kmalloc(offsetof(struct ext4_xattr_inode_array,
2819 inodes[EIA_MASK]),
2820 GFP_NOFS);
2821 if (*ea_inode_array == NULL)
2822 return -ENOMEM;
2823 (*ea_inode_array)->count = 0;
2824 } else if (((*ea_inode_array)->count & EIA_MASK) == EIA_MASK) {
2825 /* expand the array once all 15 + n * 16 slots are full */
2826 struct ext4_xattr_inode_array *new_array = NULL;
2827 int count = (*ea_inode_array)->count;
2828
2829 /* if new_array is NULL, this is essentially offsetof() */
2830 new_array = kmalloc(
2831 offsetof(struct ext4_xattr_inode_array,
2832 inodes[count + EIA_INCR]),
2833 GFP_NOFS);
2834 if (new_array == NULL)
2835 return -ENOMEM;
2836 memcpy(new_array, *ea_inode_array,
2837 offsetof(struct ext4_xattr_inode_array, inodes[count]));
2838 kfree(*ea_inode_array);
2839 *ea_inode_array = new_array;
2840 }
2841 (*ea_inode_array)->inodes[(*ea_inode_array)->count++] = inode;
2842 return 0;
2843}
2844
2845/*
2846 * ext4_xattr_delete_inode()
2847 *
2848 * Free extended attribute resources associated with this inode. Traverse
2849 * all entries and decrement reference on any xattr inodes associated with this
2850 * inode. This is called immediately before an inode is freed. We have exclusive
2851 * access to the inode. If an orphan inode is deleted it will also release its
2852 * references on xattr block and xattr inodes.
2853 */
2854int ext4_xattr_delete_inode(handle_t *handle, struct inode *inode,
2855 struct ext4_xattr_inode_array **ea_inode_array,
2856 int extra_credits)
2857{
2858 struct buffer_head *bh = NULL;
2859 struct ext4_xattr_ibody_header *header;
2860 struct ext4_iloc iloc = { .bh = NULL };
2861 struct ext4_xattr_entry *entry;
2862 struct inode *ea_inode;
2863 int error;
2864
2865 error = ext4_xattr_ensure_credits(handle, inode, extra_credits,
2866 NULL /* bh */,
2867 false /* dirty */,
2868 false /* block_csum */);
2869 if (error) {
2870 EXT4_ERROR_INODE(inode, "ensure credits (error %d)", error);
2871 goto cleanup;
2872 }
2873
2874 if (ext4_has_feature_ea_inode(inode->i_sb) &&
2875 ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
2876
2877 error = ext4_get_inode_loc(inode, &iloc);
2878 if (error) {
2879 EXT4_ERROR_INODE(inode, "inode loc (error %d)", error);
2880 goto cleanup;
2881 }
2882
2883 error = ext4_journal_get_write_access(handle, iloc.bh);
2884 if (error) {
2885 EXT4_ERROR_INODE(inode, "write access (error %d)",
2886 error);
2887 goto cleanup;
2888 }
2889
2890 header = IHDR(inode, ext4_raw_inode(&iloc));
2891 if (header->h_magic == cpu_to_le32(EXT4_XATTR_MAGIC))
2892 ext4_xattr_inode_dec_ref_all(handle, inode, iloc.bh,
2893 IFIRST(header),
2894 false /* block_csum */,
2895 ea_inode_array,
2896 extra_credits,
2897 false /* skip_quota */);
2898 }
2899
2900 if (EXT4_I(inode)->i_file_acl) {
2901 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
2902 if (IS_ERR(bh)) {
2903 error = PTR_ERR(bh);
2904 if (error == -EIO)
2905 EXT4_ERROR_INODE(inode, "block %llu read error",
2906 EXT4_I(inode)->i_file_acl);
2907 bh = NULL;
2908 goto cleanup;
2909 }
2910 error = ext4_xattr_check_block(inode, bh);
2911 if (error)
2912 goto cleanup;
2913
2914 if (ext4_has_feature_ea_inode(inode->i_sb)) {
2915 for (entry = BFIRST(bh); !IS_LAST_ENTRY(entry);
2916 entry = EXT4_XATTR_NEXT(entry)) {
2917 if (!entry->e_value_inum)
2918 continue;
2919 error = ext4_xattr_inode_iget(inode,
2920 le32_to_cpu(entry->e_value_inum),
2921 le32_to_cpu(entry->e_hash),
2922 &ea_inode);
2923 if (error)
2924 continue;
2925 ext4_xattr_inode_free_quota(inode, ea_inode,
2926 le32_to_cpu(entry->e_value_size));
2927 iput(ea_inode);
2928 }
2929
2930 }
2931
2932 ext4_xattr_release_block(handle, inode, bh, ea_inode_array,
2933 extra_credits);
2934 /*
2935 * Update i_file_acl value in the same transaction that releases
2936 * block.
2937 */
2938 EXT4_I(inode)->i_file_acl = 0;
2939 error = ext4_mark_inode_dirty(handle, inode);
2940 if (error) {
2941 EXT4_ERROR_INODE(inode, "mark inode dirty (error %d)",
2942 error);
2943 goto cleanup;
2944 }
2945 }
2946 error = 0;
2947cleanup:
2948 brelse(iloc.bh);
2949 brelse(bh);
2950 return error;
2951}
2952
2953void ext4_xattr_inode_array_free(struct ext4_xattr_inode_array *ea_inode_array)
2954{
2955 int idx;
2956
2957 if (ea_inode_array == NULL)
2958 return;
2959
2960 for (idx = 0; idx < ea_inode_array->count; ++idx)
2961 iput(ea_inode_array->inodes[idx]);
2962 kfree(ea_inode_array);
2963}
2964
2965/*
2966 * ext4_xattr_block_cache_insert()
2967 *
2968 * Create a new entry in the extended attribute block cache, and insert
2969 * it unless such an entry is already in the cache.
2970 *
2971 * Returns 0, or a negative error number on failure.
2972 */
2973static void
2974ext4_xattr_block_cache_insert(struct mb_cache *ea_block_cache,
2975 struct buffer_head *bh)
2976{
2977 struct ext4_xattr_header *header = BHDR(bh);
2978 __u32 hash = le32_to_cpu(header->h_hash);
2979 int reusable = le32_to_cpu(header->h_refcount) <
2980 EXT4_XATTR_REFCOUNT_MAX;
2981 int error;
2982
2983 if (!ea_block_cache)
2984 return;
2985 error = mb_cache_entry_create(ea_block_cache, GFP_NOFS, hash,
2986 bh->b_blocknr, reusable);
2987 if (error) {
2988 if (error == -EBUSY)
2989 ea_bdebug(bh, "already in cache");
2990 } else
2991 ea_bdebug(bh, "inserting [%x]", (int)hash);
2992}
2993
2994/*
2995 * ext4_xattr_cmp()
2996 *
2997 * Compare two extended attribute blocks for equality.
2998 *
2999 * Returns 0 if the blocks are equal, 1 if they differ, and
3000 * a negative error number on errors.
3001 */
3002static int
3003ext4_xattr_cmp(struct ext4_xattr_header *header1,
3004 struct ext4_xattr_header *header2)
3005{
3006 struct ext4_xattr_entry *entry1, *entry2;
3007
3008 entry1 = ENTRY(header1+1);
3009 entry2 = ENTRY(header2+1);
3010 while (!IS_LAST_ENTRY(entry1)) {
3011 if (IS_LAST_ENTRY(entry2))
3012 return 1;
3013 if (entry1->e_hash != entry2->e_hash ||
3014 entry1->e_name_index != entry2->e_name_index ||
3015 entry1->e_name_len != entry2->e_name_len ||
3016 entry1->e_value_size != entry2->e_value_size ||
3017 entry1->e_value_inum != entry2->e_value_inum ||
3018 memcmp(entry1->e_name, entry2->e_name, entry1->e_name_len))
3019 return 1;
3020 if (!entry1->e_value_inum &&
3021 memcmp((char *)header1 + le16_to_cpu(entry1->e_value_offs),
3022 (char *)header2 + le16_to_cpu(entry2->e_value_offs),
3023 le32_to_cpu(entry1->e_value_size)))
3024 return 1;
3025
3026 entry1 = EXT4_XATTR_NEXT(entry1);
3027 entry2 = EXT4_XATTR_NEXT(entry2);
3028 }
3029 if (!IS_LAST_ENTRY(entry2))
3030 return 1;
3031 return 0;
3032}
3033
3034/*
3035 * ext4_xattr_block_cache_find()
3036 *
3037 * Find an identical extended attribute block.
3038 *
3039 * Returns a pointer to the block found, or NULL if such a block was
3040 * not found or an error occurred.
3041 */
3042static struct buffer_head *
3043ext4_xattr_block_cache_find(struct inode *inode,
3044 struct ext4_xattr_header *header,
3045 struct mb_cache_entry **pce)
3046{
3047 __u32 hash = le32_to_cpu(header->h_hash);
3048 struct mb_cache_entry *ce;
3049 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
3050
3051 if (!ea_block_cache)
3052 return NULL;
3053 if (!header->h_hash)
3054 return NULL; /* never share */
3055 ea_idebug(inode, "looking for cached blocks [%x]", (int)hash);
3056 ce = mb_cache_entry_find_first(ea_block_cache, hash);
3057 while (ce) {
3058 struct buffer_head *bh;
3059
3060 bh = ext4_sb_bread(inode->i_sb, ce->e_value, REQ_PRIO);
3061 if (IS_ERR(bh)) {
3062 if (PTR_ERR(bh) == -ENOMEM)
3063 return NULL;
3064 bh = NULL;
3065 EXT4_ERROR_INODE(inode, "block %lu read error",
3066 (unsigned long)ce->e_value);
3067 } else if (ext4_xattr_cmp(header, BHDR(bh)) == 0) {
3068 *pce = ce;
3069 return bh;
3070 }
3071 brelse(bh);
3072 ce = mb_cache_entry_find_next(ea_block_cache, ce);
3073 }
3074 return NULL;
3075}
3076
3077#define NAME_HASH_SHIFT 5
3078#define VALUE_HASH_SHIFT 16
3079
3080/*
3081 * ext4_xattr_hash_entry()
3082 *
3083 * Compute the hash of an extended attribute.
3084 */
3085static __le32 ext4_xattr_hash_entry(char *name, size_t name_len, __le32 *value,
3086 size_t value_count)
3087{
3088 __u32 hash = 0;
3089
3090 while (name_len--) {
3091 hash = (hash << NAME_HASH_SHIFT) ^
3092 (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^
3093 *name++;
3094 }
3095 while (value_count--) {
3096 hash = (hash << VALUE_HASH_SHIFT) ^
3097 (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^
3098 le32_to_cpu(*value++);
3099 }
3100 return cpu_to_le32(hash);
3101}
3102
3103#undef NAME_HASH_SHIFT
3104#undef VALUE_HASH_SHIFT
3105
3106#define BLOCK_HASH_SHIFT 16
3107
3108/*
3109 * ext4_xattr_rehash()
3110 *
3111 * Re-compute the extended attribute hash value after an entry has changed.
3112 */
3113static void ext4_xattr_rehash(struct ext4_xattr_header *header)
3114{
3115 struct ext4_xattr_entry *here;
3116 __u32 hash = 0;
3117
3118 here = ENTRY(header+1);
3119 while (!IS_LAST_ENTRY(here)) {
3120 if (!here->e_hash) {
3121 /* Block is not shared if an entry's hash value == 0 */
3122 hash = 0;
3123 break;
3124 }
3125 hash = (hash << BLOCK_HASH_SHIFT) ^
3126 (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^
3127 le32_to_cpu(here->e_hash);
3128 here = EXT4_XATTR_NEXT(here);
3129 }
3130 header->h_hash = cpu_to_le32(hash);
3131}
3132
3133#undef BLOCK_HASH_SHIFT
3134
3135#define HASH_BUCKET_BITS 10
3136
3137struct mb_cache *
3138ext4_xattr_create_cache(void)
3139{
3140 return mb_cache_create(HASH_BUCKET_BITS);
3141}
3142
3143void ext4_xattr_destroy_cache(struct mb_cache *cache)
3144{
3145 if (cache)
3146 mb_cache_destroy(cache);
3147}
3148