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1/*
2 * linux/fs/ext4/xattr.c
3 *
4 * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
5 *
6 * Fix by Harrison Xing <harrison@mountainviewdata.com>.
7 * Ext4 code with a lot of help from Eric Jarman <ejarman@acm.org>.
8 * Extended attributes for symlinks and special files added per
9 * suggestion of Luka Renko <luka.renko@hermes.si>.
10 * xattr consolidation Copyright (c) 2004 James Morris <jmorris@redhat.com>,
11 * Red Hat Inc.
12 * ea-in-inode support by Alex Tomas <alex@clusterfs.com> aka bzzz
13 * and Andreas Gruenbacher <agruen@suse.de>.
14 */
15
16/*
17 * Extended attributes are stored directly in inodes (on file systems with
18 * inodes bigger than 128 bytes) and on additional disk blocks. The i_file_acl
19 * field contains the block number if an inode uses an additional block. All
20 * attributes must fit in the inode and one additional block. Blocks that
21 * contain the identical set of attributes may be shared among several inodes.
22 * Identical blocks are detected by keeping a cache of blocks that have
23 * recently been accessed.
24 *
25 * The attributes in inodes and on blocks have a different header; the entries
26 * are stored in the same format:
27 *
28 * +------------------+
29 * | header |
30 * | entry 1 | |
31 * | entry 2 | | growing downwards
32 * | entry 3 | v
33 * | four null bytes |
34 * | . . . |
35 * | value 1 | ^
36 * | value 3 | | growing upwards
37 * | value 2 | |
38 * +------------------+
39 *
40 * The header is followed by multiple entry descriptors. In disk blocks, the
41 * entry descriptors are kept sorted. In inodes, they are unsorted. The
42 * attribute values are aligned to the end of the block in no specific order.
43 *
44 * Locking strategy
45 * ----------------
46 * EXT4_I(inode)->i_file_acl is protected by EXT4_I(inode)->xattr_sem.
47 * EA blocks are only changed if they are exclusive to an inode, so
48 * holding xattr_sem also means that nothing but the EA block's reference
49 * count can change. Multiple writers to the same block are synchronized
50 * by the buffer lock.
51 */
52
53#include <linux/init.h>
54#include <linux/fs.h>
55#include <linux/slab.h>
56#include <linux/mbcache.h>
57#include <linux/quotaops.h>
58#include <linux/rwsem.h>
59#include "ext4_jbd2.h"
60#include "ext4.h"
61#include "xattr.h"
62#include "acl.h"
63
64#define BHDR(bh) ((struct ext4_xattr_header *)((bh)->b_data))
65#define ENTRY(ptr) ((struct ext4_xattr_entry *)(ptr))
66#define BFIRST(bh) ENTRY(BHDR(bh)+1)
67#define IS_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0)
68
69#ifdef EXT4_XATTR_DEBUG
70# define ea_idebug(inode, f...) do { \
71 printk(KERN_DEBUG "inode %s:%lu: ", \
72 inode->i_sb->s_id, inode->i_ino); \
73 printk(f); \
74 printk("\n"); \
75 } while (0)
76# define ea_bdebug(bh, f...) do { \
77 char b[BDEVNAME_SIZE]; \
78 printk(KERN_DEBUG "block %s:%lu: ", \
79 bdevname(bh->b_bdev, b), \
80 (unsigned long) bh->b_blocknr); \
81 printk(f); \
82 printk("\n"); \
83 } while (0)
84#else
85# define ea_idebug(inode, fmt, ...) no_printk(fmt, ##__VA_ARGS__)
86# define ea_bdebug(bh, fmt, ...) no_printk(fmt, ##__VA_ARGS__)
87#endif
88
89static void ext4_xattr_cache_insert(struct buffer_head *);
90static struct buffer_head *ext4_xattr_cache_find(struct inode *,
91 struct ext4_xattr_header *,
92 struct mb_cache_entry **);
93static void ext4_xattr_rehash(struct ext4_xattr_header *,
94 struct ext4_xattr_entry *);
95static int ext4_xattr_list(struct dentry *dentry, char *buffer,
96 size_t buffer_size);
97
98static struct mb_cache *ext4_xattr_cache;
99
100static const struct xattr_handler *ext4_xattr_handler_map[] = {
101 [EXT4_XATTR_INDEX_USER] = &ext4_xattr_user_handler,
102#ifdef CONFIG_EXT4_FS_POSIX_ACL
103 [EXT4_XATTR_INDEX_POSIX_ACL_ACCESS] = &ext4_xattr_acl_access_handler,
104 [EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT] = &ext4_xattr_acl_default_handler,
105#endif
106 [EXT4_XATTR_INDEX_TRUSTED] = &ext4_xattr_trusted_handler,
107#ifdef CONFIG_EXT4_FS_SECURITY
108 [EXT4_XATTR_INDEX_SECURITY] = &ext4_xattr_security_handler,
109#endif
110};
111
112const struct xattr_handler *ext4_xattr_handlers[] = {
113 &ext4_xattr_user_handler,
114 &ext4_xattr_trusted_handler,
115#ifdef CONFIG_EXT4_FS_POSIX_ACL
116 &ext4_xattr_acl_access_handler,
117 &ext4_xattr_acl_default_handler,
118#endif
119#ifdef CONFIG_EXT4_FS_SECURITY
120 &ext4_xattr_security_handler,
121#endif
122 NULL
123};
124
125static __le32 ext4_xattr_block_csum(struct inode *inode,
126 sector_t block_nr,
127 struct ext4_xattr_header *hdr)
128{
129 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
130 __u32 csum, old;
131
132 old = hdr->h_checksum;
133 hdr->h_checksum = 0;
134 block_nr = cpu_to_le64(block_nr);
135 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&block_nr,
136 sizeof(block_nr));
137 csum = ext4_chksum(sbi, csum, (__u8 *)hdr,
138 EXT4_BLOCK_SIZE(inode->i_sb));
139
140 hdr->h_checksum = old;
141 return cpu_to_le32(csum);
142}
143
144static int ext4_xattr_block_csum_verify(struct inode *inode,
145 sector_t block_nr,
146 struct ext4_xattr_header *hdr)
147{
148 if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
149 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
150 (hdr->h_checksum != ext4_xattr_block_csum(inode, block_nr, hdr)))
151 return 0;
152 return 1;
153}
154
155static void ext4_xattr_block_csum_set(struct inode *inode,
156 sector_t block_nr,
157 struct ext4_xattr_header *hdr)
158{
159 if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
160 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
161 return;
162
163 hdr->h_checksum = ext4_xattr_block_csum(inode, block_nr, hdr);
164}
165
166static inline int ext4_handle_dirty_xattr_block(handle_t *handle,
167 struct inode *inode,
168 struct buffer_head *bh)
169{
170 ext4_xattr_block_csum_set(inode, bh->b_blocknr, BHDR(bh));
171 return ext4_handle_dirty_metadata(handle, inode, bh);
172}
173
174static inline const struct xattr_handler *
175ext4_xattr_handler(int name_index)
176{
177 const struct xattr_handler *handler = NULL;
178
179 if (name_index > 0 && name_index < ARRAY_SIZE(ext4_xattr_handler_map))
180 handler = ext4_xattr_handler_map[name_index];
181 return handler;
182}
183
184/*
185 * Inode operation listxattr()
186 *
187 * dentry->d_inode->i_mutex: don't care
188 */
189ssize_t
190ext4_listxattr(struct dentry *dentry, char *buffer, size_t size)
191{
192 return ext4_xattr_list(dentry, buffer, size);
193}
194
195static int
196ext4_xattr_check_names(struct ext4_xattr_entry *entry, void *end)
197{
198 while (!IS_LAST_ENTRY(entry)) {
199 struct ext4_xattr_entry *next = EXT4_XATTR_NEXT(entry);
200 if ((void *)next >= end)
201 return -EIO;
202 entry = next;
203 }
204 return 0;
205}
206
207static inline int
208ext4_xattr_check_block(struct inode *inode, struct buffer_head *bh)
209{
210 int error;
211
212 if (buffer_verified(bh))
213 return 0;
214
215 if (BHDR(bh)->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC) ||
216 BHDR(bh)->h_blocks != cpu_to_le32(1))
217 return -EIO;
218 if (!ext4_xattr_block_csum_verify(inode, bh->b_blocknr, BHDR(bh)))
219 return -EIO;
220 error = ext4_xattr_check_names(BFIRST(bh), bh->b_data + bh->b_size);
221 if (!error)
222 set_buffer_verified(bh);
223 return error;
224}
225
226static inline int
227ext4_xattr_check_entry(struct ext4_xattr_entry *entry, size_t size)
228{
229 size_t value_size = le32_to_cpu(entry->e_value_size);
230
231 if (entry->e_value_block != 0 || value_size > size ||
232 le16_to_cpu(entry->e_value_offs) + value_size > size)
233 return -EIO;
234 return 0;
235}
236
237static int
238ext4_xattr_find_entry(struct ext4_xattr_entry **pentry, int name_index,
239 const char *name, size_t size, int sorted)
240{
241 struct ext4_xattr_entry *entry;
242 size_t name_len;
243 int cmp = 1;
244
245 if (name == NULL)
246 return -EINVAL;
247 name_len = strlen(name);
248 entry = *pentry;
249 for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) {
250 cmp = name_index - entry->e_name_index;
251 if (!cmp)
252 cmp = name_len - entry->e_name_len;
253 if (!cmp)
254 cmp = memcmp(name, entry->e_name, name_len);
255 if (cmp <= 0 && (sorted || cmp == 0))
256 break;
257 }
258 *pentry = entry;
259 if (!cmp && ext4_xattr_check_entry(entry, size))
260 return -EIO;
261 return cmp ? -ENODATA : 0;
262}
263
264static int
265ext4_xattr_block_get(struct inode *inode, int name_index, const char *name,
266 void *buffer, size_t buffer_size)
267{
268 struct buffer_head *bh = NULL;
269 struct ext4_xattr_entry *entry;
270 size_t size;
271 int error;
272
273 ea_idebug(inode, "name=%d.%s, buffer=%p, buffer_size=%ld",
274 name_index, name, buffer, (long)buffer_size);
275
276 error = -ENODATA;
277 if (!EXT4_I(inode)->i_file_acl)
278 goto cleanup;
279 ea_idebug(inode, "reading block %llu",
280 (unsigned long long)EXT4_I(inode)->i_file_acl);
281 bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl);
282 if (!bh)
283 goto cleanup;
284 ea_bdebug(bh, "b_count=%d, refcount=%d",
285 atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount));
286 if (ext4_xattr_check_block(inode, bh)) {
287bad_block:
288 EXT4_ERROR_INODE(inode, "bad block %llu",
289 EXT4_I(inode)->i_file_acl);
290 error = -EIO;
291 goto cleanup;
292 }
293 ext4_xattr_cache_insert(bh);
294 entry = BFIRST(bh);
295 error = ext4_xattr_find_entry(&entry, name_index, name, bh->b_size, 1);
296 if (error == -EIO)
297 goto bad_block;
298 if (error)
299 goto cleanup;
300 size = le32_to_cpu(entry->e_value_size);
301 if (buffer) {
302 error = -ERANGE;
303 if (size > buffer_size)
304 goto cleanup;
305 memcpy(buffer, bh->b_data + le16_to_cpu(entry->e_value_offs),
306 size);
307 }
308 error = size;
309
310cleanup:
311 brelse(bh);
312 return error;
313}
314
315static int
316ext4_xattr_ibody_get(struct inode *inode, int name_index, const char *name,
317 void *buffer, size_t buffer_size)
318{
319 struct ext4_xattr_ibody_header *header;
320 struct ext4_xattr_entry *entry;
321 struct ext4_inode *raw_inode;
322 struct ext4_iloc iloc;
323 size_t size;
324 void *end;
325 int error;
326
327 if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR))
328 return -ENODATA;
329 error = ext4_get_inode_loc(inode, &iloc);
330 if (error)
331 return error;
332 raw_inode = ext4_raw_inode(&iloc);
333 header = IHDR(inode, raw_inode);
334 entry = IFIRST(header);
335 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
336 error = ext4_xattr_check_names(entry, end);
337 if (error)
338 goto cleanup;
339 error = ext4_xattr_find_entry(&entry, name_index, name,
340 end - (void *)entry, 0);
341 if (error)
342 goto cleanup;
343 size = le32_to_cpu(entry->e_value_size);
344 if (buffer) {
345 error = -ERANGE;
346 if (size > buffer_size)
347 goto cleanup;
348 memcpy(buffer, (void *)IFIRST(header) +
349 le16_to_cpu(entry->e_value_offs), size);
350 }
351 error = size;
352
353cleanup:
354 brelse(iloc.bh);
355 return error;
356}
357
358/*
359 * ext4_xattr_get()
360 *
361 * Copy an extended attribute into the buffer
362 * provided, or compute the buffer size required.
363 * Buffer is NULL to compute the size of the buffer required.
364 *
365 * Returns a negative error number on failure, or the number of bytes
366 * used / required on success.
367 */
368int
369ext4_xattr_get(struct inode *inode, int name_index, const char *name,
370 void *buffer, size_t buffer_size)
371{
372 int error;
373
374 down_read(&EXT4_I(inode)->xattr_sem);
375 error = ext4_xattr_ibody_get(inode, name_index, name, buffer,
376 buffer_size);
377 if (error == -ENODATA)
378 error = ext4_xattr_block_get(inode, name_index, name, buffer,
379 buffer_size);
380 up_read(&EXT4_I(inode)->xattr_sem);
381 return error;
382}
383
384static int
385ext4_xattr_list_entries(struct dentry *dentry, struct ext4_xattr_entry *entry,
386 char *buffer, size_t buffer_size)
387{
388 size_t rest = buffer_size;
389
390 for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) {
391 const struct xattr_handler *handler =
392 ext4_xattr_handler(entry->e_name_index);
393
394 if (handler) {
395 size_t size = handler->list(dentry, buffer, rest,
396 entry->e_name,
397 entry->e_name_len,
398 handler->flags);
399 if (buffer) {
400 if (size > rest)
401 return -ERANGE;
402 buffer += size;
403 }
404 rest -= size;
405 }
406 }
407 return buffer_size - rest;
408}
409
410static int
411ext4_xattr_block_list(struct dentry *dentry, char *buffer, size_t buffer_size)
412{
413 struct inode *inode = dentry->d_inode;
414 struct buffer_head *bh = NULL;
415 int error;
416
417 ea_idebug(inode, "buffer=%p, buffer_size=%ld",
418 buffer, (long)buffer_size);
419
420 error = 0;
421 if (!EXT4_I(inode)->i_file_acl)
422 goto cleanup;
423 ea_idebug(inode, "reading block %llu",
424 (unsigned long long)EXT4_I(inode)->i_file_acl);
425 bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl);
426 error = -EIO;
427 if (!bh)
428 goto cleanup;
429 ea_bdebug(bh, "b_count=%d, refcount=%d",
430 atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount));
431 if (ext4_xattr_check_block(inode, bh)) {
432 EXT4_ERROR_INODE(inode, "bad block %llu",
433 EXT4_I(inode)->i_file_acl);
434 error = -EIO;
435 goto cleanup;
436 }
437 ext4_xattr_cache_insert(bh);
438 error = ext4_xattr_list_entries(dentry, BFIRST(bh), buffer, buffer_size);
439
440cleanup:
441 brelse(bh);
442
443 return error;
444}
445
446static int
447ext4_xattr_ibody_list(struct dentry *dentry, char *buffer, size_t buffer_size)
448{
449 struct inode *inode = dentry->d_inode;
450 struct ext4_xattr_ibody_header *header;
451 struct ext4_inode *raw_inode;
452 struct ext4_iloc iloc;
453 void *end;
454 int error;
455
456 if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR))
457 return 0;
458 error = ext4_get_inode_loc(inode, &iloc);
459 if (error)
460 return error;
461 raw_inode = ext4_raw_inode(&iloc);
462 header = IHDR(inode, raw_inode);
463 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
464 error = ext4_xattr_check_names(IFIRST(header), end);
465 if (error)
466 goto cleanup;
467 error = ext4_xattr_list_entries(dentry, IFIRST(header),
468 buffer, buffer_size);
469
470cleanup:
471 brelse(iloc.bh);
472 return error;
473}
474
475/*
476 * ext4_xattr_list()
477 *
478 * Copy a list of attribute names into the buffer
479 * provided, or compute the buffer size required.
480 * Buffer is NULL to compute the size of the buffer required.
481 *
482 * Returns a negative error number on failure, or the number of bytes
483 * used / required on success.
484 */
485static int
486ext4_xattr_list(struct dentry *dentry, char *buffer, size_t buffer_size)
487{
488 int ret, ret2;
489
490 down_read(&EXT4_I(dentry->d_inode)->xattr_sem);
491 ret = ret2 = ext4_xattr_ibody_list(dentry, buffer, buffer_size);
492 if (ret < 0)
493 goto errout;
494 if (buffer) {
495 buffer += ret;
496 buffer_size -= ret;
497 }
498 ret = ext4_xattr_block_list(dentry, buffer, buffer_size);
499 if (ret < 0)
500 goto errout;
501 ret += ret2;
502errout:
503 up_read(&EXT4_I(dentry->d_inode)->xattr_sem);
504 return ret;
505}
506
507/*
508 * If the EXT4_FEATURE_COMPAT_EXT_ATTR feature of this file system is
509 * not set, set it.
510 */
511static void ext4_xattr_update_super_block(handle_t *handle,
512 struct super_block *sb)
513{
514 if (EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_EXT_ATTR))
515 return;
516
517 if (ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh) == 0) {
518 EXT4_SET_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_EXT_ATTR);
519 ext4_handle_dirty_super(handle, sb);
520 }
521}
522
523/*
524 * Release the xattr block BH: If the reference count is > 1, decrement
525 * it; otherwise free the block.
526 */
527static void
528ext4_xattr_release_block(handle_t *handle, struct inode *inode,
529 struct buffer_head *bh)
530{
531 struct mb_cache_entry *ce = NULL;
532 int error = 0;
533
534 ce = mb_cache_entry_get(ext4_xattr_cache, bh->b_bdev, bh->b_blocknr);
535 error = ext4_journal_get_write_access(handle, bh);
536 if (error)
537 goto out;
538
539 lock_buffer(bh);
540 if (BHDR(bh)->h_refcount == cpu_to_le32(1)) {
541 ea_bdebug(bh, "refcount now=0; freeing");
542 if (ce)
543 mb_cache_entry_free(ce);
544 get_bh(bh);
545 ext4_free_blocks(handle, inode, bh, 0, 1,
546 EXT4_FREE_BLOCKS_METADATA |
547 EXT4_FREE_BLOCKS_FORGET);
548 unlock_buffer(bh);
549 } else {
550 le32_add_cpu(&BHDR(bh)->h_refcount, -1);
551 if (ce)
552 mb_cache_entry_release(ce);
553 unlock_buffer(bh);
554 error = ext4_handle_dirty_xattr_block(handle, inode, bh);
555 if (IS_SYNC(inode))
556 ext4_handle_sync(handle);
557 dquot_free_block(inode, 1);
558 ea_bdebug(bh, "refcount now=%d; releasing",
559 le32_to_cpu(BHDR(bh)->h_refcount));
560 }
561out:
562 ext4_std_error(inode->i_sb, error);
563 return;
564}
565
566/*
567 * Find the available free space for EAs. This also returns the total number of
568 * bytes used by EA entries.
569 */
570static size_t ext4_xattr_free_space(struct ext4_xattr_entry *last,
571 size_t *min_offs, void *base, int *total)
572{
573 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
574 *total += EXT4_XATTR_LEN(last->e_name_len);
575 if (!last->e_value_block && last->e_value_size) {
576 size_t offs = le16_to_cpu(last->e_value_offs);
577 if (offs < *min_offs)
578 *min_offs = offs;
579 }
580 }
581 return (*min_offs - ((void *)last - base) - sizeof(__u32));
582}
583
584struct ext4_xattr_info {
585 int name_index;
586 const char *name;
587 const void *value;
588 size_t value_len;
589};
590
591struct ext4_xattr_search {
592 struct ext4_xattr_entry *first;
593 void *base;
594 void *end;
595 struct ext4_xattr_entry *here;
596 int not_found;
597};
598
599static int
600ext4_xattr_set_entry(struct ext4_xattr_info *i, struct ext4_xattr_search *s)
601{
602 struct ext4_xattr_entry *last;
603 size_t free, min_offs = s->end - s->base, name_len = strlen(i->name);
604
605 /* Compute min_offs and last. */
606 last = s->first;
607 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
608 if (!last->e_value_block && last->e_value_size) {
609 size_t offs = le16_to_cpu(last->e_value_offs);
610 if (offs < min_offs)
611 min_offs = offs;
612 }
613 }
614 free = min_offs - ((void *)last - s->base) - sizeof(__u32);
615 if (!s->not_found) {
616 if (!s->here->e_value_block && s->here->e_value_size) {
617 size_t size = le32_to_cpu(s->here->e_value_size);
618 free += EXT4_XATTR_SIZE(size);
619 }
620 free += EXT4_XATTR_LEN(name_len);
621 }
622 if (i->value) {
623 if (free < EXT4_XATTR_SIZE(i->value_len) ||
624 free < EXT4_XATTR_LEN(name_len) +
625 EXT4_XATTR_SIZE(i->value_len))
626 return -ENOSPC;
627 }
628
629 if (i->value && s->not_found) {
630 /* Insert the new name. */
631 size_t size = EXT4_XATTR_LEN(name_len);
632 size_t rest = (void *)last - (void *)s->here + sizeof(__u32);
633 memmove((void *)s->here + size, s->here, rest);
634 memset(s->here, 0, size);
635 s->here->e_name_index = i->name_index;
636 s->here->e_name_len = name_len;
637 memcpy(s->here->e_name, i->name, name_len);
638 } else {
639 if (!s->here->e_value_block && s->here->e_value_size) {
640 void *first_val = s->base + min_offs;
641 size_t offs = le16_to_cpu(s->here->e_value_offs);
642 void *val = s->base + offs;
643 size_t size = EXT4_XATTR_SIZE(
644 le32_to_cpu(s->here->e_value_size));
645
646 if (i->value && size == EXT4_XATTR_SIZE(i->value_len)) {
647 /* The old and the new value have the same
648 size. Just replace. */
649 s->here->e_value_size =
650 cpu_to_le32(i->value_len);
651 memset(val + size - EXT4_XATTR_PAD, 0,
652 EXT4_XATTR_PAD); /* Clear pad bytes. */
653 memcpy(val, i->value, i->value_len);
654 return 0;
655 }
656
657 /* Remove the old value. */
658 memmove(first_val + size, first_val, val - first_val);
659 memset(first_val, 0, size);
660 s->here->e_value_size = 0;
661 s->here->e_value_offs = 0;
662 min_offs += size;
663
664 /* Adjust all value offsets. */
665 last = s->first;
666 while (!IS_LAST_ENTRY(last)) {
667 size_t o = le16_to_cpu(last->e_value_offs);
668 if (!last->e_value_block &&
669 last->e_value_size && o < offs)
670 last->e_value_offs =
671 cpu_to_le16(o + size);
672 last = EXT4_XATTR_NEXT(last);
673 }
674 }
675 if (!i->value) {
676 /* Remove the old name. */
677 size_t size = EXT4_XATTR_LEN(name_len);
678 last = ENTRY((void *)last - size);
679 memmove(s->here, (void *)s->here + size,
680 (void *)last - (void *)s->here + sizeof(__u32));
681 memset(last, 0, size);
682 }
683 }
684
685 if (i->value) {
686 /* Insert the new value. */
687 s->here->e_value_size = cpu_to_le32(i->value_len);
688 if (i->value_len) {
689 size_t size = EXT4_XATTR_SIZE(i->value_len);
690 void *val = s->base + min_offs - size;
691 s->here->e_value_offs = cpu_to_le16(min_offs - size);
692 memset(val + size - EXT4_XATTR_PAD, 0,
693 EXT4_XATTR_PAD); /* Clear the pad bytes. */
694 memcpy(val, i->value, i->value_len);
695 }
696 }
697 return 0;
698}
699
700struct ext4_xattr_block_find {
701 struct ext4_xattr_search s;
702 struct buffer_head *bh;
703};
704
705static int
706ext4_xattr_block_find(struct inode *inode, struct ext4_xattr_info *i,
707 struct ext4_xattr_block_find *bs)
708{
709 struct super_block *sb = inode->i_sb;
710 int error;
711
712 ea_idebug(inode, "name=%d.%s, value=%p, value_len=%ld",
713 i->name_index, i->name, i->value, (long)i->value_len);
714
715 if (EXT4_I(inode)->i_file_acl) {
716 /* The inode already has an extended attribute block. */
717 bs->bh = sb_bread(sb, EXT4_I(inode)->i_file_acl);
718 error = -EIO;
719 if (!bs->bh)
720 goto cleanup;
721 ea_bdebug(bs->bh, "b_count=%d, refcount=%d",
722 atomic_read(&(bs->bh->b_count)),
723 le32_to_cpu(BHDR(bs->bh)->h_refcount));
724 if (ext4_xattr_check_block(inode, bs->bh)) {
725 EXT4_ERROR_INODE(inode, "bad block %llu",
726 EXT4_I(inode)->i_file_acl);
727 error = -EIO;
728 goto cleanup;
729 }
730 /* Find the named attribute. */
731 bs->s.base = BHDR(bs->bh);
732 bs->s.first = BFIRST(bs->bh);
733 bs->s.end = bs->bh->b_data + bs->bh->b_size;
734 bs->s.here = bs->s.first;
735 error = ext4_xattr_find_entry(&bs->s.here, i->name_index,
736 i->name, bs->bh->b_size, 1);
737 if (error && error != -ENODATA)
738 goto cleanup;
739 bs->s.not_found = error;
740 }
741 error = 0;
742
743cleanup:
744 return error;
745}
746
747static int
748ext4_xattr_block_set(handle_t *handle, struct inode *inode,
749 struct ext4_xattr_info *i,
750 struct ext4_xattr_block_find *bs)
751{
752 struct super_block *sb = inode->i_sb;
753 struct buffer_head *new_bh = NULL;
754 struct ext4_xattr_search *s = &bs->s;
755 struct mb_cache_entry *ce = NULL;
756 int error = 0;
757
758#define header(x) ((struct ext4_xattr_header *)(x))
759
760 if (i->value && i->value_len > sb->s_blocksize)
761 return -ENOSPC;
762 if (s->base) {
763 ce = mb_cache_entry_get(ext4_xattr_cache, bs->bh->b_bdev,
764 bs->bh->b_blocknr);
765 error = ext4_journal_get_write_access(handle, bs->bh);
766 if (error)
767 goto cleanup;
768 lock_buffer(bs->bh);
769
770 if (header(s->base)->h_refcount == cpu_to_le32(1)) {
771 if (ce) {
772 mb_cache_entry_free(ce);
773 ce = NULL;
774 }
775 ea_bdebug(bs->bh, "modifying in-place");
776 error = ext4_xattr_set_entry(i, s);
777 if (!error) {
778 if (!IS_LAST_ENTRY(s->first))
779 ext4_xattr_rehash(header(s->base),
780 s->here);
781 ext4_xattr_cache_insert(bs->bh);
782 }
783 unlock_buffer(bs->bh);
784 if (error == -EIO)
785 goto bad_block;
786 if (!error)
787 error = ext4_handle_dirty_xattr_block(handle,
788 inode,
789 bs->bh);
790 if (error)
791 goto cleanup;
792 goto inserted;
793 } else {
794 int offset = (char *)s->here - bs->bh->b_data;
795
796 unlock_buffer(bs->bh);
797 ext4_handle_release_buffer(handle, bs->bh);
798 if (ce) {
799 mb_cache_entry_release(ce);
800 ce = NULL;
801 }
802 ea_bdebug(bs->bh, "cloning");
803 s->base = kmalloc(bs->bh->b_size, GFP_NOFS);
804 error = -ENOMEM;
805 if (s->base == NULL)
806 goto cleanup;
807 memcpy(s->base, BHDR(bs->bh), bs->bh->b_size);
808 s->first = ENTRY(header(s->base)+1);
809 header(s->base)->h_refcount = cpu_to_le32(1);
810 s->here = ENTRY(s->base + offset);
811 s->end = s->base + bs->bh->b_size;
812 }
813 } else {
814 /* Allocate a buffer where we construct the new block. */
815 s->base = kzalloc(sb->s_blocksize, GFP_NOFS);
816 /* assert(header == s->base) */
817 error = -ENOMEM;
818 if (s->base == NULL)
819 goto cleanup;
820 header(s->base)->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
821 header(s->base)->h_blocks = cpu_to_le32(1);
822 header(s->base)->h_refcount = cpu_to_le32(1);
823 s->first = ENTRY(header(s->base)+1);
824 s->here = ENTRY(header(s->base)+1);
825 s->end = s->base + sb->s_blocksize;
826 }
827
828 error = ext4_xattr_set_entry(i, s);
829 if (error == -EIO)
830 goto bad_block;
831 if (error)
832 goto cleanup;
833 if (!IS_LAST_ENTRY(s->first))
834 ext4_xattr_rehash(header(s->base), s->here);
835
836inserted:
837 if (!IS_LAST_ENTRY(s->first)) {
838 new_bh = ext4_xattr_cache_find(inode, header(s->base), &ce);
839 if (new_bh) {
840 /* We found an identical block in the cache. */
841 if (new_bh == bs->bh)
842 ea_bdebug(new_bh, "keeping");
843 else {
844 /* The old block is released after updating
845 the inode. */
846 error = dquot_alloc_block(inode, 1);
847 if (error)
848 goto cleanup;
849 error = ext4_journal_get_write_access(handle,
850 new_bh);
851 if (error)
852 goto cleanup_dquot;
853 lock_buffer(new_bh);
854 le32_add_cpu(&BHDR(new_bh)->h_refcount, 1);
855 ea_bdebug(new_bh, "reusing; refcount now=%d",
856 le32_to_cpu(BHDR(new_bh)->h_refcount));
857 unlock_buffer(new_bh);
858 error = ext4_handle_dirty_xattr_block(handle,
859 inode,
860 new_bh);
861 if (error)
862 goto cleanup_dquot;
863 }
864 mb_cache_entry_release(ce);
865 ce = NULL;
866 } else if (bs->bh && s->base == bs->bh->b_data) {
867 /* We were modifying this block in-place. */
868 ea_bdebug(bs->bh, "keeping this block");
869 new_bh = bs->bh;
870 get_bh(new_bh);
871 } else {
872 /* We need to allocate a new block */
873 ext4_fsblk_t goal, block;
874
875 goal = ext4_group_first_block_no(sb,
876 EXT4_I(inode)->i_block_group);
877
878 /* non-extent files can't have physical blocks past 2^32 */
879 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
880 goal = goal & EXT4_MAX_BLOCK_FILE_PHYS;
881
882 /*
883 * take i_data_sem because we will test
884 * i_delalloc_reserved_flag in ext4_mb_new_blocks
885 */
886 down_read((&EXT4_I(inode)->i_data_sem));
887 block = ext4_new_meta_blocks(handle, inode, goal, 0,
888 NULL, &error);
889 up_read((&EXT4_I(inode)->i_data_sem));
890 if (error)
891 goto cleanup;
892
893 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
894 BUG_ON(block > EXT4_MAX_BLOCK_FILE_PHYS);
895
896 ea_idebug(inode, "creating block %llu",
897 (unsigned long long)block);
898
899 new_bh = sb_getblk(sb, block);
900 if (!new_bh) {
901getblk_failed:
902 ext4_free_blocks(handle, inode, NULL, block, 1,
903 EXT4_FREE_BLOCKS_METADATA);
904 error = -EIO;
905 goto cleanup;
906 }
907 lock_buffer(new_bh);
908 error = ext4_journal_get_create_access(handle, new_bh);
909 if (error) {
910 unlock_buffer(new_bh);
911 goto getblk_failed;
912 }
913 memcpy(new_bh->b_data, s->base, new_bh->b_size);
914 set_buffer_uptodate(new_bh);
915 unlock_buffer(new_bh);
916 ext4_xattr_cache_insert(new_bh);
917 error = ext4_handle_dirty_xattr_block(handle,
918 inode, new_bh);
919 if (error)
920 goto cleanup;
921 }
922 }
923
924 /* Update the inode. */
925 EXT4_I(inode)->i_file_acl = new_bh ? new_bh->b_blocknr : 0;
926
927 /* Drop the previous xattr block. */
928 if (bs->bh && bs->bh != new_bh)
929 ext4_xattr_release_block(handle, inode, bs->bh);
930 error = 0;
931
932cleanup:
933 if (ce)
934 mb_cache_entry_release(ce);
935 brelse(new_bh);
936 if (!(bs->bh && s->base == bs->bh->b_data))
937 kfree(s->base);
938
939 return error;
940
941cleanup_dquot:
942 dquot_free_block(inode, 1);
943 goto cleanup;
944
945bad_block:
946 EXT4_ERROR_INODE(inode, "bad block %llu",
947 EXT4_I(inode)->i_file_acl);
948 goto cleanup;
949
950#undef header
951}
952
953struct ext4_xattr_ibody_find {
954 struct ext4_xattr_search s;
955 struct ext4_iloc iloc;
956};
957
958static int
959ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i,
960 struct ext4_xattr_ibody_find *is)
961{
962 struct ext4_xattr_ibody_header *header;
963 struct ext4_inode *raw_inode;
964 int error;
965
966 if (EXT4_I(inode)->i_extra_isize == 0)
967 return 0;
968 raw_inode = ext4_raw_inode(&is->iloc);
969 header = IHDR(inode, raw_inode);
970 is->s.base = is->s.first = IFIRST(header);
971 is->s.here = is->s.first;
972 is->s.end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
973 if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
974 error = ext4_xattr_check_names(IFIRST(header), is->s.end);
975 if (error)
976 return error;
977 /* Find the named attribute. */
978 error = ext4_xattr_find_entry(&is->s.here, i->name_index,
979 i->name, is->s.end -
980 (void *)is->s.base, 0);
981 if (error && error != -ENODATA)
982 return error;
983 is->s.not_found = error;
984 }
985 return 0;
986}
987
988static int
989ext4_xattr_ibody_set(handle_t *handle, struct inode *inode,
990 struct ext4_xattr_info *i,
991 struct ext4_xattr_ibody_find *is)
992{
993 struct ext4_xattr_ibody_header *header;
994 struct ext4_xattr_search *s = &is->s;
995 int error;
996
997 if (EXT4_I(inode)->i_extra_isize == 0)
998 return -ENOSPC;
999 error = ext4_xattr_set_entry(i, s);
1000 if (error)
1001 return error;
1002 header = IHDR(inode, ext4_raw_inode(&is->iloc));
1003 if (!IS_LAST_ENTRY(s->first)) {
1004 header->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
1005 ext4_set_inode_state(inode, EXT4_STATE_XATTR);
1006 } else {
1007 header->h_magic = cpu_to_le32(0);
1008 ext4_clear_inode_state(inode, EXT4_STATE_XATTR);
1009 }
1010 return 0;
1011}
1012
1013/*
1014 * ext4_xattr_set_handle()
1015 *
1016 * Create, replace or remove an extended attribute for this inode. Value
1017 * is NULL to remove an existing extended attribute, and non-NULL to
1018 * either replace an existing extended attribute, or create a new extended
1019 * attribute. The flags XATTR_REPLACE and XATTR_CREATE
1020 * specify that an extended attribute must exist and must not exist
1021 * previous to the call, respectively.
1022 *
1023 * Returns 0, or a negative error number on failure.
1024 */
1025int
1026ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
1027 const char *name, const void *value, size_t value_len,
1028 int flags)
1029{
1030 struct ext4_xattr_info i = {
1031 .name_index = name_index,
1032 .name = name,
1033 .value = value,
1034 .value_len = value_len,
1035
1036 };
1037 struct ext4_xattr_ibody_find is = {
1038 .s = { .not_found = -ENODATA, },
1039 };
1040 struct ext4_xattr_block_find bs = {
1041 .s = { .not_found = -ENODATA, },
1042 };
1043 unsigned long no_expand;
1044 int error;
1045
1046 if (!name)
1047 return -EINVAL;
1048 if (strlen(name) > 255)
1049 return -ERANGE;
1050 down_write(&EXT4_I(inode)->xattr_sem);
1051 no_expand = ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND);
1052 ext4_set_inode_state(inode, EXT4_STATE_NO_EXPAND);
1053
1054 error = ext4_reserve_inode_write(handle, inode, &is.iloc);
1055 if (error)
1056 goto cleanup;
1057
1058 if (ext4_test_inode_state(inode, EXT4_STATE_NEW)) {
1059 struct ext4_inode *raw_inode = ext4_raw_inode(&is.iloc);
1060 memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size);
1061 ext4_clear_inode_state(inode, EXT4_STATE_NEW);
1062 }
1063
1064 error = ext4_xattr_ibody_find(inode, &i, &is);
1065 if (error)
1066 goto cleanup;
1067 if (is.s.not_found)
1068 error = ext4_xattr_block_find(inode, &i, &bs);
1069 if (error)
1070 goto cleanup;
1071 if (is.s.not_found && bs.s.not_found) {
1072 error = -ENODATA;
1073 if (flags & XATTR_REPLACE)
1074 goto cleanup;
1075 error = 0;
1076 if (!value)
1077 goto cleanup;
1078 } else {
1079 error = -EEXIST;
1080 if (flags & XATTR_CREATE)
1081 goto cleanup;
1082 }
1083 if (!value) {
1084 if (!is.s.not_found)
1085 error = ext4_xattr_ibody_set(handle, inode, &i, &is);
1086 else if (!bs.s.not_found)
1087 error = ext4_xattr_block_set(handle, inode, &i, &bs);
1088 } else {
1089 error = ext4_xattr_ibody_set(handle, inode, &i, &is);
1090 if (!error && !bs.s.not_found) {
1091 i.value = NULL;
1092 error = ext4_xattr_block_set(handle, inode, &i, &bs);
1093 } else if (error == -ENOSPC) {
1094 if (EXT4_I(inode)->i_file_acl && !bs.s.base) {
1095 error = ext4_xattr_block_find(inode, &i, &bs);
1096 if (error)
1097 goto cleanup;
1098 }
1099 error = ext4_xattr_block_set(handle, inode, &i, &bs);
1100 if (error)
1101 goto cleanup;
1102 if (!is.s.not_found) {
1103 i.value = NULL;
1104 error = ext4_xattr_ibody_set(handle, inode, &i,
1105 &is);
1106 }
1107 }
1108 }
1109 if (!error) {
1110 ext4_xattr_update_super_block(handle, inode->i_sb);
1111 inode->i_ctime = ext4_current_time(inode);
1112 if (!value)
1113 ext4_clear_inode_state(inode, EXT4_STATE_NO_EXPAND);
1114 error = ext4_mark_iloc_dirty(handle, inode, &is.iloc);
1115 /*
1116 * The bh is consumed by ext4_mark_iloc_dirty, even with
1117 * error != 0.
1118 */
1119 is.iloc.bh = NULL;
1120 if (IS_SYNC(inode))
1121 ext4_handle_sync(handle);
1122 }
1123
1124cleanup:
1125 brelse(is.iloc.bh);
1126 brelse(bs.bh);
1127 if (no_expand == 0)
1128 ext4_clear_inode_state(inode, EXT4_STATE_NO_EXPAND);
1129 up_write(&EXT4_I(inode)->xattr_sem);
1130 return error;
1131}
1132
1133/*
1134 * ext4_xattr_set()
1135 *
1136 * Like ext4_xattr_set_handle, but start from an inode. This extended
1137 * attribute modification is a filesystem transaction by itself.
1138 *
1139 * Returns 0, or a negative error number on failure.
1140 */
1141int
1142ext4_xattr_set(struct inode *inode, int name_index, const char *name,
1143 const void *value, size_t value_len, int flags)
1144{
1145 handle_t *handle;
1146 int error, retries = 0;
1147
1148retry:
1149 handle = ext4_journal_start(inode, EXT4_DATA_TRANS_BLOCKS(inode->i_sb));
1150 if (IS_ERR(handle)) {
1151 error = PTR_ERR(handle);
1152 } else {
1153 int error2;
1154
1155 error = ext4_xattr_set_handle(handle, inode, name_index, name,
1156 value, value_len, flags);
1157 error2 = ext4_journal_stop(handle);
1158 if (error == -ENOSPC &&
1159 ext4_should_retry_alloc(inode->i_sb, &retries))
1160 goto retry;
1161 if (error == 0)
1162 error = error2;
1163 }
1164
1165 return error;
1166}
1167
1168/*
1169 * Shift the EA entries in the inode to create space for the increased
1170 * i_extra_isize.
1171 */
1172static void ext4_xattr_shift_entries(struct ext4_xattr_entry *entry,
1173 int value_offs_shift, void *to,
1174 void *from, size_t n, int blocksize)
1175{
1176 struct ext4_xattr_entry *last = entry;
1177 int new_offs;
1178
1179 /* Adjust the value offsets of the entries */
1180 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
1181 if (!last->e_value_block && last->e_value_size) {
1182 new_offs = le16_to_cpu(last->e_value_offs) +
1183 value_offs_shift;
1184 BUG_ON(new_offs + le32_to_cpu(last->e_value_size)
1185 > blocksize);
1186 last->e_value_offs = cpu_to_le16(new_offs);
1187 }
1188 }
1189 /* Shift the entries by n bytes */
1190 memmove(to, from, n);
1191}
1192
1193/*
1194 * Expand an inode by new_extra_isize bytes when EAs are present.
1195 * Returns 0 on success or negative error number on failure.
1196 */
1197int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
1198 struct ext4_inode *raw_inode, handle_t *handle)
1199{
1200 struct ext4_xattr_ibody_header *header;
1201 struct ext4_xattr_entry *entry, *last, *first;
1202 struct buffer_head *bh = NULL;
1203 struct ext4_xattr_ibody_find *is = NULL;
1204 struct ext4_xattr_block_find *bs = NULL;
1205 char *buffer = NULL, *b_entry_name = NULL;
1206 size_t min_offs, free;
1207 int total_ino, total_blk;
1208 void *base, *start, *end;
1209 int extra_isize = 0, error = 0, tried_min_extra_isize = 0;
1210 int s_min_extra_isize = le16_to_cpu(EXT4_SB(inode->i_sb)->s_es->s_min_extra_isize);
1211
1212 down_write(&EXT4_I(inode)->xattr_sem);
1213retry:
1214 if (EXT4_I(inode)->i_extra_isize >= new_extra_isize) {
1215 up_write(&EXT4_I(inode)->xattr_sem);
1216 return 0;
1217 }
1218
1219 header = IHDR(inode, raw_inode);
1220 entry = IFIRST(header);
1221
1222 /*
1223 * Check if enough free space is available in the inode to shift the
1224 * entries ahead by new_extra_isize.
1225 */
1226
1227 base = start = entry;
1228 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
1229 min_offs = end - base;
1230 last = entry;
1231 total_ino = sizeof(struct ext4_xattr_ibody_header);
1232
1233 free = ext4_xattr_free_space(last, &min_offs, base, &total_ino);
1234 if (free >= new_extra_isize) {
1235 entry = IFIRST(header);
1236 ext4_xattr_shift_entries(entry, EXT4_I(inode)->i_extra_isize
1237 - new_extra_isize, (void *)raw_inode +
1238 EXT4_GOOD_OLD_INODE_SIZE + new_extra_isize,
1239 (void *)header, total_ino,
1240 inode->i_sb->s_blocksize);
1241 EXT4_I(inode)->i_extra_isize = new_extra_isize;
1242 error = 0;
1243 goto cleanup;
1244 }
1245
1246 /*
1247 * Enough free space isn't available in the inode, check if
1248 * EA block can hold new_extra_isize bytes.
1249 */
1250 if (EXT4_I(inode)->i_file_acl) {
1251 bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl);
1252 error = -EIO;
1253 if (!bh)
1254 goto cleanup;
1255 if (ext4_xattr_check_block(inode, bh)) {
1256 EXT4_ERROR_INODE(inode, "bad block %llu",
1257 EXT4_I(inode)->i_file_acl);
1258 error = -EIO;
1259 goto cleanup;
1260 }
1261 base = BHDR(bh);
1262 first = BFIRST(bh);
1263 end = bh->b_data + bh->b_size;
1264 min_offs = end - base;
1265 free = ext4_xattr_free_space(first, &min_offs, base,
1266 &total_blk);
1267 if (free < new_extra_isize) {
1268 if (!tried_min_extra_isize && s_min_extra_isize) {
1269 tried_min_extra_isize++;
1270 new_extra_isize = s_min_extra_isize;
1271 brelse(bh);
1272 goto retry;
1273 }
1274 error = -1;
1275 goto cleanup;
1276 }
1277 } else {
1278 free = inode->i_sb->s_blocksize;
1279 }
1280
1281 while (new_extra_isize > 0) {
1282 size_t offs, size, entry_size;
1283 struct ext4_xattr_entry *small_entry = NULL;
1284 struct ext4_xattr_info i = {
1285 .value = NULL,
1286 .value_len = 0,
1287 };
1288 unsigned int total_size; /* EA entry size + value size */
1289 unsigned int shift_bytes; /* No. of bytes to shift EAs by? */
1290 unsigned int min_total_size = ~0U;
1291
1292 is = kzalloc(sizeof(struct ext4_xattr_ibody_find), GFP_NOFS);
1293 bs = kzalloc(sizeof(struct ext4_xattr_block_find), GFP_NOFS);
1294 if (!is || !bs) {
1295 error = -ENOMEM;
1296 goto cleanup;
1297 }
1298
1299 is->s.not_found = -ENODATA;
1300 bs->s.not_found = -ENODATA;
1301 is->iloc.bh = NULL;
1302 bs->bh = NULL;
1303
1304 last = IFIRST(header);
1305 /* Find the entry best suited to be pushed into EA block */
1306 entry = NULL;
1307 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
1308 total_size =
1309 EXT4_XATTR_SIZE(le32_to_cpu(last->e_value_size)) +
1310 EXT4_XATTR_LEN(last->e_name_len);
1311 if (total_size <= free && total_size < min_total_size) {
1312 if (total_size < new_extra_isize) {
1313 small_entry = last;
1314 } else {
1315 entry = last;
1316 min_total_size = total_size;
1317 }
1318 }
1319 }
1320
1321 if (entry == NULL) {
1322 if (small_entry) {
1323 entry = small_entry;
1324 } else {
1325 if (!tried_min_extra_isize &&
1326 s_min_extra_isize) {
1327 tried_min_extra_isize++;
1328 new_extra_isize = s_min_extra_isize;
1329 goto retry;
1330 }
1331 error = -1;
1332 goto cleanup;
1333 }
1334 }
1335 offs = le16_to_cpu(entry->e_value_offs);
1336 size = le32_to_cpu(entry->e_value_size);
1337 entry_size = EXT4_XATTR_LEN(entry->e_name_len);
1338 i.name_index = entry->e_name_index,
1339 buffer = kmalloc(EXT4_XATTR_SIZE(size), GFP_NOFS);
1340 b_entry_name = kmalloc(entry->e_name_len + 1, GFP_NOFS);
1341 if (!buffer || !b_entry_name) {
1342 error = -ENOMEM;
1343 goto cleanup;
1344 }
1345 /* Save the entry name and the entry value */
1346 memcpy(buffer, (void *)IFIRST(header) + offs,
1347 EXT4_XATTR_SIZE(size));
1348 memcpy(b_entry_name, entry->e_name, entry->e_name_len);
1349 b_entry_name[entry->e_name_len] = '\0';
1350 i.name = b_entry_name;
1351
1352 error = ext4_get_inode_loc(inode, &is->iloc);
1353 if (error)
1354 goto cleanup;
1355
1356 error = ext4_xattr_ibody_find(inode, &i, is);
1357 if (error)
1358 goto cleanup;
1359
1360 /* Remove the chosen entry from the inode */
1361 error = ext4_xattr_ibody_set(handle, inode, &i, is);
1362 if (error)
1363 goto cleanup;
1364
1365 entry = IFIRST(header);
1366 if (entry_size + EXT4_XATTR_SIZE(size) >= new_extra_isize)
1367 shift_bytes = new_extra_isize;
1368 else
1369 shift_bytes = entry_size + size;
1370 /* Adjust the offsets and shift the remaining entries ahead */
1371 ext4_xattr_shift_entries(entry, EXT4_I(inode)->i_extra_isize -
1372 shift_bytes, (void *)raw_inode +
1373 EXT4_GOOD_OLD_INODE_SIZE + extra_isize + shift_bytes,
1374 (void *)header, total_ino - entry_size,
1375 inode->i_sb->s_blocksize);
1376
1377 extra_isize += shift_bytes;
1378 new_extra_isize -= shift_bytes;
1379 EXT4_I(inode)->i_extra_isize = extra_isize;
1380
1381 i.name = b_entry_name;
1382 i.value = buffer;
1383 i.value_len = size;
1384 error = ext4_xattr_block_find(inode, &i, bs);
1385 if (error)
1386 goto cleanup;
1387
1388 /* Add entry which was removed from the inode into the block */
1389 error = ext4_xattr_block_set(handle, inode, &i, bs);
1390 if (error)
1391 goto cleanup;
1392 kfree(b_entry_name);
1393 kfree(buffer);
1394 b_entry_name = NULL;
1395 buffer = NULL;
1396 brelse(is->iloc.bh);
1397 kfree(is);
1398 kfree(bs);
1399 }
1400 brelse(bh);
1401 up_write(&EXT4_I(inode)->xattr_sem);
1402 return 0;
1403
1404cleanup:
1405 kfree(b_entry_name);
1406 kfree(buffer);
1407 if (is)
1408 brelse(is->iloc.bh);
1409 kfree(is);
1410 kfree(bs);
1411 brelse(bh);
1412 up_write(&EXT4_I(inode)->xattr_sem);
1413 return error;
1414}
1415
1416
1417
1418/*
1419 * ext4_xattr_delete_inode()
1420 *
1421 * Free extended attribute resources associated with this inode. This
1422 * is called immediately before an inode is freed. We have exclusive
1423 * access to the inode.
1424 */
1425void
1426ext4_xattr_delete_inode(handle_t *handle, struct inode *inode)
1427{
1428 struct buffer_head *bh = NULL;
1429
1430 if (!EXT4_I(inode)->i_file_acl)
1431 goto cleanup;
1432 bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl);
1433 if (!bh) {
1434 EXT4_ERROR_INODE(inode, "block %llu read error",
1435 EXT4_I(inode)->i_file_acl);
1436 goto cleanup;
1437 }
1438 if (BHDR(bh)->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC) ||
1439 BHDR(bh)->h_blocks != cpu_to_le32(1)) {
1440 EXT4_ERROR_INODE(inode, "bad block %llu",
1441 EXT4_I(inode)->i_file_acl);
1442 goto cleanup;
1443 }
1444 ext4_xattr_release_block(handle, inode, bh);
1445 EXT4_I(inode)->i_file_acl = 0;
1446
1447cleanup:
1448 brelse(bh);
1449}
1450
1451/*
1452 * ext4_xattr_put_super()
1453 *
1454 * This is called when a file system is unmounted.
1455 */
1456void
1457ext4_xattr_put_super(struct super_block *sb)
1458{
1459 mb_cache_shrink(sb->s_bdev);
1460}
1461
1462/*
1463 * ext4_xattr_cache_insert()
1464 *
1465 * Create a new entry in the extended attribute cache, and insert
1466 * it unless such an entry is already in the cache.
1467 *
1468 * Returns 0, or a negative error number on failure.
1469 */
1470static void
1471ext4_xattr_cache_insert(struct buffer_head *bh)
1472{
1473 __u32 hash = le32_to_cpu(BHDR(bh)->h_hash);
1474 struct mb_cache_entry *ce;
1475 int error;
1476
1477 ce = mb_cache_entry_alloc(ext4_xattr_cache, GFP_NOFS);
1478 if (!ce) {
1479 ea_bdebug(bh, "out of memory");
1480 return;
1481 }
1482 error = mb_cache_entry_insert(ce, bh->b_bdev, bh->b_blocknr, hash);
1483 if (error) {
1484 mb_cache_entry_free(ce);
1485 if (error == -EBUSY) {
1486 ea_bdebug(bh, "already in cache");
1487 error = 0;
1488 }
1489 } else {
1490 ea_bdebug(bh, "inserting [%x]", (int)hash);
1491 mb_cache_entry_release(ce);
1492 }
1493}
1494
1495/*
1496 * ext4_xattr_cmp()
1497 *
1498 * Compare two extended attribute blocks for equality.
1499 *
1500 * Returns 0 if the blocks are equal, 1 if they differ, and
1501 * a negative error number on errors.
1502 */
1503static int
1504ext4_xattr_cmp(struct ext4_xattr_header *header1,
1505 struct ext4_xattr_header *header2)
1506{
1507 struct ext4_xattr_entry *entry1, *entry2;
1508
1509 entry1 = ENTRY(header1+1);
1510 entry2 = ENTRY(header2+1);
1511 while (!IS_LAST_ENTRY(entry1)) {
1512 if (IS_LAST_ENTRY(entry2))
1513 return 1;
1514 if (entry1->e_hash != entry2->e_hash ||
1515 entry1->e_name_index != entry2->e_name_index ||
1516 entry1->e_name_len != entry2->e_name_len ||
1517 entry1->e_value_size != entry2->e_value_size ||
1518 memcmp(entry1->e_name, entry2->e_name, entry1->e_name_len))
1519 return 1;
1520 if (entry1->e_value_block != 0 || entry2->e_value_block != 0)
1521 return -EIO;
1522 if (memcmp((char *)header1 + le16_to_cpu(entry1->e_value_offs),
1523 (char *)header2 + le16_to_cpu(entry2->e_value_offs),
1524 le32_to_cpu(entry1->e_value_size)))
1525 return 1;
1526
1527 entry1 = EXT4_XATTR_NEXT(entry1);
1528 entry2 = EXT4_XATTR_NEXT(entry2);
1529 }
1530 if (!IS_LAST_ENTRY(entry2))
1531 return 1;
1532 return 0;
1533}
1534
1535/*
1536 * ext4_xattr_cache_find()
1537 *
1538 * Find an identical extended attribute block.
1539 *
1540 * Returns a pointer to the block found, or NULL if such a block was
1541 * not found or an error occurred.
1542 */
1543static struct buffer_head *
1544ext4_xattr_cache_find(struct inode *inode, struct ext4_xattr_header *header,
1545 struct mb_cache_entry **pce)
1546{
1547 __u32 hash = le32_to_cpu(header->h_hash);
1548 struct mb_cache_entry *ce;
1549
1550 if (!header->h_hash)
1551 return NULL; /* never share */
1552 ea_idebug(inode, "looking for cached blocks [%x]", (int)hash);
1553again:
1554 ce = mb_cache_entry_find_first(ext4_xattr_cache, inode->i_sb->s_bdev,
1555 hash);
1556 while (ce) {
1557 struct buffer_head *bh;
1558
1559 if (IS_ERR(ce)) {
1560 if (PTR_ERR(ce) == -EAGAIN)
1561 goto again;
1562 break;
1563 }
1564 bh = sb_bread(inode->i_sb, ce->e_block);
1565 if (!bh) {
1566 EXT4_ERROR_INODE(inode, "block %lu read error",
1567 (unsigned long) ce->e_block);
1568 } else if (le32_to_cpu(BHDR(bh)->h_refcount) >=
1569 EXT4_XATTR_REFCOUNT_MAX) {
1570 ea_idebug(inode, "block %lu refcount %d>=%d",
1571 (unsigned long) ce->e_block,
1572 le32_to_cpu(BHDR(bh)->h_refcount),
1573 EXT4_XATTR_REFCOUNT_MAX);
1574 } else if (ext4_xattr_cmp(header, BHDR(bh)) == 0) {
1575 *pce = ce;
1576 return bh;
1577 }
1578 brelse(bh);
1579 ce = mb_cache_entry_find_next(ce, inode->i_sb->s_bdev, hash);
1580 }
1581 return NULL;
1582}
1583
1584#define NAME_HASH_SHIFT 5
1585#define VALUE_HASH_SHIFT 16
1586
1587/*
1588 * ext4_xattr_hash_entry()
1589 *
1590 * Compute the hash of an extended attribute.
1591 */
1592static inline void ext4_xattr_hash_entry(struct ext4_xattr_header *header,
1593 struct ext4_xattr_entry *entry)
1594{
1595 __u32 hash = 0;
1596 char *name = entry->e_name;
1597 int n;
1598
1599 for (n = 0; n < entry->e_name_len; n++) {
1600 hash = (hash << NAME_HASH_SHIFT) ^
1601 (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^
1602 *name++;
1603 }
1604
1605 if (entry->e_value_block == 0 && entry->e_value_size != 0) {
1606 __le32 *value = (__le32 *)((char *)header +
1607 le16_to_cpu(entry->e_value_offs));
1608 for (n = (le32_to_cpu(entry->e_value_size) +
1609 EXT4_XATTR_ROUND) >> EXT4_XATTR_PAD_BITS; n; n--) {
1610 hash = (hash << VALUE_HASH_SHIFT) ^
1611 (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^
1612 le32_to_cpu(*value++);
1613 }
1614 }
1615 entry->e_hash = cpu_to_le32(hash);
1616}
1617
1618#undef NAME_HASH_SHIFT
1619#undef VALUE_HASH_SHIFT
1620
1621#define BLOCK_HASH_SHIFT 16
1622
1623/*
1624 * ext4_xattr_rehash()
1625 *
1626 * Re-compute the extended attribute hash value after an entry has changed.
1627 */
1628static void ext4_xattr_rehash(struct ext4_xattr_header *header,
1629 struct ext4_xattr_entry *entry)
1630{
1631 struct ext4_xattr_entry *here;
1632 __u32 hash = 0;
1633
1634 ext4_xattr_hash_entry(header, entry);
1635 here = ENTRY(header+1);
1636 while (!IS_LAST_ENTRY(here)) {
1637 if (!here->e_hash) {
1638 /* Block is not shared if an entry's hash value == 0 */
1639 hash = 0;
1640 break;
1641 }
1642 hash = (hash << BLOCK_HASH_SHIFT) ^
1643 (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^
1644 le32_to_cpu(here->e_hash);
1645 here = EXT4_XATTR_NEXT(here);
1646 }
1647 header->h_hash = cpu_to_le32(hash);
1648}
1649
1650#undef BLOCK_HASH_SHIFT
1651
1652int __init
1653ext4_init_xattr(void)
1654{
1655 ext4_xattr_cache = mb_cache_create("ext4_xattr", 6);
1656 if (!ext4_xattr_cache)
1657 return -ENOMEM;
1658 return 0;
1659}
1660
1661void
1662ext4_exit_xattr(void)
1663{
1664 if (ext4_xattr_cache)
1665 mb_cache_destroy(ext4_xattr_cache);
1666 ext4_xattr_cache = NULL;
1667}
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] = &nop_posix_acl_access,
92 [EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT] = &nop_posix_acl_default,
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 * const ext4_xattr_handlers[] = {
102 &ext4_xattr_user_handler,
103 &ext4_xattr_trusted_handler,
104#ifdef CONFIG_EXT4_FS_SECURITY
105 &ext4_xattr_security_handler,
106#endif
107 &ext4_xattr_hurd_handler,
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 struct ext4_inode_info *ei = EXT4_I(ea_inode);
125
126 lockdep_set_subclass(&ea_inode->i_rwsem, 1);
127 (void) ei; /* shut up clang warning if !CONFIG_LOCKDEP */
128 lockdep_set_subclass(&ei->i_data_sem, I_DATA_SEM_EA);
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 char *ext4_xattr_prefix(int name_index,
177 struct dentry *dentry)
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
184 if (!xattr_handler_can_list(handler, dentry))
185 return NULL;
186
187 return xattr_prefix(handler);
188}
189
190static int
191check_xattrs(struct inode *inode, struct buffer_head *bh,
192 struct ext4_xattr_entry *entry, void *end, void *value_start,
193 const char *function, unsigned int line)
194{
195 struct ext4_xattr_entry *e = entry;
196 int err = -EFSCORRUPTED;
197 char *err_str;
198
199 if (bh) {
200 if (BHDR(bh)->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC) ||
201 BHDR(bh)->h_blocks != cpu_to_le32(1)) {
202 err_str = "invalid header";
203 goto errout;
204 }
205 if (buffer_verified(bh))
206 return 0;
207 if (!ext4_xattr_block_csum_verify(inode, bh)) {
208 err = -EFSBADCRC;
209 err_str = "invalid checksum";
210 goto errout;
211 }
212 } else {
213 struct ext4_xattr_ibody_header *header = value_start;
214
215 header -= 1;
216 if (end - (void *)header < sizeof(*header) + sizeof(u32)) {
217 err_str = "in-inode xattr block too small";
218 goto errout;
219 }
220 if (header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC)) {
221 err_str = "bad magic number in in-inode xattr";
222 goto errout;
223 }
224 }
225
226 /* Find the end of the names list */
227 while (!IS_LAST_ENTRY(e)) {
228 struct ext4_xattr_entry *next = EXT4_XATTR_NEXT(e);
229 if ((void *)next >= end) {
230 err_str = "e_name out of bounds";
231 goto errout;
232 }
233 if (strnlen(e->e_name, e->e_name_len) != e->e_name_len) {
234 err_str = "bad e_name length";
235 goto errout;
236 }
237 e = next;
238 }
239
240 /* Check the values */
241 while (!IS_LAST_ENTRY(entry)) {
242 u32 size = le32_to_cpu(entry->e_value_size);
243 unsigned long ea_ino = le32_to_cpu(entry->e_value_inum);
244
245 if (!ext4_has_feature_ea_inode(inode->i_sb) && ea_ino) {
246 err_str = "ea_inode specified without ea_inode feature enabled";
247 goto errout;
248 }
249 if (ea_ino && ((ea_ino == EXT4_ROOT_INO) ||
250 !ext4_valid_inum(inode->i_sb, ea_ino))) {
251 err_str = "invalid ea_ino";
252 goto errout;
253 }
254 if (size > EXT4_XATTR_SIZE_MAX) {
255 err_str = "e_value size too large";
256 goto errout;
257 }
258
259 if (size != 0 && entry->e_value_inum == 0) {
260 u16 offs = le16_to_cpu(entry->e_value_offs);
261 void *value;
262
263 /*
264 * The value cannot overlap the names, and the value
265 * with padding cannot extend beyond 'end'. Check both
266 * the padded and unpadded sizes, since the size may
267 * overflow to 0 when adding padding.
268 */
269 if (offs > end - value_start) {
270 err_str = "e_value out of bounds";
271 goto errout;
272 }
273 value = value_start + offs;
274 if (value < (void *)e + sizeof(u32) ||
275 size > end - value ||
276 EXT4_XATTR_SIZE(size) > end - value) {
277 err_str = "overlapping e_value ";
278 goto errout;
279 }
280 }
281 entry = EXT4_XATTR_NEXT(entry);
282 }
283 if (bh)
284 set_buffer_verified(bh);
285 return 0;
286
287errout:
288 if (bh)
289 __ext4_error_inode(inode, function, line, 0, -err,
290 "corrupted xattr block %llu: %s",
291 (unsigned long long) bh->b_blocknr,
292 err_str);
293 else
294 __ext4_error_inode(inode, function, line, 0, -err,
295 "corrupted in-inode xattr: %s", err_str);
296 return err;
297}
298
299static inline int
300__ext4_xattr_check_block(struct inode *inode, struct buffer_head *bh,
301 const char *function, unsigned int line)
302{
303 return check_xattrs(inode, bh, BFIRST(bh), bh->b_data + bh->b_size,
304 bh->b_data, function, line);
305}
306
307#define ext4_xattr_check_block(inode, bh) \
308 __ext4_xattr_check_block((inode), (bh), __func__, __LINE__)
309
310
311static inline int
312__xattr_check_inode(struct inode *inode, struct ext4_xattr_ibody_header *header,
313 void *end, const char *function, unsigned int line)
314{
315 return check_xattrs(inode, NULL, IFIRST(header), end, IFIRST(header),
316 function, line);
317}
318
319#define xattr_check_inode(inode, header, end) \
320 __xattr_check_inode((inode), (header), (end), __func__, __LINE__)
321
322static int
323xattr_find_entry(struct inode *inode, struct ext4_xattr_entry **pentry,
324 void *end, int name_index, const char *name, int sorted)
325{
326 struct ext4_xattr_entry *entry, *next;
327 size_t name_len;
328 int cmp = 1;
329
330 if (name == NULL)
331 return -EINVAL;
332 name_len = strlen(name);
333 for (entry = *pentry; !IS_LAST_ENTRY(entry); entry = next) {
334 next = EXT4_XATTR_NEXT(entry);
335 if ((void *) next >= end) {
336 EXT4_ERROR_INODE(inode, "corrupted xattr entries");
337 return -EFSCORRUPTED;
338 }
339 cmp = name_index - entry->e_name_index;
340 if (!cmp)
341 cmp = name_len - entry->e_name_len;
342 if (!cmp)
343 cmp = memcmp(name, entry->e_name, name_len);
344 if (cmp <= 0 && (sorted || cmp == 0))
345 break;
346 }
347 *pentry = entry;
348 return cmp ? -ENODATA : 0;
349}
350
351static u32
352ext4_xattr_inode_hash(struct ext4_sb_info *sbi, const void *buffer, size_t size)
353{
354 return ext4_chksum(sbi, sbi->s_csum_seed, buffer, size);
355}
356
357static u64 ext4_xattr_inode_get_ref(struct inode *ea_inode)
358{
359 return ((u64) inode_get_ctime_sec(ea_inode) << 32) |
360 (u32) inode_peek_iversion_raw(ea_inode);
361}
362
363static void ext4_xattr_inode_set_ref(struct inode *ea_inode, u64 ref_count)
364{
365 inode_set_ctime(ea_inode, (u32)(ref_count >> 32), 0);
366 inode_set_iversion_raw(ea_inode, ref_count & 0xffffffff);
367}
368
369static u32 ext4_xattr_inode_get_hash(struct inode *ea_inode)
370{
371 return (u32) inode_get_atime_sec(ea_inode);
372}
373
374static void ext4_xattr_inode_set_hash(struct inode *ea_inode, u32 hash)
375{
376 inode_set_atime(ea_inode, hash, 0);
377}
378
379/*
380 * Read the EA value from an inode.
381 */
382static int ext4_xattr_inode_read(struct inode *ea_inode, void *buf, size_t size)
383{
384 int blocksize = 1 << ea_inode->i_blkbits;
385 int bh_count = (size + blocksize - 1) >> ea_inode->i_blkbits;
386 int tail_size = (size % blocksize) ?: blocksize;
387 struct buffer_head *bhs_inline[8];
388 struct buffer_head **bhs = bhs_inline;
389 int i, ret;
390
391 if (bh_count > ARRAY_SIZE(bhs_inline)) {
392 bhs = kmalloc_array(bh_count, sizeof(*bhs), GFP_NOFS);
393 if (!bhs)
394 return -ENOMEM;
395 }
396
397 ret = ext4_bread_batch(ea_inode, 0 /* block */, bh_count,
398 true /* wait */, bhs);
399 if (ret)
400 goto free_bhs;
401
402 for (i = 0; i < bh_count; i++) {
403 /* There shouldn't be any holes in ea_inode. */
404 if (!bhs[i]) {
405 ret = -EFSCORRUPTED;
406 goto put_bhs;
407 }
408 memcpy((char *)buf + blocksize * i, bhs[i]->b_data,
409 i < bh_count - 1 ? blocksize : tail_size);
410 }
411 ret = 0;
412put_bhs:
413 for (i = 0; i < bh_count; i++)
414 brelse(bhs[i]);
415free_bhs:
416 if (bhs != bhs_inline)
417 kfree(bhs);
418 return ret;
419}
420
421#define EXT4_XATTR_INODE_GET_PARENT(inode) ((__u32)(inode_get_mtime_sec(inode)))
422
423static int ext4_xattr_inode_iget(struct inode *parent, unsigned long ea_ino,
424 u32 ea_inode_hash, struct inode **ea_inode)
425{
426 struct inode *inode;
427 int err;
428
429 /*
430 * We have to check for this corruption early as otherwise
431 * iget_locked() could wait indefinitely for the state of our
432 * parent inode.
433 */
434 if (parent->i_ino == ea_ino) {
435 ext4_error(parent->i_sb,
436 "Parent and EA inode have the same ino %lu", ea_ino);
437 return -EFSCORRUPTED;
438 }
439
440 inode = ext4_iget(parent->i_sb, ea_ino, EXT4_IGET_EA_INODE);
441 if (IS_ERR(inode)) {
442 err = PTR_ERR(inode);
443 ext4_error(parent->i_sb,
444 "error while reading EA inode %lu err=%d", ea_ino,
445 err);
446 return err;
447 }
448 ext4_xattr_inode_set_class(inode);
449
450 /*
451 * Check whether this is an old Lustre-style xattr inode. Lustre
452 * implementation does not have hash validation, rather it has a
453 * backpointer from ea_inode to the parent inode.
454 */
455 if (ea_inode_hash != ext4_xattr_inode_get_hash(inode) &&
456 EXT4_XATTR_INODE_GET_PARENT(inode) == parent->i_ino &&
457 inode->i_generation == parent->i_generation) {
458 ext4_set_inode_state(inode, EXT4_STATE_LUSTRE_EA_INODE);
459 ext4_xattr_inode_set_ref(inode, 1);
460 } else {
461 inode_lock(inode);
462 inode->i_flags |= S_NOQUOTA;
463 inode_unlock(inode);
464 }
465
466 *ea_inode = inode;
467 return 0;
468}
469
470/* Remove entry from mbcache when EA inode is getting evicted */
471void ext4_evict_ea_inode(struct inode *inode)
472{
473 struct mb_cache_entry *oe;
474
475 if (!EA_INODE_CACHE(inode))
476 return;
477 /* Wait for entry to get unused so that we can remove it */
478 while ((oe = mb_cache_entry_delete_or_get(EA_INODE_CACHE(inode),
479 ext4_xattr_inode_get_hash(inode), inode->i_ino))) {
480 mb_cache_entry_wait_unused(oe);
481 mb_cache_entry_put(EA_INODE_CACHE(inode), oe);
482 }
483}
484
485static int
486ext4_xattr_inode_verify_hashes(struct inode *ea_inode,
487 struct ext4_xattr_entry *entry, void *buffer,
488 size_t size)
489{
490 u32 hash;
491
492 /* Verify stored hash matches calculated hash. */
493 hash = ext4_xattr_inode_hash(EXT4_SB(ea_inode->i_sb), buffer, size);
494 if (hash != ext4_xattr_inode_get_hash(ea_inode))
495 return -EFSCORRUPTED;
496
497 if (entry) {
498 __le32 e_hash, tmp_data;
499
500 /* Verify entry hash. */
501 tmp_data = cpu_to_le32(hash);
502 e_hash = ext4_xattr_hash_entry(entry->e_name, entry->e_name_len,
503 &tmp_data, 1);
504 /* All good? */
505 if (e_hash == entry->e_hash)
506 return 0;
507
508 /*
509 * Not good. Maybe the entry hash was calculated
510 * using the buggy signed char version?
511 */
512 e_hash = ext4_xattr_hash_entry_signed(entry->e_name, entry->e_name_len,
513 &tmp_data, 1);
514 /* Still no match - bad */
515 if (e_hash != entry->e_hash)
516 return -EFSCORRUPTED;
517
518 /* Let people know about old hash */
519 pr_warn_once("ext4: filesystem with signed xattr name hash");
520 }
521 return 0;
522}
523
524/*
525 * Read xattr value from the EA inode.
526 */
527static int
528ext4_xattr_inode_get(struct inode *inode, struct ext4_xattr_entry *entry,
529 void *buffer, size_t size)
530{
531 struct mb_cache *ea_inode_cache = EA_INODE_CACHE(inode);
532 struct inode *ea_inode;
533 int err;
534
535 err = ext4_xattr_inode_iget(inode, le32_to_cpu(entry->e_value_inum),
536 le32_to_cpu(entry->e_hash), &ea_inode);
537 if (err) {
538 ea_inode = NULL;
539 goto out;
540 }
541
542 if (i_size_read(ea_inode) != size) {
543 ext4_warning_inode(ea_inode,
544 "ea_inode file size=%llu entry size=%zu",
545 i_size_read(ea_inode), size);
546 err = -EFSCORRUPTED;
547 goto out;
548 }
549
550 err = ext4_xattr_inode_read(ea_inode, buffer, size);
551 if (err)
552 goto out;
553
554 if (!ext4_test_inode_state(ea_inode, EXT4_STATE_LUSTRE_EA_INODE)) {
555 err = ext4_xattr_inode_verify_hashes(ea_inode, entry, buffer,
556 size);
557 if (err) {
558 ext4_warning_inode(ea_inode,
559 "EA inode hash validation failed");
560 goto out;
561 }
562
563 if (ea_inode_cache)
564 mb_cache_entry_create(ea_inode_cache, GFP_NOFS,
565 ext4_xattr_inode_get_hash(ea_inode),
566 ea_inode->i_ino, true /* reusable */);
567 }
568out:
569 iput(ea_inode);
570 return err;
571}
572
573static int
574ext4_xattr_block_get(struct inode *inode, int name_index, const char *name,
575 void *buffer, size_t buffer_size)
576{
577 struct buffer_head *bh = NULL;
578 struct ext4_xattr_entry *entry;
579 size_t size;
580 void *end;
581 int error;
582 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
583
584 ea_idebug(inode, "name=%d.%s, buffer=%p, buffer_size=%ld",
585 name_index, name, buffer, (long)buffer_size);
586
587 if (!EXT4_I(inode)->i_file_acl)
588 return -ENODATA;
589 ea_idebug(inode, "reading block %llu",
590 (unsigned long long)EXT4_I(inode)->i_file_acl);
591 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
592 if (IS_ERR(bh))
593 return PTR_ERR(bh);
594 ea_bdebug(bh, "b_count=%d, refcount=%d",
595 atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount));
596 error = ext4_xattr_check_block(inode, bh);
597 if (error)
598 goto cleanup;
599 ext4_xattr_block_cache_insert(ea_block_cache, bh);
600 entry = BFIRST(bh);
601 end = bh->b_data + bh->b_size;
602 error = xattr_find_entry(inode, &entry, end, name_index, name, 1);
603 if (error)
604 goto cleanup;
605 size = le32_to_cpu(entry->e_value_size);
606 error = -ERANGE;
607 if (unlikely(size > EXT4_XATTR_SIZE_MAX))
608 goto cleanup;
609 if (buffer) {
610 if (size > buffer_size)
611 goto cleanup;
612 if (entry->e_value_inum) {
613 error = ext4_xattr_inode_get(inode, entry, buffer,
614 size);
615 if (error)
616 goto cleanup;
617 } else {
618 u16 offset = le16_to_cpu(entry->e_value_offs);
619 void *p = bh->b_data + offset;
620
621 if (unlikely(p + size > end))
622 goto cleanup;
623 memcpy(buffer, p, size);
624 }
625 }
626 error = size;
627
628cleanup:
629 brelse(bh);
630 return error;
631}
632
633int
634ext4_xattr_ibody_get(struct inode *inode, int name_index, const char *name,
635 void *buffer, size_t buffer_size)
636{
637 struct ext4_xattr_ibody_header *header;
638 struct ext4_xattr_entry *entry;
639 struct ext4_inode *raw_inode;
640 struct ext4_iloc iloc;
641 size_t size;
642 void *end;
643 int error;
644
645 if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR))
646 return -ENODATA;
647 error = ext4_get_inode_loc(inode, &iloc);
648 if (error)
649 return error;
650 raw_inode = ext4_raw_inode(&iloc);
651 header = IHDR(inode, raw_inode);
652 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
653 error = xattr_check_inode(inode, header, end);
654 if (error)
655 goto cleanup;
656 entry = IFIRST(header);
657 error = xattr_find_entry(inode, &entry, end, name_index, name, 0);
658 if (error)
659 goto cleanup;
660 size = le32_to_cpu(entry->e_value_size);
661 error = -ERANGE;
662 if (unlikely(size > EXT4_XATTR_SIZE_MAX))
663 goto cleanup;
664 if (buffer) {
665 if (size > buffer_size)
666 goto cleanup;
667 if (entry->e_value_inum) {
668 error = ext4_xattr_inode_get(inode, entry, buffer,
669 size);
670 if (error)
671 goto cleanup;
672 } else {
673 u16 offset = le16_to_cpu(entry->e_value_offs);
674 void *p = (void *)IFIRST(header) + offset;
675
676 if (unlikely(p + size > end))
677 goto cleanup;
678 memcpy(buffer, p, size);
679 }
680 }
681 error = size;
682
683cleanup:
684 brelse(iloc.bh);
685 return error;
686}
687
688/*
689 * ext4_xattr_get()
690 *
691 * Copy an extended attribute into the buffer
692 * provided, or compute the buffer size required.
693 * Buffer is NULL to compute the size of the buffer required.
694 *
695 * Returns a negative error number on failure, or the number of bytes
696 * used / required on success.
697 */
698int
699ext4_xattr_get(struct inode *inode, int name_index, const char *name,
700 void *buffer, size_t buffer_size)
701{
702 int error;
703
704 if (unlikely(ext4_forced_shutdown(inode->i_sb)))
705 return -EIO;
706
707 if (strlen(name) > 255)
708 return -ERANGE;
709
710 down_read(&EXT4_I(inode)->xattr_sem);
711 error = ext4_xattr_ibody_get(inode, name_index, name, buffer,
712 buffer_size);
713 if (error == -ENODATA)
714 error = ext4_xattr_block_get(inode, name_index, name, buffer,
715 buffer_size);
716 up_read(&EXT4_I(inode)->xattr_sem);
717 return error;
718}
719
720static int
721ext4_xattr_list_entries(struct dentry *dentry, struct ext4_xattr_entry *entry,
722 char *buffer, size_t buffer_size)
723{
724 size_t rest = buffer_size;
725
726 for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) {
727 const char *prefix;
728
729 prefix = ext4_xattr_prefix(entry->e_name_index, dentry);
730 if (prefix) {
731 size_t prefix_len = strlen(prefix);
732 size_t size = prefix_len + entry->e_name_len + 1;
733
734 if (buffer) {
735 if (size > rest)
736 return -ERANGE;
737 memcpy(buffer, prefix, prefix_len);
738 buffer += prefix_len;
739 memcpy(buffer, entry->e_name, entry->e_name_len);
740 buffer += entry->e_name_len;
741 *buffer++ = 0;
742 }
743 rest -= size;
744 }
745 }
746 return buffer_size - rest; /* total size */
747}
748
749static int
750ext4_xattr_block_list(struct dentry *dentry, char *buffer, size_t buffer_size)
751{
752 struct inode *inode = d_inode(dentry);
753 struct buffer_head *bh = NULL;
754 int error;
755
756 ea_idebug(inode, "buffer=%p, buffer_size=%ld",
757 buffer, (long)buffer_size);
758
759 if (!EXT4_I(inode)->i_file_acl)
760 return 0;
761 ea_idebug(inode, "reading block %llu",
762 (unsigned long long)EXT4_I(inode)->i_file_acl);
763 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
764 if (IS_ERR(bh))
765 return PTR_ERR(bh);
766 ea_bdebug(bh, "b_count=%d, refcount=%d",
767 atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount));
768 error = ext4_xattr_check_block(inode, bh);
769 if (error)
770 goto cleanup;
771 ext4_xattr_block_cache_insert(EA_BLOCK_CACHE(inode), bh);
772 error = ext4_xattr_list_entries(dentry, BFIRST(bh), buffer,
773 buffer_size);
774cleanup:
775 brelse(bh);
776 return error;
777}
778
779static int
780ext4_xattr_ibody_list(struct dentry *dentry, char *buffer, size_t buffer_size)
781{
782 struct inode *inode = d_inode(dentry);
783 struct ext4_xattr_ibody_header *header;
784 struct ext4_inode *raw_inode;
785 struct ext4_iloc iloc;
786 void *end;
787 int error;
788
789 if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR))
790 return 0;
791 error = ext4_get_inode_loc(inode, &iloc);
792 if (error)
793 return error;
794 raw_inode = ext4_raw_inode(&iloc);
795 header = IHDR(inode, raw_inode);
796 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
797 error = xattr_check_inode(inode, header, end);
798 if (error)
799 goto cleanup;
800 error = ext4_xattr_list_entries(dentry, IFIRST(header),
801 buffer, buffer_size);
802
803cleanup:
804 brelse(iloc.bh);
805 return error;
806}
807
808/*
809 * Inode operation listxattr()
810 *
811 * d_inode(dentry)->i_rwsem: don't care
812 *
813 * Copy a list of attribute names into the buffer
814 * provided, or compute the buffer size required.
815 * Buffer is NULL to compute the size of the buffer required.
816 *
817 * Returns a negative error number on failure, or the number of bytes
818 * used / required on success.
819 */
820ssize_t
821ext4_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
822{
823 int ret, ret2;
824
825 down_read(&EXT4_I(d_inode(dentry))->xattr_sem);
826 ret = ret2 = ext4_xattr_ibody_list(dentry, buffer, buffer_size);
827 if (ret < 0)
828 goto errout;
829 if (buffer) {
830 buffer += ret;
831 buffer_size -= ret;
832 }
833 ret = ext4_xattr_block_list(dentry, buffer, buffer_size);
834 if (ret < 0)
835 goto errout;
836 ret += ret2;
837errout:
838 up_read(&EXT4_I(d_inode(dentry))->xattr_sem);
839 return ret;
840}
841
842/*
843 * If the EXT4_FEATURE_COMPAT_EXT_ATTR feature of this file system is
844 * not set, set it.
845 */
846static void ext4_xattr_update_super_block(handle_t *handle,
847 struct super_block *sb)
848{
849 if (ext4_has_feature_xattr(sb))
850 return;
851
852 BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access");
853 if (ext4_journal_get_write_access(handle, sb, EXT4_SB(sb)->s_sbh,
854 EXT4_JTR_NONE) == 0) {
855 lock_buffer(EXT4_SB(sb)->s_sbh);
856 ext4_set_feature_xattr(sb);
857 ext4_superblock_csum_set(sb);
858 unlock_buffer(EXT4_SB(sb)->s_sbh);
859 ext4_handle_dirty_metadata(handle, NULL, EXT4_SB(sb)->s_sbh);
860 }
861}
862
863int ext4_get_inode_usage(struct inode *inode, qsize_t *usage)
864{
865 struct ext4_iloc iloc = { .bh = NULL };
866 struct buffer_head *bh = NULL;
867 struct ext4_inode *raw_inode;
868 struct ext4_xattr_ibody_header *header;
869 struct ext4_xattr_entry *entry;
870 qsize_t ea_inode_refs = 0;
871 void *end;
872 int ret;
873
874 lockdep_assert_held_read(&EXT4_I(inode)->xattr_sem);
875
876 if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
877 ret = ext4_get_inode_loc(inode, &iloc);
878 if (ret)
879 goto out;
880 raw_inode = ext4_raw_inode(&iloc);
881 header = IHDR(inode, raw_inode);
882 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
883 ret = xattr_check_inode(inode, header, end);
884 if (ret)
885 goto out;
886
887 for (entry = IFIRST(header); !IS_LAST_ENTRY(entry);
888 entry = EXT4_XATTR_NEXT(entry))
889 if (entry->e_value_inum)
890 ea_inode_refs++;
891 }
892
893 if (EXT4_I(inode)->i_file_acl) {
894 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
895 if (IS_ERR(bh)) {
896 ret = PTR_ERR(bh);
897 bh = NULL;
898 goto out;
899 }
900
901 ret = ext4_xattr_check_block(inode, bh);
902 if (ret)
903 goto out;
904
905 for (entry = BFIRST(bh); !IS_LAST_ENTRY(entry);
906 entry = EXT4_XATTR_NEXT(entry))
907 if (entry->e_value_inum)
908 ea_inode_refs++;
909 }
910 *usage = ea_inode_refs + 1;
911 ret = 0;
912out:
913 brelse(iloc.bh);
914 brelse(bh);
915 return ret;
916}
917
918static inline size_t round_up_cluster(struct inode *inode, size_t length)
919{
920 struct super_block *sb = inode->i_sb;
921 size_t cluster_size = 1 << (EXT4_SB(sb)->s_cluster_bits +
922 inode->i_blkbits);
923 size_t mask = ~(cluster_size - 1);
924
925 return (length + cluster_size - 1) & mask;
926}
927
928static int ext4_xattr_inode_alloc_quota(struct inode *inode, size_t len)
929{
930 int err;
931
932 err = dquot_alloc_inode(inode);
933 if (err)
934 return err;
935 err = dquot_alloc_space_nodirty(inode, round_up_cluster(inode, len));
936 if (err)
937 dquot_free_inode(inode);
938 return err;
939}
940
941static void ext4_xattr_inode_free_quota(struct inode *parent,
942 struct inode *ea_inode,
943 size_t len)
944{
945 if (ea_inode &&
946 ext4_test_inode_state(ea_inode, EXT4_STATE_LUSTRE_EA_INODE))
947 return;
948 dquot_free_space_nodirty(parent, round_up_cluster(parent, len));
949 dquot_free_inode(parent);
950}
951
952int __ext4_xattr_set_credits(struct super_block *sb, struct inode *inode,
953 struct buffer_head *block_bh, size_t value_len,
954 bool is_create)
955{
956 int credits;
957 int blocks;
958
959 /*
960 * 1) Owner inode update
961 * 2) Ref count update on old xattr block
962 * 3) new xattr block
963 * 4) block bitmap update for new xattr block
964 * 5) group descriptor for new xattr block
965 * 6) block bitmap update for old xattr block
966 * 7) group descriptor for old block
967 *
968 * 6 & 7 can happen if we have two racing threads T_a and T_b
969 * which are each trying to set an xattr on inodes I_a and I_b
970 * which were both initially sharing an xattr block.
971 */
972 credits = 7;
973
974 /* Quota updates. */
975 credits += EXT4_MAXQUOTAS_TRANS_BLOCKS(sb);
976
977 /*
978 * In case of inline data, we may push out the data to a block,
979 * so we need to reserve credits for this eventuality
980 */
981 if (inode && ext4_has_inline_data(inode))
982 credits += ext4_writepage_trans_blocks(inode) + 1;
983
984 /* We are done if ea_inode feature is not enabled. */
985 if (!ext4_has_feature_ea_inode(sb))
986 return credits;
987
988 /* New ea_inode, inode map, block bitmap, group descriptor. */
989 credits += 4;
990
991 /* Data blocks. */
992 blocks = (value_len + sb->s_blocksize - 1) >> sb->s_blocksize_bits;
993
994 /* Indirection block or one level of extent tree. */
995 blocks += 1;
996
997 /* Block bitmap and group descriptor updates for each block. */
998 credits += blocks * 2;
999
1000 /* Blocks themselves. */
1001 credits += blocks;
1002
1003 if (!is_create) {
1004 /* Dereference ea_inode holding old xattr value.
1005 * Old ea_inode, inode map, block bitmap, group descriptor.
1006 */
1007 credits += 4;
1008
1009 /* Data blocks for old ea_inode. */
1010 blocks = XATTR_SIZE_MAX >> sb->s_blocksize_bits;
1011
1012 /* Indirection block or one level of extent tree for old
1013 * ea_inode.
1014 */
1015 blocks += 1;
1016
1017 /* Block bitmap and group descriptor updates for each block. */
1018 credits += blocks * 2;
1019 }
1020
1021 /* We may need to clone the existing xattr block in which case we need
1022 * to increment ref counts for existing ea_inodes referenced by it.
1023 */
1024 if (block_bh) {
1025 struct ext4_xattr_entry *entry = BFIRST(block_bh);
1026
1027 for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry))
1028 if (entry->e_value_inum)
1029 /* Ref count update on ea_inode. */
1030 credits += 1;
1031 }
1032 return credits;
1033}
1034
1035static int ext4_xattr_inode_update_ref(handle_t *handle, struct inode *ea_inode,
1036 int ref_change)
1037{
1038 struct ext4_iloc iloc;
1039 s64 ref_count;
1040 int ret;
1041
1042 inode_lock(ea_inode);
1043
1044 ret = ext4_reserve_inode_write(handle, ea_inode, &iloc);
1045 if (ret)
1046 goto out;
1047
1048 ref_count = ext4_xattr_inode_get_ref(ea_inode);
1049 ref_count += ref_change;
1050 ext4_xattr_inode_set_ref(ea_inode, ref_count);
1051
1052 if (ref_change > 0) {
1053 WARN_ONCE(ref_count <= 0, "EA inode %lu ref_count=%lld",
1054 ea_inode->i_ino, ref_count);
1055
1056 if (ref_count == 1) {
1057 WARN_ONCE(ea_inode->i_nlink, "EA inode %lu i_nlink=%u",
1058 ea_inode->i_ino, ea_inode->i_nlink);
1059
1060 set_nlink(ea_inode, 1);
1061 ext4_orphan_del(handle, ea_inode);
1062 }
1063 } else {
1064 WARN_ONCE(ref_count < 0, "EA inode %lu ref_count=%lld",
1065 ea_inode->i_ino, ref_count);
1066
1067 if (ref_count == 0) {
1068 WARN_ONCE(ea_inode->i_nlink != 1,
1069 "EA inode %lu i_nlink=%u",
1070 ea_inode->i_ino, ea_inode->i_nlink);
1071
1072 clear_nlink(ea_inode);
1073 ext4_orphan_add(handle, ea_inode);
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 int ext4_xattr_restart_fn(handle_t *handle, struct inode *inode,
1153 struct buffer_head *bh, bool block_csum, bool dirty)
1154{
1155 int error;
1156
1157 if (bh && dirty) {
1158 if (block_csum)
1159 ext4_xattr_block_csum_set(inode, bh);
1160 error = ext4_handle_dirty_metadata(handle, NULL, bh);
1161 if (error) {
1162 ext4_warning(inode->i_sb, "Handle metadata (error %d)",
1163 error);
1164 return error;
1165 }
1166 }
1167 return 0;
1168}
1169
1170static void
1171ext4_xattr_inode_dec_ref_all(handle_t *handle, struct inode *parent,
1172 struct buffer_head *bh,
1173 struct ext4_xattr_entry *first, bool block_csum,
1174 struct ext4_xattr_inode_array **ea_inode_array,
1175 int extra_credits, bool skip_quota)
1176{
1177 struct inode *ea_inode;
1178 struct ext4_xattr_entry *entry;
1179 bool dirty = false;
1180 unsigned int ea_ino;
1181 int err;
1182 int credits;
1183
1184 /* One credit for dec ref on ea_inode, one for orphan list addition, */
1185 credits = 2 + extra_credits;
1186
1187 for (entry = first; !IS_LAST_ENTRY(entry);
1188 entry = EXT4_XATTR_NEXT(entry)) {
1189 if (!entry->e_value_inum)
1190 continue;
1191 ea_ino = le32_to_cpu(entry->e_value_inum);
1192 err = ext4_xattr_inode_iget(parent, ea_ino,
1193 le32_to_cpu(entry->e_hash),
1194 &ea_inode);
1195 if (err)
1196 continue;
1197
1198 err = ext4_expand_inode_array(ea_inode_array, ea_inode);
1199 if (err) {
1200 ext4_warning_inode(ea_inode,
1201 "Expand inode array err=%d", err);
1202 iput(ea_inode);
1203 continue;
1204 }
1205
1206 err = ext4_journal_ensure_credits_fn(handle, credits, credits,
1207 ext4_free_metadata_revoke_credits(parent->i_sb, 1),
1208 ext4_xattr_restart_fn(handle, parent, bh, block_csum,
1209 dirty));
1210 if (err < 0) {
1211 ext4_warning_inode(ea_inode, "Ensure credits err=%d",
1212 err);
1213 continue;
1214 }
1215 if (err > 0) {
1216 err = ext4_journal_get_write_access(handle,
1217 parent->i_sb, bh, EXT4_JTR_NONE);
1218 if (err) {
1219 ext4_warning_inode(ea_inode,
1220 "Re-get write access err=%d",
1221 err);
1222 continue;
1223 }
1224 }
1225
1226 err = ext4_xattr_inode_dec_ref(handle, ea_inode);
1227 if (err) {
1228 ext4_warning_inode(ea_inode, "ea_inode dec ref err=%d",
1229 err);
1230 continue;
1231 }
1232
1233 if (!skip_quota)
1234 ext4_xattr_inode_free_quota(parent, ea_inode,
1235 le32_to_cpu(entry->e_value_size));
1236
1237 /*
1238 * Forget about ea_inode within the same transaction that
1239 * decrements the ref count. This avoids duplicate decrements in
1240 * case the rest of the work spills over to subsequent
1241 * transactions.
1242 */
1243 entry->e_value_inum = 0;
1244 entry->e_value_size = 0;
1245
1246 dirty = true;
1247 }
1248
1249 if (dirty) {
1250 /*
1251 * Note that we are deliberately skipping csum calculation for
1252 * the final update because we do not expect any journal
1253 * restarts until xattr block is freed.
1254 */
1255
1256 err = ext4_handle_dirty_metadata(handle, NULL, bh);
1257 if (err)
1258 ext4_warning_inode(parent,
1259 "handle dirty metadata err=%d", err);
1260 }
1261}
1262
1263/*
1264 * Release the xattr block BH: If the reference count is > 1, decrement it;
1265 * otherwise free the block.
1266 */
1267static void
1268ext4_xattr_release_block(handle_t *handle, struct inode *inode,
1269 struct buffer_head *bh,
1270 struct ext4_xattr_inode_array **ea_inode_array,
1271 int extra_credits)
1272{
1273 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
1274 u32 hash, ref;
1275 int error = 0;
1276
1277 BUFFER_TRACE(bh, "get_write_access");
1278 error = ext4_journal_get_write_access(handle, inode->i_sb, bh,
1279 EXT4_JTR_NONE);
1280 if (error)
1281 goto out;
1282
1283retry_ref:
1284 lock_buffer(bh);
1285 hash = le32_to_cpu(BHDR(bh)->h_hash);
1286 ref = le32_to_cpu(BHDR(bh)->h_refcount);
1287 if (ref == 1) {
1288 ea_bdebug(bh, "refcount now=0; freeing");
1289 /*
1290 * This must happen under buffer lock for
1291 * ext4_xattr_block_set() to reliably detect freed block
1292 */
1293 if (ea_block_cache) {
1294 struct mb_cache_entry *oe;
1295
1296 oe = mb_cache_entry_delete_or_get(ea_block_cache, hash,
1297 bh->b_blocknr);
1298 if (oe) {
1299 unlock_buffer(bh);
1300 mb_cache_entry_wait_unused(oe);
1301 mb_cache_entry_put(ea_block_cache, oe);
1302 goto retry_ref;
1303 }
1304 }
1305 get_bh(bh);
1306 unlock_buffer(bh);
1307
1308 if (ext4_has_feature_ea_inode(inode->i_sb))
1309 ext4_xattr_inode_dec_ref_all(handle, inode, bh,
1310 BFIRST(bh),
1311 true /* block_csum */,
1312 ea_inode_array,
1313 extra_credits,
1314 true /* skip_quota */);
1315 ext4_free_blocks(handle, inode, bh, 0, 1,
1316 EXT4_FREE_BLOCKS_METADATA |
1317 EXT4_FREE_BLOCKS_FORGET);
1318 } else {
1319 ref--;
1320 BHDR(bh)->h_refcount = cpu_to_le32(ref);
1321 if (ref == EXT4_XATTR_REFCOUNT_MAX - 1) {
1322 struct mb_cache_entry *ce;
1323
1324 if (ea_block_cache) {
1325 ce = mb_cache_entry_get(ea_block_cache, hash,
1326 bh->b_blocknr);
1327 if (ce) {
1328 set_bit(MBE_REUSABLE_B, &ce->e_flags);
1329 mb_cache_entry_put(ea_block_cache, ce);
1330 }
1331 }
1332 }
1333
1334 ext4_xattr_block_csum_set(inode, bh);
1335 /*
1336 * Beware of this ugliness: Releasing of xattr block references
1337 * from different inodes can race and so we have to protect
1338 * from a race where someone else frees the block (and releases
1339 * its journal_head) before we are done dirtying the buffer. In
1340 * nojournal mode this race is harmless and we actually cannot
1341 * call ext4_handle_dirty_metadata() with locked buffer as
1342 * that function can call sync_dirty_buffer() so for that case
1343 * we handle the dirtying after unlocking the buffer.
1344 */
1345 if (ext4_handle_valid(handle))
1346 error = ext4_handle_dirty_metadata(handle, inode, bh);
1347 unlock_buffer(bh);
1348 if (!ext4_handle_valid(handle))
1349 error = ext4_handle_dirty_metadata(handle, inode, bh);
1350 if (IS_SYNC(inode))
1351 ext4_handle_sync(handle);
1352 dquot_free_block(inode, EXT4_C2B(EXT4_SB(inode->i_sb), 1));
1353 ea_bdebug(bh, "refcount now=%d; releasing",
1354 le32_to_cpu(BHDR(bh)->h_refcount));
1355 }
1356out:
1357 ext4_std_error(inode->i_sb, error);
1358 return;
1359}
1360
1361/*
1362 * Find the available free space for EAs. This also returns the total number of
1363 * bytes used by EA entries.
1364 */
1365static size_t ext4_xattr_free_space(struct ext4_xattr_entry *last,
1366 size_t *min_offs, void *base, int *total)
1367{
1368 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
1369 if (!last->e_value_inum && last->e_value_size) {
1370 size_t offs = le16_to_cpu(last->e_value_offs);
1371 if (offs < *min_offs)
1372 *min_offs = offs;
1373 }
1374 if (total)
1375 *total += EXT4_XATTR_LEN(last->e_name_len);
1376 }
1377 return (*min_offs - ((void *)last - base) - sizeof(__u32));
1378}
1379
1380/*
1381 * Write the value of the EA in an inode.
1382 */
1383static int ext4_xattr_inode_write(handle_t *handle, struct inode *ea_inode,
1384 const void *buf, int bufsize)
1385{
1386 struct buffer_head *bh = NULL;
1387 unsigned long block = 0;
1388 int blocksize = ea_inode->i_sb->s_blocksize;
1389 int max_blocks = (bufsize + blocksize - 1) >> ea_inode->i_blkbits;
1390 int csize, wsize = 0;
1391 int ret = 0, ret2 = 0;
1392 int retries = 0;
1393
1394retry:
1395 while (ret >= 0 && ret < max_blocks) {
1396 struct ext4_map_blocks map;
1397 map.m_lblk = block += ret;
1398 map.m_len = max_blocks -= ret;
1399
1400 ret = ext4_map_blocks(handle, ea_inode, &map,
1401 EXT4_GET_BLOCKS_CREATE);
1402 if (ret <= 0) {
1403 ext4_mark_inode_dirty(handle, ea_inode);
1404 if (ret == -ENOSPC &&
1405 ext4_should_retry_alloc(ea_inode->i_sb, &retries)) {
1406 ret = 0;
1407 goto retry;
1408 }
1409 break;
1410 }
1411 }
1412
1413 if (ret < 0)
1414 return ret;
1415
1416 block = 0;
1417 while (wsize < bufsize) {
1418 brelse(bh);
1419 csize = (bufsize - wsize) > blocksize ? blocksize :
1420 bufsize - wsize;
1421 bh = ext4_getblk(handle, ea_inode, block, 0);
1422 if (IS_ERR(bh))
1423 return PTR_ERR(bh);
1424 if (!bh) {
1425 WARN_ON_ONCE(1);
1426 EXT4_ERROR_INODE(ea_inode,
1427 "ext4_getblk() return bh = NULL");
1428 return -EFSCORRUPTED;
1429 }
1430 ret = ext4_journal_get_write_access(handle, ea_inode->i_sb, bh,
1431 EXT4_JTR_NONE);
1432 if (ret)
1433 goto out;
1434
1435 memcpy(bh->b_data, buf, csize);
1436 set_buffer_uptodate(bh);
1437 ext4_handle_dirty_metadata(handle, ea_inode, bh);
1438
1439 buf += csize;
1440 wsize += csize;
1441 block += 1;
1442 }
1443
1444 inode_lock(ea_inode);
1445 i_size_write(ea_inode, wsize);
1446 ext4_update_i_disksize(ea_inode, wsize);
1447 inode_unlock(ea_inode);
1448
1449 ret2 = ext4_mark_inode_dirty(handle, ea_inode);
1450 if (unlikely(ret2 && !ret))
1451 ret = ret2;
1452
1453out:
1454 brelse(bh);
1455
1456 return ret;
1457}
1458
1459/*
1460 * Create an inode to store the value of a large EA.
1461 */
1462static struct inode *ext4_xattr_inode_create(handle_t *handle,
1463 struct inode *inode, u32 hash)
1464{
1465 struct inode *ea_inode = NULL;
1466 uid_t owner[2] = { i_uid_read(inode), i_gid_read(inode) };
1467 int err;
1468
1469 if (inode->i_sb->s_root == NULL) {
1470 ext4_warning(inode->i_sb,
1471 "refuse to create EA inode when umounting");
1472 WARN_ON(1);
1473 return ERR_PTR(-EINVAL);
1474 }
1475
1476 /*
1477 * Let the next inode be the goal, so we try and allocate the EA inode
1478 * in the same group, or nearby one.
1479 */
1480 ea_inode = ext4_new_inode(handle, inode->i_sb->s_root->d_inode,
1481 S_IFREG | 0600, NULL, inode->i_ino + 1, owner,
1482 EXT4_EA_INODE_FL);
1483 if (!IS_ERR(ea_inode)) {
1484 ea_inode->i_op = &ext4_file_inode_operations;
1485 ea_inode->i_fop = &ext4_file_operations;
1486 ext4_set_aops(ea_inode);
1487 ext4_xattr_inode_set_class(ea_inode);
1488 unlock_new_inode(ea_inode);
1489 ext4_xattr_inode_set_ref(ea_inode, 1);
1490 ext4_xattr_inode_set_hash(ea_inode, hash);
1491 err = ext4_mark_inode_dirty(handle, ea_inode);
1492 if (!err)
1493 err = ext4_inode_attach_jinode(ea_inode);
1494 if (err) {
1495 if (ext4_xattr_inode_dec_ref(handle, ea_inode))
1496 ext4_warning_inode(ea_inode,
1497 "cleanup dec ref error %d", err);
1498 iput(ea_inode);
1499 return ERR_PTR(err);
1500 }
1501
1502 /*
1503 * Xattr inodes are shared therefore quota charging is performed
1504 * at a higher level.
1505 */
1506 dquot_free_inode(ea_inode);
1507 dquot_drop(ea_inode);
1508 inode_lock(ea_inode);
1509 ea_inode->i_flags |= S_NOQUOTA;
1510 inode_unlock(ea_inode);
1511 }
1512
1513 return ea_inode;
1514}
1515
1516static struct inode *
1517ext4_xattr_inode_cache_find(struct inode *inode, const void *value,
1518 size_t value_len, u32 hash)
1519{
1520 struct inode *ea_inode;
1521 struct mb_cache_entry *ce;
1522 struct mb_cache *ea_inode_cache = EA_INODE_CACHE(inode);
1523 void *ea_data;
1524
1525 if (!ea_inode_cache)
1526 return NULL;
1527
1528 ce = mb_cache_entry_find_first(ea_inode_cache, hash);
1529 if (!ce)
1530 return NULL;
1531
1532 WARN_ON_ONCE(ext4_handle_valid(journal_current_handle()) &&
1533 !(current->flags & PF_MEMALLOC_NOFS));
1534
1535 ea_data = kvmalloc(value_len, GFP_KERNEL);
1536 if (!ea_data) {
1537 mb_cache_entry_put(ea_inode_cache, ce);
1538 return NULL;
1539 }
1540
1541 while (ce) {
1542 ea_inode = ext4_iget(inode->i_sb, ce->e_value,
1543 EXT4_IGET_EA_INODE);
1544 if (IS_ERR(ea_inode))
1545 goto next_entry;
1546 ext4_xattr_inode_set_class(ea_inode);
1547 if (i_size_read(ea_inode) == value_len &&
1548 !ext4_xattr_inode_read(ea_inode, ea_data, value_len) &&
1549 !ext4_xattr_inode_verify_hashes(ea_inode, NULL, ea_data,
1550 value_len) &&
1551 !memcmp(value, ea_data, value_len)) {
1552 mb_cache_entry_touch(ea_inode_cache, ce);
1553 mb_cache_entry_put(ea_inode_cache, ce);
1554 kvfree(ea_data);
1555 return ea_inode;
1556 }
1557 iput(ea_inode);
1558 next_entry:
1559 ce = mb_cache_entry_find_next(ea_inode_cache, ce);
1560 }
1561 kvfree(ea_data);
1562 return NULL;
1563}
1564
1565/*
1566 * Add value of the EA in an inode.
1567 */
1568static struct inode *ext4_xattr_inode_lookup_create(handle_t *handle,
1569 struct inode *inode, const void *value, size_t value_len)
1570{
1571 struct inode *ea_inode;
1572 u32 hash;
1573 int err;
1574
1575 /* Account inode & space to quota even if sharing... */
1576 err = ext4_xattr_inode_alloc_quota(inode, value_len);
1577 if (err)
1578 return ERR_PTR(err);
1579
1580 hash = ext4_xattr_inode_hash(EXT4_SB(inode->i_sb), value, value_len);
1581 ea_inode = ext4_xattr_inode_cache_find(inode, value, value_len, hash);
1582 if (ea_inode) {
1583 err = ext4_xattr_inode_inc_ref(handle, ea_inode);
1584 if (err)
1585 goto out_err;
1586 return ea_inode;
1587 }
1588
1589 /* Create an inode for the EA value */
1590 ea_inode = ext4_xattr_inode_create(handle, inode, hash);
1591 if (IS_ERR(ea_inode)) {
1592 ext4_xattr_inode_free_quota(inode, NULL, value_len);
1593 return ea_inode;
1594 }
1595
1596 err = ext4_xattr_inode_write(handle, ea_inode, value, value_len);
1597 if (err) {
1598 if (ext4_xattr_inode_dec_ref(handle, ea_inode))
1599 ext4_warning_inode(ea_inode, "cleanup dec ref error %d", err);
1600 goto out_err;
1601 }
1602
1603 if (EA_INODE_CACHE(inode))
1604 mb_cache_entry_create(EA_INODE_CACHE(inode), GFP_NOFS, hash,
1605 ea_inode->i_ino, true /* reusable */);
1606 return ea_inode;
1607out_err:
1608 iput(ea_inode);
1609 ext4_xattr_inode_free_quota(inode, NULL, value_len);
1610 return ERR_PTR(err);
1611}
1612
1613/*
1614 * Reserve min(block_size/8, 1024) bytes for xattr entries/names if ea_inode
1615 * feature is enabled.
1616 */
1617#define EXT4_XATTR_BLOCK_RESERVE(inode) min(i_blocksize(inode)/8, 1024U)
1618
1619static int ext4_xattr_set_entry(struct ext4_xattr_info *i,
1620 struct ext4_xattr_search *s,
1621 handle_t *handle, struct inode *inode,
1622 bool is_block)
1623{
1624 struct ext4_xattr_entry *last, *next;
1625 struct ext4_xattr_entry *here = s->here;
1626 size_t min_offs = s->end - s->base, name_len = strlen(i->name);
1627 int in_inode = i->in_inode;
1628 struct inode *old_ea_inode = NULL;
1629 struct inode *new_ea_inode = NULL;
1630 size_t old_size, new_size;
1631 int ret;
1632
1633 /* Space used by old and new values. */
1634 old_size = (!s->not_found && !here->e_value_inum) ?
1635 EXT4_XATTR_SIZE(le32_to_cpu(here->e_value_size)) : 0;
1636 new_size = (i->value && !in_inode) ? EXT4_XATTR_SIZE(i->value_len) : 0;
1637
1638 /*
1639 * Optimization for the simple case when old and new values have the
1640 * same padded sizes. Not applicable if external inodes are involved.
1641 */
1642 if (new_size && new_size == old_size) {
1643 size_t offs = le16_to_cpu(here->e_value_offs);
1644 void *val = s->base + offs;
1645
1646 here->e_value_size = cpu_to_le32(i->value_len);
1647 if (i->value == EXT4_ZERO_XATTR_VALUE) {
1648 memset(val, 0, new_size);
1649 } else {
1650 memcpy(val, i->value, i->value_len);
1651 /* Clear padding bytes. */
1652 memset(val + i->value_len, 0, new_size - i->value_len);
1653 }
1654 goto update_hash;
1655 }
1656
1657 /* Compute min_offs and last. */
1658 last = s->first;
1659 for (; !IS_LAST_ENTRY(last); last = next) {
1660 next = EXT4_XATTR_NEXT(last);
1661 if ((void *)next >= s->end) {
1662 EXT4_ERROR_INODE(inode, "corrupted xattr entries");
1663 ret = -EFSCORRUPTED;
1664 goto out;
1665 }
1666 if (!last->e_value_inum && last->e_value_size) {
1667 size_t offs = le16_to_cpu(last->e_value_offs);
1668 if (offs < min_offs)
1669 min_offs = offs;
1670 }
1671 }
1672
1673 /* Check whether we have enough space. */
1674 if (i->value) {
1675 size_t free;
1676
1677 free = min_offs - ((void *)last - s->base) - sizeof(__u32);
1678 if (!s->not_found)
1679 free += EXT4_XATTR_LEN(name_len) + old_size;
1680
1681 if (free < EXT4_XATTR_LEN(name_len) + new_size) {
1682 ret = -ENOSPC;
1683 goto out;
1684 }
1685
1686 /*
1687 * If storing the value in an external inode is an option,
1688 * reserve space for xattr entries/names in the external
1689 * attribute block so that a long value does not occupy the
1690 * whole space and prevent further entries being added.
1691 */
1692 if (ext4_has_feature_ea_inode(inode->i_sb) &&
1693 new_size && is_block &&
1694 (min_offs + old_size - new_size) <
1695 EXT4_XATTR_BLOCK_RESERVE(inode)) {
1696 ret = -ENOSPC;
1697 goto out;
1698 }
1699 }
1700
1701 /*
1702 * Getting access to old and new ea inodes is subject to failures.
1703 * Finish that work before doing any modifications to the xattr data.
1704 */
1705 if (!s->not_found && here->e_value_inum) {
1706 ret = ext4_xattr_inode_iget(inode,
1707 le32_to_cpu(here->e_value_inum),
1708 le32_to_cpu(here->e_hash),
1709 &old_ea_inode);
1710 if (ret) {
1711 old_ea_inode = NULL;
1712 goto out;
1713 }
1714 }
1715 if (i->value && in_inode) {
1716 WARN_ON_ONCE(!i->value_len);
1717
1718 new_ea_inode = ext4_xattr_inode_lookup_create(handle, inode,
1719 i->value, i->value_len);
1720 if (IS_ERR(new_ea_inode)) {
1721 ret = PTR_ERR(new_ea_inode);
1722 new_ea_inode = NULL;
1723 goto out;
1724 }
1725 }
1726
1727 if (old_ea_inode) {
1728 /* We are ready to release ref count on the old_ea_inode. */
1729 ret = ext4_xattr_inode_dec_ref(handle, old_ea_inode);
1730 if (ret) {
1731 /* Release newly required ref count on new_ea_inode. */
1732 if (new_ea_inode) {
1733 int err;
1734
1735 err = ext4_xattr_inode_dec_ref(handle,
1736 new_ea_inode);
1737 if (err)
1738 ext4_warning_inode(new_ea_inode,
1739 "dec ref new_ea_inode err=%d",
1740 err);
1741 ext4_xattr_inode_free_quota(inode, new_ea_inode,
1742 i->value_len);
1743 }
1744 goto out;
1745 }
1746
1747 ext4_xattr_inode_free_quota(inode, old_ea_inode,
1748 le32_to_cpu(here->e_value_size));
1749 }
1750
1751 /* No failures allowed past this point. */
1752
1753 if (!s->not_found && here->e_value_size && !here->e_value_inum) {
1754 /* Remove the old value. */
1755 void *first_val = s->base + min_offs;
1756 size_t offs = le16_to_cpu(here->e_value_offs);
1757 void *val = s->base + offs;
1758
1759 memmove(first_val + old_size, first_val, val - first_val);
1760 memset(first_val, 0, old_size);
1761 min_offs += old_size;
1762
1763 /* Adjust all value offsets. */
1764 last = s->first;
1765 while (!IS_LAST_ENTRY(last)) {
1766 size_t o = le16_to_cpu(last->e_value_offs);
1767
1768 if (!last->e_value_inum &&
1769 last->e_value_size && o < offs)
1770 last->e_value_offs = cpu_to_le16(o + old_size);
1771 last = EXT4_XATTR_NEXT(last);
1772 }
1773 }
1774
1775 if (!i->value) {
1776 /* Remove old name. */
1777 size_t size = EXT4_XATTR_LEN(name_len);
1778
1779 last = ENTRY((void *)last - size);
1780 memmove(here, (void *)here + size,
1781 (void *)last - (void *)here + sizeof(__u32));
1782 memset(last, 0, size);
1783
1784 /*
1785 * Update i_inline_off - moved ibody region might contain
1786 * system.data attribute. Handling a failure here won't
1787 * cause other complications for setting an xattr.
1788 */
1789 if (!is_block && ext4_has_inline_data(inode)) {
1790 ret = ext4_find_inline_data_nolock(inode);
1791 if (ret) {
1792 ext4_warning_inode(inode,
1793 "unable to update i_inline_off");
1794 goto out;
1795 }
1796 }
1797 } else if (s->not_found) {
1798 /* Insert new name. */
1799 size_t size = EXT4_XATTR_LEN(name_len);
1800 size_t rest = (void *)last - (void *)here + sizeof(__u32);
1801
1802 memmove((void *)here + size, here, rest);
1803 memset(here, 0, size);
1804 here->e_name_index = i->name_index;
1805 here->e_name_len = name_len;
1806 memcpy(here->e_name, i->name, name_len);
1807 } else {
1808 /* This is an update, reset value info. */
1809 here->e_value_inum = 0;
1810 here->e_value_offs = 0;
1811 here->e_value_size = 0;
1812 }
1813
1814 if (i->value) {
1815 /* Insert new value. */
1816 if (in_inode) {
1817 here->e_value_inum = cpu_to_le32(new_ea_inode->i_ino);
1818 } else if (i->value_len) {
1819 void *val = s->base + min_offs - new_size;
1820
1821 here->e_value_offs = cpu_to_le16(min_offs - new_size);
1822 if (i->value == EXT4_ZERO_XATTR_VALUE) {
1823 memset(val, 0, new_size);
1824 } else {
1825 memcpy(val, i->value, i->value_len);
1826 /* Clear padding bytes. */
1827 memset(val + i->value_len, 0,
1828 new_size - i->value_len);
1829 }
1830 }
1831 here->e_value_size = cpu_to_le32(i->value_len);
1832 }
1833
1834update_hash:
1835 if (i->value) {
1836 __le32 hash = 0;
1837
1838 /* Entry hash calculation. */
1839 if (in_inode) {
1840 __le32 crc32c_hash;
1841
1842 /*
1843 * Feed crc32c hash instead of the raw value for entry
1844 * hash calculation. This is to avoid walking
1845 * potentially long value buffer again.
1846 */
1847 crc32c_hash = cpu_to_le32(
1848 ext4_xattr_inode_get_hash(new_ea_inode));
1849 hash = ext4_xattr_hash_entry(here->e_name,
1850 here->e_name_len,
1851 &crc32c_hash, 1);
1852 } else if (is_block) {
1853 __le32 *value = s->base + le16_to_cpu(
1854 here->e_value_offs);
1855
1856 hash = ext4_xattr_hash_entry(here->e_name,
1857 here->e_name_len, value,
1858 new_size >> 2);
1859 }
1860 here->e_hash = hash;
1861 }
1862
1863 if (is_block)
1864 ext4_xattr_rehash((struct ext4_xattr_header *)s->base);
1865
1866 ret = 0;
1867out:
1868 iput(old_ea_inode);
1869 iput(new_ea_inode);
1870 return ret;
1871}
1872
1873struct ext4_xattr_block_find {
1874 struct ext4_xattr_search s;
1875 struct buffer_head *bh;
1876};
1877
1878static int
1879ext4_xattr_block_find(struct inode *inode, struct ext4_xattr_info *i,
1880 struct ext4_xattr_block_find *bs)
1881{
1882 struct super_block *sb = inode->i_sb;
1883 int error;
1884
1885 ea_idebug(inode, "name=%d.%s, value=%p, value_len=%ld",
1886 i->name_index, i->name, i->value, (long)i->value_len);
1887
1888 if (EXT4_I(inode)->i_file_acl) {
1889 /* The inode already has an extended attribute block. */
1890 bs->bh = ext4_sb_bread(sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
1891 if (IS_ERR(bs->bh)) {
1892 error = PTR_ERR(bs->bh);
1893 bs->bh = NULL;
1894 return error;
1895 }
1896 ea_bdebug(bs->bh, "b_count=%d, refcount=%d",
1897 atomic_read(&(bs->bh->b_count)),
1898 le32_to_cpu(BHDR(bs->bh)->h_refcount));
1899 error = ext4_xattr_check_block(inode, bs->bh);
1900 if (error)
1901 return error;
1902 /* Find the named attribute. */
1903 bs->s.base = BHDR(bs->bh);
1904 bs->s.first = BFIRST(bs->bh);
1905 bs->s.end = bs->bh->b_data + bs->bh->b_size;
1906 bs->s.here = bs->s.first;
1907 error = xattr_find_entry(inode, &bs->s.here, bs->s.end,
1908 i->name_index, i->name, 1);
1909 if (error && error != -ENODATA)
1910 return error;
1911 bs->s.not_found = error;
1912 }
1913 return 0;
1914}
1915
1916static int
1917ext4_xattr_block_set(handle_t *handle, struct inode *inode,
1918 struct ext4_xattr_info *i,
1919 struct ext4_xattr_block_find *bs)
1920{
1921 struct super_block *sb = inode->i_sb;
1922 struct buffer_head *new_bh = NULL;
1923 struct ext4_xattr_search s_copy = bs->s;
1924 struct ext4_xattr_search *s = &s_copy;
1925 struct mb_cache_entry *ce = NULL;
1926 int error = 0;
1927 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
1928 struct inode *ea_inode = NULL, *tmp_inode;
1929 size_t old_ea_inode_quota = 0;
1930 unsigned int ea_ino;
1931
1932
1933#define header(x) ((struct ext4_xattr_header *)(x))
1934
1935 if (s->base) {
1936 int offset = (char *)s->here - bs->bh->b_data;
1937
1938 BUFFER_TRACE(bs->bh, "get_write_access");
1939 error = ext4_journal_get_write_access(handle, sb, bs->bh,
1940 EXT4_JTR_NONE);
1941 if (error)
1942 goto cleanup;
1943 lock_buffer(bs->bh);
1944
1945 if (header(s->base)->h_refcount == cpu_to_le32(1)) {
1946 __u32 hash = le32_to_cpu(BHDR(bs->bh)->h_hash);
1947
1948 /*
1949 * This must happen under buffer lock for
1950 * ext4_xattr_block_set() to reliably detect modified
1951 * block
1952 */
1953 if (ea_block_cache) {
1954 struct mb_cache_entry *oe;
1955
1956 oe = mb_cache_entry_delete_or_get(ea_block_cache,
1957 hash, bs->bh->b_blocknr);
1958 if (oe) {
1959 /*
1960 * Xattr block is getting reused. Leave
1961 * it alone.
1962 */
1963 mb_cache_entry_put(ea_block_cache, oe);
1964 goto clone_block;
1965 }
1966 }
1967 ea_bdebug(bs->bh, "modifying in-place");
1968 error = ext4_xattr_set_entry(i, s, handle, inode,
1969 true /* is_block */);
1970 ext4_xattr_block_csum_set(inode, bs->bh);
1971 unlock_buffer(bs->bh);
1972 if (error == -EFSCORRUPTED)
1973 goto bad_block;
1974 if (!error)
1975 error = ext4_handle_dirty_metadata(handle,
1976 inode,
1977 bs->bh);
1978 if (error)
1979 goto cleanup;
1980 goto inserted;
1981 }
1982clone_block:
1983 unlock_buffer(bs->bh);
1984 ea_bdebug(bs->bh, "cloning");
1985 s->base = kmemdup(BHDR(bs->bh), bs->bh->b_size, GFP_NOFS);
1986 error = -ENOMEM;
1987 if (s->base == NULL)
1988 goto cleanup;
1989 s->first = ENTRY(header(s->base)+1);
1990 header(s->base)->h_refcount = cpu_to_le32(1);
1991 s->here = ENTRY(s->base + offset);
1992 s->end = s->base + bs->bh->b_size;
1993
1994 /*
1995 * If existing entry points to an xattr inode, we need
1996 * to prevent ext4_xattr_set_entry() from decrementing
1997 * ref count on it because the reference belongs to the
1998 * original block. In this case, make the entry look
1999 * like it has an empty value.
2000 */
2001 if (!s->not_found && s->here->e_value_inum) {
2002 ea_ino = le32_to_cpu(s->here->e_value_inum);
2003 error = ext4_xattr_inode_iget(inode, ea_ino,
2004 le32_to_cpu(s->here->e_hash),
2005 &tmp_inode);
2006 if (error)
2007 goto cleanup;
2008
2009 if (!ext4_test_inode_state(tmp_inode,
2010 EXT4_STATE_LUSTRE_EA_INODE)) {
2011 /*
2012 * Defer quota free call for previous
2013 * inode until success is guaranteed.
2014 */
2015 old_ea_inode_quota = le32_to_cpu(
2016 s->here->e_value_size);
2017 }
2018 iput(tmp_inode);
2019
2020 s->here->e_value_inum = 0;
2021 s->here->e_value_size = 0;
2022 }
2023 } else {
2024 /* Allocate a buffer where we construct the new block. */
2025 s->base = kzalloc(sb->s_blocksize, GFP_NOFS);
2026 error = -ENOMEM;
2027 if (s->base == NULL)
2028 goto cleanup;
2029 header(s->base)->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
2030 header(s->base)->h_blocks = cpu_to_le32(1);
2031 header(s->base)->h_refcount = cpu_to_le32(1);
2032 s->first = ENTRY(header(s->base)+1);
2033 s->here = ENTRY(header(s->base)+1);
2034 s->end = s->base + sb->s_blocksize;
2035 }
2036
2037 error = ext4_xattr_set_entry(i, s, handle, inode, true /* is_block */);
2038 if (error == -EFSCORRUPTED)
2039 goto bad_block;
2040 if (error)
2041 goto cleanup;
2042
2043 if (i->value && s->here->e_value_inum) {
2044 /*
2045 * A ref count on ea_inode has been taken as part of the call to
2046 * ext4_xattr_set_entry() above. We would like to drop this
2047 * extra ref but we have to wait until the xattr block is
2048 * initialized and has its own ref count on the ea_inode.
2049 */
2050 ea_ino = le32_to_cpu(s->here->e_value_inum);
2051 error = ext4_xattr_inode_iget(inode, ea_ino,
2052 le32_to_cpu(s->here->e_hash),
2053 &ea_inode);
2054 if (error) {
2055 ea_inode = NULL;
2056 goto cleanup;
2057 }
2058 }
2059
2060inserted:
2061 if (!IS_LAST_ENTRY(s->first)) {
2062 new_bh = ext4_xattr_block_cache_find(inode, header(s->base),
2063 &ce);
2064 if (new_bh) {
2065 /* We found an identical block in the cache. */
2066 if (new_bh == bs->bh)
2067 ea_bdebug(new_bh, "keeping");
2068 else {
2069 u32 ref;
2070
2071#ifdef EXT4_XATTR_DEBUG
2072 WARN_ON_ONCE(dquot_initialize_needed(inode));
2073#endif
2074 /* The old block is released after updating
2075 the inode. */
2076 error = dquot_alloc_block(inode,
2077 EXT4_C2B(EXT4_SB(sb), 1));
2078 if (error)
2079 goto cleanup;
2080 BUFFER_TRACE(new_bh, "get_write_access");
2081 error = ext4_journal_get_write_access(
2082 handle, sb, new_bh,
2083 EXT4_JTR_NONE);
2084 if (error)
2085 goto cleanup_dquot;
2086 lock_buffer(new_bh);
2087 /*
2088 * We have to be careful about races with
2089 * adding references to xattr block. Once we
2090 * hold buffer lock xattr block's state is
2091 * stable so we can check the additional
2092 * reference fits.
2093 */
2094 ref = le32_to_cpu(BHDR(new_bh)->h_refcount) + 1;
2095 if (ref > EXT4_XATTR_REFCOUNT_MAX) {
2096 /*
2097 * Undo everything and check mbcache
2098 * again.
2099 */
2100 unlock_buffer(new_bh);
2101 dquot_free_block(inode,
2102 EXT4_C2B(EXT4_SB(sb),
2103 1));
2104 brelse(new_bh);
2105 mb_cache_entry_put(ea_block_cache, ce);
2106 ce = NULL;
2107 new_bh = NULL;
2108 goto inserted;
2109 }
2110 BHDR(new_bh)->h_refcount = cpu_to_le32(ref);
2111 if (ref == EXT4_XATTR_REFCOUNT_MAX)
2112 clear_bit(MBE_REUSABLE_B, &ce->e_flags);
2113 ea_bdebug(new_bh, "reusing; refcount now=%d",
2114 ref);
2115 ext4_xattr_block_csum_set(inode, new_bh);
2116 unlock_buffer(new_bh);
2117 error = ext4_handle_dirty_metadata(handle,
2118 inode,
2119 new_bh);
2120 if (error)
2121 goto cleanup_dquot;
2122 }
2123 mb_cache_entry_touch(ea_block_cache, ce);
2124 mb_cache_entry_put(ea_block_cache, ce);
2125 ce = NULL;
2126 } else if (bs->bh && s->base == bs->bh->b_data) {
2127 /* We were modifying this block in-place. */
2128 ea_bdebug(bs->bh, "keeping this block");
2129 ext4_xattr_block_cache_insert(ea_block_cache, bs->bh);
2130 new_bh = bs->bh;
2131 get_bh(new_bh);
2132 } else {
2133 /* We need to allocate a new block */
2134 ext4_fsblk_t goal, block;
2135
2136#ifdef EXT4_XATTR_DEBUG
2137 WARN_ON_ONCE(dquot_initialize_needed(inode));
2138#endif
2139 goal = ext4_group_first_block_no(sb,
2140 EXT4_I(inode)->i_block_group);
2141 block = ext4_new_meta_blocks(handle, inode, goal, 0,
2142 NULL, &error);
2143 if (error)
2144 goto cleanup;
2145
2146 ea_idebug(inode, "creating block %llu",
2147 (unsigned long long)block);
2148
2149 new_bh = sb_getblk(sb, block);
2150 if (unlikely(!new_bh)) {
2151 error = -ENOMEM;
2152getblk_failed:
2153 ext4_free_blocks(handle, inode, NULL, block, 1,
2154 EXT4_FREE_BLOCKS_METADATA);
2155 goto cleanup;
2156 }
2157 error = ext4_xattr_inode_inc_ref_all(handle, inode,
2158 ENTRY(header(s->base)+1));
2159 if (error)
2160 goto getblk_failed;
2161
2162 lock_buffer(new_bh);
2163 error = ext4_journal_get_create_access(handle, sb,
2164 new_bh, EXT4_JTR_NONE);
2165 if (error) {
2166 unlock_buffer(new_bh);
2167 error = -EIO;
2168 goto getblk_failed;
2169 }
2170 memcpy(new_bh->b_data, s->base, new_bh->b_size);
2171 ext4_xattr_block_csum_set(inode, new_bh);
2172 set_buffer_uptodate(new_bh);
2173 unlock_buffer(new_bh);
2174 ext4_xattr_block_cache_insert(ea_block_cache, new_bh);
2175 error = ext4_handle_dirty_metadata(handle, inode,
2176 new_bh);
2177 if (error)
2178 goto cleanup;
2179 }
2180 }
2181
2182 if (old_ea_inode_quota)
2183 ext4_xattr_inode_free_quota(inode, NULL, old_ea_inode_quota);
2184
2185 /* Update the inode. */
2186 EXT4_I(inode)->i_file_acl = new_bh ? new_bh->b_blocknr : 0;
2187
2188 /* Drop the previous xattr block. */
2189 if (bs->bh && bs->bh != new_bh) {
2190 struct ext4_xattr_inode_array *ea_inode_array = NULL;
2191
2192 ext4_xattr_release_block(handle, inode, bs->bh,
2193 &ea_inode_array,
2194 0 /* extra_credits */);
2195 ext4_xattr_inode_array_free(ea_inode_array);
2196 }
2197 error = 0;
2198
2199cleanup:
2200 if (ea_inode) {
2201 int error2;
2202
2203 error2 = ext4_xattr_inode_dec_ref(handle, ea_inode);
2204 if (error2)
2205 ext4_warning_inode(ea_inode, "dec ref error=%d",
2206 error2);
2207
2208 /* If there was an error, revert the quota charge. */
2209 if (error)
2210 ext4_xattr_inode_free_quota(inode, ea_inode,
2211 i_size_read(ea_inode));
2212 iput(ea_inode);
2213 }
2214 if (ce)
2215 mb_cache_entry_put(ea_block_cache, ce);
2216 brelse(new_bh);
2217 if (!(bs->bh && s->base == bs->bh->b_data))
2218 kfree(s->base);
2219
2220 return error;
2221
2222cleanup_dquot:
2223 dquot_free_block(inode, EXT4_C2B(EXT4_SB(sb), 1));
2224 goto cleanup;
2225
2226bad_block:
2227 EXT4_ERROR_INODE(inode, "bad block %llu",
2228 EXT4_I(inode)->i_file_acl);
2229 goto cleanup;
2230
2231#undef header
2232}
2233
2234int ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i,
2235 struct ext4_xattr_ibody_find *is)
2236{
2237 struct ext4_xattr_ibody_header *header;
2238 struct ext4_inode *raw_inode;
2239 int error;
2240
2241 if (!EXT4_INODE_HAS_XATTR_SPACE(inode))
2242 return 0;
2243
2244 raw_inode = ext4_raw_inode(&is->iloc);
2245 header = IHDR(inode, raw_inode);
2246 is->s.base = is->s.first = IFIRST(header);
2247 is->s.here = is->s.first;
2248 is->s.end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
2249 if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
2250 error = xattr_check_inode(inode, header, is->s.end);
2251 if (error)
2252 return error;
2253 /* Find the named attribute. */
2254 error = xattr_find_entry(inode, &is->s.here, is->s.end,
2255 i->name_index, i->name, 0);
2256 if (error && error != -ENODATA)
2257 return error;
2258 is->s.not_found = error;
2259 }
2260 return 0;
2261}
2262
2263int ext4_xattr_ibody_set(handle_t *handle, struct inode *inode,
2264 struct ext4_xattr_info *i,
2265 struct ext4_xattr_ibody_find *is)
2266{
2267 struct ext4_xattr_ibody_header *header;
2268 struct ext4_xattr_search *s = &is->s;
2269 int error;
2270
2271 if (!EXT4_INODE_HAS_XATTR_SPACE(inode))
2272 return -ENOSPC;
2273
2274 error = ext4_xattr_set_entry(i, s, handle, inode, false /* is_block */);
2275 if (error)
2276 return error;
2277 header = IHDR(inode, ext4_raw_inode(&is->iloc));
2278 if (!IS_LAST_ENTRY(s->first)) {
2279 header->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
2280 ext4_set_inode_state(inode, EXT4_STATE_XATTR);
2281 } else {
2282 header->h_magic = cpu_to_le32(0);
2283 ext4_clear_inode_state(inode, EXT4_STATE_XATTR);
2284 }
2285 return 0;
2286}
2287
2288static int ext4_xattr_value_same(struct ext4_xattr_search *s,
2289 struct ext4_xattr_info *i)
2290{
2291 void *value;
2292
2293 /* When e_value_inum is set the value is stored externally. */
2294 if (s->here->e_value_inum)
2295 return 0;
2296 if (le32_to_cpu(s->here->e_value_size) != i->value_len)
2297 return 0;
2298 value = ((void *)s->base) + le16_to_cpu(s->here->e_value_offs);
2299 return !memcmp(value, i->value, i->value_len);
2300}
2301
2302static struct buffer_head *ext4_xattr_get_block(struct inode *inode)
2303{
2304 struct buffer_head *bh;
2305 int error;
2306
2307 if (!EXT4_I(inode)->i_file_acl)
2308 return NULL;
2309 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
2310 if (IS_ERR(bh))
2311 return bh;
2312 error = ext4_xattr_check_block(inode, bh);
2313 if (error) {
2314 brelse(bh);
2315 return ERR_PTR(error);
2316 }
2317 return bh;
2318}
2319
2320/*
2321 * ext4_xattr_set_handle()
2322 *
2323 * Create, replace or remove an extended attribute for this inode. Value
2324 * is NULL to remove an existing extended attribute, and non-NULL to
2325 * either replace an existing extended attribute, or create a new extended
2326 * attribute. The flags XATTR_REPLACE and XATTR_CREATE
2327 * specify that an extended attribute must exist and must not exist
2328 * previous to the call, respectively.
2329 *
2330 * Returns 0, or a negative error number on failure.
2331 */
2332int
2333ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
2334 const char *name, const void *value, size_t value_len,
2335 int flags)
2336{
2337 struct ext4_xattr_info i = {
2338 .name_index = name_index,
2339 .name = name,
2340 .value = value,
2341 .value_len = value_len,
2342 .in_inode = 0,
2343 };
2344 struct ext4_xattr_ibody_find is = {
2345 .s = { .not_found = -ENODATA, },
2346 };
2347 struct ext4_xattr_block_find bs = {
2348 .s = { .not_found = -ENODATA, },
2349 };
2350 int no_expand;
2351 int error;
2352
2353 if (!name)
2354 return -EINVAL;
2355 if (strlen(name) > 255)
2356 return -ERANGE;
2357
2358 ext4_write_lock_xattr(inode, &no_expand);
2359
2360 /* Check journal credits under write lock. */
2361 if (ext4_handle_valid(handle)) {
2362 struct buffer_head *bh;
2363 int credits;
2364
2365 bh = ext4_xattr_get_block(inode);
2366 if (IS_ERR(bh)) {
2367 error = PTR_ERR(bh);
2368 goto cleanup;
2369 }
2370
2371 credits = __ext4_xattr_set_credits(inode->i_sb, inode, bh,
2372 value_len,
2373 flags & XATTR_CREATE);
2374 brelse(bh);
2375
2376 if (jbd2_handle_buffer_credits(handle) < credits) {
2377 error = -ENOSPC;
2378 goto cleanup;
2379 }
2380 WARN_ON_ONCE(!(current->flags & PF_MEMALLOC_NOFS));
2381 }
2382
2383 error = ext4_reserve_inode_write(handle, inode, &is.iloc);
2384 if (error)
2385 goto cleanup;
2386
2387 if (ext4_test_inode_state(inode, EXT4_STATE_NEW)) {
2388 struct ext4_inode *raw_inode = ext4_raw_inode(&is.iloc);
2389 memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size);
2390 ext4_clear_inode_state(inode, EXT4_STATE_NEW);
2391 }
2392
2393 error = ext4_xattr_ibody_find(inode, &i, &is);
2394 if (error)
2395 goto cleanup;
2396 if (is.s.not_found)
2397 error = ext4_xattr_block_find(inode, &i, &bs);
2398 if (error)
2399 goto cleanup;
2400 if (is.s.not_found && bs.s.not_found) {
2401 error = -ENODATA;
2402 if (flags & XATTR_REPLACE)
2403 goto cleanup;
2404 error = 0;
2405 if (!value)
2406 goto cleanup;
2407 } else {
2408 error = -EEXIST;
2409 if (flags & XATTR_CREATE)
2410 goto cleanup;
2411 }
2412
2413 if (!value) {
2414 if (!is.s.not_found)
2415 error = ext4_xattr_ibody_set(handle, inode, &i, &is);
2416 else if (!bs.s.not_found)
2417 error = ext4_xattr_block_set(handle, inode, &i, &bs);
2418 } else {
2419 error = 0;
2420 /* Xattr value did not change? Save us some work and bail out */
2421 if (!is.s.not_found && ext4_xattr_value_same(&is.s, &i))
2422 goto cleanup;
2423 if (!bs.s.not_found && ext4_xattr_value_same(&bs.s, &i))
2424 goto cleanup;
2425
2426 if (ext4_has_feature_ea_inode(inode->i_sb) &&
2427 (EXT4_XATTR_SIZE(i.value_len) >
2428 EXT4_XATTR_MIN_LARGE_EA_SIZE(inode->i_sb->s_blocksize)))
2429 i.in_inode = 1;
2430retry_inode:
2431 error = ext4_xattr_ibody_set(handle, inode, &i, &is);
2432 if (!error && !bs.s.not_found) {
2433 i.value = NULL;
2434 error = ext4_xattr_block_set(handle, inode, &i, &bs);
2435 } else if (error == -ENOSPC) {
2436 if (EXT4_I(inode)->i_file_acl && !bs.s.base) {
2437 brelse(bs.bh);
2438 bs.bh = NULL;
2439 error = ext4_xattr_block_find(inode, &i, &bs);
2440 if (error)
2441 goto cleanup;
2442 }
2443 error = ext4_xattr_block_set(handle, inode, &i, &bs);
2444 if (!error && !is.s.not_found) {
2445 i.value = NULL;
2446 error = ext4_xattr_ibody_set(handle, inode, &i,
2447 &is);
2448 } else if (error == -ENOSPC) {
2449 /*
2450 * Xattr does not fit in the block, store at
2451 * external inode if possible.
2452 */
2453 if (ext4_has_feature_ea_inode(inode->i_sb) &&
2454 i.value_len && !i.in_inode) {
2455 i.in_inode = 1;
2456 goto retry_inode;
2457 }
2458 }
2459 }
2460 }
2461 if (!error) {
2462 ext4_xattr_update_super_block(handle, inode->i_sb);
2463 inode_set_ctime_current(inode);
2464 inode_inc_iversion(inode);
2465 if (!value)
2466 no_expand = 0;
2467 error = ext4_mark_iloc_dirty(handle, inode, &is.iloc);
2468 /*
2469 * The bh is consumed by ext4_mark_iloc_dirty, even with
2470 * error != 0.
2471 */
2472 is.iloc.bh = NULL;
2473 if (IS_SYNC(inode))
2474 ext4_handle_sync(handle);
2475 }
2476 ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_XATTR, handle);
2477
2478cleanup:
2479 brelse(is.iloc.bh);
2480 brelse(bs.bh);
2481 ext4_write_unlock_xattr(inode, &no_expand);
2482 return error;
2483}
2484
2485int ext4_xattr_set_credits(struct inode *inode, size_t value_len,
2486 bool is_create, int *credits)
2487{
2488 struct buffer_head *bh;
2489 int err;
2490
2491 *credits = 0;
2492
2493 if (!EXT4_SB(inode->i_sb)->s_journal)
2494 return 0;
2495
2496 down_read(&EXT4_I(inode)->xattr_sem);
2497
2498 bh = ext4_xattr_get_block(inode);
2499 if (IS_ERR(bh)) {
2500 err = PTR_ERR(bh);
2501 } else {
2502 *credits = __ext4_xattr_set_credits(inode->i_sb, inode, bh,
2503 value_len, is_create);
2504 brelse(bh);
2505 err = 0;
2506 }
2507
2508 up_read(&EXT4_I(inode)->xattr_sem);
2509 return err;
2510}
2511
2512/*
2513 * ext4_xattr_set()
2514 *
2515 * Like ext4_xattr_set_handle, but start from an inode. This extended
2516 * attribute modification is a filesystem transaction by itself.
2517 *
2518 * Returns 0, or a negative error number on failure.
2519 */
2520int
2521ext4_xattr_set(struct inode *inode, int name_index, const char *name,
2522 const void *value, size_t value_len, int flags)
2523{
2524 handle_t *handle;
2525 struct super_block *sb = inode->i_sb;
2526 int error, retries = 0;
2527 int credits;
2528
2529 error = dquot_initialize(inode);
2530 if (error)
2531 return error;
2532
2533retry:
2534 error = ext4_xattr_set_credits(inode, value_len, flags & XATTR_CREATE,
2535 &credits);
2536 if (error)
2537 return error;
2538
2539 handle = ext4_journal_start(inode, EXT4_HT_XATTR, credits);
2540 if (IS_ERR(handle)) {
2541 error = PTR_ERR(handle);
2542 } else {
2543 int error2;
2544
2545 error = ext4_xattr_set_handle(handle, inode, name_index, name,
2546 value, value_len, flags);
2547 error2 = ext4_journal_stop(handle);
2548 if (error == -ENOSPC &&
2549 ext4_should_retry_alloc(sb, &retries))
2550 goto retry;
2551 if (error == 0)
2552 error = error2;
2553 }
2554 ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_XATTR, NULL);
2555
2556 return error;
2557}
2558
2559/*
2560 * Shift the EA entries in the inode to create space for the increased
2561 * i_extra_isize.
2562 */
2563static void ext4_xattr_shift_entries(struct ext4_xattr_entry *entry,
2564 int value_offs_shift, void *to,
2565 void *from, size_t n)
2566{
2567 struct ext4_xattr_entry *last = entry;
2568 int new_offs;
2569
2570 /* We always shift xattr headers further thus offsets get lower */
2571 BUG_ON(value_offs_shift > 0);
2572
2573 /* Adjust the value offsets of the entries */
2574 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
2575 if (!last->e_value_inum && last->e_value_size) {
2576 new_offs = le16_to_cpu(last->e_value_offs) +
2577 value_offs_shift;
2578 last->e_value_offs = cpu_to_le16(new_offs);
2579 }
2580 }
2581 /* Shift the entries by n bytes */
2582 memmove(to, from, n);
2583}
2584
2585/*
2586 * Move xattr pointed to by 'entry' from inode into external xattr block
2587 */
2588static int ext4_xattr_move_to_block(handle_t *handle, struct inode *inode,
2589 struct ext4_inode *raw_inode,
2590 struct ext4_xattr_entry *entry)
2591{
2592 struct ext4_xattr_ibody_find *is = NULL;
2593 struct ext4_xattr_block_find *bs = NULL;
2594 char *buffer = NULL, *b_entry_name = NULL;
2595 size_t value_size = le32_to_cpu(entry->e_value_size);
2596 struct ext4_xattr_info i = {
2597 .value = NULL,
2598 .value_len = 0,
2599 .name_index = entry->e_name_index,
2600 .in_inode = !!entry->e_value_inum,
2601 };
2602 struct ext4_xattr_ibody_header *header = IHDR(inode, raw_inode);
2603 int needs_kvfree = 0;
2604 int error;
2605
2606 is = kzalloc(sizeof(struct ext4_xattr_ibody_find), GFP_NOFS);
2607 bs = kzalloc(sizeof(struct ext4_xattr_block_find), GFP_NOFS);
2608 b_entry_name = kmalloc(entry->e_name_len + 1, GFP_NOFS);
2609 if (!is || !bs || !b_entry_name) {
2610 error = -ENOMEM;
2611 goto out;
2612 }
2613
2614 is->s.not_found = -ENODATA;
2615 bs->s.not_found = -ENODATA;
2616 is->iloc.bh = NULL;
2617 bs->bh = NULL;
2618
2619 /* Save the entry name and the entry value */
2620 if (entry->e_value_inum) {
2621 buffer = kvmalloc(value_size, GFP_NOFS);
2622 if (!buffer) {
2623 error = -ENOMEM;
2624 goto out;
2625 }
2626 needs_kvfree = 1;
2627 error = ext4_xattr_inode_get(inode, entry, buffer, value_size);
2628 if (error)
2629 goto out;
2630 } else {
2631 size_t value_offs = le16_to_cpu(entry->e_value_offs);
2632 buffer = (void *)IFIRST(header) + value_offs;
2633 }
2634
2635 memcpy(b_entry_name, entry->e_name, entry->e_name_len);
2636 b_entry_name[entry->e_name_len] = '\0';
2637 i.name = b_entry_name;
2638
2639 error = ext4_get_inode_loc(inode, &is->iloc);
2640 if (error)
2641 goto out;
2642
2643 error = ext4_xattr_ibody_find(inode, &i, is);
2644 if (error)
2645 goto out;
2646
2647 i.value = buffer;
2648 i.value_len = value_size;
2649 error = ext4_xattr_block_find(inode, &i, bs);
2650 if (error)
2651 goto out;
2652
2653 /* Move ea entry from the inode into the block */
2654 error = ext4_xattr_block_set(handle, inode, &i, bs);
2655 if (error)
2656 goto out;
2657
2658 /* Remove the chosen entry from the inode */
2659 i.value = NULL;
2660 i.value_len = 0;
2661 error = ext4_xattr_ibody_set(handle, inode, &i, is);
2662
2663out:
2664 kfree(b_entry_name);
2665 if (needs_kvfree && buffer)
2666 kvfree(buffer);
2667 if (is)
2668 brelse(is->iloc.bh);
2669 if (bs)
2670 brelse(bs->bh);
2671 kfree(is);
2672 kfree(bs);
2673
2674 return error;
2675}
2676
2677static int ext4_xattr_make_inode_space(handle_t *handle, struct inode *inode,
2678 struct ext4_inode *raw_inode,
2679 int isize_diff, size_t ifree,
2680 size_t bfree, int *total_ino)
2681{
2682 struct ext4_xattr_ibody_header *header = IHDR(inode, raw_inode);
2683 struct ext4_xattr_entry *small_entry;
2684 struct ext4_xattr_entry *entry;
2685 struct ext4_xattr_entry *last;
2686 unsigned int entry_size; /* EA entry size */
2687 unsigned int total_size; /* EA entry size + value size */
2688 unsigned int min_total_size;
2689 int error;
2690
2691 while (isize_diff > ifree) {
2692 entry = NULL;
2693 small_entry = NULL;
2694 min_total_size = ~0U;
2695 last = IFIRST(header);
2696 /* Find the entry best suited to be pushed into EA block */
2697 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
2698 /* never move system.data out of the inode */
2699 if ((last->e_name_len == 4) &&
2700 (last->e_name_index == EXT4_XATTR_INDEX_SYSTEM) &&
2701 !memcmp(last->e_name, "data", 4))
2702 continue;
2703 total_size = EXT4_XATTR_LEN(last->e_name_len);
2704 if (!last->e_value_inum)
2705 total_size += EXT4_XATTR_SIZE(
2706 le32_to_cpu(last->e_value_size));
2707 if (total_size <= bfree &&
2708 total_size < min_total_size) {
2709 if (total_size + ifree < isize_diff) {
2710 small_entry = last;
2711 } else {
2712 entry = last;
2713 min_total_size = total_size;
2714 }
2715 }
2716 }
2717
2718 if (entry == NULL) {
2719 if (small_entry == NULL)
2720 return -ENOSPC;
2721 entry = small_entry;
2722 }
2723
2724 entry_size = EXT4_XATTR_LEN(entry->e_name_len);
2725 total_size = entry_size;
2726 if (!entry->e_value_inum)
2727 total_size += EXT4_XATTR_SIZE(
2728 le32_to_cpu(entry->e_value_size));
2729 error = ext4_xattr_move_to_block(handle, inode, raw_inode,
2730 entry);
2731 if (error)
2732 return error;
2733
2734 *total_ino -= entry_size;
2735 ifree += total_size;
2736 bfree -= total_size;
2737 }
2738
2739 return 0;
2740}
2741
2742/*
2743 * Expand an inode by new_extra_isize bytes when EAs are present.
2744 * Returns 0 on success or negative error number on failure.
2745 */
2746int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
2747 struct ext4_inode *raw_inode, handle_t *handle)
2748{
2749 struct ext4_xattr_ibody_header *header;
2750 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2751 static unsigned int mnt_count;
2752 size_t min_offs;
2753 size_t ifree, bfree;
2754 int total_ino;
2755 void *base, *end;
2756 int error = 0, tried_min_extra_isize = 0;
2757 int s_min_extra_isize = le16_to_cpu(sbi->s_es->s_min_extra_isize);
2758 int isize_diff; /* How much do we need to grow i_extra_isize */
2759
2760retry:
2761 isize_diff = new_extra_isize - EXT4_I(inode)->i_extra_isize;
2762 if (EXT4_I(inode)->i_extra_isize >= new_extra_isize)
2763 return 0;
2764
2765 header = IHDR(inode, raw_inode);
2766
2767 /*
2768 * Check if enough free space is available in the inode to shift the
2769 * entries ahead by new_extra_isize.
2770 */
2771
2772 base = IFIRST(header);
2773 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
2774 min_offs = end - base;
2775 total_ino = sizeof(struct ext4_xattr_ibody_header) + sizeof(u32);
2776
2777 error = xattr_check_inode(inode, header, end);
2778 if (error)
2779 goto cleanup;
2780
2781 ifree = ext4_xattr_free_space(base, &min_offs, base, &total_ino);
2782 if (ifree >= isize_diff)
2783 goto shift;
2784
2785 /*
2786 * Enough free space isn't available in the inode, check if
2787 * EA block can hold new_extra_isize bytes.
2788 */
2789 if (EXT4_I(inode)->i_file_acl) {
2790 struct buffer_head *bh;
2791
2792 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
2793 if (IS_ERR(bh)) {
2794 error = PTR_ERR(bh);
2795 goto cleanup;
2796 }
2797 error = ext4_xattr_check_block(inode, bh);
2798 if (error) {
2799 brelse(bh);
2800 goto cleanup;
2801 }
2802 base = BHDR(bh);
2803 end = bh->b_data + bh->b_size;
2804 min_offs = end - base;
2805 bfree = ext4_xattr_free_space(BFIRST(bh), &min_offs, base,
2806 NULL);
2807 brelse(bh);
2808 if (bfree + ifree < isize_diff) {
2809 if (!tried_min_extra_isize && s_min_extra_isize) {
2810 tried_min_extra_isize++;
2811 new_extra_isize = s_min_extra_isize;
2812 goto retry;
2813 }
2814 error = -ENOSPC;
2815 goto cleanup;
2816 }
2817 } else {
2818 bfree = inode->i_sb->s_blocksize;
2819 }
2820
2821 error = ext4_xattr_make_inode_space(handle, inode, raw_inode,
2822 isize_diff, ifree, bfree,
2823 &total_ino);
2824 if (error) {
2825 if (error == -ENOSPC && !tried_min_extra_isize &&
2826 s_min_extra_isize) {
2827 tried_min_extra_isize++;
2828 new_extra_isize = s_min_extra_isize;
2829 goto retry;
2830 }
2831 goto cleanup;
2832 }
2833shift:
2834 /* Adjust the offsets and shift the remaining entries ahead */
2835 ext4_xattr_shift_entries(IFIRST(header), EXT4_I(inode)->i_extra_isize
2836 - new_extra_isize, (void *)raw_inode +
2837 EXT4_GOOD_OLD_INODE_SIZE + new_extra_isize,
2838 (void *)header, total_ino);
2839 EXT4_I(inode)->i_extra_isize = new_extra_isize;
2840
2841 if (ext4_has_inline_data(inode))
2842 error = ext4_find_inline_data_nolock(inode);
2843
2844cleanup:
2845 if (error && (mnt_count != le16_to_cpu(sbi->s_es->s_mnt_count))) {
2846 ext4_warning(inode->i_sb, "Unable to expand inode %lu. Delete some EAs or run e2fsck.",
2847 inode->i_ino);
2848 mnt_count = le16_to_cpu(sbi->s_es->s_mnt_count);
2849 }
2850 return error;
2851}
2852
2853#define EIA_INCR 16 /* must be 2^n */
2854#define EIA_MASK (EIA_INCR - 1)
2855
2856/* Add the large xattr @inode into @ea_inode_array for deferred iput().
2857 * If @ea_inode_array is new or full it will be grown and the old
2858 * contents copied over.
2859 */
2860static int
2861ext4_expand_inode_array(struct ext4_xattr_inode_array **ea_inode_array,
2862 struct inode *inode)
2863{
2864 if (*ea_inode_array == NULL) {
2865 /*
2866 * Start with 15 inodes, so it fits into a power-of-two size.
2867 * If *ea_inode_array is NULL, this is essentially offsetof()
2868 */
2869 (*ea_inode_array) =
2870 kmalloc(offsetof(struct ext4_xattr_inode_array,
2871 inodes[EIA_MASK]),
2872 GFP_NOFS);
2873 if (*ea_inode_array == NULL)
2874 return -ENOMEM;
2875 (*ea_inode_array)->count = 0;
2876 } else if (((*ea_inode_array)->count & EIA_MASK) == EIA_MASK) {
2877 /* expand the array once all 15 + n * 16 slots are full */
2878 struct ext4_xattr_inode_array *new_array = NULL;
2879 int count = (*ea_inode_array)->count;
2880
2881 /* if new_array is NULL, this is essentially offsetof() */
2882 new_array = kmalloc(
2883 offsetof(struct ext4_xattr_inode_array,
2884 inodes[count + EIA_INCR]),
2885 GFP_NOFS);
2886 if (new_array == NULL)
2887 return -ENOMEM;
2888 memcpy(new_array, *ea_inode_array,
2889 offsetof(struct ext4_xattr_inode_array, inodes[count]));
2890 kfree(*ea_inode_array);
2891 *ea_inode_array = new_array;
2892 }
2893 (*ea_inode_array)->inodes[(*ea_inode_array)->count++] = inode;
2894 return 0;
2895}
2896
2897/*
2898 * ext4_xattr_delete_inode()
2899 *
2900 * Free extended attribute resources associated with this inode. Traverse
2901 * all entries and decrement reference on any xattr inodes associated with this
2902 * inode. This is called immediately before an inode is freed. We have exclusive
2903 * access to the inode. If an orphan inode is deleted it will also release its
2904 * references on xattr block and xattr inodes.
2905 */
2906int ext4_xattr_delete_inode(handle_t *handle, struct inode *inode,
2907 struct ext4_xattr_inode_array **ea_inode_array,
2908 int extra_credits)
2909{
2910 struct buffer_head *bh = NULL;
2911 struct ext4_xattr_ibody_header *header;
2912 struct ext4_iloc iloc = { .bh = NULL };
2913 struct ext4_xattr_entry *entry;
2914 struct inode *ea_inode;
2915 int error;
2916
2917 error = ext4_journal_ensure_credits(handle, extra_credits,
2918 ext4_free_metadata_revoke_credits(inode->i_sb, 1));
2919 if (error < 0) {
2920 EXT4_ERROR_INODE(inode, "ensure credits (error %d)", error);
2921 goto cleanup;
2922 }
2923
2924 if (ext4_has_feature_ea_inode(inode->i_sb) &&
2925 ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
2926
2927 error = ext4_get_inode_loc(inode, &iloc);
2928 if (error) {
2929 EXT4_ERROR_INODE(inode, "inode loc (error %d)", error);
2930 goto cleanup;
2931 }
2932
2933 error = ext4_journal_get_write_access(handle, inode->i_sb,
2934 iloc.bh, EXT4_JTR_NONE);
2935 if (error) {
2936 EXT4_ERROR_INODE(inode, "write access (error %d)",
2937 error);
2938 goto cleanup;
2939 }
2940
2941 header = IHDR(inode, ext4_raw_inode(&iloc));
2942 if (header->h_magic == cpu_to_le32(EXT4_XATTR_MAGIC))
2943 ext4_xattr_inode_dec_ref_all(handle, inode, iloc.bh,
2944 IFIRST(header),
2945 false /* block_csum */,
2946 ea_inode_array,
2947 extra_credits,
2948 false /* skip_quota */);
2949 }
2950
2951 if (EXT4_I(inode)->i_file_acl) {
2952 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
2953 if (IS_ERR(bh)) {
2954 error = PTR_ERR(bh);
2955 if (error == -EIO) {
2956 EXT4_ERROR_INODE_ERR(inode, EIO,
2957 "block %llu read error",
2958 EXT4_I(inode)->i_file_acl);
2959 }
2960 bh = NULL;
2961 goto cleanup;
2962 }
2963 error = ext4_xattr_check_block(inode, bh);
2964 if (error)
2965 goto cleanup;
2966
2967 if (ext4_has_feature_ea_inode(inode->i_sb)) {
2968 for (entry = BFIRST(bh); !IS_LAST_ENTRY(entry);
2969 entry = EXT4_XATTR_NEXT(entry)) {
2970 if (!entry->e_value_inum)
2971 continue;
2972 error = ext4_xattr_inode_iget(inode,
2973 le32_to_cpu(entry->e_value_inum),
2974 le32_to_cpu(entry->e_hash),
2975 &ea_inode);
2976 if (error)
2977 continue;
2978 ext4_xattr_inode_free_quota(inode, ea_inode,
2979 le32_to_cpu(entry->e_value_size));
2980 iput(ea_inode);
2981 }
2982
2983 }
2984
2985 ext4_xattr_release_block(handle, inode, bh, ea_inode_array,
2986 extra_credits);
2987 /*
2988 * Update i_file_acl value in the same transaction that releases
2989 * block.
2990 */
2991 EXT4_I(inode)->i_file_acl = 0;
2992 error = ext4_mark_inode_dirty(handle, inode);
2993 if (error) {
2994 EXT4_ERROR_INODE(inode, "mark inode dirty (error %d)",
2995 error);
2996 goto cleanup;
2997 }
2998 ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_XATTR, handle);
2999 }
3000 error = 0;
3001cleanup:
3002 brelse(iloc.bh);
3003 brelse(bh);
3004 return error;
3005}
3006
3007void ext4_xattr_inode_array_free(struct ext4_xattr_inode_array *ea_inode_array)
3008{
3009 int idx;
3010
3011 if (ea_inode_array == NULL)
3012 return;
3013
3014 for (idx = 0; idx < ea_inode_array->count; ++idx)
3015 iput(ea_inode_array->inodes[idx]);
3016 kfree(ea_inode_array);
3017}
3018
3019/*
3020 * ext4_xattr_block_cache_insert()
3021 *
3022 * Create a new entry in the extended attribute block cache, and insert
3023 * it unless such an entry is already in the cache.
3024 *
3025 * Returns 0, or a negative error number on failure.
3026 */
3027static void
3028ext4_xattr_block_cache_insert(struct mb_cache *ea_block_cache,
3029 struct buffer_head *bh)
3030{
3031 struct ext4_xattr_header *header = BHDR(bh);
3032 __u32 hash = le32_to_cpu(header->h_hash);
3033 int reusable = le32_to_cpu(header->h_refcount) <
3034 EXT4_XATTR_REFCOUNT_MAX;
3035 int error;
3036
3037 if (!ea_block_cache)
3038 return;
3039 error = mb_cache_entry_create(ea_block_cache, GFP_NOFS, hash,
3040 bh->b_blocknr, reusable);
3041 if (error) {
3042 if (error == -EBUSY)
3043 ea_bdebug(bh, "already in cache");
3044 } else
3045 ea_bdebug(bh, "inserting [%x]", (int)hash);
3046}
3047
3048/*
3049 * ext4_xattr_cmp()
3050 *
3051 * Compare two extended attribute blocks for equality.
3052 *
3053 * Returns 0 if the blocks are equal, 1 if they differ, and
3054 * a negative error number on errors.
3055 */
3056static int
3057ext4_xattr_cmp(struct ext4_xattr_header *header1,
3058 struct ext4_xattr_header *header2)
3059{
3060 struct ext4_xattr_entry *entry1, *entry2;
3061
3062 entry1 = ENTRY(header1+1);
3063 entry2 = ENTRY(header2+1);
3064 while (!IS_LAST_ENTRY(entry1)) {
3065 if (IS_LAST_ENTRY(entry2))
3066 return 1;
3067 if (entry1->e_hash != entry2->e_hash ||
3068 entry1->e_name_index != entry2->e_name_index ||
3069 entry1->e_name_len != entry2->e_name_len ||
3070 entry1->e_value_size != entry2->e_value_size ||
3071 entry1->e_value_inum != entry2->e_value_inum ||
3072 memcmp(entry1->e_name, entry2->e_name, entry1->e_name_len))
3073 return 1;
3074 if (!entry1->e_value_inum &&
3075 memcmp((char *)header1 + le16_to_cpu(entry1->e_value_offs),
3076 (char *)header2 + le16_to_cpu(entry2->e_value_offs),
3077 le32_to_cpu(entry1->e_value_size)))
3078 return 1;
3079
3080 entry1 = EXT4_XATTR_NEXT(entry1);
3081 entry2 = EXT4_XATTR_NEXT(entry2);
3082 }
3083 if (!IS_LAST_ENTRY(entry2))
3084 return 1;
3085 return 0;
3086}
3087
3088/*
3089 * ext4_xattr_block_cache_find()
3090 *
3091 * Find an identical extended attribute block.
3092 *
3093 * Returns a pointer to the block found, or NULL if such a block was
3094 * not found or an error occurred.
3095 */
3096static struct buffer_head *
3097ext4_xattr_block_cache_find(struct inode *inode,
3098 struct ext4_xattr_header *header,
3099 struct mb_cache_entry **pce)
3100{
3101 __u32 hash = le32_to_cpu(header->h_hash);
3102 struct mb_cache_entry *ce;
3103 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
3104
3105 if (!ea_block_cache)
3106 return NULL;
3107 if (!header->h_hash)
3108 return NULL; /* never share */
3109 ea_idebug(inode, "looking for cached blocks [%x]", (int)hash);
3110 ce = mb_cache_entry_find_first(ea_block_cache, hash);
3111 while (ce) {
3112 struct buffer_head *bh;
3113
3114 bh = ext4_sb_bread(inode->i_sb, ce->e_value, REQ_PRIO);
3115 if (IS_ERR(bh)) {
3116 if (PTR_ERR(bh) == -ENOMEM)
3117 return NULL;
3118 bh = NULL;
3119 EXT4_ERROR_INODE(inode, "block %lu read error",
3120 (unsigned long)ce->e_value);
3121 } else if (ext4_xattr_cmp(header, BHDR(bh)) == 0) {
3122 *pce = ce;
3123 return bh;
3124 }
3125 brelse(bh);
3126 ce = mb_cache_entry_find_next(ea_block_cache, ce);
3127 }
3128 return NULL;
3129}
3130
3131#define NAME_HASH_SHIFT 5
3132#define VALUE_HASH_SHIFT 16
3133
3134/*
3135 * ext4_xattr_hash_entry()
3136 *
3137 * Compute the hash of an extended attribute.
3138 */
3139static __le32 ext4_xattr_hash_entry(char *name, size_t name_len, __le32 *value,
3140 size_t value_count)
3141{
3142 __u32 hash = 0;
3143
3144 while (name_len--) {
3145 hash = (hash << NAME_HASH_SHIFT) ^
3146 (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^
3147 (unsigned char)*name++;
3148 }
3149 while (value_count--) {
3150 hash = (hash << VALUE_HASH_SHIFT) ^
3151 (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^
3152 le32_to_cpu(*value++);
3153 }
3154 return cpu_to_le32(hash);
3155}
3156
3157/*
3158 * ext4_xattr_hash_entry_signed()
3159 *
3160 * Compute the hash of an extended attribute incorrectly.
3161 */
3162static __le32 ext4_xattr_hash_entry_signed(char *name, size_t name_len, __le32 *value, size_t value_count)
3163{
3164 __u32 hash = 0;
3165
3166 while (name_len--) {
3167 hash = (hash << NAME_HASH_SHIFT) ^
3168 (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^
3169 (signed char)*name++;
3170 }
3171 while (value_count--) {
3172 hash = (hash << VALUE_HASH_SHIFT) ^
3173 (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^
3174 le32_to_cpu(*value++);
3175 }
3176 return cpu_to_le32(hash);
3177}
3178
3179#undef NAME_HASH_SHIFT
3180#undef VALUE_HASH_SHIFT
3181
3182#define BLOCK_HASH_SHIFT 16
3183
3184/*
3185 * ext4_xattr_rehash()
3186 *
3187 * Re-compute the extended attribute hash value after an entry has changed.
3188 */
3189static void ext4_xattr_rehash(struct ext4_xattr_header *header)
3190{
3191 struct ext4_xattr_entry *here;
3192 __u32 hash = 0;
3193
3194 here = ENTRY(header+1);
3195 while (!IS_LAST_ENTRY(here)) {
3196 if (!here->e_hash) {
3197 /* Block is not shared if an entry's hash value == 0 */
3198 hash = 0;
3199 break;
3200 }
3201 hash = (hash << BLOCK_HASH_SHIFT) ^
3202 (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^
3203 le32_to_cpu(here->e_hash);
3204 here = EXT4_XATTR_NEXT(here);
3205 }
3206 header->h_hash = cpu_to_le32(hash);
3207}
3208
3209#undef BLOCK_HASH_SHIFT
3210
3211#define HASH_BUCKET_BITS 10
3212
3213struct mb_cache *
3214ext4_xattr_create_cache(void)
3215{
3216 return mb_cache_create(HASH_BUCKET_BITS);
3217}
3218
3219void ext4_xattr_destroy_cache(struct mb_cache *cache)
3220{
3221 if (cache)
3222 mb_cache_destroy(cache);
3223}
3224