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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(f...)
86# define ea_bdebug(f...)
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 inline const struct xattr_handler *
126ext4_xattr_handler(int name_index)
127{
128 const struct xattr_handler *handler = NULL;
129
130 if (name_index > 0 && name_index < ARRAY_SIZE(ext4_xattr_handler_map))
131 handler = ext4_xattr_handler_map[name_index];
132 return handler;
133}
134
135/*
136 * Inode operation listxattr()
137 *
138 * dentry->d_inode->i_mutex: don't care
139 */
140ssize_t
141ext4_listxattr(struct dentry *dentry, char *buffer, size_t size)
142{
143 return ext4_xattr_list(dentry, buffer, size);
144}
145
146static int
147ext4_xattr_check_names(struct ext4_xattr_entry *entry, void *end)
148{
149 while (!IS_LAST_ENTRY(entry)) {
150 struct ext4_xattr_entry *next = EXT4_XATTR_NEXT(entry);
151 if ((void *)next >= end)
152 return -EIO;
153 entry = next;
154 }
155 return 0;
156}
157
158static inline int
159ext4_xattr_check_block(struct buffer_head *bh)
160{
161 int error;
162
163 if (BHDR(bh)->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC) ||
164 BHDR(bh)->h_blocks != cpu_to_le32(1))
165 return -EIO;
166 error = ext4_xattr_check_names(BFIRST(bh), bh->b_data + bh->b_size);
167 return error;
168}
169
170static inline int
171ext4_xattr_check_entry(struct ext4_xattr_entry *entry, size_t size)
172{
173 size_t value_size = le32_to_cpu(entry->e_value_size);
174
175 if (entry->e_value_block != 0 || value_size > size ||
176 le16_to_cpu(entry->e_value_offs) + value_size > size)
177 return -EIO;
178 return 0;
179}
180
181static int
182ext4_xattr_find_entry(struct ext4_xattr_entry **pentry, int name_index,
183 const char *name, size_t size, int sorted)
184{
185 struct ext4_xattr_entry *entry;
186 size_t name_len;
187 int cmp = 1;
188
189 if (name == NULL)
190 return -EINVAL;
191 name_len = strlen(name);
192 entry = *pentry;
193 for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) {
194 cmp = name_index - entry->e_name_index;
195 if (!cmp)
196 cmp = name_len - entry->e_name_len;
197 if (!cmp)
198 cmp = memcmp(name, entry->e_name, name_len);
199 if (cmp <= 0 && (sorted || cmp == 0))
200 break;
201 }
202 *pentry = entry;
203 if (!cmp && ext4_xattr_check_entry(entry, size))
204 return -EIO;
205 return cmp ? -ENODATA : 0;
206}
207
208static int
209ext4_xattr_block_get(struct inode *inode, int name_index, const char *name,
210 void *buffer, size_t buffer_size)
211{
212 struct buffer_head *bh = NULL;
213 struct ext4_xattr_entry *entry;
214 size_t size;
215 int error;
216
217 ea_idebug(inode, "name=%d.%s, buffer=%p, buffer_size=%ld",
218 name_index, name, buffer, (long)buffer_size);
219
220 error = -ENODATA;
221 if (!EXT4_I(inode)->i_file_acl)
222 goto cleanup;
223 ea_idebug(inode, "reading block %u", EXT4_I(inode)->i_file_acl);
224 bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl);
225 if (!bh)
226 goto cleanup;
227 ea_bdebug(bh, "b_count=%d, refcount=%d",
228 atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount));
229 if (ext4_xattr_check_block(bh)) {
230bad_block:
231 EXT4_ERROR_INODE(inode, "bad block %llu",
232 EXT4_I(inode)->i_file_acl);
233 error = -EIO;
234 goto cleanup;
235 }
236 ext4_xattr_cache_insert(bh);
237 entry = BFIRST(bh);
238 error = ext4_xattr_find_entry(&entry, name_index, name, bh->b_size, 1);
239 if (error == -EIO)
240 goto bad_block;
241 if (error)
242 goto cleanup;
243 size = le32_to_cpu(entry->e_value_size);
244 if (buffer) {
245 error = -ERANGE;
246 if (size > buffer_size)
247 goto cleanup;
248 memcpy(buffer, bh->b_data + le16_to_cpu(entry->e_value_offs),
249 size);
250 }
251 error = size;
252
253cleanup:
254 brelse(bh);
255 return error;
256}
257
258static int
259ext4_xattr_ibody_get(struct inode *inode, int name_index, const char *name,
260 void *buffer, size_t buffer_size)
261{
262 struct ext4_xattr_ibody_header *header;
263 struct ext4_xattr_entry *entry;
264 struct ext4_inode *raw_inode;
265 struct ext4_iloc iloc;
266 size_t size;
267 void *end;
268 int error;
269
270 if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR))
271 return -ENODATA;
272 error = ext4_get_inode_loc(inode, &iloc);
273 if (error)
274 return error;
275 raw_inode = ext4_raw_inode(&iloc);
276 header = IHDR(inode, raw_inode);
277 entry = IFIRST(header);
278 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
279 error = ext4_xattr_check_names(entry, end);
280 if (error)
281 goto cleanup;
282 error = ext4_xattr_find_entry(&entry, name_index, name,
283 end - (void *)entry, 0);
284 if (error)
285 goto cleanup;
286 size = le32_to_cpu(entry->e_value_size);
287 if (buffer) {
288 error = -ERANGE;
289 if (size > buffer_size)
290 goto cleanup;
291 memcpy(buffer, (void *)IFIRST(header) +
292 le16_to_cpu(entry->e_value_offs), size);
293 }
294 error = size;
295
296cleanup:
297 brelse(iloc.bh);
298 return error;
299}
300
301/*
302 * ext4_xattr_get()
303 *
304 * Copy an extended attribute into the buffer
305 * provided, or compute the buffer size required.
306 * Buffer is NULL to compute the size of the buffer required.
307 *
308 * Returns a negative error number on failure, or the number of bytes
309 * used / required on success.
310 */
311int
312ext4_xattr_get(struct inode *inode, int name_index, const char *name,
313 void *buffer, size_t buffer_size)
314{
315 int error;
316
317 down_read(&EXT4_I(inode)->xattr_sem);
318 error = ext4_xattr_ibody_get(inode, name_index, name, buffer,
319 buffer_size);
320 if (error == -ENODATA)
321 error = ext4_xattr_block_get(inode, name_index, name, buffer,
322 buffer_size);
323 up_read(&EXT4_I(inode)->xattr_sem);
324 return error;
325}
326
327static int
328ext4_xattr_list_entries(struct dentry *dentry, struct ext4_xattr_entry *entry,
329 char *buffer, size_t buffer_size)
330{
331 size_t rest = buffer_size;
332
333 for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) {
334 const struct xattr_handler *handler =
335 ext4_xattr_handler(entry->e_name_index);
336
337 if (handler) {
338 size_t size = handler->list(dentry, buffer, rest,
339 entry->e_name,
340 entry->e_name_len,
341 handler->flags);
342 if (buffer) {
343 if (size > rest)
344 return -ERANGE;
345 buffer += size;
346 }
347 rest -= size;
348 }
349 }
350 return buffer_size - rest;
351}
352
353static int
354ext4_xattr_block_list(struct dentry *dentry, char *buffer, size_t buffer_size)
355{
356 struct inode *inode = dentry->d_inode;
357 struct buffer_head *bh = NULL;
358 int error;
359
360 ea_idebug(inode, "buffer=%p, buffer_size=%ld",
361 buffer, (long)buffer_size);
362
363 error = 0;
364 if (!EXT4_I(inode)->i_file_acl)
365 goto cleanup;
366 ea_idebug(inode, "reading block %u", EXT4_I(inode)->i_file_acl);
367 bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl);
368 error = -EIO;
369 if (!bh)
370 goto cleanup;
371 ea_bdebug(bh, "b_count=%d, refcount=%d",
372 atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount));
373 if (ext4_xattr_check_block(bh)) {
374 EXT4_ERROR_INODE(inode, "bad block %llu",
375 EXT4_I(inode)->i_file_acl);
376 error = -EIO;
377 goto cleanup;
378 }
379 ext4_xattr_cache_insert(bh);
380 error = ext4_xattr_list_entries(dentry, BFIRST(bh), buffer, buffer_size);
381
382cleanup:
383 brelse(bh);
384
385 return error;
386}
387
388static int
389ext4_xattr_ibody_list(struct dentry *dentry, char *buffer, size_t buffer_size)
390{
391 struct inode *inode = dentry->d_inode;
392 struct ext4_xattr_ibody_header *header;
393 struct ext4_inode *raw_inode;
394 struct ext4_iloc iloc;
395 void *end;
396 int error;
397
398 if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR))
399 return 0;
400 error = ext4_get_inode_loc(inode, &iloc);
401 if (error)
402 return error;
403 raw_inode = ext4_raw_inode(&iloc);
404 header = IHDR(inode, raw_inode);
405 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
406 error = ext4_xattr_check_names(IFIRST(header), end);
407 if (error)
408 goto cleanup;
409 error = ext4_xattr_list_entries(dentry, IFIRST(header),
410 buffer, buffer_size);
411
412cleanup:
413 brelse(iloc.bh);
414 return error;
415}
416
417/*
418 * ext4_xattr_list()
419 *
420 * Copy a list of attribute names into the buffer
421 * provided, or compute the buffer size required.
422 * Buffer is NULL to compute the size of the buffer required.
423 *
424 * Returns a negative error number on failure, or the number of bytes
425 * used / required on success.
426 */
427static int
428ext4_xattr_list(struct dentry *dentry, char *buffer, size_t buffer_size)
429{
430 int ret, ret2;
431
432 down_read(&EXT4_I(dentry->d_inode)->xattr_sem);
433 ret = ret2 = ext4_xattr_ibody_list(dentry, buffer, buffer_size);
434 if (ret < 0)
435 goto errout;
436 if (buffer) {
437 buffer += ret;
438 buffer_size -= ret;
439 }
440 ret = ext4_xattr_block_list(dentry, buffer, buffer_size);
441 if (ret < 0)
442 goto errout;
443 ret += ret2;
444errout:
445 up_read(&EXT4_I(dentry->d_inode)->xattr_sem);
446 return ret;
447}
448
449/*
450 * If the EXT4_FEATURE_COMPAT_EXT_ATTR feature of this file system is
451 * not set, set it.
452 */
453static void ext4_xattr_update_super_block(handle_t *handle,
454 struct super_block *sb)
455{
456 if (EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_EXT_ATTR))
457 return;
458
459 if (ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh) == 0) {
460 EXT4_SET_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_EXT_ATTR);
461 ext4_handle_dirty_super(handle, sb);
462 }
463}
464
465/*
466 * Release the xattr block BH: If the reference count is > 1, decrement
467 * it; otherwise free the block.
468 */
469static void
470ext4_xattr_release_block(handle_t *handle, struct inode *inode,
471 struct buffer_head *bh)
472{
473 struct mb_cache_entry *ce = NULL;
474 int error = 0;
475
476 ce = mb_cache_entry_get(ext4_xattr_cache, bh->b_bdev, bh->b_blocknr);
477 error = ext4_journal_get_write_access(handle, bh);
478 if (error)
479 goto out;
480
481 lock_buffer(bh);
482 if (BHDR(bh)->h_refcount == cpu_to_le32(1)) {
483 ea_bdebug(bh, "refcount now=0; freeing");
484 if (ce)
485 mb_cache_entry_free(ce);
486 get_bh(bh);
487 ext4_free_blocks(handle, inode, bh, 0, 1,
488 EXT4_FREE_BLOCKS_METADATA |
489 EXT4_FREE_BLOCKS_FORGET);
490 } else {
491 le32_add_cpu(&BHDR(bh)->h_refcount, -1);
492 error = ext4_handle_dirty_metadata(handle, inode, bh);
493 if (IS_SYNC(inode))
494 ext4_handle_sync(handle);
495 dquot_free_block(inode, 1);
496 ea_bdebug(bh, "refcount now=%d; releasing",
497 le32_to_cpu(BHDR(bh)->h_refcount));
498 if (ce)
499 mb_cache_entry_release(ce);
500 }
501 unlock_buffer(bh);
502out:
503 ext4_std_error(inode->i_sb, error);
504 return;
505}
506
507/*
508 * Find the available free space for EAs. This also returns the total number of
509 * bytes used by EA entries.
510 */
511static size_t ext4_xattr_free_space(struct ext4_xattr_entry *last,
512 size_t *min_offs, void *base, int *total)
513{
514 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
515 *total += EXT4_XATTR_LEN(last->e_name_len);
516 if (!last->e_value_block && last->e_value_size) {
517 size_t offs = le16_to_cpu(last->e_value_offs);
518 if (offs < *min_offs)
519 *min_offs = offs;
520 }
521 }
522 return (*min_offs - ((void *)last - base) - sizeof(__u32));
523}
524
525struct ext4_xattr_info {
526 int name_index;
527 const char *name;
528 const void *value;
529 size_t value_len;
530};
531
532struct ext4_xattr_search {
533 struct ext4_xattr_entry *first;
534 void *base;
535 void *end;
536 struct ext4_xattr_entry *here;
537 int not_found;
538};
539
540static int
541ext4_xattr_set_entry(struct ext4_xattr_info *i, struct ext4_xattr_search *s)
542{
543 struct ext4_xattr_entry *last;
544 size_t free, min_offs = s->end - s->base, name_len = strlen(i->name);
545
546 /* Compute min_offs and last. */
547 last = s->first;
548 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
549 if (!last->e_value_block && last->e_value_size) {
550 size_t offs = le16_to_cpu(last->e_value_offs);
551 if (offs < min_offs)
552 min_offs = offs;
553 }
554 }
555 free = min_offs - ((void *)last - s->base) - sizeof(__u32);
556 if (!s->not_found) {
557 if (!s->here->e_value_block && s->here->e_value_size) {
558 size_t size = le32_to_cpu(s->here->e_value_size);
559 free += EXT4_XATTR_SIZE(size);
560 }
561 free += EXT4_XATTR_LEN(name_len);
562 }
563 if (i->value) {
564 if (free < EXT4_XATTR_SIZE(i->value_len) ||
565 free < EXT4_XATTR_LEN(name_len) +
566 EXT4_XATTR_SIZE(i->value_len))
567 return -ENOSPC;
568 }
569
570 if (i->value && s->not_found) {
571 /* Insert the new name. */
572 size_t size = EXT4_XATTR_LEN(name_len);
573 size_t rest = (void *)last - (void *)s->here + sizeof(__u32);
574 memmove((void *)s->here + size, s->here, rest);
575 memset(s->here, 0, size);
576 s->here->e_name_index = i->name_index;
577 s->here->e_name_len = name_len;
578 memcpy(s->here->e_name, i->name, name_len);
579 } else {
580 if (!s->here->e_value_block && s->here->e_value_size) {
581 void *first_val = s->base + min_offs;
582 size_t offs = le16_to_cpu(s->here->e_value_offs);
583 void *val = s->base + offs;
584 size_t size = EXT4_XATTR_SIZE(
585 le32_to_cpu(s->here->e_value_size));
586
587 if (i->value && size == EXT4_XATTR_SIZE(i->value_len)) {
588 /* The old and the new value have the same
589 size. Just replace. */
590 s->here->e_value_size =
591 cpu_to_le32(i->value_len);
592 memset(val + size - EXT4_XATTR_PAD, 0,
593 EXT4_XATTR_PAD); /* Clear pad bytes. */
594 memcpy(val, i->value, i->value_len);
595 return 0;
596 }
597
598 /* Remove the old value. */
599 memmove(first_val + size, first_val, val - first_val);
600 memset(first_val, 0, size);
601 s->here->e_value_size = 0;
602 s->here->e_value_offs = 0;
603 min_offs += size;
604
605 /* Adjust all value offsets. */
606 last = s->first;
607 while (!IS_LAST_ENTRY(last)) {
608 size_t o = le16_to_cpu(last->e_value_offs);
609 if (!last->e_value_block &&
610 last->e_value_size && o < offs)
611 last->e_value_offs =
612 cpu_to_le16(o + size);
613 last = EXT4_XATTR_NEXT(last);
614 }
615 }
616 if (!i->value) {
617 /* Remove the old name. */
618 size_t size = EXT4_XATTR_LEN(name_len);
619 last = ENTRY((void *)last - size);
620 memmove(s->here, (void *)s->here + size,
621 (void *)last - (void *)s->here + sizeof(__u32));
622 memset(last, 0, size);
623 }
624 }
625
626 if (i->value) {
627 /* Insert the new value. */
628 s->here->e_value_size = cpu_to_le32(i->value_len);
629 if (i->value_len) {
630 size_t size = EXT4_XATTR_SIZE(i->value_len);
631 void *val = s->base + min_offs - size;
632 s->here->e_value_offs = cpu_to_le16(min_offs - size);
633 memset(val + size - EXT4_XATTR_PAD, 0,
634 EXT4_XATTR_PAD); /* Clear the pad bytes. */
635 memcpy(val, i->value, i->value_len);
636 }
637 }
638 return 0;
639}
640
641struct ext4_xattr_block_find {
642 struct ext4_xattr_search s;
643 struct buffer_head *bh;
644};
645
646static int
647ext4_xattr_block_find(struct inode *inode, struct ext4_xattr_info *i,
648 struct ext4_xattr_block_find *bs)
649{
650 struct super_block *sb = inode->i_sb;
651 int error;
652
653 ea_idebug(inode, "name=%d.%s, value=%p, value_len=%ld",
654 i->name_index, i->name, i->value, (long)i->value_len);
655
656 if (EXT4_I(inode)->i_file_acl) {
657 /* The inode already has an extended attribute block. */
658 bs->bh = sb_bread(sb, EXT4_I(inode)->i_file_acl);
659 error = -EIO;
660 if (!bs->bh)
661 goto cleanup;
662 ea_bdebug(bs->bh, "b_count=%d, refcount=%d",
663 atomic_read(&(bs->bh->b_count)),
664 le32_to_cpu(BHDR(bs->bh)->h_refcount));
665 if (ext4_xattr_check_block(bs->bh)) {
666 EXT4_ERROR_INODE(inode, "bad block %llu",
667 EXT4_I(inode)->i_file_acl);
668 error = -EIO;
669 goto cleanup;
670 }
671 /* Find the named attribute. */
672 bs->s.base = BHDR(bs->bh);
673 bs->s.first = BFIRST(bs->bh);
674 bs->s.end = bs->bh->b_data + bs->bh->b_size;
675 bs->s.here = bs->s.first;
676 error = ext4_xattr_find_entry(&bs->s.here, i->name_index,
677 i->name, bs->bh->b_size, 1);
678 if (error && error != -ENODATA)
679 goto cleanup;
680 bs->s.not_found = error;
681 }
682 error = 0;
683
684cleanup:
685 return error;
686}
687
688static int
689ext4_xattr_block_set(handle_t *handle, struct inode *inode,
690 struct ext4_xattr_info *i,
691 struct ext4_xattr_block_find *bs)
692{
693 struct super_block *sb = inode->i_sb;
694 struct buffer_head *new_bh = NULL;
695 struct ext4_xattr_search *s = &bs->s;
696 struct mb_cache_entry *ce = NULL;
697 int error = 0;
698
699#define header(x) ((struct ext4_xattr_header *)(x))
700
701 if (i->value && i->value_len > sb->s_blocksize)
702 return -ENOSPC;
703 if (s->base) {
704 ce = mb_cache_entry_get(ext4_xattr_cache, bs->bh->b_bdev,
705 bs->bh->b_blocknr);
706 error = ext4_journal_get_write_access(handle, bs->bh);
707 if (error)
708 goto cleanup;
709 lock_buffer(bs->bh);
710
711 if (header(s->base)->h_refcount == cpu_to_le32(1)) {
712 if (ce) {
713 mb_cache_entry_free(ce);
714 ce = NULL;
715 }
716 ea_bdebug(bs->bh, "modifying in-place");
717 error = ext4_xattr_set_entry(i, s);
718 if (!error) {
719 if (!IS_LAST_ENTRY(s->first))
720 ext4_xattr_rehash(header(s->base),
721 s->here);
722 ext4_xattr_cache_insert(bs->bh);
723 }
724 unlock_buffer(bs->bh);
725 if (error == -EIO)
726 goto bad_block;
727 if (!error)
728 error = ext4_handle_dirty_metadata(handle,
729 inode,
730 bs->bh);
731 if (error)
732 goto cleanup;
733 goto inserted;
734 } else {
735 int offset = (char *)s->here - bs->bh->b_data;
736
737 unlock_buffer(bs->bh);
738 ext4_handle_release_buffer(handle, bs->bh);
739 if (ce) {
740 mb_cache_entry_release(ce);
741 ce = NULL;
742 }
743 ea_bdebug(bs->bh, "cloning");
744 s->base = kmalloc(bs->bh->b_size, GFP_NOFS);
745 error = -ENOMEM;
746 if (s->base == NULL)
747 goto cleanup;
748 memcpy(s->base, BHDR(bs->bh), bs->bh->b_size);
749 s->first = ENTRY(header(s->base)+1);
750 header(s->base)->h_refcount = cpu_to_le32(1);
751 s->here = ENTRY(s->base + offset);
752 s->end = s->base + bs->bh->b_size;
753 }
754 } else {
755 /* Allocate a buffer where we construct the new block. */
756 s->base = kzalloc(sb->s_blocksize, GFP_NOFS);
757 /* assert(header == s->base) */
758 error = -ENOMEM;
759 if (s->base == NULL)
760 goto cleanup;
761 header(s->base)->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
762 header(s->base)->h_blocks = cpu_to_le32(1);
763 header(s->base)->h_refcount = cpu_to_le32(1);
764 s->first = ENTRY(header(s->base)+1);
765 s->here = ENTRY(header(s->base)+1);
766 s->end = s->base + sb->s_blocksize;
767 }
768
769 error = ext4_xattr_set_entry(i, s);
770 if (error == -EIO)
771 goto bad_block;
772 if (error)
773 goto cleanup;
774 if (!IS_LAST_ENTRY(s->first))
775 ext4_xattr_rehash(header(s->base), s->here);
776
777inserted:
778 if (!IS_LAST_ENTRY(s->first)) {
779 new_bh = ext4_xattr_cache_find(inode, header(s->base), &ce);
780 if (new_bh) {
781 /* We found an identical block in the cache. */
782 if (new_bh == bs->bh)
783 ea_bdebug(new_bh, "keeping");
784 else {
785 /* The old block is released after updating
786 the inode. */
787 error = dquot_alloc_block(inode, 1);
788 if (error)
789 goto cleanup;
790 error = ext4_journal_get_write_access(handle,
791 new_bh);
792 if (error)
793 goto cleanup_dquot;
794 lock_buffer(new_bh);
795 le32_add_cpu(&BHDR(new_bh)->h_refcount, 1);
796 ea_bdebug(new_bh, "reusing; refcount now=%d",
797 le32_to_cpu(BHDR(new_bh)->h_refcount));
798 unlock_buffer(new_bh);
799 error = ext4_handle_dirty_metadata(handle,
800 inode,
801 new_bh);
802 if (error)
803 goto cleanup_dquot;
804 }
805 mb_cache_entry_release(ce);
806 ce = NULL;
807 } else if (bs->bh && s->base == bs->bh->b_data) {
808 /* We were modifying this block in-place. */
809 ea_bdebug(bs->bh, "keeping this block");
810 new_bh = bs->bh;
811 get_bh(new_bh);
812 } else {
813 /* We need to allocate a new block */
814 ext4_fsblk_t goal, block;
815
816 goal = ext4_group_first_block_no(sb,
817 EXT4_I(inode)->i_block_group);
818
819 /* non-extent files can't have physical blocks past 2^32 */
820 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
821 goal = goal & EXT4_MAX_BLOCK_FILE_PHYS;
822
823 block = ext4_new_meta_blocks(handle, inode, goal, 0,
824 NULL, &error);
825 if (error)
826 goto cleanup;
827
828 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
829 BUG_ON(block > EXT4_MAX_BLOCK_FILE_PHYS);
830
831 ea_idebug(inode, "creating block %d", block);
832
833 new_bh = sb_getblk(sb, block);
834 if (!new_bh) {
835getblk_failed:
836 ext4_free_blocks(handle, inode, NULL, block, 1,
837 EXT4_FREE_BLOCKS_METADATA);
838 error = -EIO;
839 goto cleanup;
840 }
841 lock_buffer(new_bh);
842 error = ext4_journal_get_create_access(handle, new_bh);
843 if (error) {
844 unlock_buffer(new_bh);
845 goto getblk_failed;
846 }
847 memcpy(new_bh->b_data, s->base, new_bh->b_size);
848 set_buffer_uptodate(new_bh);
849 unlock_buffer(new_bh);
850 ext4_xattr_cache_insert(new_bh);
851 error = ext4_handle_dirty_metadata(handle,
852 inode, new_bh);
853 if (error)
854 goto cleanup;
855 }
856 }
857
858 /* Update the inode. */
859 EXT4_I(inode)->i_file_acl = new_bh ? new_bh->b_blocknr : 0;
860
861 /* Drop the previous xattr block. */
862 if (bs->bh && bs->bh != new_bh)
863 ext4_xattr_release_block(handle, inode, bs->bh);
864 error = 0;
865
866cleanup:
867 if (ce)
868 mb_cache_entry_release(ce);
869 brelse(new_bh);
870 if (!(bs->bh && s->base == bs->bh->b_data))
871 kfree(s->base);
872
873 return error;
874
875cleanup_dquot:
876 dquot_free_block(inode, 1);
877 goto cleanup;
878
879bad_block:
880 EXT4_ERROR_INODE(inode, "bad block %llu",
881 EXT4_I(inode)->i_file_acl);
882 goto cleanup;
883
884#undef header
885}
886
887struct ext4_xattr_ibody_find {
888 struct ext4_xattr_search s;
889 struct ext4_iloc iloc;
890};
891
892static int
893ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i,
894 struct ext4_xattr_ibody_find *is)
895{
896 struct ext4_xattr_ibody_header *header;
897 struct ext4_inode *raw_inode;
898 int error;
899
900 if (EXT4_I(inode)->i_extra_isize == 0)
901 return 0;
902 raw_inode = ext4_raw_inode(&is->iloc);
903 header = IHDR(inode, raw_inode);
904 is->s.base = is->s.first = IFIRST(header);
905 is->s.here = is->s.first;
906 is->s.end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
907 if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
908 error = ext4_xattr_check_names(IFIRST(header), is->s.end);
909 if (error)
910 return error;
911 /* Find the named attribute. */
912 error = ext4_xattr_find_entry(&is->s.here, i->name_index,
913 i->name, is->s.end -
914 (void *)is->s.base, 0);
915 if (error && error != -ENODATA)
916 return error;
917 is->s.not_found = error;
918 }
919 return 0;
920}
921
922static int
923ext4_xattr_ibody_set(handle_t *handle, struct inode *inode,
924 struct ext4_xattr_info *i,
925 struct ext4_xattr_ibody_find *is)
926{
927 struct ext4_xattr_ibody_header *header;
928 struct ext4_xattr_search *s = &is->s;
929 int error;
930
931 if (EXT4_I(inode)->i_extra_isize == 0)
932 return -ENOSPC;
933 error = ext4_xattr_set_entry(i, s);
934 if (error)
935 return error;
936 header = IHDR(inode, ext4_raw_inode(&is->iloc));
937 if (!IS_LAST_ENTRY(s->first)) {
938 header->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
939 ext4_set_inode_state(inode, EXT4_STATE_XATTR);
940 } else {
941 header->h_magic = cpu_to_le32(0);
942 ext4_clear_inode_state(inode, EXT4_STATE_XATTR);
943 }
944 return 0;
945}
946
947/*
948 * ext4_xattr_set_handle()
949 *
950 * Create, replace or remove an extended attribute for this inode. Value
951 * is NULL to remove an existing extended attribute, and non-NULL to
952 * either replace an existing extended attribute, or create a new extended
953 * attribute. The flags XATTR_REPLACE and XATTR_CREATE
954 * specify that an extended attribute must exist and must not exist
955 * previous to the call, respectively.
956 *
957 * Returns 0, or a negative error number on failure.
958 */
959int
960ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
961 const char *name, const void *value, size_t value_len,
962 int flags)
963{
964 struct ext4_xattr_info i = {
965 .name_index = name_index,
966 .name = name,
967 .value = value,
968 .value_len = value_len,
969
970 };
971 struct ext4_xattr_ibody_find is = {
972 .s = { .not_found = -ENODATA, },
973 };
974 struct ext4_xattr_block_find bs = {
975 .s = { .not_found = -ENODATA, },
976 };
977 unsigned long no_expand;
978 int error;
979
980 if (!name)
981 return -EINVAL;
982 if (strlen(name) > 255)
983 return -ERANGE;
984 down_write(&EXT4_I(inode)->xattr_sem);
985 no_expand = ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND);
986 ext4_set_inode_state(inode, EXT4_STATE_NO_EXPAND);
987
988 error = ext4_get_inode_loc(inode, &is.iloc);
989 if (error)
990 goto cleanup;
991
992 error = ext4_journal_get_write_access(handle, is.iloc.bh);
993 if (error)
994 goto cleanup;
995
996 if (ext4_test_inode_state(inode, EXT4_STATE_NEW)) {
997 struct ext4_inode *raw_inode = ext4_raw_inode(&is.iloc);
998 memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size);
999 ext4_clear_inode_state(inode, EXT4_STATE_NEW);
1000 }
1001
1002 error = ext4_xattr_ibody_find(inode, &i, &is);
1003 if (error)
1004 goto cleanup;
1005 if (is.s.not_found)
1006 error = ext4_xattr_block_find(inode, &i, &bs);
1007 if (error)
1008 goto cleanup;
1009 if (is.s.not_found && bs.s.not_found) {
1010 error = -ENODATA;
1011 if (flags & XATTR_REPLACE)
1012 goto cleanup;
1013 error = 0;
1014 if (!value)
1015 goto cleanup;
1016 } else {
1017 error = -EEXIST;
1018 if (flags & XATTR_CREATE)
1019 goto cleanup;
1020 }
1021 if (!value) {
1022 if (!is.s.not_found)
1023 error = ext4_xattr_ibody_set(handle, inode, &i, &is);
1024 else if (!bs.s.not_found)
1025 error = ext4_xattr_block_set(handle, inode, &i, &bs);
1026 } else {
1027 error = ext4_xattr_ibody_set(handle, inode, &i, &is);
1028 if (!error && !bs.s.not_found) {
1029 i.value = NULL;
1030 error = ext4_xattr_block_set(handle, inode, &i, &bs);
1031 } else if (error == -ENOSPC) {
1032 if (EXT4_I(inode)->i_file_acl && !bs.s.base) {
1033 error = ext4_xattr_block_find(inode, &i, &bs);
1034 if (error)
1035 goto cleanup;
1036 }
1037 error = ext4_xattr_block_set(handle, inode, &i, &bs);
1038 if (error)
1039 goto cleanup;
1040 if (!is.s.not_found) {
1041 i.value = NULL;
1042 error = ext4_xattr_ibody_set(handle, inode, &i,
1043 &is);
1044 }
1045 }
1046 }
1047 if (!error) {
1048 ext4_xattr_update_super_block(handle, inode->i_sb);
1049 inode->i_ctime = ext4_current_time(inode);
1050 if (!value)
1051 ext4_clear_inode_state(inode, EXT4_STATE_NO_EXPAND);
1052 error = ext4_mark_iloc_dirty(handle, inode, &is.iloc);
1053 /*
1054 * The bh is consumed by ext4_mark_iloc_dirty, even with
1055 * error != 0.
1056 */
1057 is.iloc.bh = NULL;
1058 if (IS_SYNC(inode))
1059 ext4_handle_sync(handle);
1060 }
1061
1062cleanup:
1063 brelse(is.iloc.bh);
1064 brelse(bs.bh);
1065 if (no_expand == 0)
1066 ext4_clear_inode_state(inode, EXT4_STATE_NO_EXPAND);
1067 up_write(&EXT4_I(inode)->xattr_sem);
1068 return error;
1069}
1070
1071/*
1072 * ext4_xattr_set()
1073 *
1074 * Like ext4_xattr_set_handle, but start from an inode. This extended
1075 * attribute modification is a filesystem transaction by itself.
1076 *
1077 * Returns 0, or a negative error number on failure.
1078 */
1079int
1080ext4_xattr_set(struct inode *inode, int name_index, const char *name,
1081 const void *value, size_t value_len, int flags)
1082{
1083 handle_t *handle;
1084 int error, retries = 0;
1085
1086retry:
1087 handle = ext4_journal_start(inode, EXT4_DATA_TRANS_BLOCKS(inode->i_sb));
1088 if (IS_ERR(handle)) {
1089 error = PTR_ERR(handle);
1090 } else {
1091 int error2;
1092
1093 error = ext4_xattr_set_handle(handle, inode, name_index, name,
1094 value, value_len, flags);
1095 error2 = ext4_journal_stop(handle);
1096 if (error == -ENOSPC &&
1097 ext4_should_retry_alloc(inode->i_sb, &retries))
1098 goto retry;
1099 if (error == 0)
1100 error = error2;
1101 }
1102
1103 return error;
1104}
1105
1106/*
1107 * Shift the EA entries in the inode to create space for the increased
1108 * i_extra_isize.
1109 */
1110static void ext4_xattr_shift_entries(struct ext4_xattr_entry *entry,
1111 int value_offs_shift, void *to,
1112 void *from, size_t n, int blocksize)
1113{
1114 struct ext4_xattr_entry *last = entry;
1115 int new_offs;
1116
1117 /* Adjust the value offsets of the entries */
1118 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
1119 if (!last->e_value_block && last->e_value_size) {
1120 new_offs = le16_to_cpu(last->e_value_offs) +
1121 value_offs_shift;
1122 BUG_ON(new_offs + le32_to_cpu(last->e_value_size)
1123 > blocksize);
1124 last->e_value_offs = cpu_to_le16(new_offs);
1125 }
1126 }
1127 /* Shift the entries by n bytes */
1128 memmove(to, from, n);
1129}
1130
1131/*
1132 * Expand an inode by new_extra_isize bytes when EAs are present.
1133 * Returns 0 on success or negative error number on failure.
1134 */
1135int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
1136 struct ext4_inode *raw_inode, handle_t *handle)
1137{
1138 struct ext4_xattr_ibody_header *header;
1139 struct ext4_xattr_entry *entry, *last, *first;
1140 struct buffer_head *bh = NULL;
1141 struct ext4_xattr_ibody_find *is = NULL;
1142 struct ext4_xattr_block_find *bs = NULL;
1143 char *buffer = NULL, *b_entry_name = NULL;
1144 size_t min_offs, free;
1145 int total_ino, total_blk;
1146 void *base, *start, *end;
1147 int extra_isize = 0, error = 0, tried_min_extra_isize = 0;
1148 int s_min_extra_isize = le16_to_cpu(EXT4_SB(inode->i_sb)->s_es->s_min_extra_isize);
1149
1150 down_write(&EXT4_I(inode)->xattr_sem);
1151retry:
1152 if (EXT4_I(inode)->i_extra_isize >= new_extra_isize) {
1153 up_write(&EXT4_I(inode)->xattr_sem);
1154 return 0;
1155 }
1156
1157 header = IHDR(inode, raw_inode);
1158 entry = IFIRST(header);
1159
1160 /*
1161 * Check if enough free space is available in the inode to shift the
1162 * entries ahead by new_extra_isize.
1163 */
1164
1165 base = start = entry;
1166 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
1167 min_offs = end - base;
1168 last = entry;
1169 total_ino = sizeof(struct ext4_xattr_ibody_header);
1170
1171 free = ext4_xattr_free_space(last, &min_offs, base, &total_ino);
1172 if (free >= new_extra_isize) {
1173 entry = IFIRST(header);
1174 ext4_xattr_shift_entries(entry, EXT4_I(inode)->i_extra_isize
1175 - new_extra_isize, (void *)raw_inode +
1176 EXT4_GOOD_OLD_INODE_SIZE + new_extra_isize,
1177 (void *)header, total_ino,
1178 inode->i_sb->s_blocksize);
1179 EXT4_I(inode)->i_extra_isize = new_extra_isize;
1180 error = 0;
1181 goto cleanup;
1182 }
1183
1184 /*
1185 * Enough free space isn't available in the inode, check if
1186 * EA block can hold new_extra_isize bytes.
1187 */
1188 if (EXT4_I(inode)->i_file_acl) {
1189 bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl);
1190 error = -EIO;
1191 if (!bh)
1192 goto cleanup;
1193 if (ext4_xattr_check_block(bh)) {
1194 EXT4_ERROR_INODE(inode, "bad block %llu",
1195 EXT4_I(inode)->i_file_acl);
1196 error = -EIO;
1197 goto cleanup;
1198 }
1199 base = BHDR(bh);
1200 first = BFIRST(bh);
1201 end = bh->b_data + bh->b_size;
1202 min_offs = end - base;
1203 free = ext4_xattr_free_space(first, &min_offs, base,
1204 &total_blk);
1205 if (free < new_extra_isize) {
1206 if (!tried_min_extra_isize && s_min_extra_isize) {
1207 tried_min_extra_isize++;
1208 new_extra_isize = s_min_extra_isize;
1209 brelse(bh);
1210 goto retry;
1211 }
1212 error = -1;
1213 goto cleanup;
1214 }
1215 } else {
1216 free = inode->i_sb->s_blocksize;
1217 }
1218
1219 while (new_extra_isize > 0) {
1220 size_t offs, size, entry_size;
1221 struct ext4_xattr_entry *small_entry = NULL;
1222 struct ext4_xattr_info i = {
1223 .value = NULL,
1224 .value_len = 0,
1225 };
1226 unsigned int total_size; /* EA entry size + value size */
1227 unsigned int shift_bytes; /* No. of bytes to shift EAs by? */
1228 unsigned int min_total_size = ~0U;
1229
1230 is = kzalloc(sizeof(struct ext4_xattr_ibody_find), GFP_NOFS);
1231 bs = kzalloc(sizeof(struct ext4_xattr_block_find), GFP_NOFS);
1232 if (!is || !bs) {
1233 error = -ENOMEM;
1234 goto cleanup;
1235 }
1236
1237 is->s.not_found = -ENODATA;
1238 bs->s.not_found = -ENODATA;
1239 is->iloc.bh = NULL;
1240 bs->bh = NULL;
1241
1242 last = IFIRST(header);
1243 /* Find the entry best suited to be pushed into EA block */
1244 entry = NULL;
1245 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
1246 total_size =
1247 EXT4_XATTR_SIZE(le32_to_cpu(last->e_value_size)) +
1248 EXT4_XATTR_LEN(last->e_name_len);
1249 if (total_size <= free && total_size < min_total_size) {
1250 if (total_size < new_extra_isize) {
1251 small_entry = last;
1252 } else {
1253 entry = last;
1254 min_total_size = total_size;
1255 }
1256 }
1257 }
1258
1259 if (entry == NULL) {
1260 if (small_entry) {
1261 entry = small_entry;
1262 } else {
1263 if (!tried_min_extra_isize &&
1264 s_min_extra_isize) {
1265 tried_min_extra_isize++;
1266 new_extra_isize = s_min_extra_isize;
1267 goto retry;
1268 }
1269 error = -1;
1270 goto cleanup;
1271 }
1272 }
1273 offs = le16_to_cpu(entry->e_value_offs);
1274 size = le32_to_cpu(entry->e_value_size);
1275 entry_size = EXT4_XATTR_LEN(entry->e_name_len);
1276 i.name_index = entry->e_name_index,
1277 buffer = kmalloc(EXT4_XATTR_SIZE(size), GFP_NOFS);
1278 b_entry_name = kmalloc(entry->e_name_len + 1, GFP_NOFS);
1279 if (!buffer || !b_entry_name) {
1280 error = -ENOMEM;
1281 goto cleanup;
1282 }
1283 /* Save the entry name and the entry value */
1284 memcpy(buffer, (void *)IFIRST(header) + offs,
1285 EXT4_XATTR_SIZE(size));
1286 memcpy(b_entry_name, entry->e_name, entry->e_name_len);
1287 b_entry_name[entry->e_name_len] = '\0';
1288 i.name = b_entry_name;
1289
1290 error = ext4_get_inode_loc(inode, &is->iloc);
1291 if (error)
1292 goto cleanup;
1293
1294 error = ext4_xattr_ibody_find(inode, &i, is);
1295 if (error)
1296 goto cleanup;
1297
1298 /* Remove the chosen entry from the inode */
1299 error = ext4_xattr_ibody_set(handle, inode, &i, is);
1300 if (error)
1301 goto cleanup;
1302
1303 entry = IFIRST(header);
1304 if (entry_size + EXT4_XATTR_SIZE(size) >= new_extra_isize)
1305 shift_bytes = new_extra_isize;
1306 else
1307 shift_bytes = entry_size + size;
1308 /* Adjust the offsets and shift the remaining entries ahead */
1309 ext4_xattr_shift_entries(entry, EXT4_I(inode)->i_extra_isize -
1310 shift_bytes, (void *)raw_inode +
1311 EXT4_GOOD_OLD_INODE_SIZE + extra_isize + shift_bytes,
1312 (void *)header, total_ino - entry_size,
1313 inode->i_sb->s_blocksize);
1314
1315 extra_isize += shift_bytes;
1316 new_extra_isize -= shift_bytes;
1317 EXT4_I(inode)->i_extra_isize = extra_isize;
1318
1319 i.name = b_entry_name;
1320 i.value = buffer;
1321 i.value_len = size;
1322 error = ext4_xattr_block_find(inode, &i, bs);
1323 if (error)
1324 goto cleanup;
1325
1326 /* Add entry which was removed from the inode into the block */
1327 error = ext4_xattr_block_set(handle, inode, &i, bs);
1328 if (error)
1329 goto cleanup;
1330 kfree(b_entry_name);
1331 kfree(buffer);
1332 b_entry_name = NULL;
1333 buffer = NULL;
1334 brelse(is->iloc.bh);
1335 kfree(is);
1336 kfree(bs);
1337 }
1338 brelse(bh);
1339 up_write(&EXT4_I(inode)->xattr_sem);
1340 return 0;
1341
1342cleanup:
1343 kfree(b_entry_name);
1344 kfree(buffer);
1345 if (is)
1346 brelse(is->iloc.bh);
1347 kfree(is);
1348 kfree(bs);
1349 brelse(bh);
1350 up_write(&EXT4_I(inode)->xattr_sem);
1351 return error;
1352}
1353
1354
1355
1356/*
1357 * ext4_xattr_delete_inode()
1358 *
1359 * Free extended attribute resources associated with this inode. This
1360 * is called immediately before an inode is freed. We have exclusive
1361 * access to the inode.
1362 */
1363void
1364ext4_xattr_delete_inode(handle_t *handle, struct inode *inode)
1365{
1366 struct buffer_head *bh = NULL;
1367
1368 if (!EXT4_I(inode)->i_file_acl)
1369 goto cleanup;
1370 bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl);
1371 if (!bh) {
1372 EXT4_ERROR_INODE(inode, "block %llu read error",
1373 EXT4_I(inode)->i_file_acl);
1374 goto cleanup;
1375 }
1376 if (BHDR(bh)->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC) ||
1377 BHDR(bh)->h_blocks != cpu_to_le32(1)) {
1378 EXT4_ERROR_INODE(inode, "bad block %llu",
1379 EXT4_I(inode)->i_file_acl);
1380 goto cleanup;
1381 }
1382 ext4_xattr_release_block(handle, inode, bh);
1383 EXT4_I(inode)->i_file_acl = 0;
1384
1385cleanup:
1386 brelse(bh);
1387}
1388
1389/*
1390 * ext4_xattr_put_super()
1391 *
1392 * This is called when a file system is unmounted.
1393 */
1394void
1395ext4_xattr_put_super(struct super_block *sb)
1396{
1397 mb_cache_shrink(sb->s_bdev);
1398}
1399
1400/*
1401 * ext4_xattr_cache_insert()
1402 *
1403 * Create a new entry in the extended attribute cache, and insert
1404 * it unless such an entry is already in the cache.
1405 *
1406 * Returns 0, or a negative error number on failure.
1407 */
1408static void
1409ext4_xattr_cache_insert(struct buffer_head *bh)
1410{
1411 __u32 hash = le32_to_cpu(BHDR(bh)->h_hash);
1412 struct mb_cache_entry *ce;
1413 int error;
1414
1415 ce = mb_cache_entry_alloc(ext4_xattr_cache, GFP_NOFS);
1416 if (!ce) {
1417 ea_bdebug(bh, "out of memory");
1418 return;
1419 }
1420 error = mb_cache_entry_insert(ce, bh->b_bdev, bh->b_blocknr, hash);
1421 if (error) {
1422 mb_cache_entry_free(ce);
1423 if (error == -EBUSY) {
1424 ea_bdebug(bh, "already in cache");
1425 error = 0;
1426 }
1427 } else {
1428 ea_bdebug(bh, "inserting [%x]", (int)hash);
1429 mb_cache_entry_release(ce);
1430 }
1431}
1432
1433/*
1434 * ext4_xattr_cmp()
1435 *
1436 * Compare two extended attribute blocks for equality.
1437 *
1438 * Returns 0 if the blocks are equal, 1 if they differ, and
1439 * a negative error number on errors.
1440 */
1441static int
1442ext4_xattr_cmp(struct ext4_xattr_header *header1,
1443 struct ext4_xattr_header *header2)
1444{
1445 struct ext4_xattr_entry *entry1, *entry2;
1446
1447 entry1 = ENTRY(header1+1);
1448 entry2 = ENTRY(header2+1);
1449 while (!IS_LAST_ENTRY(entry1)) {
1450 if (IS_LAST_ENTRY(entry2))
1451 return 1;
1452 if (entry1->e_hash != entry2->e_hash ||
1453 entry1->e_name_index != entry2->e_name_index ||
1454 entry1->e_name_len != entry2->e_name_len ||
1455 entry1->e_value_size != entry2->e_value_size ||
1456 memcmp(entry1->e_name, entry2->e_name, entry1->e_name_len))
1457 return 1;
1458 if (entry1->e_value_block != 0 || entry2->e_value_block != 0)
1459 return -EIO;
1460 if (memcmp((char *)header1 + le16_to_cpu(entry1->e_value_offs),
1461 (char *)header2 + le16_to_cpu(entry2->e_value_offs),
1462 le32_to_cpu(entry1->e_value_size)))
1463 return 1;
1464
1465 entry1 = EXT4_XATTR_NEXT(entry1);
1466 entry2 = EXT4_XATTR_NEXT(entry2);
1467 }
1468 if (!IS_LAST_ENTRY(entry2))
1469 return 1;
1470 return 0;
1471}
1472
1473/*
1474 * ext4_xattr_cache_find()
1475 *
1476 * Find an identical extended attribute block.
1477 *
1478 * Returns a pointer to the block found, or NULL if such a block was
1479 * not found or an error occurred.
1480 */
1481static struct buffer_head *
1482ext4_xattr_cache_find(struct inode *inode, struct ext4_xattr_header *header,
1483 struct mb_cache_entry **pce)
1484{
1485 __u32 hash = le32_to_cpu(header->h_hash);
1486 struct mb_cache_entry *ce;
1487
1488 if (!header->h_hash)
1489 return NULL; /* never share */
1490 ea_idebug(inode, "looking for cached blocks [%x]", (int)hash);
1491again:
1492 ce = mb_cache_entry_find_first(ext4_xattr_cache, inode->i_sb->s_bdev,
1493 hash);
1494 while (ce) {
1495 struct buffer_head *bh;
1496
1497 if (IS_ERR(ce)) {
1498 if (PTR_ERR(ce) == -EAGAIN)
1499 goto again;
1500 break;
1501 }
1502 bh = sb_bread(inode->i_sb, ce->e_block);
1503 if (!bh) {
1504 EXT4_ERROR_INODE(inode, "block %lu read error",
1505 (unsigned long) ce->e_block);
1506 } else if (le32_to_cpu(BHDR(bh)->h_refcount) >=
1507 EXT4_XATTR_REFCOUNT_MAX) {
1508 ea_idebug(inode, "block %lu refcount %d>=%d",
1509 (unsigned long) ce->e_block,
1510 le32_to_cpu(BHDR(bh)->h_refcount),
1511 EXT4_XATTR_REFCOUNT_MAX);
1512 } else if (ext4_xattr_cmp(header, BHDR(bh)) == 0) {
1513 *pce = ce;
1514 return bh;
1515 }
1516 brelse(bh);
1517 ce = mb_cache_entry_find_next(ce, inode->i_sb->s_bdev, hash);
1518 }
1519 return NULL;
1520}
1521
1522#define NAME_HASH_SHIFT 5
1523#define VALUE_HASH_SHIFT 16
1524
1525/*
1526 * ext4_xattr_hash_entry()
1527 *
1528 * Compute the hash of an extended attribute.
1529 */
1530static inline void ext4_xattr_hash_entry(struct ext4_xattr_header *header,
1531 struct ext4_xattr_entry *entry)
1532{
1533 __u32 hash = 0;
1534 char *name = entry->e_name;
1535 int n;
1536
1537 for (n = 0; n < entry->e_name_len; n++) {
1538 hash = (hash << NAME_HASH_SHIFT) ^
1539 (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^
1540 *name++;
1541 }
1542
1543 if (entry->e_value_block == 0 && entry->e_value_size != 0) {
1544 __le32 *value = (__le32 *)((char *)header +
1545 le16_to_cpu(entry->e_value_offs));
1546 for (n = (le32_to_cpu(entry->e_value_size) +
1547 EXT4_XATTR_ROUND) >> EXT4_XATTR_PAD_BITS; n; n--) {
1548 hash = (hash << VALUE_HASH_SHIFT) ^
1549 (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^
1550 le32_to_cpu(*value++);
1551 }
1552 }
1553 entry->e_hash = cpu_to_le32(hash);
1554}
1555
1556#undef NAME_HASH_SHIFT
1557#undef VALUE_HASH_SHIFT
1558
1559#define BLOCK_HASH_SHIFT 16
1560
1561/*
1562 * ext4_xattr_rehash()
1563 *
1564 * Re-compute the extended attribute hash value after an entry has changed.
1565 */
1566static void ext4_xattr_rehash(struct ext4_xattr_header *header,
1567 struct ext4_xattr_entry *entry)
1568{
1569 struct ext4_xattr_entry *here;
1570 __u32 hash = 0;
1571
1572 ext4_xattr_hash_entry(header, entry);
1573 here = ENTRY(header+1);
1574 while (!IS_LAST_ENTRY(here)) {
1575 if (!here->e_hash) {
1576 /* Block is not shared if an entry's hash value == 0 */
1577 hash = 0;
1578 break;
1579 }
1580 hash = (hash << BLOCK_HASH_SHIFT) ^
1581 (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^
1582 le32_to_cpu(here->e_hash);
1583 here = EXT4_XATTR_NEXT(here);
1584 }
1585 header->h_hash = cpu_to_le32(hash);
1586}
1587
1588#undef BLOCK_HASH_SHIFT
1589
1590int __init
1591ext4_init_xattr(void)
1592{
1593 ext4_xattr_cache = mb_cache_create("ext4_xattr", 6);
1594 if (!ext4_xattr_cache)
1595 return -ENOMEM;
1596 return 0;
1597}
1598
1599void
1600ext4_exit_xattr(void)
1601{
1602 if (ext4_xattr_cache)
1603 mb_cache_destroy(ext4_xattr_cache);
1604 ext4_xattr_cache = NULL;
1605}
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 int ext4_xattr_inode_lookup_create(handle_t *handle, struct inode *inode,
1569 const void *value, size_t value_len,
1570 struct inode **ret_inode)
1571{
1572 struct inode *ea_inode;
1573 u32 hash;
1574 int err;
1575
1576 hash = ext4_xattr_inode_hash(EXT4_SB(inode->i_sb), value, value_len);
1577 ea_inode = ext4_xattr_inode_cache_find(inode, value, value_len, hash);
1578 if (ea_inode) {
1579 err = ext4_xattr_inode_inc_ref(handle, ea_inode);
1580 if (err) {
1581 iput(ea_inode);
1582 return err;
1583 }
1584
1585 *ret_inode = ea_inode;
1586 return 0;
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 return PTR_ERR(ea_inode);
1593
1594 err = ext4_xattr_inode_write(handle, ea_inode, value, value_len);
1595 if (err) {
1596 if (ext4_xattr_inode_dec_ref(handle, ea_inode))
1597 ext4_warning_inode(ea_inode, "cleanup dec ref error %d", err);
1598 iput(ea_inode);
1599 return err;
1600 }
1601
1602 if (EA_INODE_CACHE(inode))
1603 mb_cache_entry_create(EA_INODE_CACHE(inode), GFP_NOFS, hash,
1604 ea_inode->i_ino, true /* reusable */);
1605
1606 *ret_inode = ea_inode;
1607 return 0;
1608}
1609
1610/*
1611 * Reserve min(block_size/8, 1024) bytes for xattr entries/names if ea_inode
1612 * feature is enabled.
1613 */
1614#define EXT4_XATTR_BLOCK_RESERVE(inode) min(i_blocksize(inode)/8, 1024U)
1615
1616static int ext4_xattr_set_entry(struct ext4_xattr_info *i,
1617 struct ext4_xattr_search *s,
1618 handle_t *handle, struct inode *inode,
1619 bool is_block)
1620{
1621 struct ext4_xattr_entry *last, *next;
1622 struct ext4_xattr_entry *here = s->here;
1623 size_t min_offs = s->end - s->base, name_len = strlen(i->name);
1624 int in_inode = i->in_inode;
1625 struct inode *old_ea_inode = NULL;
1626 struct inode *new_ea_inode = NULL;
1627 size_t old_size, new_size;
1628 int ret;
1629
1630 /* Space used by old and new values. */
1631 old_size = (!s->not_found && !here->e_value_inum) ?
1632 EXT4_XATTR_SIZE(le32_to_cpu(here->e_value_size)) : 0;
1633 new_size = (i->value && !in_inode) ? EXT4_XATTR_SIZE(i->value_len) : 0;
1634
1635 /*
1636 * Optimization for the simple case when old and new values have the
1637 * same padded sizes. Not applicable if external inodes are involved.
1638 */
1639 if (new_size && new_size == old_size) {
1640 size_t offs = le16_to_cpu(here->e_value_offs);
1641 void *val = s->base + offs;
1642
1643 here->e_value_size = cpu_to_le32(i->value_len);
1644 if (i->value == EXT4_ZERO_XATTR_VALUE) {
1645 memset(val, 0, new_size);
1646 } else {
1647 memcpy(val, i->value, i->value_len);
1648 /* Clear padding bytes. */
1649 memset(val + i->value_len, 0, new_size - i->value_len);
1650 }
1651 goto update_hash;
1652 }
1653
1654 /* Compute min_offs and last. */
1655 last = s->first;
1656 for (; !IS_LAST_ENTRY(last); last = next) {
1657 next = EXT4_XATTR_NEXT(last);
1658 if ((void *)next >= s->end) {
1659 EXT4_ERROR_INODE(inode, "corrupted xattr entries");
1660 ret = -EFSCORRUPTED;
1661 goto out;
1662 }
1663 if (!last->e_value_inum && last->e_value_size) {
1664 size_t offs = le16_to_cpu(last->e_value_offs);
1665 if (offs < min_offs)
1666 min_offs = offs;
1667 }
1668 }
1669
1670 /* Check whether we have enough space. */
1671 if (i->value) {
1672 size_t free;
1673
1674 free = min_offs - ((void *)last - s->base) - sizeof(__u32);
1675 if (!s->not_found)
1676 free += EXT4_XATTR_LEN(name_len) + old_size;
1677
1678 if (free < EXT4_XATTR_LEN(name_len) + new_size) {
1679 ret = -ENOSPC;
1680 goto out;
1681 }
1682
1683 /*
1684 * If storing the value in an external inode is an option,
1685 * reserve space for xattr entries/names in the external
1686 * attribute block so that a long value does not occupy the
1687 * whole space and prevent further entries being added.
1688 */
1689 if (ext4_has_feature_ea_inode(inode->i_sb) &&
1690 new_size && is_block &&
1691 (min_offs + old_size - new_size) <
1692 EXT4_XATTR_BLOCK_RESERVE(inode)) {
1693 ret = -ENOSPC;
1694 goto out;
1695 }
1696 }
1697
1698 /*
1699 * Getting access to old and new ea inodes is subject to failures.
1700 * Finish that work before doing any modifications to the xattr data.
1701 */
1702 if (!s->not_found && here->e_value_inum) {
1703 ret = ext4_xattr_inode_iget(inode,
1704 le32_to_cpu(here->e_value_inum),
1705 le32_to_cpu(here->e_hash),
1706 &old_ea_inode);
1707 if (ret) {
1708 old_ea_inode = NULL;
1709 goto out;
1710 }
1711 }
1712 if (i->value && in_inode) {
1713 WARN_ON_ONCE(!i->value_len);
1714
1715 ret = ext4_xattr_inode_alloc_quota(inode, i->value_len);
1716 if (ret)
1717 goto out;
1718
1719 ret = ext4_xattr_inode_lookup_create(handle, inode, i->value,
1720 i->value_len,
1721 &new_ea_inode);
1722 if (ret) {
1723 new_ea_inode = NULL;
1724 ext4_xattr_inode_free_quota(inode, NULL, i->value_len);
1725 goto out;
1726 }
1727 }
1728
1729 if (old_ea_inode) {
1730 /* We are ready to release ref count on the old_ea_inode. */
1731 ret = ext4_xattr_inode_dec_ref(handle, old_ea_inode);
1732 if (ret) {
1733 /* Release newly required ref count on new_ea_inode. */
1734 if (new_ea_inode) {
1735 int err;
1736
1737 err = ext4_xattr_inode_dec_ref(handle,
1738 new_ea_inode);
1739 if (err)
1740 ext4_warning_inode(new_ea_inode,
1741 "dec ref new_ea_inode err=%d",
1742 err);
1743 ext4_xattr_inode_free_quota(inode, new_ea_inode,
1744 i->value_len);
1745 }
1746 goto out;
1747 }
1748
1749 ext4_xattr_inode_free_quota(inode, old_ea_inode,
1750 le32_to_cpu(here->e_value_size));
1751 }
1752
1753 /* No failures allowed past this point. */
1754
1755 if (!s->not_found && here->e_value_size && !here->e_value_inum) {
1756 /* Remove the old value. */
1757 void *first_val = s->base + min_offs;
1758 size_t offs = le16_to_cpu(here->e_value_offs);
1759 void *val = s->base + offs;
1760
1761 memmove(first_val + old_size, first_val, val - first_val);
1762 memset(first_val, 0, old_size);
1763 min_offs += old_size;
1764
1765 /* Adjust all value offsets. */
1766 last = s->first;
1767 while (!IS_LAST_ENTRY(last)) {
1768 size_t o = le16_to_cpu(last->e_value_offs);
1769
1770 if (!last->e_value_inum &&
1771 last->e_value_size && o < offs)
1772 last->e_value_offs = cpu_to_le16(o + old_size);
1773 last = EXT4_XATTR_NEXT(last);
1774 }
1775 }
1776
1777 if (!i->value) {
1778 /* Remove old name. */
1779 size_t size = EXT4_XATTR_LEN(name_len);
1780
1781 last = ENTRY((void *)last - size);
1782 memmove(here, (void *)here + size,
1783 (void *)last - (void *)here + sizeof(__u32));
1784 memset(last, 0, size);
1785
1786 /*
1787 * Update i_inline_off - moved ibody region might contain
1788 * system.data attribute. Handling a failure here won't
1789 * cause other complications for setting an xattr.
1790 */
1791 if (!is_block && ext4_has_inline_data(inode)) {
1792 ret = ext4_find_inline_data_nolock(inode);
1793 if (ret) {
1794 ext4_warning_inode(inode,
1795 "unable to update i_inline_off");
1796 goto out;
1797 }
1798 }
1799 } else if (s->not_found) {
1800 /* Insert new name. */
1801 size_t size = EXT4_XATTR_LEN(name_len);
1802 size_t rest = (void *)last - (void *)here + sizeof(__u32);
1803
1804 memmove((void *)here + size, here, rest);
1805 memset(here, 0, size);
1806 here->e_name_index = i->name_index;
1807 here->e_name_len = name_len;
1808 memcpy(here->e_name, i->name, name_len);
1809 } else {
1810 /* This is an update, reset value info. */
1811 here->e_value_inum = 0;
1812 here->e_value_offs = 0;
1813 here->e_value_size = 0;
1814 }
1815
1816 if (i->value) {
1817 /* Insert new value. */
1818 if (in_inode) {
1819 here->e_value_inum = cpu_to_le32(new_ea_inode->i_ino);
1820 } else if (i->value_len) {
1821 void *val = s->base + min_offs - new_size;
1822
1823 here->e_value_offs = cpu_to_le16(min_offs - new_size);
1824 if (i->value == EXT4_ZERO_XATTR_VALUE) {
1825 memset(val, 0, new_size);
1826 } else {
1827 memcpy(val, i->value, i->value_len);
1828 /* Clear padding bytes. */
1829 memset(val + i->value_len, 0,
1830 new_size - i->value_len);
1831 }
1832 }
1833 here->e_value_size = cpu_to_le32(i->value_len);
1834 }
1835
1836update_hash:
1837 if (i->value) {
1838 __le32 hash = 0;
1839
1840 /* Entry hash calculation. */
1841 if (in_inode) {
1842 __le32 crc32c_hash;
1843
1844 /*
1845 * Feed crc32c hash instead of the raw value for entry
1846 * hash calculation. This is to avoid walking
1847 * potentially long value buffer again.
1848 */
1849 crc32c_hash = cpu_to_le32(
1850 ext4_xattr_inode_get_hash(new_ea_inode));
1851 hash = ext4_xattr_hash_entry(here->e_name,
1852 here->e_name_len,
1853 &crc32c_hash, 1);
1854 } else if (is_block) {
1855 __le32 *value = s->base + le16_to_cpu(
1856 here->e_value_offs);
1857
1858 hash = ext4_xattr_hash_entry(here->e_name,
1859 here->e_name_len, value,
1860 new_size >> 2);
1861 }
1862 here->e_hash = hash;
1863 }
1864
1865 if (is_block)
1866 ext4_xattr_rehash((struct ext4_xattr_header *)s->base);
1867
1868 ret = 0;
1869out:
1870 iput(old_ea_inode);
1871 iput(new_ea_inode);
1872 return ret;
1873}
1874
1875struct ext4_xattr_block_find {
1876 struct ext4_xattr_search s;
1877 struct buffer_head *bh;
1878};
1879
1880static int
1881ext4_xattr_block_find(struct inode *inode, struct ext4_xattr_info *i,
1882 struct ext4_xattr_block_find *bs)
1883{
1884 struct super_block *sb = inode->i_sb;
1885 int error;
1886
1887 ea_idebug(inode, "name=%d.%s, value=%p, value_len=%ld",
1888 i->name_index, i->name, i->value, (long)i->value_len);
1889
1890 if (EXT4_I(inode)->i_file_acl) {
1891 /* The inode already has an extended attribute block. */
1892 bs->bh = ext4_sb_bread(sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
1893 if (IS_ERR(bs->bh)) {
1894 error = PTR_ERR(bs->bh);
1895 bs->bh = NULL;
1896 return error;
1897 }
1898 ea_bdebug(bs->bh, "b_count=%d, refcount=%d",
1899 atomic_read(&(bs->bh->b_count)),
1900 le32_to_cpu(BHDR(bs->bh)->h_refcount));
1901 error = ext4_xattr_check_block(inode, bs->bh);
1902 if (error)
1903 return error;
1904 /* Find the named attribute. */
1905 bs->s.base = BHDR(bs->bh);
1906 bs->s.first = BFIRST(bs->bh);
1907 bs->s.end = bs->bh->b_data + bs->bh->b_size;
1908 bs->s.here = bs->s.first;
1909 error = xattr_find_entry(inode, &bs->s.here, bs->s.end,
1910 i->name_index, i->name, 1);
1911 if (error && error != -ENODATA)
1912 return error;
1913 bs->s.not_found = error;
1914 }
1915 return 0;
1916}
1917
1918static int
1919ext4_xattr_block_set(handle_t *handle, struct inode *inode,
1920 struct ext4_xattr_info *i,
1921 struct ext4_xattr_block_find *bs)
1922{
1923 struct super_block *sb = inode->i_sb;
1924 struct buffer_head *new_bh = NULL;
1925 struct ext4_xattr_search s_copy = bs->s;
1926 struct ext4_xattr_search *s = &s_copy;
1927 struct mb_cache_entry *ce = NULL;
1928 int error = 0;
1929 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
1930 struct inode *ea_inode = NULL, *tmp_inode;
1931 size_t old_ea_inode_quota = 0;
1932 unsigned int ea_ino;
1933
1934
1935#define header(x) ((struct ext4_xattr_header *)(x))
1936
1937 if (s->base) {
1938 int offset = (char *)s->here - bs->bh->b_data;
1939
1940 BUFFER_TRACE(bs->bh, "get_write_access");
1941 error = ext4_journal_get_write_access(handle, sb, bs->bh,
1942 EXT4_JTR_NONE);
1943 if (error)
1944 goto cleanup;
1945 lock_buffer(bs->bh);
1946
1947 if (header(s->base)->h_refcount == cpu_to_le32(1)) {
1948 __u32 hash = le32_to_cpu(BHDR(bs->bh)->h_hash);
1949
1950 /*
1951 * This must happen under buffer lock for
1952 * ext4_xattr_block_set() to reliably detect modified
1953 * block
1954 */
1955 if (ea_block_cache) {
1956 struct mb_cache_entry *oe;
1957
1958 oe = mb_cache_entry_delete_or_get(ea_block_cache,
1959 hash, bs->bh->b_blocknr);
1960 if (oe) {
1961 /*
1962 * Xattr block is getting reused. Leave
1963 * it alone.
1964 */
1965 mb_cache_entry_put(ea_block_cache, oe);
1966 goto clone_block;
1967 }
1968 }
1969 ea_bdebug(bs->bh, "modifying in-place");
1970 error = ext4_xattr_set_entry(i, s, handle, inode,
1971 true /* is_block */);
1972 ext4_xattr_block_csum_set(inode, bs->bh);
1973 unlock_buffer(bs->bh);
1974 if (error == -EFSCORRUPTED)
1975 goto bad_block;
1976 if (!error)
1977 error = ext4_handle_dirty_metadata(handle,
1978 inode,
1979 bs->bh);
1980 if (error)
1981 goto cleanup;
1982 goto inserted;
1983 }
1984clone_block:
1985 unlock_buffer(bs->bh);
1986 ea_bdebug(bs->bh, "cloning");
1987 s->base = kmemdup(BHDR(bs->bh), bs->bh->b_size, GFP_NOFS);
1988 error = -ENOMEM;
1989 if (s->base == NULL)
1990 goto cleanup;
1991 s->first = ENTRY(header(s->base)+1);
1992 header(s->base)->h_refcount = cpu_to_le32(1);
1993 s->here = ENTRY(s->base + offset);
1994 s->end = s->base + bs->bh->b_size;
1995
1996 /*
1997 * If existing entry points to an xattr inode, we need
1998 * to prevent ext4_xattr_set_entry() from decrementing
1999 * ref count on it because the reference belongs to the
2000 * original block. In this case, make the entry look
2001 * like it has an empty value.
2002 */
2003 if (!s->not_found && s->here->e_value_inum) {
2004 ea_ino = le32_to_cpu(s->here->e_value_inum);
2005 error = ext4_xattr_inode_iget(inode, ea_ino,
2006 le32_to_cpu(s->here->e_hash),
2007 &tmp_inode);
2008 if (error)
2009 goto cleanup;
2010
2011 if (!ext4_test_inode_state(tmp_inode,
2012 EXT4_STATE_LUSTRE_EA_INODE)) {
2013 /*
2014 * Defer quota free call for previous
2015 * inode until success is guaranteed.
2016 */
2017 old_ea_inode_quota = le32_to_cpu(
2018 s->here->e_value_size);
2019 }
2020 iput(tmp_inode);
2021
2022 s->here->e_value_inum = 0;
2023 s->here->e_value_size = 0;
2024 }
2025 } else {
2026 /* Allocate a buffer where we construct the new block. */
2027 s->base = kzalloc(sb->s_blocksize, GFP_NOFS);
2028 error = -ENOMEM;
2029 if (s->base == NULL)
2030 goto cleanup;
2031 header(s->base)->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
2032 header(s->base)->h_blocks = cpu_to_le32(1);
2033 header(s->base)->h_refcount = cpu_to_le32(1);
2034 s->first = ENTRY(header(s->base)+1);
2035 s->here = ENTRY(header(s->base)+1);
2036 s->end = s->base + sb->s_blocksize;
2037 }
2038
2039 error = ext4_xattr_set_entry(i, s, handle, inode, true /* is_block */);
2040 if (error == -EFSCORRUPTED)
2041 goto bad_block;
2042 if (error)
2043 goto cleanup;
2044
2045 if (i->value && s->here->e_value_inum) {
2046 /*
2047 * A ref count on ea_inode has been taken as part of the call to
2048 * ext4_xattr_set_entry() above. We would like to drop this
2049 * extra ref but we have to wait until the xattr block is
2050 * initialized and has its own ref count on the ea_inode.
2051 */
2052 ea_ino = le32_to_cpu(s->here->e_value_inum);
2053 error = ext4_xattr_inode_iget(inode, ea_ino,
2054 le32_to_cpu(s->here->e_hash),
2055 &ea_inode);
2056 if (error) {
2057 ea_inode = NULL;
2058 goto cleanup;
2059 }
2060 }
2061
2062inserted:
2063 if (!IS_LAST_ENTRY(s->first)) {
2064 new_bh = ext4_xattr_block_cache_find(inode, header(s->base),
2065 &ce);
2066 if (new_bh) {
2067 /* We found an identical block in the cache. */
2068 if (new_bh == bs->bh)
2069 ea_bdebug(new_bh, "keeping");
2070 else {
2071 u32 ref;
2072
2073#ifdef EXT4_XATTR_DEBUG
2074 WARN_ON_ONCE(dquot_initialize_needed(inode));
2075#endif
2076 /* The old block is released after updating
2077 the inode. */
2078 error = dquot_alloc_block(inode,
2079 EXT4_C2B(EXT4_SB(sb), 1));
2080 if (error)
2081 goto cleanup;
2082 BUFFER_TRACE(new_bh, "get_write_access");
2083 error = ext4_journal_get_write_access(
2084 handle, sb, new_bh,
2085 EXT4_JTR_NONE);
2086 if (error)
2087 goto cleanup_dquot;
2088 lock_buffer(new_bh);
2089 /*
2090 * We have to be careful about races with
2091 * adding references to xattr block. Once we
2092 * hold buffer lock xattr block's state is
2093 * stable so we can check the additional
2094 * reference fits.
2095 */
2096 ref = le32_to_cpu(BHDR(new_bh)->h_refcount) + 1;
2097 if (ref > EXT4_XATTR_REFCOUNT_MAX) {
2098 /*
2099 * Undo everything and check mbcache
2100 * again.
2101 */
2102 unlock_buffer(new_bh);
2103 dquot_free_block(inode,
2104 EXT4_C2B(EXT4_SB(sb),
2105 1));
2106 brelse(new_bh);
2107 mb_cache_entry_put(ea_block_cache, ce);
2108 ce = NULL;
2109 new_bh = NULL;
2110 goto inserted;
2111 }
2112 BHDR(new_bh)->h_refcount = cpu_to_le32(ref);
2113 if (ref == EXT4_XATTR_REFCOUNT_MAX)
2114 clear_bit(MBE_REUSABLE_B, &ce->e_flags);
2115 ea_bdebug(new_bh, "reusing; refcount now=%d",
2116 ref);
2117 ext4_xattr_block_csum_set(inode, new_bh);
2118 unlock_buffer(new_bh);
2119 error = ext4_handle_dirty_metadata(handle,
2120 inode,
2121 new_bh);
2122 if (error)
2123 goto cleanup_dquot;
2124 }
2125 mb_cache_entry_touch(ea_block_cache, ce);
2126 mb_cache_entry_put(ea_block_cache, ce);
2127 ce = NULL;
2128 } else if (bs->bh && s->base == bs->bh->b_data) {
2129 /* We were modifying this block in-place. */
2130 ea_bdebug(bs->bh, "keeping this block");
2131 ext4_xattr_block_cache_insert(ea_block_cache, bs->bh);
2132 new_bh = bs->bh;
2133 get_bh(new_bh);
2134 } else {
2135 /* We need to allocate a new block */
2136 ext4_fsblk_t goal, block;
2137
2138#ifdef EXT4_XATTR_DEBUG
2139 WARN_ON_ONCE(dquot_initialize_needed(inode));
2140#endif
2141 goal = ext4_group_first_block_no(sb,
2142 EXT4_I(inode)->i_block_group);
2143 block = ext4_new_meta_blocks(handle, inode, goal, 0,
2144 NULL, &error);
2145 if (error)
2146 goto cleanup;
2147
2148 ea_idebug(inode, "creating block %llu",
2149 (unsigned long long)block);
2150
2151 new_bh = sb_getblk(sb, block);
2152 if (unlikely(!new_bh)) {
2153 error = -ENOMEM;
2154getblk_failed:
2155 ext4_free_blocks(handle, inode, NULL, block, 1,
2156 EXT4_FREE_BLOCKS_METADATA);
2157 goto cleanup;
2158 }
2159 error = ext4_xattr_inode_inc_ref_all(handle, inode,
2160 ENTRY(header(s->base)+1));
2161 if (error)
2162 goto getblk_failed;
2163 if (ea_inode) {
2164 /* Drop the extra ref on ea_inode. */
2165 error = ext4_xattr_inode_dec_ref(handle,
2166 ea_inode);
2167 if (error)
2168 ext4_warning_inode(ea_inode,
2169 "dec ref error=%d",
2170 error);
2171 iput(ea_inode);
2172 ea_inode = NULL;
2173 }
2174
2175 lock_buffer(new_bh);
2176 error = ext4_journal_get_create_access(handle, sb,
2177 new_bh, EXT4_JTR_NONE);
2178 if (error) {
2179 unlock_buffer(new_bh);
2180 error = -EIO;
2181 goto getblk_failed;
2182 }
2183 memcpy(new_bh->b_data, s->base, new_bh->b_size);
2184 ext4_xattr_block_csum_set(inode, new_bh);
2185 set_buffer_uptodate(new_bh);
2186 unlock_buffer(new_bh);
2187 ext4_xattr_block_cache_insert(ea_block_cache, new_bh);
2188 error = ext4_handle_dirty_metadata(handle, inode,
2189 new_bh);
2190 if (error)
2191 goto cleanup;
2192 }
2193 }
2194
2195 if (old_ea_inode_quota)
2196 ext4_xattr_inode_free_quota(inode, NULL, old_ea_inode_quota);
2197
2198 /* Update the inode. */
2199 EXT4_I(inode)->i_file_acl = new_bh ? new_bh->b_blocknr : 0;
2200
2201 /* Drop the previous xattr block. */
2202 if (bs->bh && bs->bh != new_bh) {
2203 struct ext4_xattr_inode_array *ea_inode_array = NULL;
2204
2205 ext4_xattr_release_block(handle, inode, bs->bh,
2206 &ea_inode_array,
2207 0 /* extra_credits */);
2208 ext4_xattr_inode_array_free(ea_inode_array);
2209 }
2210 error = 0;
2211
2212cleanup:
2213 if (ea_inode) {
2214 int error2;
2215
2216 error2 = ext4_xattr_inode_dec_ref(handle, ea_inode);
2217 if (error2)
2218 ext4_warning_inode(ea_inode, "dec ref error=%d",
2219 error2);
2220
2221 /* If there was an error, revert the quota charge. */
2222 if (error)
2223 ext4_xattr_inode_free_quota(inode, ea_inode,
2224 i_size_read(ea_inode));
2225 iput(ea_inode);
2226 }
2227 if (ce)
2228 mb_cache_entry_put(ea_block_cache, ce);
2229 brelse(new_bh);
2230 if (!(bs->bh && s->base == bs->bh->b_data))
2231 kfree(s->base);
2232
2233 return error;
2234
2235cleanup_dquot:
2236 dquot_free_block(inode, EXT4_C2B(EXT4_SB(sb), 1));
2237 goto cleanup;
2238
2239bad_block:
2240 EXT4_ERROR_INODE(inode, "bad block %llu",
2241 EXT4_I(inode)->i_file_acl);
2242 goto cleanup;
2243
2244#undef header
2245}
2246
2247int ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i,
2248 struct ext4_xattr_ibody_find *is)
2249{
2250 struct ext4_xattr_ibody_header *header;
2251 struct ext4_inode *raw_inode;
2252 int error;
2253
2254 if (!EXT4_INODE_HAS_XATTR_SPACE(inode))
2255 return 0;
2256
2257 raw_inode = ext4_raw_inode(&is->iloc);
2258 header = IHDR(inode, raw_inode);
2259 is->s.base = is->s.first = IFIRST(header);
2260 is->s.here = is->s.first;
2261 is->s.end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
2262 if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
2263 error = xattr_check_inode(inode, header, is->s.end);
2264 if (error)
2265 return error;
2266 /* Find the named attribute. */
2267 error = xattr_find_entry(inode, &is->s.here, is->s.end,
2268 i->name_index, i->name, 0);
2269 if (error && error != -ENODATA)
2270 return error;
2271 is->s.not_found = error;
2272 }
2273 return 0;
2274}
2275
2276int ext4_xattr_ibody_set(handle_t *handle, struct inode *inode,
2277 struct ext4_xattr_info *i,
2278 struct ext4_xattr_ibody_find *is)
2279{
2280 struct ext4_xattr_ibody_header *header;
2281 struct ext4_xattr_search *s = &is->s;
2282 int error;
2283
2284 if (!EXT4_INODE_HAS_XATTR_SPACE(inode))
2285 return -ENOSPC;
2286
2287 error = ext4_xattr_set_entry(i, s, handle, inode, false /* is_block */);
2288 if (error)
2289 return error;
2290 header = IHDR(inode, ext4_raw_inode(&is->iloc));
2291 if (!IS_LAST_ENTRY(s->first)) {
2292 header->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
2293 ext4_set_inode_state(inode, EXT4_STATE_XATTR);
2294 } else {
2295 header->h_magic = cpu_to_le32(0);
2296 ext4_clear_inode_state(inode, EXT4_STATE_XATTR);
2297 }
2298 return 0;
2299}
2300
2301static int ext4_xattr_value_same(struct ext4_xattr_search *s,
2302 struct ext4_xattr_info *i)
2303{
2304 void *value;
2305
2306 /* When e_value_inum is set the value is stored externally. */
2307 if (s->here->e_value_inum)
2308 return 0;
2309 if (le32_to_cpu(s->here->e_value_size) != i->value_len)
2310 return 0;
2311 value = ((void *)s->base) + le16_to_cpu(s->here->e_value_offs);
2312 return !memcmp(value, i->value, i->value_len);
2313}
2314
2315static struct buffer_head *ext4_xattr_get_block(struct inode *inode)
2316{
2317 struct buffer_head *bh;
2318 int error;
2319
2320 if (!EXT4_I(inode)->i_file_acl)
2321 return NULL;
2322 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
2323 if (IS_ERR(bh))
2324 return bh;
2325 error = ext4_xattr_check_block(inode, bh);
2326 if (error) {
2327 brelse(bh);
2328 return ERR_PTR(error);
2329 }
2330 return bh;
2331}
2332
2333/*
2334 * ext4_xattr_set_handle()
2335 *
2336 * Create, replace or remove an extended attribute for this inode. Value
2337 * is NULL to remove an existing extended attribute, and non-NULL to
2338 * either replace an existing extended attribute, or create a new extended
2339 * attribute. The flags XATTR_REPLACE and XATTR_CREATE
2340 * specify that an extended attribute must exist and must not exist
2341 * previous to the call, respectively.
2342 *
2343 * Returns 0, or a negative error number on failure.
2344 */
2345int
2346ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
2347 const char *name, const void *value, size_t value_len,
2348 int flags)
2349{
2350 struct ext4_xattr_info i = {
2351 .name_index = name_index,
2352 .name = name,
2353 .value = value,
2354 .value_len = value_len,
2355 .in_inode = 0,
2356 };
2357 struct ext4_xattr_ibody_find is = {
2358 .s = { .not_found = -ENODATA, },
2359 };
2360 struct ext4_xattr_block_find bs = {
2361 .s = { .not_found = -ENODATA, },
2362 };
2363 int no_expand;
2364 int error;
2365
2366 if (!name)
2367 return -EINVAL;
2368 if (strlen(name) > 255)
2369 return -ERANGE;
2370
2371 ext4_write_lock_xattr(inode, &no_expand);
2372
2373 /* Check journal credits under write lock. */
2374 if (ext4_handle_valid(handle)) {
2375 struct buffer_head *bh;
2376 int credits;
2377
2378 bh = ext4_xattr_get_block(inode);
2379 if (IS_ERR(bh)) {
2380 error = PTR_ERR(bh);
2381 goto cleanup;
2382 }
2383
2384 credits = __ext4_xattr_set_credits(inode->i_sb, inode, bh,
2385 value_len,
2386 flags & XATTR_CREATE);
2387 brelse(bh);
2388
2389 if (jbd2_handle_buffer_credits(handle) < credits) {
2390 error = -ENOSPC;
2391 goto cleanup;
2392 }
2393 WARN_ON_ONCE(!(current->flags & PF_MEMALLOC_NOFS));
2394 }
2395
2396 error = ext4_reserve_inode_write(handle, inode, &is.iloc);
2397 if (error)
2398 goto cleanup;
2399
2400 if (ext4_test_inode_state(inode, EXT4_STATE_NEW)) {
2401 struct ext4_inode *raw_inode = ext4_raw_inode(&is.iloc);
2402 memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size);
2403 ext4_clear_inode_state(inode, EXT4_STATE_NEW);
2404 }
2405
2406 error = ext4_xattr_ibody_find(inode, &i, &is);
2407 if (error)
2408 goto cleanup;
2409 if (is.s.not_found)
2410 error = ext4_xattr_block_find(inode, &i, &bs);
2411 if (error)
2412 goto cleanup;
2413 if (is.s.not_found && bs.s.not_found) {
2414 error = -ENODATA;
2415 if (flags & XATTR_REPLACE)
2416 goto cleanup;
2417 error = 0;
2418 if (!value)
2419 goto cleanup;
2420 } else {
2421 error = -EEXIST;
2422 if (flags & XATTR_CREATE)
2423 goto cleanup;
2424 }
2425
2426 if (!value) {
2427 if (!is.s.not_found)
2428 error = ext4_xattr_ibody_set(handle, inode, &i, &is);
2429 else if (!bs.s.not_found)
2430 error = ext4_xattr_block_set(handle, inode, &i, &bs);
2431 } else {
2432 error = 0;
2433 /* Xattr value did not change? Save us some work and bail out */
2434 if (!is.s.not_found && ext4_xattr_value_same(&is.s, &i))
2435 goto cleanup;
2436 if (!bs.s.not_found && ext4_xattr_value_same(&bs.s, &i))
2437 goto cleanup;
2438
2439 if (ext4_has_feature_ea_inode(inode->i_sb) &&
2440 (EXT4_XATTR_SIZE(i.value_len) >
2441 EXT4_XATTR_MIN_LARGE_EA_SIZE(inode->i_sb->s_blocksize)))
2442 i.in_inode = 1;
2443retry_inode:
2444 error = ext4_xattr_ibody_set(handle, inode, &i, &is);
2445 if (!error && !bs.s.not_found) {
2446 i.value = NULL;
2447 error = ext4_xattr_block_set(handle, inode, &i, &bs);
2448 } else if (error == -ENOSPC) {
2449 if (EXT4_I(inode)->i_file_acl && !bs.s.base) {
2450 brelse(bs.bh);
2451 bs.bh = NULL;
2452 error = ext4_xattr_block_find(inode, &i, &bs);
2453 if (error)
2454 goto cleanup;
2455 }
2456 error = ext4_xattr_block_set(handle, inode, &i, &bs);
2457 if (!error && !is.s.not_found) {
2458 i.value = NULL;
2459 error = ext4_xattr_ibody_set(handle, inode, &i,
2460 &is);
2461 } else if (error == -ENOSPC) {
2462 /*
2463 * Xattr does not fit in the block, store at
2464 * external inode if possible.
2465 */
2466 if (ext4_has_feature_ea_inode(inode->i_sb) &&
2467 i.value_len && !i.in_inode) {
2468 i.in_inode = 1;
2469 goto retry_inode;
2470 }
2471 }
2472 }
2473 }
2474 if (!error) {
2475 ext4_xattr_update_super_block(handle, inode->i_sb);
2476 inode_set_ctime_current(inode);
2477 inode_inc_iversion(inode);
2478 if (!value)
2479 no_expand = 0;
2480 error = ext4_mark_iloc_dirty(handle, inode, &is.iloc);
2481 /*
2482 * The bh is consumed by ext4_mark_iloc_dirty, even with
2483 * error != 0.
2484 */
2485 is.iloc.bh = NULL;
2486 if (IS_SYNC(inode))
2487 ext4_handle_sync(handle);
2488 }
2489 ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_XATTR, handle);
2490
2491cleanup:
2492 brelse(is.iloc.bh);
2493 brelse(bs.bh);
2494 ext4_write_unlock_xattr(inode, &no_expand);
2495 return error;
2496}
2497
2498int ext4_xattr_set_credits(struct inode *inode, size_t value_len,
2499 bool is_create, int *credits)
2500{
2501 struct buffer_head *bh;
2502 int err;
2503
2504 *credits = 0;
2505
2506 if (!EXT4_SB(inode->i_sb)->s_journal)
2507 return 0;
2508
2509 down_read(&EXT4_I(inode)->xattr_sem);
2510
2511 bh = ext4_xattr_get_block(inode);
2512 if (IS_ERR(bh)) {
2513 err = PTR_ERR(bh);
2514 } else {
2515 *credits = __ext4_xattr_set_credits(inode->i_sb, inode, bh,
2516 value_len, is_create);
2517 brelse(bh);
2518 err = 0;
2519 }
2520
2521 up_read(&EXT4_I(inode)->xattr_sem);
2522 return err;
2523}
2524
2525/*
2526 * ext4_xattr_set()
2527 *
2528 * Like ext4_xattr_set_handle, but start from an inode. This extended
2529 * attribute modification is a filesystem transaction by itself.
2530 *
2531 * Returns 0, or a negative error number on failure.
2532 */
2533int
2534ext4_xattr_set(struct inode *inode, int name_index, const char *name,
2535 const void *value, size_t value_len, int flags)
2536{
2537 handle_t *handle;
2538 struct super_block *sb = inode->i_sb;
2539 int error, retries = 0;
2540 int credits;
2541
2542 error = dquot_initialize(inode);
2543 if (error)
2544 return error;
2545
2546retry:
2547 error = ext4_xattr_set_credits(inode, value_len, flags & XATTR_CREATE,
2548 &credits);
2549 if (error)
2550 return error;
2551
2552 handle = ext4_journal_start(inode, EXT4_HT_XATTR, credits);
2553 if (IS_ERR(handle)) {
2554 error = PTR_ERR(handle);
2555 } else {
2556 int error2;
2557
2558 error = ext4_xattr_set_handle(handle, inode, name_index, name,
2559 value, value_len, flags);
2560 error2 = ext4_journal_stop(handle);
2561 if (error == -ENOSPC &&
2562 ext4_should_retry_alloc(sb, &retries))
2563 goto retry;
2564 if (error == 0)
2565 error = error2;
2566 }
2567 ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_XATTR, NULL);
2568
2569 return error;
2570}
2571
2572/*
2573 * Shift the EA entries in the inode to create space for the increased
2574 * i_extra_isize.
2575 */
2576static void ext4_xattr_shift_entries(struct ext4_xattr_entry *entry,
2577 int value_offs_shift, void *to,
2578 void *from, size_t n)
2579{
2580 struct ext4_xattr_entry *last = entry;
2581 int new_offs;
2582
2583 /* We always shift xattr headers further thus offsets get lower */
2584 BUG_ON(value_offs_shift > 0);
2585
2586 /* Adjust the value offsets of the entries */
2587 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
2588 if (!last->e_value_inum && last->e_value_size) {
2589 new_offs = le16_to_cpu(last->e_value_offs) +
2590 value_offs_shift;
2591 last->e_value_offs = cpu_to_le16(new_offs);
2592 }
2593 }
2594 /* Shift the entries by n bytes */
2595 memmove(to, from, n);
2596}
2597
2598/*
2599 * Move xattr pointed to by 'entry' from inode into external xattr block
2600 */
2601static int ext4_xattr_move_to_block(handle_t *handle, struct inode *inode,
2602 struct ext4_inode *raw_inode,
2603 struct ext4_xattr_entry *entry)
2604{
2605 struct ext4_xattr_ibody_find *is = NULL;
2606 struct ext4_xattr_block_find *bs = NULL;
2607 char *buffer = NULL, *b_entry_name = NULL;
2608 size_t value_size = le32_to_cpu(entry->e_value_size);
2609 struct ext4_xattr_info i = {
2610 .value = NULL,
2611 .value_len = 0,
2612 .name_index = entry->e_name_index,
2613 .in_inode = !!entry->e_value_inum,
2614 };
2615 struct ext4_xattr_ibody_header *header = IHDR(inode, raw_inode);
2616 int needs_kvfree = 0;
2617 int error;
2618
2619 is = kzalloc(sizeof(struct ext4_xattr_ibody_find), GFP_NOFS);
2620 bs = kzalloc(sizeof(struct ext4_xattr_block_find), GFP_NOFS);
2621 b_entry_name = kmalloc(entry->e_name_len + 1, GFP_NOFS);
2622 if (!is || !bs || !b_entry_name) {
2623 error = -ENOMEM;
2624 goto out;
2625 }
2626
2627 is->s.not_found = -ENODATA;
2628 bs->s.not_found = -ENODATA;
2629 is->iloc.bh = NULL;
2630 bs->bh = NULL;
2631
2632 /* Save the entry name and the entry value */
2633 if (entry->e_value_inum) {
2634 buffer = kvmalloc(value_size, GFP_NOFS);
2635 if (!buffer) {
2636 error = -ENOMEM;
2637 goto out;
2638 }
2639 needs_kvfree = 1;
2640 error = ext4_xattr_inode_get(inode, entry, buffer, value_size);
2641 if (error)
2642 goto out;
2643 } else {
2644 size_t value_offs = le16_to_cpu(entry->e_value_offs);
2645 buffer = (void *)IFIRST(header) + value_offs;
2646 }
2647
2648 memcpy(b_entry_name, entry->e_name, entry->e_name_len);
2649 b_entry_name[entry->e_name_len] = '\0';
2650 i.name = b_entry_name;
2651
2652 error = ext4_get_inode_loc(inode, &is->iloc);
2653 if (error)
2654 goto out;
2655
2656 error = ext4_xattr_ibody_find(inode, &i, is);
2657 if (error)
2658 goto out;
2659
2660 i.value = buffer;
2661 i.value_len = value_size;
2662 error = ext4_xattr_block_find(inode, &i, bs);
2663 if (error)
2664 goto out;
2665
2666 /* Move ea entry from the inode into the block */
2667 error = ext4_xattr_block_set(handle, inode, &i, bs);
2668 if (error)
2669 goto out;
2670
2671 /* Remove the chosen entry from the inode */
2672 i.value = NULL;
2673 i.value_len = 0;
2674 error = ext4_xattr_ibody_set(handle, inode, &i, is);
2675
2676out:
2677 kfree(b_entry_name);
2678 if (needs_kvfree && buffer)
2679 kvfree(buffer);
2680 if (is)
2681 brelse(is->iloc.bh);
2682 if (bs)
2683 brelse(bs->bh);
2684 kfree(is);
2685 kfree(bs);
2686
2687 return error;
2688}
2689
2690static int ext4_xattr_make_inode_space(handle_t *handle, struct inode *inode,
2691 struct ext4_inode *raw_inode,
2692 int isize_diff, size_t ifree,
2693 size_t bfree, int *total_ino)
2694{
2695 struct ext4_xattr_ibody_header *header = IHDR(inode, raw_inode);
2696 struct ext4_xattr_entry *small_entry;
2697 struct ext4_xattr_entry *entry;
2698 struct ext4_xattr_entry *last;
2699 unsigned int entry_size; /* EA entry size */
2700 unsigned int total_size; /* EA entry size + value size */
2701 unsigned int min_total_size;
2702 int error;
2703
2704 while (isize_diff > ifree) {
2705 entry = NULL;
2706 small_entry = NULL;
2707 min_total_size = ~0U;
2708 last = IFIRST(header);
2709 /* Find the entry best suited to be pushed into EA block */
2710 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
2711 /* never move system.data out of the inode */
2712 if ((last->e_name_len == 4) &&
2713 (last->e_name_index == EXT4_XATTR_INDEX_SYSTEM) &&
2714 !memcmp(last->e_name, "data", 4))
2715 continue;
2716 total_size = EXT4_XATTR_LEN(last->e_name_len);
2717 if (!last->e_value_inum)
2718 total_size += EXT4_XATTR_SIZE(
2719 le32_to_cpu(last->e_value_size));
2720 if (total_size <= bfree &&
2721 total_size < min_total_size) {
2722 if (total_size + ifree < isize_diff) {
2723 small_entry = last;
2724 } else {
2725 entry = last;
2726 min_total_size = total_size;
2727 }
2728 }
2729 }
2730
2731 if (entry == NULL) {
2732 if (small_entry == NULL)
2733 return -ENOSPC;
2734 entry = small_entry;
2735 }
2736
2737 entry_size = EXT4_XATTR_LEN(entry->e_name_len);
2738 total_size = entry_size;
2739 if (!entry->e_value_inum)
2740 total_size += EXT4_XATTR_SIZE(
2741 le32_to_cpu(entry->e_value_size));
2742 error = ext4_xattr_move_to_block(handle, inode, raw_inode,
2743 entry);
2744 if (error)
2745 return error;
2746
2747 *total_ino -= entry_size;
2748 ifree += total_size;
2749 bfree -= total_size;
2750 }
2751
2752 return 0;
2753}
2754
2755/*
2756 * Expand an inode by new_extra_isize bytes when EAs are present.
2757 * Returns 0 on success or negative error number on failure.
2758 */
2759int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
2760 struct ext4_inode *raw_inode, handle_t *handle)
2761{
2762 struct ext4_xattr_ibody_header *header;
2763 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2764 static unsigned int mnt_count;
2765 size_t min_offs;
2766 size_t ifree, bfree;
2767 int total_ino;
2768 void *base, *end;
2769 int error = 0, tried_min_extra_isize = 0;
2770 int s_min_extra_isize = le16_to_cpu(sbi->s_es->s_min_extra_isize);
2771 int isize_diff; /* How much do we need to grow i_extra_isize */
2772
2773retry:
2774 isize_diff = new_extra_isize - EXT4_I(inode)->i_extra_isize;
2775 if (EXT4_I(inode)->i_extra_isize >= new_extra_isize)
2776 return 0;
2777
2778 header = IHDR(inode, raw_inode);
2779
2780 /*
2781 * Check if enough free space is available in the inode to shift the
2782 * entries ahead by new_extra_isize.
2783 */
2784
2785 base = IFIRST(header);
2786 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
2787 min_offs = end - base;
2788 total_ino = sizeof(struct ext4_xattr_ibody_header) + sizeof(u32);
2789
2790 error = xattr_check_inode(inode, header, end);
2791 if (error)
2792 goto cleanup;
2793
2794 ifree = ext4_xattr_free_space(base, &min_offs, base, &total_ino);
2795 if (ifree >= isize_diff)
2796 goto shift;
2797
2798 /*
2799 * Enough free space isn't available in the inode, check if
2800 * EA block can hold new_extra_isize bytes.
2801 */
2802 if (EXT4_I(inode)->i_file_acl) {
2803 struct buffer_head *bh;
2804
2805 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
2806 if (IS_ERR(bh)) {
2807 error = PTR_ERR(bh);
2808 goto cleanup;
2809 }
2810 error = ext4_xattr_check_block(inode, bh);
2811 if (error) {
2812 brelse(bh);
2813 goto cleanup;
2814 }
2815 base = BHDR(bh);
2816 end = bh->b_data + bh->b_size;
2817 min_offs = end - base;
2818 bfree = ext4_xattr_free_space(BFIRST(bh), &min_offs, base,
2819 NULL);
2820 brelse(bh);
2821 if (bfree + ifree < isize_diff) {
2822 if (!tried_min_extra_isize && s_min_extra_isize) {
2823 tried_min_extra_isize++;
2824 new_extra_isize = s_min_extra_isize;
2825 goto retry;
2826 }
2827 error = -ENOSPC;
2828 goto cleanup;
2829 }
2830 } else {
2831 bfree = inode->i_sb->s_blocksize;
2832 }
2833
2834 error = ext4_xattr_make_inode_space(handle, inode, raw_inode,
2835 isize_diff, ifree, bfree,
2836 &total_ino);
2837 if (error) {
2838 if (error == -ENOSPC && !tried_min_extra_isize &&
2839 s_min_extra_isize) {
2840 tried_min_extra_isize++;
2841 new_extra_isize = s_min_extra_isize;
2842 goto retry;
2843 }
2844 goto cleanup;
2845 }
2846shift:
2847 /* Adjust the offsets and shift the remaining entries ahead */
2848 ext4_xattr_shift_entries(IFIRST(header), EXT4_I(inode)->i_extra_isize
2849 - new_extra_isize, (void *)raw_inode +
2850 EXT4_GOOD_OLD_INODE_SIZE + new_extra_isize,
2851 (void *)header, total_ino);
2852 EXT4_I(inode)->i_extra_isize = new_extra_isize;
2853
2854 if (ext4_has_inline_data(inode))
2855 error = ext4_find_inline_data_nolock(inode);
2856
2857cleanup:
2858 if (error && (mnt_count != le16_to_cpu(sbi->s_es->s_mnt_count))) {
2859 ext4_warning(inode->i_sb, "Unable to expand inode %lu. Delete some EAs or run e2fsck.",
2860 inode->i_ino);
2861 mnt_count = le16_to_cpu(sbi->s_es->s_mnt_count);
2862 }
2863 return error;
2864}
2865
2866#define EIA_INCR 16 /* must be 2^n */
2867#define EIA_MASK (EIA_INCR - 1)
2868
2869/* Add the large xattr @inode into @ea_inode_array for deferred iput().
2870 * If @ea_inode_array is new or full it will be grown and the old
2871 * contents copied over.
2872 */
2873static int
2874ext4_expand_inode_array(struct ext4_xattr_inode_array **ea_inode_array,
2875 struct inode *inode)
2876{
2877 if (*ea_inode_array == NULL) {
2878 /*
2879 * Start with 15 inodes, so it fits into a power-of-two size.
2880 * If *ea_inode_array is NULL, this is essentially offsetof()
2881 */
2882 (*ea_inode_array) =
2883 kmalloc(offsetof(struct ext4_xattr_inode_array,
2884 inodes[EIA_MASK]),
2885 GFP_NOFS);
2886 if (*ea_inode_array == NULL)
2887 return -ENOMEM;
2888 (*ea_inode_array)->count = 0;
2889 } else if (((*ea_inode_array)->count & EIA_MASK) == EIA_MASK) {
2890 /* expand the array once all 15 + n * 16 slots are full */
2891 struct ext4_xattr_inode_array *new_array = NULL;
2892 int count = (*ea_inode_array)->count;
2893
2894 /* if new_array is NULL, this is essentially offsetof() */
2895 new_array = kmalloc(
2896 offsetof(struct ext4_xattr_inode_array,
2897 inodes[count + EIA_INCR]),
2898 GFP_NOFS);
2899 if (new_array == NULL)
2900 return -ENOMEM;
2901 memcpy(new_array, *ea_inode_array,
2902 offsetof(struct ext4_xattr_inode_array, inodes[count]));
2903 kfree(*ea_inode_array);
2904 *ea_inode_array = new_array;
2905 }
2906 (*ea_inode_array)->inodes[(*ea_inode_array)->count++] = inode;
2907 return 0;
2908}
2909
2910/*
2911 * ext4_xattr_delete_inode()
2912 *
2913 * Free extended attribute resources associated with this inode. Traverse
2914 * all entries and decrement reference on any xattr inodes associated with this
2915 * inode. This is called immediately before an inode is freed. We have exclusive
2916 * access to the inode. If an orphan inode is deleted it will also release its
2917 * references on xattr block and xattr inodes.
2918 */
2919int ext4_xattr_delete_inode(handle_t *handle, struct inode *inode,
2920 struct ext4_xattr_inode_array **ea_inode_array,
2921 int extra_credits)
2922{
2923 struct buffer_head *bh = NULL;
2924 struct ext4_xattr_ibody_header *header;
2925 struct ext4_iloc iloc = { .bh = NULL };
2926 struct ext4_xattr_entry *entry;
2927 struct inode *ea_inode;
2928 int error;
2929
2930 error = ext4_journal_ensure_credits(handle, extra_credits,
2931 ext4_free_metadata_revoke_credits(inode->i_sb, 1));
2932 if (error < 0) {
2933 EXT4_ERROR_INODE(inode, "ensure credits (error %d)", error);
2934 goto cleanup;
2935 }
2936
2937 if (ext4_has_feature_ea_inode(inode->i_sb) &&
2938 ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
2939
2940 error = ext4_get_inode_loc(inode, &iloc);
2941 if (error) {
2942 EXT4_ERROR_INODE(inode, "inode loc (error %d)", error);
2943 goto cleanup;
2944 }
2945
2946 error = ext4_journal_get_write_access(handle, inode->i_sb,
2947 iloc.bh, EXT4_JTR_NONE);
2948 if (error) {
2949 EXT4_ERROR_INODE(inode, "write access (error %d)",
2950 error);
2951 goto cleanup;
2952 }
2953
2954 header = IHDR(inode, ext4_raw_inode(&iloc));
2955 if (header->h_magic == cpu_to_le32(EXT4_XATTR_MAGIC))
2956 ext4_xattr_inode_dec_ref_all(handle, inode, iloc.bh,
2957 IFIRST(header),
2958 false /* block_csum */,
2959 ea_inode_array,
2960 extra_credits,
2961 false /* skip_quota */);
2962 }
2963
2964 if (EXT4_I(inode)->i_file_acl) {
2965 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
2966 if (IS_ERR(bh)) {
2967 error = PTR_ERR(bh);
2968 if (error == -EIO) {
2969 EXT4_ERROR_INODE_ERR(inode, EIO,
2970 "block %llu read error",
2971 EXT4_I(inode)->i_file_acl);
2972 }
2973 bh = NULL;
2974 goto cleanup;
2975 }
2976 error = ext4_xattr_check_block(inode, bh);
2977 if (error)
2978 goto cleanup;
2979
2980 if (ext4_has_feature_ea_inode(inode->i_sb)) {
2981 for (entry = BFIRST(bh); !IS_LAST_ENTRY(entry);
2982 entry = EXT4_XATTR_NEXT(entry)) {
2983 if (!entry->e_value_inum)
2984 continue;
2985 error = ext4_xattr_inode_iget(inode,
2986 le32_to_cpu(entry->e_value_inum),
2987 le32_to_cpu(entry->e_hash),
2988 &ea_inode);
2989 if (error)
2990 continue;
2991 ext4_xattr_inode_free_quota(inode, ea_inode,
2992 le32_to_cpu(entry->e_value_size));
2993 iput(ea_inode);
2994 }
2995
2996 }
2997
2998 ext4_xattr_release_block(handle, inode, bh, ea_inode_array,
2999 extra_credits);
3000 /*
3001 * Update i_file_acl value in the same transaction that releases
3002 * block.
3003 */
3004 EXT4_I(inode)->i_file_acl = 0;
3005 error = ext4_mark_inode_dirty(handle, inode);
3006 if (error) {
3007 EXT4_ERROR_INODE(inode, "mark inode dirty (error %d)",
3008 error);
3009 goto cleanup;
3010 }
3011 ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_XATTR, handle);
3012 }
3013 error = 0;
3014cleanup:
3015 brelse(iloc.bh);
3016 brelse(bh);
3017 return error;
3018}
3019
3020void ext4_xattr_inode_array_free(struct ext4_xattr_inode_array *ea_inode_array)
3021{
3022 int idx;
3023
3024 if (ea_inode_array == NULL)
3025 return;
3026
3027 for (idx = 0; idx < ea_inode_array->count; ++idx)
3028 iput(ea_inode_array->inodes[idx]);
3029 kfree(ea_inode_array);
3030}
3031
3032/*
3033 * ext4_xattr_block_cache_insert()
3034 *
3035 * Create a new entry in the extended attribute block cache, and insert
3036 * it unless such an entry is already in the cache.
3037 *
3038 * Returns 0, or a negative error number on failure.
3039 */
3040static void
3041ext4_xattr_block_cache_insert(struct mb_cache *ea_block_cache,
3042 struct buffer_head *bh)
3043{
3044 struct ext4_xattr_header *header = BHDR(bh);
3045 __u32 hash = le32_to_cpu(header->h_hash);
3046 int reusable = le32_to_cpu(header->h_refcount) <
3047 EXT4_XATTR_REFCOUNT_MAX;
3048 int error;
3049
3050 if (!ea_block_cache)
3051 return;
3052 error = mb_cache_entry_create(ea_block_cache, GFP_NOFS, hash,
3053 bh->b_blocknr, reusable);
3054 if (error) {
3055 if (error == -EBUSY)
3056 ea_bdebug(bh, "already in cache");
3057 } else
3058 ea_bdebug(bh, "inserting [%x]", (int)hash);
3059}
3060
3061/*
3062 * ext4_xattr_cmp()
3063 *
3064 * Compare two extended attribute blocks for equality.
3065 *
3066 * Returns 0 if the blocks are equal, 1 if they differ, and
3067 * a negative error number on errors.
3068 */
3069static int
3070ext4_xattr_cmp(struct ext4_xattr_header *header1,
3071 struct ext4_xattr_header *header2)
3072{
3073 struct ext4_xattr_entry *entry1, *entry2;
3074
3075 entry1 = ENTRY(header1+1);
3076 entry2 = ENTRY(header2+1);
3077 while (!IS_LAST_ENTRY(entry1)) {
3078 if (IS_LAST_ENTRY(entry2))
3079 return 1;
3080 if (entry1->e_hash != entry2->e_hash ||
3081 entry1->e_name_index != entry2->e_name_index ||
3082 entry1->e_name_len != entry2->e_name_len ||
3083 entry1->e_value_size != entry2->e_value_size ||
3084 entry1->e_value_inum != entry2->e_value_inum ||
3085 memcmp(entry1->e_name, entry2->e_name, entry1->e_name_len))
3086 return 1;
3087 if (!entry1->e_value_inum &&
3088 memcmp((char *)header1 + le16_to_cpu(entry1->e_value_offs),
3089 (char *)header2 + le16_to_cpu(entry2->e_value_offs),
3090 le32_to_cpu(entry1->e_value_size)))
3091 return 1;
3092
3093 entry1 = EXT4_XATTR_NEXT(entry1);
3094 entry2 = EXT4_XATTR_NEXT(entry2);
3095 }
3096 if (!IS_LAST_ENTRY(entry2))
3097 return 1;
3098 return 0;
3099}
3100
3101/*
3102 * ext4_xattr_block_cache_find()
3103 *
3104 * Find an identical extended attribute block.
3105 *
3106 * Returns a pointer to the block found, or NULL if such a block was
3107 * not found or an error occurred.
3108 */
3109static struct buffer_head *
3110ext4_xattr_block_cache_find(struct inode *inode,
3111 struct ext4_xattr_header *header,
3112 struct mb_cache_entry **pce)
3113{
3114 __u32 hash = le32_to_cpu(header->h_hash);
3115 struct mb_cache_entry *ce;
3116 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
3117
3118 if (!ea_block_cache)
3119 return NULL;
3120 if (!header->h_hash)
3121 return NULL; /* never share */
3122 ea_idebug(inode, "looking for cached blocks [%x]", (int)hash);
3123 ce = mb_cache_entry_find_first(ea_block_cache, hash);
3124 while (ce) {
3125 struct buffer_head *bh;
3126
3127 bh = ext4_sb_bread(inode->i_sb, ce->e_value, REQ_PRIO);
3128 if (IS_ERR(bh)) {
3129 if (PTR_ERR(bh) == -ENOMEM)
3130 return NULL;
3131 bh = NULL;
3132 EXT4_ERROR_INODE(inode, "block %lu read error",
3133 (unsigned long)ce->e_value);
3134 } else if (ext4_xattr_cmp(header, BHDR(bh)) == 0) {
3135 *pce = ce;
3136 return bh;
3137 }
3138 brelse(bh);
3139 ce = mb_cache_entry_find_next(ea_block_cache, ce);
3140 }
3141 return NULL;
3142}
3143
3144#define NAME_HASH_SHIFT 5
3145#define VALUE_HASH_SHIFT 16
3146
3147/*
3148 * ext4_xattr_hash_entry()
3149 *
3150 * Compute the hash of an extended attribute.
3151 */
3152static __le32 ext4_xattr_hash_entry(char *name, size_t name_len, __le32 *value,
3153 size_t value_count)
3154{
3155 __u32 hash = 0;
3156
3157 while (name_len--) {
3158 hash = (hash << NAME_HASH_SHIFT) ^
3159 (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^
3160 (unsigned char)*name++;
3161 }
3162 while (value_count--) {
3163 hash = (hash << VALUE_HASH_SHIFT) ^
3164 (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^
3165 le32_to_cpu(*value++);
3166 }
3167 return cpu_to_le32(hash);
3168}
3169
3170/*
3171 * ext4_xattr_hash_entry_signed()
3172 *
3173 * Compute the hash of an extended attribute incorrectly.
3174 */
3175static __le32 ext4_xattr_hash_entry_signed(char *name, size_t name_len, __le32 *value, size_t value_count)
3176{
3177 __u32 hash = 0;
3178
3179 while (name_len--) {
3180 hash = (hash << NAME_HASH_SHIFT) ^
3181 (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^
3182 (signed char)*name++;
3183 }
3184 while (value_count--) {
3185 hash = (hash << VALUE_HASH_SHIFT) ^
3186 (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^
3187 le32_to_cpu(*value++);
3188 }
3189 return cpu_to_le32(hash);
3190}
3191
3192#undef NAME_HASH_SHIFT
3193#undef VALUE_HASH_SHIFT
3194
3195#define BLOCK_HASH_SHIFT 16
3196
3197/*
3198 * ext4_xattr_rehash()
3199 *
3200 * Re-compute the extended attribute hash value after an entry has changed.
3201 */
3202static void ext4_xattr_rehash(struct ext4_xattr_header *header)
3203{
3204 struct ext4_xattr_entry *here;
3205 __u32 hash = 0;
3206
3207 here = ENTRY(header+1);
3208 while (!IS_LAST_ENTRY(here)) {
3209 if (!here->e_hash) {
3210 /* Block is not shared if an entry's hash value == 0 */
3211 hash = 0;
3212 break;
3213 }
3214 hash = (hash << BLOCK_HASH_SHIFT) ^
3215 (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^
3216 le32_to_cpu(here->e_hash);
3217 here = EXT4_XATTR_NEXT(here);
3218 }
3219 header->h_hash = cpu_to_le32(hash);
3220}
3221
3222#undef BLOCK_HASH_SHIFT
3223
3224#define HASH_BUCKET_BITS 10
3225
3226struct mb_cache *
3227ext4_xattr_create_cache(void)
3228{
3229 return mb_cache_create(HASH_BUCKET_BITS);
3230}
3231
3232void ext4_xattr_destroy_cache(struct mb_cache *cache)
3233{
3234 if (cache)
3235 mb_cache_destroy(cache);
3236}
3237