Line data Source code
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 :
77 : static void ext4_xattr_block_cache_insert(struct mb_cache *,
78 : struct buffer_head *);
79 : static struct buffer_head *
80 : ext4_xattr_block_cache_find(struct inode *, struct ext4_xattr_header *,
81 : struct mb_cache_entry **);
82 : static __le32 ext4_xattr_hash_entry(char *name, size_t name_len, __le32 *value,
83 : size_t value_count);
84 : static __le32 ext4_xattr_hash_entry_signed(char *name, size_t name_len, __le32 *value,
85 : size_t value_count);
86 : static void ext4_xattr_rehash(struct ext4_xattr_header *);
87 :
88 : static 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 :
101 : const struct xattr_handler *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 :
117 : static int
118 : ext4_expand_inode_array(struct ext4_xattr_inode_array **ea_inode_array,
119 : struct inode *inode);
120 :
121 : #ifdef CONFIG_LOCKDEP
122 : void 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 :
132 0 : static __le32 ext4_xattr_block_csum(struct inode *inode,
133 : sector_t block_nr,
134 : struct ext4_xattr_header *hdr)
135 : {
136 0 : struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
137 0 : __u32 csum;
138 0 : __le64 dsk_block_nr = cpu_to_le64(block_nr);
139 0 : __u32 dummy_csum = 0;
140 0 : int offset = offsetof(struct ext4_xattr_header, h_checksum);
141 :
142 0 : csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&dsk_block_nr,
143 : sizeof(dsk_block_nr));
144 0 : csum = ext4_chksum(sbi, csum, (__u8 *)hdr, offset);
145 0 : csum = ext4_chksum(sbi, csum, (__u8 *)&dummy_csum, sizeof(dummy_csum));
146 0 : offset += sizeof(dummy_csum);
147 0 : csum = ext4_chksum(sbi, csum, (__u8 *)hdr + offset,
148 0 : EXT4_BLOCK_SIZE(inode->i_sb) - offset);
149 :
150 0 : return cpu_to_le32(csum);
151 : }
152 :
153 0 : static int ext4_xattr_block_csum_verify(struct inode *inode,
154 : struct buffer_head *bh)
155 : {
156 0 : struct ext4_xattr_header *hdr = BHDR(bh);
157 0 : int ret = 1;
158 :
159 0 : if (ext4_has_metadata_csum(inode->i_sb)) {
160 0 : lock_buffer(bh);
161 0 : ret = (hdr->h_checksum == ext4_xattr_block_csum(inode,
162 : bh->b_blocknr, hdr));
163 0 : unlock_buffer(bh);
164 : }
165 0 : return ret;
166 : }
167 :
168 0 : static void ext4_xattr_block_csum_set(struct inode *inode,
169 : struct buffer_head *bh)
170 : {
171 0 : if (ext4_has_metadata_csum(inode->i_sb))
172 0 : BHDR(bh)->h_checksum = ext4_xattr_block_csum(inode,
173 0 : bh->b_blocknr, BHDR(bh));
174 0 : }
175 :
176 0 : static inline const char *ext4_xattr_prefix(int name_index,
177 : struct dentry *dentry)
178 : {
179 0 : const struct xattr_handler *handler = NULL;
180 :
181 0 : if (name_index > 0 && name_index < ARRAY_SIZE(ext4_xattr_handler_map))
182 0 : handler = ext4_xattr_handler_map[name_index];
183 :
184 0 : if (!xattr_handler_can_list(handler, dentry))
185 : return NULL;
186 :
187 0 : return xattr_prefix(handler);
188 : }
189 :
190 : static int
191 0 : check_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 0 : struct ext4_xattr_entry *e = entry;
196 0 : int err = -EFSCORRUPTED;
197 0 : char *err_str;
198 :
199 0 : if (bh) {
200 0 : if (BHDR(bh)->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC) ||
201 0 : BHDR(bh)->h_blocks != cpu_to_le32(1)) {
202 0 : err_str = "invalid header";
203 0 : goto errout;
204 : }
205 0 : if (buffer_verified(bh))
206 : return 0;
207 0 : if (!ext4_xattr_block_csum_verify(inode, bh)) {
208 0 : err = -EFSBADCRC;
209 0 : err_str = "invalid checksum";
210 0 : goto errout;
211 : }
212 : } else {
213 0 : struct ext4_xattr_ibody_header *header = value_start;
214 :
215 0 : header -= 1;
216 0 : if (end - (void *)header < sizeof(*header) + sizeof(u32)) {
217 0 : err_str = "in-inode xattr block too small";
218 0 : goto errout;
219 : }
220 0 : if (header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC)) {
221 0 : err_str = "bad magic number in in-inode xattr";
222 0 : goto errout;
223 : }
224 : }
225 :
226 : /* Find the end of the names list */
227 0 : while (!IS_LAST_ENTRY(e)) {
228 0 : struct ext4_xattr_entry *next = EXT4_XATTR_NEXT(e);
229 0 : if ((void *)next >= end) {
230 0 : err_str = "e_name out of bounds";
231 0 : goto errout;
232 : }
233 0 : if (strnlen(e->e_name, e->e_name_len) != e->e_name_len) {
234 0 : err_str = "bad e_name length";
235 0 : goto errout;
236 : }
237 : e = next;
238 : }
239 :
240 : /* Check the values */
241 0 : while (!IS_LAST_ENTRY(entry)) {
242 0 : u32 size = le32_to_cpu(entry->e_value_size);
243 0 : unsigned long ea_ino = le32_to_cpu(entry->e_value_inum);
244 :
245 0 : if (!ext4_has_feature_ea_inode(inode->i_sb) && ea_ino) {
246 0 : err_str = "ea_inode specified without ea_inode feature enabled";
247 0 : goto errout;
248 : }
249 0 : if (ea_ino && ((ea_ino == EXT4_ROOT_INO) ||
250 : !ext4_valid_inum(inode->i_sb, ea_ino))) {
251 0 : err_str = "invalid ea_ino";
252 0 : goto errout;
253 : }
254 0 : if (size > EXT4_XATTR_SIZE_MAX) {
255 0 : err_str = "e_value size too large";
256 0 : goto errout;
257 : }
258 :
259 0 : if (size != 0 && entry->e_value_inum == 0) {
260 0 : u16 offs = le16_to_cpu(entry->e_value_offs);
261 0 : 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 0 : if (offs > end - value_start) {
270 0 : err_str = "e_value out of bounds";
271 0 : goto errout;
272 : }
273 0 : value = value_start + offs;
274 0 : if (value < (void *)e + sizeof(u32) ||
275 0 : size > end - value ||
276 0 : EXT4_XATTR_SIZE(size) > end - value) {
277 0 : err_str = "overlapping e_value ";
278 0 : goto errout;
279 : }
280 : }
281 0 : entry = EXT4_XATTR_NEXT(entry);
282 : }
283 0 : if (bh)
284 0 : set_buffer_verified(bh);
285 : return 0;
286 :
287 0 : errout:
288 0 : if (bh)
289 0 : __ext4_error_inode(inode, function, line, 0, -err,
290 : "corrupted xattr block %llu: %s",
291 0 : (unsigned long long) bh->b_blocknr,
292 : err_str);
293 : else
294 0 : __ext4_error_inode(inode, function, line, 0, -err,
295 : "corrupted in-inode xattr: %s", err_str);
296 : return err;
297 : }
298 :
299 : static inline int
300 0 : __ext4_xattr_check_block(struct inode *inode, struct buffer_head *bh,
301 : const char *function, unsigned int line)
302 : {
303 0 : 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 :
311 : static 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 0 : 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 :
322 : static int
323 0 : xattr_find_entry(struct inode *inode, struct ext4_xattr_entry **pentry,
324 : void *end, int name_index, const char *name, int sorted)
325 : {
326 0 : struct ext4_xattr_entry *entry, *next;
327 0 : size_t name_len;
328 0 : int cmp = 1;
329 :
330 0 : if (name == NULL)
331 : return -EINVAL;
332 0 : name_len = strlen(name);
333 0 : for (entry = *pentry; !IS_LAST_ENTRY(entry); entry = next) {
334 0 : next = EXT4_XATTR_NEXT(entry);
335 0 : if ((void *) next >= end) {
336 0 : EXT4_ERROR_INODE(inode, "corrupted xattr entries");
337 0 : return -EFSCORRUPTED;
338 : }
339 0 : cmp = name_index - entry->e_name_index;
340 0 : if (!cmp)
341 0 : cmp = name_len - entry->e_name_len;
342 0 : if (!cmp)
343 0 : cmp = memcmp(name, entry->e_name, name_len);
344 0 : if (cmp <= 0 && (sorted || cmp == 0))
345 : break;
346 : }
347 0 : *pentry = entry;
348 0 : return cmp ? -ENODATA : 0;
349 : }
350 :
351 : static u32
352 : ext4_xattr_inode_hash(struct ext4_sb_info *sbi, const void *buffer, size_t size)
353 : {
354 0 : return ext4_chksum(sbi, sbi->s_csum_seed, buffer, size);
355 : }
356 :
357 : static u64 ext4_xattr_inode_get_ref(struct inode *ea_inode)
358 : {
359 0 : return ((u64)ea_inode->i_ctime.tv_sec << 32) |
360 : (u32) inode_peek_iversion_raw(ea_inode);
361 : }
362 :
363 : static void ext4_xattr_inode_set_ref(struct inode *ea_inode, u64 ref_count)
364 : {
365 0 : ea_inode->i_ctime.tv_sec = (u32)(ref_count >> 32);
366 0 : inode_set_iversion_raw(ea_inode, ref_count & 0xffffffff);
367 0 : }
368 :
369 : static u32 ext4_xattr_inode_get_hash(struct inode *ea_inode)
370 : {
371 0 : return (u32)ea_inode->i_atime.tv_sec;
372 : }
373 :
374 : static void ext4_xattr_inode_set_hash(struct inode *ea_inode, u32 hash)
375 : {
376 0 : ea_inode->i_atime.tv_sec = hash;
377 : }
378 :
379 : /*
380 : * Read the EA value from an inode.
381 : */
382 0 : static int ext4_xattr_inode_read(struct inode *ea_inode, void *buf, size_t size)
383 : {
384 0 : int blocksize = 1 << ea_inode->i_blkbits;
385 0 : int bh_count = (size + blocksize - 1) >> ea_inode->i_blkbits;
386 0 : int tail_size = (size % blocksize) ?: blocksize;
387 0 : struct buffer_head *bhs_inline[8];
388 0 : struct buffer_head **bhs = bhs_inline;
389 0 : int i, ret;
390 :
391 0 : if (bh_count > ARRAY_SIZE(bhs_inline)) {
392 0 : bhs = kmalloc_array(bh_count, sizeof(*bhs), GFP_NOFS);
393 0 : if (!bhs)
394 : return -ENOMEM;
395 : }
396 :
397 0 : ret = ext4_bread_batch(ea_inode, 0 /* block */, bh_count,
398 : true /* wait */, bhs);
399 0 : if (ret)
400 0 : goto free_bhs;
401 :
402 0 : for (i = 0; i < bh_count; i++) {
403 : /* There shouldn't be any holes in ea_inode. */
404 0 : if (!bhs[i]) {
405 0 : ret = -EFSCORRUPTED;
406 0 : goto put_bhs;
407 : }
408 0 : memcpy((char *)buf + blocksize * i, bhs[i]->b_data,
409 : i < bh_count - 1 ? blocksize : tail_size);
410 : }
411 : ret = 0;
412 0 : put_bhs:
413 0 : for (i = 0; i < bh_count; i++)
414 0 : brelse(bhs[i]);
415 0 : free_bhs:
416 0 : if (bhs != bhs_inline)
417 0 : kfree(bhs);
418 : return ret;
419 : }
420 :
421 : #define EXT4_XATTR_INODE_GET_PARENT(inode) ((__u32)(inode)->i_mtime.tv_sec)
422 :
423 0 : static int ext4_xattr_inode_iget(struct inode *parent, unsigned long ea_ino,
424 : u32 ea_inode_hash, struct inode **ea_inode)
425 : {
426 0 : struct inode *inode;
427 0 : 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 0 : if (parent->i_ino == ea_ino) {
435 0 : ext4_error(parent->i_sb,
436 : "Parent and EA inode have the same ino %lu", ea_ino);
437 0 : return -EFSCORRUPTED;
438 : }
439 :
440 0 : inode = ext4_iget(parent->i_sb, ea_ino, EXT4_IGET_EA_INODE);
441 0 : if (IS_ERR(inode)) {
442 0 : err = PTR_ERR(inode);
443 0 : ext4_error(parent->i_sb,
444 : "error while reading EA inode %lu err=%d", ea_ino,
445 : err);
446 0 : return err;
447 : }
448 0 : 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 0 : if (ea_inode_hash != ext4_xattr_inode_get_hash(inode) &&
456 0 : EXT4_XATTR_INODE_GET_PARENT(inode) == parent->i_ino &&
457 0 : inode->i_generation == parent->i_generation) {
458 0 : ext4_set_inode_state(inode, EXT4_STATE_LUSTRE_EA_INODE);
459 0 : ext4_xattr_inode_set_ref(inode, 1);
460 : } else {
461 0 : inode_lock(inode);
462 0 : inode->i_flags |= S_NOQUOTA;
463 0 : inode_unlock(inode);
464 : }
465 :
466 0 : *ea_inode = inode;
467 0 : return 0;
468 : }
469 :
470 : /* Remove entry from mbcache when EA inode is getting evicted */
471 0 : void ext4_evict_ea_inode(struct inode *inode)
472 : {
473 0 : struct mb_cache_entry *oe;
474 :
475 0 : if (!EA_INODE_CACHE(inode))
476 : return;
477 : /* Wait for entry to get unused so that we can remove it */
478 0 : while ((oe = mb_cache_entry_delete_or_get(EA_INODE_CACHE(inode),
479 0 : ext4_xattr_inode_get_hash(inode), inode->i_ino))) {
480 0 : mb_cache_entry_wait_unused(oe);
481 0 : mb_cache_entry_put(EA_INODE_CACHE(inode), oe);
482 : }
483 : }
484 :
485 : static int
486 0 : ext4_xattr_inode_verify_hashes(struct inode *ea_inode,
487 : struct ext4_xattr_entry *entry, void *buffer,
488 : size_t size)
489 : {
490 0 : u32 hash;
491 :
492 : /* Verify stored hash matches calculated hash. */
493 0 : hash = ext4_xattr_inode_hash(EXT4_SB(ea_inode->i_sb), buffer, size);
494 0 : if (hash != ext4_xattr_inode_get_hash(ea_inode))
495 : return -EFSCORRUPTED;
496 :
497 0 : if (entry) {
498 0 : __le32 e_hash, tmp_data;
499 :
500 : /* Verify entry hash. */
501 0 : tmp_data = cpu_to_le32(hash);
502 0 : e_hash = ext4_xattr_hash_entry(entry->e_name, entry->e_name_len,
503 : &tmp_data, 1);
504 : /* All good? */
505 0 : if (e_hash == entry->e_hash)
506 0 : return 0;
507 :
508 : /*
509 : * Not good. Maybe the entry hash was calculated
510 : * using the buggy signed char version?
511 : */
512 0 : e_hash = ext4_xattr_hash_entry_signed(entry->e_name, entry->e_name_len,
513 : &tmp_data, 1);
514 : /* Still no match - bad */
515 0 : if (e_hash != entry->e_hash)
516 : return -EFSCORRUPTED;
517 :
518 : /* Let people know about old hash */
519 0 : 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 : */
527 : static int
528 0 : ext4_xattr_inode_get(struct inode *inode, struct ext4_xattr_entry *entry,
529 : void *buffer, size_t size)
530 : {
531 0 : struct mb_cache *ea_inode_cache = EA_INODE_CACHE(inode);
532 0 : struct inode *ea_inode;
533 0 : int err;
534 :
535 0 : err = ext4_xattr_inode_iget(inode, le32_to_cpu(entry->e_value_inum),
536 0 : le32_to_cpu(entry->e_hash), &ea_inode);
537 0 : if (err) {
538 0 : ea_inode = NULL;
539 0 : goto out;
540 : }
541 :
542 0 : if (i_size_read(ea_inode) != size) {
543 0 : ext4_warning_inode(ea_inode,
544 : "ea_inode file size=%llu entry size=%zu",
545 : i_size_read(ea_inode), size);
546 0 : err = -EFSCORRUPTED;
547 0 : goto out;
548 : }
549 :
550 0 : err = ext4_xattr_inode_read(ea_inode, buffer, size);
551 0 : if (err)
552 0 : goto out;
553 :
554 0 : if (!ext4_test_inode_state(ea_inode, EXT4_STATE_LUSTRE_EA_INODE)) {
555 0 : err = ext4_xattr_inode_verify_hashes(ea_inode, entry, buffer,
556 : size);
557 0 : if (err) {
558 0 : ext4_warning_inode(ea_inode,
559 : "EA inode hash validation failed");
560 0 : goto out;
561 : }
562 :
563 0 : if (ea_inode_cache)
564 0 : mb_cache_entry_create(ea_inode_cache, GFP_NOFS,
565 : ext4_xattr_inode_get_hash(ea_inode),
566 0 : ea_inode->i_ino, true /* reusable */);
567 : }
568 0 : out:
569 0 : iput(ea_inode);
570 0 : return err;
571 : }
572 :
573 : static int
574 0 : ext4_xattr_block_get(struct inode *inode, int name_index, const char *name,
575 : void *buffer, size_t buffer_size)
576 : {
577 0 : struct buffer_head *bh = NULL;
578 0 : struct ext4_xattr_entry *entry;
579 0 : size_t size;
580 0 : void *end;
581 0 : int error;
582 0 : struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
583 :
584 0 : ea_idebug(inode, "name=%d.%s, buffer=%p, buffer_size=%ld",
585 : name_index, name, buffer, (long)buffer_size);
586 :
587 0 : if (!EXT4_I(inode)->i_file_acl)
588 : return -ENODATA;
589 0 : ea_idebug(inode, "reading block %llu",
590 : (unsigned long long)EXT4_I(inode)->i_file_acl);
591 0 : bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
592 0 : if (IS_ERR(bh))
593 0 : return PTR_ERR(bh);
594 0 : ea_bdebug(bh, "b_count=%d, refcount=%d",
595 : atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount));
596 0 : error = ext4_xattr_check_block(inode, bh);
597 0 : if (error)
598 0 : goto cleanup;
599 0 : ext4_xattr_block_cache_insert(ea_block_cache, bh);
600 0 : entry = BFIRST(bh);
601 0 : end = bh->b_data + bh->b_size;
602 0 : error = xattr_find_entry(inode, &entry, end, name_index, name, 1);
603 0 : if (error)
604 0 : goto cleanup;
605 0 : size = le32_to_cpu(entry->e_value_size);
606 0 : error = -ERANGE;
607 0 : if (unlikely(size > EXT4_XATTR_SIZE_MAX))
608 0 : goto cleanup;
609 0 : if (buffer) {
610 0 : if (size > buffer_size)
611 0 : goto cleanup;
612 0 : if (entry->e_value_inum) {
613 0 : error = ext4_xattr_inode_get(inode, entry, buffer,
614 : size);
615 0 : if (error)
616 0 : goto cleanup;
617 : } else {
618 0 : u16 offset = le16_to_cpu(entry->e_value_offs);
619 0 : void *p = bh->b_data + offset;
620 :
621 0 : if (unlikely(p + size > end))
622 0 : goto cleanup;
623 0 : memcpy(buffer, p, size);
624 : }
625 : }
626 0 : error = size;
627 :
628 0 : cleanup:
629 0 : brelse(bh);
630 : return error;
631 : }
632 :
633 : int
634 0 : ext4_xattr_ibody_get(struct inode *inode, int name_index, const char *name,
635 : void *buffer, size_t buffer_size)
636 : {
637 0 : struct ext4_xattr_ibody_header *header;
638 0 : struct ext4_xattr_entry *entry;
639 0 : struct ext4_inode *raw_inode;
640 0 : struct ext4_iloc iloc;
641 0 : size_t size;
642 0 : void *end;
643 0 : int error;
644 :
645 0 : if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR))
646 : return -ENODATA;
647 0 : error = ext4_get_inode_loc(inode, &iloc);
648 0 : if (error)
649 : return error;
650 0 : raw_inode = ext4_raw_inode(&iloc);
651 0 : header = IHDR(inode, raw_inode);
652 0 : end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
653 0 : error = xattr_check_inode(inode, header, end);
654 0 : if (error)
655 0 : goto cleanup;
656 0 : entry = IFIRST(header);
657 0 : error = xattr_find_entry(inode, &entry, end, name_index, name, 0);
658 0 : if (error)
659 0 : goto cleanup;
660 0 : size = le32_to_cpu(entry->e_value_size);
661 0 : error = -ERANGE;
662 0 : if (unlikely(size > EXT4_XATTR_SIZE_MAX))
663 0 : goto cleanup;
664 0 : if (buffer) {
665 0 : if (size > buffer_size)
666 0 : goto cleanup;
667 0 : if (entry->e_value_inum) {
668 0 : error = ext4_xattr_inode_get(inode, entry, buffer,
669 : size);
670 0 : if (error)
671 0 : goto cleanup;
672 : } else {
673 0 : u16 offset = le16_to_cpu(entry->e_value_offs);
674 0 : void *p = (void *)IFIRST(header) + offset;
675 :
676 0 : if (unlikely(p + size > end))
677 0 : goto cleanup;
678 0 : memcpy(buffer, p, size);
679 : }
680 : }
681 0 : error = size;
682 :
683 0 : cleanup:
684 0 : 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 : */
698 : int
699 0 : ext4_xattr_get(struct inode *inode, int name_index, const char *name,
700 : void *buffer, size_t buffer_size)
701 : {
702 0 : int error;
703 :
704 0 : if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
705 : return -EIO;
706 :
707 0 : if (strlen(name) > 255)
708 : return -ERANGE;
709 :
710 0 : down_read(&EXT4_I(inode)->xattr_sem);
711 0 : error = ext4_xattr_ibody_get(inode, name_index, name, buffer,
712 : buffer_size);
713 0 : if (error == -ENODATA)
714 0 : error = ext4_xattr_block_get(inode, name_index, name, buffer,
715 : buffer_size);
716 0 : up_read(&EXT4_I(inode)->xattr_sem);
717 0 : return error;
718 : }
719 :
720 : static int
721 0 : ext4_xattr_list_entries(struct dentry *dentry, struct ext4_xattr_entry *entry,
722 : char *buffer, size_t buffer_size)
723 : {
724 0 : size_t rest = buffer_size;
725 :
726 0 : for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) {
727 0 : const char *prefix;
728 :
729 0 : prefix = ext4_xattr_prefix(entry->e_name_index, dentry);
730 0 : if (prefix) {
731 0 : size_t prefix_len = strlen(prefix);
732 0 : size_t size = prefix_len + entry->e_name_len + 1;
733 :
734 0 : if (buffer) {
735 0 : if (size > rest)
736 : return -ERANGE;
737 0 : memcpy(buffer, prefix, prefix_len);
738 0 : buffer += prefix_len;
739 0 : memcpy(buffer, entry->e_name, entry->e_name_len);
740 0 : buffer += entry->e_name_len;
741 0 : *buffer++ = 0;
742 : }
743 0 : rest -= size;
744 : }
745 : }
746 0 : return buffer_size - rest; /* total size */
747 : }
748 :
749 : static int
750 0 : ext4_xattr_block_list(struct dentry *dentry, char *buffer, size_t buffer_size)
751 : {
752 0 : struct inode *inode = d_inode(dentry);
753 0 : struct buffer_head *bh = NULL;
754 0 : int error;
755 :
756 0 : ea_idebug(inode, "buffer=%p, buffer_size=%ld",
757 : buffer, (long)buffer_size);
758 :
759 0 : if (!EXT4_I(inode)->i_file_acl)
760 : return 0;
761 0 : ea_idebug(inode, "reading block %llu",
762 : (unsigned long long)EXT4_I(inode)->i_file_acl);
763 0 : bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
764 0 : if (IS_ERR(bh))
765 0 : return PTR_ERR(bh);
766 0 : ea_bdebug(bh, "b_count=%d, refcount=%d",
767 : atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount));
768 0 : error = ext4_xattr_check_block(inode, bh);
769 0 : if (error)
770 0 : goto cleanup;
771 0 : ext4_xattr_block_cache_insert(EA_BLOCK_CACHE(inode), bh);
772 0 : error = ext4_xattr_list_entries(dentry, BFIRST(bh), buffer,
773 : buffer_size);
774 0 : cleanup:
775 0 : brelse(bh);
776 : return error;
777 : }
778 :
779 : static int
780 0 : ext4_xattr_ibody_list(struct dentry *dentry, char *buffer, size_t buffer_size)
781 : {
782 0 : struct inode *inode = d_inode(dentry);
783 0 : struct ext4_xattr_ibody_header *header;
784 0 : struct ext4_inode *raw_inode;
785 0 : struct ext4_iloc iloc;
786 0 : void *end;
787 0 : int error;
788 :
789 0 : if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR))
790 : return 0;
791 0 : error = ext4_get_inode_loc(inode, &iloc);
792 0 : if (error)
793 : return error;
794 0 : raw_inode = ext4_raw_inode(&iloc);
795 0 : header = IHDR(inode, raw_inode);
796 0 : end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
797 0 : error = xattr_check_inode(inode, header, end);
798 0 : if (error)
799 0 : goto cleanup;
800 0 : error = ext4_xattr_list_entries(dentry, IFIRST(header),
801 : buffer, buffer_size);
802 :
803 0 : cleanup:
804 0 : 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 : */
820 : ssize_t
821 0 : ext4_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
822 : {
823 0 : int ret, ret2;
824 :
825 0 : down_read(&EXT4_I(d_inode(dentry))->xattr_sem);
826 0 : ret = ret2 = ext4_xattr_ibody_list(dentry, buffer, buffer_size);
827 0 : if (ret < 0)
828 0 : goto errout;
829 0 : if (buffer) {
830 0 : buffer += ret;
831 0 : buffer_size -= ret;
832 : }
833 0 : ret = ext4_xattr_block_list(dentry, buffer, buffer_size);
834 0 : if (ret < 0)
835 0 : goto errout;
836 0 : ret += ret2;
837 0 : errout:
838 0 : up_read(&EXT4_I(d_inode(dentry))->xattr_sem);
839 0 : 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 : */
846 0 : static void ext4_xattr_update_super_block(handle_t *handle,
847 : struct super_block *sb)
848 : {
849 0 : if (ext4_has_feature_xattr(sb))
850 : return;
851 :
852 0 : BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access");
853 0 : if (ext4_journal_get_write_access(handle, sb, EXT4_SB(sb)->s_sbh,
854 : EXT4_JTR_NONE) == 0) {
855 0 : lock_buffer(EXT4_SB(sb)->s_sbh);
856 0 : ext4_set_feature_xattr(sb);
857 0 : ext4_superblock_csum_set(sb);
858 0 : unlock_buffer(EXT4_SB(sb)->s_sbh);
859 0 : ext4_handle_dirty_metadata(handle, NULL, EXT4_SB(sb)->s_sbh);
860 : }
861 : }
862 :
863 0 : int ext4_get_inode_usage(struct inode *inode, qsize_t *usage)
864 : {
865 0 : struct ext4_iloc iloc = { .bh = NULL };
866 0 : struct buffer_head *bh = NULL;
867 0 : struct ext4_inode *raw_inode;
868 0 : struct ext4_xattr_ibody_header *header;
869 0 : struct ext4_xattr_entry *entry;
870 0 : qsize_t ea_inode_refs = 0;
871 0 : void *end;
872 0 : int ret;
873 :
874 0 : lockdep_assert_held_read(&EXT4_I(inode)->xattr_sem);
875 :
876 0 : if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
877 0 : ret = ext4_get_inode_loc(inode, &iloc);
878 0 : if (ret)
879 0 : goto out;
880 0 : raw_inode = ext4_raw_inode(&iloc);
881 0 : header = IHDR(inode, raw_inode);
882 0 : end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
883 0 : ret = xattr_check_inode(inode, header, end);
884 0 : if (ret)
885 0 : goto out;
886 :
887 0 : for (entry = IFIRST(header); !IS_LAST_ENTRY(entry);
888 0 : entry = EXT4_XATTR_NEXT(entry))
889 0 : if (entry->e_value_inum)
890 0 : ea_inode_refs++;
891 : }
892 :
893 0 : if (EXT4_I(inode)->i_file_acl) {
894 0 : bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
895 0 : if (IS_ERR(bh)) {
896 0 : ret = PTR_ERR(bh);
897 0 : bh = NULL;
898 0 : goto out;
899 : }
900 :
901 0 : ret = ext4_xattr_check_block(inode, bh);
902 0 : if (ret)
903 0 : goto out;
904 :
905 0 : for (entry = BFIRST(bh); !IS_LAST_ENTRY(entry);
906 0 : entry = EXT4_XATTR_NEXT(entry))
907 0 : if (entry->e_value_inum)
908 0 : ea_inode_refs++;
909 : }
910 0 : *usage = ea_inode_refs + 1;
911 0 : ret = 0;
912 0 : out:
913 0 : brelse(iloc.bh);
914 0 : brelse(bh);
915 0 : return ret;
916 : }
917 :
918 : static inline size_t round_up_cluster(struct inode *inode, size_t length)
919 : {
920 0 : struct super_block *sb = inode->i_sb;
921 0 : size_t cluster_size = 1 << (EXT4_SB(sb)->s_cluster_bits +
922 0 : inode->i_blkbits);
923 0 : size_t mask = ~(cluster_size - 1);
924 :
925 0 : return (length + cluster_size - 1) & mask;
926 : }
927 :
928 0 : static int ext4_xattr_inode_alloc_quota(struct inode *inode, size_t len)
929 : {
930 0 : int err;
931 :
932 0 : err = dquot_alloc_inode(inode);
933 0 : if (err)
934 : return err;
935 0 : err = dquot_alloc_space_nodirty(inode, round_up_cluster(inode, len));
936 0 : if (err)
937 0 : dquot_free_inode(inode);
938 : return err;
939 : }
940 :
941 0 : static void ext4_xattr_inode_free_quota(struct inode *parent,
942 : struct inode *ea_inode,
943 : size_t len)
944 : {
945 0 : if (ea_inode &&
946 : ext4_test_inode_state(ea_inode, EXT4_STATE_LUSTRE_EA_INODE))
947 : return;
948 0 : dquot_free_space_nodirty(parent, round_up_cluster(parent, len));
949 0 : dquot_free_inode(parent);
950 : }
951 :
952 0 : int __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 0 : int credits;
957 0 : 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 0 : credits = 7;
973 :
974 : /* Quota updates. */
975 0 : 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 0 : if (inode && ext4_has_inline_data(inode))
982 0 : credits += ext4_writepage_trans_blocks(inode) + 1;
983 :
984 : /* We are done if ea_inode feature is not enabled. */
985 0 : if (!ext4_has_feature_ea_inode(sb))
986 : return credits;
987 :
988 : /* New ea_inode, inode map, block bitmap, group descriptor. */
989 0 : credits += 4;
990 :
991 : /* Data blocks. */
992 0 : blocks = (value_len + sb->s_blocksize - 1) >> sb->s_blocksize_bits;
993 :
994 : /* Indirection block or one level of extent tree. */
995 0 : blocks += 1;
996 :
997 : /* Block bitmap and group descriptor updates for each block. */
998 0 : credits += blocks * 2;
999 :
1000 : /* Blocks themselves. */
1001 0 : credits += blocks;
1002 :
1003 0 : if (!is_create) {
1004 : /* Dereference ea_inode holding old xattr value.
1005 : * Old ea_inode, inode map, block bitmap, group descriptor.
1006 : */
1007 0 : credits += 4;
1008 :
1009 : /* Data blocks for old ea_inode. */
1010 0 : 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 0 : blocks += 1;
1016 :
1017 : /* Block bitmap and group descriptor updates for each block. */
1018 0 : 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 0 : if (block_bh) {
1025 0 : struct ext4_xattr_entry *entry = BFIRST(block_bh);
1026 :
1027 0 : for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry))
1028 0 : if (entry->e_value_inum)
1029 : /* Ref count update on ea_inode. */
1030 0 : credits += 1;
1031 : }
1032 : return credits;
1033 : }
1034 :
1035 0 : static int ext4_xattr_inode_update_ref(handle_t *handle, struct inode *ea_inode,
1036 : int ref_change)
1037 : {
1038 0 : struct ext4_iloc iloc;
1039 0 : s64 ref_count;
1040 0 : int ret;
1041 :
1042 0 : inode_lock(ea_inode);
1043 :
1044 0 : ret = ext4_reserve_inode_write(handle, ea_inode, &iloc);
1045 0 : if (ret)
1046 0 : goto out;
1047 :
1048 0 : ref_count = ext4_xattr_inode_get_ref(ea_inode);
1049 0 : ref_count += ref_change;
1050 0 : ext4_xattr_inode_set_ref(ea_inode, ref_count);
1051 :
1052 0 : if (ref_change > 0) {
1053 0 : WARN_ONCE(ref_count <= 0, "EA inode %lu ref_count=%lld",
1054 : ea_inode->i_ino, ref_count);
1055 :
1056 0 : if (ref_count == 1) {
1057 0 : WARN_ONCE(ea_inode->i_nlink, "EA inode %lu i_nlink=%u",
1058 : ea_inode->i_ino, ea_inode->i_nlink);
1059 :
1060 0 : set_nlink(ea_inode, 1);
1061 0 : ext4_orphan_del(handle, ea_inode);
1062 : }
1063 : } else {
1064 0 : WARN_ONCE(ref_count < 0, "EA inode %lu ref_count=%lld",
1065 : ea_inode->i_ino, ref_count);
1066 :
1067 0 : if (ref_count == 0) {
1068 0 : 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 0 : clear_nlink(ea_inode);
1073 0 : ext4_orphan_add(handle, ea_inode);
1074 : }
1075 : }
1076 :
1077 0 : ret = ext4_mark_iloc_dirty(handle, ea_inode, &iloc);
1078 0 : if (ret)
1079 0 : ext4_warning_inode(ea_inode,
1080 : "ext4_mark_iloc_dirty() failed ret=%d", ret);
1081 0 : out:
1082 0 : inode_unlock(ea_inode);
1083 0 : return ret;
1084 : }
1085 :
1086 : static int ext4_xattr_inode_inc_ref(handle_t *handle, struct inode *ea_inode)
1087 : {
1088 0 : return ext4_xattr_inode_update_ref(handle, ea_inode, 1);
1089 : }
1090 :
1091 : static int ext4_xattr_inode_dec_ref(handle_t *handle, struct inode *ea_inode)
1092 : {
1093 0 : return ext4_xattr_inode_update_ref(handle, ea_inode, -1);
1094 : }
1095 :
1096 0 : static int ext4_xattr_inode_inc_ref_all(handle_t *handle, struct inode *parent,
1097 : struct ext4_xattr_entry *first)
1098 : {
1099 0 : struct inode *ea_inode;
1100 0 : struct ext4_xattr_entry *entry;
1101 0 : struct ext4_xattr_entry *failed_entry;
1102 0 : unsigned int ea_ino;
1103 0 : int err, saved_err;
1104 :
1105 0 : for (entry = first; !IS_LAST_ENTRY(entry);
1106 0 : entry = EXT4_XATTR_NEXT(entry)) {
1107 0 : if (!entry->e_value_inum)
1108 0 : continue;
1109 0 : ea_ino = le32_to_cpu(entry->e_value_inum);
1110 0 : err = ext4_xattr_inode_iget(parent, ea_ino,
1111 0 : le32_to_cpu(entry->e_hash),
1112 : &ea_inode);
1113 0 : if (err)
1114 0 : goto cleanup;
1115 0 : err = ext4_xattr_inode_inc_ref(handle, ea_inode);
1116 0 : if (err) {
1117 0 : ext4_warning_inode(ea_inode, "inc ref error %d", err);
1118 0 : iput(ea_inode);
1119 0 : goto cleanup;
1120 : }
1121 0 : iput(ea_inode);
1122 : }
1123 : return 0;
1124 :
1125 0 : cleanup:
1126 0 : saved_err = err;
1127 0 : failed_entry = entry;
1128 :
1129 0 : for (entry = first; entry != failed_entry;
1130 0 : entry = EXT4_XATTR_NEXT(entry)) {
1131 0 : if (!entry->e_value_inum)
1132 0 : continue;
1133 0 : ea_ino = le32_to_cpu(entry->e_value_inum);
1134 0 : err = ext4_xattr_inode_iget(parent, ea_ino,
1135 0 : le32_to_cpu(entry->e_hash),
1136 : &ea_inode);
1137 0 : if (err) {
1138 0 : ext4_warning(parent->i_sb,
1139 : "cleanup ea_ino %u iget error %d", ea_ino,
1140 : err);
1141 0 : continue;
1142 : }
1143 0 : err = ext4_xattr_inode_dec_ref(handle, ea_inode);
1144 0 : if (err)
1145 0 : ext4_warning_inode(ea_inode, "cleanup dec ref error %d",
1146 : err);
1147 0 : iput(ea_inode);
1148 : }
1149 : return saved_err;
1150 : }
1151 :
1152 0 : static int ext4_xattr_restart_fn(handle_t *handle, struct inode *inode,
1153 : struct buffer_head *bh, bool block_csum, bool dirty)
1154 : {
1155 0 : int error;
1156 :
1157 0 : if (bh && dirty) {
1158 0 : if (block_csum)
1159 0 : ext4_xattr_block_csum_set(inode, bh);
1160 0 : error = ext4_handle_dirty_metadata(handle, NULL, bh);
1161 0 : if (error) {
1162 0 : ext4_warning(inode->i_sb, "Handle metadata (error %d)",
1163 : error);
1164 0 : return error;
1165 : }
1166 : }
1167 : return 0;
1168 : }
1169 :
1170 : static void
1171 0 : ext4_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 0 : struct inode *ea_inode;
1178 0 : struct ext4_xattr_entry *entry;
1179 0 : bool dirty = false;
1180 0 : unsigned int ea_ino;
1181 0 : int err;
1182 0 : int credits;
1183 :
1184 : /* One credit for dec ref on ea_inode, one for orphan list addition, */
1185 0 : credits = 2 + extra_credits;
1186 :
1187 0 : for (entry = first; !IS_LAST_ENTRY(entry);
1188 0 : entry = EXT4_XATTR_NEXT(entry)) {
1189 0 : if (!entry->e_value_inum)
1190 0 : continue;
1191 0 : ea_ino = le32_to_cpu(entry->e_value_inum);
1192 0 : err = ext4_xattr_inode_iget(parent, ea_ino,
1193 0 : le32_to_cpu(entry->e_hash),
1194 : &ea_inode);
1195 0 : if (err)
1196 0 : continue;
1197 :
1198 0 : err = ext4_expand_inode_array(ea_inode_array, ea_inode);
1199 0 : if (err) {
1200 0 : ext4_warning_inode(ea_inode,
1201 : "Expand inode array err=%d", err);
1202 0 : iput(ea_inode);
1203 0 : continue;
1204 : }
1205 :
1206 0 : 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 0 : if (err < 0) {
1211 0 : ext4_warning_inode(ea_inode, "Ensure credits err=%d",
1212 : err);
1213 0 : continue;
1214 : }
1215 0 : if (err > 0) {
1216 0 : err = ext4_journal_get_write_access(handle,
1217 : parent->i_sb, bh, EXT4_JTR_NONE);
1218 0 : if (err) {
1219 0 : ext4_warning_inode(ea_inode,
1220 : "Re-get write access err=%d",
1221 : err);
1222 0 : continue;
1223 : }
1224 : }
1225 :
1226 0 : err = ext4_xattr_inode_dec_ref(handle, ea_inode);
1227 0 : if (err) {
1228 0 : ext4_warning_inode(ea_inode, "ea_inode dec ref err=%d",
1229 : err);
1230 0 : continue;
1231 : }
1232 :
1233 0 : if (!skip_quota)
1234 0 : ext4_xattr_inode_free_quota(parent, ea_inode,
1235 0 : 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 0 : entry->e_value_inum = 0;
1244 0 : entry->e_value_size = 0;
1245 :
1246 0 : dirty = true;
1247 : }
1248 :
1249 0 : 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 0 : err = ext4_handle_dirty_metadata(handle, NULL, bh);
1257 0 : if (err)
1258 0 : ext4_warning_inode(parent,
1259 : "handle dirty metadata err=%d", err);
1260 : }
1261 0 : }
1262 :
1263 : /*
1264 : * Release the xattr block BH: If the reference count is > 1, decrement it;
1265 : * otherwise free the block.
1266 : */
1267 : static void
1268 0 : ext4_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 0 : struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
1274 0 : u32 hash, ref;
1275 0 : int error = 0;
1276 :
1277 0 : BUFFER_TRACE(bh, "get_write_access");
1278 0 : error = ext4_journal_get_write_access(handle, inode->i_sb, bh,
1279 : EXT4_JTR_NONE);
1280 0 : if (error)
1281 0 : goto out;
1282 :
1283 0 : retry_ref:
1284 0 : lock_buffer(bh);
1285 0 : hash = le32_to_cpu(BHDR(bh)->h_hash);
1286 0 : ref = le32_to_cpu(BHDR(bh)->h_refcount);
1287 0 : if (ref == 1) {
1288 0 : 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 0 : if (ea_block_cache) {
1294 0 : struct mb_cache_entry *oe;
1295 :
1296 0 : oe = mb_cache_entry_delete_or_get(ea_block_cache, hash,
1297 : bh->b_blocknr);
1298 0 : if (oe) {
1299 0 : unlock_buffer(bh);
1300 0 : mb_cache_entry_wait_unused(oe);
1301 0 : mb_cache_entry_put(ea_block_cache, oe);
1302 0 : goto retry_ref;
1303 : }
1304 : }
1305 0 : get_bh(bh);
1306 0 : unlock_buffer(bh);
1307 :
1308 0 : if (ext4_has_feature_ea_inode(inode->i_sb))
1309 0 : ext4_xattr_inode_dec_ref_all(handle, inode, bh,
1310 0 : BFIRST(bh),
1311 : true /* block_csum */,
1312 : ea_inode_array,
1313 : extra_credits,
1314 : true /* skip_quota */);
1315 0 : ext4_free_blocks(handle, inode, bh, 0, 1,
1316 : EXT4_FREE_BLOCKS_METADATA |
1317 : EXT4_FREE_BLOCKS_FORGET);
1318 : } else {
1319 0 : ref--;
1320 0 : BHDR(bh)->h_refcount = cpu_to_le32(ref);
1321 0 : if (ref == EXT4_XATTR_REFCOUNT_MAX - 1) {
1322 0 : struct mb_cache_entry *ce;
1323 :
1324 0 : if (ea_block_cache) {
1325 0 : ce = mb_cache_entry_get(ea_block_cache, hash,
1326 : bh->b_blocknr);
1327 0 : if (ce) {
1328 0 : set_bit(MBE_REUSABLE_B, &ce->e_flags);
1329 0 : mb_cache_entry_put(ea_block_cache, ce);
1330 : }
1331 : }
1332 : }
1333 :
1334 0 : 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 0 : if (ext4_handle_valid(handle))
1346 0 : error = ext4_handle_dirty_metadata(handle, inode, bh);
1347 0 : unlock_buffer(bh);
1348 0 : if (!ext4_handle_valid(handle))
1349 0 : error = ext4_handle_dirty_metadata(handle, inode, bh);
1350 0 : if (IS_SYNC(inode))
1351 0 : ext4_handle_sync(handle);
1352 0 : dquot_free_block(inode, EXT4_C2B(EXT4_SB(inode->i_sb), 1));
1353 0 : ea_bdebug(bh, "refcount now=%d; releasing",
1354 : le32_to_cpu(BHDR(bh)->h_refcount));
1355 : }
1356 0 : out:
1357 0 : ext4_std_error(inode->i_sb, error);
1358 0 : 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 : */
1365 0 : static size_t ext4_xattr_free_space(struct ext4_xattr_entry *last,
1366 : size_t *min_offs, void *base, int *total)
1367 : {
1368 0 : for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
1369 0 : if (!last->e_value_inum && last->e_value_size) {
1370 0 : size_t offs = le16_to_cpu(last->e_value_offs);
1371 0 : if (offs < *min_offs)
1372 0 : *min_offs = offs;
1373 : }
1374 0 : if (total)
1375 0 : *total += EXT4_XATTR_LEN(last->e_name_len);
1376 : }
1377 0 : return (*min_offs - ((void *)last - base) - sizeof(__u32));
1378 : }
1379 :
1380 : /*
1381 : * Write the value of the EA in an inode.
1382 : */
1383 0 : static int ext4_xattr_inode_write(handle_t *handle, struct inode *ea_inode,
1384 : const void *buf, int bufsize)
1385 : {
1386 0 : struct buffer_head *bh = NULL;
1387 0 : unsigned long block = 0;
1388 0 : int blocksize = ea_inode->i_sb->s_blocksize;
1389 0 : int max_blocks = (bufsize + blocksize - 1) >> ea_inode->i_blkbits;
1390 0 : int csize, wsize = 0;
1391 0 : int ret = 0, ret2 = 0;
1392 0 : int retries = 0;
1393 :
1394 : retry:
1395 0 : while (ret >= 0 && ret < max_blocks) {
1396 0 : struct ext4_map_blocks map;
1397 0 : map.m_lblk = block += ret;
1398 0 : map.m_len = max_blocks -= ret;
1399 :
1400 0 : ret = ext4_map_blocks(handle, ea_inode, &map,
1401 : EXT4_GET_BLOCKS_CREATE);
1402 0 : if (ret <= 0) {
1403 0 : ext4_mark_inode_dirty(handle, ea_inode);
1404 0 : if (ret == -ENOSPC &&
1405 0 : ext4_should_retry_alloc(ea_inode->i_sb, &retries)) {
1406 0 : ret = 0;
1407 0 : goto retry;
1408 : }
1409 0 : break;
1410 : }
1411 : }
1412 :
1413 0 : if (ret < 0)
1414 : return ret;
1415 :
1416 : block = 0;
1417 0 : while (wsize < bufsize) {
1418 0 : brelse(bh);
1419 0 : csize = (bufsize - wsize) > blocksize ? blocksize :
1420 : bufsize - wsize;
1421 0 : bh = ext4_getblk(handle, ea_inode, block, 0);
1422 0 : if (IS_ERR(bh))
1423 0 : return PTR_ERR(bh);
1424 0 : if (!bh) {
1425 0 : WARN_ON_ONCE(1);
1426 0 : EXT4_ERROR_INODE(ea_inode,
1427 : "ext4_getblk() return bh = NULL");
1428 0 : return -EFSCORRUPTED;
1429 : }
1430 0 : ret = ext4_journal_get_write_access(handle, ea_inode->i_sb, bh,
1431 : EXT4_JTR_NONE);
1432 0 : if (ret)
1433 0 : goto out;
1434 :
1435 0 : memcpy(bh->b_data, buf, csize);
1436 0 : set_buffer_uptodate(bh);
1437 0 : ext4_handle_dirty_metadata(handle, ea_inode, bh);
1438 :
1439 0 : buf += csize;
1440 0 : wsize += csize;
1441 0 : block += 1;
1442 : }
1443 :
1444 0 : inode_lock(ea_inode);
1445 0 : i_size_write(ea_inode, wsize);
1446 0 : ext4_update_i_disksize(ea_inode, wsize);
1447 0 : inode_unlock(ea_inode);
1448 :
1449 0 : ret2 = ext4_mark_inode_dirty(handle, ea_inode);
1450 0 : if (unlikely(ret2 && !ret))
1451 0 : ret = ret2;
1452 :
1453 0 : out:
1454 0 : brelse(bh);
1455 :
1456 : return ret;
1457 : }
1458 :
1459 : /*
1460 : * Create an inode to store the value of a large EA.
1461 : */
1462 0 : static struct inode *ext4_xattr_inode_create(handle_t *handle,
1463 : struct inode *inode, u32 hash)
1464 : {
1465 0 : struct inode *ea_inode = NULL;
1466 0 : uid_t owner[2] = { i_uid_read(inode), i_gid_read(inode) };
1467 0 : int err;
1468 :
1469 0 : if (inode->i_sb->s_root == NULL) {
1470 0 : ext4_warning(inode->i_sb,
1471 : "refuse to create EA inode when umounting");
1472 0 : WARN_ON(1);
1473 0 : 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 0 : 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 0 : if (!IS_ERR(ea_inode)) {
1484 0 : ea_inode->i_op = &ext4_file_inode_operations;
1485 0 : ea_inode->i_fop = &ext4_file_operations;
1486 0 : ext4_set_aops(ea_inode);
1487 0 : ext4_xattr_inode_set_class(ea_inode);
1488 0 : unlock_new_inode(ea_inode);
1489 0 : ext4_xattr_inode_set_ref(ea_inode, 1);
1490 0 : ext4_xattr_inode_set_hash(ea_inode, hash);
1491 0 : err = ext4_mark_inode_dirty(handle, ea_inode);
1492 0 : if (!err)
1493 0 : err = ext4_inode_attach_jinode(ea_inode);
1494 0 : if (err) {
1495 0 : if (ext4_xattr_inode_dec_ref(handle, ea_inode))
1496 0 : ext4_warning_inode(ea_inode,
1497 : "cleanup dec ref error %d", err);
1498 0 : iput(ea_inode);
1499 0 : return ERR_PTR(err);
1500 : }
1501 :
1502 : /*
1503 : * Xattr inodes are shared therefore quota charging is performed
1504 : * at a higher level.
1505 : */
1506 0 : dquot_free_inode(ea_inode);
1507 0 : dquot_drop(ea_inode);
1508 0 : inode_lock(ea_inode);
1509 0 : ea_inode->i_flags |= S_NOQUOTA;
1510 0 : inode_unlock(ea_inode);
1511 : }
1512 :
1513 : return ea_inode;
1514 : }
1515 :
1516 : static struct inode *
1517 0 : ext4_xattr_inode_cache_find(struct inode *inode, const void *value,
1518 : size_t value_len, u32 hash)
1519 : {
1520 0 : struct inode *ea_inode;
1521 0 : struct mb_cache_entry *ce;
1522 0 : struct mb_cache *ea_inode_cache = EA_INODE_CACHE(inode);
1523 0 : void *ea_data;
1524 :
1525 0 : if (!ea_inode_cache)
1526 : return NULL;
1527 :
1528 0 : ce = mb_cache_entry_find_first(ea_inode_cache, hash);
1529 0 : if (!ce)
1530 : return NULL;
1531 :
1532 0 : WARN_ON_ONCE(ext4_handle_valid(journal_current_handle()) &&
1533 : !(current->flags & PF_MEMALLOC_NOFS));
1534 :
1535 0 : ea_data = kvmalloc(value_len, GFP_KERNEL);
1536 0 : if (!ea_data) {
1537 0 : mb_cache_entry_put(ea_inode_cache, ce);
1538 0 : return NULL;
1539 : }
1540 :
1541 0 : while (ce) {
1542 0 : ea_inode = ext4_iget(inode->i_sb, ce->e_value,
1543 : EXT4_IGET_EA_INODE);
1544 0 : if (IS_ERR(ea_inode))
1545 0 : goto next_entry;
1546 0 : ext4_xattr_inode_set_class(ea_inode);
1547 0 : if (i_size_read(ea_inode) == value_len &&
1548 0 : !ext4_xattr_inode_read(ea_inode, ea_data, value_len) &&
1549 0 : !ext4_xattr_inode_verify_hashes(ea_inode, NULL, ea_data,
1550 0 : value_len) &&
1551 : !memcmp(value, ea_data, value_len)) {
1552 0 : mb_cache_entry_touch(ea_inode_cache, ce);
1553 0 : mb_cache_entry_put(ea_inode_cache, ce);
1554 0 : kvfree(ea_data);
1555 0 : return ea_inode;
1556 : }
1557 0 : iput(ea_inode);
1558 0 : next_entry:
1559 0 : ce = mb_cache_entry_find_next(ea_inode_cache, ce);
1560 : }
1561 0 : kvfree(ea_data);
1562 0 : return NULL;
1563 : }
1564 :
1565 : /*
1566 : * Add value of the EA in an inode.
1567 : */
1568 0 : static 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 0 : struct inode *ea_inode;
1573 0 : u32 hash;
1574 0 : int err;
1575 :
1576 0 : hash = ext4_xattr_inode_hash(EXT4_SB(inode->i_sb), value, value_len);
1577 0 : ea_inode = ext4_xattr_inode_cache_find(inode, value, value_len, hash);
1578 0 : if (ea_inode) {
1579 0 : err = ext4_xattr_inode_inc_ref(handle, ea_inode);
1580 0 : if (err) {
1581 0 : iput(ea_inode);
1582 0 : return err;
1583 : }
1584 :
1585 0 : *ret_inode = ea_inode;
1586 0 : return 0;
1587 : }
1588 :
1589 : /* Create an inode for the EA value */
1590 0 : ea_inode = ext4_xattr_inode_create(handle, inode, hash);
1591 0 : if (IS_ERR(ea_inode))
1592 0 : return PTR_ERR(ea_inode);
1593 :
1594 0 : err = ext4_xattr_inode_write(handle, ea_inode, value, value_len);
1595 0 : if (err) {
1596 0 : if (ext4_xattr_inode_dec_ref(handle, ea_inode))
1597 0 : ext4_warning_inode(ea_inode, "cleanup dec ref error %d", err);
1598 0 : iput(ea_inode);
1599 0 : return err;
1600 : }
1601 :
1602 0 : if (EA_INODE_CACHE(inode))
1603 0 : mb_cache_entry_create(EA_INODE_CACHE(inode), GFP_NOFS, hash,
1604 0 : ea_inode->i_ino, true /* reusable */);
1605 :
1606 0 : *ret_inode = ea_inode;
1607 0 : 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 :
1616 0 : static 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 0 : struct ext4_xattr_entry *last, *next;
1622 0 : struct ext4_xattr_entry *here = s->here;
1623 0 : size_t min_offs = s->end - s->base, name_len = strlen(i->name);
1624 0 : int in_inode = i->in_inode;
1625 0 : struct inode *old_ea_inode = NULL;
1626 0 : struct inode *new_ea_inode = NULL;
1627 0 : size_t old_size, new_size;
1628 0 : int ret;
1629 :
1630 : /* Space used by old and new values. */
1631 0 : old_size = (!s->not_found && !here->e_value_inum) ?
1632 0 : EXT4_XATTR_SIZE(le32_to_cpu(here->e_value_size)) : 0;
1633 0 : 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 0 : if (new_size && new_size == old_size) {
1640 0 : size_t offs = le16_to_cpu(here->e_value_offs);
1641 0 : void *val = s->base + offs;
1642 :
1643 0 : here->e_value_size = cpu_to_le32(i->value_len);
1644 0 : if (i->value == EXT4_ZERO_XATTR_VALUE) {
1645 0 : memset(val, 0, new_size);
1646 : } else {
1647 0 : memcpy(val, i->value, i->value_len);
1648 : /* Clear padding bytes. */
1649 0 : memset(val + i->value_len, 0, new_size - i->value_len);
1650 : }
1651 0 : goto update_hash;
1652 : }
1653 :
1654 : /* Compute min_offs and last. */
1655 0 : last = s->first;
1656 0 : for (; !IS_LAST_ENTRY(last); last = next) {
1657 0 : next = EXT4_XATTR_NEXT(last);
1658 0 : if ((void *)next >= s->end) {
1659 0 : EXT4_ERROR_INODE(inode, "corrupted xattr entries");
1660 0 : ret = -EFSCORRUPTED;
1661 0 : goto out;
1662 : }
1663 0 : if (!last->e_value_inum && last->e_value_size) {
1664 0 : size_t offs = le16_to_cpu(last->e_value_offs);
1665 0 : if (offs < min_offs)
1666 : min_offs = offs;
1667 : }
1668 : }
1669 :
1670 : /* Check whether we have enough space. */
1671 0 : if (i->value) {
1672 0 : size_t free;
1673 :
1674 0 : free = min_offs - ((void *)last - s->base) - sizeof(__u32);
1675 0 : if (!s->not_found)
1676 0 : free += EXT4_XATTR_LEN(name_len) + old_size;
1677 :
1678 0 : if (free < EXT4_XATTR_LEN(name_len) + new_size) {
1679 0 : ret = -ENOSPC;
1680 0 : 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 0 : if (ext4_has_feature_ea_inode(inode->i_sb) &&
1690 0 : new_size && is_block &&
1691 0 : (min_offs + old_size - new_size) <
1692 0 : EXT4_XATTR_BLOCK_RESERVE(inode)) {
1693 0 : ret = -ENOSPC;
1694 0 : 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 0 : if (!s->not_found && here->e_value_inum) {
1703 0 : ret = ext4_xattr_inode_iget(inode,
1704 : le32_to_cpu(here->e_value_inum),
1705 0 : le32_to_cpu(here->e_hash),
1706 : &old_ea_inode);
1707 0 : if (ret) {
1708 0 : old_ea_inode = NULL;
1709 0 : goto out;
1710 : }
1711 : }
1712 0 : if (i->value && in_inode) {
1713 0 : WARN_ON_ONCE(!i->value_len);
1714 :
1715 0 : ret = ext4_xattr_inode_alloc_quota(inode, i->value_len);
1716 0 : if (ret)
1717 0 : goto out;
1718 :
1719 0 : ret = ext4_xattr_inode_lookup_create(handle, inode, i->value,
1720 : i->value_len,
1721 : &new_ea_inode);
1722 0 : if (ret) {
1723 0 : new_ea_inode = NULL;
1724 0 : ext4_xattr_inode_free_quota(inode, NULL, i->value_len);
1725 0 : goto out;
1726 : }
1727 : }
1728 :
1729 0 : if (old_ea_inode) {
1730 : /* We are ready to release ref count on the old_ea_inode. */
1731 0 : ret = ext4_xattr_inode_dec_ref(handle, old_ea_inode);
1732 0 : if (ret) {
1733 : /* Release newly required ref count on new_ea_inode. */
1734 0 : if (new_ea_inode) {
1735 0 : int err;
1736 :
1737 0 : err = ext4_xattr_inode_dec_ref(handle,
1738 : new_ea_inode);
1739 0 : if (err)
1740 0 : ext4_warning_inode(new_ea_inode,
1741 : "dec ref new_ea_inode err=%d",
1742 : err);
1743 0 : ext4_xattr_inode_free_quota(inode, new_ea_inode,
1744 : i->value_len);
1745 : }
1746 0 : goto out;
1747 : }
1748 :
1749 0 : ext4_xattr_inode_free_quota(inode, old_ea_inode,
1750 0 : le32_to_cpu(here->e_value_size));
1751 : }
1752 :
1753 : /* No failures allowed past this point. */
1754 :
1755 0 : if (!s->not_found && here->e_value_size && !here->e_value_inum) {
1756 : /* Remove the old value. */
1757 0 : void *first_val = s->base + min_offs;
1758 0 : size_t offs = le16_to_cpu(here->e_value_offs);
1759 0 : void *val = s->base + offs;
1760 :
1761 0 : memmove(first_val + old_size, first_val, val - first_val);
1762 0 : memset(first_val, 0, old_size);
1763 0 : min_offs += old_size;
1764 :
1765 : /* Adjust all value offsets. */
1766 0 : last = s->first;
1767 0 : while (!IS_LAST_ENTRY(last)) {
1768 0 : size_t o = le16_to_cpu(last->e_value_offs);
1769 :
1770 0 : if (!last->e_value_inum &&
1771 0 : last->e_value_size && o < offs)
1772 0 : last->e_value_offs = cpu_to_le16(o + old_size);
1773 0 : last = EXT4_XATTR_NEXT(last);
1774 : }
1775 : }
1776 :
1777 0 : if (!i->value) {
1778 : /* Remove old name. */
1779 0 : size_t size = EXT4_XATTR_LEN(name_len);
1780 :
1781 0 : last = ENTRY((void *)last - size);
1782 0 : memmove(here, (void *)here + size,
1783 : (void *)last - (void *)here + sizeof(__u32));
1784 0 : 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 0 : if (!is_block && ext4_has_inline_data(inode)) {
1792 0 : ret = ext4_find_inline_data_nolock(inode);
1793 0 : if (ret) {
1794 0 : ext4_warning_inode(inode,
1795 : "unable to update i_inline_off");
1796 0 : goto out;
1797 : }
1798 : }
1799 0 : } else if (s->not_found) {
1800 : /* Insert new name. */
1801 0 : size_t size = EXT4_XATTR_LEN(name_len);
1802 0 : size_t rest = (void *)last - (void *)here + sizeof(__u32);
1803 :
1804 0 : memmove((void *)here + size, here, rest);
1805 0 : memset(here, 0, size);
1806 0 : here->e_name_index = i->name_index;
1807 0 : here->e_name_len = name_len;
1808 0 : memcpy(here->e_name, i->name, name_len);
1809 : } else {
1810 : /* This is an update, reset value info. */
1811 0 : here->e_value_inum = 0;
1812 0 : here->e_value_offs = 0;
1813 0 : here->e_value_size = 0;
1814 : }
1815 :
1816 0 : if (i->value) {
1817 : /* Insert new value. */
1818 0 : if (in_inode) {
1819 0 : here->e_value_inum = cpu_to_le32(new_ea_inode->i_ino);
1820 0 : } else if (i->value_len) {
1821 0 : void *val = s->base + min_offs - new_size;
1822 :
1823 0 : here->e_value_offs = cpu_to_le16(min_offs - new_size);
1824 0 : if (i->value == EXT4_ZERO_XATTR_VALUE) {
1825 0 : memset(val, 0, new_size);
1826 : } else {
1827 0 : memcpy(val, i->value, i->value_len);
1828 : /* Clear padding bytes. */
1829 0 : memset(val + i->value_len, 0,
1830 : new_size - i->value_len);
1831 : }
1832 : }
1833 0 : here->e_value_size = cpu_to_le32(i->value_len);
1834 : }
1835 :
1836 0 : update_hash:
1837 0 : if (i->value) {
1838 0 : __le32 hash = 0;
1839 :
1840 : /* Entry hash calculation. */
1841 0 : if (in_inode) {
1842 0 : __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 0 : crc32c_hash = cpu_to_le32(
1850 : ext4_xattr_inode_get_hash(new_ea_inode));
1851 0 : hash = ext4_xattr_hash_entry(here->e_name,
1852 0 : here->e_name_len,
1853 : &crc32c_hash, 1);
1854 0 : } else if (is_block) {
1855 0 : __le32 *value = s->base + le16_to_cpu(
1856 : here->e_value_offs);
1857 :
1858 0 : hash = ext4_xattr_hash_entry(here->e_name,
1859 0 : here->e_name_len, value,
1860 : new_size >> 2);
1861 : }
1862 0 : here->e_hash = hash;
1863 : }
1864 :
1865 0 : if (is_block)
1866 0 : ext4_xattr_rehash((struct ext4_xattr_header *)s->base);
1867 :
1868 : ret = 0;
1869 0 : out:
1870 0 : iput(old_ea_inode);
1871 0 : iput(new_ea_inode);
1872 0 : return ret;
1873 : }
1874 :
1875 : struct ext4_xattr_block_find {
1876 : struct ext4_xattr_search s;
1877 : struct buffer_head *bh;
1878 : };
1879 :
1880 : static int
1881 0 : ext4_xattr_block_find(struct inode *inode, struct ext4_xattr_info *i,
1882 : struct ext4_xattr_block_find *bs)
1883 : {
1884 0 : struct super_block *sb = inode->i_sb;
1885 0 : int error;
1886 :
1887 0 : 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 0 : if (EXT4_I(inode)->i_file_acl) {
1891 : /* The inode already has an extended attribute block. */
1892 0 : bs->bh = ext4_sb_bread(sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
1893 0 : if (IS_ERR(bs->bh)) {
1894 0 : error = PTR_ERR(bs->bh);
1895 0 : bs->bh = NULL;
1896 0 : return error;
1897 : }
1898 0 : 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 0 : error = ext4_xattr_check_block(inode, bs->bh);
1902 0 : if (error)
1903 : return error;
1904 : /* Find the named attribute. */
1905 0 : bs->s.base = BHDR(bs->bh);
1906 0 : bs->s.first = BFIRST(bs->bh);
1907 0 : bs->s.end = bs->bh->b_data + bs->bh->b_size;
1908 0 : bs->s.here = bs->s.first;
1909 0 : error = xattr_find_entry(inode, &bs->s.here, bs->s.end,
1910 : i->name_index, i->name, 1);
1911 0 : if (error && error != -ENODATA)
1912 : return error;
1913 0 : bs->s.not_found = error;
1914 : }
1915 : return 0;
1916 : }
1917 :
1918 : static int
1919 0 : ext4_xattr_block_set(handle_t *handle, struct inode *inode,
1920 : struct ext4_xattr_info *i,
1921 : struct ext4_xattr_block_find *bs)
1922 : {
1923 0 : struct super_block *sb = inode->i_sb;
1924 0 : struct buffer_head *new_bh = NULL;
1925 0 : struct ext4_xattr_search s_copy = bs->s;
1926 0 : struct ext4_xattr_search *s = &s_copy;
1927 0 : struct mb_cache_entry *ce = NULL;
1928 0 : int error = 0;
1929 0 : struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
1930 0 : struct inode *ea_inode = NULL, *tmp_inode;
1931 0 : size_t old_ea_inode_quota = 0;
1932 0 : unsigned int ea_ino;
1933 :
1934 :
1935 : #define header(x) ((struct ext4_xattr_header *)(x))
1936 :
1937 0 : if (s->base) {
1938 0 : int offset = (char *)s->here - bs->bh->b_data;
1939 :
1940 0 : BUFFER_TRACE(bs->bh, "get_write_access");
1941 0 : error = ext4_journal_get_write_access(handle, sb, bs->bh,
1942 : EXT4_JTR_NONE);
1943 0 : if (error)
1944 0 : goto cleanup;
1945 0 : lock_buffer(bs->bh);
1946 :
1947 0 : if (header(s->base)->h_refcount == cpu_to_le32(1)) {
1948 0 : __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 0 : if (ea_block_cache) {
1956 0 : struct mb_cache_entry *oe;
1957 :
1958 0 : oe = mb_cache_entry_delete_or_get(ea_block_cache,
1959 : hash, bs->bh->b_blocknr);
1960 0 : if (oe) {
1961 : /*
1962 : * Xattr block is getting reused. Leave
1963 : * it alone.
1964 : */
1965 0 : mb_cache_entry_put(ea_block_cache, oe);
1966 0 : goto clone_block;
1967 : }
1968 : }
1969 0 : ea_bdebug(bs->bh, "modifying in-place");
1970 0 : error = ext4_xattr_set_entry(i, s, handle, inode,
1971 : true /* is_block */);
1972 0 : ext4_xattr_block_csum_set(inode, bs->bh);
1973 0 : unlock_buffer(bs->bh);
1974 0 : if (error == -EFSCORRUPTED)
1975 0 : goto bad_block;
1976 0 : if (!error)
1977 0 : error = ext4_handle_dirty_metadata(handle,
1978 : inode,
1979 : bs->bh);
1980 0 : if (error)
1981 0 : goto cleanup;
1982 0 : goto inserted;
1983 : }
1984 0 : clone_block:
1985 0 : unlock_buffer(bs->bh);
1986 0 : ea_bdebug(bs->bh, "cloning");
1987 0 : s->base = kmemdup(BHDR(bs->bh), bs->bh->b_size, GFP_NOFS);
1988 0 : error = -ENOMEM;
1989 0 : if (s->base == NULL)
1990 0 : goto cleanup;
1991 0 : s->first = ENTRY(header(s->base)+1);
1992 0 : header(s->base)->h_refcount = cpu_to_le32(1);
1993 0 : s->here = ENTRY(s->base + offset);
1994 0 : 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 0 : if (!s->not_found && s->here->e_value_inum) {
2004 0 : ea_ino = le32_to_cpu(s->here->e_value_inum);
2005 0 : error = ext4_xattr_inode_iget(inode, ea_ino,
2006 0 : le32_to_cpu(s->here->e_hash),
2007 : &tmp_inode);
2008 0 : if (error)
2009 0 : goto cleanup;
2010 :
2011 0 : 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 0 : old_ea_inode_quota = le32_to_cpu(
2018 : s->here->e_value_size);
2019 : }
2020 0 : iput(tmp_inode);
2021 :
2022 0 : s->here->e_value_inum = 0;
2023 0 : s->here->e_value_size = 0;
2024 : }
2025 : } else {
2026 : /* Allocate a buffer where we construct the new block. */
2027 0 : s->base = kzalloc(sb->s_blocksize, GFP_NOFS);
2028 0 : error = -ENOMEM;
2029 0 : if (s->base == NULL)
2030 0 : goto cleanup;
2031 0 : header(s->base)->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
2032 0 : header(s->base)->h_blocks = cpu_to_le32(1);
2033 0 : header(s->base)->h_refcount = cpu_to_le32(1);
2034 0 : s->first = ENTRY(header(s->base)+1);
2035 0 : s->here = ENTRY(header(s->base)+1);
2036 0 : s->end = s->base + sb->s_blocksize;
2037 : }
2038 :
2039 0 : error = ext4_xattr_set_entry(i, s, handle, inode, true /* is_block */);
2040 0 : if (error == -EFSCORRUPTED)
2041 0 : goto bad_block;
2042 0 : if (error)
2043 0 : goto cleanup;
2044 :
2045 0 : 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 0 : ea_ino = le32_to_cpu(s->here->e_value_inum);
2053 0 : error = ext4_xattr_inode_iget(inode, ea_ino,
2054 0 : le32_to_cpu(s->here->e_hash),
2055 : &ea_inode);
2056 0 : if (error) {
2057 0 : ea_inode = NULL;
2058 0 : goto cleanup;
2059 : }
2060 : }
2061 :
2062 0 : inserted:
2063 0 : if (!IS_LAST_ENTRY(s->first)) {
2064 0 : new_bh = ext4_xattr_block_cache_find(inode, header(s->base),
2065 : &ce);
2066 0 : if (new_bh) {
2067 : /* We found an identical block in the cache. */
2068 0 : if (new_bh == bs->bh)
2069 : ea_bdebug(new_bh, "keeping");
2070 : else {
2071 0 : 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 0 : error = dquot_alloc_block(inode,
2079 0 : EXT4_C2B(EXT4_SB(sb), 1));
2080 0 : if (error)
2081 0 : goto cleanup;
2082 0 : BUFFER_TRACE(new_bh, "get_write_access");
2083 0 : error = ext4_journal_get_write_access(
2084 : handle, sb, new_bh,
2085 : EXT4_JTR_NONE);
2086 0 : if (error)
2087 0 : goto cleanup_dquot;
2088 0 : 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 0 : ref = le32_to_cpu(BHDR(new_bh)->h_refcount) + 1;
2097 0 : if (ref > EXT4_XATTR_REFCOUNT_MAX) {
2098 : /*
2099 : * Undo everything and check mbcache
2100 : * again.
2101 : */
2102 0 : unlock_buffer(new_bh);
2103 0 : dquot_free_block(inode,
2104 0 : EXT4_C2B(EXT4_SB(sb),
2105 : 1));
2106 0 : brelse(new_bh);
2107 0 : mb_cache_entry_put(ea_block_cache, ce);
2108 0 : ce = NULL;
2109 0 : new_bh = NULL;
2110 0 : goto inserted;
2111 : }
2112 0 : BHDR(new_bh)->h_refcount = cpu_to_le32(ref);
2113 0 : if (ref == EXT4_XATTR_REFCOUNT_MAX)
2114 0 : clear_bit(MBE_REUSABLE_B, &ce->e_flags);
2115 0 : ea_bdebug(new_bh, "reusing; refcount now=%d",
2116 : ref);
2117 0 : ext4_xattr_block_csum_set(inode, new_bh);
2118 0 : unlock_buffer(new_bh);
2119 0 : error = ext4_handle_dirty_metadata(handle,
2120 : inode,
2121 : new_bh);
2122 0 : if (error)
2123 0 : goto cleanup_dquot;
2124 : }
2125 0 : mb_cache_entry_touch(ea_block_cache, ce);
2126 0 : mb_cache_entry_put(ea_block_cache, ce);
2127 0 : ce = NULL;
2128 0 : } else if (bs->bh && s->base == bs->bh->b_data) {
2129 : /* We were modifying this block in-place. */
2130 0 : ea_bdebug(bs->bh, "keeping this block");
2131 0 : ext4_xattr_block_cache_insert(ea_block_cache, bs->bh);
2132 0 : new_bh = bs->bh;
2133 0 : get_bh(new_bh);
2134 : } else {
2135 : /* We need to allocate a new block */
2136 0 : ext4_fsblk_t goal, block;
2137 :
2138 : #ifdef EXT4_XATTR_DEBUG
2139 : WARN_ON_ONCE(dquot_initialize_needed(inode));
2140 : #endif
2141 0 : goal = ext4_group_first_block_no(sb,
2142 : EXT4_I(inode)->i_block_group);
2143 0 : block = ext4_new_meta_blocks(handle, inode, goal, 0,
2144 : NULL, &error);
2145 0 : if (error)
2146 0 : goto cleanup;
2147 :
2148 0 : ea_idebug(inode, "creating block %llu",
2149 : (unsigned long long)block);
2150 :
2151 0 : new_bh = sb_getblk(sb, block);
2152 0 : if (unlikely(!new_bh)) {
2153 0 : error = -ENOMEM;
2154 0 : getblk_failed:
2155 0 : ext4_free_blocks(handle, inode, NULL, block, 1,
2156 : EXT4_FREE_BLOCKS_METADATA);
2157 0 : goto cleanup;
2158 : }
2159 0 : error = ext4_xattr_inode_inc_ref_all(handle, inode,
2160 0 : ENTRY(header(s->base)+1));
2161 0 : if (error)
2162 0 : goto getblk_failed;
2163 0 : if (ea_inode) {
2164 : /* Drop the extra ref on ea_inode. */
2165 0 : error = ext4_xattr_inode_dec_ref(handle,
2166 : ea_inode);
2167 0 : if (error)
2168 0 : ext4_warning_inode(ea_inode,
2169 : "dec ref error=%d",
2170 : error);
2171 0 : iput(ea_inode);
2172 0 : ea_inode = NULL;
2173 : }
2174 :
2175 0 : lock_buffer(new_bh);
2176 0 : error = ext4_journal_get_create_access(handle, sb,
2177 : new_bh, EXT4_JTR_NONE);
2178 0 : if (error) {
2179 0 : unlock_buffer(new_bh);
2180 0 : error = -EIO;
2181 0 : goto getblk_failed;
2182 : }
2183 0 : memcpy(new_bh->b_data, s->base, new_bh->b_size);
2184 0 : ext4_xattr_block_csum_set(inode, new_bh);
2185 0 : set_buffer_uptodate(new_bh);
2186 0 : unlock_buffer(new_bh);
2187 0 : ext4_xattr_block_cache_insert(ea_block_cache, new_bh);
2188 0 : error = ext4_handle_dirty_metadata(handle, inode,
2189 : new_bh);
2190 0 : if (error)
2191 0 : goto cleanup;
2192 : }
2193 : }
2194 :
2195 0 : if (old_ea_inode_quota)
2196 0 : ext4_xattr_inode_free_quota(inode, NULL, old_ea_inode_quota);
2197 :
2198 : /* Update the inode. */
2199 0 : EXT4_I(inode)->i_file_acl = new_bh ? new_bh->b_blocknr : 0;
2200 :
2201 : /* Drop the previous xattr block. */
2202 0 : if (bs->bh && bs->bh != new_bh) {
2203 0 : struct ext4_xattr_inode_array *ea_inode_array = NULL;
2204 :
2205 0 : ext4_xattr_release_block(handle, inode, bs->bh,
2206 : &ea_inode_array,
2207 : 0 /* extra_credits */);
2208 0 : ext4_xattr_inode_array_free(ea_inode_array);
2209 : }
2210 0 : error = 0;
2211 :
2212 0 : cleanup:
2213 0 : if (ea_inode) {
2214 0 : int error2;
2215 :
2216 0 : error2 = ext4_xattr_inode_dec_ref(handle, ea_inode);
2217 0 : if (error2)
2218 0 : ext4_warning_inode(ea_inode, "dec ref error=%d",
2219 : error2);
2220 :
2221 : /* If there was an error, revert the quota charge. */
2222 0 : if (error)
2223 0 : ext4_xattr_inode_free_quota(inode, ea_inode,
2224 : i_size_read(ea_inode));
2225 0 : iput(ea_inode);
2226 : }
2227 0 : if (ce)
2228 0 : mb_cache_entry_put(ea_block_cache, ce);
2229 0 : brelse(new_bh);
2230 0 : if (!(bs->bh && s->base == bs->bh->b_data))
2231 0 : kfree(s->base);
2232 :
2233 0 : return error;
2234 :
2235 0 : cleanup_dquot:
2236 0 : dquot_free_block(inode, EXT4_C2B(EXT4_SB(sb), 1));
2237 0 : goto cleanup;
2238 :
2239 0 : bad_block:
2240 0 : EXT4_ERROR_INODE(inode, "bad block %llu",
2241 : EXT4_I(inode)->i_file_acl);
2242 0 : goto cleanup;
2243 :
2244 : #undef header
2245 : }
2246 :
2247 0 : int ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i,
2248 : struct ext4_xattr_ibody_find *is)
2249 : {
2250 0 : struct ext4_xattr_ibody_header *header;
2251 0 : struct ext4_inode *raw_inode;
2252 0 : int error;
2253 :
2254 0 : if (!EXT4_INODE_HAS_XATTR_SPACE(inode))
2255 : return 0;
2256 :
2257 0 : raw_inode = ext4_raw_inode(&is->iloc);
2258 0 : header = IHDR(inode, raw_inode);
2259 0 : is->s.base = is->s.first = IFIRST(header);
2260 0 : is->s.here = is->s.first;
2261 0 : is->s.end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
2262 0 : if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
2263 0 : error = xattr_check_inode(inode, header, is->s.end);
2264 0 : if (error)
2265 : return error;
2266 : /* Find the named attribute. */
2267 0 : error = xattr_find_entry(inode, &is->s.here, is->s.end,
2268 : i->name_index, i->name, 0);
2269 0 : if (error && error != -ENODATA)
2270 : return error;
2271 0 : is->s.not_found = error;
2272 : }
2273 : return 0;
2274 : }
2275 :
2276 0 : int 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 0 : struct ext4_xattr_ibody_header *header;
2281 0 : struct ext4_xattr_search *s = &is->s;
2282 0 : int error;
2283 :
2284 0 : if (!EXT4_INODE_HAS_XATTR_SPACE(inode))
2285 : return -ENOSPC;
2286 :
2287 0 : error = ext4_xattr_set_entry(i, s, handle, inode, false /* is_block */);
2288 0 : if (error)
2289 : return error;
2290 0 : header = IHDR(inode, ext4_raw_inode(&is->iloc));
2291 0 : if (!IS_LAST_ENTRY(s->first)) {
2292 0 : header->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
2293 0 : ext4_set_inode_state(inode, EXT4_STATE_XATTR);
2294 : } else {
2295 0 : header->h_magic = cpu_to_le32(0);
2296 0 : ext4_clear_inode_state(inode, EXT4_STATE_XATTR);
2297 : }
2298 : return 0;
2299 : }
2300 :
2301 0 : static int ext4_xattr_value_same(struct ext4_xattr_search *s,
2302 : struct ext4_xattr_info *i)
2303 : {
2304 0 : void *value;
2305 :
2306 : /* When e_value_inum is set the value is stored externally. */
2307 0 : if (s->here->e_value_inum)
2308 : return 0;
2309 0 : if (le32_to_cpu(s->here->e_value_size) != i->value_len)
2310 : return 0;
2311 0 : value = ((void *)s->base) + le16_to_cpu(s->here->e_value_offs);
2312 0 : return !memcmp(value, i->value, i->value_len);
2313 : }
2314 :
2315 0 : static struct buffer_head *ext4_xattr_get_block(struct inode *inode)
2316 : {
2317 0 : struct buffer_head *bh;
2318 0 : int error;
2319 :
2320 0 : if (!EXT4_I(inode)->i_file_acl)
2321 : return NULL;
2322 0 : bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
2323 0 : if (IS_ERR(bh))
2324 : return bh;
2325 0 : error = ext4_xattr_check_block(inode, bh);
2326 0 : if (error) {
2327 0 : brelse(bh);
2328 0 : 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 : */
2345 : int
2346 0 : ext4_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 0 : 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 0 : struct ext4_xattr_ibody_find is = {
2358 : .s = { .not_found = -ENODATA, },
2359 : };
2360 0 : struct ext4_xattr_block_find bs = {
2361 : .s = { .not_found = -ENODATA, },
2362 : };
2363 0 : int no_expand;
2364 0 : int error;
2365 :
2366 0 : if (!name)
2367 : return -EINVAL;
2368 0 : if (strlen(name) > 255)
2369 : return -ERANGE;
2370 :
2371 0 : ext4_write_lock_xattr(inode, &no_expand);
2372 :
2373 : /* Check journal credits under write lock. */
2374 0 : if (ext4_handle_valid(handle)) {
2375 0 : struct buffer_head *bh;
2376 0 : int credits;
2377 :
2378 0 : bh = ext4_xattr_get_block(inode);
2379 0 : if (IS_ERR(bh)) {
2380 0 : error = PTR_ERR(bh);
2381 0 : goto cleanup;
2382 : }
2383 :
2384 0 : credits = __ext4_xattr_set_credits(inode->i_sb, inode, bh,
2385 : value_len,
2386 : flags & XATTR_CREATE);
2387 0 : brelse(bh);
2388 :
2389 0 : if (jbd2_handle_buffer_credits(handle) < credits) {
2390 0 : error = -ENOSPC;
2391 0 : goto cleanup;
2392 : }
2393 0 : WARN_ON_ONCE(!(current->flags & PF_MEMALLOC_NOFS));
2394 : }
2395 :
2396 0 : error = ext4_reserve_inode_write(handle, inode, &is.iloc);
2397 0 : if (error)
2398 0 : goto cleanup;
2399 :
2400 0 : if (ext4_test_inode_state(inode, EXT4_STATE_NEW)) {
2401 0 : struct ext4_inode *raw_inode = ext4_raw_inode(&is.iloc);
2402 0 : memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size);
2403 0 : ext4_clear_inode_state(inode, EXT4_STATE_NEW);
2404 : }
2405 :
2406 0 : error = ext4_xattr_ibody_find(inode, &i, &is);
2407 0 : if (error)
2408 0 : goto cleanup;
2409 0 : if (is.s.not_found)
2410 0 : error = ext4_xattr_block_find(inode, &i, &bs);
2411 0 : if (error)
2412 0 : goto cleanup;
2413 0 : if (is.s.not_found && bs.s.not_found) {
2414 0 : error = -ENODATA;
2415 0 : if (flags & XATTR_REPLACE)
2416 0 : goto cleanup;
2417 0 : error = 0;
2418 0 : if (!value)
2419 0 : goto cleanup;
2420 : } else {
2421 0 : error = -EEXIST;
2422 0 : if (flags & XATTR_CREATE)
2423 0 : goto cleanup;
2424 : }
2425 :
2426 0 : if (!value) {
2427 0 : if (!is.s.not_found)
2428 0 : error = ext4_xattr_ibody_set(handle, inode, &i, &is);
2429 0 : else if (!bs.s.not_found)
2430 0 : error = ext4_xattr_block_set(handle, inode, &i, &bs);
2431 : } else {
2432 0 : error = 0;
2433 : /* Xattr value did not change? Save us some work and bail out */
2434 0 : if (!is.s.not_found && ext4_xattr_value_same(&is.s, &i))
2435 0 : goto cleanup;
2436 0 : if (!bs.s.not_found && ext4_xattr_value_same(&bs.s, &i))
2437 0 : goto cleanup;
2438 :
2439 0 : if (ext4_has_feature_ea_inode(inode->i_sb) &&
2440 0 : (EXT4_XATTR_SIZE(i.value_len) >
2441 0 : EXT4_XATTR_MIN_LARGE_EA_SIZE(inode->i_sb->s_blocksize)))
2442 0 : i.in_inode = 1;
2443 0 : retry_inode:
2444 0 : error = ext4_xattr_ibody_set(handle, inode, &i, &is);
2445 0 : if (!error && !bs.s.not_found) {
2446 0 : i.value = NULL;
2447 0 : error = ext4_xattr_block_set(handle, inode, &i, &bs);
2448 0 : } else if (error == -ENOSPC) {
2449 0 : if (EXT4_I(inode)->i_file_acl && !bs.s.base) {
2450 0 : brelse(bs.bh);
2451 0 : bs.bh = NULL;
2452 0 : error = ext4_xattr_block_find(inode, &i, &bs);
2453 0 : if (error)
2454 0 : goto cleanup;
2455 : }
2456 0 : error = ext4_xattr_block_set(handle, inode, &i, &bs);
2457 0 : if (!error && !is.s.not_found) {
2458 0 : i.value = NULL;
2459 0 : error = ext4_xattr_ibody_set(handle, inode, &i,
2460 : &is);
2461 0 : } else if (error == -ENOSPC) {
2462 : /*
2463 : * Xattr does not fit in the block, store at
2464 : * external inode if possible.
2465 : */
2466 0 : if (ext4_has_feature_ea_inode(inode->i_sb) &&
2467 0 : i.value_len && !i.in_inode) {
2468 0 : i.in_inode = 1;
2469 0 : goto retry_inode;
2470 : }
2471 : }
2472 : }
2473 : }
2474 0 : if (!error) {
2475 0 : ext4_xattr_update_super_block(handle, inode->i_sb);
2476 0 : inode->i_ctime = current_time(inode);
2477 0 : inode_inc_iversion(inode);
2478 0 : if (!value)
2479 0 : no_expand = 0;
2480 0 : 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 0 : is.iloc.bh = NULL;
2486 0 : if (IS_SYNC(inode))
2487 0 : ext4_handle_sync(handle);
2488 : }
2489 0 : ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_XATTR, handle);
2490 :
2491 0 : cleanup:
2492 0 : brelse(is.iloc.bh);
2493 0 : brelse(bs.bh);
2494 0 : ext4_write_unlock_xattr(inode, &no_expand);
2495 0 : return error;
2496 : }
2497 :
2498 0 : int ext4_xattr_set_credits(struct inode *inode, size_t value_len,
2499 : bool is_create, int *credits)
2500 : {
2501 0 : struct buffer_head *bh;
2502 0 : int err;
2503 :
2504 0 : *credits = 0;
2505 :
2506 0 : if (!EXT4_SB(inode->i_sb)->s_journal)
2507 : return 0;
2508 :
2509 0 : down_read(&EXT4_I(inode)->xattr_sem);
2510 :
2511 0 : bh = ext4_xattr_get_block(inode);
2512 0 : if (IS_ERR(bh)) {
2513 0 : err = PTR_ERR(bh);
2514 : } else {
2515 0 : *credits = __ext4_xattr_set_credits(inode->i_sb, inode, bh,
2516 : value_len, is_create);
2517 0 : brelse(bh);
2518 : err = 0;
2519 : }
2520 :
2521 0 : up_read(&EXT4_I(inode)->xattr_sem);
2522 0 : 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 : */
2533 : int
2534 0 : ext4_xattr_set(struct inode *inode, int name_index, const char *name,
2535 : const void *value, size_t value_len, int flags)
2536 : {
2537 0 : handle_t *handle;
2538 0 : struct super_block *sb = inode->i_sb;
2539 0 : int error, retries = 0;
2540 0 : int credits;
2541 :
2542 0 : error = dquot_initialize(inode);
2543 0 : if (error)
2544 : return error;
2545 :
2546 0 : retry:
2547 0 : error = ext4_xattr_set_credits(inode, value_len, flags & XATTR_CREATE,
2548 : &credits);
2549 0 : if (error)
2550 0 : return error;
2551 :
2552 0 : handle = ext4_journal_start(inode, EXT4_HT_XATTR, credits);
2553 0 : if (IS_ERR(handle)) {
2554 0 : error = PTR_ERR(handle);
2555 : } else {
2556 0 : int error2;
2557 :
2558 0 : error = ext4_xattr_set_handle(handle, inode, name_index, name,
2559 : value, value_len, flags);
2560 0 : error2 = ext4_journal_stop(handle);
2561 0 : if (error == -ENOSPC &&
2562 0 : ext4_should_retry_alloc(sb, &retries))
2563 0 : goto retry;
2564 0 : if (error == 0)
2565 0 : error = error2;
2566 : }
2567 0 : ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_XATTR, NULL);
2568 :
2569 0 : return error;
2570 : }
2571 :
2572 : /*
2573 : * Shift the EA entries in the inode to create space for the increased
2574 : * i_extra_isize.
2575 : */
2576 0 : static 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 0 : struct ext4_xattr_entry *last = entry;
2581 0 : int new_offs;
2582 :
2583 : /* We always shift xattr headers further thus offsets get lower */
2584 0 : BUG_ON(value_offs_shift > 0);
2585 :
2586 : /* Adjust the value offsets of the entries */
2587 0 : for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
2588 0 : if (!last->e_value_inum && last->e_value_size) {
2589 0 : new_offs = le16_to_cpu(last->e_value_offs) +
2590 : value_offs_shift;
2591 0 : last->e_value_offs = cpu_to_le16(new_offs);
2592 : }
2593 : }
2594 : /* Shift the entries by n bytes */
2595 0 : memmove(to, from, n);
2596 0 : }
2597 :
2598 : /*
2599 : * Move xattr pointed to by 'entry' from inode into external xattr block
2600 : */
2601 0 : static 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 0 : struct ext4_xattr_ibody_find *is = NULL;
2606 0 : struct ext4_xattr_block_find *bs = NULL;
2607 0 : char *buffer = NULL, *b_entry_name = NULL;
2608 0 : size_t value_size = le32_to_cpu(entry->e_value_size);
2609 0 : struct ext4_xattr_info i = {
2610 : .value = NULL,
2611 : .value_len = 0,
2612 0 : .name_index = entry->e_name_index,
2613 0 : .in_inode = !!entry->e_value_inum,
2614 : };
2615 0 : struct ext4_xattr_ibody_header *header = IHDR(inode, raw_inode);
2616 0 : int needs_kvfree = 0;
2617 0 : int error;
2618 :
2619 0 : is = kzalloc(sizeof(struct ext4_xattr_ibody_find), GFP_NOFS);
2620 0 : bs = kzalloc(sizeof(struct ext4_xattr_block_find), GFP_NOFS);
2621 0 : b_entry_name = kmalloc(entry->e_name_len + 1, GFP_NOFS);
2622 0 : if (!is || !bs || !b_entry_name) {
2623 0 : error = -ENOMEM;
2624 0 : goto out;
2625 : }
2626 :
2627 0 : is->s.not_found = -ENODATA;
2628 0 : bs->s.not_found = -ENODATA;
2629 0 : is->iloc.bh = NULL;
2630 0 : bs->bh = NULL;
2631 :
2632 : /* Save the entry name and the entry value */
2633 0 : if (entry->e_value_inum) {
2634 0 : buffer = kvmalloc(value_size, GFP_NOFS);
2635 0 : if (!buffer) {
2636 0 : error = -ENOMEM;
2637 0 : goto out;
2638 : }
2639 0 : needs_kvfree = 1;
2640 0 : error = ext4_xattr_inode_get(inode, entry, buffer, value_size);
2641 0 : if (error)
2642 0 : goto out;
2643 : } else {
2644 0 : size_t value_offs = le16_to_cpu(entry->e_value_offs);
2645 0 : buffer = (void *)IFIRST(header) + value_offs;
2646 : }
2647 :
2648 0 : memcpy(b_entry_name, entry->e_name, entry->e_name_len);
2649 0 : b_entry_name[entry->e_name_len] = '\0';
2650 0 : i.name = b_entry_name;
2651 :
2652 0 : error = ext4_get_inode_loc(inode, &is->iloc);
2653 0 : if (error)
2654 0 : goto out;
2655 :
2656 0 : error = ext4_xattr_ibody_find(inode, &i, is);
2657 0 : if (error)
2658 0 : goto out;
2659 :
2660 0 : i.value = buffer;
2661 0 : i.value_len = value_size;
2662 0 : error = ext4_xattr_block_find(inode, &i, bs);
2663 0 : if (error)
2664 0 : goto out;
2665 :
2666 : /* Move ea entry from the inode into the block */
2667 0 : error = ext4_xattr_block_set(handle, inode, &i, bs);
2668 0 : if (error)
2669 0 : goto out;
2670 :
2671 : /* Remove the chosen entry from the inode */
2672 0 : i.value = NULL;
2673 0 : i.value_len = 0;
2674 0 : error = ext4_xattr_ibody_set(handle, inode, &i, is);
2675 :
2676 0 : out:
2677 0 : kfree(b_entry_name);
2678 0 : if (needs_kvfree && buffer)
2679 0 : kvfree(buffer);
2680 0 : if (is)
2681 0 : brelse(is->iloc.bh);
2682 0 : if (bs)
2683 0 : brelse(bs->bh);
2684 0 : kfree(is);
2685 0 : kfree(bs);
2686 :
2687 0 : return error;
2688 : }
2689 :
2690 0 : static 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 0 : struct ext4_xattr_ibody_header *header = IHDR(inode, raw_inode);
2696 0 : struct ext4_xattr_entry *small_entry;
2697 0 : struct ext4_xattr_entry *entry;
2698 0 : struct ext4_xattr_entry *last;
2699 0 : unsigned int entry_size; /* EA entry size */
2700 0 : unsigned int total_size; /* EA entry size + value size */
2701 0 : unsigned int min_total_size;
2702 0 : int error;
2703 :
2704 0 : while (isize_diff > ifree) {
2705 0 : entry = NULL;
2706 0 : small_entry = NULL;
2707 0 : min_total_size = ~0U;
2708 0 : last = IFIRST(header);
2709 : /* Find the entry best suited to be pushed into EA block */
2710 0 : for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
2711 : /* never move system.data out of the inode */
2712 0 : if ((last->e_name_len == 4) &&
2713 0 : (last->e_name_index == EXT4_XATTR_INDEX_SYSTEM) &&
2714 0 : !memcmp(last->e_name, "data", 4))
2715 0 : continue;
2716 0 : total_size = EXT4_XATTR_LEN(last->e_name_len);
2717 0 : if (!last->e_value_inum)
2718 0 : total_size += EXT4_XATTR_SIZE(
2719 : le32_to_cpu(last->e_value_size));
2720 0 : if (total_size <= bfree &&
2721 : total_size < min_total_size) {
2722 0 : if (total_size + ifree < isize_diff) {
2723 : small_entry = last;
2724 : } else {
2725 0 : entry = last;
2726 0 : min_total_size = total_size;
2727 : }
2728 : }
2729 : }
2730 :
2731 0 : if (entry == NULL) {
2732 0 : if (small_entry == NULL)
2733 : return -ENOSPC;
2734 : entry = small_entry;
2735 : }
2736 :
2737 0 : entry_size = EXT4_XATTR_LEN(entry->e_name_len);
2738 0 : total_size = entry_size;
2739 0 : if (!entry->e_value_inum)
2740 0 : total_size += EXT4_XATTR_SIZE(
2741 : le32_to_cpu(entry->e_value_size));
2742 0 : error = ext4_xattr_move_to_block(handle, inode, raw_inode,
2743 : entry);
2744 0 : if (error)
2745 0 : return error;
2746 :
2747 0 : *total_ino -= entry_size;
2748 0 : ifree += total_size;
2749 0 : 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 : */
2759 0 : int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
2760 : struct ext4_inode *raw_inode, handle_t *handle)
2761 : {
2762 0 : struct ext4_xattr_ibody_header *header;
2763 0 : struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2764 0 : static unsigned int mnt_count;
2765 0 : size_t min_offs;
2766 0 : size_t ifree, bfree;
2767 0 : int total_ino;
2768 0 : void *base, *end;
2769 0 : int error = 0, tried_min_extra_isize = 0;
2770 0 : int s_min_extra_isize = le16_to_cpu(sbi->s_es->s_min_extra_isize);
2771 0 : int isize_diff; /* How much do we need to grow i_extra_isize */
2772 :
2773 : retry:
2774 0 : isize_diff = new_extra_isize - EXT4_I(inode)->i_extra_isize;
2775 0 : if (EXT4_I(inode)->i_extra_isize >= new_extra_isize)
2776 : return 0;
2777 :
2778 0 : 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 0 : base = IFIRST(header);
2786 0 : end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
2787 0 : min_offs = end - base;
2788 0 : total_ino = sizeof(struct ext4_xattr_ibody_header) + sizeof(u32);
2789 :
2790 0 : error = xattr_check_inode(inode, header, end);
2791 0 : if (error)
2792 0 : goto cleanup;
2793 :
2794 0 : ifree = ext4_xattr_free_space(base, &min_offs, base, &total_ino);
2795 0 : if (ifree >= isize_diff)
2796 0 : 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 0 : if (EXT4_I(inode)->i_file_acl) {
2803 0 : struct buffer_head *bh;
2804 :
2805 0 : bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
2806 0 : if (IS_ERR(bh)) {
2807 0 : error = PTR_ERR(bh);
2808 0 : goto cleanup;
2809 : }
2810 0 : error = ext4_xattr_check_block(inode, bh);
2811 0 : if (error) {
2812 0 : brelse(bh);
2813 0 : goto cleanup;
2814 : }
2815 0 : base = BHDR(bh);
2816 0 : end = bh->b_data + bh->b_size;
2817 0 : min_offs = end - base;
2818 0 : bfree = ext4_xattr_free_space(BFIRST(bh), &min_offs, base,
2819 : NULL);
2820 0 : brelse(bh);
2821 0 : if (bfree + ifree < isize_diff) {
2822 0 : if (!tried_min_extra_isize && s_min_extra_isize) {
2823 0 : tried_min_extra_isize++;
2824 0 : new_extra_isize = s_min_extra_isize;
2825 0 : goto retry;
2826 : }
2827 0 : error = -ENOSPC;
2828 0 : goto cleanup;
2829 : }
2830 : } else {
2831 0 : bfree = inode->i_sb->s_blocksize;
2832 : }
2833 :
2834 0 : error = ext4_xattr_make_inode_space(handle, inode, raw_inode,
2835 : isize_diff, ifree, bfree,
2836 : &total_ino);
2837 0 : if (error) {
2838 0 : if (error == -ENOSPC && !tried_min_extra_isize &&
2839 : s_min_extra_isize) {
2840 0 : tried_min_extra_isize++;
2841 0 : new_extra_isize = s_min_extra_isize;
2842 0 : goto retry;
2843 : }
2844 0 : goto cleanup;
2845 : }
2846 0 : shift:
2847 : /* Adjust the offsets and shift the remaining entries ahead */
2848 0 : ext4_xattr_shift_entries(IFIRST(header), EXT4_I(inode)->i_extra_isize
2849 : - new_extra_isize, (void *)raw_inode +
2850 0 : EXT4_GOOD_OLD_INODE_SIZE + new_extra_isize,
2851 : (void *)header, total_ino);
2852 0 : EXT4_I(inode)->i_extra_isize = new_extra_isize;
2853 :
2854 0 : if (ext4_has_inline_data(inode))
2855 0 : error = ext4_find_inline_data_nolock(inode);
2856 :
2857 0 : cleanup:
2858 0 : if (error && (mnt_count != le16_to_cpu(sbi->s_es->s_mnt_count))) {
2859 0 : ext4_warning(inode->i_sb, "Unable to expand inode %lu. Delete some EAs or run e2fsck.",
2860 : inode->i_ino);
2861 0 : 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 : */
2873 : static int
2874 0 : ext4_expand_inode_array(struct ext4_xattr_inode_array **ea_inode_array,
2875 : struct inode *inode)
2876 : {
2877 0 : 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 0 : (*ea_inode_array) =
2883 : kmalloc(offsetof(struct ext4_xattr_inode_array,
2884 : inodes[EIA_MASK]),
2885 : GFP_NOFS);
2886 0 : if (*ea_inode_array == NULL)
2887 : return -ENOMEM;
2888 0 : (*ea_inode_array)->count = 0;
2889 0 : } else if (((*ea_inode_array)->count & EIA_MASK) == EIA_MASK) {
2890 : /* expand the array once all 15 + n * 16 slots are full */
2891 0 : struct ext4_xattr_inode_array *new_array = NULL;
2892 0 : int count = (*ea_inode_array)->count;
2893 :
2894 : /* if new_array is NULL, this is essentially offsetof() */
2895 0 : new_array = kmalloc(
2896 0 : offsetof(struct ext4_xattr_inode_array,
2897 : inodes[count + EIA_INCR]),
2898 : GFP_NOFS);
2899 0 : if (new_array == NULL)
2900 : return -ENOMEM;
2901 0 : memcpy(new_array, *ea_inode_array,
2902 : offsetof(struct ext4_xattr_inode_array, inodes[count]));
2903 0 : kfree(*ea_inode_array);
2904 0 : *ea_inode_array = new_array;
2905 : }
2906 0 : (*ea_inode_array)->inodes[(*ea_inode_array)->count++] = inode;
2907 0 : 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 : */
2919 0 : int 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 0 : struct buffer_head *bh = NULL;
2924 0 : struct ext4_xattr_ibody_header *header;
2925 0 : struct ext4_iloc iloc = { .bh = NULL };
2926 0 : struct ext4_xattr_entry *entry;
2927 0 : struct inode *ea_inode;
2928 0 : int error;
2929 :
2930 0 : error = ext4_journal_ensure_credits(handle, extra_credits,
2931 : ext4_free_metadata_revoke_credits(inode->i_sb, 1));
2932 0 : if (error < 0) {
2933 0 : EXT4_ERROR_INODE(inode, "ensure credits (error %d)", error);
2934 0 : goto cleanup;
2935 : }
2936 :
2937 0 : if (ext4_has_feature_ea_inode(inode->i_sb) &&
2938 : ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
2939 :
2940 0 : error = ext4_get_inode_loc(inode, &iloc);
2941 0 : if (error) {
2942 0 : EXT4_ERROR_INODE(inode, "inode loc (error %d)", error);
2943 0 : goto cleanup;
2944 : }
2945 :
2946 0 : error = ext4_journal_get_write_access(handle, inode->i_sb,
2947 : iloc.bh, EXT4_JTR_NONE);
2948 0 : if (error) {
2949 0 : EXT4_ERROR_INODE(inode, "write access (error %d)",
2950 : error);
2951 0 : goto cleanup;
2952 : }
2953 :
2954 0 : header = IHDR(inode, ext4_raw_inode(&iloc));
2955 0 : if (header->h_magic == cpu_to_le32(EXT4_XATTR_MAGIC))
2956 0 : ext4_xattr_inode_dec_ref_all(handle, inode, iloc.bh,
2957 0 : IFIRST(header),
2958 : false /* block_csum */,
2959 : ea_inode_array,
2960 : extra_credits,
2961 : false /* skip_quota */);
2962 : }
2963 :
2964 0 : if (EXT4_I(inode)->i_file_acl) {
2965 0 : bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
2966 0 : if (IS_ERR(bh)) {
2967 0 : error = PTR_ERR(bh);
2968 0 : if (error == -EIO) {
2969 0 : EXT4_ERROR_INODE_ERR(inode, EIO,
2970 : "block %llu read error",
2971 : EXT4_I(inode)->i_file_acl);
2972 : }
2973 0 : bh = NULL;
2974 0 : goto cleanup;
2975 : }
2976 0 : error = ext4_xattr_check_block(inode, bh);
2977 0 : if (error)
2978 0 : goto cleanup;
2979 :
2980 0 : if (ext4_has_feature_ea_inode(inode->i_sb)) {
2981 0 : for (entry = BFIRST(bh); !IS_LAST_ENTRY(entry);
2982 0 : entry = EXT4_XATTR_NEXT(entry)) {
2983 0 : if (!entry->e_value_inum)
2984 0 : continue;
2985 0 : error = ext4_xattr_inode_iget(inode,
2986 : le32_to_cpu(entry->e_value_inum),
2987 0 : le32_to_cpu(entry->e_hash),
2988 : &ea_inode);
2989 0 : if (error)
2990 0 : continue;
2991 0 : ext4_xattr_inode_free_quota(inode, ea_inode,
2992 0 : le32_to_cpu(entry->e_value_size));
2993 0 : iput(ea_inode);
2994 : }
2995 :
2996 : }
2997 :
2998 0 : 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 0 : EXT4_I(inode)->i_file_acl = 0;
3005 0 : error = ext4_mark_inode_dirty(handle, inode);
3006 0 : if (error) {
3007 0 : EXT4_ERROR_INODE(inode, "mark inode dirty (error %d)",
3008 : error);
3009 0 : goto cleanup;
3010 : }
3011 0 : ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_XATTR, handle);
3012 : }
3013 : error = 0;
3014 0 : cleanup:
3015 0 : brelse(iloc.bh);
3016 0 : brelse(bh);
3017 0 : return error;
3018 : }
3019 :
3020 0 : void ext4_xattr_inode_array_free(struct ext4_xattr_inode_array *ea_inode_array)
3021 : {
3022 0 : int idx;
3023 :
3024 0 : if (ea_inode_array == NULL)
3025 : return;
3026 :
3027 0 : for (idx = 0; idx < ea_inode_array->count; ++idx)
3028 0 : iput(ea_inode_array->inodes[idx]);
3029 0 : 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 : */
3040 : static void
3041 0 : ext4_xattr_block_cache_insert(struct mb_cache *ea_block_cache,
3042 : struct buffer_head *bh)
3043 : {
3044 0 : struct ext4_xattr_header *header = BHDR(bh);
3045 0 : __u32 hash = le32_to_cpu(header->h_hash);
3046 0 : int reusable = le32_to_cpu(header->h_refcount) <
3047 : EXT4_XATTR_REFCOUNT_MAX;
3048 0 : int error;
3049 :
3050 0 : if (!ea_block_cache)
3051 : return;
3052 0 : error = mb_cache_entry_create(ea_block_cache, GFP_NOFS, hash,
3053 : bh->b_blocknr, reusable);
3054 0 : 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 : */
3069 : static int
3070 0 : ext4_xattr_cmp(struct ext4_xattr_header *header1,
3071 : struct ext4_xattr_header *header2)
3072 : {
3073 0 : struct ext4_xattr_entry *entry1, *entry2;
3074 :
3075 0 : entry1 = ENTRY(header1+1);
3076 0 : entry2 = ENTRY(header2+1);
3077 0 : while (!IS_LAST_ENTRY(entry1)) {
3078 0 : if (IS_LAST_ENTRY(entry2))
3079 : return 1;
3080 0 : if (entry1->e_hash != entry2->e_hash ||
3081 0 : entry1->e_name_index != entry2->e_name_index ||
3082 0 : entry1->e_name_len != entry2->e_name_len ||
3083 0 : entry1->e_value_size != entry2->e_value_size ||
3084 0 : entry1->e_value_inum != entry2->e_value_inum ||
3085 0 : memcmp(entry1->e_name, entry2->e_name, entry1->e_name_len))
3086 0 : return 1;
3087 0 : if (!entry1->e_value_inum &&
3088 0 : memcmp((char *)header1 + le16_to_cpu(entry1->e_value_offs),
3089 0 : (char *)header2 + le16_to_cpu(entry2->e_value_offs),
3090 0 : le32_to_cpu(entry1->e_value_size)))
3091 : return 1;
3092 :
3093 0 : entry1 = EXT4_XATTR_NEXT(entry1);
3094 0 : entry2 = EXT4_XATTR_NEXT(entry2);
3095 : }
3096 0 : if (!IS_LAST_ENTRY(entry2))
3097 0 : 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 : */
3109 : static struct buffer_head *
3110 0 : ext4_xattr_block_cache_find(struct inode *inode,
3111 : struct ext4_xattr_header *header,
3112 : struct mb_cache_entry **pce)
3113 : {
3114 0 : __u32 hash = le32_to_cpu(header->h_hash);
3115 0 : struct mb_cache_entry *ce;
3116 0 : struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
3117 :
3118 0 : if (!ea_block_cache)
3119 : return NULL;
3120 0 : if (!header->h_hash)
3121 : return NULL; /* never share */
3122 0 : ea_idebug(inode, "looking for cached blocks [%x]", (int)hash);
3123 0 : ce = mb_cache_entry_find_first(ea_block_cache, hash);
3124 0 : while (ce) {
3125 0 : struct buffer_head *bh;
3126 :
3127 0 : bh = ext4_sb_bread(inode->i_sb, ce->e_value, REQ_PRIO);
3128 0 : if (IS_ERR(bh)) {
3129 0 : if (PTR_ERR(bh) == -ENOMEM)
3130 : return NULL;
3131 0 : bh = NULL;
3132 0 : EXT4_ERROR_INODE(inode, "block %lu read error",
3133 : (unsigned long)ce->e_value);
3134 0 : } else if (ext4_xattr_cmp(header, BHDR(bh)) == 0) {
3135 0 : *pce = ce;
3136 0 : return bh;
3137 : }
3138 0 : brelse(bh);
3139 0 : 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 : */
3152 0 : static __le32 ext4_xattr_hash_entry(char *name, size_t name_len, __le32 *value,
3153 : size_t value_count)
3154 : {
3155 0 : __u32 hash = 0;
3156 :
3157 0 : while (name_len--) {
3158 0 : hash = (hash << NAME_HASH_SHIFT) ^
3159 : (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^
3160 0 : (unsigned char)*name++;
3161 : }
3162 0 : while (value_count--) {
3163 0 : hash = (hash << VALUE_HASH_SHIFT) ^
3164 : (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^
3165 0 : le32_to_cpu(*value++);
3166 : }
3167 0 : 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 : */
3175 0 : static __le32 ext4_xattr_hash_entry_signed(char *name, size_t name_len, __le32 *value, size_t value_count)
3176 : {
3177 0 : __u32 hash = 0;
3178 :
3179 0 : while (name_len--) {
3180 0 : hash = (hash << NAME_HASH_SHIFT) ^
3181 : (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^
3182 0 : (signed char)*name++;
3183 : }
3184 0 : while (value_count--) {
3185 0 : hash = (hash << VALUE_HASH_SHIFT) ^
3186 : (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^
3187 0 : le32_to_cpu(*value++);
3188 : }
3189 0 : 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 : */
3202 0 : static void ext4_xattr_rehash(struct ext4_xattr_header *header)
3203 : {
3204 0 : struct ext4_xattr_entry *here;
3205 0 : __u32 hash = 0;
3206 :
3207 0 : here = ENTRY(header+1);
3208 0 : while (!IS_LAST_ENTRY(here)) {
3209 0 : if (!here->e_hash) {
3210 : /* Block is not shared if an entry's hash value == 0 */
3211 : hash = 0;
3212 : break;
3213 : }
3214 0 : hash = (hash << BLOCK_HASH_SHIFT) ^
3215 : (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^
3216 : le32_to_cpu(here->e_hash);
3217 0 : here = EXT4_XATTR_NEXT(here);
3218 : }
3219 0 : header->h_hash = cpu_to_le32(hash);
3220 0 : }
3221 :
3222 : #undef BLOCK_HASH_SHIFT
3223 :
3224 : #define HASH_BUCKET_BITS 10
3225 :
3226 : struct mb_cache *
3227 0 : ext4_xattr_create_cache(void)
3228 : {
3229 0 : return mb_cache_create(HASH_BUCKET_BITS);
3230 : }
3231 :
3232 0 : void ext4_xattr_destroy_cache(struct mb_cache *cache)
3233 : {
3234 0 : if (cache)
3235 0 : mb_cache_destroy(cache);
3236 0 : }
3237 :
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