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Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
[cris-mirror.git] / fs / ext4 / namei.c
blobb1f21e3a076327df20e5218451ff1feec7e3a13f
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * linux/fs/ext4/namei.c
4 *
5 * Copyright (C) 1992, 1993, 1994, 1995
6 * Remy Card (card@masi.ibp.fr)
7 * Laboratoire MASI - Institut Blaise Pascal
8 * Universite Pierre et Marie Curie (Paris VI)
9 *
10 * from
11 *
12 * linux/fs/minix/namei.c
13 *
14 * Copyright (C) 1991, 1992 Linus Torvalds
15 *
16 * Big-endian to little-endian byte-swapping/bitmaps by
17 * David S. Miller (davem@caip.rutgers.edu), 1995
18 * Directory entry file type support and forward compatibility hooks
19 * for B-tree directories by Theodore Ts'o (tytso@mit.edu), 1998
20 * Hash Tree Directory indexing (c)
21 * Daniel Phillips, 2001
22 * Hash Tree Directory indexing porting
23 * Christopher Li, 2002
24 * Hash Tree Directory indexing cleanup
25 * Theodore Ts'o, 2002
26 */
27
28 #include <linux/fs.h>
29 #include <linux/pagemap.h>
30 #include <linux/time.h>
31 #include <linux/fcntl.h>
32 #include <linux/stat.h>
33 #include <linux/string.h>
34 #include <linux/quotaops.h>
35 #include <linux/buffer_head.h>
36 #include <linux/bio.h>
37 #include <linux/iversion.h>
38 #include "ext4.h"
39 #include "ext4_jbd2.h"
40
41 #include "xattr.h"
42 #include "acl.h"
43
44 #include <trace/events/ext4.h>
45 /*
46 * define how far ahead to read directories while searching them.
47 */
48 #define NAMEI_RA_CHUNKS 2
49 #define NAMEI_RA_BLOCKS 4
50 #define NAMEI_RA_SIZE (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS)
51
52 static struct buffer_head *ext4_append(handle_t *handle,
53 struct inode *inode,
54 ext4_lblk_t *block)
55 {
56 struct buffer_head *bh;
57 int err;
58
59 if (unlikely(EXT4_SB(inode->i_sb)->s_max_dir_size_kb &&
60 ((inode->i_size >> 10) >=
61 EXT4_SB(inode->i_sb)->s_max_dir_size_kb)))
62 return ERR_PTR(-ENOSPC);
63
64 *block = inode->i_size >> inode->i_sb->s_blocksize_bits;
65
66 bh = ext4_bread(handle, inode, *block, EXT4_GET_BLOCKS_CREATE);
67 if (IS_ERR(bh))
68 return bh;
69 inode->i_size += inode->i_sb->s_blocksize;
70 EXT4_I(inode)->i_disksize = inode->i_size;
71 BUFFER_TRACE(bh, "get_write_access");
72 err = ext4_journal_get_write_access(handle, bh);
73 if (err) {
74 brelse(bh);
75 ext4_std_error(inode->i_sb, err);
76 return ERR_PTR(err);
77 }
78 return bh;
79 }
80
81 static int ext4_dx_csum_verify(struct inode *inode,
82 struct ext4_dir_entry *dirent);
83
84 typedef enum {
85 EITHER, INDEX, DIRENT
86 } dirblock_type_t;
87
88 #define ext4_read_dirblock(inode, block, type) \
89 __ext4_read_dirblock((inode), (block), (type), __func__, __LINE__)
90
91 static struct buffer_head *__ext4_read_dirblock(struct inode *inode,
92 ext4_lblk_t block,
93 dirblock_type_t type,
94 const char *func,
95 unsigned int line)
96 {
97 struct buffer_head *bh;
98 struct ext4_dir_entry *dirent;
99 int is_dx_block = 0;
100
101 bh = ext4_bread(NULL, inode, block, 0);
102 if (IS_ERR(bh)) {
103 __ext4_warning(inode->i_sb, func, line,
104 "inode #%lu: lblock %lu: comm %s: "
105 "error %ld reading directory block",
106 inode->i_ino, (unsigned long)block,
107 current->comm, PTR_ERR(bh));
108
109 return bh;
110 }
111 if (!bh) {
112 ext4_error_inode(inode, func, line, block,
113 "Directory hole found");
114 return ERR_PTR(-EFSCORRUPTED);
115 }
116 dirent = (struct ext4_dir_entry *) bh->b_data;
117 /* Determine whether or not we have an index block */
118 if (is_dx(inode)) {
119 if (block == 0)
120 is_dx_block = 1;
121 else if (ext4_rec_len_from_disk(dirent->rec_len,
122 inode->i_sb->s_blocksize) ==
123 inode->i_sb->s_blocksize)
124 is_dx_block = 1;
125 }
126 if (!is_dx_block && type == INDEX) {
127 ext4_error_inode(inode, func, line, block,
128 "directory leaf block found instead of index block");
129 return ERR_PTR(-EFSCORRUPTED);
130 }
131 if (!ext4_has_metadata_csum(inode->i_sb) ||
132 buffer_verified(bh))
133 return bh;
134
135 /*
136 * An empty leaf block can get mistaken for a index block; for
137 * this reason, we can only check the index checksum when the
138 * caller is sure it should be an index block.
139 */
140 if (is_dx_block && type == INDEX) {
141 if (ext4_dx_csum_verify(inode, dirent))
142 set_buffer_verified(bh);
143 else {
144 ext4_error_inode(inode, func, line, block,
145 "Directory index failed checksum");
146 brelse(bh);
147 return ERR_PTR(-EFSBADCRC);
148 }
149 }
150 if (!is_dx_block) {
151 if (ext4_dirent_csum_verify(inode, dirent))
152 set_buffer_verified(bh);
153 else {
154 ext4_error_inode(inode, func, line, block,
155 "Directory block failed checksum");
156 brelse(bh);
157 return ERR_PTR(-EFSBADCRC);
158 }
159 }
160 return bh;
161 }
162
163 #ifndef assert
164 #define assert(test) J_ASSERT(test)
165 #endif
166
167 #ifdef DX_DEBUG
168 #define dxtrace(command) command
169 #else
170 #define dxtrace(command)
171 #endif
172
173 struct fake_dirent
174 {
175 __le32 inode;
176 __le16 rec_len;
177 u8 name_len;
178 u8 file_type;
179 };
180
181 struct dx_countlimit
182 {
183 __le16 limit;
184 __le16 count;
185 };
186
187 struct dx_entry
188 {
189 __le32 hash;
190 __le32 block;
191 };
192
193 /*
194 * dx_root_info is laid out so that if it should somehow get overlaid by a
195 * dirent the two low bits of the hash version will be zero. Therefore, the
196 * hash version mod 4 should never be 0. Sincerely, the paranoia department.
197 */
198
199 struct dx_root
200 {
201 struct fake_dirent dot;
202 char dot_name[4];
203 struct fake_dirent dotdot;
204 char dotdot_name[4];
205 struct dx_root_info
206 {
207 __le32 reserved_zero;
208 u8 hash_version;
209 u8 info_length; /* 8 */
210 u8 indirect_levels;
211 u8 unused_flags;
212 }
213 info;
214 struct dx_entry entries[0];
215 };
216
217 struct dx_node
218 {
219 struct fake_dirent fake;
220 struct dx_entry entries[0];
221 };
222
223
224 struct dx_frame
225 {
226 struct buffer_head *bh;
227 struct dx_entry *entries;
228 struct dx_entry *at;
229 };
230
231 struct dx_map_entry
232 {
233 u32 hash;
234 u16 offs;
235 u16 size;
236 };
237
238 /*
239 * This goes at the end of each htree block.
240 */
241 struct dx_tail {
242 u32 dt_reserved;
243 __le32 dt_checksum; /* crc32c(uuid+inum+dirblock) */
244 };
245
246 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
247 static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
248 static inline unsigned dx_get_hash(struct dx_entry *entry);
249 static void dx_set_hash(struct dx_entry *entry, unsigned value);
250 static unsigned dx_get_count(struct dx_entry *entries);
251 static unsigned dx_get_limit(struct dx_entry *entries);
252 static void dx_set_count(struct dx_entry *entries, unsigned value);
253 static void dx_set_limit(struct dx_entry *entries, unsigned value);
254 static unsigned dx_root_limit(struct inode *dir, unsigned infosize);
255 static unsigned dx_node_limit(struct inode *dir);
256 static struct dx_frame *dx_probe(struct ext4_filename *fname,
257 struct inode *dir,
258 struct dx_hash_info *hinfo,
259 struct dx_frame *frame);
260 static void dx_release(struct dx_frame *frames);
261 static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de,
262 unsigned blocksize, struct dx_hash_info *hinfo,
263 struct dx_map_entry map[]);
264 static void dx_sort_map(struct dx_map_entry *map, unsigned count);
265 static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to,
266 struct dx_map_entry *offsets, int count, unsigned blocksize);
267 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize);
268 static void dx_insert_block(struct dx_frame *frame,
269 u32 hash, ext4_lblk_t block);
270 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
271 struct dx_frame *frame,
272 struct dx_frame *frames,
273 __u32 *start_hash);
274 static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
275 struct ext4_filename *fname,
276 struct ext4_dir_entry_2 **res_dir);
277 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
278 struct inode *dir, struct inode *inode);
279
280 /* checksumming functions */
281 void initialize_dirent_tail(struct ext4_dir_entry_tail *t,
282 unsigned int blocksize)
283 {
284 memset(t, 0, sizeof(struct ext4_dir_entry_tail));
285 t->det_rec_len = ext4_rec_len_to_disk(
286 sizeof(struct ext4_dir_entry_tail), blocksize);
287 t->det_reserved_ft = EXT4_FT_DIR_CSUM;
288 }
289
290 /* Walk through a dirent block to find a checksum "dirent" at the tail */
291 static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode,
292 struct ext4_dir_entry *de)
293 {
294 struct ext4_dir_entry_tail *t;
295
296 #ifdef PARANOID
297 struct ext4_dir_entry *d, *top;
298
299 d = de;
300 top = (struct ext4_dir_entry *)(((void *)de) +
301 (EXT4_BLOCK_SIZE(inode->i_sb) -
302 sizeof(struct ext4_dir_entry_tail)));
303 while (d < top && d->rec_len)
304 d = (struct ext4_dir_entry *)(((void *)d) +
305 le16_to_cpu(d->rec_len));
306
307 if (d != top)
308 return NULL;
309
310 t = (struct ext4_dir_entry_tail *)d;
311 #else
312 t = EXT4_DIRENT_TAIL(de, EXT4_BLOCK_SIZE(inode->i_sb));
313 #endif
314
315 if (t->det_reserved_zero1 ||
316 le16_to_cpu(t->det_rec_len) != sizeof(struct ext4_dir_entry_tail) ||
317 t->det_reserved_zero2 ||
318 t->det_reserved_ft != EXT4_FT_DIR_CSUM)
319 return NULL;
320
321 return t;
322 }
323
324 static __le32 ext4_dirent_csum(struct inode *inode,
325 struct ext4_dir_entry *dirent, int size)
326 {
327 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
328 struct ext4_inode_info *ei = EXT4_I(inode);
329 __u32 csum;
330
331 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
332 return cpu_to_le32(csum);
333 }
334
335 #define warn_no_space_for_csum(inode) \
336 __warn_no_space_for_csum((inode), __func__, __LINE__)
337
338 static void __warn_no_space_for_csum(struct inode *inode, const char *func,
339 unsigned int line)
340 {
341 __ext4_warning_inode(inode, func, line,
342 "No space for directory leaf checksum. Please run e2fsck -D.");
343 }
344
345 int ext4_dirent_csum_verify(struct inode *inode, struct ext4_dir_entry *dirent)
346 {
347 struct ext4_dir_entry_tail *t;
348
349 if (!ext4_has_metadata_csum(inode->i_sb))
350 return 1;
351
352 t = get_dirent_tail(inode, dirent);
353 if (!t) {
354 warn_no_space_for_csum(inode);
355 return 0;
356 }
357
358 if (t->det_checksum != ext4_dirent_csum(inode, dirent,
359 (void *)t - (void *)dirent))
360 return 0;
361
362 return 1;
363 }
364
365 static void ext4_dirent_csum_set(struct inode *inode,
366 struct ext4_dir_entry *dirent)
367 {
368 struct ext4_dir_entry_tail *t;
369
370 if (!ext4_has_metadata_csum(inode->i_sb))
371 return;
372
373 t = get_dirent_tail(inode, dirent);
374 if (!t) {
375 warn_no_space_for_csum(inode);
376 return;
377 }
378
379 t->det_checksum = ext4_dirent_csum(inode, dirent,
380 (void *)t - (void *)dirent);
381 }
382
383 int ext4_handle_dirty_dirent_node(handle_t *handle,
384 struct inode *inode,
385 struct buffer_head *bh)
386 {
387 ext4_dirent_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
388 return ext4_handle_dirty_metadata(handle, inode, bh);
389 }
390
391 static struct dx_countlimit *get_dx_countlimit(struct inode *inode,
392 struct ext4_dir_entry *dirent,
393 int *offset)
394 {
395 struct ext4_dir_entry *dp;
396 struct dx_root_info *root;
397 int count_offset;
398
399 if (le16_to_cpu(dirent->rec_len) == EXT4_BLOCK_SIZE(inode->i_sb))
400 count_offset = 8;
401 else if (le16_to_cpu(dirent->rec_len) == 12) {
402 dp = (struct ext4_dir_entry *)(((void *)dirent) + 12);
403 if (le16_to_cpu(dp->rec_len) !=
404 EXT4_BLOCK_SIZE(inode->i_sb) - 12)
405 return NULL;
406 root = (struct dx_root_info *)(((void *)dp + 12));
407 if (root->reserved_zero ||
408 root->info_length != sizeof(struct dx_root_info))
409 return NULL;
410 count_offset = 32;
411 } else
412 return NULL;
413
414 if (offset)
415 *offset = count_offset;
416 return (struct dx_countlimit *)(((void *)dirent) + count_offset);
417 }
418
419 static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent,
420 int count_offset, int count, struct dx_tail *t)
421 {
422 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
423 struct ext4_inode_info *ei = EXT4_I(inode);
424 __u32 csum;
425 int size;
426 __u32 dummy_csum = 0;
427 int offset = offsetof(struct dx_tail, dt_checksum);
428
429 size = count_offset + (count * sizeof(struct dx_entry));
430 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
431 csum = ext4_chksum(sbi, csum, (__u8 *)t, offset);
432 csum = ext4_chksum(sbi, csum, (__u8 *)&dummy_csum, sizeof(dummy_csum));
433
434 return cpu_to_le32(csum);
435 }
436
437 static int ext4_dx_csum_verify(struct inode *inode,
438 struct ext4_dir_entry *dirent)
439 {
440 struct dx_countlimit *c;
441 struct dx_tail *t;
442 int count_offset, limit, count;
443
444 if (!ext4_has_metadata_csum(inode->i_sb))
445 return 1;
446
447 c = get_dx_countlimit(inode, dirent, &count_offset);
448 if (!c) {
449 EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D.");
450 return 0;
451 }
452 limit = le16_to_cpu(c->limit);
453 count = le16_to_cpu(c->count);
454 if (count_offset + (limit * sizeof(struct dx_entry)) >
455 EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
456 warn_no_space_for_csum(inode);
457 return 0;
458 }
459 t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
460
461 if (t->dt_checksum != ext4_dx_csum(inode, dirent, count_offset,
462 count, t))
463 return 0;
464 return 1;
465 }
466
467 static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent)
468 {
469 struct dx_countlimit *c;
470 struct dx_tail *t;
471 int count_offset, limit, count;
472
473 if (!ext4_has_metadata_csum(inode->i_sb))
474 return;
475
476 c = get_dx_countlimit(inode, dirent, &count_offset);
477 if (!c) {
478 EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D.");
479 return;
480 }
481 limit = le16_to_cpu(c->limit);
482 count = le16_to_cpu(c->count);
483 if (count_offset + (limit * sizeof(struct dx_entry)) >
484 EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
485 warn_no_space_for_csum(inode);
486 return;
487 }
488 t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
489
490 t->dt_checksum = ext4_dx_csum(inode, dirent, count_offset, count, t);
491 }
492
493 static inline int ext4_handle_dirty_dx_node(handle_t *handle,
494 struct inode *inode,
495 struct buffer_head *bh)
496 {
497 ext4_dx_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
498 return ext4_handle_dirty_metadata(handle, inode, bh);
499 }
500
501 /*
502 * p is at least 6 bytes before the end of page
503 */
504 static inline struct ext4_dir_entry_2 *
505 ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
506 {
507 return (struct ext4_dir_entry_2 *)((char *)p +
508 ext4_rec_len_from_disk(p->rec_len, blocksize));
509 }
510
511 /*
512 * Future: use high four bits of block for coalesce-on-delete flags
513 * Mask them off for now.
514 */
515
516 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
517 {
518 return le32_to_cpu(entry->block) & 0x0fffffff;
519 }
520
521 static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
522 {
523 entry->block = cpu_to_le32(value);
524 }
525
526 static inline unsigned dx_get_hash(struct dx_entry *entry)
527 {
528 return le32_to_cpu(entry->hash);
529 }
530
531 static inline void dx_set_hash(struct dx_entry *entry, unsigned value)
532 {
533 entry->hash = cpu_to_le32(value);
534 }
535
536 static inline unsigned dx_get_count(struct dx_entry *entries)
537 {
538 return le16_to_cpu(((struct dx_countlimit *) entries)->count);
539 }
540
541 static inline unsigned dx_get_limit(struct dx_entry *entries)
542 {
543 return le16_to_cpu(((struct dx_countlimit *) entries)->limit);
544 }
545
546 static inline void dx_set_count(struct dx_entry *entries, unsigned value)
547 {
548 ((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
549 }
550
551 static inline void dx_set_limit(struct dx_entry *entries, unsigned value)
552 {
553 ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
554 }
555
556 static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
557 {
558 unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
559 EXT4_DIR_REC_LEN(2) - infosize;
560
561 if (ext4_has_metadata_csum(dir->i_sb))
562 entry_space -= sizeof(struct dx_tail);
563 return entry_space / sizeof(struct dx_entry);
564 }
565
566 static inline unsigned dx_node_limit(struct inode *dir)
567 {
568 unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);
569
570 if (ext4_has_metadata_csum(dir->i_sb))
571 entry_space -= sizeof(struct dx_tail);
572 return entry_space / sizeof(struct dx_entry);
573 }
574
575 /*
576 * Debug
577 */
578 #ifdef DX_DEBUG
579 static void dx_show_index(char * label, struct dx_entry *entries)
580 {
581 int i, n = dx_get_count (entries);
582 printk(KERN_DEBUG "%s index", label);
583 for (i = 0; i < n; i++) {
584 printk(KERN_CONT " %x->%lu",
585 i ? dx_get_hash(entries + i) : 0,
586 (unsigned long)dx_get_block(entries + i));
587 }
588 printk(KERN_CONT "\n");
589 }
590
591 struct stats
592 {
593 unsigned names;
594 unsigned space;
595 unsigned bcount;
596 };
597
598 static struct stats dx_show_leaf(struct inode *dir,
599 struct dx_hash_info *hinfo,
600 struct ext4_dir_entry_2 *de,
601 int size, int show_names)
602 {
603 unsigned names = 0, space = 0;
604 char *base = (char *) de;
605 struct dx_hash_info h = *hinfo;
606
607 printk("names: ");
608 while ((char *) de < base + size)
609 {
610 if (de->inode)
611 {
612 if (show_names)
613 {
614 #ifdef CONFIG_EXT4_FS_ENCRYPTION
615 int len;
616 char *name;
617 struct fscrypt_str fname_crypto_str =
618 FSTR_INIT(NULL, 0);
619 int res = 0;
620
621 name = de->name;
622 len = de->name_len;
623 if (ext4_encrypted_inode(dir))
624 res = fscrypt_get_encryption_info(dir);
625 if (res) {
626 printk(KERN_WARNING "Error setting up"
627 " fname crypto: %d\n", res);
628 }
629 if (!fscrypt_has_encryption_key(dir)) {
630 /* Directory is not encrypted */
631 ext4fs_dirhash(de->name,
632 de->name_len, &h);
633 printk("%*.s:(U)%x.%u ", len,
634 name, h.hash,
635 (unsigned) ((char *) de
636 - base));
637 } else {
638 struct fscrypt_str de_name =
639 FSTR_INIT(name, len);
640
641 /* Directory is encrypted */
642 res = fscrypt_fname_alloc_buffer(
643 dir, len,
644 &fname_crypto_str);
645 if (res)
646 printk(KERN_WARNING "Error "
647 "allocating crypto "
648 "buffer--skipping "
649 "crypto\n");
650 res = fscrypt_fname_disk_to_usr(dir,
651 0, 0, &de_name,
652 &fname_crypto_str);
653 if (res) {
654 printk(KERN_WARNING "Error "
655 "converting filename "
656 "from disk to usr"
657 "\n");
658 name = "??";
659 len = 2;
660 } else {
661 name = fname_crypto_str.name;
662 len = fname_crypto_str.len;
663 }
664 ext4fs_dirhash(de->name, de->name_len,
665 &h);
666 printk("%*.s:(E)%x.%u ", len, name,
667 h.hash, (unsigned) ((char *) de
668 - base));
669 fscrypt_fname_free_buffer(
670 &fname_crypto_str);
671 }
672 #else
673 int len = de->name_len;
674 char *name = de->name;
675 ext4fs_dirhash(de->name, de->name_len, &h);
676 printk("%*.s:%x.%u ", len, name, h.hash,
677 (unsigned) ((char *) de - base));
678 #endif
679 }
680 space += EXT4_DIR_REC_LEN(de->name_len);
681 names++;
682 }
683 de = ext4_next_entry(de, size);
684 }
685 printk(KERN_CONT "(%i)\n", names);
686 return (struct stats) { names, space, 1 };
687 }
688
689 struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
690 struct dx_entry *entries, int levels)
691 {
692 unsigned blocksize = dir->i_sb->s_blocksize;
693 unsigned count = dx_get_count(entries), names = 0, space = 0, i;
694 unsigned bcount = 0;
695 struct buffer_head *bh;
696 printk("%i indexed blocks...\n", count);
697 for (i = 0; i < count; i++, entries++)
698 {
699 ext4_lblk_t block = dx_get_block(entries);
700 ext4_lblk_t hash = i ? dx_get_hash(entries): 0;
701 u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
702 struct stats stats;
703 printk("%s%3u:%03u hash %8x/%8x ",levels?"":" ", i, block, hash, range);
704 bh = ext4_bread(NULL,dir, block, 0);
705 if (!bh || IS_ERR(bh))
706 continue;
707 stats = levels?
708 dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
709 dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *)
710 bh->b_data, blocksize, 0);
711 names += stats.names;
712 space += stats.space;
713 bcount += stats.bcount;
714 brelse(bh);
715 }
716 if (bcount)
717 printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n",
718 levels ? "" : " ", names, space/bcount,
719 (space/bcount)*100/blocksize);
720 return (struct stats) { names, space, bcount};
721 }
722 #endif /* DX_DEBUG */
723
724 /*
725 * Probe for a directory leaf block to search.
726 *
727 * dx_probe can return ERR_BAD_DX_DIR, which means there was a format
728 * error in the directory index, and the caller should fall back to
729 * searching the directory normally. The callers of dx_probe **MUST**
730 * check for this error code, and make sure it never gets reflected
731 * back to userspace.
732 */
733 static struct dx_frame *
734 dx_probe(struct ext4_filename *fname, struct inode *dir,
735 struct dx_hash_info *hinfo, struct dx_frame *frame_in)
736 {
737 unsigned count, indirect;
738 struct dx_entry *at, *entries, *p, *q, *m;
739 struct dx_root *root;
740 struct dx_frame *frame = frame_in;
741 struct dx_frame *ret_err = ERR_PTR(ERR_BAD_DX_DIR);
742 u32 hash;
743
744 memset(frame_in, 0, EXT4_HTREE_LEVEL * sizeof(frame_in[0]));
745 frame->bh = ext4_read_dirblock(dir, 0, INDEX);
746 if (IS_ERR(frame->bh))
747 return (struct dx_frame *) frame->bh;
748
749 root = (struct dx_root *) frame->bh->b_data;
750 if (root->info.hash_version != DX_HASH_TEA &&
751 root->info.hash_version != DX_HASH_HALF_MD4 &&
752 root->info.hash_version != DX_HASH_LEGACY) {
753 ext4_warning_inode(dir, "Unrecognised inode hash code %u",
754 root->info.hash_version);
755 goto fail;
756 }
757 if (fname)
758 hinfo = &fname->hinfo;
759 hinfo->hash_version = root->info.hash_version;
760 if (hinfo->hash_version <= DX_HASH_TEA)
761 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
762 hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
763 if (fname && fname_name(fname))
764 ext4fs_dirhash(fname_name(fname), fname_len(fname), hinfo);
765 hash = hinfo->hash;
766
767 if (root->info.unused_flags & 1) {
768 ext4_warning_inode(dir, "Unimplemented hash flags: %#06x",
769 root->info.unused_flags);
770 goto fail;
771 }
772
773 indirect = root->info.indirect_levels;
774 if (indirect >= ext4_dir_htree_level(dir->i_sb)) {
775 ext4_warning(dir->i_sb,
776 "Directory (ino: %lu) htree depth %#06x exceed"
777 "supported value", dir->i_ino,
778 ext4_dir_htree_level(dir->i_sb));
779 if (ext4_dir_htree_level(dir->i_sb) < EXT4_HTREE_LEVEL) {
780 ext4_warning(dir->i_sb, "Enable large directory "
781 "feature to access it");
782 }
783 goto fail;
784 }
785
786 entries = (struct dx_entry *)(((char *)&root->info) +
787 root->info.info_length);
788
789 if (dx_get_limit(entries) != dx_root_limit(dir,
790 root->info.info_length)) {
791 ext4_warning_inode(dir, "dx entry: limit %u != root limit %u",
792 dx_get_limit(entries),
793 dx_root_limit(dir, root->info.info_length));
794 goto fail;
795 }
796
797 dxtrace(printk("Look up %x", hash));
798 while (1) {
799 count = dx_get_count(entries);
800 if (!count || count > dx_get_limit(entries)) {
801 ext4_warning_inode(dir,
802 "dx entry: count %u beyond limit %u",
803 count, dx_get_limit(entries));
804 goto fail;
805 }
806
807 p = entries + 1;
808 q = entries + count - 1;
809 while (p <= q) {
810 m = p + (q - p) / 2;
811 dxtrace(printk(KERN_CONT "."));
812 if (dx_get_hash(m) > hash)
813 q = m - 1;
814 else
815 p = m + 1;
816 }
817
818 if (0) { // linear search cross check
819 unsigned n = count - 1;
820 at = entries;
821 while (n--)
822 {
823 dxtrace(printk(KERN_CONT ","));
824 if (dx_get_hash(++at) > hash)
825 {
826 at--;
827 break;
828 }
829 }
830 assert (at == p - 1);
831 }
832
833 at = p - 1;
834 dxtrace(printk(KERN_CONT " %x->%u\n",
835 at == entries ? 0 : dx_get_hash(at),
836 dx_get_block(at)));
837 frame->entries = entries;
838 frame->at = at;
839 if (!indirect--)
840 return frame;
841 frame++;
842 frame->bh = ext4_read_dirblock(dir, dx_get_block(at), INDEX);
843 if (IS_ERR(frame->bh)) {
844 ret_err = (struct dx_frame *) frame->bh;
845 frame->bh = NULL;
846 goto fail;
847 }
848 entries = ((struct dx_node *) frame->bh->b_data)->entries;
849
850 if (dx_get_limit(entries) != dx_node_limit(dir)) {
851 ext4_warning_inode(dir,
852 "dx entry: limit %u != node limit %u",
853 dx_get_limit(entries), dx_node_limit(dir));
854 goto fail;
855 }
856 }
857 fail:
858 while (frame >= frame_in) {
859 brelse(frame->bh);
860 frame--;
861 }
862
863 if (ret_err == ERR_PTR(ERR_BAD_DX_DIR))
864 ext4_warning_inode(dir,
865 "Corrupt directory, running e2fsck is recommended");
866 return ret_err;
867 }
868
869 static void dx_release(struct dx_frame *frames)
870 {
871 struct dx_root_info *info;
872 int i;
873
874 if (frames[0].bh == NULL)
875 return;
876
877 info = &((struct dx_root *)frames[0].bh->b_data)->info;
878 for (i = 0; i <= info->indirect_levels; i++) {
879 if (frames[i].bh == NULL)
880 break;
881 brelse(frames[i].bh);
882 frames[i].bh = NULL;
883 }
884 }
885
886 /*
887 * This function increments the frame pointer to search the next leaf
888 * block, and reads in the necessary intervening nodes if the search
889 * should be necessary. Whether or not the search is necessary is
890 * controlled by the hash parameter. If the hash value is even, then
891 * the search is only continued if the next block starts with that
892 * hash value. This is used if we are searching for a specific file.
893 *
894 * If the hash value is HASH_NB_ALWAYS, then always go to the next block.
895 *
896 * This function returns 1 if the caller should continue to search,
897 * or 0 if it should not. If there is an error reading one of the
898 * index blocks, it will a negative error code.
899 *
900 * If start_hash is non-null, it will be filled in with the starting
901 * hash of the next page.
902 */
903 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
904 struct dx_frame *frame,
905 struct dx_frame *frames,
906 __u32 *start_hash)
907 {
908 struct dx_frame *p;
909 struct buffer_head *bh;
910 int num_frames = 0;
911 __u32 bhash;
912
913 p = frame;
914 /*
915 * Find the next leaf page by incrementing the frame pointer.
916 * If we run out of entries in the interior node, loop around and
917 * increment pointer in the parent node. When we break out of
918 * this loop, num_frames indicates the number of interior
919 * nodes need to be read.
920 */
921 while (1) {
922 if (++(p->at) < p->entries + dx_get_count(p->entries))
923 break;
924 if (p == frames)
925 return 0;
926 num_frames++;
927 p--;
928 }
929
930 /*
931 * If the hash is 1, then continue only if the next page has a
932 * continuation hash of any value. This is used for readdir
933 * handling. Otherwise, check to see if the hash matches the
934 * desired contiuation hash. If it doesn't, return since
935 * there's no point to read in the successive index pages.
936 */
937 bhash = dx_get_hash(p->at);
938 if (start_hash)
939 *start_hash = bhash;
940 if ((hash & 1) == 0) {
941 if ((bhash & ~1) != hash)
942 return 0;
943 }
944 /*
945 * If the hash is HASH_NB_ALWAYS, we always go to the next
946 * block so no check is necessary
947 */
948 while (num_frames--) {
949 bh = ext4_read_dirblock(dir, dx_get_block(p->at), INDEX);
950 if (IS_ERR(bh))
951 return PTR_ERR(bh);
952 p++;
953 brelse(p->bh);
954 p->bh = bh;
955 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
956 }
957 return 1;
958 }
959
960
961 /*
962 * This function fills a red-black tree with information from a
963 * directory block. It returns the number directory entries loaded
964 * into the tree. If there is an error it is returned in err.
965 */
966 static int htree_dirblock_to_tree(struct file *dir_file,
967 struct inode *dir, ext4_lblk_t block,
968 struct dx_hash_info *hinfo,
969 __u32 start_hash, __u32 start_minor_hash)
970 {
971 struct buffer_head *bh;
972 struct ext4_dir_entry_2 *de, *top;
973 int err = 0, count = 0;
974 struct fscrypt_str fname_crypto_str = FSTR_INIT(NULL, 0), tmp_str;
975
976 dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
977 (unsigned long)block));
978 bh = ext4_read_dirblock(dir, block, DIRENT);
979 if (IS_ERR(bh))
980 return PTR_ERR(bh);
981
982 de = (struct ext4_dir_entry_2 *) bh->b_data;
983 top = (struct ext4_dir_entry_2 *) ((char *) de +
984 dir->i_sb->s_blocksize -
985 EXT4_DIR_REC_LEN(0));
986 #ifdef CONFIG_EXT4_FS_ENCRYPTION
987 /* Check if the directory is encrypted */
988 if (ext4_encrypted_inode(dir)) {
989 err = fscrypt_get_encryption_info(dir);
990 if (err < 0) {
991 brelse(bh);
992 return err;
993 }
994 err = fscrypt_fname_alloc_buffer(dir, EXT4_NAME_LEN,
995 &fname_crypto_str);
996 if (err < 0) {
997 brelse(bh);
998 return err;
999 }
1000 }
1001 #endif
1002 for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) {
1003 if (ext4_check_dir_entry(dir, NULL, de, bh,
1004 bh->b_data, bh->b_size,
1005 (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
1006 + ((char *)de - bh->b_data))) {
1007 /* silently ignore the rest of the block */
1008 break;
1009 }
1010 ext4fs_dirhash(de->name, de->name_len, hinfo);
1011 if ((hinfo->hash < start_hash) ||
1012 ((hinfo->hash == start_hash) &&
1013 (hinfo->minor_hash < start_minor_hash)))
1014 continue;
1015 if (de->inode == 0)
1016 continue;
1017 if (!ext4_encrypted_inode(dir)) {
1018 tmp_str.name = de->name;
1019 tmp_str.len = de->name_len;
1020 err = ext4_htree_store_dirent(dir_file,
1021 hinfo->hash, hinfo->minor_hash, de,
1022 &tmp_str);
1023 } else {
1024 int save_len = fname_crypto_str.len;
1025 struct fscrypt_str de_name = FSTR_INIT(de->name,
1026 de->name_len);
1027
1028 /* Directory is encrypted */
1029 err = fscrypt_fname_disk_to_usr(dir, hinfo->hash,
1030 hinfo->minor_hash, &de_name,
1031 &fname_crypto_str);
1032 if (err) {
1033 count = err;
1034 goto errout;
1035 }
1036 err = ext4_htree_store_dirent(dir_file,
1037 hinfo->hash, hinfo->minor_hash, de,
1038 &fname_crypto_str);
1039 fname_crypto_str.len = save_len;
1040 }
1041 if (err != 0) {
1042 count = err;
1043 goto errout;
1044 }
1045 count++;
1046 }
1047 errout:
1048 brelse(bh);
1049 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1050 fscrypt_fname_free_buffer(&fname_crypto_str);
1051 #endif
1052 return count;
1053 }
1054
1055
1056 /*
1057 * This function fills a red-black tree with information from a
1058 * directory. We start scanning the directory in hash order, starting
1059 * at start_hash and start_minor_hash.
1060 *
1061 * This function returns the number of entries inserted into the tree,
1062 * or a negative error code.
1063 */
1064 int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
1065 __u32 start_minor_hash, __u32 *next_hash)
1066 {
1067 struct dx_hash_info hinfo;
1068 struct ext4_dir_entry_2 *de;
1069 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
1070 struct inode *dir;
1071 ext4_lblk_t block;
1072 int count = 0;
1073 int ret, err;
1074 __u32 hashval;
1075 struct fscrypt_str tmp_str;
1076
1077 dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
1078 start_hash, start_minor_hash));
1079 dir = file_inode(dir_file);
1080 if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) {
1081 hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
1082 if (hinfo.hash_version <= DX_HASH_TEA)
1083 hinfo.hash_version +=
1084 EXT4_SB(dir->i_sb)->s_hash_unsigned;
1085 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
1086 if (ext4_has_inline_data(dir)) {
1087 int has_inline_data = 1;
1088 count = htree_inlinedir_to_tree(dir_file, dir, 0,
1089 &hinfo, start_hash,
1090 start_minor_hash,
1091 &has_inline_data);
1092 if (has_inline_data) {
1093 *next_hash = ~0;
1094 return count;
1095 }
1096 }
1097 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
1098 start_hash, start_minor_hash);
1099 *next_hash = ~0;
1100 return count;
1101 }
1102 hinfo.hash = start_hash;
1103 hinfo.minor_hash = 0;
1104 frame = dx_probe(NULL, dir, &hinfo, frames);
1105 if (IS_ERR(frame))
1106 return PTR_ERR(frame);
1107
1108 /* Add '.' and '..' from the htree header */
1109 if (!start_hash && !start_minor_hash) {
1110 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
1111 tmp_str.name = de->name;
1112 tmp_str.len = de->name_len;
1113 err = ext4_htree_store_dirent(dir_file, 0, 0,
1114 de, &tmp_str);
1115 if (err != 0)
1116 goto errout;
1117 count++;
1118 }
1119 if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
1120 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
1121 de = ext4_next_entry(de, dir->i_sb->s_blocksize);
1122 tmp_str.name = de->name;
1123 tmp_str.len = de->name_len;
1124 err = ext4_htree_store_dirent(dir_file, 2, 0,
1125 de, &tmp_str);
1126 if (err != 0)
1127 goto errout;
1128 count++;
1129 }
1130
1131 while (1) {
1132 if (fatal_signal_pending(current)) {
1133 err = -ERESTARTSYS;
1134 goto errout;
1135 }
1136 cond_resched();
1137 block = dx_get_block(frame->at);
1138 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
1139 start_hash, start_minor_hash);
1140 if (ret < 0) {
1141 err = ret;
1142 goto errout;
1143 }
1144 count += ret;
1145 hashval = ~0;
1146 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
1147 frame, frames, &hashval);
1148 *next_hash = hashval;
1149 if (ret < 0) {
1150 err = ret;
1151 goto errout;
1152 }
1153 /*
1154 * Stop if: (a) there are no more entries, or
1155 * (b) we have inserted at least one entry and the
1156 * next hash value is not a continuation
1157 */
1158 if ((ret == 0) ||
1159 (count && ((hashval & 1) == 0)))
1160 break;
1161 }
1162 dx_release(frames);
1163 dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, "
1164 "next hash: %x\n", count, *next_hash));
1165 return count;
1166 errout:
1167 dx_release(frames);
1168 return (err);
1169 }
1170
1171 static inline int search_dirblock(struct buffer_head *bh,
1172 struct inode *dir,
1173 struct ext4_filename *fname,
1174 unsigned int offset,
1175 struct ext4_dir_entry_2 **res_dir)
1176 {
1177 return ext4_search_dir(bh, bh->b_data, dir->i_sb->s_blocksize, dir,
1178 fname, offset, res_dir);
1179 }
1180
1181 /*
1182 * Directory block splitting, compacting
1183 */
1184
1185 /*
1186 * Create map of hash values, offsets, and sizes, stored at end of block.
1187 * Returns number of entries mapped.
1188 */
1189 static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de,
1190 unsigned blocksize, struct dx_hash_info *hinfo,
1191 struct dx_map_entry *map_tail)
1192 {
1193 int count = 0;
1194 char *base = (char *) de;
1195 struct dx_hash_info h = *hinfo;
1196
1197 while ((char *) de < base + blocksize) {
1198 if (de->name_len && de->inode) {
1199 ext4fs_dirhash(de->name, de->name_len, &h);
1200 map_tail--;
1201 map_tail->hash = h.hash;
1202 map_tail->offs = ((char *) de - base)>>2;
1203 map_tail->size = le16_to_cpu(de->rec_len);
1204 count++;
1205 cond_resched();
1206 }
1207 /* XXX: do we need to check rec_len == 0 case? -Chris */
1208 de = ext4_next_entry(de, blocksize);
1209 }
1210 return count;
1211 }
1212
1213 /* Sort map by hash value */
1214 static void dx_sort_map (struct dx_map_entry *map, unsigned count)
1215 {
1216 struct dx_map_entry *p, *q, *top = map + count - 1;
1217 int more;
1218 /* Combsort until bubble sort doesn't suck */
1219 while (count > 2) {
1220 count = count*10/13;
1221 if (count - 9 < 2) /* 9, 10 -> 11 */
1222 count = 11;
1223 for (p = top, q = p - count; q >= map; p--, q--)
1224 if (p->hash < q->hash)
1225 swap(*p, *q);
1226 }
1227 /* Garden variety bubble sort */
1228 do {
1229 more = 0;
1230 q = top;
1231 while (q-- > map) {
1232 if (q[1].hash >= q[0].hash)
1233 continue;
1234 swap(*(q+1), *q);
1235 more = 1;
1236 }
1237 } while(more);
1238 }
1239
1240 static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
1241 {
1242 struct dx_entry *entries = frame->entries;
1243 struct dx_entry *old = frame->at, *new = old + 1;
1244 int count = dx_get_count(entries);
1245
1246 assert(count < dx_get_limit(entries));
1247 assert(old < entries + count);
1248 memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
1249 dx_set_hash(new, hash);
1250 dx_set_block(new, block);
1251 dx_set_count(entries, count + 1);
1252 }
1253
1254 /*
1255 * Test whether a directory entry matches the filename being searched for.
1256 *
1257 * Return: %true if the directory entry matches, otherwise %false.
1258 */
1259 static inline bool ext4_match(const struct ext4_filename *fname,
1260 const struct ext4_dir_entry_2 *de)
1261 {
1262 struct fscrypt_name f;
1263
1264 if (!de->inode)
1265 return false;
1266
1267 f.usr_fname = fname->usr_fname;
1268 f.disk_name = fname->disk_name;
1269 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1270 f.crypto_buf = fname->crypto_buf;
1271 #endif
1272 return fscrypt_match_name(&f, de->name, de->name_len);
1273 }
1274
1275 /*
1276 * Returns 0 if not found, -1 on failure, and 1 on success
1277 */
1278 int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size,
1279 struct inode *dir, struct ext4_filename *fname,
1280 unsigned int offset, struct ext4_dir_entry_2 **res_dir)
1281 {
1282 struct ext4_dir_entry_2 * de;
1283 char * dlimit;
1284 int de_len;
1285
1286 de = (struct ext4_dir_entry_2 *)search_buf;
1287 dlimit = search_buf + buf_size;
1288 while ((char *) de < dlimit) {
1289 /* this code is executed quadratically often */
1290 /* do minimal checking `by hand' */
1291 if ((char *) de + de->name_len <= dlimit &&
1292 ext4_match(fname, de)) {
1293 /* found a match - just to be sure, do
1294 * a full check */
1295 if (ext4_check_dir_entry(dir, NULL, de, bh, bh->b_data,
1296 bh->b_size, offset))
1297 return -1;
1298 *res_dir = de;
1299 return 1;
1300 }
1301 /* prevent looping on a bad block */
1302 de_len = ext4_rec_len_from_disk(de->rec_len,
1303 dir->i_sb->s_blocksize);
1304 if (de_len <= 0)
1305 return -1;
1306 offset += de_len;
1307 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
1308 }
1309 return 0;
1310 }
1311
1312 static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block,
1313 struct ext4_dir_entry *de)
1314 {
1315 struct super_block *sb = dir->i_sb;
1316
1317 if (!is_dx(dir))
1318 return 0;
1319 if (block == 0)
1320 return 1;
1321 if (de->inode == 0 &&
1322 ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) ==
1323 sb->s_blocksize)
1324 return 1;
1325 return 0;
1326 }
1327
1328 /*
1329 * ext4_find_entry()
1330 *
1331 * finds an entry in the specified directory with the wanted name. It
1332 * returns the cache buffer in which the entry was found, and the entry
1333 * itself (as a parameter - res_dir). It does NOT read the inode of the
1334 * entry - you'll have to do that yourself if you want to.
1335 *
1336 * The returned buffer_head has ->b_count elevated. The caller is expected
1337 * to brelse() it when appropriate.
1338 */
1339 static struct buffer_head * ext4_find_entry (struct inode *dir,
1340 const struct qstr *d_name,
1341 struct ext4_dir_entry_2 **res_dir,
1342 int *inlined)
1343 {
1344 struct super_block *sb;
1345 struct buffer_head *bh_use[NAMEI_RA_SIZE];
1346 struct buffer_head *bh, *ret = NULL;
1347 ext4_lblk_t start, block;
1348 const u8 *name = d_name->name;
1349 size_t ra_max = 0; /* Number of bh's in the readahead
1350 buffer, bh_use[] */
1351 size_t ra_ptr = 0; /* Current index into readahead
1352 buffer */
1353 ext4_lblk_t nblocks;
1354 int i, namelen, retval;
1355 struct ext4_filename fname;
1356
1357 *res_dir = NULL;
1358 sb = dir->i_sb;
1359 namelen = d_name->len;
1360 if (namelen > EXT4_NAME_LEN)
1361 return NULL;
1362
1363 retval = ext4_fname_setup_filename(dir, d_name, 1, &fname);
1364 if (retval == -ENOENT)
1365 return NULL;
1366 if (retval)
1367 return ERR_PTR(retval);
1368
1369 if (ext4_has_inline_data(dir)) {
1370 int has_inline_data = 1;
1371 ret = ext4_find_inline_entry(dir, &fname, res_dir,
1372 &has_inline_data);
1373 if (has_inline_data) {
1374 if (inlined)
1375 *inlined = 1;
1376 goto cleanup_and_exit;
1377 }
1378 }
1379
1380 if ((namelen <= 2) && (name[0] == '.') &&
1381 (name[1] == '.' || name[1] == '\0')) {
1382 /*
1383 * "." or ".." will only be in the first block
1384 * NFS may look up ".."; "." should be handled by the VFS
1385 */
1386 block = start = 0;
1387 nblocks = 1;
1388 goto restart;
1389 }
1390 if (is_dx(dir)) {
1391 ret = ext4_dx_find_entry(dir, &fname, res_dir);
1392 /*
1393 * On success, or if the error was file not found,
1394 * return. Otherwise, fall back to doing a search the
1395 * old fashioned way.
1396 */
1397 if (!IS_ERR(ret) || PTR_ERR(ret) != ERR_BAD_DX_DIR)
1398 goto cleanup_and_exit;
1399 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
1400 "falling back\n"));
1401 }
1402 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1403 if (!nblocks) {
1404 ret = NULL;
1405 goto cleanup_and_exit;
1406 }
1407 start = EXT4_I(dir)->i_dir_start_lookup;
1408 if (start >= nblocks)
1409 start = 0;
1410 block = start;
1411 restart:
1412 do {
1413 /*
1414 * We deal with the read-ahead logic here.
1415 */
1416 if (ra_ptr >= ra_max) {
1417 /* Refill the readahead buffer */
1418 ra_ptr = 0;
1419 if (block < start)
1420 ra_max = start - block;
1421 else
1422 ra_max = nblocks - block;
1423 ra_max = min(ra_max, ARRAY_SIZE(bh_use));
1424 retval = ext4_bread_batch(dir, block, ra_max,
1425 false /* wait */, bh_use);
1426 if (retval) {
1427 ret = ERR_PTR(retval);
1428 ra_max = 0;
1429 goto cleanup_and_exit;
1430 }
1431 }
1432 if ((bh = bh_use[ra_ptr++]) == NULL)
1433 goto next;
1434 wait_on_buffer(bh);
1435 if (!buffer_uptodate(bh)) {
1436 EXT4_ERROR_INODE(dir, "reading directory lblock %lu",
1437 (unsigned long) block);
1438 brelse(bh);
1439 ret = ERR_PTR(-EIO);
1440 goto cleanup_and_exit;
1441 }
1442 if (!buffer_verified(bh) &&
1443 !is_dx_internal_node(dir, block,
1444 (struct ext4_dir_entry *)bh->b_data) &&
1445 !ext4_dirent_csum_verify(dir,
1446 (struct ext4_dir_entry *)bh->b_data)) {
1447 EXT4_ERROR_INODE(dir, "checksumming directory "
1448 "block %lu", (unsigned long)block);
1449 brelse(bh);
1450 ret = ERR_PTR(-EFSBADCRC);
1451 goto cleanup_and_exit;
1452 }
1453 set_buffer_verified(bh);
1454 i = search_dirblock(bh, dir, &fname,
1455 block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
1456 if (i == 1) {
1457 EXT4_I(dir)->i_dir_start_lookup = block;
1458 ret = bh;
1459 goto cleanup_and_exit;
1460 } else {
1461 brelse(bh);
1462 if (i < 0)
1463 goto cleanup_and_exit;
1464 }
1465 next:
1466 if (++block >= nblocks)
1467 block = 0;
1468 } while (block != start);
1469
1470 /*
1471 * If the directory has grown while we were searching, then
1472 * search the last part of the directory before giving up.
1473 */
1474 block = nblocks;
1475 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1476 if (block < nblocks) {
1477 start = 0;
1478 goto restart;
1479 }
1480
1481 cleanup_and_exit:
1482 /* Clean up the read-ahead blocks */
1483 for (; ra_ptr < ra_max; ra_ptr++)
1484 brelse(bh_use[ra_ptr]);
1485 ext4_fname_free_filename(&fname);
1486 return ret;
1487 }
1488
1489 static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
1490 struct ext4_filename *fname,
1491 struct ext4_dir_entry_2 **res_dir)
1492 {
1493 struct super_block * sb = dir->i_sb;
1494 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
1495 struct buffer_head *bh;
1496 ext4_lblk_t block;
1497 int retval;
1498
1499 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1500 *res_dir = NULL;
1501 #endif
1502 frame = dx_probe(fname, dir, NULL, frames);
1503 if (IS_ERR(frame))
1504 return (struct buffer_head *) frame;
1505 do {
1506 block = dx_get_block(frame->at);
1507 bh = ext4_read_dirblock(dir, block, DIRENT);
1508 if (IS_ERR(bh))
1509 goto errout;
1510
1511 retval = search_dirblock(bh, dir, fname,
1512 block << EXT4_BLOCK_SIZE_BITS(sb),
1513 res_dir);
1514 if (retval == 1)
1515 goto success;
1516 brelse(bh);
1517 if (retval == -1) {
1518 bh = ERR_PTR(ERR_BAD_DX_DIR);
1519 goto errout;
1520 }
1521
1522 /* Check to see if we should continue to search */
1523 retval = ext4_htree_next_block(dir, fname->hinfo.hash, frame,
1524 frames, NULL);
1525 if (retval < 0) {
1526 ext4_warning_inode(dir,
1527 "error %d reading directory index block",
1528 retval);
1529 bh = ERR_PTR(retval);
1530 goto errout;
1531 }
1532 } while (retval == 1);
1533
1534 bh = NULL;
1535 errout:
1536 dxtrace(printk(KERN_DEBUG "%s not found\n", fname->usr_fname->name));
1537 success:
1538 dx_release(frames);
1539 return bh;
1540 }
1541
1542 static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
1543 {
1544 struct inode *inode;
1545 struct ext4_dir_entry_2 *de;
1546 struct buffer_head *bh;
1547 int err;
1548
1549 err = fscrypt_prepare_lookup(dir, dentry, flags);
1550 if (err)
1551 return ERR_PTR(err);
1552
1553 if (dentry->d_name.len > EXT4_NAME_LEN)
1554 return ERR_PTR(-ENAMETOOLONG);
1555
1556 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
1557 if (IS_ERR(bh))
1558 return (struct dentry *) bh;
1559 inode = NULL;
1560 if (bh) {
1561 __u32 ino = le32_to_cpu(de->inode);
1562 brelse(bh);
1563 if (!ext4_valid_inum(dir->i_sb, ino)) {
1564 EXT4_ERROR_INODE(dir, "bad inode number: %u", ino);
1565 return ERR_PTR(-EFSCORRUPTED);
1566 }
1567 if (unlikely(ino == dir->i_ino)) {
1568 EXT4_ERROR_INODE(dir, "'%pd' linked to parent dir",
1569 dentry);
1570 return ERR_PTR(-EFSCORRUPTED);
1571 }
1572 inode = ext4_iget_normal(dir->i_sb, ino);
1573 if (inode == ERR_PTR(-ESTALE)) {
1574 EXT4_ERROR_INODE(dir,
1575 "deleted inode referenced: %u",
1576 ino);
1577 return ERR_PTR(-EFSCORRUPTED);
1578 }
1579 if (!IS_ERR(inode) && ext4_encrypted_inode(dir) &&
1580 (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) &&
1581 !fscrypt_has_permitted_context(dir, inode)) {
1582 ext4_warning(inode->i_sb,
1583 "Inconsistent encryption contexts: %lu/%lu",
1584 dir->i_ino, inode->i_ino);
1585 iput(inode);
1586 return ERR_PTR(-EPERM);
1587 }
1588 }
1589 return d_splice_alias(inode, dentry);
1590 }
1591
1592
1593 struct dentry *ext4_get_parent(struct dentry *child)
1594 {
1595 __u32 ino;
1596 static const struct qstr dotdot = QSTR_INIT("..", 2);
1597 struct ext4_dir_entry_2 * de;
1598 struct buffer_head *bh;
1599
1600 bh = ext4_find_entry(d_inode(child), &dotdot, &de, NULL);
1601 if (IS_ERR(bh))
1602 return (struct dentry *) bh;
1603 if (!bh)
1604 return ERR_PTR(-ENOENT);
1605 ino = le32_to_cpu(de->inode);
1606 brelse(bh);
1607
1608 if (!ext4_valid_inum(child->d_sb, ino)) {
1609 EXT4_ERROR_INODE(d_inode(child),
1610 "bad parent inode number: %u", ino);
1611 return ERR_PTR(-EFSCORRUPTED);
1612 }
1613
1614 return d_obtain_alias(ext4_iget_normal(child->d_sb, ino));
1615 }
1616
1617 /*
1618 * Move count entries from end of map between two memory locations.
1619 * Returns pointer to last entry moved.
1620 */
1621 static struct ext4_dir_entry_2 *
1622 dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count,
1623 unsigned blocksize)
1624 {
1625 unsigned rec_len = 0;
1626
1627 while (count--) {
1628 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
1629 (from + (map->offs<<2));
1630 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1631 memcpy (to, de, rec_len);
1632 ((struct ext4_dir_entry_2 *) to)->rec_len =
1633 ext4_rec_len_to_disk(rec_len, blocksize);
1634 de->inode = 0;
1635 map++;
1636 to += rec_len;
1637 }
1638 return (struct ext4_dir_entry_2 *) (to - rec_len);
1639 }
1640
1641 /*
1642 * Compact each dir entry in the range to the minimal rec_len.
1643 * Returns pointer to last entry in range.
1644 */
1645 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize)
1646 {
1647 struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
1648 unsigned rec_len = 0;
1649
1650 prev = to = de;
1651 while ((char*)de < base + blocksize) {
1652 next = ext4_next_entry(de, blocksize);
1653 if (de->inode && de->name_len) {
1654 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1655 if (de > to)
1656 memmove(to, de, rec_len);
1657 to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
1658 prev = to;
1659 to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
1660 }
1661 de = next;
1662 }
1663 return prev;
1664 }
1665
1666 /*
1667 * Split a full leaf block to make room for a new dir entry.
1668 * Allocate a new block, and move entries so that they are approx. equally full.
1669 * Returns pointer to de in block into which the new entry will be inserted.
1670 */
1671 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
1672 struct buffer_head **bh,struct dx_frame *frame,
1673 struct dx_hash_info *hinfo)
1674 {
1675 unsigned blocksize = dir->i_sb->s_blocksize;
1676 unsigned count, continued;
1677 struct buffer_head *bh2;
1678 ext4_lblk_t newblock;
1679 u32 hash2;
1680 struct dx_map_entry *map;
1681 char *data1 = (*bh)->b_data, *data2;
1682 unsigned split, move, size;
1683 struct ext4_dir_entry_2 *de = NULL, *de2;
1684 struct ext4_dir_entry_tail *t;
1685 int csum_size = 0;
1686 int err = 0, i;
1687
1688 if (ext4_has_metadata_csum(dir->i_sb))
1689 csum_size = sizeof(struct ext4_dir_entry_tail);
1690
1691 bh2 = ext4_append(handle, dir, &newblock);
1692 if (IS_ERR(bh2)) {
1693 brelse(*bh);
1694 *bh = NULL;
1695 return (struct ext4_dir_entry_2 *) bh2;
1696 }
1697
1698 BUFFER_TRACE(*bh, "get_write_access");
1699 err = ext4_journal_get_write_access(handle, *bh);
1700 if (err)
1701 goto journal_error;
1702
1703 BUFFER_TRACE(frame->bh, "get_write_access");
1704 err = ext4_journal_get_write_access(handle, frame->bh);
1705 if (err)
1706 goto journal_error;
1707
1708 data2 = bh2->b_data;
1709
1710 /* create map in the end of data2 block */
1711 map = (struct dx_map_entry *) (data2 + blocksize);
1712 count = dx_make_map(dir, (struct ext4_dir_entry_2 *) data1,
1713 blocksize, hinfo, map);
1714 map -= count;
1715 dx_sort_map(map, count);
1716 /* Split the existing block in the middle, size-wise */
1717 size = 0;
1718 move = 0;
1719 for (i = count-1; i >= 0; i--) {
1720 /* is more than half of this entry in 2nd half of the block? */
1721 if (size + map[i].size/2 > blocksize/2)
1722 break;
1723 size += map[i].size;
1724 move++;
1725 }
1726 /* map index at which we will split */
1727 split = count - move;
1728 hash2 = map[split].hash;
1729 continued = hash2 == map[split - 1].hash;
1730 dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
1731 (unsigned long)dx_get_block(frame->at),
1732 hash2, split, count-split));
1733
1734 /* Fancy dance to stay within two buffers */
1735 de2 = dx_move_dirents(data1, data2, map + split, count - split,
1736 blocksize);
1737 de = dx_pack_dirents(data1, blocksize);
1738 de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
1739 (char *) de,
1740 blocksize);
1741 de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
1742 (char *) de2,
1743 blocksize);
1744 if (csum_size) {
1745 t = EXT4_DIRENT_TAIL(data2, blocksize);
1746 initialize_dirent_tail(t, blocksize);
1747
1748 t = EXT4_DIRENT_TAIL(data1, blocksize);
1749 initialize_dirent_tail(t, blocksize);
1750 }
1751
1752 dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data1,
1753 blocksize, 1));
1754 dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data2,
1755 blocksize, 1));
1756
1757 /* Which block gets the new entry? */
1758 if (hinfo->hash >= hash2) {
1759 swap(*bh, bh2);
1760 de = de2;
1761 }
1762 dx_insert_block(frame, hash2 + continued, newblock);
1763 err = ext4_handle_dirty_dirent_node(handle, dir, bh2);
1764 if (err)
1765 goto journal_error;
1766 err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
1767 if (err)
1768 goto journal_error;
1769 brelse(bh2);
1770 dxtrace(dx_show_index("frame", frame->entries));
1771 return de;
1772
1773 journal_error:
1774 brelse(*bh);
1775 brelse(bh2);
1776 *bh = NULL;
1777 ext4_std_error(dir->i_sb, err);
1778 return ERR_PTR(err);
1779 }
1780
1781 int ext4_find_dest_de(struct inode *dir, struct inode *inode,
1782 struct buffer_head *bh,
1783 void *buf, int buf_size,
1784 struct ext4_filename *fname,
1785 struct ext4_dir_entry_2 **dest_de)
1786 {
1787 struct ext4_dir_entry_2 *de;
1788 unsigned short reclen = EXT4_DIR_REC_LEN(fname_len(fname));
1789 int nlen, rlen;
1790 unsigned int offset = 0;
1791 char *top;
1792
1793 de = (struct ext4_dir_entry_2 *)buf;
1794 top = buf + buf_size - reclen;
1795 while ((char *) de <= top) {
1796 if (ext4_check_dir_entry(dir, NULL, de, bh,
1797 buf, buf_size, offset))
1798 return -EFSCORRUPTED;
1799 if (ext4_match(fname, de))
1800 return -EEXIST;
1801 nlen = EXT4_DIR_REC_LEN(de->name_len);
1802 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
1803 if ((de->inode ? rlen - nlen : rlen) >= reclen)
1804 break;
1805 de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
1806 offset += rlen;
1807 }
1808 if ((char *) de > top)
1809 return -ENOSPC;
1810
1811 *dest_de = de;
1812 return 0;
1813 }
1814
1815 void ext4_insert_dentry(struct inode *inode,
1816 struct ext4_dir_entry_2 *de,
1817 int buf_size,
1818 struct ext4_filename *fname)
1819 {
1820
1821 int nlen, rlen;
1822
1823 nlen = EXT4_DIR_REC_LEN(de->name_len);
1824 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
1825 if (de->inode) {
1826 struct ext4_dir_entry_2 *de1 =
1827 (struct ext4_dir_entry_2 *)((char *)de + nlen);
1828 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, buf_size);
1829 de->rec_len = ext4_rec_len_to_disk(nlen, buf_size);
1830 de = de1;
1831 }
1832 de->file_type = EXT4_FT_UNKNOWN;
1833 de->inode = cpu_to_le32(inode->i_ino);
1834 ext4_set_de_type(inode->i_sb, de, inode->i_mode);
1835 de->name_len = fname_len(fname);
1836 memcpy(de->name, fname_name(fname), fname_len(fname));
1837 }
1838
1839 /*
1840 * Add a new entry into a directory (leaf) block. If de is non-NULL,
1841 * it points to a directory entry which is guaranteed to be large
1842 * enough for new directory entry. If de is NULL, then
1843 * add_dirent_to_buf will attempt search the directory block for
1844 * space. It will return -ENOSPC if no space is available, and -EIO
1845 * and -EEXIST if directory entry already exists.
1846 */
1847 static int add_dirent_to_buf(handle_t *handle, struct ext4_filename *fname,
1848 struct inode *dir,
1849 struct inode *inode, struct ext4_dir_entry_2 *de,
1850 struct buffer_head *bh)
1851 {
1852 unsigned int blocksize = dir->i_sb->s_blocksize;
1853 int csum_size = 0;
1854 int err;
1855
1856 if (ext4_has_metadata_csum(inode->i_sb))
1857 csum_size = sizeof(struct ext4_dir_entry_tail);
1858
1859 if (!de) {
1860 err = ext4_find_dest_de(dir, inode, bh, bh->b_data,
1861 blocksize - csum_size, fname, &de);
1862 if (err)
1863 return err;
1864 }
1865 BUFFER_TRACE(bh, "get_write_access");
1866 err = ext4_journal_get_write_access(handle, bh);
1867 if (err) {
1868 ext4_std_error(dir->i_sb, err);
1869 return err;
1870 }
1871
1872 /* By now the buffer is marked for journaling */
1873 ext4_insert_dentry(inode, de, blocksize, fname);
1874
1875 /*
1876 * XXX shouldn't update any times until successful
1877 * completion of syscall, but too many callers depend
1878 * on this.
1879 *
1880 * XXX similarly, too many callers depend on
1881 * ext4_new_inode() setting the times, but error
1882 * recovery deletes the inode, so the worst that can
1883 * happen is that the times are slightly out of date
1884 * and/or different from the directory change time.
1885 */
1886 dir->i_mtime = dir->i_ctime = current_time(dir);
1887 ext4_update_dx_flag(dir);
1888 inode_inc_iversion(dir);
1889 ext4_mark_inode_dirty(handle, dir);
1890 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1891 err = ext4_handle_dirty_dirent_node(handle, dir, bh);
1892 if (err)
1893 ext4_std_error(dir->i_sb, err);
1894 return 0;
1895 }
1896
1897 /*
1898 * This converts a one block unindexed directory to a 3 block indexed
1899 * directory, and adds the dentry to the indexed directory.
1900 */
1901 static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname,
1902 struct inode *dir,
1903 struct inode *inode, struct buffer_head *bh)
1904 {
1905 struct buffer_head *bh2;
1906 struct dx_root *root;
1907 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
1908 struct dx_entry *entries;
1909 struct ext4_dir_entry_2 *de, *de2;
1910 struct ext4_dir_entry_tail *t;
1911 char *data1, *top;
1912 unsigned len;
1913 int retval;
1914 unsigned blocksize;
1915 ext4_lblk_t block;
1916 struct fake_dirent *fde;
1917 int csum_size = 0;
1918
1919 if (ext4_has_metadata_csum(inode->i_sb))
1920 csum_size = sizeof(struct ext4_dir_entry_tail);
1921
1922 blocksize = dir->i_sb->s_blocksize;
1923 dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
1924 BUFFER_TRACE(bh, "get_write_access");
1925 retval = ext4_journal_get_write_access(handle, bh);
1926 if (retval) {
1927 ext4_std_error(dir->i_sb, retval);
1928 brelse(bh);
1929 return retval;
1930 }
1931 root = (struct dx_root *) bh->b_data;
1932
1933 /* The 0th block becomes the root, move the dirents out */
1934 fde = &root->dotdot;
1935 de = (struct ext4_dir_entry_2 *)((char *)fde +
1936 ext4_rec_len_from_disk(fde->rec_len, blocksize));
1937 if ((char *) de >= (((char *) root) + blocksize)) {
1938 EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
1939 brelse(bh);
1940 return -EFSCORRUPTED;
1941 }
1942 len = ((char *) root) + (blocksize - csum_size) - (char *) de;
1943
1944 /* Allocate new block for the 0th block's dirents */
1945 bh2 = ext4_append(handle, dir, &block);
1946 if (IS_ERR(bh2)) {
1947 brelse(bh);
1948 return PTR_ERR(bh2);
1949 }
1950 ext4_set_inode_flag(dir, EXT4_INODE_INDEX);
1951 data1 = bh2->b_data;
1952
1953 memcpy (data1, de, len);
1954 de = (struct ext4_dir_entry_2 *) data1;
1955 top = data1 + len;
1956 while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
1957 de = de2;
1958 de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
1959 (char *) de,
1960 blocksize);
1961
1962 if (csum_size) {
1963 t = EXT4_DIRENT_TAIL(data1, blocksize);
1964 initialize_dirent_tail(t, blocksize);
1965 }
1966
1967 /* Initialize the root; the dot dirents already exist */
1968 de = (struct ext4_dir_entry_2 *) (&root->dotdot);
1969 de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
1970 blocksize);
1971 memset (&root->info, 0, sizeof(root->info));
1972 root->info.info_length = sizeof(root->info);
1973 root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
1974 entries = root->entries;
1975 dx_set_block(entries, 1);
1976 dx_set_count(entries, 1);
1977 dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
1978
1979 /* Initialize as for dx_probe */
1980 fname->hinfo.hash_version = root->info.hash_version;
1981 if (fname->hinfo.hash_version <= DX_HASH_TEA)
1982 fname->hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
1983 fname->hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
1984 ext4fs_dirhash(fname_name(fname), fname_len(fname), &fname->hinfo);
1985
1986 memset(frames, 0, sizeof(frames));
1987 frame = frames;
1988 frame->entries = entries;
1989 frame->at = entries;
1990 frame->bh = bh;
1991
1992 retval = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
1993 if (retval)
1994 goto out_frames;
1995 retval = ext4_handle_dirty_dirent_node(handle, dir, bh2);
1996 if (retval)
1997 goto out_frames;
1998
1999 de = do_split(handle,dir, &bh2, frame, &fname->hinfo);
2000 if (IS_ERR(de)) {
2001 retval = PTR_ERR(de);
2002 goto out_frames;
2003 }
2004
2005 retval = add_dirent_to_buf(handle, fname, dir, inode, de, bh2);
2006 out_frames:
2007 /*
2008 * Even if the block split failed, we have to properly write
2009 * out all the changes we did so far. Otherwise we can end up
2010 * with corrupted filesystem.
2011 */
2012 if (retval)
2013 ext4_mark_inode_dirty(handle, dir);
2014 dx_release(frames);
2015 brelse(bh2);
2016 return retval;
2017 }
2018
2019 /*
2020 * ext4_add_entry()
2021 *
2022 * adds a file entry to the specified directory, using the same
2023 * semantics as ext4_find_entry(). It returns NULL if it failed.
2024 *
2025 * NOTE!! The inode part of 'de' is left at 0 - which means you
2026 * may not sleep between calling this and putting something into
2027 * the entry, as someone else might have used it while you slept.
2028 */
2029 static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
2030 struct inode *inode)
2031 {
2032 struct inode *dir = d_inode(dentry->d_parent);
2033 struct buffer_head *bh = NULL;
2034 struct ext4_dir_entry_2 *de;
2035 struct ext4_dir_entry_tail *t;
2036 struct super_block *sb;
2037 struct ext4_filename fname;
2038 int retval;
2039 int dx_fallback=0;
2040 unsigned blocksize;
2041 ext4_lblk_t block, blocks;
2042 int csum_size = 0;
2043
2044 if (ext4_has_metadata_csum(inode->i_sb))
2045 csum_size = sizeof(struct ext4_dir_entry_tail);
2046
2047 sb = dir->i_sb;
2048 blocksize = sb->s_blocksize;
2049 if (!dentry->d_name.len)
2050 return -EINVAL;
2051
2052 retval = ext4_fname_setup_filename(dir, &dentry->d_name, 0, &fname);
2053 if (retval)
2054 return retval;
2055
2056 if (ext4_has_inline_data(dir)) {
2057 retval = ext4_try_add_inline_entry(handle, &fname, dir, inode);
2058 if (retval < 0)
2059 goto out;
2060 if (retval == 1) {
2061 retval = 0;
2062 goto out;
2063 }
2064 }
2065
2066 if (is_dx(dir)) {
2067 retval = ext4_dx_add_entry(handle, &fname, dir, inode);
2068 if (!retval || (retval != ERR_BAD_DX_DIR))
2069 goto out;
2070 ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
2071 dx_fallback++;
2072 ext4_mark_inode_dirty(handle, dir);
2073 }
2074 blocks = dir->i_size >> sb->s_blocksize_bits;
2075 for (block = 0; block < blocks; block++) {
2076 bh = ext4_read_dirblock(dir, block, DIRENT);
2077 if (IS_ERR(bh)) {
2078 retval = PTR_ERR(bh);
2079 bh = NULL;
2080 goto out;
2081 }
2082 retval = add_dirent_to_buf(handle, &fname, dir, inode,
2083 NULL, bh);
2084 if (retval != -ENOSPC)
2085 goto out;
2086
2087 if (blocks == 1 && !dx_fallback &&
2088 ext4_has_feature_dir_index(sb)) {
2089 retval = make_indexed_dir(handle, &fname, dir,
2090 inode, bh);
2091 bh = NULL; /* make_indexed_dir releases bh */
2092 goto out;
2093 }
2094 brelse(bh);
2095 }
2096 bh = ext4_append(handle, dir, &block);
2097 if (IS_ERR(bh)) {
2098 retval = PTR_ERR(bh);
2099 bh = NULL;
2100 goto out;
2101 }
2102 de = (struct ext4_dir_entry_2 *) bh->b_data;
2103 de->inode = 0;
2104 de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize);
2105
2106 if (csum_size) {
2107 t = EXT4_DIRENT_TAIL(bh->b_data, blocksize);
2108 initialize_dirent_tail(t, blocksize);
2109 }
2110
2111 retval = add_dirent_to_buf(handle, &fname, dir, inode, de, bh);
2112 out:
2113 ext4_fname_free_filename(&fname);
2114 brelse(bh);
2115 if (retval == 0)
2116 ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY);
2117 return retval;
2118 }
2119
2120 /*
2121 * Returns 0 for success, or a negative error value
2122 */
2123 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
2124 struct inode *dir, struct inode *inode)
2125 {
2126 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
2127 struct dx_entry *entries, *at;
2128 struct buffer_head *bh;
2129 struct super_block *sb = dir->i_sb;
2130 struct ext4_dir_entry_2 *de;
2131 int restart;
2132 int err;
2133
2134 again:
2135 restart = 0;
2136 frame = dx_probe(fname, dir, NULL, frames);
2137 if (IS_ERR(frame))
2138 return PTR_ERR(frame);
2139 entries = frame->entries;
2140 at = frame->at;
2141 bh = ext4_read_dirblock(dir, dx_get_block(frame->at), DIRENT);
2142 if (IS_ERR(bh)) {
2143 err = PTR_ERR(bh);
2144 bh = NULL;
2145 goto cleanup;
2146 }
2147
2148 BUFFER_TRACE(bh, "get_write_access");
2149 err = ext4_journal_get_write_access(handle, bh);
2150 if (err)
2151 goto journal_error;
2152
2153 err = add_dirent_to_buf(handle, fname, dir, inode, NULL, bh);
2154 if (err != -ENOSPC)
2155 goto cleanup;
2156
2157 err = 0;
2158 /* Block full, should compress but for now just split */
2159 dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
2160 dx_get_count(entries), dx_get_limit(entries)));
2161 /* Need to split index? */
2162 if (dx_get_count(entries) == dx_get_limit(entries)) {
2163 ext4_lblk_t newblock;
2164 int levels = frame - frames + 1;
2165 unsigned int icount;
2166 int add_level = 1;
2167 struct dx_entry *entries2;
2168 struct dx_node *node2;
2169 struct buffer_head *bh2;
2170
2171 while (frame > frames) {
2172 if (dx_get_count((frame - 1)->entries) <
2173 dx_get_limit((frame - 1)->entries)) {
2174 add_level = 0;
2175 break;
2176 }
2177 frame--; /* split higher index block */
2178 at = frame->at;
2179 entries = frame->entries;
2180 restart = 1;
2181 }
2182 if (add_level && levels == ext4_dir_htree_level(sb)) {
2183 ext4_warning(sb, "Directory (ino: %lu) index full, "
2184 "reach max htree level :%d",
2185 dir->i_ino, levels);
2186 if (ext4_dir_htree_level(sb) < EXT4_HTREE_LEVEL) {
2187 ext4_warning(sb, "Large directory feature is "
2188 "not enabled on this "
2189 "filesystem");
2190 }
2191 err = -ENOSPC;
2192 goto cleanup;
2193 }
2194 icount = dx_get_count(entries);
2195 bh2 = ext4_append(handle, dir, &newblock);
2196 if (IS_ERR(bh2)) {
2197 err = PTR_ERR(bh2);
2198 goto cleanup;
2199 }
2200 node2 = (struct dx_node *)(bh2->b_data);
2201 entries2 = node2->entries;
2202 memset(&node2->fake, 0, sizeof(struct fake_dirent));
2203 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
2204 sb->s_blocksize);
2205 BUFFER_TRACE(frame->bh, "get_write_access");
2206 err = ext4_journal_get_write_access(handle, frame->bh);
2207 if (err)
2208 goto journal_error;
2209 if (!add_level) {
2210 unsigned icount1 = icount/2, icount2 = icount - icount1;
2211 unsigned hash2 = dx_get_hash(entries + icount1);
2212 dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
2213 icount1, icount2));
2214
2215 BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
2216 err = ext4_journal_get_write_access(handle,
2217 (frame - 1)->bh);
2218 if (err)
2219 goto journal_error;
2220
2221 memcpy((char *) entries2, (char *) (entries + icount1),
2222 icount2 * sizeof(struct dx_entry));
2223 dx_set_count(entries, icount1);
2224 dx_set_count(entries2, icount2);
2225 dx_set_limit(entries2, dx_node_limit(dir));
2226
2227 /* Which index block gets the new entry? */
2228 if (at - entries >= icount1) {
2229 frame->at = at = at - entries - icount1 + entries2;
2230 frame->entries = entries = entries2;
2231 swap(frame->bh, bh2);
2232 }
2233 dx_insert_block((frame - 1), hash2, newblock);
2234 dxtrace(dx_show_index("node", frame->entries));
2235 dxtrace(dx_show_index("node",
2236 ((struct dx_node *) bh2->b_data)->entries));
2237 err = ext4_handle_dirty_dx_node(handle, dir, bh2);
2238 if (err)
2239 goto journal_error;
2240 brelse (bh2);
2241 err = ext4_handle_dirty_dx_node(handle, dir,
2242 (frame - 1)->bh);
2243 if (err)
2244 goto journal_error;
2245 if (restart) {
2246 err = ext4_handle_dirty_dx_node(handle, dir,
2247 frame->bh);
2248 goto journal_error;
2249 }
2250 } else {
2251 struct dx_root *dxroot;
2252 memcpy((char *) entries2, (char *) entries,
2253 icount * sizeof(struct dx_entry));
2254 dx_set_limit(entries2, dx_node_limit(dir));
2255
2256 /* Set up root */
2257 dx_set_count(entries, 1);
2258 dx_set_block(entries + 0, newblock);
2259 dxroot = (struct dx_root *)frames[0].bh->b_data;
2260 dxroot->info.indirect_levels += 1;
2261 dxtrace(printk(KERN_DEBUG
2262 "Creating %d level index...\n",
2263 info->indirect_levels));
2264 err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
2265 if (err)
2266 goto journal_error;
2267 err = ext4_handle_dirty_dx_node(handle, dir, bh2);
2268 brelse(bh2);
2269 restart = 1;
2270 goto journal_error;
2271 }
2272 }
2273 de = do_split(handle, dir, &bh, frame, &fname->hinfo);
2274 if (IS_ERR(de)) {
2275 err = PTR_ERR(de);
2276 goto cleanup;
2277 }
2278 err = add_dirent_to_buf(handle, fname, dir, inode, de, bh);
2279 goto cleanup;
2280
2281 journal_error:
2282 ext4_std_error(dir->i_sb, err); /* this is a no-op if err == 0 */
2283 cleanup:
2284 brelse(bh);
2285 dx_release(frames);
2286 /* @restart is true means htree-path has been changed, we need to
2287 * repeat dx_probe() to find out valid htree-path
2288 */
2289 if (restart && err == 0)
2290 goto again;
2291 return err;
2292 }
2293
2294 /*
2295 * ext4_generic_delete_entry deletes a directory entry by merging it
2296 * with the previous entry
2297 */
2298 int ext4_generic_delete_entry(handle_t *handle,
2299 struct inode *dir,
2300 struct ext4_dir_entry_2 *de_del,
2301 struct buffer_head *bh,
2302 void *entry_buf,
2303 int buf_size,
2304 int csum_size)
2305 {
2306 struct ext4_dir_entry_2 *de, *pde;
2307 unsigned int blocksize = dir->i_sb->s_blocksize;
2308 int i;
2309
2310 i = 0;
2311 pde = NULL;
2312 de = (struct ext4_dir_entry_2 *)entry_buf;
2313 while (i < buf_size - csum_size) {
2314 if (ext4_check_dir_entry(dir, NULL, de, bh,
2315 bh->b_data, bh->b_size, i))
2316 return -EFSCORRUPTED;
2317 if (de == de_del) {
2318 if (pde)
2319 pde->rec_len = ext4_rec_len_to_disk(
2320 ext4_rec_len_from_disk(pde->rec_len,
2321 blocksize) +
2322 ext4_rec_len_from_disk(de->rec_len,
2323 blocksize),
2324 blocksize);
2325 else
2326 de->inode = 0;
2327 inode_inc_iversion(dir);
2328 return 0;
2329 }
2330 i += ext4_rec_len_from_disk(de->rec_len, blocksize);
2331 pde = de;
2332 de = ext4_next_entry(de, blocksize);
2333 }
2334 return -ENOENT;
2335 }
2336
2337 static int ext4_delete_entry(handle_t *handle,
2338 struct inode *dir,
2339 struct ext4_dir_entry_2 *de_del,
2340 struct buffer_head *bh)
2341 {
2342 int err, csum_size = 0;
2343
2344 if (ext4_has_inline_data(dir)) {
2345 int has_inline_data = 1;
2346 err = ext4_delete_inline_entry(handle, dir, de_del, bh,
2347 &has_inline_data);
2348 if (has_inline_data)
2349 return err;
2350 }
2351
2352 if (ext4_has_metadata_csum(dir->i_sb))
2353 csum_size = sizeof(struct ext4_dir_entry_tail);
2354
2355 BUFFER_TRACE(bh, "get_write_access");
2356 err = ext4_journal_get_write_access(handle, bh);
2357 if (unlikely(err))
2358 goto out;
2359
2360 err = ext4_generic_delete_entry(handle, dir, de_del,
2361 bh, bh->b_data,
2362 dir->i_sb->s_blocksize, csum_size);
2363 if (err)
2364 goto out;
2365
2366 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
2367 err = ext4_handle_dirty_dirent_node(handle, dir, bh);
2368 if (unlikely(err))
2369 goto out;
2370
2371 return 0;
2372 out:
2373 if (err != -ENOENT)
2374 ext4_std_error(dir->i_sb, err);
2375 return err;
2376 }
2377
2378 /*
2379 * Set directory link count to 1 if nlinks > EXT4_LINK_MAX, or if nlinks == 2
2380 * since this indicates that nlinks count was previously 1 to avoid overflowing
2381 * the 16-bit i_links_count field on disk. Directories with i_nlink == 1 mean
2382 * that subdirectory link counts are not being maintained accurately.
2383 *
2384 * The caller has already checked for i_nlink overflow in case the DIR_LINK
2385 * feature is not enabled and returned -EMLINK. The is_dx() check is a proxy
2386 * for checking S_ISDIR(inode) (since the INODE_INDEX feature will not be set
2387 * on regular files) and to avoid creating huge/slow non-HTREE directories.
2388 */
2389 static void ext4_inc_count(handle_t *handle, struct inode *inode)
2390 {
2391 inc_nlink(inode);
2392 if (is_dx(inode) &&
2393 (inode->i_nlink > EXT4_LINK_MAX || inode->i_nlink == 2))
2394 set_nlink(inode, 1);
2395 }
2396
2397 /*
2398 * If a directory had nlink == 1, then we should let it be 1. This indicates
2399 * directory has >EXT4_LINK_MAX subdirs.
2400 */
2401 static void ext4_dec_count(handle_t *handle, struct inode *inode)
2402 {
2403 if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
2404 drop_nlink(inode);
2405 }
2406
2407
2408 static int ext4_add_nondir(handle_t *handle,
2409 struct dentry *dentry, struct inode *inode)
2410 {
2411 int err = ext4_add_entry(handle, dentry, inode);
2412 if (!err) {
2413 ext4_mark_inode_dirty(handle, inode);
2414 unlock_new_inode(inode);
2415 d_instantiate(dentry, inode);
2416 return 0;
2417 }
2418 drop_nlink(inode);
2419 unlock_new_inode(inode);
2420 iput(inode);
2421 return err;
2422 }
2423
2424 /*
2425 * By the time this is called, we already have created
2426 * the directory cache entry for the new file, but it
2427 * is so far negative - it has no inode.
2428 *
2429 * If the create succeeds, we fill in the inode information
2430 * with d_instantiate().
2431 */
2432 static int ext4_create(struct inode *dir, struct dentry *dentry, umode_t mode,
2433 bool excl)
2434 {
2435 handle_t *handle;
2436 struct inode *inode;
2437 int err, credits, retries = 0;
2438
2439 err = dquot_initialize(dir);
2440 if (err)
2441 return err;
2442
2443 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2444 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2445 retry:
2446 inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
2447 NULL, EXT4_HT_DIR, credits);
2448 handle = ext4_journal_current_handle();
2449 err = PTR_ERR(inode);
2450 if (!IS_ERR(inode)) {
2451 inode->i_op = &ext4_file_inode_operations;
2452 inode->i_fop = &ext4_file_operations;
2453 ext4_set_aops(inode);
2454 err = ext4_add_nondir(handle, dentry, inode);
2455 if (!err && IS_DIRSYNC(dir))
2456 ext4_handle_sync(handle);
2457 }
2458 if (handle)
2459 ext4_journal_stop(handle);
2460 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2461 goto retry;
2462 return err;
2463 }
2464
2465 static int ext4_mknod(struct inode *dir, struct dentry *dentry,
2466 umode_t mode, dev_t rdev)
2467 {
2468 handle_t *handle;
2469 struct inode *inode;
2470 int err, credits, retries = 0;
2471
2472 err = dquot_initialize(dir);
2473 if (err)
2474 return err;
2475
2476 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2477 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2478 retry:
2479 inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
2480 NULL, EXT4_HT_DIR, credits);
2481 handle = ext4_journal_current_handle();
2482 err = PTR_ERR(inode);
2483 if (!IS_ERR(inode)) {
2484 init_special_inode(inode, inode->i_mode, rdev);
2485 inode->i_op = &ext4_special_inode_operations;
2486 err = ext4_add_nondir(handle, dentry, inode);
2487 if (!err && IS_DIRSYNC(dir))
2488 ext4_handle_sync(handle);
2489 }
2490 if (handle)
2491 ext4_journal_stop(handle);
2492 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2493 goto retry;
2494 return err;
2495 }
2496
2497 static int ext4_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
2498 {
2499 handle_t *handle;
2500 struct inode *inode;
2501 int err, retries = 0;
2502
2503 err = dquot_initialize(dir);
2504 if (err)
2505 return err;
2506
2507 retry:
2508 inode = ext4_new_inode_start_handle(dir, mode,
2509 NULL, 0, NULL,
2510 EXT4_HT_DIR,
2511 EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
2512 4 + EXT4_XATTR_TRANS_BLOCKS);
2513 handle = ext4_journal_current_handle();
2514 err = PTR_ERR(inode);
2515 if (!IS_ERR(inode)) {
2516 inode->i_op = &ext4_file_inode_operations;
2517 inode->i_fop = &ext4_file_operations;
2518 ext4_set_aops(inode);
2519 d_tmpfile(dentry, inode);
2520 err = ext4_orphan_add(handle, inode);
2521 if (err)
2522 goto err_unlock_inode;
2523 mark_inode_dirty(inode);
2524 unlock_new_inode(inode);
2525 }
2526 if (handle)
2527 ext4_journal_stop(handle);
2528 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2529 goto retry;
2530 return err;
2531 err_unlock_inode:
2532 ext4_journal_stop(handle);
2533 unlock_new_inode(inode);
2534 return err;
2535 }
2536
2537 struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
2538 struct ext4_dir_entry_2 *de,
2539 int blocksize, int csum_size,
2540 unsigned int parent_ino, int dotdot_real_len)
2541 {
2542 de->inode = cpu_to_le32(inode->i_ino);
2543 de->name_len = 1;
2544 de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
2545 blocksize);
2546 strcpy(de->name, ".");
2547 ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2548
2549 de = ext4_next_entry(de, blocksize);
2550 de->inode = cpu_to_le32(parent_ino);
2551 de->name_len = 2;
2552 if (!dotdot_real_len)
2553 de->rec_len = ext4_rec_len_to_disk(blocksize -
2554 (csum_size + EXT4_DIR_REC_LEN(1)),
2555 blocksize);
2556 else
2557 de->rec_len = ext4_rec_len_to_disk(
2558 EXT4_DIR_REC_LEN(de->name_len), blocksize);
2559 strcpy(de->name, "..");
2560 ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2561
2562 return ext4_next_entry(de, blocksize);
2563 }
2564
2565 static int ext4_init_new_dir(handle_t *handle, struct inode *dir,
2566 struct inode *inode)
2567 {
2568 struct buffer_head *dir_block = NULL;
2569 struct ext4_dir_entry_2 *de;
2570 struct ext4_dir_entry_tail *t;
2571 ext4_lblk_t block = 0;
2572 unsigned int blocksize = dir->i_sb->s_blocksize;
2573 int csum_size = 0;
2574 int err;
2575
2576 if (ext4_has_metadata_csum(dir->i_sb))
2577 csum_size = sizeof(struct ext4_dir_entry_tail);
2578
2579 if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
2580 err = ext4_try_create_inline_dir(handle, dir, inode);
2581 if (err < 0 && err != -ENOSPC)
2582 goto out;
2583 if (!err)
2584 goto out;
2585 }
2586
2587 inode->i_size = 0;
2588 dir_block = ext4_append(handle, inode, &block);
2589 if (IS_ERR(dir_block))
2590 return PTR_ERR(dir_block);
2591 de = (struct ext4_dir_entry_2 *)dir_block->b_data;
2592 ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0);
2593 set_nlink(inode, 2);
2594 if (csum_size) {
2595 t = EXT4_DIRENT_TAIL(dir_block->b_data, blocksize);
2596 initialize_dirent_tail(t, blocksize);
2597 }
2598
2599 BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
2600 err = ext4_handle_dirty_dirent_node(handle, inode, dir_block);
2601 if (err)
2602 goto out;
2603 set_buffer_verified(dir_block);
2604 out:
2605 brelse(dir_block);
2606 return err;
2607 }
2608
2609 static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
2610 {
2611 handle_t *handle;
2612 struct inode *inode;
2613 int err, credits, retries = 0;
2614
2615 if (EXT4_DIR_LINK_MAX(dir))
2616 return -EMLINK;
2617
2618 err = dquot_initialize(dir);
2619 if (err)
2620 return err;
2621
2622 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2623 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2624 retry:
2625 inode = ext4_new_inode_start_handle(dir, S_IFDIR | mode,
2626 &dentry->d_name,
2627 0, NULL, EXT4_HT_DIR, credits);
2628 handle = ext4_journal_current_handle();
2629 err = PTR_ERR(inode);
2630 if (IS_ERR(inode))
2631 goto out_stop;
2632
2633 inode->i_op = &ext4_dir_inode_operations;
2634 inode->i_fop = &ext4_dir_operations;
2635 err = ext4_init_new_dir(handle, dir, inode);
2636 if (err)
2637 goto out_clear_inode;
2638 err = ext4_mark_inode_dirty(handle, inode);
2639 if (!err)
2640 err = ext4_add_entry(handle, dentry, inode);
2641 if (err) {
2642 out_clear_inode:
2643 clear_nlink(inode);
2644 unlock_new_inode(inode);
2645 ext4_mark_inode_dirty(handle, inode);
2646 iput(inode);
2647 goto out_stop;
2648 }
2649 ext4_inc_count(handle, dir);
2650 ext4_update_dx_flag(dir);
2651 err = ext4_mark_inode_dirty(handle, dir);
2652 if (err)
2653 goto out_clear_inode;
2654 unlock_new_inode(inode);
2655 d_instantiate(dentry, inode);
2656 if (IS_DIRSYNC(dir))
2657 ext4_handle_sync(handle);
2658
2659 out_stop:
2660 if (handle)
2661 ext4_journal_stop(handle);
2662 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2663 goto retry;
2664 return err;
2665 }
2666
2667 /*
2668 * routine to check that the specified directory is empty (for rmdir)
2669 */
2670 bool ext4_empty_dir(struct inode *inode)
2671 {
2672 unsigned int offset;
2673 struct buffer_head *bh;
2674 struct ext4_dir_entry_2 *de, *de1;
2675 struct super_block *sb;
2676
2677 if (ext4_has_inline_data(inode)) {
2678 int has_inline_data = 1;
2679 int ret;
2680
2681 ret = empty_inline_dir(inode, &has_inline_data);
2682 if (has_inline_data)
2683 return ret;
2684 }
2685
2686 sb = inode->i_sb;
2687 if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2)) {
2688 EXT4_ERROR_INODE(inode, "invalid size");
2689 return true;
2690 }
2691 bh = ext4_read_dirblock(inode, 0, EITHER);
2692 if (IS_ERR(bh))
2693 return true;
2694
2695 de = (struct ext4_dir_entry_2 *) bh->b_data;
2696 de1 = ext4_next_entry(de, sb->s_blocksize);
2697 if (le32_to_cpu(de->inode) != inode->i_ino ||
2698 le32_to_cpu(de1->inode) == 0 ||
2699 strcmp(".", de->name) || strcmp("..", de1->name)) {
2700 ext4_warning_inode(inode, "directory missing '.' and/or '..'");
2701 brelse(bh);
2702 return true;
2703 }
2704 offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) +
2705 ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize);
2706 de = ext4_next_entry(de1, sb->s_blocksize);
2707 while (offset < inode->i_size) {
2708 if ((void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
2709 unsigned int lblock;
2710 brelse(bh);
2711 lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb);
2712 bh = ext4_read_dirblock(inode, lblock, EITHER);
2713 if (IS_ERR(bh))
2714 return true;
2715 de = (struct ext4_dir_entry_2 *) bh->b_data;
2716 }
2717 if (ext4_check_dir_entry(inode, NULL, de, bh,
2718 bh->b_data, bh->b_size, offset)) {
2719 de = (struct ext4_dir_entry_2 *)(bh->b_data +
2720 sb->s_blocksize);
2721 offset = (offset | (sb->s_blocksize - 1)) + 1;
2722 continue;
2723 }
2724 if (le32_to_cpu(de->inode)) {
2725 brelse(bh);
2726 return false;
2727 }
2728 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
2729 de = ext4_next_entry(de, sb->s_blocksize);
2730 }
2731 brelse(bh);
2732 return true;
2733 }
2734
2735 /*
2736 * ext4_orphan_add() links an unlinked or truncated inode into a list of
2737 * such inodes, starting at the superblock, in case we crash before the
2738 * file is closed/deleted, or in case the inode truncate spans multiple
2739 * transactions and the last transaction is not recovered after a crash.
2740 *
2741 * At filesystem recovery time, we walk this list deleting unlinked
2742 * inodes and truncating linked inodes in ext4_orphan_cleanup().
2743 *
2744 * Orphan list manipulation functions must be called under i_mutex unless
2745 * we are just creating the inode or deleting it.
2746 */
2747 int ext4_orphan_add(handle_t *handle, struct inode *inode)
2748 {
2749 struct super_block *sb = inode->i_sb;
2750 struct ext4_sb_info *sbi = EXT4_SB(sb);
2751 struct ext4_iloc iloc;
2752 int err = 0, rc;
2753 bool dirty = false;
2754
2755 if (!sbi->s_journal || is_bad_inode(inode))
2756 return 0;
2757
2758 WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
2759 !inode_is_locked(inode));
2760 /*
2761 * Exit early if inode already is on orphan list. This is a big speedup
2762 * since we don't have to contend on the global s_orphan_lock.
2763 */
2764 if (!list_empty(&EXT4_I(inode)->i_orphan))
2765 return 0;
2766
2767 /*
2768 * Orphan handling is only valid for files with data blocks
2769 * being truncated, or files being unlinked. Note that we either
2770 * hold i_mutex, or the inode can not be referenced from outside,
2771 * so i_nlink should not be bumped due to race
2772 */
2773 J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2774 S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
2775
2776 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2777 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2778 if (err)
2779 goto out;
2780
2781 err = ext4_reserve_inode_write(handle, inode, &iloc);
2782 if (err)
2783 goto out;
2784
2785 mutex_lock(&sbi->s_orphan_lock);
2786 /*
2787 * Due to previous errors inode may be already a part of on-disk
2788 * orphan list. If so skip on-disk list modification.
2789 */
2790 if (!NEXT_ORPHAN(inode) || NEXT_ORPHAN(inode) >
2791 (le32_to_cpu(sbi->s_es->s_inodes_count))) {
2792 /* Insert this inode at the head of the on-disk orphan list */
2793 NEXT_ORPHAN(inode) = le32_to_cpu(sbi->s_es->s_last_orphan);
2794 sbi->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
2795 dirty = true;
2796 }
2797 list_add(&EXT4_I(inode)->i_orphan, &sbi->s_orphan);
2798 mutex_unlock(&sbi->s_orphan_lock);
2799
2800 if (dirty) {
2801 err = ext4_handle_dirty_super(handle, sb);
2802 rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
2803 if (!err)
2804 err = rc;
2805 if (err) {
2806 /*
2807 * We have to remove inode from in-memory list if
2808 * addition to on disk orphan list failed. Stray orphan
2809 * list entries can cause panics at unmount time.
2810 */
2811 mutex_lock(&sbi->s_orphan_lock);
2812 list_del_init(&EXT4_I(inode)->i_orphan);
2813 mutex_unlock(&sbi->s_orphan_lock);
2814 }
2815 }
2816 jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
2817 jbd_debug(4, "orphan inode %lu will point to %d\n",
2818 inode->i_ino, NEXT_ORPHAN(inode));
2819 out:
2820 ext4_std_error(sb, err);
2821 return err;
2822 }
2823
2824 /*
2825 * ext4_orphan_del() removes an unlinked or truncated inode from the list
2826 * of such inodes stored on disk, because it is finally being cleaned up.
2827 */
2828 int ext4_orphan_del(handle_t *handle, struct inode *inode)
2829 {
2830 struct list_head *prev;
2831 struct ext4_inode_info *ei = EXT4_I(inode);
2832 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2833 __u32 ino_next;
2834 struct ext4_iloc iloc;
2835 int err = 0;
2836
2837 if (!sbi->s_journal && !(sbi->s_mount_state & EXT4_ORPHAN_FS))
2838 return 0;
2839
2840 WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
2841 !inode_is_locked(inode));
2842 /* Do this quick check before taking global s_orphan_lock. */
2843 if (list_empty(&ei->i_orphan))
2844 return 0;
2845
2846 if (handle) {
2847 /* Grab inode buffer early before taking global s_orphan_lock */
2848 err = ext4_reserve_inode_write(handle, inode, &iloc);
2849 }
2850
2851 mutex_lock(&sbi->s_orphan_lock);
2852 jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
2853
2854 prev = ei->i_orphan.prev;
2855 list_del_init(&ei->i_orphan);
2856
2857 /* If we're on an error path, we may not have a valid
2858 * transaction handle with which to update the orphan list on
2859 * disk, but we still need to remove the inode from the linked
2860 * list in memory. */
2861 if (!handle || err) {
2862 mutex_unlock(&sbi->s_orphan_lock);
2863 goto out_err;
2864 }
2865
2866 ino_next = NEXT_ORPHAN(inode);
2867 if (prev == &sbi->s_orphan) {
2868 jbd_debug(4, "superblock will point to %u\n", ino_next);
2869 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2870 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2871 if (err) {
2872 mutex_unlock(&sbi->s_orphan_lock);
2873 goto out_brelse;
2874 }
2875 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
2876 mutex_unlock(&sbi->s_orphan_lock);
2877 err = ext4_handle_dirty_super(handle, inode->i_sb);
2878 } else {
2879 struct ext4_iloc iloc2;
2880 struct inode *i_prev =
2881 &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
2882
2883 jbd_debug(4, "orphan inode %lu will point to %u\n",
2884 i_prev->i_ino, ino_next);
2885 err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
2886 if (err) {
2887 mutex_unlock(&sbi->s_orphan_lock);
2888 goto out_brelse;
2889 }
2890 NEXT_ORPHAN(i_prev) = ino_next;
2891 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
2892 mutex_unlock(&sbi->s_orphan_lock);
2893 }
2894 if (err)
2895 goto out_brelse;
2896 NEXT_ORPHAN(inode) = 0;
2897 err = ext4_mark_iloc_dirty(handle, inode, &iloc);
2898 out_err:
2899 ext4_std_error(inode->i_sb, err);
2900 return err;
2901
2902 out_brelse:
2903 brelse(iloc.bh);
2904 goto out_err;
2905 }
2906
2907 static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
2908 {
2909 int retval;
2910 struct inode *inode;
2911 struct buffer_head *bh;
2912 struct ext4_dir_entry_2 *de;
2913 handle_t *handle = NULL;
2914
2915 if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
2916 return -EIO;
2917
2918 /* Initialize quotas before so that eventual writes go in
2919 * separate transaction */
2920 retval = dquot_initialize(dir);
2921 if (retval)
2922 return retval;
2923 retval = dquot_initialize(d_inode(dentry));
2924 if (retval)
2925 return retval;
2926
2927 retval = -ENOENT;
2928 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
2929 if (IS_ERR(bh))
2930 return PTR_ERR(bh);
2931 if (!bh)
2932 goto end_rmdir;
2933
2934 inode = d_inode(dentry);
2935
2936 retval = -EFSCORRUPTED;
2937 if (le32_to_cpu(de->inode) != inode->i_ino)
2938 goto end_rmdir;
2939
2940 retval = -ENOTEMPTY;
2941 if (!ext4_empty_dir(inode))
2942 goto end_rmdir;
2943
2944 handle = ext4_journal_start(dir, EXT4_HT_DIR,
2945 EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
2946 if (IS_ERR(handle)) {
2947 retval = PTR_ERR(handle);
2948 handle = NULL;
2949 goto end_rmdir;
2950 }
2951
2952 if (IS_DIRSYNC(dir))
2953 ext4_handle_sync(handle);
2954
2955 retval = ext4_delete_entry(handle, dir, de, bh);
2956 if (retval)
2957 goto end_rmdir;
2958 if (!EXT4_DIR_LINK_EMPTY(inode))
2959 ext4_warning_inode(inode,
2960 "empty directory '%.*s' has too many links (%u)",
2961 dentry->d_name.len, dentry->d_name.name,
2962 inode->i_nlink);
2963 inode_inc_iversion(inode);
2964 clear_nlink(inode);
2965 /* There's no need to set i_disksize: the fact that i_nlink is
2966 * zero will ensure that the right thing happens during any
2967 * recovery. */
2968 inode->i_size = 0;
2969 ext4_orphan_add(handle, inode);
2970 inode->i_ctime = dir->i_ctime = dir->i_mtime = current_time(inode);
2971 ext4_mark_inode_dirty(handle, inode);
2972 ext4_dec_count(handle, dir);
2973 ext4_update_dx_flag(dir);
2974 ext4_mark_inode_dirty(handle, dir);
2975
2976 end_rmdir:
2977 brelse(bh);
2978 if (handle)
2979 ext4_journal_stop(handle);
2980 return retval;
2981 }
2982
2983 static int ext4_unlink(struct inode *dir, struct dentry *dentry)
2984 {
2985 int retval;
2986 struct inode *inode;
2987 struct buffer_head *bh;
2988 struct ext4_dir_entry_2 *de;
2989 handle_t *handle = NULL;
2990
2991 if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
2992 return -EIO;
2993
2994 trace_ext4_unlink_enter(dir, dentry);
2995 /* Initialize quotas before so that eventual writes go
2996 * in separate transaction */
2997 retval = dquot_initialize(dir);
2998 if (retval)
2999 return retval;
3000 retval = dquot_initialize(d_inode(dentry));
3001 if (retval)
3002 return retval;
3003
3004 retval = -ENOENT;
3005 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
3006 if (IS_ERR(bh))
3007 return PTR_ERR(bh);
3008 if (!bh)
3009 goto end_unlink;
3010
3011 inode = d_inode(dentry);
3012
3013 retval = -EFSCORRUPTED;
3014 if (le32_to_cpu(de->inode) != inode->i_ino)
3015 goto end_unlink;
3016
3017 handle = ext4_journal_start(dir, EXT4_HT_DIR,
3018 EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
3019 if (IS_ERR(handle)) {
3020 retval = PTR_ERR(handle);
3021 handle = NULL;
3022 goto end_unlink;
3023 }
3024
3025 if (IS_DIRSYNC(dir))
3026 ext4_handle_sync(handle);
3027
3028 if (inode->i_nlink == 0) {
3029 ext4_warning_inode(inode, "Deleting file '%.*s' with no links",
3030 dentry->d_name.len, dentry->d_name.name);
3031 set_nlink(inode, 1);
3032 }
3033 retval = ext4_delete_entry(handle, dir, de, bh);
3034 if (retval)
3035 goto end_unlink;
3036 dir->i_ctime = dir->i_mtime = current_time(dir);
3037 ext4_update_dx_flag(dir);
3038 ext4_mark_inode_dirty(handle, dir);
3039 drop_nlink(inode);
3040 if (!inode->i_nlink)
3041 ext4_orphan_add(handle, inode);
3042 inode->i_ctime = current_time(inode);
3043 ext4_mark_inode_dirty(handle, inode);
3044
3045 end_unlink:
3046 brelse(bh);
3047 if (handle)
3048 ext4_journal_stop(handle);
3049 trace_ext4_unlink_exit(dentry, retval);
3050 return retval;
3051 }
3052
3053 static int ext4_symlink(struct inode *dir,
3054 struct dentry *dentry, const char *symname)
3055 {
3056 handle_t *handle;
3057 struct inode *inode;
3058 int err, len = strlen(symname);
3059 int credits;
3060 struct fscrypt_str disk_link;
3061
3062 if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
3063 return -EIO;
3064
3065 err = fscrypt_prepare_symlink(dir, symname, len, dir->i_sb->s_blocksize,
3066 &disk_link);
3067 if (err)
3068 return err;
3069
3070 err = dquot_initialize(dir);
3071 if (err)
3072 return err;
3073
3074 if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
3075 /*
3076 * For non-fast symlinks, we just allocate inode and put it on
3077 * orphan list in the first transaction => we need bitmap,
3078 * group descriptor, sb, inode block, quota blocks, and
3079 * possibly selinux xattr blocks.
3080 */
3081 credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
3082 EXT4_XATTR_TRANS_BLOCKS;
3083 } else {
3084 /*
3085 * Fast symlink. We have to add entry to directory
3086 * (EXT4_DATA_TRANS_BLOCKS + EXT4_INDEX_EXTRA_TRANS_BLOCKS),
3087 * allocate new inode (bitmap, group descriptor, inode block,
3088 * quota blocks, sb is already counted in previous macros).
3089 */
3090 credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3091 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3;
3092 }
3093
3094 inode = ext4_new_inode_start_handle(dir, S_IFLNK|S_IRWXUGO,
3095 &dentry->d_name, 0, NULL,
3096 EXT4_HT_DIR, credits);
3097 handle = ext4_journal_current_handle();
3098 if (IS_ERR(inode)) {
3099 if (handle)
3100 ext4_journal_stop(handle);
3101 return PTR_ERR(inode);
3102 }
3103
3104 if (IS_ENCRYPTED(inode)) {
3105 err = fscrypt_encrypt_symlink(inode, symname, len, &disk_link);
3106 if (err)
3107 goto err_drop_inode;
3108 inode->i_op = &ext4_encrypted_symlink_inode_operations;
3109 }
3110
3111 if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
3112 if (!IS_ENCRYPTED(inode))
3113 inode->i_op = &ext4_symlink_inode_operations;
3114 inode_nohighmem(inode);
3115 ext4_set_aops(inode);
3116 /*
3117 * We cannot call page_symlink() with transaction started
3118 * because it calls into ext4_write_begin() which can wait
3119 * for transaction commit if we are running out of space
3120 * and thus we deadlock. So we have to stop transaction now
3121 * and restart it when symlink contents is written.
3122 *
3123 * To keep fs consistent in case of crash, we have to put inode
3124 * to orphan list in the mean time.
3125 */
3126 drop_nlink(inode);
3127 err = ext4_orphan_add(handle, inode);
3128 ext4_journal_stop(handle);
3129 handle = NULL;
3130 if (err)
3131 goto err_drop_inode;
3132 err = __page_symlink(inode, disk_link.name, disk_link.len, 1);
3133 if (err)
3134 goto err_drop_inode;
3135 /*
3136 * Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS
3137 * + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified
3138 */
3139 handle = ext4_journal_start(dir, EXT4_HT_DIR,
3140 EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3141 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1);
3142 if (IS_ERR(handle)) {
3143 err = PTR_ERR(handle);
3144 handle = NULL;
3145 goto err_drop_inode;
3146 }
3147 set_nlink(inode, 1);
3148 err = ext4_orphan_del(handle, inode);
3149 if (err)
3150 goto err_drop_inode;
3151 } else {
3152 /* clear the extent format for fast symlink */
3153 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
3154 if (!IS_ENCRYPTED(inode)) {
3155 inode->i_op = &ext4_fast_symlink_inode_operations;
3156 inode->i_link = (char *)&EXT4_I(inode)->i_data;
3157 }
3158 memcpy((char *)&EXT4_I(inode)->i_data, disk_link.name,
3159 disk_link.len);
3160 inode->i_size = disk_link.len - 1;
3161 }
3162 EXT4_I(inode)->i_disksize = inode->i_size;
3163 err = ext4_add_nondir(handle, dentry, inode);
3164 if (!err && IS_DIRSYNC(dir))
3165 ext4_handle_sync(handle);
3166
3167 if (handle)
3168 ext4_journal_stop(handle);
3169 goto out_free_encrypted_link;
3170
3171 err_drop_inode:
3172 if (handle)
3173 ext4_journal_stop(handle);
3174 clear_nlink(inode);
3175 unlock_new_inode(inode);
3176 iput(inode);
3177 out_free_encrypted_link:
3178 if (disk_link.name != (unsigned char *)symname)
3179 kfree(disk_link.name);
3180 return err;
3181 }
3182
3183 static int ext4_link(struct dentry *old_dentry,
3184 struct inode *dir, struct dentry *dentry)
3185 {
3186 handle_t *handle;
3187 struct inode *inode = d_inode(old_dentry);
3188 int err, retries = 0;
3189
3190 if (inode->i_nlink >= EXT4_LINK_MAX)
3191 return -EMLINK;
3192
3193 err = fscrypt_prepare_link(old_dentry, dir, dentry);
3194 if (err)
3195 return err;
3196
3197 if ((ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT)) &&
3198 (!projid_eq(EXT4_I(dir)->i_projid,
3199 EXT4_I(old_dentry->d_inode)->i_projid)))
3200 return -EXDEV;
3201
3202 err = dquot_initialize(dir);
3203 if (err)
3204 return err;
3205
3206 retry:
3207 handle = ext4_journal_start(dir, EXT4_HT_DIR,
3208 (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3209 EXT4_INDEX_EXTRA_TRANS_BLOCKS) + 1);
3210 if (IS_ERR(handle))
3211 return PTR_ERR(handle);
3212
3213 if (IS_DIRSYNC(dir))
3214 ext4_handle_sync(handle);
3215
3216 inode->i_ctime = current_time(inode);
3217 ext4_inc_count(handle, inode);
3218 ihold(inode);
3219
3220 err = ext4_add_entry(handle, dentry, inode);
3221 if (!err) {
3222 ext4_mark_inode_dirty(handle, inode);
3223 /* this can happen only for tmpfile being
3224 * linked the first time
3225 */
3226 if (inode->i_nlink == 1)
3227 ext4_orphan_del(handle, inode);
3228 d_instantiate(dentry, inode);
3229 } else {
3230 drop_nlink(inode);
3231 iput(inode);
3232 }
3233 ext4_journal_stop(handle);
3234 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
3235 goto retry;
3236 return err;
3237 }
3238
3239
3240 /*
3241 * Try to find buffer head where contains the parent block.
3242 * It should be the inode block if it is inlined or the 1st block
3243 * if it is a normal dir.
3244 */
3245 static struct buffer_head *ext4_get_first_dir_block(handle_t *handle,
3246 struct inode *inode,
3247 int *retval,
3248 struct ext4_dir_entry_2 **parent_de,
3249 int *inlined)
3250 {
3251 struct buffer_head *bh;
3252
3253 if (!ext4_has_inline_data(inode)) {
3254 bh = ext4_read_dirblock(inode, 0, EITHER);
3255 if (IS_ERR(bh)) {
3256 *retval = PTR_ERR(bh);
3257 return NULL;
3258 }
3259 *parent_de = ext4_next_entry(
3260 (struct ext4_dir_entry_2 *)bh->b_data,
3261 inode->i_sb->s_blocksize);
3262 return bh;
3263 }
3264
3265 *inlined = 1;
3266 return ext4_get_first_inline_block(inode, parent_de, retval);
3267 }
3268
3269 struct ext4_renament {
3270 struct inode *dir;
3271 struct dentry *dentry;
3272 struct inode *inode;
3273 bool is_dir;
3274 int dir_nlink_delta;
3275
3276 /* entry for "dentry" */
3277 struct buffer_head *bh;
3278 struct ext4_dir_entry_2 *de;
3279 int inlined;
3280
3281 /* entry for ".." in inode if it's a directory */
3282 struct buffer_head *dir_bh;
3283 struct ext4_dir_entry_2 *parent_de;
3284 int dir_inlined;
3285 };
3286
3287 static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent)
3288 {
3289 int retval;
3290
3291 ent->dir_bh = ext4_get_first_dir_block(handle, ent->inode,
3292 &retval, &ent->parent_de,
3293 &ent->dir_inlined);
3294 if (!ent->dir_bh)
3295 return retval;
3296 if (le32_to_cpu(ent->parent_de->inode) != ent->dir->i_ino)
3297 return -EFSCORRUPTED;
3298 BUFFER_TRACE(ent->dir_bh, "get_write_access");
3299 return ext4_journal_get_write_access(handle, ent->dir_bh);
3300 }
3301
3302 static int ext4_rename_dir_finish(handle_t *handle, struct ext4_renament *ent,
3303 unsigned dir_ino)
3304 {
3305 int retval;
3306
3307 ent->parent_de->inode = cpu_to_le32(dir_ino);
3308 BUFFER_TRACE(ent->dir_bh, "call ext4_handle_dirty_metadata");
3309 if (!ent->dir_inlined) {
3310 if (is_dx(ent->inode)) {
3311 retval = ext4_handle_dirty_dx_node(handle,
3312 ent->inode,
3313 ent->dir_bh);
3314 } else {
3315 retval = ext4_handle_dirty_dirent_node(handle,
3316 ent->inode,
3317 ent->dir_bh);
3318 }
3319 } else {
3320 retval = ext4_mark_inode_dirty(handle, ent->inode);
3321 }
3322 if (retval) {
3323 ext4_std_error(ent->dir->i_sb, retval);
3324 return retval;
3325 }
3326 return 0;
3327 }
3328
3329 static int ext4_setent(handle_t *handle, struct ext4_renament *ent,
3330 unsigned ino, unsigned file_type)
3331 {
3332 int retval;
3333
3334 BUFFER_TRACE(ent->bh, "get write access");
3335 retval = ext4_journal_get_write_access(handle, ent->bh);
3336 if (retval)
3337 return retval;
3338 ent->de->inode = cpu_to_le32(ino);
3339 if (ext4_has_feature_filetype(ent->dir->i_sb))
3340 ent->de->file_type = file_type;
3341 inode_inc_iversion(ent->dir);
3342 ent->dir->i_ctime = ent->dir->i_mtime =
3343 current_time(ent->dir);
3344 ext4_mark_inode_dirty(handle, ent->dir);
3345 BUFFER_TRACE(ent->bh, "call ext4_handle_dirty_metadata");
3346 if (!ent->inlined) {
3347 retval = ext4_handle_dirty_dirent_node(handle,
3348 ent->dir, ent->bh);
3349 if (unlikely(retval)) {
3350 ext4_std_error(ent->dir->i_sb, retval);
3351 return retval;
3352 }
3353 }
3354 brelse(ent->bh);
3355 ent->bh = NULL;
3356
3357 return 0;
3358 }
3359
3360 static int ext4_find_delete_entry(handle_t *handle, struct inode *dir,
3361 const struct qstr *d_name)
3362 {
3363 int retval = -ENOENT;
3364 struct buffer_head *bh;
3365 struct ext4_dir_entry_2 *de;
3366
3367 bh = ext4_find_entry(dir, d_name, &de, NULL);
3368 if (IS_ERR(bh))
3369 return PTR_ERR(bh);
3370 if (bh) {
3371 retval = ext4_delete_entry(handle, dir, de, bh);
3372 brelse(bh);
3373 }
3374 return retval;
3375 }
3376
3377 static void ext4_rename_delete(handle_t *handle, struct ext4_renament *ent,
3378 int force_reread)
3379 {
3380 int retval;
3381 /*
3382 * ent->de could have moved from under us during htree split, so make
3383 * sure that we are deleting the right entry. We might also be pointing
3384 * to a stale entry in the unused part of ent->bh so just checking inum
3385 * and the name isn't enough.
3386 */
3387 if (le32_to_cpu(ent->de->inode) != ent->inode->i_ino ||
3388 ent->de->name_len != ent->dentry->d_name.len ||
3389 strncmp(ent->de->name, ent->dentry->d_name.name,
3390 ent->de->name_len) ||
3391 force_reread) {
3392 retval = ext4_find_delete_entry(handle, ent->dir,
3393 &ent->dentry->d_name);
3394 } else {
3395 retval = ext4_delete_entry(handle, ent->dir, ent->de, ent->bh);
3396 if (retval == -ENOENT) {
3397 retval = ext4_find_delete_entry(handle, ent->dir,
3398 &ent->dentry->d_name);
3399 }
3400 }
3401
3402 if (retval) {
3403 ext4_warning_inode(ent->dir,
3404 "Deleting old file: nlink %d, error=%d",
3405 ent->dir->i_nlink, retval);
3406 }
3407 }
3408
3409 static void ext4_update_dir_count(handle_t *handle, struct ext4_renament *ent)
3410 {
3411 if (ent->dir_nlink_delta) {
3412 if (ent->dir_nlink_delta == -1)
3413 ext4_dec_count(handle, ent->dir);
3414 else
3415 ext4_inc_count(handle, ent->dir);
3416 ext4_mark_inode_dirty(handle, ent->dir);
3417 }
3418 }
3419
3420 static struct inode *ext4_whiteout_for_rename(struct ext4_renament *ent,
3421 int credits, handle_t **h)
3422 {
3423 struct inode *wh;
3424 handle_t *handle;
3425 int retries = 0;
3426
3427 /*
3428 * for inode block, sb block, group summaries,
3429 * and inode bitmap
3430 */
3431 credits += (EXT4_MAXQUOTAS_TRANS_BLOCKS(ent->dir->i_sb) +
3432 EXT4_XATTR_TRANS_BLOCKS + 4);
3433 retry:
3434 wh = ext4_new_inode_start_handle(ent->dir, S_IFCHR | WHITEOUT_MODE,
3435 &ent->dentry->d_name, 0, NULL,
3436 EXT4_HT_DIR, credits);
3437
3438 handle = ext4_journal_current_handle();
3439 if (IS_ERR(wh)) {
3440 if (handle)
3441 ext4_journal_stop(handle);
3442 if (PTR_ERR(wh) == -ENOSPC &&
3443 ext4_should_retry_alloc(ent->dir->i_sb, &retries))
3444 goto retry;
3445 } else {
3446 *h = handle;
3447 init_special_inode(wh, wh->i_mode, WHITEOUT_DEV);
3448 wh->i_op = &ext4_special_inode_operations;
3449 }
3450 return wh;
3451 }
3452
3453 /*
3454 * Anybody can rename anything with this: the permission checks are left to the
3455 * higher-level routines.
3456 *
3457 * n.b. old_{dentry,inode) refers to the source dentry/inode
3458 * while new_{dentry,inode) refers to the destination dentry/inode
3459 * This comes from rename(const char *oldpath, const char *newpath)
3460 */
3461 static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
3462 struct inode *new_dir, struct dentry *new_dentry,
3463 unsigned int flags)
3464 {
3465 handle_t *handle = NULL;
3466 struct ext4_renament old = {
3467 .dir = old_dir,
3468 .dentry = old_dentry,
3469 .inode = d_inode(old_dentry),
3470 };
3471 struct ext4_renament new = {
3472 .dir = new_dir,
3473 .dentry = new_dentry,
3474 .inode = d_inode(new_dentry),
3475 };
3476 int force_reread;
3477 int retval;
3478 struct inode *whiteout = NULL;
3479 int credits;
3480 u8 old_file_type;
3481
3482 if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT)) &&
3483 (!projid_eq(EXT4_I(new_dir)->i_projid,
3484 EXT4_I(old_dentry->d_inode)->i_projid)))
3485 return -EXDEV;
3486
3487 retval = dquot_initialize(old.dir);
3488 if (retval)
3489 return retval;
3490 retval = dquot_initialize(new.dir);
3491 if (retval)
3492 return retval;
3493
3494 /* Initialize quotas before so that eventual writes go
3495 * in separate transaction */
3496 if (new.inode) {
3497 retval = dquot_initialize(new.inode);
3498 if (retval)
3499 return retval;
3500 }
3501
3502 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, NULL);
3503 if (IS_ERR(old.bh))
3504 return PTR_ERR(old.bh);
3505 /*
3506 * Check for inode number is _not_ due to possible IO errors.
3507 * We might rmdir the source, keep it as pwd of some process
3508 * and merrily kill the link to whatever was created under the
3509 * same name. Goodbye sticky bit ;-<
3510 */
3511 retval = -ENOENT;
3512 if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3513 goto end_rename;
3514
3515 new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
3516 &new.de, &new.inlined);
3517 if (IS_ERR(new.bh)) {
3518 retval = PTR_ERR(new.bh);
3519 new.bh = NULL;
3520 goto end_rename;
3521 }
3522 if (new.bh) {
3523 if (!new.inode) {
3524 brelse(new.bh);
3525 new.bh = NULL;
3526 }
3527 }
3528 if (new.inode && !test_opt(new.dir->i_sb, NO_AUTO_DA_ALLOC))
3529 ext4_alloc_da_blocks(old.inode);
3530
3531 credits = (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3532 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
3533 if (!(flags & RENAME_WHITEOUT)) {
3534 handle = ext4_journal_start(old.dir, EXT4_HT_DIR, credits);
3535 if (IS_ERR(handle)) {
3536 retval = PTR_ERR(handle);
3537 handle = NULL;
3538 goto end_rename;
3539 }
3540 } else {
3541 whiteout = ext4_whiteout_for_rename(&old, credits, &handle);
3542 if (IS_ERR(whiteout)) {
3543 retval = PTR_ERR(whiteout);
3544 whiteout = NULL;
3545 goto end_rename;
3546 }
3547 }
3548
3549 if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3550 ext4_handle_sync(handle);
3551
3552 if (S_ISDIR(old.inode->i_mode)) {
3553 if (new.inode) {
3554 retval = -ENOTEMPTY;
3555 if (!ext4_empty_dir(new.inode))
3556 goto end_rename;
3557 } else {
3558 retval = -EMLINK;
3559 if (new.dir != old.dir && EXT4_DIR_LINK_MAX(new.dir))
3560 goto end_rename;
3561 }
3562 retval = ext4_rename_dir_prepare(handle, &old);
3563 if (retval)
3564 goto end_rename;
3565 }
3566 /*
3567 * If we're renaming a file within an inline_data dir and adding or
3568 * setting the new dirent causes a conversion from inline_data to
3569 * extents/blockmap, we need to force the dirent delete code to
3570 * re-read the directory, or else we end up trying to delete a dirent
3571 * from what is now the extent tree root (or a block map).
3572 */
3573 force_reread = (new.dir->i_ino == old.dir->i_ino &&
3574 ext4_test_inode_flag(new.dir, EXT4_INODE_INLINE_DATA));
3575
3576 old_file_type = old.de->file_type;
3577 if (whiteout) {
3578 /*
3579 * Do this before adding a new entry, so the old entry is sure
3580 * to be still pointing to the valid old entry.
3581 */
3582 retval = ext4_setent(handle, &old, whiteout->i_ino,
3583 EXT4_FT_CHRDEV);
3584 if (retval)
3585 goto end_rename;
3586 ext4_mark_inode_dirty(handle, whiteout);
3587 }
3588 if (!new.bh) {
3589 retval = ext4_add_entry(handle, new.dentry, old.inode);
3590 if (retval)
3591 goto end_rename;
3592 } else {
3593 retval = ext4_setent(handle, &new,
3594 old.inode->i_ino, old_file_type);
3595 if (retval)
3596 goto end_rename;
3597 }
3598 if (force_reread)
3599 force_reread = !ext4_test_inode_flag(new.dir,
3600 EXT4_INODE_INLINE_DATA);
3601
3602 /*
3603 * Like most other Unix systems, set the ctime for inodes on a
3604 * rename.
3605 */
3606 old.inode->i_ctime = current_time(old.inode);
3607 ext4_mark_inode_dirty(handle, old.inode);
3608
3609 if (!whiteout) {
3610 /*
3611 * ok, that's it
3612 */
3613 ext4_rename_delete(handle, &old, force_reread);
3614 }
3615
3616 if (new.inode) {
3617 ext4_dec_count(handle, new.inode);
3618 new.inode->i_ctime = current_time(new.inode);
3619 }
3620 old.dir->i_ctime = old.dir->i_mtime = current_time(old.dir);
3621 ext4_update_dx_flag(old.dir);
3622 if (old.dir_bh) {
3623 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
3624 if (retval)
3625 goto end_rename;
3626
3627 ext4_dec_count(handle, old.dir);
3628 if (new.inode) {
3629 /* checked ext4_empty_dir above, can't have another
3630 * parent, ext4_dec_count() won't work for many-linked
3631 * dirs */
3632 clear_nlink(new.inode);
3633 } else {
3634 ext4_inc_count(handle, new.dir);
3635 ext4_update_dx_flag(new.dir);
3636 ext4_mark_inode_dirty(handle, new.dir);
3637 }
3638 }
3639 ext4_mark_inode_dirty(handle, old.dir);
3640 if (new.inode) {
3641 ext4_mark_inode_dirty(handle, new.inode);
3642 if (!new.inode->i_nlink)
3643 ext4_orphan_add(handle, new.inode);
3644 }
3645 retval = 0;
3646
3647 end_rename:
3648 brelse(old.dir_bh);
3649 brelse(old.bh);
3650 brelse(new.bh);
3651 if (whiteout) {
3652 if (retval)
3653 drop_nlink(whiteout);
3654 unlock_new_inode(whiteout);
3655 iput(whiteout);
3656 }
3657 if (handle)
3658 ext4_journal_stop(handle);
3659 return retval;
3660 }
3661
3662 static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
3663 struct inode *new_dir, struct dentry *new_dentry)
3664 {
3665 handle_t *handle = NULL;
3666 struct ext4_renament old = {
3667 .dir = old_dir,
3668 .dentry = old_dentry,
3669 .inode = d_inode(old_dentry),
3670 };
3671 struct ext4_renament new = {
3672 .dir = new_dir,
3673 .dentry = new_dentry,
3674 .inode = d_inode(new_dentry),
3675 };
3676 u8 new_file_type;
3677 int retval;
3678 struct timespec ctime;
3679
3680 if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT) &&
3681 !projid_eq(EXT4_I(new_dir)->i_projid,
3682 EXT4_I(old_dentry->d_inode)->i_projid)) ||
3683 (ext4_test_inode_flag(old_dir, EXT4_INODE_PROJINHERIT) &&
3684 !projid_eq(EXT4_I(old_dir)->i_projid,
3685 EXT4_I(new_dentry->d_inode)->i_projid)))
3686 return -EXDEV;
3687
3688 retval = dquot_initialize(old.dir);
3689 if (retval)
3690 return retval;
3691 retval = dquot_initialize(new.dir);
3692 if (retval)
3693 return retval;
3694
3695 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name,
3696 &old.de, &old.inlined);
3697 if (IS_ERR(old.bh))
3698 return PTR_ERR(old.bh);
3699 /*
3700 * Check for inode number is _not_ due to possible IO errors.
3701 * We might rmdir the source, keep it as pwd of some process
3702 * and merrily kill the link to whatever was created under the
3703 * same name. Goodbye sticky bit ;-<
3704 */
3705 retval = -ENOENT;
3706 if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3707 goto end_rename;
3708
3709 new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
3710 &new.de, &new.inlined);
3711 if (IS_ERR(new.bh)) {
3712 retval = PTR_ERR(new.bh);
3713 new.bh = NULL;
3714 goto end_rename;
3715 }
3716
3717 /* RENAME_EXCHANGE case: old *and* new must both exist */
3718 if (!new.bh || le32_to_cpu(new.de->inode) != new.inode->i_ino)
3719 goto end_rename;
3720
3721 handle = ext4_journal_start(old.dir, EXT4_HT_DIR,
3722 (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3723 2 * EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2));
3724 if (IS_ERR(handle)) {
3725 retval = PTR_ERR(handle);
3726 handle = NULL;
3727 goto end_rename;
3728 }
3729
3730 if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3731 ext4_handle_sync(handle);
3732
3733 if (S_ISDIR(old.inode->i_mode)) {
3734 old.is_dir = true;
3735 retval = ext4_rename_dir_prepare(handle, &old);
3736 if (retval)
3737 goto end_rename;
3738 }
3739 if (S_ISDIR(new.inode->i_mode)) {
3740 new.is_dir = true;
3741 retval = ext4_rename_dir_prepare(handle, &new);
3742 if (retval)
3743 goto end_rename;
3744 }
3745
3746 /*
3747 * Other than the special case of overwriting a directory, parents'
3748 * nlink only needs to be modified if this is a cross directory rename.
3749 */
3750 if (old.dir != new.dir && old.is_dir != new.is_dir) {
3751 old.dir_nlink_delta = old.is_dir ? -1 : 1;
3752 new.dir_nlink_delta = -old.dir_nlink_delta;
3753 retval = -EMLINK;
3754 if ((old.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(old.dir)) ||
3755 (new.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(new.dir)))
3756 goto end_rename;
3757 }
3758
3759 new_file_type = new.de->file_type;
3760 retval = ext4_setent(handle, &new, old.inode->i_ino, old.de->file_type);
3761 if (retval)
3762 goto end_rename;
3763
3764 retval = ext4_setent(handle, &old, new.inode->i_ino, new_file_type);
3765 if (retval)
3766 goto end_rename;
3767
3768 /*
3769 * Like most other Unix systems, set the ctime for inodes on a
3770 * rename.
3771 */
3772 ctime = current_time(old.inode);
3773 old.inode->i_ctime = ctime;
3774 new.inode->i_ctime = ctime;
3775 ext4_mark_inode_dirty(handle, old.inode);
3776 ext4_mark_inode_dirty(handle, new.inode);
3777
3778 if (old.dir_bh) {
3779 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
3780 if (retval)
3781 goto end_rename;
3782 }
3783 if (new.dir_bh) {
3784 retval = ext4_rename_dir_finish(handle, &new, old.dir->i_ino);
3785 if (retval)
3786 goto end_rename;
3787 }
3788 ext4_update_dir_count(handle, &old);
3789 ext4_update_dir_count(handle, &new);
3790 retval = 0;
3791
3792 end_rename:
3793 brelse(old.dir_bh);
3794 brelse(new.dir_bh);
3795 brelse(old.bh);
3796 brelse(new.bh);
3797 if (handle)
3798 ext4_journal_stop(handle);
3799 return retval;
3800 }
3801
3802 static int ext4_rename2(struct inode *old_dir, struct dentry *old_dentry,
3803 struct inode *new_dir, struct dentry *new_dentry,
3804 unsigned int flags)
3805 {
3806 int err;
3807
3808 if (unlikely(ext4_forced_shutdown(EXT4_SB(old_dir->i_sb))))
3809 return -EIO;
3810
3811 if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
3812 return -EINVAL;
3813
3814 err = fscrypt_prepare_rename(old_dir, old_dentry, new_dir, new_dentry,
3815 flags);
3816 if (err)
3817 return err;
3818
3819 if (flags & RENAME_EXCHANGE) {
3820 return ext4_cross_rename(old_dir, old_dentry,
3821 new_dir, new_dentry);
3822 }
3823
3824 return ext4_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
3825 }
3826
3827 /*
3828 * directories can handle most operations...
3829 */
3830 const struct inode_operations ext4_dir_inode_operations = {
3831 .create = ext4_create,
3832 .lookup = ext4_lookup,
3833 .link = ext4_link,
3834 .unlink = ext4_unlink,
3835 .symlink = ext4_symlink,
3836 .mkdir = ext4_mkdir,
3837 .rmdir = ext4_rmdir,
3838 .mknod = ext4_mknod,
3839 .tmpfile = ext4_tmpfile,
3840 .rename = ext4_rename2,
3841 .setattr = ext4_setattr,
3842 .getattr = ext4_getattr,
3843 .listxattr = ext4_listxattr,
3844 .get_acl = ext4_get_acl,
3845 .set_acl = ext4_set_acl,
3846 .fiemap = ext4_fiemap,
3847 };
3848
3849 const struct inode_operations ext4_special_inode_operations = {
3850 .setattr = ext4_setattr,
3851 .getattr = ext4_getattr,
3852 .listxattr = ext4_listxattr,
3853 .get_acl = ext4_get_acl,
3854 .set_acl = ext4_set_acl,
3855 };
CRIS linux kernel tree