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ext4: fix inode checksum calculation problem if i_extra_size is small
[mirror_ubuntu-artful-kernel.git] / fs / ext4 / namei.c
1 /*
2 * linux/fs/ext4/namei.c
3 *
4 * Copyright (C) 1992, 1993, 1994, 1995
5 * Remy Card (card@masi.ibp.fr)
6 * Laboratoire MASI - Institut Blaise Pascal
7 * Universite Pierre et Marie Curie (Paris VI)
8 *
9 * from
10 *
11 * linux/fs/minix/namei.c
12 *
13 * Copyright (C) 1991, 1992 Linus Torvalds
14 *
15 * Big-endian to little-endian byte-swapping/bitmaps by
16 * David S. Miller (davem@caip.rutgers.edu), 1995
17 * Directory entry file type support and forward compatibility hooks
18 * for B-tree directories by Theodore Ts'o (tytso@mit.edu), 1998
19 * Hash Tree Directory indexing (c)
20 * Daniel Phillips, 2001
21 * Hash Tree Directory indexing porting
22 * Christopher Li, 2002
23 * Hash Tree Directory indexing cleanup
24 * Theodore Ts'o, 2002
25 */
26
27 #include <linux/fs.h>
28 #include <linux/pagemap.h>
29 #include <linux/time.h>
30 #include <linux/fcntl.h>
31 #include <linux/stat.h>
32 #include <linux/string.h>
33 #include <linux/quotaops.h>
34 #include <linux/buffer_head.h>
35 #include <linux/bio.h>
36 #include "ext4.h"
37 #include "ext4_jbd2.h"
38
39 #include "xattr.h"
40 #include "acl.h"
41
42 #include <trace/events/ext4.h>
43 /*
44 * define how far ahead to read directories while searching them.
45 */
46 #define NAMEI_RA_CHUNKS 2
47 #define NAMEI_RA_BLOCKS 4
48 #define NAMEI_RA_SIZE (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS)
49
50 static struct buffer_head *ext4_append(handle_t *handle,
51 struct inode *inode,
52 ext4_lblk_t *block)
53 {
54 struct buffer_head *bh;
55 int err;
56
57 if (unlikely(EXT4_SB(inode->i_sb)->s_max_dir_size_kb &&
58 ((inode->i_size >> 10) >=
59 EXT4_SB(inode->i_sb)->s_max_dir_size_kb)))
60 return ERR_PTR(-ENOSPC);
61
62 *block = inode->i_size >> inode->i_sb->s_blocksize_bits;
63
64 bh = ext4_bread(handle, inode, *block, EXT4_GET_BLOCKS_CREATE);
65 if (IS_ERR(bh))
66 return bh;
67 inode->i_size += inode->i_sb->s_blocksize;
68 EXT4_I(inode)->i_disksize = inode->i_size;
69 BUFFER_TRACE(bh, "get_write_access");
70 err = ext4_journal_get_write_access(handle, bh);
71 if (err) {
72 brelse(bh);
73 ext4_std_error(inode->i_sb, err);
74 return ERR_PTR(err);
75 }
76 return bh;
77 }
78
79 static int ext4_dx_csum_verify(struct inode *inode,
80 struct ext4_dir_entry *dirent);
81
82 typedef enum {
83 EITHER, INDEX, DIRENT
84 } dirblock_type_t;
85
86 #define ext4_read_dirblock(inode, block, type) \
87 __ext4_read_dirblock((inode), (block), (type), __func__, __LINE__)
88
89 static struct buffer_head *__ext4_read_dirblock(struct inode *inode,
90 ext4_lblk_t block,
91 dirblock_type_t type,
92 const char *func,
93 unsigned int line)
94 {
95 struct buffer_head *bh;
96 struct ext4_dir_entry *dirent;
97 int is_dx_block = 0;
98
99 bh = ext4_bread(NULL, inode, block, 0);
100 if (IS_ERR(bh)) {
101 __ext4_warning(inode->i_sb, func, line,
102 "inode #%lu: lblock %lu: comm %s: "
103 "error %ld reading directory block",
104 inode->i_ino, (unsigned long)block,
105 current->comm, PTR_ERR(bh));
106
107 return bh;
108 }
109 if (!bh) {
110 ext4_error_inode(inode, func, line, block,
111 "Directory hole found");
112 return ERR_PTR(-EFSCORRUPTED);
113 }
114 dirent = (struct ext4_dir_entry *) bh->b_data;
115 /* Determine whether or not we have an index block */
116 if (is_dx(inode)) {
117 if (block == 0)
118 is_dx_block = 1;
119 else if (ext4_rec_len_from_disk(dirent->rec_len,
120 inode->i_sb->s_blocksize) ==
121 inode->i_sb->s_blocksize)
122 is_dx_block = 1;
123 }
124 if (!is_dx_block && type == INDEX) {
125 ext4_error_inode(inode, func, line, block,
126 "directory leaf block found instead of index block");
127 return ERR_PTR(-EFSCORRUPTED);
128 }
129 if (!ext4_has_metadata_csum(inode->i_sb) ||
130 buffer_verified(bh))
131 return bh;
132
133 /*
134 * An empty leaf block can get mistaken for a index block; for
135 * this reason, we can only check the index checksum when the
136 * caller is sure it should be an index block.
137 */
138 if (is_dx_block && type == INDEX) {
139 if (ext4_dx_csum_verify(inode, dirent))
140 set_buffer_verified(bh);
141 else {
142 ext4_error_inode(inode, func, line, block,
143 "Directory index failed checksum");
144 brelse(bh);
145 return ERR_PTR(-EFSBADCRC);
146 }
147 }
148 if (!is_dx_block) {
149 if (ext4_dirent_csum_verify(inode, dirent))
150 set_buffer_verified(bh);
151 else {
152 ext4_error_inode(inode, func, line, block,
153 "Directory block failed checksum");
154 brelse(bh);
155 return ERR_PTR(-EFSBADCRC);
156 }
157 }
158 return bh;
159 }
160
161 #ifndef assert
162 #define assert(test) J_ASSERT(test)
163 #endif
164
165 #ifdef DX_DEBUG
166 #define dxtrace(command) command
167 #else
168 #define dxtrace(command)
169 #endif
170
171 struct fake_dirent
172 {
173 __le32 inode;
174 __le16 rec_len;
175 u8 name_len;
176 u8 file_type;
177 };
178
179 struct dx_countlimit
180 {
181 __le16 limit;
182 __le16 count;
183 };
184
185 struct dx_entry
186 {
187 __le32 hash;
188 __le32 block;
189 };
190
191 /*
192 * dx_root_info is laid out so that if it should somehow get overlaid by a
193 * dirent the two low bits of the hash version will be zero. Therefore, the
194 * hash version mod 4 should never be 0. Sincerely, the paranoia department.
195 */
196
197 struct dx_root
198 {
199 struct fake_dirent dot;
200 char dot_name[4];
201 struct fake_dirent dotdot;
202 char dotdot_name[4];
203 struct dx_root_info
204 {
205 __le32 reserved_zero;
206 u8 hash_version;
207 u8 info_length; /* 8 */
208 u8 indirect_levels;
209 u8 unused_flags;
210 }
211 info;
212 struct dx_entry entries[0];
213 };
214
215 struct dx_node
216 {
217 struct fake_dirent fake;
218 struct dx_entry entries[0];
219 };
220
221
222 struct dx_frame
223 {
224 struct buffer_head *bh;
225 struct dx_entry *entries;
226 struct dx_entry *at;
227 };
228
229 struct dx_map_entry
230 {
231 u32 hash;
232 u16 offs;
233 u16 size;
234 };
235
236 /*
237 * This goes at the end of each htree block.
238 */
239 struct dx_tail {
240 u32 dt_reserved;
241 __le32 dt_checksum; /* crc32c(uuid+inum+dirblock) */
242 };
243
244 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
245 static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
246 static inline unsigned dx_get_hash(struct dx_entry *entry);
247 static void dx_set_hash(struct dx_entry *entry, unsigned value);
248 static unsigned dx_get_count(struct dx_entry *entries);
249 static unsigned dx_get_limit(struct dx_entry *entries);
250 static void dx_set_count(struct dx_entry *entries, unsigned value);
251 static void dx_set_limit(struct dx_entry *entries, unsigned value);
252 static unsigned dx_root_limit(struct inode *dir, unsigned infosize);
253 static unsigned dx_node_limit(struct inode *dir);
254 static struct dx_frame *dx_probe(struct ext4_filename *fname,
255 struct inode *dir,
256 struct dx_hash_info *hinfo,
257 struct dx_frame *frame);
258 static void dx_release(struct dx_frame *frames);
259 static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de,
260 unsigned blocksize, struct dx_hash_info *hinfo,
261 struct dx_map_entry map[]);
262 static void dx_sort_map(struct dx_map_entry *map, unsigned count);
263 static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to,
264 struct dx_map_entry *offsets, int count, unsigned blocksize);
265 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize);
266 static void dx_insert_block(struct dx_frame *frame,
267 u32 hash, ext4_lblk_t block);
268 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
269 struct dx_frame *frame,
270 struct dx_frame *frames,
271 __u32 *start_hash);
272 static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
273 struct ext4_filename *fname,
274 struct ext4_dir_entry_2 **res_dir);
275 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
276 struct dentry *dentry, struct inode *inode);
277
278 /* checksumming functions */
279 void initialize_dirent_tail(struct ext4_dir_entry_tail *t,
280 unsigned int blocksize)
281 {
282 memset(t, 0, sizeof(struct ext4_dir_entry_tail));
283 t->det_rec_len = ext4_rec_len_to_disk(
284 sizeof(struct ext4_dir_entry_tail), blocksize);
285 t->det_reserved_ft = EXT4_FT_DIR_CSUM;
286 }
287
288 /* Walk through a dirent block to find a checksum "dirent" at the tail */
289 static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode,
290 struct ext4_dir_entry *de)
291 {
292 struct ext4_dir_entry_tail *t;
293
294 #ifdef PARANOID
295 struct ext4_dir_entry *d, *top;
296
297 d = de;
298 top = (struct ext4_dir_entry *)(((void *)de) +
299 (EXT4_BLOCK_SIZE(inode->i_sb) -
300 sizeof(struct ext4_dir_entry_tail)));
301 while (d < top && d->rec_len)
302 d = (struct ext4_dir_entry *)(((void *)d) +
303 le16_to_cpu(d->rec_len));
304
305 if (d != top)
306 return NULL;
307
308 t = (struct ext4_dir_entry_tail *)d;
309 #else
310 t = EXT4_DIRENT_TAIL(de, EXT4_BLOCK_SIZE(inode->i_sb));
311 #endif
312
313 if (t->det_reserved_zero1 ||
314 le16_to_cpu(t->det_rec_len) != sizeof(struct ext4_dir_entry_tail) ||
315 t->det_reserved_zero2 ||
316 t->det_reserved_ft != EXT4_FT_DIR_CSUM)
317 return NULL;
318
319 return t;
320 }
321
322 static __le32 ext4_dirent_csum(struct inode *inode,
323 struct ext4_dir_entry *dirent, int size)
324 {
325 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
326 struct ext4_inode_info *ei = EXT4_I(inode);
327 __u32 csum;
328
329 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
330 return cpu_to_le32(csum);
331 }
332
333 #define warn_no_space_for_csum(inode) \
334 __warn_no_space_for_csum((inode), __func__, __LINE__)
335
336 static void __warn_no_space_for_csum(struct inode *inode, const char *func,
337 unsigned int line)
338 {
339 __ext4_warning_inode(inode, func, line,
340 "No space for directory leaf checksum. Please run e2fsck -D.");
341 }
342
343 int ext4_dirent_csum_verify(struct inode *inode, struct ext4_dir_entry *dirent)
344 {
345 struct ext4_dir_entry_tail *t;
346
347 if (!ext4_has_metadata_csum(inode->i_sb))
348 return 1;
349
350 t = get_dirent_tail(inode, dirent);
351 if (!t) {
352 warn_no_space_for_csum(inode);
353 return 0;
354 }
355
356 if (t->det_checksum != ext4_dirent_csum(inode, dirent,
357 (void *)t - (void *)dirent))
358 return 0;
359
360 return 1;
361 }
362
363 static void ext4_dirent_csum_set(struct inode *inode,
364 struct ext4_dir_entry *dirent)
365 {
366 struct ext4_dir_entry_tail *t;
367
368 if (!ext4_has_metadata_csum(inode->i_sb))
369 return;
370
371 t = get_dirent_tail(inode, dirent);
372 if (!t) {
373 warn_no_space_for_csum(inode);
374 return;
375 }
376
377 t->det_checksum = ext4_dirent_csum(inode, dirent,
378 (void *)t - (void *)dirent);
379 }
380
381 int ext4_handle_dirty_dirent_node(handle_t *handle,
382 struct inode *inode,
383 struct buffer_head *bh)
384 {
385 ext4_dirent_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
386 return ext4_handle_dirty_metadata(handle, inode, bh);
387 }
388
389 static struct dx_countlimit *get_dx_countlimit(struct inode *inode,
390 struct ext4_dir_entry *dirent,
391 int *offset)
392 {
393 struct ext4_dir_entry *dp;
394 struct dx_root_info *root;
395 int count_offset;
396
397 if (le16_to_cpu(dirent->rec_len) == EXT4_BLOCK_SIZE(inode->i_sb))
398 count_offset = 8;
399 else if (le16_to_cpu(dirent->rec_len) == 12) {
400 dp = (struct ext4_dir_entry *)(((void *)dirent) + 12);
401 if (le16_to_cpu(dp->rec_len) !=
402 EXT4_BLOCK_SIZE(inode->i_sb) - 12)
403 return NULL;
404 root = (struct dx_root_info *)(((void *)dp + 12));
405 if (root->reserved_zero ||
406 root->info_length != sizeof(struct dx_root_info))
407 return NULL;
408 count_offset = 32;
409 } else
410 return NULL;
411
412 if (offset)
413 *offset = count_offset;
414 return (struct dx_countlimit *)(((void *)dirent) + count_offset);
415 }
416
417 static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent,
418 int count_offset, int count, struct dx_tail *t)
419 {
420 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
421 struct ext4_inode_info *ei = EXT4_I(inode);
422 __u32 csum;
423 int size;
424 __u32 dummy_csum = 0;
425 int offset = offsetof(struct dx_tail, dt_checksum);
426
427 size = count_offset + (count * sizeof(struct dx_entry));
428 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
429 csum = ext4_chksum(sbi, csum, (__u8 *)t, offset);
430 csum = ext4_chksum(sbi, csum, (__u8 *)&dummy_csum, sizeof(dummy_csum));
431
432 return cpu_to_le32(csum);
433 }
434
435 static int ext4_dx_csum_verify(struct inode *inode,
436 struct ext4_dir_entry *dirent)
437 {
438 struct dx_countlimit *c;
439 struct dx_tail *t;
440 int count_offset, limit, count;
441
442 if (!ext4_has_metadata_csum(inode->i_sb))
443 return 1;
444
445 c = get_dx_countlimit(inode, dirent, &count_offset);
446 if (!c) {
447 EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D.");
448 return 1;
449 }
450 limit = le16_to_cpu(c->limit);
451 count = le16_to_cpu(c->count);
452 if (count_offset + (limit * sizeof(struct dx_entry)) >
453 EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
454 warn_no_space_for_csum(inode);
455 return 1;
456 }
457 t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
458
459 if (t->dt_checksum != ext4_dx_csum(inode, dirent, count_offset,
460 count, t))
461 return 0;
462 return 1;
463 }
464
465 static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent)
466 {
467 struct dx_countlimit *c;
468 struct dx_tail *t;
469 int count_offset, limit, count;
470
471 if (!ext4_has_metadata_csum(inode->i_sb))
472 return;
473
474 c = get_dx_countlimit(inode, dirent, &count_offset);
475 if (!c) {
476 EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D.");
477 return;
478 }
479 limit = le16_to_cpu(c->limit);
480 count = le16_to_cpu(c->count);
481 if (count_offset + (limit * sizeof(struct dx_entry)) >
482 EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
483 warn_no_space_for_csum(inode);
484 return;
485 }
486 t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
487
488 t->dt_checksum = ext4_dx_csum(inode, dirent, count_offset, count, t);
489 }
490
491 static inline int ext4_handle_dirty_dx_node(handle_t *handle,
492 struct inode *inode,
493 struct buffer_head *bh)
494 {
495 ext4_dx_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
496 return ext4_handle_dirty_metadata(handle, inode, bh);
497 }
498
499 /*
500 * p is at least 6 bytes before the end of page
501 */
502 static inline struct ext4_dir_entry_2 *
503 ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
504 {
505 return (struct ext4_dir_entry_2 *)((char *)p +
506 ext4_rec_len_from_disk(p->rec_len, blocksize));
507 }
508
509 /*
510 * Future: use high four bits of block for coalesce-on-delete flags
511 * Mask them off for now.
512 */
513
514 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
515 {
516 return le32_to_cpu(entry->block) & 0x00ffffff;
517 }
518
519 static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
520 {
521 entry->block = cpu_to_le32(value);
522 }
523
524 static inline unsigned dx_get_hash(struct dx_entry *entry)
525 {
526 return le32_to_cpu(entry->hash);
527 }
528
529 static inline void dx_set_hash(struct dx_entry *entry, unsigned value)
530 {
531 entry->hash = cpu_to_le32(value);
532 }
533
534 static inline unsigned dx_get_count(struct dx_entry *entries)
535 {
536 return le16_to_cpu(((struct dx_countlimit *) entries)->count);
537 }
538
539 static inline unsigned dx_get_limit(struct dx_entry *entries)
540 {
541 return le16_to_cpu(((struct dx_countlimit *) entries)->limit);
542 }
543
544 static inline void dx_set_count(struct dx_entry *entries, unsigned value)
545 {
546 ((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
547 }
548
549 static inline void dx_set_limit(struct dx_entry *entries, unsigned value)
550 {
551 ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
552 }
553
554 static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
555 {
556 unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
557 EXT4_DIR_REC_LEN(2) - infosize;
558
559 if (ext4_has_metadata_csum(dir->i_sb))
560 entry_space -= sizeof(struct dx_tail);
561 return entry_space / sizeof(struct dx_entry);
562 }
563
564 static inline unsigned dx_node_limit(struct inode *dir)
565 {
566 unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);
567
568 if (ext4_has_metadata_csum(dir->i_sb))
569 entry_space -= sizeof(struct dx_tail);
570 return entry_space / sizeof(struct dx_entry);
571 }
572
573 /*
574 * Debug
575 */
576 #ifdef DX_DEBUG
577 static void dx_show_index(char * label, struct dx_entry *entries)
578 {
579 int i, n = dx_get_count (entries);
580 printk(KERN_DEBUG "%s index ", label);
581 for (i = 0; i < n; i++) {
582 printk("%x->%lu ", i ? dx_get_hash(entries + i) :
583 0, (unsigned long)dx_get_block(entries + i));
584 }
585 printk("\n");
586 }
587
588 struct stats
589 {
590 unsigned names;
591 unsigned space;
592 unsigned bcount;
593 };
594
595 static struct stats dx_show_leaf(struct inode *dir,
596 struct dx_hash_info *hinfo,
597 struct ext4_dir_entry_2 *de,
598 int size, int show_names)
599 {
600 unsigned names = 0, space = 0;
601 char *base = (char *) de;
602 struct dx_hash_info h = *hinfo;
603
604 printk("names: ");
605 while ((char *) de < base + size)
606 {
607 if (de->inode)
608 {
609 if (show_names)
610 {
611 #ifdef CONFIG_EXT4_FS_ENCRYPTION
612 int len;
613 char *name;
614 struct ext4_str fname_crypto_str
615 = {.name = NULL, .len = 0};
616 int res = 0;
617
618 name = de->name;
619 len = de->name_len;
620 if (ext4_encrypted_inode(inode))
621 res = ext4_get_encryption_info(dir);
622 if (res) {
623 printk(KERN_WARNING "Error setting up"
624 " fname crypto: %d\n", res);
625 }
626 if (ctx == NULL) {
627 /* Directory is not encrypted */
628 ext4fs_dirhash(de->name,
629 de->name_len, &h);
630 printk("%*.s:(U)%x.%u ", len,
631 name, h.hash,
632 (unsigned) ((char *) de
633 - base));
634 } else {
635 /* Directory is encrypted */
636 res = ext4_fname_crypto_alloc_buffer(
637 ctx, de->name_len,
638 &fname_crypto_str);
639 if (res < 0) {
640 printk(KERN_WARNING "Error "
641 "allocating crypto "
642 "buffer--skipping "
643 "crypto\n");
644 ctx = NULL;
645 }
646 res = ext4_fname_disk_to_usr(ctx, NULL, de,
647 &fname_crypto_str);
648 if (res < 0) {
649 printk(KERN_WARNING "Error "
650 "converting filename "
651 "from disk to usr"
652 "\n");
653 name = "??";
654 len = 2;
655 } else {
656 name = fname_crypto_str.name;
657 len = fname_crypto_str.len;
658 }
659 ext4fs_dirhash(de->name, de->name_len,
660 &h);
661 printk("%*.s:(E)%x.%u ", len, name,
662 h.hash, (unsigned) ((char *) de
663 - base));
664 ext4_fname_crypto_free_buffer(
665 &fname_crypto_str);
666 }
667 #else
668 int len = de->name_len;
669 char *name = de->name;
670 ext4fs_dirhash(de->name, de->name_len, &h);
671 printk("%*.s:%x.%u ", len, name, h.hash,
672 (unsigned) ((char *) de - base));
673 #endif
674 }
675 space += EXT4_DIR_REC_LEN(de->name_len);
676 names++;
677 }
678 de = ext4_next_entry(de, size);
679 }
680 printk("(%i)\n", names);
681 return (struct stats) { names, space, 1 };
682 }
683
684 struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
685 struct dx_entry *entries, int levels)
686 {
687 unsigned blocksize = dir->i_sb->s_blocksize;
688 unsigned count = dx_get_count(entries), names = 0, space = 0, i;
689 unsigned bcount = 0;
690 struct buffer_head *bh;
691 printk("%i indexed blocks...\n", count);
692 for (i = 0; i < count; i++, entries++)
693 {
694 ext4_lblk_t block = dx_get_block(entries);
695 ext4_lblk_t hash = i ? dx_get_hash(entries): 0;
696 u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
697 struct stats stats;
698 printk("%s%3u:%03u hash %8x/%8x ",levels?"":" ", i, block, hash, range);
699 bh = ext4_bread(NULL,dir, block, 0);
700 if (!bh || IS_ERR(bh))
701 continue;
702 stats = levels?
703 dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
704 dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *)
705 bh->b_data, blocksize, 0);
706 names += stats.names;
707 space += stats.space;
708 bcount += stats.bcount;
709 brelse(bh);
710 }
711 if (bcount)
712 printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n",
713 levels ? "" : " ", names, space/bcount,
714 (space/bcount)*100/blocksize);
715 return (struct stats) { names, space, bcount};
716 }
717 #endif /* DX_DEBUG */
718
719 /*
720 * Probe for a directory leaf block to search.
721 *
722 * dx_probe can return ERR_BAD_DX_DIR, which means there was a format
723 * error in the directory index, and the caller should fall back to
724 * searching the directory normally. The callers of dx_probe **MUST**
725 * check for this error code, and make sure it never gets reflected
726 * back to userspace.
727 */
728 static struct dx_frame *
729 dx_probe(struct ext4_filename *fname, struct inode *dir,
730 struct dx_hash_info *hinfo, struct dx_frame *frame_in)
731 {
732 unsigned count, indirect;
733 struct dx_entry *at, *entries, *p, *q, *m;
734 struct dx_root *root;
735 struct dx_frame *frame = frame_in;
736 struct dx_frame *ret_err = ERR_PTR(ERR_BAD_DX_DIR);
737 u32 hash;
738
739 frame->bh = ext4_read_dirblock(dir, 0, INDEX);
740 if (IS_ERR(frame->bh))
741 return (struct dx_frame *) frame->bh;
742
743 root = (struct dx_root *) frame->bh->b_data;
744 if (root->info.hash_version != DX_HASH_TEA &&
745 root->info.hash_version != DX_HASH_HALF_MD4 &&
746 root->info.hash_version != DX_HASH_LEGACY) {
747 ext4_warning_inode(dir, "Unrecognised inode hash code %u",
748 root->info.hash_version);
749 goto fail;
750 }
751 if (fname)
752 hinfo = &fname->hinfo;
753 hinfo->hash_version = root->info.hash_version;
754 if (hinfo->hash_version <= DX_HASH_TEA)
755 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
756 hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
757 if (fname && fname_name(fname))
758 ext4fs_dirhash(fname_name(fname), fname_len(fname), hinfo);
759 hash = hinfo->hash;
760
761 if (root->info.unused_flags & 1) {
762 ext4_warning_inode(dir, "Unimplemented hash flags: %#06x",
763 root->info.unused_flags);
764 goto fail;
765 }
766
767 indirect = root->info.indirect_levels;
768 if (indirect > 1) {
769 ext4_warning_inode(dir, "Unimplemented hash depth: %#06x",
770 root->info.indirect_levels);
771 goto fail;
772 }
773
774 entries = (struct dx_entry *)(((char *)&root->info) +
775 root->info.info_length);
776
777 if (dx_get_limit(entries) != dx_root_limit(dir,
778 root->info.info_length)) {
779 ext4_warning_inode(dir, "dx entry: limit %u != root limit %u",
780 dx_get_limit(entries),
781 dx_root_limit(dir, root->info.info_length));
782 goto fail;
783 }
784
785 dxtrace(printk("Look up %x", hash));
786 while (1) {
787 count = dx_get_count(entries);
788 if (!count || count > dx_get_limit(entries)) {
789 ext4_warning_inode(dir,
790 "dx entry: count %u beyond limit %u",
791 count, dx_get_limit(entries));
792 goto fail;
793 }
794
795 p = entries + 1;
796 q = entries + count - 1;
797 while (p <= q) {
798 m = p + (q - p) / 2;
799 dxtrace(printk("."));
800 if (dx_get_hash(m) > hash)
801 q = m - 1;
802 else
803 p = m + 1;
804 }
805
806 if (0) { // linear search cross check
807 unsigned n = count - 1;
808 at = entries;
809 while (n--)
810 {
811 dxtrace(printk(","));
812 if (dx_get_hash(++at) > hash)
813 {
814 at--;
815 break;
816 }
817 }
818 assert (at == p - 1);
819 }
820
821 at = p - 1;
822 dxtrace(printk(" %x->%u\n", at == entries ? 0 : dx_get_hash(at),
823 dx_get_block(at)));
824 frame->entries = entries;
825 frame->at = at;
826 if (!indirect--)
827 return frame;
828 frame++;
829 frame->bh = ext4_read_dirblock(dir, dx_get_block(at), INDEX);
830 if (IS_ERR(frame->bh)) {
831 ret_err = (struct dx_frame *) frame->bh;
832 frame->bh = NULL;
833 goto fail;
834 }
835 entries = ((struct dx_node *) frame->bh->b_data)->entries;
836
837 if (dx_get_limit(entries) != dx_node_limit(dir)) {
838 ext4_warning_inode(dir,
839 "dx entry: limit %u != node limit %u",
840 dx_get_limit(entries), dx_node_limit(dir));
841 goto fail;
842 }
843 }
844 fail:
845 while (frame >= frame_in) {
846 brelse(frame->bh);
847 frame--;
848 }
849
850 if (ret_err == ERR_PTR(ERR_BAD_DX_DIR))
851 ext4_warning_inode(dir,
852 "Corrupt directory, running e2fsck is recommended");
853 return ret_err;
854 }
855
856 static void dx_release(struct dx_frame *frames)
857 {
858 if (frames[0].bh == NULL)
859 return;
860
861 if (((struct dx_root *)frames[0].bh->b_data)->info.indirect_levels)
862 brelse(frames[1].bh);
863 brelse(frames[0].bh);
864 }
865
866 /*
867 * This function increments the frame pointer to search the next leaf
868 * block, and reads in the necessary intervening nodes if the search
869 * should be necessary. Whether or not the search is necessary is
870 * controlled by the hash parameter. If the hash value is even, then
871 * the search is only continued if the next block starts with that
872 * hash value. This is used if we are searching for a specific file.
873 *
874 * If the hash value is HASH_NB_ALWAYS, then always go to the next block.
875 *
876 * This function returns 1 if the caller should continue to search,
877 * or 0 if it should not. If there is an error reading one of the
878 * index blocks, it will a negative error code.
879 *
880 * If start_hash is non-null, it will be filled in with the starting
881 * hash of the next page.
882 */
883 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
884 struct dx_frame *frame,
885 struct dx_frame *frames,
886 __u32 *start_hash)
887 {
888 struct dx_frame *p;
889 struct buffer_head *bh;
890 int num_frames = 0;
891 __u32 bhash;
892
893 p = frame;
894 /*
895 * Find the next leaf page by incrementing the frame pointer.
896 * If we run out of entries in the interior node, loop around and
897 * increment pointer in the parent node. When we break out of
898 * this loop, num_frames indicates the number of interior
899 * nodes need to be read.
900 */
901 while (1) {
902 if (++(p->at) < p->entries + dx_get_count(p->entries))
903 break;
904 if (p == frames)
905 return 0;
906 num_frames++;
907 p--;
908 }
909
910 /*
911 * If the hash is 1, then continue only if the next page has a
912 * continuation hash of any value. This is used for readdir
913 * handling. Otherwise, check to see if the hash matches the
914 * desired contiuation hash. If it doesn't, return since
915 * there's no point to read in the successive index pages.
916 */
917 bhash = dx_get_hash(p->at);
918 if (start_hash)
919 *start_hash = bhash;
920 if ((hash & 1) == 0) {
921 if ((bhash & ~1) != hash)
922 return 0;
923 }
924 /*
925 * If the hash is HASH_NB_ALWAYS, we always go to the next
926 * block so no check is necessary
927 */
928 while (num_frames--) {
929 bh = ext4_read_dirblock(dir, dx_get_block(p->at), INDEX);
930 if (IS_ERR(bh))
931 return PTR_ERR(bh);
932 p++;
933 brelse(p->bh);
934 p->bh = bh;
935 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
936 }
937 return 1;
938 }
939
940
941 /*
942 * This function fills a red-black tree with information from a
943 * directory block. It returns the number directory entries loaded
944 * into the tree. If there is an error it is returned in err.
945 */
946 static int htree_dirblock_to_tree(struct file *dir_file,
947 struct inode *dir, ext4_lblk_t block,
948 struct dx_hash_info *hinfo,
949 __u32 start_hash, __u32 start_minor_hash)
950 {
951 struct buffer_head *bh;
952 struct ext4_dir_entry_2 *de, *top;
953 int err = 0, count = 0;
954 struct ext4_str fname_crypto_str = {.name = NULL, .len = 0}, tmp_str;
955
956 dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
957 (unsigned long)block));
958 bh = ext4_read_dirblock(dir, block, DIRENT);
959 if (IS_ERR(bh))
960 return PTR_ERR(bh);
961
962 de = (struct ext4_dir_entry_2 *) bh->b_data;
963 top = (struct ext4_dir_entry_2 *) ((char *) de +
964 dir->i_sb->s_blocksize -
965 EXT4_DIR_REC_LEN(0));
966 #ifdef CONFIG_EXT4_FS_ENCRYPTION
967 /* Check if the directory is encrypted */
968 if (ext4_encrypted_inode(dir)) {
969 err = ext4_get_encryption_info(dir);
970 if (err < 0) {
971 brelse(bh);
972 return err;
973 }
974 err = ext4_fname_crypto_alloc_buffer(dir, EXT4_NAME_LEN,
975 &fname_crypto_str);
976 if (err < 0) {
977 brelse(bh);
978 return err;
979 }
980 }
981 #endif
982 for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) {
983 if (ext4_check_dir_entry(dir, NULL, de, bh,
984 bh->b_data, bh->b_size,
985 (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
986 + ((char *)de - bh->b_data))) {
987 /* silently ignore the rest of the block */
988 break;
989 }
990 ext4fs_dirhash(de->name, de->name_len, hinfo);
991 if ((hinfo->hash < start_hash) ||
992 ((hinfo->hash == start_hash) &&
993 (hinfo->minor_hash < start_minor_hash)))
994 continue;
995 if (de->inode == 0)
996 continue;
997 if (!ext4_encrypted_inode(dir)) {
998 tmp_str.name = de->name;
999 tmp_str.len = de->name_len;
1000 err = ext4_htree_store_dirent(dir_file,
1001 hinfo->hash, hinfo->minor_hash, de,
1002 &tmp_str);
1003 } else {
1004 int save_len = fname_crypto_str.len;
1005
1006 /* Directory is encrypted */
1007 err = ext4_fname_disk_to_usr(dir, hinfo, de,
1008 &fname_crypto_str);
1009 if (err < 0) {
1010 count = err;
1011 goto errout;
1012 }
1013 err = ext4_htree_store_dirent(dir_file,
1014 hinfo->hash, hinfo->minor_hash, de,
1015 &fname_crypto_str);
1016 fname_crypto_str.len = save_len;
1017 }
1018 if (err != 0) {
1019 count = err;
1020 goto errout;
1021 }
1022 count++;
1023 }
1024 errout:
1025 brelse(bh);
1026 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1027 ext4_fname_crypto_free_buffer(&fname_crypto_str);
1028 #endif
1029 return count;
1030 }
1031
1032
1033 /*
1034 * This function fills a red-black tree with information from a
1035 * directory. We start scanning the directory in hash order, starting
1036 * at start_hash and start_minor_hash.
1037 *
1038 * This function returns the number of entries inserted into the tree,
1039 * or a negative error code.
1040 */
1041 int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
1042 __u32 start_minor_hash, __u32 *next_hash)
1043 {
1044 struct dx_hash_info hinfo;
1045 struct ext4_dir_entry_2 *de;
1046 struct dx_frame frames[2], *frame;
1047 struct inode *dir;
1048 ext4_lblk_t block;
1049 int count = 0;
1050 int ret, err;
1051 __u32 hashval;
1052 struct ext4_str tmp_str;
1053
1054 dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
1055 start_hash, start_minor_hash));
1056 dir = file_inode(dir_file);
1057 if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) {
1058 hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
1059 if (hinfo.hash_version <= DX_HASH_TEA)
1060 hinfo.hash_version +=
1061 EXT4_SB(dir->i_sb)->s_hash_unsigned;
1062 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
1063 if (ext4_has_inline_data(dir)) {
1064 int has_inline_data = 1;
1065 count = htree_inlinedir_to_tree(dir_file, dir, 0,
1066 &hinfo, start_hash,
1067 start_minor_hash,
1068 &has_inline_data);
1069 if (has_inline_data) {
1070 *next_hash = ~0;
1071 return count;
1072 }
1073 }
1074 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
1075 start_hash, start_minor_hash);
1076 *next_hash = ~0;
1077 return count;
1078 }
1079 hinfo.hash = start_hash;
1080 hinfo.minor_hash = 0;
1081 frame = dx_probe(NULL, dir, &hinfo, frames);
1082 if (IS_ERR(frame))
1083 return PTR_ERR(frame);
1084
1085 /* Add '.' and '..' from the htree header */
1086 if (!start_hash && !start_minor_hash) {
1087 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
1088 tmp_str.name = de->name;
1089 tmp_str.len = de->name_len;
1090 err = ext4_htree_store_dirent(dir_file, 0, 0,
1091 de, &tmp_str);
1092 if (err != 0)
1093 goto errout;
1094 count++;
1095 }
1096 if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
1097 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
1098 de = ext4_next_entry(de, dir->i_sb->s_blocksize);
1099 tmp_str.name = de->name;
1100 tmp_str.len = de->name_len;
1101 err = ext4_htree_store_dirent(dir_file, 2, 0,
1102 de, &tmp_str);
1103 if (err != 0)
1104 goto errout;
1105 count++;
1106 }
1107
1108 while (1) {
1109 block = dx_get_block(frame->at);
1110 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
1111 start_hash, start_minor_hash);
1112 if (ret < 0) {
1113 err = ret;
1114 goto errout;
1115 }
1116 count += ret;
1117 hashval = ~0;
1118 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
1119 frame, frames, &hashval);
1120 *next_hash = hashval;
1121 if (ret < 0) {
1122 err = ret;
1123 goto errout;
1124 }
1125 /*
1126 * Stop if: (a) there are no more entries, or
1127 * (b) we have inserted at least one entry and the
1128 * next hash value is not a continuation
1129 */
1130 if ((ret == 0) ||
1131 (count && ((hashval & 1) == 0)))
1132 break;
1133 }
1134 dx_release(frames);
1135 dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, "
1136 "next hash: %x\n", count, *next_hash));
1137 return count;
1138 errout:
1139 dx_release(frames);
1140 return (err);
1141 }
1142
1143 static inline int search_dirblock(struct buffer_head *bh,
1144 struct inode *dir,
1145 struct ext4_filename *fname,
1146 const struct qstr *d_name,
1147 unsigned int offset,
1148 struct ext4_dir_entry_2 **res_dir)
1149 {
1150 return ext4_search_dir(bh, bh->b_data, dir->i_sb->s_blocksize, dir,
1151 fname, d_name, offset, res_dir);
1152 }
1153
1154 /*
1155 * Directory block splitting, compacting
1156 */
1157
1158 /*
1159 * Create map of hash values, offsets, and sizes, stored at end of block.
1160 * Returns number of entries mapped.
1161 */
1162 static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de,
1163 unsigned blocksize, struct dx_hash_info *hinfo,
1164 struct dx_map_entry *map_tail)
1165 {
1166 int count = 0;
1167 char *base = (char *) de;
1168 struct dx_hash_info h = *hinfo;
1169
1170 while ((char *) de < base + blocksize) {
1171 if (de->name_len && de->inode) {
1172 ext4fs_dirhash(de->name, de->name_len, &h);
1173 map_tail--;
1174 map_tail->hash = h.hash;
1175 map_tail->offs = ((char *) de - base)>>2;
1176 map_tail->size = le16_to_cpu(de->rec_len);
1177 count++;
1178 cond_resched();
1179 }
1180 /* XXX: do we need to check rec_len == 0 case? -Chris */
1181 de = ext4_next_entry(de, blocksize);
1182 }
1183 return count;
1184 }
1185
1186 /* Sort map by hash value */
1187 static void dx_sort_map (struct dx_map_entry *map, unsigned count)
1188 {
1189 struct dx_map_entry *p, *q, *top = map + count - 1;
1190 int more;
1191 /* Combsort until bubble sort doesn't suck */
1192 while (count > 2) {
1193 count = count*10/13;
1194 if (count - 9 < 2) /* 9, 10 -> 11 */
1195 count = 11;
1196 for (p = top, q = p - count; q >= map; p--, q--)
1197 if (p->hash < q->hash)
1198 swap(*p, *q);
1199 }
1200 /* Garden variety bubble sort */
1201 do {
1202 more = 0;
1203 q = top;
1204 while (q-- > map) {
1205 if (q[1].hash >= q[0].hash)
1206 continue;
1207 swap(*(q+1), *q);
1208 more = 1;
1209 }
1210 } while(more);
1211 }
1212
1213 static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
1214 {
1215 struct dx_entry *entries = frame->entries;
1216 struct dx_entry *old = frame->at, *new = old + 1;
1217 int count = dx_get_count(entries);
1218
1219 assert(count < dx_get_limit(entries));
1220 assert(old < entries + count);
1221 memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
1222 dx_set_hash(new, hash);
1223 dx_set_block(new, block);
1224 dx_set_count(entries, count + 1);
1225 }
1226
1227 /*
1228 * NOTE! unlike strncmp, ext4_match returns 1 for success, 0 for failure.
1229 *
1230 * `len <= EXT4_NAME_LEN' is guaranteed by caller.
1231 * `de != NULL' is guaranteed by caller.
1232 */
1233 static inline int ext4_match(struct ext4_filename *fname,
1234 struct ext4_dir_entry_2 *de)
1235 {
1236 const void *name = fname_name(fname);
1237 u32 len = fname_len(fname);
1238
1239 if (!de->inode)
1240 return 0;
1241
1242 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1243 if (unlikely(!name)) {
1244 if (fname->usr_fname->name[0] == '_') {
1245 int ret;
1246 if (de->name_len < 16)
1247 return 0;
1248 ret = memcmp(de->name + de->name_len - 16,
1249 fname->crypto_buf.name + 8, 16);
1250 return (ret == 0) ? 1 : 0;
1251 }
1252 name = fname->crypto_buf.name;
1253 len = fname->crypto_buf.len;
1254 }
1255 #endif
1256 if (de->name_len != len)
1257 return 0;
1258 return (memcmp(de->name, name, len) == 0) ? 1 : 0;
1259 }
1260
1261 /*
1262 * Returns 0 if not found, -1 on failure, and 1 on success
1263 */
1264 int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size,
1265 struct inode *dir, struct ext4_filename *fname,
1266 const struct qstr *d_name,
1267 unsigned int offset, struct ext4_dir_entry_2 **res_dir)
1268 {
1269 struct ext4_dir_entry_2 * de;
1270 char * dlimit;
1271 int de_len;
1272 int res;
1273
1274 de = (struct ext4_dir_entry_2 *)search_buf;
1275 dlimit = search_buf + buf_size;
1276 while ((char *) de < dlimit) {
1277 /* this code is executed quadratically often */
1278 /* do minimal checking `by hand' */
1279 if ((char *) de + de->name_len <= dlimit) {
1280 res = ext4_match(fname, de);
1281 if (res < 0) {
1282 res = -1;
1283 goto return_result;
1284 }
1285 if (res > 0) {
1286 /* found a match - just to be sure, do
1287 * a full check */
1288 if (ext4_check_dir_entry(dir, NULL, de, bh,
1289 bh->b_data,
1290 bh->b_size, offset)) {
1291 res = -1;
1292 goto return_result;
1293 }
1294 *res_dir = de;
1295 res = 1;
1296 goto return_result;
1297 }
1298
1299 }
1300 /* prevent looping on a bad block */
1301 de_len = ext4_rec_len_from_disk(de->rec_len,
1302 dir->i_sb->s_blocksize);
1303 if (de_len <= 0) {
1304 res = -1;
1305 goto return_result;
1306 }
1307 offset += de_len;
1308 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
1309 }
1310
1311 res = 0;
1312 return_result:
1313 return res;
1314 }
1315
1316 static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block,
1317 struct ext4_dir_entry *de)
1318 {
1319 struct super_block *sb = dir->i_sb;
1320
1321 if (!is_dx(dir))
1322 return 0;
1323 if (block == 0)
1324 return 1;
1325 if (de->inode == 0 &&
1326 ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) ==
1327 sb->s_blocksize)
1328 return 1;
1329 return 0;
1330 }
1331
1332 /*
1333 * ext4_find_entry()
1334 *
1335 * finds an entry in the specified directory with the wanted name. It
1336 * returns the cache buffer in which the entry was found, and the entry
1337 * itself (as a parameter - res_dir). It does NOT read the inode of the
1338 * entry - you'll have to do that yourself if you want to.
1339 *
1340 * The returned buffer_head has ->b_count elevated. The caller is expected
1341 * to brelse() it when appropriate.
1342 */
1343 static struct buffer_head * ext4_find_entry (struct inode *dir,
1344 const struct qstr *d_name,
1345 struct ext4_dir_entry_2 **res_dir,
1346 int *inlined)
1347 {
1348 struct super_block *sb;
1349 struct buffer_head *bh_use[NAMEI_RA_SIZE];
1350 struct buffer_head *bh, *ret = NULL;
1351 ext4_lblk_t start, block, b;
1352 const u8 *name = d_name->name;
1353 int ra_max = 0; /* Number of bh's in the readahead
1354 buffer, bh_use[] */
1355 int ra_ptr = 0; /* Current index into readahead
1356 buffer */
1357 int num = 0;
1358 ext4_lblk_t nblocks;
1359 int i, namelen, retval;
1360 struct ext4_filename fname;
1361
1362 *res_dir = NULL;
1363 sb = dir->i_sb;
1364 namelen = d_name->len;
1365 if (namelen > EXT4_NAME_LEN)
1366 return NULL;
1367
1368 retval = ext4_fname_setup_filename(dir, d_name, 1, &fname);
1369 if (retval)
1370 return ERR_PTR(retval);
1371
1372 if (ext4_has_inline_data(dir)) {
1373 int has_inline_data = 1;
1374 ret = ext4_find_inline_entry(dir, &fname, d_name, res_dir,
1375 &has_inline_data);
1376 if (has_inline_data) {
1377 if (inlined)
1378 *inlined = 1;
1379 goto cleanup_and_exit;
1380 }
1381 }
1382
1383 if ((namelen <= 2) && (name[0] == '.') &&
1384 (name[1] == '.' || name[1] == '\0')) {
1385 /*
1386 * "." or ".." will only be in the first block
1387 * NFS may look up ".."; "." should be handled by the VFS
1388 */
1389 block = start = 0;
1390 nblocks = 1;
1391 goto restart;
1392 }
1393 if (is_dx(dir)) {
1394 ret = ext4_dx_find_entry(dir, &fname, res_dir);
1395 /*
1396 * On success, or if the error was file not found,
1397 * return. Otherwise, fall back to doing a search the
1398 * old fashioned way.
1399 */
1400 if (!IS_ERR(ret) || PTR_ERR(ret) != ERR_BAD_DX_DIR)
1401 goto cleanup_and_exit;
1402 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
1403 "falling back\n"));
1404 }
1405 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1406 start = EXT4_I(dir)->i_dir_start_lookup;
1407 if (start >= nblocks)
1408 start = 0;
1409 block = start;
1410 restart:
1411 do {
1412 /*
1413 * We deal with the read-ahead logic here.
1414 */
1415 if (ra_ptr >= ra_max) {
1416 /* Refill the readahead buffer */
1417 ra_ptr = 0;
1418 b = block;
1419 for (ra_max = 0; ra_max < NAMEI_RA_SIZE; ra_max++) {
1420 /*
1421 * Terminate if we reach the end of the
1422 * directory and must wrap, or if our
1423 * search has finished at this block.
1424 */
1425 if (b >= nblocks || (num && block == start)) {
1426 bh_use[ra_max] = NULL;
1427 break;
1428 }
1429 num++;
1430 bh = ext4_getblk(NULL, dir, b++, 0);
1431 if (IS_ERR(bh)) {
1432 if (ra_max == 0) {
1433 ret = bh;
1434 goto cleanup_and_exit;
1435 }
1436 break;
1437 }
1438 bh_use[ra_max] = bh;
1439 if (bh)
1440 ll_rw_block(READ | REQ_META | REQ_PRIO,
1441 1, &bh);
1442 }
1443 }
1444 if ((bh = bh_use[ra_ptr++]) == NULL)
1445 goto next;
1446 wait_on_buffer(bh);
1447 if (!buffer_uptodate(bh)) {
1448 /* read error, skip block & hope for the best */
1449 EXT4_ERROR_INODE(dir, "reading directory lblock %lu",
1450 (unsigned long) block);
1451 brelse(bh);
1452 goto next;
1453 }
1454 if (!buffer_verified(bh) &&
1455 !is_dx_internal_node(dir, block,
1456 (struct ext4_dir_entry *)bh->b_data) &&
1457 !ext4_dirent_csum_verify(dir,
1458 (struct ext4_dir_entry *)bh->b_data)) {
1459 EXT4_ERROR_INODE(dir, "checksumming directory "
1460 "block %lu", (unsigned long)block);
1461 brelse(bh);
1462 goto next;
1463 }
1464 set_buffer_verified(bh);
1465 i = search_dirblock(bh, dir, &fname, d_name,
1466 block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
1467 if (i == 1) {
1468 EXT4_I(dir)->i_dir_start_lookup = block;
1469 ret = bh;
1470 goto cleanup_and_exit;
1471 } else {
1472 brelse(bh);
1473 if (i < 0)
1474 goto cleanup_and_exit;
1475 }
1476 next:
1477 if (++block >= nblocks)
1478 block = 0;
1479 } while (block != start);
1480
1481 /*
1482 * If the directory has grown while we were searching, then
1483 * search the last part of the directory before giving up.
1484 */
1485 block = nblocks;
1486 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1487 if (block < nblocks) {
1488 start = 0;
1489 goto restart;
1490 }
1491
1492 cleanup_and_exit:
1493 /* Clean up the read-ahead blocks */
1494 for (; ra_ptr < ra_max; ra_ptr++)
1495 brelse(bh_use[ra_ptr]);
1496 ext4_fname_free_filename(&fname);
1497 return ret;
1498 }
1499
1500 static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
1501 struct ext4_filename *fname,
1502 struct ext4_dir_entry_2 **res_dir)
1503 {
1504 struct super_block * sb = dir->i_sb;
1505 struct dx_frame frames[2], *frame;
1506 const struct qstr *d_name = fname->usr_fname;
1507 struct buffer_head *bh;
1508 ext4_lblk_t block;
1509 int retval;
1510
1511 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1512 *res_dir = NULL;
1513 #endif
1514 frame = dx_probe(fname, dir, NULL, frames);
1515 if (IS_ERR(frame))
1516 return (struct buffer_head *) frame;
1517 do {
1518 block = dx_get_block(frame->at);
1519 bh = ext4_read_dirblock(dir, block, DIRENT);
1520 if (IS_ERR(bh))
1521 goto errout;
1522
1523 retval = search_dirblock(bh, dir, fname, d_name,
1524 block << EXT4_BLOCK_SIZE_BITS(sb),
1525 res_dir);
1526 if (retval == 1)
1527 goto success;
1528 brelse(bh);
1529 if (retval == -1) {
1530 bh = ERR_PTR(ERR_BAD_DX_DIR);
1531 goto errout;
1532 }
1533
1534 /* Check to see if we should continue to search */
1535 retval = ext4_htree_next_block(dir, fname->hinfo.hash, frame,
1536 frames, NULL);
1537 if (retval < 0) {
1538 ext4_warning_inode(dir,
1539 "error %d reading directory index block",
1540 retval);
1541 bh = ERR_PTR(retval);
1542 goto errout;
1543 }
1544 } while (retval == 1);
1545
1546 bh = NULL;
1547 errout:
1548 dxtrace(printk(KERN_DEBUG "%s not found\n", d_name->name));
1549 success:
1550 dx_release(frames);
1551 return bh;
1552 }
1553
1554 static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
1555 {
1556 struct inode *inode;
1557 struct ext4_dir_entry_2 *de;
1558 struct buffer_head *bh;
1559
1560 if (dentry->d_name.len > EXT4_NAME_LEN)
1561 return ERR_PTR(-ENAMETOOLONG);
1562
1563 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
1564 if (IS_ERR(bh))
1565 return (struct dentry *) bh;
1566 inode = NULL;
1567 if (bh) {
1568 __u32 ino = le32_to_cpu(de->inode);
1569 brelse(bh);
1570 if (!ext4_valid_inum(dir->i_sb, ino)) {
1571 EXT4_ERROR_INODE(dir, "bad inode number: %u", ino);
1572 return ERR_PTR(-EFSCORRUPTED);
1573 }
1574 if (unlikely(ino == dir->i_ino)) {
1575 EXT4_ERROR_INODE(dir, "'%pd' linked to parent dir",
1576 dentry);
1577 return ERR_PTR(-EFSCORRUPTED);
1578 }
1579 inode = ext4_iget_normal(dir->i_sb, ino);
1580 if (inode == ERR_PTR(-ESTALE)) {
1581 EXT4_ERROR_INODE(dir,
1582 "deleted inode referenced: %u",
1583 ino);
1584 return ERR_PTR(-EFSCORRUPTED);
1585 }
1586 if (!IS_ERR(inode) && ext4_encrypted_inode(dir) &&
1587 (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
1588 S_ISLNK(inode->i_mode)) &&
1589 !ext4_is_child_context_consistent_with_parent(dir,
1590 inode)) {
1591 iput(inode);
1592 ext4_warning(inode->i_sb,
1593 "Inconsistent encryption contexts: %lu/%lu\n",
1594 (unsigned long) dir->i_ino,
1595 (unsigned long) inode->i_ino);
1596 return ERR_PTR(-EPERM);
1597 }
1598 }
1599 return d_splice_alias(inode, dentry);
1600 }
1601
1602
1603 struct dentry *ext4_get_parent(struct dentry *child)
1604 {
1605 __u32 ino;
1606 static const struct qstr dotdot = QSTR_INIT("..", 2);
1607 struct ext4_dir_entry_2 * de;
1608 struct buffer_head *bh;
1609
1610 bh = ext4_find_entry(d_inode(child), &dotdot, &de, NULL);
1611 if (IS_ERR(bh))
1612 return (struct dentry *) bh;
1613 if (!bh)
1614 return ERR_PTR(-ENOENT);
1615 ino = le32_to_cpu(de->inode);
1616 brelse(bh);
1617
1618 if (!ext4_valid_inum(d_inode(child)->i_sb, ino)) {
1619 EXT4_ERROR_INODE(d_inode(child),
1620 "bad parent inode number: %u", ino);
1621 return ERR_PTR(-EFSCORRUPTED);
1622 }
1623
1624 return d_obtain_alias(ext4_iget_normal(d_inode(child)->i_sb, ino));
1625 }
1626
1627 /*
1628 * Move count entries from end of map between two memory locations.
1629 * Returns pointer to last entry moved.
1630 */
1631 static struct ext4_dir_entry_2 *
1632 dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count,
1633 unsigned blocksize)
1634 {
1635 unsigned rec_len = 0;
1636
1637 while (count--) {
1638 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
1639 (from + (map->offs<<2));
1640 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1641 memcpy (to, de, rec_len);
1642 ((struct ext4_dir_entry_2 *) to)->rec_len =
1643 ext4_rec_len_to_disk(rec_len, blocksize);
1644 de->inode = 0;
1645 map++;
1646 to += rec_len;
1647 }
1648 return (struct ext4_dir_entry_2 *) (to - rec_len);
1649 }
1650
1651 /*
1652 * Compact each dir entry in the range to the minimal rec_len.
1653 * Returns pointer to last entry in range.
1654 */
1655 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize)
1656 {
1657 struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
1658 unsigned rec_len = 0;
1659
1660 prev = to = de;
1661 while ((char*)de < base + blocksize) {
1662 next = ext4_next_entry(de, blocksize);
1663 if (de->inode && de->name_len) {
1664 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1665 if (de > to)
1666 memmove(to, de, rec_len);
1667 to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
1668 prev = to;
1669 to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
1670 }
1671 de = next;
1672 }
1673 return prev;
1674 }
1675
1676 /*
1677 * Split a full leaf block to make room for a new dir entry.
1678 * Allocate a new block, and move entries so that they are approx. equally full.
1679 * Returns pointer to de in block into which the new entry will be inserted.
1680 */
1681 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
1682 struct buffer_head **bh,struct dx_frame *frame,
1683 struct dx_hash_info *hinfo)
1684 {
1685 unsigned blocksize = dir->i_sb->s_blocksize;
1686 unsigned count, continued;
1687 struct buffer_head *bh2;
1688 ext4_lblk_t newblock;
1689 u32 hash2;
1690 struct dx_map_entry *map;
1691 char *data1 = (*bh)->b_data, *data2;
1692 unsigned split, move, size;
1693 struct ext4_dir_entry_2 *de = NULL, *de2;
1694 struct ext4_dir_entry_tail *t;
1695 int csum_size = 0;
1696 int err = 0, i;
1697
1698 if (ext4_has_metadata_csum(dir->i_sb))
1699 csum_size = sizeof(struct ext4_dir_entry_tail);
1700
1701 bh2 = ext4_append(handle, dir, &newblock);
1702 if (IS_ERR(bh2)) {
1703 brelse(*bh);
1704 *bh = NULL;
1705 return (struct ext4_dir_entry_2 *) bh2;
1706 }
1707
1708 BUFFER_TRACE(*bh, "get_write_access");
1709 err = ext4_journal_get_write_access(handle, *bh);
1710 if (err)
1711 goto journal_error;
1712
1713 BUFFER_TRACE(frame->bh, "get_write_access");
1714 err = ext4_journal_get_write_access(handle, frame->bh);
1715 if (err)
1716 goto journal_error;
1717
1718 data2 = bh2->b_data;
1719
1720 /* create map in the end of data2 block */
1721 map = (struct dx_map_entry *) (data2 + blocksize);
1722 count = dx_make_map(dir, (struct ext4_dir_entry_2 *) data1,
1723 blocksize, hinfo, map);
1724 map -= count;
1725 dx_sort_map(map, count);
1726 /* Split the existing block in the middle, size-wise */
1727 size = 0;
1728 move = 0;
1729 for (i = count-1; i >= 0; i--) {
1730 /* is more than half of this entry in 2nd half of the block? */
1731 if (size + map[i].size/2 > blocksize/2)
1732 break;
1733 size += map[i].size;
1734 move++;
1735 }
1736 /* map index at which we will split */
1737 split = count - move;
1738 hash2 = map[split].hash;
1739 continued = hash2 == map[split - 1].hash;
1740 dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
1741 (unsigned long)dx_get_block(frame->at),
1742 hash2, split, count-split));
1743
1744 /* Fancy dance to stay within two buffers */
1745 de2 = dx_move_dirents(data1, data2, map + split, count - split,
1746 blocksize);
1747 de = dx_pack_dirents(data1, blocksize);
1748 de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
1749 (char *) de,
1750 blocksize);
1751 de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
1752 (char *) de2,
1753 blocksize);
1754 if (csum_size) {
1755 t = EXT4_DIRENT_TAIL(data2, blocksize);
1756 initialize_dirent_tail(t, blocksize);
1757
1758 t = EXT4_DIRENT_TAIL(data1, blocksize);
1759 initialize_dirent_tail(t, blocksize);
1760 }
1761
1762 dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data1,
1763 blocksize, 1));
1764 dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data2,
1765 blocksize, 1));
1766
1767 /* Which block gets the new entry? */
1768 if (hinfo->hash >= hash2) {
1769 swap(*bh, bh2);
1770 de = de2;
1771 }
1772 dx_insert_block(frame, hash2 + continued, newblock);
1773 err = ext4_handle_dirty_dirent_node(handle, dir, bh2);
1774 if (err)
1775 goto journal_error;
1776 err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
1777 if (err)
1778 goto journal_error;
1779 brelse(bh2);
1780 dxtrace(dx_show_index("frame", frame->entries));
1781 return de;
1782
1783 journal_error:
1784 brelse(*bh);
1785 brelse(bh2);
1786 *bh = NULL;
1787 ext4_std_error(dir->i_sb, err);
1788 return ERR_PTR(err);
1789 }
1790
1791 int ext4_find_dest_de(struct inode *dir, struct inode *inode,
1792 struct buffer_head *bh,
1793 void *buf, int buf_size,
1794 struct ext4_filename *fname,
1795 struct ext4_dir_entry_2 **dest_de)
1796 {
1797 struct ext4_dir_entry_2 *de;
1798 unsigned short reclen = EXT4_DIR_REC_LEN(fname_len(fname));
1799 int nlen, rlen;
1800 unsigned int offset = 0;
1801 char *top;
1802 int res;
1803
1804 de = (struct ext4_dir_entry_2 *)buf;
1805 top = buf + buf_size - reclen;
1806 while ((char *) de <= top) {
1807 if (ext4_check_dir_entry(dir, NULL, de, bh,
1808 buf, buf_size, offset)) {
1809 res = -EFSCORRUPTED;
1810 goto return_result;
1811 }
1812 /* Provide crypto context and crypto buffer to ext4 match */
1813 res = ext4_match(fname, de);
1814 if (res < 0)
1815 goto return_result;
1816 if (res > 0) {
1817 res = -EEXIST;
1818 goto return_result;
1819 }
1820 nlen = EXT4_DIR_REC_LEN(de->name_len);
1821 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
1822 if ((de->inode ? rlen - nlen : rlen) >= reclen)
1823 break;
1824 de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
1825 offset += rlen;
1826 }
1827
1828 if ((char *) de > top)
1829 res = -ENOSPC;
1830 else {
1831 *dest_de = de;
1832 res = 0;
1833 }
1834 return_result:
1835 return res;
1836 }
1837
1838 int ext4_insert_dentry(struct inode *dir,
1839 struct inode *inode,
1840 struct ext4_dir_entry_2 *de,
1841 int buf_size,
1842 struct ext4_filename *fname)
1843 {
1844
1845 int nlen, rlen;
1846
1847 nlen = EXT4_DIR_REC_LEN(de->name_len);
1848 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
1849 if (de->inode) {
1850 struct ext4_dir_entry_2 *de1 =
1851 (struct ext4_dir_entry_2 *)((char *)de + nlen);
1852 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, buf_size);
1853 de->rec_len = ext4_rec_len_to_disk(nlen, buf_size);
1854 de = de1;
1855 }
1856 de->file_type = EXT4_FT_UNKNOWN;
1857 de->inode = cpu_to_le32(inode->i_ino);
1858 ext4_set_de_type(inode->i_sb, de, inode->i_mode);
1859 de->name_len = fname_len(fname);
1860 memcpy(de->name, fname_name(fname), fname_len(fname));
1861 return 0;
1862 }
1863
1864 /*
1865 * Add a new entry into a directory (leaf) block. If de is non-NULL,
1866 * it points to a directory entry which is guaranteed to be large
1867 * enough for new directory entry. If de is NULL, then
1868 * add_dirent_to_buf will attempt search the directory block for
1869 * space. It will return -ENOSPC if no space is available, and -EIO
1870 * and -EEXIST if directory entry already exists.
1871 */
1872 static int add_dirent_to_buf(handle_t *handle, struct ext4_filename *fname,
1873 struct inode *dir,
1874 struct inode *inode, struct ext4_dir_entry_2 *de,
1875 struct buffer_head *bh)
1876 {
1877 unsigned int blocksize = dir->i_sb->s_blocksize;
1878 int csum_size = 0;
1879 int err;
1880
1881 if (ext4_has_metadata_csum(inode->i_sb))
1882 csum_size = sizeof(struct ext4_dir_entry_tail);
1883
1884 if (!de) {
1885 err = ext4_find_dest_de(dir, inode, bh, bh->b_data,
1886 blocksize - csum_size, fname, &de);
1887 if (err)
1888 return err;
1889 }
1890 BUFFER_TRACE(bh, "get_write_access");
1891 err = ext4_journal_get_write_access(handle, bh);
1892 if (err) {
1893 ext4_std_error(dir->i_sb, err);
1894 return err;
1895 }
1896
1897 /* By now the buffer is marked for journaling. Due to crypto operations,
1898 * the following function call may fail */
1899 err = ext4_insert_dentry(dir, inode, de, blocksize, fname);
1900 if (err < 0)
1901 return err;
1902
1903 /*
1904 * XXX shouldn't update any times until successful
1905 * completion of syscall, but too many callers depend
1906 * on this.
1907 *
1908 * XXX similarly, too many callers depend on
1909 * ext4_new_inode() setting the times, but error
1910 * recovery deletes the inode, so the worst that can
1911 * happen is that the times are slightly out of date
1912 * and/or different from the directory change time.
1913 */
1914 dir->i_mtime = dir->i_ctime = ext4_current_time(dir);
1915 ext4_update_dx_flag(dir);
1916 dir->i_version++;
1917 ext4_mark_inode_dirty(handle, dir);
1918 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1919 err = ext4_handle_dirty_dirent_node(handle, dir, bh);
1920 if (err)
1921 ext4_std_error(dir->i_sb, err);
1922 return 0;
1923 }
1924
1925 /*
1926 * This converts a one block unindexed directory to a 3 block indexed
1927 * directory, and adds the dentry to the indexed directory.
1928 */
1929 static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname,
1930 struct dentry *dentry,
1931 struct inode *inode, struct buffer_head *bh)
1932 {
1933 struct inode *dir = d_inode(dentry->d_parent);
1934 struct buffer_head *bh2;
1935 struct dx_root *root;
1936 struct dx_frame frames[2], *frame;
1937 struct dx_entry *entries;
1938 struct ext4_dir_entry_2 *de, *de2;
1939 struct ext4_dir_entry_tail *t;
1940 char *data1, *top;
1941 unsigned len;
1942 int retval;
1943 unsigned blocksize;
1944 ext4_lblk_t block;
1945 struct fake_dirent *fde;
1946 int csum_size = 0;
1947
1948 if (ext4_has_metadata_csum(inode->i_sb))
1949 csum_size = sizeof(struct ext4_dir_entry_tail);
1950
1951 blocksize = dir->i_sb->s_blocksize;
1952 dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
1953 BUFFER_TRACE(bh, "get_write_access");
1954 retval = ext4_journal_get_write_access(handle, bh);
1955 if (retval) {
1956 ext4_std_error(dir->i_sb, retval);
1957 brelse(bh);
1958 return retval;
1959 }
1960 root = (struct dx_root *) bh->b_data;
1961
1962 /* The 0th block becomes the root, move the dirents out */
1963 fde = &root->dotdot;
1964 de = (struct ext4_dir_entry_2 *)((char *)fde +
1965 ext4_rec_len_from_disk(fde->rec_len, blocksize));
1966 if ((char *) de >= (((char *) root) + blocksize)) {
1967 EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
1968 brelse(bh);
1969 return -EFSCORRUPTED;
1970 }
1971 len = ((char *) root) + (blocksize - csum_size) - (char *) de;
1972
1973 /* Allocate new block for the 0th block's dirents */
1974 bh2 = ext4_append(handle, dir, &block);
1975 if (IS_ERR(bh2)) {
1976 brelse(bh);
1977 return PTR_ERR(bh2);
1978 }
1979 ext4_set_inode_flag(dir, EXT4_INODE_INDEX);
1980 data1 = bh2->b_data;
1981
1982 memcpy (data1, de, len);
1983 de = (struct ext4_dir_entry_2 *) data1;
1984 top = data1 + len;
1985 while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
1986 de = de2;
1987 de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
1988 (char *) de,
1989 blocksize);
1990
1991 if (csum_size) {
1992 t = EXT4_DIRENT_TAIL(data1, blocksize);
1993 initialize_dirent_tail(t, blocksize);
1994 }
1995
1996 /* Initialize the root; the dot dirents already exist */
1997 de = (struct ext4_dir_entry_2 *) (&root->dotdot);
1998 de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
1999 blocksize);
2000 memset (&root->info, 0, sizeof(root->info));
2001 root->info.info_length = sizeof(root->info);
2002 root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
2003 entries = root->entries;
2004 dx_set_block(entries, 1);
2005 dx_set_count(entries, 1);
2006 dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
2007
2008 /* Initialize as for dx_probe */
2009 fname->hinfo.hash_version = root->info.hash_version;
2010 if (fname->hinfo.hash_version <= DX_HASH_TEA)
2011 fname->hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
2012 fname->hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
2013 ext4fs_dirhash(fname_name(fname), fname_len(fname), &fname->hinfo);
2014
2015 memset(frames, 0, sizeof(frames));
2016 frame = frames;
2017 frame->entries = entries;
2018 frame->at = entries;
2019 frame->bh = bh;
2020
2021 retval = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
2022 if (retval)
2023 goto out_frames;
2024 retval = ext4_handle_dirty_dirent_node(handle, dir, bh2);
2025 if (retval)
2026 goto out_frames;
2027
2028 de = do_split(handle,dir, &bh2, frame, &fname->hinfo);
2029 if (IS_ERR(de)) {
2030 retval = PTR_ERR(de);
2031 goto out_frames;
2032 }
2033
2034 retval = add_dirent_to_buf(handle, fname, dir, inode, de, bh2);
2035 out_frames:
2036 /*
2037 * Even if the block split failed, we have to properly write
2038 * out all the changes we did so far. Otherwise we can end up
2039 * with corrupted filesystem.
2040 */
2041 if (retval)
2042 ext4_mark_inode_dirty(handle, dir);
2043 dx_release(frames);
2044 brelse(bh2);
2045 return retval;
2046 }
2047
2048 /*
2049 * ext4_add_entry()
2050 *
2051 * adds a file entry to the specified directory, using the same
2052 * semantics as ext4_find_entry(). It returns NULL if it failed.
2053 *
2054 * NOTE!! The inode part of 'de' is left at 0 - which means you
2055 * may not sleep between calling this and putting something into
2056 * the entry, as someone else might have used it while you slept.
2057 */
2058 static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
2059 struct inode *inode)
2060 {
2061 struct inode *dir = d_inode(dentry->d_parent);
2062 struct buffer_head *bh = NULL;
2063 struct ext4_dir_entry_2 *de;
2064 struct ext4_dir_entry_tail *t;
2065 struct super_block *sb;
2066 struct ext4_filename fname;
2067 int retval;
2068 int dx_fallback=0;
2069 unsigned blocksize;
2070 ext4_lblk_t block, blocks;
2071 int csum_size = 0;
2072
2073 if (ext4_has_metadata_csum(inode->i_sb))
2074 csum_size = sizeof(struct ext4_dir_entry_tail);
2075
2076 sb = dir->i_sb;
2077 blocksize = sb->s_blocksize;
2078 if (!dentry->d_name.len)
2079 return -EINVAL;
2080
2081 retval = ext4_fname_setup_filename(dir, &dentry->d_name, 0, &fname);
2082 if (retval)
2083 return retval;
2084
2085 if (ext4_has_inline_data(dir)) {
2086 retval = ext4_try_add_inline_entry(handle, &fname,
2087 dentry, inode);
2088 if (retval < 0)
2089 goto out;
2090 if (retval == 1) {
2091 retval = 0;
2092 goto out;
2093 }
2094 }
2095
2096 if (is_dx(dir)) {
2097 retval = ext4_dx_add_entry(handle, &fname, dentry, inode);
2098 if (!retval || (retval != ERR_BAD_DX_DIR))
2099 goto out;
2100 ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
2101 dx_fallback++;
2102 ext4_mark_inode_dirty(handle, dir);
2103 }
2104 blocks = dir->i_size >> sb->s_blocksize_bits;
2105 for (block = 0; block < blocks; block++) {
2106 bh = ext4_read_dirblock(dir, block, DIRENT);
2107 if (IS_ERR(bh)) {
2108 retval = PTR_ERR(bh);
2109 bh = NULL;
2110 goto out;
2111 }
2112 retval = add_dirent_to_buf(handle, &fname, dir, inode,
2113 NULL, bh);
2114 if (retval != -ENOSPC)
2115 goto out;
2116
2117 if (blocks == 1 && !dx_fallback &&
2118 ext4_has_feature_dir_index(sb)) {
2119 retval = make_indexed_dir(handle, &fname, dentry,
2120 inode, bh);
2121 bh = NULL; /* make_indexed_dir releases bh */
2122 goto out;
2123 }
2124 brelse(bh);
2125 }
2126 bh = ext4_append(handle, dir, &block);
2127 if (IS_ERR(bh)) {
2128 retval = PTR_ERR(bh);
2129 bh = NULL;
2130 goto out;
2131 }
2132 de = (struct ext4_dir_entry_2 *) bh->b_data;
2133 de->inode = 0;
2134 de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize);
2135
2136 if (csum_size) {
2137 t = EXT4_DIRENT_TAIL(bh->b_data, blocksize);
2138 initialize_dirent_tail(t, blocksize);
2139 }
2140
2141 retval = add_dirent_to_buf(handle, &fname, dir, inode, de, bh);
2142 out:
2143 ext4_fname_free_filename(&fname);
2144 brelse(bh);
2145 if (retval == 0)
2146 ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY);
2147 return retval;
2148 }
2149
2150 /*
2151 * Returns 0 for success, or a negative error value
2152 */
2153 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
2154 struct dentry *dentry, struct inode *inode)
2155 {
2156 struct dx_frame frames[2], *frame;
2157 struct dx_entry *entries, *at;
2158 struct buffer_head *bh;
2159 struct inode *dir = d_inode(dentry->d_parent);
2160 struct super_block *sb = dir->i_sb;
2161 struct ext4_dir_entry_2 *de;
2162 int err;
2163
2164 frame = dx_probe(fname, dir, NULL, frames);
2165 if (IS_ERR(frame))
2166 return PTR_ERR(frame);
2167 entries = frame->entries;
2168 at = frame->at;
2169 bh = ext4_read_dirblock(dir, dx_get_block(frame->at), DIRENT);
2170 if (IS_ERR(bh)) {
2171 err = PTR_ERR(bh);
2172 bh = NULL;
2173 goto cleanup;
2174 }
2175
2176 BUFFER_TRACE(bh, "get_write_access");
2177 err = ext4_journal_get_write_access(handle, bh);
2178 if (err)
2179 goto journal_error;
2180
2181 err = add_dirent_to_buf(handle, fname, dir, inode, NULL, bh);
2182 if (err != -ENOSPC)
2183 goto cleanup;
2184
2185 /* Block full, should compress but for now just split */
2186 dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
2187 dx_get_count(entries), dx_get_limit(entries)));
2188 /* Need to split index? */
2189 if (dx_get_count(entries) == dx_get_limit(entries)) {
2190 ext4_lblk_t newblock;
2191 unsigned icount = dx_get_count(entries);
2192 int levels = frame - frames;
2193 struct dx_entry *entries2;
2194 struct dx_node *node2;
2195 struct buffer_head *bh2;
2196
2197 if (levels && (dx_get_count(frames->entries) ==
2198 dx_get_limit(frames->entries))) {
2199 ext4_warning_inode(dir, "Directory index full!");
2200 err = -ENOSPC;
2201 goto cleanup;
2202 }
2203 bh2 = ext4_append(handle, dir, &newblock);
2204 if (IS_ERR(bh2)) {
2205 err = PTR_ERR(bh2);
2206 goto cleanup;
2207 }
2208 node2 = (struct dx_node *)(bh2->b_data);
2209 entries2 = node2->entries;
2210 memset(&node2->fake, 0, sizeof(struct fake_dirent));
2211 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
2212 sb->s_blocksize);
2213 BUFFER_TRACE(frame->bh, "get_write_access");
2214 err = ext4_journal_get_write_access(handle, frame->bh);
2215 if (err)
2216 goto journal_error;
2217 if (levels) {
2218 unsigned icount1 = icount/2, icount2 = icount - icount1;
2219 unsigned hash2 = dx_get_hash(entries + icount1);
2220 dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
2221 icount1, icount2));
2222
2223 BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
2224 err = ext4_journal_get_write_access(handle,
2225 frames[0].bh);
2226 if (err)
2227 goto journal_error;
2228
2229 memcpy((char *) entries2, (char *) (entries + icount1),
2230 icount2 * sizeof(struct dx_entry));
2231 dx_set_count(entries, icount1);
2232 dx_set_count(entries2, icount2);
2233 dx_set_limit(entries2, dx_node_limit(dir));
2234
2235 /* Which index block gets the new entry? */
2236 if (at - entries >= icount1) {
2237 frame->at = at = at - entries - icount1 + entries2;
2238 frame->entries = entries = entries2;
2239 swap(frame->bh, bh2);
2240 }
2241 dx_insert_block(frames + 0, hash2, newblock);
2242 dxtrace(dx_show_index("node", frames[1].entries));
2243 dxtrace(dx_show_index("node",
2244 ((struct dx_node *) bh2->b_data)->entries));
2245 err = ext4_handle_dirty_dx_node(handle, dir, bh2);
2246 if (err)
2247 goto journal_error;
2248 brelse (bh2);
2249 } else {
2250 dxtrace(printk(KERN_DEBUG
2251 "Creating second level index...\n"));
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 ((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels = 1;
2260
2261 /* Add new access path frame */
2262 frame = frames + 1;
2263 frame->at = at = at - entries + entries2;
2264 frame->entries = entries = entries2;
2265 frame->bh = bh2;
2266 err = ext4_journal_get_write_access(handle,
2267 frame->bh);
2268 if (err)
2269 goto journal_error;
2270 }
2271 err = ext4_handle_dirty_dx_node(handle, dir, frames[0].bh);
2272 if (err) {
2273 ext4_std_error(inode->i_sb, err);
2274 goto cleanup;
2275 }
2276 }
2277 de = do_split(handle, dir, &bh, frame, &fname->hinfo);
2278 if (IS_ERR(de)) {
2279 err = PTR_ERR(de);
2280 goto cleanup;
2281 }
2282 err = add_dirent_to_buf(handle, fname, dir, inode, de, bh);
2283 goto cleanup;
2284
2285 journal_error:
2286 ext4_std_error(dir->i_sb, err);
2287 cleanup:
2288 brelse(bh);
2289 dx_release(frames);
2290 return err;
2291 }
2292
2293 /*
2294 * ext4_generic_delete_entry deletes a directory entry by merging it
2295 * with the previous entry
2296 */
2297 int ext4_generic_delete_entry(handle_t *handle,
2298 struct inode *dir,
2299 struct ext4_dir_entry_2 *de_del,
2300 struct buffer_head *bh,
2301 void *entry_buf,
2302 int buf_size,
2303 int csum_size)
2304 {
2305 struct ext4_dir_entry_2 *de, *pde;
2306 unsigned int blocksize = dir->i_sb->s_blocksize;
2307 int i;
2308
2309 i = 0;
2310 pde = NULL;
2311 de = (struct ext4_dir_entry_2 *)entry_buf;
2312 while (i < buf_size - csum_size) {
2313 if (ext4_check_dir_entry(dir, NULL, de, bh,
2314 bh->b_data, bh->b_size, i))
2315 return -EFSCORRUPTED;
2316 if (de == de_del) {
2317 if (pde)
2318 pde->rec_len = ext4_rec_len_to_disk(
2319 ext4_rec_len_from_disk(pde->rec_len,
2320 blocksize) +
2321 ext4_rec_len_from_disk(de->rec_len,
2322 blocksize),
2323 blocksize);
2324 else
2325 de->inode = 0;
2326 dir->i_version++;
2327 return 0;
2328 }
2329 i += ext4_rec_len_from_disk(de->rec_len, blocksize);
2330 pde = de;
2331 de = ext4_next_entry(de, blocksize);
2332 }
2333 return -ENOENT;
2334 }
2335
2336 static int ext4_delete_entry(handle_t *handle,
2337 struct inode *dir,
2338 struct ext4_dir_entry_2 *de_del,
2339 struct buffer_head *bh)
2340 {
2341 int err, csum_size = 0;
2342
2343 if (ext4_has_inline_data(dir)) {
2344 int has_inline_data = 1;
2345 err = ext4_delete_inline_entry(handle, dir, de_del, bh,
2346 &has_inline_data);
2347 if (has_inline_data)
2348 return err;
2349 }
2350
2351 if (ext4_has_metadata_csum(dir->i_sb))
2352 csum_size = sizeof(struct ext4_dir_entry_tail);
2353
2354 BUFFER_TRACE(bh, "get_write_access");
2355 err = ext4_journal_get_write_access(handle, bh);
2356 if (unlikely(err))
2357 goto out;
2358
2359 err = ext4_generic_delete_entry(handle, dir, de_del,
2360 bh, bh->b_data,
2361 dir->i_sb->s_blocksize, csum_size);
2362 if (err)
2363 goto out;
2364
2365 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
2366 err = ext4_handle_dirty_dirent_node(handle, dir, bh);
2367 if (unlikely(err))
2368 goto out;
2369
2370 return 0;
2371 out:
2372 if (err != -ENOENT)
2373 ext4_std_error(dir->i_sb, err);
2374 return err;
2375 }
2376
2377 /*
2378 * DIR_NLINK feature is set if 1) nlinks > EXT4_LINK_MAX or 2) nlinks == 2,
2379 * since this indicates that nlinks count was previously 1.
2380 */
2381 static void ext4_inc_count(handle_t *handle, struct inode *inode)
2382 {
2383 inc_nlink(inode);
2384 if (is_dx(inode) && inode->i_nlink > 1) {
2385 /* limit is 16-bit i_links_count */
2386 if (inode->i_nlink >= EXT4_LINK_MAX || inode->i_nlink == 2) {
2387 set_nlink(inode, 1);
2388 ext4_set_feature_dir_nlink(inode->i_sb);
2389 }
2390 }
2391 }
2392
2393 /*
2394 * If a directory had nlink == 1, then we should let it be 1. This indicates
2395 * directory has >EXT4_LINK_MAX subdirs.
2396 */
2397 static void ext4_dec_count(handle_t *handle, struct inode *inode)
2398 {
2399 if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
2400 drop_nlink(inode);
2401 }
2402
2403
2404 static int ext4_add_nondir(handle_t *handle,
2405 struct dentry *dentry, struct inode *inode)
2406 {
2407 int err = ext4_add_entry(handle, dentry, inode);
2408 if (!err) {
2409 ext4_mark_inode_dirty(handle, inode);
2410 unlock_new_inode(inode);
2411 d_instantiate(dentry, inode);
2412 return 0;
2413 }
2414 drop_nlink(inode);
2415 unlock_new_inode(inode);
2416 iput(inode);
2417 return err;
2418 }
2419
2420 /*
2421 * By the time this is called, we already have created
2422 * the directory cache entry for the new file, but it
2423 * is so far negative - it has no inode.
2424 *
2425 * If the create succeeds, we fill in the inode information
2426 * with d_instantiate().
2427 */
2428 static int ext4_create(struct inode *dir, struct dentry *dentry, umode_t mode,
2429 bool excl)
2430 {
2431 handle_t *handle;
2432 struct inode *inode;
2433 int err, credits, retries = 0;
2434
2435 err = dquot_initialize(dir);
2436 if (err)
2437 return err;
2438
2439 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2440 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2441 retry:
2442 inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
2443 NULL, EXT4_HT_DIR, credits);
2444 handle = ext4_journal_current_handle();
2445 err = PTR_ERR(inode);
2446 if (!IS_ERR(inode)) {
2447 inode->i_op = &ext4_file_inode_operations;
2448 inode->i_fop = &ext4_file_operations;
2449 ext4_set_aops(inode);
2450 err = ext4_add_nondir(handle, dentry, inode);
2451 if (!err && IS_DIRSYNC(dir))
2452 ext4_handle_sync(handle);
2453 }
2454 if (handle)
2455 ext4_journal_stop(handle);
2456 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2457 goto retry;
2458 return err;
2459 }
2460
2461 static int ext4_mknod(struct inode *dir, struct dentry *dentry,
2462 umode_t mode, dev_t rdev)
2463 {
2464 handle_t *handle;
2465 struct inode *inode;
2466 int err, credits, retries = 0;
2467
2468 err = dquot_initialize(dir);
2469 if (err)
2470 return err;
2471
2472 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2473 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2474 retry:
2475 inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
2476 NULL, EXT4_HT_DIR, credits);
2477 handle = ext4_journal_current_handle();
2478 err = PTR_ERR(inode);
2479 if (!IS_ERR(inode)) {
2480 init_special_inode(inode, inode->i_mode, rdev);
2481 inode->i_op = &ext4_special_inode_operations;
2482 err = ext4_add_nondir(handle, dentry, inode);
2483 if (!err && IS_DIRSYNC(dir))
2484 ext4_handle_sync(handle);
2485 }
2486 if (handle)
2487 ext4_journal_stop(handle);
2488 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2489 goto retry;
2490 return err;
2491 }
2492
2493 static int ext4_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
2494 {
2495 handle_t *handle;
2496 struct inode *inode;
2497 int err, retries = 0;
2498
2499 err = dquot_initialize(dir);
2500 if (err)
2501 return err;
2502
2503 retry:
2504 inode = ext4_new_inode_start_handle(dir, mode,
2505 NULL, 0, NULL,
2506 EXT4_HT_DIR,
2507 EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
2508 4 + EXT4_XATTR_TRANS_BLOCKS);
2509 handle = ext4_journal_current_handle();
2510 err = PTR_ERR(inode);
2511 if (!IS_ERR(inode)) {
2512 inode->i_op = &ext4_file_inode_operations;
2513 inode->i_fop = &ext4_file_operations;
2514 ext4_set_aops(inode);
2515 d_tmpfile(dentry, inode);
2516 err = ext4_orphan_add(handle, inode);
2517 if (err)
2518 goto err_unlock_inode;
2519 mark_inode_dirty(inode);
2520 unlock_new_inode(inode);
2521 }
2522 if (handle)
2523 ext4_journal_stop(handle);
2524 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2525 goto retry;
2526 return err;
2527 err_unlock_inode:
2528 ext4_journal_stop(handle);
2529 unlock_new_inode(inode);
2530 return err;
2531 }
2532
2533 struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
2534 struct ext4_dir_entry_2 *de,
2535 int blocksize, int csum_size,
2536 unsigned int parent_ino, int dotdot_real_len)
2537 {
2538 de->inode = cpu_to_le32(inode->i_ino);
2539 de->name_len = 1;
2540 de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
2541 blocksize);
2542 strcpy(de->name, ".");
2543 ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2544
2545 de = ext4_next_entry(de, blocksize);
2546 de->inode = cpu_to_le32(parent_ino);
2547 de->name_len = 2;
2548 if (!dotdot_real_len)
2549 de->rec_len = ext4_rec_len_to_disk(blocksize -
2550 (csum_size + EXT4_DIR_REC_LEN(1)),
2551 blocksize);
2552 else
2553 de->rec_len = ext4_rec_len_to_disk(
2554 EXT4_DIR_REC_LEN(de->name_len), blocksize);
2555 strcpy(de->name, "..");
2556 ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2557
2558 return ext4_next_entry(de, blocksize);
2559 }
2560
2561 static int ext4_init_new_dir(handle_t *handle, struct inode *dir,
2562 struct inode *inode)
2563 {
2564 struct buffer_head *dir_block = NULL;
2565 struct ext4_dir_entry_2 *de;
2566 struct ext4_dir_entry_tail *t;
2567 ext4_lblk_t block = 0;
2568 unsigned int blocksize = dir->i_sb->s_blocksize;
2569 int csum_size = 0;
2570 int err;
2571
2572 if (ext4_has_metadata_csum(dir->i_sb))
2573 csum_size = sizeof(struct ext4_dir_entry_tail);
2574
2575 if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
2576 err = ext4_try_create_inline_dir(handle, dir, inode);
2577 if (err < 0 && err != -ENOSPC)
2578 goto out;
2579 if (!err)
2580 goto out;
2581 }
2582
2583 inode->i_size = 0;
2584 dir_block = ext4_append(handle, inode, &block);
2585 if (IS_ERR(dir_block))
2586 return PTR_ERR(dir_block);
2587 de = (struct ext4_dir_entry_2 *)dir_block->b_data;
2588 ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0);
2589 set_nlink(inode, 2);
2590 if (csum_size) {
2591 t = EXT4_DIRENT_TAIL(dir_block->b_data, blocksize);
2592 initialize_dirent_tail(t, blocksize);
2593 }
2594
2595 BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
2596 err = ext4_handle_dirty_dirent_node(handle, inode, dir_block);
2597 if (err)
2598 goto out;
2599 set_buffer_verified(dir_block);
2600 out:
2601 brelse(dir_block);
2602 return err;
2603 }
2604
2605 static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
2606 {
2607 handle_t *handle;
2608 struct inode *inode;
2609 int err, credits, retries = 0;
2610
2611 if (EXT4_DIR_LINK_MAX(dir))
2612 return -EMLINK;
2613
2614 err = dquot_initialize(dir);
2615 if (err)
2616 return err;
2617
2618 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2619 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2620 retry:
2621 inode = ext4_new_inode_start_handle(dir, S_IFDIR | mode,
2622 &dentry->d_name,
2623 0, NULL, EXT4_HT_DIR, credits);
2624 handle = ext4_journal_current_handle();
2625 err = PTR_ERR(inode);
2626 if (IS_ERR(inode))
2627 goto out_stop;
2628
2629 inode->i_op = &ext4_dir_inode_operations;
2630 inode->i_fop = &ext4_dir_operations;
2631 err = ext4_init_new_dir(handle, dir, inode);
2632 if (err)
2633 goto out_clear_inode;
2634 err = ext4_mark_inode_dirty(handle, inode);
2635 if (!err)
2636 err = ext4_add_entry(handle, dentry, inode);
2637 if (err) {
2638 out_clear_inode:
2639 clear_nlink(inode);
2640 unlock_new_inode(inode);
2641 ext4_mark_inode_dirty(handle, inode);
2642 iput(inode);
2643 goto out_stop;
2644 }
2645 ext4_inc_count(handle, dir);
2646 ext4_update_dx_flag(dir);
2647 err = ext4_mark_inode_dirty(handle, dir);
2648 if (err)
2649 goto out_clear_inode;
2650 unlock_new_inode(inode);
2651 d_instantiate(dentry, inode);
2652 if (IS_DIRSYNC(dir))
2653 ext4_handle_sync(handle);
2654
2655 out_stop:
2656 if (handle)
2657 ext4_journal_stop(handle);
2658 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2659 goto retry;
2660 return err;
2661 }
2662
2663 /*
2664 * routine to check that the specified directory is empty (for rmdir)
2665 */
2666 int ext4_empty_dir(struct inode *inode)
2667 {
2668 unsigned int offset;
2669 struct buffer_head *bh;
2670 struct ext4_dir_entry_2 *de, *de1;
2671 struct super_block *sb;
2672 int err = 0;
2673
2674 if (ext4_has_inline_data(inode)) {
2675 int has_inline_data = 1;
2676
2677 err = empty_inline_dir(inode, &has_inline_data);
2678 if (has_inline_data)
2679 return err;
2680 }
2681
2682 sb = inode->i_sb;
2683 if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2)) {
2684 EXT4_ERROR_INODE(inode, "invalid size");
2685 return 1;
2686 }
2687 bh = ext4_read_dirblock(inode, 0, EITHER);
2688 if (IS_ERR(bh))
2689 return 1;
2690
2691 de = (struct ext4_dir_entry_2 *) bh->b_data;
2692 de1 = ext4_next_entry(de, sb->s_blocksize);
2693 if (le32_to_cpu(de->inode) != inode->i_ino ||
2694 le32_to_cpu(de1->inode) == 0 ||
2695 strcmp(".", de->name) || strcmp("..", de1->name)) {
2696 ext4_warning_inode(inode, "directory missing '.' and/or '..'");
2697 brelse(bh);
2698 return 1;
2699 }
2700 offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) +
2701 ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize);
2702 de = ext4_next_entry(de1, sb->s_blocksize);
2703 while (offset < inode->i_size) {
2704 if ((void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
2705 unsigned int lblock;
2706 err = 0;
2707 brelse(bh);
2708 lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb);
2709 bh = ext4_read_dirblock(inode, lblock, EITHER);
2710 if (IS_ERR(bh))
2711 return 1;
2712 de = (struct ext4_dir_entry_2 *) bh->b_data;
2713 }
2714 if (ext4_check_dir_entry(inode, NULL, de, bh,
2715 bh->b_data, bh->b_size, offset)) {
2716 de = (struct ext4_dir_entry_2 *)(bh->b_data +
2717 sb->s_blocksize);
2718 offset = (offset | (sb->s_blocksize - 1)) + 1;
2719 continue;
2720 }
2721 if (le32_to_cpu(de->inode)) {
2722 brelse(bh);
2723 return 0;
2724 }
2725 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
2726 de = ext4_next_entry(de, sb->s_blocksize);
2727 }
2728 brelse(bh);
2729 return 1;
2730 }
2731
2732 /*
2733 * ext4_orphan_add() links an unlinked or truncated inode into a list of
2734 * such inodes, starting at the superblock, in case we crash before the
2735 * file is closed/deleted, or in case the inode truncate spans multiple
2736 * transactions and the last transaction is not recovered after a crash.
2737 *
2738 * At filesystem recovery time, we walk this list deleting unlinked
2739 * inodes and truncating linked inodes in ext4_orphan_cleanup().
2740 *
2741 * Orphan list manipulation functions must be called under i_mutex unless
2742 * we are just creating the inode or deleting it.
2743 */
2744 int ext4_orphan_add(handle_t *handle, struct inode *inode)
2745 {
2746 struct super_block *sb = inode->i_sb;
2747 struct ext4_sb_info *sbi = EXT4_SB(sb);
2748 struct ext4_iloc iloc;
2749 int err = 0, rc;
2750 bool dirty = false;
2751
2752 if (!sbi->s_journal || is_bad_inode(inode))
2753 return 0;
2754
2755 WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
2756 !mutex_is_locked(&inode->i_mutex));
2757 /*
2758 * Exit early if inode already is on orphan list. This is a big speedup
2759 * since we don't have to contend on the global s_orphan_lock.
2760 */
2761 if (!list_empty(&EXT4_I(inode)->i_orphan))
2762 return 0;
2763
2764 /*
2765 * Orphan handling is only valid for files with data blocks
2766 * being truncated, or files being unlinked. Note that we either
2767 * hold i_mutex, or the inode can not be referenced from outside,
2768 * so i_nlink should not be bumped due to race
2769 */
2770 J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2771 S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
2772
2773 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2774 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2775 if (err)
2776 goto out;
2777
2778 err = ext4_reserve_inode_write(handle, inode, &iloc);
2779 if (err)
2780 goto out;
2781
2782 mutex_lock(&sbi->s_orphan_lock);
2783 /*
2784 * Due to previous errors inode may be already a part of on-disk
2785 * orphan list. If so skip on-disk list modification.
2786 */
2787 if (!NEXT_ORPHAN(inode) || NEXT_ORPHAN(inode) >
2788 (le32_to_cpu(sbi->s_es->s_inodes_count))) {
2789 /* Insert this inode at the head of the on-disk orphan list */
2790 NEXT_ORPHAN(inode) = le32_to_cpu(sbi->s_es->s_last_orphan);
2791 sbi->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
2792 dirty = true;
2793 }
2794 list_add(&EXT4_I(inode)->i_orphan, &sbi->s_orphan);
2795 mutex_unlock(&sbi->s_orphan_lock);
2796
2797 if (dirty) {
2798 err = ext4_handle_dirty_super(handle, sb);
2799 rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
2800 if (!err)
2801 err = rc;
2802 if (err) {
2803 /*
2804 * We have to remove inode from in-memory list if
2805 * addition to on disk orphan list failed. Stray orphan
2806 * list entries can cause panics at unmount time.
2807 */
2808 mutex_lock(&sbi->s_orphan_lock);
2809 list_del_init(&EXT4_I(inode)->i_orphan);
2810 mutex_unlock(&sbi->s_orphan_lock);
2811 }
2812 }
2813 jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
2814 jbd_debug(4, "orphan inode %lu will point to %d\n",
2815 inode->i_ino, NEXT_ORPHAN(inode));
2816 out:
2817 ext4_std_error(sb, err);
2818 return err;
2819 }
2820
2821 /*
2822 * ext4_orphan_del() removes an unlinked or truncated inode from the list
2823 * of such inodes stored on disk, because it is finally being cleaned up.
2824 */
2825 int ext4_orphan_del(handle_t *handle, struct inode *inode)
2826 {
2827 struct list_head *prev;
2828 struct ext4_inode_info *ei = EXT4_I(inode);
2829 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2830 __u32 ino_next;
2831 struct ext4_iloc iloc;
2832 int err = 0;
2833
2834 if (!sbi->s_journal && !(sbi->s_mount_state & EXT4_ORPHAN_FS))
2835 return 0;
2836
2837 WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
2838 !mutex_is_locked(&inode->i_mutex));
2839 /* Do this quick check before taking global s_orphan_lock. */
2840 if (list_empty(&ei->i_orphan))
2841 return 0;
2842
2843 if (handle) {
2844 /* Grab inode buffer early before taking global s_orphan_lock */
2845 err = ext4_reserve_inode_write(handle, inode, &iloc);
2846 }
2847
2848 mutex_lock(&sbi->s_orphan_lock);
2849 jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
2850
2851 prev = ei->i_orphan.prev;
2852 list_del_init(&ei->i_orphan);
2853
2854 /* If we're on an error path, we may not have a valid
2855 * transaction handle with which to update the orphan list on
2856 * disk, but we still need to remove the inode from the linked
2857 * list in memory. */
2858 if (!handle || err) {
2859 mutex_unlock(&sbi->s_orphan_lock);
2860 goto out_err;
2861 }
2862
2863 ino_next = NEXT_ORPHAN(inode);
2864 if (prev == &sbi->s_orphan) {
2865 jbd_debug(4, "superblock will point to %u\n", ino_next);
2866 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2867 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2868 if (err) {
2869 mutex_unlock(&sbi->s_orphan_lock);
2870 goto out_brelse;
2871 }
2872 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
2873 mutex_unlock(&sbi->s_orphan_lock);
2874 err = ext4_handle_dirty_super(handle, inode->i_sb);
2875 } else {
2876 struct ext4_iloc iloc2;
2877 struct inode *i_prev =
2878 &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
2879
2880 jbd_debug(4, "orphan inode %lu will point to %u\n",
2881 i_prev->i_ino, ino_next);
2882 err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
2883 if (err) {
2884 mutex_unlock(&sbi->s_orphan_lock);
2885 goto out_brelse;
2886 }
2887 NEXT_ORPHAN(i_prev) = ino_next;
2888 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
2889 mutex_unlock(&sbi->s_orphan_lock);
2890 }
2891 if (err)
2892 goto out_brelse;
2893 NEXT_ORPHAN(inode) = 0;
2894 err = ext4_mark_iloc_dirty(handle, inode, &iloc);
2895 out_err:
2896 ext4_std_error(inode->i_sb, err);
2897 return err;
2898
2899 out_brelse:
2900 brelse(iloc.bh);
2901 goto out_err;
2902 }
2903
2904 static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
2905 {
2906 int retval;
2907 struct inode *inode;
2908 struct buffer_head *bh;
2909 struct ext4_dir_entry_2 *de;
2910 handle_t *handle = NULL;
2911
2912 /* Initialize quotas before so that eventual writes go in
2913 * separate transaction */
2914 retval = dquot_initialize(dir);
2915 if (retval)
2916 return retval;
2917 retval = dquot_initialize(d_inode(dentry));
2918 if (retval)
2919 return retval;
2920
2921 retval = -ENOENT;
2922 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
2923 if (IS_ERR(bh))
2924 return PTR_ERR(bh);
2925 if (!bh)
2926 goto end_rmdir;
2927
2928 inode = d_inode(dentry);
2929
2930 retval = -EFSCORRUPTED;
2931 if (le32_to_cpu(de->inode) != inode->i_ino)
2932 goto end_rmdir;
2933
2934 retval = -ENOTEMPTY;
2935 if (!ext4_empty_dir(inode))
2936 goto end_rmdir;
2937
2938 handle = ext4_journal_start(dir, EXT4_HT_DIR,
2939 EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
2940 if (IS_ERR(handle)) {
2941 retval = PTR_ERR(handle);
2942 handle = NULL;
2943 goto end_rmdir;
2944 }
2945
2946 if (IS_DIRSYNC(dir))
2947 ext4_handle_sync(handle);
2948
2949 retval = ext4_delete_entry(handle, dir, de, bh);
2950 if (retval)
2951 goto end_rmdir;
2952 if (!EXT4_DIR_LINK_EMPTY(inode))
2953 ext4_warning_inode(inode,
2954 "empty directory '%.*s' has too many links (%u)",
2955 dentry->d_name.len, dentry->d_name.name,
2956 inode->i_nlink);
2957 inode->i_version++;
2958 clear_nlink(inode);
2959 /* There's no need to set i_disksize: the fact that i_nlink is
2960 * zero will ensure that the right thing happens during any
2961 * recovery. */
2962 inode->i_size = 0;
2963 ext4_orphan_add(handle, inode);
2964 inode->i_ctime = dir->i_ctime = dir->i_mtime = ext4_current_time(inode);
2965 ext4_mark_inode_dirty(handle, inode);
2966 ext4_dec_count(handle, dir);
2967 ext4_update_dx_flag(dir);
2968 ext4_mark_inode_dirty(handle, dir);
2969
2970 end_rmdir:
2971 brelse(bh);
2972 if (handle)
2973 ext4_journal_stop(handle);
2974 return retval;
2975 }
2976
2977 static int ext4_unlink(struct inode *dir, struct dentry *dentry)
2978 {
2979 int retval;
2980 struct inode *inode;
2981 struct buffer_head *bh;
2982 struct ext4_dir_entry_2 *de;
2983 handle_t *handle = NULL;
2984
2985 trace_ext4_unlink_enter(dir, dentry);
2986 /* Initialize quotas before so that eventual writes go
2987 * in separate transaction */
2988 retval = dquot_initialize(dir);
2989 if (retval)
2990 return retval;
2991 retval = dquot_initialize(d_inode(dentry));
2992 if (retval)
2993 return retval;
2994
2995 retval = -ENOENT;
2996 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
2997 if (IS_ERR(bh))
2998 return PTR_ERR(bh);
2999 if (!bh)
3000 goto end_unlink;
3001
3002 inode = d_inode(dentry);
3003
3004 retval = -EFSCORRUPTED;
3005 if (le32_to_cpu(de->inode) != inode->i_ino)
3006 goto end_unlink;
3007
3008 handle = ext4_journal_start(dir, EXT4_HT_DIR,
3009 EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
3010 if (IS_ERR(handle)) {
3011 retval = PTR_ERR(handle);
3012 handle = NULL;
3013 goto end_unlink;
3014 }
3015
3016 if (IS_DIRSYNC(dir))
3017 ext4_handle_sync(handle);
3018
3019 if (inode->i_nlink == 0) {
3020 ext4_warning_inode(inode, "Deleting file '%.*s' with no links",
3021 dentry->d_name.len, dentry->d_name.name);
3022 set_nlink(inode, 1);
3023 }
3024 retval = ext4_delete_entry(handle, dir, de, bh);
3025 if (retval)
3026 goto end_unlink;
3027 dir->i_ctime = dir->i_mtime = ext4_current_time(dir);
3028 ext4_update_dx_flag(dir);
3029 ext4_mark_inode_dirty(handle, dir);
3030 drop_nlink(inode);
3031 if (!inode->i_nlink)
3032 ext4_orphan_add(handle, inode);
3033 inode->i_ctime = ext4_current_time(inode);
3034 ext4_mark_inode_dirty(handle, inode);
3035
3036 end_unlink:
3037 brelse(bh);
3038 if (handle)
3039 ext4_journal_stop(handle);
3040 trace_ext4_unlink_exit(dentry, retval);
3041 return retval;
3042 }
3043
3044 static int ext4_symlink(struct inode *dir,
3045 struct dentry *dentry, const char *symname)
3046 {
3047 handle_t *handle;
3048 struct inode *inode;
3049 int err, len = strlen(symname);
3050 int credits;
3051 bool encryption_required;
3052 struct ext4_str disk_link;
3053 struct ext4_encrypted_symlink_data *sd = NULL;
3054
3055 disk_link.len = len + 1;
3056 disk_link.name = (char *) symname;
3057
3058 encryption_required = (ext4_encrypted_inode(dir) ||
3059 DUMMY_ENCRYPTION_ENABLED(EXT4_SB(dir->i_sb)));
3060 if (encryption_required) {
3061 err = ext4_get_encryption_info(dir);
3062 if (err)
3063 return err;
3064 if (ext4_encryption_info(dir) == NULL)
3065 return -EPERM;
3066 disk_link.len = (ext4_fname_encrypted_size(dir, len) +
3067 sizeof(struct ext4_encrypted_symlink_data));
3068 sd = kzalloc(disk_link.len, GFP_KERNEL);
3069 if (!sd)
3070 return -ENOMEM;
3071 }
3072
3073 if (disk_link.len > dir->i_sb->s_blocksize) {
3074 err = -ENAMETOOLONG;
3075 goto err_free_sd;
3076 }
3077
3078 err = dquot_initialize(dir);
3079 if (err)
3080 goto err_free_sd;
3081
3082 if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
3083 /*
3084 * For non-fast symlinks, we just allocate inode and put it on
3085 * orphan list in the first transaction => we need bitmap,
3086 * group descriptor, sb, inode block, quota blocks, and
3087 * possibly selinux xattr blocks.
3088 */
3089 credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
3090 EXT4_XATTR_TRANS_BLOCKS;
3091 } else {
3092 /*
3093 * Fast symlink. We have to add entry to directory
3094 * (EXT4_DATA_TRANS_BLOCKS + EXT4_INDEX_EXTRA_TRANS_BLOCKS),
3095 * allocate new inode (bitmap, group descriptor, inode block,
3096 * quota blocks, sb is already counted in previous macros).
3097 */
3098 credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3099 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3;
3100 }
3101
3102 inode = ext4_new_inode_start_handle(dir, S_IFLNK|S_IRWXUGO,
3103 &dentry->d_name, 0, NULL,
3104 EXT4_HT_DIR, credits);
3105 handle = ext4_journal_current_handle();
3106 if (IS_ERR(inode)) {
3107 if (handle)
3108 ext4_journal_stop(handle);
3109 err = PTR_ERR(inode);
3110 goto err_free_sd;
3111 }
3112
3113 if (encryption_required) {
3114 struct qstr istr;
3115 struct ext4_str ostr;
3116
3117 istr.name = (const unsigned char *) symname;
3118 istr.len = len;
3119 ostr.name = sd->encrypted_path;
3120 ostr.len = disk_link.len;
3121 err = ext4_fname_usr_to_disk(inode, &istr, &ostr);
3122 if (err < 0)
3123 goto err_drop_inode;
3124 sd->len = cpu_to_le16(ostr.len);
3125 disk_link.name = (char *) sd;
3126 inode->i_op = &ext4_encrypted_symlink_inode_operations;
3127 }
3128
3129 if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
3130 if (!encryption_required)
3131 inode->i_op = &ext4_symlink_inode_operations;
3132 ext4_set_aops(inode);
3133 /*
3134 * We cannot call page_symlink() with transaction started
3135 * because it calls into ext4_write_begin() which can wait
3136 * for transaction commit if we are running out of space
3137 * and thus we deadlock. So we have to stop transaction now
3138 * and restart it when symlink contents is written.
3139 *
3140 * To keep fs consistent in case of crash, we have to put inode
3141 * to orphan list in the mean time.
3142 */
3143 drop_nlink(inode);
3144 err = ext4_orphan_add(handle, inode);
3145 ext4_journal_stop(handle);
3146 handle = NULL;
3147 if (err)
3148 goto err_drop_inode;
3149 err = __page_symlink(inode, disk_link.name, disk_link.len, 1);
3150 if (err)
3151 goto err_drop_inode;
3152 /*
3153 * Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS
3154 * + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified
3155 */
3156 handle = ext4_journal_start(dir, EXT4_HT_DIR,
3157 EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3158 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1);
3159 if (IS_ERR(handle)) {
3160 err = PTR_ERR(handle);
3161 handle = NULL;
3162 goto err_drop_inode;
3163 }
3164 set_nlink(inode, 1);
3165 err = ext4_orphan_del(handle, inode);
3166 if (err)
3167 goto err_drop_inode;
3168 } else {
3169 /* clear the extent format for fast symlink */
3170 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
3171 if (!encryption_required) {
3172 inode->i_op = &ext4_fast_symlink_inode_operations;
3173 inode->i_link = (char *)&EXT4_I(inode)->i_data;
3174 }
3175 memcpy((char *)&EXT4_I(inode)->i_data, disk_link.name,
3176 disk_link.len);
3177 inode->i_size = disk_link.len - 1;
3178 }
3179 EXT4_I(inode)->i_disksize = inode->i_size;
3180 err = ext4_add_nondir(handle, dentry, inode);
3181 if (!err && IS_DIRSYNC(dir))
3182 ext4_handle_sync(handle);
3183
3184 if (handle)
3185 ext4_journal_stop(handle);
3186 kfree(sd);
3187 return err;
3188 err_drop_inode:
3189 if (handle)
3190 ext4_journal_stop(handle);
3191 clear_nlink(inode);
3192 unlock_new_inode(inode);
3193 iput(inode);
3194 err_free_sd:
3195 kfree(sd);
3196 return err;
3197 }
3198
3199 static int ext4_link(struct dentry *old_dentry,
3200 struct inode *dir, struct dentry *dentry)
3201 {
3202 handle_t *handle;
3203 struct inode *inode = d_inode(old_dentry);
3204 int err, retries = 0;
3205
3206 if (inode->i_nlink >= EXT4_LINK_MAX)
3207 return -EMLINK;
3208 if (ext4_encrypted_inode(dir) &&
3209 !ext4_is_child_context_consistent_with_parent(dir, inode))
3210 return -EPERM;
3211 err = dquot_initialize(dir);
3212 if (err)
3213 return err;
3214
3215 retry:
3216 handle = ext4_journal_start(dir, EXT4_HT_DIR,
3217 (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3218 EXT4_INDEX_EXTRA_TRANS_BLOCKS) + 1);
3219 if (IS_ERR(handle))
3220 return PTR_ERR(handle);
3221
3222 if (IS_DIRSYNC(dir))
3223 ext4_handle_sync(handle);
3224
3225 inode->i_ctime = ext4_current_time(inode);
3226 ext4_inc_count(handle, inode);
3227 ihold(inode);
3228
3229 err = ext4_add_entry(handle, dentry, inode);
3230 if (!err) {
3231 ext4_mark_inode_dirty(handle, inode);
3232 /* this can happen only for tmpfile being
3233 * linked the first time
3234 */
3235 if (inode->i_nlink == 1)
3236 ext4_orphan_del(handle, inode);
3237 d_instantiate(dentry, inode);
3238 } else {
3239 drop_nlink(inode);
3240 iput(inode);
3241 }
3242 ext4_journal_stop(handle);
3243 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
3244 goto retry;
3245 return err;
3246 }
3247
3248
3249 /*
3250 * Try to find buffer head where contains the parent block.
3251 * It should be the inode block if it is inlined or the 1st block
3252 * if it is a normal dir.
3253 */
3254 static struct buffer_head *ext4_get_first_dir_block(handle_t *handle,
3255 struct inode *inode,
3256 int *retval,
3257 struct ext4_dir_entry_2 **parent_de,
3258 int *inlined)
3259 {
3260 struct buffer_head *bh;
3261
3262 if (!ext4_has_inline_data(inode)) {
3263 bh = ext4_read_dirblock(inode, 0, EITHER);
3264 if (IS_ERR(bh)) {
3265 *retval = PTR_ERR(bh);
3266 return NULL;
3267 }
3268 *parent_de = ext4_next_entry(
3269 (struct ext4_dir_entry_2 *)bh->b_data,
3270 inode->i_sb->s_blocksize);
3271 return bh;
3272 }
3273
3274 *inlined = 1;
3275 return ext4_get_first_inline_block(inode, parent_de, retval);
3276 }
3277
3278 struct ext4_renament {
3279 struct inode *dir;
3280 struct dentry *dentry;
3281 struct inode *inode;
3282 bool is_dir;
3283 int dir_nlink_delta;
3284
3285 /* entry for "dentry" */
3286 struct buffer_head *bh;
3287 struct ext4_dir_entry_2 *de;
3288 int inlined;
3289
3290 /* entry for ".." in inode if it's a directory */
3291 struct buffer_head *dir_bh;
3292 struct ext4_dir_entry_2 *parent_de;
3293 int dir_inlined;
3294 };
3295
3296 static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent)
3297 {
3298 int retval;
3299
3300 ent->dir_bh = ext4_get_first_dir_block(handle, ent->inode,
3301 &retval, &ent->parent_de,
3302 &ent->dir_inlined);
3303 if (!ent->dir_bh)
3304 return retval;
3305 if (le32_to_cpu(ent->parent_de->inode) != ent->dir->i_ino)
3306 return -EFSCORRUPTED;
3307 BUFFER_TRACE(ent->dir_bh, "get_write_access");
3308 return ext4_journal_get_write_access(handle, ent->dir_bh);
3309 }
3310
3311 static int ext4_rename_dir_finish(handle_t *handle, struct ext4_renament *ent,
3312 unsigned dir_ino)
3313 {
3314 int retval;
3315
3316 ent->parent_de->inode = cpu_to_le32(dir_ino);
3317 BUFFER_TRACE(ent->dir_bh, "call ext4_handle_dirty_metadata");
3318 if (!ent->dir_inlined) {
3319 if (is_dx(ent->inode)) {
3320 retval = ext4_handle_dirty_dx_node(handle,
3321 ent->inode,
3322 ent->dir_bh);
3323 } else {
3324 retval = ext4_handle_dirty_dirent_node(handle,
3325 ent->inode,
3326 ent->dir_bh);
3327 }
3328 } else {
3329 retval = ext4_mark_inode_dirty(handle, ent->inode);
3330 }
3331 if (retval) {
3332 ext4_std_error(ent->dir->i_sb, retval);
3333 return retval;
3334 }
3335 return 0;
3336 }
3337
3338 static int ext4_setent(handle_t *handle, struct ext4_renament *ent,
3339 unsigned ino, unsigned file_type)
3340 {
3341 int retval;
3342
3343 BUFFER_TRACE(ent->bh, "get write access");
3344 retval = ext4_journal_get_write_access(handle, ent->bh);
3345 if (retval)
3346 return retval;
3347 ent->de->inode = cpu_to_le32(ino);
3348 if (ext4_has_feature_filetype(ent->dir->i_sb))
3349 ent->de->file_type = file_type;
3350 ent->dir->i_version++;
3351 ent->dir->i_ctime = ent->dir->i_mtime =
3352 ext4_current_time(ent->dir);
3353 ext4_mark_inode_dirty(handle, ent->dir);
3354 BUFFER_TRACE(ent->bh, "call ext4_handle_dirty_metadata");
3355 if (!ent->inlined) {
3356 retval = ext4_handle_dirty_dirent_node(handle,
3357 ent->dir, ent->bh);
3358 if (unlikely(retval)) {
3359 ext4_std_error(ent->dir->i_sb, retval);
3360 return retval;
3361 }
3362 }
3363 brelse(ent->bh);
3364 ent->bh = NULL;
3365
3366 return 0;
3367 }
3368
3369 static int ext4_find_delete_entry(handle_t *handle, struct inode *dir,
3370 const struct qstr *d_name)
3371 {
3372 int retval = -ENOENT;
3373 struct buffer_head *bh;
3374 struct ext4_dir_entry_2 *de;
3375
3376 bh = ext4_find_entry(dir, d_name, &de, NULL);
3377 if (IS_ERR(bh))
3378 return PTR_ERR(bh);
3379 if (bh) {
3380 retval = ext4_delete_entry(handle, dir, de, bh);
3381 brelse(bh);
3382 }
3383 return retval;
3384 }
3385
3386 static void ext4_rename_delete(handle_t *handle, struct ext4_renament *ent,
3387 int force_reread)
3388 {
3389 int retval;
3390 /*
3391 * ent->de could have moved from under us during htree split, so make
3392 * sure that we are deleting the right entry. We might also be pointing
3393 * to a stale entry in the unused part of ent->bh so just checking inum
3394 * and the name isn't enough.
3395 */
3396 if (le32_to_cpu(ent->de->inode) != ent->inode->i_ino ||
3397 ent->de->name_len != ent->dentry->d_name.len ||
3398 strncmp(ent->de->name, ent->dentry->d_name.name,
3399 ent->de->name_len) ||
3400 force_reread) {
3401 retval = ext4_find_delete_entry(handle, ent->dir,
3402 &ent->dentry->d_name);
3403 } else {
3404 retval = ext4_delete_entry(handle, ent->dir, ent->de, ent->bh);
3405 if (retval == -ENOENT) {
3406 retval = ext4_find_delete_entry(handle, ent->dir,
3407 &ent->dentry->d_name);
3408 }
3409 }
3410
3411 if (retval) {
3412 ext4_warning_inode(ent->dir,
3413 "Deleting old file: nlink %d, error=%d",
3414 ent->dir->i_nlink, retval);
3415 }
3416 }
3417
3418 static void ext4_update_dir_count(handle_t *handle, struct ext4_renament *ent)
3419 {
3420 if (ent->dir_nlink_delta) {
3421 if (ent->dir_nlink_delta == -1)
3422 ext4_dec_count(handle, ent->dir);
3423 else
3424 ext4_inc_count(handle, ent->dir);
3425 ext4_mark_inode_dirty(handle, ent->dir);
3426 }
3427 }
3428
3429 static struct inode *ext4_whiteout_for_rename(struct ext4_renament *ent,
3430 int credits, handle_t **h)
3431 {
3432 struct inode *wh;
3433 handle_t *handle;
3434 int retries = 0;
3435
3436 /*
3437 * for inode block, sb block, group summaries,
3438 * and inode bitmap
3439 */
3440 credits += (EXT4_MAXQUOTAS_TRANS_BLOCKS(ent->dir->i_sb) +
3441 EXT4_XATTR_TRANS_BLOCKS + 4);
3442 retry:
3443 wh = ext4_new_inode_start_handle(ent->dir, S_IFCHR | WHITEOUT_MODE,
3444 &ent->dentry->d_name, 0, NULL,
3445 EXT4_HT_DIR, credits);
3446
3447 handle = ext4_journal_current_handle();
3448 if (IS_ERR(wh)) {
3449 if (handle)
3450 ext4_journal_stop(handle);
3451 if (PTR_ERR(wh) == -ENOSPC &&
3452 ext4_should_retry_alloc(ent->dir->i_sb, &retries))
3453 goto retry;
3454 } else {
3455 *h = handle;
3456 init_special_inode(wh, wh->i_mode, WHITEOUT_DEV);
3457 wh->i_op = &ext4_special_inode_operations;
3458 }
3459 return wh;
3460 }
3461
3462 /*
3463 * Anybody can rename anything with this: the permission checks are left to the
3464 * higher-level routines.
3465 *
3466 * n.b. old_{dentry,inode) refers to the source dentry/inode
3467 * while new_{dentry,inode) refers to the destination dentry/inode
3468 * This comes from rename(const char *oldpath, const char *newpath)
3469 */
3470 static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
3471 struct inode *new_dir, struct dentry *new_dentry,
3472 unsigned int flags)
3473 {
3474 handle_t *handle = NULL;
3475 struct ext4_renament old = {
3476 .dir = old_dir,
3477 .dentry = old_dentry,
3478 .inode = d_inode(old_dentry),
3479 };
3480 struct ext4_renament new = {
3481 .dir = new_dir,
3482 .dentry = new_dentry,
3483 .inode = d_inode(new_dentry),
3484 };
3485 int force_reread;
3486 int retval;
3487 struct inode *whiteout = NULL;
3488 int credits;
3489 u8 old_file_type;
3490
3491 retval = dquot_initialize(old.dir);
3492 if (retval)
3493 return retval;
3494 retval = dquot_initialize(new.dir);
3495 if (retval)
3496 return retval;
3497
3498 /* Initialize quotas before so that eventual writes go
3499 * in separate transaction */
3500 if (new.inode) {
3501 retval = dquot_initialize(new.inode);
3502 if (retval)
3503 return retval;
3504 }
3505
3506 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, NULL);
3507 if (IS_ERR(old.bh))
3508 return PTR_ERR(old.bh);
3509 /*
3510 * Check for inode number is _not_ due to possible IO errors.
3511 * We might rmdir the source, keep it as pwd of some process
3512 * and merrily kill the link to whatever was created under the
3513 * same name. Goodbye sticky bit ;-<
3514 */
3515 retval = -ENOENT;
3516 if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3517 goto end_rename;
3518
3519 if ((old.dir != new.dir) &&
3520 ext4_encrypted_inode(new.dir) &&
3521 !ext4_is_child_context_consistent_with_parent(new.dir,
3522 old.inode)) {
3523 retval = -EPERM;
3524 goto end_rename;
3525 }
3526
3527 new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
3528 &new.de, &new.inlined);
3529 if (IS_ERR(new.bh)) {
3530 retval = PTR_ERR(new.bh);
3531 new.bh = NULL;
3532 goto end_rename;
3533 }
3534 if (new.bh) {
3535 if (!new.inode) {
3536 brelse(new.bh);
3537 new.bh = NULL;
3538 }
3539 }
3540 if (new.inode && !test_opt(new.dir->i_sb, NO_AUTO_DA_ALLOC))
3541 ext4_alloc_da_blocks(old.inode);
3542
3543 credits = (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3544 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
3545 if (!(flags & RENAME_WHITEOUT)) {
3546 handle = ext4_journal_start(old.dir, EXT4_HT_DIR, credits);
3547 if (IS_ERR(handle)) {
3548 retval = PTR_ERR(handle);
3549 handle = NULL;
3550 goto end_rename;
3551 }
3552 } else {
3553 whiteout = ext4_whiteout_for_rename(&old, credits, &handle);
3554 if (IS_ERR(whiteout)) {
3555 retval = PTR_ERR(whiteout);
3556 whiteout = NULL;
3557 goto end_rename;
3558 }
3559 }
3560
3561 if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3562 ext4_handle_sync(handle);
3563
3564 if (S_ISDIR(old.inode->i_mode)) {
3565 if (new.inode) {
3566 retval = -ENOTEMPTY;
3567 if (!ext4_empty_dir(new.inode))
3568 goto end_rename;
3569 } else {
3570 retval = -EMLINK;
3571 if (new.dir != old.dir && EXT4_DIR_LINK_MAX(new.dir))
3572 goto end_rename;
3573 }
3574 retval = ext4_rename_dir_prepare(handle, &old);
3575 if (retval)
3576 goto end_rename;
3577 }
3578 /*
3579 * If we're renaming a file within an inline_data dir and adding or
3580 * setting the new dirent causes a conversion from inline_data to
3581 * extents/blockmap, we need to force the dirent delete code to
3582 * re-read the directory, or else we end up trying to delete a dirent
3583 * from what is now the extent tree root (or a block map).
3584 */
3585 force_reread = (new.dir->i_ino == old.dir->i_ino &&
3586 ext4_test_inode_flag(new.dir, EXT4_INODE_INLINE_DATA));
3587
3588 old_file_type = old.de->file_type;
3589 if (whiteout) {
3590 /*
3591 * Do this before adding a new entry, so the old entry is sure
3592 * to be still pointing to the valid old entry.
3593 */
3594 retval = ext4_setent(handle, &old, whiteout->i_ino,
3595 EXT4_FT_CHRDEV);
3596 if (retval)
3597 goto end_rename;
3598 ext4_mark_inode_dirty(handle, whiteout);
3599 }
3600 if (!new.bh) {
3601 retval = ext4_add_entry(handle, new.dentry, old.inode);
3602 if (retval)
3603 goto end_rename;
3604 } else {
3605 retval = ext4_setent(handle, &new,
3606 old.inode->i_ino, old_file_type);
3607 if (retval)
3608 goto end_rename;
3609 }
3610 if (force_reread)
3611 force_reread = !ext4_test_inode_flag(new.dir,
3612 EXT4_INODE_INLINE_DATA);
3613
3614 /*
3615 * Like most other Unix systems, set the ctime for inodes on a
3616 * rename.
3617 */
3618 old.inode->i_ctime = ext4_current_time(old.inode);
3619 ext4_mark_inode_dirty(handle, old.inode);
3620
3621 if (!whiteout) {
3622 /*
3623 * ok, that's it
3624 */
3625 ext4_rename_delete(handle, &old, force_reread);
3626 }
3627
3628 if (new.inode) {
3629 ext4_dec_count(handle, new.inode);
3630 new.inode->i_ctime = ext4_current_time(new.inode);
3631 }
3632 old.dir->i_ctime = old.dir->i_mtime = ext4_current_time(old.dir);
3633 ext4_update_dx_flag(old.dir);
3634 if (old.dir_bh) {
3635 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
3636 if (retval)
3637 goto end_rename;
3638
3639 ext4_dec_count(handle, old.dir);
3640 if (new.inode) {
3641 /* checked ext4_empty_dir above, can't have another
3642 * parent, ext4_dec_count() won't work for many-linked
3643 * dirs */
3644 clear_nlink(new.inode);
3645 } else {
3646 ext4_inc_count(handle, new.dir);
3647 ext4_update_dx_flag(new.dir);
3648 ext4_mark_inode_dirty(handle, new.dir);
3649 }
3650 }
3651 ext4_mark_inode_dirty(handle, old.dir);
3652 if (new.inode) {
3653 ext4_mark_inode_dirty(handle, new.inode);
3654 if (!new.inode->i_nlink)
3655 ext4_orphan_add(handle, new.inode);
3656 }
3657 retval = 0;
3658
3659 end_rename:
3660 brelse(old.dir_bh);
3661 brelse(old.bh);
3662 brelse(new.bh);
3663 if (whiteout) {
3664 if (retval)
3665 drop_nlink(whiteout);
3666 unlock_new_inode(whiteout);
3667 iput(whiteout);
3668 }
3669 if (handle)
3670 ext4_journal_stop(handle);
3671 return retval;
3672 }
3673
3674 static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
3675 struct inode *new_dir, struct dentry *new_dentry)
3676 {
3677 handle_t *handle = NULL;
3678 struct ext4_renament old = {
3679 .dir = old_dir,
3680 .dentry = old_dentry,
3681 .inode = d_inode(old_dentry),
3682 };
3683 struct ext4_renament new = {
3684 .dir = new_dir,
3685 .dentry = new_dentry,
3686 .inode = d_inode(new_dentry),
3687 };
3688 u8 new_file_type;
3689 int retval;
3690
3691 if ((ext4_encrypted_inode(old_dir) ||
3692 ext4_encrypted_inode(new_dir)) &&
3693 (old_dir != new_dir) &&
3694 (!ext4_is_child_context_consistent_with_parent(new_dir,
3695 old.inode) ||
3696 !ext4_is_child_context_consistent_with_parent(old_dir,
3697 new.inode)))
3698 return -EPERM;
3699
3700 retval = dquot_initialize(old.dir);
3701 if (retval)
3702 return retval;
3703 retval = dquot_initialize(new.dir);
3704 if (retval)
3705 return retval;
3706
3707 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name,
3708 &old.de, &old.inlined);
3709 if (IS_ERR(old.bh))
3710 return PTR_ERR(old.bh);
3711 /*
3712 * Check for inode number is _not_ due to possible IO errors.
3713 * We might rmdir the source, keep it as pwd of some process
3714 * and merrily kill the link to whatever was created under the
3715 * same name. Goodbye sticky bit ;-<
3716 */
3717 retval = -ENOENT;
3718 if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3719 goto end_rename;
3720
3721 new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
3722 &new.de, &new.inlined);
3723 if (IS_ERR(new.bh)) {
3724 retval = PTR_ERR(new.bh);
3725 new.bh = NULL;
3726 goto end_rename;
3727 }
3728
3729 /* RENAME_EXCHANGE case: old *and* new must both exist */
3730 if (!new.bh || le32_to_cpu(new.de->inode) != new.inode->i_ino)
3731 goto end_rename;
3732
3733 handle = ext4_journal_start(old.dir, EXT4_HT_DIR,
3734 (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3735 2 * EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2));
3736 if (IS_ERR(handle)) {
3737 retval = PTR_ERR(handle);
3738 handle = NULL;
3739 goto end_rename;
3740 }
3741
3742 if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3743 ext4_handle_sync(handle);
3744
3745 if (S_ISDIR(old.inode->i_mode)) {
3746 old.is_dir = true;
3747 retval = ext4_rename_dir_prepare(handle, &old);
3748 if (retval)
3749 goto end_rename;
3750 }
3751 if (S_ISDIR(new.inode->i_mode)) {
3752 new.is_dir = true;
3753 retval = ext4_rename_dir_prepare(handle, &new);
3754 if (retval)
3755 goto end_rename;
3756 }
3757
3758 /*
3759 * Other than the special case of overwriting a directory, parents'
3760 * nlink only needs to be modified if this is a cross directory rename.
3761 */
3762 if (old.dir != new.dir && old.is_dir != new.is_dir) {
3763 old.dir_nlink_delta = old.is_dir ? -1 : 1;
3764 new.dir_nlink_delta = -old.dir_nlink_delta;
3765 retval = -EMLINK;
3766 if ((old.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(old.dir)) ||
3767 (new.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(new.dir)))
3768 goto end_rename;
3769 }
3770
3771 new_file_type = new.de->file_type;
3772 retval = ext4_setent(handle, &new, old.inode->i_ino, old.de->file_type);
3773 if (retval)
3774 goto end_rename;
3775
3776 retval = ext4_setent(handle, &old, new.inode->i_ino, new_file_type);
3777 if (retval)
3778 goto end_rename;
3779
3780 /*
3781 * Like most other Unix systems, set the ctime for inodes on a
3782 * rename.
3783 */
3784 old.inode->i_ctime = ext4_current_time(old.inode);
3785 new.inode->i_ctime = ext4_current_time(new.inode);
3786 ext4_mark_inode_dirty(handle, old.inode);
3787 ext4_mark_inode_dirty(handle, new.inode);
3788
3789 if (old.dir_bh) {
3790 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
3791 if (retval)
3792 goto end_rename;
3793 }
3794 if (new.dir_bh) {
3795 retval = ext4_rename_dir_finish(handle, &new, old.dir->i_ino);
3796 if (retval)
3797 goto end_rename;
3798 }
3799 ext4_update_dir_count(handle, &old);
3800 ext4_update_dir_count(handle, &new);
3801 retval = 0;
3802
3803 end_rename:
3804 brelse(old.dir_bh);
3805 brelse(new.dir_bh);
3806 brelse(old.bh);
3807 brelse(new.bh);
3808 if (handle)
3809 ext4_journal_stop(handle);
3810 return retval;
3811 }
3812
3813 static int ext4_rename2(struct inode *old_dir, struct dentry *old_dentry,
3814 struct inode *new_dir, struct dentry *new_dentry,
3815 unsigned int flags)
3816 {
3817 if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
3818 return -EINVAL;
3819
3820 if (flags & RENAME_EXCHANGE) {
3821 return ext4_cross_rename(old_dir, old_dentry,
3822 new_dir, new_dentry);
3823 }
3824
3825 return ext4_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
3826 }
3827
3828 /*
3829 * directories can handle most operations...
3830 */
3831 const struct inode_operations ext4_dir_inode_operations = {
3832 .create = ext4_create,
3833 .lookup = ext4_lookup,
3834 .link = ext4_link,
3835 .unlink = ext4_unlink,
3836 .symlink = ext4_symlink,
3837 .mkdir = ext4_mkdir,
3838 .rmdir = ext4_rmdir,
3839 .mknod = ext4_mknod,
3840 .tmpfile = ext4_tmpfile,
3841 .rename2 = ext4_rename2,
3842 .setattr = ext4_setattr,
3843 .setxattr = generic_setxattr,
3844 .getxattr = generic_getxattr,
3845 .listxattr = ext4_listxattr,
3846 .removexattr = generic_removexattr,
3847 .get_acl = ext4_get_acl,
3848 .set_acl = ext4_set_acl,
3849 .fiemap = ext4_fiemap,
3850 };
3851
3852 const struct inode_operations ext4_special_inode_operations = {
3853 .setattr = ext4_setattr,
3854 .setxattr = generic_setxattr,
3855 .getxattr = generic_getxattr,
3856 .listxattr = ext4_listxattr,
3857 .removexattr = generic_removexattr,
3858 .get_acl = ext4_get_acl,
3859 .set_acl = ext4_set_acl,
3860 };
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