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ext4 crypto: insert encrypted filenames into a leaf directory block
[mirror_ubuntu-zesty-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, 1);
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), __LINE__)
88
89 static struct buffer_head *__ext4_read_dirblock(struct inode *inode,
90 ext4_lblk_t block,
91 dirblock_type_t type,
92 unsigned int line)
93 {
94 struct buffer_head *bh;
95 struct ext4_dir_entry *dirent;
96 int is_dx_block = 0;
97
98 bh = ext4_bread(NULL, inode, block, 0);
99 if (IS_ERR(bh)) {
100 __ext4_warning(inode->i_sb, __func__, line,
101 "error %ld reading directory block "
102 "(ino %lu, block %lu)", PTR_ERR(bh), inode->i_ino,
103 (unsigned long) block);
104
105 return bh;
106 }
107 if (!bh) {
108 ext4_error_inode(inode, __func__, line, block, "Directory hole found");
109 return ERR_PTR(-EIO);
110 }
111 dirent = (struct ext4_dir_entry *) bh->b_data;
112 /* Determine whether or not we have an index block */
113 if (is_dx(inode)) {
114 if (block == 0)
115 is_dx_block = 1;
116 else if (ext4_rec_len_from_disk(dirent->rec_len,
117 inode->i_sb->s_blocksize) ==
118 inode->i_sb->s_blocksize)
119 is_dx_block = 1;
120 }
121 if (!is_dx_block && type == INDEX) {
122 ext4_error_inode(inode, __func__, line, block,
123 "directory leaf block found instead of index block");
124 return ERR_PTR(-EIO);
125 }
126 if (!ext4_has_metadata_csum(inode->i_sb) ||
127 buffer_verified(bh))
128 return bh;
129
130 /*
131 * An empty leaf block can get mistaken for a index block; for
132 * this reason, we can only check the index checksum when the
133 * caller is sure it should be an index block.
134 */
135 if (is_dx_block && type == INDEX) {
136 if (ext4_dx_csum_verify(inode, dirent))
137 set_buffer_verified(bh);
138 else {
139 ext4_error_inode(inode, __func__, line, block,
140 "Directory index failed checksum");
141 brelse(bh);
142 return ERR_PTR(-EIO);
143 }
144 }
145 if (!is_dx_block) {
146 if (ext4_dirent_csum_verify(inode, dirent))
147 set_buffer_verified(bh);
148 else {
149 ext4_error_inode(inode, __func__, line, block,
150 "Directory block failed checksum");
151 brelse(bh);
152 return ERR_PTR(-EIO);
153 }
154 }
155 return bh;
156 }
157
158 #ifndef assert
159 #define assert(test) J_ASSERT(test)
160 #endif
161
162 #ifdef DX_DEBUG
163 #define dxtrace(command) command
164 #else
165 #define dxtrace(command)
166 #endif
167
168 struct fake_dirent
169 {
170 __le32 inode;
171 __le16 rec_len;
172 u8 name_len;
173 u8 file_type;
174 };
175
176 struct dx_countlimit
177 {
178 __le16 limit;
179 __le16 count;
180 };
181
182 struct dx_entry
183 {
184 __le32 hash;
185 __le32 block;
186 };
187
188 /*
189 * dx_root_info is laid out so that if it should somehow get overlaid by a
190 * dirent the two low bits of the hash version will be zero. Therefore, the
191 * hash version mod 4 should never be 0. Sincerely, the paranoia department.
192 */
193
194 struct dx_root
195 {
196 struct fake_dirent dot;
197 char dot_name[4];
198 struct fake_dirent dotdot;
199 char dotdot_name[4];
200 struct dx_root_info
201 {
202 __le32 reserved_zero;
203 u8 hash_version;
204 u8 info_length; /* 8 */
205 u8 indirect_levels;
206 u8 unused_flags;
207 }
208 info;
209 struct dx_entry entries[0];
210 };
211
212 struct dx_node
213 {
214 struct fake_dirent fake;
215 struct dx_entry entries[0];
216 };
217
218
219 struct dx_frame
220 {
221 struct buffer_head *bh;
222 struct dx_entry *entries;
223 struct dx_entry *at;
224 };
225
226 struct dx_map_entry
227 {
228 u32 hash;
229 u16 offs;
230 u16 size;
231 };
232
233 /*
234 * This goes at the end of each htree block.
235 */
236 struct dx_tail {
237 u32 dt_reserved;
238 __le32 dt_checksum; /* crc32c(uuid+inum+dirblock) */
239 };
240
241 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
242 static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
243 static inline unsigned dx_get_hash(struct dx_entry *entry);
244 static void dx_set_hash(struct dx_entry *entry, unsigned value);
245 static unsigned dx_get_count(struct dx_entry *entries);
246 static unsigned dx_get_limit(struct dx_entry *entries);
247 static void dx_set_count(struct dx_entry *entries, unsigned value);
248 static void dx_set_limit(struct dx_entry *entries, unsigned value);
249 static unsigned dx_root_limit(struct inode *dir, unsigned infosize);
250 static unsigned dx_node_limit(struct inode *dir);
251 static struct dx_frame *dx_probe(const struct qstr *d_name,
252 struct inode *dir,
253 struct dx_hash_info *hinfo,
254 struct dx_frame *frame);
255 static void dx_release(struct dx_frame *frames);
256 static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize,
257 struct dx_hash_info *hinfo, struct dx_map_entry map[]);
258 static void dx_sort_map(struct dx_map_entry *map, unsigned count);
259 static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to,
260 struct dx_map_entry *offsets, int count, unsigned blocksize);
261 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize);
262 static void dx_insert_block(struct dx_frame *frame,
263 u32 hash, ext4_lblk_t block);
264 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
265 struct dx_frame *frame,
266 struct dx_frame *frames,
267 __u32 *start_hash);
268 static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
269 const struct qstr *d_name,
270 struct ext4_dir_entry_2 **res_dir);
271 static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
272 struct inode *inode);
273
274 /* checksumming functions */
275 void initialize_dirent_tail(struct ext4_dir_entry_tail *t,
276 unsigned int blocksize)
277 {
278 memset(t, 0, sizeof(struct ext4_dir_entry_tail));
279 t->det_rec_len = ext4_rec_len_to_disk(
280 sizeof(struct ext4_dir_entry_tail), blocksize);
281 t->det_reserved_ft = EXT4_FT_DIR_CSUM;
282 }
283
284 /* Walk through a dirent block to find a checksum "dirent" at the tail */
285 static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode,
286 struct ext4_dir_entry *de)
287 {
288 struct ext4_dir_entry_tail *t;
289
290 #ifdef PARANOID
291 struct ext4_dir_entry *d, *top;
292
293 d = de;
294 top = (struct ext4_dir_entry *)(((void *)de) +
295 (EXT4_BLOCK_SIZE(inode->i_sb) -
296 sizeof(struct ext4_dir_entry_tail)));
297 while (d < top && d->rec_len)
298 d = (struct ext4_dir_entry *)(((void *)d) +
299 le16_to_cpu(d->rec_len));
300
301 if (d != top)
302 return NULL;
303
304 t = (struct ext4_dir_entry_tail *)d;
305 #else
306 t = EXT4_DIRENT_TAIL(de, EXT4_BLOCK_SIZE(inode->i_sb));
307 #endif
308
309 if (t->det_reserved_zero1 ||
310 le16_to_cpu(t->det_rec_len) != sizeof(struct ext4_dir_entry_tail) ||
311 t->det_reserved_zero2 ||
312 t->det_reserved_ft != EXT4_FT_DIR_CSUM)
313 return NULL;
314
315 return t;
316 }
317
318 static __le32 ext4_dirent_csum(struct inode *inode,
319 struct ext4_dir_entry *dirent, int size)
320 {
321 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
322 struct ext4_inode_info *ei = EXT4_I(inode);
323 __u32 csum;
324
325 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
326 return cpu_to_le32(csum);
327 }
328
329 static void warn_no_space_for_csum(struct inode *inode)
330 {
331 ext4_warning(inode->i_sb, "no space in directory inode %lu leaf for "
332 "checksum. Please run e2fsck -D.", inode->i_ino);
333 }
334
335 int ext4_dirent_csum_verify(struct inode *inode, struct ext4_dir_entry *dirent)
336 {
337 struct ext4_dir_entry_tail *t;
338
339 if (!ext4_has_metadata_csum(inode->i_sb))
340 return 1;
341
342 t = get_dirent_tail(inode, dirent);
343 if (!t) {
344 warn_no_space_for_csum(inode);
345 return 0;
346 }
347
348 if (t->det_checksum != ext4_dirent_csum(inode, dirent,
349 (void *)t - (void *)dirent))
350 return 0;
351
352 return 1;
353 }
354
355 static void ext4_dirent_csum_set(struct inode *inode,
356 struct ext4_dir_entry *dirent)
357 {
358 struct ext4_dir_entry_tail *t;
359
360 if (!ext4_has_metadata_csum(inode->i_sb))
361 return;
362
363 t = get_dirent_tail(inode, dirent);
364 if (!t) {
365 warn_no_space_for_csum(inode);
366 return;
367 }
368
369 t->det_checksum = ext4_dirent_csum(inode, dirent,
370 (void *)t - (void *)dirent);
371 }
372
373 int ext4_handle_dirty_dirent_node(handle_t *handle,
374 struct inode *inode,
375 struct buffer_head *bh)
376 {
377 ext4_dirent_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
378 return ext4_handle_dirty_metadata(handle, inode, bh);
379 }
380
381 static struct dx_countlimit *get_dx_countlimit(struct inode *inode,
382 struct ext4_dir_entry *dirent,
383 int *offset)
384 {
385 struct ext4_dir_entry *dp;
386 struct dx_root_info *root;
387 int count_offset;
388
389 if (le16_to_cpu(dirent->rec_len) == EXT4_BLOCK_SIZE(inode->i_sb))
390 count_offset = 8;
391 else if (le16_to_cpu(dirent->rec_len) == 12) {
392 dp = (struct ext4_dir_entry *)(((void *)dirent) + 12);
393 if (le16_to_cpu(dp->rec_len) !=
394 EXT4_BLOCK_SIZE(inode->i_sb) - 12)
395 return NULL;
396 root = (struct dx_root_info *)(((void *)dp + 12));
397 if (root->reserved_zero ||
398 root->info_length != sizeof(struct dx_root_info))
399 return NULL;
400 count_offset = 32;
401 } else
402 return NULL;
403
404 if (offset)
405 *offset = count_offset;
406 return (struct dx_countlimit *)(((void *)dirent) + count_offset);
407 }
408
409 static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent,
410 int count_offset, int count, struct dx_tail *t)
411 {
412 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
413 struct ext4_inode_info *ei = EXT4_I(inode);
414 __u32 csum;
415 __le32 save_csum;
416 int size;
417
418 size = count_offset + (count * sizeof(struct dx_entry));
419 save_csum = t->dt_checksum;
420 t->dt_checksum = 0;
421 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
422 csum = ext4_chksum(sbi, csum, (__u8 *)t, sizeof(struct dx_tail));
423 t->dt_checksum = save_csum;
424
425 return cpu_to_le32(csum);
426 }
427
428 static int ext4_dx_csum_verify(struct inode *inode,
429 struct ext4_dir_entry *dirent)
430 {
431 struct dx_countlimit *c;
432 struct dx_tail *t;
433 int count_offset, limit, count;
434
435 if (!ext4_has_metadata_csum(inode->i_sb))
436 return 1;
437
438 c = get_dx_countlimit(inode, dirent, &count_offset);
439 if (!c) {
440 EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D.");
441 return 1;
442 }
443 limit = le16_to_cpu(c->limit);
444 count = le16_to_cpu(c->count);
445 if (count_offset + (limit * sizeof(struct dx_entry)) >
446 EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
447 warn_no_space_for_csum(inode);
448 return 1;
449 }
450 t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
451
452 if (t->dt_checksum != ext4_dx_csum(inode, dirent, count_offset,
453 count, t))
454 return 0;
455 return 1;
456 }
457
458 static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent)
459 {
460 struct dx_countlimit *c;
461 struct dx_tail *t;
462 int count_offset, limit, count;
463
464 if (!ext4_has_metadata_csum(inode->i_sb))
465 return;
466
467 c = get_dx_countlimit(inode, dirent, &count_offset);
468 if (!c) {
469 EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D.");
470 return;
471 }
472 limit = le16_to_cpu(c->limit);
473 count = le16_to_cpu(c->count);
474 if (count_offset + (limit * sizeof(struct dx_entry)) >
475 EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
476 warn_no_space_for_csum(inode);
477 return;
478 }
479 t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
480
481 t->dt_checksum = ext4_dx_csum(inode, dirent, count_offset, count, t);
482 }
483
484 static inline int ext4_handle_dirty_dx_node(handle_t *handle,
485 struct inode *inode,
486 struct buffer_head *bh)
487 {
488 ext4_dx_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
489 return ext4_handle_dirty_metadata(handle, inode, bh);
490 }
491
492 /*
493 * p is at least 6 bytes before the end of page
494 */
495 static inline struct ext4_dir_entry_2 *
496 ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
497 {
498 return (struct ext4_dir_entry_2 *)((char *)p +
499 ext4_rec_len_from_disk(p->rec_len, blocksize));
500 }
501
502 /*
503 * Future: use high four bits of block for coalesce-on-delete flags
504 * Mask them off for now.
505 */
506
507 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
508 {
509 return le32_to_cpu(entry->block) & 0x00ffffff;
510 }
511
512 static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
513 {
514 entry->block = cpu_to_le32(value);
515 }
516
517 static inline unsigned dx_get_hash(struct dx_entry *entry)
518 {
519 return le32_to_cpu(entry->hash);
520 }
521
522 static inline void dx_set_hash(struct dx_entry *entry, unsigned value)
523 {
524 entry->hash = cpu_to_le32(value);
525 }
526
527 static inline unsigned dx_get_count(struct dx_entry *entries)
528 {
529 return le16_to_cpu(((struct dx_countlimit *) entries)->count);
530 }
531
532 static inline unsigned dx_get_limit(struct dx_entry *entries)
533 {
534 return le16_to_cpu(((struct dx_countlimit *) entries)->limit);
535 }
536
537 static inline void dx_set_count(struct dx_entry *entries, unsigned value)
538 {
539 ((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
540 }
541
542 static inline void dx_set_limit(struct dx_entry *entries, unsigned value)
543 {
544 ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
545 }
546
547 static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
548 {
549 unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
550 EXT4_DIR_REC_LEN(2) - infosize;
551
552 if (ext4_has_metadata_csum(dir->i_sb))
553 entry_space -= sizeof(struct dx_tail);
554 return entry_space / sizeof(struct dx_entry);
555 }
556
557 static inline unsigned dx_node_limit(struct inode *dir)
558 {
559 unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);
560
561 if (ext4_has_metadata_csum(dir->i_sb))
562 entry_space -= sizeof(struct dx_tail);
563 return entry_space / sizeof(struct dx_entry);
564 }
565
566 /*
567 * Debug
568 */
569 #ifdef DX_DEBUG
570 static void dx_show_index(char * label, struct dx_entry *entries)
571 {
572 int i, n = dx_get_count (entries);
573 printk(KERN_DEBUG "%s index ", label);
574 for (i = 0; i < n; i++) {
575 printk("%x->%lu ", i ? dx_get_hash(entries + i) :
576 0, (unsigned long)dx_get_block(entries + i));
577 }
578 printk("\n");
579 }
580
581 struct stats
582 {
583 unsigned names;
584 unsigned space;
585 unsigned bcount;
586 };
587
588 static struct stats dx_show_leaf(struct dx_hash_info *hinfo, struct ext4_dir_entry_2 *de,
589 int size, int show_names)
590 {
591 unsigned names = 0, space = 0;
592 char *base = (char *) de;
593 struct dx_hash_info h = *hinfo;
594
595 printk("names: ");
596 while ((char *) de < base + size)
597 {
598 if (de->inode)
599 {
600 if (show_names)
601 {
602 int len = de->name_len;
603 char *name = de->name;
604 while (len--) printk("%c", *name++);
605 ext4fs_dirhash(de->name, de->name_len, &h);
606 printk(":%x.%u ", h.hash,
607 (unsigned) ((char *) de - base));
608 }
609 space += EXT4_DIR_REC_LEN(de->name_len);
610 names++;
611 }
612 de = ext4_next_entry(de, size);
613 }
614 printk("(%i)\n", names);
615 return (struct stats) { names, space, 1 };
616 }
617
618 struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
619 struct dx_entry *entries, int levels)
620 {
621 unsigned blocksize = dir->i_sb->s_blocksize;
622 unsigned count = dx_get_count(entries), names = 0, space = 0, i;
623 unsigned bcount = 0;
624 struct buffer_head *bh;
625 int err;
626 printk("%i indexed blocks...\n", count);
627 for (i = 0; i < count; i++, entries++)
628 {
629 ext4_lblk_t block = dx_get_block(entries);
630 ext4_lblk_t hash = i ? dx_get_hash(entries): 0;
631 u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
632 struct stats stats;
633 printk("%s%3u:%03u hash %8x/%8x ",levels?"":" ", i, block, hash, range);
634 bh = ext4_bread(NULL,dir, block, 0);
635 if (!bh || IS_ERR(bh))
636 continue;
637 stats = levels?
638 dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
639 dx_show_leaf(hinfo, (struct ext4_dir_entry_2 *) bh->b_data, blocksize, 0);
640 names += stats.names;
641 space += stats.space;
642 bcount += stats.bcount;
643 brelse(bh);
644 }
645 if (bcount)
646 printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n",
647 levels ? "" : " ", names, space/bcount,
648 (space/bcount)*100/blocksize);
649 return (struct stats) { names, space, bcount};
650 }
651 #endif /* DX_DEBUG */
652
653 /*
654 * Probe for a directory leaf block to search.
655 *
656 * dx_probe can return ERR_BAD_DX_DIR, which means there was a format
657 * error in the directory index, and the caller should fall back to
658 * searching the directory normally. The callers of dx_probe **MUST**
659 * check for this error code, and make sure it never gets reflected
660 * back to userspace.
661 */
662 static struct dx_frame *
663 dx_probe(const struct qstr *d_name, struct inode *dir,
664 struct dx_hash_info *hinfo, struct dx_frame *frame_in)
665 {
666 unsigned count, indirect;
667 struct dx_entry *at, *entries, *p, *q, *m;
668 struct dx_root *root;
669 struct dx_frame *frame = frame_in;
670 struct dx_frame *ret_err = ERR_PTR(ERR_BAD_DX_DIR);
671 u32 hash;
672
673 frame->bh = ext4_read_dirblock(dir, 0, INDEX);
674 if (IS_ERR(frame->bh))
675 return (struct dx_frame *) frame->bh;
676
677 root = (struct dx_root *) frame->bh->b_data;
678 if (root->info.hash_version != DX_HASH_TEA &&
679 root->info.hash_version != DX_HASH_HALF_MD4 &&
680 root->info.hash_version != DX_HASH_LEGACY) {
681 ext4_warning(dir->i_sb, "Unrecognised inode hash code %d",
682 root->info.hash_version);
683 goto fail;
684 }
685 hinfo->hash_version = root->info.hash_version;
686 if (hinfo->hash_version <= DX_HASH_TEA)
687 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
688 hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
689 if (d_name)
690 ext4fs_dirhash(d_name->name, d_name->len, hinfo);
691 hash = hinfo->hash;
692
693 if (root->info.unused_flags & 1) {
694 ext4_warning(dir->i_sb, "Unimplemented inode hash flags: %#06x",
695 root->info.unused_flags);
696 goto fail;
697 }
698
699 if ((indirect = root->info.indirect_levels) > 1) {
700 ext4_warning(dir->i_sb, "Unimplemented inode hash depth: %#06x",
701 root->info.indirect_levels);
702 goto fail;
703 }
704
705 entries = (struct dx_entry *) (((char *)&root->info) +
706 root->info.info_length);
707
708 if (dx_get_limit(entries) != dx_root_limit(dir,
709 root->info.info_length)) {
710 ext4_warning(dir->i_sb, "dx entry: limit != root limit");
711 goto fail;
712 }
713
714 dxtrace(printk("Look up %x", hash));
715 while (1) {
716 count = dx_get_count(entries);
717 if (!count || count > dx_get_limit(entries)) {
718 ext4_warning(dir->i_sb,
719 "dx entry: no count or count > limit");
720 goto fail;
721 }
722
723 p = entries + 1;
724 q = entries + count - 1;
725 while (p <= q) {
726 m = p + (q - p)/2;
727 dxtrace(printk("."));
728 if (dx_get_hash(m) > hash)
729 q = m - 1;
730 else
731 p = m + 1;
732 }
733
734 if (0) { // linear search cross check
735 unsigned n = count - 1;
736 at = entries;
737 while (n--)
738 {
739 dxtrace(printk(","));
740 if (dx_get_hash(++at) > hash)
741 {
742 at--;
743 break;
744 }
745 }
746 assert (at == p - 1);
747 }
748
749 at = p - 1;
750 dxtrace(printk(" %x->%u\n", at == entries? 0: dx_get_hash(at), dx_get_block(at)));
751 frame->entries = entries;
752 frame->at = at;
753 if (!indirect--)
754 return frame;
755 frame++;
756 frame->bh = ext4_read_dirblock(dir, dx_get_block(at), INDEX);
757 if (IS_ERR(frame->bh)) {
758 ret_err = (struct dx_frame *) frame->bh;
759 frame->bh = NULL;
760 goto fail;
761 }
762 entries = ((struct dx_node *) frame->bh->b_data)->entries;
763
764 if (dx_get_limit(entries) != dx_node_limit (dir)) {
765 ext4_warning(dir->i_sb,
766 "dx entry: limit != node limit");
767 goto fail;
768 }
769 }
770 fail:
771 while (frame >= frame_in) {
772 brelse(frame->bh);
773 frame--;
774 }
775 if (ret_err == ERR_PTR(ERR_BAD_DX_DIR))
776 ext4_warning(dir->i_sb,
777 "Corrupt dir inode %lu, running e2fsck is "
778 "recommended.", dir->i_ino);
779 return ret_err;
780 }
781
782 static void dx_release (struct dx_frame *frames)
783 {
784 if (frames[0].bh == NULL)
785 return;
786
787 if (((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels)
788 brelse(frames[1].bh);
789 brelse(frames[0].bh);
790 }
791
792 /*
793 * This function increments the frame pointer to search the next leaf
794 * block, and reads in the necessary intervening nodes if the search
795 * should be necessary. Whether or not the search is necessary is
796 * controlled by the hash parameter. If the hash value is even, then
797 * the search is only continued if the next block starts with that
798 * hash value. This is used if we are searching for a specific file.
799 *
800 * If the hash value is HASH_NB_ALWAYS, then always go to the next block.
801 *
802 * This function returns 1 if the caller should continue to search,
803 * or 0 if it should not. If there is an error reading one of the
804 * index blocks, it will a negative error code.
805 *
806 * If start_hash is non-null, it will be filled in with the starting
807 * hash of the next page.
808 */
809 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
810 struct dx_frame *frame,
811 struct dx_frame *frames,
812 __u32 *start_hash)
813 {
814 struct dx_frame *p;
815 struct buffer_head *bh;
816 int num_frames = 0;
817 __u32 bhash;
818
819 p = frame;
820 /*
821 * Find the next leaf page by incrementing the frame pointer.
822 * If we run out of entries in the interior node, loop around and
823 * increment pointer in the parent node. When we break out of
824 * this loop, num_frames indicates the number of interior
825 * nodes need to be read.
826 */
827 while (1) {
828 if (++(p->at) < p->entries + dx_get_count(p->entries))
829 break;
830 if (p == frames)
831 return 0;
832 num_frames++;
833 p--;
834 }
835
836 /*
837 * If the hash is 1, then continue only if the next page has a
838 * continuation hash of any value. This is used for readdir
839 * handling. Otherwise, check to see if the hash matches the
840 * desired contiuation hash. If it doesn't, return since
841 * there's no point to read in the successive index pages.
842 */
843 bhash = dx_get_hash(p->at);
844 if (start_hash)
845 *start_hash = bhash;
846 if ((hash & 1) == 0) {
847 if ((bhash & ~1) != hash)
848 return 0;
849 }
850 /*
851 * If the hash is HASH_NB_ALWAYS, we always go to the next
852 * block so no check is necessary
853 */
854 while (num_frames--) {
855 bh = ext4_read_dirblock(dir, dx_get_block(p->at), INDEX);
856 if (IS_ERR(bh))
857 return PTR_ERR(bh);
858 p++;
859 brelse(p->bh);
860 p->bh = bh;
861 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
862 }
863 return 1;
864 }
865
866
867 /*
868 * This function fills a red-black tree with information from a
869 * directory block. It returns the number directory entries loaded
870 * into the tree. If there is an error it is returned in err.
871 */
872 static int htree_dirblock_to_tree(struct file *dir_file,
873 struct inode *dir, ext4_lblk_t block,
874 struct dx_hash_info *hinfo,
875 __u32 start_hash, __u32 start_minor_hash)
876 {
877 struct buffer_head *bh;
878 struct ext4_dir_entry_2 *de, *top;
879 int err = 0, count = 0;
880 struct ext4_str tmp_str;
881
882 dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
883 (unsigned long)block));
884 bh = ext4_read_dirblock(dir, block, DIRENT);
885 if (IS_ERR(bh))
886 return PTR_ERR(bh);
887
888 de = (struct ext4_dir_entry_2 *) bh->b_data;
889 top = (struct ext4_dir_entry_2 *) ((char *) de +
890 dir->i_sb->s_blocksize -
891 EXT4_DIR_REC_LEN(0));
892 for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) {
893 if (ext4_check_dir_entry(dir, NULL, de, bh,
894 bh->b_data, bh->b_size,
895 (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
896 + ((char *)de - bh->b_data))) {
897 /* silently ignore the rest of the block */
898 break;
899 }
900 ext4fs_dirhash(de->name, de->name_len, hinfo);
901 if ((hinfo->hash < start_hash) ||
902 ((hinfo->hash == start_hash) &&
903 (hinfo->minor_hash < start_minor_hash)))
904 continue;
905 if (de->inode == 0)
906 continue;
907 tmp_str.name = de->name;
908 tmp_str.len = de->name_len;
909 err = ext4_htree_store_dirent(dir_file,
910 hinfo->hash, hinfo->minor_hash, de, &tmp_str);
911 if (err != 0) {
912 brelse(bh);
913 return err;
914 }
915 count++;
916 }
917 brelse(bh);
918 return count;
919 }
920
921
922 /*
923 * This function fills a red-black tree with information from a
924 * directory. We start scanning the directory in hash order, starting
925 * at start_hash and start_minor_hash.
926 *
927 * This function returns the number of entries inserted into the tree,
928 * or a negative error code.
929 */
930 int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
931 __u32 start_minor_hash, __u32 *next_hash)
932 {
933 struct dx_hash_info hinfo;
934 struct ext4_dir_entry_2 *de;
935 struct dx_frame frames[2], *frame;
936 struct inode *dir;
937 ext4_lblk_t block;
938 int count = 0;
939 int ret, err;
940 __u32 hashval;
941 struct ext4_str tmp_str;
942
943 dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
944 start_hash, start_minor_hash));
945 dir = file_inode(dir_file);
946 if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) {
947 hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
948 if (hinfo.hash_version <= DX_HASH_TEA)
949 hinfo.hash_version +=
950 EXT4_SB(dir->i_sb)->s_hash_unsigned;
951 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
952 if (ext4_has_inline_data(dir)) {
953 int has_inline_data = 1;
954 count = htree_inlinedir_to_tree(dir_file, dir, 0,
955 &hinfo, start_hash,
956 start_minor_hash,
957 &has_inline_data);
958 if (has_inline_data) {
959 *next_hash = ~0;
960 return count;
961 }
962 }
963 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
964 start_hash, start_minor_hash);
965 *next_hash = ~0;
966 return count;
967 }
968 hinfo.hash = start_hash;
969 hinfo.minor_hash = 0;
970 frame = dx_probe(NULL, dir, &hinfo, frames);
971 if (IS_ERR(frame))
972 return PTR_ERR(frame);
973
974 /* Add '.' and '..' from the htree header */
975 if (!start_hash && !start_minor_hash) {
976 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
977 tmp_str.name = de->name;
978 tmp_str.len = de->name_len;
979 err = ext4_htree_store_dirent(dir_file, 0, 0,
980 de, &tmp_str);
981 if (err != 0)
982 goto errout;
983 count++;
984 }
985 if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
986 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
987 de = ext4_next_entry(de, dir->i_sb->s_blocksize);
988 tmp_str.name = de->name;
989 tmp_str.len = de->name_len;
990 err = ext4_htree_store_dirent(dir_file, 2, 0,
991 de, &tmp_str);
992 if (err != 0)
993 goto errout;
994 count++;
995 }
996
997 while (1) {
998 block = dx_get_block(frame->at);
999 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
1000 start_hash, start_minor_hash);
1001 if (ret < 0) {
1002 err = ret;
1003 goto errout;
1004 }
1005 count += ret;
1006 hashval = ~0;
1007 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
1008 frame, frames, &hashval);
1009 *next_hash = hashval;
1010 if (ret < 0) {
1011 err = ret;
1012 goto errout;
1013 }
1014 /*
1015 * Stop if: (a) there are no more entries, or
1016 * (b) we have inserted at least one entry and the
1017 * next hash value is not a continuation
1018 */
1019 if ((ret == 0) ||
1020 (count && ((hashval & 1) == 0)))
1021 break;
1022 }
1023 dx_release(frames);
1024 dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, "
1025 "next hash: %x\n", count, *next_hash));
1026 return count;
1027 errout:
1028 dx_release(frames);
1029 return (err);
1030 }
1031
1032 static inline int search_dirblock(struct buffer_head *bh,
1033 struct inode *dir,
1034 const struct qstr *d_name,
1035 unsigned int offset,
1036 struct ext4_dir_entry_2 **res_dir)
1037 {
1038 return search_dir(bh, bh->b_data, dir->i_sb->s_blocksize, dir,
1039 d_name, offset, res_dir);
1040 }
1041
1042 /*
1043 * Directory block splitting, compacting
1044 */
1045
1046 /*
1047 * Create map of hash values, offsets, and sizes, stored at end of block.
1048 * Returns number of entries mapped.
1049 */
1050 static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize,
1051 struct dx_hash_info *hinfo,
1052 struct dx_map_entry *map_tail)
1053 {
1054 int count = 0;
1055 char *base = (char *) de;
1056 struct dx_hash_info h = *hinfo;
1057
1058 while ((char *) de < base + blocksize) {
1059 if (de->name_len && de->inode) {
1060 ext4fs_dirhash(de->name, de->name_len, &h);
1061 map_tail--;
1062 map_tail->hash = h.hash;
1063 map_tail->offs = ((char *) de - base)>>2;
1064 map_tail->size = le16_to_cpu(de->rec_len);
1065 count++;
1066 cond_resched();
1067 }
1068 /* XXX: do we need to check rec_len == 0 case? -Chris */
1069 de = ext4_next_entry(de, blocksize);
1070 }
1071 return count;
1072 }
1073
1074 /* Sort map by hash value */
1075 static void dx_sort_map (struct dx_map_entry *map, unsigned count)
1076 {
1077 struct dx_map_entry *p, *q, *top = map + count - 1;
1078 int more;
1079 /* Combsort until bubble sort doesn't suck */
1080 while (count > 2) {
1081 count = count*10/13;
1082 if (count - 9 < 2) /* 9, 10 -> 11 */
1083 count = 11;
1084 for (p = top, q = p - count; q >= map; p--, q--)
1085 if (p->hash < q->hash)
1086 swap(*p, *q);
1087 }
1088 /* Garden variety bubble sort */
1089 do {
1090 more = 0;
1091 q = top;
1092 while (q-- > map) {
1093 if (q[1].hash >= q[0].hash)
1094 continue;
1095 swap(*(q+1), *q);
1096 more = 1;
1097 }
1098 } while(more);
1099 }
1100
1101 static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
1102 {
1103 struct dx_entry *entries = frame->entries;
1104 struct dx_entry *old = frame->at, *new = old + 1;
1105 int count = dx_get_count(entries);
1106
1107 assert(count < dx_get_limit(entries));
1108 assert(old < entries + count);
1109 memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
1110 dx_set_hash(new, hash);
1111 dx_set_block(new, block);
1112 dx_set_count(entries, count + 1);
1113 }
1114
1115 /*
1116 * NOTE! unlike strncmp, ext4_match returns 1 for success, 0 for failure.
1117 *
1118 * `len <= EXT4_NAME_LEN' is guaranteed by caller.
1119 * `de != NULL' is guaranteed by caller.
1120 */
1121 static inline int ext4_match (int len, const char * const name,
1122 struct ext4_dir_entry_2 * de)
1123 {
1124 if (len != de->name_len)
1125 return 0;
1126 if (!de->inode)
1127 return 0;
1128 return !memcmp(name, de->name, len);
1129 }
1130
1131 /*
1132 * Returns 0 if not found, -1 on failure, and 1 on success
1133 */
1134 int search_dir(struct buffer_head *bh,
1135 char *search_buf,
1136 int buf_size,
1137 struct inode *dir,
1138 const struct qstr *d_name,
1139 unsigned int offset,
1140 struct ext4_dir_entry_2 **res_dir)
1141 {
1142 struct ext4_dir_entry_2 * de;
1143 char * dlimit;
1144 int de_len;
1145 const char *name = d_name->name;
1146 int namelen = d_name->len;
1147
1148 de = (struct ext4_dir_entry_2 *)search_buf;
1149 dlimit = search_buf + buf_size;
1150 while ((char *) de < dlimit) {
1151 /* this code is executed quadratically often */
1152 /* do minimal checking `by hand' */
1153
1154 if ((char *) de + namelen <= dlimit &&
1155 ext4_match (namelen, name, de)) {
1156 /* found a match - just to be sure, do a full check */
1157 if (ext4_check_dir_entry(dir, NULL, de, bh, bh->b_data,
1158 bh->b_size, offset))
1159 return -1;
1160 *res_dir = de;
1161 return 1;
1162 }
1163 /* prevent looping on a bad block */
1164 de_len = ext4_rec_len_from_disk(de->rec_len,
1165 dir->i_sb->s_blocksize);
1166 if (de_len <= 0)
1167 return -1;
1168 offset += de_len;
1169 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
1170 }
1171 return 0;
1172 }
1173
1174 static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block,
1175 struct ext4_dir_entry *de)
1176 {
1177 struct super_block *sb = dir->i_sb;
1178
1179 if (!is_dx(dir))
1180 return 0;
1181 if (block == 0)
1182 return 1;
1183 if (de->inode == 0 &&
1184 ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) ==
1185 sb->s_blocksize)
1186 return 1;
1187 return 0;
1188 }
1189
1190 /*
1191 * ext4_find_entry()
1192 *
1193 * finds an entry in the specified directory with the wanted name. It
1194 * returns the cache buffer in which the entry was found, and the entry
1195 * itself (as a parameter - res_dir). It does NOT read the inode of the
1196 * entry - you'll have to do that yourself if you want to.
1197 *
1198 * The returned buffer_head has ->b_count elevated. The caller is expected
1199 * to brelse() it when appropriate.
1200 */
1201 static struct buffer_head * ext4_find_entry (struct inode *dir,
1202 const struct qstr *d_name,
1203 struct ext4_dir_entry_2 **res_dir,
1204 int *inlined)
1205 {
1206 struct super_block *sb;
1207 struct buffer_head *bh_use[NAMEI_RA_SIZE];
1208 struct buffer_head *bh, *ret = NULL;
1209 ext4_lblk_t start, block, b;
1210 const u8 *name = d_name->name;
1211 int ra_max = 0; /* Number of bh's in the readahead
1212 buffer, bh_use[] */
1213 int ra_ptr = 0; /* Current index into readahead
1214 buffer */
1215 int num = 0;
1216 ext4_lblk_t nblocks;
1217 int i, namelen;
1218
1219 *res_dir = NULL;
1220 sb = dir->i_sb;
1221 namelen = d_name->len;
1222 if (namelen > EXT4_NAME_LEN)
1223 return NULL;
1224
1225 if (ext4_has_inline_data(dir)) {
1226 int has_inline_data = 1;
1227 ret = ext4_find_inline_entry(dir, d_name, res_dir,
1228 &has_inline_data);
1229 if (has_inline_data) {
1230 if (inlined)
1231 *inlined = 1;
1232 return ret;
1233 }
1234 }
1235
1236 if ((namelen <= 2) && (name[0] == '.') &&
1237 (name[1] == '.' || name[1] == '\0')) {
1238 /*
1239 * "." or ".." will only be in the first block
1240 * NFS may look up ".."; "." should be handled by the VFS
1241 */
1242 block = start = 0;
1243 nblocks = 1;
1244 goto restart;
1245 }
1246 if (is_dx(dir)) {
1247 bh = ext4_dx_find_entry(dir, d_name, res_dir);
1248 /*
1249 * On success, or if the error was file not found,
1250 * return. Otherwise, fall back to doing a search the
1251 * old fashioned way.
1252 */
1253 if (!IS_ERR(bh) || PTR_ERR(bh) != ERR_BAD_DX_DIR)
1254 return bh;
1255 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
1256 "falling back\n"));
1257 }
1258 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1259 start = EXT4_I(dir)->i_dir_start_lookup;
1260 if (start >= nblocks)
1261 start = 0;
1262 block = start;
1263 restart:
1264 do {
1265 /*
1266 * We deal with the read-ahead logic here.
1267 */
1268 if (ra_ptr >= ra_max) {
1269 /* Refill the readahead buffer */
1270 ra_ptr = 0;
1271 b = block;
1272 for (ra_max = 0; ra_max < NAMEI_RA_SIZE; ra_max++) {
1273 /*
1274 * Terminate if we reach the end of the
1275 * directory and must wrap, or if our
1276 * search has finished at this block.
1277 */
1278 if (b >= nblocks || (num && block == start)) {
1279 bh_use[ra_max] = NULL;
1280 break;
1281 }
1282 num++;
1283 bh = ext4_getblk(NULL, dir, b++, 0);
1284 if (unlikely(IS_ERR(bh))) {
1285 if (ra_max == 0)
1286 return bh;
1287 break;
1288 }
1289 bh_use[ra_max] = bh;
1290 if (bh)
1291 ll_rw_block(READ | REQ_META | REQ_PRIO,
1292 1, &bh);
1293 }
1294 }
1295 if ((bh = bh_use[ra_ptr++]) == NULL)
1296 goto next;
1297 wait_on_buffer(bh);
1298 if (!buffer_uptodate(bh)) {
1299 /* read error, skip block & hope for the best */
1300 EXT4_ERROR_INODE(dir, "reading directory lblock %lu",
1301 (unsigned long) block);
1302 brelse(bh);
1303 goto next;
1304 }
1305 if (!buffer_verified(bh) &&
1306 !is_dx_internal_node(dir, block,
1307 (struct ext4_dir_entry *)bh->b_data) &&
1308 !ext4_dirent_csum_verify(dir,
1309 (struct ext4_dir_entry *)bh->b_data)) {
1310 EXT4_ERROR_INODE(dir, "checksumming directory "
1311 "block %lu", (unsigned long)block);
1312 brelse(bh);
1313 goto next;
1314 }
1315 set_buffer_verified(bh);
1316 i = search_dirblock(bh, dir, d_name,
1317 block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
1318 if (i == 1) {
1319 EXT4_I(dir)->i_dir_start_lookup = block;
1320 ret = bh;
1321 goto cleanup_and_exit;
1322 } else {
1323 brelse(bh);
1324 if (i < 0)
1325 goto cleanup_and_exit;
1326 }
1327 next:
1328 if (++block >= nblocks)
1329 block = 0;
1330 } while (block != start);
1331
1332 /*
1333 * If the directory has grown while we were searching, then
1334 * search the last part of the directory before giving up.
1335 */
1336 block = nblocks;
1337 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1338 if (block < nblocks) {
1339 start = 0;
1340 goto restart;
1341 }
1342
1343 cleanup_and_exit:
1344 /* Clean up the read-ahead blocks */
1345 for (; ra_ptr < ra_max; ra_ptr++)
1346 brelse(bh_use[ra_ptr]);
1347 return ret;
1348 }
1349
1350 static struct buffer_head * ext4_dx_find_entry(struct inode *dir, const struct qstr *d_name,
1351 struct ext4_dir_entry_2 **res_dir)
1352 {
1353 struct super_block * sb = dir->i_sb;
1354 struct dx_hash_info hinfo;
1355 struct dx_frame frames[2], *frame;
1356 struct buffer_head *bh;
1357 ext4_lblk_t block;
1358 int retval;
1359
1360 frame = dx_probe(d_name, dir, &hinfo, frames);
1361 if (IS_ERR(frame))
1362 return (struct buffer_head *) frame;
1363 do {
1364 block = dx_get_block(frame->at);
1365 bh = ext4_read_dirblock(dir, block, DIRENT);
1366 if (IS_ERR(bh))
1367 goto errout;
1368
1369 retval = search_dirblock(bh, dir, d_name,
1370 block << EXT4_BLOCK_SIZE_BITS(sb),
1371 res_dir);
1372 if (retval == 1)
1373 goto success;
1374 brelse(bh);
1375 if (retval == -1) {
1376 bh = ERR_PTR(ERR_BAD_DX_DIR);
1377 goto errout;
1378 }
1379
1380 /* Check to see if we should continue to search */
1381 retval = ext4_htree_next_block(dir, hinfo.hash, frame,
1382 frames, NULL);
1383 if (retval < 0) {
1384 ext4_warning(sb,
1385 "error %d reading index page in directory #%lu",
1386 retval, dir->i_ino);
1387 bh = ERR_PTR(retval);
1388 goto errout;
1389 }
1390 } while (retval == 1);
1391
1392 bh = NULL;
1393 errout:
1394 dxtrace(printk(KERN_DEBUG "%s not found\n", d_name->name));
1395 success:
1396 dx_release(frames);
1397 return bh;
1398 }
1399
1400 static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
1401 {
1402 struct inode *inode;
1403 struct ext4_dir_entry_2 *de;
1404 struct buffer_head *bh;
1405
1406 if (dentry->d_name.len > EXT4_NAME_LEN)
1407 return ERR_PTR(-ENAMETOOLONG);
1408
1409 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
1410 if (IS_ERR(bh))
1411 return (struct dentry *) bh;
1412 inode = NULL;
1413 if (bh) {
1414 __u32 ino = le32_to_cpu(de->inode);
1415 brelse(bh);
1416 if (!ext4_valid_inum(dir->i_sb, ino)) {
1417 EXT4_ERROR_INODE(dir, "bad inode number: %u", ino);
1418 return ERR_PTR(-EIO);
1419 }
1420 if (unlikely(ino == dir->i_ino)) {
1421 EXT4_ERROR_INODE(dir, "'%pd' linked to parent dir",
1422 dentry);
1423 return ERR_PTR(-EIO);
1424 }
1425 inode = ext4_iget_normal(dir->i_sb, ino);
1426 if (inode == ERR_PTR(-ESTALE)) {
1427 EXT4_ERROR_INODE(dir,
1428 "deleted inode referenced: %u",
1429 ino);
1430 return ERR_PTR(-EIO);
1431 }
1432 if (!IS_ERR(inode) && ext4_encrypted_inode(dir) &&
1433 (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
1434 S_ISLNK(inode->i_mode)) &&
1435 !ext4_is_child_context_consistent_with_parent(dir,
1436 inode)) {
1437 iput(inode);
1438 ext4_warning(inode->i_sb,
1439 "Inconsistent encryption contexts: %lu/%lu\n",
1440 (unsigned long) dir->i_ino,
1441 (unsigned long) inode->i_ino);
1442 return ERR_PTR(-EPERM);
1443 }
1444 }
1445 return d_splice_alias(inode, dentry);
1446 }
1447
1448
1449 struct dentry *ext4_get_parent(struct dentry *child)
1450 {
1451 __u32 ino;
1452 static const struct qstr dotdot = QSTR_INIT("..", 2);
1453 struct ext4_dir_entry_2 * de;
1454 struct buffer_head *bh;
1455
1456 bh = ext4_find_entry(child->d_inode, &dotdot, &de, NULL);
1457 if (IS_ERR(bh))
1458 return (struct dentry *) bh;
1459 if (!bh)
1460 return ERR_PTR(-ENOENT);
1461 ino = le32_to_cpu(de->inode);
1462 brelse(bh);
1463
1464 if (!ext4_valid_inum(child->d_inode->i_sb, ino)) {
1465 EXT4_ERROR_INODE(child->d_inode,
1466 "bad parent inode number: %u", ino);
1467 return ERR_PTR(-EIO);
1468 }
1469
1470 return d_obtain_alias(ext4_iget_normal(child->d_inode->i_sb, ino));
1471 }
1472
1473 /*
1474 * Move count entries from end of map between two memory locations.
1475 * Returns pointer to last entry moved.
1476 */
1477 static struct ext4_dir_entry_2 *
1478 dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count,
1479 unsigned blocksize)
1480 {
1481 unsigned rec_len = 0;
1482
1483 while (count--) {
1484 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
1485 (from + (map->offs<<2));
1486 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1487 memcpy (to, de, rec_len);
1488 ((struct ext4_dir_entry_2 *) to)->rec_len =
1489 ext4_rec_len_to_disk(rec_len, blocksize);
1490 de->inode = 0;
1491 map++;
1492 to += rec_len;
1493 }
1494 return (struct ext4_dir_entry_2 *) (to - rec_len);
1495 }
1496
1497 /*
1498 * Compact each dir entry in the range to the minimal rec_len.
1499 * Returns pointer to last entry in range.
1500 */
1501 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize)
1502 {
1503 struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
1504 unsigned rec_len = 0;
1505
1506 prev = to = de;
1507 while ((char*)de < base + blocksize) {
1508 next = ext4_next_entry(de, blocksize);
1509 if (de->inode && de->name_len) {
1510 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1511 if (de > to)
1512 memmove(to, de, rec_len);
1513 to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
1514 prev = to;
1515 to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
1516 }
1517 de = next;
1518 }
1519 return prev;
1520 }
1521
1522 /*
1523 * Split a full leaf block to make room for a new dir entry.
1524 * Allocate a new block, and move entries so that they are approx. equally full.
1525 * Returns pointer to de in block into which the new entry will be inserted.
1526 */
1527 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
1528 struct buffer_head **bh,struct dx_frame *frame,
1529 struct dx_hash_info *hinfo)
1530 {
1531 unsigned blocksize = dir->i_sb->s_blocksize;
1532 unsigned count, continued;
1533 struct buffer_head *bh2;
1534 ext4_lblk_t newblock;
1535 u32 hash2;
1536 struct dx_map_entry *map;
1537 char *data1 = (*bh)->b_data, *data2;
1538 unsigned split, move, size;
1539 struct ext4_dir_entry_2 *de = NULL, *de2;
1540 struct ext4_dir_entry_tail *t;
1541 int csum_size = 0;
1542 int err = 0, i;
1543
1544 if (ext4_has_metadata_csum(dir->i_sb))
1545 csum_size = sizeof(struct ext4_dir_entry_tail);
1546
1547 bh2 = ext4_append(handle, dir, &newblock);
1548 if (IS_ERR(bh2)) {
1549 brelse(*bh);
1550 *bh = NULL;
1551 return (struct ext4_dir_entry_2 *) bh2;
1552 }
1553
1554 BUFFER_TRACE(*bh, "get_write_access");
1555 err = ext4_journal_get_write_access(handle, *bh);
1556 if (err)
1557 goto journal_error;
1558
1559 BUFFER_TRACE(frame->bh, "get_write_access");
1560 err = ext4_journal_get_write_access(handle, frame->bh);
1561 if (err)
1562 goto journal_error;
1563
1564 data2 = bh2->b_data;
1565
1566 /* create map in the end of data2 block */
1567 map = (struct dx_map_entry *) (data2 + blocksize);
1568 count = dx_make_map((struct ext4_dir_entry_2 *) data1,
1569 blocksize, hinfo, map);
1570 map -= count;
1571 dx_sort_map(map, count);
1572 /* Split the existing block in the middle, size-wise */
1573 size = 0;
1574 move = 0;
1575 for (i = count-1; i >= 0; i--) {
1576 /* is more than half of this entry in 2nd half of the block? */
1577 if (size + map[i].size/2 > blocksize/2)
1578 break;
1579 size += map[i].size;
1580 move++;
1581 }
1582 /* map index at which we will split */
1583 split = count - move;
1584 hash2 = map[split].hash;
1585 continued = hash2 == map[split - 1].hash;
1586 dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
1587 (unsigned long)dx_get_block(frame->at),
1588 hash2, split, count-split));
1589
1590 /* Fancy dance to stay within two buffers */
1591 de2 = dx_move_dirents(data1, data2, map + split, count - split, blocksize);
1592 de = dx_pack_dirents(data1, blocksize);
1593 de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
1594 (char *) de,
1595 blocksize);
1596 de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
1597 (char *) de2,
1598 blocksize);
1599 if (csum_size) {
1600 t = EXT4_DIRENT_TAIL(data2, blocksize);
1601 initialize_dirent_tail(t, blocksize);
1602
1603 t = EXT4_DIRENT_TAIL(data1, blocksize);
1604 initialize_dirent_tail(t, blocksize);
1605 }
1606
1607 dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data1, blocksize, 1));
1608 dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data2, blocksize, 1));
1609
1610 /* Which block gets the new entry? */
1611 if (hinfo->hash >= hash2) {
1612 swap(*bh, bh2);
1613 de = de2;
1614 }
1615 dx_insert_block(frame, hash2 + continued, newblock);
1616 err = ext4_handle_dirty_dirent_node(handle, dir, bh2);
1617 if (err)
1618 goto journal_error;
1619 err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
1620 if (err)
1621 goto journal_error;
1622 brelse(bh2);
1623 dxtrace(dx_show_index("frame", frame->entries));
1624 return de;
1625
1626 journal_error:
1627 brelse(*bh);
1628 brelse(bh2);
1629 *bh = NULL;
1630 ext4_std_error(dir->i_sb, err);
1631 return ERR_PTR(err);
1632 }
1633
1634 int ext4_find_dest_de(struct inode *dir, struct inode *inode,
1635 struct buffer_head *bh,
1636 void *buf, int buf_size,
1637 const char *name, int namelen,
1638 struct ext4_dir_entry_2 **dest_de)
1639 {
1640 struct ext4_dir_entry_2 *de;
1641 unsigned short reclen = EXT4_DIR_REC_LEN(namelen);
1642 int nlen, rlen;
1643 unsigned int offset = 0;
1644 char *top;
1645
1646 de = (struct ext4_dir_entry_2 *)buf;
1647 top = buf + buf_size - reclen;
1648 while ((char *) de <= top) {
1649 if (ext4_check_dir_entry(dir, NULL, de, bh,
1650 buf, buf_size, offset))
1651 return -EIO;
1652 if (ext4_match(namelen, name, de))
1653 return -EEXIST;
1654 nlen = EXT4_DIR_REC_LEN(de->name_len);
1655 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
1656 if ((de->inode ? rlen - nlen : rlen) >= reclen)
1657 break;
1658 de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
1659 offset += rlen;
1660 }
1661 if ((char *) de > top)
1662 return -ENOSPC;
1663
1664 *dest_de = de;
1665 return 0;
1666 }
1667
1668 int ext4_insert_dentry(struct inode *dir,
1669 struct inode *inode,
1670 struct ext4_dir_entry_2 *de,
1671 int buf_size,
1672 const struct qstr *iname,
1673 const char *name, int namelen)
1674 {
1675
1676 int nlen, rlen;
1677 struct ext4_fname_crypto_ctx *ctx = NULL;
1678 struct ext4_str fname_crypto_str = {.name = NULL, .len = 0};
1679 struct ext4_str tmp_str;
1680 int res;
1681
1682 ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN);
1683 if (IS_ERR(ctx))
1684 return -EIO;
1685 /* By default, the input name would be written to the disk */
1686 tmp_str.name = (unsigned char *)name;
1687 tmp_str.len = namelen;
1688 if (ctx != NULL) {
1689 /* Directory is encrypted */
1690 res = ext4_fname_crypto_alloc_buffer(ctx, EXT4_NAME_LEN,
1691 &fname_crypto_str);
1692 if (res < 0) {
1693 ext4_put_fname_crypto_ctx(&ctx);
1694 return -ENOMEM;
1695 }
1696 res = ext4_fname_usr_to_disk(ctx, iname, &fname_crypto_str);
1697 if (res < 0) {
1698 ext4_put_fname_crypto_ctx(&ctx);
1699 ext4_fname_crypto_free_buffer(&fname_crypto_str);
1700 return res;
1701 }
1702 tmp_str.name = fname_crypto_str.name;
1703 tmp_str.len = fname_crypto_str.len;
1704 }
1705
1706 nlen = EXT4_DIR_REC_LEN(de->name_len);
1707 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
1708 if (de->inode) {
1709 struct ext4_dir_entry_2 *de1 =
1710 (struct ext4_dir_entry_2 *)((char *)de + nlen);
1711 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, buf_size);
1712 de->rec_len = ext4_rec_len_to_disk(nlen, buf_size);
1713 de = de1;
1714 }
1715 de->file_type = EXT4_FT_UNKNOWN;
1716 de->inode = cpu_to_le32(inode->i_ino);
1717 ext4_set_de_type(inode->i_sb, de, inode->i_mode);
1718 de->name_len = tmp_str.len;
1719
1720 memcpy(de->name, tmp_str.name, tmp_str.len);
1721 ext4_put_fname_crypto_ctx(&ctx);
1722 ext4_fname_crypto_free_buffer(&fname_crypto_str);
1723 return 0;
1724 }
1725
1726 /*
1727 * Add a new entry into a directory (leaf) block. If de is non-NULL,
1728 * it points to a directory entry which is guaranteed to be large
1729 * enough for new directory entry. If de is NULL, then
1730 * add_dirent_to_buf will attempt search the directory block for
1731 * space. It will return -ENOSPC if no space is available, and -EIO
1732 * and -EEXIST if directory entry already exists.
1733 */
1734 static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
1735 struct inode *inode, struct ext4_dir_entry_2 *de,
1736 struct buffer_head *bh)
1737 {
1738 struct inode *dir = dentry->d_parent->d_inode;
1739 const char *name = dentry->d_name.name;
1740 int namelen = dentry->d_name.len;
1741 unsigned int blocksize = dir->i_sb->s_blocksize;
1742 int csum_size = 0;
1743 int err;
1744
1745 if (ext4_has_metadata_csum(inode->i_sb))
1746 csum_size = sizeof(struct ext4_dir_entry_tail);
1747
1748 if (!de) {
1749 err = ext4_find_dest_de(dir, inode,
1750 bh, bh->b_data, blocksize - csum_size,
1751 name, namelen, &de);
1752 if (err)
1753 return err;
1754 }
1755 BUFFER_TRACE(bh, "get_write_access");
1756 err = ext4_journal_get_write_access(handle, bh);
1757 if (err) {
1758 ext4_std_error(dir->i_sb, err);
1759 return err;
1760 }
1761
1762 /* By now the buffer is marked for journaling. Due to crypto operations,
1763 * the following function call may fail */
1764 err = ext4_insert_dentry(dir, inode, de, blocksize, &dentry->d_name,
1765 name, namelen);
1766 if (err < 0)
1767 return err;
1768
1769 /*
1770 * XXX shouldn't update any times until successful
1771 * completion of syscall, but too many callers depend
1772 * on this.
1773 *
1774 * XXX similarly, too many callers depend on
1775 * ext4_new_inode() setting the times, but error
1776 * recovery deletes the inode, so the worst that can
1777 * happen is that the times are slightly out of date
1778 * and/or different from the directory change time.
1779 */
1780 dir->i_mtime = dir->i_ctime = ext4_current_time(dir);
1781 ext4_update_dx_flag(dir);
1782 dir->i_version++;
1783 ext4_mark_inode_dirty(handle, dir);
1784 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1785 err = ext4_handle_dirty_dirent_node(handle, dir, bh);
1786 if (err)
1787 ext4_std_error(dir->i_sb, err);
1788 return 0;
1789 }
1790
1791 /*
1792 * This converts a one block unindexed directory to a 3 block indexed
1793 * directory, and adds the dentry to the indexed directory.
1794 */
1795 static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
1796 struct inode *inode, struct buffer_head *bh)
1797 {
1798 struct inode *dir = dentry->d_parent->d_inode;
1799 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1800 struct ext4_fname_crypto_ctx *ctx = NULL;
1801 int res;
1802 #else
1803 const char *name = dentry->d_name.name;
1804 int namelen = dentry->d_name.len;
1805 #endif
1806 struct buffer_head *bh2;
1807 struct dx_root *root;
1808 struct dx_frame frames[2], *frame;
1809 struct dx_entry *entries;
1810 struct ext4_dir_entry_2 *de, *de2;
1811 struct ext4_dir_entry_tail *t;
1812 char *data1, *top;
1813 unsigned len;
1814 int retval;
1815 unsigned blocksize;
1816 struct dx_hash_info hinfo;
1817 ext4_lblk_t block;
1818 struct fake_dirent *fde;
1819 int csum_size = 0;
1820
1821 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1822 ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN);
1823 if (IS_ERR(ctx))
1824 return PTR_ERR(ctx);
1825 #endif
1826
1827 if (ext4_has_metadata_csum(inode->i_sb))
1828 csum_size = sizeof(struct ext4_dir_entry_tail);
1829
1830 blocksize = dir->i_sb->s_blocksize;
1831 dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
1832 BUFFER_TRACE(bh, "get_write_access");
1833 retval = ext4_journal_get_write_access(handle, bh);
1834 if (retval) {
1835 ext4_std_error(dir->i_sb, retval);
1836 brelse(bh);
1837 return retval;
1838 }
1839 root = (struct dx_root *) bh->b_data;
1840
1841 /* The 0th block becomes the root, move the dirents out */
1842 fde = &root->dotdot;
1843 de = (struct ext4_dir_entry_2 *)((char *)fde +
1844 ext4_rec_len_from_disk(fde->rec_len, blocksize));
1845 if ((char *) de >= (((char *) root) + blocksize)) {
1846 EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
1847 brelse(bh);
1848 return -EIO;
1849 }
1850 len = ((char *) root) + (blocksize - csum_size) - (char *) de;
1851
1852 /* Allocate new block for the 0th block's dirents */
1853 bh2 = ext4_append(handle, dir, &block);
1854 if (IS_ERR(bh2)) {
1855 brelse(bh);
1856 return PTR_ERR(bh2);
1857 }
1858 ext4_set_inode_flag(dir, EXT4_INODE_INDEX);
1859 data1 = bh2->b_data;
1860
1861 memcpy (data1, de, len);
1862 de = (struct ext4_dir_entry_2 *) data1;
1863 top = data1 + len;
1864 while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
1865 de = de2;
1866 de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
1867 (char *) de,
1868 blocksize);
1869
1870 if (csum_size) {
1871 t = EXT4_DIRENT_TAIL(data1, blocksize);
1872 initialize_dirent_tail(t, blocksize);
1873 }
1874
1875 /* Initialize the root; the dot dirents already exist */
1876 de = (struct ext4_dir_entry_2 *) (&root->dotdot);
1877 de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
1878 blocksize);
1879 memset (&root->info, 0, sizeof(root->info));
1880 root->info.info_length = sizeof(root->info);
1881 root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
1882 entries = root->entries;
1883 dx_set_block(entries, 1);
1884 dx_set_count(entries, 1);
1885 dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
1886
1887 /* Initialize as for dx_probe */
1888 hinfo.hash_version = root->info.hash_version;
1889 if (hinfo.hash_version <= DX_HASH_TEA)
1890 hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
1891 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
1892 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1893 res = ext4_fname_usr_to_hash(ctx, &dentry->d_name, &hinfo);
1894 if (res < 0) {
1895 ext4_put_fname_crypto_ctx(&ctx);
1896 ext4_mark_inode_dirty(handle, dir);
1897 brelse(bh);
1898 return res;
1899 }
1900 ext4_put_fname_crypto_ctx(&ctx);
1901 #else
1902 ext4fs_dirhash(name, namelen, &hinfo);
1903 #endif
1904 memset(frames, 0, sizeof(frames));
1905 frame = frames;
1906 frame->entries = entries;
1907 frame->at = entries;
1908 frame->bh = bh;
1909 bh = bh2;
1910
1911 retval = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
1912 if (retval)
1913 goto out_frames;
1914 retval = ext4_handle_dirty_dirent_node(handle, dir, bh);
1915 if (retval)
1916 goto out_frames;
1917
1918 de = do_split(handle,dir, &bh, frame, &hinfo);
1919 if (IS_ERR(de)) {
1920 retval = PTR_ERR(de);
1921 goto out_frames;
1922 }
1923 dx_release(frames);
1924
1925 retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
1926 brelse(bh);
1927 return retval;
1928 out_frames:
1929 /*
1930 * Even if the block split failed, we have to properly write
1931 * out all the changes we did so far. Otherwise we can end up
1932 * with corrupted filesystem.
1933 */
1934 ext4_mark_inode_dirty(handle, dir);
1935 dx_release(frames);
1936 return retval;
1937 }
1938
1939 /*
1940 * ext4_add_entry()
1941 *
1942 * adds a file entry to the specified directory, using the same
1943 * semantics as ext4_find_entry(). It returns NULL if it failed.
1944 *
1945 * NOTE!! The inode part of 'de' is left at 0 - which means you
1946 * may not sleep between calling this and putting something into
1947 * the entry, as someone else might have used it while you slept.
1948 */
1949 static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
1950 struct inode *inode)
1951 {
1952 struct inode *dir = dentry->d_parent->d_inode;
1953 struct buffer_head *bh = NULL;
1954 struct ext4_dir_entry_2 *de;
1955 struct ext4_dir_entry_tail *t;
1956 struct super_block *sb;
1957 int retval;
1958 int dx_fallback=0;
1959 unsigned blocksize;
1960 ext4_lblk_t block, blocks;
1961 int csum_size = 0;
1962
1963 if (ext4_has_metadata_csum(inode->i_sb))
1964 csum_size = sizeof(struct ext4_dir_entry_tail);
1965
1966 sb = dir->i_sb;
1967 blocksize = sb->s_blocksize;
1968 if (!dentry->d_name.len)
1969 return -EINVAL;
1970
1971 if (ext4_has_inline_data(dir)) {
1972 retval = ext4_try_add_inline_entry(handle, dentry, inode);
1973 if (retval < 0)
1974 return retval;
1975 if (retval == 1) {
1976 retval = 0;
1977 goto out;
1978 }
1979 }
1980
1981 if (is_dx(dir)) {
1982 retval = ext4_dx_add_entry(handle, dentry, inode);
1983 if (!retval || (retval != ERR_BAD_DX_DIR))
1984 goto out;
1985 ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
1986 dx_fallback++;
1987 ext4_mark_inode_dirty(handle, dir);
1988 }
1989 blocks = dir->i_size >> sb->s_blocksize_bits;
1990 for (block = 0; block < blocks; block++) {
1991 bh = ext4_read_dirblock(dir, block, DIRENT);
1992 if (IS_ERR(bh))
1993 return PTR_ERR(bh);
1994
1995 retval = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
1996 if (retval != -ENOSPC)
1997 goto out;
1998
1999 if (blocks == 1 && !dx_fallback &&
2000 EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX)) {
2001 retval = make_indexed_dir(handle, dentry, inode, bh);
2002 bh = NULL; /* make_indexed_dir releases bh */
2003 goto out;
2004 }
2005 brelse(bh);
2006 }
2007 bh = ext4_append(handle, dir, &block);
2008 if (IS_ERR(bh))
2009 return PTR_ERR(bh);
2010 de = (struct ext4_dir_entry_2 *) bh->b_data;
2011 de->inode = 0;
2012 de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize);
2013
2014 if (csum_size) {
2015 t = EXT4_DIRENT_TAIL(bh->b_data, blocksize);
2016 initialize_dirent_tail(t, blocksize);
2017 }
2018
2019 retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
2020 out:
2021 brelse(bh);
2022 if (retval == 0)
2023 ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY);
2024 return retval;
2025 }
2026
2027 /*
2028 * Returns 0 for success, or a negative error value
2029 */
2030 static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
2031 struct inode *inode)
2032 {
2033 struct dx_frame frames[2], *frame;
2034 struct dx_entry *entries, *at;
2035 struct dx_hash_info hinfo;
2036 struct buffer_head *bh;
2037 struct inode *dir = dentry->d_parent->d_inode;
2038 struct super_block *sb = dir->i_sb;
2039 struct ext4_dir_entry_2 *de;
2040 int err;
2041
2042 frame = dx_probe(&dentry->d_name, dir, &hinfo, frames);
2043 if (IS_ERR(frame))
2044 return PTR_ERR(frame);
2045 entries = frame->entries;
2046 at = frame->at;
2047 bh = ext4_read_dirblock(dir, dx_get_block(frame->at), DIRENT);
2048 if (IS_ERR(bh)) {
2049 err = PTR_ERR(bh);
2050 bh = NULL;
2051 goto cleanup;
2052 }
2053
2054 BUFFER_TRACE(bh, "get_write_access");
2055 err = ext4_journal_get_write_access(handle, bh);
2056 if (err)
2057 goto journal_error;
2058
2059 err = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
2060 if (err != -ENOSPC)
2061 goto cleanup;
2062
2063 /* Block full, should compress but for now just split */
2064 dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
2065 dx_get_count(entries), dx_get_limit(entries)));
2066 /* Need to split index? */
2067 if (dx_get_count(entries) == dx_get_limit(entries)) {
2068 ext4_lblk_t newblock;
2069 unsigned icount = dx_get_count(entries);
2070 int levels = frame - frames;
2071 struct dx_entry *entries2;
2072 struct dx_node *node2;
2073 struct buffer_head *bh2;
2074
2075 if (levels && (dx_get_count(frames->entries) ==
2076 dx_get_limit(frames->entries))) {
2077 ext4_warning(sb, "Directory index full!");
2078 err = -ENOSPC;
2079 goto cleanup;
2080 }
2081 bh2 = ext4_append(handle, dir, &newblock);
2082 if (IS_ERR(bh2)) {
2083 err = PTR_ERR(bh2);
2084 goto cleanup;
2085 }
2086 node2 = (struct dx_node *)(bh2->b_data);
2087 entries2 = node2->entries;
2088 memset(&node2->fake, 0, sizeof(struct fake_dirent));
2089 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
2090 sb->s_blocksize);
2091 BUFFER_TRACE(frame->bh, "get_write_access");
2092 err = ext4_journal_get_write_access(handle, frame->bh);
2093 if (err)
2094 goto journal_error;
2095 if (levels) {
2096 unsigned icount1 = icount/2, icount2 = icount - icount1;
2097 unsigned hash2 = dx_get_hash(entries + icount1);
2098 dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
2099 icount1, icount2));
2100
2101 BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
2102 err = ext4_journal_get_write_access(handle,
2103 frames[0].bh);
2104 if (err)
2105 goto journal_error;
2106
2107 memcpy((char *) entries2, (char *) (entries + icount1),
2108 icount2 * sizeof(struct dx_entry));
2109 dx_set_count(entries, icount1);
2110 dx_set_count(entries2, icount2);
2111 dx_set_limit(entries2, dx_node_limit(dir));
2112
2113 /* Which index block gets the new entry? */
2114 if (at - entries >= icount1) {
2115 frame->at = at = at - entries - icount1 + entries2;
2116 frame->entries = entries = entries2;
2117 swap(frame->bh, bh2);
2118 }
2119 dx_insert_block(frames + 0, hash2, newblock);
2120 dxtrace(dx_show_index("node", frames[1].entries));
2121 dxtrace(dx_show_index("node",
2122 ((struct dx_node *) bh2->b_data)->entries));
2123 err = ext4_handle_dirty_dx_node(handle, dir, bh2);
2124 if (err)
2125 goto journal_error;
2126 brelse (bh2);
2127 } else {
2128 dxtrace(printk(KERN_DEBUG
2129 "Creating second level index...\n"));
2130 memcpy((char *) entries2, (char *) entries,
2131 icount * sizeof(struct dx_entry));
2132 dx_set_limit(entries2, dx_node_limit(dir));
2133
2134 /* Set up root */
2135 dx_set_count(entries, 1);
2136 dx_set_block(entries + 0, newblock);
2137 ((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels = 1;
2138
2139 /* Add new access path frame */
2140 frame = frames + 1;
2141 frame->at = at = at - entries + entries2;
2142 frame->entries = entries = entries2;
2143 frame->bh = bh2;
2144 err = ext4_journal_get_write_access(handle,
2145 frame->bh);
2146 if (err)
2147 goto journal_error;
2148 }
2149 err = ext4_handle_dirty_dx_node(handle, dir, frames[0].bh);
2150 if (err) {
2151 ext4_std_error(inode->i_sb, err);
2152 goto cleanup;
2153 }
2154 }
2155 de = do_split(handle, dir, &bh, frame, &hinfo);
2156 if (IS_ERR(de)) {
2157 err = PTR_ERR(de);
2158 goto cleanup;
2159 }
2160 err = add_dirent_to_buf(handle, dentry, inode, de, bh);
2161 goto cleanup;
2162
2163 journal_error:
2164 ext4_std_error(dir->i_sb, err);
2165 cleanup:
2166 brelse(bh);
2167 dx_release(frames);
2168 return err;
2169 }
2170
2171 /*
2172 * ext4_generic_delete_entry deletes a directory entry by merging it
2173 * with the previous entry
2174 */
2175 int ext4_generic_delete_entry(handle_t *handle,
2176 struct inode *dir,
2177 struct ext4_dir_entry_2 *de_del,
2178 struct buffer_head *bh,
2179 void *entry_buf,
2180 int buf_size,
2181 int csum_size)
2182 {
2183 struct ext4_dir_entry_2 *de, *pde;
2184 unsigned int blocksize = dir->i_sb->s_blocksize;
2185 int i;
2186
2187 i = 0;
2188 pde = NULL;
2189 de = (struct ext4_dir_entry_2 *)entry_buf;
2190 while (i < buf_size - csum_size) {
2191 if (ext4_check_dir_entry(dir, NULL, de, bh,
2192 bh->b_data, bh->b_size, i))
2193 return -EIO;
2194 if (de == de_del) {
2195 if (pde)
2196 pde->rec_len = ext4_rec_len_to_disk(
2197 ext4_rec_len_from_disk(pde->rec_len,
2198 blocksize) +
2199 ext4_rec_len_from_disk(de->rec_len,
2200 blocksize),
2201 blocksize);
2202 else
2203 de->inode = 0;
2204 dir->i_version++;
2205 return 0;
2206 }
2207 i += ext4_rec_len_from_disk(de->rec_len, blocksize);
2208 pde = de;
2209 de = ext4_next_entry(de, blocksize);
2210 }
2211 return -ENOENT;
2212 }
2213
2214 static int ext4_delete_entry(handle_t *handle,
2215 struct inode *dir,
2216 struct ext4_dir_entry_2 *de_del,
2217 struct buffer_head *bh)
2218 {
2219 int err, csum_size = 0;
2220
2221 if (ext4_has_inline_data(dir)) {
2222 int has_inline_data = 1;
2223 err = ext4_delete_inline_entry(handle, dir, de_del, bh,
2224 &has_inline_data);
2225 if (has_inline_data)
2226 return err;
2227 }
2228
2229 if (ext4_has_metadata_csum(dir->i_sb))
2230 csum_size = sizeof(struct ext4_dir_entry_tail);
2231
2232 BUFFER_TRACE(bh, "get_write_access");
2233 err = ext4_journal_get_write_access(handle, bh);
2234 if (unlikely(err))
2235 goto out;
2236
2237 err = ext4_generic_delete_entry(handle, dir, de_del,
2238 bh, bh->b_data,
2239 dir->i_sb->s_blocksize, csum_size);
2240 if (err)
2241 goto out;
2242
2243 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
2244 err = ext4_handle_dirty_dirent_node(handle, dir, bh);
2245 if (unlikely(err))
2246 goto out;
2247
2248 return 0;
2249 out:
2250 if (err != -ENOENT)
2251 ext4_std_error(dir->i_sb, err);
2252 return err;
2253 }
2254
2255 /*
2256 * DIR_NLINK feature is set if 1) nlinks > EXT4_LINK_MAX or 2) nlinks == 2,
2257 * since this indicates that nlinks count was previously 1.
2258 */
2259 static void ext4_inc_count(handle_t *handle, struct inode *inode)
2260 {
2261 inc_nlink(inode);
2262 if (is_dx(inode) && inode->i_nlink > 1) {
2263 /* limit is 16-bit i_links_count */
2264 if (inode->i_nlink >= EXT4_LINK_MAX || inode->i_nlink == 2) {
2265 set_nlink(inode, 1);
2266 EXT4_SET_RO_COMPAT_FEATURE(inode->i_sb,
2267 EXT4_FEATURE_RO_COMPAT_DIR_NLINK);
2268 }
2269 }
2270 }
2271
2272 /*
2273 * If a directory had nlink == 1, then we should let it be 1. This indicates
2274 * directory has >EXT4_LINK_MAX subdirs.
2275 */
2276 static void ext4_dec_count(handle_t *handle, struct inode *inode)
2277 {
2278 if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
2279 drop_nlink(inode);
2280 }
2281
2282
2283 static int ext4_add_nondir(handle_t *handle,
2284 struct dentry *dentry, struct inode *inode)
2285 {
2286 int err = ext4_add_entry(handle, dentry, inode);
2287 if (!err) {
2288 ext4_mark_inode_dirty(handle, inode);
2289 unlock_new_inode(inode);
2290 d_instantiate(dentry, inode);
2291 return 0;
2292 }
2293 drop_nlink(inode);
2294 unlock_new_inode(inode);
2295 iput(inode);
2296 return err;
2297 }
2298
2299 /*
2300 * By the time this is called, we already have created
2301 * the directory cache entry for the new file, but it
2302 * is so far negative - it has no inode.
2303 *
2304 * If the create succeeds, we fill in the inode information
2305 * with d_instantiate().
2306 */
2307 static int ext4_create(struct inode *dir, struct dentry *dentry, umode_t mode,
2308 bool excl)
2309 {
2310 handle_t *handle;
2311 struct inode *inode;
2312 int err, credits, retries = 0;
2313
2314 dquot_initialize(dir);
2315
2316 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2317 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2318 retry:
2319 inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
2320 NULL, EXT4_HT_DIR, credits);
2321 handle = ext4_journal_current_handle();
2322 err = PTR_ERR(inode);
2323 if (!IS_ERR(inode)) {
2324 inode->i_op = &ext4_file_inode_operations;
2325 if (test_opt(inode->i_sb, DAX))
2326 inode->i_fop = &ext4_dax_file_operations;
2327 else
2328 inode->i_fop = &ext4_file_operations;
2329 ext4_set_aops(inode);
2330 err = 0;
2331 #ifdef CONFIG_EXT4_FS_ENCRYPTION
2332 if (!err && ext4_encrypted_inode(dir)) {
2333 err = ext4_inherit_context(dir, inode);
2334 if (err) {
2335 clear_nlink(inode);
2336 unlock_new_inode(inode);
2337 iput(inode);
2338 }
2339 }
2340 #endif
2341 if (!err)
2342 err = ext4_add_nondir(handle, dentry, inode);
2343 if (!err && IS_DIRSYNC(dir))
2344 ext4_handle_sync(handle);
2345 }
2346 if (handle)
2347 ext4_journal_stop(handle);
2348 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2349 goto retry;
2350 return err;
2351 }
2352
2353 static int ext4_mknod(struct inode *dir, struct dentry *dentry,
2354 umode_t mode, dev_t rdev)
2355 {
2356 handle_t *handle;
2357 struct inode *inode;
2358 int err, credits, retries = 0;
2359
2360 if (!new_valid_dev(rdev))
2361 return -EINVAL;
2362
2363 dquot_initialize(dir);
2364
2365 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2366 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2367 retry:
2368 inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
2369 NULL, EXT4_HT_DIR, credits);
2370 handle = ext4_journal_current_handle();
2371 err = PTR_ERR(inode);
2372 if (!IS_ERR(inode)) {
2373 init_special_inode(inode, inode->i_mode, rdev);
2374 inode->i_op = &ext4_special_inode_operations;
2375 err = ext4_add_nondir(handle, dentry, inode);
2376 if (!err && IS_DIRSYNC(dir))
2377 ext4_handle_sync(handle);
2378 }
2379 if (handle)
2380 ext4_journal_stop(handle);
2381 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2382 goto retry;
2383 return err;
2384 }
2385
2386 static int ext4_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
2387 {
2388 handle_t *handle;
2389 struct inode *inode;
2390 int err, retries = 0;
2391
2392 dquot_initialize(dir);
2393
2394 retry:
2395 inode = ext4_new_inode_start_handle(dir, mode,
2396 NULL, 0, NULL,
2397 EXT4_HT_DIR,
2398 EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
2399 4 + EXT4_XATTR_TRANS_BLOCKS);
2400 handle = ext4_journal_current_handle();
2401 err = PTR_ERR(inode);
2402 if (!IS_ERR(inode)) {
2403 inode->i_op = &ext4_file_inode_operations;
2404 if (test_opt(inode->i_sb, DAX))
2405 inode->i_fop = &ext4_dax_file_operations;
2406 else
2407 inode->i_fop = &ext4_file_operations;
2408 ext4_set_aops(inode);
2409 d_tmpfile(dentry, inode);
2410 err = ext4_orphan_add(handle, inode);
2411 if (err)
2412 goto err_unlock_inode;
2413 mark_inode_dirty(inode);
2414 unlock_new_inode(inode);
2415 }
2416 if (handle)
2417 ext4_journal_stop(handle);
2418 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2419 goto retry;
2420 return err;
2421 err_unlock_inode:
2422 ext4_journal_stop(handle);
2423 unlock_new_inode(inode);
2424 return err;
2425 }
2426
2427 struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
2428 struct ext4_dir_entry_2 *de,
2429 int blocksize, int csum_size,
2430 unsigned int parent_ino, int dotdot_real_len)
2431 {
2432 de->inode = cpu_to_le32(inode->i_ino);
2433 de->name_len = 1;
2434 de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
2435 blocksize);
2436 strcpy(de->name, ".");
2437 ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2438
2439 de = ext4_next_entry(de, blocksize);
2440 de->inode = cpu_to_le32(parent_ino);
2441 de->name_len = 2;
2442 if (!dotdot_real_len)
2443 de->rec_len = ext4_rec_len_to_disk(blocksize -
2444 (csum_size + EXT4_DIR_REC_LEN(1)),
2445 blocksize);
2446 else
2447 de->rec_len = ext4_rec_len_to_disk(
2448 EXT4_DIR_REC_LEN(de->name_len), blocksize);
2449 strcpy(de->name, "..");
2450 ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2451
2452 return ext4_next_entry(de, blocksize);
2453 }
2454
2455 static int ext4_init_new_dir(handle_t *handle, struct inode *dir,
2456 struct inode *inode)
2457 {
2458 struct buffer_head *dir_block = NULL;
2459 struct ext4_dir_entry_2 *de;
2460 struct ext4_dir_entry_tail *t;
2461 ext4_lblk_t block = 0;
2462 unsigned int blocksize = dir->i_sb->s_blocksize;
2463 int csum_size = 0;
2464 int err;
2465
2466 if (ext4_has_metadata_csum(dir->i_sb))
2467 csum_size = sizeof(struct ext4_dir_entry_tail);
2468
2469 if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
2470 err = ext4_try_create_inline_dir(handle, dir, inode);
2471 if (err < 0 && err != -ENOSPC)
2472 goto out;
2473 if (!err)
2474 goto out;
2475 }
2476
2477 inode->i_size = 0;
2478 dir_block = ext4_append(handle, inode, &block);
2479 if (IS_ERR(dir_block))
2480 return PTR_ERR(dir_block);
2481 de = (struct ext4_dir_entry_2 *)dir_block->b_data;
2482 ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0);
2483 set_nlink(inode, 2);
2484 if (csum_size) {
2485 t = EXT4_DIRENT_TAIL(dir_block->b_data, blocksize);
2486 initialize_dirent_tail(t, blocksize);
2487 }
2488
2489 BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
2490 err = ext4_handle_dirty_dirent_node(handle, inode, dir_block);
2491 if (err)
2492 goto out;
2493 set_buffer_verified(dir_block);
2494 out:
2495 brelse(dir_block);
2496 return err;
2497 }
2498
2499 static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
2500 {
2501 handle_t *handle;
2502 struct inode *inode;
2503 int err, credits, retries = 0;
2504
2505 if (EXT4_DIR_LINK_MAX(dir))
2506 return -EMLINK;
2507
2508 dquot_initialize(dir);
2509
2510 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2511 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2512 retry:
2513 inode = ext4_new_inode_start_handle(dir, S_IFDIR | mode,
2514 &dentry->d_name,
2515 0, NULL, EXT4_HT_DIR, credits);
2516 handle = ext4_journal_current_handle();
2517 err = PTR_ERR(inode);
2518 if (IS_ERR(inode))
2519 goto out_stop;
2520
2521 inode->i_op = &ext4_dir_inode_operations;
2522 inode->i_fop = &ext4_dir_operations;
2523 err = ext4_init_new_dir(handle, dir, inode);
2524 if (err)
2525 goto out_clear_inode;
2526 #ifdef CONFIG_EXT4_FS_ENCRYPTION
2527 if (ext4_encrypted_inode(dir)) {
2528 err = ext4_inherit_context(dir, inode);
2529 if (err)
2530 goto out_clear_inode;
2531 }
2532 #endif
2533 err = ext4_mark_inode_dirty(handle, inode);
2534 if (!err)
2535 err = ext4_add_entry(handle, dentry, inode);
2536 if (err) {
2537 out_clear_inode:
2538 clear_nlink(inode);
2539 unlock_new_inode(inode);
2540 ext4_mark_inode_dirty(handle, inode);
2541 iput(inode);
2542 goto out_stop;
2543 }
2544 ext4_inc_count(handle, dir);
2545 ext4_update_dx_flag(dir);
2546 err = ext4_mark_inode_dirty(handle, dir);
2547 if (err)
2548 goto out_clear_inode;
2549 unlock_new_inode(inode);
2550 d_instantiate(dentry, inode);
2551 if (IS_DIRSYNC(dir))
2552 ext4_handle_sync(handle);
2553
2554 out_stop:
2555 if (handle)
2556 ext4_journal_stop(handle);
2557 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2558 goto retry;
2559 return err;
2560 }
2561
2562 /*
2563 * routine to check that the specified directory is empty (for rmdir)
2564 */
2565 int ext4_empty_dir(struct inode *inode)
2566 {
2567 unsigned int offset;
2568 struct buffer_head *bh;
2569 struct ext4_dir_entry_2 *de, *de1;
2570 struct super_block *sb;
2571 int err = 0;
2572
2573 if (ext4_has_inline_data(inode)) {
2574 int has_inline_data = 1;
2575
2576 err = empty_inline_dir(inode, &has_inline_data);
2577 if (has_inline_data)
2578 return err;
2579 }
2580
2581 sb = inode->i_sb;
2582 if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2)) {
2583 EXT4_ERROR_INODE(inode, "invalid size");
2584 return 1;
2585 }
2586 bh = ext4_read_dirblock(inode, 0, EITHER);
2587 if (IS_ERR(bh))
2588 return 1;
2589
2590 de = (struct ext4_dir_entry_2 *) bh->b_data;
2591 de1 = ext4_next_entry(de, sb->s_blocksize);
2592 if (le32_to_cpu(de->inode) != inode->i_ino ||
2593 !le32_to_cpu(de1->inode) ||
2594 strcmp(".", de->name) ||
2595 strcmp("..", de1->name)) {
2596 ext4_warning(inode->i_sb,
2597 "bad directory (dir #%lu) - no `.' or `..'",
2598 inode->i_ino);
2599 brelse(bh);
2600 return 1;
2601 }
2602 offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) +
2603 ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize);
2604 de = ext4_next_entry(de1, sb->s_blocksize);
2605 while (offset < inode->i_size) {
2606 if ((void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
2607 unsigned int lblock;
2608 err = 0;
2609 brelse(bh);
2610 lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb);
2611 bh = ext4_read_dirblock(inode, lblock, EITHER);
2612 if (IS_ERR(bh))
2613 return 1;
2614 de = (struct ext4_dir_entry_2 *) bh->b_data;
2615 }
2616 if (ext4_check_dir_entry(inode, NULL, de, bh,
2617 bh->b_data, bh->b_size, offset)) {
2618 de = (struct ext4_dir_entry_2 *)(bh->b_data +
2619 sb->s_blocksize);
2620 offset = (offset | (sb->s_blocksize - 1)) + 1;
2621 continue;
2622 }
2623 if (le32_to_cpu(de->inode)) {
2624 brelse(bh);
2625 return 0;
2626 }
2627 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
2628 de = ext4_next_entry(de, sb->s_blocksize);
2629 }
2630 brelse(bh);
2631 return 1;
2632 }
2633
2634 /*
2635 * ext4_orphan_add() links an unlinked or truncated inode into a list of
2636 * such inodes, starting at the superblock, in case we crash before the
2637 * file is closed/deleted, or in case the inode truncate spans multiple
2638 * transactions and the last transaction is not recovered after a crash.
2639 *
2640 * At filesystem recovery time, we walk this list deleting unlinked
2641 * inodes and truncating linked inodes in ext4_orphan_cleanup().
2642 *
2643 * Orphan list manipulation functions must be called under i_mutex unless
2644 * we are just creating the inode or deleting it.
2645 */
2646 int ext4_orphan_add(handle_t *handle, struct inode *inode)
2647 {
2648 struct super_block *sb = inode->i_sb;
2649 struct ext4_sb_info *sbi = EXT4_SB(sb);
2650 struct ext4_iloc iloc;
2651 int err = 0, rc;
2652 bool dirty = false;
2653
2654 if (!sbi->s_journal || is_bad_inode(inode))
2655 return 0;
2656
2657 WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
2658 !mutex_is_locked(&inode->i_mutex));
2659 /*
2660 * Exit early if inode already is on orphan list. This is a big speedup
2661 * since we don't have to contend on the global s_orphan_lock.
2662 */
2663 if (!list_empty(&EXT4_I(inode)->i_orphan))
2664 return 0;
2665
2666 /*
2667 * Orphan handling is only valid for files with data blocks
2668 * being truncated, or files being unlinked. Note that we either
2669 * hold i_mutex, or the inode can not be referenced from outside,
2670 * so i_nlink should not be bumped due to race
2671 */
2672 J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2673 S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
2674
2675 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2676 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2677 if (err)
2678 goto out;
2679
2680 err = ext4_reserve_inode_write(handle, inode, &iloc);
2681 if (err)
2682 goto out;
2683
2684 mutex_lock(&sbi->s_orphan_lock);
2685 /*
2686 * Due to previous errors inode may be already a part of on-disk
2687 * orphan list. If so skip on-disk list modification.
2688 */
2689 if (!NEXT_ORPHAN(inode) || NEXT_ORPHAN(inode) >
2690 (le32_to_cpu(sbi->s_es->s_inodes_count))) {
2691 /* Insert this inode at the head of the on-disk orphan list */
2692 NEXT_ORPHAN(inode) = le32_to_cpu(sbi->s_es->s_last_orphan);
2693 sbi->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
2694 dirty = true;
2695 }
2696 list_add(&EXT4_I(inode)->i_orphan, &sbi->s_orphan);
2697 mutex_unlock(&sbi->s_orphan_lock);
2698
2699 if (dirty) {
2700 err = ext4_handle_dirty_super(handle, sb);
2701 rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
2702 if (!err)
2703 err = rc;
2704 if (err) {
2705 /*
2706 * We have to remove inode from in-memory list if
2707 * addition to on disk orphan list failed. Stray orphan
2708 * list entries can cause panics at unmount time.
2709 */
2710 mutex_lock(&sbi->s_orphan_lock);
2711 list_del(&EXT4_I(inode)->i_orphan);
2712 mutex_unlock(&sbi->s_orphan_lock);
2713 }
2714 }
2715 jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
2716 jbd_debug(4, "orphan inode %lu will point to %d\n",
2717 inode->i_ino, NEXT_ORPHAN(inode));
2718 out:
2719 ext4_std_error(sb, err);
2720 return err;
2721 }
2722
2723 /*
2724 * ext4_orphan_del() removes an unlinked or truncated inode from the list
2725 * of such inodes stored on disk, because it is finally being cleaned up.
2726 */
2727 int ext4_orphan_del(handle_t *handle, struct inode *inode)
2728 {
2729 struct list_head *prev;
2730 struct ext4_inode_info *ei = EXT4_I(inode);
2731 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2732 __u32 ino_next;
2733 struct ext4_iloc iloc;
2734 int err = 0;
2735
2736 if (!sbi->s_journal && !(sbi->s_mount_state & EXT4_ORPHAN_FS))
2737 return 0;
2738
2739 WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
2740 !mutex_is_locked(&inode->i_mutex));
2741 /* Do this quick check before taking global s_orphan_lock. */
2742 if (list_empty(&ei->i_orphan))
2743 return 0;
2744
2745 if (handle) {
2746 /* Grab inode buffer early before taking global s_orphan_lock */
2747 err = ext4_reserve_inode_write(handle, inode, &iloc);
2748 }
2749
2750 mutex_lock(&sbi->s_orphan_lock);
2751 jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
2752
2753 prev = ei->i_orphan.prev;
2754 list_del_init(&ei->i_orphan);
2755
2756 /* If we're on an error path, we may not have a valid
2757 * transaction handle with which to update the orphan list on
2758 * disk, but we still need to remove the inode from the linked
2759 * list in memory. */
2760 if (!handle || err) {
2761 mutex_unlock(&sbi->s_orphan_lock);
2762 goto out_err;
2763 }
2764
2765 ino_next = NEXT_ORPHAN(inode);
2766 if (prev == &sbi->s_orphan) {
2767 jbd_debug(4, "superblock will point to %u\n", ino_next);
2768 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2769 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2770 if (err) {
2771 mutex_unlock(&sbi->s_orphan_lock);
2772 goto out_brelse;
2773 }
2774 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
2775 mutex_unlock(&sbi->s_orphan_lock);
2776 err = ext4_handle_dirty_super(handle, inode->i_sb);
2777 } else {
2778 struct ext4_iloc iloc2;
2779 struct inode *i_prev =
2780 &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
2781
2782 jbd_debug(4, "orphan inode %lu will point to %u\n",
2783 i_prev->i_ino, ino_next);
2784 err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
2785 if (err) {
2786 mutex_unlock(&sbi->s_orphan_lock);
2787 goto out_brelse;
2788 }
2789 NEXT_ORPHAN(i_prev) = ino_next;
2790 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
2791 mutex_unlock(&sbi->s_orphan_lock);
2792 }
2793 if (err)
2794 goto out_brelse;
2795 NEXT_ORPHAN(inode) = 0;
2796 err = ext4_mark_iloc_dirty(handle, inode, &iloc);
2797 out_err:
2798 ext4_std_error(inode->i_sb, err);
2799 return err;
2800
2801 out_brelse:
2802 brelse(iloc.bh);
2803 goto out_err;
2804 }
2805
2806 static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
2807 {
2808 int retval;
2809 struct inode *inode;
2810 struct buffer_head *bh;
2811 struct ext4_dir_entry_2 *de;
2812 handle_t *handle = NULL;
2813
2814 /* Initialize quotas before so that eventual writes go in
2815 * separate transaction */
2816 dquot_initialize(dir);
2817 dquot_initialize(dentry->d_inode);
2818
2819 retval = -ENOENT;
2820 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
2821 if (IS_ERR(bh))
2822 return PTR_ERR(bh);
2823 if (!bh)
2824 goto end_rmdir;
2825
2826 inode = dentry->d_inode;
2827
2828 retval = -EIO;
2829 if (le32_to_cpu(de->inode) != inode->i_ino)
2830 goto end_rmdir;
2831
2832 retval = -ENOTEMPTY;
2833 if (!ext4_empty_dir(inode))
2834 goto end_rmdir;
2835
2836 handle = ext4_journal_start(dir, EXT4_HT_DIR,
2837 EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
2838 if (IS_ERR(handle)) {
2839 retval = PTR_ERR(handle);
2840 handle = NULL;
2841 goto end_rmdir;
2842 }
2843
2844 if (IS_DIRSYNC(dir))
2845 ext4_handle_sync(handle);
2846
2847 retval = ext4_delete_entry(handle, dir, de, bh);
2848 if (retval)
2849 goto end_rmdir;
2850 if (!EXT4_DIR_LINK_EMPTY(inode))
2851 ext4_warning(inode->i_sb,
2852 "empty directory has too many links (%d)",
2853 inode->i_nlink);
2854 inode->i_version++;
2855 clear_nlink(inode);
2856 /* There's no need to set i_disksize: the fact that i_nlink is
2857 * zero will ensure that the right thing happens during any
2858 * recovery. */
2859 inode->i_size = 0;
2860 ext4_orphan_add(handle, inode);
2861 inode->i_ctime = dir->i_ctime = dir->i_mtime = ext4_current_time(inode);
2862 ext4_mark_inode_dirty(handle, inode);
2863 ext4_dec_count(handle, dir);
2864 ext4_update_dx_flag(dir);
2865 ext4_mark_inode_dirty(handle, dir);
2866
2867 end_rmdir:
2868 brelse(bh);
2869 if (handle)
2870 ext4_journal_stop(handle);
2871 return retval;
2872 }
2873
2874 static int ext4_unlink(struct inode *dir, struct dentry *dentry)
2875 {
2876 int retval;
2877 struct inode *inode;
2878 struct buffer_head *bh;
2879 struct ext4_dir_entry_2 *de;
2880 handle_t *handle = NULL;
2881
2882 trace_ext4_unlink_enter(dir, dentry);
2883 /* Initialize quotas before so that eventual writes go
2884 * in separate transaction */
2885 dquot_initialize(dir);
2886 dquot_initialize(dentry->d_inode);
2887
2888 retval = -ENOENT;
2889 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
2890 if (IS_ERR(bh))
2891 return PTR_ERR(bh);
2892 if (!bh)
2893 goto end_unlink;
2894
2895 inode = dentry->d_inode;
2896
2897 retval = -EIO;
2898 if (le32_to_cpu(de->inode) != inode->i_ino)
2899 goto end_unlink;
2900
2901 handle = ext4_journal_start(dir, EXT4_HT_DIR,
2902 EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
2903 if (IS_ERR(handle)) {
2904 retval = PTR_ERR(handle);
2905 handle = NULL;
2906 goto end_unlink;
2907 }
2908
2909 if (IS_DIRSYNC(dir))
2910 ext4_handle_sync(handle);
2911
2912 if (!inode->i_nlink) {
2913 ext4_warning(inode->i_sb,
2914 "Deleting nonexistent file (%lu), %d",
2915 inode->i_ino, inode->i_nlink);
2916 set_nlink(inode, 1);
2917 }
2918 retval = ext4_delete_entry(handle, dir, de, bh);
2919 if (retval)
2920 goto end_unlink;
2921 dir->i_ctime = dir->i_mtime = ext4_current_time(dir);
2922 ext4_update_dx_flag(dir);
2923 ext4_mark_inode_dirty(handle, dir);
2924 drop_nlink(inode);
2925 if (!inode->i_nlink)
2926 ext4_orphan_add(handle, inode);
2927 inode->i_ctime = ext4_current_time(inode);
2928 ext4_mark_inode_dirty(handle, inode);
2929
2930 end_unlink:
2931 brelse(bh);
2932 if (handle)
2933 ext4_journal_stop(handle);
2934 trace_ext4_unlink_exit(dentry, retval);
2935 return retval;
2936 }
2937
2938 static int ext4_symlink(struct inode *dir,
2939 struct dentry *dentry, const char *symname)
2940 {
2941 handle_t *handle;
2942 struct inode *inode;
2943 int l, err, retries = 0;
2944 int credits;
2945
2946 l = strlen(symname)+1;
2947 if (l > dir->i_sb->s_blocksize)
2948 return -ENAMETOOLONG;
2949
2950 dquot_initialize(dir);
2951
2952 if (l > EXT4_N_BLOCKS * 4) {
2953 /*
2954 * For non-fast symlinks, we just allocate inode and put it on
2955 * orphan list in the first transaction => we need bitmap,
2956 * group descriptor, sb, inode block, quota blocks, and
2957 * possibly selinux xattr blocks.
2958 */
2959 credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
2960 EXT4_XATTR_TRANS_BLOCKS;
2961 } else {
2962 /*
2963 * Fast symlink. We have to add entry to directory
2964 * (EXT4_DATA_TRANS_BLOCKS + EXT4_INDEX_EXTRA_TRANS_BLOCKS),
2965 * allocate new inode (bitmap, group descriptor, inode block,
2966 * quota blocks, sb is already counted in previous macros).
2967 */
2968 credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2969 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3;
2970 }
2971 retry:
2972 inode = ext4_new_inode_start_handle(dir, S_IFLNK|S_IRWXUGO,
2973 &dentry->d_name, 0, NULL,
2974 EXT4_HT_DIR, credits);
2975 handle = ext4_journal_current_handle();
2976 err = PTR_ERR(inode);
2977 if (IS_ERR(inode))
2978 goto out_stop;
2979
2980 if (l > EXT4_N_BLOCKS * 4) {
2981 inode->i_op = &ext4_symlink_inode_operations;
2982 ext4_set_aops(inode);
2983 /*
2984 * We cannot call page_symlink() with transaction started
2985 * because it calls into ext4_write_begin() which can wait
2986 * for transaction commit if we are running out of space
2987 * and thus we deadlock. So we have to stop transaction now
2988 * and restart it when symlink contents is written.
2989 *
2990 * To keep fs consistent in case of crash, we have to put inode
2991 * to orphan list in the mean time.
2992 */
2993 drop_nlink(inode);
2994 err = ext4_orphan_add(handle, inode);
2995 ext4_journal_stop(handle);
2996 if (err)
2997 goto err_drop_inode;
2998 err = __page_symlink(inode, symname, l, 1);
2999 if (err)
3000 goto err_drop_inode;
3001 /*
3002 * Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS
3003 * + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified
3004 */
3005 handle = ext4_journal_start(dir, EXT4_HT_DIR,
3006 EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3007 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1);
3008 if (IS_ERR(handle)) {
3009 err = PTR_ERR(handle);
3010 goto err_drop_inode;
3011 }
3012 set_nlink(inode, 1);
3013 err = ext4_orphan_del(handle, inode);
3014 if (err) {
3015 ext4_journal_stop(handle);
3016 clear_nlink(inode);
3017 goto err_drop_inode;
3018 }
3019 } else {
3020 /* clear the extent format for fast symlink */
3021 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
3022 inode->i_op = &ext4_fast_symlink_inode_operations;
3023 memcpy((char *)&EXT4_I(inode)->i_data, symname, l);
3024 inode->i_size = l-1;
3025 }
3026 EXT4_I(inode)->i_disksize = inode->i_size;
3027 err = ext4_add_nondir(handle, dentry, inode);
3028 if (!err && IS_DIRSYNC(dir))
3029 ext4_handle_sync(handle);
3030
3031 out_stop:
3032 if (handle)
3033 ext4_journal_stop(handle);
3034 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
3035 goto retry;
3036 return err;
3037 err_drop_inode:
3038 unlock_new_inode(inode);
3039 iput(inode);
3040 return err;
3041 }
3042
3043 static int ext4_link(struct dentry *old_dentry,
3044 struct inode *dir, struct dentry *dentry)
3045 {
3046 handle_t *handle;
3047 struct inode *inode = old_dentry->d_inode;
3048 int err, retries = 0;
3049
3050 if (inode->i_nlink >= EXT4_LINK_MAX)
3051 return -EMLINK;
3052 if (ext4_encrypted_inode(dir) &&
3053 !ext4_is_child_context_consistent_with_parent(dir, inode))
3054 return -EPERM;
3055 dquot_initialize(dir);
3056
3057 retry:
3058 handle = ext4_journal_start(dir, EXT4_HT_DIR,
3059 (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3060 EXT4_INDEX_EXTRA_TRANS_BLOCKS) + 1);
3061 if (IS_ERR(handle))
3062 return PTR_ERR(handle);
3063
3064 if (IS_DIRSYNC(dir))
3065 ext4_handle_sync(handle);
3066
3067 inode->i_ctime = ext4_current_time(inode);
3068 ext4_inc_count(handle, inode);
3069 ihold(inode);
3070
3071 err = ext4_add_entry(handle, dentry, inode);
3072 if (!err) {
3073 ext4_mark_inode_dirty(handle, inode);
3074 /* this can happen only for tmpfile being
3075 * linked the first time
3076 */
3077 if (inode->i_nlink == 1)
3078 ext4_orphan_del(handle, inode);
3079 d_instantiate(dentry, inode);
3080 } else {
3081 drop_nlink(inode);
3082 iput(inode);
3083 }
3084 ext4_journal_stop(handle);
3085 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
3086 goto retry;
3087 return err;
3088 }
3089
3090
3091 /*
3092 * Try to find buffer head where contains the parent block.
3093 * It should be the inode block if it is inlined or the 1st block
3094 * if it is a normal dir.
3095 */
3096 static struct buffer_head *ext4_get_first_dir_block(handle_t *handle,
3097 struct inode *inode,
3098 int *retval,
3099 struct ext4_dir_entry_2 **parent_de,
3100 int *inlined)
3101 {
3102 struct buffer_head *bh;
3103
3104 if (!ext4_has_inline_data(inode)) {
3105 bh = ext4_read_dirblock(inode, 0, EITHER);
3106 if (IS_ERR(bh)) {
3107 *retval = PTR_ERR(bh);
3108 return NULL;
3109 }
3110 *parent_de = ext4_next_entry(
3111 (struct ext4_dir_entry_2 *)bh->b_data,
3112 inode->i_sb->s_blocksize);
3113 return bh;
3114 }
3115
3116 *inlined = 1;
3117 return ext4_get_first_inline_block(inode, parent_de, retval);
3118 }
3119
3120 struct ext4_renament {
3121 struct inode *dir;
3122 struct dentry *dentry;
3123 struct inode *inode;
3124 bool is_dir;
3125 int dir_nlink_delta;
3126
3127 /* entry for "dentry" */
3128 struct buffer_head *bh;
3129 struct ext4_dir_entry_2 *de;
3130 int inlined;
3131
3132 /* entry for ".." in inode if it's a directory */
3133 struct buffer_head *dir_bh;
3134 struct ext4_dir_entry_2 *parent_de;
3135 int dir_inlined;
3136 };
3137
3138 static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent)
3139 {
3140 int retval;
3141
3142 ent->dir_bh = ext4_get_first_dir_block(handle, ent->inode,
3143 &retval, &ent->parent_de,
3144 &ent->dir_inlined);
3145 if (!ent->dir_bh)
3146 return retval;
3147 if (le32_to_cpu(ent->parent_de->inode) != ent->dir->i_ino)
3148 return -EIO;
3149 BUFFER_TRACE(ent->dir_bh, "get_write_access");
3150 return ext4_journal_get_write_access(handle, ent->dir_bh);
3151 }
3152
3153 static int ext4_rename_dir_finish(handle_t *handle, struct ext4_renament *ent,
3154 unsigned dir_ino)
3155 {
3156 int retval;
3157
3158 ent->parent_de->inode = cpu_to_le32(dir_ino);
3159 BUFFER_TRACE(ent->dir_bh, "call ext4_handle_dirty_metadata");
3160 if (!ent->dir_inlined) {
3161 if (is_dx(ent->inode)) {
3162 retval = ext4_handle_dirty_dx_node(handle,
3163 ent->inode,
3164 ent->dir_bh);
3165 } else {
3166 retval = ext4_handle_dirty_dirent_node(handle,
3167 ent->inode,
3168 ent->dir_bh);
3169 }
3170 } else {
3171 retval = ext4_mark_inode_dirty(handle, ent->inode);
3172 }
3173 if (retval) {
3174 ext4_std_error(ent->dir->i_sb, retval);
3175 return retval;
3176 }
3177 return 0;
3178 }
3179
3180 static int ext4_setent(handle_t *handle, struct ext4_renament *ent,
3181 unsigned ino, unsigned file_type)
3182 {
3183 int retval;
3184
3185 BUFFER_TRACE(ent->bh, "get write access");
3186 retval = ext4_journal_get_write_access(handle, ent->bh);
3187 if (retval)
3188 return retval;
3189 ent->de->inode = cpu_to_le32(ino);
3190 if (EXT4_HAS_INCOMPAT_FEATURE(ent->dir->i_sb,
3191 EXT4_FEATURE_INCOMPAT_FILETYPE))
3192 ent->de->file_type = file_type;
3193 ent->dir->i_version++;
3194 ent->dir->i_ctime = ent->dir->i_mtime =
3195 ext4_current_time(ent->dir);
3196 ext4_mark_inode_dirty(handle, ent->dir);
3197 BUFFER_TRACE(ent->bh, "call ext4_handle_dirty_metadata");
3198 if (!ent->inlined) {
3199 retval = ext4_handle_dirty_dirent_node(handle,
3200 ent->dir, ent->bh);
3201 if (unlikely(retval)) {
3202 ext4_std_error(ent->dir->i_sb, retval);
3203 return retval;
3204 }
3205 }
3206 brelse(ent->bh);
3207 ent->bh = NULL;
3208
3209 return 0;
3210 }
3211
3212 static int ext4_find_delete_entry(handle_t *handle, struct inode *dir,
3213 const struct qstr *d_name)
3214 {
3215 int retval = -ENOENT;
3216 struct buffer_head *bh;
3217 struct ext4_dir_entry_2 *de;
3218
3219 bh = ext4_find_entry(dir, d_name, &de, NULL);
3220 if (IS_ERR(bh))
3221 return PTR_ERR(bh);
3222 if (bh) {
3223 retval = ext4_delete_entry(handle, dir, de, bh);
3224 brelse(bh);
3225 }
3226 return retval;
3227 }
3228
3229 static void ext4_rename_delete(handle_t *handle, struct ext4_renament *ent,
3230 int force_reread)
3231 {
3232 int retval;
3233 /*
3234 * ent->de could have moved from under us during htree split, so make
3235 * sure that we are deleting the right entry. We might also be pointing
3236 * to a stale entry in the unused part of ent->bh so just checking inum
3237 * and the name isn't enough.
3238 */
3239 if (le32_to_cpu(ent->de->inode) != ent->inode->i_ino ||
3240 ent->de->name_len != ent->dentry->d_name.len ||
3241 strncmp(ent->de->name, ent->dentry->d_name.name,
3242 ent->de->name_len) ||
3243 force_reread) {
3244 retval = ext4_find_delete_entry(handle, ent->dir,
3245 &ent->dentry->d_name);
3246 } else {
3247 retval = ext4_delete_entry(handle, ent->dir, ent->de, ent->bh);
3248 if (retval == -ENOENT) {
3249 retval = ext4_find_delete_entry(handle, ent->dir,
3250 &ent->dentry->d_name);
3251 }
3252 }
3253
3254 if (retval) {
3255 ext4_warning(ent->dir->i_sb,
3256 "Deleting old file (%lu), %d, error=%d",
3257 ent->dir->i_ino, ent->dir->i_nlink, retval);
3258 }
3259 }
3260
3261 static void ext4_update_dir_count(handle_t *handle, struct ext4_renament *ent)
3262 {
3263 if (ent->dir_nlink_delta) {
3264 if (ent->dir_nlink_delta == -1)
3265 ext4_dec_count(handle, ent->dir);
3266 else
3267 ext4_inc_count(handle, ent->dir);
3268 ext4_mark_inode_dirty(handle, ent->dir);
3269 }
3270 }
3271
3272 static struct inode *ext4_whiteout_for_rename(struct ext4_renament *ent,
3273 int credits, handle_t **h)
3274 {
3275 struct inode *wh;
3276 handle_t *handle;
3277 int retries = 0;
3278
3279 /*
3280 * for inode block, sb block, group summaries,
3281 * and inode bitmap
3282 */
3283 credits += (EXT4_MAXQUOTAS_TRANS_BLOCKS(ent->dir->i_sb) +
3284 EXT4_XATTR_TRANS_BLOCKS + 4);
3285 retry:
3286 wh = ext4_new_inode_start_handle(ent->dir, S_IFCHR | WHITEOUT_MODE,
3287 &ent->dentry->d_name, 0, NULL,
3288 EXT4_HT_DIR, credits);
3289
3290 handle = ext4_journal_current_handle();
3291 if (IS_ERR(wh)) {
3292 if (handle)
3293 ext4_journal_stop(handle);
3294 if (PTR_ERR(wh) == -ENOSPC &&
3295 ext4_should_retry_alloc(ent->dir->i_sb, &retries))
3296 goto retry;
3297 } else {
3298 *h = handle;
3299 init_special_inode(wh, wh->i_mode, WHITEOUT_DEV);
3300 wh->i_op = &ext4_special_inode_operations;
3301 }
3302 return wh;
3303 }
3304
3305 /*
3306 * Anybody can rename anything with this: the permission checks are left to the
3307 * higher-level routines.
3308 *
3309 * n.b. old_{dentry,inode) refers to the source dentry/inode
3310 * while new_{dentry,inode) refers to the destination dentry/inode
3311 * This comes from rename(const char *oldpath, const char *newpath)
3312 */
3313 static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
3314 struct inode *new_dir, struct dentry *new_dentry,
3315 unsigned int flags)
3316 {
3317 handle_t *handle = NULL;
3318 struct ext4_renament old = {
3319 .dir = old_dir,
3320 .dentry = old_dentry,
3321 .inode = old_dentry->d_inode,
3322 };
3323 struct ext4_renament new = {
3324 .dir = new_dir,
3325 .dentry = new_dentry,
3326 .inode = new_dentry->d_inode,
3327 };
3328 int force_reread;
3329 int retval;
3330 struct inode *whiteout = NULL;
3331 int credits;
3332 u8 old_file_type;
3333
3334 dquot_initialize(old.dir);
3335 dquot_initialize(new.dir);
3336
3337 /* Initialize quotas before so that eventual writes go
3338 * in separate transaction */
3339 if (new.inode)
3340 dquot_initialize(new.inode);
3341
3342 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, NULL);
3343 if (IS_ERR(old.bh))
3344 return PTR_ERR(old.bh);
3345 /*
3346 * Check for inode number is _not_ due to possible IO errors.
3347 * We might rmdir the source, keep it as pwd of some process
3348 * and merrily kill the link to whatever was created under the
3349 * same name. Goodbye sticky bit ;-<
3350 */
3351 retval = -ENOENT;
3352 if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3353 goto end_rename;
3354
3355 if ((old.dir != new.dir) &&
3356 ext4_encrypted_inode(new.dir) &&
3357 !ext4_is_child_context_consistent_with_parent(new.dir,
3358 old.inode)) {
3359 retval = -EPERM;
3360 goto end_rename;
3361 }
3362
3363 new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
3364 &new.de, &new.inlined);
3365 if (IS_ERR(new.bh)) {
3366 retval = PTR_ERR(new.bh);
3367 new.bh = NULL;
3368 goto end_rename;
3369 }
3370 if (new.bh) {
3371 if (!new.inode) {
3372 brelse(new.bh);
3373 new.bh = NULL;
3374 }
3375 }
3376 if (new.inode && !test_opt(new.dir->i_sb, NO_AUTO_DA_ALLOC))
3377 ext4_alloc_da_blocks(old.inode);
3378
3379 credits = (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3380 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
3381 if (!(flags & RENAME_WHITEOUT)) {
3382 handle = ext4_journal_start(old.dir, EXT4_HT_DIR, credits);
3383 if (IS_ERR(handle)) {
3384 retval = PTR_ERR(handle);
3385 handle = NULL;
3386 goto end_rename;
3387 }
3388 } else {
3389 whiteout = ext4_whiteout_for_rename(&old, credits, &handle);
3390 if (IS_ERR(whiteout)) {
3391 retval = PTR_ERR(whiteout);
3392 whiteout = NULL;
3393 goto end_rename;
3394 }
3395 }
3396
3397 if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3398 ext4_handle_sync(handle);
3399
3400 if (S_ISDIR(old.inode->i_mode)) {
3401 if (new.inode) {
3402 retval = -ENOTEMPTY;
3403 if (!ext4_empty_dir(new.inode))
3404 goto end_rename;
3405 } else {
3406 retval = -EMLINK;
3407 if (new.dir != old.dir && EXT4_DIR_LINK_MAX(new.dir))
3408 goto end_rename;
3409 }
3410 retval = ext4_rename_dir_prepare(handle, &old);
3411 if (retval)
3412 goto end_rename;
3413 }
3414 /*
3415 * If we're renaming a file within an inline_data dir and adding or
3416 * setting the new dirent causes a conversion from inline_data to
3417 * extents/blockmap, we need to force the dirent delete code to
3418 * re-read the directory, or else we end up trying to delete a dirent
3419 * from what is now the extent tree root (or a block map).
3420 */
3421 force_reread = (new.dir->i_ino == old.dir->i_ino &&
3422 ext4_test_inode_flag(new.dir, EXT4_INODE_INLINE_DATA));
3423
3424 old_file_type = old.de->file_type;
3425 if (whiteout) {
3426 /*
3427 * Do this before adding a new entry, so the old entry is sure
3428 * to be still pointing to the valid old entry.
3429 */
3430 retval = ext4_setent(handle, &old, whiteout->i_ino,
3431 EXT4_FT_CHRDEV);
3432 if (retval)
3433 goto end_rename;
3434 ext4_mark_inode_dirty(handle, whiteout);
3435 }
3436 if (!new.bh) {
3437 retval = ext4_add_entry(handle, new.dentry, old.inode);
3438 if (retval)
3439 goto end_rename;
3440 } else {
3441 retval = ext4_setent(handle, &new,
3442 old.inode->i_ino, old_file_type);
3443 if (retval)
3444 goto end_rename;
3445 }
3446 if (force_reread)
3447 force_reread = !ext4_test_inode_flag(new.dir,
3448 EXT4_INODE_INLINE_DATA);
3449
3450 /*
3451 * Like most other Unix systems, set the ctime for inodes on a
3452 * rename.
3453 */
3454 old.inode->i_ctime = ext4_current_time(old.inode);
3455 ext4_mark_inode_dirty(handle, old.inode);
3456
3457 if (!whiteout) {
3458 /*
3459 * ok, that's it
3460 */
3461 ext4_rename_delete(handle, &old, force_reread);
3462 }
3463
3464 if (new.inode) {
3465 ext4_dec_count(handle, new.inode);
3466 new.inode->i_ctime = ext4_current_time(new.inode);
3467 }
3468 old.dir->i_ctime = old.dir->i_mtime = ext4_current_time(old.dir);
3469 ext4_update_dx_flag(old.dir);
3470 if (old.dir_bh) {
3471 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
3472 if (retval)
3473 goto end_rename;
3474
3475 ext4_dec_count(handle, old.dir);
3476 if (new.inode) {
3477 /* checked ext4_empty_dir above, can't have another
3478 * parent, ext4_dec_count() won't work for many-linked
3479 * dirs */
3480 clear_nlink(new.inode);
3481 } else {
3482 ext4_inc_count(handle, new.dir);
3483 ext4_update_dx_flag(new.dir);
3484 ext4_mark_inode_dirty(handle, new.dir);
3485 }
3486 }
3487 ext4_mark_inode_dirty(handle, old.dir);
3488 if (new.inode) {
3489 ext4_mark_inode_dirty(handle, new.inode);
3490 if (!new.inode->i_nlink)
3491 ext4_orphan_add(handle, new.inode);
3492 }
3493 retval = 0;
3494
3495 end_rename:
3496 brelse(old.dir_bh);
3497 brelse(old.bh);
3498 brelse(new.bh);
3499 if (whiteout) {
3500 if (retval)
3501 drop_nlink(whiteout);
3502 unlock_new_inode(whiteout);
3503 iput(whiteout);
3504 }
3505 if (handle)
3506 ext4_journal_stop(handle);
3507 return retval;
3508 }
3509
3510 static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
3511 struct inode *new_dir, struct dentry *new_dentry)
3512 {
3513 handle_t *handle = NULL;
3514 struct ext4_renament old = {
3515 .dir = old_dir,
3516 .dentry = old_dentry,
3517 .inode = old_dentry->d_inode,
3518 };
3519 struct ext4_renament new = {
3520 .dir = new_dir,
3521 .dentry = new_dentry,
3522 .inode = new_dentry->d_inode,
3523 };
3524 u8 new_file_type;
3525 int retval;
3526
3527 dquot_initialize(old.dir);
3528 dquot_initialize(new.dir);
3529
3530 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name,
3531 &old.de, &old.inlined);
3532 if (IS_ERR(old.bh))
3533 return PTR_ERR(old.bh);
3534 /*
3535 * Check for inode number is _not_ due to possible IO errors.
3536 * We might rmdir the source, keep it as pwd of some process
3537 * and merrily kill the link to whatever was created under the
3538 * same name. Goodbye sticky bit ;-<
3539 */
3540 retval = -ENOENT;
3541 if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3542 goto end_rename;
3543
3544 new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
3545 &new.de, &new.inlined);
3546 if (IS_ERR(new.bh)) {
3547 retval = PTR_ERR(new.bh);
3548 new.bh = NULL;
3549 goto end_rename;
3550 }
3551
3552 /* RENAME_EXCHANGE case: old *and* new must both exist */
3553 if (!new.bh || le32_to_cpu(new.de->inode) != new.inode->i_ino)
3554 goto end_rename;
3555
3556 handle = ext4_journal_start(old.dir, EXT4_HT_DIR,
3557 (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3558 2 * EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2));
3559 if (IS_ERR(handle)) {
3560 retval = PTR_ERR(handle);
3561 handle = NULL;
3562 goto end_rename;
3563 }
3564
3565 if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3566 ext4_handle_sync(handle);
3567
3568 if (S_ISDIR(old.inode->i_mode)) {
3569 old.is_dir = true;
3570 retval = ext4_rename_dir_prepare(handle, &old);
3571 if (retval)
3572 goto end_rename;
3573 }
3574 if (S_ISDIR(new.inode->i_mode)) {
3575 new.is_dir = true;
3576 retval = ext4_rename_dir_prepare(handle, &new);
3577 if (retval)
3578 goto end_rename;
3579 }
3580
3581 /*
3582 * Other than the special case of overwriting a directory, parents'
3583 * nlink only needs to be modified if this is a cross directory rename.
3584 */
3585 if (old.dir != new.dir && old.is_dir != new.is_dir) {
3586 old.dir_nlink_delta = old.is_dir ? -1 : 1;
3587 new.dir_nlink_delta = -old.dir_nlink_delta;
3588 retval = -EMLINK;
3589 if ((old.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(old.dir)) ||
3590 (new.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(new.dir)))
3591 goto end_rename;
3592 }
3593
3594 new_file_type = new.de->file_type;
3595 retval = ext4_setent(handle, &new, old.inode->i_ino, old.de->file_type);
3596 if (retval)
3597 goto end_rename;
3598
3599 retval = ext4_setent(handle, &old, new.inode->i_ino, new_file_type);
3600 if (retval)
3601 goto end_rename;
3602
3603 /*
3604 * Like most other Unix systems, set the ctime for inodes on a
3605 * rename.
3606 */
3607 old.inode->i_ctime = ext4_current_time(old.inode);
3608 new.inode->i_ctime = ext4_current_time(new.inode);
3609 ext4_mark_inode_dirty(handle, old.inode);
3610 ext4_mark_inode_dirty(handle, new.inode);
3611
3612 if (old.dir_bh) {
3613 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
3614 if (retval)
3615 goto end_rename;
3616 }
3617 if (new.dir_bh) {
3618 retval = ext4_rename_dir_finish(handle, &new, old.dir->i_ino);
3619 if (retval)
3620 goto end_rename;
3621 }
3622 ext4_update_dir_count(handle, &old);
3623 ext4_update_dir_count(handle, &new);
3624 retval = 0;
3625
3626 end_rename:
3627 brelse(old.dir_bh);
3628 brelse(new.dir_bh);
3629 brelse(old.bh);
3630 brelse(new.bh);
3631 if (handle)
3632 ext4_journal_stop(handle);
3633 return retval;
3634 }
3635
3636 static int ext4_rename2(struct inode *old_dir, struct dentry *old_dentry,
3637 struct inode *new_dir, struct dentry *new_dentry,
3638 unsigned int flags)
3639 {
3640 if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
3641 return -EINVAL;
3642
3643 if (flags & RENAME_EXCHANGE) {
3644 return ext4_cross_rename(old_dir, old_dentry,
3645 new_dir, new_dentry);
3646 }
3647
3648 return ext4_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
3649 }
3650
3651 /*
3652 * directories can handle most operations...
3653 */
3654 const struct inode_operations ext4_dir_inode_operations = {
3655 .create = ext4_create,
3656 .lookup = ext4_lookup,
3657 .link = ext4_link,
3658 .unlink = ext4_unlink,
3659 .symlink = ext4_symlink,
3660 .mkdir = ext4_mkdir,
3661 .rmdir = ext4_rmdir,
3662 .mknod = ext4_mknod,
3663 .tmpfile = ext4_tmpfile,
3664 .rename2 = ext4_rename2,
3665 .setattr = ext4_setattr,
3666 .setxattr = generic_setxattr,
3667 .getxattr = generic_getxattr,
3668 .listxattr = ext4_listxattr,
3669 .removexattr = generic_removexattr,
3670 .get_acl = ext4_get_acl,
3671 .set_acl = ext4_set_acl,
3672 .fiemap = ext4_fiemap,
3673 };
3674
3675 const struct inode_operations ext4_special_inode_operations = {
3676 .setattr = ext4_setattr,
3677 .setxattr = generic_setxattr,
3678 .getxattr = generic_getxattr,
3679 .listxattr = ext4_listxattr,
3680 .removexattr = generic_removexattr,
3681 .get_acl = ext4_get_acl,
3682 .set_acl = ext4_set_acl,
3683 };
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