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Linux 3.6.10
[linux/fpc-iii.git] / fs / ext4 / namei.c
blobd13873d7cfc1c588abbf6b37fdf8f4cdcc7da873
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/jbd2.h>
30 #include <linux/time.h>
31 #include <linux/fcntl.h>
32 #include <linux/stat.h>
33 #include <linux/string.h>
34 #include <linux/quotaops.h>
35 #include <linux/buffer_head.h>
36 #include <linux/bio.h>
37 #include "ext4.h"
38 #include "ext4_jbd2.h"
39
40 #include "xattr.h"
41 #include "acl.h"
42
43 #include <trace/events/ext4.h>
44 /*
45 * define how far ahead to read directories while searching them.
46 */
47 #define NAMEI_RA_CHUNKS 2
48 #define NAMEI_RA_BLOCKS 4
49 #define NAMEI_RA_SIZE (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS)
50 #define NAMEI_RA_INDEX(c,b) (((c) * NAMEI_RA_BLOCKS) + (b))
51
52 static struct buffer_head *ext4_append(handle_t *handle,
53 struct inode *inode,
54 ext4_lblk_t *block, int *err)
55 {
56 struct buffer_head *bh;
57
58 *block = inode->i_size >> inode->i_sb->s_blocksize_bits;
59
60 bh = ext4_bread(handle, inode, *block, 1, err);
61 if (bh) {
62 inode->i_size += inode->i_sb->s_blocksize;
63 EXT4_I(inode)->i_disksize = inode->i_size;
64 *err = ext4_journal_get_write_access(handle, bh);
65 if (*err) {
66 brelse(bh);
67 bh = NULL;
68 }
69 }
70 return bh;
71 }
72
73 #ifndef assert
74 #define assert(test) J_ASSERT(test)
75 #endif
76
77 #ifdef DX_DEBUG
78 #define dxtrace(command) command
79 #else
80 #define dxtrace(command)
81 #endif
82
83 struct fake_dirent
84 {
85 __le32 inode;
86 __le16 rec_len;
87 u8 name_len;
88 u8 file_type;
89 };
90
91 struct dx_countlimit
92 {
93 __le16 limit;
94 __le16 count;
95 };
96
97 struct dx_entry
98 {
99 __le32 hash;
100 __le32 block;
101 };
102
103 /*
104 * dx_root_info is laid out so that if it should somehow get overlaid by a
105 * dirent the two low bits of the hash version will be zero. Therefore, the
106 * hash version mod 4 should never be 0. Sincerely, the paranoia department.
107 */
108
109 struct dx_root
110 {
111 struct fake_dirent dot;
112 char dot_name[4];
113 struct fake_dirent dotdot;
114 char dotdot_name[4];
115 struct dx_root_info
116 {
117 __le32 reserved_zero;
118 u8 hash_version;
119 u8 info_length; /* 8 */
120 u8 indirect_levels;
121 u8 unused_flags;
122 }
123 info;
124 struct dx_entry entries[0];
125 };
126
127 struct dx_node
128 {
129 struct fake_dirent fake;
130 struct dx_entry entries[0];
131 };
132
133
134 struct dx_frame
135 {
136 struct buffer_head *bh;
137 struct dx_entry *entries;
138 struct dx_entry *at;
139 };
140
141 struct dx_map_entry
142 {
143 u32 hash;
144 u16 offs;
145 u16 size;
146 };
147
148 /*
149 * This goes at the end of each htree block.
150 */
151 struct dx_tail {
152 u32 dt_reserved;
153 __le32 dt_checksum; /* crc32c(uuid+inum+dirblock) */
154 };
155
156 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
157 static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
158 static inline unsigned dx_get_hash(struct dx_entry *entry);
159 static void dx_set_hash(struct dx_entry *entry, unsigned value);
160 static unsigned dx_get_count(struct dx_entry *entries);
161 static unsigned dx_get_limit(struct dx_entry *entries);
162 static void dx_set_count(struct dx_entry *entries, unsigned value);
163 static void dx_set_limit(struct dx_entry *entries, unsigned value);
164 static unsigned dx_root_limit(struct inode *dir, unsigned infosize);
165 static unsigned dx_node_limit(struct inode *dir);
166 static struct dx_frame *dx_probe(const struct qstr *d_name,
167 struct inode *dir,
168 struct dx_hash_info *hinfo,
169 struct dx_frame *frame,
170 int *err);
171 static void dx_release(struct dx_frame *frames);
172 static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize,
173 struct dx_hash_info *hinfo, struct dx_map_entry map[]);
174 static void dx_sort_map(struct dx_map_entry *map, unsigned count);
175 static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to,
176 struct dx_map_entry *offsets, int count, unsigned blocksize);
177 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize);
178 static void dx_insert_block(struct dx_frame *frame,
179 u32 hash, ext4_lblk_t block);
180 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
181 struct dx_frame *frame,
182 struct dx_frame *frames,
183 __u32 *start_hash);
184 static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
185 const struct qstr *d_name,
186 struct ext4_dir_entry_2 **res_dir,
187 int *err);
188 static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
189 struct inode *inode);
190
191 /* checksumming functions */
192 #define EXT4_DIRENT_TAIL(block, blocksize) \
193 ((struct ext4_dir_entry_tail *)(((void *)(block)) + \
194 ((blocksize) - \
195 sizeof(struct ext4_dir_entry_tail))))
196
197 static void initialize_dirent_tail(struct ext4_dir_entry_tail *t,
198 unsigned int blocksize)
199 {
200 memset(t, 0, sizeof(struct ext4_dir_entry_tail));
201 t->det_rec_len = ext4_rec_len_to_disk(
202 sizeof(struct ext4_dir_entry_tail), blocksize);
203 t->det_reserved_ft = EXT4_FT_DIR_CSUM;
204 }
205
206 /* Walk through a dirent block to find a checksum "dirent" at the tail */
207 static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode,
208 struct ext4_dir_entry *de)
209 {
210 struct ext4_dir_entry_tail *t;
211
212 #ifdef PARANOID
213 struct ext4_dir_entry *d, *top;
214
215 d = de;
216 top = (struct ext4_dir_entry *)(((void *)de) +
217 (EXT4_BLOCK_SIZE(inode->i_sb) -
218 sizeof(struct ext4_dir_entry_tail)));
219 while (d < top && d->rec_len)
220 d = (struct ext4_dir_entry *)(((void *)d) +
221 le16_to_cpu(d->rec_len));
222
223 if (d != top)
224 return NULL;
225
226 t = (struct ext4_dir_entry_tail *)d;
227 #else
228 t = EXT4_DIRENT_TAIL(de, EXT4_BLOCK_SIZE(inode->i_sb));
229 #endif
230
231 if (t->det_reserved_zero1 ||
232 le16_to_cpu(t->det_rec_len) != sizeof(struct ext4_dir_entry_tail) ||
233 t->det_reserved_zero2 ||
234 t->det_reserved_ft != EXT4_FT_DIR_CSUM)
235 return NULL;
236
237 return t;
238 }
239
240 static __le32 ext4_dirent_csum(struct inode *inode,
241 struct ext4_dir_entry *dirent, int size)
242 {
243 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
244 struct ext4_inode_info *ei = EXT4_I(inode);
245 __u32 csum;
246
247 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
248 return cpu_to_le32(csum);
249 }
250
251 int ext4_dirent_csum_verify(struct inode *inode, struct ext4_dir_entry *dirent)
252 {
253 struct ext4_dir_entry_tail *t;
254
255 if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
256 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
257 return 1;
258
259 t = get_dirent_tail(inode, dirent);
260 if (!t) {
261 EXT4_ERROR_INODE(inode, "metadata_csum set but no space in dir "
262 "leaf for checksum. Please run e2fsck -D.");
263 return 0;
264 }
265
266 if (t->det_checksum != ext4_dirent_csum(inode, dirent,
267 (void *)t - (void *)dirent))
268 return 0;
269
270 return 1;
271 }
272
273 static void ext4_dirent_csum_set(struct inode *inode,
274 struct ext4_dir_entry *dirent)
275 {
276 struct ext4_dir_entry_tail *t;
277
278 if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
279 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
280 return;
281
282 t = get_dirent_tail(inode, dirent);
283 if (!t) {
284 EXT4_ERROR_INODE(inode, "metadata_csum set but no space in dir "
285 "leaf for checksum. Please run e2fsck -D.");
286 return;
287 }
288
289 t->det_checksum = ext4_dirent_csum(inode, dirent,
290 (void *)t - (void *)dirent);
291 }
292
293 static inline int ext4_handle_dirty_dirent_node(handle_t *handle,
294 struct inode *inode,
295 struct buffer_head *bh)
296 {
297 ext4_dirent_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
298 return ext4_handle_dirty_metadata(handle, inode, bh);
299 }
300
301 static struct dx_countlimit *get_dx_countlimit(struct inode *inode,
302 struct ext4_dir_entry *dirent,
303 int *offset)
304 {
305 struct ext4_dir_entry *dp;
306 struct dx_root_info *root;
307 int count_offset;
308
309 if (le16_to_cpu(dirent->rec_len) == EXT4_BLOCK_SIZE(inode->i_sb))
310 count_offset = 8;
311 else if (le16_to_cpu(dirent->rec_len) == 12) {
312 dp = (struct ext4_dir_entry *)(((void *)dirent) + 12);
313 if (le16_to_cpu(dp->rec_len) !=
314 EXT4_BLOCK_SIZE(inode->i_sb) - 12)
315 return NULL;
316 root = (struct dx_root_info *)(((void *)dp + 12));
317 if (root->reserved_zero ||
318 root->info_length != sizeof(struct dx_root_info))
319 return NULL;
320 count_offset = 32;
321 } else
322 return NULL;
323
324 if (offset)
325 *offset = count_offset;
326 return (struct dx_countlimit *)(((void *)dirent) + count_offset);
327 }
328
329 static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent,
330 int count_offset, int count, struct dx_tail *t)
331 {
332 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
333 struct ext4_inode_info *ei = EXT4_I(inode);
334 __u32 csum, old_csum;
335 int size;
336
337 size = count_offset + (count * sizeof(struct dx_entry));
338 old_csum = t->dt_checksum;
339 t->dt_checksum = 0;
340 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
341 csum = ext4_chksum(sbi, csum, (__u8 *)t, sizeof(struct dx_tail));
342 t->dt_checksum = old_csum;
343
344 return cpu_to_le32(csum);
345 }
346
347 static int ext4_dx_csum_verify(struct inode *inode,
348 struct ext4_dir_entry *dirent)
349 {
350 struct dx_countlimit *c;
351 struct dx_tail *t;
352 int count_offset, limit, count;
353
354 if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
355 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
356 return 1;
357
358 c = get_dx_countlimit(inode, dirent, &count_offset);
359 if (!c) {
360 EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D.");
361 return 1;
362 }
363 limit = le16_to_cpu(c->limit);
364 count = le16_to_cpu(c->count);
365 if (count_offset + (limit * sizeof(struct dx_entry)) >
366 EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
367 EXT4_ERROR_INODE(inode, "metadata_csum set but no space for "
368 "tree checksum found. Run e2fsck -D.");
369 return 1;
370 }
371 t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
372
373 if (t->dt_checksum != ext4_dx_csum(inode, dirent, count_offset,
374 count, t))
375 return 0;
376 return 1;
377 }
378
379 static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent)
380 {
381 struct dx_countlimit *c;
382 struct dx_tail *t;
383 int count_offset, limit, count;
384
385 if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
386 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
387 return;
388
389 c = get_dx_countlimit(inode, dirent, &count_offset);
390 if (!c) {
391 EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D.");
392 return;
393 }
394 limit = le16_to_cpu(c->limit);
395 count = le16_to_cpu(c->count);
396 if (count_offset + (limit * sizeof(struct dx_entry)) >
397 EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
398 EXT4_ERROR_INODE(inode, "metadata_csum set but no space for "
399 "tree checksum. Run e2fsck -D.");
400 return;
401 }
402 t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
403
404 t->dt_checksum = ext4_dx_csum(inode, dirent, count_offset, count, t);
405 }
406
407 static inline int ext4_handle_dirty_dx_node(handle_t *handle,
408 struct inode *inode,
409 struct buffer_head *bh)
410 {
411 ext4_dx_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
412 return ext4_handle_dirty_metadata(handle, inode, bh);
413 }
414
415 /*
416 * p is at least 6 bytes before the end of page
417 */
418 static inline struct ext4_dir_entry_2 *
419 ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
420 {
421 return (struct ext4_dir_entry_2 *)((char *)p +
422 ext4_rec_len_from_disk(p->rec_len, blocksize));
423 }
424
425 /*
426 * Future: use high four bits of block for coalesce-on-delete flags
427 * Mask them off for now.
428 */
429
430 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
431 {
432 return le32_to_cpu(entry->block) & 0x00ffffff;
433 }
434
435 static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
436 {
437 entry->block = cpu_to_le32(value);
438 }
439
440 static inline unsigned dx_get_hash(struct dx_entry *entry)
441 {
442 return le32_to_cpu(entry->hash);
443 }
444
445 static inline void dx_set_hash(struct dx_entry *entry, unsigned value)
446 {
447 entry->hash = cpu_to_le32(value);
448 }
449
450 static inline unsigned dx_get_count(struct dx_entry *entries)
451 {
452 return le16_to_cpu(((struct dx_countlimit *) entries)->count);
453 }
454
455 static inline unsigned dx_get_limit(struct dx_entry *entries)
456 {
457 return le16_to_cpu(((struct dx_countlimit *) entries)->limit);
458 }
459
460 static inline void dx_set_count(struct dx_entry *entries, unsigned value)
461 {
462 ((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
463 }
464
465 static inline void dx_set_limit(struct dx_entry *entries, unsigned value)
466 {
467 ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
468 }
469
470 static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
471 {
472 unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
473 EXT4_DIR_REC_LEN(2) - infosize;
474
475 if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
476 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
477 entry_space -= sizeof(struct dx_tail);
478 return entry_space / sizeof(struct dx_entry);
479 }
480
481 static inline unsigned dx_node_limit(struct inode *dir)
482 {
483 unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);
484
485 if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
486 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
487 entry_space -= sizeof(struct dx_tail);
488 return entry_space / sizeof(struct dx_entry);
489 }
490
491 /*
492 * Debug
493 */
494 #ifdef DX_DEBUG
495 static void dx_show_index(char * label, struct dx_entry *entries)
496 {
497 int i, n = dx_get_count (entries);
498 printk(KERN_DEBUG "%s index ", label);
499 for (i = 0; i < n; i++) {
500 printk("%x->%lu ", i ? dx_get_hash(entries + i) :
501 0, (unsigned long)dx_get_block(entries + i));
502 }
503 printk("\n");
504 }
505
506 struct stats
507 {
508 unsigned names;
509 unsigned space;
510 unsigned bcount;
511 };
512
513 static struct stats dx_show_leaf(struct dx_hash_info *hinfo, struct ext4_dir_entry_2 *de,
514 int size, int show_names)
515 {
516 unsigned names = 0, space = 0;
517 char *base = (char *) de;
518 struct dx_hash_info h = *hinfo;
519
520 printk("names: ");
521 while ((char *) de < base + size)
522 {
523 if (de->inode)
524 {
525 if (show_names)
526 {
527 int len = de->name_len;
528 char *name = de->name;
529 while (len--) printk("%c", *name++);
530 ext4fs_dirhash(de->name, de->name_len, &h);
531 printk(":%x.%u ", h.hash,
532 (unsigned) ((char *) de - base));
533 }
534 space += EXT4_DIR_REC_LEN(de->name_len);
535 names++;
536 }
537 de = ext4_next_entry(de, size);
538 }
539 printk("(%i)\n", names);
540 return (struct stats) { names, space, 1 };
541 }
542
543 struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
544 struct dx_entry *entries, int levels)
545 {
546 unsigned blocksize = dir->i_sb->s_blocksize;
547 unsigned count = dx_get_count(entries), names = 0, space = 0, i;
548 unsigned bcount = 0;
549 struct buffer_head *bh;
550 int err;
551 printk("%i indexed blocks...\n", count);
552 for (i = 0; i < count; i++, entries++)
553 {
554 ext4_lblk_t block = dx_get_block(entries);
555 ext4_lblk_t hash = i ? dx_get_hash(entries): 0;
556 u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
557 struct stats stats;
558 printk("%s%3u:%03u hash %8x/%8x ",levels?"":" ", i, block, hash, range);
559 if (!(bh = ext4_bread (NULL,dir, block, 0,&err))) continue;
560 stats = levels?
561 dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
562 dx_show_leaf(hinfo, (struct ext4_dir_entry_2 *) bh->b_data, blocksize, 0);
563 names += stats.names;
564 space += stats.space;
565 bcount += stats.bcount;
566 brelse(bh);
567 }
568 if (bcount)
569 printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n",
570 levels ? "" : " ", names, space/bcount,
571 (space/bcount)*100/blocksize);
572 return (struct stats) { names, space, bcount};
573 }
574 #endif /* DX_DEBUG */
575
576 /*
577 * Probe for a directory leaf block to search.
578 *
579 * dx_probe can return ERR_BAD_DX_DIR, which means there was a format
580 * error in the directory index, and the caller should fall back to
581 * searching the directory normally. The callers of dx_probe **MUST**
582 * check for this error code, and make sure it never gets reflected
583 * back to userspace.
584 */
585 static struct dx_frame *
586 dx_probe(const struct qstr *d_name, struct inode *dir,
587 struct dx_hash_info *hinfo, struct dx_frame *frame_in, int *err)
588 {
589 unsigned count, indirect;
590 struct dx_entry *at, *entries, *p, *q, *m;
591 struct dx_root *root;
592 struct buffer_head *bh;
593 struct dx_frame *frame = frame_in;
594 u32 hash;
595
596 frame->bh = NULL;
597 if (!(bh = ext4_bread (NULL,dir, 0, 0, err)))
598 goto fail;
599 root = (struct dx_root *) bh->b_data;
600 if (root->info.hash_version != DX_HASH_TEA &&
601 root->info.hash_version != DX_HASH_HALF_MD4 &&
602 root->info.hash_version != DX_HASH_LEGACY) {
603 ext4_warning(dir->i_sb, "Unrecognised inode hash code %d",
604 root->info.hash_version);
605 brelse(bh);
606 *err = ERR_BAD_DX_DIR;
607 goto fail;
608 }
609 hinfo->hash_version = root->info.hash_version;
610 if (hinfo->hash_version <= DX_HASH_TEA)
611 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
612 hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
613 if (d_name)
614 ext4fs_dirhash(d_name->name, d_name->len, hinfo);
615 hash = hinfo->hash;
616
617 if (root->info.unused_flags & 1) {
618 ext4_warning(dir->i_sb, "Unimplemented inode hash flags: %#06x",
619 root->info.unused_flags);
620 brelse(bh);
621 *err = ERR_BAD_DX_DIR;
622 goto fail;
623 }
624
625 if ((indirect = root->info.indirect_levels) > 1) {
626 ext4_warning(dir->i_sb, "Unimplemented inode hash depth: %#06x",
627 root->info.indirect_levels);
628 brelse(bh);
629 *err = ERR_BAD_DX_DIR;
630 goto fail;
631 }
632
633 if (!buffer_verified(bh) &&
634 !ext4_dx_csum_verify(dir, (struct ext4_dir_entry *)bh->b_data)) {
635 ext4_warning(dir->i_sb, "Root failed checksum");
636 brelse(bh);
637 *err = ERR_BAD_DX_DIR;
638 goto fail;
639 }
640 set_buffer_verified(bh);
641
642 entries = (struct dx_entry *) (((char *)&root->info) +
643 root->info.info_length);
644
645 if (dx_get_limit(entries) != dx_root_limit(dir,
646 root->info.info_length)) {
647 ext4_warning(dir->i_sb, "dx entry: limit != root limit");
648 brelse(bh);
649 *err = ERR_BAD_DX_DIR;
650 goto fail;
651 }
652
653 dxtrace(printk("Look up %x", hash));
654 while (1)
655 {
656 count = dx_get_count(entries);
657 if (!count || count > dx_get_limit(entries)) {
658 ext4_warning(dir->i_sb,
659 "dx entry: no count or count > limit");
660 brelse(bh);
661 *err = ERR_BAD_DX_DIR;
662 goto fail2;
663 }
664
665 p = entries + 1;
666 q = entries + count - 1;
667 while (p <= q)
668 {
669 m = p + (q - p)/2;
670 dxtrace(printk("."));
671 if (dx_get_hash(m) > hash)
672 q = m - 1;
673 else
674 p = m + 1;
675 }
676
677 if (0) // linear search cross check
678 {
679 unsigned n = count - 1;
680 at = entries;
681 while (n--)
682 {
683 dxtrace(printk(","));
684 if (dx_get_hash(++at) > hash)
685 {
686 at--;
687 break;
688 }
689 }
690 assert (at == p - 1);
691 }
692
693 at = p - 1;
694 dxtrace(printk(" %x->%u\n", at == entries? 0: dx_get_hash(at), dx_get_block(at)));
695 frame->bh = bh;
696 frame->entries = entries;
697 frame->at = at;
698 if (!indirect--) return frame;
699 if (!(bh = ext4_bread (NULL,dir, dx_get_block(at), 0, err)))
700 goto fail2;
701 at = entries = ((struct dx_node *) bh->b_data)->entries;
702
703 if (!buffer_verified(bh) &&
704 !ext4_dx_csum_verify(dir,
705 (struct ext4_dir_entry *)bh->b_data)) {
706 ext4_warning(dir->i_sb, "Node failed checksum");
707 brelse(bh);
708 *err = ERR_BAD_DX_DIR;
709 goto fail;
710 }
711 set_buffer_verified(bh);
712
713 if (dx_get_limit(entries) != dx_node_limit (dir)) {
714 ext4_warning(dir->i_sb,
715 "dx entry: limit != node limit");
716 brelse(bh);
717 *err = ERR_BAD_DX_DIR;
718 goto fail2;
719 }
720 frame++;
721 frame->bh = NULL;
722 }
723 fail2:
724 while (frame >= frame_in) {
725 brelse(frame->bh);
726 frame--;
727 }
728 fail:
729 if (*err == ERR_BAD_DX_DIR)
730 ext4_warning(dir->i_sb,
731 "Corrupt dir inode %lu, running e2fsck is "
732 "recommended.", dir->i_ino);
733 return NULL;
734 }
735
736 static void dx_release (struct dx_frame *frames)
737 {
738 if (frames[0].bh == NULL)
739 return;
740
741 if (((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels)
742 brelse(frames[1].bh);
743 brelse(frames[0].bh);
744 }
745
746 /*
747 * This function increments the frame pointer to search the next leaf
748 * block, and reads in the necessary intervening nodes if the search
749 * should be necessary. Whether or not the search is necessary is
750 * controlled by the hash parameter. If the hash value is even, then
751 * the search is only continued if the next block starts with that
752 * hash value. This is used if we are searching for a specific file.
753 *
754 * If the hash value is HASH_NB_ALWAYS, then always go to the next block.
755 *
756 * This function returns 1 if the caller should continue to search,
757 * or 0 if it should not. If there is an error reading one of the
758 * index blocks, it will a negative error code.
759 *
760 * If start_hash is non-null, it will be filled in with the starting
761 * hash of the next page.
762 */
763 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
764 struct dx_frame *frame,
765 struct dx_frame *frames,
766 __u32 *start_hash)
767 {
768 struct dx_frame *p;
769 struct buffer_head *bh;
770 int err, num_frames = 0;
771 __u32 bhash;
772
773 p = frame;
774 /*
775 * Find the next leaf page by incrementing the frame pointer.
776 * If we run out of entries in the interior node, loop around and
777 * increment pointer in the parent node. When we break out of
778 * this loop, num_frames indicates the number of interior
779 * nodes need to be read.
780 */
781 while (1) {
782 if (++(p->at) < p->entries + dx_get_count(p->entries))
783 break;
784 if (p == frames)
785 return 0;
786 num_frames++;
787 p--;
788 }
789
790 /*
791 * If the hash is 1, then continue only if the next page has a
792 * continuation hash of any value. This is used for readdir
793 * handling. Otherwise, check to see if the hash matches the
794 * desired contiuation hash. If it doesn't, return since
795 * there's no point to read in the successive index pages.
796 */
797 bhash = dx_get_hash(p->at);
798 if (start_hash)
799 *start_hash = bhash;
800 if ((hash & 1) == 0) {
801 if ((bhash & ~1) != hash)
802 return 0;
803 }
804 /*
805 * If the hash is HASH_NB_ALWAYS, we always go to the next
806 * block so no check is necessary
807 */
808 while (num_frames--) {
809 if (!(bh = ext4_bread(NULL, dir, dx_get_block(p->at),
810 0, &err)))
811 return err; /* Failure */
812
813 if (!buffer_verified(bh) &&
814 !ext4_dx_csum_verify(dir,
815 (struct ext4_dir_entry *)bh->b_data)) {
816 ext4_warning(dir->i_sb, "Node failed checksum");
817 return -EIO;
818 }
819 set_buffer_verified(bh);
820
821 p++;
822 brelse(p->bh);
823 p->bh = bh;
824 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
825 }
826 return 1;
827 }
828
829
830 /*
831 * This function fills a red-black tree with information from a
832 * directory block. It returns the number directory entries loaded
833 * into the tree. If there is an error it is returned in err.
834 */
835 static int htree_dirblock_to_tree(struct file *dir_file,
836 struct inode *dir, ext4_lblk_t block,
837 struct dx_hash_info *hinfo,
838 __u32 start_hash, __u32 start_minor_hash)
839 {
840 struct buffer_head *bh;
841 struct ext4_dir_entry_2 *de, *top;
842 int err, count = 0;
843
844 dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
845 (unsigned long)block));
846 if (!(bh = ext4_bread (NULL, dir, block, 0, &err)))
847 return err;
848
849 if (!buffer_verified(bh) &&
850 !ext4_dirent_csum_verify(dir, (struct ext4_dir_entry *)bh->b_data))
851 return -EIO;
852 set_buffer_verified(bh);
853
854 de = (struct ext4_dir_entry_2 *) bh->b_data;
855 top = (struct ext4_dir_entry_2 *) ((char *) de +
856 dir->i_sb->s_blocksize -
857 EXT4_DIR_REC_LEN(0));
858 for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) {
859 if (ext4_check_dir_entry(dir, NULL, de, bh,
860 (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
861 + ((char *)de - bh->b_data))) {
862 /* On error, skip the f_pos to the next block. */
863 dir_file->f_pos = (dir_file->f_pos |
864 (dir->i_sb->s_blocksize - 1)) + 1;
865 brelse(bh);
866 return count;
867 }
868 ext4fs_dirhash(de->name, de->name_len, hinfo);
869 if ((hinfo->hash < start_hash) ||
870 ((hinfo->hash == start_hash) &&
871 (hinfo->minor_hash < start_minor_hash)))
872 continue;
873 if (de->inode == 0)
874 continue;
875 if ((err = ext4_htree_store_dirent(dir_file,
876 hinfo->hash, hinfo->minor_hash, de)) != 0) {
877 brelse(bh);
878 return err;
879 }
880 count++;
881 }
882 brelse(bh);
883 return count;
884 }
885
886
887 /*
888 * This function fills a red-black tree with information from a
889 * directory. We start scanning the directory in hash order, starting
890 * at start_hash and start_minor_hash.
891 *
892 * This function returns the number of entries inserted into the tree,
893 * or a negative error code.
894 */
895 int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
896 __u32 start_minor_hash, __u32 *next_hash)
897 {
898 struct dx_hash_info hinfo;
899 struct ext4_dir_entry_2 *de;
900 struct dx_frame frames[2], *frame;
901 struct inode *dir;
902 ext4_lblk_t block;
903 int count = 0;
904 int ret, err;
905 __u32 hashval;
906
907 dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
908 start_hash, start_minor_hash));
909 dir = dir_file->f_path.dentry->d_inode;
910 if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) {
911 hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
912 if (hinfo.hash_version <= DX_HASH_TEA)
913 hinfo.hash_version +=
914 EXT4_SB(dir->i_sb)->s_hash_unsigned;
915 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
916 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
917 start_hash, start_minor_hash);
918 *next_hash = ~0;
919 return count;
920 }
921 hinfo.hash = start_hash;
922 hinfo.minor_hash = 0;
923 frame = dx_probe(NULL, dir, &hinfo, frames, &err);
924 if (!frame)
925 return err;
926
927 /* Add '.' and '..' from the htree header */
928 if (!start_hash && !start_minor_hash) {
929 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
930 if ((err = ext4_htree_store_dirent(dir_file, 0, 0, de)) != 0)
931 goto errout;
932 count++;
933 }
934 if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
935 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
936 de = ext4_next_entry(de, dir->i_sb->s_blocksize);
937 if ((err = ext4_htree_store_dirent(dir_file, 2, 0, de)) != 0)
938 goto errout;
939 count++;
940 }
941
942 while (1) {
943 block = dx_get_block(frame->at);
944 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
945 start_hash, start_minor_hash);
946 if (ret < 0) {
947 err = ret;
948 goto errout;
949 }
950 count += ret;
951 hashval = ~0;
952 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
953 frame, frames, &hashval);
954 *next_hash = hashval;
955 if (ret < 0) {
956 err = ret;
957 goto errout;
958 }
959 /*
960 * Stop if: (a) there are no more entries, or
961 * (b) we have inserted at least one entry and the
962 * next hash value is not a continuation
963 */
964 if ((ret == 0) ||
965 (count && ((hashval & 1) == 0)))
966 break;
967 }
968 dx_release(frames);
969 dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, "
970 "next hash: %x\n", count, *next_hash));
971 return count;
972 errout:
973 dx_release(frames);
974 return (err);
975 }
976
977
978 /*
979 * Directory block splitting, compacting
980 */
981
982 /*
983 * Create map of hash values, offsets, and sizes, stored at end of block.
984 * Returns number of entries mapped.
985 */
986 static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize,
987 struct dx_hash_info *hinfo,
988 struct dx_map_entry *map_tail)
989 {
990 int count = 0;
991 char *base = (char *) de;
992 struct dx_hash_info h = *hinfo;
993
994 while ((char *) de < base + blocksize) {
995 if (de->name_len && de->inode) {
996 ext4fs_dirhash(de->name, de->name_len, &h);
997 map_tail--;
998 map_tail->hash = h.hash;
999 map_tail->offs = ((char *) de - base)>>2;
1000 map_tail->size = le16_to_cpu(de->rec_len);
1001 count++;
1002 cond_resched();
1003 }
1004 /* XXX: do we need to check rec_len == 0 case? -Chris */
1005 de = ext4_next_entry(de, blocksize);
1006 }
1007 return count;
1008 }
1009
1010 /* Sort map by hash value */
1011 static void dx_sort_map (struct dx_map_entry *map, unsigned count)
1012 {
1013 struct dx_map_entry *p, *q, *top = map + count - 1;
1014 int more;
1015 /* Combsort until bubble sort doesn't suck */
1016 while (count > 2) {
1017 count = count*10/13;
1018 if (count - 9 < 2) /* 9, 10 -> 11 */
1019 count = 11;
1020 for (p = top, q = p - count; q >= map; p--, q--)
1021 if (p->hash < q->hash)
1022 swap(*p, *q);
1023 }
1024 /* Garden variety bubble sort */
1025 do {
1026 more = 0;
1027 q = top;
1028 while (q-- > map) {
1029 if (q[1].hash >= q[0].hash)
1030 continue;
1031 swap(*(q+1), *q);
1032 more = 1;
1033 }
1034 } while(more);
1035 }
1036
1037 static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
1038 {
1039 struct dx_entry *entries = frame->entries;
1040 struct dx_entry *old = frame->at, *new = old + 1;
1041 int count = dx_get_count(entries);
1042
1043 assert(count < dx_get_limit(entries));
1044 assert(old < entries + count);
1045 memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
1046 dx_set_hash(new, hash);
1047 dx_set_block(new, block);
1048 dx_set_count(entries, count + 1);
1049 }
1050
1051 static void ext4_update_dx_flag(struct inode *inode)
1052 {
1053 if (!EXT4_HAS_COMPAT_FEATURE(inode->i_sb,
1054 EXT4_FEATURE_COMPAT_DIR_INDEX))
1055 ext4_clear_inode_flag(inode, EXT4_INODE_INDEX);
1056 }
1057
1058 /*
1059 * NOTE! unlike strncmp, ext4_match returns 1 for success, 0 for failure.
1060 *
1061 * `len <= EXT4_NAME_LEN' is guaranteed by caller.
1062 * `de != NULL' is guaranteed by caller.
1063 */
1064 static inline int ext4_match (int len, const char * const name,
1065 struct ext4_dir_entry_2 * de)
1066 {
1067 if (len != de->name_len)
1068 return 0;
1069 if (!de->inode)
1070 return 0;
1071 return !memcmp(name, de->name, len);
1072 }
1073
1074 /*
1075 * Returns 0 if not found, -1 on failure, and 1 on success
1076 */
1077 static inline int search_dirblock(struct buffer_head *bh,
1078 struct inode *dir,
1079 const struct qstr *d_name,
1080 unsigned int offset,
1081 struct ext4_dir_entry_2 ** res_dir)
1082 {
1083 struct ext4_dir_entry_2 * de;
1084 char * dlimit;
1085 int de_len;
1086 const char *name = d_name->name;
1087 int namelen = d_name->len;
1088
1089 de = (struct ext4_dir_entry_2 *) bh->b_data;
1090 dlimit = bh->b_data + dir->i_sb->s_blocksize;
1091 while ((char *) de < dlimit) {
1092 /* this code is executed quadratically often */
1093 /* do minimal checking `by hand' */
1094
1095 if ((char *) de + namelen <= dlimit &&
1096 ext4_match (namelen, name, de)) {
1097 /* found a match - just to be sure, do a full check */
1098 if (ext4_check_dir_entry(dir, NULL, de, bh, offset))
1099 return -1;
1100 *res_dir = de;
1101 return 1;
1102 }
1103 /* prevent looping on a bad block */
1104 de_len = ext4_rec_len_from_disk(de->rec_len,
1105 dir->i_sb->s_blocksize);
1106 if (de_len <= 0)
1107 return -1;
1108 offset += de_len;
1109 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
1110 }
1111 return 0;
1112 }
1113
1114
1115 /*
1116 * ext4_find_entry()
1117 *
1118 * finds an entry in the specified directory with the wanted name. It
1119 * returns the cache buffer in which the entry was found, and the entry
1120 * itself (as a parameter - res_dir). It does NOT read the inode of the
1121 * entry - you'll have to do that yourself if you want to.
1122 *
1123 * The returned buffer_head has ->b_count elevated. The caller is expected
1124 * to brelse() it when appropriate.
1125 */
1126 static struct buffer_head * ext4_find_entry (struct inode *dir,
1127 const struct qstr *d_name,
1128 struct ext4_dir_entry_2 ** res_dir)
1129 {
1130 struct super_block *sb;
1131 struct buffer_head *bh_use[NAMEI_RA_SIZE];
1132 struct buffer_head *bh, *ret = NULL;
1133 ext4_lblk_t start, block, b;
1134 const u8 *name = d_name->name;
1135 int ra_max = 0; /* Number of bh's in the readahead
1136 buffer, bh_use[] */
1137 int ra_ptr = 0; /* Current index into readahead
1138 buffer */
1139 int num = 0;
1140 ext4_lblk_t nblocks;
1141 int i, err;
1142 int namelen;
1143
1144 *res_dir = NULL;
1145 sb = dir->i_sb;
1146 namelen = d_name->len;
1147 if (namelen > EXT4_NAME_LEN)
1148 return NULL;
1149 if ((namelen <= 2) && (name[0] == '.') &&
1150 (name[1] == '.' || name[1] == '\0')) {
1151 /*
1152 * "." or ".." will only be in the first block
1153 * NFS may look up ".."; "." should be handled by the VFS
1154 */
1155 block = start = 0;
1156 nblocks = 1;
1157 goto restart;
1158 }
1159 if (is_dx(dir)) {
1160 bh = ext4_dx_find_entry(dir, d_name, res_dir, &err);
1161 /*
1162 * On success, or if the error was file not found,
1163 * return. Otherwise, fall back to doing a search the
1164 * old fashioned way.
1165 */
1166 if (bh || (err != ERR_BAD_DX_DIR))
1167 return bh;
1168 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
1169 "falling back\n"));
1170 }
1171 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1172 start = EXT4_I(dir)->i_dir_start_lookup;
1173 if (start >= nblocks)
1174 start = 0;
1175 block = start;
1176 restart:
1177 do {
1178 /*
1179 * We deal with the read-ahead logic here.
1180 */
1181 if (ra_ptr >= ra_max) {
1182 /* Refill the readahead buffer */
1183 ra_ptr = 0;
1184 b = block;
1185 for (ra_max = 0; ra_max < NAMEI_RA_SIZE; ra_max++) {
1186 /*
1187 * Terminate if we reach the end of the
1188 * directory and must wrap, or if our
1189 * search has finished at this block.
1190 */
1191 if (b >= nblocks || (num && block == start)) {
1192 bh_use[ra_max] = NULL;
1193 break;
1194 }
1195 num++;
1196 bh = ext4_getblk(NULL, dir, b++, 0, &err);
1197 bh_use[ra_max] = bh;
1198 if (bh)
1199 ll_rw_block(READ | REQ_META | REQ_PRIO,
1200 1, &bh);
1201 }
1202 }
1203 if ((bh = bh_use[ra_ptr++]) == NULL)
1204 goto next;
1205 wait_on_buffer(bh);
1206 if (!buffer_uptodate(bh)) {
1207 /* read error, skip block & hope for the best */
1208 EXT4_ERROR_INODE(dir, "reading directory lblock %lu",
1209 (unsigned long) block);
1210 brelse(bh);
1211 goto next;
1212 }
1213 if (!buffer_verified(bh) &&
1214 !ext4_dirent_csum_verify(dir,
1215 (struct ext4_dir_entry *)bh->b_data)) {
1216 EXT4_ERROR_INODE(dir, "checksumming directory "
1217 "block %lu", (unsigned long)block);
1218 brelse(bh);
1219 goto next;
1220 }
1221 set_buffer_verified(bh);
1222 i = search_dirblock(bh, dir, d_name,
1223 block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
1224 if (i == 1) {
1225 EXT4_I(dir)->i_dir_start_lookup = block;
1226 ret = bh;
1227 goto cleanup_and_exit;
1228 } else {
1229 brelse(bh);
1230 if (i < 0)
1231 goto cleanup_and_exit;
1232 }
1233 next:
1234 if (++block >= nblocks)
1235 block = 0;
1236 } while (block != start);
1237
1238 /*
1239 * If the directory has grown while we were searching, then
1240 * search the last part of the directory before giving up.
1241 */
1242 block = nblocks;
1243 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1244 if (block < nblocks) {
1245 start = 0;
1246 goto restart;
1247 }
1248
1249 cleanup_and_exit:
1250 /* Clean up the read-ahead blocks */
1251 for (; ra_ptr < ra_max; ra_ptr++)
1252 brelse(bh_use[ra_ptr]);
1253 return ret;
1254 }
1255
1256 static struct buffer_head * ext4_dx_find_entry(struct inode *dir, const struct qstr *d_name,
1257 struct ext4_dir_entry_2 **res_dir, int *err)
1258 {
1259 struct super_block * sb = dir->i_sb;
1260 struct dx_hash_info hinfo;
1261 struct dx_frame frames[2], *frame;
1262 struct buffer_head *bh;
1263 ext4_lblk_t block;
1264 int retval;
1265
1266 if (!(frame = dx_probe(d_name, dir, &hinfo, frames, err)))
1267 return NULL;
1268 do {
1269 block = dx_get_block(frame->at);
1270 if (!(bh = ext4_bread(NULL, dir, block, 0, err)))
1271 goto errout;
1272
1273 if (!buffer_verified(bh) &&
1274 !ext4_dirent_csum_verify(dir,
1275 (struct ext4_dir_entry *)bh->b_data)) {
1276 EXT4_ERROR_INODE(dir, "checksumming directory "
1277 "block %lu", (unsigned long)block);
1278 brelse(bh);
1279 *err = -EIO;
1280 goto errout;
1281 }
1282 set_buffer_verified(bh);
1283 retval = search_dirblock(bh, dir, d_name,
1284 block << EXT4_BLOCK_SIZE_BITS(sb),
1285 res_dir);
1286 if (retval == 1) { /* Success! */
1287 dx_release(frames);
1288 return bh;
1289 }
1290 brelse(bh);
1291 if (retval == -1) {
1292 *err = ERR_BAD_DX_DIR;
1293 goto errout;
1294 }
1295
1296 /* Check to see if we should continue to search */
1297 retval = ext4_htree_next_block(dir, hinfo.hash, frame,
1298 frames, NULL);
1299 if (retval < 0) {
1300 ext4_warning(sb,
1301 "error reading index page in directory #%lu",
1302 dir->i_ino);
1303 *err = retval;
1304 goto errout;
1305 }
1306 } while (retval == 1);
1307
1308 *err = -ENOENT;
1309 errout:
1310 dxtrace(printk(KERN_DEBUG "%s not found\n", d_name->name));
1311 dx_release (frames);
1312 return NULL;
1313 }
1314
1315 static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
1316 {
1317 struct inode *inode;
1318 struct ext4_dir_entry_2 *de;
1319 struct buffer_head *bh;
1320
1321 if (dentry->d_name.len > EXT4_NAME_LEN)
1322 return ERR_PTR(-ENAMETOOLONG);
1323
1324 bh = ext4_find_entry(dir, &dentry->d_name, &de);
1325 inode = NULL;
1326 if (bh) {
1327 __u32 ino = le32_to_cpu(de->inode);
1328 brelse(bh);
1329 if (!ext4_valid_inum(dir->i_sb, ino)) {
1330 EXT4_ERROR_INODE(dir, "bad inode number: %u", ino);
1331 return ERR_PTR(-EIO);
1332 }
1333 if (unlikely(ino == dir->i_ino)) {
1334 EXT4_ERROR_INODE(dir, "'%.*s' linked to parent dir",
1335 dentry->d_name.len,
1336 dentry->d_name.name);
1337 return ERR_PTR(-EIO);
1338 }
1339 inode = ext4_iget(dir->i_sb, ino);
1340 if (inode == ERR_PTR(-ESTALE)) {
1341 EXT4_ERROR_INODE(dir,
1342 "deleted inode referenced: %u",
1343 ino);
1344 return ERR_PTR(-EIO);
1345 }
1346 }
1347 return d_splice_alias(inode, dentry);
1348 }
1349
1350
1351 struct dentry *ext4_get_parent(struct dentry *child)
1352 {
1353 __u32 ino;
1354 static const struct qstr dotdot = QSTR_INIT("..", 2);
1355 struct ext4_dir_entry_2 * de;
1356 struct buffer_head *bh;
1357
1358 bh = ext4_find_entry(child->d_inode, &dotdot, &de);
1359 if (!bh)
1360 return ERR_PTR(-ENOENT);
1361 ino = le32_to_cpu(de->inode);
1362 brelse(bh);
1363
1364 if (!ext4_valid_inum(child->d_inode->i_sb, ino)) {
1365 EXT4_ERROR_INODE(child->d_inode,
1366 "bad parent inode number: %u", ino);
1367 return ERR_PTR(-EIO);
1368 }
1369
1370 return d_obtain_alias(ext4_iget(child->d_inode->i_sb, ino));
1371 }
1372
1373 #define S_SHIFT 12
1374 static unsigned char ext4_type_by_mode[S_IFMT >> S_SHIFT] = {
1375 [S_IFREG >> S_SHIFT] = EXT4_FT_REG_FILE,
1376 [S_IFDIR >> S_SHIFT] = EXT4_FT_DIR,
1377 [S_IFCHR >> S_SHIFT] = EXT4_FT_CHRDEV,
1378 [S_IFBLK >> S_SHIFT] = EXT4_FT_BLKDEV,
1379 [S_IFIFO >> S_SHIFT] = EXT4_FT_FIFO,
1380 [S_IFSOCK >> S_SHIFT] = EXT4_FT_SOCK,
1381 [S_IFLNK >> S_SHIFT] = EXT4_FT_SYMLINK,
1382 };
1383
1384 static inline void ext4_set_de_type(struct super_block *sb,
1385 struct ext4_dir_entry_2 *de,
1386 umode_t mode) {
1387 if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE))
1388 de->file_type = ext4_type_by_mode[(mode & S_IFMT)>>S_SHIFT];
1389 }
1390
1391 /*
1392 * Move count entries from end of map between two memory locations.
1393 * Returns pointer to last entry moved.
1394 */
1395 static struct ext4_dir_entry_2 *
1396 dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count,
1397 unsigned blocksize)
1398 {
1399 unsigned rec_len = 0;
1400
1401 while (count--) {
1402 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
1403 (from + (map->offs<<2));
1404 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1405 memcpy (to, de, rec_len);
1406 ((struct ext4_dir_entry_2 *) to)->rec_len =
1407 ext4_rec_len_to_disk(rec_len, blocksize);
1408 de->inode = 0;
1409 map++;
1410 to += rec_len;
1411 }
1412 return (struct ext4_dir_entry_2 *) (to - rec_len);
1413 }
1414
1415 /*
1416 * Compact each dir entry in the range to the minimal rec_len.
1417 * Returns pointer to last entry in range.
1418 */
1419 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize)
1420 {
1421 struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
1422 unsigned rec_len = 0;
1423
1424 prev = to = de;
1425 while ((char*)de < base + blocksize) {
1426 next = ext4_next_entry(de, blocksize);
1427 if (de->inode && de->name_len) {
1428 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1429 if (de > to)
1430 memmove(to, de, rec_len);
1431 to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
1432 prev = to;
1433 to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
1434 }
1435 de = next;
1436 }
1437 return prev;
1438 }
1439
1440 /*
1441 * Split a full leaf block to make room for a new dir entry.
1442 * Allocate a new block, and move entries so that they are approx. equally full.
1443 * Returns pointer to de in block into which the new entry will be inserted.
1444 */
1445 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
1446 struct buffer_head **bh,struct dx_frame *frame,
1447 struct dx_hash_info *hinfo, int *error)
1448 {
1449 unsigned blocksize = dir->i_sb->s_blocksize;
1450 unsigned count, continued;
1451 struct buffer_head *bh2;
1452 ext4_lblk_t newblock;
1453 u32 hash2;
1454 struct dx_map_entry *map;
1455 char *data1 = (*bh)->b_data, *data2;
1456 unsigned split, move, size;
1457 struct ext4_dir_entry_2 *de = NULL, *de2;
1458 struct ext4_dir_entry_tail *t;
1459 int csum_size = 0;
1460 int err = 0, i;
1461
1462 if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
1463 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
1464 csum_size = sizeof(struct ext4_dir_entry_tail);
1465
1466 bh2 = ext4_append (handle, dir, &newblock, &err);
1467 if (!(bh2)) {
1468 brelse(*bh);
1469 *bh = NULL;
1470 goto errout;
1471 }
1472
1473 BUFFER_TRACE(*bh, "get_write_access");
1474 err = ext4_journal_get_write_access(handle, *bh);
1475 if (err)
1476 goto journal_error;
1477
1478 BUFFER_TRACE(frame->bh, "get_write_access");
1479 err = ext4_journal_get_write_access(handle, frame->bh);
1480 if (err)
1481 goto journal_error;
1482
1483 data2 = bh2->b_data;
1484
1485 /* create map in the end of data2 block */
1486 map = (struct dx_map_entry *) (data2 + blocksize);
1487 count = dx_make_map((struct ext4_dir_entry_2 *) data1,
1488 blocksize, hinfo, map);
1489 map -= count;
1490 dx_sort_map(map, count);
1491 /* Split the existing block in the middle, size-wise */
1492 size = 0;
1493 move = 0;
1494 for (i = count-1; i >= 0; i--) {
1495 /* is more than half of this entry in 2nd half of the block? */
1496 if (size + map[i].size/2 > blocksize/2)
1497 break;
1498 size += map[i].size;
1499 move++;
1500 }
1501 /* map index at which we will split */
1502 split = count - move;
1503 hash2 = map[split].hash;
1504 continued = hash2 == map[split - 1].hash;
1505 dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
1506 (unsigned long)dx_get_block(frame->at),
1507 hash2, split, count-split));
1508
1509 /* Fancy dance to stay within two buffers */
1510 de2 = dx_move_dirents(data1, data2, map + split, count - split, blocksize);
1511 de = dx_pack_dirents(data1, blocksize);
1512 de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
1513 (char *) de,
1514 blocksize);
1515 de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
1516 (char *) de2,
1517 blocksize);
1518 if (csum_size) {
1519 t = EXT4_DIRENT_TAIL(data2, blocksize);
1520 initialize_dirent_tail(t, blocksize);
1521
1522 t = EXT4_DIRENT_TAIL(data1, blocksize);
1523 initialize_dirent_tail(t, blocksize);
1524 }
1525
1526 dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data1, blocksize, 1));
1527 dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data2, blocksize, 1));
1528
1529 /* Which block gets the new entry? */
1530 if (hinfo->hash >= hash2)
1531 {
1532 swap(*bh, bh2);
1533 de = de2;
1534 }
1535 dx_insert_block(frame, hash2 + continued, newblock);
1536 err = ext4_handle_dirty_dirent_node(handle, dir, bh2);
1537 if (err)
1538 goto journal_error;
1539 err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
1540 if (err)
1541 goto journal_error;
1542 brelse(bh2);
1543 dxtrace(dx_show_index("frame", frame->entries));
1544 return de;
1545
1546 journal_error:
1547 brelse(*bh);
1548 brelse(bh2);
1549 *bh = NULL;
1550 ext4_std_error(dir->i_sb, err);
1551 errout:
1552 *error = err;
1553 return NULL;
1554 }
1555
1556 /*
1557 * Add a new entry into a directory (leaf) block. If de is non-NULL,
1558 * it points to a directory entry which is guaranteed to be large
1559 * enough for new directory entry. If de is NULL, then
1560 * add_dirent_to_buf will attempt search the directory block for
1561 * space. It will return -ENOSPC if no space is available, and -EIO
1562 * and -EEXIST if directory entry already exists.
1563 */
1564 static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
1565 struct inode *inode, struct ext4_dir_entry_2 *de,
1566 struct buffer_head *bh)
1567 {
1568 struct inode *dir = dentry->d_parent->d_inode;
1569 const char *name = dentry->d_name.name;
1570 int namelen = dentry->d_name.len;
1571 unsigned int offset = 0;
1572 unsigned int blocksize = dir->i_sb->s_blocksize;
1573 unsigned short reclen;
1574 int nlen, rlen, err;
1575 char *top;
1576 int csum_size = 0;
1577
1578 if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
1579 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
1580 csum_size = sizeof(struct ext4_dir_entry_tail);
1581
1582 reclen = EXT4_DIR_REC_LEN(namelen);
1583 if (!de) {
1584 de = (struct ext4_dir_entry_2 *)bh->b_data;
1585 top = bh->b_data + (blocksize - csum_size) - reclen;
1586 while ((char *) de <= top) {
1587 if (ext4_check_dir_entry(dir, NULL, de, bh, offset))
1588 return -EIO;
1589 if (ext4_match(namelen, name, de))
1590 return -EEXIST;
1591 nlen = EXT4_DIR_REC_LEN(de->name_len);
1592 rlen = ext4_rec_len_from_disk(de->rec_len, blocksize);
1593 if ((de->inode? rlen - nlen: rlen) >= reclen)
1594 break;
1595 de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
1596 offset += rlen;
1597 }
1598 if ((char *) de > top)
1599 return -ENOSPC;
1600 }
1601 BUFFER_TRACE(bh, "get_write_access");
1602 err = ext4_journal_get_write_access(handle, bh);
1603 if (err) {
1604 ext4_std_error(dir->i_sb, err);
1605 return err;
1606 }
1607
1608 /* By now the buffer is marked for journaling */
1609 nlen = EXT4_DIR_REC_LEN(de->name_len);
1610 rlen = ext4_rec_len_from_disk(de->rec_len, blocksize);
1611 if (de->inode) {
1612 struct ext4_dir_entry_2 *de1 = (struct ext4_dir_entry_2 *)((char *)de + nlen);
1613 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, blocksize);
1614 de->rec_len = ext4_rec_len_to_disk(nlen, blocksize);
1615 de = de1;
1616 }
1617 de->file_type = EXT4_FT_UNKNOWN;
1618 de->inode = cpu_to_le32(inode->i_ino);
1619 ext4_set_de_type(dir->i_sb, de, inode->i_mode);
1620 de->name_len = namelen;
1621 memcpy(de->name, name, namelen);
1622 /*
1623 * XXX shouldn't update any times until successful
1624 * completion of syscall, but too many callers depend
1625 * on this.
1626 *
1627 * XXX similarly, too many callers depend on
1628 * ext4_new_inode() setting the times, but error
1629 * recovery deletes the inode, so the worst that can
1630 * happen is that the times are slightly out of date
1631 * and/or different from the directory change time.
1632 */
1633 dir->i_mtime = dir->i_ctime = ext4_current_time(dir);
1634 ext4_update_dx_flag(dir);
1635 dir->i_version++;
1636 ext4_mark_inode_dirty(handle, dir);
1637 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1638 err = ext4_handle_dirty_dirent_node(handle, dir, bh);
1639 if (err)
1640 ext4_std_error(dir->i_sb, err);
1641 return 0;
1642 }
1643
1644 /*
1645 * This converts a one block unindexed directory to a 3 block indexed
1646 * directory, and adds the dentry to the indexed directory.
1647 */
1648 static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
1649 struct inode *inode, struct buffer_head *bh)
1650 {
1651 struct inode *dir = dentry->d_parent->d_inode;
1652 const char *name = dentry->d_name.name;
1653 int namelen = dentry->d_name.len;
1654 struct buffer_head *bh2;
1655 struct dx_root *root;
1656 struct dx_frame frames[2], *frame;
1657 struct dx_entry *entries;
1658 struct ext4_dir_entry_2 *de, *de2;
1659 struct ext4_dir_entry_tail *t;
1660 char *data1, *top;
1661 unsigned len;
1662 int retval;
1663 unsigned blocksize;
1664 struct dx_hash_info hinfo;
1665 ext4_lblk_t block;
1666 struct fake_dirent *fde;
1667 int csum_size = 0;
1668
1669 if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
1670 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
1671 csum_size = sizeof(struct ext4_dir_entry_tail);
1672
1673 blocksize = dir->i_sb->s_blocksize;
1674 dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
1675 retval = ext4_journal_get_write_access(handle, bh);
1676 if (retval) {
1677 ext4_std_error(dir->i_sb, retval);
1678 brelse(bh);
1679 return retval;
1680 }
1681 root = (struct dx_root *) bh->b_data;
1682
1683 /* The 0th block becomes the root, move the dirents out */
1684 fde = &root->dotdot;
1685 de = (struct ext4_dir_entry_2 *)((char *)fde +
1686 ext4_rec_len_from_disk(fde->rec_len, blocksize));
1687 if ((char *) de >= (((char *) root) + blocksize)) {
1688 EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
1689 brelse(bh);
1690 return -EIO;
1691 }
1692 len = ((char *) root) + (blocksize - csum_size) - (char *) de;
1693
1694 /* Allocate new block for the 0th block's dirents */
1695 bh2 = ext4_append(handle, dir, &block, &retval);
1696 if (!(bh2)) {
1697 brelse(bh);
1698 return retval;
1699 }
1700 ext4_set_inode_flag(dir, EXT4_INODE_INDEX);
1701 data1 = bh2->b_data;
1702
1703 memcpy (data1, de, len);
1704 de = (struct ext4_dir_entry_2 *) data1;
1705 top = data1 + len;
1706 while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
1707 de = de2;
1708 de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
1709 (char *) de,
1710 blocksize);
1711
1712 if (csum_size) {
1713 t = EXT4_DIRENT_TAIL(data1, blocksize);
1714 initialize_dirent_tail(t, blocksize);
1715 }
1716
1717 /* Initialize the root; the dot dirents already exist */
1718 de = (struct ext4_dir_entry_2 *) (&root->dotdot);
1719 de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
1720 blocksize);
1721 memset (&root->info, 0, sizeof(root->info));
1722 root->info.info_length = sizeof(root->info);
1723 root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
1724 entries = root->entries;
1725 dx_set_block(entries, 1);
1726 dx_set_count(entries, 1);
1727 dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
1728
1729 /* Initialize as for dx_probe */
1730 hinfo.hash_version = root->info.hash_version;
1731 if (hinfo.hash_version <= DX_HASH_TEA)
1732 hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
1733 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
1734 ext4fs_dirhash(name, namelen, &hinfo);
1735 frame = frames;
1736 frame->entries = entries;
1737 frame->at = entries;
1738 frame->bh = bh;
1739 bh = bh2;
1740
1741 ext4_handle_dirty_dx_node(handle, dir, frame->bh);
1742 ext4_handle_dirty_dirent_node(handle, dir, bh);
1743
1744 de = do_split(handle,dir, &bh, frame, &hinfo, &retval);
1745 if (!de) {
1746 /*
1747 * Even if the block split failed, we have to properly write
1748 * out all the changes we did so far. Otherwise we can end up
1749 * with corrupted filesystem.
1750 */
1751 ext4_mark_inode_dirty(handle, dir);
1752 dx_release(frames);
1753 return retval;
1754 }
1755 dx_release(frames);
1756
1757 retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
1758 brelse(bh);
1759 return retval;
1760 }
1761
1762 /*
1763 * ext4_add_entry()
1764 *
1765 * adds a file entry to the specified directory, using the same
1766 * semantics as ext4_find_entry(). It returns NULL if it failed.
1767 *
1768 * NOTE!! The inode part of 'de' is left at 0 - which means you
1769 * may not sleep between calling this and putting something into
1770 * the entry, as someone else might have used it while you slept.
1771 */
1772 static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
1773 struct inode *inode)
1774 {
1775 struct inode *dir = dentry->d_parent->d_inode;
1776 struct buffer_head *bh;
1777 struct ext4_dir_entry_2 *de;
1778 struct ext4_dir_entry_tail *t;
1779 struct super_block *sb;
1780 int retval;
1781 int dx_fallback=0;
1782 unsigned blocksize;
1783 ext4_lblk_t block, blocks;
1784 int csum_size = 0;
1785
1786 if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
1787 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
1788 csum_size = sizeof(struct ext4_dir_entry_tail);
1789
1790 sb = dir->i_sb;
1791 blocksize = sb->s_blocksize;
1792 if (!dentry->d_name.len)
1793 return -EINVAL;
1794 if (is_dx(dir)) {
1795 retval = ext4_dx_add_entry(handle, dentry, inode);
1796 if (!retval || (retval != ERR_BAD_DX_DIR))
1797 return retval;
1798 ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
1799 dx_fallback++;
1800 ext4_mark_inode_dirty(handle, dir);
1801 }
1802 blocks = dir->i_size >> sb->s_blocksize_bits;
1803 for (block = 0; block < blocks; block++) {
1804 bh = ext4_bread(handle, dir, block, 0, &retval);
1805 if(!bh)
1806 return retval;
1807 if (!buffer_verified(bh) &&
1808 !ext4_dirent_csum_verify(dir,
1809 (struct ext4_dir_entry *)bh->b_data))
1810 return -EIO;
1811 set_buffer_verified(bh);
1812 retval = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
1813 if (retval != -ENOSPC) {
1814 brelse(bh);
1815 return retval;
1816 }
1817
1818 if (blocks == 1 && !dx_fallback &&
1819 EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX))
1820 return make_indexed_dir(handle, dentry, inode, bh);
1821 brelse(bh);
1822 }
1823 bh = ext4_append(handle, dir, &block, &retval);
1824 if (!bh)
1825 return retval;
1826 de = (struct ext4_dir_entry_2 *) bh->b_data;
1827 de->inode = 0;
1828 de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize);
1829
1830 if (csum_size) {
1831 t = EXT4_DIRENT_TAIL(bh->b_data, blocksize);
1832 initialize_dirent_tail(t, blocksize);
1833 }
1834
1835 retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
1836 brelse(bh);
1837 if (retval == 0)
1838 ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY);
1839 return retval;
1840 }
1841
1842 /*
1843 * Returns 0 for success, or a negative error value
1844 */
1845 static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
1846 struct inode *inode)
1847 {
1848 struct dx_frame frames[2], *frame;
1849 struct dx_entry *entries, *at;
1850 struct dx_hash_info hinfo;
1851 struct buffer_head *bh;
1852 struct inode *dir = dentry->d_parent->d_inode;
1853 struct super_block *sb = dir->i_sb;
1854 struct ext4_dir_entry_2 *de;
1855 int err;
1856
1857 frame = dx_probe(&dentry->d_name, dir, &hinfo, frames, &err);
1858 if (!frame)
1859 return err;
1860 entries = frame->entries;
1861 at = frame->at;
1862
1863 if (!(bh = ext4_bread(handle,dir, dx_get_block(frame->at), 0, &err)))
1864 goto cleanup;
1865
1866 if (!buffer_verified(bh) &&
1867 !ext4_dirent_csum_verify(dir, (struct ext4_dir_entry *)bh->b_data))
1868 goto journal_error;
1869 set_buffer_verified(bh);
1870
1871 BUFFER_TRACE(bh, "get_write_access");
1872 err = ext4_journal_get_write_access(handle, bh);
1873 if (err)
1874 goto journal_error;
1875
1876 err = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
1877 if (err != -ENOSPC)
1878 goto cleanup;
1879
1880 /* Block full, should compress but for now just split */
1881 dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
1882 dx_get_count(entries), dx_get_limit(entries)));
1883 /* Need to split index? */
1884 if (dx_get_count(entries) == dx_get_limit(entries)) {
1885 ext4_lblk_t newblock;
1886 unsigned icount = dx_get_count(entries);
1887 int levels = frame - frames;
1888 struct dx_entry *entries2;
1889 struct dx_node *node2;
1890 struct buffer_head *bh2;
1891
1892 if (levels && (dx_get_count(frames->entries) ==
1893 dx_get_limit(frames->entries))) {
1894 ext4_warning(sb, "Directory index full!");
1895 err = -ENOSPC;
1896 goto cleanup;
1897 }
1898 bh2 = ext4_append (handle, dir, &newblock, &err);
1899 if (!(bh2))
1900 goto cleanup;
1901 node2 = (struct dx_node *)(bh2->b_data);
1902 entries2 = node2->entries;
1903 memset(&node2->fake, 0, sizeof(struct fake_dirent));
1904 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
1905 sb->s_blocksize);
1906 BUFFER_TRACE(frame->bh, "get_write_access");
1907 err = ext4_journal_get_write_access(handle, frame->bh);
1908 if (err)
1909 goto journal_error;
1910 if (levels) {
1911 unsigned icount1 = icount/2, icount2 = icount - icount1;
1912 unsigned hash2 = dx_get_hash(entries + icount1);
1913 dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
1914 icount1, icount2));
1915
1916 BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
1917 err = ext4_journal_get_write_access(handle,
1918 frames[0].bh);
1919 if (err)
1920 goto journal_error;
1921
1922 memcpy((char *) entries2, (char *) (entries + icount1),
1923 icount2 * sizeof(struct dx_entry));
1924 dx_set_count(entries, icount1);
1925 dx_set_count(entries2, icount2);
1926 dx_set_limit(entries2, dx_node_limit(dir));
1927
1928 /* Which index block gets the new entry? */
1929 if (at - entries >= icount1) {
1930 frame->at = at = at - entries - icount1 + entries2;
1931 frame->entries = entries = entries2;
1932 swap(frame->bh, bh2);
1933 }
1934 dx_insert_block(frames + 0, hash2, newblock);
1935 dxtrace(dx_show_index("node", frames[1].entries));
1936 dxtrace(dx_show_index("node",
1937 ((struct dx_node *) bh2->b_data)->entries));
1938 err = ext4_handle_dirty_dx_node(handle, dir, bh2);
1939 if (err)
1940 goto journal_error;
1941 brelse (bh2);
1942 } else {
1943 dxtrace(printk(KERN_DEBUG
1944 "Creating second level index...\n"));
1945 memcpy((char *) entries2, (char *) entries,
1946 icount * sizeof(struct dx_entry));
1947 dx_set_limit(entries2, dx_node_limit(dir));
1948
1949 /* Set up root */
1950 dx_set_count(entries, 1);
1951 dx_set_block(entries + 0, newblock);
1952 ((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels = 1;
1953
1954 /* Add new access path frame */
1955 frame = frames + 1;
1956 frame->at = at = at - entries + entries2;
1957 frame->entries = entries = entries2;
1958 frame->bh = bh2;
1959 err = ext4_journal_get_write_access(handle,
1960 frame->bh);
1961 if (err)
1962 goto journal_error;
1963 }
1964 err = ext4_handle_dirty_dx_node(handle, dir, frames[0].bh);
1965 if (err) {
1966 ext4_std_error(inode->i_sb, err);
1967 goto cleanup;
1968 }
1969 }
1970 de = do_split(handle, dir, &bh, frame, &hinfo, &err);
1971 if (!de)
1972 goto cleanup;
1973 err = add_dirent_to_buf(handle, dentry, inode, de, bh);
1974 goto cleanup;
1975
1976 journal_error:
1977 ext4_std_error(dir->i_sb, err);
1978 cleanup:
1979 if (bh)
1980 brelse(bh);
1981 dx_release(frames);
1982 return err;
1983 }
1984
1985 /*
1986 * ext4_delete_entry deletes a directory entry by merging it with the
1987 * previous entry
1988 */
1989 static int ext4_delete_entry(handle_t *handle,
1990 struct inode *dir,
1991 struct ext4_dir_entry_2 *de_del,
1992 struct buffer_head *bh)
1993 {
1994 struct ext4_dir_entry_2 *de, *pde;
1995 unsigned int blocksize = dir->i_sb->s_blocksize;
1996 int csum_size = 0;
1997 int i, err;
1998
1999 if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
2000 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
2001 csum_size = sizeof(struct ext4_dir_entry_tail);
2002
2003 i = 0;
2004 pde = NULL;
2005 de = (struct ext4_dir_entry_2 *) bh->b_data;
2006 while (i < bh->b_size - csum_size) {
2007 if (ext4_check_dir_entry(dir, NULL, de, bh, i))
2008 return -EIO;
2009 if (de == de_del) {
2010 BUFFER_TRACE(bh, "get_write_access");
2011 err = ext4_journal_get_write_access(handle, bh);
2012 if (unlikely(err)) {
2013 ext4_std_error(dir->i_sb, err);
2014 return err;
2015 }
2016 if (pde)
2017 pde->rec_len = ext4_rec_len_to_disk(
2018 ext4_rec_len_from_disk(pde->rec_len,
2019 blocksize) +
2020 ext4_rec_len_from_disk(de->rec_len,
2021 blocksize),
2022 blocksize);
2023 else
2024 de->inode = 0;
2025 dir->i_version++;
2026 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
2027 err = ext4_handle_dirty_dirent_node(handle, dir, bh);
2028 if (unlikely(err)) {
2029 ext4_std_error(dir->i_sb, err);
2030 return err;
2031 }
2032 return 0;
2033 }
2034 i += ext4_rec_len_from_disk(de->rec_len, blocksize);
2035 pde = de;
2036 de = ext4_next_entry(de, blocksize);
2037 }
2038 return -ENOENT;
2039 }
2040
2041 /*
2042 * DIR_NLINK feature is set if 1) nlinks > EXT4_LINK_MAX or 2) nlinks == 2,
2043 * since this indicates that nlinks count was previously 1.
2044 */
2045 static void ext4_inc_count(handle_t *handle, struct inode *inode)
2046 {
2047 inc_nlink(inode);
2048 if (is_dx(inode) && inode->i_nlink > 1) {
2049 /* limit is 16-bit i_links_count */
2050 if (inode->i_nlink >= EXT4_LINK_MAX || inode->i_nlink == 2) {
2051 set_nlink(inode, 1);
2052 EXT4_SET_RO_COMPAT_FEATURE(inode->i_sb,
2053 EXT4_FEATURE_RO_COMPAT_DIR_NLINK);
2054 }
2055 }
2056 }
2057
2058 /*
2059 * If a directory had nlink == 1, then we should let it be 1. This indicates
2060 * directory has >EXT4_LINK_MAX subdirs.
2061 */
2062 static void ext4_dec_count(handle_t *handle, struct inode *inode)
2063 {
2064 if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
2065 drop_nlink(inode);
2066 }
2067
2068
2069 static int ext4_add_nondir(handle_t *handle,
2070 struct dentry *dentry, struct inode *inode)
2071 {
2072 int err = ext4_add_entry(handle, dentry, inode);
2073 if (!err) {
2074 ext4_mark_inode_dirty(handle, inode);
2075 unlock_new_inode(inode);
2076 d_instantiate(dentry, inode);
2077 return 0;
2078 }
2079 drop_nlink(inode);
2080 unlock_new_inode(inode);
2081 iput(inode);
2082 return err;
2083 }
2084
2085 /*
2086 * By the time this is called, we already have created
2087 * the directory cache entry for the new file, but it
2088 * is so far negative - it has no inode.
2089 *
2090 * If the create succeeds, we fill in the inode information
2091 * with d_instantiate().
2092 */
2093 static int ext4_create(struct inode *dir, struct dentry *dentry, umode_t mode,
2094 bool excl)
2095 {
2096 handle_t *handle;
2097 struct inode *inode;
2098 int err, retries = 0;
2099
2100 dquot_initialize(dir);
2101
2102 retry:
2103 handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2104 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
2105 EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
2106 if (IS_ERR(handle))
2107 return PTR_ERR(handle);
2108
2109 if (IS_DIRSYNC(dir))
2110 ext4_handle_sync(handle);
2111
2112 inode = ext4_new_inode(handle, dir, mode, &dentry->d_name, 0, NULL);
2113 err = PTR_ERR(inode);
2114 if (!IS_ERR(inode)) {
2115 inode->i_op = &ext4_file_inode_operations;
2116 inode->i_fop = &ext4_file_operations;
2117 ext4_set_aops(inode);
2118 err = ext4_add_nondir(handle, dentry, inode);
2119 }
2120 ext4_journal_stop(handle);
2121 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2122 goto retry;
2123 return err;
2124 }
2125
2126 static int ext4_mknod(struct inode *dir, struct dentry *dentry,
2127 umode_t mode, dev_t rdev)
2128 {
2129 handle_t *handle;
2130 struct inode *inode;
2131 int err, retries = 0;
2132
2133 if (!new_valid_dev(rdev))
2134 return -EINVAL;
2135
2136 dquot_initialize(dir);
2137
2138 retry:
2139 handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2140 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
2141 EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
2142 if (IS_ERR(handle))
2143 return PTR_ERR(handle);
2144
2145 if (IS_DIRSYNC(dir))
2146 ext4_handle_sync(handle);
2147
2148 inode = ext4_new_inode(handle, dir, mode, &dentry->d_name, 0, NULL);
2149 err = PTR_ERR(inode);
2150 if (!IS_ERR(inode)) {
2151 init_special_inode(inode, inode->i_mode, rdev);
2152 inode->i_op = &ext4_special_inode_operations;
2153 err = ext4_add_nondir(handle, dentry, inode);
2154 }
2155 ext4_journal_stop(handle);
2156 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2157 goto retry;
2158 return err;
2159 }
2160
2161 static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
2162 {
2163 handle_t *handle;
2164 struct inode *inode;
2165 struct buffer_head *dir_block = NULL;
2166 struct ext4_dir_entry_2 *de;
2167 struct ext4_dir_entry_tail *t;
2168 unsigned int blocksize = dir->i_sb->s_blocksize;
2169 int csum_size = 0;
2170 int err, retries = 0;
2171
2172 if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
2173 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
2174 csum_size = sizeof(struct ext4_dir_entry_tail);
2175
2176 if (EXT4_DIR_LINK_MAX(dir))
2177 return -EMLINK;
2178
2179 dquot_initialize(dir);
2180
2181 retry:
2182 handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2183 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
2184 EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
2185 if (IS_ERR(handle))
2186 return PTR_ERR(handle);
2187
2188 if (IS_DIRSYNC(dir))
2189 ext4_handle_sync(handle);
2190
2191 inode = ext4_new_inode(handle, dir, S_IFDIR | mode,
2192 &dentry->d_name, 0, NULL);
2193 err = PTR_ERR(inode);
2194 if (IS_ERR(inode))
2195 goto out_stop;
2196
2197 inode->i_op = &ext4_dir_inode_operations;
2198 inode->i_fop = &ext4_dir_operations;
2199 inode->i_size = EXT4_I(inode)->i_disksize = inode->i_sb->s_blocksize;
2200 dir_block = ext4_bread(handle, inode, 0, 1, &err);
2201 if (!dir_block)
2202 goto out_clear_inode;
2203 BUFFER_TRACE(dir_block, "get_write_access");
2204 err = ext4_journal_get_write_access(handle, dir_block);
2205 if (err)
2206 goto out_clear_inode;
2207 de = (struct ext4_dir_entry_2 *) dir_block->b_data;
2208 de->inode = cpu_to_le32(inode->i_ino);
2209 de->name_len = 1;
2210 de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
2211 blocksize);
2212 strcpy(de->name, ".");
2213 ext4_set_de_type(dir->i_sb, de, S_IFDIR);
2214 de = ext4_next_entry(de, blocksize);
2215 de->inode = cpu_to_le32(dir->i_ino);
2216 de->rec_len = ext4_rec_len_to_disk(blocksize -
2217 (csum_size + EXT4_DIR_REC_LEN(1)),
2218 blocksize);
2219 de->name_len = 2;
2220 strcpy(de->name, "..");
2221 ext4_set_de_type(dir->i_sb, de, S_IFDIR);
2222 set_nlink(inode, 2);
2223
2224 if (csum_size) {
2225 t = EXT4_DIRENT_TAIL(dir_block->b_data, blocksize);
2226 initialize_dirent_tail(t, blocksize);
2227 }
2228
2229 BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
2230 err = ext4_handle_dirty_dirent_node(handle, inode, dir_block);
2231 if (err)
2232 goto out_clear_inode;
2233 set_buffer_verified(dir_block);
2234 err = ext4_mark_inode_dirty(handle, inode);
2235 if (!err)
2236 err = ext4_add_entry(handle, dentry, inode);
2237 if (err) {
2238 out_clear_inode:
2239 clear_nlink(inode);
2240 unlock_new_inode(inode);
2241 ext4_mark_inode_dirty(handle, inode);
2242 iput(inode);
2243 goto out_stop;
2244 }
2245 ext4_inc_count(handle, dir);
2246 ext4_update_dx_flag(dir);
2247 err = ext4_mark_inode_dirty(handle, dir);
2248 if (err)
2249 goto out_clear_inode;
2250 unlock_new_inode(inode);
2251 d_instantiate(dentry, inode);
2252 out_stop:
2253 brelse(dir_block);
2254 ext4_journal_stop(handle);
2255 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2256 goto retry;
2257 return err;
2258 }
2259
2260 /*
2261 * routine to check that the specified directory is empty (for rmdir)
2262 */
2263 static int empty_dir(struct inode *inode)
2264 {
2265 unsigned int offset;
2266 struct buffer_head *bh;
2267 struct ext4_dir_entry_2 *de, *de1;
2268 struct super_block *sb;
2269 int err = 0;
2270
2271 sb = inode->i_sb;
2272 if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2) ||
2273 !(bh = ext4_bread(NULL, inode, 0, 0, &err))) {
2274 if (err)
2275 EXT4_ERROR_INODE(inode,
2276 "error %d reading directory lblock 0", err);
2277 else
2278 ext4_warning(inode->i_sb,
2279 "bad directory (dir #%lu) - no data block",
2280 inode->i_ino);
2281 return 1;
2282 }
2283 if (!buffer_verified(bh) &&
2284 !ext4_dirent_csum_verify(inode,
2285 (struct ext4_dir_entry *)bh->b_data)) {
2286 EXT4_ERROR_INODE(inode, "checksum error reading directory "
2287 "lblock 0");
2288 return -EIO;
2289 }
2290 set_buffer_verified(bh);
2291 de = (struct ext4_dir_entry_2 *) bh->b_data;
2292 de1 = ext4_next_entry(de, sb->s_blocksize);
2293 if (le32_to_cpu(de->inode) != inode->i_ino ||
2294 !le32_to_cpu(de1->inode) ||
2295 strcmp(".", de->name) ||
2296 strcmp("..", de1->name)) {
2297 ext4_warning(inode->i_sb,
2298 "bad directory (dir #%lu) - no `.' or `..'",
2299 inode->i_ino);
2300 brelse(bh);
2301 return 1;
2302 }
2303 offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) +
2304 ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize);
2305 de = ext4_next_entry(de1, sb->s_blocksize);
2306 while (offset < inode->i_size) {
2307 if (!bh ||
2308 (void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
2309 unsigned int lblock;
2310 err = 0;
2311 brelse(bh);
2312 lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb);
2313 bh = ext4_bread(NULL, inode, lblock, 0, &err);
2314 if (!bh) {
2315 if (err)
2316 EXT4_ERROR_INODE(inode,
2317 "error %d reading directory "
2318 "lblock %u", err, lblock);
2319 offset += sb->s_blocksize;
2320 continue;
2321 }
2322 if (!buffer_verified(bh) &&
2323 !ext4_dirent_csum_verify(inode,
2324 (struct ext4_dir_entry *)bh->b_data)) {
2325 EXT4_ERROR_INODE(inode, "checksum error "
2326 "reading directory lblock 0");
2327 return -EIO;
2328 }
2329 set_buffer_verified(bh);
2330 de = (struct ext4_dir_entry_2 *) bh->b_data;
2331 }
2332 if (ext4_check_dir_entry(inode, NULL, de, bh, offset)) {
2333 de = (struct ext4_dir_entry_2 *)(bh->b_data +
2334 sb->s_blocksize);
2335 offset = (offset | (sb->s_blocksize - 1)) + 1;
2336 continue;
2337 }
2338 if (le32_to_cpu(de->inode)) {
2339 brelse(bh);
2340 return 0;
2341 }
2342 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
2343 de = ext4_next_entry(de, sb->s_blocksize);
2344 }
2345 brelse(bh);
2346 return 1;
2347 }
2348
2349 /* ext4_orphan_add() links an unlinked or truncated inode into a list of
2350 * such inodes, starting at the superblock, in case we crash before the
2351 * file is closed/deleted, or in case the inode truncate spans multiple
2352 * transactions and the last transaction is not recovered after a crash.
2353 *
2354 * At filesystem recovery time, we walk this list deleting unlinked
2355 * inodes and truncating linked inodes in ext4_orphan_cleanup().
2356 */
2357 int ext4_orphan_add(handle_t *handle, struct inode *inode)
2358 {
2359 struct super_block *sb = inode->i_sb;
2360 struct ext4_iloc iloc;
2361 int err = 0, rc;
2362
2363 if (!ext4_handle_valid(handle))
2364 return 0;
2365
2366 mutex_lock(&EXT4_SB(sb)->s_orphan_lock);
2367 if (!list_empty(&EXT4_I(inode)->i_orphan))
2368 goto out_unlock;
2369
2370 /*
2371 * Orphan handling is only valid for files with data blocks
2372 * being truncated, or files being unlinked. Note that we either
2373 * hold i_mutex, or the inode can not be referenced from outside,
2374 * so i_nlink should not be bumped due to race
2375 */
2376 J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2377 S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
2378
2379 BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access");
2380 err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
2381 if (err)
2382 goto out_unlock;
2383
2384 err = ext4_reserve_inode_write(handle, inode, &iloc);
2385 if (err)
2386 goto out_unlock;
2387 /*
2388 * Due to previous errors inode may be already a part of on-disk
2389 * orphan list. If so skip on-disk list modification.
2390 */
2391 if (NEXT_ORPHAN(inode) && NEXT_ORPHAN(inode) <=
2392 (le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count)))
2393 goto mem_insert;
2394
2395 /* Insert this inode at the head of the on-disk orphan list... */
2396 NEXT_ORPHAN(inode) = le32_to_cpu(EXT4_SB(sb)->s_es->s_last_orphan);
2397 EXT4_SB(sb)->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
2398 err = ext4_handle_dirty_super(handle, sb);
2399 rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
2400 if (!err)
2401 err = rc;
2402
2403 /* Only add to the head of the in-memory list if all the
2404 * previous operations succeeded. If the orphan_add is going to
2405 * fail (possibly taking the journal offline), we can't risk
2406 * leaving the inode on the orphan list: stray orphan-list
2407 * entries can cause panics at unmount time.
2408 *
2409 * This is safe: on error we're going to ignore the orphan list
2410 * anyway on the next recovery. */
2411 mem_insert:
2412 if (!err)
2413 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2414
2415 jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
2416 jbd_debug(4, "orphan inode %lu will point to %d\n",
2417 inode->i_ino, NEXT_ORPHAN(inode));
2418 out_unlock:
2419 mutex_unlock(&EXT4_SB(sb)->s_orphan_lock);
2420 ext4_std_error(inode->i_sb, err);
2421 return err;
2422 }
2423
2424 /*
2425 * ext4_orphan_del() removes an unlinked or truncated inode from the list
2426 * of such inodes stored on disk, because it is finally being cleaned up.
2427 */
2428 int ext4_orphan_del(handle_t *handle, struct inode *inode)
2429 {
2430 struct list_head *prev;
2431 struct ext4_inode_info *ei = EXT4_I(inode);
2432 struct ext4_sb_info *sbi;
2433 __u32 ino_next;
2434 struct ext4_iloc iloc;
2435 int err = 0;
2436
2437 /* ext4_handle_valid() assumes a valid handle_t pointer */
2438 if (handle && !ext4_handle_valid(handle))
2439 return 0;
2440
2441 mutex_lock(&EXT4_SB(inode->i_sb)->s_orphan_lock);
2442 if (list_empty(&ei->i_orphan))
2443 goto out;
2444
2445 ino_next = NEXT_ORPHAN(inode);
2446 prev = ei->i_orphan.prev;
2447 sbi = EXT4_SB(inode->i_sb);
2448
2449 jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
2450
2451 list_del_init(&ei->i_orphan);
2452
2453 /* If we're on an error path, we may not have a valid
2454 * transaction handle with which to update the orphan list on
2455 * disk, but we still need to remove the inode from the linked
2456 * list in memory. */
2457 if (sbi->s_journal && !handle)
2458 goto out;
2459
2460 err = ext4_reserve_inode_write(handle, inode, &iloc);
2461 if (err)
2462 goto out_err;
2463
2464 if (prev == &sbi->s_orphan) {
2465 jbd_debug(4, "superblock will point to %u\n", ino_next);
2466 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2467 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2468 if (err)
2469 goto out_brelse;
2470 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
2471 err = ext4_handle_dirty_super(handle, inode->i_sb);
2472 } else {
2473 struct ext4_iloc iloc2;
2474 struct inode *i_prev =
2475 &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
2476
2477 jbd_debug(4, "orphan inode %lu will point to %u\n",
2478 i_prev->i_ino, ino_next);
2479 err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
2480 if (err)
2481 goto out_brelse;
2482 NEXT_ORPHAN(i_prev) = ino_next;
2483 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
2484 }
2485 if (err)
2486 goto out_brelse;
2487 NEXT_ORPHAN(inode) = 0;
2488 err = ext4_mark_iloc_dirty(handle, inode, &iloc);
2489
2490 out_err:
2491 ext4_std_error(inode->i_sb, err);
2492 out:
2493 mutex_unlock(&EXT4_SB(inode->i_sb)->s_orphan_lock);
2494 return err;
2495
2496 out_brelse:
2497 brelse(iloc.bh);
2498 goto out_err;
2499 }
2500
2501 static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
2502 {
2503 int retval;
2504 struct inode *inode;
2505 struct buffer_head *bh;
2506 struct ext4_dir_entry_2 *de;
2507 handle_t *handle;
2508
2509 /* Initialize quotas before so that eventual writes go in
2510 * separate transaction */
2511 dquot_initialize(dir);
2512 dquot_initialize(dentry->d_inode);
2513
2514 handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb));
2515 if (IS_ERR(handle))
2516 return PTR_ERR(handle);
2517
2518 retval = -ENOENT;
2519 bh = ext4_find_entry(dir, &dentry->d_name, &de);
2520 if (!bh)
2521 goto end_rmdir;
2522
2523 if (IS_DIRSYNC(dir))
2524 ext4_handle_sync(handle);
2525
2526 inode = dentry->d_inode;
2527
2528 retval = -EIO;
2529 if (le32_to_cpu(de->inode) != inode->i_ino)
2530 goto end_rmdir;
2531
2532 retval = -ENOTEMPTY;
2533 if (!empty_dir(inode))
2534 goto end_rmdir;
2535
2536 retval = ext4_delete_entry(handle, dir, de, bh);
2537 if (retval)
2538 goto end_rmdir;
2539 if (!EXT4_DIR_LINK_EMPTY(inode))
2540 ext4_warning(inode->i_sb,
2541 "empty directory has too many links (%d)",
2542 inode->i_nlink);
2543 inode->i_version++;
2544 clear_nlink(inode);
2545 /* There's no need to set i_disksize: the fact that i_nlink is
2546 * zero will ensure that the right thing happens during any
2547 * recovery. */
2548 inode->i_size = 0;
2549 ext4_orphan_add(handle, inode);
2550 inode->i_ctime = dir->i_ctime = dir->i_mtime = ext4_current_time(inode);
2551 ext4_mark_inode_dirty(handle, inode);
2552 ext4_dec_count(handle, dir);
2553 ext4_update_dx_flag(dir);
2554 ext4_mark_inode_dirty(handle, dir);
2555
2556 end_rmdir:
2557 ext4_journal_stop(handle);
2558 brelse(bh);
2559 return retval;
2560 }
2561
2562 static int ext4_unlink(struct inode *dir, struct dentry *dentry)
2563 {
2564 int retval;
2565 struct inode *inode;
2566 struct buffer_head *bh;
2567 struct ext4_dir_entry_2 *de;
2568 handle_t *handle;
2569
2570 trace_ext4_unlink_enter(dir, dentry);
2571 /* Initialize quotas before so that eventual writes go
2572 * in separate transaction */
2573 dquot_initialize(dir);
2574 dquot_initialize(dentry->d_inode);
2575
2576 handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb));
2577 if (IS_ERR(handle))
2578 return PTR_ERR(handle);
2579
2580 if (IS_DIRSYNC(dir))
2581 ext4_handle_sync(handle);
2582
2583 retval = -ENOENT;
2584 bh = ext4_find_entry(dir, &dentry->d_name, &de);
2585 if (!bh)
2586 goto end_unlink;
2587
2588 inode = dentry->d_inode;
2589
2590 retval = -EIO;
2591 if (le32_to_cpu(de->inode) != inode->i_ino)
2592 goto end_unlink;
2593
2594 if (!inode->i_nlink) {
2595 ext4_warning(inode->i_sb,
2596 "Deleting nonexistent file (%lu), %d",
2597 inode->i_ino, inode->i_nlink);
2598 set_nlink(inode, 1);
2599 }
2600 retval = ext4_delete_entry(handle, dir, de, bh);
2601 if (retval)
2602 goto end_unlink;
2603 dir->i_ctime = dir->i_mtime = ext4_current_time(dir);
2604 ext4_update_dx_flag(dir);
2605 ext4_mark_inode_dirty(handle, dir);
2606 drop_nlink(inode);
2607 if (!inode->i_nlink)
2608 ext4_orphan_add(handle, inode);
2609 inode->i_ctime = ext4_current_time(inode);
2610 ext4_mark_inode_dirty(handle, inode);
2611 retval = 0;
2612
2613 end_unlink:
2614 ext4_journal_stop(handle);
2615 brelse(bh);
2616 trace_ext4_unlink_exit(dentry, retval);
2617 return retval;
2618 }
2619
2620 static int ext4_symlink(struct inode *dir,
2621 struct dentry *dentry, const char *symname)
2622 {
2623 handle_t *handle;
2624 struct inode *inode;
2625 int l, err, retries = 0;
2626 int credits;
2627
2628 l = strlen(symname)+1;
2629 if (l > dir->i_sb->s_blocksize)
2630 return -ENAMETOOLONG;
2631
2632 dquot_initialize(dir);
2633
2634 if (l > EXT4_N_BLOCKS * 4) {
2635 /*
2636 * For non-fast symlinks, we just allocate inode and put it on
2637 * orphan list in the first transaction => we need bitmap,
2638 * group descriptor, sb, inode block, quota blocks, and
2639 * possibly selinux xattr blocks.
2640 */
2641 credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
2642 EXT4_XATTR_TRANS_BLOCKS;
2643 } else {
2644 /*
2645 * Fast symlink. We have to add entry to directory
2646 * (EXT4_DATA_TRANS_BLOCKS + EXT4_INDEX_EXTRA_TRANS_BLOCKS),
2647 * allocate new inode (bitmap, group descriptor, inode block,
2648 * quota blocks, sb is already counted in previous macros).
2649 */
2650 credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2651 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
2652 EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb);
2653 }
2654 retry:
2655 handle = ext4_journal_start(dir, credits);
2656 if (IS_ERR(handle))
2657 return PTR_ERR(handle);
2658
2659 if (IS_DIRSYNC(dir))
2660 ext4_handle_sync(handle);
2661
2662 inode = ext4_new_inode(handle, dir, S_IFLNK|S_IRWXUGO,
2663 &dentry->d_name, 0, NULL);
2664 err = PTR_ERR(inode);
2665 if (IS_ERR(inode))
2666 goto out_stop;
2667
2668 if (l > EXT4_N_BLOCKS * 4) {
2669 inode->i_op = &ext4_symlink_inode_operations;
2670 ext4_set_aops(inode);
2671 /*
2672 * We cannot call page_symlink() with transaction started
2673 * because it calls into ext4_write_begin() which can wait
2674 * for transaction commit if we are running out of space
2675 * and thus we deadlock. So we have to stop transaction now
2676 * and restart it when symlink contents is written.
2677 *
2678 * To keep fs consistent in case of crash, we have to put inode
2679 * to orphan list in the mean time.
2680 */
2681 drop_nlink(inode);
2682 err = ext4_orphan_add(handle, inode);
2683 ext4_journal_stop(handle);
2684 if (err)
2685 goto err_drop_inode;
2686 err = __page_symlink(inode, symname, l, 1);
2687 if (err)
2688 goto err_drop_inode;
2689 /*
2690 * Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS
2691 * + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified
2692 */
2693 handle = ext4_journal_start(dir,
2694 EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2695 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1);
2696 if (IS_ERR(handle)) {
2697 err = PTR_ERR(handle);
2698 goto err_drop_inode;
2699 }
2700 set_nlink(inode, 1);
2701 err = ext4_orphan_del(handle, inode);
2702 if (err) {
2703 ext4_journal_stop(handle);
2704 clear_nlink(inode);
2705 goto err_drop_inode;
2706 }
2707 } else {
2708 /* clear the extent format for fast symlink */
2709 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
2710 inode->i_op = &ext4_fast_symlink_inode_operations;
2711 memcpy((char *)&EXT4_I(inode)->i_data, symname, l);
2712 inode->i_size = l-1;
2713 }
2714 EXT4_I(inode)->i_disksize = inode->i_size;
2715 err = ext4_add_nondir(handle, dentry, inode);
2716 out_stop:
2717 ext4_journal_stop(handle);
2718 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2719 goto retry;
2720 return err;
2721 err_drop_inode:
2722 unlock_new_inode(inode);
2723 iput(inode);
2724 return err;
2725 }
2726
2727 static int ext4_link(struct dentry *old_dentry,
2728 struct inode *dir, struct dentry *dentry)
2729 {
2730 handle_t *handle;
2731 struct inode *inode = old_dentry->d_inode;
2732 int err, retries = 0;
2733
2734 if (inode->i_nlink >= EXT4_LINK_MAX)
2735 return -EMLINK;
2736
2737 dquot_initialize(dir);
2738
2739 retry:
2740 handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2741 EXT4_INDEX_EXTRA_TRANS_BLOCKS);
2742 if (IS_ERR(handle))
2743 return PTR_ERR(handle);
2744
2745 if (IS_DIRSYNC(dir))
2746 ext4_handle_sync(handle);
2747
2748 inode->i_ctime = ext4_current_time(inode);
2749 ext4_inc_count(handle, inode);
2750 ihold(inode);
2751
2752 err = ext4_add_entry(handle, dentry, inode);
2753 if (!err) {
2754 ext4_mark_inode_dirty(handle, inode);
2755 d_instantiate(dentry, inode);
2756 } else {
2757 drop_nlink(inode);
2758 iput(inode);
2759 }
2760 ext4_journal_stop(handle);
2761 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2762 goto retry;
2763 return err;
2764 }
2765
2766 #define PARENT_INO(buffer, size) \
2767 (ext4_next_entry((struct ext4_dir_entry_2 *)(buffer), size)->inode)
2768
2769 /*
2770 * Anybody can rename anything with this: the permission checks are left to the
2771 * higher-level routines.
2772 */
2773 static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
2774 struct inode *new_dir, struct dentry *new_dentry)
2775 {
2776 handle_t *handle;
2777 struct inode *old_inode, *new_inode;
2778 struct buffer_head *old_bh, *new_bh, *dir_bh;
2779 struct ext4_dir_entry_2 *old_de, *new_de;
2780 int retval, force_da_alloc = 0;
2781
2782 dquot_initialize(old_dir);
2783 dquot_initialize(new_dir);
2784
2785 old_bh = new_bh = dir_bh = NULL;
2786
2787 /* Initialize quotas before so that eventual writes go
2788 * in separate transaction */
2789 if (new_dentry->d_inode)
2790 dquot_initialize(new_dentry->d_inode);
2791 handle = ext4_journal_start(old_dir, 2 *
2792 EXT4_DATA_TRANS_BLOCKS(old_dir->i_sb) +
2793 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
2794 if (IS_ERR(handle))
2795 return PTR_ERR(handle);
2796
2797 if (IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir))
2798 ext4_handle_sync(handle);
2799
2800 old_bh = ext4_find_entry(old_dir, &old_dentry->d_name, &old_de);
2801 /*
2802 * Check for inode number is _not_ due to possible IO errors.
2803 * We might rmdir the source, keep it as pwd of some process
2804 * and merrily kill the link to whatever was created under the
2805 * same name. Goodbye sticky bit ;-<
2806 */
2807 old_inode = old_dentry->d_inode;
2808 retval = -ENOENT;
2809 if (!old_bh || le32_to_cpu(old_de->inode) != old_inode->i_ino)
2810 goto end_rename;
2811
2812 new_inode = new_dentry->d_inode;
2813 new_bh = ext4_find_entry(new_dir, &new_dentry->d_name, &new_de);
2814 if (new_bh) {
2815 if (!new_inode) {
2816 brelse(new_bh);
2817 new_bh = NULL;
2818 }
2819 }
2820 if (S_ISDIR(old_inode->i_mode)) {
2821 if (new_inode) {
2822 retval = -ENOTEMPTY;
2823 if (!empty_dir(new_inode))
2824 goto end_rename;
2825 }
2826 retval = -EIO;
2827 dir_bh = ext4_bread(handle, old_inode, 0, 0, &retval);
2828 if (!dir_bh)
2829 goto end_rename;
2830 if (!buffer_verified(dir_bh) &&
2831 !ext4_dirent_csum_verify(old_inode,
2832 (struct ext4_dir_entry *)dir_bh->b_data))
2833 goto end_rename;
2834 set_buffer_verified(dir_bh);
2835 if (le32_to_cpu(PARENT_INO(dir_bh->b_data,
2836 old_dir->i_sb->s_blocksize)) != old_dir->i_ino)
2837 goto end_rename;
2838 retval = -EMLINK;
2839 if (!new_inode && new_dir != old_dir &&
2840 EXT4_DIR_LINK_MAX(new_dir))
2841 goto end_rename;
2842 BUFFER_TRACE(dir_bh, "get_write_access");
2843 retval = ext4_journal_get_write_access(handle, dir_bh);
2844 if (retval)
2845 goto end_rename;
2846 }
2847 if (!new_bh) {
2848 retval = ext4_add_entry(handle, new_dentry, old_inode);
2849 if (retval)
2850 goto end_rename;
2851 } else {
2852 BUFFER_TRACE(new_bh, "get write access");
2853 retval = ext4_journal_get_write_access(handle, new_bh);
2854 if (retval)
2855 goto end_rename;
2856 new_de->inode = cpu_to_le32(old_inode->i_ino);
2857 if (EXT4_HAS_INCOMPAT_FEATURE(new_dir->i_sb,
2858 EXT4_FEATURE_INCOMPAT_FILETYPE))
2859 new_de->file_type = old_de->file_type;
2860 new_dir->i_version++;
2861 new_dir->i_ctime = new_dir->i_mtime =
2862 ext4_current_time(new_dir);
2863 ext4_mark_inode_dirty(handle, new_dir);
2864 BUFFER_TRACE(new_bh, "call ext4_handle_dirty_metadata");
2865 retval = ext4_handle_dirty_dirent_node(handle, new_dir, new_bh);
2866 if (unlikely(retval)) {
2867 ext4_std_error(new_dir->i_sb, retval);
2868 goto end_rename;
2869 }
2870 brelse(new_bh);
2871 new_bh = NULL;
2872 }
2873
2874 /*
2875 * Like most other Unix systems, set the ctime for inodes on a
2876 * rename.
2877 */
2878 old_inode->i_ctime = ext4_current_time(old_inode);
2879 ext4_mark_inode_dirty(handle, old_inode);
2880
2881 /*
2882 * ok, that's it
2883 */
2884 if (le32_to_cpu(old_de->inode) != old_inode->i_ino ||
2885 old_de->name_len != old_dentry->d_name.len ||
2886 strncmp(old_de->name, old_dentry->d_name.name, old_de->name_len) ||
2887 (retval = ext4_delete_entry(handle, old_dir,
2888 old_de, old_bh)) == -ENOENT) {
2889 /* old_de could have moved from under us during htree split, so
2890 * make sure that we are deleting the right entry. We might
2891 * also be pointing to a stale entry in the unused part of
2892 * old_bh so just checking inum and the name isn't enough. */
2893 struct buffer_head *old_bh2;
2894 struct ext4_dir_entry_2 *old_de2;
2895
2896 old_bh2 = ext4_find_entry(old_dir, &old_dentry->d_name, &old_de2);
2897 if (old_bh2) {
2898 retval = ext4_delete_entry(handle, old_dir,
2899 old_de2, old_bh2);
2900 brelse(old_bh2);
2901 }
2902 }
2903 if (retval) {
2904 ext4_warning(old_dir->i_sb,
2905 "Deleting old file (%lu), %d, error=%d",
2906 old_dir->i_ino, old_dir->i_nlink, retval);
2907 }
2908
2909 if (new_inode) {
2910 ext4_dec_count(handle, new_inode);
2911 new_inode->i_ctime = ext4_current_time(new_inode);
2912 }
2913 old_dir->i_ctime = old_dir->i_mtime = ext4_current_time(old_dir);
2914 ext4_update_dx_flag(old_dir);
2915 if (dir_bh) {
2916 PARENT_INO(dir_bh->b_data, new_dir->i_sb->s_blocksize) =
2917 cpu_to_le32(new_dir->i_ino);
2918 BUFFER_TRACE(dir_bh, "call ext4_handle_dirty_metadata");
2919 if (is_dx(old_inode)) {
2920 retval = ext4_handle_dirty_dx_node(handle,
2921 old_inode,
2922 dir_bh);
2923 } else {
2924 retval = ext4_handle_dirty_dirent_node(handle,
2925 old_inode,
2926 dir_bh);
2927 }
2928 if (retval) {
2929 ext4_std_error(old_dir->i_sb, retval);
2930 goto end_rename;
2931 }
2932 ext4_dec_count(handle, old_dir);
2933 if (new_inode) {
2934 /* checked empty_dir above, can't have another parent,
2935 * ext4_dec_count() won't work for many-linked dirs */
2936 clear_nlink(new_inode);
2937 } else {
2938 ext4_inc_count(handle, new_dir);
2939 ext4_update_dx_flag(new_dir);
2940 ext4_mark_inode_dirty(handle, new_dir);
2941 }
2942 }
2943 ext4_mark_inode_dirty(handle, old_dir);
2944 if (new_inode) {
2945 ext4_mark_inode_dirty(handle, new_inode);
2946 if (!new_inode->i_nlink)
2947 ext4_orphan_add(handle, new_inode);
2948 if (!test_opt(new_dir->i_sb, NO_AUTO_DA_ALLOC))
2949 force_da_alloc = 1;
2950 }
2951 retval = 0;
2952
2953 end_rename:
2954 brelse(dir_bh);
2955 brelse(old_bh);
2956 brelse(new_bh);
2957 ext4_journal_stop(handle);
2958 if (retval == 0 && force_da_alloc)
2959 ext4_alloc_da_blocks(old_inode);
2960 return retval;
2961 }
2962
2963 /*
2964 * directories can handle most operations...
2965 */
2966 const struct inode_operations ext4_dir_inode_operations = {
2967 .create = ext4_create,
2968 .lookup = ext4_lookup,
2969 .link = ext4_link,
2970 .unlink = ext4_unlink,
2971 .symlink = ext4_symlink,
2972 .mkdir = ext4_mkdir,
2973 .rmdir = ext4_rmdir,
2974 .mknod = ext4_mknod,
2975 .rename = ext4_rename,
2976 .setattr = ext4_setattr,
2977 #ifdef CONFIG_EXT4_FS_XATTR
2978 .setxattr = generic_setxattr,
2979 .getxattr = generic_getxattr,
2980 .listxattr = ext4_listxattr,
2981 .removexattr = generic_removexattr,
2982 #endif
2983 .get_acl = ext4_get_acl,
2984 .fiemap = ext4_fiemap,
2985 };
2986
2987 const struct inode_operations ext4_special_inode_operations = {
2988 .setattr = ext4_setattr,
2989 #ifdef CONFIG_EXT4_FS_XATTR
2990 .setxattr = generic_setxattr,
2991 .getxattr = generic_getxattr,
2992 .listxattr = ext4_listxattr,
2993 .removexattr = generic_removexattr,
2994 #endif
2995 .get_acl = ext4_get_acl,
2996 };
Linux with added FPC-III support