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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
52static 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
83struct fake_dirent
84{
85 __le32 inode;
86 __le16 rec_len;
87 u8 name_len;
88 u8 file_type;
89};
90
91struct dx_countlimit
92{
93 __le16 limit;
94 __le16 count;
95};
96
97struct 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
109struct 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
127struct dx_node
128{
129 struct fake_dirent fake;
130 struct dx_entry entries[0];
131};
132
133
134struct dx_frame
135{
136 struct buffer_head *bh;
137 struct dx_entry *entries;
138 struct dx_entry *at;
139};
140
141struct 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 */
151struct dx_tail {
152 u32 dt_reserved;
153 __le32 dt_checksum; /* crc32c(uuid+inum+dirblock) */
154};
155
156static inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
157static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
158static inline unsigned dx_get_hash(struct dx_entry *entry);
159static void dx_set_hash(struct dx_entry *entry, unsigned value);
160static unsigned dx_get_count(struct dx_entry *entries);
161static unsigned dx_get_limit(struct dx_entry *entries);
162static void dx_set_count(struct dx_entry *entries, unsigned value);
163static void dx_set_limit(struct dx_entry *entries, unsigned value);
164static unsigned dx_root_limit(struct inode *dir, unsigned infosize);
165static unsigned dx_node_limit(struct inode *dir);
166static 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);
171static void dx_release(struct dx_frame *frames);
172static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize,
173 struct dx_hash_info *hinfo, struct dx_map_entry map[]);
174static void dx_sort_map(struct dx_map_entry *map, unsigned count);
175static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to,
176 struct dx_map_entry *offsets, int count, unsigned blocksize);
177static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize);
178static void dx_insert_block(struct dx_frame *frame,
179 u32 hash, ext4_lblk_t block);
180static int ext4_htree_next_block(struct inode *dir, __u32 hash,
181 struct dx_frame *frame,
182 struct dx_frame *frames,
183 __u32 *start_hash);
184static 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);
188static 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
197static 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 */
207static 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
240static __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
251int 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
273static 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
293static 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
301static 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
329static __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
347static 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
379static 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
407static 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 */
418static inline struct ext4_dir_entry_2 *
419ext4_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
430static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
431{
432 return le32_to_cpu(entry->block) & 0x00ffffff;
433}
434
435static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
436{
437 entry->block = cpu_to_le32(value);
438}
439
440static inline unsigned dx_get_hash(struct dx_entry *entry)
441{
442 return le32_to_cpu(entry->hash);
443}
444
445static inline void dx_set_hash(struct dx_entry *entry, unsigned value)
446{
447 entry->hash = cpu_to_le32(value);
448}
449
450static inline unsigned dx_get_count(struct dx_entry *entries)
451{
452 return le16_to_cpu(((struct dx_countlimit *) entries)->count);
453}
454
455static inline unsigned dx_get_limit(struct dx_entry *entries)
456{
457 return le16_to_cpu(((struct dx_countlimit *) entries)->limit);
458}
459
460static inline void dx_set_count(struct dx_entry *entries, unsigned value)
461{
462 ((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
463}
464
465static inline void dx_set_limit(struct dx_entry *entries, unsigned value)
466{
467 ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
468}
469
470static 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
481static 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
495static 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
506struct stats
507{
508 unsigned names;
509 unsigned space;
510 unsigned bcount;
511};
512
513static 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
543struct 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 */
585static struct dx_frame *
586dx_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 }
723fail2:
724 while (frame >= frame_in) {
725 brelse(frame->bh);
726 frame--;
727 }
728fail:
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
736static 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 */
763static 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 */
835static 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 */
895int 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;
972errout:
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 */
986static 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 */
1011static 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
1037static 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
1051static 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 */
1064static 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 */
1077static 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 */
1126static 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;
1176restart:
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
1249cleanup_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
1256static 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;
1309errout:
1310 dxtrace(printk(KERN_DEBUG "%s not found\n", d_name->name));
1311 dx_release (frames);
1312 return NULL;
1313}
1314
1315static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
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
1351struct 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
1374static 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
1384static 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 */
1395static struct ext4_dir_entry_2 *
1396dx_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 */
1419static 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 */
1445static 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
1546journal_error:
1547 brelse(*bh);
1548 brelse(bh2);
1549 *bh = NULL;
1550 ext4_std_error(dir->i_sb, err);
1551errout:
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 */
1564static 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 */
1648static 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 */
1772static 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 */
1845static 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
1976journal_error:
1977 ext4_std_error(dir->i_sb, err);
1978cleanup:
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 */
1989static 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 */
2045static 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 */
2062static 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
2069static 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 d_instantiate(dentry, inode);
2076 unlock_new_inode(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 */
2093static int ext4_create(struct inode *dir, struct dentry *dentry, umode_t mode,
2094 struct nameidata *nd)
2095{
2096 handle_t *handle;
2097 struct inode *inode;
2098 int err, retries = 0;
2099
2100 dquot_initialize(dir);
2101
2102retry:
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
2126static 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
2138retry:
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#ifdef CONFIG_EXT4_FS_XATTR
2153 inode->i_op = &ext4_special_inode_operations;
2154#endif
2155 err = ext4_add_nondir(handle, dentry, inode);
2156 }
2157 ext4_journal_stop(handle);
2158 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2159 goto retry;
2160 return err;
2161}
2162
2163static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
2164{
2165 handle_t *handle;
2166 struct inode *inode;
2167 struct buffer_head *dir_block = NULL;
2168 struct ext4_dir_entry_2 *de;
2169 struct ext4_dir_entry_tail *t;
2170 unsigned int blocksize = dir->i_sb->s_blocksize;
2171 int csum_size = 0;
2172 int err, retries = 0;
2173
2174 if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
2175 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
2176 csum_size = sizeof(struct ext4_dir_entry_tail);
2177
2178 if (EXT4_DIR_LINK_MAX(dir))
2179 return -EMLINK;
2180
2181 dquot_initialize(dir);
2182
2183retry:
2184 handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2185 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
2186 EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
2187 if (IS_ERR(handle))
2188 return PTR_ERR(handle);
2189
2190 if (IS_DIRSYNC(dir))
2191 ext4_handle_sync(handle);
2192
2193 inode = ext4_new_inode(handle, dir, S_IFDIR | mode,
2194 &dentry->d_name, 0, NULL);
2195 err = PTR_ERR(inode);
2196 if (IS_ERR(inode))
2197 goto out_stop;
2198
2199 inode->i_op = &ext4_dir_inode_operations;
2200 inode->i_fop = &ext4_dir_operations;
2201 inode->i_size = EXT4_I(inode)->i_disksize = inode->i_sb->s_blocksize;
2202 dir_block = ext4_bread(handle, inode, 0, 1, &err);
2203 if (!dir_block)
2204 goto out_clear_inode;
2205 BUFFER_TRACE(dir_block, "get_write_access");
2206 err = ext4_journal_get_write_access(handle, dir_block);
2207 if (err)
2208 goto out_clear_inode;
2209 de = (struct ext4_dir_entry_2 *) dir_block->b_data;
2210 de->inode = cpu_to_le32(inode->i_ino);
2211 de->name_len = 1;
2212 de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
2213 blocksize);
2214 strcpy(de->name, ".");
2215 ext4_set_de_type(dir->i_sb, de, S_IFDIR);
2216 de = ext4_next_entry(de, blocksize);
2217 de->inode = cpu_to_le32(dir->i_ino);
2218 de->rec_len = ext4_rec_len_to_disk(blocksize -
2219 (csum_size + EXT4_DIR_REC_LEN(1)),
2220 blocksize);
2221 de->name_len = 2;
2222 strcpy(de->name, "..");
2223 ext4_set_de_type(dir->i_sb, de, S_IFDIR);
2224 set_nlink(inode, 2);
2225
2226 if (csum_size) {
2227 t = EXT4_DIRENT_TAIL(dir_block->b_data, blocksize);
2228 initialize_dirent_tail(t, blocksize);
2229 }
2230
2231 BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
2232 err = ext4_handle_dirty_dirent_node(handle, inode, dir_block);
2233 if (err)
2234 goto out_clear_inode;
2235 set_buffer_verified(dir_block);
2236 err = ext4_mark_inode_dirty(handle, inode);
2237 if (!err)
2238 err = ext4_add_entry(handle, dentry, inode);
2239 if (err) {
2240out_clear_inode:
2241 clear_nlink(inode);
2242 unlock_new_inode(inode);
2243 ext4_mark_inode_dirty(handle, inode);
2244 iput(inode);
2245 goto out_stop;
2246 }
2247 ext4_inc_count(handle, dir);
2248 ext4_update_dx_flag(dir);
2249 err = ext4_mark_inode_dirty(handle, dir);
2250 if (err)
2251 goto out_clear_inode;
2252 d_instantiate(dentry, inode);
2253 unlock_new_inode(inode);
2254out_stop:
2255 brelse(dir_block);
2256 ext4_journal_stop(handle);
2257 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2258 goto retry;
2259 return err;
2260}
2261
2262/*
2263 * routine to check that the specified directory is empty (for rmdir)
2264 */
2265static int empty_dir(struct inode *inode)
2266{
2267 unsigned int offset;
2268 struct buffer_head *bh;
2269 struct ext4_dir_entry_2 *de, *de1;
2270 struct super_block *sb;
2271 int err = 0;
2272
2273 sb = inode->i_sb;
2274 if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2) ||
2275 !(bh = ext4_bread(NULL, inode, 0, 0, &err))) {
2276 if (err)
2277 EXT4_ERROR_INODE(inode,
2278 "error %d reading directory lblock 0", err);
2279 else
2280 ext4_warning(inode->i_sb,
2281 "bad directory (dir #%lu) - no data block",
2282 inode->i_ino);
2283 return 1;
2284 }
2285 if (!buffer_verified(bh) &&
2286 !ext4_dirent_csum_verify(inode,
2287 (struct ext4_dir_entry *)bh->b_data)) {
2288 EXT4_ERROR_INODE(inode, "checksum error reading directory "
2289 "lblock 0");
2290 return -EIO;
2291 }
2292 set_buffer_verified(bh);
2293 de = (struct ext4_dir_entry_2 *) bh->b_data;
2294 de1 = ext4_next_entry(de, sb->s_blocksize);
2295 if (le32_to_cpu(de->inode) != inode->i_ino ||
2296 !le32_to_cpu(de1->inode) ||
2297 strcmp(".", de->name) ||
2298 strcmp("..", de1->name)) {
2299 ext4_warning(inode->i_sb,
2300 "bad directory (dir #%lu) - no `.' or `..'",
2301 inode->i_ino);
2302 brelse(bh);
2303 return 1;
2304 }
2305 offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) +
2306 ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize);
2307 de = ext4_next_entry(de1, sb->s_blocksize);
2308 while (offset < inode->i_size) {
2309 if (!bh ||
2310 (void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
2311 unsigned int lblock;
2312 err = 0;
2313 brelse(bh);
2314 lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb);
2315 bh = ext4_bread(NULL, inode, lblock, 0, &err);
2316 if (!bh) {
2317 if (err)
2318 EXT4_ERROR_INODE(inode,
2319 "error %d reading directory "
2320 "lblock %u", err, lblock);
2321 offset += sb->s_blocksize;
2322 continue;
2323 }
2324 if (!buffer_verified(bh) &&
2325 !ext4_dirent_csum_verify(inode,
2326 (struct ext4_dir_entry *)bh->b_data)) {
2327 EXT4_ERROR_INODE(inode, "checksum error "
2328 "reading directory lblock 0");
2329 return -EIO;
2330 }
2331 set_buffer_verified(bh);
2332 de = (struct ext4_dir_entry_2 *) bh->b_data;
2333 }
2334 if (ext4_check_dir_entry(inode, NULL, de, bh, offset)) {
2335 de = (struct ext4_dir_entry_2 *)(bh->b_data +
2336 sb->s_blocksize);
2337 offset = (offset | (sb->s_blocksize - 1)) + 1;
2338 continue;
2339 }
2340 if (le32_to_cpu(de->inode)) {
2341 brelse(bh);
2342 return 0;
2343 }
2344 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
2345 de = ext4_next_entry(de, sb->s_blocksize);
2346 }
2347 brelse(bh);
2348 return 1;
2349}
2350
2351/* ext4_orphan_add() links an unlinked or truncated inode into a list of
2352 * such inodes, starting at the superblock, in case we crash before the
2353 * file is closed/deleted, or in case the inode truncate spans multiple
2354 * transactions and the last transaction is not recovered after a crash.
2355 *
2356 * At filesystem recovery time, we walk this list deleting unlinked
2357 * inodes and truncating linked inodes in ext4_orphan_cleanup().
2358 */
2359int ext4_orphan_add(handle_t *handle, struct inode *inode)
2360{
2361 struct super_block *sb = inode->i_sb;
2362 struct ext4_iloc iloc;
2363 int err = 0, rc;
2364
2365 if (!ext4_handle_valid(handle))
2366 return 0;
2367
2368 mutex_lock(&EXT4_SB(sb)->s_orphan_lock);
2369 if (!list_empty(&EXT4_I(inode)->i_orphan))
2370 goto out_unlock;
2371
2372 /*
2373 * Orphan handling is only valid for files with data blocks
2374 * being truncated, or files being unlinked. Note that we either
2375 * hold i_mutex, or the inode can not be referenced from outside,
2376 * so i_nlink should not be bumped due to race
2377 */
2378 J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2379 S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
2380
2381 BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access");
2382 err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
2383 if (err)
2384 goto out_unlock;
2385
2386 err = ext4_reserve_inode_write(handle, inode, &iloc);
2387 if (err)
2388 goto out_unlock;
2389 /*
2390 * Due to previous errors inode may be already a part of on-disk
2391 * orphan list. If so skip on-disk list modification.
2392 */
2393 if (NEXT_ORPHAN(inode) && NEXT_ORPHAN(inode) <=
2394 (le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count)))
2395 goto mem_insert;
2396
2397 /* Insert this inode at the head of the on-disk orphan list... */
2398 NEXT_ORPHAN(inode) = le32_to_cpu(EXT4_SB(sb)->s_es->s_last_orphan);
2399 EXT4_SB(sb)->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
2400 err = ext4_handle_dirty_super_now(handle, sb);
2401 rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
2402 if (!err)
2403 err = rc;
2404
2405 /* Only add to the head of the in-memory list if all the
2406 * previous operations succeeded. If the orphan_add is going to
2407 * fail (possibly taking the journal offline), we can't risk
2408 * leaving the inode on the orphan list: stray orphan-list
2409 * entries can cause panics at unmount time.
2410 *
2411 * This is safe: on error we're going to ignore the orphan list
2412 * anyway on the next recovery. */
2413mem_insert:
2414 if (!err)
2415 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2416
2417 jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
2418 jbd_debug(4, "orphan inode %lu will point to %d\n",
2419 inode->i_ino, NEXT_ORPHAN(inode));
2420out_unlock:
2421 mutex_unlock(&EXT4_SB(sb)->s_orphan_lock);
2422 ext4_std_error(inode->i_sb, err);
2423 return err;
2424}
2425
2426/*
2427 * ext4_orphan_del() removes an unlinked or truncated inode from the list
2428 * of such inodes stored on disk, because it is finally being cleaned up.
2429 */
2430int ext4_orphan_del(handle_t *handle, struct inode *inode)
2431{
2432 struct list_head *prev;
2433 struct ext4_inode_info *ei = EXT4_I(inode);
2434 struct ext4_sb_info *sbi;
2435 __u32 ino_next;
2436 struct ext4_iloc iloc;
2437 int err = 0;
2438
2439 /* ext4_handle_valid() assumes a valid handle_t pointer */
2440 if (handle && !ext4_handle_valid(handle))
2441 return 0;
2442
2443 mutex_lock(&EXT4_SB(inode->i_sb)->s_orphan_lock);
2444 if (list_empty(&ei->i_orphan))
2445 goto out;
2446
2447 ino_next = NEXT_ORPHAN(inode);
2448 prev = ei->i_orphan.prev;
2449 sbi = EXT4_SB(inode->i_sb);
2450
2451 jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
2452
2453 list_del_init(&ei->i_orphan);
2454
2455 /* If we're on an error path, we may not have a valid
2456 * transaction handle with which to update the orphan list on
2457 * disk, but we still need to remove the inode from the linked
2458 * list in memory. */
2459 if (sbi->s_journal && !handle)
2460 goto out;
2461
2462 err = ext4_reserve_inode_write(handle, inode, &iloc);
2463 if (err)
2464 goto out_err;
2465
2466 if (prev == &sbi->s_orphan) {
2467 jbd_debug(4, "superblock will point to %u\n", ino_next);
2468 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2469 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2470 if (err)
2471 goto out_brelse;
2472 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
2473 err = ext4_handle_dirty_super_now(handle, inode->i_sb);
2474 } else {
2475 struct ext4_iloc iloc2;
2476 struct inode *i_prev =
2477 &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
2478
2479 jbd_debug(4, "orphan inode %lu will point to %u\n",
2480 i_prev->i_ino, ino_next);
2481 err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
2482 if (err)
2483 goto out_brelse;
2484 NEXT_ORPHAN(i_prev) = ino_next;
2485 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
2486 }
2487 if (err)
2488 goto out_brelse;
2489 NEXT_ORPHAN(inode) = 0;
2490 err = ext4_mark_iloc_dirty(handle, inode, &iloc);
2491
2492out_err:
2493 ext4_std_error(inode->i_sb, err);
2494out:
2495 mutex_unlock(&EXT4_SB(inode->i_sb)->s_orphan_lock);
2496 return err;
2497
2498out_brelse:
2499 brelse(iloc.bh);
2500 goto out_err;
2501}
2502
2503static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
2504{
2505 int retval;
2506 struct inode *inode;
2507 struct buffer_head *bh;
2508 struct ext4_dir_entry_2 *de;
2509 handle_t *handle;
2510
2511 /* Initialize quotas before so that eventual writes go in
2512 * separate transaction */
2513 dquot_initialize(dir);
2514 dquot_initialize(dentry->d_inode);
2515
2516 handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb));
2517 if (IS_ERR(handle))
2518 return PTR_ERR(handle);
2519
2520 retval = -ENOENT;
2521 bh = ext4_find_entry(dir, &dentry->d_name, &de);
2522 if (!bh)
2523 goto end_rmdir;
2524
2525 if (IS_DIRSYNC(dir))
2526 ext4_handle_sync(handle);
2527
2528 inode = dentry->d_inode;
2529
2530 retval = -EIO;
2531 if (le32_to_cpu(de->inode) != inode->i_ino)
2532 goto end_rmdir;
2533
2534 retval = -ENOTEMPTY;
2535 if (!empty_dir(inode))
2536 goto end_rmdir;
2537
2538 retval = ext4_delete_entry(handle, dir, de, bh);
2539 if (retval)
2540 goto end_rmdir;
2541 if (!EXT4_DIR_LINK_EMPTY(inode))
2542 ext4_warning(inode->i_sb,
2543 "empty directory has too many links (%d)",
2544 inode->i_nlink);
2545 inode->i_version++;
2546 clear_nlink(inode);
2547 /* There's no need to set i_disksize: the fact that i_nlink is
2548 * zero will ensure that the right thing happens during any
2549 * recovery. */
2550 inode->i_size = 0;
2551 ext4_orphan_add(handle, inode);
2552 inode->i_ctime = dir->i_ctime = dir->i_mtime = ext4_current_time(inode);
2553 ext4_mark_inode_dirty(handle, inode);
2554 ext4_dec_count(handle, dir);
2555 ext4_update_dx_flag(dir);
2556 ext4_mark_inode_dirty(handle, dir);
2557
2558end_rmdir:
2559 ext4_journal_stop(handle);
2560 brelse(bh);
2561 return retval;
2562}
2563
2564static int ext4_unlink(struct inode *dir, struct dentry *dentry)
2565{
2566 int retval;
2567 struct inode *inode;
2568 struct buffer_head *bh;
2569 struct ext4_dir_entry_2 *de;
2570 handle_t *handle;
2571
2572 trace_ext4_unlink_enter(dir, dentry);
2573 /* Initialize quotas before so that eventual writes go
2574 * in separate transaction */
2575 dquot_initialize(dir);
2576 dquot_initialize(dentry->d_inode);
2577
2578 handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb));
2579 if (IS_ERR(handle))
2580 return PTR_ERR(handle);
2581
2582 if (IS_DIRSYNC(dir))
2583 ext4_handle_sync(handle);
2584
2585 retval = -ENOENT;
2586 bh = ext4_find_entry(dir, &dentry->d_name, &de);
2587 if (!bh)
2588 goto end_unlink;
2589
2590 inode = dentry->d_inode;
2591
2592 retval = -EIO;
2593 if (le32_to_cpu(de->inode) != inode->i_ino)
2594 goto end_unlink;
2595
2596 if (!inode->i_nlink) {
2597 ext4_warning(inode->i_sb,
2598 "Deleting nonexistent file (%lu), %d",
2599 inode->i_ino, inode->i_nlink);
2600 set_nlink(inode, 1);
2601 }
2602 retval = ext4_delete_entry(handle, dir, de, bh);
2603 if (retval)
2604 goto end_unlink;
2605 dir->i_ctime = dir->i_mtime = ext4_current_time(dir);
2606 ext4_update_dx_flag(dir);
2607 ext4_mark_inode_dirty(handle, dir);
2608 drop_nlink(inode);
2609 if (!inode->i_nlink)
2610 ext4_orphan_add(handle, inode);
2611 inode->i_ctime = ext4_current_time(inode);
2612 ext4_mark_inode_dirty(handle, inode);
2613 retval = 0;
2614
2615end_unlink:
2616 ext4_journal_stop(handle);
2617 brelse(bh);
2618 trace_ext4_unlink_exit(dentry, retval);
2619 return retval;
2620}
2621
2622static int ext4_symlink(struct inode *dir,
2623 struct dentry *dentry, const char *symname)
2624{
2625 handle_t *handle;
2626 struct inode *inode;
2627 int l, err, retries = 0;
2628 int credits;
2629
2630 l = strlen(symname)+1;
2631 if (l > dir->i_sb->s_blocksize)
2632 return -ENAMETOOLONG;
2633
2634 dquot_initialize(dir);
2635
2636 if (l > EXT4_N_BLOCKS * 4) {
2637 /*
2638 * For non-fast symlinks, we just allocate inode and put it on
2639 * orphan list in the first transaction => we need bitmap,
2640 * group descriptor, sb, inode block, quota blocks, and
2641 * possibly selinux xattr blocks.
2642 */
2643 credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
2644 EXT4_XATTR_TRANS_BLOCKS;
2645 } else {
2646 /*
2647 * Fast symlink. We have to add entry to directory
2648 * (EXT4_DATA_TRANS_BLOCKS + EXT4_INDEX_EXTRA_TRANS_BLOCKS),
2649 * allocate new inode (bitmap, group descriptor, inode block,
2650 * quota blocks, sb is already counted in previous macros).
2651 */
2652 credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2653 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
2654 EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb);
2655 }
2656retry:
2657 handle = ext4_journal_start(dir, credits);
2658 if (IS_ERR(handle))
2659 return PTR_ERR(handle);
2660
2661 if (IS_DIRSYNC(dir))
2662 ext4_handle_sync(handle);
2663
2664 inode = ext4_new_inode(handle, dir, S_IFLNK|S_IRWXUGO,
2665 &dentry->d_name, 0, NULL);
2666 err = PTR_ERR(inode);
2667 if (IS_ERR(inode))
2668 goto out_stop;
2669
2670 if (l > EXT4_N_BLOCKS * 4) {
2671 inode->i_op = &ext4_symlink_inode_operations;
2672 ext4_set_aops(inode);
2673 /*
2674 * We cannot call page_symlink() with transaction started
2675 * because it calls into ext4_write_begin() which can wait
2676 * for transaction commit if we are running out of space
2677 * and thus we deadlock. So we have to stop transaction now
2678 * and restart it when symlink contents is written.
2679 *
2680 * To keep fs consistent in case of crash, we have to put inode
2681 * to orphan list in the mean time.
2682 */
2683 drop_nlink(inode);
2684 err = ext4_orphan_add(handle, inode);
2685 ext4_journal_stop(handle);
2686 if (err)
2687 goto err_drop_inode;
2688 err = __page_symlink(inode, symname, l, 1);
2689 if (err)
2690 goto err_drop_inode;
2691 /*
2692 * Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS
2693 * + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified
2694 */
2695 handle = ext4_journal_start(dir,
2696 EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2697 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1);
2698 if (IS_ERR(handle)) {
2699 err = PTR_ERR(handle);
2700 goto err_drop_inode;
2701 }
2702 set_nlink(inode, 1);
2703 err = ext4_orphan_del(handle, inode);
2704 if (err) {
2705 ext4_journal_stop(handle);
2706 clear_nlink(inode);
2707 goto err_drop_inode;
2708 }
2709 } else {
2710 /* clear the extent format for fast symlink */
2711 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
2712 inode->i_op = &ext4_fast_symlink_inode_operations;
2713 memcpy((char *)&EXT4_I(inode)->i_data, symname, l);
2714 inode->i_size = l-1;
2715 }
2716 EXT4_I(inode)->i_disksize = inode->i_size;
2717 err = ext4_add_nondir(handle, dentry, inode);
2718out_stop:
2719 ext4_journal_stop(handle);
2720 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2721 goto retry;
2722 return err;
2723err_drop_inode:
2724 unlock_new_inode(inode);
2725 iput(inode);
2726 return err;
2727}
2728
2729static int ext4_link(struct dentry *old_dentry,
2730 struct inode *dir, struct dentry *dentry)
2731{
2732 handle_t *handle;
2733 struct inode *inode = old_dentry->d_inode;
2734 int err, retries = 0;
2735
2736 if (inode->i_nlink >= EXT4_LINK_MAX)
2737 return -EMLINK;
2738
2739 dquot_initialize(dir);
2740
2741retry:
2742 handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2743 EXT4_INDEX_EXTRA_TRANS_BLOCKS);
2744 if (IS_ERR(handle))
2745 return PTR_ERR(handle);
2746
2747 if (IS_DIRSYNC(dir))
2748 ext4_handle_sync(handle);
2749
2750 inode->i_ctime = ext4_current_time(inode);
2751 ext4_inc_count(handle, inode);
2752 ihold(inode);
2753
2754 err = ext4_add_entry(handle, dentry, inode);
2755 if (!err) {
2756 ext4_mark_inode_dirty(handle, inode);
2757 d_instantiate(dentry, inode);
2758 } else {
2759 drop_nlink(inode);
2760 iput(inode);
2761 }
2762 ext4_journal_stop(handle);
2763 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2764 goto retry;
2765 return err;
2766}
2767
2768#define PARENT_INO(buffer, size) \
2769 (ext4_next_entry((struct ext4_dir_entry_2 *)(buffer), size)->inode)
2770
2771/*
2772 * Anybody can rename anything with this: the permission checks are left to the
2773 * higher-level routines.
2774 */
2775static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
2776 struct inode *new_dir, struct dentry *new_dentry)
2777{
2778 handle_t *handle;
2779 struct inode *old_inode, *new_inode;
2780 struct buffer_head *old_bh, *new_bh, *dir_bh;
2781 struct ext4_dir_entry_2 *old_de, *new_de;
2782 int retval, force_da_alloc = 0;
2783
2784 dquot_initialize(old_dir);
2785 dquot_initialize(new_dir);
2786
2787 old_bh = new_bh = dir_bh = NULL;
2788
2789 /* Initialize quotas before so that eventual writes go
2790 * in separate transaction */
2791 if (new_dentry->d_inode)
2792 dquot_initialize(new_dentry->d_inode);
2793 handle = ext4_journal_start(old_dir, 2 *
2794 EXT4_DATA_TRANS_BLOCKS(old_dir->i_sb) +
2795 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
2796 if (IS_ERR(handle))
2797 return PTR_ERR(handle);
2798
2799 if (IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir))
2800 ext4_handle_sync(handle);
2801
2802 old_bh = ext4_find_entry(old_dir, &old_dentry->d_name, &old_de);
2803 /*
2804 * Check for inode number is _not_ due to possible IO errors.
2805 * We might rmdir the source, keep it as pwd of some process
2806 * and merrily kill the link to whatever was created under the
2807 * same name. Goodbye sticky bit ;-<
2808 */
2809 old_inode = old_dentry->d_inode;
2810 retval = -ENOENT;
2811 if (!old_bh || le32_to_cpu(old_de->inode) != old_inode->i_ino)
2812 goto end_rename;
2813
2814 new_inode = new_dentry->d_inode;
2815 new_bh = ext4_find_entry(new_dir, &new_dentry->d_name, &new_de);
2816 if (new_bh) {
2817 if (!new_inode) {
2818 brelse(new_bh);
2819 new_bh = NULL;
2820 }
2821 }
2822 if (S_ISDIR(old_inode->i_mode)) {
2823 if (new_inode) {
2824 retval = -ENOTEMPTY;
2825 if (!empty_dir(new_inode))
2826 goto end_rename;
2827 }
2828 retval = -EIO;
2829 dir_bh = ext4_bread(handle, old_inode, 0, 0, &retval);
2830 if (!dir_bh)
2831 goto end_rename;
2832 if (!buffer_verified(dir_bh) &&
2833 !ext4_dirent_csum_verify(old_inode,
2834 (struct ext4_dir_entry *)dir_bh->b_data))
2835 goto end_rename;
2836 set_buffer_verified(dir_bh);
2837 if (le32_to_cpu(PARENT_INO(dir_bh->b_data,
2838 old_dir->i_sb->s_blocksize)) != old_dir->i_ino)
2839 goto end_rename;
2840 retval = -EMLINK;
2841 if (!new_inode && new_dir != old_dir &&
2842 EXT4_DIR_LINK_MAX(new_dir))
2843 goto end_rename;
2844 BUFFER_TRACE(dir_bh, "get_write_access");
2845 retval = ext4_journal_get_write_access(handle, dir_bh);
2846 if (retval)
2847 goto end_rename;
2848 }
2849 if (!new_bh) {
2850 retval = ext4_add_entry(handle, new_dentry, old_inode);
2851 if (retval)
2852 goto end_rename;
2853 } else {
2854 BUFFER_TRACE(new_bh, "get write access");
2855 retval = ext4_journal_get_write_access(handle, new_bh);
2856 if (retval)
2857 goto end_rename;
2858 new_de->inode = cpu_to_le32(old_inode->i_ino);
2859 if (EXT4_HAS_INCOMPAT_FEATURE(new_dir->i_sb,
2860 EXT4_FEATURE_INCOMPAT_FILETYPE))
2861 new_de->file_type = old_de->file_type;
2862 new_dir->i_version++;
2863 new_dir->i_ctime = new_dir->i_mtime =
2864 ext4_current_time(new_dir);
2865 ext4_mark_inode_dirty(handle, new_dir);
2866 BUFFER_TRACE(new_bh, "call ext4_handle_dirty_metadata");
2867 retval = ext4_handle_dirty_dirent_node(handle, new_dir, new_bh);
2868 if (unlikely(retval)) {
2869 ext4_std_error(new_dir->i_sb, retval);
2870 goto end_rename;
2871 }
2872 brelse(new_bh);
2873 new_bh = NULL;
2874 }
2875
2876 /*
2877 * Like most other Unix systems, set the ctime for inodes on a
2878 * rename.
2879 */
2880 old_inode->i_ctime = ext4_current_time(old_inode);
2881 ext4_mark_inode_dirty(handle, old_inode);
2882
2883 /*
2884 * ok, that's it
2885 */
2886 if (le32_to_cpu(old_de->inode) != old_inode->i_ino ||
2887 old_de->name_len != old_dentry->d_name.len ||
2888 strncmp(old_de->name, old_dentry->d_name.name, old_de->name_len) ||
2889 (retval = ext4_delete_entry(handle, old_dir,
2890 old_de, old_bh)) == -ENOENT) {
2891 /* old_de could have moved from under us during htree split, so
2892 * make sure that we are deleting the right entry. We might
2893 * also be pointing to a stale entry in the unused part of
2894 * old_bh so just checking inum and the name isn't enough. */
2895 struct buffer_head *old_bh2;
2896 struct ext4_dir_entry_2 *old_de2;
2897
2898 old_bh2 = ext4_find_entry(old_dir, &old_dentry->d_name, &old_de2);
2899 if (old_bh2) {
2900 retval = ext4_delete_entry(handle, old_dir,
2901 old_de2, old_bh2);
2902 brelse(old_bh2);
2903 }
2904 }
2905 if (retval) {
2906 ext4_warning(old_dir->i_sb,
2907 "Deleting old file (%lu), %d, error=%d",
2908 old_dir->i_ino, old_dir->i_nlink, retval);
2909 }
2910
2911 if (new_inode) {
2912 ext4_dec_count(handle, new_inode);
2913 new_inode->i_ctime = ext4_current_time(new_inode);
2914 }
2915 old_dir->i_ctime = old_dir->i_mtime = ext4_current_time(old_dir);
2916 ext4_update_dx_flag(old_dir);
2917 if (dir_bh) {
2918 PARENT_INO(dir_bh->b_data, new_dir->i_sb->s_blocksize) =
2919 cpu_to_le32(new_dir->i_ino);
2920 BUFFER_TRACE(dir_bh, "call ext4_handle_dirty_metadata");
2921 if (is_dx(old_inode)) {
2922 retval = ext4_handle_dirty_dx_node(handle,
2923 old_inode,
2924 dir_bh);
2925 } else {
2926 retval = ext4_handle_dirty_dirent_node(handle,
2927 old_inode,
2928 dir_bh);
2929 }
2930 if (retval) {
2931 ext4_std_error(old_dir->i_sb, retval);
2932 goto end_rename;
2933 }
2934 ext4_dec_count(handle, old_dir);
2935 if (new_inode) {
2936 /* checked empty_dir above, can't have another parent,
2937 * ext4_dec_count() won't work for many-linked dirs */
2938 clear_nlink(new_inode);
2939 } else {
2940 ext4_inc_count(handle, new_dir);
2941 ext4_update_dx_flag(new_dir);
2942 ext4_mark_inode_dirty(handle, new_dir);
2943 }
2944 }
2945 ext4_mark_inode_dirty(handle, old_dir);
2946 if (new_inode) {
2947 ext4_mark_inode_dirty(handle, new_inode);
2948 if (!new_inode->i_nlink)
2949 ext4_orphan_add(handle, new_inode);
2950 if (!test_opt(new_dir->i_sb, NO_AUTO_DA_ALLOC))
2951 force_da_alloc = 1;
2952 }
2953 retval = 0;
2954
2955end_rename:
2956 brelse(dir_bh);
2957 brelse(old_bh);
2958 brelse(new_bh);
2959 ext4_journal_stop(handle);
2960 if (retval == 0 && force_da_alloc)
2961 ext4_alloc_da_blocks(old_inode);
2962 return retval;
2963}
2964
2965/*
2966 * directories can handle most operations...
2967 */
2968const struct inode_operations ext4_dir_inode_operations = {
2969 .create = ext4_create,
2970 .lookup = ext4_lookup,
2971 .link = ext4_link,
2972 .unlink = ext4_unlink,
2973 .symlink = ext4_symlink,
2974 .mkdir = ext4_mkdir,
2975 .rmdir = ext4_rmdir,
2976 .mknod = ext4_mknod,
2977 .rename = ext4_rename,
2978 .setattr = ext4_setattr,
2979#ifdef CONFIG_EXT4_FS_XATTR
2980 .setxattr = generic_setxattr,
2981 .getxattr = generic_getxattr,
2982 .listxattr = ext4_listxattr,
2983 .removexattr = generic_removexattr,
2984#endif
2985 .get_acl = ext4_get_acl,
2986 .fiemap = ext4_fiemap,
2987};
2988
2989const struct inode_operations ext4_special_inode_operations = {
2990 .setattr = ext4_setattr,
2991#ifdef CONFIG_EXT4_FS_XATTR
2992 .setxattr = generic_setxattr,
2993 .getxattr = generic_getxattr,
2994 .listxattr = ext4_listxattr,
2995 .removexattr = generic_removexattr,
2996#endif
2997 .get_acl = ext4_get_acl,
2998};
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
52static 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
83struct fake_dirent
84{
85 __le32 inode;
86 __le16 rec_len;
87 u8 name_len;
88 u8 file_type;
89};
90
91struct dx_countlimit
92{
93 __le16 limit;
94 __le16 count;
95};
96
97struct 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
109struct 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
127struct dx_node
128{
129 struct fake_dirent fake;
130 struct dx_entry entries[0];
131};
132
133
134struct dx_frame
135{
136 struct buffer_head *bh;
137 struct dx_entry *entries;
138 struct dx_entry *at;
139};
140
141struct dx_map_entry
142{
143 u32 hash;
144 u16 offs;
145 u16 size;
146};
147
148static inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
149static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
150static inline unsigned dx_get_hash(struct dx_entry *entry);
151static void dx_set_hash(struct dx_entry *entry, unsigned value);
152static unsigned dx_get_count(struct dx_entry *entries);
153static unsigned dx_get_limit(struct dx_entry *entries);
154static void dx_set_count(struct dx_entry *entries, unsigned value);
155static void dx_set_limit(struct dx_entry *entries, unsigned value);
156static unsigned dx_root_limit(struct inode *dir, unsigned infosize);
157static unsigned dx_node_limit(struct inode *dir);
158static struct dx_frame *dx_probe(const struct qstr *d_name,
159 struct inode *dir,
160 struct dx_hash_info *hinfo,
161 struct dx_frame *frame,
162 int *err);
163static void dx_release(struct dx_frame *frames);
164static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize,
165 struct dx_hash_info *hinfo, struct dx_map_entry map[]);
166static void dx_sort_map(struct dx_map_entry *map, unsigned count);
167static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to,
168 struct dx_map_entry *offsets, int count, unsigned blocksize);
169static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize);
170static void dx_insert_block(struct dx_frame *frame,
171 u32 hash, ext4_lblk_t block);
172static int ext4_htree_next_block(struct inode *dir, __u32 hash,
173 struct dx_frame *frame,
174 struct dx_frame *frames,
175 __u32 *start_hash);
176static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
177 const struct qstr *d_name,
178 struct ext4_dir_entry_2 **res_dir,
179 int *err);
180static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
181 struct inode *inode);
182
183/*
184 * p is at least 6 bytes before the end of page
185 */
186static inline struct ext4_dir_entry_2 *
187ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
188{
189 return (struct ext4_dir_entry_2 *)((char *)p +
190 ext4_rec_len_from_disk(p->rec_len, blocksize));
191}
192
193/*
194 * Future: use high four bits of block for coalesce-on-delete flags
195 * Mask them off for now.
196 */
197
198static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
199{
200 return le32_to_cpu(entry->block) & 0x00ffffff;
201}
202
203static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
204{
205 entry->block = cpu_to_le32(value);
206}
207
208static inline unsigned dx_get_hash(struct dx_entry *entry)
209{
210 return le32_to_cpu(entry->hash);
211}
212
213static inline void dx_set_hash(struct dx_entry *entry, unsigned value)
214{
215 entry->hash = cpu_to_le32(value);
216}
217
218static inline unsigned dx_get_count(struct dx_entry *entries)
219{
220 return le16_to_cpu(((struct dx_countlimit *) entries)->count);
221}
222
223static inline unsigned dx_get_limit(struct dx_entry *entries)
224{
225 return le16_to_cpu(((struct dx_countlimit *) entries)->limit);
226}
227
228static inline void dx_set_count(struct dx_entry *entries, unsigned value)
229{
230 ((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
231}
232
233static inline void dx_set_limit(struct dx_entry *entries, unsigned value)
234{
235 ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
236}
237
238static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
239{
240 unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
241 EXT4_DIR_REC_LEN(2) - infosize;
242 return entry_space / sizeof(struct dx_entry);
243}
244
245static inline unsigned dx_node_limit(struct inode *dir)
246{
247 unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);
248 return entry_space / sizeof(struct dx_entry);
249}
250
251/*
252 * Debug
253 */
254#ifdef DX_DEBUG
255static void dx_show_index(char * label, struct dx_entry *entries)
256{
257 int i, n = dx_get_count (entries);
258 printk(KERN_DEBUG "%s index ", label);
259 for (i = 0; i < n; i++) {
260 printk("%x->%lu ", i ? dx_get_hash(entries + i) :
261 0, (unsigned long)dx_get_block(entries + i));
262 }
263 printk("\n");
264}
265
266struct stats
267{
268 unsigned names;
269 unsigned space;
270 unsigned bcount;
271};
272
273static struct stats dx_show_leaf(struct dx_hash_info *hinfo, struct ext4_dir_entry_2 *de,
274 int size, int show_names)
275{
276 unsigned names = 0, space = 0;
277 char *base = (char *) de;
278 struct dx_hash_info h = *hinfo;
279
280 printk("names: ");
281 while ((char *) de < base + size)
282 {
283 if (de->inode)
284 {
285 if (show_names)
286 {
287 int len = de->name_len;
288 char *name = de->name;
289 while (len--) printk("%c", *name++);
290 ext4fs_dirhash(de->name, de->name_len, &h);
291 printk(":%x.%u ", h.hash,
292 (unsigned) ((char *) de - base));
293 }
294 space += EXT4_DIR_REC_LEN(de->name_len);
295 names++;
296 }
297 de = ext4_next_entry(de, size);
298 }
299 printk("(%i)\n", names);
300 return (struct stats) { names, space, 1 };
301}
302
303struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
304 struct dx_entry *entries, int levels)
305{
306 unsigned blocksize = dir->i_sb->s_blocksize;
307 unsigned count = dx_get_count(entries), names = 0, space = 0, i;
308 unsigned bcount = 0;
309 struct buffer_head *bh;
310 int err;
311 printk("%i indexed blocks...\n", count);
312 for (i = 0; i < count; i++, entries++)
313 {
314 ext4_lblk_t block = dx_get_block(entries);
315 ext4_lblk_t hash = i ? dx_get_hash(entries): 0;
316 u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
317 struct stats stats;
318 printk("%s%3u:%03u hash %8x/%8x ",levels?"":" ", i, block, hash, range);
319 if (!(bh = ext4_bread (NULL,dir, block, 0,&err))) continue;
320 stats = levels?
321 dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
322 dx_show_leaf(hinfo, (struct ext4_dir_entry_2 *) bh->b_data, blocksize, 0);
323 names += stats.names;
324 space += stats.space;
325 bcount += stats.bcount;
326 brelse(bh);
327 }
328 if (bcount)
329 printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n",
330 levels ? "" : " ", names, space/bcount,
331 (space/bcount)*100/blocksize);
332 return (struct stats) { names, space, bcount};
333}
334#endif /* DX_DEBUG */
335
336/*
337 * Probe for a directory leaf block to search.
338 *
339 * dx_probe can return ERR_BAD_DX_DIR, which means there was a format
340 * error in the directory index, and the caller should fall back to
341 * searching the directory normally. The callers of dx_probe **MUST**
342 * check for this error code, and make sure it never gets reflected
343 * back to userspace.
344 */
345static struct dx_frame *
346dx_probe(const struct qstr *d_name, struct inode *dir,
347 struct dx_hash_info *hinfo, struct dx_frame *frame_in, int *err)
348{
349 unsigned count, indirect;
350 struct dx_entry *at, *entries, *p, *q, *m;
351 struct dx_root *root;
352 struct buffer_head *bh;
353 struct dx_frame *frame = frame_in;
354 u32 hash;
355
356 frame->bh = NULL;
357 if (!(bh = ext4_bread (NULL,dir, 0, 0, err)))
358 goto fail;
359 root = (struct dx_root *) bh->b_data;
360 if (root->info.hash_version != DX_HASH_TEA &&
361 root->info.hash_version != DX_HASH_HALF_MD4 &&
362 root->info.hash_version != DX_HASH_LEGACY) {
363 ext4_warning(dir->i_sb, "Unrecognised inode hash code %d",
364 root->info.hash_version);
365 brelse(bh);
366 *err = ERR_BAD_DX_DIR;
367 goto fail;
368 }
369 hinfo->hash_version = root->info.hash_version;
370 if (hinfo->hash_version <= DX_HASH_TEA)
371 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
372 hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
373 if (d_name)
374 ext4fs_dirhash(d_name->name, d_name->len, hinfo);
375 hash = hinfo->hash;
376
377 if (root->info.unused_flags & 1) {
378 ext4_warning(dir->i_sb, "Unimplemented inode hash flags: %#06x",
379 root->info.unused_flags);
380 brelse(bh);
381 *err = ERR_BAD_DX_DIR;
382 goto fail;
383 }
384
385 if ((indirect = root->info.indirect_levels) > 1) {
386 ext4_warning(dir->i_sb, "Unimplemented inode hash depth: %#06x",
387 root->info.indirect_levels);
388 brelse(bh);
389 *err = ERR_BAD_DX_DIR;
390 goto fail;
391 }
392
393 entries = (struct dx_entry *) (((char *)&root->info) +
394 root->info.info_length);
395
396 if (dx_get_limit(entries) != dx_root_limit(dir,
397 root->info.info_length)) {
398 ext4_warning(dir->i_sb, "dx entry: limit != root limit");
399 brelse(bh);
400 *err = ERR_BAD_DX_DIR;
401 goto fail;
402 }
403
404 dxtrace(printk("Look up %x", hash));
405 while (1)
406 {
407 count = dx_get_count(entries);
408 if (!count || count > dx_get_limit(entries)) {
409 ext4_warning(dir->i_sb,
410 "dx entry: no count or count > limit");
411 brelse(bh);
412 *err = ERR_BAD_DX_DIR;
413 goto fail2;
414 }
415
416 p = entries + 1;
417 q = entries + count - 1;
418 while (p <= q)
419 {
420 m = p + (q - p)/2;
421 dxtrace(printk("."));
422 if (dx_get_hash(m) > hash)
423 q = m - 1;
424 else
425 p = m + 1;
426 }
427
428 if (0) // linear search cross check
429 {
430 unsigned n = count - 1;
431 at = entries;
432 while (n--)
433 {
434 dxtrace(printk(","));
435 if (dx_get_hash(++at) > hash)
436 {
437 at--;
438 break;
439 }
440 }
441 assert (at == p - 1);
442 }
443
444 at = p - 1;
445 dxtrace(printk(" %x->%u\n", at == entries? 0: dx_get_hash(at), dx_get_block(at)));
446 frame->bh = bh;
447 frame->entries = entries;
448 frame->at = at;
449 if (!indirect--) return frame;
450 if (!(bh = ext4_bread (NULL,dir, dx_get_block(at), 0, err)))
451 goto fail2;
452 at = entries = ((struct dx_node *) bh->b_data)->entries;
453 if (dx_get_limit(entries) != dx_node_limit (dir)) {
454 ext4_warning(dir->i_sb,
455 "dx entry: limit != node limit");
456 brelse(bh);
457 *err = ERR_BAD_DX_DIR;
458 goto fail2;
459 }
460 frame++;
461 frame->bh = NULL;
462 }
463fail2:
464 while (frame >= frame_in) {
465 brelse(frame->bh);
466 frame--;
467 }
468fail:
469 if (*err == ERR_BAD_DX_DIR)
470 ext4_warning(dir->i_sb,
471 "Corrupt dir inode %ld, running e2fsck is "
472 "recommended.", dir->i_ino);
473 return NULL;
474}
475
476static void dx_release (struct dx_frame *frames)
477{
478 if (frames[0].bh == NULL)
479 return;
480
481 if (((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels)
482 brelse(frames[1].bh);
483 brelse(frames[0].bh);
484}
485
486/*
487 * This function increments the frame pointer to search the next leaf
488 * block, and reads in the necessary intervening nodes if the search
489 * should be necessary. Whether or not the search is necessary is
490 * controlled by the hash parameter. If the hash value is even, then
491 * the search is only continued if the next block starts with that
492 * hash value. This is used if we are searching for a specific file.
493 *
494 * If the hash value is HASH_NB_ALWAYS, then always go to the next block.
495 *
496 * This function returns 1 if the caller should continue to search,
497 * or 0 if it should not. If there is an error reading one of the
498 * index blocks, it will a negative error code.
499 *
500 * If start_hash is non-null, it will be filled in with the starting
501 * hash of the next page.
502 */
503static int ext4_htree_next_block(struct inode *dir, __u32 hash,
504 struct dx_frame *frame,
505 struct dx_frame *frames,
506 __u32 *start_hash)
507{
508 struct dx_frame *p;
509 struct buffer_head *bh;
510 int err, num_frames = 0;
511 __u32 bhash;
512
513 p = frame;
514 /*
515 * Find the next leaf page by incrementing the frame pointer.
516 * If we run out of entries in the interior node, loop around and
517 * increment pointer in the parent node. When we break out of
518 * this loop, num_frames indicates the number of interior
519 * nodes need to be read.
520 */
521 while (1) {
522 if (++(p->at) < p->entries + dx_get_count(p->entries))
523 break;
524 if (p == frames)
525 return 0;
526 num_frames++;
527 p--;
528 }
529
530 /*
531 * If the hash is 1, then continue only if the next page has a
532 * continuation hash of any value. This is used for readdir
533 * handling. Otherwise, check to see if the hash matches the
534 * desired contiuation hash. If it doesn't, return since
535 * there's no point to read in the successive index pages.
536 */
537 bhash = dx_get_hash(p->at);
538 if (start_hash)
539 *start_hash = bhash;
540 if ((hash & 1) == 0) {
541 if ((bhash & ~1) != hash)
542 return 0;
543 }
544 /*
545 * If the hash is HASH_NB_ALWAYS, we always go to the next
546 * block so no check is necessary
547 */
548 while (num_frames--) {
549 if (!(bh = ext4_bread(NULL, dir, dx_get_block(p->at),
550 0, &err)))
551 return err; /* Failure */
552 p++;
553 brelse(p->bh);
554 p->bh = bh;
555 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
556 }
557 return 1;
558}
559
560
561/*
562 * This function fills a red-black tree with information from a
563 * directory block. It returns the number directory entries loaded
564 * into the tree. If there is an error it is returned in err.
565 */
566static int htree_dirblock_to_tree(struct file *dir_file,
567 struct inode *dir, ext4_lblk_t block,
568 struct dx_hash_info *hinfo,
569 __u32 start_hash, __u32 start_minor_hash)
570{
571 struct buffer_head *bh;
572 struct ext4_dir_entry_2 *de, *top;
573 int err, count = 0;
574
575 dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
576 (unsigned long)block));
577 if (!(bh = ext4_bread (NULL, dir, block, 0, &err)))
578 return err;
579
580 de = (struct ext4_dir_entry_2 *) bh->b_data;
581 top = (struct ext4_dir_entry_2 *) ((char *) de +
582 dir->i_sb->s_blocksize -
583 EXT4_DIR_REC_LEN(0));
584 for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) {
585 if (ext4_check_dir_entry(dir, NULL, de, bh,
586 (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
587 + ((char *)de - bh->b_data))) {
588 /* On error, skip the f_pos to the next block. */
589 dir_file->f_pos = (dir_file->f_pos |
590 (dir->i_sb->s_blocksize - 1)) + 1;
591 brelse(bh);
592 return count;
593 }
594 ext4fs_dirhash(de->name, de->name_len, hinfo);
595 if ((hinfo->hash < start_hash) ||
596 ((hinfo->hash == start_hash) &&
597 (hinfo->minor_hash < start_minor_hash)))
598 continue;
599 if (de->inode == 0)
600 continue;
601 if ((err = ext4_htree_store_dirent(dir_file,
602 hinfo->hash, hinfo->minor_hash, de)) != 0) {
603 brelse(bh);
604 return err;
605 }
606 count++;
607 }
608 brelse(bh);
609 return count;
610}
611
612
613/*
614 * This function fills a red-black tree with information from a
615 * directory. We start scanning the directory in hash order, starting
616 * at start_hash and start_minor_hash.
617 *
618 * This function returns the number of entries inserted into the tree,
619 * or a negative error code.
620 */
621int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
622 __u32 start_minor_hash, __u32 *next_hash)
623{
624 struct dx_hash_info hinfo;
625 struct ext4_dir_entry_2 *de;
626 struct dx_frame frames[2], *frame;
627 struct inode *dir;
628 ext4_lblk_t block;
629 int count = 0;
630 int ret, err;
631 __u32 hashval;
632
633 dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
634 start_hash, start_minor_hash));
635 dir = dir_file->f_path.dentry->d_inode;
636 if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) {
637 hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
638 if (hinfo.hash_version <= DX_HASH_TEA)
639 hinfo.hash_version +=
640 EXT4_SB(dir->i_sb)->s_hash_unsigned;
641 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
642 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
643 start_hash, start_minor_hash);
644 *next_hash = ~0;
645 return count;
646 }
647 hinfo.hash = start_hash;
648 hinfo.minor_hash = 0;
649 frame = dx_probe(NULL, dir, &hinfo, frames, &err);
650 if (!frame)
651 return err;
652
653 /* Add '.' and '..' from the htree header */
654 if (!start_hash && !start_minor_hash) {
655 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
656 if ((err = ext4_htree_store_dirent(dir_file, 0, 0, de)) != 0)
657 goto errout;
658 count++;
659 }
660 if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
661 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
662 de = ext4_next_entry(de, dir->i_sb->s_blocksize);
663 if ((err = ext4_htree_store_dirent(dir_file, 2, 0, de)) != 0)
664 goto errout;
665 count++;
666 }
667
668 while (1) {
669 block = dx_get_block(frame->at);
670 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
671 start_hash, start_minor_hash);
672 if (ret < 0) {
673 err = ret;
674 goto errout;
675 }
676 count += ret;
677 hashval = ~0;
678 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
679 frame, frames, &hashval);
680 *next_hash = hashval;
681 if (ret < 0) {
682 err = ret;
683 goto errout;
684 }
685 /*
686 * Stop if: (a) there are no more entries, or
687 * (b) we have inserted at least one entry and the
688 * next hash value is not a continuation
689 */
690 if ((ret == 0) ||
691 (count && ((hashval & 1) == 0)))
692 break;
693 }
694 dx_release(frames);
695 dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, "
696 "next hash: %x\n", count, *next_hash));
697 return count;
698errout:
699 dx_release(frames);
700 return (err);
701}
702
703
704/*
705 * Directory block splitting, compacting
706 */
707
708/*
709 * Create map of hash values, offsets, and sizes, stored at end of block.
710 * Returns number of entries mapped.
711 */
712static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize,
713 struct dx_hash_info *hinfo,
714 struct dx_map_entry *map_tail)
715{
716 int count = 0;
717 char *base = (char *) de;
718 struct dx_hash_info h = *hinfo;
719
720 while ((char *) de < base + blocksize) {
721 if (de->name_len && de->inode) {
722 ext4fs_dirhash(de->name, de->name_len, &h);
723 map_tail--;
724 map_tail->hash = h.hash;
725 map_tail->offs = ((char *) de - base)>>2;
726 map_tail->size = le16_to_cpu(de->rec_len);
727 count++;
728 cond_resched();
729 }
730 /* XXX: do we need to check rec_len == 0 case? -Chris */
731 de = ext4_next_entry(de, blocksize);
732 }
733 return count;
734}
735
736/* Sort map by hash value */
737static void dx_sort_map (struct dx_map_entry *map, unsigned count)
738{
739 struct dx_map_entry *p, *q, *top = map + count - 1;
740 int more;
741 /* Combsort until bubble sort doesn't suck */
742 while (count > 2) {
743 count = count*10/13;
744 if (count - 9 < 2) /* 9, 10 -> 11 */
745 count = 11;
746 for (p = top, q = p - count; q >= map; p--, q--)
747 if (p->hash < q->hash)
748 swap(*p, *q);
749 }
750 /* Garden variety bubble sort */
751 do {
752 more = 0;
753 q = top;
754 while (q-- > map) {
755 if (q[1].hash >= q[0].hash)
756 continue;
757 swap(*(q+1), *q);
758 more = 1;
759 }
760 } while(more);
761}
762
763static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
764{
765 struct dx_entry *entries = frame->entries;
766 struct dx_entry *old = frame->at, *new = old + 1;
767 int count = dx_get_count(entries);
768
769 assert(count < dx_get_limit(entries));
770 assert(old < entries + count);
771 memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
772 dx_set_hash(new, hash);
773 dx_set_block(new, block);
774 dx_set_count(entries, count + 1);
775}
776
777static void ext4_update_dx_flag(struct inode *inode)
778{
779 if (!EXT4_HAS_COMPAT_FEATURE(inode->i_sb,
780 EXT4_FEATURE_COMPAT_DIR_INDEX))
781 ext4_clear_inode_flag(inode, EXT4_INODE_INDEX);
782}
783
784/*
785 * NOTE! unlike strncmp, ext4_match returns 1 for success, 0 for failure.
786 *
787 * `len <= EXT4_NAME_LEN' is guaranteed by caller.
788 * `de != NULL' is guaranteed by caller.
789 */
790static inline int ext4_match (int len, const char * const name,
791 struct ext4_dir_entry_2 * de)
792{
793 if (len != de->name_len)
794 return 0;
795 if (!de->inode)
796 return 0;
797 return !memcmp(name, de->name, len);
798}
799
800/*
801 * Returns 0 if not found, -1 on failure, and 1 on success
802 */
803static inline int search_dirblock(struct buffer_head *bh,
804 struct inode *dir,
805 const struct qstr *d_name,
806 unsigned int offset,
807 struct ext4_dir_entry_2 ** res_dir)
808{
809 struct ext4_dir_entry_2 * de;
810 char * dlimit;
811 int de_len;
812 const char *name = d_name->name;
813 int namelen = d_name->len;
814
815 de = (struct ext4_dir_entry_2 *) bh->b_data;
816 dlimit = bh->b_data + dir->i_sb->s_blocksize;
817 while ((char *) de < dlimit) {
818 /* this code is executed quadratically often */
819 /* do minimal checking `by hand' */
820
821 if ((char *) de + namelen <= dlimit &&
822 ext4_match (namelen, name, de)) {
823 /* found a match - just to be sure, do a full check */
824 if (ext4_check_dir_entry(dir, NULL, de, bh, offset))
825 return -1;
826 *res_dir = de;
827 return 1;
828 }
829 /* prevent looping on a bad block */
830 de_len = ext4_rec_len_from_disk(de->rec_len,
831 dir->i_sb->s_blocksize);
832 if (de_len <= 0)
833 return -1;
834 offset += de_len;
835 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
836 }
837 return 0;
838}
839
840
841/*
842 * ext4_find_entry()
843 *
844 * finds an entry in the specified directory with the wanted name. It
845 * returns the cache buffer in which the entry was found, and the entry
846 * itself (as a parameter - res_dir). It does NOT read the inode of the
847 * entry - you'll have to do that yourself if you want to.
848 *
849 * The returned buffer_head has ->b_count elevated. The caller is expected
850 * to brelse() it when appropriate.
851 */
852static struct buffer_head * ext4_find_entry (struct inode *dir,
853 const struct qstr *d_name,
854 struct ext4_dir_entry_2 ** res_dir)
855{
856 struct super_block *sb;
857 struct buffer_head *bh_use[NAMEI_RA_SIZE];
858 struct buffer_head *bh, *ret = NULL;
859 ext4_lblk_t start, block, b;
860 const u8 *name = d_name->name;
861 int ra_max = 0; /* Number of bh's in the readahead
862 buffer, bh_use[] */
863 int ra_ptr = 0; /* Current index into readahead
864 buffer */
865 int num = 0;
866 ext4_lblk_t nblocks;
867 int i, err;
868 int namelen;
869
870 *res_dir = NULL;
871 sb = dir->i_sb;
872 namelen = d_name->len;
873 if (namelen > EXT4_NAME_LEN)
874 return NULL;
875 if ((namelen <= 2) && (name[0] == '.') &&
876 (name[1] == '.' || name[1] == '\0')) {
877 /*
878 * "." or ".." will only be in the first block
879 * NFS may look up ".."; "." should be handled by the VFS
880 */
881 block = start = 0;
882 nblocks = 1;
883 goto restart;
884 }
885 if (is_dx(dir)) {
886 bh = ext4_dx_find_entry(dir, d_name, res_dir, &err);
887 /*
888 * On success, or if the error was file not found,
889 * return. Otherwise, fall back to doing a search the
890 * old fashioned way.
891 */
892 if (bh || (err != ERR_BAD_DX_DIR))
893 return bh;
894 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
895 "falling back\n"));
896 }
897 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
898 start = EXT4_I(dir)->i_dir_start_lookup;
899 if (start >= nblocks)
900 start = 0;
901 block = start;
902restart:
903 do {
904 /*
905 * We deal with the read-ahead logic here.
906 */
907 if (ra_ptr >= ra_max) {
908 /* Refill the readahead buffer */
909 ra_ptr = 0;
910 b = block;
911 for (ra_max = 0; ra_max < NAMEI_RA_SIZE; ra_max++) {
912 /*
913 * Terminate if we reach the end of the
914 * directory and must wrap, or if our
915 * search has finished at this block.
916 */
917 if (b >= nblocks || (num && block == start)) {
918 bh_use[ra_max] = NULL;
919 break;
920 }
921 num++;
922 bh = ext4_getblk(NULL, dir, b++, 0, &err);
923 bh_use[ra_max] = bh;
924 if (bh)
925 ll_rw_block(READ | REQ_META | REQ_PRIO,
926 1, &bh);
927 }
928 }
929 if ((bh = bh_use[ra_ptr++]) == NULL)
930 goto next;
931 wait_on_buffer(bh);
932 if (!buffer_uptodate(bh)) {
933 /* read error, skip block & hope for the best */
934 EXT4_ERROR_INODE(dir, "reading directory lblock %lu",
935 (unsigned long) block);
936 brelse(bh);
937 goto next;
938 }
939 i = search_dirblock(bh, dir, d_name,
940 block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
941 if (i == 1) {
942 EXT4_I(dir)->i_dir_start_lookup = block;
943 ret = bh;
944 goto cleanup_and_exit;
945 } else {
946 brelse(bh);
947 if (i < 0)
948 goto cleanup_and_exit;
949 }
950 next:
951 if (++block >= nblocks)
952 block = 0;
953 } while (block != start);
954
955 /*
956 * If the directory has grown while we were searching, then
957 * search the last part of the directory before giving up.
958 */
959 block = nblocks;
960 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
961 if (block < nblocks) {
962 start = 0;
963 goto restart;
964 }
965
966cleanup_and_exit:
967 /* Clean up the read-ahead blocks */
968 for (; ra_ptr < ra_max; ra_ptr++)
969 brelse(bh_use[ra_ptr]);
970 return ret;
971}
972
973static struct buffer_head * ext4_dx_find_entry(struct inode *dir, const struct qstr *d_name,
974 struct ext4_dir_entry_2 **res_dir, int *err)
975{
976 struct super_block * sb = dir->i_sb;
977 struct dx_hash_info hinfo;
978 struct dx_frame frames[2], *frame;
979 struct buffer_head *bh;
980 ext4_lblk_t block;
981 int retval;
982
983 if (!(frame = dx_probe(d_name, dir, &hinfo, frames, err)))
984 return NULL;
985 do {
986 block = dx_get_block(frame->at);
987 if (!(bh = ext4_bread(NULL, dir, block, 0, err)))
988 goto errout;
989
990 retval = search_dirblock(bh, dir, d_name,
991 block << EXT4_BLOCK_SIZE_BITS(sb),
992 res_dir);
993 if (retval == 1) { /* Success! */
994 dx_release(frames);
995 return bh;
996 }
997 brelse(bh);
998 if (retval == -1) {
999 *err = ERR_BAD_DX_DIR;
1000 goto errout;
1001 }
1002
1003 /* Check to see if we should continue to search */
1004 retval = ext4_htree_next_block(dir, hinfo.hash, frame,
1005 frames, NULL);
1006 if (retval < 0) {
1007 ext4_warning(sb,
1008 "error reading index page in directory #%lu",
1009 dir->i_ino);
1010 *err = retval;
1011 goto errout;
1012 }
1013 } while (retval == 1);
1014
1015 *err = -ENOENT;
1016errout:
1017 dxtrace(printk(KERN_DEBUG "%s not found\n", d_name->name));
1018 dx_release (frames);
1019 return NULL;
1020}
1021
1022static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
1023{
1024 struct inode *inode;
1025 struct ext4_dir_entry_2 *de;
1026 struct buffer_head *bh;
1027
1028 if (dentry->d_name.len > EXT4_NAME_LEN)
1029 return ERR_PTR(-ENAMETOOLONG);
1030
1031 bh = ext4_find_entry(dir, &dentry->d_name, &de);
1032 inode = NULL;
1033 if (bh) {
1034 __u32 ino = le32_to_cpu(de->inode);
1035 brelse(bh);
1036 if (!ext4_valid_inum(dir->i_sb, ino)) {
1037 EXT4_ERROR_INODE(dir, "bad inode number: %u", ino);
1038 return ERR_PTR(-EIO);
1039 }
1040 inode = ext4_iget(dir->i_sb, ino);
1041 if (inode == ERR_PTR(-ESTALE)) {
1042 EXT4_ERROR_INODE(dir,
1043 "deleted inode referenced: %u",
1044 ino);
1045 return ERR_PTR(-EIO);
1046 }
1047 }
1048 return d_splice_alias(inode, dentry);
1049}
1050
1051
1052struct dentry *ext4_get_parent(struct dentry *child)
1053{
1054 __u32 ino;
1055 static const struct qstr dotdot = {
1056 .name = "..",
1057 .len = 2,
1058 };
1059 struct ext4_dir_entry_2 * de;
1060 struct buffer_head *bh;
1061
1062 bh = ext4_find_entry(child->d_inode, &dotdot, &de);
1063 if (!bh)
1064 return ERR_PTR(-ENOENT);
1065 ino = le32_to_cpu(de->inode);
1066 brelse(bh);
1067
1068 if (!ext4_valid_inum(child->d_inode->i_sb, ino)) {
1069 EXT4_ERROR_INODE(child->d_inode,
1070 "bad parent inode number: %u", ino);
1071 return ERR_PTR(-EIO);
1072 }
1073
1074 return d_obtain_alias(ext4_iget(child->d_inode->i_sb, ino));
1075}
1076
1077#define S_SHIFT 12
1078static unsigned char ext4_type_by_mode[S_IFMT >> S_SHIFT] = {
1079 [S_IFREG >> S_SHIFT] = EXT4_FT_REG_FILE,
1080 [S_IFDIR >> S_SHIFT] = EXT4_FT_DIR,
1081 [S_IFCHR >> S_SHIFT] = EXT4_FT_CHRDEV,
1082 [S_IFBLK >> S_SHIFT] = EXT4_FT_BLKDEV,
1083 [S_IFIFO >> S_SHIFT] = EXT4_FT_FIFO,
1084 [S_IFSOCK >> S_SHIFT] = EXT4_FT_SOCK,
1085 [S_IFLNK >> S_SHIFT] = EXT4_FT_SYMLINK,
1086};
1087
1088static inline void ext4_set_de_type(struct super_block *sb,
1089 struct ext4_dir_entry_2 *de,
1090 umode_t mode) {
1091 if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE))
1092 de->file_type = ext4_type_by_mode[(mode & S_IFMT)>>S_SHIFT];
1093}
1094
1095/*
1096 * Move count entries from end of map between two memory locations.
1097 * Returns pointer to last entry moved.
1098 */
1099static struct ext4_dir_entry_2 *
1100dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count,
1101 unsigned blocksize)
1102{
1103 unsigned rec_len = 0;
1104
1105 while (count--) {
1106 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
1107 (from + (map->offs<<2));
1108 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1109 memcpy (to, de, rec_len);
1110 ((struct ext4_dir_entry_2 *) to)->rec_len =
1111 ext4_rec_len_to_disk(rec_len, blocksize);
1112 de->inode = 0;
1113 map++;
1114 to += rec_len;
1115 }
1116 return (struct ext4_dir_entry_2 *) (to - rec_len);
1117}
1118
1119/*
1120 * Compact each dir entry in the range to the minimal rec_len.
1121 * Returns pointer to last entry in range.
1122 */
1123static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize)
1124{
1125 struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
1126 unsigned rec_len = 0;
1127
1128 prev = to = de;
1129 while ((char*)de < base + blocksize) {
1130 next = ext4_next_entry(de, blocksize);
1131 if (de->inode && de->name_len) {
1132 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1133 if (de > to)
1134 memmove(to, de, rec_len);
1135 to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
1136 prev = to;
1137 to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
1138 }
1139 de = next;
1140 }
1141 return prev;
1142}
1143
1144/*
1145 * Split a full leaf block to make room for a new dir entry.
1146 * Allocate a new block, and move entries so that they are approx. equally full.
1147 * Returns pointer to de in block into which the new entry will be inserted.
1148 */
1149static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
1150 struct buffer_head **bh,struct dx_frame *frame,
1151 struct dx_hash_info *hinfo, int *error)
1152{
1153 unsigned blocksize = dir->i_sb->s_blocksize;
1154 unsigned count, continued;
1155 struct buffer_head *bh2;
1156 ext4_lblk_t newblock;
1157 u32 hash2;
1158 struct dx_map_entry *map;
1159 char *data1 = (*bh)->b_data, *data2;
1160 unsigned split, move, size;
1161 struct ext4_dir_entry_2 *de = NULL, *de2;
1162 int err = 0, i;
1163
1164 bh2 = ext4_append (handle, dir, &newblock, &err);
1165 if (!(bh2)) {
1166 brelse(*bh);
1167 *bh = NULL;
1168 goto errout;
1169 }
1170
1171 BUFFER_TRACE(*bh, "get_write_access");
1172 err = ext4_journal_get_write_access(handle, *bh);
1173 if (err)
1174 goto journal_error;
1175
1176 BUFFER_TRACE(frame->bh, "get_write_access");
1177 err = ext4_journal_get_write_access(handle, frame->bh);
1178 if (err)
1179 goto journal_error;
1180
1181 data2 = bh2->b_data;
1182
1183 /* create map in the end of data2 block */
1184 map = (struct dx_map_entry *) (data2 + blocksize);
1185 count = dx_make_map((struct ext4_dir_entry_2 *) data1,
1186 blocksize, hinfo, map);
1187 map -= count;
1188 dx_sort_map(map, count);
1189 /* Split the existing block in the middle, size-wise */
1190 size = 0;
1191 move = 0;
1192 for (i = count-1; i >= 0; i--) {
1193 /* is more than half of this entry in 2nd half of the block? */
1194 if (size + map[i].size/2 > blocksize/2)
1195 break;
1196 size += map[i].size;
1197 move++;
1198 }
1199 /* map index at which we will split */
1200 split = count - move;
1201 hash2 = map[split].hash;
1202 continued = hash2 == map[split - 1].hash;
1203 dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
1204 (unsigned long)dx_get_block(frame->at),
1205 hash2, split, count-split));
1206
1207 /* Fancy dance to stay within two buffers */
1208 de2 = dx_move_dirents(data1, data2, map + split, count - split, blocksize);
1209 de = dx_pack_dirents(data1, blocksize);
1210 de->rec_len = ext4_rec_len_to_disk(data1 + blocksize - (char *) de,
1211 blocksize);
1212 de2->rec_len = ext4_rec_len_to_disk(data2 + blocksize - (char *) de2,
1213 blocksize);
1214 dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data1, blocksize, 1));
1215 dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data2, blocksize, 1));
1216
1217 /* Which block gets the new entry? */
1218 if (hinfo->hash >= hash2)
1219 {
1220 swap(*bh, bh2);
1221 de = de2;
1222 }
1223 dx_insert_block(frame, hash2 + continued, newblock);
1224 err = ext4_handle_dirty_metadata(handle, dir, bh2);
1225 if (err)
1226 goto journal_error;
1227 err = ext4_handle_dirty_metadata(handle, dir, frame->bh);
1228 if (err)
1229 goto journal_error;
1230 brelse(bh2);
1231 dxtrace(dx_show_index("frame", frame->entries));
1232 return de;
1233
1234journal_error:
1235 brelse(*bh);
1236 brelse(bh2);
1237 *bh = NULL;
1238 ext4_std_error(dir->i_sb, err);
1239errout:
1240 *error = err;
1241 return NULL;
1242}
1243
1244/*
1245 * Add a new entry into a directory (leaf) block. If de is non-NULL,
1246 * it points to a directory entry which is guaranteed to be large
1247 * enough for new directory entry. If de is NULL, then
1248 * add_dirent_to_buf will attempt search the directory block for
1249 * space. It will return -ENOSPC if no space is available, and -EIO
1250 * and -EEXIST if directory entry already exists.
1251 */
1252static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
1253 struct inode *inode, struct ext4_dir_entry_2 *de,
1254 struct buffer_head *bh)
1255{
1256 struct inode *dir = dentry->d_parent->d_inode;
1257 const char *name = dentry->d_name.name;
1258 int namelen = dentry->d_name.len;
1259 unsigned int offset = 0;
1260 unsigned int blocksize = dir->i_sb->s_blocksize;
1261 unsigned short reclen;
1262 int nlen, rlen, err;
1263 char *top;
1264
1265 reclen = EXT4_DIR_REC_LEN(namelen);
1266 if (!de) {
1267 de = (struct ext4_dir_entry_2 *)bh->b_data;
1268 top = bh->b_data + blocksize - reclen;
1269 while ((char *) de <= top) {
1270 if (ext4_check_dir_entry(dir, NULL, de, bh, offset))
1271 return -EIO;
1272 if (ext4_match(namelen, name, de))
1273 return -EEXIST;
1274 nlen = EXT4_DIR_REC_LEN(de->name_len);
1275 rlen = ext4_rec_len_from_disk(de->rec_len, blocksize);
1276 if ((de->inode? rlen - nlen: rlen) >= reclen)
1277 break;
1278 de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
1279 offset += rlen;
1280 }
1281 if ((char *) de > top)
1282 return -ENOSPC;
1283 }
1284 BUFFER_TRACE(bh, "get_write_access");
1285 err = ext4_journal_get_write_access(handle, bh);
1286 if (err) {
1287 ext4_std_error(dir->i_sb, err);
1288 return err;
1289 }
1290
1291 /* By now the buffer is marked for journaling */
1292 nlen = EXT4_DIR_REC_LEN(de->name_len);
1293 rlen = ext4_rec_len_from_disk(de->rec_len, blocksize);
1294 if (de->inode) {
1295 struct ext4_dir_entry_2 *de1 = (struct ext4_dir_entry_2 *)((char *)de + nlen);
1296 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, blocksize);
1297 de->rec_len = ext4_rec_len_to_disk(nlen, blocksize);
1298 de = de1;
1299 }
1300 de->file_type = EXT4_FT_UNKNOWN;
1301 if (inode) {
1302 de->inode = cpu_to_le32(inode->i_ino);
1303 ext4_set_de_type(dir->i_sb, de, inode->i_mode);
1304 } else
1305 de->inode = 0;
1306 de->name_len = namelen;
1307 memcpy(de->name, name, namelen);
1308 /*
1309 * XXX shouldn't update any times until successful
1310 * completion of syscall, but too many callers depend
1311 * on this.
1312 *
1313 * XXX similarly, too many callers depend on
1314 * ext4_new_inode() setting the times, but error
1315 * recovery deletes the inode, so the worst that can
1316 * happen is that the times are slightly out of date
1317 * and/or different from the directory change time.
1318 */
1319 dir->i_mtime = dir->i_ctime = ext4_current_time(dir);
1320 ext4_update_dx_flag(dir);
1321 dir->i_version++;
1322 ext4_mark_inode_dirty(handle, dir);
1323 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1324 err = ext4_handle_dirty_metadata(handle, dir, bh);
1325 if (err)
1326 ext4_std_error(dir->i_sb, err);
1327 return 0;
1328}
1329
1330/*
1331 * This converts a one block unindexed directory to a 3 block indexed
1332 * directory, and adds the dentry to the indexed directory.
1333 */
1334static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
1335 struct inode *inode, struct buffer_head *bh)
1336{
1337 struct inode *dir = dentry->d_parent->d_inode;
1338 const char *name = dentry->d_name.name;
1339 int namelen = dentry->d_name.len;
1340 struct buffer_head *bh2;
1341 struct dx_root *root;
1342 struct dx_frame frames[2], *frame;
1343 struct dx_entry *entries;
1344 struct ext4_dir_entry_2 *de, *de2;
1345 char *data1, *top;
1346 unsigned len;
1347 int retval;
1348 unsigned blocksize;
1349 struct dx_hash_info hinfo;
1350 ext4_lblk_t block;
1351 struct fake_dirent *fde;
1352
1353 blocksize = dir->i_sb->s_blocksize;
1354 dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
1355 retval = ext4_journal_get_write_access(handle, bh);
1356 if (retval) {
1357 ext4_std_error(dir->i_sb, retval);
1358 brelse(bh);
1359 return retval;
1360 }
1361 root = (struct dx_root *) bh->b_data;
1362
1363 /* The 0th block becomes the root, move the dirents out */
1364 fde = &root->dotdot;
1365 de = (struct ext4_dir_entry_2 *)((char *)fde +
1366 ext4_rec_len_from_disk(fde->rec_len, blocksize));
1367 if ((char *) de >= (((char *) root) + blocksize)) {
1368 EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
1369 brelse(bh);
1370 return -EIO;
1371 }
1372 len = ((char *) root) + blocksize - (char *) de;
1373
1374 /* Allocate new block for the 0th block's dirents */
1375 bh2 = ext4_append(handle, dir, &block, &retval);
1376 if (!(bh2)) {
1377 brelse(bh);
1378 return retval;
1379 }
1380 ext4_set_inode_flag(dir, EXT4_INODE_INDEX);
1381 data1 = bh2->b_data;
1382
1383 memcpy (data1, de, len);
1384 de = (struct ext4_dir_entry_2 *) data1;
1385 top = data1 + len;
1386 while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
1387 de = de2;
1388 de->rec_len = ext4_rec_len_to_disk(data1 + blocksize - (char *) de,
1389 blocksize);
1390 /* Initialize the root; the dot dirents already exist */
1391 de = (struct ext4_dir_entry_2 *) (&root->dotdot);
1392 de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
1393 blocksize);
1394 memset (&root->info, 0, sizeof(root->info));
1395 root->info.info_length = sizeof(root->info);
1396 root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
1397 entries = root->entries;
1398 dx_set_block(entries, 1);
1399 dx_set_count(entries, 1);
1400 dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
1401
1402 /* Initialize as for dx_probe */
1403 hinfo.hash_version = root->info.hash_version;
1404 if (hinfo.hash_version <= DX_HASH_TEA)
1405 hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
1406 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
1407 ext4fs_dirhash(name, namelen, &hinfo);
1408 frame = frames;
1409 frame->entries = entries;
1410 frame->at = entries;
1411 frame->bh = bh;
1412 bh = bh2;
1413
1414 ext4_handle_dirty_metadata(handle, dir, frame->bh);
1415 ext4_handle_dirty_metadata(handle, dir, bh);
1416
1417 de = do_split(handle,dir, &bh, frame, &hinfo, &retval);
1418 if (!de) {
1419 /*
1420 * Even if the block split failed, we have to properly write
1421 * out all the changes we did so far. Otherwise we can end up
1422 * with corrupted filesystem.
1423 */
1424 ext4_mark_inode_dirty(handle, dir);
1425 dx_release(frames);
1426 return retval;
1427 }
1428 dx_release(frames);
1429
1430 retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
1431 brelse(bh);
1432 return retval;
1433}
1434
1435/*
1436 * ext4_add_entry()
1437 *
1438 * adds a file entry to the specified directory, using the same
1439 * semantics as ext4_find_entry(). It returns NULL if it failed.
1440 *
1441 * NOTE!! The inode part of 'de' is left at 0 - which means you
1442 * may not sleep between calling this and putting something into
1443 * the entry, as someone else might have used it while you slept.
1444 */
1445static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
1446 struct inode *inode)
1447{
1448 struct inode *dir = dentry->d_parent->d_inode;
1449 struct buffer_head *bh;
1450 struct ext4_dir_entry_2 *de;
1451 struct super_block *sb;
1452 int retval;
1453 int dx_fallback=0;
1454 unsigned blocksize;
1455 ext4_lblk_t block, blocks;
1456
1457 sb = dir->i_sb;
1458 blocksize = sb->s_blocksize;
1459 if (!dentry->d_name.len)
1460 return -EINVAL;
1461 if (is_dx(dir)) {
1462 retval = ext4_dx_add_entry(handle, dentry, inode);
1463 if (!retval || (retval != ERR_BAD_DX_DIR))
1464 return retval;
1465 ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
1466 dx_fallback++;
1467 ext4_mark_inode_dirty(handle, dir);
1468 }
1469 blocks = dir->i_size >> sb->s_blocksize_bits;
1470 for (block = 0; block < blocks; block++) {
1471 bh = ext4_bread(handle, dir, block, 0, &retval);
1472 if(!bh)
1473 return retval;
1474 retval = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
1475 if (retval != -ENOSPC) {
1476 brelse(bh);
1477 return retval;
1478 }
1479
1480 if (blocks == 1 && !dx_fallback &&
1481 EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX))
1482 return make_indexed_dir(handle, dentry, inode, bh);
1483 brelse(bh);
1484 }
1485 bh = ext4_append(handle, dir, &block, &retval);
1486 if (!bh)
1487 return retval;
1488 de = (struct ext4_dir_entry_2 *) bh->b_data;
1489 de->inode = 0;
1490 de->rec_len = ext4_rec_len_to_disk(blocksize, blocksize);
1491 retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
1492 brelse(bh);
1493 if (retval == 0)
1494 ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY);
1495 return retval;
1496}
1497
1498/*
1499 * Returns 0 for success, or a negative error value
1500 */
1501static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
1502 struct inode *inode)
1503{
1504 struct dx_frame frames[2], *frame;
1505 struct dx_entry *entries, *at;
1506 struct dx_hash_info hinfo;
1507 struct buffer_head *bh;
1508 struct inode *dir = dentry->d_parent->d_inode;
1509 struct super_block *sb = dir->i_sb;
1510 struct ext4_dir_entry_2 *de;
1511 int err;
1512
1513 frame = dx_probe(&dentry->d_name, dir, &hinfo, frames, &err);
1514 if (!frame)
1515 return err;
1516 entries = frame->entries;
1517 at = frame->at;
1518
1519 if (!(bh = ext4_bread(handle,dir, dx_get_block(frame->at), 0, &err)))
1520 goto cleanup;
1521
1522 BUFFER_TRACE(bh, "get_write_access");
1523 err = ext4_journal_get_write_access(handle, bh);
1524 if (err)
1525 goto journal_error;
1526
1527 err = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
1528 if (err != -ENOSPC)
1529 goto cleanup;
1530
1531 /* Block full, should compress but for now just split */
1532 dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
1533 dx_get_count(entries), dx_get_limit(entries)));
1534 /* Need to split index? */
1535 if (dx_get_count(entries) == dx_get_limit(entries)) {
1536 ext4_lblk_t newblock;
1537 unsigned icount = dx_get_count(entries);
1538 int levels = frame - frames;
1539 struct dx_entry *entries2;
1540 struct dx_node *node2;
1541 struct buffer_head *bh2;
1542
1543 if (levels && (dx_get_count(frames->entries) ==
1544 dx_get_limit(frames->entries))) {
1545 ext4_warning(sb, "Directory index full!");
1546 err = -ENOSPC;
1547 goto cleanup;
1548 }
1549 bh2 = ext4_append (handle, dir, &newblock, &err);
1550 if (!(bh2))
1551 goto cleanup;
1552 node2 = (struct dx_node *)(bh2->b_data);
1553 entries2 = node2->entries;
1554 memset(&node2->fake, 0, sizeof(struct fake_dirent));
1555 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
1556 sb->s_blocksize);
1557 BUFFER_TRACE(frame->bh, "get_write_access");
1558 err = ext4_journal_get_write_access(handle, frame->bh);
1559 if (err)
1560 goto journal_error;
1561 if (levels) {
1562 unsigned icount1 = icount/2, icount2 = icount - icount1;
1563 unsigned hash2 = dx_get_hash(entries + icount1);
1564 dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
1565 icount1, icount2));
1566
1567 BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
1568 err = ext4_journal_get_write_access(handle,
1569 frames[0].bh);
1570 if (err)
1571 goto journal_error;
1572
1573 memcpy((char *) entries2, (char *) (entries + icount1),
1574 icount2 * sizeof(struct dx_entry));
1575 dx_set_count(entries, icount1);
1576 dx_set_count(entries2, icount2);
1577 dx_set_limit(entries2, dx_node_limit(dir));
1578
1579 /* Which index block gets the new entry? */
1580 if (at - entries >= icount1) {
1581 frame->at = at = at - entries - icount1 + entries2;
1582 frame->entries = entries = entries2;
1583 swap(frame->bh, bh2);
1584 }
1585 dx_insert_block(frames + 0, hash2, newblock);
1586 dxtrace(dx_show_index("node", frames[1].entries));
1587 dxtrace(dx_show_index("node",
1588 ((struct dx_node *) bh2->b_data)->entries));
1589 err = ext4_handle_dirty_metadata(handle, inode, bh2);
1590 if (err)
1591 goto journal_error;
1592 brelse (bh2);
1593 } else {
1594 dxtrace(printk(KERN_DEBUG
1595 "Creating second level index...\n"));
1596 memcpy((char *) entries2, (char *) entries,
1597 icount * sizeof(struct dx_entry));
1598 dx_set_limit(entries2, dx_node_limit(dir));
1599
1600 /* Set up root */
1601 dx_set_count(entries, 1);
1602 dx_set_block(entries + 0, newblock);
1603 ((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels = 1;
1604
1605 /* Add new access path frame */
1606 frame = frames + 1;
1607 frame->at = at = at - entries + entries2;
1608 frame->entries = entries = entries2;
1609 frame->bh = bh2;
1610 err = ext4_journal_get_write_access(handle,
1611 frame->bh);
1612 if (err)
1613 goto journal_error;
1614 }
1615 err = ext4_handle_dirty_metadata(handle, inode, frames[0].bh);
1616 if (err) {
1617 ext4_std_error(inode->i_sb, err);
1618 goto cleanup;
1619 }
1620 }
1621 de = do_split(handle, dir, &bh, frame, &hinfo, &err);
1622 if (!de)
1623 goto cleanup;
1624 err = add_dirent_to_buf(handle, dentry, inode, de, bh);
1625 goto cleanup;
1626
1627journal_error:
1628 ext4_std_error(dir->i_sb, err);
1629cleanup:
1630 if (bh)
1631 brelse(bh);
1632 dx_release(frames);
1633 return err;
1634}
1635
1636/*
1637 * ext4_delete_entry deletes a directory entry by merging it with the
1638 * previous entry
1639 */
1640static int ext4_delete_entry(handle_t *handle,
1641 struct inode *dir,
1642 struct ext4_dir_entry_2 *de_del,
1643 struct buffer_head *bh)
1644{
1645 struct ext4_dir_entry_2 *de, *pde;
1646 unsigned int blocksize = dir->i_sb->s_blocksize;
1647 int i, err;
1648
1649 i = 0;
1650 pde = NULL;
1651 de = (struct ext4_dir_entry_2 *) bh->b_data;
1652 while (i < bh->b_size) {
1653 if (ext4_check_dir_entry(dir, NULL, de, bh, i))
1654 return -EIO;
1655 if (de == de_del) {
1656 BUFFER_TRACE(bh, "get_write_access");
1657 err = ext4_journal_get_write_access(handle, bh);
1658 if (unlikely(err)) {
1659 ext4_std_error(dir->i_sb, err);
1660 return err;
1661 }
1662 if (pde)
1663 pde->rec_len = ext4_rec_len_to_disk(
1664 ext4_rec_len_from_disk(pde->rec_len,
1665 blocksize) +
1666 ext4_rec_len_from_disk(de->rec_len,
1667 blocksize),
1668 blocksize);
1669 else
1670 de->inode = 0;
1671 dir->i_version++;
1672 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1673 err = ext4_handle_dirty_metadata(handle, dir, bh);
1674 if (unlikely(err)) {
1675 ext4_std_error(dir->i_sb, err);
1676 return err;
1677 }
1678 return 0;
1679 }
1680 i += ext4_rec_len_from_disk(de->rec_len, blocksize);
1681 pde = de;
1682 de = ext4_next_entry(de, blocksize);
1683 }
1684 return -ENOENT;
1685}
1686
1687/*
1688 * DIR_NLINK feature is set if 1) nlinks > EXT4_LINK_MAX or 2) nlinks == 2,
1689 * since this indicates that nlinks count was previously 1.
1690 */
1691static void ext4_inc_count(handle_t *handle, struct inode *inode)
1692{
1693 inc_nlink(inode);
1694 if (is_dx(inode) && inode->i_nlink > 1) {
1695 /* limit is 16-bit i_links_count */
1696 if (inode->i_nlink >= EXT4_LINK_MAX || inode->i_nlink == 2) {
1697 inode->i_nlink = 1;
1698 EXT4_SET_RO_COMPAT_FEATURE(inode->i_sb,
1699 EXT4_FEATURE_RO_COMPAT_DIR_NLINK);
1700 }
1701 }
1702}
1703
1704/*
1705 * If a directory had nlink == 1, then we should let it be 1. This indicates
1706 * directory has >EXT4_LINK_MAX subdirs.
1707 */
1708static void ext4_dec_count(handle_t *handle, struct inode *inode)
1709{
1710 drop_nlink(inode);
1711 if (S_ISDIR(inode->i_mode) && inode->i_nlink == 0)
1712 inc_nlink(inode);
1713}
1714
1715
1716static int ext4_add_nondir(handle_t *handle,
1717 struct dentry *dentry, struct inode *inode)
1718{
1719 int err = ext4_add_entry(handle, dentry, inode);
1720 if (!err) {
1721 ext4_mark_inode_dirty(handle, inode);
1722 d_instantiate(dentry, inode);
1723 unlock_new_inode(inode);
1724 return 0;
1725 }
1726 drop_nlink(inode);
1727 unlock_new_inode(inode);
1728 iput(inode);
1729 return err;
1730}
1731
1732/*
1733 * By the time this is called, we already have created
1734 * the directory cache entry for the new file, but it
1735 * is so far negative - it has no inode.
1736 *
1737 * If the create succeeds, we fill in the inode information
1738 * with d_instantiate().
1739 */
1740static int ext4_create(struct inode *dir, struct dentry *dentry, int mode,
1741 struct nameidata *nd)
1742{
1743 handle_t *handle;
1744 struct inode *inode;
1745 int err, retries = 0;
1746
1747 dquot_initialize(dir);
1748
1749retry:
1750 handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
1751 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
1752 EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
1753 if (IS_ERR(handle))
1754 return PTR_ERR(handle);
1755
1756 if (IS_DIRSYNC(dir))
1757 ext4_handle_sync(handle);
1758
1759 inode = ext4_new_inode(handle, dir, mode, &dentry->d_name, 0);
1760 err = PTR_ERR(inode);
1761 if (!IS_ERR(inode)) {
1762 inode->i_op = &ext4_file_inode_operations;
1763 inode->i_fop = &ext4_file_operations;
1764 ext4_set_aops(inode);
1765 err = ext4_add_nondir(handle, dentry, inode);
1766 }
1767 ext4_journal_stop(handle);
1768 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
1769 goto retry;
1770 return err;
1771}
1772
1773static int ext4_mknod(struct inode *dir, struct dentry *dentry,
1774 int mode, dev_t rdev)
1775{
1776 handle_t *handle;
1777 struct inode *inode;
1778 int err, retries = 0;
1779
1780 if (!new_valid_dev(rdev))
1781 return -EINVAL;
1782
1783 dquot_initialize(dir);
1784
1785retry:
1786 handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
1787 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
1788 EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
1789 if (IS_ERR(handle))
1790 return PTR_ERR(handle);
1791
1792 if (IS_DIRSYNC(dir))
1793 ext4_handle_sync(handle);
1794
1795 inode = ext4_new_inode(handle, dir, mode, &dentry->d_name, 0);
1796 err = PTR_ERR(inode);
1797 if (!IS_ERR(inode)) {
1798 init_special_inode(inode, inode->i_mode, rdev);
1799#ifdef CONFIG_EXT4_FS_XATTR
1800 inode->i_op = &ext4_special_inode_operations;
1801#endif
1802 err = ext4_add_nondir(handle, dentry, inode);
1803 }
1804 ext4_journal_stop(handle);
1805 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
1806 goto retry;
1807 return err;
1808}
1809
1810static int ext4_mkdir(struct inode *dir, struct dentry *dentry, int mode)
1811{
1812 handle_t *handle;
1813 struct inode *inode;
1814 struct buffer_head *dir_block = NULL;
1815 struct ext4_dir_entry_2 *de;
1816 unsigned int blocksize = dir->i_sb->s_blocksize;
1817 int err, retries = 0;
1818
1819 if (EXT4_DIR_LINK_MAX(dir))
1820 return -EMLINK;
1821
1822 dquot_initialize(dir);
1823
1824retry:
1825 handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
1826 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
1827 EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
1828 if (IS_ERR(handle))
1829 return PTR_ERR(handle);
1830
1831 if (IS_DIRSYNC(dir))
1832 ext4_handle_sync(handle);
1833
1834 inode = ext4_new_inode(handle, dir, S_IFDIR | mode,
1835 &dentry->d_name, 0);
1836 err = PTR_ERR(inode);
1837 if (IS_ERR(inode))
1838 goto out_stop;
1839
1840 inode->i_op = &ext4_dir_inode_operations;
1841 inode->i_fop = &ext4_dir_operations;
1842 inode->i_size = EXT4_I(inode)->i_disksize = inode->i_sb->s_blocksize;
1843 dir_block = ext4_bread(handle, inode, 0, 1, &err);
1844 if (!dir_block)
1845 goto out_clear_inode;
1846 BUFFER_TRACE(dir_block, "get_write_access");
1847 err = ext4_journal_get_write_access(handle, dir_block);
1848 if (err)
1849 goto out_clear_inode;
1850 de = (struct ext4_dir_entry_2 *) dir_block->b_data;
1851 de->inode = cpu_to_le32(inode->i_ino);
1852 de->name_len = 1;
1853 de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
1854 blocksize);
1855 strcpy(de->name, ".");
1856 ext4_set_de_type(dir->i_sb, de, S_IFDIR);
1857 de = ext4_next_entry(de, blocksize);
1858 de->inode = cpu_to_le32(dir->i_ino);
1859 de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(1),
1860 blocksize);
1861 de->name_len = 2;
1862 strcpy(de->name, "..");
1863 ext4_set_de_type(dir->i_sb, de, S_IFDIR);
1864 inode->i_nlink = 2;
1865 BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
1866 err = ext4_handle_dirty_metadata(handle, dir, dir_block);
1867 if (err)
1868 goto out_clear_inode;
1869 err = ext4_mark_inode_dirty(handle, inode);
1870 if (!err)
1871 err = ext4_add_entry(handle, dentry, inode);
1872 if (err) {
1873out_clear_inode:
1874 clear_nlink(inode);
1875 unlock_new_inode(inode);
1876 ext4_mark_inode_dirty(handle, inode);
1877 iput(inode);
1878 goto out_stop;
1879 }
1880 ext4_inc_count(handle, dir);
1881 ext4_update_dx_flag(dir);
1882 err = ext4_mark_inode_dirty(handle, dir);
1883 if (err)
1884 goto out_clear_inode;
1885 d_instantiate(dentry, inode);
1886 unlock_new_inode(inode);
1887out_stop:
1888 brelse(dir_block);
1889 ext4_journal_stop(handle);
1890 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
1891 goto retry;
1892 return err;
1893}
1894
1895/*
1896 * routine to check that the specified directory is empty (for rmdir)
1897 */
1898static int empty_dir(struct inode *inode)
1899{
1900 unsigned int offset;
1901 struct buffer_head *bh;
1902 struct ext4_dir_entry_2 *de, *de1;
1903 struct super_block *sb;
1904 int err = 0;
1905
1906 sb = inode->i_sb;
1907 if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2) ||
1908 !(bh = ext4_bread(NULL, inode, 0, 0, &err))) {
1909 if (err)
1910 EXT4_ERROR_INODE(inode,
1911 "error %d reading directory lblock 0", err);
1912 else
1913 ext4_warning(inode->i_sb,
1914 "bad directory (dir #%lu) - no data block",
1915 inode->i_ino);
1916 return 1;
1917 }
1918 de = (struct ext4_dir_entry_2 *) bh->b_data;
1919 de1 = ext4_next_entry(de, sb->s_blocksize);
1920 if (le32_to_cpu(de->inode) != inode->i_ino ||
1921 !le32_to_cpu(de1->inode) ||
1922 strcmp(".", de->name) ||
1923 strcmp("..", de1->name)) {
1924 ext4_warning(inode->i_sb,
1925 "bad directory (dir #%lu) - no `.' or `..'",
1926 inode->i_ino);
1927 brelse(bh);
1928 return 1;
1929 }
1930 offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) +
1931 ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize);
1932 de = ext4_next_entry(de1, sb->s_blocksize);
1933 while (offset < inode->i_size) {
1934 if (!bh ||
1935 (void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
1936 unsigned int lblock;
1937 err = 0;
1938 brelse(bh);
1939 lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb);
1940 bh = ext4_bread(NULL, inode, lblock, 0, &err);
1941 if (!bh) {
1942 if (err)
1943 EXT4_ERROR_INODE(inode,
1944 "error %d reading directory "
1945 "lblock %u", err, lblock);
1946 offset += sb->s_blocksize;
1947 continue;
1948 }
1949 de = (struct ext4_dir_entry_2 *) bh->b_data;
1950 }
1951 if (ext4_check_dir_entry(inode, NULL, de, bh, offset)) {
1952 de = (struct ext4_dir_entry_2 *)(bh->b_data +
1953 sb->s_blocksize);
1954 offset = (offset | (sb->s_blocksize - 1)) + 1;
1955 continue;
1956 }
1957 if (le32_to_cpu(de->inode)) {
1958 brelse(bh);
1959 return 0;
1960 }
1961 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
1962 de = ext4_next_entry(de, sb->s_blocksize);
1963 }
1964 brelse(bh);
1965 return 1;
1966}
1967
1968/* ext4_orphan_add() links an unlinked or truncated inode into a list of
1969 * such inodes, starting at the superblock, in case we crash before the
1970 * file is closed/deleted, or in case the inode truncate spans multiple
1971 * transactions and the last transaction is not recovered after a crash.
1972 *
1973 * At filesystem recovery time, we walk this list deleting unlinked
1974 * inodes and truncating linked inodes in ext4_orphan_cleanup().
1975 */
1976int ext4_orphan_add(handle_t *handle, struct inode *inode)
1977{
1978 struct super_block *sb = inode->i_sb;
1979 struct ext4_iloc iloc;
1980 int err = 0, rc;
1981
1982 if (!ext4_handle_valid(handle))
1983 return 0;
1984
1985 mutex_lock(&EXT4_SB(sb)->s_orphan_lock);
1986 if (!list_empty(&EXT4_I(inode)->i_orphan))
1987 goto out_unlock;
1988
1989 /*
1990 * Orphan handling is only valid for files with data blocks
1991 * being truncated, or files being unlinked. Note that we either
1992 * hold i_mutex, or the inode can not be referenced from outside,
1993 * so i_nlink should not be bumped due to race
1994 */
1995 J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
1996 S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
1997
1998 BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access");
1999 err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
2000 if (err)
2001 goto out_unlock;
2002
2003 err = ext4_reserve_inode_write(handle, inode, &iloc);
2004 if (err)
2005 goto out_unlock;
2006 /*
2007 * Due to previous errors inode may be already a part of on-disk
2008 * orphan list. If so skip on-disk list modification.
2009 */
2010 if (NEXT_ORPHAN(inode) && NEXT_ORPHAN(inode) <=
2011 (le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count)))
2012 goto mem_insert;
2013
2014 /* Insert this inode at the head of the on-disk orphan list... */
2015 NEXT_ORPHAN(inode) = le32_to_cpu(EXT4_SB(sb)->s_es->s_last_orphan);
2016 EXT4_SB(sb)->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
2017 err = ext4_handle_dirty_metadata(handle, NULL, EXT4_SB(sb)->s_sbh);
2018 rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
2019 if (!err)
2020 err = rc;
2021
2022 /* Only add to the head of the in-memory list if all the
2023 * previous operations succeeded. If the orphan_add is going to
2024 * fail (possibly taking the journal offline), we can't risk
2025 * leaving the inode on the orphan list: stray orphan-list
2026 * entries can cause panics at unmount time.
2027 *
2028 * This is safe: on error we're going to ignore the orphan list
2029 * anyway on the next recovery. */
2030mem_insert:
2031 if (!err)
2032 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2033
2034 jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
2035 jbd_debug(4, "orphan inode %lu will point to %d\n",
2036 inode->i_ino, NEXT_ORPHAN(inode));
2037out_unlock:
2038 mutex_unlock(&EXT4_SB(sb)->s_orphan_lock);
2039 ext4_std_error(inode->i_sb, err);
2040 return err;
2041}
2042
2043/*
2044 * ext4_orphan_del() removes an unlinked or truncated inode from the list
2045 * of such inodes stored on disk, because it is finally being cleaned up.
2046 */
2047int ext4_orphan_del(handle_t *handle, struct inode *inode)
2048{
2049 struct list_head *prev;
2050 struct ext4_inode_info *ei = EXT4_I(inode);
2051 struct ext4_sb_info *sbi;
2052 __u32 ino_next;
2053 struct ext4_iloc iloc;
2054 int err = 0;
2055
2056 /* ext4_handle_valid() assumes a valid handle_t pointer */
2057 if (handle && !ext4_handle_valid(handle))
2058 return 0;
2059
2060 mutex_lock(&EXT4_SB(inode->i_sb)->s_orphan_lock);
2061 if (list_empty(&ei->i_orphan))
2062 goto out;
2063
2064 ino_next = NEXT_ORPHAN(inode);
2065 prev = ei->i_orphan.prev;
2066 sbi = EXT4_SB(inode->i_sb);
2067
2068 jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
2069
2070 list_del_init(&ei->i_orphan);
2071
2072 /* If we're on an error path, we may not have a valid
2073 * transaction handle with which to update the orphan list on
2074 * disk, but we still need to remove the inode from the linked
2075 * list in memory. */
2076 if (sbi->s_journal && !handle)
2077 goto out;
2078
2079 err = ext4_reserve_inode_write(handle, inode, &iloc);
2080 if (err)
2081 goto out_err;
2082
2083 if (prev == &sbi->s_orphan) {
2084 jbd_debug(4, "superblock will point to %u\n", ino_next);
2085 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2086 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2087 if (err)
2088 goto out_brelse;
2089 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
2090 err = ext4_handle_dirty_metadata(handle, NULL, sbi->s_sbh);
2091 } else {
2092 struct ext4_iloc iloc2;
2093 struct inode *i_prev =
2094 &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
2095
2096 jbd_debug(4, "orphan inode %lu will point to %u\n",
2097 i_prev->i_ino, ino_next);
2098 err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
2099 if (err)
2100 goto out_brelse;
2101 NEXT_ORPHAN(i_prev) = ino_next;
2102 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
2103 }
2104 if (err)
2105 goto out_brelse;
2106 NEXT_ORPHAN(inode) = 0;
2107 err = ext4_mark_iloc_dirty(handle, inode, &iloc);
2108
2109out_err:
2110 ext4_std_error(inode->i_sb, err);
2111out:
2112 mutex_unlock(&EXT4_SB(inode->i_sb)->s_orphan_lock);
2113 return err;
2114
2115out_brelse:
2116 brelse(iloc.bh);
2117 goto out_err;
2118}
2119
2120static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
2121{
2122 int retval;
2123 struct inode *inode;
2124 struct buffer_head *bh;
2125 struct ext4_dir_entry_2 *de;
2126 handle_t *handle;
2127
2128 /* Initialize quotas before so that eventual writes go in
2129 * separate transaction */
2130 dquot_initialize(dir);
2131 dquot_initialize(dentry->d_inode);
2132
2133 handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb));
2134 if (IS_ERR(handle))
2135 return PTR_ERR(handle);
2136
2137 retval = -ENOENT;
2138 bh = ext4_find_entry(dir, &dentry->d_name, &de);
2139 if (!bh)
2140 goto end_rmdir;
2141
2142 if (IS_DIRSYNC(dir))
2143 ext4_handle_sync(handle);
2144
2145 inode = dentry->d_inode;
2146
2147 retval = -EIO;
2148 if (le32_to_cpu(de->inode) != inode->i_ino)
2149 goto end_rmdir;
2150
2151 retval = -ENOTEMPTY;
2152 if (!empty_dir(inode))
2153 goto end_rmdir;
2154
2155 retval = ext4_delete_entry(handle, dir, de, bh);
2156 if (retval)
2157 goto end_rmdir;
2158 if (!EXT4_DIR_LINK_EMPTY(inode))
2159 ext4_warning(inode->i_sb,
2160 "empty directory has too many links (%d)",
2161 inode->i_nlink);
2162 inode->i_version++;
2163 clear_nlink(inode);
2164 /* There's no need to set i_disksize: the fact that i_nlink is
2165 * zero will ensure that the right thing happens during any
2166 * recovery. */
2167 inode->i_size = 0;
2168 ext4_orphan_add(handle, inode);
2169 inode->i_ctime = dir->i_ctime = dir->i_mtime = ext4_current_time(inode);
2170 ext4_mark_inode_dirty(handle, inode);
2171 ext4_dec_count(handle, dir);
2172 ext4_update_dx_flag(dir);
2173 ext4_mark_inode_dirty(handle, dir);
2174
2175end_rmdir:
2176 ext4_journal_stop(handle);
2177 brelse(bh);
2178 return retval;
2179}
2180
2181static int ext4_unlink(struct inode *dir, struct dentry *dentry)
2182{
2183 int retval;
2184 struct inode *inode;
2185 struct buffer_head *bh;
2186 struct ext4_dir_entry_2 *de;
2187 handle_t *handle;
2188
2189 trace_ext4_unlink_enter(dir, dentry);
2190 /* Initialize quotas before so that eventual writes go
2191 * in separate transaction */
2192 dquot_initialize(dir);
2193 dquot_initialize(dentry->d_inode);
2194
2195 handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb));
2196 if (IS_ERR(handle))
2197 return PTR_ERR(handle);
2198
2199 if (IS_DIRSYNC(dir))
2200 ext4_handle_sync(handle);
2201
2202 retval = -ENOENT;
2203 bh = ext4_find_entry(dir, &dentry->d_name, &de);
2204 if (!bh)
2205 goto end_unlink;
2206
2207 inode = dentry->d_inode;
2208
2209 retval = -EIO;
2210 if (le32_to_cpu(de->inode) != inode->i_ino)
2211 goto end_unlink;
2212
2213 if (!inode->i_nlink) {
2214 ext4_warning(inode->i_sb,
2215 "Deleting nonexistent file (%lu), %d",
2216 inode->i_ino, inode->i_nlink);
2217 inode->i_nlink = 1;
2218 }
2219 retval = ext4_delete_entry(handle, dir, de, bh);
2220 if (retval)
2221 goto end_unlink;
2222 dir->i_ctime = dir->i_mtime = ext4_current_time(dir);
2223 ext4_update_dx_flag(dir);
2224 ext4_mark_inode_dirty(handle, dir);
2225 drop_nlink(inode);
2226 if (!inode->i_nlink)
2227 ext4_orphan_add(handle, inode);
2228 inode->i_ctime = ext4_current_time(inode);
2229 ext4_mark_inode_dirty(handle, inode);
2230 retval = 0;
2231
2232end_unlink:
2233 ext4_journal_stop(handle);
2234 brelse(bh);
2235 trace_ext4_unlink_exit(dentry, retval);
2236 return retval;
2237}
2238
2239static int ext4_symlink(struct inode *dir,
2240 struct dentry *dentry, const char *symname)
2241{
2242 handle_t *handle;
2243 struct inode *inode;
2244 int l, err, retries = 0;
2245 int credits;
2246
2247 l = strlen(symname)+1;
2248 if (l > dir->i_sb->s_blocksize)
2249 return -ENAMETOOLONG;
2250
2251 dquot_initialize(dir);
2252
2253 if (l > EXT4_N_BLOCKS * 4) {
2254 /*
2255 * For non-fast symlinks, we just allocate inode and put it on
2256 * orphan list in the first transaction => we need bitmap,
2257 * group descriptor, sb, inode block, quota blocks, and
2258 * possibly selinux xattr blocks.
2259 */
2260 credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
2261 EXT4_XATTR_TRANS_BLOCKS;
2262 } else {
2263 /*
2264 * Fast symlink. We have to add entry to directory
2265 * (EXT4_DATA_TRANS_BLOCKS + EXT4_INDEX_EXTRA_TRANS_BLOCKS),
2266 * allocate new inode (bitmap, group descriptor, inode block,
2267 * quota blocks, sb is already counted in previous macros).
2268 */
2269 credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2270 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
2271 EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb);
2272 }
2273retry:
2274 handle = ext4_journal_start(dir, credits);
2275 if (IS_ERR(handle))
2276 return PTR_ERR(handle);
2277
2278 if (IS_DIRSYNC(dir))
2279 ext4_handle_sync(handle);
2280
2281 inode = ext4_new_inode(handle, dir, S_IFLNK|S_IRWXUGO,
2282 &dentry->d_name, 0);
2283 err = PTR_ERR(inode);
2284 if (IS_ERR(inode))
2285 goto out_stop;
2286
2287 if (l > EXT4_N_BLOCKS * 4) {
2288 inode->i_op = &ext4_symlink_inode_operations;
2289 ext4_set_aops(inode);
2290 /*
2291 * We cannot call page_symlink() with transaction started
2292 * because it calls into ext4_write_begin() which can wait
2293 * for transaction commit if we are running out of space
2294 * and thus we deadlock. So we have to stop transaction now
2295 * and restart it when symlink contents is written.
2296 *
2297 * To keep fs consistent in case of crash, we have to put inode
2298 * to orphan list in the mean time.
2299 */
2300 drop_nlink(inode);
2301 err = ext4_orphan_add(handle, inode);
2302 ext4_journal_stop(handle);
2303 if (err)
2304 goto err_drop_inode;
2305 err = __page_symlink(inode, symname, l, 1);
2306 if (err)
2307 goto err_drop_inode;
2308 /*
2309 * Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS
2310 * + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified
2311 */
2312 handle = ext4_journal_start(dir,
2313 EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2314 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1);
2315 if (IS_ERR(handle)) {
2316 err = PTR_ERR(handle);
2317 goto err_drop_inode;
2318 }
2319 inc_nlink(inode);
2320 err = ext4_orphan_del(handle, inode);
2321 if (err) {
2322 ext4_journal_stop(handle);
2323 clear_nlink(inode);
2324 goto err_drop_inode;
2325 }
2326 } else {
2327 /* clear the extent format for fast symlink */
2328 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
2329 inode->i_op = &ext4_fast_symlink_inode_operations;
2330 memcpy((char *)&EXT4_I(inode)->i_data, symname, l);
2331 inode->i_size = l-1;
2332 }
2333 EXT4_I(inode)->i_disksize = inode->i_size;
2334 err = ext4_add_nondir(handle, dentry, inode);
2335out_stop:
2336 ext4_journal_stop(handle);
2337 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2338 goto retry;
2339 return err;
2340err_drop_inode:
2341 unlock_new_inode(inode);
2342 iput(inode);
2343 return err;
2344}
2345
2346static int ext4_link(struct dentry *old_dentry,
2347 struct inode *dir, struct dentry *dentry)
2348{
2349 handle_t *handle;
2350 struct inode *inode = old_dentry->d_inode;
2351 int err, retries = 0;
2352
2353 if (inode->i_nlink >= EXT4_LINK_MAX)
2354 return -EMLINK;
2355
2356 dquot_initialize(dir);
2357
2358retry:
2359 handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2360 EXT4_INDEX_EXTRA_TRANS_BLOCKS);
2361 if (IS_ERR(handle))
2362 return PTR_ERR(handle);
2363
2364 if (IS_DIRSYNC(dir))
2365 ext4_handle_sync(handle);
2366
2367 inode->i_ctime = ext4_current_time(inode);
2368 ext4_inc_count(handle, inode);
2369 ihold(inode);
2370
2371 err = ext4_add_entry(handle, dentry, inode);
2372 if (!err) {
2373 ext4_mark_inode_dirty(handle, inode);
2374 d_instantiate(dentry, inode);
2375 } else {
2376 drop_nlink(inode);
2377 iput(inode);
2378 }
2379 ext4_journal_stop(handle);
2380 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2381 goto retry;
2382 return err;
2383}
2384
2385#define PARENT_INO(buffer, size) \
2386 (ext4_next_entry((struct ext4_dir_entry_2 *)(buffer), size)->inode)
2387
2388/*
2389 * Anybody can rename anything with this: the permission checks are left to the
2390 * higher-level routines.
2391 */
2392static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
2393 struct inode *new_dir, struct dentry *new_dentry)
2394{
2395 handle_t *handle;
2396 struct inode *old_inode, *new_inode;
2397 struct buffer_head *old_bh, *new_bh, *dir_bh;
2398 struct ext4_dir_entry_2 *old_de, *new_de;
2399 int retval, force_da_alloc = 0;
2400
2401 dquot_initialize(old_dir);
2402 dquot_initialize(new_dir);
2403
2404 old_bh = new_bh = dir_bh = NULL;
2405
2406 /* Initialize quotas before so that eventual writes go
2407 * in separate transaction */
2408 if (new_dentry->d_inode)
2409 dquot_initialize(new_dentry->d_inode);
2410 handle = ext4_journal_start(old_dir, 2 *
2411 EXT4_DATA_TRANS_BLOCKS(old_dir->i_sb) +
2412 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
2413 if (IS_ERR(handle))
2414 return PTR_ERR(handle);
2415
2416 if (IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir))
2417 ext4_handle_sync(handle);
2418
2419 old_bh = ext4_find_entry(old_dir, &old_dentry->d_name, &old_de);
2420 /*
2421 * Check for inode number is _not_ due to possible IO errors.
2422 * We might rmdir the source, keep it as pwd of some process
2423 * and merrily kill the link to whatever was created under the
2424 * same name. Goodbye sticky bit ;-<
2425 */
2426 old_inode = old_dentry->d_inode;
2427 retval = -ENOENT;
2428 if (!old_bh || le32_to_cpu(old_de->inode) != old_inode->i_ino)
2429 goto end_rename;
2430
2431 new_inode = new_dentry->d_inode;
2432 new_bh = ext4_find_entry(new_dir, &new_dentry->d_name, &new_de);
2433 if (new_bh) {
2434 if (!new_inode) {
2435 brelse(new_bh);
2436 new_bh = NULL;
2437 }
2438 }
2439 if (S_ISDIR(old_inode->i_mode)) {
2440 if (new_inode) {
2441 retval = -ENOTEMPTY;
2442 if (!empty_dir(new_inode))
2443 goto end_rename;
2444 }
2445 retval = -EIO;
2446 dir_bh = ext4_bread(handle, old_inode, 0, 0, &retval);
2447 if (!dir_bh)
2448 goto end_rename;
2449 if (le32_to_cpu(PARENT_INO(dir_bh->b_data,
2450 old_dir->i_sb->s_blocksize)) != old_dir->i_ino)
2451 goto end_rename;
2452 retval = -EMLINK;
2453 if (!new_inode && new_dir != old_dir &&
2454 EXT4_DIR_LINK_MAX(new_dir))
2455 goto end_rename;
2456 BUFFER_TRACE(dir_bh, "get_write_access");
2457 retval = ext4_journal_get_write_access(handle, dir_bh);
2458 if (retval)
2459 goto end_rename;
2460 }
2461 if (!new_bh) {
2462 retval = ext4_add_entry(handle, new_dentry, old_inode);
2463 if (retval)
2464 goto end_rename;
2465 } else {
2466 BUFFER_TRACE(new_bh, "get write access");
2467 retval = ext4_journal_get_write_access(handle, new_bh);
2468 if (retval)
2469 goto end_rename;
2470 new_de->inode = cpu_to_le32(old_inode->i_ino);
2471 if (EXT4_HAS_INCOMPAT_FEATURE(new_dir->i_sb,
2472 EXT4_FEATURE_INCOMPAT_FILETYPE))
2473 new_de->file_type = old_de->file_type;
2474 new_dir->i_version++;
2475 new_dir->i_ctime = new_dir->i_mtime =
2476 ext4_current_time(new_dir);
2477 ext4_mark_inode_dirty(handle, new_dir);
2478 BUFFER_TRACE(new_bh, "call ext4_handle_dirty_metadata");
2479 retval = ext4_handle_dirty_metadata(handle, new_dir, new_bh);
2480 if (unlikely(retval)) {
2481 ext4_std_error(new_dir->i_sb, retval);
2482 goto end_rename;
2483 }
2484 brelse(new_bh);
2485 new_bh = NULL;
2486 }
2487
2488 /*
2489 * Like most other Unix systems, set the ctime for inodes on a
2490 * rename.
2491 */
2492 old_inode->i_ctime = ext4_current_time(old_inode);
2493 ext4_mark_inode_dirty(handle, old_inode);
2494
2495 /*
2496 * ok, that's it
2497 */
2498 if (le32_to_cpu(old_de->inode) != old_inode->i_ino ||
2499 old_de->name_len != old_dentry->d_name.len ||
2500 strncmp(old_de->name, old_dentry->d_name.name, old_de->name_len) ||
2501 (retval = ext4_delete_entry(handle, old_dir,
2502 old_de, old_bh)) == -ENOENT) {
2503 /* old_de could have moved from under us during htree split, so
2504 * make sure that we are deleting the right entry. We might
2505 * also be pointing to a stale entry in the unused part of
2506 * old_bh so just checking inum and the name isn't enough. */
2507 struct buffer_head *old_bh2;
2508 struct ext4_dir_entry_2 *old_de2;
2509
2510 old_bh2 = ext4_find_entry(old_dir, &old_dentry->d_name, &old_de2);
2511 if (old_bh2) {
2512 retval = ext4_delete_entry(handle, old_dir,
2513 old_de2, old_bh2);
2514 brelse(old_bh2);
2515 }
2516 }
2517 if (retval) {
2518 ext4_warning(old_dir->i_sb,
2519 "Deleting old file (%lu), %d, error=%d",
2520 old_dir->i_ino, old_dir->i_nlink, retval);
2521 }
2522
2523 if (new_inode) {
2524 ext4_dec_count(handle, new_inode);
2525 new_inode->i_ctime = ext4_current_time(new_inode);
2526 }
2527 old_dir->i_ctime = old_dir->i_mtime = ext4_current_time(old_dir);
2528 ext4_update_dx_flag(old_dir);
2529 if (dir_bh) {
2530 PARENT_INO(dir_bh->b_data, new_dir->i_sb->s_blocksize) =
2531 cpu_to_le32(new_dir->i_ino);
2532 BUFFER_TRACE(dir_bh, "call ext4_handle_dirty_metadata");
2533 retval = ext4_handle_dirty_metadata(handle, old_dir, dir_bh);
2534 if (retval) {
2535 ext4_std_error(old_dir->i_sb, retval);
2536 goto end_rename;
2537 }
2538 ext4_dec_count(handle, old_dir);
2539 if (new_inode) {
2540 /* checked empty_dir above, can't have another parent,
2541 * ext4_dec_count() won't work for many-linked dirs */
2542 new_inode->i_nlink = 0;
2543 } else {
2544 ext4_inc_count(handle, new_dir);
2545 ext4_update_dx_flag(new_dir);
2546 ext4_mark_inode_dirty(handle, new_dir);
2547 }
2548 }
2549 ext4_mark_inode_dirty(handle, old_dir);
2550 if (new_inode) {
2551 ext4_mark_inode_dirty(handle, new_inode);
2552 if (!new_inode->i_nlink)
2553 ext4_orphan_add(handle, new_inode);
2554 if (!test_opt(new_dir->i_sb, NO_AUTO_DA_ALLOC))
2555 force_da_alloc = 1;
2556 }
2557 retval = 0;
2558
2559end_rename:
2560 brelse(dir_bh);
2561 brelse(old_bh);
2562 brelse(new_bh);
2563 ext4_journal_stop(handle);
2564 if (retval == 0 && force_da_alloc)
2565 ext4_alloc_da_blocks(old_inode);
2566 return retval;
2567}
2568
2569/*
2570 * directories can handle most operations...
2571 */
2572const struct inode_operations ext4_dir_inode_operations = {
2573 .create = ext4_create,
2574 .lookup = ext4_lookup,
2575 .link = ext4_link,
2576 .unlink = ext4_unlink,
2577 .symlink = ext4_symlink,
2578 .mkdir = ext4_mkdir,
2579 .rmdir = ext4_rmdir,
2580 .mknod = ext4_mknod,
2581 .rename = ext4_rename,
2582 .setattr = ext4_setattr,
2583#ifdef CONFIG_EXT4_FS_XATTR
2584 .setxattr = generic_setxattr,
2585 .getxattr = generic_getxattr,
2586 .listxattr = ext4_listxattr,
2587 .removexattr = generic_removexattr,
2588#endif
2589 .get_acl = ext4_get_acl,
2590 .fiemap = ext4_fiemap,
2591};
2592
2593const struct inode_operations ext4_special_inode_operations = {
2594 .setattr = ext4_setattr,
2595#ifdef CONFIG_EXT4_FS_XATTR
2596 .setxattr = generic_setxattr,
2597 .getxattr = generic_getxattr,
2598 .listxattr = ext4_listxattr,
2599 .removexattr = generic_removexattr,
2600#endif
2601 .get_acl = ext4_get_acl,
2602};