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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// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/ext4/namei.c
4 *
5 * Copyright (C) 1992, 1993, 1994, 1995
6 * Remy Card (card@masi.ibp.fr)
7 * Laboratoire MASI - Institut Blaise Pascal
8 * Universite Pierre et Marie Curie (Paris VI)
9 *
10 * from
11 *
12 * linux/fs/minix/namei.c
13 *
14 * Copyright (C) 1991, 1992 Linus Torvalds
15 *
16 * Big-endian to little-endian byte-swapping/bitmaps by
17 * David S. Miller (davem@caip.rutgers.edu), 1995
18 * Directory entry file type support and forward compatibility hooks
19 * for B-tree directories by Theodore Ts'o (tytso@mit.edu), 1998
20 * Hash Tree Directory indexing (c)
21 * Daniel Phillips, 2001
22 * Hash Tree Directory indexing porting
23 * Christopher Li, 2002
24 * Hash Tree Directory indexing cleanup
25 * Theodore Ts'o, 2002
26 */
27
28#include <linux/fs.h>
29#include <linux/pagemap.h>
30#include <linux/time.h>
31#include <linux/fcntl.h>
32#include <linux/stat.h>
33#include <linux/string.h>
34#include <linux/quotaops.h>
35#include <linux/buffer_head.h>
36#include <linux/bio.h>
37#include <linux/iversion.h>
38#include <linux/unicode.h>
39#include "ext4.h"
40#include "ext4_jbd2.h"
41
42#include "xattr.h"
43#include "acl.h"
44
45#include <trace/events/ext4.h>
46/*
47 * define how far ahead to read directories while searching them.
48 */
49#define NAMEI_RA_CHUNKS 2
50#define NAMEI_RA_BLOCKS 4
51#define NAMEI_RA_SIZE (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS)
52
53static struct buffer_head *ext4_append(handle_t *handle,
54 struct inode *inode,
55 ext4_lblk_t *block)
56{
57 struct buffer_head *bh;
58 int err;
59
60 if (unlikely(EXT4_SB(inode->i_sb)->s_max_dir_size_kb &&
61 ((inode->i_size >> 10) >=
62 EXT4_SB(inode->i_sb)->s_max_dir_size_kb)))
63 return ERR_PTR(-ENOSPC);
64
65 *block = inode->i_size >> inode->i_sb->s_blocksize_bits;
66
67 bh = ext4_bread(handle, inode, *block, EXT4_GET_BLOCKS_CREATE);
68 if (IS_ERR(bh))
69 return bh;
70 inode->i_size += inode->i_sb->s_blocksize;
71 EXT4_I(inode)->i_disksize = inode->i_size;
72 BUFFER_TRACE(bh, "get_write_access");
73 err = ext4_journal_get_write_access(handle, bh);
74 if (err) {
75 brelse(bh);
76 ext4_std_error(inode->i_sb, err);
77 return ERR_PTR(err);
78 }
79 return bh;
80}
81
82static int ext4_dx_csum_verify(struct inode *inode,
83 struct ext4_dir_entry *dirent);
84
85/*
86 * Hints to ext4_read_dirblock regarding whether we expect a directory
87 * block being read to be an index block, or a block containing
88 * directory entries (and if the latter, whether it was found via a
89 * logical block in an htree index block). This is used to control
90 * what sort of sanity checkinig ext4_read_dirblock() will do on the
91 * directory block read from the storage device. EITHER will means
92 * the caller doesn't know what kind of directory block will be read,
93 * so no specific verification will be done.
94 */
95typedef enum {
96 EITHER, INDEX, DIRENT, DIRENT_HTREE
97} dirblock_type_t;
98
99#define ext4_read_dirblock(inode, block, type) \
100 __ext4_read_dirblock((inode), (block), (type), __func__, __LINE__)
101
102static struct buffer_head *__ext4_read_dirblock(struct inode *inode,
103 ext4_lblk_t block,
104 dirblock_type_t type,
105 const char *func,
106 unsigned int line)
107{
108 struct buffer_head *bh;
109 struct ext4_dir_entry *dirent;
110 int is_dx_block = 0;
111
112 if (ext4_simulate_fail(inode->i_sb, EXT4_SIM_DIRBLOCK_EIO))
113 bh = ERR_PTR(-EIO);
114 else
115 bh = ext4_bread(NULL, inode, block, 0);
116 if (IS_ERR(bh)) {
117 __ext4_warning(inode->i_sb, func, line,
118 "inode #%lu: lblock %lu: comm %s: "
119 "error %ld reading directory block",
120 inode->i_ino, (unsigned long)block,
121 current->comm, PTR_ERR(bh));
122
123 return bh;
124 }
125 if (!bh && (type == INDEX || type == DIRENT_HTREE)) {
126 ext4_error_inode(inode, func, line, block,
127 "Directory hole found for htree %s block",
128 (type == INDEX) ? "index" : "leaf");
129 return ERR_PTR(-EFSCORRUPTED);
130 }
131 if (!bh)
132 return NULL;
133 dirent = (struct ext4_dir_entry *) bh->b_data;
134 /* Determine whether or not we have an index block */
135 if (is_dx(inode)) {
136 if (block == 0)
137 is_dx_block = 1;
138 else if (ext4_rec_len_from_disk(dirent->rec_len,
139 inode->i_sb->s_blocksize) ==
140 inode->i_sb->s_blocksize)
141 is_dx_block = 1;
142 }
143 if (!is_dx_block && type == INDEX) {
144 ext4_error_inode(inode, func, line, block,
145 "directory leaf block found instead of index block");
146 brelse(bh);
147 return ERR_PTR(-EFSCORRUPTED);
148 }
149 if (!ext4_has_metadata_csum(inode->i_sb) ||
150 buffer_verified(bh))
151 return bh;
152
153 /*
154 * An empty leaf block can get mistaken for a index block; for
155 * this reason, we can only check the index checksum when the
156 * caller is sure it should be an index block.
157 */
158 if (is_dx_block && type == INDEX) {
159 if (ext4_dx_csum_verify(inode, dirent) &&
160 !ext4_simulate_fail(inode->i_sb, EXT4_SIM_DIRBLOCK_CRC))
161 set_buffer_verified(bh);
162 else {
163 ext4_error_inode_err(inode, func, line, block,
164 EFSBADCRC,
165 "Directory index failed checksum");
166 brelse(bh);
167 return ERR_PTR(-EFSBADCRC);
168 }
169 }
170 if (!is_dx_block) {
171 if (ext4_dirblock_csum_verify(inode, bh) &&
172 !ext4_simulate_fail(inode->i_sb, EXT4_SIM_DIRBLOCK_CRC))
173 set_buffer_verified(bh);
174 else {
175 ext4_error_inode_err(inode, func, line, block,
176 EFSBADCRC,
177 "Directory block failed checksum");
178 brelse(bh);
179 return ERR_PTR(-EFSBADCRC);
180 }
181 }
182 return bh;
183}
184
185#ifdef DX_DEBUG
186#define dxtrace(command) command
187#else
188#define dxtrace(command)
189#endif
190
191struct fake_dirent
192{
193 __le32 inode;
194 __le16 rec_len;
195 u8 name_len;
196 u8 file_type;
197};
198
199struct dx_countlimit
200{
201 __le16 limit;
202 __le16 count;
203};
204
205struct dx_entry
206{
207 __le32 hash;
208 __le32 block;
209};
210
211/*
212 * dx_root_info is laid out so that if it should somehow get overlaid by a
213 * dirent the two low bits of the hash version will be zero. Therefore, the
214 * hash version mod 4 should never be 0. Sincerely, the paranoia department.
215 */
216
217struct dx_root
218{
219 struct fake_dirent dot;
220 char dot_name[4];
221 struct fake_dirent dotdot;
222 char dotdot_name[4];
223 struct dx_root_info
224 {
225 __le32 reserved_zero;
226 u8 hash_version;
227 u8 info_length; /* 8 */
228 u8 indirect_levels;
229 u8 unused_flags;
230 }
231 info;
232 struct dx_entry entries[];
233};
234
235struct dx_node
236{
237 struct fake_dirent fake;
238 struct dx_entry entries[];
239};
240
241
242struct dx_frame
243{
244 struct buffer_head *bh;
245 struct dx_entry *entries;
246 struct dx_entry *at;
247};
248
249struct dx_map_entry
250{
251 u32 hash;
252 u16 offs;
253 u16 size;
254};
255
256/*
257 * This goes at the end of each htree block.
258 */
259struct dx_tail {
260 u32 dt_reserved;
261 __le32 dt_checksum; /* crc32c(uuid+inum+dirblock) */
262};
263
264static inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
265static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
266static inline unsigned dx_get_hash(struct dx_entry *entry);
267static void dx_set_hash(struct dx_entry *entry, unsigned value);
268static unsigned dx_get_count(struct dx_entry *entries);
269static unsigned dx_get_limit(struct dx_entry *entries);
270static void dx_set_count(struct dx_entry *entries, unsigned value);
271static void dx_set_limit(struct dx_entry *entries, unsigned value);
272static unsigned dx_root_limit(struct inode *dir, unsigned infosize);
273static unsigned dx_node_limit(struct inode *dir);
274static struct dx_frame *dx_probe(struct ext4_filename *fname,
275 struct inode *dir,
276 struct dx_hash_info *hinfo,
277 struct dx_frame *frame);
278static void dx_release(struct dx_frame *frames);
279static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de,
280 unsigned blocksize, struct dx_hash_info *hinfo,
281 struct dx_map_entry map[]);
282static void dx_sort_map(struct dx_map_entry *map, unsigned count);
283static struct ext4_dir_entry_2 *dx_move_dirents(struct inode *dir, char *from,
284 char *to, struct dx_map_entry *offsets,
285 int count, unsigned int blocksize);
286static struct ext4_dir_entry_2 *dx_pack_dirents(struct inode *dir, char *base,
287 unsigned int blocksize);
288static void dx_insert_block(struct dx_frame *frame,
289 u32 hash, ext4_lblk_t block);
290static int ext4_htree_next_block(struct inode *dir, __u32 hash,
291 struct dx_frame *frame,
292 struct dx_frame *frames,
293 __u32 *start_hash);
294static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
295 struct ext4_filename *fname,
296 struct ext4_dir_entry_2 **res_dir);
297static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
298 struct inode *dir, struct inode *inode);
299
300/* checksumming functions */
301void ext4_initialize_dirent_tail(struct buffer_head *bh,
302 unsigned int blocksize)
303{
304 struct ext4_dir_entry_tail *t = EXT4_DIRENT_TAIL(bh->b_data, blocksize);
305
306 memset(t, 0, sizeof(struct ext4_dir_entry_tail));
307 t->det_rec_len = ext4_rec_len_to_disk(
308 sizeof(struct ext4_dir_entry_tail), blocksize);
309 t->det_reserved_ft = EXT4_FT_DIR_CSUM;
310}
311
312/* Walk through a dirent block to find a checksum "dirent" at the tail */
313static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode,
314 struct buffer_head *bh)
315{
316 struct ext4_dir_entry_tail *t;
317
318#ifdef PARANOID
319 struct ext4_dir_entry *d, *top;
320
321 d = (struct ext4_dir_entry *)bh->b_data;
322 top = (struct ext4_dir_entry *)(bh->b_data +
323 (EXT4_BLOCK_SIZE(inode->i_sb) -
324 sizeof(struct ext4_dir_entry_tail)));
325 while (d < top && d->rec_len)
326 d = (struct ext4_dir_entry *)(((void *)d) +
327 le16_to_cpu(d->rec_len));
328
329 if (d != top)
330 return NULL;
331
332 t = (struct ext4_dir_entry_tail *)d;
333#else
334 t = EXT4_DIRENT_TAIL(bh->b_data, EXT4_BLOCK_SIZE(inode->i_sb));
335#endif
336
337 if (t->det_reserved_zero1 ||
338 le16_to_cpu(t->det_rec_len) != sizeof(struct ext4_dir_entry_tail) ||
339 t->det_reserved_zero2 ||
340 t->det_reserved_ft != EXT4_FT_DIR_CSUM)
341 return NULL;
342
343 return t;
344}
345
346static __le32 ext4_dirblock_csum(struct inode *inode, void *dirent, int size)
347{
348 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
349 struct ext4_inode_info *ei = EXT4_I(inode);
350 __u32 csum;
351
352 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
353 return cpu_to_le32(csum);
354}
355
356#define warn_no_space_for_csum(inode) \
357 __warn_no_space_for_csum((inode), __func__, __LINE__)
358
359static void __warn_no_space_for_csum(struct inode *inode, const char *func,
360 unsigned int line)
361{
362 __ext4_warning_inode(inode, func, line,
363 "No space for directory leaf checksum. Please run e2fsck -D.");
364}
365
366int ext4_dirblock_csum_verify(struct inode *inode, struct buffer_head *bh)
367{
368 struct ext4_dir_entry_tail *t;
369
370 if (!ext4_has_metadata_csum(inode->i_sb))
371 return 1;
372
373 t = get_dirent_tail(inode, bh);
374 if (!t) {
375 warn_no_space_for_csum(inode);
376 return 0;
377 }
378
379 if (t->det_checksum != ext4_dirblock_csum(inode, bh->b_data,
380 (char *)t - bh->b_data))
381 return 0;
382
383 return 1;
384}
385
386static void ext4_dirblock_csum_set(struct inode *inode,
387 struct buffer_head *bh)
388{
389 struct ext4_dir_entry_tail *t;
390
391 if (!ext4_has_metadata_csum(inode->i_sb))
392 return;
393
394 t = get_dirent_tail(inode, bh);
395 if (!t) {
396 warn_no_space_for_csum(inode);
397 return;
398 }
399
400 t->det_checksum = ext4_dirblock_csum(inode, bh->b_data,
401 (char *)t - bh->b_data);
402}
403
404int ext4_handle_dirty_dirblock(handle_t *handle,
405 struct inode *inode,
406 struct buffer_head *bh)
407{
408 ext4_dirblock_csum_set(inode, bh);
409 return ext4_handle_dirty_metadata(handle, inode, bh);
410}
411
412static struct dx_countlimit *get_dx_countlimit(struct inode *inode,
413 struct ext4_dir_entry *dirent,
414 int *offset)
415{
416 struct ext4_dir_entry *dp;
417 struct dx_root_info *root;
418 int count_offset;
419
420 if (le16_to_cpu(dirent->rec_len) == EXT4_BLOCK_SIZE(inode->i_sb))
421 count_offset = 8;
422 else if (le16_to_cpu(dirent->rec_len) == 12) {
423 dp = (struct ext4_dir_entry *)(((void *)dirent) + 12);
424 if (le16_to_cpu(dp->rec_len) !=
425 EXT4_BLOCK_SIZE(inode->i_sb) - 12)
426 return NULL;
427 root = (struct dx_root_info *)(((void *)dp + 12));
428 if (root->reserved_zero ||
429 root->info_length != sizeof(struct dx_root_info))
430 return NULL;
431 count_offset = 32;
432 } else
433 return NULL;
434
435 if (offset)
436 *offset = count_offset;
437 return (struct dx_countlimit *)(((void *)dirent) + count_offset);
438}
439
440static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent,
441 int count_offset, int count, struct dx_tail *t)
442{
443 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
444 struct ext4_inode_info *ei = EXT4_I(inode);
445 __u32 csum;
446 int size;
447 __u32 dummy_csum = 0;
448 int offset = offsetof(struct dx_tail, dt_checksum);
449
450 size = count_offset + (count * sizeof(struct dx_entry));
451 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
452 csum = ext4_chksum(sbi, csum, (__u8 *)t, offset);
453 csum = ext4_chksum(sbi, csum, (__u8 *)&dummy_csum, sizeof(dummy_csum));
454
455 return cpu_to_le32(csum);
456}
457
458static int ext4_dx_csum_verify(struct inode *inode,
459 struct ext4_dir_entry *dirent)
460{
461 struct dx_countlimit *c;
462 struct dx_tail *t;
463 int count_offset, limit, count;
464
465 if (!ext4_has_metadata_csum(inode->i_sb))
466 return 1;
467
468 c = get_dx_countlimit(inode, dirent, &count_offset);
469 if (!c) {
470 EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D.");
471 return 0;
472 }
473 limit = le16_to_cpu(c->limit);
474 count = le16_to_cpu(c->count);
475 if (count_offset + (limit * sizeof(struct dx_entry)) >
476 EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
477 warn_no_space_for_csum(inode);
478 return 0;
479 }
480 t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
481
482 if (t->dt_checksum != ext4_dx_csum(inode, dirent, count_offset,
483 count, t))
484 return 0;
485 return 1;
486}
487
488static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent)
489{
490 struct dx_countlimit *c;
491 struct dx_tail *t;
492 int count_offset, limit, count;
493
494 if (!ext4_has_metadata_csum(inode->i_sb))
495 return;
496
497 c = get_dx_countlimit(inode, dirent, &count_offset);
498 if (!c) {
499 EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D.");
500 return;
501 }
502 limit = le16_to_cpu(c->limit);
503 count = le16_to_cpu(c->count);
504 if (count_offset + (limit * sizeof(struct dx_entry)) >
505 EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
506 warn_no_space_for_csum(inode);
507 return;
508 }
509 t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
510
511 t->dt_checksum = ext4_dx_csum(inode, dirent, count_offset, count, t);
512}
513
514static inline int ext4_handle_dirty_dx_node(handle_t *handle,
515 struct inode *inode,
516 struct buffer_head *bh)
517{
518 ext4_dx_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
519 return ext4_handle_dirty_metadata(handle, inode, bh);
520}
521
522/*
523 * p is at least 6 bytes before the end of page
524 */
525static inline struct ext4_dir_entry_2 *
526ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
527{
528 return (struct ext4_dir_entry_2 *)((char *)p +
529 ext4_rec_len_from_disk(p->rec_len, blocksize));
530}
531
532/*
533 * Future: use high four bits of block for coalesce-on-delete flags
534 * Mask them off for now.
535 */
536
537static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
538{
539 return le32_to_cpu(entry->block) & 0x0fffffff;
540}
541
542static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
543{
544 entry->block = cpu_to_le32(value);
545}
546
547static inline unsigned dx_get_hash(struct dx_entry *entry)
548{
549 return le32_to_cpu(entry->hash);
550}
551
552static inline void dx_set_hash(struct dx_entry *entry, unsigned value)
553{
554 entry->hash = cpu_to_le32(value);
555}
556
557static inline unsigned dx_get_count(struct dx_entry *entries)
558{
559 return le16_to_cpu(((struct dx_countlimit *) entries)->count);
560}
561
562static inline unsigned dx_get_limit(struct dx_entry *entries)
563{
564 return le16_to_cpu(((struct dx_countlimit *) entries)->limit);
565}
566
567static inline void dx_set_count(struct dx_entry *entries, unsigned value)
568{
569 ((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
570}
571
572static inline void dx_set_limit(struct dx_entry *entries, unsigned value)
573{
574 ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
575}
576
577static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
578{
579 unsigned int entry_space = dir->i_sb->s_blocksize -
580 ext4_dir_rec_len(1, NULL) -
581 ext4_dir_rec_len(2, NULL) - infosize;
582
583 if (ext4_has_metadata_csum(dir->i_sb))
584 entry_space -= sizeof(struct dx_tail);
585 return entry_space / sizeof(struct dx_entry);
586}
587
588static inline unsigned dx_node_limit(struct inode *dir)
589{
590 unsigned int entry_space = dir->i_sb->s_blocksize -
591 ext4_dir_rec_len(0, dir);
592
593 if (ext4_has_metadata_csum(dir->i_sb))
594 entry_space -= sizeof(struct dx_tail);
595 return entry_space / sizeof(struct dx_entry);
596}
597
598/*
599 * Debug
600 */
601#ifdef DX_DEBUG
602static void dx_show_index(char * label, struct dx_entry *entries)
603{
604 int i, n = dx_get_count (entries);
605 printk(KERN_DEBUG "%s index", label);
606 for (i = 0; i < n; i++) {
607 printk(KERN_CONT " %x->%lu",
608 i ? dx_get_hash(entries + i) : 0,
609 (unsigned long)dx_get_block(entries + i));
610 }
611 printk(KERN_CONT "\n");
612}
613
614struct stats
615{
616 unsigned names;
617 unsigned space;
618 unsigned bcount;
619};
620
621static struct stats dx_show_leaf(struct inode *dir,
622 struct dx_hash_info *hinfo,
623 struct ext4_dir_entry_2 *de,
624 int size, int show_names)
625{
626 unsigned names = 0, space = 0;
627 char *base = (char *) de;
628 struct dx_hash_info h = *hinfo;
629
630 printk("names: ");
631 while ((char *) de < base + size)
632 {
633 if (de->inode)
634 {
635 if (show_names)
636 {
637#ifdef CONFIG_FS_ENCRYPTION
638 int len;
639 char *name;
640 struct fscrypt_str fname_crypto_str =
641 FSTR_INIT(NULL, 0);
642 int res = 0;
643
644 name = de->name;
645 len = de->name_len;
646 if (!IS_ENCRYPTED(dir)) {
647 /* Directory is not encrypted */
648 ext4fs_dirhash(dir, de->name,
649 de->name_len, &h);
650 printk("%*.s:(U)%x.%u ", len,
651 name, h.hash,
652 (unsigned) ((char *) de
653 - base));
654 } else {
655 struct fscrypt_str de_name =
656 FSTR_INIT(name, len);
657
658 /* Directory is encrypted */
659 res = fscrypt_fname_alloc_buffer(
660 len, &fname_crypto_str);
661 if (res)
662 printk(KERN_WARNING "Error "
663 "allocating crypto "
664 "buffer--skipping "
665 "crypto\n");
666 res = fscrypt_fname_disk_to_usr(dir,
667 0, 0, &de_name,
668 &fname_crypto_str);
669 if (res) {
670 printk(KERN_WARNING "Error "
671 "converting filename "
672 "from disk to usr"
673 "\n");
674 name = "??";
675 len = 2;
676 } else {
677 name = fname_crypto_str.name;
678 len = fname_crypto_str.len;
679 }
680 if (IS_CASEFOLDED(dir))
681 h.hash = EXT4_DIRENT_HASH(de);
682 else
683 ext4fs_dirhash(dir, de->name,
684 de->name_len, &h);
685 printk("%*.s:(E)%x.%u ", len, name,
686 h.hash, (unsigned) ((char *) de
687 - base));
688 fscrypt_fname_free_buffer(
689 &fname_crypto_str);
690 }
691#else
692 int len = de->name_len;
693 char *name = de->name;
694 ext4fs_dirhash(dir, de->name, de->name_len, &h);
695 printk("%*.s:%x.%u ", len, name, h.hash,
696 (unsigned) ((char *) de - base));
697#endif
698 }
699 space += ext4_dir_rec_len(de->name_len, dir);
700 names++;
701 }
702 de = ext4_next_entry(de, size);
703 }
704 printk(KERN_CONT "(%i)\n", names);
705 return (struct stats) { names, space, 1 };
706}
707
708struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
709 struct dx_entry *entries, int levels)
710{
711 unsigned blocksize = dir->i_sb->s_blocksize;
712 unsigned count = dx_get_count(entries), names = 0, space = 0, i;
713 unsigned bcount = 0;
714 struct buffer_head *bh;
715 printk("%i indexed blocks...\n", count);
716 for (i = 0; i < count; i++, entries++)
717 {
718 ext4_lblk_t block = dx_get_block(entries);
719 ext4_lblk_t hash = i ? dx_get_hash(entries): 0;
720 u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
721 struct stats stats;
722 printk("%s%3u:%03u hash %8x/%8x ",levels?"":" ", i, block, hash, range);
723 bh = ext4_bread(NULL,dir, block, 0);
724 if (!bh || IS_ERR(bh))
725 continue;
726 stats = levels?
727 dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
728 dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *)
729 bh->b_data, blocksize, 0);
730 names += stats.names;
731 space += stats.space;
732 bcount += stats.bcount;
733 brelse(bh);
734 }
735 if (bcount)
736 printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n",
737 levels ? "" : " ", names, space/bcount,
738 (space/bcount)*100/blocksize);
739 return (struct stats) { names, space, bcount};
740}
741
742/*
743 * Linear search cross check
744 */
745static inline void htree_rep_invariant_check(struct dx_entry *at,
746 struct dx_entry *target,
747 u32 hash, unsigned int n)
748{
749 while (n--) {
750 dxtrace(printk(KERN_CONT ","));
751 if (dx_get_hash(++at) > hash) {
752 at--;
753 break;
754 }
755 }
756 ASSERT(at == target - 1);
757}
758#else /* DX_DEBUG */
759static inline void htree_rep_invariant_check(struct dx_entry *at,
760 struct dx_entry *target,
761 u32 hash, unsigned int n)
762{
763}
764#endif /* DX_DEBUG */
765
766/*
767 * Probe for a directory leaf block to search.
768 *
769 * dx_probe can return ERR_BAD_DX_DIR, which means there was a format
770 * error in the directory index, and the caller should fall back to
771 * searching the directory normally. The callers of dx_probe **MUST**
772 * check for this error code, and make sure it never gets reflected
773 * back to userspace.
774 */
775static struct dx_frame *
776dx_probe(struct ext4_filename *fname, struct inode *dir,
777 struct dx_hash_info *hinfo, struct dx_frame *frame_in)
778{
779 unsigned count, indirect;
780 struct dx_entry *at, *entries, *p, *q, *m;
781 struct dx_root *root;
782 struct dx_frame *frame = frame_in;
783 struct dx_frame *ret_err = ERR_PTR(ERR_BAD_DX_DIR);
784 u32 hash;
785
786 memset(frame_in, 0, EXT4_HTREE_LEVEL * sizeof(frame_in[0]));
787 frame->bh = ext4_read_dirblock(dir, 0, INDEX);
788 if (IS_ERR(frame->bh))
789 return (struct dx_frame *) frame->bh;
790
791 root = (struct dx_root *) frame->bh->b_data;
792 if (root->info.hash_version != DX_HASH_TEA &&
793 root->info.hash_version != DX_HASH_HALF_MD4 &&
794 root->info.hash_version != DX_HASH_LEGACY &&
795 root->info.hash_version != DX_HASH_SIPHASH) {
796 ext4_warning_inode(dir, "Unrecognised inode hash code %u",
797 root->info.hash_version);
798 goto fail;
799 }
800 if (ext4_hash_in_dirent(dir)) {
801 if (root->info.hash_version != DX_HASH_SIPHASH) {
802 ext4_warning_inode(dir,
803 "Hash in dirent, but hash is not SIPHASH");
804 goto fail;
805 }
806 } else {
807 if (root->info.hash_version == DX_HASH_SIPHASH) {
808 ext4_warning_inode(dir,
809 "Hash code is SIPHASH, but hash not in dirent");
810 goto fail;
811 }
812 }
813 if (fname)
814 hinfo = &fname->hinfo;
815 hinfo->hash_version = root->info.hash_version;
816 if (hinfo->hash_version <= DX_HASH_TEA)
817 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
818 hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
819 /* hash is already computed for encrypted casefolded directory */
820 if (fname && fname_name(fname) &&
821 !(IS_ENCRYPTED(dir) && IS_CASEFOLDED(dir)))
822 ext4fs_dirhash(dir, fname_name(fname), fname_len(fname), hinfo);
823 hash = hinfo->hash;
824
825 if (root->info.unused_flags & 1) {
826 ext4_warning_inode(dir, "Unimplemented hash flags: %#06x",
827 root->info.unused_flags);
828 goto fail;
829 }
830
831 indirect = root->info.indirect_levels;
832 if (indirect >= ext4_dir_htree_level(dir->i_sb)) {
833 ext4_warning(dir->i_sb,
834 "Directory (ino: %lu) htree depth %#06x exceed"
835 "supported value", dir->i_ino,
836 ext4_dir_htree_level(dir->i_sb));
837 if (ext4_dir_htree_level(dir->i_sb) < EXT4_HTREE_LEVEL) {
838 ext4_warning(dir->i_sb, "Enable large directory "
839 "feature to access it");
840 }
841 goto fail;
842 }
843
844 entries = (struct dx_entry *)(((char *)&root->info) +
845 root->info.info_length);
846
847 if (dx_get_limit(entries) != dx_root_limit(dir,
848 root->info.info_length)) {
849 ext4_warning_inode(dir, "dx entry: limit %u != root limit %u",
850 dx_get_limit(entries),
851 dx_root_limit(dir, root->info.info_length));
852 goto fail;
853 }
854
855 dxtrace(printk("Look up %x", hash));
856 while (1) {
857 count = dx_get_count(entries);
858 if (!count || count > dx_get_limit(entries)) {
859 ext4_warning_inode(dir,
860 "dx entry: count %u beyond limit %u",
861 count, dx_get_limit(entries));
862 goto fail;
863 }
864
865 p = entries + 1;
866 q = entries + count - 1;
867 while (p <= q) {
868 m = p + (q - p) / 2;
869 dxtrace(printk(KERN_CONT "."));
870 if (dx_get_hash(m) > hash)
871 q = m - 1;
872 else
873 p = m + 1;
874 }
875
876 htree_rep_invariant_check(entries, p, hash, count - 1);
877
878 at = p - 1;
879 dxtrace(printk(KERN_CONT " %x->%u\n",
880 at == entries ? 0 : dx_get_hash(at),
881 dx_get_block(at)));
882 frame->entries = entries;
883 frame->at = at;
884 if (!indirect--)
885 return frame;
886 frame++;
887 frame->bh = ext4_read_dirblock(dir, dx_get_block(at), INDEX);
888 if (IS_ERR(frame->bh)) {
889 ret_err = (struct dx_frame *) frame->bh;
890 frame->bh = NULL;
891 goto fail;
892 }
893 entries = ((struct dx_node *) frame->bh->b_data)->entries;
894
895 if (dx_get_limit(entries) != dx_node_limit(dir)) {
896 ext4_warning_inode(dir,
897 "dx entry: limit %u != node limit %u",
898 dx_get_limit(entries), dx_node_limit(dir));
899 goto fail;
900 }
901 }
902fail:
903 while (frame >= frame_in) {
904 brelse(frame->bh);
905 frame--;
906 }
907
908 if (ret_err == ERR_PTR(ERR_BAD_DX_DIR))
909 ext4_warning_inode(dir,
910 "Corrupt directory, running e2fsck is recommended");
911 return ret_err;
912}
913
914static void dx_release(struct dx_frame *frames)
915{
916 struct dx_root_info *info;
917 int i;
918 unsigned int indirect_levels;
919
920 if (frames[0].bh == NULL)
921 return;
922
923 info = &((struct dx_root *)frames[0].bh->b_data)->info;
924 /* save local copy, "info" may be freed after brelse() */
925 indirect_levels = info->indirect_levels;
926 for (i = 0; i <= indirect_levels; i++) {
927 if (frames[i].bh == NULL)
928 break;
929 brelse(frames[i].bh);
930 frames[i].bh = NULL;
931 }
932}
933
934/*
935 * This function increments the frame pointer to search the next leaf
936 * block, and reads in the necessary intervening nodes if the search
937 * should be necessary. Whether or not the search is necessary is
938 * controlled by the hash parameter. If the hash value is even, then
939 * the search is only continued if the next block starts with that
940 * hash value. This is used if we are searching for a specific file.
941 *
942 * If the hash value is HASH_NB_ALWAYS, then always go to the next block.
943 *
944 * This function returns 1 if the caller should continue to search,
945 * or 0 if it should not. If there is an error reading one of the
946 * index blocks, it will a negative error code.
947 *
948 * If start_hash is non-null, it will be filled in with the starting
949 * hash of the next page.
950 */
951static int ext4_htree_next_block(struct inode *dir, __u32 hash,
952 struct dx_frame *frame,
953 struct dx_frame *frames,
954 __u32 *start_hash)
955{
956 struct dx_frame *p;
957 struct buffer_head *bh;
958 int num_frames = 0;
959 __u32 bhash;
960
961 p = frame;
962 /*
963 * Find the next leaf page by incrementing the frame pointer.
964 * If we run out of entries in the interior node, loop around and
965 * increment pointer in the parent node. When we break out of
966 * this loop, num_frames indicates the number of interior
967 * nodes need to be read.
968 */
969 while (1) {
970 if (++(p->at) < p->entries + dx_get_count(p->entries))
971 break;
972 if (p == frames)
973 return 0;
974 num_frames++;
975 p--;
976 }
977
978 /*
979 * If the hash is 1, then continue only if the next page has a
980 * continuation hash of any value. This is used for readdir
981 * handling. Otherwise, check to see if the hash matches the
982 * desired continuation hash. If it doesn't, return since
983 * there's no point to read in the successive index pages.
984 */
985 bhash = dx_get_hash(p->at);
986 if (start_hash)
987 *start_hash = bhash;
988 if ((hash & 1) == 0) {
989 if ((bhash & ~1) != hash)
990 return 0;
991 }
992 /*
993 * If the hash is HASH_NB_ALWAYS, we always go to the next
994 * block so no check is necessary
995 */
996 while (num_frames--) {
997 bh = ext4_read_dirblock(dir, dx_get_block(p->at), INDEX);
998 if (IS_ERR(bh))
999 return PTR_ERR(bh);
1000 p++;
1001 brelse(p->bh);
1002 p->bh = bh;
1003 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
1004 }
1005 return 1;
1006}
1007
1008
1009/*
1010 * This function fills a red-black tree with information from a
1011 * directory block. It returns the number directory entries loaded
1012 * into the tree. If there is an error it is returned in err.
1013 */
1014static int htree_dirblock_to_tree(struct file *dir_file,
1015 struct inode *dir, ext4_lblk_t block,
1016 struct dx_hash_info *hinfo,
1017 __u32 start_hash, __u32 start_minor_hash)
1018{
1019 struct buffer_head *bh;
1020 struct ext4_dir_entry_2 *de, *top;
1021 int err = 0, count = 0;
1022 struct fscrypt_str fname_crypto_str = FSTR_INIT(NULL, 0), tmp_str;
1023 int csum = ext4_has_metadata_csum(dir->i_sb);
1024
1025 dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
1026 (unsigned long)block));
1027 bh = ext4_read_dirblock(dir, block, DIRENT_HTREE);
1028 if (IS_ERR(bh))
1029 return PTR_ERR(bh);
1030
1031 de = (struct ext4_dir_entry_2 *) bh->b_data;
1032 /* csum entries are not larger in the casefolded encrypted case */
1033 top = (struct ext4_dir_entry_2 *) ((char *) de +
1034 dir->i_sb->s_blocksize -
1035 ext4_dir_rec_len(0,
1036 csum ? NULL : dir));
1037 /* Check if the directory is encrypted */
1038 if (IS_ENCRYPTED(dir)) {
1039 err = fscrypt_prepare_readdir(dir);
1040 if (err < 0) {
1041 brelse(bh);
1042 return err;
1043 }
1044 err = fscrypt_fname_alloc_buffer(EXT4_NAME_LEN,
1045 &fname_crypto_str);
1046 if (err < 0) {
1047 brelse(bh);
1048 return err;
1049 }
1050 }
1051
1052 for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) {
1053 if (ext4_check_dir_entry(dir, NULL, de, bh,
1054 bh->b_data, bh->b_size,
1055 (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
1056 + ((char *)de - bh->b_data))) {
1057 /* silently ignore the rest of the block */
1058 break;
1059 }
1060 if (ext4_hash_in_dirent(dir)) {
1061 if (de->name_len && de->inode) {
1062 hinfo->hash = EXT4_DIRENT_HASH(de);
1063 hinfo->minor_hash = EXT4_DIRENT_MINOR_HASH(de);
1064 } else {
1065 hinfo->hash = 0;
1066 hinfo->minor_hash = 0;
1067 }
1068 } else {
1069 ext4fs_dirhash(dir, de->name, de->name_len, hinfo);
1070 }
1071 if ((hinfo->hash < start_hash) ||
1072 ((hinfo->hash == start_hash) &&
1073 (hinfo->minor_hash < start_minor_hash)))
1074 continue;
1075 if (de->inode == 0)
1076 continue;
1077 if (!IS_ENCRYPTED(dir)) {
1078 tmp_str.name = de->name;
1079 tmp_str.len = de->name_len;
1080 err = ext4_htree_store_dirent(dir_file,
1081 hinfo->hash, hinfo->minor_hash, de,
1082 &tmp_str);
1083 } else {
1084 int save_len = fname_crypto_str.len;
1085 struct fscrypt_str de_name = FSTR_INIT(de->name,
1086 de->name_len);
1087
1088 /* Directory is encrypted */
1089 err = fscrypt_fname_disk_to_usr(dir, hinfo->hash,
1090 hinfo->minor_hash, &de_name,
1091 &fname_crypto_str);
1092 if (err) {
1093 count = err;
1094 goto errout;
1095 }
1096 err = ext4_htree_store_dirent(dir_file,
1097 hinfo->hash, hinfo->minor_hash, de,
1098 &fname_crypto_str);
1099 fname_crypto_str.len = save_len;
1100 }
1101 if (err != 0) {
1102 count = err;
1103 goto errout;
1104 }
1105 count++;
1106 }
1107errout:
1108 brelse(bh);
1109 fscrypt_fname_free_buffer(&fname_crypto_str);
1110 return count;
1111}
1112
1113
1114/*
1115 * This function fills a red-black tree with information from a
1116 * directory. We start scanning the directory in hash order, starting
1117 * at start_hash and start_minor_hash.
1118 *
1119 * This function returns the number of entries inserted into the tree,
1120 * or a negative error code.
1121 */
1122int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
1123 __u32 start_minor_hash, __u32 *next_hash)
1124{
1125 struct dx_hash_info hinfo;
1126 struct ext4_dir_entry_2 *de;
1127 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
1128 struct inode *dir;
1129 ext4_lblk_t block;
1130 int count = 0;
1131 int ret, err;
1132 __u32 hashval;
1133 struct fscrypt_str tmp_str;
1134
1135 dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
1136 start_hash, start_minor_hash));
1137 dir = file_inode(dir_file);
1138 if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) {
1139 if (ext4_hash_in_dirent(dir))
1140 hinfo.hash_version = DX_HASH_SIPHASH;
1141 else
1142 hinfo.hash_version =
1143 EXT4_SB(dir->i_sb)->s_def_hash_version;
1144 if (hinfo.hash_version <= DX_HASH_TEA)
1145 hinfo.hash_version +=
1146 EXT4_SB(dir->i_sb)->s_hash_unsigned;
1147 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
1148 if (ext4_has_inline_data(dir)) {
1149 int has_inline_data = 1;
1150 count = ext4_inlinedir_to_tree(dir_file, dir, 0,
1151 &hinfo, start_hash,
1152 start_minor_hash,
1153 &has_inline_data);
1154 if (has_inline_data) {
1155 *next_hash = ~0;
1156 return count;
1157 }
1158 }
1159 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
1160 start_hash, start_minor_hash);
1161 *next_hash = ~0;
1162 return count;
1163 }
1164 hinfo.hash = start_hash;
1165 hinfo.minor_hash = 0;
1166 frame = dx_probe(NULL, dir, &hinfo, frames);
1167 if (IS_ERR(frame))
1168 return PTR_ERR(frame);
1169
1170 /* Add '.' and '..' from the htree header */
1171 if (!start_hash && !start_minor_hash) {
1172 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
1173 tmp_str.name = de->name;
1174 tmp_str.len = de->name_len;
1175 err = ext4_htree_store_dirent(dir_file, 0, 0,
1176 de, &tmp_str);
1177 if (err != 0)
1178 goto errout;
1179 count++;
1180 }
1181 if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
1182 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
1183 de = ext4_next_entry(de, dir->i_sb->s_blocksize);
1184 tmp_str.name = de->name;
1185 tmp_str.len = de->name_len;
1186 err = ext4_htree_store_dirent(dir_file, 2, 0,
1187 de, &tmp_str);
1188 if (err != 0)
1189 goto errout;
1190 count++;
1191 }
1192
1193 while (1) {
1194 if (fatal_signal_pending(current)) {
1195 err = -ERESTARTSYS;
1196 goto errout;
1197 }
1198 cond_resched();
1199 block = dx_get_block(frame->at);
1200 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
1201 start_hash, start_minor_hash);
1202 if (ret < 0) {
1203 err = ret;
1204 goto errout;
1205 }
1206 count += ret;
1207 hashval = ~0;
1208 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
1209 frame, frames, &hashval);
1210 *next_hash = hashval;
1211 if (ret < 0) {
1212 err = ret;
1213 goto errout;
1214 }
1215 /*
1216 * Stop if: (a) there are no more entries, or
1217 * (b) we have inserted at least one entry and the
1218 * next hash value is not a continuation
1219 */
1220 if ((ret == 0) ||
1221 (count && ((hashval & 1) == 0)))
1222 break;
1223 }
1224 dx_release(frames);
1225 dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, "
1226 "next hash: %x\n", count, *next_hash));
1227 return count;
1228errout:
1229 dx_release(frames);
1230 return (err);
1231}
1232
1233static inline int search_dirblock(struct buffer_head *bh,
1234 struct inode *dir,
1235 struct ext4_filename *fname,
1236 unsigned int offset,
1237 struct ext4_dir_entry_2 **res_dir)
1238{
1239 return ext4_search_dir(bh, bh->b_data, dir->i_sb->s_blocksize, dir,
1240 fname, offset, res_dir);
1241}
1242
1243/*
1244 * Directory block splitting, compacting
1245 */
1246
1247/*
1248 * Create map of hash values, offsets, and sizes, stored at end of block.
1249 * Returns number of entries mapped.
1250 */
1251static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de,
1252 unsigned blocksize, struct dx_hash_info *hinfo,
1253 struct dx_map_entry *map_tail)
1254{
1255 int count = 0;
1256 char *base = (char *) de;
1257 struct dx_hash_info h = *hinfo;
1258
1259 while ((char *) de < base + blocksize) {
1260 if (de->name_len && de->inode) {
1261 if (ext4_hash_in_dirent(dir))
1262 h.hash = EXT4_DIRENT_HASH(de);
1263 else
1264 ext4fs_dirhash(dir, de->name, de->name_len, &h);
1265 map_tail--;
1266 map_tail->hash = h.hash;
1267 map_tail->offs = ((char *) de - base)>>2;
1268 map_tail->size = le16_to_cpu(de->rec_len);
1269 count++;
1270 cond_resched();
1271 }
1272 /* XXX: do we need to check rec_len == 0 case? -Chris */
1273 de = ext4_next_entry(de, blocksize);
1274 }
1275 return count;
1276}
1277
1278/* Sort map by hash value */
1279static void dx_sort_map (struct dx_map_entry *map, unsigned count)
1280{
1281 struct dx_map_entry *p, *q, *top = map + count - 1;
1282 int more;
1283 /* Combsort until bubble sort doesn't suck */
1284 while (count > 2) {
1285 count = count*10/13;
1286 if (count - 9 < 2) /* 9, 10 -> 11 */
1287 count = 11;
1288 for (p = top, q = p - count; q >= map; p--, q--)
1289 if (p->hash < q->hash)
1290 swap(*p, *q);
1291 }
1292 /* Garden variety bubble sort */
1293 do {
1294 more = 0;
1295 q = top;
1296 while (q-- > map) {
1297 if (q[1].hash >= q[0].hash)
1298 continue;
1299 swap(*(q+1), *q);
1300 more = 1;
1301 }
1302 } while(more);
1303}
1304
1305static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
1306{
1307 struct dx_entry *entries = frame->entries;
1308 struct dx_entry *old = frame->at, *new = old + 1;
1309 int count = dx_get_count(entries);
1310
1311 ASSERT(count < dx_get_limit(entries));
1312 ASSERT(old < entries + count);
1313 memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
1314 dx_set_hash(new, hash);
1315 dx_set_block(new, block);
1316 dx_set_count(entries, count + 1);
1317}
1318
1319#ifdef CONFIG_UNICODE
1320/*
1321 * Test whether a case-insensitive directory entry matches the filename
1322 * being searched for. If quick is set, assume the name being looked up
1323 * is already in the casefolded form.
1324 *
1325 * Returns: 0 if the directory entry matches, more than 0 if it
1326 * doesn't match or less than zero on error.
1327 */
1328static int ext4_ci_compare(const struct inode *parent, const struct qstr *name,
1329 u8 *de_name, size_t de_name_len, bool quick)
1330{
1331 const struct super_block *sb = parent->i_sb;
1332 const struct unicode_map *um = sb->s_encoding;
1333 struct fscrypt_str decrypted_name = FSTR_INIT(NULL, de_name_len);
1334 struct qstr entry = QSTR_INIT(de_name, de_name_len);
1335 int ret;
1336
1337 if (IS_ENCRYPTED(parent)) {
1338 const struct fscrypt_str encrypted_name =
1339 FSTR_INIT(de_name, de_name_len);
1340
1341 decrypted_name.name = kmalloc(de_name_len, GFP_KERNEL);
1342 if (!decrypted_name.name)
1343 return -ENOMEM;
1344 ret = fscrypt_fname_disk_to_usr(parent, 0, 0, &encrypted_name,
1345 &decrypted_name);
1346 if (ret < 0)
1347 goto out;
1348 entry.name = decrypted_name.name;
1349 entry.len = decrypted_name.len;
1350 }
1351
1352 if (quick)
1353 ret = utf8_strncasecmp_folded(um, name, &entry);
1354 else
1355 ret = utf8_strncasecmp(um, name, &entry);
1356 if (ret < 0) {
1357 /* Handle invalid character sequence as either an error
1358 * or as an opaque byte sequence.
1359 */
1360 if (sb_has_strict_encoding(sb))
1361 ret = -EINVAL;
1362 else if (name->len != entry.len)
1363 ret = 1;
1364 else
1365 ret = !!memcmp(name->name, entry.name, entry.len);
1366 }
1367out:
1368 kfree(decrypted_name.name);
1369 return ret;
1370}
1371
1372int ext4_fname_setup_ci_filename(struct inode *dir, const struct qstr *iname,
1373 struct ext4_filename *name)
1374{
1375 struct fscrypt_str *cf_name = &name->cf_name;
1376 struct dx_hash_info *hinfo = &name->hinfo;
1377 int len;
1378
1379 if (!IS_CASEFOLDED(dir) || !dir->i_sb->s_encoding ||
1380 (IS_ENCRYPTED(dir) && !fscrypt_has_encryption_key(dir))) {
1381 cf_name->name = NULL;
1382 return 0;
1383 }
1384
1385 cf_name->name = kmalloc(EXT4_NAME_LEN, GFP_NOFS);
1386 if (!cf_name->name)
1387 return -ENOMEM;
1388
1389 len = utf8_casefold(dir->i_sb->s_encoding,
1390 iname, cf_name->name,
1391 EXT4_NAME_LEN);
1392 if (len <= 0) {
1393 kfree(cf_name->name);
1394 cf_name->name = NULL;
1395 }
1396 cf_name->len = (unsigned) len;
1397 if (!IS_ENCRYPTED(dir))
1398 return 0;
1399
1400 hinfo->hash_version = DX_HASH_SIPHASH;
1401 hinfo->seed = NULL;
1402 if (cf_name->name)
1403 ext4fs_dirhash(dir, cf_name->name, cf_name->len, hinfo);
1404 else
1405 ext4fs_dirhash(dir, iname->name, iname->len, hinfo);
1406 return 0;
1407}
1408#endif
1409
1410/*
1411 * Test whether a directory entry matches the filename being searched for.
1412 *
1413 * Return: %true if the directory entry matches, otherwise %false.
1414 */
1415static bool ext4_match(struct inode *parent,
1416 const struct ext4_filename *fname,
1417 struct ext4_dir_entry_2 *de)
1418{
1419 struct fscrypt_name f;
1420
1421 if (!de->inode)
1422 return false;
1423
1424 f.usr_fname = fname->usr_fname;
1425 f.disk_name = fname->disk_name;
1426#ifdef CONFIG_FS_ENCRYPTION
1427 f.crypto_buf = fname->crypto_buf;
1428#endif
1429
1430#ifdef CONFIG_UNICODE
1431 if (parent->i_sb->s_encoding && IS_CASEFOLDED(parent) &&
1432 (!IS_ENCRYPTED(parent) || fscrypt_has_encryption_key(parent))) {
1433 if (fname->cf_name.name) {
1434 struct qstr cf = {.name = fname->cf_name.name,
1435 .len = fname->cf_name.len};
1436 if (IS_ENCRYPTED(parent)) {
1437 if (fname->hinfo.hash != EXT4_DIRENT_HASH(de) ||
1438 fname->hinfo.minor_hash !=
1439 EXT4_DIRENT_MINOR_HASH(de)) {
1440
1441 return 0;
1442 }
1443 }
1444 return !ext4_ci_compare(parent, &cf, de->name,
1445 de->name_len, true);
1446 }
1447 return !ext4_ci_compare(parent, fname->usr_fname, de->name,
1448 de->name_len, false);
1449 }
1450#endif
1451
1452 return fscrypt_match_name(&f, de->name, de->name_len);
1453}
1454
1455/*
1456 * Returns 0 if not found, -1 on failure, and 1 on success
1457 */
1458int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size,
1459 struct inode *dir, struct ext4_filename *fname,
1460 unsigned int offset, struct ext4_dir_entry_2 **res_dir)
1461{
1462 struct ext4_dir_entry_2 * de;
1463 char * dlimit;
1464 int de_len;
1465
1466 de = (struct ext4_dir_entry_2 *)search_buf;
1467 dlimit = search_buf + buf_size;
1468 while ((char *) de < dlimit) {
1469 /* this code is executed quadratically often */
1470 /* do minimal checking `by hand' */
1471 if ((char *) de + de->name_len <= dlimit &&
1472 ext4_match(dir, fname, de)) {
1473 /* found a match - just to be sure, do
1474 * a full check */
1475 if (ext4_check_dir_entry(dir, NULL, de, bh, search_buf,
1476 buf_size, offset))
1477 return -1;
1478 *res_dir = de;
1479 return 1;
1480 }
1481 /* prevent looping on a bad block */
1482 de_len = ext4_rec_len_from_disk(de->rec_len,
1483 dir->i_sb->s_blocksize);
1484 if (de_len <= 0)
1485 return -1;
1486 offset += de_len;
1487 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
1488 }
1489 return 0;
1490}
1491
1492static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block,
1493 struct ext4_dir_entry *de)
1494{
1495 struct super_block *sb = dir->i_sb;
1496
1497 if (!is_dx(dir))
1498 return 0;
1499 if (block == 0)
1500 return 1;
1501 if (de->inode == 0 &&
1502 ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) ==
1503 sb->s_blocksize)
1504 return 1;
1505 return 0;
1506}
1507
1508/*
1509 * __ext4_find_entry()
1510 *
1511 * finds an entry in the specified directory with the wanted name. It
1512 * returns the cache buffer in which the entry was found, and the entry
1513 * itself (as a parameter - res_dir). It does NOT read the inode of the
1514 * entry - you'll have to do that yourself if you want to.
1515 *
1516 * The returned buffer_head has ->b_count elevated. The caller is expected
1517 * to brelse() it when appropriate.
1518 */
1519static struct buffer_head *__ext4_find_entry(struct inode *dir,
1520 struct ext4_filename *fname,
1521 struct ext4_dir_entry_2 **res_dir,
1522 int *inlined)
1523{
1524 struct super_block *sb;
1525 struct buffer_head *bh_use[NAMEI_RA_SIZE];
1526 struct buffer_head *bh, *ret = NULL;
1527 ext4_lblk_t start, block;
1528 const u8 *name = fname->usr_fname->name;
1529 size_t ra_max = 0; /* Number of bh's in the readahead
1530 buffer, bh_use[] */
1531 size_t ra_ptr = 0; /* Current index into readahead
1532 buffer */
1533 ext4_lblk_t nblocks;
1534 int i, namelen, retval;
1535
1536 *res_dir = NULL;
1537 sb = dir->i_sb;
1538 namelen = fname->usr_fname->len;
1539 if (namelen > EXT4_NAME_LEN)
1540 return NULL;
1541
1542 if (ext4_has_inline_data(dir)) {
1543 int has_inline_data = 1;
1544 ret = ext4_find_inline_entry(dir, fname, res_dir,
1545 &has_inline_data);
1546 if (has_inline_data) {
1547 if (inlined)
1548 *inlined = 1;
1549 goto cleanup_and_exit;
1550 }
1551 }
1552
1553 if ((namelen <= 2) && (name[0] == '.') &&
1554 (name[1] == '.' || name[1] == '\0')) {
1555 /*
1556 * "." or ".." will only be in the first block
1557 * NFS may look up ".."; "." should be handled by the VFS
1558 */
1559 block = start = 0;
1560 nblocks = 1;
1561 goto restart;
1562 }
1563 if (is_dx(dir)) {
1564 ret = ext4_dx_find_entry(dir, fname, res_dir);
1565 /*
1566 * On success, or if the error was file not found,
1567 * return. Otherwise, fall back to doing a search the
1568 * old fashioned way.
1569 */
1570 if (!IS_ERR(ret) || PTR_ERR(ret) != ERR_BAD_DX_DIR)
1571 goto cleanup_and_exit;
1572 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
1573 "falling back\n"));
1574 ret = NULL;
1575 }
1576 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1577 if (!nblocks) {
1578 ret = NULL;
1579 goto cleanup_and_exit;
1580 }
1581 start = EXT4_I(dir)->i_dir_start_lookup;
1582 if (start >= nblocks)
1583 start = 0;
1584 block = start;
1585restart:
1586 do {
1587 /*
1588 * We deal with the read-ahead logic here.
1589 */
1590 cond_resched();
1591 if (ra_ptr >= ra_max) {
1592 /* Refill the readahead buffer */
1593 ra_ptr = 0;
1594 if (block < start)
1595 ra_max = start - block;
1596 else
1597 ra_max = nblocks - block;
1598 ra_max = min(ra_max, ARRAY_SIZE(bh_use));
1599 retval = ext4_bread_batch(dir, block, ra_max,
1600 false /* wait */, bh_use);
1601 if (retval) {
1602 ret = ERR_PTR(retval);
1603 ra_max = 0;
1604 goto cleanup_and_exit;
1605 }
1606 }
1607 if ((bh = bh_use[ra_ptr++]) == NULL)
1608 goto next;
1609 wait_on_buffer(bh);
1610 if (!buffer_uptodate(bh)) {
1611 EXT4_ERROR_INODE_ERR(dir, EIO,
1612 "reading directory lblock %lu",
1613 (unsigned long) block);
1614 brelse(bh);
1615 ret = ERR_PTR(-EIO);
1616 goto cleanup_and_exit;
1617 }
1618 if (!buffer_verified(bh) &&
1619 !is_dx_internal_node(dir, block,
1620 (struct ext4_dir_entry *)bh->b_data) &&
1621 !ext4_dirblock_csum_verify(dir, bh)) {
1622 EXT4_ERROR_INODE_ERR(dir, EFSBADCRC,
1623 "checksumming directory "
1624 "block %lu", (unsigned long)block);
1625 brelse(bh);
1626 ret = ERR_PTR(-EFSBADCRC);
1627 goto cleanup_and_exit;
1628 }
1629 set_buffer_verified(bh);
1630 i = search_dirblock(bh, dir, fname,
1631 block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
1632 if (i == 1) {
1633 EXT4_I(dir)->i_dir_start_lookup = block;
1634 ret = bh;
1635 goto cleanup_and_exit;
1636 } else {
1637 brelse(bh);
1638 if (i < 0)
1639 goto cleanup_and_exit;
1640 }
1641 next:
1642 if (++block >= nblocks)
1643 block = 0;
1644 } while (block != start);
1645
1646 /*
1647 * If the directory has grown while we were searching, then
1648 * search the last part of the directory before giving up.
1649 */
1650 block = nblocks;
1651 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1652 if (block < nblocks) {
1653 start = 0;
1654 goto restart;
1655 }
1656
1657cleanup_and_exit:
1658 /* Clean up the read-ahead blocks */
1659 for (; ra_ptr < ra_max; ra_ptr++)
1660 brelse(bh_use[ra_ptr]);
1661 return ret;
1662}
1663
1664static struct buffer_head *ext4_find_entry(struct inode *dir,
1665 const struct qstr *d_name,
1666 struct ext4_dir_entry_2 **res_dir,
1667 int *inlined)
1668{
1669 int err;
1670 struct ext4_filename fname;
1671 struct buffer_head *bh;
1672
1673 err = ext4_fname_setup_filename(dir, d_name, 1, &fname);
1674 if (err == -ENOENT)
1675 return NULL;
1676 if (err)
1677 return ERR_PTR(err);
1678
1679 bh = __ext4_find_entry(dir, &fname, res_dir, inlined);
1680
1681 ext4_fname_free_filename(&fname);
1682 return bh;
1683}
1684
1685static struct buffer_head *ext4_lookup_entry(struct inode *dir,
1686 struct dentry *dentry,
1687 struct ext4_dir_entry_2 **res_dir)
1688{
1689 int err;
1690 struct ext4_filename fname;
1691 struct buffer_head *bh;
1692
1693 err = ext4_fname_prepare_lookup(dir, dentry, &fname);
1694 generic_set_encrypted_ci_d_ops(dentry);
1695 if (err == -ENOENT)
1696 return NULL;
1697 if (err)
1698 return ERR_PTR(err);
1699
1700 bh = __ext4_find_entry(dir, &fname, res_dir, NULL);
1701
1702 ext4_fname_free_filename(&fname);
1703 return bh;
1704}
1705
1706static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
1707 struct ext4_filename *fname,
1708 struct ext4_dir_entry_2 **res_dir)
1709{
1710 struct super_block * sb = dir->i_sb;
1711 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
1712 struct buffer_head *bh;
1713 ext4_lblk_t block;
1714 int retval;
1715
1716#ifdef CONFIG_FS_ENCRYPTION
1717 *res_dir = NULL;
1718#endif
1719 frame = dx_probe(fname, dir, NULL, frames);
1720 if (IS_ERR(frame))
1721 return (struct buffer_head *) frame;
1722 do {
1723 block = dx_get_block(frame->at);
1724 bh = ext4_read_dirblock(dir, block, DIRENT_HTREE);
1725 if (IS_ERR(bh))
1726 goto errout;
1727
1728 retval = search_dirblock(bh, dir, fname,
1729 block << EXT4_BLOCK_SIZE_BITS(sb),
1730 res_dir);
1731 if (retval == 1)
1732 goto success;
1733 brelse(bh);
1734 if (retval == -1) {
1735 bh = ERR_PTR(ERR_BAD_DX_DIR);
1736 goto errout;
1737 }
1738
1739 /* Check to see if we should continue to search */
1740 retval = ext4_htree_next_block(dir, fname->hinfo.hash, frame,
1741 frames, NULL);
1742 if (retval < 0) {
1743 ext4_warning_inode(dir,
1744 "error %d reading directory index block",
1745 retval);
1746 bh = ERR_PTR(retval);
1747 goto errout;
1748 }
1749 } while (retval == 1);
1750
1751 bh = NULL;
1752errout:
1753 dxtrace(printk(KERN_DEBUG "%s not found\n", fname->usr_fname->name));
1754success:
1755 dx_release(frames);
1756 return bh;
1757}
1758
1759static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
1760{
1761 struct inode *inode;
1762 struct ext4_dir_entry_2 *de;
1763 struct buffer_head *bh;
1764
1765 if (dentry->d_name.len > EXT4_NAME_LEN)
1766 return ERR_PTR(-ENAMETOOLONG);
1767
1768 bh = ext4_lookup_entry(dir, dentry, &de);
1769 if (IS_ERR(bh))
1770 return ERR_CAST(bh);
1771 inode = NULL;
1772 if (bh) {
1773 __u32 ino = le32_to_cpu(de->inode);
1774 brelse(bh);
1775 if (!ext4_valid_inum(dir->i_sb, ino)) {
1776 EXT4_ERROR_INODE(dir, "bad inode number: %u", ino);
1777 return ERR_PTR(-EFSCORRUPTED);
1778 }
1779 if (unlikely(ino == dir->i_ino)) {
1780 EXT4_ERROR_INODE(dir, "'%pd' linked to parent dir",
1781 dentry);
1782 return ERR_PTR(-EFSCORRUPTED);
1783 }
1784 inode = ext4_iget(dir->i_sb, ino, EXT4_IGET_NORMAL);
1785 if (inode == ERR_PTR(-ESTALE)) {
1786 EXT4_ERROR_INODE(dir,
1787 "deleted inode referenced: %u",
1788 ino);
1789 return ERR_PTR(-EFSCORRUPTED);
1790 }
1791 if (!IS_ERR(inode) && IS_ENCRYPTED(dir) &&
1792 (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) &&
1793 !fscrypt_has_permitted_context(dir, inode)) {
1794 ext4_warning(inode->i_sb,
1795 "Inconsistent encryption contexts: %lu/%lu",
1796 dir->i_ino, inode->i_ino);
1797 iput(inode);
1798 return ERR_PTR(-EPERM);
1799 }
1800 }
1801
1802#ifdef CONFIG_UNICODE
1803 if (!inode && IS_CASEFOLDED(dir)) {
1804 /* Eventually we want to call d_add_ci(dentry, NULL)
1805 * for negative dentries in the encoding case as
1806 * well. For now, prevent the negative dentry
1807 * from being cached.
1808 */
1809 return NULL;
1810 }
1811#endif
1812 return d_splice_alias(inode, dentry);
1813}
1814
1815
1816struct dentry *ext4_get_parent(struct dentry *child)
1817{
1818 __u32 ino;
1819 struct ext4_dir_entry_2 * de;
1820 struct buffer_head *bh;
1821
1822 bh = ext4_find_entry(d_inode(child), &dotdot_name, &de, NULL);
1823 if (IS_ERR(bh))
1824 return ERR_CAST(bh);
1825 if (!bh)
1826 return ERR_PTR(-ENOENT);
1827 ino = le32_to_cpu(de->inode);
1828 brelse(bh);
1829
1830 if (!ext4_valid_inum(child->d_sb, ino)) {
1831 EXT4_ERROR_INODE(d_inode(child),
1832 "bad parent inode number: %u", ino);
1833 return ERR_PTR(-EFSCORRUPTED);
1834 }
1835
1836 return d_obtain_alias(ext4_iget(child->d_sb, ino, EXT4_IGET_NORMAL));
1837}
1838
1839/*
1840 * Move count entries from end of map between two memory locations.
1841 * Returns pointer to last entry moved.
1842 */
1843static struct ext4_dir_entry_2 *
1844dx_move_dirents(struct inode *dir, char *from, char *to,
1845 struct dx_map_entry *map, int count,
1846 unsigned blocksize)
1847{
1848 unsigned rec_len = 0;
1849
1850 while (count--) {
1851 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
1852 (from + (map->offs<<2));
1853 rec_len = ext4_dir_rec_len(de->name_len, dir);
1854
1855 memcpy (to, de, rec_len);
1856 ((struct ext4_dir_entry_2 *) to)->rec_len =
1857 ext4_rec_len_to_disk(rec_len, blocksize);
1858
1859 /* wipe dir_entry excluding the rec_len field */
1860 de->inode = 0;
1861 memset(&de->name_len, 0, ext4_rec_len_from_disk(de->rec_len,
1862 blocksize) -
1863 offsetof(struct ext4_dir_entry_2,
1864 name_len));
1865
1866 map++;
1867 to += rec_len;
1868 }
1869 return (struct ext4_dir_entry_2 *) (to - rec_len);
1870}
1871
1872/*
1873 * Compact each dir entry in the range to the minimal rec_len.
1874 * Returns pointer to last entry in range.
1875 */
1876static struct ext4_dir_entry_2 *dx_pack_dirents(struct inode *dir, char *base,
1877 unsigned int blocksize)
1878{
1879 struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
1880 unsigned rec_len = 0;
1881
1882 prev = to = de;
1883 while ((char*)de < base + blocksize) {
1884 next = ext4_next_entry(de, blocksize);
1885 if (de->inode && de->name_len) {
1886 rec_len = ext4_dir_rec_len(de->name_len, dir);
1887 if (de > to)
1888 memmove(to, de, rec_len);
1889 to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
1890 prev = to;
1891 to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
1892 }
1893 de = next;
1894 }
1895 return prev;
1896}
1897
1898/*
1899 * Split a full leaf block to make room for a new dir entry.
1900 * Allocate a new block, and move entries so that they are approx. equally full.
1901 * Returns pointer to de in block into which the new entry will be inserted.
1902 */
1903static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
1904 struct buffer_head **bh,struct dx_frame *frame,
1905 struct dx_hash_info *hinfo)
1906{
1907 unsigned blocksize = dir->i_sb->s_blocksize;
1908 unsigned count, continued;
1909 struct buffer_head *bh2;
1910 ext4_lblk_t newblock;
1911 u32 hash2;
1912 struct dx_map_entry *map;
1913 char *data1 = (*bh)->b_data, *data2;
1914 unsigned split, move, size;
1915 struct ext4_dir_entry_2 *de = NULL, *de2;
1916 int csum_size = 0;
1917 int err = 0, i;
1918
1919 if (ext4_has_metadata_csum(dir->i_sb))
1920 csum_size = sizeof(struct ext4_dir_entry_tail);
1921
1922 bh2 = ext4_append(handle, dir, &newblock);
1923 if (IS_ERR(bh2)) {
1924 brelse(*bh);
1925 *bh = NULL;
1926 return (struct ext4_dir_entry_2 *) bh2;
1927 }
1928
1929 BUFFER_TRACE(*bh, "get_write_access");
1930 err = ext4_journal_get_write_access(handle, *bh);
1931 if (err)
1932 goto journal_error;
1933
1934 BUFFER_TRACE(frame->bh, "get_write_access");
1935 err = ext4_journal_get_write_access(handle, frame->bh);
1936 if (err)
1937 goto journal_error;
1938
1939 data2 = bh2->b_data;
1940
1941 /* create map in the end of data2 block */
1942 map = (struct dx_map_entry *) (data2 + blocksize);
1943 count = dx_make_map(dir, (struct ext4_dir_entry_2 *) data1,
1944 blocksize, hinfo, map);
1945 map -= count;
1946 dx_sort_map(map, count);
1947 /* Ensure that neither split block is over half full */
1948 size = 0;
1949 move = 0;
1950 for (i = count-1; i >= 0; i--) {
1951 /* is more than half of this entry in 2nd half of the block? */
1952 if (size + map[i].size/2 > blocksize/2)
1953 break;
1954 size += map[i].size;
1955 move++;
1956 }
1957 /*
1958 * map index at which we will split
1959 *
1960 * If the sum of active entries didn't exceed half the block size, just
1961 * split it in half by count; each resulting block will have at least
1962 * half the space free.
1963 */
1964 if (i > 0)
1965 split = count - move;
1966 else
1967 split = count/2;
1968
1969 hash2 = map[split].hash;
1970 continued = hash2 == map[split - 1].hash;
1971 dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
1972 (unsigned long)dx_get_block(frame->at),
1973 hash2, split, count-split));
1974
1975 /* Fancy dance to stay within two buffers */
1976 de2 = dx_move_dirents(dir, data1, data2, map + split, count - split,
1977 blocksize);
1978 de = dx_pack_dirents(dir, data1, blocksize);
1979 de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
1980 (char *) de,
1981 blocksize);
1982 de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
1983 (char *) de2,
1984 blocksize);
1985 if (csum_size) {
1986 ext4_initialize_dirent_tail(*bh, blocksize);
1987 ext4_initialize_dirent_tail(bh2, blocksize);
1988 }
1989
1990 dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data1,
1991 blocksize, 1));
1992 dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data2,
1993 blocksize, 1));
1994
1995 /* Which block gets the new entry? */
1996 if (hinfo->hash >= hash2) {
1997 swap(*bh, bh2);
1998 de = de2;
1999 }
2000 dx_insert_block(frame, hash2 + continued, newblock);
2001 err = ext4_handle_dirty_dirblock(handle, dir, bh2);
2002 if (err)
2003 goto journal_error;
2004 err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
2005 if (err)
2006 goto journal_error;
2007 brelse(bh2);
2008 dxtrace(dx_show_index("frame", frame->entries));
2009 return de;
2010
2011journal_error:
2012 brelse(*bh);
2013 brelse(bh2);
2014 *bh = NULL;
2015 ext4_std_error(dir->i_sb, err);
2016 return ERR_PTR(err);
2017}
2018
2019int ext4_find_dest_de(struct inode *dir, struct inode *inode,
2020 struct buffer_head *bh,
2021 void *buf, int buf_size,
2022 struct ext4_filename *fname,
2023 struct ext4_dir_entry_2 **dest_de)
2024{
2025 struct ext4_dir_entry_2 *de;
2026 unsigned short reclen = ext4_dir_rec_len(fname_len(fname), dir);
2027 int nlen, rlen;
2028 unsigned int offset = 0;
2029 char *top;
2030
2031 de = (struct ext4_dir_entry_2 *)buf;
2032 top = buf + buf_size - reclen;
2033 while ((char *) de <= top) {
2034 if (ext4_check_dir_entry(dir, NULL, de, bh,
2035 buf, buf_size, offset))
2036 return -EFSCORRUPTED;
2037 if (ext4_match(dir, fname, de))
2038 return -EEXIST;
2039 nlen = ext4_dir_rec_len(de->name_len, dir);
2040 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
2041 if ((de->inode ? rlen - nlen : rlen) >= reclen)
2042 break;
2043 de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
2044 offset += rlen;
2045 }
2046 if ((char *) de > top)
2047 return -ENOSPC;
2048
2049 *dest_de = de;
2050 return 0;
2051}
2052
2053void ext4_insert_dentry(struct inode *dir,
2054 struct inode *inode,
2055 struct ext4_dir_entry_2 *de,
2056 int buf_size,
2057 struct ext4_filename *fname)
2058{
2059
2060 int nlen, rlen;
2061
2062 nlen = ext4_dir_rec_len(de->name_len, dir);
2063 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
2064 if (de->inode) {
2065 struct ext4_dir_entry_2 *de1 =
2066 (struct ext4_dir_entry_2 *)((char *)de + nlen);
2067 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, buf_size);
2068 de->rec_len = ext4_rec_len_to_disk(nlen, buf_size);
2069 de = de1;
2070 }
2071 de->file_type = EXT4_FT_UNKNOWN;
2072 de->inode = cpu_to_le32(inode->i_ino);
2073 ext4_set_de_type(inode->i_sb, de, inode->i_mode);
2074 de->name_len = fname_len(fname);
2075 memcpy(de->name, fname_name(fname), fname_len(fname));
2076 if (ext4_hash_in_dirent(dir)) {
2077 struct dx_hash_info *hinfo = &fname->hinfo;
2078
2079 EXT4_DIRENT_HASHES(de)->hash = cpu_to_le32(hinfo->hash);
2080 EXT4_DIRENT_HASHES(de)->minor_hash =
2081 cpu_to_le32(hinfo->minor_hash);
2082 }
2083}
2084
2085/*
2086 * Add a new entry into a directory (leaf) block. If de is non-NULL,
2087 * it points to a directory entry which is guaranteed to be large
2088 * enough for new directory entry. If de is NULL, then
2089 * add_dirent_to_buf will attempt search the directory block for
2090 * space. It will return -ENOSPC if no space is available, and -EIO
2091 * and -EEXIST if directory entry already exists.
2092 */
2093static int add_dirent_to_buf(handle_t *handle, struct ext4_filename *fname,
2094 struct inode *dir,
2095 struct inode *inode, struct ext4_dir_entry_2 *de,
2096 struct buffer_head *bh)
2097{
2098 unsigned int blocksize = dir->i_sb->s_blocksize;
2099 int csum_size = 0;
2100 int err, err2;
2101
2102 if (ext4_has_metadata_csum(inode->i_sb))
2103 csum_size = sizeof(struct ext4_dir_entry_tail);
2104
2105 if (!de) {
2106 err = ext4_find_dest_de(dir, inode, bh, bh->b_data,
2107 blocksize - csum_size, fname, &de);
2108 if (err)
2109 return err;
2110 }
2111 BUFFER_TRACE(bh, "get_write_access");
2112 err = ext4_journal_get_write_access(handle, bh);
2113 if (err) {
2114 ext4_std_error(dir->i_sb, err);
2115 return err;
2116 }
2117
2118 /* By now the buffer is marked for journaling */
2119 ext4_insert_dentry(dir, inode, de, blocksize, fname);
2120
2121 /*
2122 * XXX shouldn't update any times until successful
2123 * completion of syscall, but too many callers depend
2124 * on this.
2125 *
2126 * XXX similarly, too many callers depend on
2127 * ext4_new_inode() setting the times, but error
2128 * recovery deletes the inode, so the worst that can
2129 * happen is that the times are slightly out of date
2130 * and/or different from the directory change time.
2131 */
2132 dir->i_mtime = dir->i_ctime = current_time(dir);
2133 ext4_update_dx_flag(dir);
2134 inode_inc_iversion(dir);
2135 err2 = ext4_mark_inode_dirty(handle, dir);
2136 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
2137 err = ext4_handle_dirty_dirblock(handle, dir, bh);
2138 if (err)
2139 ext4_std_error(dir->i_sb, err);
2140 return err ? err : err2;
2141}
2142
2143/*
2144 * This converts a one block unindexed directory to a 3 block indexed
2145 * directory, and adds the dentry to the indexed directory.
2146 */
2147static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname,
2148 struct inode *dir,
2149 struct inode *inode, struct buffer_head *bh)
2150{
2151 struct buffer_head *bh2;
2152 struct dx_root *root;
2153 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
2154 struct dx_entry *entries;
2155 struct ext4_dir_entry_2 *de, *de2;
2156 char *data2, *top;
2157 unsigned len;
2158 int retval;
2159 unsigned blocksize;
2160 ext4_lblk_t block;
2161 struct fake_dirent *fde;
2162 int csum_size = 0;
2163
2164 if (ext4_has_metadata_csum(inode->i_sb))
2165 csum_size = sizeof(struct ext4_dir_entry_tail);
2166
2167 blocksize = dir->i_sb->s_blocksize;
2168 dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
2169 BUFFER_TRACE(bh, "get_write_access");
2170 retval = ext4_journal_get_write_access(handle, bh);
2171 if (retval) {
2172 ext4_std_error(dir->i_sb, retval);
2173 brelse(bh);
2174 return retval;
2175 }
2176 root = (struct dx_root *) bh->b_data;
2177
2178 /* The 0th block becomes the root, move the dirents out */
2179 fde = &root->dotdot;
2180 de = (struct ext4_dir_entry_2 *)((char *)fde +
2181 ext4_rec_len_from_disk(fde->rec_len, blocksize));
2182 if ((char *) de >= (((char *) root) + blocksize)) {
2183 EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
2184 brelse(bh);
2185 return -EFSCORRUPTED;
2186 }
2187 len = ((char *) root) + (blocksize - csum_size) - (char *) de;
2188
2189 /* Allocate new block for the 0th block's dirents */
2190 bh2 = ext4_append(handle, dir, &block);
2191 if (IS_ERR(bh2)) {
2192 brelse(bh);
2193 return PTR_ERR(bh2);
2194 }
2195 ext4_set_inode_flag(dir, EXT4_INODE_INDEX);
2196 data2 = bh2->b_data;
2197
2198 memcpy(data2, de, len);
2199 memset(de, 0, len); /* wipe old data */
2200 de = (struct ext4_dir_entry_2 *) data2;
2201 top = data2 + len;
2202 while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
2203 de = de2;
2204 de->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
2205 (char *) de, blocksize);
2206
2207 if (csum_size)
2208 ext4_initialize_dirent_tail(bh2, blocksize);
2209
2210 /* Initialize the root; the dot dirents already exist */
2211 de = (struct ext4_dir_entry_2 *) (&root->dotdot);
2212 de->rec_len = ext4_rec_len_to_disk(
2213 blocksize - ext4_dir_rec_len(2, NULL), blocksize);
2214 memset (&root->info, 0, sizeof(root->info));
2215 root->info.info_length = sizeof(root->info);
2216 if (ext4_hash_in_dirent(dir))
2217 root->info.hash_version = DX_HASH_SIPHASH;
2218 else
2219 root->info.hash_version =
2220 EXT4_SB(dir->i_sb)->s_def_hash_version;
2221
2222 entries = root->entries;
2223 dx_set_block(entries, 1);
2224 dx_set_count(entries, 1);
2225 dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
2226
2227 /* Initialize as for dx_probe */
2228 fname->hinfo.hash_version = root->info.hash_version;
2229 if (fname->hinfo.hash_version <= DX_HASH_TEA)
2230 fname->hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
2231 fname->hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
2232
2233 /* casefolded encrypted hashes are computed on fname setup */
2234 if (!ext4_hash_in_dirent(dir))
2235 ext4fs_dirhash(dir, fname_name(fname),
2236 fname_len(fname), &fname->hinfo);
2237
2238 memset(frames, 0, sizeof(frames));
2239 frame = frames;
2240 frame->entries = entries;
2241 frame->at = entries;
2242 frame->bh = bh;
2243
2244 retval = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
2245 if (retval)
2246 goto out_frames;
2247 retval = ext4_handle_dirty_dirblock(handle, dir, bh2);
2248 if (retval)
2249 goto out_frames;
2250
2251 de = do_split(handle,dir, &bh2, frame, &fname->hinfo);
2252 if (IS_ERR(de)) {
2253 retval = PTR_ERR(de);
2254 goto out_frames;
2255 }
2256
2257 retval = add_dirent_to_buf(handle, fname, dir, inode, de, bh2);
2258out_frames:
2259 /*
2260 * Even if the block split failed, we have to properly write
2261 * out all the changes we did so far. Otherwise we can end up
2262 * with corrupted filesystem.
2263 */
2264 if (retval)
2265 ext4_mark_inode_dirty(handle, dir);
2266 dx_release(frames);
2267 brelse(bh2);
2268 return retval;
2269}
2270
2271/*
2272 * ext4_add_entry()
2273 *
2274 * adds a file entry to the specified directory, using the same
2275 * semantics as ext4_find_entry(). It returns NULL if it failed.
2276 *
2277 * NOTE!! The inode part of 'de' is left at 0 - which means you
2278 * may not sleep between calling this and putting something into
2279 * the entry, as someone else might have used it while you slept.
2280 */
2281static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
2282 struct inode *inode)
2283{
2284 struct inode *dir = d_inode(dentry->d_parent);
2285 struct buffer_head *bh = NULL;
2286 struct ext4_dir_entry_2 *de;
2287 struct super_block *sb;
2288 struct ext4_filename fname;
2289 int retval;
2290 int dx_fallback=0;
2291 unsigned blocksize;
2292 ext4_lblk_t block, blocks;
2293 int csum_size = 0;
2294
2295 if (ext4_has_metadata_csum(inode->i_sb))
2296 csum_size = sizeof(struct ext4_dir_entry_tail);
2297
2298 sb = dir->i_sb;
2299 blocksize = sb->s_blocksize;
2300 if (!dentry->d_name.len)
2301 return -EINVAL;
2302
2303 if (fscrypt_is_nokey_name(dentry))
2304 return -ENOKEY;
2305
2306#ifdef CONFIG_UNICODE
2307 if (sb_has_strict_encoding(sb) && IS_CASEFOLDED(dir) &&
2308 sb->s_encoding && utf8_validate(sb->s_encoding, &dentry->d_name))
2309 return -EINVAL;
2310#endif
2311
2312 retval = ext4_fname_setup_filename(dir, &dentry->d_name, 0, &fname);
2313 if (retval)
2314 return retval;
2315
2316 if (ext4_has_inline_data(dir)) {
2317 retval = ext4_try_add_inline_entry(handle, &fname, dir, inode);
2318 if (retval < 0)
2319 goto out;
2320 if (retval == 1) {
2321 retval = 0;
2322 goto out;
2323 }
2324 }
2325
2326 if (is_dx(dir)) {
2327 retval = ext4_dx_add_entry(handle, &fname, dir, inode);
2328 if (!retval || (retval != ERR_BAD_DX_DIR))
2329 goto out;
2330 /* Can we just ignore htree data? */
2331 if (ext4_has_metadata_csum(sb)) {
2332 EXT4_ERROR_INODE(dir,
2333 "Directory has corrupted htree index.");
2334 retval = -EFSCORRUPTED;
2335 goto out;
2336 }
2337 ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
2338 dx_fallback++;
2339 retval = ext4_mark_inode_dirty(handle, dir);
2340 if (unlikely(retval))
2341 goto out;
2342 }
2343 blocks = dir->i_size >> sb->s_blocksize_bits;
2344 for (block = 0; block < blocks; block++) {
2345 bh = ext4_read_dirblock(dir, block, DIRENT);
2346 if (bh == NULL) {
2347 bh = ext4_bread(handle, dir, block,
2348 EXT4_GET_BLOCKS_CREATE);
2349 goto add_to_new_block;
2350 }
2351 if (IS_ERR(bh)) {
2352 retval = PTR_ERR(bh);
2353 bh = NULL;
2354 goto out;
2355 }
2356 retval = add_dirent_to_buf(handle, &fname, dir, inode,
2357 NULL, bh);
2358 if (retval != -ENOSPC)
2359 goto out;
2360
2361 if (blocks == 1 && !dx_fallback &&
2362 ext4_has_feature_dir_index(sb)) {
2363 retval = make_indexed_dir(handle, &fname, dir,
2364 inode, bh);
2365 bh = NULL; /* make_indexed_dir releases bh */
2366 goto out;
2367 }
2368 brelse(bh);
2369 }
2370 bh = ext4_append(handle, dir, &block);
2371add_to_new_block:
2372 if (IS_ERR(bh)) {
2373 retval = PTR_ERR(bh);
2374 bh = NULL;
2375 goto out;
2376 }
2377 de = (struct ext4_dir_entry_2 *) bh->b_data;
2378 de->inode = 0;
2379 de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize);
2380
2381 if (csum_size)
2382 ext4_initialize_dirent_tail(bh, blocksize);
2383
2384 retval = add_dirent_to_buf(handle, &fname, dir, inode, de, bh);
2385out:
2386 ext4_fname_free_filename(&fname);
2387 brelse(bh);
2388 if (retval == 0)
2389 ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY);
2390 return retval;
2391}
2392
2393/*
2394 * Returns 0 for success, or a negative error value
2395 */
2396static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
2397 struct inode *dir, struct inode *inode)
2398{
2399 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
2400 struct dx_entry *entries, *at;
2401 struct buffer_head *bh;
2402 struct super_block *sb = dir->i_sb;
2403 struct ext4_dir_entry_2 *de;
2404 int restart;
2405 int err;
2406
2407again:
2408 restart = 0;
2409 frame = dx_probe(fname, dir, NULL, frames);
2410 if (IS_ERR(frame))
2411 return PTR_ERR(frame);
2412 entries = frame->entries;
2413 at = frame->at;
2414 bh = ext4_read_dirblock(dir, dx_get_block(frame->at), DIRENT_HTREE);
2415 if (IS_ERR(bh)) {
2416 err = PTR_ERR(bh);
2417 bh = NULL;
2418 goto cleanup;
2419 }
2420
2421 BUFFER_TRACE(bh, "get_write_access");
2422 err = ext4_journal_get_write_access(handle, bh);
2423 if (err)
2424 goto journal_error;
2425
2426 err = add_dirent_to_buf(handle, fname, dir, inode, NULL, bh);
2427 if (err != -ENOSPC)
2428 goto cleanup;
2429
2430 err = 0;
2431 /* Block full, should compress but for now just split */
2432 dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
2433 dx_get_count(entries), dx_get_limit(entries)));
2434 /* Need to split index? */
2435 if (dx_get_count(entries) == dx_get_limit(entries)) {
2436 ext4_lblk_t newblock;
2437 int levels = frame - frames + 1;
2438 unsigned int icount;
2439 int add_level = 1;
2440 struct dx_entry *entries2;
2441 struct dx_node *node2;
2442 struct buffer_head *bh2;
2443
2444 while (frame > frames) {
2445 if (dx_get_count((frame - 1)->entries) <
2446 dx_get_limit((frame - 1)->entries)) {
2447 add_level = 0;
2448 break;
2449 }
2450 frame--; /* split higher index block */
2451 at = frame->at;
2452 entries = frame->entries;
2453 restart = 1;
2454 }
2455 if (add_level && levels == ext4_dir_htree_level(sb)) {
2456 ext4_warning(sb, "Directory (ino: %lu) index full, "
2457 "reach max htree level :%d",
2458 dir->i_ino, levels);
2459 if (ext4_dir_htree_level(sb) < EXT4_HTREE_LEVEL) {
2460 ext4_warning(sb, "Large directory feature is "
2461 "not enabled on this "
2462 "filesystem");
2463 }
2464 err = -ENOSPC;
2465 goto cleanup;
2466 }
2467 icount = dx_get_count(entries);
2468 bh2 = ext4_append(handle, dir, &newblock);
2469 if (IS_ERR(bh2)) {
2470 err = PTR_ERR(bh2);
2471 goto cleanup;
2472 }
2473 node2 = (struct dx_node *)(bh2->b_data);
2474 entries2 = node2->entries;
2475 memset(&node2->fake, 0, sizeof(struct fake_dirent));
2476 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
2477 sb->s_blocksize);
2478 BUFFER_TRACE(frame->bh, "get_write_access");
2479 err = ext4_journal_get_write_access(handle, frame->bh);
2480 if (err)
2481 goto journal_error;
2482 if (!add_level) {
2483 unsigned icount1 = icount/2, icount2 = icount - icount1;
2484 unsigned hash2 = dx_get_hash(entries + icount1);
2485 dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
2486 icount1, icount2));
2487
2488 BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
2489 err = ext4_journal_get_write_access(handle,
2490 (frame - 1)->bh);
2491 if (err)
2492 goto journal_error;
2493
2494 memcpy((char *) entries2, (char *) (entries + icount1),
2495 icount2 * sizeof(struct dx_entry));
2496 dx_set_count(entries, icount1);
2497 dx_set_count(entries2, icount2);
2498 dx_set_limit(entries2, dx_node_limit(dir));
2499
2500 /* Which index block gets the new entry? */
2501 if (at - entries >= icount1) {
2502 frame->at = at - entries - icount1 + entries2;
2503 frame->entries = entries = entries2;
2504 swap(frame->bh, bh2);
2505 }
2506 dx_insert_block((frame - 1), hash2, newblock);
2507 dxtrace(dx_show_index("node", frame->entries));
2508 dxtrace(dx_show_index("node",
2509 ((struct dx_node *) bh2->b_data)->entries));
2510 err = ext4_handle_dirty_dx_node(handle, dir, bh2);
2511 if (err)
2512 goto journal_error;
2513 brelse (bh2);
2514 err = ext4_handle_dirty_dx_node(handle, dir,
2515 (frame - 1)->bh);
2516 if (err)
2517 goto journal_error;
2518 err = ext4_handle_dirty_dx_node(handle, dir,
2519 frame->bh);
2520 if (restart || err)
2521 goto journal_error;
2522 } else {
2523 struct dx_root *dxroot;
2524 memcpy((char *) entries2, (char *) entries,
2525 icount * sizeof(struct dx_entry));
2526 dx_set_limit(entries2, dx_node_limit(dir));
2527
2528 /* Set up root */
2529 dx_set_count(entries, 1);
2530 dx_set_block(entries + 0, newblock);
2531 dxroot = (struct dx_root *)frames[0].bh->b_data;
2532 dxroot->info.indirect_levels += 1;
2533 dxtrace(printk(KERN_DEBUG
2534 "Creating %d level index...\n",
2535 dxroot->info.indirect_levels));
2536 err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
2537 if (err)
2538 goto journal_error;
2539 err = ext4_handle_dirty_dx_node(handle, dir, bh2);
2540 brelse(bh2);
2541 restart = 1;
2542 goto journal_error;
2543 }
2544 }
2545 de = do_split(handle, dir, &bh, frame, &fname->hinfo);
2546 if (IS_ERR(de)) {
2547 err = PTR_ERR(de);
2548 goto cleanup;
2549 }
2550 err = add_dirent_to_buf(handle, fname, dir, inode, de, bh);
2551 goto cleanup;
2552
2553journal_error:
2554 ext4_std_error(dir->i_sb, err); /* this is a no-op if err == 0 */
2555cleanup:
2556 brelse(bh);
2557 dx_release(frames);
2558 /* @restart is true means htree-path has been changed, we need to
2559 * repeat dx_probe() to find out valid htree-path
2560 */
2561 if (restart && err == 0)
2562 goto again;
2563 return err;
2564}
2565
2566/*
2567 * ext4_generic_delete_entry deletes a directory entry by merging it
2568 * with the previous entry
2569 */
2570int ext4_generic_delete_entry(struct inode *dir,
2571 struct ext4_dir_entry_2 *de_del,
2572 struct buffer_head *bh,
2573 void *entry_buf,
2574 int buf_size,
2575 int csum_size)
2576{
2577 struct ext4_dir_entry_2 *de, *pde;
2578 unsigned int blocksize = dir->i_sb->s_blocksize;
2579 int i;
2580
2581 i = 0;
2582 pde = NULL;
2583 de = (struct ext4_dir_entry_2 *)entry_buf;
2584 while (i < buf_size - csum_size) {
2585 if (ext4_check_dir_entry(dir, NULL, de, bh,
2586 entry_buf, buf_size, i))
2587 return -EFSCORRUPTED;
2588 if (de == de_del) {
2589 if (pde) {
2590 pde->rec_len = ext4_rec_len_to_disk(
2591 ext4_rec_len_from_disk(pde->rec_len,
2592 blocksize) +
2593 ext4_rec_len_from_disk(de->rec_len,
2594 blocksize),
2595 blocksize);
2596
2597 /* wipe entire dir_entry */
2598 memset(de, 0, ext4_rec_len_from_disk(de->rec_len,
2599 blocksize));
2600 } else {
2601 /* wipe dir_entry excluding the rec_len field */
2602 de->inode = 0;
2603 memset(&de->name_len, 0,
2604 ext4_rec_len_from_disk(de->rec_len,
2605 blocksize) -
2606 offsetof(struct ext4_dir_entry_2,
2607 name_len));
2608 }
2609
2610 inode_inc_iversion(dir);
2611 return 0;
2612 }
2613 i += ext4_rec_len_from_disk(de->rec_len, blocksize);
2614 pde = de;
2615 de = ext4_next_entry(de, blocksize);
2616 }
2617 return -ENOENT;
2618}
2619
2620static int ext4_delete_entry(handle_t *handle,
2621 struct inode *dir,
2622 struct ext4_dir_entry_2 *de_del,
2623 struct buffer_head *bh)
2624{
2625 int err, csum_size = 0;
2626
2627 if (ext4_has_inline_data(dir)) {
2628 int has_inline_data = 1;
2629 err = ext4_delete_inline_entry(handle, dir, de_del, bh,
2630 &has_inline_data);
2631 if (has_inline_data)
2632 return err;
2633 }
2634
2635 if (ext4_has_metadata_csum(dir->i_sb))
2636 csum_size = sizeof(struct ext4_dir_entry_tail);
2637
2638 BUFFER_TRACE(bh, "get_write_access");
2639 err = ext4_journal_get_write_access(handle, bh);
2640 if (unlikely(err))
2641 goto out;
2642
2643 err = ext4_generic_delete_entry(dir, de_del, bh, bh->b_data,
2644 dir->i_sb->s_blocksize, csum_size);
2645 if (err)
2646 goto out;
2647
2648 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
2649 err = ext4_handle_dirty_dirblock(handle, dir, bh);
2650 if (unlikely(err))
2651 goto out;
2652
2653 return 0;
2654out:
2655 if (err != -ENOENT)
2656 ext4_std_error(dir->i_sb, err);
2657 return err;
2658}
2659
2660/*
2661 * Set directory link count to 1 if nlinks > EXT4_LINK_MAX, or if nlinks == 2
2662 * since this indicates that nlinks count was previously 1 to avoid overflowing
2663 * the 16-bit i_links_count field on disk. Directories with i_nlink == 1 mean
2664 * that subdirectory link counts are not being maintained accurately.
2665 *
2666 * The caller has already checked for i_nlink overflow in case the DIR_LINK
2667 * feature is not enabled and returned -EMLINK. The is_dx() check is a proxy
2668 * for checking S_ISDIR(inode) (since the INODE_INDEX feature will not be set
2669 * on regular files) and to avoid creating huge/slow non-HTREE directories.
2670 */
2671static void ext4_inc_count(struct inode *inode)
2672{
2673 inc_nlink(inode);
2674 if (is_dx(inode) &&
2675 (inode->i_nlink > EXT4_LINK_MAX || inode->i_nlink == 2))
2676 set_nlink(inode, 1);
2677}
2678
2679/*
2680 * If a directory had nlink == 1, then we should let it be 1. This indicates
2681 * directory has >EXT4_LINK_MAX subdirs.
2682 */
2683static void ext4_dec_count(struct inode *inode)
2684{
2685 if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
2686 drop_nlink(inode);
2687}
2688
2689
2690/*
2691 * Add non-directory inode to a directory. On success, the inode reference is
2692 * consumed by dentry is instantiation. This is also indicated by clearing of
2693 * *inodep pointer. On failure, the caller is responsible for dropping the
2694 * inode reference in the safe context.
2695 */
2696static int ext4_add_nondir(handle_t *handle,
2697 struct dentry *dentry, struct inode **inodep)
2698{
2699 struct inode *dir = d_inode(dentry->d_parent);
2700 struct inode *inode = *inodep;
2701 int err = ext4_add_entry(handle, dentry, inode);
2702 if (!err) {
2703 err = ext4_mark_inode_dirty(handle, inode);
2704 if (IS_DIRSYNC(dir))
2705 ext4_handle_sync(handle);
2706 d_instantiate_new(dentry, inode);
2707 *inodep = NULL;
2708 return err;
2709 }
2710 drop_nlink(inode);
2711 ext4_orphan_add(handle, inode);
2712 unlock_new_inode(inode);
2713 return err;
2714}
2715
2716/*
2717 * By the time this is called, we already have created
2718 * the directory cache entry for the new file, but it
2719 * is so far negative - it has no inode.
2720 *
2721 * If the create succeeds, we fill in the inode information
2722 * with d_instantiate().
2723 */
2724static int ext4_create(struct user_namespace *mnt_userns, struct inode *dir,
2725 struct dentry *dentry, umode_t mode, bool excl)
2726{
2727 handle_t *handle;
2728 struct inode *inode;
2729 int err, credits, retries = 0;
2730
2731 err = dquot_initialize(dir);
2732 if (err)
2733 return err;
2734
2735 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2736 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2737retry:
2738 inode = ext4_new_inode_start_handle(mnt_userns, dir, mode, &dentry->d_name,
2739 0, NULL, EXT4_HT_DIR, credits);
2740 handle = ext4_journal_current_handle();
2741 err = PTR_ERR(inode);
2742 if (!IS_ERR(inode)) {
2743 inode->i_op = &ext4_file_inode_operations;
2744 inode->i_fop = &ext4_file_operations;
2745 ext4_set_aops(inode);
2746 err = ext4_add_nondir(handle, dentry, &inode);
2747 if (!err)
2748 ext4_fc_track_create(handle, dentry);
2749 }
2750 if (handle)
2751 ext4_journal_stop(handle);
2752 if (!IS_ERR_OR_NULL(inode))
2753 iput(inode);
2754 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2755 goto retry;
2756 return err;
2757}
2758
2759static int ext4_mknod(struct user_namespace *mnt_userns, struct inode *dir,
2760 struct dentry *dentry, umode_t mode, dev_t rdev)
2761{
2762 handle_t *handle;
2763 struct inode *inode;
2764 int err, credits, retries = 0;
2765
2766 err = dquot_initialize(dir);
2767 if (err)
2768 return err;
2769
2770 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2771 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2772retry:
2773 inode = ext4_new_inode_start_handle(mnt_userns, dir, mode, &dentry->d_name,
2774 0, NULL, EXT4_HT_DIR, credits);
2775 handle = ext4_journal_current_handle();
2776 err = PTR_ERR(inode);
2777 if (!IS_ERR(inode)) {
2778 init_special_inode(inode, inode->i_mode, rdev);
2779 inode->i_op = &ext4_special_inode_operations;
2780 err = ext4_add_nondir(handle, dentry, &inode);
2781 if (!err)
2782 ext4_fc_track_create(handle, dentry);
2783 }
2784 if (handle)
2785 ext4_journal_stop(handle);
2786 if (!IS_ERR_OR_NULL(inode))
2787 iput(inode);
2788 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2789 goto retry;
2790 return err;
2791}
2792
2793static int ext4_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
2794 struct dentry *dentry, umode_t mode)
2795{
2796 handle_t *handle;
2797 struct inode *inode;
2798 int err, retries = 0;
2799
2800 err = dquot_initialize(dir);
2801 if (err)
2802 return err;
2803
2804retry:
2805 inode = ext4_new_inode_start_handle(mnt_userns, dir, mode,
2806 NULL, 0, NULL,
2807 EXT4_HT_DIR,
2808 EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
2809 4 + EXT4_XATTR_TRANS_BLOCKS);
2810 handle = ext4_journal_current_handle();
2811 err = PTR_ERR(inode);
2812 if (!IS_ERR(inode)) {
2813 inode->i_op = &ext4_file_inode_operations;
2814 inode->i_fop = &ext4_file_operations;
2815 ext4_set_aops(inode);
2816 d_tmpfile(dentry, inode);
2817 err = ext4_orphan_add(handle, inode);
2818 if (err)
2819 goto err_unlock_inode;
2820 mark_inode_dirty(inode);
2821 unlock_new_inode(inode);
2822 }
2823 if (handle)
2824 ext4_journal_stop(handle);
2825 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2826 goto retry;
2827 return err;
2828err_unlock_inode:
2829 ext4_journal_stop(handle);
2830 unlock_new_inode(inode);
2831 return err;
2832}
2833
2834struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
2835 struct ext4_dir_entry_2 *de,
2836 int blocksize, int csum_size,
2837 unsigned int parent_ino, int dotdot_real_len)
2838{
2839 de->inode = cpu_to_le32(inode->i_ino);
2840 de->name_len = 1;
2841 de->rec_len = ext4_rec_len_to_disk(ext4_dir_rec_len(de->name_len, NULL),
2842 blocksize);
2843 strcpy(de->name, ".");
2844 ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2845
2846 de = ext4_next_entry(de, blocksize);
2847 de->inode = cpu_to_le32(parent_ino);
2848 de->name_len = 2;
2849 if (!dotdot_real_len)
2850 de->rec_len = ext4_rec_len_to_disk(blocksize -
2851 (csum_size + ext4_dir_rec_len(1, NULL)),
2852 blocksize);
2853 else
2854 de->rec_len = ext4_rec_len_to_disk(
2855 ext4_dir_rec_len(de->name_len, NULL),
2856 blocksize);
2857 strcpy(de->name, "..");
2858 ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2859
2860 return ext4_next_entry(de, blocksize);
2861}
2862
2863int ext4_init_new_dir(handle_t *handle, struct inode *dir,
2864 struct inode *inode)
2865{
2866 struct buffer_head *dir_block = NULL;
2867 struct ext4_dir_entry_2 *de;
2868 ext4_lblk_t block = 0;
2869 unsigned int blocksize = dir->i_sb->s_blocksize;
2870 int csum_size = 0;
2871 int err;
2872
2873 if (ext4_has_metadata_csum(dir->i_sb))
2874 csum_size = sizeof(struct ext4_dir_entry_tail);
2875
2876 if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
2877 err = ext4_try_create_inline_dir(handle, dir, inode);
2878 if (err < 0 && err != -ENOSPC)
2879 goto out;
2880 if (!err)
2881 goto out;
2882 }
2883
2884 inode->i_size = 0;
2885 dir_block = ext4_append(handle, inode, &block);
2886 if (IS_ERR(dir_block))
2887 return PTR_ERR(dir_block);
2888 de = (struct ext4_dir_entry_2 *)dir_block->b_data;
2889 ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0);
2890 set_nlink(inode, 2);
2891 if (csum_size)
2892 ext4_initialize_dirent_tail(dir_block, blocksize);
2893
2894 BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
2895 err = ext4_handle_dirty_dirblock(handle, inode, dir_block);
2896 if (err)
2897 goto out;
2898 set_buffer_verified(dir_block);
2899out:
2900 brelse(dir_block);
2901 return err;
2902}
2903
2904static int ext4_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
2905 struct dentry *dentry, umode_t mode)
2906{
2907 handle_t *handle;
2908 struct inode *inode;
2909 int err, err2 = 0, credits, retries = 0;
2910
2911 if (EXT4_DIR_LINK_MAX(dir))
2912 return -EMLINK;
2913
2914 err = dquot_initialize(dir);
2915 if (err)
2916 return err;
2917
2918 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2919 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2920retry:
2921 inode = ext4_new_inode_start_handle(mnt_userns, dir, S_IFDIR | mode,
2922 &dentry->d_name,
2923 0, NULL, EXT4_HT_DIR, credits);
2924 handle = ext4_journal_current_handle();
2925 err = PTR_ERR(inode);
2926 if (IS_ERR(inode))
2927 goto out_stop;
2928
2929 inode->i_op = &ext4_dir_inode_operations;
2930 inode->i_fop = &ext4_dir_operations;
2931 err = ext4_init_new_dir(handle, dir, inode);
2932 if (err)
2933 goto out_clear_inode;
2934 err = ext4_mark_inode_dirty(handle, inode);
2935 if (!err)
2936 err = ext4_add_entry(handle, dentry, inode);
2937 if (err) {
2938out_clear_inode:
2939 clear_nlink(inode);
2940 ext4_orphan_add(handle, inode);
2941 unlock_new_inode(inode);
2942 err2 = ext4_mark_inode_dirty(handle, inode);
2943 if (unlikely(err2))
2944 err = err2;
2945 ext4_journal_stop(handle);
2946 iput(inode);
2947 goto out_retry;
2948 }
2949 ext4_inc_count(dir);
2950
2951 ext4_update_dx_flag(dir);
2952 err = ext4_mark_inode_dirty(handle, dir);
2953 if (err)
2954 goto out_clear_inode;
2955 d_instantiate_new(dentry, inode);
2956 ext4_fc_track_create(handle, dentry);
2957 if (IS_DIRSYNC(dir))
2958 ext4_handle_sync(handle);
2959
2960out_stop:
2961 if (handle)
2962 ext4_journal_stop(handle);
2963out_retry:
2964 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2965 goto retry;
2966 return err;
2967}
2968
2969/*
2970 * routine to check that the specified directory is empty (for rmdir)
2971 */
2972bool ext4_empty_dir(struct inode *inode)
2973{
2974 unsigned int offset;
2975 struct buffer_head *bh;
2976 struct ext4_dir_entry_2 *de;
2977 struct super_block *sb;
2978
2979 if (ext4_has_inline_data(inode)) {
2980 int has_inline_data = 1;
2981 int ret;
2982
2983 ret = empty_inline_dir(inode, &has_inline_data);
2984 if (has_inline_data)
2985 return ret;
2986 }
2987
2988 sb = inode->i_sb;
2989 if (inode->i_size < ext4_dir_rec_len(1, NULL) +
2990 ext4_dir_rec_len(2, NULL)) {
2991 EXT4_ERROR_INODE(inode, "invalid size");
2992 return true;
2993 }
2994 /* The first directory block must not be a hole,
2995 * so treat it as DIRENT_HTREE
2996 */
2997 bh = ext4_read_dirblock(inode, 0, DIRENT_HTREE);
2998 if (IS_ERR(bh))
2999 return true;
3000
3001 de = (struct ext4_dir_entry_2 *) bh->b_data;
3002 if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, bh->b_size,
3003 0) ||
3004 le32_to_cpu(de->inode) != inode->i_ino || strcmp(".", de->name)) {
3005 ext4_warning_inode(inode, "directory missing '.'");
3006 brelse(bh);
3007 return true;
3008 }
3009 offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
3010 de = ext4_next_entry(de, sb->s_blocksize);
3011 if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, bh->b_size,
3012 offset) ||
3013 le32_to_cpu(de->inode) == 0 || strcmp("..", de->name)) {
3014 ext4_warning_inode(inode, "directory missing '..'");
3015 brelse(bh);
3016 return true;
3017 }
3018 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
3019 while (offset < inode->i_size) {
3020 if (!(offset & (sb->s_blocksize - 1))) {
3021 unsigned int lblock;
3022 brelse(bh);
3023 lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb);
3024 bh = ext4_read_dirblock(inode, lblock, EITHER);
3025 if (bh == NULL) {
3026 offset += sb->s_blocksize;
3027 continue;
3028 }
3029 if (IS_ERR(bh))
3030 return true;
3031 }
3032 de = (struct ext4_dir_entry_2 *) (bh->b_data +
3033 (offset & (sb->s_blocksize - 1)));
3034 if (ext4_check_dir_entry(inode, NULL, de, bh,
3035 bh->b_data, bh->b_size, offset)) {
3036 offset = (offset | (sb->s_blocksize - 1)) + 1;
3037 continue;
3038 }
3039 if (le32_to_cpu(de->inode)) {
3040 brelse(bh);
3041 return false;
3042 }
3043 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
3044 }
3045 brelse(bh);
3046 return true;
3047}
3048
3049/*
3050 * ext4_orphan_add() links an unlinked or truncated inode into a list of
3051 * such inodes, starting at the superblock, in case we crash before the
3052 * file is closed/deleted, or in case the inode truncate spans multiple
3053 * transactions and the last transaction is not recovered after a crash.
3054 *
3055 * At filesystem recovery time, we walk this list deleting unlinked
3056 * inodes and truncating linked inodes in ext4_orphan_cleanup().
3057 *
3058 * Orphan list manipulation functions must be called under i_mutex unless
3059 * we are just creating the inode or deleting it.
3060 */
3061int ext4_orphan_add(handle_t *handle, struct inode *inode)
3062{
3063 struct super_block *sb = inode->i_sb;
3064 struct ext4_sb_info *sbi = EXT4_SB(sb);
3065 struct ext4_iloc iloc;
3066 int err = 0, rc;
3067 bool dirty = false;
3068
3069 if (!sbi->s_journal || is_bad_inode(inode))
3070 return 0;
3071
3072 WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
3073 !inode_is_locked(inode));
3074 /*
3075 * Exit early if inode already is on orphan list. This is a big speedup
3076 * since we don't have to contend on the global s_orphan_lock.
3077 */
3078 if (!list_empty(&EXT4_I(inode)->i_orphan))
3079 return 0;
3080
3081 /*
3082 * Orphan handling is only valid for files with data blocks
3083 * being truncated, or files being unlinked. Note that we either
3084 * hold i_mutex, or the inode can not be referenced from outside,
3085 * so i_nlink should not be bumped due to race
3086 */
3087 ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
3088 S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
3089
3090 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
3091 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
3092 if (err)
3093 goto out;
3094
3095 err = ext4_reserve_inode_write(handle, inode, &iloc);
3096 if (err)
3097 goto out;
3098
3099 mutex_lock(&sbi->s_orphan_lock);
3100 /*
3101 * Due to previous errors inode may be already a part of on-disk
3102 * orphan list. If so skip on-disk list modification.
3103 */
3104 if (!NEXT_ORPHAN(inode) || NEXT_ORPHAN(inode) >
3105 (le32_to_cpu(sbi->s_es->s_inodes_count))) {
3106 /* Insert this inode at the head of the on-disk orphan list */
3107 NEXT_ORPHAN(inode) = le32_to_cpu(sbi->s_es->s_last_orphan);
3108 lock_buffer(sbi->s_sbh);
3109 sbi->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
3110 ext4_superblock_csum_set(sb);
3111 unlock_buffer(sbi->s_sbh);
3112 dirty = true;
3113 }
3114 list_add(&EXT4_I(inode)->i_orphan, &sbi->s_orphan);
3115 mutex_unlock(&sbi->s_orphan_lock);
3116
3117 if (dirty) {
3118 err = ext4_handle_dirty_metadata(handle, NULL, sbi->s_sbh);
3119 rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
3120 if (!err)
3121 err = rc;
3122 if (err) {
3123 /*
3124 * We have to remove inode from in-memory list if
3125 * addition to on disk orphan list failed. Stray orphan
3126 * list entries can cause panics at unmount time.
3127 */
3128 mutex_lock(&sbi->s_orphan_lock);
3129 list_del_init(&EXT4_I(inode)->i_orphan);
3130 mutex_unlock(&sbi->s_orphan_lock);
3131 }
3132 } else
3133 brelse(iloc.bh);
3134
3135 jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
3136 jbd_debug(4, "orphan inode %lu will point to %d\n",
3137 inode->i_ino, NEXT_ORPHAN(inode));
3138out:
3139 ext4_std_error(sb, err);
3140 return err;
3141}
3142
3143/*
3144 * ext4_orphan_del() removes an unlinked or truncated inode from the list
3145 * of such inodes stored on disk, because it is finally being cleaned up.
3146 */
3147int ext4_orphan_del(handle_t *handle, struct inode *inode)
3148{
3149 struct list_head *prev;
3150 struct ext4_inode_info *ei = EXT4_I(inode);
3151 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
3152 __u32 ino_next;
3153 struct ext4_iloc iloc;
3154 int err = 0;
3155
3156 if (!sbi->s_journal && !(sbi->s_mount_state & EXT4_ORPHAN_FS))
3157 return 0;
3158
3159 WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
3160 !inode_is_locked(inode));
3161 /* Do this quick check before taking global s_orphan_lock. */
3162 if (list_empty(&ei->i_orphan))
3163 return 0;
3164
3165 if (handle) {
3166 /* Grab inode buffer early before taking global s_orphan_lock */
3167 err = ext4_reserve_inode_write(handle, inode, &iloc);
3168 }
3169
3170 mutex_lock(&sbi->s_orphan_lock);
3171 jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
3172
3173 prev = ei->i_orphan.prev;
3174 list_del_init(&ei->i_orphan);
3175
3176 /* If we're on an error path, we may not have a valid
3177 * transaction handle with which to update the orphan list on
3178 * disk, but we still need to remove the inode from the linked
3179 * list in memory. */
3180 if (!handle || err) {
3181 mutex_unlock(&sbi->s_orphan_lock);
3182 goto out_err;
3183 }
3184
3185 ino_next = NEXT_ORPHAN(inode);
3186 if (prev == &sbi->s_orphan) {
3187 jbd_debug(4, "superblock will point to %u\n", ino_next);
3188 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
3189 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
3190 if (err) {
3191 mutex_unlock(&sbi->s_orphan_lock);
3192 goto out_brelse;
3193 }
3194 lock_buffer(sbi->s_sbh);
3195 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
3196 ext4_superblock_csum_set(inode->i_sb);
3197 unlock_buffer(sbi->s_sbh);
3198 mutex_unlock(&sbi->s_orphan_lock);
3199 err = ext4_handle_dirty_metadata(handle, NULL, sbi->s_sbh);
3200 } else {
3201 struct ext4_iloc iloc2;
3202 struct inode *i_prev =
3203 &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
3204
3205 jbd_debug(4, "orphan inode %lu will point to %u\n",
3206 i_prev->i_ino, ino_next);
3207 err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
3208 if (err) {
3209 mutex_unlock(&sbi->s_orphan_lock);
3210 goto out_brelse;
3211 }
3212 NEXT_ORPHAN(i_prev) = ino_next;
3213 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
3214 mutex_unlock(&sbi->s_orphan_lock);
3215 }
3216 if (err)
3217 goto out_brelse;
3218 NEXT_ORPHAN(inode) = 0;
3219 err = ext4_mark_iloc_dirty(handle, inode, &iloc);
3220out_err:
3221 ext4_std_error(inode->i_sb, err);
3222 return err;
3223
3224out_brelse:
3225 brelse(iloc.bh);
3226 goto out_err;
3227}
3228
3229static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
3230{
3231 int retval;
3232 struct inode *inode;
3233 struct buffer_head *bh;
3234 struct ext4_dir_entry_2 *de;
3235 handle_t *handle = NULL;
3236
3237 if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
3238 return -EIO;
3239
3240 /* Initialize quotas before so that eventual writes go in
3241 * separate transaction */
3242 retval = dquot_initialize(dir);
3243 if (retval)
3244 return retval;
3245 retval = dquot_initialize(d_inode(dentry));
3246 if (retval)
3247 return retval;
3248
3249 retval = -ENOENT;
3250 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
3251 if (IS_ERR(bh))
3252 return PTR_ERR(bh);
3253 if (!bh)
3254 goto end_rmdir;
3255
3256 inode = d_inode(dentry);
3257
3258 retval = -EFSCORRUPTED;
3259 if (le32_to_cpu(de->inode) != inode->i_ino)
3260 goto end_rmdir;
3261
3262 retval = -ENOTEMPTY;
3263 if (!ext4_empty_dir(inode))
3264 goto end_rmdir;
3265
3266 handle = ext4_journal_start(dir, EXT4_HT_DIR,
3267 EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
3268 if (IS_ERR(handle)) {
3269 retval = PTR_ERR(handle);
3270 handle = NULL;
3271 goto end_rmdir;
3272 }
3273
3274 if (IS_DIRSYNC(dir))
3275 ext4_handle_sync(handle);
3276
3277 retval = ext4_delete_entry(handle, dir, de, bh);
3278 if (retval)
3279 goto end_rmdir;
3280 if (!EXT4_DIR_LINK_EMPTY(inode))
3281 ext4_warning_inode(inode,
3282 "empty directory '%.*s' has too many links (%u)",
3283 dentry->d_name.len, dentry->d_name.name,
3284 inode->i_nlink);
3285 inode_inc_iversion(inode);
3286 clear_nlink(inode);
3287 /* There's no need to set i_disksize: the fact that i_nlink is
3288 * zero will ensure that the right thing happens during any
3289 * recovery. */
3290 inode->i_size = 0;
3291 ext4_orphan_add(handle, inode);
3292 inode->i_ctime = dir->i_ctime = dir->i_mtime = current_time(inode);
3293 retval = ext4_mark_inode_dirty(handle, inode);
3294 if (retval)
3295 goto end_rmdir;
3296 ext4_dec_count(dir);
3297 ext4_update_dx_flag(dir);
3298 ext4_fc_track_unlink(handle, dentry);
3299 retval = ext4_mark_inode_dirty(handle, dir);
3300
3301#ifdef CONFIG_UNICODE
3302 /* VFS negative dentries are incompatible with Encoding and
3303 * Case-insensitiveness. Eventually we'll want avoid
3304 * invalidating the dentries here, alongside with returning the
3305 * negative dentries at ext4_lookup(), when it is better
3306 * supported by the VFS for the CI case.
3307 */
3308 if (IS_CASEFOLDED(dir))
3309 d_invalidate(dentry);
3310#endif
3311
3312end_rmdir:
3313 brelse(bh);
3314 if (handle)
3315 ext4_journal_stop(handle);
3316 return retval;
3317}
3318
3319int __ext4_unlink(handle_t *handle, struct inode *dir, const struct qstr *d_name,
3320 struct inode *inode)
3321{
3322 int retval = -ENOENT;
3323 struct buffer_head *bh;
3324 struct ext4_dir_entry_2 *de;
3325 int skip_remove_dentry = 0;
3326
3327 bh = ext4_find_entry(dir, d_name, &de, NULL);
3328 if (IS_ERR(bh))
3329 return PTR_ERR(bh);
3330
3331 if (!bh)
3332 return -ENOENT;
3333
3334 if (le32_to_cpu(de->inode) != inode->i_ino) {
3335 /*
3336 * It's okay if we find dont find dentry which matches
3337 * the inode. That's because it might have gotten
3338 * renamed to a different inode number
3339 */
3340 if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
3341 skip_remove_dentry = 1;
3342 else
3343 goto out;
3344 }
3345
3346 if (IS_DIRSYNC(dir))
3347 ext4_handle_sync(handle);
3348
3349 if (!skip_remove_dentry) {
3350 retval = ext4_delete_entry(handle, dir, de, bh);
3351 if (retval)
3352 goto out;
3353 dir->i_ctime = dir->i_mtime = current_time(dir);
3354 ext4_update_dx_flag(dir);
3355 retval = ext4_mark_inode_dirty(handle, dir);
3356 if (retval)
3357 goto out;
3358 } else {
3359 retval = 0;
3360 }
3361 if (inode->i_nlink == 0)
3362 ext4_warning_inode(inode, "Deleting file '%.*s' with no links",
3363 d_name->len, d_name->name);
3364 else
3365 drop_nlink(inode);
3366 if (!inode->i_nlink)
3367 ext4_orphan_add(handle, inode);
3368 inode->i_ctime = current_time(inode);
3369 retval = ext4_mark_inode_dirty(handle, inode);
3370
3371out:
3372 brelse(bh);
3373 return retval;
3374}
3375
3376static int ext4_unlink(struct inode *dir, struct dentry *dentry)
3377{
3378 handle_t *handle;
3379 int retval;
3380
3381 if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
3382 return -EIO;
3383
3384 trace_ext4_unlink_enter(dir, dentry);
3385 /*
3386 * Initialize quotas before so that eventual writes go
3387 * in separate transaction
3388 */
3389 retval = dquot_initialize(dir);
3390 if (retval)
3391 goto out_trace;
3392 retval = dquot_initialize(d_inode(dentry));
3393 if (retval)
3394 goto out_trace;
3395
3396 handle = ext4_journal_start(dir, EXT4_HT_DIR,
3397 EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
3398 if (IS_ERR(handle)) {
3399 retval = PTR_ERR(handle);
3400 goto out_trace;
3401 }
3402
3403 retval = __ext4_unlink(handle, dir, &dentry->d_name, d_inode(dentry));
3404 if (!retval)
3405 ext4_fc_track_unlink(handle, dentry);
3406#ifdef CONFIG_UNICODE
3407 /* VFS negative dentries are incompatible with Encoding and
3408 * Case-insensitiveness. Eventually we'll want avoid
3409 * invalidating the dentries here, alongside with returning the
3410 * negative dentries at ext4_lookup(), when it is better
3411 * supported by the VFS for the CI case.
3412 */
3413 if (IS_CASEFOLDED(dir))
3414 d_invalidate(dentry);
3415#endif
3416 if (handle)
3417 ext4_journal_stop(handle);
3418
3419out_trace:
3420 trace_ext4_unlink_exit(dentry, retval);
3421 return retval;
3422}
3423
3424static int ext4_symlink(struct user_namespace *mnt_userns, struct inode *dir,
3425 struct dentry *dentry, const char *symname)
3426{
3427 handle_t *handle;
3428 struct inode *inode;
3429 int err, len = strlen(symname);
3430 int credits;
3431 struct fscrypt_str disk_link;
3432
3433 if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
3434 return -EIO;
3435
3436 err = fscrypt_prepare_symlink(dir, symname, len, dir->i_sb->s_blocksize,
3437 &disk_link);
3438 if (err)
3439 return err;
3440
3441 err = dquot_initialize(dir);
3442 if (err)
3443 return err;
3444
3445 if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
3446 /*
3447 * For non-fast symlinks, we just allocate inode and put it on
3448 * orphan list in the first transaction => we need bitmap,
3449 * group descriptor, sb, inode block, quota blocks, and
3450 * possibly selinux xattr blocks.
3451 */
3452 credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
3453 EXT4_XATTR_TRANS_BLOCKS;
3454 } else {
3455 /*
3456 * Fast symlink. We have to add entry to directory
3457 * (EXT4_DATA_TRANS_BLOCKS + EXT4_INDEX_EXTRA_TRANS_BLOCKS),
3458 * allocate new inode (bitmap, group descriptor, inode block,
3459 * quota blocks, sb is already counted in previous macros).
3460 */
3461 credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3462 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3;
3463 }
3464
3465 inode = ext4_new_inode_start_handle(mnt_userns, dir, S_IFLNK|S_IRWXUGO,
3466 &dentry->d_name, 0, NULL,
3467 EXT4_HT_DIR, credits);
3468 handle = ext4_journal_current_handle();
3469 if (IS_ERR(inode)) {
3470 if (handle)
3471 ext4_journal_stop(handle);
3472 return PTR_ERR(inode);
3473 }
3474
3475 if (IS_ENCRYPTED(inode)) {
3476 err = fscrypt_encrypt_symlink(inode, symname, len, &disk_link);
3477 if (err)
3478 goto err_drop_inode;
3479 inode->i_op = &ext4_encrypted_symlink_inode_operations;
3480 }
3481
3482 if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
3483 if (!IS_ENCRYPTED(inode))
3484 inode->i_op = &ext4_symlink_inode_operations;
3485 inode_nohighmem(inode);
3486 ext4_set_aops(inode);
3487 /*
3488 * We cannot call page_symlink() with transaction started
3489 * because it calls into ext4_write_begin() which can wait
3490 * for transaction commit if we are running out of space
3491 * and thus we deadlock. So we have to stop transaction now
3492 * and restart it when symlink contents is written.
3493 *
3494 * To keep fs consistent in case of crash, we have to put inode
3495 * to orphan list in the mean time.
3496 */
3497 drop_nlink(inode);
3498 err = ext4_orphan_add(handle, inode);
3499 if (handle)
3500 ext4_journal_stop(handle);
3501 handle = NULL;
3502 if (err)
3503 goto err_drop_inode;
3504 err = __page_symlink(inode, disk_link.name, disk_link.len, 1);
3505 if (err)
3506 goto err_drop_inode;
3507 /*
3508 * Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS
3509 * + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified
3510 */
3511 handle = ext4_journal_start(dir, EXT4_HT_DIR,
3512 EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3513 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1);
3514 if (IS_ERR(handle)) {
3515 err = PTR_ERR(handle);
3516 handle = NULL;
3517 goto err_drop_inode;
3518 }
3519 set_nlink(inode, 1);
3520 err = ext4_orphan_del(handle, inode);
3521 if (err)
3522 goto err_drop_inode;
3523 } else {
3524 /* clear the extent format for fast symlink */
3525 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
3526 if (!IS_ENCRYPTED(inode)) {
3527 inode->i_op = &ext4_fast_symlink_inode_operations;
3528 inode->i_link = (char *)&EXT4_I(inode)->i_data;
3529 }
3530 memcpy((char *)&EXT4_I(inode)->i_data, disk_link.name,
3531 disk_link.len);
3532 inode->i_size = disk_link.len - 1;
3533 }
3534 EXT4_I(inode)->i_disksize = inode->i_size;
3535 err = ext4_add_nondir(handle, dentry, &inode);
3536 if (handle)
3537 ext4_journal_stop(handle);
3538 if (inode)
3539 iput(inode);
3540 goto out_free_encrypted_link;
3541
3542err_drop_inode:
3543 if (handle)
3544 ext4_journal_stop(handle);
3545 clear_nlink(inode);
3546 unlock_new_inode(inode);
3547 iput(inode);
3548out_free_encrypted_link:
3549 if (disk_link.name != (unsigned char *)symname)
3550 kfree(disk_link.name);
3551 return err;
3552}
3553
3554int __ext4_link(struct inode *dir, struct inode *inode, struct dentry *dentry)
3555{
3556 handle_t *handle;
3557 int err, retries = 0;
3558retry:
3559 handle = ext4_journal_start(dir, EXT4_HT_DIR,
3560 (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3561 EXT4_INDEX_EXTRA_TRANS_BLOCKS) + 1);
3562 if (IS_ERR(handle))
3563 return PTR_ERR(handle);
3564
3565 if (IS_DIRSYNC(dir))
3566 ext4_handle_sync(handle);
3567
3568 inode->i_ctime = current_time(inode);
3569 ext4_inc_count(inode);
3570 ihold(inode);
3571
3572 err = ext4_add_entry(handle, dentry, inode);
3573 if (!err) {
3574 err = ext4_mark_inode_dirty(handle, inode);
3575 /* this can happen only for tmpfile being
3576 * linked the first time
3577 */
3578 if (inode->i_nlink == 1)
3579 ext4_orphan_del(handle, inode);
3580 d_instantiate(dentry, inode);
3581 ext4_fc_track_link(handle, dentry);
3582 } else {
3583 drop_nlink(inode);
3584 iput(inode);
3585 }
3586 ext4_journal_stop(handle);
3587 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
3588 goto retry;
3589 return err;
3590}
3591
3592static int ext4_link(struct dentry *old_dentry,
3593 struct inode *dir, struct dentry *dentry)
3594{
3595 struct inode *inode = d_inode(old_dentry);
3596 int err;
3597
3598 if (inode->i_nlink >= EXT4_LINK_MAX)
3599 return -EMLINK;
3600
3601 err = fscrypt_prepare_link(old_dentry, dir, dentry);
3602 if (err)
3603 return err;
3604
3605 if ((ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT)) &&
3606 (!projid_eq(EXT4_I(dir)->i_projid,
3607 EXT4_I(old_dentry->d_inode)->i_projid)))
3608 return -EXDEV;
3609
3610 err = dquot_initialize(dir);
3611 if (err)
3612 return err;
3613 return __ext4_link(dir, inode, dentry);
3614}
3615
3616/*
3617 * Try to find buffer head where contains the parent block.
3618 * It should be the inode block if it is inlined or the 1st block
3619 * if it is a normal dir.
3620 */
3621static struct buffer_head *ext4_get_first_dir_block(handle_t *handle,
3622 struct inode *inode,
3623 int *retval,
3624 struct ext4_dir_entry_2 **parent_de,
3625 int *inlined)
3626{
3627 struct buffer_head *bh;
3628
3629 if (!ext4_has_inline_data(inode)) {
3630 /* The first directory block must not be a hole, so
3631 * treat it as DIRENT_HTREE
3632 */
3633 bh = ext4_read_dirblock(inode, 0, DIRENT_HTREE);
3634 if (IS_ERR(bh)) {
3635 *retval = PTR_ERR(bh);
3636 return NULL;
3637 }
3638 *parent_de = ext4_next_entry(
3639 (struct ext4_dir_entry_2 *)bh->b_data,
3640 inode->i_sb->s_blocksize);
3641 return bh;
3642 }
3643
3644 *inlined = 1;
3645 return ext4_get_first_inline_block(inode, parent_de, retval);
3646}
3647
3648struct ext4_renament {
3649 struct inode *dir;
3650 struct dentry *dentry;
3651 struct inode *inode;
3652 bool is_dir;
3653 int dir_nlink_delta;
3654
3655 /* entry for "dentry" */
3656 struct buffer_head *bh;
3657 struct ext4_dir_entry_2 *de;
3658 int inlined;
3659
3660 /* entry for ".." in inode if it's a directory */
3661 struct buffer_head *dir_bh;
3662 struct ext4_dir_entry_2 *parent_de;
3663 int dir_inlined;
3664};
3665
3666static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent)
3667{
3668 int retval;
3669
3670 ent->dir_bh = ext4_get_first_dir_block(handle, ent->inode,
3671 &retval, &ent->parent_de,
3672 &ent->dir_inlined);
3673 if (!ent->dir_bh)
3674 return retval;
3675 if (le32_to_cpu(ent->parent_de->inode) != ent->dir->i_ino)
3676 return -EFSCORRUPTED;
3677 BUFFER_TRACE(ent->dir_bh, "get_write_access");
3678 return ext4_journal_get_write_access(handle, ent->dir_bh);
3679}
3680
3681static int ext4_rename_dir_finish(handle_t *handle, struct ext4_renament *ent,
3682 unsigned dir_ino)
3683{
3684 int retval;
3685
3686 ent->parent_de->inode = cpu_to_le32(dir_ino);
3687 BUFFER_TRACE(ent->dir_bh, "call ext4_handle_dirty_metadata");
3688 if (!ent->dir_inlined) {
3689 if (is_dx(ent->inode)) {
3690 retval = ext4_handle_dirty_dx_node(handle,
3691 ent->inode,
3692 ent->dir_bh);
3693 } else {
3694 retval = ext4_handle_dirty_dirblock(handle, ent->inode,
3695 ent->dir_bh);
3696 }
3697 } else {
3698 retval = ext4_mark_inode_dirty(handle, ent->inode);
3699 }
3700 if (retval) {
3701 ext4_std_error(ent->dir->i_sb, retval);
3702 return retval;
3703 }
3704 return 0;
3705}
3706
3707static int ext4_setent(handle_t *handle, struct ext4_renament *ent,
3708 unsigned ino, unsigned file_type)
3709{
3710 int retval, retval2;
3711
3712 BUFFER_TRACE(ent->bh, "get write access");
3713 retval = ext4_journal_get_write_access(handle, ent->bh);
3714 if (retval)
3715 return retval;
3716 ent->de->inode = cpu_to_le32(ino);
3717 if (ext4_has_feature_filetype(ent->dir->i_sb))
3718 ent->de->file_type = file_type;
3719 inode_inc_iversion(ent->dir);
3720 ent->dir->i_ctime = ent->dir->i_mtime =
3721 current_time(ent->dir);
3722 retval = ext4_mark_inode_dirty(handle, ent->dir);
3723 BUFFER_TRACE(ent->bh, "call ext4_handle_dirty_metadata");
3724 if (!ent->inlined) {
3725 retval2 = ext4_handle_dirty_dirblock(handle, ent->dir, ent->bh);
3726 if (unlikely(retval2)) {
3727 ext4_std_error(ent->dir->i_sb, retval2);
3728 return retval2;
3729 }
3730 }
3731 return retval;
3732}
3733
3734static void ext4_resetent(handle_t *handle, struct ext4_renament *ent,
3735 unsigned ino, unsigned file_type)
3736{
3737 struct ext4_renament old = *ent;
3738 int retval = 0;
3739
3740 /*
3741 * old->de could have moved from under us during make indexed dir,
3742 * so the old->de may no longer valid and need to find it again
3743 * before reset old inode info.
3744 */
3745 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, NULL);
3746 if (IS_ERR(old.bh))
3747 retval = PTR_ERR(old.bh);
3748 if (!old.bh)
3749 retval = -ENOENT;
3750 if (retval) {
3751 ext4_std_error(old.dir->i_sb, retval);
3752 return;
3753 }
3754
3755 ext4_setent(handle, &old, ino, file_type);
3756 brelse(old.bh);
3757}
3758
3759static int ext4_find_delete_entry(handle_t *handle, struct inode *dir,
3760 const struct qstr *d_name)
3761{
3762 int retval = -ENOENT;
3763 struct buffer_head *bh;
3764 struct ext4_dir_entry_2 *de;
3765
3766 bh = ext4_find_entry(dir, d_name, &de, NULL);
3767 if (IS_ERR(bh))
3768 return PTR_ERR(bh);
3769 if (bh) {
3770 retval = ext4_delete_entry(handle, dir, de, bh);
3771 brelse(bh);
3772 }
3773 return retval;
3774}
3775
3776static void ext4_rename_delete(handle_t *handle, struct ext4_renament *ent,
3777 int force_reread)
3778{
3779 int retval;
3780 /*
3781 * ent->de could have moved from under us during htree split, so make
3782 * sure that we are deleting the right entry. We might also be pointing
3783 * to a stale entry in the unused part of ent->bh so just checking inum
3784 * and the name isn't enough.
3785 */
3786 if (le32_to_cpu(ent->de->inode) != ent->inode->i_ino ||
3787 ent->de->name_len != ent->dentry->d_name.len ||
3788 strncmp(ent->de->name, ent->dentry->d_name.name,
3789 ent->de->name_len) ||
3790 force_reread) {
3791 retval = ext4_find_delete_entry(handle, ent->dir,
3792 &ent->dentry->d_name);
3793 } else {
3794 retval = ext4_delete_entry(handle, ent->dir, ent->de, ent->bh);
3795 if (retval == -ENOENT) {
3796 retval = ext4_find_delete_entry(handle, ent->dir,
3797 &ent->dentry->d_name);
3798 }
3799 }
3800
3801 if (retval) {
3802 ext4_warning_inode(ent->dir,
3803 "Deleting old file: nlink %d, error=%d",
3804 ent->dir->i_nlink, retval);
3805 }
3806}
3807
3808static void ext4_update_dir_count(handle_t *handle, struct ext4_renament *ent)
3809{
3810 if (ent->dir_nlink_delta) {
3811 if (ent->dir_nlink_delta == -1)
3812 ext4_dec_count(ent->dir);
3813 else
3814 ext4_inc_count(ent->dir);
3815 ext4_mark_inode_dirty(handle, ent->dir);
3816 }
3817}
3818
3819static struct inode *ext4_whiteout_for_rename(struct user_namespace *mnt_userns,
3820 struct ext4_renament *ent,
3821 int credits, handle_t **h)
3822{
3823 struct inode *wh;
3824 handle_t *handle;
3825 int retries = 0;
3826
3827 /*
3828 * for inode block, sb block, group summaries,
3829 * and inode bitmap
3830 */
3831 credits += (EXT4_MAXQUOTAS_TRANS_BLOCKS(ent->dir->i_sb) +
3832 EXT4_XATTR_TRANS_BLOCKS + 4);
3833retry:
3834 wh = ext4_new_inode_start_handle(mnt_userns, ent->dir,
3835 S_IFCHR | WHITEOUT_MODE,
3836 &ent->dentry->d_name, 0, NULL,
3837 EXT4_HT_DIR, credits);
3838
3839 handle = ext4_journal_current_handle();
3840 if (IS_ERR(wh)) {
3841 if (handle)
3842 ext4_journal_stop(handle);
3843 if (PTR_ERR(wh) == -ENOSPC &&
3844 ext4_should_retry_alloc(ent->dir->i_sb, &retries))
3845 goto retry;
3846 } else {
3847 *h = handle;
3848 init_special_inode(wh, wh->i_mode, WHITEOUT_DEV);
3849 wh->i_op = &ext4_special_inode_operations;
3850 }
3851 return wh;
3852}
3853
3854/*
3855 * Anybody can rename anything with this: the permission checks are left to the
3856 * higher-level routines.
3857 *
3858 * n.b. old_{dentry,inode) refers to the source dentry/inode
3859 * while new_{dentry,inode) refers to the destination dentry/inode
3860 * This comes from rename(const char *oldpath, const char *newpath)
3861 */
3862static int ext4_rename(struct user_namespace *mnt_userns, struct inode *old_dir,
3863 struct dentry *old_dentry, struct inode *new_dir,
3864 struct dentry *new_dentry, unsigned int flags)
3865{
3866 handle_t *handle = NULL;
3867 struct ext4_renament old = {
3868 .dir = old_dir,
3869 .dentry = old_dentry,
3870 .inode = d_inode(old_dentry),
3871 };
3872 struct ext4_renament new = {
3873 .dir = new_dir,
3874 .dentry = new_dentry,
3875 .inode = d_inode(new_dentry),
3876 };
3877 int force_reread;
3878 int retval;
3879 struct inode *whiteout = NULL;
3880 int credits;
3881 u8 old_file_type;
3882
3883 if (new.inode && new.inode->i_nlink == 0) {
3884 EXT4_ERROR_INODE(new.inode,
3885 "target of rename is already freed");
3886 return -EFSCORRUPTED;
3887 }
3888
3889 if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT)) &&
3890 (!projid_eq(EXT4_I(new_dir)->i_projid,
3891 EXT4_I(old_dentry->d_inode)->i_projid)))
3892 return -EXDEV;
3893
3894 retval = dquot_initialize(old.dir);
3895 if (retval)
3896 return retval;
3897 retval = dquot_initialize(new.dir);
3898 if (retval)
3899 return retval;
3900
3901 /* Initialize quotas before so that eventual writes go
3902 * in separate transaction */
3903 if (new.inode) {
3904 retval = dquot_initialize(new.inode);
3905 if (retval)
3906 return retval;
3907 }
3908
3909 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, NULL);
3910 if (IS_ERR(old.bh))
3911 return PTR_ERR(old.bh);
3912 /*
3913 * Check for inode number is _not_ due to possible IO errors.
3914 * We might rmdir the source, keep it as pwd of some process
3915 * and merrily kill the link to whatever was created under the
3916 * same name. Goodbye sticky bit ;-<
3917 */
3918 retval = -ENOENT;
3919 if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3920 goto release_bh;
3921
3922 new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
3923 &new.de, &new.inlined);
3924 if (IS_ERR(new.bh)) {
3925 retval = PTR_ERR(new.bh);
3926 new.bh = NULL;
3927 goto release_bh;
3928 }
3929 if (new.bh) {
3930 if (!new.inode) {
3931 brelse(new.bh);
3932 new.bh = NULL;
3933 }
3934 }
3935 if (new.inode && !test_opt(new.dir->i_sb, NO_AUTO_DA_ALLOC))
3936 ext4_alloc_da_blocks(old.inode);
3937
3938 credits = (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3939 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
3940 if (!(flags & RENAME_WHITEOUT)) {
3941 handle = ext4_journal_start(old.dir, EXT4_HT_DIR, credits);
3942 if (IS_ERR(handle)) {
3943 retval = PTR_ERR(handle);
3944 goto release_bh;
3945 }
3946 } else {
3947 whiteout = ext4_whiteout_for_rename(mnt_userns, &old, credits, &handle);
3948 if (IS_ERR(whiteout)) {
3949 retval = PTR_ERR(whiteout);
3950 goto release_bh;
3951 }
3952 }
3953
3954 old_file_type = old.de->file_type;
3955 if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3956 ext4_handle_sync(handle);
3957
3958 if (S_ISDIR(old.inode->i_mode)) {
3959 if (new.inode) {
3960 retval = -ENOTEMPTY;
3961 if (!ext4_empty_dir(new.inode))
3962 goto end_rename;
3963 } else {
3964 retval = -EMLINK;
3965 if (new.dir != old.dir && EXT4_DIR_LINK_MAX(new.dir))
3966 goto end_rename;
3967 }
3968 retval = ext4_rename_dir_prepare(handle, &old);
3969 if (retval)
3970 goto end_rename;
3971 }
3972 /*
3973 * If we're renaming a file within an inline_data dir and adding or
3974 * setting the new dirent causes a conversion from inline_data to
3975 * extents/blockmap, we need to force the dirent delete code to
3976 * re-read the directory, or else we end up trying to delete a dirent
3977 * from what is now the extent tree root (or a block map).
3978 */
3979 force_reread = (new.dir->i_ino == old.dir->i_ino &&
3980 ext4_test_inode_flag(new.dir, EXT4_INODE_INLINE_DATA));
3981
3982 if (whiteout) {
3983 /*
3984 * Do this before adding a new entry, so the old entry is sure
3985 * to be still pointing to the valid old entry.
3986 */
3987 retval = ext4_setent(handle, &old, whiteout->i_ino,
3988 EXT4_FT_CHRDEV);
3989 if (retval)
3990 goto end_rename;
3991 retval = ext4_mark_inode_dirty(handle, whiteout);
3992 if (unlikely(retval))
3993 goto end_rename;
3994
3995 }
3996 if (!new.bh) {
3997 retval = ext4_add_entry(handle, new.dentry, old.inode);
3998 if (retval)
3999 goto end_rename;
4000 } else {
4001 retval = ext4_setent(handle, &new,
4002 old.inode->i_ino, old_file_type);
4003 if (retval)
4004 goto end_rename;
4005 }
4006 if (force_reread)
4007 force_reread = !ext4_test_inode_flag(new.dir,
4008 EXT4_INODE_INLINE_DATA);
4009
4010 /*
4011 * Like most other Unix systems, set the ctime for inodes on a
4012 * rename.
4013 */
4014 old.inode->i_ctime = current_time(old.inode);
4015 retval = ext4_mark_inode_dirty(handle, old.inode);
4016 if (unlikely(retval))
4017 goto end_rename;
4018
4019 if (!whiteout) {
4020 /*
4021 * ok, that's it
4022 */
4023 ext4_rename_delete(handle, &old, force_reread);
4024 }
4025
4026 if (new.inode) {
4027 ext4_dec_count(new.inode);
4028 new.inode->i_ctime = current_time(new.inode);
4029 }
4030 old.dir->i_ctime = old.dir->i_mtime = current_time(old.dir);
4031 ext4_update_dx_flag(old.dir);
4032 if (old.dir_bh) {
4033 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
4034 if (retval)
4035 goto end_rename;
4036
4037 ext4_dec_count(old.dir);
4038 if (new.inode) {
4039 /* checked ext4_empty_dir above, can't have another
4040 * parent, ext4_dec_count() won't work for many-linked
4041 * dirs */
4042 clear_nlink(new.inode);
4043 } else {
4044 ext4_inc_count(new.dir);
4045 ext4_update_dx_flag(new.dir);
4046 retval = ext4_mark_inode_dirty(handle, new.dir);
4047 if (unlikely(retval))
4048 goto end_rename;
4049 }
4050 }
4051 retval = ext4_mark_inode_dirty(handle, old.dir);
4052 if (unlikely(retval))
4053 goto end_rename;
4054
4055 if (S_ISDIR(old.inode->i_mode)) {
4056 /*
4057 * We disable fast commits here that's because the
4058 * replay code is not yet capable of changing dot dot
4059 * dirents in directories.
4060 */
4061 ext4_fc_mark_ineligible(old.inode->i_sb,
4062 EXT4_FC_REASON_RENAME_DIR);
4063 } else {
4064 if (new.inode)
4065 ext4_fc_track_unlink(handle, new.dentry);
4066 __ext4_fc_track_link(handle, old.inode, new.dentry);
4067 __ext4_fc_track_unlink(handle, old.inode, old.dentry);
4068 if (whiteout)
4069 __ext4_fc_track_create(handle, whiteout, old.dentry);
4070 }
4071
4072 if (new.inode) {
4073 retval = ext4_mark_inode_dirty(handle, new.inode);
4074 if (unlikely(retval))
4075 goto end_rename;
4076 if (!new.inode->i_nlink)
4077 ext4_orphan_add(handle, new.inode);
4078 }
4079 retval = 0;
4080
4081end_rename:
4082 if (whiteout) {
4083 if (retval) {
4084 ext4_resetent(handle, &old,
4085 old.inode->i_ino, old_file_type);
4086 drop_nlink(whiteout);
4087 ext4_orphan_add(handle, whiteout);
4088 }
4089 unlock_new_inode(whiteout);
4090 ext4_journal_stop(handle);
4091 iput(whiteout);
4092 } else {
4093 ext4_journal_stop(handle);
4094 }
4095release_bh:
4096 brelse(old.dir_bh);
4097 brelse(old.bh);
4098 brelse(new.bh);
4099 return retval;
4100}
4101
4102static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
4103 struct inode *new_dir, struct dentry *new_dentry)
4104{
4105 handle_t *handle = NULL;
4106 struct ext4_renament old = {
4107 .dir = old_dir,
4108 .dentry = old_dentry,
4109 .inode = d_inode(old_dentry),
4110 };
4111 struct ext4_renament new = {
4112 .dir = new_dir,
4113 .dentry = new_dentry,
4114 .inode = d_inode(new_dentry),
4115 };
4116 u8 new_file_type;
4117 int retval;
4118 struct timespec64 ctime;
4119
4120 if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT) &&
4121 !projid_eq(EXT4_I(new_dir)->i_projid,
4122 EXT4_I(old_dentry->d_inode)->i_projid)) ||
4123 (ext4_test_inode_flag(old_dir, EXT4_INODE_PROJINHERIT) &&
4124 !projid_eq(EXT4_I(old_dir)->i_projid,
4125 EXT4_I(new_dentry->d_inode)->i_projid)))
4126 return -EXDEV;
4127
4128 retval = dquot_initialize(old.dir);
4129 if (retval)
4130 return retval;
4131 retval = dquot_initialize(new.dir);
4132 if (retval)
4133 return retval;
4134
4135 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name,
4136 &old.de, &old.inlined);
4137 if (IS_ERR(old.bh))
4138 return PTR_ERR(old.bh);
4139 /*
4140 * Check for inode number is _not_ due to possible IO errors.
4141 * We might rmdir the source, keep it as pwd of some process
4142 * and merrily kill the link to whatever was created under the
4143 * same name. Goodbye sticky bit ;-<
4144 */
4145 retval = -ENOENT;
4146 if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
4147 goto end_rename;
4148
4149 new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
4150 &new.de, &new.inlined);
4151 if (IS_ERR(new.bh)) {
4152 retval = PTR_ERR(new.bh);
4153 new.bh = NULL;
4154 goto end_rename;
4155 }
4156
4157 /* RENAME_EXCHANGE case: old *and* new must both exist */
4158 if (!new.bh || le32_to_cpu(new.de->inode) != new.inode->i_ino)
4159 goto end_rename;
4160
4161 handle = ext4_journal_start(old.dir, EXT4_HT_DIR,
4162 (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
4163 2 * EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2));
4164 if (IS_ERR(handle)) {
4165 retval = PTR_ERR(handle);
4166 handle = NULL;
4167 goto end_rename;
4168 }
4169
4170 if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
4171 ext4_handle_sync(handle);
4172
4173 if (S_ISDIR(old.inode->i_mode)) {
4174 old.is_dir = true;
4175 retval = ext4_rename_dir_prepare(handle, &old);
4176 if (retval)
4177 goto end_rename;
4178 }
4179 if (S_ISDIR(new.inode->i_mode)) {
4180 new.is_dir = true;
4181 retval = ext4_rename_dir_prepare(handle, &new);
4182 if (retval)
4183 goto end_rename;
4184 }
4185
4186 /*
4187 * Other than the special case of overwriting a directory, parents'
4188 * nlink only needs to be modified if this is a cross directory rename.
4189 */
4190 if (old.dir != new.dir && old.is_dir != new.is_dir) {
4191 old.dir_nlink_delta = old.is_dir ? -1 : 1;
4192 new.dir_nlink_delta = -old.dir_nlink_delta;
4193 retval = -EMLINK;
4194 if ((old.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(old.dir)) ||
4195 (new.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(new.dir)))
4196 goto end_rename;
4197 }
4198
4199 new_file_type = new.de->file_type;
4200 retval = ext4_setent(handle, &new, old.inode->i_ino, old.de->file_type);
4201 if (retval)
4202 goto end_rename;
4203
4204 retval = ext4_setent(handle, &old, new.inode->i_ino, new_file_type);
4205 if (retval)
4206 goto end_rename;
4207
4208 /*
4209 * Like most other Unix systems, set the ctime for inodes on a
4210 * rename.
4211 */
4212 ctime = current_time(old.inode);
4213 old.inode->i_ctime = ctime;
4214 new.inode->i_ctime = ctime;
4215 retval = ext4_mark_inode_dirty(handle, old.inode);
4216 if (unlikely(retval))
4217 goto end_rename;
4218 retval = ext4_mark_inode_dirty(handle, new.inode);
4219 if (unlikely(retval))
4220 goto end_rename;
4221 ext4_fc_mark_ineligible(new.inode->i_sb,
4222 EXT4_FC_REASON_CROSS_RENAME);
4223 if (old.dir_bh) {
4224 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
4225 if (retval)
4226 goto end_rename;
4227 }
4228 if (new.dir_bh) {
4229 retval = ext4_rename_dir_finish(handle, &new, old.dir->i_ino);
4230 if (retval)
4231 goto end_rename;
4232 }
4233 ext4_update_dir_count(handle, &old);
4234 ext4_update_dir_count(handle, &new);
4235 retval = 0;
4236
4237end_rename:
4238 brelse(old.dir_bh);
4239 brelse(new.dir_bh);
4240 brelse(old.bh);
4241 brelse(new.bh);
4242 if (handle)
4243 ext4_journal_stop(handle);
4244 return retval;
4245}
4246
4247static int ext4_rename2(struct user_namespace *mnt_userns,
4248 struct inode *old_dir, struct dentry *old_dentry,
4249 struct inode *new_dir, struct dentry *new_dentry,
4250 unsigned int flags)
4251{
4252 int err;
4253
4254 if (unlikely(ext4_forced_shutdown(EXT4_SB(old_dir->i_sb))))
4255 return -EIO;
4256
4257 if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
4258 return -EINVAL;
4259
4260 err = fscrypt_prepare_rename(old_dir, old_dentry, new_dir, new_dentry,
4261 flags);
4262 if (err)
4263 return err;
4264
4265 if (flags & RENAME_EXCHANGE) {
4266 return ext4_cross_rename(old_dir, old_dentry,
4267 new_dir, new_dentry);
4268 }
4269
4270 return ext4_rename(mnt_userns, old_dir, old_dentry, new_dir, new_dentry, flags);
4271}
4272
4273/*
4274 * directories can handle most operations...
4275 */
4276const struct inode_operations ext4_dir_inode_operations = {
4277 .create = ext4_create,
4278 .lookup = ext4_lookup,
4279 .link = ext4_link,
4280 .unlink = ext4_unlink,
4281 .symlink = ext4_symlink,
4282 .mkdir = ext4_mkdir,
4283 .rmdir = ext4_rmdir,
4284 .mknod = ext4_mknod,
4285 .tmpfile = ext4_tmpfile,
4286 .rename = ext4_rename2,
4287 .setattr = ext4_setattr,
4288 .getattr = ext4_getattr,
4289 .listxattr = ext4_listxattr,
4290 .get_acl = ext4_get_acl,
4291 .set_acl = ext4_set_acl,
4292 .fiemap = ext4_fiemap,
4293 .fileattr_get = ext4_fileattr_get,
4294 .fileattr_set = ext4_fileattr_set,
4295};
4296
4297const struct inode_operations ext4_special_inode_operations = {
4298 .setattr = ext4_setattr,
4299 .getattr = ext4_getattr,
4300 .listxattr = ext4_listxattr,
4301 .get_acl = ext4_get_acl,
4302 .set_acl = ext4_set_acl,
4303};