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ext4: don't orphan or truncate the boot loader inode
[mirror_ubuntu-artful-kernel.git] / fs / ext4 / namei.c
1 /*
2 * linux/fs/ext4/namei.c
3 *
4 * Copyright (C) 1992, 1993, 1994, 1995
5 * Remy Card (card@masi.ibp.fr)
6 * Laboratoire MASI - Institut Blaise Pascal
7 * Universite Pierre et Marie Curie (Paris VI)
8 *
9 * from
10 *
11 * linux/fs/minix/namei.c
12 *
13 * Copyright (C) 1991, 1992 Linus Torvalds
14 *
15 * Big-endian to little-endian byte-swapping/bitmaps by
16 * David S. Miller (davem@caip.rutgers.edu), 1995
17 * Directory entry file type support and forward compatibility hooks
18 * for B-tree directories by Theodore Ts'o (tytso@mit.edu), 1998
19 * Hash Tree Directory indexing (c)
20 * Daniel Phillips, 2001
21 * Hash Tree Directory indexing porting
22 * Christopher Li, 2002
23 * Hash Tree Directory indexing cleanup
24 * Theodore Ts'o, 2002
25 */
26
27 #include <linux/fs.h>
28 #include <linux/pagemap.h>
29 #include <linux/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
51 static struct buffer_head *ext4_append(handle_t *handle,
52 struct inode *inode,
53 ext4_lblk_t *block)
54 {
55 struct buffer_head *bh;
56 int err;
57
58 if (unlikely(EXT4_SB(inode->i_sb)->s_max_dir_size_kb &&
59 ((inode->i_size >> 10) >=
60 EXT4_SB(inode->i_sb)->s_max_dir_size_kb)))
61 return ERR_PTR(-ENOSPC);
62
63 *block = inode->i_size >> inode->i_sb->s_blocksize_bits;
64
65 bh = ext4_bread(handle, inode, *block, 1);
66 if (IS_ERR(bh))
67 return bh;
68 inode->i_size += inode->i_sb->s_blocksize;
69 EXT4_I(inode)->i_disksize = inode->i_size;
70 BUFFER_TRACE(bh, "get_write_access");
71 err = ext4_journal_get_write_access(handle, bh);
72 if (err) {
73 brelse(bh);
74 ext4_std_error(inode->i_sb, err);
75 return ERR_PTR(err);
76 }
77 return bh;
78 }
79
80 static int ext4_dx_csum_verify(struct inode *inode,
81 struct ext4_dir_entry *dirent);
82
83 typedef enum {
84 EITHER, INDEX, DIRENT
85 } dirblock_type_t;
86
87 #define ext4_read_dirblock(inode, block, type) \
88 __ext4_read_dirblock((inode), (block), (type), __LINE__)
89
90 static struct buffer_head *__ext4_read_dirblock(struct inode *inode,
91 ext4_lblk_t block,
92 dirblock_type_t type,
93 unsigned int line)
94 {
95 struct buffer_head *bh;
96 struct ext4_dir_entry *dirent;
97 int is_dx_block = 0;
98
99 bh = ext4_bread(NULL, inode, block, 0);
100 if (IS_ERR(bh)) {
101 __ext4_warning(inode->i_sb, __func__, line,
102 "error %ld reading directory block "
103 "(ino %lu, block %lu)", PTR_ERR(bh), inode->i_ino,
104 (unsigned long) block);
105
106 return bh;
107 }
108 if (!bh) {
109 ext4_error_inode(inode, __func__, line, block, "Directory hole found");
110 return ERR_PTR(-EIO);
111 }
112 dirent = (struct ext4_dir_entry *) bh->b_data;
113 /* Determine whether or not we have an index block */
114 if (is_dx(inode)) {
115 if (block == 0)
116 is_dx_block = 1;
117 else if (ext4_rec_len_from_disk(dirent->rec_len,
118 inode->i_sb->s_blocksize) ==
119 inode->i_sb->s_blocksize)
120 is_dx_block = 1;
121 }
122 if (!is_dx_block && type == INDEX) {
123 ext4_error_inode(inode, __func__, line, block,
124 "directory leaf block found instead of index block");
125 return ERR_PTR(-EIO);
126 }
127 if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
128 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) ||
129 buffer_verified(bh))
130 return bh;
131
132 /*
133 * An empty leaf block can get mistaken for a index block; for
134 * this reason, we can only check the index checksum when the
135 * caller is sure it should be an index block.
136 */
137 if (is_dx_block && type == INDEX) {
138 if (ext4_dx_csum_verify(inode, dirent))
139 set_buffer_verified(bh);
140 else {
141 ext4_error_inode(inode, __func__, line, block,
142 "Directory index failed checksum");
143 brelse(bh);
144 return ERR_PTR(-EIO);
145 }
146 }
147 if (!is_dx_block) {
148 if (ext4_dirent_csum_verify(inode, dirent))
149 set_buffer_verified(bh);
150 else {
151 ext4_error_inode(inode, __func__, line, block,
152 "Directory block failed checksum");
153 brelse(bh);
154 return ERR_PTR(-EIO);
155 }
156 }
157 return bh;
158 }
159
160 #ifndef assert
161 #define assert(test) J_ASSERT(test)
162 #endif
163
164 #ifdef DX_DEBUG
165 #define dxtrace(command) command
166 #else
167 #define dxtrace(command)
168 #endif
169
170 struct fake_dirent
171 {
172 __le32 inode;
173 __le16 rec_len;
174 u8 name_len;
175 u8 file_type;
176 };
177
178 struct dx_countlimit
179 {
180 __le16 limit;
181 __le16 count;
182 };
183
184 struct dx_entry
185 {
186 __le32 hash;
187 __le32 block;
188 };
189
190 /*
191 * dx_root_info is laid out so that if it should somehow get overlaid by a
192 * dirent the two low bits of the hash version will be zero. Therefore, the
193 * hash version mod 4 should never be 0. Sincerely, the paranoia department.
194 */
195
196 struct dx_root
197 {
198 struct fake_dirent dot;
199 char dot_name[4];
200 struct fake_dirent dotdot;
201 char dotdot_name[4];
202 struct dx_root_info
203 {
204 __le32 reserved_zero;
205 u8 hash_version;
206 u8 info_length; /* 8 */
207 u8 indirect_levels;
208 u8 unused_flags;
209 }
210 info;
211 struct dx_entry entries[0];
212 };
213
214 struct dx_node
215 {
216 struct fake_dirent fake;
217 struct dx_entry entries[0];
218 };
219
220
221 struct dx_frame
222 {
223 struct buffer_head *bh;
224 struct dx_entry *entries;
225 struct dx_entry *at;
226 };
227
228 struct dx_map_entry
229 {
230 u32 hash;
231 u16 offs;
232 u16 size;
233 };
234
235 /*
236 * This goes at the end of each htree block.
237 */
238 struct dx_tail {
239 u32 dt_reserved;
240 __le32 dt_checksum; /* crc32c(uuid+inum+dirblock) */
241 };
242
243 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
244 static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
245 static inline unsigned dx_get_hash(struct dx_entry *entry);
246 static void dx_set_hash(struct dx_entry *entry, unsigned value);
247 static unsigned dx_get_count(struct dx_entry *entries);
248 static unsigned dx_get_limit(struct dx_entry *entries);
249 static void dx_set_count(struct dx_entry *entries, unsigned value);
250 static void dx_set_limit(struct dx_entry *entries, unsigned value);
251 static unsigned dx_root_limit(struct inode *dir, unsigned infosize);
252 static unsigned dx_node_limit(struct inode *dir);
253 static struct dx_frame *dx_probe(const struct qstr *d_name,
254 struct inode *dir,
255 struct dx_hash_info *hinfo,
256 struct dx_frame *frame);
257 static void dx_release(struct dx_frame *frames);
258 static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize,
259 struct dx_hash_info *hinfo, struct dx_map_entry map[]);
260 static void dx_sort_map(struct dx_map_entry *map, unsigned count);
261 static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to,
262 struct dx_map_entry *offsets, int count, unsigned blocksize);
263 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize);
264 static void dx_insert_block(struct dx_frame *frame,
265 u32 hash, ext4_lblk_t block);
266 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
267 struct dx_frame *frame,
268 struct dx_frame *frames,
269 __u32 *start_hash);
270 static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
271 const struct qstr *d_name,
272 struct ext4_dir_entry_2 **res_dir);
273 static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
274 struct inode *inode);
275
276 /* checksumming functions */
277 void initialize_dirent_tail(struct ext4_dir_entry_tail *t,
278 unsigned int blocksize)
279 {
280 memset(t, 0, sizeof(struct ext4_dir_entry_tail));
281 t->det_rec_len = ext4_rec_len_to_disk(
282 sizeof(struct ext4_dir_entry_tail), blocksize);
283 t->det_reserved_ft = EXT4_FT_DIR_CSUM;
284 }
285
286 /* Walk through a dirent block to find a checksum "dirent" at the tail */
287 static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode,
288 struct ext4_dir_entry *de)
289 {
290 struct ext4_dir_entry_tail *t;
291
292 #ifdef PARANOID
293 struct ext4_dir_entry *d, *top;
294
295 d = de;
296 top = (struct ext4_dir_entry *)(((void *)de) +
297 (EXT4_BLOCK_SIZE(inode->i_sb) -
298 sizeof(struct ext4_dir_entry_tail)));
299 while (d < top && d->rec_len)
300 d = (struct ext4_dir_entry *)(((void *)d) +
301 le16_to_cpu(d->rec_len));
302
303 if (d != top)
304 return NULL;
305
306 t = (struct ext4_dir_entry_tail *)d;
307 #else
308 t = EXT4_DIRENT_TAIL(de, EXT4_BLOCK_SIZE(inode->i_sb));
309 #endif
310
311 if (t->det_reserved_zero1 ||
312 le16_to_cpu(t->det_rec_len) != sizeof(struct ext4_dir_entry_tail) ||
313 t->det_reserved_zero2 ||
314 t->det_reserved_ft != EXT4_FT_DIR_CSUM)
315 return NULL;
316
317 return t;
318 }
319
320 static __le32 ext4_dirent_csum(struct inode *inode,
321 struct ext4_dir_entry *dirent, int size)
322 {
323 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
324 struct ext4_inode_info *ei = EXT4_I(inode);
325 __u32 csum;
326
327 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
328 return cpu_to_le32(csum);
329 }
330
331 static void warn_no_space_for_csum(struct inode *inode)
332 {
333 ext4_warning(inode->i_sb, "no space in directory inode %lu leaf for "
334 "checksum. Please run e2fsck -D.", inode->i_ino);
335 }
336
337 int ext4_dirent_csum_verify(struct inode *inode, struct ext4_dir_entry *dirent)
338 {
339 struct ext4_dir_entry_tail *t;
340
341 if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
342 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
343 return 1;
344
345 t = get_dirent_tail(inode, dirent);
346 if (!t) {
347 warn_no_space_for_csum(inode);
348 return 0;
349 }
350
351 if (t->det_checksum != ext4_dirent_csum(inode, dirent,
352 (void *)t - (void *)dirent))
353 return 0;
354
355 return 1;
356 }
357
358 static void ext4_dirent_csum_set(struct inode *inode,
359 struct ext4_dir_entry *dirent)
360 {
361 struct ext4_dir_entry_tail *t;
362
363 if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
364 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
365 return;
366
367 t = get_dirent_tail(inode, dirent);
368 if (!t) {
369 warn_no_space_for_csum(inode);
370 return;
371 }
372
373 t->det_checksum = ext4_dirent_csum(inode, dirent,
374 (void *)t - (void *)dirent);
375 }
376
377 int ext4_handle_dirty_dirent_node(handle_t *handle,
378 struct inode *inode,
379 struct buffer_head *bh)
380 {
381 ext4_dirent_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
382 return ext4_handle_dirty_metadata(handle, inode, bh);
383 }
384
385 static struct dx_countlimit *get_dx_countlimit(struct inode *inode,
386 struct ext4_dir_entry *dirent,
387 int *offset)
388 {
389 struct ext4_dir_entry *dp;
390 struct dx_root_info *root;
391 int count_offset;
392
393 if (le16_to_cpu(dirent->rec_len) == EXT4_BLOCK_SIZE(inode->i_sb))
394 count_offset = 8;
395 else if (le16_to_cpu(dirent->rec_len) == 12) {
396 dp = (struct ext4_dir_entry *)(((void *)dirent) + 12);
397 if (le16_to_cpu(dp->rec_len) !=
398 EXT4_BLOCK_SIZE(inode->i_sb) - 12)
399 return NULL;
400 root = (struct dx_root_info *)(((void *)dp + 12));
401 if (root->reserved_zero ||
402 root->info_length != sizeof(struct dx_root_info))
403 return NULL;
404 count_offset = 32;
405 } else
406 return NULL;
407
408 if (offset)
409 *offset = count_offset;
410 return (struct dx_countlimit *)(((void *)dirent) + count_offset);
411 }
412
413 static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent,
414 int count_offset, int count, struct dx_tail *t)
415 {
416 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
417 struct ext4_inode_info *ei = EXT4_I(inode);
418 __u32 csum;
419 __le32 save_csum;
420 int size;
421
422 size = count_offset + (count * sizeof(struct dx_entry));
423 save_csum = t->dt_checksum;
424 t->dt_checksum = 0;
425 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
426 csum = ext4_chksum(sbi, csum, (__u8 *)t, sizeof(struct dx_tail));
427 t->dt_checksum = save_csum;
428
429 return cpu_to_le32(csum);
430 }
431
432 static int ext4_dx_csum_verify(struct inode *inode,
433 struct ext4_dir_entry *dirent)
434 {
435 struct dx_countlimit *c;
436 struct dx_tail *t;
437 int count_offset, limit, count;
438
439 if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
440 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
441 return 1;
442
443 c = get_dx_countlimit(inode, dirent, &count_offset);
444 if (!c) {
445 EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D.");
446 return 1;
447 }
448 limit = le16_to_cpu(c->limit);
449 count = le16_to_cpu(c->count);
450 if (count_offset + (limit * sizeof(struct dx_entry)) >
451 EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
452 warn_no_space_for_csum(inode);
453 return 1;
454 }
455 t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
456
457 if (t->dt_checksum != ext4_dx_csum(inode, dirent, count_offset,
458 count, t))
459 return 0;
460 return 1;
461 }
462
463 static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent)
464 {
465 struct dx_countlimit *c;
466 struct dx_tail *t;
467 int count_offset, limit, count;
468
469 if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
470 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
471 return;
472
473 c = get_dx_countlimit(inode, dirent, &count_offset);
474 if (!c) {
475 EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D.");
476 return;
477 }
478 limit = le16_to_cpu(c->limit);
479 count = le16_to_cpu(c->count);
480 if (count_offset + (limit * sizeof(struct dx_entry)) >
481 EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
482 warn_no_space_for_csum(inode);
483 return;
484 }
485 t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
486
487 t->dt_checksum = ext4_dx_csum(inode, dirent, count_offset, count, t);
488 }
489
490 static inline int ext4_handle_dirty_dx_node(handle_t *handle,
491 struct inode *inode,
492 struct buffer_head *bh)
493 {
494 ext4_dx_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
495 return ext4_handle_dirty_metadata(handle, inode, bh);
496 }
497
498 /*
499 * p is at least 6 bytes before the end of page
500 */
501 static inline struct ext4_dir_entry_2 *
502 ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
503 {
504 return (struct ext4_dir_entry_2 *)((char *)p +
505 ext4_rec_len_from_disk(p->rec_len, blocksize));
506 }
507
508 /*
509 * Future: use high four bits of block for coalesce-on-delete flags
510 * Mask them off for now.
511 */
512
513 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
514 {
515 return le32_to_cpu(entry->block) & 0x00ffffff;
516 }
517
518 static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
519 {
520 entry->block = cpu_to_le32(value);
521 }
522
523 static inline unsigned dx_get_hash(struct dx_entry *entry)
524 {
525 return le32_to_cpu(entry->hash);
526 }
527
528 static inline void dx_set_hash(struct dx_entry *entry, unsigned value)
529 {
530 entry->hash = cpu_to_le32(value);
531 }
532
533 static inline unsigned dx_get_count(struct dx_entry *entries)
534 {
535 return le16_to_cpu(((struct dx_countlimit *) entries)->count);
536 }
537
538 static inline unsigned dx_get_limit(struct dx_entry *entries)
539 {
540 return le16_to_cpu(((struct dx_countlimit *) entries)->limit);
541 }
542
543 static inline void dx_set_count(struct dx_entry *entries, unsigned value)
544 {
545 ((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
546 }
547
548 static inline void dx_set_limit(struct dx_entry *entries, unsigned value)
549 {
550 ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
551 }
552
553 static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
554 {
555 unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
556 EXT4_DIR_REC_LEN(2) - infosize;
557
558 if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
559 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
560 entry_space -= sizeof(struct dx_tail);
561 return entry_space / sizeof(struct dx_entry);
562 }
563
564 static inline unsigned dx_node_limit(struct inode *dir)
565 {
566 unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);
567
568 if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
569 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
570 entry_space -= sizeof(struct dx_tail);
571 return entry_space / sizeof(struct dx_entry);
572 }
573
574 /*
575 * Debug
576 */
577 #ifdef DX_DEBUG
578 static void dx_show_index(char * label, struct dx_entry *entries)
579 {
580 int i, n = dx_get_count (entries);
581 printk(KERN_DEBUG "%s index ", label);
582 for (i = 0; i < n; i++) {
583 printk("%x->%lu ", i ? dx_get_hash(entries + i) :
584 0, (unsigned long)dx_get_block(entries + i));
585 }
586 printk("\n");
587 }
588
589 struct stats
590 {
591 unsigned names;
592 unsigned space;
593 unsigned bcount;
594 };
595
596 static struct stats dx_show_leaf(struct dx_hash_info *hinfo, struct ext4_dir_entry_2 *de,
597 int size, int show_names)
598 {
599 unsigned names = 0, space = 0;
600 char *base = (char *) de;
601 struct dx_hash_info h = *hinfo;
602
603 printk("names: ");
604 while ((char *) de < base + size)
605 {
606 if (de->inode)
607 {
608 if (show_names)
609 {
610 int len = de->name_len;
611 char *name = de->name;
612 while (len--) printk("%c", *name++);
613 ext4fs_dirhash(de->name, de->name_len, &h);
614 printk(":%x.%u ", h.hash,
615 (unsigned) ((char *) de - base));
616 }
617 space += EXT4_DIR_REC_LEN(de->name_len);
618 names++;
619 }
620 de = ext4_next_entry(de, size);
621 }
622 printk("(%i)\n", names);
623 return (struct stats) { names, space, 1 };
624 }
625
626 struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
627 struct dx_entry *entries, int levels)
628 {
629 unsigned blocksize = dir->i_sb->s_blocksize;
630 unsigned count = dx_get_count(entries), names = 0, space = 0, i;
631 unsigned bcount = 0;
632 struct buffer_head *bh;
633 int err;
634 printk("%i indexed blocks...\n", count);
635 for (i = 0; i < count; i++, entries++)
636 {
637 ext4_lblk_t block = dx_get_block(entries);
638 ext4_lblk_t hash = i ? dx_get_hash(entries): 0;
639 u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
640 struct stats stats;
641 printk("%s%3u:%03u hash %8x/%8x ",levels?"":" ", i, block, hash, range);
642 bh = ext4_bread(NULL,dir, block, 0);
643 if (!bh || IS_ERR(bh))
644 continue;
645 stats = levels?
646 dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
647 dx_show_leaf(hinfo, (struct ext4_dir_entry_2 *) bh->b_data, blocksize, 0);
648 names += stats.names;
649 space += stats.space;
650 bcount += stats.bcount;
651 brelse(bh);
652 }
653 if (bcount)
654 printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n",
655 levels ? "" : " ", names, space/bcount,
656 (space/bcount)*100/blocksize);
657 return (struct stats) { names, space, bcount};
658 }
659 #endif /* DX_DEBUG */
660
661 /*
662 * Probe for a directory leaf block to search.
663 *
664 * dx_probe can return ERR_BAD_DX_DIR, which means there was a format
665 * error in the directory index, and the caller should fall back to
666 * searching the directory normally. The callers of dx_probe **MUST**
667 * check for this error code, and make sure it never gets reflected
668 * back to userspace.
669 */
670 static struct dx_frame *
671 dx_probe(const struct qstr *d_name, struct inode *dir,
672 struct dx_hash_info *hinfo, struct dx_frame *frame_in)
673 {
674 unsigned count, indirect;
675 struct dx_entry *at, *entries, *p, *q, *m;
676 struct dx_root *root;
677 struct dx_frame *frame = frame_in;
678 struct dx_frame *ret_err = ERR_PTR(ERR_BAD_DX_DIR);
679 u32 hash;
680
681 frame->bh = ext4_read_dirblock(dir, 0, INDEX);
682 if (IS_ERR(frame->bh))
683 return (struct dx_frame *) frame->bh;
684
685 root = (struct dx_root *) frame->bh->b_data;
686 if (root->info.hash_version != DX_HASH_TEA &&
687 root->info.hash_version != DX_HASH_HALF_MD4 &&
688 root->info.hash_version != DX_HASH_LEGACY) {
689 ext4_warning(dir->i_sb, "Unrecognised inode hash code %d",
690 root->info.hash_version);
691 goto fail;
692 }
693 hinfo->hash_version = root->info.hash_version;
694 if (hinfo->hash_version <= DX_HASH_TEA)
695 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
696 hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
697 if (d_name)
698 ext4fs_dirhash(d_name->name, d_name->len, hinfo);
699 hash = hinfo->hash;
700
701 if (root->info.unused_flags & 1) {
702 ext4_warning(dir->i_sb, "Unimplemented inode hash flags: %#06x",
703 root->info.unused_flags);
704 goto fail;
705 }
706
707 if ((indirect = root->info.indirect_levels) > 1) {
708 ext4_warning(dir->i_sb, "Unimplemented inode hash depth: %#06x",
709 root->info.indirect_levels);
710 goto fail;
711 }
712
713 entries = (struct dx_entry *) (((char *)&root->info) +
714 root->info.info_length);
715
716 if (dx_get_limit(entries) != dx_root_limit(dir,
717 root->info.info_length)) {
718 ext4_warning(dir->i_sb, "dx entry: limit != root limit");
719 goto fail;
720 }
721
722 dxtrace(printk("Look up %x", hash));
723 while (1) {
724 count = dx_get_count(entries);
725 if (!count || count > dx_get_limit(entries)) {
726 ext4_warning(dir->i_sb,
727 "dx entry: no count or count > limit");
728 goto fail;
729 }
730
731 p = entries + 1;
732 q = entries + count - 1;
733 while (p <= q) {
734 m = p + (q - p)/2;
735 dxtrace(printk("."));
736 if (dx_get_hash(m) > hash)
737 q = m - 1;
738 else
739 p = m + 1;
740 }
741
742 if (0) { // linear search cross check
743 unsigned n = count - 1;
744 at = entries;
745 while (n--)
746 {
747 dxtrace(printk(","));
748 if (dx_get_hash(++at) > hash)
749 {
750 at--;
751 break;
752 }
753 }
754 assert (at == p - 1);
755 }
756
757 at = p - 1;
758 dxtrace(printk(" %x->%u\n", at == entries? 0: dx_get_hash(at), dx_get_block(at)));
759 frame->entries = entries;
760 frame->at = at;
761 if (!indirect--)
762 return frame;
763 frame++;
764 frame->bh = ext4_read_dirblock(dir, dx_get_block(at), INDEX);
765 if (IS_ERR(frame->bh)) {
766 ret_err = (struct dx_frame *) frame->bh;
767 frame->bh = NULL;
768 goto fail;
769 }
770 entries = ((struct dx_node *) frame->bh->b_data)->entries;
771
772 if (dx_get_limit(entries) != dx_node_limit (dir)) {
773 ext4_warning(dir->i_sb,
774 "dx entry: limit != node limit");
775 goto fail;
776 }
777 }
778 fail:
779 while (frame >= frame_in) {
780 brelse(frame->bh);
781 frame--;
782 }
783 if (ret_err == ERR_PTR(ERR_BAD_DX_DIR))
784 ext4_warning(dir->i_sb,
785 "Corrupt dir inode %lu, running e2fsck is "
786 "recommended.", dir->i_ino);
787 return ret_err;
788 }
789
790 static void dx_release (struct dx_frame *frames)
791 {
792 if (frames[0].bh == NULL)
793 return;
794
795 if (((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels)
796 brelse(frames[1].bh);
797 brelse(frames[0].bh);
798 }
799
800 /*
801 * This function increments the frame pointer to search the next leaf
802 * block, and reads in the necessary intervening nodes if the search
803 * should be necessary. Whether or not the search is necessary is
804 * controlled by the hash parameter. If the hash value is even, then
805 * the search is only continued if the next block starts with that
806 * hash value. This is used if we are searching for a specific file.
807 *
808 * If the hash value is HASH_NB_ALWAYS, then always go to the next block.
809 *
810 * This function returns 1 if the caller should continue to search,
811 * or 0 if it should not. If there is an error reading one of the
812 * index blocks, it will a negative error code.
813 *
814 * If start_hash is non-null, it will be filled in with the starting
815 * hash of the next page.
816 */
817 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
818 struct dx_frame *frame,
819 struct dx_frame *frames,
820 __u32 *start_hash)
821 {
822 struct dx_frame *p;
823 struct buffer_head *bh;
824 int num_frames = 0;
825 __u32 bhash;
826
827 p = frame;
828 /*
829 * Find the next leaf page by incrementing the frame pointer.
830 * If we run out of entries in the interior node, loop around and
831 * increment pointer in the parent node. When we break out of
832 * this loop, num_frames indicates the number of interior
833 * nodes need to be read.
834 */
835 while (1) {
836 if (++(p->at) < p->entries + dx_get_count(p->entries))
837 break;
838 if (p == frames)
839 return 0;
840 num_frames++;
841 p--;
842 }
843
844 /*
845 * If the hash is 1, then continue only if the next page has a
846 * continuation hash of any value. This is used for readdir
847 * handling. Otherwise, check to see if the hash matches the
848 * desired contiuation hash. If it doesn't, return since
849 * there's no point to read in the successive index pages.
850 */
851 bhash = dx_get_hash(p->at);
852 if (start_hash)
853 *start_hash = bhash;
854 if ((hash & 1) == 0) {
855 if ((bhash & ~1) != hash)
856 return 0;
857 }
858 /*
859 * If the hash is HASH_NB_ALWAYS, we always go to the next
860 * block so no check is necessary
861 */
862 while (num_frames--) {
863 bh = ext4_read_dirblock(dir, dx_get_block(p->at), INDEX);
864 if (IS_ERR(bh))
865 return PTR_ERR(bh);
866 p++;
867 brelse(p->bh);
868 p->bh = bh;
869 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
870 }
871 return 1;
872 }
873
874
875 /*
876 * This function fills a red-black tree with information from a
877 * directory block. It returns the number directory entries loaded
878 * into the tree. If there is an error it is returned in err.
879 */
880 static int htree_dirblock_to_tree(struct file *dir_file,
881 struct inode *dir, ext4_lblk_t block,
882 struct dx_hash_info *hinfo,
883 __u32 start_hash, __u32 start_minor_hash)
884 {
885 struct buffer_head *bh;
886 struct ext4_dir_entry_2 *de, *top;
887 int err = 0, count = 0;
888
889 dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
890 (unsigned long)block));
891 bh = ext4_read_dirblock(dir, block, DIRENT);
892 if (IS_ERR(bh))
893 return PTR_ERR(bh);
894
895 de = (struct ext4_dir_entry_2 *) bh->b_data;
896 top = (struct ext4_dir_entry_2 *) ((char *) de +
897 dir->i_sb->s_blocksize -
898 EXT4_DIR_REC_LEN(0));
899 for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) {
900 if (ext4_check_dir_entry(dir, NULL, de, bh,
901 bh->b_data, bh->b_size,
902 (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
903 + ((char *)de - bh->b_data))) {
904 /* silently ignore the rest of the block */
905 break;
906 }
907 ext4fs_dirhash(de->name, de->name_len, hinfo);
908 if ((hinfo->hash < start_hash) ||
909 ((hinfo->hash == start_hash) &&
910 (hinfo->minor_hash < start_minor_hash)))
911 continue;
912 if (de->inode == 0)
913 continue;
914 if ((err = ext4_htree_store_dirent(dir_file,
915 hinfo->hash, hinfo->minor_hash, de)) != 0) {
916 brelse(bh);
917 return err;
918 }
919 count++;
920 }
921 brelse(bh);
922 return count;
923 }
924
925
926 /*
927 * This function fills a red-black tree with information from a
928 * directory. We start scanning the directory in hash order, starting
929 * at start_hash and start_minor_hash.
930 *
931 * This function returns the number of entries inserted into the tree,
932 * or a negative error code.
933 */
934 int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
935 __u32 start_minor_hash, __u32 *next_hash)
936 {
937 struct dx_hash_info hinfo;
938 struct ext4_dir_entry_2 *de;
939 struct dx_frame frames[2], *frame;
940 struct inode *dir;
941 ext4_lblk_t block;
942 int count = 0;
943 int ret, err;
944 __u32 hashval;
945
946 dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
947 start_hash, start_minor_hash));
948 dir = file_inode(dir_file);
949 if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) {
950 hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
951 if (hinfo.hash_version <= DX_HASH_TEA)
952 hinfo.hash_version +=
953 EXT4_SB(dir->i_sb)->s_hash_unsigned;
954 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
955 if (ext4_has_inline_data(dir)) {
956 int has_inline_data = 1;
957 count = htree_inlinedir_to_tree(dir_file, dir, 0,
958 &hinfo, start_hash,
959 start_minor_hash,
960 &has_inline_data);
961 if (has_inline_data) {
962 *next_hash = ~0;
963 return count;
964 }
965 }
966 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
967 start_hash, start_minor_hash);
968 *next_hash = ~0;
969 return count;
970 }
971 hinfo.hash = start_hash;
972 hinfo.minor_hash = 0;
973 frame = dx_probe(NULL, dir, &hinfo, frames);
974 if (IS_ERR(frame))
975 return PTR_ERR(frame);
976
977 /* Add '.' and '..' from the htree header */
978 if (!start_hash && !start_minor_hash) {
979 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
980 if ((err = ext4_htree_store_dirent(dir_file, 0, 0, de)) != 0)
981 goto errout;
982 count++;
983 }
984 if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
985 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
986 de = ext4_next_entry(de, dir->i_sb->s_blocksize);
987 if ((err = ext4_htree_store_dirent(dir_file, 2, 0, de)) != 0)
988 goto errout;
989 count++;
990 }
991
992 while (1) {
993 block = dx_get_block(frame->at);
994 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
995 start_hash, start_minor_hash);
996 if (ret < 0) {
997 err = ret;
998 goto errout;
999 }
1000 count += ret;
1001 hashval = ~0;
1002 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
1003 frame, frames, &hashval);
1004 *next_hash = hashval;
1005 if (ret < 0) {
1006 err = ret;
1007 goto errout;
1008 }
1009 /*
1010 * Stop if: (a) there are no more entries, or
1011 * (b) we have inserted at least one entry and the
1012 * next hash value is not a continuation
1013 */
1014 if ((ret == 0) ||
1015 (count && ((hashval & 1) == 0)))
1016 break;
1017 }
1018 dx_release(frames);
1019 dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, "
1020 "next hash: %x\n", count, *next_hash));
1021 return count;
1022 errout:
1023 dx_release(frames);
1024 return (err);
1025 }
1026
1027 static inline int search_dirblock(struct buffer_head *bh,
1028 struct inode *dir,
1029 const struct qstr *d_name,
1030 unsigned int offset,
1031 struct ext4_dir_entry_2 **res_dir)
1032 {
1033 return search_dir(bh, bh->b_data, dir->i_sb->s_blocksize, dir,
1034 d_name, offset, res_dir);
1035 }
1036
1037 /*
1038 * Directory block splitting, compacting
1039 */
1040
1041 /*
1042 * Create map of hash values, offsets, and sizes, stored at end of block.
1043 * Returns number of entries mapped.
1044 */
1045 static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize,
1046 struct dx_hash_info *hinfo,
1047 struct dx_map_entry *map_tail)
1048 {
1049 int count = 0;
1050 char *base = (char *) de;
1051 struct dx_hash_info h = *hinfo;
1052
1053 while ((char *) de < base + blocksize) {
1054 if (de->name_len && de->inode) {
1055 ext4fs_dirhash(de->name, de->name_len, &h);
1056 map_tail--;
1057 map_tail->hash = h.hash;
1058 map_tail->offs = ((char *) de - base)>>2;
1059 map_tail->size = le16_to_cpu(de->rec_len);
1060 count++;
1061 cond_resched();
1062 }
1063 /* XXX: do we need to check rec_len == 0 case? -Chris */
1064 de = ext4_next_entry(de, blocksize);
1065 }
1066 return count;
1067 }
1068
1069 /* Sort map by hash value */
1070 static void dx_sort_map (struct dx_map_entry *map, unsigned count)
1071 {
1072 struct dx_map_entry *p, *q, *top = map + count - 1;
1073 int more;
1074 /* Combsort until bubble sort doesn't suck */
1075 while (count > 2) {
1076 count = count*10/13;
1077 if (count - 9 < 2) /* 9, 10 -> 11 */
1078 count = 11;
1079 for (p = top, q = p - count; q >= map; p--, q--)
1080 if (p->hash < q->hash)
1081 swap(*p, *q);
1082 }
1083 /* Garden variety bubble sort */
1084 do {
1085 more = 0;
1086 q = top;
1087 while (q-- > map) {
1088 if (q[1].hash >= q[0].hash)
1089 continue;
1090 swap(*(q+1), *q);
1091 more = 1;
1092 }
1093 } while(more);
1094 }
1095
1096 static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
1097 {
1098 struct dx_entry *entries = frame->entries;
1099 struct dx_entry *old = frame->at, *new = old + 1;
1100 int count = dx_get_count(entries);
1101
1102 assert(count < dx_get_limit(entries));
1103 assert(old < entries + count);
1104 memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
1105 dx_set_hash(new, hash);
1106 dx_set_block(new, block);
1107 dx_set_count(entries, count + 1);
1108 }
1109
1110 /*
1111 * NOTE! unlike strncmp, ext4_match returns 1 for success, 0 for failure.
1112 *
1113 * `len <= EXT4_NAME_LEN' is guaranteed by caller.
1114 * `de != NULL' is guaranteed by caller.
1115 */
1116 static inline int ext4_match (int len, const char * const name,
1117 struct ext4_dir_entry_2 * de)
1118 {
1119 if (len != de->name_len)
1120 return 0;
1121 if (!de->inode)
1122 return 0;
1123 return !memcmp(name, de->name, len);
1124 }
1125
1126 /*
1127 * Returns 0 if not found, -1 on failure, and 1 on success
1128 */
1129 int search_dir(struct buffer_head *bh,
1130 char *search_buf,
1131 int buf_size,
1132 struct inode *dir,
1133 const struct qstr *d_name,
1134 unsigned int offset,
1135 struct ext4_dir_entry_2 **res_dir)
1136 {
1137 struct ext4_dir_entry_2 * de;
1138 char * dlimit;
1139 int de_len;
1140 const char *name = d_name->name;
1141 int namelen = d_name->len;
1142
1143 de = (struct ext4_dir_entry_2 *)search_buf;
1144 dlimit = search_buf + buf_size;
1145 while ((char *) de < dlimit) {
1146 /* this code is executed quadratically often */
1147 /* do minimal checking `by hand' */
1148
1149 if ((char *) de + namelen <= dlimit &&
1150 ext4_match (namelen, name, de)) {
1151 /* found a match - just to be sure, do a full check */
1152 if (ext4_check_dir_entry(dir, NULL, de, bh, bh->b_data,
1153 bh->b_size, offset))
1154 return -1;
1155 *res_dir = de;
1156 return 1;
1157 }
1158 /* prevent looping on a bad block */
1159 de_len = ext4_rec_len_from_disk(de->rec_len,
1160 dir->i_sb->s_blocksize);
1161 if (de_len <= 0)
1162 return -1;
1163 offset += de_len;
1164 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
1165 }
1166 return 0;
1167 }
1168
1169 static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block,
1170 struct ext4_dir_entry *de)
1171 {
1172 struct super_block *sb = dir->i_sb;
1173
1174 if (!is_dx(dir))
1175 return 0;
1176 if (block == 0)
1177 return 1;
1178 if (de->inode == 0 &&
1179 ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) ==
1180 sb->s_blocksize)
1181 return 1;
1182 return 0;
1183 }
1184
1185 /*
1186 * ext4_find_entry()
1187 *
1188 * finds an entry in the specified directory with the wanted name. It
1189 * returns the cache buffer in which the entry was found, and the entry
1190 * itself (as a parameter - res_dir). It does NOT read the inode of the
1191 * entry - you'll have to do that yourself if you want to.
1192 *
1193 * The returned buffer_head has ->b_count elevated. The caller is expected
1194 * to brelse() it when appropriate.
1195 */
1196 static struct buffer_head * ext4_find_entry (struct inode *dir,
1197 const struct qstr *d_name,
1198 struct ext4_dir_entry_2 **res_dir,
1199 int *inlined)
1200 {
1201 struct super_block *sb;
1202 struct buffer_head *bh_use[NAMEI_RA_SIZE];
1203 struct buffer_head *bh, *ret = NULL;
1204 ext4_lblk_t start, block, b;
1205 const u8 *name = d_name->name;
1206 int ra_max = 0; /* Number of bh's in the readahead
1207 buffer, bh_use[] */
1208 int ra_ptr = 0; /* Current index into readahead
1209 buffer */
1210 int num = 0;
1211 ext4_lblk_t nblocks;
1212 int i, namelen;
1213
1214 *res_dir = NULL;
1215 sb = dir->i_sb;
1216 namelen = d_name->len;
1217 if (namelen > EXT4_NAME_LEN)
1218 return NULL;
1219
1220 if (ext4_has_inline_data(dir)) {
1221 int has_inline_data = 1;
1222 ret = ext4_find_inline_entry(dir, d_name, res_dir,
1223 &has_inline_data);
1224 if (has_inline_data) {
1225 if (inlined)
1226 *inlined = 1;
1227 return ret;
1228 }
1229 }
1230
1231 if ((namelen <= 2) && (name[0] == '.') &&
1232 (name[1] == '.' || name[1] == '\0')) {
1233 /*
1234 * "." or ".." will only be in the first block
1235 * NFS may look up ".."; "." should be handled by the VFS
1236 */
1237 block = start = 0;
1238 nblocks = 1;
1239 goto restart;
1240 }
1241 if (is_dx(dir)) {
1242 bh = ext4_dx_find_entry(dir, d_name, res_dir);
1243 /*
1244 * On success, or if the error was file not found,
1245 * return. Otherwise, fall back to doing a search the
1246 * old fashioned way.
1247 */
1248 if (!IS_ERR(bh) || PTR_ERR(bh) != ERR_BAD_DX_DIR)
1249 return bh;
1250 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
1251 "falling back\n"));
1252 }
1253 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1254 start = EXT4_I(dir)->i_dir_start_lookup;
1255 if (start >= nblocks)
1256 start = 0;
1257 block = start;
1258 restart:
1259 do {
1260 /*
1261 * We deal with the read-ahead logic here.
1262 */
1263 if (ra_ptr >= ra_max) {
1264 /* Refill the readahead buffer */
1265 ra_ptr = 0;
1266 b = block;
1267 for (ra_max = 0; ra_max < NAMEI_RA_SIZE; ra_max++) {
1268 /*
1269 * Terminate if we reach the end of the
1270 * directory and must wrap, or if our
1271 * search has finished at this block.
1272 */
1273 if (b >= nblocks || (num && block == start)) {
1274 bh_use[ra_max] = NULL;
1275 break;
1276 }
1277 num++;
1278 bh = ext4_getblk(NULL, dir, b++, 0);
1279 if (unlikely(IS_ERR(bh))) {
1280 if (ra_max == 0)
1281 return bh;
1282 break;
1283 }
1284 bh_use[ra_max] = bh;
1285 if (bh)
1286 ll_rw_block(READ | REQ_META | REQ_PRIO,
1287 1, &bh);
1288 }
1289 }
1290 if ((bh = bh_use[ra_ptr++]) == NULL)
1291 goto next;
1292 wait_on_buffer(bh);
1293 if (!buffer_uptodate(bh)) {
1294 /* read error, skip block & hope for the best */
1295 EXT4_ERROR_INODE(dir, "reading directory lblock %lu",
1296 (unsigned long) block);
1297 brelse(bh);
1298 goto next;
1299 }
1300 if (!buffer_verified(bh) &&
1301 !is_dx_internal_node(dir, block,
1302 (struct ext4_dir_entry *)bh->b_data) &&
1303 !ext4_dirent_csum_verify(dir,
1304 (struct ext4_dir_entry *)bh->b_data)) {
1305 EXT4_ERROR_INODE(dir, "checksumming directory "
1306 "block %lu", (unsigned long)block);
1307 brelse(bh);
1308 goto next;
1309 }
1310 set_buffer_verified(bh);
1311 i = search_dirblock(bh, dir, d_name,
1312 block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
1313 if (i == 1) {
1314 EXT4_I(dir)->i_dir_start_lookup = block;
1315 ret = bh;
1316 goto cleanup_and_exit;
1317 } else {
1318 brelse(bh);
1319 if (i < 0)
1320 goto cleanup_and_exit;
1321 }
1322 next:
1323 if (++block >= nblocks)
1324 block = 0;
1325 } while (block != start);
1326
1327 /*
1328 * If the directory has grown while we were searching, then
1329 * search the last part of the directory before giving up.
1330 */
1331 block = nblocks;
1332 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1333 if (block < nblocks) {
1334 start = 0;
1335 goto restart;
1336 }
1337
1338 cleanup_and_exit:
1339 /* Clean up the read-ahead blocks */
1340 for (; ra_ptr < ra_max; ra_ptr++)
1341 brelse(bh_use[ra_ptr]);
1342 return ret;
1343 }
1344
1345 static struct buffer_head * ext4_dx_find_entry(struct inode *dir, const struct qstr *d_name,
1346 struct ext4_dir_entry_2 **res_dir)
1347 {
1348 struct super_block * sb = dir->i_sb;
1349 struct dx_hash_info hinfo;
1350 struct dx_frame frames[2], *frame;
1351 struct buffer_head *bh;
1352 ext4_lblk_t block;
1353 int retval;
1354
1355 frame = dx_probe(d_name, dir, &hinfo, frames);
1356 if (IS_ERR(frame))
1357 return (struct buffer_head *) frame;
1358 do {
1359 block = dx_get_block(frame->at);
1360 bh = ext4_read_dirblock(dir, block, DIRENT);
1361 if (IS_ERR(bh))
1362 goto errout;
1363
1364 retval = search_dirblock(bh, dir, d_name,
1365 block << EXT4_BLOCK_SIZE_BITS(sb),
1366 res_dir);
1367 if (retval == 1)
1368 goto success;
1369 brelse(bh);
1370 if (retval == -1) {
1371 bh = ERR_PTR(ERR_BAD_DX_DIR);
1372 goto errout;
1373 }
1374
1375 /* Check to see if we should continue to search */
1376 retval = ext4_htree_next_block(dir, hinfo.hash, frame,
1377 frames, NULL);
1378 if (retval < 0) {
1379 ext4_warning(sb,
1380 "error %d reading index page in directory #%lu",
1381 retval, dir->i_ino);
1382 bh = ERR_PTR(retval);
1383 goto errout;
1384 }
1385 } while (retval == 1);
1386
1387 bh = NULL;
1388 errout:
1389 dxtrace(printk(KERN_DEBUG "%s not found\n", d_name->name));
1390 success:
1391 dx_release(frames);
1392 return bh;
1393 }
1394
1395 static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
1396 {
1397 struct inode *inode;
1398 struct ext4_dir_entry_2 *de;
1399 struct buffer_head *bh;
1400
1401 if (dentry->d_name.len > EXT4_NAME_LEN)
1402 return ERR_PTR(-ENAMETOOLONG);
1403
1404 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
1405 if (IS_ERR(bh))
1406 return (struct dentry *) bh;
1407 inode = NULL;
1408 if (bh) {
1409 __u32 ino = le32_to_cpu(de->inode);
1410 brelse(bh);
1411 if (!ext4_valid_inum(dir->i_sb, ino)) {
1412 EXT4_ERROR_INODE(dir, "bad inode number: %u", ino);
1413 return ERR_PTR(-EIO);
1414 }
1415 if (unlikely(ino == dir->i_ino)) {
1416 EXT4_ERROR_INODE(dir, "'%pd' linked to parent dir",
1417 dentry);
1418 return ERR_PTR(-EIO);
1419 }
1420 inode = ext4_iget(dir->i_sb, ino);
1421 if (inode == ERR_PTR(-ESTALE)) {
1422 EXT4_ERROR_INODE(dir,
1423 "deleted inode referenced: %u",
1424 ino);
1425 return ERR_PTR(-EIO);
1426 }
1427 }
1428 return d_splice_alias(inode, dentry);
1429 }
1430
1431
1432 struct dentry *ext4_get_parent(struct dentry *child)
1433 {
1434 __u32 ino;
1435 static const struct qstr dotdot = QSTR_INIT("..", 2);
1436 struct ext4_dir_entry_2 * de;
1437 struct buffer_head *bh;
1438
1439 bh = ext4_find_entry(child->d_inode, &dotdot, &de, NULL);
1440 if (IS_ERR(bh))
1441 return (struct dentry *) bh;
1442 if (!bh)
1443 return ERR_PTR(-ENOENT);
1444 ino = le32_to_cpu(de->inode);
1445 brelse(bh);
1446
1447 if (!ext4_valid_inum(child->d_inode->i_sb, ino)) {
1448 EXT4_ERROR_INODE(child->d_inode,
1449 "bad parent inode number: %u", ino);
1450 return ERR_PTR(-EIO);
1451 }
1452
1453 return d_obtain_alias(ext4_iget(child->d_inode->i_sb, ino));
1454 }
1455
1456 /*
1457 * Move count entries from end of map between two memory locations.
1458 * Returns pointer to last entry moved.
1459 */
1460 static struct ext4_dir_entry_2 *
1461 dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count,
1462 unsigned blocksize)
1463 {
1464 unsigned rec_len = 0;
1465
1466 while (count--) {
1467 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
1468 (from + (map->offs<<2));
1469 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1470 memcpy (to, de, rec_len);
1471 ((struct ext4_dir_entry_2 *) to)->rec_len =
1472 ext4_rec_len_to_disk(rec_len, blocksize);
1473 de->inode = 0;
1474 map++;
1475 to += rec_len;
1476 }
1477 return (struct ext4_dir_entry_2 *) (to - rec_len);
1478 }
1479
1480 /*
1481 * Compact each dir entry in the range to the minimal rec_len.
1482 * Returns pointer to last entry in range.
1483 */
1484 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize)
1485 {
1486 struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
1487 unsigned rec_len = 0;
1488
1489 prev = to = de;
1490 while ((char*)de < base + blocksize) {
1491 next = ext4_next_entry(de, blocksize);
1492 if (de->inode && de->name_len) {
1493 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1494 if (de > to)
1495 memmove(to, de, rec_len);
1496 to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
1497 prev = to;
1498 to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
1499 }
1500 de = next;
1501 }
1502 return prev;
1503 }
1504
1505 /*
1506 * Split a full leaf block to make room for a new dir entry.
1507 * Allocate a new block, and move entries so that they are approx. equally full.
1508 * Returns pointer to de in block into which the new entry will be inserted.
1509 */
1510 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
1511 struct buffer_head **bh,struct dx_frame *frame,
1512 struct dx_hash_info *hinfo)
1513 {
1514 unsigned blocksize = dir->i_sb->s_blocksize;
1515 unsigned count, continued;
1516 struct buffer_head *bh2;
1517 ext4_lblk_t newblock;
1518 u32 hash2;
1519 struct dx_map_entry *map;
1520 char *data1 = (*bh)->b_data, *data2;
1521 unsigned split, move, size;
1522 struct ext4_dir_entry_2 *de = NULL, *de2;
1523 struct ext4_dir_entry_tail *t;
1524 int csum_size = 0;
1525 int err = 0, i;
1526
1527 if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
1528 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
1529 csum_size = sizeof(struct ext4_dir_entry_tail);
1530
1531 bh2 = ext4_append(handle, dir, &newblock);
1532 if (IS_ERR(bh2)) {
1533 brelse(*bh);
1534 *bh = NULL;
1535 return (struct ext4_dir_entry_2 *) bh2;
1536 }
1537
1538 BUFFER_TRACE(*bh, "get_write_access");
1539 err = ext4_journal_get_write_access(handle, *bh);
1540 if (err)
1541 goto journal_error;
1542
1543 BUFFER_TRACE(frame->bh, "get_write_access");
1544 err = ext4_journal_get_write_access(handle, frame->bh);
1545 if (err)
1546 goto journal_error;
1547
1548 data2 = bh2->b_data;
1549
1550 /* create map in the end of data2 block */
1551 map = (struct dx_map_entry *) (data2 + blocksize);
1552 count = dx_make_map((struct ext4_dir_entry_2 *) data1,
1553 blocksize, hinfo, map);
1554 map -= count;
1555 dx_sort_map(map, count);
1556 /* Split the existing block in the middle, size-wise */
1557 size = 0;
1558 move = 0;
1559 for (i = count-1; i >= 0; i--) {
1560 /* is more than half of this entry in 2nd half of the block? */
1561 if (size + map[i].size/2 > blocksize/2)
1562 break;
1563 size += map[i].size;
1564 move++;
1565 }
1566 /* map index at which we will split */
1567 split = count - move;
1568 hash2 = map[split].hash;
1569 continued = hash2 == map[split - 1].hash;
1570 dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
1571 (unsigned long)dx_get_block(frame->at),
1572 hash2, split, count-split));
1573
1574 /* Fancy dance to stay within two buffers */
1575 de2 = dx_move_dirents(data1, data2, map + split, count - split, blocksize);
1576 de = dx_pack_dirents(data1, blocksize);
1577 de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
1578 (char *) de,
1579 blocksize);
1580 de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
1581 (char *) de2,
1582 blocksize);
1583 if (csum_size) {
1584 t = EXT4_DIRENT_TAIL(data2, blocksize);
1585 initialize_dirent_tail(t, blocksize);
1586
1587 t = EXT4_DIRENT_TAIL(data1, blocksize);
1588 initialize_dirent_tail(t, blocksize);
1589 }
1590
1591 dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data1, blocksize, 1));
1592 dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data2, blocksize, 1));
1593
1594 /* Which block gets the new entry? */
1595 if (hinfo->hash >= hash2) {
1596 swap(*bh, bh2);
1597 de = de2;
1598 }
1599 dx_insert_block(frame, hash2 + continued, newblock);
1600 err = ext4_handle_dirty_dirent_node(handle, dir, bh2);
1601 if (err)
1602 goto journal_error;
1603 err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
1604 if (err)
1605 goto journal_error;
1606 brelse(bh2);
1607 dxtrace(dx_show_index("frame", frame->entries));
1608 return de;
1609
1610 journal_error:
1611 brelse(*bh);
1612 brelse(bh2);
1613 *bh = NULL;
1614 ext4_std_error(dir->i_sb, err);
1615 return ERR_PTR(err);
1616 }
1617
1618 int ext4_find_dest_de(struct inode *dir, struct inode *inode,
1619 struct buffer_head *bh,
1620 void *buf, int buf_size,
1621 const char *name, int namelen,
1622 struct ext4_dir_entry_2 **dest_de)
1623 {
1624 struct ext4_dir_entry_2 *de;
1625 unsigned short reclen = EXT4_DIR_REC_LEN(namelen);
1626 int nlen, rlen;
1627 unsigned int offset = 0;
1628 char *top;
1629
1630 de = (struct ext4_dir_entry_2 *)buf;
1631 top = buf + buf_size - reclen;
1632 while ((char *) de <= top) {
1633 if (ext4_check_dir_entry(dir, NULL, de, bh,
1634 buf, buf_size, offset))
1635 return -EIO;
1636 if (ext4_match(namelen, name, de))
1637 return -EEXIST;
1638 nlen = EXT4_DIR_REC_LEN(de->name_len);
1639 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
1640 if ((de->inode ? rlen - nlen : rlen) >= reclen)
1641 break;
1642 de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
1643 offset += rlen;
1644 }
1645 if ((char *) de > top)
1646 return -ENOSPC;
1647
1648 *dest_de = de;
1649 return 0;
1650 }
1651
1652 void ext4_insert_dentry(struct inode *inode,
1653 struct ext4_dir_entry_2 *de,
1654 int buf_size,
1655 const char *name, int namelen)
1656 {
1657
1658 int nlen, rlen;
1659
1660 nlen = EXT4_DIR_REC_LEN(de->name_len);
1661 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
1662 if (de->inode) {
1663 struct ext4_dir_entry_2 *de1 =
1664 (struct ext4_dir_entry_2 *)((char *)de + nlen);
1665 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, buf_size);
1666 de->rec_len = ext4_rec_len_to_disk(nlen, buf_size);
1667 de = de1;
1668 }
1669 de->file_type = EXT4_FT_UNKNOWN;
1670 de->inode = cpu_to_le32(inode->i_ino);
1671 ext4_set_de_type(inode->i_sb, de, inode->i_mode);
1672 de->name_len = namelen;
1673 memcpy(de->name, name, namelen);
1674 }
1675 /*
1676 * Add a new entry into a directory (leaf) block. If de is non-NULL,
1677 * it points to a directory entry which is guaranteed to be large
1678 * enough for new directory entry. If de is NULL, then
1679 * add_dirent_to_buf will attempt search the directory block for
1680 * space. It will return -ENOSPC if no space is available, and -EIO
1681 * and -EEXIST if directory entry already exists.
1682 */
1683 static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
1684 struct inode *inode, struct ext4_dir_entry_2 *de,
1685 struct buffer_head *bh)
1686 {
1687 struct inode *dir = dentry->d_parent->d_inode;
1688 const char *name = dentry->d_name.name;
1689 int namelen = dentry->d_name.len;
1690 unsigned int blocksize = dir->i_sb->s_blocksize;
1691 int csum_size = 0;
1692 int err;
1693
1694 if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
1695 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
1696 csum_size = sizeof(struct ext4_dir_entry_tail);
1697
1698 if (!de) {
1699 err = ext4_find_dest_de(dir, inode,
1700 bh, bh->b_data, blocksize - csum_size,
1701 name, namelen, &de);
1702 if (err)
1703 return err;
1704 }
1705 BUFFER_TRACE(bh, "get_write_access");
1706 err = ext4_journal_get_write_access(handle, bh);
1707 if (err) {
1708 ext4_std_error(dir->i_sb, err);
1709 return err;
1710 }
1711
1712 /* By now the buffer is marked for journaling */
1713 ext4_insert_dentry(inode, de, blocksize, name, namelen);
1714
1715 /*
1716 * XXX shouldn't update any times until successful
1717 * completion of syscall, but too many callers depend
1718 * on this.
1719 *
1720 * XXX similarly, too many callers depend on
1721 * ext4_new_inode() setting the times, but error
1722 * recovery deletes the inode, so the worst that can
1723 * happen is that the times are slightly out of date
1724 * and/or different from the directory change time.
1725 */
1726 dir->i_mtime = dir->i_ctime = ext4_current_time(dir);
1727 ext4_update_dx_flag(dir);
1728 dir->i_version++;
1729 ext4_mark_inode_dirty(handle, dir);
1730 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1731 err = ext4_handle_dirty_dirent_node(handle, dir, bh);
1732 if (err)
1733 ext4_std_error(dir->i_sb, err);
1734 return 0;
1735 }
1736
1737 /*
1738 * This converts a one block unindexed directory to a 3 block indexed
1739 * directory, and adds the dentry to the indexed directory.
1740 */
1741 static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
1742 struct inode *inode, struct buffer_head *bh)
1743 {
1744 struct inode *dir = dentry->d_parent->d_inode;
1745 const char *name = dentry->d_name.name;
1746 int namelen = dentry->d_name.len;
1747 struct buffer_head *bh2;
1748 struct dx_root *root;
1749 struct dx_frame frames[2], *frame;
1750 struct dx_entry *entries;
1751 struct ext4_dir_entry_2 *de, *de2;
1752 struct ext4_dir_entry_tail *t;
1753 char *data1, *top;
1754 unsigned len;
1755 int retval;
1756 unsigned blocksize;
1757 struct dx_hash_info hinfo;
1758 ext4_lblk_t block;
1759 struct fake_dirent *fde;
1760 int csum_size = 0;
1761
1762 if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
1763 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
1764 csum_size = sizeof(struct ext4_dir_entry_tail);
1765
1766 blocksize = dir->i_sb->s_blocksize;
1767 dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
1768 BUFFER_TRACE(bh, "get_write_access");
1769 retval = ext4_journal_get_write_access(handle, bh);
1770 if (retval) {
1771 ext4_std_error(dir->i_sb, retval);
1772 brelse(bh);
1773 return retval;
1774 }
1775 root = (struct dx_root *) bh->b_data;
1776
1777 /* The 0th block becomes the root, move the dirents out */
1778 fde = &root->dotdot;
1779 de = (struct ext4_dir_entry_2 *)((char *)fde +
1780 ext4_rec_len_from_disk(fde->rec_len, blocksize));
1781 if ((char *) de >= (((char *) root) + blocksize)) {
1782 EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
1783 brelse(bh);
1784 return -EIO;
1785 }
1786 len = ((char *) root) + (blocksize - csum_size) - (char *) de;
1787
1788 /* Allocate new block for the 0th block's dirents */
1789 bh2 = ext4_append(handle, dir, &block);
1790 if (IS_ERR(bh2)) {
1791 brelse(bh);
1792 return PTR_ERR(bh2);
1793 }
1794 ext4_set_inode_flag(dir, EXT4_INODE_INDEX);
1795 data1 = bh2->b_data;
1796
1797 memcpy (data1, de, len);
1798 de = (struct ext4_dir_entry_2 *) data1;
1799 top = data1 + len;
1800 while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
1801 de = de2;
1802 de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
1803 (char *) de,
1804 blocksize);
1805
1806 if (csum_size) {
1807 t = EXT4_DIRENT_TAIL(data1, blocksize);
1808 initialize_dirent_tail(t, blocksize);
1809 }
1810
1811 /* Initialize the root; the dot dirents already exist */
1812 de = (struct ext4_dir_entry_2 *) (&root->dotdot);
1813 de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
1814 blocksize);
1815 memset (&root->info, 0, sizeof(root->info));
1816 root->info.info_length = sizeof(root->info);
1817 root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
1818 entries = root->entries;
1819 dx_set_block(entries, 1);
1820 dx_set_count(entries, 1);
1821 dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
1822
1823 /* Initialize as for dx_probe */
1824 hinfo.hash_version = root->info.hash_version;
1825 if (hinfo.hash_version <= DX_HASH_TEA)
1826 hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
1827 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
1828 ext4fs_dirhash(name, namelen, &hinfo);
1829 frame = frames;
1830 frame->entries = entries;
1831 frame->at = entries;
1832 frame->bh = bh;
1833 bh = bh2;
1834
1835 ext4_handle_dirty_dx_node(handle, dir, frame->bh);
1836 ext4_handle_dirty_dirent_node(handle, dir, bh);
1837
1838 de = do_split(handle,dir, &bh, frame, &hinfo);
1839 if (IS_ERR(de)) {
1840 /*
1841 * Even if the block split failed, we have to properly write
1842 * out all the changes we did so far. Otherwise we can end up
1843 * with corrupted filesystem.
1844 */
1845 ext4_mark_inode_dirty(handle, dir);
1846 dx_release(frames);
1847 return PTR_ERR(de);
1848 }
1849 dx_release(frames);
1850
1851 retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
1852 brelse(bh);
1853 return retval;
1854 }
1855
1856 /*
1857 * ext4_add_entry()
1858 *
1859 * adds a file entry to the specified directory, using the same
1860 * semantics as ext4_find_entry(). It returns NULL if it failed.
1861 *
1862 * NOTE!! The inode part of 'de' is left at 0 - which means you
1863 * may not sleep between calling this and putting something into
1864 * the entry, as someone else might have used it while you slept.
1865 */
1866 static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
1867 struct inode *inode)
1868 {
1869 struct inode *dir = dentry->d_parent->d_inode;
1870 struct buffer_head *bh;
1871 struct ext4_dir_entry_2 *de;
1872 struct ext4_dir_entry_tail *t;
1873 struct super_block *sb;
1874 int retval;
1875 int dx_fallback=0;
1876 unsigned blocksize;
1877 ext4_lblk_t block, blocks;
1878 int csum_size = 0;
1879
1880 if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
1881 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
1882 csum_size = sizeof(struct ext4_dir_entry_tail);
1883
1884 sb = dir->i_sb;
1885 blocksize = sb->s_blocksize;
1886 if (!dentry->d_name.len)
1887 return -EINVAL;
1888
1889 if (ext4_has_inline_data(dir)) {
1890 retval = ext4_try_add_inline_entry(handle, dentry, inode);
1891 if (retval < 0)
1892 return retval;
1893 if (retval == 1) {
1894 retval = 0;
1895 return retval;
1896 }
1897 }
1898
1899 if (is_dx(dir)) {
1900 retval = ext4_dx_add_entry(handle, dentry, inode);
1901 if (!retval || (retval != ERR_BAD_DX_DIR))
1902 return retval;
1903 ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
1904 dx_fallback++;
1905 ext4_mark_inode_dirty(handle, dir);
1906 }
1907 blocks = dir->i_size >> sb->s_blocksize_bits;
1908 for (block = 0; block < blocks; block++) {
1909 bh = ext4_read_dirblock(dir, block, DIRENT);
1910 if (IS_ERR(bh))
1911 return PTR_ERR(bh);
1912
1913 retval = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
1914 if (retval != -ENOSPC) {
1915 brelse(bh);
1916 return retval;
1917 }
1918
1919 if (blocks == 1 && !dx_fallback &&
1920 EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX))
1921 return make_indexed_dir(handle, dentry, inode, bh);
1922 brelse(bh);
1923 }
1924 bh = ext4_append(handle, dir, &block);
1925 if (IS_ERR(bh))
1926 return PTR_ERR(bh);
1927 de = (struct ext4_dir_entry_2 *) bh->b_data;
1928 de->inode = 0;
1929 de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize);
1930
1931 if (csum_size) {
1932 t = EXT4_DIRENT_TAIL(bh->b_data, blocksize);
1933 initialize_dirent_tail(t, blocksize);
1934 }
1935
1936 retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
1937 brelse(bh);
1938 if (retval == 0)
1939 ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY);
1940 return retval;
1941 }
1942
1943 /*
1944 * Returns 0 for success, or a negative error value
1945 */
1946 static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
1947 struct inode *inode)
1948 {
1949 struct dx_frame frames[2], *frame;
1950 struct dx_entry *entries, *at;
1951 struct dx_hash_info hinfo;
1952 struct buffer_head *bh;
1953 struct inode *dir = dentry->d_parent->d_inode;
1954 struct super_block *sb = dir->i_sb;
1955 struct ext4_dir_entry_2 *de;
1956 int err;
1957
1958 frame = dx_probe(&dentry->d_name, dir, &hinfo, frames);
1959 if (IS_ERR(frame))
1960 return PTR_ERR(frame);
1961 entries = frame->entries;
1962 at = frame->at;
1963 bh = ext4_read_dirblock(dir, dx_get_block(frame->at), DIRENT);
1964 if (IS_ERR(bh)) {
1965 err = PTR_ERR(bh);
1966 bh = NULL;
1967 goto cleanup;
1968 }
1969
1970 BUFFER_TRACE(bh, "get_write_access");
1971 err = ext4_journal_get_write_access(handle, bh);
1972 if (err)
1973 goto journal_error;
1974
1975 err = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
1976 if (err != -ENOSPC)
1977 goto cleanup;
1978
1979 /* Block full, should compress but for now just split */
1980 dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
1981 dx_get_count(entries), dx_get_limit(entries)));
1982 /* Need to split index? */
1983 if (dx_get_count(entries) == dx_get_limit(entries)) {
1984 ext4_lblk_t newblock;
1985 unsigned icount = dx_get_count(entries);
1986 int levels = frame - frames;
1987 struct dx_entry *entries2;
1988 struct dx_node *node2;
1989 struct buffer_head *bh2;
1990
1991 if (levels && (dx_get_count(frames->entries) ==
1992 dx_get_limit(frames->entries))) {
1993 ext4_warning(sb, "Directory index full!");
1994 err = -ENOSPC;
1995 goto cleanup;
1996 }
1997 bh2 = ext4_append(handle, dir, &newblock);
1998 if (IS_ERR(bh2)) {
1999 err = PTR_ERR(bh2);
2000 goto cleanup;
2001 }
2002 node2 = (struct dx_node *)(bh2->b_data);
2003 entries2 = node2->entries;
2004 memset(&node2->fake, 0, sizeof(struct fake_dirent));
2005 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
2006 sb->s_blocksize);
2007 BUFFER_TRACE(frame->bh, "get_write_access");
2008 err = ext4_journal_get_write_access(handle, frame->bh);
2009 if (err)
2010 goto journal_error;
2011 if (levels) {
2012 unsigned icount1 = icount/2, icount2 = icount - icount1;
2013 unsigned hash2 = dx_get_hash(entries + icount1);
2014 dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
2015 icount1, icount2));
2016
2017 BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
2018 err = ext4_journal_get_write_access(handle,
2019 frames[0].bh);
2020 if (err)
2021 goto journal_error;
2022
2023 memcpy((char *) entries2, (char *) (entries + icount1),
2024 icount2 * sizeof(struct dx_entry));
2025 dx_set_count(entries, icount1);
2026 dx_set_count(entries2, icount2);
2027 dx_set_limit(entries2, dx_node_limit(dir));
2028
2029 /* Which index block gets the new entry? */
2030 if (at - entries >= icount1) {
2031 frame->at = at = at - entries - icount1 + entries2;
2032 frame->entries = entries = entries2;
2033 swap(frame->bh, bh2);
2034 }
2035 dx_insert_block(frames + 0, hash2, newblock);
2036 dxtrace(dx_show_index("node", frames[1].entries));
2037 dxtrace(dx_show_index("node",
2038 ((struct dx_node *) bh2->b_data)->entries));
2039 err = ext4_handle_dirty_dx_node(handle, dir, bh2);
2040 if (err)
2041 goto journal_error;
2042 brelse (bh2);
2043 } else {
2044 dxtrace(printk(KERN_DEBUG
2045 "Creating second level index...\n"));
2046 memcpy((char *) entries2, (char *) entries,
2047 icount * sizeof(struct dx_entry));
2048 dx_set_limit(entries2, dx_node_limit(dir));
2049
2050 /* Set up root */
2051 dx_set_count(entries, 1);
2052 dx_set_block(entries + 0, newblock);
2053 ((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels = 1;
2054
2055 /* Add new access path frame */
2056 frame = frames + 1;
2057 frame->at = at = at - entries + entries2;
2058 frame->entries = entries = entries2;
2059 frame->bh = bh2;
2060 err = ext4_journal_get_write_access(handle,
2061 frame->bh);
2062 if (err)
2063 goto journal_error;
2064 }
2065 err = ext4_handle_dirty_dx_node(handle, dir, frames[0].bh);
2066 if (err) {
2067 ext4_std_error(inode->i_sb, err);
2068 goto cleanup;
2069 }
2070 }
2071 de = do_split(handle, dir, &bh, frame, &hinfo);
2072 if (IS_ERR(de)) {
2073 err = PTR_ERR(de);
2074 goto cleanup;
2075 }
2076 err = add_dirent_to_buf(handle, dentry, inode, de, bh);
2077 goto cleanup;
2078
2079 journal_error:
2080 ext4_std_error(dir->i_sb, err);
2081 cleanup:
2082 brelse(bh);
2083 dx_release(frames);
2084 return err;
2085 }
2086
2087 /*
2088 * ext4_generic_delete_entry deletes a directory entry by merging it
2089 * with the previous entry
2090 */
2091 int ext4_generic_delete_entry(handle_t *handle,
2092 struct inode *dir,
2093 struct ext4_dir_entry_2 *de_del,
2094 struct buffer_head *bh,
2095 void *entry_buf,
2096 int buf_size,
2097 int csum_size)
2098 {
2099 struct ext4_dir_entry_2 *de, *pde;
2100 unsigned int blocksize = dir->i_sb->s_blocksize;
2101 int i;
2102
2103 i = 0;
2104 pde = NULL;
2105 de = (struct ext4_dir_entry_2 *)entry_buf;
2106 while (i < buf_size - csum_size) {
2107 if (ext4_check_dir_entry(dir, NULL, de, bh,
2108 bh->b_data, bh->b_size, i))
2109 return -EIO;
2110 if (de == de_del) {
2111 if (pde)
2112 pde->rec_len = ext4_rec_len_to_disk(
2113 ext4_rec_len_from_disk(pde->rec_len,
2114 blocksize) +
2115 ext4_rec_len_from_disk(de->rec_len,
2116 blocksize),
2117 blocksize);
2118 else
2119 de->inode = 0;
2120 dir->i_version++;
2121 return 0;
2122 }
2123 i += ext4_rec_len_from_disk(de->rec_len, blocksize);
2124 pde = de;
2125 de = ext4_next_entry(de, blocksize);
2126 }
2127 return -ENOENT;
2128 }
2129
2130 static int ext4_delete_entry(handle_t *handle,
2131 struct inode *dir,
2132 struct ext4_dir_entry_2 *de_del,
2133 struct buffer_head *bh)
2134 {
2135 int err, csum_size = 0;
2136
2137 if (ext4_has_inline_data(dir)) {
2138 int has_inline_data = 1;
2139 err = ext4_delete_inline_entry(handle, dir, de_del, bh,
2140 &has_inline_data);
2141 if (has_inline_data)
2142 return err;
2143 }
2144
2145 if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
2146 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
2147 csum_size = sizeof(struct ext4_dir_entry_tail);
2148
2149 BUFFER_TRACE(bh, "get_write_access");
2150 err = ext4_journal_get_write_access(handle, bh);
2151 if (unlikely(err))
2152 goto out;
2153
2154 err = ext4_generic_delete_entry(handle, dir, de_del,
2155 bh, bh->b_data,
2156 dir->i_sb->s_blocksize, csum_size);
2157 if (err)
2158 goto out;
2159
2160 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
2161 err = ext4_handle_dirty_dirent_node(handle, dir, bh);
2162 if (unlikely(err))
2163 goto out;
2164
2165 return 0;
2166 out:
2167 if (err != -ENOENT)
2168 ext4_std_error(dir->i_sb, err);
2169 return err;
2170 }
2171
2172 /*
2173 * DIR_NLINK feature is set if 1) nlinks > EXT4_LINK_MAX or 2) nlinks == 2,
2174 * since this indicates that nlinks count was previously 1.
2175 */
2176 static void ext4_inc_count(handle_t *handle, struct inode *inode)
2177 {
2178 inc_nlink(inode);
2179 if (is_dx(inode) && inode->i_nlink > 1) {
2180 /* limit is 16-bit i_links_count */
2181 if (inode->i_nlink >= EXT4_LINK_MAX || inode->i_nlink == 2) {
2182 set_nlink(inode, 1);
2183 EXT4_SET_RO_COMPAT_FEATURE(inode->i_sb,
2184 EXT4_FEATURE_RO_COMPAT_DIR_NLINK);
2185 }
2186 }
2187 }
2188
2189 /*
2190 * If a directory had nlink == 1, then we should let it be 1. This indicates
2191 * directory has >EXT4_LINK_MAX subdirs.
2192 */
2193 static void ext4_dec_count(handle_t *handle, struct inode *inode)
2194 {
2195 if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
2196 drop_nlink(inode);
2197 }
2198
2199
2200 static int ext4_add_nondir(handle_t *handle,
2201 struct dentry *dentry, struct inode *inode)
2202 {
2203 int err = ext4_add_entry(handle, dentry, inode);
2204 if (!err) {
2205 ext4_mark_inode_dirty(handle, inode);
2206 unlock_new_inode(inode);
2207 d_instantiate(dentry, inode);
2208 return 0;
2209 }
2210 drop_nlink(inode);
2211 unlock_new_inode(inode);
2212 iput(inode);
2213 return err;
2214 }
2215
2216 /*
2217 * By the time this is called, we already have created
2218 * the directory cache entry for the new file, but it
2219 * is so far negative - it has no inode.
2220 *
2221 * If the create succeeds, we fill in the inode information
2222 * with d_instantiate().
2223 */
2224 static int ext4_create(struct inode *dir, struct dentry *dentry, umode_t mode,
2225 bool excl)
2226 {
2227 handle_t *handle;
2228 struct inode *inode;
2229 int err, credits, retries = 0;
2230
2231 dquot_initialize(dir);
2232
2233 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2234 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2235 retry:
2236 inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
2237 NULL, EXT4_HT_DIR, credits);
2238 handle = ext4_journal_current_handle();
2239 err = PTR_ERR(inode);
2240 if (!IS_ERR(inode)) {
2241 inode->i_op = &ext4_file_inode_operations;
2242 inode->i_fop = &ext4_file_operations;
2243 ext4_set_aops(inode);
2244 err = ext4_add_nondir(handle, dentry, inode);
2245 if (!err && IS_DIRSYNC(dir))
2246 ext4_handle_sync(handle);
2247 }
2248 if (handle)
2249 ext4_journal_stop(handle);
2250 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2251 goto retry;
2252 return err;
2253 }
2254
2255 static int ext4_mknod(struct inode *dir, struct dentry *dentry,
2256 umode_t mode, dev_t rdev)
2257 {
2258 handle_t *handle;
2259 struct inode *inode;
2260 int err, credits, retries = 0;
2261
2262 if (!new_valid_dev(rdev))
2263 return -EINVAL;
2264
2265 dquot_initialize(dir);
2266
2267 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2268 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2269 retry:
2270 inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
2271 NULL, EXT4_HT_DIR, credits);
2272 handle = ext4_journal_current_handle();
2273 err = PTR_ERR(inode);
2274 if (!IS_ERR(inode)) {
2275 init_special_inode(inode, inode->i_mode, rdev);
2276 inode->i_op = &ext4_special_inode_operations;
2277 err = ext4_add_nondir(handle, dentry, inode);
2278 if (!err && IS_DIRSYNC(dir))
2279 ext4_handle_sync(handle);
2280 }
2281 if (handle)
2282 ext4_journal_stop(handle);
2283 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2284 goto retry;
2285 return err;
2286 }
2287
2288 static int ext4_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
2289 {
2290 handle_t *handle;
2291 struct inode *inode;
2292 int err, retries = 0;
2293
2294 dquot_initialize(dir);
2295
2296 retry:
2297 inode = ext4_new_inode_start_handle(dir, mode,
2298 NULL, 0, NULL,
2299 EXT4_HT_DIR,
2300 EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
2301 4 + EXT4_XATTR_TRANS_BLOCKS);
2302 handle = ext4_journal_current_handle();
2303 err = PTR_ERR(inode);
2304 if (!IS_ERR(inode)) {
2305 inode->i_op = &ext4_file_inode_operations;
2306 inode->i_fop = &ext4_file_operations;
2307 ext4_set_aops(inode);
2308 d_tmpfile(dentry, inode);
2309 err = ext4_orphan_add(handle, inode);
2310 if (err)
2311 goto err_unlock_inode;
2312 mark_inode_dirty(inode);
2313 unlock_new_inode(inode);
2314 }
2315 if (handle)
2316 ext4_journal_stop(handle);
2317 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2318 goto retry;
2319 return err;
2320 err_unlock_inode:
2321 ext4_journal_stop(handle);
2322 unlock_new_inode(inode);
2323 return err;
2324 }
2325
2326 struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
2327 struct ext4_dir_entry_2 *de,
2328 int blocksize, int csum_size,
2329 unsigned int parent_ino, int dotdot_real_len)
2330 {
2331 de->inode = cpu_to_le32(inode->i_ino);
2332 de->name_len = 1;
2333 de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
2334 blocksize);
2335 strcpy(de->name, ".");
2336 ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2337
2338 de = ext4_next_entry(de, blocksize);
2339 de->inode = cpu_to_le32(parent_ino);
2340 de->name_len = 2;
2341 if (!dotdot_real_len)
2342 de->rec_len = ext4_rec_len_to_disk(blocksize -
2343 (csum_size + EXT4_DIR_REC_LEN(1)),
2344 blocksize);
2345 else
2346 de->rec_len = ext4_rec_len_to_disk(
2347 EXT4_DIR_REC_LEN(de->name_len), blocksize);
2348 strcpy(de->name, "..");
2349 ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2350
2351 return ext4_next_entry(de, blocksize);
2352 }
2353
2354 static int ext4_init_new_dir(handle_t *handle, struct inode *dir,
2355 struct inode *inode)
2356 {
2357 struct buffer_head *dir_block = NULL;
2358 struct ext4_dir_entry_2 *de;
2359 struct ext4_dir_entry_tail *t;
2360 ext4_lblk_t block = 0;
2361 unsigned int blocksize = dir->i_sb->s_blocksize;
2362 int csum_size = 0;
2363 int err;
2364
2365 if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
2366 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
2367 csum_size = sizeof(struct ext4_dir_entry_tail);
2368
2369 if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
2370 err = ext4_try_create_inline_dir(handle, dir, inode);
2371 if (err < 0 && err != -ENOSPC)
2372 goto out;
2373 if (!err)
2374 goto out;
2375 }
2376
2377 inode->i_size = 0;
2378 dir_block = ext4_append(handle, inode, &block);
2379 if (IS_ERR(dir_block))
2380 return PTR_ERR(dir_block);
2381 de = (struct ext4_dir_entry_2 *)dir_block->b_data;
2382 ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0);
2383 set_nlink(inode, 2);
2384 if (csum_size) {
2385 t = EXT4_DIRENT_TAIL(dir_block->b_data, blocksize);
2386 initialize_dirent_tail(t, blocksize);
2387 }
2388
2389 BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
2390 err = ext4_handle_dirty_dirent_node(handle, inode, dir_block);
2391 if (err)
2392 goto out;
2393 set_buffer_verified(dir_block);
2394 out:
2395 brelse(dir_block);
2396 return err;
2397 }
2398
2399 static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
2400 {
2401 handle_t *handle;
2402 struct inode *inode;
2403 int err, credits, retries = 0;
2404
2405 if (EXT4_DIR_LINK_MAX(dir))
2406 return -EMLINK;
2407
2408 dquot_initialize(dir);
2409
2410 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2411 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2412 retry:
2413 inode = ext4_new_inode_start_handle(dir, S_IFDIR | mode,
2414 &dentry->d_name,
2415 0, NULL, EXT4_HT_DIR, credits);
2416 handle = ext4_journal_current_handle();
2417 err = PTR_ERR(inode);
2418 if (IS_ERR(inode))
2419 goto out_stop;
2420
2421 inode->i_op = &ext4_dir_inode_operations;
2422 inode->i_fop = &ext4_dir_operations;
2423 err = ext4_init_new_dir(handle, dir, inode);
2424 if (err)
2425 goto out_clear_inode;
2426 err = ext4_mark_inode_dirty(handle, inode);
2427 if (!err)
2428 err = ext4_add_entry(handle, dentry, inode);
2429 if (err) {
2430 out_clear_inode:
2431 clear_nlink(inode);
2432 unlock_new_inode(inode);
2433 ext4_mark_inode_dirty(handle, inode);
2434 iput(inode);
2435 goto out_stop;
2436 }
2437 ext4_inc_count(handle, dir);
2438 ext4_update_dx_flag(dir);
2439 err = ext4_mark_inode_dirty(handle, dir);
2440 if (err)
2441 goto out_clear_inode;
2442 unlock_new_inode(inode);
2443 d_instantiate(dentry, inode);
2444 if (IS_DIRSYNC(dir))
2445 ext4_handle_sync(handle);
2446
2447 out_stop:
2448 if (handle)
2449 ext4_journal_stop(handle);
2450 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2451 goto retry;
2452 return err;
2453 }
2454
2455 /*
2456 * routine to check that the specified directory is empty (for rmdir)
2457 */
2458 static int empty_dir(struct inode *inode)
2459 {
2460 unsigned int offset;
2461 struct buffer_head *bh;
2462 struct ext4_dir_entry_2 *de, *de1;
2463 struct super_block *sb;
2464 int err = 0;
2465
2466 if (ext4_has_inline_data(inode)) {
2467 int has_inline_data = 1;
2468
2469 err = empty_inline_dir(inode, &has_inline_data);
2470 if (has_inline_data)
2471 return err;
2472 }
2473
2474 sb = inode->i_sb;
2475 if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2)) {
2476 EXT4_ERROR_INODE(inode, "invalid size");
2477 return 1;
2478 }
2479 bh = ext4_read_dirblock(inode, 0, EITHER);
2480 if (IS_ERR(bh))
2481 return 1;
2482
2483 de = (struct ext4_dir_entry_2 *) bh->b_data;
2484 de1 = ext4_next_entry(de, sb->s_blocksize);
2485 if (le32_to_cpu(de->inode) != inode->i_ino ||
2486 !le32_to_cpu(de1->inode) ||
2487 strcmp(".", de->name) ||
2488 strcmp("..", de1->name)) {
2489 ext4_warning(inode->i_sb,
2490 "bad directory (dir #%lu) - no `.' or `..'",
2491 inode->i_ino);
2492 brelse(bh);
2493 return 1;
2494 }
2495 offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) +
2496 ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize);
2497 de = ext4_next_entry(de1, sb->s_blocksize);
2498 while (offset < inode->i_size) {
2499 if ((void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
2500 unsigned int lblock;
2501 err = 0;
2502 brelse(bh);
2503 lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb);
2504 bh = ext4_read_dirblock(inode, lblock, EITHER);
2505 if (IS_ERR(bh))
2506 return 1;
2507 de = (struct ext4_dir_entry_2 *) bh->b_data;
2508 }
2509 if (ext4_check_dir_entry(inode, NULL, de, bh,
2510 bh->b_data, bh->b_size, offset)) {
2511 de = (struct ext4_dir_entry_2 *)(bh->b_data +
2512 sb->s_blocksize);
2513 offset = (offset | (sb->s_blocksize - 1)) + 1;
2514 continue;
2515 }
2516 if (le32_to_cpu(de->inode)) {
2517 brelse(bh);
2518 return 0;
2519 }
2520 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
2521 de = ext4_next_entry(de, sb->s_blocksize);
2522 }
2523 brelse(bh);
2524 return 1;
2525 }
2526
2527 /*
2528 * ext4_orphan_add() links an unlinked or truncated inode into a list of
2529 * such inodes, starting at the superblock, in case we crash before the
2530 * file is closed/deleted, or in case the inode truncate spans multiple
2531 * transactions and the last transaction is not recovered after a crash.
2532 *
2533 * At filesystem recovery time, we walk this list deleting unlinked
2534 * inodes and truncating linked inodes in ext4_orphan_cleanup().
2535 *
2536 * Orphan list manipulation functions must be called under i_mutex unless
2537 * we are just creating the inode or deleting it.
2538 */
2539 int ext4_orphan_add(handle_t *handle, struct inode *inode)
2540 {
2541 struct super_block *sb = inode->i_sb;
2542 struct ext4_sb_info *sbi = EXT4_SB(sb);
2543 struct ext4_iloc iloc;
2544 int err = 0, rc;
2545 bool dirty = false;
2546
2547 if (!sbi->s_journal || is_bad_inode(inode))
2548 return 0;
2549
2550 WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
2551 !mutex_is_locked(&inode->i_mutex));
2552 /*
2553 * Exit early if inode already is on orphan list. This is a big speedup
2554 * since we don't have to contend on the global s_orphan_lock.
2555 */
2556 if (!list_empty(&EXT4_I(inode)->i_orphan))
2557 return 0;
2558
2559 /*
2560 * Orphan handling is only valid for files with data blocks
2561 * being truncated, or files being unlinked. Note that we either
2562 * hold i_mutex, or the inode can not be referenced from outside,
2563 * so i_nlink should not be bumped due to race
2564 */
2565 J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2566 S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
2567
2568 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2569 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2570 if (err)
2571 goto out;
2572
2573 err = ext4_reserve_inode_write(handle, inode, &iloc);
2574 if (err)
2575 goto out;
2576
2577 mutex_lock(&sbi->s_orphan_lock);
2578 /*
2579 * Due to previous errors inode may be already a part of on-disk
2580 * orphan list. If so skip on-disk list modification.
2581 */
2582 if (!NEXT_ORPHAN(inode) || NEXT_ORPHAN(inode) >
2583 (le32_to_cpu(sbi->s_es->s_inodes_count))) {
2584 /* Insert this inode at the head of the on-disk orphan list */
2585 NEXT_ORPHAN(inode) = le32_to_cpu(sbi->s_es->s_last_orphan);
2586 sbi->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
2587 dirty = true;
2588 }
2589 list_add(&EXT4_I(inode)->i_orphan, &sbi->s_orphan);
2590 mutex_unlock(&sbi->s_orphan_lock);
2591
2592 if (dirty) {
2593 err = ext4_handle_dirty_super(handle, sb);
2594 rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
2595 if (!err)
2596 err = rc;
2597 if (err) {
2598 /*
2599 * We have to remove inode from in-memory list if
2600 * addition to on disk orphan list failed. Stray orphan
2601 * list entries can cause panics at unmount time.
2602 */
2603 mutex_lock(&sbi->s_orphan_lock);
2604 list_del(&EXT4_I(inode)->i_orphan);
2605 mutex_unlock(&sbi->s_orphan_lock);
2606 }
2607 }
2608 jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
2609 jbd_debug(4, "orphan inode %lu will point to %d\n",
2610 inode->i_ino, NEXT_ORPHAN(inode));
2611 out:
2612 ext4_std_error(sb, err);
2613 return err;
2614 }
2615
2616 /*
2617 * ext4_orphan_del() removes an unlinked or truncated inode from the list
2618 * of such inodes stored on disk, because it is finally being cleaned up.
2619 */
2620 int ext4_orphan_del(handle_t *handle, struct inode *inode)
2621 {
2622 struct list_head *prev;
2623 struct ext4_inode_info *ei = EXT4_I(inode);
2624 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2625 __u32 ino_next;
2626 struct ext4_iloc iloc;
2627 int err = 0;
2628
2629 if (!sbi->s_journal && !(sbi->s_mount_state & EXT4_ORPHAN_FS))
2630 return 0;
2631
2632 WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
2633 !mutex_is_locked(&inode->i_mutex));
2634 /* Do this quick check before taking global s_orphan_lock. */
2635 if (list_empty(&ei->i_orphan))
2636 return 0;
2637
2638 if (handle) {
2639 /* Grab inode buffer early before taking global s_orphan_lock */
2640 err = ext4_reserve_inode_write(handle, inode, &iloc);
2641 }
2642
2643 mutex_lock(&sbi->s_orphan_lock);
2644 jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
2645
2646 prev = ei->i_orphan.prev;
2647 list_del_init(&ei->i_orphan);
2648
2649 /* If we're on an error path, we may not have a valid
2650 * transaction handle with which to update the orphan list on
2651 * disk, but we still need to remove the inode from the linked
2652 * list in memory. */
2653 if (!handle || err) {
2654 mutex_unlock(&sbi->s_orphan_lock);
2655 goto out_err;
2656 }
2657
2658 ino_next = NEXT_ORPHAN(inode);
2659 if (prev == &sbi->s_orphan) {
2660 jbd_debug(4, "superblock will point to %u\n", ino_next);
2661 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2662 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2663 if (err) {
2664 mutex_unlock(&sbi->s_orphan_lock);
2665 goto out_brelse;
2666 }
2667 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
2668 mutex_unlock(&sbi->s_orphan_lock);
2669 err = ext4_handle_dirty_super(handle, inode->i_sb);
2670 } else {
2671 struct ext4_iloc iloc2;
2672 struct inode *i_prev =
2673 &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
2674
2675 jbd_debug(4, "orphan inode %lu will point to %u\n",
2676 i_prev->i_ino, ino_next);
2677 err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
2678 if (err) {
2679 mutex_unlock(&sbi->s_orphan_lock);
2680 goto out_brelse;
2681 }
2682 NEXT_ORPHAN(i_prev) = ino_next;
2683 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
2684 mutex_unlock(&sbi->s_orphan_lock);
2685 }
2686 if (err)
2687 goto out_brelse;
2688 NEXT_ORPHAN(inode) = 0;
2689 err = ext4_mark_iloc_dirty(handle, inode, &iloc);
2690 out_err:
2691 ext4_std_error(inode->i_sb, err);
2692 return err;
2693
2694 out_brelse:
2695 brelse(iloc.bh);
2696 goto out_err;
2697 }
2698
2699 static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
2700 {
2701 int retval;
2702 struct inode *inode;
2703 struct buffer_head *bh;
2704 struct ext4_dir_entry_2 *de;
2705 handle_t *handle = NULL;
2706
2707 /* Initialize quotas before so that eventual writes go in
2708 * separate transaction */
2709 dquot_initialize(dir);
2710 dquot_initialize(dentry->d_inode);
2711
2712 retval = -ENOENT;
2713 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
2714 if (IS_ERR(bh))
2715 return PTR_ERR(bh);
2716 if (!bh)
2717 goto end_rmdir;
2718
2719 inode = dentry->d_inode;
2720
2721 retval = -EIO;
2722 if (le32_to_cpu(de->inode) != inode->i_ino)
2723 goto end_rmdir;
2724
2725 retval = -ENOTEMPTY;
2726 if (!empty_dir(inode))
2727 goto end_rmdir;
2728
2729 handle = ext4_journal_start(dir, EXT4_HT_DIR,
2730 EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
2731 if (IS_ERR(handle)) {
2732 retval = PTR_ERR(handle);
2733 handle = NULL;
2734 goto end_rmdir;
2735 }
2736
2737 if (IS_DIRSYNC(dir))
2738 ext4_handle_sync(handle);
2739
2740 retval = ext4_delete_entry(handle, dir, de, bh);
2741 if (retval)
2742 goto end_rmdir;
2743 if (!EXT4_DIR_LINK_EMPTY(inode))
2744 ext4_warning(inode->i_sb,
2745 "empty directory has too many links (%d)",
2746 inode->i_nlink);
2747 inode->i_version++;
2748 clear_nlink(inode);
2749 /* There's no need to set i_disksize: the fact that i_nlink is
2750 * zero will ensure that the right thing happens during any
2751 * recovery. */
2752 inode->i_size = 0;
2753 ext4_orphan_add(handle, inode);
2754 inode->i_ctime = dir->i_ctime = dir->i_mtime = ext4_current_time(inode);
2755 ext4_mark_inode_dirty(handle, inode);
2756 ext4_dec_count(handle, dir);
2757 ext4_update_dx_flag(dir);
2758 ext4_mark_inode_dirty(handle, dir);
2759
2760 end_rmdir:
2761 brelse(bh);
2762 if (handle)
2763 ext4_journal_stop(handle);
2764 return retval;
2765 }
2766
2767 static int ext4_unlink(struct inode *dir, struct dentry *dentry)
2768 {
2769 int retval;
2770 struct inode *inode;
2771 struct buffer_head *bh;
2772 struct ext4_dir_entry_2 *de;
2773 handle_t *handle = NULL;
2774
2775 trace_ext4_unlink_enter(dir, dentry);
2776 /* Initialize quotas before so that eventual writes go
2777 * in separate transaction */
2778 dquot_initialize(dir);
2779 dquot_initialize(dentry->d_inode);
2780
2781 retval = -ENOENT;
2782 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
2783 if (IS_ERR(bh))
2784 return PTR_ERR(bh);
2785 if (!bh)
2786 goto end_unlink;
2787
2788 inode = dentry->d_inode;
2789
2790 retval = -EIO;
2791 if (le32_to_cpu(de->inode) != inode->i_ino)
2792 goto end_unlink;
2793
2794 handle = ext4_journal_start(dir, EXT4_HT_DIR,
2795 EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
2796 if (IS_ERR(handle)) {
2797 retval = PTR_ERR(handle);
2798 handle = NULL;
2799 goto end_unlink;
2800 }
2801
2802 if (IS_DIRSYNC(dir))
2803 ext4_handle_sync(handle);
2804
2805 if (!inode->i_nlink) {
2806 ext4_warning(inode->i_sb,
2807 "Deleting nonexistent file (%lu), %d",
2808 inode->i_ino, inode->i_nlink);
2809 set_nlink(inode, 1);
2810 }
2811 retval = ext4_delete_entry(handle, dir, de, bh);
2812 if (retval)
2813 goto end_unlink;
2814 dir->i_ctime = dir->i_mtime = ext4_current_time(dir);
2815 ext4_update_dx_flag(dir);
2816 ext4_mark_inode_dirty(handle, dir);
2817 drop_nlink(inode);
2818 if (!inode->i_nlink)
2819 ext4_orphan_add(handle, inode);
2820 inode->i_ctime = ext4_current_time(inode);
2821 ext4_mark_inode_dirty(handle, inode);
2822 retval = 0;
2823
2824 end_unlink:
2825 brelse(bh);
2826 if (handle)
2827 ext4_journal_stop(handle);
2828 trace_ext4_unlink_exit(dentry, retval);
2829 return retval;
2830 }
2831
2832 static int ext4_symlink(struct inode *dir,
2833 struct dentry *dentry, const char *symname)
2834 {
2835 handle_t *handle;
2836 struct inode *inode;
2837 int l, err, retries = 0;
2838 int credits;
2839
2840 l = strlen(symname)+1;
2841 if (l > dir->i_sb->s_blocksize)
2842 return -ENAMETOOLONG;
2843
2844 dquot_initialize(dir);
2845
2846 if (l > EXT4_N_BLOCKS * 4) {
2847 /*
2848 * For non-fast symlinks, we just allocate inode and put it on
2849 * orphan list in the first transaction => we need bitmap,
2850 * group descriptor, sb, inode block, quota blocks, and
2851 * possibly selinux xattr blocks.
2852 */
2853 credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
2854 EXT4_XATTR_TRANS_BLOCKS;
2855 } else {
2856 /*
2857 * Fast symlink. We have to add entry to directory
2858 * (EXT4_DATA_TRANS_BLOCKS + EXT4_INDEX_EXTRA_TRANS_BLOCKS),
2859 * allocate new inode (bitmap, group descriptor, inode block,
2860 * quota blocks, sb is already counted in previous macros).
2861 */
2862 credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2863 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3;
2864 }
2865 retry:
2866 inode = ext4_new_inode_start_handle(dir, S_IFLNK|S_IRWXUGO,
2867 &dentry->d_name, 0, NULL,
2868 EXT4_HT_DIR, credits);
2869 handle = ext4_journal_current_handle();
2870 err = PTR_ERR(inode);
2871 if (IS_ERR(inode))
2872 goto out_stop;
2873
2874 if (l > EXT4_N_BLOCKS * 4) {
2875 inode->i_op = &ext4_symlink_inode_operations;
2876 ext4_set_aops(inode);
2877 /*
2878 * We cannot call page_symlink() with transaction started
2879 * because it calls into ext4_write_begin() which can wait
2880 * for transaction commit if we are running out of space
2881 * and thus we deadlock. So we have to stop transaction now
2882 * and restart it when symlink contents is written.
2883 *
2884 * To keep fs consistent in case of crash, we have to put inode
2885 * to orphan list in the mean time.
2886 */
2887 drop_nlink(inode);
2888 err = ext4_orphan_add(handle, inode);
2889 ext4_journal_stop(handle);
2890 if (err)
2891 goto err_drop_inode;
2892 err = __page_symlink(inode, symname, l, 1);
2893 if (err)
2894 goto err_drop_inode;
2895 /*
2896 * Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS
2897 * + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified
2898 */
2899 handle = ext4_journal_start(dir, EXT4_HT_DIR,
2900 EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2901 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1);
2902 if (IS_ERR(handle)) {
2903 err = PTR_ERR(handle);
2904 goto err_drop_inode;
2905 }
2906 set_nlink(inode, 1);
2907 err = ext4_orphan_del(handle, inode);
2908 if (err) {
2909 ext4_journal_stop(handle);
2910 clear_nlink(inode);
2911 goto err_drop_inode;
2912 }
2913 } else {
2914 /* clear the extent format for fast symlink */
2915 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
2916 inode->i_op = &ext4_fast_symlink_inode_operations;
2917 memcpy((char *)&EXT4_I(inode)->i_data, symname, l);
2918 inode->i_size = l-1;
2919 }
2920 EXT4_I(inode)->i_disksize = inode->i_size;
2921 err = ext4_add_nondir(handle, dentry, inode);
2922 if (!err && IS_DIRSYNC(dir))
2923 ext4_handle_sync(handle);
2924
2925 out_stop:
2926 if (handle)
2927 ext4_journal_stop(handle);
2928 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2929 goto retry;
2930 return err;
2931 err_drop_inode:
2932 unlock_new_inode(inode);
2933 iput(inode);
2934 return err;
2935 }
2936
2937 static int ext4_link(struct dentry *old_dentry,
2938 struct inode *dir, struct dentry *dentry)
2939 {
2940 handle_t *handle;
2941 struct inode *inode = old_dentry->d_inode;
2942 int err, retries = 0;
2943
2944 if (inode->i_nlink >= EXT4_LINK_MAX)
2945 return -EMLINK;
2946
2947 dquot_initialize(dir);
2948
2949 retry:
2950 handle = ext4_journal_start(dir, EXT4_HT_DIR,
2951 (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2952 EXT4_INDEX_EXTRA_TRANS_BLOCKS) + 1);
2953 if (IS_ERR(handle))
2954 return PTR_ERR(handle);
2955
2956 if (IS_DIRSYNC(dir))
2957 ext4_handle_sync(handle);
2958
2959 inode->i_ctime = ext4_current_time(inode);
2960 ext4_inc_count(handle, inode);
2961 ihold(inode);
2962
2963 err = ext4_add_entry(handle, dentry, inode);
2964 if (!err) {
2965 ext4_mark_inode_dirty(handle, inode);
2966 /* this can happen only for tmpfile being
2967 * linked the first time
2968 */
2969 if (inode->i_nlink == 1)
2970 ext4_orphan_del(handle, inode);
2971 d_instantiate(dentry, inode);
2972 } else {
2973 drop_nlink(inode);
2974 iput(inode);
2975 }
2976 ext4_journal_stop(handle);
2977 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2978 goto retry;
2979 return err;
2980 }
2981
2982
2983 /*
2984 * Try to find buffer head where contains the parent block.
2985 * It should be the inode block if it is inlined or the 1st block
2986 * if it is a normal dir.
2987 */
2988 static struct buffer_head *ext4_get_first_dir_block(handle_t *handle,
2989 struct inode *inode,
2990 int *retval,
2991 struct ext4_dir_entry_2 **parent_de,
2992 int *inlined)
2993 {
2994 struct buffer_head *bh;
2995
2996 if (!ext4_has_inline_data(inode)) {
2997 bh = ext4_read_dirblock(inode, 0, EITHER);
2998 if (IS_ERR(bh)) {
2999 *retval = PTR_ERR(bh);
3000 return NULL;
3001 }
3002 *parent_de = ext4_next_entry(
3003 (struct ext4_dir_entry_2 *)bh->b_data,
3004 inode->i_sb->s_blocksize);
3005 return bh;
3006 }
3007
3008 *inlined = 1;
3009 return ext4_get_first_inline_block(inode, parent_de, retval);
3010 }
3011
3012 struct ext4_renament {
3013 struct inode *dir;
3014 struct dentry *dentry;
3015 struct inode *inode;
3016 bool is_dir;
3017 int dir_nlink_delta;
3018
3019 /* entry for "dentry" */
3020 struct buffer_head *bh;
3021 struct ext4_dir_entry_2 *de;
3022 int inlined;
3023
3024 /* entry for ".." in inode if it's a directory */
3025 struct buffer_head *dir_bh;
3026 struct ext4_dir_entry_2 *parent_de;
3027 int dir_inlined;
3028 };
3029
3030 static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent)
3031 {
3032 int retval;
3033
3034 ent->dir_bh = ext4_get_first_dir_block(handle, ent->inode,
3035 &retval, &ent->parent_de,
3036 &ent->dir_inlined);
3037 if (!ent->dir_bh)
3038 return retval;
3039 if (le32_to_cpu(ent->parent_de->inode) != ent->dir->i_ino)
3040 return -EIO;
3041 BUFFER_TRACE(ent->dir_bh, "get_write_access");
3042 return ext4_journal_get_write_access(handle, ent->dir_bh);
3043 }
3044
3045 static int ext4_rename_dir_finish(handle_t *handle, struct ext4_renament *ent,
3046 unsigned dir_ino)
3047 {
3048 int retval;
3049
3050 ent->parent_de->inode = cpu_to_le32(dir_ino);
3051 BUFFER_TRACE(ent->dir_bh, "call ext4_handle_dirty_metadata");
3052 if (!ent->dir_inlined) {
3053 if (is_dx(ent->inode)) {
3054 retval = ext4_handle_dirty_dx_node(handle,
3055 ent->inode,
3056 ent->dir_bh);
3057 } else {
3058 retval = ext4_handle_dirty_dirent_node(handle,
3059 ent->inode,
3060 ent->dir_bh);
3061 }
3062 } else {
3063 retval = ext4_mark_inode_dirty(handle, ent->inode);
3064 }
3065 if (retval) {
3066 ext4_std_error(ent->dir->i_sb, retval);
3067 return retval;
3068 }
3069 return 0;
3070 }
3071
3072 static int ext4_setent(handle_t *handle, struct ext4_renament *ent,
3073 unsigned ino, unsigned file_type)
3074 {
3075 int retval;
3076
3077 BUFFER_TRACE(ent->bh, "get write access");
3078 retval = ext4_journal_get_write_access(handle, ent->bh);
3079 if (retval)
3080 return retval;
3081 ent->de->inode = cpu_to_le32(ino);
3082 if (EXT4_HAS_INCOMPAT_FEATURE(ent->dir->i_sb,
3083 EXT4_FEATURE_INCOMPAT_FILETYPE))
3084 ent->de->file_type = file_type;
3085 ent->dir->i_version++;
3086 ent->dir->i_ctime = ent->dir->i_mtime =
3087 ext4_current_time(ent->dir);
3088 ext4_mark_inode_dirty(handle, ent->dir);
3089 BUFFER_TRACE(ent->bh, "call ext4_handle_dirty_metadata");
3090 if (!ent->inlined) {
3091 retval = ext4_handle_dirty_dirent_node(handle,
3092 ent->dir, ent->bh);
3093 if (unlikely(retval)) {
3094 ext4_std_error(ent->dir->i_sb, retval);
3095 return retval;
3096 }
3097 }
3098 brelse(ent->bh);
3099 ent->bh = NULL;
3100
3101 return 0;
3102 }
3103
3104 static int ext4_find_delete_entry(handle_t *handle, struct inode *dir,
3105 const struct qstr *d_name)
3106 {
3107 int retval = -ENOENT;
3108 struct buffer_head *bh;
3109 struct ext4_dir_entry_2 *de;
3110
3111 bh = ext4_find_entry(dir, d_name, &de, NULL);
3112 if (IS_ERR(bh))
3113 return PTR_ERR(bh);
3114 if (bh) {
3115 retval = ext4_delete_entry(handle, dir, de, bh);
3116 brelse(bh);
3117 }
3118 return retval;
3119 }
3120
3121 static void ext4_rename_delete(handle_t *handle, struct ext4_renament *ent,
3122 int force_reread)
3123 {
3124 int retval;
3125 /*
3126 * ent->de could have moved from under us during htree split, so make
3127 * sure that we are deleting the right entry. We might also be pointing
3128 * to a stale entry in the unused part of ent->bh so just checking inum
3129 * and the name isn't enough.
3130 */
3131 if (le32_to_cpu(ent->de->inode) != ent->inode->i_ino ||
3132 ent->de->name_len != ent->dentry->d_name.len ||
3133 strncmp(ent->de->name, ent->dentry->d_name.name,
3134 ent->de->name_len) ||
3135 force_reread) {
3136 retval = ext4_find_delete_entry(handle, ent->dir,
3137 &ent->dentry->d_name);
3138 } else {
3139 retval = ext4_delete_entry(handle, ent->dir, ent->de, ent->bh);
3140 if (retval == -ENOENT) {
3141 retval = ext4_find_delete_entry(handle, ent->dir,
3142 &ent->dentry->d_name);
3143 }
3144 }
3145
3146 if (retval) {
3147 ext4_warning(ent->dir->i_sb,
3148 "Deleting old file (%lu), %d, error=%d",
3149 ent->dir->i_ino, ent->dir->i_nlink, retval);
3150 }
3151 }
3152
3153 static void ext4_update_dir_count(handle_t *handle, struct ext4_renament *ent)
3154 {
3155 if (ent->dir_nlink_delta) {
3156 if (ent->dir_nlink_delta == -1)
3157 ext4_dec_count(handle, ent->dir);
3158 else
3159 ext4_inc_count(handle, ent->dir);
3160 ext4_mark_inode_dirty(handle, ent->dir);
3161 }
3162 }
3163
3164 /*
3165 * Anybody can rename anything with this: the permission checks are left to the
3166 * higher-level routines.
3167 *
3168 * n.b. old_{dentry,inode) refers to the source dentry/inode
3169 * while new_{dentry,inode) refers to the destination dentry/inode
3170 * This comes from rename(const char *oldpath, const char *newpath)
3171 */
3172 static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
3173 struct inode *new_dir, struct dentry *new_dentry)
3174 {
3175 handle_t *handle = NULL;
3176 struct ext4_renament old = {
3177 .dir = old_dir,
3178 .dentry = old_dentry,
3179 .inode = old_dentry->d_inode,
3180 };
3181 struct ext4_renament new = {
3182 .dir = new_dir,
3183 .dentry = new_dentry,
3184 .inode = new_dentry->d_inode,
3185 };
3186 int force_reread;
3187 int retval;
3188
3189 dquot_initialize(old.dir);
3190 dquot_initialize(new.dir);
3191
3192 /* Initialize quotas before so that eventual writes go
3193 * in separate transaction */
3194 if (new.inode)
3195 dquot_initialize(new.inode);
3196
3197 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, NULL);
3198 if (IS_ERR(old.bh))
3199 return PTR_ERR(old.bh);
3200 /*
3201 * Check for inode number is _not_ due to possible IO errors.
3202 * We might rmdir the source, keep it as pwd of some process
3203 * and merrily kill the link to whatever was created under the
3204 * same name. Goodbye sticky bit ;-<
3205 */
3206 retval = -ENOENT;
3207 if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3208 goto end_rename;
3209
3210 new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
3211 &new.de, &new.inlined);
3212 if (IS_ERR(new.bh)) {
3213 retval = PTR_ERR(new.bh);
3214 goto end_rename;
3215 }
3216 if (new.bh) {
3217 if (!new.inode) {
3218 brelse(new.bh);
3219 new.bh = NULL;
3220 }
3221 }
3222 if (new.inode && !test_opt(new.dir->i_sb, NO_AUTO_DA_ALLOC))
3223 ext4_alloc_da_blocks(old.inode);
3224
3225 handle = ext4_journal_start(old.dir, EXT4_HT_DIR,
3226 (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3227 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2));
3228 if (IS_ERR(handle))
3229 return PTR_ERR(handle);
3230
3231 if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3232 ext4_handle_sync(handle);
3233
3234 if (S_ISDIR(old.inode->i_mode)) {
3235 if (new.inode) {
3236 retval = -ENOTEMPTY;
3237 if (!empty_dir(new.inode))
3238 goto end_rename;
3239 } else {
3240 retval = -EMLINK;
3241 if (new.dir != old.dir && EXT4_DIR_LINK_MAX(new.dir))
3242 goto end_rename;
3243 }
3244 retval = ext4_rename_dir_prepare(handle, &old);
3245 if (retval)
3246 goto end_rename;
3247 }
3248 /*
3249 * If we're renaming a file within an inline_data dir and adding or
3250 * setting the new dirent causes a conversion from inline_data to
3251 * extents/blockmap, we need to force the dirent delete code to
3252 * re-read the directory, or else we end up trying to delete a dirent
3253 * from what is now the extent tree root (or a block map).
3254 */
3255 force_reread = (new.dir->i_ino == old.dir->i_ino &&
3256 ext4_test_inode_flag(new.dir, EXT4_INODE_INLINE_DATA));
3257 if (!new.bh) {
3258 retval = ext4_add_entry(handle, new.dentry, old.inode);
3259 if (retval)
3260 goto end_rename;
3261 } else {
3262 retval = ext4_setent(handle, &new,
3263 old.inode->i_ino, old.de->file_type);
3264 if (retval)
3265 goto end_rename;
3266 }
3267 if (force_reread)
3268 force_reread = !ext4_test_inode_flag(new.dir,
3269 EXT4_INODE_INLINE_DATA);
3270
3271 /*
3272 * Like most other Unix systems, set the ctime for inodes on a
3273 * rename.
3274 */
3275 old.inode->i_ctime = ext4_current_time(old.inode);
3276 ext4_mark_inode_dirty(handle, old.inode);
3277
3278 /*
3279 * ok, that's it
3280 */
3281 ext4_rename_delete(handle, &old, force_reread);
3282
3283 if (new.inode) {
3284 ext4_dec_count(handle, new.inode);
3285 new.inode->i_ctime = ext4_current_time(new.inode);
3286 }
3287 old.dir->i_ctime = old.dir->i_mtime = ext4_current_time(old.dir);
3288 ext4_update_dx_flag(old.dir);
3289 if (old.dir_bh) {
3290 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
3291 if (retval)
3292 goto end_rename;
3293
3294 ext4_dec_count(handle, old.dir);
3295 if (new.inode) {
3296 /* checked empty_dir above, can't have another parent,
3297 * ext4_dec_count() won't work for many-linked dirs */
3298 clear_nlink(new.inode);
3299 } else {
3300 ext4_inc_count(handle, new.dir);
3301 ext4_update_dx_flag(new.dir);
3302 ext4_mark_inode_dirty(handle, new.dir);
3303 }
3304 }
3305 ext4_mark_inode_dirty(handle, old.dir);
3306 if (new.inode) {
3307 ext4_mark_inode_dirty(handle, new.inode);
3308 if (!new.inode->i_nlink)
3309 ext4_orphan_add(handle, new.inode);
3310 }
3311 retval = 0;
3312
3313 end_rename:
3314 brelse(old.dir_bh);
3315 brelse(old.bh);
3316 brelse(new.bh);
3317 if (handle)
3318 ext4_journal_stop(handle);
3319 return retval;
3320 }
3321
3322 static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
3323 struct inode *new_dir, struct dentry *new_dentry)
3324 {
3325 handle_t *handle = NULL;
3326 struct ext4_renament old = {
3327 .dir = old_dir,
3328 .dentry = old_dentry,
3329 .inode = old_dentry->d_inode,
3330 };
3331 struct ext4_renament new = {
3332 .dir = new_dir,
3333 .dentry = new_dentry,
3334 .inode = new_dentry->d_inode,
3335 };
3336 u8 new_file_type;
3337 int retval;
3338
3339 dquot_initialize(old.dir);
3340 dquot_initialize(new.dir);
3341
3342 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name,
3343 &old.de, &old.inlined);
3344 if (IS_ERR(old.bh))
3345 return PTR_ERR(old.bh);
3346 /*
3347 * Check for inode number is _not_ due to possible IO errors.
3348 * We might rmdir the source, keep it as pwd of some process
3349 * and merrily kill the link to whatever was created under the
3350 * same name. Goodbye sticky bit ;-<
3351 */
3352 retval = -ENOENT;
3353 if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3354 goto end_rename;
3355
3356 new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
3357 &new.de, &new.inlined);
3358 if (IS_ERR(new.bh)) {
3359 retval = PTR_ERR(new.bh);
3360 goto end_rename;
3361 }
3362
3363 /* RENAME_EXCHANGE case: old *and* new must both exist */
3364 if (!new.bh || le32_to_cpu(new.de->inode) != new.inode->i_ino)
3365 goto end_rename;
3366
3367 handle = ext4_journal_start(old.dir, EXT4_HT_DIR,
3368 (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3369 2 * EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2));
3370 if (IS_ERR(handle))
3371 return PTR_ERR(handle);
3372
3373 if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3374 ext4_handle_sync(handle);
3375
3376 if (S_ISDIR(old.inode->i_mode)) {
3377 old.is_dir = true;
3378 retval = ext4_rename_dir_prepare(handle, &old);
3379 if (retval)
3380 goto end_rename;
3381 }
3382 if (S_ISDIR(new.inode->i_mode)) {
3383 new.is_dir = true;
3384 retval = ext4_rename_dir_prepare(handle, &new);
3385 if (retval)
3386 goto end_rename;
3387 }
3388
3389 /*
3390 * Other than the special case of overwriting a directory, parents'
3391 * nlink only needs to be modified if this is a cross directory rename.
3392 */
3393 if (old.dir != new.dir && old.is_dir != new.is_dir) {
3394 old.dir_nlink_delta = old.is_dir ? -1 : 1;
3395 new.dir_nlink_delta = -old.dir_nlink_delta;
3396 retval = -EMLINK;
3397 if ((old.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(old.dir)) ||
3398 (new.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(new.dir)))
3399 goto end_rename;
3400 }
3401
3402 new_file_type = new.de->file_type;
3403 retval = ext4_setent(handle, &new, old.inode->i_ino, old.de->file_type);
3404 if (retval)
3405 goto end_rename;
3406
3407 retval = ext4_setent(handle, &old, new.inode->i_ino, new_file_type);
3408 if (retval)
3409 goto end_rename;
3410
3411 /*
3412 * Like most other Unix systems, set the ctime for inodes on a
3413 * rename.
3414 */
3415 old.inode->i_ctime = ext4_current_time(old.inode);
3416 new.inode->i_ctime = ext4_current_time(new.inode);
3417 ext4_mark_inode_dirty(handle, old.inode);
3418 ext4_mark_inode_dirty(handle, new.inode);
3419
3420 if (old.dir_bh) {
3421 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
3422 if (retval)
3423 goto end_rename;
3424 }
3425 if (new.dir_bh) {
3426 retval = ext4_rename_dir_finish(handle, &new, old.dir->i_ino);
3427 if (retval)
3428 goto end_rename;
3429 }
3430 ext4_update_dir_count(handle, &old);
3431 ext4_update_dir_count(handle, &new);
3432 retval = 0;
3433
3434 end_rename:
3435 brelse(old.dir_bh);
3436 brelse(new.dir_bh);
3437 brelse(old.bh);
3438 brelse(new.bh);
3439 if (handle)
3440 ext4_journal_stop(handle);
3441 return retval;
3442 }
3443
3444 static int ext4_rename2(struct inode *old_dir, struct dentry *old_dentry,
3445 struct inode *new_dir, struct dentry *new_dentry,
3446 unsigned int flags)
3447 {
3448 if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE))
3449 return -EINVAL;
3450
3451 if (flags & RENAME_EXCHANGE) {
3452 return ext4_cross_rename(old_dir, old_dentry,
3453 new_dir, new_dentry);
3454 }
3455 /*
3456 * Existence checking was done by the VFS, otherwise "RENAME_NOREPLACE"
3457 * is equivalent to regular rename.
3458 */
3459 return ext4_rename(old_dir, old_dentry, new_dir, new_dentry);
3460 }
3461
3462 /*
3463 * directories can handle most operations...
3464 */
3465 const struct inode_operations ext4_dir_inode_operations = {
3466 .create = ext4_create,
3467 .lookup = ext4_lookup,
3468 .link = ext4_link,
3469 .unlink = ext4_unlink,
3470 .symlink = ext4_symlink,
3471 .mkdir = ext4_mkdir,
3472 .rmdir = ext4_rmdir,
3473 .mknod = ext4_mknod,
3474 .tmpfile = ext4_tmpfile,
3475 .rename2 = ext4_rename2,
3476 .setattr = ext4_setattr,
3477 .setxattr = generic_setxattr,
3478 .getxattr = generic_getxattr,
3479 .listxattr = ext4_listxattr,
3480 .removexattr = generic_removexattr,
3481 .get_acl = ext4_get_acl,
3482 .set_acl = ext4_set_acl,
3483 .fiemap = ext4_fiemap,
3484 };
3485
3486 const struct inode_operations ext4_special_inode_operations = {
3487 .setattr = ext4_setattr,
3488 .setxattr = generic_setxattr,
3489 .getxattr = generic_getxattr,
3490 .listxattr = ext4_listxattr,
3491 .removexattr = generic_removexattr,
3492 .get_acl = ext4_get_acl,
3493 .set_acl = ext4_set_acl,
3494 };
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