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kvm tools, setup: Create private directory
[linux-2.6/next.git] / fs / ext4 / namei.c
blobb754b7721f51fea4dd943a68e436fe5677f301a0
1 /*
2 * linux/fs/ext4/namei.c
3 *
4 * Copyright (C) 1992, 1993, 1994, 1995
5 * Remy Card (card@masi.ibp.fr)
6 * Laboratoire MASI - Institut Blaise Pascal
7 * Universite Pierre et Marie Curie (Paris VI)
8 *
9 * from
10 *
11 * linux/fs/minix/namei.c
12 *
13 * Copyright (C) 1991, 1992 Linus Torvalds
14 *
15 * Big-endian to little-endian byte-swapping/bitmaps by
16 * David S. Miller (davem@caip.rutgers.edu), 1995
17 * Directory entry file type support and forward compatibility hooks
18 * for B-tree directories by Theodore Ts'o (tytso@mit.edu), 1998
19 * Hash Tree Directory indexing (c)
20 * Daniel Phillips, 2001
21 * Hash Tree Directory indexing porting
22 * Christopher Li, 2002
23 * Hash Tree Directory indexing cleanup
24 * Theodore Ts'o, 2002
25 */
26
27 #include <linux/fs.h>
28 #include <linux/pagemap.h>
29 #include <linux/jbd2.h>
30 #include <linux/time.h>
31 #include <linux/fcntl.h>
32 #include <linux/stat.h>
33 #include <linux/string.h>
34 #include <linux/quotaops.h>
35 #include <linux/buffer_head.h>
36 #include <linux/bio.h>
37 #include "ext4.h"
38 #include "ext4_jbd2.h"
39
40 #include "xattr.h"
41 #include "acl.h"
42
43 #include <trace/events/ext4.h>
44 /*
45 * define how far ahead to read directories while searching them.
46 */
47 #define NAMEI_RA_CHUNKS 2
48 #define NAMEI_RA_BLOCKS 4
49 #define NAMEI_RA_SIZE (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS)
50 #define NAMEI_RA_INDEX(c,b) (((c) * NAMEI_RA_BLOCKS) + (b))
51
52 static struct buffer_head *ext4_append(handle_t *handle,
53 struct inode *inode,
54 ext4_lblk_t *block, int *err)
55 {
56 struct buffer_head *bh;
57
58 *block = inode->i_size >> inode->i_sb->s_blocksize_bits;
59
60 bh = ext4_bread(handle, inode, *block, 1, err);
61 if (bh) {
62 inode->i_size += inode->i_sb->s_blocksize;
63 EXT4_I(inode)->i_disksize = inode->i_size;
64 *err = ext4_journal_get_write_access(handle, bh);
65 if (*err) {
66 brelse(bh);
67 bh = NULL;
68 }
69 }
70 return bh;
71 }
72
73 #ifndef assert
74 #define assert(test) J_ASSERT(test)
75 #endif
76
77 #ifdef DX_DEBUG
78 #define dxtrace(command) command
79 #else
80 #define dxtrace(command)
81 #endif
82
83 struct fake_dirent
84 {
85 __le32 inode;
86 __le16 rec_len;
87 u8 name_len;
88 u8 file_type;
89 };
90
91 struct dx_countlimit
92 {
93 __le16 limit;
94 __le16 count;
95 };
96
97 struct dx_entry
98 {
99 __le32 hash;
100 __le32 block;
101 };
102
103 /*
104 * dx_root_info is laid out so that if it should somehow get overlaid by a
105 * dirent the two low bits of the hash version will be zero. Therefore, the
106 * hash version mod 4 should never be 0. Sincerely, the paranoia department.
107 */
108
109 struct dx_root
110 {
111 struct fake_dirent dot;
112 char dot_name[4];
113 struct fake_dirent dotdot;
114 char dotdot_name[4];
115 struct dx_root_info
116 {
117 __le32 reserved_zero;
118 u8 hash_version;
119 u8 info_length; /* 8 */
120 u8 indirect_levels;
121 u8 unused_flags;
122 }
123 info;
124 struct dx_entry entries[0];
125 };
126
127 struct dx_node
128 {
129 struct fake_dirent fake;
130 struct dx_entry entries[0];
131 };
132
133
134 struct dx_frame
135 {
136 struct buffer_head *bh;
137 struct dx_entry *entries;
138 struct dx_entry *at;
139 };
140
141 struct dx_map_entry
142 {
143 u32 hash;
144 u16 offs;
145 u16 size;
146 };
147
148 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
149 static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
150 static inline unsigned dx_get_hash(struct dx_entry *entry);
151 static void dx_set_hash(struct dx_entry *entry, unsigned value);
152 static unsigned dx_get_count(struct dx_entry *entries);
153 static unsigned dx_get_limit(struct dx_entry *entries);
154 static void dx_set_count(struct dx_entry *entries, unsigned value);
155 static void dx_set_limit(struct dx_entry *entries, unsigned value);
156 static unsigned dx_root_limit(struct inode *dir, unsigned infosize);
157 static unsigned dx_node_limit(struct inode *dir);
158 static struct dx_frame *dx_probe(const struct qstr *d_name,
159 struct inode *dir,
160 struct dx_hash_info *hinfo,
161 struct dx_frame *frame,
162 int *err);
163 static void dx_release(struct dx_frame *frames);
164 static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize,
165 struct dx_hash_info *hinfo, struct dx_map_entry map[]);
166 static void dx_sort_map(struct dx_map_entry *map, unsigned count);
167 static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to,
168 struct dx_map_entry *offsets, int count, unsigned blocksize);
169 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize);
170 static void dx_insert_block(struct dx_frame *frame,
171 u32 hash, ext4_lblk_t block);
172 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
173 struct dx_frame *frame,
174 struct dx_frame *frames,
175 __u32 *start_hash);
176 static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
177 const struct qstr *d_name,
178 struct ext4_dir_entry_2 **res_dir,
179 int *err);
180 static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
181 struct inode *inode);
182
183 /*
184 * p is at least 6 bytes before the end of page
185 */
186 static inline struct ext4_dir_entry_2 *
187 ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
188 {
189 return (struct ext4_dir_entry_2 *)((char *)p +
190 ext4_rec_len_from_disk(p->rec_len, blocksize));
191 }
192
193 /*
194 * Future: use high four bits of block for coalesce-on-delete flags
195 * Mask them off for now.
196 */
197
198 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
199 {
200 return le32_to_cpu(entry->block) & 0x00ffffff;
201 }
202
203 static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
204 {
205 entry->block = cpu_to_le32(value);
206 }
207
208 static inline unsigned dx_get_hash(struct dx_entry *entry)
209 {
210 return le32_to_cpu(entry->hash);
211 }
212
213 static inline void dx_set_hash(struct dx_entry *entry, unsigned value)
214 {
215 entry->hash = cpu_to_le32(value);
216 }
217
218 static inline unsigned dx_get_count(struct dx_entry *entries)
219 {
220 return le16_to_cpu(((struct dx_countlimit *) entries)->count);
221 }
222
223 static inline unsigned dx_get_limit(struct dx_entry *entries)
224 {
225 return le16_to_cpu(((struct dx_countlimit *) entries)->limit);
226 }
227
228 static inline void dx_set_count(struct dx_entry *entries, unsigned value)
229 {
230 ((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
231 }
232
233 static inline void dx_set_limit(struct dx_entry *entries, unsigned value)
234 {
235 ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
236 }
237
238 static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
239 {
240 unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
241 EXT4_DIR_REC_LEN(2) - infosize;
242 return entry_space / sizeof(struct dx_entry);
243 }
244
245 static inline unsigned dx_node_limit(struct inode *dir)
246 {
247 unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);
248 return entry_space / sizeof(struct dx_entry);
249 }
250
251 /*
252 * Debug
253 */
254 #ifdef DX_DEBUG
255 static void dx_show_index(char * label, struct dx_entry *entries)
256 {
257 int i, n = dx_get_count (entries);
258 printk(KERN_DEBUG "%s index ", label);
259 for (i = 0; i < n; i++) {
260 printk("%x->%lu ", i ? dx_get_hash(entries + i) :
261 0, (unsigned long)dx_get_block(entries + i));
262 }
263 printk("\n");
264 }
265
266 struct stats
267 {
268 unsigned names;
269 unsigned space;
270 unsigned bcount;
271 };
272
273 static struct stats dx_show_leaf(struct dx_hash_info *hinfo, struct ext4_dir_entry_2 *de,
274 int size, int show_names)
275 {
276 unsigned names = 0, space = 0;
277 char *base = (char *) de;
278 struct dx_hash_info h = *hinfo;
279
280 printk("names: ");
281 while ((char *) de < base + size)
282 {
283 if (de->inode)
284 {
285 if (show_names)
286 {
287 int len = de->name_len;
288 char *name = de->name;
289 while (len--) printk("%c", *name++);
290 ext4fs_dirhash(de->name, de->name_len, &h);
291 printk(":%x.%u ", h.hash,
292 ((char *) de - base));
293 }
294 space += EXT4_DIR_REC_LEN(de->name_len);
295 names++;
296 }
297 de = ext4_next_entry(de, size);
298 }
299 printk("(%i)\n", names);
300 return (struct stats) { names, space, 1 };
301 }
302
303 struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
304 struct dx_entry *entries, int levels)
305 {
306 unsigned blocksize = dir->i_sb->s_blocksize;
307 unsigned count = dx_get_count(entries), names = 0, space = 0, i;
308 unsigned bcount = 0;
309 struct buffer_head *bh;
310 int err;
311 printk("%i indexed blocks...\n", count);
312 for (i = 0; i < count; i++, entries++)
313 {
314 ext4_lblk_t block = dx_get_block(entries);
315 ext4_lblk_t hash = i ? dx_get_hash(entries): 0;
316 u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
317 struct stats stats;
318 printk("%s%3u:%03u hash %8x/%8x ",levels?"":" ", i, block, hash, range);
319 if (!(bh = ext4_bread (NULL,dir, block, 0,&err))) continue;
320 stats = levels?
321 dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
322 dx_show_leaf(hinfo, (struct ext4_dir_entry_2 *) bh->b_data, blocksize, 0);
323 names += stats.names;
324 space += stats.space;
325 bcount += stats.bcount;
326 brelse(bh);
327 }
328 if (bcount)
329 printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n",
330 levels ? "" : " ", names, space/bcount,
331 (space/bcount)*100/blocksize);
332 return (struct stats) { names, space, bcount};
333 }
334 #endif /* DX_DEBUG */
335
336 /*
337 * Probe for a directory leaf block to search.
338 *
339 * dx_probe can return ERR_BAD_DX_DIR, which means there was a format
340 * error in the directory index, and the caller should fall back to
341 * searching the directory normally. The callers of dx_probe **MUST**
342 * check for this error code, and make sure it never gets reflected
343 * back to userspace.
344 */
345 static struct dx_frame *
346 dx_probe(const struct qstr *d_name, struct inode *dir,
347 struct dx_hash_info *hinfo, struct dx_frame *frame_in, int *err)
348 {
349 unsigned count, indirect;
350 struct dx_entry *at, *entries, *p, *q, *m;
351 struct dx_root *root;
352 struct buffer_head *bh;
353 struct dx_frame *frame = frame_in;
354 u32 hash;
355
356 frame->bh = NULL;
357 if (!(bh = ext4_bread (NULL,dir, 0, 0, err)))
358 goto fail;
359 root = (struct dx_root *) bh->b_data;
360 if (root->info.hash_version != DX_HASH_TEA &&
361 root->info.hash_version != DX_HASH_HALF_MD4 &&
362 root->info.hash_version != DX_HASH_LEGACY) {
363 ext4_warning(dir->i_sb, "Unrecognised inode hash code %d",
364 root->info.hash_version);
365 brelse(bh);
366 *err = ERR_BAD_DX_DIR;
367 goto fail;
368 }
369 hinfo->hash_version = root->info.hash_version;
370 if (hinfo->hash_version <= DX_HASH_TEA)
371 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
372 hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
373 if (d_name)
374 ext4fs_dirhash(d_name->name, d_name->len, hinfo);
375 hash = hinfo->hash;
376
377 if (root->info.unused_flags & 1) {
378 ext4_warning(dir->i_sb, "Unimplemented inode hash flags: %#06x",
379 root->info.unused_flags);
380 brelse(bh);
381 *err = ERR_BAD_DX_DIR;
382 goto fail;
383 }
384
385 if ((indirect = root->info.indirect_levels) > 1) {
386 ext4_warning(dir->i_sb, "Unimplemented inode hash depth: %#06x",
387 root->info.indirect_levels);
388 brelse(bh);
389 *err = ERR_BAD_DX_DIR;
390 goto fail;
391 }
392
393 entries = (struct dx_entry *) (((char *)&root->info) +
394 root->info.info_length);
395
396 if (dx_get_limit(entries) != dx_root_limit(dir,
397 root->info.info_length)) {
398 ext4_warning(dir->i_sb, "dx entry: limit != root limit");
399 brelse(bh);
400 *err = ERR_BAD_DX_DIR;
401 goto fail;
402 }
403
404 dxtrace(printk("Look up %x", hash));
405 while (1)
406 {
407 count = dx_get_count(entries);
408 if (!count || count > dx_get_limit(entries)) {
409 ext4_warning(dir->i_sb,
410 "dx entry: no count or count > limit");
411 brelse(bh);
412 *err = ERR_BAD_DX_DIR;
413 goto fail2;
414 }
415
416 p = entries + 1;
417 q = entries + count - 1;
418 while (p <= q)
419 {
420 m = p + (q - p)/2;
421 dxtrace(printk("."));
422 if (dx_get_hash(m) > hash)
423 q = m - 1;
424 else
425 p = m + 1;
426 }
427
428 if (0) // linear search cross check
429 {
430 unsigned n = count - 1;
431 at = entries;
432 while (n--)
433 {
434 dxtrace(printk(","));
435 if (dx_get_hash(++at) > hash)
436 {
437 at--;
438 break;
439 }
440 }
441 assert (at == p - 1);
442 }
443
444 at = p - 1;
445 dxtrace(printk(" %x->%u\n", at == entries? 0: dx_get_hash(at), dx_get_block(at)));
446 frame->bh = bh;
447 frame->entries = entries;
448 frame->at = at;
449 if (!indirect--) return frame;
450 if (!(bh = ext4_bread (NULL,dir, dx_get_block(at), 0, err)))
451 goto fail2;
452 at = entries = ((struct dx_node *) bh->b_data)->entries;
453 if (dx_get_limit(entries) != dx_node_limit (dir)) {
454 ext4_warning(dir->i_sb,
455 "dx entry: limit != node limit");
456 brelse(bh);
457 *err = ERR_BAD_DX_DIR;
458 goto fail2;
459 }
460 frame++;
461 frame->bh = NULL;
462 }
463 fail2:
464 while (frame >= frame_in) {
465 brelse(frame->bh);
466 frame--;
467 }
468 fail:
469 if (*err == ERR_BAD_DX_DIR)
470 ext4_warning(dir->i_sb,
471 "Corrupt dir inode %ld, running e2fsck is "
472 "recommended.", dir->i_ino);
473 return NULL;
474 }
475
476 static void dx_release (struct dx_frame *frames)
477 {
478 if (frames[0].bh == NULL)
479 return;
480
481 if (((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels)
482 brelse(frames[1].bh);
483 brelse(frames[0].bh);
484 }
485
486 /*
487 * This function increments the frame pointer to search the next leaf
488 * block, and reads in the necessary intervening nodes if the search
489 * should be necessary. Whether or not the search is necessary is
490 * controlled by the hash parameter. If the hash value is even, then
491 * the search is only continued if the next block starts with that
492 * hash value. This is used if we are searching for a specific file.
493 *
494 * If the hash value is HASH_NB_ALWAYS, then always go to the next block.
495 *
496 * This function returns 1 if the caller should continue to search,
497 * or 0 if it should not. If there is an error reading one of the
498 * index blocks, it will a negative error code.
499 *
500 * If start_hash is non-null, it will be filled in with the starting
501 * hash of the next page.
502 */
503 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
504 struct dx_frame *frame,
505 struct dx_frame *frames,
506 __u32 *start_hash)
507 {
508 struct dx_frame *p;
509 struct buffer_head *bh;
510 int err, num_frames = 0;
511 __u32 bhash;
512
513 p = frame;
514 /*
515 * Find the next leaf page by incrementing the frame pointer.
516 * If we run out of entries in the interior node, loop around and
517 * increment pointer in the parent node. When we break out of
518 * this loop, num_frames indicates the number of interior
519 * nodes need to be read.
520 */
521 while (1) {
522 if (++(p->at) < p->entries + dx_get_count(p->entries))
523 break;
524 if (p == frames)
525 return 0;
526 num_frames++;
527 p--;
528 }
529
530 /*
531 * If the hash is 1, then continue only if the next page has a
532 * continuation hash of any value. This is used for readdir
533 * handling. Otherwise, check to see if the hash matches the
534 * desired contiuation hash. If it doesn't, return since
535 * there's no point to read in the successive index pages.
536 */
537 bhash = dx_get_hash(p->at);
538 if (start_hash)
539 *start_hash = bhash;
540 if ((hash & 1) == 0) {
541 if ((bhash & ~1) != hash)
542 return 0;
543 }
544 /*
545 * If the hash is HASH_NB_ALWAYS, we always go to the next
546 * block so no check is necessary
547 */
548 while (num_frames--) {
549 if (!(bh = ext4_bread(NULL, dir, dx_get_block(p->at),
550 0, &err)))
551 return err; /* Failure */
552 p++;
553 brelse(p->bh);
554 p->bh = bh;
555 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
556 }
557 return 1;
558 }
559
560
561 /*
562 * This function fills a red-black tree with information from a
563 * directory block. It returns the number directory entries loaded
564 * into the tree. If there is an error it is returned in err.
565 */
566 static int htree_dirblock_to_tree(struct file *dir_file,
567 struct inode *dir, ext4_lblk_t block,
568 struct dx_hash_info *hinfo,
569 __u32 start_hash, __u32 start_minor_hash)
570 {
571 struct buffer_head *bh;
572 struct ext4_dir_entry_2 *de, *top;
573 int err, count = 0;
574
575 dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
576 (unsigned long)block));
577 if (!(bh = ext4_bread (NULL, dir, block, 0, &err)))
578 return err;
579
580 de = (struct ext4_dir_entry_2 *) bh->b_data;
581 top = (struct ext4_dir_entry_2 *) ((char *) de +
582 dir->i_sb->s_blocksize -
583 EXT4_DIR_REC_LEN(0));
584 for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) {
585 if (ext4_check_dir_entry(dir, NULL, de, bh,
586 (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
587 + ((char *)de - bh->b_data))) {
588 /* On error, skip the f_pos to the next block. */
589 dir_file->f_pos = (dir_file->f_pos |
590 (dir->i_sb->s_blocksize - 1)) + 1;
591 brelse(bh);
592 return count;
593 }
594 ext4fs_dirhash(de->name, de->name_len, hinfo);
595 if ((hinfo->hash < start_hash) ||
596 ((hinfo->hash == start_hash) &&
597 (hinfo->minor_hash < start_minor_hash)))
598 continue;
599 if (de->inode == 0)
600 continue;
601 if ((err = ext4_htree_store_dirent(dir_file,
602 hinfo->hash, hinfo->minor_hash, de)) != 0) {
603 brelse(bh);
604 return err;
605 }
606 count++;
607 }
608 brelse(bh);
609 return count;
610 }
611
612
613 /*
614 * This function fills a red-black tree with information from a
615 * directory. We start scanning the directory in hash order, starting
616 * at start_hash and start_minor_hash.
617 *
618 * This function returns the number of entries inserted into the tree,
619 * or a negative error code.
620 */
621 int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
622 __u32 start_minor_hash, __u32 *next_hash)
623 {
624 struct dx_hash_info hinfo;
625 struct ext4_dir_entry_2 *de;
626 struct dx_frame frames[2], *frame;
627 struct inode *dir;
628 ext4_lblk_t block;
629 int count = 0;
630 int ret, err;
631 __u32 hashval;
632
633 dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
634 start_hash, start_minor_hash));
635 dir = dir_file->f_path.dentry->d_inode;
636 if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) {
637 hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
638 if (hinfo.hash_version <= DX_HASH_TEA)
639 hinfo.hash_version +=
640 EXT4_SB(dir->i_sb)->s_hash_unsigned;
641 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
642 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
643 start_hash, start_minor_hash);
644 *next_hash = ~0;
645 return count;
646 }
647 hinfo.hash = start_hash;
648 hinfo.minor_hash = 0;
649 frame = dx_probe(NULL, dir, &hinfo, frames, &err);
650 if (!frame)
651 return err;
652
653 /* Add '.' and '..' from the htree header */
654 if (!start_hash && !start_minor_hash) {
655 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
656 if ((err = ext4_htree_store_dirent(dir_file, 0, 0, de)) != 0)
657 goto errout;
658 count++;
659 }
660 if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
661 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
662 de = ext4_next_entry(de, dir->i_sb->s_blocksize);
663 if ((err = ext4_htree_store_dirent(dir_file, 2, 0, de)) != 0)
664 goto errout;
665 count++;
666 }
667
668 while (1) {
669 block = dx_get_block(frame->at);
670 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
671 start_hash, start_minor_hash);
672 if (ret < 0) {
673 err = ret;
674 goto errout;
675 }
676 count += ret;
677 hashval = ~0;
678 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
679 frame, frames, &hashval);
680 *next_hash = hashval;
681 if (ret < 0) {
682 err = ret;
683 goto errout;
684 }
685 /*
686 * Stop if: (a) there are no more entries, or
687 * (b) we have inserted at least one entry and the
688 * next hash value is not a continuation
689 */
690 if ((ret == 0) ||
691 (count && ((hashval & 1) == 0)))
692 break;
693 }
694 dx_release(frames);
695 dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, "
696 "next hash: %x\n", count, *next_hash));
697 return count;
698 errout:
699 dx_release(frames);
700 return (err);
701 }
702
703
704 /*
705 * Directory block splitting, compacting
706 */
707
708 /*
709 * Create map of hash values, offsets, and sizes, stored at end of block.
710 * Returns number of entries mapped.
711 */
712 static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize,
713 struct dx_hash_info *hinfo,
714 struct dx_map_entry *map_tail)
715 {
716 int count = 0;
717 char *base = (char *) de;
718 struct dx_hash_info h = *hinfo;
719
720 while ((char *) de < base + blocksize) {
721 if (de->name_len && de->inode) {
722 ext4fs_dirhash(de->name, de->name_len, &h);
723 map_tail--;
724 map_tail->hash = h.hash;
725 map_tail->offs = ((char *) de - base)>>2;
726 map_tail->size = le16_to_cpu(de->rec_len);
727 count++;
728 cond_resched();
729 }
730 /* XXX: do we need to check rec_len == 0 case? -Chris */
731 de = ext4_next_entry(de, blocksize);
732 }
733 return count;
734 }
735
736 /* Sort map by hash value */
737 static void dx_sort_map (struct dx_map_entry *map, unsigned count)
738 {
739 struct dx_map_entry *p, *q, *top = map + count - 1;
740 int more;
741 /* Combsort until bubble sort doesn't suck */
742 while (count > 2) {
743 count = count*10/13;
744 if (count - 9 < 2) /* 9, 10 -> 11 */
745 count = 11;
746 for (p = top, q = p - count; q >= map; p--, q--)
747 if (p->hash < q->hash)
748 swap(*p, *q);
749 }
750 /* Garden variety bubble sort */
751 do {
752 more = 0;
753 q = top;
754 while (q-- > map) {
755 if (q[1].hash >= q[0].hash)
756 continue;
757 swap(*(q+1), *q);
758 more = 1;
759 }
760 } while(more);
761 }
762
763 static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
764 {
765 struct dx_entry *entries = frame->entries;
766 struct dx_entry *old = frame->at, *new = old + 1;
767 int count = dx_get_count(entries);
768
769 assert(count < dx_get_limit(entries));
770 assert(old < entries + count);
771 memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
772 dx_set_hash(new, hash);
773 dx_set_block(new, block);
774 dx_set_count(entries, count + 1);
775 }
776
777 static void ext4_update_dx_flag(struct inode *inode)
778 {
779 if (!EXT4_HAS_COMPAT_FEATURE(inode->i_sb,
780 EXT4_FEATURE_COMPAT_DIR_INDEX))
781 ext4_clear_inode_flag(inode, EXT4_INODE_INDEX);
782 }
783
784 /*
785 * NOTE! unlike strncmp, ext4_match returns 1 for success, 0 for failure.
786 *
787 * `len <= EXT4_NAME_LEN' is guaranteed by caller.
788 * `de != NULL' is guaranteed by caller.
789 */
790 static inline int ext4_match (int len, const char * const name,
791 struct ext4_dir_entry_2 * de)
792 {
793 if (len != de->name_len)
794 return 0;
795 if (!de->inode)
796 return 0;
797 return !memcmp(name, de->name, len);
798 }
799
800 /*
801 * Returns 0 if not found, -1 on failure, and 1 on success
802 */
803 static inline int search_dirblock(struct buffer_head *bh,
804 struct inode *dir,
805 const struct qstr *d_name,
806 unsigned int offset,
807 struct ext4_dir_entry_2 ** res_dir)
808 {
809 struct ext4_dir_entry_2 * de;
810 char * dlimit;
811 int de_len;
812 const char *name = d_name->name;
813 int namelen = d_name->len;
814
815 de = (struct ext4_dir_entry_2 *) bh->b_data;
816 dlimit = bh->b_data + dir->i_sb->s_blocksize;
817 while ((char *) de < dlimit) {
818 /* this code is executed quadratically often */
819 /* do minimal checking `by hand' */
820
821 if ((char *) de + namelen <= dlimit &&
822 ext4_match (namelen, name, de)) {
823 /* found a match - just to be sure, do a full check */
824 if (ext4_check_dir_entry(dir, NULL, de, bh, offset))
825 return -1;
826 *res_dir = de;
827 return 1;
828 }
829 /* prevent looping on a bad block */
830 de_len = ext4_rec_len_from_disk(de->rec_len,
831 dir->i_sb->s_blocksize);
832 if (de_len <= 0)
833 return -1;
834 offset += de_len;
835 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
836 }
837 return 0;
838 }
839
840
841 /*
842 * ext4_find_entry()
843 *
844 * finds an entry in the specified directory with the wanted name. It
845 * returns the cache buffer in which the entry was found, and the entry
846 * itself (as a parameter - res_dir). It does NOT read the inode of the
847 * entry - you'll have to do that yourself if you want to.
848 *
849 * The returned buffer_head has ->b_count elevated. The caller is expected
850 * to brelse() it when appropriate.
851 */
852 static struct buffer_head * ext4_find_entry (struct inode *dir,
853 const struct qstr *d_name,
854 struct ext4_dir_entry_2 ** res_dir)
855 {
856 struct super_block *sb;
857 struct buffer_head *bh_use[NAMEI_RA_SIZE];
858 struct buffer_head *bh, *ret = NULL;
859 ext4_lblk_t start, block, b;
860 const u8 *name = d_name->name;
861 int ra_max = 0; /* Number of bh's in the readahead
862 buffer, bh_use[] */
863 int ra_ptr = 0; /* Current index into readahead
864 buffer */
865 int num = 0;
866 ext4_lblk_t nblocks;
867 int i, err;
868 int namelen;
869
870 *res_dir = NULL;
871 sb = dir->i_sb;
872 namelen = d_name->len;
873 if (namelen > EXT4_NAME_LEN)
874 return NULL;
875 if ((namelen <= 2) && (name[0] == '.') &&
876 (name[1] == '.' || name[1] == '\0')) {
877 /*
878 * "." or ".." will only be in the first block
879 * NFS may look up ".."; "." should be handled by the VFS
880 */
881 block = start = 0;
882 nblocks = 1;
883 goto restart;
884 }
885 if (is_dx(dir)) {
886 bh = ext4_dx_find_entry(dir, d_name, res_dir, &err);
887 /*
888 * On success, or if the error was file not found,
889 * return. Otherwise, fall back to doing a search the
890 * old fashioned way.
891 */
892 if (bh || (err != ERR_BAD_DX_DIR))
893 return bh;
894 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
895 "falling back\n"));
896 }
897 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
898 start = EXT4_I(dir)->i_dir_start_lookup;
899 if (start >= nblocks)
900 start = 0;
901 block = start;
902 restart:
903 do {
904 /*
905 * We deal with the read-ahead logic here.
906 */
907 if (ra_ptr >= ra_max) {
908 /* Refill the readahead buffer */
909 ra_ptr = 0;
910 b = block;
911 for (ra_max = 0; ra_max < NAMEI_RA_SIZE; ra_max++) {
912 /*
913 * Terminate if we reach the end of the
914 * directory and must wrap, or if our
915 * search has finished at this block.
916 */
917 if (b >= nblocks || (num && block == start)) {
918 bh_use[ra_max] = NULL;
919 break;
920 }
921 num++;
922 bh = ext4_getblk(NULL, dir, b++, 0, &err);
923 bh_use[ra_max] = bh;
924 if (bh)
925 ll_rw_block(READ_META, 1, &bh);
926 }
927 }
928 if ((bh = bh_use[ra_ptr++]) == NULL)
929 goto next;
930 wait_on_buffer(bh);
931 if (!buffer_uptodate(bh)) {
932 /* read error, skip block & hope for the best */
933 EXT4_ERROR_INODE(dir, "reading directory lblock %lu",
934 (unsigned long) block);
935 brelse(bh);
936 goto next;
937 }
938 i = search_dirblock(bh, dir, d_name,
939 block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
940 if (i == 1) {
941 EXT4_I(dir)->i_dir_start_lookup = block;
942 ret = bh;
943 goto cleanup_and_exit;
944 } else {
945 brelse(bh);
946 if (i < 0)
947 goto cleanup_and_exit;
948 }
949 next:
950 if (++block >= nblocks)
951 block = 0;
952 } while (block != start);
953
954 /*
955 * If the directory has grown while we were searching, then
956 * search the last part of the directory before giving up.
957 */
958 block = nblocks;
959 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
960 if (block < nblocks) {
961 start = 0;
962 goto restart;
963 }
964
965 cleanup_and_exit:
966 /* Clean up the read-ahead blocks */
967 for (; ra_ptr < ra_max; ra_ptr++)
968 brelse(bh_use[ra_ptr]);
969 return ret;
970 }
971
972 static struct buffer_head * ext4_dx_find_entry(struct inode *dir, const struct qstr *d_name,
973 struct ext4_dir_entry_2 **res_dir, int *err)
974 {
975 struct super_block * sb = dir->i_sb;
976 struct dx_hash_info hinfo;
977 struct dx_frame frames[2], *frame;
978 struct buffer_head *bh;
979 ext4_lblk_t block;
980 int retval;
981
982 if (!(frame = dx_probe(d_name, dir, &hinfo, frames, err)))
983 return NULL;
984 do {
985 block = dx_get_block(frame->at);
986 if (!(bh = ext4_bread(NULL, dir, block, 0, err)))
987 goto errout;
988
989 retval = search_dirblock(bh, dir, d_name,
990 block << EXT4_BLOCK_SIZE_BITS(sb),
991 res_dir);
992 if (retval == 1) { /* Success! */
993 dx_release(frames);
994 return bh;
995 }
996 brelse(bh);
997 if (retval == -1) {
998 *err = ERR_BAD_DX_DIR;
999 goto errout;
1000 }
1001
1002 /* Check to see if we should continue to search */
1003 retval = ext4_htree_next_block(dir, hinfo.hash, frame,
1004 frames, NULL);
1005 if (retval < 0) {
1006 ext4_warning(sb,
1007 "error reading index page in directory #%lu",
1008 dir->i_ino);
1009 *err = retval;
1010 goto errout;
1011 }
1012 } while (retval == 1);
1013
1014 *err = -ENOENT;
1015 errout:
1016 dxtrace(printk(KERN_DEBUG "%s not found\n", name));
1017 dx_release (frames);
1018 return NULL;
1019 }
1020
1021 static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
1022 {
1023 struct inode *inode;
1024 struct ext4_dir_entry_2 *de;
1025 struct buffer_head *bh;
1026
1027 if (dentry->d_name.len > EXT4_NAME_LEN)
1028 return ERR_PTR(-ENAMETOOLONG);
1029
1030 bh = ext4_find_entry(dir, &dentry->d_name, &de);
1031 inode = NULL;
1032 if (bh) {
1033 __u32 ino = le32_to_cpu(de->inode);
1034 brelse(bh);
1035 if (!ext4_valid_inum(dir->i_sb, ino)) {
1036 EXT4_ERROR_INODE(dir, "bad inode number: %u", ino);
1037 return ERR_PTR(-EIO);
1038 }
1039 inode = ext4_iget(dir->i_sb, ino);
1040 if (IS_ERR(inode)) {
1041 if (PTR_ERR(inode) == -ESTALE) {
1042 EXT4_ERROR_INODE(dir,
1043 "deleted inode referenced: %u",
1044 ino);
1045 return ERR_PTR(-EIO);
1046 } else {
1047 return ERR_CAST(inode);
1048 }
1049 }
1050 }
1051 return d_splice_alias(inode, dentry);
1052 }
1053
1054
1055 struct dentry *ext4_get_parent(struct dentry *child)
1056 {
1057 __u32 ino;
1058 static const struct qstr dotdot = {
1059 .name = "..",
1060 .len = 2,
1061 };
1062 struct ext4_dir_entry_2 * de;
1063 struct buffer_head *bh;
1064
1065 bh = ext4_find_entry(child->d_inode, &dotdot, &de);
1066 if (!bh)
1067 return ERR_PTR(-ENOENT);
1068 ino = le32_to_cpu(de->inode);
1069 brelse(bh);
1070
1071 if (!ext4_valid_inum(child->d_inode->i_sb, ino)) {
1072 EXT4_ERROR_INODE(child->d_inode,
1073 "bad parent inode number: %u", ino);
1074 return ERR_PTR(-EIO);
1075 }
1076
1077 return d_obtain_alias(ext4_iget(child->d_inode->i_sb, ino));
1078 }
1079
1080 #define S_SHIFT 12
1081 static unsigned char ext4_type_by_mode[S_IFMT >> S_SHIFT] = {
1082 [S_IFREG >> S_SHIFT] = EXT4_FT_REG_FILE,
1083 [S_IFDIR >> S_SHIFT] = EXT4_FT_DIR,
1084 [S_IFCHR >> S_SHIFT] = EXT4_FT_CHRDEV,
1085 [S_IFBLK >> S_SHIFT] = EXT4_FT_BLKDEV,
1086 [S_IFIFO >> S_SHIFT] = EXT4_FT_FIFO,
1087 [S_IFSOCK >> S_SHIFT] = EXT4_FT_SOCK,
1088 [S_IFLNK >> S_SHIFT] = EXT4_FT_SYMLINK,
1089 };
1090
1091 static inline void ext4_set_de_type(struct super_block *sb,
1092 struct ext4_dir_entry_2 *de,
1093 umode_t mode) {
1094 if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE))
1095 de->file_type = ext4_type_by_mode[(mode & S_IFMT)>>S_SHIFT];
1096 }
1097
1098 /*
1099 * Move count entries from end of map between two memory locations.
1100 * Returns pointer to last entry moved.
1101 */
1102 static struct ext4_dir_entry_2 *
1103 dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count,
1104 unsigned blocksize)
1105 {
1106 unsigned rec_len = 0;
1107
1108 while (count--) {
1109 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
1110 (from + (map->offs<<2));
1111 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1112 memcpy (to, de, rec_len);
1113 ((struct ext4_dir_entry_2 *) to)->rec_len =
1114 ext4_rec_len_to_disk(rec_len, blocksize);
1115 de->inode = 0;
1116 map++;
1117 to += rec_len;
1118 }
1119 return (struct ext4_dir_entry_2 *) (to - rec_len);
1120 }
1121
1122 /*
1123 * Compact each dir entry in the range to the minimal rec_len.
1124 * Returns pointer to last entry in range.
1125 */
1126 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize)
1127 {
1128 struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
1129 unsigned rec_len = 0;
1130
1131 prev = to = de;
1132 while ((char*)de < base + blocksize) {
1133 next = ext4_next_entry(de, blocksize);
1134 if (de->inode && de->name_len) {
1135 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1136 if (de > to)
1137 memmove(to, de, rec_len);
1138 to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
1139 prev = to;
1140 to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
1141 }
1142 de = next;
1143 }
1144 return prev;
1145 }
1146
1147 /*
1148 * Split a full leaf block to make room for a new dir entry.
1149 * Allocate a new block, and move entries so that they are approx. equally full.
1150 * Returns pointer to de in block into which the new entry will be inserted.
1151 */
1152 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
1153 struct buffer_head **bh,struct dx_frame *frame,
1154 struct dx_hash_info *hinfo, int *error)
1155 {
1156 unsigned blocksize = dir->i_sb->s_blocksize;
1157 unsigned count, continued;
1158 struct buffer_head *bh2;
1159 ext4_lblk_t newblock;
1160 u32 hash2;
1161 struct dx_map_entry *map;
1162 char *data1 = (*bh)->b_data, *data2;
1163 unsigned split, move, size;
1164 struct ext4_dir_entry_2 *de = NULL, *de2;
1165 int err = 0, i;
1166
1167 bh2 = ext4_append (handle, dir, &newblock, &err);
1168 if (!(bh2)) {
1169 brelse(*bh);
1170 *bh = NULL;
1171 goto errout;
1172 }
1173
1174 BUFFER_TRACE(*bh, "get_write_access");
1175 err = ext4_journal_get_write_access(handle, *bh);
1176 if (err)
1177 goto journal_error;
1178
1179 BUFFER_TRACE(frame->bh, "get_write_access");
1180 err = ext4_journal_get_write_access(handle, frame->bh);
1181 if (err)
1182 goto journal_error;
1183
1184 data2 = bh2->b_data;
1185
1186 /* create map in the end of data2 block */
1187 map = (struct dx_map_entry *) (data2 + blocksize);
1188 count = dx_make_map((struct ext4_dir_entry_2 *) data1,
1189 blocksize, hinfo, map);
1190 map -= count;
1191 dx_sort_map(map, count);
1192 /* Split the existing block in the middle, size-wise */
1193 size = 0;
1194 move = 0;
1195 for (i = count-1; i >= 0; i--) {
1196 /* is more than half of this entry in 2nd half of the block? */
1197 if (size + map[i].size/2 > blocksize/2)
1198 break;
1199 size += map[i].size;
1200 move++;
1201 }
1202 /* map index at which we will split */
1203 split = count - move;
1204 hash2 = map[split].hash;
1205 continued = hash2 == map[split - 1].hash;
1206 dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
1207 (unsigned long)dx_get_block(frame->at),
1208 hash2, split, count-split));
1209
1210 /* Fancy dance to stay within two buffers */
1211 de2 = dx_move_dirents(data1, data2, map + split, count - split, blocksize);
1212 de = dx_pack_dirents(data1, blocksize);
1213 de->rec_len = ext4_rec_len_to_disk(data1 + blocksize - (char *) de,
1214 blocksize);
1215 de2->rec_len = ext4_rec_len_to_disk(data2 + blocksize - (char *) de2,
1216 blocksize);
1217 dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data1, blocksize, 1));
1218 dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data2, blocksize, 1));
1219
1220 /* Which block gets the new entry? */
1221 if (hinfo->hash >= hash2)
1222 {
1223 swap(*bh, bh2);
1224 de = de2;
1225 }
1226 dx_insert_block(frame, hash2 + continued, newblock);
1227 err = ext4_handle_dirty_metadata(handle, dir, bh2);
1228 if (err)
1229 goto journal_error;
1230 err = ext4_handle_dirty_metadata(handle, dir, frame->bh);
1231 if (err)
1232 goto journal_error;
1233 brelse(bh2);
1234 dxtrace(dx_show_index("frame", frame->entries));
1235 return de;
1236
1237 journal_error:
1238 brelse(*bh);
1239 brelse(bh2);
1240 *bh = NULL;
1241 ext4_std_error(dir->i_sb, err);
1242 errout:
1243 *error = err;
1244 return NULL;
1245 }
1246
1247 /*
1248 * Add a new entry into a directory (leaf) block. If de is non-NULL,
1249 * it points to a directory entry which is guaranteed to be large
1250 * enough for new directory entry. If de is NULL, then
1251 * add_dirent_to_buf will attempt search the directory block for
1252 * space. It will return -ENOSPC if no space is available, and -EIO
1253 * and -EEXIST if directory entry already exists.
1254 */
1255 static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
1256 struct inode *inode, struct ext4_dir_entry_2 *de,
1257 struct buffer_head *bh)
1258 {
1259 struct inode *dir = dentry->d_parent->d_inode;
1260 const char *name = dentry->d_name.name;
1261 int namelen = dentry->d_name.len;
1262 unsigned int offset = 0;
1263 unsigned int blocksize = dir->i_sb->s_blocksize;
1264 unsigned short reclen;
1265 int nlen, rlen, err;
1266 char *top;
1267
1268 reclen = EXT4_DIR_REC_LEN(namelen);
1269 if (!de) {
1270 de = (struct ext4_dir_entry_2 *)bh->b_data;
1271 top = bh->b_data + blocksize - reclen;
1272 while ((char *) de <= top) {
1273 if (ext4_check_dir_entry(dir, NULL, de, bh, offset))
1274 return -EIO;
1275 if (ext4_match(namelen, name, de))
1276 return -EEXIST;
1277 nlen = EXT4_DIR_REC_LEN(de->name_len);
1278 rlen = ext4_rec_len_from_disk(de->rec_len, blocksize);
1279 if ((de->inode? rlen - nlen: rlen) >= reclen)
1280 break;
1281 de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
1282 offset += rlen;
1283 }
1284 if ((char *) de > top)
1285 return -ENOSPC;
1286 }
1287 BUFFER_TRACE(bh, "get_write_access");
1288 err = ext4_journal_get_write_access(handle, bh);
1289 if (err) {
1290 ext4_std_error(dir->i_sb, err);
1291 return err;
1292 }
1293
1294 /* By now the buffer is marked for journaling */
1295 nlen = EXT4_DIR_REC_LEN(de->name_len);
1296 rlen = ext4_rec_len_from_disk(de->rec_len, blocksize);
1297 if (de->inode) {
1298 struct ext4_dir_entry_2 *de1 = (struct ext4_dir_entry_2 *)((char *)de + nlen);
1299 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, blocksize);
1300 de->rec_len = ext4_rec_len_to_disk(nlen, blocksize);
1301 de = de1;
1302 }
1303 de->file_type = EXT4_FT_UNKNOWN;
1304 if (inode) {
1305 de->inode = cpu_to_le32(inode->i_ino);
1306 ext4_set_de_type(dir->i_sb, de, inode->i_mode);
1307 } else
1308 de->inode = 0;
1309 de->name_len = namelen;
1310 memcpy(de->name, name, namelen);
1311 /*
1312 * XXX shouldn't update any times until successful
1313 * completion of syscall, but too many callers depend
1314 * on this.
1315 *
1316 * XXX similarly, too many callers depend on
1317 * ext4_new_inode() setting the times, but error
1318 * recovery deletes the inode, so the worst that can
1319 * happen is that the times are slightly out of date
1320 * and/or different from the directory change time.
1321 */
1322 dir->i_mtime = dir->i_ctime = ext4_current_time(dir);
1323 ext4_update_dx_flag(dir);
1324 dir->i_version++;
1325 ext4_mark_inode_dirty(handle, dir);
1326 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1327 err = ext4_handle_dirty_metadata(handle, dir, bh);
1328 if (err)
1329 ext4_std_error(dir->i_sb, err);
1330 return 0;
1331 }
1332
1333 /*
1334 * This converts a one block unindexed directory to a 3 block indexed
1335 * directory, and adds the dentry to the indexed directory.
1336 */
1337 static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
1338 struct inode *inode, struct buffer_head *bh)
1339 {
1340 struct inode *dir = dentry->d_parent->d_inode;
1341 const char *name = dentry->d_name.name;
1342 int namelen = dentry->d_name.len;
1343 struct buffer_head *bh2;
1344 struct dx_root *root;
1345 struct dx_frame frames[2], *frame;
1346 struct dx_entry *entries;
1347 struct ext4_dir_entry_2 *de, *de2;
1348 char *data1, *top;
1349 unsigned len;
1350 int retval;
1351 unsigned blocksize;
1352 struct dx_hash_info hinfo;
1353 ext4_lblk_t block;
1354 struct fake_dirent *fde;
1355
1356 blocksize = dir->i_sb->s_blocksize;
1357 dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
1358 retval = ext4_journal_get_write_access(handle, bh);
1359 if (retval) {
1360 ext4_std_error(dir->i_sb, retval);
1361 brelse(bh);
1362 return retval;
1363 }
1364 root = (struct dx_root *) bh->b_data;
1365
1366 /* The 0th block becomes the root, move the dirents out */
1367 fde = &root->dotdot;
1368 de = (struct ext4_dir_entry_2 *)((char *)fde +
1369 ext4_rec_len_from_disk(fde->rec_len, blocksize));
1370 if ((char *) de >= (((char *) root) + blocksize)) {
1371 EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
1372 brelse(bh);
1373 return -EIO;
1374 }
1375 len = ((char *) root) + blocksize - (char *) de;
1376
1377 /* Allocate new block for the 0th block's dirents */
1378 bh2 = ext4_append(handle, dir, &block, &retval);
1379 if (!(bh2)) {
1380 brelse(bh);
1381 return retval;
1382 }
1383 ext4_set_inode_flag(dir, EXT4_INODE_INDEX);
1384 data1 = bh2->b_data;
1385
1386 memcpy (data1, de, len);
1387 de = (struct ext4_dir_entry_2 *) data1;
1388 top = data1 + len;
1389 while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
1390 de = de2;
1391 de->rec_len = ext4_rec_len_to_disk(data1 + blocksize - (char *) de,
1392 blocksize);
1393 /* Initialize the root; the dot dirents already exist */
1394 de = (struct ext4_dir_entry_2 *) (&root->dotdot);
1395 de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
1396 blocksize);
1397 memset (&root->info, 0, sizeof(root->info));
1398 root->info.info_length = sizeof(root->info);
1399 root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
1400 entries = root->entries;
1401 dx_set_block(entries, 1);
1402 dx_set_count(entries, 1);
1403 dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
1404
1405 /* Initialize as for dx_probe */
1406 hinfo.hash_version = root->info.hash_version;
1407 if (hinfo.hash_version <= DX_HASH_TEA)
1408 hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
1409 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
1410 ext4fs_dirhash(name, namelen, &hinfo);
1411 frame = frames;
1412 frame->entries = entries;
1413 frame->at = entries;
1414 frame->bh = bh;
1415 bh = bh2;
1416
1417 ext4_handle_dirty_metadata(handle, dir, frame->bh);
1418 ext4_handle_dirty_metadata(handle, dir, bh);
1419
1420 de = do_split(handle,dir, &bh, frame, &hinfo, &retval);
1421 if (!de) {
1422 /*
1423 * Even if the block split failed, we have to properly write
1424 * out all the changes we did so far. Otherwise we can end up
1425 * with corrupted filesystem.
1426 */
1427 ext4_mark_inode_dirty(handle, dir);
1428 dx_release(frames);
1429 return retval;
1430 }
1431 dx_release(frames);
1432
1433 retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
1434 brelse(bh);
1435 return retval;
1436 }
1437
1438 /*
1439 * ext4_add_entry()
1440 *
1441 * adds a file entry to the specified directory, using the same
1442 * semantics as ext4_find_entry(). It returns NULL if it failed.
1443 *
1444 * NOTE!! The inode part of 'de' is left at 0 - which means you
1445 * may not sleep between calling this and putting something into
1446 * the entry, as someone else might have used it while you slept.
1447 */
1448 static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
1449 struct inode *inode)
1450 {
1451 struct inode *dir = dentry->d_parent->d_inode;
1452 struct buffer_head *bh;
1453 struct ext4_dir_entry_2 *de;
1454 struct super_block *sb;
1455 int retval;
1456 int dx_fallback=0;
1457 unsigned blocksize;
1458 ext4_lblk_t block, blocks;
1459
1460 sb = dir->i_sb;
1461 blocksize = sb->s_blocksize;
1462 if (!dentry->d_name.len)
1463 return -EINVAL;
1464 if (is_dx(dir)) {
1465 retval = ext4_dx_add_entry(handle, dentry, inode);
1466 if (!retval || (retval != ERR_BAD_DX_DIR))
1467 return retval;
1468 ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
1469 dx_fallback++;
1470 ext4_mark_inode_dirty(handle, dir);
1471 }
1472 blocks = dir->i_size >> sb->s_blocksize_bits;
1473 for (block = 0; block < blocks; block++) {
1474 bh = ext4_bread(handle, dir, block, 0, &retval);
1475 if(!bh)
1476 return retval;
1477 retval = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
1478 if (retval != -ENOSPC) {
1479 brelse(bh);
1480 return retval;
1481 }
1482
1483 if (blocks == 1 && !dx_fallback &&
1484 EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX))
1485 return make_indexed_dir(handle, dentry, inode, bh);
1486 brelse(bh);
1487 }
1488 bh = ext4_append(handle, dir, &block, &retval);
1489 if (!bh)
1490 return retval;
1491 de = (struct ext4_dir_entry_2 *) bh->b_data;
1492 de->inode = 0;
1493 de->rec_len = ext4_rec_len_to_disk(blocksize, blocksize);
1494 retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
1495 brelse(bh);
1496 if (retval == 0)
1497 ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY);
1498 return retval;
1499 }
1500
1501 /*
1502 * Returns 0 for success, or a negative error value
1503 */
1504 static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
1505 struct inode *inode)
1506 {
1507 struct dx_frame frames[2], *frame;
1508 struct dx_entry *entries, *at;
1509 struct dx_hash_info hinfo;
1510 struct buffer_head *bh;
1511 struct inode *dir = dentry->d_parent->d_inode;
1512 struct super_block *sb = dir->i_sb;
1513 struct ext4_dir_entry_2 *de;
1514 int err;
1515
1516 frame = dx_probe(&dentry->d_name, dir, &hinfo, frames, &err);
1517 if (!frame)
1518 return err;
1519 entries = frame->entries;
1520 at = frame->at;
1521
1522 if (!(bh = ext4_bread(handle,dir, dx_get_block(frame->at), 0, &err)))
1523 goto cleanup;
1524
1525 BUFFER_TRACE(bh, "get_write_access");
1526 err = ext4_journal_get_write_access(handle, bh);
1527 if (err)
1528 goto journal_error;
1529
1530 err = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
1531 if (err != -ENOSPC)
1532 goto cleanup;
1533
1534 /* Block full, should compress but for now just split */
1535 dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
1536 dx_get_count(entries), dx_get_limit(entries)));
1537 /* Need to split index? */
1538 if (dx_get_count(entries) == dx_get_limit(entries)) {
1539 ext4_lblk_t newblock;
1540 unsigned icount = dx_get_count(entries);
1541 int levels = frame - frames;
1542 struct dx_entry *entries2;
1543 struct dx_node *node2;
1544 struct buffer_head *bh2;
1545
1546 if (levels && (dx_get_count(frames->entries) ==
1547 dx_get_limit(frames->entries))) {
1548 ext4_warning(sb, "Directory index full!");
1549 err = -ENOSPC;
1550 goto cleanup;
1551 }
1552 bh2 = ext4_append (handle, dir, &newblock, &err);
1553 if (!(bh2))
1554 goto cleanup;
1555 node2 = (struct dx_node *)(bh2->b_data);
1556 entries2 = node2->entries;
1557 memset(&node2->fake, 0, sizeof(struct fake_dirent));
1558 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
1559 sb->s_blocksize);
1560 BUFFER_TRACE(frame->bh, "get_write_access");
1561 err = ext4_journal_get_write_access(handle, frame->bh);
1562 if (err)
1563 goto journal_error;
1564 if (levels) {
1565 unsigned icount1 = icount/2, icount2 = icount - icount1;
1566 unsigned hash2 = dx_get_hash(entries + icount1);
1567 dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
1568 icount1, icount2));
1569
1570 BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
1571 err = ext4_journal_get_write_access(handle,
1572 frames[0].bh);
1573 if (err)
1574 goto journal_error;
1575
1576 memcpy((char *) entries2, (char *) (entries + icount1),
1577 icount2 * sizeof(struct dx_entry));
1578 dx_set_count(entries, icount1);
1579 dx_set_count(entries2, icount2);
1580 dx_set_limit(entries2, dx_node_limit(dir));
1581
1582 /* Which index block gets the new entry? */
1583 if (at - entries >= icount1) {
1584 frame->at = at = at - entries - icount1 + entries2;
1585 frame->entries = entries = entries2;
1586 swap(frame->bh, bh2);
1587 }
1588 dx_insert_block(frames + 0, hash2, newblock);
1589 dxtrace(dx_show_index("node", frames[1].entries));
1590 dxtrace(dx_show_index("node",
1591 ((struct dx_node *) bh2->b_data)->entries));
1592 err = ext4_handle_dirty_metadata(handle, inode, bh2);
1593 if (err)
1594 goto journal_error;
1595 brelse (bh2);
1596 } else {
1597 dxtrace(printk(KERN_DEBUG
1598 "Creating second level index...\n"));
1599 memcpy((char *) entries2, (char *) entries,
1600 icount * sizeof(struct dx_entry));
1601 dx_set_limit(entries2, dx_node_limit(dir));
1602
1603 /* Set up root */
1604 dx_set_count(entries, 1);
1605 dx_set_block(entries + 0, newblock);
1606 ((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels = 1;
1607
1608 /* Add new access path frame */
1609 frame = frames + 1;
1610 frame->at = at = at - entries + entries2;
1611 frame->entries = entries = entries2;
1612 frame->bh = bh2;
1613 err = ext4_journal_get_write_access(handle,
1614 frame->bh);
1615 if (err)
1616 goto journal_error;
1617 }
1618 err = ext4_handle_dirty_metadata(handle, inode, frames[0].bh);
1619 if (err) {
1620 ext4_std_error(inode->i_sb, err);
1621 goto cleanup;
1622 }
1623 }
1624 de = do_split(handle, dir, &bh, frame, &hinfo, &err);
1625 if (!de)
1626 goto cleanup;
1627 err = add_dirent_to_buf(handle, dentry, inode, de, bh);
1628 goto cleanup;
1629
1630 journal_error:
1631 ext4_std_error(dir->i_sb, err);
1632 cleanup:
1633 if (bh)
1634 brelse(bh);
1635 dx_release(frames);
1636 return err;
1637 }
1638
1639 /*
1640 * ext4_delete_entry deletes a directory entry by merging it with the
1641 * previous entry
1642 */
1643 static int ext4_delete_entry(handle_t *handle,
1644 struct inode *dir,
1645 struct ext4_dir_entry_2 *de_del,
1646 struct buffer_head *bh)
1647 {
1648 struct ext4_dir_entry_2 *de, *pde;
1649 unsigned int blocksize = dir->i_sb->s_blocksize;
1650 int i, err;
1651
1652 i = 0;
1653 pde = NULL;
1654 de = (struct ext4_dir_entry_2 *) bh->b_data;
1655 while (i < bh->b_size) {
1656 if (ext4_check_dir_entry(dir, NULL, de, bh, i))
1657 return -EIO;
1658 if (de == de_del) {
1659 BUFFER_TRACE(bh, "get_write_access");
1660 err = ext4_journal_get_write_access(handle, bh);
1661 if (unlikely(err)) {
1662 ext4_std_error(dir->i_sb, err);
1663 return err;
1664 }
1665 if (pde)
1666 pde->rec_len = ext4_rec_len_to_disk(
1667 ext4_rec_len_from_disk(pde->rec_len,
1668 blocksize) +
1669 ext4_rec_len_from_disk(de->rec_len,
1670 blocksize),
1671 blocksize);
1672 else
1673 de->inode = 0;
1674 dir->i_version++;
1675 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1676 err = ext4_handle_dirty_metadata(handle, dir, bh);
1677 if (unlikely(err)) {
1678 ext4_std_error(dir->i_sb, err);
1679 return err;
1680 }
1681 return 0;
1682 }
1683 i += ext4_rec_len_from_disk(de->rec_len, blocksize);
1684 pde = de;
1685 de = ext4_next_entry(de, blocksize);
1686 }
1687 return -ENOENT;
1688 }
1689
1690 /*
1691 * DIR_NLINK feature is set if 1) nlinks > EXT4_LINK_MAX or 2) nlinks == 2,
1692 * since this indicates that nlinks count was previously 1.
1693 */
1694 static void ext4_inc_count(handle_t *handle, struct inode *inode)
1695 {
1696 inc_nlink(inode);
1697 if (is_dx(inode) && inode->i_nlink > 1) {
1698 /* limit is 16-bit i_links_count */
1699 if (inode->i_nlink >= EXT4_LINK_MAX || inode->i_nlink == 2) {
1700 inode->i_nlink = 1;
1701 EXT4_SET_RO_COMPAT_FEATURE(inode->i_sb,
1702 EXT4_FEATURE_RO_COMPAT_DIR_NLINK);
1703 }
1704 }
1705 }
1706
1707 /*
1708 * If a directory had nlink == 1, then we should let it be 1. This indicates
1709 * directory has >EXT4_LINK_MAX subdirs.
1710 */
1711 static void ext4_dec_count(handle_t *handle, struct inode *inode)
1712 {
1713 drop_nlink(inode);
1714 if (S_ISDIR(inode->i_mode) && inode->i_nlink == 0)
1715 inc_nlink(inode);
1716 }
1717
1718
1719 static int ext4_add_nondir(handle_t *handle,
1720 struct dentry *dentry, struct inode *inode)
1721 {
1722 int err = ext4_add_entry(handle, dentry, inode);
1723 if (!err) {
1724 ext4_mark_inode_dirty(handle, inode);
1725 d_instantiate(dentry, inode);
1726 unlock_new_inode(inode);
1727 return 0;
1728 }
1729 drop_nlink(inode);
1730 unlock_new_inode(inode);
1731 iput(inode);
1732 return err;
1733 }
1734
1735 /*
1736 * By the time this is called, we already have created
1737 * the directory cache entry for the new file, but it
1738 * is so far negative - it has no inode.
1739 *
1740 * If the create succeeds, we fill in the inode information
1741 * with d_instantiate().
1742 */
1743 static int ext4_create(struct inode *dir, struct dentry *dentry, int mode,
1744 struct nameidata *nd)
1745 {
1746 handle_t *handle;
1747 struct inode *inode;
1748 int err, retries = 0;
1749
1750 dquot_initialize(dir);
1751
1752 retry:
1753 handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
1754 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
1755 EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
1756 if (IS_ERR(handle))
1757 return PTR_ERR(handle);
1758
1759 if (IS_DIRSYNC(dir))
1760 ext4_handle_sync(handle);
1761
1762 inode = ext4_new_inode(handle, dir, mode, &dentry->d_name, 0);
1763 err = PTR_ERR(inode);
1764 if (!IS_ERR(inode)) {
1765 inode->i_op = &ext4_file_inode_operations;
1766 inode->i_fop = &ext4_file_operations;
1767 ext4_set_aops(inode);
1768 err = ext4_add_nondir(handle, dentry, inode);
1769 }
1770 ext4_journal_stop(handle);
1771 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
1772 goto retry;
1773 return err;
1774 }
1775
1776 static int ext4_mknod(struct inode *dir, struct dentry *dentry,
1777 int mode, dev_t rdev)
1778 {
1779 handle_t *handle;
1780 struct inode *inode;
1781 int err, retries = 0;
1782
1783 if (!new_valid_dev(rdev))
1784 return -EINVAL;
1785
1786 dquot_initialize(dir);
1787
1788 retry:
1789 handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
1790 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
1791 EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
1792 if (IS_ERR(handle))
1793 return PTR_ERR(handle);
1794
1795 if (IS_DIRSYNC(dir))
1796 ext4_handle_sync(handle);
1797
1798 inode = ext4_new_inode(handle, dir, mode, &dentry->d_name, 0);
1799 err = PTR_ERR(inode);
1800 if (!IS_ERR(inode)) {
1801 init_special_inode(inode, inode->i_mode, rdev);
1802 #ifdef CONFIG_EXT4_FS_XATTR
1803 inode->i_op = &ext4_special_inode_operations;
1804 #endif
1805 err = ext4_add_nondir(handle, dentry, inode);
1806 }
1807 ext4_journal_stop(handle);
1808 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
1809 goto retry;
1810 return err;
1811 }
1812
1813 static int ext4_mkdir(struct inode *dir, struct dentry *dentry, int mode)
1814 {
1815 handle_t *handle;
1816 struct inode *inode;
1817 struct buffer_head *dir_block = NULL;
1818 struct ext4_dir_entry_2 *de;
1819 unsigned int blocksize = dir->i_sb->s_blocksize;
1820 int err, retries = 0;
1821
1822 if (EXT4_DIR_LINK_MAX(dir))
1823 return -EMLINK;
1824
1825 dquot_initialize(dir);
1826
1827 retry:
1828 handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
1829 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
1830 EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
1831 if (IS_ERR(handle))
1832 return PTR_ERR(handle);
1833
1834 if (IS_DIRSYNC(dir))
1835 ext4_handle_sync(handle);
1836
1837 inode = ext4_new_inode(handle, dir, S_IFDIR | mode,
1838 &dentry->d_name, 0);
1839 err = PTR_ERR(inode);
1840 if (IS_ERR(inode))
1841 goto out_stop;
1842
1843 inode->i_op = &ext4_dir_inode_operations;
1844 inode->i_fop = &ext4_dir_operations;
1845 inode->i_size = EXT4_I(inode)->i_disksize = inode->i_sb->s_blocksize;
1846 dir_block = ext4_bread(handle, inode, 0, 1, &err);
1847 if (!dir_block)
1848 goto out_clear_inode;
1849 BUFFER_TRACE(dir_block, "get_write_access");
1850 err = ext4_journal_get_write_access(handle, dir_block);
1851 if (err)
1852 goto out_clear_inode;
1853 de = (struct ext4_dir_entry_2 *) dir_block->b_data;
1854 de->inode = cpu_to_le32(inode->i_ino);
1855 de->name_len = 1;
1856 de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
1857 blocksize);
1858 strcpy(de->name, ".");
1859 ext4_set_de_type(dir->i_sb, de, S_IFDIR);
1860 de = ext4_next_entry(de, blocksize);
1861 de->inode = cpu_to_le32(dir->i_ino);
1862 de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(1),
1863 blocksize);
1864 de->name_len = 2;
1865 strcpy(de->name, "..");
1866 ext4_set_de_type(dir->i_sb, de, S_IFDIR);
1867 inode->i_nlink = 2;
1868 BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
1869 err = ext4_handle_dirty_metadata(handle, dir, dir_block);
1870 if (err)
1871 goto out_clear_inode;
1872 err = ext4_mark_inode_dirty(handle, inode);
1873 if (!err)
1874 err = ext4_add_entry(handle, dentry, inode);
1875 if (err) {
1876 out_clear_inode:
1877 clear_nlink(inode);
1878 unlock_new_inode(inode);
1879 ext4_mark_inode_dirty(handle, inode);
1880 iput(inode);
1881 goto out_stop;
1882 }
1883 ext4_inc_count(handle, dir);
1884 ext4_update_dx_flag(dir);
1885 err = ext4_mark_inode_dirty(handle, dir);
1886 if (err)
1887 goto out_clear_inode;
1888 d_instantiate(dentry, inode);
1889 unlock_new_inode(inode);
1890 out_stop:
1891 brelse(dir_block);
1892 ext4_journal_stop(handle);
1893 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
1894 goto retry;
1895 return err;
1896 }
1897
1898 /*
1899 * routine to check that the specified directory is empty (for rmdir)
1900 */
1901 static int empty_dir(struct inode *inode)
1902 {
1903 unsigned int offset;
1904 struct buffer_head *bh;
1905 struct ext4_dir_entry_2 *de, *de1;
1906 struct super_block *sb;
1907 int err = 0;
1908
1909 sb = inode->i_sb;
1910 if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2) ||
1911 !(bh = ext4_bread(NULL, inode, 0, 0, &err))) {
1912 if (err)
1913 EXT4_ERROR_INODE(inode,
1914 "error %d reading directory lblock 0", err);
1915 else
1916 ext4_warning(inode->i_sb,
1917 "bad directory (dir #%lu) - no data block",
1918 inode->i_ino);
1919 return 1;
1920 }
1921 de = (struct ext4_dir_entry_2 *) bh->b_data;
1922 de1 = ext4_next_entry(de, sb->s_blocksize);
1923 if (le32_to_cpu(de->inode) != inode->i_ino ||
1924 !le32_to_cpu(de1->inode) ||
1925 strcmp(".", de->name) ||
1926 strcmp("..", de1->name)) {
1927 ext4_warning(inode->i_sb,
1928 "bad directory (dir #%lu) - no `.' or `..'",
1929 inode->i_ino);
1930 brelse(bh);
1931 return 1;
1932 }
1933 offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) +
1934 ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize);
1935 de = ext4_next_entry(de1, sb->s_blocksize);
1936 while (offset < inode->i_size) {
1937 if (!bh ||
1938 (void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
1939 unsigned int lblock;
1940 err = 0;
1941 brelse(bh);
1942 lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb);
1943 bh = ext4_bread(NULL, inode, lblock, 0, &err);
1944 if (!bh) {
1945 if (err)
1946 EXT4_ERROR_INODE(inode,
1947 "error %d reading directory "
1948 "lblock %u", err, lblock);
1949 offset += sb->s_blocksize;
1950 continue;
1951 }
1952 de = (struct ext4_dir_entry_2 *) bh->b_data;
1953 }
1954 if (ext4_check_dir_entry(inode, NULL, de, bh, offset)) {
1955 de = (struct ext4_dir_entry_2 *)(bh->b_data +
1956 sb->s_blocksize);
1957 offset = (offset | (sb->s_blocksize - 1)) + 1;
1958 continue;
1959 }
1960 if (le32_to_cpu(de->inode)) {
1961 brelse(bh);
1962 return 0;
1963 }
1964 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
1965 de = ext4_next_entry(de, sb->s_blocksize);
1966 }
1967 brelse(bh);
1968 return 1;
1969 }
1970
1971 /* ext4_orphan_add() links an unlinked or truncated inode into a list of
1972 * such inodes, starting at the superblock, in case we crash before the
1973 * file is closed/deleted, or in case the inode truncate spans multiple
1974 * transactions and the last transaction is not recovered after a crash.
1975 *
1976 * At filesystem recovery time, we walk this list deleting unlinked
1977 * inodes and truncating linked inodes in ext4_orphan_cleanup().
1978 */
1979 int ext4_orphan_add(handle_t *handle, struct inode *inode)
1980 {
1981 struct super_block *sb = inode->i_sb;
1982 struct ext4_iloc iloc;
1983 int err = 0, rc;
1984
1985 if (!ext4_handle_valid(handle))
1986 return 0;
1987
1988 mutex_lock(&EXT4_SB(sb)->s_orphan_lock);
1989 if (!list_empty(&EXT4_I(inode)->i_orphan))
1990 goto out_unlock;
1991
1992 /* Orphan handling is only valid for files with data blocks
1993 * being truncated, or files being unlinked. */
1994
1995 /* @@@ FIXME: Observation from aviro:
1996 * I think I can trigger J_ASSERT in ext4_orphan_add(). We block
1997 * here (on s_orphan_lock), so race with ext4_link() which might bump
1998 * ->i_nlink. For, say it, character device. Not a regular file,
1999 * not a directory, not a symlink and ->i_nlink > 0.
2000 *
2001 * tytso, 4/25/2009: I'm not sure how that could happen;
2002 * shouldn't the fs core protect us from these sort of
2003 * unlink()/link() races?
2004 */
2005 J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2006 S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
2007
2008 BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access");
2009 err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
2010 if (err)
2011 goto out_unlock;
2012
2013 err = ext4_reserve_inode_write(handle, inode, &iloc);
2014 if (err)
2015 goto out_unlock;
2016 /*
2017 * Due to previous errors inode may be already a part of on-disk
2018 * orphan list. If so skip on-disk list modification.
2019 */
2020 if (NEXT_ORPHAN(inode) && NEXT_ORPHAN(inode) <=
2021 (le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count)))
2022 goto mem_insert;
2023
2024 /* Insert this inode at the head of the on-disk orphan list... */
2025 NEXT_ORPHAN(inode) = le32_to_cpu(EXT4_SB(sb)->s_es->s_last_orphan);
2026 EXT4_SB(sb)->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
2027 err = ext4_handle_dirty_metadata(handle, NULL, EXT4_SB(sb)->s_sbh);
2028 rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
2029 if (!err)
2030 err = rc;
2031
2032 /* Only add to the head of the in-memory list if all the
2033 * previous operations succeeded. If the orphan_add is going to
2034 * fail (possibly taking the journal offline), we can't risk
2035 * leaving the inode on the orphan list: stray orphan-list
2036 * entries can cause panics at unmount time.
2037 *
2038 * This is safe: on error we're going to ignore the orphan list
2039 * anyway on the next recovery. */
2040 mem_insert:
2041 if (!err)
2042 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2043
2044 jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
2045 jbd_debug(4, "orphan inode %lu will point to %d\n",
2046 inode->i_ino, NEXT_ORPHAN(inode));
2047 out_unlock:
2048 mutex_unlock(&EXT4_SB(sb)->s_orphan_lock);
2049 ext4_std_error(inode->i_sb, err);
2050 return err;
2051 }
2052
2053 /*
2054 * ext4_orphan_del() removes an unlinked or truncated inode from the list
2055 * of such inodes stored on disk, because it is finally being cleaned up.
2056 */
2057 int ext4_orphan_del(handle_t *handle, struct inode *inode)
2058 {
2059 struct list_head *prev;
2060 struct ext4_inode_info *ei = EXT4_I(inode);
2061 struct ext4_sb_info *sbi;
2062 __u32 ino_next;
2063 struct ext4_iloc iloc;
2064 int err = 0;
2065
2066 /* ext4_handle_valid() assumes a valid handle_t pointer */
2067 if (handle && !ext4_handle_valid(handle))
2068 return 0;
2069
2070 mutex_lock(&EXT4_SB(inode->i_sb)->s_orphan_lock);
2071 if (list_empty(&ei->i_orphan))
2072 goto out;
2073
2074 ino_next = NEXT_ORPHAN(inode);
2075 prev = ei->i_orphan.prev;
2076 sbi = EXT4_SB(inode->i_sb);
2077
2078 jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
2079
2080 list_del_init(&ei->i_orphan);
2081
2082 /* If we're on an error path, we may not have a valid
2083 * transaction handle with which to update the orphan list on
2084 * disk, but we still need to remove the inode from the linked
2085 * list in memory. */
2086 if (sbi->s_journal && !handle)
2087 goto out;
2088
2089 err = ext4_reserve_inode_write(handle, inode, &iloc);
2090 if (err)
2091 goto out_err;
2092
2093 if (prev == &sbi->s_orphan) {
2094 jbd_debug(4, "superblock will point to %u\n", ino_next);
2095 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2096 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2097 if (err)
2098 goto out_brelse;
2099 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
2100 err = ext4_handle_dirty_metadata(handle, NULL, sbi->s_sbh);
2101 } else {
2102 struct ext4_iloc iloc2;
2103 struct inode *i_prev =
2104 &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
2105
2106 jbd_debug(4, "orphan inode %lu will point to %u\n",
2107 i_prev->i_ino, ino_next);
2108 err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
2109 if (err)
2110 goto out_brelse;
2111 NEXT_ORPHAN(i_prev) = ino_next;
2112 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
2113 }
2114 if (err)
2115 goto out_brelse;
2116 NEXT_ORPHAN(inode) = 0;
2117 err = ext4_mark_iloc_dirty(handle, inode, &iloc);
2118
2119 out_err:
2120 ext4_std_error(inode->i_sb, err);
2121 out:
2122 mutex_unlock(&EXT4_SB(inode->i_sb)->s_orphan_lock);
2123 return err;
2124
2125 out_brelse:
2126 brelse(iloc.bh);
2127 goto out_err;
2128 }
2129
2130 static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
2131 {
2132 int retval;
2133 struct inode *inode;
2134 struct buffer_head *bh;
2135 struct ext4_dir_entry_2 *de;
2136 handle_t *handle;
2137
2138 /* Initialize quotas before so that eventual writes go in
2139 * separate transaction */
2140 dquot_initialize(dir);
2141 dquot_initialize(dentry->d_inode);
2142
2143 handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb));
2144 if (IS_ERR(handle))
2145 return PTR_ERR(handle);
2146
2147 retval = -ENOENT;
2148 bh = ext4_find_entry(dir, &dentry->d_name, &de);
2149 if (!bh)
2150 goto end_rmdir;
2151
2152 if (IS_DIRSYNC(dir))
2153 ext4_handle_sync(handle);
2154
2155 inode = dentry->d_inode;
2156
2157 retval = -EIO;
2158 if (le32_to_cpu(de->inode) != inode->i_ino)
2159 goto end_rmdir;
2160
2161 retval = -ENOTEMPTY;
2162 if (!empty_dir(inode))
2163 goto end_rmdir;
2164
2165 retval = ext4_delete_entry(handle, dir, de, bh);
2166 if (retval)
2167 goto end_rmdir;
2168 if (!EXT4_DIR_LINK_EMPTY(inode))
2169 ext4_warning(inode->i_sb,
2170 "empty directory has too many links (%d)",
2171 inode->i_nlink);
2172 inode->i_version++;
2173 clear_nlink(inode);
2174 /* There's no need to set i_disksize: the fact that i_nlink is
2175 * zero will ensure that the right thing happens during any
2176 * recovery. */
2177 inode->i_size = 0;
2178 ext4_orphan_add(handle, inode);
2179 inode->i_ctime = dir->i_ctime = dir->i_mtime = ext4_current_time(inode);
2180 ext4_mark_inode_dirty(handle, inode);
2181 ext4_dec_count(handle, dir);
2182 ext4_update_dx_flag(dir);
2183 ext4_mark_inode_dirty(handle, dir);
2184
2185 end_rmdir:
2186 ext4_journal_stop(handle);
2187 brelse(bh);
2188 return retval;
2189 }
2190
2191 static int ext4_unlink(struct inode *dir, struct dentry *dentry)
2192 {
2193 int retval;
2194 struct inode *inode;
2195 struct buffer_head *bh;
2196 struct ext4_dir_entry_2 *de;
2197 handle_t *handle;
2198
2199 trace_ext4_unlink_enter(dir, dentry);
2200 /* Initialize quotas before so that eventual writes go
2201 * in separate transaction */
2202 dquot_initialize(dir);
2203 dquot_initialize(dentry->d_inode);
2204
2205 handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb));
2206 if (IS_ERR(handle))
2207 return PTR_ERR(handle);
2208
2209 if (IS_DIRSYNC(dir))
2210 ext4_handle_sync(handle);
2211
2212 retval = -ENOENT;
2213 bh = ext4_find_entry(dir, &dentry->d_name, &de);
2214 if (!bh)
2215 goto end_unlink;
2216
2217 inode = dentry->d_inode;
2218
2219 retval = -EIO;
2220 if (le32_to_cpu(de->inode) != inode->i_ino)
2221 goto end_unlink;
2222
2223 if (!inode->i_nlink) {
2224 ext4_warning(inode->i_sb,
2225 "Deleting nonexistent file (%lu), %d",
2226 inode->i_ino, inode->i_nlink);
2227 inode->i_nlink = 1;
2228 }
2229 retval = ext4_delete_entry(handle, dir, de, bh);
2230 if (retval)
2231 goto end_unlink;
2232 dir->i_ctime = dir->i_mtime = ext4_current_time(dir);
2233 ext4_update_dx_flag(dir);
2234 ext4_mark_inode_dirty(handle, dir);
2235 drop_nlink(inode);
2236 if (!inode->i_nlink)
2237 ext4_orphan_add(handle, inode);
2238 inode->i_ctime = ext4_current_time(inode);
2239 ext4_mark_inode_dirty(handle, inode);
2240 retval = 0;
2241
2242 end_unlink:
2243 ext4_journal_stop(handle);
2244 brelse(bh);
2245 trace_ext4_unlink_exit(dentry, retval);
2246 return retval;
2247 }
2248
2249 static int ext4_symlink(struct inode *dir,
2250 struct dentry *dentry, const char *symname)
2251 {
2252 handle_t *handle;
2253 struct inode *inode;
2254 int l, err, retries = 0;
2255 int credits;
2256
2257 l = strlen(symname)+1;
2258 if (l > dir->i_sb->s_blocksize)
2259 return -ENAMETOOLONG;
2260
2261 dquot_initialize(dir);
2262
2263 if (l > EXT4_N_BLOCKS * 4) {
2264 /*
2265 * For non-fast symlinks, we just allocate inode and put it on
2266 * orphan list in the first transaction => we need bitmap,
2267 * group descriptor, sb, inode block, quota blocks.
2268 */
2269 credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb);
2270 } else {
2271 /*
2272 * Fast symlink. We have to add entry to directory
2273 * (EXT4_DATA_TRANS_BLOCKS + EXT4_INDEX_EXTRA_TRANS_BLOCKS),
2274 * allocate new inode (bitmap, group descriptor, inode block,
2275 * quota blocks, sb is already counted in previous macros).
2276 */
2277 credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2278 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
2279 EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb);
2280 }
2281 retry:
2282 handle = ext4_journal_start(dir, credits);
2283 if (IS_ERR(handle))
2284 return PTR_ERR(handle);
2285
2286 if (IS_DIRSYNC(dir))
2287 ext4_handle_sync(handle);
2288
2289 inode = ext4_new_inode(handle, dir, S_IFLNK|S_IRWXUGO,
2290 &dentry->d_name, 0);
2291 err = PTR_ERR(inode);
2292 if (IS_ERR(inode))
2293 goto out_stop;
2294
2295 if (l > EXT4_N_BLOCKS * 4) {
2296 inode->i_op = &ext4_symlink_inode_operations;
2297 ext4_set_aops(inode);
2298 /*
2299 * We cannot call page_symlink() with transaction started
2300 * because it calls into ext4_write_begin() which can wait
2301 * for transaction commit if we are running out of space
2302 * and thus we deadlock. So we have to stop transaction now
2303 * and restart it when symlink contents is written.
2304 *
2305 * To keep fs consistent in case of crash, we have to put inode
2306 * to orphan list in the mean time.
2307 */
2308 drop_nlink(inode);
2309 err = ext4_orphan_add(handle, inode);
2310 ext4_journal_stop(handle);
2311 if (err)
2312 goto err_drop_inode;
2313 err = __page_symlink(inode, symname, l, 1);
2314 if (err)
2315 goto err_drop_inode;
2316 /*
2317 * Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS
2318 * + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified
2319 */
2320 handle = ext4_journal_start(dir,
2321 EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2322 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1);
2323 if (IS_ERR(handle)) {
2324 err = PTR_ERR(handle);
2325 goto err_drop_inode;
2326 }
2327 inc_nlink(inode);
2328 err = ext4_orphan_del(handle, inode);
2329 if (err) {
2330 ext4_journal_stop(handle);
2331 clear_nlink(inode);
2332 goto err_drop_inode;
2333 }
2334 } else {
2335 /* clear the extent format for fast symlink */
2336 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
2337 inode->i_op = &ext4_fast_symlink_inode_operations;
2338 memcpy((char *)&EXT4_I(inode)->i_data, symname, l);
2339 inode->i_size = l-1;
2340 }
2341 EXT4_I(inode)->i_disksize = inode->i_size;
2342 err = ext4_add_nondir(handle, dentry, inode);
2343 out_stop:
2344 ext4_journal_stop(handle);
2345 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2346 goto retry;
2347 return err;
2348 err_drop_inode:
2349 unlock_new_inode(inode);
2350 iput(inode);
2351 return err;
2352 }
2353
2354 static int ext4_link(struct dentry *old_dentry,
2355 struct inode *dir, struct dentry *dentry)
2356 {
2357 handle_t *handle;
2358 struct inode *inode = old_dentry->d_inode;
2359 int err, retries = 0;
2360
2361 if (inode->i_nlink >= EXT4_LINK_MAX)
2362 return -EMLINK;
2363
2364 dquot_initialize(dir);
2365
2366 retry:
2367 handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2368 EXT4_INDEX_EXTRA_TRANS_BLOCKS);
2369 if (IS_ERR(handle))
2370 return PTR_ERR(handle);
2371
2372 if (IS_DIRSYNC(dir))
2373 ext4_handle_sync(handle);
2374
2375 inode->i_ctime = ext4_current_time(inode);
2376 ext4_inc_count(handle, inode);
2377 ihold(inode);
2378
2379 err = ext4_add_entry(handle, dentry, inode);
2380 if (!err) {
2381 ext4_mark_inode_dirty(handle, inode);
2382 d_instantiate(dentry, inode);
2383 } else {
2384 drop_nlink(inode);
2385 iput(inode);
2386 }
2387 ext4_journal_stop(handle);
2388 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2389 goto retry;
2390 return err;
2391 }
2392
2393 #define PARENT_INO(buffer, size) \
2394 (ext4_next_entry((struct ext4_dir_entry_2 *)(buffer), size)->inode)
2395
2396 /*
2397 * Anybody can rename anything with this: the permission checks are left to the
2398 * higher-level routines.
2399 */
2400 static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
2401 struct inode *new_dir, struct dentry *new_dentry)
2402 {
2403 handle_t *handle;
2404 struct inode *old_inode, *new_inode;
2405 struct buffer_head *old_bh, *new_bh, *dir_bh;
2406 struct ext4_dir_entry_2 *old_de, *new_de;
2407 int retval, force_da_alloc = 0;
2408
2409 dquot_initialize(old_dir);
2410 dquot_initialize(new_dir);
2411
2412 old_bh = new_bh = dir_bh = NULL;
2413
2414 /* Initialize quotas before so that eventual writes go
2415 * in separate transaction */
2416 if (new_dentry->d_inode)
2417 dquot_initialize(new_dentry->d_inode);
2418 handle = ext4_journal_start(old_dir, 2 *
2419 EXT4_DATA_TRANS_BLOCKS(old_dir->i_sb) +
2420 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
2421 if (IS_ERR(handle))
2422 return PTR_ERR(handle);
2423
2424 if (IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir))
2425 ext4_handle_sync(handle);
2426
2427 old_bh = ext4_find_entry(old_dir, &old_dentry->d_name, &old_de);
2428 /*
2429 * Check for inode number is _not_ due to possible IO errors.
2430 * We might rmdir the source, keep it as pwd of some process
2431 * and merrily kill the link to whatever was created under the
2432 * same name. Goodbye sticky bit ;-<
2433 */
2434 old_inode = old_dentry->d_inode;
2435 retval = -ENOENT;
2436 if (!old_bh || le32_to_cpu(old_de->inode) != old_inode->i_ino)
2437 goto end_rename;
2438
2439 new_inode = new_dentry->d_inode;
2440 new_bh = ext4_find_entry(new_dir, &new_dentry->d_name, &new_de);
2441 if (new_bh) {
2442 if (!new_inode) {
2443 brelse(new_bh);
2444 new_bh = NULL;
2445 }
2446 }
2447 if (S_ISDIR(old_inode->i_mode)) {
2448 if (new_inode) {
2449 retval = -ENOTEMPTY;
2450 if (!empty_dir(new_inode))
2451 goto end_rename;
2452 }
2453 retval = -EIO;
2454 dir_bh = ext4_bread(handle, old_inode, 0, 0, &retval);
2455 if (!dir_bh)
2456 goto end_rename;
2457 if (le32_to_cpu(PARENT_INO(dir_bh->b_data,
2458 old_dir->i_sb->s_blocksize)) != old_dir->i_ino)
2459 goto end_rename;
2460 retval = -EMLINK;
2461 if (!new_inode && new_dir != old_dir &&
2462 EXT4_DIR_LINK_MAX(new_dir))
2463 goto end_rename;
2464 BUFFER_TRACE(dir_bh, "get_write_access");
2465 retval = ext4_journal_get_write_access(handle, dir_bh);
2466 if (retval)
2467 goto end_rename;
2468 }
2469 if (!new_bh) {
2470 retval = ext4_add_entry(handle, new_dentry, old_inode);
2471 if (retval)
2472 goto end_rename;
2473 } else {
2474 BUFFER_TRACE(new_bh, "get write access");
2475 retval = ext4_journal_get_write_access(handle, new_bh);
2476 if (retval)
2477 goto end_rename;
2478 new_de->inode = cpu_to_le32(old_inode->i_ino);
2479 if (EXT4_HAS_INCOMPAT_FEATURE(new_dir->i_sb,
2480 EXT4_FEATURE_INCOMPAT_FILETYPE))
2481 new_de->file_type = old_de->file_type;
2482 new_dir->i_version++;
2483 new_dir->i_ctime = new_dir->i_mtime =
2484 ext4_current_time(new_dir);
2485 ext4_mark_inode_dirty(handle, new_dir);
2486 BUFFER_TRACE(new_bh, "call ext4_handle_dirty_metadata");
2487 retval = ext4_handle_dirty_metadata(handle, new_dir, new_bh);
2488 if (unlikely(retval)) {
2489 ext4_std_error(new_dir->i_sb, retval);
2490 goto end_rename;
2491 }
2492 brelse(new_bh);
2493 new_bh = NULL;
2494 }
2495
2496 /*
2497 * Like most other Unix systems, set the ctime for inodes on a
2498 * rename.
2499 */
2500 old_inode->i_ctime = ext4_current_time(old_inode);
2501 ext4_mark_inode_dirty(handle, old_inode);
2502
2503 /*
2504 * ok, that's it
2505 */
2506 if (le32_to_cpu(old_de->inode) != old_inode->i_ino ||
2507 old_de->name_len != old_dentry->d_name.len ||
2508 strncmp(old_de->name, old_dentry->d_name.name, old_de->name_len) ||
2509 (retval = ext4_delete_entry(handle, old_dir,
2510 old_de, old_bh)) == -ENOENT) {
2511 /* old_de could have moved from under us during htree split, so
2512 * make sure that we are deleting the right entry. We might
2513 * also be pointing to a stale entry in the unused part of
2514 * old_bh so just checking inum and the name isn't enough. */
2515 struct buffer_head *old_bh2;
2516 struct ext4_dir_entry_2 *old_de2;
2517
2518 old_bh2 = ext4_find_entry(old_dir, &old_dentry->d_name, &old_de2);
2519 if (old_bh2) {
2520 retval = ext4_delete_entry(handle, old_dir,
2521 old_de2, old_bh2);
2522 brelse(old_bh2);
2523 }
2524 }
2525 if (retval) {
2526 ext4_warning(old_dir->i_sb,
2527 "Deleting old file (%lu), %d, error=%d",
2528 old_dir->i_ino, old_dir->i_nlink, retval);
2529 }
2530
2531 if (new_inode) {
2532 ext4_dec_count(handle, new_inode);
2533 new_inode->i_ctime = ext4_current_time(new_inode);
2534 }
2535 old_dir->i_ctime = old_dir->i_mtime = ext4_current_time(old_dir);
2536 ext4_update_dx_flag(old_dir);
2537 if (dir_bh) {
2538 PARENT_INO(dir_bh->b_data, new_dir->i_sb->s_blocksize) =
2539 cpu_to_le32(new_dir->i_ino);
2540 BUFFER_TRACE(dir_bh, "call ext4_handle_dirty_metadata");
2541 retval = ext4_handle_dirty_metadata(handle, old_dir, dir_bh);
2542 if (retval) {
2543 ext4_std_error(old_dir->i_sb, retval);
2544 goto end_rename;
2545 }
2546 ext4_dec_count(handle, old_dir);
2547 if (new_inode) {
2548 /* checked empty_dir above, can't have another parent,
2549 * ext4_dec_count() won't work for many-linked dirs */
2550 new_inode->i_nlink = 0;
2551 } else {
2552 ext4_inc_count(handle, new_dir);
2553 ext4_update_dx_flag(new_dir);
2554 ext4_mark_inode_dirty(handle, new_dir);
2555 }
2556 }
2557 ext4_mark_inode_dirty(handle, old_dir);
2558 if (new_inode) {
2559 ext4_mark_inode_dirty(handle, new_inode);
2560 if (!new_inode->i_nlink)
2561 ext4_orphan_add(handle, new_inode);
2562 if (!test_opt(new_dir->i_sb, NO_AUTO_DA_ALLOC))
2563 force_da_alloc = 1;
2564 }
2565 retval = 0;
2566
2567 end_rename:
2568 brelse(dir_bh);
2569 brelse(old_bh);
2570 brelse(new_bh);
2571 ext4_journal_stop(handle);
2572 if (retval == 0 && force_da_alloc)
2573 ext4_alloc_da_blocks(old_inode);
2574 return retval;
2575 }
2576
2577 /*
2578 * directories can handle most operations...
2579 */
2580 const struct inode_operations ext4_dir_inode_operations = {
2581 .create = ext4_create,
2582 .lookup = ext4_lookup,
2583 .link = ext4_link,
2584 .unlink = ext4_unlink,
2585 .symlink = ext4_symlink,
2586 .mkdir = ext4_mkdir,
2587 .rmdir = ext4_rmdir,
2588 .mknod = ext4_mknod,
2589 .rename = ext4_rename,
2590 .setattr = ext4_setattr,
2591 #ifdef CONFIG_EXT4_FS_XATTR
2592 .setxattr = generic_setxattr,
2593 .getxattr = generic_getxattr,
2594 .listxattr = ext4_listxattr,
2595 .removexattr = generic_removexattr,
2596 #endif
2597 .check_acl = ext4_check_acl,
2598 .fiemap = ext4_fiemap,
2599 };
2600
2601 const struct inode_operations ext4_special_inode_operations = {
2602 .setattr = ext4_setattr,
2603 #ifdef CONFIG_EXT4_FS_XATTR
2604 .setxattr = generic_setxattr,
2605 .getxattr = generic_getxattr,
2606 .listxattr = ext4_listxattr,
2607 .removexattr = generic_removexattr,
2608 #endif
2609 .check_acl = ext4_check_acl,
2610 };
linux-next