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1/*
2 * linux/fs/ext4/namei.c
3 *
4 * Copyright (C) 1992, 1993, 1994, 1995
5 * Remy Card (card@masi.ibp.fr)
6 * Laboratoire MASI - Institut Blaise Pascal
7 * Universite Pierre et Marie Curie (Paris VI)
8 *
9 * from
10 *
11 * linux/fs/minix/namei.c
12 *
13 * Copyright (C) 1991, 1992 Linus Torvalds
14 *
15 * Big-endian to little-endian byte-swapping/bitmaps by
16 * David S. Miller (davem@caip.rutgers.edu), 1995
17 * Directory entry file type support and forward compatibility hooks
18 * for B-tree directories by Theodore Ts'o (tytso@mit.edu), 1998
19 * Hash Tree Directory indexing (c)
20 * Daniel Phillips, 2001
21 * Hash Tree Directory indexing porting
22 * Christopher Li, 2002
23 * Hash Tree Directory indexing cleanup
24 * Theodore Ts'o, 2002
25 */
26
27#include <linux/fs.h>
28#include <linux/pagemap.h>
29#include <linux/jbd2.h>
30#include <linux/time.h>
31#include <linux/fcntl.h>
32#include <linux/stat.h>
33#include <linux/string.h>
34#include <linux/quotaops.h>
35#include <linux/buffer_head.h>
36#include <linux/bio.h>
37#include "ext4.h"
38#include "ext4_jbd2.h"
39
40#include "xattr.h"
41#include "acl.h"
42
43#include <trace/events/ext4.h>
44/*
45 * define how far ahead to read directories while searching them.
46 */
47#define NAMEI_RA_CHUNKS 2
48#define NAMEI_RA_BLOCKS 4
49#define NAMEI_RA_SIZE (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS)
50#define NAMEI_RA_INDEX(c,b) (((c) * NAMEI_RA_BLOCKS) + (b))
51
52static struct buffer_head *ext4_append(handle_t *handle,
53 struct inode *inode,
54 ext4_lblk_t *block, int *err)
55{
56 struct buffer_head *bh;
57
58 *block = inode->i_size >> inode->i_sb->s_blocksize_bits;
59
60 bh = ext4_bread(handle, inode, *block, 1, err);
61 if (bh) {
62 inode->i_size += inode->i_sb->s_blocksize;
63 EXT4_I(inode)->i_disksize = inode->i_size;
64 *err = ext4_journal_get_write_access(handle, bh);
65 if (*err) {
66 brelse(bh);
67 bh = NULL;
68 }
69 }
70 return bh;
71}
72
73#ifndef assert
74#define assert(test) J_ASSERT(test)
75#endif
76
77#ifdef DX_DEBUG
78#define dxtrace(command) command
79#else
80#define dxtrace(command)
81#endif
82
83struct fake_dirent
84{
85 __le32 inode;
86 __le16 rec_len;
87 u8 name_len;
88 u8 file_type;
89};
90
91struct dx_countlimit
92{
93 __le16 limit;
94 __le16 count;
95};
96
97struct dx_entry
98{
99 __le32 hash;
100 __le32 block;
101};
102
103/*
104 * dx_root_info is laid out so that if it should somehow get overlaid by a
105 * dirent the two low bits of the hash version will be zero. Therefore, the
106 * hash version mod 4 should never be 0. Sincerely, the paranoia department.
107 */
108
109struct dx_root
110{
111 struct fake_dirent dot;
112 char dot_name[4];
113 struct fake_dirent dotdot;
114 char dotdot_name[4];
115 struct dx_root_info
116 {
117 __le32 reserved_zero;
118 u8 hash_version;
119 u8 info_length; /* 8 */
120 u8 indirect_levels;
121 u8 unused_flags;
122 }
123 info;
124 struct dx_entry entries[0];
125};
126
127struct dx_node
128{
129 struct fake_dirent fake;
130 struct dx_entry entries[0];
131};
132
133
134struct dx_frame
135{
136 struct buffer_head *bh;
137 struct dx_entry *entries;
138 struct dx_entry *at;
139};
140
141struct dx_map_entry
142{
143 u32 hash;
144 u16 offs;
145 u16 size;
146};
147
148static inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
149static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
150static inline unsigned dx_get_hash(struct dx_entry *entry);
151static void dx_set_hash(struct dx_entry *entry, unsigned value);
152static unsigned dx_get_count(struct dx_entry *entries);
153static unsigned dx_get_limit(struct dx_entry *entries);
154static void dx_set_count(struct dx_entry *entries, unsigned value);
155static void dx_set_limit(struct dx_entry *entries, unsigned value);
156static unsigned dx_root_limit(struct inode *dir, unsigned infosize);
157static unsigned dx_node_limit(struct inode *dir);
158static struct dx_frame *dx_probe(const struct qstr *d_name,
159 struct inode *dir,
160 struct dx_hash_info *hinfo,
161 struct dx_frame *frame,
162 int *err);
163static void dx_release(struct dx_frame *frames);
164static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize,
165 struct dx_hash_info *hinfo, struct dx_map_entry map[]);
166static void dx_sort_map(struct dx_map_entry *map, unsigned count);
167static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to,
168 struct dx_map_entry *offsets, int count, unsigned blocksize);
169static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize);
170static void dx_insert_block(struct dx_frame *frame,
171 u32 hash, ext4_lblk_t block);
172static int ext4_htree_next_block(struct inode *dir, __u32 hash,
173 struct dx_frame *frame,
174 struct dx_frame *frames,
175 __u32 *start_hash);
176static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
177 const struct qstr *d_name,
178 struct ext4_dir_entry_2 **res_dir,
179 int *err);
180static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
181 struct inode *inode);
182
183/*
184 * p is at least 6 bytes before the end of page
185 */
186static inline struct ext4_dir_entry_2 *
187ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
188{
189 return (struct ext4_dir_entry_2 *)((char *)p +
190 ext4_rec_len_from_disk(p->rec_len, blocksize));
191}
192
193/*
194 * Future: use high four bits of block for coalesce-on-delete flags
195 * Mask them off for now.
196 */
197
198static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
199{
200 return le32_to_cpu(entry->block) & 0x00ffffff;
201}
202
203static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
204{
205 entry->block = cpu_to_le32(value);
206}
207
208static inline unsigned dx_get_hash(struct dx_entry *entry)
209{
210 return le32_to_cpu(entry->hash);
211}
212
213static inline void dx_set_hash(struct dx_entry *entry, unsigned value)
214{
215 entry->hash = cpu_to_le32(value);
216}
217
218static inline unsigned dx_get_count(struct dx_entry *entries)
219{
220 return le16_to_cpu(((struct dx_countlimit *) entries)->count);
221}
222
223static inline unsigned dx_get_limit(struct dx_entry *entries)
224{
225 return le16_to_cpu(((struct dx_countlimit *) entries)->limit);
226}
227
228static inline void dx_set_count(struct dx_entry *entries, unsigned value)
229{
230 ((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
231}
232
233static inline void dx_set_limit(struct dx_entry *entries, unsigned value)
234{
235 ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
236}
237
238static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
239{
240 unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
241 EXT4_DIR_REC_LEN(2) - infosize;
242 return entry_space / sizeof(struct dx_entry);
243}
244
245static inline unsigned dx_node_limit(struct inode *dir)
246{
247 unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);
248 return entry_space / sizeof(struct dx_entry);
249}
250
251/*
252 * Debug
253 */
254#ifdef DX_DEBUG
255static void dx_show_index(char * label, struct dx_entry *entries)
256{
257 int i, n = dx_get_count (entries);
258 printk(KERN_DEBUG "%s index ", label);
259 for (i = 0; i < n; i++) {
260 printk("%x->%lu ", i ? dx_get_hash(entries + i) :
261 0, (unsigned long)dx_get_block(entries + i));
262 }
263 printk("\n");
264}
265
266struct stats
267{
268 unsigned names;
269 unsigned space;
270 unsigned bcount;
271};
272
273static struct stats dx_show_leaf(struct dx_hash_info *hinfo, struct ext4_dir_entry_2 *de,
274 int size, int show_names)
275{
276 unsigned names = 0, space = 0;
277 char *base = (char *) de;
278 struct dx_hash_info h = *hinfo;
279
280 printk("names: ");
281 while ((char *) de < base + size)
282 {
283 if (de->inode)
284 {
285 if (show_names)
286 {
287 int len = de->name_len;
288 char *name = de->name;
289 while (len--) printk("%c", *name++);
290 ext4fs_dirhash(de->name, de->name_len, &h);
291 printk(":%x.%u ", h.hash,
292 (unsigned) ((char *) de - base));
293 }
294 space += EXT4_DIR_REC_LEN(de->name_len);
295 names++;
296 }
297 de = ext4_next_entry(de, size);
298 }
299 printk("(%i)\n", names);
300 return (struct stats) { names, space, 1 };
301}
302
303struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
304 struct dx_entry *entries, int levels)
305{
306 unsigned blocksize = dir->i_sb->s_blocksize;
307 unsigned count = dx_get_count(entries), names = 0, space = 0, i;
308 unsigned bcount = 0;
309 struct buffer_head *bh;
310 int err;
311 printk("%i indexed blocks...\n", count);
312 for (i = 0; i < count; i++, entries++)
313 {
314 ext4_lblk_t block = dx_get_block(entries);
315 ext4_lblk_t hash = i ? dx_get_hash(entries): 0;
316 u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
317 struct stats stats;
318 printk("%s%3u:%03u hash %8x/%8x ",levels?"":" ", i, block, hash, range);
319 if (!(bh = ext4_bread (NULL,dir, block, 0,&err))) continue;
320 stats = levels?
321 dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
322 dx_show_leaf(hinfo, (struct ext4_dir_entry_2 *) bh->b_data, blocksize, 0);
323 names += stats.names;
324 space += stats.space;
325 bcount += stats.bcount;
326 brelse(bh);
327 }
328 if (bcount)
329 printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n",
330 levels ? "" : " ", names, space/bcount,
331 (space/bcount)*100/blocksize);
332 return (struct stats) { names, space, bcount};
333}
334#endif /* DX_DEBUG */
335
336/*
337 * Probe for a directory leaf block to search.
338 *
339 * dx_probe can return ERR_BAD_DX_DIR, which means there was a format
340 * error in the directory index, and the caller should fall back to
341 * searching the directory normally. The callers of dx_probe **MUST**
342 * check for this error code, and make sure it never gets reflected
343 * back to userspace.
344 */
345static struct dx_frame *
346dx_probe(const struct qstr *d_name, struct inode *dir,
347 struct dx_hash_info *hinfo, struct dx_frame *frame_in, int *err)
348{
349 unsigned count, indirect;
350 struct dx_entry *at, *entries, *p, *q, *m;
351 struct dx_root *root;
352 struct buffer_head *bh;
353 struct dx_frame *frame = frame_in;
354 u32 hash;
355
356 frame->bh = NULL;
357 if (!(bh = ext4_bread (NULL,dir, 0, 0, err)))
358 goto fail;
359 root = (struct dx_root *) bh->b_data;
360 if (root->info.hash_version != DX_HASH_TEA &&
361 root->info.hash_version != DX_HASH_HALF_MD4 &&
362 root->info.hash_version != DX_HASH_LEGACY) {
363 ext4_warning(dir->i_sb, "Unrecognised inode hash code %d",
364 root->info.hash_version);
365 brelse(bh);
366 *err = ERR_BAD_DX_DIR;
367 goto fail;
368 }
369 hinfo->hash_version = root->info.hash_version;
370 if (hinfo->hash_version <= DX_HASH_TEA)
371 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
372 hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
373 if (d_name)
374 ext4fs_dirhash(d_name->name, d_name->len, hinfo);
375 hash = hinfo->hash;
376
377 if (root->info.unused_flags & 1) {
378 ext4_warning(dir->i_sb, "Unimplemented inode hash flags: %#06x",
379 root->info.unused_flags);
380 brelse(bh);
381 *err = ERR_BAD_DX_DIR;
382 goto fail;
383 }
384
385 if ((indirect = root->info.indirect_levels) > 1) {
386 ext4_warning(dir->i_sb, "Unimplemented inode hash depth: %#06x",
387 root->info.indirect_levels);
388 brelse(bh);
389 *err = ERR_BAD_DX_DIR;
390 goto fail;
391 }
392
393 entries = (struct dx_entry *) (((char *)&root->info) +
394 root->info.info_length);
395
396 if (dx_get_limit(entries) != dx_root_limit(dir,
397 root->info.info_length)) {
398 ext4_warning(dir->i_sb, "dx entry: limit != root limit");
399 brelse(bh);
400 *err = ERR_BAD_DX_DIR;
401 goto fail;
402 }
403
404 dxtrace(printk("Look up %x", hash));
405 while (1)
406 {
407 count = dx_get_count(entries);
408 if (!count || count > dx_get_limit(entries)) {
409 ext4_warning(dir->i_sb,
410 "dx entry: no count or count > limit");
411 brelse(bh);
412 *err = ERR_BAD_DX_DIR;
413 goto fail2;
414 }
415
416 p = entries + 1;
417 q = entries + count - 1;
418 while (p <= q)
419 {
420 m = p + (q - p)/2;
421 dxtrace(printk("."));
422 if (dx_get_hash(m) > hash)
423 q = m - 1;
424 else
425 p = m + 1;
426 }
427
428 if (0) // linear search cross check
429 {
430 unsigned n = count - 1;
431 at = entries;
432 while (n--)
433 {
434 dxtrace(printk(","));
435 if (dx_get_hash(++at) > hash)
436 {
437 at--;
438 break;
439 }
440 }
441 assert (at == p - 1);
442 }
443
444 at = p - 1;
445 dxtrace(printk(" %x->%u\n", at == entries? 0: dx_get_hash(at), dx_get_block(at)));
446 frame->bh = bh;
447 frame->entries = entries;
448 frame->at = at;
449 if (!indirect--) return frame;
450 if (!(bh = ext4_bread (NULL,dir, dx_get_block(at), 0, err)))
451 goto fail2;
452 at = entries = ((struct dx_node *) bh->b_data)->entries;
453 if (dx_get_limit(entries) != dx_node_limit (dir)) {
454 ext4_warning(dir->i_sb,
455 "dx entry: limit != node limit");
456 brelse(bh);
457 *err = ERR_BAD_DX_DIR;
458 goto fail2;
459 }
460 frame++;
461 frame->bh = NULL;
462 }
463fail2:
464 while (frame >= frame_in) {
465 brelse(frame->bh);
466 frame--;
467 }
468fail:
469 if (*err == ERR_BAD_DX_DIR)
470 ext4_warning(dir->i_sb,
471 "Corrupt dir inode %ld, running e2fsck is "
472 "recommended.", dir->i_ino);
473 return NULL;
474}
475
476static void dx_release (struct dx_frame *frames)
477{
478 if (frames[0].bh == NULL)
479 return;
480
481 if (((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels)
482 brelse(frames[1].bh);
483 brelse(frames[0].bh);
484}
485
486/*
487 * This function increments the frame pointer to search the next leaf
488 * block, and reads in the necessary intervening nodes if the search
489 * should be necessary. Whether or not the search is necessary is
490 * controlled by the hash parameter. If the hash value is even, then
491 * the search is only continued if the next block starts with that
492 * hash value. This is used if we are searching for a specific file.
493 *
494 * If the hash value is HASH_NB_ALWAYS, then always go to the next block.
495 *
496 * This function returns 1 if the caller should continue to search,
497 * or 0 if it should not. If there is an error reading one of the
498 * index blocks, it will a negative error code.
499 *
500 * If start_hash is non-null, it will be filled in with the starting
501 * hash of the next page.
502 */
503static int ext4_htree_next_block(struct inode *dir, __u32 hash,
504 struct dx_frame *frame,
505 struct dx_frame *frames,
506 __u32 *start_hash)
507{
508 struct dx_frame *p;
509 struct buffer_head *bh;
510 int err, num_frames = 0;
511 __u32 bhash;
512
513 p = frame;
514 /*
515 * Find the next leaf page by incrementing the frame pointer.
516 * If we run out of entries in the interior node, loop around and
517 * increment pointer in the parent node. When we break out of
518 * this loop, num_frames indicates the number of interior
519 * nodes need to be read.
520 */
521 while (1) {
522 if (++(p->at) < p->entries + dx_get_count(p->entries))
523 break;
524 if (p == frames)
525 return 0;
526 num_frames++;
527 p--;
528 }
529
530 /*
531 * If the hash is 1, then continue only if the next page has a
532 * continuation hash of any value. This is used for readdir
533 * handling. Otherwise, check to see if the hash matches the
534 * desired contiuation hash. If it doesn't, return since
535 * there's no point to read in the successive index pages.
536 */
537 bhash = dx_get_hash(p->at);
538 if (start_hash)
539 *start_hash = bhash;
540 if ((hash & 1) == 0) {
541 if ((bhash & ~1) != hash)
542 return 0;
543 }
544 /*
545 * If the hash is HASH_NB_ALWAYS, we always go to the next
546 * block so no check is necessary
547 */
548 while (num_frames--) {
549 if (!(bh = ext4_bread(NULL, dir, dx_get_block(p->at),
550 0, &err)))
551 return err; /* Failure */
552 p++;
553 brelse(p->bh);
554 p->bh = bh;
555 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
556 }
557 return 1;
558}
559
560
561/*
562 * This function fills a red-black tree with information from a
563 * directory block. It returns the number directory entries loaded
564 * into the tree. If there is an error it is returned in err.
565 */
566static int htree_dirblock_to_tree(struct file *dir_file,
567 struct inode *dir, ext4_lblk_t block,
568 struct dx_hash_info *hinfo,
569 __u32 start_hash, __u32 start_minor_hash)
570{
571 struct buffer_head *bh;
572 struct ext4_dir_entry_2 *de, *top;
573 int err, count = 0;
574
575 dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
576 (unsigned long)block));
577 if (!(bh = ext4_bread (NULL, dir, block, 0, &err)))
578 return err;
579
580 de = (struct ext4_dir_entry_2 *) bh->b_data;
581 top = (struct ext4_dir_entry_2 *) ((char *) de +
582 dir->i_sb->s_blocksize -
583 EXT4_DIR_REC_LEN(0));
584 for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) {
585 if (ext4_check_dir_entry(dir, NULL, de, bh,
586 (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
587 + ((char *)de - bh->b_data))) {
588 /* On error, skip the f_pos to the next block. */
589 dir_file->f_pos = (dir_file->f_pos |
590 (dir->i_sb->s_blocksize - 1)) + 1;
591 brelse(bh);
592 return count;
593 }
594 ext4fs_dirhash(de->name, de->name_len, hinfo);
595 if ((hinfo->hash < start_hash) ||
596 ((hinfo->hash == start_hash) &&
597 (hinfo->minor_hash < start_minor_hash)))
598 continue;
599 if (de->inode == 0)
600 continue;
601 if ((err = ext4_htree_store_dirent(dir_file,
602 hinfo->hash, hinfo->minor_hash, de)) != 0) {
603 brelse(bh);
604 return err;
605 }
606 count++;
607 }
608 brelse(bh);
609 return count;
610}
611
612
613/*
614 * This function fills a red-black tree with information from a
615 * directory. We start scanning the directory in hash order, starting
616 * at start_hash and start_minor_hash.
617 *
618 * This function returns the number of entries inserted into the tree,
619 * or a negative error code.
620 */
621int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
622 __u32 start_minor_hash, __u32 *next_hash)
623{
624 struct dx_hash_info hinfo;
625 struct ext4_dir_entry_2 *de;
626 struct dx_frame frames[2], *frame;
627 struct inode *dir;
628 ext4_lblk_t block;
629 int count = 0;
630 int ret, err;
631 __u32 hashval;
632
633 dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
634 start_hash, start_minor_hash));
635 dir = dir_file->f_path.dentry->d_inode;
636 if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) {
637 hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
638 if (hinfo.hash_version <= DX_HASH_TEA)
639 hinfo.hash_version +=
640 EXT4_SB(dir->i_sb)->s_hash_unsigned;
641 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
642 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
643 start_hash, start_minor_hash);
644 *next_hash = ~0;
645 return count;
646 }
647 hinfo.hash = start_hash;
648 hinfo.minor_hash = 0;
649 frame = dx_probe(NULL, dir, &hinfo, frames, &err);
650 if (!frame)
651 return err;
652
653 /* Add '.' and '..' from the htree header */
654 if (!start_hash && !start_minor_hash) {
655 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
656 if ((err = ext4_htree_store_dirent(dir_file, 0, 0, de)) != 0)
657 goto errout;
658 count++;
659 }
660 if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
661 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
662 de = ext4_next_entry(de, dir->i_sb->s_blocksize);
663 if ((err = ext4_htree_store_dirent(dir_file, 2, 0, de)) != 0)
664 goto errout;
665 count++;
666 }
667
668 while (1) {
669 block = dx_get_block(frame->at);
670 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
671 start_hash, start_minor_hash);
672 if (ret < 0) {
673 err = ret;
674 goto errout;
675 }
676 count += ret;
677 hashval = ~0;
678 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
679 frame, frames, &hashval);
680 *next_hash = hashval;
681 if (ret < 0) {
682 err = ret;
683 goto errout;
684 }
685 /*
686 * Stop if: (a) there are no more entries, or
687 * (b) we have inserted at least one entry and the
688 * next hash value is not a continuation
689 */
690 if ((ret == 0) ||
691 (count && ((hashval & 1) == 0)))
692 break;
693 }
694 dx_release(frames);
695 dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, "
696 "next hash: %x\n", count, *next_hash));
697 return count;
698errout:
699 dx_release(frames);
700 return (err);
701}
702
703
704/*
705 * Directory block splitting, compacting
706 */
707
708/*
709 * Create map of hash values, offsets, and sizes, stored at end of block.
710 * Returns number of entries mapped.
711 */
712static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize,
713 struct dx_hash_info *hinfo,
714 struct dx_map_entry *map_tail)
715{
716 int count = 0;
717 char *base = (char *) de;
718 struct dx_hash_info h = *hinfo;
719
720 while ((char *) de < base + blocksize) {
721 if (de->name_len && de->inode) {
722 ext4fs_dirhash(de->name, de->name_len, &h);
723 map_tail--;
724 map_tail->hash = h.hash;
725 map_tail->offs = ((char *) de - base)>>2;
726 map_tail->size = le16_to_cpu(de->rec_len);
727 count++;
728 cond_resched();
729 }
730 /* XXX: do we need to check rec_len == 0 case? -Chris */
731 de = ext4_next_entry(de, blocksize);
732 }
733 return count;
734}
735
736/* Sort map by hash value */
737static void dx_sort_map (struct dx_map_entry *map, unsigned count)
738{
739 struct dx_map_entry *p, *q, *top = map + count - 1;
740 int more;
741 /* Combsort until bubble sort doesn't suck */
742 while (count > 2) {
743 count = count*10/13;
744 if (count - 9 < 2) /* 9, 10 -> 11 */
745 count = 11;
746 for (p = top, q = p - count; q >= map; p--, q--)
747 if (p->hash < q->hash)
748 swap(*p, *q);
749 }
750 /* Garden variety bubble sort */
751 do {
752 more = 0;
753 q = top;
754 while (q-- > map) {
755 if (q[1].hash >= q[0].hash)
756 continue;
757 swap(*(q+1), *q);
758 more = 1;
759 }
760 } while(more);
761}
762
763static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
764{
765 struct dx_entry *entries = frame->entries;
766 struct dx_entry *old = frame->at, *new = old + 1;
767 int count = dx_get_count(entries);
768
769 assert(count < dx_get_limit(entries));
770 assert(old < entries + count);
771 memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
772 dx_set_hash(new, hash);
773 dx_set_block(new, block);
774 dx_set_count(entries, count + 1);
775}
776
777static void ext4_update_dx_flag(struct inode *inode)
778{
779 if (!EXT4_HAS_COMPAT_FEATURE(inode->i_sb,
780 EXT4_FEATURE_COMPAT_DIR_INDEX))
781 ext4_clear_inode_flag(inode, EXT4_INODE_INDEX);
782}
783
784/*
785 * NOTE! unlike strncmp, ext4_match returns 1 for success, 0 for failure.
786 *
787 * `len <= EXT4_NAME_LEN' is guaranteed by caller.
788 * `de != NULL' is guaranteed by caller.
789 */
790static inline int ext4_match (int len, const char * const name,
791 struct ext4_dir_entry_2 * de)
792{
793 if (len != de->name_len)
794 return 0;
795 if (!de->inode)
796 return 0;
797 return !memcmp(name, de->name, len);
798}
799
800/*
801 * Returns 0 if not found, -1 on failure, and 1 on success
802 */
803static inline int search_dirblock(struct buffer_head *bh,
804 struct inode *dir,
805 const struct qstr *d_name,
806 unsigned int offset,
807 struct ext4_dir_entry_2 ** res_dir)
808{
809 struct ext4_dir_entry_2 * de;
810 char * dlimit;
811 int de_len;
812 const char *name = d_name->name;
813 int namelen = d_name->len;
814
815 de = (struct ext4_dir_entry_2 *) bh->b_data;
816 dlimit = bh->b_data + dir->i_sb->s_blocksize;
817 while ((char *) de < dlimit) {
818 /* this code is executed quadratically often */
819 /* do minimal checking `by hand' */
820
821 if ((char *) de + namelen <= dlimit &&
822 ext4_match (namelen, name, de)) {
823 /* found a match - just to be sure, do a full check */
824 if (ext4_check_dir_entry(dir, NULL, de, bh, offset))
825 return -1;
826 *res_dir = de;
827 return 1;
828 }
829 /* prevent looping on a bad block */
830 de_len = ext4_rec_len_from_disk(de->rec_len,
831 dir->i_sb->s_blocksize);
832 if (de_len <= 0)
833 return -1;
834 offset += de_len;
835 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
836 }
837 return 0;
838}
839
840
841/*
842 * ext4_find_entry()
843 *
844 * finds an entry in the specified directory with the wanted name. It
845 * returns the cache buffer in which the entry was found, and the entry
846 * itself (as a parameter - res_dir). It does NOT read the inode of the
847 * entry - you'll have to do that yourself if you want to.
848 *
849 * The returned buffer_head has ->b_count elevated. The caller is expected
850 * to brelse() it when appropriate.
851 */
852static struct buffer_head * ext4_find_entry (struct inode *dir,
853 const struct qstr *d_name,
854 struct ext4_dir_entry_2 ** res_dir)
855{
856 struct super_block *sb;
857 struct buffer_head *bh_use[NAMEI_RA_SIZE];
858 struct buffer_head *bh, *ret = NULL;
859 ext4_lblk_t start, block, b;
860 const u8 *name = d_name->name;
861 int ra_max = 0; /* Number of bh's in the readahead
862 buffer, bh_use[] */
863 int ra_ptr = 0; /* Current index into readahead
864 buffer */
865 int num = 0;
866 ext4_lblk_t nblocks;
867 int i, err;
868 int namelen;
869
870 *res_dir = NULL;
871 sb = dir->i_sb;
872 namelen = d_name->len;
873 if (namelen > EXT4_NAME_LEN)
874 return NULL;
875 if ((namelen <= 2) && (name[0] == '.') &&
876 (name[1] == '.' || name[1] == '\0')) {
877 /*
878 * "." or ".." will only be in the first block
879 * NFS may look up ".."; "." should be handled by the VFS
880 */
881 block = start = 0;
882 nblocks = 1;
883 goto restart;
884 }
885 if (is_dx(dir)) {
886 bh = ext4_dx_find_entry(dir, d_name, res_dir, &err);
887 /*
888 * On success, or if the error was file not found,
889 * return. Otherwise, fall back to doing a search the
890 * old fashioned way.
891 */
892 if (bh || (err != ERR_BAD_DX_DIR))
893 return bh;
894 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
895 "falling back\n"));
896 }
897 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
898 start = EXT4_I(dir)->i_dir_start_lookup;
899 if (start >= nblocks)
900 start = 0;
901 block = start;
902restart:
903 do {
904 /*
905 * We deal with the read-ahead logic here.
906 */
907 if (ra_ptr >= ra_max) {
908 /* Refill the readahead buffer */
909 ra_ptr = 0;
910 b = block;
911 for (ra_max = 0; ra_max < NAMEI_RA_SIZE; ra_max++) {
912 /*
913 * Terminate if we reach the end of the
914 * directory and must wrap, or if our
915 * search has finished at this block.
916 */
917 if (b >= nblocks || (num && block == start)) {
918 bh_use[ra_max] = NULL;
919 break;
920 }
921 num++;
922 bh = ext4_getblk(NULL, dir, b++, 0, &err);
923 bh_use[ra_max] = bh;
924 if (bh)
925 ll_rw_block(READ | REQ_META | REQ_PRIO,
926 1, &bh);
927 }
928 }
929 if ((bh = bh_use[ra_ptr++]) == NULL)
930 goto next;
931 wait_on_buffer(bh);
932 if (!buffer_uptodate(bh)) {
933 /* read error, skip block & hope for the best */
934 EXT4_ERROR_INODE(dir, "reading directory lblock %lu",
935 (unsigned long) block);
936 brelse(bh);
937 goto next;
938 }
939 i = search_dirblock(bh, dir, d_name,
940 block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
941 if (i == 1) {
942 EXT4_I(dir)->i_dir_start_lookup = block;
943 ret = bh;
944 goto cleanup_and_exit;
945 } else {
946 brelse(bh);
947 if (i < 0)
948 goto cleanup_and_exit;
949 }
950 next:
951 if (++block >= nblocks)
952 block = 0;
953 } while (block != start);
954
955 /*
956 * If the directory has grown while we were searching, then
957 * search the last part of the directory before giving up.
958 */
959 block = nblocks;
960 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
961 if (block < nblocks) {
962 start = 0;
963 goto restart;
964 }
965
966cleanup_and_exit:
967 /* Clean up the read-ahead blocks */
968 for (; ra_ptr < ra_max; ra_ptr++)
969 brelse(bh_use[ra_ptr]);
970 return ret;
971}
972
973static struct buffer_head * ext4_dx_find_entry(struct inode *dir, const struct qstr *d_name,
974 struct ext4_dir_entry_2 **res_dir, int *err)
975{
976 struct super_block * sb = dir->i_sb;
977 struct dx_hash_info hinfo;
978 struct dx_frame frames[2], *frame;
979 struct buffer_head *bh;
980 ext4_lblk_t block;
981 int retval;
982
983 if (!(frame = dx_probe(d_name, dir, &hinfo, frames, err)))
984 return NULL;
985 do {
986 block = dx_get_block(frame->at);
987 if (!(bh = ext4_bread(NULL, dir, block, 0, err)))
988 goto errout;
989
990 retval = search_dirblock(bh, dir, d_name,
991 block << EXT4_BLOCK_SIZE_BITS(sb),
992 res_dir);
993 if (retval == 1) { /* Success! */
994 dx_release(frames);
995 return bh;
996 }
997 brelse(bh);
998 if (retval == -1) {
999 *err = ERR_BAD_DX_DIR;
1000 goto errout;
1001 }
1002
1003 /* Check to see if we should continue to search */
1004 retval = ext4_htree_next_block(dir, hinfo.hash, frame,
1005 frames, NULL);
1006 if (retval < 0) {
1007 ext4_warning(sb,
1008 "error reading index page in directory #%lu",
1009 dir->i_ino);
1010 *err = retval;
1011 goto errout;
1012 }
1013 } while (retval == 1);
1014
1015 *err = -ENOENT;
1016errout:
1017 dxtrace(printk(KERN_DEBUG "%s not found\n", d_name->name));
1018 dx_release (frames);
1019 return NULL;
1020}
1021
1022static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
1023{
1024 struct inode *inode;
1025 struct ext4_dir_entry_2 *de;
1026 struct buffer_head *bh;
1027
1028 if (dentry->d_name.len > EXT4_NAME_LEN)
1029 return ERR_PTR(-ENAMETOOLONG);
1030
1031 bh = ext4_find_entry(dir, &dentry->d_name, &de);
1032 inode = NULL;
1033 if (bh) {
1034 __u32 ino = le32_to_cpu(de->inode);
1035 brelse(bh);
1036 if (!ext4_valid_inum(dir->i_sb, ino)) {
1037 EXT4_ERROR_INODE(dir, "bad inode number: %u", ino);
1038 return ERR_PTR(-EIO);
1039 }
1040 inode = ext4_iget(dir->i_sb, ino);
1041 if (inode == ERR_PTR(-ESTALE)) {
1042 EXT4_ERROR_INODE(dir,
1043 "deleted inode referenced: %u",
1044 ino);
1045 return ERR_PTR(-EIO);
1046 }
1047 }
1048 return d_splice_alias(inode, dentry);
1049}
1050
1051
1052struct dentry *ext4_get_parent(struct dentry *child)
1053{
1054 __u32 ino;
1055 static const struct qstr dotdot = {
1056 .name = "..",
1057 .len = 2,
1058 };
1059 struct ext4_dir_entry_2 * de;
1060 struct buffer_head *bh;
1061
1062 bh = ext4_find_entry(child->d_inode, &dotdot, &de);
1063 if (!bh)
1064 return ERR_PTR(-ENOENT);
1065 ino = le32_to_cpu(de->inode);
1066 brelse(bh);
1067
1068 if (!ext4_valid_inum(child->d_inode->i_sb, ino)) {
1069 EXT4_ERROR_INODE(child->d_inode,
1070 "bad parent inode number: %u", ino);
1071 return ERR_PTR(-EIO);
1072 }
1073
1074 return d_obtain_alias(ext4_iget(child->d_inode->i_sb, ino));
1075}
1076
1077#define S_SHIFT 12
1078static unsigned char ext4_type_by_mode[S_IFMT >> S_SHIFT] = {
1079 [S_IFREG >> S_SHIFT] = EXT4_FT_REG_FILE,
1080 [S_IFDIR >> S_SHIFT] = EXT4_FT_DIR,
1081 [S_IFCHR >> S_SHIFT] = EXT4_FT_CHRDEV,
1082 [S_IFBLK >> S_SHIFT] = EXT4_FT_BLKDEV,
1083 [S_IFIFO >> S_SHIFT] = EXT4_FT_FIFO,
1084 [S_IFSOCK >> S_SHIFT] = EXT4_FT_SOCK,
1085 [S_IFLNK >> S_SHIFT] = EXT4_FT_SYMLINK,
1086};
1087
1088static inline void ext4_set_de_type(struct super_block *sb,
1089 struct ext4_dir_entry_2 *de,
1090 umode_t mode) {
1091 if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE))
1092 de->file_type = ext4_type_by_mode[(mode & S_IFMT)>>S_SHIFT];
1093}
1094
1095/*
1096 * Move count entries from end of map between two memory locations.
1097 * Returns pointer to last entry moved.
1098 */
1099static struct ext4_dir_entry_2 *
1100dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count,
1101 unsigned blocksize)
1102{
1103 unsigned rec_len = 0;
1104
1105 while (count--) {
1106 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
1107 (from + (map->offs<<2));
1108 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1109 memcpy (to, de, rec_len);
1110 ((struct ext4_dir_entry_2 *) to)->rec_len =
1111 ext4_rec_len_to_disk(rec_len, blocksize);
1112 de->inode = 0;
1113 map++;
1114 to += rec_len;
1115 }
1116 return (struct ext4_dir_entry_2 *) (to - rec_len);
1117}
1118
1119/*
1120 * Compact each dir entry in the range to the minimal rec_len.
1121 * Returns pointer to last entry in range.
1122 */
1123static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize)
1124{
1125 struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
1126 unsigned rec_len = 0;
1127
1128 prev = to = de;
1129 while ((char*)de < base + blocksize) {
1130 next = ext4_next_entry(de, blocksize);
1131 if (de->inode && de->name_len) {
1132 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1133 if (de > to)
1134 memmove(to, de, rec_len);
1135 to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
1136 prev = to;
1137 to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
1138 }
1139 de = next;
1140 }
1141 return prev;
1142}
1143
1144/*
1145 * Split a full leaf block to make room for a new dir entry.
1146 * Allocate a new block, and move entries so that they are approx. equally full.
1147 * Returns pointer to de in block into which the new entry will be inserted.
1148 */
1149static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
1150 struct buffer_head **bh,struct dx_frame *frame,
1151 struct dx_hash_info *hinfo, int *error)
1152{
1153 unsigned blocksize = dir->i_sb->s_blocksize;
1154 unsigned count, continued;
1155 struct buffer_head *bh2;
1156 ext4_lblk_t newblock;
1157 u32 hash2;
1158 struct dx_map_entry *map;
1159 char *data1 = (*bh)->b_data, *data2;
1160 unsigned split, move, size;
1161 struct ext4_dir_entry_2 *de = NULL, *de2;
1162 int err = 0, i;
1163
1164 bh2 = ext4_append (handle, dir, &newblock, &err);
1165 if (!(bh2)) {
1166 brelse(*bh);
1167 *bh = NULL;
1168 goto errout;
1169 }
1170
1171 BUFFER_TRACE(*bh, "get_write_access");
1172 err = ext4_journal_get_write_access(handle, *bh);
1173 if (err)
1174 goto journal_error;
1175
1176 BUFFER_TRACE(frame->bh, "get_write_access");
1177 err = ext4_journal_get_write_access(handle, frame->bh);
1178 if (err)
1179 goto journal_error;
1180
1181 data2 = bh2->b_data;
1182
1183 /* create map in the end of data2 block */
1184 map = (struct dx_map_entry *) (data2 + blocksize);
1185 count = dx_make_map((struct ext4_dir_entry_2 *) data1,
1186 blocksize, hinfo, map);
1187 map -= count;
1188 dx_sort_map(map, count);
1189 /* Split the existing block in the middle, size-wise */
1190 size = 0;
1191 move = 0;
1192 for (i = count-1; i >= 0; i--) {
1193 /* is more than half of this entry in 2nd half of the block? */
1194 if (size + map[i].size/2 > blocksize/2)
1195 break;
1196 size += map[i].size;
1197 move++;
1198 }
1199 /* map index at which we will split */
1200 split = count - move;
1201 hash2 = map[split].hash;
1202 continued = hash2 == map[split - 1].hash;
1203 dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
1204 (unsigned long)dx_get_block(frame->at),
1205 hash2, split, count-split));
1206
1207 /* Fancy dance to stay within two buffers */
1208 de2 = dx_move_dirents(data1, data2, map + split, count - split, blocksize);
1209 de = dx_pack_dirents(data1, blocksize);
1210 de->rec_len = ext4_rec_len_to_disk(data1 + blocksize - (char *) de,
1211 blocksize);
1212 de2->rec_len = ext4_rec_len_to_disk(data2 + blocksize - (char *) de2,
1213 blocksize);
1214 dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data1, blocksize, 1));
1215 dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data2, blocksize, 1));
1216
1217 /* Which block gets the new entry? */
1218 if (hinfo->hash >= hash2)
1219 {
1220 swap(*bh, bh2);
1221 de = de2;
1222 }
1223 dx_insert_block(frame, hash2 + continued, newblock);
1224 err = ext4_handle_dirty_metadata(handle, dir, bh2);
1225 if (err)
1226 goto journal_error;
1227 err = ext4_handle_dirty_metadata(handle, dir, frame->bh);
1228 if (err)
1229 goto journal_error;
1230 brelse(bh2);
1231 dxtrace(dx_show_index("frame", frame->entries));
1232 return de;
1233
1234journal_error:
1235 brelse(*bh);
1236 brelse(bh2);
1237 *bh = NULL;
1238 ext4_std_error(dir->i_sb, err);
1239errout:
1240 *error = err;
1241 return NULL;
1242}
1243
1244/*
1245 * Add a new entry into a directory (leaf) block. If de is non-NULL,
1246 * it points to a directory entry which is guaranteed to be large
1247 * enough for new directory entry. If de is NULL, then
1248 * add_dirent_to_buf will attempt search the directory block for
1249 * space. It will return -ENOSPC if no space is available, and -EIO
1250 * and -EEXIST if directory entry already exists.
1251 */
1252static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
1253 struct inode *inode, struct ext4_dir_entry_2 *de,
1254 struct buffer_head *bh)
1255{
1256 struct inode *dir = dentry->d_parent->d_inode;
1257 const char *name = dentry->d_name.name;
1258 int namelen = dentry->d_name.len;
1259 unsigned int offset = 0;
1260 unsigned int blocksize = dir->i_sb->s_blocksize;
1261 unsigned short reclen;
1262 int nlen, rlen, err;
1263 char *top;
1264
1265 reclen = EXT4_DIR_REC_LEN(namelen);
1266 if (!de) {
1267 de = (struct ext4_dir_entry_2 *)bh->b_data;
1268 top = bh->b_data + blocksize - reclen;
1269 while ((char *) de <= top) {
1270 if (ext4_check_dir_entry(dir, NULL, de, bh, offset))
1271 return -EIO;
1272 if (ext4_match(namelen, name, de))
1273 return -EEXIST;
1274 nlen = EXT4_DIR_REC_LEN(de->name_len);
1275 rlen = ext4_rec_len_from_disk(de->rec_len, blocksize);
1276 if ((de->inode? rlen - nlen: rlen) >= reclen)
1277 break;
1278 de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
1279 offset += rlen;
1280 }
1281 if ((char *) de > top)
1282 return -ENOSPC;
1283 }
1284 BUFFER_TRACE(bh, "get_write_access");
1285 err = ext4_journal_get_write_access(handle, bh);
1286 if (err) {
1287 ext4_std_error(dir->i_sb, err);
1288 return err;
1289 }
1290
1291 /* By now the buffer is marked for journaling */
1292 nlen = EXT4_DIR_REC_LEN(de->name_len);
1293 rlen = ext4_rec_len_from_disk(de->rec_len, blocksize);
1294 if (de->inode) {
1295 struct ext4_dir_entry_2 *de1 = (struct ext4_dir_entry_2 *)((char *)de + nlen);
1296 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, blocksize);
1297 de->rec_len = ext4_rec_len_to_disk(nlen, blocksize);
1298 de = de1;
1299 }
1300 de->file_type = EXT4_FT_UNKNOWN;
1301 if (inode) {
1302 de->inode = cpu_to_le32(inode->i_ino);
1303 ext4_set_de_type(dir->i_sb, de, inode->i_mode);
1304 } else
1305 de->inode = 0;
1306 de->name_len = namelen;
1307 memcpy(de->name, name, namelen);
1308 /*
1309 * XXX shouldn't update any times until successful
1310 * completion of syscall, but too many callers depend
1311 * on this.
1312 *
1313 * XXX similarly, too many callers depend on
1314 * ext4_new_inode() setting the times, but error
1315 * recovery deletes the inode, so the worst that can
1316 * happen is that the times are slightly out of date
1317 * and/or different from the directory change time.
1318 */
1319 dir->i_mtime = dir->i_ctime = ext4_current_time(dir);
1320 ext4_update_dx_flag(dir);
1321 dir->i_version++;
1322 ext4_mark_inode_dirty(handle, dir);
1323 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1324 err = ext4_handle_dirty_metadata(handle, dir, bh);
1325 if (err)
1326 ext4_std_error(dir->i_sb, err);
1327 return 0;
1328}
1329
1330/*
1331 * This converts a one block unindexed directory to a 3 block indexed
1332 * directory, and adds the dentry to the indexed directory.
1333 */
1334static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
1335 struct inode *inode, struct buffer_head *bh)
1336{
1337 struct inode *dir = dentry->d_parent->d_inode;
1338 const char *name = dentry->d_name.name;
1339 int namelen = dentry->d_name.len;
1340 struct buffer_head *bh2;
1341 struct dx_root *root;
1342 struct dx_frame frames[2], *frame;
1343 struct dx_entry *entries;
1344 struct ext4_dir_entry_2 *de, *de2;
1345 char *data1, *top;
1346 unsigned len;
1347 int retval;
1348 unsigned blocksize;
1349 struct dx_hash_info hinfo;
1350 ext4_lblk_t block;
1351 struct fake_dirent *fde;
1352
1353 blocksize = dir->i_sb->s_blocksize;
1354 dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
1355 retval = ext4_journal_get_write_access(handle, bh);
1356 if (retval) {
1357 ext4_std_error(dir->i_sb, retval);
1358 brelse(bh);
1359 return retval;
1360 }
1361 root = (struct dx_root *) bh->b_data;
1362
1363 /* The 0th block becomes the root, move the dirents out */
1364 fde = &root->dotdot;
1365 de = (struct ext4_dir_entry_2 *)((char *)fde +
1366 ext4_rec_len_from_disk(fde->rec_len, blocksize));
1367 if ((char *) de >= (((char *) root) + blocksize)) {
1368 EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
1369 brelse(bh);
1370 return -EIO;
1371 }
1372 len = ((char *) root) + blocksize - (char *) de;
1373
1374 /* Allocate new block for the 0th block's dirents */
1375 bh2 = ext4_append(handle, dir, &block, &retval);
1376 if (!(bh2)) {
1377 brelse(bh);
1378 return retval;
1379 }
1380 ext4_set_inode_flag(dir, EXT4_INODE_INDEX);
1381 data1 = bh2->b_data;
1382
1383 memcpy (data1, de, len);
1384 de = (struct ext4_dir_entry_2 *) data1;
1385 top = data1 + len;
1386 while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
1387 de = de2;
1388 de->rec_len = ext4_rec_len_to_disk(data1 + blocksize - (char *) de,
1389 blocksize);
1390 /* Initialize the root; the dot dirents already exist */
1391 de = (struct ext4_dir_entry_2 *) (&root->dotdot);
1392 de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
1393 blocksize);
1394 memset (&root->info, 0, sizeof(root->info));
1395 root->info.info_length = sizeof(root->info);
1396 root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
1397 entries = root->entries;
1398 dx_set_block(entries, 1);
1399 dx_set_count(entries, 1);
1400 dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
1401
1402 /* Initialize as for dx_probe */
1403 hinfo.hash_version = root->info.hash_version;
1404 if (hinfo.hash_version <= DX_HASH_TEA)
1405 hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
1406 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
1407 ext4fs_dirhash(name, namelen, &hinfo);
1408 frame = frames;
1409 frame->entries = entries;
1410 frame->at = entries;
1411 frame->bh = bh;
1412 bh = bh2;
1413
1414 ext4_handle_dirty_metadata(handle, dir, frame->bh);
1415 ext4_handle_dirty_metadata(handle, dir, bh);
1416
1417 de = do_split(handle,dir, &bh, frame, &hinfo, &retval);
1418 if (!de) {
1419 /*
1420 * Even if the block split failed, we have to properly write
1421 * out all the changes we did so far. Otherwise we can end up
1422 * with corrupted filesystem.
1423 */
1424 ext4_mark_inode_dirty(handle, dir);
1425 dx_release(frames);
1426 return retval;
1427 }
1428 dx_release(frames);
1429
1430 retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
1431 brelse(bh);
1432 return retval;
1433}
1434
1435/*
1436 * ext4_add_entry()
1437 *
1438 * adds a file entry to the specified directory, using the same
1439 * semantics as ext4_find_entry(). It returns NULL if it failed.
1440 *
1441 * NOTE!! The inode part of 'de' is left at 0 - which means you
1442 * may not sleep between calling this and putting something into
1443 * the entry, as someone else might have used it while you slept.
1444 */
1445static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
1446 struct inode *inode)
1447{
1448 struct inode *dir = dentry->d_parent->d_inode;
1449 struct buffer_head *bh;
1450 struct ext4_dir_entry_2 *de;
1451 struct super_block *sb;
1452 int retval;
1453 int dx_fallback=0;
1454 unsigned blocksize;
1455 ext4_lblk_t block, blocks;
1456
1457 sb = dir->i_sb;
1458 blocksize = sb->s_blocksize;
1459 if (!dentry->d_name.len)
1460 return -EINVAL;
1461 if (is_dx(dir)) {
1462 retval = ext4_dx_add_entry(handle, dentry, inode);
1463 if (!retval || (retval != ERR_BAD_DX_DIR))
1464 return retval;
1465 ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
1466 dx_fallback++;
1467 ext4_mark_inode_dirty(handle, dir);
1468 }
1469 blocks = dir->i_size >> sb->s_blocksize_bits;
1470 for (block = 0; block < blocks; block++) {
1471 bh = ext4_bread(handle, dir, block, 0, &retval);
1472 if(!bh)
1473 return retval;
1474 retval = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
1475 if (retval != -ENOSPC) {
1476 brelse(bh);
1477 return retval;
1478 }
1479
1480 if (blocks == 1 && !dx_fallback &&
1481 EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX))
1482 return make_indexed_dir(handle, dentry, inode, bh);
1483 brelse(bh);
1484 }
1485 bh = ext4_append(handle, dir, &block, &retval);
1486 if (!bh)
1487 return retval;
1488 de = (struct ext4_dir_entry_2 *) bh->b_data;
1489 de->inode = 0;
1490 de->rec_len = ext4_rec_len_to_disk(blocksize, blocksize);
1491 retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
1492 brelse(bh);
1493 if (retval == 0)
1494 ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY);
1495 return retval;
1496}
1497
1498/*
1499 * Returns 0 for success, or a negative error value
1500 */
1501static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
1502 struct inode *inode)
1503{
1504 struct dx_frame frames[2], *frame;
1505 struct dx_entry *entries, *at;
1506 struct dx_hash_info hinfo;
1507 struct buffer_head *bh;
1508 struct inode *dir = dentry->d_parent->d_inode;
1509 struct super_block *sb = dir->i_sb;
1510 struct ext4_dir_entry_2 *de;
1511 int err;
1512
1513 frame = dx_probe(&dentry->d_name, dir, &hinfo, frames, &err);
1514 if (!frame)
1515 return err;
1516 entries = frame->entries;
1517 at = frame->at;
1518
1519 if (!(bh = ext4_bread(handle,dir, dx_get_block(frame->at), 0, &err)))
1520 goto cleanup;
1521
1522 BUFFER_TRACE(bh, "get_write_access");
1523 err = ext4_journal_get_write_access(handle, bh);
1524 if (err)
1525 goto journal_error;
1526
1527 err = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
1528 if (err != -ENOSPC)
1529 goto cleanup;
1530
1531 /* Block full, should compress but for now just split */
1532 dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
1533 dx_get_count(entries), dx_get_limit(entries)));
1534 /* Need to split index? */
1535 if (dx_get_count(entries) == dx_get_limit(entries)) {
1536 ext4_lblk_t newblock;
1537 unsigned icount = dx_get_count(entries);
1538 int levels = frame - frames;
1539 struct dx_entry *entries2;
1540 struct dx_node *node2;
1541 struct buffer_head *bh2;
1542
1543 if (levels && (dx_get_count(frames->entries) ==
1544 dx_get_limit(frames->entries))) {
1545 ext4_warning(sb, "Directory index full!");
1546 err = -ENOSPC;
1547 goto cleanup;
1548 }
1549 bh2 = ext4_append (handle, dir, &newblock, &err);
1550 if (!(bh2))
1551 goto cleanup;
1552 node2 = (struct dx_node *)(bh2->b_data);
1553 entries2 = node2->entries;
1554 memset(&node2->fake, 0, sizeof(struct fake_dirent));
1555 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
1556 sb->s_blocksize);
1557 BUFFER_TRACE(frame->bh, "get_write_access");
1558 err = ext4_journal_get_write_access(handle, frame->bh);
1559 if (err)
1560 goto journal_error;
1561 if (levels) {
1562 unsigned icount1 = icount/2, icount2 = icount - icount1;
1563 unsigned hash2 = dx_get_hash(entries + icount1);
1564 dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
1565 icount1, icount2));
1566
1567 BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
1568 err = ext4_journal_get_write_access(handle,
1569 frames[0].bh);
1570 if (err)
1571 goto journal_error;
1572
1573 memcpy((char *) entries2, (char *) (entries + icount1),
1574 icount2 * sizeof(struct dx_entry));
1575 dx_set_count(entries, icount1);
1576 dx_set_count(entries2, icount2);
1577 dx_set_limit(entries2, dx_node_limit(dir));
1578
1579 /* Which index block gets the new entry? */
1580 if (at - entries >= icount1) {
1581 frame->at = at = at - entries - icount1 + entries2;
1582 frame->entries = entries = entries2;
1583 swap(frame->bh, bh2);
1584 }
1585 dx_insert_block(frames + 0, hash2, newblock);
1586 dxtrace(dx_show_index("node", frames[1].entries));
1587 dxtrace(dx_show_index("node",
1588 ((struct dx_node *) bh2->b_data)->entries));
1589 err = ext4_handle_dirty_metadata(handle, inode, bh2);
1590 if (err)
1591 goto journal_error;
1592 brelse (bh2);
1593 } else {
1594 dxtrace(printk(KERN_DEBUG
1595 "Creating second level index...\n"));
1596 memcpy((char *) entries2, (char *) entries,
1597 icount * sizeof(struct dx_entry));
1598 dx_set_limit(entries2, dx_node_limit(dir));
1599
1600 /* Set up root */
1601 dx_set_count(entries, 1);
1602 dx_set_block(entries + 0, newblock);
1603 ((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels = 1;
1604
1605 /* Add new access path frame */
1606 frame = frames + 1;
1607 frame->at = at = at - entries + entries2;
1608 frame->entries = entries = entries2;
1609 frame->bh = bh2;
1610 err = ext4_journal_get_write_access(handle,
1611 frame->bh);
1612 if (err)
1613 goto journal_error;
1614 }
1615 err = ext4_handle_dirty_metadata(handle, inode, frames[0].bh);
1616 if (err) {
1617 ext4_std_error(inode->i_sb, err);
1618 goto cleanup;
1619 }
1620 }
1621 de = do_split(handle, dir, &bh, frame, &hinfo, &err);
1622 if (!de)
1623 goto cleanup;
1624 err = add_dirent_to_buf(handle, dentry, inode, de, bh);
1625 goto cleanup;
1626
1627journal_error:
1628 ext4_std_error(dir->i_sb, err);
1629cleanup:
1630 if (bh)
1631 brelse(bh);
1632 dx_release(frames);
1633 return err;
1634}
1635
1636/*
1637 * ext4_delete_entry deletes a directory entry by merging it with the
1638 * previous entry
1639 */
1640static int ext4_delete_entry(handle_t *handle,
1641 struct inode *dir,
1642 struct ext4_dir_entry_2 *de_del,
1643 struct buffer_head *bh)
1644{
1645 struct ext4_dir_entry_2 *de, *pde;
1646 unsigned int blocksize = dir->i_sb->s_blocksize;
1647 int i, err;
1648
1649 i = 0;
1650 pde = NULL;
1651 de = (struct ext4_dir_entry_2 *) bh->b_data;
1652 while (i < bh->b_size) {
1653 if (ext4_check_dir_entry(dir, NULL, de, bh, i))
1654 return -EIO;
1655 if (de == de_del) {
1656 BUFFER_TRACE(bh, "get_write_access");
1657 err = ext4_journal_get_write_access(handle, bh);
1658 if (unlikely(err)) {
1659 ext4_std_error(dir->i_sb, err);
1660 return err;
1661 }
1662 if (pde)
1663 pde->rec_len = ext4_rec_len_to_disk(
1664 ext4_rec_len_from_disk(pde->rec_len,
1665 blocksize) +
1666 ext4_rec_len_from_disk(de->rec_len,
1667 blocksize),
1668 blocksize);
1669 else
1670 de->inode = 0;
1671 dir->i_version++;
1672 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1673 err = ext4_handle_dirty_metadata(handle, dir, bh);
1674 if (unlikely(err)) {
1675 ext4_std_error(dir->i_sb, err);
1676 return err;
1677 }
1678 return 0;
1679 }
1680 i += ext4_rec_len_from_disk(de->rec_len, blocksize);
1681 pde = de;
1682 de = ext4_next_entry(de, blocksize);
1683 }
1684 return -ENOENT;
1685}
1686
1687/*
1688 * DIR_NLINK feature is set if 1) nlinks > EXT4_LINK_MAX or 2) nlinks == 2,
1689 * since this indicates that nlinks count was previously 1.
1690 */
1691static void ext4_inc_count(handle_t *handle, struct inode *inode)
1692{
1693 inc_nlink(inode);
1694 if (is_dx(inode) && inode->i_nlink > 1) {
1695 /* limit is 16-bit i_links_count */
1696 if (inode->i_nlink >= EXT4_LINK_MAX || inode->i_nlink == 2) {
1697 inode->i_nlink = 1;
1698 EXT4_SET_RO_COMPAT_FEATURE(inode->i_sb,
1699 EXT4_FEATURE_RO_COMPAT_DIR_NLINK);
1700 }
1701 }
1702}
1703
1704/*
1705 * If a directory had nlink == 1, then we should let it be 1. This indicates
1706 * directory has >EXT4_LINK_MAX subdirs.
1707 */
1708static void ext4_dec_count(handle_t *handle, struct inode *inode)
1709{
1710 drop_nlink(inode);
1711 if (S_ISDIR(inode->i_mode) && inode->i_nlink == 0)
1712 inc_nlink(inode);
1713}
1714
1715
1716static int ext4_add_nondir(handle_t *handle,
1717 struct dentry *dentry, struct inode *inode)
1718{
1719 int err = ext4_add_entry(handle, dentry, inode);
1720 if (!err) {
1721 ext4_mark_inode_dirty(handle, inode);
1722 d_instantiate(dentry, inode);
1723 unlock_new_inode(inode);
1724 return 0;
1725 }
1726 drop_nlink(inode);
1727 unlock_new_inode(inode);
1728 iput(inode);
1729 return err;
1730}
1731
1732/*
1733 * By the time this is called, we already have created
1734 * the directory cache entry for the new file, but it
1735 * is so far negative - it has no inode.
1736 *
1737 * If the create succeeds, we fill in the inode information
1738 * with d_instantiate().
1739 */
1740static int ext4_create(struct inode *dir, struct dentry *dentry, int mode,
1741 struct nameidata *nd)
1742{
1743 handle_t *handle;
1744 struct inode *inode;
1745 int err, retries = 0;
1746
1747 dquot_initialize(dir);
1748
1749retry:
1750 handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
1751 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
1752 EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
1753 if (IS_ERR(handle))
1754 return PTR_ERR(handle);
1755
1756 if (IS_DIRSYNC(dir))
1757 ext4_handle_sync(handle);
1758
1759 inode = ext4_new_inode(handle, dir, mode, &dentry->d_name, 0);
1760 err = PTR_ERR(inode);
1761 if (!IS_ERR(inode)) {
1762 inode->i_op = &ext4_file_inode_operations;
1763 inode->i_fop = &ext4_file_operations;
1764 ext4_set_aops(inode);
1765 err = ext4_add_nondir(handle, dentry, inode);
1766 }
1767 ext4_journal_stop(handle);
1768 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
1769 goto retry;
1770 return err;
1771}
1772
1773static int ext4_mknod(struct inode *dir, struct dentry *dentry,
1774 int mode, dev_t rdev)
1775{
1776 handle_t *handle;
1777 struct inode *inode;
1778 int err, retries = 0;
1779
1780 if (!new_valid_dev(rdev))
1781 return -EINVAL;
1782
1783 dquot_initialize(dir);
1784
1785retry:
1786 handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
1787 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
1788 EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
1789 if (IS_ERR(handle))
1790 return PTR_ERR(handle);
1791
1792 if (IS_DIRSYNC(dir))
1793 ext4_handle_sync(handle);
1794
1795 inode = ext4_new_inode(handle, dir, mode, &dentry->d_name, 0);
1796 err = PTR_ERR(inode);
1797 if (!IS_ERR(inode)) {
1798 init_special_inode(inode, inode->i_mode, rdev);
1799#ifdef CONFIG_EXT4_FS_XATTR
1800 inode->i_op = &ext4_special_inode_operations;
1801#endif
1802 err = ext4_add_nondir(handle, dentry, inode);
1803 }
1804 ext4_journal_stop(handle);
1805 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
1806 goto retry;
1807 return err;
1808}
1809
1810static int ext4_mkdir(struct inode *dir, struct dentry *dentry, int mode)
1811{
1812 handle_t *handle;
1813 struct inode *inode;
1814 struct buffer_head *dir_block = NULL;
1815 struct ext4_dir_entry_2 *de;
1816 unsigned int blocksize = dir->i_sb->s_blocksize;
1817 int err, retries = 0;
1818
1819 if (EXT4_DIR_LINK_MAX(dir))
1820 return -EMLINK;
1821
1822 dquot_initialize(dir);
1823
1824retry:
1825 handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
1826 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
1827 EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
1828 if (IS_ERR(handle))
1829 return PTR_ERR(handle);
1830
1831 if (IS_DIRSYNC(dir))
1832 ext4_handle_sync(handle);
1833
1834 inode = ext4_new_inode(handle, dir, S_IFDIR | mode,
1835 &dentry->d_name, 0);
1836 err = PTR_ERR(inode);
1837 if (IS_ERR(inode))
1838 goto out_stop;
1839
1840 inode->i_op = &ext4_dir_inode_operations;
1841 inode->i_fop = &ext4_dir_operations;
1842 inode->i_size = EXT4_I(inode)->i_disksize = inode->i_sb->s_blocksize;
1843 dir_block = ext4_bread(handle, inode, 0, 1, &err);
1844 if (!dir_block)
1845 goto out_clear_inode;
1846 BUFFER_TRACE(dir_block, "get_write_access");
1847 err = ext4_journal_get_write_access(handle, dir_block);
1848 if (err)
1849 goto out_clear_inode;
1850 de = (struct ext4_dir_entry_2 *) dir_block->b_data;
1851 de->inode = cpu_to_le32(inode->i_ino);
1852 de->name_len = 1;
1853 de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
1854 blocksize);
1855 strcpy(de->name, ".");
1856 ext4_set_de_type(dir->i_sb, de, S_IFDIR);
1857 de = ext4_next_entry(de, blocksize);
1858 de->inode = cpu_to_le32(dir->i_ino);
1859 de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(1),
1860 blocksize);
1861 de->name_len = 2;
1862 strcpy(de->name, "..");
1863 ext4_set_de_type(dir->i_sb, de, S_IFDIR);
1864 inode->i_nlink = 2;
1865 BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
1866 err = ext4_handle_dirty_metadata(handle, dir, dir_block);
1867 if (err)
1868 goto out_clear_inode;
1869 err = ext4_mark_inode_dirty(handle, inode);
1870 if (!err)
1871 err = ext4_add_entry(handle, dentry, inode);
1872 if (err) {
1873out_clear_inode:
1874 clear_nlink(inode);
1875 unlock_new_inode(inode);
1876 ext4_mark_inode_dirty(handle, inode);
1877 iput(inode);
1878 goto out_stop;
1879 }
1880 ext4_inc_count(handle, dir);
1881 ext4_update_dx_flag(dir);
1882 err = ext4_mark_inode_dirty(handle, dir);
1883 if (err)
1884 goto out_clear_inode;
1885 d_instantiate(dentry, inode);
1886 unlock_new_inode(inode);
1887out_stop:
1888 brelse(dir_block);
1889 ext4_journal_stop(handle);
1890 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
1891 goto retry;
1892 return err;
1893}
1894
1895/*
1896 * routine to check that the specified directory is empty (for rmdir)
1897 */
1898static int empty_dir(struct inode *inode)
1899{
1900 unsigned int offset;
1901 struct buffer_head *bh;
1902 struct ext4_dir_entry_2 *de, *de1;
1903 struct super_block *sb;
1904 int err = 0;
1905
1906 sb = inode->i_sb;
1907 if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2) ||
1908 !(bh = ext4_bread(NULL, inode, 0, 0, &err))) {
1909 if (err)
1910 EXT4_ERROR_INODE(inode,
1911 "error %d reading directory lblock 0", err);
1912 else
1913 ext4_warning(inode->i_sb,
1914 "bad directory (dir #%lu) - no data block",
1915 inode->i_ino);
1916 return 1;
1917 }
1918 de = (struct ext4_dir_entry_2 *) bh->b_data;
1919 de1 = ext4_next_entry(de, sb->s_blocksize);
1920 if (le32_to_cpu(de->inode) != inode->i_ino ||
1921 !le32_to_cpu(de1->inode) ||
1922 strcmp(".", de->name) ||
1923 strcmp("..", de1->name)) {
1924 ext4_warning(inode->i_sb,
1925 "bad directory (dir #%lu) - no `.' or `..'",
1926 inode->i_ino);
1927 brelse(bh);
1928 return 1;
1929 }
1930 offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) +
1931 ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize);
1932 de = ext4_next_entry(de1, sb->s_blocksize);
1933 while (offset < inode->i_size) {
1934 if (!bh ||
1935 (void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
1936 unsigned int lblock;
1937 err = 0;
1938 brelse(bh);
1939 lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb);
1940 bh = ext4_bread(NULL, inode, lblock, 0, &err);
1941 if (!bh) {
1942 if (err)
1943 EXT4_ERROR_INODE(inode,
1944 "error %d reading directory "
1945 "lblock %u", err, lblock);
1946 offset += sb->s_blocksize;
1947 continue;
1948 }
1949 de = (struct ext4_dir_entry_2 *) bh->b_data;
1950 }
1951 if (ext4_check_dir_entry(inode, NULL, de, bh, offset)) {
1952 de = (struct ext4_dir_entry_2 *)(bh->b_data +
1953 sb->s_blocksize);
1954 offset = (offset | (sb->s_blocksize - 1)) + 1;
1955 continue;
1956 }
1957 if (le32_to_cpu(de->inode)) {
1958 brelse(bh);
1959 return 0;
1960 }
1961 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
1962 de = ext4_next_entry(de, sb->s_blocksize);
1963 }
1964 brelse(bh);
1965 return 1;
1966}
1967
1968/* ext4_orphan_add() links an unlinked or truncated inode into a list of
1969 * such inodes, starting at the superblock, in case we crash before the
1970 * file is closed/deleted, or in case the inode truncate spans multiple
1971 * transactions and the last transaction is not recovered after a crash.
1972 *
1973 * At filesystem recovery time, we walk this list deleting unlinked
1974 * inodes and truncating linked inodes in ext4_orphan_cleanup().
1975 */
1976int ext4_orphan_add(handle_t *handle, struct inode *inode)
1977{
1978 struct super_block *sb = inode->i_sb;
1979 struct ext4_iloc iloc;
1980 int err = 0, rc;
1981
1982 if (!ext4_handle_valid(handle))
1983 return 0;
1984
1985 mutex_lock(&EXT4_SB(sb)->s_orphan_lock);
1986 if (!list_empty(&EXT4_I(inode)->i_orphan))
1987 goto out_unlock;
1988
1989 /*
1990 * Orphan handling is only valid for files with data blocks
1991 * being truncated, or files being unlinked. Note that we either
1992 * hold i_mutex, or the inode can not be referenced from outside,
1993 * so i_nlink should not be bumped due to race
1994 */
1995 J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
1996 S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
1997
1998 BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access");
1999 err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
2000 if (err)
2001 goto out_unlock;
2002
2003 err = ext4_reserve_inode_write(handle, inode, &iloc);
2004 if (err)
2005 goto out_unlock;
2006 /*
2007 * Due to previous errors inode may be already a part of on-disk
2008 * orphan list. If so skip on-disk list modification.
2009 */
2010 if (NEXT_ORPHAN(inode) && NEXT_ORPHAN(inode) <=
2011 (le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count)))
2012 goto mem_insert;
2013
2014 /* Insert this inode at the head of the on-disk orphan list... */
2015 NEXT_ORPHAN(inode) = le32_to_cpu(EXT4_SB(sb)->s_es->s_last_orphan);
2016 EXT4_SB(sb)->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
2017 err = ext4_handle_dirty_metadata(handle, NULL, EXT4_SB(sb)->s_sbh);
2018 rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
2019 if (!err)
2020 err = rc;
2021
2022 /* Only add to the head of the in-memory list if all the
2023 * previous operations succeeded. If the orphan_add is going to
2024 * fail (possibly taking the journal offline), we can't risk
2025 * leaving the inode on the orphan list: stray orphan-list
2026 * entries can cause panics at unmount time.
2027 *
2028 * This is safe: on error we're going to ignore the orphan list
2029 * anyway on the next recovery. */
2030mem_insert:
2031 if (!err)
2032 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2033
2034 jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
2035 jbd_debug(4, "orphan inode %lu will point to %d\n",
2036 inode->i_ino, NEXT_ORPHAN(inode));
2037out_unlock:
2038 mutex_unlock(&EXT4_SB(sb)->s_orphan_lock);
2039 ext4_std_error(inode->i_sb, err);
2040 return err;
2041}
2042
2043/*
2044 * ext4_orphan_del() removes an unlinked or truncated inode from the list
2045 * of such inodes stored on disk, because it is finally being cleaned up.
2046 */
2047int ext4_orphan_del(handle_t *handle, struct inode *inode)
2048{
2049 struct list_head *prev;
2050 struct ext4_inode_info *ei = EXT4_I(inode);
2051 struct ext4_sb_info *sbi;
2052 __u32 ino_next;
2053 struct ext4_iloc iloc;
2054 int err = 0;
2055
2056 /* ext4_handle_valid() assumes a valid handle_t pointer */
2057 if (handle && !ext4_handle_valid(handle))
2058 return 0;
2059
2060 mutex_lock(&EXT4_SB(inode->i_sb)->s_orphan_lock);
2061 if (list_empty(&ei->i_orphan))
2062 goto out;
2063
2064 ino_next = NEXT_ORPHAN(inode);
2065 prev = ei->i_orphan.prev;
2066 sbi = EXT4_SB(inode->i_sb);
2067
2068 jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
2069
2070 list_del_init(&ei->i_orphan);
2071
2072 /* If we're on an error path, we may not have a valid
2073 * transaction handle with which to update the orphan list on
2074 * disk, but we still need to remove the inode from the linked
2075 * list in memory. */
2076 if (sbi->s_journal && !handle)
2077 goto out;
2078
2079 err = ext4_reserve_inode_write(handle, inode, &iloc);
2080 if (err)
2081 goto out_err;
2082
2083 if (prev == &sbi->s_orphan) {
2084 jbd_debug(4, "superblock will point to %u\n", ino_next);
2085 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2086 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2087 if (err)
2088 goto out_brelse;
2089 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
2090 err = ext4_handle_dirty_metadata(handle, NULL, sbi->s_sbh);
2091 } else {
2092 struct ext4_iloc iloc2;
2093 struct inode *i_prev =
2094 &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
2095
2096 jbd_debug(4, "orphan inode %lu will point to %u\n",
2097 i_prev->i_ino, ino_next);
2098 err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
2099 if (err)
2100 goto out_brelse;
2101 NEXT_ORPHAN(i_prev) = ino_next;
2102 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
2103 }
2104 if (err)
2105 goto out_brelse;
2106 NEXT_ORPHAN(inode) = 0;
2107 err = ext4_mark_iloc_dirty(handle, inode, &iloc);
2108
2109out_err:
2110 ext4_std_error(inode->i_sb, err);
2111out:
2112 mutex_unlock(&EXT4_SB(inode->i_sb)->s_orphan_lock);
2113 return err;
2114
2115out_brelse:
2116 brelse(iloc.bh);
2117 goto out_err;
2118}
2119
2120static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
2121{
2122 int retval;
2123 struct inode *inode;
2124 struct buffer_head *bh;
2125 struct ext4_dir_entry_2 *de;
2126 handle_t *handle;
2127
2128 /* Initialize quotas before so that eventual writes go in
2129 * separate transaction */
2130 dquot_initialize(dir);
2131 dquot_initialize(dentry->d_inode);
2132
2133 handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb));
2134 if (IS_ERR(handle))
2135 return PTR_ERR(handle);
2136
2137 retval = -ENOENT;
2138 bh = ext4_find_entry(dir, &dentry->d_name, &de);
2139 if (!bh)
2140 goto end_rmdir;
2141
2142 if (IS_DIRSYNC(dir))
2143 ext4_handle_sync(handle);
2144
2145 inode = dentry->d_inode;
2146
2147 retval = -EIO;
2148 if (le32_to_cpu(de->inode) != inode->i_ino)
2149 goto end_rmdir;
2150
2151 retval = -ENOTEMPTY;
2152 if (!empty_dir(inode))
2153 goto end_rmdir;
2154
2155 retval = ext4_delete_entry(handle, dir, de, bh);
2156 if (retval)
2157 goto end_rmdir;
2158 if (!EXT4_DIR_LINK_EMPTY(inode))
2159 ext4_warning(inode->i_sb,
2160 "empty directory has too many links (%d)",
2161 inode->i_nlink);
2162 inode->i_version++;
2163 clear_nlink(inode);
2164 /* There's no need to set i_disksize: the fact that i_nlink is
2165 * zero will ensure that the right thing happens during any
2166 * recovery. */
2167 inode->i_size = 0;
2168 ext4_orphan_add(handle, inode);
2169 inode->i_ctime = dir->i_ctime = dir->i_mtime = ext4_current_time(inode);
2170 ext4_mark_inode_dirty(handle, inode);
2171 ext4_dec_count(handle, dir);
2172 ext4_update_dx_flag(dir);
2173 ext4_mark_inode_dirty(handle, dir);
2174
2175end_rmdir:
2176 ext4_journal_stop(handle);
2177 brelse(bh);
2178 return retval;
2179}
2180
2181static int ext4_unlink(struct inode *dir, struct dentry *dentry)
2182{
2183 int retval;
2184 struct inode *inode;
2185 struct buffer_head *bh;
2186 struct ext4_dir_entry_2 *de;
2187 handle_t *handle;
2188
2189 trace_ext4_unlink_enter(dir, dentry);
2190 /* Initialize quotas before so that eventual writes go
2191 * in separate transaction */
2192 dquot_initialize(dir);
2193 dquot_initialize(dentry->d_inode);
2194
2195 handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb));
2196 if (IS_ERR(handle))
2197 return PTR_ERR(handle);
2198
2199 if (IS_DIRSYNC(dir))
2200 ext4_handle_sync(handle);
2201
2202 retval = -ENOENT;
2203 bh = ext4_find_entry(dir, &dentry->d_name, &de);
2204 if (!bh)
2205 goto end_unlink;
2206
2207 inode = dentry->d_inode;
2208
2209 retval = -EIO;
2210 if (le32_to_cpu(de->inode) != inode->i_ino)
2211 goto end_unlink;
2212
2213 if (!inode->i_nlink) {
2214 ext4_warning(inode->i_sb,
2215 "Deleting nonexistent file (%lu), %d",
2216 inode->i_ino, inode->i_nlink);
2217 inode->i_nlink = 1;
2218 }
2219 retval = ext4_delete_entry(handle, dir, de, bh);
2220 if (retval)
2221 goto end_unlink;
2222 dir->i_ctime = dir->i_mtime = ext4_current_time(dir);
2223 ext4_update_dx_flag(dir);
2224 ext4_mark_inode_dirty(handle, dir);
2225 drop_nlink(inode);
2226 if (!inode->i_nlink)
2227 ext4_orphan_add(handle, inode);
2228 inode->i_ctime = ext4_current_time(inode);
2229 ext4_mark_inode_dirty(handle, inode);
2230 retval = 0;
2231
2232end_unlink:
2233 ext4_journal_stop(handle);
2234 brelse(bh);
2235 trace_ext4_unlink_exit(dentry, retval);
2236 return retval;
2237}
2238
2239static int ext4_symlink(struct inode *dir,
2240 struct dentry *dentry, const char *symname)
2241{
2242 handle_t *handle;
2243 struct inode *inode;
2244 int l, err, retries = 0;
2245 int credits;
2246
2247 l = strlen(symname)+1;
2248 if (l > dir->i_sb->s_blocksize)
2249 return -ENAMETOOLONG;
2250
2251 dquot_initialize(dir);
2252
2253 if (l > EXT4_N_BLOCKS * 4) {
2254 /*
2255 * For non-fast symlinks, we just allocate inode and put it on
2256 * orphan list in the first transaction => we need bitmap,
2257 * group descriptor, sb, inode block, quota blocks, and
2258 * possibly selinux xattr blocks.
2259 */
2260 credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
2261 EXT4_XATTR_TRANS_BLOCKS;
2262 } else {
2263 /*
2264 * Fast symlink. We have to add entry to directory
2265 * (EXT4_DATA_TRANS_BLOCKS + EXT4_INDEX_EXTRA_TRANS_BLOCKS),
2266 * allocate new inode (bitmap, group descriptor, inode block,
2267 * quota blocks, sb is already counted in previous macros).
2268 */
2269 credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2270 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
2271 EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb);
2272 }
2273retry:
2274 handle = ext4_journal_start(dir, credits);
2275 if (IS_ERR(handle))
2276 return PTR_ERR(handle);
2277
2278 if (IS_DIRSYNC(dir))
2279 ext4_handle_sync(handle);
2280
2281 inode = ext4_new_inode(handle, dir, S_IFLNK|S_IRWXUGO,
2282 &dentry->d_name, 0);
2283 err = PTR_ERR(inode);
2284 if (IS_ERR(inode))
2285 goto out_stop;
2286
2287 if (l > EXT4_N_BLOCKS * 4) {
2288 inode->i_op = &ext4_symlink_inode_operations;
2289 ext4_set_aops(inode);
2290 /*
2291 * We cannot call page_symlink() with transaction started
2292 * because it calls into ext4_write_begin() which can wait
2293 * for transaction commit if we are running out of space
2294 * and thus we deadlock. So we have to stop transaction now
2295 * and restart it when symlink contents is written.
2296 *
2297 * To keep fs consistent in case of crash, we have to put inode
2298 * to orphan list in the mean time.
2299 */
2300 drop_nlink(inode);
2301 err = ext4_orphan_add(handle, inode);
2302 ext4_journal_stop(handle);
2303 if (err)
2304 goto err_drop_inode;
2305 err = __page_symlink(inode, symname, l, 1);
2306 if (err)
2307 goto err_drop_inode;
2308 /*
2309 * Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS
2310 * + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified
2311 */
2312 handle = ext4_journal_start(dir,
2313 EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2314 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1);
2315 if (IS_ERR(handle)) {
2316 err = PTR_ERR(handle);
2317 goto err_drop_inode;
2318 }
2319 inc_nlink(inode);
2320 err = ext4_orphan_del(handle, inode);
2321 if (err) {
2322 ext4_journal_stop(handle);
2323 clear_nlink(inode);
2324 goto err_drop_inode;
2325 }
2326 } else {
2327 /* clear the extent format for fast symlink */
2328 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
2329 inode->i_op = &ext4_fast_symlink_inode_operations;
2330 memcpy((char *)&EXT4_I(inode)->i_data, symname, l);
2331 inode->i_size = l-1;
2332 }
2333 EXT4_I(inode)->i_disksize = inode->i_size;
2334 err = ext4_add_nondir(handle, dentry, inode);
2335out_stop:
2336 ext4_journal_stop(handle);
2337 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2338 goto retry;
2339 return err;
2340err_drop_inode:
2341 unlock_new_inode(inode);
2342 iput(inode);
2343 return err;
2344}
2345
2346static int ext4_link(struct dentry *old_dentry,
2347 struct inode *dir, struct dentry *dentry)
2348{
2349 handle_t *handle;
2350 struct inode *inode = old_dentry->d_inode;
2351 int err, retries = 0;
2352
2353 if (inode->i_nlink >= EXT4_LINK_MAX)
2354 return -EMLINK;
2355
2356 dquot_initialize(dir);
2357
2358retry:
2359 handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2360 EXT4_INDEX_EXTRA_TRANS_BLOCKS);
2361 if (IS_ERR(handle))
2362 return PTR_ERR(handle);
2363
2364 if (IS_DIRSYNC(dir))
2365 ext4_handle_sync(handle);
2366
2367 inode->i_ctime = ext4_current_time(inode);
2368 ext4_inc_count(handle, inode);
2369 ihold(inode);
2370
2371 err = ext4_add_entry(handle, dentry, inode);
2372 if (!err) {
2373 ext4_mark_inode_dirty(handle, inode);
2374 d_instantiate(dentry, inode);
2375 } else {
2376 drop_nlink(inode);
2377 iput(inode);
2378 }
2379 ext4_journal_stop(handle);
2380 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2381 goto retry;
2382 return err;
2383}
2384
2385#define PARENT_INO(buffer, size) \
2386 (ext4_next_entry((struct ext4_dir_entry_2 *)(buffer), size)->inode)
2387
2388/*
2389 * Anybody can rename anything with this: the permission checks are left to the
2390 * higher-level routines.
2391 */
2392static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
2393 struct inode *new_dir, struct dentry *new_dentry)
2394{
2395 handle_t *handle;
2396 struct inode *old_inode, *new_inode;
2397 struct buffer_head *old_bh, *new_bh, *dir_bh;
2398 struct ext4_dir_entry_2 *old_de, *new_de;
2399 int retval, force_da_alloc = 0;
2400
2401 dquot_initialize(old_dir);
2402 dquot_initialize(new_dir);
2403
2404 old_bh = new_bh = dir_bh = NULL;
2405
2406 /* Initialize quotas before so that eventual writes go
2407 * in separate transaction */
2408 if (new_dentry->d_inode)
2409 dquot_initialize(new_dentry->d_inode);
2410 handle = ext4_journal_start(old_dir, 2 *
2411 EXT4_DATA_TRANS_BLOCKS(old_dir->i_sb) +
2412 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
2413 if (IS_ERR(handle))
2414 return PTR_ERR(handle);
2415
2416 if (IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir))
2417 ext4_handle_sync(handle);
2418
2419 old_bh = ext4_find_entry(old_dir, &old_dentry->d_name, &old_de);
2420 /*
2421 * Check for inode number is _not_ due to possible IO errors.
2422 * We might rmdir the source, keep it as pwd of some process
2423 * and merrily kill the link to whatever was created under the
2424 * same name. Goodbye sticky bit ;-<
2425 */
2426 old_inode = old_dentry->d_inode;
2427 retval = -ENOENT;
2428 if (!old_bh || le32_to_cpu(old_de->inode) != old_inode->i_ino)
2429 goto end_rename;
2430
2431 new_inode = new_dentry->d_inode;
2432 new_bh = ext4_find_entry(new_dir, &new_dentry->d_name, &new_de);
2433 if (new_bh) {
2434 if (!new_inode) {
2435 brelse(new_bh);
2436 new_bh = NULL;
2437 }
2438 }
2439 if (S_ISDIR(old_inode->i_mode)) {
2440 if (new_inode) {
2441 retval = -ENOTEMPTY;
2442 if (!empty_dir(new_inode))
2443 goto end_rename;
2444 }
2445 retval = -EIO;
2446 dir_bh = ext4_bread(handle, old_inode, 0, 0, &retval);
2447 if (!dir_bh)
2448 goto end_rename;
2449 if (le32_to_cpu(PARENT_INO(dir_bh->b_data,
2450 old_dir->i_sb->s_blocksize)) != old_dir->i_ino)
2451 goto end_rename;
2452 retval = -EMLINK;
2453 if (!new_inode && new_dir != old_dir &&
2454 EXT4_DIR_LINK_MAX(new_dir))
2455 goto end_rename;
2456 BUFFER_TRACE(dir_bh, "get_write_access");
2457 retval = ext4_journal_get_write_access(handle, dir_bh);
2458 if (retval)
2459 goto end_rename;
2460 }
2461 if (!new_bh) {
2462 retval = ext4_add_entry(handle, new_dentry, old_inode);
2463 if (retval)
2464 goto end_rename;
2465 } else {
2466 BUFFER_TRACE(new_bh, "get write access");
2467 retval = ext4_journal_get_write_access(handle, new_bh);
2468 if (retval)
2469 goto end_rename;
2470 new_de->inode = cpu_to_le32(old_inode->i_ino);
2471 if (EXT4_HAS_INCOMPAT_FEATURE(new_dir->i_sb,
2472 EXT4_FEATURE_INCOMPAT_FILETYPE))
2473 new_de->file_type = old_de->file_type;
2474 new_dir->i_version++;
2475 new_dir->i_ctime = new_dir->i_mtime =
2476 ext4_current_time(new_dir);
2477 ext4_mark_inode_dirty(handle, new_dir);
2478 BUFFER_TRACE(new_bh, "call ext4_handle_dirty_metadata");
2479 retval = ext4_handle_dirty_metadata(handle, new_dir, new_bh);
2480 if (unlikely(retval)) {
2481 ext4_std_error(new_dir->i_sb, retval);
2482 goto end_rename;
2483 }
2484 brelse(new_bh);
2485 new_bh = NULL;
2486 }
2487
2488 /*
2489 * Like most other Unix systems, set the ctime for inodes on a
2490 * rename.
2491 */
2492 old_inode->i_ctime = ext4_current_time(old_inode);
2493 ext4_mark_inode_dirty(handle, old_inode);
2494
2495 /*
2496 * ok, that's it
2497 */
2498 if (le32_to_cpu(old_de->inode) != old_inode->i_ino ||
2499 old_de->name_len != old_dentry->d_name.len ||
2500 strncmp(old_de->name, old_dentry->d_name.name, old_de->name_len) ||
2501 (retval = ext4_delete_entry(handle, old_dir,
2502 old_de, old_bh)) == -ENOENT) {
2503 /* old_de could have moved from under us during htree split, so
2504 * make sure that we are deleting the right entry. We might
2505 * also be pointing to a stale entry in the unused part of
2506 * old_bh so just checking inum and the name isn't enough. */
2507 struct buffer_head *old_bh2;
2508 struct ext4_dir_entry_2 *old_de2;
2509
2510 old_bh2 = ext4_find_entry(old_dir, &old_dentry->d_name, &old_de2);
2511 if (old_bh2) {
2512 retval = ext4_delete_entry(handle, old_dir,
2513 old_de2, old_bh2);
2514 brelse(old_bh2);
2515 }
2516 }
2517 if (retval) {
2518 ext4_warning(old_dir->i_sb,
2519 "Deleting old file (%lu), %d, error=%d",
2520 old_dir->i_ino, old_dir->i_nlink, retval);
2521 }
2522
2523 if (new_inode) {
2524 ext4_dec_count(handle, new_inode);
2525 new_inode->i_ctime = ext4_current_time(new_inode);
2526 }
2527 old_dir->i_ctime = old_dir->i_mtime = ext4_current_time(old_dir);
2528 ext4_update_dx_flag(old_dir);
2529 if (dir_bh) {
2530 PARENT_INO(dir_bh->b_data, new_dir->i_sb->s_blocksize) =
2531 cpu_to_le32(new_dir->i_ino);
2532 BUFFER_TRACE(dir_bh, "call ext4_handle_dirty_metadata");
2533 retval = ext4_handle_dirty_metadata(handle, old_dir, dir_bh);
2534 if (retval) {
2535 ext4_std_error(old_dir->i_sb, retval);
2536 goto end_rename;
2537 }
2538 ext4_dec_count(handle, old_dir);
2539 if (new_inode) {
2540 /* checked empty_dir above, can't have another parent,
2541 * ext4_dec_count() won't work for many-linked dirs */
2542 new_inode->i_nlink = 0;
2543 } else {
2544 ext4_inc_count(handle, new_dir);
2545 ext4_update_dx_flag(new_dir);
2546 ext4_mark_inode_dirty(handle, new_dir);
2547 }
2548 }
2549 ext4_mark_inode_dirty(handle, old_dir);
2550 if (new_inode) {
2551 ext4_mark_inode_dirty(handle, new_inode);
2552 if (!new_inode->i_nlink)
2553 ext4_orphan_add(handle, new_inode);
2554 if (!test_opt(new_dir->i_sb, NO_AUTO_DA_ALLOC))
2555 force_da_alloc = 1;
2556 }
2557 retval = 0;
2558
2559end_rename:
2560 brelse(dir_bh);
2561 brelse(old_bh);
2562 brelse(new_bh);
2563 ext4_journal_stop(handle);
2564 if (retval == 0 && force_da_alloc)
2565 ext4_alloc_da_blocks(old_inode);
2566 return retval;
2567}
2568
2569/*
2570 * directories can handle most operations...
2571 */
2572const struct inode_operations ext4_dir_inode_operations = {
2573 .create = ext4_create,
2574 .lookup = ext4_lookup,
2575 .link = ext4_link,
2576 .unlink = ext4_unlink,
2577 .symlink = ext4_symlink,
2578 .mkdir = ext4_mkdir,
2579 .rmdir = ext4_rmdir,
2580 .mknod = ext4_mknod,
2581 .rename = ext4_rename,
2582 .setattr = ext4_setattr,
2583#ifdef CONFIG_EXT4_FS_XATTR
2584 .setxattr = generic_setxattr,
2585 .getxattr = generic_getxattr,
2586 .listxattr = ext4_listxattr,
2587 .removexattr = generic_removexattr,
2588#endif
2589 .get_acl = ext4_get_acl,
2590 .fiemap = ext4_fiemap,
2591};
2592
2593const struct inode_operations ext4_special_inode_operations = {
2594 .setattr = ext4_setattr,
2595#ifdef CONFIG_EXT4_FS_XATTR
2596 .setxattr = generic_setxattr,
2597 .getxattr = generic_getxattr,
2598 .listxattr = ext4_listxattr,
2599 .removexattr = generic_removexattr,
2600#endif
2601 .get_acl = ext4_get_acl,
2602};
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
51static 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 = 0;
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, &err);
66 if (!bh)
67 return ERR_PTR(err);
68 inode->i_size += inode->i_sb->s_blocksize;
69 EXT4_I(inode)->i_disksize = inode->i_size;
70 err = ext4_journal_get_write_access(handle, bh);
71 if (err) {
72 brelse(bh);
73 ext4_std_error(inode->i_sb, err);
74 return ERR_PTR(err);
75 }
76 return bh;
77}
78
79static int ext4_dx_csum_verify(struct inode *inode,
80 struct ext4_dir_entry *dirent);
81
82typedef enum {
83 EITHER, INDEX, DIRENT
84} dirblock_type_t;
85
86#define ext4_read_dirblock(inode, block, type) \
87 __ext4_read_dirblock((inode), (block), (type), __LINE__)
88
89static struct buffer_head *__ext4_read_dirblock(struct inode *inode,
90 ext4_lblk_t block,
91 dirblock_type_t type,
92 unsigned int line)
93{
94 struct buffer_head *bh;
95 struct ext4_dir_entry *dirent;
96 int err = 0, is_dx_block = 0;
97
98 bh = ext4_bread(NULL, inode, block, 0, &err);
99 if (!bh) {
100 if (err == 0) {
101 ext4_error_inode(inode, __func__, line, block,
102 "Directory hole found");
103 return ERR_PTR(-EIO);
104 }
105 __ext4_warning(inode->i_sb, __func__, line,
106 "error reading directory block "
107 "(ino %lu, block %lu)", inode->i_ino,
108 (unsigned long) block);
109 return ERR_PTR(err);
110 }
111 dirent = (struct ext4_dir_entry *) bh->b_data;
112 /* Determine whether or not we have an index block */
113 if (is_dx(inode)) {
114 if (block == 0)
115 is_dx_block = 1;
116 else if (ext4_rec_len_from_disk(dirent->rec_len,
117 inode->i_sb->s_blocksize) ==
118 inode->i_sb->s_blocksize)
119 is_dx_block = 1;
120 }
121 if (!is_dx_block && type == INDEX) {
122 ext4_error_inode(inode, __func__, line, block,
123 "directory leaf block found instead of index block");
124 return ERR_PTR(-EIO);
125 }
126 if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
127 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) ||
128 buffer_verified(bh))
129 return bh;
130
131 /*
132 * An empty leaf block can get mistaken for a index block; for
133 * this reason, we can only check the index checksum when the
134 * caller is sure it should be an index block.
135 */
136 if (is_dx_block && type == INDEX) {
137 if (ext4_dx_csum_verify(inode, dirent))
138 set_buffer_verified(bh);
139 else {
140 ext4_error_inode(inode, __func__, line, block,
141 "Directory index failed checksum");
142 brelse(bh);
143 return ERR_PTR(-EIO);
144 }
145 }
146 if (!is_dx_block) {
147 if (ext4_dirent_csum_verify(inode, dirent))
148 set_buffer_verified(bh);
149 else {
150 ext4_error_inode(inode, __func__, line, block,
151 "Directory block failed checksum");
152 brelse(bh);
153 return ERR_PTR(-EIO);
154 }
155 }
156 return bh;
157}
158
159#ifndef assert
160#define assert(test) J_ASSERT(test)
161#endif
162
163#ifdef DX_DEBUG
164#define dxtrace(command) command
165#else
166#define dxtrace(command)
167#endif
168
169struct fake_dirent
170{
171 __le32 inode;
172 __le16 rec_len;
173 u8 name_len;
174 u8 file_type;
175};
176
177struct dx_countlimit
178{
179 __le16 limit;
180 __le16 count;
181};
182
183struct dx_entry
184{
185 __le32 hash;
186 __le32 block;
187};
188
189/*
190 * dx_root_info is laid out so that if it should somehow get overlaid by a
191 * dirent the two low bits of the hash version will be zero. Therefore, the
192 * hash version mod 4 should never be 0. Sincerely, the paranoia department.
193 */
194
195struct dx_root
196{
197 struct fake_dirent dot;
198 char dot_name[4];
199 struct fake_dirent dotdot;
200 char dotdot_name[4];
201 struct dx_root_info
202 {
203 __le32 reserved_zero;
204 u8 hash_version;
205 u8 info_length; /* 8 */
206 u8 indirect_levels;
207 u8 unused_flags;
208 }
209 info;
210 struct dx_entry entries[0];
211};
212
213struct dx_node
214{
215 struct fake_dirent fake;
216 struct dx_entry entries[0];
217};
218
219
220struct dx_frame
221{
222 struct buffer_head *bh;
223 struct dx_entry *entries;
224 struct dx_entry *at;
225};
226
227struct dx_map_entry
228{
229 u32 hash;
230 u16 offs;
231 u16 size;
232};
233
234/*
235 * This goes at the end of each htree block.
236 */
237struct dx_tail {
238 u32 dt_reserved;
239 __le32 dt_checksum; /* crc32c(uuid+inum+dirblock) */
240};
241
242static inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
243static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
244static inline unsigned dx_get_hash(struct dx_entry *entry);
245static void dx_set_hash(struct dx_entry *entry, unsigned value);
246static unsigned dx_get_count(struct dx_entry *entries);
247static unsigned dx_get_limit(struct dx_entry *entries);
248static void dx_set_count(struct dx_entry *entries, unsigned value);
249static void dx_set_limit(struct dx_entry *entries, unsigned value);
250static unsigned dx_root_limit(struct inode *dir, unsigned infosize);
251static unsigned dx_node_limit(struct inode *dir);
252static struct dx_frame *dx_probe(const struct qstr *d_name,
253 struct inode *dir,
254 struct dx_hash_info *hinfo,
255 struct dx_frame *frame,
256 int *err);
257static void dx_release(struct dx_frame *frames);
258static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize,
259 struct dx_hash_info *hinfo, struct dx_map_entry map[]);
260static void dx_sort_map(struct dx_map_entry *map, unsigned count);
261static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to,
262 struct dx_map_entry *offsets, int count, unsigned blocksize);
263static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize);
264static void dx_insert_block(struct dx_frame *frame,
265 u32 hash, ext4_lblk_t block);
266static int ext4_htree_next_block(struct inode *dir, __u32 hash,
267 struct dx_frame *frame,
268 struct dx_frame *frames,
269 __u32 *start_hash);
270static 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 int *err);
274static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
275 struct inode *inode);
276
277/* checksumming functions */
278void initialize_dirent_tail(struct ext4_dir_entry_tail *t,
279 unsigned int blocksize)
280{
281 memset(t, 0, sizeof(struct ext4_dir_entry_tail));
282 t->det_rec_len = ext4_rec_len_to_disk(
283 sizeof(struct ext4_dir_entry_tail), blocksize);
284 t->det_reserved_ft = EXT4_FT_DIR_CSUM;
285}
286
287/* Walk through a dirent block to find a checksum "dirent" at the tail */
288static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode,
289 struct ext4_dir_entry *de)
290{
291 struct ext4_dir_entry_tail *t;
292
293#ifdef PARANOID
294 struct ext4_dir_entry *d, *top;
295
296 d = de;
297 top = (struct ext4_dir_entry *)(((void *)de) +
298 (EXT4_BLOCK_SIZE(inode->i_sb) -
299 sizeof(struct ext4_dir_entry_tail)));
300 while (d < top && d->rec_len)
301 d = (struct ext4_dir_entry *)(((void *)d) +
302 le16_to_cpu(d->rec_len));
303
304 if (d != top)
305 return NULL;
306
307 t = (struct ext4_dir_entry_tail *)d;
308#else
309 t = EXT4_DIRENT_TAIL(de, EXT4_BLOCK_SIZE(inode->i_sb));
310#endif
311
312 if (t->det_reserved_zero1 ||
313 le16_to_cpu(t->det_rec_len) != sizeof(struct ext4_dir_entry_tail) ||
314 t->det_reserved_zero2 ||
315 t->det_reserved_ft != EXT4_FT_DIR_CSUM)
316 return NULL;
317
318 return t;
319}
320
321static __le32 ext4_dirent_csum(struct inode *inode,
322 struct ext4_dir_entry *dirent, int size)
323{
324 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
325 struct ext4_inode_info *ei = EXT4_I(inode);
326 __u32 csum;
327
328 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
329 return cpu_to_le32(csum);
330}
331
332static void warn_no_space_for_csum(struct inode *inode)
333{
334 ext4_warning(inode->i_sb, "no space in directory inode %lu leaf for "
335 "checksum. Please run e2fsck -D.", inode->i_ino);
336}
337
338int ext4_dirent_csum_verify(struct inode *inode, struct ext4_dir_entry *dirent)
339{
340 struct ext4_dir_entry_tail *t;
341
342 if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
343 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
344 return 1;
345
346 t = get_dirent_tail(inode, dirent);
347 if (!t) {
348 warn_no_space_for_csum(inode);
349 return 0;
350 }
351
352 if (t->det_checksum != ext4_dirent_csum(inode, dirent,
353 (void *)t - (void *)dirent))
354 return 0;
355
356 return 1;
357}
358
359static void ext4_dirent_csum_set(struct inode *inode,
360 struct ext4_dir_entry *dirent)
361{
362 struct ext4_dir_entry_tail *t;
363
364 if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
365 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
366 return;
367
368 t = get_dirent_tail(inode, dirent);
369 if (!t) {
370 warn_no_space_for_csum(inode);
371 return;
372 }
373
374 t->det_checksum = ext4_dirent_csum(inode, dirent,
375 (void *)t - (void *)dirent);
376}
377
378int ext4_handle_dirty_dirent_node(handle_t *handle,
379 struct inode *inode,
380 struct buffer_head *bh)
381{
382 ext4_dirent_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
383 return ext4_handle_dirty_metadata(handle, inode, bh);
384}
385
386static struct dx_countlimit *get_dx_countlimit(struct inode *inode,
387 struct ext4_dir_entry *dirent,
388 int *offset)
389{
390 struct ext4_dir_entry *dp;
391 struct dx_root_info *root;
392 int count_offset;
393
394 if (le16_to_cpu(dirent->rec_len) == EXT4_BLOCK_SIZE(inode->i_sb))
395 count_offset = 8;
396 else if (le16_to_cpu(dirent->rec_len) == 12) {
397 dp = (struct ext4_dir_entry *)(((void *)dirent) + 12);
398 if (le16_to_cpu(dp->rec_len) !=
399 EXT4_BLOCK_SIZE(inode->i_sb) - 12)
400 return NULL;
401 root = (struct dx_root_info *)(((void *)dp + 12));
402 if (root->reserved_zero ||
403 root->info_length != sizeof(struct dx_root_info))
404 return NULL;
405 count_offset = 32;
406 } else
407 return NULL;
408
409 if (offset)
410 *offset = count_offset;
411 return (struct dx_countlimit *)(((void *)dirent) + count_offset);
412}
413
414static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent,
415 int count_offset, int count, struct dx_tail *t)
416{
417 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
418 struct ext4_inode_info *ei = EXT4_I(inode);
419 __u32 csum;
420 __le32 save_csum;
421 int size;
422
423 size = count_offset + (count * sizeof(struct dx_entry));
424 save_csum = t->dt_checksum;
425 t->dt_checksum = 0;
426 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
427 csum = ext4_chksum(sbi, csum, (__u8 *)t, sizeof(struct dx_tail));
428 t->dt_checksum = save_csum;
429
430 return cpu_to_le32(csum);
431}
432
433static int ext4_dx_csum_verify(struct inode *inode,
434 struct ext4_dir_entry *dirent)
435{
436 struct dx_countlimit *c;
437 struct dx_tail *t;
438 int count_offset, limit, count;
439
440 if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
441 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
442 return 1;
443
444 c = get_dx_countlimit(inode, dirent, &count_offset);
445 if (!c) {
446 EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D.");
447 return 1;
448 }
449 limit = le16_to_cpu(c->limit);
450 count = le16_to_cpu(c->count);
451 if (count_offset + (limit * sizeof(struct dx_entry)) >
452 EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
453 warn_no_space_for_csum(inode);
454 return 1;
455 }
456 t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
457
458 if (t->dt_checksum != ext4_dx_csum(inode, dirent, count_offset,
459 count, t))
460 return 0;
461 return 1;
462}
463
464static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent)
465{
466 struct dx_countlimit *c;
467 struct dx_tail *t;
468 int count_offset, limit, count;
469
470 if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
471 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
472 return;
473
474 c = get_dx_countlimit(inode, dirent, &count_offset);
475 if (!c) {
476 EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D.");
477 return;
478 }
479 limit = le16_to_cpu(c->limit);
480 count = le16_to_cpu(c->count);
481 if (count_offset + (limit * sizeof(struct dx_entry)) >
482 EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
483 warn_no_space_for_csum(inode);
484 return;
485 }
486 t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
487
488 t->dt_checksum = ext4_dx_csum(inode, dirent, count_offset, count, t);
489}
490
491static inline int ext4_handle_dirty_dx_node(handle_t *handle,
492 struct inode *inode,
493 struct buffer_head *bh)
494{
495 ext4_dx_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
496 return ext4_handle_dirty_metadata(handle, inode, bh);
497}
498
499/*
500 * p is at least 6 bytes before the end of page
501 */
502static inline struct ext4_dir_entry_2 *
503ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
504{
505 return (struct ext4_dir_entry_2 *)((char *)p +
506 ext4_rec_len_from_disk(p->rec_len, blocksize));
507}
508
509/*
510 * Future: use high four bits of block for coalesce-on-delete flags
511 * Mask them off for now.
512 */
513
514static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
515{
516 return le32_to_cpu(entry->block) & 0x00ffffff;
517}
518
519static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
520{
521 entry->block = cpu_to_le32(value);
522}
523
524static inline unsigned dx_get_hash(struct dx_entry *entry)
525{
526 return le32_to_cpu(entry->hash);
527}
528
529static inline void dx_set_hash(struct dx_entry *entry, unsigned value)
530{
531 entry->hash = cpu_to_le32(value);
532}
533
534static inline unsigned dx_get_count(struct dx_entry *entries)
535{
536 return le16_to_cpu(((struct dx_countlimit *) entries)->count);
537}
538
539static inline unsigned dx_get_limit(struct dx_entry *entries)
540{
541 return le16_to_cpu(((struct dx_countlimit *) entries)->limit);
542}
543
544static inline void dx_set_count(struct dx_entry *entries, unsigned value)
545{
546 ((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
547}
548
549static inline void dx_set_limit(struct dx_entry *entries, unsigned value)
550{
551 ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
552}
553
554static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
555{
556 unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
557 EXT4_DIR_REC_LEN(2) - infosize;
558
559 if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
560 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
561 entry_space -= sizeof(struct dx_tail);
562 return entry_space / sizeof(struct dx_entry);
563}
564
565static inline unsigned dx_node_limit(struct inode *dir)
566{
567 unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);
568
569 if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
570 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
571 entry_space -= sizeof(struct dx_tail);
572 return entry_space / sizeof(struct dx_entry);
573}
574
575/*
576 * Debug
577 */
578#ifdef DX_DEBUG
579static void dx_show_index(char * label, struct dx_entry *entries)
580{
581 int i, n = dx_get_count (entries);
582 printk(KERN_DEBUG "%s index ", label);
583 for (i = 0; i < n; i++) {
584 printk("%x->%lu ", i ? dx_get_hash(entries + i) :
585 0, (unsigned long)dx_get_block(entries + i));
586 }
587 printk("\n");
588}
589
590struct stats
591{
592 unsigned names;
593 unsigned space;
594 unsigned bcount;
595};
596
597static struct stats dx_show_leaf(struct dx_hash_info *hinfo, struct ext4_dir_entry_2 *de,
598 int size, int show_names)
599{
600 unsigned names = 0, space = 0;
601 char *base = (char *) de;
602 struct dx_hash_info h = *hinfo;
603
604 printk("names: ");
605 while ((char *) de < base + size)
606 {
607 if (de->inode)
608 {
609 if (show_names)
610 {
611 int len = de->name_len;
612 char *name = de->name;
613 while (len--) printk("%c", *name++);
614 ext4fs_dirhash(de->name, de->name_len, &h);
615 printk(":%x.%u ", h.hash,
616 (unsigned) ((char *) de - base));
617 }
618 space += EXT4_DIR_REC_LEN(de->name_len);
619 names++;
620 }
621 de = ext4_next_entry(de, size);
622 }
623 printk("(%i)\n", names);
624 return (struct stats) { names, space, 1 };
625}
626
627struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
628 struct dx_entry *entries, int levels)
629{
630 unsigned blocksize = dir->i_sb->s_blocksize;
631 unsigned count = dx_get_count(entries), names = 0, space = 0, i;
632 unsigned bcount = 0;
633 struct buffer_head *bh;
634 int err;
635 printk("%i indexed blocks...\n", count);
636 for (i = 0; i < count; i++, entries++)
637 {
638 ext4_lblk_t block = dx_get_block(entries);
639 ext4_lblk_t hash = i ? dx_get_hash(entries): 0;
640 u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
641 struct stats stats;
642 printk("%s%3u:%03u hash %8x/%8x ",levels?"":" ", i, block, hash, range);
643 if (!(bh = ext4_bread (NULL,dir, block, 0,&err))) continue;
644 stats = levels?
645 dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
646 dx_show_leaf(hinfo, (struct ext4_dir_entry_2 *) bh->b_data, blocksize, 0);
647 names += stats.names;
648 space += stats.space;
649 bcount += stats.bcount;
650 brelse(bh);
651 }
652 if (bcount)
653 printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n",
654 levels ? "" : " ", names, space/bcount,
655 (space/bcount)*100/blocksize);
656 return (struct stats) { names, space, bcount};
657}
658#endif /* DX_DEBUG */
659
660/*
661 * Probe for a directory leaf block to search.
662 *
663 * dx_probe can return ERR_BAD_DX_DIR, which means there was a format
664 * error in the directory index, and the caller should fall back to
665 * searching the directory normally. The callers of dx_probe **MUST**
666 * check for this error code, and make sure it never gets reflected
667 * back to userspace.
668 */
669static struct dx_frame *
670dx_probe(const struct qstr *d_name, struct inode *dir,
671 struct dx_hash_info *hinfo, struct dx_frame *frame_in, int *err)
672{
673 unsigned count, indirect;
674 struct dx_entry *at, *entries, *p, *q, *m;
675 struct dx_root *root;
676 struct buffer_head *bh;
677 struct dx_frame *frame = frame_in;
678 u32 hash;
679
680 frame->bh = NULL;
681 bh = ext4_read_dirblock(dir, 0, INDEX);
682 if (IS_ERR(bh)) {
683 *err = PTR_ERR(bh);
684 goto fail;
685 }
686 root = (struct dx_root *) bh->b_data;
687 if (root->info.hash_version != DX_HASH_TEA &&
688 root->info.hash_version != DX_HASH_HALF_MD4 &&
689 root->info.hash_version != DX_HASH_LEGACY) {
690 ext4_warning(dir->i_sb, "Unrecognised inode hash code %d",
691 root->info.hash_version);
692 brelse(bh);
693 *err = ERR_BAD_DX_DIR;
694 goto fail;
695 }
696 hinfo->hash_version = root->info.hash_version;
697 if (hinfo->hash_version <= DX_HASH_TEA)
698 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
699 hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
700 if (d_name)
701 ext4fs_dirhash(d_name->name, d_name->len, hinfo);
702 hash = hinfo->hash;
703
704 if (root->info.unused_flags & 1) {
705 ext4_warning(dir->i_sb, "Unimplemented inode hash flags: %#06x",
706 root->info.unused_flags);
707 brelse(bh);
708 *err = ERR_BAD_DX_DIR;
709 goto fail;
710 }
711
712 if ((indirect = root->info.indirect_levels) > 1) {
713 ext4_warning(dir->i_sb, "Unimplemented inode hash depth: %#06x",
714 root->info.indirect_levels);
715 brelse(bh);
716 *err = ERR_BAD_DX_DIR;
717 goto fail;
718 }
719
720 entries = (struct dx_entry *) (((char *)&root->info) +
721 root->info.info_length);
722
723 if (dx_get_limit(entries) != dx_root_limit(dir,
724 root->info.info_length)) {
725 ext4_warning(dir->i_sb, "dx entry: limit != root limit");
726 brelse(bh);
727 *err = ERR_BAD_DX_DIR;
728 goto fail;
729 }
730
731 dxtrace(printk("Look up %x", hash));
732 while (1)
733 {
734 count = dx_get_count(entries);
735 if (!count || count > dx_get_limit(entries)) {
736 ext4_warning(dir->i_sb,
737 "dx entry: no count or count > limit");
738 brelse(bh);
739 *err = ERR_BAD_DX_DIR;
740 goto fail2;
741 }
742
743 p = entries + 1;
744 q = entries + count - 1;
745 while (p <= q)
746 {
747 m = p + (q - p)/2;
748 dxtrace(printk("."));
749 if (dx_get_hash(m) > hash)
750 q = m - 1;
751 else
752 p = m + 1;
753 }
754
755 if (0) // linear search cross check
756 {
757 unsigned n = count - 1;
758 at = entries;
759 while (n--)
760 {
761 dxtrace(printk(","));
762 if (dx_get_hash(++at) > hash)
763 {
764 at--;
765 break;
766 }
767 }
768 assert (at == p - 1);
769 }
770
771 at = p - 1;
772 dxtrace(printk(" %x->%u\n", at == entries? 0: dx_get_hash(at), dx_get_block(at)));
773 frame->bh = bh;
774 frame->entries = entries;
775 frame->at = at;
776 if (!indirect--) return frame;
777 bh = ext4_read_dirblock(dir, dx_get_block(at), INDEX);
778 if (IS_ERR(bh)) {
779 *err = PTR_ERR(bh);
780 goto fail2;
781 }
782 entries = ((struct dx_node *) bh->b_data)->entries;
783
784 if (dx_get_limit(entries) != dx_node_limit (dir)) {
785 ext4_warning(dir->i_sb,
786 "dx entry: limit != node limit");
787 brelse(bh);
788 *err = ERR_BAD_DX_DIR;
789 goto fail2;
790 }
791 frame++;
792 frame->bh = NULL;
793 }
794fail2:
795 while (frame >= frame_in) {
796 brelse(frame->bh);
797 frame--;
798 }
799fail:
800 if (*err == ERR_BAD_DX_DIR)
801 ext4_warning(dir->i_sb,
802 "Corrupt dir inode %lu, running e2fsck is "
803 "recommended.", dir->i_ino);
804 return NULL;
805}
806
807static void dx_release (struct dx_frame *frames)
808{
809 if (frames[0].bh == NULL)
810 return;
811
812 if (((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels)
813 brelse(frames[1].bh);
814 brelse(frames[0].bh);
815}
816
817/*
818 * This function increments the frame pointer to search the next leaf
819 * block, and reads in the necessary intervening nodes if the search
820 * should be necessary. Whether or not the search is necessary is
821 * controlled by the hash parameter. If the hash value is even, then
822 * the search is only continued if the next block starts with that
823 * hash value. This is used if we are searching for a specific file.
824 *
825 * If the hash value is HASH_NB_ALWAYS, then always go to the next block.
826 *
827 * This function returns 1 if the caller should continue to search,
828 * or 0 if it should not. If there is an error reading one of the
829 * index blocks, it will a negative error code.
830 *
831 * If start_hash is non-null, it will be filled in with the starting
832 * hash of the next page.
833 */
834static int ext4_htree_next_block(struct inode *dir, __u32 hash,
835 struct dx_frame *frame,
836 struct dx_frame *frames,
837 __u32 *start_hash)
838{
839 struct dx_frame *p;
840 struct buffer_head *bh;
841 int num_frames = 0;
842 __u32 bhash;
843
844 p = frame;
845 /*
846 * Find the next leaf page by incrementing the frame pointer.
847 * If we run out of entries in the interior node, loop around and
848 * increment pointer in the parent node. When we break out of
849 * this loop, num_frames indicates the number of interior
850 * nodes need to be read.
851 */
852 while (1) {
853 if (++(p->at) < p->entries + dx_get_count(p->entries))
854 break;
855 if (p == frames)
856 return 0;
857 num_frames++;
858 p--;
859 }
860
861 /*
862 * If the hash is 1, then continue only if the next page has a
863 * continuation hash of any value. This is used for readdir
864 * handling. Otherwise, check to see if the hash matches the
865 * desired contiuation hash. If it doesn't, return since
866 * there's no point to read in the successive index pages.
867 */
868 bhash = dx_get_hash(p->at);
869 if (start_hash)
870 *start_hash = bhash;
871 if ((hash & 1) == 0) {
872 if ((bhash & ~1) != hash)
873 return 0;
874 }
875 /*
876 * If the hash is HASH_NB_ALWAYS, we always go to the next
877 * block so no check is necessary
878 */
879 while (num_frames--) {
880 bh = ext4_read_dirblock(dir, dx_get_block(p->at), INDEX);
881 if (IS_ERR(bh))
882 return PTR_ERR(bh);
883 p++;
884 brelse(p->bh);
885 p->bh = bh;
886 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
887 }
888 return 1;
889}
890
891
892/*
893 * This function fills a red-black tree with information from a
894 * directory block. It returns the number directory entries loaded
895 * into the tree. If there is an error it is returned in err.
896 */
897static int htree_dirblock_to_tree(struct file *dir_file,
898 struct inode *dir, ext4_lblk_t block,
899 struct dx_hash_info *hinfo,
900 __u32 start_hash, __u32 start_minor_hash)
901{
902 struct buffer_head *bh;
903 struct ext4_dir_entry_2 *de, *top;
904 int err = 0, count = 0;
905
906 dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
907 (unsigned long)block));
908 bh = ext4_read_dirblock(dir, block, DIRENT);
909 if (IS_ERR(bh))
910 return PTR_ERR(bh);
911
912 de = (struct ext4_dir_entry_2 *) bh->b_data;
913 top = (struct ext4_dir_entry_2 *) ((char *) de +
914 dir->i_sb->s_blocksize -
915 EXT4_DIR_REC_LEN(0));
916 for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) {
917 if (ext4_check_dir_entry(dir, NULL, de, bh,
918 bh->b_data, bh->b_size,
919 (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
920 + ((char *)de - bh->b_data))) {
921 /* silently ignore the rest of the block */
922 break;
923 }
924 ext4fs_dirhash(de->name, de->name_len, hinfo);
925 if ((hinfo->hash < start_hash) ||
926 ((hinfo->hash == start_hash) &&
927 (hinfo->minor_hash < start_minor_hash)))
928 continue;
929 if (de->inode == 0)
930 continue;
931 if ((err = ext4_htree_store_dirent(dir_file,
932 hinfo->hash, hinfo->minor_hash, de)) != 0) {
933 brelse(bh);
934 return err;
935 }
936 count++;
937 }
938 brelse(bh);
939 return count;
940}
941
942
943/*
944 * This function fills a red-black tree with information from a
945 * directory. We start scanning the directory in hash order, starting
946 * at start_hash and start_minor_hash.
947 *
948 * This function returns the number of entries inserted into the tree,
949 * or a negative error code.
950 */
951int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
952 __u32 start_minor_hash, __u32 *next_hash)
953{
954 struct dx_hash_info hinfo;
955 struct ext4_dir_entry_2 *de;
956 struct dx_frame frames[2], *frame;
957 struct inode *dir;
958 ext4_lblk_t block;
959 int count = 0;
960 int ret, err;
961 __u32 hashval;
962
963 dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
964 start_hash, start_minor_hash));
965 dir = file_inode(dir_file);
966 if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) {
967 hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
968 if (hinfo.hash_version <= DX_HASH_TEA)
969 hinfo.hash_version +=
970 EXT4_SB(dir->i_sb)->s_hash_unsigned;
971 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
972 if (ext4_has_inline_data(dir)) {
973 int has_inline_data = 1;
974 count = htree_inlinedir_to_tree(dir_file, dir, 0,
975 &hinfo, start_hash,
976 start_minor_hash,
977 &has_inline_data);
978 if (has_inline_data) {
979 *next_hash = ~0;
980 return count;
981 }
982 }
983 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
984 start_hash, start_minor_hash);
985 *next_hash = ~0;
986 return count;
987 }
988 hinfo.hash = start_hash;
989 hinfo.minor_hash = 0;
990 frame = dx_probe(NULL, dir, &hinfo, frames, &err);
991 if (!frame)
992 return err;
993
994 /* Add '.' and '..' from the htree header */
995 if (!start_hash && !start_minor_hash) {
996 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
997 if ((err = ext4_htree_store_dirent(dir_file, 0, 0, de)) != 0)
998 goto errout;
999 count++;
1000 }
1001 if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
1002 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
1003 de = ext4_next_entry(de, dir->i_sb->s_blocksize);
1004 if ((err = ext4_htree_store_dirent(dir_file, 2, 0, de)) != 0)
1005 goto errout;
1006 count++;
1007 }
1008
1009 while (1) {
1010 block = dx_get_block(frame->at);
1011 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
1012 start_hash, start_minor_hash);
1013 if (ret < 0) {
1014 err = ret;
1015 goto errout;
1016 }
1017 count += ret;
1018 hashval = ~0;
1019 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
1020 frame, frames, &hashval);
1021 *next_hash = hashval;
1022 if (ret < 0) {
1023 err = ret;
1024 goto errout;
1025 }
1026 /*
1027 * Stop if: (a) there are no more entries, or
1028 * (b) we have inserted at least one entry and the
1029 * next hash value is not a continuation
1030 */
1031 if ((ret == 0) ||
1032 (count && ((hashval & 1) == 0)))
1033 break;
1034 }
1035 dx_release(frames);
1036 dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, "
1037 "next hash: %x\n", count, *next_hash));
1038 return count;
1039errout:
1040 dx_release(frames);
1041 return (err);
1042}
1043
1044static inline int search_dirblock(struct buffer_head *bh,
1045 struct inode *dir,
1046 const struct qstr *d_name,
1047 unsigned int offset,
1048 struct ext4_dir_entry_2 **res_dir)
1049{
1050 return search_dir(bh, bh->b_data, dir->i_sb->s_blocksize, dir,
1051 d_name, offset, res_dir);
1052}
1053
1054/*
1055 * Directory block splitting, compacting
1056 */
1057
1058/*
1059 * Create map of hash values, offsets, and sizes, stored at end of block.
1060 * Returns number of entries mapped.
1061 */
1062static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize,
1063 struct dx_hash_info *hinfo,
1064 struct dx_map_entry *map_tail)
1065{
1066 int count = 0;
1067 char *base = (char *) de;
1068 struct dx_hash_info h = *hinfo;
1069
1070 while ((char *) de < base + blocksize) {
1071 if (de->name_len && de->inode) {
1072 ext4fs_dirhash(de->name, de->name_len, &h);
1073 map_tail--;
1074 map_tail->hash = h.hash;
1075 map_tail->offs = ((char *) de - base)>>2;
1076 map_tail->size = le16_to_cpu(de->rec_len);
1077 count++;
1078 cond_resched();
1079 }
1080 /* XXX: do we need to check rec_len == 0 case? -Chris */
1081 de = ext4_next_entry(de, blocksize);
1082 }
1083 return count;
1084}
1085
1086/* Sort map by hash value */
1087static void dx_sort_map (struct dx_map_entry *map, unsigned count)
1088{
1089 struct dx_map_entry *p, *q, *top = map + count - 1;
1090 int more;
1091 /* Combsort until bubble sort doesn't suck */
1092 while (count > 2) {
1093 count = count*10/13;
1094 if (count - 9 < 2) /* 9, 10 -> 11 */
1095 count = 11;
1096 for (p = top, q = p - count; q >= map; p--, q--)
1097 if (p->hash < q->hash)
1098 swap(*p, *q);
1099 }
1100 /* Garden variety bubble sort */
1101 do {
1102 more = 0;
1103 q = top;
1104 while (q-- > map) {
1105 if (q[1].hash >= q[0].hash)
1106 continue;
1107 swap(*(q+1), *q);
1108 more = 1;
1109 }
1110 } while(more);
1111}
1112
1113static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
1114{
1115 struct dx_entry *entries = frame->entries;
1116 struct dx_entry *old = frame->at, *new = old + 1;
1117 int count = dx_get_count(entries);
1118
1119 assert(count < dx_get_limit(entries));
1120 assert(old < entries + count);
1121 memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
1122 dx_set_hash(new, hash);
1123 dx_set_block(new, block);
1124 dx_set_count(entries, count + 1);
1125}
1126
1127/*
1128 * NOTE! unlike strncmp, ext4_match returns 1 for success, 0 for failure.
1129 *
1130 * `len <= EXT4_NAME_LEN' is guaranteed by caller.
1131 * `de != NULL' is guaranteed by caller.
1132 */
1133static inline int ext4_match (int len, const char * const name,
1134 struct ext4_dir_entry_2 * de)
1135{
1136 if (len != de->name_len)
1137 return 0;
1138 if (!de->inode)
1139 return 0;
1140 return !memcmp(name, de->name, len);
1141}
1142
1143/*
1144 * Returns 0 if not found, -1 on failure, and 1 on success
1145 */
1146int search_dir(struct buffer_head *bh,
1147 char *search_buf,
1148 int buf_size,
1149 struct inode *dir,
1150 const struct qstr *d_name,
1151 unsigned int offset,
1152 struct ext4_dir_entry_2 **res_dir)
1153{
1154 struct ext4_dir_entry_2 * de;
1155 char * dlimit;
1156 int de_len;
1157 const char *name = d_name->name;
1158 int namelen = d_name->len;
1159
1160 de = (struct ext4_dir_entry_2 *)search_buf;
1161 dlimit = search_buf + buf_size;
1162 while ((char *) de < dlimit) {
1163 /* this code is executed quadratically often */
1164 /* do minimal checking `by hand' */
1165
1166 if ((char *) de + namelen <= dlimit &&
1167 ext4_match (namelen, name, de)) {
1168 /* found a match - just to be sure, do a full check */
1169 if (ext4_check_dir_entry(dir, NULL, de, bh, bh->b_data,
1170 bh->b_size, offset))
1171 return -1;
1172 *res_dir = de;
1173 return 1;
1174 }
1175 /* prevent looping on a bad block */
1176 de_len = ext4_rec_len_from_disk(de->rec_len,
1177 dir->i_sb->s_blocksize);
1178 if (de_len <= 0)
1179 return -1;
1180 offset += de_len;
1181 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
1182 }
1183 return 0;
1184}
1185
1186static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block,
1187 struct ext4_dir_entry *de)
1188{
1189 struct super_block *sb = dir->i_sb;
1190
1191 if (!is_dx(dir))
1192 return 0;
1193 if (block == 0)
1194 return 1;
1195 if (de->inode == 0 &&
1196 ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) ==
1197 sb->s_blocksize)
1198 return 1;
1199 return 0;
1200}
1201
1202/*
1203 * ext4_find_entry()
1204 *
1205 * finds an entry in the specified directory with the wanted name. It
1206 * returns the cache buffer in which the entry was found, and the entry
1207 * itself (as a parameter - res_dir). It does NOT read the inode of the
1208 * entry - you'll have to do that yourself if you want to.
1209 *
1210 * The returned buffer_head has ->b_count elevated. The caller is expected
1211 * to brelse() it when appropriate.
1212 */
1213static struct buffer_head * ext4_find_entry (struct inode *dir,
1214 const struct qstr *d_name,
1215 struct ext4_dir_entry_2 **res_dir,
1216 int *inlined)
1217{
1218 struct super_block *sb;
1219 struct buffer_head *bh_use[NAMEI_RA_SIZE];
1220 struct buffer_head *bh, *ret = NULL;
1221 ext4_lblk_t start, block, b;
1222 const u8 *name = d_name->name;
1223 int ra_max = 0; /* Number of bh's in the readahead
1224 buffer, bh_use[] */
1225 int ra_ptr = 0; /* Current index into readahead
1226 buffer */
1227 int num = 0;
1228 ext4_lblk_t nblocks;
1229 int i, err;
1230 int namelen;
1231
1232 *res_dir = NULL;
1233 sb = dir->i_sb;
1234 namelen = d_name->len;
1235 if (namelen > EXT4_NAME_LEN)
1236 return NULL;
1237
1238 if (ext4_has_inline_data(dir)) {
1239 int has_inline_data = 1;
1240 ret = ext4_find_inline_entry(dir, d_name, res_dir,
1241 &has_inline_data);
1242 if (has_inline_data) {
1243 if (inlined)
1244 *inlined = 1;
1245 return ret;
1246 }
1247 }
1248
1249 if ((namelen <= 2) && (name[0] == '.') &&
1250 (name[1] == '.' || name[1] == '\0')) {
1251 /*
1252 * "." or ".." will only be in the first block
1253 * NFS may look up ".."; "." should be handled by the VFS
1254 */
1255 block = start = 0;
1256 nblocks = 1;
1257 goto restart;
1258 }
1259 if (is_dx(dir)) {
1260 bh = ext4_dx_find_entry(dir, d_name, res_dir, &err);
1261 /*
1262 * On success, or if the error was file not found,
1263 * return. Otherwise, fall back to doing a search the
1264 * old fashioned way.
1265 */
1266 if (bh || (err != ERR_BAD_DX_DIR))
1267 return bh;
1268 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
1269 "falling back\n"));
1270 }
1271 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1272 start = EXT4_I(dir)->i_dir_start_lookup;
1273 if (start >= nblocks)
1274 start = 0;
1275 block = start;
1276restart:
1277 do {
1278 /*
1279 * We deal with the read-ahead logic here.
1280 */
1281 if (ra_ptr >= ra_max) {
1282 /* Refill the readahead buffer */
1283 ra_ptr = 0;
1284 b = block;
1285 for (ra_max = 0; ra_max < NAMEI_RA_SIZE; ra_max++) {
1286 /*
1287 * Terminate if we reach the end of the
1288 * directory and must wrap, or if our
1289 * search has finished at this block.
1290 */
1291 if (b >= nblocks || (num && block == start)) {
1292 bh_use[ra_max] = NULL;
1293 break;
1294 }
1295 num++;
1296 bh = ext4_getblk(NULL, dir, b++, 0, &err);
1297 bh_use[ra_max] = bh;
1298 if (bh)
1299 ll_rw_block(READ | REQ_META | REQ_PRIO,
1300 1, &bh);
1301 }
1302 }
1303 if ((bh = bh_use[ra_ptr++]) == NULL)
1304 goto next;
1305 wait_on_buffer(bh);
1306 if (!buffer_uptodate(bh)) {
1307 /* read error, skip block & hope for the best */
1308 EXT4_ERROR_INODE(dir, "reading directory lblock %lu",
1309 (unsigned long) block);
1310 brelse(bh);
1311 goto next;
1312 }
1313 if (!buffer_verified(bh) &&
1314 !is_dx_internal_node(dir, block,
1315 (struct ext4_dir_entry *)bh->b_data) &&
1316 !ext4_dirent_csum_verify(dir,
1317 (struct ext4_dir_entry *)bh->b_data)) {
1318 EXT4_ERROR_INODE(dir, "checksumming directory "
1319 "block %lu", (unsigned long)block);
1320 brelse(bh);
1321 goto next;
1322 }
1323 set_buffer_verified(bh);
1324 i = search_dirblock(bh, dir, d_name,
1325 block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
1326 if (i == 1) {
1327 EXT4_I(dir)->i_dir_start_lookup = block;
1328 ret = bh;
1329 goto cleanup_and_exit;
1330 } else {
1331 brelse(bh);
1332 if (i < 0)
1333 goto cleanup_and_exit;
1334 }
1335 next:
1336 if (++block >= nblocks)
1337 block = 0;
1338 } while (block != start);
1339
1340 /*
1341 * If the directory has grown while we were searching, then
1342 * search the last part of the directory before giving up.
1343 */
1344 block = nblocks;
1345 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1346 if (block < nblocks) {
1347 start = 0;
1348 goto restart;
1349 }
1350
1351cleanup_and_exit:
1352 /* Clean up the read-ahead blocks */
1353 for (; ra_ptr < ra_max; ra_ptr++)
1354 brelse(bh_use[ra_ptr]);
1355 return ret;
1356}
1357
1358static struct buffer_head * ext4_dx_find_entry(struct inode *dir, const struct qstr *d_name,
1359 struct ext4_dir_entry_2 **res_dir, int *err)
1360{
1361 struct super_block * sb = dir->i_sb;
1362 struct dx_hash_info hinfo;
1363 struct dx_frame frames[2], *frame;
1364 struct buffer_head *bh;
1365 ext4_lblk_t block;
1366 int retval;
1367
1368 if (!(frame = dx_probe(d_name, dir, &hinfo, frames, err)))
1369 return NULL;
1370 do {
1371 block = dx_get_block(frame->at);
1372 bh = ext4_read_dirblock(dir, block, DIRENT);
1373 if (IS_ERR(bh)) {
1374 *err = PTR_ERR(bh);
1375 goto errout;
1376 }
1377 retval = search_dirblock(bh, dir, d_name,
1378 block << EXT4_BLOCK_SIZE_BITS(sb),
1379 res_dir);
1380 if (retval == 1) { /* Success! */
1381 dx_release(frames);
1382 return bh;
1383 }
1384 brelse(bh);
1385 if (retval == -1) {
1386 *err = ERR_BAD_DX_DIR;
1387 goto errout;
1388 }
1389
1390 /* Check to see if we should continue to search */
1391 retval = ext4_htree_next_block(dir, hinfo.hash, frame,
1392 frames, NULL);
1393 if (retval < 0) {
1394 ext4_warning(sb,
1395 "error reading index page in directory #%lu",
1396 dir->i_ino);
1397 *err = retval;
1398 goto errout;
1399 }
1400 } while (retval == 1);
1401
1402 *err = -ENOENT;
1403errout:
1404 dxtrace(printk(KERN_DEBUG "%s not found\n", d_name->name));
1405 dx_release (frames);
1406 return NULL;
1407}
1408
1409static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
1410{
1411 struct inode *inode;
1412 struct ext4_dir_entry_2 *de;
1413 struct buffer_head *bh;
1414
1415 if (dentry->d_name.len > EXT4_NAME_LEN)
1416 return ERR_PTR(-ENAMETOOLONG);
1417
1418 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
1419 inode = NULL;
1420 if (bh) {
1421 __u32 ino = le32_to_cpu(de->inode);
1422 brelse(bh);
1423 if (!ext4_valid_inum(dir->i_sb, ino)) {
1424 EXT4_ERROR_INODE(dir, "bad inode number: %u", ino);
1425 return ERR_PTR(-EIO);
1426 }
1427 if (unlikely(ino == dir->i_ino)) {
1428 EXT4_ERROR_INODE(dir, "'%pd' linked to parent dir",
1429 dentry);
1430 return ERR_PTR(-EIO);
1431 }
1432 inode = ext4_iget(dir->i_sb, ino);
1433 if (inode == ERR_PTR(-ESTALE)) {
1434 EXT4_ERROR_INODE(dir,
1435 "deleted inode referenced: %u",
1436 ino);
1437 return ERR_PTR(-EIO);
1438 }
1439 }
1440 return d_splice_alias(inode, dentry);
1441}
1442
1443
1444struct dentry *ext4_get_parent(struct dentry *child)
1445{
1446 __u32 ino;
1447 static const struct qstr dotdot = QSTR_INIT("..", 2);
1448 struct ext4_dir_entry_2 * de;
1449 struct buffer_head *bh;
1450
1451 bh = ext4_find_entry(child->d_inode, &dotdot, &de, NULL);
1452 if (!bh)
1453 return ERR_PTR(-ENOENT);
1454 ino = le32_to_cpu(de->inode);
1455 brelse(bh);
1456
1457 if (!ext4_valid_inum(child->d_inode->i_sb, ino)) {
1458 EXT4_ERROR_INODE(child->d_inode,
1459 "bad parent inode number: %u", ino);
1460 return ERR_PTR(-EIO);
1461 }
1462
1463 return d_obtain_alias(ext4_iget(child->d_inode->i_sb, ino));
1464}
1465
1466/*
1467 * Move count entries from end of map between two memory locations.
1468 * Returns pointer to last entry moved.
1469 */
1470static struct ext4_dir_entry_2 *
1471dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count,
1472 unsigned blocksize)
1473{
1474 unsigned rec_len = 0;
1475
1476 while (count--) {
1477 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
1478 (from + (map->offs<<2));
1479 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1480 memcpy (to, de, rec_len);
1481 ((struct ext4_dir_entry_2 *) to)->rec_len =
1482 ext4_rec_len_to_disk(rec_len, blocksize);
1483 de->inode = 0;
1484 map++;
1485 to += rec_len;
1486 }
1487 return (struct ext4_dir_entry_2 *) (to - rec_len);
1488}
1489
1490/*
1491 * Compact each dir entry in the range to the minimal rec_len.
1492 * Returns pointer to last entry in range.
1493 */
1494static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize)
1495{
1496 struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
1497 unsigned rec_len = 0;
1498
1499 prev = to = de;
1500 while ((char*)de < base + blocksize) {
1501 next = ext4_next_entry(de, blocksize);
1502 if (de->inode && de->name_len) {
1503 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1504 if (de > to)
1505 memmove(to, de, rec_len);
1506 to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
1507 prev = to;
1508 to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
1509 }
1510 de = next;
1511 }
1512 return prev;
1513}
1514
1515/*
1516 * Split a full leaf block to make room for a new dir entry.
1517 * Allocate a new block, and move entries so that they are approx. equally full.
1518 * Returns pointer to de in block into which the new entry will be inserted.
1519 */
1520static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
1521 struct buffer_head **bh,struct dx_frame *frame,
1522 struct dx_hash_info *hinfo, int *error)
1523{
1524 unsigned blocksize = dir->i_sb->s_blocksize;
1525 unsigned count, continued;
1526 struct buffer_head *bh2;
1527 ext4_lblk_t newblock;
1528 u32 hash2;
1529 struct dx_map_entry *map;
1530 char *data1 = (*bh)->b_data, *data2;
1531 unsigned split, move, size;
1532 struct ext4_dir_entry_2 *de = NULL, *de2;
1533 struct ext4_dir_entry_tail *t;
1534 int csum_size = 0;
1535 int err = 0, i;
1536
1537 if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
1538 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
1539 csum_size = sizeof(struct ext4_dir_entry_tail);
1540
1541 bh2 = ext4_append(handle, dir, &newblock);
1542 if (IS_ERR(bh2)) {
1543 brelse(*bh);
1544 *bh = NULL;
1545 *error = PTR_ERR(bh2);
1546 return NULL;
1547 }
1548
1549 BUFFER_TRACE(*bh, "get_write_access");
1550 err = ext4_journal_get_write_access(handle, *bh);
1551 if (err)
1552 goto journal_error;
1553
1554 BUFFER_TRACE(frame->bh, "get_write_access");
1555 err = ext4_journal_get_write_access(handle, frame->bh);
1556 if (err)
1557 goto journal_error;
1558
1559 data2 = bh2->b_data;
1560
1561 /* create map in the end of data2 block */
1562 map = (struct dx_map_entry *) (data2 + blocksize);
1563 count = dx_make_map((struct ext4_dir_entry_2 *) data1,
1564 blocksize, hinfo, map);
1565 map -= count;
1566 dx_sort_map(map, count);
1567 /* Split the existing block in the middle, size-wise */
1568 size = 0;
1569 move = 0;
1570 for (i = count-1; i >= 0; i--) {
1571 /* is more than half of this entry in 2nd half of the block? */
1572 if (size + map[i].size/2 > blocksize/2)
1573 break;
1574 size += map[i].size;
1575 move++;
1576 }
1577 /* map index at which we will split */
1578 split = count - move;
1579 hash2 = map[split].hash;
1580 continued = hash2 == map[split - 1].hash;
1581 dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
1582 (unsigned long)dx_get_block(frame->at),
1583 hash2, split, count-split));
1584
1585 /* Fancy dance to stay within two buffers */
1586 de2 = dx_move_dirents(data1, data2, map + split, count - split, blocksize);
1587 de = dx_pack_dirents(data1, blocksize);
1588 de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
1589 (char *) de,
1590 blocksize);
1591 de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
1592 (char *) de2,
1593 blocksize);
1594 if (csum_size) {
1595 t = EXT4_DIRENT_TAIL(data2, blocksize);
1596 initialize_dirent_tail(t, blocksize);
1597
1598 t = EXT4_DIRENT_TAIL(data1, blocksize);
1599 initialize_dirent_tail(t, blocksize);
1600 }
1601
1602 dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data1, blocksize, 1));
1603 dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data2, blocksize, 1));
1604
1605 /* Which block gets the new entry? */
1606 if (hinfo->hash >= hash2)
1607 {
1608 swap(*bh, bh2);
1609 de = de2;
1610 }
1611 dx_insert_block(frame, hash2 + continued, newblock);
1612 err = ext4_handle_dirty_dirent_node(handle, dir, bh2);
1613 if (err)
1614 goto journal_error;
1615 err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
1616 if (err)
1617 goto journal_error;
1618 brelse(bh2);
1619 dxtrace(dx_show_index("frame", frame->entries));
1620 return de;
1621
1622journal_error:
1623 brelse(*bh);
1624 brelse(bh2);
1625 *bh = NULL;
1626 ext4_std_error(dir->i_sb, err);
1627 *error = err;
1628 return NULL;
1629}
1630
1631int ext4_find_dest_de(struct inode *dir, struct inode *inode,
1632 struct buffer_head *bh,
1633 void *buf, int buf_size,
1634 const char *name, int namelen,
1635 struct ext4_dir_entry_2 **dest_de)
1636{
1637 struct ext4_dir_entry_2 *de;
1638 unsigned short reclen = EXT4_DIR_REC_LEN(namelen);
1639 int nlen, rlen;
1640 unsigned int offset = 0;
1641 char *top;
1642
1643 de = (struct ext4_dir_entry_2 *)buf;
1644 top = buf + buf_size - reclen;
1645 while ((char *) de <= top) {
1646 if (ext4_check_dir_entry(dir, NULL, de, bh,
1647 buf, buf_size, offset))
1648 return -EIO;
1649 if (ext4_match(namelen, name, de))
1650 return -EEXIST;
1651 nlen = EXT4_DIR_REC_LEN(de->name_len);
1652 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
1653 if ((de->inode ? rlen - nlen : rlen) >= reclen)
1654 break;
1655 de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
1656 offset += rlen;
1657 }
1658 if ((char *) de > top)
1659 return -ENOSPC;
1660
1661 *dest_de = de;
1662 return 0;
1663}
1664
1665void ext4_insert_dentry(struct inode *inode,
1666 struct ext4_dir_entry_2 *de,
1667 int buf_size,
1668 const char *name, int namelen)
1669{
1670
1671 int nlen, rlen;
1672
1673 nlen = EXT4_DIR_REC_LEN(de->name_len);
1674 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
1675 if (de->inode) {
1676 struct ext4_dir_entry_2 *de1 =
1677 (struct ext4_dir_entry_2 *)((char *)de + nlen);
1678 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, buf_size);
1679 de->rec_len = ext4_rec_len_to_disk(nlen, buf_size);
1680 de = de1;
1681 }
1682 de->file_type = EXT4_FT_UNKNOWN;
1683 de->inode = cpu_to_le32(inode->i_ino);
1684 ext4_set_de_type(inode->i_sb, de, inode->i_mode);
1685 de->name_len = namelen;
1686 memcpy(de->name, name, namelen);
1687}
1688/*
1689 * Add a new entry into a directory (leaf) block. If de is non-NULL,
1690 * it points to a directory entry which is guaranteed to be large
1691 * enough for new directory entry. If de is NULL, then
1692 * add_dirent_to_buf will attempt search the directory block for
1693 * space. It will return -ENOSPC if no space is available, and -EIO
1694 * and -EEXIST if directory entry already exists.
1695 */
1696static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
1697 struct inode *inode, struct ext4_dir_entry_2 *de,
1698 struct buffer_head *bh)
1699{
1700 struct inode *dir = dentry->d_parent->d_inode;
1701 const char *name = dentry->d_name.name;
1702 int namelen = dentry->d_name.len;
1703 unsigned int blocksize = dir->i_sb->s_blocksize;
1704 int csum_size = 0;
1705 int err;
1706
1707 if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
1708 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
1709 csum_size = sizeof(struct ext4_dir_entry_tail);
1710
1711 if (!de) {
1712 err = ext4_find_dest_de(dir, inode,
1713 bh, bh->b_data, blocksize - csum_size,
1714 name, namelen, &de);
1715 if (err)
1716 return err;
1717 }
1718 BUFFER_TRACE(bh, "get_write_access");
1719 err = ext4_journal_get_write_access(handle, bh);
1720 if (err) {
1721 ext4_std_error(dir->i_sb, err);
1722 return err;
1723 }
1724
1725 /* By now the buffer is marked for journaling */
1726 ext4_insert_dentry(inode, de, blocksize, name, namelen);
1727
1728 /*
1729 * XXX shouldn't update any times until successful
1730 * completion of syscall, but too many callers depend
1731 * on this.
1732 *
1733 * XXX similarly, too many callers depend on
1734 * ext4_new_inode() setting the times, but error
1735 * recovery deletes the inode, so the worst that can
1736 * happen is that the times are slightly out of date
1737 * and/or different from the directory change time.
1738 */
1739 dir->i_mtime = dir->i_ctime = ext4_current_time(dir);
1740 ext4_update_dx_flag(dir);
1741 dir->i_version++;
1742 ext4_mark_inode_dirty(handle, dir);
1743 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1744 err = ext4_handle_dirty_dirent_node(handle, dir, bh);
1745 if (err)
1746 ext4_std_error(dir->i_sb, err);
1747 return 0;
1748}
1749
1750/*
1751 * This converts a one block unindexed directory to a 3 block indexed
1752 * directory, and adds the dentry to the indexed directory.
1753 */
1754static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
1755 struct inode *inode, struct buffer_head *bh)
1756{
1757 struct inode *dir = dentry->d_parent->d_inode;
1758 const char *name = dentry->d_name.name;
1759 int namelen = dentry->d_name.len;
1760 struct buffer_head *bh2;
1761 struct dx_root *root;
1762 struct dx_frame frames[2], *frame;
1763 struct dx_entry *entries;
1764 struct ext4_dir_entry_2 *de, *de2;
1765 struct ext4_dir_entry_tail *t;
1766 char *data1, *top;
1767 unsigned len;
1768 int retval;
1769 unsigned blocksize;
1770 struct dx_hash_info hinfo;
1771 ext4_lblk_t block;
1772 struct fake_dirent *fde;
1773 int csum_size = 0;
1774
1775 if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
1776 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
1777 csum_size = sizeof(struct ext4_dir_entry_tail);
1778
1779 blocksize = dir->i_sb->s_blocksize;
1780 dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
1781 retval = ext4_journal_get_write_access(handle, bh);
1782 if (retval) {
1783 ext4_std_error(dir->i_sb, retval);
1784 brelse(bh);
1785 return retval;
1786 }
1787 root = (struct dx_root *) bh->b_data;
1788
1789 /* The 0th block becomes the root, move the dirents out */
1790 fde = &root->dotdot;
1791 de = (struct ext4_dir_entry_2 *)((char *)fde +
1792 ext4_rec_len_from_disk(fde->rec_len, blocksize));
1793 if ((char *) de >= (((char *) root) + blocksize)) {
1794 EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
1795 brelse(bh);
1796 return -EIO;
1797 }
1798 len = ((char *) root) + (blocksize - csum_size) - (char *) de;
1799
1800 /* Allocate new block for the 0th block's dirents */
1801 bh2 = ext4_append(handle, dir, &block);
1802 if (IS_ERR(bh2)) {
1803 brelse(bh);
1804 return PTR_ERR(bh2);
1805 }
1806 ext4_set_inode_flag(dir, EXT4_INODE_INDEX);
1807 data1 = bh2->b_data;
1808
1809 memcpy (data1, de, len);
1810 de = (struct ext4_dir_entry_2 *) data1;
1811 top = data1 + len;
1812 while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
1813 de = de2;
1814 de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
1815 (char *) de,
1816 blocksize);
1817
1818 if (csum_size) {
1819 t = EXT4_DIRENT_TAIL(data1, blocksize);
1820 initialize_dirent_tail(t, blocksize);
1821 }
1822
1823 /* Initialize the root; the dot dirents already exist */
1824 de = (struct ext4_dir_entry_2 *) (&root->dotdot);
1825 de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
1826 blocksize);
1827 memset (&root->info, 0, sizeof(root->info));
1828 root->info.info_length = sizeof(root->info);
1829 root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
1830 entries = root->entries;
1831 dx_set_block(entries, 1);
1832 dx_set_count(entries, 1);
1833 dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
1834
1835 /* Initialize as for dx_probe */
1836 hinfo.hash_version = root->info.hash_version;
1837 if (hinfo.hash_version <= DX_HASH_TEA)
1838 hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
1839 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
1840 ext4fs_dirhash(name, namelen, &hinfo);
1841 frame = frames;
1842 frame->entries = entries;
1843 frame->at = entries;
1844 frame->bh = bh;
1845 bh = bh2;
1846
1847 ext4_handle_dirty_dx_node(handle, dir, frame->bh);
1848 ext4_handle_dirty_dirent_node(handle, dir, bh);
1849
1850 de = do_split(handle,dir, &bh, frame, &hinfo, &retval);
1851 if (!de) {
1852 /*
1853 * Even if the block split failed, we have to properly write
1854 * out all the changes we did so far. Otherwise we can end up
1855 * with corrupted filesystem.
1856 */
1857 ext4_mark_inode_dirty(handle, dir);
1858 dx_release(frames);
1859 return retval;
1860 }
1861 dx_release(frames);
1862
1863 retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
1864 brelse(bh);
1865 return retval;
1866}
1867
1868/*
1869 * ext4_add_entry()
1870 *
1871 * adds a file entry to the specified directory, using the same
1872 * semantics as ext4_find_entry(). It returns NULL if it failed.
1873 *
1874 * NOTE!! The inode part of 'de' is left at 0 - which means you
1875 * may not sleep between calling this and putting something into
1876 * the entry, as someone else might have used it while you slept.
1877 */
1878static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
1879 struct inode *inode)
1880{
1881 struct inode *dir = dentry->d_parent->d_inode;
1882 struct buffer_head *bh;
1883 struct ext4_dir_entry_2 *de;
1884 struct ext4_dir_entry_tail *t;
1885 struct super_block *sb;
1886 int retval;
1887 int dx_fallback=0;
1888 unsigned blocksize;
1889 ext4_lblk_t block, blocks;
1890 int csum_size = 0;
1891
1892 if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
1893 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
1894 csum_size = sizeof(struct ext4_dir_entry_tail);
1895
1896 sb = dir->i_sb;
1897 blocksize = sb->s_blocksize;
1898 if (!dentry->d_name.len)
1899 return -EINVAL;
1900
1901 if (ext4_has_inline_data(dir)) {
1902 retval = ext4_try_add_inline_entry(handle, dentry, inode);
1903 if (retval < 0)
1904 return retval;
1905 if (retval == 1) {
1906 retval = 0;
1907 return retval;
1908 }
1909 }
1910
1911 if (is_dx(dir)) {
1912 retval = ext4_dx_add_entry(handle, dentry, inode);
1913 if (!retval || (retval != ERR_BAD_DX_DIR))
1914 return retval;
1915 ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
1916 dx_fallback++;
1917 ext4_mark_inode_dirty(handle, dir);
1918 }
1919 blocks = dir->i_size >> sb->s_blocksize_bits;
1920 for (block = 0; block < blocks; block++) {
1921 bh = ext4_read_dirblock(dir, block, DIRENT);
1922 if (IS_ERR(bh))
1923 return PTR_ERR(bh);
1924
1925 retval = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
1926 if (retval != -ENOSPC) {
1927 brelse(bh);
1928 return retval;
1929 }
1930
1931 if (blocks == 1 && !dx_fallback &&
1932 EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX))
1933 return make_indexed_dir(handle, dentry, inode, bh);
1934 brelse(bh);
1935 }
1936 bh = ext4_append(handle, dir, &block);
1937 if (IS_ERR(bh))
1938 return PTR_ERR(bh);
1939 de = (struct ext4_dir_entry_2 *) bh->b_data;
1940 de->inode = 0;
1941 de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize);
1942
1943 if (csum_size) {
1944 t = EXT4_DIRENT_TAIL(bh->b_data, blocksize);
1945 initialize_dirent_tail(t, blocksize);
1946 }
1947
1948 retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
1949 brelse(bh);
1950 if (retval == 0)
1951 ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY);
1952 return retval;
1953}
1954
1955/*
1956 * Returns 0 for success, or a negative error value
1957 */
1958static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
1959 struct inode *inode)
1960{
1961 struct dx_frame frames[2], *frame;
1962 struct dx_entry *entries, *at;
1963 struct dx_hash_info hinfo;
1964 struct buffer_head *bh;
1965 struct inode *dir = dentry->d_parent->d_inode;
1966 struct super_block *sb = dir->i_sb;
1967 struct ext4_dir_entry_2 *de;
1968 int err;
1969
1970 frame = dx_probe(&dentry->d_name, dir, &hinfo, frames, &err);
1971 if (!frame)
1972 return err;
1973 entries = frame->entries;
1974 at = frame->at;
1975 bh = ext4_read_dirblock(dir, dx_get_block(frame->at), DIRENT);
1976 if (IS_ERR(bh)) {
1977 err = PTR_ERR(bh);
1978 bh = NULL;
1979 goto cleanup;
1980 }
1981
1982 BUFFER_TRACE(bh, "get_write_access");
1983 err = ext4_journal_get_write_access(handle, bh);
1984 if (err)
1985 goto journal_error;
1986
1987 err = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
1988 if (err != -ENOSPC)
1989 goto cleanup;
1990
1991 /* Block full, should compress but for now just split */
1992 dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
1993 dx_get_count(entries), dx_get_limit(entries)));
1994 /* Need to split index? */
1995 if (dx_get_count(entries) == dx_get_limit(entries)) {
1996 ext4_lblk_t newblock;
1997 unsigned icount = dx_get_count(entries);
1998 int levels = frame - frames;
1999 struct dx_entry *entries2;
2000 struct dx_node *node2;
2001 struct buffer_head *bh2;
2002
2003 if (levels && (dx_get_count(frames->entries) ==
2004 dx_get_limit(frames->entries))) {
2005 ext4_warning(sb, "Directory index full!");
2006 err = -ENOSPC;
2007 goto cleanup;
2008 }
2009 bh2 = ext4_append(handle, dir, &newblock);
2010 if (IS_ERR(bh2)) {
2011 err = PTR_ERR(bh2);
2012 goto cleanup;
2013 }
2014 node2 = (struct dx_node *)(bh2->b_data);
2015 entries2 = node2->entries;
2016 memset(&node2->fake, 0, sizeof(struct fake_dirent));
2017 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
2018 sb->s_blocksize);
2019 BUFFER_TRACE(frame->bh, "get_write_access");
2020 err = ext4_journal_get_write_access(handle, frame->bh);
2021 if (err)
2022 goto journal_error;
2023 if (levels) {
2024 unsigned icount1 = icount/2, icount2 = icount - icount1;
2025 unsigned hash2 = dx_get_hash(entries + icount1);
2026 dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
2027 icount1, icount2));
2028
2029 BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
2030 err = ext4_journal_get_write_access(handle,
2031 frames[0].bh);
2032 if (err)
2033 goto journal_error;
2034
2035 memcpy((char *) entries2, (char *) (entries + icount1),
2036 icount2 * sizeof(struct dx_entry));
2037 dx_set_count(entries, icount1);
2038 dx_set_count(entries2, icount2);
2039 dx_set_limit(entries2, dx_node_limit(dir));
2040
2041 /* Which index block gets the new entry? */
2042 if (at - entries >= icount1) {
2043 frame->at = at = at - entries - icount1 + entries2;
2044 frame->entries = entries = entries2;
2045 swap(frame->bh, bh2);
2046 }
2047 dx_insert_block(frames + 0, hash2, newblock);
2048 dxtrace(dx_show_index("node", frames[1].entries));
2049 dxtrace(dx_show_index("node",
2050 ((struct dx_node *) bh2->b_data)->entries));
2051 err = ext4_handle_dirty_dx_node(handle, dir, bh2);
2052 if (err)
2053 goto journal_error;
2054 brelse (bh2);
2055 } else {
2056 dxtrace(printk(KERN_DEBUG
2057 "Creating second level index...\n"));
2058 memcpy((char *) entries2, (char *) entries,
2059 icount * sizeof(struct dx_entry));
2060 dx_set_limit(entries2, dx_node_limit(dir));
2061
2062 /* Set up root */
2063 dx_set_count(entries, 1);
2064 dx_set_block(entries + 0, newblock);
2065 ((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels = 1;
2066
2067 /* Add new access path frame */
2068 frame = frames + 1;
2069 frame->at = at = at - entries + entries2;
2070 frame->entries = entries = entries2;
2071 frame->bh = bh2;
2072 err = ext4_journal_get_write_access(handle,
2073 frame->bh);
2074 if (err)
2075 goto journal_error;
2076 }
2077 err = ext4_handle_dirty_dx_node(handle, dir, frames[0].bh);
2078 if (err) {
2079 ext4_std_error(inode->i_sb, err);
2080 goto cleanup;
2081 }
2082 }
2083 de = do_split(handle, dir, &bh, frame, &hinfo, &err);
2084 if (!de)
2085 goto cleanup;
2086 err = add_dirent_to_buf(handle, dentry, inode, de, bh);
2087 goto cleanup;
2088
2089journal_error:
2090 ext4_std_error(dir->i_sb, err);
2091cleanup:
2092 brelse(bh);
2093 dx_release(frames);
2094 return err;
2095}
2096
2097/*
2098 * ext4_generic_delete_entry deletes a directory entry by merging it
2099 * with the previous entry
2100 */
2101int ext4_generic_delete_entry(handle_t *handle,
2102 struct inode *dir,
2103 struct ext4_dir_entry_2 *de_del,
2104 struct buffer_head *bh,
2105 void *entry_buf,
2106 int buf_size,
2107 int csum_size)
2108{
2109 struct ext4_dir_entry_2 *de, *pde;
2110 unsigned int blocksize = dir->i_sb->s_blocksize;
2111 int i;
2112
2113 i = 0;
2114 pde = NULL;
2115 de = (struct ext4_dir_entry_2 *)entry_buf;
2116 while (i < buf_size - csum_size) {
2117 if (ext4_check_dir_entry(dir, NULL, de, bh,
2118 bh->b_data, bh->b_size, i))
2119 return -EIO;
2120 if (de == de_del) {
2121 if (pde)
2122 pde->rec_len = ext4_rec_len_to_disk(
2123 ext4_rec_len_from_disk(pde->rec_len,
2124 blocksize) +
2125 ext4_rec_len_from_disk(de->rec_len,
2126 blocksize),
2127 blocksize);
2128 else
2129 de->inode = 0;
2130 dir->i_version++;
2131 return 0;
2132 }
2133 i += ext4_rec_len_from_disk(de->rec_len, blocksize);
2134 pde = de;
2135 de = ext4_next_entry(de, blocksize);
2136 }
2137 return -ENOENT;
2138}
2139
2140static int ext4_delete_entry(handle_t *handle,
2141 struct inode *dir,
2142 struct ext4_dir_entry_2 *de_del,
2143 struct buffer_head *bh)
2144{
2145 int err, csum_size = 0;
2146
2147 if (ext4_has_inline_data(dir)) {
2148 int has_inline_data = 1;
2149 err = ext4_delete_inline_entry(handle, dir, de_del, bh,
2150 &has_inline_data);
2151 if (has_inline_data)
2152 return err;
2153 }
2154
2155 if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
2156 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
2157 csum_size = sizeof(struct ext4_dir_entry_tail);
2158
2159 BUFFER_TRACE(bh, "get_write_access");
2160 err = ext4_journal_get_write_access(handle, bh);
2161 if (unlikely(err))
2162 goto out;
2163
2164 err = ext4_generic_delete_entry(handle, dir, de_del,
2165 bh, bh->b_data,
2166 dir->i_sb->s_blocksize, csum_size);
2167 if (err)
2168 goto out;
2169
2170 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
2171 err = ext4_handle_dirty_dirent_node(handle, dir, bh);
2172 if (unlikely(err))
2173 goto out;
2174
2175 return 0;
2176out:
2177 if (err != -ENOENT)
2178 ext4_std_error(dir->i_sb, err);
2179 return err;
2180}
2181
2182/*
2183 * DIR_NLINK feature is set if 1) nlinks > EXT4_LINK_MAX or 2) nlinks == 2,
2184 * since this indicates that nlinks count was previously 1.
2185 */
2186static void ext4_inc_count(handle_t *handle, struct inode *inode)
2187{
2188 inc_nlink(inode);
2189 if (is_dx(inode) && inode->i_nlink > 1) {
2190 /* limit is 16-bit i_links_count */
2191 if (inode->i_nlink >= EXT4_LINK_MAX || inode->i_nlink == 2) {
2192 set_nlink(inode, 1);
2193 EXT4_SET_RO_COMPAT_FEATURE(inode->i_sb,
2194 EXT4_FEATURE_RO_COMPAT_DIR_NLINK);
2195 }
2196 }
2197}
2198
2199/*
2200 * If a directory had nlink == 1, then we should let it be 1. This indicates
2201 * directory has >EXT4_LINK_MAX subdirs.
2202 */
2203static void ext4_dec_count(handle_t *handle, struct inode *inode)
2204{
2205 if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
2206 drop_nlink(inode);
2207}
2208
2209
2210static int ext4_add_nondir(handle_t *handle,
2211 struct dentry *dentry, struct inode *inode)
2212{
2213 int err = ext4_add_entry(handle, dentry, inode);
2214 if (!err) {
2215 ext4_mark_inode_dirty(handle, inode);
2216 unlock_new_inode(inode);
2217 d_instantiate(dentry, inode);
2218 return 0;
2219 }
2220 drop_nlink(inode);
2221 unlock_new_inode(inode);
2222 iput(inode);
2223 return err;
2224}
2225
2226/*
2227 * By the time this is called, we already have created
2228 * the directory cache entry for the new file, but it
2229 * is so far negative - it has no inode.
2230 *
2231 * If the create succeeds, we fill in the inode information
2232 * with d_instantiate().
2233 */
2234static int ext4_create(struct inode *dir, struct dentry *dentry, umode_t mode,
2235 bool excl)
2236{
2237 handle_t *handle;
2238 struct inode *inode;
2239 int err, credits, retries = 0;
2240
2241 dquot_initialize(dir);
2242
2243 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2244 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2245retry:
2246 inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
2247 NULL, EXT4_HT_DIR, credits);
2248 handle = ext4_journal_current_handle();
2249 err = PTR_ERR(inode);
2250 if (!IS_ERR(inode)) {
2251 inode->i_op = &ext4_file_inode_operations;
2252 inode->i_fop = &ext4_file_operations;
2253 ext4_set_aops(inode);
2254 err = ext4_add_nondir(handle, dentry, inode);
2255 if (!err && IS_DIRSYNC(dir))
2256 ext4_handle_sync(handle);
2257 }
2258 if (handle)
2259 ext4_journal_stop(handle);
2260 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2261 goto retry;
2262 return err;
2263}
2264
2265static int ext4_mknod(struct inode *dir, struct dentry *dentry,
2266 umode_t mode, dev_t rdev)
2267{
2268 handle_t *handle;
2269 struct inode *inode;
2270 int err, credits, retries = 0;
2271
2272 if (!new_valid_dev(rdev))
2273 return -EINVAL;
2274
2275 dquot_initialize(dir);
2276
2277 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2278 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2279retry:
2280 inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
2281 NULL, EXT4_HT_DIR, credits);
2282 handle = ext4_journal_current_handle();
2283 err = PTR_ERR(inode);
2284 if (!IS_ERR(inode)) {
2285 init_special_inode(inode, inode->i_mode, rdev);
2286 inode->i_op = &ext4_special_inode_operations;
2287 err = ext4_add_nondir(handle, dentry, inode);
2288 if (!err && IS_DIRSYNC(dir))
2289 ext4_handle_sync(handle);
2290 }
2291 if (handle)
2292 ext4_journal_stop(handle);
2293 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2294 goto retry;
2295 return err;
2296}
2297
2298static int ext4_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
2299{
2300 handle_t *handle;
2301 struct inode *inode;
2302 int err, retries = 0;
2303
2304 dquot_initialize(dir);
2305
2306retry:
2307 inode = ext4_new_inode_start_handle(dir, mode,
2308 NULL, 0, NULL,
2309 EXT4_HT_DIR,
2310 EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
2311 4 + EXT4_XATTR_TRANS_BLOCKS);
2312 handle = ext4_journal_current_handle();
2313 err = PTR_ERR(inode);
2314 if (!IS_ERR(inode)) {
2315 inode->i_op = &ext4_file_inode_operations;
2316 inode->i_fop = &ext4_file_operations;
2317 ext4_set_aops(inode);
2318 d_tmpfile(dentry, inode);
2319 err = ext4_orphan_add(handle, inode);
2320 if (err)
2321 goto err_unlock_inode;
2322 mark_inode_dirty(inode);
2323 unlock_new_inode(inode);
2324 }
2325 if (handle)
2326 ext4_journal_stop(handle);
2327 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2328 goto retry;
2329 return err;
2330err_unlock_inode:
2331 ext4_journal_stop(handle);
2332 unlock_new_inode(inode);
2333 return err;
2334}
2335
2336struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
2337 struct ext4_dir_entry_2 *de,
2338 int blocksize, int csum_size,
2339 unsigned int parent_ino, int dotdot_real_len)
2340{
2341 de->inode = cpu_to_le32(inode->i_ino);
2342 de->name_len = 1;
2343 de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
2344 blocksize);
2345 strcpy(de->name, ".");
2346 ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2347
2348 de = ext4_next_entry(de, blocksize);
2349 de->inode = cpu_to_le32(parent_ino);
2350 de->name_len = 2;
2351 if (!dotdot_real_len)
2352 de->rec_len = ext4_rec_len_to_disk(blocksize -
2353 (csum_size + EXT4_DIR_REC_LEN(1)),
2354 blocksize);
2355 else
2356 de->rec_len = ext4_rec_len_to_disk(
2357 EXT4_DIR_REC_LEN(de->name_len), blocksize);
2358 strcpy(de->name, "..");
2359 ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2360
2361 return ext4_next_entry(de, blocksize);
2362}
2363
2364static int ext4_init_new_dir(handle_t *handle, struct inode *dir,
2365 struct inode *inode)
2366{
2367 struct buffer_head *dir_block = NULL;
2368 struct ext4_dir_entry_2 *de;
2369 struct ext4_dir_entry_tail *t;
2370 ext4_lblk_t block = 0;
2371 unsigned int blocksize = dir->i_sb->s_blocksize;
2372 int csum_size = 0;
2373 int err;
2374
2375 if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
2376 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
2377 csum_size = sizeof(struct ext4_dir_entry_tail);
2378
2379 if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
2380 err = ext4_try_create_inline_dir(handle, dir, inode);
2381 if (err < 0 && err != -ENOSPC)
2382 goto out;
2383 if (!err)
2384 goto out;
2385 }
2386
2387 inode->i_size = 0;
2388 dir_block = ext4_append(handle, inode, &block);
2389 if (IS_ERR(dir_block))
2390 return PTR_ERR(dir_block);
2391 BUFFER_TRACE(dir_block, "get_write_access");
2392 err = ext4_journal_get_write_access(handle, dir_block);
2393 if (err)
2394 goto out;
2395 de = (struct ext4_dir_entry_2 *)dir_block->b_data;
2396 ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0);
2397 set_nlink(inode, 2);
2398 if (csum_size) {
2399 t = EXT4_DIRENT_TAIL(dir_block->b_data, blocksize);
2400 initialize_dirent_tail(t, blocksize);
2401 }
2402
2403 BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
2404 err = ext4_handle_dirty_dirent_node(handle, inode, dir_block);
2405 if (err)
2406 goto out;
2407 set_buffer_verified(dir_block);
2408out:
2409 brelse(dir_block);
2410 return err;
2411}
2412
2413static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
2414{
2415 handle_t *handle;
2416 struct inode *inode;
2417 int err, credits, retries = 0;
2418
2419 if (EXT4_DIR_LINK_MAX(dir))
2420 return -EMLINK;
2421
2422 dquot_initialize(dir);
2423
2424 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2425 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2426retry:
2427 inode = ext4_new_inode_start_handle(dir, S_IFDIR | mode,
2428 &dentry->d_name,
2429 0, NULL, EXT4_HT_DIR, credits);
2430 handle = ext4_journal_current_handle();
2431 err = PTR_ERR(inode);
2432 if (IS_ERR(inode))
2433 goto out_stop;
2434
2435 inode->i_op = &ext4_dir_inode_operations;
2436 inode->i_fop = &ext4_dir_operations;
2437 err = ext4_init_new_dir(handle, dir, inode);
2438 if (err)
2439 goto out_clear_inode;
2440 err = ext4_mark_inode_dirty(handle, inode);
2441 if (!err)
2442 err = ext4_add_entry(handle, dentry, inode);
2443 if (err) {
2444out_clear_inode:
2445 clear_nlink(inode);
2446 unlock_new_inode(inode);
2447 ext4_mark_inode_dirty(handle, inode);
2448 iput(inode);
2449 goto out_stop;
2450 }
2451 ext4_inc_count(handle, dir);
2452 ext4_update_dx_flag(dir);
2453 err = ext4_mark_inode_dirty(handle, dir);
2454 if (err)
2455 goto out_clear_inode;
2456 unlock_new_inode(inode);
2457 d_instantiate(dentry, inode);
2458 if (IS_DIRSYNC(dir))
2459 ext4_handle_sync(handle);
2460
2461out_stop:
2462 if (handle)
2463 ext4_journal_stop(handle);
2464 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2465 goto retry;
2466 return err;
2467}
2468
2469/*
2470 * routine to check that the specified directory is empty (for rmdir)
2471 */
2472static int empty_dir(struct inode *inode)
2473{
2474 unsigned int offset;
2475 struct buffer_head *bh;
2476 struct ext4_dir_entry_2 *de, *de1;
2477 struct super_block *sb;
2478 int err = 0;
2479
2480 if (ext4_has_inline_data(inode)) {
2481 int has_inline_data = 1;
2482
2483 err = empty_inline_dir(inode, &has_inline_data);
2484 if (has_inline_data)
2485 return err;
2486 }
2487
2488 sb = inode->i_sb;
2489 if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2)) {
2490 EXT4_ERROR_INODE(inode, "invalid size");
2491 return 1;
2492 }
2493 bh = ext4_read_dirblock(inode, 0, EITHER);
2494 if (IS_ERR(bh))
2495 return 1;
2496
2497 de = (struct ext4_dir_entry_2 *) bh->b_data;
2498 de1 = ext4_next_entry(de, sb->s_blocksize);
2499 if (le32_to_cpu(de->inode) != inode->i_ino ||
2500 !le32_to_cpu(de1->inode) ||
2501 strcmp(".", de->name) ||
2502 strcmp("..", de1->name)) {
2503 ext4_warning(inode->i_sb,
2504 "bad directory (dir #%lu) - no `.' or `..'",
2505 inode->i_ino);
2506 brelse(bh);
2507 return 1;
2508 }
2509 offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) +
2510 ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize);
2511 de = ext4_next_entry(de1, sb->s_blocksize);
2512 while (offset < inode->i_size) {
2513 if (!bh ||
2514 (void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
2515 unsigned int lblock;
2516 err = 0;
2517 brelse(bh);
2518 lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb);
2519 bh = ext4_read_dirblock(inode, lblock, EITHER);
2520 if (IS_ERR(bh))
2521 return 1;
2522 de = (struct ext4_dir_entry_2 *) bh->b_data;
2523 }
2524 if (ext4_check_dir_entry(inode, NULL, de, bh,
2525 bh->b_data, bh->b_size, offset)) {
2526 de = (struct ext4_dir_entry_2 *)(bh->b_data +
2527 sb->s_blocksize);
2528 offset = (offset | (sb->s_blocksize - 1)) + 1;
2529 continue;
2530 }
2531 if (le32_to_cpu(de->inode)) {
2532 brelse(bh);
2533 return 0;
2534 }
2535 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
2536 de = ext4_next_entry(de, sb->s_blocksize);
2537 }
2538 brelse(bh);
2539 return 1;
2540}
2541
2542/* ext4_orphan_add() links an unlinked or truncated inode into a list of
2543 * such inodes, starting at the superblock, in case we crash before the
2544 * file is closed/deleted, or in case the inode truncate spans multiple
2545 * transactions and the last transaction is not recovered after a crash.
2546 *
2547 * At filesystem recovery time, we walk this list deleting unlinked
2548 * inodes and truncating linked inodes in ext4_orphan_cleanup().
2549 */
2550int ext4_orphan_add(handle_t *handle, struct inode *inode)
2551{
2552 struct super_block *sb = inode->i_sb;
2553 struct ext4_iloc iloc;
2554 int err = 0, rc;
2555
2556 if (!EXT4_SB(sb)->s_journal)
2557 return 0;
2558
2559 mutex_lock(&EXT4_SB(sb)->s_orphan_lock);
2560 if (!list_empty(&EXT4_I(inode)->i_orphan))
2561 goto out_unlock;
2562
2563 /*
2564 * Orphan handling is only valid for files with data blocks
2565 * being truncated, or files being unlinked. Note that we either
2566 * hold i_mutex, or the inode can not be referenced from outside,
2567 * so i_nlink should not be bumped due to race
2568 */
2569 J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2570 S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
2571
2572 BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access");
2573 err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
2574 if (err)
2575 goto out_unlock;
2576
2577 err = ext4_reserve_inode_write(handle, inode, &iloc);
2578 if (err)
2579 goto out_unlock;
2580 /*
2581 * Due to previous errors inode may be already a part of on-disk
2582 * orphan list. If so skip on-disk list modification.
2583 */
2584 if (NEXT_ORPHAN(inode) && NEXT_ORPHAN(inode) <=
2585 (le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count)))
2586 goto mem_insert;
2587
2588 /* Insert this inode at the head of the on-disk orphan list... */
2589 NEXT_ORPHAN(inode) = le32_to_cpu(EXT4_SB(sb)->s_es->s_last_orphan);
2590 EXT4_SB(sb)->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
2591 err = ext4_handle_dirty_super(handle, sb);
2592 rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
2593 if (!err)
2594 err = rc;
2595
2596 /* Only add to the head of the in-memory list if all the
2597 * previous operations succeeded. If the orphan_add is going to
2598 * fail (possibly taking the journal offline), we can't risk
2599 * leaving the inode on the orphan list: stray orphan-list
2600 * entries can cause panics at unmount time.
2601 *
2602 * This is safe: on error we're going to ignore the orphan list
2603 * anyway on the next recovery. */
2604mem_insert:
2605 if (!err)
2606 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
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));
2611out_unlock:
2612 mutex_unlock(&EXT4_SB(sb)->s_orphan_lock);
2613 ext4_std_error(inode->i_sb, err);
2614 return err;
2615}
2616
2617/*
2618 * ext4_orphan_del() removes an unlinked or truncated inode from the list
2619 * of such inodes stored on disk, because it is finally being cleaned up.
2620 */
2621int ext4_orphan_del(handle_t *handle, struct inode *inode)
2622{
2623 struct list_head *prev;
2624 struct ext4_inode_info *ei = EXT4_I(inode);
2625 struct ext4_sb_info *sbi;
2626 __u32 ino_next;
2627 struct ext4_iloc iloc;
2628 int err = 0;
2629
2630 if ((!EXT4_SB(inode->i_sb)->s_journal) &&
2631 !(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_ORPHAN_FS))
2632 return 0;
2633
2634 mutex_lock(&EXT4_SB(inode->i_sb)->s_orphan_lock);
2635 if (list_empty(&ei->i_orphan))
2636 goto out;
2637
2638 ino_next = NEXT_ORPHAN(inode);
2639 prev = ei->i_orphan.prev;
2640 sbi = EXT4_SB(inode->i_sb);
2641
2642 jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
2643
2644 list_del_init(&ei->i_orphan);
2645
2646 /* If we're on an error path, we may not have a valid
2647 * transaction handle with which to update the orphan list on
2648 * disk, but we still need to remove the inode from the linked
2649 * list in memory. */
2650 if (!handle)
2651 goto out;
2652
2653 err = ext4_reserve_inode_write(handle, inode, &iloc);
2654 if (err)
2655 goto out_err;
2656
2657 if (prev == &sbi->s_orphan) {
2658 jbd_debug(4, "superblock will point to %u\n", ino_next);
2659 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2660 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2661 if (err)
2662 goto out_brelse;
2663 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
2664 err = ext4_handle_dirty_super(handle, inode->i_sb);
2665 } else {
2666 struct ext4_iloc iloc2;
2667 struct inode *i_prev =
2668 &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
2669
2670 jbd_debug(4, "orphan inode %lu will point to %u\n",
2671 i_prev->i_ino, ino_next);
2672 err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
2673 if (err)
2674 goto out_brelse;
2675 NEXT_ORPHAN(i_prev) = ino_next;
2676 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
2677 }
2678 if (err)
2679 goto out_brelse;
2680 NEXT_ORPHAN(inode) = 0;
2681 err = ext4_mark_iloc_dirty(handle, inode, &iloc);
2682
2683out_err:
2684 ext4_std_error(inode->i_sb, err);
2685out:
2686 mutex_unlock(&EXT4_SB(inode->i_sb)->s_orphan_lock);
2687 return err;
2688
2689out_brelse:
2690 brelse(iloc.bh);
2691 goto out_err;
2692}
2693
2694static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
2695{
2696 int retval;
2697 struct inode *inode;
2698 struct buffer_head *bh;
2699 struct ext4_dir_entry_2 *de;
2700 handle_t *handle = NULL;
2701
2702 /* Initialize quotas before so that eventual writes go in
2703 * separate transaction */
2704 dquot_initialize(dir);
2705 dquot_initialize(dentry->d_inode);
2706
2707 retval = -ENOENT;
2708 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
2709 if (!bh)
2710 goto end_rmdir;
2711
2712 inode = dentry->d_inode;
2713
2714 retval = -EIO;
2715 if (le32_to_cpu(de->inode) != inode->i_ino)
2716 goto end_rmdir;
2717
2718 retval = -ENOTEMPTY;
2719 if (!empty_dir(inode))
2720 goto end_rmdir;
2721
2722 handle = ext4_journal_start(dir, EXT4_HT_DIR,
2723 EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
2724 if (IS_ERR(handle)) {
2725 retval = PTR_ERR(handle);
2726 handle = NULL;
2727 goto end_rmdir;
2728 }
2729
2730 if (IS_DIRSYNC(dir))
2731 ext4_handle_sync(handle);
2732
2733 retval = ext4_delete_entry(handle, dir, de, bh);
2734 if (retval)
2735 goto end_rmdir;
2736 if (!EXT4_DIR_LINK_EMPTY(inode))
2737 ext4_warning(inode->i_sb,
2738 "empty directory has too many links (%d)",
2739 inode->i_nlink);
2740 inode->i_version++;
2741 clear_nlink(inode);
2742 /* There's no need to set i_disksize: the fact that i_nlink is
2743 * zero will ensure that the right thing happens during any
2744 * recovery. */
2745 inode->i_size = 0;
2746 ext4_orphan_add(handle, inode);
2747 inode->i_ctime = dir->i_ctime = dir->i_mtime = ext4_current_time(inode);
2748 ext4_mark_inode_dirty(handle, inode);
2749 ext4_dec_count(handle, dir);
2750 ext4_update_dx_flag(dir);
2751 ext4_mark_inode_dirty(handle, dir);
2752
2753end_rmdir:
2754 brelse(bh);
2755 if (handle)
2756 ext4_journal_stop(handle);
2757 return retval;
2758}
2759
2760static int ext4_unlink(struct inode *dir, struct dentry *dentry)
2761{
2762 int retval;
2763 struct inode *inode;
2764 struct buffer_head *bh;
2765 struct ext4_dir_entry_2 *de;
2766 handle_t *handle = NULL;
2767
2768 trace_ext4_unlink_enter(dir, dentry);
2769 /* Initialize quotas before so that eventual writes go
2770 * in separate transaction */
2771 dquot_initialize(dir);
2772 dquot_initialize(dentry->d_inode);
2773
2774 retval = -ENOENT;
2775 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
2776 if (!bh)
2777 goto end_unlink;
2778
2779 inode = dentry->d_inode;
2780
2781 retval = -EIO;
2782 if (le32_to_cpu(de->inode) != inode->i_ino)
2783 goto end_unlink;
2784
2785 handle = ext4_journal_start(dir, EXT4_HT_DIR,
2786 EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
2787 if (IS_ERR(handle)) {
2788 retval = PTR_ERR(handle);
2789 handle = NULL;
2790 goto end_unlink;
2791 }
2792
2793 if (IS_DIRSYNC(dir))
2794 ext4_handle_sync(handle);
2795
2796 if (!inode->i_nlink) {
2797 ext4_warning(inode->i_sb,
2798 "Deleting nonexistent file (%lu), %d",
2799 inode->i_ino, inode->i_nlink);
2800 set_nlink(inode, 1);
2801 }
2802 retval = ext4_delete_entry(handle, dir, de, bh);
2803 if (retval)
2804 goto end_unlink;
2805 dir->i_ctime = dir->i_mtime = ext4_current_time(dir);
2806 ext4_update_dx_flag(dir);
2807 ext4_mark_inode_dirty(handle, dir);
2808 drop_nlink(inode);
2809 if (!inode->i_nlink)
2810 ext4_orphan_add(handle, inode);
2811 inode->i_ctime = ext4_current_time(inode);
2812 ext4_mark_inode_dirty(handle, inode);
2813 retval = 0;
2814
2815end_unlink:
2816 brelse(bh);
2817 if (handle)
2818 ext4_journal_stop(handle);
2819 trace_ext4_unlink_exit(dentry, retval);
2820 return retval;
2821}
2822
2823static int ext4_symlink(struct inode *dir,
2824 struct dentry *dentry, const char *symname)
2825{
2826 handle_t *handle;
2827 struct inode *inode;
2828 int l, err, retries = 0;
2829 int credits;
2830
2831 l = strlen(symname)+1;
2832 if (l > dir->i_sb->s_blocksize)
2833 return -ENAMETOOLONG;
2834
2835 dquot_initialize(dir);
2836
2837 if (l > EXT4_N_BLOCKS * 4) {
2838 /*
2839 * For non-fast symlinks, we just allocate inode and put it on
2840 * orphan list in the first transaction => we need bitmap,
2841 * group descriptor, sb, inode block, quota blocks, and
2842 * possibly selinux xattr blocks.
2843 */
2844 credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
2845 EXT4_XATTR_TRANS_BLOCKS;
2846 } else {
2847 /*
2848 * Fast symlink. We have to add entry to directory
2849 * (EXT4_DATA_TRANS_BLOCKS + EXT4_INDEX_EXTRA_TRANS_BLOCKS),
2850 * allocate new inode (bitmap, group descriptor, inode block,
2851 * quota blocks, sb is already counted in previous macros).
2852 */
2853 credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2854 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3;
2855 }
2856retry:
2857 inode = ext4_new_inode_start_handle(dir, S_IFLNK|S_IRWXUGO,
2858 &dentry->d_name, 0, NULL,
2859 EXT4_HT_DIR, credits);
2860 handle = ext4_journal_current_handle();
2861 err = PTR_ERR(inode);
2862 if (IS_ERR(inode))
2863 goto out_stop;
2864
2865 if (l > EXT4_N_BLOCKS * 4) {
2866 inode->i_op = &ext4_symlink_inode_operations;
2867 ext4_set_aops(inode);
2868 /*
2869 * We cannot call page_symlink() with transaction started
2870 * because it calls into ext4_write_begin() which can wait
2871 * for transaction commit if we are running out of space
2872 * and thus we deadlock. So we have to stop transaction now
2873 * and restart it when symlink contents is written.
2874 *
2875 * To keep fs consistent in case of crash, we have to put inode
2876 * to orphan list in the mean time.
2877 */
2878 drop_nlink(inode);
2879 err = ext4_orphan_add(handle, inode);
2880 ext4_journal_stop(handle);
2881 if (err)
2882 goto err_drop_inode;
2883 err = __page_symlink(inode, symname, l, 1);
2884 if (err)
2885 goto err_drop_inode;
2886 /*
2887 * Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS
2888 * + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified
2889 */
2890 handle = ext4_journal_start(dir, EXT4_HT_DIR,
2891 EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2892 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1);
2893 if (IS_ERR(handle)) {
2894 err = PTR_ERR(handle);
2895 goto err_drop_inode;
2896 }
2897 set_nlink(inode, 1);
2898 err = ext4_orphan_del(handle, inode);
2899 if (err) {
2900 ext4_journal_stop(handle);
2901 clear_nlink(inode);
2902 goto err_drop_inode;
2903 }
2904 } else {
2905 /* clear the extent format for fast symlink */
2906 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
2907 inode->i_op = &ext4_fast_symlink_inode_operations;
2908 memcpy((char *)&EXT4_I(inode)->i_data, symname, l);
2909 inode->i_size = l-1;
2910 }
2911 EXT4_I(inode)->i_disksize = inode->i_size;
2912 err = ext4_add_nondir(handle, dentry, inode);
2913 if (!err && IS_DIRSYNC(dir))
2914 ext4_handle_sync(handle);
2915
2916out_stop:
2917 if (handle)
2918 ext4_journal_stop(handle);
2919 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2920 goto retry;
2921 return err;
2922err_drop_inode:
2923 unlock_new_inode(inode);
2924 iput(inode);
2925 return err;
2926}
2927
2928static int ext4_link(struct dentry *old_dentry,
2929 struct inode *dir, struct dentry *dentry)
2930{
2931 handle_t *handle;
2932 struct inode *inode = old_dentry->d_inode;
2933 int err, retries = 0;
2934
2935 if (inode->i_nlink >= EXT4_LINK_MAX)
2936 return -EMLINK;
2937
2938 dquot_initialize(dir);
2939
2940retry:
2941 handle = ext4_journal_start(dir, EXT4_HT_DIR,
2942 (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2943 EXT4_INDEX_EXTRA_TRANS_BLOCKS) + 1);
2944 if (IS_ERR(handle))
2945 return PTR_ERR(handle);
2946
2947 if (IS_DIRSYNC(dir))
2948 ext4_handle_sync(handle);
2949
2950 inode->i_ctime = ext4_current_time(inode);
2951 ext4_inc_count(handle, inode);
2952 ihold(inode);
2953
2954 err = ext4_add_entry(handle, dentry, inode);
2955 if (!err) {
2956 ext4_mark_inode_dirty(handle, inode);
2957 /* this can happen only for tmpfile being
2958 * linked the first time
2959 */
2960 if (inode->i_nlink == 1)
2961 ext4_orphan_del(handle, inode);
2962 d_instantiate(dentry, inode);
2963 } else {
2964 drop_nlink(inode);
2965 iput(inode);
2966 }
2967 ext4_journal_stop(handle);
2968 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2969 goto retry;
2970 return err;
2971}
2972
2973
2974/*
2975 * Try to find buffer head where contains the parent block.
2976 * It should be the inode block if it is inlined or the 1st block
2977 * if it is a normal dir.
2978 */
2979static struct buffer_head *ext4_get_first_dir_block(handle_t *handle,
2980 struct inode *inode,
2981 int *retval,
2982 struct ext4_dir_entry_2 **parent_de,
2983 int *inlined)
2984{
2985 struct buffer_head *bh;
2986
2987 if (!ext4_has_inline_data(inode)) {
2988 bh = ext4_read_dirblock(inode, 0, EITHER);
2989 if (IS_ERR(bh)) {
2990 *retval = PTR_ERR(bh);
2991 return NULL;
2992 }
2993 *parent_de = ext4_next_entry(
2994 (struct ext4_dir_entry_2 *)bh->b_data,
2995 inode->i_sb->s_blocksize);
2996 return bh;
2997 }
2998
2999 *inlined = 1;
3000 return ext4_get_first_inline_block(inode, parent_de, retval);
3001}
3002
3003struct ext4_renament {
3004 struct inode *dir;
3005 struct dentry *dentry;
3006 struct inode *inode;
3007 bool is_dir;
3008 int dir_nlink_delta;
3009
3010 /* entry for "dentry" */
3011 struct buffer_head *bh;
3012 struct ext4_dir_entry_2 *de;
3013 int inlined;
3014
3015 /* entry for ".." in inode if it's a directory */
3016 struct buffer_head *dir_bh;
3017 struct ext4_dir_entry_2 *parent_de;
3018 int dir_inlined;
3019};
3020
3021static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent)
3022{
3023 int retval;
3024
3025 ent->dir_bh = ext4_get_first_dir_block(handle, ent->inode,
3026 &retval, &ent->parent_de,
3027 &ent->dir_inlined);
3028 if (!ent->dir_bh)
3029 return retval;
3030 if (le32_to_cpu(ent->parent_de->inode) != ent->dir->i_ino)
3031 return -EIO;
3032 BUFFER_TRACE(ent->dir_bh, "get_write_access");
3033 return ext4_journal_get_write_access(handle, ent->dir_bh);
3034}
3035
3036static int ext4_rename_dir_finish(handle_t *handle, struct ext4_renament *ent,
3037 unsigned dir_ino)
3038{
3039 int retval;
3040
3041 ent->parent_de->inode = cpu_to_le32(dir_ino);
3042 BUFFER_TRACE(ent->dir_bh, "call ext4_handle_dirty_metadata");
3043 if (!ent->dir_inlined) {
3044 if (is_dx(ent->inode)) {
3045 retval = ext4_handle_dirty_dx_node(handle,
3046 ent->inode,
3047 ent->dir_bh);
3048 } else {
3049 retval = ext4_handle_dirty_dirent_node(handle,
3050 ent->inode,
3051 ent->dir_bh);
3052 }
3053 } else {
3054 retval = ext4_mark_inode_dirty(handle, ent->inode);
3055 }
3056 if (retval) {
3057 ext4_std_error(ent->dir->i_sb, retval);
3058 return retval;
3059 }
3060 return 0;
3061}
3062
3063static int ext4_setent(handle_t *handle, struct ext4_renament *ent,
3064 unsigned ino, unsigned file_type)
3065{
3066 int retval;
3067
3068 BUFFER_TRACE(ent->bh, "get write access");
3069 retval = ext4_journal_get_write_access(handle, ent->bh);
3070 if (retval)
3071 return retval;
3072 ent->de->inode = cpu_to_le32(ino);
3073 if (EXT4_HAS_INCOMPAT_FEATURE(ent->dir->i_sb,
3074 EXT4_FEATURE_INCOMPAT_FILETYPE))
3075 ent->de->file_type = file_type;
3076 ent->dir->i_version++;
3077 ent->dir->i_ctime = ent->dir->i_mtime =
3078 ext4_current_time(ent->dir);
3079 ext4_mark_inode_dirty(handle, ent->dir);
3080 BUFFER_TRACE(ent->bh, "call ext4_handle_dirty_metadata");
3081 if (!ent->inlined) {
3082 retval = ext4_handle_dirty_dirent_node(handle,
3083 ent->dir, ent->bh);
3084 if (unlikely(retval)) {
3085 ext4_std_error(ent->dir->i_sb, retval);
3086 return retval;
3087 }
3088 }
3089 brelse(ent->bh);
3090 ent->bh = NULL;
3091
3092 return 0;
3093}
3094
3095static int ext4_find_delete_entry(handle_t *handle, struct inode *dir,
3096 const struct qstr *d_name)
3097{
3098 int retval = -ENOENT;
3099 struct buffer_head *bh;
3100 struct ext4_dir_entry_2 *de;
3101
3102 bh = ext4_find_entry(dir, d_name, &de, NULL);
3103 if (bh) {
3104 retval = ext4_delete_entry(handle, dir, de, bh);
3105 brelse(bh);
3106 }
3107 return retval;
3108}
3109
3110static void ext4_rename_delete(handle_t *handle, struct ext4_renament *ent)
3111{
3112 int retval;
3113 /*
3114 * ent->de could have moved from under us during htree split, so make
3115 * sure that we are deleting the right entry. We might also be pointing
3116 * to a stale entry in the unused part of ent->bh so just checking inum
3117 * and the name isn't enough.
3118 */
3119 if (le32_to_cpu(ent->de->inode) != ent->inode->i_ino ||
3120 ent->de->name_len != ent->dentry->d_name.len ||
3121 strncmp(ent->de->name, ent->dentry->d_name.name,
3122 ent->de->name_len)) {
3123 retval = ext4_find_delete_entry(handle, ent->dir,
3124 &ent->dentry->d_name);
3125 } else {
3126 retval = ext4_delete_entry(handle, ent->dir, ent->de, ent->bh);
3127 if (retval == -ENOENT) {
3128 retval = ext4_find_delete_entry(handle, ent->dir,
3129 &ent->dentry->d_name);
3130 }
3131 }
3132
3133 if (retval) {
3134 ext4_warning(ent->dir->i_sb,
3135 "Deleting old file (%lu), %d, error=%d",
3136 ent->dir->i_ino, ent->dir->i_nlink, retval);
3137 }
3138}
3139
3140static void ext4_update_dir_count(handle_t *handle, struct ext4_renament *ent)
3141{
3142 if (ent->dir_nlink_delta) {
3143 if (ent->dir_nlink_delta == -1)
3144 ext4_dec_count(handle, ent->dir);
3145 else
3146 ext4_inc_count(handle, ent->dir);
3147 ext4_mark_inode_dirty(handle, ent->dir);
3148 }
3149}
3150
3151/*
3152 * Anybody can rename anything with this: the permission checks are left to the
3153 * higher-level routines.
3154 *
3155 * n.b. old_{dentry,inode) refers to the source dentry/inode
3156 * while new_{dentry,inode) refers to the destination dentry/inode
3157 * This comes from rename(const char *oldpath, const char *newpath)
3158 */
3159static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
3160 struct inode *new_dir, struct dentry *new_dentry)
3161{
3162 handle_t *handle = NULL;
3163 struct ext4_renament old = {
3164 .dir = old_dir,
3165 .dentry = old_dentry,
3166 .inode = old_dentry->d_inode,
3167 };
3168 struct ext4_renament new = {
3169 .dir = new_dir,
3170 .dentry = new_dentry,
3171 .inode = new_dentry->d_inode,
3172 };
3173 int retval;
3174
3175 dquot_initialize(old.dir);
3176 dquot_initialize(new.dir);
3177
3178 /* Initialize quotas before so that eventual writes go
3179 * in separate transaction */
3180 if (new.inode)
3181 dquot_initialize(new.inode);
3182
3183 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, NULL);
3184 /*
3185 * Check for inode number is _not_ due to possible IO errors.
3186 * We might rmdir the source, keep it as pwd of some process
3187 * and merrily kill the link to whatever was created under the
3188 * same name. Goodbye sticky bit ;-<
3189 */
3190 retval = -ENOENT;
3191 if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3192 goto end_rename;
3193
3194 new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
3195 &new.de, &new.inlined);
3196 if (new.bh) {
3197 if (!new.inode) {
3198 brelse(new.bh);
3199 new.bh = NULL;
3200 }
3201 }
3202 if (new.inode && !test_opt(new.dir->i_sb, NO_AUTO_DA_ALLOC))
3203 ext4_alloc_da_blocks(old.inode);
3204
3205 handle = ext4_journal_start(old.dir, EXT4_HT_DIR,
3206 (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3207 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2));
3208 if (IS_ERR(handle))
3209 return PTR_ERR(handle);
3210
3211 if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3212 ext4_handle_sync(handle);
3213
3214 if (S_ISDIR(old.inode->i_mode)) {
3215 if (new.inode) {
3216 retval = -ENOTEMPTY;
3217 if (!empty_dir(new.inode))
3218 goto end_rename;
3219 } else {
3220 retval = -EMLINK;
3221 if (new.dir != old.dir && EXT4_DIR_LINK_MAX(new.dir))
3222 goto end_rename;
3223 }
3224 retval = ext4_rename_dir_prepare(handle, &old);
3225 if (retval)
3226 goto end_rename;
3227 }
3228 if (!new.bh) {
3229 retval = ext4_add_entry(handle, new.dentry, old.inode);
3230 if (retval)
3231 goto end_rename;
3232 } else {
3233 retval = ext4_setent(handle, &new,
3234 old.inode->i_ino, old.de->file_type);
3235 if (retval)
3236 goto end_rename;
3237 }
3238
3239 /*
3240 * Like most other Unix systems, set the ctime for inodes on a
3241 * rename.
3242 */
3243 old.inode->i_ctime = ext4_current_time(old.inode);
3244 ext4_mark_inode_dirty(handle, old.inode);
3245
3246 /*
3247 * ok, that's it
3248 */
3249 ext4_rename_delete(handle, &old);
3250
3251 if (new.inode) {
3252 ext4_dec_count(handle, new.inode);
3253 new.inode->i_ctime = ext4_current_time(new.inode);
3254 }
3255 old.dir->i_ctime = old.dir->i_mtime = ext4_current_time(old.dir);
3256 ext4_update_dx_flag(old.dir);
3257 if (old.dir_bh) {
3258 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
3259 if (retval)
3260 goto end_rename;
3261
3262 ext4_dec_count(handle, old.dir);
3263 if (new.inode) {
3264 /* checked empty_dir above, can't have another parent,
3265 * ext4_dec_count() won't work for many-linked dirs */
3266 clear_nlink(new.inode);
3267 } else {
3268 ext4_inc_count(handle, new.dir);
3269 ext4_update_dx_flag(new.dir);
3270 ext4_mark_inode_dirty(handle, new.dir);
3271 }
3272 }
3273 ext4_mark_inode_dirty(handle, old.dir);
3274 if (new.inode) {
3275 ext4_mark_inode_dirty(handle, new.inode);
3276 if (!new.inode->i_nlink)
3277 ext4_orphan_add(handle, new.inode);
3278 }
3279 retval = 0;
3280
3281end_rename:
3282 brelse(old.dir_bh);
3283 brelse(old.bh);
3284 brelse(new.bh);
3285 if (handle)
3286 ext4_journal_stop(handle);
3287 return retval;
3288}
3289
3290static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
3291 struct inode *new_dir, struct dentry *new_dentry)
3292{
3293 handle_t *handle = NULL;
3294 struct ext4_renament old = {
3295 .dir = old_dir,
3296 .dentry = old_dentry,
3297 .inode = old_dentry->d_inode,
3298 };
3299 struct ext4_renament new = {
3300 .dir = new_dir,
3301 .dentry = new_dentry,
3302 .inode = new_dentry->d_inode,
3303 };
3304 u8 new_file_type;
3305 int retval;
3306
3307 dquot_initialize(old.dir);
3308 dquot_initialize(new.dir);
3309
3310 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name,
3311 &old.de, &old.inlined);
3312 /*
3313 * Check for inode number is _not_ due to possible IO errors.
3314 * We might rmdir the source, keep it as pwd of some process
3315 * and merrily kill the link to whatever was created under the
3316 * same name. Goodbye sticky bit ;-<
3317 */
3318 retval = -ENOENT;
3319 if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3320 goto end_rename;
3321
3322 new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
3323 &new.de, &new.inlined);
3324
3325 /* RENAME_EXCHANGE case: old *and* new must both exist */
3326 if (!new.bh || le32_to_cpu(new.de->inode) != new.inode->i_ino)
3327 goto end_rename;
3328
3329 handle = ext4_journal_start(old.dir, EXT4_HT_DIR,
3330 (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3331 2 * EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2));
3332 if (IS_ERR(handle))
3333 return PTR_ERR(handle);
3334
3335 if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3336 ext4_handle_sync(handle);
3337
3338 if (S_ISDIR(old.inode->i_mode)) {
3339 old.is_dir = true;
3340 retval = ext4_rename_dir_prepare(handle, &old);
3341 if (retval)
3342 goto end_rename;
3343 }
3344 if (S_ISDIR(new.inode->i_mode)) {
3345 new.is_dir = true;
3346 retval = ext4_rename_dir_prepare(handle, &new);
3347 if (retval)
3348 goto end_rename;
3349 }
3350
3351 /*
3352 * Other than the special case of overwriting a directory, parents'
3353 * nlink only needs to be modified if this is a cross directory rename.
3354 */
3355 if (old.dir != new.dir && old.is_dir != new.is_dir) {
3356 old.dir_nlink_delta = old.is_dir ? -1 : 1;
3357 new.dir_nlink_delta = -old.dir_nlink_delta;
3358 retval = -EMLINK;
3359 if ((old.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(old.dir)) ||
3360 (new.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(new.dir)))
3361 goto end_rename;
3362 }
3363
3364 new_file_type = new.de->file_type;
3365 retval = ext4_setent(handle, &new, old.inode->i_ino, old.de->file_type);
3366 if (retval)
3367 goto end_rename;
3368
3369 retval = ext4_setent(handle, &old, new.inode->i_ino, new_file_type);
3370 if (retval)
3371 goto end_rename;
3372
3373 /*
3374 * Like most other Unix systems, set the ctime for inodes on a
3375 * rename.
3376 */
3377 old.inode->i_ctime = ext4_current_time(old.inode);
3378 new.inode->i_ctime = ext4_current_time(new.inode);
3379 ext4_mark_inode_dirty(handle, old.inode);
3380 ext4_mark_inode_dirty(handle, new.inode);
3381
3382 if (old.dir_bh) {
3383 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
3384 if (retval)
3385 goto end_rename;
3386 }
3387 if (new.dir_bh) {
3388 retval = ext4_rename_dir_finish(handle, &new, old.dir->i_ino);
3389 if (retval)
3390 goto end_rename;
3391 }
3392 ext4_update_dir_count(handle, &old);
3393 ext4_update_dir_count(handle, &new);
3394 retval = 0;
3395
3396end_rename:
3397 brelse(old.dir_bh);
3398 brelse(new.dir_bh);
3399 brelse(old.bh);
3400 brelse(new.bh);
3401 if (handle)
3402 ext4_journal_stop(handle);
3403 return retval;
3404}
3405
3406static int ext4_rename2(struct inode *old_dir, struct dentry *old_dentry,
3407 struct inode *new_dir, struct dentry *new_dentry,
3408 unsigned int flags)
3409{
3410 if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE))
3411 return -EINVAL;
3412
3413 if (flags & RENAME_EXCHANGE) {
3414 return ext4_cross_rename(old_dir, old_dentry,
3415 new_dir, new_dentry);
3416 }
3417 /*
3418 * Existence checking was done by the VFS, otherwise "RENAME_NOREPLACE"
3419 * is equivalent to regular rename.
3420 */
3421 return ext4_rename(old_dir, old_dentry, new_dir, new_dentry);
3422}
3423
3424/*
3425 * directories can handle most operations...
3426 */
3427const struct inode_operations ext4_dir_inode_operations = {
3428 .create = ext4_create,
3429 .lookup = ext4_lookup,
3430 .link = ext4_link,
3431 .unlink = ext4_unlink,
3432 .symlink = ext4_symlink,
3433 .mkdir = ext4_mkdir,
3434 .rmdir = ext4_rmdir,
3435 .mknod = ext4_mknod,
3436 .tmpfile = ext4_tmpfile,
3437 .rename = ext4_rename,
3438 .rename2 = ext4_rename2,
3439 .setattr = ext4_setattr,
3440 .setxattr = generic_setxattr,
3441 .getxattr = generic_getxattr,
3442 .listxattr = ext4_listxattr,
3443 .removexattr = generic_removexattr,
3444 .get_acl = ext4_get_acl,
3445 .set_acl = ext4_set_acl,
3446 .fiemap = ext4_fiemap,
3447};
3448
3449const struct inode_operations ext4_special_inode_operations = {
3450 .setattr = ext4_setattr,
3451 .setxattr = generic_setxattr,
3452 .getxattr = generic_getxattr,
3453 .listxattr = ext4_listxattr,
3454 .removexattr = generic_removexattr,
3455 .get_acl = ext4_get_acl,
3456 .set_acl = ext4_set_acl,
3457};