libata: fix NULL sdev dereference race in atapi_qc_complete()
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / ext4 / namei.c
blobc3b6ad0fcc46628e978869f80d5ef343b904d0d5
1 /*
2 * linux/fs/ext4/namei.c
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)
9 * from
11 * linux/fs/minix/namei.c
13 * Copyright (C) 1991, 1992 Linus Torvalds
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
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"
40 #include "xattr.h"
41 #include "acl.h"
44 * define how far ahead to read directories while searching them.
46 #define NAMEI_RA_CHUNKS 2
47 #define NAMEI_RA_BLOCKS 4
48 #define NAMEI_RA_SIZE (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS)
49 #define NAMEI_RA_INDEX(c,b) (((c) * NAMEI_RA_BLOCKS) + (b))
51 static struct buffer_head *ext4_append(handle_t *handle,
52 struct inode *inode,
53 ext4_lblk_t *block, int *err)
55 struct buffer_head *bh;
57 *block = inode->i_size >> inode->i_sb->s_blocksize_bits;
59 bh = ext4_bread(handle, inode, *block, 1, err);
60 if (bh) {
61 inode->i_size += inode->i_sb->s_blocksize;
62 EXT4_I(inode)->i_disksize = inode->i_size;
63 *err = ext4_journal_get_write_access(handle, bh);
64 if (*err) {
65 brelse(bh);
66 bh = NULL;
69 return bh;
72 #ifndef assert
73 #define assert(test) J_ASSERT(test)
74 #endif
76 #ifdef DX_DEBUG
77 #define dxtrace(command) command
78 #else
79 #define dxtrace(command)
80 #endif
82 struct fake_dirent
84 __le32 inode;
85 __le16 rec_len;
86 u8 name_len;
87 u8 file_type;
90 struct dx_countlimit
92 __le16 limit;
93 __le16 count;
96 struct dx_entry
98 __le32 hash;
99 __le32 block;
103 * dx_root_info is laid out so that if it should somehow get overlaid by a
104 * dirent the two low bits of the hash version will be zero. Therefore, the
105 * hash version mod 4 should never be 0. Sincerely, the paranoia department.
108 struct dx_root
110 struct fake_dirent dot;
111 char dot_name[4];
112 struct fake_dirent dotdot;
113 char dotdot_name[4];
114 struct dx_root_info
116 __le32 reserved_zero;
117 u8 hash_version;
118 u8 info_length; /* 8 */
119 u8 indirect_levels;
120 u8 unused_flags;
122 info;
123 struct dx_entry entries[0];
126 struct dx_node
128 struct fake_dirent fake;
129 struct dx_entry entries[0];
133 struct dx_frame
135 struct buffer_head *bh;
136 struct dx_entry *entries;
137 struct dx_entry *at;
140 struct dx_map_entry
142 u32 hash;
143 u16 offs;
144 u16 size;
147 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
148 static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
149 static inline unsigned dx_get_hash(struct dx_entry *entry);
150 static void dx_set_hash(struct dx_entry *entry, unsigned value);
151 static unsigned dx_get_count(struct dx_entry *entries);
152 static unsigned dx_get_limit(struct dx_entry *entries);
153 static void dx_set_count(struct dx_entry *entries, unsigned value);
154 static void dx_set_limit(struct dx_entry *entries, unsigned value);
155 static unsigned dx_root_limit(struct inode *dir, unsigned infosize);
156 static unsigned dx_node_limit(struct inode *dir);
157 static struct dx_frame *dx_probe(const struct qstr *d_name,
158 struct inode *dir,
159 struct dx_hash_info *hinfo,
160 struct dx_frame *frame,
161 int *err);
162 static void dx_release(struct dx_frame *frames);
163 static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize,
164 struct dx_hash_info *hinfo, struct dx_map_entry map[]);
165 static void dx_sort_map(struct dx_map_entry *map, unsigned count);
166 static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to,
167 struct dx_map_entry *offsets, int count, unsigned blocksize);
168 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize);
169 static void dx_insert_block(struct dx_frame *frame,
170 u32 hash, ext4_lblk_t block);
171 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
172 struct dx_frame *frame,
173 struct dx_frame *frames,
174 __u32 *start_hash);
175 static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
176 const struct qstr *d_name,
177 struct ext4_dir_entry_2 **res_dir,
178 int *err);
179 static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
180 struct inode *inode);
182 unsigned int ext4_rec_len_from_disk(__le16 dlen, unsigned blocksize)
184 unsigned len = le16_to_cpu(dlen);
186 if (len == EXT4_MAX_REC_LEN || len == 0)
187 return blocksize;
188 return (len & 65532) | ((len & 3) << 16);
191 __le16 ext4_rec_len_to_disk(unsigned len, unsigned blocksize)
193 if ((len > blocksize) || (blocksize > (1 << 18)) || (len & 3))
194 BUG();
195 if (len < 65536)
196 return cpu_to_le16(len);
197 if (len == blocksize) {
198 if (blocksize == 65536)
199 return cpu_to_le16(EXT4_MAX_REC_LEN);
200 else
201 return cpu_to_le16(0);
203 return cpu_to_le16((len & 65532) | ((len >> 16) & 3));
207 * p is at least 6 bytes before the end of page
209 static inline struct ext4_dir_entry_2 *
210 ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
212 return (struct ext4_dir_entry_2 *)((char *)p +
213 ext4_rec_len_from_disk(p->rec_len, blocksize));
217 * Future: use high four bits of block for coalesce-on-delete flags
218 * Mask them off for now.
221 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
223 return le32_to_cpu(entry->block) & 0x00ffffff;
226 static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
228 entry->block = cpu_to_le32(value);
231 static inline unsigned dx_get_hash(struct dx_entry *entry)
233 return le32_to_cpu(entry->hash);
236 static inline void dx_set_hash(struct dx_entry *entry, unsigned value)
238 entry->hash = cpu_to_le32(value);
241 static inline unsigned dx_get_count(struct dx_entry *entries)
243 return le16_to_cpu(((struct dx_countlimit *) entries)->count);
246 static inline unsigned dx_get_limit(struct dx_entry *entries)
248 return le16_to_cpu(((struct dx_countlimit *) entries)->limit);
251 static inline void dx_set_count(struct dx_entry *entries, unsigned value)
253 ((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
256 static inline void dx_set_limit(struct dx_entry *entries, unsigned value)
258 ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
261 static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
263 unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
264 EXT4_DIR_REC_LEN(2) - infosize;
265 return entry_space / sizeof(struct dx_entry);
268 static inline unsigned dx_node_limit(struct inode *dir)
270 unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);
271 return entry_space / sizeof(struct dx_entry);
275 * Debug
277 #ifdef DX_DEBUG
278 static void dx_show_index(char * label, struct dx_entry *entries)
280 int i, n = dx_get_count (entries);
281 printk(KERN_DEBUG "%s index ", label);
282 for (i = 0; i < n; i++) {
283 printk("%x->%lu ", i ? dx_get_hash(entries + i) :
284 0, (unsigned long)dx_get_block(entries + i));
286 printk("\n");
289 struct stats
291 unsigned names;
292 unsigned space;
293 unsigned bcount;
296 static struct stats dx_show_leaf(struct dx_hash_info *hinfo, struct ext4_dir_entry_2 *de,
297 int size, int show_names)
299 unsigned names = 0, space = 0;
300 char *base = (char *) de;
301 struct dx_hash_info h = *hinfo;
303 printk("names: ");
304 while ((char *) de < base + size)
306 if (de->inode)
308 if (show_names)
310 int len = de->name_len;
311 char *name = de->name;
312 while (len--) printk("%c", *name++);
313 ext4fs_dirhash(de->name, de->name_len, &h);
314 printk(":%x.%u ", h.hash,
315 ((char *) de - base));
317 space += EXT4_DIR_REC_LEN(de->name_len);
318 names++;
320 de = ext4_next_entry(de, size);
322 printk("(%i)\n", names);
323 return (struct stats) { names, space, 1 };
326 struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
327 struct dx_entry *entries, int levels)
329 unsigned blocksize = dir->i_sb->s_blocksize;
330 unsigned count = dx_get_count(entries), names = 0, space = 0, i;
331 unsigned bcount = 0;
332 struct buffer_head *bh;
333 int err;
334 printk("%i indexed blocks...\n", count);
335 for (i = 0; i < count; i++, entries++)
337 ext4_lblk_t block = dx_get_block(entries);
338 ext4_lblk_t hash = i ? dx_get_hash(entries): 0;
339 u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
340 struct stats stats;
341 printk("%s%3u:%03u hash %8x/%8x ",levels?"":" ", i, block, hash, range);
342 if (!(bh = ext4_bread (NULL,dir, block, 0,&err))) continue;
343 stats = levels?
344 dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
345 dx_show_leaf(hinfo, (struct ext4_dir_entry_2 *) bh->b_data, blocksize, 0);
346 names += stats.names;
347 space += stats.space;
348 bcount += stats.bcount;
349 brelse(bh);
351 if (bcount)
352 printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n",
353 levels ? "" : " ", names, space/bcount,
354 (space/bcount)*100/blocksize);
355 return (struct stats) { names, space, bcount};
357 #endif /* DX_DEBUG */
360 * Probe for a directory leaf block to search.
362 * dx_probe can return ERR_BAD_DX_DIR, which means there was a format
363 * error in the directory index, and the caller should fall back to
364 * searching the directory normally. The callers of dx_probe **MUST**
365 * check for this error code, and make sure it never gets reflected
366 * back to userspace.
368 static struct dx_frame *
369 dx_probe(const struct qstr *d_name, struct inode *dir,
370 struct dx_hash_info *hinfo, struct dx_frame *frame_in, int *err)
372 unsigned count, indirect;
373 struct dx_entry *at, *entries, *p, *q, *m;
374 struct dx_root *root;
375 struct buffer_head *bh;
376 struct dx_frame *frame = frame_in;
377 u32 hash;
379 frame->bh = NULL;
380 if (!(bh = ext4_bread (NULL,dir, 0, 0, err)))
381 goto fail;
382 root = (struct dx_root *) bh->b_data;
383 if (root->info.hash_version != DX_HASH_TEA &&
384 root->info.hash_version != DX_HASH_HALF_MD4 &&
385 root->info.hash_version != DX_HASH_LEGACY) {
386 ext4_warning(dir->i_sb, __func__,
387 "Unrecognised inode hash code %d",
388 root->info.hash_version);
389 brelse(bh);
390 *err = ERR_BAD_DX_DIR;
391 goto fail;
393 hinfo->hash_version = root->info.hash_version;
394 if (hinfo->hash_version <= DX_HASH_TEA)
395 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
396 hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
397 if (d_name)
398 ext4fs_dirhash(d_name->name, d_name->len, hinfo);
399 hash = hinfo->hash;
401 if (root->info.unused_flags & 1) {
402 ext4_warning(dir->i_sb, __func__,
403 "Unimplemented inode hash flags: %#06x",
404 root->info.unused_flags);
405 brelse(bh);
406 *err = ERR_BAD_DX_DIR;
407 goto fail;
410 if ((indirect = root->info.indirect_levels) > 1) {
411 ext4_warning(dir->i_sb, __func__,
412 "Unimplemented inode hash depth: %#06x",
413 root->info.indirect_levels);
414 brelse(bh);
415 *err = ERR_BAD_DX_DIR;
416 goto fail;
419 entries = (struct dx_entry *) (((char *)&root->info) +
420 root->info.info_length);
422 if (dx_get_limit(entries) != dx_root_limit(dir,
423 root->info.info_length)) {
424 ext4_warning(dir->i_sb, __func__,
425 "dx entry: limit != root limit");
426 brelse(bh);
427 *err = ERR_BAD_DX_DIR;
428 goto fail;
431 dxtrace(printk("Look up %x", hash));
432 while (1)
434 count = dx_get_count(entries);
435 if (!count || count > dx_get_limit(entries)) {
436 ext4_warning(dir->i_sb, __func__,
437 "dx entry: no count or count > limit");
438 brelse(bh);
439 *err = ERR_BAD_DX_DIR;
440 goto fail2;
443 p = entries + 1;
444 q = entries + count - 1;
445 while (p <= q)
447 m = p + (q - p)/2;
448 dxtrace(printk("."));
449 if (dx_get_hash(m) > hash)
450 q = m - 1;
451 else
452 p = m + 1;
455 if (0) // linear search cross check
457 unsigned n = count - 1;
458 at = entries;
459 while (n--)
461 dxtrace(printk(","));
462 if (dx_get_hash(++at) > hash)
464 at--;
465 break;
468 assert (at == p - 1);
471 at = p - 1;
472 dxtrace(printk(" %x->%u\n", at == entries? 0: dx_get_hash(at), dx_get_block(at)));
473 frame->bh = bh;
474 frame->entries = entries;
475 frame->at = at;
476 if (!indirect--) return frame;
477 if (!(bh = ext4_bread (NULL,dir, dx_get_block(at), 0, err)))
478 goto fail2;
479 at = entries = ((struct dx_node *) bh->b_data)->entries;
480 if (dx_get_limit(entries) != dx_node_limit (dir)) {
481 ext4_warning(dir->i_sb, __func__,
482 "dx entry: limit != node limit");
483 brelse(bh);
484 *err = ERR_BAD_DX_DIR;
485 goto fail2;
487 frame++;
488 frame->bh = NULL;
490 fail2:
491 while (frame >= frame_in) {
492 brelse(frame->bh);
493 frame--;
495 fail:
496 if (*err == ERR_BAD_DX_DIR)
497 ext4_warning(dir->i_sb, __func__,
498 "Corrupt dir inode %ld, running e2fsck is "
499 "recommended.", dir->i_ino);
500 return NULL;
503 static void dx_release (struct dx_frame *frames)
505 if (frames[0].bh == NULL)
506 return;
508 if (((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels)
509 brelse(frames[1].bh);
510 brelse(frames[0].bh);
514 * This function increments the frame pointer to search the next leaf
515 * block, and reads in the necessary intervening nodes if the search
516 * should be necessary. Whether or not the search is necessary is
517 * controlled by the hash parameter. If the hash value is even, then
518 * the search is only continued if the next block starts with that
519 * hash value. This is used if we are searching for a specific file.
521 * If the hash value is HASH_NB_ALWAYS, then always go to the next block.
523 * This function returns 1 if the caller should continue to search,
524 * or 0 if it should not. If there is an error reading one of the
525 * index blocks, it will a negative error code.
527 * If start_hash is non-null, it will be filled in with the starting
528 * hash of the next page.
530 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
531 struct dx_frame *frame,
532 struct dx_frame *frames,
533 __u32 *start_hash)
535 struct dx_frame *p;
536 struct buffer_head *bh;
537 int err, num_frames = 0;
538 __u32 bhash;
540 p = frame;
542 * Find the next leaf page by incrementing the frame pointer.
543 * If we run out of entries in the interior node, loop around and
544 * increment pointer in the parent node. When we break out of
545 * this loop, num_frames indicates the number of interior
546 * nodes need to be read.
548 while (1) {
549 if (++(p->at) < p->entries + dx_get_count(p->entries))
550 break;
551 if (p == frames)
552 return 0;
553 num_frames++;
554 p--;
558 * If the hash is 1, then continue only if the next page has a
559 * continuation hash of any value. This is used for readdir
560 * handling. Otherwise, check to see if the hash matches the
561 * desired contiuation hash. If it doesn't, return since
562 * there's no point to read in the successive index pages.
564 bhash = dx_get_hash(p->at);
565 if (start_hash)
566 *start_hash = bhash;
567 if ((hash & 1) == 0) {
568 if ((bhash & ~1) != hash)
569 return 0;
572 * If the hash is HASH_NB_ALWAYS, we always go to the next
573 * block so no check is necessary
575 while (num_frames--) {
576 if (!(bh = ext4_bread(NULL, dir, dx_get_block(p->at),
577 0, &err)))
578 return err; /* Failure */
579 p++;
580 brelse(p->bh);
581 p->bh = bh;
582 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
584 return 1;
589 * This function fills a red-black tree with information from a
590 * directory block. It returns the number directory entries loaded
591 * into the tree. If there is an error it is returned in err.
593 static int htree_dirblock_to_tree(struct file *dir_file,
594 struct inode *dir, ext4_lblk_t block,
595 struct dx_hash_info *hinfo,
596 __u32 start_hash, __u32 start_minor_hash)
598 struct buffer_head *bh;
599 struct ext4_dir_entry_2 *de, *top;
600 int err, count = 0;
602 dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
603 (unsigned long)block));
604 if (!(bh = ext4_bread (NULL, dir, block, 0, &err)))
605 return err;
607 de = (struct ext4_dir_entry_2 *) bh->b_data;
608 top = (struct ext4_dir_entry_2 *) ((char *) de +
609 dir->i_sb->s_blocksize -
610 EXT4_DIR_REC_LEN(0));
611 for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) {
612 if (!ext4_check_dir_entry("htree_dirblock_to_tree", dir, de, bh,
613 (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
614 +((char *)de - bh->b_data))) {
615 /* On error, skip the f_pos to the next block. */
616 dir_file->f_pos = (dir_file->f_pos |
617 (dir->i_sb->s_blocksize - 1)) + 1;
618 brelse(bh);
619 return count;
621 ext4fs_dirhash(de->name, de->name_len, hinfo);
622 if ((hinfo->hash < start_hash) ||
623 ((hinfo->hash == start_hash) &&
624 (hinfo->minor_hash < start_minor_hash)))
625 continue;
626 if (de->inode == 0)
627 continue;
628 if ((err = ext4_htree_store_dirent(dir_file,
629 hinfo->hash, hinfo->minor_hash, de)) != 0) {
630 brelse(bh);
631 return err;
633 count++;
635 brelse(bh);
636 return count;
641 * This function fills a red-black tree with information from a
642 * directory. We start scanning the directory in hash order, starting
643 * at start_hash and start_minor_hash.
645 * This function returns the number of entries inserted into the tree,
646 * or a negative error code.
648 int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
649 __u32 start_minor_hash, __u32 *next_hash)
651 struct dx_hash_info hinfo;
652 struct ext4_dir_entry_2 *de;
653 struct dx_frame frames[2], *frame;
654 struct inode *dir;
655 ext4_lblk_t block;
656 int count = 0;
657 int ret, err;
658 __u32 hashval;
660 dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
661 start_hash, start_minor_hash));
662 dir = dir_file->f_path.dentry->d_inode;
663 if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) {
664 hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
665 if (hinfo.hash_version <= DX_HASH_TEA)
666 hinfo.hash_version +=
667 EXT4_SB(dir->i_sb)->s_hash_unsigned;
668 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
669 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
670 start_hash, start_minor_hash);
671 *next_hash = ~0;
672 return count;
674 hinfo.hash = start_hash;
675 hinfo.minor_hash = 0;
676 frame = dx_probe(NULL, dir, &hinfo, frames, &err);
677 if (!frame)
678 return err;
680 /* Add '.' and '..' from the htree header */
681 if (!start_hash && !start_minor_hash) {
682 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
683 if ((err = ext4_htree_store_dirent(dir_file, 0, 0, de)) != 0)
684 goto errout;
685 count++;
687 if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
688 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
689 de = ext4_next_entry(de, dir->i_sb->s_blocksize);
690 if ((err = ext4_htree_store_dirent(dir_file, 2, 0, de)) != 0)
691 goto errout;
692 count++;
695 while (1) {
696 block = dx_get_block(frame->at);
697 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
698 start_hash, start_minor_hash);
699 if (ret < 0) {
700 err = ret;
701 goto errout;
703 count += ret;
704 hashval = ~0;
705 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
706 frame, frames, &hashval);
707 *next_hash = hashval;
708 if (ret < 0) {
709 err = ret;
710 goto errout;
713 * Stop if: (a) there are no more entries, or
714 * (b) we have inserted at least one entry and the
715 * next hash value is not a continuation
717 if ((ret == 0) ||
718 (count && ((hashval & 1) == 0)))
719 break;
721 dx_release(frames);
722 dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, "
723 "next hash: %x\n", count, *next_hash));
724 return count;
725 errout:
726 dx_release(frames);
727 return (err);
732 * Directory block splitting, compacting
736 * Create map of hash values, offsets, and sizes, stored at end of block.
737 * Returns number of entries mapped.
739 static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize,
740 struct dx_hash_info *hinfo,
741 struct dx_map_entry *map_tail)
743 int count = 0;
744 char *base = (char *) de;
745 struct dx_hash_info h = *hinfo;
747 while ((char *) de < base + blocksize) {
748 if (de->name_len && de->inode) {
749 ext4fs_dirhash(de->name, de->name_len, &h);
750 map_tail--;
751 map_tail->hash = h.hash;
752 map_tail->offs = ((char *) de - base)>>2;
753 map_tail->size = le16_to_cpu(de->rec_len);
754 count++;
755 cond_resched();
757 /* XXX: do we need to check rec_len == 0 case? -Chris */
758 de = ext4_next_entry(de, blocksize);
760 return count;
763 /* Sort map by hash value */
764 static void dx_sort_map (struct dx_map_entry *map, unsigned count)
766 struct dx_map_entry *p, *q, *top = map + count - 1;
767 int more;
768 /* Combsort until bubble sort doesn't suck */
769 while (count > 2) {
770 count = count*10/13;
771 if (count - 9 < 2) /* 9, 10 -> 11 */
772 count = 11;
773 for (p = top, q = p - count; q >= map; p--, q--)
774 if (p->hash < q->hash)
775 swap(*p, *q);
777 /* Garden variety bubble sort */
778 do {
779 more = 0;
780 q = top;
781 while (q-- > map) {
782 if (q[1].hash >= q[0].hash)
783 continue;
784 swap(*(q+1), *q);
785 more = 1;
787 } while(more);
790 static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
792 struct dx_entry *entries = frame->entries;
793 struct dx_entry *old = frame->at, *new = old + 1;
794 int count = dx_get_count(entries);
796 assert(count < dx_get_limit(entries));
797 assert(old < entries + count);
798 memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
799 dx_set_hash(new, hash);
800 dx_set_block(new, block);
801 dx_set_count(entries, count + 1);
804 static void ext4_update_dx_flag(struct inode *inode)
806 if (!EXT4_HAS_COMPAT_FEATURE(inode->i_sb,
807 EXT4_FEATURE_COMPAT_DIR_INDEX))
808 ext4_clear_inode_flag(inode, EXT4_INODE_INDEX);
812 * NOTE! unlike strncmp, ext4_match returns 1 for success, 0 for failure.
814 * `len <= EXT4_NAME_LEN' is guaranteed by caller.
815 * `de != NULL' is guaranteed by caller.
817 static inline int ext4_match (int len, const char * const name,
818 struct ext4_dir_entry_2 * de)
820 if (len != de->name_len)
821 return 0;
822 if (!de->inode)
823 return 0;
824 return !memcmp(name, de->name, len);
828 * Returns 0 if not found, -1 on failure, and 1 on success
830 static inline int search_dirblock(struct buffer_head *bh,
831 struct inode *dir,
832 const struct qstr *d_name,
833 unsigned int offset,
834 struct ext4_dir_entry_2 ** res_dir)
836 struct ext4_dir_entry_2 * de;
837 char * dlimit;
838 int de_len;
839 const char *name = d_name->name;
840 int namelen = d_name->len;
842 de = (struct ext4_dir_entry_2 *) bh->b_data;
843 dlimit = bh->b_data + dir->i_sb->s_blocksize;
844 while ((char *) de < dlimit) {
845 /* this code is executed quadratically often */
846 /* do minimal checking `by hand' */
848 if ((char *) de + namelen <= dlimit &&
849 ext4_match (namelen, name, de)) {
850 /* found a match - just to be sure, do a full check */
851 if (!ext4_check_dir_entry("ext4_find_entry",
852 dir, de, bh, offset))
853 return -1;
854 *res_dir = de;
855 return 1;
857 /* prevent looping on a bad block */
858 de_len = ext4_rec_len_from_disk(de->rec_len,
859 dir->i_sb->s_blocksize);
860 if (de_len <= 0)
861 return -1;
862 offset += de_len;
863 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
865 return 0;
870 * ext4_find_entry()
872 * finds an entry in the specified directory with the wanted name. It
873 * returns the cache buffer in which the entry was found, and the entry
874 * itself (as a parameter - res_dir). It does NOT read the inode of the
875 * entry - you'll have to do that yourself if you want to.
877 * The returned buffer_head has ->b_count elevated. The caller is expected
878 * to brelse() it when appropriate.
880 static struct buffer_head * ext4_find_entry (struct inode *dir,
881 const struct qstr *d_name,
882 struct ext4_dir_entry_2 ** res_dir)
884 struct super_block *sb;
885 struct buffer_head *bh_use[NAMEI_RA_SIZE];
886 struct buffer_head *bh, *ret = NULL;
887 ext4_lblk_t start, block, b;
888 int ra_max = 0; /* Number of bh's in the readahead
889 buffer, bh_use[] */
890 int ra_ptr = 0; /* Current index into readahead
891 buffer */
892 int num = 0;
893 ext4_lblk_t nblocks;
894 int i, err;
895 int namelen;
897 *res_dir = NULL;
898 sb = dir->i_sb;
899 namelen = d_name->len;
900 if (namelen > EXT4_NAME_LEN)
901 return NULL;
902 if (is_dx(dir)) {
903 bh = ext4_dx_find_entry(dir, d_name, res_dir, &err);
905 * On success, or if the error was file not found,
906 * return. Otherwise, fall back to doing a search the
907 * old fashioned way.
909 if (bh || (err != ERR_BAD_DX_DIR))
910 return bh;
911 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
912 "falling back\n"));
914 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
915 start = EXT4_I(dir)->i_dir_start_lookup;
916 if (start >= nblocks)
917 start = 0;
918 block = start;
919 restart:
920 do {
922 * We deal with the read-ahead logic here.
924 if (ra_ptr >= ra_max) {
925 /* Refill the readahead buffer */
926 ra_ptr = 0;
927 b = block;
928 for (ra_max = 0; ra_max < NAMEI_RA_SIZE; ra_max++) {
930 * Terminate if we reach the end of the
931 * directory and must wrap, or if our
932 * search has finished at this block.
934 if (b >= nblocks || (num && block == start)) {
935 bh_use[ra_max] = NULL;
936 break;
938 num++;
939 bh = ext4_getblk(NULL, dir, b++, 0, &err);
940 bh_use[ra_max] = bh;
941 if (bh)
942 ll_rw_block(READ_META, 1, &bh);
945 if ((bh = bh_use[ra_ptr++]) == NULL)
946 goto next;
947 wait_on_buffer(bh);
948 if (!buffer_uptodate(bh)) {
949 /* read error, skip block & hope for the best */
950 ext4_error(sb, __func__, "reading directory #%lu "
951 "offset %lu", dir->i_ino,
952 (unsigned long)block);
953 brelse(bh);
954 goto next;
956 i = search_dirblock(bh, dir, d_name,
957 block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
958 if (i == 1) {
959 EXT4_I(dir)->i_dir_start_lookup = block;
960 ret = bh;
961 goto cleanup_and_exit;
962 } else {
963 brelse(bh);
964 if (i < 0)
965 goto cleanup_and_exit;
967 next:
968 if (++block >= nblocks)
969 block = 0;
970 } while (block != start);
973 * If the directory has grown while we were searching, then
974 * search the last part of the directory before giving up.
976 block = nblocks;
977 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
978 if (block < nblocks) {
979 start = 0;
980 goto restart;
983 cleanup_and_exit:
984 /* Clean up the read-ahead blocks */
985 for (; ra_ptr < ra_max; ra_ptr++)
986 brelse(bh_use[ra_ptr]);
987 return ret;
990 static struct buffer_head * ext4_dx_find_entry(struct inode *dir, const struct qstr *d_name,
991 struct ext4_dir_entry_2 **res_dir, int *err)
993 struct super_block * sb;
994 struct dx_hash_info hinfo;
995 u32 hash;
996 struct dx_frame frames[2], *frame;
997 struct ext4_dir_entry_2 *de, *top;
998 struct buffer_head *bh;
999 ext4_lblk_t block;
1000 int retval;
1001 int namelen = d_name->len;
1002 const u8 *name = d_name->name;
1004 sb = dir->i_sb;
1005 /* NFS may look up ".." - look at dx_root directory block */
1006 if (namelen > 2 || name[0] != '.'||(name[1] != '.' && name[1] != '\0')){
1007 if (!(frame = dx_probe(d_name, dir, &hinfo, frames, err)))
1008 return NULL;
1009 } else {
1010 frame = frames;
1011 frame->bh = NULL; /* for dx_release() */
1012 frame->at = (struct dx_entry *)frames; /* hack for zero entry*/
1013 dx_set_block(frame->at, 0); /* dx_root block is 0 */
1015 hash = hinfo.hash;
1016 do {
1017 block = dx_get_block(frame->at);
1018 if (!(bh = ext4_bread (NULL,dir, block, 0, err)))
1019 goto errout;
1020 de = (struct ext4_dir_entry_2 *) bh->b_data;
1021 top = (struct ext4_dir_entry_2 *) ((char *) de + sb->s_blocksize -
1022 EXT4_DIR_REC_LEN(0));
1023 for (; de < top; de = ext4_next_entry(de, sb->s_blocksize)) {
1024 int off = (block << EXT4_BLOCK_SIZE_BITS(sb))
1025 + ((char *) de - bh->b_data);
1027 if (!ext4_check_dir_entry(__func__, dir, de, bh, off)) {
1028 brelse(bh);
1029 *err = ERR_BAD_DX_DIR;
1030 goto errout;
1033 if (ext4_match(namelen, name, de)) {
1034 *res_dir = de;
1035 dx_release(frames);
1036 return bh;
1039 brelse(bh);
1040 /* Check to see if we should continue to search */
1041 retval = ext4_htree_next_block(dir, hash, frame,
1042 frames, NULL);
1043 if (retval < 0) {
1044 ext4_warning(sb, __func__,
1045 "error reading index page in directory #%lu",
1046 dir->i_ino);
1047 *err = retval;
1048 goto errout;
1050 } while (retval == 1);
1052 *err = -ENOENT;
1053 errout:
1054 dxtrace(printk(KERN_DEBUG "%s not found\n", name));
1055 dx_release (frames);
1056 return NULL;
1059 static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
1061 struct inode *inode;
1062 struct ext4_dir_entry_2 *de;
1063 struct buffer_head *bh;
1065 if (dentry->d_name.len > EXT4_NAME_LEN)
1066 return ERR_PTR(-ENAMETOOLONG);
1068 bh = ext4_find_entry(dir, &dentry->d_name, &de);
1069 inode = NULL;
1070 if (bh) {
1071 __u32 ino = le32_to_cpu(de->inode);
1072 brelse(bh);
1073 if (!ext4_valid_inum(dir->i_sb, ino)) {
1074 ext4_error(dir->i_sb, "ext4_lookup",
1075 "bad inode number: %u", ino);
1076 return ERR_PTR(-EIO);
1078 inode = ext4_iget(dir->i_sb, ino);
1079 if (unlikely(IS_ERR(inode))) {
1080 if (PTR_ERR(inode) == -ESTALE) {
1081 ext4_error(dir->i_sb, __func__,
1082 "deleted inode referenced: %u",
1083 ino);
1084 return ERR_PTR(-EIO);
1085 } else {
1086 return ERR_CAST(inode);
1090 return d_splice_alias(inode, dentry);
1094 struct dentry *ext4_get_parent(struct dentry *child)
1096 __u32 ino;
1097 struct inode *inode;
1098 static const struct qstr dotdot = {
1099 .name = "..",
1100 .len = 2,
1102 struct ext4_dir_entry_2 * de;
1103 struct buffer_head *bh;
1105 bh = ext4_find_entry(child->d_inode, &dotdot, &de);
1106 inode = NULL;
1107 if (!bh)
1108 return ERR_PTR(-ENOENT);
1109 ino = le32_to_cpu(de->inode);
1110 brelse(bh);
1112 if (!ext4_valid_inum(child->d_inode->i_sb, ino)) {
1113 ext4_error(child->d_inode->i_sb, "ext4_get_parent",
1114 "bad inode number: %u", ino);
1115 return ERR_PTR(-EIO);
1118 return d_obtain_alias(ext4_iget(child->d_inode->i_sb, ino));
1121 #define S_SHIFT 12
1122 static unsigned char ext4_type_by_mode[S_IFMT >> S_SHIFT] = {
1123 [S_IFREG >> S_SHIFT] = EXT4_FT_REG_FILE,
1124 [S_IFDIR >> S_SHIFT] = EXT4_FT_DIR,
1125 [S_IFCHR >> S_SHIFT] = EXT4_FT_CHRDEV,
1126 [S_IFBLK >> S_SHIFT] = EXT4_FT_BLKDEV,
1127 [S_IFIFO >> S_SHIFT] = EXT4_FT_FIFO,
1128 [S_IFSOCK >> S_SHIFT] = EXT4_FT_SOCK,
1129 [S_IFLNK >> S_SHIFT] = EXT4_FT_SYMLINK,
1132 static inline void ext4_set_de_type(struct super_block *sb,
1133 struct ext4_dir_entry_2 *de,
1134 umode_t mode) {
1135 if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE))
1136 de->file_type = ext4_type_by_mode[(mode & S_IFMT)>>S_SHIFT];
1140 * Move count entries from end of map between two memory locations.
1141 * Returns pointer to last entry moved.
1143 static struct ext4_dir_entry_2 *
1144 dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count,
1145 unsigned blocksize)
1147 unsigned rec_len = 0;
1149 while (count--) {
1150 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
1151 (from + (map->offs<<2));
1152 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1153 memcpy (to, de, rec_len);
1154 ((struct ext4_dir_entry_2 *) to)->rec_len =
1155 ext4_rec_len_to_disk(rec_len, blocksize);
1156 de->inode = 0;
1157 map++;
1158 to += rec_len;
1160 return (struct ext4_dir_entry_2 *) (to - rec_len);
1164 * Compact each dir entry in the range to the minimal rec_len.
1165 * Returns pointer to last entry in range.
1167 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize)
1169 struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
1170 unsigned rec_len = 0;
1172 prev = to = de;
1173 while ((char*)de < base + blocksize) {
1174 next = ext4_next_entry(de, blocksize);
1175 if (de->inode && de->name_len) {
1176 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1177 if (de > to)
1178 memmove(to, de, rec_len);
1179 to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
1180 prev = to;
1181 to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
1183 de = next;
1185 return prev;
1189 * Split a full leaf block to make room for a new dir entry.
1190 * Allocate a new block, and move entries so that they are approx. equally full.
1191 * Returns pointer to de in block into which the new entry will be inserted.
1193 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
1194 struct buffer_head **bh,struct dx_frame *frame,
1195 struct dx_hash_info *hinfo, int *error)
1197 unsigned blocksize = dir->i_sb->s_blocksize;
1198 unsigned count, continued;
1199 struct buffer_head *bh2;
1200 ext4_lblk_t newblock;
1201 u32 hash2;
1202 struct dx_map_entry *map;
1203 char *data1 = (*bh)->b_data, *data2;
1204 unsigned split, move, size;
1205 struct ext4_dir_entry_2 *de = NULL, *de2;
1206 int err = 0, i;
1208 bh2 = ext4_append (handle, dir, &newblock, &err);
1209 if (!(bh2)) {
1210 brelse(*bh);
1211 *bh = NULL;
1212 goto errout;
1215 BUFFER_TRACE(*bh, "get_write_access");
1216 err = ext4_journal_get_write_access(handle, *bh);
1217 if (err)
1218 goto journal_error;
1220 BUFFER_TRACE(frame->bh, "get_write_access");
1221 err = ext4_journal_get_write_access(handle, frame->bh);
1222 if (err)
1223 goto journal_error;
1225 data2 = bh2->b_data;
1227 /* create map in the end of data2 block */
1228 map = (struct dx_map_entry *) (data2 + blocksize);
1229 count = dx_make_map((struct ext4_dir_entry_2 *) data1,
1230 blocksize, hinfo, map);
1231 map -= count;
1232 dx_sort_map(map, count);
1233 /* Split the existing block in the middle, size-wise */
1234 size = 0;
1235 move = 0;
1236 for (i = count-1; i >= 0; i--) {
1237 /* is more than half of this entry in 2nd half of the block? */
1238 if (size + map[i].size/2 > blocksize/2)
1239 break;
1240 size += map[i].size;
1241 move++;
1243 /* map index at which we will split */
1244 split = count - move;
1245 hash2 = map[split].hash;
1246 continued = hash2 == map[split - 1].hash;
1247 dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
1248 (unsigned long)dx_get_block(frame->at),
1249 hash2, split, count-split));
1251 /* Fancy dance to stay within two buffers */
1252 de2 = dx_move_dirents(data1, data2, map + split, count - split, blocksize);
1253 de = dx_pack_dirents(data1, blocksize);
1254 de->rec_len = ext4_rec_len_to_disk(data1 + blocksize - (char *) de,
1255 blocksize);
1256 de2->rec_len = ext4_rec_len_to_disk(data2 + blocksize - (char *) de2,
1257 blocksize);
1258 dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data1, blocksize, 1));
1259 dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data2, blocksize, 1));
1261 /* Which block gets the new entry? */
1262 if (hinfo->hash >= hash2)
1264 swap(*bh, bh2);
1265 de = de2;
1267 dx_insert_block(frame, hash2 + continued, newblock);
1268 err = ext4_handle_dirty_metadata(handle, dir, bh2);
1269 if (err)
1270 goto journal_error;
1271 err = ext4_handle_dirty_metadata(handle, dir, frame->bh);
1272 if (err)
1273 goto journal_error;
1274 brelse(bh2);
1275 dxtrace(dx_show_index("frame", frame->entries));
1276 return de;
1278 journal_error:
1279 brelse(*bh);
1280 brelse(bh2);
1281 *bh = NULL;
1282 ext4_std_error(dir->i_sb, err);
1283 errout:
1284 *error = err;
1285 return NULL;
1289 * Add a new entry into a directory (leaf) block. If de is non-NULL,
1290 * it points to a directory entry which is guaranteed to be large
1291 * enough for new directory entry. If de is NULL, then
1292 * add_dirent_to_buf will attempt search the directory block for
1293 * space. It will return -ENOSPC if no space is available, and -EIO
1294 * and -EEXIST if directory entry already exists.
1296 static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
1297 struct inode *inode, struct ext4_dir_entry_2 *de,
1298 struct buffer_head *bh)
1300 struct inode *dir = dentry->d_parent->d_inode;
1301 const char *name = dentry->d_name.name;
1302 int namelen = dentry->d_name.len;
1303 unsigned int offset = 0;
1304 unsigned int blocksize = dir->i_sb->s_blocksize;
1305 unsigned short reclen;
1306 int nlen, rlen, err;
1307 char *top;
1309 reclen = EXT4_DIR_REC_LEN(namelen);
1310 if (!de) {
1311 de = (struct ext4_dir_entry_2 *)bh->b_data;
1312 top = bh->b_data + blocksize - reclen;
1313 while ((char *) de <= top) {
1314 if (!ext4_check_dir_entry("ext4_add_entry", dir, de,
1315 bh, offset))
1316 return -EIO;
1317 if (ext4_match(namelen, name, de))
1318 return -EEXIST;
1319 nlen = EXT4_DIR_REC_LEN(de->name_len);
1320 rlen = ext4_rec_len_from_disk(de->rec_len, blocksize);
1321 if ((de->inode? rlen - nlen: rlen) >= reclen)
1322 break;
1323 de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
1324 offset += rlen;
1326 if ((char *) de > top)
1327 return -ENOSPC;
1329 BUFFER_TRACE(bh, "get_write_access");
1330 err = ext4_journal_get_write_access(handle, bh);
1331 if (err) {
1332 ext4_std_error(dir->i_sb, err);
1333 return err;
1336 /* By now the buffer is marked for journaling */
1337 nlen = EXT4_DIR_REC_LEN(de->name_len);
1338 rlen = ext4_rec_len_from_disk(de->rec_len, blocksize);
1339 if (de->inode) {
1340 struct ext4_dir_entry_2 *de1 = (struct ext4_dir_entry_2 *)((char *)de + nlen);
1341 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, blocksize);
1342 de->rec_len = ext4_rec_len_to_disk(nlen, blocksize);
1343 de = de1;
1345 de->file_type = EXT4_FT_UNKNOWN;
1346 if (inode) {
1347 de->inode = cpu_to_le32(inode->i_ino);
1348 ext4_set_de_type(dir->i_sb, de, inode->i_mode);
1349 } else
1350 de->inode = 0;
1351 de->name_len = namelen;
1352 memcpy(de->name, name, namelen);
1354 * XXX shouldn't update any times until successful
1355 * completion of syscall, but too many callers depend
1356 * on this.
1358 * XXX similarly, too many callers depend on
1359 * ext4_new_inode() setting the times, but error
1360 * recovery deletes the inode, so the worst that can
1361 * happen is that the times are slightly out of date
1362 * and/or different from the directory change time.
1364 dir->i_mtime = dir->i_ctime = ext4_current_time(dir);
1365 ext4_update_dx_flag(dir);
1366 dir->i_version++;
1367 ext4_mark_inode_dirty(handle, dir);
1368 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1369 err = ext4_handle_dirty_metadata(handle, dir, bh);
1370 if (err)
1371 ext4_std_error(dir->i_sb, err);
1372 return 0;
1376 * This converts a one block unindexed directory to a 3 block indexed
1377 * directory, and adds the dentry to the indexed directory.
1379 static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
1380 struct inode *inode, struct buffer_head *bh)
1382 struct inode *dir = dentry->d_parent->d_inode;
1383 const char *name = dentry->d_name.name;
1384 int namelen = dentry->d_name.len;
1385 struct buffer_head *bh2;
1386 struct dx_root *root;
1387 struct dx_frame frames[2], *frame;
1388 struct dx_entry *entries;
1389 struct ext4_dir_entry_2 *de, *de2;
1390 char *data1, *top;
1391 unsigned len;
1392 int retval;
1393 unsigned blocksize;
1394 struct dx_hash_info hinfo;
1395 ext4_lblk_t block;
1396 struct fake_dirent *fde;
1398 blocksize = dir->i_sb->s_blocksize;
1399 dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
1400 retval = ext4_journal_get_write_access(handle, bh);
1401 if (retval) {
1402 ext4_std_error(dir->i_sb, retval);
1403 brelse(bh);
1404 return retval;
1406 root = (struct dx_root *) bh->b_data;
1408 /* The 0th block becomes the root, move the dirents out */
1409 fde = &root->dotdot;
1410 de = (struct ext4_dir_entry_2 *)((char *)fde +
1411 ext4_rec_len_from_disk(fde->rec_len, blocksize));
1412 if ((char *) de >= (((char *) root) + blocksize)) {
1413 ext4_error(dir->i_sb, __func__,
1414 "invalid rec_len for '..' in inode %lu",
1415 dir->i_ino);
1416 brelse(bh);
1417 return -EIO;
1419 len = ((char *) root) + blocksize - (char *) de;
1421 /* Allocate new block for the 0th block's dirents */
1422 bh2 = ext4_append(handle, dir, &block, &retval);
1423 if (!(bh2)) {
1424 brelse(bh);
1425 return retval;
1427 ext4_set_inode_flag(dir, EXT4_INODE_INDEX);
1428 data1 = bh2->b_data;
1430 memcpy (data1, de, len);
1431 de = (struct ext4_dir_entry_2 *) data1;
1432 top = data1 + len;
1433 while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
1434 de = de2;
1435 de->rec_len = ext4_rec_len_to_disk(data1 + blocksize - (char *) de,
1436 blocksize);
1437 /* Initialize the root; the dot dirents already exist */
1438 de = (struct ext4_dir_entry_2 *) (&root->dotdot);
1439 de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
1440 blocksize);
1441 memset (&root->info, 0, sizeof(root->info));
1442 root->info.info_length = sizeof(root->info);
1443 root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
1444 entries = root->entries;
1445 dx_set_block(entries, 1);
1446 dx_set_count(entries, 1);
1447 dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
1449 /* Initialize as for dx_probe */
1450 hinfo.hash_version = root->info.hash_version;
1451 if (hinfo.hash_version <= DX_HASH_TEA)
1452 hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
1453 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
1454 ext4fs_dirhash(name, namelen, &hinfo);
1455 frame = frames;
1456 frame->entries = entries;
1457 frame->at = entries;
1458 frame->bh = bh;
1459 bh = bh2;
1460 de = do_split(handle,dir, &bh, frame, &hinfo, &retval);
1461 dx_release (frames);
1462 if (!(de))
1463 return retval;
1465 retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
1466 brelse(bh);
1467 return retval;
1471 * ext4_add_entry()
1473 * adds a file entry to the specified directory, using the same
1474 * semantics as ext4_find_entry(). It returns NULL if it failed.
1476 * NOTE!! The inode part of 'de' is left at 0 - which means you
1477 * may not sleep between calling this and putting something into
1478 * the entry, as someone else might have used it while you slept.
1480 static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
1481 struct inode *inode)
1483 struct inode *dir = dentry->d_parent->d_inode;
1484 struct buffer_head *bh;
1485 struct ext4_dir_entry_2 *de;
1486 struct super_block *sb;
1487 int retval;
1488 int dx_fallback=0;
1489 unsigned blocksize;
1490 ext4_lblk_t block, blocks;
1492 sb = dir->i_sb;
1493 blocksize = sb->s_blocksize;
1494 if (!dentry->d_name.len)
1495 return -EINVAL;
1496 if (is_dx(dir)) {
1497 retval = ext4_dx_add_entry(handle, dentry, inode);
1498 if (!retval || (retval != ERR_BAD_DX_DIR))
1499 return retval;
1500 ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
1501 dx_fallback++;
1502 ext4_mark_inode_dirty(handle, dir);
1504 blocks = dir->i_size >> sb->s_blocksize_bits;
1505 for (block = 0; block < blocks; block++) {
1506 bh = ext4_bread(handle, dir, block, 0, &retval);
1507 if(!bh)
1508 return retval;
1509 retval = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
1510 if (retval != -ENOSPC) {
1511 brelse(bh);
1512 return retval;
1515 if (blocks == 1 && !dx_fallback &&
1516 EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX))
1517 return make_indexed_dir(handle, dentry, inode, bh);
1518 brelse(bh);
1520 bh = ext4_append(handle, dir, &block, &retval);
1521 if (!bh)
1522 return retval;
1523 de = (struct ext4_dir_entry_2 *) bh->b_data;
1524 de->inode = 0;
1525 de->rec_len = ext4_rec_len_to_disk(blocksize, blocksize);
1526 retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
1527 brelse(bh);
1528 if (retval == 0)
1529 ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY);
1530 return retval;
1534 * Returns 0 for success, or a negative error value
1536 static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
1537 struct inode *inode)
1539 struct dx_frame frames[2], *frame;
1540 struct dx_entry *entries, *at;
1541 struct dx_hash_info hinfo;
1542 struct buffer_head *bh;
1543 struct inode *dir = dentry->d_parent->d_inode;
1544 struct super_block *sb = dir->i_sb;
1545 struct ext4_dir_entry_2 *de;
1546 int err;
1548 frame = dx_probe(&dentry->d_name, dir, &hinfo, frames, &err);
1549 if (!frame)
1550 return err;
1551 entries = frame->entries;
1552 at = frame->at;
1554 if (!(bh = ext4_bread(handle,dir, dx_get_block(frame->at), 0, &err)))
1555 goto cleanup;
1557 BUFFER_TRACE(bh, "get_write_access");
1558 err = ext4_journal_get_write_access(handle, bh);
1559 if (err)
1560 goto journal_error;
1562 err = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
1563 if (err != -ENOSPC)
1564 goto cleanup;
1566 /* Block full, should compress but for now just split */
1567 dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
1568 dx_get_count(entries), dx_get_limit(entries)));
1569 /* Need to split index? */
1570 if (dx_get_count(entries) == dx_get_limit(entries)) {
1571 ext4_lblk_t newblock;
1572 unsigned icount = dx_get_count(entries);
1573 int levels = frame - frames;
1574 struct dx_entry *entries2;
1575 struct dx_node *node2;
1576 struct buffer_head *bh2;
1578 if (levels && (dx_get_count(frames->entries) ==
1579 dx_get_limit(frames->entries))) {
1580 ext4_warning(sb, __func__,
1581 "Directory index full!");
1582 err = -ENOSPC;
1583 goto cleanup;
1585 bh2 = ext4_append (handle, dir, &newblock, &err);
1586 if (!(bh2))
1587 goto cleanup;
1588 node2 = (struct dx_node *)(bh2->b_data);
1589 entries2 = node2->entries;
1590 memset(&node2->fake, 0, sizeof(struct fake_dirent));
1591 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
1592 sb->s_blocksize);
1593 BUFFER_TRACE(frame->bh, "get_write_access");
1594 err = ext4_journal_get_write_access(handle, frame->bh);
1595 if (err)
1596 goto journal_error;
1597 if (levels) {
1598 unsigned icount1 = icount/2, icount2 = icount - icount1;
1599 unsigned hash2 = dx_get_hash(entries + icount1);
1600 dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
1601 icount1, icount2));
1603 BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
1604 err = ext4_journal_get_write_access(handle,
1605 frames[0].bh);
1606 if (err)
1607 goto journal_error;
1609 memcpy((char *) entries2, (char *) (entries + icount1),
1610 icount2 * sizeof(struct dx_entry));
1611 dx_set_count(entries, icount1);
1612 dx_set_count(entries2, icount2);
1613 dx_set_limit(entries2, dx_node_limit(dir));
1615 /* Which index block gets the new entry? */
1616 if (at - entries >= icount1) {
1617 frame->at = at = at - entries - icount1 + entries2;
1618 frame->entries = entries = entries2;
1619 swap(frame->bh, bh2);
1621 dx_insert_block(frames + 0, hash2, newblock);
1622 dxtrace(dx_show_index("node", frames[1].entries));
1623 dxtrace(dx_show_index("node",
1624 ((struct dx_node *) bh2->b_data)->entries));
1625 err = ext4_handle_dirty_metadata(handle, inode, bh2);
1626 if (err)
1627 goto journal_error;
1628 brelse (bh2);
1629 } else {
1630 dxtrace(printk(KERN_DEBUG
1631 "Creating second level index...\n"));
1632 memcpy((char *) entries2, (char *) entries,
1633 icount * sizeof(struct dx_entry));
1634 dx_set_limit(entries2, dx_node_limit(dir));
1636 /* Set up root */
1637 dx_set_count(entries, 1);
1638 dx_set_block(entries + 0, newblock);
1639 ((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels = 1;
1641 /* Add new access path frame */
1642 frame = frames + 1;
1643 frame->at = at = at - entries + entries2;
1644 frame->entries = entries = entries2;
1645 frame->bh = bh2;
1646 err = ext4_journal_get_write_access(handle,
1647 frame->bh);
1648 if (err)
1649 goto journal_error;
1651 ext4_handle_dirty_metadata(handle, inode, frames[0].bh);
1653 de = do_split(handle, dir, &bh, frame, &hinfo, &err);
1654 if (!de)
1655 goto cleanup;
1656 err = add_dirent_to_buf(handle, dentry, inode, de, bh);
1657 goto cleanup;
1659 journal_error:
1660 ext4_std_error(dir->i_sb, err);
1661 cleanup:
1662 if (bh)
1663 brelse(bh);
1664 dx_release(frames);
1665 return err;
1669 * ext4_delete_entry deletes a directory entry by merging it with the
1670 * previous entry
1672 static int ext4_delete_entry(handle_t *handle,
1673 struct inode *dir,
1674 struct ext4_dir_entry_2 *de_del,
1675 struct buffer_head *bh)
1677 struct ext4_dir_entry_2 *de, *pde;
1678 unsigned int blocksize = dir->i_sb->s_blocksize;
1679 int i;
1681 i = 0;
1682 pde = NULL;
1683 de = (struct ext4_dir_entry_2 *) bh->b_data;
1684 while (i < bh->b_size) {
1685 if (!ext4_check_dir_entry("ext4_delete_entry", dir, de, bh, i))
1686 return -EIO;
1687 if (de == de_del) {
1688 BUFFER_TRACE(bh, "get_write_access");
1689 ext4_journal_get_write_access(handle, bh);
1690 if (pde)
1691 pde->rec_len = ext4_rec_len_to_disk(
1692 ext4_rec_len_from_disk(pde->rec_len,
1693 blocksize) +
1694 ext4_rec_len_from_disk(de->rec_len,
1695 blocksize),
1696 blocksize);
1697 else
1698 de->inode = 0;
1699 dir->i_version++;
1700 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1701 ext4_handle_dirty_metadata(handle, dir, bh);
1702 return 0;
1704 i += ext4_rec_len_from_disk(de->rec_len, blocksize);
1705 pde = de;
1706 de = ext4_next_entry(de, blocksize);
1708 return -ENOENT;
1712 * DIR_NLINK feature is set if 1) nlinks > EXT4_LINK_MAX or 2) nlinks == 2,
1713 * since this indicates that nlinks count was previously 1.
1715 static void ext4_inc_count(handle_t *handle, struct inode *inode)
1717 inc_nlink(inode);
1718 if (is_dx(inode) && inode->i_nlink > 1) {
1719 /* limit is 16-bit i_links_count */
1720 if (inode->i_nlink >= EXT4_LINK_MAX || inode->i_nlink == 2) {
1721 inode->i_nlink = 1;
1722 EXT4_SET_RO_COMPAT_FEATURE(inode->i_sb,
1723 EXT4_FEATURE_RO_COMPAT_DIR_NLINK);
1729 * If a directory had nlink == 1, then we should let it be 1. This indicates
1730 * directory has >EXT4_LINK_MAX subdirs.
1732 static void ext4_dec_count(handle_t *handle, struct inode *inode)
1734 drop_nlink(inode);
1735 if (S_ISDIR(inode->i_mode) && inode->i_nlink == 0)
1736 inc_nlink(inode);
1740 static int ext4_add_nondir(handle_t *handle,
1741 struct dentry *dentry, struct inode *inode)
1743 int err = ext4_add_entry(handle, dentry, inode);
1744 if (!err) {
1745 ext4_mark_inode_dirty(handle, inode);
1746 d_instantiate(dentry, inode);
1747 unlock_new_inode(inode);
1748 return 0;
1750 drop_nlink(inode);
1751 unlock_new_inode(inode);
1752 iput(inode);
1753 return err;
1757 * By the time this is called, we already have created
1758 * the directory cache entry for the new file, but it
1759 * is so far negative - it has no inode.
1761 * If the create succeeds, we fill in the inode information
1762 * with d_instantiate().
1764 static int ext4_create(struct inode *dir, struct dentry *dentry, int mode,
1765 struct nameidata *nd)
1767 handle_t *handle;
1768 struct inode *inode;
1769 int err, retries = 0;
1771 retry:
1772 handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
1773 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
1774 EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
1775 if (IS_ERR(handle))
1776 return PTR_ERR(handle);
1778 if (IS_DIRSYNC(dir))
1779 ext4_handle_sync(handle);
1781 inode = ext4_new_inode(handle, dir, mode, &dentry->d_name, 0);
1782 err = PTR_ERR(inode);
1783 if (!IS_ERR(inode)) {
1784 inode->i_op = &ext4_file_inode_operations;
1785 inode->i_fop = &ext4_file_operations;
1786 ext4_set_aops(inode);
1787 err = ext4_add_nondir(handle, dentry, inode);
1789 ext4_journal_stop(handle);
1790 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
1791 goto retry;
1792 return err;
1795 static int ext4_mknod(struct inode *dir, struct dentry *dentry,
1796 int mode, dev_t rdev)
1798 handle_t *handle;
1799 struct inode *inode;
1800 int err, retries = 0;
1802 if (!new_valid_dev(rdev))
1803 return -EINVAL;
1805 retry:
1806 handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
1807 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
1808 EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
1809 if (IS_ERR(handle))
1810 return PTR_ERR(handle);
1812 if (IS_DIRSYNC(dir))
1813 ext4_handle_sync(handle);
1815 inode = ext4_new_inode(handle, dir, mode, &dentry->d_name, 0);
1816 err = PTR_ERR(inode);
1817 if (!IS_ERR(inode)) {
1818 init_special_inode(inode, inode->i_mode, rdev);
1819 #ifdef CONFIG_EXT4_FS_XATTR
1820 inode->i_op = &ext4_special_inode_operations;
1821 #endif
1822 err = ext4_add_nondir(handle, dentry, inode);
1824 ext4_journal_stop(handle);
1825 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
1826 goto retry;
1827 return err;
1830 static int ext4_mkdir(struct inode *dir, struct dentry *dentry, int mode)
1832 handle_t *handle;
1833 struct inode *inode;
1834 struct buffer_head *dir_block;
1835 struct ext4_dir_entry_2 *de;
1836 unsigned int blocksize = dir->i_sb->s_blocksize;
1837 int err, retries = 0;
1839 if (EXT4_DIR_LINK_MAX(dir))
1840 return -EMLINK;
1842 retry:
1843 handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
1844 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
1845 EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
1846 if (IS_ERR(handle))
1847 return PTR_ERR(handle);
1849 if (IS_DIRSYNC(dir))
1850 ext4_handle_sync(handle);
1852 inode = ext4_new_inode(handle, dir, S_IFDIR | mode,
1853 &dentry->d_name, 0);
1854 err = PTR_ERR(inode);
1855 if (IS_ERR(inode))
1856 goto out_stop;
1858 inode->i_op = &ext4_dir_inode_operations;
1859 inode->i_fop = &ext4_dir_operations;
1860 inode->i_size = EXT4_I(inode)->i_disksize = inode->i_sb->s_blocksize;
1861 dir_block = ext4_bread(handle, inode, 0, 1, &err);
1862 if (!dir_block)
1863 goto out_clear_inode;
1864 BUFFER_TRACE(dir_block, "get_write_access");
1865 ext4_journal_get_write_access(handle, dir_block);
1866 de = (struct ext4_dir_entry_2 *) dir_block->b_data;
1867 de->inode = cpu_to_le32(inode->i_ino);
1868 de->name_len = 1;
1869 de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
1870 blocksize);
1871 strcpy(de->name, ".");
1872 ext4_set_de_type(dir->i_sb, de, S_IFDIR);
1873 de = ext4_next_entry(de, blocksize);
1874 de->inode = cpu_to_le32(dir->i_ino);
1875 de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(1),
1876 blocksize);
1877 de->name_len = 2;
1878 strcpy(de->name, "..");
1879 ext4_set_de_type(dir->i_sb, de, S_IFDIR);
1880 inode->i_nlink = 2;
1881 BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
1882 ext4_handle_dirty_metadata(handle, dir, dir_block);
1883 brelse(dir_block);
1884 ext4_mark_inode_dirty(handle, inode);
1885 err = ext4_add_entry(handle, dentry, inode);
1886 if (err) {
1887 out_clear_inode:
1888 clear_nlink(inode);
1889 unlock_new_inode(inode);
1890 ext4_mark_inode_dirty(handle, inode);
1891 iput(inode);
1892 goto out_stop;
1894 ext4_inc_count(handle, dir);
1895 ext4_update_dx_flag(dir);
1896 ext4_mark_inode_dirty(handle, dir);
1897 d_instantiate(dentry, inode);
1898 unlock_new_inode(inode);
1899 out_stop:
1900 ext4_journal_stop(handle);
1901 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
1902 goto retry;
1903 return err;
1907 * routine to check that the specified directory is empty (for rmdir)
1909 static int empty_dir(struct inode *inode)
1911 unsigned int offset;
1912 struct buffer_head *bh;
1913 struct ext4_dir_entry_2 *de, *de1;
1914 struct super_block *sb;
1915 int err = 0;
1917 sb = inode->i_sb;
1918 if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2) ||
1919 !(bh = ext4_bread(NULL, inode, 0, 0, &err))) {
1920 if (err)
1921 ext4_error(inode->i_sb, __func__,
1922 "error %d reading directory #%lu offset 0",
1923 err, inode->i_ino);
1924 else
1925 ext4_warning(inode->i_sb, __func__,
1926 "bad directory (dir #%lu) - no data block",
1927 inode->i_ino);
1928 return 1;
1930 de = (struct ext4_dir_entry_2 *) bh->b_data;
1931 de1 = ext4_next_entry(de, sb->s_blocksize);
1932 if (le32_to_cpu(de->inode) != inode->i_ino ||
1933 !le32_to_cpu(de1->inode) ||
1934 strcmp(".", de->name) ||
1935 strcmp("..", de1->name)) {
1936 ext4_warning(inode->i_sb, "empty_dir",
1937 "bad directory (dir #%lu) - no `.' or `..'",
1938 inode->i_ino);
1939 brelse(bh);
1940 return 1;
1942 offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) +
1943 ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize);
1944 de = ext4_next_entry(de1, sb->s_blocksize);
1945 while (offset < inode->i_size) {
1946 if (!bh ||
1947 (void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
1948 err = 0;
1949 brelse(bh);
1950 bh = ext4_bread(NULL, inode,
1951 offset >> EXT4_BLOCK_SIZE_BITS(sb), 0, &err);
1952 if (!bh) {
1953 if (err)
1954 ext4_error(sb, __func__,
1955 "error %d reading directory"
1956 " #%lu offset %u",
1957 err, inode->i_ino, offset);
1958 offset += sb->s_blocksize;
1959 continue;
1961 de = (struct ext4_dir_entry_2 *) bh->b_data;
1963 if (!ext4_check_dir_entry("empty_dir", inode, de, bh, offset)) {
1964 de = (struct ext4_dir_entry_2 *)(bh->b_data +
1965 sb->s_blocksize);
1966 offset = (offset | (sb->s_blocksize - 1)) + 1;
1967 continue;
1969 if (le32_to_cpu(de->inode)) {
1970 brelse(bh);
1971 return 0;
1973 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
1974 de = ext4_next_entry(de, sb->s_blocksize);
1976 brelse(bh);
1977 return 1;
1980 /* ext4_orphan_add() links an unlinked or truncated inode into a list of
1981 * such inodes, starting at the superblock, in case we crash before the
1982 * file is closed/deleted, or in case the inode truncate spans multiple
1983 * transactions and the last transaction is not recovered after a crash.
1985 * At filesystem recovery time, we walk this list deleting unlinked
1986 * inodes and truncating linked inodes in ext4_orphan_cleanup().
1988 int ext4_orphan_add(handle_t *handle, struct inode *inode)
1990 struct super_block *sb = inode->i_sb;
1991 struct ext4_iloc iloc;
1992 int err = 0, rc;
1994 if (!ext4_handle_valid(handle))
1995 return 0;
1997 mutex_lock(&EXT4_SB(sb)->s_orphan_lock);
1998 if (!list_empty(&EXT4_I(inode)->i_orphan))
1999 goto out_unlock;
2001 /* Orphan handling is only valid for files with data blocks
2002 * being truncated, or files being unlinked. */
2004 /* @@@ FIXME: Observation from aviro:
2005 * I think I can trigger J_ASSERT in ext4_orphan_add(). We block
2006 * here (on s_orphan_lock), so race with ext4_link() which might bump
2007 * ->i_nlink. For, say it, character device. Not a regular file,
2008 * not a directory, not a symlink and ->i_nlink > 0.
2010 * tytso, 4/25/2009: I'm not sure how that could happen;
2011 * shouldn't the fs core protect us from these sort of
2012 * unlink()/link() races?
2014 J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2015 S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
2017 BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access");
2018 err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
2019 if (err)
2020 goto out_unlock;
2022 err = ext4_reserve_inode_write(handle, inode, &iloc);
2023 if (err)
2024 goto out_unlock;
2026 * Due to previous errors inode may be already a part of on-disk
2027 * orphan list. If so skip on-disk list modification.
2029 if (NEXT_ORPHAN(inode) && NEXT_ORPHAN(inode) <=
2030 (le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count)))
2031 goto mem_insert;
2033 /* Insert this inode at the head of the on-disk orphan list... */
2034 NEXT_ORPHAN(inode) = le32_to_cpu(EXT4_SB(sb)->s_es->s_last_orphan);
2035 EXT4_SB(sb)->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
2036 err = ext4_handle_dirty_metadata(handle, NULL, EXT4_SB(sb)->s_sbh);
2037 rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
2038 if (!err)
2039 err = rc;
2041 /* Only add to the head of the in-memory list if all the
2042 * previous operations succeeded. If the orphan_add is going to
2043 * fail (possibly taking the journal offline), we can't risk
2044 * leaving the inode on the orphan list: stray orphan-list
2045 * entries can cause panics at unmount time.
2047 * This is safe: on error we're going to ignore the orphan list
2048 * anyway on the next recovery. */
2049 mem_insert:
2050 if (!err)
2051 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2053 jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
2054 jbd_debug(4, "orphan inode %lu will point to %d\n",
2055 inode->i_ino, NEXT_ORPHAN(inode));
2056 out_unlock:
2057 mutex_unlock(&EXT4_SB(sb)->s_orphan_lock);
2058 ext4_std_error(inode->i_sb, err);
2059 return err;
2063 * ext4_orphan_del() removes an unlinked or truncated inode from the list
2064 * of such inodes stored on disk, because it is finally being cleaned up.
2066 int ext4_orphan_del(handle_t *handle, struct inode *inode)
2068 struct list_head *prev;
2069 struct ext4_inode_info *ei = EXT4_I(inode);
2070 struct ext4_sb_info *sbi;
2071 __u32 ino_next;
2072 struct ext4_iloc iloc;
2073 int err = 0;
2075 /* ext4_handle_valid() assumes a valid handle_t pointer */
2076 if (handle && !ext4_handle_valid(handle))
2077 return 0;
2079 mutex_lock(&EXT4_SB(inode->i_sb)->s_orphan_lock);
2080 if (list_empty(&ei->i_orphan))
2081 goto out;
2083 ino_next = NEXT_ORPHAN(inode);
2084 prev = ei->i_orphan.prev;
2085 sbi = EXT4_SB(inode->i_sb);
2087 jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
2089 list_del_init(&ei->i_orphan);
2091 /* If we're on an error path, we may not have a valid
2092 * transaction handle with which to update the orphan list on
2093 * disk, but we still need to remove the inode from the linked
2094 * list in memory. */
2095 if (sbi->s_journal && !handle)
2096 goto out;
2098 err = ext4_reserve_inode_write(handle, inode, &iloc);
2099 if (err)
2100 goto out_err;
2102 if (prev == &sbi->s_orphan) {
2103 jbd_debug(4, "superblock will point to %u\n", ino_next);
2104 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2105 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2106 if (err)
2107 goto out_brelse;
2108 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
2109 err = ext4_handle_dirty_metadata(handle, NULL, sbi->s_sbh);
2110 } else {
2111 struct ext4_iloc iloc2;
2112 struct inode *i_prev =
2113 &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
2115 jbd_debug(4, "orphan inode %lu will point to %u\n",
2116 i_prev->i_ino, ino_next);
2117 err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
2118 if (err)
2119 goto out_brelse;
2120 NEXT_ORPHAN(i_prev) = ino_next;
2121 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
2123 if (err)
2124 goto out_brelse;
2125 NEXT_ORPHAN(inode) = 0;
2126 err = ext4_mark_iloc_dirty(handle, inode, &iloc);
2128 out_err:
2129 ext4_std_error(inode->i_sb, err);
2130 out:
2131 mutex_unlock(&EXT4_SB(inode->i_sb)->s_orphan_lock);
2132 return err;
2134 out_brelse:
2135 brelse(iloc.bh);
2136 goto out_err;
2139 static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
2141 int retval;
2142 struct inode *inode;
2143 struct buffer_head *bh;
2144 struct ext4_dir_entry_2 *de;
2145 handle_t *handle;
2147 /* Initialize quotas before so that eventual writes go in
2148 * separate transaction */
2149 vfs_dq_init(dentry->d_inode);
2150 handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb));
2151 if (IS_ERR(handle))
2152 return PTR_ERR(handle);
2154 retval = -ENOENT;
2155 bh = ext4_find_entry(dir, &dentry->d_name, &de);
2156 if (!bh)
2157 goto end_rmdir;
2159 if (IS_DIRSYNC(dir))
2160 ext4_handle_sync(handle);
2162 inode = dentry->d_inode;
2164 retval = -EIO;
2165 if (le32_to_cpu(de->inode) != inode->i_ino)
2166 goto end_rmdir;
2168 retval = -ENOTEMPTY;
2169 if (!empty_dir(inode))
2170 goto end_rmdir;
2172 retval = ext4_delete_entry(handle, dir, de, bh);
2173 if (retval)
2174 goto end_rmdir;
2175 if (!EXT4_DIR_LINK_EMPTY(inode))
2176 ext4_warning(inode->i_sb, "ext4_rmdir",
2177 "empty directory has too many links (%d)",
2178 inode->i_nlink);
2179 inode->i_version++;
2180 clear_nlink(inode);
2181 /* There's no need to set i_disksize: the fact that i_nlink is
2182 * zero will ensure that the right thing happens during any
2183 * recovery. */
2184 inode->i_size = 0;
2185 ext4_orphan_add(handle, inode);
2186 inode->i_ctime = dir->i_ctime = dir->i_mtime = ext4_current_time(inode);
2187 ext4_mark_inode_dirty(handle, inode);
2188 ext4_dec_count(handle, dir);
2189 ext4_update_dx_flag(dir);
2190 ext4_mark_inode_dirty(handle, dir);
2192 end_rmdir:
2193 ext4_journal_stop(handle);
2194 brelse(bh);
2195 return retval;
2198 static int ext4_unlink(struct inode *dir, struct dentry *dentry)
2200 int retval;
2201 struct inode *inode;
2202 struct buffer_head *bh;
2203 struct ext4_dir_entry_2 *de;
2204 handle_t *handle;
2206 /* Initialize quotas before so that eventual writes go
2207 * in separate transaction */
2208 vfs_dq_init(dentry->d_inode);
2209 handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb));
2210 if (IS_ERR(handle))
2211 return PTR_ERR(handle);
2213 if (IS_DIRSYNC(dir))
2214 ext4_handle_sync(handle);
2216 retval = -ENOENT;
2217 bh = ext4_find_entry(dir, &dentry->d_name, &de);
2218 if (!bh)
2219 goto end_unlink;
2221 inode = dentry->d_inode;
2223 retval = -EIO;
2224 if (le32_to_cpu(de->inode) != inode->i_ino)
2225 goto end_unlink;
2227 if (!inode->i_nlink) {
2228 ext4_warning(inode->i_sb, "ext4_unlink",
2229 "Deleting nonexistent file (%lu), %d",
2230 inode->i_ino, inode->i_nlink);
2231 inode->i_nlink = 1;
2233 retval = ext4_delete_entry(handle, dir, de, bh);
2234 if (retval)
2235 goto end_unlink;
2236 dir->i_ctime = dir->i_mtime = ext4_current_time(dir);
2237 ext4_update_dx_flag(dir);
2238 ext4_mark_inode_dirty(handle, dir);
2239 drop_nlink(inode);
2240 if (!inode->i_nlink)
2241 ext4_orphan_add(handle, inode);
2242 inode->i_ctime = ext4_current_time(inode);
2243 ext4_mark_inode_dirty(handle, inode);
2244 retval = 0;
2246 end_unlink:
2247 ext4_journal_stop(handle);
2248 brelse(bh);
2249 return retval;
2252 static int ext4_symlink(struct inode *dir,
2253 struct dentry *dentry, const char *symname)
2255 handle_t *handle;
2256 struct inode *inode;
2257 int l, err, retries = 0;
2259 l = strlen(symname)+1;
2260 if (l > dir->i_sb->s_blocksize)
2261 return -ENAMETOOLONG;
2263 retry:
2264 handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2265 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 5 +
2266 EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
2267 if (IS_ERR(handle))
2268 return PTR_ERR(handle);
2270 if (IS_DIRSYNC(dir))
2271 ext4_handle_sync(handle);
2273 inode = ext4_new_inode(handle, dir, S_IFLNK|S_IRWXUGO,
2274 &dentry->d_name, 0);
2275 err = PTR_ERR(inode);
2276 if (IS_ERR(inode))
2277 goto out_stop;
2279 if (l > sizeof(EXT4_I(inode)->i_data)) {
2280 inode->i_op = &ext4_symlink_inode_operations;
2281 ext4_set_aops(inode);
2283 * page_symlink() calls into ext4_prepare/commit_write.
2284 * We have a transaction open. All is sweetness. It also sets
2285 * i_size in generic_commit_write().
2287 err = __page_symlink(inode, symname, l, 1);
2288 if (err) {
2289 clear_nlink(inode);
2290 unlock_new_inode(inode);
2291 ext4_mark_inode_dirty(handle, inode);
2292 iput(inode);
2293 goto out_stop;
2295 } else {
2296 /* clear the extent format for fast symlink */
2297 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
2298 inode->i_op = &ext4_fast_symlink_inode_operations;
2299 memcpy((char *)&EXT4_I(inode)->i_data, symname, l);
2300 inode->i_size = l-1;
2302 EXT4_I(inode)->i_disksize = inode->i_size;
2303 err = ext4_add_nondir(handle, dentry, inode);
2304 out_stop:
2305 ext4_journal_stop(handle);
2306 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2307 goto retry;
2308 return err;
2311 static int ext4_link(struct dentry *old_dentry,
2312 struct inode *dir, struct dentry *dentry)
2314 handle_t *handle;
2315 struct inode *inode = old_dentry->d_inode;
2316 int err, retries = 0;
2318 if (inode->i_nlink >= EXT4_LINK_MAX)
2319 return -EMLINK;
2322 * Return -ENOENT if we've raced with unlink and i_nlink is 0. Doing
2323 * otherwise has the potential to corrupt the orphan inode list.
2325 if (inode->i_nlink == 0)
2326 return -ENOENT;
2328 retry:
2329 handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2330 EXT4_INDEX_EXTRA_TRANS_BLOCKS);
2331 if (IS_ERR(handle))
2332 return PTR_ERR(handle);
2334 if (IS_DIRSYNC(dir))
2335 ext4_handle_sync(handle);
2337 inode->i_ctime = ext4_current_time(inode);
2338 ext4_inc_count(handle, inode);
2339 atomic_inc(&inode->i_count);
2341 err = ext4_add_entry(handle, dentry, inode);
2342 if (!err) {
2343 ext4_mark_inode_dirty(handle, inode);
2344 d_instantiate(dentry, inode);
2345 } else {
2346 drop_nlink(inode);
2347 iput(inode);
2349 ext4_journal_stop(handle);
2350 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2351 goto retry;
2352 return err;
2355 #define PARENT_INO(buffer, size) \
2356 (ext4_next_entry((struct ext4_dir_entry_2 *)(buffer), size)->inode)
2359 * Anybody can rename anything with this: the permission checks are left to the
2360 * higher-level routines.
2362 static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
2363 struct inode *new_dir, struct dentry *new_dentry)
2365 handle_t *handle;
2366 struct inode *old_inode, *new_inode;
2367 struct buffer_head *old_bh, *new_bh, *dir_bh;
2368 struct ext4_dir_entry_2 *old_de, *new_de;
2369 int retval, force_da_alloc = 0;
2371 old_bh = new_bh = dir_bh = NULL;
2373 /* Initialize quotas before so that eventual writes go
2374 * in separate transaction */
2375 if (new_dentry->d_inode)
2376 vfs_dq_init(new_dentry->d_inode);
2377 handle = ext4_journal_start(old_dir, 2 *
2378 EXT4_DATA_TRANS_BLOCKS(old_dir->i_sb) +
2379 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
2380 if (IS_ERR(handle))
2381 return PTR_ERR(handle);
2383 if (IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir))
2384 ext4_handle_sync(handle);
2386 old_bh = ext4_find_entry(old_dir, &old_dentry->d_name, &old_de);
2388 * Check for inode number is _not_ due to possible IO errors.
2389 * We might rmdir the source, keep it as pwd of some process
2390 * and merrily kill the link to whatever was created under the
2391 * same name. Goodbye sticky bit ;-<
2393 old_inode = old_dentry->d_inode;
2394 retval = -ENOENT;
2395 if (!old_bh || le32_to_cpu(old_de->inode) != old_inode->i_ino)
2396 goto end_rename;
2398 new_inode = new_dentry->d_inode;
2399 new_bh = ext4_find_entry(new_dir, &new_dentry->d_name, &new_de);
2400 if (new_bh) {
2401 if (!new_inode) {
2402 brelse(new_bh);
2403 new_bh = NULL;
2406 if (S_ISDIR(old_inode->i_mode)) {
2407 if (new_inode) {
2408 retval = -ENOTEMPTY;
2409 if (!empty_dir(new_inode))
2410 goto end_rename;
2412 retval = -EIO;
2413 dir_bh = ext4_bread(handle, old_inode, 0, 0, &retval);
2414 if (!dir_bh)
2415 goto end_rename;
2416 if (le32_to_cpu(PARENT_INO(dir_bh->b_data,
2417 old_dir->i_sb->s_blocksize)) != old_dir->i_ino)
2418 goto end_rename;
2419 retval = -EMLINK;
2420 if (!new_inode && new_dir != old_dir &&
2421 EXT4_DIR_LINK_MAX(new_dir))
2422 goto end_rename;
2424 if (!new_bh) {
2425 retval = ext4_add_entry(handle, new_dentry, old_inode);
2426 if (retval)
2427 goto end_rename;
2428 } else {
2429 BUFFER_TRACE(new_bh, "get write access");
2430 ext4_journal_get_write_access(handle, new_bh);
2431 new_de->inode = cpu_to_le32(old_inode->i_ino);
2432 if (EXT4_HAS_INCOMPAT_FEATURE(new_dir->i_sb,
2433 EXT4_FEATURE_INCOMPAT_FILETYPE))
2434 new_de->file_type = old_de->file_type;
2435 new_dir->i_version++;
2436 new_dir->i_ctime = new_dir->i_mtime =
2437 ext4_current_time(new_dir);
2438 ext4_mark_inode_dirty(handle, new_dir);
2439 BUFFER_TRACE(new_bh, "call ext4_handle_dirty_metadata");
2440 ext4_handle_dirty_metadata(handle, new_dir, new_bh);
2441 brelse(new_bh);
2442 new_bh = NULL;
2446 * Like most other Unix systems, set the ctime for inodes on a
2447 * rename.
2449 old_inode->i_ctime = ext4_current_time(old_inode);
2450 ext4_mark_inode_dirty(handle, old_inode);
2453 * ok, that's it
2455 if (le32_to_cpu(old_de->inode) != old_inode->i_ino ||
2456 old_de->name_len != old_dentry->d_name.len ||
2457 strncmp(old_de->name, old_dentry->d_name.name, old_de->name_len) ||
2458 (retval = ext4_delete_entry(handle, old_dir,
2459 old_de, old_bh)) == -ENOENT) {
2460 /* old_de could have moved from under us during htree split, so
2461 * make sure that we are deleting the right entry. We might
2462 * also be pointing to a stale entry in the unused part of
2463 * old_bh so just checking inum and the name isn't enough. */
2464 struct buffer_head *old_bh2;
2465 struct ext4_dir_entry_2 *old_de2;
2467 old_bh2 = ext4_find_entry(old_dir, &old_dentry->d_name, &old_de2);
2468 if (old_bh2) {
2469 retval = ext4_delete_entry(handle, old_dir,
2470 old_de2, old_bh2);
2471 brelse(old_bh2);
2474 if (retval) {
2475 ext4_warning(old_dir->i_sb, "ext4_rename",
2476 "Deleting old file (%lu), %d, error=%d",
2477 old_dir->i_ino, old_dir->i_nlink, retval);
2480 if (new_inode) {
2481 ext4_dec_count(handle, new_inode);
2482 new_inode->i_ctime = ext4_current_time(new_inode);
2484 old_dir->i_ctime = old_dir->i_mtime = ext4_current_time(old_dir);
2485 ext4_update_dx_flag(old_dir);
2486 if (dir_bh) {
2487 BUFFER_TRACE(dir_bh, "get_write_access");
2488 ext4_journal_get_write_access(handle, dir_bh);
2489 PARENT_INO(dir_bh->b_data, new_dir->i_sb->s_blocksize) =
2490 cpu_to_le32(new_dir->i_ino);
2491 BUFFER_TRACE(dir_bh, "call ext4_handle_dirty_metadata");
2492 ext4_handle_dirty_metadata(handle, old_dir, dir_bh);
2493 ext4_dec_count(handle, old_dir);
2494 if (new_inode) {
2495 /* checked empty_dir above, can't have another parent,
2496 * ext4_dec_count() won't work for many-linked dirs */
2497 new_inode->i_nlink = 0;
2498 } else {
2499 ext4_inc_count(handle, new_dir);
2500 ext4_update_dx_flag(new_dir);
2501 ext4_mark_inode_dirty(handle, new_dir);
2504 ext4_mark_inode_dirty(handle, old_dir);
2505 if (new_inode) {
2506 ext4_mark_inode_dirty(handle, new_inode);
2507 if (!new_inode->i_nlink)
2508 ext4_orphan_add(handle, new_inode);
2509 if (!test_opt(new_dir->i_sb, NO_AUTO_DA_ALLOC))
2510 force_da_alloc = 1;
2512 retval = 0;
2514 end_rename:
2515 brelse(dir_bh);
2516 brelse(old_bh);
2517 brelse(new_bh);
2518 ext4_journal_stop(handle);
2519 if (retval == 0 && force_da_alloc)
2520 ext4_alloc_da_blocks(old_inode);
2521 return retval;
2525 * directories can handle most operations...
2527 const struct inode_operations ext4_dir_inode_operations = {
2528 .create = ext4_create,
2529 .lookup = ext4_lookup,
2530 .link = ext4_link,
2531 .unlink = ext4_unlink,
2532 .symlink = ext4_symlink,
2533 .mkdir = ext4_mkdir,
2534 .rmdir = ext4_rmdir,
2535 .mknod = ext4_mknod,
2536 .rename = ext4_rename,
2537 .setattr = ext4_setattr,
2538 #ifdef CONFIG_EXT4_FS_XATTR
2539 .setxattr = generic_setxattr,
2540 .getxattr = generic_getxattr,
2541 .listxattr = ext4_listxattr,
2542 .removexattr = generic_removexattr,
2543 #endif
2544 .check_acl = ext4_check_acl,
2545 .fiemap = ext4_fiemap,
2548 const struct inode_operations ext4_special_inode_operations = {
2549 .setattr = ext4_setattr,
2550 #ifdef CONFIG_EXT4_FS_XATTR
2551 .setxattr = generic_setxattr,
2552 .getxattr = generic_getxattr,
2553 .listxattr = ext4_listxattr,
2554 .removexattr = generic_removexattr,
2555 #endif
2556 .check_acl = ext4_check_acl,