[ARM] add address randomization to mmap()
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / ext4 / namei.c
bloba43e6617b35119e6bb46815e4f73aa2a518a4e30
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, "Unrecognised inode hash code %d",
387 root->info.hash_version);
388 brelse(bh);
389 *err = ERR_BAD_DX_DIR;
390 goto fail;
392 hinfo->hash_version = root->info.hash_version;
393 if (hinfo->hash_version <= DX_HASH_TEA)
394 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
395 hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
396 if (d_name)
397 ext4fs_dirhash(d_name->name, d_name->len, hinfo);
398 hash = hinfo->hash;
400 if (root->info.unused_flags & 1) {
401 ext4_warning(dir->i_sb, "Unimplemented inode hash flags: %#06x",
402 root->info.unused_flags);
403 brelse(bh);
404 *err = ERR_BAD_DX_DIR;
405 goto fail;
408 if ((indirect = root->info.indirect_levels) > 1) {
409 ext4_warning(dir->i_sb, "Unimplemented inode hash depth: %#06x",
410 root->info.indirect_levels);
411 brelse(bh);
412 *err = ERR_BAD_DX_DIR;
413 goto fail;
416 entries = (struct dx_entry *) (((char *)&root->info) +
417 root->info.info_length);
419 if (dx_get_limit(entries) != dx_root_limit(dir,
420 root->info.info_length)) {
421 ext4_warning(dir->i_sb, "dx entry: limit != root limit");
422 brelse(bh);
423 *err = ERR_BAD_DX_DIR;
424 goto fail;
427 dxtrace(printk("Look up %x", hash));
428 while (1)
430 count = dx_get_count(entries);
431 if (!count || count > dx_get_limit(entries)) {
432 ext4_warning(dir->i_sb,
433 "dx entry: no count or count > limit");
434 brelse(bh);
435 *err = ERR_BAD_DX_DIR;
436 goto fail2;
439 p = entries + 1;
440 q = entries + count - 1;
441 while (p <= q)
443 m = p + (q - p)/2;
444 dxtrace(printk("."));
445 if (dx_get_hash(m) > hash)
446 q = m - 1;
447 else
448 p = m + 1;
451 if (0) // linear search cross check
453 unsigned n = count - 1;
454 at = entries;
455 while (n--)
457 dxtrace(printk(","));
458 if (dx_get_hash(++at) > hash)
460 at--;
461 break;
464 assert (at == p - 1);
467 at = p - 1;
468 dxtrace(printk(" %x->%u\n", at == entries? 0: dx_get_hash(at), dx_get_block(at)));
469 frame->bh = bh;
470 frame->entries = entries;
471 frame->at = at;
472 if (!indirect--) return frame;
473 if (!(bh = ext4_bread (NULL,dir, dx_get_block(at), 0, err)))
474 goto fail2;
475 at = entries = ((struct dx_node *) bh->b_data)->entries;
476 if (dx_get_limit(entries) != dx_node_limit (dir)) {
477 ext4_warning(dir->i_sb,
478 "dx entry: limit != node limit");
479 brelse(bh);
480 *err = ERR_BAD_DX_DIR;
481 goto fail2;
483 frame++;
484 frame->bh = NULL;
486 fail2:
487 while (frame >= frame_in) {
488 brelse(frame->bh);
489 frame--;
491 fail:
492 if (*err == ERR_BAD_DX_DIR)
493 ext4_warning(dir->i_sb,
494 "Corrupt dir inode %ld, running e2fsck is "
495 "recommended.", dir->i_ino);
496 return NULL;
499 static void dx_release (struct dx_frame *frames)
501 if (frames[0].bh == NULL)
502 return;
504 if (((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels)
505 brelse(frames[1].bh);
506 brelse(frames[0].bh);
510 * This function increments the frame pointer to search the next leaf
511 * block, and reads in the necessary intervening nodes if the search
512 * should be necessary. Whether or not the search is necessary is
513 * controlled by the hash parameter. If the hash value is even, then
514 * the search is only continued if the next block starts with that
515 * hash value. This is used if we are searching for a specific file.
517 * If the hash value is HASH_NB_ALWAYS, then always go to the next block.
519 * This function returns 1 if the caller should continue to search,
520 * or 0 if it should not. If there is an error reading one of the
521 * index blocks, it will a negative error code.
523 * If start_hash is non-null, it will be filled in with the starting
524 * hash of the next page.
526 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
527 struct dx_frame *frame,
528 struct dx_frame *frames,
529 __u32 *start_hash)
531 struct dx_frame *p;
532 struct buffer_head *bh;
533 int err, num_frames = 0;
534 __u32 bhash;
536 p = frame;
538 * Find the next leaf page by incrementing the frame pointer.
539 * If we run out of entries in the interior node, loop around and
540 * increment pointer in the parent node. When we break out of
541 * this loop, num_frames indicates the number of interior
542 * nodes need to be read.
544 while (1) {
545 if (++(p->at) < p->entries + dx_get_count(p->entries))
546 break;
547 if (p == frames)
548 return 0;
549 num_frames++;
550 p--;
554 * If the hash is 1, then continue only if the next page has a
555 * continuation hash of any value. This is used for readdir
556 * handling. Otherwise, check to see if the hash matches the
557 * desired contiuation hash. If it doesn't, return since
558 * there's no point to read in the successive index pages.
560 bhash = dx_get_hash(p->at);
561 if (start_hash)
562 *start_hash = bhash;
563 if ((hash & 1) == 0) {
564 if ((bhash & ~1) != hash)
565 return 0;
568 * If the hash is HASH_NB_ALWAYS, we always go to the next
569 * block so no check is necessary
571 while (num_frames--) {
572 if (!(bh = ext4_bread(NULL, dir, dx_get_block(p->at),
573 0, &err)))
574 return err; /* Failure */
575 p++;
576 brelse(p->bh);
577 p->bh = bh;
578 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
580 return 1;
585 * This function fills a red-black tree with information from a
586 * directory block. It returns the number directory entries loaded
587 * into the tree. If there is an error it is returned in err.
589 static int htree_dirblock_to_tree(struct file *dir_file,
590 struct inode *dir, ext4_lblk_t block,
591 struct dx_hash_info *hinfo,
592 __u32 start_hash, __u32 start_minor_hash)
594 struct buffer_head *bh;
595 struct ext4_dir_entry_2 *de, *top;
596 int err, count = 0;
598 dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
599 (unsigned long)block));
600 if (!(bh = ext4_bread (NULL, dir, block, 0, &err)))
601 return err;
603 de = (struct ext4_dir_entry_2 *) bh->b_data;
604 top = (struct ext4_dir_entry_2 *) ((char *) de +
605 dir->i_sb->s_blocksize -
606 EXT4_DIR_REC_LEN(0));
607 for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) {
608 if (!ext4_check_dir_entry("htree_dirblock_to_tree", dir, de, bh,
609 (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
610 +((char *)de - bh->b_data))) {
611 /* On error, skip the f_pos to the next block. */
612 dir_file->f_pos = (dir_file->f_pos |
613 (dir->i_sb->s_blocksize - 1)) + 1;
614 brelse(bh);
615 return count;
617 ext4fs_dirhash(de->name, de->name_len, hinfo);
618 if ((hinfo->hash < start_hash) ||
619 ((hinfo->hash == start_hash) &&
620 (hinfo->minor_hash < start_minor_hash)))
621 continue;
622 if (de->inode == 0)
623 continue;
624 if ((err = ext4_htree_store_dirent(dir_file,
625 hinfo->hash, hinfo->minor_hash, de)) != 0) {
626 brelse(bh);
627 return err;
629 count++;
631 brelse(bh);
632 return count;
637 * This function fills a red-black tree with information from a
638 * directory. We start scanning the directory in hash order, starting
639 * at start_hash and start_minor_hash.
641 * This function returns the number of entries inserted into the tree,
642 * or a negative error code.
644 int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
645 __u32 start_minor_hash, __u32 *next_hash)
647 struct dx_hash_info hinfo;
648 struct ext4_dir_entry_2 *de;
649 struct dx_frame frames[2], *frame;
650 struct inode *dir;
651 ext4_lblk_t block;
652 int count = 0;
653 int ret, err;
654 __u32 hashval;
656 dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
657 start_hash, start_minor_hash));
658 dir = dir_file->f_path.dentry->d_inode;
659 if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) {
660 hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
661 if (hinfo.hash_version <= DX_HASH_TEA)
662 hinfo.hash_version +=
663 EXT4_SB(dir->i_sb)->s_hash_unsigned;
664 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
665 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
666 start_hash, start_minor_hash);
667 *next_hash = ~0;
668 return count;
670 hinfo.hash = start_hash;
671 hinfo.minor_hash = 0;
672 frame = dx_probe(NULL, dir, &hinfo, frames, &err);
673 if (!frame)
674 return err;
676 /* Add '.' and '..' from the htree header */
677 if (!start_hash && !start_minor_hash) {
678 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
679 if ((err = ext4_htree_store_dirent(dir_file, 0, 0, de)) != 0)
680 goto errout;
681 count++;
683 if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
684 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
685 de = ext4_next_entry(de, dir->i_sb->s_blocksize);
686 if ((err = ext4_htree_store_dirent(dir_file, 2, 0, de)) != 0)
687 goto errout;
688 count++;
691 while (1) {
692 block = dx_get_block(frame->at);
693 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
694 start_hash, start_minor_hash);
695 if (ret < 0) {
696 err = ret;
697 goto errout;
699 count += ret;
700 hashval = ~0;
701 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
702 frame, frames, &hashval);
703 *next_hash = hashval;
704 if (ret < 0) {
705 err = ret;
706 goto errout;
709 * Stop if: (a) there are no more entries, or
710 * (b) we have inserted at least one entry and the
711 * next hash value is not a continuation
713 if ((ret == 0) ||
714 (count && ((hashval & 1) == 0)))
715 break;
717 dx_release(frames);
718 dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, "
719 "next hash: %x\n", count, *next_hash));
720 return count;
721 errout:
722 dx_release(frames);
723 return (err);
728 * Directory block splitting, compacting
732 * Create map of hash values, offsets, and sizes, stored at end of block.
733 * Returns number of entries mapped.
735 static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize,
736 struct dx_hash_info *hinfo,
737 struct dx_map_entry *map_tail)
739 int count = 0;
740 char *base = (char *) de;
741 struct dx_hash_info h = *hinfo;
743 while ((char *) de < base + blocksize) {
744 if (de->name_len && de->inode) {
745 ext4fs_dirhash(de->name, de->name_len, &h);
746 map_tail--;
747 map_tail->hash = h.hash;
748 map_tail->offs = ((char *) de - base)>>2;
749 map_tail->size = le16_to_cpu(de->rec_len);
750 count++;
751 cond_resched();
753 /* XXX: do we need to check rec_len == 0 case? -Chris */
754 de = ext4_next_entry(de, blocksize);
756 return count;
759 /* Sort map by hash value */
760 static void dx_sort_map (struct dx_map_entry *map, unsigned count)
762 struct dx_map_entry *p, *q, *top = map + count - 1;
763 int more;
764 /* Combsort until bubble sort doesn't suck */
765 while (count > 2) {
766 count = count*10/13;
767 if (count - 9 < 2) /* 9, 10 -> 11 */
768 count = 11;
769 for (p = top, q = p - count; q >= map; p--, q--)
770 if (p->hash < q->hash)
771 swap(*p, *q);
773 /* Garden variety bubble sort */
774 do {
775 more = 0;
776 q = top;
777 while (q-- > map) {
778 if (q[1].hash >= q[0].hash)
779 continue;
780 swap(*(q+1), *q);
781 more = 1;
783 } while(more);
786 static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
788 struct dx_entry *entries = frame->entries;
789 struct dx_entry *old = frame->at, *new = old + 1;
790 int count = dx_get_count(entries);
792 assert(count < dx_get_limit(entries));
793 assert(old < entries + count);
794 memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
795 dx_set_hash(new, hash);
796 dx_set_block(new, block);
797 dx_set_count(entries, count + 1);
800 static void ext4_update_dx_flag(struct inode *inode)
802 if (!EXT4_HAS_COMPAT_FEATURE(inode->i_sb,
803 EXT4_FEATURE_COMPAT_DIR_INDEX))
804 ext4_clear_inode_flag(inode, EXT4_INODE_INDEX);
808 * NOTE! unlike strncmp, ext4_match returns 1 for success, 0 for failure.
810 * `len <= EXT4_NAME_LEN' is guaranteed by caller.
811 * `de != NULL' is guaranteed by caller.
813 static inline int ext4_match (int len, const char * const name,
814 struct ext4_dir_entry_2 * de)
816 if (len != de->name_len)
817 return 0;
818 if (!de->inode)
819 return 0;
820 return !memcmp(name, de->name, len);
824 * Returns 0 if not found, -1 on failure, and 1 on success
826 static inline int search_dirblock(struct buffer_head *bh,
827 struct inode *dir,
828 const struct qstr *d_name,
829 unsigned int offset,
830 struct ext4_dir_entry_2 ** res_dir)
832 struct ext4_dir_entry_2 * de;
833 char * dlimit;
834 int de_len;
835 const char *name = d_name->name;
836 int namelen = d_name->len;
838 de = (struct ext4_dir_entry_2 *) bh->b_data;
839 dlimit = bh->b_data + dir->i_sb->s_blocksize;
840 while ((char *) de < dlimit) {
841 /* this code is executed quadratically often */
842 /* do minimal checking `by hand' */
844 if ((char *) de + namelen <= dlimit &&
845 ext4_match (namelen, name, de)) {
846 /* found a match - just to be sure, do a full check */
847 if (!ext4_check_dir_entry("ext4_find_entry",
848 dir, de, bh, offset))
849 return -1;
850 *res_dir = de;
851 return 1;
853 /* prevent looping on a bad block */
854 de_len = ext4_rec_len_from_disk(de->rec_len,
855 dir->i_sb->s_blocksize);
856 if (de_len <= 0)
857 return -1;
858 offset += de_len;
859 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
861 return 0;
866 * ext4_find_entry()
868 * finds an entry in the specified directory with the wanted name. It
869 * returns the cache buffer in which the entry was found, and the entry
870 * itself (as a parameter - res_dir). It does NOT read the inode of the
871 * entry - you'll have to do that yourself if you want to.
873 * The returned buffer_head has ->b_count elevated. The caller is expected
874 * to brelse() it when appropriate.
876 static struct buffer_head * ext4_find_entry (struct inode *dir,
877 const struct qstr *d_name,
878 struct ext4_dir_entry_2 ** res_dir)
880 struct super_block *sb;
881 struct buffer_head *bh_use[NAMEI_RA_SIZE];
882 struct buffer_head *bh, *ret = NULL;
883 ext4_lblk_t start, block, b;
884 int ra_max = 0; /* Number of bh's in the readahead
885 buffer, bh_use[] */
886 int ra_ptr = 0; /* Current index into readahead
887 buffer */
888 int num = 0;
889 ext4_lblk_t nblocks;
890 int i, err;
891 int namelen;
893 *res_dir = NULL;
894 sb = dir->i_sb;
895 namelen = d_name->len;
896 if (namelen > EXT4_NAME_LEN)
897 return NULL;
898 if (is_dx(dir)) {
899 bh = ext4_dx_find_entry(dir, d_name, res_dir, &err);
901 * On success, or if the error was file not found,
902 * return. Otherwise, fall back to doing a search the
903 * old fashioned way.
905 if (bh || (err != ERR_BAD_DX_DIR))
906 return bh;
907 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
908 "falling back\n"));
910 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
911 start = EXT4_I(dir)->i_dir_start_lookup;
912 if (start >= nblocks)
913 start = 0;
914 block = start;
915 restart:
916 do {
918 * We deal with the read-ahead logic here.
920 if (ra_ptr >= ra_max) {
921 /* Refill the readahead buffer */
922 ra_ptr = 0;
923 b = block;
924 for (ra_max = 0; ra_max < NAMEI_RA_SIZE; ra_max++) {
926 * Terminate if we reach the end of the
927 * directory and must wrap, or if our
928 * search has finished at this block.
930 if (b >= nblocks || (num && block == start)) {
931 bh_use[ra_max] = NULL;
932 break;
934 num++;
935 bh = ext4_getblk(NULL, dir, b++, 0, &err);
936 bh_use[ra_max] = bh;
937 if (bh)
938 ll_rw_block(READ_META, 1, &bh);
941 if ((bh = bh_use[ra_ptr++]) == NULL)
942 goto next;
943 wait_on_buffer(bh);
944 if (!buffer_uptodate(bh)) {
945 /* read error, skip block & hope for the best */
946 EXT4_ERROR_INODE(dir, "reading directory lblock %lu",
947 (unsigned long) block);
948 brelse(bh);
949 goto next;
951 i = search_dirblock(bh, dir, d_name,
952 block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
953 if (i == 1) {
954 EXT4_I(dir)->i_dir_start_lookup = block;
955 ret = bh;
956 goto cleanup_and_exit;
957 } else {
958 brelse(bh);
959 if (i < 0)
960 goto cleanup_and_exit;
962 next:
963 if (++block >= nblocks)
964 block = 0;
965 } while (block != start);
968 * If the directory has grown while we were searching, then
969 * search the last part of the directory before giving up.
971 block = nblocks;
972 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
973 if (block < nblocks) {
974 start = 0;
975 goto restart;
978 cleanup_and_exit:
979 /* Clean up the read-ahead blocks */
980 for (; ra_ptr < ra_max; ra_ptr++)
981 brelse(bh_use[ra_ptr]);
982 return ret;
985 static struct buffer_head * ext4_dx_find_entry(struct inode *dir, const struct qstr *d_name,
986 struct ext4_dir_entry_2 **res_dir, int *err)
988 struct super_block * sb;
989 struct dx_hash_info hinfo;
990 u32 hash;
991 struct dx_frame frames[2], *frame;
992 struct ext4_dir_entry_2 *de, *top;
993 struct buffer_head *bh;
994 ext4_lblk_t block;
995 int retval;
996 int namelen = d_name->len;
997 const u8 *name = d_name->name;
999 sb = dir->i_sb;
1000 /* NFS may look up ".." - look at dx_root directory block */
1001 if (namelen > 2 || name[0] != '.'||(name[1] != '.' && name[1] != '\0')){
1002 if (!(frame = dx_probe(d_name, dir, &hinfo, frames, err)))
1003 return NULL;
1004 } else {
1005 frame = frames;
1006 frame->bh = NULL; /* for dx_release() */
1007 frame->at = (struct dx_entry *)frames; /* hack for zero entry*/
1008 dx_set_block(frame->at, 0); /* dx_root block is 0 */
1010 hash = hinfo.hash;
1011 do {
1012 block = dx_get_block(frame->at);
1013 if (!(bh = ext4_bread (NULL,dir, block, 0, err)))
1014 goto errout;
1015 de = (struct ext4_dir_entry_2 *) bh->b_data;
1016 top = (struct ext4_dir_entry_2 *) ((char *) de + sb->s_blocksize -
1017 EXT4_DIR_REC_LEN(0));
1018 for (; de < top; de = ext4_next_entry(de, sb->s_blocksize)) {
1019 int off = (block << EXT4_BLOCK_SIZE_BITS(sb))
1020 + ((char *) de - bh->b_data);
1022 if (!ext4_check_dir_entry(__func__, dir, de, bh, off)) {
1023 brelse(bh);
1024 *err = ERR_BAD_DX_DIR;
1025 goto errout;
1028 if (ext4_match(namelen, name, de)) {
1029 *res_dir = de;
1030 dx_release(frames);
1031 return bh;
1034 brelse(bh);
1035 /* Check to see if we should continue to search */
1036 retval = ext4_htree_next_block(dir, hash, frame,
1037 frames, NULL);
1038 if (retval < 0) {
1039 ext4_warning(sb,
1040 "error reading index page in directory #%lu",
1041 dir->i_ino);
1042 *err = retval;
1043 goto errout;
1045 } while (retval == 1);
1047 *err = -ENOENT;
1048 errout:
1049 dxtrace(printk(KERN_DEBUG "%s not found\n", name));
1050 dx_release (frames);
1051 return NULL;
1054 static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
1056 struct inode *inode;
1057 struct ext4_dir_entry_2 *de;
1058 struct buffer_head *bh;
1060 if (dentry->d_name.len > EXT4_NAME_LEN)
1061 return ERR_PTR(-ENAMETOOLONG);
1063 bh = ext4_find_entry(dir, &dentry->d_name, &de);
1064 inode = NULL;
1065 if (bh) {
1066 __u32 ino = le32_to_cpu(de->inode);
1067 brelse(bh);
1068 if (!ext4_valid_inum(dir->i_sb, ino)) {
1069 EXT4_ERROR_INODE(dir, "bad inode number: %u", ino);
1070 return ERR_PTR(-EIO);
1072 inode = ext4_iget(dir->i_sb, ino);
1073 if (unlikely(IS_ERR(inode))) {
1074 if (PTR_ERR(inode) == -ESTALE) {
1075 EXT4_ERROR_INODE(dir,
1076 "deleted inode referenced: %u",
1077 ino);
1078 return ERR_PTR(-EIO);
1079 } else {
1080 return ERR_CAST(inode);
1084 return d_splice_alias(inode, dentry);
1088 struct dentry *ext4_get_parent(struct dentry *child)
1090 __u32 ino;
1091 struct inode *inode;
1092 static const struct qstr dotdot = {
1093 .name = "..",
1094 .len = 2,
1096 struct ext4_dir_entry_2 * de;
1097 struct buffer_head *bh;
1099 bh = ext4_find_entry(child->d_inode, &dotdot, &de);
1100 inode = NULL;
1101 if (!bh)
1102 return ERR_PTR(-ENOENT);
1103 ino = le32_to_cpu(de->inode);
1104 brelse(bh);
1106 if (!ext4_valid_inum(child->d_inode->i_sb, ino)) {
1107 EXT4_ERROR_INODE(child->d_inode,
1108 "bad parent inode number: %u", ino);
1109 return ERR_PTR(-EIO);
1112 return d_obtain_alias(ext4_iget(child->d_inode->i_sb, ino));
1115 #define S_SHIFT 12
1116 static unsigned char ext4_type_by_mode[S_IFMT >> S_SHIFT] = {
1117 [S_IFREG >> S_SHIFT] = EXT4_FT_REG_FILE,
1118 [S_IFDIR >> S_SHIFT] = EXT4_FT_DIR,
1119 [S_IFCHR >> S_SHIFT] = EXT4_FT_CHRDEV,
1120 [S_IFBLK >> S_SHIFT] = EXT4_FT_BLKDEV,
1121 [S_IFIFO >> S_SHIFT] = EXT4_FT_FIFO,
1122 [S_IFSOCK >> S_SHIFT] = EXT4_FT_SOCK,
1123 [S_IFLNK >> S_SHIFT] = EXT4_FT_SYMLINK,
1126 static inline void ext4_set_de_type(struct super_block *sb,
1127 struct ext4_dir_entry_2 *de,
1128 umode_t mode) {
1129 if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE))
1130 de->file_type = ext4_type_by_mode[(mode & S_IFMT)>>S_SHIFT];
1134 * Move count entries from end of map between two memory locations.
1135 * Returns pointer to last entry moved.
1137 static struct ext4_dir_entry_2 *
1138 dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count,
1139 unsigned blocksize)
1141 unsigned rec_len = 0;
1143 while (count--) {
1144 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
1145 (from + (map->offs<<2));
1146 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1147 memcpy (to, de, rec_len);
1148 ((struct ext4_dir_entry_2 *) to)->rec_len =
1149 ext4_rec_len_to_disk(rec_len, blocksize);
1150 de->inode = 0;
1151 map++;
1152 to += rec_len;
1154 return (struct ext4_dir_entry_2 *) (to - rec_len);
1158 * Compact each dir entry in the range to the minimal rec_len.
1159 * Returns pointer to last entry in range.
1161 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize)
1163 struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
1164 unsigned rec_len = 0;
1166 prev = to = de;
1167 while ((char*)de < base + blocksize) {
1168 next = ext4_next_entry(de, blocksize);
1169 if (de->inode && de->name_len) {
1170 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1171 if (de > to)
1172 memmove(to, de, rec_len);
1173 to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
1174 prev = to;
1175 to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
1177 de = next;
1179 return prev;
1183 * Split a full leaf block to make room for a new dir entry.
1184 * Allocate a new block, and move entries so that they are approx. equally full.
1185 * Returns pointer to de in block into which the new entry will be inserted.
1187 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
1188 struct buffer_head **bh,struct dx_frame *frame,
1189 struct dx_hash_info *hinfo, int *error)
1191 unsigned blocksize = dir->i_sb->s_blocksize;
1192 unsigned count, continued;
1193 struct buffer_head *bh2;
1194 ext4_lblk_t newblock;
1195 u32 hash2;
1196 struct dx_map_entry *map;
1197 char *data1 = (*bh)->b_data, *data2;
1198 unsigned split, move, size;
1199 struct ext4_dir_entry_2 *de = NULL, *de2;
1200 int err = 0, i;
1202 bh2 = ext4_append (handle, dir, &newblock, &err);
1203 if (!(bh2)) {
1204 brelse(*bh);
1205 *bh = NULL;
1206 goto errout;
1209 BUFFER_TRACE(*bh, "get_write_access");
1210 err = ext4_journal_get_write_access(handle, *bh);
1211 if (err)
1212 goto journal_error;
1214 BUFFER_TRACE(frame->bh, "get_write_access");
1215 err = ext4_journal_get_write_access(handle, frame->bh);
1216 if (err)
1217 goto journal_error;
1219 data2 = bh2->b_data;
1221 /* create map in the end of data2 block */
1222 map = (struct dx_map_entry *) (data2 + blocksize);
1223 count = dx_make_map((struct ext4_dir_entry_2 *) data1,
1224 blocksize, hinfo, map);
1225 map -= count;
1226 dx_sort_map(map, count);
1227 /* Split the existing block in the middle, size-wise */
1228 size = 0;
1229 move = 0;
1230 for (i = count-1; i >= 0; i--) {
1231 /* is more than half of this entry in 2nd half of the block? */
1232 if (size + map[i].size/2 > blocksize/2)
1233 break;
1234 size += map[i].size;
1235 move++;
1237 /* map index at which we will split */
1238 split = count - move;
1239 hash2 = map[split].hash;
1240 continued = hash2 == map[split - 1].hash;
1241 dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
1242 (unsigned long)dx_get_block(frame->at),
1243 hash2, split, count-split));
1245 /* Fancy dance to stay within two buffers */
1246 de2 = dx_move_dirents(data1, data2, map + split, count - split, blocksize);
1247 de = dx_pack_dirents(data1, blocksize);
1248 de->rec_len = ext4_rec_len_to_disk(data1 + blocksize - (char *) de,
1249 blocksize);
1250 de2->rec_len = ext4_rec_len_to_disk(data2 + blocksize - (char *) de2,
1251 blocksize);
1252 dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data1, blocksize, 1));
1253 dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data2, blocksize, 1));
1255 /* Which block gets the new entry? */
1256 if (hinfo->hash >= hash2)
1258 swap(*bh, bh2);
1259 de = de2;
1261 dx_insert_block(frame, hash2 + continued, newblock);
1262 err = ext4_handle_dirty_metadata(handle, dir, bh2);
1263 if (err)
1264 goto journal_error;
1265 err = ext4_handle_dirty_metadata(handle, dir, frame->bh);
1266 if (err)
1267 goto journal_error;
1268 brelse(bh2);
1269 dxtrace(dx_show_index("frame", frame->entries));
1270 return de;
1272 journal_error:
1273 brelse(*bh);
1274 brelse(bh2);
1275 *bh = NULL;
1276 ext4_std_error(dir->i_sb, err);
1277 errout:
1278 *error = err;
1279 return NULL;
1283 * Add a new entry into a directory (leaf) block. If de is non-NULL,
1284 * it points to a directory entry which is guaranteed to be large
1285 * enough for new directory entry. If de is NULL, then
1286 * add_dirent_to_buf will attempt search the directory block for
1287 * space. It will return -ENOSPC if no space is available, and -EIO
1288 * and -EEXIST if directory entry already exists.
1290 static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
1291 struct inode *inode, struct ext4_dir_entry_2 *de,
1292 struct buffer_head *bh)
1294 struct inode *dir = dentry->d_parent->d_inode;
1295 const char *name = dentry->d_name.name;
1296 int namelen = dentry->d_name.len;
1297 unsigned int offset = 0;
1298 unsigned int blocksize = dir->i_sb->s_blocksize;
1299 unsigned short reclen;
1300 int nlen, rlen, err;
1301 char *top;
1303 reclen = EXT4_DIR_REC_LEN(namelen);
1304 if (!de) {
1305 de = (struct ext4_dir_entry_2 *)bh->b_data;
1306 top = bh->b_data + blocksize - reclen;
1307 while ((char *) de <= top) {
1308 if (!ext4_check_dir_entry("ext4_add_entry", dir, de,
1309 bh, offset))
1310 return -EIO;
1311 if (ext4_match(namelen, name, de))
1312 return -EEXIST;
1313 nlen = EXT4_DIR_REC_LEN(de->name_len);
1314 rlen = ext4_rec_len_from_disk(de->rec_len, blocksize);
1315 if ((de->inode? rlen - nlen: rlen) >= reclen)
1316 break;
1317 de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
1318 offset += rlen;
1320 if ((char *) de > top)
1321 return -ENOSPC;
1323 BUFFER_TRACE(bh, "get_write_access");
1324 err = ext4_journal_get_write_access(handle, bh);
1325 if (err) {
1326 ext4_std_error(dir->i_sb, err);
1327 return err;
1330 /* By now the buffer is marked for journaling */
1331 nlen = EXT4_DIR_REC_LEN(de->name_len);
1332 rlen = ext4_rec_len_from_disk(de->rec_len, blocksize);
1333 if (de->inode) {
1334 struct ext4_dir_entry_2 *de1 = (struct ext4_dir_entry_2 *)((char *)de + nlen);
1335 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, blocksize);
1336 de->rec_len = ext4_rec_len_to_disk(nlen, blocksize);
1337 de = de1;
1339 de->file_type = EXT4_FT_UNKNOWN;
1340 if (inode) {
1341 de->inode = cpu_to_le32(inode->i_ino);
1342 ext4_set_de_type(dir->i_sb, de, inode->i_mode);
1343 } else
1344 de->inode = 0;
1345 de->name_len = namelen;
1346 memcpy(de->name, name, namelen);
1348 * XXX shouldn't update any times until successful
1349 * completion of syscall, but too many callers depend
1350 * on this.
1352 * XXX similarly, too many callers depend on
1353 * ext4_new_inode() setting the times, but error
1354 * recovery deletes the inode, so the worst that can
1355 * happen is that the times are slightly out of date
1356 * and/or different from the directory change time.
1358 dir->i_mtime = dir->i_ctime = ext4_current_time(dir);
1359 ext4_update_dx_flag(dir);
1360 dir->i_version++;
1361 ext4_mark_inode_dirty(handle, dir);
1362 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1363 err = ext4_handle_dirty_metadata(handle, dir, bh);
1364 if (err)
1365 ext4_std_error(dir->i_sb, err);
1366 return 0;
1370 * This converts a one block unindexed directory to a 3 block indexed
1371 * directory, and adds the dentry to the indexed directory.
1373 static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
1374 struct inode *inode, struct buffer_head *bh)
1376 struct inode *dir = dentry->d_parent->d_inode;
1377 const char *name = dentry->d_name.name;
1378 int namelen = dentry->d_name.len;
1379 struct buffer_head *bh2;
1380 struct dx_root *root;
1381 struct dx_frame frames[2], *frame;
1382 struct dx_entry *entries;
1383 struct ext4_dir_entry_2 *de, *de2;
1384 char *data1, *top;
1385 unsigned len;
1386 int retval;
1387 unsigned blocksize;
1388 struct dx_hash_info hinfo;
1389 ext4_lblk_t block;
1390 struct fake_dirent *fde;
1392 blocksize = dir->i_sb->s_blocksize;
1393 dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
1394 retval = ext4_journal_get_write_access(handle, bh);
1395 if (retval) {
1396 ext4_std_error(dir->i_sb, retval);
1397 brelse(bh);
1398 return retval;
1400 root = (struct dx_root *) bh->b_data;
1402 /* The 0th block becomes the root, move the dirents out */
1403 fde = &root->dotdot;
1404 de = (struct ext4_dir_entry_2 *)((char *)fde +
1405 ext4_rec_len_from_disk(fde->rec_len, blocksize));
1406 if ((char *) de >= (((char *) root) + blocksize)) {
1407 EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
1408 brelse(bh);
1409 return -EIO;
1411 len = ((char *) root) + blocksize - (char *) de;
1413 /* Allocate new block for the 0th block's dirents */
1414 bh2 = ext4_append(handle, dir, &block, &retval);
1415 if (!(bh2)) {
1416 brelse(bh);
1417 return retval;
1419 ext4_set_inode_flag(dir, EXT4_INODE_INDEX);
1420 data1 = bh2->b_data;
1422 memcpy (data1, de, len);
1423 de = (struct ext4_dir_entry_2 *) data1;
1424 top = data1 + len;
1425 while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
1426 de = de2;
1427 de->rec_len = ext4_rec_len_to_disk(data1 + blocksize - (char *) de,
1428 blocksize);
1429 /* Initialize the root; the dot dirents already exist */
1430 de = (struct ext4_dir_entry_2 *) (&root->dotdot);
1431 de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
1432 blocksize);
1433 memset (&root->info, 0, sizeof(root->info));
1434 root->info.info_length = sizeof(root->info);
1435 root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
1436 entries = root->entries;
1437 dx_set_block(entries, 1);
1438 dx_set_count(entries, 1);
1439 dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
1441 /* Initialize as for dx_probe */
1442 hinfo.hash_version = root->info.hash_version;
1443 if (hinfo.hash_version <= DX_HASH_TEA)
1444 hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
1445 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
1446 ext4fs_dirhash(name, namelen, &hinfo);
1447 frame = frames;
1448 frame->entries = entries;
1449 frame->at = entries;
1450 frame->bh = bh;
1451 bh = bh2;
1452 de = do_split(handle,dir, &bh, frame, &hinfo, &retval);
1453 dx_release (frames);
1454 if (!(de))
1455 return retval;
1457 retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
1458 brelse(bh);
1459 return retval;
1463 * ext4_add_entry()
1465 * adds a file entry to the specified directory, using the same
1466 * semantics as ext4_find_entry(). It returns NULL if it failed.
1468 * NOTE!! The inode part of 'de' is left at 0 - which means you
1469 * may not sleep between calling this and putting something into
1470 * the entry, as someone else might have used it while you slept.
1472 static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
1473 struct inode *inode)
1475 struct inode *dir = dentry->d_parent->d_inode;
1476 struct buffer_head *bh;
1477 struct ext4_dir_entry_2 *de;
1478 struct super_block *sb;
1479 int retval;
1480 int dx_fallback=0;
1481 unsigned blocksize;
1482 ext4_lblk_t block, blocks;
1484 sb = dir->i_sb;
1485 blocksize = sb->s_blocksize;
1486 if (!dentry->d_name.len)
1487 return -EINVAL;
1488 if (is_dx(dir)) {
1489 retval = ext4_dx_add_entry(handle, dentry, inode);
1490 if (!retval || (retval != ERR_BAD_DX_DIR))
1491 return retval;
1492 ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
1493 dx_fallback++;
1494 ext4_mark_inode_dirty(handle, dir);
1496 blocks = dir->i_size >> sb->s_blocksize_bits;
1497 for (block = 0; block < blocks; block++) {
1498 bh = ext4_bread(handle, dir, block, 0, &retval);
1499 if(!bh)
1500 return retval;
1501 retval = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
1502 if (retval != -ENOSPC) {
1503 brelse(bh);
1504 return retval;
1507 if (blocks == 1 && !dx_fallback &&
1508 EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX))
1509 return make_indexed_dir(handle, dentry, inode, bh);
1510 brelse(bh);
1512 bh = ext4_append(handle, dir, &block, &retval);
1513 if (!bh)
1514 return retval;
1515 de = (struct ext4_dir_entry_2 *) bh->b_data;
1516 de->inode = 0;
1517 de->rec_len = ext4_rec_len_to_disk(blocksize, blocksize);
1518 retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
1519 brelse(bh);
1520 if (retval == 0)
1521 ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY);
1522 return retval;
1526 * Returns 0 for success, or a negative error value
1528 static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
1529 struct inode *inode)
1531 struct dx_frame frames[2], *frame;
1532 struct dx_entry *entries, *at;
1533 struct dx_hash_info hinfo;
1534 struct buffer_head *bh;
1535 struct inode *dir = dentry->d_parent->d_inode;
1536 struct super_block *sb = dir->i_sb;
1537 struct ext4_dir_entry_2 *de;
1538 int err;
1540 frame = dx_probe(&dentry->d_name, dir, &hinfo, frames, &err);
1541 if (!frame)
1542 return err;
1543 entries = frame->entries;
1544 at = frame->at;
1546 if (!(bh = ext4_bread(handle,dir, dx_get_block(frame->at), 0, &err)))
1547 goto cleanup;
1549 BUFFER_TRACE(bh, "get_write_access");
1550 err = ext4_journal_get_write_access(handle, bh);
1551 if (err)
1552 goto journal_error;
1554 err = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
1555 if (err != -ENOSPC)
1556 goto cleanup;
1558 /* Block full, should compress but for now just split */
1559 dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
1560 dx_get_count(entries), dx_get_limit(entries)));
1561 /* Need to split index? */
1562 if (dx_get_count(entries) == dx_get_limit(entries)) {
1563 ext4_lblk_t newblock;
1564 unsigned icount = dx_get_count(entries);
1565 int levels = frame - frames;
1566 struct dx_entry *entries2;
1567 struct dx_node *node2;
1568 struct buffer_head *bh2;
1570 if (levels && (dx_get_count(frames->entries) ==
1571 dx_get_limit(frames->entries))) {
1572 ext4_warning(sb, "Directory index full!");
1573 err = -ENOSPC;
1574 goto cleanup;
1576 bh2 = ext4_append (handle, dir, &newblock, &err);
1577 if (!(bh2))
1578 goto cleanup;
1579 node2 = (struct dx_node *)(bh2->b_data);
1580 entries2 = node2->entries;
1581 memset(&node2->fake, 0, sizeof(struct fake_dirent));
1582 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
1583 sb->s_blocksize);
1584 BUFFER_TRACE(frame->bh, "get_write_access");
1585 err = ext4_journal_get_write_access(handle, frame->bh);
1586 if (err)
1587 goto journal_error;
1588 if (levels) {
1589 unsigned icount1 = icount/2, icount2 = icount - icount1;
1590 unsigned hash2 = dx_get_hash(entries + icount1);
1591 dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
1592 icount1, icount2));
1594 BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
1595 err = ext4_journal_get_write_access(handle,
1596 frames[0].bh);
1597 if (err)
1598 goto journal_error;
1600 memcpy((char *) entries2, (char *) (entries + icount1),
1601 icount2 * sizeof(struct dx_entry));
1602 dx_set_count(entries, icount1);
1603 dx_set_count(entries2, icount2);
1604 dx_set_limit(entries2, dx_node_limit(dir));
1606 /* Which index block gets the new entry? */
1607 if (at - entries >= icount1) {
1608 frame->at = at = at - entries - icount1 + entries2;
1609 frame->entries = entries = entries2;
1610 swap(frame->bh, bh2);
1612 dx_insert_block(frames + 0, hash2, newblock);
1613 dxtrace(dx_show_index("node", frames[1].entries));
1614 dxtrace(dx_show_index("node",
1615 ((struct dx_node *) bh2->b_data)->entries));
1616 err = ext4_handle_dirty_metadata(handle, inode, bh2);
1617 if (err)
1618 goto journal_error;
1619 brelse (bh2);
1620 } else {
1621 dxtrace(printk(KERN_DEBUG
1622 "Creating second level index...\n"));
1623 memcpy((char *) entries2, (char *) entries,
1624 icount * sizeof(struct dx_entry));
1625 dx_set_limit(entries2, dx_node_limit(dir));
1627 /* Set up root */
1628 dx_set_count(entries, 1);
1629 dx_set_block(entries + 0, newblock);
1630 ((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels = 1;
1632 /* Add new access path frame */
1633 frame = frames + 1;
1634 frame->at = at = at - entries + entries2;
1635 frame->entries = entries = entries2;
1636 frame->bh = bh2;
1637 err = ext4_journal_get_write_access(handle,
1638 frame->bh);
1639 if (err)
1640 goto journal_error;
1642 ext4_handle_dirty_metadata(handle, inode, frames[0].bh);
1644 de = do_split(handle, dir, &bh, frame, &hinfo, &err);
1645 if (!de)
1646 goto cleanup;
1647 err = add_dirent_to_buf(handle, dentry, inode, de, bh);
1648 goto cleanup;
1650 journal_error:
1651 ext4_std_error(dir->i_sb, err);
1652 cleanup:
1653 if (bh)
1654 brelse(bh);
1655 dx_release(frames);
1656 return err;
1660 * ext4_delete_entry deletes a directory entry by merging it with the
1661 * previous entry
1663 static int ext4_delete_entry(handle_t *handle,
1664 struct inode *dir,
1665 struct ext4_dir_entry_2 *de_del,
1666 struct buffer_head *bh)
1668 struct ext4_dir_entry_2 *de, *pde;
1669 unsigned int blocksize = dir->i_sb->s_blocksize;
1670 int i;
1672 i = 0;
1673 pde = NULL;
1674 de = (struct ext4_dir_entry_2 *) bh->b_data;
1675 while (i < bh->b_size) {
1676 if (!ext4_check_dir_entry("ext4_delete_entry", dir, de, bh, i))
1677 return -EIO;
1678 if (de == de_del) {
1679 BUFFER_TRACE(bh, "get_write_access");
1680 ext4_journal_get_write_access(handle, bh);
1681 if (pde)
1682 pde->rec_len = ext4_rec_len_to_disk(
1683 ext4_rec_len_from_disk(pde->rec_len,
1684 blocksize) +
1685 ext4_rec_len_from_disk(de->rec_len,
1686 blocksize),
1687 blocksize);
1688 else
1689 de->inode = 0;
1690 dir->i_version++;
1691 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1692 ext4_handle_dirty_metadata(handle, dir, bh);
1693 return 0;
1695 i += ext4_rec_len_from_disk(de->rec_len, blocksize);
1696 pde = de;
1697 de = ext4_next_entry(de, blocksize);
1699 return -ENOENT;
1703 * DIR_NLINK feature is set if 1) nlinks > EXT4_LINK_MAX or 2) nlinks == 2,
1704 * since this indicates that nlinks count was previously 1.
1706 static void ext4_inc_count(handle_t *handle, struct inode *inode)
1708 inc_nlink(inode);
1709 if (is_dx(inode) && inode->i_nlink > 1) {
1710 /* limit is 16-bit i_links_count */
1711 if (inode->i_nlink >= EXT4_LINK_MAX || inode->i_nlink == 2) {
1712 inode->i_nlink = 1;
1713 EXT4_SET_RO_COMPAT_FEATURE(inode->i_sb,
1714 EXT4_FEATURE_RO_COMPAT_DIR_NLINK);
1720 * If a directory had nlink == 1, then we should let it be 1. This indicates
1721 * directory has >EXT4_LINK_MAX subdirs.
1723 static void ext4_dec_count(handle_t *handle, struct inode *inode)
1725 drop_nlink(inode);
1726 if (S_ISDIR(inode->i_mode) && inode->i_nlink == 0)
1727 inc_nlink(inode);
1731 static int ext4_add_nondir(handle_t *handle,
1732 struct dentry *dentry, struct inode *inode)
1734 int err = ext4_add_entry(handle, dentry, inode);
1735 if (!err) {
1736 ext4_mark_inode_dirty(handle, inode);
1737 d_instantiate(dentry, inode);
1738 unlock_new_inode(inode);
1739 return 0;
1741 drop_nlink(inode);
1742 unlock_new_inode(inode);
1743 iput(inode);
1744 return err;
1748 * By the time this is called, we already have created
1749 * the directory cache entry for the new file, but it
1750 * is so far negative - it has no inode.
1752 * If the create succeeds, we fill in the inode information
1753 * with d_instantiate().
1755 static int ext4_create(struct inode *dir, struct dentry *dentry, int mode,
1756 struct nameidata *nd)
1758 handle_t *handle;
1759 struct inode *inode;
1760 int err, retries = 0;
1762 dquot_initialize(dir);
1764 retry:
1765 handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
1766 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
1767 EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
1768 if (IS_ERR(handle))
1769 return PTR_ERR(handle);
1771 if (IS_DIRSYNC(dir))
1772 ext4_handle_sync(handle);
1774 inode = ext4_new_inode(handle, dir, mode, &dentry->d_name, 0);
1775 err = PTR_ERR(inode);
1776 if (!IS_ERR(inode)) {
1777 inode->i_op = &ext4_file_inode_operations;
1778 inode->i_fop = &ext4_file_operations;
1779 ext4_set_aops(inode);
1780 err = ext4_add_nondir(handle, dentry, inode);
1782 ext4_journal_stop(handle);
1783 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
1784 goto retry;
1785 return err;
1788 static int ext4_mknod(struct inode *dir, struct dentry *dentry,
1789 int mode, dev_t rdev)
1791 handle_t *handle;
1792 struct inode *inode;
1793 int err, retries = 0;
1795 if (!new_valid_dev(rdev))
1796 return -EINVAL;
1798 dquot_initialize(dir);
1800 retry:
1801 handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
1802 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
1803 EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
1804 if (IS_ERR(handle))
1805 return PTR_ERR(handle);
1807 if (IS_DIRSYNC(dir))
1808 ext4_handle_sync(handle);
1810 inode = ext4_new_inode(handle, dir, mode, &dentry->d_name, 0);
1811 err = PTR_ERR(inode);
1812 if (!IS_ERR(inode)) {
1813 init_special_inode(inode, inode->i_mode, rdev);
1814 #ifdef CONFIG_EXT4_FS_XATTR
1815 inode->i_op = &ext4_special_inode_operations;
1816 #endif
1817 err = ext4_add_nondir(handle, dentry, inode);
1819 ext4_journal_stop(handle);
1820 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
1821 goto retry;
1822 return err;
1825 static int ext4_mkdir(struct inode *dir, struct dentry *dentry, int mode)
1827 handle_t *handle;
1828 struct inode *inode;
1829 struct buffer_head *dir_block;
1830 struct ext4_dir_entry_2 *de;
1831 unsigned int blocksize = dir->i_sb->s_blocksize;
1832 int err, retries = 0;
1834 if (EXT4_DIR_LINK_MAX(dir))
1835 return -EMLINK;
1837 dquot_initialize(dir);
1839 retry:
1840 handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
1841 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
1842 EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
1843 if (IS_ERR(handle))
1844 return PTR_ERR(handle);
1846 if (IS_DIRSYNC(dir))
1847 ext4_handle_sync(handle);
1849 inode = ext4_new_inode(handle, dir, S_IFDIR | mode,
1850 &dentry->d_name, 0);
1851 err = PTR_ERR(inode);
1852 if (IS_ERR(inode))
1853 goto out_stop;
1855 inode->i_op = &ext4_dir_inode_operations;
1856 inode->i_fop = &ext4_dir_operations;
1857 inode->i_size = EXT4_I(inode)->i_disksize = inode->i_sb->s_blocksize;
1858 dir_block = ext4_bread(handle, inode, 0, 1, &err);
1859 if (!dir_block)
1860 goto out_clear_inode;
1861 BUFFER_TRACE(dir_block, "get_write_access");
1862 ext4_journal_get_write_access(handle, dir_block);
1863 de = (struct ext4_dir_entry_2 *) dir_block->b_data;
1864 de->inode = cpu_to_le32(inode->i_ino);
1865 de->name_len = 1;
1866 de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
1867 blocksize);
1868 strcpy(de->name, ".");
1869 ext4_set_de_type(dir->i_sb, de, S_IFDIR);
1870 de = ext4_next_entry(de, blocksize);
1871 de->inode = cpu_to_le32(dir->i_ino);
1872 de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(1),
1873 blocksize);
1874 de->name_len = 2;
1875 strcpy(de->name, "..");
1876 ext4_set_de_type(dir->i_sb, de, S_IFDIR);
1877 inode->i_nlink = 2;
1878 BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
1879 ext4_handle_dirty_metadata(handle, dir, dir_block);
1880 brelse(dir_block);
1881 ext4_mark_inode_dirty(handle, inode);
1882 err = ext4_add_entry(handle, dentry, inode);
1883 if (err) {
1884 out_clear_inode:
1885 clear_nlink(inode);
1886 unlock_new_inode(inode);
1887 ext4_mark_inode_dirty(handle, inode);
1888 iput(inode);
1889 goto out_stop;
1891 ext4_inc_count(handle, dir);
1892 ext4_update_dx_flag(dir);
1893 ext4_mark_inode_dirty(handle, dir);
1894 d_instantiate(dentry, inode);
1895 unlock_new_inode(inode);
1896 out_stop:
1897 ext4_journal_stop(handle);
1898 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
1899 goto retry;
1900 return err;
1904 * routine to check that the specified directory is empty (for rmdir)
1906 static int empty_dir(struct inode *inode)
1908 unsigned int offset;
1909 struct buffer_head *bh;
1910 struct ext4_dir_entry_2 *de, *de1;
1911 struct super_block *sb;
1912 int err = 0;
1914 sb = inode->i_sb;
1915 if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2) ||
1916 !(bh = ext4_bread(NULL, inode, 0, 0, &err))) {
1917 if (err)
1918 EXT4_ERROR_INODE(inode,
1919 "error %d reading directory lblock 0", err);
1920 else
1921 ext4_warning(inode->i_sb,
1922 "bad directory (dir #%lu) - no data block",
1923 inode->i_ino);
1924 return 1;
1926 de = (struct ext4_dir_entry_2 *) bh->b_data;
1927 de1 = ext4_next_entry(de, sb->s_blocksize);
1928 if (le32_to_cpu(de->inode) != inode->i_ino ||
1929 !le32_to_cpu(de1->inode) ||
1930 strcmp(".", de->name) ||
1931 strcmp("..", de1->name)) {
1932 ext4_warning(inode->i_sb,
1933 "bad directory (dir #%lu) - no `.' or `..'",
1934 inode->i_ino);
1935 brelse(bh);
1936 return 1;
1938 offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) +
1939 ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize);
1940 de = ext4_next_entry(de1, sb->s_blocksize);
1941 while (offset < inode->i_size) {
1942 if (!bh ||
1943 (void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
1944 unsigned int lblock;
1945 err = 0;
1946 brelse(bh);
1947 lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb);
1948 bh = ext4_bread(NULL, inode, lblock, 0, &err);
1949 if (!bh) {
1950 if (err)
1951 EXT4_ERROR_INODE(inode,
1952 "error %d reading directory "
1953 "lblock %u", err, lblock);
1954 offset += sb->s_blocksize;
1955 continue;
1957 de = (struct ext4_dir_entry_2 *) bh->b_data;
1959 if (!ext4_check_dir_entry("empty_dir", inode, de, bh, offset)) {
1960 de = (struct ext4_dir_entry_2 *)(bh->b_data +
1961 sb->s_blocksize);
1962 offset = (offset | (sb->s_blocksize - 1)) + 1;
1963 continue;
1965 if (le32_to_cpu(de->inode)) {
1966 brelse(bh);
1967 return 0;
1969 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
1970 de = ext4_next_entry(de, sb->s_blocksize);
1972 brelse(bh);
1973 return 1;
1976 /* ext4_orphan_add() links an unlinked or truncated inode into a list of
1977 * such inodes, starting at the superblock, in case we crash before the
1978 * file is closed/deleted, or in case the inode truncate spans multiple
1979 * transactions and the last transaction is not recovered after a crash.
1981 * At filesystem recovery time, we walk this list deleting unlinked
1982 * inodes and truncating linked inodes in ext4_orphan_cleanup().
1984 int ext4_orphan_add(handle_t *handle, struct inode *inode)
1986 struct super_block *sb = inode->i_sb;
1987 struct ext4_iloc iloc;
1988 int err = 0, rc;
1990 if (!ext4_handle_valid(handle))
1991 return 0;
1993 mutex_lock(&EXT4_SB(sb)->s_orphan_lock);
1994 if (!list_empty(&EXT4_I(inode)->i_orphan))
1995 goto out_unlock;
1997 /* Orphan handling is only valid for files with data blocks
1998 * being truncated, or files being unlinked. */
2000 /* @@@ FIXME: Observation from aviro:
2001 * I think I can trigger J_ASSERT in ext4_orphan_add(). We block
2002 * here (on s_orphan_lock), so race with ext4_link() which might bump
2003 * ->i_nlink. For, say it, character device. Not a regular file,
2004 * not a directory, not a symlink and ->i_nlink > 0.
2006 * tytso, 4/25/2009: I'm not sure how that could happen;
2007 * shouldn't the fs core protect us from these sort of
2008 * unlink()/link() races?
2010 J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2011 S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
2013 BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access");
2014 err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
2015 if (err)
2016 goto out_unlock;
2018 err = ext4_reserve_inode_write(handle, inode, &iloc);
2019 if (err)
2020 goto out_unlock;
2022 * Due to previous errors inode may be already a part of on-disk
2023 * orphan list. If so skip on-disk list modification.
2025 if (NEXT_ORPHAN(inode) && NEXT_ORPHAN(inode) <=
2026 (le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count)))
2027 goto mem_insert;
2029 /* Insert this inode at the head of the on-disk orphan list... */
2030 NEXT_ORPHAN(inode) = le32_to_cpu(EXT4_SB(sb)->s_es->s_last_orphan);
2031 EXT4_SB(sb)->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
2032 err = ext4_handle_dirty_metadata(handle, NULL, EXT4_SB(sb)->s_sbh);
2033 rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
2034 if (!err)
2035 err = rc;
2037 /* Only add to the head of the in-memory list if all the
2038 * previous operations succeeded. If the orphan_add is going to
2039 * fail (possibly taking the journal offline), we can't risk
2040 * leaving the inode on the orphan list: stray orphan-list
2041 * entries can cause panics at unmount time.
2043 * This is safe: on error we're going to ignore the orphan list
2044 * anyway on the next recovery. */
2045 mem_insert:
2046 if (!err)
2047 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2049 jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
2050 jbd_debug(4, "orphan inode %lu will point to %d\n",
2051 inode->i_ino, NEXT_ORPHAN(inode));
2052 out_unlock:
2053 mutex_unlock(&EXT4_SB(sb)->s_orphan_lock);
2054 ext4_std_error(inode->i_sb, err);
2055 return err;
2059 * ext4_orphan_del() removes an unlinked or truncated inode from the list
2060 * of such inodes stored on disk, because it is finally being cleaned up.
2062 int ext4_orphan_del(handle_t *handle, struct inode *inode)
2064 struct list_head *prev;
2065 struct ext4_inode_info *ei = EXT4_I(inode);
2066 struct ext4_sb_info *sbi;
2067 __u32 ino_next;
2068 struct ext4_iloc iloc;
2069 int err = 0;
2071 /* ext4_handle_valid() assumes a valid handle_t pointer */
2072 if (handle && !ext4_handle_valid(handle))
2073 return 0;
2075 mutex_lock(&EXT4_SB(inode->i_sb)->s_orphan_lock);
2076 if (list_empty(&ei->i_orphan))
2077 goto out;
2079 ino_next = NEXT_ORPHAN(inode);
2080 prev = ei->i_orphan.prev;
2081 sbi = EXT4_SB(inode->i_sb);
2083 jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
2085 list_del_init(&ei->i_orphan);
2087 /* If we're on an error path, we may not have a valid
2088 * transaction handle with which to update the orphan list on
2089 * disk, but we still need to remove the inode from the linked
2090 * list in memory. */
2091 if (sbi->s_journal && !handle)
2092 goto out;
2094 err = ext4_reserve_inode_write(handle, inode, &iloc);
2095 if (err)
2096 goto out_err;
2098 if (prev == &sbi->s_orphan) {
2099 jbd_debug(4, "superblock will point to %u\n", ino_next);
2100 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2101 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2102 if (err)
2103 goto out_brelse;
2104 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
2105 err = ext4_handle_dirty_metadata(handle, NULL, sbi->s_sbh);
2106 } else {
2107 struct ext4_iloc iloc2;
2108 struct inode *i_prev =
2109 &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
2111 jbd_debug(4, "orphan inode %lu will point to %u\n",
2112 i_prev->i_ino, ino_next);
2113 err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
2114 if (err)
2115 goto out_brelse;
2116 NEXT_ORPHAN(i_prev) = ino_next;
2117 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
2119 if (err)
2120 goto out_brelse;
2121 NEXT_ORPHAN(inode) = 0;
2122 err = ext4_mark_iloc_dirty(handle, inode, &iloc);
2124 out_err:
2125 ext4_std_error(inode->i_sb, err);
2126 out:
2127 mutex_unlock(&EXT4_SB(inode->i_sb)->s_orphan_lock);
2128 return err;
2130 out_brelse:
2131 brelse(iloc.bh);
2132 goto out_err;
2135 static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
2137 int retval;
2138 struct inode *inode;
2139 struct buffer_head *bh;
2140 struct ext4_dir_entry_2 *de;
2141 handle_t *handle;
2143 /* Initialize quotas before so that eventual writes go in
2144 * separate transaction */
2145 dquot_initialize(dir);
2146 dquot_initialize(dentry->d_inode);
2148 handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb));
2149 if (IS_ERR(handle))
2150 return PTR_ERR(handle);
2152 retval = -ENOENT;
2153 bh = ext4_find_entry(dir, &dentry->d_name, &de);
2154 if (!bh)
2155 goto end_rmdir;
2157 if (IS_DIRSYNC(dir))
2158 ext4_handle_sync(handle);
2160 inode = dentry->d_inode;
2162 retval = -EIO;
2163 if (le32_to_cpu(de->inode) != inode->i_ino)
2164 goto end_rmdir;
2166 retval = -ENOTEMPTY;
2167 if (!empty_dir(inode))
2168 goto end_rmdir;
2170 retval = ext4_delete_entry(handle, dir, de, bh);
2171 if (retval)
2172 goto end_rmdir;
2173 if (!EXT4_DIR_LINK_EMPTY(inode))
2174 ext4_warning(inode->i_sb,
2175 "empty directory has too many links (%d)",
2176 inode->i_nlink);
2177 inode->i_version++;
2178 clear_nlink(inode);
2179 /* There's no need to set i_disksize: the fact that i_nlink is
2180 * zero will ensure that the right thing happens during any
2181 * recovery. */
2182 inode->i_size = 0;
2183 ext4_orphan_add(handle, inode);
2184 inode->i_ctime = dir->i_ctime = dir->i_mtime = ext4_current_time(inode);
2185 ext4_mark_inode_dirty(handle, inode);
2186 ext4_dec_count(handle, dir);
2187 ext4_update_dx_flag(dir);
2188 ext4_mark_inode_dirty(handle, dir);
2190 end_rmdir:
2191 ext4_journal_stop(handle);
2192 brelse(bh);
2193 return retval;
2196 static int ext4_unlink(struct inode *dir, struct dentry *dentry)
2198 int retval;
2199 struct inode *inode;
2200 struct buffer_head *bh;
2201 struct ext4_dir_entry_2 *de;
2202 handle_t *handle;
2204 /* Initialize quotas before so that eventual writes go
2205 * in separate transaction */
2206 dquot_initialize(dir);
2207 dquot_initialize(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,
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 dquot_initialize(dir);
2265 retry:
2266 handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2267 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 5 +
2268 EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
2269 if (IS_ERR(handle))
2270 return PTR_ERR(handle);
2272 if (IS_DIRSYNC(dir))
2273 ext4_handle_sync(handle);
2275 inode = ext4_new_inode(handle, dir, S_IFLNK|S_IRWXUGO,
2276 &dentry->d_name, 0);
2277 err = PTR_ERR(inode);
2278 if (IS_ERR(inode))
2279 goto out_stop;
2281 if (l > sizeof(EXT4_I(inode)->i_data)) {
2282 inode->i_op = &ext4_symlink_inode_operations;
2283 ext4_set_aops(inode);
2285 * page_symlink() calls into ext4_prepare/commit_write.
2286 * We have a transaction open. All is sweetness. It also sets
2287 * i_size in generic_commit_write().
2289 err = __page_symlink(inode, symname, l, 1);
2290 if (err) {
2291 clear_nlink(inode);
2292 unlock_new_inode(inode);
2293 ext4_mark_inode_dirty(handle, inode);
2294 iput(inode);
2295 goto out_stop;
2297 } else {
2298 /* clear the extent format for fast symlink */
2299 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
2300 inode->i_op = &ext4_fast_symlink_inode_operations;
2301 memcpy((char *)&EXT4_I(inode)->i_data, symname, l);
2302 inode->i_size = l-1;
2304 EXT4_I(inode)->i_disksize = inode->i_size;
2305 err = ext4_add_nondir(handle, dentry, inode);
2306 out_stop:
2307 ext4_journal_stop(handle);
2308 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2309 goto retry;
2310 return err;
2313 static int ext4_link(struct dentry *old_dentry,
2314 struct inode *dir, struct dentry *dentry)
2316 handle_t *handle;
2317 struct inode *inode = old_dentry->d_inode;
2318 int err, retries = 0;
2320 if (inode->i_nlink >= EXT4_LINK_MAX)
2321 return -EMLINK;
2323 dquot_initialize(dir);
2326 * Return -ENOENT if we've raced with unlink and i_nlink is 0. Doing
2327 * otherwise has the potential to corrupt the orphan inode list.
2329 if (inode->i_nlink == 0)
2330 return -ENOENT;
2332 retry:
2333 handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2334 EXT4_INDEX_EXTRA_TRANS_BLOCKS);
2335 if (IS_ERR(handle))
2336 return PTR_ERR(handle);
2338 if (IS_DIRSYNC(dir))
2339 ext4_handle_sync(handle);
2341 inode->i_ctime = ext4_current_time(inode);
2342 ext4_inc_count(handle, inode);
2343 atomic_inc(&inode->i_count);
2345 err = ext4_add_entry(handle, dentry, inode);
2346 if (!err) {
2347 ext4_mark_inode_dirty(handle, inode);
2348 d_instantiate(dentry, inode);
2349 } else {
2350 drop_nlink(inode);
2351 iput(inode);
2353 ext4_journal_stop(handle);
2354 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2355 goto retry;
2356 return err;
2359 #define PARENT_INO(buffer, size) \
2360 (ext4_next_entry((struct ext4_dir_entry_2 *)(buffer), size)->inode)
2363 * Anybody can rename anything with this: the permission checks are left to the
2364 * higher-level routines.
2366 static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
2367 struct inode *new_dir, struct dentry *new_dentry)
2369 handle_t *handle;
2370 struct inode *old_inode, *new_inode;
2371 struct buffer_head *old_bh, *new_bh, *dir_bh;
2372 struct ext4_dir_entry_2 *old_de, *new_de;
2373 int retval, force_da_alloc = 0;
2375 dquot_initialize(old_dir);
2376 dquot_initialize(new_dir);
2378 old_bh = new_bh = dir_bh = NULL;
2380 /* Initialize quotas before so that eventual writes go
2381 * in separate transaction */
2382 if (new_dentry->d_inode)
2383 dquot_initialize(new_dentry->d_inode);
2384 handle = ext4_journal_start(old_dir, 2 *
2385 EXT4_DATA_TRANS_BLOCKS(old_dir->i_sb) +
2386 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
2387 if (IS_ERR(handle))
2388 return PTR_ERR(handle);
2390 if (IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir))
2391 ext4_handle_sync(handle);
2393 old_bh = ext4_find_entry(old_dir, &old_dentry->d_name, &old_de);
2395 * Check for inode number is _not_ due to possible IO errors.
2396 * We might rmdir the source, keep it as pwd of some process
2397 * and merrily kill the link to whatever was created under the
2398 * same name. Goodbye sticky bit ;-<
2400 old_inode = old_dentry->d_inode;
2401 retval = -ENOENT;
2402 if (!old_bh || le32_to_cpu(old_de->inode) != old_inode->i_ino)
2403 goto end_rename;
2405 new_inode = new_dentry->d_inode;
2406 new_bh = ext4_find_entry(new_dir, &new_dentry->d_name, &new_de);
2407 if (new_bh) {
2408 if (!new_inode) {
2409 brelse(new_bh);
2410 new_bh = NULL;
2413 if (S_ISDIR(old_inode->i_mode)) {
2414 if (new_inode) {
2415 retval = -ENOTEMPTY;
2416 if (!empty_dir(new_inode))
2417 goto end_rename;
2419 retval = -EIO;
2420 dir_bh = ext4_bread(handle, old_inode, 0, 0, &retval);
2421 if (!dir_bh)
2422 goto end_rename;
2423 if (le32_to_cpu(PARENT_INO(dir_bh->b_data,
2424 old_dir->i_sb->s_blocksize)) != old_dir->i_ino)
2425 goto end_rename;
2426 retval = -EMLINK;
2427 if (!new_inode && new_dir != old_dir &&
2428 EXT4_DIR_LINK_MAX(new_dir))
2429 goto end_rename;
2431 if (!new_bh) {
2432 retval = ext4_add_entry(handle, new_dentry, old_inode);
2433 if (retval)
2434 goto end_rename;
2435 } else {
2436 BUFFER_TRACE(new_bh, "get write access");
2437 ext4_journal_get_write_access(handle, new_bh);
2438 new_de->inode = cpu_to_le32(old_inode->i_ino);
2439 if (EXT4_HAS_INCOMPAT_FEATURE(new_dir->i_sb,
2440 EXT4_FEATURE_INCOMPAT_FILETYPE))
2441 new_de->file_type = old_de->file_type;
2442 new_dir->i_version++;
2443 new_dir->i_ctime = new_dir->i_mtime =
2444 ext4_current_time(new_dir);
2445 ext4_mark_inode_dirty(handle, new_dir);
2446 BUFFER_TRACE(new_bh, "call ext4_handle_dirty_metadata");
2447 ext4_handle_dirty_metadata(handle, new_dir, new_bh);
2448 brelse(new_bh);
2449 new_bh = NULL;
2453 * Like most other Unix systems, set the ctime for inodes on a
2454 * rename.
2456 old_inode->i_ctime = ext4_current_time(old_inode);
2457 ext4_mark_inode_dirty(handle, old_inode);
2460 * ok, that's it
2462 if (le32_to_cpu(old_de->inode) != old_inode->i_ino ||
2463 old_de->name_len != old_dentry->d_name.len ||
2464 strncmp(old_de->name, old_dentry->d_name.name, old_de->name_len) ||
2465 (retval = ext4_delete_entry(handle, old_dir,
2466 old_de, old_bh)) == -ENOENT) {
2467 /* old_de could have moved from under us during htree split, so
2468 * make sure that we are deleting the right entry. We might
2469 * also be pointing to a stale entry in the unused part of
2470 * old_bh so just checking inum and the name isn't enough. */
2471 struct buffer_head *old_bh2;
2472 struct ext4_dir_entry_2 *old_de2;
2474 old_bh2 = ext4_find_entry(old_dir, &old_dentry->d_name, &old_de2);
2475 if (old_bh2) {
2476 retval = ext4_delete_entry(handle, old_dir,
2477 old_de2, old_bh2);
2478 brelse(old_bh2);
2481 if (retval) {
2482 ext4_warning(old_dir->i_sb,
2483 "Deleting old file (%lu), %d, error=%d",
2484 old_dir->i_ino, old_dir->i_nlink, retval);
2487 if (new_inode) {
2488 ext4_dec_count(handle, new_inode);
2489 new_inode->i_ctime = ext4_current_time(new_inode);
2491 old_dir->i_ctime = old_dir->i_mtime = ext4_current_time(old_dir);
2492 ext4_update_dx_flag(old_dir);
2493 if (dir_bh) {
2494 BUFFER_TRACE(dir_bh, "get_write_access");
2495 ext4_journal_get_write_access(handle, dir_bh);
2496 PARENT_INO(dir_bh->b_data, new_dir->i_sb->s_blocksize) =
2497 cpu_to_le32(new_dir->i_ino);
2498 BUFFER_TRACE(dir_bh, "call ext4_handle_dirty_metadata");
2499 ext4_handle_dirty_metadata(handle, old_dir, dir_bh);
2500 ext4_dec_count(handle, old_dir);
2501 if (new_inode) {
2502 /* checked empty_dir above, can't have another parent,
2503 * ext4_dec_count() won't work for many-linked dirs */
2504 new_inode->i_nlink = 0;
2505 } else {
2506 ext4_inc_count(handle, new_dir);
2507 ext4_update_dx_flag(new_dir);
2508 ext4_mark_inode_dirty(handle, new_dir);
2511 ext4_mark_inode_dirty(handle, old_dir);
2512 if (new_inode) {
2513 ext4_mark_inode_dirty(handle, new_inode);
2514 if (!new_inode->i_nlink)
2515 ext4_orphan_add(handle, new_inode);
2516 if (!test_opt(new_dir->i_sb, NO_AUTO_DA_ALLOC))
2517 force_da_alloc = 1;
2519 retval = 0;
2521 end_rename:
2522 brelse(dir_bh);
2523 brelse(old_bh);
2524 brelse(new_bh);
2525 ext4_journal_stop(handle);
2526 if (retval == 0 && force_da_alloc)
2527 ext4_alloc_da_blocks(old_inode);
2528 return retval;
2532 * directories can handle most operations...
2534 const struct inode_operations ext4_dir_inode_operations = {
2535 .create = ext4_create,
2536 .lookup = ext4_lookup,
2537 .link = ext4_link,
2538 .unlink = ext4_unlink,
2539 .symlink = ext4_symlink,
2540 .mkdir = ext4_mkdir,
2541 .rmdir = ext4_rmdir,
2542 .mknod = ext4_mknod,
2543 .rename = ext4_rename,
2544 .setattr = ext4_setattr,
2545 #ifdef CONFIG_EXT4_FS_XATTR
2546 .setxattr = generic_setxattr,
2547 .getxattr = generic_getxattr,
2548 .listxattr = ext4_listxattr,
2549 .removexattr = generic_removexattr,
2550 #endif
2551 .check_acl = ext4_check_acl,
2552 .fiemap = ext4_fiemap,
2555 const struct inode_operations ext4_special_inode_operations = {
2556 .setattr = ext4_setattr,
2557 #ifdef CONFIG_EXT4_FS_XATTR
2558 .setxattr = generic_setxattr,
2559 .getxattr = generic_getxattr,
2560 .listxattr = ext4_listxattr,
2561 .removexattr = generic_removexattr,
2562 #endif
2563 .check_acl = ext4_check_acl,