ext4: Fix BUG_ON at fs/buffer.c:652 in no journal mode
[linux-2.6.git] / fs / ext4 / namei.c
1 /*
2  *  linux/fs/ext4/namei.c
3  *
4  * Copyright (C) 1992, 1993, 1994, 1995
5  * Remy Card (card@masi.ibp.fr)
6  * Laboratoire MASI - Institut Blaise Pascal
7  * Universite Pierre et Marie Curie (Paris VI)
8  *
9  *  from
10  *
11  *  linux/fs/minix/namei.c
12  *
13  *  Copyright (C) 1991, 1992  Linus Torvalds
14  *
15  *  Big-endian to little-endian byte-swapping/bitmaps by
16  *        David S. Miller (davem@caip.rutgers.edu), 1995
17  *  Directory entry file type support and forward compatibility hooks
18  *      for B-tree directories by Theodore Ts'o (tytso@mit.edu), 1998
19  *  Hash Tree Directory indexing (c)
20  *      Daniel Phillips, 2001
21  *  Hash Tree Directory indexing porting
22  *      Christopher Li, 2002
23  *  Hash Tree Directory indexing cleanup
24  *      Theodore Ts'o, 2002
25  */
26
27 #include <linux/fs.h>
28 #include <linux/pagemap.h>
29 #include <linux/jbd2.h>
30 #include <linux/time.h>
31 #include <linux/fcntl.h>
32 #include <linux/stat.h>
33 #include <linux/string.h>
34 #include <linux/quotaops.h>
35 #include <linux/buffer_head.h>
36 #include <linux/bio.h>
37 #include "ext4.h"
38 #include "ext4_jbd2.h"
39
40 #include "xattr.h"
41 #include "acl.h"
42
43 /*
44  * define how far ahead to read directories while searching them.
45  */
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))
50
51 static struct buffer_head *ext4_append(handle_t *handle,
52                                         struct inode *inode,
53                                         ext4_lblk_t *block, int *err)
54 {
55         struct buffer_head *bh;
56
57         *block = inode->i_size >> inode->i_sb->s_blocksize_bits;
58
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;
67                 }
68         }
69         return bh;
70 }
71
72 #ifndef assert
73 #define assert(test) J_ASSERT(test)
74 #endif
75
76 #ifdef DX_DEBUG
77 #define dxtrace(command) command
78 #else
79 #define dxtrace(command)
80 #endif
81
82 struct fake_dirent
83 {
84         __le32 inode;
85         __le16 rec_len;
86         u8 name_len;
87         u8 file_type;
88 };
89
90 struct dx_countlimit
91 {
92         __le16 limit;
93         __le16 count;
94 };
95
96 struct dx_entry
97 {
98         __le32 hash;
99         __le32 block;
100 };
101
102 /*
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.
106  */
107
108 struct dx_root
109 {
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
115         {
116                 __le32 reserved_zero;
117                 u8 hash_version;
118                 u8 info_length; /* 8 */
119                 u8 indirect_levels;
120                 u8 unused_flags;
121         }
122         info;
123         struct dx_entry entries[0];
124 };
125
126 struct dx_node
127 {
128         struct fake_dirent fake;
129         struct dx_entry entries[0];
130 };
131
132
133 struct dx_frame
134 {
135         struct buffer_head *bh;
136         struct dx_entry *entries;
137         struct dx_entry *at;
138 };
139
140 struct dx_map_entry
141 {
142         u32 hash;
143         u16 offs;
144         u16 size;
145 };
146
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);
181
182 unsigned int ext4_rec_len_from_disk(__le16 dlen, unsigned blocksize)
183 {
184         unsigned len = le16_to_cpu(dlen);
185
186         if (len == EXT4_MAX_REC_LEN || len == 0)
187                 return blocksize;
188         return (len & 65532) | ((len & 3) << 16);
189 }
190   
191 __le16 ext4_rec_len_to_disk(unsigned len, unsigned blocksize)
192 {
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);
202         }
203         return cpu_to_le16((len & 65532) | ((len >> 16) & 3));
204 }
205
206 /*
207  * p is at least 6 bytes before the end of page
208  */
209 static inline struct ext4_dir_entry_2 *
210 ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
211 {
212         return (struct ext4_dir_entry_2 *)((char *)p +
213                 ext4_rec_len_from_disk(p->rec_len, blocksize));
214 }
215
216 /*
217  * Future: use high four bits of block for coalesce-on-delete flags
218  * Mask them off for now.
219  */
220
221 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
222 {
223         return le32_to_cpu(entry->block) & 0x00ffffff;
224 }
225
226 static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
227 {
228         entry->block = cpu_to_le32(value);
229 }
230
231 static inline unsigned dx_get_hash(struct dx_entry *entry)
232 {
233         return le32_to_cpu(entry->hash);
234 }
235
236 static inline void dx_set_hash(struct dx_entry *entry, unsigned value)
237 {
238         entry->hash = cpu_to_le32(value);
239 }
240
241 static inline unsigned dx_get_count(struct dx_entry *entries)
242 {
243         return le16_to_cpu(((struct dx_countlimit *) entries)->count);
244 }
245
246 static inline unsigned dx_get_limit(struct dx_entry *entries)
247 {
248         return le16_to_cpu(((struct dx_countlimit *) entries)->limit);
249 }
250
251 static inline void dx_set_count(struct dx_entry *entries, unsigned value)
252 {
253         ((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
254 }
255
256 static inline void dx_set_limit(struct dx_entry *entries, unsigned value)
257 {
258         ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
259 }
260
261 static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
262 {
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);
266 }
267
268 static inline unsigned dx_node_limit(struct inode *dir)
269 {
270         unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);
271         return entry_space / sizeof(struct dx_entry);
272 }
273
274 /*
275  * Debug
276  */
277 #ifdef DX_DEBUG
278 static void dx_show_index(char * label, struct dx_entry *entries)
279 {
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));
285         }
286         printk("\n");
287 }
288
289 struct stats
290 {
291         unsigned names;
292         unsigned space;
293         unsigned bcount;
294 };
295
296 static struct stats dx_show_leaf(struct dx_hash_info *hinfo, struct ext4_dir_entry_2 *de,
297                                  int size, int show_names)
298 {
299         unsigned names = 0, space = 0;
300         char *base = (char *) de;
301         struct dx_hash_info h = *hinfo;
302
303         printk("names: ");
304         while ((char *) de < base + size)
305         {
306                 if (de->inode)
307                 {
308                         if (show_names)
309                         {
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));
316                         }
317                         space += EXT4_DIR_REC_LEN(de->name_len);
318                         names++;
319                 }
320                 de = ext4_next_entry(de, size);
321         }
322         printk("(%i)\n", names);
323         return (struct stats) { names, space, 1 };
324 }
325
326 struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
327                              struct dx_entry *entries, int levels)
328 {
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++)
336         {
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);
350         }
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};
356 }
357 #endif /* DX_DEBUG */
358
359 /*
360  * Probe for a directory leaf block to search.
361  *
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.
367  */
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)
371 {
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;
378
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;
391         }
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;
399
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;
406         }
407
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;
414         }
415
416         entries = (struct dx_entry *) (((char *)&root->info) +
417                                        root->info.info_length);
418
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;
425         }
426
427         dxtrace(printk("Look up %x", hash));
428         while (1)
429         {
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;
437                 }
438
439                 p = entries + 1;
440                 q = entries + count - 1;
441                 while (p <= q)
442                 {
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;
449                 }
450
451                 if (0) // linear search cross check
452                 {
453                         unsigned n = count - 1;
454                         at = entries;
455                         while (n--)
456                         {
457                                 dxtrace(printk(","));
458                                 if (dx_get_hash(++at) > hash)
459                                 {
460                                         at--;
461                                         break;
462                                 }
463                         }
464                         assert (at == p - 1);
465                 }
466
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;
482                 }
483                 frame++;
484                 frame->bh = NULL;
485         }
486 fail2:
487         while (frame >= frame_in) {
488                 brelse(frame->bh);
489                 frame--;
490         }
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;
497 }
498
499 static void dx_release (struct dx_frame *frames)
500 {
501         if (frames[0].bh == NULL)
502                 return;
503
504         if (((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels)
505                 brelse(frames[1].bh);
506         brelse(frames[0].bh);
507 }
508
509 /*
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.
516  *
517  * If the hash value is HASH_NB_ALWAYS, then always go to the next block.
518  *
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.
522  *
523  * If start_hash is non-null, it will be filled in with the starting
524  * hash of the next page.
525  */
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)
530 {
531         struct dx_frame *p;
532         struct buffer_head *bh;
533         int err, num_frames = 0;
534         __u32 bhash;
535
536         p = frame;
537         /*
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.
543          */
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--;
551         }
552
553         /*
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.
559          */
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;
566         }
567         /*
568          * If the hash is HASH_NB_ALWAYS, we always go to the next
569          * block so no check is necessary
570          */
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;
579         }
580         return 1;
581 }
582
583
584 /*
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.
588  */
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)
593 {
594         struct buffer_head *bh;
595         struct ext4_dir_entry_2 *de, *top;
596         int err, count = 0;
597
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;
602
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;
616                 }
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;
628                 }
629                 count++;
630         }
631         brelse(bh);
632         return count;
633 }
634
635
636 /*
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.
640  *
641  * This function returns the number of entries inserted into the tree,
642  * or a negative error code.
643  */
644 int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
645                          __u32 start_minor_hash, __u32 *next_hash)
646 {
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;
655
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_I(dir)->i_flags & EXT4_INDEX_FL)) {
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;
669         }
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;
675
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++;
682         }
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++;
689         }
690
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;
698                 }
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;
707                 }
708                 /*
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
712                  */
713                 if ((ret == 0) ||
714                     (count && ((hashval & 1) == 0)))
715                         break;
716         }
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);
724 }
725
726
727 /*
728  * Directory block splitting, compacting
729  */
730
731 /*
732  * Create map of hash values, offsets, and sizes, stored at end of block.
733  * Returns number of entries mapped.
734  */
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)
738 {
739         int count = 0;
740         char *base = (char *) de;
741         struct dx_hash_info h = *hinfo;
742
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();
752                 }
753                 /* XXX: do we need to check rec_len == 0 case? -Chris */
754                 de = ext4_next_entry(de, blocksize);
755         }
756         return count;
757 }
758
759 /* Sort map by hash value */
760 static void dx_sort_map (struct dx_map_entry *map, unsigned count)
761 {
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);
772         }
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;
782                 }
783         } while(more);
784 }
785
786 static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
787 {
788         struct dx_entry *entries = frame->entries;
789         struct dx_entry *old = frame->at, *new = old + 1;
790         int count = dx_get_count(entries);
791
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);
798 }
799
800 static void ext4_update_dx_flag(struct inode *inode)
801 {
802         if (!EXT4_HAS_COMPAT_FEATURE(inode->i_sb,
803                                      EXT4_FEATURE_COMPAT_DIR_INDEX))
804                 EXT4_I(inode)->i_flags &= ~EXT4_INDEX_FL;
805 }
806
807 /*
808  * NOTE! unlike strncmp, ext4_match returns 1 for success, 0 for failure.
809  *
810  * `len <= EXT4_NAME_LEN' is guaranteed by caller.
811  * `de != NULL' is guaranteed by caller.
812  */
813 static inline int ext4_match (int len, const char * const name,
814                               struct ext4_dir_entry_2 * de)
815 {
816         if (len != de->name_len)
817                 return 0;
818         if (!de->inode)
819                 return 0;
820         return !memcmp(name, de->name, len);
821 }
822
823 /*
824  * Returns 0 if not found, -1 on failure, and 1 on success
825  */
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)
831 {
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;
837
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' */
843
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;
852                 }
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);
860         }
861         return 0;
862 }
863
864
865 /*
866  *      ext4_find_entry()
867  *
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.
872  *
873  * The returned buffer_head has ->b_count elevated.  The caller is expected
874  * to brelse() it when appropriate.
875  */
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)
879 {
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;
892
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);
900                 /*
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.
904                  */
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"));
909         }
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 {
917                 /*
918                  * We deal with the read-ahead logic here.
919                  */
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++) {
925                                 /*
926                                  * Terminate if we reach the end of the
927                                  * directory and must wrap, or if our
928                                  * search has finished at this block.
929                                  */
930                                 if (b >= nblocks || (num && block == start)) {
931                                         bh_use[ra_max] = NULL;
932                                         break;
933                                 }
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);
939                         }
940                 }
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(sb, "reading directory #%lu offset %lu",
947                                    dir->i_ino, (unsigned long)block);
948                         brelse(bh);
949                         goto next;
950                 }
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;
961                 }
962         next:
963                 if (++block >= nblocks)
964                         block = 0;
965         } while (block != start);
966
967         /*
968          * If the directory has grown while we were searching, then
969          * search the last part of the directory before giving up.
970          */
971         block = nblocks;
972         nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
973         if (block < nblocks) {
974                 start = 0;
975                 goto restart;
976         }
977
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;
983 }
984
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)
987 {
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;
998
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 */
1009         }
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);
1021
1022                         if (!ext4_check_dir_entry(__func__, dir, de, bh, off)) {
1023                                 brelse(bh);
1024                                 *err = ERR_BAD_DX_DIR;
1025                                 goto errout;
1026                         }
1027
1028                         if (ext4_match(namelen, name, de)) {
1029                                 *res_dir = de;
1030                                 dx_release(frames);
1031                                 return bh;
1032                         }
1033                 }
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;
1044                 }
1045         } while (retval == 1);
1046
1047         *err = -ENOENT;
1048 errout:
1049         dxtrace(printk(KERN_DEBUG "%s not found\n", name));
1050         dx_release (frames);
1051         return NULL;
1052 }
1053
1054 static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
1055 {
1056         struct inode *inode;
1057         struct ext4_dir_entry_2 *de;
1058         struct buffer_head *bh;
1059
1060         if (dentry->d_name.len > EXT4_NAME_LEN)
1061                 return ERR_PTR(-ENAMETOOLONG);
1062
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(dir->i_sb, "bad inode number: %u", ino);
1070                         return ERR_PTR(-EIO);
1071                 }
1072                 inode = ext4_iget(dir->i_sb, ino);
1073                 if (unlikely(IS_ERR(inode))) {
1074                         if (PTR_ERR(inode) == -ESTALE) {
1075                                 ext4_error(dir->i_sb,
1076                                                 "deleted inode referenced: %u",
1077                                                 ino);
1078                                 return ERR_PTR(-EIO);
1079                         } else {
1080                                 return ERR_CAST(inode);
1081                         }
1082                 }
1083         }
1084         return d_splice_alias(inode, dentry);
1085 }
1086
1087
1088 struct dentry *ext4_get_parent(struct dentry *child)
1089 {
1090         __u32 ino;
1091         struct inode *inode;
1092         static const struct qstr dotdot = {
1093                 .name = "..",
1094                 .len = 2,
1095         };
1096         struct ext4_dir_entry_2 * de;
1097         struct buffer_head *bh;
1098
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);
1105
1106         if (!ext4_valid_inum(child->d_inode->i_sb, ino)) {
1107                 ext4_error(child->d_inode->i_sb,
1108                            "bad inode number: %u", ino);
1109                 return ERR_PTR(-EIO);
1110         }
1111
1112         return d_obtain_alias(ext4_iget(child->d_inode->i_sb, ino));
1113 }
1114
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,
1124 };
1125
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];
1131 }
1132
1133 /*
1134  * Move count entries from end of map between two memory locations.
1135  * Returns pointer to last entry moved.
1136  */
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)
1140 {
1141         unsigned rec_len = 0;
1142
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;
1153         }
1154         return (struct ext4_dir_entry_2 *) (to - rec_len);
1155 }
1156
1157 /*
1158  * Compact each dir entry in the range to the minimal rec_len.
1159  * Returns pointer to last entry in range.
1160  */
1161 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize)
1162 {
1163         struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
1164         unsigned rec_len = 0;
1165
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);
1176                 }
1177                 de = next;
1178         }
1179         return prev;
1180 }
1181
1182 /*
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.
1186  */
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)
1190 {
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;
1201
1202         bh2 = ext4_append (handle, dir, &newblock, &err);
1203         if (!(bh2)) {
1204                 brelse(*bh);
1205                 *bh = NULL;
1206                 goto errout;
1207         }
1208
1209         BUFFER_TRACE(*bh, "get_write_access");
1210         err = ext4_journal_get_write_access(handle, *bh);
1211         if (err)
1212                 goto journal_error;
1213
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;
1218
1219         data2 = bh2->b_data;
1220
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++;
1236         }
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));
1244
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));
1254
1255         /* Which block gets the new entry? */
1256         if (hinfo->hash >= hash2)
1257         {
1258                 swap(*bh, bh2);
1259                 de = de2;
1260         }
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;
1271
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;
1280 }
1281
1282 /*
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.
1289  */
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)
1293 {
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;
1302
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;
1319                 }
1320                 if ((char *) de > top)
1321                         return -ENOSPC;
1322         }
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;
1328         }
1329
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;
1338         }
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);
1347         /*
1348          * XXX shouldn't update any times until successful
1349          * completion of syscall, but too many callers depend
1350          * on this.
1351          *
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.
1357          */
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;
1367 }
1368
1369 /*
1370  * This converts a one block unindexed directory to a 3 block indexed
1371  * directory, and adds the dentry to the indexed directory.
1372  */
1373 static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
1374                             struct inode *inode, struct buffer_head *bh)
1375 {
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;
1391
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;
1399         }
1400         root = (struct dx_root *) bh->b_data;
1401
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(dir->i_sb,
1408                            "invalid rec_len for '..' in inode %lu",
1409                            dir->i_ino);
1410                 brelse(bh);
1411                 return -EIO;
1412         }
1413         len = ((char *) root) + blocksize - (char *) de;
1414
1415         /* Allocate new block for the 0th block's dirents */
1416         bh2 = ext4_append(handle, dir, &block, &retval);
1417         if (!(bh2)) {
1418                 brelse(bh);
1419                 return retval;
1420         }
1421         EXT4_I(dir)->i_flags |= EXT4_INDEX_FL;
1422         data1 = bh2->b_data;
1423
1424         memcpy (data1, de, len);
1425         de = (struct ext4_dir_entry_2 *) data1;
1426         top = data1 + len;
1427         while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
1428                 de = de2;
1429         de->rec_len = ext4_rec_len_to_disk(data1 + blocksize - (char *) de,
1430                                            blocksize);
1431         /* Initialize the root; the dot dirents already exist */
1432         de = (struct ext4_dir_entry_2 *) (&root->dotdot);
1433         de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
1434                                            blocksize);
1435         memset (&root->info, 0, sizeof(root->info));
1436         root->info.info_length = sizeof(root->info);
1437         root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
1438         entries = root->entries;
1439         dx_set_block(entries, 1);
1440         dx_set_count(entries, 1);
1441         dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
1442
1443         /* Initialize as for dx_probe */
1444         hinfo.hash_version = root->info.hash_version;
1445         if (hinfo.hash_version <= DX_HASH_TEA)
1446                 hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
1447         hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
1448         ext4fs_dirhash(name, namelen, &hinfo);
1449         frame = frames;
1450         frame->entries = entries;
1451         frame->at = entries;
1452         frame->bh = bh;
1453         bh = bh2;
1454         de = do_split(handle,dir, &bh, frame, &hinfo, &retval);
1455         dx_release (frames);
1456         if (!(de))
1457                 return retval;
1458
1459         retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
1460         brelse(bh);
1461         return retval;
1462 }
1463
1464 /*
1465  *      ext4_add_entry()
1466  *
1467  * adds a file entry to the specified directory, using the same
1468  * semantics as ext4_find_entry(). It returns NULL if it failed.
1469  *
1470  * NOTE!! The inode part of 'de' is left at 0 - which means you
1471  * may not sleep between calling this and putting something into
1472  * the entry, as someone else might have used it while you slept.
1473  */
1474 static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
1475                           struct inode *inode)
1476 {
1477         struct inode *dir = dentry->d_parent->d_inode;
1478         struct buffer_head *bh;
1479         struct ext4_dir_entry_2 *de;
1480         struct super_block *sb;
1481         int     retval;
1482         int     dx_fallback=0;
1483         unsigned blocksize;
1484         ext4_lblk_t block, blocks;
1485
1486         sb = dir->i_sb;
1487         blocksize = sb->s_blocksize;
1488         if (!dentry->d_name.len)
1489                 return -EINVAL;
1490         if (is_dx(dir)) {
1491                 retval = ext4_dx_add_entry(handle, dentry, inode);
1492                 if (!retval || (retval != ERR_BAD_DX_DIR))
1493                         return retval;
1494                 EXT4_I(dir)->i_flags &= ~EXT4_INDEX_FL;
1495                 dx_fallback++;
1496                 ext4_mark_inode_dirty(handle, dir);
1497         }
1498         blocks = dir->i_size >> sb->s_blocksize_bits;
1499         for (block = 0; block < blocks; block++) {
1500                 bh = ext4_bread(handle, dir, block, 0, &retval);
1501                 if(!bh)
1502                         return retval;
1503                 retval = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
1504                 if (retval != -ENOSPC) {
1505                         brelse(bh);
1506                         return retval;
1507                 }
1508
1509                 if (blocks == 1 && !dx_fallback &&
1510                     EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX))
1511                         return make_indexed_dir(handle, dentry, inode, bh);
1512                 brelse(bh);
1513         }
1514         bh = ext4_append(handle, dir, &block, &retval);
1515         if (!bh)
1516                 return retval;
1517         de = (struct ext4_dir_entry_2 *) bh->b_data;
1518         de->inode = 0;
1519         de->rec_len = ext4_rec_len_to_disk(blocksize, blocksize);
1520         retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
1521         brelse(bh);
1522         return retval;
1523 }
1524
1525 /*
1526  * Returns 0 for success, or a negative error value
1527  */
1528 static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
1529                              struct inode *inode)
1530 {
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;
1539
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;
1545
1546         if (!(bh = ext4_bread(handle,dir, dx_get_block(frame->at), 0, &err)))
1547                 goto cleanup;
1548
1549         BUFFER_TRACE(bh, "get_write_access");
1550         err = ext4_journal_get_write_access(handle, bh);
1551         if (err)
1552                 goto journal_error;
1553
1554         err = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
1555         if (err != -ENOSPC)
1556                 goto cleanup;
1557
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;
1569
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;
1575                 }
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));
1593
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;
1599
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));
1605
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);
1611                         }
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));
1626
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;
1631
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;
1641                 }
1642                 ext4_handle_dirty_metadata(handle, inode, frames[0].bh);
1643         }
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;
1649
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;
1657 }
1658
1659 /*
1660  * ext4_delete_entry deletes a directory entry by merging it with the
1661  * previous entry
1662  */
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)
1667 {
1668         struct ext4_dir_entry_2 *de, *pde;
1669         unsigned int blocksize = dir->i_sb->s_blocksize;
1670         int i;
1671
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;
1694                 }
1695                 i += ext4_rec_len_from_disk(de->rec_len, blocksize);
1696                 pde = de;
1697                 de = ext4_next_entry(de, blocksize);
1698         }
1699         return -ENOENT;
1700 }
1701
1702 /*
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.
1705  */
1706 static void ext4_inc_count(handle_t *handle, struct inode *inode)
1707 {
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);
1715                 }
1716         }
1717 }
1718
1719 /*
1720  * If a directory had nlink == 1, then we should let it be 1. This indicates
1721  * directory has >EXT4_LINK_MAX subdirs.
1722  */
1723 static void ext4_dec_count(handle_t *handle, struct inode *inode)
1724 {
1725         drop_nlink(inode);
1726         if (S_ISDIR(inode->i_mode) && inode->i_nlink == 0)
1727                 inc_nlink(inode);
1728 }
1729
1730
1731 static int ext4_add_nondir(handle_t *handle,
1732                 struct dentry *dentry, struct inode *inode)
1733 {
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;
1740         }
1741         drop_nlink(inode);
1742         unlock_new_inode(inode);
1743         iput(inode);
1744         return err;
1745 }
1746
1747 /*
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.
1751  *
1752  * If the create succeeds, we fill in the inode information
1753  * with d_instantiate().
1754  */
1755 static int ext4_create(struct inode *dir, struct dentry *dentry, int mode,
1756                        struct nameidata *nd)
1757 {
1758         handle_t *handle;
1759         struct inode *inode;
1760         int err, retries = 0;
1761
1762 retry:
1763         handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
1764                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
1765                                         EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
1766         if (IS_ERR(handle))
1767                 return PTR_ERR(handle);
1768
1769         if (IS_DIRSYNC(dir))
1770                 ext4_handle_sync(handle);
1771
1772         inode = ext4_new_inode(handle, dir, mode, &dentry->d_name, 0);
1773         err = PTR_ERR(inode);
1774         if (!IS_ERR(inode)) {
1775                 inode->i_op = &ext4_file_inode_operations;
1776                 inode->i_fop = &ext4_file_operations;
1777                 ext4_set_aops(inode);
1778                 err = ext4_add_nondir(handle, dentry, inode);
1779         }
1780         ext4_journal_stop(handle);
1781         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
1782                 goto retry;
1783         return err;
1784 }
1785
1786 static int ext4_mknod(struct inode *dir, struct dentry *dentry,
1787                       int mode, dev_t rdev)
1788 {
1789         handle_t *handle;
1790         struct inode *inode;
1791         int err, retries = 0;
1792
1793         if (!new_valid_dev(rdev))
1794                 return -EINVAL;
1795
1796 retry:
1797         handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
1798                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
1799                                         EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
1800         if (IS_ERR(handle))
1801                 return PTR_ERR(handle);
1802
1803         if (IS_DIRSYNC(dir))
1804                 ext4_handle_sync(handle);
1805
1806         inode = ext4_new_inode(handle, dir, mode, &dentry->d_name, 0);
1807         err = PTR_ERR(inode);
1808         if (!IS_ERR(inode)) {
1809                 init_special_inode(inode, inode->i_mode, rdev);
1810 #ifdef CONFIG_EXT4_FS_XATTR
1811                 inode->i_op = &ext4_special_inode_operations;
1812 #endif
1813                 err = ext4_add_nondir(handle, dentry, inode);
1814         }
1815         ext4_journal_stop(handle);
1816         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
1817                 goto retry;
1818         return err;
1819 }
1820
1821 static int ext4_mkdir(struct inode *dir, struct dentry *dentry, int mode)
1822 {
1823         handle_t *handle;
1824         struct inode *inode;
1825         struct buffer_head *dir_block;
1826         struct ext4_dir_entry_2 *de;
1827         unsigned int blocksize = dir->i_sb->s_blocksize;
1828         int err, retries = 0;
1829
1830         if (EXT4_DIR_LINK_MAX(dir))
1831                 return -EMLINK;
1832
1833 retry:
1834         handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
1835                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
1836                                         EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
1837         if (IS_ERR(handle))
1838                 return PTR_ERR(handle);
1839
1840         if (IS_DIRSYNC(dir))
1841                 ext4_handle_sync(handle);
1842
1843         inode = ext4_new_inode(handle, dir, S_IFDIR | mode,
1844                                &dentry->d_name, 0);
1845         err = PTR_ERR(inode);
1846         if (IS_ERR(inode))
1847                 goto out_stop;
1848
1849         inode->i_op = &ext4_dir_inode_operations;
1850         inode->i_fop = &ext4_dir_operations;
1851         inode->i_size = EXT4_I(inode)->i_disksize = inode->i_sb->s_blocksize;
1852         dir_block = ext4_bread(handle, inode, 0, 1, &err);
1853         if (!dir_block)
1854                 goto out_clear_inode;
1855         BUFFER_TRACE(dir_block, "get_write_access");
1856         ext4_journal_get_write_access(handle, dir_block);
1857         de = (struct ext4_dir_entry_2 *) dir_block->b_data;
1858         de->inode = cpu_to_le32(inode->i_ino);
1859         de->name_len = 1;
1860         de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
1861                                            blocksize);
1862         strcpy(de->name, ".");
1863         ext4_set_de_type(dir->i_sb, de, S_IFDIR);
1864         de = ext4_next_entry(de, blocksize);
1865         de->inode = cpu_to_le32(dir->i_ino);
1866         de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(1),
1867                                            blocksize);
1868         de->name_len = 2;
1869         strcpy(de->name, "..");
1870         ext4_set_de_type(dir->i_sb, de, S_IFDIR);
1871         inode->i_nlink = 2;
1872         BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
1873         ext4_handle_dirty_metadata(handle, dir, dir_block);
1874         brelse(dir_block);
1875         ext4_mark_inode_dirty(handle, inode);
1876         err = ext4_add_entry(handle, dentry, inode);
1877         if (err) {
1878 out_clear_inode:
1879                 clear_nlink(inode);
1880                 unlock_new_inode(inode);
1881                 ext4_mark_inode_dirty(handle, inode);
1882                 iput(inode);
1883                 goto out_stop;
1884         }
1885         ext4_inc_count(handle, dir);
1886         ext4_update_dx_flag(dir);
1887         ext4_mark_inode_dirty(handle, dir);
1888         d_instantiate(dentry, inode);
1889         unlock_new_inode(inode);
1890 out_stop:
1891         ext4_journal_stop(handle);
1892         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
1893                 goto retry;
1894         return err;
1895 }
1896
1897 /*
1898  * routine to check that the specified directory is empty (for rmdir)
1899  */
1900 static int empty_dir(struct inode *inode)
1901 {
1902         unsigned int offset;
1903         struct buffer_head *bh;
1904         struct ext4_dir_entry_2 *de, *de1;
1905         struct super_block *sb;
1906         int err = 0;
1907
1908         sb = inode->i_sb;
1909         if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2) ||
1910             !(bh = ext4_bread(NULL, inode, 0, 0, &err))) {
1911                 if (err)
1912                         ext4_error(inode->i_sb,
1913                                    "error %d reading directory #%lu offset 0",
1914                                    err, inode->i_ino);
1915                 else
1916                         ext4_warning(inode->i_sb,
1917                                      "bad directory (dir #%lu) - no data block",
1918                                      inode->i_ino);
1919                 return 1;
1920         }
1921         de = (struct ext4_dir_entry_2 *) bh->b_data;
1922         de1 = ext4_next_entry(de, sb->s_blocksize);
1923         if (le32_to_cpu(de->inode) != inode->i_ino ||
1924                         !le32_to_cpu(de1->inode) ||
1925                         strcmp(".", de->name) ||
1926                         strcmp("..", de1->name)) {
1927                 ext4_warning(inode->i_sb,
1928                              "bad directory (dir #%lu) - no `.' or `..'",
1929                              inode->i_ino);
1930                 brelse(bh);
1931                 return 1;
1932         }
1933         offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) +
1934                  ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize);
1935         de = ext4_next_entry(de1, sb->s_blocksize);
1936         while (offset < inode->i_size) {
1937                 if (!bh ||
1938                         (void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
1939                         err = 0;
1940                         brelse(bh);
1941                         bh = ext4_bread(NULL, inode,
1942                                 offset >> EXT4_BLOCK_SIZE_BITS(sb), 0, &err);
1943                         if (!bh) {
1944                                 if (err)
1945                                         ext4_error(sb,
1946                                                    "error %d reading directory"
1947                                                    " #%lu offset %u",
1948                                                    err, inode->i_ino, offset);
1949                                 offset += sb->s_blocksize;
1950                                 continue;
1951                         }
1952                         de = (struct ext4_dir_entry_2 *) bh->b_data;
1953                 }
1954                 if (!ext4_check_dir_entry("empty_dir", inode, de, bh, offset)) {
1955                         de = (struct ext4_dir_entry_2 *)(bh->b_data +
1956                                                          sb->s_blocksize);
1957                         offset = (offset | (sb->s_blocksize - 1)) + 1;
1958                         continue;
1959                 }
1960                 if (le32_to_cpu(de->inode)) {
1961                         brelse(bh);
1962                         return 0;
1963                 }
1964                 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
1965                 de = ext4_next_entry(de, sb->s_blocksize);
1966         }
1967         brelse(bh);
1968         return 1;
1969 }
1970
1971 /* ext4_orphan_add() links an unlinked or truncated inode into a list of
1972  * such inodes, starting at the superblock, in case we crash before the
1973  * file is closed/deleted, or in case the inode truncate spans multiple
1974  * transactions and the last transaction is not recovered after a crash.
1975  *
1976  * At filesystem recovery time, we walk this list deleting unlinked
1977  * inodes and truncating linked inodes in ext4_orphan_cleanup().
1978  */
1979 int ext4_orphan_add(handle_t *handle, struct inode *inode)
1980 {
1981         struct super_block *sb = inode->i_sb;
1982         struct ext4_iloc iloc;
1983         int err = 0, rc;
1984
1985         if (!ext4_handle_valid(handle))
1986                 return 0;
1987
1988         mutex_lock(&EXT4_SB(sb)->s_orphan_lock);
1989         if (!list_empty(&EXT4_I(inode)->i_orphan))
1990                 goto out_unlock;
1991
1992         /* Orphan handling is only valid for files with data blocks
1993          * being truncated, or files being unlinked. */
1994
1995         /* @@@ FIXME: Observation from aviro:
1996          * I think I can trigger J_ASSERT in ext4_orphan_add().  We block
1997          * here (on s_orphan_lock), so race with ext4_link() which might bump
1998          * ->i_nlink. For, say it, character device. Not a regular file,
1999          * not a directory, not a symlink and ->i_nlink > 0.
2000          *
2001          * tytso, 4/25/2009: I'm not sure how that could happen;
2002          * shouldn't the fs core protect us from these sort of
2003          * unlink()/link() races?
2004          */
2005         J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2006                   S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
2007
2008         BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access");
2009         err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
2010         if (err)
2011                 goto out_unlock;
2012
2013         err = ext4_reserve_inode_write(handle, inode, &iloc);
2014         if (err)
2015                 goto out_unlock;
2016
2017         /* Insert this inode at the head of the on-disk orphan list... */
2018         NEXT_ORPHAN(inode) = le32_to_cpu(EXT4_SB(sb)->s_es->s_last_orphan);
2019         EXT4_SB(sb)->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
2020         err = ext4_handle_dirty_metadata(handle, NULL, EXT4_SB(sb)->s_sbh);
2021         rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
2022         if (!err)
2023                 err = rc;
2024
2025         /* Only add to the head of the in-memory list if all the
2026          * previous operations succeeded.  If the orphan_add is going to
2027          * fail (possibly taking the journal offline), we can't risk
2028          * leaving the inode on the orphan list: stray orphan-list
2029          * entries can cause panics at unmount time.
2030          *
2031          * This is safe: on error we're going to ignore the orphan list
2032          * anyway on the next recovery. */
2033         if (!err)
2034                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2035
2036         jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
2037         jbd_debug(4, "orphan inode %lu will point to %d\n",
2038                         inode->i_ino, NEXT_ORPHAN(inode));
2039 out_unlock:
2040         mutex_unlock(&EXT4_SB(sb)->s_orphan_lock);
2041         ext4_std_error(inode->i_sb, err);
2042         return err;
2043 }
2044
2045 /*
2046  * ext4_orphan_del() removes an unlinked or truncated inode from the list
2047  * of such inodes stored on disk, because it is finally being cleaned up.
2048  */
2049 int ext4_orphan_del(handle_t *handle, struct inode *inode)
2050 {
2051         struct list_head *prev;
2052         struct ext4_inode_info *ei = EXT4_I(inode);
2053         struct ext4_sb_info *sbi;
2054         __u32 ino_next;
2055         struct ext4_iloc iloc;
2056         int err = 0;
2057
2058         /* ext4_handle_valid() assumes a valid handle_t pointer */
2059         if (handle && !ext4_handle_valid(handle))
2060                 return 0;
2061
2062         mutex_lock(&EXT4_SB(inode->i_sb)->s_orphan_lock);
2063         if (list_empty(&ei->i_orphan))
2064                 goto out;
2065
2066         ino_next = NEXT_ORPHAN(inode);
2067         prev = ei->i_orphan.prev;
2068         sbi = EXT4_SB(inode->i_sb);
2069
2070         jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
2071
2072         list_del_init(&ei->i_orphan);
2073
2074         /* If we're on an error path, we may not have a valid
2075          * transaction handle with which to update the orphan list on
2076          * disk, but we still need to remove the inode from the linked
2077          * list in memory. */
2078         if (sbi->s_journal && !handle)
2079                 goto out;
2080
2081         err = ext4_reserve_inode_write(handle, inode, &iloc);
2082         if (err)
2083                 goto out_err;
2084
2085         if (prev == &sbi->s_orphan) {
2086                 jbd_debug(4, "superblock will point to %u\n", ino_next);
2087                 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2088                 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2089                 if (err)
2090                         goto out_brelse;
2091                 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
2092                 err = ext4_handle_dirty_metadata(handle, NULL, sbi->s_sbh);
2093         } else {
2094                 struct ext4_iloc iloc2;
2095                 struct inode *i_prev =
2096                         &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
2097
2098                 jbd_debug(4, "orphan inode %lu will point to %u\n",
2099                           i_prev->i_ino, ino_next);
2100                 err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
2101                 if (err)
2102                         goto out_brelse;
2103                 NEXT_ORPHAN(i_prev) = ino_next;
2104                 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
2105         }
2106         if (err)
2107                 goto out_brelse;
2108         NEXT_ORPHAN(inode) = 0;
2109         err = ext4_mark_iloc_dirty(handle, inode, &iloc);
2110
2111 out_err:
2112         ext4_std_error(inode->i_sb, err);
2113 out:
2114         mutex_unlock(&EXT4_SB(inode->i_sb)->s_orphan_lock);
2115         return err;
2116
2117 out_brelse:
2118         brelse(iloc.bh);
2119         goto out_err;
2120 }
2121
2122 static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
2123 {
2124         int retval;
2125         struct inode *inode;
2126         struct buffer_head *bh;
2127         struct ext4_dir_entry_2 *de;
2128         handle_t *handle;
2129
2130         /* Initialize quotas before so that eventual writes go in
2131          * separate transaction */
2132         vfs_dq_init(dentry->d_inode);
2133         handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb));
2134         if (IS_ERR(handle))
2135                 return PTR_ERR(handle);
2136
2137         retval = -ENOENT;
2138         bh = ext4_find_entry(dir, &dentry->d_name, &de);
2139         if (!bh)
2140                 goto end_rmdir;
2141
2142         if (IS_DIRSYNC(dir))
2143                 ext4_handle_sync(handle);
2144
2145         inode = dentry->d_inode;
2146
2147         retval = -EIO;
2148         if (le32_to_cpu(de->inode) != inode->i_ino)
2149                 goto end_rmdir;
2150
2151         retval = -ENOTEMPTY;
2152         if (!empty_dir(inode))
2153                 goto end_rmdir;
2154
2155         retval = ext4_delete_entry(handle, dir, de, bh);
2156         if (retval)
2157                 goto end_rmdir;
2158         if (!EXT4_DIR_LINK_EMPTY(inode))
2159                 ext4_warning(inode->i_sb,
2160                              "empty directory has too many links (%d)",
2161                              inode->i_nlink);
2162         inode->i_version++;
2163         clear_nlink(inode);
2164         /* There's no need to set i_disksize: the fact that i_nlink is
2165          * zero will ensure that the right thing happens during any
2166          * recovery. */
2167         inode->i_size = 0;
2168         ext4_orphan_add(handle, inode);
2169         inode->i_ctime = dir->i_ctime = dir->i_mtime = ext4_current_time(inode);
2170         ext4_mark_inode_dirty(handle, inode);
2171         ext4_dec_count(handle, dir);
2172         ext4_update_dx_flag(dir);
2173         ext4_mark_inode_dirty(handle, dir);
2174
2175 end_rmdir:
2176         ext4_journal_stop(handle);
2177         brelse(bh);
2178         return retval;
2179 }
2180
2181 static int ext4_unlink(struct inode *dir, struct dentry *dentry)
2182 {
2183         int retval;
2184         struct inode *inode;
2185         struct buffer_head *bh;
2186         struct ext4_dir_entry_2 *de;
2187         handle_t *handle;
2188
2189         /* Initialize quotas before so that eventual writes go
2190          * in separate transaction */
2191         vfs_dq_init(dentry->d_inode);
2192         handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb));
2193         if (IS_ERR(handle))
2194                 return PTR_ERR(handle);
2195
2196         if (IS_DIRSYNC(dir))
2197                 ext4_handle_sync(handle);
2198
2199         retval = -ENOENT;
2200         bh = ext4_find_entry(dir, &dentry->d_name, &de);
2201         if (!bh)
2202                 goto end_unlink;
2203
2204         inode = dentry->d_inode;
2205
2206         retval = -EIO;
2207         if (le32_to_cpu(de->inode) != inode->i_ino)
2208                 goto end_unlink;
2209
2210         if (!inode->i_nlink) {
2211                 ext4_warning(inode->i_sb,
2212                              "Deleting nonexistent file (%lu), %d",
2213                              inode->i_ino, inode->i_nlink);
2214                 inode->i_nlink = 1;
2215         }
2216         retval = ext4_delete_entry(handle, dir, de, bh);
2217         if (retval)
2218                 goto end_unlink;
2219         dir->i_ctime = dir->i_mtime = ext4_current_time(dir);
2220         ext4_update_dx_flag(dir);
2221         ext4_mark_inode_dirty(handle, dir);
2222         drop_nlink(inode);
2223         if (!inode->i_nlink)
2224                 ext4_orphan_add(handle, inode);
2225         inode->i_ctime = ext4_current_time(inode);
2226         ext4_mark_inode_dirty(handle, inode);
2227         retval = 0;
2228
2229 end_unlink:
2230         ext4_journal_stop(handle);
2231         brelse(bh);
2232         return retval;
2233 }
2234
2235 static int ext4_symlink(struct inode *dir,
2236                         struct dentry *dentry, const char *symname)
2237 {
2238         handle_t *handle;
2239         struct inode *inode;
2240         int l, err, retries = 0;
2241
2242         l = strlen(symname)+1;
2243         if (l > dir->i_sb->s_blocksize)
2244                 return -ENAMETOOLONG;
2245
2246 retry:
2247         handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2248                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS + 5 +
2249                                         EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
2250         if (IS_ERR(handle))
2251                 return PTR_ERR(handle);
2252
2253         if (IS_DIRSYNC(dir))
2254                 ext4_handle_sync(handle);
2255
2256         inode = ext4_new_inode(handle, dir, S_IFLNK|S_IRWXUGO,
2257                                &dentry->d_name, 0);
2258         err = PTR_ERR(inode);
2259         if (IS_ERR(inode))
2260                 goto out_stop;
2261
2262         if (l > sizeof(EXT4_I(inode)->i_data)) {
2263                 inode->i_op = &ext4_symlink_inode_operations;
2264                 ext4_set_aops(inode);
2265                 /*
2266                  * page_symlink() calls into ext4_prepare/commit_write.
2267                  * We have a transaction open.  All is sweetness.  It also sets
2268                  * i_size in generic_commit_write().
2269                  */
2270                 err = __page_symlink(inode, symname, l, 1);
2271                 if (err) {
2272                         clear_nlink(inode);
2273                         unlock_new_inode(inode);
2274                         ext4_mark_inode_dirty(handle, inode);
2275                         iput(inode);
2276                         goto out_stop;
2277                 }
2278         } else {
2279                 /* clear the extent format for fast symlink */
2280                 EXT4_I(inode)->i_flags &= ~EXT4_EXTENTS_FL;
2281                 inode->i_op = &ext4_fast_symlink_inode_operations;
2282                 memcpy((char *)&EXT4_I(inode)->i_data, symname, l);
2283                 inode->i_size = l-1;
2284         }
2285         EXT4_I(inode)->i_disksize = inode->i_size;
2286         err = ext4_add_nondir(handle, dentry, inode);
2287 out_stop:
2288         ext4_journal_stop(handle);
2289         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2290                 goto retry;
2291         return err;
2292 }
2293
2294 static int ext4_link(struct dentry *old_dentry,
2295                      struct inode *dir, struct dentry *dentry)
2296 {
2297         handle_t *handle;
2298         struct inode *inode = old_dentry->d_inode;
2299         int err, retries = 0;
2300
2301         if (inode->i_nlink >= EXT4_LINK_MAX)
2302                 return -EMLINK;
2303
2304         /*
2305          * Return -ENOENT if we've raced with unlink and i_nlink is 0.  Doing
2306          * otherwise has the potential to corrupt the orphan inode list.
2307          */
2308         if (inode->i_nlink == 0)
2309                 return -ENOENT;
2310
2311 retry:
2312         handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2313                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS);
2314         if (IS_ERR(handle))
2315                 return PTR_ERR(handle);
2316
2317         if (IS_DIRSYNC(dir))
2318                 ext4_handle_sync(handle);
2319
2320         inode->i_ctime = ext4_current_time(inode);
2321         ext4_inc_count(handle, inode);
2322         atomic_inc(&inode->i_count);
2323
2324         err = ext4_add_entry(handle, dentry, inode);
2325         if (!err) {
2326                 ext4_mark_inode_dirty(handle, inode);
2327                 d_instantiate(dentry, inode);
2328         } else {
2329                 drop_nlink(inode);
2330                 iput(inode);
2331         }
2332         ext4_journal_stop(handle);
2333         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2334                 goto retry;
2335         return err;
2336 }
2337
2338 #define PARENT_INO(buffer, size) \
2339         (ext4_next_entry((struct ext4_dir_entry_2 *)(buffer), size)->inode)
2340
2341 /*
2342  * Anybody can rename anything with this: the permission checks are left to the
2343  * higher-level routines.
2344  */
2345 static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
2346                        struct inode *new_dir, struct dentry *new_dentry)
2347 {
2348         handle_t *handle;
2349         struct inode *old_inode, *new_inode;
2350         struct buffer_head *old_bh, *new_bh, *dir_bh;
2351         struct ext4_dir_entry_2 *old_de, *new_de;
2352         int retval, force_da_alloc = 0;
2353
2354         old_bh = new_bh = dir_bh = NULL;
2355
2356         /* Initialize quotas before so that eventual writes go
2357          * in separate transaction */
2358         if (new_dentry->d_inode)
2359                 vfs_dq_init(new_dentry->d_inode);
2360         handle = ext4_journal_start(old_dir, 2 *
2361                                         EXT4_DATA_TRANS_BLOCKS(old_dir->i_sb) +
2362                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
2363         if (IS_ERR(handle))
2364                 return PTR_ERR(handle);
2365
2366         if (IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir))
2367                 ext4_handle_sync(handle);
2368
2369         old_bh = ext4_find_entry(old_dir, &old_dentry->d_name, &old_de);
2370         /*
2371          *  Check for inode number is _not_ due to possible IO errors.
2372          *  We might rmdir the source, keep it as pwd of some process
2373          *  and merrily kill the link to whatever was created under the
2374          *  same name. Goodbye sticky bit ;-<
2375          */
2376         old_inode = old_dentry->d_inode;
2377         retval = -ENOENT;
2378         if (!old_bh || le32_to_cpu(old_de->inode) != old_inode->i_ino)
2379                 goto end_rename;
2380
2381         new_inode = new_dentry->d_inode;
2382         new_bh = ext4_find_entry(new_dir, &new_dentry->d_name, &new_de);
2383         if (new_bh) {
2384                 if (!new_inode) {
2385                         brelse(new_bh);
2386                         new_bh = NULL;
2387                 }
2388         }
2389         if (S_ISDIR(old_inode->i_mode)) {
2390                 if (new_inode) {
2391                         retval = -ENOTEMPTY;
2392                         if (!empty_dir(new_inode))
2393                                 goto end_rename;
2394                 }
2395                 retval = -EIO;
2396                 dir_bh = ext4_bread(handle, old_inode, 0, 0, &retval);
2397                 if (!dir_bh)
2398                         goto end_rename;
2399                 if (le32_to_cpu(PARENT_INO(dir_bh->b_data,
2400                                 old_dir->i_sb->s_blocksize)) != old_dir->i_ino)
2401                         goto end_rename;
2402                 retval = -EMLINK;
2403                 if (!new_inode && new_dir != old_dir &&
2404                     EXT4_DIR_LINK_MAX(new_dir))
2405                         goto end_rename;
2406         }
2407         if (!new_bh) {
2408                 retval = ext4_add_entry(handle, new_dentry, old_inode);
2409                 if (retval)
2410                         goto end_rename;
2411         } else {
2412                 BUFFER_TRACE(new_bh, "get write access");
2413                 ext4_journal_get_write_access(handle, new_bh);
2414                 new_de->inode = cpu_to_le32(old_inode->i_ino);
2415                 if (EXT4_HAS_INCOMPAT_FEATURE(new_dir->i_sb,
2416                                               EXT4_FEATURE_INCOMPAT_FILETYPE))
2417                         new_de->file_type = old_de->file_type;
2418                 new_dir->i_version++;
2419                 new_dir->i_ctime = new_dir->i_mtime =
2420                                         ext4_current_time(new_dir);
2421                 ext4_mark_inode_dirty(handle, new_dir);
2422                 BUFFER_TRACE(new_bh, "call ext4_handle_dirty_metadata");
2423                 ext4_handle_dirty_metadata(handle, new_dir, new_bh);
2424                 brelse(new_bh);
2425                 new_bh = NULL;
2426         }
2427
2428         /*
2429          * Like most other Unix systems, set the ctime for inodes on a
2430          * rename.
2431          */
2432         old_inode->i_ctime = ext4_current_time(old_inode);
2433         ext4_mark_inode_dirty(handle, old_inode);
2434
2435         /*
2436          * ok, that's it
2437          */
2438         if (le32_to_cpu(old_de->inode) != old_inode->i_ino ||
2439             old_de->name_len != old_dentry->d_name.len ||
2440             strncmp(old_de->name, old_dentry->d_name.name, old_de->name_len) ||
2441             (retval = ext4_delete_entry(handle, old_dir,
2442                                         old_de, old_bh)) == -ENOENT) {
2443                 /* old_de could have moved from under us during htree split, so
2444                  * make sure that we are deleting the right entry.  We might
2445                  * also be pointing to a stale entry in the unused part of
2446                  * old_bh so just checking inum and the name isn't enough. */
2447                 struct buffer_head *old_bh2;
2448                 struct ext4_dir_entry_2 *old_de2;
2449
2450                 old_bh2 = ext4_find_entry(old_dir, &old_dentry->d_name, &old_de2);
2451                 if (old_bh2) {
2452                         retval = ext4_delete_entry(handle, old_dir,
2453                                                    old_de2, old_bh2);
2454                         brelse(old_bh2);
2455                 }
2456         }
2457         if (retval) {
2458                 ext4_warning(old_dir->i_sb,
2459                                 "Deleting old file (%lu), %d, error=%d",
2460                                 old_dir->i_ino, old_dir->i_nlink, retval);
2461         }
2462
2463         if (new_inode) {
2464                 ext4_dec_count(handle, new_inode);
2465                 new_inode->i_ctime = ext4_current_time(new_inode);
2466         }
2467         old_dir->i_ctime = old_dir->i_mtime = ext4_current_time(old_dir);
2468         ext4_update_dx_flag(old_dir);
2469         if (dir_bh) {
2470                 BUFFER_TRACE(dir_bh, "get_write_access");
2471                 ext4_journal_get_write_access(handle, dir_bh);
2472                 PARENT_INO(dir_bh->b_data, new_dir->i_sb->s_blocksize) =
2473                                                 cpu_to_le32(new_dir->i_ino);
2474                 BUFFER_TRACE(dir_bh, "call ext4_handle_dirty_metadata");
2475                 ext4_handle_dirty_metadata(handle, old_dir, dir_bh);
2476                 ext4_dec_count(handle, old_dir);
2477                 if (new_inode) {
2478                         /* checked empty_dir above, can't have another parent,
2479                          * ext4_dec_count() won't work for many-linked dirs */
2480                         new_inode->i_nlink = 0;
2481                 } else {
2482                         ext4_inc_count(handle, new_dir);
2483                         ext4_update_dx_flag(new_dir);
2484                         ext4_mark_inode_dirty(handle, new_dir);
2485                 }
2486         }
2487         ext4_mark_inode_dirty(handle, old_dir);
2488         if (new_inode) {
2489                 ext4_mark_inode_dirty(handle, new_inode);
2490                 if (!new_inode->i_nlink)
2491                         ext4_orphan_add(handle, new_inode);
2492                 if (!test_opt(new_dir->i_sb, NO_AUTO_DA_ALLOC))
2493                         force_da_alloc = 1;
2494         }
2495         retval = 0;
2496
2497 end_rename:
2498         brelse(dir_bh);
2499         brelse(old_bh);
2500         brelse(new_bh);
2501         ext4_journal_stop(handle);
2502         if (retval == 0 && force_da_alloc)
2503                 ext4_alloc_da_blocks(old_inode);
2504         return retval;
2505 }
2506
2507 /*
2508  * directories can handle most operations...
2509  */
2510 const struct inode_operations ext4_dir_inode_operations = {
2511         .create         = ext4_create,
2512         .lookup         = ext4_lookup,
2513         .link           = ext4_link,
2514         .unlink         = ext4_unlink,
2515         .symlink        = ext4_symlink,
2516         .mkdir          = ext4_mkdir,
2517         .rmdir          = ext4_rmdir,
2518         .mknod          = ext4_mknod,
2519         .rename         = ext4_rename,
2520         .setattr        = ext4_setattr,
2521 #ifdef CONFIG_EXT4_FS_XATTR
2522         .setxattr       = generic_setxattr,
2523         .getxattr       = generic_getxattr,
2524         .listxattr      = ext4_listxattr,
2525         .removexattr    = generic_removexattr,
2526 #endif
2527         .check_acl      = ext4_check_acl,
2528         .fiemap         = ext4_fiemap,
2529 };
2530
2531 const struct inode_operations ext4_special_inode_operations = {
2532         .setattr        = ext4_setattr,
2533 #ifdef CONFIG_EXT4_FS_XATTR
2534         .setxattr       = generic_setxattr,
2535         .getxattr       = generic_getxattr,
2536         .listxattr      = ext4_listxattr,
2537         .removexattr    = generic_removexattr,
2538 #endif
2539         .check_acl      = ext4_check_acl,
2540 };