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[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, __func__,
387                              "Unrecognised inode hash code %d",
388                              root->info.hash_version);
389                 brelse(bh);
390                 *err = ERR_BAD_DX_DIR;
391                 goto fail;
392         }
393         hinfo->hash_version = root->info.hash_version;
394         if (hinfo->hash_version <= DX_HASH_TEA)
395                 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
396         hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
397         if (d_name)
398                 ext4fs_dirhash(d_name->name, d_name->len, hinfo);
399         hash = hinfo->hash;
400
401         if (root->info.unused_flags & 1) {
402                 ext4_warning(dir->i_sb, __func__,
403                              "Unimplemented inode hash flags: %#06x",
404                              root->info.unused_flags);
405                 brelse(bh);
406                 *err = ERR_BAD_DX_DIR;
407                 goto fail;
408         }
409
410         if ((indirect = root->info.indirect_levels) > 1) {
411                 ext4_warning(dir->i_sb, __func__,
412                              "Unimplemented inode hash depth: %#06x",
413                              root->info.indirect_levels);
414                 brelse(bh);
415                 *err = ERR_BAD_DX_DIR;
416                 goto fail;
417         }
418
419         entries = (struct dx_entry *) (((char *)&root->info) +
420                                        root->info.info_length);
421
422         if (dx_get_limit(entries) != dx_root_limit(dir,
423                                                    root->info.info_length)) {
424                 ext4_warning(dir->i_sb, __func__,
425                              "dx entry: limit != root limit");
426                 brelse(bh);
427                 *err = ERR_BAD_DX_DIR;
428                 goto fail;
429         }
430
431         dxtrace(printk("Look up %x", hash));
432         while (1)
433         {
434                 count = dx_get_count(entries);
435                 if (!count || count > dx_get_limit(entries)) {
436                         ext4_warning(dir->i_sb, __func__,
437                                      "dx entry: no count or count > limit");
438                         brelse(bh);
439                         *err = ERR_BAD_DX_DIR;
440                         goto fail2;
441                 }
442
443                 p = entries + 1;
444                 q = entries + count - 1;
445                 while (p <= q)
446                 {
447                         m = p + (q - p)/2;
448                         dxtrace(printk("."));
449                         if (dx_get_hash(m) > hash)
450                                 q = m - 1;
451                         else
452                                 p = m + 1;
453                 }
454
455                 if (0) // linear search cross check
456                 {
457                         unsigned n = count - 1;
458                         at = entries;
459                         while (n--)
460                         {
461                                 dxtrace(printk(","));
462                                 if (dx_get_hash(++at) > hash)
463                                 {
464                                         at--;
465                                         break;
466                                 }
467                         }
468                         assert (at == p - 1);
469                 }
470
471                 at = p - 1;
472                 dxtrace(printk(" %x->%u\n", at == entries? 0: dx_get_hash(at), dx_get_block(at)));
473                 frame->bh = bh;
474                 frame->entries = entries;
475                 frame->at = at;
476                 if (!indirect--) return frame;
477                 if (!(bh = ext4_bread (NULL,dir, dx_get_block(at), 0, err)))
478                         goto fail2;
479                 at = entries = ((struct dx_node *) bh->b_data)->entries;
480                 if (dx_get_limit(entries) != dx_node_limit (dir)) {
481                         ext4_warning(dir->i_sb, __func__,
482                                      "dx entry: limit != node limit");
483                         brelse(bh);
484                         *err = ERR_BAD_DX_DIR;
485                         goto fail2;
486                 }
487                 frame++;
488                 frame->bh = NULL;
489         }
490 fail2:
491         while (frame >= frame_in) {
492                 brelse(frame->bh);
493                 frame--;
494         }
495 fail:
496         if (*err == ERR_BAD_DX_DIR)
497                 ext4_warning(dir->i_sb, __func__,
498                              "Corrupt dir inode %ld, running e2fsck is "
499                              "recommended.", dir->i_ino);
500         return NULL;
501 }
502
503 static void dx_release (struct dx_frame *frames)
504 {
505         if (frames[0].bh == NULL)
506                 return;
507
508         if (((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels)
509                 brelse(frames[1].bh);
510         brelse(frames[0].bh);
511 }
512
513 /*
514  * This function increments the frame pointer to search the next leaf
515  * block, and reads in the necessary intervening nodes if the search
516  * should be necessary.  Whether or not the search is necessary is
517  * controlled by the hash parameter.  If the hash value is even, then
518  * the search is only continued if the next block starts with that
519  * hash value.  This is used if we are searching for a specific file.
520  *
521  * If the hash value is HASH_NB_ALWAYS, then always go to the next block.
522  *
523  * This function returns 1 if the caller should continue to search,
524  * or 0 if it should not.  If there is an error reading one of the
525  * index blocks, it will a negative error code.
526  *
527  * If start_hash is non-null, it will be filled in with the starting
528  * hash of the next page.
529  */
530 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
531                                  struct dx_frame *frame,
532                                  struct dx_frame *frames,
533                                  __u32 *start_hash)
534 {
535         struct dx_frame *p;
536         struct buffer_head *bh;
537         int err, num_frames = 0;
538         __u32 bhash;
539
540         p = frame;
541         /*
542          * Find the next leaf page by incrementing the frame pointer.
543          * If we run out of entries in the interior node, loop around and
544          * increment pointer in the parent node.  When we break out of
545          * this loop, num_frames indicates the number of interior
546          * nodes need to be read.
547          */
548         while (1) {
549                 if (++(p->at) < p->entries + dx_get_count(p->entries))
550                         break;
551                 if (p == frames)
552                         return 0;
553                 num_frames++;
554                 p--;
555         }
556
557         /*
558          * If the hash is 1, then continue only if the next page has a
559          * continuation hash of any value.  This is used for readdir
560          * handling.  Otherwise, check to see if the hash matches the
561          * desired contiuation hash.  If it doesn't, return since
562          * there's no point to read in the successive index pages.
563          */
564         bhash = dx_get_hash(p->at);
565         if (start_hash)
566                 *start_hash = bhash;
567         if ((hash & 1) == 0) {
568                 if ((bhash & ~1) != hash)
569                         return 0;
570         }
571         /*
572          * If the hash is HASH_NB_ALWAYS, we always go to the next
573          * block so no check is necessary
574          */
575         while (num_frames--) {
576                 if (!(bh = ext4_bread(NULL, dir, dx_get_block(p->at),
577                                       0, &err)))
578                         return err; /* Failure */
579                 p++;
580                 brelse(p->bh);
581                 p->bh = bh;
582                 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
583         }
584         return 1;
585 }
586
587
588 /*
589  * This function fills a red-black tree with information from a
590  * directory block.  It returns the number directory entries loaded
591  * into the tree.  If there is an error it is returned in err.
592  */
593 static int htree_dirblock_to_tree(struct file *dir_file,
594                                   struct inode *dir, ext4_lblk_t block,
595                                   struct dx_hash_info *hinfo,
596                                   __u32 start_hash, __u32 start_minor_hash)
597 {
598         struct buffer_head *bh;
599         struct ext4_dir_entry_2 *de, *top;
600         int err, count = 0;
601
602         dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
603                                                         (unsigned long)block));
604         if (!(bh = ext4_bread (NULL, dir, block, 0, &err)))
605                 return err;
606
607         de = (struct ext4_dir_entry_2 *) bh->b_data;
608         top = (struct ext4_dir_entry_2 *) ((char *) de +
609                                            dir->i_sb->s_blocksize -
610                                            EXT4_DIR_REC_LEN(0));
611         for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) {
612                 if (!ext4_check_dir_entry("htree_dirblock_to_tree", dir, de, bh,
613                                         (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
614                                                 +((char *)de - bh->b_data))) {
615                         /* On error, skip the f_pos to the next block. */
616                         dir_file->f_pos = (dir_file->f_pos |
617                                         (dir->i_sb->s_blocksize - 1)) + 1;
618                         brelse(bh);
619                         return count;
620                 }
621                 ext4fs_dirhash(de->name, de->name_len, hinfo);
622                 if ((hinfo->hash < start_hash) ||
623                     ((hinfo->hash == start_hash) &&
624                      (hinfo->minor_hash < start_minor_hash)))
625                         continue;
626                 if (de->inode == 0)
627                         continue;
628                 if ((err = ext4_htree_store_dirent(dir_file,
629                                    hinfo->hash, hinfo->minor_hash, de)) != 0) {
630                         brelse(bh);
631                         return err;
632                 }
633                 count++;
634         }
635         brelse(bh);
636         return count;
637 }
638
639
640 /*
641  * This function fills a red-black tree with information from a
642  * directory.  We start scanning the directory in hash order, starting
643  * at start_hash and start_minor_hash.
644  *
645  * This function returns the number of entries inserted into the tree,
646  * or a negative error code.
647  */
648 int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
649                          __u32 start_minor_hash, __u32 *next_hash)
650 {
651         struct dx_hash_info hinfo;
652         struct ext4_dir_entry_2 *de;
653         struct dx_frame frames[2], *frame;
654         struct inode *dir;
655         ext4_lblk_t block;
656         int count = 0;
657         int ret, err;
658         __u32 hashval;
659
660         dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n", 
661                        start_hash, start_minor_hash));
662         dir = dir_file->f_path.dentry->d_inode;
663         if (!(EXT4_I(dir)->i_flags & EXT4_INDEX_FL)) {
664                 hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
665                 if (hinfo.hash_version <= DX_HASH_TEA)
666                         hinfo.hash_version +=
667                                 EXT4_SB(dir->i_sb)->s_hash_unsigned;
668                 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
669                 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
670                                                start_hash, start_minor_hash);
671                 *next_hash = ~0;
672                 return count;
673         }
674         hinfo.hash = start_hash;
675         hinfo.minor_hash = 0;
676         frame = dx_probe(NULL, dir, &hinfo, frames, &err);
677         if (!frame)
678                 return err;
679
680         /* Add '.' and '..' from the htree header */
681         if (!start_hash && !start_minor_hash) {
682                 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
683                 if ((err = ext4_htree_store_dirent(dir_file, 0, 0, de)) != 0)
684                         goto errout;
685                 count++;
686         }
687         if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
688                 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
689                 de = ext4_next_entry(de, dir->i_sb->s_blocksize);
690                 if ((err = ext4_htree_store_dirent(dir_file, 2, 0, de)) != 0)
691                         goto errout;
692                 count++;
693         }
694
695         while (1) {
696                 block = dx_get_block(frame->at);
697                 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
698                                              start_hash, start_minor_hash);
699                 if (ret < 0) {
700                         err = ret;
701                         goto errout;
702                 }
703                 count += ret;
704                 hashval = ~0;
705                 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
706                                             frame, frames, &hashval);
707                 *next_hash = hashval;
708                 if (ret < 0) {
709                         err = ret;
710                         goto errout;
711                 }
712                 /*
713                  * Stop if:  (a) there are no more entries, or
714                  * (b) we have inserted at least one entry and the
715                  * next hash value is not a continuation
716                  */
717                 if ((ret == 0) ||
718                     (count && ((hashval & 1) == 0)))
719                         break;
720         }
721         dx_release(frames);
722         dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, "
723                        "next hash: %x\n", count, *next_hash));
724         return count;
725 errout:
726         dx_release(frames);
727         return (err);
728 }
729
730
731 /*
732  * Directory block splitting, compacting
733  */
734
735 /*
736  * Create map of hash values, offsets, and sizes, stored at end of block.
737  * Returns number of entries mapped.
738  */
739 static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize,
740                        struct dx_hash_info *hinfo,
741                        struct dx_map_entry *map_tail)
742 {
743         int count = 0;
744         char *base = (char *) de;
745         struct dx_hash_info h = *hinfo;
746
747         while ((char *) de < base + blocksize) {
748                 if (de->name_len && de->inode) {
749                         ext4fs_dirhash(de->name, de->name_len, &h);
750                         map_tail--;
751                         map_tail->hash = h.hash;
752                         map_tail->offs = ((char *) de - base)>>2;
753                         map_tail->size = le16_to_cpu(de->rec_len);
754                         count++;
755                         cond_resched();
756                 }
757                 /* XXX: do we need to check rec_len == 0 case? -Chris */
758                 de = ext4_next_entry(de, blocksize);
759         }
760         return count;
761 }
762
763 /* Sort map by hash value */
764 static void dx_sort_map (struct dx_map_entry *map, unsigned count)
765 {
766         struct dx_map_entry *p, *q, *top = map + count - 1;
767         int more;
768         /* Combsort until bubble sort doesn't suck */
769         while (count > 2) {
770                 count = count*10/13;
771                 if (count - 9 < 2) /* 9, 10 -> 11 */
772                         count = 11;
773                 for (p = top, q = p - count; q >= map; p--, q--)
774                         if (p->hash < q->hash)
775                                 swap(*p, *q);
776         }
777         /* Garden variety bubble sort */
778         do {
779                 more = 0;
780                 q = top;
781                 while (q-- > map) {
782                         if (q[1].hash >= q[0].hash)
783                                 continue;
784                         swap(*(q+1), *q);
785                         more = 1;
786                 }
787         } while(more);
788 }
789
790 static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
791 {
792         struct dx_entry *entries = frame->entries;
793         struct dx_entry *old = frame->at, *new = old + 1;
794         int count = dx_get_count(entries);
795
796         assert(count < dx_get_limit(entries));
797         assert(old < entries + count);
798         memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
799         dx_set_hash(new, hash);
800         dx_set_block(new, block);
801         dx_set_count(entries, count + 1);
802 }
803
804 static void ext4_update_dx_flag(struct inode *inode)
805 {
806         if (!EXT4_HAS_COMPAT_FEATURE(inode->i_sb,
807                                      EXT4_FEATURE_COMPAT_DIR_INDEX))
808                 EXT4_I(inode)->i_flags &= ~EXT4_INDEX_FL;
809 }
810
811 /*
812  * NOTE! unlike strncmp, ext4_match returns 1 for success, 0 for failure.
813  *
814  * `len <= EXT4_NAME_LEN' is guaranteed by caller.
815  * `de != NULL' is guaranteed by caller.
816  */
817 static inline int ext4_match (int len, const char * const name,
818                               struct ext4_dir_entry_2 * de)
819 {
820         if (len != de->name_len)
821                 return 0;
822         if (!de->inode)
823                 return 0;
824         return !memcmp(name, de->name, len);
825 }
826
827 /*
828  * Returns 0 if not found, -1 on failure, and 1 on success
829  */
830 static inline int search_dirblock(struct buffer_head *bh,
831                                   struct inode *dir,
832                                   const struct qstr *d_name,
833                                   unsigned int offset,
834                                   struct ext4_dir_entry_2 ** res_dir)
835 {
836         struct ext4_dir_entry_2 * de;
837         char * dlimit;
838         int de_len;
839         const char *name = d_name->name;
840         int namelen = d_name->len;
841
842         de = (struct ext4_dir_entry_2 *) bh->b_data;
843         dlimit = bh->b_data + dir->i_sb->s_blocksize;
844         while ((char *) de < dlimit) {
845                 /* this code is executed quadratically often */
846                 /* do minimal checking `by hand' */
847
848                 if ((char *) de + namelen <= dlimit &&
849                     ext4_match (namelen, name, de)) {
850                         /* found a match - just to be sure, do a full check */
851                         if (!ext4_check_dir_entry("ext4_find_entry",
852                                                   dir, de, bh, offset))
853                                 return -1;
854                         *res_dir = de;
855                         return 1;
856                 }
857                 /* prevent looping on a bad block */
858                 de_len = ext4_rec_len_from_disk(de->rec_len,
859                                                 dir->i_sb->s_blocksize);
860                 if (de_len <= 0)
861                         return -1;
862                 offset += de_len;
863                 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
864         }
865         return 0;
866 }
867
868
869 /*
870  *      ext4_find_entry()
871  *
872  * finds an entry in the specified directory with the wanted name. It
873  * returns the cache buffer in which the entry was found, and the entry
874  * itself (as a parameter - res_dir). It does NOT read the inode of the
875  * entry - you'll have to do that yourself if you want to.
876  *
877  * The returned buffer_head has ->b_count elevated.  The caller is expected
878  * to brelse() it when appropriate.
879  */
880 static struct buffer_head * ext4_find_entry (struct inode *dir,
881                                         const struct qstr *d_name,
882                                         struct ext4_dir_entry_2 ** res_dir)
883 {
884         struct super_block *sb;
885         struct buffer_head *bh_use[NAMEI_RA_SIZE];
886         struct buffer_head *bh, *ret = NULL;
887         ext4_lblk_t start, block, b;
888         int ra_max = 0;         /* Number of bh's in the readahead
889                                    buffer, bh_use[] */
890         int ra_ptr = 0;         /* Current index into readahead
891                                    buffer */
892         int num = 0;
893         ext4_lblk_t  nblocks;
894         int i, err;
895         int namelen;
896
897         *res_dir = NULL;
898         sb = dir->i_sb;
899         namelen = d_name->len;
900         if (namelen > EXT4_NAME_LEN)
901                 return NULL;
902         if (is_dx(dir)) {
903                 bh = ext4_dx_find_entry(dir, d_name, res_dir, &err);
904                 /*
905                  * On success, or if the error was file not found,
906                  * return.  Otherwise, fall back to doing a search the
907                  * old fashioned way.
908                  */
909                 if (bh || (err != ERR_BAD_DX_DIR))
910                         return bh;
911                 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
912                                "falling back\n"));
913         }
914         nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
915         start = EXT4_I(dir)->i_dir_start_lookup;
916         if (start >= nblocks)
917                 start = 0;
918         block = start;
919 restart:
920         do {
921                 /*
922                  * We deal with the read-ahead logic here.
923                  */
924                 if (ra_ptr >= ra_max) {
925                         /* Refill the readahead buffer */
926                         ra_ptr = 0;
927                         b = block;
928                         for (ra_max = 0; ra_max < NAMEI_RA_SIZE; ra_max++) {
929                                 /*
930                                  * Terminate if we reach the end of the
931                                  * directory and must wrap, or if our
932                                  * search has finished at this block.
933                                  */
934                                 if (b >= nblocks || (num && block == start)) {
935                                         bh_use[ra_max] = NULL;
936                                         break;
937                                 }
938                                 num++;
939                                 bh = ext4_getblk(NULL, dir, b++, 0, &err);
940                                 bh_use[ra_max] = bh;
941                                 if (bh)
942                                         ll_rw_block(READ_META, 1, &bh);
943                         }
944                 }
945                 if ((bh = bh_use[ra_ptr++]) == NULL)
946                         goto next;
947                 wait_on_buffer(bh);
948                 if (!buffer_uptodate(bh)) {
949                         /* read error, skip block & hope for the best */
950                         ext4_error(sb, __func__, "reading directory #%lu "
951                                    "offset %lu", dir->i_ino,
952                                    (unsigned long)block);
953                         brelse(bh);
954                         goto next;
955                 }
956                 i = search_dirblock(bh, dir, d_name,
957                             block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
958                 if (i == 1) {
959                         EXT4_I(dir)->i_dir_start_lookup = block;
960                         ret = bh;
961                         goto cleanup_and_exit;
962                 } else {
963                         brelse(bh);
964                         if (i < 0)
965                                 goto cleanup_and_exit;
966                 }
967         next:
968                 if (++block >= nblocks)
969                         block = 0;
970         } while (block != start);
971
972         /*
973          * If the directory has grown while we were searching, then
974          * search the last part of the directory before giving up.
975          */
976         block = nblocks;
977         nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
978         if (block < nblocks) {
979                 start = 0;
980                 goto restart;
981         }
982
983 cleanup_and_exit:
984         /* Clean up the read-ahead blocks */
985         for (; ra_ptr < ra_max; ra_ptr++)
986                 brelse(bh_use[ra_ptr]);
987         return ret;
988 }
989
990 static struct buffer_head * ext4_dx_find_entry(struct inode *dir, const struct qstr *d_name,
991                        struct ext4_dir_entry_2 **res_dir, int *err)
992 {
993         struct super_block * sb;
994         struct dx_hash_info     hinfo;
995         u32 hash;
996         struct dx_frame frames[2], *frame;
997         struct ext4_dir_entry_2 *de, *top;
998         struct buffer_head *bh;
999         ext4_lblk_t block;
1000         int retval;
1001         int namelen = d_name->len;
1002         const u8 *name = d_name->name;
1003
1004         sb = dir->i_sb;
1005         /* NFS may look up ".." - look at dx_root directory block */
1006         if (namelen > 2 || name[0] != '.'||(name[1] != '.' && name[1] != '\0')){
1007                 if (!(frame = dx_probe(d_name, dir, &hinfo, frames, err)))
1008                         return NULL;
1009         } else {
1010                 frame = frames;
1011                 frame->bh = NULL;                       /* for dx_release() */
1012                 frame->at = (struct dx_entry *)frames;  /* hack for zero entry*/
1013                 dx_set_block(frame->at, 0);             /* dx_root block is 0 */
1014         }
1015         hash = hinfo.hash;
1016         do {
1017                 block = dx_get_block(frame->at);
1018                 if (!(bh = ext4_bread (NULL,dir, block, 0, err)))
1019                         goto errout;
1020                 de = (struct ext4_dir_entry_2 *) bh->b_data;
1021                 top = (struct ext4_dir_entry_2 *) ((char *) de + sb->s_blocksize -
1022                                        EXT4_DIR_REC_LEN(0));
1023                 for (; de < top; de = ext4_next_entry(de, sb->s_blocksize)) {
1024                         int off = (block << EXT4_BLOCK_SIZE_BITS(sb))
1025                                   + ((char *) de - bh->b_data);
1026
1027                         if (!ext4_check_dir_entry(__func__, dir, de, bh, off)) {
1028                                 brelse(bh);
1029                                 *err = ERR_BAD_DX_DIR;
1030                                 goto errout;
1031                         }
1032
1033                         if (ext4_match(namelen, name, de)) {
1034                                 *res_dir = de;
1035                                 dx_release(frames);
1036                                 return bh;
1037                         }
1038                 }
1039                 brelse(bh);
1040                 /* Check to see if we should continue to search */
1041                 retval = ext4_htree_next_block(dir, hash, frame,
1042                                                frames, NULL);
1043                 if (retval < 0) {
1044                         ext4_warning(sb, __func__,
1045                              "error reading index page in directory #%lu",
1046                              dir->i_ino);
1047                         *err = retval;
1048                         goto errout;
1049                 }
1050         } while (retval == 1);
1051
1052         *err = -ENOENT;
1053 errout:
1054         dxtrace(printk(KERN_DEBUG "%s not found\n", name));
1055         dx_release (frames);
1056         return NULL;
1057 }
1058
1059 static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
1060 {
1061         struct inode *inode;
1062         struct ext4_dir_entry_2 *de;
1063         struct buffer_head *bh;
1064
1065         if (dentry->d_name.len > EXT4_NAME_LEN)
1066                 return ERR_PTR(-ENAMETOOLONG);
1067
1068         bh = ext4_find_entry(dir, &dentry->d_name, &de);
1069         inode = NULL;
1070         if (bh) {
1071                 __u32 ino = le32_to_cpu(de->inode);
1072                 brelse(bh);
1073                 if (!ext4_valid_inum(dir->i_sb, ino)) {
1074                         ext4_error(dir->i_sb, "ext4_lookup",
1075                                    "bad inode number: %u", ino);
1076                         return ERR_PTR(-EIO);
1077                 }
1078                 inode = ext4_iget(dir->i_sb, ino);
1079                 if (unlikely(IS_ERR(inode))) {
1080                         if (PTR_ERR(inode) == -ESTALE) {
1081                                 ext4_error(dir->i_sb, __func__,
1082                                                 "deleted inode referenced: %u",
1083                                                 ino);
1084                                 return ERR_PTR(-EIO);
1085                         } else {
1086                                 return ERR_CAST(inode);
1087                         }
1088                 }
1089         }
1090         return d_splice_alias(inode, dentry);
1091 }
1092
1093
1094 struct dentry *ext4_get_parent(struct dentry *child)
1095 {
1096         __u32 ino;
1097         struct inode *inode;
1098         static const struct qstr dotdot = {
1099                 .name = "..",
1100                 .len = 2,
1101         };
1102         struct ext4_dir_entry_2 * de;
1103         struct buffer_head *bh;
1104
1105         bh = ext4_find_entry(child->d_inode, &dotdot, &de);
1106         inode = NULL;
1107         if (!bh)
1108                 return ERR_PTR(-ENOENT);
1109         ino = le32_to_cpu(de->inode);
1110         brelse(bh);
1111
1112         if (!ext4_valid_inum(child->d_inode->i_sb, ino)) {
1113                 ext4_error(child->d_inode->i_sb, "ext4_get_parent",
1114                            "bad inode number: %u", ino);
1115                 return ERR_PTR(-EIO);
1116         }
1117
1118         return d_obtain_alias(ext4_iget(child->d_inode->i_sb, ino));
1119 }
1120
1121 #define S_SHIFT 12
1122 static unsigned char ext4_type_by_mode[S_IFMT >> S_SHIFT] = {
1123         [S_IFREG >> S_SHIFT]    = EXT4_FT_REG_FILE,
1124         [S_IFDIR >> S_SHIFT]    = EXT4_FT_DIR,
1125         [S_IFCHR >> S_SHIFT]    = EXT4_FT_CHRDEV,
1126         [S_IFBLK >> S_SHIFT]    = EXT4_FT_BLKDEV,
1127         [S_IFIFO >> S_SHIFT]    = EXT4_FT_FIFO,
1128         [S_IFSOCK >> S_SHIFT]   = EXT4_FT_SOCK,
1129         [S_IFLNK >> S_SHIFT]    = EXT4_FT_SYMLINK,
1130 };
1131
1132 static inline void ext4_set_de_type(struct super_block *sb,
1133                                 struct ext4_dir_entry_2 *de,
1134                                 umode_t mode) {
1135         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE))
1136                 de->file_type = ext4_type_by_mode[(mode & S_IFMT)>>S_SHIFT];
1137 }
1138
1139 /*
1140  * Move count entries from end of map between two memory locations.
1141  * Returns pointer to last entry moved.
1142  */
1143 static struct ext4_dir_entry_2 *
1144 dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count,
1145                 unsigned blocksize)
1146 {
1147         unsigned rec_len = 0;
1148
1149         while (count--) {
1150                 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *) 
1151                                                 (from + (map->offs<<2));
1152                 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1153                 memcpy (to, de, rec_len);
1154                 ((struct ext4_dir_entry_2 *) to)->rec_len =
1155                                 ext4_rec_len_to_disk(rec_len, blocksize);
1156                 de->inode = 0;
1157                 map++;
1158                 to += rec_len;
1159         }
1160         return (struct ext4_dir_entry_2 *) (to - rec_len);
1161 }
1162
1163 /*
1164  * Compact each dir entry in the range to the minimal rec_len.
1165  * Returns pointer to last entry in range.
1166  */
1167 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize)
1168 {
1169         struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
1170         unsigned rec_len = 0;
1171
1172         prev = to = de;
1173         while ((char*)de < base + blocksize) {
1174                 next = ext4_next_entry(de, blocksize);
1175                 if (de->inode && de->name_len) {
1176                         rec_len = EXT4_DIR_REC_LEN(de->name_len);
1177                         if (de > to)
1178                                 memmove(to, de, rec_len);
1179                         to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
1180                         prev = to;
1181                         to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
1182                 }
1183                 de = next;
1184         }
1185         return prev;
1186 }
1187
1188 /*
1189  * Split a full leaf block to make room for a new dir entry.
1190  * Allocate a new block, and move entries so that they are approx. equally full.
1191  * Returns pointer to de in block into which the new entry will be inserted.
1192  */
1193 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
1194                         struct buffer_head **bh,struct dx_frame *frame,
1195                         struct dx_hash_info *hinfo, int *error)
1196 {
1197         unsigned blocksize = dir->i_sb->s_blocksize;
1198         unsigned count, continued;
1199         struct buffer_head *bh2;
1200         ext4_lblk_t newblock;
1201         u32 hash2;
1202         struct dx_map_entry *map;
1203         char *data1 = (*bh)->b_data, *data2;
1204         unsigned split, move, size;
1205         struct ext4_dir_entry_2 *de = NULL, *de2;
1206         int     err = 0, i;
1207
1208         bh2 = ext4_append (handle, dir, &newblock, &err);
1209         if (!(bh2)) {
1210                 brelse(*bh);
1211                 *bh = NULL;
1212                 goto errout;
1213         }
1214
1215         BUFFER_TRACE(*bh, "get_write_access");
1216         err = ext4_journal_get_write_access(handle, *bh);
1217         if (err)
1218                 goto journal_error;
1219
1220         BUFFER_TRACE(frame->bh, "get_write_access");
1221         err = ext4_journal_get_write_access(handle, frame->bh);
1222         if (err)
1223                 goto journal_error;
1224
1225         data2 = bh2->b_data;
1226
1227         /* create map in the end of data2 block */
1228         map = (struct dx_map_entry *) (data2 + blocksize);
1229         count = dx_make_map((struct ext4_dir_entry_2 *) data1,
1230                              blocksize, hinfo, map);
1231         map -= count;
1232         dx_sort_map(map, count);
1233         /* Split the existing block in the middle, size-wise */
1234         size = 0;
1235         move = 0;
1236         for (i = count-1; i >= 0; i--) {
1237                 /* is more than half of this entry in 2nd half of the block? */
1238                 if (size + map[i].size/2 > blocksize/2)
1239                         break;
1240                 size += map[i].size;
1241                 move++;
1242         }
1243         /* map index at which we will split */
1244         split = count - move;
1245         hash2 = map[split].hash;
1246         continued = hash2 == map[split - 1].hash;
1247         dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
1248                         (unsigned long)dx_get_block(frame->at),
1249                                         hash2, split, count-split));
1250
1251         /* Fancy dance to stay within two buffers */
1252         de2 = dx_move_dirents(data1, data2, map + split, count - split, blocksize);
1253         de = dx_pack_dirents(data1, blocksize);
1254         de->rec_len = ext4_rec_len_to_disk(data1 + blocksize - (char *) de,
1255                                            blocksize);
1256         de2->rec_len = ext4_rec_len_to_disk(data2 + blocksize - (char *) de2,
1257                                             blocksize);
1258         dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data1, blocksize, 1));
1259         dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data2, blocksize, 1));
1260
1261         /* Which block gets the new entry? */
1262         if (hinfo->hash >= hash2)
1263         {
1264                 swap(*bh, bh2);
1265                 de = de2;
1266         }
1267         dx_insert_block(frame, hash2 + continued, newblock);
1268         err = ext4_handle_dirty_metadata(handle, dir, bh2);
1269         if (err)
1270                 goto journal_error;
1271         err = ext4_handle_dirty_metadata(handle, dir, frame->bh);
1272         if (err)
1273                 goto journal_error;
1274         brelse(bh2);
1275         dxtrace(dx_show_index("frame", frame->entries));
1276         return de;
1277
1278 journal_error:
1279         brelse(*bh);
1280         brelse(bh2);
1281         *bh = NULL;
1282         ext4_std_error(dir->i_sb, err);
1283 errout:
1284         *error = err;
1285         return NULL;
1286 }
1287
1288 /*
1289  * Add a new entry into a directory (leaf) block.  If de is non-NULL,
1290  * it points to a directory entry which is guaranteed to be large
1291  * enough for new directory entry.  If de is NULL, then
1292  * add_dirent_to_buf will attempt search the directory block for
1293  * space.  It will return -ENOSPC if no space is available, and -EIO
1294  * and -EEXIST if directory entry already exists.
1295  *
1296  * NOTE!  bh is NOT released in the case where ENOSPC is returned.  In
1297  * all other cases bh is released.
1298  */
1299 static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
1300                              struct inode *inode, struct ext4_dir_entry_2 *de,
1301                              struct buffer_head *bh)
1302 {
1303         struct inode    *dir = dentry->d_parent->d_inode;
1304         const char      *name = dentry->d_name.name;
1305         int             namelen = dentry->d_name.len;
1306         unsigned int    offset = 0;
1307         unsigned int    blocksize = dir->i_sb->s_blocksize;
1308         unsigned short  reclen;
1309         int             nlen, rlen, err;
1310         char            *top;
1311
1312         reclen = EXT4_DIR_REC_LEN(namelen);
1313         if (!de) {
1314                 de = (struct ext4_dir_entry_2 *)bh->b_data;
1315                 top = bh->b_data + blocksize - reclen;
1316                 while ((char *) de <= top) {
1317                         if (!ext4_check_dir_entry("ext4_add_entry", dir, de,
1318                                                   bh, offset)) {
1319                                 brelse(bh);
1320                                 return -EIO;
1321                         }
1322                         if (ext4_match(namelen, name, de)) {
1323                                 brelse(bh);
1324                                 return -EEXIST;
1325                         }
1326                         nlen = EXT4_DIR_REC_LEN(de->name_len);
1327                         rlen = ext4_rec_len_from_disk(de->rec_len, blocksize);
1328                         if ((de->inode? rlen - nlen: rlen) >= reclen)
1329                                 break;
1330                         de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
1331                         offset += rlen;
1332                 }
1333                 if ((char *) de > top)
1334                         return -ENOSPC;
1335         }
1336         BUFFER_TRACE(bh, "get_write_access");
1337         err = ext4_journal_get_write_access(handle, bh);
1338         if (err) {
1339                 ext4_std_error(dir->i_sb, err);
1340                 brelse(bh);
1341                 return err;
1342         }
1343
1344         /* By now the buffer is marked for journaling */
1345         nlen = EXT4_DIR_REC_LEN(de->name_len);
1346         rlen = ext4_rec_len_from_disk(de->rec_len, blocksize);
1347         if (de->inode) {
1348                 struct ext4_dir_entry_2 *de1 = (struct ext4_dir_entry_2 *)((char *)de + nlen);
1349                 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, blocksize);
1350                 de->rec_len = ext4_rec_len_to_disk(nlen, blocksize);
1351                 de = de1;
1352         }
1353         de->file_type = EXT4_FT_UNKNOWN;
1354         if (inode) {
1355                 de->inode = cpu_to_le32(inode->i_ino);
1356                 ext4_set_de_type(dir->i_sb, de, inode->i_mode);
1357         } else
1358                 de->inode = 0;
1359         de->name_len = namelen;
1360         memcpy(de->name, name, namelen);
1361         /*
1362          * XXX shouldn't update any times until successful
1363          * completion of syscall, but too many callers depend
1364          * on this.
1365          *
1366          * XXX similarly, too many callers depend on
1367          * ext4_new_inode() setting the times, but error
1368          * recovery deletes the inode, so the worst that can
1369          * happen is that the times are slightly out of date
1370          * and/or different from the directory change time.
1371          */
1372         dir->i_mtime = dir->i_ctime = ext4_current_time(dir);
1373         ext4_update_dx_flag(dir);
1374         dir->i_version++;
1375         ext4_mark_inode_dirty(handle, dir);
1376         BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1377         err = ext4_handle_dirty_metadata(handle, dir, bh);
1378         if (err)
1379                 ext4_std_error(dir->i_sb, err);
1380         brelse(bh);
1381         return 0;
1382 }
1383
1384 /*
1385  * This converts a one block unindexed directory to a 3 block indexed
1386  * directory, and adds the dentry to the indexed directory.
1387  */
1388 static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
1389                             struct inode *inode, struct buffer_head *bh)
1390 {
1391         struct inode    *dir = dentry->d_parent->d_inode;
1392         const char      *name = dentry->d_name.name;
1393         int             namelen = dentry->d_name.len;
1394         struct buffer_head *bh2;
1395         struct dx_root  *root;
1396         struct dx_frame frames[2], *frame;
1397         struct dx_entry *entries;
1398         struct ext4_dir_entry_2 *de, *de2;
1399         char            *data1, *top;
1400         unsigned        len;
1401         int             retval;
1402         unsigned        blocksize;
1403         struct dx_hash_info hinfo;
1404         ext4_lblk_t  block;
1405         struct fake_dirent *fde;
1406
1407         blocksize =  dir->i_sb->s_blocksize;
1408         dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
1409         retval = ext4_journal_get_write_access(handle, bh);
1410         if (retval) {
1411                 ext4_std_error(dir->i_sb, retval);
1412                 brelse(bh);
1413                 return retval;
1414         }
1415         root = (struct dx_root *) bh->b_data;
1416
1417         /* The 0th block becomes the root, move the dirents out */
1418         fde = &root->dotdot;
1419         de = (struct ext4_dir_entry_2 *)((char *)fde +
1420                 ext4_rec_len_from_disk(fde->rec_len, blocksize));
1421         if ((char *) de >= (((char *) root) + blocksize)) {
1422                 ext4_error(dir->i_sb, __func__,
1423                            "invalid rec_len for '..' in inode %lu",
1424                            dir->i_ino);
1425                 brelse(bh);
1426                 return -EIO;
1427         }
1428         len = ((char *) root) + blocksize - (char *) de;
1429
1430         /* Allocate new block for the 0th block's dirents */
1431         bh2 = ext4_append(handle, dir, &block, &retval);
1432         if (!(bh2)) {
1433                 brelse(bh);
1434                 return retval;
1435         }
1436         EXT4_I(dir)->i_flags |= EXT4_INDEX_FL;
1437         data1 = bh2->b_data;
1438
1439         memcpy (data1, de, len);
1440         de = (struct ext4_dir_entry_2 *) data1;
1441         top = data1 + len;
1442         while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
1443                 de = de2;
1444         de->rec_len = ext4_rec_len_to_disk(data1 + blocksize - (char *) de,
1445                                            blocksize);
1446         /* Initialize the root; the dot dirents already exist */
1447         de = (struct ext4_dir_entry_2 *) (&root->dotdot);
1448         de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
1449                                            blocksize);
1450         memset (&root->info, 0, sizeof(root->info));
1451         root->info.info_length = sizeof(root->info);
1452         root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
1453         entries = root->entries;
1454         dx_set_block(entries, 1);
1455         dx_set_count(entries, 1);
1456         dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
1457
1458         /* Initialize as for dx_probe */
1459         hinfo.hash_version = root->info.hash_version;
1460         if (hinfo.hash_version <= DX_HASH_TEA)
1461                 hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
1462         hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
1463         ext4fs_dirhash(name, namelen, &hinfo);
1464         frame = frames;
1465         frame->entries = entries;
1466         frame->at = entries;
1467         frame->bh = bh;
1468         bh = bh2;
1469         de = do_split(handle,dir, &bh, frame, &hinfo, &retval);
1470         dx_release (frames);
1471         if (!(de))
1472                 return retval;
1473
1474         return add_dirent_to_buf(handle, dentry, inode, de, bh);
1475 }
1476
1477 /*
1478  *      ext4_add_entry()
1479  *
1480  * adds a file entry to the specified directory, using the same
1481  * semantics as ext4_find_entry(). It returns NULL if it failed.
1482  *
1483  * NOTE!! The inode part of 'de' is left at 0 - which means you
1484  * may not sleep between calling this and putting something into
1485  * the entry, as someone else might have used it while you slept.
1486  */
1487 static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
1488                           struct inode *inode)
1489 {
1490         struct inode *dir = dentry->d_parent->d_inode;
1491         struct buffer_head *bh;
1492         struct ext4_dir_entry_2 *de;
1493         struct super_block *sb;
1494         int     retval;
1495         int     dx_fallback=0;
1496         unsigned blocksize;
1497         ext4_lblk_t block, blocks;
1498
1499         sb = dir->i_sb;
1500         blocksize = sb->s_blocksize;
1501         if (!dentry->d_name.len)
1502                 return -EINVAL;
1503         if (is_dx(dir)) {
1504                 retval = ext4_dx_add_entry(handle, dentry, inode);
1505                 if (!retval || (retval != ERR_BAD_DX_DIR))
1506                         return retval;
1507                 EXT4_I(dir)->i_flags &= ~EXT4_INDEX_FL;
1508                 dx_fallback++;
1509                 ext4_mark_inode_dirty(handle, dir);
1510         }
1511         blocks = dir->i_size >> sb->s_blocksize_bits;
1512         for (block = 0; block < blocks; block++) {
1513                 bh = ext4_bread(handle, dir, block, 0, &retval);
1514                 if(!bh)
1515                         return retval;
1516                 retval = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
1517                 if (retval != -ENOSPC)
1518                         return retval;
1519
1520                 if (blocks == 1 && !dx_fallback &&
1521                     EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX))
1522                         return make_indexed_dir(handle, dentry, inode, bh);
1523                 brelse(bh);
1524         }
1525         bh = ext4_append(handle, dir, &block, &retval);
1526         if (!bh)
1527                 return retval;
1528         de = (struct ext4_dir_entry_2 *) bh->b_data;
1529         de->inode = 0;
1530         de->rec_len = ext4_rec_len_to_disk(blocksize, blocksize);
1531         return add_dirent_to_buf(handle, dentry, inode, de, bh);
1532 }
1533
1534 /*
1535  * Returns 0 for success, or a negative error value
1536  */
1537 static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
1538                              struct inode *inode)
1539 {
1540         struct dx_frame frames[2], *frame;
1541         struct dx_entry *entries, *at;
1542         struct dx_hash_info hinfo;
1543         struct buffer_head *bh;
1544         struct inode *dir = dentry->d_parent->d_inode;
1545         struct super_block *sb = dir->i_sb;
1546         struct ext4_dir_entry_2 *de;
1547         int err;
1548
1549         frame = dx_probe(&dentry->d_name, dir, &hinfo, frames, &err);
1550         if (!frame)
1551                 return err;
1552         entries = frame->entries;
1553         at = frame->at;
1554
1555         if (!(bh = ext4_bread(handle,dir, dx_get_block(frame->at), 0, &err)))
1556                 goto cleanup;
1557
1558         BUFFER_TRACE(bh, "get_write_access");
1559         err = ext4_journal_get_write_access(handle, bh);
1560         if (err)
1561                 goto journal_error;
1562
1563         err = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
1564         if (err != -ENOSPC) {
1565                 bh = NULL;
1566                 goto cleanup;
1567         }
1568
1569         /* Block full, should compress but for now just split */
1570         dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
1571                        dx_get_count(entries), dx_get_limit(entries)));
1572         /* Need to split index? */
1573         if (dx_get_count(entries) == dx_get_limit(entries)) {
1574                 ext4_lblk_t newblock;
1575                 unsigned icount = dx_get_count(entries);
1576                 int levels = frame - frames;
1577                 struct dx_entry *entries2;
1578                 struct dx_node *node2;
1579                 struct buffer_head *bh2;
1580
1581                 if (levels && (dx_get_count(frames->entries) ==
1582                                dx_get_limit(frames->entries))) {
1583                         ext4_warning(sb, __func__,
1584                                      "Directory index full!");
1585                         err = -ENOSPC;
1586                         goto cleanup;
1587                 }
1588                 bh2 = ext4_append (handle, dir, &newblock, &err);
1589                 if (!(bh2))
1590                         goto cleanup;
1591                 node2 = (struct dx_node *)(bh2->b_data);
1592                 entries2 = node2->entries;
1593                 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
1594                                                            sb->s_blocksize);
1595                 node2->fake.inode = 0;
1596                 BUFFER_TRACE(frame->bh, "get_write_access");
1597                 err = ext4_journal_get_write_access(handle, frame->bh);
1598                 if (err)
1599                         goto journal_error;
1600                 if (levels) {
1601                         unsigned icount1 = icount/2, icount2 = icount - icount1;
1602                         unsigned hash2 = dx_get_hash(entries + icount1);
1603                         dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
1604                                        icount1, icount2));
1605
1606                         BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
1607                         err = ext4_journal_get_write_access(handle,
1608                                                              frames[0].bh);
1609                         if (err)
1610                                 goto journal_error;
1611
1612                         memcpy((char *) entries2, (char *) (entries + icount1),
1613                                icount2 * sizeof(struct dx_entry));
1614                         dx_set_count(entries, icount1);
1615                         dx_set_count(entries2, icount2);
1616                         dx_set_limit(entries2, dx_node_limit(dir));
1617
1618                         /* Which index block gets the new entry? */
1619                         if (at - entries >= icount1) {
1620                                 frame->at = at = at - entries - icount1 + entries2;
1621                                 frame->entries = entries = entries2;
1622                                 swap(frame->bh, bh2);
1623                         }
1624                         dx_insert_block(frames + 0, hash2, newblock);
1625                         dxtrace(dx_show_index("node", frames[1].entries));
1626                         dxtrace(dx_show_index("node",
1627                                ((struct dx_node *) bh2->b_data)->entries));
1628                         err = ext4_handle_dirty_metadata(handle, inode, bh2);
1629                         if (err)
1630                                 goto journal_error;
1631                         brelse (bh2);
1632                 } else {
1633                         dxtrace(printk(KERN_DEBUG
1634                                        "Creating second level index...\n"));
1635                         memcpy((char *) entries2, (char *) entries,
1636                                icount * sizeof(struct dx_entry));
1637                         dx_set_limit(entries2, dx_node_limit(dir));
1638
1639                         /* Set up root */
1640                         dx_set_count(entries, 1);
1641                         dx_set_block(entries + 0, newblock);
1642                         ((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels = 1;
1643
1644                         /* Add new access path frame */
1645                         frame = frames + 1;
1646                         frame->at = at = at - entries + entries2;
1647                         frame->entries = entries = entries2;
1648                         frame->bh = bh2;
1649                         err = ext4_journal_get_write_access(handle,
1650                                                              frame->bh);
1651                         if (err)
1652                                 goto journal_error;
1653                 }
1654                 ext4_handle_dirty_metadata(handle, inode, frames[0].bh);
1655         }
1656         de = do_split(handle, dir, &bh, frame, &hinfo, &err);
1657         if (!de)
1658                 goto cleanup;
1659         err = add_dirent_to_buf(handle, dentry, inode, de, bh);
1660         bh = NULL;
1661         goto cleanup;
1662
1663 journal_error:
1664         ext4_std_error(dir->i_sb, err);
1665 cleanup:
1666         if (bh)
1667                 brelse(bh);
1668         dx_release(frames);
1669         return err;
1670 }
1671
1672 /*
1673  * ext4_delete_entry deletes a directory entry by merging it with the
1674  * previous entry
1675  */
1676 static int ext4_delete_entry(handle_t *handle,
1677                              struct inode *dir,
1678                              struct ext4_dir_entry_2 *de_del,
1679                              struct buffer_head *bh)
1680 {
1681         struct ext4_dir_entry_2 *de, *pde;
1682         unsigned int blocksize = dir->i_sb->s_blocksize;
1683         int i;
1684
1685         i = 0;
1686         pde = NULL;
1687         de = (struct ext4_dir_entry_2 *) bh->b_data;
1688         while (i < bh->b_size) {
1689                 if (!ext4_check_dir_entry("ext4_delete_entry", dir, de, bh, i))
1690                         return -EIO;
1691                 if (de == de_del)  {
1692                         BUFFER_TRACE(bh, "get_write_access");
1693                         ext4_journal_get_write_access(handle, bh);
1694                         if (pde)
1695                                 pde->rec_len = ext4_rec_len_to_disk(
1696                                         ext4_rec_len_from_disk(pde->rec_len,
1697                                                                blocksize) +
1698                                         ext4_rec_len_from_disk(de->rec_len,
1699                                                                blocksize),
1700                                         blocksize);
1701                         else
1702                                 de->inode = 0;
1703                         dir->i_version++;
1704                         BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1705                         ext4_handle_dirty_metadata(handle, dir, bh);
1706                         return 0;
1707                 }
1708                 i += ext4_rec_len_from_disk(de->rec_len, blocksize);
1709                 pde = de;
1710                 de = ext4_next_entry(de, blocksize);
1711         }
1712         return -ENOENT;
1713 }
1714
1715 /*
1716  * DIR_NLINK feature is set if 1) nlinks > EXT4_LINK_MAX or 2) nlinks == 2,
1717  * since this indicates that nlinks count was previously 1.
1718  */
1719 static void ext4_inc_count(handle_t *handle, struct inode *inode)
1720 {
1721         inc_nlink(inode);
1722         if (is_dx(inode) && inode->i_nlink > 1) {
1723                 /* limit is 16-bit i_links_count */
1724                 if (inode->i_nlink >= EXT4_LINK_MAX || inode->i_nlink == 2) {
1725                         inode->i_nlink = 1;
1726                         EXT4_SET_RO_COMPAT_FEATURE(inode->i_sb,
1727                                               EXT4_FEATURE_RO_COMPAT_DIR_NLINK);
1728                 }
1729         }
1730 }
1731
1732 /*
1733  * If a directory had nlink == 1, then we should let it be 1. This indicates
1734  * directory has >EXT4_LINK_MAX subdirs.
1735  */
1736 static void ext4_dec_count(handle_t *handle, struct inode *inode)
1737 {
1738         drop_nlink(inode);
1739         if (S_ISDIR(inode->i_mode) && inode->i_nlink == 0)
1740                 inc_nlink(inode);
1741 }
1742
1743
1744 static int ext4_add_nondir(handle_t *handle,
1745                 struct dentry *dentry, struct inode *inode)
1746 {
1747         int err = ext4_add_entry(handle, dentry, inode);
1748         if (!err) {
1749                 ext4_mark_inode_dirty(handle, inode);
1750                 d_instantiate(dentry, inode);
1751                 unlock_new_inode(inode);
1752                 return 0;
1753         }
1754         drop_nlink(inode);
1755         unlock_new_inode(inode);
1756         iput(inode);
1757         return err;
1758 }
1759
1760 /*
1761  * By the time this is called, we already have created
1762  * the directory cache entry for the new file, but it
1763  * is so far negative - it has no inode.
1764  *
1765  * If the create succeeds, we fill in the inode information
1766  * with d_instantiate().
1767  */
1768 static int ext4_create(struct inode *dir, struct dentry *dentry, int mode,
1769                        struct nameidata *nd)
1770 {
1771         handle_t *handle;
1772         struct inode *inode;
1773         int err, retries = 0;
1774
1775 retry:
1776         handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
1777                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
1778                                         2*EXT4_QUOTA_INIT_BLOCKS(dir->i_sb));
1779         if (IS_ERR(handle))
1780                 return PTR_ERR(handle);
1781
1782         if (IS_DIRSYNC(dir))
1783                 ext4_handle_sync(handle);
1784
1785         inode = ext4_new_inode(handle, dir, mode, &dentry->d_name, 0);
1786         err = PTR_ERR(inode);
1787         if (!IS_ERR(inode)) {
1788                 inode->i_op = &ext4_file_inode_operations;
1789                 inode->i_fop = &ext4_file_operations;
1790                 ext4_set_aops(inode);
1791                 err = ext4_add_nondir(handle, dentry, inode);
1792         }
1793         ext4_journal_stop(handle);
1794         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
1795                 goto retry;
1796         return err;
1797 }
1798
1799 static int ext4_mknod(struct inode *dir, struct dentry *dentry,
1800                       int mode, dev_t rdev)
1801 {
1802         handle_t *handle;
1803         struct inode *inode;
1804         int err, retries = 0;
1805
1806         if (!new_valid_dev(rdev))
1807                 return -EINVAL;
1808
1809 retry:
1810         handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
1811                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
1812                                         2*EXT4_QUOTA_INIT_BLOCKS(dir->i_sb));
1813         if (IS_ERR(handle))
1814                 return PTR_ERR(handle);
1815
1816         if (IS_DIRSYNC(dir))
1817                 ext4_handle_sync(handle);
1818
1819         inode = ext4_new_inode(handle, dir, mode, &dentry->d_name, 0);
1820         err = PTR_ERR(inode);
1821         if (!IS_ERR(inode)) {
1822                 init_special_inode(inode, inode->i_mode, rdev);
1823 #ifdef CONFIG_EXT4_FS_XATTR
1824                 inode->i_op = &ext4_special_inode_operations;
1825 #endif
1826                 err = ext4_add_nondir(handle, dentry, inode);
1827         }
1828         ext4_journal_stop(handle);
1829         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
1830                 goto retry;
1831         return err;
1832 }
1833
1834 static int ext4_mkdir(struct inode *dir, struct dentry *dentry, int mode)
1835 {
1836         handle_t *handle;
1837         struct inode *inode;
1838         struct buffer_head *dir_block;
1839         struct ext4_dir_entry_2 *de;
1840         unsigned int blocksize = dir->i_sb->s_blocksize;
1841         int err, retries = 0;
1842
1843         if (EXT4_DIR_LINK_MAX(dir))
1844                 return -EMLINK;
1845
1846 retry:
1847         handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
1848                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
1849                                         2*EXT4_QUOTA_INIT_BLOCKS(dir->i_sb));
1850         if (IS_ERR(handle))
1851                 return PTR_ERR(handle);
1852
1853         if (IS_DIRSYNC(dir))
1854                 ext4_handle_sync(handle);
1855
1856         inode = ext4_new_inode(handle, dir, S_IFDIR | mode,
1857                                &dentry->d_name, 0);
1858         err = PTR_ERR(inode);
1859         if (IS_ERR(inode))
1860                 goto out_stop;
1861
1862         inode->i_op = &ext4_dir_inode_operations;
1863         inode->i_fop = &ext4_dir_operations;
1864         inode->i_size = EXT4_I(inode)->i_disksize = inode->i_sb->s_blocksize;
1865         dir_block = ext4_bread(handle, inode, 0, 1, &err);
1866         if (!dir_block)
1867                 goto out_clear_inode;
1868         BUFFER_TRACE(dir_block, "get_write_access");
1869         ext4_journal_get_write_access(handle, dir_block);
1870         de = (struct ext4_dir_entry_2 *) dir_block->b_data;
1871         de->inode = cpu_to_le32(inode->i_ino);
1872         de->name_len = 1;
1873         de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
1874                                            blocksize);
1875         strcpy(de->name, ".");
1876         ext4_set_de_type(dir->i_sb, de, S_IFDIR);
1877         de = ext4_next_entry(de, blocksize);
1878         de->inode = cpu_to_le32(dir->i_ino);
1879         de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(1),
1880                                            blocksize);
1881         de->name_len = 2;
1882         strcpy(de->name, "..");
1883         ext4_set_de_type(dir->i_sb, de, S_IFDIR);
1884         inode->i_nlink = 2;
1885         BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
1886         ext4_handle_dirty_metadata(handle, dir, dir_block);
1887         brelse(dir_block);
1888         ext4_mark_inode_dirty(handle, inode);
1889         err = ext4_add_entry(handle, dentry, inode);
1890         if (err) {
1891 out_clear_inode:
1892                 clear_nlink(inode);
1893                 unlock_new_inode(inode);
1894                 ext4_mark_inode_dirty(handle, inode);
1895                 iput(inode);
1896                 goto out_stop;
1897         }
1898         ext4_inc_count(handle, dir);
1899         ext4_update_dx_flag(dir);
1900         ext4_mark_inode_dirty(handle, dir);
1901         d_instantiate(dentry, inode);
1902         unlock_new_inode(inode);
1903 out_stop:
1904         ext4_journal_stop(handle);
1905         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
1906                 goto retry;
1907         return err;
1908 }
1909
1910 /*
1911  * routine to check that the specified directory is empty (for rmdir)
1912  */
1913 static int empty_dir(struct inode *inode)
1914 {
1915         unsigned int offset;
1916         struct buffer_head *bh;
1917         struct ext4_dir_entry_2 *de, *de1;
1918         struct super_block *sb;
1919         int err = 0;
1920
1921         sb = inode->i_sb;
1922         if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2) ||
1923             !(bh = ext4_bread(NULL, inode, 0, 0, &err))) {
1924                 if (err)
1925                         ext4_error(inode->i_sb, __func__,
1926                                    "error %d reading directory #%lu offset 0",
1927                                    err, inode->i_ino);
1928                 else
1929                         ext4_warning(inode->i_sb, __func__,
1930                                      "bad directory (dir #%lu) - no data block",
1931                                      inode->i_ino);
1932                 return 1;
1933         }
1934         de = (struct ext4_dir_entry_2 *) bh->b_data;
1935         de1 = ext4_next_entry(de, sb->s_blocksize);
1936         if (le32_to_cpu(de->inode) != inode->i_ino ||
1937                         !le32_to_cpu(de1->inode) ||
1938                         strcmp(".", de->name) ||
1939                         strcmp("..", de1->name)) {
1940                 ext4_warning(inode->i_sb, "empty_dir",
1941                              "bad directory (dir #%lu) - no `.' or `..'",
1942                              inode->i_ino);
1943                 brelse(bh);
1944                 return 1;
1945         }
1946         offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) +
1947                  ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize);
1948         de = ext4_next_entry(de1, sb->s_blocksize);
1949         while (offset < inode->i_size) {
1950                 if (!bh ||
1951                         (void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
1952                         err = 0;
1953                         brelse(bh);
1954                         bh = ext4_bread(NULL, inode,
1955                                 offset >> EXT4_BLOCK_SIZE_BITS(sb), 0, &err);
1956                         if (!bh) {
1957                                 if (err)
1958                                         ext4_error(sb, __func__,
1959                                                    "error %d reading directory"
1960                                                    " #%lu offset %u",
1961                                                    err, inode->i_ino, offset);
1962                                 offset += sb->s_blocksize;
1963                                 continue;
1964                         }
1965                         de = (struct ext4_dir_entry_2 *) bh->b_data;
1966                 }
1967                 if (!ext4_check_dir_entry("empty_dir", inode, de, bh, offset)) {
1968                         de = (struct ext4_dir_entry_2 *)(bh->b_data +
1969                                                          sb->s_blocksize);
1970                         offset = (offset | (sb->s_blocksize - 1)) + 1;
1971                         continue;
1972                 }
1973                 if (le32_to_cpu(de->inode)) {
1974                         brelse(bh);
1975                         return 0;
1976                 }
1977                 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
1978                 de = ext4_next_entry(de, sb->s_blocksize);
1979         }
1980         brelse(bh);
1981         return 1;
1982 }
1983
1984 /* ext4_orphan_add() links an unlinked or truncated inode into a list of
1985  * such inodes, starting at the superblock, in case we crash before the
1986  * file is closed/deleted, or in case the inode truncate spans multiple
1987  * transactions and the last transaction is not recovered after a crash.
1988  *
1989  * At filesystem recovery time, we walk this list deleting unlinked
1990  * inodes and truncating linked inodes in ext4_orphan_cleanup().
1991  */
1992 int ext4_orphan_add(handle_t *handle, struct inode *inode)
1993 {
1994         struct super_block *sb = inode->i_sb;
1995         struct ext4_iloc iloc;
1996         int err = 0, rc;
1997
1998         if (!ext4_handle_valid(handle))
1999                 return 0;
2000
2001         mutex_lock(&EXT4_SB(sb)->s_orphan_lock);
2002         if (!list_empty(&EXT4_I(inode)->i_orphan))
2003                 goto out_unlock;
2004
2005         /* Orphan handling is only valid for files with data blocks
2006          * being truncated, or files being unlinked. */
2007
2008         /* @@@ FIXME: Observation from aviro:
2009          * I think I can trigger J_ASSERT in ext4_orphan_add().  We block
2010          * here (on s_orphan_lock), so race with ext4_link() which might bump
2011          * ->i_nlink. For, say it, character device. Not a regular file,
2012          * not a directory, not a symlink and ->i_nlink > 0.
2013          *
2014          * tytso, 4/25/2009: I'm not sure how that could happen;
2015          * shouldn't the fs core protect us from these sort of
2016          * unlink()/link() races?
2017          */
2018         J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2019                   S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
2020
2021         BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access");
2022         err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
2023         if (err)
2024                 goto out_unlock;
2025
2026         err = ext4_reserve_inode_write(handle, inode, &iloc);
2027         if (err)
2028                 goto out_unlock;
2029
2030         /* Insert this inode at the head of the on-disk orphan list... */
2031         NEXT_ORPHAN(inode) = le32_to_cpu(EXT4_SB(sb)->s_es->s_last_orphan);
2032         EXT4_SB(sb)->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
2033         err = ext4_handle_dirty_metadata(handle, inode, EXT4_SB(sb)->s_sbh);
2034         rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
2035         if (!err)
2036                 err = rc;
2037
2038         /* Only add to the head of the in-memory list if all the
2039          * previous operations succeeded.  If the orphan_add is going to
2040          * fail (possibly taking the journal offline), we can't risk
2041          * leaving the inode on the orphan list: stray orphan-list
2042          * entries can cause panics at unmount time.
2043          *
2044          * This is safe: on error we're going to ignore the orphan list
2045          * anyway on the next recovery. */
2046         if (!err)
2047                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2048
2049         jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
2050         jbd_debug(4, "orphan inode %lu will point to %d\n",
2051                         inode->i_ino, NEXT_ORPHAN(inode));
2052 out_unlock:
2053         mutex_unlock(&EXT4_SB(sb)->s_orphan_lock);
2054         ext4_std_error(inode->i_sb, err);
2055         return err;
2056 }
2057
2058 /*
2059  * ext4_orphan_del() removes an unlinked or truncated inode from the list
2060  * of such inodes stored on disk, because it is finally being cleaned up.
2061  */
2062 int ext4_orphan_del(handle_t *handle, struct inode *inode)
2063 {
2064         struct list_head *prev;
2065         struct ext4_inode_info *ei = EXT4_I(inode);
2066         struct ext4_sb_info *sbi;
2067         __u32 ino_next;
2068         struct ext4_iloc iloc;
2069         int err = 0;
2070
2071         if (!ext4_handle_valid(handle))
2072                 return 0;
2073
2074         mutex_lock(&EXT4_SB(inode->i_sb)->s_orphan_lock);
2075         if (list_empty(&ei->i_orphan))
2076                 goto out;
2077
2078         ino_next = NEXT_ORPHAN(inode);
2079         prev = ei->i_orphan.prev;
2080         sbi = EXT4_SB(inode->i_sb);
2081
2082         jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
2083
2084         list_del_init(&ei->i_orphan);
2085
2086         /* If we're on an error path, we may not have a valid
2087          * transaction handle with which to update the orphan list on
2088          * disk, but we still need to remove the inode from the linked
2089          * list in memory. */
2090         if (sbi->s_journal && !handle)
2091                 goto out;
2092
2093         err = ext4_reserve_inode_write(handle, inode, &iloc);
2094         if (err)
2095                 goto out_err;
2096
2097         if (prev == &sbi->s_orphan) {
2098                 jbd_debug(4, "superblock will point to %u\n", ino_next);
2099                 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2100                 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2101                 if (err)
2102                         goto out_brelse;
2103                 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
2104                 err = ext4_handle_dirty_metadata(handle, inode, sbi->s_sbh);
2105         } else {
2106                 struct ext4_iloc iloc2;
2107                 struct inode *i_prev =
2108                         &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
2109
2110                 jbd_debug(4, "orphan inode %lu will point to %u\n",
2111                           i_prev->i_ino, ino_next);
2112                 err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
2113                 if (err)
2114                         goto out_brelse;
2115                 NEXT_ORPHAN(i_prev) = ino_next;
2116                 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
2117         }
2118         if (err)
2119                 goto out_brelse;
2120         NEXT_ORPHAN(inode) = 0;
2121         err = ext4_mark_iloc_dirty(handle, inode, &iloc);
2122
2123 out_err:
2124         ext4_std_error(inode->i_sb, err);
2125 out:
2126         mutex_unlock(&EXT4_SB(inode->i_sb)->s_orphan_lock);
2127         return err;
2128
2129 out_brelse:
2130         brelse(iloc.bh);
2131         goto out_err;
2132 }
2133
2134 static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
2135 {
2136         int retval;
2137         struct inode *inode;
2138         struct buffer_head *bh;
2139         struct ext4_dir_entry_2 *de;
2140         handle_t *handle;
2141
2142         /* Initialize quotas before so that eventual writes go in
2143          * separate transaction */
2144         vfs_dq_init(dentry->d_inode);
2145         handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb));
2146         if (IS_ERR(handle))
2147                 return PTR_ERR(handle);
2148
2149         retval = -ENOENT;
2150         bh = ext4_find_entry(dir, &dentry->d_name, &de);
2151         if (!bh)
2152                 goto end_rmdir;
2153
2154         if (IS_DIRSYNC(dir))
2155                 ext4_handle_sync(handle);
2156
2157         inode = dentry->d_inode;
2158
2159         retval = -EIO;
2160         if (le32_to_cpu(de->inode) != inode->i_ino)
2161                 goto end_rmdir;
2162
2163         retval = -ENOTEMPTY;
2164         if (!empty_dir(inode))
2165                 goto end_rmdir;
2166
2167         retval = ext4_delete_entry(handle, dir, de, bh);
2168         if (retval)
2169                 goto end_rmdir;
2170         if (!EXT4_DIR_LINK_EMPTY(inode))
2171                 ext4_warning(inode->i_sb, "ext4_rmdir",
2172                              "empty directory has too many links (%d)",
2173                              inode->i_nlink);
2174         inode->i_version++;
2175         clear_nlink(inode);
2176         /* There's no need to set i_disksize: the fact that i_nlink is
2177          * zero will ensure that the right thing happens during any
2178          * recovery. */
2179         inode->i_size = 0;
2180         ext4_orphan_add(handle, inode);
2181         inode->i_ctime = dir->i_ctime = dir->i_mtime = ext4_current_time(inode);
2182         ext4_mark_inode_dirty(handle, inode);
2183         ext4_dec_count(handle, dir);
2184         ext4_update_dx_flag(dir);
2185         ext4_mark_inode_dirty(handle, dir);
2186
2187 end_rmdir:
2188         ext4_journal_stop(handle);
2189         brelse(bh);
2190         return retval;
2191 }
2192
2193 static int ext4_unlink(struct inode *dir, struct dentry *dentry)
2194 {
2195         int retval;
2196         struct inode *inode;
2197         struct buffer_head *bh;
2198         struct ext4_dir_entry_2 *de;
2199         handle_t *handle;
2200
2201         /* Initialize quotas before so that eventual writes go
2202          * in separate transaction */
2203         vfs_dq_init(dentry->d_inode);
2204         handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb));
2205         if (IS_ERR(handle))
2206                 return PTR_ERR(handle);
2207
2208         if (IS_DIRSYNC(dir))
2209                 ext4_handle_sync(handle);
2210
2211         retval = -ENOENT;
2212         bh = ext4_find_entry(dir, &dentry->d_name, &de);
2213         if (!bh)
2214                 goto end_unlink;
2215
2216         inode = dentry->d_inode;
2217
2218         retval = -EIO;
2219         if (le32_to_cpu(de->inode) != inode->i_ino)
2220                 goto end_unlink;
2221
2222         if (!inode->i_nlink) {
2223                 ext4_warning(inode->i_sb, "ext4_unlink",
2224                              "Deleting nonexistent file (%lu), %d",
2225                              inode->i_ino, inode->i_nlink);
2226                 inode->i_nlink = 1;
2227         }
2228         retval = ext4_delete_entry(handle, dir, de, bh);
2229         if (retval)
2230                 goto end_unlink;
2231         dir->i_ctime = dir->i_mtime = ext4_current_time(dir);
2232         ext4_update_dx_flag(dir);
2233         ext4_mark_inode_dirty(handle, dir);
2234         drop_nlink(inode);
2235         if (!inode->i_nlink)
2236                 ext4_orphan_add(handle, inode);
2237         inode->i_ctime = ext4_current_time(inode);
2238         ext4_mark_inode_dirty(handle, inode);
2239         retval = 0;
2240
2241 end_unlink:
2242         ext4_journal_stop(handle);
2243         brelse(bh);
2244         return retval;
2245 }
2246
2247 static int ext4_symlink(struct inode *dir,
2248                         struct dentry *dentry, const char *symname)
2249 {
2250         handle_t *handle;
2251         struct inode *inode;
2252         int l, err, retries = 0;
2253
2254         l = strlen(symname)+1;
2255         if (l > dir->i_sb->s_blocksize)
2256                 return -ENAMETOOLONG;
2257
2258 retry:
2259         handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2260                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS + 5 +
2261                                         2*EXT4_QUOTA_INIT_BLOCKS(dir->i_sb));
2262         if (IS_ERR(handle))
2263                 return PTR_ERR(handle);
2264
2265         if (IS_DIRSYNC(dir))
2266                 ext4_handle_sync(handle);
2267
2268         inode = ext4_new_inode(handle, dir, S_IFLNK|S_IRWXUGO,
2269                                &dentry->d_name, 0);
2270         err = PTR_ERR(inode);
2271         if (IS_ERR(inode))
2272                 goto out_stop;
2273
2274         if (l > sizeof(EXT4_I(inode)->i_data)) {
2275                 inode->i_op = &ext4_symlink_inode_operations;
2276                 ext4_set_aops(inode);
2277                 /*
2278                  * page_symlink() calls into ext4_prepare/commit_write.
2279                  * We have a transaction open.  All is sweetness.  It also sets
2280                  * i_size in generic_commit_write().
2281                  */
2282                 err = __page_symlink(inode, symname, l, 1);
2283                 if (err) {
2284                         clear_nlink(inode);
2285                         unlock_new_inode(inode);
2286                         ext4_mark_inode_dirty(handle, inode);
2287                         iput(inode);
2288                         goto out_stop;
2289                 }
2290         } else {
2291                 /* clear the extent format for fast symlink */
2292                 EXT4_I(inode)->i_flags &= ~EXT4_EXTENTS_FL;
2293                 inode->i_op = &ext4_fast_symlink_inode_operations;
2294                 memcpy((char *)&EXT4_I(inode)->i_data, symname, l);
2295                 inode->i_size = l-1;
2296         }
2297         EXT4_I(inode)->i_disksize = inode->i_size;
2298         err = ext4_add_nondir(handle, dentry, inode);
2299 out_stop:
2300         ext4_journal_stop(handle);
2301         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2302                 goto retry;
2303         return err;
2304 }
2305
2306 static int ext4_link(struct dentry *old_dentry,
2307                      struct inode *dir, struct dentry *dentry)
2308 {
2309         handle_t *handle;
2310         struct inode *inode = old_dentry->d_inode;
2311         int err, retries = 0;
2312
2313         if (EXT4_DIR_LINK_MAX(inode))
2314                 return -EMLINK;
2315
2316         /*
2317          * Return -ENOENT if we've raced with unlink and i_nlink is 0.  Doing
2318          * otherwise has the potential to corrupt the orphan inode list.
2319          */
2320         if (inode->i_nlink == 0)
2321                 return -ENOENT;
2322
2323 retry:
2324         handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2325                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS);
2326         if (IS_ERR(handle))
2327                 return PTR_ERR(handle);
2328
2329         if (IS_DIRSYNC(dir))
2330                 ext4_handle_sync(handle);
2331
2332         inode->i_ctime = ext4_current_time(inode);
2333         ext4_inc_count(handle, inode);
2334         atomic_inc(&inode->i_count);
2335
2336         err = ext4_add_entry(handle, dentry, inode);
2337         if (!err) {
2338                 ext4_mark_inode_dirty(handle, inode);
2339                 d_instantiate(dentry, inode);
2340         } else {
2341                 drop_nlink(inode);
2342                 iput(inode);
2343         }
2344         ext4_journal_stop(handle);
2345         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2346                 goto retry;
2347         return err;
2348 }
2349
2350 #define PARENT_INO(buffer, size) \
2351         (ext4_next_entry((struct ext4_dir_entry_2 *)(buffer), size)->inode)
2352
2353 /*
2354  * Anybody can rename anything with this: the permission checks are left to the
2355  * higher-level routines.
2356  */
2357 static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
2358                        struct inode *new_dir, struct dentry *new_dentry)
2359 {
2360         handle_t *handle;
2361         struct inode *old_inode, *new_inode;
2362         struct buffer_head *old_bh, *new_bh, *dir_bh;
2363         struct ext4_dir_entry_2 *old_de, *new_de;
2364         int retval, force_da_alloc = 0;
2365
2366         old_bh = new_bh = dir_bh = NULL;
2367
2368         /* Initialize quotas before so that eventual writes go
2369          * in separate transaction */
2370         if (new_dentry->d_inode)
2371                 vfs_dq_init(new_dentry->d_inode);
2372         handle = ext4_journal_start(old_dir, 2 *
2373                                         EXT4_DATA_TRANS_BLOCKS(old_dir->i_sb) +
2374                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
2375         if (IS_ERR(handle))
2376                 return PTR_ERR(handle);
2377
2378         if (IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir))
2379                 ext4_handle_sync(handle);
2380
2381         old_bh = ext4_find_entry(old_dir, &old_dentry->d_name, &old_de);
2382         /*
2383          *  Check for inode number is _not_ due to possible IO errors.
2384          *  We might rmdir the source, keep it as pwd of some process
2385          *  and merrily kill the link to whatever was created under the
2386          *  same name. Goodbye sticky bit ;-<
2387          */
2388         old_inode = old_dentry->d_inode;
2389         retval = -ENOENT;
2390         if (!old_bh || le32_to_cpu(old_de->inode) != old_inode->i_ino)
2391                 goto end_rename;
2392
2393         new_inode = new_dentry->d_inode;
2394         new_bh = ext4_find_entry(new_dir, &new_dentry->d_name, &new_de);
2395         if (new_bh) {
2396                 if (!new_inode) {
2397                         brelse(new_bh);
2398                         new_bh = NULL;
2399                 }
2400         }
2401         if (S_ISDIR(old_inode->i_mode)) {
2402                 if (new_inode) {
2403                         retval = -ENOTEMPTY;
2404                         if (!empty_dir(new_inode))
2405                                 goto end_rename;
2406                 }
2407                 retval = -EIO;
2408                 dir_bh = ext4_bread(handle, old_inode, 0, 0, &retval);
2409                 if (!dir_bh)
2410                         goto end_rename;
2411                 if (le32_to_cpu(PARENT_INO(dir_bh->b_data,
2412                                 old_dir->i_sb->s_blocksize)) != old_dir->i_ino)
2413                         goto end_rename;
2414                 retval = -EMLINK;
2415                 if (!new_inode && new_dir != old_dir &&
2416                                 new_dir->i_nlink >= EXT4_LINK_MAX)
2417                         goto end_rename;
2418         }
2419         if (!new_bh) {
2420                 retval = ext4_add_entry(handle, new_dentry, old_inode);
2421                 if (retval)
2422                         goto end_rename;
2423         } else {
2424                 BUFFER_TRACE(new_bh, "get write access");
2425                 ext4_journal_get_write_access(handle, new_bh);
2426                 new_de->inode = cpu_to_le32(old_inode->i_ino);
2427                 if (EXT4_HAS_INCOMPAT_FEATURE(new_dir->i_sb,
2428                                               EXT4_FEATURE_INCOMPAT_FILETYPE))
2429                         new_de->file_type = old_de->file_type;
2430                 new_dir->i_version++;
2431                 new_dir->i_ctime = new_dir->i_mtime =
2432                                         ext4_current_time(new_dir);
2433                 ext4_mark_inode_dirty(handle, new_dir);
2434                 BUFFER_TRACE(new_bh, "call ext4_handle_dirty_metadata");
2435                 ext4_handle_dirty_metadata(handle, new_dir, new_bh);
2436                 brelse(new_bh);
2437                 new_bh = NULL;
2438         }
2439
2440         /*
2441          * Like most other Unix systems, set the ctime for inodes on a
2442          * rename.
2443          */
2444         old_inode->i_ctime = ext4_current_time(old_inode);
2445         ext4_mark_inode_dirty(handle, old_inode);
2446
2447         /*
2448          * ok, that's it
2449          */
2450         if (le32_to_cpu(old_de->inode) != old_inode->i_ino ||
2451             old_de->name_len != old_dentry->d_name.len ||
2452             strncmp(old_de->name, old_dentry->d_name.name, old_de->name_len) ||
2453             (retval = ext4_delete_entry(handle, old_dir,
2454                                         old_de, old_bh)) == -ENOENT) {
2455                 /* old_de could have moved from under us during htree split, so
2456                  * make sure that we are deleting the right entry.  We might
2457                  * also be pointing to a stale entry in the unused part of
2458                  * old_bh so just checking inum and the name isn't enough. */
2459                 struct buffer_head *old_bh2;
2460                 struct ext4_dir_entry_2 *old_de2;
2461
2462                 old_bh2 = ext4_find_entry(old_dir, &old_dentry->d_name, &old_de2);
2463                 if (old_bh2) {
2464                         retval = ext4_delete_entry(handle, old_dir,
2465                                                    old_de2, old_bh2);
2466                         brelse(old_bh2);
2467                 }
2468         }
2469         if (retval) {
2470                 ext4_warning(old_dir->i_sb, "ext4_rename",
2471                                 "Deleting old file (%lu), %d, error=%d",
2472                                 old_dir->i_ino, old_dir->i_nlink, retval);
2473         }
2474
2475         if (new_inode) {
2476                 ext4_dec_count(handle, new_inode);
2477                 new_inode->i_ctime = ext4_current_time(new_inode);
2478         }
2479         old_dir->i_ctime = old_dir->i_mtime = ext4_current_time(old_dir);
2480         ext4_update_dx_flag(old_dir);
2481         if (dir_bh) {
2482                 BUFFER_TRACE(dir_bh, "get_write_access");
2483                 ext4_journal_get_write_access(handle, dir_bh);
2484                 PARENT_INO(dir_bh->b_data, new_dir->i_sb->s_blocksize) =
2485                                                 cpu_to_le32(new_dir->i_ino);
2486                 BUFFER_TRACE(dir_bh, "call ext4_handle_dirty_metadata");
2487                 ext4_handle_dirty_metadata(handle, old_dir, dir_bh);
2488                 ext4_dec_count(handle, old_dir);
2489                 if (new_inode) {
2490                         /* checked empty_dir above, can't have another parent,
2491                          * ext4_dec_count() won't work for many-linked dirs */
2492                         new_inode->i_nlink = 0;
2493                 } else {
2494                         ext4_inc_count(handle, new_dir);
2495                         ext4_update_dx_flag(new_dir);
2496                         ext4_mark_inode_dirty(handle, new_dir);
2497                 }
2498         }
2499         ext4_mark_inode_dirty(handle, old_dir);
2500         if (new_inode) {
2501                 ext4_mark_inode_dirty(handle, new_inode);
2502                 if (!new_inode->i_nlink)
2503                         ext4_orphan_add(handle, new_inode);
2504                 if (!test_opt(new_dir->i_sb, NO_AUTO_DA_ALLOC))
2505                         force_da_alloc = 1;
2506         }
2507         retval = 0;
2508
2509 end_rename:
2510         brelse(dir_bh);
2511         brelse(old_bh);
2512         brelse(new_bh);
2513         ext4_journal_stop(handle);
2514         if (retval == 0 && force_da_alloc)
2515                 ext4_alloc_da_blocks(old_inode);
2516         return retval;
2517 }
2518
2519 /*
2520  * directories can handle most operations...
2521  */
2522 const struct inode_operations ext4_dir_inode_operations = {
2523         .create         = ext4_create,
2524         .lookup         = ext4_lookup,
2525         .link           = ext4_link,
2526         .unlink         = ext4_unlink,
2527         .symlink        = ext4_symlink,
2528         .mkdir          = ext4_mkdir,
2529         .rmdir          = ext4_rmdir,
2530         .mknod          = ext4_mknod,
2531         .rename         = ext4_rename,
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         .permission     = ext4_permission,
2540         .fiemap         = ext4_fiemap,
2541 };
2542
2543 const struct inode_operations ext4_special_inode_operations = {
2544         .setattr        = ext4_setattr,
2545 #ifdef CONFIG_EXT4_FS_XATTR
2546         .setxattr       = generic_setxattr,
2547         .getxattr       = generic_getxattr,
2548         .listxattr      = ext4_listxattr,
2549         .removexattr    = generic_removexattr,
2550 #endif
2551         .permission     = ext4_permission,
2552 };