b754b7721f51fea4dd943a68e436fe5677f301a0
[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 #include <trace/events/ext4.h>
44 /*
45  * define how far ahead to read directories while searching them.
46  */
47 #define NAMEI_RA_CHUNKS  2
48 #define NAMEI_RA_BLOCKS  4
49 #define NAMEI_RA_SIZE        (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS)
50 #define NAMEI_RA_INDEX(c,b)  (((c) * NAMEI_RA_BLOCKS) + (b))
51
52 static struct buffer_head *ext4_append(handle_t *handle,
53                                         struct inode *inode,
54                                         ext4_lblk_t *block, int *err)
55 {
56         struct buffer_head *bh;
57
58         *block = inode->i_size >> inode->i_sb->s_blocksize_bits;
59
60         bh = ext4_bread(handle, inode, *block, 1, err);
61         if (bh) {
62                 inode->i_size += inode->i_sb->s_blocksize;
63                 EXT4_I(inode)->i_disksize = inode->i_size;
64                 *err = ext4_journal_get_write_access(handle, bh);
65                 if (*err) {
66                         brelse(bh);
67                         bh = NULL;
68                 }
69         }
70         return bh;
71 }
72
73 #ifndef assert
74 #define assert(test) J_ASSERT(test)
75 #endif
76
77 #ifdef DX_DEBUG
78 #define dxtrace(command) command
79 #else
80 #define dxtrace(command)
81 #endif
82
83 struct fake_dirent
84 {
85         __le32 inode;
86         __le16 rec_len;
87         u8 name_len;
88         u8 file_type;
89 };
90
91 struct dx_countlimit
92 {
93         __le16 limit;
94         __le16 count;
95 };
96
97 struct dx_entry
98 {
99         __le32 hash;
100         __le32 block;
101 };
102
103 /*
104  * dx_root_info is laid out so that if it should somehow get overlaid by a
105  * dirent the two low bits of the hash version will be zero.  Therefore, the
106  * hash version mod 4 should never be 0.  Sincerely, the paranoia department.
107  */
108
109 struct dx_root
110 {
111         struct fake_dirent dot;
112         char dot_name[4];
113         struct fake_dirent dotdot;
114         char dotdot_name[4];
115         struct dx_root_info
116         {
117                 __le32 reserved_zero;
118                 u8 hash_version;
119                 u8 info_length; /* 8 */
120                 u8 indirect_levels;
121                 u8 unused_flags;
122         }
123         info;
124         struct dx_entry entries[0];
125 };
126
127 struct dx_node
128 {
129         struct fake_dirent fake;
130         struct dx_entry entries[0];
131 };
132
133
134 struct dx_frame
135 {
136         struct buffer_head *bh;
137         struct dx_entry *entries;
138         struct dx_entry *at;
139 };
140
141 struct dx_map_entry
142 {
143         u32 hash;
144         u16 offs;
145         u16 size;
146 };
147
148 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
149 static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
150 static inline unsigned dx_get_hash(struct dx_entry *entry);
151 static void dx_set_hash(struct dx_entry *entry, unsigned value);
152 static unsigned dx_get_count(struct dx_entry *entries);
153 static unsigned dx_get_limit(struct dx_entry *entries);
154 static void dx_set_count(struct dx_entry *entries, unsigned value);
155 static void dx_set_limit(struct dx_entry *entries, unsigned value);
156 static unsigned dx_root_limit(struct inode *dir, unsigned infosize);
157 static unsigned dx_node_limit(struct inode *dir);
158 static struct dx_frame *dx_probe(const struct qstr *d_name,
159                                  struct inode *dir,
160                                  struct dx_hash_info *hinfo,
161                                  struct dx_frame *frame,
162                                  int *err);
163 static void dx_release(struct dx_frame *frames);
164 static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize,
165                        struct dx_hash_info *hinfo, struct dx_map_entry map[]);
166 static void dx_sort_map(struct dx_map_entry *map, unsigned count);
167 static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to,
168                 struct dx_map_entry *offsets, int count, unsigned blocksize);
169 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize);
170 static void dx_insert_block(struct dx_frame *frame,
171                                         u32 hash, ext4_lblk_t block);
172 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
173                                  struct dx_frame *frame,
174                                  struct dx_frame *frames,
175                                  __u32 *start_hash);
176 static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
177                 const struct qstr *d_name,
178                 struct ext4_dir_entry_2 **res_dir,
179                 int *err);
180 static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
181                              struct inode *inode);
182
183 /*
184  * p is at least 6 bytes before the end of page
185  */
186 static inline struct ext4_dir_entry_2 *
187 ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
188 {
189         return (struct ext4_dir_entry_2 *)((char *)p +
190                 ext4_rec_len_from_disk(p->rec_len, blocksize));
191 }
192
193 /*
194  * Future: use high four bits of block for coalesce-on-delete flags
195  * Mask them off for now.
196  */
197
198 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
199 {
200         return le32_to_cpu(entry->block) & 0x00ffffff;
201 }
202
203 static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
204 {
205         entry->block = cpu_to_le32(value);
206 }
207
208 static inline unsigned dx_get_hash(struct dx_entry *entry)
209 {
210         return le32_to_cpu(entry->hash);
211 }
212
213 static inline void dx_set_hash(struct dx_entry *entry, unsigned value)
214 {
215         entry->hash = cpu_to_le32(value);
216 }
217
218 static inline unsigned dx_get_count(struct dx_entry *entries)
219 {
220         return le16_to_cpu(((struct dx_countlimit *) entries)->count);
221 }
222
223 static inline unsigned dx_get_limit(struct dx_entry *entries)
224 {
225         return le16_to_cpu(((struct dx_countlimit *) entries)->limit);
226 }
227
228 static inline void dx_set_count(struct dx_entry *entries, unsigned value)
229 {
230         ((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
231 }
232
233 static inline void dx_set_limit(struct dx_entry *entries, unsigned value)
234 {
235         ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
236 }
237
238 static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
239 {
240         unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
241                 EXT4_DIR_REC_LEN(2) - infosize;
242         return entry_space / sizeof(struct dx_entry);
243 }
244
245 static inline unsigned dx_node_limit(struct inode *dir)
246 {
247         unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);
248         return entry_space / sizeof(struct dx_entry);
249 }
250
251 /*
252  * Debug
253  */
254 #ifdef DX_DEBUG
255 static void dx_show_index(char * label, struct dx_entry *entries)
256 {
257         int i, n = dx_get_count (entries);
258         printk(KERN_DEBUG "%s index ", label);
259         for (i = 0; i < n; i++) {
260                 printk("%x->%lu ", i ? dx_get_hash(entries + i) :
261                                 0, (unsigned long)dx_get_block(entries + i));
262         }
263         printk("\n");
264 }
265
266 struct stats
267 {
268         unsigned names;
269         unsigned space;
270         unsigned bcount;
271 };
272
273 static struct stats dx_show_leaf(struct dx_hash_info *hinfo, struct ext4_dir_entry_2 *de,
274                                  int size, int show_names)
275 {
276         unsigned names = 0, space = 0;
277         char *base = (char *) de;
278         struct dx_hash_info h = *hinfo;
279
280         printk("names: ");
281         while ((char *) de < base + size)
282         {
283                 if (de->inode)
284                 {
285                         if (show_names)
286                         {
287                                 int len = de->name_len;
288                                 char *name = de->name;
289                                 while (len--) printk("%c", *name++);
290                                 ext4fs_dirhash(de->name, de->name_len, &h);
291                                 printk(":%x.%u ", h.hash,
292                                        ((char *) de - base));
293                         }
294                         space += EXT4_DIR_REC_LEN(de->name_len);
295                         names++;
296                 }
297                 de = ext4_next_entry(de, size);
298         }
299         printk("(%i)\n", names);
300         return (struct stats) { names, space, 1 };
301 }
302
303 struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
304                              struct dx_entry *entries, int levels)
305 {
306         unsigned blocksize = dir->i_sb->s_blocksize;
307         unsigned count = dx_get_count(entries), names = 0, space = 0, i;
308         unsigned bcount = 0;
309         struct buffer_head *bh;
310         int err;
311         printk("%i indexed blocks...\n", count);
312         for (i = 0; i < count; i++, entries++)
313         {
314                 ext4_lblk_t block = dx_get_block(entries);
315                 ext4_lblk_t hash  = i ? dx_get_hash(entries): 0;
316                 u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
317                 struct stats stats;
318                 printk("%s%3u:%03u hash %8x/%8x ",levels?"":"   ", i, block, hash, range);
319                 if (!(bh = ext4_bread (NULL,dir, block, 0,&err))) continue;
320                 stats = levels?
321                    dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
322                    dx_show_leaf(hinfo, (struct ext4_dir_entry_2 *) bh->b_data, blocksize, 0);
323                 names += stats.names;
324                 space += stats.space;
325                 bcount += stats.bcount;
326                 brelse(bh);
327         }
328         if (bcount)
329                 printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n",
330                        levels ? "" : "   ", names, space/bcount,
331                        (space/bcount)*100/blocksize);
332         return (struct stats) { names, space, bcount};
333 }
334 #endif /* DX_DEBUG */
335
336 /*
337  * Probe for a directory leaf block to search.
338  *
339  * dx_probe can return ERR_BAD_DX_DIR, which means there was a format
340  * error in the directory index, and the caller should fall back to
341  * searching the directory normally.  The callers of dx_probe **MUST**
342  * check for this error code, and make sure it never gets reflected
343  * back to userspace.
344  */
345 static struct dx_frame *
346 dx_probe(const struct qstr *d_name, struct inode *dir,
347          struct dx_hash_info *hinfo, struct dx_frame *frame_in, int *err)
348 {
349         unsigned count, indirect;
350         struct dx_entry *at, *entries, *p, *q, *m;
351         struct dx_root *root;
352         struct buffer_head *bh;
353         struct dx_frame *frame = frame_in;
354         u32 hash;
355
356         frame->bh = NULL;
357         if (!(bh = ext4_bread (NULL,dir, 0, 0, err)))
358                 goto fail;
359         root = (struct dx_root *) bh->b_data;
360         if (root->info.hash_version != DX_HASH_TEA &&
361             root->info.hash_version != DX_HASH_HALF_MD4 &&
362             root->info.hash_version != DX_HASH_LEGACY) {
363                 ext4_warning(dir->i_sb, "Unrecognised inode hash code %d",
364                              root->info.hash_version);
365                 brelse(bh);
366                 *err = ERR_BAD_DX_DIR;
367                 goto fail;
368         }
369         hinfo->hash_version = root->info.hash_version;
370         if (hinfo->hash_version <= DX_HASH_TEA)
371                 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
372         hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
373         if (d_name)
374                 ext4fs_dirhash(d_name->name, d_name->len, hinfo);
375         hash = hinfo->hash;
376
377         if (root->info.unused_flags & 1) {
378                 ext4_warning(dir->i_sb, "Unimplemented inode hash flags: %#06x",
379                              root->info.unused_flags);
380                 brelse(bh);
381                 *err = ERR_BAD_DX_DIR;
382                 goto fail;
383         }
384
385         if ((indirect = root->info.indirect_levels) > 1) {
386                 ext4_warning(dir->i_sb, "Unimplemented inode hash depth: %#06x",
387                              root->info.indirect_levels);
388                 brelse(bh);
389                 *err = ERR_BAD_DX_DIR;
390                 goto fail;
391         }
392
393         entries = (struct dx_entry *) (((char *)&root->info) +
394                                        root->info.info_length);
395
396         if (dx_get_limit(entries) != dx_root_limit(dir,
397                                                    root->info.info_length)) {
398                 ext4_warning(dir->i_sb, "dx entry: limit != root limit");
399                 brelse(bh);
400                 *err = ERR_BAD_DX_DIR;
401                 goto fail;
402         }
403
404         dxtrace(printk("Look up %x", hash));
405         while (1)
406         {
407                 count = dx_get_count(entries);
408                 if (!count || count > dx_get_limit(entries)) {
409                         ext4_warning(dir->i_sb,
410                                      "dx entry: no count or count > limit");
411                         brelse(bh);
412                         *err = ERR_BAD_DX_DIR;
413                         goto fail2;
414                 }
415
416                 p = entries + 1;
417                 q = entries + count - 1;
418                 while (p <= q)
419                 {
420                         m = p + (q - p)/2;
421                         dxtrace(printk("."));
422                         if (dx_get_hash(m) > hash)
423                                 q = m - 1;
424                         else
425                                 p = m + 1;
426                 }
427
428                 if (0) // linear search cross check
429                 {
430                         unsigned n = count - 1;
431                         at = entries;
432                         while (n--)
433                         {
434                                 dxtrace(printk(","));
435                                 if (dx_get_hash(++at) > hash)
436                                 {
437                                         at--;
438                                         break;
439                                 }
440                         }
441                         assert (at == p - 1);
442                 }
443
444                 at = p - 1;
445                 dxtrace(printk(" %x->%u\n", at == entries? 0: dx_get_hash(at), dx_get_block(at)));
446                 frame->bh = bh;
447                 frame->entries = entries;
448                 frame->at = at;
449                 if (!indirect--) return frame;
450                 if (!(bh = ext4_bread (NULL,dir, dx_get_block(at), 0, err)))
451                         goto fail2;
452                 at = entries = ((struct dx_node *) bh->b_data)->entries;
453                 if (dx_get_limit(entries) != dx_node_limit (dir)) {
454                         ext4_warning(dir->i_sb,
455                                      "dx entry: limit != node limit");
456                         brelse(bh);
457                         *err = ERR_BAD_DX_DIR;
458                         goto fail2;
459                 }
460                 frame++;
461                 frame->bh = NULL;
462         }
463 fail2:
464         while (frame >= frame_in) {
465                 brelse(frame->bh);
466                 frame--;
467         }
468 fail:
469         if (*err == ERR_BAD_DX_DIR)
470                 ext4_warning(dir->i_sb,
471                              "Corrupt dir inode %ld, running e2fsck is "
472                              "recommended.", dir->i_ino);
473         return NULL;
474 }
475
476 static void dx_release (struct dx_frame *frames)
477 {
478         if (frames[0].bh == NULL)
479                 return;
480
481         if (((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels)
482                 brelse(frames[1].bh);
483         brelse(frames[0].bh);
484 }
485
486 /*
487  * This function increments the frame pointer to search the next leaf
488  * block, and reads in the necessary intervening nodes if the search
489  * should be necessary.  Whether or not the search is necessary is
490  * controlled by the hash parameter.  If the hash value is even, then
491  * the search is only continued if the next block starts with that
492  * hash value.  This is used if we are searching for a specific file.
493  *
494  * If the hash value is HASH_NB_ALWAYS, then always go to the next block.
495  *
496  * This function returns 1 if the caller should continue to search,
497  * or 0 if it should not.  If there is an error reading one of the
498  * index blocks, it will a negative error code.
499  *
500  * If start_hash is non-null, it will be filled in with the starting
501  * hash of the next page.
502  */
503 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
504                                  struct dx_frame *frame,
505                                  struct dx_frame *frames,
506                                  __u32 *start_hash)
507 {
508         struct dx_frame *p;
509         struct buffer_head *bh;
510         int err, num_frames = 0;
511         __u32 bhash;
512
513         p = frame;
514         /*
515          * Find the next leaf page by incrementing the frame pointer.
516          * If we run out of entries in the interior node, loop around and
517          * increment pointer in the parent node.  When we break out of
518          * this loop, num_frames indicates the number of interior
519          * nodes need to be read.
520          */
521         while (1) {
522                 if (++(p->at) < p->entries + dx_get_count(p->entries))
523                         break;
524                 if (p == frames)
525                         return 0;
526                 num_frames++;
527                 p--;
528         }
529
530         /*
531          * If the hash is 1, then continue only if the next page has a
532          * continuation hash of any value.  This is used for readdir
533          * handling.  Otherwise, check to see if the hash matches the
534          * desired contiuation hash.  If it doesn't, return since
535          * there's no point to read in the successive index pages.
536          */
537         bhash = dx_get_hash(p->at);
538         if (start_hash)
539                 *start_hash = bhash;
540         if ((hash & 1) == 0) {
541                 if ((bhash & ~1) != hash)
542                         return 0;
543         }
544         /*
545          * If the hash is HASH_NB_ALWAYS, we always go to the next
546          * block so no check is necessary
547          */
548         while (num_frames--) {
549                 if (!(bh = ext4_bread(NULL, dir, dx_get_block(p->at),
550                                       0, &err)))
551                         return err; /* Failure */
552                 p++;
553                 brelse(p->bh);
554                 p->bh = bh;
555                 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
556         }
557         return 1;
558 }
559
560
561 /*
562  * This function fills a red-black tree with information from a
563  * directory block.  It returns the number directory entries loaded
564  * into the tree.  If there is an error it is returned in err.
565  */
566 static int htree_dirblock_to_tree(struct file *dir_file,
567                                   struct inode *dir, ext4_lblk_t block,
568                                   struct dx_hash_info *hinfo,
569                                   __u32 start_hash, __u32 start_minor_hash)
570 {
571         struct buffer_head *bh;
572         struct ext4_dir_entry_2 *de, *top;
573         int err, count = 0;
574
575         dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
576                                                         (unsigned long)block));
577         if (!(bh = ext4_bread (NULL, dir, block, 0, &err)))
578                 return err;
579
580         de = (struct ext4_dir_entry_2 *) bh->b_data;
581         top = (struct ext4_dir_entry_2 *) ((char *) de +
582                                            dir->i_sb->s_blocksize -
583                                            EXT4_DIR_REC_LEN(0));
584         for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) {
585                 if (ext4_check_dir_entry(dir, NULL, de, bh,
586                                 (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
587                                          + ((char *)de - bh->b_data))) {
588                         /* On error, skip the f_pos to the next block. */
589                         dir_file->f_pos = (dir_file->f_pos |
590                                         (dir->i_sb->s_blocksize - 1)) + 1;
591                         brelse(bh);
592                         return count;
593                 }
594                 ext4fs_dirhash(de->name, de->name_len, hinfo);
595                 if ((hinfo->hash < start_hash) ||
596                     ((hinfo->hash == start_hash) &&
597                      (hinfo->minor_hash < start_minor_hash)))
598                         continue;
599                 if (de->inode == 0)
600                         continue;
601                 if ((err = ext4_htree_store_dirent(dir_file,
602                                    hinfo->hash, hinfo->minor_hash, de)) != 0) {
603                         brelse(bh);
604                         return err;
605                 }
606                 count++;
607         }
608         brelse(bh);
609         return count;
610 }
611
612
613 /*
614  * This function fills a red-black tree with information from a
615  * directory.  We start scanning the directory in hash order, starting
616  * at start_hash and start_minor_hash.
617  *
618  * This function returns the number of entries inserted into the tree,
619  * or a negative error code.
620  */
621 int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
622                          __u32 start_minor_hash, __u32 *next_hash)
623 {
624         struct dx_hash_info hinfo;
625         struct ext4_dir_entry_2 *de;
626         struct dx_frame frames[2], *frame;
627         struct inode *dir;
628         ext4_lblk_t block;
629         int count = 0;
630         int ret, err;
631         __u32 hashval;
632
633         dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
634                        start_hash, start_minor_hash));
635         dir = dir_file->f_path.dentry->d_inode;
636         if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) {
637                 hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
638                 if (hinfo.hash_version <= DX_HASH_TEA)
639                         hinfo.hash_version +=
640                                 EXT4_SB(dir->i_sb)->s_hash_unsigned;
641                 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
642                 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
643                                                start_hash, start_minor_hash);
644                 *next_hash = ~0;
645                 return count;
646         }
647         hinfo.hash = start_hash;
648         hinfo.minor_hash = 0;
649         frame = dx_probe(NULL, dir, &hinfo, frames, &err);
650         if (!frame)
651                 return err;
652
653         /* Add '.' and '..' from the htree header */
654         if (!start_hash && !start_minor_hash) {
655                 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
656                 if ((err = ext4_htree_store_dirent(dir_file, 0, 0, de)) != 0)
657                         goto errout;
658                 count++;
659         }
660         if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
661                 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
662                 de = ext4_next_entry(de, dir->i_sb->s_blocksize);
663                 if ((err = ext4_htree_store_dirent(dir_file, 2, 0, de)) != 0)
664                         goto errout;
665                 count++;
666         }
667
668         while (1) {
669                 block = dx_get_block(frame->at);
670                 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
671                                              start_hash, start_minor_hash);
672                 if (ret < 0) {
673                         err = ret;
674                         goto errout;
675                 }
676                 count += ret;
677                 hashval = ~0;
678                 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
679                                             frame, frames, &hashval);
680                 *next_hash = hashval;
681                 if (ret < 0) {
682                         err = ret;
683                         goto errout;
684                 }
685                 /*
686                  * Stop if:  (a) there are no more entries, or
687                  * (b) we have inserted at least one entry and the
688                  * next hash value is not a continuation
689                  */
690                 if ((ret == 0) ||
691                     (count && ((hashval & 1) == 0)))
692                         break;
693         }
694         dx_release(frames);
695         dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, "
696                        "next hash: %x\n", count, *next_hash));
697         return count;
698 errout:
699         dx_release(frames);
700         return (err);
701 }
702
703
704 /*
705  * Directory block splitting, compacting
706  */
707
708 /*
709  * Create map of hash values, offsets, and sizes, stored at end of block.
710  * Returns number of entries mapped.
711  */
712 static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize,
713                        struct dx_hash_info *hinfo,
714                        struct dx_map_entry *map_tail)
715 {
716         int count = 0;
717         char *base = (char *) de;
718         struct dx_hash_info h = *hinfo;
719
720         while ((char *) de < base + blocksize) {
721                 if (de->name_len && de->inode) {
722                         ext4fs_dirhash(de->name, de->name_len, &h);
723                         map_tail--;
724                         map_tail->hash = h.hash;
725                         map_tail->offs = ((char *) de - base)>>2;
726                         map_tail->size = le16_to_cpu(de->rec_len);
727                         count++;
728                         cond_resched();
729                 }
730                 /* XXX: do we need to check rec_len == 0 case? -Chris */
731                 de = ext4_next_entry(de, blocksize);
732         }
733         return count;
734 }
735
736 /* Sort map by hash value */
737 static void dx_sort_map (struct dx_map_entry *map, unsigned count)
738 {
739         struct dx_map_entry *p, *q, *top = map + count - 1;
740         int more;
741         /* Combsort until bubble sort doesn't suck */
742         while (count > 2) {
743                 count = count*10/13;
744                 if (count - 9 < 2) /* 9, 10 -> 11 */
745                         count = 11;
746                 for (p = top, q = p - count; q >= map; p--, q--)
747                         if (p->hash < q->hash)
748                                 swap(*p, *q);
749         }
750         /* Garden variety bubble sort */
751         do {
752                 more = 0;
753                 q = top;
754                 while (q-- > map) {
755                         if (q[1].hash >= q[0].hash)
756                                 continue;
757                         swap(*(q+1), *q);
758                         more = 1;
759                 }
760         } while(more);
761 }
762
763 static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
764 {
765         struct dx_entry *entries = frame->entries;
766         struct dx_entry *old = frame->at, *new = old + 1;
767         int count = dx_get_count(entries);
768
769         assert(count < dx_get_limit(entries));
770         assert(old < entries + count);
771         memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
772         dx_set_hash(new, hash);
773         dx_set_block(new, block);
774         dx_set_count(entries, count + 1);
775 }
776
777 static void ext4_update_dx_flag(struct inode *inode)
778 {
779         if (!EXT4_HAS_COMPAT_FEATURE(inode->i_sb,
780                                      EXT4_FEATURE_COMPAT_DIR_INDEX))
781                 ext4_clear_inode_flag(inode, EXT4_INODE_INDEX);
782 }
783
784 /*
785  * NOTE! unlike strncmp, ext4_match returns 1 for success, 0 for failure.
786  *
787  * `len <= EXT4_NAME_LEN' is guaranteed by caller.
788  * `de != NULL' is guaranteed by caller.
789  */
790 static inline int ext4_match (int len, const char * const name,
791                               struct ext4_dir_entry_2 * de)
792 {
793         if (len != de->name_len)
794                 return 0;
795         if (!de->inode)
796                 return 0;
797         return !memcmp(name, de->name, len);
798 }
799
800 /*
801  * Returns 0 if not found, -1 on failure, and 1 on success
802  */
803 static inline int search_dirblock(struct buffer_head *bh,
804                                   struct inode *dir,
805                                   const struct qstr *d_name,
806                                   unsigned int offset,
807                                   struct ext4_dir_entry_2 ** res_dir)
808 {
809         struct ext4_dir_entry_2 * de;
810         char * dlimit;
811         int de_len;
812         const char *name = d_name->name;
813         int namelen = d_name->len;
814
815         de = (struct ext4_dir_entry_2 *) bh->b_data;
816         dlimit = bh->b_data + dir->i_sb->s_blocksize;
817         while ((char *) de < dlimit) {
818                 /* this code is executed quadratically often */
819                 /* do minimal checking `by hand' */
820
821                 if ((char *) de + namelen <= dlimit &&
822                     ext4_match (namelen, name, de)) {
823                         /* found a match - just to be sure, do a full check */
824                         if (ext4_check_dir_entry(dir, NULL, de, bh, offset))
825                                 return -1;
826                         *res_dir = de;
827                         return 1;
828                 }
829                 /* prevent looping on a bad block */
830                 de_len = ext4_rec_len_from_disk(de->rec_len,
831                                                 dir->i_sb->s_blocksize);
832                 if (de_len <= 0)
833                         return -1;
834                 offset += de_len;
835                 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
836         }
837         return 0;
838 }
839
840
841 /*
842  *      ext4_find_entry()
843  *
844  * finds an entry in the specified directory with the wanted name. It
845  * returns the cache buffer in which the entry was found, and the entry
846  * itself (as a parameter - res_dir). It does NOT read the inode of the
847  * entry - you'll have to do that yourself if you want to.
848  *
849  * The returned buffer_head has ->b_count elevated.  The caller is expected
850  * to brelse() it when appropriate.
851  */
852 static struct buffer_head * ext4_find_entry (struct inode *dir,
853                                         const struct qstr *d_name,
854                                         struct ext4_dir_entry_2 ** res_dir)
855 {
856         struct super_block *sb;
857         struct buffer_head *bh_use[NAMEI_RA_SIZE];
858         struct buffer_head *bh, *ret = NULL;
859         ext4_lblk_t start, block, b;
860         const u8 *name = d_name->name;
861         int ra_max = 0;         /* Number of bh's in the readahead
862                                    buffer, bh_use[] */
863         int ra_ptr = 0;         /* Current index into readahead
864                                    buffer */
865         int num = 0;
866         ext4_lblk_t  nblocks;
867         int i, err;
868         int namelen;
869
870         *res_dir = NULL;
871         sb = dir->i_sb;
872         namelen = d_name->len;
873         if (namelen > EXT4_NAME_LEN)
874                 return NULL;
875         if ((namelen <= 2) && (name[0] == '.') &&
876             (name[1] == '.' || name[1] == '\0')) {
877                 /*
878                  * "." or ".." will only be in the first block
879                  * NFS may look up ".."; "." should be handled by the VFS
880                  */
881                 block = start = 0;
882                 nblocks = 1;
883                 goto restart;
884         }
885         if (is_dx(dir)) {
886                 bh = ext4_dx_find_entry(dir, d_name, res_dir, &err);
887                 /*
888                  * On success, or if the error was file not found,
889                  * return.  Otherwise, fall back to doing a search the
890                  * old fashioned way.
891                  */
892                 if (bh || (err != ERR_BAD_DX_DIR))
893                         return bh;
894                 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
895                                "falling back\n"));
896         }
897         nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
898         start = EXT4_I(dir)->i_dir_start_lookup;
899         if (start >= nblocks)
900                 start = 0;
901         block = start;
902 restart:
903         do {
904                 /*
905                  * We deal with the read-ahead logic here.
906                  */
907                 if (ra_ptr >= ra_max) {
908                         /* Refill the readahead buffer */
909                         ra_ptr = 0;
910                         b = block;
911                         for (ra_max = 0; ra_max < NAMEI_RA_SIZE; ra_max++) {
912                                 /*
913                                  * Terminate if we reach the end of the
914                                  * directory and must wrap, or if our
915                                  * search has finished at this block.
916                                  */
917                                 if (b >= nblocks || (num && block == start)) {
918                                         bh_use[ra_max] = NULL;
919                                         break;
920                                 }
921                                 num++;
922                                 bh = ext4_getblk(NULL, dir, b++, 0, &err);
923                                 bh_use[ra_max] = bh;
924                                 if (bh)
925                                         ll_rw_block(READ_META, 1, &bh);
926                         }
927                 }
928                 if ((bh = bh_use[ra_ptr++]) == NULL)
929                         goto next;
930                 wait_on_buffer(bh);
931                 if (!buffer_uptodate(bh)) {
932                         /* read error, skip block & hope for the best */
933                         EXT4_ERROR_INODE(dir, "reading directory lblock %lu",
934                                          (unsigned long) block);
935                         brelse(bh);
936                         goto next;
937                 }
938                 i = search_dirblock(bh, dir, d_name,
939                             block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
940                 if (i == 1) {
941                         EXT4_I(dir)->i_dir_start_lookup = block;
942                         ret = bh;
943                         goto cleanup_and_exit;
944                 } else {
945                         brelse(bh);
946                         if (i < 0)
947                                 goto cleanup_and_exit;
948                 }
949         next:
950                 if (++block >= nblocks)
951                         block = 0;
952         } while (block != start);
953
954         /*
955          * If the directory has grown while we were searching, then
956          * search the last part of the directory before giving up.
957          */
958         block = nblocks;
959         nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
960         if (block < nblocks) {
961                 start = 0;
962                 goto restart;
963         }
964
965 cleanup_and_exit:
966         /* Clean up the read-ahead blocks */
967         for (; ra_ptr < ra_max; ra_ptr++)
968                 brelse(bh_use[ra_ptr]);
969         return ret;
970 }
971
972 static struct buffer_head * ext4_dx_find_entry(struct inode *dir, const struct qstr *d_name,
973                        struct ext4_dir_entry_2 **res_dir, int *err)
974 {
975         struct super_block * sb = dir->i_sb;
976         struct dx_hash_info     hinfo;
977         struct dx_frame frames[2], *frame;
978         struct buffer_head *bh;
979         ext4_lblk_t block;
980         int retval;
981
982         if (!(frame = dx_probe(d_name, dir, &hinfo, frames, err)))
983                 return NULL;
984         do {
985                 block = dx_get_block(frame->at);
986                 if (!(bh = ext4_bread(NULL, dir, block, 0, err)))
987                         goto errout;
988
989                 retval = search_dirblock(bh, dir, d_name,
990                                          block << EXT4_BLOCK_SIZE_BITS(sb),
991                                          res_dir);
992                 if (retval == 1) {      /* Success! */
993                         dx_release(frames);
994                         return bh;
995                 }
996                 brelse(bh);
997                 if (retval == -1) {
998                         *err = ERR_BAD_DX_DIR;
999                         goto errout;
1000                 }
1001
1002                 /* Check to see if we should continue to search */
1003                 retval = ext4_htree_next_block(dir, hinfo.hash, frame,
1004                                                frames, NULL);
1005                 if (retval < 0) {
1006                         ext4_warning(sb,
1007                              "error reading index page in directory #%lu",
1008                              dir->i_ino);
1009                         *err = retval;
1010                         goto errout;
1011                 }
1012         } while (retval == 1);
1013
1014         *err = -ENOENT;
1015 errout:
1016         dxtrace(printk(KERN_DEBUG "%s not found\n", name));
1017         dx_release (frames);
1018         return NULL;
1019 }
1020
1021 static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
1022 {
1023         struct inode *inode;
1024         struct ext4_dir_entry_2 *de;
1025         struct buffer_head *bh;
1026
1027         if (dentry->d_name.len > EXT4_NAME_LEN)
1028                 return ERR_PTR(-ENAMETOOLONG);
1029
1030         bh = ext4_find_entry(dir, &dentry->d_name, &de);
1031         inode = NULL;
1032         if (bh) {
1033                 __u32 ino = le32_to_cpu(de->inode);
1034                 brelse(bh);
1035                 if (!ext4_valid_inum(dir->i_sb, ino)) {
1036                         EXT4_ERROR_INODE(dir, "bad inode number: %u", ino);
1037                         return ERR_PTR(-EIO);
1038                 }
1039                 inode = ext4_iget(dir->i_sb, ino);
1040                 if (IS_ERR(inode)) {
1041                         if (PTR_ERR(inode) == -ESTALE) {
1042                                 EXT4_ERROR_INODE(dir,
1043                                                  "deleted inode referenced: %u",
1044                                                  ino);
1045                                 return ERR_PTR(-EIO);
1046                         } else {
1047                                 return ERR_CAST(inode);
1048                         }
1049                 }
1050         }
1051         return d_splice_alias(inode, dentry);
1052 }
1053
1054
1055 struct dentry *ext4_get_parent(struct dentry *child)
1056 {
1057         __u32 ino;
1058         static const struct qstr dotdot = {
1059                 .name = "..",
1060                 .len = 2,
1061         };
1062         struct ext4_dir_entry_2 * de;
1063         struct buffer_head *bh;
1064
1065         bh = ext4_find_entry(child->d_inode, &dotdot, &de);
1066         if (!bh)
1067                 return ERR_PTR(-ENOENT);
1068         ino = le32_to_cpu(de->inode);
1069         brelse(bh);
1070
1071         if (!ext4_valid_inum(child->d_inode->i_sb, ino)) {
1072                 EXT4_ERROR_INODE(child->d_inode,
1073                                  "bad parent inode number: %u", ino);
1074                 return ERR_PTR(-EIO);
1075         }
1076
1077         return d_obtain_alias(ext4_iget(child->d_inode->i_sb, ino));
1078 }
1079
1080 #define S_SHIFT 12
1081 static unsigned char ext4_type_by_mode[S_IFMT >> S_SHIFT] = {
1082         [S_IFREG >> S_SHIFT]    = EXT4_FT_REG_FILE,
1083         [S_IFDIR >> S_SHIFT]    = EXT4_FT_DIR,
1084         [S_IFCHR >> S_SHIFT]    = EXT4_FT_CHRDEV,
1085         [S_IFBLK >> S_SHIFT]    = EXT4_FT_BLKDEV,
1086         [S_IFIFO >> S_SHIFT]    = EXT4_FT_FIFO,
1087         [S_IFSOCK >> S_SHIFT]   = EXT4_FT_SOCK,
1088         [S_IFLNK >> S_SHIFT]    = EXT4_FT_SYMLINK,
1089 };
1090
1091 static inline void ext4_set_de_type(struct super_block *sb,
1092                                 struct ext4_dir_entry_2 *de,
1093                                 umode_t mode) {
1094         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE))
1095                 de->file_type = ext4_type_by_mode[(mode & S_IFMT)>>S_SHIFT];
1096 }
1097
1098 /*
1099  * Move count entries from end of map between two memory locations.
1100  * Returns pointer to last entry moved.
1101  */
1102 static struct ext4_dir_entry_2 *
1103 dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count,
1104                 unsigned blocksize)
1105 {
1106         unsigned rec_len = 0;
1107
1108         while (count--) {
1109                 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
1110                                                 (from + (map->offs<<2));
1111                 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1112                 memcpy (to, de, rec_len);
1113                 ((struct ext4_dir_entry_2 *) to)->rec_len =
1114                                 ext4_rec_len_to_disk(rec_len, blocksize);
1115                 de->inode = 0;
1116                 map++;
1117                 to += rec_len;
1118         }
1119         return (struct ext4_dir_entry_2 *) (to - rec_len);
1120 }
1121
1122 /*
1123  * Compact each dir entry in the range to the minimal rec_len.
1124  * Returns pointer to last entry in range.
1125  */
1126 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize)
1127 {
1128         struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
1129         unsigned rec_len = 0;
1130
1131         prev = to = de;
1132         while ((char*)de < base + blocksize) {
1133                 next = ext4_next_entry(de, blocksize);
1134                 if (de->inode && de->name_len) {
1135                         rec_len = EXT4_DIR_REC_LEN(de->name_len);
1136                         if (de > to)
1137                                 memmove(to, de, rec_len);
1138                         to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
1139                         prev = to;
1140                         to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
1141                 }
1142                 de = next;
1143         }
1144         return prev;
1145 }
1146
1147 /*
1148  * Split a full leaf block to make room for a new dir entry.
1149  * Allocate a new block, and move entries so that they are approx. equally full.
1150  * Returns pointer to de in block into which the new entry will be inserted.
1151  */
1152 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
1153                         struct buffer_head **bh,struct dx_frame *frame,
1154                         struct dx_hash_info *hinfo, int *error)
1155 {
1156         unsigned blocksize = dir->i_sb->s_blocksize;
1157         unsigned count, continued;
1158         struct buffer_head *bh2;
1159         ext4_lblk_t newblock;
1160         u32 hash2;
1161         struct dx_map_entry *map;
1162         char *data1 = (*bh)->b_data, *data2;
1163         unsigned split, move, size;
1164         struct ext4_dir_entry_2 *de = NULL, *de2;
1165         int     err = 0, i;
1166
1167         bh2 = ext4_append (handle, dir, &newblock, &err);
1168         if (!(bh2)) {
1169                 brelse(*bh);
1170                 *bh = NULL;
1171                 goto errout;
1172         }
1173
1174         BUFFER_TRACE(*bh, "get_write_access");
1175         err = ext4_journal_get_write_access(handle, *bh);
1176         if (err)
1177                 goto journal_error;
1178
1179         BUFFER_TRACE(frame->bh, "get_write_access");
1180         err = ext4_journal_get_write_access(handle, frame->bh);
1181         if (err)
1182                 goto journal_error;
1183
1184         data2 = bh2->b_data;
1185
1186         /* create map in the end of data2 block */
1187         map = (struct dx_map_entry *) (data2 + blocksize);
1188         count = dx_make_map((struct ext4_dir_entry_2 *) data1,
1189                              blocksize, hinfo, map);
1190         map -= count;
1191         dx_sort_map(map, count);
1192         /* Split the existing block in the middle, size-wise */
1193         size = 0;
1194         move = 0;
1195         for (i = count-1; i >= 0; i--) {
1196                 /* is more than half of this entry in 2nd half of the block? */
1197                 if (size + map[i].size/2 > blocksize/2)
1198                         break;
1199                 size += map[i].size;
1200                 move++;
1201         }
1202         /* map index at which we will split */
1203         split = count - move;
1204         hash2 = map[split].hash;
1205         continued = hash2 == map[split - 1].hash;
1206         dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
1207                         (unsigned long)dx_get_block(frame->at),
1208                                         hash2, split, count-split));
1209
1210         /* Fancy dance to stay within two buffers */
1211         de2 = dx_move_dirents(data1, data2, map + split, count - split, blocksize);
1212         de = dx_pack_dirents(data1, blocksize);
1213         de->rec_len = ext4_rec_len_to_disk(data1 + blocksize - (char *) de,
1214                                            blocksize);
1215         de2->rec_len = ext4_rec_len_to_disk(data2 + blocksize - (char *) de2,
1216                                             blocksize);
1217         dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data1, blocksize, 1));
1218         dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data2, blocksize, 1));
1219
1220         /* Which block gets the new entry? */
1221         if (hinfo->hash >= hash2)
1222         {
1223                 swap(*bh, bh2);
1224                 de = de2;
1225         }
1226         dx_insert_block(frame, hash2 + continued, newblock);
1227         err = ext4_handle_dirty_metadata(handle, dir, bh2);
1228         if (err)
1229                 goto journal_error;
1230         err = ext4_handle_dirty_metadata(handle, dir, frame->bh);
1231         if (err)
1232                 goto journal_error;
1233         brelse(bh2);
1234         dxtrace(dx_show_index("frame", frame->entries));
1235         return de;
1236
1237 journal_error:
1238         brelse(*bh);
1239         brelse(bh2);
1240         *bh = NULL;
1241         ext4_std_error(dir->i_sb, err);
1242 errout:
1243         *error = err;
1244         return NULL;
1245 }
1246
1247 /*
1248  * Add a new entry into a directory (leaf) block.  If de is non-NULL,
1249  * it points to a directory entry which is guaranteed to be large
1250  * enough for new directory entry.  If de is NULL, then
1251  * add_dirent_to_buf will attempt search the directory block for
1252  * space.  It will return -ENOSPC if no space is available, and -EIO
1253  * and -EEXIST if directory entry already exists.
1254  */
1255 static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
1256                              struct inode *inode, struct ext4_dir_entry_2 *de,
1257                              struct buffer_head *bh)
1258 {
1259         struct inode    *dir = dentry->d_parent->d_inode;
1260         const char      *name = dentry->d_name.name;
1261         int             namelen = dentry->d_name.len;
1262         unsigned int    offset = 0;
1263         unsigned int    blocksize = dir->i_sb->s_blocksize;
1264         unsigned short  reclen;
1265         int             nlen, rlen, err;
1266         char            *top;
1267
1268         reclen = EXT4_DIR_REC_LEN(namelen);
1269         if (!de) {
1270                 de = (struct ext4_dir_entry_2 *)bh->b_data;
1271                 top = bh->b_data + blocksize - reclen;
1272                 while ((char *) de <= top) {
1273                         if (ext4_check_dir_entry(dir, NULL, de, bh, offset))
1274                                 return -EIO;
1275                         if (ext4_match(namelen, name, de))
1276                                 return -EEXIST;
1277                         nlen = EXT4_DIR_REC_LEN(de->name_len);
1278                         rlen = ext4_rec_len_from_disk(de->rec_len, blocksize);
1279                         if ((de->inode? rlen - nlen: rlen) >= reclen)
1280                                 break;
1281                         de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
1282                         offset += rlen;
1283                 }
1284                 if ((char *) de > top)
1285                         return -ENOSPC;
1286         }
1287         BUFFER_TRACE(bh, "get_write_access");
1288         err = ext4_journal_get_write_access(handle, bh);
1289         if (err) {
1290                 ext4_std_error(dir->i_sb, err);
1291                 return err;
1292         }
1293
1294         /* By now the buffer is marked for journaling */
1295         nlen = EXT4_DIR_REC_LEN(de->name_len);
1296         rlen = ext4_rec_len_from_disk(de->rec_len, blocksize);
1297         if (de->inode) {
1298                 struct ext4_dir_entry_2 *de1 = (struct ext4_dir_entry_2 *)((char *)de + nlen);
1299                 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, blocksize);
1300                 de->rec_len = ext4_rec_len_to_disk(nlen, blocksize);
1301                 de = de1;
1302         }
1303         de->file_type = EXT4_FT_UNKNOWN;
1304         if (inode) {
1305                 de->inode = cpu_to_le32(inode->i_ino);
1306                 ext4_set_de_type(dir->i_sb, de, inode->i_mode);
1307         } else
1308                 de->inode = 0;
1309         de->name_len = namelen;
1310         memcpy(de->name, name, namelen);
1311         /*
1312          * XXX shouldn't update any times until successful
1313          * completion of syscall, but too many callers depend
1314          * on this.
1315          *
1316          * XXX similarly, too many callers depend on
1317          * ext4_new_inode() setting the times, but error
1318          * recovery deletes the inode, so the worst that can
1319          * happen is that the times are slightly out of date
1320          * and/or different from the directory change time.
1321          */
1322         dir->i_mtime = dir->i_ctime = ext4_current_time(dir);
1323         ext4_update_dx_flag(dir);
1324         dir->i_version++;
1325         ext4_mark_inode_dirty(handle, dir);
1326         BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1327         err = ext4_handle_dirty_metadata(handle, dir, bh);
1328         if (err)
1329                 ext4_std_error(dir->i_sb, err);
1330         return 0;
1331 }
1332
1333 /*
1334  * This converts a one block unindexed directory to a 3 block indexed
1335  * directory, and adds the dentry to the indexed directory.
1336  */
1337 static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
1338                             struct inode *inode, struct buffer_head *bh)
1339 {
1340         struct inode    *dir = dentry->d_parent->d_inode;
1341         const char      *name = dentry->d_name.name;
1342         int             namelen = dentry->d_name.len;
1343         struct buffer_head *bh2;
1344         struct dx_root  *root;
1345         struct dx_frame frames[2], *frame;
1346         struct dx_entry *entries;
1347         struct ext4_dir_entry_2 *de, *de2;
1348         char            *data1, *top;
1349         unsigned        len;
1350         int             retval;
1351         unsigned        blocksize;
1352         struct dx_hash_info hinfo;
1353         ext4_lblk_t  block;
1354         struct fake_dirent *fde;
1355
1356         blocksize =  dir->i_sb->s_blocksize;
1357         dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
1358         retval = ext4_journal_get_write_access(handle, bh);
1359         if (retval) {
1360                 ext4_std_error(dir->i_sb, retval);
1361                 brelse(bh);
1362                 return retval;
1363         }
1364         root = (struct dx_root *) bh->b_data;
1365
1366         /* The 0th block becomes the root, move the dirents out */
1367         fde = &root->dotdot;
1368         de = (struct ext4_dir_entry_2 *)((char *)fde +
1369                 ext4_rec_len_from_disk(fde->rec_len, blocksize));
1370         if ((char *) de >= (((char *) root) + blocksize)) {
1371                 EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
1372                 brelse(bh);
1373                 return -EIO;
1374         }
1375         len = ((char *) root) + blocksize - (char *) de;
1376
1377         /* Allocate new block for the 0th block's dirents */
1378         bh2 = ext4_append(handle, dir, &block, &retval);
1379         if (!(bh2)) {
1380                 brelse(bh);
1381                 return retval;
1382         }
1383         ext4_set_inode_flag(dir, EXT4_INODE_INDEX);
1384         data1 = bh2->b_data;
1385
1386         memcpy (data1, de, len);
1387         de = (struct ext4_dir_entry_2 *) data1;
1388         top = data1 + len;
1389         while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
1390                 de = de2;
1391         de->rec_len = ext4_rec_len_to_disk(data1 + blocksize - (char *) de,
1392                                            blocksize);
1393         /* Initialize the root; the dot dirents already exist */
1394         de = (struct ext4_dir_entry_2 *) (&root->dotdot);
1395         de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
1396                                            blocksize);
1397         memset (&root->info, 0, sizeof(root->info));
1398         root->info.info_length = sizeof(root->info);
1399         root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
1400         entries = root->entries;
1401         dx_set_block(entries, 1);
1402         dx_set_count(entries, 1);
1403         dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
1404
1405         /* Initialize as for dx_probe */
1406         hinfo.hash_version = root->info.hash_version;
1407         if (hinfo.hash_version <= DX_HASH_TEA)
1408                 hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
1409         hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
1410         ext4fs_dirhash(name, namelen, &hinfo);
1411         frame = frames;
1412         frame->entries = entries;
1413         frame->at = entries;
1414         frame->bh = bh;
1415         bh = bh2;
1416
1417         ext4_handle_dirty_metadata(handle, dir, frame->bh);
1418         ext4_handle_dirty_metadata(handle, dir, bh);
1419
1420         de = do_split(handle,dir, &bh, frame, &hinfo, &retval);
1421         if (!de) {
1422                 /*
1423                  * Even if the block split failed, we have to properly write
1424                  * out all the changes we did so far. Otherwise we can end up
1425                  * with corrupted filesystem.
1426                  */
1427                 ext4_mark_inode_dirty(handle, dir);
1428                 dx_release(frames);
1429                 return retval;
1430         }
1431         dx_release(frames);
1432
1433         retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
1434         brelse(bh);
1435         return retval;
1436 }
1437
1438 /*
1439  *      ext4_add_entry()
1440  *
1441  * adds a file entry to the specified directory, using the same
1442  * semantics as ext4_find_entry(). It returns NULL if it failed.
1443  *
1444  * NOTE!! The inode part of 'de' is left at 0 - which means you
1445  * may not sleep between calling this and putting something into
1446  * the entry, as someone else might have used it while you slept.
1447  */
1448 static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
1449                           struct inode *inode)
1450 {
1451         struct inode *dir = dentry->d_parent->d_inode;
1452         struct buffer_head *bh;
1453         struct ext4_dir_entry_2 *de;
1454         struct super_block *sb;
1455         int     retval;
1456         int     dx_fallback=0;
1457         unsigned blocksize;
1458         ext4_lblk_t block, blocks;
1459
1460         sb = dir->i_sb;
1461         blocksize = sb->s_blocksize;
1462         if (!dentry->d_name.len)
1463                 return -EINVAL;
1464         if (is_dx(dir)) {
1465                 retval = ext4_dx_add_entry(handle, dentry, inode);
1466                 if (!retval || (retval != ERR_BAD_DX_DIR))
1467                         return retval;
1468                 ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
1469                 dx_fallback++;
1470                 ext4_mark_inode_dirty(handle, dir);
1471         }
1472         blocks = dir->i_size >> sb->s_blocksize_bits;
1473         for (block = 0; block < blocks; block++) {
1474                 bh = ext4_bread(handle, dir, block, 0, &retval);
1475                 if(!bh)
1476                         return retval;
1477                 retval = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
1478                 if (retval != -ENOSPC) {
1479                         brelse(bh);
1480                         return retval;
1481                 }
1482
1483                 if (blocks == 1 && !dx_fallback &&
1484                     EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX))
1485                         return make_indexed_dir(handle, dentry, inode, bh);
1486                 brelse(bh);
1487         }
1488         bh = ext4_append(handle, dir, &block, &retval);
1489         if (!bh)
1490                 return retval;
1491         de = (struct ext4_dir_entry_2 *) bh->b_data;
1492         de->inode = 0;
1493         de->rec_len = ext4_rec_len_to_disk(blocksize, blocksize);
1494         retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
1495         brelse(bh);
1496         if (retval == 0)
1497                 ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY);
1498         return retval;
1499 }
1500
1501 /*
1502  * Returns 0 for success, or a negative error value
1503  */
1504 static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
1505                              struct inode *inode)
1506 {
1507         struct dx_frame frames[2], *frame;
1508         struct dx_entry *entries, *at;
1509         struct dx_hash_info hinfo;
1510         struct buffer_head *bh;
1511         struct inode *dir = dentry->d_parent->d_inode;
1512         struct super_block *sb = dir->i_sb;
1513         struct ext4_dir_entry_2 *de;
1514         int err;
1515
1516         frame = dx_probe(&dentry->d_name, dir, &hinfo, frames, &err);
1517         if (!frame)
1518                 return err;
1519         entries = frame->entries;
1520         at = frame->at;
1521
1522         if (!(bh = ext4_bread(handle,dir, dx_get_block(frame->at), 0, &err)))
1523                 goto cleanup;
1524
1525         BUFFER_TRACE(bh, "get_write_access");
1526         err = ext4_journal_get_write_access(handle, bh);
1527         if (err)
1528                 goto journal_error;
1529
1530         err = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
1531         if (err != -ENOSPC)
1532                 goto cleanup;
1533
1534         /* Block full, should compress but for now just split */
1535         dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
1536                        dx_get_count(entries), dx_get_limit(entries)));
1537         /* Need to split index? */
1538         if (dx_get_count(entries) == dx_get_limit(entries)) {
1539                 ext4_lblk_t newblock;
1540                 unsigned icount = dx_get_count(entries);
1541                 int levels = frame - frames;
1542                 struct dx_entry *entries2;
1543                 struct dx_node *node2;
1544                 struct buffer_head *bh2;
1545
1546                 if (levels && (dx_get_count(frames->entries) ==
1547                                dx_get_limit(frames->entries))) {
1548                         ext4_warning(sb, "Directory index full!");
1549                         err = -ENOSPC;
1550                         goto cleanup;
1551                 }
1552                 bh2 = ext4_append (handle, dir, &newblock, &err);
1553                 if (!(bh2))
1554                         goto cleanup;
1555                 node2 = (struct dx_node *)(bh2->b_data);
1556                 entries2 = node2->entries;
1557                 memset(&node2->fake, 0, sizeof(struct fake_dirent));
1558                 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
1559                                                            sb->s_blocksize);
1560                 BUFFER_TRACE(frame->bh, "get_write_access");
1561                 err = ext4_journal_get_write_access(handle, frame->bh);
1562                 if (err)
1563                         goto journal_error;
1564                 if (levels) {
1565                         unsigned icount1 = icount/2, icount2 = icount - icount1;
1566                         unsigned hash2 = dx_get_hash(entries + icount1);
1567                         dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
1568                                        icount1, icount2));
1569
1570                         BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
1571                         err = ext4_journal_get_write_access(handle,
1572                                                              frames[0].bh);
1573                         if (err)
1574                                 goto journal_error;
1575
1576                         memcpy((char *) entries2, (char *) (entries + icount1),
1577                                icount2 * sizeof(struct dx_entry));
1578                         dx_set_count(entries, icount1);
1579                         dx_set_count(entries2, icount2);
1580                         dx_set_limit(entries2, dx_node_limit(dir));
1581
1582                         /* Which index block gets the new entry? */
1583                         if (at - entries >= icount1) {
1584                                 frame->at = at = at - entries - icount1 + entries2;
1585                                 frame->entries = entries = entries2;
1586                                 swap(frame->bh, bh2);
1587                         }
1588                         dx_insert_block(frames + 0, hash2, newblock);
1589                         dxtrace(dx_show_index("node", frames[1].entries));
1590                         dxtrace(dx_show_index("node",
1591                                ((struct dx_node *) bh2->b_data)->entries));
1592                         err = ext4_handle_dirty_metadata(handle, inode, bh2);
1593                         if (err)
1594                                 goto journal_error;
1595                         brelse (bh2);
1596                 } else {
1597                         dxtrace(printk(KERN_DEBUG
1598                                        "Creating second level index...\n"));
1599                         memcpy((char *) entries2, (char *) entries,
1600                                icount * sizeof(struct dx_entry));
1601                         dx_set_limit(entries2, dx_node_limit(dir));
1602
1603                         /* Set up root */
1604                         dx_set_count(entries, 1);
1605                         dx_set_block(entries + 0, newblock);
1606                         ((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels = 1;
1607
1608                         /* Add new access path frame */
1609                         frame = frames + 1;
1610                         frame->at = at = at - entries + entries2;
1611                         frame->entries = entries = entries2;
1612                         frame->bh = bh2;
1613                         err = ext4_journal_get_write_access(handle,
1614                                                              frame->bh);
1615                         if (err)
1616                                 goto journal_error;
1617                 }
1618                 err = ext4_handle_dirty_metadata(handle, inode, frames[0].bh);
1619                 if (err) {
1620                         ext4_std_error(inode->i_sb, err);
1621                         goto cleanup;
1622                 }
1623         }
1624         de = do_split(handle, dir, &bh, frame, &hinfo, &err);
1625         if (!de)
1626                 goto cleanup;
1627         err = add_dirent_to_buf(handle, dentry, inode, de, bh);
1628         goto cleanup;
1629
1630 journal_error:
1631         ext4_std_error(dir->i_sb, err);
1632 cleanup:
1633         if (bh)
1634                 brelse(bh);
1635         dx_release(frames);
1636         return err;
1637 }
1638
1639 /*
1640  * ext4_delete_entry deletes a directory entry by merging it with the
1641  * previous entry
1642  */
1643 static int ext4_delete_entry(handle_t *handle,
1644                              struct inode *dir,
1645                              struct ext4_dir_entry_2 *de_del,
1646                              struct buffer_head *bh)
1647 {
1648         struct ext4_dir_entry_2 *de, *pde;
1649         unsigned int blocksize = dir->i_sb->s_blocksize;
1650         int i, err;
1651
1652         i = 0;
1653         pde = NULL;
1654         de = (struct ext4_dir_entry_2 *) bh->b_data;
1655         while (i < bh->b_size) {
1656                 if (ext4_check_dir_entry(dir, NULL, de, bh, i))
1657                         return -EIO;
1658                 if (de == de_del)  {
1659                         BUFFER_TRACE(bh, "get_write_access");
1660                         err = ext4_journal_get_write_access(handle, bh);
1661                         if (unlikely(err)) {
1662                                 ext4_std_error(dir->i_sb, err);
1663                                 return err;
1664                         }
1665                         if (pde)
1666                                 pde->rec_len = ext4_rec_len_to_disk(
1667                                         ext4_rec_len_from_disk(pde->rec_len,
1668                                                                blocksize) +
1669                                         ext4_rec_len_from_disk(de->rec_len,
1670                                                                blocksize),
1671                                         blocksize);
1672                         else
1673                                 de->inode = 0;
1674                         dir->i_version++;
1675                         BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1676                         err = ext4_handle_dirty_metadata(handle, dir, bh);
1677                         if (unlikely(err)) {
1678                                 ext4_std_error(dir->i_sb, err);
1679                                 return err;
1680                         }
1681                         return 0;
1682                 }
1683                 i += ext4_rec_len_from_disk(de->rec_len, blocksize);
1684                 pde = de;
1685                 de = ext4_next_entry(de, blocksize);
1686         }
1687         return -ENOENT;
1688 }
1689
1690 /*
1691  * DIR_NLINK feature is set if 1) nlinks > EXT4_LINK_MAX or 2) nlinks == 2,
1692  * since this indicates that nlinks count was previously 1.
1693  */
1694 static void ext4_inc_count(handle_t *handle, struct inode *inode)
1695 {
1696         inc_nlink(inode);
1697         if (is_dx(inode) && inode->i_nlink > 1) {
1698                 /* limit is 16-bit i_links_count */
1699                 if (inode->i_nlink >= EXT4_LINK_MAX || inode->i_nlink == 2) {
1700                         inode->i_nlink = 1;
1701                         EXT4_SET_RO_COMPAT_FEATURE(inode->i_sb,
1702                                               EXT4_FEATURE_RO_COMPAT_DIR_NLINK);
1703                 }
1704         }
1705 }
1706
1707 /*
1708  * If a directory had nlink == 1, then we should let it be 1. This indicates
1709  * directory has >EXT4_LINK_MAX subdirs.
1710  */
1711 static void ext4_dec_count(handle_t *handle, struct inode *inode)
1712 {
1713         drop_nlink(inode);
1714         if (S_ISDIR(inode->i_mode) && inode->i_nlink == 0)
1715                 inc_nlink(inode);
1716 }
1717
1718
1719 static int ext4_add_nondir(handle_t *handle,
1720                 struct dentry *dentry, struct inode *inode)
1721 {
1722         int err = ext4_add_entry(handle, dentry, inode);
1723         if (!err) {
1724                 ext4_mark_inode_dirty(handle, inode);
1725                 d_instantiate(dentry, inode);
1726                 unlock_new_inode(inode);
1727                 return 0;
1728         }
1729         drop_nlink(inode);
1730         unlock_new_inode(inode);
1731         iput(inode);
1732         return err;
1733 }
1734
1735 /*
1736  * By the time this is called, we already have created
1737  * the directory cache entry for the new file, but it
1738  * is so far negative - it has no inode.
1739  *
1740  * If the create succeeds, we fill in the inode information
1741  * with d_instantiate().
1742  */
1743 static int ext4_create(struct inode *dir, struct dentry *dentry, int mode,
1744                        struct nameidata *nd)
1745 {
1746         handle_t *handle;
1747         struct inode *inode;
1748         int err, retries = 0;
1749
1750         dquot_initialize(dir);
1751
1752 retry:
1753         handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
1754                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
1755                                         EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
1756         if (IS_ERR(handle))
1757                 return PTR_ERR(handle);
1758
1759         if (IS_DIRSYNC(dir))
1760                 ext4_handle_sync(handle);
1761
1762         inode = ext4_new_inode(handle, dir, mode, &dentry->d_name, 0);
1763         err = PTR_ERR(inode);
1764         if (!IS_ERR(inode)) {
1765                 inode->i_op = &ext4_file_inode_operations;
1766                 inode->i_fop = &ext4_file_operations;
1767                 ext4_set_aops(inode);
1768                 err = ext4_add_nondir(handle, dentry, inode);
1769         }
1770         ext4_journal_stop(handle);
1771         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
1772                 goto retry;
1773         return err;
1774 }
1775
1776 static int ext4_mknod(struct inode *dir, struct dentry *dentry,
1777                       int mode, dev_t rdev)
1778 {
1779         handle_t *handle;
1780         struct inode *inode;
1781         int err, retries = 0;
1782
1783         if (!new_valid_dev(rdev))
1784                 return -EINVAL;
1785
1786         dquot_initialize(dir);
1787
1788 retry:
1789         handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
1790                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
1791                                         EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
1792         if (IS_ERR(handle))
1793                 return PTR_ERR(handle);
1794
1795         if (IS_DIRSYNC(dir))
1796                 ext4_handle_sync(handle);
1797
1798         inode = ext4_new_inode(handle, dir, mode, &dentry->d_name, 0);
1799         err = PTR_ERR(inode);
1800         if (!IS_ERR(inode)) {
1801                 init_special_inode(inode, inode->i_mode, rdev);
1802 #ifdef CONFIG_EXT4_FS_XATTR
1803                 inode->i_op = &ext4_special_inode_operations;
1804 #endif
1805                 err = ext4_add_nondir(handle, dentry, inode);
1806         }
1807         ext4_journal_stop(handle);
1808         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
1809                 goto retry;
1810         return err;
1811 }
1812
1813 static int ext4_mkdir(struct inode *dir, struct dentry *dentry, int mode)
1814 {
1815         handle_t *handle;
1816         struct inode *inode;
1817         struct buffer_head *dir_block = NULL;
1818         struct ext4_dir_entry_2 *de;
1819         unsigned int blocksize = dir->i_sb->s_blocksize;
1820         int err, retries = 0;
1821
1822         if (EXT4_DIR_LINK_MAX(dir))
1823                 return -EMLINK;
1824
1825         dquot_initialize(dir);
1826
1827 retry:
1828         handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
1829                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
1830                                         EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
1831         if (IS_ERR(handle))
1832                 return PTR_ERR(handle);
1833
1834         if (IS_DIRSYNC(dir))
1835                 ext4_handle_sync(handle);
1836
1837         inode = ext4_new_inode(handle, dir, S_IFDIR | mode,
1838                                &dentry->d_name, 0);
1839         err = PTR_ERR(inode);
1840         if (IS_ERR(inode))
1841                 goto out_stop;
1842
1843         inode->i_op = &ext4_dir_inode_operations;
1844         inode->i_fop = &ext4_dir_operations;
1845         inode->i_size = EXT4_I(inode)->i_disksize = inode->i_sb->s_blocksize;
1846         dir_block = ext4_bread(handle, inode, 0, 1, &err);
1847         if (!dir_block)
1848                 goto out_clear_inode;
1849         BUFFER_TRACE(dir_block, "get_write_access");
1850         err = ext4_journal_get_write_access(handle, dir_block);
1851         if (err)
1852                 goto out_clear_inode;
1853         de = (struct ext4_dir_entry_2 *) dir_block->b_data;
1854         de->inode = cpu_to_le32(inode->i_ino);
1855         de->name_len = 1;
1856         de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
1857                                            blocksize);
1858         strcpy(de->name, ".");
1859         ext4_set_de_type(dir->i_sb, de, S_IFDIR);
1860         de = ext4_next_entry(de, blocksize);
1861         de->inode = cpu_to_le32(dir->i_ino);
1862         de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(1),
1863                                            blocksize);
1864         de->name_len = 2;
1865         strcpy(de->name, "..");
1866         ext4_set_de_type(dir->i_sb, de, S_IFDIR);
1867         inode->i_nlink = 2;
1868         BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
1869         err = ext4_handle_dirty_metadata(handle, dir, dir_block);
1870         if (err)
1871                 goto out_clear_inode;
1872         err = ext4_mark_inode_dirty(handle, inode);
1873         if (!err)
1874                 err = ext4_add_entry(handle, dentry, inode);
1875         if (err) {
1876 out_clear_inode:
1877                 clear_nlink(inode);
1878                 unlock_new_inode(inode);
1879                 ext4_mark_inode_dirty(handle, inode);
1880                 iput(inode);
1881                 goto out_stop;
1882         }
1883         ext4_inc_count(handle, dir);
1884         ext4_update_dx_flag(dir);
1885         err = ext4_mark_inode_dirty(handle, dir);
1886         if (err)
1887                 goto out_clear_inode;
1888         d_instantiate(dentry, inode);
1889         unlock_new_inode(inode);
1890 out_stop:
1891         brelse(dir_block);
1892         ext4_journal_stop(handle);
1893         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
1894                 goto retry;
1895         return err;
1896 }
1897
1898 /*
1899  * routine to check that the specified directory is empty (for rmdir)
1900  */
1901 static int empty_dir(struct inode *inode)
1902 {
1903         unsigned int offset;
1904         struct buffer_head *bh;
1905         struct ext4_dir_entry_2 *de, *de1;
1906         struct super_block *sb;
1907         int err = 0;
1908
1909         sb = inode->i_sb;
1910         if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2) ||
1911             !(bh = ext4_bread(NULL, inode, 0, 0, &err))) {
1912                 if (err)
1913                         EXT4_ERROR_INODE(inode,
1914                                 "error %d reading directory lblock 0", err);
1915                 else
1916                         ext4_warning(inode->i_sb,
1917                                      "bad directory (dir #%lu) - no data block",
1918                                      inode->i_ino);
1919                 return 1;
1920         }
1921         de = (struct ext4_dir_entry_2 *) bh->b_data;
1922         de1 = ext4_next_entry(de, sb->s_blocksize);
1923         if (le32_to_cpu(de->inode) != inode->i_ino ||
1924                         !le32_to_cpu(de1->inode) ||
1925                         strcmp(".", de->name) ||
1926                         strcmp("..", de1->name)) {
1927                 ext4_warning(inode->i_sb,
1928                              "bad directory (dir #%lu) - no `.' or `..'",
1929                              inode->i_ino);
1930                 brelse(bh);
1931                 return 1;
1932         }
1933         offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) +
1934                  ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize);
1935         de = ext4_next_entry(de1, sb->s_blocksize);
1936         while (offset < inode->i_size) {
1937                 if (!bh ||
1938                     (void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
1939                         unsigned int lblock;
1940                         err = 0;
1941                         brelse(bh);
1942                         lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb);
1943                         bh = ext4_bread(NULL, inode, lblock, 0, &err);
1944                         if (!bh) {
1945                                 if (err)
1946                                         EXT4_ERROR_INODE(inode,
1947                                                 "error %d reading directory "
1948                                                 "lblock %u", err, lblock);
1949                                 offset += sb->s_blocksize;
1950                                 continue;
1951                         }
1952                         de = (struct ext4_dir_entry_2 *) bh->b_data;
1953                 }
1954                 if (ext4_check_dir_entry(inode, NULL, de, bh, offset)) {
1955                         de = (struct ext4_dir_entry_2 *)(bh->b_data +
1956                                                          sb->s_blocksize);
1957                         offset = (offset | (sb->s_blocksize - 1)) + 1;
1958                         continue;
1959                 }
1960                 if (le32_to_cpu(de->inode)) {
1961                         brelse(bh);
1962                         return 0;
1963                 }
1964                 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
1965                 de = ext4_next_entry(de, sb->s_blocksize);
1966         }
1967         brelse(bh);
1968         return 1;
1969 }
1970
1971 /* ext4_orphan_add() links an unlinked or truncated inode into a list of
1972  * such inodes, starting at the superblock, in case we crash before the
1973  * file is closed/deleted, or in case the inode truncate spans multiple
1974  * transactions and the last transaction is not recovered after a crash.
1975  *
1976  * At filesystem recovery time, we walk this list deleting unlinked
1977  * inodes and truncating linked inodes in ext4_orphan_cleanup().
1978  */
1979 int ext4_orphan_add(handle_t *handle, struct inode *inode)
1980 {
1981         struct super_block *sb = inode->i_sb;
1982         struct ext4_iloc iloc;
1983         int err = 0, rc;
1984
1985         if (!ext4_handle_valid(handle))
1986                 return 0;
1987
1988         mutex_lock(&EXT4_SB(sb)->s_orphan_lock);
1989         if (!list_empty(&EXT4_I(inode)->i_orphan))
1990                 goto out_unlock;
1991
1992         /* Orphan handling is only valid for files with data blocks
1993          * being truncated, or files being unlinked. */
1994
1995         /* @@@ FIXME: Observation from aviro:
1996          * I think I can trigger J_ASSERT in ext4_orphan_add().  We block
1997          * here (on s_orphan_lock), so race with ext4_link() which might bump
1998          * ->i_nlink. For, say it, character device. Not a regular file,
1999          * not a directory, not a symlink and ->i_nlink > 0.
2000          *
2001          * tytso, 4/25/2009: I'm not sure how that could happen;
2002          * shouldn't the fs core protect us from these sort of
2003          * unlink()/link() races?
2004          */
2005         J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2006                   S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
2007
2008         BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access");
2009         err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
2010         if (err)
2011                 goto out_unlock;
2012
2013         err = ext4_reserve_inode_write(handle, inode, &iloc);
2014         if (err)
2015                 goto out_unlock;
2016         /*
2017          * Due to previous errors inode may be already a part of on-disk
2018          * orphan list. If so skip on-disk list modification.
2019          */
2020         if (NEXT_ORPHAN(inode) && NEXT_ORPHAN(inode) <=
2021                 (le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count)))
2022                         goto mem_insert;
2023
2024         /* Insert this inode at the head of the on-disk orphan list... */
2025         NEXT_ORPHAN(inode) = le32_to_cpu(EXT4_SB(sb)->s_es->s_last_orphan);
2026         EXT4_SB(sb)->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
2027         err = ext4_handle_dirty_metadata(handle, NULL, EXT4_SB(sb)->s_sbh);
2028         rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
2029         if (!err)
2030                 err = rc;
2031
2032         /* Only add to the head of the in-memory list if all the
2033          * previous operations succeeded.  If the orphan_add is going to
2034          * fail (possibly taking the journal offline), we can't risk
2035          * leaving the inode on the orphan list: stray orphan-list
2036          * entries can cause panics at unmount time.
2037          *
2038          * This is safe: on error we're going to ignore the orphan list
2039          * anyway on the next recovery. */
2040 mem_insert:
2041         if (!err)
2042                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2043
2044         jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
2045         jbd_debug(4, "orphan inode %lu will point to %d\n",
2046                         inode->i_ino, NEXT_ORPHAN(inode));
2047 out_unlock:
2048         mutex_unlock(&EXT4_SB(sb)->s_orphan_lock);
2049         ext4_std_error(inode->i_sb, err);
2050         return err;
2051 }
2052
2053 /*
2054  * ext4_orphan_del() removes an unlinked or truncated inode from the list
2055  * of such inodes stored on disk, because it is finally being cleaned up.
2056  */
2057 int ext4_orphan_del(handle_t *handle, struct inode *inode)
2058 {
2059         struct list_head *prev;
2060         struct ext4_inode_info *ei = EXT4_I(inode);
2061         struct ext4_sb_info *sbi;
2062         __u32 ino_next;
2063         struct ext4_iloc iloc;
2064         int err = 0;
2065
2066         /* ext4_handle_valid() assumes a valid handle_t pointer */
2067         if (handle && !ext4_handle_valid(handle))
2068                 return 0;
2069
2070         mutex_lock(&EXT4_SB(inode->i_sb)->s_orphan_lock);
2071         if (list_empty(&ei->i_orphan))
2072                 goto out;
2073
2074         ino_next = NEXT_ORPHAN(inode);
2075         prev = ei->i_orphan.prev;
2076         sbi = EXT4_SB(inode->i_sb);
2077
2078         jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
2079
2080         list_del_init(&ei->i_orphan);
2081
2082         /* If we're on an error path, we may not have a valid
2083          * transaction handle with which to update the orphan list on
2084          * disk, but we still need to remove the inode from the linked
2085          * list in memory. */
2086         if (sbi->s_journal && !handle)
2087                 goto out;
2088
2089         err = ext4_reserve_inode_write(handle, inode, &iloc);
2090         if (err)
2091                 goto out_err;
2092
2093         if (prev == &sbi->s_orphan) {
2094                 jbd_debug(4, "superblock will point to %u\n", ino_next);
2095                 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2096                 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2097                 if (err)
2098                         goto out_brelse;
2099                 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
2100                 err = ext4_handle_dirty_metadata(handle, NULL, sbi->s_sbh);
2101         } else {
2102                 struct ext4_iloc iloc2;
2103                 struct inode *i_prev =
2104                         &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
2105
2106                 jbd_debug(4, "orphan inode %lu will point to %u\n",
2107                           i_prev->i_ino, ino_next);
2108                 err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
2109                 if (err)
2110                         goto out_brelse;
2111                 NEXT_ORPHAN(i_prev) = ino_next;
2112                 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
2113         }
2114         if (err)
2115                 goto out_brelse;
2116         NEXT_ORPHAN(inode) = 0;
2117         err = ext4_mark_iloc_dirty(handle, inode, &iloc);
2118
2119 out_err:
2120         ext4_std_error(inode->i_sb, err);
2121 out:
2122         mutex_unlock(&EXT4_SB(inode->i_sb)->s_orphan_lock);
2123         return err;
2124
2125 out_brelse:
2126         brelse(iloc.bh);
2127         goto out_err;
2128 }
2129
2130 static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
2131 {
2132         int retval;
2133         struct inode *inode;
2134         struct buffer_head *bh;
2135         struct ext4_dir_entry_2 *de;
2136         handle_t *handle;
2137
2138         /* Initialize quotas before so that eventual writes go in
2139          * separate transaction */
2140         dquot_initialize(dir);
2141         dquot_initialize(dentry->d_inode);
2142
2143         handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb));
2144         if (IS_ERR(handle))
2145                 return PTR_ERR(handle);
2146
2147         retval = -ENOENT;
2148         bh = ext4_find_entry(dir, &dentry->d_name, &de);
2149         if (!bh)
2150                 goto end_rmdir;
2151
2152         if (IS_DIRSYNC(dir))
2153                 ext4_handle_sync(handle);
2154
2155         inode = dentry->d_inode;
2156
2157         retval = -EIO;
2158         if (le32_to_cpu(de->inode) != inode->i_ino)
2159                 goto end_rmdir;
2160
2161         retval = -ENOTEMPTY;
2162         if (!empty_dir(inode))
2163                 goto end_rmdir;
2164
2165         retval = ext4_delete_entry(handle, dir, de, bh);
2166         if (retval)
2167                 goto end_rmdir;
2168         if (!EXT4_DIR_LINK_EMPTY(inode))
2169                 ext4_warning(inode->i_sb,
2170                              "empty directory has too many links (%d)",
2171                              inode->i_nlink);
2172         inode->i_version++;
2173         clear_nlink(inode);
2174         /* There's no need to set i_disksize: the fact that i_nlink is
2175          * zero will ensure that the right thing happens during any
2176          * recovery. */
2177         inode->i_size = 0;
2178         ext4_orphan_add(handle, inode);
2179         inode->i_ctime = dir->i_ctime = dir->i_mtime = ext4_current_time(inode);
2180         ext4_mark_inode_dirty(handle, inode);
2181         ext4_dec_count(handle, dir);
2182         ext4_update_dx_flag(dir);
2183         ext4_mark_inode_dirty(handle, dir);
2184
2185 end_rmdir:
2186         ext4_journal_stop(handle);
2187         brelse(bh);
2188         return retval;
2189 }
2190
2191 static int ext4_unlink(struct inode *dir, struct dentry *dentry)
2192 {
2193         int retval;
2194         struct inode *inode;
2195         struct buffer_head *bh;
2196         struct ext4_dir_entry_2 *de;
2197         handle_t *handle;
2198
2199         trace_ext4_unlink_enter(dir, dentry);
2200         /* Initialize quotas before so that eventual writes go
2201          * in separate transaction */
2202         dquot_initialize(dir);
2203         dquot_initialize(dentry->d_inode);
2204
2205         handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb));
2206         if (IS_ERR(handle))
2207                 return PTR_ERR(handle);
2208
2209         if (IS_DIRSYNC(dir))
2210                 ext4_handle_sync(handle);
2211
2212         retval = -ENOENT;
2213         bh = ext4_find_entry(dir, &dentry->d_name, &de);
2214         if (!bh)
2215                 goto end_unlink;
2216
2217         inode = dentry->d_inode;
2218
2219         retval = -EIO;
2220         if (le32_to_cpu(de->inode) != inode->i_ino)
2221                 goto end_unlink;
2222
2223         if (!inode->i_nlink) {
2224                 ext4_warning(inode->i_sb,
2225                              "Deleting nonexistent file (%lu), %d",
2226                              inode->i_ino, inode->i_nlink);
2227                 inode->i_nlink = 1;
2228         }
2229         retval = ext4_delete_entry(handle, dir, de, bh);
2230         if (retval)
2231                 goto end_unlink;
2232         dir->i_ctime = dir->i_mtime = ext4_current_time(dir);
2233         ext4_update_dx_flag(dir);
2234         ext4_mark_inode_dirty(handle, dir);
2235         drop_nlink(inode);
2236         if (!inode->i_nlink)
2237                 ext4_orphan_add(handle, inode);
2238         inode->i_ctime = ext4_current_time(inode);
2239         ext4_mark_inode_dirty(handle, inode);
2240         retval = 0;
2241
2242 end_unlink:
2243         ext4_journal_stop(handle);
2244         brelse(bh);
2245         trace_ext4_unlink_exit(dentry, retval);
2246         return retval;
2247 }
2248
2249 static int ext4_symlink(struct inode *dir,
2250                         struct dentry *dentry, const char *symname)
2251 {
2252         handle_t *handle;
2253         struct inode *inode;
2254         int l, err, retries = 0;
2255         int credits;
2256
2257         l = strlen(symname)+1;
2258         if (l > dir->i_sb->s_blocksize)
2259                 return -ENAMETOOLONG;
2260
2261         dquot_initialize(dir);
2262
2263         if (l > EXT4_N_BLOCKS * 4) {
2264                 /*
2265                  * For non-fast symlinks, we just allocate inode and put it on
2266                  * orphan list in the first transaction => we need bitmap,
2267                  * group descriptor, sb, inode block, quota blocks.
2268                  */
2269                 credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb);
2270         } else {
2271                 /*
2272                  * Fast symlink. We have to add entry to directory
2273                  * (EXT4_DATA_TRANS_BLOCKS + EXT4_INDEX_EXTRA_TRANS_BLOCKS),
2274                  * allocate new inode (bitmap, group descriptor, inode block,
2275                  * quota blocks, sb is already counted in previous macros).
2276                  */
2277                 credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2278                           EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
2279                           EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb);
2280         }
2281 retry:
2282         handle = ext4_journal_start(dir, credits);
2283         if (IS_ERR(handle))
2284                 return PTR_ERR(handle);
2285
2286         if (IS_DIRSYNC(dir))
2287                 ext4_handle_sync(handle);
2288
2289         inode = ext4_new_inode(handle, dir, S_IFLNK|S_IRWXUGO,
2290                                &dentry->d_name, 0);
2291         err = PTR_ERR(inode);
2292         if (IS_ERR(inode))
2293                 goto out_stop;
2294
2295         if (l > EXT4_N_BLOCKS * 4) {
2296                 inode->i_op = &ext4_symlink_inode_operations;
2297                 ext4_set_aops(inode);
2298                 /*
2299                  * We cannot call page_symlink() with transaction started
2300                  * because it calls into ext4_write_begin() which can wait
2301                  * for transaction commit if we are running out of space
2302                  * and thus we deadlock. So we have to stop transaction now
2303                  * and restart it when symlink contents is written.
2304                  * 
2305                  * To keep fs consistent in case of crash, we have to put inode
2306                  * to orphan list in the mean time.
2307                  */
2308                 drop_nlink(inode);
2309                 err = ext4_orphan_add(handle, inode);
2310                 ext4_journal_stop(handle);
2311                 if (err)
2312                         goto err_drop_inode;
2313                 err = __page_symlink(inode, symname, l, 1);
2314                 if (err)
2315                         goto err_drop_inode;
2316                 /*
2317                  * Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS
2318                  * + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified
2319                  */
2320                 handle = ext4_journal_start(dir,
2321                                 EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2322                                 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1);
2323                 if (IS_ERR(handle)) {
2324                         err = PTR_ERR(handle);
2325                         goto err_drop_inode;
2326                 }
2327                 inc_nlink(inode);
2328                 err = ext4_orphan_del(handle, inode);
2329                 if (err) {
2330                         ext4_journal_stop(handle);
2331                         clear_nlink(inode);
2332                         goto err_drop_inode;
2333                 }
2334         } else {
2335                 /* clear the extent format for fast symlink */
2336                 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
2337                 inode->i_op = &ext4_fast_symlink_inode_operations;
2338                 memcpy((char *)&EXT4_I(inode)->i_data, symname, l);
2339                 inode->i_size = l-1;
2340         }
2341         EXT4_I(inode)->i_disksize = inode->i_size;
2342         err = ext4_add_nondir(handle, dentry, inode);
2343 out_stop:
2344         ext4_journal_stop(handle);
2345         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2346                 goto retry;
2347         return err;
2348 err_drop_inode:
2349         unlock_new_inode(inode);
2350         iput(inode);
2351         return err;
2352 }
2353
2354 static int ext4_link(struct dentry *old_dentry,
2355                      struct inode *dir, struct dentry *dentry)
2356 {
2357         handle_t *handle;
2358         struct inode *inode = old_dentry->d_inode;
2359         int err, retries = 0;
2360
2361         if (inode->i_nlink >= EXT4_LINK_MAX)
2362                 return -EMLINK;
2363
2364         dquot_initialize(dir);
2365
2366 retry:
2367         handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2368                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS);
2369         if (IS_ERR(handle))
2370                 return PTR_ERR(handle);
2371
2372         if (IS_DIRSYNC(dir))
2373                 ext4_handle_sync(handle);
2374
2375         inode->i_ctime = ext4_current_time(inode);
2376         ext4_inc_count(handle, inode);
2377         ihold(inode);
2378
2379         err = ext4_add_entry(handle, dentry, inode);
2380         if (!err) {
2381                 ext4_mark_inode_dirty(handle, inode);
2382                 d_instantiate(dentry, inode);
2383         } else {
2384                 drop_nlink(inode);
2385                 iput(inode);
2386         }
2387         ext4_journal_stop(handle);
2388         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2389                 goto retry;
2390         return err;
2391 }
2392
2393 #define PARENT_INO(buffer, size) \
2394         (ext4_next_entry((struct ext4_dir_entry_2 *)(buffer), size)->inode)
2395
2396 /*
2397  * Anybody can rename anything with this: the permission checks are left to the
2398  * higher-level routines.
2399  */
2400 static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
2401                        struct inode *new_dir, struct dentry *new_dentry)
2402 {
2403         handle_t *handle;
2404         struct inode *old_inode, *new_inode;
2405         struct buffer_head *old_bh, *new_bh, *dir_bh;
2406         struct ext4_dir_entry_2 *old_de, *new_de;
2407         int retval, force_da_alloc = 0;
2408
2409         dquot_initialize(old_dir);
2410         dquot_initialize(new_dir);
2411
2412         old_bh = new_bh = dir_bh = NULL;
2413
2414         /* Initialize quotas before so that eventual writes go
2415          * in separate transaction */
2416         if (new_dentry->d_inode)
2417                 dquot_initialize(new_dentry->d_inode);
2418         handle = ext4_journal_start(old_dir, 2 *
2419                                         EXT4_DATA_TRANS_BLOCKS(old_dir->i_sb) +
2420                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
2421         if (IS_ERR(handle))
2422                 return PTR_ERR(handle);
2423
2424         if (IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir))
2425                 ext4_handle_sync(handle);
2426
2427         old_bh = ext4_find_entry(old_dir, &old_dentry->d_name, &old_de);
2428         /*
2429          *  Check for inode number is _not_ due to possible IO errors.
2430          *  We might rmdir the source, keep it as pwd of some process
2431          *  and merrily kill the link to whatever was created under the
2432          *  same name. Goodbye sticky bit ;-<
2433          */
2434         old_inode = old_dentry->d_inode;
2435         retval = -ENOENT;
2436         if (!old_bh || le32_to_cpu(old_de->inode) != old_inode->i_ino)
2437                 goto end_rename;
2438
2439         new_inode = new_dentry->d_inode;
2440         new_bh = ext4_find_entry(new_dir, &new_dentry->d_name, &new_de);
2441         if (new_bh) {
2442                 if (!new_inode) {
2443                         brelse(new_bh);
2444                         new_bh = NULL;
2445                 }
2446         }
2447         if (S_ISDIR(old_inode->i_mode)) {
2448                 if (new_inode) {
2449                         retval = -ENOTEMPTY;
2450                         if (!empty_dir(new_inode))
2451                                 goto end_rename;
2452                 }
2453                 retval = -EIO;
2454                 dir_bh = ext4_bread(handle, old_inode, 0, 0, &retval);
2455                 if (!dir_bh)
2456                         goto end_rename;
2457                 if (le32_to_cpu(PARENT_INO(dir_bh->b_data,
2458                                 old_dir->i_sb->s_blocksize)) != old_dir->i_ino)
2459                         goto end_rename;
2460                 retval = -EMLINK;
2461                 if (!new_inode && new_dir != old_dir &&
2462                     EXT4_DIR_LINK_MAX(new_dir))
2463                         goto end_rename;
2464                 BUFFER_TRACE(dir_bh, "get_write_access");
2465                 retval = ext4_journal_get_write_access(handle, dir_bh);
2466                 if (retval)
2467                         goto end_rename;
2468         }
2469         if (!new_bh) {
2470                 retval = ext4_add_entry(handle, new_dentry, old_inode);
2471                 if (retval)
2472                         goto end_rename;
2473         } else {
2474                 BUFFER_TRACE(new_bh, "get write access");
2475                 retval = ext4_journal_get_write_access(handle, new_bh);
2476                 if (retval)
2477                         goto end_rename;
2478                 new_de->inode = cpu_to_le32(old_inode->i_ino);
2479                 if (EXT4_HAS_INCOMPAT_FEATURE(new_dir->i_sb,
2480                                               EXT4_FEATURE_INCOMPAT_FILETYPE))
2481                         new_de->file_type = old_de->file_type;
2482                 new_dir->i_version++;
2483                 new_dir->i_ctime = new_dir->i_mtime =
2484                                         ext4_current_time(new_dir);
2485                 ext4_mark_inode_dirty(handle, new_dir);
2486                 BUFFER_TRACE(new_bh, "call ext4_handle_dirty_metadata");
2487                 retval = ext4_handle_dirty_metadata(handle, new_dir, new_bh);
2488                 if (unlikely(retval)) {
2489                         ext4_std_error(new_dir->i_sb, retval);
2490                         goto end_rename;
2491                 }
2492                 brelse(new_bh);
2493                 new_bh = NULL;
2494         }
2495
2496         /*
2497          * Like most other Unix systems, set the ctime for inodes on a
2498          * rename.
2499          */
2500         old_inode->i_ctime = ext4_current_time(old_inode);
2501         ext4_mark_inode_dirty(handle, old_inode);
2502
2503         /*
2504          * ok, that's it
2505          */
2506         if (le32_to_cpu(old_de->inode) != old_inode->i_ino ||
2507             old_de->name_len != old_dentry->d_name.len ||
2508             strncmp(old_de->name, old_dentry->d_name.name, old_de->name_len) ||
2509             (retval = ext4_delete_entry(handle, old_dir,
2510                                         old_de, old_bh)) == -ENOENT) {
2511                 /* old_de could have moved from under us during htree split, so
2512                  * make sure that we are deleting the right entry.  We might
2513                  * also be pointing to a stale entry in the unused part of
2514                  * old_bh so just checking inum and the name isn't enough. */
2515                 struct buffer_head *old_bh2;
2516                 struct ext4_dir_entry_2 *old_de2;
2517
2518                 old_bh2 = ext4_find_entry(old_dir, &old_dentry->d_name, &old_de2);
2519                 if (old_bh2) {
2520                         retval = ext4_delete_entry(handle, old_dir,
2521                                                    old_de2, old_bh2);
2522                         brelse(old_bh2);
2523                 }
2524         }
2525         if (retval) {
2526                 ext4_warning(old_dir->i_sb,
2527                                 "Deleting old file (%lu), %d, error=%d",
2528                                 old_dir->i_ino, old_dir->i_nlink, retval);
2529         }
2530
2531         if (new_inode) {
2532                 ext4_dec_count(handle, new_inode);
2533                 new_inode->i_ctime = ext4_current_time(new_inode);
2534         }
2535         old_dir->i_ctime = old_dir->i_mtime = ext4_current_time(old_dir);
2536         ext4_update_dx_flag(old_dir);
2537         if (dir_bh) {
2538                 PARENT_INO(dir_bh->b_data, new_dir->i_sb->s_blocksize) =
2539                                                 cpu_to_le32(new_dir->i_ino);
2540                 BUFFER_TRACE(dir_bh, "call ext4_handle_dirty_metadata");
2541                 retval = ext4_handle_dirty_metadata(handle, old_dir, dir_bh);
2542                 if (retval) {
2543                         ext4_std_error(old_dir->i_sb, retval);
2544                         goto end_rename;
2545                 }
2546                 ext4_dec_count(handle, old_dir);
2547                 if (new_inode) {
2548                         /* checked empty_dir above, can't have another parent,
2549                          * ext4_dec_count() won't work for many-linked dirs */
2550                         new_inode->i_nlink = 0;
2551                 } else {
2552                         ext4_inc_count(handle, new_dir);
2553                         ext4_update_dx_flag(new_dir);
2554                         ext4_mark_inode_dirty(handle, new_dir);
2555                 }
2556         }
2557         ext4_mark_inode_dirty(handle, old_dir);
2558         if (new_inode) {
2559                 ext4_mark_inode_dirty(handle, new_inode);
2560                 if (!new_inode->i_nlink)
2561                         ext4_orphan_add(handle, new_inode);
2562                 if (!test_opt(new_dir->i_sb, NO_AUTO_DA_ALLOC))
2563                         force_da_alloc = 1;
2564         }
2565         retval = 0;
2566
2567 end_rename:
2568         brelse(dir_bh);
2569         brelse(old_bh);
2570         brelse(new_bh);
2571         ext4_journal_stop(handle);
2572         if (retval == 0 && force_da_alloc)
2573                 ext4_alloc_da_blocks(old_inode);
2574         return retval;
2575 }
2576
2577 /*
2578  * directories can handle most operations...
2579  */
2580 const struct inode_operations ext4_dir_inode_operations = {
2581         .create         = ext4_create,
2582         .lookup         = ext4_lookup,
2583         .link           = ext4_link,
2584         .unlink         = ext4_unlink,
2585         .symlink        = ext4_symlink,
2586         .mkdir          = ext4_mkdir,
2587         .rmdir          = ext4_rmdir,
2588         .mknod          = ext4_mknod,
2589         .rename         = ext4_rename,
2590         .setattr        = ext4_setattr,
2591 #ifdef CONFIG_EXT4_FS_XATTR
2592         .setxattr       = generic_setxattr,
2593         .getxattr       = generic_getxattr,
2594         .listxattr      = ext4_listxattr,
2595         .removexattr    = generic_removexattr,
2596 #endif
2597         .check_acl      = ext4_check_acl,
2598         .fiemap         = ext4_fiemap,
2599 };
2600
2601 const struct inode_operations ext4_special_inode_operations = {
2602         .setattr        = ext4_setattr,
2603 #ifdef CONFIG_EXT4_FS_XATTR
2604         .setxattr       = generic_setxattr,
2605         .getxattr       = generic_getxattr,
2606         .listxattr      = ext4_listxattr,
2607         .removexattr    = generic_removexattr,
2608 #endif
2609         .check_acl      = ext4_check_acl,
2610 };