Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
[sfrench/cifs-2.6.git] / fs / ext4 / namei.c
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  linux/fs/ext4/namei.c
4  *
5  * Copyright (C) 1992, 1993, 1994, 1995
6  * Remy Card (card@masi.ibp.fr)
7  * Laboratoire MASI - Institut Blaise Pascal
8  * Universite Pierre et Marie Curie (Paris VI)
9  *
10  *  from
11  *
12  *  linux/fs/minix/namei.c
13  *
14  *  Copyright (C) 1991, 1992  Linus Torvalds
15  *
16  *  Big-endian to little-endian byte-swapping/bitmaps by
17  *        David S. Miller (davem@caip.rutgers.edu), 1995
18  *  Directory entry file type support and forward compatibility hooks
19  *      for B-tree directories by Theodore Ts'o (tytso@mit.edu), 1998
20  *  Hash Tree Directory indexing (c)
21  *      Daniel Phillips, 2001
22  *  Hash Tree Directory indexing porting
23  *      Christopher Li, 2002
24  *  Hash Tree Directory indexing cleanup
25  *      Theodore Ts'o, 2002
26  */
27
28 #include <linux/fs.h>
29 #include <linux/pagemap.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 <linux/iversion.h>
38 #include "ext4.h"
39 #include "ext4_jbd2.h"
40
41 #include "xattr.h"
42 #include "acl.h"
43
44 #include <trace/events/ext4.h>
45 /*
46  * define how far ahead to read directories while searching them.
47  */
48 #define NAMEI_RA_CHUNKS  2
49 #define NAMEI_RA_BLOCKS  4
50 #define NAMEI_RA_SIZE        (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS)
51
52 static struct buffer_head *ext4_append(handle_t *handle,
53                                         struct inode *inode,
54                                         ext4_lblk_t *block)
55 {
56         struct buffer_head *bh;
57         int err;
58
59         if (unlikely(EXT4_SB(inode->i_sb)->s_max_dir_size_kb &&
60                      ((inode->i_size >> 10) >=
61                       EXT4_SB(inode->i_sb)->s_max_dir_size_kb)))
62                 return ERR_PTR(-ENOSPC);
63
64         *block = inode->i_size >> inode->i_sb->s_blocksize_bits;
65
66         bh = ext4_bread(handle, inode, *block, EXT4_GET_BLOCKS_CREATE);
67         if (IS_ERR(bh))
68                 return bh;
69         inode->i_size += inode->i_sb->s_blocksize;
70         EXT4_I(inode)->i_disksize = inode->i_size;
71         BUFFER_TRACE(bh, "get_write_access");
72         err = ext4_journal_get_write_access(handle, bh);
73         if (err) {
74                 brelse(bh);
75                 ext4_std_error(inode->i_sb, err);
76                 return ERR_PTR(err);
77         }
78         return bh;
79 }
80
81 static int ext4_dx_csum_verify(struct inode *inode,
82                                struct ext4_dir_entry *dirent);
83
84 typedef enum {
85         EITHER, INDEX, DIRENT
86 } dirblock_type_t;
87
88 #define ext4_read_dirblock(inode, block, type) \
89         __ext4_read_dirblock((inode), (block), (type), __func__, __LINE__)
90
91 static struct buffer_head *__ext4_read_dirblock(struct inode *inode,
92                                                 ext4_lblk_t block,
93                                                 dirblock_type_t type,
94                                                 const char *func,
95                                                 unsigned int line)
96 {
97         struct buffer_head *bh;
98         struct ext4_dir_entry *dirent;
99         int is_dx_block = 0;
100
101         bh = ext4_bread(NULL, inode, block, 0);
102         if (IS_ERR(bh)) {
103                 __ext4_warning(inode->i_sb, func, line,
104                                "inode #%lu: lblock %lu: comm %s: "
105                                "error %ld reading directory block",
106                                inode->i_ino, (unsigned long)block,
107                                current->comm, PTR_ERR(bh));
108
109                 return bh;
110         }
111         if (!bh) {
112                 ext4_error_inode(inode, func, line, block,
113                                  "Directory hole found");
114                 return ERR_PTR(-EFSCORRUPTED);
115         }
116         dirent = (struct ext4_dir_entry *) bh->b_data;
117         /* Determine whether or not we have an index block */
118         if (is_dx(inode)) {
119                 if (block == 0)
120                         is_dx_block = 1;
121                 else if (ext4_rec_len_from_disk(dirent->rec_len,
122                                                 inode->i_sb->s_blocksize) ==
123                          inode->i_sb->s_blocksize)
124                         is_dx_block = 1;
125         }
126         if (!is_dx_block && type == INDEX) {
127                 ext4_error_inode(inode, func, line, block,
128                        "directory leaf block found instead of index block");
129                 return ERR_PTR(-EFSCORRUPTED);
130         }
131         if (!ext4_has_metadata_csum(inode->i_sb) ||
132             buffer_verified(bh))
133                 return bh;
134
135         /*
136          * An empty leaf block can get mistaken for a index block; for
137          * this reason, we can only check the index checksum when the
138          * caller is sure it should be an index block.
139          */
140         if (is_dx_block && type == INDEX) {
141                 if (ext4_dx_csum_verify(inode, dirent))
142                         set_buffer_verified(bh);
143                 else {
144                         ext4_error_inode(inode, func, line, block,
145                                          "Directory index failed checksum");
146                         brelse(bh);
147                         return ERR_PTR(-EFSBADCRC);
148                 }
149         }
150         if (!is_dx_block) {
151                 if (ext4_dirent_csum_verify(inode, dirent))
152                         set_buffer_verified(bh);
153                 else {
154                         ext4_error_inode(inode, func, line, block,
155                                          "Directory block failed checksum");
156                         brelse(bh);
157                         return ERR_PTR(-EFSBADCRC);
158                 }
159         }
160         return bh;
161 }
162
163 #ifndef assert
164 #define assert(test) J_ASSERT(test)
165 #endif
166
167 #ifdef DX_DEBUG
168 #define dxtrace(command) command
169 #else
170 #define dxtrace(command)
171 #endif
172
173 struct fake_dirent
174 {
175         __le32 inode;
176         __le16 rec_len;
177         u8 name_len;
178         u8 file_type;
179 };
180
181 struct dx_countlimit
182 {
183         __le16 limit;
184         __le16 count;
185 };
186
187 struct dx_entry
188 {
189         __le32 hash;
190         __le32 block;
191 };
192
193 /*
194  * dx_root_info is laid out so that if it should somehow get overlaid by a
195  * dirent the two low bits of the hash version will be zero.  Therefore, the
196  * hash version mod 4 should never be 0.  Sincerely, the paranoia department.
197  */
198
199 struct dx_root
200 {
201         struct fake_dirent dot;
202         char dot_name[4];
203         struct fake_dirent dotdot;
204         char dotdot_name[4];
205         struct dx_root_info
206         {
207                 __le32 reserved_zero;
208                 u8 hash_version;
209                 u8 info_length; /* 8 */
210                 u8 indirect_levels;
211                 u8 unused_flags;
212         }
213         info;
214         struct dx_entry entries[0];
215 };
216
217 struct dx_node
218 {
219         struct fake_dirent fake;
220         struct dx_entry entries[0];
221 };
222
223
224 struct dx_frame
225 {
226         struct buffer_head *bh;
227         struct dx_entry *entries;
228         struct dx_entry *at;
229 };
230
231 struct dx_map_entry
232 {
233         u32 hash;
234         u16 offs;
235         u16 size;
236 };
237
238 /*
239  * This goes at the end of each htree block.
240  */
241 struct dx_tail {
242         u32 dt_reserved;
243         __le32 dt_checksum;     /* crc32c(uuid+inum+dirblock) */
244 };
245
246 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
247 static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
248 static inline unsigned dx_get_hash(struct dx_entry *entry);
249 static void dx_set_hash(struct dx_entry *entry, unsigned value);
250 static unsigned dx_get_count(struct dx_entry *entries);
251 static unsigned dx_get_limit(struct dx_entry *entries);
252 static void dx_set_count(struct dx_entry *entries, unsigned value);
253 static void dx_set_limit(struct dx_entry *entries, unsigned value);
254 static unsigned dx_root_limit(struct inode *dir, unsigned infosize);
255 static unsigned dx_node_limit(struct inode *dir);
256 static struct dx_frame *dx_probe(struct ext4_filename *fname,
257                                  struct inode *dir,
258                                  struct dx_hash_info *hinfo,
259                                  struct dx_frame *frame);
260 static void dx_release(struct dx_frame *frames);
261 static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de,
262                        unsigned blocksize, struct dx_hash_info *hinfo,
263                        struct dx_map_entry map[]);
264 static void dx_sort_map(struct dx_map_entry *map, unsigned count);
265 static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to,
266                 struct dx_map_entry *offsets, int count, unsigned blocksize);
267 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize);
268 static void dx_insert_block(struct dx_frame *frame,
269                                         u32 hash, ext4_lblk_t block);
270 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
271                                  struct dx_frame *frame,
272                                  struct dx_frame *frames,
273                                  __u32 *start_hash);
274 static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
275                 struct ext4_filename *fname,
276                 struct ext4_dir_entry_2 **res_dir);
277 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
278                              struct inode *dir, struct inode *inode);
279
280 /* checksumming functions */
281 void initialize_dirent_tail(struct ext4_dir_entry_tail *t,
282                             unsigned int blocksize)
283 {
284         memset(t, 0, sizeof(struct ext4_dir_entry_tail));
285         t->det_rec_len = ext4_rec_len_to_disk(
286                         sizeof(struct ext4_dir_entry_tail), blocksize);
287         t->det_reserved_ft = EXT4_FT_DIR_CSUM;
288 }
289
290 /* Walk through a dirent block to find a checksum "dirent" at the tail */
291 static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode,
292                                                    struct ext4_dir_entry *de)
293 {
294         struct ext4_dir_entry_tail *t;
295
296 #ifdef PARANOID
297         struct ext4_dir_entry *d, *top;
298
299         d = de;
300         top = (struct ext4_dir_entry *)(((void *)de) +
301                 (EXT4_BLOCK_SIZE(inode->i_sb) -
302                 sizeof(struct ext4_dir_entry_tail)));
303         while (d < top && d->rec_len)
304                 d = (struct ext4_dir_entry *)(((void *)d) +
305                     le16_to_cpu(d->rec_len));
306
307         if (d != top)
308                 return NULL;
309
310         t = (struct ext4_dir_entry_tail *)d;
311 #else
312         t = EXT4_DIRENT_TAIL(de, EXT4_BLOCK_SIZE(inode->i_sb));
313 #endif
314
315         if (t->det_reserved_zero1 ||
316             le16_to_cpu(t->det_rec_len) != sizeof(struct ext4_dir_entry_tail) ||
317             t->det_reserved_zero2 ||
318             t->det_reserved_ft != EXT4_FT_DIR_CSUM)
319                 return NULL;
320
321         return t;
322 }
323
324 static __le32 ext4_dirent_csum(struct inode *inode,
325                                struct ext4_dir_entry *dirent, int size)
326 {
327         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
328         struct ext4_inode_info *ei = EXT4_I(inode);
329         __u32 csum;
330
331         csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
332         return cpu_to_le32(csum);
333 }
334
335 #define warn_no_space_for_csum(inode)                                   \
336         __warn_no_space_for_csum((inode), __func__, __LINE__)
337
338 static void __warn_no_space_for_csum(struct inode *inode, const char *func,
339                                      unsigned int line)
340 {
341         __ext4_warning_inode(inode, func, line,
342                 "No space for directory leaf checksum. Please run e2fsck -D.");
343 }
344
345 int ext4_dirent_csum_verify(struct inode *inode, struct ext4_dir_entry *dirent)
346 {
347         struct ext4_dir_entry_tail *t;
348
349         if (!ext4_has_metadata_csum(inode->i_sb))
350                 return 1;
351
352         t = get_dirent_tail(inode, dirent);
353         if (!t) {
354                 warn_no_space_for_csum(inode);
355                 return 0;
356         }
357
358         if (t->det_checksum != ext4_dirent_csum(inode, dirent,
359                                                 (void *)t - (void *)dirent))
360                 return 0;
361
362         return 1;
363 }
364
365 static void ext4_dirent_csum_set(struct inode *inode,
366                                  struct ext4_dir_entry *dirent)
367 {
368         struct ext4_dir_entry_tail *t;
369
370         if (!ext4_has_metadata_csum(inode->i_sb))
371                 return;
372
373         t = get_dirent_tail(inode, dirent);
374         if (!t) {
375                 warn_no_space_for_csum(inode);
376                 return;
377         }
378
379         t->det_checksum = ext4_dirent_csum(inode, dirent,
380                                            (void *)t - (void *)dirent);
381 }
382
383 int ext4_handle_dirty_dirent_node(handle_t *handle,
384                                   struct inode *inode,
385                                   struct buffer_head *bh)
386 {
387         ext4_dirent_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
388         return ext4_handle_dirty_metadata(handle, inode, bh);
389 }
390
391 static struct dx_countlimit *get_dx_countlimit(struct inode *inode,
392                                                struct ext4_dir_entry *dirent,
393                                                int *offset)
394 {
395         struct ext4_dir_entry *dp;
396         struct dx_root_info *root;
397         int count_offset;
398
399         if (le16_to_cpu(dirent->rec_len) == EXT4_BLOCK_SIZE(inode->i_sb))
400                 count_offset = 8;
401         else if (le16_to_cpu(dirent->rec_len) == 12) {
402                 dp = (struct ext4_dir_entry *)(((void *)dirent) + 12);
403                 if (le16_to_cpu(dp->rec_len) !=
404                     EXT4_BLOCK_SIZE(inode->i_sb) - 12)
405                         return NULL;
406                 root = (struct dx_root_info *)(((void *)dp + 12));
407                 if (root->reserved_zero ||
408                     root->info_length != sizeof(struct dx_root_info))
409                         return NULL;
410                 count_offset = 32;
411         } else
412                 return NULL;
413
414         if (offset)
415                 *offset = count_offset;
416         return (struct dx_countlimit *)(((void *)dirent) + count_offset);
417 }
418
419 static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent,
420                            int count_offset, int count, struct dx_tail *t)
421 {
422         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
423         struct ext4_inode_info *ei = EXT4_I(inode);
424         __u32 csum;
425         int size;
426         __u32 dummy_csum = 0;
427         int offset = offsetof(struct dx_tail, dt_checksum);
428
429         size = count_offset + (count * sizeof(struct dx_entry));
430         csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
431         csum = ext4_chksum(sbi, csum, (__u8 *)t, offset);
432         csum = ext4_chksum(sbi, csum, (__u8 *)&dummy_csum, sizeof(dummy_csum));
433
434         return cpu_to_le32(csum);
435 }
436
437 static int ext4_dx_csum_verify(struct inode *inode,
438                                struct ext4_dir_entry *dirent)
439 {
440         struct dx_countlimit *c;
441         struct dx_tail *t;
442         int count_offset, limit, count;
443
444         if (!ext4_has_metadata_csum(inode->i_sb))
445                 return 1;
446
447         c = get_dx_countlimit(inode, dirent, &count_offset);
448         if (!c) {
449                 EXT4_ERROR_INODE(inode, "dir seems corrupt?  Run e2fsck -D.");
450                 return 0;
451         }
452         limit = le16_to_cpu(c->limit);
453         count = le16_to_cpu(c->count);
454         if (count_offset + (limit * sizeof(struct dx_entry)) >
455             EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
456                 warn_no_space_for_csum(inode);
457                 return 0;
458         }
459         t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
460
461         if (t->dt_checksum != ext4_dx_csum(inode, dirent, count_offset,
462                                             count, t))
463                 return 0;
464         return 1;
465 }
466
467 static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent)
468 {
469         struct dx_countlimit *c;
470         struct dx_tail *t;
471         int count_offset, limit, count;
472
473         if (!ext4_has_metadata_csum(inode->i_sb))
474                 return;
475
476         c = get_dx_countlimit(inode, dirent, &count_offset);
477         if (!c) {
478                 EXT4_ERROR_INODE(inode, "dir seems corrupt?  Run e2fsck -D.");
479                 return;
480         }
481         limit = le16_to_cpu(c->limit);
482         count = le16_to_cpu(c->count);
483         if (count_offset + (limit * sizeof(struct dx_entry)) >
484             EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
485                 warn_no_space_for_csum(inode);
486                 return;
487         }
488         t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
489
490         t->dt_checksum = ext4_dx_csum(inode, dirent, count_offset, count, t);
491 }
492
493 static inline int ext4_handle_dirty_dx_node(handle_t *handle,
494                                             struct inode *inode,
495                                             struct buffer_head *bh)
496 {
497         ext4_dx_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
498         return ext4_handle_dirty_metadata(handle, inode, bh);
499 }
500
501 /*
502  * p is at least 6 bytes before the end of page
503  */
504 static inline struct ext4_dir_entry_2 *
505 ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
506 {
507         return (struct ext4_dir_entry_2 *)((char *)p +
508                 ext4_rec_len_from_disk(p->rec_len, blocksize));
509 }
510
511 /*
512  * Future: use high four bits of block for coalesce-on-delete flags
513  * Mask them off for now.
514  */
515
516 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
517 {
518         return le32_to_cpu(entry->block) & 0x0fffffff;
519 }
520
521 static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
522 {
523         entry->block = cpu_to_le32(value);
524 }
525
526 static inline unsigned dx_get_hash(struct dx_entry *entry)
527 {
528         return le32_to_cpu(entry->hash);
529 }
530
531 static inline void dx_set_hash(struct dx_entry *entry, unsigned value)
532 {
533         entry->hash = cpu_to_le32(value);
534 }
535
536 static inline unsigned dx_get_count(struct dx_entry *entries)
537 {
538         return le16_to_cpu(((struct dx_countlimit *) entries)->count);
539 }
540
541 static inline unsigned dx_get_limit(struct dx_entry *entries)
542 {
543         return le16_to_cpu(((struct dx_countlimit *) entries)->limit);
544 }
545
546 static inline void dx_set_count(struct dx_entry *entries, unsigned value)
547 {
548         ((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
549 }
550
551 static inline void dx_set_limit(struct dx_entry *entries, unsigned value)
552 {
553         ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
554 }
555
556 static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
557 {
558         unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
559                 EXT4_DIR_REC_LEN(2) - infosize;
560
561         if (ext4_has_metadata_csum(dir->i_sb))
562                 entry_space -= sizeof(struct dx_tail);
563         return entry_space / sizeof(struct dx_entry);
564 }
565
566 static inline unsigned dx_node_limit(struct inode *dir)
567 {
568         unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);
569
570         if (ext4_has_metadata_csum(dir->i_sb))
571                 entry_space -= sizeof(struct dx_tail);
572         return entry_space / sizeof(struct dx_entry);
573 }
574
575 /*
576  * Debug
577  */
578 #ifdef DX_DEBUG
579 static void dx_show_index(char * label, struct dx_entry *entries)
580 {
581         int i, n = dx_get_count (entries);
582         printk(KERN_DEBUG "%s index", label);
583         for (i = 0; i < n; i++) {
584                 printk(KERN_CONT " %x->%lu",
585                        i ? dx_get_hash(entries + i) : 0,
586                        (unsigned long)dx_get_block(entries + i));
587         }
588         printk(KERN_CONT "\n");
589 }
590
591 struct stats
592 {
593         unsigned names;
594         unsigned space;
595         unsigned bcount;
596 };
597
598 static struct stats dx_show_leaf(struct inode *dir,
599                                 struct dx_hash_info *hinfo,
600                                 struct ext4_dir_entry_2 *de,
601                                 int size, int show_names)
602 {
603         unsigned names = 0, space = 0;
604         char *base = (char *) de;
605         struct dx_hash_info h = *hinfo;
606
607         printk("names: ");
608         while ((char *) de < base + size)
609         {
610                 if (de->inode)
611                 {
612                         if (show_names)
613                         {
614 #ifdef CONFIG_EXT4_FS_ENCRYPTION
615                                 int len;
616                                 char *name;
617                                 struct fscrypt_str fname_crypto_str =
618                                         FSTR_INIT(NULL, 0);
619                                 int res = 0;
620
621                                 name  = de->name;
622                                 len = de->name_len;
623                                 if (ext4_encrypted_inode(dir))
624                                         res = fscrypt_get_encryption_info(dir);
625                                 if (res) {
626                                         printk(KERN_WARNING "Error setting up"
627                                                " fname crypto: %d\n", res);
628                                 }
629                                 if (!fscrypt_has_encryption_key(dir)) {
630                                         /* Directory is not encrypted */
631                                         ext4fs_dirhash(de->name,
632                                                 de->name_len, &h);
633                                         printk("%*.s:(U)%x.%u ", len,
634                                                name, h.hash,
635                                                (unsigned) ((char *) de
636                                                            - base));
637                                 } else {
638                                         struct fscrypt_str de_name =
639                                                 FSTR_INIT(name, len);
640
641                                         /* Directory is encrypted */
642                                         res = fscrypt_fname_alloc_buffer(
643                                                 dir, len,
644                                                 &fname_crypto_str);
645                                         if (res)
646                                                 printk(KERN_WARNING "Error "
647                                                         "allocating crypto "
648                                                         "buffer--skipping "
649                                                         "crypto\n");
650                                         res = fscrypt_fname_disk_to_usr(dir,
651                                                 0, 0, &de_name,
652                                                 &fname_crypto_str);
653                                         if (res) {
654                                                 printk(KERN_WARNING "Error "
655                                                         "converting filename "
656                                                         "from disk to usr"
657                                                         "\n");
658                                                 name = "??";
659                                                 len = 2;
660                                         } else {
661                                                 name = fname_crypto_str.name;
662                                                 len = fname_crypto_str.len;
663                                         }
664                                         ext4fs_dirhash(de->name, de->name_len,
665                                                        &h);
666                                         printk("%*.s:(E)%x.%u ", len, name,
667                                                h.hash, (unsigned) ((char *) de
668                                                                    - base));
669                                         fscrypt_fname_free_buffer(
670                                                         &fname_crypto_str);
671                                 }
672 #else
673                                 int len = de->name_len;
674                                 char *name = de->name;
675                                 ext4fs_dirhash(de->name, de->name_len, &h);
676                                 printk("%*.s:%x.%u ", len, name, h.hash,
677                                        (unsigned) ((char *) de - base));
678 #endif
679                         }
680                         space += EXT4_DIR_REC_LEN(de->name_len);
681                         names++;
682                 }
683                 de = ext4_next_entry(de, size);
684         }
685         printk(KERN_CONT "(%i)\n", names);
686         return (struct stats) { names, space, 1 };
687 }
688
689 struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
690                              struct dx_entry *entries, int levels)
691 {
692         unsigned blocksize = dir->i_sb->s_blocksize;
693         unsigned count = dx_get_count(entries), names = 0, space = 0, i;
694         unsigned bcount = 0;
695         struct buffer_head *bh;
696         printk("%i indexed blocks...\n", count);
697         for (i = 0; i < count; i++, entries++)
698         {
699                 ext4_lblk_t block = dx_get_block(entries);
700                 ext4_lblk_t hash  = i ? dx_get_hash(entries): 0;
701                 u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
702                 struct stats stats;
703                 printk("%s%3u:%03u hash %8x/%8x ",levels?"":"   ", i, block, hash, range);
704                 bh = ext4_bread(NULL,dir, block, 0);
705                 if (!bh || IS_ERR(bh))
706                         continue;
707                 stats = levels?
708                    dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
709                    dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *)
710                         bh->b_data, blocksize, 0);
711                 names += stats.names;
712                 space += stats.space;
713                 bcount += stats.bcount;
714                 brelse(bh);
715         }
716         if (bcount)
717                 printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n",
718                        levels ? "" : "   ", names, space/bcount,
719                        (space/bcount)*100/blocksize);
720         return (struct stats) { names, space, bcount};
721 }
722 #endif /* DX_DEBUG */
723
724 /*
725  * Probe for a directory leaf block to search.
726  *
727  * dx_probe can return ERR_BAD_DX_DIR, which means there was a format
728  * error in the directory index, and the caller should fall back to
729  * searching the directory normally.  The callers of dx_probe **MUST**
730  * check for this error code, and make sure it never gets reflected
731  * back to userspace.
732  */
733 static struct dx_frame *
734 dx_probe(struct ext4_filename *fname, struct inode *dir,
735          struct dx_hash_info *hinfo, struct dx_frame *frame_in)
736 {
737         unsigned count, indirect;
738         struct dx_entry *at, *entries, *p, *q, *m;
739         struct dx_root *root;
740         struct dx_frame *frame = frame_in;
741         struct dx_frame *ret_err = ERR_PTR(ERR_BAD_DX_DIR);
742         u32 hash;
743
744         memset(frame_in, 0, EXT4_HTREE_LEVEL * sizeof(frame_in[0]));
745         frame->bh = ext4_read_dirblock(dir, 0, INDEX);
746         if (IS_ERR(frame->bh))
747                 return (struct dx_frame *) frame->bh;
748
749         root = (struct dx_root *) frame->bh->b_data;
750         if (root->info.hash_version != DX_HASH_TEA &&
751             root->info.hash_version != DX_HASH_HALF_MD4 &&
752             root->info.hash_version != DX_HASH_LEGACY) {
753                 ext4_warning_inode(dir, "Unrecognised inode hash code %u",
754                                    root->info.hash_version);
755                 goto fail;
756         }
757         if (fname)
758                 hinfo = &fname->hinfo;
759         hinfo->hash_version = root->info.hash_version;
760         if (hinfo->hash_version <= DX_HASH_TEA)
761                 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
762         hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
763         if (fname && fname_name(fname))
764                 ext4fs_dirhash(fname_name(fname), fname_len(fname), hinfo);
765         hash = hinfo->hash;
766
767         if (root->info.unused_flags & 1) {
768                 ext4_warning_inode(dir, "Unimplemented hash flags: %#06x",
769                                    root->info.unused_flags);
770                 goto fail;
771         }
772
773         indirect = root->info.indirect_levels;
774         if (indirect >= ext4_dir_htree_level(dir->i_sb)) {
775                 ext4_warning(dir->i_sb,
776                              "Directory (ino: %lu) htree depth %#06x exceed"
777                              "supported value", dir->i_ino,
778                              ext4_dir_htree_level(dir->i_sb));
779                 if (ext4_dir_htree_level(dir->i_sb) < EXT4_HTREE_LEVEL) {
780                         ext4_warning(dir->i_sb, "Enable large directory "
781                                                 "feature to access it");
782                 }
783                 goto fail;
784         }
785
786         entries = (struct dx_entry *)(((char *)&root->info) +
787                                       root->info.info_length);
788
789         if (dx_get_limit(entries) != dx_root_limit(dir,
790                                                    root->info.info_length)) {
791                 ext4_warning_inode(dir, "dx entry: limit %u != root limit %u",
792                                    dx_get_limit(entries),
793                                    dx_root_limit(dir, root->info.info_length));
794                 goto fail;
795         }
796
797         dxtrace(printk("Look up %x", hash));
798         while (1) {
799                 count = dx_get_count(entries);
800                 if (!count || count > dx_get_limit(entries)) {
801                         ext4_warning_inode(dir,
802                                            "dx entry: count %u beyond limit %u",
803                                            count, dx_get_limit(entries));
804                         goto fail;
805                 }
806
807                 p = entries + 1;
808                 q = entries + count - 1;
809                 while (p <= q) {
810                         m = p + (q - p) / 2;
811                         dxtrace(printk(KERN_CONT "."));
812                         if (dx_get_hash(m) > hash)
813                                 q = m - 1;
814                         else
815                                 p = m + 1;
816                 }
817
818                 if (0) { // linear search cross check
819                         unsigned n = count - 1;
820                         at = entries;
821                         while (n--)
822                         {
823                                 dxtrace(printk(KERN_CONT ","));
824                                 if (dx_get_hash(++at) > hash)
825                                 {
826                                         at--;
827                                         break;
828                                 }
829                         }
830                         assert (at == p - 1);
831                 }
832
833                 at = p - 1;
834                 dxtrace(printk(KERN_CONT " %x->%u\n",
835                                at == entries ? 0 : dx_get_hash(at),
836                                dx_get_block(at)));
837                 frame->entries = entries;
838                 frame->at = at;
839                 if (!indirect--)
840                         return frame;
841                 frame++;
842                 frame->bh = ext4_read_dirblock(dir, dx_get_block(at), INDEX);
843                 if (IS_ERR(frame->bh)) {
844                         ret_err = (struct dx_frame *) frame->bh;
845                         frame->bh = NULL;
846                         goto fail;
847                 }
848                 entries = ((struct dx_node *) frame->bh->b_data)->entries;
849
850                 if (dx_get_limit(entries) != dx_node_limit(dir)) {
851                         ext4_warning_inode(dir,
852                                 "dx entry: limit %u != node limit %u",
853                                 dx_get_limit(entries), dx_node_limit(dir));
854                         goto fail;
855                 }
856         }
857 fail:
858         while (frame >= frame_in) {
859                 brelse(frame->bh);
860                 frame--;
861         }
862
863         if (ret_err == ERR_PTR(ERR_BAD_DX_DIR))
864                 ext4_warning_inode(dir,
865                         "Corrupt directory, running e2fsck is recommended");
866         return ret_err;
867 }
868
869 static void dx_release(struct dx_frame *frames)
870 {
871         struct dx_root_info *info;
872         int i;
873
874         if (frames[0].bh == NULL)
875                 return;
876
877         info = &((struct dx_root *)frames[0].bh->b_data)->info;
878         for (i = 0; i <= info->indirect_levels; i++) {
879                 if (frames[i].bh == NULL)
880                         break;
881                 brelse(frames[i].bh);
882                 frames[i].bh = NULL;
883         }
884 }
885
886 /*
887  * This function increments the frame pointer to search the next leaf
888  * block, and reads in the necessary intervening nodes if the search
889  * should be necessary.  Whether or not the search is necessary is
890  * controlled by the hash parameter.  If the hash value is even, then
891  * the search is only continued if the next block starts with that
892  * hash value.  This is used if we are searching for a specific file.
893  *
894  * If the hash value is HASH_NB_ALWAYS, then always go to the next block.
895  *
896  * This function returns 1 if the caller should continue to search,
897  * or 0 if it should not.  If there is an error reading one of the
898  * index blocks, it will a negative error code.
899  *
900  * If start_hash is non-null, it will be filled in with the starting
901  * hash of the next page.
902  */
903 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
904                                  struct dx_frame *frame,
905                                  struct dx_frame *frames,
906                                  __u32 *start_hash)
907 {
908         struct dx_frame *p;
909         struct buffer_head *bh;
910         int num_frames = 0;
911         __u32 bhash;
912
913         p = frame;
914         /*
915          * Find the next leaf page by incrementing the frame pointer.
916          * If we run out of entries in the interior node, loop around and
917          * increment pointer in the parent node.  When we break out of
918          * this loop, num_frames indicates the number of interior
919          * nodes need to be read.
920          */
921         while (1) {
922                 if (++(p->at) < p->entries + dx_get_count(p->entries))
923                         break;
924                 if (p == frames)
925                         return 0;
926                 num_frames++;
927                 p--;
928         }
929
930         /*
931          * If the hash is 1, then continue only if the next page has a
932          * continuation hash of any value.  This is used for readdir
933          * handling.  Otherwise, check to see if the hash matches the
934          * desired contiuation hash.  If it doesn't, return since
935          * there's no point to read in the successive index pages.
936          */
937         bhash = dx_get_hash(p->at);
938         if (start_hash)
939                 *start_hash = bhash;
940         if ((hash & 1) == 0) {
941                 if ((bhash & ~1) != hash)
942                         return 0;
943         }
944         /*
945          * If the hash is HASH_NB_ALWAYS, we always go to the next
946          * block so no check is necessary
947          */
948         while (num_frames--) {
949                 bh = ext4_read_dirblock(dir, dx_get_block(p->at), INDEX);
950                 if (IS_ERR(bh))
951                         return PTR_ERR(bh);
952                 p++;
953                 brelse(p->bh);
954                 p->bh = bh;
955                 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
956         }
957         return 1;
958 }
959
960
961 /*
962  * This function fills a red-black tree with information from a
963  * directory block.  It returns the number directory entries loaded
964  * into the tree.  If there is an error it is returned in err.
965  */
966 static int htree_dirblock_to_tree(struct file *dir_file,
967                                   struct inode *dir, ext4_lblk_t block,
968                                   struct dx_hash_info *hinfo,
969                                   __u32 start_hash, __u32 start_minor_hash)
970 {
971         struct buffer_head *bh;
972         struct ext4_dir_entry_2 *de, *top;
973         int err = 0, count = 0;
974         struct fscrypt_str fname_crypto_str = FSTR_INIT(NULL, 0), tmp_str;
975
976         dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
977                                                         (unsigned long)block));
978         bh = ext4_read_dirblock(dir, block, DIRENT);
979         if (IS_ERR(bh))
980                 return PTR_ERR(bh);
981
982         de = (struct ext4_dir_entry_2 *) bh->b_data;
983         top = (struct ext4_dir_entry_2 *) ((char *) de +
984                                            dir->i_sb->s_blocksize -
985                                            EXT4_DIR_REC_LEN(0));
986 #ifdef CONFIG_EXT4_FS_ENCRYPTION
987         /* Check if the directory is encrypted */
988         if (ext4_encrypted_inode(dir)) {
989                 err = fscrypt_get_encryption_info(dir);
990                 if (err < 0) {
991                         brelse(bh);
992                         return err;
993                 }
994                 err = fscrypt_fname_alloc_buffer(dir, EXT4_NAME_LEN,
995                                                      &fname_crypto_str);
996                 if (err < 0) {
997                         brelse(bh);
998                         return err;
999                 }
1000         }
1001 #endif
1002         for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) {
1003                 if (ext4_check_dir_entry(dir, NULL, de, bh,
1004                                 bh->b_data, bh->b_size,
1005                                 (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
1006                                          + ((char *)de - bh->b_data))) {
1007                         /* silently ignore the rest of the block */
1008                         break;
1009                 }
1010                 ext4fs_dirhash(de->name, de->name_len, hinfo);
1011                 if ((hinfo->hash < start_hash) ||
1012                     ((hinfo->hash == start_hash) &&
1013                      (hinfo->minor_hash < start_minor_hash)))
1014                         continue;
1015                 if (de->inode == 0)
1016                         continue;
1017                 if (!ext4_encrypted_inode(dir)) {
1018                         tmp_str.name = de->name;
1019                         tmp_str.len = de->name_len;
1020                         err = ext4_htree_store_dirent(dir_file,
1021                                    hinfo->hash, hinfo->minor_hash, de,
1022                                    &tmp_str);
1023                 } else {
1024                         int save_len = fname_crypto_str.len;
1025                         struct fscrypt_str de_name = FSTR_INIT(de->name,
1026                                                                 de->name_len);
1027
1028                         /* Directory is encrypted */
1029                         err = fscrypt_fname_disk_to_usr(dir, hinfo->hash,
1030                                         hinfo->minor_hash, &de_name,
1031                                         &fname_crypto_str);
1032                         if (err) {
1033                                 count = err;
1034                                 goto errout;
1035                         }
1036                         err = ext4_htree_store_dirent(dir_file,
1037                                    hinfo->hash, hinfo->minor_hash, de,
1038                                         &fname_crypto_str);
1039                         fname_crypto_str.len = save_len;
1040                 }
1041                 if (err != 0) {
1042                         count = err;
1043                         goto errout;
1044                 }
1045                 count++;
1046         }
1047 errout:
1048         brelse(bh);
1049 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1050         fscrypt_fname_free_buffer(&fname_crypto_str);
1051 #endif
1052         return count;
1053 }
1054
1055
1056 /*
1057  * This function fills a red-black tree with information from a
1058  * directory.  We start scanning the directory in hash order, starting
1059  * at start_hash and start_minor_hash.
1060  *
1061  * This function returns the number of entries inserted into the tree,
1062  * or a negative error code.
1063  */
1064 int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
1065                          __u32 start_minor_hash, __u32 *next_hash)
1066 {
1067         struct dx_hash_info hinfo;
1068         struct ext4_dir_entry_2 *de;
1069         struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
1070         struct inode *dir;
1071         ext4_lblk_t block;
1072         int count = 0;
1073         int ret, err;
1074         __u32 hashval;
1075         struct fscrypt_str tmp_str;
1076
1077         dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
1078                        start_hash, start_minor_hash));
1079         dir = file_inode(dir_file);
1080         if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) {
1081                 hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
1082                 if (hinfo.hash_version <= DX_HASH_TEA)
1083                         hinfo.hash_version +=
1084                                 EXT4_SB(dir->i_sb)->s_hash_unsigned;
1085                 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
1086                 if (ext4_has_inline_data(dir)) {
1087                         int has_inline_data = 1;
1088                         count = htree_inlinedir_to_tree(dir_file, dir, 0,
1089                                                         &hinfo, start_hash,
1090                                                         start_minor_hash,
1091                                                         &has_inline_data);
1092                         if (has_inline_data) {
1093                                 *next_hash = ~0;
1094                                 return count;
1095                         }
1096                 }
1097                 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
1098                                                start_hash, start_minor_hash);
1099                 *next_hash = ~0;
1100                 return count;
1101         }
1102         hinfo.hash = start_hash;
1103         hinfo.minor_hash = 0;
1104         frame = dx_probe(NULL, dir, &hinfo, frames);
1105         if (IS_ERR(frame))
1106                 return PTR_ERR(frame);
1107
1108         /* Add '.' and '..' from the htree header */
1109         if (!start_hash && !start_minor_hash) {
1110                 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
1111                 tmp_str.name = de->name;
1112                 tmp_str.len = de->name_len;
1113                 err = ext4_htree_store_dirent(dir_file, 0, 0,
1114                                               de, &tmp_str);
1115                 if (err != 0)
1116                         goto errout;
1117                 count++;
1118         }
1119         if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
1120                 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
1121                 de = ext4_next_entry(de, dir->i_sb->s_blocksize);
1122                 tmp_str.name = de->name;
1123                 tmp_str.len = de->name_len;
1124                 err = ext4_htree_store_dirent(dir_file, 2, 0,
1125                                               de, &tmp_str);
1126                 if (err != 0)
1127                         goto errout;
1128                 count++;
1129         }
1130
1131         while (1) {
1132                 if (fatal_signal_pending(current)) {
1133                         err = -ERESTARTSYS;
1134                         goto errout;
1135                 }
1136                 cond_resched();
1137                 block = dx_get_block(frame->at);
1138                 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
1139                                              start_hash, start_minor_hash);
1140                 if (ret < 0) {
1141                         err = ret;
1142                         goto errout;
1143                 }
1144                 count += ret;
1145                 hashval = ~0;
1146                 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
1147                                             frame, frames, &hashval);
1148                 *next_hash = hashval;
1149                 if (ret < 0) {
1150                         err = ret;
1151                         goto errout;
1152                 }
1153                 /*
1154                  * Stop if:  (a) there are no more entries, or
1155                  * (b) we have inserted at least one entry and the
1156                  * next hash value is not a continuation
1157                  */
1158                 if ((ret == 0) ||
1159                     (count && ((hashval & 1) == 0)))
1160                         break;
1161         }
1162         dx_release(frames);
1163         dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, "
1164                        "next hash: %x\n", count, *next_hash));
1165         return count;
1166 errout:
1167         dx_release(frames);
1168         return (err);
1169 }
1170
1171 static inline int search_dirblock(struct buffer_head *bh,
1172                                   struct inode *dir,
1173                                   struct ext4_filename *fname,
1174                                   unsigned int offset,
1175                                   struct ext4_dir_entry_2 **res_dir)
1176 {
1177         return ext4_search_dir(bh, bh->b_data, dir->i_sb->s_blocksize, dir,
1178                                fname, offset, res_dir);
1179 }
1180
1181 /*
1182  * Directory block splitting, compacting
1183  */
1184
1185 /*
1186  * Create map of hash values, offsets, and sizes, stored at end of block.
1187  * Returns number of entries mapped.
1188  */
1189 static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de,
1190                        unsigned blocksize, struct dx_hash_info *hinfo,
1191                        struct dx_map_entry *map_tail)
1192 {
1193         int count = 0;
1194         char *base = (char *) de;
1195         struct dx_hash_info h = *hinfo;
1196
1197         while ((char *) de < base + blocksize) {
1198                 if (de->name_len && de->inode) {
1199                         ext4fs_dirhash(de->name, de->name_len, &h);
1200                         map_tail--;
1201                         map_tail->hash = h.hash;
1202                         map_tail->offs = ((char *) de - base)>>2;
1203                         map_tail->size = le16_to_cpu(de->rec_len);
1204                         count++;
1205                         cond_resched();
1206                 }
1207                 /* XXX: do we need to check rec_len == 0 case? -Chris */
1208                 de = ext4_next_entry(de, blocksize);
1209         }
1210         return count;
1211 }
1212
1213 /* Sort map by hash value */
1214 static void dx_sort_map (struct dx_map_entry *map, unsigned count)
1215 {
1216         struct dx_map_entry *p, *q, *top = map + count - 1;
1217         int more;
1218         /* Combsort until bubble sort doesn't suck */
1219         while (count > 2) {
1220                 count = count*10/13;
1221                 if (count - 9 < 2) /* 9, 10 -> 11 */
1222                         count = 11;
1223                 for (p = top, q = p - count; q >= map; p--, q--)
1224                         if (p->hash < q->hash)
1225                                 swap(*p, *q);
1226         }
1227         /* Garden variety bubble sort */
1228         do {
1229                 more = 0;
1230                 q = top;
1231                 while (q-- > map) {
1232                         if (q[1].hash >= q[0].hash)
1233                                 continue;
1234                         swap(*(q+1), *q);
1235                         more = 1;
1236                 }
1237         } while(more);
1238 }
1239
1240 static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
1241 {
1242         struct dx_entry *entries = frame->entries;
1243         struct dx_entry *old = frame->at, *new = old + 1;
1244         int count = dx_get_count(entries);
1245
1246         assert(count < dx_get_limit(entries));
1247         assert(old < entries + count);
1248         memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
1249         dx_set_hash(new, hash);
1250         dx_set_block(new, block);
1251         dx_set_count(entries, count + 1);
1252 }
1253
1254 /*
1255  * Test whether a directory entry matches the filename being searched for.
1256  *
1257  * Return: %true if the directory entry matches, otherwise %false.
1258  */
1259 static inline bool ext4_match(const struct ext4_filename *fname,
1260                               const struct ext4_dir_entry_2 *de)
1261 {
1262         struct fscrypt_name f;
1263
1264         if (!de->inode)
1265                 return false;
1266
1267         f.usr_fname = fname->usr_fname;
1268         f.disk_name = fname->disk_name;
1269 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1270         f.crypto_buf = fname->crypto_buf;
1271 #endif
1272         return fscrypt_match_name(&f, de->name, de->name_len);
1273 }
1274
1275 /*
1276  * Returns 0 if not found, -1 on failure, and 1 on success
1277  */
1278 int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size,
1279                     struct inode *dir, struct ext4_filename *fname,
1280                     unsigned int offset, struct ext4_dir_entry_2 **res_dir)
1281 {
1282         struct ext4_dir_entry_2 * de;
1283         char * dlimit;
1284         int de_len;
1285
1286         de = (struct ext4_dir_entry_2 *)search_buf;
1287         dlimit = search_buf + buf_size;
1288         while ((char *) de < dlimit) {
1289                 /* this code is executed quadratically often */
1290                 /* do minimal checking `by hand' */
1291                 if ((char *) de + de->name_len <= dlimit &&
1292                     ext4_match(fname, de)) {
1293                         /* found a match - just to be sure, do
1294                          * a full check */
1295                         if (ext4_check_dir_entry(dir, NULL, de, bh, bh->b_data,
1296                                                  bh->b_size, offset))
1297                                 return -1;
1298                         *res_dir = de;
1299                         return 1;
1300                 }
1301                 /* prevent looping on a bad block */
1302                 de_len = ext4_rec_len_from_disk(de->rec_len,
1303                                                 dir->i_sb->s_blocksize);
1304                 if (de_len <= 0)
1305                         return -1;
1306                 offset += de_len;
1307                 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
1308         }
1309         return 0;
1310 }
1311
1312 static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block,
1313                                struct ext4_dir_entry *de)
1314 {
1315         struct super_block *sb = dir->i_sb;
1316
1317         if (!is_dx(dir))
1318                 return 0;
1319         if (block == 0)
1320                 return 1;
1321         if (de->inode == 0 &&
1322             ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) ==
1323                         sb->s_blocksize)
1324                 return 1;
1325         return 0;
1326 }
1327
1328 /*
1329  *      ext4_find_entry()
1330  *
1331  * finds an entry in the specified directory with the wanted name. It
1332  * returns the cache buffer in which the entry was found, and the entry
1333  * itself (as a parameter - res_dir). It does NOT read the inode of the
1334  * entry - you'll have to do that yourself if you want to.
1335  *
1336  * The returned buffer_head has ->b_count elevated.  The caller is expected
1337  * to brelse() it when appropriate.
1338  */
1339 static struct buffer_head * ext4_find_entry (struct inode *dir,
1340                                         const struct qstr *d_name,
1341                                         struct ext4_dir_entry_2 **res_dir,
1342                                         int *inlined)
1343 {
1344         struct super_block *sb;
1345         struct buffer_head *bh_use[NAMEI_RA_SIZE];
1346         struct buffer_head *bh, *ret = NULL;
1347         ext4_lblk_t start, block;
1348         const u8 *name = d_name->name;
1349         size_t ra_max = 0;      /* Number of bh's in the readahead
1350                                    buffer, bh_use[] */
1351         size_t ra_ptr = 0;      /* Current index into readahead
1352                                    buffer */
1353         ext4_lblk_t  nblocks;
1354         int i, namelen, retval;
1355         struct ext4_filename fname;
1356
1357         *res_dir = NULL;
1358         sb = dir->i_sb;
1359         namelen = d_name->len;
1360         if (namelen > EXT4_NAME_LEN)
1361                 return NULL;
1362
1363         retval = ext4_fname_setup_filename(dir, d_name, 1, &fname);
1364         if (retval == -ENOENT)
1365                 return NULL;
1366         if (retval)
1367                 return ERR_PTR(retval);
1368
1369         if (ext4_has_inline_data(dir)) {
1370                 int has_inline_data = 1;
1371                 ret = ext4_find_inline_entry(dir, &fname, res_dir,
1372                                              &has_inline_data);
1373                 if (has_inline_data) {
1374                         if (inlined)
1375                                 *inlined = 1;
1376                         goto cleanup_and_exit;
1377                 }
1378         }
1379
1380         if ((namelen <= 2) && (name[0] == '.') &&
1381             (name[1] == '.' || name[1] == '\0')) {
1382                 /*
1383                  * "." or ".." will only be in the first block
1384                  * NFS may look up ".."; "." should be handled by the VFS
1385                  */
1386                 block = start = 0;
1387                 nblocks = 1;
1388                 goto restart;
1389         }
1390         if (is_dx(dir)) {
1391                 ret = ext4_dx_find_entry(dir, &fname, res_dir);
1392                 /*
1393                  * On success, or if the error was file not found,
1394                  * return.  Otherwise, fall back to doing a search the
1395                  * old fashioned way.
1396                  */
1397                 if (!IS_ERR(ret) || PTR_ERR(ret) != ERR_BAD_DX_DIR)
1398                         goto cleanup_and_exit;
1399                 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
1400                                "falling back\n"));
1401                 ret = NULL;
1402         }
1403         nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1404         if (!nblocks) {
1405                 ret = NULL;
1406                 goto cleanup_and_exit;
1407         }
1408         start = EXT4_I(dir)->i_dir_start_lookup;
1409         if (start >= nblocks)
1410                 start = 0;
1411         block = start;
1412 restart:
1413         do {
1414                 /*
1415                  * We deal with the read-ahead logic here.
1416                  */
1417                 if (ra_ptr >= ra_max) {
1418                         /* Refill the readahead buffer */
1419                         ra_ptr = 0;
1420                         if (block < start)
1421                                 ra_max = start - block;
1422                         else
1423                                 ra_max = nblocks - block;
1424                         ra_max = min(ra_max, ARRAY_SIZE(bh_use));
1425                         retval = ext4_bread_batch(dir, block, ra_max,
1426                                                   false /* wait */, bh_use);
1427                         if (retval) {
1428                                 ret = ERR_PTR(retval);
1429                                 ra_max = 0;
1430                                 goto cleanup_and_exit;
1431                         }
1432                 }
1433                 if ((bh = bh_use[ra_ptr++]) == NULL)
1434                         goto next;
1435                 wait_on_buffer(bh);
1436                 if (!buffer_uptodate(bh)) {
1437                         EXT4_ERROR_INODE(dir, "reading directory lblock %lu",
1438                                          (unsigned long) block);
1439                         brelse(bh);
1440                         ret = ERR_PTR(-EIO);
1441                         goto cleanup_and_exit;
1442                 }
1443                 if (!buffer_verified(bh) &&
1444                     !is_dx_internal_node(dir, block,
1445                                          (struct ext4_dir_entry *)bh->b_data) &&
1446                     !ext4_dirent_csum_verify(dir,
1447                                 (struct ext4_dir_entry *)bh->b_data)) {
1448                         EXT4_ERROR_INODE(dir, "checksumming directory "
1449                                          "block %lu", (unsigned long)block);
1450                         brelse(bh);
1451                         ret = ERR_PTR(-EFSBADCRC);
1452                         goto cleanup_and_exit;
1453                 }
1454                 set_buffer_verified(bh);
1455                 i = search_dirblock(bh, dir, &fname,
1456                             block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
1457                 if (i == 1) {
1458                         EXT4_I(dir)->i_dir_start_lookup = block;
1459                         ret = bh;
1460                         goto cleanup_and_exit;
1461                 } else {
1462                         brelse(bh);
1463                         if (i < 0)
1464                                 goto cleanup_and_exit;
1465                 }
1466         next:
1467                 if (++block >= nblocks)
1468                         block = 0;
1469         } while (block != start);
1470
1471         /*
1472          * If the directory has grown while we were searching, then
1473          * search the last part of the directory before giving up.
1474          */
1475         block = nblocks;
1476         nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1477         if (block < nblocks) {
1478                 start = 0;
1479                 goto restart;
1480         }
1481
1482 cleanup_and_exit:
1483         /* Clean up the read-ahead blocks */
1484         for (; ra_ptr < ra_max; ra_ptr++)
1485                 brelse(bh_use[ra_ptr]);
1486         ext4_fname_free_filename(&fname);
1487         return ret;
1488 }
1489
1490 static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
1491                         struct ext4_filename *fname,
1492                         struct ext4_dir_entry_2 **res_dir)
1493 {
1494         struct super_block * sb = dir->i_sb;
1495         struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
1496         struct buffer_head *bh;
1497         ext4_lblk_t block;
1498         int retval;
1499
1500 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1501         *res_dir = NULL;
1502 #endif
1503         frame = dx_probe(fname, dir, NULL, frames);
1504         if (IS_ERR(frame))
1505                 return (struct buffer_head *) frame;
1506         do {
1507                 block = dx_get_block(frame->at);
1508                 bh = ext4_read_dirblock(dir, block, DIRENT);
1509                 if (IS_ERR(bh))
1510                         goto errout;
1511
1512                 retval = search_dirblock(bh, dir, fname,
1513                                          block << EXT4_BLOCK_SIZE_BITS(sb),
1514                                          res_dir);
1515                 if (retval == 1)
1516                         goto success;
1517                 brelse(bh);
1518                 if (retval == -1) {
1519                         bh = ERR_PTR(ERR_BAD_DX_DIR);
1520                         goto errout;
1521                 }
1522
1523                 /* Check to see if we should continue to search */
1524                 retval = ext4_htree_next_block(dir, fname->hinfo.hash, frame,
1525                                                frames, NULL);
1526                 if (retval < 0) {
1527                         ext4_warning_inode(dir,
1528                                 "error %d reading directory index block",
1529                                 retval);
1530                         bh = ERR_PTR(retval);
1531                         goto errout;
1532                 }
1533         } while (retval == 1);
1534
1535         bh = NULL;
1536 errout:
1537         dxtrace(printk(KERN_DEBUG "%s not found\n", fname->usr_fname->name));
1538 success:
1539         dx_release(frames);
1540         return bh;
1541 }
1542
1543 static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
1544 {
1545         struct inode *inode;
1546         struct ext4_dir_entry_2 *de;
1547         struct buffer_head *bh;
1548         int err;
1549
1550         err = fscrypt_prepare_lookup(dir, dentry, flags);
1551         if (err)
1552                 return ERR_PTR(err);
1553
1554         if (dentry->d_name.len > EXT4_NAME_LEN)
1555                 return ERR_PTR(-ENAMETOOLONG);
1556
1557         bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
1558         if (IS_ERR(bh))
1559                 return ERR_CAST(bh);
1560         inode = NULL;
1561         if (bh) {
1562                 __u32 ino = le32_to_cpu(de->inode);
1563                 brelse(bh);
1564                 if (!ext4_valid_inum(dir->i_sb, ino)) {
1565                         EXT4_ERROR_INODE(dir, "bad inode number: %u", ino);
1566                         return ERR_PTR(-EFSCORRUPTED);
1567                 }
1568                 if (unlikely(ino == dir->i_ino)) {
1569                         EXT4_ERROR_INODE(dir, "'%pd' linked to parent dir",
1570                                          dentry);
1571                         return ERR_PTR(-EFSCORRUPTED);
1572                 }
1573                 inode = ext4_iget_normal(dir->i_sb, ino);
1574                 if (inode == ERR_PTR(-ESTALE)) {
1575                         EXT4_ERROR_INODE(dir,
1576                                          "deleted inode referenced: %u",
1577                                          ino);
1578                         return ERR_PTR(-EFSCORRUPTED);
1579                 }
1580                 if (!IS_ERR(inode) && ext4_encrypted_inode(dir) &&
1581                     (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) &&
1582                     !fscrypt_has_permitted_context(dir, inode)) {
1583                         ext4_warning(inode->i_sb,
1584                                      "Inconsistent encryption contexts: %lu/%lu",
1585                                      dir->i_ino, inode->i_ino);
1586                         iput(inode);
1587                         return ERR_PTR(-EPERM);
1588                 }
1589         }
1590         return d_splice_alias(inode, dentry);
1591 }
1592
1593
1594 struct dentry *ext4_get_parent(struct dentry *child)
1595 {
1596         __u32 ino;
1597         static const struct qstr dotdot = QSTR_INIT("..", 2);
1598         struct ext4_dir_entry_2 * de;
1599         struct buffer_head *bh;
1600
1601         bh = ext4_find_entry(d_inode(child), &dotdot, &de, NULL);
1602         if (IS_ERR(bh))
1603                 return ERR_CAST(bh);
1604         if (!bh)
1605                 return ERR_PTR(-ENOENT);
1606         ino = le32_to_cpu(de->inode);
1607         brelse(bh);
1608
1609         if (!ext4_valid_inum(child->d_sb, ino)) {
1610                 EXT4_ERROR_INODE(d_inode(child),
1611                                  "bad parent inode number: %u", ino);
1612                 return ERR_PTR(-EFSCORRUPTED);
1613         }
1614
1615         return d_obtain_alias(ext4_iget_normal(child->d_sb, ino));
1616 }
1617
1618 /*
1619  * Move count entries from end of map between two memory locations.
1620  * Returns pointer to last entry moved.
1621  */
1622 static struct ext4_dir_entry_2 *
1623 dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count,
1624                 unsigned blocksize)
1625 {
1626         unsigned rec_len = 0;
1627
1628         while (count--) {
1629                 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
1630                                                 (from + (map->offs<<2));
1631                 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1632                 memcpy (to, de, rec_len);
1633                 ((struct ext4_dir_entry_2 *) to)->rec_len =
1634                                 ext4_rec_len_to_disk(rec_len, blocksize);
1635                 de->inode = 0;
1636                 map++;
1637                 to += rec_len;
1638         }
1639         return (struct ext4_dir_entry_2 *) (to - rec_len);
1640 }
1641
1642 /*
1643  * Compact each dir entry in the range to the minimal rec_len.
1644  * Returns pointer to last entry in range.
1645  */
1646 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize)
1647 {
1648         struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
1649         unsigned rec_len = 0;
1650
1651         prev = to = de;
1652         while ((char*)de < base + blocksize) {
1653                 next = ext4_next_entry(de, blocksize);
1654                 if (de->inode && de->name_len) {
1655                         rec_len = EXT4_DIR_REC_LEN(de->name_len);
1656                         if (de > to)
1657                                 memmove(to, de, rec_len);
1658                         to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
1659                         prev = to;
1660                         to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
1661                 }
1662                 de = next;
1663         }
1664         return prev;
1665 }
1666
1667 /*
1668  * Split a full leaf block to make room for a new dir entry.
1669  * Allocate a new block, and move entries so that they are approx. equally full.
1670  * Returns pointer to de in block into which the new entry will be inserted.
1671  */
1672 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
1673                         struct buffer_head **bh,struct dx_frame *frame,
1674                         struct dx_hash_info *hinfo)
1675 {
1676         unsigned blocksize = dir->i_sb->s_blocksize;
1677         unsigned count, continued;
1678         struct buffer_head *bh2;
1679         ext4_lblk_t newblock;
1680         u32 hash2;
1681         struct dx_map_entry *map;
1682         char *data1 = (*bh)->b_data, *data2;
1683         unsigned split, move, size;
1684         struct ext4_dir_entry_2 *de = NULL, *de2;
1685         struct ext4_dir_entry_tail *t;
1686         int     csum_size = 0;
1687         int     err = 0, i;
1688
1689         if (ext4_has_metadata_csum(dir->i_sb))
1690                 csum_size = sizeof(struct ext4_dir_entry_tail);
1691
1692         bh2 = ext4_append(handle, dir, &newblock);
1693         if (IS_ERR(bh2)) {
1694                 brelse(*bh);
1695                 *bh = NULL;
1696                 return (struct ext4_dir_entry_2 *) bh2;
1697         }
1698
1699         BUFFER_TRACE(*bh, "get_write_access");
1700         err = ext4_journal_get_write_access(handle, *bh);
1701         if (err)
1702                 goto journal_error;
1703
1704         BUFFER_TRACE(frame->bh, "get_write_access");
1705         err = ext4_journal_get_write_access(handle, frame->bh);
1706         if (err)
1707                 goto journal_error;
1708
1709         data2 = bh2->b_data;
1710
1711         /* create map in the end of data2 block */
1712         map = (struct dx_map_entry *) (data2 + blocksize);
1713         count = dx_make_map(dir, (struct ext4_dir_entry_2 *) data1,
1714                              blocksize, hinfo, map);
1715         map -= count;
1716         dx_sort_map(map, count);
1717         /* Split the existing block in the middle, size-wise */
1718         size = 0;
1719         move = 0;
1720         for (i = count-1; i >= 0; i--) {
1721                 /* is more than half of this entry in 2nd half of the block? */
1722                 if (size + map[i].size/2 > blocksize/2)
1723                         break;
1724                 size += map[i].size;
1725                 move++;
1726         }
1727         /* map index at which we will split */
1728         split = count - move;
1729         hash2 = map[split].hash;
1730         continued = hash2 == map[split - 1].hash;
1731         dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
1732                         (unsigned long)dx_get_block(frame->at),
1733                                         hash2, split, count-split));
1734
1735         /* Fancy dance to stay within two buffers */
1736         de2 = dx_move_dirents(data1, data2, map + split, count - split,
1737                               blocksize);
1738         de = dx_pack_dirents(data1, blocksize);
1739         de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
1740                                            (char *) de,
1741                                            blocksize);
1742         de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
1743                                             (char *) de2,
1744                                             blocksize);
1745         if (csum_size) {
1746                 t = EXT4_DIRENT_TAIL(data2, blocksize);
1747                 initialize_dirent_tail(t, blocksize);
1748
1749                 t = EXT4_DIRENT_TAIL(data1, blocksize);
1750                 initialize_dirent_tail(t, blocksize);
1751         }
1752
1753         dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data1,
1754                         blocksize, 1));
1755         dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data2,
1756                         blocksize, 1));
1757
1758         /* Which block gets the new entry? */
1759         if (hinfo->hash >= hash2) {
1760                 swap(*bh, bh2);
1761                 de = de2;
1762         }
1763         dx_insert_block(frame, hash2 + continued, newblock);
1764         err = ext4_handle_dirty_dirent_node(handle, dir, bh2);
1765         if (err)
1766                 goto journal_error;
1767         err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
1768         if (err)
1769                 goto journal_error;
1770         brelse(bh2);
1771         dxtrace(dx_show_index("frame", frame->entries));
1772         return de;
1773
1774 journal_error:
1775         brelse(*bh);
1776         brelse(bh2);
1777         *bh = NULL;
1778         ext4_std_error(dir->i_sb, err);
1779         return ERR_PTR(err);
1780 }
1781
1782 int ext4_find_dest_de(struct inode *dir, struct inode *inode,
1783                       struct buffer_head *bh,
1784                       void *buf, int buf_size,
1785                       struct ext4_filename *fname,
1786                       struct ext4_dir_entry_2 **dest_de)
1787 {
1788         struct ext4_dir_entry_2 *de;
1789         unsigned short reclen = EXT4_DIR_REC_LEN(fname_len(fname));
1790         int nlen, rlen;
1791         unsigned int offset = 0;
1792         char *top;
1793
1794         de = (struct ext4_dir_entry_2 *)buf;
1795         top = buf + buf_size - reclen;
1796         while ((char *) de <= top) {
1797                 if (ext4_check_dir_entry(dir, NULL, de, bh,
1798                                          buf, buf_size, offset))
1799                         return -EFSCORRUPTED;
1800                 if (ext4_match(fname, de))
1801                         return -EEXIST;
1802                 nlen = EXT4_DIR_REC_LEN(de->name_len);
1803                 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
1804                 if ((de->inode ? rlen - nlen : rlen) >= reclen)
1805                         break;
1806                 de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
1807                 offset += rlen;
1808         }
1809         if ((char *) de > top)
1810                 return -ENOSPC;
1811
1812         *dest_de = de;
1813         return 0;
1814 }
1815
1816 void ext4_insert_dentry(struct inode *inode,
1817                         struct ext4_dir_entry_2 *de,
1818                         int buf_size,
1819                         struct ext4_filename *fname)
1820 {
1821
1822         int nlen, rlen;
1823
1824         nlen = EXT4_DIR_REC_LEN(de->name_len);
1825         rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
1826         if (de->inode) {
1827                 struct ext4_dir_entry_2 *de1 =
1828                         (struct ext4_dir_entry_2 *)((char *)de + nlen);
1829                 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, buf_size);
1830                 de->rec_len = ext4_rec_len_to_disk(nlen, buf_size);
1831                 de = de1;
1832         }
1833         de->file_type = EXT4_FT_UNKNOWN;
1834         de->inode = cpu_to_le32(inode->i_ino);
1835         ext4_set_de_type(inode->i_sb, de, inode->i_mode);
1836         de->name_len = fname_len(fname);
1837         memcpy(de->name, fname_name(fname), fname_len(fname));
1838 }
1839
1840 /*
1841  * Add a new entry into a directory (leaf) block.  If de is non-NULL,
1842  * it points to a directory entry which is guaranteed to be large
1843  * enough for new directory entry.  If de is NULL, then
1844  * add_dirent_to_buf will attempt search the directory block for
1845  * space.  It will return -ENOSPC if no space is available, and -EIO
1846  * and -EEXIST if directory entry already exists.
1847  */
1848 static int add_dirent_to_buf(handle_t *handle, struct ext4_filename *fname,
1849                              struct inode *dir,
1850                              struct inode *inode, struct ext4_dir_entry_2 *de,
1851                              struct buffer_head *bh)
1852 {
1853         unsigned int    blocksize = dir->i_sb->s_blocksize;
1854         int             csum_size = 0;
1855         int             err;
1856
1857         if (ext4_has_metadata_csum(inode->i_sb))
1858                 csum_size = sizeof(struct ext4_dir_entry_tail);
1859
1860         if (!de) {
1861                 err = ext4_find_dest_de(dir, inode, bh, bh->b_data,
1862                                         blocksize - csum_size, fname, &de);
1863                 if (err)
1864                         return err;
1865         }
1866         BUFFER_TRACE(bh, "get_write_access");
1867         err = ext4_journal_get_write_access(handle, bh);
1868         if (err) {
1869                 ext4_std_error(dir->i_sb, err);
1870                 return err;
1871         }
1872
1873         /* By now the buffer is marked for journaling */
1874         ext4_insert_dentry(inode, de, blocksize, fname);
1875
1876         /*
1877          * XXX shouldn't update any times until successful
1878          * completion of syscall, but too many callers depend
1879          * on this.
1880          *
1881          * XXX similarly, too many callers depend on
1882          * ext4_new_inode() setting the times, but error
1883          * recovery deletes the inode, so the worst that can
1884          * happen is that the times are slightly out of date
1885          * and/or different from the directory change time.
1886          */
1887         dir->i_mtime = dir->i_ctime = current_time(dir);
1888         ext4_update_dx_flag(dir);
1889         inode_inc_iversion(dir);
1890         ext4_mark_inode_dirty(handle, dir);
1891         BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1892         err = ext4_handle_dirty_dirent_node(handle, dir, bh);
1893         if (err)
1894                 ext4_std_error(dir->i_sb, err);
1895         return 0;
1896 }
1897
1898 /*
1899  * This converts a one block unindexed directory to a 3 block indexed
1900  * directory, and adds the dentry to the indexed directory.
1901  */
1902 static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname,
1903                             struct inode *dir,
1904                             struct inode *inode, struct buffer_head *bh)
1905 {
1906         struct buffer_head *bh2;
1907         struct dx_root  *root;
1908         struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
1909         struct dx_entry *entries;
1910         struct ext4_dir_entry_2 *de, *de2;
1911         struct ext4_dir_entry_tail *t;
1912         char            *data1, *top;
1913         unsigned        len;
1914         int             retval;
1915         unsigned        blocksize;
1916         ext4_lblk_t  block;
1917         struct fake_dirent *fde;
1918         int csum_size = 0;
1919
1920         if (ext4_has_metadata_csum(inode->i_sb))
1921                 csum_size = sizeof(struct ext4_dir_entry_tail);
1922
1923         blocksize =  dir->i_sb->s_blocksize;
1924         dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
1925         BUFFER_TRACE(bh, "get_write_access");
1926         retval = ext4_journal_get_write_access(handle, bh);
1927         if (retval) {
1928                 ext4_std_error(dir->i_sb, retval);
1929                 brelse(bh);
1930                 return retval;
1931         }
1932         root = (struct dx_root *) bh->b_data;
1933
1934         /* The 0th block becomes the root, move the dirents out */
1935         fde = &root->dotdot;
1936         de = (struct ext4_dir_entry_2 *)((char *)fde +
1937                 ext4_rec_len_from_disk(fde->rec_len, blocksize));
1938         if ((char *) de >= (((char *) root) + blocksize)) {
1939                 EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
1940                 brelse(bh);
1941                 return -EFSCORRUPTED;
1942         }
1943         len = ((char *) root) + (blocksize - csum_size) - (char *) de;
1944
1945         /* Allocate new block for the 0th block's dirents */
1946         bh2 = ext4_append(handle, dir, &block);
1947         if (IS_ERR(bh2)) {
1948                 brelse(bh);
1949                 return PTR_ERR(bh2);
1950         }
1951         ext4_set_inode_flag(dir, EXT4_INODE_INDEX);
1952         data1 = bh2->b_data;
1953
1954         memcpy (data1, de, len);
1955         de = (struct ext4_dir_entry_2 *) data1;
1956         top = data1 + len;
1957         while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
1958                 de = de2;
1959         de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
1960                                            (char *) de,
1961                                            blocksize);
1962
1963         if (csum_size) {
1964                 t = EXT4_DIRENT_TAIL(data1, blocksize);
1965                 initialize_dirent_tail(t, blocksize);
1966         }
1967
1968         /* Initialize the root; the dot dirents already exist */
1969         de = (struct ext4_dir_entry_2 *) (&root->dotdot);
1970         de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
1971                                            blocksize);
1972         memset (&root->info, 0, sizeof(root->info));
1973         root->info.info_length = sizeof(root->info);
1974         root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
1975         entries = root->entries;
1976         dx_set_block(entries, 1);
1977         dx_set_count(entries, 1);
1978         dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
1979
1980         /* Initialize as for dx_probe */
1981         fname->hinfo.hash_version = root->info.hash_version;
1982         if (fname->hinfo.hash_version <= DX_HASH_TEA)
1983                 fname->hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
1984         fname->hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
1985         ext4fs_dirhash(fname_name(fname), fname_len(fname), &fname->hinfo);
1986
1987         memset(frames, 0, sizeof(frames));
1988         frame = frames;
1989         frame->entries = entries;
1990         frame->at = entries;
1991         frame->bh = bh;
1992
1993         retval = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
1994         if (retval)
1995                 goto out_frames;        
1996         retval = ext4_handle_dirty_dirent_node(handle, dir, bh2);
1997         if (retval)
1998                 goto out_frames;        
1999
2000         de = do_split(handle,dir, &bh2, frame, &fname->hinfo);
2001         if (IS_ERR(de)) {
2002                 retval = PTR_ERR(de);
2003                 goto out_frames;
2004         }
2005
2006         retval = add_dirent_to_buf(handle, fname, dir, inode, de, bh2);
2007 out_frames:
2008         /*
2009          * Even if the block split failed, we have to properly write
2010          * out all the changes we did so far. Otherwise we can end up
2011          * with corrupted filesystem.
2012          */
2013         if (retval)
2014                 ext4_mark_inode_dirty(handle, dir);
2015         dx_release(frames);
2016         brelse(bh2);
2017         return retval;
2018 }
2019
2020 /*
2021  *      ext4_add_entry()
2022  *
2023  * adds a file entry to the specified directory, using the same
2024  * semantics as ext4_find_entry(). It returns NULL if it failed.
2025  *
2026  * NOTE!! The inode part of 'de' is left at 0 - which means you
2027  * may not sleep between calling this and putting something into
2028  * the entry, as someone else might have used it while you slept.
2029  */
2030 static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
2031                           struct inode *inode)
2032 {
2033         struct inode *dir = d_inode(dentry->d_parent);
2034         struct buffer_head *bh = NULL;
2035         struct ext4_dir_entry_2 *de;
2036         struct ext4_dir_entry_tail *t;
2037         struct super_block *sb;
2038         struct ext4_filename fname;
2039         int     retval;
2040         int     dx_fallback=0;
2041         unsigned blocksize;
2042         ext4_lblk_t block, blocks;
2043         int     csum_size = 0;
2044
2045         if (ext4_has_metadata_csum(inode->i_sb))
2046                 csum_size = sizeof(struct ext4_dir_entry_tail);
2047
2048         sb = dir->i_sb;
2049         blocksize = sb->s_blocksize;
2050         if (!dentry->d_name.len)
2051                 return -EINVAL;
2052
2053         retval = ext4_fname_setup_filename(dir, &dentry->d_name, 0, &fname);
2054         if (retval)
2055                 return retval;
2056
2057         if (ext4_has_inline_data(dir)) {
2058                 retval = ext4_try_add_inline_entry(handle, &fname, dir, inode);
2059                 if (retval < 0)
2060                         goto out;
2061                 if (retval == 1) {
2062                         retval = 0;
2063                         goto out;
2064                 }
2065         }
2066
2067         if (is_dx(dir)) {
2068                 retval = ext4_dx_add_entry(handle, &fname, dir, inode);
2069                 if (!retval || (retval != ERR_BAD_DX_DIR))
2070                         goto out;
2071                 ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
2072                 dx_fallback++;
2073                 ext4_mark_inode_dirty(handle, dir);
2074         }
2075         blocks = dir->i_size >> sb->s_blocksize_bits;
2076         for (block = 0; block < blocks; block++) {
2077                 bh = ext4_read_dirblock(dir, block, DIRENT);
2078                 if (IS_ERR(bh)) {
2079                         retval = PTR_ERR(bh);
2080                         bh = NULL;
2081                         goto out;
2082                 }
2083                 retval = add_dirent_to_buf(handle, &fname, dir, inode,
2084                                            NULL, bh);
2085                 if (retval != -ENOSPC)
2086                         goto out;
2087
2088                 if (blocks == 1 && !dx_fallback &&
2089                     ext4_has_feature_dir_index(sb)) {
2090                         retval = make_indexed_dir(handle, &fname, dir,
2091                                                   inode, bh);
2092                         bh = NULL; /* make_indexed_dir releases bh */
2093                         goto out;
2094                 }
2095                 brelse(bh);
2096         }
2097         bh = ext4_append(handle, dir, &block);
2098         if (IS_ERR(bh)) {
2099                 retval = PTR_ERR(bh);
2100                 bh = NULL;
2101                 goto out;
2102         }
2103         de = (struct ext4_dir_entry_2 *) bh->b_data;
2104         de->inode = 0;
2105         de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize);
2106
2107         if (csum_size) {
2108                 t = EXT4_DIRENT_TAIL(bh->b_data, blocksize);
2109                 initialize_dirent_tail(t, blocksize);
2110         }
2111
2112         retval = add_dirent_to_buf(handle, &fname, dir, inode, de, bh);
2113 out:
2114         ext4_fname_free_filename(&fname);
2115         brelse(bh);
2116         if (retval == 0)
2117                 ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY);
2118         return retval;
2119 }
2120
2121 /*
2122  * Returns 0 for success, or a negative error value
2123  */
2124 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
2125                              struct inode *dir, struct inode *inode)
2126 {
2127         struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
2128         struct dx_entry *entries, *at;
2129         struct buffer_head *bh;
2130         struct super_block *sb = dir->i_sb;
2131         struct ext4_dir_entry_2 *de;
2132         int restart;
2133         int err;
2134
2135 again:
2136         restart = 0;
2137         frame = dx_probe(fname, dir, NULL, frames);
2138         if (IS_ERR(frame))
2139                 return PTR_ERR(frame);
2140         entries = frame->entries;
2141         at = frame->at;
2142         bh = ext4_read_dirblock(dir, dx_get_block(frame->at), DIRENT);
2143         if (IS_ERR(bh)) {
2144                 err = PTR_ERR(bh);
2145                 bh = NULL;
2146                 goto cleanup;
2147         }
2148
2149         BUFFER_TRACE(bh, "get_write_access");
2150         err = ext4_journal_get_write_access(handle, bh);
2151         if (err)
2152                 goto journal_error;
2153
2154         err = add_dirent_to_buf(handle, fname, dir, inode, NULL, bh);
2155         if (err != -ENOSPC)
2156                 goto cleanup;
2157
2158         err = 0;
2159         /* Block full, should compress but for now just split */
2160         dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
2161                        dx_get_count(entries), dx_get_limit(entries)));
2162         /* Need to split index? */
2163         if (dx_get_count(entries) == dx_get_limit(entries)) {
2164                 ext4_lblk_t newblock;
2165                 int levels = frame - frames + 1;
2166                 unsigned int icount;
2167                 int add_level = 1;
2168                 struct dx_entry *entries2;
2169                 struct dx_node *node2;
2170                 struct buffer_head *bh2;
2171
2172                 while (frame > frames) {
2173                         if (dx_get_count((frame - 1)->entries) <
2174                             dx_get_limit((frame - 1)->entries)) {
2175                                 add_level = 0;
2176                                 break;
2177                         }
2178                         frame--; /* split higher index block */
2179                         at = frame->at;
2180                         entries = frame->entries;
2181                         restart = 1;
2182                 }
2183                 if (add_level && levels == ext4_dir_htree_level(sb)) {
2184                         ext4_warning(sb, "Directory (ino: %lu) index full, "
2185                                          "reach max htree level :%d",
2186                                          dir->i_ino, levels);
2187                         if (ext4_dir_htree_level(sb) < EXT4_HTREE_LEVEL) {
2188                                 ext4_warning(sb, "Large directory feature is "
2189                                                  "not enabled on this "
2190                                                  "filesystem");
2191                         }
2192                         err = -ENOSPC;
2193                         goto cleanup;
2194                 }
2195                 icount = dx_get_count(entries);
2196                 bh2 = ext4_append(handle, dir, &newblock);
2197                 if (IS_ERR(bh2)) {
2198                         err = PTR_ERR(bh2);
2199                         goto cleanup;
2200                 }
2201                 node2 = (struct dx_node *)(bh2->b_data);
2202                 entries2 = node2->entries;
2203                 memset(&node2->fake, 0, sizeof(struct fake_dirent));
2204                 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
2205                                                            sb->s_blocksize);
2206                 BUFFER_TRACE(frame->bh, "get_write_access");
2207                 err = ext4_journal_get_write_access(handle, frame->bh);
2208                 if (err)
2209                         goto journal_error;
2210                 if (!add_level) {
2211                         unsigned icount1 = icount/2, icount2 = icount - icount1;
2212                         unsigned hash2 = dx_get_hash(entries + icount1);
2213                         dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
2214                                        icount1, icount2));
2215
2216                         BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
2217                         err = ext4_journal_get_write_access(handle,
2218                                                              (frame - 1)->bh);
2219                         if (err)
2220                                 goto journal_error;
2221
2222                         memcpy((char *) entries2, (char *) (entries + icount1),
2223                                icount2 * sizeof(struct dx_entry));
2224                         dx_set_count(entries, icount1);
2225                         dx_set_count(entries2, icount2);
2226                         dx_set_limit(entries2, dx_node_limit(dir));
2227
2228                         /* Which index block gets the new entry? */
2229                         if (at - entries >= icount1) {
2230                                 frame->at = at = at - entries - icount1 + entries2;
2231                                 frame->entries = entries = entries2;
2232                                 swap(frame->bh, bh2);
2233                         }
2234                         dx_insert_block((frame - 1), hash2, newblock);
2235                         dxtrace(dx_show_index("node", frame->entries));
2236                         dxtrace(dx_show_index("node",
2237                                ((struct dx_node *) bh2->b_data)->entries));
2238                         err = ext4_handle_dirty_dx_node(handle, dir, bh2);
2239                         if (err)
2240                                 goto journal_error;
2241                         brelse (bh2);
2242                         err = ext4_handle_dirty_dx_node(handle, dir,
2243                                                    (frame - 1)->bh);
2244                         if (err)
2245                                 goto journal_error;
2246                         if (restart) {
2247                                 err = ext4_handle_dirty_dx_node(handle, dir,
2248                                                            frame->bh);
2249                                 goto journal_error;
2250                         }
2251                 } else {
2252                         struct dx_root *dxroot;
2253                         memcpy((char *) entries2, (char *) entries,
2254                                icount * sizeof(struct dx_entry));
2255                         dx_set_limit(entries2, dx_node_limit(dir));
2256
2257                         /* Set up root */
2258                         dx_set_count(entries, 1);
2259                         dx_set_block(entries + 0, newblock);
2260                         dxroot = (struct dx_root *)frames[0].bh->b_data;
2261                         dxroot->info.indirect_levels += 1;
2262                         dxtrace(printk(KERN_DEBUG
2263                                        "Creating %d level index...\n",
2264                                        dxroot->info.indirect_levels));
2265                         err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
2266                         if (err)
2267                                 goto journal_error;
2268                         err = ext4_handle_dirty_dx_node(handle, dir, bh2);
2269                         brelse(bh2);
2270                         restart = 1;
2271                         goto journal_error;
2272                 }
2273         }
2274         de = do_split(handle, dir, &bh, frame, &fname->hinfo);
2275         if (IS_ERR(de)) {
2276                 err = PTR_ERR(de);
2277                 goto cleanup;
2278         }
2279         err = add_dirent_to_buf(handle, fname, dir, inode, de, bh);
2280         goto cleanup;
2281
2282 journal_error:
2283         ext4_std_error(dir->i_sb, err); /* this is a no-op if err == 0 */
2284 cleanup:
2285         brelse(bh);
2286         dx_release(frames);
2287         /* @restart is true means htree-path has been changed, we need to
2288          * repeat dx_probe() to find out valid htree-path
2289          */
2290         if (restart && err == 0)
2291                 goto again;
2292         return err;
2293 }
2294
2295 /*
2296  * ext4_generic_delete_entry deletes a directory entry by merging it
2297  * with the previous entry
2298  */
2299 int ext4_generic_delete_entry(handle_t *handle,
2300                               struct inode *dir,
2301                               struct ext4_dir_entry_2 *de_del,
2302                               struct buffer_head *bh,
2303                               void *entry_buf,
2304                               int buf_size,
2305                               int csum_size)
2306 {
2307         struct ext4_dir_entry_2 *de, *pde;
2308         unsigned int blocksize = dir->i_sb->s_blocksize;
2309         int i;
2310
2311         i = 0;
2312         pde = NULL;
2313         de = (struct ext4_dir_entry_2 *)entry_buf;
2314         while (i < buf_size - csum_size) {
2315                 if (ext4_check_dir_entry(dir, NULL, de, bh,
2316                                          bh->b_data, bh->b_size, i))
2317                         return -EFSCORRUPTED;
2318                 if (de == de_del)  {
2319                         if (pde)
2320                                 pde->rec_len = ext4_rec_len_to_disk(
2321                                         ext4_rec_len_from_disk(pde->rec_len,
2322                                                                blocksize) +
2323                                         ext4_rec_len_from_disk(de->rec_len,
2324                                                                blocksize),
2325                                         blocksize);
2326                         else
2327                                 de->inode = 0;
2328                         inode_inc_iversion(dir);
2329                         return 0;
2330                 }
2331                 i += ext4_rec_len_from_disk(de->rec_len, blocksize);
2332                 pde = de;
2333                 de = ext4_next_entry(de, blocksize);
2334         }
2335         return -ENOENT;
2336 }
2337
2338 static int ext4_delete_entry(handle_t *handle,
2339                              struct inode *dir,
2340                              struct ext4_dir_entry_2 *de_del,
2341                              struct buffer_head *bh)
2342 {
2343         int err, csum_size = 0;
2344
2345         if (ext4_has_inline_data(dir)) {
2346                 int has_inline_data = 1;
2347                 err = ext4_delete_inline_entry(handle, dir, de_del, bh,
2348                                                &has_inline_data);
2349                 if (has_inline_data)
2350                         return err;
2351         }
2352
2353         if (ext4_has_metadata_csum(dir->i_sb))
2354                 csum_size = sizeof(struct ext4_dir_entry_tail);
2355
2356         BUFFER_TRACE(bh, "get_write_access");
2357         err = ext4_journal_get_write_access(handle, bh);
2358         if (unlikely(err))
2359                 goto out;
2360
2361         err = ext4_generic_delete_entry(handle, dir, de_del,
2362                                         bh, bh->b_data,
2363                                         dir->i_sb->s_blocksize, csum_size);
2364         if (err)
2365                 goto out;
2366
2367         BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
2368         err = ext4_handle_dirty_dirent_node(handle, dir, bh);
2369         if (unlikely(err))
2370                 goto out;
2371
2372         return 0;
2373 out:
2374         if (err != -ENOENT)
2375                 ext4_std_error(dir->i_sb, err);
2376         return err;
2377 }
2378
2379 /*
2380  * Set directory link count to 1 if nlinks > EXT4_LINK_MAX, or if nlinks == 2
2381  * since this indicates that nlinks count was previously 1 to avoid overflowing
2382  * the 16-bit i_links_count field on disk.  Directories with i_nlink == 1 mean
2383  * that subdirectory link counts are not being maintained accurately.
2384  *
2385  * The caller has already checked for i_nlink overflow in case the DIR_LINK
2386  * feature is not enabled and returned -EMLINK.  The is_dx() check is a proxy
2387  * for checking S_ISDIR(inode) (since the INODE_INDEX feature will not be set
2388  * on regular files) and to avoid creating huge/slow non-HTREE directories.
2389  */
2390 static void ext4_inc_count(handle_t *handle, struct inode *inode)
2391 {
2392         inc_nlink(inode);
2393         if (is_dx(inode) &&
2394             (inode->i_nlink > EXT4_LINK_MAX || inode->i_nlink == 2))
2395                 set_nlink(inode, 1);
2396 }
2397
2398 /*
2399  * If a directory had nlink == 1, then we should let it be 1. This indicates
2400  * directory has >EXT4_LINK_MAX subdirs.
2401  */
2402 static void ext4_dec_count(handle_t *handle, struct inode *inode)
2403 {
2404         if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
2405                 drop_nlink(inode);
2406 }
2407
2408
2409 static int ext4_add_nondir(handle_t *handle,
2410                 struct dentry *dentry, struct inode *inode)
2411 {
2412         int err = ext4_add_entry(handle, dentry, inode);
2413         if (!err) {
2414                 ext4_mark_inode_dirty(handle, inode);
2415                 d_instantiate_new(dentry, inode);
2416                 return 0;
2417         }
2418         drop_nlink(inode);
2419         unlock_new_inode(inode);
2420         iput(inode);
2421         return err;
2422 }
2423
2424 /*
2425  * By the time this is called, we already have created
2426  * the directory cache entry for the new file, but it
2427  * is so far negative - it has no inode.
2428  *
2429  * If the create succeeds, we fill in the inode information
2430  * with d_instantiate().
2431  */
2432 static int ext4_create(struct inode *dir, struct dentry *dentry, umode_t mode,
2433                        bool excl)
2434 {
2435         handle_t *handle;
2436         struct inode *inode;
2437         int err, credits, retries = 0;
2438
2439         err = dquot_initialize(dir);
2440         if (err)
2441                 return err;
2442
2443         credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2444                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2445 retry:
2446         inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
2447                                             NULL, EXT4_HT_DIR, credits);
2448         handle = ext4_journal_current_handle();
2449         err = PTR_ERR(inode);
2450         if (!IS_ERR(inode)) {
2451                 inode->i_op = &ext4_file_inode_operations;
2452                 inode->i_fop = &ext4_file_operations;
2453                 ext4_set_aops(inode);
2454                 err = ext4_add_nondir(handle, dentry, inode);
2455                 if (!err && IS_DIRSYNC(dir))
2456                         ext4_handle_sync(handle);
2457         }
2458         if (handle)
2459                 ext4_journal_stop(handle);
2460         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2461                 goto retry;
2462         return err;
2463 }
2464
2465 static int ext4_mknod(struct inode *dir, struct dentry *dentry,
2466                       umode_t mode, dev_t rdev)
2467 {
2468         handle_t *handle;
2469         struct inode *inode;
2470         int err, credits, retries = 0;
2471
2472         err = dquot_initialize(dir);
2473         if (err)
2474                 return err;
2475
2476         credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2477                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2478 retry:
2479         inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
2480                                             NULL, EXT4_HT_DIR, credits);
2481         handle = ext4_journal_current_handle();
2482         err = PTR_ERR(inode);
2483         if (!IS_ERR(inode)) {
2484                 init_special_inode(inode, inode->i_mode, rdev);
2485                 inode->i_op = &ext4_special_inode_operations;
2486                 err = ext4_add_nondir(handle, dentry, inode);
2487                 if (!err && IS_DIRSYNC(dir))
2488                         ext4_handle_sync(handle);
2489         }
2490         if (handle)
2491                 ext4_journal_stop(handle);
2492         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2493                 goto retry;
2494         return err;
2495 }
2496
2497 static int ext4_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
2498 {
2499         handle_t *handle;
2500         struct inode *inode;
2501         int err, retries = 0;
2502
2503         err = dquot_initialize(dir);
2504         if (err)
2505                 return err;
2506
2507 retry:
2508         inode = ext4_new_inode_start_handle(dir, mode,
2509                                             NULL, 0, NULL,
2510                                             EXT4_HT_DIR,
2511                         EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
2512                           4 + EXT4_XATTR_TRANS_BLOCKS);
2513         handle = ext4_journal_current_handle();
2514         err = PTR_ERR(inode);
2515         if (!IS_ERR(inode)) {
2516                 inode->i_op = &ext4_file_inode_operations;
2517                 inode->i_fop = &ext4_file_operations;
2518                 ext4_set_aops(inode);
2519                 d_tmpfile(dentry, inode);
2520                 err = ext4_orphan_add(handle, inode);
2521                 if (err)
2522                         goto err_unlock_inode;
2523                 mark_inode_dirty(inode);
2524                 unlock_new_inode(inode);
2525         }
2526         if (handle)
2527                 ext4_journal_stop(handle);
2528         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2529                 goto retry;
2530         return err;
2531 err_unlock_inode:
2532         ext4_journal_stop(handle);
2533         unlock_new_inode(inode);
2534         return err;
2535 }
2536
2537 struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
2538                           struct ext4_dir_entry_2 *de,
2539                           int blocksize, int csum_size,
2540                           unsigned int parent_ino, int dotdot_real_len)
2541 {
2542         de->inode = cpu_to_le32(inode->i_ino);
2543         de->name_len = 1;
2544         de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
2545                                            blocksize);
2546         strcpy(de->name, ".");
2547         ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2548
2549         de = ext4_next_entry(de, blocksize);
2550         de->inode = cpu_to_le32(parent_ino);
2551         de->name_len = 2;
2552         if (!dotdot_real_len)
2553                 de->rec_len = ext4_rec_len_to_disk(blocksize -
2554                                         (csum_size + EXT4_DIR_REC_LEN(1)),
2555                                         blocksize);
2556         else
2557                 de->rec_len = ext4_rec_len_to_disk(
2558                                 EXT4_DIR_REC_LEN(de->name_len), blocksize);
2559         strcpy(de->name, "..");
2560         ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2561
2562         return ext4_next_entry(de, blocksize);
2563 }
2564
2565 static int ext4_init_new_dir(handle_t *handle, struct inode *dir,
2566                              struct inode *inode)
2567 {
2568         struct buffer_head *dir_block = NULL;
2569         struct ext4_dir_entry_2 *de;
2570         struct ext4_dir_entry_tail *t;
2571         ext4_lblk_t block = 0;
2572         unsigned int blocksize = dir->i_sb->s_blocksize;
2573         int csum_size = 0;
2574         int err;
2575
2576         if (ext4_has_metadata_csum(dir->i_sb))
2577                 csum_size = sizeof(struct ext4_dir_entry_tail);
2578
2579         if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
2580                 err = ext4_try_create_inline_dir(handle, dir, inode);
2581                 if (err < 0 && err != -ENOSPC)
2582                         goto out;
2583                 if (!err)
2584                         goto out;
2585         }
2586
2587         inode->i_size = 0;
2588         dir_block = ext4_append(handle, inode, &block);
2589         if (IS_ERR(dir_block))
2590                 return PTR_ERR(dir_block);
2591         de = (struct ext4_dir_entry_2 *)dir_block->b_data;
2592         ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0);
2593         set_nlink(inode, 2);
2594         if (csum_size) {
2595                 t = EXT4_DIRENT_TAIL(dir_block->b_data, blocksize);
2596                 initialize_dirent_tail(t, blocksize);
2597         }
2598
2599         BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
2600         err = ext4_handle_dirty_dirent_node(handle, inode, dir_block);
2601         if (err)
2602                 goto out;
2603         set_buffer_verified(dir_block);
2604 out:
2605         brelse(dir_block);
2606         return err;
2607 }
2608
2609 static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
2610 {
2611         handle_t *handle;
2612         struct inode *inode;
2613         int err, credits, retries = 0;
2614
2615         if (EXT4_DIR_LINK_MAX(dir))
2616                 return -EMLINK;
2617
2618         err = dquot_initialize(dir);
2619         if (err)
2620                 return err;
2621
2622         credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2623                    EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2624 retry:
2625         inode = ext4_new_inode_start_handle(dir, S_IFDIR | mode,
2626                                             &dentry->d_name,
2627                                             0, NULL, EXT4_HT_DIR, credits);
2628         handle = ext4_journal_current_handle();
2629         err = PTR_ERR(inode);
2630         if (IS_ERR(inode))
2631                 goto out_stop;
2632
2633         inode->i_op = &ext4_dir_inode_operations;
2634         inode->i_fop = &ext4_dir_operations;
2635         err = ext4_init_new_dir(handle, dir, inode);
2636         if (err)
2637                 goto out_clear_inode;
2638         err = ext4_mark_inode_dirty(handle, inode);
2639         if (!err)
2640                 err = ext4_add_entry(handle, dentry, inode);
2641         if (err) {
2642 out_clear_inode:
2643                 clear_nlink(inode);
2644                 unlock_new_inode(inode);
2645                 ext4_mark_inode_dirty(handle, inode);
2646                 iput(inode);
2647                 goto out_stop;
2648         }
2649         ext4_inc_count(handle, dir);
2650         ext4_update_dx_flag(dir);
2651         err = ext4_mark_inode_dirty(handle, dir);
2652         if (err)
2653                 goto out_clear_inode;
2654         d_instantiate_new(dentry, inode);
2655         if (IS_DIRSYNC(dir))
2656                 ext4_handle_sync(handle);
2657
2658 out_stop:
2659         if (handle)
2660                 ext4_journal_stop(handle);
2661         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2662                 goto retry;
2663         return err;
2664 }
2665
2666 /*
2667  * routine to check that the specified directory is empty (for rmdir)
2668  */
2669 bool ext4_empty_dir(struct inode *inode)
2670 {
2671         unsigned int offset;
2672         struct buffer_head *bh;
2673         struct ext4_dir_entry_2 *de, *de1;
2674         struct super_block *sb;
2675
2676         if (ext4_has_inline_data(inode)) {
2677                 int has_inline_data = 1;
2678                 int ret;
2679
2680                 ret = empty_inline_dir(inode, &has_inline_data);
2681                 if (has_inline_data)
2682                         return ret;
2683         }
2684
2685         sb = inode->i_sb;
2686         if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2)) {
2687                 EXT4_ERROR_INODE(inode, "invalid size");
2688                 return true;
2689         }
2690         bh = ext4_read_dirblock(inode, 0, EITHER);
2691         if (IS_ERR(bh))
2692                 return true;
2693
2694         de = (struct ext4_dir_entry_2 *) bh->b_data;
2695         de1 = ext4_next_entry(de, sb->s_blocksize);
2696         if (le32_to_cpu(de->inode) != inode->i_ino ||
2697                         le32_to_cpu(de1->inode) == 0 ||
2698                         strcmp(".", de->name) || strcmp("..", de1->name)) {
2699                 ext4_warning_inode(inode, "directory missing '.' and/or '..'");
2700                 brelse(bh);
2701                 return true;
2702         }
2703         offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) +
2704                  ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize);
2705         de = ext4_next_entry(de1, sb->s_blocksize);
2706         while (offset < inode->i_size) {
2707                 if ((void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
2708                         unsigned int lblock;
2709                         brelse(bh);
2710                         lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb);
2711                         bh = ext4_read_dirblock(inode, lblock, EITHER);
2712                         if (IS_ERR(bh))
2713                                 return true;
2714                         de = (struct ext4_dir_entry_2 *) bh->b_data;
2715                 }
2716                 if (ext4_check_dir_entry(inode, NULL, de, bh,
2717                                          bh->b_data, bh->b_size, offset)) {
2718                         de = (struct ext4_dir_entry_2 *)(bh->b_data +
2719                                                          sb->s_blocksize);
2720                         offset = (offset | (sb->s_blocksize - 1)) + 1;
2721                         continue;
2722                 }
2723                 if (le32_to_cpu(de->inode)) {
2724                         brelse(bh);
2725                         return false;
2726                 }
2727                 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
2728                 de = ext4_next_entry(de, sb->s_blocksize);
2729         }
2730         brelse(bh);
2731         return true;
2732 }
2733
2734 /*
2735  * ext4_orphan_add() links an unlinked or truncated inode into a list of
2736  * such inodes, starting at the superblock, in case we crash before the
2737  * file is closed/deleted, or in case the inode truncate spans multiple
2738  * transactions and the last transaction is not recovered after a crash.
2739  *
2740  * At filesystem recovery time, we walk this list deleting unlinked
2741  * inodes and truncating linked inodes in ext4_orphan_cleanup().
2742  *
2743  * Orphan list manipulation functions must be called under i_mutex unless
2744  * we are just creating the inode or deleting it.
2745  */
2746 int ext4_orphan_add(handle_t *handle, struct inode *inode)
2747 {
2748         struct super_block *sb = inode->i_sb;
2749         struct ext4_sb_info *sbi = EXT4_SB(sb);
2750         struct ext4_iloc iloc;
2751         int err = 0, rc;
2752         bool dirty = false;
2753
2754         if (!sbi->s_journal || is_bad_inode(inode))
2755                 return 0;
2756
2757         WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
2758                      !inode_is_locked(inode));
2759         /*
2760          * Exit early if inode already is on orphan list. This is a big speedup
2761          * since we don't have to contend on the global s_orphan_lock.
2762          */
2763         if (!list_empty(&EXT4_I(inode)->i_orphan))
2764                 return 0;
2765
2766         /*
2767          * Orphan handling is only valid for files with data blocks
2768          * being truncated, or files being unlinked. Note that we either
2769          * hold i_mutex, or the inode can not be referenced from outside,
2770          * so i_nlink should not be bumped due to race
2771          */
2772         J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2773                   S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
2774
2775         BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2776         err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2777         if (err)
2778                 goto out;
2779
2780         err = ext4_reserve_inode_write(handle, inode, &iloc);
2781         if (err)
2782                 goto out;
2783
2784         mutex_lock(&sbi->s_orphan_lock);
2785         /*
2786          * Due to previous errors inode may be already a part of on-disk
2787          * orphan list. If so skip on-disk list modification.
2788          */
2789         if (!NEXT_ORPHAN(inode) || NEXT_ORPHAN(inode) >
2790             (le32_to_cpu(sbi->s_es->s_inodes_count))) {
2791                 /* Insert this inode at the head of the on-disk orphan list */
2792                 NEXT_ORPHAN(inode) = le32_to_cpu(sbi->s_es->s_last_orphan);
2793                 sbi->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
2794                 dirty = true;
2795         }
2796         list_add(&EXT4_I(inode)->i_orphan, &sbi->s_orphan);
2797         mutex_unlock(&sbi->s_orphan_lock);
2798
2799         if (dirty) {
2800                 err = ext4_handle_dirty_super(handle, sb);
2801                 rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
2802                 if (!err)
2803                         err = rc;
2804                 if (err) {
2805                         /*
2806                          * We have to remove inode from in-memory list if
2807                          * addition to on disk orphan list failed. Stray orphan
2808                          * list entries can cause panics at unmount time.
2809                          */
2810                         mutex_lock(&sbi->s_orphan_lock);
2811                         list_del_init(&EXT4_I(inode)->i_orphan);
2812                         mutex_unlock(&sbi->s_orphan_lock);
2813                 }
2814         }
2815         jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
2816         jbd_debug(4, "orphan inode %lu will point to %d\n",
2817                         inode->i_ino, NEXT_ORPHAN(inode));
2818 out:
2819         ext4_std_error(sb, err);
2820         return err;
2821 }
2822
2823 /*
2824  * ext4_orphan_del() removes an unlinked or truncated inode from the list
2825  * of such inodes stored on disk, because it is finally being cleaned up.
2826  */
2827 int ext4_orphan_del(handle_t *handle, struct inode *inode)
2828 {
2829         struct list_head *prev;
2830         struct ext4_inode_info *ei = EXT4_I(inode);
2831         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2832         __u32 ino_next;
2833         struct ext4_iloc iloc;
2834         int err = 0;
2835
2836         if (!sbi->s_journal && !(sbi->s_mount_state & EXT4_ORPHAN_FS))
2837                 return 0;
2838
2839         WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
2840                      !inode_is_locked(inode));
2841         /* Do this quick check before taking global s_orphan_lock. */
2842         if (list_empty(&ei->i_orphan))
2843                 return 0;
2844
2845         if (handle) {
2846                 /* Grab inode buffer early before taking global s_orphan_lock */
2847                 err = ext4_reserve_inode_write(handle, inode, &iloc);
2848         }
2849
2850         mutex_lock(&sbi->s_orphan_lock);
2851         jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
2852
2853         prev = ei->i_orphan.prev;
2854         list_del_init(&ei->i_orphan);
2855
2856         /* If we're on an error path, we may not have a valid
2857          * transaction handle with which to update the orphan list on
2858          * disk, but we still need to remove the inode from the linked
2859          * list in memory. */
2860         if (!handle || err) {
2861                 mutex_unlock(&sbi->s_orphan_lock);
2862                 goto out_err;
2863         }
2864
2865         ino_next = NEXT_ORPHAN(inode);
2866         if (prev == &sbi->s_orphan) {
2867                 jbd_debug(4, "superblock will point to %u\n", ino_next);
2868                 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2869                 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2870                 if (err) {
2871                         mutex_unlock(&sbi->s_orphan_lock);
2872                         goto out_brelse;
2873                 }
2874                 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
2875                 mutex_unlock(&sbi->s_orphan_lock);
2876                 err = ext4_handle_dirty_super(handle, inode->i_sb);
2877         } else {
2878                 struct ext4_iloc iloc2;
2879                 struct inode *i_prev =
2880                         &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
2881
2882                 jbd_debug(4, "orphan inode %lu will point to %u\n",
2883                           i_prev->i_ino, ino_next);
2884                 err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
2885                 if (err) {
2886                         mutex_unlock(&sbi->s_orphan_lock);
2887                         goto out_brelse;
2888                 }
2889                 NEXT_ORPHAN(i_prev) = ino_next;
2890                 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
2891                 mutex_unlock(&sbi->s_orphan_lock);
2892         }
2893         if (err)
2894                 goto out_brelse;
2895         NEXT_ORPHAN(inode) = 0;
2896         err = ext4_mark_iloc_dirty(handle, inode, &iloc);
2897 out_err:
2898         ext4_std_error(inode->i_sb, err);
2899         return err;
2900
2901 out_brelse:
2902         brelse(iloc.bh);
2903         goto out_err;
2904 }
2905
2906 static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
2907 {
2908         int retval;
2909         struct inode *inode;
2910         struct buffer_head *bh;
2911         struct ext4_dir_entry_2 *de;
2912         handle_t *handle = NULL;
2913
2914         if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
2915                 return -EIO;
2916
2917         /* Initialize quotas before so that eventual writes go in
2918          * separate transaction */
2919         retval = dquot_initialize(dir);
2920         if (retval)
2921                 return retval;
2922         retval = dquot_initialize(d_inode(dentry));
2923         if (retval)
2924                 return retval;
2925
2926         retval = -ENOENT;
2927         bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
2928         if (IS_ERR(bh))
2929                 return PTR_ERR(bh);
2930         if (!bh)
2931                 goto end_rmdir;
2932
2933         inode = d_inode(dentry);
2934
2935         retval = -EFSCORRUPTED;
2936         if (le32_to_cpu(de->inode) != inode->i_ino)
2937                 goto end_rmdir;
2938
2939         retval = -ENOTEMPTY;
2940         if (!ext4_empty_dir(inode))
2941                 goto end_rmdir;
2942
2943         handle = ext4_journal_start(dir, EXT4_HT_DIR,
2944                                     EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
2945         if (IS_ERR(handle)) {
2946                 retval = PTR_ERR(handle);
2947                 handle = NULL;
2948                 goto end_rmdir;
2949         }
2950
2951         if (IS_DIRSYNC(dir))
2952                 ext4_handle_sync(handle);
2953
2954         retval = ext4_delete_entry(handle, dir, de, bh);
2955         if (retval)
2956                 goto end_rmdir;
2957         if (!EXT4_DIR_LINK_EMPTY(inode))
2958                 ext4_warning_inode(inode,
2959                              "empty directory '%.*s' has too many links (%u)",
2960                              dentry->d_name.len, dentry->d_name.name,
2961                              inode->i_nlink);
2962         inode_inc_iversion(inode);
2963         clear_nlink(inode);
2964         /* There's no need to set i_disksize: the fact that i_nlink is
2965          * zero will ensure that the right thing happens during any
2966          * recovery. */
2967         inode->i_size = 0;
2968         ext4_orphan_add(handle, inode);
2969         inode->i_ctime = dir->i_ctime = dir->i_mtime = current_time(inode);
2970         ext4_mark_inode_dirty(handle, inode);
2971         ext4_dec_count(handle, dir);
2972         ext4_update_dx_flag(dir);
2973         ext4_mark_inode_dirty(handle, dir);
2974
2975 end_rmdir:
2976         brelse(bh);
2977         if (handle)
2978                 ext4_journal_stop(handle);
2979         return retval;
2980 }
2981
2982 static int ext4_unlink(struct inode *dir, struct dentry *dentry)
2983 {
2984         int retval;
2985         struct inode *inode;
2986         struct buffer_head *bh;
2987         struct ext4_dir_entry_2 *de;
2988         handle_t *handle = NULL;
2989
2990         if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
2991                 return -EIO;
2992
2993         trace_ext4_unlink_enter(dir, dentry);
2994         /* Initialize quotas before so that eventual writes go
2995          * in separate transaction */
2996         retval = dquot_initialize(dir);
2997         if (retval)
2998                 return retval;
2999         retval = dquot_initialize(d_inode(dentry));
3000         if (retval)
3001                 return retval;
3002
3003         retval = -ENOENT;
3004         bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
3005         if (IS_ERR(bh))
3006                 return PTR_ERR(bh);
3007         if (!bh)
3008                 goto end_unlink;
3009
3010         inode = d_inode(dentry);
3011
3012         retval = -EFSCORRUPTED;
3013         if (le32_to_cpu(de->inode) != inode->i_ino)
3014                 goto end_unlink;
3015
3016         handle = ext4_journal_start(dir, EXT4_HT_DIR,
3017                                     EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
3018         if (IS_ERR(handle)) {
3019                 retval = PTR_ERR(handle);
3020                 handle = NULL;
3021                 goto end_unlink;
3022         }
3023
3024         if (IS_DIRSYNC(dir))
3025                 ext4_handle_sync(handle);
3026
3027         if (inode->i_nlink == 0) {
3028                 ext4_warning_inode(inode, "Deleting file '%.*s' with no links",
3029                                    dentry->d_name.len, dentry->d_name.name);
3030                 set_nlink(inode, 1);
3031         }
3032         retval = ext4_delete_entry(handle, dir, de, bh);
3033         if (retval)
3034                 goto end_unlink;
3035         dir->i_ctime = dir->i_mtime = current_time(dir);
3036         ext4_update_dx_flag(dir);
3037         ext4_mark_inode_dirty(handle, dir);
3038         drop_nlink(inode);
3039         if (!inode->i_nlink)
3040                 ext4_orphan_add(handle, inode);
3041         inode->i_ctime = current_time(inode);
3042         ext4_mark_inode_dirty(handle, inode);
3043
3044 end_unlink:
3045         brelse(bh);
3046         if (handle)
3047                 ext4_journal_stop(handle);
3048         trace_ext4_unlink_exit(dentry, retval);
3049         return retval;
3050 }
3051
3052 static int ext4_symlink(struct inode *dir,
3053                         struct dentry *dentry, const char *symname)
3054 {
3055         handle_t *handle;
3056         struct inode *inode;
3057         int err, len = strlen(symname);
3058         int credits;
3059         struct fscrypt_str disk_link;
3060
3061         if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
3062                 return -EIO;
3063
3064         err = fscrypt_prepare_symlink(dir, symname, len, dir->i_sb->s_blocksize,
3065                                       &disk_link);
3066         if (err)
3067                 return err;
3068
3069         err = dquot_initialize(dir);
3070         if (err)
3071                 return err;
3072
3073         if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
3074                 /*
3075                  * For non-fast symlinks, we just allocate inode and put it on
3076                  * orphan list in the first transaction => we need bitmap,
3077                  * group descriptor, sb, inode block, quota blocks, and
3078                  * possibly selinux xattr blocks.
3079                  */
3080                 credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
3081                           EXT4_XATTR_TRANS_BLOCKS;
3082         } else {
3083                 /*
3084                  * Fast symlink. We have to add entry to directory
3085                  * (EXT4_DATA_TRANS_BLOCKS + EXT4_INDEX_EXTRA_TRANS_BLOCKS),
3086                  * allocate new inode (bitmap, group descriptor, inode block,
3087                  * quota blocks, sb is already counted in previous macros).
3088                  */
3089                 credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3090                           EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3;
3091         }
3092
3093         inode = ext4_new_inode_start_handle(dir, S_IFLNK|S_IRWXUGO,
3094                                             &dentry->d_name, 0, NULL,
3095                                             EXT4_HT_DIR, credits);
3096         handle = ext4_journal_current_handle();
3097         if (IS_ERR(inode)) {
3098                 if (handle)
3099                         ext4_journal_stop(handle);
3100                 return PTR_ERR(inode);
3101         }
3102
3103         if (IS_ENCRYPTED(inode)) {
3104                 err = fscrypt_encrypt_symlink(inode, symname, len, &disk_link);
3105                 if (err)
3106                         goto err_drop_inode;
3107                 inode->i_op = &ext4_encrypted_symlink_inode_operations;
3108         }
3109
3110         if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
3111                 if (!IS_ENCRYPTED(inode))
3112                         inode->i_op = &ext4_symlink_inode_operations;
3113                 inode_nohighmem(inode);
3114                 ext4_set_aops(inode);
3115                 /*
3116                  * We cannot call page_symlink() with transaction started
3117                  * because it calls into ext4_write_begin() which can wait
3118                  * for transaction commit if we are running out of space
3119                  * and thus we deadlock. So we have to stop transaction now
3120                  * and restart it when symlink contents is written.
3121                  * 
3122                  * To keep fs consistent in case of crash, we have to put inode
3123                  * to orphan list in the mean time.
3124                  */
3125                 drop_nlink(inode);
3126                 err = ext4_orphan_add(handle, inode);
3127                 ext4_journal_stop(handle);
3128                 handle = NULL;
3129                 if (err)
3130                         goto err_drop_inode;
3131                 err = __page_symlink(inode, disk_link.name, disk_link.len, 1);
3132                 if (err)
3133                         goto err_drop_inode;
3134                 /*
3135                  * Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS
3136                  * + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified
3137                  */
3138                 handle = ext4_journal_start(dir, EXT4_HT_DIR,
3139                                 EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3140                                 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1);
3141                 if (IS_ERR(handle)) {
3142                         err = PTR_ERR(handle);
3143                         handle = NULL;
3144                         goto err_drop_inode;
3145                 }
3146                 set_nlink(inode, 1);
3147            &nb