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Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/evalenti/linux...
[linux/fpc-iii.git] / fs / ext4 / namei.c
blob48e4b8907826eca52a1e94e14bdfdb0fd2240c56
1 /*
2 * linux/fs/ext4/namei.c
3 *
4 * Copyright (C) 1992, 1993, 1994, 1995
5 * Remy Card (card@masi.ibp.fr)
6 * Laboratoire MASI - Institut Blaise Pascal
7 * Universite Pierre et Marie Curie (Paris VI)
8 *
9 * from
10 *
11 * linux/fs/minix/namei.c
12 *
13 * Copyright (C) 1991, 1992 Linus Torvalds
14 *
15 * Big-endian to little-endian byte-swapping/bitmaps by
16 * David S. Miller (davem@caip.rutgers.edu), 1995
17 * Directory entry file type support and forward compatibility hooks
18 * for B-tree directories by Theodore Ts'o (tytso@mit.edu), 1998
19 * Hash Tree Directory indexing (c)
20 * Daniel Phillips, 2001
21 * Hash Tree Directory indexing porting
22 * Christopher Li, 2002
23 * Hash Tree Directory indexing cleanup
24 * Theodore Ts'o, 2002
25 */
26
27 #include <linux/fs.h>
28 #include <linux/pagemap.h>
29 #include <linux/time.h>
30 #include <linux/fcntl.h>
31 #include <linux/stat.h>
32 #include <linux/string.h>
33 #include <linux/quotaops.h>
34 #include <linux/buffer_head.h>
35 #include <linux/bio.h>
36 #include "ext4.h"
37 #include "ext4_jbd2.h"
38
39 #include "xattr.h"
40 #include "acl.h"
41
42 #include <trace/events/ext4.h>
43 /*
44 * define how far ahead to read directories while searching them.
45 */
46 #define NAMEI_RA_CHUNKS 2
47 #define NAMEI_RA_BLOCKS 4
48 #define NAMEI_RA_SIZE (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS)
49
50 static struct buffer_head *ext4_append(handle_t *handle,
51 struct inode *inode,
52 ext4_lblk_t *block)
53 {
54 struct buffer_head *bh;
55 int err;
56
57 if (unlikely(EXT4_SB(inode->i_sb)->s_max_dir_size_kb &&
58 ((inode->i_size >> 10) >=
59 EXT4_SB(inode->i_sb)->s_max_dir_size_kb)))
60 return ERR_PTR(-ENOSPC);
61
62 *block = inode->i_size >> inode->i_sb->s_blocksize_bits;
63
64 bh = ext4_bread(handle, inode, *block, EXT4_GET_BLOCKS_CREATE);
65 if (IS_ERR(bh))
66 return bh;
67 inode->i_size += inode->i_sb->s_blocksize;
68 EXT4_I(inode)->i_disksize = inode->i_size;
69 BUFFER_TRACE(bh, "get_write_access");
70 err = ext4_journal_get_write_access(handle, bh);
71 if (err) {
72 brelse(bh);
73 ext4_std_error(inode->i_sb, err);
74 return ERR_PTR(err);
75 }
76 return bh;
77 }
78
79 static int ext4_dx_csum_verify(struct inode *inode,
80 struct ext4_dir_entry *dirent);
81
82 typedef enum {
83 EITHER, INDEX, DIRENT
84 } dirblock_type_t;
85
86 #define ext4_read_dirblock(inode, block, type) \
87 __ext4_read_dirblock((inode), (block), (type), __func__, __LINE__)
88
89 static struct buffer_head *__ext4_read_dirblock(struct inode *inode,
90 ext4_lblk_t block,
91 dirblock_type_t type,
92 const char *func,
93 unsigned int line)
94 {
95 struct buffer_head *bh;
96 struct ext4_dir_entry *dirent;
97 int is_dx_block = 0;
98
99 bh = ext4_bread(NULL, inode, block, 0);
100 if (IS_ERR(bh)) {
101 __ext4_warning(inode->i_sb, func, line,
102 "inode #%lu: lblock %lu: comm %s: "
103 "error %ld reading directory block",
104 inode->i_ino, (unsigned long)block,
105 current->comm, PTR_ERR(bh));
106
107 return bh;
108 }
109 if (!bh) {
110 ext4_error_inode(inode, func, line, block,
111 "Directory hole found");
112 return ERR_PTR(-EFSCORRUPTED);
113 }
114 dirent = (struct ext4_dir_entry *) bh->b_data;
115 /* Determine whether or not we have an index block */
116 if (is_dx(inode)) {
117 if (block == 0)
118 is_dx_block = 1;
119 else if (ext4_rec_len_from_disk(dirent->rec_len,
120 inode->i_sb->s_blocksize) ==
121 inode->i_sb->s_blocksize)
122 is_dx_block = 1;
123 }
124 if (!is_dx_block && type == INDEX) {
125 ext4_error_inode(inode, func, line, block,
126 "directory leaf block found instead of index block");
127 return ERR_PTR(-EFSCORRUPTED);
128 }
129 if (!ext4_has_metadata_csum(inode->i_sb) ||
130 buffer_verified(bh))
131 return bh;
132
133 /*
134 * An empty leaf block can get mistaken for a index block; for
135 * this reason, we can only check the index checksum when the
136 * caller is sure it should be an index block.
137 */
138 if (is_dx_block && type == INDEX) {
139 if (ext4_dx_csum_verify(inode, dirent))
140 set_buffer_verified(bh);
141 else {
142 ext4_error_inode(inode, func, line, block,
143 "Directory index failed checksum");
144 brelse(bh);
145 return ERR_PTR(-EFSBADCRC);
146 }
147 }
148 if (!is_dx_block) {
149 if (ext4_dirent_csum_verify(inode, dirent))
150 set_buffer_verified(bh);
151 else {
152 ext4_error_inode(inode, func, line, block,
153 "Directory block failed checksum");
154 brelse(bh);
155 return ERR_PTR(-EFSBADCRC);
156 }
157 }
158 return bh;
159 }
160
161 #ifndef assert
162 #define assert(test) J_ASSERT(test)
163 #endif
164
165 #ifdef DX_DEBUG
166 #define dxtrace(command) command
167 #else
168 #define dxtrace(command)
169 #endif
170
171 struct fake_dirent
172 {
173 __le32 inode;
174 __le16 rec_len;
175 u8 name_len;
176 u8 file_type;
177 };
178
179 struct dx_countlimit
180 {
181 __le16 limit;
182 __le16 count;
183 };
184
185 struct dx_entry
186 {
187 __le32 hash;
188 __le32 block;
189 };
190
191 /*
192 * dx_root_info is laid out so that if it should somehow get overlaid by a
193 * dirent the two low bits of the hash version will be zero. Therefore, the
194 * hash version mod 4 should never be 0. Sincerely, the paranoia department.
195 */
196
197 struct dx_root
198 {
199 struct fake_dirent dot;
200 char dot_name[4];
201 struct fake_dirent dotdot;
202 char dotdot_name[4];
203 struct dx_root_info
204 {
205 __le32 reserved_zero;
206 u8 hash_version;
207 u8 info_length; /* 8 */
208 u8 indirect_levels;
209 u8 unused_flags;
210 }
211 info;
212 struct dx_entry entries[0];
213 };
214
215 struct dx_node
216 {
217 struct fake_dirent fake;
218 struct dx_entry entries[0];
219 };
220
221
222 struct dx_frame
223 {
224 struct buffer_head *bh;
225 struct dx_entry *entries;
226 struct dx_entry *at;
227 };
228
229 struct dx_map_entry
230 {
231 u32 hash;
232 u16 offs;
233 u16 size;
234 };
235
236 /*
237 * This goes at the end of each htree block.
238 */
239 struct dx_tail {
240 u32 dt_reserved;
241 __le32 dt_checksum; /* crc32c(uuid+inum+dirblock) */
242 };
243
244 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
245 static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
246 static inline unsigned dx_get_hash(struct dx_entry *entry);
247 static void dx_set_hash(struct dx_entry *entry, unsigned value);
248 static unsigned dx_get_count(struct dx_entry *entries);
249 static unsigned dx_get_limit(struct dx_entry *entries);
250 static void dx_set_count(struct dx_entry *entries, unsigned value);
251 static void dx_set_limit(struct dx_entry *entries, unsigned value);
252 static unsigned dx_root_limit(struct inode *dir, unsigned infosize);
253 static unsigned dx_node_limit(struct inode *dir);
254 static struct dx_frame *dx_probe(struct ext4_filename *fname,
255 struct inode *dir,
256 struct dx_hash_info *hinfo,
257 struct dx_frame *frame);
258 static void dx_release(struct dx_frame *frames);
259 static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de,
260 unsigned blocksize, struct dx_hash_info *hinfo,
261 struct dx_map_entry map[]);
262 static void dx_sort_map(struct dx_map_entry *map, unsigned count);
263 static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to,
264 struct dx_map_entry *offsets, int count, unsigned blocksize);
265 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize);
266 static void dx_insert_block(struct dx_frame *frame,
267 u32 hash, ext4_lblk_t block);
268 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
269 struct dx_frame *frame,
270 struct dx_frame *frames,
271 __u32 *start_hash);
272 static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
273 struct ext4_filename *fname,
274 struct ext4_dir_entry_2 **res_dir);
275 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
276 struct inode *dir, struct inode *inode);
277
278 /* checksumming functions */
279 void initialize_dirent_tail(struct ext4_dir_entry_tail *t,
280 unsigned int blocksize)
281 {
282 memset(t, 0, sizeof(struct ext4_dir_entry_tail));
283 t->det_rec_len = ext4_rec_len_to_disk(
284 sizeof(struct ext4_dir_entry_tail), blocksize);
285 t->det_reserved_ft = EXT4_FT_DIR_CSUM;
286 }
287
288 /* Walk through a dirent block to find a checksum "dirent" at the tail */
289 static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode,
290 struct ext4_dir_entry *de)
291 {
292 struct ext4_dir_entry_tail *t;
293
294 #ifdef PARANOID
295 struct ext4_dir_entry *d, *top;
296
297 d = de;
298 top = (struct ext4_dir_entry *)(((void *)de) +
299 (EXT4_BLOCK_SIZE(inode->i_sb) -
300 sizeof(struct ext4_dir_entry_tail)));
301 while (d < top && d->rec_len)
302 d = (struct ext4_dir_entry *)(((void *)d) +
303 le16_to_cpu(d->rec_len));
304
305 if (d != top)
306 return NULL;
307
308 t = (struct ext4_dir_entry_tail *)d;
309 #else
310 t = EXT4_DIRENT_TAIL(de, EXT4_BLOCK_SIZE(inode->i_sb));
311 #endif
312
313 if (t->det_reserved_zero1 ||
314 le16_to_cpu(t->det_rec_len) != sizeof(struct ext4_dir_entry_tail) ||
315 t->det_reserved_zero2 ||
316 t->det_reserved_ft != EXT4_FT_DIR_CSUM)
317 return NULL;
318
319 return t;
320 }
321
322 static __le32 ext4_dirent_csum(struct inode *inode,
323 struct ext4_dir_entry *dirent, int size)
324 {
325 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
326 struct ext4_inode_info *ei = EXT4_I(inode);
327 __u32 csum;
328
329 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
330 return cpu_to_le32(csum);
331 }
332
333 #define warn_no_space_for_csum(inode) \
334 __warn_no_space_for_csum((inode), __func__, __LINE__)
335
336 static void __warn_no_space_for_csum(struct inode *inode, const char *func,
337 unsigned int line)
338 {
339 __ext4_warning_inode(inode, func, line,
340 "No space for directory leaf checksum. Please run e2fsck -D.");
341 }
342
343 int ext4_dirent_csum_verify(struct inode *inode, struct ext4_dir_entry *dirent)
344 {
345 struct ext4_dir_entry_tail *t;
346
347 if (!ext4_has_metadata_csum(inode->i_sb))
348 return 1;
349
350 t = get_dirent_tail(inode, dirent);
351 if (!t) {
352 warn_no_space_for_csum(inode);
353 return 0;
354 }
355
356 if (t->det_checksum != ext4_dirent_csum(inode, dirent,
357 (void *)t - (void *)dirent))
358 return 0;
359
360 return 1;
361 }
362
363 static void ext4_dirent_csum_set(struct inode *inode,
364 struct ext4_dir_entry *dirent)
365 {
366 struct ext4_dir_entry_tail *t;
367
368 if (!ext4_has_metadata_csum(inode->i_sb))
369 return;
370
371 t = get_dirent_tail(inode, dirent);
372 if (!t) {
373 warn_no_space_for_csum(inode);
374 return;
375 }
376
377 t->det_checksum = ext4_dirent_csum(inode, dirent,
378 (void *)t - (void *)dirent);
379 }
380
381 int ext4_handle_dirty_dirent_node(handle_t *handle,
382 struct inode *inode,
383 struct buffer_head *bh)
384 {
385 ext4_dirent_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
386 return ext4_handle_dirty_metadata(handle, inode, bh);
387 }
388
389 static struct dx_countlimit *get_dx_countlimit(struct inode *inode,
390 struct ext4_dir_entry *dirent,
391 int *offset)
392 {
393 struct ext4_dir_entry *dp;
394 struct dx_root_info *root;
395 int count_offset;
396
397 if (le16_to_cpu(dirent->rec_len) == EXT4_BLOCK_SIZE(inode->i_sb))
398 count_offset = 8;
399 else if (le16_to_cpu(dirent->rec_len) == 12) {
400 dp = (struct ext4_dir_entry *)(((void *)dirent) + 12);
401 if (le16_to_cpu(dp->rec_len) !=
402 EXT4_BLOCK_SIZE(inode->i_sb) - 12)
403 return NULL;
404 root = (struct dx_root_info *)(((void *)dp + 12));
405 if (root->reserved_zero ||
406 root->info_length != sizeof(struct dx_root_info))
407 return NULL;
408 count_offset = 32;
409 } else
410 return NULL;
411
412 if (offset)
413 *offset = count_offset;
414 return (struct dx_countlimit *)(((void *)dirent) + count_offset);
415 }
416
417 static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent,
418 int count_offset, int count, struct dx_tail *t)
419 {
420 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
421 struct ext4_inode_info *ei = EXT4_I(inode);
422 __u32 csum;
423 __le32 save_csum;
424 int size;
425
426 size = count_offset + (count * sizeof(struct dx_entry));
427 save_csum = t->dt_checksum;
428 t->dt_checksum = 0;
429 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
430 csum = ext4_chksum(sbi, csum, (__u8 *)t, sizeof(struct dx_tail));
431 t->dt_checksum = save_csum;
432
433 return cpu_to_le32(csum);
434 }
435
436 static int ext4_dx_csum_verify(struct inode *inode,
437 struct ext4_dir_entry *dirent)
438 {
439 struct dx_countlimit *c;
440 struct dx_tail *t;
441 int count_offset, limit, count;
442
443 if (!ext4_has_metadata_csum(inode->i_sb))
444 return 1;
445
446 c = get_dx_countlimit(inode, dirent, &count_offset);
447 if (!c) {
448 EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D.");
449 return 1;
450 }
451 limit = le16_to_cpu(c->limit);
452 count = le16_to_cpu(c->count);
453 if (count_offset + (limit * sizeof(struct dx_entry)) >
454 EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
455 warn_no_space_for_csum(inode);
456 return 1;
457 }
458 t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
459
460 if (t->dt_checksum != ext4_dx_csum(inode, dirent, count_offset,
461 count, t))
462 return 0;
463 return 1;
464 }
465
466 static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent)
467 {
468 struct dx_countlimit *c;
469 struct dx_tail *t;
470 int count_offset, limit, count;
471
472 if (!ext4_has_metadata_csum(inode->i_sb))
473 return;
474
475 c = get_dx_countlimit(inode, dirent, &count_offset);
476 if (!c) {
477 EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D.");
478 return;
479 }
480 limit = le16_to_cpu(c->limit);
481 count = le16_to_cpu(c->count);
482 if (count_offset + (limit * sizeof(struct dx_entry)) >
483 EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
484 warn_no_space_for_csum(inode);
485 return;
486 }
487 t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
488
489 t->dt_checksum = ext4_dx_csum(inode, dirent, count_offset, count, t);
490 }
491
492 static inline int ext4_handle_dirty_dx_node(handle_t *handle,
493 struct inode *inode,
494 struct buffer_head *bh)
495 {
496 ext4_dx_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
497 return ext4_handle_dirty_metadata(handle, inode, bh);
498 }
499
500 /*
501 * p is at least 6 bytes before the end of page
502 */
503 static inline struct ext4_dir_entry_2 *
504 ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
505 {
506 return (struct ext4_dir_entry_2 *)((char *)p +
507 ext4_rec_len_from_disk(p->rec_len, blocksize));
508 }
509
510 /*
511 * Future: use high four bits of block for coalesce-on-delete flags
512 * Mask them off for now.
513 */
514
515 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
516 {
517 return le32_to_cpu(entry->block) & 0x00ffffff;
518 }
519
520 static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
521 {
522 entry->block = cpu_to_le32(value);
523 }
524
525 static inline unsigned dx_get_hash(struct dx_entry *entry)
526 {
527 return le32_to_cpu(entry->hash);
528 }
529
530 static inline void dx_set_hash(struct dx_entry *entry, unsigned value)
531 {
532 entry->hash = cpu_to_le32(value);
533 }
534
535 static inline unsigned dx_get_count(struct dx_entry *entries)
536 {
537 return le16_to_cpu(((struct dx_countlimit *) entries)->count);
538 }
539
540 static inline unsigned dx_get_limit(struct dx_entry *entries)
541 {
542 return le16_to_cpu(((struct dx_countlimit *) entries)->limit);
543 }
544
545 static inline void dx_set_count(struct dx_entry *entries, unsigned value)
546 {
547 ((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
548 }
549
550 static inline void dx_set_limit(struct dx_entry *entries, unsigned value)
551 {
552 ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
553 }
554
555 static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
556 {
557 unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
558 EXT4_DIR_REC_LEN(2) - infosize;
559
560 if (ext4_has_metadata_csum(dir->i_sb))
561 entry_space -= sizeof(struct dx_tail);
562 return entry_space / sizeof(struct dx_entry);
563 }
564
565 static inline unsigned dx_node_limit(struct inode *dir)
566 {
567 unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);
568
569 if (ext4_has_metadata_csum(dir->i_sb))
570 entry_space -= sizeof(struct dx_tail);
571 return entry_space / sizeof(struct dx_entry);
572 }
573
574 /*
575 * Debug
576 */
577 #ifdef DX_DEBUG
578 static void dx_show_index(char * label, struct dx_entry *entries)
579 {
580 int i, n = dx_get_count (entries);
581 printk(KERN_DEBUG "%s index ", label);
582 for (i = 0; i < n; i++) {
583 printk("%x->%lu ", i ? dx_get_hash(entries + i) :
584 0, (unsigned long)dx_get_block(entries + i));
585 }
586 printk("\n");
587 }
588
589 struct stats
590 {
591 unsigned names;
592 unsigned space;
593 unsigned bcount;
594 };
595
596 static struct stats dx_show_leaf(struct inode *dir,
597 struct dx_hash_info *hinfo,
598 struct ext4_dir_entry_2 *de,
599 int size, int show_names)
600 {
601 unsigned names = 0, space = 0;
602 char *base = (char *) de;
603 struct dx_hash_info h = *hinfo;
604
605 printk("names: ");
606 while ((char *) de < base + size)
607 {
608 if (de->inode)
609 {
610 if (show_names)
611 {
612 #ifdef CONFIG_EXT4_FS_ENCRYPTION
613 int len;
614 char *name;
615 struct ext4_str fname_crypto_str
616 = {.name = NULL, .len = 0};
617 int res = 0;
618
619 name = de->name;
620 len = de->name_len;
621 if (ext4_encrypted_inode(inode))
622 res = ext4_get_encryption_info(dir);
623 if (res) {
624 printk(KERN_WARNING "Error setting up"
625 " fname crypto: %d\n", res);
626 }
627 if (ctx == NULL) {
628 /* Directory is not encrypted */
629 ext4fs_dirhash(de->name,
630 de->name_len, &h);
631 printk("%*.s:(U)%x.%u ", len,
632 name, h.hash,
633 (unsigned) ((char *) de
634 - base));
635 } else {
636 /* Directory is encrypted */
637 res = ext4_fname_crypto_alloc_buffer(
638 ctx, de->name_len,
639 &fname_crypto_str);
640 if (res < 0) {
641 printk(KERN_WARNING "Error "
642 "allocating crypto "
643 "buffer--skipping "
644 "crypto\n");
645 ctx = NULL;
646 }
647 res = ext4_fname_disk_to_usr(ctx, NULL, de,
648 &fname_crypto_str);
649 if (res < 0) {
650 printk(KERN_WARNING "Error "
651 "converting filename "
652 "from disk to usr"
653 "\n");
654 name = "??";
655 len = 2;
656 } else {
657 name = fname_crypto_str.name;
658 len = fname_crypto_str.len;
659 }
660 ext4fs_dirhash(de->name, de->name_len,
661 &h);
662 printk("%*.s:(E)%x.%u ", len, name,
663 h.hash, (unsigned) ((char *) de
664 - base));
665 ext4_fname_crypto_free_buffer(
666 &fname_crypto_str);
667 }
668 #else
669 int len = de->name_len;
670 char *name = de->name;
671 ext4fs_dirhash(de->name, de->name_len, &h);
672 printk("%*.s:%x.%u ", len, name, h.hash,
673 (unsigned) ((char *) de - base));
674 #endif
675 }
676 space += EXT4_DIR_REC_LEN(de->name_len);
677 names++;
678 }
679 de = ext4_next_entry(de, size);
680 }
681 printk("(%i)\n", names);
682 return (struct stats) { names, space, 1 };
683 }
684
685 struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
686 struct dx_entry *entries, int levels)
687 {
688 unsigned blocksize = dir->i_sb->s_blocksize;
689 unsigned count = dx_get_count(entries), names = 0, space = 0, i;
690 unsigned bcount = 0;
691 struct buffer_head *bh;
692 printk("%i indexed blocks...\n", count);
693 for (i = 0; i < count; i++, entries++)
694 {
695 ext4_lblk_t block = dx_get_block(entries);
696 ext4_lblk_t hash = i ? dx_get_hash(entries): 0;
697 u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
698 struct stats stats;
699 printk("%s%3u:%03u hash %8x/%8x ",levels?"":" ", i, block, hash, range);
700 bh = ext4_bread(NULL,dir, block, 0);
701 if (!bh || IS_ERR(bh))
702 continue;
703 stats = levels?
704 dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
705 dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *)
706 bh->b_data, blocksize, 0);
707 names += stats.names;
708 space += stats.space;
709 bcount += stats.bcount;
710 brelse(bh);
711 }
712 if (bcount)
713 printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n",
714 levels ? "" : " ", names, space/bcount,
715 (space/bcount)*100/blocksize);
716 return (struct stats) { names, space, bcount};
717 }
718 #endif /* DX_DEBUG */
719
720 /*
721 * Probe for a directory leaf block to search.
722 *
723 * dx_probe can return ERR_BAD_DX_DIR, which means there was a format
724 * error in the directory index, and the caller should fall back to
725 * searching the directory normally. The callers of dx_probe **MUST**
726 * check for this error code, and make sure it never gets reflected
727 * back to userspace.
728 */
729 static struct dx_frame *
730 dx_probe(struct ext4_filename *fname, struct inode *dir,
731 struct dx_hash_info *hinfo, struct dx_frame *frame_in)
732 {
733 unsigned count, indirect;
734 struct dx_entry *at, *entries, *p, *q, *m;
735 struct dx_root *root;
736 struct dx_frame *frame = frame_in;
737 struct dx_frame *ret_err = ERR_PTR(ERR_BAD_DX_DIR);
738 u32 hash;
739
740 frame->bh = ext4_read_dirblock(dir, 0, INDEX);
741 if (IS_ERR(frame->bh))
742 return (struct dx_frame *) frame->bh;
743
744 root = (struct dx_root *) frame->bh->b_data;
745 if (root->info.hash_version != DX_HASH_TEA &&
746 root->info.hash_version != DX_HASH_HALF_MD4 &&
747 root->info.hash_version != DX_HASH_LEGACY) {
748 ext4_warning_inode(dir, "Unrecognised inode hash code %u",
749 root->info.hash_version);
750 goto fail;
751 }
752 if (fname)
753 hinfo = &fname->hinfo;
754 hinfo->hash_version = root->info.hash_version;
755 if (hinfo->hash_version <= DX_HASH_TEA)
756 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
757 hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
758 if (fname && fname_name(fname))
759 ext4fs_dirhash(fname_name(fname), fname_len(fname), hinfo);
760 hash = hinfo->hash;
761
762 if (root->info.unused_flags & 1) {
763 ext4_warning_inode(dir, "Unimplemented hash flags: %#06x",
764 root->info.unused_flags);
765 goto fail;
766 }
767
768 indirect = root->info.indirect_levels;
769 if (indirect > 1) {
770 ext4_warning_inode(dir, "Unimplemented hash depth: %#06x",
771 root->info.indirect_levels);
772 goto fail;
773 }
774
775 entries = (struct dx_entry *)(((char *)&root->info) +
776 root->info.info_length);
777
778 if (dx_get_limit(entries) != dx_root_limit(dir,
779 root->info.info_length)) {
780 ext4_warning_inode(dir, "dx entry: limit %u != root limit %u",
781 dx_get_limit(entries),
782 dx_root_limit(dir, root->info.info_length));
783 goto fail;
784 }
785
786 dxtrace(printk("Look up %x", hash));
787 while (1) {
788 count = dx_get_count(entries);
789 if (!count || count > dx_get_limit(entries)) {
790 ext4_warning_inode(dir,
791 "dx entry: count %u beyond limit %u",
792 count, dx_get_limit(entries));
793 goto fail;
794 }
795
796 p = entries + 1;
797 q = entries + count - 1;
798 while (p <= q) {
799 m = p + (q - p) / 2;
800 dxtrace(printk("."));
801 if (dx_get_hash(m) > hash)
802 q = m - 1;
803 else
804 p = m + 1;
805 }
806
807 if (0) { // linear search cross check
808 unsigned n = count - 1;
809 at = entries;
810 while (n--)
811 {
812 dxtrace(printk(","));
813 if (dx_get_hash(++at) > hash)
814 {
815 at--;
816 break;
817 }
818 }
819 assert (at == p - 1);
820 }
821
822 at = p - 1;
823 dxtrace(printk(" %x->%u\n", at == entries ? 0 : dx_get_hash(at),
824 dx_get_block(at)));
825 frame->entries = entries;
826 frame->at = at;
827 if (!indirect--)
828 return frame;
829 frame++;
830 frame->bh = ext4_read_dirblock(dir, dx_get_block(at), INDEX);
831 if (IS_ERR(frame->bh)) {
832 ret_err = (struct dx_frame *) frame->bh;
833 frame->bh = NULL;
834 goto fail;
835 }
836 entries = ((struct dx_node *) frame->bh->b_data)->entries;
837
838 if (dx_get_limit(entries) != dx_node_limit(dir)) {
839 ext4_warning_inode(dir,
840 "dx entry: limit %u != node limit %u",
841 dx_get_limit(entries), dx_node_limit(dir));
842 goto fail;
843 }
844 }
845 fail:
846 while (frame >= frame_in) {
847 brelse(frame->bh);
848 frame--;
849 }
850
851 if (ret_err == ERR_PTR(ERR_BAD_DX_DIR))
852 ext4_warning_inode(dir,
853 "Corrupt directory, running e2fsck is recommended");
854 return ret_err;
855 }
856
857 static void dx_release(struct dx_frame *frames)
858 {
859 if (frames[0].bh == NULL)
860 return;
861
862 if (((struct dx_root *)frames[0].bh->b_data)->info.indirect_levels)
863 brelse(frames[1].bh);
864 brelse(frames[0].bh);
865 }
866
867 /*
868 * This function increments the frame pointer to search the next leaf
869 * block, and reads in the necessary intervening nodes if the search
870 * should be necessary. Whether or not the search is necessary is
871 * controlled by the hash parameter. If the hash value is even, then
872 * the search is only continued if the next block starts with that
873 * hash value. This is used if we are searching for a specific file.
874 *
875 * If the hash value is HASH_NB_ALWAYS, then always go to the next block.
876 *
877 * This function returns 1 if the caller should continue to search,
878 * or 0 if it should not. If there is an error reading one of the
879 * index blocks, it will a negative error code.
880 *
881 * If start_hash is non-null, it will be filled in with the starting
882 * hash of the next page.
883 */
884 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
885 struct dx_frame *frame,
886 struct dx_frame *frames,
887 __u32 *start_hash)
888 {
889 struct dx_frame *p;
890 struct buffer_head *bh;
891 int num_frames = 0;
892 __u32 bhash;
893
894 p = frame;
895 /*
896 * Find the next leaf page by incrementing the frame pointer.
897 * If we run out of entries in the interior node, loop around and
898 * increment pointer in the parent node. When we break out of
899 * this loop, num_frames indicates the number of interior
900 * nodes need to be read.
901 */
902 while (1) {
903 if (++(p->at) < p->entries + dx_get_count(p->entries))
904 break;
905 if (p == frames)
906 return 0;
907 num_frames++;
908 p--;
909 }
910
911 /*
912 * If the hash is 1, then continue only if the next page has a
913 * continuation hash of any value. This is used for readdir
914 * handling. Otherwise, check to see if the hash matches the
915 * desired contiuation hash. If it doesn't, return since
916 * there's no point to read in the successive index pages.
917 */
918 bhash = dx_get_hash(p->at);
919 if (start_hash)
920 *start_hash = bhash;
921 if ((hash & 1) == 0) {
922 if ((bhash & ~1) != hash)
923 return 0;
924 }
925 /*
926 * If the hash is HASH_NB_ALWAYS, we always go to the next
927 * block so no check is necessary
928 */
929 while (num_frames--) {
930 bh = ext4_read_dirblock(dir, dx_get_block(p->at), INDEX);
931 if (IS_ERR(bh))
932 return PTR_ERR(bh);
933 p++;
934 brelse(p->bh);
935 p->bh = bh;
936 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
937 }
938 return 1;
939 }
940
941
942 /*
943 * This function fills a red-black tree with information from a
944 * directory block. It returns the number directory entries loaded
945 * into the tree. If there is an error it is returned in err.
946 */
947 static int htree_dirblock_to_tree(struct file *dir_file,
948 struct inode *dir, ext4_lblk_t block,
949 struct dx_hash_info *hinfo,
950 __u32 start_hash, __u32 start_minor_hash)
951 {
952 struct buffer_head *bh;
953 struct ext4_dir_entry_2 *de, *top;
954 int err = 0, count = 0;
955 struct ext4_str fname_crypto_str = {.name = NULL, .len = 0}, tmp_str;
956
957 dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
958 (unsigned long)block));
959 bh = ext4_read_dirblock(dir, block, DIRENT);
960 if (IS_ERR(bh))
961 return PTR_ERR(bh);
962
963 de = (struct ext4_dir_entry_2 *) bh->b_data;
964 top = (struct ext4_dir_entry_2 *) ((char *) de +
965 dir->i_sb->s_blocksize -
966 EXT4_DIR_REC_LEN(0));
967 #ifdef CONFIG_EXT4_FS_ENCRYPTION
968 /* Check if the directory is encrypted */
969 if (ext4_encrypted_inode(dir)) {
970 err = ext4_get_encryption_info(dir);
971 if (err < 0) {
972 brelse(bh);
973 return err;
974 }
975 err = ext4_fname_crypto_alloc_buffer(dir, EXT4_NAME_LEN,
976 &fname_crypto_str);
977 if (err < 0) {
978 brelse(bh);
979 return err;
980 }
981 }
982 #endif
983 for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) {
984 if (ext4_check_dir_entry(dir, NULL, de, bh,
985 bh->b_data, bh->b_size,
986 (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
987 + ((char *)de - bh->b_data))) {
988 /* silently ignore the rest of the block */
989 break;
990 }
991 ext4fs_dirhash(de->name, de->name_len, hinfo);
992 if ((hinfo->hash < start_hash) ||
993 ((hinfo->hash == start_hash) &&
994 (hinfo->minor_hash < start_minor_hash)))
995 continue;
996 if (de->inode == 0)
997 continue;
998 if (!ext4_encrypted_inode(dir)) {
999 tmp_str.name = de->name;
1000 tmp_str.len = de->name_len;
1001 err = ext4_htree_store_dirent(dir_file,
1002 hinfo->hash, hinfo->minor_hash, de,
1003 &tmp_str);
1004 } else {
1005 int save_len = fname_crypto_str.len;
1006
1007 /* Directory is encrypted */
1008 err = ext4_fname_disk_to_usr(dir, hinfo, de,
1009 &fname_crypto_str);
1010 if (err < 0) {
1011 count = err;
1012 goto errout;
1013 }
1014 err = ext4_htree_store_dirent(dir_file,
1015 hinfo->hash, hinfo->minor_hash, de,
1016 &fname_crypto_str);
1017 fname_crypto_str.len = save_len;
1018 }
1019 if (err != 0) {
1020 count = err;
1021 goto errout;
1022 }
1023 count++;
1024 }
1025 errout:
1026 brelse(bh);
1027 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1028 ext4_fname_crypto_free_buffer(&fname_crypto_str);
1029 #endif
1030 return count;
1031 }
1032
1033
1034 /*
1035 * This function fills a red-black tree with information from a
1036 * directory. We start scanning the directory in hash order, starting
1037 * at start_hash and start_minor_hash.
1038 *
1039 * This function returns the number of entries inserted into the tree,
1040 * or a negative error code.
1041 */
1042 int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
1043 __u32 start_minor_hash, __u32 *next_hash)
1044 {
1045 struct dx_hash_info hinfo;
1046 struct ext4_dir_entry_2 *de;
1047 struct dx_frame frames[2], *frame;
1048 struct inode *dir;
1049 ext4_lblk_t block;
1050 int count = 0;
1051 int ret, err;
1052 __u32 hashval;
1053 struct ext4_str tmp_str;
1054
1055 dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
1056 start_hash, start_minor_hash));
1057 dir = file_inode(dir_file);
1058 if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) {
1059 hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
1060 if (hinfo.hash_version <= DX_HASH_TEA)
1061 hinfo.hash_version +=
1062 EXT4_SB(dir->i_sb)->s_hash_unsigned;
1063 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
1064 if (ext4_has_inline_data(dir)) {
1065 int has_inline_data = 1;
1066 count = htree_inlinedir_to_tree(dir_file, dir, 0,
1067 &hinfo, start_hash,
1068 start_minor_hash,
1069 &has_inline_data);
1070 if (has_inline_data) {
1071 *next_hash = ~0;
1072 return count;
1073 }
1074 }
1075 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
1076 start_hash, start_minor_hash);
1077 *next_hash = ~0;
1078 return count;
1079 }
1080 hinfo.hash = start_hash;
1081 hinfo.minor_hash = 0;
1082 frame = dx_probe(NULL, dir, &hinfo, frames);
1083 if (IS_ERR(frame))
1084 return PTR_ERR(frame);
1085
1086 /* Add '.' and '..' from the htree header */
1087 if (!start_hash && !start_minor_hash) {
1088 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
1089 tmp_str.name = de->name;
1090 tmp_str.len = de->name_len;
1091 err = ext4_htree_store_dirent(dir_file, 0, 0,
1092 de, &tmp_str);
1093 if (err != 0)
1094 goto errout;
1095 count++;
1096 }
1097 if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
1098 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
1099 de = ext4_next_entry(de, dir->i_sb->s_blocksize);
1100 tmp_str.name = de->name;
1101 tmp_str.len = de->name_len;
1102 err = ext4_htree_store_dirent(dir_file, 2, 0,
1103 de, &tmp_str);
1104 if (err != 0)
1105 goto errout;
1106 count++;
1107 }
1108
1109 while (1) {
1110 block = dx_get_block(frame->at);
1111 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
1112 start_hash, start_minor_hash);
1113 if (ret < 0) {
1114 err = ret;
1115 goto errout;
1116 }
1117 count += ret;
1118 hashval = ~0;
1119 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
1120 frame, frames, &hashval);
1121 *next_hash = hashval;
1122 if (ret < 0) {
1123 err = ret;
1124 goto errout;
1125 }
1126 /*
1127 * Stop if: (a) there are no more entries, or
1128 * (b) we have inserted at least one entry and the
1129 * next hash value is not a continuation
1130 */
1131 if ((ret == 0) ||
1132 (count && ((hashval & 1) == 0)))
1133 break;
1134 }
1135 dx_release(frames);
1136 dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, "
1137 "next hash: %x\n", count, *next_hash));
1138 return count;
1139 errout:
1140 dx_release(frames);
1141 return (err);
1142 }
1143
1144 static inline int search_dirblock(struct buffer_head *bh,
1145 struct inode *dir,
1146 struct ext4_filename *fname,
1147 const struct qstr *d_name,
1148 unsigned int offset,
1149 struct ext4_dir_entry_2 **res_dir)
1150 {
1151 return ext4_search_dir(bh, bh->b_data, dir->i_sb->s_blocksize, dir,
1152 fname, d_name, offset, res_dir);
1153 }
1154
1155 /*
1156 * Directory block splitting, compacting
1157 */
1158
1159 /*
1160 * Create map of hash values, offsets, and sizes, stored at end of block.
1161 * Returns number of entries mapped.
1162 */
1163 static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de,
1164 unsigned blocksize, struct dx_hash_info *hinfo,
1165 struct dx_map_entry *map_tail)
1166 {
1167 int count = 0;
1168 char *base = (char *) de;
1169 struct dx_hash_info h = *hinfo;
1170
1171 while ((char *) de < base + blocksize) {
1172 if (de->name_len && de->inode) {
1173 ext4fs_dirhash(de->name, de->name_len, &h);
1174 map_tail--;
1175 map_tail->hash = h.hash;
1176 map_tail->offs = ((char *) de - base)>>2;
1177 map_tail->size = le16_to_cpu(de->rec_len);
1178 count++;
1179 cond_resched();
1180 }
1181 /* XXX: do we need to check rec_len == 0 case? -Chris */
1182 de = ext4_next_entry(de, blocksize);
1183 }
1184 return count;
1185 }
1186
1187 /* Sort map by hash value */
1188 static void dx_sort_map (struct dx_map_entry *map, unsigned count)
1189 {
1190 struct dx_map_entry *p, *q, *top = map + count - 1;
1191 int more;
1192 /* Combsort until bubble sort doesn't suck */
1193 while (count > 2) {
1194 count = count*10/13;
1195 if (count - 9 < 2) /* 9, 10 -> 11 */
1196 count = 11;
1197 for (p = top, q = p - count; q >= map; p--, q--)
1198 if (p->hash < q->hash)
1199 swap(*p, *q);
1200 }
1201 /* Garden variety bubble sort */
1202 do {
1203 more = 0;
1204 q = top;
1205 while (q-- > map) {
1206 if (q[1].hash >= q[0].hash)
1207 continue;
1208 swap(*(q+1), *q);
1209 more = 1;
1210 }
1211 } while(more);
1212 }
1213
1214 static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
1215 {
1216 struct dx_entry *entries = frame->entries;
1217 struct dx_entry *old = frame->at, *new = old + 1;
1218 int count = dx_get_count(entries);
1219
1220 assert(count < dx_get_limit(entries));
1221 assert(old < entries + count);
1222 memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
1223 dx_set_hash(new, hash);
1224 dx_set_block(new, block);
1225 dx_set_count(entries, count + 1);
1226 }
1227
1228 /*
1229 * NOTE! unlike strncmp, ext4_match returns 1 for success, 0 for failure.
1230 *
1231 * `len <= EXT4_NAME_LEN' is guaranteed by caller.
1232 * `de != NULL' is guaranteed by caller.
1233 */
1234 static inline int ext4_match(struct ext4_filename *fname,
1235 struct ext4_dir_entry_2 *de)
1236 {
1237 const void *name = fname_name(fname);
1238 u32 len = fname_len(fname);
1239
1240 if (!de->inode)
1241 return 0;
1242
1243 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1244 if (unlikely(!name)) {
1245 if (fname->usr_fname->name[0] == '_') {
1246 int ret;
1247 if (de->name_len < 16)
1248 return 0;
1249 ret = memcmp(de->name + de->name_len - 16,
1250 fname->crypto_buf.name + 8, 16);
1251 return (ret == 0) ? 1 : 0;
1252 }
1253 name = fname->crypto_buf.name;
1254 len = fname->crypto_buf.len;
1255 }
1256 #endif
1257 if (de->name_len != len)
1258 return 0;
1259 return (memcmp(de->name, name, len) == 0) ? 1 : 0;
1260 }
1261
1262 /*
1263 * Returns 0 if not found, -1 on failure, and 1 on success
1264 */
1265 int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size,
1266 struct inode *dir, struct ext4_filename *fname,
1267 const struct qstr *d_name,
1268 unsigned int offset, struct ext4_dir_entry_2 **res_dir)
1269 {
1270 struct ext4_dir_entry_2 * de;
1271 char * dlimit;
1272 int de_len;
1273 int res;
1274
1275 de = (struct ext4_dir_entry_2 *)search_buf;
1276 dlimit = search_buf + buf_size;
1277 while ((char *) de < dlimit) {
1278 /* this code is executed quadratically often */
1279 /* do minimal checking `by hand' */
1280 if ((char *) de + de->name_len <= dlimit) {
1281 res = ext4_match(fname, de);
1282 if (res < 0) {
1283 res = -1;
1284 goto return_result;
1285 }
1286 if (res > 0) {
1287 /* found a match - just to be sure, do
1288 * a full check */
1289 if (ext4_check_dir_entry(dir, NULL, de, bh,
1290 bh->b_data,
1291 bh->b_size, offset)) {
1292 res = -1;
1293 goto return_result;
1294 }
1295 *res_dir = de;
1296 res = 1;
1297 goto return_result;
1298 }
1299
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 res = -1;
1306 goto return_result;
1307 }
1308 offset += de_len;
1309 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
1310 }
1311
1312 res = 0;
1313 return_result:
1314 return res;
1315 }
1316
1317 static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block,
1318 struct ext4_dir_entry *de)
1319 {
1320 struct super_block *sb = dir->i_sb;
1321
1322 if (!is_dx(dir))
1323 return 0;
1324 if (block == 0)
1325 return 1;
1326 if (de->inode == 0 &&
1327 ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) ==
1328 sb->s_blocksize)
1329 return 1;
1330 return 0;
1331 }
1332
1333 /*
1334 * ext4_find_entry()
1335 *
1336 * finds an entry in the specified directory with the wanted name. It
1337 * returns the cache buffer in which the entry was found, and the entry
1338 * itself (as a parameter - res_dir). It does NOT read the inode of the
1339 * entry - you'll have to do that yourself if you want to.
1340 *
1341 * The returned buffer_head has ->b_count elevated. The caller is expected
1342 * to brelse() it when appropriate.
1343 */
1344 static struct buffer_head * ext4_find_entry (struct inode *dir,
1345 const struct qstr *d_name,
1346 struct ext4_dir_entry_2 **res_dir,
1347 int *inlined)
1348 {
1349 struct super_block *sb;
1350 struct buffer_head *bh_use[NAMEI_RA_SIZE];
1351 struct buffer_head *bh, *ret = NULL;
1352 ext4_lblk_t start, block, b;
1353 const u8 *name = d_name->name;
1354 int ra_max = 0; /* Number of bh's in the readahead
1355 buffer, bh_use[] */
1356 int ra_ptr = 0; /* Current index into readahead
1357 buffer */
1358 int num = 0;
1359 ext4_lblk_t nblocks;
1360 int i, namelen, retval;
1361 struct ext4_filename fname;
1362
1363 *res_dir = NULL;
1364 sb = dir->i_sb;
1365 namelen = d_name->len;
1366 if (namelen > EXT4_NAME_LEN)
1367 return NULL;
1368
1369 retval = ext4_fname_setup_filename(dir, d_name, 1, &fname);
1370 if (retval)
1371 return ERR_PTR(retval);
1372
1373 if (ext4_has_inline_data(dir)) {
1374 int has_inline_data = 1;
1375 ret = ext4_find_inline_entry(dir, &fname, d_name, res_dir,
1376 &has_inline_data);
1377 if (has_inline_data) {
1378 if (inlined)
1379 *inlined = 1;
1380 goto cleanup_and_exit;
1381 }
1382 }
1383
1384 if ((namelen <= 2) && (name[0] == '.') &&
1385 (name[1] == '.' || name[1] == '\0')) {
1386 /*
1387 * "." or ".." will only be in the first block
1388 * NFS may look up ".."; "." should be handled by the VFS
1389 */
1390 block = start = 0;
1391 nblocks = 1;
1392 goto restart;
1393 }
1394 if (is_dx(dir)) {
1395 ret = ext4_dx_find_entry(dir, &fname, res_dir);
1396 /*
1397 * On success, or if the error was file not found,
1398 * return. Otherwise, fall back to doing a search the
1399 * old fashioned way.
1400 */
1401 if (!IS_ERR(ret) || PTR_ERR(ret) != ERR_BAD_DX_DIR)
1402 goto cleanup_and_exit;
1403 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
1404 "falling back\n"));
1405 }
1406 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1407 start = EXT4_I(dir)->i_dir_start_lookup;
1408 if (start >= nblocks)
1409 start = 0;
1410 block = start;
1411 restart:
1412 do {
1413 /*
1414 * We deal with the read-ahead logic here.
1415 */
1416 if (ra_ptr >= ra_max) {
1417 /* Refill the readahead buffer */
1418 ra_ptr = 0;
1419 b = block;
1420 for (ra_max = 0; ra_max < NAMEI_RA_SIZE; ra_max++) {
1421 /*
1422 * Terminate if we reach the end of the
1423 * directory and must wrap, or if our
1424 * search has finished at this block.
1425 */
1426 if (b >= nblocks || (num && block == start)) {
1427 bh_use[ra_max] = NULL;
1428 break;
1429 }
1430 num++;
1431 bh = ext4_getblk(NULL, dir, b++, 0);
1432 if (IS_ERR(bh)) {
1433 if (ra_max == 0) {
1434 ret = bh;
1435 goto cleanup_and_exit;
1436 }
1437 break;
1438 }
1439 bh_use[ra_max] = bh;
1440 if (bh)
1441 ll_rw_block(READ | REQ_META | REQ_PRIO,
1442 1, &bh);
1443 }
1444 }
1445 if ((bh = bh_use[ra_ptr++]) == NULL)
1446 goto next;
1447 wait_on_buffer(bh);
1448 if (!buffer_uptodate(bh)) {
1449 /* read error, skip block & hope for the best */
1450 EXT4_ERROR_INODE(dir, "reading directory lblock %lu",
1451 (unsigned long) block);
1452 brelse(bh);
1453 goto next;
1454 }
1455 if (!buffer_verified(bh) &&
1456 !is_dx_internal_node(dir, block,
1457 (struct ext4_dir_entry *)bh->b_data) &&
1458 !ext4_dirent_csum_verify(dir,
1459 (struct ext4_dir_entry *)bh->b_data)) {
1460 EXT4_ERROR_INODE(dir, "checksumming directory "
1461 "block %lu", (unsigned long)block);
1462 brelse(bh);
1463 goto next;
1464 }
1465 set_buffer_verified(bh);
1466 i = search_dirblock(bh, dir, &fname, d_name,
1467 block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
1468 if (i == 1) {
1469 EXT4_I(dir)->i_dir_start_lookup = block;
1470 ret = bh;
1471 goto cleanup_and_exit;
1472 } else {
1473 brelse(bh);
1474 if (i < 0)
1475 goto cleanup_and_exit;
1476 }
1477 next:
1478 if (++block >= nblocks)
1479 block = 0;
1480 } while (block != start);
1481
1482 /*
1483 * If the directory has grown while we were searching, then
1484 * search the last part of the directory before giving up.
1485 */
1486 block = nblocks;
1487 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1488 if (block < nblocks) {
1489 start = 0;
1490 goto restart;
1491 }
1492
1493 cleanup_and_exit:
1494 /* Clean up the read-ahead blocks */
1495 for (; ra_ptr < ra_max; ra_ptr++)
1496 brelse(bh_use[ra_ptr]);
1497 ext4_fname_free_filename(&fname);
1498 return ret;
1499 }
1500
1501 static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
1502 struct ext4_filename *fname,
1503 struct ext4_dir_entry_2 **res_dir)
1504 {
1505 struct super_block * sb = dir->i_sb;
1506 struct dx_frame frames[2], *frame;
1507 const struct qstr *d_name = fname->usr_fname;
1508 struct buffer_head *bh;
1509 ext4_lblk_t block;
1510 int retval;
1511
1512 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1513 *res_dir = NULL;
1514 #endif
1515 frame = dx_probe(fname, dir, NULL, frames);
1516 if (IS_ERR(frame))
1517 return (struct buffer_head *) frame;
1518 do {
1519 block = dx_get_block(frame->at);
1520 bh = ext4_read_dirblock(dir, block, DIRENT);
1521 if (IS_ERR(bh))
1522 goto errout;
1523
1524 retval = search_dirblock(bh, dir, fname, d_name,
1525 block << EXT4_BLOCK_SIZE_BITS(sb),
1526 res_dir);
1527 if (retval == 1)
1528 goto success;
1529 brelse(bh);
1530 if (retval == -1) {
1531 bh = ERR_PTR(ERR_BAD_DX_DIR);
1532 goto errout;
1533 }
1534
1535 /* Check to see if we should continue to search */
1536 retval = ext4_htree_next_block(dir, fname->hinfo.hash, frame,
1537 frames, NULL);
1538 if (retval < 0) {
1539 ext4_warning_inode(dir,
1540 "error %d reading directory index block",
1541 retval);
1542 bh = ERR_PTR(retval);
1543 goto errout;
1544 }
1545 } while (retval == 1);
1546
1547 bh = NULL;
1548 errout:
1549 dxtrace(printk(KERN_DEBUG "%s not found\n", d_name->name));
1550 success:
1551 dx_release(frames);
1552 return bh;
1553 }
1554
1555 static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
1556 {
1557 struct inode *inode;
1558 struct ext4_dir_entry_2 *de;
1559 struct buffer_head *bh;
1560
1561 if (ext4_encrypted_inode(dir)) {
1562 int res = ext4_get_encryption_info(dir);
1563
1564 /*
1565 * This should be a properly defined flag for
1566 * dentry->d_flags when we uplift this to the VFS.
1567 * d_fsdata is set to (void *) 1 if if the dentry is
1568 * created while the directory was encrypted and we
1569 * don't have access to the key.
1570 */
1571 dentry->d_fsdata = NULL;
1572 if (ext4_encryption_info(dir))
1573 dentry->d_fsdata = (void *) 1;
1574 d_set_d_op(dentry, &ext4_encrypted_d_ops);
1575 if (res && res != -ENOKEY)
1576 return ERR_PTR(res);
1577 }
1578
1579 if (dentry->d_name.len > EXT4_NAME_LEN)
1580 return ERR_PTR(-ENAMETOOLONG);
1581
1582 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
1583 if (IS_ERR(bh))
1584 return (struct dentry *) bh;
1585 inode = NULL;
1586 if (bh) {
1587 __u32 ino = le32_to_cpu(de->inode);
1588 brelse(bh);
1589 if (!ext4_valid_inum(dir->i_sb, ino)) {
1590 EXT4_ERROR_INODE(dir, "bad inode number: %u", ino);
1591 return ERR_PTR(-EFSCORRUPTED);
1592 }
1593 if (unlikely(ino == dir->i_ino)) {
1594 EXT4_ERROR_INODE(dir, "'%pd' linked to parent dir",
1595 dentry);
1596 return ERR_PTR(-EFSCORRUPTED);
1597 }
1598 inode = ext4_iget_normal(dir->i_sb, ino);
1599 if (inode == ERR_PTR(-ESTALE)) {
1600 EXT4_ERROR_INODE(dir,
1601 "deleted inode referenced: %u",
1602 ino);
1603 return ERR_PTR(-EFSCORRUPTED);
1604 }
1605 if (!IS_ERR(inode) && ext4_encrypted_inode(dir) &&
1606 (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) &&
1607 !ext4_is_child_context_consistent_with_parent(dir,
1608 inode)) {
1609 int nokey = ext4_encrypted_inode(inode) &&
1610 !ext4_encryption_info(inode);
1611
1612 iput(inode);
1613 if (nokey)
1614 return ERR_PTR(-ENOKEY);
1615 ext4_warning(inode->i_sb,
1616 "Inconsistent encryption contexts: %lu/%lu\n",
1617 (unsigned long) dir->i_ino,
1618 (unsigned long) inode->i_ino);
1619 return ERR_PTR(-EPERM);
1620 }
1621 }
1622 return d_splice_alias(inode, dentry);
1623 }
1624
1625
1626 struct dentry *ext4_get_parent(struct dentry *child)
1627 {
1628 __u32 ino;
1629 static const struct qstr dotdot = QSTR_INIT("..", 2);
1630 struct ext4_dir_entry_2 * de;
1631 struct buffer_head *bh;
1632
1633 bh = ext4_find_entry(d_inode(child), &dotdot, &de, NULL);
1634 if (IS_ERR(bh))
1635 return (struct dentry *) bh;
1636 if (!bh)
1637 return ERR_PTR(-ENOENT);
1638 ino = le32_to_cpu(de->inode);
1639 brelse(bh);
1640
1641 if (!ext4_valid_inum(d_inode(child)->i_sb, ino)) {
1642 EXT4_ERROR_INODE(d_inode(child),
1643 "bad parent inode number: %u", ino);
1644 return ERR_PTR(-EFSCORRUPTED);
1645 }
1646
1647 return d_obtain_alias(ext4_iget_normal(d_inode(child)->i_sb, ino));
1648 }
1649
1650 /*
1651 * Move count entries from end of map between two memory locations.
1652 * Returns pointer to last entry moved.
1653 */
1654 static struct ext4_dir_entry_2 *
1655 dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count,
1656 unsigned blocksize)
1657 {
1658 unsigned rec_len = 0;
1659
1660 while (count--) {
1661 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
1662 (from + (map->offs<<2));
1663 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1664 memcpy (to, de, rec_len);
1665 ((struct ext4_dir_entry_2 *) to)->rec_len =
1666 ext4_rec_len_to_disk(rec_len, blocksize);
1667 de->inode = 0;
1668 map++;
1669 to += rec_len;
1670 }
1671 return (struct ext4_dir_entry_2 *) (to - rec_len);
1672 }
1673
1674 /*
1675 * Compact each dir entry in the range to the minimal rec_len.
1676 * Returns pointer to last entry in range.
1677 */
1678 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize)
1679 {
1680 struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
1681 unsigned rec_len = 0;
1682
1683 prev = to = de;
1684 while ((char*)de < base + blocksize) {
1685 next = ext4_next_entry(de, blocksize);
1686 if (de->inode && de->name_len) {
1687 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1688 if (de > to)
1689 memmove(to, de, rec_len);
1690 to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
1691 prev = to;
1692 to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
1693 }
1694 de = next;
1695 }
1696 return prev;
1697 }
1698
1699 /*
1700 * Split a full leaf block to make room for a new dir entry.
1701 * Allocate a new block, and move entries so that they are approx. equally full.
1702 * Returns pointer to de in block into which the new entry will be inserted.
1703 */
1704 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
1705 struct buffer_head **bh,struct dx_frame *frame,
1706 struct dx_hash_info *hinfo)
1707 {
1708 unsigned blocksize = dir->i_sb->s_blocksize;
1709 unsigned count, continued;
1710 struct buffer_head *bh2;
1711 ext4_lblk_t newblock;
1712 u32 hash2;
1713 struct dx_map_entry *map;
1714 char *data1 = (*bh)->b_data, *data2;
1715 unsigned split, move, size;
1716 struct ext4_dir_entry_2 *de = NULL, *de2;
1717 struct ext4_dir_entry_tail *t;
1718 int csum_size = 0;
1719 int err = 0, i;
1720
1721 if (ext4_has_metadata_csum(dir->i_sb))
1722 csum_size = sizeof(struct ext4_dir_entry_tail);
1723
1724 bh2 = ext4_append(handle, dir, &newblock);
1725 if (IS_ERR(bh2)) {
1726 brelse(*bh);
1727 *bh = NULL;
1728 return (struct ext4_dir_entry_2 *) bh2;
1729 }
1730
1731 BUFFER_TRACE(*bh, "get_write_access");
1732 err = ext4_journal_get_write_access(handle, *bh);
1733 if (err)
1734 goto journal_error;
1735
1736 BUFFER_TRACE(frame->bh, "get_write_access");
1737 err = ext4_journal_get_write_access(handle, frame->bh);
1738 if (err)
1739 goto journal_error;
1740
1741 data2 = bh2->b_data;
1742
1743 /* create map in the end of data2 block */
1744 map = (struct dx_map_entry *) (data2 + blocksize);
1745 count = dx_make_map(dir, (struct ext4_dir_entry_2 *) data1,
1746 blocksize, hinfo, map);
1747 map -= count;
1748 dx_sort_map(map, count);
1749 /* Split the existing block in the middle, size-wise */
1750 size = 0;
1751 move = 0;
1752 for (i = count-1; i >= 0; i--) {
1753 /* is more than half of this entry in 2nd half of the block? */
1754 if (size + map[i].size/2 > blocksize/2)
1755 break;
1756 size += map[i].size;
1757 move++;
1758 }
1759 /* map index at which we will split */
1760 split = count - move;
1761 hash2 = map[split].hash;
1762 continued = hash2 == map[split - 1].hash;
1763 dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
1764 (unsigned long)dx_get_block(frame->at),
1765 hash2, split, count-split));
1766
1767 /* Fancy dance to stay within two buffers */
1768 de2 = dx_move_dirents(data1, data2, map + split, count - split,
1769 blocksize);
1770 de = dx_pack_dirents(data1, blocksize);
1771 de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
1772 (char *) de,
1773 blocksize);
1774 de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
1775 (char *) de2,
1776 blocksize);
1777 if (csum_size) {
1778 t = EXT4_DIRENT_TAIL(data2, blocksize);
1779 initialize_dirent_tail(t, blocksize);
1780
1781 t = EXT4_DIRENT_TAIL(data1, blocksize);
1782 initialize_dirent_tail(t, blocksize);
1783 }
1784
1785 dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data1,
1786 blocksize, 1));
1787 dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data2,
1788 blocksize, 1));
1789
1790 /* Which block gets the new entry? */
1791 if (hinfo->hash >= hash2) {
1792 swap(*bh, bh2);
1793 de = de2;
1794 }
1795 dx_insert_block(frame, hash2 + continued, newblock);
1796 err = ext4_handle_dirty_dirent_node(handle, dir, bh2);
1797 if (err)
1798 goto journal_error;
1799 err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
1800 if (err)
1801 goto journal_error;
1802 brelse(bh2);
1803 dxtrace(dx_show_index("frame", frame->entries));
1804 return de;
1805
1806 journal_error:
1807 brelse(*bh);
1808 brelse(bh2);
1809 *bh = NULL;
1810 ext4_std_error(dir->i_sb, err);
1811 return ERR_PTR(err);
1812 }
1813
1814 int ext4_find_dest_de(struct inode *dir, struct inode *inode,
1815 struct buffer_head *bh,
1816 void *buf, int buf_size,
1817 struct ext4_filename *fname,
1818 struct ext4_dir_entry_2 **dest_de)
1819 {
1820 struct ext4_dir_entry_2 *de;
1821 unsigned short reclen = EXT4_DIR_REC_LEN(fname_len(fname));
1822 int nlen, rlen;
1823 unsigned int offset = 0;
1824 char *top;
1825 int res;
1826
1827 de = (struct ext4_dir_entry_2 *)buf;
1828 top = buf + buf_size - reclen;
1829 while ((char *) de <= top) {
1830 if (ext4_check_dir_entry(dir, NULL, de, bh,
1831 buf, buf_size, offset)) {
1832 res = -EFSCORRUPTED;
1833 goto return_result;
1834 }
1835 /* Provide crypto context and crypto buffer to ext4 match */
1836 res = ext4_match(fname, de);
1837 if (res < 0)
1838 goto return_result;
1839 if (res > 0) {
1840 res = -EEXIST;
1841 goto return_result;
1842 }
1843 nlen = EXT4_DIR_REC_LEN(de->name_len);
1844 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
1845 if ((de->inode ? rlen - nlen : rlen) >= reclen)
1846 break;
1847 de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
1848 offset += rlen;
1849 }
1850
1851 if ((char *) de > top)
1852 res = -ENOSPC;
1853 else {
1854 *dest_de = de;
1855 res = 0;
1856 }
1857 return_result:
1858 return res;
1859 }
1860
1861 int ext4_insert_dentry(struct inode *dir,
1862 struct inode *inode,
1863 struct ext4_dir_entry_2 *de,
1864 int buf_size,
1865 struct ext4_filename *fname)
1866 {
1867
1868 int nlen, rlen;
1869
1870 nlen = EXT4_DIR_REC_LEN(de->name_len);
1871 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
1872 if (de->inode) {
1873 struct ext4_dir_entry_2 *de1 =
1874 (struct ext4_dir_entry_2 *)((char *)de + nlen);
1875 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, buf_size);
1876 de->rec_len = ext4_rec_len_to_disk(nlen, buf_size);
1877 de = de1;
1878 }
1879 de->file_type = EXT4_FT_UNKNOWN;
1880 de->inode = cpu_to_le32(inode->i_ino);
1881 ext4_set_de_type(inode->i_sb, de, inode->i_mode);
1882 de->name_len = fname_len(fname);
1883 memcpy(de->name, fname_name(fname), fname_len(fname));
1884 return 0;
1885 }
1886
1887 /*
1888 * Add a new entry into a directory (leaf) block. If de is non-NULL,
1889 * it points to a directory entry which is guaranteed to be large
1890 * enough for new directory entry. If de is NULL, then
1891 * add_dirent_to_buf will attempt search the directory block for
1892 * space. It will return -ENOSPC if no space is available, and -EIO
1893 * and -EEXIST if directory entry already exists.
1894 */
1895 static int add_dirent_to_buf(handle_t *handle, struct ext4_filename *fname,
1896 struct inode *dir,
1897 struct inode *inode, struct ext4_dir_entry_2 *de,
1898 struct buffer_head *bh)
1899 {
1900 unsigned int blocksize = dir->i_sb->s_blocksize;
1901 int csum_size = 0;
1902 int err;
1903
1904 if (ext4_has_metadata_csum(inode->i_sb))
1905 csum_size = sizeof(struct ext4_dir_entry_tail);
1906
1907 if (!de) {
1908 err = ext4_find_dest_de(dir, inode, bh, bh->b_data,
1909 blocksize - csum_size, fname, &de);
1910 if (err)
1911 return err;
1912 }
1913 BUFFER_TRACE(bh, "get_write_access");
1914 err = ext4_journal_get_write_access(handle, bh);
1915 if (err) {
1916 ext4_std_error(dir->i_sb, err);
1917 return err;
1918 }
1919
1920 /* By now the buffer is marked for journaling. Due to crypto operations,
1921 * the following function call may fail */
1922 err = ext4_insert_dentry(dir, inode, de, blocksize, fname);
1923 if (err < 0)
1924 return err;
1925
1926 /*
1927 * XXX shouldn't update any times until successful
1928 * completion of syscall, but too many callers depend
1929 * on this.
1930 *
1931 * XXX similarly, too many callers depend on
1932 * ext4_new_inode() setting the times, but error
1933 * recovery deletes the inode, so the worst that can
1934 * happen is that the times are slightly out of date
1935 * and/or different from the directory change time.
1936 */
1937 dir->i_mtime = dir->i_ctime = ext4_current_time(dir);
1938 ext4_update_dx_flag(dir);
1939 dir->i_version++;
1940 ext4_mark_inode_dirty(handle, dir);
1941 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1942 err = ext4_handle_dirty_dirent_node(handle, dir, bh);
1943 if (err)
1944 ext4_std_error(dir->i_sb, err);
1945 return 0;
1946 }
1947
1948 /*
1949 * This converts a one block unindexed directory to a 3 block indexed
1950 * directory, and adds the dentry to the indexed directory.
1951 */
1952 static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname,
1953 struct inode *dir,
1954 struct inode *inode, struct buffer_head *bh)
1955 {
1956 struct buffer_head *bh2;
1957 struct dx_root *root;
1958 struct dx_frame frames[2], *frame;
1959 struct dx_entry *entries;
1960 struct ext4_dir_entry_2 *de, *de2;
1961 struct ext4_dir_entry_tail *t;
1962 char *data1, *top;
1963 unsigned len;
1964 int retval;
1965 unsigned blocksize;
1966 ext4_lblk_t block;
1967 struct fake_dirent *fde;
1968 int csum_size = 0;
1969
1970 if (ext4_has_metadata_csum(inode->i_sb))
1971 csum_size = sizeof(struct ext4_dir_entry_tail);
1972
1973 blocksize = dir->i_sb->s_blocksize;
1974 dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
1975 BUFFER_TRACE(bh, "get_write_access");
1976 retval = ext4_journal_get_write_access(handle, bh);
1977 if (retval) {
1978 ext4_std_error(dir->i_sb, retval);
1979 brelse(bh);
1980 return retval;
1981 }
1982 root = (struct dx_root *) bh->b_data;
1983
1984 /* The 0th block becomes the root, move the dirents out */
1985 fde = &root->dotdot;
1986 de = (struct ext4_dir_entry_2 *)((char *)fde +
1987 ext4_rec_len_from_disk(fde->rec_len, blocksize));
1988 if ((char *) de >= (((char *) root) + blocksize)) {
1989 EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
1990 brelse(bh);
1991 return -EFSCORRUPTED;
1992 }
1993 len = ((char *) root) + (blocksize - csum_size) - (char *) de;
1994
1995 /* Allocate new block for the 0th block's dirents */
1996 bh2 = ext4_append(handle, dir, &block);
1997 if (IS_ERR(bh2)) {
1998 brelse(bh);
1999 return PTR_ERR(bh2);
2000 }
2001 ext4_set_inode_flag(dir, EXT4_INODE_INDEX);
2002 data1 = bh2->b_data;
2003
2004 memcpy (data1, de, len);
2005 de = (struct ext4_dir_entry_2 *) data1;
2006 top = data1 + len;
2007 while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
2008 de = de2;
2009 de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
2010 (char *) de,
2011 blocksize);
2012
2013 if (csum_size) {
2014 t = EXT4_DIRENT_TAIL(data1, blocksize);
2015 initialize_dirent_tail(t, blocksize);
2016 }
2017
2018 /* Initialize the root; the dot dirents already exist */
2019 de = (struct ext4_dir_entry_2 *) (&root->dotdot);
2020 de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
2021 blocksize);
2022 memset (&root->info, 0, sizeof(root->info));
2023 root->info.info_length = sizeof(root->info);
2024 root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
2025 entries = root->entries;
2026 dx_set_block(entries, 1);
2027 dx_set_count(entries, 1);
2028 dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
2029
2030 /* Initialize as for dx_probe */
2031 fname->hinfo.hash_version = root->info.hash_version;
2032 if (fname->hinfo.hash_version <= DX_HASH_TEA)
2033 fname->hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
2034 fname->hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
2035 ext4fs_dirhash(fname_name(fname), fname_len(fname), &fname->hinfo);
2036
2037 memset(frames, 0, sizeof(frames));
2038 frame = frames;
2039 frame->entries = entries;
2040 frame->at = entries;
2041 frame->bh = bh;
2042 bh = bh2;
2043
2044 retval = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
2045 if (retval)
2046 goto out_frames;
2047 retval = ext4_handle_dirty_dirent_node(handle, dir, bh);
2048 if (retval)
2049 goto out_frames;
2050
2051 de = do_split(handle,dir, &bh, frame, &fname->hinfo);
2052 if (IS_ERR(de)) {
2053 retval = PTR_ERR(de);
2054 goto out_frames;
2055 }
2056 dx_release(frames);
2057
2058 retval = add_dirent_to_buf(handle, fname, dir, inode, de, bh);
2059 brelse(bh);
2060 return retval;
2061 out_frames:
2062 /*
2063 * Even if the block split failed, we have to properly write
2064 * out all the changes we did so far. Otherwise we can end up
2065 * with corrupted filesystem.
2066 */
2067 ext4_mark_inode_dirty(handle, dir);
2068 dx_release(frames);
2069 return retval;
2070 }
2071
2072 /*
2073 * ext4_add_entry()
2074 *
2075 * adds a file entry to the specified directory, using the same
2076 * semantics as ext4_find_entry(). It returns NULL if it failed.
2077 *
2078 * NOTE!! The inode part of 'de' is left at 0 - which means you
2079 * may not sleep between calling this and putting something into
2080 * the entry, as someone else might have used it while you slept.
2081 */
2082 static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
2083 struct inode *inode)
2084 {
2085 struct inode *dir = d_inode(dentry->d_parent);
2086 struct buffer_head *bh = NULL;
2087 struct ext4_dir_entry_2 *de;
2088 struct ext4_dir_entry_tail *t;
2089 struct super_block *sb;
2090 struct ext4_filename fname;
2091 int retval;
2092 int dx_fallback=0;
2093 unsigned blocksize;
2094 ext4_lblk_t block, blocks;
2095 int csum_size = 0;
2096
2097 if (ext4_has_metadata_csum(inode->i_sb))
2098 csum_size = sizeof(struct ext4_dir_entry_tail);
2099
2100 sb = dir->i_sb;
2101 blocksize = sb->s_blocksize;
2102 if (!dentry->d_name.len)
2103 return -EINVAL;
2104
2105 retval = ext4_fname_setup_filename(dir, &dentry->d_name, 0, &fname);
2106 if (retval)
2107 return retval;
2108
2109 if (ext4_has_inline_data(dir)) {
2110 retval = ext4_try_add_inline_entry(handle, &fname, dir, inode);
2111 if (retval < 0)
2112 goto out;
2113 if (retval == 1) {
2114 retval = 0;
2115 goto out;
2116 }
2117 }
2118
2119 if (is_dx(dir)) {
2120 retval = ext4_dx_add_entry(handle, &fname, dir, inode);
2121 if (!retval || (retval != ERR_BAD_DX_DIR))
2122 goto out;
2123 ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
2124 dx_fallback++;
2125 ext4_mark_inode_dirty(handle, dir);
2126 }
2127 blocks = dir->i_size >> sb->s_blocksize_bits;
2128 for (block = 0; block < blocks; block++) {
2129 bh = ext4_read_dirblock(dir, block, DIRENT);
2130 if (IS_ERR(bh)) {
2131 retval = PTR_ERR(bh);
2132 bh = NULL;
2133 goto out;
2134 }
2135 retval = add_dirent_to_buf(handle, &fname, dir, inode,
2136 NULL, bh);
2137 if (retval != -ENOSPC)
2138 goto out;
2139
2140 if (blocks == 1 && !dx_fallback &&
2141 ext4_has_feature_dir_index(sb)) {
2142 retval = make_indexed_dir(handle, &fname, dir,
2143 inode, bh);
2144 bh = NULL; /* make_indexed_dir releases bh */
2145 goto out;
2146 }
2147 brelse(bh);
2148 }
2149 bh = ext4_append(handle, dir, &block);
2150 if (IS_ERR(bh)) {
2151 retval = PTR_ERR(bh);
2152 bh = NULL;
2153 goto out;
2154 }
2155 de = (struct ext4_dir_entry_2 *) bh->b_data;
2156 de->inode = 0;
2157 de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize);
2158
2159 if (csum_size) {
2160 t = EXT4_DIRENT_TAIL(bh->b_data, blocksize);
2161 initialize_dirent_tail(t, blocksize);
2162 }
2163
2164 retval = add_dirent_to_buf(handle, &fname, dir, inode, de, bh);
2165 out:
2166 ext4_fname_free_filename(&fname);
2167 brelse(bh);
2168 if (retval == 0)
2169 ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY);
2170 return retval;
2171 }
2172
2173 /*
2174 * Returns 0 for success, or a negative error value
2175 */
2176 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
2177 struct inode *dir, struct inode *inode)
2178 {
2179 struct dx_frame frames[2], *frame;
2180 struct dx_entry *entries, *at;
2181 struct buffer_head *bh;
2182 struct super_block *sb = dir->i_sb;
2183 struct ext4_dir_entry_2 *de;
2184 int err;
2185
2186 frame = dx_probe(fname, dir, NULL, frames);
2187 if (IS_ERR(frame))
2188 return PTR_ERR(frame);
2189 entries = frame->entries;
2190 at = frame->at;
2191 bh = ext4_read_dirblock(dir, dx_get_block(frame->at), DIRENT);
2192 if (IS_ERR(bh)) {
2193 err = PTR_ERR(bh);
2194 bh = NULL;
2195 goto cleanup;
2196 }
2197
2198 BUFFER_TRACE(bh, "get_write_access");
2199 err = ext4_journal_get_write_access(handle, bh);
2200 if (err)
2201 goto journal_error;
2202
2203 err = add_dirent_to_buf(handle, fname, dir, inode, NULL, bh);
2204 if (err != -ENOSPC)
2205 goto cleanup;
2206
2207 /* Block full, should compress but for now just split */
2208 dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
2209 dx_get_count(entries), dx_get_limit(entries)));
2210 /* Need to split index? */
2211 if (dx_get_count(entries) == dx_get_limit(entries)) {
2212 ext4_lblk_t newblock;
2213 unsigned icount = dx_get_count(entries);
2214 int levels = frame - frames;
2215 struct dx_entry *entries2;
2216 struct dx_node *node2;
2217 struct buffer_head *bh2;
2218
2219 if (levels && (dx_get_count(frames->entries) ==
2220 dx_get_limit(frames->entries))) {
2221 ext4_warning_inode(dir, "Directory index full!");
2222 err = -ENOSPC;
2223 goto cleanup;
2224 }
2225 bh2 = ext4_append(handle, dir, &newblock);
2226 if (IS_ERR(bh2)) {
2227 err = PTR_ERR(bh2);
2228 goto cleanup;
2229 }
2230 node2 = (struct dx_node *)(bh2->b_data);
2231 entries2 = node2->entries;
2232 memset(&node2->fake, 0, sizeof(struct fake_dirent));
2233 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
2234 sb->s_blocksize);
2235 BUFFER_TRACE(frame->bh, "get_write_access");
2236 err = ext4_journal_get_write_access(handle, frame->bh);
2237 if (err)
2238 goto journal_error;
2239 if (levels) {
2240 unsigned icount1 = icount/2, icount2 = icount - icount1;
2241 unsigned hash2 = dx_get_hash(entries + icount1);
2242 dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
2243 icount1, icount2));
2244
2245 BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
2246 err = ext4_journal_get_write_access(handle,
2247 frames[0].bh);
2248 if (err)
2249 goto journal_error;
2250
2251 memcpy((char *) entries2, (char *) (entries + icount1),
2252 icount2 * sizeof(struct dx_entry));
2253 dx_set_count(entries, icount1);
2254 dx_set_count(entries2, icount2);
2255 dx_set_limit(entries2, dx_node_limit(dir));
2256
2257 /* Which index block gets the new entry? */
2258 if (at - entries >= icount1) {
2259 frame->at = at = at - entries - icount1 + entries2;
2260 frame->entries = entries = entries2;
2261 swap(frame->bh, bh2);
2262 }
2263 dx_insert_block(frames + 0, hash2, newblock);
2264 dxtrace(dx_show_index("node", frames[1].entries));
2265 dxtrace(dx_show_index("node",
2266 ((struct dx_node *) bh2->b_data)->entries));
2267 err = ext4_handle_dirty_dx_node(handle, dir, bh2);
2268 if (err)
2269 goto journal_error;
2270 brelse (bh2);
2271 } else {
2272 dxtrace(printk(KERN_DEBUG
2273 "Creating second level index...\n"));
2274 memcpy((char *) entries2, (char *) entries,
2275 icount * sizeof(struct dx_entry));
2276 dx_set_limit(entries2, dx_node_limit(dir));
2277
2278 /* Set up root */
2279 dx_set_count(entries, 1);
2280 dx_set_block(entries + 0, newblock);
2281 ((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels = 1;
2282
2283 /* Add new access path frame */
2284 frame = frames + 1;
2285 frame->at = at = at - entries + entries2;
2286 frame->entries = entries = entries2;
2287 frame->bh = bh2;
2288 err = ext4_journal_get_write_access(handle,
2289 frame->bh);
2290 if (err)
2291 goto journal_error;
2292 }
2293 err = ext4_handle_dirty_dx_node(handle, dir, frames[0].bh);
2294 if (err) {
2295 ext4_std_error(inode->i_sb, err);
2296 goto cleanup;
2297 }
2298 }
2299 de = do_split(handle, dir, &bh, frame, &fname->hinfo);
2300 if (IS_ERR(de)) {
2301 err = PTR_ERR(de);
2302 goto cleanup;
2303 }
2304 err = add_dirent_to_buf(handle, fname, dir, inode, de, bh);
2305 goto cleanup;
2306
2307 journal_error:
2308 ext4_std_error(dir->i_sb, err);
2309 cleanup:
2310 brelse(bh);
2311 dx_release(frames);
2312 return err;
2313 }
2314
2315 /*
2316 * ext4_generic_delete_entry deletes a directory entry by merging it
2317 * with the previous entry
2318 */
2319 int ext4_generic_delete_entry(handle_t *handle,
2320 struct inode *dir,
2321 struct ext4_dir_entry_2 *de_del,
2322 struct buffer_head *bh,
2323 void *entry_buf,
2324 int buf_size,
2325 int csum_size)
2326 {
2327 struct ext4_dir_entry_2 *de, *pde;
2328 unsigned int blocksize = dir->i_sb->s_blocksize;
2329 int i;
2330
2331 i = 0;
2332 pde = NULL;
2333 de = (struct ext4_dir_entry_2 *)entry_buf;
2334 while (i < buf_size - csum_size) {
2335 if (ext4_check_dir_entry(dir, NULL, de, bh,
2336 bh->b_data, bh->b_size, i))
2337 return -EFSCORRUPTED;
2338 if (de == de_del) {
2339 if (pde)
2340 pde->rec_len = ext4_rec_len_to_disk(
2341 ext4_rec_len_from_disk(pde->rec_len,
2342 blocksize) +
2343 ext4_rec_len_from_disk(de->rec_len,
2344 blocksize),
2345 blocksize);
2346 else
2347 de->inode = 0;
2348 dir->i_version++;
2349 return 0;
2350 }
2351 i += ext4_rec_len_from_disk(de->rec_len, blocksize);
2352 pde = de;
2353 de = ext4_next_entry(de, blocksize);
2354 }
2355 return -ENOENT;
2356 }
2357
2358 static int ext4_delete_entry(handle_t *handle,
2359 struct inode *dir,
2360 struct ext4_dir_entry_2 *de_del,
2361 struct buffer_head *bh)
2362 {
2363 int err, csum_size = 0;
2364
2365 if (ext4_has_inline_data(dir)) {
2366 int has_inline_data = 1;
2367 err = ext4_delete_inline_entry(handle, dir, de_del, bh,
2368 &has_inline_data);
2369 if (has_inline_data)
2370 return err;
2371 }
2372
2373 if (ext4_has_metadata_csum(dir->i_sb))
2374 csum_size = sizeof(struct ext4_dir_entry_tail);
2375
2376 BUFFER_TRACE(bh, "get_write_access");
2377 err = ext4_journal_get_write_access(handle, bh);
2378 if (unlikely(err))
2379 goto out;
2380
2381 err = ext4_generic_delete_entry(handle, dir, de_del,
2382 bh, bh->b_data,
2383 dir->i_sb->s_blocksize, csum_size);
2384 if (err)
2385 goto out;
2386
2387 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
2388 err = ext4_handle_dirty_dirent_node(handle, dir, bh);
2389 if (unlikely(err))
2390 goto out;
2391
2392 return 0;
2393 out:
2394 if (err != -ENOENT)
2395 ext4_std_error(dir->i_sb, err);
2396 return err;
2397 }
2398
2399 /*
2400 * DIR_NLINK feature is set if 1) nlinks > EXT4_LINK_MAX or 2) nlinks == 2,
2401 * since this indicates that nlinks count was previously 1.
2402 */
2403 static void ext4_inc_count(handle_t *handle, struct inode *inode)
2404 {
2405 inc_nlink(inode);
2406 if (is_dx(inode) && inode->i_nlink > 1) {
2407 /* limit is 16-bit i_links_count */
2408 if (inode->i_nlink >= EXT4_LINK_MAX || inode->i_nlink == 2) {
2409 set_nlink(inode, 1);
2410 ext4_set_feature_dir_nlink(inode->i_sb);
2411 }
2412 }
2413 }
2414
2415 /*
2416 * If a directory had nlink == 1, then we should let it be 1. This indicates
2417 * directory has >EXT4_LINK_MAX subdirs.
2418 */
2419 static void ext4_dec_count(handle_t *handle, struct inode *inode)
2420 {
2421 if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
2422 drop_nlink(inode);
2423 }
2424
2425
2426 static int ext4_add_nondir(handle_t *handle,
2427 struct dentry *dentry, struct inode *inode)
2428 {
2429 int err = ext4_add_entry(handle, dentry, inode);
2430 if (!err) {
2431 ext4_mark_inode_dirty(handle, inode);
2432 unlock_new_inode(inode);
2433 d_instantiate(dentry, inode);
2434 return 0;
2435 }
2436 drop_nlink(inode);
2437 unlock_new_inode(inode);
2438 iput(inode);
2439 return err;
2440 }
2441
2442 /*
2443 * By the time this is called, we already have created
2444 * the directory cache entry for the new file, but it
2445 * is so far negative - it has no inode.
2446 *
2447 * If the create succeeds, we fill in the inode information
2448 * with d_instantiate().
2449 */
2450 static int ext4_create(struct inode *dir, struct dentry *dentry, umode_t mode,
2451 bool excl)
2452 {
2453 handle_t *handle;
2454 struct inode *inode;
2455 int err, credits, retries = 0;
2456
2457 err = dquot_initialize(dir);
2458 if (err)
2459 return err;
2460
2461 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2462 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2463 retry:
2464 inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
2465 NULL, EXT4_HT_DIR, credits);
2466 handle = ext4_journal_current_handle();
2467 err = PTR_ERR(inode);
2468 if (!IS_ERR(inode)) {
2469 inode->i_op = &ext4_file_inode_operations;
2470 inode->i_fop = &ext4_file_operations;
2471 ext4_set_aops(inode);
2472 err = ext4_add_nondir(handle, dentry, inode);
2473 if (!err && IS_DIRSYNC(dir))
2474 ext4_handle_sync(handle);
2475 }
2476 if (handle)
2477 ext4_journal_stop(handle);
2478 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2479 goto retry;
2480 return err;
2481 }
2482
2483 static int ext4_mknod(struct inode *dir, struct dentry *dentry,
2484 umode_t mode, dev_t rdev)
2485 {
2486 handle_t *handle;
2487 struct inode *inode;
2488 int err, credits, retries = 0;
2489
2490 err = dquot_initialize(dir);
2491 if (err)
2492 return err;
2493
2494 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2495 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2496 retry:
2497 inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
2498 NULL, EXT4_HT_DIR, credits);
2499 handle = ext4_journal_current_handle();
2500 err = PTR_ERR(inode);
2501 if (!IS_ERR(inode)) {
2502 init_special_inode(inode, inode->i_mode, rdev);
2503 inode->i_op = &ext4_special_inode_operations;
2504 err = ext4_add_nondir(handle, dentry, inode);
2505 if (!err && IS_DIRSYNC(dir))
2506 ext4_handle_sync(handle);
2507 }
2508 if (handle)
2509 ext4_journal_stop(handle);
2510 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2511 goto retry;
2512 return err;
2513 }
2514
2515 static int ext4_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
2516 {
2517 handle_t *handle;
2518 struct inode *inode;
2519 int err, retries = 0;
2520
2521 err = dquot_initialize(dir);
2522 if (err)
2523 return err;
2524
2525 retry:
2526 inode = ext4_new_inode_start_handle(dir, mode,
2527 NULL, 0, NULL,
2528 EXT4_HT_DIR,
2529 EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
2530 4 + EXT4_XATTR_TRANS_BLOCKS);
2531 handle = ext4_journal_current_handle();
2532 err = PTR_ERR(inode);
2533 if (!IS_ERR(inode)) {
2534 inode->i_op = &ext4_file_inode_operations;
2535 inode->i_fop = &ext4_file_operations;
2536 ext4_set_aops(inode);
2537 d_tmpfile(dentry, inode);
2538 err = ext4_orphan_add(handle, inode);
2539 if (err)
2540 goto err_unlock_inode;
2541 mark_inode_dirty(inode);
2542 unlock_new_inode(inode);
2543 }
2544 if (handle)
2545 ext4_journal_stop(handle);
2546 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2547 goto retry;
2548 return err;
2549 err_unlock_inode:
2550 ext4_journal_stop(handle);
2551 unlock_new_inode(inode);
2552 return err;
2553 }
2554
2555 struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
2556 struct ext4_dir_entry_2 *de,
2557 int blocksize, int csum_size,
2558 unsigned int parent_ino, int dotdot_real_len)
2559 {
2560 de->inode = cpu_to_le32(inode->i_ino);
2561 de->name_len = 1;
2562 de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
2563 blocksize);
2564 strcpy(de->name, ".");
2565 ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2566
2567 de = ext4_next_entry(de, blocksize);
2568 de->inode = cpu_to_le32(parent_ino);
2569 de->name_len = 2;
2570 if (!dotdot_real_len)
2571 de->rec_len = ext4_rec_len_to_disk(blocksize -
2572 (csum_size + EXT4_DIR_REC_LEN(1)),
2573 blocksize);
2574 else
2575 de->rec_len = ext4_rec_len_to_disk(
2576 EXT4_DIR_REC_LEN(de->name_len), blocksize);
2577 strcpy(de->name, "..");
2578 ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2579
2580 return ext4_next_entry(de, blocksize);
2581 }
2582
2583 static int ext4_init_new_dir(handle_t *handle, struct inode *dir,
2584 struct inode *inode)
2585 {
2586 struct buffer_head *dir_block = NULL;
2587 struct ext4_dir_entry_2 *de;
2588 struct ext4_dir_entry_tail *t;
2589 ext4_lblk_t block = 0;
2590 unsigned int blocksize = dir->i_sb->s_blocksize;
2591 int csum_size = 0;
2592 int err;
2593
2594 if (ext4_has_metadata_csum(dir->i_sb))
2595 csum_size = sizeof(struct ext4_dir_entry_tail);
2596
2597 if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
2598 err = ext4_try_create_inline_dir(handle, dir, inode);
2599 if (err < 0 && err != -ENOSPC)
2600 goto out;
2601 if (!err)
2602 goto out;
2603 }
2604
2605 inode->i_size = 0;
2606 dir_block = ext4_append(handle, inode, &block);
2607 if (IS_ERR(dir_block))
2608 return PTR_ERR(dir_block);
2609 de = (struct ext4_dir_entry_2 *)dir_block->b_data;
2610 ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0);
2611 set_nlink(inode, 2);
2612 if (csum_size) {
2613 t = EXT4_DIRENT_TAIL(dir_block->b_data, blocksize);
2614 initialize_dirent_tail(t, blocksize);
2615 }
2616
2617 BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
2618 err = ext4_handle_dirty_dirent_node(handle, inode, dir_block);
2619 if (err)
2620 goto out;
2621 set_buffer_verified(dir_block);
2622 out:
2623 brelse(dir_block);
2624 return err;
2625 }
2626
2627 static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
2628 {
2629 handle_t *handle;
2630 struct inode *inode;
2631 int err, credits, retries = 0;
2632
2633 if (EXT4_DIR_LINK_MAX(dir))
2634 return -EMLINK;
2635
2636 err = dquot_initialize(dir);
2637 if (err)
2638 return err;
2639
2640 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2641 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2642 retry:
2643 inode = ext4_new_inode_start_handle(dir, S_IFDIR | mode,
2644 &dentry->d_name,
2645 0, NULL, EXT4_HT_DIR, credits);
2646 handle = ext4_journal_current_handle();
2647 err = PTR_ERR(inode);
2648 if (IS_ERR(inode))
2649 goto out_stop;
2650
2651 inode->i_op = &ext4_dir_inode_operations;
2652 inode->i_fop = &ext4_dir_operations;
2653 err = ext4_init_new_dir(handle, dir, inode);
2654 if (err)
2655 goto out_clear_inode;
2656 err = ext4_mark_inode_dirty(handle, inode);
2657 if (!err)
2658 err = ext4_add_entry(handle, dentry, inode);
2659 if (err) {
2660 out_clear_inode:
2661 clear_nlink(inode);
2662 unlock_new_inode(inode);
2663 ext4_mark_inode_dirty(handle, inode);
2664 iput(inode);
2665 goto out_stop;
2666 }
2667 ext4_inc_count(handle, dir);
2668 ext4_update_dx_flag(dir);
2669 err = ext4_mark_inode_dirty(handle, dir);
2670 if (err)
2671 goto out_clear_inode;
2672 unlock_new_inode(inode);
2673 d_instantiate(dentry, inode);
2674 if (IS_DIRSYNC(dir))
2675 ext4_handle_sync(handle);
2676
2677 out_stop:
2678 if (handle)
2679 ext4_journal_stop(handle);
2680 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2681 goto retry;
2682 return err;
2683 }
2684
2685 /*
2686 * routine to check that the specified directory is empty (for rmdir)
2687 */
2688 int ext4_empty_dir(struct inode *inode)
2689 {
2690 unsigned int offset;
2691 struct buffer_head *bh;
2692 struct ext4_dir_entry_2 *de, *de1;
2693 struct super_block *sb;
2694 int err = 0;
2695
2696 if (ext4_has_inline_data(inode)) {
2697 int has_inline_data = 1;
2698
2699 err = empty_inline_dir(inode, &has_inline_data);
2700 if (has_inline_data)
2701 return err;
2702 }
2703
2704 sb = inode->i_sb;
2705 if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2)) {
2706 EXT4_ERROR_INODE(inode, "invalid size");
2707 return 1;
2708 }
2709 bh = ext4_read_dirblock(inode, 0, EITHER);
2710 if (IS_ERR(bh))
2711 return 1;
2712
2713 de = (struct ext4_dir_entry_2 *) bh->b_data;
2714 de1 = ext4_next_entry(de, sb->s_blocksize);
2715 if (le32_to_cpu(de->inode) != inode->i_ino ||
2716 le32_to_cpu(de1->inode) == 0 ||
2717 strcmp(".", de->name) || strcmp("..", de1->name)) {
2718 ext4_warning_inode(inode, "directory missing '.' and/or '..'");
2719 brelse(bh);
2720 return 1;
2721 }
2722 offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) +
2723 ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize);
2724 de = ext4_next_entry(de1, sb->s_blocksize);
2725 while (offset < inode->i_size) {
2726 if ((void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
2727 unsigned int lblock;
2728 err = 0;
2729 brelse(bh);
2730 lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb);
2731 bh = ext4_read_dirblock(inode, lblock, EITHER);
2732 if (IS_ERR(bh))
2733 return 1;
2734 de = (struct ext4_dir_entry_2 *) bh->b_data;
2735 }
2736 if (ext4_check_dir_entry(inode, NULL, de, bh,
2737 bh->b_data, bh->b_size, offset)) {
2738 de = (struct ext4_dir_entry_2 *)(bh->b_data +
2739 sb->s_blocksize);
2740 offset = (offset | (sb->s_blocksize - 1)) + 1;
2741 continue;
2742 }
2743 if (le32_to_cpu(de->inode)) {
2744 brelse(bh);
2745 return 0;
2746 }
2747 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
2748 de = ext4_next_entry(de, sb->s_blocksize);
2749 }
2750 brelse(bh);
2751 return 1;
2752 }
2753
2754 /*
2755 * ext4_orphan_add() links an unlinked or truncated inode into a list of
2756 * such inodes, starting at the superblock, in case we crash before the
2757 * file is closed/deleted, or in case the inode truncate spans multiple
2758 * transactions and the last transaction is not recovered after a crash.
2759 *
2760 * At filesystem recovery time, we walk this list deleting unlinked
2761 * inodes and truncating linked inodes in ext4_orphan_cleanup().
2762 *
2763 * Orphan list manipulation functions must be called under i_mutex unless
2764 * we are just creating the inode or deleting it.
2765 */
2766 int ext4_orphan_add(handle_t *handle, struct inode *inode)
2767 {
2768 struct super_block *sb = inode->i_sb;
2769 struct ext4_sb_info *sbi = EXT4_SB(sb);
2770 struct ext4_iloc iloc;
2771 int err = 0, rc;
2772 bool dirty = false;
2773
2774 if (!sbi->s_journal || is_bad_inode(inode))
2775 return 0;
2776
2777 WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
2778 !inode_is_locked(inode));
2779 /*
2780 * Exit early if inode already is on orphan list. This is a big speedup
2781 * since we don't have to contend on the global s_orphan_lock.
2782 */
2783 if (!list_empty(&EXT4_I(inode)->i_orphan))
2784 return 0;
2785
2786 /*
2787 * Orphan handling is only valid for files with data blocks
2788 * being truncated, or files being unlinked. Note that we either
2789 * hold i_mutex, or the inode can not be referenced from outside,
2790 * so i_nlink should not be bumped due to race
2791 */
2792 J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2793 S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
2794
2795 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2796 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2797 if (err)
2798 goto out;
2799
2800 err = ext4_reserve_inode_write(handle, inode, &iloc);
2801 if (err)
2802 goto out;
2803
2804 mutex_lock(&sbi->s_orphan_lock);
2805 /*
2806 * Due to previous errors inode may be already a part of on-disk
2807 * orphan list. If so skip on-disk list modification.
2808 */
2809 if (!NEXT_ORPHAN(inode) || NEXT_ORPHAN(inode) >
2810 (le32_to_cpu(sbi->s_es->s_inodes_count))) {
2811 /* Insert this inode at the head of the on-disk orphan list */
2812 NEXT_ORPHAN(inode) = le32_to_cpu(sbi->s_es->s_last_orphan);
2813 sbi->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
2814 dirty = true;
2815 }
2816 list_add(&EXT4_I(inode)->i_orphan, &sbi->s_orphan);
2817 mutex_unlock(&sbi->s_orphan_lock);
2818
2819 if (dirty) {
2820 err = ext4_handle_dirty_super(handle, sb);
2821 rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
2822 if (!err)
2823 err = rc;
2824 if (err) {
2825 /*
2826 * We have to remove inode from in-memory list if
2827 * addition to on disk orphan list failed. Stray orphan
2828 * list entries can cause panics at unmount time.
2829 */
2830 mutex_lock(&sbi->s_orphan_lock);
2831 list_del(&EXT4_I(inode)->i_orphan);
2832 mutex_unlock(&sbi->s_orphan_lock);
2833 }
2834 }
2835 jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
2836 jbd_debug(4, "orphan inode %lu will point to %d\n",
2837 inode->i_ino, NEXT_ORPHAN(inode));
2838 out:
2839 ext4_std_error(sb, err);
2840 return err;
2841 }
2842
2843 /*
2844 * ext4_orphan_del() removes an unlinked or truncated inode from the list
2845 * of such inodes stored on disk, because it is finally being cleaned up.
2846 */
2847 int ext4_orphan_del(handle_t *handle, struct inode *inode)
2848 {
2849 struct list_head *prev;
2850 struct ext4_inode_info *ei = EXT4_I(inode);
2851 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2852 __u32 ino_next;
2853 struct ext4_iloc iloc;
2854 int err = 0;
2855
2856 if (!sbi->s_journal && !(sbi->s_mount_state & EXT4_ORPHAN_FS))
2857 return 0;
2858
2859 WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
2860 !inode_is_locked(inode));
2861 /* Do this quick check before taking global s_orphan_lock. */
2862 if (list_empty(&ei->i_orphan))
2863 return 0;
2864
2865 if (handle) {
2866 /* Grab inode buffer early before taking global s_orphan_lock */
2867 err = ext4_reserve_inode_write(handle, inode, &iloc);
2868 }
2869
2870 mutex_lock(&sbi->s_orphan_lock);
2871 jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
2872
2873 prev = ei->i_orphan.prev;
2874 list_del_init(&ei->i_orphan);
2875
2876 /* If we're on an error path, we may not have a valid
2877 * transaction handle with which to update the orphan list on
2878 * disk, but we still need to remove the inode from the linked
2879 * list in memory. */
2880 if (!handle || err) {
2881 mutex_unlock(&sbi->s_orphan_lock);
2882 goto out_err;
2883 }
2884
2885 ino_next = NEXT_ORPHAN(inode);
2886 if (prev == &sbi->s_orphan) {
2887 jbd_debug(4, "superblock will point to %u\n", ino_next);
2888 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2889 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2890 if (err) {
2891 mutex_unlock(&sbi->s_orphan_lock);
2892 goto out_brelse;
2893 }
2894 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
2895 mutex_unlock(&sbi->s_orphan_lock);
2896 err = ext4_handle_dirty_super(handle, inode->i_sb);
2897 } else {
2898 struct ext4_iloc iloc2;
2899 struct inode *i_prev =
2900 &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
2901
2902 jbd_debug(4, "orphan inode %lu will point to %u\n",
2903 i_prev->i_ino, ino_next);
2904 err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
2905 if (err) {
2906 mutex_unlock(&sbi->s_orphan_lock);
2907 goto out_brelse;
2908 }
2909 NEXT_ORPHAN(i_prev) = ino_next;
2910 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
2911 mutex_unlock(&sbi->s_orphan_lock);
2912 }
2913 if (err)
2914 goto out_brelse;
2915 NEXT_ORPHAN(inode) = 0;
2916 err = ext4_mark_iloc_dirty(handle, inode, &iloc);
2917 out_err:
2918 ext4_std_error(inode->i_sb, err);
2919 return err;
2920
2921 out_brelse:
2922 brelse(iloc.bh);
2923 goto out_err;
2924 }
2925
2926 static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
2927 {
2928 int retval;
2929 struct inode *inode;
2930 struct buffer_head *bh;
2931 struct ext4_dir_entry_2 *de;
2932 handle_t *handle = NULL;
2933
2934 /* Initialize quotas before so that eventual writes go in
2935 * separate transaction */
2936 retval = dquot_initialize(dir);
2937 if (retval)
2938 return retval;
2939 retval = dquot_initialize(d_inode(dentry));
2940 if (retval)
2941 return retval;
2942
2943 retval = -ENOENT;
2944 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
2945 if (IS_ERR(bh))
2946 return PTR_ERR(bh);
2947 if (!bh)
2948 goto end_rmdir;
2949
2950 inode = d_inode(dentry);
2951
2952 retval = -EFSCORRUPTED;
2953 if (le32_to_cpu(de->inode) != inode->i_ino)
2954 goto end_rmdir;
2955
2956 retval = -ENOTEMPTY;
2957 if (!ext4_empty_dir(inode))
2958 goto end_rmdir;
2959
2960 handle = ext4_journal_start(dir, EXT4_HT_DIR,
2961 EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
2962 if (IS_ERR(handle)) {
2963 retval = PTR_ERR(handle);
2964 handle = NULL;
2965 goto end_rmdir;
2966 }
2967
2968 if (IS_DIRSYNC(dir))
2969 ext4_handle_sync(handle);
2970
2971 retval = ext4_delete_entry(handle, dir, de, bh);
2972 if (retval)
2973 goto end_rmdir;
2974 if (!EXT4_DIR_LINK_EMPTY(inode))
2975 ext4_warning_inode(inode,
2976 "empty directory '%.*s' has too many links (%u)",
2977 dentry->d_name.len, dentry->d_name.name,
2978 inode->i_nlink);
2979 inode->i_version++;
2980 clear_nlink(inode);
2981 /* There's no need to set i_disksize: the fact that i_nlink is
2982 * zero will ensure that the right thing happens during any
2983 * recovery. */
2984 inode->i_size = 0;
2985 ext4_orphan_add(handle, inode);
2986 inode->i_ctime = dir->i_ctime = dir->i_mtime = ext4_current_time(inode);
2987 ext4_mark_inode_dirty(handle, inode);
2988 ext4_dec_count(handle, dir);
2989 ext4_update_dx_flag(dir);
2990 ext4_mark_inode_dirty(handle, dir);
2991
2992 end_rmdir:
2993 brelse(bh);
2994 if (handle)
2995 ext4_journal_stop(handle);
2996 return retval;
2997 }
2998
2999 static int ext4_unlink(struct inode *dir, struct dentry *dentry)
3000 {
3001 int retval;
3002 struct inode *inode;
3003 struct buffer_head *bh;
3004 struct ext4_dir_entry_2 *de;
3005 handle_t *handle = NULL;
3006
3007 trace_ext4_unlink_enter(dir, dentry);
3008 /* Initialize quotas before so that eventual writes go
3009 * in separate transaction */
3010 retval = dquot_initialize(dir);
3011 if (retval)
3012 return retval;
3013 retval = dquot_initialize(d_inode(dentry));
3014 if (retval)
3015 return retval;
3016
3017 retval = -ENOENT;
3018 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
3019 if (IS_ERR(bh))
3020 return PTR_ERR(bh);
3021 if (!bh)
3022 goto end_unlink;
3023
3024 inode = d_inode(dentry);
3025
3026 retval = -EFSCORRUPTED;
3027 if (le32_to_cpu(de->inode) != inode->i_ino)
3028 goto end_unlink;
3029
3030 handle = ext4_journal_start(dir, EXT4_HT_DIR,
3031 EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
3032 if (IS_ERR(handle)) {
3033 retval = PTR_ERR(handle);
3034 handle = NULL;
3035 goto end_unlink;
3036 }
3037
3038 if (IS_DIRSYNC(dir))
3039 ext4_handle_sync(handle);
3040
3041 if (inode->i_nlink == 0) {
3042 ext4_warning_inode(inode, "Deleting file '%.*s' with no links",
3043 dentry->d_name.len, dentry->d_name.name);
3044 set_nlink(inode, 1);
3045 }
3046 retval = ext4_delete_entry(handle, dir, de, bh);
3047 if (retval)
3048 goto end_unlink;
3049 dir->i_ctime = dir->i_mtime = ext4_current_time(dir);
3050 ext4_update_dx_flag(dir);
3051 ext4_mark_inode_dirty(handle, dir);
3052 drop_nlink(inode);
3053 if (!inode->i_nlink)
3054 ext4_orphan_add(handle, inode);
3055 inode->i_ctime = ext4_current_time(inode);
3056 ext4_mark_inode_dirty(handle, inode);
3057
3058 end_unlink:
3059 brelse(bh);
3060 if (handle)
3061 ext4_journal_stop(handle);
3062 trace_ext4_unlink_exit(dentry, retval);
3063 return retval;
3064 }
3065
3066 static int ext4_symlink(struct inode *dir,
3067 struct dentry *dentry, const char *symname)
3068 {
3069 handle_t *handle;
3070 struct inode *inode;
3071 int err, len = strlen(symname);
3072 int credits;
3073 bool encryption_required;
3074 struct ext4_str disk_link;
3075 struct ext4_encrypted_symlink_data *sd = NULL;
3076
3077 disk_link.len = len + 1;
3078 disk_link.name = (char *) symname;
3079
3080 encryption_required = (ext4_encrypted_inode(dir) ||
3081 DUMMY_ENCRYPTION_ENABLED(EXT4_SB(dir->i_sb)));
3082 if (encryption_required) {
3083 err = ext4_get_encryption_info(dir);
3084 if (err)
3085 return err;
3086 if (ext4_encryption_info(dir) == NULL)
3087 return -EPERM;
3088 disk_link.len = (ext4_fname_encrypted_size(dir, len) +
3089 sizeof(struct ext4_encrypted_symlink_data));
3090 sd = kzalloc(disk_link.len, GFP_KERNEL);
3091 if (!sd)
3092 return -ENOMEM;
3093 }
3094
3095 if (disk_link.len > dir->i_sb->s_blocksize) {
3096 err = -ENAMETOOLONG;
3097 goto err_free_sd;
3098 }
3099
3100 err = dquot_initialize(dir);
3101 if (err)
3102 goto err_free_sd;
3103
3104 if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
3105 /*
3106 * For non-fast symlinks, we just allocate inode and put it on
3107 * orphan list in the first transaction => we need bitmap,
3108 * group descriptor, sb, inode block, quota blocks, and
3109 * possibly selinux xattr blocks.
3110 */
3111 credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
3112 EXT4_XATTR_TRANS_BLOCKS;
3113 } else {
3114 /*
3115 * Fast symlink. We have to add entry to directory
3116 * (EXT4_DATA_TRANS_BLOCKS + EXT4_INDEX_EXTRA_TRANS_BLOCKS),
3117 * allocate new inode (bitmap, group descriptor, inode block,
3118 * quota blocks, sb is already counted in previous macros).
3119 */
3120 credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3121 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3;
3122 }
3123
3124 inode = ext4_new_inode_start_handle(dir, S_IFLNK|S_IRWXUGO,
3125 &dentry->d_name, 0, NULL,
3126 EXT4_HT_DIR, credits);
3127 handle = ext4_journal_current_handle();
3128 if (IS_ERR(inode)) {
3129 if (handle)
3130 ext4_journal_stop(handle);
3131 err = PTR_ERR(inode);
3132 goto err_free_sd;
3133 }
3134
3135 if (encryption_required) {
3136 struct qstr istr;
3137 struct ext4_str ostr;
3138
3139 istr.name = (const unsigned char *) symname;
3140 istr.len = len;
3141 ostr.name = sd->encrypted_path;
3142 ostr.len = disk_link.len;
3143 err = ext4_fname_usr_to_disk(inode, &istr, &ostr);
3144 if (err < 0)
3145 goto err_drop_inode;
3146 sd->len = cpu_to_le16(ostr.len);
3147 disk_link.name = (char *) sd;
3148 inode->i_op = &ext4_encrypted_symlink_inode_operations;
3149 }
3150
3151 if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
3152 if (!encryption_required)
3153 inode->i_op = &ext4_symlink_inode_operations;
3154 inode_nohighmem(inode);
3155 ext4_set_aops(inode);
3156 /*
3157 * We cannot call page_symlink() with transaction started
3158 * because it calls into ext4_write_begin() which can wait
3159 * for transaction commit if we are running out of space
3160 * and thus we deadlock. So we have to stop transaction now
3161 * and restart it when symlink contents is written.
3162 *
3163 * To keep fs consistent in case of crash, we have to put inode
3164 * to orphan list in the mean time.
3165 */
3166 drop_nlink(inode);
3167 err = ext4_orphan_add(handle, inode);
3168 ext4_journal_stop(handle);
3169 handle = NULL;
3170 if (err)
3171 goto err_drop_inode;
3172 err = __page_symlink(inode, disk_link.name, disk_link.len, 1);
3173 if (err)
3174 goto err_drop_inode;
3175 /*
3176 * Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS
3177 * + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified
3178 */
3179 handle = ext4_journal_start(dir, EXT4_HT_DIR,
3180 EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3181 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1);
3182 if (IS_ERR(handle)) {
3183 err = PTR_ERR(handle);
3184 handle = NULL;
3185 goto err_drop_inode;
3186 }
3187 set_nlink(inode, 1);
3188 err = ext4_orphan_del(handle, inode);
3189 if (err)
3190 goto err_drop_inode;
3191 } else {
3192 /* clear the extent format for fast symlink */
3193 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
3194 if (!encryption_required) {
3195 inode->i_op = &ext4_fast_symlink_inode_operations;
3196 inode->i_link = (char *)&EXT4_I(inode)->i_data;
3197 }
3198 memcpy((char *)&EXT4_I(inode)->i_data, disk_link.name,
3199 disk_link.len);
3200 inode->i_size = disk_link.len - 1;
3201 }
3202 EXT4_I(inode)->i_disksize = inode->i_size;
3203 err = ext4_add_nondir(handle, dentry, inode);
3204 if (!err && IS_DIRSYNC(dir))
3205 ext4_handle_sync(handle);
3206
3207 if (handle)
3208 ext4_journal_stop(handle);
3209 kfree(sd);
3210 return err;
3211 err_drop_inode:
3212 if (handle)
3213 ext4_journal_stop(handle);
3214 clear_nlink(inode);
3215 unlock_new_inode(inode);
3216 iput(inode);
3217 err_free_sd:
3218 kfree(sd);
3219 return err;
3220 }
3221
3222 static int ext4_link(struct dentry *old_dentry,
3223 struct inode *dir, struct dentry *dentry)
3224 {
3225 handle_t *handle;
3226 struct inode *inode = d_inode(old_dentry);
3227 int err, retries = 0;
3228
3229 if (inode->i_nlink >= EXT4_LINK_MAX)
3230 return -EMLINK;
3231 if (ext4_encrypted_inode(dir) &&
3232 !ext4_is_child_context_consistent_with_parent(dir, inode))
3233 return -EPERM;
3234
3235 if ((ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT)) &&
3236 (!projid_eq(EXT4_I(dir)->i_projid,
3237 EXT4_I(old_dentry->d_inode)->i_projid)))
3238 return -EXDEV;
3239
3240 err = dquot_initialize(dir);
3241 if (err)
3242 return err;
3243
3244 retry:
3245 handle = ext4_journal_start(dir, EXT4_HT_DIR,
3246 (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3247 EXT4_INDEX_EXTRA_TRANS_BLOCKS) + 1);
3248 if (IS_ERR(handle))
3249 return PTR_ERR(handle);
3250
3251 if (IS_DIRSYNC(dir))
3252 ext4_handle_sync(handle);
3253
3254 inode->i_ctime = ext4_current_time(inode);
3255 ext4_inc_count(handle, inode);
3256 ihold(inode);
3257
3258 err = ext4_add_entry(handle, dentry, inode);
3259 if (!err) {
3260 ext4_mark_inode_dirty(handle, inode);
3261 /* this can happen only for tmpfile being
3262 * linked the first time
3263 */
3264 if (inode->i_nlink == 1)
3265 ext4_orphan_del(handle, inode);
3266 d_instantiate(dentry, inode);
3267 } else {
3268 drop_nlink(inode);
3269 iput(inode);
3270 }
3271 ext4_journal_stop(handle);
3272 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
3273 goto retry;
3274 return err;
3275 }
3276
3277
3278 /*
3279 * Try to find buffer head where contains the parent block.
3280 * It should be the inode block if it is inlined or the 1st block
3281 * if it is a normal dir.
3282 */
3283 static struct buffer_head *ext4_get_first_dir_block(handle_t *handle,
3284 struct inode *inode,
3285 int *retval,
3286 struct ext4_dir_entry_2 **parent_de,
3287 int *inlined)
3288 {
3289 struct buffer_head *bh;
3290
3291 if (!ext4_has_inline_data(inode)) {
3292 bh = ext4_read_dirblock(inode, 0, EITHER);
3293 if (IS_ERR(bh)) {
3294 *retval = PTR_ERR(bh);
3295 return NULL;
3296 }
3297 *parent_de = ext4_next_entry(
3298 (struct ext4_dir_entry_2 *)bh->b_data,
3299 inode->i_sb->s_blocksize);
3300 return bh;
3301 }
3302
3303 *inlined = 1;
3304 return ext4_get_first_inline_block(inode, parent_de, retval);
3305 }
3306
3307 struct ext4_renament {
3308 struct inode *dir;
3309 struct dentry *dentry;
3310 struct inode *inode;
3311 bool is_dir;
3312 int dir_nlink_delta;
3313
3314 /* entry for "dentry" */
3315 struct buffer_head *bh;
3316 struct ext4_dir_entry_2 *de;
3317 int inlined;
3318
3319 /* entry for ".." in inode if it's a directory */
3320 struct buffer_head *dir_bh;
3321 struct ext4_dir_entry_2 *parent_de;
3322 int dir_inlined;
3323 };
3324
3325 static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent)
3326 {
3327 int retval;
3328
3329 ent->dir_bh = ext4_get_first_dir_block(handle, ent->inode,
3330 &retval, &ent->parent_de,
3331 &ent->dir_inlined);
3332 if (!ent->dir_bh)
3333 return retval;
3334 if (le32_to_cpu(ent->parent_de->inode) != ent->dir->i_ino)
3335 return -EFSCORRUPTED;
3336 BUFFER_TRACE(ent->dir_bh, "get_write_access");
3337 return ext4_journal_get_write_access(handle, ent->dir_bh);
3338 }
3339
3340 static int ext4_rename_dir_finish(handle_t *handle, struct ext4_renament *ent,
3341 unsigned dir_ino)
3342 {
3343 int retval;
3344
3345 ent->parent_de->inode = cpu_to_le32(dir_ino);
3346 BUFFER_TRACE(ent->dir_bh, "call ext4_handle_dirty_metadata");
3347 if (!ent->dir_inlined) {
3348 if (is_dx(ent->inode)) {
3349 retval = ext4_handle_dirty_dx_node(handle,
3350 ent->inode,
3351 ent->dir_bh);
3352 } else {
3353 retval = ext4_handle_dirty_dirent_node(handle,
3354 ent->inode,
3355 ent->dir_bh);
3356 }
3357 } else {
3358 retval = ext4_mark_inode_dirty(handle, ent->inode);
3359 }
3360 if (retval) {
3361 ext4_std_error(ent->dir->i_sb, retval);
3362 return retval;
3363 }
3364 return 0;
3365 }
3366
3367 static int ext4_setent(handle_t *handle, struct ext4_renament *ent,
3368 unsigned ino, unsigned file_type)
3369 {
3370 int retval;
3371
3372 BUFFER_TRACE(ent->bh, "get write access");
3373 retval = ext4_journal_get_write_access(handle, ent->bh);
3374 if (retval)
3375 return retval;
3376 ent->de->inode = cpu_to_le32(ino);
3377 if (ext4_has_feature_filetype(ent->dir->i_sb))
3378 ent->de->file_type = file_type;
3379 ent->dir->i_version++;
3380 ent->dir->i_ctime = ent->dir->i_mtime =
3381 ext4_current_time(ent->dir);
3382 ext4_mark_inode_dirty(handle, ent->dir);
3383 BUFFER_TRACE(ent->bh, "call ext4_handle_dirty_metadata");
3384 if (!ent->inlined) {
3385 retval = ext4_handle_dirty_dirent_node(handle,
3386 ent->dir, ent->bh);
3387 if (unlikely(retval)) {
3388 ext4_std_error(ent->dir->i_sb, retval);
3389 return retval;
3390 }
3391 }
3392 brelse(ent->bh);
3393 ent->bh = NULL;
3394
3395 return 0;
3396 }
3397
3398 static int ext4_find_delete_entry(handle_t *handle, struct inode *dir,
3399 const struct qstr *d_name)
3400 {
3401 int retval = -ENOENT;
3402 struct buffer_head *bh;
3403 struct ext4_dir_entry_2 *de;
3404
3405 bh = ext4_find_entry(dir, d_name, &de, NULL);
3406 if (IS_ERR(bh))
3407 return PTR_ERR(bh);
3408 if (bh) {
3409 retval = ext4_delete_entry(handle, dir, de, bh);
3410 brelse(bh);
3411 }
3412 return retval;
3413 }
3414
3415 static void ext4_rename_delete(handle_t *handle, struct ext4_renament *ent,
3416 int force_reread)
3417 {
3418 int retval;
3419 /*
3420 * ent->de could have moved from under us during htree split, so make
3421 * sure that we are deleting the right entry. We might also be pointing
3422 * to a stale entry in the unused part of ent->bh so just checking inum
3423 * and the name isn't enough.
3424 */
3425 if (le32_to_cpu(ent->de->inode) != ent->inode->i_ino ||
3426 ent->de->name_len != ent->dentry->d_name.len ||
3427 strncmp(ent->de->name, ent->dentry->d_name.name,
3428 ent->de->name_len) ||
3429 force_reread) {
3430 retval = ext4_find_delete_entry(handle, ent->dir,
3431 &ent->dentry->d_name);
3432 } else {
3433 retval = ext4_delete_entry(handle, ent->dir, ent->de, ent->bh);
3434 if (retval == -ENOENT) {
3435 retval = ext4_find_delete_entry(handle, ent->dir,
3436 &ent->dentry->d_name);
3437 }
3438 }
3439
3440 if (retval) {
3441 ext4_warning_inode(ent->dir,
3442 "Deleting old file: nlink %d, error=%d",
3443 ent->dir->i_nlink, retval);
3444 }
3445 }
3446
3447 static void ext4_update_dir_count(handle_t *handle, struct ext4_renament *ent)
3448 {
3449 if (ent->dir_nlink_delta) {
3450 if (ent->dir_nlink_delta == -1)
3451 ext4_dec_count(handle, ent->dir);
3452 else
3453 ext4_inc_count(handle, ent->dir);
3454 ext4_mark_inode_dirty(handle, ent->dir);
3455 }
3456 }
3457
3458 static struct inode *ext4_whiteout_for_rename(struct ext4_renament *ent,
3459 int credits, handle_t **h)
3460 {
3461 struct inode *wh;
3462 handle_t *handle;
3463 int retries = 0;
3464
3465 /*
3466 * for inode block, sb block, group summaries,
3467 * and inode bitmap
3468 */
3469 credits += (EXT4_MAXQUOTAS_TRANS_BLOCKS(ent->dir->i_sb) +
3470 EXT4_XATTR_TRANS_BLOCKS + 4);
3471 retry:
3472 wh = ext4_new_inode_start_handle(ent->dir, S_IFCHR | WHITEOUT_MODE,
3473 &ent->dentry->d_name, 0, NULL,
3474 EXT4_HT_DIR, credits);
3475
3476 handle = ext4_journal_current_handle();
3477 if (IS_ERR(wh)) {
3478 if (handle)
3479 ext4_journal_stop(handle);
3480 if (PTR_ERR(wh) == -ENOSPC &&
3481 ext4_should_retry_alloc(ent->dir->i_sb, &retries))
3482 goto retry;
3483 } else {
3484 *h = handle;
3485 init_special_inode(wh, wh->i_mode, WHITEOUT_DEV);
3486 wh->i_op = &ext4_special_inode_operations;
3487 }
3488 return wh;
3489 }
3490
3491 /*
3492 * Anybody can rename anything with this: the permission checks are left to the
3493 * higher-level routines.
3494 *
3495 * n.b. old_{dentry,inode) refers to the source dentry/inode
3496 * while new_{dentry,inode) refers to the destination dentry/inode
3497 * This comes from rename(const char *oldpath, const char *newpath)
3498 */
3499 static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
3500 struct inode *new_dir, struct dentry *new_dentry,
3501 unsigned int flags)
3502 {
3503 handle_t *handle = NULL;
3504 struct ext4_renament old = {
3505 .dir = old_dir,
3506 .dentry = old_dentry,
3507 .inode = d_inode(old_dentry),
3508 };
3509 struct ext4_renament new = {
3510 .dir = new_dir,
3511 .dentry = new_dentry,
3512 .inode = d_inode(new_dentry),
3513 };
3514 int force_reread;
3515 int retval;
3516 struct inode *whiteout = NULL;
3517 int credits;
3518 u8 old_file_type;
3519
3520 if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT)) &&
3521 (!projid_eq(EXT4_I(new_dir)->i_projid,
3522 EXT4_I(old_dentry->d_inode)->i_projid)))
3523 return -EXDEV;
3524
3525 retval = dquot_initialize(old.dir);
3526 if (retval)
3527 return retval;
3528 retval = dquot_initialize(new.dir);
3529 if (retval)
3530 return retval;
3531
3532 /* Initialize quotas before so that eventual writes go
3533 * in separate transaction */
3534 if (new.inode) {
3535 retval = dquot_initialize(new.inode);
3536 if (retval)
3537 return retval;
3538 }
3539
3540 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, NULL);
3541 if (IS_ERR(old.bh))
3542 return PTR_ERR(old.bh);
3543 /*
3544 * Check for inode number is _not_ due to possible IO errors.
3545 * We might rmdir the source, keep it as pwd of some process
3546 * and merrily kill the link to whatever was created under the
3547 * same name. Goodbye sticky bit ;-<
3548 */
3549 retval = -ENOENT;
3550 if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3551 goto end_rename;
3552
3553 if ((old.dir != new.dir) &&
3554 ext4_encrypted_inode(new.dir) &&
3555 !ext4_is_child_context_consistent_with_parent(new.dir,
3556 old.inode)) {
3557 retval = -EPERM;
3558 goto end_rename;
3559 }
3560
3561 new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
3562 &new.de, &new.inlined);
3563 if (IS_ERR(new.bh)) {
3564 retval = PTR_ERR(new.bh);
3565 new.bh = NULL;
3566 goto end_rename;
3567 }
3568 if (new.bh) {
3569 if (!new.inode) {
3570 brelse(new.bh);
3571 new.bh = NULL;
3572 }
3573 }
3574 if (new.inode && !test_opt(new.dir->i_sb, NO_AUTO_DA_ALLOC))
3575 ext4_alloc_da_blocks(old.inode);
3576
3577 credits = (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3578 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
3579 if (!(flags & RENAME_WHITEOUT)) {
3580 handle = ext4_journal_start(old.dir, EXT4_HT_DIR, credits);
3581 if (IS_ERR(handle)) {
3582 retval = PTR_ERR(handle);
3583 handle = NULL;
3584 goto end_rename;
3585 }
3586 } else {
3587 whiteout = ext4_whiteout_for_rename(&old, credits, &handle);
3588 if (IS_ERR(whiteout)) {
3589 retval = PTR_ERR(whiteout);
3590 whiteout = NULL;
3591 goto end_rename;
3592 }
3593 }
3594
3595 if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3596 ext4_handle_sync(handle);
3597
3598 if (S_ISDIR(old.inode->i_mode)) {
3599 if (new.inode) {
3600 retval = -ENOTEMPTY;
3601 if (!ext4_empty_dir(new.inode))
3602 goto end_rename;
3603 } else {
3604 retval = -EMLINK;
3605 if (new.dir != old.dir && EXT4_DIR_LINK_MAX(new.dir))
3606 goto end_rename;
3607 }
3608 retval = ext4_rename_dir_prepare(handle, &old);
3609 if (retval)
3610 goto end_rename;
3611 }
3612 /*
3613 * If we're renaming a file within an inline_data dir and adding or
3614 * setting the new dirent causes a conversion from inline_data to
3615 * extents/blockmap, we need to force the dirent delete code to
3616 * re-read the directory, or else we end up trying to delete a dirent
3617 * from what is now the extent tree root (or a block map).
3618 */
3619 force_reread = (new.dir->i_ino == old.dir->i_ino &&
3620 ext4_test_inode_flag(new.dir, EXT4_INODE_INLINE_DATA));
3621
3622 old_file_type = old.de->file_type;
3623 if (whiteout) {
3624 /*
3625 * Do this before adding a new entry, so the old entry is sure
3626 * to be still pointing to the valid old entry.
3627 */
3628 retval = ext4_setent(handle, &old, whiteout->i_ino,
3629 EXT4_FT_CHRDEV);
3630 if (retval)
3631 goto end_rename;
3632 ext4_mark_inode_dirty(handle, whiteout);
3633 }
3634 if (!new.bh) {
3635 retval = ext4_add_entry(handle, new.dentry, old.inode);
3636 if (retval)
3637 goto end_rename;
3638 } else {
3639 retval = ext4_setent(handle, &new,
3640 old.inode->i_ino, old_file_type);
3641 if (retval)
3642 goto end_rename;
3643 }
3644 if (force_reread)
3645 force_reread = !ext4_test_inode_flag(new.dir,
3646 EXT4_INODE_INLINE_DATA);
3647
3648 /*
3649 * Like most other Unix systems, set the ctime for inodes on a
3650 * rename.
3651 */
3652 old.inode->i_ctime = ext4_current_time(old.inode);
3653 ext4_mark_inode_dirty(handle, old.inode);
3654
3655 if (!whiteout) {
3656 /*
3657 * ok, that's it
3658 */
3659 ext4_rename_delete(handle, &old, force_reread);
3660 }
3661
3662 if (new.inode) {
3663 ext4_dec_count(handle, new.inode);
3664 new.inode->i_ctime = ext4_current_time(new.inode);
3665 }
3666 old.dir->i_ctime = old.dir->i_mtime = ext4_current_time(old.dir);
3667 ext4_update_dx_flag(old.dir);
3668 if (old.dir_bh) {
3669 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
3670 if (retval)
3671 goto end_rename;
3672
3673 ext4_dec_count(handle, old.dir);
3674 if (new.inode) {
3675 /* checked ext4_empty_dir above, can't have another
3676 * parent, ext4_dec_count() won't work for many-linked
3677 * dirs */
3678 clear_nlink(new.inode);
3679 } else {
3680 ext4_inc_count(handle, new.dir);
3681 ext4_update_dx_flag(new.dir);
3682 ext4_mark_inode_dirty(handle, new.dir);
3683 }
3684 }
3685 ext4_mark_inode_dirty(handle, old.dir);
3686 if (new.inode) {
3687 ext4_mark_inode_dirty(handle, new.inode);
3688 if (!new.inode->i_nlink)
3689 ext4_orphan_add(handle, new.inode);
3690 }
3691 retval = 0;
3692
3693 end_rename:
3694 brelse(old.dir_bh);
3695 brelse(old.bh);
3696 brelse(new.bh);
3697 if (whiteout) {
3698 if (retval)
3699 drop_nlink(whiteout);
3700 unlock_new_inode(whiteout);
3701 iput(whiteout);
3702 }
3703 if (handle)
3704 ext4_journal_stop(handle);
3705 return retval;
3706 }
3707
3708 static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
3709 struct inode *new_dir, struct dentry *new_dentry)
3710 {
3711 handle_t *handle = NULL;
3712 struct ext4_renament old = {
3713 .dir = old_dir,
3714 .dentry = old_dentry,
3715 .inode = d_inode(old_dentry),
3716 };
3717 struct ext4_renament new = {
3718 .dir = new_dir,
3719 .dentry = new_dentry,
3720 .inode = d_inode(new_dentry),
3721 };
3722 u8 new_file_type;
3723 int retval;
3724
3725 if ((ext4_encrypted_inode(old_dir) ||
3726 ext4_encrypted_inode(new_dir)) &&
3727 (old_dir != new_dir) &&
3728 (!ext4_is_child_context_consistent_with_parent(new_dir,
3729 old.inode) ||
3730 !ext4_is_child_context_consistent_with_parent(old_dir,
3731 new.inode)))
3732 return -EPERM;
3733
3734 if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT) &&
3735 !projid_eq(EXT4_I(new_dir)->i_projid,
3736 EXT4_I(old_dentry->d_inode)->i_projid)) ||
3737 (ext4_test_inode_flag(old_dir, EXT4_INODE_PROJINHERIT) &&
3738 !projid_eq(EXT4_I(old_dir)->i_projid,
3739 EXT4_I(new_dentry->d_inode)->i_projid)))
3740 return -EXDEV;
3741
3742 retval = dquot_initialize(old.dir);
3743 if (retval)
3744 return retval;
3745 retval = dquot_initialize(new.dir);
3746 if (retval)
3747 return retval;
3748
3749 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name,
3750 &old.de, &old.inlined);
3751 if (IS_ERR(old.bh))
3752 return PTR_ERR(old.bh);
3753 /*
3754 * Check for inode number is _not_ due to possible IO errors.
3755 * We might rmdir the source, keep it as pwd of some process
3756 * and merrily kill the link to whatever was created under the
3757 * same name. Goodbye sticky bit ;-<
3758 */
3759 retval = -ENOENT;
3760 if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3761 goto end_rename;
3762
3763 new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
3764 &new.de, &new.inlined);
3765 if (IS_ERR(new.bh)) {
3766 retval = PTR_ERR(new.bh);
3767 new.bh = NULL;
3768 goto end_rename;
3769 }
3770
3771 /* RENAME_EXCHANGE case: old *and* new must both exist */
3772 if (!new.bh || le32_to_cpu(new.de->inode) != new.inode->i_ino)
3773 goto end_rename;
3774
3775 handle = ext4_journal_start(old.dir, EXT4_HT_DIR,
3776 (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3777 2 * EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2));
3778 if (IS_ERR(handle)) {
3779 retval = PTR_ERR(handle);
3780 handle = NULL;
3781 goto end_rename;
3782 }
3783
3784 if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3785 ext4_handle_sync(handle);
3786
3787 if (S_ISDIR(old.inode->i_mode)) {
3788 old.is_dir = true;
3789 retval = ext4_rename_dir_prepare(handle, &old);
3790 if (retval)
3791 goto end_rename;
3792 }
3793 if (S_ISDIR(new.inode->i_mode)) {
3794 new.is_dir = true;
3795 retval = ext4_rename_dir_prepare(handle, &new);
3796 if (retval)
3797 goto end_rename;
3798 }
3799
3800 /*
3801 * Other than the special case of overwriting a directory, parents'
3802 * nlink only needs to be modified if this is a cross directory rename.
3803 */
3804 if (old.dir != new.dir && old.is_dir != new.is_dir) {
3805 old.dir_nlink_delta = old.is_dir ? -1 : 1;
3806 new.dir_nlink_delta = -old.dir_nlink_delta;
3807 retval = -EMLINK;
3808 if ((old.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(old.dir)) ||
3809 (new.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(new.dir)))
3810 goto end_rename;
3811 }
3812
3813 new_file_type = new.de->file_type;
3814 retval = ext4_setent(handle, &new, old.inode->i_ino, old.de->file_type);
3815 if (retval)
3816 goto end_rename;
3817
3818 retval = ext4_setent(handle, &old, new.inode->i_ino, new_file_type);
3819 if (retval)
3820 goto end_rename;
3821
3822 /*
3823 * Like most other Unix systems, set the ctime for inodes on a
3824 * rename.
3825 */
3826 old.inode->i_ctime = ext4_current_time(old.inode);
3827 new.inode->i_ctime = ext4_current_time(new.inode);
3828 ext4_mark_inode_dirty(handle, old.inode);
3829 ext4_mark_inode_dirty(handle, new.inode);
3830
3831 if (old.dir_bh) {
3832 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
3833 if (retval)
3834 goto end_rename;
3835 }
3836 if (new.dir_bh) {
3837 retval = ext4_rename_dir_finish(handle, &new, old.dir->i_ino);
3838 if (retval)
3839 goto end_rename;
3840 }
3841 ext4_update_dir_count(handle, &old);
3842 ext4_update_dir_count(handle, &new);
3843 retval = 0;
3844
3845 end_rename:
3846 brelse(old.dir_bh);
3847 brelse(new.dir_bh);
3848 brelse(old.bh);
3849 brelse(new.bh);
3850 if (handle)
3851 ext4_journal_stop(handle);
3852 return retval;
3853 }
3854
3855 static int ext4_rename2(struct inode *old_dir, struct dentry *old_dentry,
3856 struct inode *new_dir, struct dentry *new_dentry,
3857 unsigned int flags)
3858 {
3859 if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
3860 return -EINVAL;
3861
3862 if (flags & RENAME_EXCHANGE) {
3863 return ext4_cross_rename(old_dir, old_dentry,
3864 new_dir, new_dentry);
3865 }
3866
3867 return ext4_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
3868 }
3869
3870 /*
3871 * directories can handle most operations...
3872 */
3873 const struct inode_operations ext4_dir_inode_operations = {
3874 .create = ext4_create,
3875 .lookup = ext4_lookup,
3876 .link = ext4_link,
3877 .unlink = ext4_unlink,
3878 .symlink = ext4_symlink,
3879 .mkdir = ext4_mkdir,
3880 .rmdir = ext4_rmdir,
3881 .mknod = ext4_mknod,
3882 .tmpfile = ext4_tmpfile,
3883 .rename2 = ext4_rename2,
3884 .setattr = ext4_setattr,
3885 .setxattr = generic_setxattr,
3886 .getxattr = generic_getxattr,
3887 .listxattr = ext4_listxattr,
3888 .removexattr = generic_removexattr,
3889 .get_acl = ext4_get_acl,
3890 .set_acl = ext4_set_acl,
3891 .fiemap = ext4_fiemap,
3892 };
3893
3894 const struct inode_operations ext4_special_inode_operations = {
3895 .setattr = ext4_setattr,
3896 .setxattr = generic_setxattr,
3897 .getxattr = generic_getxattr,
3898 .listxattr = ext4_listxattr,
3899 .removexattr = generic_removexattr,
3900 .get_acl = ext4_get_acl,
3901 .set_acl = ext4_set_acl,
3902 };
Linux with added FPC-III support