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Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
[deliverable/linux.git] / fs / ext4 / namei.c
1 /*
2 * linux/fs/ext4/namei.c
3 *
4 * Copyright (C) 1992, 1993, 1994, 1995
5 * Remy Card (card@masi.ibp.fr)
6 * Laboratoire MASI - Institut Blaise Pascal
7 * Universite Pierre et Marie Curie (Paris VI)
8 *
9 * from
10 *
11 * linux/fs/minix/namei.c
12 *
13 * Copyright (C) 1991, 1992 Linus Torvalds
14 *
15 * Big-endian to little-endian byte-swapping/bitmaps by
16 * David S. Miller (davem@caip.rutgers.edu), 1995
17 * Directory entry file type support and forward compatibility hooks
18 * for B-tree directories by Theodore Ts'o (tytso@mit.edu), 1998
19 * Hash Tree Directory indexing (c)
20 * Daniel Phillips, 2001
21 * Hash Tree Directory indexing porting
22 * Christopher Li, 2002
23 * Hash Tree Directory indexing cleanup
24 * Theodore Ts'o, 2002
25 */
26
27 #include <linux/fs.h>
28 #include <linux/pagemap.h>
29 #include <linux/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, 1);
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), __LINE__)
88
89 static struct buffer_head *__ext4_read_dirblock(struct inode *inode,
90 ext4_lblk_t block,
91 dirblock_type_t type,
92 unsigned int line)
93 {
94 struct buffer_head *bh;
95 struct ext4_dir_entry *dirent;
96 int is_dx_block = 0;
97
98 bh = ext4_bread(NULL, inode, block, 0);
99 if (IS_ERR(bh)) {
100 __ext4_warning(inode->i_sb, __func__, line,
101 "error %ld reading directory block "
102 "(ino %lu, block %lu)", PTR_ERR(bh), inode->i_ino,
103 (unsigned long) block);
104
105 return bh;
106 }
107 if (!bh) {
108 ext4_error_inode(inode, __func__, line, block, "Directory hole found");
109 return ERR_PTR(-EIO);
110 }
111 dirent = (struct ext4_dir_entry *) bh->b_data;
112 /* Determine whether or not we have an index block */
113 if (is_dx(inode)) {
114 if (block == 0)
115 is_dx_block = 1;
116 else if (ext4_rec_len_from_disk(dirent->rec_len,
117 inode->i_sb->s_blocksize) ==
118 inode->i_sb->s_blocksize)
119 is_dx_block = 1;
120 }
121 if (!is_dx_block && type == INDEX) {
122 ext4_error_inode(inode, __func__, line, block,
123 "directory leaf block found instead of index block");
124 return ERR_PTR(-EIO);
125 }
126 if (!ext4_has_metadata_csum(inode->i_sb) ||
127 buffer_verified(bh))
128 return bh;
129
130 /*
131 * An empty leaf block can get mistaken for a index block; for
132 * this reason, we can only check the index checksum when the
133 * caller is sure it should be an index block.
134 */
135 if (is_dx_block && type == INDEX) {
136 if (ext4_dx_csum_verify(inode, dirent))
137 set_buffer_verified(bh);
138 else {
139 ext4_error_inode(inode, __func__, line, block,
140 "Directory index failed checksum");
141 brelse(bh);
142 return ERR_PTR(-EIO);
143 }
144 }
145 if (!is_dx_block) {
146 if (ext4_dirent_csum_verify(inode, dirent))
147 set_buffer_verified(bh);
148 else {
149 ext4_error_inode(inode, __func__, line, block,
150 "Directory block failed checksum");
151 brelse(bh);
152 return ERR_PTR(-EIO);
153 }
154 }
155 return bh;
156 }
157
158 #ifndef assert
159 #define assert(test) J_ASSERT(test)
160 #endif
161
162 #ifdef DX_DEBUG
163 #define dxtrace(command) command
164 #else
165 #define dxtrace(command)
166 #endif
167
168 struct fake_dirent
169 {
170 __le32 inode;
171 __le16 rec_len;
172 u8 name_len;
173 u8 file_type;
174 };
175
176 struct dx_countlimit
177 {
178 __le16 limit;
179 __le16 count;
180 };
181
182 struct dx_entry
183 {
184 __le32 hash;
185 __le32 block;
186 };
187
188 /*
189 * dx_root_info is laid out so that if it should somehow get overlaid by a
190 * dirent the two low bits of the hash version will be zero. Therefore, the
191 * hash version mod 4 should never be 0. Sincerely, the paranoia department.
192 */
193
194 struct dx_root
195 {
196 struct fake_dirent dot;
197 char dot_name[4];
198 struct fake_dirent dotdot;
199 char dotdot_name[4];
200 struct dx_root_info
201 {
202 __le32 reserved_zero;
203 u8 hash_version;
204 u8 info_length; /* 8 */
205 u8 indirect_levels;
206 u8 unused_flags;
207 }
208 info;
209 struct dx_entry entries[0];
210 };
211
212 struct dx_node
213 {
214 struct fake_dirent fake;
215 struct dx_entry entries[0];
216 };
217
218
219 struct dx_frame
220 {
221 struct buffer_head *bh;
222 struct dx_entry *entries;
223 struct dx_entry *at;
224 };
225
226 struct dx_map_entry
227 {
228 u32 hash;
229 u16 offs;
230 u16 size;
231 };
232
233 /*
234 * This goes at the end of each htree block.
235 */
236 struct dx_tail {
237 u32 dt_reserved;
238 __le32 dt_checksum; /* crc32c(uuid+inum+dirblock) */
239 };
240
241 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
242 static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
243 static inline unsigned dx_get_hash(struct dx_entry *entry);
244 static void dx_set_hash(struct dx_entry *entry, unsigned value);
245 static unsigned dx_get_count(struct dx_entry *entries);
246 static unsigned dx_get_limit(struct dx_entry *entries);
247 static void dx_set_count(struct dx_entry *entries, unsigned value);
248 static void dx_set_limit(struct dx_entry *entries, unsigned value);
249 static unsigned dx_root_limit(struct inode *dir, unsigned infosize);
250 static unsigned dx_node_limit(struct inode *dir);
251 static struct dx_frame *dx_probe(const struct qstr *d_name,
252 struct inode *dir,
253 struct dx_hash_info *hinfo,
254 struct dx_frame *frame);
255 static void dx_release(struct dx_frame *frames);
256 static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de,
257 unsigned blocksize, struct dx_hash_info *hinfo,
258 struct dx_map_entry map[]);
259 static void dx_sort_map(struct dx_map_entry *map, unsigned count);
260 static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to,
261 struct dx_map_entry *offsets, int count, unsigned blocksize);
262 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize);
263 static void dx_insert_block(struct dx_frame *frame,
264 u32 hash, ext4_lblk_t block);
265 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
266 struct dx_frame *frame,
267 struct dx_frame *frames,
268 __u32 *start_hash);
269 static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
270 const struct qstr *d_name,
271 struct ext4_dir_entry_2 **res_dir);
272 static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
273 struct inode *inode);
274
275 /* checksumming functions */
276 void initialize_dirent_tail(struct ext4_dir_entry_tail *t,
277 unsigned int blocksize)
278 {
279 memset(t, 0, sizeof(struct ext4_dir_entry_tail));
280 t->det_rec_len = ext4_rec_len_to_disk(
281 sizeof(struct ext4_dir_entry_tail), blocksize);
282 t->det_reserved_ft = EXT4_FT_DIR_CSUM;
283 }
284
285 /* Walk through a dirent block to find a checksum "dirent" at the tail */
286 static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode,
287 struct ext4_dir_entry *de)
288 {
289 struct ext4_dir_entry_tail *t;
290
291 #ifdef PARANOID
292 struct ext4_dir_entry *d, *top;
293
294 d = de;
295 top = (struct ext4_dir_entry *)(((void *)de) +
296 (EXT4_BLOCK_SIZE(inode->i_sb) -
297 sizeof(struct ext4_dir_entry_tail)));
298 while (d < top && d->rec_len)
299 d = (struct ext4_dir_entry *)(((void *)d) +
300 le16_to_cpu(d->rec_len));
301
302 if (d != top)
303 return NULL;
304
305 t = (struct ext4_dir_entry_tail *)d;
306 #else
307 t = EXT4_DIRENT_TAIL(de, EXT4_BLOCK_SIZE(inode->i_sb));
308 #endif
309
310 if (t->det_reserved_zero1 ||
311 le16_to_cpu(t->det_rec_len) != sizeof(struct ext4_dir_entry_tail) ||
312 t->det_reserved_zero2 ||
313 t->det_reserved_ft != EXT4_FT_DIR_CSUM)
314 return NULL;
315
316 return t;
317 }
318
319 static __le32 ext4_dirent_csum(struct inode *inode,
320 struct ext4_dir_entry *dirent, int size)
321 {
322 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
323 struct ext4_inode_info *ei = EXT4_I(inode);
324 __u32 csum;
325
326 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
327 return cpu_to_le32(csum);
328 }
329
330 static void warn_no_space_for_csum(struct inode *inode)
331 {
332 ext4_warning(inode->i_sb, "no space in directory inode %lu leaf for "
333 "checksum. Please run e2fsck -D.", inode->i_ino);
334 }
335
336 int ext4_dirent_csum_verify(struct inode *inode, struct ext4_dir_entry *dirent)
337 {
338 struct ext4_dir_entry_tail *t;
339
340 if (!ext4_has_metadata_csum(inode->i_sb))
341 return 1;
342
343 t = get_dirent_tail(inode, dirent);
344 if (!t) {
345 warn_no_space_for_csum(inode);
346 return 0;
347 }
348
349 if (t->det_checksum != ext4_dirent_csum(inode, dirent,
350 (void *)t - (void *)dirent))
351 return 0;
352
353 return 1;
354 }
355
356 static void ext4_dirent_csum_set(struct inode *inode,
357 struct ext4_dir_entry *dirent)
358 {
359 struct ext4_dir_entry_tail *t;
360
361 if (!ext4_has_metadata_csum(inode->i_sb))
362 return;
363
364 t = get_dirent_tail(inode, dirent);
365 if (!t) {
366 warn_no_space_for_csum(inode);
367 return;
368 }
369
370 t->det_checksum = ext4_dirent_csum(inode, dirent,
371 (void *)t - (void *)dirent);
372 }
373
374 int ext4_handle_dirty_dirent_node(handle_t *handle,
375 struct inode *inode,
376 struct buffer_head *bh)
377 {
378 ext4_dirent_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
379 return ext4_handle_dirty_metadata(handle, inode, bh);
380 }
381
382 static struct dx_countlimit *get_dx_countlimit(struct inode *inode,
383 struct ext4_dir_entry *dirent,
384 int *offset)
385 {
386 struct ext4_dir_entry *dp;
387 struct dx_root_info *root;
388 int count_offset;
389
390 if (le16_to_cpu(dirent->rec_len) == EXT4_BLOCK_SIZE(inode->i_sb))
391 count_offset = 8;
392 else if (le16_to_cpu(dirent->rec_len) == 12) {
393 dp = (struct ext4_dir_entry *)(((void *)dirent) + 12);
394 if (le16_to_cpu(dp->rec_len) !=
395 EXT4_BLOCK_SIZE(inode->i_sb) - 12)
396 return NULL;
397 root = (struct dx_root_info *)(((void *)dp + 12));
398 if (root->reserved_zero ||
399 root->info_length != sizeof(struct dx_root_info))
400 return NULL;
401 count_offset = 32;
402 } else
403 return NULL;
404
405 if (offset)
406 *offset = count_offset;
407 return (struct dx_countlimit *)(((void *)dirent) + count_offset);
408 }
409
410 static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent,
411 int count_offset, int count, struct dx_tail *t)
412 {
413 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
414 struct ext4_inode_info *ei = EXT4_I(inode);
415 __u32 csum;
416 __le32 save_csum;
417 int size;
418
419 size = count_offset + (count * sizeof(struct dx_entry));
420 save_csum = t->dt_checksum;
421 t->dt_checksum = 0;
422 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
423 csum = ext4_chksum(sbi, csum, (__u8 *)t, sizeof(struct dx_tail));
424 t->dt_checksum = save_csum;
425
426 return cpu_to_le32(csum);
427 }
428
429 static int ext4_dx_csum_verify(struct inode *inode,
430 struct ext4_dir_entry *dirent)
431 {
432 struct dx_countlimit *c;
433 struct dx_tail *t;
434 int count_offset, limit, count;
435
436 if (!ext4_has_metadata_csum(inode->i_sb))
437 return 1;
438
439 c = get_dx_countlimit(inode, dirent, &count_offset);
440 if (!c) {
441 EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D.");
442 return 1;
443 }
444 limit = le16_to_cpu(c->limit);
445 count = le16_to_cpu(c->count);
446 if (count_offset + (limit * sizeof(struct dx_entry)) >
447 EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
448 warn_no_space_for_csum(inode);
449 return 1;
450 }
451 t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
452
453 if (t->dt_checksum != ext4_dx_csum(inode, dirent, count_offset,
454 count, t))
455 return 0;
456 return 1;
457 }
458
459 static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent)
460 {
461 struct dx_countlimit *c;
462 struct dx_tail *t;
463 int count_offset, limit, count;
464
465 if (!ext4_has_metadata_csum(inode->i_sb))
466 return;
467
468 c = get_dx_countlimit(inode, dirent, &count_offset);
469 if (!c) {
470 EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D.");
471 return;
472 }
473 limit = le16_to_cpu(c->limit);
474 count = le16_to_cpu(c->count);
475 if (count_offset + (limit * sizeof(struct dx_entry)) >
476 EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
477 warn_no_space_for_csum(inode);
478 return;
479 }
480 t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
481
482 t->dt_checksum = ext4_dx_csum(inode, dirent, count_offset, count, t);
483 }
484
485 static inline int ext4_handle_dirty_dx_node(handle_t *handle,
486 struct inode *inode,
487 struct buffer_head *bh)
488 {
489 ext4_dx_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
490 return ext4_handle_dirty_metadata(handle, inode, bh);
491 }
492
493 /*
494 * p is at least 6 bytes before the end of page
495 */
496 static inline struct ext4_dir_entry_2 *
497 ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
498 {
499 return (struct ext4_dir_entry_2 *)((char *)p +
500 ext4_rec_len_from_disk(p->rec_len, blocksize));
501 }
502
503 /*
504 * Future: use high four bits of block for coalesce-on-delete flags
505 * Mask them off for now.
506 */
507
508 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
509 {
510 return le32_to_cpu(entry->block) & 0x00ffffff;
511 }
512
513 static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
514 {
515 entry->block = cpu_to_le32(value);
516 }
517
518 static inline unsigned dx_get_hash(struct dx_entry *entry)
519 {
520 return le32_to_cpu(entry->hash);
521 }
522
523 static inline void dx_set_hash(struct dx_entry *entry, unsigned value)
524 {
525 entry->hash = cpu_to_le32(value);
526 }
527
528 static inline unsigned dx_get_count(struct dx_entry *entries)
529 {
530 return le16_to_cpu(((struct dx_countlimit *) entries)->count);
531 }
532
533 static inline unsigned dx_get_limit(struct dx_entry *entries)
534 {
535 return le16_to_cpu(((struct dx_countlimit *) entries)->limit);
536 }
537
538 static inline void dx_set_count(struct dx_entry *entries, unsigned value)
539 {
540 ((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
541 }
542
543 static inline void dx_set_limit(struct dx_entry *entries, unsigned value)
544 {
545 ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
546 }
547
548 static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
549 {
550 unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
551 EXT4_DIR_REC_LEN(2) - infosize;
552
553 if (ext4_has_metadata_csum(dir->i_sb))
554 entry_space -= sizeof(struct dx_tail);
555 return entry_space / sizeof(struct dx_entry);
556 }
557
558 static inline unsigned dx_node_limit(struct inode *dir)
559 {
560 unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);
561
562 if (ext4_has_metadata_csum(dir->i_sb))
563 entry_space -= sizeof(struct dx_tail);
564 return entry_space / sizeof(struct dx_entry);
565 }
566
567 /*
568 * Debug
569 */
570 #ifdef DX_DEBUG
571 static void dx_show_index(char * label, struct dx_entry *entries)
572 {
573 int i, n = dx_get_count (entries);
574 printk(KERN_DEBUG "%s index ", label);
575 for (i = 0; i < n; i++) {
576 printk("%x->%lu ", i ? dx_get_hash(entries + i) :
577 0, (unsigned long)dx_get_block(entries + i));
578 }
579 printk("\n");
580 }
581
582 struct stats
583 {
584 unsigned names;
585 unsigned space;
586 unsigned bcount;
587 };
588
589 static struct stats dx_show_leaf(struct inode *dir,
590 struct dx_hash_info *hinfo,
591 struct ext4_dir_entry_2 *de,
592 int size, int show_names)
593 {
594 unsigned names = 0, space = 0;
595 char *base = (char *) de;
596 struct dx_hash_info h = *hinfo;
597
598 printk("names: ");
599 while ((char *) de < base + size)
600 {
601 if (de->inode)
602 {
603 if (show_names)
604 {
605 #ifdef CONFIG_EXT4_FS_ENCRYPTION
606 int len;
607 char *name;
608 struct ext4_str fname_crypto_str
609 = {.name = NULL, .len = 0};
610 struct ext4_fname_crypto_ctx *ctx = NULL;
611 int res;
612
613 name = de->name;
614 len = de->name_len;
615 ctx = ext4_get_fname_crypto_ctx(dir,
616 EXT4_NAME_LEN);
617 if (IS_ERR(ctx)) {
618 printk(KERN_WARNING "Error acquiring"
619 " crypto ctxt--skipping crypto\n");
620 ctx = NULL;
621 }
622 if (ctx == NULL) {
623 /* Directory is not encrypted */
624 ext4fs_dirhash(de->name,
625 de->name_len, &h);
626 printk("%*.s:(U)%x.%u ", len,
627 name, h.hash,
628 (unsigned) ((char *) de
629 - base));
630 } else {
631 /* Directory is encrypted */
632 res = ext4_fname_crypto_alloc_buffer(
633 ctx, de->name_len,
634 &fname_crypto_str);
635 if (res < 0) {
636 printk(KERN_WARNING "Error "
637 "allocating crypto "
638 "buffer--skipping "
639 "crypto\n");
640 ext4_put_fname_crypto_ctx(&ctx);
641 ctx = NULL;
642 }
643 res = ext4_fname_disk_to_usr(ctx, de,
644 &fname_crypto_str);
645 if (res < 0) {
646 printk(KERN_WARNING "Error "
647 "converting filename "
648 "from disk to usr"
649 "\n");
650 name = "??";
651 len = 2;
652 } else {
653 name = fname_crypto_str.name;
654 len = fname_crypto_str.len;
655 }
656 res = ext4_fname_disk_to_hash(ctx, de,
657 &h);
658 if (res < 0) {
659 printk(KERN_WARNING "Error "
660 "converting filename "
661 "from disk to htree"
662 "\n");
663 h.hash = 0xDEADBEEF;
664 }
665 printk("%*.s:(E)%x.%u ", len, name,
666 h.hash, (unsigned) ((char *) de
667 - base));
668 ext4_put_fname_crypto_ctx(&ctx);
669 ext4_fname_crypto_free_buffer(
670 &fname_crypto_str);
671 }
672 #else
673 int len = de->name_len;
674 char *name = de->name;
675 ext4fs_dirhash(de->name, de->name_len, &h);
676 printk("%*.s:%x.%u ", len, name, h.hash,
677 (unsigned) ((char *) de - base));
678 #endif
679 }
680 space += EXT4_DIR_REC_LEN(de->name_len);
681 names++;
682 }
683 de = ext4_next_entry(de, size);
684 }
685 printk("(%i)\n", names);
686 return (struct stats) { names, space, 1 };
687 }
688
689 struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
690 struct dx_entry *entries, int levels)
691 {
692 unsigned blocksize = dir->i_sb->s_blocksize;
693 unsigned count = dx_get_count(entries), names = 0, space = 0, i;
694 unsigned bcount = 0;
695 struct buffer_head *bh;
696 printk("%i indexed blocks...\n", count);
697 for (i = 0; i < count; i++, entries++)
698 {
699 ext4_lblk_t block = dx_get_block(entries);
700 ext4_lblk_t hash = i ? dx_get_hash(entries): 0;
701 u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
702 struct stats stats;
703 printk("%s%3u:%03u hash %8x/%8x ",levels?"":" ", i, block, hash, range);
704 bh = ext4_bread(NULL,dir, block, 0);
705 if (!bh || IS_ERR(bh))
706 continue;
707 stats = levels?
708 dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
709 dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *)
710 bh->b_data, blocksize, 0);
711 names += stats.names;
712 space += stats.space;
713 bcount += stats.bcount;
714 brelse(bh);
715 }
716 if (bcount)
717 printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n",
718 levels ? "" : " ", names, space/bcount,
719 (space/bcount)*100/blocksize);
720 return (struct stats) { names, space, bcount};
721 }
722 #endif /* DX_DEBUG */
723
724 /*
725 * Probe for a directory leaf block to search.
726 *
727 * dx_probe can return ERR_BAD_DX_DIR, which means there was a format
728 * error in the directory index, and the caller should fall back to
729 * searching the directory normally. The callers of dx_probe **MUST**
730 * check for this error code, and make sure it never gets reflected
731 * back to userspace.
732 */
733 static struct dx_frame *
734 dx_probe(const struct qstr *d_name, struct inode *dir,
735 struct dx_hash_info *hinfo, struct dx_frame *frame_in)
736 {
737 unsigned count, indirect;
738 struct dx_entry *at, *entries, *p, *q, *m;
739 struct dx_root *root;
740 struct dx_frame *frame = frame_in;
741 struct dx_frame *ret_err = ERR_PTR(ERR_BAD_DX_DIR);
742 u32 hash;
743
744 frame->bh = ext4_read_dirblock(dir, 0, INDEX);
745 if (IS_ERR(frame->bh))
746 return (struct dx_frame *) frame->bh;
747
748 root = (struct dx_root *) frame->bh->b_data;
749 if (root->info.hash_version != DX_HASH_TEA &&
750 root->info.hash_version != DX_HASH_HALF_MD4 &&
751 root->info.hash_version != DX_HASH_LEGACY) {
752 ext4_warning(dir->i_sb, "Unrecognised inode hash code %d",
753 root->info.hash_version);
754 goto fail;
755 }
756 hinfo->hash_version = root->info.hash_version;
757 if (hinfo->hash_version <= DX_HASH_TEA)
758 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
759 hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
760 #ifdef CONFIG_EXT4_FS_ENCRYPTION
761 if (d_name) {
762 struct ext4_fname_crypto_ctx *ctx = NULL;
763 int res;
764
765 /* Check if the directory is encrypted */
766 ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN);
767 if (IS_ERR(ctx)) {
768 ret_err = ERR_PTR(PTR_ERR(ctx));
769 goto fail;
770 }
771 res = ext4_fname_usr_to_hash(ctx, d_name, hinfo);
772 if (res < 0) {
773 ret_err = ERR_PTR(res);
774 goto fail;
775 }
776 ext4_put_fname_crypto_ctx(&ctx);
777 }
778 #else
779 if (d_name)
780 ext4fs_dirhash(d_name->name, d_name->len, hinfo);
781 #endif
782 hash = hinfo->hash;
783
784 if (root->info.unused_flags & 1) {
785 ext4_warning(dir->i_sb, "Unimplemented inode hash flags: %#06x",
786 root->info.unused_flags);
787 goto fail;
788 }
789
790 if ((indirect = root->info.indirect_levels) > 1) {
791 ext4_warning(dir->i_sb, "Unimplemented inode hash depth: %#06x",
792 root->info.indirect_levels);
793 goto fail;
794 }
795
796 entries = (struct dx_entry *) (((char *)&root->info) +
797 root->info.info_length);
798
799 if (dx_get_limit(entries) != dx_root_limit(dir,
800 root->info.info_length)) {
801 ext4_warning(dir->i_sb, "dx entry: limit != root limit");
802 goto fail;
803 }
804
805 dxtrace(printk("Look up %x", hash));
806 while (1) {
807 count = dx_get_count(entries);
808 if (!count || count > dx_get_limit(entries)) {
809 ext4_warning(dir->i_sb,
810 "dx entry: no count or count > limit");
811 goto fail;
812 }
813
814 p = entries + 1;
815 q = entries + count - 1;
816 while (p <= q) {
817 m = p + (q - p)/2;
818 dxtrace(printk("."));
819 if (dx_get_hash(m) > hash)
820 q = m - 1;
821 else
822 p = m + 1;
823 }
824
825 if (0) { // linear search cross check
826 unsigned n = count - 1;
827 at = entries;
828 while (n--)
829 {
830 dxtrace(printk(","));
831 if (dx_get_hash(++at) > hash)
832 {
833 at--;
834 break;
835 }
836 }
837 assert (at == p - 1);
838 }
839
840 at = p - 1;
841 dxtrace(printk(" %x->%u\n", at == entries? 0: dx_get_hash(at), dx_get_block(at)));
842 frame->entries = entries;
843 frame->at = at;
844 if (!indirect--)
845 return frame;
846 frame++;
847 frame->bh = ext4_read_dirblock(dir, dx_get_block(at), INDEX);
848 if (IS_ERR(frame->bh)) {
849 ret_err = (struct dx_frame *) frame->bh;
850 frame->bh = NULL;
851 goto fail;
852 }
853 entries = ((struct dx_node *) frame->bh->b_data)->entries;
854
855 if (dx_get_limit(entries) != dx_node_limit (dir)) {
856 ext4_warning(dir->i_sb,
857 "dx entry: limit != node limit");
858 goto fail;
859 }
860 }
861 fail:
862 while (frame >= frame_in) {
863 brelse(frame->bh);
864 frame--;
865 }
866
867 if (ret_err == ERR_PTR(ERR_BAD_DX_DIR))
868 ext4_warning(dir->i_sb,
869 "Corrupt dir inode %lu, running e2fsck is "
870 "recommended.", dir->i_ino);
871 return ret_err;
872 }
873
874 static void dx_release (struct dx_frame *frames)
875 {
876 if (frames[0].bh == NULL)
877 return;
878
879 if (((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels)
880 brelse(frames[1].bh);
881 brelse(frames[0].bh);
882 }
883
884 /*
885 * This function increments the frame pointer to search the next leaf
886 * block, and reads in the necessary intervening nodes if the search
887 * should be necessary. Whether or not the search is necessary is
888 * controlled by the hash parameter. If the hash value is even, then
889 * the search is only continued if the next block starts with that
890 * hash value. This is used if we are searching for a specific file.
891 *
892 * If the hash value is HASH_NB_ALWAYS, then always go to the next block.
893 *
894 * This function returns 1 if the caller should continue to search,
895 * or 0 if it should not. If there is an error reading one of the
896 * index blocks, it will a negative error code.
897 *
898 * If start_hash is non-null, it will be filled in with the starting
899 * hash of the next page.
900 */
901 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
902 struct dx_frame *frame,
903 struct dx_frame *frames,
904 __u32 *start_hash)
905 {
906 struct dx_frame *p;
907 struct buffer_head *bh;
908 int num_frames = 0;
909 __u32 bhash;
910
911 p = frame;
912 /*
913 * Find the next leaf page by incrementing the frame pointer.
914 * If we run out of entries in the interior node, loop around and
915 * increment pointer in the parent node. When we break out of
916 * this loop, num_frames indicates the number of interior
917 * nodes need to be read.
918 */
919 while (1) {
920 if (++(p->at) < p->entries + dx_get_count(p->entries))
921 break;
922 if (p == frames)
923 return 0;
924 num_frames++;
925 p--;
926 }
927
928 /*
929 * If the hash is 1, then continue only if the next page has a
930 * continuation hash of any value. This is used for readdir
931 * handling. Otherwise, check to see if the hash matches the
932 * desired contiuation hash. If it doesn't, return since
933 * there's no point to read in the successive index pages.
934 */
935 bhash = dx_get_hash(p->at);
936 if (start_hash)
937 *start_hash = bhash;
938 if ((hash & 1) == 0) {
939 if ((bhash & ~1) != hash)
940 return 0;
941 }
942 /*
943 * If the hash is HASH_NB_ALWAYS, we always go to the next
944 * block so no check is necessary
945 */
946 while (num_frames--) {
947 bh = ext4_read_dirblock(dir, dx_get_block(p->at), INDEX);
948 if (IS_ERR(bh))
949 return PTR_ERR(bh);
950 p++;
951 brelse(p->bh);
952 p->bh = bh;
953 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
954 }
955 return 1;
956 }
957
958
959 /*
960 * This function fills a red-black tree with information from a
961 * directory block. It returns the number directory entries loaded
962 * into the tree. If there is an error it is returned in err.
963 */
964 static int htree_dirblock_to_tree(struct file *dir_file,
965 struct inode *dir, ext4_lblk_t block,
966 struct dx_hash_info *hinfo,
967 __u32 start_hash, __u32 start_minor_hash)
968 {
969 struct buffer_head *bh;
970 struct ext4_dir_entry_2 *de, *top;
971 int err = 0, count = 0;
972 struct ext4_fname_crypto_ctx *ctx = NULL;
973 struct ext4_str fname_crypto_str = {.name = NULL, .len = 0}, tmp_str;
974
975 dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
976 (unsigned long)block));
977 bh = ext4_read_dirblock(dir, block, DIRENT);
978 if (IS_ERR(bh))
979 return PTR_ERR(bh);
980
981 de = (struct ext4_dir_entry_2 *) bh->b_data;
982 top = (struct ext4_dir_entry_2 *) ((char *) de +
983 dir->i_sb->s_blocksize -
984 EXT4_DIR_REC_LEN(0));
985 #ifdef CONFIG_EXT4_FS_ENCRYPTION
986 /* Check if the directory is encrypted */
987 ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN);
988 if (IS_ERR(ctx)) {
989 err = PTR_ERR(ctx);
990 brelse(bh);
991 return err;
992 }
993 if (ctx != NULL) {
994 err = ext4_fname_crypto_alloc_buffer(ctx, EXT4_NAME_LEN,
995 &fname_crypto_str);
996 if (err < 0) {
997 ext4_put_fname_crypto_ctx(&ctx);
998 brelse(bh);
999 return err;
1000 }
1001 }
1002 #endif
1003 for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) {
1004 if (ext4_check_dir_entry(dir, NULL, de, bh,
1005 bh->b_data, bh->b_size,
1006 (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
1007 + ((char *)de - bh->b_data))) {
1008 /* silently ignore the rest of the block */
1009 break;
1010 }
1011 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1012 err = ext4_fname_disk_to_hash(ctx, de, hinfo);
1013 if (err < 0) {
1014 count = err;
1015 goto errout;
1016 }
1017 #else
1018 ext4fs_dirhash(de->name, de->name_len, hinfo);
1019 #endif
1020 if ((hinfo->hash < start_hash) ||
1021 ((hinfo->hash == start_hash) &&
1022 (hinfo->minor_hash < start_minor_hash)))
1023 continue;
1024 if (de->inode == 0)
1025 continue;
1026 if (ctx == NULL) {
1027 /* Directory is not encrypted */
1028 tmp_str.name = de->name;
1029 tmp_str.len = de->name_len;
1030 err = ext4_htree_store_dirent(dir_file,
1031 hinfo->hash, hinfo->minor_hash, de,
1032 &tmp_str);
1033 } else {
1034 /* Directory is encrypted */
1035 err = ext4_fname_disk_to_usr(ctx, de,
1036 &fname_crypto_str);
1037 if (err < 0) {
1038 count = err;
1039 goto errout;
1040 }
1041 err = ext4_htree_store_dirent(dir_file,
1042 hinfo->hash, hinfo->minor_hash, de,
1043 &fname_crypto_str);
1044 }
1045 if (err != 0) {
1046 count = err;
1047 goto errout;
1048 }
1049 count++;
1050 }
1051 errout:
1052 brelse(bh);
1053 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1054 ext4_put_fname_crypto_ctx(&ctx);
1055 ext4_fname_crypto_free_buffer(&fname_crypto_str);
1056 #endif
1057 return count;
1058 }
1059
1060
1061 /*
1062 * This function fills a red-black tree with information from a
1063 * directory. We start scanning the directory in hash order, starting
1064 * at start_hash and start_minor_hash.
1065 *
1066 * This function returns the number of entries inserted into the tree,
1067 * or a negative error code.
1068 */
1069 int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
1070 __u32 start_minor_hash, __u32 *next_hash)
1071 {
1072 struct dx_hash_info hinfo;
1073 struct ext4_dir_entry_2 *de;
1074 struct dx_frame frames[2], *frame;
1075 struct inode *dir;
1076 ext4_lblk_t block;
1077 int count = 0;
1078 int ret, err;
1079 __u32 hashval;
1080 struct ext4_str tmp_str;
1081
1082 dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
1083 start_hash, start_minor_hash));
1084 dir = file_inode(dir_file);
1085 if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) {
1086 hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
1087 if (hinfo.hash_version <= DX_HASH_TEA)
1088 hinfo.hash_version +=
1089 EXT4_SB(dir->i_sb)->s_hash_unsigned;
1090 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
1091 if (ext4_has_inline_data(dir)) {
1092 int has_inline_data = 1;
1093 count = htree_inlinedir_to_tree(dir_file, dir, 0,
1094 &hinfo, start_hash,
1095 start_minor_hash,
1096 &has_inline_data);
1097 if (has_inline_data) {
1098 *next_hash = ~0;
1099 return count;
1100 }
1101 }
1102 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
1103 start_hash, start_minor_hash);
1104 *next_hash = ~0;
1105 return count;
1106 }
1107 hinfo.hash = start_hash;
1108 hinfo.minor_hash = 0;
1109 frame = dx_probe(NULL, dir, &hinfo, frames);
1110 if (IS_ERR(frame))
1111 return PTR_ERR(frame);
1112
1113 /* Add '.' and '..' from the htree header */
1114 if (!start_hash && !start_minor_hash) {
1115 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
1116 tmp_str.name = de->name;
1117 tmp_str.len = de->name_len;
1118 err = ext4_htree_store_dirent(dir_file, 0, 0,
1119 de, &tmp_str);
1120 if (err != 0)
1121 goto errout;
1122 count++;
1123 }
1124 if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
1125 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
1126 de = ext4_next_entry(de, dir->i_sb->s_blocksize);
1127 tmp_str.name = de->name;
1128 tmp_str.len = de->name_len;
1129 err = ext4_htree_store_dirent(dir_file, 2, 0,
1130 de, &tmp_str);
1131 if (err != 0)
1132 goto errout;
1133 count++;
1134 }
1135
1136 while (1) {
1137 block = dx_get_block(frame->at);
1138 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
1139 start_hash, start_minor_hash);
1140 if (ret < 0) {
1141 err = ret;
1142 goto errout;
1143 }
1144 count += ret;
1145 hashval = ~0;
1146 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
1147 frame, frames, &hashval);
1148 *next_hash = hashval;
1149 if (ret < 0) {
1150 err = ret;
1151 goto errout;
1152 }
1153 /*
1154 * Stop if: (a) there are no more entries, or
1155 * (b) we have inserted at least one entry and the
1156 * next hash value is not a continuation
1157 */
1158 if ((ret == 0) ||
1159 (count && ((hashval & 1) == 0)))
1160 break;
1161 }
1162 dx_release(frames);
1163 dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, "
1164 "next hash: %x\n", count, *next_hash));
1165 return count;
1166 errout:
1167 dx_release(frames);
1168 return (err);
1169 }
1170
1171 static inline int search_dirblock(struct buffer_head *bh,
1172 struct inode *dir,
1173 const struct qstr *d_name,
1174 unsigned int offset,
1175 struct ext4_dir_entry_2 **res_dir)
1176 {
1177 return search_dir(bh, bh->b_data, dir->i_sb->s_blocksize, dir,
1178 d_name, offset, res_dir);
1179 }
1180
1181 /*
1182 * Directory block splitting, compacting
1183 */
1184
1185 /*
1186 * Create map of hash values, offsets, and sizes, stored at end of block.
1187 * Returns number of entries mapped.
1188 */
1189 static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de,
1190 unsigned blocksize, struct dx_hash_info *hinfo,
1191 struct dx_map_entry *map_tail)
1192 {
1193 int count = 0;
1194 char *base = (char *) de;
1195 struct dx_hash_info h = *hinfo;
1196 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1197 struct ext4_fname_crypto_ctx *ctx = NULL;
1198 int err;
1199
1200 ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN);
1201 if (IS_ERR(ctx))
1202 return PTR_ERR(ctx);
1203 #endif
1204
1205 while ((char *) de < base + blocksize) {
1206 if (de->name_len && de->inode) {
1207 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1208 err = ext4_fname_disk_to_hash(ctx, de, &h);
1209 if (err < 0) {
1210 ext4_put_fname_crypto_ctx(&ctx);
1211 return err;
1212 }
1213 #else
1214 ext4fs_dirhash(de->name, de->name_len, &h);
1215 #endif
1216 map_tail--;
1217 map_tail->hash = h.hash;
1218 map_tail->offs = ((char *) de - base)>>2;
1219 map_tail->size = le16_to_cpu(de->rec_len);
1220 count++;
1221 cond_resched();
1222 }
1223 /* XXX: do we need to check rec_len == 0 case? -Chris */
1224 de = ext4_next_entry(de, blocksize);
1225 }
1226 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1227 ext4_put_fname_crypto_ctx(&ctx);
1228 #endif
1229 return count;
1230 }
1231
1232 /* Sort map by hash value */
1233 static void dx_sort_map (struct dx_map_entry *map, unsigned count)
1234 {
1235 struct dx_map_entry *p, *q, *top = map + count - 1;
1236 int more;
1237 /* Combsort until bubble sort doesn't suck */
1238 while (count > 2) {
1239 count = count*10/13;
1240 if (count - 9 < 2) /* 9, 10 -> 11 */
1241 count = 11;
1242 for (p = top, q = p - count; q >= map; p--, q--)
1243 if (p->hash < q->hash)
1244 swap(*p, *q);
1245 }
1246 /* Garden variety bubble sort */
1247 do {
1248 more = 0;
1249 q = top;
1250 while (q-- > map) {
1251 if (q[1].hash >= q[0].hash)
1252 continue;
1253 swap(*(q+1), *q);
1254 more = 1;
1255 }
1256 } while(more);
1257 }
1258
1259 static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
1260 {
1261 struct dx_entry *entries = frame->entries;
1262 struct dx_entry *old = frame->at, *new = old + 1;
1263 int count = dx_get_count(entries);
1264
1265 assert(count < dx_get_limit(entries));
1266 assert(old < entries + count);
1267 memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
1268 dx_set_hash(new, hash);
1269 dx_set_block(new, block);
1270 dx_set_count(entries, count + 1);
1271 }
1272
1273 /*
1274 * NOTE! unlike strncmp, ext4_match returns 1 for success, 0 for failure.
1275 *
1276 * `len <= EXT4_NAME_LEN' is guaranteed by caller.
1277 * `de != NULL' is guaranteed by caller.
1278 */
1279 static inline int ext4_match(struct ext4_fname_crypto_ctx *ctx,
1280 struct ext4_str *fname_crypto_str,
1281 int len, const char * const name,
1282 struct ext4_dir_entry_2 *de)
1283 {
1284 int res;
1285
1286 if (!de->inode)
1287 return 0;
1288
1289 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1290 if (ctx) {
1291 /* Directory is encrypted */
1292 res = ext4_fname_disk_to_usr(ctx, de, fname_crypto_str);
1293 if (res < 0)
1294 return res;
1295 if (len != res)
1296 return 0;
1297 res = memcmp(name, fname_crypto_str->name, len);
1298 return (res == 0) ? 1 : 0;
1299 }
1300 #endif
1301 if (len != de->name_len)
1302 return 0;
1303 res = memcmp(name, de->name, len);
1304 return (res == 0) ? 1 : 0;
1305 }
1306
1307 /*
1308 * Returns 0 if not found, -1 on failure, and 1 on success
1309 */
1310 int search_dir(struct buffer_head *bh, char *search_buf, int buf_size,
1311 struct inode *dir, const struct qstr *d_name,
1312 unsigned int offset, struct ext4_dir_entry_2 **res_dir)
1313 {
1314 struct ext4_dir_entry_2 * de;
1315 char * dlimit;
1316 int de_len;
1317 const char *name = d_name->name;
1318 int namelen = d_name->len;
1319 struct ext4_fname_crypto_ctx *ctx = NULL;
1320 struct ext4_str fname_crypto_str = {.name = NULL, .len = 0};
1321 int res;
1322
1323 ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN);
1324 if (IS_ERR(ctx))
1325 return -1;
1326
1327 if (ctx != NULL) {
1328 /* Allocate buffer to hold maximum name length */
1329 res = ext4_fname_crypto_alloc_buffer(ctx, EXT4_NAME_LEN,
1330 &fname_crypto_str);
1331 if (res < 0) {
1332 ext4_put_fname_crypto_ctx(&ctx);
1333 return -1;
1334 }
1335 }
1336
1337 de = (struct ext4_dir_entry_2 *)search_buf;
1338 dlimit = search_buf + buf_size;
1339 while ((char *) de < dlimit) {
1340 /* this code is executed quadratically often */
1341 /* do minimal checking `by hand' */
1342 if ((char *) de + de->name_len <= dlimit) {
1343 res = ext4_match(ctx, &fname_crypto_str, namelen,
1344 name, de);
1345 if (res < 0) {
1346 res = -1;
1347 goto return_result;
1348 }
1349 if (res > 0) {
1350 /* found a match - just to be sure, do
1351 * a full check */
1352 if (ext4_check_dir_entry(dir, NULL, de, bh,
1353 bh->b_data,
1354 bh->b_size, offset)) {
1355 res = -1;
1356 goto return_result;
1357 }
1358 *res_dir = de;
1359 res = 1;
1360 goto return_result;
1361 }
1362
1363 }
1364 /* prevent looping on a bad block */
1365 de_len = ext4_rec_len_from_disk(de->rec_len,
1366 dir->i_sb->s_blocksize);
1367 if (de_len <= 0) {
1368 res = -1;
1369 goto return_result;
1370 }
1371 offset += de_len;
1372 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
1373 }
1374
1375 res = 0;
1376 return_result:
1377 ext4_put_fname_crypto_ctx(&ctx);
1378 ext4_fname_crypto_free_buffer(&fname_crypto_str);
1379 return res;
1380 }
1381
1382 static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block,
1383 struct ext4_dir_entry *de)
1384 {
1385 struct super_block *sb = dir->i_sb;
1386
1387 if (!is_dx(dir))
1388 return 0;
1389 if (block == 0)
1390 return 1;
1391 if (de->inode == 0 &&
1392 ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) ==
1393 sb->s_blocksize)
1394 return 1;
1395 return 0;
1396 }
1397
1398 /*
1399 * ext4_find_entry()
1400 *
1401 * finds an entry in the specified directory with the wanted name. It
1402 * returns the cache buffer in which the entry was found, and the entry
1403 * itself (as a parameter - res_dir). It does NOT read the inode of the
1404 * entry - you'll have to do that yourself if you want to.
1405 *
1406 * The returned buffer_head has ->b_count elevated. The caller is expected
1407 * to brelse() it when appropriate.
1408 */
1409 static struct buffer_head * ext4_find_entry (struct inode *dir,
1410 const struct qstr *d_name,
1411 struct ext4_dir_entry_2 **res_dir,
1412 int *inlined)
1413 {
1414 struct super_block *sb;
1415 struct buffer_head *bh_use[NAMEI_RA_SIZE];
1416 struct buffer_head *bh, *ret = NULL;
1417 ext4_lblk_t start, block, b;
1418 const u8 *name = d_name->name;
1419 int ra_max = 0; /* Number of bh's in the readahead
1420 buffer, bh_use[] */
1421 int ra_ptr = 0; /* Current index into readahead
1422 buffer */
1423 int num = 0;
1424 ext4_lblk_t nblocks;
1425 int i, namelen;
1426
1427 *res_dir = NULL;
1428 sb = dir->i_sb;
1429 namelen = d_name->len;
1430 if (namelen > EXT4_NAME_LEN)
1431 return NULL;
1432
1433 if (ext4_has_inline_data(dir)) {
1434 int has_inline_data = 1;
1435 ret = ext4_find_inline_entry(dir, d_name, res_dir,
1436 &has_inline_data);
1437 if (has_inline_data) {
1438 if (inlined)
1439 *inlined = 1;
1440 return ret;
1441 }
1442 }
1443
1444 if ((namelen <= 2) && (name[0] == '.') &&
1445 (name[1] == '.' || name[1] == '\0')) {
1446 /*
1447 * "." or ".." will only be in the first block
1448 * NFS may look up ".."; "." should be handled by the VFS
1449 */
1450 block = start = 0;
1451 nblocks = 1;
1452 goto restart;
1453 }
1454 if (is_dx(dir)) {
1455 bh = ext4_dx_find_entry(dir, d_name, res_dir);
1456 /*
1457 * On success, or if the error was file not found,
1458 * return. Otherwise, fall back to doing a search the
1459 * old fashioned way.
1460 */
1461 if (!IS_ERR(bh) || PTR_ERR(bh) != ERR_BAD_DX_DIR)
1462 return bh;
1463 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
1464 "falling back\n"));
1465 }
1466 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1467 start = EXT4_I(dir)->i_dir_start_lookup;
1468 if (start >= nblocks)
1469 start = 0;
1470 block = start;
1471 restart:
1472 do {
1473 /*
1474 * We deal with the read-ahead logic here.
1475 */
1476 if (ra_ptr >= ra_max) {
1477 /* Refill the readahead buffer */
1478 ra_ptr = 0;
1479 b = block;
1480 for (ra_max = 0; ra_max < NAMEI_RA_SIZE; ra_max++) {
1481 /*
1482 * Terminate if we reach the end of the
1483 * directory and must wrap, or if our
1484 * search has finished at this block.
1485 */
1486 if (b >= nblocks || (num && block == start)) {
1487 bh_use[ra_max] = NULL;
1488 break;
1489 }
1490 num++;
1491 bh = ext4_getblk(NULL, dir, b++, 0);
1492 if (unlikely(IS_ERR(bh))) {
1493 if (ra_max == 0)
1494 return bh;
1495 break;
1496 }
1497 bh_use[ra_max] = bh;
1498 if (bh)
1499 ll_rw_block(READ | REQ_META | REQ_PRIO,
1500 1, &bh);
1501 }
1502 }
1503 if ((bh = bh_use[ra_ptr++]) == NULL)
1504 goto next;
1505 wait_on_buffer(bh);
1506 if (!buffer_uptodate(bh)) {
1507 /* read error, skip block & hope for the best */
1508 EXT4_ERROR_INODE(dir, "reading directory lblock %lu",
1509 (unsigned long) block);
1510 brelse(bh);
1511 goto next;
1512 }
1513 if (!buffer_verified(bh) &&
1514 !is_dx_internal_node(dir, block,
1515 (struct ext4_dir_entry *)bh->b_data) &&
1516 !ext4_dirent_csum_verify(dir,
1517 (struct ext4_dir_entry *)bh->b_data)) {
1518 EXT4_ERROR_INODE(dir, "checksumming directory "
1519 "block %lu", (unsigned long)block);
1520 brelse(bh);
1521 goto next;
1522 }
1523 set_buffer_verified(bh);
1524 i = search_dirblock(bh, dir, d_name,
1525 block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
1526 if (i == 1) {
1527 EXT4_I(dir)->i_dir_start_lookup = block;
1528 ret = bh;
1529 goto cleanup_and_exit;
1530 } else {
1531 brelse(bh);
1532 if (i < 0)
1533 goto cleanup_and_exit;
1534 }
1535 next:
1536 if (++block >= nblocks)
1537 block = 0;
1538 } while (block != start);
1539
1540 /*
1541 * If the directory has grown while we were searching, then
1542 * search the last part of the directory before giving up.
1543 */
1544 block = nblocks;
1545 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1546 if (block < nblocks) {
1547 start = 0;
1548 goto restart;
1549 }
1550
1551 cleanup_and_exit:
1552 /* Clean up the read-ahead blocks */
1553 for (; ra_ptr < ra_max; ra_ptr++)
1554 brelse(bh_use[ra_ptr]);
1555 return ret;
1556 }
1557
1558 static struct buffer_head * ext4_dx_find_entry(struct inode *dir, const struct qstr *d_name,
1559 struct ext4_dir_entry_2 **res_dir)
1560 {
1561 struct super_block * sb = dir->i_sb;
1562 struct dx_hash_info hinfo;
1563 struct dx_frame frames[2], *frame;
1564 struct buffer_head *bh;
1565 ext4_lblk_t block;
1566 int retval;
1567
1568 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1569 *res_dir = NULL;
1570 #endif
1571 frame = dx_probe(d_name, dir, &hinfo, frames);
1572 if (IS_ERR(frame))
1573 return (struct buffer_head *) frame;
1574 do {
1575 block = dx_get_block(frame->at);
1576 bh = ext4_read_dirblock(dir, block, DIRENT);
1577 if (IS_ERR(bh))
1578 goto errout;
1579
1580 retval = search_dirblock(bh, dir, d_name,
1581 block << EXT4_BLOCK_SIZE_BITS(sb),
1582 res_dir);
1583 if (retval == 1)
1584 goto success;
1585 brelse(bh);
1586 if (retval == -1) {
1587 bh = ERR_PTR(ERR_BAD_DX_DIR);
1588 goto errout;
1589 }
1590
1591 /* Check to see if we should continue to search */
1592 retval = ext4_htree_next_block(dir, hinfo.hash, frame,
1593 frames, NULL);
1594 if (retval < 0) {
1595 ext4_warning(sb,
1596 "error %d reading index page in directory #%lu",
1597 retval, dir->i_ino);
1598 bh = ERR_PTR(retval);
1599 goto errout;
1600 }
1601 } while (retval == 1);
1602
1603 bh = NULL;
1604 errout:
1605 dxtrace(printk(KERN_DEBUG "%s not found\n", d_name->name));
1606 success:
1607 dx_release(frames);
1608 return bh;
1609 }
1610
1611 static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
1612 {
1613 struct inode *inode;
1614 struct ext4_dir_entry_2 *de;
1615 struct buffer_head *bh;
1616
1617 if (dentry->d_name.len > EXT4_NAME_LEN)
1618 return ERR_PTR(-ENAMETOOLONG);
1619
1620 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
1621 if (IS_ERR(bh))
1622 return (struct dentry *) bh;
1623 inode = NULL;
1624 if (bh) {
1625 __u32 ino = le32_to_cpu(de->inode);
1626 brelse(bh);
1627 if (!ext4_valid_inum(dir->i_sb, ino)) {
1628 EXT4_ERROR_INODE(dir, "bad inode number: %u", ino);
1629 return ERR_PTR(-EIO);
1630 }
1631 if (unlikely(ino == dir->i_ino)) {
1632 EXT4_ERROR_INODE(dir, "'%pd' linked to parent dir",
1633 dentry);
1634 return ERR_PTR(-EIO);
1635 }
1636 inode = ext4_iget_normal(dir->i_sb, ino);
1637 if (inode == ERR_PTR(-ESTALE)) {
1638 EXT4_ERROR_INODE(dir,
1639 "deleted inode referenced: %u",
1640 ino);
1641 return ERR_PTR(-EIO);
1642 }
1643 if (!IS_ERR(inode) && ext4_encrypted_inode(dir) &&
1644 (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
1645 S_ISLNK(inode->i_mode)) &&
1646 !ext4_is_child_context_consistent_with_parent(dir,
1647 inode)) {
1648 iput(inode);
1649 ext4_warning(inode->i_sb,
1650 "Inconsistent encryption contexts: %lu/%lu\n",
1651 (unsigned long) dir->i_ino,
1652 (unsigned long) inode->i_ino);
1653 return ERR_PTR(-EPERM);
1654 }
1655 }
1656 return d_splice_alias(inode, dentry);
1657 }
1658
1659
1660 struct dentry *ext4_get_parent(struct dentry *child)
1661 {
1662 __u32 ino;
1663 static const struct qstr dotdot = QSTR_INIT("..", 2);
1664 struct ext4_dir_entry_2 * de;
1665 struct buffer_head *bh;
1666
1667 bh = ext4_find_entry(d_inode(child), &dotdot, &de, NULL);
1668 if (IS_ERR(bh))
1669 return (struct dentry *) bh;
1670 if (!bh)
1671 return ERR_PTR(-ENOENT);
1672 ino = le32_to_cpu(de->inode);
1673 brelse(bh);
1674
1675 if (!ext4_valid_inum(d_inode(child)->i_sb, ino)) {
1676 EXT4_ERROR_INODE(d_inode(child),
1677 "bad parent inode number: %u", ino);
1678 return ERR_PTR(-EIO);
1679 }
1680
1681 return d_obtain_alias(ext4_iget_normal(d_inode(child)->i_sb, ino));
1682 }
1683
1684 /*
1685 * Move count entries from end of map between two memory locations.
1686 * Returns pointer to last entry moved.
1687 */
1688 static struct ext4_dir_entry_2 *
1689 dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count,
1690 unsigned blocksize)
1691 {
1692 unsigned rec_len = 0;
1693
1694 while (count--) {
1695 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
1696 (from + (map->offs<<2));
1697 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1698 memcpy (to, de, rec_len);
1699 ((struct ext4_dir_entry_2 *) to)->rec_len =
1700 ext4_rec_len_to_disk(rec_len, blocksize);
1701 de->inode = 0;
1702 map++;
1703 to += rec_len;
1704 }
1705 return (struct ext4_dir_entry_2 *) (to - rec_len);
1706 }
1707
1708 /*
1709 * Compact each dir entry in the range to the minimal rec_len.
1710 * Returns pointer to last entry in range.
1711 */
1712 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize)
1713 {
1714 struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
1715 unsigned rec_len = 0;
1716
1717 prev = to = de;
1718 while ((char*)de < base + blocksize) {
1719 next = ext4_next_entry(de, blocksize);
1720 if (de->inode && de->name_len) {
1721 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1722 if (de > to)
1723 memmove(to, de, rec_len);
1724 to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
1725 prev = to;
1726 to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
1727 }
1728 de = next;
1729 }
1730 return prev;
1731 }
1732
1733 /*
1734 * Split a full leaf block to make room for a new dir entry.
1735 * Allocate a new block, and move entries so that they are approx. equally full.
1736 * Returns pointer to de in block into which the new entry will be inserted.
1737 */
1738 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
1739 struct buffer_head **bh,struct dx_frame *frame,
1740 struct dx_hash_info *hinfo)
1741 {
1742 unsigned blocksize = dir->i_sb->s_blocksize;
1743 unsigned count, continued;
1744 struct buffer_head *bh2;
1745 ext4_lblk_t newblock;
1746 u32 hash2;
1747 struct dx_map_entry *map;
1748 char *data1 = (*bh)->b_data, *data2;
1749 unsigned split, move, size;
1750 struct ext4_dir_entry_2 *de = NULL, *de2;
1751 struct ext4_dir_entry_tail *t;
1752 int csum_size = 0;
1753 int err = 0, i;
1754
1755 if (ext4_has_metadata_csum(dir->i_sb))
1756 csum_size = sizeof(struct ext4_dir_entry_tail);
1757
1758 bh2 = ext4_append(handle, dir, &newblock);
1759 if (IS_ERR(bh2)) {
1760 brelse(*bh);
1761 *bh = NULL;
1762 return (struct ext4_dir_entry_2 *) bh2;
1763 }
1764
1765 BUFFER_TRACE(*bh, "get_write_access");
1766 err = ext4_journal_get_write_access(handle, *bh);
1767 if (err)
1768 goto journal_error;
1769
1770 BUFFER_TRACE(frame->bh, "get_write_access");
1771 err = ext4_journal_get_write_access(handle, frame->bh);
1772 if (err)
1773 goto journal_error;
1774
1775 data2 = bh2->b_data;
1776
1777 /* create map in the end of data2 block */
1778 map = (struct dx_map_entry *) (data2 + blocksize);
1779 count = dx_make_map(dir, (struct ext4_dir_entry_2 *) data1,
1780 blocksize, hinfo, map);
1781 map -= count;
1782 dx_sort_map(map, count);
1783 /* Split the existing block in the middle, size-wise */
1784 size = 0;
1785 move = 0;
1786 for (i = count-1; i >= 0; i--) {
1787 /* is more than half of this entry in 2nd half of the block? */
1788 if (size + map[i].size/2 > blocksize/2)
1789 break;
1790 size += map[i].size;
1791 move++;
1792 }
1793 /* map index at which we will split */
1794 split = count - move;
1795 hash2 = map[split].hash;
1796 continued = hash2 == map[split - 1].hash;
1797 dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
1798 (unsigned long)dx_get_block(frame->at),
1799 hash2, split, count-split));
1800
1801 /* Fancy dance to stay within two buffers */
1802 de2 = dx_move_dirents(data1, data2, map + split, count - split,
1803 blocksize);
1804 de = dx_pack_dirents(data1, blocksize);
1805 de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
1806 (char *) de,
1807 blocksize);
1808 de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
1809 (char *) de2,
1810 blocksize);
1811 if (csum_size) {
1812 t = EXT4_DIRENT_TAIL(data2, blocksize);
1813 initialize_dirent_tail(t, blocksize);
1814
1815 t = EXT4_DIRENT_TAIL(data1, blocksize);
1816 initialize_dirent_tail(t, blocksize);
1817 }
1818
1819 dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data1,
1820 blocksize, 1));
1821 dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data2,
1822 blocksize, 1));
1823
1824 /* Which block gets the new entry? */
1825 if (hinfo->hash >= hash2) {
1826 swap(*bh, bh2);
1827 de = de2;
1828 }
1829 dx_insert_block(frame, hash2 + continued, newblock);
1830 err = ext4_handle_dirty_dirent_node(handle, dir, bh2);
1831 if (err)
1832 goto journal_error;
1833 err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
1834 if (err)
1835 goto journal_error;
1836 brelse(bh2);
1837 dxtrace(dx_show_index("frame", frame->entries));
1838 return de;
1839
1840 journal_error:
1841 brelse(*bh);
1842 brelse(bh2);
1843 *bh = NULL;
1844 ext4_std_error(dir->i_sb, err);
1845 return ERR_PTR(err);
1846 }
1847
1848 int ext4_find_dest_de(struct inode *dir, struct inode *inode,
1849 struct buffer_head *bh,
1850 void *buf, int buf_size,
1851 const char *name, int namelen,
1852 struct ext4_dir_entry_2 **dest_de)
1853 {
1854 struct ext4_dir_entry_2 *de;
1855 unsigned short reclen = EXT4_DIR_REC_LEN(namelen);
1856 int nlen, rlen;
1857 unsigned int offset = 0;
1858 char *top;
1859 struct ext4_fname_crypto_ctx *ctx = NULL;
1860 struct ext4_str fname_crypto_str = {.name = NULL, .len = 0};
1861 int res;
1862
1863 ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN);
1864 if (IS_ERR(ctx))
1865 return -1;
1866
1867 if (ctx != NULL) {
1868 /* Calculate record length needed to store the entry */
1869 res = ext4_fname_crypto_namelen_on_disk(ctx, namelen);
1870 if (res < 0) {
1871 ext4_put_fname_crypto_ctx(&ctx);
1872 return res;
1873 }
1874 reclen = EXT4_DIR_REC_LEN(res);
1875
1876 /* Allocate buffer to hold maximum name length */
1877 res = ext4_fname_crypto_alloc_buffer(ctx, EXT4_NAME_LEN,
1878 &fname_crypto_str);
1879 if (res < 0) {
1880 ext4_put_fname_crypto_ctx(&ctx);
1881 return -1;
1882 }
1883 }
1884
1885 de = (struct ext4_dir_entry_2 *)buf;
1886 top = buf + buf_size - reclen;
1887 while ((char *) de <= top) {
1888 if (ext4_check_dir_entry(dir, NULL, de, bh,
1889 buf, buf_size, offset)) {
1890 res = -EIO;
1891 goto return_result;
1892 }
1893 /* Provide crypto context and crypto buffer to ext4 match */
1894 res = ext4_match(ctx, &fname_crypto_str, namelen, name, de);
1895 if (res < 0)
1896 goto return_result;
1897 if (res > 0) {
1898 res = -EEXIST;
1899 goto return_result;
1900 }
1901 nlen = EXT4_DIR_REC_LEN(de->name_len);
1902 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
1903 if ((de->inode ? rlen - nlen : rlen) >= reclen)
1904 break;
1905 de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
1906 offset += rlen;
1907 }
1908
1909 if ((char *) de > top)
1910 res = -ENOSPC;
1911 else {
1912 *dest_de = de;
1913 res = 0;
1914 }
1915 return_result:
1916 ext4_put_fname_crypto_ctx(&ctx);
1917 ext4_fname_crypto_free_buffer(&fname_crypto_str);
1918 return res;
1919 }
1920
1921 int ext4_insert_dentry(struct inode *dir,
1922 struct inode *inode,
1923 struct ext4_dir_entry_2 *de,
1924 int buf_size,
1925 const struct qstr *iname,
1926 const char *name, int namelen)
1927 {
1928
1929 int nlen, rlen;
1930 struct ext4_fname_crypto_ctx *ctx = NULL;
1931 struct ext4_str fname_crypto_str = {.name = NULL, .len = 0};
1932 struct ext4_str tmp_str;
1933 int res;
1934
1935 ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN);
1936 if (IS_ERR(ctx))
1937 return -EIO;
1938 /* By default, the input name would be written to the disk */
1939 tmp_str.name = (unsigned char *)name;
1940 tmp_str.len = namelen;
1941 if (ctx != NULL) {
1942 /* Directory is encrypted */
1943 res = ext4_fname_crypto_alloc_buffer(ctx, EXT4_NAME_LEN,
1944 &fname_crypto_str);
1945 if (res < 0) {
1946 ext4_put_fname_crypto_ctx(&ctx);
1947 return -ENOMEM;
1948 }
1949 res = ext4_fname_usr_to_disk(ctx, iname, &fname_crypto_str);
1950 if (res < 0) {
1951 ext4_put_fname_crypto_ctx(&ctx);
1952 ext4_fname_crypto_free_buffer(&fname_crypto_str);
1953 return res;
1954 }
1955 tmp_str.name = fname_crypto_str.name;
1956 tmp_str.len = fname_crypto_str.len;
1957 }
1958
1959 nlen = EXT4_DIR_REC_LEN(de->name_len);
1960 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
1961 if (de->inode) {
1962 struct ext4_dir_entry_2 *de1 =
1963 (struct ext4_dir_entry_2 *)((char *)de + nlen);
1964 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, buf_size);
1965 de->rec_len = ext4_rec_len_to_disk(nlen, buf_size);
1966 de = de1;
1967 }
1968 de->file_type = EXT4_FT_UNKNOWN;
1969 de->inode = cpu_to_le32(inode->i_ino);
1970 ext4_set_de_type(inode->i_sb, de, inode->i_mode);
1971 de->name_len = tmp_str.len;
1972
1973 memcpy(de->name, tmp_str.name, tmp_str.len);
1974 ext4_put_fname_crypto_ctx(&ctx);
1975 ext4_fname_crypto_free_buffer(&fname_crypto_str);
1976 return 0;
1977 }
1978
1979 /*
1980 * Add a new entry into a directory (leaf) block. If de is non-NULL,
1981 * it points to a directory entry which is guaranteed to be large
1982 * enough for new directory entry. If de is NULL, then
1983 * add_dirent_to_buf will attempt search the directory block for
1984 * space. It will return -ENOSPC if no space is available, and -EIO
1985 * and -EEXIST if directory entry already exists.
1986 */
1987 static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
1988 struct inode *inode, struct ext4_dir_entry_2 *de,
1989 struct buffer_head *bh)
1990 {
1991 struct inode *dir = d_inode(dentry->d_parent);
1992 const char *name = dentry->d_name.name;
1993 int namelen = dentry->d_name.len;
1994 unsigned int blocksize = dir->i_sb->s_blocksize;
1995 int csum_size = 0;
1996 int err;
1997
1998 if (ext4_has_metadata_csum(inode->i_sb))
1999 csum_size = sizeof(struct ext4_dir_entry_tail);
2000
2001 if (!de) {
2002 err = ext4_find_dest_de(dir, inode,
2003 bh, bh->b_data, blocksize - csum_size,
2004 name, namelen, &de);
2005 if (err)
2006 return err;
2007 }
2008 BUFFER_TRACE(bh, "get_write_access");
2009 err = ext4_journal_get_write_access(handle, bh);
2010 if (err) {
2011 ext4_std_error(dir->i_sb, err);
2012 return err;
2013 }
2014
2015 /* By now the buffer is marked for journaling. Due to crypto operations,
2016 * the following function call may fail */
2017 err = ext4_insert_dentry(dir, inode, de, blocksize, &dentry->d_name,
2018 name, namelen);
2019 if (err < 0)
2020 return err;
2021
2022 /*
2023 * XXX shouldn't update any times until successful
2024 * completion of syscall, but too many callers depend
2025 * on this.
2026 *
2027 * XXX similarly, too many callers depend on
2028 * ext4_new_inode() setting the times, but error
2029 * recovery deletes the inode, so the worst that can
2030 * happen is that the times are slightly out of date
2031 * and/or different from the directory change time.
2032 */
2033 dir->i_mtime = dir->i_ctime = ext4_current_time(dir);
2034 ext4_update_dx_flag(dir);
2035 dir->i_version++;
2036 ext4_mark_inode_dirty(handle, dir);
2037 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
2038 err = ext4_handle_dirty_dirent_node(handle, dir, bh);
2039 if (err)
2040 ext4_std_error(dir->i_sb, err);
2041 return 0;
2042 }
2043
2044 /*
2045 * This converts a one block unindexed directory to a 3 block indexed
2046 * directory, and adds the dentry to the indexed directory.
2047 */
2048 static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
2049 struct inode *inode, struct buffer_head *bh)
2050 {
2051 struct inode *dir = d_inode(dentry->d_parent);
2052 #ifdef CONFIG_EXT4_FS_ENCRYPTION
2053 struct ext4_fname_crypto_ctx *ctx = NULL;
2054 int res;
2055 #else
2056 const char *name = dentry->d_name.name;
2057 int namelen = dentry->d_name.len;
2058 #endif
2059 struct buffer_head *bh2;
2060 struct dx_root *root;
2061 struct dx_frame frames[2], *frame;
2062 struct dx_entry *entries;
2063 struct ext4_dir_entry_2 *de, *de2;
2064 struct ext4_dir_entry_tail *t;
2065 char *data1, *top;
2066 unsigned len;
2067 int retval;
2068 unsigned blocksize;
2069 struct dx_hash_info hinfo;
2070 ext4_lblk_t block;
2071 struct fake_dirent *fde;
2072 int csum_size = 0;
2073
2074 #ifdef CONFIG_EXT4_FS_ENCRYPTION
2075 ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN);
2076 if (IS_ERR(ctx))
2077 return PTR_ERR(ctx);
2078 #endif
2079
2080 if (ext4_has_metadata_csum(inode->i_sb))
2081 csum_size = sizeof(struct ext4_dir_entry_tail);
2082
2083 blocksize = dir->i_sb->s_blocksize;
2084 dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
2085 BUFFER_TRACE(bh, "get_write_access");
2086 retval = ext4_journal_get_write_access(handle, bh);
2087 if (retval) {
2088 ext4_std_error(dir->i_sb, retval);
2089 brelse(bh);
2090 return retval;
2091 }
2092 root = (struct dx_root *) bh->b_data;
2093
2094 /* The 0th block becomes the root, move the dirents out */
2095 fde = &root->dotdot;
2096 de = (struct ext4_dir_entry_2 *)((char *)fde +
2097 ext4_rec_len_from_disk(fde->rec_len, blocksize));
2098 if ((char *) de >= (((char *) root) + blocksize)) {
2099 EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
2100 brelse(bh);
2101 return -EIO;
2102 }
2103 len = ((char *) root) + (blocksize - csum_size) - (char *) de;
2104
2105 /* Allocate new block for the 0th block's dirents */
2106 bh2 = ext4_append(handle, dir, &block);
2107 if (IS_ERR(bh2)) {
2108 brelse(bh);
2109 return PTR_ERR(bh2);
2110 }
2111 ext4_set_inode_flag(dir, EXT4_INODE_INDEX);
2112 data1 = bh2->b_data;
2113
2114 memcpy (data1, de, len);
2115 de = (struct ext4_dir_entry_2 *) data1;
2116 top = data1 + len;
2117 while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
2118 de = de2;
2119 de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
2120 (char *) de,
2121 blocksize);
2122
2123 if (csum_size) {
2124 t = EXT4_DIRENT_TAIL(data1, blocksize);
2125 initialize_dirent_tail(t, blocksize);
2126 }
2127
2128 /* Initialize the root; the dot dirents already exist */
2129 de = (struct ext4_dir_entry_2 *) (&root->dotdot);
2130 de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
2131 blocksize);
2132 memset (&root->info, 0, sizeof(root->info));
2133 root->info.info_length = sizeof(root->info);
2134 root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
2135 entries = root->entries;
2136 dx_set_block(entries, 1);
2137 dx_set_count(entries, 1);
2138 dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
2139
2140 /* Initialize as for dx_probe */
2141 hinfo.hash_version = root->info.hash_version;
2142 if (hinfo.hash_version <= DX_HASH_TEA)
2143 hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
2144 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
2145 #ifdef CONFIG_EXT4_FS_ENCRYPTION
2146 res = ext4_fname_usr_to_hash(ctx, &dentry->d_name, &hinfo);
2147 if (res < 0) {
2148 ext4_put_fname_crypto_ctx(&ctx);
2149 ext4_mark_inode_dirty(handle, dir);
2150 brelse(bh);
2151 return res;
2152 }
2153 ext4_put_fname_crypto_ctx(&ctx);
2154 #else
2155 ext4fs_dirhash(name, namelen, &hinfo);
2156 #endif
2157 memset(frames, 0, sizeof(frames));
2158 frame = frames;
2159 frame->entries = entries;
2160 frame->at = entries;
2161 frame->bh = bh;
2162 bh = bh2;
2163
2164 retval = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
2165 if (retval)
2166 goto out_frames;
2167 retval = ext4_handle_dirty_dirent_node(handle, dir, bh);
2168 if (retval)
2169 goto out_frames;
2170
2171 de = do_split(handle,dir, &bh, frame, &hinfo);
2172 if (IS_ERR(de)) {
2173 retval = PTR_ERR(de);
2174 goto out_frames;
2175 }
2176 dx_release(frames);
2177
2178 retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
2179 brelse(bh);
2180 return retval;
2181 out_frames:
2182 /*
2183 * Even if the block split failed, we have to properly write
2184 * out all the changes we did so far. Otherwise we can end up
2185 * with corrupted filesystem.
2186 */
2187 ext4_mark_inode_dirty(handle, dir);
2188 dx_release(frames);
2189 return retval;
2190 }
2191
2192 /*
2193 * ext4_add_entry()
2194 *
2195 * adds a file entry to the specified directory, using the same
2196 * semantics as ext4_find_entry(). It returns NULL if it failed.
2197 *
2198 * NOTE!! The inode part of 'de' is left at 0 - which means you
2199 * may not sleep between calling this and putting something into
2200 * the entry, as someone else might have used it while you slept.
2201 */
2202 static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
2203 struct inode *inode)
2204 {
2205 struct inode *dir = d_inode(dentry->d_parent);
2206 struct buffer_head *bh = NULL;
2207 struct ext4_dir_entry_2 *de;
2208 struct ext4_dir_entry_tail *t;
2209 struct super_block *sb;
2210 int retval;
2211 int dx_fallback=0;
2212 unsigned blocksize;
2213 ext4_lblk_t block, blocks;
2214 int csum_size = 0;
2215
2216 if (ext4_has_metadata_csum(inode->i_sb))
2217 csum_size = sizeof(struct ext4_dir_entry_tail);
2218
2219 sb = dir->i_sb;
2220 blocksize = sb->s_blocksize;
2221 if (!dentry->d_name.len)
2222 return -EINVAL;
2223
2224 if (ext4_has_inline_data(dir)) {
2225 retval = ext4_try_add_inline_entry(handle, dentry, inode);
2226 if (retval < 0)
2227 return retval;
2228 if (retval == 1) {
2229 retval = 0;
2230 goto out;
2231 }
2232 }
2233
2234 if (is_dx(dir)) {
2235 retval = ext4_dx_add_entry(handle, dentry, inode);
2236 if (!retval || (retval != ERR_BAD_DX_DIR))
2237 goto out;
2238 ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
2239 dx_fallback++;
2240 ext4_mark_inode_dirty(handle, dir);
2241 }
2242 blocks = dir->i_size >> sb->s_blocksize_bits;
2243 for (block = 0; block < blocks; block++) {
2244 bh = ext4_read_dirblock(dir, block, DIRENT);
2245 if (IS_ERR(bh))
2246 return PTR_ERR(bh);
2247
2248 retval = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
2249 if (retval != -ENOSPC)
2250 goto out;
2251
2252 if (blocks == 1 && !dx_fallback &&
2253 EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX)) {
2254 retval = make_indexed_dir(handle, dentry, inode, bh);
2255 bh = NULL; /* make_indexed_dir releases bh */
2256 goto out;
2257 }
2258 brelse(bh);
2259 }
2260 bh = ext4_append(handle, dir, &block);
2261 if (IS_ERR(bh))
2262 return PTR_ERR(bh);
2263 de = (struct ext4_dir_entry_2 *) bh->b_data;
2264 de->inode = 0;
2265 de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize);
2266
2267 if (csum_size) {
2268 t = EXT4_DIRENT_TAIL(bh->b_data, blocksize);
2269 initialize_dirent_tail(t, blocksize);
2270 }
2271
2272 retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
2273 out:
2274 brelse(bh);
2275 if (retval == 0)
2276 ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY);
2277 return retval;
2278 }
2279
2280 /*
2281 * Returns 0 for success, or a negative error value
2282 */
2283 static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
2284 struct inode *inode)
2285 {
2286 struct dx_frame frames[2], *frame;
2287 struct dx_entry *entries, *at;
2288 struct dx_hash_info hinfo;
2289 struct buffer_head *bh;
2290 struct inode *dir = d_inode(dentry->d_parent);
2291 struct super_block *sb = dir->i_sb;
2292 struct ext4_dir_entry_2 *de;
2293 int err;
2294
2295 frame = dx_probe(&dentry->d_name, dir, &hinfo, frames);
2296 if (IS_ERR(frame))
2297 return PTR_ERR(frame);
2298 entries = frame->entries;
2299 at = frame->at;
2300 bh = ext4_read_dirblock(dir, dx_get_block(frame->at), DIRENT);
2301 if (IS_ERR(bh)) {
2302 err = PTR_ERR(bh);
2303 bh = NULL;
2304 goto cleanup;
2305 }
2306
2307 BUFFER_TRACE(bh, "get_write_access");
2308 err = ext4_journal_get_write_access(handle, bh);
2309 if (err)
2310 goto journal_error;
2311
2312 err = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
2313 if (err != -ENOSPC)
2314 goto cleanup;
2315
2316 /* Block full, should compress but for now just split */
2317 dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
2318 dx_get_count(entries), dx_get_limit(entries)));
2319 /* Need to split index? */
2320 if (dx_get_count(entries) == dx_get_limit(entries)) {
2321 ext4_lblk_t newblock;
2322 unsigned icount = dx_get_count(entries);
2323 int levels = frame - frames;
2324 struct dx_entry *entries2;
2325 struct dx_node *node2;
2326 struct buffer_head *bh2;
2327
2328 if (levels && (dx_get_count(frames->entries) ==
2329 dx_get_limit(frames->entries))) {
2330 ext4_warning(sb, "Directory index full!");
2331 err = -ENOSPC;
2332 goto cleanup;
2333 }
2334 bh2 = ext4_append(handle, dir, &newblock);
2335 if (IS_ERR(bh2)) {
2336 err = PTR_ERR(bh2);
2337 goto cleanup;
2338 }
2339 node2 = (struct dx_node *)(bh2->b_data);
2340 entries2 = node2->entries;
2341 memset(&node2->fake, 0, sizeof(struct fake_dirent));
2342 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
2343 sb->s_blocksize);
2344 BUFFER_TRACE(frame->bh, "get_write_access");
2345 err = ext4_journal_get_write_access(handle, frame->bh);
2346 if (err)
2347 goto journal_error;
2348 if (levels) {
2349 unsigned icount1 = icount/2, icount2 = icount - icount1;
2350 unsigned hash2 = dx_get_hash(entries + icount1);
2351 dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
2352 icount1, icount2));
2353
2354 BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
2355 err = ext4_journal_get_write_access(handle,
2356 frames[0].bh);
2357 if (err)
2358 goto journal_error;
2359
2360 memcpy((char *) entries2, (char *) (entries + icount1),
2361 icount2 * sizeof(struct dx_entry));
2362 dx_set_count(entries, icount1);
2363 dx_set_count(entries2, icount2);
2364 dx_set_limit(entries2, dx_node_limit(dir));
2365
2366 /* Which index block gets the new entry? */
2367 if (at - entries >= icount1) {
2368 frame->at = at = at - entries - icount1 + entries2;
2369 frame->entries = entries = entries2;
2370 swap(frame->bh, bh2);
2371 }
2372 dx_insert_block(frames + 0, hash2, newblock);
2373 dxtrace(dx_show_index("node", frames[1].entries));
2374 dxtrace(dx_show_index("node",
2375 ((struct dx_node *) bh2->b_data)->entries));
2376 err = ext4_handle_dirty_dx_node(handle, dir, bh2);
2377 if (err)
2378 goto journal_error;
2379 brelse (bh2);
2380 } else {
2381 dxtrace(printk(KERN_DEBUG
2382 "Creating second level index...\n"));
2383 memcpy((char *) entries2, (char *) entries,
2384 icount * sizeof(struct dx_entry));
2385 dx_set_limit(entries2, dx_node_limit(dir));
2386
2387 /* Set up root */
2388 dx_set_count(entries, 1);
2389 dx_set_block(entries + 0, newblock);
2390 ((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels = 1;
2391
2392 /* Add new access path frame */
2393 frame = frames + 1;
2394 frame->at = at = at - entries + entries2;
2395 frame->entries = entries = entries2;
2396 frame->bh = bh2;
2397 err = ext4_journal_get_write_access(handle,
2398 frame->bh);
2399 if (err)
2400 goto journal_error;
2401 }
2402 err = ext4_handle_dirty_dx_node(handle, dir, frames[0].bh);
2403 if (err) {
2404 ext4_std_error(inode->i_sb, err);
2405 goto cleanup;
2406 }
2407 }
2408 de = do_split(handle, dir, &bh, frame, &hinfo);
2409 if (IS_ERR(de)) {
2410 err = PTR_ERR(de);
2411 goto cleanup;
2412 }
2413 err = add_dirent_to_buf(handle, dentry, inode, de, bh);
2414 goto cleanup;
2415
2416 journal_error:
2417 ext4_std_error(dir->i_sb, err);
2418 cleanup:
2419 brelse(bh);
2420 dx_release(frames);
2421 return err;
2422 }
2423
2424 /*
2425 * ext4_generic_delete_entry deletes a directory entry by merging it
2426 * with the previous entry
2427 */
2428 int ext4_generic_delete_entry(handle_t *handle,
2429 struct inode *dir,
2430 struct ext4_dir_entry_2 *de_del,
2431 struct buffer_head *bh,
2432 void *entry_buf,
2433 int buf_size,
2434 int csum_size)
2435 {
2436 struct ext4_dir_entry_2 *de, *pde;
2437 unsigned int blocksize = dir->i_sb->s_blocksize;
2438 int i;
2439
2440 i = 0;
2441 pde = NULL;
2442 de = (struct ext4_dir_entry_2 *)entry_buf;
2443 while (i < buf_size - csum_size) {
2444 if (ext4_check_dir_entry(dir, NULL, de, bh,
2445 bh->b_data, bh->b_size, i))
2446 return -EIO;
2447 if (de == de_del) {
2448 if (pde)
2449 pde->rec_len = ext4_rec_len_to_disk(
2450 ext4_rec_len_from_disk(pde->rec_len,
2451 blocksize) +
2452 ext4_rec_len_from_disk(de->rec_len,
2453 blocksize),
2454 blocksize);
2455 else
2456 de->inode = 0;
2457 dir->i_version++;
2458 return 0;
2459 }
2460 i += ext4_rec_len_from_disk(de->rec_len, blocksize);
2461 pde = de;
2462 de = ext4_next_entry(de, blocksize);
2463 }
2464 return -ENOENT;
2465 }
2466
2467 static int ext4_delete_entry(handle_t *handle,
2468 struct inode *dir,
2469 struct ext4_dir_entry_2 *de_del,
2470 struct buffer_head *bh)
2471 {
2472 int err, csum_size = 0;
2473
2474 if (ext4_has_inline_data(dir)) {
2475 int has_inline_data = 1;
2476 err = ext4_delete_inline_entry(handle, dir, de_del, bh,
2477 &has_inline_data);
2478 if (has_inline_data)
2479 return err;
2480 }
2481
2482 if (ext4_has_metadata_csum(dir->i_sb))
2483 csum_size = sizeof(struct ext4_dir_entry_tail);
2484
2485 BUFFER_TRACE(bh, "get_write_access");
2486 err = ext4_journal_get_write_access(handle, bh);
2487 if (unlikely(err))
2488 goto out;
2489
2490 err = ext4_generic_delete_entry(handle, dir, de_del,
2491 bh, bh->b_data,
2492 dir->i_sb->s_blocksize, csum_size);
2493 if (err)
2494 goto out;
2495
2496 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
2497 err = ext4_handle_dirty_dirent_node(handle, dir, bh);
2498 if (unlikely(err))
2499 goto out;
2500
2501 return 0;
2502 out:
2503 if (err != -ENOENT)
2504 ext4_std_error(dir->i_sb, err);
2505 return err;
2506 }
2507
2508 /*
2509 * DIR_NLINK feature is set if 1) nlinks > EXT4_LINK_MAX or 2) nlinks == 2,
2510 * since this indicates that nlinks count was previously 1.
2511 */
2512 static void ext4_inc_count(handle_t *handle, struct inode *inode)
2513 {
2514 inc_nlink(inode);
2515 if (is_dx(inode) && inode->i_nlink > 1) {
2516 /* limit is 16-bit i_links_count */
2517 if (inode->i_nlink >= EXT4_LINK_MAX || inode->i_nlink == 2) {
2518 set_nlink(inode, 1);
2519 EXT4_SET_RO_COMPAT_FEATURE(inode->i_sb,
2520 EXT4_FEATURE_RO_COMPAT_DIR_NLINK);
2521 }
2522 }
2523 }
2524
2525 /*
2526 * If a directory had nlink == 1, then we should let it be 1. This indicates
2527 * directory has >EXT4_LINK_MAX subdirs.
2528 */
2529 static void ext4_dec_count(handle_t *handle, struct inode *inode)
2530 {
2531 if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
2532 drop_nlink(inode);
2533 }
2534
2535
2536 static int ext4_add_nondir(handle_t *handle,
2537 struct dentry *dentry, struct inode *inode)
2538 {
2539 int err = ext4_add_entry(handle, dentry, inode);
2540 if (!err) {
2541 ext4_mark_inode_dirty(handle, inode);
2542 unlock_new_inode(inode);
2543 d_instantiate(dentry, inode);
2544 return 0;
2545 }
2546 drop_nlink(inode);
2547 unlock_new_inode(inode);
2548 iput(inode);
2549 return err;
2550 }
2551
2552 /*
2553 * By the time this is called, we already have created
2554 * the directory cache entry for the new file, but it
2555 * is so far negative - it has no inode.
2556 *
2557 * If the create succeeds, we fill in the inode information
2558 * with d_instantiate().
2559 */
2560 static int ext4_create(struct inode *dir, struct dentry *dentry, umode_t mode,
2561 bool excl)
2562 {
2563 handle_t *handle;
2564 struct inode *inode;
2565 int err, credits, retries = 0;
2566
2567 dquot_initialize(dir);
2568
2569 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2570 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2571 retry:
2572 inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
2573 NULL, EXT4_HT_DIR, credits);
2574 handle = ext4_journal_current_handle();
2575 err = PTR_ERR(inode);
2576 if (!IS_ERR(inode)) {
2577 inode->i_op = &ext4_file_inode_operations;
2578 inode->i_fop = &ext4_file_operations;
2579 ext4_set_aops(inode);
2580 err = 0;
2581 #ifdef CONFIG_EXT4_FS_ENCRYPTION
2582 if (!err && (ext4_encrypted_inode(dir) ||
2583 DUMMY_ENCRYPTION_ENABLED(EXT4_SB(dir->i_sb)))) {
2584 err = ext4_inherit_context(dir, inode);
2585 if (err) {
2586 clear_nlink(inode);
2587 unlock_new_inode(inode);
2588 iput(inode);
2589 }
2590 }
2591 #endif
2592 if (!err)
2593 err = ext4_add_nondir(handle, dentry, inode);
2594 if (!err && IS_DIRSYNC(dir))
2595 ext4_handle_sync(handle);
2596 }
2597 if (handle)
2598 ext4_journal_stop(handle);
2599 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2600 goto retry;
2601 return err;
2602 }
2603
2604 static int ext4_mknod(struct inode *dir, struct dentry *dentry,
2605 umode_t mode, dev_t rdev)
2606 {
2607 handle_t *handle;
2608 struct inode *inode;
2609 int err, credits, retries = 0;
2610
2611 if (!new_valid_dev(rdev))
2612 return -EINVAL;
2613
2614 dquot_initialize(dir);
2615
2616 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2617 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2618 retry:
2619 inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
2620 NULL, EXT4_HT_DIR, credits);
2621 handle = ext4_journal_current_handle();
2622 err = PTR_ERR(inode);
2623 if (!IS_ERR(inode)) {
2624 init_special_inode(inode, inode->i_mode, rdev);
2625 inode->i_op = &ext4_special_inode_operations;
2626 err = ext4_add_nondir(handle, dentry, inode);
2627 if (!err && IS_DIRSYNC(dir))
2628 ext4_handle_sync(handle);
2629 }
2630 if (handle)
2631 ext4_journal_stop(handle);
2632 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2633 goto retry;
2634 return err;
2635 }
2636
2637 static int ext4_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
2638 {
2639 handle_t *handle;
2640 struct inode *inode;
2641 int err, retries = 0;
2642
2643 dquot_initialize(dir);
2644
2645 retry:
2646 inode = ext4_new_inode_start_handle(dir, mode,
2647 NULL, 0, NULL,
2648 EXT4_HT_DIR,
2649 EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
2650 4 + EXT4_XATTR_TRANS_BLOCKS);
2651 handle = ext4_journal_current_handle();
2652 err = PTR_ERR(inode);
2653 if (!IS_ERR(inode)) {
2654 inode->i_op = &ext4_file_inode_operations;
2655 inode->i_fop = &ext4_file_operations;
2656 ext4_set_aops(inode);
2657 d_tmpfile(dentry, inode);
2658 err = ext4_orphan_add(handle, inode);
2659 if (err)
2660 goto err_unlock_inode;
2661 mark_inode_dirty(inode);
2662 unlock_new_inode(inode);
2663 }
2664 if (handle)
2665 ext4_journal_stop(handle);
2666 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2667 goto retry;
2668 return err;
2669 err_unlock_inode:
2670 ext4_journal_stop(handle);
2671 unlock_new_inode(inode);
2672 return err;
2673 }
2674
2675 struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
2676 struct ext4_dir_entry_2 *de,
2677 int blocksize, int csum_size,
2678 unsigned int parent_ino, int dotdot_real_len)
2679 {
2680 de->inode = cpu_to_le32(inode->i_ino);
2681 de->name_len = 1;
2682 de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
2683 blocksize);
2684 strcpy(de->name, ".");
2685 ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2686
2687 de = ext4_next_entry(de, blocksize);
2688 de->inode = cpu_to_le32(parent_ino);
2689 de->name_len = 2;
2690 if (!dotdot_real_len)
2691 de->rec_len = ext4_rec_len_to_disk(blocksize -
2692 (csum_size + EXT4_DIR_REC_LEN(1)),
2693 blocksize);
2694 else
2695 de->rec_len = ext4_rec_len_to_disk(
2696 EXT4_DIR_REC_LEN(de->name_len), blocksize);
2697 strcpy(de->name, "..");
2698 ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2699
2700 return ext4_next_entry(de, blocksize);
2701 }
2702
2703 static int ext4_init_new_dir(handle_t *handle, struct inode *dir,
2704 struct inode *inode)
2705 {
2706 struct buffer_head *dir_block = NULL;
2707 struct ext4_dir_entry_2 *de;
2708 struct ext4_dir_entry_tail *t;
2709 ext4_lblk_t block = 0;
2710 unsigned int blocksize = dir->i_sb->s_blocksize;
2711 int csum_size = 0;
2712 int err;
2713
2714 if (ext4_has_metadata_csum(dir->i_sb))
2715 csum_size = sizeof(struct ext4_dir_entry_tail);
2716
2717 if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
2718 err = ext4_try_create_inline_dir(handle, dir, inode);
2719 if (err < 0 && err != -ENOSPC)
2720 goto out;
2721 if (!err)
2722 goto out;
2723 }
2724
2725 inode->i_size = 0;
2726 dir_block = ext4_append(handle, inode, &block);
2727 if (IS_ERR(dir_block))
2728 return PTR_ERR(dir_block);
2729 de = (struct ext4_dir_entry_2 *)dir_block->b_data;
2730 ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0);
2731 set_nlink(inode, 2);
2732 if (csum_size) {
2733 t = EXT4_DIRENT_TAIL(dir_block->b_data, blocksize);
2734 initialize_dirent_tail(t, blocksize);
2735 }
2736
2737 BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
2738 err = ext4_handle_dirty_dirent_node(handle, inode, dir_block);
2739 if (err)
2740 goto out;
2741 set_buffer_verified(dir_block);
2742 out:
2743 brelse(dir_block);
2744 return err;
2745 }
2746
2747 static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
2748 {
2749 handle_t *handle;
2750 struct inode *inode;
2751 int err, credits, retries = 0;
2752
2753 if (EXT4_DIR_LINK_MAX(dir))
2754 return -EMLINK;
2755
2756 dquot_initialize(dir);
2757
2758 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2759 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2760 retry:
2761 inode = ext4_new_inode_start_handle(dir, S_IFDIR | mode,
2762 &dentry->d_name,
2763 0, NULL, EXT4_HT_DIR, credits);
2764 handle = ext4_journal_current_handle();
2765 err = PTR_ERR(inode);
2766 if (IS_ERR(inode))
2767 goto out_stop;
2768
2769 inode->i_op = &ext4_dir_inode_operations;
2770 inode->i_fop = &ext4_dir_operations;
2771 err = ext4_init_new_dir(handle, dir, inode);
2772 if (err)
2773 goto out_clear_inode;
2774 #ifdef CONFIG_EXT4_FS_ENCRYPTION
2775 if (ext4_encrypted_inode(dir) ||
2776 DUMMY_ENCRYPTION_ENABLED(EXT4_SB(dir->i_sb))) {
2777 err = ext4_inherit_context(dir, inode);
2778 if (err)
2779 goto out_clear_inode;
2780 }
2781 #endif
2782 err = ext4_mark_inode_dirty(handle, inode);
2783 if (!err)
2784 err = ext4_add_entry(handle, dentry, inode);
2785 if (err) {
2786 out_clear_inode:
2787 clear_nlink(inode);
2788 unlock_new_inode(inode);
2789 ext4_mark_inode_dirty(handle, inode);
2790 iput(inode);
2791 goto out_stop;
2792 }
2793 ext4_inc_count(handle, dir);
2794 ext4_update_dx_flag(dir);
2795 err = ext4_mark_inode_dirty(handle, dir);
2796 if (err)
2797 goto out_clear_inode;
2798 unlock_new_inode(inode);
2799 d_instantiate(dentry, inode);
2800 if (IS_DIRSYNC(dir))
2801 ext4_handle_sync(handle);
2802
2803 out_stop:
2804 if (handle)
2805 ext4_journal_stop(handle);
2806 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2807 goto retry;
2808 return err;
2809 }
2810
2811 /*
2812 * routine to check that the specified directory is empty (for rmdir)
2813 */
2814 int ext4_empty_dir(struct inode *inode)
2815 {
2816 unsigned int offset;
2817 struct buffer_head *bh;
2818 struct ext4_dir_entry_2 *de, *de1;
2819 struct super_block *sb;
2820 int err = 0;
2821
2822 if (ext4_has_inline_data(inode)) {
2823 int has_inline_data = 1;
2824
2825 err = empty_inline_dir(inode, &has_inline_data);
2826 if (has_inline_data)
2827 return err;
2828 }
2829
2830 sb = inode->i_sb;
2831 if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2)) {
2832 EXT4_ERROR_INODE(inode, "invalid size");
2833 return 1;
2834 }
2835 bh = ext4_read_dirblock(inode, 0, EITHER);
2836 if (IS_ERR(bh))
2837 return 1;
2838
2839 de = (struct ext4_dir_entry_2 *) bh->b_data;
2840 de1 = ext4_next_entry(de, sb->s_blocksize);
2841 if (le32_to_cpu(de->inode) != inode->i_ino ||
2842 !le32_to_cpu(de1->inode) ||
2843 strcmp(".", de->name) ||
2844 strcmp("..", de1->name)) {
2845 ext4_warning(inode->i_sb,
2846 "bad directory (dir #%lu) - no `.' or `..'",
2847 inode->i_ino);
2848 brelse(bh);
2849 return 1;
2850 }
2851 offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) +
2852 ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize);
2853 de = ext4_next_entry(de1, sb->s_blocksize);
2854 while (offset < inode->i_size) {
2855 if ((void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
2856 unsigned int lblock;
2857 err = 0;
2858 brelse(bh);
2859 lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb);
2860 bh = ext4_read_dirblock(inode, lblock, EITHER);
2861 if (IS_ERR(bh))
2862 return 1;
2863 de = (struct ext4_dir_entry_2 *) bh->b_data;
2864 }
2865 if (ext4_check_dir_entry(inode, NULL, de, bh,
2866 bh->b_data, bh->b_size, offset)) {
2867 de = (struct ext4_dir_entry_2 *)(bh->b_data +
2868 sb->s_blocksize);
2869 offset = (offset | (sb->s_blocksize - 1)) + 1;
2870 continue;
2871 }
2872 if (le32_to_cpu(de->inode)) {
2873 brelse(bh);
2874 return 0;
2875 }
2876 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
2877 de = ext4_next_entry(de, sb->s_blocksize);
2878 }
2879 brelse(bh);
2880 return 1;
2881 }
2882
2883 /*
2884 * ext4_orphan_add() links an unlinked or truncated inode into a list of
2885 * such inodes, starting at the superblock, in case we crash before the
2886 * file is closed/deleted, or in case the inode truncate spans multiple
2887 * transactions and the last transaction is not recovered after a crash.
2888 *
2889 * At filesystem recovery time, we walk this list deleting unlinked
2890 * inodes and truncating linked inodes in ext4_orphan_cleanup().
2891 *
2892 * Orphan list manipulation functions must be called under i_mutex unless
2893 * we are just creating the inode or deleting it.
2894 */
2895 int ext4_orphan_add(handle_t *handle, struct inode *inode)
2896 {
2897 struct super_block *sb = inode->i_sb;
2898 struct ext4_sb_info *sbi = EXT4_SB(sb);
2899 struct ext4_iloc iloc;
2900 int err = 0, rc;
2901 bool dirty = false;
2902
2903 if (!sbi->s_journal || is_bad_inode(inode))
2904 return 0;
2905
2906 WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
2907 !mutex_is_locked(&inode->i_mutex));
2908 /*
2909 * Exit early if inode already is on orphan list. This is a big speedup
2910 * since we don't have to contend on the global s_orphan_lock.
2911 */
2912 if (!list_empty(&EXT4_I(inode)->i_orphan))
2913 return 0;
2914
2915 /*
2916 * Orphan handling is only valid for files with data blocks
2917 * being truncated, or files being unlinked. Note that we either
2918 * hold i_mutex, or the inode can not be referenced from outside,
2919 * so i_nlink should not be bumped due to race
2920 */
2921 J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2922 S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
2923
2924 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2925 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2926 if (err)
2927 goto out;
2928
2929 err = ext4_reserve_inode_write(handle, inode, &iloc);
2930 if (err)
2931 goto out;
2932
2933 mutex_lock(&sbi->s_orphan_lock);
2934 /*
2935 * Due to previous errors inode may be already a part of on-disk
2936 * orphan list. If so skip on-disk list modification.
2937 */
2938 if (!NEXT_ORPHAN(inode) || NEXT_ORPHAN(inode) >
2939 (le32_to_cpu(sbi->s_es->s_inodes_count))) {
2940 /* Insert this inode at the head of the on-disk orphan list */
2941 NEXT_ORPHAN(inode) = le32_to_cpu(sbi->s_es->s_last_orphan);
2942 sbi->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
2943 dirty = true;
2944 }
2945 list_add(&EXT4_I(inode)->i_orphan, &sbi->s_orphan);
2946 mutex_unlock(&sbi->s_orphan_lock);
2947
2948 if (dirty) {
2949 err = ext4_handle_dirty_super(handle, sb);
2950 rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
2951 if (!err)
2952 err = rc;
2953 if (err) {
2954 /*
2955 * We have to remove inode from in-memory list if
2956 * addition to on disk orphan list failed. Stray orphan
2957 * list entries can cause panics at unmount time.
2958 */
2959 mutex_lock(&sbi->s_orphan_lock);
2960 list_del(&EXT4_I(inode)->i_orphan);
2961 mutex_unlock(&sbi->s_orphan_lock);
2962 }
2963 }
2964 jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
2965 jbd_debug(4, "orphan inode %lu will point to %d\n",
2966 inode->i_ino, NEXT_ORPHAN(inode));
2967 out:
2968 ext4_std_error(sb, err);
2969 return err;
2970 }
2971
2972 /*
2973 * ext4_orphan_del() removes an unlinked or truncated inode from the list
2974 * of such inodes stored on disk, because it is finally being cleaned up.
2975 */
2976 int ext4_orphan_del(handle_t *handle, struct inode *inode)
2977 {
2978 struct list_head *prev;
2979 struct ext4_inode_info *ei = EXT4_I(inode);
2980 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2981 __u32 ino_next;
2982 struct ext4_iloc iloc;
2983 int err = 0;
2984
2985 if (!sbi->s_journal && !(sbi->s_mount_state & EXT4_ORPHAN_FS))
2986 return 0;
2987
2988 WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
2989 !mutex_is_locked(&inode->i_mutex));
2990 /* Do this quick check before taking global s_orphan_lock. */
2991 if (list_empty(&ei->i_orphan))
2992 return 0;
2993
2994 if (handle) {
2995 /* Grab inode buffer early before taking global s_orphan_lock */
2996 err = ext4_reserve_inode_write(handle, inode, &iloc);
2997 }
2998
2999 mutex_lock(&sbi->s_orphan_lock);
3000 jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
3001
3002 prev = ei->i_orphan.prev;
3003 list_del_init(&ei->i_orphan);
3004
3005 /* If we're on an error path, we may not have a valid
3006 * transaction handle with which to update the orphan list on
3007 * disk, but we still need to remove the inode from the linked
3008 * list in memory. */
3009 if (!handle || err) {
3010 mutex_unlock(&sbi->s_orphan_lock);
3011 goto out_err;
3012 }
3013
3014 ino_next = NEXT_ORPHAN(inode);
3015 if (prev == &sbi->s_orphan) {
3016 jbd_debug(4, "superblock will point to %u\n", ino_next);
3017 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
3018 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
3019 if (err) {
3020 mutex_unlock(&sbi->s_orphan_lock);
3021 goto out_brelse;
3022 }
3023 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
3024 mutex_unlock(&sbi->s_orphan_lock);
3025 err = ext4_handle_dirty_super(handle, inode->i_sb);
3026 } else {
3027 struct ext4_iloc iloc2;
3028 struct inode *i_prev =
3029 &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
3030
3031 jbd_debug(4, "orphan inode %lu will point to %u\n",
3032 i_prev->i_ino, ino_next);
3033 err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
3034 if (err) {
3035 mutex_unlock(&sbi->s_orphan_lock);
3036 goto out_brelse;
3037 }
3038 NEXT_ORPHAN(i_prev) = ino_next;
3039 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
3040 mutex_unlock(&sbi->s_orphan_lock);
3041 }
3042 if (err)
3043 goto out_brelse;
3044 NEXT_ORPHAN(inode) = 0;
3045 err = ext4_mark_iloc_dirty(handle, inode, &iloc);
3046 out_err:
3047 ext4_std_error(inode->i_sb, err);
3048 return err;
3049
3050 out_brelse:
3051 brelse(iloc.bh);
3052 goto out_err;
3053 }
3054
3055 static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
3056 {
3057 int retval;
3058 struct inode *inode;
3059 struct buffer_head *bh;
3060 struct ext4_dir_entry_2 *de;
3061 handle_t *handle = NULL;
3062
3063 /* Initialize quotas before so that eventual writes go in
3064 * separate transaction */
3065 dquot_initialize(dir);
3066 dquot_initialize(d_inode(dentry));
3067
3068 retval = -ENOENT;
3069 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
3070 if (IS_ERR(bh))
3071 return PTR_ERR(bh);
3072 if (!bh)
3073 goto end_rmdir;
3074
3075 inode = d_inode(dentry);
3076
3077 retval = -EIO;
3078 if (le32_to_cpu(de->inode) != inode->i_ino)
3079 goto end_rmdir;
3080
3081 retval = -ENOTEMPTY;
3082 if (!ext4_empty_dir(inode))
3083 goto end_rmdir;
3084
3085 handle = ext4_journal_start(dir, EXT4_HT_DIR,
3086 EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
3087 if (IS_ERR(handle)) {
3088 retval = PTR_ERR(handle);
3089 handle = NULL;
3090 goto end_rmdir;
3091 }
3092
3093 if (IS_DIRSYNC(dir))
3094 ext4_handle_sync(handle);
3095
3096 retval = ext4_delete_entry(handle, dir, de, bh);
3097 if (retval)
3098 goto end_rmdir;
3099 if (!EXT4_DIR_LINK_EMPTY(inode))
3100 ext4_warning(inode->i_sb,
3101 "empty directory has too many links (%d)",
3102 inode->i_nlink);
3103 inode->i_version++;
3104 clear_nlink(inode);
3105 /* There's no need to set i_disksize: the fact that i_nlink is
3106 * zero will ensure that the right thing happens during any
3107 * recovery. */
3108 inode->i_size = 0;
3109 ext4_orphan_add(handle, inode);
3110 inode->i_ctime = dir->i_ctime = dir->i_mtime = ext4_current_time(inode);
3111 ext4_mark_inode_dirty(handle, inode);
3112 ext4_dec_count(handle, dir);
3113 ext4_update_dx_flag(dir);
3114 ext4_mark_inode_dirty(handle, dir);
3115
3116 end_rmdir:
3117 brelse(bh);
3118 if (handle)
3119 ext4_journal_stop(handle);
3120 return retval;
3121 }
3122
3123 static int ext4_unlink(struct inode *dir, struct dentry *dentry)
3124 {
3125 int retval;
3126 struct inode *inode;
3127 struct buffer_head *bh;
3128 struct ext4_dir_entry_2 *de;
3129 handle_t *handle = NULL;
3130
3131 trace_ext4_unlink_enter(dir, dentry);
3132 /* Initialize quotas before so that eventual writes go
3133 * in separate transaction */
3134 dquot_initialize(dir);
3135 dquot_initialize(d_inode(dentry));
3136
3137 retval = -ENOENT;
3138 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
3139 if (IS_ERR(bh))
3140 return PTR_ERR(bh);
3141 if (!bh)
3142 goto end_unlink;
3143
3144 inode = d_inode(dentry);
3145
3146 retval = -EIO;
3147 if (le32_to_cpu(de->inode) != inode->i_ino)
3148 goto end_unlink;
3149
3150 handle = ext4_journal_start(dir, EXT4_HT_DIR,
3151 EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
3152 if (IS_ERR(handle)) {
3153 retval = PTR_ERR(handle);
3154 handle = NULL;
3155 goto end_unlink;
3156 }
3157
3158 if (IS_DIRSYNC(dir))
3159 ext4_handle_sync(handle);
3160
3161 if (!inode->i_nlink) {
3162 ext4_warning(inode->i_sb,
3163 "Deleting nonexistent file (%lu), %d",
3164 inode->i_ino, inode->i_nlink);
3165 set_nlink(inode, 1);
3166 }
3167 retval = ext4_delete_entry(handle, dir, de, bh);
3168 if (retval)
3169 goto end_unlink;
3170 dir->i_ctime = dir->i_mtime = ext4_current_time(dir);
3171 ext4_update_dx_flag(dir);
3172 ext4_mark_inode_dirty(handle, dir);
3173 drop_nlink(inode);
3174 if (!inode->i_nlink)
3175 ext4_orphan_add(handle, inode);
3176 inode->i_ctime = ext4_current_time(inode);
3177 ext4_mark_inode_dirty(handle, inode);
3178
3179 end_unlink:
3180 brelse(bh);
3181 if (handle)
3182 ext4_journal_stop(handle);
3183 trace_ext4_unlink_exit(dentry, retval);
3184 return retval;
3185 }
3186
3187 static int ext4_symlink(struct inode *dir,
3188 struct dentry *dentry, const char *symname)
3189 {
3190 handle_t *handle;
3191 struct inode *inode;
3192 int err, len = strlen(symname);
3193 int credits;
3194 bool encryption_required;
3195 struct ext4_str disk_link;
3196 struct ext4_encrypted_symlink_data *sd = NULL;
3197
3198 disk_link.len = len + 1;
3199 disk_link.name = (char *) symname;
3200
3201 encryption_required = (ext4_encrypted_inode(dir) ||
3202 DUMMY_ENCRYPTION_ENABLED(EXT4_SB(dir->i_sb)));
3203 if (encryption_required)
3204 disk_link.len = encrypted_symlink_data_len(len) + 1;
3205 if (disk_link.len > dir->i_sb->s_blocksize)
3206 return -ENAMETOOLONG;
3207
3208 dquot_initialize(dir);
3209
3210 if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
3211 /*
3212 * For non-fast symlinks, we just allocate inode and put it on
3213 * orphan list in the first transaction => we need bitmap,
3214 * group descriptor, sb, inode block, quota blocks, and
3215 * possibly selinux xattr blocks.
3216 */
3217 credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
3218 EXT4_XATTR_TRANS_BLOCKS;
3219 } else {
3220 /*
3221 * Fast symlink. We have to add entry to directory
3222 * (EXT4_DATA_TRANS_BLOCKS + EXT4_INDEX_EXTRA_TRANS_BLOCKS),
3223 * allocate new inode (bitmap, group descriptor, inode block,
3224 * quota blocks, sb is already counted in previous macros).
3225 */
3226 credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3227 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3;
3228 }
3229
3230 inode = ext4_new_inode_start_handle(dir, S_IFLNK|S_IRWXUGO,
3231 &dentry->d_name, 0, NULL,
3232 EXT4_HT_DIR, credits);
3233 handle = ext4_journal_current_handle();
3234 if (IS_ERR(inode)) {
3235 if (handle)
3236 ext4_journal_stop(handle);
3237 return PTR_ERR(inode);
3238 }
3239
3240 if (encryption_required) {
3241 struct ext4_fname_crypto_ctx *ctx = NULL;
3242 struct qstr istr;
3243 struct ext4_str ostr;
3244
3245 sd = kzalloc(disk_link.len, GFP_NOFS);
3246 if (!sd) {
3247 err = -ENOMEM;
3248 goto err_drop_inode;
3249 }
3250 err = ext4_inherit_context(dir, inode);
3251 if (err)
3252 goto err_drop_inode;
3253 ctx = ext4_get_fname_crypto_ctx(inode,
3254 inode->i_sb->s_blocksize);
3255 if (IS_ERR_OR_NULL(ctx)) {
3256 /* We just set the policy, so ctx should not be NULL */
3257 err = (ctx == NULL) ? -EIO : PTR_ERR(ctx);
3258 goto err_drop_inode;
3259 }
3260 istr.name = (const unsigned char *) symname;
3261 istr.len = len;
3262 ostr.name = sd->encrypted_path;
3263 err = ext4_fname_usr_to_disk(ctx, &istr, &ostr);
3264 ext4_put_fname_crypto_ctx(&ctx);
3265 if (err < 0)
3266 goto err_drop_inode;
3267 sd->len = cpu_to_le16(ostr.len);
3268 disk_link.name = (char *) sd;
3269 }
3270
3271 if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
3272 inode->i_op = &ext4_symlink_inode_operations;
3273 ext4_set_aops(inode);
3274 /*
3275 * We cannot call page_symlink() with transaction started
3276 * because it calls into ext4_write_begin() which can wait
3277 * for transaction commit if we are running out of space
3278 * and thus we deadlock. So we have to stop transaction now
3279 * and restart it when symlink contents is written.
3280 *
3281 * To keep fs consistent in case of crash, we have to put inode
3282 * to orphan list in the mean time.
3283 */
3284 drop_nlink(inode);
3285 err = ext4_orphan_add(handle, inode);
3286 ext4_journal_stop(handle);
3287 handle = NULL;
3288 if (err)
3289 goto err_drop_inode;
3290 err = __page_symlink(inode, disk_link.name, disk_link.len, 1);
3291 if (err)
3292 goto err_drop_inode;
3293 /*
3294 * Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS
3295 * + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified
3296 */
3297 handle = ext4_journal_start(dir, EXT4_HT_DIR,
3298 EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3299 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1);
3300 if (IS_ERR(handle)) {
3301 err = PTR_ERR(handle);
3302 handle = NULL;
3303 goto err_drop_inode;
3304 }
3305 set_nlink(inode, 1);
3306 err = ext4_orphan_del(handle, inode);
3307 if (err)
3308 goto err_drop_inode;
3309 } else {
3310 /* clear the extent format for fast symlink */
3311 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
3312 inode->i_op = encryption_required ?
3313 &ext4_symlink_inode_operations :
3314 &ext4_fast_symlink_inode_operations;
3315 memcpy((char *)&EXT4_I(inode)->i_data, disk_link.name,
3316 disk_link.len);
3317 inode->i_size = disk_link.len - 1;
3318 }
3319 EXT4_I(inode)->i_disksize = inode->i_size;
3320 err = ext4_add_nondir(handle, dentry, inode);
3321 if (!err && IS_DIRSYNC(dir))
3322 ext4_handle_sync(handle);
3323
3324 if (handle)
3325 ext4_journal_stop(handle);
3326 kfree(sd);
3327 return err;
3328 err_drop_inode:
3329 if (handle)
3330 ext4_journal_stop(handle);
3331 kfree(sd);
3332 clear_nlink(inode);
3333 unlock_new_inode(inode);
3334 iput(inode);
3335 return err;
3336 }
3337
3338 static int ext4_link(struct dentry *old_dentry,
3339 struct inode *dir, struct dentry *dentry)
3340 {
3341 handle_t *handle;
3342 struct inode *inode = d_inode(old_dentry);
3343 int err, retries = 0;
3344
3345 if (inode->i_nlink >= EXT4_LINK_MAX)
3346 return -EMLINK;
3347 if (ext4_encrypted_inode(dir) &&
3348 !ext4_is_child_context_consistent_with_parent(dir, inode))
3349 return -EPERM;
3350 dquot_initialize(dir);
3351
3352 retry:
3353 handle = ext4_journal_start(dir, EXT4_HT_DIR,
3354 (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3355 EXT4_INDEX_EXTRA_TRANS_BLOCKS) + 1);
3356 if (IS_ERR(handle))
3357 return PTR_ERR(handle);
3358
3359 if (IS_DIRSYNC(dir))
3360 ext4_handle_sync(handle);
3361
3362 inode->i_ctime = ext4_current_time(inode);
3363 ext4_inc_count(handle, inode);
3364 ihold(inode);
3365
3366 err = ext4_add_entry(handle, dentry, inode);
3367 if (!err) {
3368 ext4_mark_inode_dirty(handle, inode);
3369 /* this can happen only for tmpfile being
3370 * linked the first time
3371 */
3372 if (inode->i_nlink == 1)
3373 ext4_orphan_del(handle, inode);
3374 d_instantiate(dentry, inode);
3375 } else {
3376 drop_nlink(inode);
3377 iput(inode);
3378 }
3379 ext4_journal_stop(handle);
3380 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
3381 goto retry;
3382 return err;
3383 }
3384
3385
3386 /*
3387 * Try to find buffer head where contains the parent block.
3388 * It should be the inode block if it is inlined or the 1st block
3389 * if it is a normal dir.
3390 */
3391 static struct buffer_head *ext4_get_first_dir_block(handle_t *handle,
3392 struct inode *inode,
3393 int *retval,
3394 struct ext4_dir_entry_2 **parent_de,
3395 int *inlined)
3396 {
3397 struct buffer_head *bh;
3398
3399 if (!ext4_has_inline_data(inode)) {
3400 bh = ext4_read_dirblock(inode, 0, EITHER);
3401 if (IS_ERR(bh)) {
3402 *retval = PTR_ERR(bh);
3403 return NULL;
3404 }
3405 *parent_de = ext4_next_entry(
3406 (struct ext4_dir_entry_2 *)bh->b_data,
3407 inode->i_sb->s_blocksize);
3408 return bh;
3409 }
3410
3411 *inlined = 1;
3412 return ext4_get_first_inline_block(inode, parent_de, retval);
3413 }
3414
3415 struct ext4_renament {
3416 struct inode *dir;
3417 struct dentry *dentry;
3418 struct inode *inode;
3419 bool is_dir;
3420 int dir_nlink_delta;
3421
3422 /* entry for "dentry" */
3423 struct buffer_head *bh;
3424 struct ext4_dir_entry_2 *de;
3425 int inlined;
3426
3427 /* entry for ".." in inode if it's a directory */
3428 struct buffer_head *dir_bh;
3429 struct ext4_dir_entry_2 *parent_de;
3430 int dir_inlined;
3431 };
3432
3433 static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent)
3434 {
3435 int retval;
3436
3437 ent->dir_bh = ext4_get_first_dir_block(handle, ent->inode,
3438 &retval, &ent->parent_de,
3439 &ent->dir_inlined);
3440 if (!ent->dir_bh)
3441 return retval;
3442 if (le32_to_cpu(ent->parent_de->inode) != ent->dir->i_ino)
3443 return -EIO;
3444 BUFFER_TRACE(ent->dir_bh, "get_write_access");
3445 return ext4_journal_get_write_access(handle, ent->dir_bh);
3446 }
3447
3448 static int ext4_rename_dir_finish(handle_t *handle, struct ext4_renament *ent,
3449 unsigned dir_ino)
3450 {
3451 int retval;
3452
3453 ent->parent_de->inode = cpu_to_le32(dir_ino);
3454 BUFFER_TRACE(ent->dir_bh, "call ext4_handle_dirty_metadata");
3455 if (!ent->dir_inlined) {
3456 if (is_dx(ent->inode)) {
3457 retval = ext4_handle_dirty_dx_node(handle,
3458 ent->inode,
3459 ent->dir_bh);
3460 } else {
3461 retval = ext4_handle_dirty_dirent_node(handle,
3462 ent->inode,
3463 ent->dir_bh);
3464 }
3465 } else {
3466 retval = ext4_mark_inode_dirty(handle, ent->inode);
3467 }
3468 if (retval) {
3469 ext4_std_error(ent->dir->i_sb, retval);
3470 return retval;
3471 }
3472 return 0;
3473 }
3474
3475 static int ext4_setent(handle_t *handle, struct ext4_renament *ent,
3476 unsigned ino, unsigned file_type)
3477 {
3478 int retval;
3479
3480 BUFFER_TRACE(ent->bh, "get write access");
3481 retval = ext4_journal_get_write_access(handle, ent->bh);
3482 if (retval)
3483 return retval;
3484 ent->de->inode = cpu_to_le32(ino);
3485 if (EXT4_HAS_INCOMPAT_FEATURE(ent->dir->i_sb,
3486 EXT4_FEATURE_INCOMPAT_FILETYPE))
3487 ent->de->file_type = file_type;
3488 ent->dir->i_version++;
3489 ent->dir->i_ctime = ent->dir->i_mtime =
3490 ext4_current_time(ent->dir);
3491 ext4_mark_inode_dirty(handle, ent->dir);
3492 BUFFER_TRACE(ent->bh, "call ext4_handle_dirty_metadata");
3493 if (!ent->inlined) {
3494 retval = ext4_handle_dirty_dirent_node(handle,
3495 ent->dir, ent->bh);
3496 if (unlikely(retval)) {
3497 ext4_std_error(ent->dir->i_sb, retval);
3498 return retval;
3499 }
3500 }
3501 brelse(ent->bh);
3502 ent->bh = NULL;
3503
3504 return 0;
3505 }
3506
3507 static int ext4_find_delete_entry(handle_t *handle, struct inode *dir,
3508 const struct qstr *d_name)
3509 {
3510 int retval = -ENOENT;
3511 struct buffer_head *bh;
3512 struct ext4_dir_entry_2 *de;
3513
3514 bh = ext4_find_entry(dir, d_name, &de, NULL);
3515 if (IS_ERR(bh))
3516 return PTR_ERR(bh);
3517 if (bh) {
3518 retval = ext4_delete_entry(handle, dir, de, bh);
3519 brelse(bh);
3520 }
3521 return retval;
3522 }
3523
3524 static void ext4_rename_delete(handle_t *handle, struct ext4_renament *ent,
3525 int force_reread)
3526 {
3527 int retval;
3528 /*
3529 * ent->de could have moved from under us during htree split, so make
3530 * sure that we are deleting the right entry. We might also be pointing
3531 * to a stale entry in the unused part of ent->bh so just checking inum
3532 * and the name isn't enough.
3533 */
3534 if (le32_to_cpu(ent->de->inode) != ent->inode->i_ino ||
3535 ent->de->name_len != ent->dentry->d_name.len ||
3536 strncmp(ent->de->name, ent->dentry->d_name.name,
3537 ent->de->name_len) ||
3538 force_reread) {
3539 retval = ext4_find_delete_entry(handle, ent->dir,
3540 &ent->dentry->d_name);
3541 } else {
3542 retval = ext4_delete_entry(handle, ent->dir, ent->de, ent->bh);
3543 if (retval == -ENOENT) {
3544 retval = ext4_find_delete_entry(handle, ent->dir,
3545 &ent->dentry->d_name);
3546 }
3547 }
3548
3549 if (retval) {
3550 ext4_warning(ent->dir->i_sb,
3551 "Deleting old file (%lu), %d, error=%d",
3552 ent->dir->i_ino, ent->dir->i_nlink, retval);
3553 }
3554 }
3555
3556 static void ext4_update_dir_count(handle_t *handle, struct ext4_renament *ent)
3557 {
3558 if (ent->dir_nlink_delta) {
3559 if (ent->dir_nlink_delta == -1)
3560 ext4_dec_count(handle, ent->dir);
3561 else
3562 ext4_inc_count(handle, ent->dir);
3563 ext4_mark_inode_dirty(handle, ent->dir);
3564 }
3565 }
3566
3567 static struct inode *ext4_whiteout_for_rename(struct ext4_renament *ent,
3568 int credits, handle_t **h)
3569 {
3570 struct inode *wh;
3571 handle_t *handle;
3572 int retries = 0;
3573
3574 /*
3575 * for inode block, sb block, group summaries,
3576 * and inode bitmap
3577 */
3578 credits += (EXT4_MAXQUOTAS_TRANS_BLOCKS(ent->dir->i_sb) +
3579 EXT4_XATTR_TRANS_BLOCKS + 4);
3580 retry:
3581 wh = ext4_new_inode_start_handle(ent->dir, S_IFCHR | WHITEOUT_MODE,
3582 &ent->dentry->d_name, 0, NULL,
3583 EXT4_HT_DIR, credits);
3584
3585 handle = ext4_journal_current_handle();
3586 if (IS_ERR(wh)) {
3587 if (handle)
3588 ext4_journal_stop(handle);
3589 if (PTR_ERR(wh) == -ENOSPC &&
3590 ext4_should_retry_alloc(ent->dir->i_sb, &retries))
3591 goto retry;
3592 } else {
3593 *h = handle;
3594 init_special_inode(wh, wh->i_mode, WHITEOUT_DEV);
3595 wh->i_op = &ext4_special_inode_operations;
3596 }
3597 return wh;
3598 }
3599
3600 /*
3601 * Anybody can rename anything with this: the permission checks are left to the
3602 * higher-level routines.
3603 *
3604 * n.b. old_{dentry,inode) refers to the source dentry/inode
3605 * while new_{dentry,inode) refers to the destination dentry/inode
3606 * This comes from rename(const char *oldpath, const char *newpath)
3607 */
3608 static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
3609 struct inode *new_dir, struct dentry *new_dentry,
3610 unsigned int flags)
3611 {
3612 handle_t *handle = NULL;
3613 struct ext4_renament old = {
3614 .dir = old_dir,
3615 .dentry = old_dentry,
3616 .inode = d_inode(old_dentry),
3617 };
3618 struct ext4_renament new = {
3619 .dir = new_dir,
3620 .dentry = new_dentry,
3621 .inode = d_inode(new_dentry),
3622 };
3623 int force_reread;
3624 int retval;
3625 struct inode *whiteout = NULL;
3626 int credits;
3627 u8 old_file_type;
3628
3629 dquot_initialize(old.dir);
3630 dquot_initialize(new.dir);
3631
3632 /* Initialize quotas before so that eventual writes go
3633 * in separate transaction */
3634 if (new.inode)
3635 dquot_initialize(new.inode);
3636
3637 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, NULL);
3638 if (IS_ERR(old.bh))
3639 return PTR_ERR(old.bh);
3640 /*
3641 * Check for inode number is _not_ due to possible IO errors.
3642 * We might rmdir the source, keep it as pwd of some process
3643 * and merrily kill the link to whatever was created under the
3644 * same name. Goodbye sticky bit ;-<
3645 */
3646 retval = -ENOENT;
3647 if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3648 goto end_rename;
3649
3650 if ((old.dir != new.dir) &&
3651 ext4_encrypted_inode(new.dir) &&
3652 !ext4_is_child_context_consistent_with_parent(new.dir,
3653 old.inode)) {
3654 retval = -EPERM;
3655 goto end_rename;
3656 }
3657
3658 new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
3659 &new.de, &new.inlined);
3660 if (IS_ERR(new.bh)) {
3661 retval = PTR_ERR(new.bh);
3662 new.bh = NULL;
3663 goto end_rename;
3664 }
3665 if (new.bh) {
3666 if (!new.inode) {
3667 brelse(new.bh);
3668 new.bh = NULL;
3669 }
3670 }
3671 if (new.inode && !test_opt(new.dir->i_sb, NO_AUTO_DA_ALLOC))
3672 ext4_alloc_da_blocks(old.inode);
3673
3674 credits = (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3675 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
3676 if (!(flags & RENAME_WHITEOUT)) {
3677 handle = ext4_journal_start(old.dir, EXT4_HT_DIR, credits);
3678 if (IS_ERR(handle)) {
3679 retval = PTR_ERR(handle);
3680 handle = NULL;
3681 goto end_rename;
3682 }
3683 } else {
3684 whiteout = ext4_whiteout_for_rename(&old, credits, &handle);
3685 if (IS_ERR(whiteout)) {
3686 retval = PTR_ERR(whiteout);
3687 whiteout = NULL;
3688 goto end_rename;
3689 }
3690 }
3691
3692 if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3693 ext4_handle_sync(handle);
3694
3695 if (S_ISDIR(old.inode->i_mode)) {
3696 if (new.inode) {
3697 retval = -ENOTEMPTY;
3698 if (!ext4_empty_dir(new.inode))
3699 goto end_rename;
3700 } else {
3701 retval = -EMLINK;
3702 if (new.dir != old.dir && EXT4_DIR_LINK_MAX(new.dir))
3703 goto end_rename;
3704 }
3705 retval = ext4_rename_dir_prepare(handle, &old);
3706 if (retval)
3707 goto end_rename;
3708 }
3709 /*
3710 * If we're renaming a file within an inline_data dir and adding or
3711 * setting the new dirent causes a conversion from inline_data to
3712 * extents/blockmap, we need to force the dirent delete code to
3713 * re-read the directory, or else we end up trying to delete a dirent
3714 * from what is now the extent tree root (or a block map).
3715 */
3716 force_reread = (new.dir->i_ino == old.dir->i_ino &&
3717 ext4_test_inode_flag(new.dir, EXT4_INODE_INLINE_DATA));
3718
3719 old_file_type = old.de->file_type;
3720 if (whiteout) {
3721 /*
3722 * Do this before adding a new entry, so the old entry is sure
3723 * to be still pointing to the valid old entry.
3724 */
3725 retval = ext4_setent(handle, &old, whiteout->i_ino,
3726 EXT4_FT_CHRDEV);
3727 if (retval)
3728 goto end_rename;
3729 ext4_mark_inode_dirty(handle, whiteout);
3730 }
3731 if (!new.bh) {
3732 retval = ext4_add_entry(handle, new.dentry, old.inode);
3733 if (retval)
3734 goto end_rename;
3735 } else {
3736 retval = ext4_setent(handle, &new,
3737 old.inode->i_ino, old_file_type);
3738 if (retval)
3739 goto end_rename;
3740 }
3741 if (force_reread)
3742 force_reread = !ext4_test_inode_flag(new.dir,
3743 EXT4_INODE_INLINE_DATA);
3744
3745 /*
3746 * Like most other Unix systems, set the ctime for inodes on a
3747 * rename.
3748 */
3749 old.inode->i_ctime = ext4_current_time(old.inode);
3750 ext4_mark_inode_dirty(handle, old.inode);
3751
3752 if (!whiteout) {
3753 /*
3754 * ok, that's it
3755 */
3756 ext4_rename_delete(handle, &old, force_reread);
3757 }
3758
3759 if (new.inode) {
3760 ext4_dec_count(handle, new.inode);
3761 new.inode->i_ctime = ext4_current_time(new.inode);
3762 }
3763 old.dir->i_ctime = old.dir->i_mtime = ext4_current_time(old.dir);
3764 ext4_update_dx_flag(old.dir);
3765 if (old.dir_bh) {
3766 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
3767 if (retval)
3768 goto end_rename;
3769
3770 ext4_dec_count(handle, old.dir);
3771 if (new.inode) {
3772 /* checked ext4_empty_dir above, can't have another
3773 * parent, ext4_dec_count() won't work for many-linked
3774 * dirs */
3775 clear_nlink(new.inode);
3776 } else {
3777 ext4_inc_count(handle, new.dir);
3778 ext4_update_dx_flag(new.dir);
3779 ext4_mark_inode_dirty(handle, new.dir);
3780 }
3781 }
3782 ext4_mark_inode_dirty(handle, old.dir);
3783 if (new.inode) {
3784 ext4_mark_inode_dirty(handle, new.inode);
3785 if (!new.inode->i_nlink)
3786 ext4_orphan_add(handle, new.inode);
3787 }
3788 retval = 0;
3789
3790 end_rename:
3791 brelse(old.dir_bh);
3792 brelse(old.bh);
3793 brelse(new.bh);
3794 if (whiteout) {
3795 if (retval)
3796 drop_nlink(whiteout);
3797 unlock_new_inode(whiteout);
3798 iput(whiteout);
3799 }
3800 if (handle)
3801 ext4_journal_stop(handle);
3802 return retval;
3803 }
3804
3805 static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
3806 struct inode *new_dir, struct dentry *new_dentry)
3807 {
3808 handle_t *handle = NULL;
3809 struct ext4_renament old = {
3810 .dir = old_dir,
3811 .dentry = old_dentry,
3812 .inode = d_inode(old_dentry),
3813 };
3814 struct ext4_renament new = {
3815 .dir = new_dir,
3816 .dentry = new_dentry,
3817 .inode = d_inode(new_dentry),
3818 };
3819 u8 new_file_type;
3820 int retval;
3821
3822 dquot_initialize(old.dir);
3823 dquot_initialize(new.dir);
3824
3825 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name,
3826 &old.de, &old.inlined);
3827 if (IS_ERR(old.bh))
3828 return PTR_ERR(old.bh);
3829 /*
3830 * Check for inode number is _not_ due to possible IO errors.
3831 * We might rmdir the source, keep it as pwd of some process
3832 * and merrily kill the link to whatever was created under the
3833 * same name. Goodbye sticky bit ;-<
3834 */
3835 retval = -ENOENT;
3836 if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3837 goto end_rename;
3838
3839 new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
3840 &new.de, &new.inlined);
3841 if (IS_ERR(new.bh)) {
3842 retval = PTR_ERR(new.bh);
3843 new.bh = NULL;
3844 goto end_rename;
3845 }
3846
3847 /* RENAME_EXCHANGE case: old *and* new must both exist */
3848 if (!new.bh || le32_to_cpu(new.de->inode) != new.inode->i_ino)
3849 goto end_rename;
3850
3851 handle = ext4_journal_start(old.dir, EXT4_HT_DIR,
3852 (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3853 2 * EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2));
3854 if (IS_ERR(handle)) {
3855 retval = PTR_ERR(handle);
3856 handle = NULL;
3857 goto end_rename;
3858 }
3859
3860 if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3861 ext4_handle_sync(handle);
3862
3863 if (S_ISDIR(old.inode->i_mode)) {
3864 old.is_dir = true;
3865 retval = ext4_rename_dir_prepare(handle, &old);
3866 if (retval)
3867 goto end_rename;
3868 }
3869 if (S_ISDIR(new.inode->i_mode)) {
3870 new.is_dir = true;
3871 retval = ext4_rename_dir_prepare(handle, &new);
3872 if (retval)
3873 goto end_rename;
3874 }
3875
3876 /*
3877 * Other than the special case of overwriting a directory, parents'
3878 * nlink only needs to be modified if this is a cross directory rename.
3879 */
3880 if (old.dir != new.dir && old.is_dir != new.is_dir) {
3881 old.dir_nlink_delta = old.is_dir ? -1 : 1;
3882 new.dir_nlink_delta = -old.dir_nlink_delta;
3883 retval = -EMLINK;
3884 if ((old.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(old.dir)) ||
3885 (new.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(new.dir)))
3886 goto end_rename;
3887 }
3888
3889 new_file_type = new.de->file_type;
3890 retval = ext4_setent(handle, &new, old.inode->i_ino, old.de->file_type);
3891 if (retval)
3892 goto end_rename;
3893
3894 retval = ext4_setent(handle, &old, new.inode->i_ino, new_file_type);
3895 if (retval)
3896 goto end_rename;
3897
3898 /*
3899 * Like most other Unix systems, set the ctime for inodes on a
3900 * rename.
3901 */
3902 old.inode->i_ctime = ext4_current_time(old.inode);
3903 new.inode->i_ctime = ext4_current_time(new.inode);
3904 ext4_mark_inode_dirty(handle, old.inode);
3905 ext4_mark_inode_dirty(handle, new.inode);
3906
3907 if (old.dir_bh) {
3908 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
3909 if (retval)
3910 goto end_rename;
3911 }
3912 if (new.dir_bh) {
3913 retval = ext4_rename_dir_finish(handle, &new, old.dir->i_ino);
3914 if (retval)
3915 goto end_rename;
3916 }
3917 ext4_update_dir_count(handle, &old);
3918 ext4_update_dir_count(handle, &new);
3919 retval = 0;
3920
3921 end_rename:
3922 brelse(old.dir_bh);
3923 brelse(new.dir_bh);
3924 brelse(old.bh);
3925 brelse(new.bh);
3926 if (handle)
3927 ext4_journal_stop(handle);
3928 return retval;
3929 }
3930
3931 static int ext4_rename2(struct inode *old_dir, struct dentry *old_dentry,
3932 struct inode *new_dir, struct dentry *new_dentry,
3933 unsigned int flags)
3934 {
3935 if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
3936 return -EINVAL;
3937
3938 if (flags & RENAME_EXCHANGE) {
3939 return ext4_cross_rename(old_dir, old_dentry,
3940 new_dir, new_dentry);
3941 }
3942
3943 return ext4_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
3944 }
3945
3946 /*
3947 * directories can handle most operations...
3948 */
3949 const struct inode_operations ext4_dir_inode_operations = {
3950 .create = ext4_create,
3951 .lookup = ext4_lookup,
3952 .link = ext4_link,
3953 .unlink = ext4_unlink,
3954 .symlink = ext4_symlink,
3955 .mkdir = ext4_mkdir,
3956 .rmdir = ext4_rmdir,
3957 .mknod = ext4_mknod,
3958 .tmpfile = ext4_tmpfile,
3959 .rename2 = ext4_rename2,
3960 .setattr = ext4_setattr,
3961 .setxattr = generic_setxattr,
3962 .getxattr = generic_getxattr,
3963 .listxattr = ext4_listxattr,
3964 .removexattr = generic_removexattr,
3965 .get_acl = ext4_get_acl,
3966 .set_acl = ext4_set_acl,
3967 .fiemap = ext4_fiemap,
3968 };
3969
3970 const struct inode_operations ext4_special_inode_operations = {
3971 .setattr = ext4_setattr,
3972 .setxattr = generic_setxattr,
3973 .getxattr = generic_getxattr,
3974 .listxattr = ext4_listxattr,
3975 .removexattr = generic_removexattr,
3976 .get_acl = ext4_get_acl,
3977 .set_acl = ext4_set_acl,
3978 };
Linux kernel - Deliverables
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