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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
50static struct buffer_head *ext4_append(handle_t *handle,
51 struct inode *inode,
52 ext4_lblk_t *block)
53{
54 struct buffer_head *bh;
55 int err;
56
57 if (unlikely(EXT4_SB(inode->i_sb)->s_max_dir_size_kb &&
58 ((inode->i_size >> 10) >=
59 EXT4_SB(inode->i_sb)->s_max_dir_size_kb)))
60 return ERR_PTR(-ENOSPC);
61
62 *block = inode->i_size >> inode->i_sb->s_blocksize_bits;
63
64 bh = ext4_bread(handle, inode, *block, EXT4_GET_BLOCKS_CREATE);
65 if (IS_ERR(bh))
66 return bh;
67 inode->i_size += inode->i_sb->s_blocksize;
68 EXT4_I(inode)->i_disksize = inode->i_size;
69 BUFFER_TRACE(bh, "get_write_access");
70 err = ext4_journal_get_write_access(handle, bh);
71 if (err) {
72 brelse(bh);
73 ext4_std_error(inode->i_sb, err);
74 return ERR_PTR(err);
75 }
76 return bh;
77}
78
79static int ext4_dx_csum_verify(struct inode *inode,
80 struct ext4_dir_entry *dirent);
81
82typedef enum {
83 EITHER, INDEX, DIRENT
84} dirblock_type_t;
85
86#define ext4_read_dirblock(inode, block, type) \
87 __ext4_read_dirblock((inode), (block), (type), __func__, __LINE__)
88
89static struct buffer_head *__ext4_read_dirblock(struct inode *inode,
90 ext4_lblk_t block,
91 dirblock_type_t type,
92 const char *func,
93 unsigned int line)
94{
95 struct buffer_head *bh;
96 struct ext4_dir_entry *dirent;
97 int is_dx_block = 0;
98
99 bh = ext4_bread(NULL, inode, block, 0);
100 if (IS_ERR(bh)) {
101 __ext4_warning(inode->i_sb, func, line,
102 "inode #%lu: lblock %lu: comm %s: "
103 "error %ld reading directory block",
104 inode->i_ino, (unsigned long)block,
105 current->comm, PTR_ERR(bh));
106
107 return bh;
108 }
109 if (!bh) {
110 ext4_error_inode(inode, func, line, block,
111 "Directory hole found");
112 return ERR_PTR(-EFSCORRUPTED);
113 }
114 dirent = (struct ext4_dir_entry *) bh->b_data;
115 /* Determine whether or not we have an index block */
116 if (is_dx(inode)) {
117 if (block == 0)
118 is_dx_block = 1;
119 else if (ext4_rec_len_from_disk(dirent->rec_len,
120 inode->i_sb->s_blocksize) ==
121 inode->i_sb->s_blocksize)
122 is_dx_block = 1;
123 }
124 if (!is_dx_block && type == INDEX) {
125 ext4_error_inode(inode, func, line, block,
126 "directory leaf block found instead of index block");
127 return ERR_PTR(-EFSCORRUPTED);
128 }
129 if (!ext4_has_metadata_csum(inode->i_sb) ||
130 buffer_verified(bh))
131 return bh;
132
133 /*
134 * An empty leaf block can get mistaken for a index block; for
135 * this reason, we can only check the index checksum when the
136 * caller is sure it should be an index block.
137 */
138 if (is_dx_block && type == INDEX) {
139 if (ext4_dx_csum_verify(inode, dirent))
140 set_buffer_verified(bh);
141 else {
142 ext4_error_inode(inode, func, line, block,
143 "Directory index failed checksum");
144 brelse(bh);
145 return ERR_PTR(-EFSBADCRC);
146 }
147 }
148 if (!is_dx_block) {
149 if (ext4_dirent_csum_verify(inode, dirent))
150 set_buffer_verified(bh);
151 else {
152 ext4_error_inode(inode, func, line, block,
153 "Directory block failed checksum");
154 brelse(bh);
155 return ERR_PTR(-EFSBADCRC);
156 }
157 }
158 return bh;
159}
160
161#ifndef assert
162#define assert(test) J_ASSERT(test)
163#endif
164
165#ifdef DX_DEBUG
166#define dxtrace(command) command
167#else
168#define dxtrace(command)
169#endif
170
171struct fake_dirent
172{
173 __le32 inode;
174 __le16 rec_len;
175 u8 name_len;
176 u8 file_type;
177};
178
179struct dx_countlimit
180{
181 __le16 limit;
182 __le16 count;
183};
184
185struct dx_entry
186{
187 __le32 hash;
188 __le32 block;
189};
190
191/*
192 * dx_root_info is laid out so that if it should somehow get overlaid by a
193 * dirent the two low bits of the hash version will be zero. Therefore, the
194 * hash version mod 4 should never be 0. Sincerely, the paranoia department.
195 */
196
197struct dx_root
198{
199 struct fake_dirent dot;
200 char dot_name[4];
201 struct fake_dirent dotdot;
202 char dotdot_name[4];
203 struct dx_root_info
204 {
205 __le32 reserved_zero;
206 u8 hash_version;
207 u8 info_length; /* 8 */
208 u8 indirect_levels;
209 u8 unused_flags;
210 }
211 info;
212 struct dx_entry entries[0];
213};
214
215struct dx_node
216{
217 struct fake_dirent fake;
218 struct dx_entry entries[0];
219};
220
221
222struct dx_frame
223{
224 struct buffer_head *bh;
225 struct dx_entry *entries;
226 struct dx_entry *at;
227};
228
229struct dx_map_entry
230{
231 u32 hash;
232 u16 offs;
233 u16 size;
234};
235
236/*
237 * This goes at the end of each htree block.
238 */
239struct dx_tail {
240 u32 dt_reserved;
241 __le32 dt_checksum; /* crc32c(uuid+inum+dirblock) */
242};
243
244static inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
245static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
246static inline unsigned dx_get_hash(struct dx_entry *entry);
247static void dx_set_hash(struct dx_entry *entry, unsigned value);
248static unsigned dx_get_count(struct dx_entry *entries);
249static unsigned dx_get_limit(struct dx_entry *entries);
250static void dx_set_count(struct dx_entry *entries, unsigned value);
251static void dx_set_limit(struct dx_entry *entries, unsigned value);
252static unsigned dx_root_limit(struct inode *dir, unsigned infosize);
253static unsigned dx_node_limit(struct inode *dir);
254static struct dx_frame *dx_probe(struct ext4_filename *fname,
255 struct inode *dir,
256 struct dx_hash_info *hinfo,
257 struct dx_frame *frame);
258static void dx_release(struct dx_frame *frames);
259static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de,
260 unsigned blocksize, struct dx_hash_info *hinfo,
261 struct dx_map_entry map[]);
262static void dx_sort_map(struct dx_map_entry *map, unsigned count);
263static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to,
264 struct dx_map_entry *offsets, int count, unsigned blocksize);
265static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize);
266static void dx_insert_block(struct dx_frame *frame,
267 u32 hash, ext4_lblk_t block);
268static int ext4_htree_next_block(struct inode *dir, __u32 hash,
269 struct dx_frame *frame,
270 struct dx_frame *frames,
271 __u32 *start_hash);
272static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
273 struct ext4_filename *fname,
274 struct ext4_dir_entry_2 **res_dir);
275static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
276 struct inode *dir, struct inode *inode);
277
278/* checksumming functions */
279void initialize_dirent_tail(struct ext4_dir_entry_tail *t,
280 unsigned int blocksize)
281{
282 memset(t, 0, sizeof(struct ext4_dir_entry_tail));
283 t->det_rec_len = ext4_rec_len_to_disk(
284 sizeof(struct ext4_dir_entry_tail), blocksize);
285 t->det_reserved_ft = EXT4_FT_DIR_CSUM;
286}
287
288/* Walk through a dirent block to find a checksum "dirent" at the tail */
289static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode,
290 struct ext4_dir_entry *de)
291{
292 struct ext4_dir_entry_tail *t;
293
294#ifdef PARANOID
295 struct ext4_dir_entry *d, *top;
296
297 d = de;
298 top = (struct ext4_dir_entry *)(((void *)de) +
299 (EXT4_BLOCK_SIZE(inode->i_sb) -
300 sizeof(struct ext4_dir_entry_tail)));
301 while (d < top && d->rec_len)
302 d = (struct ext4_dir_entry *)(((void *)d) +
303 le16_to_cpu(d->rec_len));
304
305 if (d != top)
306 return NULL;
307
308 t = (struct ext4_dir_entry_tail *)d;
309#else
310 t = EXT4_DIRENT_TAIL(de, EXT4_BLOCK_SIZE(inode->i_sb));
311#endif
312
313 if (t->det_reserved_zero1 ||
314 le16_to_cpu(t->det_rec_len) != sizeof(struct ext4_dir_entry_tail) ||
315 t->det_reserved_zero2 ||
316 t->det_reserved_ft != EXT4_FT_DIR_CSUM)
317 return NULL;
318
319 return t;
320}
321
322static __le32 ext4_dirent_csum(struct inode *inode,
323 struct ext4_dir_entry *dirent, int size)
324{
325 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
326 struct ext4_inode_info *ei = EXT4_I(inode);
327 __u32 csum;
328
329 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
330 return cpu_to_le32(csum);
331}
332
333#define warn_no_space_for_csum(inode) \
334 __warn_no_space_for_csum((inode), __func__, __LINE__)
335
336static void __warn_no_space_for_csum(struct inode *inode, const char *func,
337 unsigned int line)
338{
339 __ext4_warning_inode(inode, func, line,
340 "No space for directory leaf checksum. Please run e2fsck -D.");
341}
342
343int ext4_dirent_csum_verify(struct inode *inode, struct ext4_dir_entry *dirent)
344{
345 struct ext4_dir_entry_tail *t;
346
347 if (!ext4_has_metadata_csum(inode->i_sb))
348 return 1;
349
350 t = get_dirent_tail(inode, dirent);
351 if (!t) {
352 warn_no_space_for_csum(inode);
353 return 0;
354 }
355
356 if (t->det_checksum != ext4_dirent_csum(inode, dirent,
357 (void *)t - (void *)dirent))
358 return 0;
359
360 return 1;
361}
362
363static void ext4_dirent_csum_set(struct inode *inode,
364 struct ext4_dir_entry *dirent)
365{
366 struct ext4_dir_entry_tail *t;
367
368 if (!ext4_has_metadata_csum(inode->i_sb))
369 return;
370
371 t = get_dirent_tail(inode, dirent);
372 if (!t) {
373 warn_no_space_for_csum(inode);
374 return;
375 }
376
377 t->det_checksum = ext4_dirent_csum(inode, dirent,
378 (void *)t - (void *)dirent);
379}
380
381int ext4_handle_dirty_dirent_node(handle_t *handle,
382 struct inode *inode,
383 struct buffer_head *bh)
384{
385 ext4_dirent_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
386 return ext4_handle_dirty_metadata(handle, inode, bh);
387}
388
389static struct dx_countlimit *get_dx_countlimit(struct inode *inode,
390 struct ext4_dir_entry *dirent,
391 int *offset)
392{
393 struct ext4_dir_entry *dp;
394 struct dx_root_info *root;
395 int count_offset;
396
397 if (le16_to_cpu(dirent->rec_len) == EXT4_BLOCK_SIZE(inode->i_sb))
398 count_offset = 8;
399 else if (le16_to_cpu(dirent->rec_len) == 12) {
400 dp = (struct ext4_dir_entry *)(((void *)dirent) + 12);
401 if (le16_to_cpu(dp->rec_len) !=
402 EXT4_BLOCK_SIZE(inode->i_sb) - 12)
403 return NULL;
404 root = (struct dx_root_info *)(((void *)dp + 12));
405 if (root->reserved_zero ||
406 root->info_length != sizeof(struct dx_root_info))
407 return NULL;
408 count_offset = 32;
409 } else
410 return NULL;
411
412 if (offset)
413 *offset = count_offset;
414 return (struct dx_countlimit *)(((void *)dirent) + count_offset);
415}
416
417static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent,
418 int count_offset, int count, struct dx_tail *t)
419{
420 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
421 struct ext4_inode_info *ei = EXT4_I(inode);
422 __u32 csum;
423 __le32 save_csum;
424 int size;
425
426 size = count_offset + (count * sizeof(struct dx_entry));
427 save_csum = t->dt_checksum;
428 t->dt_checksum = 0;
429 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
430 csum = ext4_chksum(sbi, csum, (__u8 *)t, sizeof(struct dx_tail));
431 t->dt_checksum = save_csum;
432
433 return cpu_to_le32(csum);
434}
435
436static int ext4_dx_csum_verify(struct inode *inode,
437 struct ext4_dir_entry *dirent)
438{
439 struct dx_countlimit *c;
440 struct dx_tail *t;
441 int count_offset, limit, count;
442
443 if (!ext4_has_metadata_csum(inode->i_sb))
444 return 1;
445
446 c = get_dx_countlimit(inode, dirent, &count_offset);
447 if (!c) {
448 EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D.");
449 return 1;
450 }
451 limit = le16_to_cpu(c->limit);
452 count = le16_to_cpu(c->count);
453 if (count_offset + (limit * sizeof(struct dx_entry)) >
454 EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
455 warn_no_space_for_csum(inode);
456 return 1;
457 }
458 t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
459
460 if (t->dt_checksum != ext4_dx_csum(inode, dirent, count_offset,
461 count, t))
462 return 0;
463 return 1;
464}
465
466static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent)
467{
468 struct dx_countlimit *c;
469 struct dx_tail *t;
470 int count_offset, limit, count;
471
472 if (!ext4_has_metadata_csum(inode->i_sb))
473 return;
474
475 c = get_dx_countlimit(inode, dirent, &count_offset);
476 if (!c) {
477 EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D.");
478 return;
479 }
480 limit = le16_to_cpu(c->limit);
481 count = le16_to_cpu(c->count);
482 if (count_offset + (limit * sizeof(struct dx_entry)) >
483 EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
484 warn_no_space_for_csum(inode);
485 return;
486 }
487 t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
488
489 t->dt_checksum = ext4_dx_csum(inode, dirent, count_offset, count, t);
490}
491
492static inline int ext4_handle_dirty_dx_node(handle_t *handle,
493 struct inode *inode,
494 struct buffer_head *bh)
495{
496 ext4_dx_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
497 return ext4_handle_dirty_metadata(handle, inode, bh);
498}
499
500/*
501 * p is at least 6 bytes before the end of page
502 */
503static inline struct ext4_dir_entry_2 *
504ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
505{
506 return (struct ext4_dir_entry_2 *)((char *)p +
507 ext4_rec_len_from_disk(p->rec_len, blocksize));
508}
509
510/*
511 * Future: use high four bits of block for coalesce-on-delete flags
512 * Mask them off for now.
513 */
514
515static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
516{
517 return le32_to_cpu(entry->block) & 0x00ffffff;
518}
519
520static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
521{
522 entry->block = cpu_to_le32(value);
523}
524
525static inline unsigned dx_get_hash(struct dx_entry *entry)
526{
527 return le32_to_cpu(entry->hash);
528}
529
530static inline void dx_set_hash(struct dx_entry *entry, unsigned value)
531{
532 entry->hash = cpu_to_le32(value);
533}
534
535static inline unsigned dx_get_count(struct dx_entry *entries)
536{
537 return le16_to_cpu(((struct dx_countlimit *) entries)->count);
538}
539
540static inline unsigned dx_get_limit(struct dx_entry *entries)
541{
542 return le16_to_cpu(((struct dx_countlimit *) entries)->limit);
543}
544
545static inline void dx_set_count(struct dx_entry *entries, unsigned value)
546{
547 ((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
548}
549
550static inline void dx_set_limit(struct dx_entry *entries, unsigned value)
551{
552 ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
553}
554
555static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
556{
557 unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
558 EXT4_DIR_REC_LEN(2) - infosize;
559
560 if (ext4_has_metadata_csum(dir->i_sb))
561 entry_space -= sizeof(struct dx_tail);
562 return entry_space / sizeof(struct dx_entry);
563}
564
565static inline unsigned dx_node_limit(struct inode *dir)
566{
567 unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);
568
569 if (ext4_has_metadata_csum(dir->i_sb))
570 entry_space -= sizeof(struct dx_tail);
571 return entry_space / sizeof(struct dx_entry);
572}
573
574/*
575 * Debug
576 */
577#ifdef DX_DEBUG
578static void dx_show_index(char * label, struct dx_entry *entries)
579{
580 int i, n = dx_get_count (entries);
581 printk(KERN_DEBUG "%s index ", label);
582 for (i = 0; i < n; i++) {
583 printk("%x->%lu ", i ? dx_get_hash(entries + i) :
584 0, (unsigned long)dx_get_block(entries + i));
585 }
586 printk("\n");
587}
588
589struct stats
590{
591 unsigned names;
592 unsigned space;
593 unsigned bcount;
594};
595
596static struct stats dx_show_leaf(struct inode *dir,
597 struct dx_hash_info *hinfo,
598 struct ext4_dir_entry_2 *de,
599 int size, int show_names)
600{
601 unsigned names = 0, space = 0;
602 char *base = (char *) de;
603 struct dx_hash_info h = *hinfo;
604
605 printk("names: ");
606 while ((char *) de < base + size)
607 {
608 if (de->inode)
609 {
610 if (show_names)
611 {
612#ifdef CONFIG_EXT4_FS_ENCRYPTION
613 int len;
614 char *name;
615 struct ext4_str fname_crypto_str
616 = {.name = NULL, .len = 0};
617 int res = 0;
618
619 name = de->name;
620 len = de->name_len;
621 if (ext4_encrypted_inode(inode))
622 res = ext4_get_encryption_info(dir);
623 if (res) {
624 printk(KERN_WARNING "Error setting up"
625 " fname crypto: %d\n", res);
626 }
627 if (ctx == NULL) {
628 /* Directory is not encrypted */
629 ext4fs_dirhash(de->name,
630 de->name_len, &h);
631 printk("%*.s:(U)%x.%u ", len,
632 name, h.hash,
633 (unsigned) ((char *) de
634 - base));
635 } else {
636 /* Directory is encrypted */
637 res = ext4_fname_crypto_alloc_buffer(
638 ctx, de->name_len,
639 &fname_crypto_str);
640 if (res < 0) {
641 printk(KERN_WARNING "Error "
642 "allocating crypto "
643 "buffer--skipping "
644 "crypto\n");
645 ctx = NULL;
646 }
647 res = ext4_fname_disk_to_usr(ctx, NULL, de,
648 &fname_crypto_str);
649 if (res < 0) {
650 printk(KERN_WARNING "Error "
651 "converting filename "
652 "from disk to usr"
653 "\n");
654 name = "??";
655 len = 2;
656 } else {
657 name = fname_crypto_str.name;
658 len = fname_crypto_str.len;
659 }
660 ext4fs_dirhash(de->name, de->name_len,
661 &h);
662 printk("%*.s:(E)%x.%u ", len, name,
663 h.hash, (unsigned) ((char *) de
664 - base));
665 ext4_fname_crypto_free_buffer(
666 &fname_crypto_str);
667 }
668#else
669 int len = de->name_len;
670 char *name = de->name;
671 ext4fs_dirhash(de->name, de->name_len, &h);
672 printk("%*.s:%x.%u ", len, name, h.hash,
673 (unsigned) ((char *) de - base));
674#endif
675 }
676 space += EXT4_DIR_REC_LEN(de->name_len);
677 names++;
678 }
679 de = ext4_next_entry(de, size);
680 }
681 printk("(%i)\n", names);
682 return (struct stats) { names, space, 1 };
683}
684
685struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
686 struct dx_entry *entries, int levels)
687{
688 unsigned blocksize = dir->i_sb->s_blocksize;
689 unsigned count = dx_get_count(entries), names = 0, space = 0, i;
690 unsigned bcount = 0;
691 struct buffer_head *bh;
692 printk("%i indexed blocks...\n", count);
693 for (i = 0; i < count; i++, entries++)
694 {
695 ext4_lblk_t block = dx_get_block(entries);
696 ext4_lblk_t hash = i ? dx_get_hash(entries): 0;
697 u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
698 struct stats stats;
699 printk("%s%3u:%03u hash %8x/%8x ",levels?"":" ", i, block, hash, range);
700 bh = ext4_bread(NULL,dir, block, 0);
701 if (!bh || IS_ERR(bh))
702 continue;
703 stats = levels?
704 dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
705 dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *)
706 bh->b_data, blocksize, 0);
707 names += stats.names;
708 space += stats.space;
709 bcount += stats.bcount;
710 brelse(bh);
711 }
712 if (bcount)
713 printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n",
714 levels ? "" : " ", names, space/bcount,
715 (space/bcount)*100/blocksize);
716 return (struct stats) { names, space, bcount};
717}
718#endif /* DX_DEBUG */
719
720/*
721 * Probe for a directory leaf block to search.
722 *
723 * dx_probe can return ERR_BAD_DX_DIR, which means there was a format
724 * error in the directory index, and the caller should fall back to
725 * searching the directory normally. The callers of dx_probe **MUST**
726 * check for this error code, and make sure it never gets reflected
727 * back to userspace.
728 */
729static struct dx_frame *
730dx_probe(struct ext4_filename *fname, struct inode *dir,
731 struct dx_hash_info *hinfo, struct dx_frame *frame_in)
732{
733 unsigned count, indirect;
734 struct dx_entry *at, *entries, *p, *q, *m;
735 struct dx_root *root;
736 struct dx_frame *frame = frame_in;
737 struct dx_frame *ret_err = ERR_PTR(ERR_BAD_DX_DIR);
738 u32 hash;
739
740 frame->bh = ext4_read_dirblock(dir, 0, INDEX);
741 if (IS_ERR(frame->bh))
742 return (struct dx_frame *) frame->bh;
743
744 root = (struct dx_root *) frame->bh->b_data;
745 if (root->info.hash_version != DX_HASH_TEA &&
746 root->info.hash_version != DX_HASH_HALF_MD4 &&
747 root->info.hash_version != DX_HASH_LEGACY) {
748 ext4_warning_inode(dir, "Unrecognised inode hash code %u",
749 root->info.hash_version);
750 goto fail;
751 }
752 if (fname)
753 hinfo = &fname->hinfo;
754 hinfo->hash_version = root->info.hash_version;
755 if (hinfo->hash_version <= DX_HASH_TEA)
756 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
757 hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
758 if (fname && fname_name(fname))
759 ext4fs_dirhash(fname_name(fname), fname_len(fname), hinfo);
760 hash = hinfo->hash;
761
762 if (root->info.unused_flags & 1) {
763 ext4_warning_inode(dir, "Unimplemented hash flags: %#06x",
764 root->info.unused_flags);
765 goto fail;
766 }
767
768 indirect = root->info.indirect_levels;
769 if (indirect > 1) {
770 ext4_warning_inode(dir, "Unimplemented hash depth: %#06x",
771 root->info.indirect_levels);
772 goto fail;
773 }
774
775 entries = (struct dx_entry *)(((char *)&root->info) +
776 root->info.info_length);
777
778 if (dx_get_limit(entries) != dx_root_limit(dir,
779 root->info.info_length)) {
780 ext4_warning_inode(dir, "dx entry: limit %u != root limit %u",
781 dx_get_limit(entries),
782 dx_root_limit(dir, root->info.info_length));
783 goto fail;
784 }
785
786 dxtrace(printk("Look up %x", hash));
787 while (1) {
788 count = dx_get_count(entries);
789 if (!count || count > dx_get_limit(entries)) {
790 ext4_warning_inode(dir,
791 "dx entry: count %u beyond limit %u",
792 count, dx_get_limit(entries));
793 goto fail;
794 }
795
796 p = entries + 1;
797 q = entries + count - 1;
798 while (p <= q) {
799 m = p + (q - p) / 2;
800 dxtrace(printk("."));
801 if (dx_get_hash(m) > hash)
802 q = m - 1;
803 else
804 p = m + 1;
805 }
806
807 if (0) { // linear search cross check
808 unsigned n = count - 1;
809 at = entries;
810 while (n--)
811 {
812 dxtrace(printk(","));
813 if (dx_get_hash(++at) > hash)
814 {
815 at--;
816 break;
817 }
818 }
819 assert (at == p - 1);
820 }
821
822 at = p - 1;
823 dxtrace(printk(" %x->%u\n", at == entries ? 0 : dx_get_hash(at),
824 dx_get_block(at)));
825 frame->entries = entries;
826 frame->at = at;
827 if (!indirect--)
828 return frame;
829 frame++;
830 frame->bh = ext4_read_dirblock(dir, dx_get_block(at), INDEX);
831 if (IS_ERR(frame->bh)) {
832 ret_err = (struct dx_frame *) frame->bh;
833 frame->bh = NULL;
834 goto fail;
835 }
836 entries = ((struct dx_node *) frame->bh->b_data)->entries;
837
838 if (dx_get_limit(entries) != dx_node_limit(dir)) {
839 ext4_warning_inode(dir,
840 "dx entry: limit %u != node limit %u",
841 dx_get_limit(entries), dx_node_limit(dir));
842 goto fail;
843 }
844 }
845fail:
846 while (frame >= frame_in) {
847 brelse(frame->bh);
848 frame--;
849 }
850
851 if (ret_err == ERR_PTR(ERR_BAD_DX_DIR))
852 ext4_warning_inode(dir,
853 "Corrupt directory, running e2fsck is recommended");
854 return ret_err;
855}
856
857static void dx_release(struct dx_frame *frames)
858{
859 if (frames[0].bh == NULL)
860 return;
861
862 if (((struct dx_root *)frames[0].bh->b_data)->info.indirect_levels)
863 brelse(frames[1].bh);
864 brelse(frames[0].bh);
865}
866
867/*
868 * This function increments the frame pointer to search the next leaf
869 * block, and reads in the necessary intervening nodes if the search
870 * should be necessary. Whether or not the search is necessary is
871 * controlled by the hash parameter. If the hash value is even, then
872 * the search is only continued if the next block starts with that
873 * hash value. This is used if we are searching for a specific file.
874 *
875 * If the hash value is HASH_NB_ALWAYS, then always go to the next block.
876 *
877 * This function returns 1 if the caller should continue to search,
878 * or 0 if it should not. If there is an error reading one of the
879 * index blocks, it will a negative error code.
880 *
881 * If start_hash is non-null, it will be filled in with the starting
882 * hash of the next page.
883 */
884static int ext4_htree_next_block(struct inode *dir, __u32 hash,
885 struct dx_frame *frame,
886 struct dx_frame *frames,
887 __u32 *start_hash)
888{
889 struct dx_frame *p;
890 struct buffer_head *bh;
891 int num_frames = 0;
892 __u32 bhash;
893
894 p = frame;
895 /*
896 * Find the next leaf page by incrementing the frame pointer.
897 * If we run out of entries in the interior node, loop around and
898 * increment pointer in the parent node. When we break out of
899 * this loop, num_frames indicates the number of interior
900 * nodes need to be read.
901 */
902 while (1) {
903 if (++(p->at) < p->entries + dx_get_count(p->entries))
904 break;
905 if (p == frames)
906 return 0;
907 num_frames++;
908 p--;
909 }
910
911 /*
912 * If the hash is 1, then continue only if the next page has a
913 * continuation hash of any value. This is used for readdir
914 * handling. Otherwise, check to see if the hash matches the
915 * desired contiuation hash. If it doesn't, return since
916 * there's no point to read in the successive index pages.
917 */
918 bhash = dx_get_hash(p->at);
919 if (start_hash)
920 *start_hash = bhash;
921 if ((hash & 1) == 0) {
922 if ((bhash & ~1) != hash)
923 return 0;
924 }
925 /*
926 * If the hash is HASH_NB_ALWAYS, we always go to the next
927 * block so no check is necessary
928 */
929 while (num_frames--) {
930 bh = ext4_read_dirblock(dir, dx_get_block(p->at), INDEX);
931 if (IS_ERR(bh))
932 return PTR_ERR(bh);
933 p++;
934 brelse(p->bh);
935 p->bh = bh;
936 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
937 }
938 return 1;
939}
940
941
942/*
943 * This function fills a red-black tree with information from a
944 * directory block. It returns the number directory entries loaded
945 * into the tree. If there is an error it is returned in err.
946 */
947static int htree_dirblock_to_tree(struct file *dir_file,
948 struct inode *dir, ext4_lblk_t block,
949 struct dx_hash_info *hinfo,
950 __u32 start_hash, __u32 start_minor_hash)
951{
952 struct buffer_head *bh;
953 struct ext4_dir_entry_2 *de, *top;
954 int err = 0, count = 0;
955 struct ext4_str fname_crypto_str = {.name = NULL, .len = 0}, tmp_str;
956
957 dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
958 (unsigned long)block));
959 bh = ext4_read_dirblock(dir, block, DIRENT);
960 if (IS_ERR(bh))
961 return PTR_ERR(bh);
962
963 de = (struct ext4_dir_entry_2 *) bh->b_data;
964 top = (struct ext4_dir_entry_2 *) ((char *) de +
965 dir->i_sb->s_blocksize -
966 EXT4_DIR_REC_LEN(0));
967#ifdef CONFIG_EXT4_FS_ENCRYPTION
968 /* Check if the directory is encrypted */
969 if (ext4_encrypted_inode(dir)) {
970 err = ext4_get_encryption_info(dir);
971 if (err < 0) {
972 brelse(bh);
973 return err;
974 }
975 err = ext4_fname_crypto_alloc_buffer(dir, EXT4_NAME_LEN,
976 &fname_crypto_str);
977 if (err < 0) {
978 brelse(bh);
979 return err;
980 }
981 }
982#endif
983 for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) {
984 if (ext4_check_dir_entry(dir, NULL, de, bh,
985 bh->b_data, bh->b_size,
986 (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
987 + ((char *)de - bh->b_data))) {
988 /* silently ignore the rest of the block */
989 break;
990 }
991 ext4fs_dirhash(de->name, de->name_len, hinfo);
992 if ((hinfo->hash < start_hash) ||
993 ((hinfo->hash == start_hash) &&
994 (hinfo->minor_hash < start_minor_hash)))
995 continue;
996 if (de->inode == 0)
997 continue;
998 if (!ext4_encrypted_inode(dir)) {
999 tmp_str.name = de->name;
1000 tmp_str.len = de->name_len;
1001 err = ext4_htree_store_dirent(dir_file,
1002 hinfo->hash, hinfo->minor_hash, de,
1003 &tmp_str);
1004 } else {
1005 int save_len = fname_crypto_str.len;
1006
1007 /* Directory is encrypted */
1008 err = ext4_fname_disk_to_usr(dir, hinfo, de,
1009 &fname_crypto_str);
1010 if (err < 0) {
1011 count = err;
1012 goto errout;
1013 }
1014 err = ext4_htree_store_dirent(dir_file,
1015 hinfo->hash, hinfo->minor_hash, de,
1016 &fname_crypto_str);
1017 fname_crypto_str.len = save_len;
1018 }
1019 if (err != 0) {
1020 count = err;
1021 goto errout;
1022 }
1023 count++;
1024 }
1025errout:
1026 brelse(bh);
1027#ifdef CONFIG_EXT4_FS_ENCRYPTION
1028 ext4_fname_crypto_free_buffer(&fname_crypto_str);
1029#endif
1030 return count;
1031}
1032
1033
1034/*
1035 * This function fills a red-black tree with information from a
1036 * directory. We start scanning the directory in hash order, starting
1037 * at start_hash and start_minor_hash.
1038 *
1039 * This function returns the number of entries inserted into the tree,
1040 * or a negative error code.
1041 */
1042int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
1043 __u32 start_minor_hash, __u32 *next_hash)
1044{
1045 struct dx_hash_info hinfo;
1046 struct ext4_dir_entry_2 *de;
1047 struct dx_frame frames[2], *frame;
1048 struct inode *dir;
1049 ext4_lblk_t block;
1050 int count = 0;
1051 int ret, err;
1052 __u32 hashval;
1053 struct ext4_str tmp_str;
1054
1055 dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
1056 start_hash, start_minor_hash));
1057 dir = file_inode(dir_file);
1058 if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) {
1059 hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
1060 if (hinfo.hash_version <= DX_HASH_TEA)
1061 hinfo.hash_version +=
1062 EXT4_SB(dir->i_sb)->s_hash_unsigned;
1063 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
1064 if (ext4_has_inline_data(dir)) {
1065 int has_inline_data = 1;
1066 count = htree_inlinedir_to_tree(dir_file, dir, 0,
1067 &hinfo, start_hash,
1068 start_minor_hash,
1069 &has_inline_data);
1070 if (has_inline_data) {
1071 *next_hash = ~0;
1072 return count;
1073 }
1074 }
1075 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
1076 start_hash, start_minor_hash);
1077 *next_hash = ~0;
1078 return count;
1079 }
1080 hinfo.hash = start_hash;
1081 hinfo.minor_hash = 0;
1082 frame = dx_probe(NULL, dir, &hinfo, frames);
1083 if (IS_ERR(frame))
1084 return PTR_ERR(frame);
1085
1086 /* Add '.' and '..' from the htree header */
1087 if (!start_hash && !start_minor_hash) {
1088 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
1089 tmp_str.name = de->name;
1090 tmp_str.len = de->name_len;
1091 err = ext4_htree_store_dirent(dir_file, 0, 0,
1092 de, &tmp_str);
1093 if (err != 0)
1094 goto errout;
1095 count++;
1096 }
1097 if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
1098 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
1099 de = ext4_next_entry(de, dir->i_sb->s_blocksize);
1100 tmp_str.name = de->name;
1101 tmp_str.len = de->name_len;
1102 err = ext4_htree_store_dirent(dir_file, 2, 0,
1103 de, &tmp_str);
1104 if (err != 0)
1105 goto errout;
1106 count++;
1107 }
1108
1109 while (1) {
1110 block = dx_get_block(frame->at);
1111 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
1112 start_hash, start_minor_hash);
1113 if (ret < 0) {
1114 err = ret;
1115 goto errout;
1116 }
1117 count += ret;
1118 hashval = ~0;
1119 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
1120 frame, frames, &hashval);
1121 *next_hash = hashval;
1122 if (ret < 0) {
1123 err = ret;
1124 goto errout;
1125 }
1126 /*
1127 * Stop if: (a) there are no more entries, or
1128 * (b) we have inserted at least one entry and the
1129 * next hash value is not a continuation
1130 */
1131 if ((ret == 0) ||
1132 (count && ((hashval & 1) == 0)))
1133 break;
1134 }
1135 dx_release(frames);
1136 dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, "
1137 "next hash: %x\n", count, *next_hash));
1138 return count;
1139errout:
1140 dx_release(frames);
1141 return (err);
1142}
1143
1144static inline int search_dirblock(struct buffer_head *bh,
1145 struct inode *dir,
1146 struct ext4_filename *fname,
1147 const struct qstr *d_name,
1148 unsigned int offset,
1149 struct ext4_dir_entry_2 **res_dir)
1150{
1151 return ext4_search_dir(bh, bh->b_data, dir->i_sb->s_blocksize, dir,
1152 fname, d_name, offset, res_dir);
1153}
1154
1155/*
1156 * Directory block splitting, compacting
1157 */
1158
1159/*
1160 * Create map of hash values, offsets, and sizes, stored at end of block.
1161 * Returns number of entries mapped.
1162 */
1163static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de,
1164 unsigned blocksize, struct dx_hash_info *hinfo,
1165 struct dx_map_entry *map_tail)
1166{
1167 int count = 0;
1168 char *base = (char *) de;
1169 struct dx_hash_info h = *hinfo;
1170
1171 while ((char *) de < base + blocksize) {
1172 if (de->name_len && de->inode) {
1173 ext4fs_dirhash(de->name, de->name_len, &h);
1174 map_tail--;
1175 map_tail->hash = h.hash;
1176 map_tail->offs = ((char *) de - base)>>2;
1177 map_tail->size = le16_to_cpu(de->rec_len);
1178 count++;
1179 cond_resched();
1180 }
1181 /* XXX: do we need to check rec_len == 0 case? -Chris */
1182 de = ext4_next_entry(de, blocksize);
1183 }
1184 return count;
1185}
1186
1187/* Sort map by hash value */
1188static void dx_sort_map (struct dx_map_entry *map, unsigned count)
1189{
1190 struct dx_map_entry *p, *q, *top = map + count - 1;
1191 int more;
1192 /* Combsort until bubble sort doesn't suck */
1193 while (count > 2) {
1194 count = count*10/13;
1195 if (count - 9 < 2) /* 9, 10 -> 11 */
1196 count = 11;
1197 for (p = top, q = p - count; q >= map; p--, q--)
1198 if (p->hash < q->hash)
1199 swap(*p, *q);
1200 }
1201 /* Garden variety bubble sort */
1202 do {
1203 more = 0;
1204 q = top;
1205 while (q-- > map) {
1206 if (q[1].hash >= q[0].hash)
1207 continue;
1208 swap(*(q+1), *q);
1209 more = 1;
1210 }
1211 } while(more);
1212}
1213
1214static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
1215{
1216 struct dx_entry *entries = frame->entries;
1217 struct dx_entry *old = frame->at, *new = old + 1;
1218 int count = dx_get_count(entries);
1219
1220 assert(count < dx_get_limit(entries));
1221 assert(old < entries + count);
1222 memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
1223 dx_set_hash(new, hash);
1224 dx_set_block(new, block);
1225 dx_set_count(entries, count + 1);
1226}
1227
1228/*
1229 * NOTE! unlike strncmp, ext4_match returns 1 for success, 0 for failure.
1230 *
1231 * `len <= EXT4_NAME_LEN' is guaranteed by caller.
1232 * `de != NULL' is guaranteed by caller.
1233 */
1234static inline int ext4_match(struct ext4_filename *fname,
1235 struct ext4_dir_entry_2 *de)
1236{
1237 const void *name = fname_name(fname);
1238 u32 len = fname_len(fname);
1239
1240 if (!de->inode)
1241 return 0;
1242
1243#ifdef CONFIG_EXT4_FS_ENCRYPTION
1244 if (unlikely(!name)) {
1245 if (fname->usr_fname->name[0] == '_') {
1246 int ret;
1247 if (de->name_len < 16)
1248 return 0;
1249 ret = memcmp(de->name + de->name_len - 16,
1250 fname->crypto_buf.name + 8, 16);
1251 return (ret == 0) ? 1 : 0;
1252 }
1253 name = fname->crypto_buf.name;
1254 len = fname->crypto_buf.len;
1255 }
1256#endif
1257 if (de->name_len != len)
1258 return 0;
1259 return (memcmp(de->name, name, len) == 0) ? 1 : 0;
1260}
1261
1262/*
1263 * Returns 0 if not found, -1 on failure, and 1 on success
1264 */
1265int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size,
1266 struct inode *dir, struct ext4_filename *fname,
1267 const struct qstr *d_name,
1268 unsigned int offset, struct ext4_dir_entry_2 **res_dir)
1269{
1270 struct ext4_dir_entry_2 * de;
1271 char * dlimit;
1272 int de_len;
1273 int res;
1274
1275 de = (struct ext4_dir_entry_2 *)search_buf;
1276 dlimit = search_buf + buf_size;
1277 while ((char *) de < dlimit) {
1278 /* this code is executed quadratically often */
1279 /* do minimal checking `by hand' */
1280 if ((char *) de + de->name_len <= dlimit) {
1281 res = ext4_match(fname, de);
1282 if (res < 0) {
1283 res = -1;
1284 goto return_result;
1285 }
1286 if (res > 0) {
1287 /* found a match - just to be sure, do
1288 * a full check */
1289 if (ext4_check_dir_entry(dir, NULL, de, bh,
1290 bh->b_data,
1291 bh->b_size, offset)) {
1292 res = -1;
1293 goto return_result;
1294 }
1295 *res_dir = de;
1296 res = 1;
1297 goto return_result;
1298 }
1299
1300 }
1301 /* prevent looping on a bad block */
1302 de_len = ext4_rec_len_from_disk(de->rec_len,
1303 dir->i_sb->s_blocksize);
1304 if (de_len <= 0) {
1305 res = -1;
1306 goto return_result;
1307 }
1308 offset += de_len;
1309 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
1310 }
1311
1312 res = 0;
1313return_result:
1314 return res;
1315}
1316
1317static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block,
1318 struct ext4_dir_entry *de)
1319{
1320 struct super_block *sb = dir->i_sb;
1321
1322 if (!is_dx(dir))
1323 return 0;
1324 if (block == 0)
1325 return 1;
1326 if (de->inode == 0 &&
1327 ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) ==
1328 sb->s_blocksize)
1329 return 1;
1330 return 0;
1331}
1332
1333/*
1334 * ext4_find_entry()
1335 *
1336 * finds an entry in the specified directory with the wanted name. It
1337 * returns the cache buffer in which the entry was found, and the entry
1338 * itself (as a parameter - res_dir). It does NOT read the inode of the
1339 * entry - you'll have to do that yourself if you want to.
1340 *
1341 * The returned buffer_head has ->b_count elevated. The caller is expected
1342 * to brelse() it when appropriate.
1343 */
1344static struct buffer_head * ext4_find_entry (struct inode *dir,
1345 const struct qstr *d_name,
1346 struct ext4_dir_entry_2 **res_dir,
1347 int *inlined)
1348{
1349 struct super_block *sb;
1350 struct buffer_head *bh_use[NAMEI_RA_SIZE];
1351 struct buffer_head *bh, *ret = NULL;
1352 ext4_lblk_t start, block, b;
1353 const u8 *name = d_name->name;
1354 int ra_max = 0; /* Number of bh's in the readahead
1355 buffer, bh_use[] */
1356 int ra_ptr = 0; /* Current index into readahead
1357 buffer */
1358 int num = 0;
1359 ext4_lblk_t nblocks;
1360 int i, namelen, retval;
1361 struct ext4_filename fname;
1362
1363 *res_dir = NULL;
1364 sb = dir->i_sb;
1365 namelen = d_name->len;
1366 if (namelen > EXT4_NAME_LEN)
1367 return NULL;
1368
1369 retval = ext4_fname_setup_filename(dir, d_name, 1, &fname);
1370 if (retval)
1371 return ERR_PTR(retval);
1372
1373 if (ext4_has_inline_data(dir)) {
1374 int has_inline_data = 1;
1375 ret = ext4_find_inline_entry(dir, &fname, d_name, res_dir,
1376 &has_inline_data);
1377 if (has_inline_data) {
1378 if (inlined)
1379 *inlined = 1;
1380 goto cleanup_and_exit;
1381 }
1382 }
1383
1384 if ((namelen <= 2) && (name[0] == '.') &&
1385 (name[1] == '.' || name[1] == '\0')) {
1386 /*
1387 * "." or ".." will only be in the first block
1388 * NFS may look up ".."; "." should be handled by the VFS
1389 */
1390 block = start = 0;
1391 nblocks = 1;
1392 goto restart;
1393 }
1394 if (is_dx(dir)) {
1395 ret = ext4_dx_find_entry(dir, &fname, res_dir);
1396 /*
1397 * On success, or if the error was file not found,
1398 * return. Otherwise, fall back to doing a search the
1399 * old fashioned way.
1400 */
1401 if (!IS_ERR(ret) || PTR_ERR(ret) != ERR_BAD_DX_DIR)
1402 goto cleanup_and_exit;
1403 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
1404 "falling back\n"));
1405 }
1406 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1407 start = EXT4_I(dir)->i_dir_start_lookup;
1408 if (start >= nblocks)
1409 start = 0;
1410 block = start;
1411restart:
1412 do {
1413 /*
1414 * We deal with the read-ahead logic here.
1415 */
1416 if (ra_ptr >= ra_max) {
1417 /* Refill the readahead buffer */
1418 ra_ptr = 0;
1419 b = block;
1420 for (ra_max = 0; ra_max < NAMEI_RA_SIZE; ra_max++) {
1421 /*
1422 * Terminate if we reach the end of the
1423 * directory and must wrap, or if our
1424 * search has finished at this block.
1425 */
1426 if (b >= nblocks || (num && block == start)) {
1427 bh_use[ra_max] = NULL;
1428 break;
1429 }
1430 num++;
1431 bh = ext4_getblk(NULL, dir, b++, 0);
1432 if (IS_ERR(bh)) {
1433 if (ra_max == 0) {
1434 ret = bh;
1435 goto cleanup_and_exit;
1436 }
1437 break;
1438 }
1439 bh_use[ra_max] = bh;
1440 if (bh)
1441 ll_rw_block(READ | REQ_META | REQ_PRIO,
1442 1, &bh);
1443 }
1444 }
1445 if ((bh = bh_use[ra_ptr++]) == NULL)
1446 goto next;
1447 wait_on_buffer(bh);
1448 if (!buffer_uptodate(bh)) {
1449 /* read error, skip block & hope for the best */
1450 EXT4_ERROR_INODE(dir, "reading directory lblock %lu",
1451 (unsigned long) block);
1452 brelse(bh);
1453 goto next;
1454 }
1455 if (!buffer_verified(bh) &&
1456 !is_dx_internal_node(dir, block,
1457 (struct ext4_dir_entry *)bh->b_data) &&
1458 !ext4_dirent_csum_verify(dir,
1459 (struct ext4_dir_entry *)bh->b_data)) {
1460 EXT4_ERROR_INODE(dir, "checksumming directory "
1461 "block %lu", (unsigned long)block);
1462 brelse(bh);
1463 goto next;
1464 }
1465 set_buffer_verified(bh);
1466 i = search_dirblock(bh, dir, &fname, d_name,
1467 block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
1468 if (i == 1) {
1469 EXT4_I(dir)->i_dir_start_lookup = block;
1470 ret = bh;
1471 goto cleanup_and_exit;
1472 } else {
1473 brelse(bh);
1474 if (i < 0)
1475 goto cleanup_and_exit;
1476 }
1477 next:
1478 if (++block >= nblocks)
1479 block = 0;
1480 } while (block != start);
1481
1482 /*
1483 * If the directory has grown while we were searching, then
1484 * search the last part of the directory before giving up.
1485 */
1486 block = nblocks;
1487 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1488 if (block < nblocks) {
1489 start = 0;
1490 goto restart;
1491 }
1492
1493cleanup_and_exit:
1494 /* Clean up the read-ahead blocks */
1495 for (; ra_ptr < ra_max; ra_ptr++)
1496 brelse(bh_use[ra_ptr]);
1497 ext4_fname_free_filename(&fname);
1498 return ret;
1499}
1500
1501static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
1502 struct ext4_filename *fname,
1503 struct ext4_dir_entry_2 **res_dir)
1504{
1505 struct super_block * sb = dir->i_sb;
1506 struct dx_frame frames[2], *frame;
1507 const struct qstr *d_name = fname->usr_fname;
1508 struct buffer_head *bh;
1509 ext4_lblk_t block;
1510 int retval;
1511
1512#ifdef CONFIG_EXT4_FS_ENCRYPTION
1513 *res_dir = NULL;
1514#endif
1515 frame = dx_probe(fname, dir, NULL, frames);
1516 if (IS_ERR(frame))
1517 return (struct buffer_head *) frame;
1518 do {
1519 block = dx_get_block(frame->at);
1520 bh = ext4_read_dirblock(dir, block, DIRENT);
1521 if (IS_ERR(bh))
1522 goto errout;
1523
1524 retval = search_dirblock(bh, dir, fname, d_name,
1525 block << EXT4_BLOCK_SIZE_BITS(sb),
1526 res_dir);
1527 if (retval == 1)
1528 goto success;
1529 brelse(bh);
1530 if (retval == -1) {
1531 bh = ERR_PTR(ERR_BAD_DX_DIR);
1532 goto errout;
1533 }
1534
1535 /* Check to see if we should continue to search */
1536 retval = ext4_htree_next_block(dir, fname->hinfo.hash, frame,
1537 frames, NULL);
1538 if (retval < 0) {
1539 ext4_warning_inode(dir,
1540 "error %d reading directory index block",
1541 retval);
1542 bh = ERR_PTR(retval);
1543 goto errout;
1544 }
1545 } while (retval == 1);
1546
1547 bh = NULL;
1548errout:
1549 dxtrace(printk(KERN_DEBUG "%s not found\n", d_name->name));
1550success:
1551 dx_release(frames);
1552 return bh;
1553}
1554
1555static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
1556{
1557 struct inode *inode;
1558 struct ext4_dir_entry_2 *de;
1559 struct buffer_head *bh;
1560
1561 if (ext4_encrypted_inode(dir)) {
1562 int res = ext4_get_encryption_info(dir);
1563
1564 /*
1565 * This should be a properly defined flag for
1566 * dentry->d_flags when we uplift this to the VFS.
1567 * d_fsdata is set to (void *) 1 if if the dentry is
1568 * created while the directory was encrypted and we
1569 * don't have access to the key.
1570 */
1571 dentry->d_fsdata = NULL;
1572 if (ext4_encryption_info(dir))
1573 dentry->d_fsdata = (void *) 1;
1574 d_set_d_op(dentry, &ext4_encrypted_d_ops);
1575 if (res && res != -ENOKEY)
1576 return ERR_PTR(res);
1577 }
1578
1579 if (dentry->d_name.len > EXT4_NAME_LEN)
1580 return ERR_PTR(-ENAMETOOLONG);
1581
1582 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
1583 if (IS_ERR(bh))
1584 return (struct dentry *) bh;
1585 inode = NULL;
1586 if (bh) {
1587 __u32 ino = le32_to_cpu(de->inode);
1588 brelse(bh);
1589 if (!ext4_valid_inum(dir->i_sb, ino)) {
1590 EXT4_ERROR_INODE(dir, "bad inode number: %u", ino);
1591 return ERR_PTR(-EFSCORRUPTED);
1592 }
1593 if (unlikely(ino == dir->i_ino)) {
1594 EXT4_ERROR_INODE(dir, "'%pd' linked to parent dir",
1595 dentry);
1596 return ERR_PTR(-EFSCORRUPTED);
1597 }
1598 inode = ext4_iget_normal(dir->i_sb, ino);
1599 if (inode == ERR_PTR(-ESTALE)) {
1600 EXT4_ERROR_INODE(dir,
1601 "deleted inode referenced: %u",
1602 ino);
1603 return ERR_PTR(-EFSCORRUPTED);
1604 }
1605 if (!IS_ERR(inode) && ext4_encrypted_inode(dir) &&
1606 (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) &&
1607 !ext4_is_child_context_consistent_with_parent(dir,
1608 inode)) {
1609 int nokey = ext4_encrypted_inode(inode) &&
1610 !ext4_encryption_info(inode);
1611
1612 iput(inode);
1613 if (nokey)
1614 return ERR_PTR(-ENOKEY);
1615 ext4_warning(inode->i_sb,
1616 "Inconsistent encryption contexts: %lu/%lu\n",
1617 (unsigned long) dir->i_ino,
1618 (unsigned long) inode->i_ino);
1619 return ERR_PTR(-EPERM);
1620 }
1621 }
1622 return d_splice_alias(inode, dentry);
1623}
1624
1625
1626struct dentry *ext4_get_parent(struct dentry *child)
1627{
1628 __u32 ino;
1629 static const struct qstr dotdot = QSTR_INIT("..", 2);
1630 struct ext4_dir_entry_2 * de;
1631 struct buffer_head *bh;
1632
1633 bh = ext4_find_entry(d_inode(child), &dotdot, &de, NULL);
1634 if (IS_ERR(bh))
1635 return (struct dentry *) bh;
1636 if (!bh)
1637 return ERR_PTR(-ENOENT);
1638 ino = le32_to_cpu(de->inode);
1639 brelse(bh);
1640
1641 if (!ext4_valid_inum(d_inode(child)->i_sb, ino)) {
1642 EXT4_ERROR_INODE(d_inode(child),
1643 "bad parent inode number: %u", ino);
1644 return ERR_PTR(-EFSCORRUPTED);
1645 }
1646
1647 return d_obtain_alias(ext4_iget_normal(d_inode(child)->i_sb, ino));
1648}
1649
1650/*
1651 * Move count entries from end of map between two memory locations.
1652 * Returns pointer to last entry moved.
1653 */
1654static struct ext4_dir_entry_2 *
1655dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count,
1656 unsigned blocksize)
1657{
1658 unsigned rec_len = 0;
1659
1660 while (count--) {
1661 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
1662 (from + (map->offs<<2));
1663 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1664 memcpy (to, de, rec_len);
1665 ((struct ext4_dir_entry_2 *) to)->rec_len =
1666 ext4_rec_len_to_disk(rec_len, blocksize);
1667 de->inode = 0;
1668 map++;
1669 to += rec_len;
1670 }
1671 return (struct ext4_dir_entry_2 *) (to - rec_len);
1672}
1673
1674/*
1675 * Compact each dir entry in the range to the minimal rec_len.
1676 * Returns pointer to last entry in range.
1677 */
1678static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize)
1679{
1680 struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
1681 unsigned rec_len = 0;
1682
1683 prev = to = de;
1684 while ((char*)de < base + blocksize) {
1685 next = ext4_next_entry(de, blocksize);
1686 if (de->inode && de->name_len) {
1687 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1688 if (de > to)
1689 memmove(to, de, rec_len);
1690 to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
1691 prev = to;
1692 to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
1693 }
1694 de = next;
1695 }
1696 return prev;
1697}
1698
1699/*
1700 * Split a full leaf block to make room for a new dir entry.
1701 * Allocate a new block, and move entries so that they are approx. equally full.
1702 * Returns pointer to de in block into which the new entry will be inserted.
1703 */
1704static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
1705 struct buffer_head **bh,struct dx_frame *frame,
1706 struct dx_hash_info *hinfo)
1707{
1708 unsigned blocksize = dir->i_sb->s_blocksize;
1709 unsigned count, continued;
1710 struct buffer_head *bh2;
1711 ext4_lblk_t newblock;
1712 u32 hash2;
1713 struct dx_map_entry *map;
1714 char *data1 = (*bh)->b_data, *data2;
1715 unsigned split, move, size;
1716 struct ext4_dir_entry_2 *de = NULL, *de2;
1717 struct ext4_dir_entry_tail *t;
1718 int csum_size = 0;
1719 int err = 0, i;
1720
1721 if (ext4_has_metadata_csum(dir->i_sb))
1722 csum_size = sizeof(struct ext4_dir_entry_tail);
1723
1724 bh2 = ext4_append(handle, dir, &newblock);
1725 if (IS_ERR(bh2)) {
1726 brelse(*bh);
1727 *bh = NULL;
1728 return (struct ext4_dir_entry_2 *) bh2;
1729 }
1730
1731 BUFFER_TRACE(*bh, "get_write_access");
1732 err = ext4_journal_get_write_access(handle, *bh);
1733 if (err)
1734 goto journal_error;
1735
1736 BUFFER_TRACE(frame->bh, "get_write_access");
1737 err = ext4_journal_get_write_access(handle, frame->bh);
1738 if (err)
1739 goto journal_error;
1740
1741 data2 = bh2->b_data;
1742
1743 /* create map in the end of data2 block */
1744 map = (struct dx_map_entry *) (data2 + blocksize);
1745 count = dx_make_map(dir, (struct ext4_dir_entry_2 *) data1,
1746 blocksize, hinfo, map);
1747 map -= count;
1748 dx_sort_map(map, count);
1749 /* Split the existing block in the middle, size-wise */
1750 size = 0;
1751 move = 0;
1752 for (i = count-1; i >= 0; i--) {
1753 /* is more than half of this entry in 2nd half of the block? */
1754 if (size + map[i].size/2 > blocksize/2)
1755 break;
1756 size += map[i].size;
1757 move++;
1758 }
1759 /* map index at which we will split */
1760 split = count - move;
1761 hash2 = map[split].hash;
1762 continued = hash2 == map[split - 1].hash;
1763 dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
1764 (unsigned long)dx_get_block(frame->at),
1765 hash2, split, count-split));
1766
1767 /* Fancy dance to stay within two buffers */
1768 de2 = dx_move_dirents(data1, data2, map + split, count - split,
1769 blocksize);
1770 de = dx_pack_dirents(data1, blocksize);
1771 de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
1772 (char *) de,
1773 blocksize);
1774 de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
1775 (char *) de2,
1776 blocksize);
1777 if (csum_size) {
1778 t = EXT4_DIRENT_TAIL(data2, blocksize);
1779 initialize_dirent_tail(t, blocksize);
1780
1781 t = EXT4_DIRENT_TAIL(data1, blocksize);
1782 initialize_dirent_tail(t, blocksize);
1783 }
1784
1785 dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data1,
1786 blocksize, 1));
1787 dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data2,
1788 blocksize, 1));
1789
1790 /* Which block gets the new entry? */
1791 if (hinfo->hash >= hash2) {
1792 swap(*bh, bh2);
1793 de = de2;
1794 }
1795 dx_insert_block(frame, hash2 + continued, newblock);
1796 err = ext4_handle_dirty_dirent_node(handle, dir, bh2);
1797 if (err)
1798 goto journal_error;
1799 err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
1800 if (err)
1801 goto journal_error;
1802 brelse(bh2);
1803 dxtrace(dx_show_index("frame", frame->entries));
1804 return de;
1805
1806journal_error:
1807 brelse(*bh);
1808 brelse(bh2);
1809 *bh = NULL;
1810 ext4_std_error(dir->i_sb, err);
1811 return ERR_PTR(err);
1812}
1813
1814int ext4_find_dest_de(struct inode *dir, struct inode *inode,
1815 struct buffer_head *bh,
1816 void *buf, int buf_size,
1817 struct ext4_filename *fname,
1818 struct ext4_dir_entry_2 **dest_de)
1819{
1820 struct ext4_dir_entry_2 *de;
1821 unsigned short reclen = EXT4_DIR_REC_LEN(fname_len(fname));
1822 int nlen, rlen;
1823 unsigned int offset = 0;
1824 char *top;
1825 int res;
1826
1827 de = (struct ext4_dir_entry_2 *)buf;
1828 top = buf + buf_size - reclen;
1829 while ((char *) de <= top) {
1830 if (ext4_check_dir_entry(dir, NULL, de, bh,
1831 buf, buf_size, offset)) {
1832 res = -EFSCORRUPTED;
1833 goto return_result;
1834 }
1835 /* Provide crypto context and crypto buffer to ext4 match */
1836 res = ext4_match(fname, de);
1837 if (res < 0)
1838 goto return_result;
1839 if (res > 0) {
1840 res = -EEXIST;
1841 goto return_result;
1842 }
1843 nlen = EXT4_DIR_REC_LEN(de->name_len);
1844 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
1845 if ((de->inode ? rlen - nlen : rlen) >= reclen)
1846 break;
1847 de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
1848 offset += rlen;
1849 }
1850
1851 if ((char *) de > top)
1852 res = -ENOSPC;
1853 else {
1854 *dest_de = de;
1855 res = 0;
1856 }
1857return_result:
1858 return res;
1859}
1860
1861int ext4_insert_dentry(struct inode *dir,
1862 struct inode *inode,
1863 struct ext4_dir_entry_2 *de,
1864 int buf_size,
1865 struct ext4_filename *fname)
1866{
1867
1868 int nlen, rlen;
1869
1870 nlen = EXT4_DIR_REC_LEN(de->name_len);
1871 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
1872 if (de->inode) {
1873 struct ext4_dir_entry_2 *de1 =
1874 (struct ext4_dir_entry_2 *)((char *)de + nlen);
1875 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, buf_size);
1876 de->rec_len = ext4_rec_len_to_disk(nlen, buf_size);
1877 de = de1;
1878 }
1879 de->file_type = EXT4_FT_UNKNOWN;
1880 de->inode = cpu_to_le32(inode->i_ino);
1881 ext4_set_de_type(inode->i_sb, de, inode->i_mode);
1882 de->name_len = fname_len(fname);
1883 memcpy(de->name, fname_name(fname), fname_len(fname));
1884 return 0;
1885}
1886
1887/*
1888 * Add a new entry into a directory (leaf) block. If de is non-NULL,
1889 * it points to a directory entry which is guaranteed to be large
1890 * enough for new directory entry. If de is NULL, then
1891 * add_dirent_to_buf will attempt search the directory block for
1892 * space. It will return -ENOSPC if no space is available, and -EIO
1893 * and -EEXIST if directory entry already exists.
1894 */
1895static int add_dirent_to_buf(handle_t *handle, struct ext4_filename *fname,
1896 struct inode *dir,
1897 struct inode *inode, struct ext4_dir_entry_2 *de,
1898 struct buffer_head *bh)
1899{
1900 unsigned int blocksize = dir->i_sb->s_blocksize;
1901 int csum_size = 0;
1902 int err;
1903
1904 if (ext4_has_metadata_csum(inode->i_sb))
1905 csum_size = sizeof(struct ext4_dir_entry_tail);
1906
1907 if (!de) {
1908 err = ext4_find_dest_de(dir, inode, bh, bh->b_data,
1909 blocksize - csum_size, fname, &de);
1910 if (err)
1911 return err;
1912 }
1913 BUFFER_TRACE(bh, "get_write_access");
1914 err = ext4_journal_get_write_access(handle, bh);
1915 if (err) {
1916 ext4_std_error(dir->i_sb, err);
1917 return err;
1918 }
1919
1920 /* By now the buffer is marked for journaling. Due to crypto operations,
1921 * the following function call may fail */
1922 err = ext4_insert_dentry(dir, inode, de, blocksize, fname);
1923 if (err < 0)
1924 return err;
1925
1926 /*
1927 * XXX shouldn't update any times until successful
1928 * completion of syscall, but too many callers depend
1929 * on this.
1930 *
1931 * XXX similarly, too many callers depend on
1932 * ext4_new_inode() setting the times, but error
1933 * recovery deletes the inode, so the worst that can
1934 * happen is that the times are slightly out of date
1935 * and/or different from the directory change time.
1936 */
1937 dir->i_mtime = dir->i_ctime = ext4_current_time(dir);
1938 ext4_update_dx_flag(dir);
1939 dir->i_version++;
1940 ext4_mark_inode_dirty(handle, dir);
1941 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1942 err = ext4_handle_dirty_dirent_node(handle, dir, bh);
1943 if (err)
1944 ext4_std_error(dir->i_sb, err);
1945 return 0;
1946}
1947
1948/*
1949 * This converts a one block unindexed directory to a 3 block indexed
1950 * directory, and adds the dentry to the indexed directory.
1951 */
1952static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname,
1953 struct inode *dir,
1954 struct inode *inode, struct buffer_head *bh)
1955{
1956 struct buffer_head *bh2;
1957 struct dx_root *root;
1958 struct dx_frame frames[2], *frame;
1959 struct dx_entry *entries;
1960 struct ext4_dir_entry_2 *de, *de2;
1961 struct ext4_dir_entry_tail *t;
1962 char *data1, *top;
1963 unsigned len;
1964 int retval;
1965 unsigned blocksize;
1966 ext4_lblk_t block;
1967 struct fake_dirent *fde;
1968 int csum_size = 0;
1969
1970 if (ext4_has_metadata_csum(inode->i_sb))
1971 csum_size = sizeof(struct ext4_dir_entry_tail);
1972
1973 blocksize = dir->i_sb->s_blocksize;
1974 dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
1975 BUFFER_TRACE(bh, "get_write_access");
1976 retval = ext4_journal_get_write_access(handle, bh);
1977 if (retval) {
1978 ext4_std_error(dir->i_sb, retval);
1979 brelse(bh);
1980 return retval;
1981 }
1982 root = (struct dx_root *) bh->b_data;
1983
1984 /* The 0th block becomes the root, move the dirents out */
1985 fde = &root->dotdot;
1986 de = (struct ext4_dir_entry_2 *)((char *)fde +
1987 ext4_rec_len_from_disk(fde->rec_len, blocksize));
1988 if ((char *) de >= (((char *) root) + blocksize)) {
1989 EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
1990 brelse(bh);
1991 return -EFSCORRUPTED;
1992 }
1993 len = ((char *) root) + (blocksize - csum_size) - (char *) de;
1994
1995 /* Allocate new block for the 0th block's dirents */
1996 bh2 = ext4_append(handle, dir, &block);
1997 if (IS_ERR(bh2)) {
1998 brelse(bh);
1999 return PTR_ERR(bh2);
2000 }
2001 ext4_set_inode_flag(dir, EXT4_INODE_INDEX);
2002 data1 = bh2->b_data;
2003
2004 memcpy (data1, de, len);
2005 de = (struct ext4_dir_entry_2 *) data1;
2006 top = data1 + len;
2007 while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
2008 de = de2;
2009 de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
2010 (char *) de,
2011 blocksize);
2012
2013 if (csum_size) {
2014 t = EXT4_DIRENT_TAIL(data1, blocksize);
2015 initialize_dirent_tail(t, blocksize);
2016 }
2017
2018 /* Initialize the root; the dot dirents already exist */
2019 de = (struct ext4_dir_entry_2 *) (&root->dotdot);
2020 de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
2021 blocksize);
2022 memset (&root->info, 0, sizeof(root->info));
2023 root->info.info_length = sizeof(root->info);
2024 root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
2025 entries = root->entries;
2026 dx_set_block(entries, 1);
2027 dx_set_count(entries, 1);
2028 dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
2029
2030 /* Initialize as for dx_probe */
2031 fname->hinfo.hash_version = root->info.hash_version;
2032 if (fname->hinfo.hash_version <= DX_HASH_TEA)
2033 fname->hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
2034 fname->hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
2035 ext4fs_dirhash(fname_name(fname), fname_len(fname), &fname->hinfo);
2036
2037 memset(frames, 0, sizeof(frames));
2038 frame = frames;
2039 frame->entries = entries;
2040 frame->at = entries;
2041 frame->bh = bh;
2042 bh = bh2;
2043
2044 retval = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
2045 if (retval)
2046 goto out_frames;
2047 retval = ext4_handle_dirty_dirent_node(handle, dir, bh);
2048 if (retval)
2049 goto out_frames;
2050
2051 de = do_split(handle,dir, &bh, frame, &fname->hinfo);
2052 if (IS_ERR(de)) {
2053 retval = PTR_ERR(de);
2054 goto out_frames;
2055 }
2056 dx_release(frames);
2057
2058 retval = add_dirent_to_buf(handle, fname, dir, inode, de, bh);
2059 brelse(bh);
2060 return retval;
2061out_frames:
2062 /*
2063 * Even if the block split failed, we have to properly write
2064 * out all the changes we did so far. Otherwise we can end up
2065 * with corrupted filesystem.
2066 */
2067 ext4_mark_inode_dirty(handle, dir);
2068 dx_release(frames);
2069 return retval;
2070}
2071
2072/*
2073 * ext4_add_entry()
2074 *
2075 * adds a file entry to the specified directory, using the same
2076 * semantics as ext4_find_entry(). It returns NULL if it failed.
2077 *
2078 * NOTE!! The inode part of 'de' is left at 0 - which means you
2079 * may not sleep between calling this and putting something into
2080 * the entry, as someone else might have used it while you slept.
2081 */
2082static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
2083 struct inode *inode)
2084{
2085 struct inode *dir = d_inode(dentry->d_parent);
2086 struct buffer_head *bh = NULL;
2087 struct ext4_dir_entry_2 *de;
2088 struct ext4_dir_entry_tail *t;
2089 struct super_block *sb;
2090 struct ext4_filename fname;
2091 int retval;
2092 int dx_fallback=0;
2093 unsigned blocksize;
2094 ext4_lblk_t block, blocks;
2095 int csum_size = 0;
2096
2097 if (ext4_has_metadata_csum(inode->i_sb))
2098 csum_size = sizeof(struct ext4_dir_entry_tail);
2099
2100 sb = dir->i_sb;
2101 blocksize = sb->s_blocksize;
2102 if (!dentry->d_name.len)
2103 return -EINVAL;
2104
2105 retval = ext4_fname_setup_filename(dir, &dentry->d_name, 0, &fname);
2106 if (retval)
2107 return retval;
2108
2109 if (ext4_has_inline_data(dir)) {
2110 retval = ext4_try_add_inline_entry(handle, &fname, dir, inode);
2111 if (retval < 0)
2112 goto out;
2113 if (retval == 1) {
2114 retval = 0;
2115 goto out;
2116 }
2117 }
2118
2119 if (is_dx(dir)) {
2120 retval = ext4_dx_add_entry(handle, &fname, dir, inode);
2121 if (!retval || (retval != ERR_BAD_DX_DIR))
2122 goto out;
2123 ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
2124 dx_fallback++;
2125 ext4_mark_inode_dirty(handle, dir);
2126 }
2127 blocks = dir->i_size >> sb->s_blocksize_bits;
2128 for (block = 0; block < blocks; block++) {
2129 bh = ext4_read_dirblock(dir, block, DIRENT);
2130 if (IS_ERR(bh)) {
2131 retval = PTR_ERR(bh);
2132 bh = NULL;
2133 goto out;
2134 }
2135 retval = add_dirent_to_buf(handle, &fname, dir, inode,
2136 NULL, bh);
2137 if (retval != -ENOSPC)
2138 goto out;
2139
2140 if (blocks == 1 && !dx_fallback &&
2141 ext4_has_feature_dir_index(sb)) {
2142 retval = make_indexed_dir(handle, &fname, dir,
2143 inode, bh);
2144 bh = NULL; /* make_indexed_dir releases bh */
2145 goto out;
2146 }
2147 brelse(bh);
2148 }
2149 bh = ext4_append(handle, dir, &block);
2150 if (IS_ERR(bh)) {
2151 retval = PTR_ERR(bh);
2152 bh = NULL;
2153 goto out;
2154 }
2155 de = (struct ext4_dir_entry_2 *) bh->b_data;
2156 de->inode = 0;
2157 de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize);
2158
2159 if (csum_size) {
2160 t = EXT4_DIRENT_TAIL(bh->b_data, blocksize);
2161 initialize_dirent_tail(t, blocksize);
2162 }
2163
2164 retval = add_dirent_to_buf(handle, &fname, dir, inode, de, bh);
2165out:
2166 ext4_fname_free_filename(&fname);
2167 brelse(bh);
2168 if (retval == 0)
2169 ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY);
2170 return retval;
2171}
2172
2173/*
2174 * Returns 0 for success, or a negative error value
2175 */
2176static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
2177 struct inode *dir, struct inode *inode)
2178{
2179 struct dx_frame frames[2], *frame;
2180 struct dx_entry *entries, *at;
2181 struct buffer_head *bh;
2182 struct super_block *sb = dir->i_sb;
2183 struct ext4_dir_entry_2 *de;
2184 int err;
2185
2186 frame = dx_probe(fname, dir, NULL, frames);
2187 if (IS_ERR(frame))
2188 return PTR_ERR(frame);
2189 entries = frame->entries;
2190 at = frame->at;
2191 bh = ext4_read_dirblock(dir, dx_get_block(frame->at), DIRENT);
2192 if (IS_ERR(bh)) {
2193 err = PTR_ERR(bh);
2194 bh = NULL;
2195 goto cleanup;
2196 }
2197
2198 BUFFER_TRACE(bh, "get_write_access");
2199 err = ext4_journal_get_write_access(handle, bh);
2200 if (err)
2201 goto journal_error;
2202
2203 err = add_dirent_to_buf(handle, fname, dir, inode, NULL, bh);
2204 if (err != -ENOSPC)
2205 goto cleanup;
2206
2207 /* Block full, should compress but for now just split */
2208 dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
2209 dx_get_count(entries), dx_get_limit(entries)));
2210 /* Need to split index? */
2211 if (dx_get_count(entries) == dx_get_limit(entries)) {
2212 ext4_lblk_t newblock;
2213 unsigned icount = dx_get_count(entries);
2214 int levels = frame - frames;
2215 struct dx_entry *entries2;
2216 struct dx_node *node2;
2217 struct buffer_head *bh2;
2218
2219 if (levels && (dx_get_count(frames->entries) ==
2220 dx_get_limit(frames->entries))) {
2221 ext4_warning_inode(dir, "Directory index full!");
2222 err = -ENOSPC;
2223 goto cleanup;
2224 }
2225 bh2 = ext4_append(handle, dir, &newblock);
2226 if (IS_ERR(bh2)) {
2227 err = PTR_ERR(bh2);
2228 goto cleanup;
2229 }
2230 node2 = (struct dx_node *)(bh2->b_data);
2231 entries2 = node2->entries;
2232 memset(&node2->fake, 0, sizeof(struct fake_dirent));
2233 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
2234 sb->s_blocksize);
2235 BUFFER_TRACE(frame->bh, "get_write_access");
2236 err = ext4_journal_get_write_access(handle, frame->bh);
2237 if (err)
2238 goto journal_error;
2239 if (levels) {
2240 unsigned icount1 = icount/2, icount2 = icount - icount1;
2241 unsigned hash2 = dx_get_hash(entries + icount1);
2242 dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
2243 icount1, icount2));
2244
2245 BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
2246 err = ext4_journal_get_write_access(handle,
2247 frames[0].bh);
2248 if (err)
2249 goto journal_error;
2250
2251 memcpy((char *) entries2, (char *) (entries + icount1),
2252 icount2 * sizeof(struct dx_entry));
2253 dx_set_count(entries, icount1);
2254 dx_set_count(entries2, icount2);
2255 dx_set_limit(entries2, dx_node_limit(dir));
2256
2257 /* Which index block gets the new entry? */
2258 if (at - entries >= icount1) {
2259 frame->at = at = at - entries - icount1 + entries2;
2260 frame->entries = entries = entries2;
2261 swap(frame->bh, bh2);
2262 }
2263 dx_insert_block(frames + 0, hash2, newblock);
2264 dxtrace(dx_show_index("node", frames[1].entries));
2265 dxtrace(dx_show_index("node",
2266 ((struct dx_node *) bh2->b_data)->entries));
2267 err = ext4_handle_dirty_dx_node(handle, dir, bh2);
2268 if (err)
2269 goto journal_error;
2270 brelse (bh2);
2271 } else {
2272 dxtrace(printk(KERN_DEBUG
2273 "Creating second level index...\n"));
2274 memcpy((char *) entries2, (char *) entries,
2275 icount * sizeof(struct dx_entry));
2276 dx_set_limit(entries2, dx_node_limit(dir));
2277
2278 /* Set up root */
2279 dx_set_count(entries, 1);
2280 dx_set_block(entries + 0, newblock);
2281 ((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels = 1;
2282
2283 /* Add new access path frame */
2284 frame = frames + 1;
2285 frame->at = at = at - entries + entries2;
2286 frame->entries = entries = entries2;
2287 frame->bh = bh2;
2288 err = ext4_journal_get_write_access(handle,
2289 frame->bh);
2290 if (err)
2291 goto journal_error;
2292 }
2293 err = ext4_handle_dirty_dx_node(handle, dir, frames[0].bh);
2294 if (err) {
2295 ext4_std_error(inode->i_sb, err);
2296 goto cleanup;
2297 }
2298 }
2299 de = do_split(handle, dir, &bh, frame, &fname->hinfo);
2300 if (IS_ERR(de)) {
2301 err = PTR_ERR(de);
2302 goto cleanup;
2303 }
2304 err = add_dirent_to_buf(handle, fname, dir, inode, de, bh);
2305 goto cleanup;
2306
2307journal_error:
2308 ext4_std_error(dir->i_sb, err);
2309cleanup:
2310 brelse(bh);
2311 dx_release(frames);
2312 return err;
2313}
2314
2315/*
2316 * ext4_generic_delete_entry deletes a directory entry by merging it
2317 * with the previous entry
2318 */
2319int ext4_generic_delete_entry(handle_t *handle,
2320 struct inode *dir,
2321 struct ext4_dir_entry_2 *de_del,
2322 struct buffer_head *bh,
2323 void *entry_buf,
2324 int buf_size,
2325 int csum_size)
2326{
2327 struct ext4_dir_entry_2 *de, *pde;
2328 unsigned int blocksize = dir->i_sb->s_blocksize;
2329 int i;
2330
2331 i = 0;
2332 pde = NULL;
2333 de = (struct ext4_dir_entry_2 *)entry_buf;
2334 while (i < buf_size - csum_size) {
2335 if (ext4_check_dir_entry(dir, NULL, de, bh,
2336 bh->b_data, bh->b_size, i))
2337 return -EFSCORRUPTED;
2338 if (de == de_del) {
2339 if (pde)
2340 pde->rec_len = ext4_rec_len_to_disk(
2341 ext4_rec_len_from_disk(pde->rec_len,
2342 blocksize) +
2343 ext4_rec_len_from_disk(de->rec_len,
2344 blocksize),
2345 blocksize);
2346 else
2347 de->inode = 0;
2348 dir->i_version++;
2349 return 0;
2350 }
2351 i += ext4_rec_len_from_disk(de->rec_len, blocksize);
2352 pde = de;
2353 de = ext4_next_entry(de, blocksize);
2354 }
2355 return -ENOENT;
2356}
2357
2358static int ext4_delete_entry(handle_t *handle,
2359 struct inode *dir,
2360 struct ext4_dir_entry_2 *de_del,
2361 struct buffer_head *bh)
2362{
2363 int err, csum_size = 0;
2364
2365 if (ext4_has_inline_data(dir)) {
2366 int has_inline_data = 1;
2367 err = ext4_delete_inline_entry(handle, dir, de_del, bh,
2368 &has_inline_data);
2369 if (has_inline_data)
2370 return err;
2371 }
2372
2373 if (ext4_has_metadata_csum(dir->i_sb))
2374 csum_size = sizeof(struct ext4_dir_entry_tail);
2375
2376 BUFFER_TRACE(bh, "get_write_access");
2377 err = ext4_journal_get_write_access(handle, bh);
2378 if (unlikely(err))
2379 goto out;
2380
2381 err = ext4_generic_delete_entry(handle, dir, de_del,
2382 bh, bh->b_data,
2383 dir->i_sb->s_blocksize, csum_size);
2384 if (err)
2385 goto out;
2386
2387 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
2388 err = ext4_handle_dirty_dirent_node(handle, dir, bh);
2389 if (unlikely(err))
2390 goto out;
2391
2392 return 0;
2393out:
2394 if (err != -ENOENT)
2395 ext4_std_error(dir->i_sb, err);
2396 return err;
2397}
2398
2399/*
2400 * DIR_NLINK feature is set if 1) nlinks > EXT4_LINK_MAX or 2) nlinks == 2,
2401 * since this indicates that nlinks count was previously 1.
2402 */
2403static void ext4_inc_count(handle_t *handle, struct inode *inode)
2404{
2405 inc_nlink(inode);
2406 if (is_dx(inode) && inode->i_nlink > 1) {
2407 /* limit is 16-bit i_links_count */
2408 if (inode->i_nlink >= EXT4_LINK_MAX || inode->i_nlink == 2) {
2409 set_nlink(inode, 1);
2410 ext4_set_feature_dir_nlink(inode->i_sb);
2411 }
2412 }
2413}
2414
2415/*
2416 * If a directory had nlink == 1, then we should let it be 1. This indicates
2417 * directory has >EXT4_LINK_MAX subdirs.
2418 */
2419static void ext4_dec_count(handle_t *handle, struct inode *inode)
2420{
2421 if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
2422 drop_nlink(inode);
2423}
2424
2425
2426static int ext4_add_nondir(handle_t *handle,
2427 struct dentry *dentry, struct inode *inode)
2428{
2429 int err = ext4_add_entry(handle, dentry, inode);
2430 if (!err) {
2431 ext4_mark_inode_dirty(handle, inode);
2432 unlock_new_inode(inode);
2433 d_instantiate(dentry, inode);
2434 return 0;
2435 }
2436 drop_nlink(inode);
2437 unlock_new_inode(inode);
2438 iput(inode);
2439 return err;
2440}
2441
2442/*
2443 * By the time this is called, we already have created
2444 * the directory cache entry for the new file, but it
2445 * is so far negative - it has no inode.
2446 *
2447 * If the create succeeds, we fill in the inode information
2448 * with d_instantiate().
2449 */
2450static int ext4_create(struct inode *dir, struct dentry *dentry, umode_t mode,
2451 bool excl)
2452{
2453 handle_t *handle;
2454 struct inode *inode;
2455 int err, credits, retries = 0;
2456
2457 err = dquot_initialize(dir);
2458 if (err)
2459 return err;
2460
2461 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2462 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2463retry:
2464 inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
2465 NULL, EXT4_HT_DIR, credits);
2466 handle = ext4_journal_current_handle();
2467 err = PTR_ERR(inode);
2468 if (!IS_ERR(inode)) {
2469 inode->i_op = &ext4_file_inode_operations;
2470 inode->i_fop = &ext4_file_operations;
2471 ext4_set_aops(inode);
2472 err = ext4_add_nondir(handle, dentry, inode);
2473 if (!err && IS_DIRSYNC(dir))
2474 ext4_handle_sync(handle);
2475 }
2476 if (handle)
2477 ext4_journal_stop(handle);
2478 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2479 goto retry;
2480 return err;
2481}
2482
2483static int ext4_mknod(struct inode *dir, struct dentry *dentry,
2484 umode_t mode, dev_t rdev)
2485{
2486 handle_t *handle;
2487 struct inode *inode;
2488 int err, credits, retries = 0;
2489
2490 err = dquot_initialize(dir);
2491 if (err)
2492 return err;
2493
2494 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2495 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2496retry:
2497 inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
2498 NULL, EXT4_HT_DIR, credits);
2499 handle = ext4_journal_current_handle();
2500 err = PTR_ERR(inode);
2501 if (!IS_ERR(inode)) {
2502 init_special_inode(inode, inode->i_mode, rdev);
2503 inode->i_op = &ext4_special_inode_operations;
2504 err = ext4_add_nondir(handle, dentry, inode);
2505 if (!err && IS_DIRSYNC(dir))
2506 ext4_handle_sync(handle);
2507 }
2508 if (handle)
2509 ext4_journal_stop(handle);
2510 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2511 goto retry;
2512 return err;
2513}
2514
2515static int ext4_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
2516{
2517 handle_t *handle;
2518 struct inode *inode;
2519 int err, retries = 0;
2520
2521 err = dquot_initialize(dir);
2522 if (err)
2523 return err;
2524
2525retry:
2526 inode = ext4_new_inode_start_handle(dir, mode,
2527 NULL, 0, NULL,
2528 EXT4_HT_DIR,
2529 EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
2530 4 + EXT4_XATTR_TRANS_BLOCKS);
2531 handle = ext4_journal_current_handle();
2532 err = PTR_ERR(inode);
2533 if (!IS_ERR(inode)) {
2534 inode->i_op = &ext4_file_inode_operations;
2535 inode->i_fop = &ext4_file_operations;
2536 ext4_set_aops(inode);
2537 d_tmpfile(dentry, inode);
2538 err = ext4_orphan_add(handle, inode);
2539 if (err)
2540 goto err_unlock_inode;
2541 mark_inode_dirty(inode);
2542 unlock_new_inode(inode);
2543 }
2544 if (handle)
2545 ext4_journal_stop(handle);
2546 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2547 goto retry;
2548 return err;
2549err_unlock_inode:
2550 ext4_journal_stop(handle);
2551 unlock_new_inode(inode);
2552 return err;
2553}
2554
2555struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
2556 struct ext4_dir_entry_2 *de,
2557 int blocksize, int csum_size,
2558 unsigned int parent_ino, int dotdot_real_len)
2559{
2560 de->inode = cpu_to_le32(inode->i_ino);
2561 de->name_len = 1;
2562 de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
2563 blocksize);
2564 strcpy(de->name, ".");
2565 ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2566
2567 de = ext4_next_entry(de, blocksize);
2568 de->inode = cpu_to_le32(parent_ino);
2569 de->name_len = 2;
2570 if (!dotdot_real_len)
2571 de->rec_len = ext4_rec_len_to_disk(blocksize -
2572 (csum_size + EXT4_DIR_REC_LEN(1)),
2573 blocksize);
2574 else
2575 de->rec_len = ext4_rec_len_to_disk(
2576 EXT4_DIR_REC_LEN(de->name_len), blocksize);
2577 strcpy(de->name, "..");
2578 ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2579
2580 return ext4_next_entry(de, blocksize);
2581}
2582
2583static int ext4_init_new_dir(handle_t *handle, struct inode *dir,
2584 struct inode *inode)
2585{
2586 struct buffer_head *dir_block = NULL;
2587 struct ext4_dir_entry_2 *de;
2588 struct ext4_dir_entry_tail *t;
2589 ext4_lblk_t block = 0;
2590 unsigned int blocksize = dir->i_sb->s_blocksize;
2591 int csum_size = 0;
2592 int err;
2593
2594 if (ext4_has_metadata_csum(dir->i_sb))
2595 csum_size = sizeof(struct ext4_dir_entry_tail);
2596
2597 if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
2598 err = ext4_try_create_inline_dir(handle, dir, inode);
2599 if (err < 0 && err != -ENOSPC)
2600 goto out;
2601 if (!err)
2602 goto out;
2603 }
2604
2605 inode->i_size = 0;
2606 dir_block = ext4_append(handle, inode, &block);
2607 if (IS_ERR(dir_block))
2608 return PTR_ERR(dir_block);
2609 de = (struct ext4_dir_entry_2 *)dir_block->b_data;
2610 ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0);
2611 set_nlink(inode, 2);
2612 if (csum_size) {
2613 t = EXT4_DIRENT_TAIL(dir_block->b_data, blocksize);
2614 initialize_dirent_tail(t, blocksize);
2615 }
2616
2617 BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
2618 err = ext4_handle_dirty_dirent_node(handle, inode, dir_block);
2619 if (err)
2620 goto out;
2621 set_buffer_verified(dir_block);
2622out:
2623 brelse(dir_block);
2624 return err;
2625}
2626
2627static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
2628{
2629 handle_t *handle;
2630 struct inode *inode;
2631 int err, credits, retries = 0;
2632
2633 if (EXT4_DIR_LINK_MAX(dir))
2634 return -EMLINK;
2635
2636 err = dquot_initialize(dir);
2637 if (err)
2638 return err;
2639
2640 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2641 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2642retry:
2643 inode = ext4_new_inode_start_handle(dir, S_IFDIR | mode,
2644 &dentry->d_name,
2645 0, NULL, EXT4_HT_DIR, credits);
2646 handle = ext4_journal_current_handle();
2647 err = PTR_ERR(inode);
2648 if (IS_ERR(inode))
2649 goto out_stop;
2650
2651 inode->i_op = &ext4_dir_inode_operations;
2652 inode->i_fop = &ext4_dir_operations;
2653 err = ext4_init_new_dir(handle, dir, inode);
2654 if (err)
2655 goto out_clear_inode;
2656 err = ext4_mark_inode_dirty(handle, inode);
2657 if (!err)
2658 err = ext4_add_entry(handle, dentry, inode);
2659 if (err) {
2660out_clear_inode:
2661 clear_nlink(inode);
2662 unlock_new_inode(inode);
2663 ext4_mark_inode_dirty(handle, inode);
2664 iput(inode);
2665 goto out_stop;
2666 }
2667 ext4_inc_count(handle, dir);
2668 ext4_update_dx_flag(dir);
2669 err = ext4_mark_inode_dirty(handle, dir);
2670 if (err)
2671 goto out_clear_inode;
2672 unlock_new_inode(inode);
2673 d_instantiate(dentry, inode);
2674 if (IS_DIRSYNC(dir))
2675 ext4_handle_sync(handle);
2676
2677out_stop:
2678 if (handle)
2679 ext4_journal_stop(handle);
2680 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2681 goto retry;
2682 return err;
2683}
2684
2685/*
2686 * routine to check that the specified directory is empty (for rmdir)
2687 */
2688int ext4_empty_dir(struct inode *inode)
2689{
2690 unsigned int offset;
2691 struct buffer_head *bh;
2692 struct ext4_dir_entry_2 *de, *de1;
2693 struct super_block *sb;
2694 int err = 0;
2695
2696 if (ext4_has_inline_data(inode)) {
2697 int has_inline_data = 1;
2698
2699 err = empty_inline_dir(inode, &has_inline_data);
2700 if (has_inline_data)
2701 return err;
2702 }
2703
2704 sb = inode->i_sb;
2705 if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2)) {
2706 EXT4_ERROR_INODE(inode, "invalid size");
2707 return 1;
2708 }
2709 bh = ext4_read_dirblock(inode, 0, EITHER);
2710 if (IS_ERR(bh))
2711 return 1;
2712
2713 de = (struct ext4_dir_entry_2 *) bh->b_data;
2714 de1 = ext4_next_entry(de, sb->s_blocksize);
2715 if (le32_to_cpu(de->inode) != inode->i_ino ||
2716 le32_to_cpu(de1->inode) == 0 ||
2717 strcmp(".", de->name) || strcmp("..", de1->name)) {
2718 ext4_warning_inode(inode, "directory missing '.' and/or '..'");
2719 brelse(bh);
2720 return 1;
2721 }
2722 offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) +
2723 ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize);
2724 de = ext4_next_entry(de1, sb->s_blocksize);
2725 while (offset < inode->i_size) {
2726 if ((void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
2727 unsigned int lblock;
2728 err = 0;
2729 brelse(bh);
2730 lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb);
2731 bh = ext4_read_dirblock(inode, lblock, EITHER);
2732 if (IS_ERR(bh))
2733 return 1;
2734 de = (struct ext4_dir_entry_2 *) bh->b_data;
2735 }
2736 if (ext4_check_dir_entry(inode, NULL, de, bh,
2737 bh->b_data, bh->b_size, offset)) {
2738 de = (struct ext4_dir_entry_2 *)(bh->b_data +
2739 sb->s_blocksize);
2740 offset = (offset | (sb->s_blocksize - 1)) + 1;
2741 continue;
2742 }
2743 if (le32_to_cpu(de->inode)) {
2744 brelse(bh);
2745 return 0;
2746 }
2747 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
2748 de = ext4_next_entry(de, sb->s_blocksize);
2749 }
2750 brelse(bh);
2751 return 1;
2752}
2753
2754/*
2755 * ext4_orphan_add() links an unlinked or truncated inode into a list of
2756 * such inodes, starting at the superblock, in case we crash before the
2757 * file is closed/deleted, or in case the inode truncate spans multiple
2758 * transactions and the last transaction is not recovered after a crash.
2759 *
2760 * At filesystem recovery time, we walk this list deleting unlinked
2761 * inodes and truncating linked inodes in ext4_orphan_cleanup().
2762 *
2763 * Orphan list manipulation functions must be called under i_mutex unless
2764 * we are just creating the inode or deleting it.
2765 */
2766int ext4_orphan_add(handle_t *handle, struct inode *inode)
2767{
2768 struct super_block *sb = inode->i_sb;
2769 struct ext4_sb_info *sbi = EXT4_SB(sb);
2770 struct ext4_iloc iloc;
2771 int err = 0, rc;
2772 bool dirty = false;
2773
2774 if (!sbi->s_journal || is_bad_inode(inode))
2775 return 0;
2776
2777 WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
2778 !inode_is_locked(inode));
2779 /*
2780 * Exit early if inode already is on orphan list. This is a big speedup
2781 * since we don't have to contend on the global s_orphan_lock.
2782 */
2783 if (!list_empty(&EXT4_I(inode)->i_orphan))
2784 return 0;
2785
2786 /*
2787 * Orphan handling is only valid for files with data blocks
2788 * being truncated, or files being unlinked. Note that we either
2789 * hold i_mutex, or the inode can not be referenced from outside,
2790 * so i_nlink should not be bumped due to race
2791 */
2792 J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2793 S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
2794
2795 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2796 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2797 if (err)
2798 goto out;
2799
2800 err = ext4_reserve_inode_write(handle, inode, &iloc);
2801 if (err)
2802 goto out;
2803
2804 mutex_lock(&sbi->s_orphan_lock);
2805 /*
2806 * Due to previous errors inode may be already a part of on-disk
2807 * orphan list. If so skip on-disk list modification.
2808 */
2809 if (!NEXT_ORPHAN(inode) || NEXT_ORPHAN(inode) >
2810 (le32_to_cpu(sbi->s_es->s_inodes_count))) {
2811 /* Insert this inode at the head of the on-disk orphan list */
2812 NEXT_ORPHAN(inode) = le32_to_cpu(sbi->s_es->s_last_orphan);
2813 sbi->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
2814 dirty = true;
2815 }
2816 list_add(&EXT4_I(inode)->i_orphan, &sbi->s_orphan);
2817 mutex_unlock(&sbi->s_orphan_lock);
2818
2819 if (dirty) {
2820 err = ext4_handle_dirty_super(handle, sb);
2821 rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
2822 if (!err)
2823 err = rc;
2824 if (err) {
2825 /*
2826 * We have to remove inode from in-memory list if
2827 * addition to on disk orphan list failed. Stray orphan
2828 * list entries can cause panics at unmount time.
2829 */
2830 mutex_lock(&sbi->s_orphan_lock);
2831 list_del(&EXT4_I(inode)->i_orphan);
2832 mutex_unlock(&sbi->s_orphan_lock);
2833 }
2834 }
2835 jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
2836 jbd_debug(4, "orphan inode %lu will point to %d\n",
2837 inode->i_ino, NEXT_ORPHAN(inode));
2838out:
2839 ext4_std_error(sb, err);
2840 return err;
2841}
2842
2843/*
2844 * ext4_orphan_del() removes an unlinked or truncated inode from the list
2845 * of such inodes stored on disk, because it is finally being cleaned up.
2846 */
2847int ext4_orphan_del(handle_t *handle, struct inode *inode)
2848{
2849 struct list_head *prev;
2850 struct ext4_inode_info *ei = EXT4_I(inode);
2851 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2852 __u32 ino_next;
2853 struct ext4_iloc iloc;
2854 int err = 0;
2855
2856 if (!sbi->s_journal && !(sbi->s_mount_state & EXT4_ORPHAN_FS))
2857 return 0;
2858
2859 WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
2860 !inode_is_locked(inode));
2861 /* Do this quick check before taking global s_orphan_lock. */
2862 if (list_empty(&ei->i_orphan))
2863 return 0;
2864
2865 if (handle) {
2866 /* Grab inode buffer early before taking global s_orphan_lock */
2867 err = ext4_reserve_inode_write(handle, inode, &iloc);
2868 }
2869
2870 mutex_lock(&sbi->s_orphan_lock);
2871 jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
2872
2873 prev = ei->i_orphan.prev;
2874 list_del_init(&ei->i_orphan);
2875
2876 /* If we're on an error path, we may not have a valid
2877 * transaction handle with which to update the orphan list on
2878 * disk, but we still need to remove the inode from the linked
2879 * list in memory. */
2880 if (!handle || err) {
2881 mutex_unlock(&sbi->s_orphan_lock);
2882 goto out_err;
2883 }
2884
2885 ino_next = NEXT_ORPHAN(inode);
2886 if (prev == &sbi->s_orphan) {
2887 jbd_debug(4, "superblock will point to %u\n", ino_next);
2888 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2889 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2890 if (err) {
2891 mutex_unlock(&sbi->s_orphan_lock);
2892 goto out_brelse;
2893 }
2894 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
2895 mutex_unlock(&sbi->s_orphan_lock);
2896 err = ext4_handle_dirty_super(handle, inode->i_sb);
2897 } else {
2898 struct ext4_iloc iloc2;
2899 struct inode *i_prev =
2900 &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
2901
2902 jbd_debug(4, "orphan inode %lu will point to %u\n",
2903 i_prev->i_ino, ino_next);
2904 err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
2905 if (err) {
2906 mutex_unlock(&sbi->s_orphan_lock);
2907 goto out_brelse;
2908 }
2909 NEXT_ORPHAN(i_prev) = ino_next;
2910 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
2911 mutex_unlock(&sbi->s_orphan_lock);
2912 }
2913 if (err)
2914 goto out_brelse;
2915 NEXT_ORPHAN(inode) = 0;
2916 err = ext4_mark_iloc_dirty(handle, inode, &iloc);
2917out_err:
2918 ext4_std_error(inode->i_sb, err);
2919 return err;
2920
2921out_brelse:
2922 brelse(iloc.bh);
2923 goto out_err;
2924}
2925
2926static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
2927{
2928 int retval;
2929 struct inode *inode;
2930 struct buffer_head *bh;
2931 struct ext4_dir_entry_2 *de;
2932 handle_t *handle = NULL;
2933
2934 /* Initialize quotas before so that eventual writes go in
2935 * separate transaction */
2936 retval = dquot_initialize(dir);
2937 if (retval)
2938 return retval;
2939 retval = dquot_initialize(d_inode(dentry));
2940 if (retval)
2941 return retval;
2942
2943 retval = -ENOENT;
2944 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
2945 if (IS_ERR(bh))
2946 return PTR_ERR(bh);
2947 if (!bh)
2948 goto end_rmdir;
2949
2950 inode = d_inode(dentry);
2951
2952 retval = -EFSCORRUPTED;
2953 if (le32_to_cpu(de->inode) != inode->i_ino)
2954 goto end_rmdir;
2955
2956 retval = -ENOTEMPTY;
2957 if (!ext4_empty_dir(inode))
2958 goto end_rmdir;
2959
2960 handle = ext4_journal_start(dir, EXT4_HT_DIR,
2961 EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
2962 if (IS_ERR(handle)) {
2963 retval = PTR_ERR(handle);
2964 handle = NULL;
2965 goto end_rmdir;
2966 }
2967
2968 if (IS_DIRSYNC(dir))
2969 ext4_handle_sync(handle);
2970
2971 retval = ext4_delete_entry(handle, dir, de, bh);
2972 if (retval)
2973 goto end_rmdir;
2974 if (!EXT4_DIR_LINK_EMPTY(inode))
2975 ext4_warning_inode(inode,
2976 "empty directory '%.*s' has too many links (%u)",
2977 dentry->d_name.len, dentry->d_name.name,
2978 inode->i_nlink);
2979 inode->i_version++;
2980 clear_nlink(inode);
2981 /* There's no need to set i_disksize: the fact that i_nlink is
2982 * zero will ensure that the right thing happens during any
2983 * recovery. */
2984 inode->i_size = 0;
2985 ext4_orphan_add(handle, inode);
2986 inode->i_ctime = dir->i_ctime = dir->i_mtime = ext4_current_time(inode);
2987 ext4_mark_inode_dirty(handle, inode);
2988 ext4_dec_count(handle, dir);
2989 ext4_update_dx_flag(dir);
2990 ext4_mark_inode_dirty(handle, dir);
2991
2992end_rmdir:
2993 brelse(bh);
2994 if (handle)
2995 ext4_journal_stop(handle);
2996 return retval;
2997}
2998
2999static int ext4_unlink(struct inode *dir, struct dentry *dentry)
3000{
3001 int retval;
3002 struct inode *inode;
3003 struct buffer_head *bh;
3004 struct ext4_dir_entry_2 *de;
3005 handle_t *handle = NULL;
3006
3007 trace_ext4_unlink_enter(dir, dentry);
3008 /* Initialize quotas before so that eventual writes go
3009 * in separate transaction */
3010 retval = dquot_initialize(dir);
3011 if (retval)
3012 return retval;
3013 retval = dquot_initialize(d_inode(dentry));
3014 if (retval)
3015 return retval;
3016
3017 retval = -ENOENT;
3018 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
3019 if (IS_ERR(bh))
3020 return PTR_ERR(bh);
3021 if (!bh)
3022 goto end_unlink;
3023
3024 inode = d_inode(dentry);
3025
3026 retval = -EFSCORRUPTED;
3027 if (le32_to_cpu(de->inode) != inode->i_ino)
3028 goto end_unlink;
3029
3030 handle = ext4_journal_start(dir, EXT4_HT_DIR,
3031 EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
3032 if (IS_ERR(handle)) {
3033 retval = PTR_ERR(handle);
3034 handle = NULL;
3035 goto end_unlink;
3036 }
3037
3038 if (IS_DIRSYNC(dir))
3039 ext4_handle_sync(handle);
3040
3041 if (inode->i_nlink == 0) {
3042 ext4_warning_inode(inode, "Deleting file '%.*s' with no links",
3043 dentry->d_name.len, dentry->d_name.name);
3044 set_nlink(inode, 1);
3045 }
3046 retval = ext4_delete_entry(handle, dir, de, bh);
3047 if (retval)
3048 goto end_unlink;
3049 dir->i_ctime = dir->i_mtime = ext4_current_time(dir);
3050 ext4_update_dx_flag(dir);
3051 ext4_mark_inode_dirty(handle, dir);
3052 drop_nlink(inode);
3053 if (!inode->i_nlink)
3054 ext4_orphan_add(handle, inode);
3055 inode->i_ctime = ext4_current_time(inode);
3056 ext4_mark_inode_dirty(handle, inode);
3057
3058end_unlink:
3059 brelse(bh);
3060 if (handle)
3061 ext4_journal_stop(handle);
3062 trace_ext4_unlink_exit(dentry, retval);
3063 return retval;
3064}
3065
3066static int ext4_symlink(struct inode *dir,
3067 struct dentry *dentry, const char *symname)
3068{
3069 handle_t *handle;
3070 struct inode *inode;
3071 int err, len = strlen(symname);
3072 int credits;
3073 bool encryption_required;
3074 struct ext4_str disk_link;
3075 struct ext4_encrypted_symlink_data *sd = NULL;
3076
3077 disk_link.len = len + 1;
3078 disk_link.name = (char *) symname;
3079
3080 encryption_required = (ext4_encrypted_inode(dir) ||
3081 DUMMY_ENCRYPTION_ENABLED(EXT4_SB(dir->i_sb)));
3082 if (encryption_required) {
3083 err = ext4_get_encryption_info(dir);
3084 if (err)
3085 return err;
3086 if (ext4_encryption_info(dir) == NULL)
3087 return -EPERM;
3088 disk_link.len = (ext4_fname_encrypted_size(dir, len) +
3089 sizeof(struct ext4_encrypted_symlink_data));
3090 sd = kzalloc(disk_link.len, GFP_KERNEL);
3091 if (!sd)
3092 return -ENOMEM;
3093 }
3094
3095 if (disk_link.len > dir->i_sb->s_blocksize) {
3096 err = -ENAMETOOLONG;
3097 goto err_free_sd;
3098 }
3099
3100 err = dquot_initialize(dir);
3101 if (err)
3102 goto err_free_sd;
3103
3104 if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
3105 /*
3106 * For non-fast symlinks, we just allocate inode and put it on
3107 * orphan list in the first transaction => we need bitmap,
3108 * group descriptor, sb, inode block, quota blocks, and
3109 * possibly selinux xattr blocks.
3110 */
3111 credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
3112 EXT4_XATTR_TRANS_BLOCKS;
3113 } else {
3114 /*
3115 * Fast symlink. We have to add entry to directory
3116 * (EXT4_DATA_TRANS_BLOCKS + EXT4_INDEX_EXTRA_TRANS_BLOCKS),
3117 * allocate new inode (bitmap, group descriptor, inode block,
3118 * quota blocks, sb is already counted in previous macros).
3119 */
3120 credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3121 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3;
3122 }
3123
3124 inode = ext4_new_inode_start_handle(dir, S_IFLNK|S_IRWXUGO,
3125 &dentry->d_name, 0, NULL,
3126 EXT4_HT_DIR, credits);
3127 handle = ext4_journal_current_handle();
3128 if (IS_ERR(inode)) {
3129 if (handle)
3130 ext4_journal_stop(handle);
3131 err = PTR_ERR(inode);
3132 goto err_free_sd;
3133 }
3134
3135 if (encryption_required) {
3136 struct qstr istr;
3137 struct ext4_str ostr;
3138
3139 istr.name = (const unsigned char *) symname;
3140 istr.len = len;
3141 ostr.name = sd->encrypted_path;
3142 ostr.len = disk_link.len;
3143 err = ext4_fname_usr_to_disk(inode, &istr, &ostr);
3144 if (err < 0)
3145 goto err_drop_inode;
3146 sd->len = cpu_to_le16(ostr.len);
3147 disk_link.name = (char *) sd;
3148 inode->i_op = &ext4_encrypted_symlink_inode_operations;
3149 }
3150
3151 if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
3152 if (!encryption_required)
3153 inode->i_op = &ext4_symlink_inode_operations;
3154 inode_nohighmem(inode);
3155 ext4_set_aops(inode);
3156 /*
3157 * We cannot call page_symlink() with transaction started
3158 * because it calls into ext4_write_begin() which can wait
3159 * for transaction commit if we are running out of space
3160 * and thus we deadlock. So we have to stop transaction now
3161 * and restart it when symlink contents is written.
3162 *
3163 * To keep fs consistent in case of crash, we have to put inode
3164 * to orphan list in the mean time.
3165 */
3166 drop_nlink(inode);
3167 err = ext4_orphan_add(handle, inode);
3168 ext4_journal_stop(handle);
3169 handle = NULL;
3170 if (err)
3171 goto err_drop_inode;
3172 err = __page_symlink(inode, disk_link.name, disk_link.len, 1);
3173 if (err)
3174 goto err_drop_inode;
3175 /*
3176 * Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS
3177 * + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified
3178 */
3179 handle = ext4_journal_start(dir, EXT4_HT_DIR,
3180 EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3181 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1);
3182 if (IS_ERR(handle)) {
3183 err = PTR_ERR(handle);
3184 handle = NULL;
3185 goto err_drop_inode;
3186 }
3187 set_nlink(inode, 1);
3188 err = ext4_orphan_del(handle, inode);
3189 if (err)
3190 goto err_drop_inode;
3191 } else {
3192 /* clear the extent format for fast symlink */
3193 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
3194 if (!encryption_required) {
3195 inode->i_op = &ext4_fast_symlink_inode_operations;
3196 inode->i_link = (char *)&EXT4_I(inode)->i_data;
3197 }
3198 memcpy((char *)&EXT4_I(inode)->i_data, disk_link.name,
3199 disk_link.len);
3200 inode->i_size = disk_link.len - 1;
3201 }
3202 EXT4_I(inode)->i_disksize = inode->i_size;
3203 err = ext4_add_nondir(handle, dentry, inode);
3204 if (!err && IS_DIRSYNC(dir))
3205 ext4_handle_sync(handle);
3206
3207 if (handle)
3208 ext4_journal_stop(handle);
3209 kfree(sd);
3210 return err;
3211err_drop_inode:
3212 if (handle)
3213 ext4_journal_stop(handle);
3214 clear_nlink(inode);
3215 unlock_new_inode(inode);
3216 iput(inode);
3217err_free_sd:
3218 kfree(sd);
3219 return err;
3220}
3221
3222static int ext4_link(struct dentry *old_dentry,
3223 struct inode *dir, struct dentry *dentry)
3224{
3225 handle_t *handle;
3226 struct inode *inode = d_inode(old_dentry);
3227 int err, retries = 0;
3228
3229 if (inode->i_nlink >= EXT4_LINK_MAX)
3230 return -EMLINK;
3231 if (ext4_encrypted_inode(dir) &&
3232 !ext4_is_child_context_consistent_with_parent(dir, inode))
3233 return -EPERM;
3234
3235 if ((ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT)) &&
3236 (!projid_eq(EXT4_I(dir)->i_projid,
3237 EXT4_I(old_dentry->d_inode)->i_projid)))
3238 return -EXDEV;
3239
3240 err = dquot_initialize(dir);
3241 if (err)
3242 return err;
3243
3244retry:
3245 handle = ext4_journal_start(dir, EXT4_HT_DIR,
3246 (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3247 EXT4_INDEX_EXTRA_TRANS_BLOCKS) + 1);
3248 if (IS_ERR(handle))
3249 return PTR_ERR(handle);
3250
3251 if (IS_DIRSYNC(dir))
3252 ext4_handle_sync(handle);
3253
3254 inode->i_ctime = ext4_current_time(inode);
3255 ext4_inc_count(handle, inode);
3256 ihold(inode);
3257
3258 err = ext4_add_entry(handle, dentry, inode);
3259 if (!err) {
3260 ext4_mark_inode_dirty(handle, inode);
3261 /* this can happen only for tmpfile being
3262 * linked the first time
3263 */
3264 if (inode->i_nlink == 1)
3265 ext4_orphan_del(handle, inode);
3266 d_instantiate(dentry, inode);
3267 } else {
3268 drop_nlink(inode);
3269 iput(inode);
3270 }
3271 ext4_journal_stop(handle);
3272 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
3273 goto retry;
3274 return err;
3275}
3276
3277
3278/*
3279 * Try to find buffer head where contains the parent block.
3280 * It should be the inode block if it is inlined or the 1st block
3281 * if it is a normal dir.
3282 */
3283static struct buffer_head *ext4_get_first_dir_block(handle_t *handle,
3284 struct inode *inode,
3285 int *retval,
3286 struct ext4_dir_entry_2 **parent_de,
3287 int *inlined)
3288{
3289 struct buffer_head *bh;
3290
3291 if (!ext4_has_inline_data(inode)) {
3292 bh = ext4_read_dirblock(inode, 0, EITHER);
3293 if (IS_ERR(bh)) {
3294 *retval = PTR_ERR(bh);
3295 return NULL;
3296 }
3297 *parent_de = ext4_next_entry(
3298 (struct ext4_dir_entry_2 *)bh->b_data,
3299 inode->i_sb->s_blocksize);
3300 return bh;
3301 }
3302
3303 *inlined = 1;
3304 return ext4_get_first_inline_block(inode, parent_de, retval);
3305}
3306
3307struct ext4_renament {
3308 struct inode *dir;
3309 struct dentry *dentry;
3310 struct inode *inode;
3311 bool is_dir;
3312 int dir_nlink_delta;
3313
3314 /* entry for "dentry" */
3315 struct buffer_head *bh;
3316 struct ext4_dir_entry_2 *de;
3317 int inlined;
3318
3319 /* entry for ".." in inode if it's a directory */
3320 struct buffer_head *dir_bh;
3321 struct ext4_dir_entry_2 *parent_de;
3322 int dir_inlined;
3323};
3324
3325static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent)
3326{
3327 int retval;
3328
3329 ent->dir_bh = ext4_get_first_dir_block(handle, ent->inode,
3330 &retval, &ent->parent_de,
3331 &ent->dir_inlined);
3332 if (!ent->dir_bh)
3333 return retval;
3334 if (le32_to_cpu(ent->parent_de->inode) != ent->dir->i_ino)
3335 return -EFSCORRUPTED;
3336 BUFFER_TRACE(ent->dir_bh, "get_write_access");
3337 return ext4_journal_get_write_access(handle, ent->dir_bh);
3338}
3339
3340static int ext4_rename_dir_finish(handle_t *handle, struct ext4_renament *ent,
3341 unsigned dir_ino)
3342{
3343 int retval;
3344
3345 ent->parent_de->inode = cpu_to_le32(dir_ino);
3346 BUFFER_TRACE(ent->dir_bh, "call ext4_handle_dirty_metadata");
3347 if (!ent->dir_inlined) {
3348 if (is_dx(ent->inode)) {
3349 retval = ext4_handle_dirty_dx_node(handle,
3350 ent->inode,
3351 ent->dir_bh);
3352 } else {
3353 retval = ext4_handle_dirty_dirent_node(handle,
3354 ent->inode,
3355 ent->dir_bh);
3356 }
3357 } else {
3358 retval = ext4_mark_inode_dirty(handle, ent->inode);
3359 }
3360 if (retval) {
3361 ext4_std_error(ent->dir->i_sb, retval);
3362 return retval;
3363 }
3364 return 0;
3365}
3366
3367static int ext4_setent(handle_t *handle, struct ext4_renament *ent,
3368 unsigned ino, unsigned file_type)
3369{
3370 int retval;
3371
3372 BUFFER_TRACE(ent->bh, "get write access");
3373 retval = ext4_journal_get_write_access(handle, ent->bh);
3374 if (retval)
3375 return retval;
3376 ent->de->inode = cpu_to_le32(ino);
3377 if (ext4_has_feature_filetype(ent->dir->i_sb))
3378 ent->de->file_type = file_type;
3379 ent->dir->i_version++;
3380 ent->dir->i_ctime = ent->dir->i_mtime =
3381 ext4_current_time(ent->dir);
3382 ext4_mark_inode_dirty(handle, ent->dir);
3383 BUFFER_TRACE(ent->bh, "call ext4_handle_dirty_metadata");
3384 if (!ent->inlined) {
3385 retval = ext4_handle_dirty_dirent_node(handle,
3386 ent->dir, ent->bh);
3387 if (unlikely(retval)) {
3388 ext4_std_error(ent->dir->i_sb, retval);
3389 return retval;
3390 }
3391 }
3392 brelse(ent->bh);
3393 ent->bh = NULL;
3394
3395 return 0;
3396}
3397
3398static int ext4_find_delete_entry(handle_t *handle, struct inode *dir,
3399 const struct qstr *d_name)
3400{
3401 int retval = -ENOENT;
3402 struct buffer_head *bh;
3403 struct ext4_dir_entry_2 *de;
3404
3405 bh = ext4_find_entry(dir, d_name, &de, NULL);
3406 if (IS_ERR(bh))
3407 return PTR_ERR(bh);
3408 if (bh) {
3409 retval = ext4_delete_entry(handle, dir, de, bh);
3410 brelse(bh);
3411 }
3412 return retval;
3413}
3414
3415static void ext4_rename_delete(handle_t *handle, struct ext4_renament *ent,
3416 int force_reread)
3417{
3418 int retval;
3419 /*
3420 * ent->de could have moved from under us during htree split, so make
3421 * sure that we are deleting the right entry. We might also be pointing
3422 * to a stale entry in the unused part of ent->bh so just checking inum
3423 * and the name isn't enough.
3424 */
3425 if (le32_to_cpu(ent->de->inode) != ent->inode->i_ino ||
3426 ent->de->name_len != ent->dentry->d_name.len ||
3427 strncmp(ent->de->name, ent->dentry->d_name.name,
3428 ent->de->name_len) ||
3429 force_reread) {
3430 retval = ext4_find_delete_entry(handle, ent->dir,
3431 &ent->dentry->d_name);
3432 } else {
3433 retval = ext4_delete_entry(handle, ent->dir, ent->de, ent->bh);
3434 if (retval == -ENOENT) {
3435 retval = ext4_find_delete_entry(handle, ent->dir,
3436 &ent->dentry->d_name);
3437 }
3438 }
3439
3440 if (retval) {
3441 ext4_warning_inode(ent->dir,
3442 "Deleting old file: nlink %d, error=%d",
3443 ent->dir->i_nlink, retval);
3444 }
3445}
3446
3447static void ext4_update_dir_count(handle_t *handle, struct ext4_renament *ent)
3448{
3449 if (ent->dir_nlink_delta) {
3450 if (ent->dir_nlink_delta == -1)
3451 ext4_dec_count(handle, ent->dir);
3452 else
3453 ext4_inc_count(handle, ent->dir);
3454 ext4_mark_inode_dirty(handle, ent->dir);
3455 }
3456}
3457
3458static struct inode *ext4_whiteout_for_rename(struct ext4_renament *ent,
3459 int credits, handle_t **h)
3460{
3461 struct inode *wh;
3462 handle_t *handle;
3463 int retries = 0;
3464
3465 /*
3466 * for inode block, sb block, group summaries,
3467 * and inode bitmap
3468 */
3469 credits += (EXT4_MAXQUOTAS_TRANS_BLOCKS(ent->dir->i_sb) +
3470 EXT4_XATTR_TRANS_BLOCKS + 4);
3471retry:
3472 wh = ext4_new_inode_start_handle(ent->dir, S_IFCHR | WHITEOUT_MODE,
3473 &ent->dentry->d_name, 0, NULL,
3474 EXT4_HT_DIR, credits);
3475
3476 handle = ext4_journal_current_handle();
3477 if (IS_ERR(wh)) {
3478 if (handle)
3479 ext4_journal_stop(handle);
3480 if (PTR_ERR(wh) == -ENOSPC &&
3481 ext4_should_retry_alloc(ent->dir->i_sb, &retries))
3482 goto retry;
3483 } else {
3484 *h = handle;
3485 init_special_inode(wh, wh->i_mode, WHITEOUT_DEV);
3486 wh->i_op = &ext4_special_inode_operations;
3487 }
3488 return wh;
3489}
3490
3491/*
3492 * Anybody can rename anything with this: the permission checks are left to the
3493 * higher-level routines.
3494 *
3495 * n.b. old_{dentry,inode) refers to the source dentry/inode
3496 * while new_{dentry,inode) refers to the destination dentry/inode
3497 * This comes from rename(const char *oldpath, const char *newpath)
3498 */
3499static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
3500 struct inode *new_dir, struct dentry *new_dentry,
3501 unsigned int flags)
3502{
3503 handle_t *handle = NULL;
3504 struct ext4_renament old = {
3505 .dir = old_dir,
3506 .dentry = old_dentry,
3507 .inode = d_inode(old_dentry),
3508 };
3509 struct ext4_renament new = {
3510 .dir = new_dir,
3511 .dentry = new_dentry,
3512 .inode = d_inode(new_dentry),
3513 };
3514 int force_reread;
3515 int retval;
3516 struct inode *whiteout = NULL;
3517 int credits;
3518 u8 old_file_type;
3519
3520 if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT)) &&
3521 (!projid_eq(EXT4_I(new_dir)->i_projid,
3522 EXT4_I(old_dentry->d_inode)->i_projid)))
3523 return -EXDEV;
3524
3525 retval = dquot_initialize(old.dir);
3526 if (retval)
3527 return retval;
3528 retval = dquot_initialize(new.dir);
3529 if (retval)
3530 return retval;
3531
3532 /* Initialize quotas before so that eventual writes go
3533 * in separate transaction */
3534 if (new.inode) {
3535 retval = dquot_initialize(new.inode);
3536 if (retval)
3537 return retval;
3538 }
3539
3540 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, NULL);
3541 if (IS_ERR(old.bh))
3542 return PTR_ERR(old.bh);
3543 /*
3544 * Check for inode number is _not_ due to possible IO errors.
3545 * We might rmdir the source, keep it as pwd of some process
3546 * and merrily kill the link to whatever was created under the
3547 * same name. Goodbye sticky bit ;-<
3548 */
3549 retval = -ENOENT;
3550 if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3551 goto end_rename;
3552
3553 if ((old.dir != new.dir) &&
3554 ext4_encrypted_inode(new.dir) &&
3555 !ext4_is_child_context_consistent_with_parent(new.dir,
3556 old.inode)) {
3557 retval = -EPERM;
3558 goto end_rename;
3559 }
3560
3561 new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
3562 &new.de, &new.inlined);
3563 if (IS_ERR(new.bh)) {
3564 retval = PTR_ERR(new.bh);
3565 new.bh = NULL;
3566 goto end_rename;
3567 }
3568 if (new.bh) {
3569 if (!new.inode) {
3570 brelse(new.bh);
3571 new.bh = NULL;
3572 }
3573 }
3574 if (new.inode && !test_opt(new.dir->i_sb, NO_AUTO_DA_ALLOC))
3575 ext4_alloc_da_blocks(old.inode);
3576
3577 credits = (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3578 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
3579 if (!(flags & RENAME_WHITEOUT)) {
3580 handle = ext4_journal_start(old.dir, EXT4_HT_DIR, credits);
3581 if (IS_ERR(handle)) {
3582 retval = PTR_ERR(handle);
3583 handle = NULL;
3584 goto end_rename;
3585 }
3586 } else {
3587 whiteout = ext4_whiteout_for_rename(&old, credits, &handle);
3588 if (IS_ERR(whiteout)) {
3589 retval = PTR_ERR(whiteout);
3590 whiteout = NULL;
3591 goto end_rename;
3592 }
3593 }
3594
3595 if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3596 ext4_handle_sync(handle);
3597
3598 if (S_ISDIR(old.inode->i_mode)) {
3599 if (new.inode) {
3600 retval = -ENOTEMPTY;
3601 if (!ext4_empty_dir(new.inode))
3602 goto end_rename;
3603 } else {
3604 retval = -EMLINK;
3605 if (new.dir != old.dir && EXT4_DIR_LINK_MAX(new.dir))
3606 goto end_rename;
3607 }
3608 retval = ext4_rename_dir_prepare(handle, &old);
3609 if (retval)
3610 goto end_rename;
3611 }
3612 /*
3613 * If we're renaming a file within an inline_data dir and adding or
3614 * setting the new dirent causes a conversion from inline_data to
3615 * extents/blockmap, we need to force the dirent delete code to
3616 * re-read the directory, or else we end up trying to delete a dirent
3617 * from what is now the extent tree root (or a block map).
3618 */
3619 force_reread = (new.dir->i_ino == old.dir->i_ino &&
3620 ext4_test_inode_flag(new.dir, EXT4_INODE_INLINE_DATA));
3621
3622 old_file_type = old.de->file_type;
3623 if (whiteout) {
3624 /*
3625 * Do this before adding a new entry, so the old entry is sure
3626 * to be still pointing to the valid old entry.
3627 */
3628 retval = ext4_setent(handle, &old, whiteout->i_ino,
3629 EXT4_FT_CHRDEV);
3630 if (retval)
3631 goto end_rename;
3632 ext4_mark_inode_dirty(handle, whiteout);
3633 }
3634 if (!new.bh) {
3635 retval = ext4_add_entry(handle, new.dentry, old.inode);
3636 if (retval)
3637 goto end_rename;
3638 } else {
3639 retval = ext4_setent(handle, &new,
3640 old.inode->i_ino, old_file_type);
3641 if (retval)
3642 goto end_rename;
3643 }
3644 if (force_reread)
3645 force_reread = !ext4_test_inode_flag(new.dir,
3646 EXT4_INODE_INLINE_DATA);
3647
3648 /*
3649 * Like most other Unix systems, set the ctime for inodes on a
3650 * rename.
3651 */
3652 old.inode->i_ctime = ext4_current_time(old.inode);
3653 ext4_mark_inode_dirty(handle, old.inode);
3654
3655 if (!whiteout) {
3656 /*
3657 * ok, that's it
3658 */
3659 ext4_rename_delete(handle, &old, force_reread);
3660 }
3661
3662 if (new.inode) {
3663 ext4_dec_count(handle, new.inode);
3664 new.inode->i_ctime = ext4_current_time(new.inode);
3665 }
3666 old.dir->i_ctime = old.dir->i_mtime = ext4_current_time(old.dir);
3667 ext4_update_dx_flag(old.dir);
3668 if (old.dir_bh) {
3669 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
3670 if (retval)
3671 goto end_rename;
3672
3673 ext4_dec_count(handle, old.dir);
3674 if (new.inode) {
3675 /* checked ext4_empty_dir above, can't have another
3676 * parent, ext4_dec_count() won't work for many-linked
3677 * dirs */
3678 clear_nlink(new.inode);
3679 } else {
3680 ext4_inc_count(handle, new.dir);
3681 ext4_update_dx_flag(new.dir);
3682 ext4_mark_inode_dirty(handle, new.dir);
3683 }
3684 }
3685 ext4_mark_inode_dirty(handle, old.dir);
3686 if (new.inode) {
3687 ext4_mark_inode_dirty(handle, new.inode);
3688 if (!new.inode->i_nlink)
3689 ext4_orphan_add(handle, new.inode);
3690 }
3691 retval = 0;
3692
3693end_rename:
3694 brelse(old.dir_bh);
3695 brelse(old.bh);
3696 brelse(new.bh);
3697 if (whiteout) {
3698 if (retval)
3699 drop_nlink(whiteout);
3700 unlock_new_inode(whiteout);
3701 iput(whiteout);
3702 }
3703 if (handle)
3704 ext4_journal_stop(handle);
3705 return retval;
3706}
3707
3708static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
3709 struct inode *new_dir, struct dentry *new_dentry)
3710{
3711 handle_t *handle = NULL;
3712 struct ext4_renament old = {
3713 .dir = old_dir,
3714 .dentry = old_dentry,
3715 .inode = d_inode(old_dentry),
3716 };
3717 struct ext4_renament new = {
3718 .dir = new_dir,
3719 .dentry = new_dentry,
3720 .inode = d_inode(new_dentry),
3721 };
3722 u8 new_file_type;
3723 int retval;
3724
3725 if ((ext4_encrypted_inode(old_dir) ||
3726 ext4_encrypted_inode(new_dir)) &&
3727 (old_dir != new_dir) &&
3728 (!ext4_is_child_context_consistent_with_parent(new_dir,
3729 old.inode) ||
3730 !ext4_is_child_context_consistent_with_parent(old_dir,
3731 new.inode)))
3732 return -EPERM;
3733
3734 if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT) &&
3735 !projid_eq(EXT4_I(new_dir)->i_projid,
3736 EXT4_I(old_dentry->d_inode)->i_projid)) ||
3737 (ext4_test_inode_flag(old_dir, EXT4_INODE_PROJINHERIT) &&
3738 !projid_eq(EXT4_I(old_dir)->i_projid,
3739 EXT4_I(new_dentry->d_inode)->i_projid)))
3740 return -EXDEV;
3741
3742 retval = dquot_initialize(old.dir);
3743 if (retval)
3744 return retval;
3745 retval = dquot_initialize(new.dir);
3746 if (retval)
3747 return retval;
3748
3749 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name,
3750 &old.de, &old.inlined);
3751 if (IS_ERR(old.bh))
3752 return PTR_ERR(old.bh);
3753 /*
3754 * Check for inode number is _not_ due to possible IO errors.
3755 * We might rmdir the source, keep it as pwd of some process
3756 * and merrily kill the link to whatever was created under the
3757 * same name. Goodbye sticky bit ;-<
3758 */
3759 retval = -ENOENT;
3760 if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3761 goto end_rename;
3762
3763 new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
3764 &new.de, &new.inlined);
3765 if (IS_ERR(new.bh)) {
3766 retval = PTR_ERR(new.bh);
3767 new.bh = NULL;
3768 goto end_rename;
3769 }
3770
3771 /* RENAME_EXCHANGE case: old *and* new must both exist */
3772 if (!new.bh || le32_to_cpu(new.de->inode) != new.inode->i_ino)
3773 goto end_rename;
3774
3775 handle = ext4_journal_start(old.dir, EXT4_HT_DIR,
3776 (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3777 2 * EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2));
3778 if (IS_ERR(handle)) {
3779 retval = PTR_ERR(handle);
3780 handle = NULL;
3781 goto end_rename;
3782 }
3783
3784 if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3785 ext4_handle_sync(handle);
3786
3787 if (S_ISDIR(old.inode->i_mode)) {
3788 old.is_dir = true;
3789 retval = ext4_rename_dir_prepare(handle, &old);
3790 if (retval)
3791 goto end_rename;
3792 }
3793 if (S_ISDIR(new.inode->i_mode)) {
3794 new.is_dir = true;
3795 retval = ext4_rename_dir_prepare(handle, &new);
3796 if (retval)
3797 goto end_rename;
3798 }
3799
3800 /*
3801 * Other than the special case of overwriting a directory, parents'
3802 * nlink only needs to be modified if this is a cross directory rename.
3803 */
3804 if (old.dir != new.dir && old.is_dir != new.is_dir) {
3805 old.dir_nlink_delta = old.is_dir ? -1 : 1;
3806 new.dir_nlink_delta = -old.dir_nlink_delta;
3807 retval = -EMLINK;
3808 if ((old.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(old.dir)) ||
3809 (new.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(new.dir)))
3810 goto end_rename;
3811 }
3812
3813 new_file_type = new.de->file_type;
3814 retval = ext4_setent(handle, &new, old.inode->i_ino, old.de->file_type);
3815 if (retval)
3816 goto end_rename;
3817
3818 retval = ext4_setent(handle, &old, new.inode->i_ino, new_file_type);
3819 if (retval)
3820 goto end_rename;
3821
3822 /*
3823 * Like most other Unix systems, set the ctime for inodes on a
3824 * rename.
3825 */
3826 old.inode->i_ctime = ext4_current_time(old.inode);
3827 new.inode->i_ctime = ext4_current_time(new.inode);
3828 ext4_mark_inode_dirty(handle, old.inode);
3829 ext4_mark_inode_dirty(handle, new.inode);
3830
3831 if (old.dir_bh) {
3832 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
3833 if (retval)
3834 goto end_rename;
3835 }
3836 if (new.dir_bh) {
3837 retval = ext4_rename_dir_finish(handle, &new, old.dir->i_ino);
3838 if (retval)
3839 goto end_rename;
3840 }
3841 ext4_update_dir_count(handle, &old);
3842 ext4_update_dir_count(handle, &new);
3843 retval = 0;
3844
3845end_rename:
3846 brelse(old.dir_bh);
3847 brelse(new.dir_bh);
3848 brelse(old.bh);
3849 brelse(new.bh);
3850 if (handle)
3851 ext4_journal_stop(handle);
3852 return retval;
3853}
3854
3855static int ext4_rename2(struct inode *old_dir, struct dentry *old_dentry,
3856 struct inode *new_dir, struct dentry *new_dentry,
3857 unsigned int flags)
3858{
3859 if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
3860 return -EINVAL;
3861
3862 if (flags & RENAME_EXCHANGE) {
3863 return ext4_cross_rename(old_dir, old_dentry,
3864 new_dir, new_dentry);
3865 }
3866
3867 return ext4_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
3868}
3869
3870/*
3871 * directories can handle most operations...
3872 */
3873const struct inode_operations ext4_dir_inode_operations = {
3874 .create = ext4_create,
3875 .lookup = ext4_lookup,
3876 .link = ext4_link,
3877 .unlink = ext4_unlink,
3878 .symlink = ext4_symlink,
3879 .mkdir = ext4_mkdir,
3880 .rmdir = ext4_rmdir,
3881 .mknod = ext4_mknod,
3882 .tmpfile = ext4_tmpfile,
3883 .rename2 = ext4_rename2,
3884 .setattr = ext4_setattr,
3885 .setxattr = generic_setxattr,
3886 .getxattr = generic_getxattr,
3887 .listxattr = ext4_listxattr,
3888 .removexattr = generic_removexattr,
3889 .get_acl = ext4_get_acl,
3890 .set_acl = ext4_set_acl,
3891 .fiemap = ext4_fiemap,
3892};
3893
3894const struct inode_operations ext4_special_inode_operations = {
3895 .setattr = ext4_setattr,
3896 .setxattr = generic_setxattr,
3897 .getxattr = generic_getxattr,
3898 .listxattr = ext4_listxattr,
3899 .removexattr = generic_removexattr,
3900 .get_acl = ext4_get_acl,
3901 .set_acl = ext4_set_acl,
3902};
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/ext4/namei.c
4 *
5 * Copyright (C) 1992, 1993, 1994, 1995
6 * Remy Card (card@masi.ibp.fr)
7 * Laboratoire MASI - Institut Blaise Pascal
8 * Universite Pierre et Marie Curie (Paris VI)
9 *
10 * from
11 *
12 * linux/fs/minix/namei.c
13 *
14 * Copyright (C) 1991, 1992 Linus Torvalds
15 *
16 * Big-endian to little-endian byte-swapping/bitmaps by
17 * David S. Miller (davem@caip.rutgers.edu), 1995
18 * Directory entry file type support and forward compatibility hooks
19 * for B-tree directories by Theodore Ts'o (tytso@mit.edu), 1998
20 * Hash Tree Directory indexing (c)
21 * Daniel Phillips, 2001
22 * Hash Tree Directory indexing porting
23 * Christopher Li, 2002
24 * Hash Tree Directory indexing cleanup
25 * Theodore Ts'o, 2002
26 */
27
28#include <linux/fs.h>
29#include <linux/pagemap.h>
30#include <linux/time.h>
31#include <linux/fcntl.h>
32#include <linux/stat.h>
33#include <linux/string.h>
34#include <linux/quotaops.h>
35#include <linux/buffer_head.h>
36#include <linux/bio.h>
37#include <linux/iversion.h>
38#include <linux/unicode.h>
39#include "ext4.h"
40#include "ext4_jbd2.h"
41
42#include "xattr.h"
43#include "acl.h"
44
45#include <trace/events/ext4.h>
46/*
47 * define how far ahead to read directories while searching them.
48 */
49#define NAMEI_RA_CHUNKS 2
50#define NAMEI_RA_BLOCKS 4
51#define NAMEI_RA_SIZE (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS)
52
53static struct buffer_head *ext4_append(handle_t *handle,
54 struct inode *inode,
55 ext4_lblk_t *block)
56{
57 struct buffer_head *bh;
58 int err;
59
60 if (unlikely(EXT4_SB(inode->i_sb)->s_max_dir_size_kb &&
61 ((inode->i_size >> 10) >=
62 EXT4_SB(inode->i_sb)->s_max_dir_size_kb)))
63 return ERR_PTR(-ENOSPC);
64
65 *block = inode->i_size >> inode->i_sb->s_blocksize_bits;
66
67 bh = ext4_bread(handle, inode, *block, EXT4_GET_BLOCKS_CREATE);
68 if (IS_ERR(bh))
69 return bh;
70 inode->i_size += inode->i_sb->s_blocksize;
71 EXT4_I(inode)->i_disksize = inode->i_size;
72 BUFFER_TRACE(bh, "get_write_access");
73 err = ext4_journal_get_write_access(handle, bh);
74 if (err) {
75 brelse(bh);
76 ext4_std_error(inode->i_sb, err);
77 return ERR_PTR(err);
78 }
79 return bh;
80}
81
82static int ext4_dx_csum_verify(struct inode *inode,
83 struct ext4_dir_entry *dirent);
84
85/*
86 * Hints to ext4_read_dirblock regarding whether we expect a directory
87 * block being read to be an index block, or a block containing
88 * directory entries (and if the latter, whether it was found via a
89 * logical block in an htree index block). This is used to control
90 * what sort of sanity checkinig ext4_read_dirblock() will do on the
91 * directory block read from the storage device. EITHER will means
92 * the caller doesn't know what kind of directory block will be read,
93 * so no specific verification will be done.
94 */
95typedef enum {
96 EITHER, INDEX, DIRENT, DIRENT_HTREE
97} dirblock_type_t;
98
99#define ext4_read_dirblock(inode, block, type) \
100 __ext4_read_dirblock((inode), (block), (type), __func__, __LINE__)
101
102static struct buffer_head *__ext4_read_dirblock(struct inode *inode,
103 ext4_lblk_t block,
104 dirblock_type_t type,
105 const char *func,
106 unsigned int line)
107{
108 struct buffer_head *bh;
109 struct ext4_dir_entry *dirent;
110 int is_dx_block = 0;
111
112 bh = ext4_bread(NULL, inode, block, 0);
113 if (IS_ERR(bh)) {
114 __ext4_warning(inode->i_sb, func, line,
115 "inode #%lu: lblock %lu: comm %s: "
116 "error %ld reading directory block",
117 inode->i_ino, (unsigned long)block,
118 current->comm, PTR_ERR(bh));
119
120 return bh;
121 }
122 if (!bh && (type == INDEX || type == DIRENT_HTREE)) {
123 ext4_error_inode(inode, func, line, block,
124 "Directory hole found for htree %s block",
125 (type == INDEX) ? "index" : "leaf");
126 return ERR_PTR(-EFSCORRUPTED);
127 }
128 if (!bh)
129 return NULL;
130 dirent = (struct ext4_dir_entry *) bh->b_data;
131 /* Determine whether or not we have an index block */
132 if (is_dx(inode)) {
133 if (block == 0)
134 is_dx_block = 1;
135 else if (ext4_rec_len_from_disk(dirent->rec_len,
136 inode->i_sb->s_blocksize) ==
137 inode->i_sb->s_blocksize)
138 is_dx_block = 1;
139 }
140 if (!is_dx_block && type == INDEX) {
141 ext4_error_inode(inode, func, line, block,
142 "directory leaf block found instead of index block");
143 brelse(bh);
144 return ERR_PTR(-EFSCORRUPTED);
145 }
146 if (!ext4_has_metadata_csum(inode->i_sb) ||
147 buffer_verified(bh))
148 return bh;
149
150 /*
151 * An empty leaf block can get mistaken for a index block; for
152 * this reason, we can only check the index checksum when the
153 * caller is sure it should be an index block.
154 */
155 if (is_dx_block && type == INDEX) {
156 if (ext4_dx_csum_verify(inode, dirent))
157 set_buffer_verified(bh);
158 else {
159 ext4_error_inode(inode, func, line, block,
160 "Directory index failed checksum");
161 brelse(bh);
162 return ERR_PTR(-EFSBADCRC);
163 }
164 }
165 if (!is_dx_block) {
166 if (ext4_dirblock_csum_verify(inode, bh))
167 set_buffer_verified(bh);
168 else {
169 ext4_error_inode(inode, func, line, block,
170 "Directory block failed checksum");
171 brelse(bh);
172 return ERR_PTR(-EFSBADCRC);
173 }
174 }
175 return bh;
176}
177
178#ifndef assert
179#define assert(test) J_ASSERT(test)
180#endif
181
182#ifdef DX_DEBUG
183#define dxtrace(command) command
184#else
185#define dxtrace(command)
186#endif
187
188struct fake_dirent
189{
190 __le32 inode;
191 __le16 rec_len;
192 u8 name_len;
193 u8 file_type;
194};
195
196struct dx_countlimit
197{
198 __le16 limit;
199 __le16 count;
200};
201
202struct dx_entry
203{
204 __le32 hash;
205 __le32 block;
206};
207
208/*
209 * dx_root_info is laid out so that if it should somehow get overlaid by a
210 * dirent the two low bits of the hash version will be zero. Therefore, the
211 * hash version mod 4 should never be 0. Sincerely, the paranoia department.
212 */
213
214struct dx_root
215{
216 struct fake_dirent dot;
217 char dot_name[4];
218 struct fake_dirent dotdot;
219 char dotdot_name[4];
220 struct dx_root_info
221 {
222 __le32 reserved_zero;
223 u8 hash_version;
224 u8 info_length; /* 8 */
225 u8 indirect_levels;
226 u8 unused_flags;
227 }
228 info;
229 struct dx_entry entries[0];
230};
231
232struct dx_node
233{
234 struct fake_dirent fake;
235 struct dx_entry entries[0];
236};
237
238
239struct dx_frame
240{
241 struct buffer_head *bh;
242 struct dx_entry *entries;
243 struct dx_entry *at;
244};
245
246struct dx_map_entry
247{
248 u32 hash;
249 u16 offs;
250 u16 size;
251};
252
253/*
254 * This goes at the end of each htree block.
255 */
256struct dx_tail {
257 u32 dt_reserved;
258 __le32 dt_checksum; /* crc32c(uuid+inum+dirblock) */
259};
260
261static inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
262static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
263static inline unsigned dx_get_hash(struct dx_entry *entry);
264static void dx_set_hash(struct dx_entry *entry, unsigned value);
265static unsigned dx_get_count(struct dx_entry *entries);
266static unsigned dx_get_limit(struct dx_entry *entries);
267static void dx_set_count(struct dx_entry *entries, unsigned value);
268static void dx_set_limit(struct dx_entry *entries, unsigned value);
269static unsigned dx_root_limit(struct inode *dir, unsigned infosize);
270static unsigned dx_node_limit(struct inode *dir);
271static struct dx_frame *dx_probe(struct ext4_filename *fname,
272 struct inode *dir,
273 struct dx_hash_info *hinfo,
274 struct dx_frame *frame);
275static void dx_release(struct dx_frame *frames);
276static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de,
277 unsigned blocksize, struct dx_hash_info *hinfo,
278 struct dx_map_entry map[]);
279static void dx_sort_map(struct dx_map_entry *map, unsigned count);
280static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to,
281 struct dx_map_entry *offsets, int count, unsigned blocksize);
282static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize);
283static void dx_insert_block(struct dx_frame *frame,
284 u32 hash, ext4_lblk_t block);
285static int ext4_htree_next_block(struct inode *dir, __u32 hash,
286 struct dx_frame *frame,
287 struct dx_frame *frames,
288 __u32 *start_hash);
289static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
290 struct ext4_filename *fname,
291 struct ext4_dir_entry_2 **res_dir);
292static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
293 struct inode *dir, struct inode *inode);
294
295/* checksumming functions */
296void ext4_initialize_dirent_tail(struct buffer_head *bh,
297 unsigned int blocksize)
298{
299 struct ext4_dir_entry_tail *t = EXT4_DIRENT_TAIL(bh->b_data, blocksize);
300
301 memset(t, 0, sizeof(struct ext4_dir_entry_tail));
302 t->det_rec_len = ext4_rec_len_to_disk(
303 sizeof(struct ext4_dir_entry_tail), blocksize);
304 t->det_reserved_ft = EXT4_FT_DIR_CSUM;
305}
306
307/* Walk through a dirent block to find a checksum "dirent" at the tail */
308static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode,
309 struct buffer_head *bh)
310{
311 struct ext4_dir_entry_tail *t;
312
313#ifdef PARANOID
314 struct ext4_dir_entry *d, *top;
315
316 d = (struct ext4_dir_entry *)bh->b_data;
317 top = (struct ext4_dir_entry *)(bh->b_data +
318 (EXT4_BLOCK_SIZE(inode->i_sb) -
319 sizeof(struct ext4_dir_entry_tail)));
320 while (d < top && d->rec_len)
321 d = (struct ext4_dir_entry *)(((void *)d) +
322 le16_to_cpu(d->rec_len));
323
324 if (d != top)
325 return NULL;
326
327 t = (struct ext4_dir_entry_tail *)d;
328#else
329 t = EXT4_DIRENT_TAIL(bh->b_data, EXT4_BLOCK_SIZE(inode->i_sb));
330#endif
331
332 if (t->det_reserved_zero1 ||
333 le16_to_cpu(t->det_rec_len) != sizeof(struct ext4_dir_entry_tail) ||
334 t->det_reserved_zero2 ||
335 t->det_reserved_ft != EXT4_FT_DIR_CSUM)
336 return NULL;
337
338 return t;
339}
340
341static __le32 ext4_dirblock_csum(struct inode *inode, void *dirent, int size)
342{
343 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
344 struct ext4_inode_info *ei = EXT4_I(inode);
345 __u32 csum;
346
347 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
348 return cpu_to_le32(csum);
349}
350
351#define warn_no_space_for_csum(inode) \
352 __warn_no_space_for_csum((inode), __func__, __LINE__)
353
354static void __warn_no_space_for_csum(struct inode *inode, const char *func,
355 unsigned int line)
356{
357 __ext4_warning_inode(inode, func, line,
358 "No space for directory leaf checksum. Please run e2fsck -D.");
359}
360
361int ext4_dirblock_csum_verify(struct inode *inode, struct buffer_head *bh)
362{
363 struct ext4_dir_entry_tail *t;
364
365 if (!ext4_has_metadata_csum(inode->i_sb))
366 return 1;
367
368 t = get_dirent_tail(inode, bh);
369 if (!t) {
370 warn_no_space_for_csum(inode);
371 return 0;
372 }
373
374 if (t->det_checksum != ext4_dirblock_csum(inode, bh->b_data,
375 (char *)t - bh->b_data))
376 return 0;
377
378 return 1;
379}
380
381static void ext4_dirblock_csum_set(struct inode *inode,
382 struct buffer_head *bh)
383{
384 struct ext4_dir_entry_tail *t;
385
386 if (!ext4_has_metadata_csum(inode->i_sb))
387 return;
388
389 t = get_dirent_tail(inode, bh);
390 if (!t) {
391 warn_no_space_for_csum(inode);
392 return;
393 }
394
395 t->det_checksum = ext4_dirblock_csum(inode, bh->b_data,
396 (char *)t - bh->b_data);
397}
398
399int ext4_handle_dirty_dirblock(handle_t *handle,
400 struct inode *inode,
401 struct buffer_head *bh)
402{
403 ext4_dirblock_csum_set(inode, bh);
404 return ext4_handle_dirty_metadata(handle, inode, bh);
405}
406
407static struct dx_countlimit *get_dx_countlimit(struct inode *inode,
408 struct ext4_dir_entry *dirent,
409 int *offset)
410{
411 struct ext4_dir_entry *dp;
412 struct dx_root_info *root;
413 int count_offset;
414
415 if (le16_to_cpu(dirent->rec_len) == EXT4_BLOCK_SIZE(inode->i_sb))
416 count_offset = 8;
417 else if (le16_to_cpu(dirent->rec_len) == 12) {
418 dp = (struct ext4_dir_entry *)(((void *)dirent) + 12);
419 if (le16_to_cpu(dp->rec_len) !=
420 EXT4_BLOCK_SIZE(inode->i_sb) - 12)
421 return NULL;
422 root = (struct dx_root_info *)(((void *)dp + 12));
423 if (root->reserved_zero ||
424 root->info_length != sizeof(struct dx_root_info))
425 return NULL;
426 count_offset = 32;
427 } else
428 return NULL;
429
430 if (offset)
431 *offset = count_offset;
432 return (struct dx_countlimit *)(((void *)dirent) + count_offset);
433}
434
435static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent,
436 int count_offset, int count, struct dx_tail *t)
437{
438 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
439 struct ext4_inode_info *ei = EXT4_I(inode);
440 __u32 csum;
441 int size;
442 __u32 dummy_csum = 0;
443 int offset = offsetof(struct dx_tail, dt_checksum);
444
445 size = count_offset + (count * sizeof(struct dx_entry));
446 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
447 csum = ext4_chksum(sbi, csum, (__u8 *)t, offset);
448 csum = ext4_chksum(sbi, csum, (__u8 *)&dummy_csum, sizeof(dummy_csum));
449
450 return cpu_to_le32(csum);
451}
452
453static int ext4_dx_csum_verify(struct inode *inode,
454 struct ext4_dir_entry *dirent)
455{
456 struct dx_countlimit *c;
457 struct dx_tail *t;
458 int count_offset, limit, count;
459
460 if (!ext4_has_metadata_csum(inode->i_sb))
461 return 1;
462
463 c = get_dx_countlimit(inode, dirent, &count_offset);
464 if (!c) {
465 EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D.");
466 return 0;
467 }
468 limit = le16_to_cpu(c->limit);
469 count = le16_to_cpu(c->count);
470 if (count_offset + (limit * sizeof(struct dx_entry)) >
471 EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
472 warn_no_space_for_csum(inode);
473 return 0;
474 }
475 t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
476
477 if (t->dt_checksum != ext4_dx_csum(inode, dirent, count_offset,
478 count, t))
479 return 0;
480 return 1;
481}
482
483static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent)
484{
485 struct dx_countlimit *c;
486 struct dx_tail *t;
487 int count_offset, limit, count;
488
489 if (!ext4_has_metadata_csum(inode->i_sb))
490 return;
491
492 c = get_dx_countlimit(inode, dirent, &count_offset);
493 if (!c) {
494 EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D.");
495 return;
496 }
497 limit = le16_to_cpu(c->limit);
498 count = le16_to_cpu(c->count);
499 if (count_offset + (limit * sizeof(struct dx_entry)) >
500 EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
501 warn_no_space_for_csum(inode);
502 return;
503 }
504 t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
505
506 t->dt_checksum = ext4_dx_csum(inode, dirent, count_offset, count, t);
507}
508
509static inline int ext4_handle_dirty_dx_node(handle_t *handle,
510 struct inode *inode,
511 struct buffer_head *bh)
512{
513 ext4_dx_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
514 return ext4_handle_dirty_metadata(handle, inode, bh);
515}
516
517/*
518 * p is at least 6 bytes before the end of page
519 */
520static inline struct ext4_dir_entry_2 *
521ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
522{
523 return (struct ext4_dir_entry_2 *)((char *)p +
524 ext4_rec_len_from_disk(p->rec_len, blocksize));
525}
526
527/*
528 * Future: use high four bits of block for coalesce-on-delete flags
529 * Mask them off for now.
530 */
531
532static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
533{
534 return le32_to_cpu(entry->block) & 0x0fffffff;
535}
536
537static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
538{
539 entry->block = cpu_to_le32(value);
540}
541
542static inline unsigned dx_get_hash(struct dx_entry *entry)
543{
544 return le32_to_cpu(entry->hash);
545}
546
547static inline void dx_set_hash(struct dx_entry *entry, unsigned value)
548{
549 entry->hash = cpu_to_le32(value);
550}
551
552static inline unsigned dx_get_count(struct dx_entry *entries)
553{
554 return le16_to_cpu(((struct dx_countlimit *) entries)->count);
555}
556
557static inline unsigned dx_get_limit(struct dx_entry *entries)
558{
559 return le16_to_cpu(((struct dx_countlimit *) entries)->limit);
560}
561
562static inline void dx_set_count(struct dx_entry *entries, unsigned value)
563{
564 ((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
565}
566
567static inline void dx_set_limit(struct dx_entry *entries, unsigned value)
568{
569 ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
570}
571
572static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
573{
574 unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
575 EXT4_DIR_REC_LEN(2) - infosize;
576
577 if (ext4_has_metadata_csum(dir->i_sb))
578 entry_space -= sizeof(struct dx_tail);
579 return entry_space / sizeof(struct dx_entry);
580}
581
582static inline unsigned dx_node_limit(struct inode *dir)
583{
584 unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);
585
586 if (ext4_has_metadata_csum(dir->i_sb))
587 entry_space -= sizeof(struct dx_tail);
588 return entry_space / sizeof(struct dx_entry);
589}
590
591/*
592 * Debug
593 */
594#ifdef DX_DEBUG
595static void dx_show_index(char * label, struct dx_entry *entries)
596{
597 int i, n = dx_get_count (entries);
598 printk(KERN_DEBUG "%s index", label);
599 for (i = 0; i < n; i++) {
600 printk(KERN_CONT " %x->%lu",
601 i ? dx_get_hash(entries + i) : 0,
602 (unsigned long)dx_get_block(entries + i));
603 }
604 printk(KERN_CONT "\n");
605}
606
607struct stats
608{
609 unsigned names;
610 unsigned space;
611 unsigned bcount;
612};
613
614static struct stats dx_show_leaf(struct inode *dir,
615 struct dx_hash_info *hinfo,
616 struct ext4_dir_entry_2 *de,
617 int size, int show_names)
618{
619 unsigned names = 0, space = 0;
620 char *base = (char *) de;
621 struct dx_hash_info h = *hinfo;
622
623 printk("names: ");
624 while ((char *) de < base + size)
625 {
626 if (de->inode)
627 {
628 if (show_names)
629 {
630#ifdef CONFIG_FS_ENCRYPTION
631 int len;
632 char *name;
633 struct fscrypt_str fname_crypto_str =
634 FSTR_INIT(NULL, 0);
635 int res = 0;
636
637 name = de->name;
638 len = de->name_len;
639 if (IS_ENCRYPTED(dir))
640 res = fscrypt_get_encryption_info(dir);
641 if (res) {
642 printk(KERN_WARNING "Error setting up"
643 " fname crypto: %d\n", res);
644 }
645 if (!fscrypt_has_encryption_key(dir)) {
646 /* Directory is not encrypted */
647 ext4fs_dirhash(dir, de->name,
648 de->name_len, &h);
649 printk("%*.s:(U)%x.%u ", len,
650 name, h.hash,
651 (unsigned) ((char *) de
652 - base));
653 } else {
654 struct fscrypt_str de_name =
655 FSTR_INIT(name, len);
656
657 /* Directory is encrypted */
658 res = fscrypt_fname_alloc_buffer(
659 dir, len,
660 &fname_crypto_str);
661 if (res)
662 printk(KERN_WARNING "Error "
663 "allocating crypto "
664 "buffer--skipping "
665 "crypto\n");
666 res = fscrypt_fname_disk_to_usr(dir,
667 0, 0, &de_name,
668 &fname_crypto_str);
669 if (res) {
670 printk(KERN_WARNING "Error "
671 "converting filename "
672 "from disk to usr"
673 "\n");
674 name = "??";
675 len = 2;
676 } else {
677 name = fname_crypto_str.name;
678 len = fname_crypto_str.len;
679 }
680 ext4fs_dirhash(dir, de->name,
681 de->name_len, &h);
682 printk("%*.s:(E)%x.%u ", len, name,
683 h.hash, (unsigned) ((char *) de
684 - base));
685 fscrypt_fname_free_buffer(
686 &fname_crypto_str);
687 }
688#else
689 int len = de->name_len;
690 char *name = de->name;
691 ext4fs_dirhash(dir, de->name, de->name_len, &h);
692 printk("%*.s:%x.%u ", len, name, h.hash,
693 (unsigned) ((char *) de - base));
694#endif
695 }
696 space += EXT4_DIR_REC_LEN(de->name_len);
697 names++;
698 }
699 de = ext4_next_entry(de, size);
700 }
701 printk(KERN_CONT "(%i)\n", names);
702 return (struct stats) { names, space, 1 };
703}
704
705struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
706 struct dx_entry *entries, int levels)
707{
708 unsigned blocksize = dir->i_sb->s_blocksize;
709 unsigned count = dx_get_count(entries), names = 0, space = 0, i;
710 unsigned bcount = 0;
711 struct buffer_head *bh;
712 printk("%i indexed blocks...\n", count);
713 for (i = 0; i < count; i++, entries++)
714 {
715 ext4_lblk_t block = dx_get_block(entries);
716 ext4_lblk_t hash = i ? dx_get_hash(entries): 0;
717 u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
718 struct stats stats;
719 printk("%s%3u:%03u hash %8x/%8x ",levels?"":" ", i, block, hash, range);
720 bh = ext4_bread(NULL,dir, block, 0);
721 if (!bh || IS_ERR(bh))
722 continue;
723 stats = levels?
724 dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
725 dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *)
726 bh->b_data, blocksize, 0);
727 names += stats.names;
728 space += stats.space;
729 bcount += stats.bcount;
730 brelse(bh);
731 }
732 if (bcount)
733 printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n",
734 levels ? "" : " ", names, space/bcount,
735 (space/bcount)*100/blocksize);
736 return (struct stats) { names, space, bcount};
737}
738#endif /* DX_DEBUG */
739
740/*
741 * Probe for a directory leaf block to search.
742 *
743 * dx_probe can return ERR_BAD_DX_DIR, which means there was a format
744 * error in the directory index, and the caller should fall back to
745 * searching the directory normally. The callers of dx_probe **MUST**
746 * check for this error code, and make sure it never gets reflected
747 * back to userspace.
748 */
749static struct dx_frame *
750dx_probe(struct ext4_filename *fname, struct inode *dir,
751 struct dx_hash_info *hinfo, struct dx_frame *frame_in)
752{
753 unsigned count, indirect;
754 struct dx_entry *at, *entries, *p, *q, *m;
755 struct dx_root *root;
756 struct dx_frame *frame = frame_in;
757 struct dx_frame *ret_err = ERR_PTR(ERR_BAD_DX_DIR);
758 u32 hash;
759
760 memset(frame_in, 0, EXT4_HTREE_LEVEL * sizeof(frame_in[0]));
761 frame->bh = ext4_read_dirblock(dir, 0, INDEX);
762 if (IS_ERR(frame->bh))
763 return (struct dx_frame *) frame->bh;
764
765 root = (struct dx_root *) frame->bh->b_data;
766 if (root->info.hash_version != DX_HASH_TEA &&
767 root->info.hash_version != DX_HASH_HALF_MD4 &&
768 root->info.hash_version != DX_HASH_LEGACY) {
769 ext4_warning_inode(dir, "Unrecognised inode hash code %u",
770 root->info.hash_version);
771 goto fail;
772 }
773 if (fname)
774 hinfo = &fname->hinfo;
775 hinfo->hash_version = root->info.hash_version;
776 if (hinfo->hash_version <= DX_HASH_TEA)
777 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
778 hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
779 if (fname && fname_name(fname))
780 ext4fs_dirhash(dir, fname_name(fname), fname_len(fname), hinfo);
781 hash = hinfo->hash;
782
783 if (root->info.unused_flags & 1) {
784 ext4_warning_inode(dir, "Unimplemented hash flags: %#06x",
785 root->info.unused_flags);
786 goto fail;
787 }
788
789 indirect = root->info.indirect_levels;
790 if (indirect >= ext4_dir_htree_level(dir->i_sb)) {
791 ext4_warning(dir->i_sb,
792 "Directory (ino: %lu) htree depth %#06x exceed"
793 "supported value", dir->i_ino,
794 ext4_dir_htree_level(dir->i_sb));
795 if (ext4_dir_htree_level(dir->i_sb) < EXT4_HTREE_LEVEL) {
796 ext4_warning(dir->i_sb, "Enable large directory "
797 "feature to access it");
798 }
799 goto fail;
800 }
801
802 entries = (struct dx_entry *)(((char *)&root->info) +
803 root->info.info_length);
804
805 if (dx_get_limit(entries) != dx_root_limit(dir,
806 root->info.info_length)) {
807 ext4_warning_inode(dir, "dx entry: limit %u != root limit %u",
808 dx_get_limit(entries),
809 dx_root_limit(dir, root->info.info_length));
810 goto fail;
811 }
812
813 dxtrace(printk("Look up %x", hash));
814 while (1) {
815 count = dx_get_count(entries);
816 if (!count || count > dx_get_limit(entries)) {
817 ext4_warning_inode(dir,
818 "dx entry: count %u beyond limit %u",
819 count, dx_get_limit(entries));
820 goto fail;
821 }
822
823 p = entries + 1;
824 q = entries + count - 1;
825 while (p <= q) {
826 m = p + (q - p) / 2;
827 dxtrace(printk(KERN_CONT "."));
828 if (dx_get_hash(m) > hash)
829 q = m - 1;
830 else
831 p = m + 1;
832 }
833
834 if (0) { // linear search cross check
835 unsigned n = count - 1;
836 at = entries;
837 while (n--)
838 {
839 dxtrace(printk(KERN_CONT ","));
840 if (dx_get_hash(++at) > hash)
841 {
842 at--;
843 break;
844 }
845 }
846 assert (at == p - 1);
847 }
848
849 at = p - 1;
850 dxtrace(printk(KERN_CONT " %x->%u\n",
851 at == entries ? 0 : dx_get_hash(at),
852 dx_get_block(at)));
853 frame->entries = entries;
854 frame->at = at;
855 if (!indirect--)
856 return frame;
857 frame++;
858 frame->bh = ext4_read_dirblock(dir, dx_get_block(at), INDEX);
859 if (IS_ERR(frame->bh)) {
860 ret_err = (struct dx_frame *) frame->bh;
861 frame->bh = NULL;
862 goto fail;
863 }
864 entries = ((struct dx_node *) frame->bh->b_data)->entries;
865
866 if (dx_get_limit(entries) != dx_node_limit(dir)) {
867 ext4_warning_inode(dir,
868 "dx entry: limit %u != node limit %u",
869 dx_get_limit(entries), dx_node_limit(dir));
870 goto fail;
871 }
872 }
873fail:
874 while (frame >= frame_in) {
875 brelse(frame->bh);
876 frame--;
877 }
878
879 if (ret_err == ERR_PTR(ERR_BAD_DX_DIR))
880 ext4_warning_inode(dir,
881 "Corrupt directory, running e2fsck is recommended");
882 return ret_err;
883}
884
885static void dx_release(struct dx_frame *frames)
886{
887 struct dx_root_info *info;
888 int i;
889 unsigned int indirect_levels;
890
891 if (frames[0].bh == NULL)
892 return;
893
894 info = &((struct dx_root *)frames[0].bh->b_data)->info;
895 /* save local copy, "info" may be freed after brelse() */
896 indirect_levels = info->indirect_levels;
897 for (i = 0; i <= indirect_levels; i++) {
898 if (frames[i].bh == NULL)
899 break;
900 brelse(frames[i].bh);
901 frames[i].bh = NULL;
902 }
903}
904
905/*
906 * This function increments the frame pointer to search the next leaf
907 * block, and reads in the necessary intervening nodes if the search
908 * should be necessary. Whether or not the search is necessary is
909 * controlled by the hash parameter. If the hash value is even, then
910 * the search is only continued if the next block starts with that
911 * hash value. This is used if we are searching for a specific file.
912 *
913 * If the hash value is HASH_NB_ALWAYS, then always go to the next block.
914 *
915 * This function returns 1 if the caller should continue to search,
916 * or 0 if it should not. If there is an error reading one of the
917 * index blocks, it will a negative error code.
918 *
919 * If start_hash is non-null, it will be filled in with the starting
920 * hash of the next page.
921 */
922static int ext4_htree_next_block(struct inode *dir, __u32 hash,
923 struct dx_frame *frame,
924 struct dx_frame *frames,
925 __u32 *start_hash)
926{
927 struct dx_frame *p;
928 struct buffer_head *bh;
929 int num_frames = 0;
930 __u32 bhash;
931
932 p = frame;
933 /*
934 * Find the next leaf page by incrementing the frame pointer.
935 * If we run out of entries in the interior node, loop around and
936 * increment pointer in the parent node. When we break out of
937 * this loop, num_frames indicates the number of interior
938 * nodes need to be read.
939 */
940 while (1) {
941 if (++(p->at) < p->entries + dx_get_count(p->entries))
942 break;
943 if (p == frames)
944 return 0;
945 num_frames++;
946 p--;
947 }
948
949 /*
950 * If the hash is 1, then continue only if the next page has a
951 * continuation hash of any value. This is used for readdir
952 * handling. Otherwise, check to see if the hash matches the
953 * desired contiuation hash. If it doesn't, return since
954 * there's no point to read in the successive index pages.
955 */
956 bhash = dx_get_hash(p->at);
957 if (start_hash)
958 *start_hash = bhash;
959 if ((hash & 1) == 0) {
960 if ((bhash & ~1) != hash)
961 return 0;
962 }
963 /*
964 * If the hash is HASH_NB_ALWAYS, we always go to the next
965 * block so no check is necessary
966 */
967 while (num_frames--) {
968 bh = ext4_read_dirblock(dir, dx_get_block(p->at), INDEX);
969 if (IS_ERR(bh))
970 return PTR_ERR(bh);
971 p++;
972 brelse(p->bh);
973 p->bh = bh;
974 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
975 }
976 return 1;
977}
978
979
980/*
981 * This function fills a red-black tree with information from a
982 * directory block. It returns the number directory entries loaded
983 * into the tree. If there is an error it is returned in err.
984 */
985static int htree_dirblock_to_tree(struct file *dir_file,
986 struct inode *dir, ext4_lblk_t block,
987 struct dx_hash_info *hinfo,
988 __u32 start_hash, __u32 start_minor_hash)
989{
990 struct buffer_head *bh;
991 struct ext4_dir_entry_2 *de, *top;
992 int err = 0, count = 0;
993 struct fscrypt_str fname_crypto_str = FSTR_INIT(NULL, 0), tmp_str;
994
995 dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
996 (unsigned long)block));
997 bh = ext4_read_dirblock(dir, block, DIRENT_HTREE);
998 if (IS_ERR(bh))
999 return PTR_ERR(bh);
1000
1001 de = (struct ext4_dir_entry_2 *) bh->b_data;
1002 top = (struct ext4_dir_entry_2 *) ((char *) de +
1003 dir->i_sb->s_blocksize -
1004 EXT4_DIR_REC_LEN(0));
1005#ifdef CONFIG_FS_ENCRYPTION
1006 /* Check if the directory is encrypted */
1007 if (IS_ENCRYPTED(dir)) {
1008 err = fscrypt_get_encryption_info(dir);
1009 if (err < 0) {
1010 brelse(bh);
1011 return err;
1012 }
1013 err = fscrypt_fname_alloc_buffer(dir, EXT4_NAME_LEN,
1014 &fname_crypto_str);
1015 if (err < 0) {
1016 brelse(bh);
1017 return err;
1018 }
1019 }
1020#endif
1021 for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) {
1022 if (ext4_check_dir_entry(dir, NULL, de, bh,
1023 bh->b_data, bh->b_size,
1024 (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
1025 + ((char *)de - bh->b_data))) {
1026 /* silently ignore the rest of the block */
1027 break;
1028 }
1029 ext4fs_dirhash(dir, de->name, de->name_len, hinfo);
1030 if ((hinfo->hash < start_hash) ||
1031 ((hinfo->hash == start_hash) &&
1032 (hinfo->minor_hash < start_minor_hash)))
1033 continue;
1034 if (de->inode == 0)
1035 continue;
1036 if (!IS_ENCRYPTED(dir)) {
1037 tmp_str.name = de->name;
1038 tmp_str.len = de->name_len;
1039 err = ext4_htree_store_dirent(dir_file,
1040 hinfo->hash, hinfo->minor_hash, de,
1041 &tmp_str);
1042 } else {
1043 int save_len = fname_crypto_str.len;
1044 struct fscrypt_str de_name = FSTR_INIT(de->name,
1045 de->name_len);
1046
1047 /* Directory is encrypted */
1048 err = fscrypt_fname_disk_to_usr(dir, hinfo->hash,
1049 hinfo->minor_hash, &de_name,
1050 &fname_crypto_str);
1051 if (err) {
1052 count = err;
1053 goto errout;
1054 }
1055 err = ext4_htree_store_dirent(dir_file,
1056 hinfo->hash, hinfo->minor_hash, de,
1057 &fname_crypto_str);
1058 fname_crypto_str.len = save_len;
1059 }
1060 if (err != 0) {
1061 count = err;
1062 goto errout;
1063 }
1064 count++;
1065 }
1066errout:
1067 brelse(bh);
1068#ifdef CONFIG_FS_ENCRYPTION
1069 fscrypt_fname_free_buffer(&fname_crypto_str);
1070#endif
1071 return count;
1072}
1073
1074
1075/*
1076 * This function fills a red-black tree with information from a
1077 * directory. We start scanning the directory in hash order, starting
1078 * at start_hash and start_minor_hash.
1079 *
1080 * This function returns the number of entries inserted into the tree,
1081 * or a negative error code.
1082 */
1083int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
1084 __u32 start_minor_hash, __u32 *next_hash)
1085{
1086 struct dx_hash_info hinfo;
1087 struct ext4_dir_entry_2 *de;
1088 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
1089 struct inode *dir;
1090 ext4_lblk_t block;
1091 int count = 0;
1092 int ret, err;
1093 __u32 hashval;
1094 struct fscrypt_str tmp_str;
1095
1096 dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
1097 start_hash, start_minor_hash));
1098 dir = file_inode(dir_file);
1099 if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) {
1100 hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
1101 if (hinfo.hash_version <= DX_HASH_TEA)
1102 hinfo.hash_version +=
1103 EXT4_SB(dir->i_sb)->s_hash_unsigned;
1104 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
1105 if (ext4_has_inline_data(dir)) {
1106 int has_inline_data = 1;
1107 count = ext4_inlinedir_to_tree(dir_file, dir, 0,
1108 &hinfo, start_hash,
1109 start_minor_hash,
1110 &has_inline_data);
1111 if (has_inline_data) {
1112 *next_hash = ~0;
1113 return count;
1114 }
1115 }
1116 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
1117 start_hash, start_minor_hash);
1118 *next_hash = ~0;
1119 return count;
1120 }
1121 hinfo.hash = start_hash;
1122 hinfo.minor_hash = 0;
1123 frame = dx_probe(NULL, dir, &hinfo, frames);
1124 if (IS_ERR(frame))
1125 return PTR_ERR(frame);
1126
1127 /* Add '.' and '..' from the htree header */
1128 if (!start_hash && !start_minor_hash) {
1129 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
1130 tmp_str.name = de->name;
1131 tmp_str.len = de->name_len;
1132 err = ext4_htree_store_dirent(dir_file, 0, 0,
1133 de, &tmp_str);
1134 if (err != 0)
1135 goto errout;
1136 count++;
1137 }
1138 if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
1139 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
1140 de = ext4_next_entry(de, dir->i_sb->s_blocksize);
1141 tmp_str.name = de->name;
1142 tmp_str.len = de->name_len;
1143 err = ext4_htree_store_dirent(dir_file, 2, 0,
1144 de, &tmp_str);
1145 if (err != 0)
1146 goto errout;
1147 count++;
1148 }
1149
1150 while (1) {
1151 if (fatal_signal_pending(current)) {
1152 err = -ERESTARTSYS;
1153 goto errout;
1154 }
1155 cond_resched();
1156 block = dx_get_block(frame->at);
1157 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
1158 start_hash, start_minor_hash);
1159 if (ret < 0) {
1160 err = ret;
1161 goto errout;
1162 }
1163 count += ret;
1164 hashval = ~0;
1165 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
1166 frame, frames, &hashval);
1167 *next_hash = hashval;
1168 if (ret < 0) {
1169 err = ret;
1170 goto errout;
1171 }
1172 /*
1173 * Stop if: (a) there are no more entries, or
1174 * (b) we have inserted at least one entry and the
1175 * next hash value is not a continuation
1176 */
1177 if ((ret == 0) ||
1178 (count && ((hashval & 1) == 0)))
1179 break;
1180 }
1181 dx_release(frames);
1182 dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, "
1183 "next hash: %x\n", count, *next_hash));
1184 return count;
1185errout:
1186 dx_release(frames);
1187 return (err);
1188}
1189
1190static inline int search_dirblock(struct buffer_head *bh,
1191 struct inode *dir,
1192 struct ext4_filename *fname,
1193 unsigned int offset,
1194 struct ext4_dir_entry_2 **res_dir)
1195{
1196 return ext4_search_dir(bh, bh->b_data, dir->i_sb->s_blocksize, dir,
1197 fname, offset, res_dir);
1198}
1199
1200/*
1201 * Directory block splitting, compacting
1202 */
1203
1204/*
1205 * Create map of hash values, offsets, and sizes, stored at end of block.
1206 * Returns number of entries mapped.
1207 */
1208static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de,
1209 unsigned blocksize, struct dx_hash_info *hinfo,
1210 struct dx_map_entry *map_tail)
1211{
1212 int count = 0;
1213 char *base = (char *) de;
1214 struct dx_hash_info h = *hinfo;
1215
1216 while ((char *) de < base + blocksize) {
1217 if (de->name_len && de->inode) {
1218 ext4fs_dirhash(dir, de->name, de->name_len, &h);
1219 map_tail--;
1220 map_tail->hash = h.hash;
1221 map_tail->offs = ((char *) de - base)>>2;
1222 map_tail->size = le16_to_cpu(de->rec_len);
1223 count++;
1224 cond_resched();
1225 }
1226 /* XXX: do we need to check rec_len == 0 case? -Chris */
1227 de = ext4_next_entry(de, blocksize);
1228 }
1229 return count;
1230}
1231
1232/* Sort map by hash value */
1233static 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
1259static 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#ifdef CONFIG_UNICODE
1274/*
1275 * Test whether a case-insensitive directory entry matches the filename
1276 * being searched for. If quick is set, assume the name being looked up
1277 * is already in the casefolded form.
1278 *
1279 * Returns: 0 if the directory entry matches, more than 0 if it
1280 * doesn't match or less than zero on error.
1281 */
1282int ext4_ci_compare(const struct inode *parent, const struct qstr *name,
1283 const struct qstr *entry, bool quick)
1284{
1285 const struct ext4_sb_info *sbi = EXT4_SB(parent->i_sb);
1286 const struct unicode_map *um = sbi->s_encoding;
1287 int ret;
1288
1289 if (quick)
1290 ret = utf8_strncasecmp_folded(um, name, entry);
1291 else
1292 ret = utf8_strncasecmp(um, name, entry);
1293
1294 if (ret < 0) {
1295 /* Handle invalid character sequence as either an error
1296 * or as an opaque byte sequence.
1297 */
1298 if (ext4_has_strict_mode(sbi))
1299 return -EINVAL;
1300
1301 if (name->len != entry->len)
1302 return 1;
1303
1304 return !!memcmp(name->name, entry->name, name->len);
1305 }
1306
1307 return ret;
1308}
1309
1310void ext4_fname_setup_ci_filename(struct inode *dir, const struct qstr *iname,
1311 struct fscrypt_str *cf_name)
1312{
1313 int len;
1314
1315 if (!IS_CASEFOLDED(dir) || !EXT4_SB(dir->i_sb)->s_encoding) {
1316 cf_name->name = NULL;
1317 return;
1318 }
1319
1320 cf_name->name = kmalloc(EXT4_NAME_LEN, GFP_NOFS);
1321 if (!cf_name->name)
1322 return;
1323
1324 len = utf8_casefold(EXT4_SB(dir->i_sb)->s_encoding,
1325 iname, cf_name->name,
1326 EXT4_NAME_LEN);
1327 if (len <= 0) {
1328 kfree(cf_name->name);
1329 cf_name->name = NULL;
1330 return;
1331 }
1332 cf_name->len = (unsigned) len;
1333
1334}
1335#endif
1336
1337/*
1338 * Test whether a directory entry matches the filename being searched for.
1339 *
1340 * Return: %true if the directory entry matches, otherwise %false.
1341 */
1342static inline bool ext4_match(const struct inode *parent,
1343 const struct ext4_filename *fname,
1344 const struct ext4_dir_entry_2 *de)
1345{
1346 struct fscrypt_name f;
1347#ifdef CONFIG_UNICODE
1348 const struct qstr entry = {.name = de->name, .len = de->name_len};
1349#endif
1350
1351 if (!de->inode)
1352 return false;
1353
1354 f.usr_fname = fname->usr_fname;
1355 f.disk_name = fname->disk_name;
1356#ifdef CONFIG_FS_ENCRYPTION
1357 f.crypto_buf = fname->crypto_buf;
1358#endif
1359
1360#ifdef CONFIG_UNICODE
1361 if (EXT4_SB(parent->i_sb)->s_encoding && IS_CASEFOLDED(parent)) {
1362 if (fname->cf_name.name) {
1363 struct qstr cf = {.name = fname->cf_name.name,
1364 .len = fname->cf_name.len};
1365 return !ext4_ci_compare(parent, &cf, &entry, true);
1366 }
1367 return !ext4_ci_compare(parent, fname->usr_fname, &entry,
1368 false);
1369 }
1370#endif
1371
1372 return fscrypt_match_name(&f, de->name, de->name_len);
1373}
1374
1375/*
1376 * Returns 0 if not found, -1 on failure, and 1 on success
1377 */
1378int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size,
1379 struct inode *dir, struct ext4_filename *fname,
1380 unsigned int offset, struct ext4_dir_entry_2 **res_dir)
1381{
1382 struct ext4_dir_entry_2 * de;
1383 char * dlimit;
1384 int de_len;
1385
1386 de = (struct ext4_dir_entry_2 *)search_buf;
1387 dlimit = search_buf + buf_size;
1388 while ((char *) de < dlimit) {
1389 /* this code is executed quadratically often */
1390 /* do minimal checking `by hand' */
1391 if ((char *) de + de->name_len <= dlimit &&
1392 ext4_match(dir, fname, de)) {
1393 /* found a match - just to be sure, do
1394 * a full check */
1395 if (ext4_check_dir_entry(dir, NULL, de, bh, bh->b_data,
1396 bh->b_size, offset))
1397 return -1;
1398 *res_dir = de;
1399 return 1;
1400 }
1401 /* prevent looping on a bad block */
1402 de_len = ext4_rec_len_from_disk(de->rec_len,
1403 dir->i_sb->s_blocksize);
1404 if (de_len <= 0)
1405 return -1;
1406 offset += de_len;
1407 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
1408 }
1409 return 0;
1410}
1411
1412static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block,
1413 struct ext4_dir_entry *de)
1414{
1415 struct super_block *sb = dir->i_sb;
1416
1417 if (!is_dx(dir))
1418 return 0;
1419 if (block == 0)
1420 return 1;
1421 if (de->inode == 0 &&
1422 ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) ==
1423 sb->s_blocksize)
1424 return 1;
1425 return 0;
1426}
1427
1428/*
1429 * __ext4_find_entry()
1430 *
1431 * finds an entry in the specified directory with the wanted name. It
1432 * returns the cache buffer in which the entry was found, and the entry
1433 * itself (as a parameter - res_dir). It does NOT read the inode of the
1434 * entry - you'll have to do that yourself if you want to.
1435 *
1436 * The returned buffer_head has ->b_count elevated. The caller is expected
1437 * to brelse() it when appropriate.
1438 */
1439static struct buffer_head *__ext4_find_entry(struct inode *dir,
1440 struct ext4_filename *fname,
1441 struct ext4_dir_entry_2 **res_dir,
1442 int *inlined)
1443{
1444 struct super_block *sb;
1445 struct buffer_head *bh_use[NAMEI_RA_SIZE];
1446 struct buffer_head *bh, *ret = NULL;
1447 ext4_lblk_t start, block;
1448 const u8 *name = fname->usr_fname->name;
1449 size_t ra_max = 0; /* Number of bh's in the readahead
1450 buffer, bh_use[] */
1451 size_t ra_ptr = 0; /* Current index into readahead
1452 buffer */
1453 ext4_lblk_t nblocks;
1454 int i, namelen, retval;
1455
1456 *res_dir = NULL;
1457 sb = dir->i_sb;
1458 namelen = fname->usr_fname->len;
1459 if (namelen > EXT4_NAME_LEN)
1460 return NULL;
1461
1462 if (ext4_has_inline_data(dir)) {
1463 int has_inline_data = 1;
1464 ret = ext4_find_inline_entry(dir, fname, res_dir,
1465 &has_inline_data);
1466 if (has_inline_data) {
1467 if (inlined)
1468 *inlined = 1;
1469 goto cleanup_and_exit;
1470 }
1471 }
1472
1473 if ((namelen <= 2) && (name[0] == '.') &&
1474 (name[1] == '.' || name[1] == '\0')) {
1475 /*
1476 * "." or ".." will only be in the first block
1477 * NFS may look up ".."; "." should be handled by the VFS
1478 */
1479 block = start = 0;
1480 nblocks = 1;
1481 goto restart;
1482 }
1483 if (is_dx(dir)) {
1484 ret = ext4_dx_find_entry(dir, fname, res_dir);
1485 /*
1486 * On success, or if the error was file not found,
1487 * return. Otherwise, fall back to doing a search the
1488 * old fashioned way.
1489 */
1490 if (!IS_ERR(ret) || PTR_ERR(ret) != ERR_BAD_DX_DIR)
1491 goto cleanup_and_exit;
1492 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
1493 "falling back\n"));
1494 ret = NULL;
1495 }
1496 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1497 if (!nblocks) {
1498 ret = NULL;
1499 goto cleanup_and_exit;
1500 }
1501 start = EXT4_I(dir)->i_dir_start_lookup;
1502 if (start >= nblocks)
1503 start = 0;
1504 block = start;
1505restart:
1506 do {
1507 /*
1508 * We deal with the read-ahead logic here.
1509 */
1510 if (ra_ptr >= ra_max) {
1511 /* Refill the readahead buffer */
1512 ra_ptr = 0;
1513 if (block < start)
1514 ra_max = start - block;
1515 else
1516 ra_max = nblocks - block;
1517 ra_max = min(ra_max, ARRAY_SIZE(bh_use));
1518 retval = ext4_bread_batch(dir, block, ra_max,
1519 false /* wait */, bh_use);
1520 if (retval) {
1521 ret = ERR_PTR(retval);
1522 ra_max = 0;
1523 goto cleanup_and_exit;
1524 }
1525 }
1526 if ((bh = bh_use[ra_ptr++]) == NULL)
1527 goto next;
1528 wait_on_buffer(bh);
1529 if (!buffer_uptodate(bh)) {
1530 EXT4_ERROR_INODE(dir, "reading directory lblock %lu",
1531 (unsigned long) block);
1532 brelse(bh);
1533 ret = ERR_PTR(-EIO);
1534 goto cleanup_and_exit;
1535 }
1536 if (!buffer_verified(bh) &&
1537 !is_dx_internal_node(dir, block,
1538 (struct ext4_dir_entry *)bh->b_data) &&
1539 !ext4_dirblock_csum_verify(dir, bh)) {
1540 EXT4_ERROR_INODE(dir, "checksumming directory "
1541 "block %lu", (unsigned long)block);
1542 brelse(bh);
1543 ret = ERR_PTR(-EFSBADCRC);
1544 goto cleanup_and_exit;
1545 }
1546 set_buffer_verified(bh);
1547 i = search_dirblock(bh, dir, fname,
1548 block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
1549 if (i == 1) {
1550 EXT4_I(dir)->i_dir_start_lookup = block;
1551 ret = bh;
1552 goto cleanup_and_exit;
1553 } else {
1554 brelse(bh);
1555 if (i < 0)
1556 goto cleanup_and_exit;
1557 }
1558 next:
1559 if (++block >= nblocks)
1560 block = 0;
1561 } while (block != start);
1562
1563 /*
1564 * If the directory has grown while we were searching, then
1565 * search the last part of the directory before giving up.
1566 */
1567 block = nblocks;
1568 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1569 if (block < nblocks) {
1570 start = 0;
1571 goto restart;
1572 }
1573
1574cleanup_and_exit:
1575 /* Clean up the read-ahead blocks */
1576 for (; ra_ptr < ra_max; ra_ptr++)
1577 brelse(bh_use[ra_ptr]);
1578 return ret;
1579}
1580
1581static struct buffer_head *ext4_find_entry(struct inode *dir,
1582 const struct qstr *d_name,
1583 struct ext4_dir_entry_2 **res_dir,
1584 int *inlined)
1585{
1586 int err;
1587 struct ext4_filename fname;
1588 struct buffer_head *bh;
1589
1590 err = ext4_fname_setup_filename(dir, d_name, 1, &fname);
1591 if (err == -ENOENT)
1592 return NULL;
1593 if (err)
1594 return ERR_PTR(err);
1595
1596 bh = __ext4_find_entry(dir, &fname, res_dir, inlined);
1597
1598 ext4_fname_free_filename(&fname);
1599 return bh;
1600}
1601
1602static struct buffer_head *ext4_lookup_entry(struct inode *dir,
1603 struct dentry *dentry,
1604 struct ext4_dir_entry_2 **res_dir)
1605{
1606 int err;
1607 struct ext4_filename fname;
1608 struct buffer_head *bh;
1609
1610 err = ext4_fname_prepare_lookup(dir, dentry, &fname);
1611 if (err == -ENOENT)
1612 return NULL;
1613 if (err)
1614 return ERR_PTR(err);
1615
1616 bh = __ext4_find_entry(dir, &fname, res_dir, NULL);
1617
1618 ext4_fname_free_filename(&fname);
1619 return bh;
1620}
1621
1622static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
1623 struct ext4_filename *fname,
1624 struct ext4_dir_entry_2 **res_dir)
1625{
1626 struct super_block * sb = dir->i_sb;
1627 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
1628 struct buffer_head *bh;
1629 ext4_lblk_t block;
1630 int retval;
1631
1632#ifdef CONFIG_FS_ENCRYPTION
1633 *res_dir = NULL;
1634#endif
1635 frame = dx_probe(fname, dir, NULL, frames);
1636 if (IS_ERR(frame))
1637 return (struct buffer_head *) frame;
1638 do {
1639 block = dx_get_block(frame->at);
1640 bh = ext4_read_dirblock(dir, block, DIRENT_HTREE);
1641 if (IS_ERR(bh))
1642 goto errout;
1643
1644 retval = search_dirblock(bh, dir, fname,
1645 block << EXT4_BLOCK_SIZE_BITS(sb),
1646 res_dir);
1647 if (retval == 1)
1648 goto success;
1649 brelse(bh);
1650 if (retval == -1) {
1651 bh = ERR_PTR(ERR_BAD_DX_DIR);
1652 goto errout;
1653 }
1654
1655 /* Check to see if we should continue to search */
1656 retval = ext4_htree_next_block(dir, fname->hinfo.hash, frame,
1657 frames, NULL);
1658 if (retval < 0) {
1659 ext4_warning_inode(dir,
1660 "error %d reading directory index block",
1661 retval);
1662 bh = ERR_PTR(retval);
1663 goto errout;
1664 }
1665 } while (retval == 1);
1666
1667 bh = NULL;
1668errout:
1669 dxtrace(printk(KERN_DEBUG "%s not found\n", fname->usr_fname->name));
1670success:
1671 dx_release(frames);
1672 return bh;
1673}
1674
1675static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
1676{
1677 struct inode *inode;
1678 struct ext4_dir_entry_2 *de;
1679 struct buffer_head *bh;
1680
1681 if (dentry->d_name.len > EXT4_NAME_LEN)
1682 return ERR_PTR(-ENAMETOOLONG);
1683
1684 bh = ext4_lookup_entry(dir, dentry, &de);
1685 if (IS_ERR(bh))
1686 return ERR_CAST(bh);
1687 inode = NULL;
1688 if (bh) {
1689 __u32 ino = le32_to_cpu(de->inode);
1690 brelse(bh);
1691 if (!ext4_valid_inum(dir->i_sb, ino)) {
1692 EXT4_ERROR_INODE(dir, "bad inode number: %u", ino);
1693 return ERR_PTR(-EFSCORRUPTED);
1694 }
1695 if (unlikely(ino == dir->i_ino)) {
1696 EXT4_ERROR_INODE(dir, "'%pd' linked to parent dir",
1697 dentry);
1698 return ERR_PTR(-EFSCORRUPTED);
1699 }
1700 inode = ext4_iget(dir->i_sb, ino, EXT4_IGET_NORMAL);
1701 if (inode == ERR_PTR(-ESTALE)) {
1702 EXT4_ERROR_INODE(dir,
1703 "deleted inode referenced: %u",
1704 ino);
1705 return ERR_PTR(-EFSCORRUPTED);
1706 }
1707 if (!IS_ERR(inode) && IS_ENCRYPTED(dir) &&
1708 (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) &&
1709 !fscrypt_has_permitted_context(dir, inode)) {
1710 ext4_warning(inode->i_sb,
1711 "Inconsistent encryption contexts: %lu/%lu",
1712 dir->i_ino, inode->i_ino);
1713 iput(inode);
1714 return ERR_PTR(-EPERM);
1715 }
1716 }
1717
1718#ifdef CONFIG_UNICODE
1719 if (!inode && IS_CASEFOLDED(dir)) {
1720 /* Eventually we want to call d_add_ci(dentry, NULL)
1721 * for negative dentries in the encoding case as
1722 * well. For now, prevent the negative dentry
1723 * from being cached.
1724 */
1725 return NULL;
1726 }
1727#endif
1728 return d_splice_alias(inode, dentry);
1729}
1730
1731
1732struct dentry *ext4_get_parent(struct dentry *child)
1733{
1734 __u32 ino;
1735 static const struct qstr dotdot = QSTR_INIT("..", 2);
1736 struct ext4_dir_entry_2 * de;
1737 struct buffer_head *bh;
1738
1739 bh = ext4_find_entry(d_inode(child), &dotdot, &de, NULL);
1740 if (IS_ERR(bh))
1741 return ERR_CAST(bh);
1742 if (!bh)
1743 return ERR_PTR(-ENOENT);
1744 ino = le32_to_cpu(de->inode);
1745 brelse(bh);
1746
1747 if (!ext4_valid_inum(child->d_sb, ino)) {
1748 EXT4_ERROR_INODE(d_inode(child),
1749 "bad parent inode number: %u", ino);
1750 return ERR_PTR(-EFSCORRUPTED);
1751 }
1752
1753 return d_obtain_alias(ext4_iget(child->d_sb, ino, EXT4_IGET_NORMAL));
1754}
1755
1756/*
1757 * Move count entries from end of map between two memory locations.
1758 * Returns pointer to last entry moved.
1759 */
1760static struct ext4_dir_entry_2 *
1761dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count,
1762 unsigned blocksize)
1763{
1764 unsigned rec_len = 0;
1765
1766 while (count--) {
1767 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
1768 (from + (map->offs<<2));
1769 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1770 memcpy (to, de, rec_len);
1771 ((struct ext4_dir_entry_2 *) to)->rec_len =
1772 ext4_rec_len_to_disk(rec_len, blocksize);
1773 de->inode = 0;
1774 map++;
1775 to += rec_len;
1776 }
1777 return (struct ext4_dir_entry_2 *) (to - rec_len);
1778}
1779
1780/*
1781 * Compact each dir entry in the range to the minimal rec_len.
1782 * Returns pointer to last entry in range.
1783 */
1784static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize)
1785{
1786 struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
1787 unsigned rec_len = 0;
1788
1789 prev = to = de;
1790 while ((char*)de < base + blocksize) {
1791 next = ext4_next_entry(de, blocksize);
1792 if (de->inode && de->name_len) {
1793 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1794 if (de > to)
1795 memmove(to, de, rec_len);
1796 to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
1797 prev = to;
1798 to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
1799 }
1800 de = next;
1801 }
1802 return prev;
1803}
1804
1805/*
1806 * Split a full leaf block to make room for a new dir entry.
1807 * Allocate a new block, and move entries so that they are approx. equally full.
1808 * Returns pointer to de in block into which the new entry will be inserted.
1809 */
1810static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
1811 struct buffer_head **bh,struct dx_frame *frame,
1812 struct dx_hash_info *hinfo)
1813{
1814 unsigned blocksize = dir->i_sb->s_blocksize;
1815 unsigned count, continued;
1816 struct buffer_head *bh2;
1817 ext4_lblk_t newblock;
1818 u32 hash2;
1819 struct dx_map_entry *map;
1820 char *data1 = (*bh)->b_data, *data2;
1821 unsigned split, move, size;
1822 struct ext4_dir_entry_2 *de = NULL, *de2;
1823 int csum_size = 0;
1824 int err = 0, i;
1825
1826 if (ext4_has_metadata_csum(dir->i_sb))
1827 csum_size = sizeof(struct ext4_dir_entry_tail);
1828
1829 bh2 = ext4_append(handle, dir, &newblock);
1830 if (IS_ERR(bh2)) {
1831 brelse(*bh);
1832 *bh = NULL;
1833 return (struct ext4_dir_entry_2 *) bh2;
1834 }
1835
1836 BUFFER_TRACE(*bh, "get_write_access");
1837 err = ext4_journal_get_write_access(handle, *bh);
1838 if (err)
1839 goto journal_error;
1840
1841 BUFFER_TRACE(frame->bh, "get_write_access");
1842 err = ext4_journal_get_write_access(handle, frame->bh);
1843 if (err)
1844 goto journal_error;
1845
1846 data2 = bh2->b_data;
1847
1848 /* create map in the end of data2 block */
1849 map = (struct dx_map_entry *) (data2 + blocksize);
1850 count = dx_make_map(dir, (struct ext4_dir_entry_2 *) data1,
1851 blocksize, hinfo, map);
1852 map -= count;
1853 dx_sort_map(map, count);
1854 /* Split the existing block in the middle, size-wise */
1855 size = 0;
1856 move = 0;
1857 for (i = count-1; i >= 0; i--) {
1858 /* is more than half of this entry in 2nd half of the block? */
1859 if (size + map[i].size/2 > blocksize/2)
1860 break;
1861 size += map[i].size;
1862 move++;
1863 }
1864 /* map index at which we will split */
1865 split = count - move;
1866 hash2 = map[split].hash;
1867 continued = hash2 == map[split - 1].hash;
1868 dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
1869 (unsigned long)dx_get_block(frame->at),
1870 hash2, split, count-split));
1871
1872 /* Fancy dance to stay within two buffers */
1873 de2 = dx_move_dirents(data1, data2, map + split, count - split,
1874 blocksize);
1875 de = dx_pack_dirents(data1, blocksize);
1876 de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
1877 (char *) de,
1878 blocksize);
1879 de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
1880 (char *) de2,
1881 blocksize);
1882 if (csum_size) {
1883 ext4_initialize_dirent_tail(*bh, blocksize);
1884 ext4_initialize_dirent_tail(bh2, blocksize);
1885 }
1886
1887 dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data1,
1888 blocksize, 1));
1889 dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data2,
1890 blocksize, 1));
1891
1892 /* Which block gets the new entry? */
1893 if (hinfo->hash >= hash2) {
1894 swap(*bh, bh2);
1895 de = de2;
1896 }
1897 dx_insert_block(frame, hash2 + continued, newblock);
1898 err = ext4_handle_dirty_dirblock(handle, dir, bh2);
1899 if (err)
1900 goto journal_error;
1901 err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
1902 if (err)
1903 goto journal_error;
1904 brelse(bh2);
1905 dxtrace(dx_show_index("frame", frame->entries));
1906 return de;
1907
1908journal_error:
1909 brelse(*bh);
1910 brelse(bh2);
1911 *bh = NULL;
1912 ext4_std_error(dir->i_sb, err);
1913 return ERR_PTR(err);
1914}
1915
1916int ext4_find_dest_de(struct inode *dir, struct inode *inode,
1917 struct buffer_head *bh,
1918 void *buf, int buf_size,
1919 struct ext4_filename *fname,
1920 struct ext4_dir_entry_2 **dest_de)
1921{
1922 struct ext4_dir_entry_2 *de;
1923 unsigned short reclen = EXT4_DIR_REC_LEN(fname_len(fname));
1924 int nlen, rlen;
1925 unsigned int offset = 0;
1926 char *top;
1927
1928 de = (struct ext4_dir_entry_2 *)buf;
1929 top = buf + buf_size - reclen;
1930 while ((char *) de <= top) {
1931 if (ext4_check_dir_entry(dir, NULL, de, bh,
1932 buf, buf_size, offset))
1933 return -EFSCORRUPTED;
1934 if (ext4_match(dir, fname, de))
1935 return -EEXIST;
1936 nlen = EXT4_DIR_REC_LEN(de->name_len);
1937 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
1938 if ((de->inode ? rlen - nlen : rlen) >= reclen)
1939 break;
1940 de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
1941 offset += rlen;
1942 }
1943 if ((char *) de > top)
1944 return -ENOSPC;
1945
1946 *dest_de = de;
1947 return 0;
1948}
1949
1950void ext4_insert_dentry(struct inode *inode,
1951 struct ext4_dir_entry_2 *de,
1952 int buf_size,
1953 struct ext4_filename *fname)
1954{
1955
1956 int nlen, rlen;
1957
1958 nlen = EXT4_DIR_REC_LEN(de->name_len);
1959 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
1960 if (de->inode) {
1961 struct ext4_dir_entry_2 *de1 =
1962 (struct ext4_dir_entry_2 *)((char *)de + nlen);
1963 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, buf_size);
1964 de->rec_len = ext4_rec_len_to_disk(nlen, buf_size);
1965 de = de1;
1966 }
1967 de->file_type = EXT4_FT_UNKNOWN;
1968 de->inode = cpu_to_le32(inode->i_ino);
1969 ext4_set_de_type(inode->i_sb, de, inode->i_mode);
1970 de->name_len = fname_len(fname);
1971 memcpy(de->name, fname_name(fname), fname_len(fname));
1972}
1973
1974/*
1975 * Add a new entry into a directory (leaf) block. If de is non-NULL,
1976 * it points to a directory entry which is guaranteed to be large
1977 * enough for new directory entry. If de is NULL, then
1978 * add_dirent_to_buf will attempt search the directory block for
1979 * space. It will return -ENOSPC if no space is available, and -EIO
1980 * and -EEXIST if directory entry already exists.
1981 */
1982static int add_dirent_to_buf(handle_t *handle, struct ext4_filename *fname,
1983 struct inode *dir,
1984 struct inode *inode, struct ext4_dir_entry_2 *de,
1985 struct buffer_head *bh)
1986{
1987 unsigned int blocksize = dir->i_sb->s_blocksize;
1988 int csum_size = 0;
1989 int err;
1990
1991 if (ext4_has_metadata_csum(inode->i_sb))
1992 csum_size = sizeof(struct ext4_dir_entry_tail);
1993
1994 if (!de) {
1995 err = ext4_find_dest_de(dir, inode, bh, bh->b_data,
1996 blocksize - csum_size, fname, &de);
1997 if (err)
1998 return err;
1999 }
2000 BUFFER_TRACE(bh, "get_write_access");
2001 err = ext4_journal_get_write_access(handle, bh);
2002 if (err) {
2003 ext4_std_error(dir->i_sb, err);
2004 return err;
2005 }
2006
2007 /* By now the buffer is marked for journaling */
2008 ext4_insert_dentry(inode, de, blocksize, fname);
2009
2010 /*
2011 * XXX shouldn't update any times until successful
2012 * completion of syscall, but too many callers depend
2013 * on this.
2014 *
2015 * XXX similarly, too many callers depend on
2016 * ext4_new_inode() setting the times, but error
2017 * recovery deletes the inode, so the worst that can
2018 * happen is that the times are slightly out of date
2019 * and/or different from the directory change time.
2020 */
2021 dir->i_mtime = dir->i_ctime = current_time(dir);
2022 ext4_update_dx_flag(dir);
2023 inode_inc_iversion(dir);
2024 ext4_mark_inode_dirty(handle, dir);
2025 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
2026 err = ext4_handle_dirty_dirblock(handle, dir, bh);
2027 if (err)
2028 ext4_std_error(dir->i_sb, err);
2029 return 0;
2030}
2031
2032/*
2033 * This converts a one block unindexed directory to a 3 block indexed
2034 * directory, and adds the dentry to the indexed directory.
2035 */
2036static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname,
2037 struct inode *dir,
2038 struct inode *inode, struct buffer_head *bh)
2039{
2040 struct buffer_head *bh2;
2041 struct dx_root *root;
2042 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
2043 struct dx_entry *entries;
2044 struct ext4_dir_entry_2 *de, *de2;
2045 char *data2, *top;
2046 unsigned len;
2047 int retval;
2048 unsigned blocksize;
2049 ext4_lblk_t block;
2050 struct fake_dirent *fde;
2051 int csum_size = 0;
2052
2053 if (ext4_has_metadata_csum(inode->i_sb))
2054 csum_size = sizeof(struct ext4_dir_entry_tail);
2055
2056 blocksize = dir->i_sb->s_blocksize;
2057 dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
2058 BUFFER_TRACE(bh, "get_write_access");
2059 retval = ext4_journal_get_write_access(handle, bh);
2060 if (retval) {
2061 ext4_std_error(dir->i_sb, retval);
2062 brelse(bh);
2063 return retval;
2064 }
2065 root = (struct dx_root *) bh->b_data;
2066
2067 /* The 0th block becomes the root, move the dirents out */
2068 fde = &root->dotdot;
2069 de = (struct ext4_dir_entry_2 *)((char *)fde +
2070 ext4_rec_len_from_disk(fde->rec_len, blocksize));
2071 if ((char *) de >= (((char *) root) + blocksize)) {
2072 EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
2073 brelse(bh);
2074 return -EFSCORRUPTED;
2075 }
2076 len = ((char *) root) + (blocksize - csum_size) - (char *) de;
2077
2078 /* Allocate new block for the 0th block's dirents */
2079 bh2 = ext4_append(handle, dir, &block);
2080 if (IS_ERR(bh2)) {
2081 brelse(bh);
2082 return PTR_ERR(bh2);
2083 }
2084 ext4_set_inode_flag(dir, EXT4_INODE_INDEX);
2085 data2 = bh2->b_data;
2086
2087 memcpy(data2, de, len);
2088 de = (struct ext4_dir_entry_2 *) data2;
2089 top = data2 + len;
2090 while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
2091 de = de2;
2092 de->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
2093 (char *) de, blocksize);
2094
2095 if (csum_size)
2096 ext4_initialize_dirent_tail(bh2, blocksize);
2097
2098 /* Initialize the root; the dot dirents already exist */
2099 de = (struct ext4_dir_entry_2 *) (&root->dotdot);
2100 de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
2101 blocksize);
2102 memset (&root->info, 0, sizeof(root->info));
2103 root->info.info_length = sizeof(root->info);
2104 root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
2105 entries = root->entries;
2106 dx_set_block(entries, 1);
2107 dx_set_count(entries, 1);
2108 dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
2109
2110 /* Initialize as for dx_probe */
2111 fname->hinfo.hash_version = root->info.hash_version;
2112 if (fname->hinfo.hash_version <= DX_HASH_TEA)
2113 fname->hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
2114 fname->hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
2115 ext4fs_dirhash(dir, fname_name(fname), fname_len(fname), &fname->hinfo);
2116
2117 memset(frames, 0, sizeof(frames));
2118 frame = frames;
2119 frame->entries = entries;
2120 frame->at = entries;
2121 frame->bh = bh;
2122
2123 retval = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
2124 if (retval)
2125 goto out_frames;
2126 retval = ext4_handle_dirty_dirblock(handle, dir, bh2);
2127 if (retval)
2128 goto out_frames;
2129
2130 de = do_split(handle,dir, &bh2, frame, &fname->hinfo);
2131 if (IS_ERR(de)) {
2132 retval = PTR_ERR(de);
2133 goto out_frames;
2134 }
2135
2136 retval = add_dirent_to_buf(handle, fname, dir, inode, de, bh2);
2137out_frames:
2138 /*
2139 * Even if the block split failed, we have to properly write
2140 * out all the changes we did so far. Otherwise we can end up
2141 * with corrupted filesystem.
2142 */
2143 if (retval)
2144 ext4_mark_inode_dirty(handle, dir);
2145 dx_release(frames);
2146 brelse(bh2);
2147 return retval;
2148}
2149
2150/*
2151 * ext4_add_entry()
2152 *
2153 * adds a file entry to the specified directory, using the same
2154 * semantics as ext4_find_entry(). It returns NULL if it failed.
2155 *
2156 * NOTE!! The inode part of 'de' is left at 0 - which means you
2157 * may not sleep between calling this and putting something into
2158 * the entry, as someone else might have used it while you slept.
2159 */
2160static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
2161 struct inode *inode)
2162{
2163 struct inode *dir = d_inode(dentry->d_parent);
2164 struct buffer_head *bh = NULL;
2165 struct ext4_dir_entry_2 *de;
2166 struct super_block *sb;
2167 struct ext4_sb_info *sbi;
2168 struct ext4_filename fname;
2169 int retval;
2170 int dx_fallback=0;
2171 unsigned blocksize;
2172 ext4_lblk_t block, blocks;
2173 int csum_size = 0;
2174
2175 if (ext4_has_metadata_csum(inode->i_sb))
2176 csum_size = sizeof(struct ext4_dir_entry_tail);
2177
2178 sb = dir->i_sb;
2179 sbi = EXT4_SB(sb);
2180 blocksize = sb->s_blocksize;
2181 if (!dentry->d_name.len)
2182 return -EINVAL;
2183
2184#ifdef CONFIG_UNICODE
2185 if (ext4_has_strict_mode(sbi) && IS_CASEFOLDED(dir) &&
2186 sbi->s_encoding && utf8_validate(sbi->s_encoding, &dentry->d_name))
2187 return -EINVAL;
2188#endif
2189
2190 retval = ext4_fname_setup_filename(dir, &dentry->d_name, 0, &fname);
2191 if (retval)
2192 return retval;
2193
2194 if (ext4_has_inline_data(dir)) {
2195 retval = ext4_try_add_inline_entry(handle, &fname, dir, inode);
2196 if (retval < 0)
2197 goto out;
2198 if (retval == 1) {
2199 retval = 0;
2200 goto out;
2201 }
2202 }
2203
2204 if (is_dx(dir)) {
2205 retval = ext4_dx_add_entry(handle, &fname, dir, inode);
2206 if (!retval || (retval != ERR_BAD_DX_DIR))
2207 goto out;
2208 ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
2209 dx_fallback++;
2210 ext4_mark_inode_dirty(handle, dir);
2211 }
2212 blocks = dir->i_size >> sb->s_blocksize_bits;
2213 for (block = 0; block < blocks; block++) {
2214 bh = ext4_read_dirblock(dir, block, DIRENT);
2215 if (bh == NULL) {
2216 bh = ext4_bread(handle, dir, block,
2217 EXT4_GET_BLOCKS_CREATE);
2218 goto add_to_new_block;
2219 }
2220 if (IS_ERR(bh)) {
2221 retval = PTR_ERR(bh);
2222 bh = NULL;
2223 goto out;
2224 }
2225 retval = add_dirent_to_buf(handle, &fname, dir, inode,
2226 NULL, bh);
2227 if (retval != -ENOSPC)
2228 goto out;
2229
2230 if (blocks == 1 && !dx_fallback &&
2231 ext4_has_feature_dir_index(sb)) {
2232 retval = make_indexed_dir(handle, &fname, dir,
2233 inode, bh);
2234 bh = NULL; /* make_indexed_dir releases bh */
2235 goto out;
2236 }
2237 brelse(bh);
2238 }
2239 bh = ext4_append(handle, dir, &block);
2240add_to_new_block:
2241 if (IS_ERR(bh)) {
2242 retval = PTR_ERR(bh);
2243 bh = NULL;
2244 goto out;
2245 }
2246 de = (struct ext4_dir_entry_2 *) bh->b_data;
2247 de->inode = 0;
2248 de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize);
2249
2250 if (csum_size)
2251 ext4_initialize_dirent_tail(bh, blocksize);
2252
2253 retval = add_dirent_to_buf(handle, &fname, dir, inode, de, bh);
2254out:
2255 ext4_fname_free_filename(&fname);
2256 brelse(bh);
2257 if (retval == 0)
2258 ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY);
2259 return retval;
2260}
2261
2262/*
2263 * Returns 0 for success, or a negative error value
2264 */
2265static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
2266 struct inode *dir, struct inode *inode)
2267{
2268 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
2269 struct dx_entry *entries, *at;
2270 struct buffer_head *bh;
2271 struct super_block *sb = dir->i_sb;
2272 struct ext4_dir_entry_2 *de;
2273 int restart;
2274 int err;
2275
2276again:
2277 restart = 0;
2278 frame = dx_probe(fname, dir, NULL, frames);
2279 if (IS_ERR(frame))
2280 return PTR_ERR(frame);
2281 entries = frame->entries;
2282 at = frame->at;
2283 bh = ext4_read_dirblock(dir, dx_get_block(frame->at), DIRENT_HTREE);
2284 if (IS_ERR(bh)) {
2285 err = PTR_ERR(bh);
2286 bh = NULL;
2287 goto cleanup;
2288 }
2289
2290 BUFFER_TRACE(bh, "get_write_access");
2291 err = ext4_journal_get_write_access(handle, bh);
2292 if (err)
2293 goto journal_error;
2294
2295 err = add_dirent_to_buf(handle, fname, dir, inode, NULL, bh);
2296 if (err != -ENOSPC)
2297 goto cleanup;
2298
2299 err = 0;
2300 /* Block full, should compress but for now just split */
2301 dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
2302 dx_get_count(entries), dx_get_limit(entries)));
2303 /* Need to split index? */
2304 if (dx_get_count(entries) == dx_get_limit(entries)) {
2305 ext4_lblk_t newblock;
2306 int levels = frame - frames + 1;
2307 unsigned int icount;
2308 int add_level = 1;
2309 struct dx_entry *entries2;
2310 struct dx_node *node2;
2311 struct buffer_head *bh2;
2312
2313 while (frame > frames) {
2314 if (dx_get_count((frame - 1)->entries) <
2315 dx_get_limit((frame - 1)->entries)) {
2316 add_level = 0;
2317 break;
2318 }
2319 frame--; /* split higher index block */
2320 at = frame->at;
2321 entries = frame->entries;
2322 restart = 1;
2323 }
2324 if (add_level && levels == ext4_dir_htree_level(sb)) {
2325 ext4_warning(sb, "Directory (ino: %lu) index full, "
2326 "reach max htree level :%d",
2327 dir->i_ino, levels);
2328 if (ext4_dir_htree_level(sb) < EXT4_HTREE_LEVEL) {
2329 ext4_warning(sb, "Large directory feature is "
2330 "not enabled on this "
2331 "filesystem");
2332 }
2333 err = -ENOSPC;
2334 goto cleanup;
2335 }
2336 icount = dx_get_count(entries);
2337 bh2 = ext4_append(handle, dir, &newblock);
2338 if (IS_ERR(bh2)) {
2339 err = PTR_ERR(bh2);
2340 goto cleanup;
2341 }
2342 node2 = (struct dx_node *)(bh2->b_data);
2343 entries2 = node2->entries;
2344 memset(&node2->fake, 0, sizeof(struct fake_dirent));
2345 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
2346 sb->s_blocksize);
2347 BUFFER_TRACE(frame->bh, "get_write_access");
2348 err = ext4_journal_get_write_access(handle, frame->bh);
2349 if (err)
2350 goto journal_error;
2351 if (!add_level) {
2352 unsigned icount1 = icount/2, icount2 = icount - icount1;
2353 unsigned hash2 = dx_get_hash(entries + icount1);
2354 dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
2355 icount1, icount2));
2356
2357 BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
2358 err = ext4_journal_get_write_access(handle,
2359 (frame - 1)->bh);
2360 if (err)
2361 goto journal_error;
2362
2363 memcpy((char *) entries2, (char *) (entries + icount1),
2364 icount2 * sizeof(struct dx_entry));
2365 dx_set_count(entries, icount1);
2366 dx_set_count(entries2, icount2);
2367 dx_set_limit(entries2, dx_node_limit(dir));
2368
2369 /* Which index block gets the new entry? */
2370 if (at - entries >= icount1) {
2371 frame->at = at = at - entries - icount1 + entries2;
2372 frame->entries = entries = entries2;
2373 swap(frame->bh, bh2);
2374 }
2375 dx_insert_block((frame - 1), hash2, newblock);
2376 dxtrace(dx_show_index("node", frame->entries));
2377 dxtrace(dx_show_index("node",
2378 ((struct dx_node *) bh2->b_data)->entries));
2379 err = ext4_handle_dirty_dx_node(handle, dir, bh2);
2380 if (err)
2381 goto journal_error;
2382 brelse (bh2);
2383 err = ext4_handle_dirty_dx_node(handle, dir,
2384 (frame - 1)->bh);
2385 if (err)
2386 goto journal_error;
2387 if (restart) {
2388 err = ext4_handle_dirty_dx_node(handle, dir,
2389 frame->bh);
2390 goto journal_error;
2391 }
2392 } else {
2393 struct dx_root *dxroot;
2394 memcpy((char *) entries2, (char *) entries,
2395 icount * sizeof(struct dx_entry));
2396 dx_set_limit(entries2, dx_node_limit(dir));
2397
2398 /* Set up root */
2399 dx_set_count(entries, 1);
2400 dx_set_block(entries + 0, newblock);
2401 dxroot = (struct dx_root *)frames[0].bh->b_data;
2402 dxroot->info.indirect_levels += 1;
2403 dxtrace(printk(KERN_DEBUG
2404 "Creating %d level index...\n",
2405 dxroot->info.indirect_levels));
2406 err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
2407 if (err)
2408 goto journal_error;
2409 err = ext4_handle_dirty_dx_node(handle, dir, bh2);
2410 brelse(bh2);
2411 restart = 1;
2412 goto journal_error;
2413 }
2414 }
2415 de = do_split(handle, dir, &bh, frame, &fname->hinfo);
2416 if (IS_ERR(de)) {
2417 err = PTR_ERR(de);
2418 goto cleanup;
2419 }
2420 err = add_dirent_to_buf(handle, fname, dir, inode, de, bh);
2421 goto cleanup;
2422
2423journal_error:
2424 ext4_std_error(dir->i_sb, err); /* this is a no-op if err == 0 */
2425cleanup:
2426 brelse(bh);
2427 dx_release(frames);
2428 /* @restart is true means htree-path has been changed, we need to
2429 * repeat dx_probe() to find out valid htree-path
2430 */
2431 if (restart && err == 0)
2432 goto again;
2433 return err;
2434}
2435
2436/*
2437 * ext4_generic_delete_entry deletes a directory entry by merging it
2438 * with the previous entry
2439 */
2440int ext4_generic_delete_entry(handle_t *handle,
2441 struct inode *dir,
2442 struct ext4_dir_entry_2 *de_del,
2443 struct buffer_head *bh,
2444 void *entry_buf,
2445 int buf_size,
2446 int csum_size)
2447{
2448 struct ext4_dir_entry_2 *de, *pde;
2449 unsigned int blocksize = dir->i_sb->s_blocksize;
2450 int i;
2451
2452 i = 0;
2453 pde = NULL;
2454 de = (struct ext4_dir_entry_2 *)entry_buf;
2455 while (i < buf_size - csum_size) {
2456 if (ext4_check_dir_entry(dir, NULL, de, bh,
2457 bh->b_data, bh->b_size, i))
2458 return -EFSCORRUPTED;
2459 if (de == de_del) {
2460 if (pde)
2461 pde->rec_len = ext4_rec_len_to_disk(
2462 ext4_rec_len_from_disk(pde->rec_len,
2463 blocksize) +
2464 ext4_rec_len_from_disk(de->rec_len,
2465 blocksize),
2466 blocksize);
2467 else
2468 de->inode = 0;
2469 inode_inc_iversion(dir);
2470 return 0;
2471 }
2472 i += ext4_rec_len_from_disk(de->rec_len, blocksize);
2473 pde = de;
2474 de = ext4_next_entry(de, blocksize);
2475 }
2476 return -ENOENT;
2477}
2478
2479static int ext4_delete_entry(handle_t *handle,
2480 struct inode *dir,
2481 struct ext4_dir_entry_2 *de_del,
2482 struct buffer_head *bh)
2483{
2484 int err, csum_size = 0;
2485
2486 if (ext4_has_inline_data(dir)) {
2487 int has_inline_data = 1;
2488 err = ext4_delete_inline_entry(handle, dir, de_del, bh,
2489 &has_inline_data);
2490 if (has_inline_data)
2491 return err;
2492 }
2493
2494 if (ext4_has_metadata_csum(dir->i_sb))
2495 csum_size = sizeof(struct ext4_dir_entry_tail);
2496
2497 BUFFER_TRACE(bh, "get_write_access");
2498 err = ext4_journal_get_write_access(handle, bh);
2499 if (unlikely(err))
2500 goto out;
2501
2502 err = ext4_generic_delete_entry(handle, dir, de_del,
2503 bh, bh->b_data,
2504 dir->i_sb->s_blocksize, csum_size);
2505 if (err)
2506 goto out;
2507
2508 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
2509 err = ext4_handle_dirty_dirblock(handle, dir, bh);
2510 if (unlikely(err))
2511 goto out;
2512
2513 return 0;
2514out:
2515 if (err != -ENOENT)
2516 ext4_std_error(dir->i_sb, err);
2517 return err;
2518}
2519
2520/*
2521 * Set directory link count to 1 if nlinks > EXT4_LINK_MAX, or if nlinks == 2
2522 * since this indicates that nlinks count was previously 1 to avoid overflowing
2523 * the 16-bit i_links_count field on disk. Directories with i_nlink == 1 mean
2524 * that subdirectory link counts are not being maintained accurately.
2525 *
2526 * The caller has already checked for i_nlink overflow in case the DIR_LINK
2527 * feature is not enabled and returned -EMLINK. The is_dx() check is a proxy
2528 * for checking S_ISDIR(inode) (since the INODE_INDEX feature will not be set
2529 * on regular files) and to avoid creating huge/slow non-HTREE directories.
2530 */
2531static void ext4_inc_count(handle_t *handle, struct inode *inode)
2532{
2533 inc_nlink(inode);
2534 if (is_dx(inode) &&
2535 (inode->i_nlink > EXT4_LINK_MAX || inode->i_nlink == 2))
2536 set_nlink(inode, 1);
2537}
2538
2539/*
2540 * If a directory had nlink == 1, then we should let it be 1. This indicates
2541 * directory has >EXT4_LINK_MAX subdirs.
2542 */
2543static void ext4_dec_count(handle_t *handle, struct inode *inode)
2544{
2545 if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
2546 drop_nlink(inode);
2547}
2548
2549
2550static int ext4_add_nondir(handle_t *handle,
2551 struct dentry *dentry, struct inode *inode)
2552{
2553 int err = ext4_add_entry(handle, dentry, inode);
2554 if (!err) {
2555 ext4_mark_inode_dirty(handle, inode);
2556 d_instantiate_new(dentry, inode);
2557 return 0;
2558 }
2559 drop_nlink(inode);
2560 unlock_new_inode(inode);
2561 iput(inode);
2562 return err;
2563}
2564
2565/*
2566 * By the time this is called, we already have created
2567 * the directory cache entry for the new file, but it
2568 * is so far negative - it has no inode.
2569 *
2570 * If the create succeeds, we fill in the inode information
2571 * with d_instantiate().
2572 */
2573static int ext4_create(struct inode *dir, struct dentry *dentry, umode_t mode,
2574 bool excl)
2575{
2576 handle_t *handle;
2577 struct inode *inode;
2578 int err, credits, retries = 0;
2579
2580 err = dquot_initialize(dir);
2581 if (err)
2582 return err;
2583
2584 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2585 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2586retry:
2587 inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
2588 NULL, EXT4_HT_DIR, credits);
2589 handle = ext4_journal_current_handle();
2590 err = PTR_ERR(inode);
2591 if (!IS_ERR(inode)) {
2592 inode->i_op = &ext4_file_inode_operations;
2593 inode->i_fop = &ext4_file_operations;
2594 ext4_set_aops(inode);
2595 err = ext4_add_nondir(handle, dentry, inode);
2596 if (!err && IS_DIRSYNC(dir))
2597 ext4_handle_sync(handle);
2598 }
2599 if (handle)
2600 ext4_journal_stop(handle);
2601 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2602 goto retry;
2603 return err;
2604}
2605
2606static int ext4_mknod(struct inode *dir, struct dentry *dentry,
2607 umode_t mode, dev_t rdev)
2608{
2609 handle_t *handle;
2610 struct inode *inode;
2611 int err, credits, retries = 0;
2612
2613 err = dquot_initialize(dir);
2614 if (err)
2615 return err;
2616
2617 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2618 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2619retry:
2620 inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
2621 NULL, EXT4_HT_DIR, credits);
2622 handle = ext4_journal_current_handle();
2623 err = PTR_ERR(inode);
2624 if (!IS_ERR(inode)) {
2625 init_special_inode(inode, inode->i_mode, rdev);
2626 inode->i_op = &ext4_special_inode_operations;
2627 err = ext4_add_nondir(handle, dentry, inode);
2628 if (!err && IS_DIRSYNC(dir))
2629 ext4_handle_sync(handle);
2630 }
2631 if (handle)
2632 ext4_journal_stop(handle);
2633 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2634 goto retry;
2635 return err;
2636}
2637
2638static int ext4_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
2639{
2640 handle_t *handle;
2641 struct inode *inode;
2642 int err, retries = 0;
2643
2644 err = dquot_initialize(dir);
2645 if (err)
2646 return err;
2647
2648retry:
2649 inode = ext4_new_inode_start_handle(dir, mode,
2650 NULL, 0, NULL,
2651 EXT4_HT_DIR,
2652 EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
2653 4 + EXT4_XATTR_TRANS_BLOCKS);
2654 handle = ext4_journal_current_handle();
2655 err = PTR_ERR(inode);
2656 if (!IS_ERR(inode)) {
2657 inode->i_op = &ext4_file_inode_operations;
2658 inode->i_fop = &ext4_file_operations;
2659 ext4_set_aops(inode);
2660 d_tmpfile(dentry, inode);
2661 err = ext4_orphan_add(handle, inode);
2662 if (err)
2663 goto err_unlock_inode;
2664 mark_inode_dirty(inode);
2665 unlock_new_inode(inode);
2666 }
2667 if (handle)
2668 ext4_journal_stop(handle);
2669 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2670 goto retry;
2671 return err;
2672err_unlock_inode:
2673 ext4_journal_stop(handle);
2674 unlock_new_inode(inode);
2675 return err;
2676}
2677
2678struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
2679 struct ext4_dir_entry_2 *de,
2680 int blocksize, int csum_size,
2681 unsigned int parent_ino, int dotdot_real_len)
2682{
2683 de->inode = cpu_to_le32(inode->i_ino);
2684 de->name_len = 1;
2685 de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
2686 blocksize);
2687 strcpy(de->name, ".");
2688 ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2689
2690 de = ext4_next_entry(de, blocksize);
2691 de->inode = cpu_to_le32(parent_ino);
2692 de->name_len = 2;
2693 if (!dotdot_real_len)
2694 de->rec_len = ext4_rec_len_to_disk(blocksize -
2695 (csum_size + EXT4_DIR_REC_LEN(1)),
2696 blocksize);
2697 else
2698 de->rec_len = ext4_rec_len_to_disk(
2699 EXT4_DIR_REC_LEN(de->name_len), blocksize);
2700 strcpy(de->name, "..");
2701 ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2702
2703 return ext4_next_entry(de, blocksize);
2704}
2705
2706static int ext4_init_new_dir(handle_t *handle, struct inode *dir,
2707 struct inode *inode)
2708{
2709 struct buffer_head *dir_block = NULL;
2710 struct ext4_dir_entry_2 *de;
2711 ext4_lblk_t block = 0;
2712 unsigned int blocksize = dir->i_sb->s_blocksize;
2713 int csum_size = 0;
2714 int err;
2715
2716 if (ext4_has_metadata_csum(dir->i_sb))
2717 csum_size = sizeof(struct ext4_dir_entry_tail);
2718
2719 if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
2720 err = ext4_try_create_inline_dir(handle, dir, inode);
2721 if (err < 0 && err != -ENOSPC)
2722 goto out;
2723 if (!err)
2724 goto out;
2725 }
2726
2727 inode->i_size = 0;
2728 dir_block = ext4_append(handle, inode, &block);
2729 if (IS_ERR(dir_block))
2730 return PTR_ERR(dir_block);
2731 de = (struct ext4_dir_entry_2 *)dir_block->b_data;
2732 ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0);
2733 set_nlink(inode, 2);
2734 if (csum_size)
2735 ext4_initialize_dirent_tail(dir_block, blocksize);
2736
2737 BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
2738 err = ext4_handle_dirty_dirblock(handle, inode, dir_block);
2739 if (err)
2740 goto out;
2741 set_buffer_verified(dir_block);
2742out:
2743 brelse(dir_block);
2744 return err;
2745}
2746
2747static 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 err = dquot_initialize(dir);
2757 if (err)
2758 return err;
2759
2760 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2761 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2762retry:
2763 inode = ext4_new_inode_start_handle(dir, S_IFDIR | mode,
2764 &dentry->d_name,
2765 0, NULL, EXT4_HT_DIR, credits);
2766 handle = ext4_journal_current_handle();
2767 err = PTR_ERR(inode);
2768 if (IS_ERR(inode))
2769 goto out_stop;
2770
2771 inode->i_op = &ext4_dir_inode_operations;
2772 inode->i_fop = &ext4_dir_operations;
2773 err = ext4_init_new_dir(handle, dir, inode);
2774 if (err)
2775 goto out_clear_inode;
2776 err = ext4_mark_inode_dirty(handle, inode);
2777 if (!err)
2778 err = ext4_add_entry(handle, dentry, inode);
2779 if (err) {
2780out_clear_inode:
2781 clear_nlink(inode);
2782 unlock_new_inode(inode);
2783 ext4_mark_inode_dirty(handle, inode);
2784 iput(inode);
2785 goto out_stop;
2786 }
2787 ext4_inc_count(handle, dir);
2788 ext4_update_dx_flag(dir);
2789 err = ext4_mark_inode_dirty(handle, dir);
2790 if (err)
2791 goto out_clear_inode;
2792 d_instantiate_new(dentry, inode);
2793 if (IS_DIRSYNC(dir))
2794 ext4_handle_sync(handle);
2795
2796out_stop:
2797 if (handle)
2798 ext4_journal_stop(handle);
2799 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2800 goto retry;
2801 return err;
2802}
2803
2804/*
2805 * routine to check that the specified directory is empty (for rmdir)
2806 */
2807bool ext4_empty_dir(struct inode *inode)
2808{
2809 unsigned int offset;
2810 struct buffer_head *bh;
2811 struct ext4_dir_entry_2 *de, *de1;
2812 struct super_block *sb;
2813
2814 if (ext4_has_inline_data(inode)) {
2815 int has_inline_data = 1;
2816 int ret;
2817
2818 ret = empty_inline_dir(inode, &has_inline_data);
2819 if (has_inline_data)
2820 return ret;
2821 }
2822
2823 sb = inode->i_sb;
2824 if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2)) {
2825 EXT4_ERROR_INODE(inode, "invalid size");
2826 return true;
2827 }
2828 /* The first directory block must not be a hole,
2829 * so treat it as DIRENT_HTREE
2830 */
2831 bh = ext4_read_dirblock(inode, 0, DIRENT_HTREE);
2832 if (IS_ERR(bh))
2833 return true;
2834
2835 de = (struct ext4_dir_entry_2 *) bh->b_data;
2836 de1 = ext4_next_entry(de, sb->s_blocksize);
2837 if (le32_to_cpu(de->inode) != inode->i_ino ||
2838 le32_to_cpu(de1->inode) == 0 ||
2839 strcmp(".", de->name) || strcmp("..", de1->name)) {
2840 ext4_warning_inode(inode, "directory missing '.' and/or '..'");
2841 brelse(bh);
2842 return true;
2843 }
2844 offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) +
2845 ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize);
2846 de = ext4_next_entry(de1, sb->s_blocksize);
2847 while (offset < inode->i_size) {
2848 if ((void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
2849 unsigned int lblock;
2850 brelse(bh);
2851 lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb);
2852 bh = ext4_read_dirblock(inode, lblock, EITHER);
2853 if (bh == NULL) {
2854 offset += sb->s_blocksize;
2855 continue;
2856 }
2857 if (IS_ERR(bh))
2858 return true;
2859 de = (struct ext4_dir_entry_2 *) bh->b_data;
2860 }
2861 if (ext4_check_dir_entry(inode, NULL, de, bh,
2862 bh->b_data, bh->b_size, offset)) {
2863 de = (struct ext4_dir_entry_2 *)(bh->b_data +
2864 sb->s_blocksize);
2865 offset = (offset | (sb->s_blocksize - 1)) + 1;
2866 continue;
2867 }
2868 if (le32_to_cpu(de->inode)) {
2869 brelse(bh);
2870 return false;
2871 }
2872 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
2873 de = ext4_next_entry(de, sb->s_blocksize);
2874 }
2875 brelse(bh);
2876 return true;
2877}
2878
2879/*
2880 * ext4_orphan_add() links an unlinked or truncated inode into a list of
2881 * such inodes, starting at the superblock, in case we crash before the
2882 * file is closed/deleted, or in case the inode truncate spans multiple
2883 * transactions and the last transaction is not recovered after a crash.
2884 *
2885 * At filesystem recovery time, we walk this list deleting unlinked
2886 * inodes and truncating linked inodes in ext4_orphan_cleanup().
2887 *
2888 * Orphan list manipulation functions must be called under i_mutex unless
2889 * we are just creating the inode or deleting it.
2890 */
2891int ext4_orphan_add(handle_t *handle, struct inode *inode)
2892{
2893 struct super_block *sb = inode->i_sb;
2894 struct ext4_sb_info *sbi = EXT4_SB(sb);
2895 struct ext4_iloc iloc;
2896 int err = 0, rc;
2897 bool dirty = false;
2898
2899 if (!sbi->s_journal || is_bad_inode(inode))
2900 return 0;
2901
2902 WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
2903 !inode_is_locked(inode));
2904 /*
2905 * Exit early if inode already is on orphan list. This is a big speedup
2906 * since we don't have to contend on the global s_orphan_lock.
2907 */
2908 if (!list_empty(&EXT4_I(inode)->i_orphan))
2909 return 0;
2910
2911 /*
2912 * Orphan handling is only valid for files with data blocks
2913 * being truncated, or files being unlinked. Note that we either
2914 * hold i_mutex, or the inode can not be referenced from outside,
2915 * so i_nlink should not be bumped due to race
2916 */
2917 J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2918 S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
2919
2920 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2921 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2922 if (err)
2923 goto out;
2924
2925 err = ext4_reserve_inode_write(handle, inode, &iloc);
2926 if (err)
2927 goto out;
2928
2929 mutex_lock(&sbi->s_orphan_lock);
2930 /*
2931 * Due to previous errors inode may be already a part of on-disk
2932 * orphan list. If so skip on-disk list modification.
2933 */
2934 if (!NEXT_ORPHAN(inode) || NEXT_ORPHAN(inode) >
2935 (le32_to_cpu(sbi->s_es->s_inodes_count))) {
2936 /* Insert this inode at the head of the on-disk orphan list */
2937 NEXT_ORPHAN(inode) = le32_to_cpu(sbi->s_es->s_last_orphan);
2938 sbi->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
2939 dirty = true;
2940 }
2941 list_add(&EXT4_I(inode)->i_orphan, &sbi->s_orphan);
2942 mutex_unlock(&sbi->s_orphan_lock);
2943
2944 if (dirty) {
2945 err = ext4_handle_dirty_super(handle, sb);
2946 rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
2947 if (!err)
2948 err = rc;
2949 if (err) {
2950 /*
2951 * We have to remove inode from in-memory list if
2952 * addition to on disk orphan list failed. Stray orphan
2953 * list entries can cause panics at unmount time.
2954 */
2955 mutex_lock(&sbi->s_orphan_lock);
2956 list_del_init(&EXT4_I(inode)->i_orphan);
2957 mutex_unlock(&sbi->s_orphan_lock);
2958 }
2959 } else
2960 brelse(iloc.bh);
2961
2962 jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
2963 jbd_debug(4, "orphan inode %lu will point to %d\n",
2964 inode->i_ino, NEXT_ORPHAN(inode));
2965out:
2966 ext4_std_error(sb, err);
2967 return err;
2968}
2969
2970/*
2971 * ext4_orphan_del() removes an unlinked or truncated inode from the list
2972 * of such inodes stored on disk, because it is finally being cleaned up.
2973 */
2974int ext4_orphan_del(handle_t *handle, struct inode *inode)
2975{
2976 struct list_head *prev;
2977 struct ext4_inode_info *ei = EXT4_I(inode);
2978 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2979 __u32 ino_next;
2980 struct ext4_iloc iloc;
2981 int err = 0;
2982
2983 if (!sbi->s_journal && !(sbi->s_mount_state & EXT4_ORPHAN_FS))
2984 return 0;
2985
2986 WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
2987 !inode_is_locked(inode));
2988 /* Do this quick check before taking global s_orphan_lock. */
2989 if (list_empty(&ei->i_orphan))
2990 return 0;
2991
2992 if (handle) {
2993 /* Grab inode buffer early before taking global s_orphan_lock */
2994 err = ext4_reserve_inode_write(handle, inode, &iloc);
2995 }
2996
2997 mutex_lock(&sbi->s_orphan_lock);
2998 jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
2999
3000 prev = ei->i_orphan.prev;
3001 list_del_init(&ei->i_orphan);
3002
3003 /* If we're on an error path, we may not have a valid
3004 * transaction handle with which to update the orphan list on
3005 * disk, but we still need to remove the inode from the linked
3006 * list in memory. */
3007 if (!handle || err) {
3008 mutex_unlock(&sbi->s_orphan_lock);
3009 goto out_err;
3010 }
3011
3012 ino_next = NEXT_ORPHAN(inode);
3013 if (prev == &sbi->s_orphan) {
3014 jbd_debug(4, "superblock will point to %u\n", ino_next);
3015 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
3016 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
3017 if (err) {
3018 mutex_unlock(&sbi->s_orphan_lock);
3019 goto out_brelse;
3020 }
3021 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
3022 mutex_unlock(&sbi->s_orphan_lock);
3023 err = ext4_handle_dirty_super(handle, inode->i_sb);
3024 } else {
3025 struct ext4_iloc iloc2;
3026 struct inode *i_prev =
3027 &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
3028
3029 jbd_debug(4, "orphan inode %lu will point to %u\n",
3030 i_prev->i_ino, ino_next);
3031 err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
3032 if (err) {
3033 mutex_unlock(&sbi->s_orphan_lock);
3034 goto out_brelse;
3035 }
3036 NEXT_ORPHAN(i_prev) = ino_next;
3037 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
3038 mutex_unlock(&sbi->s_orphan_lock);
3039 }
3040 if (err)
3041 goto out_brelse;
3042 NEXT_ORPHAN(inode) = 0;
3043 err = ext4_mark_iloc_dirty(handle, inode, &iloc);
3044out_err:
3045 ext4_std_error(inode->i_sb, err);
3046 return err;
3047
3048out_brelse:
3049 brelse(iloc.bh);
3050 goto out_err;
3051}
3052
3053static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
3054{
3055 int retval;
3056 struct inode *inode;
3057 struct buffer_head *bh;
3058 struct ext4_dir_entry_2 *de;
3059 handle_t *handle = NULL;
3060
3061 if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
3062 return -EIO;
3063
3064 /* Initialize quotas before so that eventual writes go in
3065 * separate transaction */
3066 retval = dquot_initialize(dir);
3067 if (retval)
3068 return retval;
3069 retval = dquot_initialize(d_inode(dentry));
3070 if (retval)
3071 return retval;
3072
3073 retval = -ENOENT;
3074 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
3075 if (IS_ERR(bh))
3076 return PTR_ERR(bh);
3077 if (!bh)
3078 goto end_rmdir;
3079
3080 inode = d_inode(dentry);
3081
3082 retval = -EFSCORRUPTED;
3083 if (le32_to_cpu(de->inode) != inode->i_ino)
3084 goto end_rmdir;
3085
3086 retval = -ENOTEMPTY;
3087 if (!ext4_empty_dir(inode))
3088 goto end_rmdir;
3089
3090 handle = ext4_journal_start(dir, EXT4_HT_DIR,
3091 EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
3092 if (IS_ERR(handle)) {
3093 retval = PTR_ERR(handle);
3094 handle = NULL;
3095 goto end_rmdir;
3096 }
3097
3098 if (IS_DIRSYNC(dir))
3099 ext4_handle_sync(handle);
3100
3101 retval = ext4_delete_entry(handle, dir, de, bh);
3102 if (retval)
3103 goto end_rmdir;
3104 if (!EXT4_DIR_LINK_EMPTY(inode))
3105 ext4_warning_inode(inode,
3106 "empty directory '%.*s' has too many links (%u)",
3107 dentry->d_name.len, dentry->d_name.name,
3108 inode->i_nlink);
3109 inode_inc_iversion(inode);
3110 clear_nlink(inode);
3111 /* There's no need to set i_disksize: the fact that i_nlink is
3112 * zero will ensure that the right thing happens during any
3113 * recovery. */
3114 inode->i_size = 0;
3115 ext4_orphan_add(handle, inode);
3116 inode->i_ctime = dir->i_ctime = dir->i_mtime = current_time(inode);
3117 ext4_mark_inode_dirty(handle, inode);
3118 ext4_dec_count(handle, dir);
3119 ext4_update_dx_flag(dir);
3120 ext4_mark_inode_dirty(handle, dir);
3121
3122#ifdef CONFIG_UNICODE
3123 /* VFS negative dentries are incompatible with Encoding and
3124 * Case-insensitiveness. Eventually we'll want avoid
3125 * invalidating the dentries here, alongside with returning the
3126 * negative dentries at ext4_lookup(), when it is better
3127 * supported by the VFS for the CI case.
3128 */
3129 if (IS_CASEFOLDED(dir))
3130 d_invalidate(dentry);
3131#endif
3132
3133end_rmdir:
3134 brelse(bh);
3135 if (handle)
3136 ext4_journal_stop(handle);
3137 return retval;
3138}
3139
3140static int ext4_unlink(struct inode *dir, struct dentry *dentry)
3141{
3142 int retval;
3143 struct inode *inode;
3144 struct buffer_head *bh;
3145 struct ext4_dir_entry_2 *de;
3146 handle_t *handle = NULL;
3147
3148 if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
3149 return -EIO;
3150
3151 trace_ext4_unlink_enter(dir, dentry);
3152 /* Initialize quotas before so that eventual writes go
3153 * in separate transaction */
3154 retval = dquot_initialize(dir);
3155 if (retval)
3156 return retval;
3157 retval = dquot_initialize(d_inode(dentry));
3158 if (retval)
3159 return retval;
3160
3161 retval = -ENOENT;
3162 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
3163 if (IS_ERR(bh))
3164 return PTR_ERR(bh);
3165 if (!bh)
3166 goto end_unlink;
3167
3168 inode = d_inode(dentry);
3169
3170 retval = -EFSCORRUPTED;
3171 if (le32_to_cpu(de->inode) != inode->i_ino)
3172 goto end_unlink;
3173
3174 handle = ext4_journal_start(dir, EXT4_HT_DIR,
3175 EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
3176 if (IS_ERR(handle)) {
3177 retval = PTR_ERR(handle);
3178 handle = NULL;
3179 goto end_unlink;
3180 }
3181
3182 if (IS_DIRSYNC(dir))
3183 ext4_handle_sync(handle);
3184
3185 if (inode->i_nlink == 0) {
3186 ext4_warning_inode(inode, "Deleting file '%.*s' with no links",
3187 dentry->d_name.len, dentry->d_name.name);
3188 set_nlink(inode, 1);
3189 }
3190 retval = ext4_delete_entry(handle, dir, de, bh);
3191 if (retval)
3192 goto end_unlink;
3193 dir->i_ctime = dir->i_mtime = current_time(dir);
3194 ext4_update_dx_flag(dir);
3195 ext4_mark_inode_dirty(handle, dir);
3196 drop_nlink(inode);
3197 if (!inode->i_nlink)
3198 ext4_orphan_add(handle, inode);
3199 inode->i_ctime = current_time(inode);
3200 ext4_mark_inode_dirty(handle, inode);
3201
3202#ifdef CONFIG_UNICODE
3203 /* VFS negative dentries are incompatible with Encoding and
3204 * Case-insensitiveness. Eventually we'll want avoid
3205 * invalidating the dentries here, alongside with returning the
3206 * negative dentries at ext4_lookup(), when it is better
3207 * supported by the VFS for the CI case.
3208 */
3209 if (IS_CASEFOLDED(dir))
3210 d_invalidate(dentry);
3211#endif
3212
3213end_unlink:
3214 brelse(bh);
3215 if (handle)
3216 ext4_journal_stop(handle);
3217 trace_ext4_unlink_exit(dentry, retval);
3218 return retval;
3219}
3220
3221static int ext4_symlink(struct inode *dir,
3222 struct dentry *dentry, const char *symname)
3223{
3224 handle_t *handle;
3225 struct inode *inode;
3226 int err, len = strlen(symname);
3227 int credits;
3228 struct fscrypt_str disk_link;
3229
3230 if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
3231 return -EIO;
3232
3233 err = fscrypt_prepare_symlink(dir, symname, len, dir->i_sb->s_blocksize,
3234 &disk_link);
3235 if (err)
3236 return err;
3237
3238 err = dquot_initialize(dir);
3239 if (err)
3240 return err;
3241
3242 if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
3243 /*
3244 * For non-fast symlinks, we just allocate inode and put it on
3245 * orphan list in the first transaction => we need bitmap,
3246 * group descriptor, sb, inode block, quota blocks, and
3247 * possibly selinux xattr blocks.
3248 */
3249 credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
3250 EXT4_XATTR_TRANS_BLOCKS;
3251 } else {
3252 /*
3253 * Fast symlink. We have to add entry to directory
3254 * (EXT4_DATA_TRANS_BLOCKS + EXT4_INDEX_EXTRA_TRANS_BLOCKS),
3255 * allocate new inode (bitmap, group descriptor, inode block,
3256 * quota blocks, sb is already counted in previous macros).
3257 */
3258 credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3259 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3;
3260 }
3261
3262 inode = ext4_new_inode_start_handle(dir, S_IFLNK|S_IRWXUGO,
3263 &dentry->d_name, 0, NULL,
3264 EXT4_HT_DIR, credits);
3265 handle = ext4_journal_current_handle();
3266 if (IS_ERR(inode)) {
3267 if (handle)
3268 ext4_journal_stop(handle);
3269 return PTR_ERR(inode);
3270 }
3271
3272 if (IS_ENCRYPTED(inode)) {
3273 err = fscrypt_encrypt_symlink(inode, symname, len, &disk_link);
3274 if (err)
3275 goto err_drop_inode;
3276 inode->i_op = &ext4_encrypted_symlink_inode_operations;
3277 }
3278
3279 if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
3280 if (!IS_ENCRYPTED(inode))
3281 inode->i_op = &ext4_symlink_inode_operations;
3282 inode_nohighmem(inode);
3283 ext4_set_aops(inode);
3284 /*
3285 * We cannot call page_symlink() with transaction started
3286 * because it calls into ext4_write_begin() which can wait
3287 * for transaction commit if we are running out of space
3288 * and thus we deadlock. So we have to stop transaction now
3289 * and restart it when symlink contents is written.
3290 *
3291 * To keep fs consistent in case of crash, we have to put inode
3292 * to orphan list in the mean time.
3293 */
3294 drop_nlink(inode);
3295 err = ext4_orphan_add(handle, inode);
3296 ext4_journal_stop(handle);
3297 handle = NULL;
3298 if (err)
3299 goto err_drop_inode;
3300 err = __page_symlink(inode, disk_link.name, disk_link.len, 1);
3301 if (err)
3302 goto err_drop_inode;
3303 /*
3304 * Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS
3305 * + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified
3306 */
3307 handle = ext4_journal_start(dir, EXT4_HT_DIR,
3308 EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3309 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1);
3310 if (IS_ERR(handle)) {
3311 err = PTR_ERR(handle);
3312 handle = NULL;
3313 goto err_drop_inode;
3314 }
3315 set_nlink(inode, 1);
3316 err = ext4_orphan_del(handle, inode);
3317 if (err)
3318 goto err_drop_inode;
3319 } else {
3320 /* clear the extent format for fast symlink */
3321 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
3322 if (!IS_ENCRYPTED(inode)) {
3323 inode->i_op = &ext4_fast_symlink_inode_operations;
3324 inode->i_link = (char *)&EXT4_I(inode)->i_data;
3325 }
3326 memcpy((char *)&EXT4_I(inode)->i_data, disk_link.name,
3327 disk_link.len);
3328 inode->i_size = disk_link.len - 1;
3329 }
3330 EXT4_I(inode)->i_disksize = inode->i_size;
3331 err = ext4_add_nondir(handle, dentry, inode);
3332 if (!err && IS_DIRSYNC(dir))
3333 ext4_handle_sync(handle);
3334
3335 if (handle)
3336 ext4_journal_stop(handle);
3337 goto out_free_encrypted_link;
3338
3339err_drop_inode:
3340 if (handle)
3341 ext4_journal_stop(handle);
3342 clear_nlink(inode);
3343 unlock_new_inode(inode);
3344 iput(inode);
3345out_free_encrypted_link:
3346 if (disk_link.name != (unsigned char *)symname)
3347 kfree(disk_link.name);
3348 return err;
3349}
3350
3351static int ext4_link(struct dentry *old_dentry,
3352 struct inode *dir, struct dentry *dentry)
3353{
3354 handle_t *handle;
3355 struct inode *inode = d_inode(old_dentry);
3356 int err, retries = 0;
3357
3358 if (inode->i_nlink >= EXT4_LINK_MAX)
3359 return -EMLINK;
3360
3361 err = fscrypt_prepare_link(old_dentry, dir, dentry);
3362 if (err)
3363 return err;
3364
3365 if ((ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT)) &&
3366 (!projid_eq(EXT4_I(dir)->i_projid,
3367 EXT4_I(old_dentry->d_inode)->i_projid)))
3368 return -EXDEV;
3369
3370 err = dquot_initialize(dir);
3371 if (err)
3372 return err;
3373
3374retry:
3375 handle = ext4_journal_start(dir, EXT4_HT_DIR,
3376 (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3377 EXT4_INDEX_EXTRA_TRANS_BLOCKS) + 1);
3378 if (IS_ERR(handle))
3379 return PTR_ERR(handle);
3380
3381 if (IS_DIRSYNC(dir))
3382 ext4_handle_sync(handle);
3383
3384 inode->i_ctime = current_time(inode);
3385 ext4_inc_count(handle, inode);
3386 ihold(inode);
3387
3388 err = ext4_add_entry(handle, dentry, inode);
3389 if (!err) {
3390 ext4_mark_inode_dirty(handle, inode);
3391 /* this can happen only for tmpfile being
3392 * linked the first time
3393 */
3394 if (inode->i_nlink == 1)
3395 ext4_orphan_del(handle, inode);
3396 d_instantiate(dentry, inode);
3397 } else {
3398 drop_nlink(inode);
3399 iput(inode);
3400 }
3401 ext4_journal_stop(handle);
3402 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
3403 goto retry;
3404 return err;
3405}
3406
3407
3408/*
3409 * Try to find buffer head where contains the parent block.
3410 * It should be the inode block if it is inlined or the 1st block
3411 * if it is a normal dir.
3412 */
3413static struct buffer_head *ext4_get_first_dir_block(handle_t *handle,
3414 struct inode *inode,
3415 int *retval,
3416 struct ext4_dir_entry_2 **parent_de,
3417 int *inlined)
3418{
3419 struct buffer_head *bh;
3420
3421 if (!ext4_has_inline_data(inode)) {
3422 /* The first directory block must not be a hole, so
3423 * treat it as DIRENT_HTREE
3424 */
3425 bh = ext4_read_dirblock(inode, 0, DIRENT_HTREE);
3426 if (IS_ERR(bh)) {
3427 *retval = PTR_ERR(bh);
3428 return NULL;
3429 }
3430 *parent_de = ext4_next_entry(
3431 (struct ext4_dir_entry_2 *)bh->b_data,
3432 inode->i_sb->s_blocksize);
3433 return bh;
3434 }
3435
3436 *inlined = 1;
3437 return ext4_get_first_inline_block(inode, parent_de, retval);
3438}
3439
3440struct ext4_renament {
3441 struct inode *dir;
3442 struct dentry *dentry;
3443 struct inode *inode;
3444 bool is_dir;
3445 int dir_nlink_delta;
3446
3447 /* entry for "dentry" */
3448 struct buffer_head *bh;
3449 struct ext4_dir_entry_2 *de;
3450 int inlined;
3451
3452 /* entry for ".." in inode if it's a directory */
3453 struct buffer_head *dir_bh;
3454 struct ext4_dir_entry_2 *parent_de;
3455 int dir_inlined;
3456};
3457
3458static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent)
3459{
3460 int retval;
3461
3462 ent->dir_bh = ext4_get_first_dir_block(handle, ent->inode,
3463 &retval, &ent->parent_de,
3464 &ent->dir_inlined);
3465 if (!ent->dir_bh)
3466 return retval;
3467 if (le32_to_cpu(ent->parent_de->inode) != ent->dir->i_ino)
3468 return -EFSCORRUPTED;
3469 BUFFER_TRACE(ent->dir_bh, "get_write_access");
3470 return ext4_journal_get_write_access(handle, ent->dir_bh);
3471}
3472
3473static int ext4_rename_dir_finish(handle_t *handle, struct ext4_renament *ent,
3474 unsigned dir_ino)
3475{
3476 int retval;
3477
3478 ent->parent_de->inode = cpu_to_le32(dir_ino);
3479 BUFFER_TRACE(ent->dir_bh, "call ext4_handle_dirty_metadata");
3480 if (!ent->dir_inlined) {
3481 if (is_dx(ent->inode)) {
3482 retval = ext4_handle_dirty_dx_node(handle,
3483 ent->inode,
3484 ent->dir_bh);
3485 } else {
3486 retval = ext4_handle_dirty_dirblock(handle, ent->inode,
3487 ent->dir_bh);
3488 }
3489 } else {
3490 retval = ext4_mark_inode_dirty(handle, ent->inode);
3491 }
3492 if (retval) {
3493 ext4_std_error(ent->dir->i_sb, retval);
3494 return retval;
3495 }
3496 return 0;
3497}
3498
3499static int ext4_setent(handle_t *handle, struct ext4_renament *ent,
3500 unsigned ino, unsigned file_type)
3501{
3502 int retval;
3503
3504 BUFFER_TRACE(ent->bh, "get write access");
3505 retval = ext4_journal_get_write_access(handle, ent->bh);
3506 if (retval)
3507 return retval;
3508 ent->de->inode = cpu_to_le32(ino);
3509 if (ext4_has_feature_filetype(ent->dir->i_sb))
3510 ent->de->file_type = file_type;
3511 inode_inc_iversion(ent->dir);
3512 ent->dir->i_ctime = ent->dir->i_mtime =
3513 current_time(ent->dir);
3514 ext4_mark_inode_dirty(handle, ent->dir);
3515 BUFFER_TRACE(ent->bh, "call ext4_handle_dirty_metadata");
3516 if (!ent->inlined) {
3517 retval = ext4_handle_dirty_dirblock(handle, ent->dir, ent->bh);
3518 if (unlikely(retval)) {
3519 ext4_std_error(ent->dir->i_sb, retval);
3520 return retval;
3521 }
3522 }
3523 brelse(ent->bh);
3524 ent->bh = NULL;
3525
3526 return 0;
3527}
3528
3529static int ext4_find_delete_entry(handle_t *handle, struct inode *dir,
3530 const struct qstr *d_name)
3531{
3532 int retval = -ENOENT;
3533 struct buffer_head *bh;
3534 struct ext4_dir_entry_2 *de;
3535
3536 bh = ext4_find_entry(dir, d_name, &de, NULL);
3537 if (IS_ERR(bh))
3538 return PTR_ERR(bh);
3539 if (bh) {
3540 retval = ext4_delete_entry(handle, dir, de, bh);
3541 brelse(bh);
3542 }
3543 return retval;
3544}
3545
3546static void ext4_rename_delete(handle_t *handle, struct ext4_renament *ent,
3547 int force_reread)
3548{
3549 int retval;
3550 /*
3551 * ent->de could have moved from under us during htree split, so make
3552 * sure that we are deleting the right entry. We might also be pointing
3553 * to a stale entry in the unused part of ent->bh so just checking inum
3554 * and the name isn't enough.
3555 */
3556 if (le32_to_cpu(ent->de->inode) != ent->inode->i_ino ||
3557 ent->de->name_len != ent->dentry->d_name.len ||
3558 strncmp(ent->de->name, ent->dentry->d_name.name,
3559 ent->de->name_len) ||
3560 force_reread) {
3561 retval = ext4_find_delete_entry(handle, ent->dir,
3562 &ent->dentry->d_name);
3563 } else {
3564 retval = ext4_delete_entry(handle, ent->dir, ent->de, ent->bh);
3565 if (retval == -ENOENT) {
3566 retval = ext4_find_delete_entry(handle, ent->dir,
3567 &ent->dentry->d_name);
3568 }
3569 }
3570
3571 if (retval) {
3572 ext4_warning_inode(ent->dir,
3573 "Deleting old file: nlink %d, error=%d",
3574 ent->dir->i_nlink, retval);
3575 }
3576}
3577
3578static void ext4_update_dir_count(handle_t *handle, struct ext4_renament *ent)
3579{
3580 if (ent->dir_nlink_delta) {
3581 if (ent->dir_nlink_delta == -1)
3582 ext4_dec_count(handle, ent->dir);
3583 else
3584 ext4_inc_count(handle, ent->dir);
3585 ext4_mark_inode_dirty(handle, ent->dir);
3586 }
3587}
3588
3589static struct inode *ext4_whiteout_for_rename(struct ext4_renament *ent,
3590 int credits, handle_t **h)
3591{
3592 struct inode *wh;
3593 handle_t *handle;
3594 int retries = 0;
3595
3596 /*
3597 * for inode block, sb block, group summaries,
3598 * and inode bitmap
3599 */
3600 credits += (EXT4_MAXQUOTAS_TRANS_BLOCKS(ent->dir->i_sb) +
3601 EXT4_XATTR_TRANS_BLOCKS + 4);
3602retry:
3603 wh = ext4_new_inode_start_handle(ent->dir, S_IFCHR | WHITEOUT_MODE,
3604 &ent->dentry->d_name, 0, NULL,
3605 EXT4_HT_DIR, credits);
3606
3607 handle = ext4_journal_current_handle();
3608 if (IS_ERR(wh)) {
3609 if (handle)
3610 ext4_journal_stop(handle);
3611 if (PTR_ERR(wh) == -ENOSPC &&
3612 ext4_should_retry_alloc(ent->dir->i_sb, &retries))
3613 goto retry;
3614 } else {
3615 *h = handle;
3616 init_special_inode(wh, wh->i_mode, WHITEOUT_DEV);
3617 wh->i_op = &ext4_special_inode_operations;
3618 }
3619 return wh;
3620}
3621
3622/*
3623 * Anybody can rename anything with this: the permission checks are left to the
3624 * higher-level routines.
3625 *
3626 * n.b. old_{dentry,inode) refers to the source dentry/inode
3627 * while new_{dentry,inode) refers to the destination dentry/inode
3628 * This comes from rename(const char *oldpath, const char *newpath)
3629 */
3630static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
3631 struct inode *new_dir, struct dentry *new_dentry,
3632 unsigned int flags)
3633{
3634 handle_t *handle = NULL;
3635 struct ext4_renament old = {
3636 .dir = old_dir,
3637 .dentry = old_dentry,
3638 .inode = d_inode(old_dentry),
3639 };
3640 struct ext4_renament new = {
3641 .dir = new_dir,
3642 .dentry = new_dentry,
3643 .inode = d_inode(new_dentry),
3644 };
3645 int force_reread;
3646 int retval;
3647 struct inode *whiteout = NULL;
3648 int credits;
3649 u8 old_file_type;
3650
3651 if (new.inode && new.inode->i_nlink == 0) {
3652 EXT4_ERROR_INODE(new.inode,
3653 "target of rename is already freed");
3654 return -EFSCORRUPTED;
3655 }
3656
3657 if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT)) &&
3658 (!projid_eq(EXT4_I(new_dir)->i_projid,
3659 EXT4_I(old_dentry->d_inode)->i_projid)))
3660 return -EXDEV;
3661
3662 retval = dquot_initialize(old.dir);
3663 if (retval)
3664 return retval;
3665 retval = dquot_initialize(new.dir);
3666 if (retval)
3667 return retval;
3668
3669 /* Initialize quotas before so that eventual writes go
3670 * in separate transaction */
3671 if (new.inode) {
3672 retval = dquot_initialize(new.inode);
3673 if (retval)
3674 return retval;
3675 }
3676
3677 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, NULL);
3678 if (IS_ERR(old.bh))
3679 return PTR_ERR(old.bh);
3680 /*
3681 * Check for inode number is _not_ due to possible IO errors.
3682 * We might rmdir the source, keep it as pwd of some process
3683 * and merrily kill the link to whatever was created under the
3684 * same name. Goodbye sticky bit ;-<
3685 */
3686 retval = -ENOENT;
3687 if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3688 goto end_rename;
3689
3690 new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
3691 &new.de, &new.inlined);
3692 if (IS_ERR(new.bh)) {
3693 retval = PTR_ERR(new.bh);
3694 new.bh = NULL;
3695 goto end_rename;
3696 }
3697 if (new.bh) {
3698 if (!new.inode) {
3699 brelse(new.bh);
3700 new.bh = NULL;
3701 }
3702 }
3703 if (new.inode && !test_opt(new.dir->i_sb, NO_AUTO_DA_ALLOC))
3704 ext4_alloc_da_blocks(old.inode);
3705
3706 credits = (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3707 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
3708 if (!(flags & RENAME_WHITEOUT)) {
3709 handle = ext4_journal_start(old.dir, EXT4_HT_DIR, credits);
3710 if (IS_ERR(handle)) {
3711 retval = PTR_ERR(handle);
3712 handle = NULL;
3713 goto end_rename;
3714 }
3715 } else {
3716 whiteout = ext4_whiteout_for_rename(&old, credits, &handle);
3717 if (IS_ERR(whiteout)) {
3718 retval = PTR_ERR(whiteout);
3719 whiteout = NULL;
3720 goto end_rename;
3721 }
3722 }
3723
3724 if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3725 ext4_handle_sync(handle);
3726
3727 if (S_ISDIR(old.inode->i_mode)) {
3728 if (new.inode) {
3729 retval = -ENOTEMPTY;
3730 if (!ext4_empty_dir(new.inode))
3731 goto end_rename;
3732 } else {
3733 retval = -EMLINK;
3734 if (new.dir != old.dir && EXT4_DIR_LINK_MAX(new.dir))
3735 goto end_rename;
3736 }
3737 retval = ext4_rename_dir_prepare(handle, &old);
3738 if (retval)
3739 goto end_rename;
3740 }
3741 /*
3742 * If we're renaming a file within an inline_data dir and adding or
3743 * setting the new dirent causes a conversion from inline_data to
3744 * extents/blockmap, we need to force the dirent delete code to
3745 * re-read the directory, or else we end up trying to delete a dirent
3746 * from what is now the extent tree root (or a block map).
3747 */
3748 force_reread = (new.dir->i_ino == old.dir->i_ino &&
3749 ext4_test_inode_flag(new.dir, EXT4_INODE_INLINE_DATA));
3750
3751 old_file_type = old.de->file_type;
3752 if (whiteout) {
3753 /*
3754 * Do this before adding a new entry, so the old entry is sure
3755 * to be still pointing to the valid old entry.
3756 */
3757 retval = ext4_setent(handle, &old, whiteout->i_ino,
3758 EXT4_FT_CHRDEV);
3759 if (retval)
3760 goto end_rename;
3761 ext4_mark_inode_dirty(handle, whiteout);
3762 }
3763 if (!new.bh) {
3764 retval = ext4_add_entry(handle, new.dentry, old.inode);
3765 if (retval)
3766 goto end_rename;
3767 } else {
3768 retval = ext4_setent(handle, &new,
3769 old.inode->i_ino, old_file_type);
3770 if (retval)
3771 goto end_rename;
3772 }
3773 if (force_reread)
3774 force_reread = !ext4_test_inode_flag(new.dir,
3775 EXT4_INODE_INLINE_DATA);
3776
3777 /*
3778 * Like most other Unix systems, set the ctime for inodes on a
3779 * rename.
3780 */
3781 old.inode->i_ctime = current_time(old.inode);
3782 ext4_mark_inode_dirty(handle, old.inode);
3783
3784 if (!whiteout) {
3785 /*
3786 * ok, that's it
3787 */
3788 ext4_rename_delete(handle, &old, force_reread);
3789 }
3790
3791 if (new.inode) {
3792 ext4_dec_count(handle, new.inode);
3793 new.inode->i_ctime = current_time(new.inode);
3794 }
3795 old.dir->i_ctime = old.dir->i_mtime = current_time(old.dir);
3796 ext4_update_dx_flag(old.dir);
3797 if (old.dir_bh) {
3798 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
3799 if (retval)
3800 goto end_rename;
3801
3802 ext4_dec_count(handle, old.dir);
3803 if (new.inode) {
3804 /* checked ext4_empty_dir above, can't have another
3805 * parent, ext4_dec_count() won't work for many-linked
3806 * dirs */
3807 clear_nlink(new.inode);
3808 } else {
3809 ext4_inc_count(handle, new.dir);
3810 ext4_update_dx_flag(new.dir);
3811 ext4_mark_inode_dirty(handle, new.dir);
3812 }
3813 }
3814 ext4_mark_inode_dirty(handle, old.dir);
3815 if (new.inode) {
3816 ext4_mark_inode_dirty(handle, new.inode);
3817 if (!new.inode->i_nlink)
3818 ext4_orphan_add(handle, new.inode);
3819 }
3820 retval = 0;
3821
3822end_rename:
3823 brelse(old.dir_bh);
3824 brelse(old.bh);
3825 brelse(new.bh);
3826 if (whiteout) {
3827 if (retval)
3828 drop_nlink(whiteout);
3829 unlock_new_inode(whiteout);
3830 iput(whiteout);
3831 }
3832 if (handle)
3833 ext4_journal_stop(handle);
3834 return retval;
3835}
3836
3837static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
3838 struct inode *new_dir, struct dentry *new_dentry)
3839{
3840 handle_t *handle = NULL;
3841 struct ext4_renament old = {
3842 .dir = old_dir,
3843 .dentry = old_dentry,
3844 .inode = d_inode(old_dentry),
3845 };
3846 struct ext4_renament new = {
3847 .dir = new_dir,
3848 .dentry = new_dentry,
3849 .inode = d_inode(new_dentry),
3850 };
3851 u8 new_file_type;
3852 int retval;
3853 struct timespec64 ctime;
3854
3855 if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT) &&
3856 !projid_eq(EXT4_I(new_dir)->i_projid,
3857 EXT4_I(old_dentry->d_inode)->i_projid)) ||
3858 (ext4_test_inode_flag(old_dir, EXT4_INODE_PROJINHERIT) &&
3859 !projid_eq(EXT4_I(old_dir)->i_projid,
3860 EXT4_I(new_dentry->d_inode)->i_projid)))
3861 return -EXDEV;
3862
3863 retval = dquot_initialize(old.dir);
3864 if (retval)
3865 return retval;
3866 retval = dquot_initialize(new.dir);
3867 if (retval)
3868 return retval;
3869
3870 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name,
3871 &old.de, &old.inlined);
3872 if (IS_ERR(old.bh))
3873 return PTR_ERR(old.bh);
3874 /*
3875 * Check for inode number is _not_ due to possible IO errors.
3876 * We might rmdir the source, keep it as pwd of some process
3877 * and merrily kill the link to whatever was created under the
3878 * same name. Goodbye sticky bit ;-<
3879 */
3880 retval = -ENOENT;
3881 if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3882 goto end_rename;
3883
3884 new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
3885 &new.de, &new.inlined);
3886 if (IS_ERR(new.bh)) {
3887 retval = PTR_ERR(new.bh);
3888 new.bh = NULL;
3889 goto end_rename;
3890 }
3891
3892 /* RENAME_EXCHANGE case: old *and* new must both exist */
3893 if (!new.bh || le32_to_cpu(new.de->inode) != new.inode->i_ino)
3894 goto end_rename;
3895
3896 handle = ext4_journal_start(old.dir, EXT4_HT_DIR,
3897 (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3898 2 * EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2));
3899 if (IS_ERR(handle)) {
3900 retval = PTR_ERR(handle);
3901 handle = NULL;
3902 goto end_rename;
3903 }
3904
3905 if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3906 ext4_handle_sync(handle);
3907
3908 if (S_ISDIR(old.inode->i_mode)) {
3909 old.is_dir = true;
3910 retval = ext4_rename_dir_prepare(handle, &old);
3911 if (retval)
3912 goto end_rename;
3913 }
3914 if (S_ISDIR(new.inode->i_mode)) {
3915 new.is_dir = true;
3916 retval = ext4_rename_dir_prepare(handle, &new);
3917 if (retval)
3918 goto end_rename;
3919 }
3920
3921 /*
3922 * Other than the special case of overwriting a directory, parents'
3923 * nlink only needs to be modified if this is a cross directory rename.
3924 */
3925 if (old.dir != new.dir && old.is_dir != new.is_dir) {
3926 old.dir_nlink_delta = old.is_dir ? -1 : 1;
3927 new.dir_nlink_delta = -old.dir_nlink_delta;
3928 retval = -EMLINK;
3929 if ((old.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(old.dir)) ||
3930 (new.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(new.dir)))
3931 goto end_rename;
3932 }
3933
3934 new_file_type = new.de->file_type;
3935 retval = ext4_setent(handle, &new, old.inode->i_ino, old.de->file_type);
3936 if (retval)
3937 goto end_rename;
3938
3939 retval = ext4_setent(handle, &old, new.inode->i_ino, new_file_type);
3940 if (retval)
3941 goto end_rename;
3942
3943 /*
3944 * Like most other Unix systems, set the ctime for inodes on a
3945 * rename.
3946 */
3947 ctime = current_time(old.inode);
3948 old.inode->i_ctime = ctime;
3949 new.inode->i_ctime = ctime;
3950 ext4_mark_inode_dirty(handle, old.inode);
3951 ext4_mark_inode_dirty(handle, new.inode);
3952
3953 if (old.dir_bh) {
3954 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
3955 if (retval)
3956 goto end_rename;
3957 }
3958 if (new.dir_bh) {
3959 retval = ext4_rename_dir_finish(handle, &new, old.dir->i_ino);
3960 if (retval)
3961 goto end_rename;
3962 }
3963 ext4_update_dir_count(handle, &old);
3964 ext4_update_dir_count(handle, &new);
3965 retval = 0;
3966
3967end_rename:
3968 brelse(old.dir_bh);
3969 brelse(new.dir_bh);
3970 brelse(old.bh);
3971 brelse(new.bh);
3972 if (handle)
3973 ext4_journal_stop(handle);
3974 return retval;
3975}
3976
3977static int ext4_rename2(struct inode *old_dir, struct dentry *old_dentry,
3978 struct inode *new_dir, struct dentry *new_dentry,
3979 unsigned int flags)
3980{
3981 int err;
3982
3983 if (unlikely(ext4_forced_shutdown(EXT4_SB(old_dir->i_sb))))
3984 return -EIO;
3985
3986 if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
3987 return -EINVAL;
3988
3989 err = fscrypt_prepare_rename(old_dir, old_dentry, new_dir, new_dentry,
3990 flags);
3991 if (err)
3992 return err;
3993
3994 if (flags & RENAME_EXCHANGE) {
3995 return ext4_cross_rename(old_dir, old_dentry,
3996 new_dir, new_dentry);
3997 }
3998
3999 return ext4_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
4000}
4001
4002/*
4003 * directories can handle most operations...
4004 */
4005const struct inode_operations ext4_dir_inode_operations = {
4006 .create = ext4_create,
4007 .lookup = ext4_lookup,
4008 .link = ext4_link,
4009 .unlink = ext4_unlink,
4010 .symlink = ext4_symlink,
4011 .mkdir = ext4_mkdir,
4012 .rmdir = ext4_rmdir,
4013 .mknod = ext4_mknod,
4014 .tmpfile = ext4_tmpfile,
4015 .rename = ext4_rename2,
4016 .setattr = ext4_setattr,
4017 .getattr = ext4_getattr,
4018 .listxattr = ext4_listxattr,
4019 .get_acl = ext4_get_acl,
4020 .set_acl = ext4_set_acl,
4021 .fiemap = ext4_fiemap,
4022};
4023
4024const struct inode_operations ext4_special_inode_operations = {
4025 .setattr = ext4_setattr,
4026 .getattr = ext4_getattr,
4027 .listxattr = ext4_listxattr,
4028 .get_acl = ext4_get_acl,
4029 .set_acl = ext4_set_acl,
4030};