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
53 static struct buffer_head *ext4_append(handle_t *handle,
54 struct inode *inode,
55 ext4_lblk_t *block)
56 {
57 struct ext4_map_blocks map;
58 struct buffer_head *bh;
59 int err;
60
61 if (unlikely(EXT4_SB(inode->i_sb)->s_max_dir_size_kb &&
62 ((inode->i_size >> 10) >=
63 EXT4_SB(inode->i_sb)->s_max_dir_size_kb)))
64 return ERR_PTR(-ENOSPC);
65
66 *block = inode->i_size >> inode->i_sb->s_blocksize_bits;
67 map.m_lblk = *block;
68 map.m_len = 1;
69
70 /*
71 * We're appending new directory block. Make sure the block is not
72 * allocated yet, otherwise we will end up corrupting the
73 * directory.
74 */
75 err = ext4_map_blocks(NULL, inode, &map, 0);
76 if (err < 0)
77 return ERR_PTR(err);
78 if (err) {
79 EXT4_ERROR_INODE(inode, "Logical block already allocated");
80 return ERR_PTR(-EFSCORRUPTED);
81 }
82
83 bh = ext4_bread(handle, inode, *block, EXT4_GET_BLOCKS_CREATE);
84 if (IS_ERR(bh))
85 return bh;
86 inode->i_size += inode->i_sb->s_blocksize;
87 EXT4_I(inode)->i_disksize = inode->i_size;
88 err = ext4_mark_inode_dirty(handle, inode);
89 if (err)
90 goto out;
91 BUFFER_TRACE(bh, "get_write_access");
92 err = ext4_journal_get_write_access(handle, inode->i_sb, bh,
93 EXT4_JTR_NONE);
94 if (err)
95 goto out;
96 return bh;
97
98 out:
99 brelse(bh);
100 ext4_std_error(inode->i_sb, err);
101 return ERR_PTR(err);
102 }
103
104 static int ext4_dx_csum_verify(struct inode *inode,
105 struct ext4_dir_entry *dirent);
106
107 /*
108 * Hints to ext4_read_dirblock regarding whether we expect a directory
109 * block being read to be an index block, or a block containing
110 * directory entries (and if the latter, whether it was found via a
111 * logical block in an htree index block). This is used to control
112 * what sort of sanity checkinig ext4_read_dirblock() will do on the
113 * directory block read from the storage device. EITHER will means
114 * the caller doesn't know what kind of directory block will be read,
115 * so no specific verification will be done.
116 */
117 typedef enum {
118 EITHER, INDEX, DIRENT, DIRENT_HTREE
119 } dirblock_type_t;
120
121 #define ext4_read_dirblock(inode, block, type) \
122 __ext4_read_dirblock((inode), (block), (type), __func__, __LINE__)
123
124 static struct buffer_head *__ext4_read_dirblock(struct inode *inode,
125 ext4_lblk_t block,
126 dirblock_type_t type,
127 const char *func,
128 unsigned int line)
129 {
130 struct buffer_head *bh;
131 struct ext4_dir_entry *dirent;
132 int is_dx_block = 0;
133
134 if (block >= inode->i_size >> inode->i_blkbits) {
135 ext4_error_inode(inode, func, line, block,
136 "Attempting to read directory block (%u) that is past i_size (%llu)",
137 block, inode->i_size);
138 return ERR_PTR(-EFSCORRUPTED);
139 }
140
141 if (ext4_simulate_fail(inode->i_sb, EXT4_SIM_DIRBLOCK_EIO))
142 bh = ERR_PTR(-EIO);
143 else
144 bh = ext4_bread(NULL, inode, block, 0);
145 if (IS_ERR(bh)) {
146 __ext4_warning(inode->i_sb, func, line,
147 "inode #%lu: lblock %lu: comm %s: "
148 "error %ld reading directory block",
149 inode->i_ino, (unsigned long)block,
150 current->comm, PTR_ERR(bh));
151
152 return bh;
153 }
154 /* The first directory block must not be a hole. */
155 if (!bh && (type == INDEX || type == DIRENT_HTREE || block == 0)) {
156 ext4_error_inode(inode, func, line, block,
157 "Directory hole found for htree %s block %u",
158 (type == INDEX) ? "index" : "leaf", block);
159 return ERR_PTR(-EFSCORRUPTED);
160 }
161 if (!bh)
162 return NULL;
163 dirent = (struct ext4_dir_entry *) bh->b_data;
164 /* Determine whether or not we have an index block */
165 if (is_dx(inode)) {
166 if (block == 0)
167 is_dx_block = 1;
168 else if (ext4_rec_len_from_disk(dirent->rec_len,
169 inode->i_sb->s_blocksize) ==
170 inode->i_sb->s_blocksize)
171 is_dx_block = 1;
172 }
173 if (!is_dx_block && type == INDEX) {
174 ext4_error_inode(inode, func, line, block,
175 "directory leaf block found instead of index block");
176 brelse(bh);
177 return ERR_PTR(-EFSCORRUPTED);
178 }
179 if (!ext4_has_metadata_csum(inode->i_sb) ||
180 buffer_verified(bh))
181 return bh;
182
183 /*
184 * An empty leaf block can get mistaken for a index block; for
185 * this reason, we can only check the index checksum when the
186 * caller is sure it should be an index block.
187 */
188 if (is_dx_block && type == INDEX) {
189 if (ext4_dx_csum_verify(inode, dirent) &&
190 !ext4_simulate_fail(inode->i_sb, EXT4_SIM_DIRBLOCK_CRC))
191 set_buffer_verified(bh);
192 else {
193 ext4_error_inode_err(inode, func, line, block,
194 EFSBADCRC,
195 "Directory index failed checksum");
196 brelse(bh);
197 return ERR_PTR(-EFSBADCRC);
198 }
199 }
200 if (!is_dx_block) {
201 if (ext4_dirblock_csum_verify(inode, bh) &&
202 !ext4_simulate_fail(inode->i_sb, EXT4_SIM_DIRBLOCK_CRC))
203 set_buffer_verified(bh);
204 else {
205 ext4_error_inode_err(inode, func, line, block,
206 EFSBADCRC,
207 "Directory block failed checksum");
208 brelse(bh);
209 return ERR_PTR(-EFSBADCRC);
210 }
211 }
212 return bh;
213 }
214
215 #ifdef DX_DEBUG
216 #define dxtrace(command) command
217 #else
218 #define dxtrace(command)
219 #endif
220
221 struct fake_dirent
222 {
223 __le32 inode;
224 __le16 rec_len;
225 u8 name_len;
226 u8 file_type;
227 };
228
229 struct dx_countlimit
230 {
231 __le16 limit;
232 __le16 count;
233 };
234
235 struct dx_entry
236 {
237 __le32 hash;
238 __le32 block;
239 };
240
241 /*
242 * dx_root_info is laid out so that if it should somehow get overlaid by a
243 * dirent the two low bits of the hash version will be zero. Therefore, the
244 * hash version mod 4 should never be 0. Sincerely, the paranoia department.
245 */
246
247 struct dx_root
248 {
249 struct fake_dirent dot;
250 char dot_name[4];
251 struct fake_dirent dotdot;
252 char dotdot_name[4];
253 struct dx_root_info
254 {
255 __le32 reserved_zero;
256 u8 hash_version;
257 u8 info_length; /* 8 */
258 u8 indirect_levels;
259 u8 unused_flags;
260 }
261 info;
262 struct dx_entry entries[];
263 };
264
265 struct dx_node
266 {
267 struct fake_dirent fake;
268 struct dx_entry entries[];
269 };
270
271
272 struct dx_frame
273 {
274 struct buffer_head *bh;
275 struct dx_entry *entries;
276 struct dx_entry *at;
277 };
278
279 struct dx_map_entry
280 {
281 u32 hash;
282 u16 offs;
283 u16 size;
284 };
285
286 /*
287 * This goes at the end of each htree block.
288 */
289 struct dx_tail {
290 u32 dt_reserved;
291 __le32 dt_checksum; /* crc32c(uuid+inum+dirblock) */
292 };
293
294 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
295 static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
296 static inline unsigned dx_get_hash(struct dx_entry *entry);
297 static void dx_set_hash(struct dx_entry *entry, unsigned value);
298 static unsigned dx_get_count(struct dx_entry *entries);
299 static unsigned dx_get_limit(struct dx_entry *entries);
300 static void dx_set_count(struct dx_entry *entries, unsigned value);
301 static void dx_set_limit(struct dx_entry *entries, unsigned value);
302 static unsigned dx_root_limit(struct inode *dir, unsigned infosize);
303 static unsigned dx_node_limit(struct inode *dir);
304 static struct dx_frame *dx_probe(struct ext4_filename *fname,
305 struct inode *dir,
306 struct dx_hash_info *hinfo,
307 struct dx_frame *frame);
308 static void dx_release(struct dx_frame *frames);
309 static int dx_make_map(struct inode *dir, struct buffer_head *bh,
310 struct dx_hash_info *hinfo,
311 struct dx_map_entry *map_tail);
312 static void dx_sort_map(struct dx_map_entry *map, unsigned count);
313 static struct ext4_dir_entry_2 *dx_move_dirents(struct inode *dir, char *from,
314 char *to, struct dx_map_entry *offsets,
315 int count, unsigned int blocksize);
316 static struct ext4_dir_entry_2 *dx_pack_dirents(struct inode *dir, char *base,
317 unsigned int blocksize);
318 static void dx_insert_block(struct dx_frame *frame,
319 u32 hash, ext4_lblk_t block);
320 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
321 struct dx_frame *frame,
322 struct dx_frame *frames,
323 __u32 *start_hash);
324 static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
325 struct ext4_filename *fname,
326 struct ext4_dir_entry_2 **res_dir);
327 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
328 struct inode *dir, struct inode *inode);
329
330 /* checksumming functions */
331 void ext4_initialize_dirent_tail(struct buffer_head *bh,
332 unsigned int blocksize)
333 {
334 struct ext4_dir_entry_tail *t = EXT4_DIRENT_TAIL(bh->b_data, blocksize);
335
336 memset(t, 0, sizeof(struct ext4_dir_entry_tail));
337 t->det_rec_len = ext4_rec_len_to_disk(
338 sizeof(struct ext4_dir_entry_tail), blocksize);
339 t->det_reserved_ft = EXT4_FT_DIR_CSUM;
340 }
341
342 /* Walk through a dirent block to find a checksum "dirent" at the tail */
343 static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode,
344 struct buffer_head *bh)
345 {
346 struct ext4_dir_entry_tail *t;
347 int blocksize = EXT4_BLOCK_SIZE(inode->i_sb);
348
349 #ifdef PARANOID
350 struct ext4_dir_entry *d, *top;
351
352 d = (struct ext4_dir_entry *)bh->b_data;
353 top = (struct ext4_dir_entry *)(bh->b_data +
354 (blocksize - sizeof(struct ext4_dir_entry_tail)));
355 while (d < top && ext4_rec_len_from_disk(d->rec_len, blocksize))
356 d = (struct ext4_dir_entry *)(((void *)d) +
357 ext4_rec_len_from_disk(d->rec_len, blocksize));
358
359 if (d != top)
360 return NULL;
361
362 t = (struct ext4_dir_entry_tail *)d;
363 #else
364 t = EXT4_DIRENT_TAIL(bh->b_data, EXT4_BLOCK_SIZE(inode->i_sb));
365 #endif
366
367 if (t->det_reserved_zero1 ||
368 (ext4_rec_len_from_disk(t->det_rec_len, blocksize) !=
369 sizeof(struct ext4_dir_entry_tail)) ||
370 t->det_reserved_zero2 ||
371 t->det_reserved_ft != EXT4_FT_DIR_CSUM)
372 return NULL;
373
374 return t;
375 }
376
377 static __le32 ext4_dirblock_csum(struct inode *inode, void *dirent, int size)
378 {
379 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
380 struct ext4_inode_info *ei = EXT4_I(inode);
381 __u32 csum;
382
383 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
384 return cpu_to_le32(csum);
385 }
386
387 #define warn_no_space_for_csum(inode) \
388 __warn_no_space_for_csum((inode), __func__, __LINE__)
389
390 static void __warn_no_space_for_csum(struct inode *inode, const char *func,
391 unsigned int line)
392 {
393 __ext4_warning_inode(inode, func, line,
394 "No space for directory leaf checksum. Please run e2fsck -D.");
395 }
396
397 int ext4_dirblock_csum_verify(struct inode *inode, struct buffer_head *bh)
398 {
399 struct ext4_dir_entry_tail *t;
400
401 if (!ext4_has_metadata_csum(inode->i_sb))
402 return 1;
403
404 t = get_dirent_tail(inode, bh);
405 if (!t) {
406 warn_no_space_for_csum(inode);
407 return 0;
408 }
409
410 if (t->det_checksum != ext4_dirblock_csum(inode, bh->b_data,
411 (char *)t - bh->b_data))
412 return 0;
413
414 return 1;
415 }
416
417 static void ext4_dirblock_csum_set(struct inode *inode,
418 struct buffer_head *bh)
419 {
420 struct ext4_dir_entry_tail *t;
421
422 if (!ext4_has_metadata_csum(inode->i_sb))
423 return;
424
425 t = get_dirent_tail(inode, bh);
426 if (!t) {
427 warn_no_space_for_csum(inode);
428 return;
429 }
430
431 t->det_checksum = ext4_dirblock_csum(inode, bh->b_data,
432 (char *)t - bh->b_data);
433 }
434
435 int ext4_handle_dirty_dirblock(handle_t *handle,
436 struct inode *inode,
437 struct buffer_head *bh)
438 {
439 ext4_dirblock_csum_set(inode, bh);
440 return ext4_handle_dirty_metadata(handle, inode, bh);
441 }
442
443 static struct dx_countlimit *get_dx_countlimit(struct inode *inode,
444 struct ext4_dir_entry *dirent,
445 int *offset)
446 {
447 struct ext4_dir_entry *dp;
448 struct dx_root_info *root;
449 int count_offset;
450 int blocksize = EXT4_BLOCK_SIZE(inode->i_sb);
451 unsigned int rlen = ext4_rec_len_from_disk(dirent->rec_len, blocksize);
452
453 if (rlen == blocksize)
454 count_offset = 8;
455 else if (rlen == 12) {
456 dp = (struct ext4_dir_entry *)(((void *)dirent) + 12);
457 if (ext4_rec_len_from_disk(dp->rec_len, blocksize) != blocksize - 12)
458 return NULL;
459 root = (struct dx_root_info *)(((void *)dp + 12));
460 if (root->reserved_zero ||
461 root->info_length != sizeof(struct dx_root_info))
462 return NULL;
463 count_offset = 32;
464 } else
465 return NULL;
466
467 if (offset)
468 *offset = count_offset;
469 return (struct dx_countlimit *)(((void *)dirent) + count_offset);
470 }
471
472 static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent,
473 int count_offset, int count, struct dx_tail *t)
474 {
475 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
476 struct ext4_inode_info *ei = EXT4_I(inode);
477 __u32 csum;
478 int size;
479 __u32 dummy_csum = 0;
480 int offset = offsetof(struct dx_tail, dt_checksum);
481
482 size = count_offset + (count * sizeof(struct dx_entry));
483 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
484 csum = ext4_chksum(sbi, csum, (__u8 *)t, offset);
485 csum = ext4_chksum(sbi, csum, (__u8 *)&dummy_csum, sizeof(dummy_csum));
486
487 return cpu_to_le32(csum);
488 }
489
490 static int ext4_dx_csum_verify(struct inode *inode,
491 struct ext4_dir_entry *dirent)
492 {
493 struct dx_countlimit *c;
494 struct dx_tail *t;
495 int count_offset, limit, count;
496
497 if (!ext4_has_metadata_csum(inode->i_sb))
498 return 1;
499
500 c = get_dx_countlimit(inode, dirent, &count_offset);
501 if (!c) {
502 EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D.");
503 return 0;
504 }
505 limit = le16_to_cpu(c->limit);
506 count = le16_to_cpu(c->count);
507 if (count_offset + (limit * sizeof(struct dx_entry)) >
508 EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
509 warn_no_space_for_csum(inode);
510 return 0;
511 }
512 t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
513
514 if (t->dt_checksum != ext4_dx_csum(inode, dirent, count_offset,
515 count, t))
516 return 0;
517 return 1;
518 }
519
520 static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent)
521 {
522 struct dx_countlimit *c;
523 struct dx_tail *t;
524 int count_offset, limit, count;
525
526 if (!ext4_has_metadata_csum(inode->i_sb))
527 return;
528
529 c = get_dx_countlimit(inode, dirent, &count_offset);
530 if (!c) {
531 EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D.");
532 return;
533 }
534 limit = le16_to_cpu(c->limit);
535 count = le16_to_cpu(c->count);
536 if (count_offset + (limit * sizeof(struct dx_entry)) >
537 EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
538 warn_no_space_for_csum(inode);
539 return;
540 }
541 t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
542
543 t->dt_checksum = ext4_dx_csum(inode, dirent, count_offset, count, t);
544 }
545
546 static inline int ext4_handle_dirty_dx_node(handle_t *handle,
547 struct inode *inode,
548 struct buffer_head *bh)
549 {
550 ext4_dx_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
551 return ext4_handle_dirty_metadata(handle, inode, bh);
552 }
553
554 /*
555 * p is at least 6 bytes before the end of page
556 */
557 static inline struct ext4_dir_entry_2 *
558 ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
559 {
560 return (struct ext4_dir_entry_2 *)((char *)p +
561 ext4_rec_len_from_disk(p->rec_len, blocksize));
562 }
563
564 /*
565 * Future: use high four bits of block for coalesce-on-delete flags
566 * Mask them off for now.
567 */
568
569 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
570 {
571 return le32_to_cpu(entry->block) & 0x0fffffff;
572 }
573
574 static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
575 {
576 entry->block = cpu_to_le32(value);
577 }
578
579 static inline unsigned dx_get_hash(struct dx_entry *entry)
580 {
581 return le32_to_cpu(entry->hash);
582 }
583
584 static inline void dx_set_hash(struct dx_entry *entry, unsigned value)
585 {
586 entry->hash = cpu_to_le32(value);
587 }
588
589 static inline unsigned dx_get_count(struct dx_entry *entries)
590 {
591 return le16_to_cpu(((struct dx_countlimit *) entries)->count);
592 }
593
594 static inline unsigned dx_get_limit(struct dx_entry *entries)
595 {
596 return le16_to_cpu(((struct dx_countlimit *) entries)->limit);
597 }
598
599 static inline void dx_set_count(struct dx_entry *entries, unsigned value)
600 {
601 ((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
602 }
603
604 static inline void dx_set_limit(struct dx_entry *entries, unsigned value)
605 {
606 ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
607 }
608
609 static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
610 {
611 unsigned int entry_space = dir->i_sb->s_blocksize -
612 ext4_dir_rec_len(1, NULL) -
613 ext4_dir_rec_len(2, NULL) - infosize;
614
615 if (ext4_has_metadata_csum(dir->i_sb))
616 entry_space -= sizeof(struct dx_tail);
617 return entry_space / sizeof(struct dx_entry);
618 }
619
620 static inline unsigned dx_node_limit(struct inode *dir)
621 {
622 unsigned int entry_space = dir->i_sb->s_blocksize -
623 ext4_dir_rec_len(0, dir);
624
625 if (ext4_has_metadata_csum(dir->i_sb))
626 entry_space -= sizeof(struct dx_tail);
627 return entry_space / sizeof(struct dx_entry);
628 }
629
630 /*
631 * Debug
632 */
633 #ifdef DX_DEBUG
634 static void dx_show_index(char * label, struct dx_entry *entries)
635 {
636 int i, n = dx_get_count (entries);
637 printk(KERN_DEBUG "%s index", label);
638 for (i = 0; i < n; i++) {
639 printk(KERN_CONT " %x->%lu",
640 i ? dx_get_hash(entries + i) : 0,
641 (unsigned long)dx_get_block(entries + i));
642 }
643 printk(KERN_CONT "\n");
644 }
645
646 struct stats
647 {
648 unsigned names;
649 unsigned space;
650 unsigned bcount;
651 };
652
653 static struct stats dx_show_leaf(struct inode *dir,
654 struct dx_hash_info *hinfo,
655 struct ext4_dir_entry_2 *de,
656 int size, int show_names)
657 {
658 unsigned names = 0, space = 0;
659 char *base = (char *) de;
660 struct dx_hash_info h = *hinfo;
661
662 printk("names: ");
663 while ((char *) de < base + size)
664 {
665 if (de->inode)
666 {
667 if (show_names)
668 {
669 #ifdef CONFIG_FS_ENCRYPTION
670 int len;
671 char *name;
672 struct fscrypt_str fname_crypto_str =
673 FSTR_INIT(NULL, 0);
674 int res = 0;
675
676 name = de->name;
677 len = de->name_len;
678 if (!IS_ENCRYPTED(dir)) {
679 /* Directory is not encrypted */
680 (void) ext4fs_dirhash(dir, de->name,
681 de->name_len, &h);
682 printk("%*.s:(U)%x.%u ", len,
683 name, h.hash,
684 (unsigned) ((char *) de
685 - base));
686 } else {
687 struct fscrypt_str de_name =
688 FSTR_INIT(name, len);
689
690 /* Directory is encrypted */
691 res = fscrypt_fname_alloc_buffer(
692 len, &fname_crypto_str);
693 if (res)
694 printk(KERN_WARNING "Error "
695 "allocating crypto "
696 "buffer--skipping "
697 "crypto\n");
698 res = fscrypt_fname_disk_to_usr(dir,
699 0, 0, &de_name,
700 &fname_crypto_str);
701 if (res) {
702 printk(KERN_WARNING "Error "
703 "converting filename "
704 "from disk to usr"
705 "\n");
706 name = "??";
707 len = 2;
708 } else {
709 name = fname_crypto_str.name;
710 len = fname_crypto_str.len;
711 }
712 if (IS_CASEFOLDED(dir))
713 h.hash = EXT4_DIRENT_HASH(de);
714 else
715 (void) ext4fs_dirhash(dir,
716 de->name,
717 de->name_len, &h);
718 printk("%*.s:(E)%x.%u ", len, name,
719 h.hash, (unsigned) ((char *) de
720 - base));
721 fscrypt_fname_free_buffer(
722 &fname_crypto_str);
723 }
724 #else
725 int len = de->name_len;
726 char *name = de->name;
727 (void) ext4fs_dirhash(dir, de->name,
728 de->name_len, &h);
729 printk("%*.s:%x.%u ", len, name, h.hash,
730 (unsigned) ((char *) de - base));
731 #endif
732 }
733 space += ext4_dir_rec_len(de->name_len, dir);
734 names++;
735 }
736 de = ext4_next_entry(de, size);
737 }
738 printk(KERN_CONT "(%i)\n", names);
739 return (struct stats) { names, space, 1 };
740 }
741
742 struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
743 struct dx_entry *entries, int levels)
744 {
745 unsigned blocksize = dir->i_sb->s_blocksize;
746 unsigned count = dx_get_count(entries), names = 0, space = 0, i;
747 unsigned bcount = 0;
748 struct buffer_head *bh;
749 printk("%i indexed blocks...\n", count);
750 for (i = 0; i < count; i++, entries++)
751 {
752 ext4_lblk_t block = dx_get_block(entries);
753 ext4_lblk_t hash = i ? dx_get_hash(entries): 0;
754 u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
755 struct stats stats;
756 printk("%s%3u:%03u hash %8x/%8x ",levels?"":" ", i, block, hash, range);
757 bh = ext4_bread(NULL,dir, block, 0);
758 if (!bh || IS_ERR(bh))
759 continue;
760 stats = levels?
761 dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
762 dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *)
763 bh->b_data, blocksize, 0);
764 names += stats.names;
765 space += stats.space;
766 bcount += stats.bcount;
767 brelse(bh);
768 }
769 if (bcount)
770 printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n",
771 levels ? "" : " ", names, space/bcount,
772 (space/bcount)*100/blocksize);
773 return (struct stats) { names, space, bcount};
774 }
775
776 /*
777 * Linear search cross check
778 */
779 static inline void htree_rep_invariant_check(struct dx_entry *at,
780 struct dx_entry *target,
781 u32 hash, unsigned int n)
782 {
783 while (n--) {
784 dxtrace(printk(KERN_CONT ","));
785 if (dx_get_hash(++at) > hash) {
786 at--;
787 break;
788 }
789 }
790 ASSERT(at == target - 1);
791 }
792 #else /* DX_DEBUG */
793 static inline void htree_rep_invariant_check(struct dx_entry *at,
794 struct dx_entry *target,
795 u32 hash, unsigned int n)
796 {
797 }
798 #endif /* DX_DEBUG */
799
800 /*
801 * Probe for a directory leaf block to search.
802 *
803 * dx_probe can return ERR_BAD_DX_DIR, which means there was a format
804 * error in the directory index, and the caller should fall back to
805 * searching the directory normally. The callers of dx_probe **MUST**
806 * check for this error code, and make sure it never gets reflected
807 * back to userspace.
808 */
809 static struct dx_frame *
810 dx_probe(struct ext4_filename *fname, struct inode *dir,
811 struct dx_hash_info *hinfo, struct dx_frame *frame_in)
812 {
813 unsigned count, indirect, level, i;
814 struct dx_entry *at, *entries, *p, *q, *m;
815 struct dx_root *root;
816 struct dx_frame *frame = frame_in;
817 struct dx_frame *ret_err = ERR_PTR(ERR_BAD_DX_DIR);
818 u32 hash;
819 ext4_lblk_t block;
820 ext4_lblk_t blocks[EXT4_HTREE_LEVEL];
821
822 memset(frame_in, 0, EXT4_HTREE_LEVEL * sizeof(frame_in[0]));
823 frame->bh = ext4_read_dirblock(dir, 0, INDEX);
824 if (IS_ERR(frame->bh))
825 return (struct dx_frame *) frame->bh;
826
827 root = (struct dx_root *) frame->bh->b_data;
828 if (root->info.hash_version != DX_HASH_TEA &&
829 root->info.hash_version != DX_HASH_HALF_MD4 &&
830 root->info.hash_version != DX_HASH_LEGACY &&
831 root->info.hash_version != DX_HASH_SIPHASH) {
832 ext4_warning_inode(dir, "Unrecognised inode hash code %u",
833 root->info.hash_version);
834 goto fail;
835 }
836 if (ext4_hash_in_dirent(dir)) {
837 if (root->info.hash_version != DX_HASH_SIPHASH) {
838 ext4_warning_inode(dir,
839 "Hash in dirent, but hash is not SIPHASH");
840 goto fail;
841 }
842 } else {
843 if (root->info.hash_version == DX_HASH_SIPHASH) {
844 ext4_warning_inode(dir,
845 "Hash code is SIPHASH, but hash not in dirent");
846 goto fail;
847 }
848 }
849 if (fname)
850 hinfo = &fname->hinfo;
851 hinfo->hash_version = root->info.hash_version;
852 if (hinfo->hash_version <= DX_HASH_TEA)
853 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
854 hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
855 /* hash is already computed for encrypted casefolded directory */
856 if (fname && fname_name(fname) &&
857 !(IS_ENCRYPTED(dir) && IS_CASEFOLDED(dir))) {
858 int ret = ext4fs_dirhash(dir, fname_name(fname),
859 fname_len(fname), hinfo);
860 if (ret < 0) {
861 ret_err = ERR_PTR(ret);
862 goto fail;
863 }
864 }
865 hash = hinfo->hash;
866
867 if (root->info.unused_flags & 1) {
868 ext4_warning_inode(dir, "Unimplemented hash flags: %#06x",
869 root->info.unused_flags);
870 goto fail;
871 }
872
873 indirect = root->info.indirect_levels;
874 if (indirect >= ext4_dir_htree_level(dir->i_sb)) {
875 ext4_warning(dir->i_sb,
876 "Directory (ino: %lu) htree depth %#06x exceed"
877 "supported value", dir->i_ino,
878 ext4_dir_htree_level(dir->i_sb));
879 if (ext4_dir_htree_level(dir->i_sb) < EXT4_HTREE_LEVEL) {
880 ext4_warning(dir->i_sb, "Enable large directory "
881 "feature to access it");
882 }
883 goto fail;
884 }
885
886 entries = (struct dx_entry *)(((char *)&root->info) +
887 root->info.info_length);
888
889 if (dx_get_limit(entries) != dx_root_limit(dir,
890 root->info.info_length)) {
891 ext4_warning_inode(dir, "dx entry: limit %u != root limit %u",
892 dx_get_limit(entries),
893 dx_root_limit(dir, root->info.info_length));
894 goto fail;
895 }
896
897 dxtrace(printk("Look up %x", hash));
898 level = 0;
899 blocks[0] = 0;
900 while (1) {
901 count = dx_get_count(entries);
902 if (!count || count > dx_get_limit(entries)) {
903 ext4_warning_inode(dir,
904 "dx entry: count %u beyond limit %u",
905 count, dx_get_limit(entries));
906 goto fail;
907 }
908
909 p = entries + 1;
910 q = entries + count - 1;
911 while (p <= q) {
912 m = p + (q - p) / 2;
913 dxtrace(printk(KERN_CONT "."));
914 if (dx_get_hash(m) > hash)
915 q = m - 1;
916 else
917 p = m + 1;
918 }
919
920 htree_rep_invariant_check(entries, p, hash, count - 1);
921
922 at = p - 1;
923 dxtrace(printk(KERN_CONT " %x->%u\n",
924 at == entries ? 0 : dx_get_hash(at),
925 dx_get_block(at)));
926 frame->entries = entries;
927 frame->at = at;
928
929 block = dx_get_block(at);
930 for (i = 0; i <= level; i++) {
931 if (blocks[i] == block) {
932 ext4_warning_inode(dir,
933 "dx entry: tree cycle block %u points back to block %u",
934 blocks[level], block);
935 goto fail;
936 }
937 }
938 if (++level > indirect)
939 return frame;
940 blocks[level] = block;
941 frame++;
942 frame->bh = ext4_read_dirblock(dir, block, INDEX);
943 if (IS_ERR(frame->bh)) {
944 ret_err = (struct dx_frame *) frame->bh;
945 frame->bh = NULL;
946 goto fail;
947 }
948
949 entries = ((struct dx_node *) frame->bh->b_data)->entries;
950
951 if (dx_get_limit(entries) != dx_node_limit(dir)) {
952 ext4_warning_inode(dir,
953 "dx entry: limit %u != node limit %u",
954 dx_get_limit(entries), dx_node_limit(dir));
955 goto fail;
956 }
957 }
958 fail:
959 while (frame >= frame_in) {
960 brelse(frame->bh);
961 frame--;
962 }
963
964 if (ret_err == ERR_PTR(ERR_BAD_DX_DIR))
965 ext4_warning_inode(dir,
966 "Corrupt directory, running e2fsck is recommended");
967 return ret_err;
968 }
969
970 static void dx_release(struct dx_frame *frames)
971 {
972 struct dx_root_info *info;
973 int i;
974 unsigned int indirect_levels;
975
976 if (frames[0].bh == NULL)
977 return;
978
979 info = &((struct dx_root *)frames[0].bh->b_data)->info;
980 /* save local copy, "info" may be freed after brelse() */
981 indirect_levels = info->indirect_levels;
982 for (i = 0; i <= indirect_levels; i++) {
983 if (frames[i].bh == NULL)
984 break;
985 brelse(frames[i].bh);
986 frames[i].bh = NULL;
987 }
988 }
989
990 /*
991 * This function increments the frame pointer to search the next leaf
992 * block, and reads in the necessary intervening nodes if the search
993 * should be necessary. Whether or not the search is necessary is
994 * controlled by the hash parameter. If the hash value is even, then
995 * the search is only continued if the next block starts with that
996 * hash value. This is used if we are searching for a specific file.
997 *
998 * If the hash value is HASH_NB_ALWAYS, then always go to the next block.
999 *
1000 * This function returns 1 if the caller should continue to search,
1001 * or 0 if it should not. If there is an error reading one of the
1002 * index blocks, it will a negative error code.
1003 *
1004 * If start_hash is non-null, it will be filled in with the starting
1005 * hash of the next page.
1006 */
1007 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
1008 struct dx_frame *frame,
1009 struct dx_frame *frames,
1010 __u32 *start_hash)
1011 {
1012 struct dx_frame *p;
1013 struct buffer_head *bh;
1014 int num_frames = 0;
1015 __u32 bhash;
1016
1017 p = frame;
1018 /*
1019 * Find the next leaf page by incrementing the frame pointer.
1020 * If we run out of entries in the interior node, loop around and
1021 * increment pointer in the parent node. When we break out of
1022 * this loop, num_frames indicates the number of interior
1023 * nodes need to be read.
1024 */
1025 while (1) {
1026 if (++(p->at) < p->entries + dx_get_count(p->entries))
1027 break;
1028 if (p == frames)
1029 return 0;
1030 num_frames++;
1031 p--;
1032 }
1033
1034 /*
1035 * If the hash is 1, then continue only if the next page has a
1036 * continuation hash of any value. This is used for readdir
1037 * handling. Otherwise, check to see if the hash matches the
1038 * desired continuation hash. If it doesn't, return since
1039 * there's no point to read in the successive index pages.
1040 */
1041 bhash = dx_get_hash(p->at);
1042 if (start_hash)
1043 *start_hash = bhash;
1044 if ((hash & 1) == 0) {
1045 if ((bhash & ~1) != hash)
1046 return 0;
1047 }
1048 /*
1049 * If the hash is HASH_NB_ALWAYS, we always go to the next
1050 * block so no check is necessary
1051 */
1052 while (num_frames--) {
1053 bh = ext4_read_dirblock(dir, dx_get_block(p->at), INDEX);
1054 if (IS_ERR(bh))
1055 return PTR_ERR(bh);
1056 p++;
1057 brelse(p->bh);
1058 p->bh = bh;
1059 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
1060 }
1061 return 1;
1062 }
1063
1064
1065 /*
1066 * This function fills a red-black tree with information from a
1067 * directory block. It returns the number directory entries loaded
1068 * into the tree. If there is an error it is returned in err.
1069 */
1070 static int htree_dirblock_to_tree(struct file *dir_file,
1071 struct inode *dir, ext4_lblk_t block,
1072 struct dx_hash_info *hinfo,
1073 __u32 start_hash, __u32 start_minor_hash)
1074 {
1075 struct buffer_head *bh;
1076 struct ext4_dir_entry_2 *de, *top;
1077 int err = 0, count = 0;
1078 struct fscrypt_str fname_crypto_str = FSTR_INIT(NULL, 0), tmp_str;
1079 int csum = ext4_has_metadata_csum(dir->i_sb);
1080
1081 dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
1082 (unsigned long)block));
1083 bh = ext4_read_dirblock(dir, block, DIRENT_HTREE);
1084 if (IS_ERR(bh))
1085 return PTR_ERR(bh);
1086
1087 de = (struct ext4_dir_entry_2 *) bh->b_data;
1088 /* csum entries are not larger in the casefolded encrypted case */
1089 top = (struct ext4_dir_entry_2 *) ((char *) de +
1090 dir->i_sb->s_blocksize -
1091 ext4_dir_rec_len(0,
1092 csum ? NULL : dir));
1093 /* Check if the directory is encrypted */
1094 if (IS_ENCRYPTED(dir)) {
1095 err = fscrypt_prepare_readdir(dir);
1096 if (err < 0) {
1097 brelse(bh);
1098 return err;
1099 }
1100 err = fscrypt_fname_alloc_buffer(EXT4_NAME_LEN,
1101 &fname_crypto_str);
1102 if (err < 0) {
1103 brelse(bh);
1104 return err;
1105 }
1106 }
1107
1108 for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) {
1109 if (ext4_check_dir_entry(dir, NULL, de, bh,
1110 bh->b_data, bh->b_size,
1111 (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
1112 + ((char *)de - bh->b_data))) {
1113 /* silently ignore the rest of the block */
1114 break;
1115 }
1116 if (ext4_hash_in_dirent(dir)) {
1117 if (de->name_len && de->inode) {
1118 hinfo->hash = EXT4_DIRENT_HASH(de);
1119 hinfo->minor_hash = EXT4_DIRENT_MINOR_HASH(de);
1120 } else {
1121 hinfo->hash = 0;
1122 hinfo->minor_hash = 0;
1123 }
1124 } else {
1125 err = ext4fs_dirhash(dir, de->name,
1126 de->name_len, hinfo);
1127 if (err < 0) {
1128 count = err;
1129 goto errout;
1130 }
1131 }
1132 if ((hinfo->hash < start_hash) ||
1133 ((hinfo->hash == start_hash) &&
1134 (hinfo->minor_hash < start_minor_hash)))
1135 continue;
1136 if (de->inode == 0)
1137 continue;
1138 if (!IS_ENCRYPTED(dir)) {
1139 tmp_str.name = de->name;
1140 tmp_str.len = de->name_len;
1141 err = ext4_htree_store_dirent(dir_file,
1142 hinfo->hash, hinfo->minor_hash, de,
1143 &tmp_str);
1144 } else {
1145 int save_len = fname_crypto_str.len;
1146 struct fscrypt_str de_name = FSTR_INIT(de->name,
1147 de->name_len);
1148
1149 /* Directory is encrypted */
1150 err = fscrypt_fname_disk_to_usr(dir, hinfo->hash,
1151 hinfo->minor_hash, &de_name,
1152 &fname_crypto_str);
1153 if (err) {
1154 count = err;
1155 goto errout;
1156 }
1157 err = ext4_htree_store_dirent(dir_file,
1158 hinfo->hash, hinfo->minor_hash, de,
1159 &fname_crypto_str);
1160 fname_crypto_str.len = save_len;
1161 }
1162 if (err != 0) {
1163 count = err;
1164 goto errout;
1165 }
1166 count++;
1167 }
1168 errout:
1169 brelse(bh);
1170 fscrypt_fname_free_buffer(&fname_crypto_str);
1171 return count;
1172 }
1173
1174
1175 /*
1176 * This function fills a red-black tree with information from a
1177 * directory. We start scanning the directory in hash order, starting
1178 * at start_hash and start_minor_hash.
1179 *
1180 * This function returns the number of entries inserted into the tree,
1181 * or a negative error code.
1182 */
1183 int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
1184 __u32 start_minor_hash, __u32 *next_hash)
1185 {
1186 struct dx_hash_info hinfo;
1187 struct ext4_dir_entry_2 *de;
1188 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
1189 struct inode *dir;
1190 ext4_lblk_t block;
1191 int count = 0;
1192 int ret, err;
1193 __u32 hashval;
1194 struct fscrypt_str tmp_str;
1195
1196 dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
1197 start_hash, start_minor_hash));
1198 dir = file_inode(dir_file);
1199 if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) {
1200 if (ext4_hash_in_dirent(dir))
1201 hinfo.hash_version = DX_HASH_SIPHASH;
1202 else
1203 hinfo.hash_version =
1204 EXT4_SB(dir->i_sb)->s_def_hash_version;
1205 if (hinfo.hash_version <= DX_HASH_TEA)
1206 hinfo.hash_version +=
1207 EXT4_SB(dir->i_sb)->s_hash_unsigned;
1208 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
1209 if (ext4_has_inline_data(dir)) {
1210 int has_inline_data = 1;
1211 count = ext4_inlinedir_to_tree(dir_file, dir, 0,
1212 &hinfo, start_hash,
1213 start_minor_hash,
1214 &has_inline_data);
1215 if (has_inline_data) {
1216 *next_hash = ~0;
1217 return count;
1218 }
1219 }
1220 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
1221 start_hash, start_minor_hash);
1222 *next_hash = ~0;
1223 return count;
1224 }
1225 hinfo.hash = start_hash;
1226 hinfo.minor_hash = 0;
1227 frame = dx_probe(NULL, dir, &hinfo, frames);
1228 if (IS_ERR(frame))
1229 return PTR_ERR(frame);
1230
1231 /* Add '.' and '..' from the htree header */
1232 if (!start_hash && !start_minor_hash) {
1233 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
1234 tmp_str.name = de->name;
1235 tmp_str.len = de->name_len;
1236 err = ext4_htree_store_dirent(dir_file, 0, 0,
1237 de, &tmp_str);
1238 if (err != 0)
1239 goto errout;
1240 count++;
1241 }
1242 if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
1243 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
1244 de = ext4_next_entry(de, dir->i_sb->s_blocksize);
1245 tmp_str.name = de->name;
1246 tmp_str.len = de->name_len;
1247 err = ext4_htree_store_dirent(dir_file, 2, 0,
1248 de, &tmp_str);
1249 if (err != 0)
1250 goto errout;
1251 count++;
1252 }
1253
1254 while (1) {
1255 if (fatal_signal_pending(current)) {
1256 err = -ERESTARTSYS;
1257 goto errout;
1258 }
1259 cond_resched();
1260 block = dx_get_block(frame->at);
1261 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
1262 start_hash, start_minor_hash);
1263 if (ret < 0) {
1264 err = ret;
1265 goto errout;
1266 }
1267 count += ret;
1268 hashval = ~0;
1269 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
1270 frame, frames, &hashval);
1271 *next_hash = hashval;
1272 if (ret < 0) {
1273 err = ret;
1274 goto errout;
1275 }
1276 /*
1277 * Stop if: (a) there are no more entries, or
1278 * (b) we have inserted at least one entry and the
1279 * next hash value is not a continuation
1280 */
1281 if ((ret == 0) ||
1282 (count && ((hashval & 1) == 0)))
1283 break;
1284 }
1285 dx_release(frames);
1286 dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, "
1287 "next hash: %x\n", count, *next_hash));
1288 return count;
1289 errout:
1290 dx_release(frames);
1291 return (err);
1292 }
1293
1294 static inline int search_dirblock(struct buffer_head *bh,
1295 struct inode *dir,
1296 struct ext4_filename *fname,
1297 unsigned int offset,
1298 struct ext4_dir_entry_2 **res_dir)
1299 {
1300 return ext4_search_dir(bh, bh->b_data, dir->i_sb->s_blocksize, dir,
1301 fname, offset, res_dir);
1302 }
1303
1304 /*
1305 * Directory block splitting, compacting
1306 */
1307
1308 /*
1309 * Create map of hash values, offsets, and sizes, stored at end of block.
1310 * Returns number of entries mapped.
1311 */
1312 static int dx_make_map(struct inode *dir, struct buffer_head *bh,
1313 struct dx_hash_info *hinfo,
1314 struct dx_map_entry *map_tail)
1315 {
1316 int count = 0;
1317 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)bh->b_data;
1318 unsigned int buflen = bh->b_size;
1319 char *base = bh->b_data;
1320 struct dx_hash_info h = *hinfo;
1321 int blocksize = EXT4_BLOCK_SIZE(dir->i_sb);
1322
1323 if (ext4_has_metadata_csum(dir->i_sb))
1324 buflen -= sizeof(struct ext4_dir_entry_tail);
1325
1326 while ((char *) de < base + buflen) {
1327 if (ext4_check_dir_entry(dir, NULL, de, bh, base, buflen,
1328 ((char *)de) - base))
1329 return -EFSCORRUPTED;
1330 if (de->name_len && de->inode) {
1331 if (ext4_hash_in_dirent(dir))
1332 h.hash = EXT4_DIRENT_HASH(de);
1333 else {
1334 int err = ext4fs_dirhash(dir, de->name,
1335 de->name_len, &h);
1336 if (err < 0)
1337 return err;
1338 }
1339 map_tail--;
1340 map_tail->hash = h.hash;
1341 map_tail->offs = ((char *) de - base)>>2;
1342 map_tail->size = ext4_rec_len_from_disk(de->rec_len,
1343 blocksize);
1344 count++;
1345 cond_resched();
1346 }
1347 de = ext4_next_entry(de, blocksize);
1348 }
1349 return count;
1350 }
1351
1352 /* Sort map by hash value */
1353 static void dx_sort_map (struct dx_map_entry *map, unsigned count)
1354 {
1355 struct dx_map_entry *p, *q, *top = map + count - 1;
1356 int more;
1357 /* Combsort until bubble sort doesn't suck */
1358 while (count > 2) {
1359 count = count*10/13;
1360 if (count - 9 < 2) /* 9, 10 -> 11 */
1361 count = 11;
1362 for (p = top, q = p - count; q >= map; p--, q--)
1363 if (p->hash < q->hash)
1364 swap(*p, *q);
1365 }
1366 /* Garden variety bubble sort */
1367 do {
1368 more = 0;
1369 q = top;
1370 while (q-- > map) {
1371 if (q[1].hash >= q[0].hash)
1372 continue;
1373 swap(*(q+1), *q);
1374 more = 1;
1375 }
1376 } while(more);
1377 }
1378
1379 static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
1380 {
1381 struct dx_entry *entries = frame->entries;
1382 struct dx_entry *old = frame->at, *new = old + 1;
1383 int count = dx_get_count(entries);
1384
1385 ASSERT(count < dx_get_limit(entries));
1386 ASSERT(old < entries + count);
1387 memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
1388 dx_set_hash(new, hash);
1389 dx_set_block(new, block);
1390 dx_set_count(entries, count + 1);
1391 }
1392
1393 #if IS_ENABLED(CONFIG_UNICODE)
1394 int ext4_fname_setup_ci_filename(struct inode *dir, const struct qstr *iname,
1395 struct ext4_filename *name)
1396 {
1397 struct qstr *cf_name = &name->cf_name;
1398 unsigned char *buf;
1399 struct dx_hash_info *hinfo = &name->hinfo;
1400 int len;
1401
1402 if (!IS_CASEFOLDED(dir) ||
1403 (IS_ENCRYPTED(dir) && !fscrypt_has_encryption_key(dir))) {
1404 cf_name->name = NULL;
1405 return 0;
1406 }
1407
1408 buf = kmalloc(EXT4_NAME_LEN, GFP_NOFS);
1409 if (!buf)
1410 return -ENOMEM;
1411
1412 len = utf8_casefold(dir->i_sb->s_encoding, iname, buf, EXT4_NAME_LEN);
1413 if (len <= 0) {
1414 kfree(buf);
1415 buf = NULL;
1416 }
1417 cf_name->name = buf;
1418 cf_name->len = (unsigned) len;
1419
1420 if (!IS_ENCRYPTED(dir))
1421 return 0;
1422
1423 hinfo->hash_version = DX_HASH_SIPHASH;
1424 hinfo->seed = NULL;
1425 if (cf_name->name)
1426 return ext4fs_dirhash(dir, cf_name->name, cf_name->len, hinfo);
1427 else
1428 return ext4fs_dirhash(dir, iname->name, iname->len, hinfo);
1429 }
1430 #endif
1431
1432 /*
1433 * Test whether a directory entry matches the filename being searched for.
1434 *
1435 * Return: %true if the directory entry matches, otherwise %false.
1436 */
1437 static bool ext4_match(struct inode *parent,
1438 const struct ext4_filename *fname,
1439 struct ext4_dir_entry_2 *de)
1440 {
1441 struct fscrypt_name f;
1442
1443 if (!de->inode)
1444 return false;
1445
1446 f.usr_fname = fname->usr_fname;
1447 f.disk_name = fname->disk_name;
1448 #ifdef CONFIG_FS_ENCRYPTION
1449 f.crypto_buf = fname->crypto_buf;
1450 #endif
1451
1452 #if IS_ENABLED(CONFIG_UNICODE)
1453 if (IS_CASEFOLDED(parent) &&
1454 (!IS_ENCRYPTED(parent) || fscrypt_has_encryption_key(parent))) {
1455 /*
1456 * Just checking IS_ENCRYPTED(parent) below is not
1457 * sufficient to decide whether one can use the hash for
1458 * skipping the string comparison, because the key might
1459 * have been added right after
1460 * ext4_fname_setup_ci_filename(). In this case, a hash
1461 * mismatch will be a false negative. Therefore, make
1462 * sure cf_name was properly initialized before
1463 * considering the calculated hash.
1464 */
1465 if (IS_ENCRYPTED(parent) && fname->cf_name.name &&
1466 (fname->hinfo.hash != EXT4_DIRENT_HASH(de) ||
1467 fname->hinfo.minor_hash != EXT4_DIRENT_MINOR_HASH(de)))
1468 return false;
1469 /*
1470 * Treat comparison errors as not a match. The
1471 * only case where it happens is on a disk
1472 * corruption or ENOMEM.
1473 */
1474
1475 return generic_ci_match(parent, fname->usr_fname,
1476 &fname->cf_name, de->name,
1477 de->name_len) > 0;
1478 }
1479 #endif
1480
1481 return fscrypt_match_name(&f, de->name, de->name_len);
1482 }
1483
1484 /*
1485 * Returns 0 if not found, -EFSCORRUPTED on failure, and 1 on success
1486 */
1487 int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size,
1488 struct inode *dir, struct ext4_filename *fname,
1489 unsigned int offset, struct ext4_dir_entry_2 **res_dir)
1490 {
1491 struct ext4_dir_entry_2 * de;
1492 char * dlimit;
1493 int de_len;
1494
1495 de = (struct ext4_dir_entry_2 *)search_buf;
1496 dlimit = search_buf + buf_size;
1497 while ((char *) de < dlimit - EXT4_BASE_DIR_LEN) {
1498 /* this code is executed quadratically often */
1499 /* do minimal checking `by hand' */
1500 if (de->name + de->name_len <= dlimit &&
1501 ext4_match(dir, fname, de)) {
1502 /* found a match - just to be sure, do
1503 * a full check */
1504 if (ext4_check_dir_entry(dir, NULL, de, bh, search_buf,
1505 buf_size, offset))
1506 return -EFSCORRUPTED;
1507 *res_dir = de;
1508 return 1;
1509 }
1510 /* prevent looping on a bad block */
1511 de_len = ext4_rec_len_from_disk(de->rec_len,
1512 dir->i_sb->s_blocksize);
1513 if (de_len <= 0)
1514 return -EFSCORRUPTED;
1515 offset += de_len;
1516 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
1517 }
1518 return 0;
1519 }
1520
1521 static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block,
1522 struct ext4_dir_entry *de)
1523 {
1524 struct super_block *sb = dir->i_sb;
1525
1526 if (!is_dx(dir))
1527 return 0;
1528 if (block == 0)
1529 return 1;
1530 if (de->inode == 0 &&
1531 ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) ==
1532 sb->s_blocksize)
1533 return 1;
1534 return 0;
1535 }
1536
1537 /*
1538 * __ext4_find_entry()
1539 *
1540 * finds an entry in the specified directory with the wanted name. It
1541 * returns the cache buffer in which the entry was found, and the entry
1542 * itself (as a parameter - res_dir). It does NOT read the inode of the
1543 * entry - you'll have to do that yourself if you want to.
1544 *
1545 * The returned buffer_head has ->b_count elevated. The caller is expected
1546 * to brelse() it when appropriate.
1547 */
1548 static struct buffer_head *__ext4_find_entry(struct inode *dir,
1549 struct ext4_filename *fname,
1550 struct ext4_dir_entry_2 **res_dir,
1551 int *inlined)
1552 {
1553 struct super_block *sb;
1554 struct buffer_head *bh_use[NAMEI_RA_SIZE];
1555 struct buffer_head *bh, *ret = NULL;
1556 ext4_lblk_t start, block;
1557 const u8 *name = fname->usr_fname->name;
1558 size_t ra_max = 0; /* Number of bh's in the readahead
1559 buffer, bh_use[] */
1560 size_t ra_ptr = 0; /* Current index into readahead
1561 buffer */
1562 ext4_lblk_t nblocks;
1563 int i, namelen, retval;
1564
1565 *res_dir = NULL;
1566 sb = dir->i_sb;
1567 namelen = fname->usr_fname->len;
1568 if (namelen > EXT4_NAME_LEN)
1569 return NULL;
1570
1571 if (ext4_has_inline_data(dir)) {
1572 int has_inline_data = 1;
1573 ret = ext4_find_inline_entry(dir, fname, res_dir,
1574 &has_inline_data);
1575 if (inlined)
1576 *inlined = has_inline_data;
1577 if (has_inline_data)
1578 goto cleanup_and_exit;
1579 }
1580
1581 if ((namelen <= 2) && (name[0] == '.') &&
1582 (name[1] == '.' || name[1] == '\0')) {
1583 /*
1584 * "." or ".." will only be in the first block
1585 * NFS may look up ".."; "." should be handled by the VFS
1586 */
1587 block = start = 0;
1588 nblocks = 1;
1589 goto restart;
1590 }
1591 if (is_dx(dir)) {
1592 ret = ext4_dx_find_entry(dir, fname, res_dir);
1593 /*
1594 * On success, or if the error was file not found,
1595 * return. Otherwise, fall back to doing a search the
1596 * old fashioned way.
1597 */
1598 if (!IS_ERR(ret) || PTR_ERR(ret) != ERR_BAD_DX_DIR)
1599 goto cleanup_and_exit;
1600 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
1601 "falling back\n"));
1602 ret = NULL;
1603 }
1604 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1605 if (!nblocks) {
1606 ret = NULL;
1607 goto cleanup_and_exit;
1608 }
1609 start = EXT4_I(dir)->i_dir_start_lookup;
1610 if (start >= nblocks)
1611 start = 0;
1612 block = start;
1613 restart:
1614 do {
1615 /*
1616 * We deal with the read-ahead logic here.
1617 */
1618 cond_resched();
1619 if (ra_ptr >= ra_max) {
1620 /* Refill the readahead buffer */
1621 ra_ptr = 0;
1622 if (block < start)
1623 ra_max = start - block;
1624 else
1625 ra_max = nblocks - block;
1626 ra_max = min(ra_max, ARRAY_SIZE(bh_use));
1627 retval = ext4_bread_batch(dir, block, ra_max,
1628 false /* wait */, bh_use);
1629 if (retval) {
1630 ret = ERR_PTR(retval);
1631 ra_max = 0;
1632 goto cleanup_and_exit;
1633 }
1634 }
1635 if ((bh = bh_use[ra_ptr++]) == NULL)
1636 goto next;
1637 wait_on_buffer(bh);
1638 if (!buffer_uptodate(bh)) {
1639 EXT4_ERROR_INODE_ERR(dir, EIO,
1640 "reading directory lblock %lu",
1641 (unsigned long) block);
1642 brelse(bh);
1643 ret = ERR_PTR(-EIO);
1644 goto cleanup_and_exit;
1645 }
1646 if (!buffer_verified(bh) &&
1647 !is_dx_internal_node(dir, block,
1648 (struct ext4_dir_entry *)bh->b_data) &&
1649 !ext4_dirblock_csum_verify(dir, bh)) {
1650 EXT4_ERROR_INODE_ERR(dir, EFSBADCRC,
1651 "checksumming directory "
1652 "block %lu", (unsigned long)block);
1653 brelse(bh);
1654 ret = ERR_PTR(-EFSBADCRC);
1655 goto cleanup_and_exit;
1656 }
1657 set_buffer_verified(bh);
1658 i = search_dirblock(bh, dir, fname,
1659 block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
1660 if (i == 1) {
1661 EXT4_I(dir)->i_dir_start_lookup = block;
1662 ret = bh;
1663 goto cleanup_and_exit;
1664 } else {
1665 brelse(bh);
1666 if (i < 0) {
1667 ret = ERR_PTR(i);
1668 goto cleanup_and_exit;
1669 }
1670 }
1671 next:
1672 if (++block >= nblocks)
1673 block = 0;
1674 } while (block != start);
1675
1676 /*
1677 * If the directory has grown while we were searching, then
1678 * search the last part of the directory before giving up.
1679 */
1680 block = nblocks;
1681 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1682 if (block < nblocks) {
1683 start = 0;
1684 goto restart;
1685 }
1686
1687 cleanup_and_exit:
1688 /* Clean up the read-ahead blocks */
1689 for (; ra_ptr < ra_max; ra_ptr++)
1690 brelse(bh_use[ra_ptr]);
1691 return ret;
1692 }
1693
1694 static struct buffer_head *ext4_find_entry(struct inode *dir,
1695 const struct qstr *d_name,
1696 struct ext4_dir_entry_2 **res_dir,
1697 int *inlined)
1698 {
1699 int err;
1700 struct ext4_filename fname;
1701 struct buffer_head *bh;
1702
1703 err = ext4_fname_setup_filename(dir, d_name, 1, &fname);
1704 if (err == -ENOENT)
1705 return NULL;
1706 if (err)
1707 return ERR_PTR(err);
1708
1709 bh = __ext4_find_entry(dir, &fname, res_dir, inlined);
1710
1711 ext4_fname_free_filename(&fname);
1712 return bh;
1713 }
1714
1715 static struct buffer_head *ext4_lookup_entry(struct inode *dir,
1716 struct dentry *dentry,
1717 struct ext4_dir_entry_2 **res_dir)
1718 {
1719 int err;
1720 struct ext4_filename fname;
1721 struct buffer_head *bh;
1722
1723 err = ext4_fname_prepare_lookup(dir, dentry, &fname);
1724 if (err == -ENOENT)
1725 return NULL;
1726 if (err)
1727 return ERR_PTR(err);
1728
1729 bh = __ext4_find_entry(dir, &fname, res_dir, NULL);
1730
1731 ext4_fname_free_filename(&fname);
1732 return bh;
1733 }
1734
1735 static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
1736 struct ext4_filename *fname,
1737 struct ext4_dir_entry_2 **res_dir)
1738 {
1739 struct super_block * sb = dir->i_sb;
1740 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
1741 struct buffer_head *bh;
1742 ext4_lblk_t block;
1743 int retval;
1744
1745 #ifdef CONFIG_FS_ENCRYPTION
1746 *res_dir = NULL;
1747 #endif
1748 frame = dx_probe(fname, dir, NULL, frames);
1749 if (IS_ERR(frame))
1750 return (struct buffer_head *) frame;
1751 do {
1752 block = dx_get_block(frame->at);
1753 bh = ext4_read_dirblock(dir, block, DIRENT_HTREE);
1754 if (IS_ERR(bh))
1755 goto errout;
1756
1757 retval = search_dirblock(bh, dir, fname,
1758 block << EXT4_BLOCK_SIZE_BITS(sb),
1759 res_dir);
1760 if (retval == 1)
1761 goto success;
1762 brelse(bh);
1763 if (retval < 0) {
1764 bh = ERR_PTR(ERR_BAD_DX_DIR);
1765 goto errout;
1766 }
1767
1768 /* Check to see if we should continue to search */
1769 retval = ext4_htree_next_block(dir, fname->hinfo.hash, frame,
1770 frames, NULL);
1771 if (retval < 0) {
1772 ext4_warning_inode(dir,
1773 "error %d reading directory index block",
1774 retval);
1775 bh = ERR_PTR(retval);
1776 goto errout;
1777 }
1778 } while (retval == 1);
1779
1780 bh = NULL;
1781 errout:
1782 dxtrace(printk(KERN_DEBUG "%s not found\n", fname->usr_fname->name));
1783 success:
1784 dx_release(frames);
1785 return bh;
1786 }
1787
1788 static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
1789 {
1790 struct inode *inode;
1791 struct ext4_dir_entry_2 *de;
1792 struct buffer_head *bh;
1793
1794 if (dentry->d_name.len > EXT4_NAME_LEN)
1795 return ERR_PTR(-ENAMETOOLONG);
1796
1797 bh = ext4_lookup_entry(dir, dentry, &de);
1798 if (IS_ERR(bh))
1799 return ERR_CAST(bh);
1800 inode = NULL;
1801 if (bh) {
1802 __u32 ino = le32_to_cpu(de->inode);
1803 brelse(bh);
1804 if (!ext4_valid_inum(dir->i_sb, ino)) {
1805 EXT4_ERROR_INODE(dir, "bad inode number: %u", ino);
1806 return ERR_PTR(-EFSCORRUPTED);
1807 }
1808 if (unlikely(ino == dir->i_ino)) {
1809 EXT4_ERROR_INODE(dir, "'%pd' linked to parent dir",
1810 dentry);
1811 return ERR_PTR(-EFSCORRUPTED);
1812 }
1813 inode = ext4_iget(dir->i_sb, ino, EXT4_IGET_NORMAL);
1814 if (inode == ERR_PTR(-ESTALE)) {
1815 EXT4_ERROR_INODE(dir,
1816 "deleted inode referenced: %u",
1817 ino);
1818 return ERR_PTR(-EFSCORRUPTED);
1819 }
1820 if (!IS_ERR(inode) && IS_ENCRYPTED(dir) &&
1821 (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) &&
1822 !fscrypt_has_permitted_context(dir, inode)) {
1823 ext4_warning(inode->i_sb,
1824 "Inconsistent encryption contexts: %lu/%lu",
1825 dir->i_ino, inode->i_ino);
1826 iput(inode);
1827 return ERR_PTR(-EPERM);
1828 }
1829 }
1830
1831 if (IS_ENABLED(CONFIG_UNICODE) && !inode && IS_CASEFOLDED(dir)) {
1832 /* Eventually we want to call d_add_ci(dentry, NULL)
1833 * for negative dentries in the encoding case as
1834 * well. For now, prevent the negative dentry
1835 * from being cached.
1836 */
1837 return NULL;
1838 }
1839
1840 return d_splice_alias(inode, dentry);
1841 }
1842
1843
1844 struct dentry *ext4_get_parent(struct dentry *child)
1845 {
1846 __u32 ino;
1847 struct ext4_dir_entry_2 * de;
1848 struct buffer_head *bh;
1849
1850 bh = ext4_find_entry(d_inode(child), &dotdot_name, &de, NULL);
1851 if (IS_ERR(bh))
1852 return ERR_CAST(bh);
1853 if (!bh)
1854 return ERR_PTR(-ENOENT);
1855 ino = le32_to_cpu(de->inode);
1856 brelse(bh);
1857
1858 if (!ext4_valid_inum(child->d_sb, ino)) {
1859 EXT4_ERROR_INODE(d_inode(child),
1860 "bad parent inode number: %u", ino);
1861 return ERR_PTR(-EFSCORRUPTED);
1862 }
1863
1864 return d_obtain_alias(ext4_iget(child->d_sb, ino, EXT4_IGET_NORMAL));
1865 }
1866
1867 /*
1868 * Move count entries from end of map between two memory locations.
1869 * Returns pointer to last entry moved.
1870 */
1871 static struct ext4_dir_entry_2 *
1872 dx_move_dirents(struct inode *dir, char *from, char *to,
1873 struct dx_map_entry *map, int count,
1874 unsigned blocksize)
1875 {
1876 unsigned rec_len = 0;
1877
1878 while (count--) {
1879 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
1880 (from + (map->offs<<2));
1881 rec_len = ext4_dir_rec_len(de->name_len, dir);
1882
1883 memcpy (to, de, rec_len);
1884 ((struct ext4_dir_entry_2 *) to)->rec_len =
1885 ext4_rec_len_to_disk(rec_len, blocksize);
1886
1887 /* wipe dir_entry excluding the rec_len field */
1888 de->inode = 0;
1889 memset(&de->name_len, 0, ext4_rec_len_from_disk(de->rec_len,
1890 blocksize) -
1891 offsetof(struct ext4_dir_entry_2,
1892 name_len));
1893
1894 map++;
1895 to += rec_len;
1896 }
1897 return (struct ext4_dir_entry_2 *) (to - rec_len);
1898 }
1899
1900 /*
1901 * Compact each dir entry in the range to the minimal rec_len.
1902 * Returns pointer to last entry in range.
1903 */
1904 static struct ext4_dir_entry_2 *dx_pack_dirents(struct inode *dir, char *base,
1905 unsigned int blocksize)
1906 {
1907 struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
1908 unsigned rec_len = 0;
1909
1910 prev = to = de;
1911 while ((char*)de < base + blocksize) {
1912 next = ext4_next_entry(de, blocksize);
1913 if (de->inode && de->name_len) {
1914 rec_len = ext4_dir_rec_len(de->name_len, dir);
1915 if (de > to)
1916 memmove(to, de, rec_len);
1917 to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
1918 prev = to;
1919 to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
1920 }
1921 de = next;
1922 }
1923 return prev;
1924 }
1925
1926 /*
1927 * Split a full leaf block to make room for a new dir entry.
1928 * Allocate a new block, and move entries so that they are approx. equally full.
1929 * Returns pointer to de in block into which the new entry will be inserted.
1930 */
1931 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
1932 struct buffer_head **bh,struct dx_frame *frame,
1933 struct dx_hash_info *hinfo)
1934 {
1935 unsigned blocksize = dir->i_sb->s_blocksize;
1936 unsigned continued;
1937 int count;
1938 struct buffer_head *bh2;
1939 ext4_lblk_t newblock;
1940 u32 hash2;
1941 struct dx_map_entry *map;
1942 char *data1 = (*bh)->b_data, *data2;
1943 unsigned split, move, size;
1944 struct ext4_dir_entry_2 *de = NULL, *de2;
1945 int csum_size = 0;
1946 int err = 0, i;
1947
1948 if (ext4_has_metadata_csum(dir->i_sb))
1949 csum_size = sizeof(struct ext4_dir_entry_tail);
1950
1951 bh2 = ext4_append(handle, dir, &newblock);
1952 if (IS_ERR(bh2)) {
1953 brelse(*bh);
1954 *bh = NULL;
1955 return (struct ext4_dir_entry_2 *) bh2;
1956 }
1957
1958 BUFFER_TRACE(*bh, "get_write_access");
1959 err = ext4_journal_get_write_access(handle, dir->i_sb, *bh,
1960 EXT4_JTR_NONE);
1961 if (err)
1962 goto journal_error;
1963
1964 BUFFER_TRACE(frame->bh, "get_write_access");
1965 err = ext4_journal_get_write_access(handle, dir->i_sb, frame->bh,
1966 EXT4_JTR_NONE);
1967 if (err)
1968 goto journal_error;
1969
1970 data2 = bh2->b_data;
1971
1972 /* create map in the end of data2 block */
1973 map = (struct dx_map_entry *) (data2 + blocksize);
1974 count = dx_make_map(dir, *bh, hinfo, map);
1975 if (count < 0) {
1976 err = count;
1977 goto journal_error;
1978 }
1979 map -= count;
1980 dx_sort_map(map, count);
1981 /* Ensure that neither split block is over half full */
1982 size = 0;
1983 move = 0;
1984 for (i = count-1; i >= 0; i--) {
1985 /* is more than half of this entry in 2nd half of the block? */
1986 if (size + map[i].size/2 > blocksize/2)
1987 break;
1988 size += map[i].size;
1989 move++;
1990 }
1991 /*
1992 * map index at which we will split
1993 *
1994 * If the sum of active entries didn't exceed half the block size, just
1995 * split it in half by count; each resulting block will have at least
1996 * half the space free.
1997 */
1998 if (i > 0)
1999 split = count - move;
2000 else
2001 split = count/2;
2002
2003 hash2 = map[split].hash;
2004 continued = split > 0 ? hash2 == map[split - 1].hash : 0;
2005 dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
2006 (unsigned long)dx_get_block(frame->at),
2007 hash2, split, count-split));
2008
2009 /* Fancy dance to stay within two buffers */
2010 de2 = dx_move_dirents(dir, data1, data2, map + split, count - split,
2011 blocksize);
2012 de = dx_pack_dirents(dir, data1, blocksize);
2013 de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
2014 (char *) de,
2015 blocksize);
2016 de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
2017 (char *) de2,
2018 blocksize);
2019 if (csum_size) {
2020 ext4_initialize_dirent_tail(*bh, blocksize);
2021 ext4_initialize_dirent_tail(bh2, blocksize);
2022 }
2023
2024 dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data1,
2025 blocksize, 1));
2026 dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data2,
2027 blocksize, 1));
2028
2029 /* Which block gets the new entry? */
2030 if (hinfo->hash >= hash2) {
2031 swap(*bh, bh2);
2032 de = de2;
2033 }
2034 dx_insert_block(frame, hash2 + continued, newblock);
2035 err = ext4_handle_dirty_dirblock(handle, dir, bh2);
2036 if (err)
2037 goto journal_error;
2038 err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
2039 if (err)
2040 goto journal_error;
2041 brelse(bh2);
2042 dxtrace(dx_show_index("frame", frame->entries));
2043 return de;
2044
2045 journal_error:
2046 brelse(*bh);
2047 brelse(bh2);
2048 *bh = NULL;
2049 ext4_std_error(dir->i_sb, err);
2050 return ERR_PTR(err);
2051 }
2052
2053 int ext4_find_dest_de(struct inode *dir, struct inode *inode,
2054 struct buffer_head *bh,
2055 void *buf, int buf_size,
2056 struct ext4_filename *fname,
2057 struct ext4_dir_entry_2 **dest_de)
2058 {
2059 struct ext4_dir_entry_2 *de;
2060 unsigned short reclen = ext4_dir_rec_len(fname_len(fname), dir);
2061 int nlen, rlen;
2062 unsigned int offset = 0;
2063 char *top;
2064
2065 de = buf;
2066 top = buf + buf_size - reclen;
2067 while ((char *) de <= top) {
2068 if (ext4_check_dir_entry(dir, NULL, de, bh,
2069 buf, buf_size, offset))
2070 return -EFSCORRUPTED;
2071 if (ext4_match(dir, fname, de))
2072 return -EEXIST;
2073 nlen = ext4_dir_rec_len(de->name_len, dir);
2074 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
2075 if ((de->inode ? rlen - nlen : rlen) >= reclen)
2076 break;
2077 de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
2078 offset += rlen;
2079 }
2080 if ((char *) de > top)
2081 return -ENOSPC;
2082
2083 *dest_de = de;
2084 return 0;
2085 }
2086
2087 void ext4_insert_dentry(struct inode *dir,
2088 struct inode *inode,
2089 struct ext4_dir_entry_2 *de,
2090 int buf_size,
2091 struct ext4_filename *fname)
2092 {
2093
2094 int nlen, rlen;
2095
2096 nlen = ext4_dir_rec_len(de->name_len, dir);
2097 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
2098 if (de->inode) {
2099 struct ext4_dir_entry_2 *de1 =
2100 (struct ext4_dir_entry_2 *)((char *)de + nlen);
2101 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, buf_size);
2102 de->rec_len = ext4_rec_len_to_disk(nlen, buf_size);
2103 de = de1;
2104 }
2105 de->file_type = EXT4_FT_UNKNOWN;
2106 de->inode = cpu_to_le32(inode->i_ino);
2107 ext4_set_de_type(inode->i_sb, de, inode->i_mode);
2108 de->name_len = fname_len(fname);
2109 memcpy(de->name, fname_name(fname), fname_len(fname));
2110 if (ext4_hash_in_dirent(dir)) {
2111 struct dx_hash_info *hinfo = &fname->hinfo;
2112
2113 EXT4_DIRENT_HASHES(de)->hash = cpu_to_le32(hinfo->hash);
2114 EXT4_DIRENT_HASHES(de)->minor_hash =
2115 cpu_to_le32(hinfo->minor_hash);
2116 }
2117 }
2118
2119 /*
2120 * Add a new entry into a directory (leaf) block. If de is non-NULL,
2121 * it points to a directory entry which is guaranteed to be large
2122 * enough for new directory entry. If de is NULL, then
2123 * add_dirent_to_buf will attempt search the directory block for
2124 * space. It will return -ENOSPC if no space is available, and -EIO
2125 * and -EEXIST if directory entry already exists.
2126 */
2127 static int add_dirent_to_buf(handle_t *handle, struct ext4_filename *fname,
2128 struct inode *dir,
2129 struct inode *inode, struct ext4_dir_entry_2 *de,
2130 struct buffer_head *bh)
2131 {
2132 unsigned int blocksize = dir->i_sb->s_blocksize;
2133 int csum_size = 0;
2134 int err, err2;
2135
2136 if (ext4_has_metadata_csum(inode->i_sb))
2137 csum_size = sizeof(struct ext4_dir_entry_tail);
2138
2139 if (!de) {
2140 err = ext4_find_dest_de(dir, inode, bh, bh->b_data,
2141 blocksize - csum_size, fname, &de);
2142 if (err)
2143 return err;
2144 }
2145 BUFFER_TRACE(bh, "get_write_access");
2146 err = ext4_journal_get_write_access(handle, dir->i_sb, bh,
2147 EXT4_JTR_NONE);
2148 if (err) {
2149 ext4_std_error(dir->i_sb, err);
2150 return err;
2151 }
2152
2153 /* By now the buffer is marked for journaling */
2154 ext4_insert_dentry(dir, inode, de, blocksize, fname);
2155
2156 /*
2157 * XXX shouldn't update any times until successful
2158 * completion of syscall, but too many callers depend
2159 * on this.
2160 *
2161 * XXX similarly, too many callers depend on
2162 * ext4_new_inode() setting the times, but error
2163 * recovery deletes the inode, so the worst that can
2164 * happen is that the times are slightly out of date
2165 * and/or different from the directory change time.
2166 */
2167 inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
2168 ext4_update_dx_flag(dir);
2169 inode_inc_iversion(dir);
2170 err2 = ext4_mark_inode_dirty(handle, dir);
2171 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
2172 err = ext4_handle_dirty_dirblock(handle, dir, bh);
2173 if (err)
2174 ext4_std_error(dir->i_sb, err);
2175 return err ? err : err2;
2176 }
2177
2178 static bool ext4_check_dx_root(struct inode *dir, struct dx_root *root)
2179 {
2180 struct fake_dirent *fde;
2181 const char *error_msg;
2182 unsigned int rlen;
2183 unsigned int blocksize = dir->i_sb->s_blocksize;
2184 char *blockend = (char *)root + dir->i_sb->s_blocksize;
2185
2186 fde = &root->dot;
2187 if (unlikely(fde->name_len != 1)) {
2188 error_msg = "invalid name_len for '.'";
2189 goto corrupted;
2190 }
2191 if (unlikely(strncmp(root->dot_name, ".", fde->name_len))) {
2192 error_msg = "invalid name for '.'";
2193 goto corrupted;
2194 }
2195 rlen = ext4_rec_len_from_disk(fde->rec_len, blocksize);
2196 if (unlikely((char *)fde + rlen >= blockend)) {
2197 error_msg = "invalid rec_len for '.'";
2198 goto corrupted;
2199 }
2200
2201 fde = &root->dotdot;
2202 if (unlikely(fde->name_len != 2)) {
2203 error_msg = "invalid name_len for '..'";
2204 goto corrupted;
2205 }
2206 if (unlikely(strncmp(root->dotdot_name, "..", fde->name_len))) {
2207 error_msg = "invalid name for '..'";
2208 goto corrupted;
2209 }
2210 rlen = ext4_rec_len_from_disk(fde->rec_len, blocksize);
2211 if (unlikely((char *)fde + rlen >= blockend)) {
2212 error_msg = "invalid rec_len for '..'";
2213 goto corrupted;
2214 }
2215
2216 return true;
2217
2218 corrupted:
2219 EXT4_ERROR_INODE(dir, "Corrupt dir, %s, running e2fsck is recommended",
2220 error_msg);
2221 return false;
2222 }
2223
2224 /*
2225 * This converts a one block unindexed directory to a 3 block indexed
2226 * directory, and adds the dentry to the indexed directory.
2227 */
2228 static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname,
2229 struct inode *dir,
2230 struct inode *inode, struct buffer_head *bh)
2231 {
2232 struct buffer_head *bh2;
2233 struct dx_root *root;
2234 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
2235 struct dx_entry *entries;
2236 struct ext4_dir_entry_2 *de, *de2;
2237 char *data2, *top;
2238 unsigned len;
2239 int retval;
2240 unsigned blocksize;
2241 ext4_lblk_t block;
2242 struct fake_dirent *fde;
2243 int csum_size = 0;
2244
2245 if (ext4_has_metadata_csum(inode->i_sb))
2246 csum_size = sizeof(struct ext4_dir_entry_tail);
2247
2248 blocksize = dir->i_sb->s_blocksize;
2249 dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
2250 BUFFER_TRACE(bh, "get_write_access");
2251 retval = ext4_journal_get_write_access(handle, dir->i_sb, bh,
2252 EXT4_JTR_NONE);
2253 if (retval) {
2254 ext4_std_error(dir->i_sb, retval);
2255 brelse(bh);
2256 return retval;
2257 }
2258
2259 root = (struct dx_root *) bh->b_data;
2260 if (!ext4_check_dx_root(dir, root)) {
2261 brelse(bh);
2262 return -EFSCORRUPTED;
2263 }
2264
2265 /* The 0th block becomes the root, move the dirents out */
2266 fde = &root->dotdot;
2267 de = (struct ext4_dir_entry_2 *)((char *)fde +
2268 ext4_rec_len_from_disk(fde->rec_len, blocksize));
2269 len = ((char *) root) + (blocksize - csum_size) - (char *) de;
2270
2271 /* Allocate new block for the 0th block's dirents */
2272 bh2 = ext4_append(handle, dir, &block);
2273 if (IS_ERR(bh2)) {
2274 brelse(bh);
2275 return PTR_ERR(bh2);
2276 }
2277 ext4_set_inode_flag(dir, EXT4_INODE_INDEX);
2278 data2 = bh2->b_data;
2279
2280 memcpy(data2, de, len);
2281 memset(de, 0, len); /* wipe old data */
2282 de = (struct ext4_dir_entry_2 *) data2;
2283 top = data2 + len;
2284 while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top) {
2285 if (ext4_check_dir_entry(dir, NULL, de, bh2, data2, len,
2286 (char *)de - data2)) {
2287 brelse(bh2);
2288 brelse(bh);
2289 return -EFSCORRUPTED;
2290 }
2291 de = de2;
2292 }
2293 de->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
2294 (char *) de, blocksize);
2295
2296 if (csum_size)
2297 ext4_initialize_dirent_tail(bh2, blocksize);
2298
2299 /* Initialize the root; the dot dirents already exist */
2300 de = (struct ext4_dir_entry_2 *) (&root->dotdot);
2301 de->rec_len = ext4_rec_len_to_disk(
2302 blocksize - ext4_dir_rec_len(2, NULL), blocksize);
2303 memset (&root->info, 0, sizeof(root->info));
2304 root->info.info_length = sizeof(root->info);
2305 if (ext4_hash_in_dirent(dir))
2306 root->info.hash_version = DX_HASH_SIPHASH;
2307 else
2308 root->info.hash_version =
2309 EXT4_SB(dir->i_sb)->s_def_hash_version;
2310
2311 entries = root->entries;
2312 dx_set_block(entries, 1);
2313 dx_set_count(entries, 1);
2314 dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
2315
2316 /* Initialize as for dx_probe */
2317 fname->hinfo.hash_version = root->info.hash_version;
2318 if (fname->hinfo.hash_version <= DX_HASH_TEA)
2319 fname->hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
2320 fname->hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
2321
2322 /* casefolded encrypted hashes are computed on fname setup */
2323 if (!ext4_hash_in_dirent(dir)) {
2324 int err = ext4fs_dirhash(dir, fname_name(fname),
2325 fname_len(fname), &fname->hinfo);
2326 if (err < 0) {
2327 brelse(bh2);
2328 brelse(bh);
2329 return err;
2330 }
2331 }
2332 memset(frames, 0, sizeof(frames));
2333 frame = frames;
2334 frame->entries = entries;
2335 frame->at = entries;
2336 frame->bh = bh;
2337
2338 retval = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
2339 if (retval)
2340 goto out_frames;
2341 retval = ext4_handle_dirty_dirblock(handle, dir, bh2);
2342 if (retval)
2343 goto out_frames;
2344
2345 de = do_split(handle,dir, &bh2, frame, &fname->hinfo);
2346 if (IS_ERR(de)) {
2347 retval = PTR_ERR(de);
2348 goto out_frames;
2349 }
2350
2351 retval = add_dirent_to_buf(handle, fname, dir, inode, de, bh2);
2352 out_frames:
2353 /*
2354 * Even if the block split failed, we have to properly write
2355 * out all the changes we did so far. Otherwise we can end up
2356 * with corrupted filesystem.
2357 */
2358 if (retval)
2359 ext4_mark_inode_dirty(handle, dir);
2360 dx_release(frames);
2361 brelse(bh2);
2362 return retval;
2363 }
2364
2365 /*
2366 * ext4_add_entry()
2367 *
2368 * adds a file entry to the specified directory, using the same
2369 * semantics as ext4_find_entry(). It returns NULL if it failed.
2370 *
2371 * NOTE!! The inode part of 'de' is left at 0 - which means you
2372 * may not sleep between calling this and putting something into
2373 * the entry, as someone else might have used it while you slept.
2374 */
2375 static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
2376 struct inode *inode)
2377 {
2378 struct inode *dir = d_inode(dentry->d_parent);
2379 struct buffer_head *bh = NULL;
2380 struct ext4_dir_entry_2 *de;
2381 struct super_block *sb;
2382 struct ext4_filename fname;
2383 int retval;
2384 int dx_fallback=0;
2385 unsigned blocksize;
2386 ext4_lblk_t block, blocks;
2387 int csum_size = 0;
2388
2389 if (ext4_has_metadata_csum(inode->i_sb))
2390 csum_size = sizeof(struct ext4_dir_entry_tail);
2391
2392 sb = dir->i_sb;
2393 blocksize = sb->s_blocksize;
2394
2395 if (fscrypt_is_nokey_name(dentry))
2396 return -ENOKEY;
2397
2398 #if IS_ENABLED(CONFIG_UNICODE)
2399 if (sb_has_strict_encoding(sb) && IS_CASEFOLDED(dir) &&
2400 utf8_validate(sb->s_encoding, &dentry->d_name))
2401 return -EINVAL;
2402 #endif
2403
2404 retval = ext4_fname_setup_filename(dir, &dentry->d_name, 0, &fname);
2405 if (retval)
2406 return retval;
2407
2408 if (ext4_has_inline_data(dir)) {
2409 retval = ext4_try_add_inline_entry(handle, &fname, dir, inode);
2410 if (retval < 0)
2411 goto out;
2412 if (retval == 1) {
2413 retval = 0;
2414 goto out;
2415 }
2416 }
2417
2418 if (is_dx(dir)) {
2419 retval = ext4_dx_add_entry(handle, &fname, dir, inode);
2420 if (!retval || (retval != ERR_BAD_DX_DIR))
2421 goto out;
2422 /* Can we just ignore htree data? */
2423 if (ext4_has_metadata_csum(sb)) {
2424 EXT4_ERROR_INODE(dir,
2425 "Directory has corrupted htree index.");
2426 retval = -EFSCORRUPTED;
2427 goto out;
2428 }
2429 ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
2430 dx_fallback++;
2431 retval = ext4_mark_inode_dirty(handle, dir);
2432 if (unlikely(retval))
2433 goto out;
2434 }
2435 blocks = dir->i_size >> sb->s_blocksize_bits;
2436 for (block = 0; block < blocks; block++) {
2437 bh = ext4_read_dirblock(dir, block, DIRENT);
2438 if (bh == NULL) {
2439 bh = ext4_bread(handle, dir, block,
2440 EXT4_GET_BLOCKS_CREATE);
2441 goto add_to_new_block;
2442 }
2443 if (IS_ERR(bh)) {
2444 retval = PTR_ERR(bh);
2445 bh = NULL;
2446 goto out;
2447 }
2448 retval = add_dirent_to_buf(handle, &fname, dir, inode,
2449 NULL, bh);
2450 if (retval != -ENOSPC)
2451 goto out;
2452
2453 if (blocks == 1 && !dx_fallback &&
2454 ext4_has_feature_dir_index(sb)) {
2455 retval = make_indexed_dir(handle, &fname, dir,
2456 inode, bh);
2457 bh = NULL; /* make_indexed_dir releases bh */
2458 goto out;
2459 }
2460 brelse(bh);
2461 }
2462 bh = ext4_append(handle, dir, &block);
2463 add_to_new_block:
2464 if (IS_ERR(bh)) {
2465 retval = PTR_ERR(bh);
2466 bh = NULL;
2467 goto out;
2468 }
2469 de = (struct ext4_dir_entry_2 *) bh->b_data;
2470 de->inode = 0;
2471 de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize);
2472
2473 if (csum_size)
2474 ext4_initialize_dirent_tail(bh, blocksize);
2475
2476 retval = add_dirent_to_buf(handle, &fname, dir, inode, de, bh);
2477 out:
2478 ext4_fname_free_filename(&fname);
2479 brelse(bh);
2480 if (retval == 0)
2481 ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY);
2482 return retval;
2483 }
2484
2485 /*
2486 * Returns 0 for success, or a negative error value
2487 */
2488 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
2489 struct inode *dir, struct inode *inode)
2490 {
2491 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
2492 struct dx_entry *entries, *at;
2493 struct buffer_head *bh;
2494 struct super_block *sb = dir->i_sb;
2495 struct ext4_dir_entry_2 *de;
2496 int restart;
2497 int err;
2498
2499 again:
2500 restart = 0;
2501 frame = dx_probe(fname, dir, NULL, frames);
2502 if (IS_ERR(frame))
2503 return PTR_ERR(frame);
2504 entries = frame->entries;
2505 at = frame->at;
2506 bh = ext4_read_dirblock(dir, dx_get_block(frame->at), DIRENT_HTREE);
2507 if (IS_ERR(bh)) {
2508 err = PTR_ERR(bh);
2509 bh = NULL;
2510 goto cleanup;
2511 }
2512
2513 BUFFER_TRACE(bh, "get_write_access");
2514 err = ext4_journal_get_write_access(handle, sb, bh, EXT4_JTR_NONE);
2515 if (err)
2516 goto journal_error;
2517
2518 err = add_dirent_to_buf(handle, fname, dir, inode, NULL, bh);
2519 if (err != -ENOSPC)
2520 goto cleanup;
2521
2522 err = 0;
2523 /* Block full, should compress but for now just split */
2524 dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
2525 dx_get_count(entries), dx_get_limit(entries)));
2526 /* Need to split index? */
2527 if (dx_get_count(entries) == dx_get_limit(entries)) {
2528 ext4_lblk_t newblock;
2529 int levels = frame - frames + 1;
2530 unsigned int icount;
2531 int add_level = 1;
2532 struct dx_entry *entries2;
2533 struct dx_node *node2;
2534 struct buffer_head *bh2;
2535
2536 while (frame > frames) {
2537 if (dx_get_count((frame - 1)->entries) <
2538 dx_get_limit((frame - 1)->entries)) {
2539 add_level = 0;
2540 break;
2541 }
2542 frame--; /* split higher index block */
2543 at = frame->at;
2544 entries = frame->entries;
2545 restart = 1;
2546 }
2547 if (add_level && levels == ext4_dir_htree_level(sb)) {
2548 ext4_warning(sb, "Directory (ino: %lu) index full, "
2549 "reach max htree level :%d",
2550 dir->i_ino, levels);
2551 if (ext4_dir_htree_level(sb) < EXT4_HTREE_LEVEL) {
2552 ext4_warning(sb, "Large directory feature is "
2553 "not enabled on this "
2554 "filesystem");
2555 }
2556 err = -ENOSPC;
2557 goto cleanup;
2558 }
2559 icount = dx_get_count(entries);
2560 bh2 = ext4_append(handle, dir, &newblock);
2561 if (IS_ERR(bh2)) {
2562 err = PTR_ERR(bh2);
2563 goto cleanup;
2564 }
2565 node2 = (struct dx_node *)(bh2->b_data);
2566 entries2 = node2->entries;
2567 memset(&node2->fake, 0, sizeof(struct fake_dirent));
2568 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
2569 sb->s_blocksize);
2570 BUFFER_TRACE(frame->bh, "get_write_access");
2571 err = ext4_journal_get_write_access(handle, sb, frame->bh,
2572 EXT4_JTR_NONE);
2573 if (err)
2574 goto journal_error;
2575 if (!add_level) {
2576 unsigned icount1 = icount/2, icount2 = icount - icount1;
2577 unsigned hash2 = dx_get_hash(entries + icount1);
2578 dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
2579 icount1, icount2));
2580
2581 BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
2582 err = ext4_journal_get_write_access(handle, sb,
2583 (frame - 1)->bh,
2584 EXT4_JTR_NONE);
2585 if (err)
2586 goto journal_error;
2587
2588 memcpy((char *) entries2, (char *) (entries + icount1),
2589 icount2 * sizeof(struct dx_entry));
2590 dx_set_count(entries, icount1);
2591 dx_set_count(entries2, icount2);
2592 dx_set_limit(entries2, dx_node_limit(dir));
2593
2594 /* Which index block gets the new entry? */
2595 if (at - entries >= icount1) {
2596 frame->at = at - entries - icount1 + entries2;
2597 frame->entries = entries = entries2;
2598 swap(frame->bh, bh2);
2599 }
2600 dx_insert_block((frame - 1), hash2, newblock);
2601 dxtrace(dx_show_index("node", frame->entries));
2602 dxtrace(dx_show_index("node",
2603 ((struct dx_node *) bh2->b_data)->entries));
2604 err = ext4_handle_dirty_dx_node(handle, dir, bh2);
2605 if (err)
2606 goto journal_error;
2607 brelse (bh2);
2608 err = ext4_handle_dirty_dx_node(handle, dir,
2609 (frame - 1)->bh);
2610 if (err)
2611 goto journal_error;
2612 err = ext4_handle_dirty_dx_node(handle, dir,
2613 frame->bh);
2614 if (restart || err)
2615 goto journal_error;
2616 } else {
2617 struct dx_root *dxroot;
2618 memcpy((char *) entries2, (char *) entries,
2619 icount * sizeof(struct dx_entry));
2620 dx_set_limit(entries2, dx_node_limit(dir));
2621
2622 /* Set up root */
2623 dx_set_count(entries, 1);
2624 dx_set_block(entries + 0, newblock);
2625 dxroot = (struct dx_root *)frames[0].bh->b_data;
2626 dxroot->info.indirect_levels += 1;
2627 dxtrace(printk(KERN_DEBUG
2628 "Creating %d level index...\n",
2629 dxroot->info.indirect_levels));
2630 err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
2631 if (err)
2632 goto journal_error;
2633 err = ext4_handle_dirty_dx_node(handle, dir, bh2);
2634 brelse(bh2);
2635 restart = 1;
2636 goto journal_error;
2637 }
2638 }
2639 de = do_split(handle, dir, &bh, frame, &fname->hinfo);
2640 if (IS_ERR(de)) {
2641 err = PTR_ERR(de);
2642 goto cleanup;
2643 }
2644 err = add_dirent_to_buf(handle, fname, dir, inode, de, bh);
2645 goto cleanup;
2646
2647 journal_error:
2648 ext4_std_error(dir->i_sb, err); /* this is a no-op if err == 0 */
2649 cleanup:
2650 brelse(bh);
2651 dx_release(frames);
2652 /* @restart is true means htree-path has been changed, we need to
2653 * repeat dx_probe() to find out valid htree-path
2654 */
2655 if (restart && err == 0)
2656 goto again;
2657 return err;
2658 }
2659
2660 /*
2661 * ext4_generic_delete_entry deletes a directory entry by merging it
2662 * with the previous entry
2663 */
2664 int ext4_generic_delete_entry(struct inode *dir,
2665 struct ext4_dir_entry_2 *de_del,
2666 struct buffer_head *bh,
2667 void *entry_buf,
2668 int buf_size,
2669 int csum_size)
2670 {
2671 struct ext4_dir_entry_2 *de, *pde;
2672 unsigned int blocksize = dir->i_sb->s_blocksize;
2673 int i;
2674
2675 i = 0;
2676 pde = NULL;
2677 de = entry_buf;
2678 while (i < buf_size - csum_size) {
2679 if (ext4_check_dir_entry(dir, NULL, de, bh,
2680 entry_buf, buf_size, i))
2681 return -EFSCORRUPTED;
2682 if (de == de_del) {
2683 if (pde) {
2684 pde->rec_len = ext4_rec_len_to_disk(
2685 ext4_rec_len_from_disk(pde->rec_len,
2686 blocksize) +
2687 ext4_rec_len_from_disk(de->rec_len,
2688 blocksize),
2689 blocksize);
2690
2691 /* wipe entire dir_entry */
2692 memset(de, 0, ext4_rec_len_from_disk(de->rec_len,
2693 blocksize));
2694 } else {
2695 /* wipe dir_entry excluding the rec_len field */
2696 de->inode = 0;
2697 memset(&de->name_len, 0,
2698 ext4_rec_len_from_disk(de->rec_len,
2699 blocksize) -
2700 offsetof(struct ext4_dir_entry_2,
2701 name_len));
2702 }
2703
2704 inode_inc_iversion(dir);
2705 return 0;
2706 }
2707 i += ext4_rec_len_from_disk(de->rec_len, blocksize);
2708 pde = de;
2709 de = ext4_next_entry(de, blocksize);
2710 }
2711 return -ENOENT;
2712 }
2713
2714 static int ext4_delete_entry(handle_t *handle,
2715 struct inode *dir,
2716 struct ext4_dir_entry_2 *de_del,
2717 struct buffer_head *bh)
2718 {
2719 int err, csum_size = 0;
2720
2721 if (ext4_has_inline_data(dir)) {
2722 int has_inline_data = 1;
2723 err = ext4_delete_inline_entry(handle, dir, de_del, bh,
2724 &has_inline_data);
2725 if (has_inline_data)
2726 return err;
2727 }
2728
2729 if (ext4_has_metadata_csum(dir->i_sb))
2730 csum_size = sizeof(struct ext4_dir_entry_tail);
2731
2732 BUFFER_TRACE(bh, "get_write_access");
2733 err = ext4_journal_get_write_access(handle, dir->i_sb, bh,
2734 EXT4_JTR_NONE);
2735 if (unlikely(err))
2736 goto out;
2737
2738 err = ext4_generic_delete_entry(dir, de_del, bh, bh->b_data,
2739 dir->i_sb->s_blocksize, csum_size);
2740 if (err)
2741 goto out;
2742
2743 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
2744 err = ext4_handle_dirty_dirblock(handle, dir, bh);
2745 if (unlikely(err))
2746 goto out;
2747
2748 return 0;
2749 out:
2750 if (err != -ENOENT)
2751 ext4_std_error(dir->i_sb, err);
2752 return err;
2753 }
2754
2755 /*
2756 * Set directory link count to 1 if nlinks > EXT4_LINK_MAX, or if nlinks == 2
2757 * since this indicates that nlinks count was previously 1 to avoid overflowing
2758 * the 16-bit i_links_count field on disk. Directories with i_nlink == 1 mean
2759 * that subdirectory link counts are not being maintained accurately.
2760 *
2761 * The caller has already checked for i_nlink overflow in case the DIR_LINK
2762 * feature is not enabled and returned -EMLINK. The is_dx() check is a proxy
2763 * for checking S_ISDIR(inode) (since the INODE_INDEX feature will not be set
2764 * on regular files) and to avoid creating huge/slow non-HTREE directories.
2765 */
2766 static void ext4_inc_count(struct inode *inode)
2767 {
2768 inc_nlink(inode);
2769 if (is_dx(inode) &&
2770 (inode->i_nlink > EXT4_LINK_MAX || inode->i_nlink == 2))
2771 set_nlink(inode, 1);
2772 }
2773
2774 /*
2775 * If a directory had nlink == 1, then we should let it be 1. This indicates
2776 * directory has >EXT4_LINK_MAX subdirs.
2777 */
2778 static void ext4_dec_count(struct inode *inode)
2779 {
2780 if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
2781 drop_nlink(inode);
2782 }
2783
2784
2785 /*
2786 * Add non-directory inode to a directory. On success, the inode reference is
2787 * consumed by dentry is instantiation. This is also indicated by clearing of
2788 * *inodep pointer. On failure, the caller is responsible for dropping the
2789 * inode reference in the safe context.
2790 */
2791 static int ext4_add_nondir(handle_t *handle,
2792 struct dentry *dentry, struct inode **inodep)
2793 {
2794 struct inode *dir = d_inode(dentry->d_parent);
2795 struct inode *inode = *inodep;
2796 int err = ext4_add_entry(handle, dentry, inode);
2797 if (!err) {
2798 err = ext4_mark_inode_dirty(handle, inode);
2799 if (IS_DIRSYNC(dir))
2800 ext4_handle_sync(handle);
2801 d_instantiate_new(dentry, inode);
2802 *inodep = NULL;
2803 return err;
2804 }
2805 drop_nlink(inode);
2806 ext4_mark_inode_dirty(handle, inode);
2807 ext4_orphan_add(handle, inode);
2808 unlock_new_inode(inode);
2809 return err;
2810 }
2811
2812 /*
2813 * By the time this is called, we already have created
2814 * the directory cache entry for the new file, but it
2815 * is so far negative - it has no inode.
2816 *
2817 * If the create succeeds, we fill in the inode information
2818 * with d_instantiate().
2819 */
2820 static int ext4_create(struct mnt_idmap *idmap, struct inode *dir,
2821 struct dentry *dentry, umode_t mode, bool excl)
2822 {
2823 handle_t *handle;
2824 struct inode *inode;
2825 int err, credits, retries = 0;
2826
2827 err = dquot_initialize(dir);
2828 if (err)
2829 return err;
2830
2831 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2832 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2833 retry:
2834 inode = ext4_new_inode_start_handle(idmap, dir, mode, &dentry->d_name,
2835 0, NULL, EXT4_HT_DIR, credits);
2836 handle = ext4_journal_current_handle();
2837 err = PTR_ERR(inode);
2838 if (!IS_ERR(inode)) {
2839 inode->i_op = &ext4_file_inode_operations;
2840 inode->i_fop = &ext4_file_operations;
2841 ext4_set_aops(inode);
2842 err = ext4_add_nondir(handle, dentry, &inode);
2843 if (!err)
2844 ext4_fc_track_create(handle, dentry);
2845 }
2846 if (handle)
2847 ext4_journal_stop(handle);
2848 if (!IS_ERR_OR_NULL(inode))
2849 iput(inode);
2850 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2851 goto retry;
2852 return err;
2853 }
2854
2855 static int ext4_mknod(struct mnt_idmap *idmap, struct inode *dir,
2856 struct dentry *dentry, umode_t mode, dev_t rdev)
2857 {
2858 handle_t *handle;
2859 struct inode *inode;
2860 int err, credits, retries = 0;
2861
2862 err = dquot_initialize(dir);
2863 if (err)
2864 return err;
2865
2866 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2867 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2868 retry:
2869 inode = ext4_new_inode_start_handle(idmap, dir, mode, &dentry->d_name,
2870 0, NULL, EXT4_HT_DIR, credits);
2871 handle = ext4_journal_current_handle();
2872 err = PTR_ERR(inode);
2873 if (!IS_ERR(inode)) {
2874 init_special_inode(inode, inode->i_mode, rdev);
2875 inode->i_op = &ext4_special_inode_operations;
2876 err = ext4_add_nondir(handle, dentry, &inode);
2877 if (!err)
2878 ext4_fc_track_create(handle, dentry);
2879 }
2880 if (handle)
2881 ext4_journal_stop(handle);
2882 if (!IS_ERR_OR_NULL(inode))
2883 iput(inode);
2884 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2885 goto retry;
2886 return err;
2887 }
2888
2889 static int ext4_tmpfile(struct mnt_idmap *idmap, struct inode *dir,
2890 struct file *file, umode_t mode)
2891 {
2892 handle_t *handle;
2893 struct inode *inode;
2894 int err, retries = 0;
2895
2896 err = dquot_initialize(dir);
2897 if (err)
2898 return err;
2899
2900 retry:
2901 inode = ext4_new_inode_start_handle(idmap, dir, mode,
2902 NULL, 0, NULL,
2903 EXT4_HT_DIR,
2904 EXT4_MAXQUOTAS_TRANS_BLOCKS(dir->i_sb) +
2905 4 + EXT4_XATTR_TRANS_BLOCKS);
2906 handle = ext4_journal_current_handle();
2907 err = PTR_ERR(inode);
2908 if (!IS_ERR(inode)) {
2909 inode->i_op = &ext4_file_inode_operations;
2910 inode->i_fop = &ext4_file_operations;
2911 ext4_set_aops(inode);
2912 d_tmpfile(file, inode);
2913 err = ext4_orphan_add(handle, inode);
2914 if (err)
2915 goto err_unlock_inode;
2916 mark_inode_dirty(inode);
2917 unlock_new_inode(inode);
2918 }
2919 if (handle)
2920 ext4_journal_stop(handle);
2921 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2922 goto retry;
2923 return finish_open_simple(file, err);
2924 err_unlock_inode:
2925 ext4_journal_stop(handle);
2926 unlock_new_inode(inode);
2927 return err;
2928 }
2929
2930 struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
2931 struct ext4_dir_entry_2 *de,
2932 int blocksize, int csum_size,
2933 unsigned int parent_ino, int dotdot_real_len)
2934 {
2935 de->inode = cpu_to_le32(inode->i_ino);
2936 de->name_len = 1;
2937 de->rec_len = ext4_rec_len_to_disk(ext4_dir_rec_len(de->name_len, NULL),
2938 blocksize);
2939 strcpy(de->name, ".");
2940 ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2941
2942 de = ext4_next_entry(de, blocksize);
2943 de->inode = cpu_to_le32(parent_ino);
2944 de->name_len = 2;
2945 if (!dotdot_real_len)
2946 de->rec_len = ext4_rec_len_to_disk(blocksize -
2947 (csum_size + ext4_dir_rec_len(1, NULL)),
2948 blocksize);
2949 else
2950 de->rec_len = ext4_rec_len_to_disk(
2951 ext4_dir_rec_len(de->name_len, NULL),
2952 blocksize);
2953 strcpy(de->name, "..");
2954 ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2955
2956 return ext4_next_entry(de, blocksize);
2957 }
2958
2959 int ext4_init_new_dir(handle_t *handle, struct inode *dir,
2960 struct inode *inode)
2961 {
2962 struct buffer_head *dir_block = NULL;
2963 struct ext4_dir_entry_2 *de;
2964 ext4_lblk_t block = 0;
2965 unsigned int blocksize = dir->i_sb->s_blocksize;
2966 int csum_size = 0;
2967 int err;
2968
2969 if (ext4_has_metadata_csum(dir->i_sb))
2970 csum_size = sizeof(struct ext4_dir_entry_tail);
2971
2972 if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
2973 err = ext4_try_create_inline_dir(handle, dir, inode);
2974 if (err < 0 && err != -ENOSPC)
2975 goto out;
2976 if (!err)
2977 goto out;
2978 }
2979
2980 inode->i_size = 0;
2981 dir_block = ext4_append(handle, inode, &block);
2982 if (IS_ERR(dir_block))
2983 return PTR_ERR(dir_block);
2984 de = (struct ext4_dir_entry_2 *)dir_block->b_data;
2985 ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0);
2986 set_nlink(inode, 2);
2987 if (csum_size)
2988 ext4_initialize_dirent_tail(dir_block, blocksize);
2989
2990 BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
2991 err = ext4_handle_dirty_dirblock(handle, inode, dir_block);
2992 if (err)
2993 goto out;
2994 set_buffer_verified(dir_block);
2995 out:
2996 brelse(dir_block);
2997 return err;
2998 }
2999
3000 static int ext4_mkdir(struct mnt_idmap *idmap, struct inode *dir,
3001 struct dentry *dentry, umode_t mode)
3002 {
3003 handle_t *handle;
3004 struct inode *inode;
3005 int err, err2 = 0, credits, retries = 0;
3006
3007 if (EXT4_DIR_LINK_MAX(dir))
3008 return -EMLINK;
3009
3010 err = dquot_initialize(dir);
3011 if (err)
3012 return err;
3013
3014 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3015 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
3016 retry:
3017 inode = ext4_new_inode_start_handle(idmap, dir, S_IFDIR | mode,
3018 &dentry->d_name,
3019 0, NULL, EXT4_HT_DIR, credits);
3020 handle = ext4_journal_current_handle();
3021 err = PTR_ERR(inode);
3022 if (IS_ERR(inode))
3023 goto out_stop;
3024
3025 inode->i_op = &ext4_dir_inode_operations;
3026 inode->i_fop = &ext4_dir_operations;
3027 err = ext4_init_new_dir(handle, dir, inode);
3028 if (err)
3029 goto out_clear_inode;
3030 err = ext4_mark_inode_dirty(handle, inode);
3031 if (!err)
3032 err = ext4_add_entry(handle, dentry, inode);
3033 if (err) {
3034 out_clear_inode:
3035 clear_nlink(inode);
3036 ext4_orphan_add(handle, inode);
3037 unlock_new_inode(inode);
3038 err2 = ext4_mark_inode_dirty(handle, inode);
3039 if (unlikely(err2))
3040 err = err2;
3041 ext4_journal_stop(handle);
3042 iput(inode);
3043 goto out_retry;
3044 }
3045 ext4_inc_count(dir);
3046
3047 ext4_update_dx_flag(dir);
3048 err = ext4_mark_inode_dirty(handle, dir);
3049 if (err)
3050 goto out_clear_inode;
3051 d_instantiate_new(dentry, inode);
3052 ext4_fc_track_create(handle, dentry);
3053 if (IS_DIRSYNC(dir))
3054 ext4_handle_sync(handle);
3055
3056 out_stop:
3057 if (handle)
3058 ext4_journal_stop(handle);
3059 out_retry:
3060 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
3061 goto retry;
3062 return err;
3063 }
3064
3065 /*
3066 * routine to check that the specified directory is empty (for rmdir)
3067 */
3068 bool ext4_empty_dir(struct inode *inode)
3069 {
3070 unsigned int offset;
3071 struct buffer_head *bh;
3072 struct ext4_dir_entry_2 *de;
3073 struct super_block *sb;
3074
3075 if (ext4_has_inline_data(inode)) {
3076 int has_inline_data = 1;
3077 int ret;
3078
3079 ret = empty_inline_dir(inode, &has_inline_data);
3080 if (has_inline_data)
3081 return ret;
3082 }
3083
3084 sb = inode->i_sb;
3085 if (inode->i_size < ext4_dir_rec_len(1, NULL) +
3086 ext4_dir_rec_len(2, NULL)) {
3087 EXT4_ERROR_INODE(inode, "invalid size");
3088 return false;
3089 }
3090 bh = ext4_read_dirblock(inode, 0, EITHER);
3091 if (IS_ERR(bh))
3092 return false;
3093
3094 de = (struct ext4_dir_entry_2 *) bh->b_data;
3095 if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, bh->b_size,
3096 0) ||
3097 le32_to_cpu(de->inode) != inode->i_ino || strcmp(".", de->name)) {
3098 ext4_warning_inode(inode, "directory missing '.'");
3099 brelse(bh);
3100 return false;
3101 }
3102 offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
3103 de = ext4_next_entry(de, sb->s_blocksize);
3104 if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, bh->b_size,
3105 offset) ||
3106 le32_to_cpu(de->inode) == 0 || strcmp("..", de->name)) {
3107 ext4_warning_inode(inode, "directory missing '..'");
3108 brelse(bh);
3109 return false;
3110 }
3111 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
3112 while (offset < inode->i_size) {
3113 if (!(offset & (sb->s_blocksize - 1))) {
3114 unsigned int lblock;
3115 brelse(bh);
3116 lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb);
3117 bh = ext4_read_dirblock(inode, lblock, EITHER);
3118 if (bh == NULL) {
3119 offset += sb->s_blocksize;
3120 continue;
3121 }
3122 if (IS_ERR(bh))
3123 return false;
3124 }
3125 de = (struct ext4_dir_entry_2 *) (bh->b_data +
3126 (offset & (sb->s_blocksize - 1)));
3127 if (ext4_check_dir_entry(inode, NULL, de, bh,
3128 bh->b_data, bh->b_size, offset) ||
3129 le32_to_cpu(de->inode)) {
3130 brelse(bh);
3131 return false;
3132 }
3133 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
3134 }
3135 brelse(bh);
3136 return true;
3137 }
3138
3139 static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
3140 {
3141 int retval;
3142 struct inode *inode;
3143 struct buffer_head *bh;
3144 struct ext4_dir_entry_2 *de;
3145 handle_t *handle = NULL;
3146
3147 if (unlikely(ext4_forced_shutdown(dir->i_sb)))
3148 return -EIO;
3149
3150 /* Initialize quotas before so that eventual writes go in
3151 * separate transaction */
3152 retval = dquot_initialize(dir);
3153 if (retval)
3154 return retval;
3155 retval = dquot_initialize(d_inode(dentry));
3156 if (retval)
3157 return retval;
3158
3159 retval = -ENOENT;
3160 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
3161 if (IS_ERR(bh))
3162 return PTR_ERR(bh);
3163 if (!bh)
3164 goto end_rmdir;
3165
3166 inode = d_inode(dentry);
3167
3168 retval = -EFSCORRUPTED;
3169 if (le32_to_cpu(de->inode) != inode->i_ino)
3170 goto end_rmdir;
3171
3172 retval = -ENOTEMPTY;
3173 if (!ext4_empty_dir(inode))
3174 goto end_rmdir;
3175
3176 handle = ext4_journal_start(dir, EXT4_HT_DIR,
3177 EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
3178 if (IS_ERR(handle)) {
3179 retval = PTR_ERR(handle);
3180 handle = NULL;
3181 goto end_rmdir;
3182 }
3183
3184 if (IS_DIRSYNC(dir))
3185 ext4_handle_sync(handle);
3186
3187 retval = ext4_delete_entry(handle, dir, de, bh);
3188 if (retval)
3189 goto end_rmdir;
3190 if (!EXT4_DIR_LINK_EMPTY(inode))
3191 ext4_warning_inode(inode,
3192 "empty directory '%.*s' has too many links (%u)",
3193 dentry->d_name.len, dentry->d_name.name,
3194 inode->i_nlink);
3195 inode_inc_iversion(inode);
3196 clear_nlink(inode);
3197 /* There's no need to set i_disksize: the fact that i_nlink is
3198 * zero will ensure that the right thing happens during any
3199 * recovery. */
3200 inode->i_size = 0;
3201 ext4_orphan_add(handle, inode);
3202 inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
3203 inode_set_ctime_current(inode);
3204 retval = ext4_mark_inode_dirty(handle, inode);
3205 if (retval)
3206 goto end_rmdir;
3207 ext4_dec_count(dir);
3208 ext4_update_dx_flag(dir);
3209 ext4_fc_track_unlink(handle, dentry);
3210 retval = ext4_mark_inode_dirty(handle, dir);
3211
3212 /* VFS negative dentries are incompatible with Encoding and
3213 * Case-insensitiveness. Eventually we'll want avoid
3214 * invalidating the dentries here, alongside with returning the
3215 * negative dentries at ext4_lookup(), when it is better
3216 * supported by the VFS for the CI case.
3217 */
3218 if (IS_ENABLED(CONFIG_UNICODE) && IS_CASEFOLDED(dir))
3219 d_invalidate(dentry);
3220
3221 end_rmdir:
3222 brelse(bh);
3223 if (handle)
3224 ext4_journal_stop(handle);
3225 return retval;
3226 }
3227
3228 int __ext4_unlink(struct inode *dir, const struct qstr *d_name,
3229 struct inode *inode,
3230 struct dentry *dentry /* NULL during fast_commit recovery */)
3231 {
3232 int retval = -ENOENT;
3233 struct buffer_head *bh;
3234 struct ext4_dir_entry_2 *de;
3235 handle_t *handle;
3236 int skip_remove_dentry = 0;
3237
3238 /*
3239 * Keep this outside the transaction; it may have to set up the
3240 * directory's encryption key, which isn't GFP_NOFS-safe.
3241 */
3242 bh = ext4_find_entry(dir, d_name, &de, NULL);
3243 if (IS_ERR(bh))
3244 return PTR_ERR(bh);
3245
3246 if (!bh)
3247 return -ENOENT;
3248
3249 if (le32_to_cpu(de->inode) != inode->i_ino) {
3250 /*
3251 * It's okay if we find dont find dentry which matches
3252 * the inode. That's because it might have gotten
3253 * renamed to a different inode number
3254 */
3255 if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
3256 skip_remove_dentry = 1;
3257 else
3258 goto out_bh;
3259 }
3260
3261 handle = ext4_journal_start(dir, EXT4_HT_DIR,
3262 EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
3263 if (IS_ERR(handle)) {
3264 retval = PTR_ERR(handle);
3265 goto out_bh;
3266 }
3267
3268 if (IS_DIRSYNC(dir))
3269 ext4_handle_sync(handle);
3270
3271 if (!skip_remove_dentry) {
3272 retval = ext4_delete_entry(handle, dir, de, bh);
3273 if (retval)
3274 goto out_handle;
3275 inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
3276 ext4_update_dx_flag(dir);
3277 retval = ext4_mark_inode_dirty(handle, dir);
3278 if (retval)
3279 goto out_handle;
3280 } else {
3281 retval = 0;
3282 }
3283 if (inode->i_nlink == 0)
3284 ext4_warning_inode(inode, "Deleting file '%.*s' with no links",
3285 d_name->len, d_name->name);
3286 else
3287 drop_nlink(inode);
3288 if (!inode->i_nlink)
3289 ext4_orphan_add(handle, inode);
3290 inode_set_ctime_current(inode);
3291 retval = ext4_mark_inode_dirty(handle, inode);
3292 if (dentry && !retval)
3293 ext4_fc_track_unlink(handle, dentry);
3294 out_handle:
3295 ext4_journal_stop(handle);
3296 out_bh:
3297 brelse(bh);
3298 return retval;
3299 }
3300
3301 static int ext4_unlink(struct inode *dir, struct dentry *dentry)
3302 {
3303 int retval;
3304
3305 if (unlikely(ext4_forced_shutdown(dir->i_sb)))
3306 return -EIO;
3307
3308 trace_ext4_unlink_enter(dir, dentry);
3309 /*
3310 * Initialize quotas before so that eventual writes go
3311 * in separate transaction
3312 */
3313 retval = dquot_initialize(dir);
3314 if (retval)
3315 goto out_trace;
3316 retval = dquot_initialize(d_inode(dentry));
3317 if (retval)
3318 goto out_trace;
3319
3320 retval = __ext4_unlink(dir, &dentry->d_name, d_inode(dentry), dentry);
3321
3322 /* VFS negative dentries are incompatible with Encoding and
3323 * Case-insensitiveness. Eventually we'll want avoid
3324 * invalidating the dentries here, alongside with returning the
3325 * negative dentries at ext4_lookup(), when it is better
3326 * supported by the VFS for the CI case.
3327 */
3328 if (IS_ENABLED(CONFIG_UNICODE) && IS_CASEFOLDED(dir))
3329 d_invalidate(dentry);
3330
3331 out_trace:
3332 trace_ext4_unlink_exit(dentry, retval);
3333 return retval;
3334 }
3335
3336 static int ext4_init_symlink_block(handle_t *handle, struct inode *inode,
3337 struct fscrypt_str *disk_link)
3338 {
3339 struct buffer_head *bh;
3340 char *kaddr;
3341 int err = 0;
3342
3343 bh = ext4_bread(handle, inode, 0, EXT4_GET_BLOCKS_CREATE);
3344 if (IS_ERR(bh))
3345 return PTR_ERR(bh);
3346
3347 BUFFER_TRACE(bh, "get_write_access");
3348 err = ext4_journal_get_write_access(handle, inode->i_sb, bh, EXT4_JTR_NONE);
3349 if (err)
3350 goto out;
3351
3352 kaddr = (char *)bh->b_data;
3353 memcpy(kaddr, disk_link->name, disk_link->len);
3354 inode->i_size = disk_link->len - 1;
3355 EXT4_I(inode)->i_disksize = inode->i_size;
3356 err = ext4_handle_dirty_metadata(handle, inode, bh);
3357 out:
3358 brelse(bh);
3359 return err;
3360 }
3361
3362 static int ext4_symlink(struct mnt_idmap *idmap, struct inode *dir,
3363 struct dentry *dentry, const char *symname)
3364 {
3365 handle_t *handle;
3366 struct inode *inode;
3367 int err, len = strlen(symname);
3368 int credits;
3369 struct fscrypt_str disk_link;
3370 int retries = 0;
3371
3372 if (unlikely(ext4_forced_shutdown(dir->i_sb)))
3373 return -EIO;
3374
3375 err = fscrypt_prepare_symlink(dir, symname, len, dir->i_sb->s_blocksize,
3376 &disk_link);
3377 if (err)
3378 return err;
3379
3380 err = dquot_initialize(dir);
3381 if (err)
3382 return err;
3383
3384 /*
3385 * EXT4_INDEX_EXTRA_TRANS_BLOCKS for addition of entry into the
3386 * directory. +3 for inode, inode bitmap, group descriptor allocation.
3387 * EXT4_DATA_TRANS_BLOCKS for the data block allocation and
3388 * modification.
3389 */
3390 credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3391 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3;
3392 retry:
3393 inode = ext4_new_inode_start_handle(idmap, dir, S_IFLNK|S_IRWXUGO,
3394 &dentry->d_name, 0, NULL,
3395 EXT4_HT_DIR, credits);
3396 handle = ext4_journal_current_handle();
3397 if (IS_ERR(inode)) {
3398 if (handle)
3399 ext4_journal_stop(handle);
3400 err = PTR_ERR(inode);
3401 goto out_retry;
3402 }
3403
3404 if (IS_ENCRYPTED(inode)) {
3405 err = fscrypt_encrypt_symlink(inode, symname, len, &disk_link);
3406 if (err)
3407 goto err_drop_inode;
3408 inode->i_op = &ext4_encrypted_symlink_inode_operations;
3409 } else {
3410 if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
3411 inode->i_op = &ext4_symlink_inode_operations;
3412 } else {
3413 inode->i_op = &ext4_fast_symlink_inode_operations;
3414 inode->i_link = (char *)&EXT4_I(inode)->i_data;
3415 }
3416 }
3417
3418 if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
3419 /* alloc symlink block and fill it */
3420 err = ext4_init_symlink_block(handle, inode, &disk_link);
3421 if (err)
3422 goto err_drop_inode;
3423 } else {
3424 /* clear the extent format for fast symlink */
3425 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
3426 memcpy((char *)&EXT4_I(inode)->i_data, disk_link.name,
3427 disk_link.len);
3428 inode->i_size = disk_link.len - 1;
3429 EXT4_I(inode)->i_disksize = inode->i_size;
3430 }
3431 err = ext4_add_nondir(handle, dentry, &inode);
3432 if (handle)
3433 ext4_journal_stop(handle);
3434 iput(inode);
3435 goto out_retry;
3436
3437 err_drop_inode:
3438 clear_nlink(inode);
3439 ext4_mark_inode_dirty(handle, inode);
3440 ext4_orphan_add(handle, inode);
3441 unlock_new_inode(inode);
3442 if (handle)
3443 ext4_journal_stop(handle);
3444 iput(inode);
3445 out_retry:
3446 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
3447 goto retry;
3448 if (disk_link.name != (unsigned char *)symname)
3449 kfree(disk_link.name);
3450 return err;
3451 }
3452
3453 int __ext4_link(struct inode *dir, struct inode *inode, struct dentry *dentry)
3454 {
3455 handle_t *handle;
3456 int err, retries = 0;
3457 retry:
3458 handle = ext4_journal_start(dir, EXT4_HT_DIR,
3459 (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3460 EXT4_INDEX_EXTRA_TRANS_BLOCKS) + 1);
3461 if (IS_ERR(handle))
3462 return PTR_ERR(handle);
3463
3464 if (IS_DIRSYNC(dir))
3465 ext4_handle_sync(handle);
3466
3467 inode_set_ctime_current(inode);
3468 ext4_inc_count(inode);
3469 ihold(inode);
3470
3471 err = ext4_add_entry(handle, dentry, inode);
3472 if (!err) {
3473 err = ext4_mark_inode_dirty(handle, inode);
3474 /* this can happen only for tmpfile being
3475 * linked the first time
3476 */
3477 if (inode->i_nlink == 1)
3478 ext4_orphan_del(handle, inode);
3479 d_instantiate(dentry, inode);
3480 ext4_fc_track_link(handle, dentry);
3481 } else {
3482 drop_nlink(inode);
3483 iput(inode);
3484 }
3485 ext4_journal_stop(handle);
3486 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
3487 goto retry;
3488 return err;
3489 }
3490
3491 static int ext4_link(struct dentry *old_dentry,
3492 struct inode *dir, struct dentry *dentry)
3493 {
3494 struct inode *inode = d_inode(old_dentry);
3495 int err;
3496
3497 if (inode->i_nlink >= EXT4_LINK_MAX)
3498 return -EMLINK;
3499
3500 err = fscrypt_prepare_link(old_dentry, dir, dentry);
3501 if (err)
3502 return err;
3503
3504 if ((ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT)) &&
3505 (!projid_eq(EXT4_I(dir)->i_projid,
3506 EXT4_I(old_dentry->d_inode)->i_projid)))
3507 return -EXDEV;
3508
3509 err = dquot_initialize(dir);
3510 if (err)
3511 return err;
3512 return __ext4_link(dir, inode, dentry);
3513 }
3514
3515 /*
3516 * Try to find buffer head where contains the parent block.
3517 * It should be the inode block if it is inlined or the 1st block
3518 * if it is a normal dir.
3519 */
3520 static struct buffer_head *ext4_get_first_dir_block(handle_t *handle,
3521 struct inode *inode,
3522 int *retval,
3523 struct ext4_dir_entry_2 **parent_de,
3524 int *inlined)
3525 {
3526 struct buffer_head *bh;
3527
3528 if (!ext4_has_inline_data(inode)) {
3529 struct ext4_dir_entry_2 *de;
3530 unsigned int offset;
3531
3532 bh = ext4_read_dirblock(inode, 0, EITHER);
3533 if (IS_ERR(bh)) {
3534 *retval = PTR_ERR(bh);
3535 return NULL;
3536 }
3537
3538 de = (struct ext4_dir_entry_2 *) bh->b_data;
3539 if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data,
3540 bh->b_size, 0) ||
3541 le32_to_cpu(de->inode) != inode->i_ino ||
3542 strcmp(".", de->name)) {
3543 EXT4_ERROR_INODE(inode, "directory missing '.'");
3544 brelse(bh);
3545 *retval = -EFSCORRUPTED;
3546 return NULL;
3547 }
3548 offset = ext4_rec_len_from_disk(de->rec_len,
3549 inode->i_sb->s_blocksize);
3550 de = ext4_next_entry(de, inode->i_sb->s_blocksize);
3551 if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data,
3552 bh->b_size, offset) ||
3553 le32_to_cpu(de->inode) == 0 || strcmp("..", de->name)) {
3554 EXT4_ERROR_INODE(inode, "directory missing '..'");
3555 brelse(bh);
3556 *retval = -EFSCORRUPTED;
3557 return NULL;
3558 }
3559 *parent_de = de;
3560
3561 return bh;
3562 }
3563
3564 *inlined = 1;
3565 return ext4_get_first_inline_block(inode, parent_de, retval);
3566 }
3567
3568 struct ext4_renament {
3569 struct inode *dir;
3570 struct dentry *dentry;
3571 struct inode *inode;
3572 bool is_dir;
3573 int dir_nlink_delta;
3574
3575 /* entry for "dentry" */
3576 struct buffer_head *bh;
3577 struct ext4_dir_entry_2 *de;
3578 int inlined;
3579
3580 /* entry for ".." in inode if it's a directory */
3581 struct buffer_head *dir_bh;
3582 struct ext4_dir_entry_2 *parent_de;
3583 int dir_inlined;
3584 };
3585
3586 static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent, bool is_cross)
3587 {
3588 int retval;
3589
3590 ent->is_dir = true;
3591 if (!is_cross)
3592 return 0;
3593
3594 ent->dir_bh = ext4_get_first_dir_block(handle, ent->inode,
3595 &retval, &ent->parent_de,
3596 &ent->dir_inlined);
3597 if (!ent->dir_bh)
3598 return retval;
3599 if (le32_to_cpu(ent->parent_de->inode) != ent->dir->i_ino)
3600 return -EFSCORRUPTED;
3601 BUFFER_TRACE(ent->dir_bh, "get_write_access");
3602 return ext4_journal_get_write_access(handle, ent->dir->i_sb,
3603 ent->dir_bh, EXT4_JTR_NONE);
3604 }
3605
3606 static int ext4_rename_dir_finish(handle_t *handle, struct ext4_renament *ent,
3607 unsigned dir_ino)
3608 {
3609 int retval;
3610
3611 if (!ent->dir_bh)
3612 return 0;
3613
3614 ent->parent_de->inode = cpu_to_le32(dir_ino);
3615 BUFFER_TRACE(ent->dir_bh, "call ext4_handle_dirty_metadata");
3616 if (!ent->dir_inlined) {
3617 if (is_dx(ent->inode)) {
3618 retval = ext4_handle_dirty_dx_node(handle,
3619 ent->inode,
3620 ent->dir_bh);
3621 } else {
3622 retval = ext4_handle_dirty_dirblock(handle, ent->inode,
3623 ent->dir_bh);
3624 }
3625 } else {
3626 retval = ext4_mark_inode_dirty(handle, ent->inode);
3627 }
3628 if (retval) {
3629 ext4_std_error(ent->dir->i_sb, retval);
3630 return retval;
3631 }
3632 return 0;
3633 }
3634
3635 static int ext4_setent(handle_t *handle, struct ext4_renament *ent,
3636 unsigned ino, unsigned file_type)
3637 {
3638 int retval, retval2;
3639
3640 BUFFER_TRACE(ent->bh, "get write access");
3641 retval = ext4_journal_get_write_access(handle, ent->dir->i_sb, ent->bh,
3642 EXT4_JTR_NONE);
3643 if (retval)
3644 return retval;
3645 ent->de->inode = cpu_to_le32(ino);
3646 if (ext4_has_feature_filetype(ent->dir->i_sb))
3647 ent->de->file_type = file_type;
3648 inode_inc_iversion(ent->dir);
3649 inode_set_mtime_to_ts(ent->dir, inode_set_ctime_current(ent->dir));
3650 retval = ext4_mark_inode_dirty(handle, ent->dir);
3651 BUFFER_TRACE(ent->bh, "call ext4_handle_dirty_metadata");
3652 if (!ent->inlined) {
3653 retval2 = ext4_handle_dirty_dirblock(handle, ent->dir, ent->bh);
3654 if (unlikely(retval2)) {
3655 ext4_std_error(ent->dir->i_sb, retval2);
3656 return retval2;
3657 }
3658 }
3659 return retval;
3660 }
3661
3662 static void ext4_resetent(handle_t *handle, struct ext4_renament *ent,
3663 unsigned ino, unsigned file_type)
3664 {
3665 struct ext4_renament old = *ent;
3666 int retval = 0;
3667
3668 /*
3669 * old->de could have moved from under us during make indexed dir,
3670 * so the old->de may no longer valid and need to find it again
3671 * before reset old inode info.
3672 */
3673 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de,
3674 &old.inlined);
3675 if (IS_ERR(old.bh))
3676 retval = PTR_ERR(old.bh);
3677 if (!old.bh)
3678 retval = -ENOENT;
3679 if (retval) {
3680 ext4_std_error(old.dir->i_sb, retval);
3681 return;
3682 }
3683
3684 ext4_setent(handle, &old, ino, file_type);
3685 brelse(old.bh);
3686 }
3687
3688 static int ext4_find_delete_entry(handle_t *handle, struct inode *dir,
3689 const struct qstr *d_name)
3690 {
3691 int retval = -ENOENT;
3692 struct buffer_head *bh;
3693 struct ext4_dir_entry_2 *de;
3694
3695 bh = ext4_find_entry(dir, d_name, &de, NULL);
3696 if (IS_ERR(bh))
3697 return PTR_ERR(bh);
3698 if (bh) {
3699 retval = ext4_delete_entry(handle, dir, de, bh);
3700 brelse(bh);
3701 }
3702 return retval;
3703 }
3704
3705 static void ext4_rename_delete(handle_t *handle, struct ext4_renament *ent,
3706 int force_reread)
3707 {
3708 int retval;
3709 /*
3710 * ent->de could have moved from under us during htree split, so make
3711 * sure that we are deleting the right entry. We might also be pointing
3712 * to a stale entry in the unused part of ent->bh so just checking inum
3713 * and the name isn't enough.
3714 */
3715 if (le32_to_cpu(ent->de->inode) != ent->inode->i_ino ||
3716 ent->de->name_len != ent->dentry->d_name.len ||
3717 strncmp(ent->de->name, ent->dentry->d_name.name,
3718 ent->de->name_len) ||
3719 force_reread) {
3720 retval = ext4_find_delete_entry(handle, ent->dir,
3721 &ent->dentry->d_name);
3722 } else {
3723 retval = ext4_delete_entry(handle, ent->dir, ent->de, ent->bh);
3724 if (retval == -ENOENT) {
3725 retval = ext4_find_delete_entry(handle, ent->dir,
3726 &ent->dentry->d_name);
3727 }
3728 }
3729
3730 if (retval) {
3731 ext4_warning_inode(ent->dir,
3732 "Deleting old file: nlink %d, error=%d",
3733 ent->dir->i_nlink, retval);
3734 }
3735 }
3736
3737 static void ext4_update_dir_count(handle_t *handle, struct ext4_renament *ent)
3738 {
3739 if (ent->dir_nlink_delta) {
3740 if (ent->dir_nlink_delta == -1)
3741 ext4_dec_count(ent->dir);
3742 else
3743 ext4_inc_count(ent->dir);
3744 ext4_mark_inode_dirty(handle, ent->dir);
3745 }
3746 }
3747
3748 static struct inode *ext4_whiteout_for_rename(struct mnt_idmap *idmap,
3749 struct ext4_renament *ent,
3750 int credits, handle_t **h)
3751 {
3752 struct inode *wh;
3753 handle_t *handle;
3754 int retries = 0;
3755
3756 /*
3757 * for inode block, sb block, group summaries,
3758 * and inode bitmap
3759 */
3760 credits += (EXT4_MAXQUOTAS_TRANS_BLOCKS(ent->dir->i_sb) +
3761 EXT4_XATTR_TRANS_BLOCKS + 4);
3762 retry:
3763 wh = ext4_new_inode_start_handle(idmap, ent->dir,
3764 S_IFCHR | WHITEOUT_MODE,
3765 &ent->dentry->d_name, 0, NULL,
3766 EXT4_HT_DIR, credits);
3767
3768 handle = ext4_journal_current_handle();
3769 if (IS_ERR(wh)) {
3770 if (handle)
3771 ext4_journal_stop(handle);
3772 if (PTR_ERR(wh) == -ENOSPC &&
3773 ext4_should_retry_alloc(ent->dir->i_sb, &retries))
3774 goto retry;
3775 } else {
3776 *h = handle;
3777 init_special_inode(wh, wh->i_mode, WHITEOUT_DEV);
3778 wh->i_op = &ext4_special_inode_operations;
3779 }
3780 return wh;
3781 }
3782
3783 /*
3784 * Anybody can rename anything with this: the permission checks are left to the
3785 * higher-level routines.
3786 *
3787 * n.b. old_{dentry,inode) refers to the source dentry/inode
3788 * while new_{dentry,inode) refers to the destination dentry/inode
3789 * This comes from rename(const char *oldpath, const char *newpath)
3790 */
3791 static int ext4_rename(struct mnt_idmap *idmap, struct inode *old_dir,
3792 struct dentry *old_dentry, struct inode *new_dir,
3793 struct dentry *new_dentry, unsigned int flags)
3794 {
3795 handle_t *handle = NULL;
3796 struct ext4_renament old = {
3797 .dir = old_dir,
3798 .dentry = old_dentry,
3799 .inode = d_inode(old_dentry),
3800 };
3801 struct ext4_renament new = {
3802 .dir = new_dir,
3803 .dentry = new_dentry,
3804 .inode = d_inode(new_dentry),
3805 };
3806 int force_reread;
3807 int retval;
3808 struct inode *whiteout = NULL;
3809 int credits;
3810 u8 old_file_type;
3811
3812 if (new.inode && new.inode->i_nlink == 0) {
3813 EXT4_ERROR_INODE(new.inode,
3814 "target of rename is already freed");
3815 return -EFSCORRUPTED;
3816 }
3817
3818 if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT)) &&
3819 (!projid_eq(EXT4_I(new_dir)->i_projid,
3820 EXT4_I(old_dentry->d_inode)->i_projid)))
3821 return -EXDEV;
3822
3823 retval = dquot_initialize(old.dir);
3824 if (retval)
3825 return retval;
3826 retval = dquot_initialize(old.inode);
3827 if (retval)
3828 return retval;
3829 retval = dquot_initialize(new.dir);
3830 if (retval)
3831 return retval;
3832
3833 /* Initialize quotas before so that eventual writes go
3834 * in separate transaction */
3835 if (new.inode) {
3836 retval = dquot_initialize(new.inode);
3837 if (retval)
3838 return retval;
3839 }
3840
3841 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de,
3842 &old.inlined);
3843 if (IS_ERR(old.bh))
3844 return PTR_ERR(old.bh);
3845
3846 /*
3847 * Check for inode number is _not_ due to possible IO errors.
3848 * We might rmdir the source, keep it as pwd of some process
3849 * and merrily kill the link to whatever was created under the
3850 * same name. Goodbye sticky bit ;-<
3851 */
3852 retval = -ENOENT;
3853 if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3854 goto release_bh;
3855
3856 new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
3857 &new.de, &new.inlined);
3858 if (IS_ERR(new.bh)) {
3859 retval = PTR_ERR(new.bh);
3860 new.bh = NULL;
3861 goto release_bh;
3862 }
3863 if (new.bh) {
3864 if (!new.inode) {
3865 brelse(new.bh);
3866 new.bh = NULL;
3867 }
3868 }
3869 if (new.inode && !test_opt(new.dir->i_sb, NO_AUTO_DA_ALLOC))
3870 ext4_alloc_da_blocks(old.inode);
3871
3872 credits = (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3873 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
3874 if (!(flags & RENAME_WHITEOUT)) {
3875 handle = ext4_journal_start(old.dir, EXT4_HT_DIR, credits);
3876 if (IS_ERR(handle)) {
3877 retval = PTR_ERR(handle);
3878 goto release_bh;
3879 }
3880 } else {
3881 whiteout = ext4_whiteout_for_rename(idmap, &old, credits, &handle);
3882 if (IS_ERR(whiteout)) {
3883 retval = PTR_ERR(whiteout);
3884 goto release_bh;
3885 }
3886 }
3887
3888 old_file_type = old.de->file_type;
3889 if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3890 ext4_handle_sync(handle);
3891
3892 if (S_ISDIR(old.inode->i_mode)) {
3893 if (new.inode) {
3894 retval = -ENOTEMPTY;
3895 if (!ext4_empty_dir(new.inode))
3896 goto end_rename;
3897 } else {
3898 retval = -EMLINK;
3899 if (new.dir != old.dir && EXT4_DIR_LINK_MAX(new.dir))
3900 goto end_rename;
3901 }
3902 retval = ext4_rename_dir_prepare(handle, &old, new.dir != old.dir);
3903 if (retval)
3904 goto end_rename;
3905 }
3906 /*
3907 * If we're renaming a file within an inline_data dir and adding or
3908 * setting the new dirent causes a conversion from inline_data to
3909 * extents/blockmap, we need to force the dirent delete code to
3910 * re-read the directory, or else we end up trying to delete a dirent
3911 * from what is now the extent tree root (or a block map).
3912 */
3913 force_reread = (new.dir->i_ino == old.dir->i_ino &&
3914 ext4_test_inode_flag(new.dir, EXT4_INODE_INLINE_DATA));
3915
3916 if (whiteout) {
3917 /*
3918 * Do this before adding a new entry, so the old entry is sure
3919 * to be still pointing to the valid old entry.
3920 */
3921 retval = ext4_setent(handle, &old, whiteout->i_ino,
3922 EXT4_FT_CHRDEV);
3923 if (retval)
3924 goto end_rename;
3925 retval = ext4_mark_inode_dirty(handle, whiteout);
3926 if (unlikely(retval))
3927 goto end_rename;
3928
3929 }
3930 if (!new.bh) {
3931 retval = ext4_add_entry(handle, new.dentry, old.inode);
3932 if (retval)
3933 goto end_rename;
3934 } else {
3935 retval = ext4_setent(handle, &new,
3936 old.inode->i_ino, old_file_type);
3937 if (retval)
3938 goto end_rename;
3939 }
3940 if (force_reread)
3941 force_reread = !ext4_test_inode_flag(new.dir,
3942 EXT4_INODE_INLINE_DATA);
3943
3944 /*
3945 * Like most other Unix systems, set the ctime for inodes on a
3946 * rename.
3947 */
3948 inode_set_ctime_current(old.inode);
3949 retval = ext4_mark_inode_dirty(handle, old.inode);
3950 if (unlikely(retval))
3951 goto end_rename;
3952
3953 if (!whiteout) {
3954 /*
3955 * ok, that's it
3956 */
3957 ext4_rename_delete(handle, &old, force_reread);
3958 }
3959
3960 if (new.inode) {
3961 ext4_dec_count(new.inode);
3962 inode_set_ctime_current(new.inode);
3963 }
3964 inode_set_mtime_to_ts(old.dir, inode_set_ctime_current(old.dir));
3965 ext4_update_dx_flag(old.dir);
3966 if (old.is_dir) {
3967 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
3968 if (retval)
3969 goto end_rename;
3970
3971 ext4_dec_count(old.dir);
3972 if (new.inode) {
3973 /* checked ext4_empty_dir above, can't have another
3974 * parent, ext4_dec_count() won't work for many-linked
3975 * dirs */
3976 clear_nlink(new.inode);
3977 } else {
3978 ext4_inc_count(new.dir);
3979 ext4_update_dx_flag(new.dir);
3980 retval = ext4_mark_inode_dirty(handle, new.dir);
3981 if (unlikely(retval))
3982 goto end_rename;
3983 }
3984 }
3985 retval = ext4_mark_inode_dirty(handle, old.dir);
3986 if (unlikely(retval))
3987 goto end_rename;
3988
3989 if (old.is_dir) {
3990 /*
3991 * We disable fast commits here that's because the
3992 * replay code is not yet capable of changing dot dot
3993 * dirents in directories.
3994 */
3995 ext4_fc_mark_ineligible(old.inode->i_sb,
3996 EXT4_FC_REASON_RENAME_DIR, handle);
3997 } else {
3998 struct super_block *sb = old.inode->i_sb;
3999
4000 if (new.inode)
4001 ext4_fc_track_unlink(handle, new.dentry);
4002 if (test_opt2(sb, JOURNAL_FAST_COMMIT) &&
4003 !(EXT4_SB(sb)->s_mount_state & EXT4_FC_REPLAY) &&
4004 !(ext4_test_mount_flag(sb, EXT4_MF_FC_INELIGIBLE))) {
4005 __ext4_fc_track_link(handle, old.inode, new.dentry);
4006 __ext4_fc_track_unlink(handle, old.inode, old.dentry);
4007 if (whiteout)
4008 __ext4_fc_track_create(handle, whiteout,
4009 old.dentry);
4010 }
4011 }
4012
4013 if (new.inode) {
4014 retval = ext4_mark_inode_dirty(handle, new.inode);
4015 if (unlikely(retval))
4016 goto end_rename;
4017 if (!new.inode->i_nlink)
4018 ext4_orphan_add(handle, new.inode);
4019 }
4020 retval = 0;
4021
4022 end_rename:
4023 if (whiteout) {
4024 if (retval) {
4025 ext4_resetent(handle, &old,
4026 old.inode->i_ino, old_file_type);
4027 drop_nlink(whiteout);
4028 ext4_mark_inode_dirty(handle, whiteout);
4029 ext4_orphan_add(handle, whiteout);
4030 }
4031 unlock_new_inode(whiteout);
4032 ext4_journal_stop(handle);
4033 iput(whiteout);
4034 } else {
4035 ext4_journal_stop(handle);
4036 }
4037 release_bh:
4038 brelse(old.dir_bh);
4039 brelse(old.bh);
4040 brelse(new.bh);
4041
4042 return retval;
4043 }
4044
4045 static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
4046 struct inode *new_dir, struct dentry *new_dentry)
4047 {
4048 handle_t *handle = NULL;
4049 struct ext4_renament old = {
4050 .dir = old_dir,
4051 .dentry = old_dentry,
4052 .inode = d_inode(old_dentry),
4053 };
4054 struct ext4_renament new = {
4055 .dir = new_dir,
4056 .dentry = new_dentry,
4057 .inode = d_inode(new_dentry),
4058 };
4059 u8 new_file_type;
4060 int retval;
4061
4062 if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT) &&
4063 !projid_eq(EXT4_I(new_dir)->i_projid,
4064 EXT4_I(old_dentry->d_inode)->i_projid)) ||
4065 (ext4_test_inode_flag(old_dir, EXT4_INODE_PROJINHERIT) &&
4066 !projid_eq(EXT4_I(old_dir)->i_projid,
4067 EXT4_I(new_dentry->d_inode)->i_projid)))
4068 return -EXDEV;
4069
4070 retval = dquot_initialize(old.dir);
4071 if (retval)
4072 return retval;
4073 retval = dquot_initialize(new.dir);
4074 if (retval)
4075 return retval;
4076
4077 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name,
4078 &old.de, &old.inlined);
4079 if (IS_ERR(old.bh))
4080 return PTR_ERR(old.bh);
4081 /*
4082 * Check for inode number is _not_ due to possible IO errors.
4083 * We might rmdir the source, keep it as pwd of some process
4084 * and merrily kill the link to whatever was created under the
4085 * same name. Goodbye sticky bit ;-<
4086 */
4087 retval = -ENOENT;
4088 if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
4089 goto end_rename;
4090
4091 new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
4092 &new.de, &new.inlined);
4093 if (IS_ERR(new.bh)) {
4094 retval = PTR_ERR(new.bh);
4095 new.bh = NULL;
4096 goto end_rename;
4097 }
4098
4099 /* RENAME_EXCHANGE case: old *and* new must both exist */
4100 if (!new.bh || le32_to_cpu(new.de->inode) != new.inode->i_ino)
4101 goto end_rename;
4102
4103 handle = ext4_journal_start(old.dir, EXT4_HT_DIR,
4104 (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
4105 2 * EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2));
4106 if (IS_ERR(handle)) {
4107 retval = PTR_ERR(handle);
4108 handle = NULL;
4109 goto end_rename;
4110 }
4111
4112 if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
4113 ext4_handle_sync(handle);
4114
4115 if (S_ISDIR(old.inode->i_mode)) {
4116 retval = ext4_rename_dir_prepare(handle, &old, new.dir != old.dir);
4117 if (retval)
4118 goto end_rename;
4119 }
4120 if (S_ISDIR(new.inode->i_mode)) {
4121 retval = ext4_rename_dir_prepare(handle, &new, new.dir != old.dir);
4122 if (retval)
4123 goto end_rename;
4124 }
4125
4126 /*
4127 * Other than the special case of overwriting a directory, parents'
4128 * nlink only needs to be modified if this is a cross directory rename.
4129 */
4130 if (old.dir != new.dir && old.is_dir != new.is_dir) {
4131 old.dir_nlink_delta = old.is_dir ? -1 : 1;
4132 new.dir_nlink_delta = -old.dir_nlink_delta;
4133 retval = -EMLINK;
4134 if ((old.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(old.dir)) ||
4135 (new.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(new.dir)))
4136 goto end_rename;
4137 }
4138
4139 new_file_type = new.de->file_type;
4140 retval = ext4_setent(handle, &new, old.inode->i_ino, old.de->file_type);
4141 if (retval)
4142 goto end_rename;
4143
4144 retval = ext4_setent(handle, &old, new.inode->i_ino, new_file_type);
4145 if (retval)
4146 goto end_rename;
4147
4148 /*
4149 * Like most other Unix systems, set the ctime for inodes on a
4150 * rename.
4151 */
4152 inode_set_ctime_current(old.inode);
4153 inode_set_ctime_current(new.inode);
4154 retval = ext4_mark_inode_dirty(handle, old.inode);
4155 if (unlikely(retval))
4156 goto end_rename;
4157 retval = ext4_mark_inode_dirty(handle, new.inode);
4158 if (unlikely(retval))
4159 goto end_rename;
4160 ext4_fc_mark_ineligible(new.inode->i_sb,
4161 EXT4_FC_REASON_CROSS_RENAME, handle);
4162 if (old.dir_bh) {
4163 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
4164 if (retval)
4165 goto end_rename;
4166 }
4167 if (new.dir_bh) {
4168 retval = ext4_rename_dir_finish(handle, &new, old.dir->i_ino);
4169 if (retval)
4170 goto end_rename;
4171 }
4172 ext4_update_dir_count(handle, &old);
4173 ext4_update_dir_count(handle, &new);
4174 retval = 0;
4175
4176 end_rename:
4177 brelse(old.dir_bh);
4178 brelse(new.dir_bh);
4179 brelse(old.bh);
4180 brelse(new.bh);
4181 if (handle)
4182 ext4_journal_stop(handle);
4183 return retval;
4184 }
4185
4186 static int ext4_rename2(struct mnt_idmap *idmap,
4187 struct inode *old_dir, struct dentry *old_dentry,
4188 struct inode *new_dir, struct dentry *new_dentry,
4189 unsigned int flags)
4190 {
4191 int err;
4192
4193 if (unlikely(ext4_forced_shutdown(old_dir->i_sb)))
4194 return -EIO;
4195
4196 if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
4197 return -EINVAL;
4198
4199 err = fscrypt_prepare_rename(old_dir, old_dentry, new_dir, new_dentry,
4200 flags);
4201 if (err)
4202 return err;
4203
4204 if (flags & RENAME_EXCHANGE) {
4205 return ext4_cross_rename(old_dir, old_dentry,
4206 new_dir, new_dentry);
4207 }
4208
4209 return ext4_rename(idmap, old_dir, old_dentry, new_dir, new_dentry, flags);
4210 }
4211
4212 /*
4213 * directories can handle most operations...
4214 */
4215 const struct inode_operations ext4_dir_inode_operations = {
4216 .create = ext4_create,
4217 .lookup = ext4_lookup,
4218 .link = ext4_link,
4219 .unlink = ext4_unlink,
4220 .symlink = ext4_symlink,
4221 .mkdir = ext4_mkdir,
4222 .rmdir = ext4_rmdir,
4223 .mknod = ext4_mknod,
4224 .tmpfile = ext4_tmpfile,
4225 .rename = ext4_rename2,
4226 .setattr = ext4_setattr,
4227 .getattr = ext4_getattr,
4228 .listxattr = ext4_listxattr,
4229 .get_inode_acl = ext4_get_acl,
4230 .set_acl = ext4_set_acl,
4231 .fiemap = ext4_fiemap,
4232 .fileattr_get = ext4_fileattr_get,
4233 .fileattr_set = ext4_fileattr_set,
4234 };
4235
4236 const struct inode_operations ext4_special_inode_operations = {
4237 .setattr = ext4_setattr,
4238 .getattr = ext4_getattr,
4239 .listxattr = ext4_listxattr,
4240 .get_inode_acl = ext4_get_acl,
4241 .set_acl = ext4_set_acl,
4242 };
4243
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