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
ext4_append(handle_t * handle,struct inode * inode,ext4_lblk_t * block)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
__ext4_read_dirblock(struct inode * inode,ext4_lblk_t block,dirblock_type_t type,const char * func,unsigned int line)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_feature_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 struct buffer_head * ext4_dx_find_entry(struct inode *dir,
295 struct ext4_filename *fname,
296 struct ext4_dir_entry_2 **res_dir);
297 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
298 struct inode *dir, struct inode *inode);
299
300 /* checksumming functions */
ext4_initialize_dirent_tail(struct buffer_head * bh,unsigned int blocksize)301 void ext4_initialize_dirent_tail(struct buffer_head *bh,
302 unsigned int blocksize)
303 {
304 struct ext4_dir_entry_tail *t = EXT4_DIRENT_TAIL(bh->b_data, blocksize);
305
306 memset(t, 0, sizeof(struct ext4_dir_entry_tail));
307 t->det_rec_len = ext4_rec_len_to_disk(
308 sizeof(struct ext4_dir_entry_tail), blocksize);
309 t->det_reserved_ft = EXT4_FT_DIR_CSUM;
310 }
311
312 /* Walk through a dirent block to find a checksum "dirent" at the tail */
get_dirent_tail(struct inode * inode,struct buffer_head * bh)313 static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode,
314 struct buffer_head *bh)
315 {
316 struct ext4_dir_entry_tail *t;
317 int blocksize = EXT4_BLOCK_SIZE(inode->i_sb);
318
319 #ifdef PARANOID
320 struct ext4_dir_entry *d, *top;
321
322 d = (struct ext4_dir_entry *)bh->b_data;
323 top = (struct ext4_dir_entry *)(bh->b_data +
324 (blocksize - sizeof(struct ext4_dir_entry_tail)));
325 while (d < top && ext4_rec_len_from_disk(d->rec_len, blocksize))
326 d = (struct ext4_dir_entry *)(((void *)d) +
327 ext4_rec_len_from_disk(d->rec_len, blocksize));
328
329 if (d != top)
330 return NULL;
331
332 t = (struct ext4_dir_entry_tail *)d;
333 #else
334 t = EXT4_DIRENT_TAIL(bh->b_data, EXT4_BLOCK_SIZE(inode->i_sb));
335 #endif
336
337 if (t->det_reserved_zero1 ||
338 (ext4_rec_len_from_disk(t->det_rec_len, blocksize) !=
339 sizeof(struct ext4_dir_entry_tail)) ||
340 t->det_reserved_zero2 ||
341 t->det_reserved_ft != EXT4_FT_DIR_CSUM)
342 return NULL;
343
344 return t;
345 }
346
ext4_dirblock_csum(struct inode * inode,void * dirent,int size)347 static __le32 ext4_dirblock_csum(struct inode *inode, void *dirent, int size)
348 {
349 struct ext4_inode_info *ei = EXT4_I(inode);
350 __u32 csum;
351
352 csum = ext4_chksum(ei->i_csum_seed, (__u8 *)dirent, size);
353 return cpu_to_le32(csum);
354 }
355
356 #define warn_no_space_for_csum(inode) \
357 __warn_no_space_for_csum((inode), __func__, __LINE__)
358
__warn_no_space_for_csum(struct inode * inode,const char * func,unsigned int line)359 static void __warn_no_space_for_csum(struct inode *inode, const char *func,
360 unsigned int line)
361 {
362 __ext4_warning_inode(inode, func, line,
363 "No space for directory leaf checksum. Please run e2fsck -D.");
364 }
365
ext4_dirblock_csum_verify(struct inode * inode,struct buffer_head * bh)366 int ext4_dirblock_csum_verify(struct inode *inode, struct buffer_head *bh)
367 {
368 struct ext4_dir_entry_tail *t;
369
370 if (!ext4_has_feature_metadata_csum(inode->i_sb))
371 return 1;
372
373 t = get_dirent_tail(inode, bh);
374 if (!t) {
375 warn_no_space_for_csum(inode);
376 return 0;
377 }
378
379 if (t->det_checksum != ext4_dirblock_csum(inode, bh->b_data,
380 (char *)t - bh->b_data))
381 return 0;
382
383 return 1;
384 }
385
ext4_dirblock_csum_set(struct inode * inode,struct buffer_head * bh)386 static void ext4_dirblock_csum_set(struct inode *inode,
387 struct buffer_head *bh)
388 {
389 struct ext4_dir_entry_tail *t;
390
391 if (!ext4_has_feature_metadata_csum(inode->i_sb))
392 return;
393
394 t = get_dirent_tail(inode, bh);
395 if (!t) {
396 warn_no_space_for_csum(inode);
397 return;
398 }
399
400 t->det_checksum = ext4_dirblock_csum(inode, bh->b_data,
401 (char *)t - bh->b_data);
402 }
403
ext4_handle_dirty_dirblock(handle_t * handle,struct inode * inode,struct buffer_head * bh)404 int ext4_handle_dirty_dirblock(handle_t *handle,
405 struct inode *inode,
406 struct buffer_head *bh)
407 {
408 ext4_dirblock_csum_set(inode, bh);
409 return ext4_handle_dirty_metadata(handle, inode, bh);
410 }
411
get_dx_countlimit(struct inode * inode,struct ext4_dir_entry * dirent,int * offset)412 static struct dx_countlimit *get_dx_countlimit(struct inode *inode,
413 struct ext4_dir_entry *dirent,
414 int *offset)
415 {
416 struct ext4_dir_entry *dp;
417 struct dx_root_info *root;
418 int count_offset;
419 int blocksize = EXT4_BLOCK_SIZE(inode->i_sb);
420 unsigned int rlen = ext4_rec_len_from_disk(dirent->rec_len, blocksize);
421
422 if (rlen == blocksize)
423 count_offset = 8;
424 else if (rlen == 12) {
425 dp = (struct ext4_dir_entry *)(((void *)dirent) + 12);
426 if (ext4_rec_len_from_disk(dp->rec_len, blocksize) != blocksize - 12)
427 return NULL;
428 root = (struct dx_root_info *)(((void *)dp + 12));
429 if (root->reserved_zero ||
430 root->info_length != sizeof(struct dx_root_info))
431 return NULL;
432 count_offset = 32;
433 } else
434 return NULL;
435
436 if (offset)
437 *offset = count_offset;
438 return (struct dx_countlimit *)(((void *)dirent) + count_offset);
439 }
440
ext4_dx_csum(struct inode * inode,struct ext4_dir_entry * dirent,int count_offset,int count,struct dx_tail * t)441 static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent,
442 int count_offset, int count, struct dx_tail *t)
443 {
444 struct ext4_inode_info *ei = EXT4_I(inode);
445 __u32 csum;
446 int size;
447 __u32 dummy_csum = 0;
448 int offset = offsetof(struct dx_tail, dt_checksum);
449
450 size = count_offset + (count * sizeof(struct dx_entry));
451 csum = ext4_chksum(ei->i_csum_seed, (__u8 *)dirent, size);
452 csum = ext4_chksum(csum, (__u8 *)t, offset);
453 csum = ext4_chksum(csum, (__u8 *)&dummy_csum, sizeof(dummy_csum));
454
455 return cpu_to_le32(csum);
456 }
457
ext4_dx_csum_verify(struct inode * inode,struct ext4_dir_entry * dirent)458 static int ext4_dx_csum_verify(struct inode *inode,
459 struct ext4_dir_entry *dirent)
460 {
461 struct dx_countlimit *c;
462 struct dx_tail *t;
463 int count_offset, limit, count;
464
465 if (!ext4_has_feature_metadata_csum(inode->i_sb))
466 return 1;
467
468 c = get_dx_countlimit(inode, dirent, &count_offset);
469 if (!c) {
470 EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D.");
471 return 0;
472 }
473 limit = le16_to_cpu(c->limit);
474 count = le16_to_cpu(c->count);
475 if (count_offset + (limit * sizeof(struct dx_entry)) >
476 EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
477 warn_no_space_for_csum(inode);
478 return 0;
479 }
480 t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
481
482 if (t->dt_checksum != ext4_dx_csum(inode, dirent, count_offset,
483 count, t))
484 return 0;
485 return 1;
486 }
487
ext4_dx_csum_set(struct inode * inode,struct ext4_dir_entry * dirent)488 static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent)
489 {
490 struct dx_countlimit *c;
491 struct dx_tail *t;
492 int count_offset, limit, count;
493
494 if (!ext4_has_feature_metadata_csum(inode->i_sb))
495 return;
496
497 c = get_dx_countlimit(inode, dirent, &count_offset);
498 if (!c) {
499 EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D.");
500 return;
501 }
502 limit = le16_to_cpu(c->limit);
503 count = le16_to_cpu(c->count);
504 if (count_offset + (limit * sizeof(struct dx_entry)) >
505 EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
506 warn_no_space_for_csum(inode);
507 return;
508 }
509 t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
510
511 t->dt_checksum = ext4_dx_csum(inode, dirent, count_offset, count, t);
512 }
513
ext4_handle_dirty_dx_node(handle_t * handle,struct inode * inode,struct buffer_head * bh)514 static inline int ext4_handle_dirty_dx_node(handle_t *handle,
515 struct inode *inode,
516 struct buffer_head *bh)
517 {
518 ext4_dx_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
519 return ext4_handle_dirty_metadata(handle, inode, bh);
520 }
521
522 /*
523 * p is at least 6 bytes before the end of page
524 */
525 static inline struct ext4_dir_entry_2 *
ext4_next_entry(struct ext4_dir_entry_2 * p,unsigned long blocksize)526 ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
527 {
528 return (struct ext4_dir_entry_2 *)((char *)p +
529 ext4_rec_len_from_disk(p->rec_len, blocksize));
530 }
531
532 /*
533 * Future: use high four bits of block for coalesce-on-delete flags
534 * Mask them off for now.
535 */
536
dx_get_block(struct dx_entry * entry)537 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
538 {
539 return le32_to_cpu(entry->block) & 0x0fffffff;
540 }
541
dx_set_block(struct dx_entry * entry,ext4_lblk_t value)542 static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
543 {
544 entry->block = cpu_to_le32(value);
545 }
546
dx_get_hash(struct dx_entry * entry)547 static inline unsigned dx_get_hash(struct dx_entry *entry)
548 {
549 return le32_to_cpu(entry->hash);
550 }
551
dx_set_hash(struct dx_entry * entry,unsigned value)552 static inline void dx_set_hash(struct dx_entry *entry, unsigned value)
553 {
554 entry->hash = cpu_to_le32(value);
555 }
556
dx_get_count(struct dx_entry * entries)557 static inline unsigned dx_get_count(struct dx_entry *entries)
558 {
559 return le16_to_cpu(((struct dx_countlimit *) entries)->count);
560 }
561
dx_get_limit(struct dx_entry * entries)562 static inline unsigned dx_get_limit(struct dx_entry *entries)
563 {
564 return le16_to_cpu(((struct dx_countlimit *) entries)->limit);
565 }
566
dx_set_count(struct dx_entry * entries,unsigned value)567 static inline void dx_set_count(struct dx_entry *entries, unsigned value)
568 {
569 ((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
570 }
571
dx_set_limit(struct dx_entry * entries,unsigned value)572 static inline void dx_set_limit(struct dx_entry *entries, unsigned value)
573 {
574 ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
575 }
576
dx_root_limit(struct inode * dir,unsigned infosize)577 static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
578 {
579 unsigned int entry_space = dir->i_sb->s_blocksize -
580 ext4_dir_rec_len(1, NULL) -
581 ext4_dir_rec_len(2, NULL) - infosize;
582
583 if (ext4_has_feature_metadata_csum(dir->i_sb))
584 entry_space -= sizeof(struct dx_tail);
585 return entry_space / sizeof(struct dx_entry);
586 }
587
dx_node_limit(struct inode * dir)588 static inline unsigned dx_node_limit(struct inode *dir)
589 {
590 unsigned int entry_space = dir->i_sb->s_blocksize -
591 ext4_dir_rec_len(0, dir);
592
593 if (ext4_has_feature_metadata_csum(dir->i_sb))
594 entry_space -= sizeof(struct dx_tail);
595 return entry_space / sizeof(struct dx_entry);
596 }
597
598 /*
599 * Debug
600 */
601 #ifdef DX_DEBUG
dx_show_index(char * label,struct dx_entry * entries)602 static void dx_show_index(char * label, struct dx_entry *entries)
603 {
604 int i, n = dx_get_count (entries);
605 printk(KERN_DEBUG "%s index", label);
606 for (i = 0; i < n; i++) {
607 printk(KERN_CONT " %x->%lu",
608 i ? dx_get_hash(entries + i) : 0,
609 (unsigned long)dx_get_block(entries + i));
610 }
611 printk(KERN_CONT "\n");
612 }
613
614 struct stats
615 {
616 unsigned names;
617 unsigned space;
618 unsigned bcount;
619 };
620
dx_show_leaf(struct inode * dir,struct dx_hash_info * hinfo,struct ext4_dir_entry_2 * de,int size,int show_names)621 static struct stats dx_show_leaf(struct inode *dir,
622 struct dx_hash_info *hinfo,
623 struct ext4_dir_entry_2 *de,
624 int size, int show_names)
625 {
626 unsigned names = 0, space = 0;
627 char *base = (char *) de;
628 struct dx_hash_info h = *hinfo;
629
630 printk("names: ");
631 while ((char *) de < base + size)
632 {
633 if (de->inode)
634 {
635 if (show_names)
636 {
637 #ifdef CONFIG_FS_ENCRYPTION
638 int len;
639 char *name;
640 struct fscrypt_str fname_crypto_str =
641 FSTR_INIT(NULL, 0);
642 int res = 0;
643
644 name = de->name;
645 len = de->name_len;
646 if (!IS_ENCRYPTED(dir)) {
647 /* Directory is not encrypted */
648 (void) ext4fs_dirhash(dir, de->name,
649 de->name_len, &h);
650 printk("%*.s:(U)%x.%u ", len,
651 name, h.hash,
652 (unsigned) ((char *) de
653 - base));
654 } else {
655 struct fscrypt_str de_name =
656 FSTR_INIT(name, len);
657
658 /* Directory is encrypted */
659 res = fscrypt_fname_alloc_buffer(
660 len, &fname_crypto_str);
661 if (res)
662 printk(KERN_WARNING "Error "
663 "allocating crypto "
664 "buffer--skipping "
665 "crypto\n");
666 res = fscrypt_fname_disk_to_usr(dir,
667 0, 0, &de_name,
668 &fname_crypto_str);
669 if (res) {
670 printk(KERN_WARNING "Error "
671 "converting filename "
672 "from disk to usr"
673 "\n");
674 name = "??";
675 len = 2;
676 } else {
677 name = fname_crypto_str.name;
678 len = fname_crypto_str.len;
679 }
680 if (IS_CASEFOLDED(dir))
681 h.hash = EXT4_DIRENT_HASH(de);
682 else
683 (void) ext4fs_dirhash(dir,
684 de->name,
685 de->name_len, &h);
686 printk("%*.s:(E)%x.%u ", len, name,
687 h.hash, (unsigned) ((char *) de
688 - base));
689 fscrypt_fname_free_buffer(
690 &fname_crypto_str);
691 }
692 #else
693 int len = de->name_len;
694 char *name = de->name;
695 (void) ext4fs_dirhash(dir, de->name,
696 de->name_len, &h);
697 printk("%*.s:%x.%u ", len, name, h.hash,
698 (unsigned) ((char *) de - base));
699 #endif
700 }
701 space += ext4_dir_rec_len(de->name_len, dir);
702 names++;
703 }
704 de = ext4_next_entry(de, size);
705 }
706 printk(KERN_CONT "(%i)\n", names);
707 return (struct stats) { names, space, 1 };
708 }
709
dx_show_entries(struct dx_hash_info * hinfo,struct inode * dir,struct dx_entry * entries,int levels)710 struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
711 struct dx_entry *entries, int levels)
712 {
713 unsigned blocksize = dir->i_sb->s_blocksize;
714 unsigned count = dx_get_count(entries), names = 0, space = 0, i;
715 unsigned bcount = 0;
716 struct buffer_head *bh;
717 printk("%i indexed blocks...\n", count);
718 for (i = 0; i < count; i++, entries++)
719 {
720 ext4_lblk_t block = dx_get_block(entries);
721 ext4_lblk_t hash = i ? dx_get_hash(entries): 0;
722 u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
723 struct stats stats;
724 printk("%s%3u:%03u hash %8x/%8x ",levels?"":" ", i, block, hash, range);
725 bh = ext4_bread(NULL,dir, block, 0);
726 if (!bh || IS_ERR(bh))
727 continue;
728 stats = levels?
729 dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
730 dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *)
731 bh->b_data, blocksize, 0);
732 names += stats.names;
733 space += stats.space;
734 bcount += stats.bcount;
735 brelse(bh);
736 }
737 if (bcount)
738 printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n",
739 levels ? "" : " ", names, space/bcount,
740 (space/bcount)*100/blocksize);
741 return (struct stats) { names, space, bcount};
742 }
743
744 /*
745 * Linear search cross check
746 */
htree_rep_invariant_check(struct dx_entry * at,struct dx_entry * target,u32 hash,unsigned int n)747 static inline void htree_rep_invariant_check(struct dx_entry *at,
748 struct dx_entry *target,
749 u32 hash, unsigned int n)
750 {
751 while (n--) {
752 dxtrace(printk(KERN_CONT ","));
753 if (dx_get_hash(++at) > hash) {
754 at--;
755 break;
756 }
757 }
758 ASSERT(at == target - 1);
759 }
760 #else /* DX_DEBUG */
htree_rep_invariant_check(struct dx_entry * at,struct dx_entry * target,u32 hash,unsigned int n)761 static inline void htree_rep_invariant_check(struct dx_entry *at,
762 struct dx_entry *target,
763 u32 hash, unsigned int n)
764 {
765 }
766 #endif /* DX_DEBUG */
767
768 /*
769 * Probe for a directory leaf block to search.
770 *
771 * dx_probe can return ERR_BAD_DX_DIR, which means there was a format
772 * error in the directory index, and the caller should fall back to
773 * searching the directory normally. The callers of dx_probe **MUST**
774 * check for this error code, and make sure it never gets reflected
775 * back to userspace.
776 */
777 static struct dx_frame *
dx_probe(struct ext4_filename * fname,struct inode * dir,struct dx_hash_info * hinfo,struct dx_frame * frame_in)778 dx_probe(struct ext4_filename *fname, struct inode *dir,
779 struct dx_hash_info *hinfo, struct dx_frame *frame_in)
780 {
781 unsigned count, indirect, level, i;
782 struct dx_entry *at, *entries, *p, *q, *m;
783 struct dx_root *root;
784 struct dx_frame *frame = frame_in;
785 struct dx_frame *ret_err = ERR_PTR(ERR_BAD_DX_DIR);
786 u32 hash;
787 ext4_lblk_t block;
788 ext4_lblk_t blocks[EXT4_HTREE_LEVEL];
789
790 memset(frame_in, 0, EXT4_HTREE_LEVEL * sizeof(frame_in[0]));
791 frame->bh = ext4_read_dirblock(dir, 0, INDEX);
792 if (IS_ERR(frame->bh))
793 return (struct dx_frame *) frame->bh;
794
795 root = (struct dx_root *) frame->bh->b_data;
796 if (root->info.hash_version != DX_HASH_TEA &&
797 root->info.hash_version != DX_HASH_HALF_MD4 &&
798 root->info.hash_version != DX_HASH_LEGACY &&
799 root->info.hash_version != DX_HASH_SIPHASH) {
800 ext4_warning_inode(dir, "Unrecognised inode hash code %u",
801 root->info.hash_version);
802 goto fail;
803 }
804 if (ext4_hash_in_dirent(dir)) {
805 if (root->info.hash_version != DX_HASH_SIPHASH) {
806 ext4_warning_inode(dir,
807 "Hash in dirent, but hash is not SIPHASH");
808 goto fail;
809 }
810 } else {
811 if (root->info.hash_version == DX_HASH_SIPHASH) {
812 ext4_warning_inode(dir,
813 "Hash code is SIPHASH, but hash not in dirent");
814 goto fail;
815 }
816 }
817 if (fname)
818 hinfo = &fname->hinfo;
819 hinfo->hash_version = root->info.hash_version;
820 if (hinfo->hash_version <= DX_HASH_TEA)
821 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
822 hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
823 /* hash is already computed for encrypted casefolded directory */
824 if (fname && fname_name(fname) &&
825 !(IS_ENCRYPTED(dir) && IS_CASEFOLDED(dir))) {
826 int ret = ext4fs_dirhash(dir, fname_name(fname),
827 fname_len(fname), hinfo);
828 if (ret < 0) {
829 ret_err = ERR_PTR(ret);
830 goto fail;
831 }
832 }
833 hash = hinfo->hash;
834
835 if (root->info.unused_flags & 1) {
836 ext4_warning_inode(dir, "Unimplemented hash flags: %#06x",
837 root->info.unused_flags);
838 goto fail;
839 }
840
841 indirect = root->info.indirect_levels;
842 if (indirect >= ext4_dir_htree_level(dir->i_sb)) {
843 ext4_warning(dir->i_sb,
844 "Directory (ino: %lu) htree depth %#06x exceed"
845 "supported value", dir->i_ino,
846 ext4_dir_htree_level(dir->i_sb));
847 if (ext4_dir_htree_level(dir->i_sb) < EXT4_HTREE_LEVEL) {
848 ext4_warning(dir->i_sb, "Enable large directory "
849 "feature to access it");
850 }
851 goto fail;
852 }
853
854 entries = (struct dx_entry *)(((char *)&root->info) +
855 root->info.info_length);
856
857 if (dx_get_limit(entries) != dx_root_limit(dir,
858 root->info.info_length)) {
859 ext4_warning_inode(dir, "dx entry: limit %u != root limit %u",
860 dx_get_limit(entries),
861 dx_root_limit(dir, root->info.info_length));
862 goto fail;
863 }
864
865 dxtrace(printk("Look up %x", hash));
866 level = 0;
867 blocks[0] = 0;
868 while (1) {
869 count = dx_get_count(entries);
870 if (!count || count > dx_get_limit(entries)) {
871 ext4_warning_inode(dir,
872 "dx entry: count %u beyond limit %u",
873 count, dx_get_limit(entries));
874 goto fail;
875 }
876
877 p = entries + 1;
878 q = entries + count - 1;
879 while (p <= q) {
880 m = p + (q - p) / 2;
881 dxtrace(printk(KERN_CONT "."));
882 if (dx_get_hash(m) > hash)
883 q = m - 1;
884 else
885 p = m + 1;
886 }
887
888 htree_rep_invariant_check(entries, p, hash, count - 1);
889
890 at = p - 1;
891 dxtrace(printk(KERN_CONT " %x->%u\n",
892 at == entries ? 0 : dx_get_hash(at),
893 dx_get_block(at)));
894 frame->entries = entries;
895 frame->at = at;
896
897 block = dx_get_block(at);
898 for (i = 0; i <= level; i++) {
899 if (blocks[i] == block) {
900 ext4_warning_inode(dir,
901 "dx entry: tree cycle block %u points back to block %u",
902 blocks[level], block);
903 goto fail;
904 }
905 }
906 if (++level > indirect)
907 return frame;
908 blocks[level] = block;
909 frame++;
910 frame->bh = ext4_read_dirblock(dir, block, INDEX);
911 if (IS_ERR(frame->bh)) {
912 ret_err = (struct dx_frame *) frame->bh;
913 frame->bh = NULL;
914 goto fail;
915 }
916
917 entries = ((struct dx_node *) frame->bh->b_data)->entries;
918
919 if (dx_get_limit(entries) != dx_node_limit(dir)) {
920 ext4_warning_inode(dir,
921 "dx entry: limit %u != node limit %u",
922 dx_get_limit(entries), dx_node_limit(dir));
923 goto fail;
924 }
925 }
926 fail:
927 while (frame >= frame_in) {
928 brelse(frame->bh);
929 frame--;
930 }
931
932 if (ret_err == ERR_PTR(ERR_BAD_DX_DIR))
933 ext4_warning_inode(dir,
934 "Corrupt directory, running e2fsck is recommended");
935 return ret_err;
936 }
937
dx_release(struct dx_frame * frames)938 static void dx_release(struct dx_frame *frames)
939 {
940 struct dx_root_info *info;
941 int i;
942 unsigned int indirect_levels;
943
944 if (frames[0].bh == NULL)
945 return;
946
947 info = &((struct dx_root *)frames[0].bh->b_data)->info;
948 /* save local copy, "info" may be freed after brelse() */
949 indirect_levels = info->indirect_levels;
950 for (i = 0; i <= indirect_levels; i++) {
951 if (frames[i].bh == NULL)
952 break;
953 brelse(frames[i].bh);
954 frames[i].bh = NULL;
955 }
956 }
957
958 /*
959 * This function increments the frame pointer to search the next leaf
960 * block, and reads in the necessary intervening nodes if the search
961 * should be necessary. Whether or not the search is necessary is
962 * controlled by the hash parameter. If the hash value is even, then
963 * the search is only continued if the next block starts with that
964 * hash value. This is used if we are searching for a specific file.
965 *
966 * If the hash value is HASH_NB_ALWAYS, then always go to the next block.
967 *
968 * This function returns 1 if the caller should continue to search,
969 * or 0 if it should not. If there is an error reading one of the
970 * index blocks, it will a negative error code.
971 *
972 * If start_hash is non-null, it will be filled in with the starting
973 * hash of the next page.
974 */
ext4_htree_next_block(struct inode * dir,__u32 hash,struct dx_frame * frame,struct dx_frame * frames,__u32 * start_hash)975 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
976 struct dx_frame *frame,
977 struct dx_frame *frames,
978 __u32 *start_hash)
979 {
980 struct dx_frame *p;
981 struct buffer_head *bh;
982 int num_frames = 0;
983 __u32 bhash;
984
985 p = frame;
986 /*
987 * Find the next leaf page by incrementing the frame pointer.
988 * If we run out of entries in the interior node, loop around and
989 * increment pointer in the parent node. When we break out of
990 * this loop, num_frames indicates the number of interior
991 * nodes need to be read.
992 */
993 while (1) {
994 if (++(p->at) < p->entries + dx_get_count(p->entries))
995 break;
996 if (p == frames)
997 return 0;
998 num_frames++;
999 p--;
1000 }
1001
1002 /*
1003 * If the hash is 1, then continue only if the next page has a
1004 * continuation hash of any value. This is used for readdir
1005 * handling. Otherwise, check to see if the hash matches the
1006 * desired continuation hash. If it doesn't, return since
1007 * there's no point to read in the successive index pages.
1008 */
1009 bhash = dx_get_hash(p->at);
1010 if (start_hash)
1011 *start_hash = bhash;
1012 if ((hash & 1) == 0) {
1013 if ((bhash & ~1) != hash)
1014 return 0;
1015 }
1016 /*
1017 * If the hash is HASH_NB_ALWAYS, we always go to the next
1018 * block so no check is necessary
1019 */
1020 while (num_frames--) {
1021 bh = ext4_read_dirblock(dir, dx_get_block(p->at), INDEX);
1022 if (IS_ERR(bh))
1023 return PTR_ERR(bh);
1024 p++;
1025 brelse(p->bh);
1026 p->bh = bh;
1027 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
1028 }
1029 return 1;
1030 }
1031
1032
1033 /*
1034 * This function fills a red-black tree with information from a
1035 * directory block. It returns the number directory entries loaded
1036 * into the tree. If there is an error it is returned in err.
1037 */
htree_dirblock_to_tree(struct file * dir_file,struct inode * dir,ext4_lblk_t block,struct dx_hash_info * hinfo,__u32 start_hash,__u32 start_minor_hash)1038 static int htree_dirblock_to_tree(struct file *dir_file,
1039 struct inode *dir, ext4_lblk_t block,
1040 struct dx_hash_info *hinfo,
1041 __u32 start_hash, __u32 start_minor_hash)
1042 {
1043 struct buffer_head *bh;
1044 struct ext4_dir_entry_2 *de, *top;
1045 int err = 0, count = 0;
1046 struct fscrypt_str fname_crypto_str = FSTR_INIT(NULL, 0), tmp_str;
1047 int csum = ext4_has_feature_metadata_csum(dir->i_sb);
1048
1049 dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
1050 (unsigned long)block));
1051 bh = ext4_read_dirblock(dir, block, DIRENT_HTREE);
1052 if (IS_ERR(bh))
1053 return PTR_ERR(bh);
1054
1055 de = (struct ext4_dir_entry_2 *) bh->b_data;
1056 /* csum entries are not larger in the casefolded encrypted case */
1057 top = (struct ext4_dir_entry_2 *) ((char *) de +
1058 dir->i_sb->s_blocksize -
1059 ext4_dir_rec_len(0,
1060 csum ? NULL : dir));
1061 /* Check if the directory is encrypted */
1062 if (IS_ENCRYPTED(dir)) {
1063 err = fscrypt_prepare_readdir(dir);
1064 if (err < 0) {
1065 brelse(bh);
1066 return err;
1067 }
1068 err = fscrypt_fname_alloc_buffer(EXT4_NAME_LEN,
1069 &fname_crypto_str);
1070 if (err < 0) {
1071 brelse(bh);
1072 return err;
1073 }
1074 }
1075
1076 for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) {
1077 if (ext4_check_dir_entry(dir, NULL, de, bh,
1078 bh->b_data, bh->b_size,
1079 (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
1080 + ((char *)de - bh->b_data))) {
1081 /* silently ignore the rest of the block */
1082 break;
1083 }
1084 if (ext4_hash_in_dirent(dir)) {
1085 if (de->name_len && de->inode) {
1086 hinfo->hash = EXT4_DIRENT_HASH(de);
1087 hinfo->minor_hash = EXT4_DIRENT_MINOR_HASH(de);
1088 } else {
1089 hinfo->hash = 0;
1090 hinfo->minor_hash = 0;
1091 }
1092 } else {
1093 err = ext4fs_dirhash(dir, de->name,
1094 de->name_len, hinfo);
1095 if (err < 0) {
1096 count = err;
1097 goto errout;
1098 }
1099 }
1100 if ((hinfo->hash < start_hash) ||
1101 ((hinfo->hash == start_hash) &&
1102 (hinfo->minor_hash < start_minor_hash)))
1103 continue;
1104 if (de->inode == 0)
1105 continue;
1106 if (!IS_ENCRYPTED(dir)) {
1107 tmp_str.name = de->name;
1108 tmp_str.len = de->name_len;
1109 err = ext4_htree_store_dirent(dir_file,
1110 hinfo->hash, hinfo->minor_hash, de,
1111 &tmp_str);
1112 } else {
1113 int save_len = fname_crypto_str.len;
1114 struct fscrypt_str de_name = FSTR_INIT(de->name,
1115 de->name_len);
1116
1117 /* Directory is encrypted */
1118 err = fscrypt_fname_disk_to_usr(dir, hinfo->hash,
1119 hinfo->minor_hash, &de_name,
1120 &fname_crypto_str);
1121 if (err) {
1122 count = err;
1123 goto errout;
1124 }
1125 err = ext4_htree_store_dirent(dir_file,
1126 hinfo->hash, hinfo->minor_hash, de,
1127 &fname_crypto_str);
1128 fname_crypto_str.len = save_len;
1129 }
1130 if (err != 0) {
1131 count = err;
1132 goto errout;
1133 }
1134 count++;
1135 }
1136 errout:
1137 brelse(bh);
1138 fscrypt_fname_free_buffer(&fname_crypto_str);
1139 return count;
1140 }
1141
1142
1143 /*
1144 * This function fills a red-black tree with information from a
1145 * directory. We start scanning the directory in hash order, starting
1146 * at start_hash and start_minor_hash.
1147 *
1148 * This function returns the number of entries inserted into the tree,
1149 * or a negative error code.
1150 */
ext4_htree_fill_tree(struct file * dir_file,__u32 start_hash,__u32 start_minor_hash,__u32 * next_hash)1151 int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
1152 __u32 start_minor_hash, __u32 *next_hash)
1153 {
1154 struct dx_hash_info hinfo;
1155 struct ext4_dir_entry_2 *de;
1156 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
1157 struct inode *dir;
1158 ext4_lblk_t block;
1159 int count = 0;
1160 int ret, err;
1161 __u32 hashval;
1162 struct fscrypt_str tmp_str;
1163
1164 dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
1165 start_hash, start_minor_hash));
1166 dir = file_inode(dir_file);
1167 if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) {
1168 if (ext4_hash_in_dirent(dir))
1169 hinfo.hash_version = DX_HASH_SIPHASH;
1170 else
1171 hinfo.hash_version =
1172 EXT4_SB(dir->i_sb)->s_def_hash_version;
1173 if (hinfo.hash_version <= DX_HASH_TEA)
1174 hinfo.hash_version +=
1175 EXT4_SB(dir->i_sb)->s_hash_unsigned;
1176 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
1177 if (ext4_has_inline_data(dir)) {
1178 int has_inline_data = 1;
1179 count = ext4_inlinedir_to_tree(dir_file, dir, 0,
1180 &hinfo, start_hash,
1181 start_minor_hash,
1182 &has_inline_data);
1183 if (has_inline_data) {
1184 *next_hash = ~0;
1185 return count;
1186 }
1187 }
1188 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
1189 start_hash, start_minor_hash);
1190 *next_hash = ~0;
1191 return count;
1192 }
1193 hinfo.hash = start_hash;
1194 hinfo.minor_hash = 0;
1195 frame = dx_probe(NULL, dir, &hinfo, frames);
1196 if (IS_ERR(frame))
1197 return PTR_ERR(frame);
1198
1199 /* Add '.' and '..' from the htree header */
1200 if (!start_hash && !start_minor_hash) {
1201 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
1202 tmp_str.name = de->name;
1203 tmp_str.len = de->name_len;
1204 err = ext4_htree_store_dirent(dir_file, 0, 0,
1205 de, &tmp_str);
1206 if (err != 0)
1207 goto errout;
1208 count++;
1209 }
1210 if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
1211 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
1212 de = ext4_next_entry(de, dir->i_sb->s_blocksize);
1213 tmp_str.name = de->name;
1214 tmp_str.len = de->name_len;
1215 err = ext4_htree_store_dirent(dir_file, 2, 0,
1216 de, &tmp_str);
1217 if (err != 0)
1218 goto errout;
1219 count++;
1220 }
1221
1222 while (1) {
1223 if (fatal_signal_pending(current)) {
1224 err = -ERESTARTSYS;
1225 goto errout;
1226 }
1227 cond_resched();
1228 block = dx_get_block(frame->at);
1229 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
1230 start_hash, start_minor_hash);
1231 if (ret < 0) {
1232 err = ret;
1233 goto errout;
1234 }
1235 count += ret;
1236 hashval = ~0;
1237 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
1238 frame, frames, &hashval);
1239 *next_hash = hashval;
1240 if (ret < 0) {
1241 err = ret;
1242 goto errout;
1243 }
1244 /*
1245 * Stop if: (a) there are no more entries, or
1246 * (b) we have inserted at least one entry and the
1247 * next hash value is not a continuation
1248 */
1249 if ((ret == 0) ||
1250 (count && ((hashval & 1) == 0)))
1251 break;
1252 }
1253 dx_release(frames);
1254 dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, "
1255 "next hash: %x\n", count, *next_hash));
1256 return count;
1257 errout:
1258 dx_release(frames);
1259 return (err);
1260 }
1261
search_dirblock(struct buffer_head * bh,struct inode * dir,struct ext4_filename * fname,unsigned int offset,struct ext4_dir_entry_2 ** res_dir)1262 static inline int search_dirblock(struct buffer_head *bh,
1263 struct inode *dir,
1264 struct ext4_filename *fname,
1265 unsigned int offset,
1266 struct ext4_dir_entry_2 **res_dir)
1267 {
1268 return ext4_search_dir(bh, bh->b_data, dir->i_sb->s_blocksize, dir,
1269 fname, offset, res_dir);
1270 }
1271
1272 /*
1273 * Directory block splitting, compacting
1274 */
1275
1276 /*
1277 * Create map of hash values, offsets, and sizes, stored at end of block.
1278 * Returns number of entries mapped.
1279 */
dx_make_map(struct inode * dir,struct buffer_head * bh,struct dx_hash_info * hinfo,struct dx_map_entry * map_tail)1280 static int dx_make_map(struct inode *dir, struct buffer_head *bh,
1281 struct dx_hash_info *hinfo,
1282 struct dx_map_entry *map_tail)
1283 {
1284 int count = 0;
1285 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)bh->b_data;
1286 unsigned int buflen = bh->b_size;
1287 char *base = bh->b_data;
1288 struct dx_hash_info h = *hinfo;
1289 int blocksize = EXT4_BLOCK_SIZE(dir->i_sb);
1290
1291 if (ext4_has_feature_metadata_csum(dir->i_sb))
1292 buflen -= sizeof(struct ext4_dir_entry_tail);
1293
1294 while ((char *) de < base + buflen) {
1295 if (ext4_check_dir_entry(dir, NULL, de, bh, base, buflen,
1296 ((char *)de) - base))
1297 return -EFSCORRUPTED;
1298 if (de->name_len && de->inode) {
1299 if (ext4_hash_in_dirent(dir))
1300 h.hash = EXT4_DIRENT_HASH(de);
1301 else {
1302 int err = ext4fs_dirhash(dir, de->name,
1303 de->name_len, &h);
1304 if (err < 0)
1305 return err;
1306 }
1307 map_tail--;
1308 map_tail->hash = h.hash;
1309 map_tail->offs = ((char *) de - base)>>2;
1310 map_tail->size = ext4_rec_len_from_disk(de->rec_len,
1311 blocksize);
1312 count++;
1313 cond_resched();
1314 }
1315 de = ext4_next_entry(de, blocksize);
1316 }
1317 return count;
1318 }
1319
1320 /* Sort map by hash value */
dx_sort_map(struct dx_map_entry * map,unsigned count)1321 static void dx_sort_map (struct dx_map_entry *map, unsigned count)
1322 {
1323 struct dx_map_entry *p, *q, *top = map + count - 1;
1324 int more;
1325 /* Combsort until bubble sort doesn't suck */
1326 while (count > 2) {
1327 count = count*10/13;
1328 if (count - 9 < 2) /* 9, 10 -> 11 */
1329 count = 11;
1330 for (p = top, q = p - count; q >= map; p--, q--)
1331 if (p->hash < q->hash)
1332 swap(*p, *q);
1333 }
1334 /* Garden variety bubble sort */
1335 do {
1336 more = 0;
1337 q = top;
1338 while (q-- > map) {
1339 if (q[1].hash >= q[0].hash)
1340 continue;
1341 swap(*(q+1), *q);
1342 more = 1;
1343 }
1344 } while(more);
1345 }
1346
dx_insert_block(struct dx_frame * frame,u32 hash,ext4_lblk_t block)1347 static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
1348 {
1349 struct dx_entry *entries = frame->entries;
1350 struct dx_entry *old = frame->at, *new = old + 1;
1351 int count = dx_get_count(entries);
1352
1353 ASSERT(count < dx_get_limit(entries));
1354 ASSERT(old < entries + count);
1355 memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
1356 dx_set_hash(new, hash);
1357 dx_set_block(new, block);
1358 dx_set_count(entries, count + 1);
1359 }
1360
1361 #if IS_ENABLED(CONFIG_UNICODE)
ext4_fname_setup_ci_filename(struct inode * dir,const struct qstr * iname,struct ext4_filename * name)1362 int ext4_fname_setup_ci_filename(struct inode *dir, const struct qstr *iname,
1363 struct ext4_filename *name)
1364 {
1365 struct qstr *cf_name = &name->cf_name;
1366 unsigned char *buf;
1367 struct dx_hash_info *hinfo = &name->hinfo;
1368 int len;
1369
1370 if (!IS_CASEFOLDED(dir) ||
1371 (IS_ENCRYPTED(dir) && !fscrypt_has_encryption_key(dir))) {
1372 cf_name->name = NULL;
1373 return 0;
1374 }
1375
1376 buf = kmalloc(EXT4_NAME_LEN, GFP_NOFS);
1377 if (!buf)
1378 return -ENOMEM;
1379
1380 len = utf8_casefold(dir->i_sb->s_encoding, iname, buf, EXT4_NAME_LEN);
1381 if (len <= 0) {
1382 kfree(buf);
1383 buf = NULL;
1384 }
1385 cf_name->name = buf;
1386 cf_name->len = (unsigned) len;
1387
1388 if (!IS_ENCRYPTED(dir))
1389 return 0;
1390
1391 hinfo->hash_version = DX_HASH_SIPHASH;
1392 hinfo->seed = NULL;
1393 if (cf_name->name)
1394 return ext4fs_dirhash(dir, cf_name->name, cf_name->len, hinfo);
1395 else
1396 return ext4fs_dirhash(dir, iname->name, iname->len, hinfo);
1397 }
1398 #endif
1399
1400 /*
1401 * Test whether a directory entry matches the filename being searched for.
1402 *
1403 * Return: %true if the directory entry matches, otherwise %false.
1404 */
ext4_match(struct inode * parent,const struct ext4_filename * fname,struct ext4_dir_entry_2 * de)1405 static bool ext4_match(struct inode *parent,
1406 const struct ext4_filename *fname,
1407 struct ext4_dir_entry_2 *de)
1408 {
1409 struct fscrypt_name f;
1410
1411 if (!de->inode)
1412 return false;
1413
1414 f.usr_fname = fname->usr_fname;
1415 f.disk_name = fname->disk_name;
1416 #ifdef CONFIG_FS_ENCRYPTION
1417 f.crypto_buf = fname->crypto_buf;
1418 #endif
1419
1420 #if IS_ENABLED(CONFIG_UNICODE)
1421 if (IS_CASEFOLDED(parent) &&
1422 (!IS_ENCRYPTED(parent) || fscrypt_has_encryption_key(parent))) {
1423 /*
1424 * Just checking IS_ENCRYPTED(parent) below is not
1425 * sufficient to decide whether one can use the hash for
1426 * skipping the string comparison, because the key might
1427 * have been added right after
1428 * ext4_fname_setup_ci_filename(). In this case, a hash
1429 * mismatch will be a false negative. Therefore, make
1430 * sure cf_name was properly initialized before
1431 * considering the calculated hash.
1432 */
1433 if (sb_no_casefold_compat_fallback(parent->i_sb) &&
1434 IS_ENCRYPTED(parent) && fname->cf_name.name &&
1435 (fname->hinfo.hash != EXT4_DIRENT_HASH(de) ||
1436 fname->hinfo.minor_hash != EXT4_DIRENT_MINOR_HASH(de)))
1437 return false;
1438 /*
1439 * Treat comparison errors as not a match. The
1440 * only case where it happens is on a disk
1441 * corruption or ENOMEM.
1442 */
1443
1444 return generic_ci_match(parent, fname->usr_fname,
1445 &fname->cf_name, de->name,
1446 de->name_len) > 0;
1447 }
1448 #endif
1449
1450 return fscrypt_match_name(&f, de->name, de->name_len);
1451 }
1452
1453 /*
1454 * Returns 0 if not found, -EFSCORRUPTED on failure, and 1 on success
1455 */
ext4_search_dir(struct buffer_head * bh,char * search_buf,int buf_size,struct inode * dir,struct ext4_filename * fname,unsigned int offset,struct ext4_dir_entry_2 ** res_dir)1456 int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size,
1457 struct inode *dir, struct ext4_filename *fname,
1458 unsigned int offset, struct ext4_dir_entry_2 **res_dir)
1459 {
1460 struct ext4_dir_entry_2 * de;
1461 char * dlimit;
1462 int de_len;
1463
1464 de = (struct ext4_dir_entry_2 *)search_buf;
1465 dlimit = search_buf + buf_size;
1466 while ((char *) de < dlimit - EXT4_BASE_DIR_LEN) {
1467 /* this code is executed quadratically often */
1468 /* do minimal checking `by hand' */
1469 if (de->name + de->name_len <= dlimit &&
1470 ext4_match(dir, fname, de)) {
1471 /* found a match - just to be sure, do
1472 * a full check */
1473 if (ext4_check_dir_entry(dir, NULL, de, bh, search_buf,
1474 buf_size, offset))
1475 return -EFSCORRUPTED;
1476 *res_dir = de;
1477 return 1;
1478 }
1479 /* prevent looping on a bad block */
1480 de_len = ext4_rec_len_from_disk(de->rec_len,
1481 dir->i_sb->s_blocksize);
1482 if (de_len <= 0)
1483 return -EFSCORRUPTED;
1484 offset += de_len;
1485 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
1486 }
1487 return 0;
1488 }
1489
is_dx_internal_node(struct inode * dir,ext4_lblk_t block,struct ext4_dir_entry * de)1490 static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block,
1491 struct ext4_dir_entry *de)
1492 {
1493 struct super_block *sb = dir->i_sb;
1494
1495 if (!is_dx(dir))
1496 return 0;
1497 if (block == 0)
1498 return 1;
1499 if (de->inode == 0 &&
1500 ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) ==
1501 sb->s_blocksize)
1502 return 1;
1503 return 0;
1504 }
1505
1506 /*
1507 * __ext4_find_entry()
1508 *
1509 * finds an entry in the specified directory with the wanted name. It
1510 * returns the cache buffer in which the entry was found, and the entry
1511 * itself (as a parameter - res_dir). It does NOT read the inode of the
1512 * entry - you'll have to do that yourself if you want to.
1513 *
1514 * The returned buffer_head has ->b_count elevated. The caller is expected
1515 * to brelse() it when appropriate.
1516 */
__ext4_find_entry(struct inode * dir,struct ext4_filename * fname,struct ext4_dir_entry_2 ** res_dir,int * inlined)1517 static struct buffer_head *__ext4_find_entry(struct inode *dir,
1518 struct ext4_filename *fname,
1519 struct ext4_dir_entry_2 **res_dir,
1520 int *inlined)
1521 {
1522 struct super_block *sb;
1523 struct buffer_head *bh_use[NAMEI_RA_SIZE];
1524 struct buffer_head *bh, *ret = NULL;
1525 ext4_lblk_t start, block;
1526 const u8 *name = fname->usr_fname->name;
1527 size_t ra_max = 0; /* Number of bh's in the readahead
1528 buffer, bh_use[] */
1529 size_t ra_ptr = 0; /* Current index into readahead
1530 buffer */
1531 ext4_lblk_t nblocks;
1532 int i, namelen, retval;
1533
1534 *res_dir = NULL;
1535 sb = dir->i_sb;
1536 namelen = fname->usr_fname->len;
1537 if (namelen > EXT4_NAME_LEN)
1538 return NULL;
1539
1540 if (ext4_has_inline_data(dir)) {
1541 int has_inline_data = 1;
1542 ret = ext4_find_inline_entry(dir, fname, res_dir,
1543 &has_inline_data);
1544 if (inlined)
1545 *inlined = has_inline_data;
1546 if (has_inline_data || IS_ERR(ret))
1547 goto cleanup_and_exit;
1548 }
1549
1550 if ((namelen <= 2) && (name[0] == '.') &&
1551 (name[1] == '.' || name[1] == '\0')) {
1552 /*
1553 * "." or ".." will only be in the first block
1554 * NFS may look up ".."; "." should be handled by the VFS
1555 */
1556 block = start = 0;
1557 nblocks = 1;
1558 goto restart;
1559 }
1560 if (is_dx(dir)) {
1561 ret = ext4_dx_find_entry(dir, fname, res_dir);
1562 /*
1563 * On success, or if the error was file not found,
1564 * return. Otherwise, fall back to doing a search the
1565 * old fashioned way.
1566 */
1567 if (IS_ERR(ret) && PTR_ERR(ret) == ERR_BAD_DX_DIR)
1568 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
1569 "falling back\n"));
1570 else if (!sb_no_casefold_compat_fallback(dir->i_sb) &&
1571 *res_dir == NULL && IS_CASEFOLDED(dir))
1572 dxtrace(printk(KERN_DEBUG "ext4_find_entry: casefold "
1573 "failed, falling back\n"));
1574 else
1575 goto cleanup_and_exit;
1576 ret = NULL;
1577 }
1578 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1579 if (!nblocks) {
1580 ret = NULL;
1581 goto cleanup_and_exit;
1582 }
1583 start = EXT4_I(dir)->i_dir_start_lookup;
1584 if (start >= nblocks)
1585 start = 0;
1586 block = start;
1587 restart:
1588 do {
1589 /*
1590 * We deal with the read-ahead logic here.
1591 */
1592 cond_resched();
1593 if (ra_ptr >= ra_max) {
1594 /* Refill the readahead buffer */
1595 ra_ptr = 0;
1596 if (block < start)
1597 ra_max = start - block;
1598 else
1599 ra_max = nblocks - block;
1600 ra_max = min(ra_max, ARRAY_SIZE(bh_use));
1601 retval = ext4_bread_batch(dir, block, ra_max,
1602 false /* wait */, bh_use);
1603 if (retval) {
1604 ret = ERR_PTR(retval);
1605 ra_max = 0;
1606 goto cleanup_and_exit;
1607 }
1608 }
1609 if ((bh = bh_use[ra_ptr++]) == NULL)
1610 goto next;
1611 wait_on_buffer(bh);
1612 if (!buffer_uptodate(bh)) {
1613 EXT4_ERROR_INODE_ERR(dir, EIO,
1614 "reading directory lblock %lu",
1615 (unsigned long) block);
1616 brelse(bh);
1617 ret = ERR_PTR(-EIO);
1618 goto cleanup_and_exit;
1619 }
1620 if (!buffer_verified(bh) &&
1621 !is_dx_internal_node(dir, block,
1622 (struct ext4_dir_entry *)bh->b_data) &&
1623 !ext4_dirblock_csum_verify(dir, bh)) {
1624 EXT4_ERROR_INODE_ERR(dir, EFSBADCRC,
1625 "checksumming directory "
1626 "block %lu", (unsigned long)block);
1627 brelse(bh);
1628 ret = ERR_PTR(-EFSBADCRC);
1629 goto cleanup_and_exit;
1630 }
1631 set_buffer_verified(bh);
1632 i = search_dirblock(bh, dir, fname,
1633 block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
1634 if (i == 1) {
1635 EXT4_I(dir)->i_dir_start_lookup = block;
1636 ret = bh;
1637 goto cleanup_and_exit;
1638 } else {
1639 brelse(bh);
1640 if (i < 0) {
1641 ret = ERR_PTR(i);
1642 goto cleanup_and_exit;
1643 }
1644 }
1645 next:
1646 if (++block >= nblocks)
1647 block = 0;
1648 } while (block != start);
1649
1650 /*
1651 * If the directory has grown while we were searching, then
1652 * search the last part of the directory before giving up.
1653 */
1654 block = nblocks;
1655 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1656 if (block < nblocks) {
1657 start = 0;
1658 goto restart;
1659 }
1660
1661 cleanup_and_exit:
1662 /* Clean up the read-ahead blocks */
1663 for (; ra_ptr < ra_max; ra_ptr++)
1664 brelse(bh_use[ra_ptr]);
1665 return ret;
1666 }
1667
ext4_find_entry(struct inode * dir,const struct qstr * d_name,struct ext4_dir_entry_2 ** res_dir,int * inlined)1668 static struct buffer_head *ext4_find_entry(struct inode *dir,
1669 const struct qstr *d_name,
1670 struct ext4_dir_entry_2 **res_dir,
1671 int *inlined)
1672 {
1673 int err;
1674 struct ext4_filename fname;
1675 struct buffer_head *bh;
1676
1677 err = ext4_fname_setup_filename(dir, d_name, 1, &fname);
1678 if (err == -ENOENT)
1679 return NULL;
1680 if (err)
1681 return ERR_PTR(err);
1682
1683 bh = __ext4_find_entry(dir, &fname, res_dir, inlined);
1684
1685 ext4_fname_free_filename(&fname);
1686 return bh;
1687 }
1688
ext4_lookup_entry(struct inode * dir,struct dentry * dentry,struct ext4_dir_entry_2 ** res_dir)1689 static struct buffer_head *ext4_lookup_entry(struct inode *dir,
1690 struct dentry *dentry,
1691 struct ext4_dir_entry_2 **res_dir)
1692 {
1693 int err;
1694 struct ext4_filename fname;
1695 struct buffer_head *bh;
1696
1697 err = ext4_fname_prepare_lookup(dir, dentry, &fname);
1698 if (err == -ENOENT)
1699 return NULL;
1700 if (err)
1701 return ERR_PTR(err);
1702
1703 bh = __ext4_find_entry(dir, &fname, res_dir, NULL);
1704
1705 ext4_fname_free_filename(&fname);
1706 return bh;
1707 }
1708
ext4_dx_find_entry(struct inode * dir,struct ext4_filename * fname,struct ext4_dir_entry_2 ** res_dir)1709 static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
1710 struct ext4_filename *fname,
1711 struct ext4_dir_entry_2 **res_dir)
1712 {
1713 struct super_block * sb = dir->i_sb;
1714 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
1715 struct buffer_head *bh;
1716 ext4_lblk_t block;
1717 int retval;
1718
1719 #ifdef CONFIG_FS_ENCRYPTION
1720 *res_dir = NULL;
1721 #endif
1722 frame = dx_probe(fname, dir, NULL, frames);
1723 if (IS_ERR(frame))
1724 return ERR_CAST(frame);
1725 do {
1726 block = dx_get_block(frame->at);
1727 bh = ext4_read_dirblock(dir, block, DIRENT_HTREE);
1728 if (IS_ERR(bh))
1729 goto errout;
1730
1731 retval = search_dirblock(bh, dir, fname,
1732 block << EXT4_BLOCK_SIZE_BITS(sb),
1733 res_dir);
1734 if (retval == 1)
1735 goto success;
1736 brelse(bh);
1737 if (retval < 0) {
1738 bh = ERR_PTR(ERR_BAD_DX_DIR);
1739 goto errout;
1740 }
1741
1742 /* Check to see if we should continue to search */
1743 retval = ext4_htree_next_block(dir, fname->hinfo.hash, frame,
1744 frames, NULL);
1745 if (retval < 0) {
1746 ext4_warning_inode(dir,
1747 "error %d reading directory index block",
1748 retval);
1749 bh = ERR_PTR(retval);
1750 goto errout;
1751 }
1752 } while (retval == 1);
1753
1754 bh = NULL;
1755 errout:
1756 dxtrace(printk(KERN_DEBUG "%s not found\n", fname->usr_fname->name));
1757 success:
1758 dx_release(frames);
1759 return bh;
1760 }
1761
ext4_lookup(struct inode * dir,struct dentry * dentry,unsigned int flags)1762 static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
1763 {
1764 struct inode *inode;
1765 struct ext4_dir_entry_2 *de;
1766 struct buffer_head *bh;
1767
1768 if (dentry->d_name.len > EXT4_NAME_LEN)
1769 return ERR_PTR(-ENAMETOOLONG);
1770
1771 bh = ext4_lookup_entry(dir, dentry, &de);
1772 if (IS_ERR(bh))
1773 return ERR_CAST(bh);
1774 inode = NULL;
1775 if (bh) {
1776 __u32 ino = le32_to_cpu(de->inode);
1777 brelse(bh);
1778 if (!ext4_valid_inum(dir->i_sb, ino)) {
1779 EXT4_ERROR_INODE(dir, "bad inode number: %u", ino);
1780 return ERR_PTR(-EFSCORRUPTED);
1781 }
1782 if (unlikely(ino == dir->i_ino)) {
1783 EXT4_ERROR_INODE(dir, "'%pd' linked to parent dir",
1784 dentry);
1785 return ERR_PTR(-EFSCORRUPTED);
1786 }
1787 inode = ext4_iget(dir->i_sb, ino, EXT4_IGET_NORMAL);
1788 if (inode == ERR_PTR(-ESTALE)) {
1789 EXT4_ERROR_INODE(dir,
1790 "deleted inode referenced: %u",
1791 ino);
1792 return ERR_PTR(-EFSCORRUPTED);
1793 }
1794 if (!IS_ERR(inode) && IS_ENCRYPTED(dir) &&
1795 (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) &&
1796 !fscrypt_has_permitted_context(dir, inode)) {
1797 ext4_warning(inode->i_sb,
1798 "Inconsistent encryption contexts: %lu/%lu",
1799 dir->i_ino, inode->i_ino);
1800 iput(inode);
1801 return ERR_PTR(-EPERM);
1802 }
1803 }
1804
1805 if (IS_ENABLED(CONFIG_UNICODE) && !inode && IS_CASEFOLDED(dir)) {
1806 /* Eventually we want to call d_add_ci(dentry, NULL)
1807 * for negative dentries in the encoding case as
1808 * well. For now, prevent the negative dentry
1809 * from being cached.
1810 */
1811 return NULL;
1812 }
1813
1814 return d_splice_alias(inode, dentry);
1815 }
1816
1817
ext4_get_parent(struct dentry * child)1818 struct dentry *ext4_get_parent(struct dentry *child)
1819 {
1820 __u32 ino;
1821 struct ext4_dir_entry_2 * de;
1822 struct buffer_head *bh;
1823
1824 bh = ext4_find_entry(d_inode(child), &dotdot_name, &de, NULL);
1825 if (IS_ERR(bh))
1826 return ERR_CAST(bh);
1827 if (!bh)
1828 return ERR_PTR(-ENOENT);
1829 ino = le32_to_cpu(de->inode);
1830 brelse(bh);
1831
1832 if (!ext4_valid_inum(child->d_sb, ino)) {
1833 EXT4_ERROR_INODE(d_inode(child),
1834 "bad parent inode number: %u", ino);
1835 return ERR_PTR(-EFSCORRUPTED);
1836 }
1837
1838 return d_obtain_alias(ext4_iget(child->d_sb, ino, EXT4_IGET_NORMAL));
1839 }
1840
1841 /*
1842 * Move count entries from end of map between two memory locations.
1843 * Returns pointer to last entry moved.
1844 */
1845 static struct ext4_dir_entry_2 *
dx_move_dirents(struct inode * dir,char * from,char * to,struct dx_map_entry * map,int count,unsigned blocksize)1846 dx_move_dirents(struct inode *dir, char *from, char *to,
1847 struct dx_map_entry *map, int count,
1848 unsigned blocksize)
1849 {
1850 unsigned rec_len = 0;
1851
1852 while (count--) {
1853 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
1854 (from + (map->offs<<2));
1855 rec_len = ext4_dir_rec_len(de->name_len, dir);
1856
1857 memcpy (to, de, rec_len);
1858 ((struct ext4_dir_entry_2 *) to)->rec_len =
1859 ext4_rec_len_to_disk(rec_len, blocksize);
1860
1861 /* wipe dir_entry excluding the rec_len field */
1862 de->inode = 0;
1863 memset(&de->name_len, 0, ext4_rec_len_from_disk(de->rec_len,
1864 blocksize) -
1865 offsetof(struct ext4_dir_entry_2,
1866 name_len));
1867
1868 map++;
1869 to += rec_len;
1870 }
1871 return (struct ext4_dir_entry_2 *) (to - rec_len);
1872 }
1873
1874 /*
1875 * Compact each dir entry in the range to the minimal rec_len.
1876 * Returns pointer to last entry in range.
1877 */
dx_pack_dirents(struct inode * dir,char * base,unsigned int blocksize)1878 static struct ext4_dir_entry_2 *dx_pack_dirents(struct inode *dir, char *base,
1879 unsigned int blocksize)
1880 {
1881 struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
1882 unsigned rec_len = 0;
1883
1884 prev = to = de;
1885 while ((char*)de < base + blocksize) {
1886 next = ext4_next_entry(de, blocksize);
1887 if (de->inode && de->name_len) {
1888 rec_len = ext4_dir_rec_len(de->name_len, dir);
1889 if (de > to)
1890 memmove(to, de, rec_len);
1891 to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
1892 prev = to;
1893 to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
1894 }
1895 de = next;
1896 }
1897 return prev;
1898 }
1899
1900 /*
1901 * Split a full leaf block to make room for a new dir entry.
1902 * Allocate a new block, and move entries so that they are approx. equally full.
1903 * Returns pointer to de in block into which the new entry will be inserted.
1904 */
do_split(handle_t * handle,struct inode * dir,struct buffer_head ** bh,struct dx_frame * frame,struct dx_hash_info * hinfo)1905 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
1906 struct buffer_head **bh,struct dx_frame *frame,
1907 struct dx_hash_info *hinfo)
1908 {
1909 unsigned blocksize = dir->i_sb->s_blocksize;
1910 unsigned continued;
1911 int count;
1912 struct buffer_head *bh2;
1913 ext4_lblk_t newblock;
1914 u32 hash2;
1915 struct dx_map_entry *map;
1916 char *data1 = (*bh)->b_data, *data2;
1917 unsigned split, move, size;
1918 struct ext4_dir_entry_2 *de = NULL, *de2;
1919 int csum_size = 0;
1920 int err = 0, i;
1921
1922 if (ext4_has_feature_metadata_csum(dir->i_sb))
1923 csum_size = sizeof(struct ext4_dir_entry_tail);
1924
1925 bh2 = ext4_append(handle, dir, &newblock);
1926 if (IS_ERR(bh2)) {
1927 brelse(*bh);
1928 *bh = NULL;
1929 return ERR_CAST(bh2);
1930 }
1931
1932 BUFFER_TRACE(*bh, "get_write_access");
1933 err = ext4_journal_get_write_access(handle, dir->i_sb, *bh,
1934 EXT4_JTR_NONE);
1935 if (err)
1936 goto journal_error;
1937
1938 BUFFER_TRACE(frame->bh, "get_write_access");
1939 err = ext4_journal_get_write_access(handle, dir->i_sb, frame->bh,
1940 EXT4_JTR_NONE);
1941 if (err)
1942 goto journal_error;
1943
1944 data2 = bh2->b_data;
1945
1946 /* create map in the end of data2 block */
1947 map = (struct dx_map_entry *) (data2 + blocksize);
1948 count = dx_make_map(dir, *bh, hinfo, map);
1949 if (count < 0) {
1950 err = count;
1951 goto journal_error;
1952 }
1953 map -= count;
1954 dx_sort_map(map, count);
1955 /* Ensure that neither split block is over half full */
1956 size = 0;
1957 move = 0;
1958 for (i = count-1; i >= 0; i--) {
1959 /* is more than half of this entry in 2nd half of the block? */
1960 if (size + map[i].size/2 > blocksize/2)
1961 break;
1962 size += map[i].size;
1963 move++;
1964 }
1965 /*
1966 * map index at which we will split
1967 *
1968 * If the sum of active entries didn't exceed half the block size, just
1969 * split it in half by count; each resulting block will have at least
1970 * half the space free.
1971 */
1972 if (i >= 0)
1973 split = count - move;
1974 else
1975 split = count/2;
1976
1977 if (WARN_ON_ONCE(split == 0)) {
1978 /* Should never happen, but avoid out-of-bounds access below */
1979 ext4_error_inode_block(dir, (*bh)->b_blocknr, 0,
1980 "bad indexed directory? hash=%08x:%08x count=%d move=%u",
1981 hinfo->hash, hinfo->minor_hash, count, move);
1982 err = -EFSCORRUPTED;
1983 goto out;
1984 }
1985
1986 hash2 = map[split].hash;
1987 continued = hash2 == map[split - 1].hash;
1988 dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
1989 (unsigned long)dx_get_block(frame->at),
1990 hash2, split, count-split));
1991
1992 /* Fancy dance to stay within two buffers */
1993 de2 = dx_move_dirents(dir, data1, data2, map + split, count - split,
1994 blocksize);
1995 de = dx_pack_dirents(dir, data1, blocksize);
1996 de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
1997 (char *) de,
1998 blocksize);
1999 de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
2000 (char *) de2,
2001 blocksize);
2002 if (csum_size) {
2003 ext4_initialize_dirent_tail(*bh, blocksize);
2004 ext4_initialize_dirent_tail(bh2, blocksize);
2005 }
2006
2007 dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data1,
2008 blocksize, 1));
2009 dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data2,
2010 blocksize, 1));
2011
2012 /* Which block gets the new entry? */
2013 if (hinfo->hash >= hash2) {
2014 swap(*bh, bh2);
2015 de = de2;
2016 }
2017 dx_insert_block(frame, hash2 + continued, newblock);
2018 err = ext4_handle_dirty_dirblock(handle, dir, bh2);
2019 if (err)
2020 goto journal_error;
2021 err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
2022 if (err)
2023 goto journal_error;
2024 brelse(bh2);
2025 dxtrace(dx_show_index("frame", frame->entries));
2026 return de;
2027
2028 journal_error:
2029 ext4_std_error(dir->i_sb, err);
2030 out:
2031 brelse(*bh);
2032 brelse(bh2);
2033 *bh = NULL;
2034 return ERR_PTR(err);
2035 }
2036
ext4_find_dest_de(struct inode * dir,struct buffer_head * bh,void * buf,int buf_size,struct ext4_filename * fname,struct ext4_dir_entry_2 ** dest_de)2037 int ext4_find_dest_de(struct inode *dir, struct buffer_head *bh,
2038 void *buf, int buf_size,
2039 struct ext4_filename *fname,
2040 struct ext4_dir_entry_2 **dest_de)
2041 {
2042 struct ext4_dir_entry_2 *de;
2043 unsigned short reclen = ext4_dir_rec_len(fname_len(fname), dir);
2044 int nlen, rlen;
2045 unsigned int offset = 0;
2046 char *top;
2047
2048 de = buf;
2049 top = buf + buf_size - reclen;
2050 while ((char *) de <= top) {
2051 if (ext4_check_dir_entry(dir, NULL, de, bh,
2052 buf, buf_size, offset))
2053 return -EFSCORRUPTED;
2054 if (ext4_match(dir, fname, de))
2055 return -EEXIST;
2056 nlen = ext4_dir_rec_len(de->name_len, dir);
2057 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
2058 if ((de->inode ? rlen - nlen : rlen) >= reclen)
2059 break;
2060 de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
2061 offset += rlen;
2062 }
2063 if ((char *) de > top)
2064 return -ENOSPC;
2065
2066 *dest_de = de;
2067 return 0;
2068 }
2069
ext4_insert_dentry(struct inode * dir,struct inode * inode,struct ext4_dir_entry_2 * de,int buf_size,struct ext4_filename * fname)2070 void ext4_insert_dentry(struct inode *dir,
2071 struct inode *inode,
2072 struct ext4_dir_entry_2 *de,
2073 int buf_size,
2074 struct ext4_filename *fname)
2075 {
2076
2077 int nlen, rlen;
2078
2079 nlen = ext4_dir_rec_len(de->name_len, dir);
2080 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
2081 if (de->inode) {
2082 struct ext4_dir_entry_2 *de1 =
2083 (struct ext4_dir_entry_2 *)((char *)de + nlen);
2084 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, buf_size);
2085 de->rec_len = ext4_rec_len_to_disk(nlen, buf_size);
2086 de = de1;
2087 }
2088 de->file_type = EXT4_FT_UNKNOWN;
2089 de->inode = cpu_to_le32(inode->i_ino);
2090 ext4_set_de_type(inode->i_sb, de, inode->i_mode);
2091 de->name_len = fname_len(fname);
2092 memcpy(de->name, fname_name(fname), fname_len(fname));
2093 if (ext4_hash_in_dirent(dir)) {
2094 struct dx_hash_info *hinfo = &fname->hinfo;
2095
2096 EXT4_DIRENT_HASHES(de)->hash = cpu_to_le32(hinfo->hash);
2097 EXT4_DIRENT_HASHES(de)->minor_hash =
2098 cpu_to_le32(hinfo->minor_hash);
2099 }
2100 }
2101
2102 /*
2103 * Add a new entry into a directory (leaf) block. If de is non-NULL,
2104 * it points to a directory entry which is guaranteed to be large
2105 * enough for new directory entry. If de is NULL, then
2106 * add_dirent_to_buf will attempt search the directory block for
2107 * space. It will return -ENOSPC if no space is available, and -EIO
2108 * and -EEXIST if directory entry already exists.
2109 */
add_dirent_to_buf(handle_t * handle,struct ext4_filename * fname,struct inode * dir,struct inode * inode,struct ext4_dir_entry_2 * de,struct buffer_head * bh)2110 static int add_dirent_to_buf(handle_t *handle, struct ext4_filename *fname,
2111 struct inode *dir,
2112 struct inode *inode, struct ext4_dir_entry_2 *de,
2113 struct buffer_head *bh)
2114 {
2115 unsigned int blocksize = dir->i_sb->s_blocksize;
2116 int csum_size = 0;
2117 int err, err2;
2118
2119 if (ext4_has_feature_metadata_csum(inode->i_sb))
2120 csum_size = sizeof(struct ext4_dir_entry_tail);
2121
2122 if (!de) {
2123 err = ext4_find_dest_de(dir, bh, bh->b_data,
2124 blocksize - csum_size, fname, &de);
2125 if (err)
2126 return err;
2127 }
2128 BUFFER_TRACE(bh, "get_write_access");
2129 err = ext4_journal_get_write_access(handle, dir->i_sb, bh,
2130 EXT4_JTR_NONE);
2131 if (err) {
2132 ext4_std_error(dir->i_sb, err);
2133 return err;
2134 }
2135
2136 /* By now the buffer is marked for journaling */
2137 ext4_insert_dentry(dir, inode, de, blocksize, fname);
2138
2139 /*
2140 * XXX shouldn't update any times until successful
2141 * completion of syscall, but too many callers depend
2142 * on this.
2143 *
2144 * XXX similarly, too many callers depend on
2145 * ext4_new_inode() setting the times, but error
2146 * recovery deletes the inode, so the worst that can
2147 * happen is that the times are slightly out of date
2148 * and/or different from the directory change time.
2149 */
2150 inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
2151 ext4_update_dx_flag(dir);
2152 inode_inc_iversion(dir);
2153 err2 = ext4_mark_inode_dirty(handle, dir);
2154 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
2155 err = ext4_handle_dirty_dirblock(handle, dir, bh);
2156 if (err)
2157 ext4_std_error(dir->i_sb, err);
2158 return err ? err : err2;
2159 }
2160
ext4_check_dx_root(struct inode * dir,struct dx_root * root)2161 static bool ext4_check_dx_root(struct inode *dir, struct dx_root *root)
2162 {
2163 struct fake_dirent *fde;
2164 const char *error_msg;
2165 unsigned int rlen;
2166 unsigned int blocksize = dir->i_sb->s_blocksize;
2167 char *blockend = (char *)root + dir->i_sb->s_blocksize;
2168
2169 fde = &root->dot;
2170 if (unlikely(fde->name_len != 1)) {
2171 error_msg = "invalid name_len for '.'";
2172 goto corrupted;
2173 }
2174 if (unlikely(strncmp(root->dot_name, ".", fde->name_len))) {
2175 error_msg = "invalid name for '.'";
2176 goto corrupted;
2177 }
2178 rlen = ext4_rec_len_from_disk(fde->rec_len, blocksize);
2179 if (unlikely((char *)fde + rlen >= blockend)) {
2180 error_msg = "invalid rec_len for '.'";
2181 goto corrupted;
2182 }
2183
2184 fde = &root->dotdot;
2185 if (unlikely(fde->name_len != 2)) {
2186 error_msg = "invalid name_len for '..'";
2187 goto corrupted;
2188 }
2189 if (unlikely(strncmp(root->dotdot_name, "..", fde->name_len))) {
2190 error_msg = "invalid name for '..'";
2191 goto corrupted;
2192 }
2193 rlen = ext4_rec_len_from_disk(fde->rec_len, blocksize);
2194 if (unlikely((char *)fde + rlen >= blockend)) {
2195 error_msg = "invalid rec_len for '..'";
2196 goto corrupted;
2197 }
2198
2199 return true;
2200
2201 corrupted:
2202 EXT4_ERROR_INODE(dir, "Corrupt dir, %s, running e2fsck is recommended",
2203 error_msg);
2204 return false;
2205 }
2206
2207 /*
2208 * This converts a one block unindexed directory to a 3 block indexed
2209 * directory, and adds the dentry to the indexed directory.
2210 */
make_indexed_dir(handle_t * handle,struct ext4_filename * fname,struct inode * dir,struct inode * inode,struct buffer_head * bh)2211 static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname,
2212 struct inode *dir,
2213 struct inode *inode, struct buffer_head *bh)
2214 {
2215 struct buffer_head *bh2;
2216 struct dx_root *root;
2217 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
2218 struct dx_entry *entries;
2219 struct ext4_dir_entry_2 *de, *de2;
2220 char *data2, *top;
2221 unsigned len;
2222 int retval;
2223 unsigned blocksize;
2224 ext4_lblk_t block;
2225 struct fake_dirent *fde;
2226 int csum_size = 0;
2227
2228 if (ext4_has_feature_metadata_csum(inode->i_sb))
2229 csum_size = sizeof(struct ext4_dir_entry_tail);
2230
2231 blocksize = dir->i_sb->s_blocksize;
2232 dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
2233 BUFFER_TRACE(bh, "get_write_access");
2234 retval = ext4_journal_get_write_access(handle, dir->i_sb, bh,
2235 EXT4_JTR_NONE);
2236 if (retval) {
2237 ext4_std_error(dir->i_sb, retval);
2238 brelse(bh);
2239 return retval;
2240 }
2241
2242 root = (struct dx_root *) bh->b_data;
2243 if (!ext4_check_dx_root(dir, root)) {
2244 brelse(bh);
2245 return -EFSCORRUPTED;
2246 }
2247
2248 /* The 0th block becomes the root, move the dirents out */
2249 fde = &root->dotdot;
2250 de = (struct ext4_dir_entry_2 *)((char *)fde +
2251 ext4_rec_len_from_disk(fde->rec_len, blocksize));
2252 len = ((char *) root) + (blocksize - csum_size) - (char *) de;
2253
2254 /* Allocate new block for the 0th block's dirents */
2255 bh2 = ext4_append(handle, dir, &block);
2256 if (IS_ERR(bh2)) {
2257 brelse(bh);
2258 return PTR_ERR(bh2);
2259 }
2260 ext4_set_inode_flag(dir, EXT4_INODE_INDEX);
2261 data2 = bh2->b_data;
2262
2263 memcpy(data2, de, len);
2264 memset(de, 0, len); /* wipe old data */
2265 de = (struct ext4_dir_entry_2 *) data2;
2266 top = data2 + len;
2267 while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top) {
2268 if (ext4_check_dir_entry(dir, NULL, de, bh2, data2, len,
2269 (char *)de - data2)) {
2270 brelse(bh2);
2271 brelse(bh);
2272 return -EFSCORRUPTED;
2273 }
2274 de = de2;
2275 }
2276 de->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
2277 (char *) de, blocksize);
2278
2279 if (csum_size)
2280 ext4_initialize_dirent_tail(bh2, blocksize);
2281
2282 /* Initialize the root; the dot dirents already exist */
2283 de = (struct ext4_dir_entry_2 *) (&root->dotdot);
2284 de->rec_len = ext4_rec_len_to_disk(
2285 blocksize - ext4_dir_rec_len(2, NULL), blocksize);
2286 memset (&root->info, 0, sizeof(root->info));
2287 root->info.info_length = sizeof(root->info);
2288 if (ext4_hash_in_dirent(dir))
2289 root->info.hash_version = DX_HASH_SIPHASH;
2290 else
2291 root->info.hash_version =
2292 EXT4_SB(dir->i_sb)->s_def_hash_version;
2293
2294 entries = root->entries;
2295 dx_set_block(entries, 1);
2296 dx_set_count(entries, 1);
2297 dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
2298
2299 /* Initialize as for dx_probe */
2300 fname->hinfo.hash_version = root->info.hash_version;
2301 if (fname->hinfo.hash_version <= DX_HASH_TEA)
2302 fname->hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
2303 fname->hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
2304
2305 /* casefolded encrypted hashes are computed on fname setup */
2306 if (!ext4_hash_in_dirent(dir)) {
2307 int err = ext4fs_dirhash(dir, fname_name(fname),
2308 fname_len(fname), &fname->hinfo);
2309 if (err < 0) {
2310 brelse(bh2);
2311 brelse(bh);
2312 return err;
2313 }
2314 }
2315 memset(frames, 0, sizeof(frames));
2316 frame = frames;
2317 frame->entries = entries;
2318 frame->at = entries;
2319 frame->bh = bh;
2320
2321 retval = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
2322 if (retval)
2323 goto out_frames;
2324 retval = ext4_handle_dirty_dirblock(handle, dir, bh2);
2325 if (retval)
2326 goto out_frames;
2327
2328 de = do_split(handle,dir, &bh2, frame, &fname->hinfo);
2329 if (IS_ERR(de)) {
2330 retval = PTR_ERR(de);
2331 goto out_frames;
2332 }
2333
2334 retval = add_dirent_to_buf(handle, fname, dir, inode, de, bh2);
2335 out_frames:
2336 /*
2337 * Even if the block split failed, we have to properly write
2338 * out all the changes we did so far. Otherwise we can end up
2339 * with corrupted filesystem.
2340 */
2341 if (retval)
2342 ext4_mark_inode_dirty(handle, dir);
2343 dx_release(frames);
2344 brelse(bh2);
2345 return retval;
2346 }
2347
2348 /*
2349 * ext4_add_entry()
2350 *
2351 * adds a file entry to the specified directory, using the same
2352 * semantics as ext4_find_entry(). It returns NULL if it failed.
2353 *
2354 * NOTE!! The inode part of 'de' is left at 0 - which means you
2355 * may not sleep between calling this and putting something into
2356 * the entry, as someone else might have used it while you slept.
2357 */
ext4_add_entry(handle_t * handle,struct dentry * dentry,struct inode * inode)2358 static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
2359 struct inode *inode)
2360 {
2361 struct inode *dir = d_inode(dentry->d_parent);
2362 struct buffer_head *bh = NULL;
2363 struct ext4_dir_entry_2 *de;
2364 struct super_block *sb;
2365 struct ext4_filename fname;
2366 int retval;
2367 int dx_fallback=0;
2368 unsigned blocksize;
2369 ext4_lblk_t block, blocks;
2370 int csum_size = 0;
2371
2372 if (ext4_has_feature_metadata_csum(inode->i_sb))
2373 csum_size = sizeof(struct ext4_dir_entry_tail);
2374
2375 sb = dir->i_sb;
2376 blocksize = sb->s_blocksize;
2377
2378 if (fscrypt_is_nokey_name(dentry))
2379 return -ENOKEY;
2380
2381 if (!generic_ci_validate_strict_name(dir, &dentry->d_name))
2382 return -EINVAL;
2383
2384 retval = ext4_fname_setup_filename(dir, &dentry->d_name, 0, &fname);
2385 if (retval)
2386 return retval;
2387
2388 if (ext4_has_inline_data(dir)) {
2389 retval = ext4_try_add_inline_entry(handle, &fname, dir, inode);
2390 if (retval < 0)
2391 goto out;
2392 if (retval == 1) {
2393 retval = 0;
2394 goto out;
2395 }
2396 }
2397
2398 if (is_dx(dir)) {
2399 retval = ext4_dx_add_entry(handle, &fname, dir, inode);
2400 if (!retval || (retval != ERR_BAD_DX_DIR))
2401 goto out;
2402 /* Can we just ignore htree data? */
2403 if (ext4_has_feature_metadata_csum(sb)) {
2404 EXT4_ERROR_INODE(dir,
2405 "Directory has corrupted htree index.");
2406 retval = -EFSCORRUPTED;
2407 goto out;
2408 }
2409 ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
2410 dx_fallback++;
2411 retval = ext4_mark_inode_dirty(handle, dir);
2412 if (unlikely(retval))
2413 goto out;
2414 }
2415 blocks = dir->i_size >> sb->s_blocksize_bits;
2416 for (block = 0; block < blocks; block++) {
2417 bh = ext4_read_dirblock(dir, block, DIRENT);
2418 if (bh == NULL) {
2419 bh = ext4_bread(handle, dir, block,
2420 EXT4_GET_BLOCKS_CREATE);
2421 goto add_to_new_block;
2422 }
2423 if (IS_ERR(bh)) {
2424 retval = PTR_ERR(bh);
2425 bh = NULL;
2426 goto out;
2427 }
2428 retval = add_dirent_to_buf(handle, &fname, dir, inode,
2429 NULL, bh);
2430 if (retval != -ENOSPC)
2431 goto out;
2432
2433 if (blocks == 1 && !dx_fallback &&
2434 ext4_has_feature_dir_index(sb)) {
2435 retval = make_indexed_dir(handle, &fname, dir,
2436 inode, bh);
2437 bh = NULL; /* make_indexed_dir releases bh */
2438 goto out;
2439 }
2440 brelse(bh);
2441 }
2442 bh = ext4_append(handle, dir, &block);
2443 add_to_new_block:
2444 if (IS_ERR(bh)) {
2445 retval = PTR_ERR(bh);
2446 bh = NULL;
2447 goto out;
2448 }
2449 de = (struct ext4_dir_entry_2 *) bh->b_data;
2450 de->inode = 0;
2451 de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize);
2452
2453 if (csum_size)
2454 ext4_initialize_dirent_tail(bh, blocksize);
2455
2456 retval = add_dirent_to_buf(handle, &fname, dir, inode, de, bh);
2457 out:
2458 ext4_fname_free_filename(&fname);
2459 brelse(bh);
2460 if (retval == 0)
2461 ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY);
2462 return retval;
2463 }
2464
2465 /*
2466 * Returns 0 for success, or a negative error value
2467 */
ext4_dx_add_entry(handle_t * handle,struct ext4_filename * fname,struct inode * dir,struct inode * inode)2468 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
2469 struct inode *dir, struct inode *inode)
2470 {
2471 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
2472 struct dx_entry *entries, *at;
2473 struct buffer_head *bh;
2474 struct super_block *sb = dir->i_sb;
2475 struct ext4_dir_entry_2 *de;
2476 int restart;
2477 int err;
2478
2479 again:
2480 restart = 0;
2481 frame = dx_probe(fname, dir, NULL, frames);
2482 if (IS_ERR(frame))
2483 return PTR_ERR(frame);
2484 entries = frame->entries;
2485 at = frame->at;
2486 bh = ext4_read_dirblock(dir, dx_get_block(frame->at), DIRENT_HTREE);
2487 if (IS_ERR(bh)) {
2488 err = PTR_ERR(bh);
2489 bh = NULL;
2490 goto cleanup;
2491 }
2492
2493 BUFFER_TRACE(bh, "get_write_access");
2494 err = ext4_journal_get_write_access(handle, sb, bh, EXT4_JTR_NONE);
2495 if (err)
2496 goto journal_error;
2497
2498 err = add_dirent_to_buf(handle, fname, dir, inode, NULL, bh);
2499 if (err != -ENOSPC)
2500 goto cleanup;
2501
2502 err = 0;
2503 /* Block full, should compress but for now just split */
2504 dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
2505 dx_get_count(entries), dx_get_limit(entries)));
2506 /* Need to split index? */
2507 if (dx_get_count(entries) == dx_get_limit(entries)) {
2508 ext4_lblk_t newblock;
2509 int levels = frame - frames + 1;
2510 unsigned int icount;
2511 int add_level = 1;
2512 struct dx_entry *entries2;
2513 struct dx_node *node2;
2514 struct buffer_head *bh2;
2515
2516 while (frame > frames) {
2517 if (dx_get_count((frame - 1)->entries) <
2518 dx_get_limit((frame - 1)->entries)) {
2519 add_level = 0;
2520 break;
2521 }
2522 frame--; /* split higher index block */
2523 at = frame->at;
2524 entries = frame->entries;
2525 restart = 1;
2526 }
2527 if (add_level && levels == ext4_dir_htree_level(sb)) {
2528 ext4_warning(sb, "Directory (ino: %lu) index full, "
2529 "reach max htree level :%d",
2530 dir->i_ino, levels);
2531 if (ext4_dir_htree_level(sb) < EXT4_HTREE_LEVEL) {
2532 ext4_warning(sb, "Large directory feature is "
2533 "not enabled on this "
2534 "filesystem");
2535 }
2536 err = -ENOSPC;
2537 goto cleanup;
2538 }
2539 icount = dx_get_count(entries);
2540 bh2 = ext4_append(handle, dir, &newblock);
2541 if (IS_ERR(bh2)) {
2542 err = PTR_ERR(bh2);
2543 goto cleanup;
2544 }
2545 node2 = (struct dx_node *)(bh2->b_data);
2546 entries2 = node2->entries;
2547 memset(&node2->fake, 0, sizeof(struct fake_dirent));
2548 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
2549 sb->s_blocksize);
2550 BUFFER_TRACE(frame->bh, "get_write_access");
2551 err = ext4_journal_get_write_access(handle, sb, frame->bh,
2552 EXT4_JTR_NONE);
2553 if (err) {
2554 brelse(bh2);
2555 goto journal_error;
2556 }
2557 if (!add_level) {
2558 unsigned icount1 = icount/2, icount2 = icount - icount1;
2559 unsigned hash2 = dx_get_hash(entries + icount1);
2560 dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
2561 icount1, icount2));
2562
2563 BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
2564 err = ext4_journal_get_write_access(handle, sb,
2565 (frame - 1)->bh,
2566 EXT4_JTR_NONE);
2567 if (err) {
2568 brelse(bh2);
2569 goto journal_error;
2570 }
2571
2572 memcpy((char *) entries2, (char *) (entries + icount1),
2573 icount2 * sizeof(struct dx_entry));
2574 dx_set_count(entries, icount1);
2575 dx_set_count(entries2, icount2);
2576 dx_set_limit(entries2, dx_node_limit(dir));
2577
2578 /* Which index block gets the new entry? */
2579 if (at - entries >= icount1) {
2580 frame->at = at - entries - icount1 + entries2;
2581 frame->entries = entries = entries2;
2582 swap(frame->bh, bh2);
2583 }
2584 dx_insert_block((frame - 1), hash2, newblock);
2585 dxtrace(dx_show_index("node", frame->entries));
2586 dxtrace(dx_show_index("node",
2587 ((struct dx_node *) bh2->b_data)->entries));
2588 err = ext4_handle_dirty_dx_node(handle, dir, bh2);
2589 if (err) {
2590 brelse(bh2);
2591 goto journal_error;
2592 }
2593 brelse (bh2);
2594 err = ext4_handle_dirty_dx_node(handle, dir,
2595 (frame - 1)->bh);
2596 if (err)
2597 goto journal_error;
2598 err = ext4_handle_dirty_dx_node(handle, dir,
2599 frame->bh);
2600 if (restart || err)
2601 goto journal_error;
2602 } else {
2603 struct dx_root *dxroot;
2604 memcpy((char *) entries2, (char *) entries,
2605 icount * sizeof(struct dx_entry));
2606 dx_set_limit(entries2, dx_node_limit(dir));
2607
2608 /* Set up root */
2609 dx_set_count(entries, 1);
2610 dx_set_block(entries + 0, newblock);
2611 dxroot = (struct dx_root *)frames[0].bh->b_data;
2612 dxroot->info.indirect_levels += 1;
2613 dxtrace(printk(KERN_DEBUG
2614 "Creating %d level index...\n",
2615 dxroot->info.indirect_levels));
2616 err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
2617 if (err) {
2618 brelse(bh2);
2619 goto journal_error;
2620 }
2621 err = ext4_handle_dirty_dx_node(handle, dir, bh2);
2622 brelse(bh2);
2623 restart = 1;
2624 goto journal_error;
2625 }
2626 }
2627 de = do_split(handle, dir, &bh, frame, &fname->hinfo);
2628 if (IS_ERR(de)) {
2629 err = PTR_ERR(de);
2630 goto cleanup;
2631 }
2632 err = add_dirent_to_buf(handle, fname, dir, inode, de, bh);
2633 goto cleanup;
2634
2635 journal_error:
2636 ext4_std_error(dir->i_sb, err); /* this is a no-op if err == 0 */
2637 cleanup:
2638 brelse(bh);
2639 dx_release(frames);
2640 /* @restart is true means htree-path has been changed, we need to
2641 * repeat dx_probe() to find out valid htree-path
2642 */
2643 if (restart && err == 0)
2644 goto again;
2645 return err;
2646 }
2647
2648 /*
2649 * ext4_generic_delete_entry deletes a directory entry by merging it
2650 * with the previous entry
2651 */
ext4_generic_delete_entry(struct inode * dir,struct ext4_dir_entry_2 * de_del,struct buffer_head * bh,void * entry_buf,int buf_size,int csum_size)2652 int ext4_generic_delete_entry(struct inode *dir,
2653 struct ext4_dir_entry_2 *de_del,
2654 struct buffer_head *bh,
2655 void *entry_buf,
2656 int buf_size,
2657 int csum_size)
2658 {
2659 struct ext4_dir_entry_2 *de, *pde;
2660 unsigned int blocksize = dir->i_sb->s_blocksize;
2661 int i;
2662
2663 i = 0;
2664 pde = NULL;
2665 de = entry_buf;
2666 while (i < buf_size - csum_size) {
2667 if (ext4_check_dir_entry(dir, NULL, de, bh,
2668 entry_buf, buf_size, i))
2669 return -EFSCORRUPTED;
2670 if (de == de_del) {
2671 if (pde) {
2672 pde->rec_len = ext4_rec_len_to_disk(
2673 ext4_rec_len_from_disk(pde->rec_len,
2674 blocksize) +
2675 ext4_rec_len_from_disk(de->rec_len,
2676 blocksize),
2677 blocksize);
2678
2679 /* wipe entire dir_entry */
2680 memset(de, 0, ext4_rec_len_from_disk(de->rec_len,
2681 blocksize));
2682 } else {
2683 /* wipe dir_entry excluding the rec_len field */
2684 de->inode = 0;
2685 memset(&de->name_len, 0,
2686 ext4_rec_len_from_disk(de->rec_len,
2687 blocksize) -
2688 offsetof(struct ext4_dir_entry_2,
2689 name_len));
2690 }
2691
2692 inode_inc_iversion(dir);
2693 return 0;
2694 }
2695 i += ext4_rec_len_from_disk(de->rec_len, blocksize);
2696 pde = de;
2697 de = ext4_next_entry(de, blocksize);
2698 }
2699 return -ENOENT;
2700 }
2701
ext4_delete_entry(handle_t * handle,struct inode * dir,struct ext4_dir_entry_2 * de_del,struct buffer_head * bh)2702 static int ext4_delete_entry(handle_t *handle,
2703 struct inode *dir,
2704 struct ext4_dir_entry_2 *de_del,
2705 struct buffer_head *bh)
2706 {
2707 int err, csum_size = 0;
2708
2709 if (ext4_has_inline_data(dir)) {
2710 int has_inline_data = 1;
2711 err = ext4_delete_inline_entry(handle, dir, de_del, bh,
2712 &has_inline_data);
2713 if (has_inline_data)
2714 return err;
2715 }
2716
2717 if (ext4_has_feature_metadata_csum(dir->i_sb))
2718 csum_size = sizeof(struct ext4_dir_entry_tail);
2719
2720 BUFFER_TRACE(bh, "get_write_access");
2721 err = ext4_journal_get_write_access(handle, dir->i_sb, bh,
2722 EXT4_JTR_NONE);
2723 if (unlikely(err))
2724 goto out;
2725
2726 err = ext4_generic_delete_entry(dir, de_del, bh, bh->b_data,
2727 dir->i_sb->s_blocksize, csum_size);
2728 if (err)
2729 goto out;
2730
2731 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
2732 err = ext4_handle_dirty_dirblock(handle, dir, bh);
2733 if (unlikely(err))
2734 goto out;
2735
2736 return 0;
2737 out:
2738 if (err != -ENOENT)
2739 ext4_std_error(dir->i_sb, err);
2740 return err;
2741 }
2742
2743 /*
2744 * Set directory link count to 1 if nlinks > EXT4_LINK_MAX, or if nlinks == 2
2745 * since this indicates that nlinks count was previously 1 to avoid overflowing
2746 * the 16-bit i_links_count field on disk. Directories with i_nlink == 1 mean
2747 * that subdirectory link counts are not being maintained accurately.
2748 *
2749 * The caller has already checked for i_nlink overflow in case the DIR_LINK
2750 * feature is not enabled and returned -EMLINK. The is_dx() check is a proxy
2751 * for checking S_ISDIR(inode) (since the INODE_INDEX feature will not be set
2752 * on regular files) and to avoid creating huge/slow non-HTREE directories.
2753 */
ext4_inc_count(struct inode * inode)2754 static void ext4_inc_count(struct inode *inode)
2755 {
2756 inc_nlink(inode);
2757 if (is_dx(inode) &&
2758 (inode->i_nlink > EXT4_LINK_MAX || inode->i_nlink == 2))
2759 set_nlink(inode, 1);
2760 }
2761
2762 /*
2763 * If a directory had nlink == 1, then we should let it be 1. This indicates
2764 * directory has >EXT4_LINK_MAX subdirs.
2765 */
ext4_dec_count(struct inode * inode)2766 static void ext4_dec_count(struct inode *inode)
2767 {
2768 if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
2769 drop_nlink(inode);
2770 }
2771
2772
2773 /*
2774 * Add non-directory inode to a directory. On success, the inode reference is
2775 * consumed by dentry is instantiation. This is also indicated by clearing of
2776 * *inodep pointer. On failure, the caller is responsible for dropping the
2777 * inode reference in the safe context.
2778 */
ext4_add_nondir(handle_t * handle,struct dentry * dentry,struct inode ** inodep)2779 static int ext4_add_nondir(handle_t *handle,
2780 struct dentry *dentry, struct inode **inodep)
2781 {
2782 struct inode *dir = d_inode(dentry->d_parent);
2783 struct inode *inode = *inodep;
2784 int err = ext4_add_entry(handle, dentry, inode);
2785 if (!err) {
2786 err = ext4_mark_inode_dirty(handle, inode);
2787 if (IS_DIRSYNC(dir))
2788 ext4_handle_sync(handle);
2789 d_instantiate_new(dentry, inode);
2790 *inodep = NULL;
2791 return err;
2792 }
2793 drop_nlink(inode);
2794 ext4_mark_inode_dirty(handle, inode);
2795 ext4_orphan_add(handle, inode);
2796 unlock_new_inode(inode);
2797 return err;
2798 }
2799
2800 /*
2801 * By the time this is called, we already have created
2802 * the directory cache entry for the new file, but it
2803 * is so far negative - it has no inode.
2804 *
2805 * If the create succeeds, we fill in the inode information
2806 * with d_instantiate().
2807 */
ext4_create(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,umode_t mode,bool excl)2808 static int ext4_create(struct mnt_idmap *idmap, struct inode *dir,
2809 struct dentry *dentry, umode_t mode, bool excl)
2810 {
2811 handle_t *handle;
2812 struct inode *inode;
2813 int err, credits, retries = 0;
2814
2815 err = dquot_initialize(dir);
2816 if (err)
2817 return err;
2818
2819 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2820 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2821 retry:
2822 inode = ext4_new_inode_start_handle(idmap, dir, mode, &dentry->d_name,
2823 0, NULL, EXT4_HT_DIR, credits);
2824 handle = ext4_journal_current_handle();
2825 err = PTR_ERR(inode);
2826 if (!IS_ERR(inode)) {
2827 inode->i_op = &ext4_file_inode_operations;
2828 inode->i_fop = &ext4_file_operations;
2829 ext4_set_aops(inode);
2830 err = ext4_add_nondir(handle, dentry, &inode);
2831 if (!err)
2832 ext4_fc_track_create(handle, dentry);
2833 }
2834 if (handle)
2835 ext4_journal_stop(handle);
2836 if (!IS_ERR_OR_NULL(inode))
2837 iput(inode);
2838 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2839 goto retry;
2840 return err;
2841 }
2842
ext4_mknod(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,umode_t mode,dev_t rdev)2843 static int ext4_mknod(struct mnt_idmap *idmap, struct inode *dir,
2844 struct dentry *dentry, umode_t mode, dev_t rdev)
2845 {
2846 handle_t *handle;
2847 struct inode *inode;
2848 int err, credits, retries = 0;
2849
2850 err = dquot_initialize(dir);
2851 if (err)
2852 return err;
2853
2854 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2855 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2856 retry:
2857 inode = ext4_new_inode_start_handle(idmap, dir, mode, &dentry->d_name,
2858 0, NULL, EXT4_HT_DIR, credits);
2859 handle = ext4_journal_current_handle();
2860 err = PTR_ERR(inode);
2861 if (!IS_ERR(inode)) {
2862 init_special_inode(inode, inode->i_mode, rdev);
2863 inode->i_op = &ext4_special_inode_operations;
2864 err = ext4_add_nondir(handle, dentry, &inode);
2865 if (!err)
2866 ext4_fc_track_create(handle, dentry);
2867 }
2868 if (handle)
2869 ext4_journal_stop(handle);
2870 if (!IS_ERR_OR_NULL(inode))
2871 iput(inode);
2872 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2873 goto retry;
2874 return err;
2875 }
2876
ext4_tmpfile(struct mnt_idmap * idmap,struct inode * dir,struct file * file,umode_t mode)2877 static int ext4_tmpfile(struct mnt_idmap *idmap, struct inode *dir,
2878 struct file *file, umode_t mode)
2879 {
2880 handle_t *handle;
2881 struct inode *inode;
2882 int err, retries = 0;
2883
2884 err = dquot_initialize(dir);
2885 if (err)
2886 return err;
2887
2888 retry:
2889 inode = ext4_new_inode_start_handle(idmap, dir, mode,
2890 NULL, 0, NULL,
2891 EXT4_HT_DIR,
2892 EXT4_MAXQUOTAS_TRANS_BLOCKS(dir->i_sb) +
2893 4 + EXT4_XATTR_TRANS_BLOCKS);
2894 handle = ext4_journal_current_handle();
2895 err = PTR_ERR(inode);
2896 if (!IS_ERR(inode)) {
2897 inode->i_op = &ext4_file_inode_operations;
2898 inode->i_fop = &ext4_file_operations;
2899 ext4_set_aops(inode);
2900 d_tmpfile(file, inode);
2901 err = ext4_orphan_add(handle, inode);
2902 if (err)
2903 goto err_unlock_inode;
2904 mark_inode_dirty(inode);
2905 unlock_new_inode(inode);
2906 }
2907 if (handle)
2908 ext4_journal_stop(handle);
2909 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2910 goto retry;
2911 return finish_open_simple(file, err);
2912 err_unlock_inode:
2913 ext4_journal_stop(handle);
2914 unlock_new_inode(inode);
2915 return err;
2916 }
2917
ext4_init_dot_dotdot(struct inode * inode,struct ext4_dir_entry_2 * de,int blocksize,int csum_size,unsigned int parent_ino,int dotdot_real_len)2918 struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
2919 struct ext4_dir_entry_2 *de,
2920 int blocksize, int csum_size,
2921 unsigned int parent_ino, int dotdot_real_len)
2922 {
2923 de->inode = cpu_to_le32(inode->i_ino);
2924 de->name_len = 1;
2925 de->rec_len = ext4_rec_len_to_disk(ext4_dir_rec_len(de->name_len, NULL),
2926 blocksize);
2927 strcpy(de->name, ".");
2928 ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2929
2930 de = ext4_next_entry(de, blocksize);
2931 de->inode = cpu_to_le32(parent_ino);
2932 de->name_len = 2;
2933 if (!dotdot_real_len)
2934 de->rec_len = ext4_rec_len_to_disk(blocksize -
2935 (csum_size + ext4_dir_rec_len(1, NULL)),
2936 blocksize);
2937 else
2938 de->rec_len = ext4_rec_len_to_disk(
2939 ext4_dir_rec_len(de->name_len, NULL),
2940 blocksize);
2941 strcpy(de->name, "..");
2942 ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2943
2944 return ext4_next_entry(de, blocksize);
2945 }
2946
ext4_init_new_dir(handle_t * handle,struct inode * dir,struct inode * inode)2947 int ext4_init_new_dir(handle_t *handle, struct inode *dir,
2948 struct inode *inode)
2949 {
2950 struct buffer_head *dir_block = NULL;
2951 struct ext4_dir_entry_2 *de;
2952 ext4_lblk_t block = 0;
2953 unsigned int blocksize = dir->i_sb->s_blocksize;
2954 int csum_size = 0;
2955 int err;
2956
2957 if (ext4_has_feature_metadata_csum(dir->i_sb))
2958 csum_size = sizeof(struct ext4_dir_entry_tail);
2959
2960 if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
2961 err = ext4_try_create_inline_dir(handle, dir, inode);
2962 if (err < 0 && err != -ENOSPC)
2963 goto out;
2964 if (!err)
2965 goto out;
2966 }
2967
2968 inode->i_size = 0;
2969 dir_block = ext4_append(handle, inode, &block);
2970 if (IS_ERR(dir_block))
2971 return PTR_ERR(dir_block);
2972 de = (struct ext4_dir_entry_2 *)dir_block->b_data;
2973 ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0);
2974 set_nlink(inode, 2);
2975 if (csum_size)
2976 ext4_initialize_dirent_tail(dir_block, blocksize);
2977
2978 BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
2979 err = ext4_handle_dirty_dirblock(handle, inode, dir_block);
2980 if (err)
2981 goto out;
2982 set_buffer_verified(dir_block);
2983 out:
2984 brelse(dir_block);
2985 return err;
2986 }
2987
ext4_mkdir(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,umode_t mode)2988 static struct dentry *ext4_mkdir(struct mnt_idmap *idmap, struct inode *dir,
2989 struct dentry *dentry, umode_t mode)
2990 {
2991 handle_t *handle;
2992 struct inode *inode;
2993 int err, err2 = 0, credits, retries = 0;
2994
2995 if (EXT4_DIR_LINK_MAX(dir))
2996 return ERR_PTR(-EMLINK);
2997
2998 err = dquot_initialize(dir);
2999 if (err)
3000 return ERR_PTR(err);
3001
3002 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3003 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
3004 retry:
3005 inode = ext4_new_inode_start_handle(idmap, dir, S_IFDIR | mode,
3006 &dentry->d_name,
3007 0, NULL, EXT4_HT_DIR, credits);
3008 handle = ext4_journal_current_handle();
3009 err = PTR_ERR(inode);
3010 if (IS_ERR(inode))
3011 goto out_stop;
3012
3013 inode->i_op = &ext4_dir_inode_operations;
3014 inode->i_fop = &ext4_dir_operations;
3015 err = ext4_init_new_dir(handle, dir, inode);
3016 if (err)
3017 goto out_clear_inode;
3018 err = ext4_mark_inode_dirty(handle, inode);
3019 if (!err)
3020 err = ext4_add_entry(handle, dentry, inode);
3021 if (err) {
3022 out_clear_inode:
3023 clear_nlink(inode);
3024 ext4_orphan_add(handle, inode);
3025 unlock_new_inode(inode);
3026 err2 = ext4_mark_inode_dirty(handle, inode);
3027 if (unlikely(err2))
3028 err = err2;
3029 ext4_journal_stop(handle);
3030 iput(inode);
3031 goto out_retry;
3032 }
3033 ext4_inc_count(dir);
3034
3035 ext4_update_dx_flag(dir);
3036 err = ext4_mark_inode_dirty(handle, dir);
3037 if (err)
3038 goto out_clear_inode;
3039 d_instantiate_new(dentry, inode);
3040 ext4_fc_track_create(handle, dentry);
3041 if (IS_DIRSYNC(dir))
3042 ext4_handle_sync(handle);
3043
3044 out_stop:
3045 if (handle)
3046 ext4_journal_stop(handle);
3047 out_retry:
3048 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
3049 goto retry;
3050 return ERR_PTR(err);
3051 }
3052
3053 /*
3054 * routine to check that the specified directory is empty (for rmdir)
3055 */
ext4_empty_dir(struct inode * inode)3056 bool ext4_empty_dir(struct inode *inode)
3057 {
3058 unsigned int offset;
3059 struct buffer_head *bh;
3060 struct ext4_dir_entry_2 *de;
3061 struct super_block *sb;
3062
3063 if (ext4_has_inline_data(inode)) {
3064 int has_inline_data = 1;
3065 int ret;
3066
3067 ret = empty_inline_dir(inode, &has_inline_data);
3068 if (has_inline_data)
3069 return ret;
3070 }
3071
3072 sb = inode->i_sb;
3073 if (inode->i_size < ext4_dir_rec_len(1, NULL) +
3074 ext4_dir_rec_len(2, NULL)) {
3075 EXT4_ERROR_INODE(inode, "invalid size");
3076 return false;
3077 }
3078 bh = ext4_read_dirblock(inode, 0, EITHER);
3079 if (IS_ERR(bh))
3080 return false;
3081
3082 de = (struct ext4_dir_entry_2 *) bh->b_data;
3083 if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, bh->b_size,
3084 0) ||
3085 le32_to_cpu(de->inode) != inode->i_ino || strcmp(".", de->name)) {
3086 ext4_warning_inode(inode, "directory missing '.'");
3087 brelse(bh);
3088 return false;
3089 }
3090 offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
3091 de = ext4_next_entry(de, sb->s_blocksize);
3092 if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, bh->b_size,
3093 offset) ||
3094 le32_to_cpu(de->inode) == 0 || strcmp("..", de->name)) {
3095 ext4_warning_inode(inode, "directory missing '..'");
3096 brelse(bh);
3097 return false;
3098 }
3099 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
3100 while (offset < inode->i_size) {
3101 if (!(offset & (sb->s_blocksize - 1))) {
3102 unsigned int lblock;
3103 brelse(bh);
3104 lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb);
3105 bh = ext4_read_dirblock(inode, lblock, EITHER);
3106 if (bh == NULL) {
3107 offset += sb->s_blocksize;
3108 continue;
3109 }
3110 if (IS_ERR(bh))
3111 return false;
3112 }
3113 de = (struct ext4_dir_entry_2 *) (bh->b_data +
3114 (offset & (sb->s_blocksize - 1)));
3115 if (ext4_check_dir_entry(inode, NULL, de, bh,
3116 bh->b_data, bh->b_size, offset) ||
3117 le32_to_cpu(de->inode)) {
3118 brelse(bh);
3119 return false;
3120 }
3121 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
3122 }
3123 brelse(bh);
3124 return true;
3125 }
3126
ext4_rmdir(struct inode * dir,struct dentry * dentry)3127 static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
3128 {
3129 int retval;
3130 struct inode *inode;
3131 struct buffer_head *bh;
3132 struct ext4_dir_entry_2 *de;
3133 handle_t *handle = NULL;
3134
3135 retval = ext4_emergency_state(dir->i_sb);
3136 if (unlikely(retval))
3137 return retval;
3138
3139 /* Initialize quotas before so that eventual writes go in
3140 * separate transaction */
3141 retval = dquot_initialize(dir);
3142 if (retval)
3143 return retval;
3144 retval = dquot_initialize(d_inode(dentry));
3145 if (retval)
3146 return retval;
3147
3148 retval = -ENOENT;
3149 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
3150 if (IS_ERR(bh))
3151 return PTR_ERR(bh);
3152 if (!bh)
3153 goto end_rmdir;
3154
3155 inode = d_inode(dentry);
3156
3157 retval = -EFSCORRUPTED;
3158 if (le32_to_cpu(de->inode) != inode->i_ino)
3159 goto end_rmdir;
3160
3161 retval = -ENOTEMPTY;
3162 if (!ext4_empty_dir(inode))
3163 goto end_rmdir;
3164
3165 handle = ext4_journal_start(dir, EXT4_HT_DIR,
3166 EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
3167 if (IS_ERR(handle)) {
3168 retval = PTR_ERR(handle);
3169 handle = NULL;
3170 goto end_rmdir;
3171 }
3172
3173 if (IS_DIRSYNC(dir))
3174 ext4_handle_sync(handle);
3175
3176 retval = ext4_delete_entry(handle, dir, de, bh);
3177 if (retval)
3178 goto end_rmdir;
3179 if (!EXT4_DIR_LINK_EMPTY(inode))
3180 ext4_warning_inode(inode,
3181 "empty directory '%.*s' has too many links (%u)",
3182 dentry->d_name.len, dentry->d_name.name,
3183 inode->i_nlink);
3184 inode_inc_iversion(inode);
3185 clear_nlink(inode);
3186 /* There's no need to set i_disksize: the fact that i_nlink is
3187 * zero will ensure that the right thing happens during any
3188 * recovery. */
3189 inode->i_size = 0;
3190 ext4_orphan_add(handle, inode);
3191 inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
3192 inode_set_ctime_current(inode);
3193 retval = ext4_mark_inode_dirty(handle, inode);
3194 if (retval)
3195 goto end_rmdir;
3196 ext4_dec_count(dir);
3197 ext4_update_dx_flag(dir);
3198 ext4_fc_track_unlink(handle, dentry);
3199 retval = ext4_mark_inode_dirty(handle, dir);
3200
3201 /* VFS negative dentries are incompatible with Encoding and
3202 * Case-insensitiveness. Eventually we'll want avoid
3203 * invalidating the dentries here, alongside with returning the
3204 * negative dentries at ext4_lookup(), when it is better
3205 * supported by the VFS for the CI case.
3206 */
3207 if (IS_ENABLED(CONFIG_UNICODE) && IS_CASEFOLDED(dir))
3208 d_invalidate(dentry);
3209
3210 end_rmdir:
3211 brelse(bh);
3212 if (handle)
3213 ext4_journal_stop(handle);
3214 return retval;
3215 }
3216
__ext4_unlink(struct inode * dir,const struct qstr * d_name,struct inode * inode,struct dentry * dentry)3217 int __ext4_unlink(struct inode *dir, const struct qstr *d_name,
3218 struct inode *inode,
3219 struct dentry *dentry /* NULL during fast_commit recovery */)
3220 {
3221 int retval = -ENOENT;
3222 struct buffer_head *bh;
3223 struct ext4_dir_entry_2 *de;
3224 handle_t *handle;
3225 int skip_remove_dentry = 0;
3226
3227 /*
3228 * Keep this outside the transaction; it may have to set up the
3229 * directory's encryption key, which isn't GFP_NOFS-safe.
3230 */
3231 bh = ext4_find_entry(dir, d_name, &de, NULL);
3232 if (IS_ERR(bh))
3233 return PTR_ERR(bh);
3234
3235 if (!bh)
3236 return -ENOENT;
3237
3238 if (le32_to_cpu(de->inode) != inode->i_ino) {
3239 /*
3240 * It's okay if we find dont find dentry which matches
3241 * the inode. That's because it might have gotten
3242 * renamed to a different inode number
3243 */
3244 if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
3245 skip_remove_dentry = 1;
3246 else
3247 goto out_bh;
3248 }
3249
3250 handle = ext4_journal_start(dir, EXT4_HT_DIR,
3251 EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
3252 if (IS_ERR(handle)) {
3253 retval = PTR_ERR(handle);
3254 goto out_bh;
3255 }
3256
3257 if (IS_DIRSYNC(dir))
3258 ext4_handle_sync(handle);
3259
3260 if (!skip_remove_dentry) {
3261 retval = ext4_delete_entry(handle, dir, de, bh);
3262 if (retval)
3263 goto out_handle;
3264 inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
3265 ext4_update_dx_flag(dir);
3266 retval = ext4_mark_inode_dirty(handle, dir);
3267 if (retval)
3268 goto out_handle;
3269 } else {
3270 retval = 0;
3271 }
3272 if (inode->i_nlink == 0)
3273 ext4_warning_inode(inode, "Deleting file '%.*s' with no links",
3274 d_name->len, d_name->name);
3275 else
3276 drop_nlink(inode);
3277 if (!inode->i_nlink)
3278 ext4_orphan_add(handle, inode);
3279 inode_set_ctime_current(inode);
3280 retval = ext4_mark_inode_dirty(handle, inode);
3281 if (dentry && !retval)
3282 ext4_fc_track_unlink(handle, dentry);
3283 out_handle:
3284 ext4_journal_stop(handle);
3285 out_bh:
3286 brelse(bh);
3287 return retval;
3288 }
3289
ext4_unlink(struct inode * dir,struct dentry * dentry)3290 static int ext4_unlink(struct inode *dir, struct dentry *dentry)
3291 {
3292 int retval;
3293
3294 retval = ext4_emergency_state(dir->i_sb);
3295 if (unlikely(retval))
3296 return retval;
3297
3298 trace_ext4_unlink_enter(dir, dentry);
3299 /*
3300 * Initialize quotas before so that eventual writes go
3301 * in separate transaction
3302 */
3303 retval = dquot_initialize(dir);
3304 if (retval)
3305 goto out_trace;
3306 retval = dquot_initialize(d_inode(dentry));
3307 if (retval)
3308 goto out_trace;
3309
3310 retval = __ext4_unlink(dir, &dentry->d_name, d_inode(dentry), dentry);
3311
3312 /* VFS negative dentries are incompatible with Encoding and
3313 * Case-insensitiveness. Eventually we'll want avoid
3314 * invalidating the dentries here, alongside with returning the
3315 * negative dentries at ext4_lookup(), when it is better
3316 * supported by the VFS for the CI case.
3317 */
3318 if (IS_ENABLED(CONFIG_UNICODE) && IS_CASEFOLDED(dir))
3319 d_invalidate(dentry);
3320
3321 out_trace:
3322 trace_ext4_unlink_exit(dentry, retval);
3323 return retval;
3324 }
3325
ext4_init_symlink_block(handle_t * handle,struct inode * inode,struct fscrypt_str * disk_link)3326 static int ext4_init_symlink_block(handle_t *handle, struct inode *inode,
3327 struct fscrypt_str *disk_link)
3328 {
3329 struct buffer_head *bh;
3330 char *kaddr;
3331 int err = 0;
3332
3333 bh = ext4_bread(handle, inode, 0, EXT4_GET_BLOCKS_CREATE);
3334 if (IS_ERR(bh))
3335 return PTR_ERR(bh);
3336
3337 BUFFER_TRACE(bh, "get_write_access");
3338 err = ext4_journal_get_write_access(handle, inode->i_sb, bh, EXT4_JTR_NONE);
3339 if (err)
3340 goto out;
3341
3342 kaddr = (char *)bh->b_data;
3343 memcpy(kaddr, disk_link->name, disk_link->len);
3344 inode->i_size = disk_link->len - 1;
3345 EXT4_I(inode)->i_disksize = inode->i_size;
3346 err = ext4_handle_dirty_metadata(handle, inode, bh);
3347 out:
3348 brelse(bh);
3349 return err;
3350 }
3351
ext4_symlink(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,const char * symname)3352 static int ext4_symlink(struct mnt_idmap *idmap, struct inode *dir,
3353 struct dentry *dentry, const char *symname)
3354 {
3355 handle_t *handle;
3356 struct inode *inode;
3357 int err, len = strlen(symname);
3358 int credits;
3359 struct fscrypt_str disk_link;
3360 int retries = 0;
3361
3362 err = ext4_emergency_state(dir->i_sb);
3363 if (unlikely(err))
3364 return err;
3365
3366 err = fscrypt_prepare_symlink(dir, symname, len, dir->i_sb->s_blocksize,
3367 &disk_link);
3368 if (err)
3369 return err;
3370
3371 err = dquot_initialize(dir);
3372 if (err)
3373 return err;
3374
3375 /*
3376 * EXT4_INDEX_EXTRA_TRANS_BLOCKS for addition of entry into the
3377 * directory. +3 for inode, inode bitmap, group descriptor allocation.
3378 * EXT4_DATA_TRANS_BLOCKS for the data block allocation and
3379 * modification.
3380 */
3381 credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3382 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3;
3383 retry:
3384 inode = ext4_new_inode_start_handle(idmap, dir, S_IFLNK|S_IRWXUGO,
3385 &dentry->d_name, 0, NULL,
3386 EXT4_HT_DIR, credits);
3387 handle = ext4_journal_current_handle();
3388 if (IS_ERR(inode)) {
3389 if (handle)
3390 ext4_journal_stop(handle);
3391 err = PTR_ERR(inode);
3392 goto out_retry;
3393 }
3394
3395 if (IS_ENCRYPTED(inode)) {
3396 err = fscrypt_encrypt_symlink(inode, symname, len, &disk_link);
3397 if (err)
3398 goto err_drop_inode;
3399 inode->i_op = &ext4_encrypted_symlink_inode_operations;
3400 } else {
3401 if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
3402 inode->i_op = &ext4_symlink_inode_operations;
3403 } else {
3404 inode->i_op = &ext4_fast_symlink_inode_operations;
3405 }
3406 }
3407
3408 if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
3409 /* alloc symlink block and fill it */
3410 err = ext4_init_symlink_block(handle, inode, &disk_link);
3411 if (err)
3412 goto err_drop_inode;
3413 } else {
3414 /* clear the extent format for fast symlink */
3415 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
3416 memcpy((char *)&EXT4_I(inode)->i_data, disk_link.name,
3417 disk_link.len);
3418 inode->i_size = disk_link.len - 1;
3419 EXT4_I(inode)->i_disksize = inode->i_size;
3420 if (!IS_ENCRYPTED(inode))
3421 inode_set_cached_link(inode, (char *)&EXT4_I(inode)->i_data,
3422 inode->i_size);
3423 }
3424 err = ext4_add_nondir(handle, dentry, &inode);
3425 if (handle)
3426 ext4_journal_stop(handle);
3427 iput(inode);
3428 goto out_retry;
3429
3430 err_drop_inode:
3431 clear_nlink(inode);
3432 ext4_mark_inode_dirty(handle, inode);
3433 ext4_orphan_add(handle, inode);
3434 unlock_new_inode(inode);
3435 if (handle)
3436 ext4_journal_stop(handle);
3437 iput(inode);
3438 out_retry:
3439 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
3440 goto retry;
3441 if (disk_link.name != (unsigned char *)symname)
3442 kfree(disk_link.name);
3443 return err;
3444 }
3445
__ext4_link(struct inode * dir,struct inode * inode,struct dentry * dentry)3446 int __ext4_link(struct inode *dir, struct inode *inode, struct dentry *dentry)
3447 {
3448 handle_t *handle;
3449 int err, retries = 0;
3450 retry:
3451 handle = ext4_journal_start(dir, EXT4_HT_DIR,
3452 (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3453 EXT4_INDEX_EXTRA_TRANS_BLOCKS) + 1);
3454 if (IS_ERR(handle))
3455 return PTR_ERR(handle);
3456
3457 if (IS_DIRSYNC(dir))
3458 ext4_handle_sync(handle);
3459
3460 inode_set_ctime_current(inode);
3461 ext4_inc_count(inode);
3462 ihold(inode);
3463
3464 err = ext4_add_entry(handle, dentry, inode);
3465 if (!err) {
3466 err = ext4_mark_inode_dirty(handle, inode);
3467 /* this can happen only for tmpfile being
3468 * linked the first time
3469 */
3470 if (inode->i_nlink == 1)
3471 ext4_orphan_del(handle, inode);
3472 d_instantiate(dentry, inode);
3473 ext4_fc_track_link(handle, dentry);
3474 } else {
3475 drop_nlink(inode);
3476 iput(inode);
3477 }
3478 ext4_journal_stop(handle);
3479 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
3480 goto retry;
3481 return err;
3482 }
3483
ext4_link(struct dentry * old_dentry,struct inode * dir,struct dentry * dentry)3484 static int ext4_link(struct dentry *old_dentry,
3485 struct inode *dir, struct dentry *dentry)
3486 {
3487 struct inode *inode = d_inode(old_dentry);
3488 int err;
3489
3490 if (inode->i_nlink >= EXT4_LINK_MAX)
3491 return -EMLINK;
3492
3493 err = fscrypt_prepare_link(old_dentry, dir, dentry);
3494 if (err)
3495 return err;
3496
3497 if ((ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT)) &&
3498 (!projid_eq(EXT4_I(dir)->i_projid,
3499 EXT4_I(old_dentry->d_inode)->i_projid)))
3500 return -EXDEV;
3501
3502 err = dquot_initialize(dir);
3503 if (err)
3504 return err;
3505 return __ext4_link(dir, inode, dentry);
3506 }
3507
3508 /*
3509 * Try to find buffer head where contains the parent block.
3510 * It should be the inode block if it is inlined or the 1st block
3511 * if it is a normal dir.
3512 */
ext4_get_first_dir_block(handle_t * handle,struct inode * inode,int * retval,struct ext4_dir_entry_2 ** parent_de,int * inlined)3513 static struct buffer_head *ext4_get_first_dir_block(handle_t *handle,
3514 struct inode *inode,
3515 int *retval,
3516 struct ext4_dir_entry_2 **parent_de,
3517 int *inlined)
3518 {
3519 struct buffer_head *bh;
3520
3521 if (!ext4_has_inline_data(inode)) {
3522 struct ext4_dir_entry_2 *de;
3523 unsigned int offset;
3524
3525 bh = ext4_read_dirblock(inode, 0, EITHER);
3526 if (IS_ERR(bh)) {
3527 *retval = PTR_ERR(bh);
3528 return NULL;
3529 }
3530
3531 de = (struct ext4_dir_entry_2 *) bh->b_data;
3532 if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data,
3533 bh->b_size, 0) ||
3534 le32_to_cpu(de->inode) != inode->i_ino ||
3535 strcmp(".", de->name)) {
3536 EXT4_ERROR_INODE(inode, "directory missing '.'");
3537 brelse(bh);
3538 *retval = -EFSCORRUPTED;
3539 return NULL;
3540 }
3541 offset = ext4_rec_len_from_disk(de->rec_len,
3542 inode->i_sb->s_blocksize);
3543 de = ext4_next_entry(de, inode->i_sb->s_blocksize);
3544 if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data,
3545 bh->b_size, offset) ||
3546 le32_to_cpu(de->inode) == 0 || strcmp("..", de->name)) {
3547 EXT4_ERROR_INODE(inode, "directory missing '..'");
3548 brelse(bh);
3549 *retval = -EFSCORRUPTED;
3550 return NULL;
3551 }
3552 *parent_de = de;
3553
3554 return bh;
3555 }
3556
3557 *inlined = 1;
3558 return ext4_get_first_inline_block(inode, parent_de, retval);
3559 }
3560
3561 struct ext4_renament {
3562 struct inode *dir;
3563 struct dentry *dentry;
3564 struct inode *inode;
3565 bool is_dir;
3566 int dir_nlink_delta;
3567
3568 /* entry for "dentry" */
3569 struct buffer_head *bh;
3570 struct ext4_dir_entry_2 *de;
3571 int inlined;
3572
3573 /* entry for ".." in inode if it's a directory */
3574 struct buffer_head *dir_bh;
3575 struct ext4_dir_entry_2 *parent_de;
3576 int dir_inlined;
3577 };
3578
ext4_rename_dir_prepare(handle_t * handle,struct ext4_renament * ent,bool is_cross)3579 static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent, bool is_cross)
3580 {
3581 int retval;
3582
3583 ent->is_dir = true;
3584 if (!is_cross)
3585 return 0;
3586
3587 ent->dir_bh = ext4_get_first_dir_block(handle, ent->inode,
3588 &retval, &ent->parent_de,
3589 &ent->dir_inlined);
3590 if (!ent->dir_bh)
3591 return retval;
3592 if (le32_to_cpu(ent->parent_de->inode) != ent->dir->i_ino)
3593 return -EFSCORRUPTED;
3594 BUFFER_TRACE(ent->dir_bh, "get_write_access");
3595 return ext4_journal_get_write_access(handle, ent->dir->i_sb,
3596 ent->dir_bh, EXT4_JTR_NONE);
3597 }
3598
ext4_rename_dir_finish(handle_t * handle,struct ext4_renament * ent,unsigned dir_ino)3599 static int ext4_rename_dir_finish(handle_t *handle, struct ext4_renament *ent,
3600 unsigned dir_ino)
3601 {
3602 int retval;
3603
3604 if (!ent->dir_bh)
3605 return 0;
3606
3607 ent->parent_de->inode = cpu_to_le32(dir_ino);
3608 BUFFER_TRACE(ent->dir_bh, "call ext4_handle_dirty_metadata");
3609 if (!ent->dir_inlined) {
3610 if (is_dx(ent->inode)) {
3611 retval = ext4_handle_dirty_dx_node(handle,
3612 ent->inode,
3613 ent->dir_bh);
3614 } else {
3615 retval = ext4_handle_dirty_dirblock(handle, ent->inode,
3616 ent->dir_bh);
3617 }
3618 } else {
3619 retval = ext4_mark_inode_dirty(handle, ent->inode);
3620 }
3621 if (retval) {
3622 ext4_std_error(ent->dir->i_sb, retval);
3623 return retval;
3624 }
3625 return 0;
3626 }
3627
ext4_setent(handle_t * handle,struct ext4_renament * ent,unsigned ino,unsigned file_type)3628 static int ext4_setent(handle_t *handle, struct ext4_renament *ent,
3629 unsigned ino, unsigned file_type)
3630 {
3631 int retval, retval2;
3632
3633 BUFFER_TRACE(ent->bh, "get write access");
3634 retval = ext4_journal_get_write_access(handle, ent->dir->i_sb, ent->bh,
3635 EXT4_JTR_NONE);
3636 if (retval)
3637 return retval;
3638 ent->de->inode = cpu_to_le32(ino);
3639 if (ext4_has_feature_filetype(ent->dir->i_sb))
3640 ent->de->file_type = file_type;
3641 inode_inc_iversion(ent->dir);
3642 inode_set_mtime_to_ts(ent->dir, inode_set_ctime_current(ent->dir));
3643 retval = ext4_mark_inode_dirty(handle, ent->dir);
3644 BUFFER_TRACE(ent->bh, "call ext4_handle_dirty_metadata");
3645 if (!ent->inlined) {
3646 retval2 = ext4_handle_dirty_dirblock(handle, ent->dir, ent->bh);
3647 if (unlikely(retval2)) {
3648 ext4_std_error(ent->dir->i_sb, retval2);
3649 return retval2;
3650 }
3651 }
3652 return retval;
3653 }
3654
ext4_resetent(handle_t * handle,struct ext4_renament * ent,unsigned ino,unsigned file_type)3655 static void ext4_resetent(handle_t *handle, struct ext4_renament *ent,
3656 unsigned ino, unsigned file_type)
3657 {
3658 struct ext4_renament old = *ent;
3659 int retval = 0;
3660
3661 /*
3662 * old->de could have moved from under us during make indexed dir,
3663 * so the old->de may no longer valid and need to find it again
3664 * before reset old inode info.
3665 */
3666 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de,
3667 &old.inlined);
3668 if (IS_ERR(old.bh))
3669 retval = PTR_ERR(old.bh);
3670 if (!old.bh)
3671 retval = -ENOENT;
3672 if (retval) {
3673 ext4_std_error(old.dir->i_sb, retval);
3674 return;
3675 }
3676
3677 ext4_setent(handle, &old, ino, file_type);
3678 brelse(old.bh);
3679 }
3680
ext4_find_delete_entry(handle_t * handle,struct inode * dir,const struct qstr * d_name)3681 static int ext4_find_delete_entry(handle_t *handle, struct inode *dir,
3682 const struct qstr *d_name)
3683 {
3684 int retval = -ENOENT;
3685 struct buffer_head *bh;
3686 struct ext4_dir_entry_2 *de;
3687
3688 bh = ext4_find_entry(dir, d_name, &de, NULL);
3689 if (IS_ERR(bh))
3690 return PTR_ERR(bh);
3691 if (bh) {
3692 retval = ext4_delete_entry(handle, dir, de, bh);
3693 brelse(bh);
3694 }
3695 return retval;
3696 }
3697
ext4_rename_delete(handle_t * handle,struct ext4_renament * ent,int force_reread)3698 static void ext4_rename_delete(handle_t *handle, struct ext4_renament *ent,
3699 int force_reread)
3700 {
3701 int retval;
3702 /*
3703 * ent->de could have moved from under us during htree split, so make
3704 * sure that we are deleting the right entry. We might also be pointing
3705 * to a stale entry in the unused part of ent->bh so just checking inum
3706 * and the name isn't enough.
3707 */
3708 if (le32_to_cpu(ent->de->inode) != ent->inode->i_ino ||
3709 ent->de->name_len != ent->dentry->d_name.len ||
3710 strncmp(ent->de->name, ent->dentry->d_name.name,
3711 ent->de->name_len) ||
3712 force_reread) {
3713 retval = ext4_find_delete_entry(handle, ent->dir,
3714 &ent->dentry->d_name);
3715 } else {
3716 retval = ext4_delete_entry(handle, ent->dir, ent->de, ent->bh);
3717 if (retval == -ENOENT) {
3718 retval = ext4_find_delete_entry(handle, ent->dir,
3719 &ent->dentry->d_name);
3720 }
3721 }
3722
3723 if (retval) {
3724 ext4_warning_inode(ent->dir,
3725 "Deleting old file: nlink %d, error=%d",
3726 ent->dir->i_nlink, retval);
3727 }
3728 }
3729
ext4_update_dir_count(handle_t * handle,struct ext4_renament * ent)3730 static void ext4_update_dir_count(handle_t *handle, struct ext4_renament *ent)
3731 {
3732 if (ent->dir_nlink_delta) {
3733 if (ent->dir_nlink_delta == -1)
3734 ext4_dec_count(ent->dir);
3735 else
3736 ext4_inc_count(ent->dir);
3737 ext4_mark_inode_dirty(handle, ent->dir);
3738 }
3739 }
3740
ext4_whiteout_for_rename(struct mnt_idmap * idmap,struct ext4_renament * ent,int credits,handle_t ** h)3741 static struct inode *ext4_whiteout_for_rename(struct mnt_idmap *idmap,
3742 struct ext4_renament *ent,
3743 int credits, handle_t **h)
3744 {
3745 struct inode *wh;
3746 handle_t *handle;
3747 int retries = 0;
3748
3749 /*
3750 * for inode block, sb block, group summaries,
3751 * and inode bitmap
3752 */
3753 credits += (EXT4_MAXQUOTAS_TRANS_BLOCKS(ent->dir->i_sb) +
3754 EXT4_XATTR_TRANS_BLOCKS + 4);
3755 retry:
3756 wh = ext4_new_inode_start_handle(idmap, ent->dir,
3757 S_IFCHR | WHITEOUT_MODE,
3758 &ent->dentry->d_name, 0, NULL,
3759 EXT4_HT_DIR, credits);
3760
3761 handle = ext4_journal_current_handle();
3762 if (IS_ERR(wh)) {
3763 if (handle)
3764 ext4_journal_stop(handle);
3765 if (PTR_ERR(wh) == -ENOSPC &&
3766 ext4_should_retry_alloc(ent->dir->i_sb, &retries))
3767 goto retry;
3768 } else {
3769 *h = handle;
3770 init_special_inode(wh, wh->i_mode, WHITEOUT_DEV);
3771 wh->i_op = &ext4_special_inode_operations;
3772 }
3773 return wh;
3774 }
3775
3776 /*
3777 * Anybody can rename anything with this: the permission checks are left to the
3778 * higher-level routines.
3779 *
3780 * n.b. old_{dentry,inode) refers to the source dentry/inode
3781 * while new_{dentry,inode) refers to the destination dentry/inode
3782 * This comes from rename(const char *oldpath, const char *newpath)
3783 */
ext4_rename(struct mnt_idmap * idmap,struct inode * old_dir,struct dentry * old_dentry,struct inode * new_dir,struct dentry * new_dentry,unsigned int flags)3784 static int ext4_rename(struct mnt_idmap *idmap, struct inode *old_dir,
3785 struct dentry *old_dentry, struct inode *new_dir,
3786 struct dentry *new_dentry, unsigned int flags)
3787 {
3788 handle_t *handle = NULL;
3789 struct ext4_renament old = {
3790 .dir = old_dir,
3791 .dentry = old_dentry,
3792 .inode = d_inode(old_dentry),
3793 };
3794 struct ext4_renament new = {
3795 .dir = new_dir,
3796 .dentry = new_dentry,
3797 .inode = d_inode(new_dentry),
3798 };
3799 int force_reread;
3800 int retval;
3801 struct inode *whiteout = NULL;
3802 int credits;
3803 u8 old_file_type;
3804
3805 if (new.inode && new.inode->i_nlink == 0) {
3806 EXT4_ERROR_INODE(new.inode,
3807 "target of rename is already freed");
3808 return -EFSCORRUPTED;
3809 }
3810
3811 if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT)) &&
3812 (!projid_eq(EXT4_I(new_dir)->i_projid,
3813 EXT4_I(old_dentry->d_inode)->i_projid)))
3814 return -EXDEV;
3815
3816 retval = dquot_initialize(old.dir);
3817 if (retval)
3818 return retval;
3819 retval = dquot_initialize(old.inode);
3820 if (retval)
3821 return retval;
3822 retval = dquot_initialize(new.dir);
3823 if (retval)
3824 return retval;
3825
3826 /* Initialize quotas before so that eventual writes go
3827 * in separate transaction */
3828 if (new.inode) {
3829 retval = dquot_initialize(new.inode);
3830 if (retval)
3831 return retval;
3832 }
3833
3834 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de,
3835 &old.inlined);
3836 if (IS_ERR(old.bh))
3837 return PTR_ERR(old.bh);
3838
3839 /*
3840 * Check for inode number is _not_ due to possible IO errors.
3841 * We might rmdir the source, keep it as pwd of some process
3842 * and merrily kill the link to whatever was created under the
3843 * same name. Goodbye sticky bit ;-<
3844 */
3845 retval = -ENOENT;
3846 if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3847 goto release_bh;
3848
3849 new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
3850 &new.de, &new.inlined);
3851 if (IS_ERR(new.bh)) {
3852 retval = PTR_ERR(new.bh);
3853 new.bh = NULL;
3854 goto release_bh;
3855 }
3856 if (new.bh) {
3857 if (!new.inode) {
3858 brelse(new.bh);
3859 new.bh = NULL;
3860 }
3861 }
3862 if (new.inode && !test_opt(new.dir->i_sb, NO_AUTO_DA_ALLOC))
3863 ext4_alloc_da_blocks(old.inode);
3864
3865 credits = (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3866 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
3867 if (!(flags & RENAME_WHITEOUT)) {
3868 handle = ext4_journal_start(old.dir, EXT4_HT_DIR, credits);
3869 if (IS_ERR(handle)) {
3870 retval = PTR_ERR(handle);
3871 goto release_bh;
3872 }
3873 } else {
3874 whiteout = ext4_whiteout_for_rename(idmap, &old, credits, &handle);
3875 if (IS_ERR(whiteout)) {
3876 retval = PTR_ERR(whiteout);
3877 goto release_bh;
3878 }
3879 }
3880
3881 old_file_type = old.de->file_type;
3882 if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3883 ext4_handle_sync(handle);
3884
3885 if (S_ISDIR(old.inode->i_mode)) {
3886 if (new.inode) {
3887 retval = -ENOTEMPTY;
3888 if (!ext4_empty_dir(new.inode))
3889 goto end_rename;
3890 } else {
3891 retval = -EMLINK;
3892 if (new.dir != old.dir && EXT4_DIR_LINK_MAX(new.dir))
3893 goto end_rename;
3894 }
3895 retval = ext4_rename_dir_prepare(handle, &old, new.dir != old.dir);
3896 if (retval)
3897 goto end_rename;
3898 }
3899 /*
3900 * If we're renaming a file within an inline_data dir and adding or
3901 * setting the new dirent causes a conversion from inline_data to
3902 * extents/blockmap, we need to force the dirent delete code to
3903 * re-read the directory, or else we end up trying to delete a dirent
3904 * from what is now the extent tree root (or a block map).
3905 */
3906 force_reread = (new.dir->i_ino == old.dir->i_ino &&
3907 ext4_test_inode_flag(new.dir, EXT4_INODE_INLINE_DATA));
3908
3909 if (whiteout) {
3910 /*
3911 * Do this before adding a new entry, so the old entry is sure
3912 * to be still pointing to the valid old entry.
3913 */
3914 retval = ext4_setent(handle, &old, whiteout->i_ino,
3915 EXT4_FT_CHRDEV);
3916 if (retval)
3917 goto end_rename;
3918 retval = ext4_mark_inode_dirty(handle, whiteout);
3919 if (unlikely(retval))
3920 goto end_rename;
3921
3922 }
3923 if (!new.bh) {
3924 retval = ext4_add_entry(handle, new.dentry, old.inode);
3925 if (retval)
3926 goto end_rename;
3927 } else {
3928 retval = ext4_setent(handle, &new,
3929 old.inode->i_ino, old_file_type);
3930 if (retval)
3931 goto end_rename;
3932 }
3933 if (force_reread)
3934 force_reread = !ext4_test_inode_flag(new.dir,
3935 EXT4_INODE_INLINE_DATA);
3936
3937 /*
3938 * Like most other Unix systems, set the ctime for inodes on a
3939 * rename.
3940 */
3941 inode_set_ctime_current(old.inode);
3942 retval = ext4_mark_inode_dirty(handle, old.inode);
3943 if (unlikely(retval))
3944 goto end_rename;
3945
3946 if (!whiteout) {
3947 /*
3948 * ok, that's it
3949 */
3950 ext4_rename_delete(handle, &old, force_reread);
3951 }
3952
3953 if (new.inode) {
3954 ext4_dec_count(new.inode);
3955 inode_set_ctime_current(new.inode);
3956 }
3957 inode_set_mtime_to_ts(old.dir, inode_set_ctime_current(old.dir));
3958 ext4_update_dx_flag(old.dir);
3959 if (old.is_dir) {
3960 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
3961 if (retval)
3962 goto end_rename;
3963
3964 ext4_dec_count(old.dir);
3965 if (new.inode) {
3966 /* checked ext4_empty_dir above, can't have another
3967 * parent, ext4_dec_count() won't work for many-linked
3968 * dirs */
3969 clear_nlink(new.inode);
3970 } else {
3971 ext4_inc_count(new.dir);
3972 ext4_update_dx_flag(new.dir);
3973 retval = ext4_mark_inode_dirty(handle, new.dir);
3974 if (unlikely(retval))
3975 goto end_rename;
3976 }
3977 }
3978 retval = ext4_mark_inode_dirty(handle, old.dir);
3979 if (unlikely(retval))
3980 goto end_rename;
3981
3982 if (old.is_dir) {
3983 /*
3984 * We disable fast commits here that's because the
3985 * replay code is not yet capable of changing dot dot
3986 * dirents in directories.
3987 */
3988 ext4_fc_mark_ineligible(old.inode->i_sb,
3989 EXT4_FC_REASON_RENAME_DIR, handle);
3990 } else {
3991 struct super_block *sb = old.inode->i_sb;
3992
3993 if (new.inode)
3994 ext4_fc_track_unlink(handle, new.dentry);
3995 if (test_opt2(sb, JOURNAL_FAST_COMMIT) &&
3996 !(EXT4_SB(sb)->s_mount_state & EXT4_FC_REPLAY) &&
3997 !(ext4_test_mount_flag(sb, EXT4_MF_FC_INELIGIBLE))) {
3998 __ext4_fc_track_link(handle, old.inode, new.dentry);
3999 __ext4_fc_track_unlink(handle, old.inode, old.dentry);
4000 if (whiteout)
4001 __ext4_fc_track_create(handle, whiteout,
4002 old.dentry);
4003 }
4004 }
4005
4006 if (new.inode) {
4007 retval = ext4_mark_inode_dirty(handle, new.inode);
4008 if (unlikely(retval))
4009 goto end_rename;
4010 if (!new.inode->i_nlink)
4011 ext4_orphan_add(handle, new.inode);
4012 }
4013 retval = 0;
4014
4015 end_rename:
4016 if (whiteout) {
4017 if (retval) {
4018 ext4_resetent(handle, &old,
4019 old.inode->i_ino, old_file_type);
4020 drop_nlink(whiteout);
4021 ext4_mark_inode_dirty(handle, whiteout);
4022 ext4_orphan_add(handle, whiteout);
4023 }
4024 unlock_new_inode(whiteout);
4025 ext4_journal_stop(handle);
4026 iput(whiteout);
4027 } else {
4028 ext4_journal_stop(handle);
4029 }
4030 release_bh:
4031 brelse(old.dir_bh);
4032 brelse(old.bh);
4033 brelse(new.bh);
4034
4035 return retval;
4036 }
4037
ext4_cross_rename(struct inode * old_dir,struct dentry * old_dentry,struct inode * new_dir,struct dentry * new_dentry)4038 static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
4039 struct inode *new_dir, struct dentry *new_dentry)
4040 {
4041 handle_t *handle = NULL;
4042 struct ext4_renament old = {
4043 .dir = old_dir,
4044 .dentry = old_dentry,
4045 .inode = d_inode(old_dentry),
4046 };
4047 struct ext4_renament new = {
4048 .dir = new_dir,
4049 .dentry = new_dentry,
4050 .inode = d_inode(new_dentry),
4051 };
4052 u8 new_file_type;
4053 int retval;
4054
4055 if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT) &&
4056 !projid_eq(EXT4_I(new_dir)->i_projid,
4057 EXT4_I(old_dentry->d_inode)->i_projid)) ||
4058 (ext4_test_inode_flag(old_dir, EXT4_INODE_PROJINHERIT) &&
4059 !projid_eq(EXT4_I(old_dir)->i_projid,
4060 EXT4_I(new_dentry->d_inode)->i_projid)))
4061 return -EXDEV;
4062
4063 retval = dquot_initialize(old.dir);
4064 if (retval)
4065 return retval;
4066 retval = dquot_initialize(new.dir);
4067 if (retval)
4068 return retval;
4069
4070 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name,
4071 &old.de, &old.inlined);
4072 if (IS_ERR(old.bh))
4073 return PTR_ERR(old.bh);
4074 /*
4075 * Check for inode number is _not_ due to possible IO errors.
4076 * We might rmdir the source, keep it as pwd of some process
4077 * and merrily kill the link to whatever was created under the
4078 * same name. Goodbye sticky bit ;-<
4079 */
4080 retval = -ENOENT;
4081 if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
4082 goto end_rename;
4083
4084 new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
4085 &new.de, &new.inlined);
4086 if (IS_ERR(new.bh)) {
4087 retval = PTR_ERR(new.bh);
4088 new.bh = NULL;
4089 goto end_rename;
4090 }
4091
4092 /* RENAME_EXCHANGE case: old *and* new must both exist */
4093 if (!new.bh || le32_to_cpu(new.de->inode) != new.inode->i_ino)
4094 goto end_rename;
4095
4096 handle = ext4_journal_start(old.dir, EXT4_HT_DIR,
4097 (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
4098 2 * EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2));
4099 if (IS_ERR(handle)) {
4100 retval = PTR_ERR(handle);
4101 handle = NULL;
4102 goto end_rename;
4103 }
4104
4105 if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
4106 ext4_handle_sync(handle);
4107
4108 if (S_ISDIR(old.inode->i_mode)) {
4109 retval = ext4_rename_dir_prepare(handle, &old, new.dir != old.dir);
4110 if (retval)
4111 goto end_rename;
4112 }
4113 if (S_ISDIR(new.inode->i_mode)) {
4114 retval = ext4_rename_dir_prepare(handle, &new, new.dir != old.dir);
4115 if (retval)
4116 goto end_rename;
4117 }
4118
4119 /*
4120 * Other than the special case of overwriting a directory, parents'
4121 * nlink only needs to be modified if this is a cross directory rename.
4122 */
4123 if (old.dir != new.dir && old.is_dir != new.is_dir) {
4124 old.dir_nlink_delta = old.is_dir ? -1 : 1;
4125 new.dir_nlink_delta = -old.dir_nlink_delta;
4126 retval = -EMLINK;
4127 if ((old.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(old.dir)) ||
4128 (new.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(new.dir)))
4129 goto end_rename;
4130 }
4131
4132 new_file_type = new.de->file_type;
4133 retval = ext4_setent(handle, &new, old.inode->i_ino, old.de->file_type);
4134 if (retval)
4135 goto end_rename;
4136
4137 retval = ext4_setent(handle, &old, new.inode->i_ino, new_file_type);
4138 if (retval)
4139 goto end_rename;
4140
4141 /*
4142 * Like most other Unix systems, set the ctime for inodes on a
4143 * rename.
4144 */
4145 inode_set_ctime_current(old.inode);
4146 inode_set_ctime_current(new.inode);
4147 retval = ext4_mark_inode_dirty(handle, old.inode);
4148 if (unlikely(retval))
4149 goto end_rename;
4150 retval = ext4_mark_inode_dirty(handle, new.inode);
4151 if (unlikely(retval))
4152 goto end_rename;
4153 ext4_fc_mark_ineligible(new.inode->i_sb,
4154 EXT4_FC_REASON_CROSS_RENAME, handle);
4155 if (old.dir_bh) {
4156 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
4157 if (retval)
4158 goto end_rename;
4159 }
4160 if (new.dir_bh) {
4161 retval = ext4_rename_dir_finish(handle, &new, old.dir->i_ino);
4162 if (retval)
4163 goto end_rename;
4164 }
4165 ext4_update_dir_count(handle, &old);
4166 ext4_update_dir_count(handle, &new);
4167 retval = 0;
4168
4169 end_rename:
4170 brelse(old.dir_bh);
4171 brelse(new.dir_bh);
4172 brelse(old.bh);
4173 brelse(new.bh);
4174 if (handle)
4175 ext4_journal_stop(handle);
4176 return retval;
4177 }
4178
ext4_rename2(struct mnt_idmap * idmap,struct inode * old_dir,struct dentry * old_dentry,struct inode * new_dir,struct dentry * new_dentry,unsigned int flags)4179 static int ext4_rename2(struct mnt_idmap *idmap,
4180 struct inode *old_dir, struct dentry *old_dentry,
4181 struct inode *new_dir, struct dentry *new_dentry,
4182 unsigned int flags)
4183 {
4184 int err;
4185
4186 err = ext4_emergency_state(old_dir->i_sb);
4187 if (unlikely(err))
4188 return err;
4189
4190 if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
4191 return -EINVAL;
4192
4193 err = fscrypt_prepare_rename(old_dir, old_dentry, new_dir, new_dentry,
4194 flags);
4195 if (err)
4196 return err;
4197
4198 if (flags & RENAME_EXCHANGE) {
4199 return ext4_cross_rename(old_dir, old_dentry,
4200 new_dir, new_dentry);
4201 }
4202
4203 return ext4_rename(idmap, old_dir, old_dentry, new_dir, new_dentry, flags);
4204 }
4205
4206 /*
4207 * directories can handle most operations...
4208 */
4209 const struct inode_operations ext4_dir_inode_operations = {
4210 .create = ext4_create,
4211 .lookup = ext4_lookup,
4212 .link = ext4_link,
4213 .unlink = ext4_unlink,
4214 .symlink = ext4_symlink,
4215 .mkdir = ext4_mkdir,
4216 .rmdir = ext4_rmdir,
4217 .mknod = ext4_mknod,
4218 .tmpfile = ext4_tmpfile,
4219 .rename = ext4_rename2,
4220 .setattr = ext4_setattr,
4221 .getattr = ext4_getattr,
4222 .listxattr = ext4_listxattr,
4223 .get_inode_acl = ext4_get_acl,
4224 .set_acl = ext4_set_acl,
4225 .fiemap = ext4_fiemap,
4226 .fileattr_get = ext4_fileattr_get,
4227 .fileattr_set = ext4_fileattr_set,
4228 };
4229
4230 const struct inode_operations ext4_special_inode_operations = {
4231 .setattr = ext4_setattr,
4232 .getattr = ext4_getattr,
4233 .listxattr = ext4_listxattr,
4234 .get_inode_acl = ext4_get_acl,
4235 .set_acl = ext4_set_acl,
4236 };
4237