1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * linux/fs/ext4/dir.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/dir.c |
13 | * |
14 | * Copyright (C) 1991, 1992 Linus Torvalds |
15 | * |
16 | * ext4 directory handling functions |
17 | * |
18 | * Big-endian to little-endian byte-swapping/bitmaps by |
19 | * David S. Miller (davem@caip.rutgers.edu), 1995 |
20 | * |
21 | * Hash Tree Directory indexing (c) 2001 Daniel Phillips |
22 | * |
23 | */ |
24 | |
25 | #include <linux/fs.h> |
26 | #include <linux/buffer_head.h> |
27 | #include <linux/slab.h> |
28 | #include <linux/iversion.h> |
29 | #include <linux/unicode.h> |
30 | #include "ext4.h" |
31 | #include "xattr.h" |
32 | |
33 | static int ext4_dx_readdir(struct file *, struct dir_context *); |
34 | |
35 | /** |
36 | * is_dx_dir() - check if a directory is using htree indexing |
37 | * @inode: directory inode |
38 | * |
39 | * Check if the given dir-inode refers to an htree-indexed directory |
40 | * (or a directory which could potentially get converted to use htree |
41 | * indexing). |
42 | * |
43 | * Return 1 if it is a dx dir, 0 if not |
44 | */ |
45 | static int is_dx_dir(struct inode *inode) |
46 | { |
47 | struct super_block *sb = inode->i_sb; |
48 | |
49 | if (ext4_has_feature_dir_index(sb: inode->i_sb) && |
50 | ((ext4_test_inode_flag(inode, bit: EXT4_INODE_INDEX)) || |
51 | ((inode->i_size >> sb->s_blocksize_bits) == 1) || |
52 | ext4_has_inline_data(inode))) |
53 | return 1; |
54 | |
55 | return 0; |
56 | } |
57 | |
58 | static bool is_fake_dir_entry(struct ext4_dir_entry_2 *de) |
59 | { |
60 | /* Check if . or .. , or skip if namelen is 0 */ |
61 | if ((de->name_len > 0) && (de->name_len <= 2) && (de->name[0] == '.') && |
62 | (de->name[1] == '.' || de->name[1] == '\0')) |
63 | return true; |
64 | /* Check if this is a csum entry */ |
65 | if (de->file_type == EXT4_FT_DIR_CSUM) |
66 | return true; |
67 | return false; |
68 | } |
69 | |
70 | /* |
71 | * Return 0 if the directory entry is OK, and 1 if there is a problem |
72 | * |
73 | * Note: this is the opposite of what ext2 and ext3 historically returned... |
74 | * |
75 | * bh passed here can be an inode block or a dir data block, depending |
76 | * on the inode inline data flag. |
77 | */ |
78 | int __ext4_check_dir_entry(const char *function, unsigned int line, |
79 | struct inode *dir, struct file *filp, |
80 | struct ext4_dir_entry_2 *de, |
81 | struct buffer_head *bh, char *buf, int size, |
82 | unsigned int offset) |
83 | { |
84 | const char *error_msg = NULL; |
85 | const int rlen = ext4_rec_len_from_disk(dlen: de->rec_len, |
86 | blocksize: dir->i_sb->s_blocksize); |
87 | const int next_offset = ((char *) de - buf) + rlen; |
88 | bool fake = is_fake_dir_entry(de); |
89 | bool has_csum = ext4_has_metadata_csum(sb: dir->i_sb); |
90 | |
91 | if (unlikely(rlen < ext4_dir_rec_len(1, fake ? NULL : dir))) |
92 | error_msg = "rec_len is smaller than minimal" ; |
93 | else if (unlikely(rlen % 4 != 0)) |
94 | error_msg = "rec_len % 4 != 0" ; |
95 | else if (unlikely(rlen < ext4_dir_rec_len(de->name_len, |
96 | fake ? NULL : dir))) |
97 | error_msg = "rec_len is too small for name_len" ; |
98 | else if (unlikely(next_offset > size)) |
99 | error_msg = "directory entry overrun" ; |
100 | else if (unlikely(next_offset > size - ext4_dir_rec_len(1, |
101 | has_csum ? NULL : dir) && |
102 | next_offset != size)) |
103 | error_msg = "directory entry too close to block end" ; |
104 | else if (unlikely(le32_to_cpu(de->inode) > |
105 | le32_to_cpu(EXT4_SB(dir->i_sb)->s_es->s_inodes_count))) |
106 | error_msg = "inode out of bounds" ; |
107 | else |
108 | return 0; |
109 | |
110 | if (filp) |
111 | ext4_error_file(filp, function, line, bh->b_blocknr, |
112 | "bad entry in directory: %s - offset=%u, " |
113 | "inode=%u, rec_len=%d, size=%d fake=%d" , |
114 | error_msg, offset, le32_to_cpu(de->inode), |
115 | rlen, size, fake); |
116 | else |
117 | ext4_error_inode(dir, function, line, bh->b_blocknr, |
118 | "bad entry in directory: %s - offset=%u, " |
119 | "inode=%u, rec_len=%d, size=%d fake=%d" , |
120 | error_msg, offset, le32_to_cpu(de->inode), |
121 | rlen, size, fake); |
122 | |
123 | return 1; |
124 | } |
125 | |
126 | static int ext4_readdir(struct file *file, struct dir_context *ctx) |
127 | { |
128 | unsigned int offset; |
129 | int i; |
130 | struct ext4_dir_entry_2 *de; |
131 | int err; |
132 | struct inode *inode = file_inode(f: file); |
133 | struct super_block *sb = inode->i_sb; |
134 | struct buffer_head *bh = NULL; |
135 | struct fscrypt_str fstr = FSTR_INIT(NULL, 0); |
136 | |
137 | err = fscrypt_prepare_readdir(dir: inode); |
138 | if (err) |
139 | return err; |
140 | |
141 | if (is_dx_dir(inode)) { |
142 | err = ext4_dx_readdir(file, ctx); |
143 | if (err != ERR_BAD_DX_DIR) |
144 | return err; |
145 | |
146 | /* Can we just clear INDEX flag to ignore htree information? */ |
147 | if (!ext4_has_metadata_csum(sb)) { |
148 | /* |
149 | * We don't set the inode dirty flag since it's not |
150 | * critical that it gets flushed back to the disk. |
151 | */ |
152 | ext4_clear_inode_flag(inode, bit: EXT4_INODE_INDEX); |
153 | } |
154 | } |
155 | |
156 | if (ext4_has_inline_data(inode)) { |
157 | int has_inline_data = 1; |
158 | err = ext4_read_inline_dir(filp: file, ctx, |
159 | has_inline_data: &has_inline_data); |
160 | if (has_inline_data) |
161 | return err; |
162 | } |
163 | |
164 | if (IS_ENCRYPTED(inode)) { |
165 | err = fscrypt_fname_alloc_buffer(EXT4_NAME_LEN, crypto_str: &fstr); |
166 | if (err < 0) |
167 | return err; |
168 | } |
169 | |
170 | while (ctx->pos < inode->i_size) { |
171 | struct ext4_map_blocks map; |
172 | |
173 | if (fatal_signal_pending(current)) { |
174 | err = -ERESTARTSYS; |
175 | goto errout; |
176 | } |
177 | cond_resched(); |
178 | offset = ctx->pos & (sb->s_blocksize - 1); |
179 | map.m_lblk = ctx->pos >> EXT4_BLOCK_SIZE_BITS(sb); |
180 | map.m_len = 1; |
181 | err = ext4_map_blocks(NULL, inode, map: &map, flags: 0); |
182 | if (err == 0) { |
183 | /* m_len should never be zero but let's avoid |
184 | * an infinite loop if it somehow is */ |
185 | if (map.m_len == 0) |
186 | map.m_len = 1; |
187 | ctx->pos += map.m_len * sb->s_blocksize; |
188 | continue; |
189 | } |
190 | if (err > 0) { |
191 | pgoff_t index = map.m_pblk >> |
192 | (PAGE_SHIFT - inode->i_blkbits); |
193 | if (!ra_has_index(ra: &file->f_ra, index)) |
194 | page_cache_sync_readahead( |
195 | mapping: sb->s_bdev->bd_inode->i_mapping, |
196 | ra: &file->f_ra, file, |
197 | index, req_count: 1); |
198 | file->f_ra.prev_pos = (loff_t)index << PAGE_SHIFT; |
199 | bh = ext4_bread(NULL, inode, map.m_lblk, 0); |
200 | if (IS_ERR(ptr: bh)) { |
201 | err = PTR_ERR(ptr: bh); |
202 | bh = NULL; |
203 | goto errout; |
204 | } |
205 | } |
206 | |
207 | if (!bh) { |
208 | /* corrupt size? Maybe no more blocks to read */ |
209 | if (ctx->pos > inode->i_blocks << 9) |
210 | break; |
211 | ctx->pos += sb->s_blocksize - offset; |
212 | continue; |
213 | } |
214 | |
215 | /* Check the checksum */ |
216 | if (!buffer_verified(bh) && |
217 | !ext4_dirblock_csum_verify(inode, bh)) { |
218 | EXT4_ERROR_FILE(file, 0, "directory fails checksum " |
219 | "at offset %llu" , |
220 | (unsigned long long)ctx->pos); |
221 | ctx->pos += sb->s_blocksize - offset; |
222 | brelse(bh); |
223 | bh = NULL; |
224 | continue; |
225 | } |
226 | set_buffer_verified(bh); |
227 | |
228 | /* If the dir block has changed since the last call to |
229 | * readdir(2), then we might be pointing to an invalid |
230 | * dirent right now. Scan from the start of the block |
231 | * to make sure. */ |
232 | if (!inode_eq_iversion(inode, old: file->f_version)) { |
233 | for (i = 0; i < sb->s_blocksize && i < offset; ) { |
234 | de = (struct ext4_dir_entry_2 *) |
235 | (bh->b_data + i); |
236 | /* It's too expensive to do a full |
237 | * dirent test each time round this |
238 | * loop, but we do have to test at |
239 | * least that it is non-zero. A |
240 | * failure will be detected in the |
241 | * dirent test below. */ |
242 | if (ext4_rec_len_from_disk(dlen: de->rec_len, |
243 | blocksize: sb->s_blocksize) < ext4_dir_rec_len(name_len: 1, |
244 | dir: inode)) |
245 | break; |
246 | i += ext4_rec_len_from_disk(dlen: de->rec_len, |
247 | blocksize: sb->s_blocksize); |
248 | } |
249 | offset = i; |
250 | ctx->pos = (ctx->pos & ~(sb->s_blocksize - 1)) |
251 | | offset; |
252 | file->f_version = inode_query_iversion(inode); |
253 | } |
254 | |
255 | while (ctx->pos < inode->i_size |
256 | && offset < sb->s_blocksize) { |
257 | de = (struct ext4_dir_entry_2 *) (bh->b_data + offset); |
258 | if (ext4_check_dir_entry(inode, file, de, bh, |
259 | bh->b_data, bh->b_size, |
260 | offset)) { |
261 | /* |
262 | * On error, skip to the next block |
263 | */ |
264 | ctx->pos = (ctx->pos | |
265 | (sb->s_blocksize - 1)) + 1; |
266 | break; |
267 | } |
268 | offset += ext4_rec_len_from_disk(dlen: de->rec_len, |
269 | blocksize: sb->s_blocksize); |
270 | if (le32_to_cpu(de->inode)) { |
271 | if (!IS_ENCRYPTED(inode)) { |
272 | if (!dir_emit(ctx, name: de->name, |
273 | namelen: de->name_len, |
274 | le32_to_cpu(de->inode), |
275 | type: get_dtype(sb, filetype: de->file_type))) |
276 | goto done; |
277 | } else { |
278 | int save_len = fstr.len; |
279 | struct fscrypt_str de_name = |
280 | FSTR_INIT(de->name, |
281 | de->name_len); |
282 | |
283 | /* Directory is encrypted */ |
284 | err = fscrypt_fname_disk_to_usr(inode, |
285 | EXT4_DIRENT_HASH(de), |
286 | EXT4_DIRENT_MINOR_HASH(de), |
287 | iname: &de_name, oname: &fstr); |
288 | de_name = fstr; |
289 | fstr.len = save_len; |
290 | if (err) |
291 | goto errout; |
292 | if (!dir_emit(ctx, |
293 | name: de_name.name, namelen: de_name.len, |
294 | le32_to_cpu(de->inode), |
295 | type: get_dtype(sb, filetype: de->file_type))) |
296 | goto done; |
297 | } |
298 | } |
299 | ctx->pos += ext4_rec_len_from_disk(dlen: de->rec_len, |
300 | blocksize: sb->s_blocksize); |
301 | } |
302 | if ((ctx->pos < inode->i_size) && !dir_relax_shared(inode)) |
303 | goto done; |
304 | brelse(bh); |
305 | bh = NULL; |
306 | } |
307 | done: |
308 | err = 0; |
309 | errout: |
310 | fscrypt_fname_free_buffer(crypto_str: &fstr); |
311 | brelse(bh); |
312 | return err; |
313 | } |
314 | |
315 | static inline int is_32bit_api(void) |
316 | { |
317 | #ifdef CONFIG_COMPAT |
318 | return in_compat_syscall(); |
319 | #else |
320 | return (BITS_PER_LONG == 32); |
321 | #endif |
322 | } |
323 | |
324 | /* |
325 | * These functions convert from the major/minor hash to an f_pos |
326 | * value for dx directories |
327 | * |
328 | * Upper layer (for example NFS) should specify FMODE_32BITHASH or |
329 | * FMODE_64BITHASH explicitly. On the other hand, we allow ext4 to be mounted |
330 | * directly on both 32-bit and 64-bit nodes, under such case, neither |
331 | * FMODE_32BITHASH nor FMODE_64BITHASH is specified. |
332 | */ |
333 | static inline loff_t hash2pos(struct file *filp, __u32 major, __u32 minor) |
334 | { |
335 | if ((filp->f_mode & FMODE_32BITHASH) || |
336 | (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api())) |
337 | return major >> 1; |
338 | else |
339 | return ((__u64)(major >> 1) << 32) | (__u64)minor; |
340 | } |
341 | |
342 | static inline __u32 pos2maj_hash(struct file *filp, loff_t pos) |
343 | { |
344 | if ((filp->f_mode & FMODE_32BITHASH) || |
345 | (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api())) |
346 | return (pos << 1) & 0xffffffff; |
347 | else |
348 | return ((pos >> 32) << 1) & 0xffffffff; |
349 | } |
350 | |
351 | static inline __u32 pos2min_hash(struct file *filp, loff_t pos) |
352 | { |
353 | if ((filp->f_mode & FMODE_32BITHASH) || |
354 | (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api())) |
355 | return 0; |
356 | else |
357 | return pos & 0xffffffff; |
358 | } |
359 | |
360 | /* |
361 | * Return 32- or 64-bit end-of-file for dx directories |
362 | */ |
363 | static inline loff_t ext4_get_htree_eof(struct file *filp) |
364 | { |
365 | if ((filp->f_mode & FMODE_32BITHASH) || |
366 | (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api())) |
367 | return EXT4_HTREE_EOF_32BIT; |
368 | else |
369 | return EXT4_HTREE_EOF_64BIT; |
370 | } |
371 | |
372 | |
373 | /* |
374 | * ext4_dir_llseek() calls generic_file_llseek_size to handle htree |
375 | * directories, where the "offset" is in terms of the filename hash |
376 | * value instead of the byte offset. |
377 | * |
378 | * Because we may return a 64-bit hash that is well beyond offset limits, |
379 | * we need to pass the max hash as the maximum allowable offset in |
380 | * the htree directory case. |
381 | * |
382 | * For non-htree, ext4_llseek already chooses the proper max offset. |
383 | */ |
384 | static loff_t ext4_dir_llseek(struct file *file, loff_t offset, int whence) |
385 | { |
386 | struct inode *inode = file->f_mapping->host; |
387 | int dx_dir = is_dx_dir(inode); |
388 | loff_t ret, htree_max = ext4_get_htree_eof(filp: file); |
389 | |
390 | if (likely(dx_dir)) |
391 | ret = generic_file_llseek_size(file, offset, whence, |
392 | maxsize: htree_max, eof: htree_max); |
393 | else |
394 | ret = ext4_llseek(file, offset, origin: whence); |
395 | file->f_version = inode_peek_iversion(inode) - 1; |
396 | return ret; |
397 | } |
398 | |
399 | /* |
400 | * This structure holds the nodes of the red-black tree used to store |
401 | * the directory entry in hash order. |
402 | */ |
403 | struct fname { |
404 | __u32 hash; |
405 | __u32 minor_hash; |
406 | struct rb_node rb_hash; |
407 | struct fname *next; |
408 | __u32 inode; |
409 | __u8 name_len; |
410 | __u8 file_type; |
411 | char name[]; |
412 | }; |
413 | |
414 | /* |
415 | * This function implements a non-recursive way of freeing all of the |
416 | * nodes in the red-black tree. |
417 | */ |
418 | static void free_rb_tree_fname(struct rb_root *root) |
419 | { |
420 | struct fname *fname, *next; |
421 | |
422 | rbtree_postorder_for_each_entry_safe(fname, next, root, rb_hash) |
423 | while (fname) { |
424 | struct fname *old = fname; |
425 | fname = fname->next; |
426 | kfree(objp: old); |
427 | } |
428 | |
429 | *root = RB_ROOT; |
430 | } |
431 | |
432 | |
433 | static struct dir_private_info *ext4_htree_create_dir_info(struct file *filp, |
434 | loff_t pos) |
435 | { |
436 | struct dir_private_info *p; |
437 | |
438 | p = kzalloc(size: sizeof(*p), GFP_KERNEL); |
439 | if (!p) |
440 | return NULL; |
441 | p->curr_hash = pos2maj_hash(filp, pos); |
442 | p->curr_minor_hash = pos2min_hash(filp, pos); |
443 | return p; |
444 | } |
445 | |
446 | void ext4_htree_free_dir_info(struct dir_private_info *p) |
447 | { |
448 | free_rb_tree_fname(root: &p->root); |
449 | kfree(objp: p); |
450 | } |
451 | |
452 | /* |
453 | * Given a directory entry, enter it into the fname rb tree. |
454 | * |
455 | * When filename encryption is enabled, the dirent will hold the |
456 | * encrypted filename, while the htree will hold decrypted filename. |
457 | * The decrypted filename is passed in via ent_name. parameter. |
458 | */ |
459 | int ext4_htree_store_dirent(struct file *dir_file, __u32 hash, |
460 | __u32 minor_hash, |
461 | struct ext4_dir_entry_2 *dirent, |
462 | struct fscrypt_str *ent_name) |
463 | { |
464 | struct rb_node **p, *parent = NULL; |
465 | struct fname *fname, *new_fn; |
466 | struct dir_private_info *info; |
467 | int len; |
468 | |
469 | info = dir_file->private_data; |
470 | p = &info->root.rb_node; |
471 | |
472 | /* Create and allocate the fname structure */ |
473 | len = sizeof(struct fname) + ent_name->len + 1; |
474 | new_fn = kzalloc(size: len, GFP_KERNEL); |
475 | if (!new_fn) |
476 | return -ENOMEM; |
477 | new_fn->hash = hash; |
478 | new_fn->minor_hash = minor_hash; |
479 | new_fn->inode = le32_to_cpu(dirent->inode); |
480 | new_fn->name_len = ent_name->len; |
481 | new_fn->file_type = dirent->file_type; |
482 | memcpy(new_fn->name, ent_name->name, ent_name->len); |
483 | |
484 | while (*p) { |
485 | parent = *p; |
486 | fname = rb_entry(parent, struct fname, rb_hash); |
487 | |
488 | /* |
489 | * If the hash and minor hash match up, then we put |
490 | * them on a linked list. This rarely happens... |
491 | */ |
492 | if ((new_fn->hash == fname->hash) && |
493 | (new_fn->minor_hash == fname->minor_hash)) { |
494 | new_fn->next = fname->next; |
495 | fname->next = new_fn; |
496 | return 0; |
497 | } |
498 | |
499 | if (new_fn->hash < fname->hash) |
500 | p = &(*p)->rb_left; |
501 | else if (new_fn->hash > fname->hash) |
502 | p = &(*p)->rb_right; |
503 | else if (new_fn->minor_hash < fname->minor_hash) |
504 | p = &(*p)->rb_left; |
505 | else /* if (new_fn->minor_hash > fname->minor_hash) */ |
506 | p = &(*p)->rb_right; |
507 | } |
508 | |
509 | rb_link_node(node: &new_fn->rb_hash, parent, rb_link: p); |
510 | rb_insert_color(&new_fn->rb_hash, &info->root); |
511 | return 0; |
512 | } |
513 | |
514 | |
515 | |
516 | /* |
517 | * This is a helper function for ext4_dx_readdir. It calls filldir |
518 | * for all entries on the fname linked list. (Normally there is only |
519 | * one entry on the linked list, unless there are 62 bit hash collisions.) |
520 | */ |
521 | static int call_filldir(struct file *file, struct dir_context *ctx, |
522 | struct fname *fname) |
523 | { |
524 | struct dir_private_info *info = file->private_data; |
525 | struct inode *inode = file_inode(f: file); |
526 | struct super_block *sb = inode->i_sb; |
527 | |
528 | if (!fname) { |
529 | ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: comm %s: " |
530 | "called with null fname?!?" , __func__, __LINE__, |
531 | inode->i_ino, current->comm); |
532 | return 0; |
533 | } |
534 | ctx->pos = hash2pos(filp: file, major: fname->hash, minor: fname->minor_hash); |
535 | while (fname) { |
536 | if (!dir_emit(ctx, name: fname->name, |
537 | namelen: fname->name_len, |
538 | ino: fname->inode, |
539 | type: get_dtype(sb, filetype: fname->file_type))) { |
540 | info->extra_fname = fname; |
541 | return 1; |
542 | } |
543 | fname = fname->next; |
544 | } |
545 | return 0; |
546 | } |
547 | |
548 | static int ext4_dx_readdir(struct file *file, struct dir_context *ctx) |
549 | { |
550 | struct dir_private_info *info = file->private_data; |
551 | struct inode *inode = file_inode(f: file); |
552 | struct fname *fname; |
553 | int ret = 0; |
554 | |
555 | if (!info) { |
556 | info = ext4_htree_create_dir_info(filp: file, pos: ctx->pos); |
557 | if (!info) |
558 | return -ENOMEM; |
559 | file->private_data = info; |
560 | } |
561 | |
562 | if (ctx->pos == ext4_get_htree_eof(filp: file)) |
563 | return 0; /* EOF */ |
564 | |
565 | /* Some one has messed with f_pos; reset the world */ |
566 | if (info->last_pos != ctx->pos) { |
567 | free_rb_tree_fname(root: &info->root); |
568 | info->curr_node = NULL; |
569 | info->extra_fname = NULL; |
570 | info->curr_hash = pos2maj_hash(filp: file, pos: ctx->pos); |
571 | info->curr_minor_hash = pos2min_hash(filp: file, pos: ctx->pos); |
572 | } |
573 | |
574 | /* |
575 | * If there are any leftover names on the hash collision |
576 | * chain, return them first. |
577 | */ |
578 | if (info->extra_fname) { |
579 | if (call_filldir(file, ctx, fname: info->extra_fname)) |
580 | goto finished; |
581 | info->extra_fname = NULL; |
582 | goto next_node; |
583 | } else if (!info->curr_node) |
584 | info->curr_node = rb_first(&info->root); |
585 | |
586 | while (1) { |
587 | /* |
588 | * Fill the rbtree if we have no more entries, |
589 | * or the inode has changed since we last read in the |
590 | * cached entries. |
591 | */ |
592 | if ((!info->curr_node) || |
593 | !inode_eq_iversion(inode, old: file->f_version)) { |
594 | info->curr_node = NULL; |
595 | free_rb_tree_fname(root: &info->root); |
596 | file->f_version = inode_query_iversion(inode); |
597 | ret = ext4_htree_fill_tree(dir_file: file, start_hash: info->curr_hash, |
598 | start_minor_hash: info->curr_minor_hash, |
599 | next_hash: &info->next_hash); |
600 | if (ret < 0) |
601 | goto finished; |
602 | if (ret == 0) { |
603 | ctx->pos = ext4_get_htree_eof(filp: file); |
604 | break; |
605 | } |
606 | info->curr_node = rb_first(&info->root); |
607 | } |
608 | |
609 | fname = rb_entry(info->curr_node, struct fname, rb_hash); |
610 | info->curr_hash = fname->hash; |
611 | info->curr_minor_hash = fname->minor_hash; |
612 | if (call_filldir(file, ctx, fname)) |
613 | break; |
614 | next_node: |
615 | info->curr_node = rb_next(info->curr_node); |
616 | if (info->curr_node) { |
617 | fname = rb_entry(info->curr_node, struct fname, |
618 | rb_hash); |
619 | info->curr_hash = fname->hash; |
620 | info->curr_minor_hash = fname->minor_hash; |
621 | } else { |
622 | if (info->next_hash == ~0) { |
623 | ctx->pos = ext4_get_htree_eof(filp: file); |
624 | break; |
625 | } |
626 | info->curr_hash = info->next_hash; |
627 | info->curr_minor_hash = 0; |
628 | } |
629 | } |
630 | finished: |
631 | info->last_pos = ctx->pos; |
632 | return ret < 0 ? ret : 0; |
633 | } |
634 | |
635 | static int ext4_release_dir(struct inode *inode, struct file *filp) |
636 | { |
637 | if (filp->private_data) |
638 | ext4_htree_free_dir_info(p: filp->private_data); |
639 | |
640 | return 0; |
641 | } |
642 | |
643 | int ext4_check_all_de(struct inode *dir, struct buffer_head *bh, void *buf, |
644 | int buf_size) |
645 | { |
646 | struct ext4_dir_entry_2 *de; |
647 | int rlen; |
648 | unsigned int offset = 0; |
649 | char *top; |
650 | |
651 | de = buf; |
652 | top = buf + buf_size; |
653 | while ((char *) de < top) { |
654 | if (ext4_check_dir_entry(dir, NULL, de, bh, |
655 | buf, buf_size, offset)) |
656 | return -EFSCORRUPTED; |
657 | rlen = ext4_rec_len_from_disk(dlen: de->rec_len, blocksize: buf_size); |
658 | de = (struct ext4_dir_entry_2 *)((char *)de + rlen); |
659 | offset += rlen; |
660 | } |
661 | if ((char *) de > top) |
662 | return -EFSCORRUPTED; |
663 | |
664 | return 0; |
665 | } |
666 | |
667 | const struct file_operations ext4_dir_operations = { |
668 | .llseek = ext4_dir_llseek, |
669 | .read = generic_read_dir, |
670 | .iterate_shared = ext4_readdir, |
671 | .unlocked_ioctl = ext4_ioctl, |
672 | #ifdef CONFIG_COMPAT |
673 | .compat_ioctl = ext4_compat_ioctl, |
674 | #endif |
675 | .fsync = ext4_sync_file, |
676 | .release = ext4_release_dir, |
677 | }; |
678 | |