Commit | Line | Data |
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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
ac27a0ec | 2 | /* |
617ba13b | 3 | * linux/fs/ext4/dir.c |
ac27a0ec DK |
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 | * | |
617ba13b | 16 | * ext4 directory handling functions |
ac27a0ec DK |
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> | |
ac27a0ec | 26 | #include <linux/buffer_head.h> |
ac27a0ec | 27 | #include <linux/slab.h> |
ee73f9a5 | 28 | #include <linux/iversion.h> |
b886ee3e | 29 | #include <linux/unicode.h> |
3dcf5451 | 30 | #include "ext4.h" |
65d165d9 | 31 | #include "xattr.h" |
ac27a0ec | 32 | |
725bebb2 | 33 | static int ext4_dx_readdir(struct file *, struct dir_context *); |
ac27a0ec | 34 | |
d1f5273e | 35 | /** |
c60990b3 TT |
36 | * is_dx_dir() - check if a directory is using htree indexing |
37 | * @inode: directory inode | |
38 | * | |
d1f5273e | 39 | * Check if the given dir-inode refers to an htree-indexed directory |
70261f56 | 40 | * (or a directory which could potentially get converted to use htree |
d1f5273e FY |
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 | ||
e2b911c5 | 49 | if (ext4_has_feature_dir_index(inode->i_sb) && |
d1f5273e | 50 | ((ext4_test_inode_flag(inode, EXT4_INODE_INDEX)) || |
8af0f082 TM |
51 | ((inode->i_size >> sb->s_blocksize_bits) == 1) || |
52 | ext4_has_inline_data(inode))) | |
d1f5273e FY |
53 | return 1; |
54 | ||
55 | return 0; | |
56 | } | |
57 | ||
cad3f007 TT |
58 | /* |
59 | * Return 0 if the directory entry is OK, and 1 if there is a problem | |
60 | * | |
61 | * Note: this is the opposite of what ext2 and ext3 historically returned... | |
65d165d9 TM |
62 | * |
63 | * bh passed here can be an inode block or a dir data block, depending | |
64 | * on the inode inline data flag. | |
cad3f007 | 65 | */ |
60fd4da3 | 66 | int __ext4_check_dir_entry(const char *function, unsigned int line, |
f7c21177 | 67 | struct inode *dir, struct file *filp, |
60fd4da3 | 68 | struct ext4_dir_entry_2 *de, |
226ba972 | 69 | struct buffer_head *bh, char *buf, int size, |
60fd4da3 | 70 | unsigned int offset) |
ac27a0ec | 71 | { |
af5bc92d | 72 | const char *error_msg = NULL; |
3d0518f4 WY |
73 | const int rlen = ext4_rec_len_from_disk(de->rec_len, |
74 | dir->i_sb->s_blocksize); | |
707d1a2f | 75 | const int next_offset = ((char *) de - buf) + rlen; |
ac27a0ec | 76 | |
cad3f007 | 77 | if (unlikely(rlen < EXT4_DIR_REC_LEN(1))) |
ac27a0ec | 78 | error_msg = "rec_len is smaller than minimal"; |
cad3f007 | 79 | else if (unlikely(rlen % 4 != 0)) |
ac27a0ec | 80 | error_msg = "rec_len % 4 != 0"; |
cad3f007 | 81 | else if (unlikely(rlen < EXT4_DIR_REC_LEN(de->name_len))) |
ac27a0ec | 82 | error_msg = "rec_len is too small for name_len"; |
707d1a2f | 83 | else if (unlikely(next_offset > size)) |
4d982e25 | 84 | error_msg = "directory entry overrun"; |
707d1a2f TT |
85 | else if (unlikely(next_offset > size - EXT4_DIR_REC_LEN(1) && |
86 | next_offset != size)) | |
109ba779 | 87 | error_msg = "directory entry too close to block end"; |
cad3f007 TT |
88 | else if (unlikely(le32_to_cpu(de->inode) > |
89 | le32_to_cpu(EXT4_SB(dir->i_sb)->s_es->s_inodes_count))) | |
ac27a0ec | 90 | error_msg = "inode out of bounds"; |
cad3f007 TT |
91 | else |
92 | return 0; | |
93 | ||
f7c21177 | 94 | if (filp) |
4fda4003 | 95 | ext4_error_file(filp, function, line, bh->b_blocknr, |
4d982e25 TT |
96 | "bad entry in directory: %s - offset=%u, " |
97 | "inode=%u, rec_len=%d, name_len=%d, size=%d", | |
98 | error_msg, offset, le32_to_cpu(de->inode), | |
99 | rlen, de->name_len, size); | |
f7c21177 | 100 | else |
4fda4003 | 101 | ext4_error_inode(dir, function, line, bh->b_blocknr, |
4d982e25 TT |
102 | "bad entry in directory: %s - offset=%u, " |
103 | "inode=%u, rec_len=%d, name_len=%d, size=%d", | |
104 | error_msg, offset, le32_to_cpu(de->inode), | |
105 | rlen, de->name_len, size); | |
f7c21177 | 106 | |
cad3f007 | 107 | return 1; |
ac27a0ec DK |
108 | } |
109 | ||
725bebb2 | 110 | static int ext4_readdir(struct file *file, struct dir_context *ctx) |
ac27a0ec | 111 | { |
498e5f24 | 112 | unsigned int offset; |
aa13d5f6 | 113 | int i; |
617ba13b | 114 | struct ext4_dir_entry_2 *de; |
ac27a0ec | 115 | int err; |
725bebb2 | 116 | struct inode *inode = file_inode(file); |
d1f5273e | 117 | struct super_block *sb = inode->i_sb; |
44614711 | 118 | struct buffer_head *bh = NULL; |
a7550b30 | 119 | struct fscrypt_str fstr = FSTR_INIT(NULL, 0); |
ac27a0ec | 120 | |
592ddec7 | 121 | if (IS_ENCRYPTED(inode)) { |
a7550b30 | 122 | err = fscrypt_get_encryption_info(inode); |
28b4c263 TT |
123 | if (err && err != -ENOKEY) |
124 | return err; | |
125 | } | |
126 | ||
d1f5273e | 127 | if (is_dx_dir(inode)) { |
725bebb2 | 128 | err = ext4_dx_readdir(file, ctx); |
ac27a0ec | 129 | if (err != ERR_BAD_DX_DIR) { |
725bebb2 | 130 | return err; |
ac27a0ec DK |
131 | } |
132 | /* | |
133 | * We don't set the inode dirty flag since it's not | |
134 | * critical that it get flushed back to the disk. | |
135 | */ | |
725bebb2 | 136 | ext4_clear_inode_flag(file_inode(file), |
07a03824 | 137 | EXT4_INODE_INDEX); |
ac27a0ec | 138 | } |
8af0f082 TM |
139 | |
140 | if (ext4_has_inline_data(inode)) { | |
141 | int has_inline_data = 1; | |
44614711 | 142 | err = ext4_read_inline_dir(file, ctx, |
8af0f082 TM |
143 | &has_inline_data); |
144 | if (has_inline_data) | |
44614711 MH |
145 | return err; |
146 | } | |
147 | ||
592ddec7 | 148 | if (IS_ENCRYPTED(inode)) { |
a7550b30 | 149 | err = fscrypt_fname_alloc_buffer(inode, EXT4_NAME_LEN, &fstr); |
b7236e21 | 150 | if (err < 0) |
44614711 | 151 | return err; |
8af0f082 TM |
152 | } |
153 | ||
725bebb2 | 154 | while (ctx->pos < inode->i_size) { |
2ed88685 | 155 | struct ext4_map_blocks map; |
ac27a0ec | 156 | |
1f60fbe7 TT |
157 | if (fatal_signal_pending(current)) { |
158 | err = -ERESTARTSYS; | |
159 | goto errout; | |
160 | } | |
161 | cond_resched(); | |
4e19d6b6 | 162 | offset = ctx->pos & (sb->s_blocksize - 1); |
725bebb2 | 163 | map.m_lblk = ctx->pos >> EXT4_BLOCK_SIZE_BITS(sb); |
2ed88685 TT |
164 | map.m_len = 1; |
165 | err = ext4_map_blocks(NULL, inode, &map, 0); | |
4e19d6b6 TT |
166 | if (err == 0) { |
167 | /* m_len should never be zero but let's avoid | |
168 | * an infinite loop if it somehow is */ | |
169 | if (map.m_len == 0) | |
170 | map.m_len = 1; | |
171 | ctx->pos += map.m_len * sb->s_blocksize; | |
172 | continue; | |
173 | } | |
ac27a0ec | 174 | if (err > 0) { |
2ed88685 | 175 | pgoff_t index = map.m_pblk >> |
09cbfeaf | 176 | (PAGE_SHIFT - inode->i_blkbits); |
725bebb2 | 177 | if (!ra_has_index(&file->f_ra, index)) |
cf914a7d | 178 | page_cache_sync_readahead( |
dc7868fc | 179 | sb->s_bdev->bd_inode->i_mapping, |
725bebb2 | 180 | &file->f_ra, file, |
cf914a7d | 181 | index, 1); |
09cbfeaf | 182 | file->f_ra.prev_pos = (loff_t)index << PAGE_SHIFT; |
1c215028 | 183 | bh = ext4_bread(NULL, inode, map.m_lblk, 0); |
c906f38e KT |
184 | if (IS_ERR(bh)) { |
185 | err = PTR_ERR(bh); | |
186 | bh = NULL; | |
187 | goto errout; | |
188 | } | |
ac27a0ec DK |
189 | } |
190 | ||
ac27a0ec | 191 | if (!bh) { |
e6c40211 | 192 | /* corrupt size? Maybe no more blocks to read */ |
725bebb2 | 193 | if (ctx->pos > inode->i_blocks << 9) |
e6c40211 | 194 | break; |
725bebb2 | 195 | ctx->pos += sb->s_blocksize - offset; |
ac27a0ec DK |
196 | continue; |
197 | } | |
198 | ||
b0336e8d DW |
199 | /* Check the checksum */ |
200 | if (!buffer_verified(bh) && | |
f036adb3 | 201 | !ext4_dirblock_csum_verify(inode, bh)) { |
725bebb2 | 202 | EXT4_ERROR_FILE(file, 0, "directory fails checksum " |
b0336e8d | 203 | "at offset %llu", |
725bebb2 AV |
204 | (unsigned long long)ctx->pos); |
205 | ctx->pos += sb->s_blocksize - offset; | |
d5ac7773 | 206 | brelse(bh); |
44614711 | 207 | bh = NULL; |
b0336e8d DW |
208 | continue; |
209 | } | |
210 | set_buffer_verified(bh); | |
211 | ||
ac27a0ec DK |
212 | /* If the dir block has changed since the last call to |
213 | * readdir(2), then we might be pointing to an invalid | |
214 | * dirent right now. Scan from the start of the block | |
215 | * to make sure. */ | |
c472c07b | 216 | if (!inode_eq_iversion(inode, file->f_version)) { |
ac27a0ec | 217 | for (i = 0; i < sb->s_blocksize && i < offset; ) { |
617ba13b | 218 | de = (struct ext4_dir_entry_2 *) |
ac27a0ec DK |
219 | (bh->b_data + i); |
220 | /* It's too expensive to do a full | |
221 | * dirent test each time round this | |
222 | * loop, but we do have to test at | |
223 | * least that it is non-zero. A | |
224 | * failure will be detected in the | |
225 | * dirent test below. */ | |
3d0518f4 WY |
226 | if (ext4_rec_len_from_disk(de->rec_len, |
227 | sb->s_blocksize) < EXT4_DIR_REC_LEN(1)) | |
ac27a0ec | 228 | break; |
3d0518f4 WY |
229 | i += ext4_rec_len_from_disk(de->rec_len, |
230 | sb->s_blocksize); | |
ac27a0ec DK |
231 | } |
232 | offset = i; | |
725bebb2 | 233 | ctx->pos = (ctx->pos & ~(sb->s_blocksize - 1)) |
ac27a0ec | 234 | | offset; |
ee73f9a5 | 235 | file->f_version = inode_query_iversion(inode); |
ac27a0ec DK |
236 | } |
237 | ||
725bebb2 | 238 | while (ctx->pos < inode->i_size |
ac27a0ec | 239 | && offset < sb->s_blocksize) { |
617ba13b | 240 | de = (struct ext4_dir_entry_2 *) (bh->b_data + offset); |
725bebb2 | 241 | if (ext4_check_dir_entry(inode, file, de, bh, |
226ba972 TM |
242 | bh->b_data, bh->b_size, |
243 | offset)) { | |
63f57933 | 244 | /* |
725bebb2 | 245 | * On error, skip to the next block |
63f57933 | 246 | */ |
725bebb2 | 247 | ctx->pos = (ctx->pos | |
ac27a0ec | 248 | (sb->s_blocksize - 1)) + 1; |
725bebb2 | 249 | break; |
ac27a0ec | 250 | } |
3d0518f4 WY |
251 | offset += ext4_rec_len_from_disk(de->rec_len, |
252 | sb->s_blocksize); | |
ac27a0ec | 253 | if (le32_to_cpu(de->inode)) { |
592ddec7 | 254 | if (!IS_ENCRYPTED(inode)) { |
44614711 MH |
255 | if (!dir_emit(ctx, de->name, |
256 | de->name_len, | |
257 | le32_to_cpu(de->inode), | |
258 | get_dtype(sb, de->file_type))) | |
259 | goto done; | |
260 | } else { | |
a7550b30 JK |
261 | int save_len = fstr.len; |
262 | struct fscrypt_str de_name = | |
263 | FSTR_INIT(de->name, | |
264 | de->name_len); | |
d2299590 | 265 | |
44614711 | 266 | /* Directory is encrypted */ |
a7550b30 JK |
267 | err = fscrypt_fname_disk_to_usr(inode, |
268 | 0, 0, &de_name, &fstr); | |
ef1eb3aa | 269 | de_name = fstr; |
a7550b30 | 270 | fstr.len = save_len; |
ef1eb3aa | 271 | if (err) |
44614711 MH |
272 | goto errout; |
273 | if (!dir_emit(ctx, | |
ef1eb3aa | 274 | de_name.name, de_name.len, |
44614711 MH |
275 | le32_to_cpu(de->inode), |
276 | get_dtype(sb, de->file_type))) | |
277 | goto done; | |
725bebb2 | 278 | } |
ac27a0ec | 279 | } |
725bebb2 | 280 | ctx->pos += ext4_rec_len_from_disk(de->rec_len, |
3d0518f4 | 281 | sb->s_blocksize); |
ac27a0ec | 282 | } |
ae05327a | 283 | if ((ctx->pos < inode->i_size) && !dir_relax_shared(inode)) |
44614711 | 284 | goto done; |
af5bc92d | 285 | brelse(bh); |
44614711 MH |
286 | bh = NULL; |
287 | offset = 0; | |
ac27a0ec | 288 | } |
44614711 MH |
289 | done: |
290 | err = 0; | |
291 | errout: | |
a7550b30 | 292 | fscrypt_fname_free_buffer(&fstr); |
44614711 MH |
293 | brelse(bh); |
294 | return err; | |
ac27a0ec DK |
295 | } |
296 | ||
d1f5273e FY |
297 | static inline int is_32bit_api(void) |
298 | { | |
299 | #ifdef CONFIG_COMPAT | |
121cef8f | 300 | return in_compat_syscall(); |
d1f5273e FY |
301 | #else |
302 | return (BITS_PER_LONG == 32); | |
303 | #endif | |
304 | } | |
305 | ||
ac27a0ec DK |
306 | /* |
307 | * These functions convert from the major/minor hash to an f_pos | |
d1f5273e FY |
308 | * value for dx directories |
309 | * | |
310 | * Upper layer (for example NFS) should specify FMODE_32BITHASH or | |
311 | * FMODE_64BITHASH explicitly. On the other hand, we allow ext4 to be mounted | |
312 | * directly on both 32-bit and 64-bit nodes, under such case, neither | |
313 | * FMODE_32BITHASH nor FMODE_64BITHASH is specified. | |
314 | */ | |
315 | static inline loff_t hash2pos(struct file *filp, __u32 major, __u32 minor) | |
316 | { | |
317 | if ((filp->f_mode & FMODE_32BITHASH) || | |
318 | (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api())) | |
319 | return major >> 1; | |
320 | else | |
321 | return ((__u64)(major >> 1) << 32) | (__u64)minor; | |
322 | } | |
323 | ||
324 | static inline __u32 pos2maj_hash(struct file *filp, loff_t pos) | |
325 | { | |
326 | if ((filp->f_mode & FMODE_32BITHASH) || | |
327 | (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api())) | |
328 | return (pos << 1) & 0xffffffff; | |
329 | else | |
330 | return ((pos >> 32) << 1) & 0xffffffff; | |
331 | } | |
332 | ||
333 | static inline __u32 pos2min_hash(struct file *filp, loff_t pos) | |
334 | { | |
335 | if ((filp->f_mode & FMODE_32BITHASH) || | |
336 | (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api())) | |
337 | return 0; | |
338 | else | |
339 | return pos & 0xffffffff; | |
340 | } | |
341 | ||
342 | /* | |
343 | * Return 32- or 64-bit end-of-file for dx directories | |
344 | */ | |
345 | static inline loff_t ext4_get_htree_eof(struct file *filp) | |
346 | { | |
347 | if ((filp->f_mode & FMODE_32BITHASH) || | |
348 | (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api())) | |
349 | return EXT4_HTREE_EOF_32BIT; | |
350 | else | |
351 | return EXT4_HTREE_EOF_64BIT; | |
352 | } | |
353 | ||
354 | ||
355 | /* | |
ec7268ce ES |
356 | * ext4_dir_llseek() calls generic_file_llseek_size to handle htree |
357 | * directories, where the "offset" is in terms of the filename hash | |
358 | * value instead of the byte offset. | |
ac27a0ec | 359 | * |
ec7268ce ES |
360 | * Because we may return a 64-bit hash that is well beyond offset limits, |
361 | * we need to pass the max hash as the maximum allowable offset in | |
362 | * the htree directory case. | |
363 | * | |
364 | * For non-htree, ext4_llseek already chooses the proper max offset. | |
ac27a0ec | 365 | */ |
d4e43954 | 366 | static loff_t ext4_dir_llseek(struct file *file, loff_t offset, int whence) |
d1f5273e FY |
367 | { |
368 | struct inode *inode = file->f_mapping->host; | |
d1f5273e | 369 | int dx_dir = is_dx_dir(inode); |
e40ff213 | 370 | loff_t ret, htree_max = ext4_get_htree_eof(file); |
d1f5273e | 371 | |
ec7268ce | 372 | if (likely(dx_dir)) |
e40ff213 | 373 | ret = generic_file_llseek_size(file, offset, whence, |
ec7268ce ES |
374 | htree_max, htree_max); |
375 | else | |
e40ff213 TT |
376 | ret = ext4_llseek(file, offset, whence); |
377 | file->f_version = inode_peek_iversion(inode) - 1; | |
378 | return ret; | |
d1f5273e | 379 | } |
ac27a0ec DK |
380 | |
381 | /* | |
382 | * This structure holds the nodes of the red-black tree used to store | |
383 | * the directory entry in hash order. | |
384 | */ | |
385 | struct fname { | |
386 | __u32 hash; | |
387 | __u32 minor_hash; | |
388 | struct rb_node rb_hash; | |
389 | struct fname *next; | |
390 | __u32 inode; | |
391 | __u8 name_len; | |
392 | __u8 file_type; | |
393 | char name[0]; | |
394 | }; | |
395 | ||
396 | /* | |
397 | * This functoin implements a non-recursive way of freeing all of the | |
398 | * nodes in the red-black tree. | |
399 | */ | |
400 | static void free_rb_tree_fname(struct rb_root *root) | |
401 | { | |
d1866bd0 CS |
402 | struct fname *fname, *next; |
403 | ||
404 | rbtree_postorder_for_each_entry_safe(fname, next, root, rb_hash) | |
ac27a0ec | 405 | while (fname) { |
af5bc92d | 406 | struct fname *old = fname; |
ac27a0ec | 407 | fname = fname->next; |
af5bc92d | 408 | kfree(old); |
ac27a0ec | 409 | } |
d1866bd0 CS |
410 | |
411 | *root = RB_ROOT; | |
ac27a0ec DK |
412 | } |
413 | ||
414 | ||
d1f5273e FY |
415 | static struct dir_private_info *ext4_htree_create_dir_info(struct file *filp, |
416 | loff_t pos) | |
ac27a0ec DK |
417 | { |
418 | struct dir_private_info *p; | |
419 | ||
d695a1be | 420 | p = kzalloc(sizeof(*p), GFP_KERNEL); |
ac27a0ec DK |
421 | if (!p) |
422 | return NULL; | |
d1f5273e FY |
423 | p->curr_hash = pos2maj_hash(filp, pos); |
424 | p->curr_minor_hash = pos2min_hash(filp, pos); | |
ac27a0ec DK |
425 | return p; |
426 | } | |
427 | ||
617ba13b | 428 | void ext4_htree_free_dir_info(struct dir_private_info *p) |
ac27a0ec DK |
429 | { |
430 | free_rb_tree_fname(&p->root); | |
431 | kfree(p); | |
432 | } | |
433 | ||
434 | /* | |
435 | * Given a directory entry, enter it into the fname rb tree. | |
2f61830a TT |
436 | * |
437 | * When filename encryption is enabled, the dirent will hold the | |
438 | * encrypted filename, while the htree will hold decrypted filename. | |
439 | * The decrypted filename is passed in via ent_name. parameter. | |
ac27a0ec | 440 | */ |
617ba13b | 441 | int ext4_htree_store_dirent(struct file *dir_file, __u32 hash, |
ac27a0ec | 442 | __u32 minor_hash, |
2f61830a | 443 | struct ext4_dir_entry_2 *dirent, |
a7550b30 | 444 | struct fscrypt_str *ent_name) |
ac27a0ec DK |
445 | { |
446 | struct rb_node **p, *parent = NULL; | |
af5bc92d | 447 | struct fname *fname, *new_fn; |
ac27a0ec DK |
448 | struct dir_private_info *info; |
449 | int len; | |
450 | ||
a271fe85 | 451 | info = dir_file->private_data; |
ac27a0ec DK |
452 | p = &info->root.rb_node; |
453 | ||
454 | /* Create and allocate the fname structure */ | |
2f61830a | 455 | len = sizeof(struct fname) + ent_name->len + 1; |
ac27a0ec DK |
456 | new_fn = kzalloc(len, GFP_KERNEL); |
457 | if (!new_fn) | |
458 | return -ENOMEM; | |
459 | new_fn->hash = hash; | |
460 | new_fn->minor_hash = minor_hash; | |
461 | new_fn->inode = le32_to_cpu(dirent->inode); | |
2f61830a | 462 | new_fn->name_len = ent_name->len; |
ac27a0ec | 463 | new_fn->file_type = dirent->file_type; |
2f61830a TT |
464 | memcpy(new_fn->name, ent_name->name, ent_name->len); |
465 | new_fn->name[ent_name->len] = 0; | |
ac27a0ec DK |
466 | |
467 | while (*p) { | |
468 | parent = *p; | |
469 | fname = rb_entry(parent, struct fname, rb_hash); | |
470 | ||
471 | /* | |
472 | * If the hash and minor hash match up, then we put | |
473 | * them on a linked list. This rarely happens... | |
474 | */ | |
475 | if ((new_fn->hash == fname->hash) && | |
476 | (new_fn->minor_hash == fname->minor_hash)) { | |
477 | new_fn->next = fname->next; | |
478 | fname->next = new_fn; | |
479 | return 0; | |
480 | } | |
481 | ||
482 | if (new_fn->hash < fname->hash) | |
483 | p = &(*p)->rb_left; | |
484 | else if (new_fn->hash > fname->hash) | |
485 | p = &(*p)->rb_right; | |
486 | else if (new_fn->minor_hash < fname->minor_hash) | |
487 | p = &(*p)->rb_left; | |
488 | else /* if (new_fn->minor_hash > fname->minor_hash) */ | |
489 | p = &(*p)->rb_right; | |
490 | } | |
491 | ||
492 | rb_link_node(&new_fn->rb_hash, parent, p); | |
493 | rb_insert_color(&new_fn->rb_hash, &info->root); | |
494 | return 0; | |
495 | } | |
496 | ||
497 | ||
498 | ||
499 | /* | |
617ba13b | 500 | * This is a helper function for ext4_dx_readdir. It calls filldir |
ac27a0ec DK |
501 | * for all entres on the fname linked list. (Normally there is only |
502 | * one entry on the linked list, unless there are 62 bit hash collisions.) | |
503 | */ | |
725bebb2 AV |
504 | static int call_filldir(struct file *file, struct dir_context *ctx, |
505 | struct fname *fname) | |
ac27a0ec | 506 | { |
725bebb2 AV |
507 | struct dir_private_info *info = file->private_data; |
508 | struct inode *inode = file_inode(file); | |
509 | struct super_block *sb = inode->i_sb; | |
ac27a0ec DK |
510 | |
511 | if (!fname) { | |
92b97816 TT |
512 | ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: comm %s: " |
513 | "called with null fname?!?", __func__, __LINE__, | |
514 | inode->i_ino, current->comm); | |
ac27a0ec DK |
515 | return 0; |
516 | } | |
725bebb2 | 517 | ctx->pos = hash2pos(file, fname->hash, fname->minor_hash); |
ac27a0ec | 518 | while (fname) { |
725bebb2 AV |
519 | if (!dir_emit(ctx, fname->name, |
520 | fname->name_len, | |
ac27a0ec | 521 | fname->inode, |
725bebb2 | 522 | get_dtype(sb, fname->file_type))) { |
d0156417 | 523 | info->extra_fname = fname; |
725bebb2 | 524 | return 1; |
ac27a0ec DK |
525 | } |
526 | fname = fname->next; | |
527 | } | |
528 | return 0; | |
529 | } | |
530 | ||
725bebb2 | 531 | static int ext4_dx_readdir(struct file *file, struct dir_context *ctx) |
ac27a0ec | 532 | { |
725bebb2 AV |
533 | struct dir_private_info *info = file->private_data; |
534 | struct inode *inode = file_inode(file); | |
ac27a0ec DK |
535 | struct fname *fname; |
536 | int ret; | |
537 | ||
538 | if (!info) { | |
725bebb2 | 539 | info = ext4_htree_create_dir_info(file, ctx->pos); |
ac27a0ec DK |
540 | if (!info) |
541 | return -ENOMEM; | |
725bebb2 | 542 | file->private_data = info; |
ac27a0ec DK |
543 | } |
544 | ||
725bebb2 | 545 | if (ctx->pos == ext4_get_htree_eof(file)) |
ac27a0ec DK |
546 | return 0; /* EOF */ |
547 | ||
548 | /* Some one has messed with f_pos; reset the world */ | |
725bebb2 | 549 | if (info->last_pos != ctx->pos) { |
ac27a0ec DK |
550 | free_rb_tree_fname(&info->root); |
551 | info->curr_node = NULL; | |
552 | info->extra_fname = NULL; | |
725bebb2 AV |
553 | info->curr_hash = pos2maj_hash(file, ctx->pos); |
554 | info->curr_minor_hash = pos2min_hash(file, ctx->pos); | |
ac27a0ec DK |
555 | } |
556 | ||
557 | /* | |
558 | * If there are any leftover names on the hash collision | |
559 | * chain, return them first. | |
560 | */ | |
d0156417 | 561 | if (info->extra_fname) { |
725bebb2 | 562 | if (call_filldir(file, ctx, info->extra_fname)) |
d0156417 | 563 | goto finished; |
d0156417 | 564 | info->extra_fname = NULL; |
3c37fc86 | 565 | goto next_node; |
d0156417 | 566 | } else if (!info->curr_node) |
ac27a0ec DK |
567 | info->curr_node = rb_first(&info->root); |
568 | ||
569 | while (1) { | |
570 | /* | |
571 | * Fill the rbtree if we have no more entries, | |
572 | * or the inode has changed since we last read in the | |
573 | * cached entries. | |
574 | */ | |
575 | if ((!info->curr_node) || | |
c472c07b | 576 | !inode_eq_iversion(inode, file->f_version)) { |
ac27a0ec DK |
577 | info->curr_node = NULL; |
578 | free_rb_tree_fname(&info->root); | |
ee73f9a5 | 579 | file->f_version = inode_query_iversion(inode); |
725bebb2 | 580 | ret = ext4_htree_fill_tree(file, info->curr_hash, |
ac27a0ec DK |
581 | info->curr_minor_hash, |
582 | &info->next_hash); | |
583 | if (ret < 0) | |
584 | return ret; | |
585 | if (ret == 0) { | |
725bebb2 | 586 | ctx->pos = ext4_get_htree_eof(file); |
ac27a0ec DK |
587 | break; |
588 | } | |
589 | info->curr_node = rb_first(&info->root); | |
590 | } | |
591 | ||
592 | fname = rb_entry(info->curr_node, struct fname, rb_hash); | |
593 | info->curr_hash = fname->hash; | |
594 | info->curr_minor_hash = fname->minor_hash; | |
725bebb2 | 595 | if (call_filldir(file, ctx, fname)) |
ac27a0ec | 596 | break; |
3c37fc86 | 597 | next_node: |
ac27a0ec | 598 | info->curr_node = rb_next(info->curr_node); |
3c37fc86 TT |
599 | if (info->curr_node) { |
600 | fname = rb_entry(info->curr_node, struct fname, | |
601 | rb_hash); | |
602 | info->curr_hash = fname->hash; | |
603 | info->curr_minor_hash = fname->minor_hash; | |
604 | } else { | |
ac27a0ec | 605 | if (info->next_hash == ~0) { |
725bebb2 | 606 | ctx->pos = ext4_get_htree_eof(file); |
ac27a0ec DK |
607 | break; |
608 | } | |
609 | info->curr_hash = info->next_hash; | |
610 | info->curr_minor_hash = 0; | |
611 | } | |
612 | } | |
613 | finished: | |
725bebb2 | 614 | info->last_pos = ctx->pos; |
ac27a0ec DK |
615 | return 0; |
616 | } | |
617 | ||
6bc445e0 TT |
618 | static int ext4_dir_open(struct inode * inode, struct file * filp) |
619 | { | |
592ddec7 | 620 | if (IS_ENCRYPTED(inode)) |
a7550b30 | 621 | return fscrypt_get_encryption_info(inode) ? -EACCES : 0; |
6bc445e0 TT |
622 | return 0; |
623 | } | |
624 | ||
af5bc92d | 625 | static int ext4_release_dir(struct inode *inode, struct file *filp) |
ac27a0ec | 626 | { |
63f57933 | 627 | if (filp->private_data) |
617ba13b | 628 | ext4_htree_free_dir_info(filp->private_data); |
ac27a0ec DK |
629 | |
630 | return 0; | |
631 | } | |
d1f5273e | 632 | |
40b163f1 DW |
633 | int ext4_check_all_de(struct inode *dir, struct buffer_head *bh, void *buf, |
634 | int buf_size) | |
635 | { | |
636 | struct ext4_dir_entry_2 *de; | |
18017479 | 637 | int rlen; |
40b163f1 DW |
638 | unsigned int offset = 0; |
639 | char *top; | |
640 | ||
641 | de = (struct ext4_dir_entry_2 *)buf; | |
642 | top = buf + buf_size; | |
643 | while ((char *) de < top) { | |
644 | if (ext4_check_dir_entry(dir, NULL, de, bh, | |
645 | buf, buf_size, offset)) | |
6a797d27 | 646 | return -EFSCORRUPTED; |
40b163f1 DW |
647 | rlen = ext4_rec_len_from_disk(de->rec_len, buf_size); |
648 | de = (struct ext4_dir_entry_2 *)((char *)de + rlen); | |
649 | offset += rlen; | |
650 | } | |
651 | if ((char *) de > top) | |
6a797d27 | 652 | return -EFSCORRUPTED; |
40b163f1 DW |
653 | |
654 | return 0; | |
655 | } | |
656 | ||
d1f5273e FY |
657 | const struct file_operations ext4_dir_operations = { |
658 | .llseek = ext4_dir_llseek, | |
659 | .read = generic_read_dir, | |
ae05327a | 660 | .iterate_shared = ext4_readdir, |
d1f5273e FY |
661 | .unlocked_ioctl = ext4_ioctl, |
662 | #ifdef CONFIG_COMPAT | |
663 | .compat_ioctl = ext4_compat_ioctl, | |
664 | #endif | |
665 | .fsync = ext4_sync_file, | |
6bc445e0 | 666 | .open = ext4_dir_open, |
d1f5273e FY |
667 | .release = ext4_release_dir, |
668 | }; | |
b886ee3e GKB |
669 | |
670 | #ifdef CONFIG_UNICODE | |
671 | static int ext4_d_compare(const struct dentry *dentry, unsigned int len, | |
672 | const char *str, const struct qstr *name) | |
673 | { | |
674 | struct qstr qstr = {.name = str, .len = len }; | |
6456ca65 | 675 | struct inode *inode = dentry->d_parent->d_inode; |
b886ee3e | 676 | |
6456ca65 | 677 | if (!IS_CASEFOLDED(inode) || !EXT4_SB(inode->i_sb)->s_encoding) { |
b886ee3e GKB |
678 | if (len != name->len) |
679 | return -1; | |
66883da1 | 680 | return memcmp(str, name->name, len); |
b886ee3e GKB |
681 | } |
682 | ||
6456ca65 | 683 | return ext4_ci_compare(inode, name, &qstr, false); |
b886ee3e GKB |
684 | } |
685 | ||
686 | static int ext4_d_hash(const struct dentry *dentry, struct qstr *str) | |
687 | { | |
688 | const struct ext4_sb_info *sbi = EXT4_SB(dentry->d_sb); | |
689 | const struct unicode_map *um = sbi->s_encoding; | |
690 | unsigned char *norm; | |
691 | int len, ret = 0; | |
692 | ||
6456ca65 | 693 | if (!IS_CASEFOLDED(dentry->d_inode) || !um) |
b886ee3e GKB |
694 | return 0; |
695 | ||
696 | norm = kmalloc(PATH_MAX, GFP_ATOMIC); | |
697 | if (!norm) | |
698 | return -ENOMEM; | |
699 | ||
700 | len = utf8_casefold(um, str, norm, PATH_MAX); | |
701 | if (len < 0) { | |
702 | if (ext4_has_strict_mode(sbi)) | |
703 | ret = -EINVAL; | |
704 | goto out; | |
705 | } | |
706 | str->hash = full_name_hash(dentry, norm, len); | |
707 | out: | |
708 | kfree(norm); | |
709 | return ret; | |
710 | } | |
711 | ||
712 | const struct dentry_operations ext4_dentry_ops = { | |
713 | .d_hash = ext4_d_hash, | |
714 | .d_compare = ext4_d_compare, | |
715 | }; | |
716 | #endif |