Commit | Line | Data |
---|---|---|
ac27a0ec | 1 | /* |
617ba13b | 2 | * linux/fs/ext4/dir.c |
ac27a0ec DK |
3 | * |
4 | * Copyright (C) 1992, 1993, 1994, 1995 | |
5 | * Remy Card (card@masi.ibp.fr) | |
6 | * Laboratoire MASI - Institut Blaise Pascal | |
7 | * Universite Pierre et Marie Curie (Paris VI) | |
8 | * | |
9 | * from | |
10 | * | |
11 | * linux/fs/minix/dir.c | |
12 | * | |
13 | * Copyright (C) 1991, 1992 Linus Torvalds | |
14 | * | |
617ba13b | 15 | * ext4 directory handling functions |
ac27a0ec DK |
16 | * |
17 | * Big-endian to little-endian byte-swapping/bitmaps by | |
18 | * David S. Miller (davem@caip.rutgers.edu), 1995 | |
19 | * | |
20 | * Hash Tree Directory indexing (c) 2001 Daniel Phillips | |
21 | * | |
22 | */ | |
23 | ||
24 | #include <linux/fs.h> | |
ac27a0ec | 25 | #include <linux/buffer_head.h> |
ac27a0ec | 26 | #include <linux/slab.h> |
3dcf5451 | 27 | #include "ext4.h" |
65d165d9 | 28 | #include "xattr.h" |
ac27a0ec | 29 | |
725bebb2 | 30 | static int ext4_dx_readdir(struct file *, struct dir_context *); |
ac27a0ec | 31 | |
d1f5273e FY |
32 | /** |
33 | * Check if the given dir-inode refers to an htree-indexed directory | |
70261f56 | 34 | * (or a directory which could potentially get converted to use htree |
d1f5273e FY |
35 | * indexing). |
36 | * | |
37 | * Return 1 if it is a dx dir, 0 if not | |
38 | */ | |
39 | static int is_dx_dir(struct inode *inode) | |
40 | { | |
41 | struct super_block *sb = inode->i_sb; | |
42 | ||
e2b911c5 | 43 | if (ext4_has_feature_dir_index(inode->i_sb) && |
d1f5273e | 44 | ((ext4_test_inode_flag(inode, EXT4_INODE_INDEX)) || |
8af0f082 TM |
45 | ((inode->i_size >> sb->s_blocksize_bits) == 1) || |
46 | ext4_has_inline_data(inode))) | |
d1f5273e FY |
47 | return 1; |
48 | ||
49 | return 0; | |
50 | } | |
51 | ||
cad3f007 TT |
52 | /* |
53 | * Return 0 if the directory entry is OK, and 1 if there is a problem | |
54 | * | |
55 | * Note: this is the opposite of what ext2 and ext3 historically returned... | |
65d165d9 TM |
56 | * |
57 | * bh passed here can be an inode block or a dir data block, depending | |
58 | * on the inode inline data flag. | |
cad3f007 | 59 | */ |
60fd4da3 | 60 | int __ext4_check_dir_entry(const char *function, unsigned int line, |
f7c21177 | 61 | struct inode *dir, struct file *filp, |
60fd4da3 | 62 | struct ext4_dir_entry_2 *de, |
226ba972 | 63 | struct buffer_head *bh, char *buf, int size, |
60fd4da3 | 64 | unsigned int offset) |
ac27a0ec | 65 | { |
af5bc92d | 66 | const char *error_msg = NULL; |
3d0518f4 WY |
67 | const int rlen = ext4_rec_len_from_disk(de->rec_len, |
68 | dir->i_sb->s_blocksize); | |
ac27a0ec | 69 | |
cad3f007 | 70 | if (unlikely(rlen < EXT4_DIR_REC_LEN(1))) |
ac27a0ec | 71 | error_msg = "rec_len is smaller than minimal"; |
cad3f007 | 72 | else if (unlikely(rlen % 4 != 0)) |
ac27a0ec | 73 | error_msg = "rec_len % 4 != 0"; |
cad3f007 | 74 | else if (unlikely(rlen < EXT4_DIR_REC_LEN(de->name_len))) |
ac27a0ec | 75 | error_msg = "rec_len is too small for name_len"; |
226ba972 TM |
76 | else if (unlikely(((char *) de - buf) + rlen > size)) |
77 | error_msg = "directory entry across range"; | |
cad3f007 TT |
78 | else if (unlikely(le32_to_cpu(de->inode) > |
79 | le32_to_cpu(EXT4_SB(dir->i_sb)->s_es->s_inodes_count))) | |
ac27a0ec | 80 | error_msg = "inode out of bounds"; |
cad3f007 TT |
81 | else |
82 | return 0; | |
83 | ||
f7c21177 | 84 | if (filp) |
4fda4003 | 85 | ext4_error_file(filp, function, line, bh->b_blocknr, |
f7c21177 TT |
86 | "bad entry in directory: %s - offset=%u(%u), " |
87 | "inode=%u, rec_len=%d, name_len=%d", | |
226ba972 | 88 | error_msg, (unsigned) (offset % size), |
f7c21177 TT |
89 | offset, le32_to_cpu(de->inode), |
90 | rlen, de->name_len); | |
91 | else | |
4fda4003 | 92 | ext4_error_inode(dir, function, line, bh->b_blocknr, |
f7c21177 TT |
93 | "bad entry in directory: %s - offset=%u(%u), " |
94 | "inode=%u, rec_len=%d, name_len=%d", | |
226ba972 | 95 | error_msg, (unsigned) (offset % size), |
f7c21177 TT |
96 | offset, le32_to_cpu(de->inode), |
97 | rlen, de->name_len); | |
98 | ||
cad3f007 | 99 | return 1; |
ac27a0ec DK |
100 | } |
101 | ||
725bebb2 | 102 | static int ext4_readdir(struct file *file, struct dir_context *ctx) |
ac27a0ec | 103 | { |
498e5f24 | 104 | unsigned int offset; |
aa13d5f6 | 105 | int i; |
617ba13b | 106 | struct ext4_dir_entry_2 *de; |
ac27a0ec | 107 | int err; |
725bebb2 | 108 | struct inode *inode = file_inode(file); |
d1f5273e | 109 | struct super_block *sb = inode->i_sb; |
44614711 | 110 | struct buffer_head *bh = NULL; |
9d9f1775 | 111 | int dir_has_error = 0; |
44614711 | 112 | struct ext4_str fname_crypto_str = {.name = NULL, .len = 0}; |
ac27a0ec | 113 | |
28b4c263 TT |
114 | if (ext4_encrypted_inode(inode)) { |
115 | err = ext4_get_encryption_info(inode); | |
116 | if (err && err != -ENOKEY) | |
117 | return err; | |
118 | } | |
119 | ||
d1f5273e | 120 | if (is_dx_dir(inode)) { |
725bebb2 | 121 | err = ext4_dx_readdir(file, ctx); |
ac27a0ec | 122 | if (err != ERR_BAD_DX_DIR) { |
725bebb2 | 123 | return err; |
ac27a0ec DK |
124 | } |
125 | /* | |
126 | * We don't set the inode dirty flag since it's not | |
127 | * critical that it get flushed back to the disk. | |
128 | */ | |
725bebb2 | 129 | ext4_clear_inode_flag(file_inode(file), |
07a03824 | 130 | EXT4_INODE_INDEX); |
ac27a0ec | 131 | } |
8af0f082 TM |
132 | |
133 | if (ext4_has_inline_data(inode)) { | |
134 | int has_inline_data = 1; | |
44614711 | 135 | err = ext4_read_inline_dir(file, ctx, |
8af0f082 TM |
136 | &has_inline_data); |
137 | if (has_inline_data) | |
44614711 MH |
138 | return err; |
139 | } | |
140 | ||
b7236e21 TT |
141 | if (ext4_encrypted_inode(inode)) { |
142 | err = ext4_fname_crypto_alloc_buffer(inode, EXT4_NAME_LEN, | |
44614711 | 143 | &fname_crypto_str); |
b7236e21 | 144 | if (err < 0) |
44614711 | 145 | return err; |
8af0f082 TM |
146 | } |
147 | ||
725bebb2 | 148 | offset = ctx->pos & (sb->s_blocksize - 1); |
ac27a0ec | 149 | |
725bebb2 | 150 | while (ctx->pos < inode->i_size) { |
2ed88685 | 151 | struct ext4_map_blocks map; |
ac27a0ec | 152 | |
1f60fbe7 TT |
153 | if (fatal_signal_pending(current)) { |
154 | err = -ERESTARTSYS; | |
155 | goto errout; | |
156 | } | |
157 | cond_resched(); | |
725bebb2 | 158 | map.m_lblk = ctx->pos >> EXT4_BLOCK_SIZE_BITS(sb); |
2ed88685 TT |
159 | map.m_len = 1; |
160 | err = ext4_map_blocks(NULL, inode, &map, 0); | |
ac27a0ec | 161 | if (err > 0) { |
2ed88685 | 162 | pgoff_t index = map.m_pblk >> |
09cbfeaf | 163 | (PAGE_SHIFT - inode->i_blkbits); |
725bebb2 | 164 | if (!ra_has_index(&file->f_ra, index)) |
cf914a7d | 165 | page_cache_sync_readahead( |
dc7868fc | 166 | sb->s_bdev->bd_inode->i_mapping, |
725bebb2 | 167 | &file->f_ra, file, |
cf914a7d | 168 | index, 1); |
09cbfeaf | 169 | file->f_ra.prev_pos = (loff_t)index << PAGE_SHIFT; |
1c215028 | 170 | bh = ext4_bread(NULL, inode, map.m_lblk, 0); |
c906f38e KT |
171 | if (IS_ERR(bh)) { |
172 | err = PTR_ERR(bh); | |
173 | bh = NULL; | |
174 | goto errout; | |
175 | } | |
ac27a0ec DK |
176 | } |
177 | ||
ac27a0ec | 178 | if (!bh) { |
9d9f1775 | 179 | if (!dir_has_error) { |
725bebb2 | 180 | EXT4_ERROR_FILE(file, 0, |
f7c21177 TT |
181 | "directory contains a " |
182 | "hole at offset %llu", | |
725bebb2 | 183 | (unsigned long long) ctx->pos); |
9d9f1775 ES |
184 | dir_has_error = 1; |
185 | } | |
e6c40211 | 186 | /* corrupt size? Maybe no more blocks to read */ |
725bebb2 | 187 | if (ctx->pos > inode->i_blocks << 9) |
e6c40211 | 188 | break; |
725bebb2 | 189 | ctx->pos += sb->s_blocksize - offset; |
ac27a0ec DK |
190 | continue; |
191 | } | |
192 | ||
b0336e8d DW |
193 | /* Check the checksum */ |
194 | if (!buffer_verified(bh) && | |
195 | !ext4_dirent_csum_verify(inode, | |
196 | (struct ext4_dir_entry *)bh->b_data)) { | |
725bebb2 | 197 | EXT4_ERROR_FILE(file, 0, "directory fails checksum " |
b0336e8d | 198 | "at offset %llu", |
725bebb2 AV |
199 | (unsigned long long)ctx->pos); |
200 | ctx->pos += sb->s_blocksize - offset; | |
d5ac7773 | 201 | brelse(bh); |
44614711 | 202 | bh = NULL; |
b0336e8d DW |
203 | continue; |
204 | } | |
205 | set_buffer_verified(bh); | |
206 | ||
ac27a0ec DK |
207 | /* If the dir block has changed since the last call to |
208 | * readdir(2), then we might be pointing to an invalid | |
209 | * dirent right now. Scan from the start of the block | |
210 | * to make sure. */ | |
725bebb2 | 211 | if (file->f_version != inode->i_version) { |
ac27a0ec | 212 | for (i = 0; i < sb->s_blocksize && i < offset; ) { |
617ba13b | 213 | de = (struct ext4_dir_entry_2 *) |
ac27a0ec DK |
214 | (bh->b_data + i); |
215 | /* It's too expensive to do a full | |
216 | * dirent test each time round this | |
217 | * loop, but we do have to test at | |
218 | * least that it is non-zero. A | |
219 | * failure will be detected in the | |
220 | * dirent test below. */ | |
3d0518f4 WY |
221 | if (ext4_rec_len_from_disk(de->rec_len, |
222 | sb->s_blocksize) < EXT4_DIR_REC_LEN(1)) | |
ac27a0ec | 223 | break; |
3d0518f4 WY |
224 | i += ext4_rec_len_from_disk(de->rec_len, |
225 | sb->s_blocksize); | |
ac27a0ec DK |
226 | } |
227 | offset = i; | |
725bebb2 | 228 | ctx->pos = (ctx->pos & ~(sb->s_blocksize - 1)) |
ac27a0ec | 229 | | offset; |
725bebb2 | 230 | file->f_version = inode->i_version; |
ac27a0ec DK |
231 | } |
232 | ||
725bebb2 | 233 | while (ctx->pos < inode->i_size |
ac27a0ec | 234 | && offset < sb->s_blocksize) { |
617ba13b | 235 | de = (struct ext4_dir_entry_2 *) (bh->b_data + offset); |
725bebb2 | 236 | if (ext4_check_dir_entry(inode, file, de, bh, |
226ba972 TM |
237 | bh->b_data, bh->b_size, |
238 | offset)) { | |
63f57933 | 239 | /* |
725bebb2 | 240 | * On error, skip to the next block |
63f57933 | 241 | */ |
725bebb2 | 242 | ctx->pos = (ctx->pos | |
ac27a0ec | 243 | (sb->s_blocksize - 1)) + 1; |
725bebb2 | 244 | break; |
ac27a0ec | 245 | } |
3d0518f4 WY |
246 | offset += ext4_rec_len_from_disk(de->rec_len, |
247 | sb->s_blocksize); | |
ac27a0ec | 248 | if (le32_to_cpu(de->inode)) { |
b7236e21 | 249 | if (!ext4_encrypted_inode(inode)) { |
44614711 MH |
250 | if (!dir_emit(ctx, de->name, |
251 | de->name_len, | |
252 | le32_to_cpu(de->inode), | |
253 | get_dtype(sb, de->file_type))) | |
254 | goto done; | |
255 | } else { | |
d2299590 TT |
256 | int save_len = fname_crypto_str.len; |
257 | ||
44614711 | 258 | /* Directory is encrypted */ |
b7236e21 | 259 | err = ext4_fname_disk_to_usr(inode, |
5de0b4d0 | 260 | NULL, de, &fname_crypto_str); |
d2299590 | 261 | fname_crypto_str.len = save_len; |
44614711 MH |
262 | if (err < 0) |
263 | goto errout; | |
264 | if (!dir_emit(ctx, | |
265 | fname_crypto_str.name, err, | |
266 | le32_to_cpu(de->inode), | |
267 | get_dtype(sb, de->file_type))) | |
268 | goto done; | |
725bebb2 | 269 | } |
ac27a0ec | 270 | } |
725bebb2 | 271 | ctx->pos += ext4_rec_len_from_disk(de->rec_len, |
3d0518f4 | 272 | sb->s_blocksize); |
ac27a0ec | 273 | } |
ae05327a | 274 | if ((ctx->pos < inode->i_size) && !dir_relax_shared(inode)) |
44614711 | 275 | goto done; |
af5bc92d | 276 | brelse(bh); |
44614711 MH |
277 | bh = NULL; |
278 | offset = 0; | |
ac27a0ec | 279 | } |
44614711 MH |
280 | done: |
281 | err = 0; | |
282 | errout: | |
283 | #ifdef CONFIG_EXT4_FS_ENCRYPTION | |
44614711 MH |
284 | ext4_fname_crypto_free_buffer(&fname_crypto_str); |
285 | #endif | |
286 | brelse(bh); | |
287 | return err; | |
ac27a0ec DK |
288 | } |
289 | ||
d1f5273e FY |
290 | static inline int is_32bit_api(void) |
291 | { | |
292 | #ifdef CONFIG_COMPAT | |
121cef8f | 293 | return in_compat_syscall(); |
d1f5273e FY |
294 | #else |
295 | return (BITS_PER_LONG == 32); | |
296 | #endif | |
297 | } | |
298 | ||
ac27a0ec DK |
299 | /* |
300 | * These functions convert from the major/minor hash to an f_pos | |
d1f5273e FY |
301 | * value for dx directories |
302 | * | |
303 | * Upper layer (for example NFS) should specify FMODE_32BITHASH or | |
304 | * FMODE_64BITHASH explicitly. On the other hand, we allow ext4 to be mounted | |
305 | * directly on both 32-bit and 64-bit nodes, under such case, neither | |
306 | * FMODE_32BITHASH nor FMODE_64BITHASH is specified. | |
307 | */ | |
308 | static inline loff_t hash2pos(struct file *filp, __u32 major, __u32 minor) | |
309 | { | |
310 | if ((filp->f_mode & FMODE_32BITHASH) || | |
311 | (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api())) | |
312 | return major >> 1; | |
313 | else | |
314 | return ((__u64)(major >> 1) << 32) | (__u64)minor; | |
315 | } | |
316 | ||
317 | static inline __u32 pos2maj_hash(struct file *filp, loff_t pos) | |
318 | { | |
319 | if ((filp->f_mode & FMODE_32BITHASH) || | |
320 | (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api())) | |
321 | return (pos << 1) & 0xffffffff; | |
322 | else | |
323 | return ((pos >> 32) << 1) & 0xffffffff; | |
324 | } | |
325 | ||
326 | static inline __u32 pos2min_hash(struct file *filp, loff_t pos) | |
327 | { | |
328 | if ((filp->f_mode & FMODE_32BITHASH) || | |
329 | (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api())) | |
330 | return 0; | |
331 | else | |
332 | return pos & 0xffffffff; | |
333 | } | |
334 | ||
335 | /* | |
336 | * Return 32- or 64-bit end-of-file for dx directories | |
337 | */ | |
338 | static inline loff_t ext4_get_htree_eof(struct file *filp) | |
339 | { | |
340 | if ((filp->f_mode & FMODE_32BITHASH) || | |
341 | (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api())) | |
342 | return EXT4_HTREE_EOF_32BIT; | |
343 | else | |
344 | return EXT4_HTREE_EOF_64BIT; | |
345 | } | |
346 | ||
347 | ||
348 | /* | |
ec7268ce ES |
349 | * ext4_dir_llseek() calls generic_file_llseek_size to handle htree |
350 | * directories, where the "offset" is in terms of the filename hash | |
351 | * value instead of the byte offset. | |
ac27a0ec | 352 | * |
ec7268ce ES |
353 | * Because we may return a 64-bit hash that is well beyond offset limits, |
354 | * we need to pass the max hash as the maximum allowable offset in | |
355 | * the htree directory case. | |
356 | * | |
357 | * For non-htree, ext4_llseek already chooses the proper max offset. | |
ac27a0ec | 358 | */ |
d4e43954 | 359 | static loff_t ext4_dir_llseek(struct file *file, loff_t offset, int whence) |
d1f5273e FY |
360 | { |
361 | struct inode *inode = file->f_mapping->host; | |
d1f5273e | 362 | int dx_dir = is_dx_dir(inode); |
ec7268ce | 363 | loff_t htree_max = ext4_get_htree_eof(file); |
d1f5273e | 364 | |
ec7268ce | 365 | if (likely(dx_dir)) |
965c8e59 | 366 | return generic_file_llseek_size(file, offset, whence, |
ec7268ce ES |
367 | htree_max, htree_max); |
368 | else | |
965c8e59 | 369 | return ext4_llseek(file, offset, whence); |
d1f5273e | 370 | } |
ac27a0ec DK |
371 | |
372 | /* | |
373 | * This structure holds the nodes of the red-black tree used to store | |
374 | * the directory entry in hash order. | |
375 | */ | |
376 | struct fname { | |
377 | __u32 hash; | |
378 | __u32 minor_hash; | |
379 | struct rb_node rb_hash; | |
380 | struct fname *next; | |
381 | __u32 inode; | |
382 | __u8 name_len; | |
383 | __u8 file_type; | |
384 | char name[0]; | |
385 | }; | |
386 | ||
387 | /* | |
388 | * This functoin implements a non-recursive way of freeing all of the | |
389 | * nodes in the red-black tree. | |
390 | */ | |
391 | static void free_rb_tree_fname(struct rb_root *root) | |
392 | { | |
d1866bd0 CS |
393 | struct fname *fname, *next; |
394 | ||
395 | rbtree_postorder_for_each_entry_safe(fname, next, root, rb_hash) | |
ac27a0ec | 396 | while (fname) { |
af5bc92d | 397 | struct fname *old = fname; |
ac27a0ec | 398 | fname = fname->next; |
af5bc92d | 399 | kfree(old); |
ac27a0ec | 400 | } |
d1866bd0 CS |
401 | |
402 | *root = RB_ROOT; | |
ac27a0ec DK |
403 | } |
404 | ||
405 | ||
d1f5273e FY |
406 | static struct dir_private_info *ext4_htree_create_dir_info(struct file *filp, |
407 | loff_t pos) | |
ac27a0ec DK |
408 | { |
409 | struct dir_private_info *p; | |
410 | ||
69baee06 | 411 | p = kzalloc(sizeof(struct dir_private_info), GFP_KERNEL); |
ac27a0ec DK |
412 | if (!p) |
413 | return NULL; | |
d1f5273e FY |
414 | p->curr_hash = pos2maj_hash(filp, pos); |
415 | p->curr_minor_hash = pos2min_hash(filp, pos); | |
ac27a0ec DK |
416 | return p; |
417 | } | |
418 | ||
617ba13b | 419 | void ext4_htree_free_dir_info(struct dir_private_info *p) |
ac27a0ec DK |
420 | { |
421 | free_rb_tree_fname(&p->root); | |
422 | kfree(p); | |
423 | } | |
424 | ||
425 | /* | |
426 | * Given a directory entry, enter it into the fname rb tree. | |
2f61830a TT |
427 | * |
428 | * When filename encryption is enabled, the dirent will hold the | |
429 | * encrypted filename, while the htree will hold decrypted filename. | |
430 | * The decrypted filename is passed in via ent_name. parameter. | |
ac27a0ec | 431 | */ |
617ba13b | 432 | int ext4_htree_store_dirent(struct file *dir_file, __u32 hash, |
ac27a0ec | 433 | __u32 minor_hash, |
2f61830a TT |
434 | struct ext4_dir_entry_2 *dirent, |
435 | struct ext4_str *ent_name) | |
ac27a0ec DK |
436 | { |
437 | struct rb_node **p, *parent = NULL; | |
af5bc92d | 438 | struct fname *fname, *new_fn; |
ac27a0ec DK |
439 | struct dir_private_info *info; |
440 | int len; | |
441 | ||
a271fe85 | 442 | info = dir_file->private_data; |
ac27a0ec DK |
443 | p = &info->root.rb_node; |
444 | ||
445 | /* Create and allocate the fname structure */ | |
2f61830a | 446 | len = sizeof(struct fname) + ent_name->len + 1; |
ac27a0ec DK |
447 | new_fn = kzalloc(len, GFP_KERNEL); |
448 | if (!new_fn) | |
449 | return -ENOMEM; | |
450 | new_fn->hash = hash; | |
451 | new_fn->minor_hash = minor_hash; | |
452 | new_fn->inode = le32_to_cpu(dirent->inode); | |
2f61830a | 453 | new_fn->name_len = ent_name->len; |
ac27a0ec | 454 | new_fn->file_type = dirent->file_type; |
2f61830a TT |
455 | memcpy(new_fn->name, ent_name->name, ent_name->len); |
456 | new_fn->name[ent_name->len] = 0; | |
ac27a0ec DK |
457 | |
458 | while (*p) { | |
459 | parent = *p; | |
460 | fname = rb_entry(parent, struct fname, rb_hash); | |
461 | ||
462 | /* | |
463 | * If the hash and minor hash match up, then we put | |
464 | * them on a linked list. This rarely happens... | |
465 | */ | |
466 | if ((new_fn->hash == fname->hash) && | |
467 | (new_fn->minor_hash == fname->minor_hash)) { | |
468 | new_fn->next = fname->next; | |
469 | fname->next = new_fn; | |
470 | return 0; | |
471 | } | |
472 | ||
473 | if (new_fn->hash < fname->hash) | |
474 | p = &(*p)->rb_left; | |
475 | else if (new_fn->hash > fname->hash) | |
476 | p = &(*p)->rb_right; | |
477 | else if (new_fn->minor_hash < fname->minor_hash) | |
478 | p = &(*p)->rb_left; | |
479 | else /* if (new_fn->minor_hash > fname->minor_hash) */ | |
480 | p = &(*p)->rb_right; | |
481 | } | |
482 | ||
483 | rb_link_node(&new_fn->rb_hash, parent, p); | |
484 | rb_insert_color(&new_fn->rb_hash, &info->root); | |
485 | return 0; | |
486 | } | |
487 | ||
488 | ||
489 | ||
490 | /* | |
617ba13b | 491 | * This is a helper function for ext4_dx_readdir. It calls filldir |
ac27a0ec DK |
492 | * for all entres on the fname linked list. (Normally there is only |
493 | * one entry on the linked list, unless there are 62 bit hash collisions.) | |
494 | */ | |
725bebb2 AV |
495 | static int call_filldir(struct file *file, struct dir_context *ctx, |
496 | struct fname *fname) | |
ac27a0ec | 497 | { |
725bebb2 AV |
498 | struct dir_private_info *info = file->private_data; |
499 | struct inode *inode = file_inode(file); | |
500 | struct super_block *sb = inode->i_sb; | |
ac27a0ec DK |
501 | |
502 | if (!fname) { | |
92b97816 TT |
503 | ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: comm %s: " |
504 | "called with null fname?!?", __func__, __LINE__, | |
505 | inode->i_ino, current->comm); | |
ac27a0ec DK |
506 | return 0; |
507 | } | |
725bebb2 | 508 | ctx->pos = hash2pos(file, fname->hash, fname->minor_hash); |
ac27a0ec | 509 | while (fname) { |
725bebb2 AV |
510 | if (!dir_emit(ctx, fname->name, |
511 | fname->name_len, | |
ac27a0ec | 512 | fname->inode, |
725bebb2 | 513 | get_dtype(sb, fname->file_type))) { |
d0156417 | 514 | info->extra_fname = fname; |
725bebb2 | 515 | return 1; |
ac27a0ec DK |
516 | } |
517 | fname = fname->next; | |
518 | } | |
519 | return 0; | |
520 | } | |
521 | ||
725bebb2 | 522 | static int ext4_dx_readdir(struct file *file, struct dir_context *ctx) |
ac27a0ec | 523 | { |
725bebb2 AV |
524 | struct dir_private_info *info = file->private_data; |
525 | struct inode *inode = file_inode(file); | |
ac27a0ec DK |
526 | struct fname *fname; |
527 | int ret; | |
528 | ||
529 | if (!info) { | |
725bebb2 | 530 | info = ext4_htree_create_dir_info(file, ctx->pos); |
ac27a0ec DK |
531 | if (!info) |
532 | return -ENOMEM; | |
725bebb2 | 533 | file->private_data = info; |
ac27a0ec DK |
534 | } |
535 | ||
725bebb2 | 536 | if (ctx->pos == ext4_get_htree_eof(file)) |
ac27a0ec DK |
537 | return 0; /* EOF */ |
538 | ||
539 | /* Some one has messed with f_pos; reset the world */ | |
725bebb2 | 540 | if (info->last_pos != ctx->pos) { |
ac27a0ec DK |
541 | free_rb_tree_fname(&info->root); |
542 | info->curr_node = NULL; | |
543 | info->extra_fname = NULL; | |
725bebb2 AV |
544 | info->curr_hash = pos2maj_hash(file, ctx->pos); |
545 | info->curr_minor_hash = pos2min_hash(file, ctx->pos); | |
ac27a0ec DK |
546 | } |
547 | ||
548 | /* | |
549 | * If there are any leftover names on the hash collision | |
550 | * chain, return them first. | |
551 | */ | |
d0156417 | 552 | if (info->extra_fname) { |
725bebb2 | 553 | if (call_filldir(file, ctx, info->extra_fname)) |
d0156417 | 554 | goto finished; |
d0156417 | 555 | info->extra_fname = NULL; |
3c37fc86 | 556 | goto next_node; |
d0156417 | 557 | } else if (!info->curr_node) |
ac27a0ec DK |
558 | info->curr_node = rb_first(&info->root); |
559 | ||
560 | while (1) { | |
561 | /* | |
562 | * Fill the rbtree if we have no more entries, | |
563 | * or the inode has changed since we last read in the | |
564 | * cached entries. | |
565 | */ | |
566 | if ((!info->curr_node) || | |
725bebb2 | 567 | (file->f_version != inode->i_version)) { |
ac27a0ec DK |
568 | info->curr_node = NULL; |
569 | free_rb_tree_fname(&info->root); | |
725bebb2 AV |
570 | file->f_version = inode->i_version; |
571 | ret = ext4_htree_fill_tree(file, info->curr_hash, | |
ac27a0ec DK |
572 | info->curr_minor_hash, |
573 | &info->next_hash); | |
574 | if (ret < 0) | |
575 | return ret; | |
576 | if (ret == 0) { | |
725bebb2 | 577 | ctx->pos = ext4_get_htree_eof(file); |
ac27a0ec DK |
578 | break; |
579 | } | |
580 | info->curr_node = rb_first(&info->root); | |
581 | } | |
582 | ||
583 | fname = rb_entry(info->curr_node, struct fname, rb_hash); | |
584 | info->curr_hash = fname->hash; | |
585 | info->curr_minor_hash = fname->minor_hash; | |
725bebb2 | 586 | if (call_filldir(file, ctx, fname)) |
ac27a0ec | 587 | break; |
3c37fc86 | 588 | next_node: |
ac27a0ec | 589 | info->curr_node = rb_next(info->curr_node); |
3c37fc86 TT |
590 | if (info->curr_node) { |
591 | fname = rb_entry(info->curr_node, struct fname, | |
592 | rb_hash); | |
593 | info->curr_hash = fname->hash; | |
594 | info->curr_minor_hash = fname->minor_hash; | |
595 | } else { | |
ac27a0ec | 596 | if (info->next_hash == ~0) { |
725bebb2 | 597 | ctx->pos = ext4_get_htree_eof(file); |
ac27a0ec DK |
598 | break; |
599 | } | |
600 | info->curr_hash = info->next_hash; | |
601 | info->curr_minor_hash = 0; | |
602 | } | |
603 | } | |
604 | finished: | |
725bebb2 | 605 | info->last_pos = ctx->pos; |
ac27a0ec DK |
606 | return 0; |
607 | } | |
608 | ||
6bc445e0 TT |
609 | static int ext4_dir_open(struct inode * inode, struct file * filp) |
610 | { | |
611 | if (ext4_encrypted_inode(inode)) | |
612 | return ext4_get_encryption_info(inode) ? -EACCES : 0; | |
613 | return 0; | |
614 | } | |
615 | ||
af5bc92d | 616 | static int ext4_release_dir(struct inode *inode, struct file *filp) |
ac27a0ec | 617 | { |
63f57933 | 618 | if (filp->private_data) |
617ba13b | 619 | ext4_htree_free_dir_info(filp->private_data); |
ac27a0ec DK |
620 | |
621 | return 0; | |
622 | } | |
d1f5273e | 623 | |
40b163f1 DW |
624 | int ext4_check_all_de(struct inode *dir, struct buffer_head *bh, void *buf, |
625 | int buf_size) | |
626 | { | |
627 | struct ext4_dir_entry_2 *de; | |
628 | int nlen, rlen; | |
629 | unsigned int offset = 0; | |
630 | char *top; | |
631 | ||
632 | de = (struct ext4_dir_entry_2 *)buf; | |
633 | top = buf + buf_size; | |
634 | while ((char *) de < top) { | |
635 | if (ext4_check_dir_entry(dir, NULL, de, bh, | |
636 | buf, buf_size, offset)) | |
6a797d27 | 637 | return -EFSCORRUPTED; |
40b163f1 DW |
638 | nlen = EXT4_DIR_REC_LEN(de->name_len); |
639 | rlen = ext4_rec_len_from_disk(de->rec_len, buf_size); | |
640 | de = (struct ext4_dir_entry_2 *)((char *)de + rlen); | |
641 | offset += rlen; | |
642 | } | |
643 | if ((char *) de > top) | |
6a797d27 | 644 | return -EFSCORRUPTED; |
40b163f1 DW |
645 | |
646 | return 0; | |
647 | } | |
648 | ||
d1f5273e FY |
649 | const struct file_operations ext4_dir_operations = { |
650 | .llseek = ext4_dir_llseek, | |
651 | .read = generic_read_dir, | |
ae05327a | 652 | .iterate_shared = ext4_readdir, |
d1f5273e FY |
653 | .unlocked_ioctl = ext4_ioctl, |
654 | #ifdef CONFIG_COMPAT | |
655 | .compat_ioctl = ext4_compat_ioctl, | |
656 | #endif | |
657 | .fsync = ext4_sync_file, | |
6bc445e0 | 658 | .open = ext4_dir_open, |
d1f5273e FY |
659 | .release = ext4_release_dir, |
660 | }; |