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 | |
725bebb2 | 153 | map.m_lblk = ctx->pos >> EXT4_BLOCK_SIZE_BITS(sb); |
2ed88685 TT |
154 | map.m_len = 1; |
155 | err = ext4_map_blocks(NULL, inode, &map, 0); | |
ac27a0ec | 156 | if (err > 0) { |
2ed88685 | 157 | pgoff_t index = map.m_pblk >> |
09cbfeaf | 158 | (PAGE_SHIFT - inode->i_blkbits); |
725bebb2 | 159 | if (!ra_has_index(&file->f_ra, index)) |
cf914a7d | 160 | page_cache_sync_readahead( |
dc7868fc | 161 | sb->s_bdev->bd_inode->i_mapping, |
725bebb2 | 162 | &file->f_ra, file, |
cf914a7d | 163 | index, 1); |
09cbfeaf | 164 | file->f_ra.prev_pos = (loff_t)index << PAGE_SHIFT; |
1c215028 | 165 | bh = ext4_bread(NULL, inode, map.m_lblk, 0); |
c906f38e KT |
166 | if (IS_ERR(bh)) { |
167 | err = PTR_ERR(bh); | |
168 | bh = NULL; | |
169 | goto errout; | |
170 | } | |
ac27a0ec DK |
171 | } |
172 | ||
ac27a0ec | 173 | if (!bh) { |
9d9f1775 | 174 | if (!dir_has_error) { |
725bebb2 | 175 | EXT4_ERROR_FILE(file, 0, |
f7c21177 TT |
176 | "directory contains a " |
177 | "hole at offset %llu", | |
725bebb2 | 178 | (unsigned long long) ctx->pos); |
9d9f1775 ES |
179 | dir_has_error = 1; |
180 | } | |
e6c40211 | 181 | /* corrupt size? Maybe no more blocks to read */ |
725bebb2 | 182 | if (ctx->pos > inode->i_blocks << 9) |
e6c40211 | 183 | break; |
725bebb2 | 184 | ctx->pos += sb->s_blocksize - offset; |
ac27a0ec DK |
185 | continue; |
186 | } | |
187 | ||
b0336e8d DW |
188 | /* Check the checksum */ |
189 | if (!buffer_verified(bh) && | |
190 | !ext4_dirent_csum_verify(inode, | |
191 | (struct ext4_dir_entry *)bh->b_data)) { | |
725bebb2 | 192 | EXT4_ERROR_FILE(file, 0, "directory fails checksum " |
b0336e8d | 193 | "at offset %llu", |
725bebb2 AV |
194 | (unsigned long long)ctx->pos); |
195 | ctx->pos += sb->s_blocksize - offset; | |
d5ac7773 | 196 | brelse(bh); |
44614711 | 197 | bh = NULL; |
b0336e8d DW |
198 | continue; |
199 | } | |
200 | set_buffer_verified(bh); | |
201 | ||
ac27a0ec DK |
202 | /* If the dir block has changed since the last call to |
203 | * readdir(2), then we might be pointing to an invalid | |
204 | * dirent right now. Scan from the start of the block | |
205 | * to make sure. */ | |
725bebb2 | 206 | if (file->f_version != inode->i_version) { |
ac27a0ec | 207 | for (i = 0; i < sb->s_blocksize && i < offset; ) { |
617ba13b | 208 | de = (struct ext4_dir_entry_2 *) |
ac27a0ec DK |
209 | (bh->b_data + i); |
210 | /* It's too expensive to do a full | |
211 | * dirent test each time round this | |
212 | * loop, but we do have to test at | |
213 | * least that it is non-zero. A | |
214 | * failure will be detected in the | |
215 | * dirent test below. */ | |
3d0518f4 WY |
216 | if (ext4_rec_len_from_disk(de->rec_len, |
217 | sb->s_blocksize) < EXT4_DIR_REC_LEN(1)) | |
ac27a0ec | 218 | break; |
3d0518f4 WY |
219 | i += ext4_rec_len_from_disk(de->rec_len, |
220 | sb->s_blocksize); | |
ac27a0ec DK |
221 | } |
222 | offset = i; | |
725bebb2 | 223 | ctx->pos = (ctx->pos & ~(sb->s_blocksize - 1)) |
ac27a0ec | 224 | | offset; |
725bebb2 | 225 | file->f_version = inode->i_version; |
ac27a0ec DK |
226 | } |
227 | ||
725bebb2 | 228 | while (ctx->pos < inode->i_size |
ac27a0ec | 229 | && offset < sb->s_blocksize) { |
617ba13b | 230 | de = (struct ext4_dir_entry_2 *) (bh->b_data + offset); |
725bebb2 | 231 | if (ext4_check_dir_entry(inode, file, de, bh, |
226ba972 TM |
232 | bh->b_data, bh->b_size, |
233 | offset)) { | |
63f57933 | 234 | /* |
725bebb2 | 235 | * On error, skip to the next block |
63f57933 | 236 | */ |
725bebb2 | 237 | ctx->pos = (ctx->pos | |
ac27a0ec | 238 | (sb->s_blocksize - 1)) + 1; |
725bebb2 | 239 | break; |
ac27a0ec | 240 | } |
3d0518f4 WY |
241 | offset += ext4_rec_len_from_disk(de->rec_len, |
242 | sb->s_blocksize); | |
ac27a0ec | 243 | if (le32_to_cpu(de->inode)) { |
b7236e21 | 244 | if (!ext4_encrypted_inode(inode)) { |
44614711 MH |
245 | if (!dir_emit(ctx, de->name, |
246 | de->name_len, | |
247 | le32_to_cpu(de->inode), | |
248 | get_dtype(sb, de->file_type))) | |
249 | goto done; | |
250 | } else { | |
d2299590 TT |
251 | int save_len = fname_crypto_str.len; |
252 | ||
44614711 | 253 | /* Directory is encrypted */ |
b7236e21 | 254 | err = ext4_fname_disk_to_usr(inode, |
5de0b4d0 | 255 | NULL, de, &fname_crypto_str); |
d2299590 | 256 | fname_crypto_str.len = save_len; |
44614711 MH |
257 | if (err < 0) |
258 | goto errout; | |
259 | if (!dir_emit(ctx, | |
260 | fname_crypto_str.name, err, | |
261 | le32_to_cpu(de->inode), | |
262 | get_dtype(sb, de->file_type))) | |
263 | goto done; | |
725bebb2 | 264 | } |
ac27a0ec | 265 | } |
725bebb2 | 266 | ctx->pos += ext4_rec_len_from_disk(de->rec_len, |
3d0518f4 | 267 | sb->s_blocksize); |
ac27a0ec | 268 | } |
44614711 MH |
269 | if ((ctx->pos < inode->i_size) && !dir_relax(inode)) |
270 | goto done; | |
af5bc92d | 271 | brelse(bh); |
44614711 MH |
272 | bh = NULL; |
273 | offset = 0; | |
ac27a0ec | 274 | } |
44614711 MH |
275 | done: |
276 | err = 0; | |
277 | errout: | |
278 | #ifdef CONFIG_EXT4_FS_ENCRYPTION | |
44614711 MH |
279 | ext4_fname_crypto_free_buffer(&fname_crypto_str); |
280 | #endif | |
281 | brelse(bh); | |
282 | return err; | |
ac27a0ec DK |
283 | } |
284 | ||
d1f5273e FY |
285 | static inline int is_32bit_api(void) |
286 | { | |
287 | #ifdef CONFIG_COMPAT | |
121cef8f | 288 | return in_compat_syscall(); |
d1f5273e FY |
289 | #else |
290 | return (BITS_PER_LONG == 32); | |
291 | #endif | |
292 | } | |
293 | ||
ac27a0ec DK |
294 | /* |
295 | * These functions convert from the major/minor hash to an f_pos | |
d1f5273e FY |
296 | * value for dx directories |
297 | * | |
298 | * Upper layer (for example NFS) should specify FMODE_32BITHASH or | |
299 | * FMODE_64BITHASH explicitly. On the other hand, we allow ext4 to be mounted | |
300 | * directly on both 32-bit and 64-bit nodes, under such case, neither | |
301 | * FMODE_32BITHASH nor FMODE_64BITHASH is specified. | |
302 | */ | |
303 | static inline loff_t hash2pos(struct file *filp, __u32 major, __u32 minor) | |
304 | { | |
305 | if ((filp->f_mode & FMODE_32BITHASH) || | |
306 | (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api())) | |
307 | return major >> 1; | |
308 | else | |
309 | return ((__u64)(major >> 1) << 32) | (__u64)minor; | |
310 | } | |
311 | ||
312 | static inline __u32 pos2maj_hash(struct file *filp, loff_t pos) | |
313 | { | |
314 | if ((filp->f_mode & FMODE_32BITHASH) || | |
315 | (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api())) | |
316 | return (pos << 1) & 0xffffffff; | |
317 | else | |
318 | return ((pos >> 32) << 1) & 0xffffffff; | |
319 | } | |
320 | ||
321 | static inline __u32 pos2min_hash(struct file *filp, loff_t pos) | |
322 | { | |
323 | if ((filp->f_mode & FMODE_32BITHASH) || | |
324 | (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api())) | |
325 | return 0; | |
326 | else | |
327 | return pos & 0xffffffff; | |
328 | } | |
329 | ||
330 | /* | |
331 | * Return 32- or 64-bit end-of-file for dx directories | |
332 | */ | |
333 | static inline loff_t ext4_get_htree_eof(struct file *filp) | |
334 | { | |
335 | if ((filp->f_mode & FMODE_32BITHASH) || | |
336 | (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api())) | |
337 | return EXT4_HTREE_EOF_32BIT; | |
338 | else | |
339 | return EXT4_HTREE_EOF_64BIT; | |
340 | } | |
341 | ||
342 | ||
343 | /* | |
ec7268ce ES |
344 | * ext4_dir_llseek() calls generic_file_llseek_size to handle htree |
345 | * directories, where the "offset" is in terms of the filename hash | |
346 | * value instead of the byte offset. | |
ac27a0ec | 347 | * |
ec7268ce ES |
348 | * Because we may return a 64-bit hash that is well beyond offset limits, |
349 | * we need to pass the max hash as the maximum allowable offset in | |
350 | * the htree directory case. | |
351 | * | |
352 | * For non-htree, ext4_llseek already chooses the proper max offset. | |
ac27a0ec | 353 | */ |
d4e43954 | 354 | static loff_t ext4_dir_llseek(struct file *file, loff_t offset, int whence) |
d1f5273e FY |
355 | { |
356 | struct inode *inode = file->f_mapping->host; | |
d1f5273e | 357 | int dx_dir = is_dx_dir(inode); |
ec7268ce | 358 | loff_t htree_max = ext4_get_htree_eof(file); |
d1f5273e | 359 | |
ec7268ce | 360 | if (likely(dx_dir)) |
965c8e59 | 361 | return generic_file_llseek_size(file, offset, whence, |
ec7268ce ES |
362 | htree_max, htree_max); |
363 | else | |
965c8e59 | 364 | return ext4_llseek(file, offset, whence); |
d1f5273e | 365 | } |
ac27a0ec DK |
366 | |
367 | /* | |
368 | * This structure holds the nodes of the red-black tree used to store | |
369 | * the directory entry in hash order. | |
370 | */ | |
371 | struct fname { | |
372 | __u32 hash; | |
373 | __u32 minor_hash; | |
374 | struct rb_node rb_hash; | |
375 | struct fname *next; | |
376 | __u32 inode; | |
377 | __u8 name_len; | |
378 | __u8 file_type; | |
379 | char name[0]; | |
380 | }; | |
381 | ||
382 | /* | |
383 | * This functoin implements a non-recursive way of freeing all of the | |
384 | * nodes in the red-black tree. | |
385 | */ | |
386 | static void free_rb_tree_fname(struct rb_root *root) | |
387 | { | |
d1866bd0 CS |
388 | struct fname *fname, *next; |
389 | ||
390 | rbtree_postorder_for_each_entry_safe(fname, next, root, rb_hash) | |
ac27a0ec | 391 | while (fname) { |
af5bc92d | 392 | struct fname *old = fname; |
ac27a0ec | 393 | fname = fname->next; |
af5bc92d | 394 | kfree(old); |
ac27a0ec | 395 | } |
d1866bd0 CS |
396 | |
397 | *root = RB_ROOT; | |
ac27a0ec DK |
398 | } |
399 | ||
400 | ||
d1f5273e FY |
401 | static struct dir_private_info *ext4_htree_create_dir_info(struct file *filp, |
402 | loff_t pos) | |
ac27a0ec DK |
403 | { |
404 | struct dir_private_info *p; | |
405 | ||
69baee06 | 406 | p = kzalloc(sizeof(struct dir_private_info), GFP_KERNEL); |
ac27a0ec DK |
407 | if (!p) |
408 | return NULL; | |
d1f5273e FY |
409 | p->curr_hash = pos2maj_hash(filp, pos); |
410 | p->curr_minor_hash = pos2min_hash(filp, pos); | |
ac27a0ec DK |
411 | return p; |
412 | } | |
413 | ||
617ba13b | 414 | void ext4_htree_free_dir_info(struct dir_private_info *p) |
ac27a0ec DK |
415 | { |
416 | free_rb_tree_fname(&p->root); | |
417 | kfree(p); | |
418 | } | |
419 | ||
420 | /* | |
421 | * Given a directory entry, enter it into the fname rb tree. | |
2f61830a TT |
422 | * |
423 | * When filename encryption is enabled, the dirent will hold the | |
424 | * encrypted filename, while the htree will hold decrypted filename. | |
425 | * The decrypted filename is passed in via ent_name. parameter. | |
ac27a0ec | 426 | */ |
617ba13b | 427 | int ext4_htree_store_dirent(struct file *dir_file, __u32 hash, |
ac27a0ec | 428 | __u32 minor_hash, |
2f61830a TT |
429 | struct ext4_dir_entry_2 *dirent, |
430 | struct ext4_str *ent_name) | |
ac27a0ec DK |
431 | { |
432 | struct rb_node **p, *parent = NULL; | |
af5bc92d | 433 | struct fname *fname, *new_fn; |
ac27a0ec DK |
434 | struct dir_private_info *info; |
435 | int len; | |
436 | ||
a271fe85 | 437 | info = dir_file->private_data; |
ac27a0ec DK |
438 | p = &info->root.rb_node; |
439 | ||
440 | /* Create and allocate the fname structure */ | |
2f61830a | 441 | len = sizeof(struct fname) + ent_name->len + 1; |
ac27a0ec DK |
442 | new_fn = kzalloc(len, GFP_KERNEL); |
443 | if (!new_fn) | |
444 | return -ENOMEM; | |
445 | new_fn->hash = hash; | |
446 | new_fn->minor_hash = minor_hash; | |
447 | new_fn->inode = le32_to_cpu(dirent->inode); | |
2f61830a | 448 | new_fn->name_len = ent_name->len; |
ac27a0ec | 449 | new_fn->file_type = dirent->file_type; |
2f61830a TT |
450 | memcpy(new_fn->name, ent_name->name, ent_name->len); |
451 | new_fn->name[ent_name->len] = 0; | |
ac27a0ec DK |
452 | |
453 | while (*p) { | |
454 | parent = *p; | |
455 | fname = rb_entry(parent, struct fname, rb_hash); | |
456 | ||
457 | /* | |
458 | * If the hash and minor hash match up, then we put | |
459 | * them on a linked list. This rarely happens... | |
460 | */ | |
461 | if ((new_fn->hash == fname->hash) && | |
462 | (new_fn->minor_hash == fname->minor_hash)) { | |
463 | new_fn->next = fname->next; | |
464 | fname->next = new_fn; | |
465 | return 0; | |
466 | } | |
467 | ||
468 | if (new_fn->hash < fname->hash) | |
469 | p = &(*p)->rb_left; | |
470 | else if (new_fn->hash > fname->hash) | |
471 | p = &(*p)->rb_right; | |
472 | else if (new_fn->minor_hash < fname->minor_hash) | |
473 | p = &(*p)->rb_left; | |
474 | else /* if (new_fn->minor_hash > fname->minor_hash) */ | |
475 | p = &(*p)->rb_right; | |
476 | } | |
477 | ||
478 | rb_link_node(&new_fn->rb_hash, parent, p); | |
479 | rb_insert_color(&new_fn->rb_hash, &info->root); | |
480 | return 0; | |
481 | } | |
482 | ||
483 | ||
484 | ||
485 | /* | |
617ba13b | 486 | * This is a helper function for ext4_dx_readdir. It calls filldir |
ac27a0ec DK |
487 | * for all entres on the fname linked list. (Normally there is only |
488 | * one entry on the linked list, unless there are 62 bit hash collisions.) | |
489 | */ | |
725bebb2 AV |
490 | static int call_filldir(struct file *file, struct dir_context *ctx, |
491 | struct fname *fname) | |
ac27a0ec | 492 | { |
725bebb2 AV |
493 | struct dir_private_info *info = file->private_data; |
494 | struct inode *inode = file_inode(file); | |
495 | struct super_block *sb = inode->i_sb; | |
ac27a0ec DK |
496 | |
497 | if (!fname) { | |
92b97816 TT |
498 | ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: comm %s: " |
499 | "called with null fname?!?", __func__, __LINE__, | |
500 | inode->i_ino, current->comm); | |
ac27a0ec DK |
501 | return 0; |
502 | } | |
725bebb2 | 503 | ctx->pos = hash2pos(file, fname->hash, fname->minor_hash); |
ac27a0ec | 504 | while (fname) { |
725bebb2 AV |
505 | if (!dir_emit(ctx, fname->name, |
506 | fname->name_len, | |
ac27a0ec | 507 | fname->inode, |
725bebb2 | 508 | get_dtype(sb, fname->file_type))) { |
d0156417 | 509 | info->extra_fname = fname; |
725bebb2 | 510 | return 1; |
ac27a0ec DK |
511 | } |
512 | fname = fname->next; | |
513 | } | |
514 | return 0; | |
515 | } | |
516 | ||
725bebb2 | 517 | static int ext4_dx_readdir(struct file *file, struct dir_context *ctx) |
ac27a0ec | 518 | { |
725bebb2 AV |
519 | struct dir_private_info *info = file->private_data; |
520 | struct inode *inode = file_inode(file); | |
ac27a0ec DK |
521 | struct fname *fname; |
522 | int ret; | |
523 | ||
524 | if (!info) { | |
725bebb2 | 525 | info = ext4_htree_create_dir_info(file, ctx->pos); |
ac27a0ec DK |
526 | if (!info) |
527 | return -ENOMEM; | |
725bebb2 | 528 | file->private_data = info; |
ac27a0ec DK |
529 | } |
530 | ||
725bebb2 | 531 | if (ctx->pos == ext4_get_htree_eof(file)) |
ac27a0ec DK |
532 | return 0; /* EOF */ |
533 | ||
534 | /* Some one has messed with f_pos; reset the world */ | |
725bebb2 | 535 | if (info->last_pos != ctx->pos) { |
ac27a0ec DK |
536 | free_rb_tree_fname(&info->root); |
537 | info->curr_node = NULL; | |
538 | info->extra_fname = NULL; | |
725bebb2 AV |
539 | info->curr_hash = pos2maj_hash(file, ctx->pos); |
540 | info->curr_minor_hash = pos2min_hash(file, ctx->pos); | |
ac27a0ec DK |
541 | } |
542 | ||
543 | /* | |
544 | * If there are any leftover names on the hash collision | |
545 | * chain, return them first. | |
546 | */ | |
d0156417 | 547 | if (info->extra_fname) { |
725bebb2 | 548 | if (call_filldir(file, ctx, info->extra_fname)) |
d0156417 | 549 | goto finished; |
d0156417 | 550 | info->extra_fname = NULL; |
3c37fc86 | 551 | goto next_node; |
d0156417 | 552 | } else if (!info->curr_node) |
ac27a0ec DK |
553 | info->curr_node = rb_first(&info->root); |
554 | ||
555 | while (1) { | |
556 | /* | |
557 | * Fill the rbtree if we have no more entries, | |
558 | * or the inode has changed since we last read in the | |
559 | * cached entries. | |
560 | */ | |
561 | if ((!info->curr_node) || | |
725bebb2 | 562 | (file->f_version != inode->i_version)) { |
ac27a0ec DK |
563 | info->curr_node = NULL; |
564 | free_rb_tree_fname(&info->root); | |
725bebb2 AV |
565 | file->f_version = inode->i_version; |
566 | ret = ext4_htree_fill_tree(file, info->curr_hash, | |
ac27a0ec DK |
567 | info->curr_minor_hash, |
568 | &info->next_hash); | |
569 | if (ret < 0) | |
570 | return ret; | |
571 | if (ret == 0) { | |
725bebb2 | 572 | ctx->pos = ext4_get_htree_eof(file); |
ac27a0ec DK |
573 | break; |
574 | } | |
575 | info->curr_node = rb_first(&info->root); | |
576 | } | |
577 | ||
578 | fname = rb_entry(info->curr_node, struct fname, rb_hash); | |
579 | info->curr_hash = fname->hash; | |
580 | info->curr_minor_hash = fname->minor_hash; | |
725bebb2 | 581 | if (call_filldir(file, ctx, fname)) |
ac27a0ec | 582 | break; |
3c37fc86 | 583 | next_node: |
ac27a0ec | 584 | info->curr_node = rb_next(info->curr_node); |
3c37fc86 TT |
585 | if (info->curr_node) { |
586 | fname = rb_entry(info->curr_node, struct fname, | |
587 | rb_hash); | |
588 | info->curr_hash = fname->hash; | |
589 | info->curr_minor_hash = fname->minor_hash; | |
590 | } else { | |
ac27a0ec | 591 | if (info->next_hash == ~0) { |
725bebb2 | 592 | ctx->pos = ext4_get_htree_eof(file); |
ac27a0ec DK |
593 | break; |
594 | } | |
595 | info->curr_hash = info->next_hash; | |
596 | info->curr_minor_hash = 0; | |
597 | } | |
598 | } | |
599 | finished: | |
725bebb2 | 600 | info->last_pos = ctx->pos; |
ac27a0ec DK |
601 | return 0; |
602 | } | |
603 | ||
6bc445e0 TT |
604 | static int ext4_dir_open(struct inode * inode, struct file * filp) |
605 | { | |
606 | if (ext4_encrypted_inode(inode)) | |
607 | return ext4_get_encryption_info(inode) ? -EACCES : 0; | |
608 | return 0; | |
609 | } | |
610 | ||
af5bc92d | 611 | static int ext4_release_dir(struct inode *inode, struct file *filp) |
ac27a0ec | 612 | { |
63f57933 | 613 | if (filp->private_data) |
617ba13b | 614 | ext4_htree_free_dir_info(filp->private_data); |
ac27a0ec DK |
615 | |
616 | return 0; | |
617 | } | |
d1f5273e | 618 | |
40b163f1 DW |
619 | int ext4_check_all_de(struct inode *dir, struct buffer_head *bh, void *buf, |
620 | int buf_size) | |
621 | { | |
622 | struct ext4_dir_entry_2 *de; | |
623 | int nlen, rlen; | |
624 | unsigned int offset = 0; | |
625 | char *top; | |
626 | ||
627 | de = (struct ext4_dir_entry_2 *)buf; | |
628 | top = buf + buf_size; | |
629 | while ((char *) de < top) { | |
630 | if (ext4_check_dir_entry(dir, NULL, de, bh, | |
631 | buf, buf_size, offset)) | |
6a797d27 | 632 | return -EFSCORRUPTED; |
40b163f1 DW |
633 | nlen = EXT4_DIR_REC_LEN(de->name_len); |
634 | rlen = ext4_rec_len_from_disk(de->rec_len, buf_size); | |
635 | de = (struct ext4_dir_entry_2 *)((char *)de + rlen); | |
636 | offset += rlen; | |
637 | } | |
638 | if ((char *) de > top) | |
6a797d27 | 639 | return -EFSCORRUPTED; |
40b163f1 DW |
640 | |
641 | return 0; | |
642 | } | |
643 | ||
d1f5273e FY |
644 | const struct file_operations ext4_dir_operations = { |
645 | .llseek = ext4_dir_llseek, | |
646 | .read = generic_read_dir, | |
725bebb2 | 647 | .iterate = ext4_readdir, |
d1f5273e FY |
648 | .unlocked_ioctl = ext4_ioctl, |
649 | #ifdef CONFIG_COMPAT | |
650 | .compat_ioctl = ext4_compat_ioctl, | |
651 | #endif | |
652 | .fsync = ext4_sync_file, | |
6bc445e0 | 653 | .open = ext4_dir_open, |
d1f5273e FY |
654 | .release = ext4_release_dir, |
655 | }; |