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> | |
dab291af | 25 | #include <linux/jbd2.h> |
ac27a0ec | 26 | #include <linux/buffer_head.h> |
ac27a0ec DK |
27 | #include <linux/slab.h> |
28 | #include <linux/rbtree.h> | |
3dcf5451 | 29 | #include "ext4.h" |
ac27a0ec | 30 | |
617ba13b | 31 | static unsigned char ext4_filetype_table[] = { |
ac27a0ec DK |
32 | DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK |
33 | }; | |
34 | ||
af5bc92d TT |
35 | static int ext4_dx_readdir(struct file *filp, |
36 | void *dirent, filldir_t filldir); | |
ac27a0ec DK |
37 | |
38 | static unsigned char get_dtype(struct super_block *sb, int filetype) | |
39 | { | |
617ba13b MC |
40 | if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE) || |
41 | (filetype >= EXT4_FT_MAX)) | |
ac27a0ec DK |
42 | return DT_UNKNOWN; |
43 | ||
617ba13b | 44 | return (ext4_filetype_table[filetype]); |
ac27a0ec DK |
45 | } |
46 | ||
d1f5273e FY |
47 | /** |
48 | * Check if the given dir-inode refers to an htree-indexed directory | |
49 | * (or a directory which chould potentially get coverted to use htree | |
50 | * indexing). | |
51 | * | |
52 | * Return 1 if it is a dx dir, 0 if not | |
53 | */ | |
54 | static int is_dx_dir(struct inode *inode) | |
55 | { | |
56 | struct super_block *sb = inode->i_sb; | |
57 | ||
58 | if (EXT4_HAS_COMPAT_FEATURE(inode->i_sb, | |
59 | EXT4_FEATURE_COMPAT_DIR_INDEX) && | |
60 | ((ext4_test_inode_flag(inode, EXT4_INODE_INDEX)) || | |
61 | ((inode->i_size >> sb->s_blocksize_bits) == 1))) | |
62 | return 1; | |
63 | ||
64 | return 0; | |
65 | } | |
66 | ||
cad3f007 TT |
67 | /* |
68 | * Return 0 if the directory entry is OK, and 1 if there is a problem | |
69 | * | |
70 | * Note: this is the opposite of what ext2 and ext3 historically returned... | |
71 | */ | |
60fd4da3 | 72 | int __ext4_check_dir_entry(const char *function, unsigned int line, |
f7c21177 | 73 | struct inode *dir, struct file *filp, |
60fd4da3 TT |
74 | struct ext4_dir_entry_2 *de, |
75 | struct buffer_head *bh, | |
76 | unsigned int offset) | |
ac27a0ec | 77 | { |
af5bc92d | 78 | const char *error_msg = NULL; |
3d0518f4 WY |
79 | const int rlen = ext4_rec_len_from_disk(de->rec_len, |
80 | dir->i_sb->s_blocksize); | |
ac27a0ec | 81 | |
cad3f007 | 82 | if (unlikely(rlen < EXT4_DIR_REC_LEN(1))) |
ac27a0ec | 83 | error_msg = "rec_len is smaller than minimal"; |
cad3f007 | 84 | else if (unlikely(rlen % 4 != 0)) |
ac27a0ec | 85 | error_msg = "rec_len % 4 != 0"; |
cad3f007 | 86 | else if (unlikely(rlen < EXT4_DIR_REC_LEN(de->name_len))) |
ac27a0ec | 87 | error_msg = "rec_len is too small for name_len"; |
cad3f007 TT |
88 | else if (unlikely(((char *) de - bh->b_data) + rlen > |
89 | dir->i_sb->s_blocksize)) | |
ac27a0ec | 90 | error_msg = "directory entry across blocks"; |
cad3f007 TT |
91 | else if (unlikely(le32_to_cpu(de->inode) > |
92 | le32_to_cpu(EXT4_SB(dir->i_sb)->s_es->s_inodes_count))) | |
ac27a0ec | 93 | error_msg = "inode out of bounds"; |
cad3f007 TT |
94 | else |
95 | return 0; | |
96 | ||
f7c21177 | 97 | if (filp) |
4fda4003 | 98 | ext4_error_file(filp, function, line, bh->b_blocknr, |
f7c21177 TT |
99 | "bad entry in directory: %s - offset=%u(%u), " |
100 | "inode=%u, rec_len=%d, name_len=%d", | |
4fda4003 | 101 | error_msg, (unsigned) (offset % bh->b_size), |
f7c21177 TT |
102 | offset, le32_to_cpu(de->inode), |
103 | rlen, de->name_len); | |
104 | else | |
4fda4003 | 105 | ext4_error_inode(dir, function, line, bh->b_blocknr, |
f7c21177 TT |
106 | "bad entry in directory: %s - offset=%u(%u), " |
107 | "inode=%u, rec_len=%d, name_len=%d", | |
4fda4003 | 108 | error_msg, (unsigned) (offset % bh->b_size), |
f7c21177 TT |
109 | offset, le32_to_cpu(de->inode), |
110 | rlen, de->name_len); | |
111 | ||
cad3f007 | 112 | return 1; |
ac27a0ec DK |
113 | } |
114 | ||
af5bc92d TT |
115 | static int ext4_readdir(struct file *filp, |
116 | void *dirent, filldir_t filldir) | |
ac27a0ec DK |
117 | { |
118 | int error = 0; | |
498e5f24 | 119 | unsigned int offset; |
ac27a0ec | 120 | int i, stored; |
617ba13b | 121 | struct ext4_dir_entry_2 *de; |
ac27a0ec | 122 | int err; |
9d549890 | 123 | struct inode *inode = filp->f_path.dentry->d_inode; |
d1f5273e | 124 | struct super_block *sb = inode->i_sb; |
ac27a0ec | 125 | int ret = 0; |
9d9f1775 | 126 | int dir_has_error = 0; |
ac27a0ec | 127 | |
d1f5273e | 128 | if (is_dx_dir(inode)) { |
617ba13b | 129 | err = ext4_dx_readdir(filp, dirent, filldir); |
ac27a0ec DK |
130 | if (err != ERR_BAD_DX_DIR) { |
131 | ret = err; | |
132 | goto out; | |
133 | } | |
134 | /* | |
135 | * We don't set the inode dirty flag since it's not | |
136 | * critical that it get flushed back to the disk. | |
137 | */ | |
07a03824 TT |
138 | ext4_clear_inode_flag(filp->f_path.dentry->d_inode, |
139 | EXT4_INODE_INDEX); | |
ac27a0ec | 140 | } |
ac27a0ec DK |
141 | stored = 0; |
142 | offset = filp->f_pos & (sb->s_blocksize - 1); | |
143 | ||
144 | while (!error && !stored && filp->f_pos < inode->i_size) { | |
2ed88685 | 145 | struct ext4_map_blocks map; |
ac27a0ec DK |
146 | struct buffer_head *bh = NULL; |
147 | ||
2ed88685 TT |
148 | map.m_lblk = filp->f_pos >> EXT4_BLOCK_SIZE_BITS(sb); |
149 | map.m_len = 1; | |
150 | err = ext4_map_blocks(NULL, inode, &map, 0); | |
ac27a0ec | 151 | if (err > 0) { |
2ed88685 | 152 | pgoff_t index = map.m_pblk >> |
dc7868fc FW |
153 | (PAGE_CACHE_SHIFT - inode->i_blkbits); |
154 | if (!ra_has_index(&filp->f_ra, index)) | |
cf914a7d | 155 | page_cache_sync_readahead( |
dc7868fc FW |
156 | sb->s_bdev->bd_inode->i_mapping, |
157 | &filp->f_ra, filp, | |
cf914a7d | 158 | index, 1); |
f4e6b498 | 159 | filp->f_ra.prev_pos = (loff_t)index << PAGE_CACHE_SHIFT; |
2ed88685 | 160 | bh = ext4_bread(NULL, inode, map.m_lblk, 0, &err); |
ac27a0ec DK |
161 | } |
162 | ||
163 | /* | |
164 | * We ignore I/O errors on directories so users have a chance | |
165 | * of recovering data when there's a bad sector | |
166 | */ | |
167 | if (!bh) { | |
9d9f1775 | 168 | if (!dir_has_error) { |
f7c21177 TT |
169 | EXT4_ERROR_FILE(filp, 0, |
170 | "directory contains a " | |
171 | "hole at offset %llu", | |
9d9f1775 ES |
172 | (unsigned long long) filp->f_pos); |
173 | dir_has_error = 1; | |
174 | } | |
e6c40211 ES |
175 | /* corrupt size? Maybe no more blocks to read */ |
176 | if (filp->f_pos > inode->i_blocks << 9) | |
177 | break; | |
ac27a0ec DK |
178 | filp->f_pos += sb->s_blocksize - offset; |
179 | continue; | |
180 | } | |
181 | ||
182 | revalidate: | |
183 | /* If the dir block has changed since the last call to | |
184 | * readdir(2), then we might be pointing to an invalid | |
185 | * dirent right now. Scan from the start of the block | |
186 | * to make sure. */ | |
187 | if (filp->f_version != inode->i_version) { | |
188 | for (i = 0; i < sb->s_blocksize && i < offset; ) { | |
617ba13b | 189 | de = (struct ext4_dir_entry_2 *) |
ac27a0ec DK |
190 | (bh->b_data + i); |
191 | /* It's too expensive to do a full | |
192 | * dirent test each time round this | |
193 | * loop, but we do have to test at | |
194 | * least that it is non-zero. A | |
195 | * failure will be detected in the | |
196 | * dirent test below. */ | |
3d0518f4 WY |
197 | if (ext4_rec_len_from_disk(de->rec_len, |
198 | sb->s_blocksize) < EXT4_DIR_REC_LEN(1)) | |
ac27a0ec | 199 | break; |
3d0518f4 WY |
200 | i += ext4_rec_len_from_disk(de->rec_len, |
201 | sb->s_blocksize); | |
ac27a0ec DK |
202 | } |
203 | offset = i; | |
204 | filp->f_pos = (filp->f_pos & ~(sb->s_blocksize - 1)) | |
205 | | offset; | |
206 | filp->f_version = inode->i_version; | |
207 | } | |
208 | ||
209 | while (!error && filp->f_pos < inode->i_size | |
210 | && offset < sb->s_blocksize) { | |
617ba13b | 211 | de = (struct ext4_dir_entry_2 *) (bh->b_data + offset); |
f7c21177 | 212 | if (ext4_check_dir_entry(inode, filp, de, |
cad3f007 | 213 | bh, offset)) { |
63f57933 AM |
214 | /* |
215 | * On error, skip the f_pos to the next block | |
216 | */ | |
ac27a0ec DK |
217 | filp->f_pos = (filp->f_pos | |
218 | (sb->s_blocksize - 1)) + 1; | |
af5bc92d | 219 | brelse(bh); |
ac27a0ec DK |
220 | ret = stored; |
221 | goto out; | |
222 | } | |
3d0518f4 WY |
223 | offset += ext4_rec_len_from_disk(de->rec_len, |
224 | sb->s_blocksize); | |
ac27a0ec DK |
225 | if (le32_to_cpu(de->inode)) { |
226 | /* We might block in the next section | |
227 | * if the data destination is | |
228 | * currently swapped out. So, use a | |
229 | * version stamp to detect whether or | |
230 | * not the directory has been modified | |
231 | * during the copy operation. | |
232 | */ | |
2b47c361 | 233 | u64 version = filp->f_version; |
ac27a0ec DK |
234 | |
235 | error = filldir(dirent, de->name, | |
236 | de->name_len, | |
237 | filp->f_pos, | |
238 | le32_to_cpu(de->inode), | |
239 | get_dtype(sb, de->file_type)); | |
240 | if (error) | |
241 | break; | |
242 | if (version != filp->f_version) | |
243 | goto revalidate; | |
af5bc92d | 244 | stored++; |
ac27a0ec | 245 | } |
3d0518f4 WY |
246 | filp->f_pos += ext4_rec_len_from_disk(de->rec_len, |
247 | sb->s_blocksize); | |
ac27a0ec DK |
248 | } |
249 | offset = 0; | |
af5bc92d | 250 | brelse(bh); |
ac27a0ec DK |
251 | } |
252 | out: | |
253 | return ret; | |
254 | } | |
255 | ||
d1f5273e FY |
256 | static inline int is_32bit_api(void) |
257 | { | |
258 | #ifdef CONFIG_COMPAT | |
259 | return is_compat_task(); | |
260 | #else | |
261 | return (BITS_PER_LONG == 32); | |
262 | #endif | |
263 | } | |
264 | ||
ac27a0ec DK |
265 | /* |
266 | * These functions convert from the major/minor hash to an f_pos | |
d1f5273e FY |
267 | * value for dx directories |
268 | * | |
269 | * Upper layer (for example NFS) should specify FMODE_32BITHASH or | |
270 | * FMODE_64BITHASH explicitly. On the other hand, we allow ext4 to be mounted | |
271 | * directly on both 32-bit and 64-bit nodes, under such case, neither | |
272 | * FMODE_32BITHASH nor FMODE_64BITHASH is specified. | |
273 | */ | |
274 | static inline loff_t hash2pos(struct file *filp, __u32 major, __u32 minor) | |
275 | { | |
276 | if ((filp->f_mode & FMODE_32BITHASH) || | |
277 | (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api())) | |
278 | return major >> 1; | |
279 | else | |
280 | return ((__u64)(major >> 1) << 32) | (__u64)minor; | |
281 | } | |
282 | ||
283 | static inline __u32 pos2maj_hash(struct file *filp, loff_t pos) | |
284 | { | |
285 | if ((filp->f_mode & FMODE_32BITHASH) || | |
286 | (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api())) | |
287 | return (pos << 1) & 0xffffffff; | |
288 | else | |
289 | return ((pos >> 32) << 1) & 0xffffffff; | |
290 | } | |
291 | ||
292 | static inline __u32 pos2min_hash(struct file *filp, loff_t pos) | |
293 | { | |
294 | if ((filp->f_mode & FMODE_32BITHASH) || | |
295 | (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api())) | |
296 | return 0; | |
297 | else | |
298 | return pos & 0xffffffff; | |
299 | } | |
300 | ||
301 | /* | |
302 | * Return 32- or 64-bit end-of-file for dx directories | |
303 | */ | |
304 | static inline loff_t ext4_get_htree_eof(struct file *filp) | |
305 | { | |
306 | if ((filp->f_mode & FMODE_32BITHASH) || | |
307 | (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api())) | |
308 | return EXT4_HTREE_EOF_32BIT; | |
309 | else | |
310 | return EXT4_HTREE_EOF_64BIT; | |
311 | } | |
312 | ||
313 | ||
314 | /* | |
315 | * ext4_dir_llseek() based on generic_file_llseek() to handle both | |
316 | * non-htree and htree directories, where the "offset" is in terms | |
317 | * of the filename hash value instead of the byte offset. | |
ac27a0ec | 318 | * |
d1f5273e FY |
319 | * NOTE: offsets obtained *before* ext4_set_inode_flag(dir, EXT4_INODE_INDEX) |
320 | * will be invalid once the directory was converted into a dx directory | |
ac27a0ec | 321 | */ |
d1f5273e FY |
322 | loff_t ext4_dir_llseek(struct file *file, loff_t offset, int origin) |
323 | { | |
324 | struct inode *inode = file->f_mapping->host; | |
325 | loff_t ret = -EINVAL; | |
326 | int dx_dir = is_dx_dir(inode); | |
327 | ||
328 | mutex_lock(&inode->i_mutex); | |
329 | ||
330 | /* NOTE: relative offsets with dx directories might not work | |
331 | * as expected, as it is difficult to figure out the | |
332 | * correct offset between dx hashes */ | |
333 | ||
334 | switch (origin) { | |
335 | case SEEK_END: | |
336 | if (unlikely(offset > 0)) | |
337 | goto out_err; /* not supported for directories */ | |
338 | ||
339 | /* so only negative offsets are left, does that have a | |
340 | * meaning for directories at all? */ | |
341 | if (dx_dir) | |
342 | offset += ext4_get_htree_eof(file); | |
343 | else | |
344 | offset += inode->i_size; | |
345 | break; | |
346 | case SEEK_CUR: | |
347 | /* | |
348 | * Here we special-case the lseek(fd, 0, SEEK_CUR) | |
349 | * position-querying operation. Avoid rewriting the "same" | |
350 | * f_pos value back to the file because a concurrent read(), | |
351 | * write() or lseek() might have altered it | |
352 | */ | |
353 | if (offset == 0) { | |
354 | offset = file->f_pos; | |
355 | goto out_ok; | |
356 | } | |
357 | ||
358 | offset += file->f_pos; | |
359 | break; | |
360 | } | |
361 | ||
362 | if (unlikely(offset < 0)) | |
363 | goto out_err; | |
364 | ||
365 | if (!dx_dir) { | |
366 | if (offset > inode->i_sb->s_maxbytes) | |
367 | goto out_err; | |
368 | } else if (offset > ext4_get_htree_eof(file)) | |
369 | goto out_err; | |
370 | ||
371 | /* Special lock needed here? */ | |
372 | if (offset != file->f_pos) { | |
373 | file->f_pos = offset; | |
374 | file->f_version = 0; | |
375 | } | |
376 | ||
377 | out_ok: | |
378 | ret = offset; | |
379 | out_err: | |
380 | mutex_unlock(&inode->i_mutex); | |
381 | ||
382 | return ret; | |
383 | } | |
ac27a0ec DK |
384 | |
385 | /* | |
386 | * This structure holds the nodes of the red-black tree used to store | |
387 | * the directory entry in hash order. | |
388 | */ | |
389 | struct fname { | |
390 | __u32 hash; | |
391 | __u32 minor_hash; | |
392 | struct rb_node rb_hash; | |
393 | struct fname *next; | |
394 | __u32 inode; | |
395 | __u8 name_len; | |
396 | __u8 file_type; | |
397 | char name[0]; | |
398 | }; | |
399 | ||
400 | /* | |
401 | * This functoin implements a non-recursive way of freeing all of the | |
402 | * nodes in the red-black tree. | |
403 | */ | |
404 | static void free_rb_tree_fname(struct rb_root *root) | |
405 | { | |
406 | struct rb_node *n = root->rb_node; | |
407 | struct rb_node *parent; | |
408 | struct fname *fname; | |
409 | ||
410 | while (n) { | |
411 | /* Do the node's children first */ | |
69baee06 | 412 | if (n->rb_left) { |
ac27a0ec DK |
413 | n = n->rb_left; |
414 | continue; | |
415 | } | |
416 | if (n->rb_right) { | |
417 | n = n->rb_right; | |
418 | continue; | |
419 | } | |
420 | /* | |
421 | * The node has no children; free it, and then zero | |
422 | * out parent's link to it. Finally go to the | |
423 | * beginning of the loop and try to free the parent | |
424 | * node. | |
425 | */ | |
426 | parent = rb_parent(n); | |
427 | fname = rb_entry(n, struct fname, rb_hash); | |
428 | while (fname) { | |
af5bc92d | 429 | struct fname *old = fname; |
ac27a0ec | 430 | fname = fname->next; |
af5bc92d | 431 | kfree(old); |
ac27a0ec DK |
432 | } |
433 | if (!parent) | |
64e290ec | 434 | *root = RB_ROOT; |
ac27a0ec DK |
435 | else if (parent->rb_left == n) |
436 | parent->rb_left = NULL; | |
437 | else if (parent->rb_right == n) | |
438 | parent->rb_right = NULL; | |
439 | n = parent; | |
440 | } | |
ac27a0ec DK |
441 | } |
442 | ||
443 | ||
d1f5273e FY |
444 | static struct dir_private_info *ext4_htree_create_dir_info(struct file *filp, |
445 | loff_t pos) | |
ac27a0ec DK |
446 | { |
447 | struct dir_private_info *p; | |
448 | ||
69baee06 | 449 | p = kzalloc(sizeof(struct dir_private_info), GFP_KERNEL); |
ac27a0ec DK |
450 | if (!p) |
451 | return NULL; | |
d1f5273e FY |
452 | p->curr_hash = pos2maj_hash(filp, pos); |
453 | p->curr_minor_hash = pos2min_hash(filp, pos); | |
ac27a0ec DK |
454 | return p; |
455 | } | |
456 | ||
617ba13b | 457 | void ext4_htree_free_dir_info(struct dir_private_info *p) |
ac27a0ec DK |
458 | { |
459 | free_rb_tree_fname(&p->root); | |
460 | kfree(p); | |
461 | } | |
462 | ||
463 | /* | |
464 | * Given a directory entry, enter it into the fname rb tree. | |
465 | */ | |
617ba13b | 466 | int ext4_htree_store_dirent(struct file *dir_file, __u32 hash, |
ac27a0ec | 467 | __u32 minor_hash, |
617ba13b | 468 | struct ext4_dir_entry_2 *dirent) |
ac27a0ec DK |
469 | { |
470 | struct rb_node **p, *parent = NULL; | |
af5bc92d | 471 | struct fname *fname, *new_fn; |
ac27a0ec DK |
472 | struct dir_private_info *info; |
473 | int len; | |
474 | ||
a271fe85 | 475 | info = dir_file->private_data; |
ac27a0ec DK |
476 | p = &info->root.rb_node; |
477 | ||
478 | /* Create and allocate the fname structure */ | |
479 | len = sizeof(struct fname) + dirent->name_len + 1; | |
480 | new_fn = kzalloc(len, GFP_KERNEL); | |
481 | if (!new_fn) | |
482 | return -ENOMEM; | |
483 | new_fn->hash = hash; | |
484 | new_fn->minor_hash = minor_hash; | |
485 | new_fn->inode = le32_to_cpu(dirent->inode); | |
486 | new_fn->name_len = dirent->name_len; | |
487 | new_fn->file_type = dirent->file_type; | |
488 | memcpy(new_fn->name, dirent->name, dirent->name_len); | |
489 | new_fn->name[dirent->name_len] = 0; | |
490 | ||
491 | while (*p) { | |
492 | parent = *p; | |
493 | fname = rb_entry(parent, struct fname, rb_hash); | |
494 | ||
495 | /* | |
496 | * If the hash and minor hash match up, then we put | |
497 | * them on a linked list. This rarely happens... | |
498 | */ | |
499 | if ((new_fn->hash == fname->hash) && | |
500 | (new_fn->minor_hash == fname->minor_hash)) { | |
501 | new_fn->next = fname->next; | |
502 | fname->next = new_fn; | |
503 | return 0; | |
504 | } | |
505 | ||
506 | if (new_fn->hash < fname->hash) | |
507 | p = &(*p)->rb_left; | |
508 | else if (new_fn->hash > fname->hash) | |
509 | p = &(*p)->rb_right; | |
510 | else if (new_fn->minor_hash < fname->minor_hash) | |
511 | p = &(*p)->rb_left; | |
512 | else /* if (new_fn->minor_hash > fname->minor_hash) */ | |
513 | p = &(*p)->rb_right; | |
514 | } | |
515 | ||
516 | rb_link_node(&new_fn->rb_hash, parent, p); | |
517 | rb_insert_color(&new_fn->rb_hash, &info->root); | |
518 | return 0; | |
519 | } | |
520 | ||
521 | ||
522 | ||
523 | /* | |
617ba13b | 524 | * This is a helper function for ext4_dx_readdir. It calls filldir |
ac27a0ec DK |
525 | * for all entres on the fname linked list. (Normally there is only |
526 | * one entry on the linked list, unless there are 62 bit hash collisions.) | |
527 | */ | |
af5bc92d | 528 | static int call_filldir(struct file *filp, void *dirent, |
ac27a0ec DK |
529 | filldir_t filldir, struct fname *fname) |
530 | { | |
531 | struct dir_private_info *info = filp->private_data; | |
532 | loff_t curr_pos; | |
9d549890 | 533 | struct inode *inode = filp->f_path.dentry->d_inode; |
af5bc92d | 534 | struct super_block *sb; |
ac27a0ec DK |
535 | int error; |
536 | ||
537 | sb = inode->i_sb; | |
538 | ||
539 | if (!fname) { | |
92b97816 TT |
540 | ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: comm %s: " |
541 | "called with null fname?!?", __func__, __LINE__, | |
542 | inode->i_ino, current->comm); | |
ac27a0ec DK |
543 | return 0; |
544 | } | |
d1f5273e | 545 | curr_pos = hash2pos(filp, fname->hash, fname->minor_hash); |
ac27a0ec DK |
546 | while (fname) { |
547 | error = filldir(dirent, fname->name, | |
548 | fname->name_len, curr_pos, | |
549 | fname->inode, | |
550 | get_dtype(sb, fname->file_type)); | |
551 | if (error) { | |
552 | filp->f_pos = curr_pos; | |
d0156417 | 553 | info->extra_fname = fname; |
ac27a0ec DK |
554 | return error; |
555 | } | |
556 | fname = fname->next; | |
557 | } | |
558 | return 0; | |
559 | } | |
560 | ||
af5bc92d TT |
561 | static int ext4_dx_readdir(struct file *filp, |
562 | void *dirent, filldir_t filldir) | |
ac27a0ec DK |
563 | { |
564 | struct dir_private_info *info = filp->private_data; | |
9d549890 | 565 | struct inode *inode = filp->f_path.dentry->d_inode; |
ac27a0ec DK |
566 | struct fname *fname; |
567 | int ret; | |
568 | ||
569 | if (!info) { | |
d1f5273e | 570 | info = ext4_htree_create_dir_info(filp, filp->f_pos); |
ac27a0ec DK |
571 | if (!info) |
572 | return -ENOMEM; | |
573 | filp->private_data = info; | |
574 | } | |
575 | ||
d1f5273e | 576 | if (filp->f_pos == ext4_get_htree_eof(filp)) |
ac27a0ec DK |
577 | return 0; /* EOF */ |
578 | ||
579 | /* Some one has messed with f_pos; reset the world */ | |
580 | if (info->last_pos != filp->f_pos) { | |
581 | free_rb_tree_fname(&info->root); | |
582 | info->curr_node = NULL; | |
583 | info->extra_fname = NULL; | |
d1f5273e FY |
584 | info->curr_hash = pos2maj_hash(filp, filp->f_pos); |
585 | info->curr_minor_hash = pos2min_hash(filp, filp->f_pos); | |
ac27a0ec DK |
586 | } |
587 | ||
588 | /* | |
589 | * If there are any leftover names on the hash collision | |
590 | * chain, return them first. | |
591 | */ | |
d0156417 TT |
592 | if (info->extra_fname) { |
593 | if (call_filldir(filp, dirent, filldir, info->extra_fname)) | |
594 | goto finished; | |
d0156417 | 595 | info->extra_fname = NULL; |
3c37fc86 | 596 | goto next_node; |
d0156417 | 597 | } else if (!info->curr_node) |
ac27a0ec DK |
598 | info->curr_node = rb_first(&info->root); |
599 | ||
600 | while (1) { | |
601 | /* | |
602 | * Fill the rbtree if we have no more entries, | |
603 | * or the inode has changed since we last read in the | |
604 | * cached entries. | |
605 | */ | |
606 | if ((!info->curr_node) || | |
607 | (filp->f_version != inode->i_version)) { | |
608 | info->curr_node = NULL; | |
609 | free_rb_tree_fname(&info->root); | |
610 | filp->f_version = inode->i_version; | |
617ba13b | 611 | ret = ext4_htree_fill_tree(filp, info->curr_hash, |
ac27a0ec DK |
612 | info->curr_minor_hash, |
613 | &info->next_hash); | |
614 | if (ret < 0) | |
615 | return ret; | |
616 | if (ret == 0) { | |
d1f5273e | 617 | filp->f_pos = ext4_get_htree_eof(filp); |
ac27a0ec DK |
618 | break; |
619 | } | |
620 | info->curr_node = rb_first(&info->root); | |
621 | } | |
622 | ||
623 | fname = rb_entry(info->curr_node, struct fname, rb_hash); | |
624 | info->curr_hash = fname->hash; | |
625 | info->curr_minor_hash = fname->minor_hash; | |
626 | if (call_filldir(filp, dirent, filldir, fname)) | |
627 | break; | |
3c37fc86 | 628 | next_node: |
ac27a0ec | 629 | info->curr_node = rb_next(info->curr_node); |
3c37fc86 TT |
630 | if (info->curr_node) { |
631 | fname = rb_entry(info->curr_node, struct fname, | |
632 | rb_hash); | |
633 | info->curr_hash = fname->hash; | |
634 | info->curr_minor_hash = fname->minor_hash; | |
635 | } else { | |
ac27a0ec | 636 | if (info->next_hash == ~0) { |
d1f5273e | 637 | filp->f_pos = ext4_get_htree_eof(filp); |
ac27a0ec DK |
638 | break; |
639 | } | |
640 | info->curr_hash = info->next_hash; | |
641 | info->curr_minor_hash = 0; | |
642 | } | |
643 | } | |
644 | finished: | |
645 | info->last_pos = filp->f_pos; | |
646 | return 0; | |
647 | } | |
648 | ||
af5bc92d | 649 | static int ext4_release_dir(struct inode *inode, struct file *filp) |
ac27a0ec | 650 | { |
63f57933 | 651 | if (filp->private_data) |
617ba13b | 652 | ext4_htree_free_dir_info(filp->private_data); |
ac27a0ec DK |
653 | |
654 | return 0; | |
655 | } | |
d1f5273e FY |
656 | |
657 | const struct file_operations ext4_dir_operations = { | |
658 | .llseek = ext4_dir_llseek, | |
659 | .read = generic_read_dir, | |
660 | .readdir = ext4_readdir, | |
661 | .unlocked_ioctl = ext4_ioctl, | |
662 | #ifdef CONFIG_COMPAT | |
663 | .compat_ioctl = ext4_compat_ioctl, | |
664 | #endif | |
665 | .fsync = ext4_sync_file, | |
666 | .release = ext4_release_dir, | |
667 | }; |