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" |
65d165d9 | 30 | #include "xattr.h" |
ac27a0ec | 31 | |
725bebb2 | 32 | static int ext4_dx_readdir(struct file *, struct dir_context *); |
ac27a0ec | 33 | |
d1f5273e FY |
34 | /** |
35 | * Check if the given dir-inode refers to an htree-indexed directory | |
70261f56 | 36 | * (or a directory which could potentially get converted to use htree |
d1f5273e FY |
37 | * indexing). |
38 | * | |
39 | * Return 1 if it is a dx dir, 0 if not | |
40 | */ | |
41 | static int is_dx_dir(struct inode *inode) | |
42 | { | |
43 | struct super_block *sb = inode->i_sb; | |
44 | ||
45 | if (EXT4_HAS_COMPAT_FEATURE(inode->i_sb, | |
46 | EXT4_FEATURE_COMPAT_DIR_INDEX) && | |
47 | ((ext4_test_inode_flag(inode, EXT4_INODE_INDEX)) || | |
8af0f082 TM |
48 | ((inode->i_size >> sb->s_blocksize_bits) == 1) || |
49 | ext4_has_inline_data(inode))) | |
d1f5273e FY |
50 | return 1; |
51 | ||
52 | return 0; | |
53 | } | |
54 | ||
cad3f007 TT |
55 | /* |
56 | * Return 0 if the directory entry is OK, and 1 if there is a problem | |
57 | * | |
58 | * Note: this is the opposite of what ext2 and ext3 historically returned... | |
65d165d9 TM |
59 | * |
60 | * bh passed here can be an inode block or a dir data block, depending | |
61 | * on the inode inline data flag. | |
cad3f007 | 62 | */ |
60fd4da3 | 63 | int __ext4_check_dir_entry(const char *function, unsigned int line, |
f7c21177 | 64 | struct inode *dir, struct file *filp, |
60fd4da3 | 65 | struct ext4_dir_entry_2 *de, |
226ba972 | 66 | struct buffer_head *bh, char *buf, int size, |
60fd4da3 | 67 | unsigned int offset) |
ac27a0ec | 68 | { |
af5bc92d | 69 | const char *error_msg = NULL; |
3d0518f4 WY |
70 | const int rlen = ext4_rec_len_from_disk(de->rec_len, |
71 | dir->i_sb->s_blocksize); | |
ac27a0ec | 72 | |
cad3f007 | 73 | if (unlikely(rlen < EXT4_DIR_REC_LEN(1))) |
ac27a0ec | 74 | error_msg = "rec_len is smaller than minimal"; |
cad3f007 | 75 | else if (unlikely(rlen % 4 != 0)) |
ac27a0ec | 76 | error_msg = "rec_len % 4 != 0"; |
cad3f007 | 77 | else if (unlikely(rlen < EXT4_DIR_REC_LEN(de->name_len))) |
ac27a0ec | 78 | error_msg = "rec_len is too small for name_len"; |
226ba972 TM |
79 | else if (unlikely(((char *) de - buf) + rlen > size)) |
80 | error_msg = "directory entry across range"; | |
cad3f007 TT |
81 | else if (unlikely(le32_to_cpu(de->inode) > |
82 | le32_to_cpu(EXT4_SB(dir->i_sb)->s_es->s_inodes_count))) | |
ac27a0ec | 83 | error_msg = "inode out of bounds"; |
cad3f007 TT |
84 | else |
85 | return 0; | |
86 | ||
f7c21177 | 87 | if (filp) |
4fda4003 | 88 | ext4_error_file(filp, function, line, bh->b_blocknr, |
f7c21177 TT |
89 | "bad entry in directory: %s - offset=%u(%u), " |
90 | "inode=%u, rec_len=%d, name_len=%d", | |
226ba972 | 91 | error_msg, (unsigned) (offset % size), |
f7c21177 TT |
92 | offset, le32_to_cpu(de->inode), |
93 | rlen, de->name_len); | |
94 | else | |
4fda4003 | 95 | ext4_error_inode(dir, function, line, bh->b_blocknr, |
f7c21177 TT |
96 | "bad entry in directory: %s - offset=%u(%u), " |
97 | "inode=%u, rec_len=%d, name_len=%d", | |
226ba972 | 98 | error_msg, (unsigned) (offset % size), |
f7c21177 TT |
99 | offset, le32_to_cpu(de->inode), |
100 | rlen, de->name_len); | |
101 | ||
cad3f007 | 102 | return 1; |
ac27a0ec DK |
103 | } |
104 | ||
725bebb2 | 105 | static int ext4_readdir(struct file *file, struct dir_context *ctx) |
ac27a0ec | 106 | { |
498e5f24 | 107 | unsigned int offset; |
aa13d5f6 | 108 | int i; |
617ba13b | 109 | struct ext4_dir_entry_2 *de; |
ac27a0ec | 110 | int err; |
725bebb2 | 111 | struct inode *inode = file_inode(file); |
d1f5273e | 112 | struct super_block *sb = inode->i_sb; |
9d9f1775 | 113 | int dir_has_error = 0; |
ac27a0ec | 114 | |
d1f5273e | 115 | if (is_dx_dir(inode)) { |
725bebb2 | 116 | err = ext4_dx_readdir(file, ctx); |
ac27a0ec | 117 | if (err != ERR_BAD_DX_DIR) { |
725bebb2 | 118 | return err; |
ac27a0ec DK |
119 | } |
120 | /* | |
121 | * We don't set the inode dirty flag since it's not | |
122 | * critical that it get flushed back to the disk. | |
123 | */ | |
725bebb2 | 124 | ext4_clear_inode_flag(file_inode(file), |
07a03824 | 125 | EXT4_INODE_INDEX); |
ac27a0ec | 126 | } |
8af0f082 TM |
127 | |
128 | if (ext4_has_inline_data(inode)) { | |
129 | int has_inline_data = 1; | |
725bebb2 | 130 | int ret = ext4_read_inline_dir(file, ctx, |
8af0f082 TM |
131 | &has_inline_data); |
132 | if (has_inline_data) | |
133 | return ret; | |
134 | } | |
135 | ||
725bebb2 | 136 | offset = ctx->pos & (sb->s_blocksize - 1); |
ac27a0ec | 137 | |
725bebb2 | 138 | while (ctx->pos < inode->i_size) { |
2ed88685 | 139 | struct ext4_map_blocks map; |
ac27a0ec DK |
140 | struct buffer_head *bh = NULL; |
141 | ||
725bebb2 | 142 | map.m_lblk = ctx->pos >> EXT4_BLOCK_SIZE_BITS(sb); |
2ed88685 TT |
143 | map.m_len = 1; |
144 | err = ext4_map_blocks(NULL, inode, &map, 0); | |
ac27a0ec | 145 | if (err > 0) { |
2ed88685 | 146 | pgoff_t index = map.m_pblk >> |
dc7868fc | 147 | (PAGE_CACHE_SHIFT - inode->i_blkbits); |
725bebb2 | 148 | if (!ra_has_index(&file->f_ra, index)) |
cf914a7d | 149 | page_cache_sync_readahead( |
dc7868fc | 150 | sb->s_bdev->bd_inode->i_mapping, |
725bebb2 | 151 | &file->f_ra, file, |
cf914a7d | 152 | index, 1); |
725bebb2 | 153 | file->f_ra.prev_pos = (loff_t)index << PAGE_CACHE_SHIFT; |
2ed88685 | 154 | bh = ext4_bread(NULL, inode, map.m_lblk, 0, &err); |
ac27a0ec DK |
155 | } |
156 | ||
157 | /* | |
158 | * We ignore I/O errors on directories so users have a chance | |
159 | * of recovering data when there's a bad sector | |
160 | */ | |
161 | if (!bh) { | |
9d9f1775 | 162 | if (!dir_has_error) { |
725bebb2 | 163 | EXT4_ERROR_FILE(file, 0, |
f7c21177 TT |
164 | "directory contains a " |
165 | "hole at offset %llu", | |
725bebb2 | 166 | (unsigned long long) ctx->pos); |
9d9f1775 ES |
167 | dir_has_error = 1; |
168 | } | |
e6c40211 | 169 | /* corrupt size? Maybe no more blocks to read */ |
725bebb2 | 170 | if (ctx->pos > inode->i_blocks << 9) |
e6c40211 | 171 | break; |
725bebb2 | 172 | ctx->pos += sb->s_blocksize - offset; |
ac27a0ec DK |
173 | continue; |
174 | } | |
175 | ||
b0336e8d DW |
176 | /* Check the checksum */ |
177 | if (!buffer_verified(bh) && | |
178 | !ext4_dirent_csum_verify(inode, | |
179 | (struct ext4_dir_entry *)bh->b_data)) { | |
725bebb2 | 180 | EXT4_ERROR_FILE(file, 0, "directory fails checksum " |
b0336e8d | 181 | "at offset %llu", |
725bebb2 AV |
182 | (unsigned long long)ctx->pos); |
183 | ctx->pos += sb->s_blocksize - offset; | |
d5ac7773 | 184 | brelse(bh); |
b0336e8d DW |
185 | continue; |
186 | } | |
187 | set_buffer_verified(bh); | |
188 | ||
ac27a0ec DK |
189 | /* If the dir block has changed since the last call to |
190 | * readdir(2), then we might be pointing to an invalid | |
191 | * dirent right now. Scan from the start of the block | |
192 | * to make sure. */ | |
725bebb2 | 193 | if (file->f_version != inode->i_version) { |
ac27a0ec | 194 | for (i = 0; i < sb->s_blocksize && i < offset; ) { |
617ba13b | 195 | de = (struct ext4_dir_entry_2 *) |
ac27a0ec DK |
196 | (bh->b_data + i); |
197 | /* It's too expensive to do a full | |
198 | * dirent test each time round this | |
199 | * loop, but we do have to test at | |
200 | * least that it is non-zero. A | |
201 | * failure will be detected in the | |
202 | * dirent test below. */ | |
3d0518f4 WY |
203 | if (ext4_rec_len_from_disk(de->rec_len, |
204 | sb->s_blocksize) < EXT4_DIR_REC_LEN(1)) | |
ac27a0ec | 205 | break; |
3d0518f4 WY |
206 | i += ext4_rec_len_from_disk(de->rec_len, |
207 | sb->s_blocksize); | |
ac27a0ec DK |
208 | } |
209 | offset = i; | |
725bebb2 | 210 | ctx->pos = (ctx->pos & ~(sb->s_blocksize - 1)) |
ac27a0ec | 211 | | offset; |
725bebb2 | 212 | file->f_version = inode->i_version; |
ac27a0ec DK |
213 | } |
214 | ||
725bebb2 | 215 | while (ctx->pos < inode->i_size |
ac27a0ec | 216 | && offset < sb->s_blocksize) { |
617ba13b | 217 | de = (struct ext4_dir_entry_2 *) (bh->b_data + offset); |
725bebb2 | 218 | if (ext4_check_dir_entry(inode, file, de, bh, |
226ba972 TM |
219 | bh->b_data, bh->b_size, |
220 | offset)) { | |
63f57933 | 221 | /* |
725bebb2 | 222 | * On error, skip to the next block |
63f57933 | 223 | */ |
725bebb2 | 224 | ctx->pos = (ctx->pos | |
ac27a0ec | 225 | (sb->s_blocksize - 1)) + 1; |
725bebb2 | 226 | break; |
ac27a0ec | 227 | } |
3d0518f4 WY |
228 | offset += ext4_rec_len_from_disk(de->rec_len, |
229 | sb->s_blocksize); | |
ac27a0ec | 230 | if (le32_to_cpu(de->inode)) { |
725bebb2 | 231 | if (!dir_emit(ctx, de->name, |
ac27a0ec | 232 | de->name_len, |
ac27a0ec | 233 | le32_to_cpu(de->inode), |
725bebb2 AV |
234 | get_dtype(sb, de->file_type))) { |
235 | brelse(bh); | |
236 | return 0; | |
237 | } | |
ac27a0ec | 238 | } |
725bebb2 | 239 | ctx->pos += ext4_rec_len_from_disk(de->rec_len, |
3d0518f4 | 240 | sb->s_blocksize); |
ac27a0ec DK |
241 | } |
242 | offset = 0; | |
af5bc92d | 243 | brelse(bh); |
725bebb2 AV |
244 | if (ctx->pos < inode->i_size) { |
245 | if (!dir_relax(inode)) | |
246 | return 0; | |
247 | } | |
ac27a0ec | 248 | } |
725bebb2 | 249 | return 0; |
ac27a0ec DK |
250 | } |
251 | ||
d1f5273e FY |
252 | static inline int is_32bit_api(void) |
253 | { | |
254 | #ifdef CONFIG_COMPAT | |
255 | return is_compat_task(); | |
256 | #else | |
257 | return (BITS_PER_LONG == 32); | |
258 | #endif | |
259 | } | |
260 | ||
ac27a0ec DK |
261 | /* |
262 | * These functions convert from the major/minor hash to an f_pos | |
d1f5273e FY |
263 | * value for dx directories |
264 | * | |
265 | * Upper layer (for example NFS) should specify FMODE_32BITHASH or | |
266 | * FMODE_64BITHASH explicitly. On the other hand, we allow ext4 to be mounted | |
267 | * directly on both 32-bit and 64-bit nodes, under such case, neither | |
268 | * FMODE_32BITHASH nor FMODE_64BITHASH is specified. | |
269 | */ | |
270 | static inline loff_t hash2pos(struct file *filp, __u32 major, __u32 minor) | |
271 | { | |
272 | if ((filp->f_mode & FMODE_32BITHASH) || | |
273 | (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api())) | |
274 | return major >> 1; | |
275 | else | |
276 | return ((__u64)(major >> 1) << 32) | (__u64)minor; | |
277 | } | |
278 | ||
279 | static inline __u32 pos2maj_hash(struct file *filp, loff_t pos) | |
280 | { | |
281 | if ((filp->f_mode & FMODE_32BITHASH) || | |
282 | (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api())) | |
283 | return (pos << 1) & 0xffffffff; | |
284 | else | |
285 | return ((pos >> 32) << 1) & 0xffffffff; | |
286 | } | |
287 | ||
288 | static inline __u32 pos2min_hash(struct file *filp, loff_t pos) | |
289 | { | |
290 | if ((filp->f_mode & FMODE_32BITHASH) || | |
291 | (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api())) | |
292 | return 0; | |
293 | else | |
294 | return pos & 0xffffffff; | |
295 | } | |
296 | ||
297 | /* | |
298 | * Return 32- or 64-bit end-of-file for dx directories | |
299 | */ | |
300 | static inline loff_t ext4_get_htree_eof(struct file *filp) | |
301 | { | |
302 | if ((filp->f_mode & FMODE_32BITHASH) || | |
303 | (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api())) | |
304 | return EXT4_HTREE_EOF_32BIT; | |
305 | else | |
306 | return EXT4_HTREE_EOF_64BIT; | |
307 | } | |
308 | ||
309 | ||
310 | /* | |
ec7268ce ES |
311 | * ext4_dir_llseek() calls generic_file_llseek_size to handle htree |
312 | * directories, where the "offset" is in terms of the filename hash | |
313 | * value instead of the byte offset. | |
ac27a0ec | 314 | * |
ec7268ce ES |
315 | * Because we may return a 64-bit hash that is well beyond offset limits, |
316 | * we need to pass the max hash as the maximum allowable offset in | |
317 | * the htree directory case. | |
318 | * | |
319 | * For non-htree, ext4_llseek already chooses the proper max offset. | |
ac27a0ec | 320 | */ |
d4e43954 | 321 | static loff_t ext4_dir_llseek(struct file *file, loff_t offset, int whence) |
d1f5273e FY |
322 | { |
323 | struct inode *inode = file->f_mapping->host; | |
d1f5273e | 324 | int dx_dir = is_dx_dir(inode); |
ec7268ce | 325 | loff_t htree_max = ext4_get_htree_eof(file); |
d1f5273e | 326 | |
ec7268ce | 327 | if (likely(dx_dir)) |
965c8e59 | 328 | return generic_file_llseek_size(file, offset, whence, |
ec7268ce ES |
329 | htree_max, htree_max); |
330 | else | |
965c8e59 | 331 | return ext4_llseek(file, offset, whence); |
d1f5273e | 332 | } |
ac27a0ec DK |
333 | |
334 | /* | |
335 | * This structure holds the nodes of the red-black tree used to store | |
336 | * the directory entry in hash order. | |
337 | */ | |
338 | struct fname { | |
339 | __u32 hash; | |
340 | __u32 minor_hash; | |
341 | struct rb_node rb_hash; | |
342 | struct fname *next; | |
343 | __u32 inode; | |
344 | __u8 name_len; | |
345 | __u8 file_type; | |
346 | char name[0]; | |
347 | }; | |
348 | ||
349 | /* | |
350 | * This functoin implements a non-recursive way of freeing all of the | |
351 | * nodes in the red-black tree. | |
352 | */ | |
353 | static void free_rb_tree_fname(struct rb_root *root) | |
354 | { | |
d1866bd0 CS |
355 | struct fname *fname, *next; |
356 | ||
357 | rbtree_postorder_for_each_entry_safe(fname, next, root, rb_hash) | |
ac27a0ec | 358 | while (fname) { |
af5bc92d | 359 | struct fname *old = fname; |
ac27a0ec | 360 | fname = fname->next; |
af5bc92d | 361 | kfree(old); |
ac27a0ec | 362 | } |
d1866bd0 CS |
363 | |
364 | *root = RB_ROOT; | |
ac27a0ec DK |
365 | } |
366 | ||
367 | ||
d1f5273e FY |
368 | static struct dir_private_info *ext4_htree_create_dir_info(struct file *filp, |
369 | loff_t pos) | |
ac27a0ec DK |
370 | { |
371 | struct dir_private_info *p; | |
372 | ||
69baee06 | 373 | p = kzalloc(sizeof(struct dir_private_info), GFP_KERNEL); |
ac27a0ec DK |
374 | if (!p) |
375 | return NULL; | |
d1f5273e FY |
376 | p->curr_hash = pos2maj_hash(filp, pos); |
377 | p->curr_minor_hash = pos2min_hash(filp, pos); | |
ac27a0ec DK |
378 | return p; |
379 | } | |
380 | ||
617ba13b | 381 | void ext4_htree_free_dir_info(struct dir_private_info *p) |
ac27a0ec DK |
382 | { |
383 | free_rb_tree_fname(&p->root); | |
384 | kfree(p); | |
385 | } | |
386 | ||
387 | /* | |
388 | * Given a directory entry, enter it into the fname rb tree. | |
389 | */ | |
617ba13b | 390 | int ext4_htree_store_dirent(struct file *dir_file, __u32 hash, |
ac27a0ec | 391 | __u32 minor_hash, |
617ba13b | 392 | struct ext4_dir_entry_2 *dirent) |
ac27a0ec DK |
393 | { |
394 | struct rb_node **p, *parent = NULL; | |
af5bc92d | 395 | struct fname *fname, *new_fn; |
ac27a0ec DK |
396 | struct dir_private_info *info; |
397 | int len; | |
398 | ||
a271fe85 | 399 | info = dir_file->private_data; |
ac27a0ec DK |
400 | p = &info->root.rb_node; |
401 | ||
402 | /* Create and allocate the fname structure */ | |
403 | len = sizeof(struct fname) + dirent->name_len + 1; | |
404 | new_fn = kzalloc(len, GFP_KERNEL); | |
405 | if (!new_fn) | |
406 | return -ENOMEM; | |
407 | new_fn->hash = hash; | |
408 | new_fn->minor_hash = minor_hash; | |
409 | new_fn->inode = le32_to_cpu(dirent->inode); | |
410 | new_fn->name_len = dirent->name_len; | |
411 | new_fn->file_type = dirent->file_type; | |
412 | memcpy(new_fn->name, dirent->name, dirent->name_len); | |
413 | new_fn->name[dirent->name_len] = 0; | |
414 | ||
415 | while (*p) { | |
416 | parent = *p; | |
417 | fname = rb_entry(parent, struct fname, rb_hash); | |
418 | ||
419 | /* | |
420 | * If the hash and minor hash match up, then we put | |
421 | * them on a linked list. This rarely happens... | |
422 | */ | |
423 | if ((new_fn->hash == fname->hash) && | |
424 | (new_fn->minor_hash == fname->minor_hash)) { | |
425 | new_fn->next = fname->next; | |
426 | fname->next = new_fn; | |
427 | return 0; | |
428 | } | |
429 | ||
430 | if (new_fn->hash < fname->hash) | |
431 | p = &(*p)->rb_left; | |
432 | else if (new_fn->hash > fname->hash) | |
433 | p = &(*p)->rb_right; | |
434 | else if (new_fn->minor_hash < fname->minor_hash) | |
435 | p = &(*p)->rb_left; | |
436 | else /* if (new_fn->minor_hash > fname->minor_hash) */ | |
437 | p = &(*p)->rb_right; | |
438 | } | |
439 | ||
440 | rb_link_node(&new_fn->rb_hash, parent, p); | |
441 | rb_insert_color(&new_fn->rb_hash, &info->root); | |
442 | return 0; | |
443 | } | |
444 | ||
445 | ||
446 | ||
447 | /* | |
617ba13b | 448 | * This is a helper function for ext4_dx_readdir. It calls filldir |
ac27a0ec DK |
449 | * for all entres on the fname linked list. (Normally there is only |
450 | * one entry on the linked list, unless there are 62 bit hash collisions.) | |
451 | */ | |
725bebb2 AV |
452 | static int call_filldir(struct file *file, struct dir_context *ctx, |
453 | struct fname *fname) | |
ac27a0ec | 454 | { |
725bebb2 AV |
455 | struct dir_private_info *info = file->private_data; |
456 | struct inode *inode = file_inode(file); | |
457 | struct super_block *sb = inode->i_sb; | |
ac27a0ec DK |
458 | |
459 | if (!fname) { | |
92b97816 TT |
460 | ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: comm %s: " |
461 | "called with null fname?!?", __func__, __LINE__, | |
462 | inode->i_ino, current->comm); | |
ac27a0ec DK |
463 | return 0; |
464 | } | |
725bebb2 | 465 | ctx->pos = hash2pos(file, fname->hash, fname->minor_hash); |
ac27a0ec | 466 | while (fname) { |
725bebb2 AV |
467 | if (!dir_emit(ctx, fname->name, |
468 | fname->name_len, | |
ac27a0ec | 469 | fname->inode, |
725bebb2 | 470 | get_dtype(sb, fname->file_type))) { |
d0156417 | 471 | info->extra_fname = fname; |
725bebb2 | 472 | return 1; |
ac27a0ec DK |
473 | } |
474 | fname = fname->next; | |
475 | } | |
476 | return 0; | |
477 | } | |
478 | ||
725bebb2 | 479 | static int ext4_dx_readdir(struct file *file, struct dir_context *ctx) |
ac27a0ec | 480 | { |
725bebb2 AV |
481 | struct dir_private_info *info = file->private_data; |
482 | struct inode *inode = file_inode(file); | |
ac27a0ec DK |
483 | struct fname *fname; |
484 | int ret; | |
485 | ||
486 | if (!info) { | |
725bebb2 | 487 | info = ext4_htree_create_dir_info(file, ctx->pos); |
ac27a0ec DK |
488 | if (!info) |
489 | return -ENOMEM; | |
725bebb2 | 490 | file->private_data = info; |
ac27a0ec DK |
491 | } |
492 | ||
725bebb2 | 493 | if (ctx->pos == ext4_get_htree_eof(file)) |
ac27a0ec DK |
494 | return 0; /* EOF */ |
495 | ||
496 | /* Some one has messed with f_pos; reset the world */ | |
725bebb2 | 497 | if (info->last_pos != ctx->pos) { |
ac27a0ec DK |
498 | free_rb_tree_fname(&info->root); |
499 | info->curr_node = NULL; | |
500 | info->extra_fname = NULL; | |
725bebb2 AV |
501 | info->curr_hash = pos2maj_hash(file, ctx->pos); |
502 | info->curr_minor_hash = pos2min_hash(file, ctx->pos); | |
ac27a0ec DK |
503 | } |
504 | ||
505 | /* | |
506 | * If there are any leftover names on the hash collision | |
507 | * chain, return them first. | |
508 | */ | |
d0156417 | 509 | if (info->extra_fname) { |
725bebb2 | 510 | if (call_filldir(file, ctx, info->extra_fname)) |
d0156417 | 511 | goto finished; |
d0156417 | 512 | info->extra_fname = NULL; |
3c37fc86 | 513 | goto next_node; |
d0156417 | 514 | } else if (!info->curr_node) |
ac27a0ec DK |
515 | info->curr_node = rb_first(&info->root); |
516 | ||
517 | while (1) { | |
518 | /* | |
519 | * Fill the rbtree if we have no more entries, | |
520 | * or the inode has changed since we last read in the | |
521 | * cached entries. | |
522 | */ | |
523 | if ((!info->curr_node) || | |
725bebb2 | 524 | (file->f_version != inode->i_version)) { |
ac27a0ec DK |
525 | info->curr_node = NULL; |
526 | free_rb_tree_fname(&info->root); | |
725bebb2 AV |
527 | file->f_version = inode->i_version; |
528 | ret = ext4_htree_fill_tree(file, info->curr_hash, | |
ac27a0ec DK |
529 | info->curr_minor_hash, |
530 | &info->next_hash); | |
531 | if (ret < 0) | |
532 | return ret; | |
533 | if (ret == 0) { | |
725bebb2 | 534 | ctx->pos = ext4_get_htree_eof(file); |
ac27a0ec DK |
535 | break; |
536 | } | |
537 | info->curr_node = rb_first(&info->root); | |
538 | } | |
539 | ||
540 | fname = rb_entry(info->curr_node, struct fname, rb_hash); | |
541 | info->curr_hash = fname->hash; | |
542 | info->curr_minor_hash = fname->minor_hash; | |
725bebb2 | 543 | if (call_filldir(file, ctx, fname)) |
ac27a0ec | 544 | break; |
3c37fc86 | 545 | next_node: |
ac27a0ec | 546 | info->curr_node = rb_next(info->curr_node); |
3c37fc86 TT |
547 | if (info->curr_node) { |
548 | fname = rb_entry(info->curr_node, struct fname, | |
549 | rb_hash); | |
550 | info->curr_hash = fname->hash; | |
551 | info->curr_minor_hash = fname->minor_hash; | |
552 | } else { | |
ac27a0ec | 553 | if (info->next_hash == ~0) { |
725bebb2 | 554 | ctx->pos = ext4_get_htree_eof(file); |
ac27a0ec DK |
555 | break; |
556 | } | |
557 | info->curr_hash = info->next_hash; | |
558 | info->curr_minor_hash = 0; | |
559 | } | |
560 | } | |
561 | finished: | |
725bebb2 | 562 | info->last_pos = ctx->pos; |
ac27a0ec DK |
563 | return 0; |
564 | } | |
565 | ||
af5bc92d | 566 | static int ext4_release_dir(struct inode *inode, struct file *filp) |
ac27a0ec | 567 | { |
63f57933 | 568 | if (filp->private_data) |
617ba13b | 569 | ext4_htree_free_dir_info(filp->private_data); |
ac27a0ec DK |
570 | |
571 | return 0; | |
572 | } | |
d1f5273e FY |
573 | |
574 | const struct file_operations ext4_dir_operations = { | |
575 | .llseek = ext4_dir_llseek, | |
576 | .read = generic_read_dir, | |
725bebb2 | 577 | .iterate = ext4_readdir, |
d1f5273e FY |
578 | .unlocked_ioctl = ext4_ioctl, |
579 | #ifdef CONFIG_COMPAT | |
580 | .compat_ioctl = ext4_compat_ioctl, | |
581 | #endif | |
582 | .fsync = ext4_sync_file, | |
583 | .release = ext4_release_dir, | |
584 | }; |