Commit | Line | Data |
---|---|---|
2ba466d7 YA |
1 | /* |
2 | * dir.c - NILFS directory entry operations | |
3 | * | |
4 | * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation. | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License as published by | |
8 | * the Free Software Foundation; either version 2 of the License, or | |
9 | * (at your option) any later version. | |
10 | * | |
11 | * This program is distributed in the hope that it will be useful, | |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | * GNU General Public License for more details. | |
15 | * | |
16 | * You should have received a copy of the GNU General Public License | |
17 | * along with this program; if not, write to the Free Software | |
18 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | |
19 | * | |
20 | * Modified for NILFS by Amagai Yoshiji <amagai@osrg.net> | |
21 | */ | |
22 | /* | |
23 | * linux/fs/ext2/dir.c | |
24 | * | |
25 | * Copyright (C) 1992, 1993, 1994, 1995 | |
26 | * Remy Card (card@masi.ibp.fr) | |
27 | * Laboratoire MASI - Institut Blaise Pascal | |
28 | * Universite Pierre et Marie Curie (Paris VI) | |
29 | * | |
30 | * from | |
31 | * | |
32 | * linux/fs/minix/dir.c | |
33 | * | |
34 | * Copyright (C) 1991, 1992 Linus Torvalds | |
35 | * | |
36 | * ext2 directory handling functions | |
37 | * | |
38 | * Big-endian to little-endian byte-swapping/bitmaps by | |
39 | * David S. Miller (davem@caip.rutgers.edu), 1995 | |
40 | * | |
41 | * All code that works with directory layout had been switched to pagecache | |
42 | * and moved here. AV | |
43 | */ | |
44 | ||
45 | #include <linux/pagemap.h> | |
2ba466d7 YA |
46 | #include "nilfs.h" |
47 | #include "page.h" | |
48 | ||
49 | /* | |
50 | * nilfs uses block-sized chunks. Arguably, sector-sized ones would be | |
51 | * more robust, but we have what we have | |
52 | */ | |
53 | static inline unsigned nilfs_chunk_size(struct inode *inode) | |
54 | { | |
55 | return inode->i_sb->s_blocksize; | |
56 | } | |
57 | ||
58 | static inline void nilfs_put_page(struct page *page) | |
59 | { | |
60 | kunmap(page); | |
61 | page_cache_release(page); | |
62 | } | |
63 | ||
64 | static inline unsigned long dir_pages(struct inode *inode) | |
65 | { | |
66 | return (inode->i_size+PAGE_CACHE_SIZE-1)>>PAGE_CACHE_SHIFT; | |
67 | } | |
68 | ||
69 | /* | |
70 | * Return the offset into page `page_nr' of the last valid | |
71 | * byte in that page, plus one. | |
72 | */ | |
73 | static unsigned nilfs_last_byte(struct inode *inode, unsigned long page_nr) | |
74 | { | |
75 | unsigned last_byte = inode->i_size; | |
76 | ||
77 | last_byte -= page_nr << PAGE_CACHE_SHIFT; | |
78 | if (last_byte > PAGE_CACHE_SIZE) | |
79 | last_byte = PAGE_CACHE_SIZE; | |
80 | return last_byte; | |
81 | } | |
82 | ||
f4e420dc | 83 | static int nilfs_prepare_chunk(struct page *page, unsigned from, unsigned to) |
2ba466d7 YA |
84 | { |
85 | loff_t pos = page_offset(page) + from; | |
6e1db88d | 86 | return __block_write_begin(page, pos, to - from, nilfs_get_block); |
2ba466d7 YA |
87 | } |
88 | ||
2093abf9 JS |
89 | static void nilfs_commit_chunk(struct page *page, |
90 | struct address_space *mapping, | |
91 | unsigned from, unsigned to) | |
2ba466d7 YA |
92 | { |
93 | struct inode *dir = mapping->host; | |
2ba466d7 YA |
94 | loff_t pos = page_offset(page) + from; |
95 | unsigned len = to - from; | |
96 | unsigned nr_dirty, copied; | |
97 | int err; | |
98 | ||
99 | nr_dirty = nilfs_page_count_clean_buffers(page, from, to); | |
100 | copied = block_write_end(NULL, mapping, pos, len, len, page, NULL); | |
58d55471 | 101 | if (pos + copied > dir->i_size) |
2ba466d7 | 102 | i_size_write(dir, pos + copied); |
2ba466d7 YA |
103 | if (IS_DIRSYNC(dir)) |
104 | nilfs_set_transaction_flag(NILFS_TI_SYNC); | |
bcbc8c64 | 105 | err = nilfs_set_file_dirty(dir, nr_dirty); |
2093abf9 | 106 | WARN_ON(err); /* do not happen */ |
2ba466d7 | 107 | unlock_page(page); |
2ba466d7 YA |
108 | } |
109 | ||
110 | static void nilfs_check_page(struct page *page) | |
111 | { | |
112 | struct inode *dir = page->mapping->host; | |
113 | struct super_block *sb = dir->i_sb; | |
114 | unsigned chunk_size = nilfs_chunk_size(dir); | |
115 | char *kaddr = page_address(page); | |
116 | unsigned offs, rec_len; | |
117 | unsigned limit = PAGE_CACHE_SIZE; | |
118 | struct nilfs_dir_entry *p; | |
119 | char *error; | |
120 | ||
121 | if ((dir->i_size >> PAGE_CACHE_SHIFT) == page->index) { | |
122 | limit = dir->i_size & ~PAGE_CACHE_MASK; | |
123 | if (limit & (chunk_size - 1)) | |
124 | goto Ebadsize; | |
125 | if (!limit) | |
126 | goto out; | |
127 | } | |
128 | for (offs = 0; offs <= limit - NILFS_DIR_REC_LEN(1); offs += rec_len) { | |
129 | p = (struct nilfs_dir_entry *)(kaddr + offs); | |
6cda9fa2 | 130 | rec_len = nilfs_rec_len_from_disk(p->rec_len); |
2ba466d7 YA |
131 | |
132 | if (rec_len < NILFS_DIR_REC_LEN(1)) | |
133 | goto Eshort; | |
134 | if (rec_len & 3) | |
135 | goto Ealign; | |
136 | if (rec_len < NILFS_DIR_REC_LEN(p->name_len)) | |
137 | goto Enamelen; | |
138 | if (((offs + rec_len - 1) ^ offs) & ~(chunk_size-1)) | |
139 | goto Espan; | |
140 | } | |
141 | if (offs != limit) | |
142 | goto Eend; | |
143 | out: | |
144 | SetPageChecked(page); | |
145 | return; | |
146 | ||
147 | /* Too bad, we had an error */ | |
148 | ||
149 | Ebadsize: | |
150 | nilfs_error(sb, "nilfs_check_page", | |
151 | "size of directory #%lu is not a multiple of chunk size", | |
152 | dir->i_ino | |
153 | ); | |
154 | goto fail; | |
155 | Eshort: | |
156 | error = "rec_len is smaller than minimal"; | |
157 | goto bad_entry; | |
158 | Ealign: | |
159 | error = "unaligned directory entry"; | |
160 | goto bad_entry; | |
161 | Enamelen: | |
162 | error = "rec_len is too small for name_len"; | |
163 | goto bad_entry; | |
164 | Espan: | |
165 | error = "directory entry across blocks"; | |
166 | bad_entry: | |
167 | nilfs_error(sb, "nilfs_check_page", "bad entry in directory #%lu: %s - " | |
168 | "offset=%lu, inode=%lu, rec_len=%d, name_len=%d", | |
169 | dir->i_ino, error, (page->index<<PAGE_CACHE_SHIFT)+offs, | |
170 | (unsigned long) le64_to_cpu(p->inode), | |
171 | rec_len, p->name_len); | |
172 | goto fail; | |
173 | Eend: | |
174 | p = (struct nilfs_dir_entry *)(kaddr + offs); | |
175 | nilfs_error(sb, "nilfs_check_page", | |
176 | "entry in directory #%lu spans the page boundary" | |
177 | "offset=%lu, inode=%lu", | |
178 | dir->i_ino, (page->index<<PAGE_CACHE_SHIFT)+offs, | |
179 | (unsigned long) le64_to_cpu(p->inode)); | |
180 | fail: | |
181 | SetPageChecked(page); | |
182 | SetPageError(page); | |
183 | } | |
184 | ||
185 | static struct page *nilfs_get_page(struct inode *dir, unsigned long n) | |
186 | { | |
187 | struct address_space *mapping = dir->i_mapping; | |
c28e69d9 RK |
188 | struct page *page = read_mapping_page(mapping, n, NULL); |
189 | ||
2ba466d7 | 190 | if (!IS_ERR(page)) { |
2ba466d7 | 191 | kmap(page); |
2ba466d7 YA |
192 | if (!PageChecked(page)) |
193 | nilfs_check_page(page); | |
194 | if (PageError(page)) | |
195 | goto fail; | |
196 | } | |
197 | return page; | |
198 | ||
199 | fail: | |
200 | nilfs_put_page(page); | |
201 | return ERR_PTR(-EIO); | |
202 | } | |
203 | ||
204 | /* | |
205 | * NOTE! unlike strncmp, nilfs_match returns 1 for success, 0 for failure. | |
206 | * | |
207 | * len <= NILFS_NAME_LEN and de != NULL are guaranteed by caller. | |
208 | */ | |
209 | static int | |
072f98b4 | 210 | nilfs_match(int len, const unsigned char *name, struct nilfs_dir_entry *de) |
2ba466d7 YA |
211 | { |
212 | if (len != de->name_len) | |
213 | return 0; | |
214 | if (!de->inode) | |
215 | return 0; | |
216 | return !memcmp(name, de->name, len); | |
217 | } | |
218 | ||
219 | /* | |
220 | * p is at least 6 bytes before the end of page | |
221 | */ | |
222 | static struct nilfs_dir_entry *nilfs_next_entry(struct nilfs_dir_entry *p) | |
223 | { | |
6cda9fa2 RK |
224 | return (struct nilfs_dir_entry *)((char *)p + |
225 | nilfs_rec_len_from_disk(p->rec_len)); | |
2ba466d7 YA |
226 | } |
227 | ||
228 | static unsigned char | |
229 | nilfs_filetype_table[NILFS_FT_MAX] = { | |
230 | [NILFS_FT_UNKNOWN] = DT_UNKNOWN, | |
231 | [NILFS_FT_REG_FILE] = DT_REG, | |
232 | [NILFS_FT_DIR] = DT_DIR, | |
233 | [NILFS_FT_CHRDEV] = DT_CHR, | |
234 | [NILFS_FT_BLKDEV] = DT_BLK, | |
235 | [NILFS_FT_FIFO] = DT_FIFO, | |
236 | [NILFS_FT_SOCK] = DT_SOCK, | |
237 | [NILFS_FT_SYMLINK] = DT_LNK, | |
238 | }; | |
239 | ||
240 | #define S_SHIFT 12 | |
241 | static unsigned char | |
242 | nilfs_type_by_mode[S_IFMT >> S_SHIFT] = { | |
243 | [S_IFREG >> S_SHIFT] = NILFS_FT_REG_FILE, | |
244 | [S_IFDIR >> S_SHIFT] = NILFS_FT_DIR, | |
245 | [S_IFCHR >> S_SHIFT] = NILFS_FT_CHRDEV, | |
246 | [S_IFBLK >> S_SHIFT] = NILFS_FT_BLKDEV, | |
247 | [S_IFIFO >> S_SHIFT] = NILFS_FT_FIFO, | |
248 | [S_IFSOCK >> S_SHIFT] = NILFS_FT_SOCK, | |
249 | [S_IFLNK >> S_SHIFT] = NILFS_FT_SYMLINK, | |
250 | }; | |
251 | ||
252 | static void nilfs_set_de_type(struct nilfs_dir_entry *de, struct inode *inode) | |
253 | { | |
c6e49e3f | 254 | umode_t mode = inode->i_mode; |
2ba466d7 YA |
255 | |
256 | de->file_type = nilfs_type_by_mode[(mode & S_IFMT)>>S_SHIFT]; | |
257 | } | |
258 | ||
1616abe8 | 259 | static int nilfs_readdir(struct file *file, struct dir_context *ctx) |
2ba466d7 | 260 | { |
1616abe8 AV |
261 | loff_t pos = ctx->pos; |
262 | struct inode *inode = file_inode(file); | |
2ba466d7 YA |
263 | struct super_block *sb = inode->i_sb; |
264 | unsigned int offset = pos & ~PAGE_CACHE_MASK; | |
265 | unsigned long n = pos >> PAGE_CACHE_SHIFT; | |
266 | unsigned long npages = dir_pages(inode); | |
267 | /* unsigned chunk_mask = ~(nilfs_chunk_size(inode)-1); */ | |
2ba466d7 YA |
268 | |
269 | if (pos > inode->i_size - NILFS_DIR_REC_LEN(1)) | |
1616abe8 | 270 | return 0; |
2ba466d7 YA |
271 | |
272 | for ( ; n < npages; n++, offset = 0) { | |
273 | char *kaddr, *limit; | |
274 | struct nilfs_dir_entry *de; | |
275 | struct page *page = nilfs_get_page(inode, n); | |
276 | ||
277 | if (IS_ERR(page)) { | |
278 | nilfs_error(sb, __func__, "bad page in #%lu", | |
279 | inode->i_ino); | |
1616abe8 AV |
280 | ctx->pos += PAGE_CACHE_SIZE - offset; |
281 | return -EIO; | |
2ba466d7 YA |
282 | } |
283 | kaddr = page_address(page); | |
284 | de = (struct nilfs_dir_entry *)(kaddr + offset); | |
285 | limit = kaddr + nilfs_last_byte(inode, n) - | |
286 | NILFS_DIR_REC_LEN(1); | |
287 | for ( ; (char *)de <= limit; de = nilfs_next_entry(de)) { | |
288 | if (de->rec_len == 0) { | |
289 | nilfs_error(sb, __func__, | |
290 | "zero-length directory entry"); | |
2ba466d7 | 291 | nilfs_put_page(page); |
1616abe8 | 292 | return -EIO; |
2ba466d7 YA |
293 | } |
294 | if (de->inode) { | |
1616abe8 | 295 | unsigned char t; |
2ba466d7 | 296 | |
1616abe8 AV |
297 | if (de->file_type < NILFS_FT_MAX) |
298 | t = nilfs_filetype_table[de->file_type]; | |
299 | else | |
300 | t = DT_UNKNOWN; | |
2ba466d7 | 301 | |
1616abe8 AV |
302 | if (!dir_emit(ctx, de->name, de->name_len, |
303 | le64_to_cpu(de->inode), t)) { | |
2ba466d7 | 304 | nilfs_put_page(page); |
1616abe8 | 305 | return 0; |
2ba466d7 YA |
306 | } |
307 | } | |
1616abe8 | 308 | ctx->pos += nilfs_rec_len_from_disk(de->rec_len); |
2ba466d7 YA |
309 | } |
310 | nilfs_put_page(page); | |
311 | } | |
1616abe8 | 312 | return 0; |
2ba466d7 YA |
313 | } |
314 | ||
315 | /* | |
316 | * nilfs_find_entry() | |
317 | * | |
318 | * finds an entry in the specified directory with the wanted name. It | |
319 | * returns the page in which the entry was found, and the entry itself | |
320 | * (as a parameter - res_dir). Page is returned mapped and unlocked. | |
321 | * Entry is guaranteed to be valid. | |
322 | */ | |
323 | struct nilfs_dir_entry * | |
0319003d | 324 | nilfs_find_entry(struct inode *dir, const struct qstr *qstr, |
2ba466d7 YA |
325 | struct page **res_page) |
326 | { | |
0319003d AV |
327 | const unsigned char *name = qstr->name; |
328 | int namelen = qstr->len; | |
2ba466d7 YA |
329 | unsigned reclen = NILFS_DIR_REC_LEN(namelen); |
330 | unsigned long start, n; | |
331 | unsigned long npages = dir_pages(dir); | |
332 | struct page *page = NULL; | |
333 | struct nilfs_inode_info *ei = NILFS_I(dir); | |
334 | struct nilfs_dir_entry *de; | |
335 | ||
336 | if (npages == 0) | |
337 | goto out; | |
338 | ||
339 | /* OFFSET_CACHE */ | |
340 | *res_page = NULL; | |
341 | ||
342 | start = ei->i_dir_start_lookup; | |
343 | if (start >= npages) | |
344 | start = 0; | |
345 | n = start; | |
346 | do { | |
347 | char *kaddr; | |
348 | page = nilfs_get_page(dir, n); | |
349 | if (!IS_ERR(page)) { | |
350 | kaddr = page_address(page); | |
351 | de = (struct nilfs_dir_entry *)kaddr; | |
352 | kaddr += nilfs_last_byte(dir, n) - reclen; | |
353 | while ((char *) de <= kaddr) { | |
354 | if (de->rec_len == 0) { | |
355 | nilfs_error(dir->i_sb, __func__, | |
356 | "zero-length directory entry"); | |
357 | nilfs_put_page(page); | |
358 | goto out; | |
359 | } | |
360 | if (nilfs_match(namelen, name, de)) | |
361 | goto found; | |
362 | de = nilfs_next_entry(de); | |
363 | } | |
364 | nilfs_put_page(page); | |
365 | } | |
366 | if (++n >= npages) | |
367 | n = 0; | |
368 | /* next page is past the blocks we've got */ | |
369 | if (unlikely(n > (dir->i_blocks >> (PAGE_CACHE_SHIFT - 9)))) { | |
370 | nilfs_error(dir->i_sb, __func__, | |
1621562b | 371 | "dir %lu size %lld exceeds block count %llu", |
2ba466d7 YA |
372 | dir->i_ino, dir->i_size, |
373 | (unsigned long long)dir->i_blocks); | |
374 | goto out; | |
375 | } | |
376 | } while (n != start); | |
377 | out: | |
378 | return NULL; | |
379 | ||
380 | found: | |
381 | *res_page = page; | |
382 | ei->i_dir_start_lookup = n; | |
383 | return de; | |
384 | } | |
385 | ||
386 | struct nilfs_dir_entry *nilfs_dotdot(struct inode *dir, struct page **p) | |
387 | { | |
388 | struct page *page = nilfs_get_page(dir, 0); | |
389 | struct nilfs_dir_entry *de = NULL; | |
390 | ||
391 | if (!IS_ERR(page)) { | |
392 | de = nilfs_next_entry( | |
393 | (struct nilfs_dir_entry *)page_address(page)); | |
394 | *p = page; | |
395 | } | |
396 | return de; | |
397 | } | |
398 | ||
0319003d | 399 | ino_t nilfs_inode_by_name(struct inode *dir, const struct qstr *qstr) |
2ba466d7 YA |
400 | { |
401 | ino_t res = 0; | |
402 | struct nilfs_dir_entry *de; | |
403 | struct page *page; | |
404 | ||
0319003d | 405 | de = nilfs_find_entry(dir, qstr, &page); |
2ba466d7 YA |
406 | if (de) { |
407 | res = le64_to_cpu(de->inode); | |
408 | kunmap(page); | |
409 | page_cache_release(page); | |
410 | } | |
411 | return res; | |
412 | } | |
413 | ||
414 | /* Releases the page */ | |
415 | void nilfs_set_link(struct inode *dir, struct nilfs_dir_entry *de, | |
416 | struct page *page, struct inode *inode) | |
417 | { | |
418 | unsigned from = (char *) de - (char *) page_address(page); | |
6cda9fa2 | 419 | unsigned to = from + nilfs_rec_len_from_disk(de->rec_len); |
2ba466d7 YA |
420 | struct address_space *mapping = page->mapping; |
421 | int err; | |
422 | ||
423 | lock_page(page); | |
f4e420dc | 424 | err = nilfs_prepare_chunk(page, from, to); |
2ba466d7 YA |
425 | BUG_ON(err); |
426 | de->inode = cpu_to_le64(inode->i_ino); | |
427 | nilfs_set_de_type(de, inode); | |
2093abf9 | 428 | nilfs_commit_chunk(page, mapping, from, to); |
2ba466d7 YA |
429 | nilfs_put_page(page); |
430 | dir->i_mtime = dir->i_ctime = CURRENT_TIME; | |
2ba466d7 YA |
431 | } |
432 | ||
433 | /* | |
434 | * Parent is locked. | |
435 | */ | |
436 | int nilfs_add_link(struct dentry *dentry, struct inode *inode) | |
437 | { | |
438 | struct inode *dir = dentry->d_parent->d_inode; | |
072f98b4 | 439 | const unsigned char *name = dentry->d_name.name; |
2ba466d7 YA |
440 | int namelen = dentry->d_name.len; |
441 | unsigned chunk_size = nilfs_chunk_size(dir); | |
442 | unsigned reclen = NILFS_DIR_REC_LEN(namelen); | |
443 | unsigned short rec_len, name_len; | |
444 | struct page *page = NULL; | |
445 | struct nilfs_dir_entry *de; | |
446 | unsigned long npages = dir_pages(dir); | |
447 | unsigned long n; | |
448 | char *kaddr; | |
449 | unsigned from, to; | |
450 | int err; | |
451 | ||
452 | /* | |
453 | * We take care of directory expansion in the same loop. | |
454 | * This code plays outside i_size, so it locks the page | |
455 | * to protect that region. | |
456 | */ | |
457 | for (n = 0; n <= npages; n++) { | |
458 | char *dir_end; | |
459 | ||
460 | page = nilfs_get_page(dir, n); | |
461 | err = PTR_ERR(page); | |
462 | if (IS_ERR(page)) | |
463 | goto out; | |
464 | lock_page(page); | |
465 | kaddr = page_address(page); | |
466 | dir_end = kaddr + nilfs_last_byte(dir, n); | |
467 | de = (struct nilfs_dir_entry *)kaddr; | |
468 | kaddr += PAGE_CACHE_SIZE - reclen; | |
469 | while ((char *)de <= kaddr) { | |
470 | if ((char *)de == dir_end) { | |
471 | /* We hit i_size */ | |
472 | name_len = 0; | |
473 | rec_len = chunk_size; | |
6cda9fa2 | 474 | de->rec_len = nilfs_rec_len_to_disk(chunk_size); |
2ba466d7 YA |
475 | de->inode = 0; |
476 | goto got_it; | |
477 | } | |
478 | if (de->rec_len == 0) { | |
479 | nilfs_error(dir->i_sb, __func__, | |
480 | "zero-length directory entry"); | |
481 | err = -EIO; | |
482 | goto out_unlock; | |
483 | } | |
484 | err = -EEXIST; | |
485 | if (nilfs_match(namelen, name, de)) | |
486 | goto out_unlock; | |
487 | name_len = NILFS_DIR_REC_LEN(de->name_len); | |
6cda9fa2 | 488 | rec_len = nilfs_rec_len_from_disk(de->rec_len); |
2ba466d7 YA |
489 | if (!de->inode && rec_len >= reclen) |
490 | goto got_it; | |
491 | if (rec_len >= name_len + reclen) | |
492 | goto got_it; | |
493 | de = (struct nilfs_dir_entry *)((char *)de + rec_len); | |
494 | } | |
495 | unlock_page(page); | |
496 | nilfs_put_page(page); | |
497 | } | |
498 | BUG(); | |
499 | return -EINVAL; | |
500 | ||
501 | got_it: | |
502 | from = (char *)de - (char *)page_address(page); | |
503 | to = from + rec_len; | |
f4e420dc | 504 | err = nilfs_prepare_chunk(page, from, to); |
2ba466d7 YA |
505 | if (err) |
506 | goto out_unlock; | |
507 | if (de->inode) { | |
508 | struct nilfs_dir_entry *de1; | |
509 | ||
510 | de1 = (struct nilfs_dir_entry *)((char *)de + name_len); | |
6cda9fa2 RK |
511 | de1->rec_len = nilfs_rec_len_to_disk(rec_len - name_len); |
512 | de->rec_len = nilfs_rec_len_to_disk(name_len); | |
2ba466d7 YA |
513 | de = de1; |
514 | } | |
515 | de->name_len = namelen; | |
516 | memcpy(de->name, name, namelen); | |
517 | de->inode = cpu_to_le64(inode->i_ino); | |
518 | nilfs_set_de_type(de, inode); | |
2093abf9 | 519 | nilfs_commit_chunk(page, page->mapping, from, to); |
2ba466d7 | 520 | dir->i_mtime = dir->i_ctime = CURRENT_TIME; |
abdb318b | 521 | nilfs_mark_inode_dirty(dir); |
2ba466d7 YA |
522 | /* OFFSET_CACHE */ |
523 | out_put: | |
524 | nilfs_put_page(page); | |
525 | out: | |
526 | return err; | |
527 | out_unlock: | |
528 | unlock_page(page); | |
529 | goto out_put; | |
530 | } | |
531 | ||
532 | /* | |
533 | * nilfs_delete_entry deletes a directory entry by merging it with the | |
534 | * previous entry. Page is up-to-date. Releases the page. | |
535 | */ | |
536 | int nilfs_delete_entry(struct nilfs_dir_entry *dir, struct page *page) | |
537 | { | |
538 | struct address_space *mapping = page->mapping; | |
539 | struct inode *inode = mapping->host; | |
540 | char *kaddr = page_address(page); | |
541 | unsigned from = ((char *)dir - kaddr) & ~(nilfs_chunk_size(inode) - 1); | |
6cda9fa2 RK |
542 | unsigned to = ((char *)dir - kaddr) + |
543 | nilfs_rec_len_from_disk(dir->rec_len); | |
2ba466d7 YA |
544 | struct nilfs_dir_entry *pde = NULL; |
545 | struct nilfs_dir_entry *de = (struct nilfs_dir_entry *)(kaddr + from); | |
546 | int err; | |
547 | ||
548 | while ((char *)de < (char *)dir) { | |
549 | if (de->rec_len == 0) { | |
550 | nilfs_error(inode->i_sb, __func__, | |
551 | "zero-length directory entry"); | |
552 | err = -EIO; | |
553 | goto out; | |
554 | } | |
555 | pde = de; | |
556 | de = nilfs_next_entry(de); | |
557 | } | |
558 | if (pde) | |
559 | from = (char *)pde - (char *)page_address(page); | |
560 | lock_page(page); | |
f4e420dc | 561 | err = nilfs_prepare_chunk(page, from, to); |
2ba466d7 YA |
562 | BUG_ON(err); |
563 | if (pde) | |
6cda9fa2 | 564 | pde->rec_len = nilfs_rec_len_to_disk(to - from); |
2ba466d7 | 565 | dir->inode = 0; |
2093abf9 | 566 | nilfs_commit_chunk(page, mapping, from, to); |
2ba466d7 | 567 | inode->i_ctime = inode->i_mtime = CURRENT_TIME; |
2ba466d7 YA |
568 | out: |
569 | nilfs_put_page(page); | |
570 | return err; | |
571 | } | |
572 | ||
573 | /* | |
574 | * Set the first fragment of directory. | |
575 | */ | |
576 | int nilfs_make_empty(struct inode *inode, struct inode *parent) | |
577 | { | |
578 | struct address_space *mapping = inode->i_mapping; | |
579 | struct page *page = grab_cache_page(mapping, 0); | |
580 | unsigned chunk_size = nilfs_chunk_size(inode); | |
581 | struct nilfs_dir_entry *de; | |
582 | int err; | |
583 | void *kaddr; | |
584 | ||
585 | if (!page) | |
586 | return -ENOMEM; | |
587 | ||
f4e420dc | 588 | err = nilfs_prepare_chunk(page, 0, chunk_size); |
2ba466d7 YA |
589 | if (unlikely(err)) { |
590 | unlock_page(page); | |
591 | goto fail; | |
592 | } | |
7b9c0976 | 593 | kaddr = kmap_atomic(page); |
2ba466d7 YA |
594 | memset(kaddr, 0, chunk_size); |
595 | de = (struct nilfs_dir_entry *)kaddr; | |
596 | de->name_len = 1; | |
6cda9fa2 | 597 | de->rec_len = nilfs_rec_len_to_disk(NILFS_DIR_REC_LEN(1)); |
2ba466d7 YA |
598 | memcpy(de->name, ".\0\0", 4); |
599 | de->inode = cpu_to_le64(inode->i_ino); | |
600 | nilfs_set_de_type(de, inode); | |
601 | ||
602 | de = (struct nilfs_dir_entry *)(kaddr + NILFS_DIR_REC_LEN(1)); | |
603 | de->name_len = 2; | |
6cda9fa2 | 604 | de->rec_len = nilfs_rec_len_to_disk(chunk_size - NILFS_DIR_REC_LEN(1)); |
2ba466d7 YA |
605 | de->inode = cpu_to_le64(parent->i_ino); |
606 | memcpy(de->name, "..\0", 4); | |
607 | nilfs_set_de_type(de, inode); | |
7b9c0976 | 608 | kunmap_atomic(kaddr); |
2093abf9 | 609 | nilfs_commit_chunk(page, mapping, 0, chunk_size); |
2ba466d7 YA |
610 | fail: |
611 | page_cache_release(page); | |
612 | return err; | |
613 | } | |
614 | ||
615 | /* | |
616 | * routine to check that the specified directory is empty (for rmdir) | |
617 | */ | |
618 | int nilfs_empty_dir(struct inode *inode) | |
619 | { | |
620 | struct page *page = NULL; | |
621 | unsigned long i, npages = dir_pages(inode); | |
622 | ||
623 | for (i = 0; i < npages; i++) { | |
624 | char *kaddr; | |
625 | struct nilfs_dir_entry *de; | |
626 | ||
627 | page = nilfs_get_page(inode, i); | |
628 | if (IS_ERR(page)) | |
629 | continue; | |
630 | ||
631 | kaddr = page_address(page); | |
632 | de = (struct nilfs_dir_entry *)kaddr; | |
633 | kaddr += nilfs_last_byte(inode, i) - NILFS_DIR_REC_LEN(1); | |
634 | ||
635 | while ((char *)de <= kaddr) { | |
636 | if (de->rec_len == 0) { | |
637 | nilfs_error(inode->i_sb, __func__, | |
638 | "zero-length directory entry " | |
639 | "(kaddr=%p, de=%p)\n", kaddr, de); | |
640 | goto not_empty; | |
641 | } | |
642 | if (de->inode != 0) { | |
643 | /* check for . and .. */ | |
644 | if (de->name[0] != '.') | |
645 | goto not_empty; | |
646 | if (de->name_len > 2) | |
647 | goto not_empty; | |
648 | if (de->name_len < 2) { | |
649 | if (de->inode != | |
650 | cpu_to_le64(inode->i_ino)) | |
651 | goto not_empty; | |
652 | } else if (de->name[1] != '.') | |
653 | goto not_empty; | |
654 | } | |
655 | de = nilfs_next_entry(de); | |
656 | } | |
657 | nilfs_put_page(page); | |
658 | } | |
659 | return 1; | |
660 | ||
661 | not_empty: | |
662 | nilfs_put_page(page); | |
663 | return 0; | |
664 | } | |
665 | ||
828c0950 | 666 | const struct file_operations nilfs_dir_operations = { |
2ba466d7 YA |
667 | .llseek = generic_file_llseek, |
668 | .read = generic_read_dir, | |
1616abe8 | 669 | .iterate = nilfs_readdir, |
7a946193 | 670 | .unlocked_ioctl = nilfs_ioctl, |
2ba466d7 | 671 | #ifdef CONFIG_COMPAT |
828b1c50 | 672 | .compat_ioctl = nilfs_compat_ioctl, |
2ba466d7 YA |
673 | #endif /* CONFIG_COMPAT */ |
674 | .fsync = nilfs_sync_file, | |
675 | ||
676 | }; |