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; | |
f4e420dc CH |
86 | return block_write_begin_newtrunc(NULL, page->mapping, pos, to - from, |
87 | 0, &page, NULL, nilfs_get_block); | |
2ba466d7 YA |
88 | } |
89 | ||
2093abf9 JS |
90 | static void nilfs_commit_chunk(struct page *page, |
91 | struct address_space *mapping, | |
92 | unsigned from, unsigned to) | |
2ba466d7 YA |
93 | { |
94 | struct inode *dir = mapping->host; | |
95 | struct nilfs_sb_info *sbi = NILFS_SB(dir->i_sb); | |
96 | loff_t pos = page_offset(page) + from; | |
97 | unsigned len = to - from; | |
98 | unsigned nr_dirty, copied; | |
99 | int err; | |
100 | ||
101 | nr_dirty = nilfs_page_count_clean_buffers(page, from, to); | |
102 | copied = block_write_end(NULL, mapping, pos, len, len, page, NULL); | |
58d55471 | 103 | if (pos + copied > dir->i_size) |
2ba466d7 | 104 | i_size_write(dir, pos + copied); |
2ba466d7 YA |
105 | if (IS_DIRSYNC(dir)) |
106 | nilfs_set_transaction_flag(NILFS_TI_SYNC); | |
107 | err = nilfs_set_file_dirty(sbi, dir, nr_dirty); | |
2093abf9 | 108 | WARN_ON(err); /* do not happen */ |
2ba466d7 | 109 | unlock_page(page); |
2ba466d7 YA |
110 | } |
111 | ||
112 | static void nilfs_check_page(struct page *page) | |
113 | { | |
114 | struct inode *dir = page->mapping->host; | |
115 | struct super_block *sb = dir->i_sb; | |
116 | unsigned chunk_size = nilfs_chunk_size(dir); | |
117 | char *kaddr = page_address(page); | |
118 | unsigned offs, rec_len; | |
119 | unsigned limit = PAGE_CACHE_SIZE; | |
120 | struct nilfs_dir_entry *p; | |
121 | char *error; | |
122 | ||
123 | if ((dir->i_size >> PAGE_CACHE_SHIFT) == page->index) { | |
124 | limit = dir->i_size & ~PAGE_CACHE_MASK; | |
125 | if (limit & (chunk_size - 1)) | |
126 | goto Ebadsize; | |
127 | if (!limit) | |
128 | goto out; | |
129 | } | |
130 | for (offs = 0; offs <= limit - NILFS_DIR_REC_LEN(1); offs += rec_len) { | |
131 | p = (struct nilfs_dir_entry *)(kaddr + offs); | |
132 | rec_len = le16_to_cpu(p->rec_len); | |
133 | ||
134 | if (rec_len < NILFS_DIR_REC_LEN(1)) | |
135 | goto Eshort; | |
136 | if (rec_len & 3) | |
137 | goto Ealign; | |
138 | if (rec_len < NILFS_DIR_REC_LEN(p->name_len)) | |
139 | goto Enamelen; | |
140 | if (((offs + rec_len - 1) ^ offs) & ~(chunk_size-1)) | |
141 | goto Espan; | |
142 | } | |
143 | if (offs != limit) | |
144 | goto Eend; | |
145 | out: | |
146 | SetPageChecked(page); | |
147 | return; | |
148 | ||
149 | /* Too bad, we had an error */ | |
150 | ||
151 | Ebadsize: | |
152 | nilfs_error(sb, "nilfs_check_page", | |
153 | "size of directory #%lu is not a multiple of chunk size", | |
154 | dir->i_ino | |
155 | ); | |
156 | goto fail; | |
157 | Eshort: | |
158 | error = "rec_len is smaller than minimal"; | |
159 | goto bad_entry; | |
160 | Ealign: | |
161 | error = "unaligned directory entry"; | |
162 | goto bad_entry; | |
163 | Enamelen: | |
164 | error = "rec_len is too small for name_len"; | |
165 | goto bad_entry; | |
166 | Espan: | |
167 | error = "directory entry across blocks"; | |
168 | bad_entry: | |
169 | nilfs_error(sb, "nilfs_check_page", "bad entry in directory #%lu: %s - " | |
170 | "offset=%lu, inode=%lu, rec_len=%d, name_len=%d", | |
171 | dir->i_ino, error, (page->index<<PAGE_CACHE_SHIFT)+offs, | |
172 | (unsigned long) le64_to_cpu(p->inode), | |
173 | rec_len, p->name_len); | |
174 | goto fail; | |
175 | Eend: | |
176 | p = (struct nilfs_dir_entry *)(kaddr + offs); | |
177 | nilfs_error(sb, "nilfs_check_page", | |
178 | "entry in directory #%lu spans the page boundary" | |
179 | "offset=%lu, inode=%lu", | |
180 | dir->i_ino, (page->index<<PAGE_CACHE_SHIFT)+offs, | |
181 | (unsigned long) le64_to_cpu(p->inode)); | |
182 | fail: | |
183 | SetPageChecked(page); | |
184 | SetPageError(page); | |
185 | } | |
186 | ||
187 | static struct page *nilfs_get_page(struct inode *dir, unsigned long n) | |
188 | { | |
189 | struct address_space *mapping = dir->i_mapping; | |
190 | struct page *page = read_cache_page(mapping, n, | |
191 | (filler_t *)mapping->a_ops->readpage, NULL); | |
192 | if (!IS_ERR(page)) { | |
193 | wait_on_page_locked(page); | |
194 | kmap(page); | |
195 | if (!PageUptodate(page)) | |
196 | goto fail; | |
197 | if (!PageChecked(page)) | |
198 | nilfs_check_page(page); | |
199 | if (PageError(page)) | |
200 | goto fail; | |
201 | } | |
202 | return page; | |
203 | ||
204 | fail: | |
205 | nilfs_put_page(page); | |
206 | return ERR_PTR(-EIO); | |
207 | } | |
208 | ||
209 | /* | |
210 | * NOTE! unlike strncmp, nilfs_match returns 1 for success, 0 for failure. | |
211 | * | |
212 | * len <= NILFS_NAME_LEN and de != NULL are guaranteed by caller. | |
213 | */ | |
214 | static int | |
072f98b4 | 215 | nilfs_match(int len, const unsigned char *name, struct nilfs_dir_entry *de) |
2ba466d7 YA |
216 | { |
217 | if (len != de->name_len) | |
218 | return 0; | |
219 | if (!de->inode) | |
220 | return 0; | |
221 | return !memcmp(name, de->name, len); | |
222 | } | |
223 | ||
224 | /* | |
225 | * p is at least 6 bytes before the end of page | |
226 | */ | |
227 | static struct nilfs_dir_entry *nilfs_next_entry(struct nilfs_dir_entry *p) | |
228 | { | |
229 | return (struct nilfs_dir_entry *)((char *)p + le16_to_cpu(p->rec_len)); | |
230 | } | |
231 | ||
232 | static unsigned char | |
233 | nilfs_filetype_table[NILFS_FT_MAX] = { | |
234 | [NILFS_FT_UNKNOWN] = DT_UNKNOWN, | |
235 | [NILFS_FT_REG_FILE] = DT_REG, | |
236 | [NILFS_FT_DIR] = DT_DIR, | |
237 | [NILFS_FT_CHRDEV] = DT_CHR, | |
238 | [NILFS_FT_BLKDEV] = DT_BLK, | |
239 | [NILFS_FT_FIFO] = DT_FIFO, | |
240 | [NILFS_FT_SOCK] = DT_SOCK, | |
241 | [NILFS_FT_SYMLINK] = DT_LNK, | |
242 | }; | |
243 | ||
244 | #define S_SHIFT 12 | |
245 | static unsigned char | |
246 | nilfs_type_by_mode[S_IFMT >> S_SHIFT] = { | |
247 | [S_IFREG >> S_SHIFT] = NILFS_FT_REG_FILE, | |
248 | [S_IFDIR >> S_SHIFT] = NILFS_FT_DIR, | |
249 | [S_IFCHR >> S_SHIFT] = NILFS_FT_CHRDEV, | |
250 | [S_IFBLK >> S_SHIFT] = NILFS_FT_BLKDEV, | |
251 | [S_IFIFO >> S_SHIFT] = NILFS_FT_FIFO, | |
252 | [S_IFSOCK >> S_SHIFT] = NILFS_FT_SOCK, | |
253 | [S_IFLNK >> S_SHIFT] = NILFS_FT_SYMLINK, | |
254 | }; | |
255 | ||
256 | static void nilfs_set_de_type(struct nilfs_dir_entry *de, struct inode *inode) | |
257 | { | |
258 | mode_t mode = inode->i_mode; | |
259 | ||
260 | de->file_type = nilfs_type_by_mode[(mode & S_IFMT)>>S_SHIFT]; | |
261 | } | |
262 | ||
263 | static int nilfs_readdir(struct file *filp, void *dirent, filldir_t filldir) | |
264 | { | |
265 | loff_t pos = filp->f_pos; | |
266 | struct inode *inode = filp->f_dentry->d_inode; | |
267 | struct super_block *sb = inode->i_sb; | |
268 | unsigned int offset = pos & ~PAGE_CACHE_MASK; | |
269 | unsigned long n = pos >> PAGE_CACHE_SHIFT; | |
270 | unsigned long npages = dir_pages(inode); | |
271 | /* unsigned chunk_mask = ~(nilfs_chunk_size(inode)-1); */ | |
272 | unsigned char *types = NULL; | |
273 | int ret; | |
274 | ||
275 | if (pos > inode->i_size - NILFS_DIR_REC_LEN(1)) | |
276 | goto success; | |
277 | ||
278 | types = nilfs_filetype_table; | |
279 | ||
280 | for ( ; n < npages; n++, offset = 0) { | |
281 | char *kaddr, *limit; | |
282 | struct nilfs_dir_entry *de; | |
283 | struct page *page = nilfs_get_page(inode, n); | |
284 | ||
285 | if (IS_ERR(page)) { | |
286 | nilfs_error(sb, __func__, "bad page in #%lu", | |
287 | inode->i_ino); | |
288 | filp->f_pos += PAGE_CACHE_SIZE - offset; | |
289 | ret = -EIO; | |
290 | goto done; | |
291 | } | |
292 | kaddr = page_address(page); | |
293 | de = (struct nilfs_dir_entry *)(kaddr + offset); | |
294 | limit = kaddr + nilfs_last_byte(inode, n) - | |
295 | NILFS_DIR_REC_LEN(1); | |
296 | for ( ; (char *)de <= limit; de = nilfs_next_entry(de)) { | |
297 | if (de->rec_len == 0) { | |
298 | nilfs_error(sb, __func__, | |
299 | "zero-length directory entry"); | |
300 | ret = -EIO; | |
301 | nilfs_put_page(page); | |
302 | goto done; | |
303 | } | |
304 | if (de->inode) { | |
305 | int over; | |
306 | unsigned char d_type = DT_UNKNOWN; | |
307 | ||
308 | if (types && de->file_type < NILFS_FT_MAX) | |
309 | d_type = types[de->file_type]; | |
310 | ||
311 | offset = (char *)de - kaddr; | |
312 | over = filldir(dirent, de->name, de->name_len, | |
313 | (n<<PAGE_CACHE_SHIFT) | offset, | |
314 | le64_to_cpu(de->inode), d_type); | |
315 | if (over) { | |
316 | nilfs_put_page(page); | |
317 | goto success; | |
318 | } | |
319 | } | |
320 | filp->f_pos += le16_to_cpu(de->rec_len); | |
321 | } | |
322 | nilfs_put_page(page); | |
323 | } | |
324 | ||
325 | success: | |
326 | ret = 0; | |
327 | done: | |
328 | return ret; | |
329 | } | |
330 | ||
331 | /* | |
332 | * nilfs_find_entry() | |
333 | * | |
334 | * finds an entry in the specified directory with the wanted name. It | |
335 | * returns the page in which the entry was found, and the entry itself | |
336 | * (as a parameter - res_dir). Page is returned mapped and unlocked. | |
337 | * Entry is guaranteed to be valid. | |
338 | */ | |
339 | struct nilfs_dir_entry * | |
0319003d | 340 | nilfs_find_entry(struct inode *dir, const struct qstr *qstr, |
2ba466d7 YA |
341 | struct page **res_page) |
342 | { | |
0319003d AV |
343 | const unsigned char *name = qstr->name; |
344 | int namelen = qstr->len; | |
2ba466d7 YA |
345 | unsigned reclen = NILFS_DIR_REC_LEN(namelen); |
346 | unsigned long start, n; | |
347 | unsigned long npages = dir_pages(dir); | |
348 | struct page *page = NULL; | |
349 | struct nilfs_inode_info *ei = NILFS_I(dir); | |
350 | struct nilfs_dir_entry *de; | |
351 | ||
352 | if (npages == 0) | |
353 | goto out; | |
354 | ||
355 | /* OFFSET_CACHE */ | |
356 | *res_page = NULL; | |
357 | ||
358 | start = ei->i_dir_start_lookup; | |
359 | if (start >= npages) | |
360 | start = 0; | |
361 | n = start; | |
362 | do { | |
363 | char *kaddr; | |
364 | page = nilfs_get_page(dir, n); | |
365 | if (!IS_ERR(page)) { | |
366 | kaddr = page_address(page); | |
367 | de = (struct nilfs_dir_entry *)kaddr; | |
368 | kaddr += nilfs_last_byte(dir, n) - reclen; | |
369 | while ((char *) de <= kaddr) { | |
370 | if (de->rec_len == 0) { | |
371 | nilfs_error(dir->i_sb, __func__, | |
372 | "zero-length directory entry"); | |
373 | nilfs_put_page(page); | |
374 | goto out; | |
375 | } | |
376 | if (nilfs_match(namelen, name, de)) | |
377 | goto found; | |
378 | de = nilfs_next_entry(de); | |
379 | } | |
380 | nilfs_put_page(page); | |
381 | } | |
382 | if (++n >= npages) | |
383 | n = 0; | |
384 | /* next page is past the blocks we've got */ | |
385 | if (unlikely(n > (dir->i_blocks >> (PAGE_CACHE_SHIFT - 9)))) { | |
386 | nilfs_error(dir->i_sb, __func__, | |
1621562b | 387 | "dir %lu size %lld exceeds block count %llu", |
2ba466d7 YA |
388 | dir->i_ino, dir->i_size, |
389 | (unsigned long long)dir->i_blocks); | |
390 | goto out; | |
391 | } | |
392 | } while (n != start); | |
393 | out: | |
394 | return NULL; | |
395 | ||
396 | found: | |
397 | *res_page = page; | |
398 | ei->i_dir_start_lookup = n; | |
399 | return de; | |
400 | } | |
401 | ||
402 | struct nilfs_dir_entry *nilfs_dotdot(struct inode *dir, struct page **p) | |
403 | { | |
404 | struct page *page = nilfs_get_page(dir, 0); | |
405 | struct nilfs_dir_entry *de = NULL; | |
406 | ||
407 | if (!IS_ERR(page)) { | |
408 | de = nilfs_next_entry( | |
409 | (struct nilfs_dir_entry *)page_address(page)); | |
410 | *p = page; | |
411 | } | |
412 | return de; | |
413 | } | |
414 | ||
0319003d | 415 | ino_t nilfs_inode_by_name(struct inode *dir, const struct qstr *qstr) |
2ba466d7 YA |
416 | { |
417 | ino_t res = 0; | |
418 | struct nilfs_dir_entry *de; | |
419 | struct page *page; | |
420 | ||
0319003d | 421 | de = nilfs_find_entry(dir, qstr, &page); |
2ba466d7 YA |
422 | if (de) { |
423 | res = le64_to_cpu(de->inode); | |
424 | kunmap(page); | |
425 | page_cache_release(page); | |
426 | } | |
427 | return res; | |
428 | } | |
429 | ||
430 | /* Releases the page */ | |
431 | void nilfs_set_link(struct inode *dir, struct nilfs_dir_entry *de, | |
432 | struct page *page, struct inode *inode) | |
433 | { | |
434 | unsigned from = (char *) de - (char *) page_address(page); | |
435 | unsigned to = from + le16_to_cpu(de->rec_len); | |
436 | struct address_space *mapping = page->mapping; | |
437 | int err; | |
438 | ||
439 | lock_page(page); | |
f4e420dc | 440 | err = nilfs_prepare_chunk(page, from, to); |
2ba466d7 YA |
441 | BUG_ON(err); |
442 | de->inode = cpu_to_le64(inode->i_ino); | |
443 | nilfs_set_de_type(de, inode); | |
2093abf9 | 444 | nilfs_commit_chunk(page, mapping, from, to); |
2ba466d7 YA |
445 | nilfs_put_page(page); |
446 | dir->i_mtime = dir->i_ctime = CURRENT_TIME; | |
447 | /* NILFS_I(dir)->i_flags &= ~NILFS_BTREE_FL; */ | |
2ba466d7 YA |
448 | } |
449 | ||
450 | /* | |
451 | * Parent is locked. | |
452 | */ | |
453 | int nilfs_add_link(struct dentry *dentry, struct inode *inode) | |
454 | { | |
455 | struct inode *dir = dentry->d_parent->d_inode; | |
072f98b4 | 456 | const unsigned char *name = dentry->d_name.name; |
2ba466d7 YA |
457 | int namelen = dentry->d_name.len; |
458 | unsigned chunk_size = nilfs_chunk_size(dir); | |
459 | unsigned reclen = NILFS_DIR_REC_LEN(namelen); | |
460 | unsigned short rec_len, name_len; | |
461 | struct page *page = NULL; | |
462 | struct nilfs_dir_entry *de; | |
463 | unsigned long npages = dir_pages(dir); | |
464 | unsigned long n; | |
465 | char *kaddr; | |
466 | unsigned from, to; | |
467 | int err; | |
468 | ||
469 | /* | |
470 | * We take care of directory expansion in the same loop. | |
471 | * This code plays outside i_size, so it locks the page | |
472 | * to protect that region. | |
473 | */ | |
474 | for (n = 0; n <= npages; n++) { | |
475 | char *dir_end; | |
476 | ||
477 | page = nilfs_get_page(dir, n); | |
478 | err = PTR_ERR(page); | |
479 | if (IS_ERR(page)) | |
480 | goto out; | |
481 | lock_page(page); | |
482 | kaddr = page_address(page); | |
483 | dir_end = kaddr + nilfs_last_byte(dir, n); | |
484 | de = (struct nilfs_dir_entry *)kaddr; | |
485 | kaddr += PAGE_CACHE_SIZE - reclen; | |
486 | while ((char *)de <= kaddr) { | |
487 | if ((char *)de == dir_end) { | |
488 | /* We hit i_size */ | |
489 | name_len = 0; | |
490 | rec_len = chunk_size; | |
491 | de->rec_len = cpu_to_le16(chunk_size); | |
492 | de->inode = 0; | |
493 | goto got_it; | |
494 | } | |
495 | if (de->rec_len == 0) { | |
496 | nilfs_error(dir->i_sb, __func__, | |
497 | "zero-length directory entry"); | |
498 | err = -EIO; | |
499 | goto out_unlock; | |
500 | } | |
501 | err = -EEXIST; | |
502 | if (nilfs_match(namelen, name, de)) | |
503 | goto out_unlock; | |
504 | name_len = NILFS_DIR_REC_LEN(de->name_len); | |
505 | rec_len = le16_to_cpu(de->rec_len); | |
506 | if (!de->inode && rec_len >= reclen) | |
507 | goto got_it; | |
508 | if (rec_len >= name_len + reclen) | |
509 | goto got_it; | |
510 | de = (struct nilfs_dir_entry *)((char *)de + rec_len); | |
511 | } | |
512 | unlock_page(page); | |
513 | nilfs_put_page(page); | |
514 | } | |
515 | BUG(); | |
516 | return -EINVAL; | |
517 | ||
518 | got_it: | |
519 | from = (char *)de - (char *)page_address(page); | |
520 | to = from + rec_len; | |
f4e420dc | 521 | err = nilfs_prepare_chunk(page, from, to); |
2ba466d7 YA |
522 | if (err) |
523 | goto out_unlock; | |
524 | if (de->inode) { | |
525 | struct nilfs_dir_entry *de1; | |
526 | ||
527 | de1 = (struct nilfs_dir_entry *)((char *)de + name_len); | |
528 | de1->rec_len = cpu_to_le16(rec_len - name_len); | |
529 | de->rec_len = cpu_to_le16(name_len); | |
530 | de = de1; | |
531 | } | |
532 | de->name_len = namelen; | |
533 | memcpy(de->name, name, namelen); | |
534 | de->inode = cpu_to_le64(inode->i_ino); | |
535 | nilfs_set_de_type(de, inode); | |
2093abf9 | 536 | nilfs_commit_chunk(page, page->mapping, from, to); |
2ba466d7 YA |
537 | dir->i_mtime = dir->i_ctime = CURRENT_TIME; |
538 | /* NILFS_I(dir)->i_flags &= ~NILFS_BTREE_FL; */ | |
abdb318b | 539 | nilfs_mark_inode_dirty(dir); |
2ba466d7 YA |
540 | /* OFFSET_CACHE */ |
541 | out_put: | |
542 | nilfs_put_page(page); | |
543 | out: | |
544 | return err; | |
545 | out_unlock: | |
546 | unlock_page(page); | |
547 | goto out_put; | |
548 | } | |
549 | ||
550 | /* | |
551 | * nilfs_delete_entry deletes a directory entry by merging it with the | |
552 | * previous entry. Page is up-to-date. Releases the page. | |
553 | */ | |
554 | int nilfs_delete_entry(struct nilfs_dir_entry *dir, struct page *page) | |
555 | { | |
556 | struct address_space *mapping = page->mapping; | |
557 | struct inode *inode = mapping->host; | |
558 | char *kaddr = page_address(page); | |
559 | unsigned from = ((char *)dir - kaddr) & ~(nilfs_chunk_size(inode) - 1); | |
560 | unsigned to = ((char *)dir - kaddr) + le16_to_cpu(dir->rec_len); | |
561 | struct nilfs_dir_entry *pde = NULL; | |
562 | struct nilfs_dir_entry *de = (struct nilfs_dir_entry *)(kaddr + from); | |
563 | int err; | |
564 | ||
565 | while ((char *)de < (char *)dir) { | |
566 | if (de->rec_len == 0) { | |
567 | nilfs_error(inode->i_sb, __func__, | |
568 | "zero-length directory entry"); | |
569 | err = -EIO; | |
570 | goto out; | |
571 | } | |
572 | pde = de; | |
573 | de = nilfs_next_entry(de); | |
574 | } | |
575 | if (pde) | |
576 | from = (char *)pde - (char *)page_address(page); | |
577 | lock_page(page); | |
f4e420dc | 578 | err = nilfs_prepare_chunk(page, from, to); |
2ba466d7 YA |
579 | BUG_ON(err); |
580 | if (pde) | |
581 | pde->rec_len = cpu_to_le16(to - from); | |
582 | dir->inode = 0; | |
2093abf9 | 583 | nilfs_commit_chunk(page, mapping, from, to); |
2ba466d7 YA |
584 | inode->i_ctime = inode->i_mtime = CURRENT_TIME; |
585 | /* NILFS_I(inode)->i_flags &= ~NILFS_BTREE_FL; */ | |
2ba466d7 YA |
586 | out: |
587 | nilfs_put_page(page); | |
588 | return err; | |
589 | } | |
590 | ||
591 | /* | |
592 | * Set the first fragment of directory. | |
593 | */ | |
594 | int nilfs_make_empty(struct inode *inode, struct inode *parent) | |
595 | { | |
596 | struct address_space *mapping = inode->i_mapping; | |
597 | struct page *page = grab_cache_page(mapping, 0); | |
598 | unsigned chunk_size = nilfs_chunk_size(inode); | |
599 | struct nilfs_dir_entry *de; | |
600 | int err; | |
601 | void *kaddr; | |
602 | ||
603 | if (!page) | |
604 | return -ENOMEM; | |
605 | ||
f4e420dc | 606 | err = nilfs_prepare_chunk(page, 0, chunk_size); |
2ba466d7 YA |
607 | if (unlikely(err)) { |
608 | unlock_page(page); | |
609 | goto fail; | |
610 | } | |
611 | kaddr = kmap_atomic(page, KM_USER0); | |
612 | memset(kaddr, 0, chunk_size); | |
613 | de = (struct nilfs_dir_entry *)kaddr; | |
614 | de->name_len = 1; | |
615 | de->rec_len = cpu_to_le16(NILFS_DIR_REC_LEN(1)); | |
616 | memcpy(de->name, ".\0\0", 4); | |
617 | de->inode = cpu_to_le64(inode->i_ino); | |
618 | nilfs_set_de_type(de, inode); | |
619 | ||
620 | de = (struct nilfs_dir_entry *)(kaddr + NILFS_DIR_REC_LEN(1)); | |
621 | de->name_len = 2; | |
622 | de->rec_len = cpu_to_le16(chunk_size - NILFS_DIR_REC_LEN(1)); | |
623 | de->inode = cpu_to_le64(parent->i_ino); | |
624 | memcpy(de->name, "..\0", 4); | |
625 | nilfs_set_de_type(de, inode); | |
626 | kunmap_atomic(kaddr, KM_USER0); | |
2093abf9 | 627 | nilfs_commit_chunk(page, mapping, 0, chunk_size); |
2ba466d7 YA |
628 | fail: |
629 | page_cache_release(page); | |
630 | return err; | |
631 | } | |
632 | ||
633 | /* | |
634 | * routine to check that the specified directory is empty (for rmdir) | |
635 | */ | |
636 | int nilfs_empty_dir(struct inode *inode) | |
637 | { | |
638 | struct page *page = NULL; | |
639 | unsigned long i, npages = dir_pages(inode); | |
640 | ||
641 | for (i = 0; i < npages; i++) { | |
642 | char *kaddr; | |
643 | struct nilfs_dir_entry *de; | |
644 | ||
645 | page = nilfs_get_page(inode, i); | |
646 | if (IS_ERR(page)) | |
647 | continue; | |
648 | ||
649 | kaddr = page_address(page); | |
650 | de = (struct nilfs_dir_entry *)kaddr; | |
651 | kaddr += nilfs_last_byte(inode, i) - NILFS_DIR_REC_LEN(1); | |
652 | ||
653 | while ((char *)de <= kaddr) { | |
654 | if (de->rec_len == 0) { | |
655 | nilfs_error(inode->i_sb, __func__, | |
656 | "zero-length directory entry " | |
657 | "(kaddr=%p, de=%p)\n", kaddr, de); | |
658 | goto not_empty; | |
659 | } | |
660 | if (de->inode != 0) { | |
661 | /* check for . and .. */ | |
662 | if (de->name[0] != '.') | |
663 | goto not_empty; | |
664 | if (de->name_len > 2) | |
665 | goto not_empty; | |
666 | if (de->name_len < 2) { | |
667 | if (de->inode != | |
668 | cpu_to_le64(inode->i_ino)) | |
669 | goto not_empty; | |
670 | } else if (de->name[1] != '.') | |
671 | goto not_empty; | |
672 | } | |
673 | de = nilfs_next_entry(de); | |
674 | } | |
675 | nilfs_put_page(page); | |
676 | } | |
677 | return 1; | |
678 | ||
679 | not_empty: | |
680 | nilfs_put_page(page); | |
681 | return 0; | |
682 | } | |
683 | ||
828c0950 | 684 | const struct file_operations nilfs_dir_operations = { |
2ba466d7 YA |
685 | .llseek = generic_file_llseek, |
686 | .read = generic_read_dir, | |
687 | .readdir = nilfs_readdir, | |
7a946193 | 688 | .unlocked_ioctl = nilfs_ioctl, |
2ba466d7 | 689 | #ifdef CONFIG_COMPAT |
8082d36a | 690 | .compat_ioctl = nilfs_ioctl, |
2ba466d7 YA |
691 | #endif /* CONFIG_COMPAT */ |
692 | .fsync = nilfs_sync_file, | |
693 | ||
694 | }; |