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 | * | |
4b420ab4 | 16 | * Modified for NILFS by Amagai Yoshiji. |
2ba466d7 YA |
17 | */ |
18 | /* | |
19 | * linux/fs/ext2/dir.c | |
20 | * | |
21 | * Copyright (C) 1992, 1993, 1994, 1995 | |
22 | * Remy Card (card@masi.ibp.fr) | |
23 | * Laboratoire MASI - Institut Blaise Pascal | |
24 | * Universite Pierre et Marie Curie (Paris VI) | |
25 | * | |
26 | * from | |
27 | * | |
28 | * linux/fs/minix/dir.c | |
29 | * | |
30 | * Copyright (C) 1991, 1992 Linus Torvalds | |
31 | * | |
32 | * ext2 directory handling functions | |
33 | * | |
34 | * Big-endian to little-endian byte-swapping/bitmaps by | |
35 | * David S. Miller (davem@caip.rutgers.edu), 1995 | |
36 | * | |
37 | * All code that works with directory layout had been switched to pagecache | |
38 | * and moved here. AV | |
39 | */ | |
40 | ||
41 | #include <linux/pagemap.h> | |
2ba466d7 YA |
42 | #include "nilfs.h" |
43 | #include "page.h" | |
44 | ||
45 | /* | |
46 | * nilfs uses block-sized chunks. Arguably, sector-sized ones would be | |
47 | * more robust, but we have what we have | |
48 | */ | |
0c6c44cb | 49 | static inline unsigned int nilfs_chunk_size(struct inode *inode) |
2ba466d7 YA |
50 | { |
51 | return inode->i_sb->s_blocksize; | |
52 | } | |
53 | ||
54 | static inline void nilfs_put_page(struct page *page) | |
55 | { | |
56 | kunmap(page); | |
09cbfeaf | 57 | put_page(page); |
2ba466d7 YA |
58 | } |
59 | ||
2ba466d7 YA |
60 | /* |
61 | * Return the offset into page `page_nr' of the last valid | |
62 | * byte in that page, plus one. | |
63 | */ | |
0c6c44cb | 64 | static unsigned int nilfs_last_byte(struct inode *inode, unsigned long page_nr) |
2ba466d7 | 65 | { |
0c6c44cb | 66 | unsigned int last_byte = inode->i_size; |
2ba466d7 | 67 | |
09cbfeaf KS |
68 | last_byte -= page_nr << PAGE_SHIFT; |
69 | if (last_byte > PAGE_SIZE) | |
70 | last_byte = PAGE_SIZE; | |
2ba466d7 YA |
71 | return last_byte; |
72 | } | |
73 | ||
0c6c44cb RK |
74 | static int nilfs_prepare_chunk(struct page *page, unsigned int from, |
75 | unsigned int to) | |
2ba466d7 YA |
76 | { |
77 | loff_t pos = page_offset(page) + from; | |
4ad364ca | 78 | |
6e1db88d | 79 | return __block_write_begin(page, pos, to - from, nilfs_get_block); |
2ba466d7 YA |
80 | } |
81 | ||
2093abf9 JS |
82 | static void nilfs_commit_chunk(struct page *page, |
83 | struct address_space *mapping, | |
0c6c44cb | 84 | unsigned int from, unsigned int to) |
2ba466d7 YA |
85 | { |
86 | struct inode *dir = mapping->host; | |
2ba466d7 | 87 | loff_t pos = page_offset(page) + from; |
0c6c44cb RK |
88 | unsigned int len = to - from; |
89 | unsigned int nr_dirty, copied; | |
2ba466d7 YA |
90 | int err; |
91 | ||
92 | nr_dirty = nilfs_page_count_clean_buffers(page, from, to); | |
93 | copied = block_write_end(NULL, mapping, pos, len, len, page, NULL); | |
58d55471 | 94 | if (pos + copied > dir->i_size) |
2ba466d7 | 95 | i_size_write(dir, pos + copied); |
2ba466d7 YA |
96 | if (IS_DIRSYNC(dir)) |
97 | nilfs_set_transaction_flag(NILFS_TI_SYNC); | |
bcbc8c64 | 98 | err = nilfs_set_file_dirty(dir, nr_dirty); |
2093abf9 | 99 | WARN_ON(err); /* do not happen */ |
2ba466d7 | 100 | unlock_page(page); |
2ba466d7 YA |
101 | } |
102 | ||
be5b82db | 103 | static bool nilfs_check_page(struct page *page) |
2ba466d7 YA |
104 | { |
105 | struct inode *dir = page->mapping->host; | |
106 | struct super_block *sb = dir->i_sb; | |
0c6c44cb | 107 | unsigned int chunk_size = nilfs_chunk_size(dir); |
2ba466d7 | 108 | char *kaddr = page_address(page); |
0c6c44cb RK |
109 | unsigned int offs, rec_len; |
110 | unsigned int limit = PAGE_SIZE; | |
2ba466d7 YA |
111 | struct nilfs_dir_entry *p; |
112 | char *error; | |
113 | ||
09cbfeaf KS |
114 | if ((dir->i_size >> PAGE_SHIFT) == page->index) { |
115 | limit = dir->i_size & ~PAGE_MASK; | |
2ba466d7 YA |
116 | if (limit & (chunk_size - 1)) |
117 | goto Ebadsize; | |
118 | if (!limit) | |
119 | goto out; | |
120 | } | |
121 | for (offs = 0; offs <= limit - NILFS_DIR_REC_LEN(1); offs += rec_len) { | |
122 | p = (struct nilfs_dir_entry *)(kaddr + offs); | |
6cda9fa2 | 123 | rec_len = nilfs_rec_len_from_disk(p->rec_len); |
2ba466d7 YA |
124 | |
125 | if (rec_len < NILFS_DIR_REC_LEN(1)) | |
126 | goto Eshort; | |
127 | if (rec_len & 3) | |
128 | goto Ealign; | |
129 | if (rec_len < NILFS_DIR_REC_LEN(p->name_len)) | |
130 | goto Enamelen; | |
131 | if (((offs + rec_len - 1) ^ offs) & ~(chunk_size-1)) | |
132 | goto Espan; | |
133 | } | |
134 | if (offs != limit) | |
135 | goto Eend; | |
136 | out: | |
137 | SetPageChecked(page); | |
be5b82db | 138 | return true; |
2ba466d7 YA |
139 | |
140 | /* Too bad, we had an error */ | |
141 | ||
142 | Ebadsize: | |
cae3d4ca | 143 | nilfs_error(sb, |
2ba466d7 | 144 | "size of directory #%lu is not a multiple of chunk size", |
cae3d4ca | 145 | dir->i_ino); |
2ba466d7 YA |
146 | goto fail; |
147 | Eshort: | |
148 | error = "rec_len is smaller than minimal"; | |
149 | goto bad_entry; | |
150 | Ealign: | |
151 | error = "unaligned directory entry"; | |
152 | goto bad_entry; | |
153 | Enamelen: | |
154 | error = "rec_len is too small for name_len"; | |
155 | goto bad_entry; | |
156 | Espan: | |
157 | error = "directory entry across blocks"; | |
158 | bad_entry: | |
cae3d4ca RK |
159 | nilfs_error(sb, |
160 | "bad entry in directory #%lu: %s - offset=%lu, inode=%lu, rec_len=%d, name_len=%d", | |
161 | dir->i_ino, error, (page->index << PAGE_SHIFT) + offs, | |
162 | (unsigned long)le64_to_cpu(p->inode), | |
2ba466d7 YA |
163 | rec_len, p->name_len); |
164 | goto fail; | |
165 | Eend: | |
166 | p = (struct nilfs_dir_entry *)(kaddr + offs); | |
cae3d4ca RK |
167 | nilfs_error(sb, |
168 | "entry in directory #%lu spans the page boundary offset=%lu, inode=%lu", | |
169 | dir->i_ino, (page->index << PAGE_SHIFT) + offs, | |
170 | (unsigned long)le64_to_cpu(p->inode)); | |
2ba466d7 | 171 | fail: |
2ba466d7 | 172 | SetPageError(page); |
be5b82db | 173 | return false; |
2ba466d7 YA |
174 | } |
175 | ||
176 | static struct page *nilfs_get_page(struct inode *dir, unsigned long n) | |
177 | { | |
178 | struct address_space *mapping = dir->i_mapping; | |
c28e69d9 RK |
179 | struct page *page = read_mapping_page(mapping, n, NULL); |
180 | ||
2ba466d7 | 181 | if (!IS_ERR(page)) { |
2ba466d7 | 182 | kmap(page); |
be5b82db AV |
183 | if (unlikely(!PageChecked(page))) { |
184 | if (PageError(page) || !nilfs_check_page(page)) | |
185 | goto fail; | |
186 | } | |
2ba466d7 YA |
187 | } |
188 | return page; | |
189 | ||
190 | fail: | |
191 | nilfs_put_page(page); | |
192 | return ERR_PTR(-EIO); | |
193 | } | |
194 | ||
195 | /* | |
196 | * NOTE! unlike strncmp, nilfs_match returns 1 for success, 0 for failure. | |
197 | * | |
198 | * len <= NILFS_NAME_LEN and de != NULL are guaranteed by caller. | |
199 | */ | |
200 | static int | |
072f98b4 | 201 | nilfs_match(int len, const unsigned char *name, struct nilfs_dir_entry *de) |
2ba466d7 YA |
202 | { |
203 | if (len != de->name_len) | |
204 | return 0; | |
205 | if (!de->inode) | |
206 | return 0; | |
207 | return !memcmp(name, de->name, len); | |
208 | } | |
209 | ||
210 | /* | |
211 | * p is at least 6 bytes before the end of page | |
212 | */ | |
213 | static struct nilfs_dir_entry *nilfs_next_entry(struct nilfs_dir_entry *p) | |
214 | { | |
6cda9fa2 RK |
215 | return (struct nilfs_dir_entry *)((char *)p + |
216 | nilfs_rec_len_from_disk(p->rec_len)); | |
2ba466d7 YA |
217 | } |
218 | ||
219 | static unsigned char | |
220 | nilfs_filetype_table[NILFS_FT_MAX] = { | |
221 | [NILFS_FT_UNKNOWN] = DT_UNKNOWN, | |
222 | [NILFS_FT_REG_FILE] = DT_REG, | |
223 | [NILFS_FT_DIR] = DT_DIR, | |
224 | [NILFS_FT_CHRDEV] = DT_CHR, | |
225 | [NILFS_FT_BLKDEV] = DT_BLK, | |
226 | [NILFS_FT_FIFO] = DT_FIFO, | |
227 | [NILFS_FT_SOCK] = DT_SOCK, | |
228 | [NILFS_FT_SYMLINK] = DT_LNK, | |
229 | }; | |
230 | ||
231 | #define S_SHIFT 12 | |
232 | static unsigned char | |
233 | nilfs_type_by_mode[S_IFMT >> S_SHIFT] = { | |
234 | [S_IFREG >> S_SHIFT] = NILFS_FT_REG_FILE, | |
235 | [S_IFDIR >> S_SHIFT] = NILFS_FT_DIR, | |
236 | [S_IFCHR >> S_SHIFT] = NILFS_FT_CHRDEV, | |
237 | [S_IFBLK >> S_SHIFT] = NILFS_FT_BLKDEV, | |
238 | [S_IFIFO >> S_SHIFT] = NILFS_FT_FIFO, | |
239 | [S_IFSOCK >> S_SHIFT] = NILFS_FT_SOCK, | |
240 | [S_IFLNK >> S_SHIFT] = NILFS_FT_SYMLINK, | |
241 | }; | |
242 | ||
243 | static void nilfs_set_de_type(struct nilfs_dir_entry *de, struct inode *inode) | |
244 | { | |
c6e49e3f | 245 | umode_t mode = inode->i_mode; |
2ba466d7 YA |
246 | |
247 | de->file_type = nilfs_type_by_mode[(mode & S_IFMT)>>S_SHIFT]; | |
248 | } | |
249 | ||
1616abe8 | 250 | static int nilfs_readdir(struct file *file, struct dir_context *ctx) |
2ba466d7 | 251 | { |
1616abe8 AV |
252 | loff_t pos = ctx->pos; |
253 | struct inode *inode = file_inode(file); | |
2ba466d7 | 254 | struct super_block *sb = inode->i_sb; |
09cbfeaf KS |
255 | unsigned int offset = pos & ~PAGE_MASK; |
256 | unsigned long n = pos >> PAGE_SHIFT; | |
2ba466d7 | 257 | unsigned long npages = dir_pages(inode); |
2ba466d7 YA |
258 | |
259 | if (pos > inode->i_size - NILFS_DIR_REC_LEN(1)) | |
1616abe8 | 260 | return 0; |
2ba466d7 YA |
261 | |
262 | for ( ; n < npages; n++, offset = 0) { | |
263 | char *kaddr, *limit; | |
264 | struct nilfs_dir_entry *de; | |
265 | struct page *page = nilfs_get_page(inode, n); | |
266 | ||
267 | if (IS_ERR(page)) { | |
cae3d4ca | 268 | nilfs_error(sb, "bad page in #%lu", inode->i_ino); |
09cbfeaf | 269 | ctx->pos += PAGE_SIZE - offset; |
1616abe8 | 270 | return -EIO; |
2ba466d7 YA |
271 | } |
272 | kaddr = page_address(page); | |
273 | de = (struct nilfs_dir_entry *)(kaddr + offset); | |
274 | limit = kaddr + nilfs_last_byte(inode, n) - | |
275 | NILFS_DIR_REC_LEN(1); | |
276 | for ( ; (char *)de <= limit; de = nilfs_next_entry(de)) { | |
277 | if (de->rec_len == 0) { | |
cae3d4ca | 278 | nilfs_error(sb, "zero-length directory entry"); |
2ba466d7 | 279 | nilfs_put_page(page); |
1616abe8 | 280 | return -EIO; |
2ba466d7 YA |
281 | } |
282 | if (de->inode) { | |
1616abe8 | 283 | unsigned char t; |
2ba466d7 | 284 | |
1616abe8 AV |
285 | if (de->file_type < NILFS_FT_MAX) |
286 | t = nilfs_filetype_table[de->file_type]; | |
287 | else | |
288 | t = DT_UNKNOWN; | |
2ba466d7 | 289 | |
1616abe8 AV |
290 | if (!dir_emit(ctx, de->name, de->name_len, |
291 | le64_to_cpu(de->inode), t)) { | |
2ba466d7 | 292 | nilfs_put_page(page); |
1616abe8 | 293 | return 0; |
2ba466d7 YA |
294 | } |
295 | } | |
1616abe8 | 296 | ctx->pos += nilfs_rec_len_from_disk(de->rec_len); |
2ba466d7 YA |
297 | } |
298 | nilfs_put_page(page); | |
299 | } | |
1616abe8 | 300 | return 0; |
2ba466d7 YA |
301 | } |
302 | ||
303 | /* | |
304 | * nilfs_find_entry() | |
305 | * | |
306 | * finds an entry in the specified directory with the wanted name. It | |
307 | * returns the page in which the entry was found, and the entry itself | |
308 | * (as a parameter - res_dir). Page is returned mapped and unlocked. | |
309 | * Entry is guaranteed to be valid. | |
310 | */ | |
311 | struct nilfs_dir_entry * | |
0319003d | 312 | nilfs_find_entry(struct inode *dir, const struct qstr *qstr, |
2ba466d7 YA |
313 | struct page **res_page) |
314 | { | |
0319003d AV |
315 | const unsigned char *name = qstr->name; |
316 | int namelen = qstr->len; | |
0c6c44cb | 317 | unsigned int reclen = NILFS_DIR_REC_LEN(namelen); |
2ba466d7 YA |
318 | unsigned long start, n; |
319 | unsigned long npages = dir_pages(dir); | |
320 | struct page *page = NULL; | |
321 | struct nilfs_inode_info *ei = NILFS_I(dir); | |
322 | struct nilfs_dir_entry *de; | |
323 | ||
324 | if (npages == 0) | |
325 | goto out; | |
326 | ||
327 | /* OFFSET_CACHE */ | |
328 | *res_page = NULL; | |
329 | ||
330 | start = ei->i_dir_start_lookup; | |
331 | if (start >= npages) | |
332 | start = 0; | |
333 | n = start; | |
334 | do { | |
335 | char *kaddr; | |
4ad364ca | 336 | |
2ba466d7 YA |
337 | page = nilfs_get_page(dir, n); |
338 | if (!IS_ERR(page)) { | |
339 | kaddr = page_address(page); | |
340 | de = (struct nilfs_dir_entry *)kaddr; | |
341 | kaddr += nilfs_last_byte(dir, n) - reclen; | |
342 | while ((char *) de <= kaddr) { | |
343 | if (de->rec_len == 0) { | |
cae3d4ca | 344 | nilfs_error(dir->i_sb, |
2ba466d7 YA |
345 | "zero-length directory entry"); |
346 | nilfs_put_page(page); | |
347 | goto out; | |
348 | } | |
349 | if (nilfs_match(namelen, name, de)) | |
350 | goto found; | |
351 | de = nilfs_next_entry(de); | |
352 | } | |
353 | nilfs_put_page(page); | |
354 | } | |
355 | if (++n >= npages) | |
356 | n = 0; | |
357 | /* next page is past the blocks we've got */ | |
09cbfeaf | 358 | if (unlikely(n > (dir->i_blocks >> (PAGE_SHIFT - 9)))) { |
cae3d4ca | 359 | nilfs_error(dir->i_sb, |
1621562b | 360 | "dir %lu size %lld exceeds block count %llu", |
2ba466d7 YA |
361 | dir->i_ino, dir->i_size, |
362 | (unsigned long long)dir->i_blocks); | |
363 | goto out; | |
364 | } | |
365 | } while (n != start); | |
366 | out: | |
367 | return NULL; | |
368 | ||
369 | found: | |
370 | *res_page = page; | |
371 | ei->i_dir_start_lookup = n; | |
372 | return de; | |
373 | } | |
374 | ||
375 | struct nilfs_dir_entry *nilfs_dotdot(struct inode *dir, struct page **p) | |
376 | { | |
377 | struct page *page = nilfs_get_page(dir, 0); | |
378 | struct nilfs_dir_entry *de = NULL; | |
379 | ||
380 | if (!IS_ERR(page)) { | |
381 | de = nilfs_next_entry( | |
382 | (struct nilfs_dir_entry *)page_address(page)); | |
383 | *p = page; | |
384 | } | |
385 | return de; | |
386 | } | |
387 | ||
0319003d | 388 | ino_t nilfs_inode_by_name(struct inode *dir, const struct qstr *qstr) |
2ba466d7 YA |
389 | { |
390 | ino_t res = 0; | |
391 | struct nilfs_dir_entry *de; | |
392 | struct page *page; | |
393 | ||
0319003d | 394 | de = nilfs_find_entry(dir, qstr, &page); |
2ba466d7 YA |
395 | if (de) { |
396 | res = le64_to_cpu(de->inode); | |
397 | kunmap(page); | |
09cbfeaf | 398 | put_page(page); |
2ba466d7 YA |
399 | } |
400 | return res; | |
401 | } | |
402 | ||
403 | /* Releases the page */ | |
404 | void nilfs_set_link(struct inode *dir, struct nilfs_dir_entry *de, | |
405 | struct page *page, struct inode *inode) | |
406 | { | |
0c6c44cb RK |
407 | unsigned int from = (char *)de - (char *)page_address(page); |
408 | unsigned int to = from + nilfs_rec_len_from_disk(de->rec_len); | |
2ba466d7 YA |
409 | struct address_space *mapping = page->mapping; |
410 | int err; | |
411 | ||
412 | lock_page(page); | |
f4e420dc | 413 | err = nilfs_prepare_chunk(page, from, to); |
2ba466d7 YA |
414 | BUG_ON(err); |
415 | de->inode = cpu_to_le64(inode->i_ino); | |
416 | nilfs_set_de_type(de, inode); | |
2093abf9 | 417 | nilfs_commit_chunk(page, mapping, from, to); |
2ba466d7 YA |
418 | nilfs_put_page(page); |
419 | dir->i_mtime = dir->i_ctime = CURRENT_TIME; | |
2ba466d7 YA |
420 | } |
421 | ||
422 | /* | |
423 | * Parent is locked. | |
424 | */ | |
425 | int nilfs_add_link(struct dentry *dentry, struct inode *inode) | |
426 | { | |
2b0143b5 | 427 | struct inode *dir = d_inode(dentry->d_parent); |
072f98b4 | 428 | const unsigned char *name = dentry->d_name.name; |
2ba466d7 | 429 | int namelen = dentry->d_name.len; |
0c6c44cb RK |
430 | unsigned int chunk_size = nilfs_chunk_size(dir); |
431 | unsigned int reclen = NILFS_DIR_REC_LEN(namelen); | |
2ba466d7 YA |
432 | unsigned short rec_len, name_len; |
433 | struct page *page = NULL; | |
434 | struct nilfs_dir_entry *de; | |
435 | unsigned long npages = dir_pages(dir); | |
436 | unsigned long n; | |
437 | char *kaddr; | |
0c6c44cb | 438 | unsigned int from, to; |
2ba466d7 YA |
439 | int err; |
440 | ||
441 | /* | |
442 | * We take care of directory expansion in the same loop. | |
443 | * This code plays outside i_size, so it locks the page | |
444 | * to protect that region. | |
445 | */ | |
446 | for (n = 0; n <= npages; n++) { | |
447 | char *dir_end; | |
448 | ||
449 | page = nilfs_get_page(dir, n); | |
450 | err = PTR_ERR(page); | |
451 | if (IS_ERR(page)) | |
452 | goto out; | |
453 | lock_page(page); | |
454 | kaddr = page_address(page); | |
455 | dir_end = kaddr + nilfs_last_byte(dir, n); | |
456 | de = (struct nilfs_dir_entry *)kaddr; | |
09cbfeaf | 457 | kaddr += PAGE_SIZE - reclen; |
2ba466d7 YA |
458 | while ((char *)de <= kaddr) { |
459 | if ((char *)de == dir_end) { | |
460 | /* We hit i_size */ | |
461 | name_len = 0; | |
462 | rec_len = chunk_size; | |
6cda9fa2 | 463 | de->rec_len = nilfs_rec_len_to_disk(chunk_size); |
2ba466d7 YA |
464 | de->inode = 0; |
465 | goto got_it; | |
466 | } | |
467 | if (de->rec_len == 0) { | |
cae3d4ca | 468 | nilfs_error(dir->i_sb, |
2ba466d7 YA |
469 | "zero-length directory entry"); |
470 | err = -EIO; | |
471 | goto out_unlock; | |
472 | } | |
473 | err = -EEXIST; | |
474 | if (nilfs_match(namelen, name, de)) | |
475 | goto out_unlock; | |
476 | name_len = NILFS_DIR_REC_LEN(de->name_len); | |
6cda9fa2 | 477 | rec_len = nilfs_rec_len_from_disk(de->rec_len); |
2ba466d7 YA |
478 | if (!de->inode && rec_len >= reclen) |
479 | goto got_it; | |
480 | if (rec_len >= name_len + reclen) | |
481 | goto got_it; | |
482 | de = (struct nilfs_dir_entry *)((char *)de + rec_len); | |
483 | } | |
484 | unlock_page(page); | |
485 | nilfs_put_page(page); | |
486 | } | |
487 | BUG(); | |
488 | return -EINVAL; | |
489 | ||
490 | got_it: | |
491 | from = (char *)de - (char *)page_address(page); | |
492 | to = from + rec_len; | |
f4e420dc | 493 | err = nilfs_prepare_chunk(page, from, to); |
2ba466d7 YA |
494 | if (err) |
495 | goto out_unlock; | |
496 | if (de->inode) { | |
497 | struct nilfs_dir_entry *de1; | |
498 | ||
499 | de1 = (struct nilfs_dir_entry *)((char *)de + name_len); | |
6cda9fa2 RK |
500 | de1->rec_len = nilfs_rec_len_to_disk(rec_len - name_len); |
501 | de->rec_len = nilfs_rec_len_to_disk(name_len); | |
2ba466d7 YA |
502 | de = de1; |
503 | } | |
504 | de->name_len = namelen; | |
505 | memcpy(de->name, name, namelen); | |
506 | de->inode = cpu_to_le64(inode->i_ino); | |
507 | nilfs_set_de_type(de, inode); | |
2093abf9 | 508 | nilfs_commit_chunk(page, page->mapping, from, to); |
2ba466d7 | 509 | dir->i_mtime = dir->i_ctime = CURRENT_TIME; |
abdb318b | 510 | nilfs_mark_inode_dirty(dir); |
2ba466d7 YA |
511 | /* OFFSET_CACHE */ |
512 | out_put: | |
513 | nilfs_put_page(page); | |
514 | out: | |
515 | return err; | |
516 | out_unlock: | |
517 | unlock_page(page); | |
518 | goto out_put; | |
519 | } | |
520 | ||
521 | /* | |
522 | * nilfs_delete_entry deletes a directory entry by merging it with the | |
523 | * previous entry. Page is up-to-date. Releases the page. | |
524 | */ | |
525 | int nilfs_delete_entry(struct nilfs_dir_entry *dir, struct page *page) | |
526 | { | |
527 | struct address_space *mapping = page->mapping; | |
528 | struct inode *inode = mapping->host; | |
529 | char *kaddr = page_address(page); | |
0c6c44cb RK |
530 | unsigned int from, to; |
531 | struct nilfs_dir_entry *de, *pde = NULL; | |
2ba466d7 YA |
532 | int err; |
533 | ||
0c6c44cb RK |
534 | from = ((char *)dir - kaddr) & ~(nilfs_chunk_size(inode) - 1); |
535 | to = ((char *)dir - kaddr) + nilfs_rec_len_from_disk(dir->rec_len); | |
536 | de = (struct nilfs_dir_entry *)(kaddr + from); | |
537 | ||
2ba466d7 YA |
538 | while ((char *)de < (char *)dir) { |
539 | if (de->rec_len == 0) { | |
cae3d4ca | 540 | nilfs_error(inode->i_sb, |
2ba466d7 YA |
541 | "zero-length directory entry"); |
542 | err = -EIO; | |
543 | goto out; | |
544 | } | |
545 | pde = de; | |
546 | de = nilfs_next_entry(de); | |
547 | } | |
548 | if (pde) | |
549 | from = (char *)pde - (char *)page_address(page); | |
550 | lock_page(page); | |
f4e420dc | 551 | err = nilfs_prepare_chunk(page, from, to); |
2ba466d7 YA |
552 | BUG_ON(err); |
553 | if (pde) | |
6cda9fa2 | 554 | pde->rec_len = nilfs_rec_len_to_disk(to - from); |
2ba466d7 | 555 | dir->inode = 0; |
2093abf9 | 556 | nilfs_commit_chunk(page, mapping, from, to); |
2ba466d7 | 557 | inode->i_ctime = inode->i_mtime = CURRENT_TIME; |
2ba466d7 YA |
558 | out: |
559 | nilfs_put_page(page); | |
560 | return err; | |
561 | } | |
562 | ||
563 | /* | |
564 | * Set the first fragment of directory. | |
565 | */ | |
566 | int nilfs_make_empty(struct inode *inode, struct inode *parent) | |
567 | { | |
568 | struct address_space *mapping = inode->i_mapping; | |
569 | struct page *page = grab_cache_page(mapping, 0); | |
0c6c44cb | 570 | unsigned int chunk_size = nilfs_chunk_size(inode); |
2ba466d7 YA |
571 | struct nilfs_dir_entry *de; |
572 | int err; | |
573 | void *kaddr; | |
574 | ||
575 | if (!page) | |
576 | return -ENOMEM; | |
577 | ||
f4e420dc | 578 | err = nilfs_prepare_chunk(page, 0, chunk_size); |
2ba466d7 YA |
579 | if (unlikely(err)) { |
580 | unlock_page(page); | |
581 | goto fail; | |
582 | } | |
7b9c0976 | 583 | kaddr = kmap_atomic(page); |
2ba466d7 YA |
584 | memset(kaddr, 0, chunk_size); |
585 | de = (struct nilfs_dir_entry *)kaddr; | |
586 | de->name_len = 1; | |
6cda9fa2 | 587 | de->rec_len = nilfs_rec_len_to_disk(NILFS_DIR_REC_LEN(1)); |
2ba466d7 YA |
588 | memcpy(de->name, ".\0\0", 4); |
589 | de->inode = cpu_to_le64(inode->i_ino); | |
590 | nilfs_set_de_type(de, inode); | |
591 | ||
592 | de = (struct nilfs_dir_entry *)(kaddr + NILFS_DIR_REC_LEN(1)); | |
593 | de->name_len = 2; | |
6cda9fa2 | 594 | de->rec_len = nilfs_rec_len_to_disk(chunk_size - NILFS_DIR_REC_LEN(1)); |
2ba466d7 YA |
595 | de->inode = cpu_to_le64(parent->i_ino); |
596 | memcpy(de->name, "..\0", 4); | |
597 | nilfs_set_de_type(de, inode); | |
7b9c0976 | 598 | kunmap_atomic(kaddr); |
2093abf9 | 599 | nilfs_commit_chunk(page, mapping, 0, chunk_size); |
2ba466d7 | 600 | fail: |
09cbfeaf | 601 | put_page(page); |
2ba466d7 YA |
602 | return err; |
603 | } | |
604 | ||
605 | /* | |
606 | * routine to check that the specified directory is empty (for rmdir) | |
607 | */ | |
608 | int nilfs_empty_dir(struct inode *inode) | |
609 | { | |
610 | struct page *page = NULL; | |
611 | unsigned long i, npages = dir_pages(inode); | |
612 | ||
613 | for (i = 0; i < npages; i++) { | |
614 | char *kaddr; | |
615 | struct nilfs_dir_entry *de; | |
616 | ||
617 | page = nilfs_get_page(inode, i); | |
618 | if (IS_ERR(page)) | |
619 | continue; | |
620 | ||
621 | kaddr = page_address(page); | |
622 | de = (struct nilfs_dir_entry *)kaddr; | |
623 | kaddr += nilfs_last_byte(inode, i) - NILFS_DIR_REC_LEN(1); | |
624 | ||
625 | while ((char *)de <= kaddr) { | |
626 | if (de->rec_len == 0) { | |
cae3d4ca | 627 | nilfs_error(inode->i_sb, |
06f4abf6 RK |
628 | "zero-length directory entry (kaddr=%p, de=%p)", |
629 | kaddr, de); | |
2ba466d7 YA |
630 | goto not_empty; |
631 | } | |
632 | if (de->inode != 0) { | |
633 | /* check for . and .. */ | |
634 | if (de->name[0] != '.') | |
635 | goto not_empty; | |
636 | if (de->name_len > 2) | |
637 | goto not_empty; | |
638 | if (de->name_len < 2) { | |
639 | if (de->inode != | |
640 | cpu_to_le64(inode->i_ino)) | |
641 | goto not_empty; | |
642 | } else if (de->name[1] != '.') | |
643 | goto not_empty; | |
644 | } | |
645 | de = nilfs_next_entry(de); | |
646 | } | |
647 | nilfs_put_page(page); | |
648 | } | |
649 | return 1; | |
650 | ||
651 | not_empty: | |
652 | nilfs_put_page(page); | |
653 | return 0; | |
654 | } | |
655 | ||
828c0950 | 656 | const struct file_operations nilfs_dir_operations = { |
2ba466d7 YA |
657 | .llseek = generic_file_llseek, |
658 | .read = generic_read_dir, | |
c51da20c | 659 | .iterate_shared = nilfs_readdir, |
7a946193 | 660 | .unlocked_ioctl = nilfs_ioctl, |
2ba466d7 | 661 | #ifdef CONFIG_COMPAT |
828b1c50 | 662 | .compat_ioctl = nilfs_compat_ioctl, |
2ba466d7 YA |
663 | #endif /* CONFIG_COMPAT */ |
664 | .fsync = nilfs_sync_file, | |
665 | ||
666 | }; |