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Commit | Line | Data |
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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: | |
143 | nilfs_error(sb, "nilfs_check_page", | |
144 | "size of directory #%lu is not a multiple of chunk size", | |
145 | dir->i_ino | |
146 | ); | |
147 | goto fail; | |
148 | Eshort: | |
149 | error = "rec_len is smaller than minimal"; | |
150 | goto bad_entry; | |
151 | Ealign: | |
152 | error = "unaligned directory entry"; | |
153 | goto bad_entry; | |
154 | Enamelen: | |
155 | error = "rec_len is too small for name_len"; | |
156 | goto bad_entry; | |
157 | Espan: | |
158 | error = "directory entry across blocks"; | |
159 | bad_entry: | |
160 | nilfs_error(sb, "nilfs_check_page", "bad entry in directory #%lu: %s - " | |
161 | "offset=%lu, inode=%lu, rec_len=%d, name_len=%d", | |
09cbfeaf | 162 | dir->i_ino, error, (page->index<<PAGE_SHIFT)+offs, |
2ba466d7 YA |
163 | (unsigned long) le64_to_cpu(p->inode), |
164 | rec_len, p->name_len); | |
165 | goto fail; | |
166 | Eend: | |
167 | p = (struct nilfs_dir_entry *)(kaddr + offs); | |
168 | nilfs_error(sb, "nilfs_check_page", | |
169 | "entry in directory #%lu spans the page boundary" | |
170 | "offset=%lu, inode=%lu", | |
09cbfeaf | 171 | dir->i_ino, (page->index<<PAGE_SHIFT)+offs, |
2ba466d7 YA |
172 | (unsigned long) le64_to_cpu(p->inode)); |
173 | fail: | |
2ba466d7 | 174 | SetPageError(page); |
be5b82db | 175 | return false; |
2ba466d7 YA |
176 | } |
177 | ||
178 | static struct page *nilfs_get_page(struct inode *dir, unsigned long n) | |
179 | { | |
180 | struct address_space *mapping = dir->i_mapping; | |
c28e69d9 RK |
181 | struct page *page = read_mapping_page(mapping, n, NULL); |
182 | ||
2ba466d7 | 183 | if (!IS_ERR(page)) { |
2ba466d7 | 184 | kmap(page); |
be5b82db AV |
185 | if (unlikely(!PageChecked(page))) { |
186 | if (PageError(page) || !nilfs_check_page(page)) | |
187 | goto fail; | |
188 | } | |
2ba466d7 YA |
189 | } |
190 | return page; | |
191 | ||
192 | fail: | |
193 | nilfs_put_page(page); | |
194 | return ERR_PTR(-EIO); | |
195 | } | |
196 | ||
197 | /* | |
198 | * NOTE! unlike strncmp, nilfs_match returns 1 for success, 0 for failure. | |
199 | * | |
200 | * len <= NILFS_NAME_LEN and de != NULL are guaranteed by caller. | |
201 | */ | |
202 | static int | |
072f98b4 | 203 | nilfs_match(int len, const unsigned char *name, struct nilfs_dir_entry *de) |
2ba466d7 YA |
204 | { |
205 | if (len != de->name_len) | |
206 | return 0; | |
207 | if (!de->inode) | |
208 | return 0; | |
209 | return !memcmp(name, de->name, len); | |
210 | } | |
211 | ||
212 | /* | |
213 | * p is at least 6 bytes before the end of page | |
214 | */ | |
215 | static struct nilfs_dir_entry *nilfs_next_entry(struct nilfs_dir_entry *p) | |
216 | { | |
6cda9fa2 RK |
217 | return (struct nilfs_dir_entry *)((char *)p + |
218 | nilfs_rec_len_from_disk(p->rec_len)); | |
2ba466d7 YA |
219 | } |
220 | ||
221 | static unsigned char | |
222 | nilfs_filetype_table[NILFS_FT_MAX] = { | |
223 | [NILFS_FT_UNKNOWN] = DT_UNKNOWN, | |
224 | [NILFS_FT_REG_FILE] = DT_REG, | |
225 | [NILFS_FT_DIR] = DT_DIR, | |
226 | [NILFS_FT_CHRDEV] = DT_CHR, | |
227 | [NILFS_FT_BLKDEV] = DT_BLK, | |
228 | [NILFS_FT_FIFO] = DT_FIFO, | |
229 | [NILFS_FT_SOCK] = DT_SOCK, | |
230 | [NILFS_FT_SYMLINK] = DT_LNK, | |
231 | }; | |
232 | ||
233 | #define S_SHIFT 12 | |
234 | static unsigned char | |
235 | nilfs_type_by_mode[S_IFMT >> S_SHIFT] = { | |
236 | [S_IFREG >> S_SHIFT] = NILFS_FT_REG_FILE, | |
237 | [S_IFDIR >> S_SHIFT] = NILFS_FT_DIR, | |
238 | [S_IFCHR >> S_SHIFT] = NILFS_FT_CHRDEV, | |
239 | [S_IFBLK >> S_SHIFT] = NILFS_FT_BLKDEV, | |
240 | [S_IFIFO >> S_SHIFT] = NILFS_FT_FIFO, | |
241 | [S_IFSOCK >> S_SHIFT] = NILFS_FT_SOCK, | |
242 | [S_IFLNK >> S_SHIFT] = NILFS_FT_SYMLINK, | |
243 | }; | |
244 | ||
245 | static void nilfs_set_de_type(struct nilfs_dir_entry *de, struct inode *inode) | |
246 | { | |
c6e49e3f | 247 | umode_t mode = inode->i_mode; |
2ba466d7 YA |
248 | |
249 | de->file_type = nilfs_type_by_mode[(mode & S_IFMT)>>S_SHIFT]; | |
250 | } | |
251 | ||
1616abe8 | 252 | static int nilfs_readdir(struct file *file, struct dir_context *ctx) |
2ba466d7 | 253 | { |
1616abe8 AV |
254 | loff_t pos = ctx->pos; |
255 | struct inode *inode = file_inode(file); | |
2ba466d7 | 256 | struct super_block *sb = inode->i_sb; |
09cbfeaf KS |
257 | unsigned int offset = pos & ~PAGE_MASK; |
258 | unsigned long n = pos >> PAGE_SHIFT; | |
2ba466d7 | 259 | unsigned long npages = dir_pages(inode); |
2ba466d7 YA |
260 | |
261 | if (pos > inode->i_size - NILFS_DIR_REC_LEN(1)) | |
1616abe8 | 262 | return 0; |
2ba466d7 YA |
263 | |
264 | for ( ; n < npages; n++, offset = 0) { | |
265 | char *kaddr, *limit; | |
266 | struct nilfs_dir_entry *de; | |
267 | struct page *page = nilfs_get_page(inode, n); | |
268 | ||
269 | if (IS_ERR(page)) { | |
270 | nilfs_error(sb, __func__, "bad page in #%lu", | |
271 | inode->i_ino); | |
09cbfeaf | 272 | ctx->pos += PAGE_SIZE - offset; |
1616abe8 | 273 | return -EIO; |
2ba466d7 YA |
274 | } |
275 | kaddr = page_address(page); | |
276 | de = (struct nilfs_dir_entry *)(kaddr + offset); | |
277 | limit = kaddr + nilfs_last_byte(inode, n) - | |
278 | NILFS_DIR_REC_LEN(1); | |
279 | for ( ; (char *)de <= limit; de = nilfs_next_entry(de)) { | |
280 | if (de->rec_len == 0) { | |
281 | nilfs_error(sb, __func__, | |
282 | "zero-length directory entry"); | |
2ba466d7 | 283 | nilfs_put_page(page); |
1616abe8 | 284 | return -EIO; |
2ba466d7 YA |
285 | } |
286 | if (de->inode) { | |
1616abe8 | 287 | unsigned char t; |
2ba466d7 | 288 | |
1616abe8 AV |
289 | if (de->file_type < NILFS_FT_MAX) |
290 | t = nilfs_filetype_table[de->file_type]; | |
291 | else | |
292 | t = DT_UNKNOWN; | |
2ba466d7 | 293 | |
1616abe8 AV |
294 | if (!dir_emit(ctx, de->name, de->name_len, |
295 | le64_to_cpu(de->inode), t)) { | |
2ba466d7 | 296 | nilfs_put_page(page); |
1616abe8 | 297 | return 0; |
2ba466d7 YA |
298 | } |
299 | } | |
1616abe8 | 300 | ctx->pos += nilfs_rec_len_from_disk(de->rec_len); |
2ba466d7 YA |
301 | } |
302 | nilfs_put_page(page); | |
303 | } | |
1616abe8 | 304 | return 0; |
2ba466d7 YA |
305 | } |
306 | ||
307 | /* | |
308 | * nilfs_find_entry() | |
309 | * | |
310 | * finds an entry in the specified directory with the wanted name. It | |
311 | * returns the page in which the entry was found, and the entry itself | |
312 | * (as a parameter - res_dir). Page is returned mapped and unlocked. | |
313 | * Entry is guaranteed to be valid. | |
314 | */ | |
315 | struct nilfs_dir_entry * | |
0319003d | 316 | nilfs_find_entry(struct inode *dir, const struct qstr *qstr, |
2ba466d7 YA |
317 | struct page **res_page) |
318 | { | |
0319003d AV |
319 | const unsigned char *name = qstr->name; |
320 | int namelen = qstr->len; | |
0c6c44cb | 321 | unsigned int reclen = NILFS_DIR_REC_LEN(namelen); |
2ba466d7 YA |
322 | unsigned long start, n; |
323 | unsigned long npages = dir_pages(dir); | |
324 | struct page *page = NULL; | |
325 | struct nilfs_inode_info *ei = NILFS_I(dir); | |
326 | struct nilfs_dir_entry *de; | |
327 | ||
328 | if (npages == 0) | |
329 | goto out; | |
330 | ||
331 | /* OFFSET_CACHE */ | |
332 | *res_page = NULL; | |
333 | ||
334 | start = ei->i_dir_start_lookup; | |
335 | if (start >= npages) | |
336 | start = 0; | |
337 | n = start; | |
338 | do { | |
339 | char *kaddr; | |
4ad364ca | 340 | |
2ba466d7 YA |
341 | page = nilfs_get_page(dir, n); |
342 | if (!IS_ERR(page)) { | |
343 | kaddr = page_address(page); | |
344 | de = (struct nilfs_dir_entry *)kaddr; | |
345 | kaddr += nilfs_last_byte(dir, n) - reclen; | |
346 | while ((char *) de <= kaddr) { | |
347 | if (de->rec_len == 0) { | |
348 | nilfs_error(dir->i_sb, __func__, | |
349 | "zero-length directory entry"); | |
350 | nilfs_put_page(page); | |
351 | goto out; | |
352 | } | |
353 | if (nilfs_match(namelen, name, de)) | |
354 | goto found; | |
355 | de = nilfs_next_entry(de); | |
356 | } | |
357 | nilfs_put_page(page); | |
358 | } | |
359 | if (++n >= npages) | |
360 | n = 0; | |
361 | /* next page is past the blocks we've got */ | |
09cbfeaf | 362 | if (unlikely(n > (dir->i_blocks >> (PAGE_SHIFT - 9)))) { |
2ba466d7 | 363 | nilfs_error(dir->i_sb, __func__, |
1621562b | 364 | "dir %lu size %lld exceeds block count %llu", |
2ba466d7 YA |
365 | dir->i_ino, dir->i_size, |
366 | (unsigned long long)dir->i_blocks); | |
367 | goto out; | |
368 | } | |
369 | } while (n != start); | |
370 | out: | |
371 | return NULL; | |
372 | ||
373 | found: | |
374 | *res_page = page; | |
375 | ei->i_dir_start_lookup = n; | |
376 | return de; | |
377 | } | |
378 | ||
379 | struct nilfs_dir_entry *nilfs_dotdot(struct inode *dir, struct page **p) | |
380 | { | |
381 | struct page *page = nilfs_get_page(dir, 0); | |
382 | struct nilfs_dir_entry *de = NULL; | |
383 | ||
384 | if (!IS_ERR(page)) { | |
385 | de = nilfs_next_entry( | |
386 | (struct nilfs_dir_entry *)page_address(page)); | |
387 | *p = page; | |
388 | } | |
389 | return de; | |
390 | } | |
391 | ||
0319003d | 392 | ino_t nilfs_inode_by_name(struct inode *dir, const struct qstr *qstr) |
2ba466d7 YA |
393 | { |
394 | ino_t res = 0; | |
395 | struct nilfs_dir_entry *de; | |
396 | struct page *page; | |
397 | ||
0319003d | 398 | de = nilfs_find_entry(dir, qstr, &page); |
2ba466d7 YA |
399 | if (de) { |
400 | res = le64_to_cpu(de->inode); | |
401 | kunmap(page); | |
09cbfeaf | 402 | put_page(page); |
2ba466d7 YA |
403 | } |
404 | return res; | |
405 | } | |
406 | ||
407 | /* Releases the page */ | |
408 | void nilfs_set_link(struct inode *dir, struct nilfs_dir_entry *de, | |
409 | struct page *page, struct inode *inode) | |
410 | { | |
0c6c44cb RK |
411 | unsigned int from = (char *)de - (char *)page_address(page); |
412 | unsigned int to = from + nilfs_rec_len_from_disk(de->rec_len); | |
2ba466d7 YA |
413 | struct address_space *mapping = page->mapping; |
414 | int err; | |
415 | ||
416 | lock_page(page); | |
f4e420dc | 417 | err = nilfs_prepare_chunk(page, from, to); |
2ba466d7 YA |
418 | BUG_ON(err); |
419 | de->inode = cpu_to_le64(inode->i_ino); | |
420 | nilfs_set_de_type(de, inode); | |
2093abf9 | 421 | nilfs_commit_chunk(page, mapping, from, to); |
2ba466d7 YA |
422 | nilfs_put_page(page); |
423 | dir->i_mtime = dir->i_ctime = CURRENT_TIME; | |
2ba466d7 YA |
424 | } |
425 | ||
426 | /* | |
427 | * Parent is locked. | |
428 | */ | |
429 | int nilfs_add_link(struct dentry *dentry, struct inode *inode) | |
430 | { | |
2b0143b5 | 431 | struct inode *dir = d_inode(dentry->d_parent); |
072f98b4 | 432 | const unsigned char *name = dentry->d_name.name; |
2ba466d7 | 433 | int namelen = dentry->d_name.len; |
0c6c44cb RK |
434 | unsigned int chunk_size = nilfs_chunk_size(dir); |
435 | unsigned int reclen = NILFS_DIR_REC_LEN(namelen); | |
2ba466d7 YA |
436 | unsigned short rec_len, name_len; |
437 | struct page *page = NULL; | |
438 | struct nilfs_dir_entry *de; | |
439 | unsigned long npages = dir_pages(dir); | |
440 | unsigned long n; | |
441 | char *kaddr; | |
0c6c44cb | 442 | unsigned int from, to; |
2ba466d7 YA |
443 | int err; |
444 | ||
445 | /* | |
446 | * We take care of directory expansion in the same loop. | |
447 | * This code plays outside i_size, so it locks the page | |
448 | * to protect that region. | |
449 | */ | |
450 | for (n = 0; n <= npages; n++) { | |
451 | char *dir_end; | |
452 | ||
453 | page = nilfs_get_page(dir, n); | |
454 | err = PTR_ERR(page); | |
455 | if (IS_ERR(page)) | |
456 | goto out; | |
457 | lock_page(page); | |
458 | kaddr = page_address(page); | |
459 | dir_end = kaddr + nilfs_last_byte(dir, n); | |
460 | de = (struct nilfs_dir_entry *)kaddr; | |
09cbfeaf | 461 | kaddr += PAGE_SIZE - reclen; |
2ba466d7 YA |
462 | while ((char *)de <= kaddr) { |
463 | if ((char *)de == dir_end) { | |
464 | /* We hit i_size */ | |
465 | name_len = 0; | |
466 | rec_len = chunk_size; | |
6cda9fa2 | 467 | de->rec_len = nilfs_rec_len_to_disk(chunk_size); |
2ba466d7 YA |
468 | de->inode = 0; |
469 | goto got_it; | |
470 | } | |
471 | if (de->rec_len == 0) { | |
472 | nilfs_error(dir->i_sb, __func__, | |
473 | "zero-length directory entry"); | |
474 | err = -EIO; | |
475 | goto out_unlock; | |
476 | } | |
477 | err = -EEXIST; | |
478 | if (nilfs_match(namelen, name, de)) | |
479 | goto out_unlock; | |
480 | name_len = NILFS_DIR_REC_LEN(de->name_len); | |
6cda9fa2 | 481 | rec_len = nilfs_rec_len_from_disk(de->rec_len); |
2ba466d7 YA |
482 | if (!de->inode && rec_len >= reclen) |
483 | goto got_it; | |
484 | if (rec_len >= name_len + reclen) | |
485 | goto got_it; | |
486 | de = (struct nilfs_dir_entry *)((char *)de + rec_len); | |
487 | } | |
488 | unlock_page(page); | |
489 | nilfs_put_page(page); | |
490 | } | |
491 | BUG(); | |
492 | return -EINVAL; | |
493 | ||
494 | got_it: | |
495 | from = (char *)de - (char *)page_address(page); | |
496 | to = from + rec_len; | |
f4e420dc | 497 | err = nilfs_prepare_chunk(page, from, to); |
2ba466d7 YA |
498 | if (err) |
499 | goto out_unlock; | |
500 | if (de->inode) { | |
501 | struct nilfs_dir_entry *de1; | |
502 | ||
503 | de1 = (struct nilfs_dir_entry *)((char *)de + name_len); | |
6cda9fa2 RK |
504 | de1->rec_len = nilfs_rec_len_to_disk(rec_len - name_len); |
505 | de->rec_len = nilfs_rec_len_to_disk(name_len); | |
2ba466d7 YA |
506 | de = de1; |
507 | } | |
508 | de->name_len = namelen; | |
509 | memcpy(de->name, name, namelen); | |
510 | de->inode = cpu_to_le64(inode->i_ino); | |
511 | nilfs_set_de_type(de, inode); | |
2093abf9 | 512 | nilfs_commit_chunk(page, page->mapping, from, to); |
2ba466d7 | 513 | dir->i_mtime = dir->i_ctime = CURRENT_TIME; |
abdb318b | 514 | nilfs_mark_inode_dirty(dir); |
2ba466d7 YA |
515 | /* OFFSET_CACHE */ |
516 | out_put: | |
517 | nilfs_put_page(page); | |
518 | out: | |
519 | return err; | |
520 | out_unlock: | |
521 | unlock_page(page); | |
522 | goto out_put; | |
523 | } | |
524 | ||
525 | /* | |
526 | * nilfs_delete_entry deletes a directory entry by merging it with the | |
527 | * previous entry. Page is up-to-date. Releases the page. | |
528 | */ | |
529 | int nilfs_delete_entry(struct nilfs_dir_entry *dir, struct page *page) | |
530 | { | |
531 | struct address_space *mapping = page->mapping; | |
532 | struct inode *inode = mapping->host; | |
533 | char *kaddr = page_address(page); | |
0c6c44cb RK |
534 | unsigned int from, to; |
535 | struct nilfs_dir_entry *de, *pde = NULL; | |
2ba466d7 YA |
536 | int err; |
537 | ||
0c6c44cb RK |
538 | from = ((char *)dir - kaddr) & ~(nilfs_chunk_size(inode) - 1); |
539 | to = ((char *)dir - kaddr) + nilfs_rec_len_from_disk(dir->rec_len); | |
540 | de = (struct nilfs_dir_entry *)(kaddr + from); | |
541 | ||
2ba466d7 YA |
542 | while ((char *)de < (char *)dir) { |
543 | if (de->rec_len == 0) { | |
544 | nilfs_error(inode->i_sb, __func__, | |
545 | "zero-length directory entry"); | |
546 | err = -EIO; | |
547 | goto out; | |
548 | } | |
549 | pde = de; | |
550 | de = nilfs_next_entry(de); | |
551 | } | |
552 | if (pde) | |
553 | from = (char *)pde - (char *)page_address(page); | |
554 | lock_page(page); | |
f4e420dc | 555 | err = nilfs_prepare_chunk(page, from, to); |
2ba466d7 YA |
556 | BUG_ON(err); |
557 | if (pde) | |
6cda9fa2 | 558 | pde->rec_len = nilfs_rec_len_to_disk(to - from); |
2ba466d7 | 559 | dir->inode = 0; |
2093abf9 | 560 | nilfs_commit_chunk(page, mapping, from, to); |
2ba466d7 | 561 | inode->i_ctime = inode->i_mtime = CURRENT_TIME; |
2ba466d7 YA |
562 | out: |
563 | nilfs_put_page(page); | |
564 | return err; | |
565 | } | |
566 | ||
567 | /* | |
568 | * Set the first fragment of directory. | |
569 | */ | |
570 | int nilfs_make_empty(struct inode *inode, struct inode *parent) | |
571 | { | |
572 | struct address_space *mapping = inode->i_mapping; | |
573 | struct page *page = grab_cache_page(mapping, 0); | |
0c6c44cb | 574 | unsigned int chunk_size = nilfs_chunk_size(inode); |
2ba466d7 YA |
575 | struct nilfs_dir_entry *de; |
576 | int err; | |
577 | void *kaddr; | |
578 | ||
579 | if (!page) | |
580 | return -ENOMEM; | |
581 | ||
f4e420dc | 582 | err = nilfs_prepare_chunk(page, 0, chunk_size); |
2ba466d7 YA |
583 | if (unlikely(err)) { |
584 | unlock_page(page); | |
585 | goto fail; | |
586 | } | |
7b9c0976 | 587 | kaddr = kmap_atomic(page); |
2ba466d7 YA |
588 | memset(kaddr, 0, chunk_size); |
589 | de = (struct nilfs_dir_entry *)kaddr; | |
590 | de->name_len = 1; | |
6cda9fa2 | 591 | de->rec_len = nilfs_rec_len_to_disk(NILFS_DIR_REC_LEN(1)); |
2ba466d7 YA |
592 | memcpy(de->name, ".\0\0", 4); |
593 | de->inode = cpu_to_le64(inode->i_ino); | |
594 | nilfs_set_de_type(de, inode); | |
595 | ||
596 | de = (struct nilfs_dir_entry *)(kaddr + NILFS_DIR_REC_LEN(1)); | |
597 | de->name_len = 2; | |
6cda9fa2 | 598 | de->rec_len = nilfs_rec_len_to_disk(chunk_size - NILFS_DIR_REC_LEN(1)); |
2ba466d7 YA |
599 | de->inode = cpu_to_le64(parent->i_ino); |
600 | memcpy(de->name, "..\0", 4); | |
601 | nilfs_set_de_type(de, inode); | |
7b9c0976 | 602 | kunmap_atomic(kaddr); |
2093abf9 | 603 | nilfs_commit_chunk(page, mapping, 0, chunk_size); |
2ba466d7 | 604 | fail: |
09cbfeaf | 605 | put_page(page); |
2ba466d7 YA |
606 | return err; |
607 | } | |
608 | ||
609 | /* | |
610 | * routine to check that the specified directory is empty (for rmdir) | |
611 | */ | |
612 | int nilfs_empty_dir(struct inode *inode) | |
613 | { | |
614 | struct page *page = NULL; | |
615 | unsigned long i, npages = dir_pages(inode); | |
616 | ||
617 | for (i = 0; i < npages; i++) { | |
618 | char *kaddr; | |
619 | struct nilfs_dir_entry *de; | |
620 | ||
621 | page = nilfs_get_page(inode, i); | |
622 | if (IS_ERR(page)) | |
623 | continue; | |
624 | ||
625 | kaddr = page_address(page); | |
626 | de = (struct nilfs_dir_entry *)kaddr; | |
627 | kaddr += nilfs_last_byte(inode, i) - NILFS_DIR_REC_LEN(1); | |
628 | ||
629 | while ((char *)de <= kaddr) { | |
630 | if (de->rec_len == 0) { | |
631 | nilfs_error(inode->i_sb, __func__, | |
06f4abf6 RK |
632 | "zero-length directory entry (kaddr=%p, de=%p)", |
633 | kaddr, de); | |
2ba466d7 YA |
634 | goto not_empty; |
635 | } | |
636 | if (de->inode != 0) { | |
637 | /* check for . and .. */ | |
638 | if (de->name[0] != '.') | |
639 | goto not_empty; | |
640 | if (de->name_len > 2) | |
641 | goto not_empty; | |
642 | if (de->name_len < 2) { | |
643 | if (de->inode != | |
644 | cpu_to_le64(inode->i_ino)) | |
645 | goto not_empty; | |
646 | } else if (de->name[1] != '.') | |
647 | goto not_empty; | |
648 | } | |
649 | de = nilfs_next_entry(de); | |
650 | } | |
651 | nilfs_put_page(page); | |
652 | } | |
653 | return 1; | |
654 | ||
655 | not_empty: | |
656 | nilfs_put_page(page); | |
657 | return 0; | |
658 | } | |
659 | ||
828c0950 | 660 | const struct file_operations nilfs_dir_operations = { |
2ba466d7 YA |
661 | .llseek = generic_file_llseek, |
662 | .read = generic_read_dir, | |
c51da20c | 663 | .iterate_shared = nilfs_readdir, |
7a946193 | 664 | .unlocked_ioctl = nilfs_ioctl, |
2ba466d7 | 665 | #ifdef CONFIG_COMPAT |
828b1c50 | 666 | .compat_ioctl = nilfs_compat_ioctl, |
2ba466d7 YA |
667 | #endif /* CONFIG_COMPAT */ |
668 | .fsync = nilfs_sync_file, | |
669 | ||
670 | }; |