Root/
1 | /* |
2 | * Copyright (C) 2005, 2006 |
3 | * Avishay Traeger (avishay@gmail.com) |
4 | * Copyright (C) 2008, 2009 |
5 | * Boaz Harrosh <bharrosh@panasas.com> |
6 | * |
7 | * Copyrights for code taken from ext2: |
8 | * Copyright (C) 1992, 1993, 1994, 1995 |
9 | * Remy Card (card@masi.ibp.fr) |
10 | * Laboratoire MASI - Institut Blaise Pascal |
11 | * Universite Pierre et Marie Curie (Paris VI) |
12 | * from |
13 | * linux/fs/minix/inode.c |
14 | * Copyright (C) 1991, 1992 Linus Torvalds |
15 | * |
16 | * This file is part of exofs. |
17 | * |
18 | * exofs is free software; you can redistribute it and/or modify |
19 | * it under the terms of the GNU General Public License as published by |
20 | * the Free Software Foundation. Since it is based on ext2, and the only |
21 | * valid version of GPL for the Linux kernel is version 2, the only valid |
22 | * version of GPL for exofs is version 2. |
23 | * |
24 | * exofs is distributed in the hope that it will be useful, |
25 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
26 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
27 | * GNU General Public License for more details. |
28 | * |
29 | * You should have received a copy of the GNU General Public License |
30 | * along with exofs; if not, write to the Free Software |
31 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
32 | */ |
33 | |
34 | #include "exofs.h" |
35 | |
36 | static inline unsigned exofs_chunk_size(struct inode *inode) |
37 | { |
38 | return inode->i_sb->s_blocksize; |
39 | } |
40 | |
41 | static inline void exofs_put_page(struct page *page) |
42 | { |
43 | kunmap(page); |
44 | page_cache_release(page); |
45 | } |
46 | |
47 | /* Accesses dir's inode->i_size must be called under inode lock */ |
48 | static inline unsigned long dir_pages(struct inode *inode) |
49 | { |
50 | return (inode->i_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; |
51 | } |
52 | |
53 | static unsigned exofs_last_byte(struct inode *inode, unsigned long page_nr) |
54 | { |
55 | loff_t last_byte = inode->i_size; |
56 | |
57 | last_byte -= page_nr << PAGE_CACHE_SHIFT; |
58 | if (last_byte > PAGE_CACHE_SIZE) |
59 | last_byte = PAGE_CACHE_SIZE; |
60 | return last_byte; |
61 | } |
62 | |
63 | static int exofs_commit_chunk(struct page *page, loff_t pos, unsigned len) |
64 | { |
65 | struct address_space *mapping = page->mapping; |
66 | struct inode *dir = mapping->host; |
67 | int err = 0; |
68 | |
69 | dir->i_version++; |
70 | |
71 | if (!PageUptodate(page)) |
72 | SetPageUptodate(page); |
73 | |
74 | if (pos+len > dir->i_size) { |
75 | i_size_write(dir, pos+len); |
76 | mark_inode_dirty(dir); |
77 | } |
78 | set_page_dirty(page); |
79 | |
80 | if (IS_DIRSYNC(dir)) |
81 | err = write_one_page(page, 1); |
82 | else |
83 | unlock_page(page); |
84 | |
85 | return err; |
86 | } |
87 | |
88 | static void exofs_check_page(struct page *page) |
89 | { |
90 | struct inode *dir = page->mapping->host; |
91 | unsigned chunk_size = exofs_chunk_size(dir); |
92 | char *kaddr = page_address(page); |
93 | unsigned offs, rec_len; |
94 | unsigned limit = PAGE_CACHE_SIZE; |
95 | struct exofs_dir_entry *p; |
96 | char *error; |
97 | |
98 | /* if the page is the last one in the directory */ |
99 | if ((dir->i_size >> PAGE_CACHE_SHIFT) == page->index) { |
100 | limit = dir->i_size & ~PAGE_CACHE_MASK; |
101 | if (limit & (chunk_size - 1)) |
102 | goto Ebadsize; |
103 | if (!limit) |
104 | goto out; |
105 | } |
106 | for (offs = 0; offs <= limit - EXOFS_DIR_REC_LEN(1); offs += rec_len) { |
107 | p = (struct exofs_dir_entry *)(kaddr + offs); |
108 | rec_len = le16_to_cpu(p->rec_len); |
109 | |
110 | if (rec_len < EXOFS_DIR_REC_LEN(1)) |
111 | goto Eshort; |
112 | if (rec_len & 3) |
113 | goto Ealign; |
114 | if (rec_len < EXOFS_DIR_REC_LEN(p->name_len)) |
115 | goto Enamelen; |
116 | if (((offs + rec_len - 1) ^ offs) & ~(chunk_size-1)) |
117 | goto Espan; |
118 | } |
119 | if (offs != limit) |
120 | goto Eend; |
121 | out: |
122 | SetPageChecked(page); |
123 | return; |
124 | |
125 | Ebadsize: |
126 | EXOFS_ERR("ERROR [exofs_check_page]: " |
127 | "size of directory #%lu is not a multiple of chunk size", |
128 | dir->i_ino |
129 | ); |
130 | goto fail; |
131 | Eshort: |
132 | error = "rec_len is smaller than minimal"; |
133 | goto bad_entry; |
134 | Ealign: |
135 | error = "unaligned directory entry"; |
136 | goto bad_entry; |
137 | Enamelen: |
138 | error = "rec_len is too small for name_len"; |
139 | goto bad_entry; |
140 | Espan: |
141 | error = "directory entry across blocks"; |
142 | goto bad_entry; |
143 | bad_entry: |
144 | EXOFS_ERR( |
145 | "ERROR [exofs_check_page]: bad entry in directory #%lu: %s - " |
146 | "offset=%lu, inode=%llu, rec_len=%d, name_len=%d", |
147 | dir->i_ino, error, (page->index<<PAGE_CACHE_SHIFT)+offs, |
148 | _LLU(le64_to_cpu(p->inode_no)), |
149 | rec_len, p->name_len); |
150 | goto fail; |
151 | Eend: |
152 | p = (struct exofs_dir_entry *)(kaddr + offs); |
153 | EXOFS_ERR("ERROR [exofs_check_page]: " |
154 | "entry in directory #%lu spans the page boundary" |
155 | "offset=%lu, inode=%llu", |
156 | dir->i_ino, (page->index<<PAGE_CACHE_SHIFT)+offs, |
157 | _LLU(le64_to_cpu(p->inode_no))); |
158 | fail: |
159 | SetPageChecked(page); |
160 | SetPageError(page); |
161 | } |
162 | |
163 | static struct page *exofs_get_page(struct inode *dir, unsigned long n) |
164 | { |
165 | struct address_space *mapping = dir->i_mapping; |
166 | struct page *page = read_mapping_page(mapping, n, NULL); |
167 | |
168 | if (!IS_ERR(page)) { |
169 | kmap(page); |
170 | if (!PageChecked(page)) |
171 | exofs_check_page(page); |
172 | if (PageError(page)) |
173 | goto fail; |
174 | } |
175 | return page; |
176 | |
177 | fail: |
178 | exofs_put_page(page); |
179 | return ERR_PTR(-EIO); |
180 | } |
181 | |
182 | static inline int exofs_match(int len, const unsigned char *name, |
183 | struct exofs_dir_entry *de) |
184 | { |
185 | if (len != de->name_len) |
186 | return 0; |
187 | if (!de->inode_no) |
188 | return 0; |
189 | return !memcmp(name, de->name, len); |
190 | } |
191 | |
192 | static inline |
193 | struct exofs_dir_entry *exofs_next_entry(struct exofs_dir_entry *p) |
194 | { |
195 | return (struct exofs_dir_entry *)((char *)p + le16_to_cpu(p->rec_len)); |
196 | } |
197 | |
198 | static inline unsigned |
199 | exofs_validate_entry(char *base, unsigned offset, unsigned mask) |
200 | { |
201 | struct exofs_dir_entry *de = (struct exofs_dir_entry *)(base + offset); |
202 | struct exofs_dir_entry *p = |
203 | (struct exofs_dir_entry *)(base + (offset&mask)); |
204 | while ((char *)p < (char *)de) { |
205 | if (p->rec_len == 0) |
206 | break; |
207 | p = exofs_next_entry(p); |
208 | } |
209 | return (char *)p - base; |
210 | } |
211 | |
212 | static unsigned char exofs_filetype_table[EXOFS_FT_MAX] = { |
213 | [EXOFS_FT_UNKNOWN] = DT_UNKNOWN, |
214 | [EXOFS_FT_REG_FILE] = DT_REG, |
215 | [EXOFS_FT_DIR] = DT_DIR, |
216 | [EXOFS_FT_CHRDEV] = DT_CHR, |
217 | [EXOFS_FT_BLKDEV] = DT_BLK, |
218 | [EXOFS_FT_FIFO] = DT_FIFO, |
219 | [EXOFS_FT_SOCK] = DT_SOCK, |
220 | [EXOFS_FT_SYMLINK] = DT_LNK, |
221 | }; |
222 | |
223 | #define S_SHIFT 12 |
224 | static unsigned char exofs_type_by_mode[S_IFMT >> S_SHIFT] = { |
225 | [S_IFREG >> S_SHIFT] = EXOFS_FT_REG_FILE, |
226 | [S_IFDIR >> S_SHIFT] = EXOFS_FT_DIR, |
227 | [S_IFCHR >> S_SHIFT] = EXOFS_FT_CHRDEV, |
228 | [S_IFBLK >> S_SHIFT] = EXOFS_FT_BLKDEV, |
229 | [S_IFIFO >> S_SHIFT] = EXOFS_FT_FIFO, |
230 | [S_IFSOCK >> S_SHIFT] = EXOFS_FT_SOCK, |
231 | [S_IFLNK >> S_SHIFT] = EXOFS_FT_SYMLINK, |
232 | }; |
233 | |
234 | static inline |
235 | void exofs_set_de_type(struct exofs_dir_entry *de, struct inode *inode) |
236 | { |
237 | mode_t mode = inode->i_mode; |
238 | de->file_type = exofs_type_by_mode[(mode & S_IFMT) >> S_SHIFT]; |
239 | } |
240 | |
241 | static int |
242 | exofs_readdir(struct file *filp, void *dirent, filldir_t filldir) |
243 | { |
244 | loff_t pos = filp->f_pos; |
245 | struct inode *inode = filp->f_path.dentry->d_inode; |
246 | unsigned int offset = pos & ~PAGE_CACHE_MASK; |
247 | unsigned long n = pos >> PAGE_CACHE_SHIFT; |
248 | unsigned long npages = dir_pages(inode); |
249 | unsigned chunk_mask = ~(exofs_chunk_size(inode)-1); |
250 | unsigned char *types = NULL; |
251 | int need_revalidate = (filp->f_version != inode->i_version); |
252 | |
253 | if (pos > inode->i_size - EXOFS_DIR_REC_LEN(1)) |
254 | return 0; |
255 | |
256 | types = exofs_filetype_table; |
257 | |
258 | for ( ; n < npages; n++, offset = 0) { |
259 | char *kaddr, *limit; |
260 | struct exofs_dir_entry *de; |
261 | struct page *page = exofs_get_page(inode, n); |
262 | |
263 | if (IS_ERR(page)) { |
264 | EXOFS_ERR("ERROR: " |
265 | "bad page in #%lu", |
266 | inode->i_ino); |
267 | filp->f_pos += PAGE_CACHE_SIZE - offset; |
268 | return PTR_ERR(page); |
269 | } |
270 | kaddr = page_address(page); |
271 | if (unlikely(need_revalidate)) { |
272 | if (offset) { |
273 | offset = exofs_validate_entry(kaddr, offset, |
274 | chunk_mask); |
275 | filp->f_pos = (n<<PAGE_CACHE_SHIFT) + offset; |
276 | } |
277 | filp->f_version = inode->i_version; |
278 | need_revalidate = 0; |
279 | } |
280 | de = (struct exofs_dir_entry *)(kaddr + offset); |
281 | limit = kaddr + exofs_last_byte(inode, n) - |
282 | EXOFS_DIR_REC_LEN(1); |
283 | for (; (char *)de <= limit; de = exofs_next_entry(de)) { |
284 | if (de->rec_len == 0) { |
285 | EXOFS_ERR("ERROR: " |
286 | "zero-length directory entry"); |
287 | exofs_put_page(page); |
288 | return -EIO; |
289 | } |
290 | if (de->inode_no) { |
291 | int over; |
292 | unsigned char d_type = DT_UNKNOWN; |
293 | |
294 | if (types && de->file_type < EXOFS_FT_MAX) |
295 | d_type = types[de->file_type]; |
296 | |
297 | offset = (char *)de - kaddr; |
298 | over = filldir(dirent, de->name, de->name_len, |
299 | (n<<PAGE_CACHE_SHIFT) | offset, |
300 | le64_to_cpu(de->inode_no), |
301 | d_type); |
302 | if (over) { |
303 | exofs_put_page(page); |
304 | return 0; |
305 | } |
306 | } |
307 | filp->f_pos += le16_to_cpu(de->rec_len); |
308 | } |
309 | exofs_put_page(page); |
310 | } |
311 | |
312 | return 0; |
313 | } |
314 | |
315 | struct exofs_dir_entry *exofs_find_entry(struct inode *dir, |
316 | struct dentry *dentry, struct page **res_page) |
317 | { |
318 | const unsigned char *name = dentry->d_name.name; |
319 | int namelen = dentry->d_name.len; |
320 | unsigned reclen = EXOFS_DIR_REC_LEN(namelen); |
321 | unsigned long start, n; |
322 | unsigned long npages = dir_pages(dir); |
323 | struct page *page = NULL; |
324 | struct exofs_i_info *oi = exofs_i(dir); |
325 | struct exofs_dir_entry *de; |
326 | |
327 | if (npages == 0) |
328 | goto out; |
329 | |
330 | *res_page = NULL; |
331 | |
332 | start = oi->i_dir_start_lookup; |
333 | if (start >= npages) |
334 | start = 0; |
335 | n = start; |
336 | do { |
337 | char *kaddr; |
338 | page = exofs_get_page(dir, n); |
339 | if (!IS_ERR(page)) { |
340 | kaddr = page_address(page); |
341 | de = (struct exofs_dir_entry *) kaddr; |
342 | kaddr += exofs_last_byte(dir, n) - reclen; |
343 | while ((char *) de <= kaddr) { |
344 | if (de->rec_len == 0) { |
345 | EXOFS_ERR( |
346 | "ERROR: exofs_find_entry: " |
347 | "zero-length directory entry"); |
348 | exofs_put_page(page); |
349 | goto out; |
350 | } |
351 | if (exofs_match(namelen, name, de)) |
352 | goto found; |
353 | de = exofs_next_entry(de); |
354 | } |
355 | exofs_put_page(page); |
356 | } |
357 | if (++n >= npages) |
358 | n = 0; |
359 | } while (n != start); |
360 | out: |
361 | return NULL; |
362 | |
363 | found: |
364 | *res_page = page; |
365 | oi->i_dir_start_lookup = n; |
366 | return de; |
367 | } |
368 | |
369 | struct exofs_dir_entry *exofs_dotdot(struct inode *dir, struct page **p) |
370 | { |
371 | struct page *page = exofs_get_page(dir, 0); |
372 | struct exofs_dir_entry *de = NULL; |
373 | |
374 | if (!IS_ERR(page)) { |
375 | de = exofs_next_entry( |
376 | (struct exofs_dir_entry *)page_address(page)); |
377 | *p = page; |
378 | } |
379 | return de; |
380 | } |
381 | |
382 | ino_t exofs_parent_ino(struct dentry *child) |
383 | { |
384 | struct page *page; |
385 | struct exofs_dir_entry *de; |
386 | ino_t ino; |
387 | |
388 | de = exofs_dotdot(child->d_inode, &page); |
389 | if (!de) |
390 | return 0; |
391 | |
392 | ino = le64_to_cpu(de->inode_no); |
393 | exofs_put_page(page); |
394 | return ino; |
395 | } |
396 | |
397 | ino_t exofs_inode_by_name(struct inode *dir, struct dentry *dentry) |
398 | { |
399 | ino_t res = 0; |
400 | struct exofs_dir_entry *de; |
401 | struct page *page; |
402 | |
403 | de = exofs_find_entry(dir, dentry, &page); |
404 | if (de) { |
405 | res = le64_to_cpu(de->inode_no); |
406 | exofs_put_page(page); |
407 | } |
408 | return res; |
409 | } |
410 | |
411 | int exofs_set_link(struct inode *dir, struct exofs_dir_entry *de, |
412 | struct page *page, struct inode *inode) |
413 | { |
414 | loff_t pos = page_offset(page) + |
415 | (char *) de - (char *) page_address(page); |
416 | unsigned len = le16_to_cpu(de->rec_len); |
417 | int err; |
418 | |
419 | lock_page(page); |
420 | err = exofs_write_begin(NULL, page->mapping, pos, len, |
421 | AOP_FLAG_UNINTERRUPTIBLE, &page, NULL); |
422 | if (err) |
423 | EXOFS_ERR("exofs_set_link: exofs_write_begin FAILD => %d\n", |
424 | err); |
425 | |
426 | de->inode_no = cpu_to_le64(inode->i_ino); |
427 | exofs_set_de_type(de, inode); |
428 | if (likely(!err)) |
429 | err = exofs_commit_chunk(page, pos, len); |
430 | exofs_put_page(page); |
431 | dir->i_mtime = dir->i_ctime = CURRENT_TIME; |
432 | mark_inode_dirty(dir); |
433 | return err; |
434 | } |
435 | |
436 | int exofs_add_link(struct dentry *dentry, struct inode *inode) |
437 | { |
438 | struct inode *dir = dentry->d_parent->d_inode; |
439 | const unsigned char *name = dentry->d_name.name; |
440 | int namelen = dentry->d_name.len; |
441 | unsigned chunk_size = exofs_chunk_size(dir); |
442 | unsigned reclen = EXOFS_DIR_REC_LEN(namelen); |
443 | unsigned short rec_len, name_len; |
444 | struct page *page = NULL; |
445 | struct exofs_sb_info *sbi = inode->i_sb->s_fs_info; |
446 | struct exofs_dir_entry *de; |
447 | unsigned long npages = dir_pages(dir); |
448 | unsigned long n; |
449 | char *kaddr; |
450 | loff_t pos; |
451 | int err; |
452 | |
453 | for (n = 0; n <= npages; n++) { |
454 | char *dir_end; |
455 | |
456 | page = exofs_get_page(dir, n); |
457 | err = PTR_ERR(page); |
458 | if (IS_ERR(page)) |
459 | goto out; |
460 | lock_page(page); |
461 | kaddr = page_address(page); |
462 | dir_end = kaddr + exofs_last_byte(dir, n); |
463 | de = (struct exofs_dir_entry *)kaddr; |
464 | kaddr += PAGE_CACHE_SIZE - reclen; |
465 | while ((char *)de <= kaddr) { |
466 | if ((char *)de == dir_end) { |
467 | name_len = 0; |
468 | rec_len = chunk_size; |
469 | de->rec_len = cpu_to_le16(chunk_size); |
470 | de->inode_no = 0; |
471 | goto got_it; |
472 | } |
473 | if (de->rec_len == 0) { |
474 | EXOFS_ERR("ERROR: exofs_add_link: " |
475 | "zero-length directory entry"); |
476 | err = -EIO; |
477 | goto out_unlock; |
478 | } |
479 | err = -EEXIST; |
480 | if (exofs_match(namelen, name, de)) |
481 | goto out_unlock; |
482 | name_len = EXOFS_DIR_REC_LEN(de->name_len); |
483 | rec_len = le16_to_cpu(de->rec_len); |
484 | if (!de->inode_no && rec_len >= reclen) |
485 | goto got_it; |
486 | if (rec_len >= name_len + reclen) |
487 | goto got_it; |
488 | de = (struct exofs_dir_entry *) ((char *) de + rec_len); |
489 | } |
490 | unlock_page(page); |
491 | exofs_put_page(page); |
492 | } |
493 | |
494 | EXOFS_ERR("exofs_add_link: BAD dentry=%p or inode=%p", dentry, inode); |
495 | return -EINVAL; |
496 | |
497 | got_it: |
498 | pos = page_offset(page) + |
499 | (char *)de - (char *)page_address(page); |
500 | err = exofs_write_begin(NULL, page->mapping, pos, rec_len, 0, |
501 | &page, NULL); |
502 | if (err) |
503 | goto out_unlock; |
504 | if (de->inode_no) { |
505 | struct exofs_dir_entry *de1 = |
506 | (struct exofs_dir_entry *)((char *)de + name_len); |
507 | de1->rec_len = cpu_to_le16(rec_len - name_len); |
508 | de->rec_len = cpu_to_le16(name_len); |
509 | de = de1; |
510 | } |
511 | de->name_len = namelen; |
512 | memcpy(de->name, name, namelen); |
513 | de->inode_no = cpu_to_le64(inode->i_ino); |
514 | exofs_set_de_type(de, inode); |
515 | err = exofs_commit_chunk(page, pos, rec_len); |
516 | dir->i_mtime = dir->i_ctime = CURRENT_TIME; |
517 | mark_inode_dirty(dir); |
518 | sbi->s_numfiles++; |
519 | |
520 | out_put: |
521 | exofs_put_page(page); |
522 | out: |
523 | return err; |
524 | out_unlock: |
525 | unlock_page(page); |
526 | goto out_put; |
527 | } |
528 | |
529 | int exofs_delete_entry(struct exofs_dir_entry *dir, struct page *page) |
530 | { |
531 | struct address_space *mapping = page->mapping; |
532 | struct inode *inode = mapping->host; |
533 | struct exofs_sb_info *sbi = inode->i_sb->s_fs_info; |
534 | char *kaddr = page_address(page); |
535 | unsigned from = ((char *)dir - kaddr) & ~(exofs_chunk_size(inode)-1); |
536 | unsigned to = ((char *)dir - kaddr) + le16_to_cpu(dir->rec_len); |
537 | loff_t pos; |
538 | struct exofs_dir_entry *pde = NULL; |
539 | struct exofs_dir_entry *de = (struct exofs_dir_entry *) (kaddr + from); |
540 | int err; |
541 | |
542 | while (de < dir) { |
543 | if (de->rec_len == 0) { |
544 | EXOFS_ERR("ERROR: exofs_delete_entry:" |
545 | "zero-length directory entry"); |
546 | err = -EIO; |
547 | goto out; |
548 | } |
549 | pde = de; |
550 | de = exofs_next_entry(de); |
551 | } |
552 | if (pde) |
553 | from = (char *)pde - (char *)page_address(page); |
554 | pos = page_offset(page) + from; |
555 | lock_page(page); |
556 | err = exofs_write_begin(NULL, page->mapping, pos, to - from, 0, |
557 | &page, NULL); |
558 | if (err) |
559 | EXOFS_ERR("exofs_delete_entry: exofs_write_begin FAILD => %d\n", |
560 | err); |
561 | if (pde) |
562 | pde->rec_len = cpu_to_le16(to - from); |
563 | dir->inode_no = 0; |
564 | if (likely(!err)) |
565 | err = exofs_commit_chunk(page, pos, to - from); |
566 | inode->i_ctime = inode->i_mtime = CURRENT_TIME; |
567 | mark_inode_dirty(inode); |
568 | sbi->s_numfiles--; |
569 | out: |
570 | exofs_put_page(page); |
571 | return err; |
572 | } |
573 | |
574 | /* kept aligned on 4 bytes */ |
575 | #define THIS_DIR ".\0\0" |
576 | #define PARENT_DIR "..\0" |
577 | |
578 | int exofs_make_empty(struct inode *inode, struct inode *parent) |
579 | { |
580 | struct address_space *mapping = inode->i_mapping; |
581 | struct page *page = grab_cache_page(mapping, 0); |
582 | unsigned chunk_size = exofs_chunk_size(inode); |
583 | struct exofs_dir_entry *de; |
584 | int err; |
585 | void *kaddr; |
586 | |
587 | if (!page) |
588 | return -ENOMEM; |
589 | |
590 | err = exofs_write_begin(NULL, page->mapping, 0, chunk_size, 0, |
591 | &page, NULL); |
592 | if (err) { |
593 | unlock_page(page); |
594 | goto fail; |
595 | } |
596 | |
597 | kaddr = kmap_atomic(page, KM_USER0); |
598 | de = (struct exofs_dir_entry *)kaddr; |
599 | de->name_len = 1; |
600 | de->rec_len = cpu_to_le16(EXOFS_DIR_REC_LEN(1)); |
601 | memcpy(de->name, THIS_DIR, sizeof(THIS_DIR)); |
602 | de->inode_no = cpu_to_le64(inode->i_ino); |
603 | exofs_set_de_type(de, inode); |
604 | |
605 | de = (struct exofs_dir_entry *)(kaddr + EXOFS_DIR_REC_LEN(1)); |
606 | de->name_len = 2; |
607 | de->rec_len = cpu_to_le16(chunk_size - EXOFS_DIR_REC_LEN(1)); |
608 | de->inode_no = cpu_to_le64(parent->i_ino); |
609 | memcpy(de->name, PARENT_DIR, sizeof(PARENT_DIR)); |
610 | exofs_set_de_type(de, inode); |
611 | kunmap_atomic(page, KM_USER0); |
612 | err = exofs_commit_chunk(page, 0, chunk_size); |
613 | fail: |
614 | page_cache_release(page); |
615 | return err; |
616 | } |
617 | |
618 | int exofs_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 exofs_dir_entry *de; |
626 | page = exofs_get_page(inode, i); |
627 | |
628 | if (IS_ERR(page)) |
629 | continue; |
630 | |
631 | kaddr = page_address(page); |
632 | de = (struct exofs_dir_entry *)kaddr; |
633 | kaddr += exofs_last_byte(inode, i) - EXOFS_DIR_REC_LEN(1); |
634 | |
635 | while ((char *)de <= kaddr) { |
636 | if (de->rec_len == 0) { |
637 | EXOFS_ERR("ERROR: exofs_empty_dir: " |
638 | "zero-length directory entry" |
639 | "kaddr=%p, de=%p\n", kaddr, de); |
640 | goto not_empty; |
641 | } |
642 | if (de->inode_no != 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 (le64_to_cpu(de->inode_no) != |
650 | inode->i_ino) |
651 | goto not_empty; |
652 | } else if (de->name[1] != '.') |
653 | goto not_empty; |
654 | } |
655 | de = exofs_next_entry(de); |
656 | } |
657 | exofs_put_page(page); |
658 | } |
659 | return 1; |
660 | |
661 | not_empty: |
662 | exofs_put_page(page); |
663 | return 0; |
664 | } |
665 | |
666 | const struct file_operations exofs_dir_operations = { |
667 | .llseek = generic_file_llseek, |
668 | .read = generic_read_dir, |
669 | .readdir = exofs_readdir, |
670 | }; |
671 |
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Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9