Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/fs/ext2/dir.c | |
3 | * | |
4 | * Copyright (C) 1992, 1993, 1994, 1995 | |
5 | * Remy Card (card@masi.ibp.fr) | |
6 | * Laboratoire MASI - Institut Blaise Pascal | |
7 | * Universite Pierre et Marie Curie (Paris VI) | |
8 | * | |
9 | * from | |
10 | * | |
11 | * linux/fs/minix/dir.c | |
12 | * | |
13 | * Copyright (C) 1991, 1992 Linus Torvalds | |
14 | * | |
15 | * ext2 directory handling functions | |
16 | * | |
17 | * Big-endian to little-endian byte-swapping/bitmaps by | |
18 | * David S. Miller (davem@caip.rutgers.edu), 1995 | |
19 | * | |
20 | * All code that works with directory layout had been switched to pagecache | |
21 | * and moved here. AV | |
22 | */ | |
23 | ||
24 | #include "ext2.h" | |
f34fb6ec | 25 | #include <linux/buffer_head.h> |
1da177e4 | 26 | #include <linux/pagemap.h> |
f34fb6ec | 27 | #include <linux/swap.h> |
1da177e4 LT |
28 | |
29 | typedef struct ext2_dir_entry_2 ext2_dirent; | |
30 | ||
89910ccc JK |
31 | static inline unsigned ext2_rec_len_from_disk(__le16 dlen) |
32 | { | |
33 | unsigned len = le16_to_cpu(dlen); | |
34 | ||
35 | if (len == EXT2_MAX_REC_LEN) | |
36 | return 1 << 16; | |
37 | return len; | |
38 | } | |
39 | ||
40 | static inline __le16 ext2_rec_len_to_disk(unsigned len) | |
41 | { | |
42 | if (len == (1 << 16)) | |
43 | return cpu_to_le16(EXT2_MAX_REC_LEN); | |
44 | else if (len > (1 << 16)) | |
45 | BUG(); | |
46 | return cpu_to_le16(len); | |
47 | } | |
48 | ||
1da177e4 LT |
49 | /* |
50 | * ext2 uses block-sized chunks. Arguably, sector-sized ones would be | |
51 | * more robust, but we have what we have | |
52 | */ | |
53 | static inline unsigned ext2_chunk_size(struct inode *inode) | |
54 | { | |
55 | return inode->i_sb->s_blocksize; | |
56 | } | |
57 | ||
58 | static inline void ext2_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 | |
74 | ext2_last_byte(struct inode *inode, unsigned long page_nr) | |
75 | { | |
76 | unsigned last_byte = inode->i_size; | |
77 | ||
78 | last_byte -= page_nr << PAGE_CACHE_SHIFT; | |
79 | if (last_byte > PAGE_CACHE_SIZE) | |
80 | last_byte = PAGE_CACHE_SIZE; | |
81 | return last_byte; | |
82 | } | |
83 | ||
f34fb6ec | 84 | static int ext2_commit_chunk(struct page *page, loff_t pos, unsigned len) |
1da177e4 | 85 | { |
f34fb6ec NP |
86 | struct address_space *mapping = page->mapping; |
87 | struct inode *dir = mapping->host; | |
1da177e4 | 88 | int err = 0; |
f34fb6ec | 89 | |
1da177e4 | 90 | dir->i_version++; |
f34fb6ec NP |
91 | block_write_end(NULL, mapping, pos, len, len, page, NULL); |
92 | ||
93 | if (pos+len > dir->i_size) { | |
94 | i_size_write(dir, pos+len); | |
95 | mark_inode_dirty(dir); | |
96 | } | |
97 | ||
1da177e4 LT |
98 | if (IS_DIRSYNC(dir)) |
99 | err = write_one_page(page, 1); | |
100 | else | |
101 | unlock_page(page); | |
f34fb6ec | 102 | |
1da177e4 LT |
103 | return err; |
104 | } | |
105 | ||
106 | static void ext2_check_page(struct page *page) | |
107 | { | |
108 | struct inode *dir = page->mapping->host; | |
109 | struct super_block *sb = dir->i_sb; | |
110 | unsigned chunk_size = ext2_chunk_size(dir); | |
111 | char *kaddr = page_address(page); | |
112 | u32 max_inumber = le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count); | |
113 | unsigned offs, rec_len; | |
114 | unsigned limit = PAGE_CACHE_SIZE; | |
115 | ext2_dirent *p; | |
116 | char *error; | |
117 | ||
118 | if ((dir->i_size >> PAGE_CACHE_SHIFT) == page->index) { | |
119 | limit = dir->i_size & ~PAGE_CACHE_MASK; | |
120 | if (limit & (chunk_size - 1)) | |
121 | goto Ebadsize; | |
122 | if (!limit) | |
123 | goto out; | |
124 | } | |
125 | for (offs = 0; offs <= limit - EXT2_DIR_REC_LEN(1); offs += rec_len) { | |
126 | p = (ext2_dirent *)(kaddr + offs); | |
89910ccc | 127 | rec_len = ext2_rec_len_from_disk(p->rec_len); |
1da177e4 LT |
128 | |
129 | if (rec_len < EXT2_DIR_REC_LEN(1)) | |
130 | goto Eshort; | |
131 | if (rec_len & 3) | |
132 | goto Ealign; | |
133 | if (rec_len < EXT2_DIR_REC_LEN(p->name_len)) | |
134 | goto Enamelen; | |
135 | if (((offs + rec_len - 1) ^ offs) & ~(chunk_size-1)) | |
136 | goto Espan; | |
137 | if (le32_to_cpu(p->inode) > max_inumber) | |
138 | goto Einumber; | |
139 | } | |
140 | if (offs != limit) | |
141 | goto Eend; | |
142 | out: | |
143 | SetPageChecked(page); | |
144 | return; | |
145 | ||
146 | /* Too bad, we had an error */ | |
147 | ||
148 | Ebadsize: | |
149 | ext2_error(sb, "ext2_check_page", | |
150 | "size of directory #%lu is not a multiple of chunk size", | |
151 | dir->i_ino | |
152 | ); | |
153 | goto fail; | |
154 | Eshort: | |
155 | error = "rec_len is smaller than minimal"; | |
156 | goto bad_entry; | |
157 | Ealign: | |
158 | error = "unaligned directory entry"; | |
159 | goto bad_entry; | |
160 | Enamelen: | |
161 | error = "rec_len is too small for name_len"; | |
162 | goto bad_entry; | |
163 | Espan: | |
164 | error = "directory entry across blocks"; | |
165 | goto bad_entry; | |
166 | Einumber: | |
167 | error = "inode out of bounds"; | |
168 | bad_entry: | |
169 | ext2_error (sb, "ext2_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) le32_to_cpu(p->inode), | |
173 | rec_len, p->name_len); | |
174 | goto fail; | |
175 | Eend: | |
176 | p = (ext2_dirent *)(kaddr + offs); | |
177 | ext2_error (sb, "ext2_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) le32_to_cpu(p->inode)); | |
182 | fail: | |
183 | SetPageChecked(page); | |
184 | SetPageError(page); | |
185 | } | |
186 | ||
187 | static struct page * ext2_get_page(struct inode *dir, unsigned long n) | |
188 | { | |
189 | struct address_space *mapping = dir->i_mapping; | |
090d2b18 | 190 | struct page *page = read_mapping_page(mapping, n, NULL); |
1da177e4 | 191 | if (!IS_ERR(page)) { |
1da177e4 | 192 | kmap(page); |
1da177e4 LT |
193 | if (!PageChecked(page)) |
194 | ext2_check_page(page); | |
195 | if (PageError(page)) | |
196 | goto fail; | |
197 | } | |
198 | return page; | |
199 | ||
200 | fail: | |
201 | ext2_put_page(page); | |
202 | return ERR_PTR(-EIO); | |
203 | } | |
204 | ||
205 | /* | |
206 | * NOTE! unlike strncmp, ext2_match returns 1 for success, 0 for failure. | |
207 | * | |
208 | * len <= EXT2_NAME_LEN and de != NULL are guaranteed by caller. | |
209 | */ | |
210 | static inline int ext2_match (int len, const char * const name, | |
211 | struct ext2_dir_entry_2 * de) | |
212 | { | |
213 | if (len != de->name_len) | |
214 | return 0; | |
215 | if (!de->inode) | |
216 | return 0; | |
217 | return !memcmp(name, de->name, len); | |
218 | } | |
219 | ||
220 | /* | |
221 | * p is at least 6 bytes before the end of page | |
222 | */ | |
223 | static inline ext2_dirent *ext2_next_entry(ext2_dirent *p) | |
224 | { | |
89910ccc JK |
225 | return (ext2_dirent *)((char *)p + |
226 | ext2_rec_len_from_disk(p->rec_len)); | |
1da177e4 LT |
227 | } |
228 | ||
229 | static inline unsigned | |
230 | ext2_validate_entry(char *base, unsigned offset, unsigned mask) | |
231 | { | |
232 | ext2_dirent *de = (ext2_dirent*)(base + offset); | |
233 | ext2_dirent *p = (ext2_dirent*)(base + (offset&mask)); | |
234 | while ((char*)p < (char*)de) { | |
235 | if (p->rec_len == 0) | |
236 | break; | |
237 | p = ext2_next_entry(p); | |
238 | } | |
239 | return (char *)p - base; | |
240 | } | |
241 | ||
242 | static unsigned char ext2_filetype_table[EXT2_FT_MAX] = { | |
243 | [EXT2_FT_UNKNOWN] = DT_UNKNOWN, | |
244 | [EXT2_FT_REG_FILE] = DT_REG, | |
245 | [EXT2_FT_DIR] = DT_DIR, | |
246 | [EXT2_FT_CHRDEV] = DT_CHR, | |
247 | [EXT2_FT_BLKDEV] = DT_BLK, | |
248 | [EXT2_FT_FIFO] = DT_FIFO, | |
249 | [EXT2_FT_SOCK] = DT_SOCK, | |
250 | [EXT2_FT_SYMLINK] = DT_LNK, | |
251 | }; | |
252 | ||
253 | #define S_SHIFT 12 | |
254 | static unsigned char ext2_type_by_mode[S_IFMT >> S_SHIFT] = { | |
255 | [S_IFREG >> S_SHIFT] = EXT2_FT_REG_FILE, | |
256 | [S_IFDIR >> S_SHIFT] = EXT2_FT_DIR, | |
257 | [S_IFCHR >> S_SHIFT] = EXT2_FT_CHRDEV, | |
258 | [S_IFBLK >> S_SHIFT] = EXT2_FT_BLKDEV, | |
259 | [S_IFIFO >> S_SHIFT] = EXT2_FT_FIFO, | |
260 | [S_IFSOCK >> S_SHIFT] = EXT2_FT_SOCK, | |
261 | [S_IFLNK >> S_SHIFT] = EXT2_FT_SYMLINK, | |
262 | }; | |
263 | ||
264 | static inline void ext2_set_de_type(ext2_dirent *de, struct inode *inode) | |
265 | { | |
266 | mode_t mode = inode->i_mode; | |
267 | if (EXT2_HAS_INCOMPAT_FEATURE(inode->i_sb, EXT2_FEATURE_INCOMPAT_FILETYPE)) | |
268 | de->file_type = ext2_type_by_mode[(mode & S_IFMT)>>S_SHIFT]; | |
269 | else | |
270 | de->file_type = 0; | |
271 | } | |
272 | ||
273 | static int | |
274 | ext2_readdir (struct file * filp, void * dirent, filldir_t filldir) | |
275 | { | |
276 | loff_t pos = filp->f_pos; | |
c29c6934 | 277 | struct inode *inode = filp->f_path.dentry->d_inode; |
1da177e4 LT |
278 | struct super_block *sb = inode->i_sb; |
279 | unsigned int offset = pos & ~PAGE_CACHE_MASK; | |
280 | unsigned long n = pos >> PAGE_CACHE_SHIFT; | |
281 | unsigned long npages = dir_pages(inode); | |
282 | unsigned chunk_mask = ~(ext2_chunk_size(inode)-1); | |
283 | unsigned char *types = NULL; | |
2d7f2ea9 | 284 | int need_revalidate = filp->f_version != inode->i_version; |
1da177e4 LT |
285 | |
286 | if (pos > inode->i_size - EXT2_DIR_REC_LEN(1)) | |
2d7f2ea9 | 287 | return 0; |
1da177e4 LT |
288 | |
289 | if (EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_FILETYPE)) | |
290 | types = ext2_filetype_table; | |
291 | ||
292 | for ( ; n < npages; n++, offset = 0) { | |
293 | char *kaddr, *limit; | |
294 | ext2_dirent *de; | |
295 | struct page *page = ext2_get_page(inode, n); | |
296 | ||
297 | if (IS_ERR(page)) { | |
298 | ext2_error(sb, __FUNCTION__, | |
299 | "bad page in #%lu", | |
300 | inode->i_ino); | |
301 | filp->f_pos += PAGE_CACHE_SIZE - offset; | |
bbff2860 | 302 | return PTR_ERR(page); |
1da177e4 LT |
303 | } |
304 | kaddr = page_address(page); | |
2d7f2ea9 AV |
305 | if (unlikely(need_revalidate)) { |
306 | if (offset) { | |
307 | offset = ext2_validate_entry(kaddr, offset, chunk_mask); | |
308 | filp->f_pos = (n<<PAGE_CACHE_SHIFT) + offset; | |
309 | } | |
310 | filp->f_version = inode->i_version; | |
1da177e4 LT |
311 | need_revalidate = 0; |
312 | } | |
313 | de = (ext2_dirent *)(kaddr+offset); | |
314 | limit = kaddr + ext2_last_byte(inode, n) - EXT2_DIR_REC_LEN(1); | |
315 | for ( ;(char*)de <= limit; de = ext2_next_entry(de)) { | |
316 | if (de->rec_len == 0) { | |
317 | ext2_error(sb, __FUNCTION__, | |
318 | "zero-length directory entry"); | |
1da177e4 | 319 | ext2_put_page(page); |
2d7f2ea9 | 320 | return -EIO; |
1da177e4 LT |
321 | } |
322 | if (de->inode) { | |
323 | int over; | |
324 | unsigned char d_type = DT_UNKNOWN; | |
325 | ||
326 | if (types && de->file_type < EXT2_FT_MAX) | |
327 | d_type = types[de->file_type]; | |
328 | ||
329 | offset = (char *)de - kaddr; | |
330 | over = filldir(dirent, de->name, de->name_len, | |
331 | (n<<PAGE_CACHE_SHIFT) | offset, | |
332 | le32_to_cpu(de->inode), d_type); | |
333 | if (over) { | |
334 | ext2_put_page(page); | |
2d7f2ea9 | 335 | return 0; |
1da177e4 LT |
336 | } |
337 | } | |
89910ccc | 338 | filp->f_pos += ext2_rec_len_from_disk(de->rec_len); |
1da177e4 LT |
339 | } |
340 | ext2_put_page(page); | |
341 | } | |
2d7f2ea9 | 342 | return 0; |
1da177e4 LT |
343 | } |
344 | ||
345 | /* | |
346 | * ext2_find_entry() | |
347 | * | |
348 | * finds an entry in the specified directory with the wanted name. It | |
349 | * returns the page in which the entry was found, and the entry itself | |
350 | * (as a parameter - res_dir). Page is returned mapped and unlocked. | |
351 | * Entry is guaranteed to be valid. | |
352 | */ | |
353 | struct ext2_dir_entry_2 * ext2_find_entry (struct inode * dir, | |
354 | struct dentry *dentry, struct page ** res_page) | |
355 | { | |
356 | const char *name = dentry->d_name.name; | |
357 | int namelen = dentry->d_name.len; | |
358 | unsigned reclen = EXT2_DIR_REC_LEN(namelen); | |
359 | unsigned long start, n; | |
360 | unsigned long npages = dir_pages(dir); | |
361 | struct page *page = NULL; | |
362 | struct ext2_inode_info *ei = EXT2_I(dir); | |
363 | ext2_dirent * de; | |
364 | ||
365 | if (npages == 0) | |
366 | goto out; | |
367 | ||
368 | /* OFFSET_CACHE */ | |
369 | *res_page = NULL; | |
370 | ||
371 | start = ei->i_dir_start_lookup; | |
372 | if (start >= npages) | |
373 | start = 0; | |
374 | n = start; | |
375 | do { | |
376 | char *kaddr; | |
377 | page = ext2_get_page(dir, n); | |
378 | if (!IS_ERR(page)) { | |
379 | kaddr = page_address(page); | |
380 | de = (ext2_dirent *) kaddr; | |
381 | kaddr += ext2_last_byte(dir, n) - reclen; | |
382 | while ((char *) de <= kaddr) { | |
383 | if (de->rec_len == 0) { | |
384 | ext2_error(dir->i_sb, __FUNCTION__, | |
385 | "zero-length directory entry"); | |
386 | ext2_put_page(page); | |
387 | goto out; | |
388 | } | |
389 | if (ext2_match (namelen, name, de)) | |
390 | goto found; | |
391 | de = ext2_next_entry(de); | |
392 | } | |
393 | ext2_put_page(page); | |
394 | } | |
395 | if (++n >= npages) | |
396 | n = 0; | |
d8adb9ce ES |
397 | /* next page is past the blocks we've got */ |
398 | if (unlikely(n > (dir->i_blocks >> (PAGE_CACHE_SHIFT - 9)))) { | |
399 | ext2_error(dir->i_sb, __FUNCTION__, | |
400 | "dir %lu size %lld exceeds block count %llu", | |
401 | dir->i_ino, dir->i_size, | |
402 | (unsigned long long)dir->i_blocks); | |
403 | goto out; | |
404 | } | |
1da177e4 LT |
405 | } while (n != start); |
406 | out: | |
407 | return NULL; | |
408 | ||
409 | found: | |
410 | *res_page = page; | |
411 | ei->i_dir_start_lookup = n; | |
412 | return de; | |
413 | } | |
414 | ||
415 | struct ext2_dir_entry_2 * ext2_dotdot (struct inode *dir, struct page **p) | |
416 | { | |
417 | struct page *page = ext2_get_page(dir, 0); | |
418 | ext2_dirent *de = NULL; | |
419 | ||
420 | if (!IS_ERR(page)) { | |
421 | de = ext2_next_entry((ext2_dirent *) page_address(page)); | |
422 | *p = page; | |
423 | } | |
424 | return de; | |
425 | } | |
426 | ||
427 | ino_t ext2_inode_by_name(struct inode * dir, struct dentry *dentry) | |
428 | { | |
429 | ino_t res = 0; | |
430 | struct ext2_dir_entry_2 * de; | |
431 | struct page *page; | |
432 | ||
433 | de = ext2_find_entry (dir, dentry, &page); | |
434 | if (de) { | |
435 | res = le32_to_cpu(de->inode); | |
7d93a1a5 | 436 | ext2_put_page(page); |
1da177e4 LT |
437 | } |
438 | return res; | |
439 | } | |
440 | ||
441 | /* Releases the page */ | |
442 | void ext2_set_link(struct inode *dir, struct ext2_dir_entry_2 *de, | |
443 | struct page *page, struct inode *inode) | |
444 | { | |
f34fb6ec NP |
445 | loff_t pos = page_offset(page) + |
446 | (char *) de - (char *) page_address(page); | |
89910ccc | 447 | unsigned len = ext2_rec_len_from_disk(de->rec_len); |
1da177e4 LT |
448 | int err; |
449 | ||
450 | lock_page(page); | |
f34fb6ec NP |
451 | err = __ext2_write_begin(NULL, page->mapping, pos, len, |
452 | AOP_FLAG_UNINTERRUPTIBLE, &page, NULL); | |
309be53d | 453 | BUG_ON(err); |
1da177e4 | 454 | de->inode = cpu_to_le32(inode->i_ino); |
f34fb6ec NP |
455 | ext2_set_de_type(de, inode); |
456 | err = ext2_commit_chunk(page, pos, len); | |
1da177e4 LT |
457 | ext2_put_page(page); |
458 | dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC; | |
459 | EXT2_I(dir)->i_flags &= ~EXT2_BTREE_FL; | |
460 | mark_inode_dirty(dir); | |
461 | } | |
462 | ||
463 | /* | |
464 | * Parent is locked. | |
465 | */ | |
466 | int ext2_add_link (struct dentry *dentry, struct inode *inode) | |
467 | { | |
468 | struct inode *dir = dentry->d_parent->d_inode; | |
469 | const char *name = dentry->d_name.name; | |
470 | int namelen = dentry->d_name.len; | |
471 | unsigned chunk_size = ext2_chunk_size(dir); | |
472 | unsigned reclen = EXT2_DIR_REC_LEN(namelen); | |
473 | unsigned short rec_len, name_len; | |
474 | struct page *page = NULL; | |
475 | ext2_dirent * de; | |
476 | unsigned long npages = dir_pages(dir); | |
477 | unsigned long n; | |
478 | char *kaddr; | |
f34fb6ec | 479 | loff_t pos; |
1da177e4 LT |
480 | int err; |
481 | ||
482 | /* | |
483 | * We take care of directory expansion in the same loop. | |
484 | * This code plays outside i_size, so it locks the page | |
485 | * to protect that region. | |
486 | */ | |
487 | for (n = 0; n <= npages; n++) { | |
488 | char *dir_end; | |
489 | ||
490 | page = ext2_get_page(dir, n); | |
491 | err = PTR_ERR(page); | |
492 | if (IS_ERR(page)) | |
493 | goto out; | |
494 | lock_page(page); | |
495 | kaddr = page_address(page); | |
496 | dir_end = kaddr + ext2_last_byte(dir, n); | |
497 | de = (ext2_dirent *)kaddr; | |
498 | kaddr += PAGE_CACHE_SIZE - reclen; | |
499 | while ((char *)de <= kaddr) { | |
500 | if ((char *)de == dir_end) { | |
501 | /* We hit i_size */ | |
502 | name_len = 0; | |
503 | rec_len = chunk_size; | |
89910ccc | 504 | de->rec_len = ext2_rec_len_to_disk(chunk_size); |
1da177e4 LT |
505 | de->inode = 0; |
506 | goto got_it; | |
507 | } | |
508 | if (de->rec_len == 0) { | |
509 | ext2_error(dir->i_sb, __FUNCTION__, | |
510 | "zero-length directory entry"); | |
511 | err = -EIO; | |
512 | goto out_unlock; | |
513 | } | |
514 | err = -EEXIST; | |
515 | if (ext2_match (namelen, name, de)) | |
516 | goto out_unlock; | |
517 | name_len = EXT2_DIR_REC_LEN(de->name_len); | |
89910ccc | 518 | rec_len = ext2_rec_len_from_disk(de->rec_len); |
1da177e4 LT |
519 | if (!de->inode && rec_len >= reclen) |
520 | goto got_it; | |
521 | if (rec_len >= name_len + reclen) | |
522 | goto got_it; | |
523 | de = (ext2_dirent *) ((char *) de + rec_len); | |
524 | } | |
525 | unlock_page(page); | |
526 | ext2_put_page(page); | |
527 | } | |
528 | BUG(); | |
529 | return -EINVAL; | |
530 | ||
531 | got_it: | |
f34fb6ec NP |
532 | pos = page_offset(page) + |
533 | (char*)de - (char*)page_address(page); | |
534 | err = __ext2_write_begin(NULL, page->mapping, pos, rec_len, 0, | |
535 | &page, NULL); | |
1da177e4 LT |
536 | if (err) |
537 | goto out_unlock; | |
538 | if (de->inode) { | |
539 | ext2_dirent *de1 = (ext2_dirent *) ((char *) de + name_len); | |
89910ccc JK |
540 | de1->rec_len = ext2_rec_len_to_disk(rec_len - name_len); |
541 | de->rec_len = ext2_rec_len_to_disk(name_len); | |
1da177e4 LT |
542 | de = de1; |
543 | } | |
544 | de->name_len = namelen; | |
f34fb6ec | 545 | memcpy(de->name, name, namelen); |
1da177e4 LT |
546 | de->inode = cpu_to_le32(inode->i_ino); |
547 | ext2_set_de_type (de, inode); | |
f34fb6ec | 548 | err = ext2_commit_chunk(page, pos, rec_len); |
1da177e4 LT |
549 | dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC; |
550 | EXT2_I(dir)->i_flags &= ~EXT2_BTREE_FL; | |
551 | mark_inode_dirty(dir); | |
552 | /* OFFSET_CACHE */ | |
553 | out_put: | |
554 | ext2_put_page(page); | |
555 | out: | |
556 | return err; | |
557 | out_unlock: | |
558 | unlock_page(page); | |
559 | goto out_put; | |
560 | } | |
561 | ||
562 | /* | |
563 | * ext2_delete_entry deletes a directory entry by merging it with the | |
564 | * previous entry. Page is up-to-date. Releases the page. | |
565 | */ | |
566 | int ext2_delete_entry (struct ext2_dir_entry_2 * dir, struct page * page ) | |
567 | { | |
568 | struct address_space *mapping = page->mapping; | |
569 | struct inode *inode = mapping->host; | |
570 | char *kaddr = page_address(page); | |
571 | unsigned from = ((char*)dir - kaddr) & ~(ext2_chunk_size(inode)-1); | |
89910ccc JK |
572 | unsigned to = ((char *)dir - kaddr) + |
573 | ext2_rec_len_from_disk(dir->rec_len); | |
f34fb6ec | 574 | loff_t pos; |
1da177e4 LT |
575 | ext2_dirent * pde = NULL; |
576 | ext2_dirent * de = (ext2_dirent *) (kaddr + from); | |
577 | int err; | |
578 | ||
579 | while ((char*)de < (char*)dir) { | |
580 | if (de->rec_len == 0) { | |
581 | ext2_error(inode->i_sb, __FUNCTION__, | |
582 | "zero-length directory entry"); | |
583 | err = -EIO; | |
584 | goto out; | |
585 | } | |
586 | pde = de; | |
587 | de = ext2_next_entry(de); | |
588 | } | |
589 | if (pde) | |
590 | from = (char*)pde - (char*)page_address(page); | |
f34fb6ec | 591 | pos = page_offset(page) + from; |
1da177e4 | 592 | lock_page(page); |
f34fb6ec NP |
593 | err = __ext2_write_begin(NULL, page->mapping, pos, to - from, 0, |
594 | &page, NULL); | |
309be53d | 595 | BUG_ON(err); |
1da177e4 | 596 | if (pde) |
89910ccc | 597 | pde->rec_len = ext2_rec_len_to_disk(to - from); |
1da177e4 | 598 | dir->inode = 0; |
f34fb6ec | 599 | err = ext2_commit_chunk(page, pos, to - from); |
1da177e4 LT |
600 | inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC; |
601 | EXT2_I(inode)->i_flags &= ~EXT2_BTREE_FL; | |
602 | mark_inode_dirty(inode); | |
603 | out: | |
604 | ext2_put_page(page); | |
605 | return err; | |
606 | } | |
607 | ||
608 | /* | |
609 | * Set the first fragment of directory. | |
610 | */ | |
611 | int ext2_make_empty(struct inode *inode, struct inode *parent) | |
612 | { | |
613 | struct address_space *mapping = inode->i_mapping; | |
614 | struct page *page = grab_cache_page(mapping, 0); | |
615 | unsigned chunk_size = ext2_chunk_size(inode); | |
616 | struct ext2_dir_entry_2 * de; | |
617 | int err; | |
618 | void *kaddr; | |
619 | ||
620 | if (!page) | |
621 | return -ENOMEM; | |
f34fb6ec NP |
622 | |
623 | err = __ext2_write_begin(NULL, page->mapping, 0, chunk_size, 0, | |
624 | &page, NULL); | |
1da177e4 LT |
625 | if (err) { |
626 | unlock_page(page); | |
627 | goto fail; | |
628 | } | |
629 | kaddr = kmap_atomic(page, KM_USER0); | |
7823c7c1 | 630 | memset(kaddr, 0, chunk_size); |
1da177e4 LT |
631 | de = (struct ext2_dir_entry_2 *)kaddr; |
632 | de->name_len = 1; | |
89910ccc | 633 | de->rec_len = ext2_rec_len_to_disk(EXT2_DIR_REC_LEN(1)); |
1da177e4 LT |
634 | memcpy (de->name, ".\0\0", 4); |
635 | de->inode = cpu_to_le32(inode->i_ino); | |
636 | ext2_set_de_type (de, inode); | |
637 | ||
638 | de = (struct ext2_dir_entry_2 *)(kaddr + EXT2_DIR_REC_LEN(1)); | |
639 | de->name_len = 2; | |
89910ccc | 640 | de->rec_len = ext2_rec_len_to_disk(chunk_size - EXT2_DIR_REC_LEN(1)); |
1da177e4 LT |
641 | de->inode = cpu_to_le32(parent->i_ino); |
642 | memcpy (de->name, "..\0", 4); | |
643 | ext2_set_de_type (de, inode); | |
644 | kunmap_atomic(kaddr, KM_USER0); | |
645 | err = ext2_commit_chunk(page, 0, chunk_size); | |
646 | fail: | |
647 | page_cache_release(page); | |
648 | return err; | |
649 | } | |
650 | ||
651 | /* | |
652 | * routine to check that the specified directory is empty (for rmdir) | |
653 | */ | |
654 | int ext2_empty_dir (struct inode * inode) | |
655 | { | |
656 | struct page *page = NULL; | |
657 | unsigned long i, npages = dir_pages(inode); | |
658 | ||
659 | for (i = 0; i < npages; i++) { | |
660 | char *kaddr; | |
661 | ext2_dirent * de; | |
662 | page = ext2_get_page(inode, i); | |
663 | ||
664 | if (IS_ERR(page)) | |
665 | continue; | |
666 | ||
667 | kaddr = page_address(page); | |
668 | de = (ext2_dirent *)kaddr; | |
669 | kaddr += ext2_last_byte(inode, i) - EXT2_DIR_REC_LEN(1); | |
670 | ||
671 | while ((char *)de <= kaddr) { | |
672 | if (de->rec_len == 0) { | |
673 | ext2_error(inode->i_sb, __FUNCTION__, | |
674 | "zero-length directory entry"); | |
675 | printk("kaddr=%p, de=%p\n", kaddr, de); | |
676 | goto not_empty; | |
677 | } | |
678 | if (de->inode != 0) { | |
679 | /* check for . and .. */ | |
680 | if (de->name[0] != '.') | |
681 | goto not_empty; | |
682 | if (de->name_len > 2) | |
683 | goto not_empty; | |
684 | if (de->name_len < 2) { | |
685 | if (de->inode != | |
686 | cpu_to_le32(inode->i_ino)) | |
687 | goto not_empty; | |
688 | } else if (de->name[1] != '.') | |
689 | goto not_empty; | |
690 | } | |
691 | de = ext2_next_entry(de); | |
692 | } | |
693 | ext2_put_page(page); | |
694 | } | |
695 | return 1; | |
696 | ||
697 | not_empty: | |
698 | ext2_put_page(page); | |
699 | return 0; | |
700 | } | |
701 | ||
4b6f5d20 | 702 | const struct file_operations ext2_dir_operations = { |
1da177e4 LT |
703 | .llseek = generic_file_llseek, |
704 | .read = generic_read_dir, | |
705 | .readdir = ext2_readdir, | |
14f9f7b2 | 706 | .unlocked_ioctl = ext2_ioctl, |
e322ff07 DH |
707 | #ifdef CONFIG_COMPAT |
708 | .compat_ioctl = ext2_compat_ioctl, | |
709 | #endif | |
1da177e4 LT |
710 | .fsync = ext2_sync_file, |
711 | }; |