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 | ||
40a063f6 ES |
31 | /* |
32 | * Tests against MAX_REC_LEN etc were put in place for 64k block | |
33 | * sizes; if that is not possible on this arch, we can skip | |
34 | * those tests and speed things up. | |
35 | */ | |
89910ccc JK |
36 | static inline unsigned ext2_rec_len_from_disk(__le16 dlen) |
37 | { | |
38 | unsigned len = le16_to_cpu(dlen); | |
39 | ||
40a063f6 | 40 | #if (PAGE_CACHE_SIZE >= 65536) |
89910ccc JK |
41 | if (len == EXT2_MAX_REC_LEN) |
42 | return 1 << 16; | |
40a063f6 | 43 | #endif |
89910ccc JK |
44 | return len; |
45 | } | |
46 | ||
47 | static inline __le16 ext2_rec_len_to_disk(unsigned len) | |
48 | { | |
40a063f6 | 49 | #if (PAGE_CACHE_SIZE >= 65536) |
89910ccc JK |
50 | if (len == (1 << 16)) |
51 | return cpu_to_le16(EXT2_MAX_REC_LEN); | |
2c11619a JL |
52 | else |
53 | BUG_ON(len > (1 << 16)); | |
40a063f6 | 54 | #endif |
89910ccc JK |
55 | return cpu_to_le16(len); |
56 | } | |
57 | ||
1da177e4 LT |
58 | /* |
59 | * ext2 uses block-sized chunks. Arguably, sector-sized ones would be | |
60 | * more robust, but we have what we have | |
61 | */ | |
62 | static inline unsigned ext2_chunk_size(struct inode *inode) | |
63 | { | |
64 | return inode->i_sb->s_blocksize; | |
65 | } | |
66 | ||
67 | static inline void ext2_put_page(struct page *page) | |
68 | { | |
69 | kunmap(page); | |
70 | page_cache_release(page); | |
71 | } | |
72 | ||
73 | static inline unsigned long dir_pages(struct inode *inode) | |
74 | { | |
75 | return (inode->i_size+PAGE_CACHE_SIZE-1)>>PAGE_CACHE_SHIFT; | |
76 | } | |
77 | ||
78 | /* | |
79 | * Return the offset into page `page_nr' of the last valid | |
80 | * byte in that page, plus one. | |
81 | */ | |
82 | static unsigned | |
83 | ext2_last_byte(struct inode *inode, unsigned long page_nr) | |
84 | { | |
85 | unsigned last_byte = inode->i_size; | |
86 | ||
87 | last_byte -= page_nr << PAGE_CACHE_SHIFT; | |
88 | if (last_byte > PAGE_CACHE_SIZE) | |
89 | last_byte = PAGE_CACHE_SIZE; | |
90 | return last_byte; | |
91 | } | |
92 | ||
f34fb6ec | 93 | static int ext2_commit_chunk(struct page *page, loff_t pos, unsigned len) |
1da177e4 | 94 | { |
f34fb6ec NP |
95 | struct address_space *mapping = page->mapping; |
96 | struct inode *dir = mapping->host; | |
1da177e4 | 97 | int err = 0; |
f34fb6ec | 98 | |
1da177e4 | 99 | dir->i_version++; |
f34fb6ec NP |
100 | block_write_end(NULL, mapping, pos, len, len, page, NULL); |
101 | ||
102 | if (pos+len > dir->i_size) { | |
103 | i_size_write(dir, pos+len); | |
104 | mark_inode_dirty(dir); | |
105 | } | |
106 | ||
6b7021ef | 107 | if (IS_DIRSYNC(dir)) { |
1da177e4 | 108 | err = write_one_page(page, 1); |
6b7021ef | 109 | if (!err) |
c3765016 | 110 | err = sync_inode_metadata(dir, 1); |
6b7021ef | 111 | } else { |
1da177e4 | 112 | unlock_page(page); |
6b7021ef | 113 | } |
f34fb6ec | 114 | |
1da177e4 LT |
115 | return err; |
116 | } | |
117 | ||
bd39597c | 118 | static void ext2_check_page(struct page *page, int quiet) |
1da177e4 LT |
119 | { |
120 | struct inode *dir = page->mapping->host; | |
121 | struct super_block *sb = dir->i_sb; | |
122 | unsigned chunk_size = ext2_chunk_size(dir); | |
123 | char *kaddr = page_address(page); | |
124 | u32 max_inumber = le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count); | |
125 | unsigned offs, rec_len; | |
126 | unsigned limit = PAGE_CACHE_SIZE; | |
127 | ext2_dirent *p; | |
128 | char *error; | |
129 | ||
130 | if ((dir->i_size >> PAGE_CACHE_SHIFT) == page->index) { | |
131 | limit = dir->i_size & ~PAGE_CACHE_MASK; | |
132 | if (limit & (chunk_size - 1)) | |
133 | goto Ebadsize; | |
134 | if (!limit) | |
135 | goto out; | |
136 | } | |
137 | for (offs = 0; offs <= limit - EXT2_DIR_REC_LEN(1); offs += rec_len) { | |
138 | p = (ext2_dirent *)(kaddr + offs); | |
89910ccc | 139 | rec_len = ext2_rec_len_from_disk(p->rec_len); |
1da177e4 | 140 | |
40a063f6 | 141 | if (unlikely(rec_len < EXT2_DIR_REC_LEN(1))) |
1da177e4 | 142 | goto Eshort; |
40a063f6 | 143 | if (unlikely(rec_len & 3)) |
1da177e4 | 144 | goto Ealign; |
40a063f6 | 145 | if (unlikely(rec_len < EXT2_DIR_REC_LEN(p->name_len))) |
1da177e4 | 146 | goto Enamelen; |
40a063f6 | 147 | if (unlikely(((offs + rec_len - 1) ^ offs) & ~(chunk_size-1))) |
1da177e4 | 148 | goto Espan; |
40a063f6 | 149 | if (unlikely(le32_to_cpu(p->inode) > max_inumber)) |
1da177e4 LT |
150 | goto Einumber; |
151 | } | |
152 | if (offs != limit) | |
153 | goto Eend; | |
154 | out: | |
155 | SetPageChecked(page); | |
156 | return; | |
157 | ||
158 | /* Too bad, we had an error */ | |
159 | ||
160 | Ebadsize: | |
bd39597c ES |
161 | if (!quiet) |
162 | ext2_error(sb, __func__, | |
163 | "size of directory #%lu is not a multiple " | |
164 | "of chunk size", dir->i_ino); | |
1da177e4 LT |
165 | goto fail; |
166 | Eshort: | |
167 | error = "rec_len is smaller than minimal"; | |
168 | goto bad_entry; | |
169 | Ealign: | |
170 | error = "unaligned directory entry"; | |
171 | goto bad_entry; | |
172 | Enamelen: | |
173 | error = "rec_len is too small for name_len"; | |
174 | goto bad_entry; | |
175 | Espan: | |
176 | error = "directory entry across blocks"; | |
177 | goto bad_entry; | |
178 | Einumber: | |
179 | error = "inode out of bounds"; | |
180 | bad_entry: | |
bd39597c ES |
181 | if (!quiet) |
182 | ext2_error(sb, __func__, "bad entry in directory #%lu: : %s - " | |
183 | "offset=%lu, inode=%lu, rec_len=%d, name_len=%d", | |
184 | dir->i_ino, error, (page->index<<PAGE_CACHE_SHIFT)+offs, | |
185 | (unsigned long) le32_to_cpu(p->inode), | |
186 | rec_len, p->name_len); | |
1da177e4 LT |
187 | goto fail; |
188 | Eend: | |
bd39597c ES |
189 | if (!quiet) { |
190 | p = (ext2_dirent *)(kaddr + offs); | |
191 | ext2_error(sb, "ext2_check_page", | |
192 | "entry in directory #%lu spans the page boundary" | |
193 | "offset=%lu, inode=%lu", | |
194 | dir->i_ino, (page->index<<PAGE_CACHE_SHIFT)+offs, | |
195 | (unsigned long) le32_to_cpu(p->inode)); | |
196 | } | |
1da177e4 LT |
197 | fail: |
198 | SetPageChecked(page); | |
199 | SetPageError(page); | |
200 | } | |
201 | ||
bd39597c ES |
202 | static struct page * ext2_get_page(struct inode *dir, unsigned long n, |
203 | int quiet) | |
1da177e4 LT |
204 | { |
205 | struct address_space *mapping = dir->i_mapping; | |
090d2b18 | 206 | struct page *page = read_mapping_page(mapping, n, NULL); |
1da177e4 | 207 | if (!IS_ERR(page)) { |
1da177e4 | 208 | kmap(page); |
1da177e4 | 209 | if (!PageChecked(page)) |
bd39597c | 210 | ext2_check_page(page, quiet); |
1da177e4 LT |
211 | if (PageError(page)) |
212 | goto fail; | |
213 | } | |
214 | return page; | |
215 | ||
216 | fail: | |
217 | ext2_put_page(page); | |
218 | return ERR_PTR(-EIO); | |
219 | } | |
220 | ||
221 | /* | |
222 | * NOTE! unlike strncmp, ext2_match returns 1 for success, 0 for failure. | |
223 | * | |
224 | * len <= EXT2_NAME_LEN and de != NULL are guaranteed by caller. | |
225 | */ | |
226 | static inline int ext2_match (int len, const char * const name, | |
227 | struct ext2_dir_entry_2 * de) | |
228 | { | |
229 | if (len != de->name_len) | |
230 | return 0; | |
231 | if (!de->inode) | |
232 | return 0; | |
233 | return !memcmp(name, de->name, len); | |
234 | } | |
235 | ||
236 | /* | |
237 | * p is at least 6 bytes before the end of page | |
238 | */ | |
239 | static inline ext2_dirent *ext2_next_entry(ext2_dirent *p) | |
240 | { | |
89910ccc JK |
241 | return (ext2_dirent *)((char *)p + |
242 | ext2_rec_len_from_disk(p->rec_len)); | |
1da177e4 LT |
243 | } |
244 | ||
245 | static inline unsigned | |
246 | ext2_validate_entry(char *base, unsigned offset, unsigned mask) | |
247 | { | |
248 | ext2_dirent *de = (ext2_dirent*)(base + offset); | |
249 | ext2_dirent *p = (ext2_dirent*)(base + (offset&mask)); | |
250 | while ((char*)p < (char*)de) { | |
251 | if (p->rec_len == 0) | |
252 | break; | |
253 | p = ext2_next_entry(p); | |
254 | } | |
255 | return (char *)p - base; | |
256 | } | |
257 | ||
258 | static unsigned char ext2_filetype_table[EXT2_FT_MAX] = { | |
259 | [EXT2_FT_UNKNOWN] = DT_UNKNOWN, | |
260 | [EXT2_FT_REG_FILE] = DT_REG, | |
261 | [EXT2_FT_DIR] = DT_DIR, | |
262 | [EXT2_FT_CHRDEV] = DT_CHR, | |
263 | [EXT2_FT_BLKDEV] = DT_BLK, | |
264 | [EXT2_FT_FIFO] = DT_FIFO, | |
265 | [EXT2_FT_SOCK] = DT_SOCK, | |
266 | [EXT2_FT_SYMLINK] = DT_LNK, | |
267 | }; | |
268 | ||
269 | #define S_SHIFT 12 | |
270 | static unsigned char ext2_type_by_mode[S_IFMT >> S_SHIFT] = { | |
271 | [S_IFREG >> S_SHIFT] = EXT2_FT_REG_FILE, | |
272 | [S_IFDIR >> S_SHIFT] = EXT2_FT_DIR, | |
273 | [S_IFCHR >> S_SHIFT] = EXT2_FT_CHRDEV, | |
274 | [S_IFBLK >> S_SHIFT] = EXT2_FT_BLKDEV, | |
275 | [S_IFIFO >> S_SHIFT] = EXT2_FT_FIFO, | |
276 | [S_IFSOCK >> S_SHIFT] = EXT2_FT_SOCK, | |
277 | [S_IFLNK >> S_SHIFT] = EXT2_FT_SYMLINK, | |
278 | }; | |
279 | ||
280 | static inline void ext2_set_de_type(ext2_dirent *de, struct inode *inode) | |
281 | { | |
3ea40bc9 | 282 | umode_t mode = inode->i_mode; |
1da177e4 LT |
283 | if (EXT2_HAS_INCOMPAT_FEATURE(inode->i_sb, EXT2_FEATURE_INCOMPAT_FILETYPE)) |
284 | de->file_type = ext2_type_by_mode[(mode & S_IFMT)>>S_SHIFT]; | |
285 | else | |
286 | de->file_type = 0; | |
287 | } | |
288 | ||
289 | static int | |
80886298 | 290 | ext2_readdir(struct file *file, struct dir_context *ctx) |
1da177e4 | 291 | { |
80886298 AV |
292 | loff_t pos = ctx->pos; |
293 | struct inode *inode = file_inode(file); | |
1da177e4 LT |
294 | struct super_block *sb = inode->i_sb; |
295 | unsigned int offset = pos & ~PAGE_CACHE_MASK; | |
296 | unsigned long n = pos >> PAGE_CACHE_SHIFT; | |
297 | unsigned long npages = dir_pages(inode); | |
298 | unsigned chunk_mask = ~(ext2_chunk_size(inode)-1); | |
299 | unsigned char *types = NULL; | |
80886298 | 300 | int need_revalidate = file->f_version != inode->i_version; |
1da177e4 LT |
301 | |
302 | if (pos > inode->i_size - EXT2_DIR_REC_LEN(1)) | |
2d7f2ea9 | 303 | return 0; |
1da177e4 LT |
304 | |
305 | if (EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_FILETYPE)) | |
306 | types = ext2_filetype_table; | |
307 | ||
308 | for ( ; n < npages; n++, offset = 0) { | |
309 | char *kaddr, *limit; | |
310 | ext2_dirent *de; | |
bd39597c | 311 | struct page *page = ext2_get_page(inode, n, 0); |
1da177e4 LT |
312 | |
313 | if (IS_ERR(page)) { | |
605afd60 | 314 | ext2_error(sb, __func__, |
1da177e4 LT |
315 | "bad page in #%lu", |
316 | inode->i_ino); | |
80886298 | 317 | ctx->pos += PAGE_CACHE_SIZE - offset; |
bbff2860 | 318 | return PTR_ERR(page); |
1da177e4 LT |
319 | } |
320 | kaddr = page_address(page); | |
2d7f2ea9 AV |
321 | if (unlikely(need_revalidate)) { |
322 | if (offset) { | |
323 | offset = ext2_validate_entry(kaddr, offset, chunk_mask); | |
80886298 | 324 | ctx->pos = (n<<PAGE_CACHE_SHIFT) + offset; |
2d7f2ea9 | 325 | } |
80886298 | 326 | file->f_version = inode->i_version; |
1da177e4 LT |
327 | need_revalidate = 0; |
328 | } | |
329 | de = (ext2_dirent *)(kaddr+offset); | |
330 | limit = kaddr + ext2_last_byte(inode, n) - EXT2_DIR_REC_LEN(1); | |
331 | for ( ;(char*)de <= limit; de = ext2_next_entry(de)) { | |
332 | if (de->rec_len == 0) { | |
605afd60 | 333 | ext2_error(sb, __func__, |
1da177e4 | 334 | "zero-length directory entry"); |
1da177e4 | 335 | ext2_put_page(page); |
2d7f2ea9 | 336 | return -EIO; |
1da177e4 LT |
337 | } |
338 | if (de->inode) { | |
1da177e4 LT |
339 | unsigned char d_type = DT_UNKNOWN; |
340 | ||
341 | if (types && de->file_type < EXT2_FT_MAX) | |
342 | d_type = types[de->file_type]; | |
343 | ||
80886298 AV |
344 | if (!dir_emit(ctx, de->name, de->name_len, |
345 | le32_to_cpu(de->inode), | |
346 | d_type)) { | |
1da177e4 | 347 | ext2_put_page(page); |
2d7f2ea9 | 348 | return 0; |
1da177e4 LT |
349 | } |
350 | } | |
80886298 | 351 | ctx->pos += ext2_rec_len_from_disk(de->rec_len); |
1da177e4 LT |
352 | } |
353 | ext2_put_page(page); | |
354 | } | |
2d7f2ea9 | 355 | return 0; |
1da177e4 LT |
356 | } |
357 | ||
358 | /* | |
359 | * ext2_find_entry() | |
360 | * | |
361 | * finds an entry in the specified directory with the wanted name. It | |
92e12888 JC |
362 | * returns the page in which the entry was found (as a parameter - res_page), |
363 | * and the entry itself. Page is returned mapped and unlocked. | |
1da177e4 LT |
364 | * Entry is guaranteed to be valid. |
365 | */ | |
a9885444 AV |
366 | struct ext2_dir_entry_2 *ext2_find_entry (struct inode * dir, |
367 | struct qstr *child, struct page ** res_page) | |
1da177e4 | 368 | { |
a9885444 AV |
369 | const char *name = child->name; |
370 | int namelen = child->len; | |
1da177e4 LT |
371 | unsigned reclen = EXT2_DIR_REC_LEN(namelen); |
372 | unsigned long start, n; | |
373 | unsigned long npages = dir_pages(dir); | |
374 | struct page *page = NULL; | |
375 | struct ext2_inode_info *ei = EXT2_I(dir); | |
376 | ext2_dirent * de; | |
bd39597c | 377 | int dir_has_error = 0; |
1da177e4 LT |
378 | |
379 | if (npages == 0) | |
380 | goto out; | |
381 | ||
382 | /* OFFSET_CACHE */ | |
383 | *res_page = NULL; | |
384 | ||
385 | start = ei->i_dir_start_lookup; | |
386 | if (start >= npages) | |
387 | start = 0; | |
388 | n = start; | |
389 | do { | |
390 | char *kaddr; | |
bd39597c | 391 | page = ext2_get_page(dir, n, dir_has_error); |
1da177e4 LT |
392 | if (!IS_ERR(page)) { |
393 | kaddr = page_address(page); | |
394 | de = (ext2_dirent *) kaddr; | |
395 | kaddr += ext2_last_byte(dir, n) - reclen; | |
396 | while ((char *) de <= kaddr) { | |
397 | if (de->rec_len == 0) { | |
605afd60 | 398 | ext2_error(dir->i_sb, __func__, |
1da177e4 LT |
399 | "zero-length directory entry"); |
400 | ext2_put_page(page); | |
401 | goto out; | |
402 | } | |
403 | if (ext2_match (namelen, name, de)) | |
404 | goto found; | |
405 | de = ext2_next_entry(de); | |
406 | } | |
407 | ext2_put_page(page); | |
bd39597c ES |
408 | } else |
409 | dir_has_error = 1; | |
410 | ||
1da177e4 LT |
411 | if (++n >= npages) |
412 | n = 0; | |
d8adb9ce ES |
413 | /* next page is past the blocks we've got */ |
414 | if (unlikely(n > (dir->i_blocks >> (PAGE_CACHE_SHIFT - 9)))) { | |
605afd60 | 415 | ext2_error(dir->i_sb, __func__, |
d8adb9ce ES |
416 | "dir %lu size %lld exceeds block count %llu", |
417 | dir->i_ino, dir->i_size, | |
418 | (unsigned long long)dir->i_blocks); | |
419 | goto out; | |
420 | } | |
1da177e4 LT |
421 | } while (n != start); |
422 | out: | |
423 | return NULL; | |
424 | ||
425 | found: | |
426 | *res_page = page; | |
427 | ei->i_dir_start_lookup = n; | |
428 | return de; | |
429 | } | |
430 | ||
431 | struct ext2_dir_entry_2 * ext2_dotdot (struct inode *dir, struct page **p) | |
432 | { | |
bd39597c | 433 | struct page *page = ext2_get_page(dir, 0, 0); |
1da177e4 LT |
434 | ext2_dirent *de = NULL; |
435 | ||
436 | if (!IS_ERR(page)) { | |
437 | de = ext2_next_entry((ext2_dirent *) page_address(page)); | |
438 | *p = page; | |
439 | } | |
440 | return de; | |
441 | } | |
442 | ||
a9885444 | 443 | ino_t ext2_inode_by_name(struct inode *dir, struct qstr *child) |
1da177e4 LT |
444 | { |
445 | ino_t res = 0; | |
a9885444 | 446 | struct ext2_dir_entry_2 *de; |
1da177e4 LT |
447 | struct page *page; |
448 | ||
a9885444 | 449 | de = ext2_find_entry (dir, child, &page); |
1da177e4 LT |
450 | if (de) { |
451 | res = le32_to_cpu(de->inode); | |
7d93a1a5 | 452 | ext2_put_page(page); |
1da177e4 LT |
453 | } |
454 | return res; | |
455 | } | |
456 | ||
f4e420dc CH |
457 | static int ext2_prepare_chunk(struct page *page, loff_t pos, unsigned len) |
458 | { | |
6e1db88d | 459 | return __block_write_begin(page, pos, len, ext2_get_block); |
f4e420dc CH |
460 | } |
461 | ||
1da177e4 LT |
462 | /* Releases the page */ |
463 | void ext2_set_link(struct inode *dir, struct ext2_dir_entry_2 *de, | |
39fe7557 | 464 | struct page *page, struct inode *inode, int update_times) |
1da177e4 | 465 | { |
f34fb6ec NP |
466 | loff_t pos = page_offset(page) + |
467 | (char *) de - (char *) page_address(page); | |
89910ccc | 468 | unsigned len = ext2_rec_len_from_disk(de->rec_len); |
1da177e4 LT |
469 | int err; |
470 | ||
471 | lock_page(page); | |
f4e420dc | 472 | err = ext2_prepare_chunk(page, pos, len); |
309be53d | 473 | BUG_ON(err); |
1da177e4 | 474 | de->inode = cpu_to_le32(inode->i_ino); |
f34fb6ec NP |
475 | ext2_set_de_type(de, inode); |
476 | err = ext2_commit_chunk(page, pos, len); | |
1da177e4 | 477 | ext2_put_page(page); |
39fe7557 JK |
478 | if (update_times) |
479 | dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC; | |
1da177e4 LT |
480 | EXT2_I(dir)->i_flags &= ~EXT2_BTREE_FL; |
481 | mark_inode_dirty(dir); | |
482 | } | |
483 | ||
484 | /* | |
485 | * Parent is locked. | |
486 | */ | |
487 | int ext2_add_link (struct dentry *dentry, struct inode *inode) | |
488 | { | |
489 | struct inode *dir = dentry->d_parent->d_inode; | |
490 | const char *name = dentry->d_name.name; | |
491 | int namelen = dentry->d_name.len; | |
492 | unsigned chunk_size = ext2_chunk_size(dir); | |
493 | unsigned reclen = EXT2_DIR_REC_LEN(namelen); | |
494 | unsigned short rec_len, name_len; | |
495 | struct page *page = NULL; | |
496 | ext2_dirent * de; | |
497 | unsigned long npages = dir_pages(dir); | |
498 | unsigned long n; | |
499 | char *kaddr; | |
f34fb6ec | 500 | loff_t pos; |
1da177e4 LT |
501 | int err; |
502 | ||
503 | /* | |
504 | * We take care of directory expansion in the same loop. | |
505 | * This code plays outside i_size, so it locks the page | |
506 | * to protect that region. | |
507 | */ | |
508 | for (n = 0; n <= npages; n++) { | |
509 | char *dir_end; | |
510 | ||
bd39597c | 511 | page = ext2_get_page(dir, n, 0); |
1da177e4 LT |
512 | err = PTR_ERR(page); |
513 | if (IS_ERR(page)) | |
514 | goto out; | |
515 | lock_page(page); | |
516 | kaddr = page_address(page); | |
517 | dir_end = kaddr + ext2_last_byte(dir, n); | |
518 | de = (ext2_dirent *)kaddr; | |
519 | kaddr += PAGE_CACHE_SIZE - reclen; | |
520 | while ((char *)de <= kaddr) { | |
521 | if ((char *)de == dir_end) { | |
522 | /* We hit i_size */ | |
523 | name_len = 0; | |
524 | rec_len = chunk_size; | |
89910ccc | 525 | de->rec_len = ext2_rec_len_to_disk(chunk_size); |
1da177e4 LT |
526 | de->inode = 0; |
527 | goto got_it; | |
528 | } | |
529 | if (de->rec_len == 0) { | |
605afd60 | 530 | ext2_error(dir->i_sb, __func__, |
1da177e4 LT |
531 | "zero-length directory entry"); |
532 | err = -EIO; | |
533 | goto out_unlock; | |
534 | } | |
535 | err = -EEXIST; | |
536 | if (ext2_match (namelen, name, de)) | |
537 | goto out_unlock; | |
538 | name_len = EXT2_DIR_REC_LEN(de->name_len); | |
89910ccc | 539 | rec_len = ext2_rec_len_from_disk(de->rec_len); |
1da177e4 LT |
540 | if (!de->inode && rec_len >= reclen) |
541 | goto got_it; | |
542 | if (rec_len >= name_len + reclen) | |
543 | goto got_it; | |
544 | de = (ext2_dirent *) ((char *) de + rec_len); | |
545 | } | |
546 | unlock_page(page); | |
547 | ext2_put_page(page); | |
548 | } | |
549 | BUG(); | |
550 | return -EINVAL; | |
551 | ||
552 | got_it: | |
f34fb6ec NP |
553 | pos = page_offset(page) + |
554 | (char*)de - (char*)page_address(page); | |
f4e420dc | 555 | err = ext2_prepare_chunk(page, pos, rec_len); |
1da177e4 LT |
556 | if (err) |
557 | goto out_unlock; | |
558 | if (de->inode) { | |
559 | ext2_dirent *de1 = (ext2_dirent *) ((char *) de + name_len); | |
89910ccc JK |
560 | de1->rec_len = ext2_rec_len_to_disk(rec_len - name_len); |
561 | de->rec_len = ext2_rec_len_to_disk(name_len); | |
1da177e4 LT |
562 | de = de1; |
563 | } | |
564 | de->name_len = namelen; | |
f34fb6ec | 565 | memcpy(de->name, name, namelen); |
1da177e4 LT |
566 | de->inode = cpu_to_le32(inode->i_ino); |
567 | ext2_set_de_type (de, inode); | |
f34fb6ec | 568 | err = ext2_commit_chunk(page, pos, rec_len); |
1da177e4 LT |
569 | dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC; |
570 | EXT2_I(dir)->i_flags &= ~EXT2_BTREE_FL; | |
571 | mark_inode_dirty(dir); | |
572 | /* OFFSET_CACHE */ | |
573 | out_put: | |
574 | ext2_put_page(page); | |
575 | out: | |
576 | return err; | |
577 | out_unlock: | |
578 | unlock_page(page); | |
579 | goto out_put; | |
580 | } | |
581 | ||
582 | /* | |
583 | * ext2_delete_entry deletes a directory entry by merging it with the | |
584 | * previous entry. Page is up-to-date. Releases the page. | |
585 | */ | |
586 | int ext2_delete_entry (struct ext2_dir_entry_2 * dir, struct page * page ) | |
587 | { | |
f4e420dc | 588 | struct inode *inode = page->mapping->host; |
1da177e4 LT |
589 | char *kaddr = page_address(page); |
590 | unsigned from = ((char*)dir - kaddr) & ~(ext2_chunk_size(inode)-1); | |
89910ccc JK |
591 | unsigned to = ((char *)dir - kaddr) + |
592 | ext2_rec_len_from_disk(dir->rec_len); | |
f34fb6ec | 593 | loff_t pos; |
1da177e4 LT |
594 | ext2_dirent * pde = NULL; |
595 | ext2_dirent * de = (ext2_dirent *) (kaddr + from); | |
596 | int err; | |
597 | ||
598 | while ((char*)de < (char*)dir) { | |
599 | if (de->rec_len == 0) { | |
605afd60 | 600 | ext2_error(inode->i_sb, __func__, |
1da177e4 LT |
601 | "zero-length directory entry"); |
602 | err = -EIO; | |
603 | goto out; | |
604 | } | |
605 | pde = de; | |
606 | de = ext2_next_entry(de); | |
607 | } | |
608 | if (pde) | |
609 | from = (char*)pde - (char*)page_address(page); | |
f34fb6ec | 610 | pos = page_offset(page) + from; |
1da177e4 | 611 | lock_page(page); |
f4e420dc | 612 | err = ext2_prepare_chunk(page, pos, to - from); |
309be53d | 613 | BUG_ON(err); |
1da177e4 | 614 | if (pde) |
89910ccc | 615 | pde->rec_len = ext2_rec_len_to_disk(to - from); |
1da177e4 | 616 | dir->inode = 0; |
f34fb6ec | 617 | err = ext2_commit_chunk(page, pos, to - from); |
1da177e4 LT |
618 | inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC; |
619 | EXT2_I(inode)->i_flags &= ~EXT2_BTREE_FL; | |
620 | mark_inode_dirty(inode); | |
621 | out: | |
622 | ext2_put_page(page); | |
623 | return err; | |
624 | } | |
625 | ||
626 | /* | |
627 | * Set the first fragment of directory. | |
628 | */ | |
629 | int ext2_make_empty(struct inode *inode, struct inode *parent) | |
630 | { | |
f4e420dc | 631 | struct page *page = grab_cache_page(inode->i_mapping, 0); |
1da177e4 LT |
632 | unsigned chunk_size = ext2_chunk_size(inode); |
633 | struct ext2_dir_entry_2 * de; | |
634 | int err; | |
635 | void *kaddr; | |
636 | ||
637 | if (!page) | |
638 | return -ENOMEM; | |
f34fb6ec | 639 | |
f4e420dc | 640 | err = ext2_prepare_chunk(page, 0, chunk_size); |
1da177e4 LT |
641 | if (err) { |
642 | unlock_page(page); | |
643 | goto fail; | |
644 | } | |
d4a23aee | 645 | kaddr = kmap_atomic(page); |
7823c7c1 | 646 | memset(kaddr, 0, chunk_size); |
1da177e4 LT |
647 | de = (struct ext2_dir_entry_2 *)kaddr; |
648 | de->name_len = 1; | |
89910ccc | 649 | de->rec_len = ext2_rec_len_to_disk(EXT2_DIR_REC_LEN(1)); |
1da177e4 LT |
650 | memcpy (de->name, ".\0\0", 4); |
651 | de->inode = cpu_to_le32(inode->i_ino); | |
652 | ext2_set_de_type (de, inode); | |
653 | ||
654 | de = (struct ext2_dir_entry_2 *)(kaddr + EXT2_DIR_REC_LEN(1)); | |
655 | de->name_len = 2; | |
89910ccc | 656 | de->rec_len = ext2_rec_len_to_disk(chunk_size - EXT2_DIR_REC_LEN(1)); |
1da177e4 LT |
657 | de->inode = cpu_to_le32(parent->i_ino); |
658 | memcpy (de->name, "..\0", 4); | |
659 | ext2_set_de_type (de, inode); | |
d4a23aee | 660 | kunmap_atomic(kaddr); |
1da177e4 LT |
661 | err = ext2_commit_chunk(page, 0, chunk_size); |
662 | fail: | |
663 | page_cache_release(page); | |
664 | return err; | |
665 | } | |
666 | ||
667 | /* | |
668 | * routine to check that the specified directory is empty (for rmdir) | |
669 | */ | |
670 | int ext2_empty_dir (struct inode * inode) | |
671 | { | |
672 | struct page *page = NULL; | |
673 | unsigned long i, npages = dir_pages(inode); | |
bd39597c | 674 | int dir_has_error = 0; |
1da177e4 LT |
675 | |
676 | for (i = 0; i < npages; i++) { | |
677 | char *kaddr; | |
678 | ext2_dirent * de; | |
bd39597c | 679 | page = ext2_get_page(inode, i, dir_has_error); |
1da177e4 | 680 | |
bd39597c ES |
681 | if (IS_ERR(page)) { |
682 | dir_has_error = 1; | |
1da177e4 | 683 | continue; |
bd39597c | 684 | } |
1da177e4 LT |
685 | |
686 | kaddr = page_address(page); | |
687 | de = (ext2_dirent *)kaddr; | |
688 | kaddr += ext2_last_byte(inode, i) - EXT2_DIR_REC_LEN(1); | |
689 | ||
690 | while ((char *)de <= kaddr) { | |
691 | if (de->rec_len == 0) { | |
605afd60 | 692 | ext2_error(inode->i_sb, __func__, |
1da177e4 LT |
693 | "zero-length directory entry"); |
694 | printk("kaddr=%p, de=%p\n", kaddr, de); | |
695 | goto not_empty; | |
696 | } | |
697 | if (de->inode != 0) { | |
698 | /* check for . and .. */ | |
699 | if (de->name[0] != '.') | |
700 | goto not_empty; | |
701 | if (de->name_len > 2) | |
702 | goto not_empty; | |
703 | if (de->name_len < 2) { | |
704 | if (de->inode != | |
705 | cpu_to_le32(inode->i_ino)) | |
706 | goto not_empty; | |
707 | } else if (de->name[1] != '.') | |
708 | goto not_empty; | |
709 | } | |
710 | de = ext2_next_entry(de); | |
711 | } | |
712 | ext2_put_page(page); | |
713 | } | |
714 | return 1; | |
715 | ||
716 | not_empty: | |
717 | ext2_put_page(page); | |
718 | return 0; | |
719 | } | |
720 | ||
4b6f5d20 | 721 | const struct file_operations ext2_dir_operations = { |
1da177e4 LT |
722 | .llseek = generic_file_llseek, |
723 | .read = generic_read_dir, | |
80886298 | 724 | .iterate = ext2_readdir, |
14f9f7b2 | 725 | .unlocked_ioctl = ext2_ioctl, |
e322ff07 DH |
726 | #ifdef CONFIG_COMPAT |
727 | .compat_ioctl = ext2_compat_ioctl, | |
728 | #endif | |
48bde86d | 729 | .fsync = ext2_fsync, |
1da177e4 | 730 | }; |