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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 LT |
2 | /* |
3 | * linux/fs/ext2/dir.c | |
4 | * | |
5 | * Copyright (C) 1992, 1993, 1994, 1995 | |
6 | * Remy Card (card@masi.ibp.fr) | |
7 | * Laboratoire MASI - Institut Blaise Pascal | |
8 | * Universite Pierre et Marie Curie (Paris VI) | |
9 | * | |
10 | * from | |
11 | * | |
12 | * linux/fs/minix/dir.c | |
13 | * | |
14 | * Copyright (C) 1991, 1992 Linus Torvalds | |
15 | * | |
16 | * ext2 directory handling functions | |
17 | * | |
18 | * Big-endian to little-endian byte-swapping/bitmaps by | |
19 | * David S. Miller (davem@caip.rutgers.edu), 1995 | |
20 | * | |
21 | * All code that works with directory layout had been switched to pagecache | |
22 | * and moved here. AV | |
23 | */ | |
24 | ||
25 | #include "ext2.h" | |
f34fb6ec | 26 | #include <linux/buffer_head.h> |
1da177e4 | 27 | #include <linux/pagemap.h> |
f34fb6ec | 28 | #include <linux/swap.h> |
1da177e4 LT |
29 | |
30 | typedef struct ext2_dir_entry_2 ext2_dirent; | |
31 | ||
40a063f6 ES |
32 | /* |
33 | * Tests against MAX_REC_LEN etc were put in place for 64k block | |
34 | * sizes; if that is not possible on this arch, we can skip | |
35 | * those tests and speed things up. | |
36 | */ | |
89910ccc JK |
37 | static inline unsigned ext2_rec_len_from_disk(__le16 dlen) |
38 | { | |
39 | unsigned len = le16_to_cpu(dlen); | |
40 | ||
ea1754a0 | 41 | #if (PAGE_SIZE >= 65536) |
89910ccc JK |
42 | if (len == EXT2_MAX_REC_LEN) |
43 | return 1 << 16; | |
40a063f6 | 44 | #endif |
89910ccc JK |
45 | return len; |
46 | } | |
47 | ||
48 | static inline __le16 ext2_rec_len_to_disk(unsigned len) | |
49 | { | |
ea1754a0 | 50 | #if (PAGE_SIZE >= 65536) |
89910ccc JK |
51 | if (len == (1 << 16)) |
52 | return cpu_to_le16(EXT2_MAX_REC_LEN); | |
2c11619a JL |
53 | else |
54 | BUG_ON(len > (1 << 16)); | |
40a063f6 | 55 | #endif |
89910ccc JK |
56 | return cpu_to_le16(len); |
57 | } | |
58 | ||
1da177e4 LT |
59 | /* |
60 | * ext2 uses block-sized chunks. Arguably, sector-sized ones would be | |
61 | * more robust, but we have what we have | |
62 | */ | |
63 | static inline unsigned ext2_chunk_size(struct inode *inode) | |
64 | { | |
65 | return inode->i_sb->s_blocksize; | |
66 | } | |
67 | ||
68 | static inline void ext2_put_page(struct page *page) | |
69 | { | |
70 | kunmap(page); | |
09cbfeaf | 71 | put_page(page); |
1da177e4 LT |
72 | } |
73 | ||
1da177e4 LT |
74 | /* |
75 | * Return the offset into page `page_nr' of the last valid | |
76 | * byte in that page, plus one. | |
77 | */ | |
78 | static unsigned | |
79 | ext2_last_byte(struct inode *inode, unsigned long page_nr) | |
80 | { | |
81 | unsigned last_byte = inode->i_size; | |
82 | ||
09cbfeaf KS |
83 | last_byte -= page_nr << PAGE_SHIFT; |
84 | if (last_byte > PAGE_SIZE) | |
85 | last_byte = PAGE_SIZE; | |
1da177e4 LT |
86 | return last_byte; |
87 | } | |
88 | ||
f34fb6ec | 89 | static int ext2_commit_chunk(struct page *page, loff_t pos, unsigned len) |
1da177e4 | 90 | { |
f34fb6ec NP |
91 | struct address_space *mapping = page->mapping; |
92 | struct inode *dir = mapping->host; | |
1da177e4 | 93 | int err = 0; |
f34fb6ec | 94 | |
1da177e4 | 95 | dir->i_version++; |
f34fb6ec NP |
96 | block_write_end(NULL, mapping, pos, len, len, page, NULL); |
97 | ||
98 | if (pos+len > dir->i_size) { | |
99 | i_size_write(dir, pos+len); | |
100 | mark_inode_dirty(dir); | |
101 | } | |
102 | ||
6b7021ef | 103 | if (IS_DIRSYNC(dir)) { |
2b69c828 | 104 | err = write_one_page(page); |
6b7021ef | 105 | if (!err) |
c3765016 | 106 | err = sync_inode_metadata(dir, 1); |
6b7021ef | 107 | } else { |
1da177e4 | 108 | unlock_page(page); |
6b7021ef | 109 | } |
f34fb6ec | 110 | |
1da177e4 LT |
111 | return err; |
112 | } | |
113 | ||
be5b82db | 114 | static bool ext2_check_page(struct page *page, int quiet) |
1da177e4 LT |
115 | { |
116 | struct inode *dir = page->mapping->host; | |
117 | struct super_block *sb = dir->i_sb; | |
118 | unsigned chunk_size = ext2_chunk_size(dir); | |
119 | char *kaddr = page_address(page); | |
120 | u32 max_inumber = le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count); | |
121 | unsigned offs, rec_len; | |
09cbfeaf | 122 | unsigned limit = PAGE_SIZE; |
1da177e4 LT |
123 | ext2_dirent *p; |
124 | char *error; | |
125 | ||
09cbfeaf KS |
126 | if ((dir->i_size >> PAGE_SHIFT) == page->index) { |
127 | limit = dir->i_size & ~PAGE_MASK; | |
1da177e4 LT |
128 | if (limit & (chunk_size - 1)) |
129 | goto Ebadsize; | |
130 | if (!limit) | |
131 | goto out; | |
132 | } | |
133 | for (offs = 0; offs <= limit - EXT2_DIR_REC_LEN(1); offs += rec_len) { | |
134 | p = (ext2_dirent *)(kaddr + offs); | |
89910ccc | 135 | rec_len = ext2_rec_len_from_disk(p->rec_len); |
1da177e4 | 136 | |
40a063f6 | 137 | if (unlikely(rec_len < EXT2_DIR_REC_LEN(1))) |
1da177e4 | 138 | goto Eshort; |
40a063f6 | 139 | if (unlikely(rec_len & 3)) |
1da177e4 | 140 | goto Ealign; |
40a063f6 | 141 | if (unlikely(rec_len < EXT2_DIR_REC_LEN(p->name_len))) |
1da177e4 | 142 | goto Enamelen; |
40a063f6 | 143 | if (unlikely(((offs + rec_len - 1) ^ offs) & ~(chunk_size-1))) |
1da177e4 | 144 | goto Espan; |
40a063f6 | 145 | if (unlikely(le32_to_cpu(p->inode) > max_inumber)) |
1da177e4 LT |
146 | goto Einumber; |
147 | } | |
148 | if (offs != limit) | |
149 | goto Eend; | |
150 | out: | |
151 | SetPageChecked(page); | |
be5b82db | 152 | return true; |
1da177e4 LT |
153 | |
154 | /* Too bad, we had an error */ | |
155 | ||
156 | Ebadsize: | |
bd39597c ES |
157 | if (!quiet) |
158 | ext2_error(sb, __func__, | |
159 | "size of directory #%lu is not a multiple " | |
160 | "of chunk size", dir->i_ino); | |
1da177e4 LT |
161 | goto fail; |
162 | Eshort: | |
163 | error = "rec_len is smaller than minimal"; | |
164 | goto bad_entry; | |
165 | Ealign: | |
166 | error = "unaligned directory entry"; | |
167 | goto bad_entry; | |
168 | Enamelen: | |
169 | error = "rec_len is too small for name_len"; | |
170 | goto bad_entry; | |
171 | Espan: | |
172 | error = "directory entry across blocks"; | |
173 | goto bad_entry; | |
174 | Einumber: | |
175 | error = "inode out of bounds"; | |
176 | bad_entry: | |
bd39597c ES |
177 | if (!quiet) |
178 | ext2_error(sb, __func__, "bad entry in directory #%lu: : %s - " | |
179 | "offset=%lu, inode=%lu, rec_len=%d, name_len=%d", | |
09cbfeaf | 180 | dir->i_ino, error, (page->index<<PAGE_SHIFT)+offs, |
bd39597c ES |
181 | (unsigned long) le32_to_cpu(p->inode), |
182 | rec_len, p->name_len); | |
1da177e4 LT |
183 | goto fail; |
184 | Eend: | |
bd39597c ES |
185 | if (!quiet) { |
186 | p = (ext2_dirent *)(kaddr + offs); | |
187 | ext2_error(sb, "ext2_check_page", | |
188 | "entry in directory #%lu spans the page boundary" | |
189 | "offset=%lu, inode=%lu", | |
09cbfeaf | 190 | dir->i_ino, (page->index<<PAGE_SHIFT)+offs, |
bd39597c ES |
191 | (unsigned long) le32_to_cpu(p->inode)); |
192 | } | |
1da177e4 | 193 | fail: |
1da177e4 | 194 | SetPageError(page); |
be5b82db | 195 | return false; |
1da177e4 LT |
196 | } |
197 | ||
bd39597c ES |
198 | static struct page * ext2_get_page(struct inode *dir, unsigned long n, |
199 | int quiet) | |
1da177e4 LT |
200 | { |
201 | struct address_space *mapping = dir->i_mapping; | |
090d2b18 | 202 | struct page *page = read_mapping_page(mapping, n, NULL); |
1da177e4 | 203 | if (!IS_ERR(page)) { |
1da177e4 | 204 | kmap(page); |
be5b82db AV |
205 | if (unlikely(!PageChecked(page))) { |
206 | if (PageError(page) || !ext2_check_page(page, quiet)) | |
207 | goto fail; | |
208 | } | |
1da177e4 LT |
209 | } |
210 | return page; | |
211 | ||
212 | fail: | |
213 | ext2_put_page(page); | |
214 | return ERR_PTR(-EIO); | |
215 | } | |
216 | ||
217 | /* | |
218 | * NOTE! unlike strncmp, ext2_match returns 1 for success, 0 for failure. | |
219 | * | |
220 | * len <= EXT2_NAME_LEN and de != NULL are guaranteed by caller. | |
221 | */ | |
222 | static inline int ext2_match (int len, const char * const name, | |
223 | struct ext2_dir_entry_2 * de) | |
224 | { | |
225 | if (len != de->name_len) | |
226 | return 0; | |
227 | if (!de->inode) | |
228 | return 0; | |
229 | return !memcmp(name, de->name, len); | |
230 | } | |
231 | ||
232 | /* | |
233 | * p is at least 6 bytes before the end of page | |
234 | */ | |
235 | static inline ext2_dirent *ext2_next_entry(ext2_dirent *p) | |
236 | { | |
89910ccc JK |
237 | return (ext2_dirent *)((char *)p + |
238 | ext2_rec_len_from_disk(p->rec_len)); | |
1da177e4 LT |
239 | } |
240 | ||
241 | static inline unsigned | |
242 | ext2_validate_entry(char *base, unsigned offset, unsigned mask) | |
243 | { | |
244 | ext2_dirent *de = (ext2_dirent*)(base + offset); | |
245 | ext2_dirent *p = (ext2_dirent*)(base + (offset&mask)); | |
246 | while ((char*)p < (char*)de) { | |
247 | if (p->rec_len == 0) | |
248 | break; | |
249 | p = ext2_next_entry(p); | |
250 | } | |
251 | return (char *)p - base; | |
252 | } | |
253 | ||
254 | static unsigned char ext2_filetype_table[EXT2_FT_MAX] = { | |
255 | [EXT2_FT_UNKNOWN] = DT_UNKNOWN, | |
256 | [EXT2_FT_REG_FILE] = DT_REG, | |
257 | [EXT2_FT_DIR] = DT_DIR, | |
258 | [EXT2_FT_CHRDEV] = DT_CHR, | |
259 | [EXT2_FT_BLKDEV] = DT_BLK, | |
260 | [EXT2_FT_FIFO] = DT_FIFO, | |
261 | [EXT2_FT_SOCK] = DT_SOCK, | |
262 | [EXT2_FT_SYMLINK] = DT_LNK, | |
263 | }; | |
264 | ||
265 | #define S_SHIFT 12 | |
266 | static unsigned char ext2_type_by_mode[S_IFMT >> S_SHIFT] = { | |
267 | [S_IFREG >> S_SHIFT] = EXT2_FT_REG_FILE, | |
268 | [S_IFDIR >> S_SHIFT] = EXT2_FT_DIR, | |
269 | [S_IFCHR >> S_SHIFT] = EXT2_FT_CHRDEV, | |
270 | [S_IFBLK >> S_SHIFT] = EXT2_FT_BLKDEV, | |
271 | [S_IFIFO >> S_SHIFT] = EXT2_FT_FIFO, | |
272 | [S_IFSOCK >> S_SHIFT] = EXT2_FT_SOCK, | |
273 | [S_IFLNK >> S_SHIFT] = EXT2_FT_SYMLINK, | |
274 | }; | |
275 | ||
276 | static inline void ext2_set_de_type(ext2_dirent *de, struct inode *inode) | |
277 | { | |
3ea40bc9 | 278 | umode_t mode = inode->i_mode; |
1da177e4 LT |
279 | if (EXT2_HAS_INCOMPAT_FEATURE(inode->i_sb, EXT2_FEATURE_INCOMPAT_FILETYPE)) |
280 | de->file_type = ext2_type_by_mode[(mode & S_IFMT)>>S_SHIFT]; | |
281 | else | |
282 | de->file_type = 0; | |
283 | } | |
284 | ||
285 | static int | |
80886298 | 286 | ext2_readdir(struct file *file, struct dir_context *ctx) |
1da177e4 | 287 | { |
80886298 AV |
288 | loff_t pos = ctx->pos; |
289 | struct inode *inode = file_inode(file); | |
1da177e4 | 290 | struct super_block *sb = inode->i_sb; |
09cbfeaf KS |
291 | unsigned int offset = pos & ~PAGE_MASK; |
292 | unsigned long n = pos >> PAGE_SHIFT; | |
1da177e4 LT |
293 | unsigned long npages = dir_pages(inode); |
294 | unsigned chunk_mask = ~(ext2_chunk_size(inode)-1); | |
295 | unsigned char *types = NULL; | |
80886298 | 296 | int need_revalidate = file->f_version != inode->i_version; |
1da177e4 LT |
297 | |
298 | if (pos > inode->i_size - EXT2_DIR_REC_LEN(1)) | |
2d7f2ea9 | 299 | return 0; |
1da177e4 LT |
300 | |
301 | if (EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_FILETYPE)) | |
302 | types = ext2_filetype_table; | |
303 | ||
304 | for ( ; n < npages; n++, offset = 0) { | |
305 | char *kaddr, *limit; | |
306 | ext2_dirent *de; | |
bd39597c | 307 | struct page *page = ext2_get_page(inode, n, 0); |
1da177e4 LT |
308 | |
309 | if (IS_ERR(page)) { | |
605afd60 | 310 | ext2_error(sb, __func__, |
1da177e4 LT |
311 | "bad page in #%lu", |
312 | inode->i_ino); | |
09cbfeaf | 313 | ctx->pos += PAGE_SIZE - offset; |
bbff2860 | 314 | return PTR_ERR(page); |
1da177e4 LT |
315 | } |
316 | kaddr = page_address(page); | |
2d7f2ea9 AV |
317 | if (unlikely(need_revalidate)) { |
318 | if (offset) { | |
319 | offset = ext2_validate_entry(kaddr, offset, chunk_mask); | |
09cbfeaf | 320 | ctx->pos = (n<<PAGE_SHIFT) + offset; |
2d7f2ea9 | 321 | } |
80886298 | 322 | file->f_version = inode->i_version; |
1da177e4 LT |
323 | need_revalidate = 0; |
324 | } | |
325 | de = (ext2_dirent *)(kaddr+offset); | |
326 | limit = kaddr + ext2_last_byte(inode, n) - EXT2_DIR_REC_LEN(1); | |
327 | for ( ;(char*)de <= limit; de = ext2_next_entry(de)) { | |
328 | if (de->rec_len == 0) { | |
605afd60 | 329 | ext2_error(sb, __func__, |
1da177e4 | 330 | "zero-length directory entry"); |
1da177e4 | 331 | ext2_put_page(page); |
2d7f2ea9 | 332 | return -EIO; |
1da177e4 LT |
333 | } |
334 | if (de->inode) { | |
1da177e4 LT |
335 | unsigned char d_type = DT_UNKNOWN; |
336 | ||
337 | if (types && de->file_type < EXT2_FT_MAX) | |
338 | d_type = types[de->file_type]; | |
339 | ||
80886298 AV |
340 | if (!dir_emit(ctx, de->name, de->name_len, |
341 | le32_to_cpu(de->inode), | |
342 | d_type)) { | |
1da177e4 | 343 | ext2_put_page(page); |
2d7f2ea9 | 344 | return 0; |
1da177e4 LT |
345 | } |
346 | } | |
80886298 | 347 | ctx->pos += ext2_rec_len_from_disk(de->rec_len); |
1da177e4 LT |
348 | } |
349 | ext2_put_page(page); | |
350 | } | |
2d7f2ea9 | 351 | return 0; |
1da177e4 LT |
352 | } |
353 | ||
354 | /* | |
355 | * ext2_find_entry() | |
356 | * | |
357 | * finds an entry in the specified directory with the wanted name. It | |
92e12888 JC |
358 | * returns the page in which the entry was found (as a parameter - res_page), |
359 | * and the entry itself. Page is returned mapped and unlocked. | |
1da177e4 LT |
360 | * Entry is guaranteed to be valid. |
361 | */ | |
ac3ba644 AV |
362 | struct ext2_dir_entry_2 *ext2_find_entry (struct inode *dir, |
363 | const struct qstr *child, struct page **res_page) | |
1da177e4 | 364 | { |
a9885444 AV |
365 | const char *name = child->name; |
366 | int namelen = child->len; | |
1da177e4 LT |
367 | unsigned reclen = EXT2_DIR_REC_LEN(namelen); |
368 | unsigned long start, n; | |
369 | unsigned long npages = dir_pages(dir); | |
370 | struct page *page = NULL; | |
371 | struct ext2_inode_info *ei = EXT2_I(dir); | |
372 | ext2_dirent * de; | |
bd39597c | 373 | int dir_has_error = 0; |
1da177e4 LT |
374 | |
375 | if (npages == 0) | |
376 | goto out; | |
377 | ||
378 | /* OFFSET_CACHE */ | |
379 | *res_page = NULL; | |
380 | ||
381 | start = ei->i_dir_start_lookup; | |
382 | if (start >= npages) | |
383 | start = 0; | |
384 | n = start; | |
385 | do { | |
386 | char *kaddr; | |
bd39597c | 387 | page = ext2_get_page(dir, n, dir_has_error); |
1da177e4 LT |
388 | if (!IS_ERR(page)) { |
389 | kaddr = page_address(page); | |
390 | de = (ext2_dirent *) kaddr; | |
391 | kaddr += ext2_last_byte(dir, n) - reclen; | |
392 | while ((char *) de <= kaddr) { | |
393 | if (de->rec_len == 0) { | |
605afd60 | 394 | ext2_error(dir->i_sb, __func__, |
1da177e4 LT |
395 | "zero-length directory entry"); |
396 | ext2_put_page(page); | |
397 | goto out; | |
398 | } | |
399 | if (ext2_match (namelen, name, de)) | |
400 | goto found; | |
401 | de = ext2_next_entry(de); | |
402 | } | |
403 | ext2_put_page(page); | |
bd39597c ES |
404 | } else |
405 | dir_has_error = 1; | |
406 | ||
1da177e4 LT |
407 | if (++n >= npages) |
408 | n = 0; | |
d8adb9ce | 409 | /* next page is past the blocks we've got */ |
09cbfeaf | 410 | if (unlikely(n > (dir->i_blocks >> (PAGE_SHIFT - 9)))) { |
605afd60 | 411 | ext2_error(dir->i_sb, __func__, |
d8adb9ce ES |
412 | "dir %lu size %lld exceeds block count %llu", |
413 | dir->i_ino, dir->i_size, | |
414 | (unsigned long long)dir->i_blocks); | |
415 | goto out; | |
416 | } | |
1da177e4 LT |
417 | } while (n != start); |
418 | out: | |
419 | return NULL; | |
420 | ||
421 | found: | |
422 | *res_page = page; | |
423 | ei->i_dir_start_lookup = n; | |
424 | return de; | |
425 | } | |
426 | ||
427 | struct ext2_dir_entry_2 * ext2_dotdot (struct inode *dir, struct page **p) | |
428 | { | |
bd39597c | 429 | struct page *page = ext2_get_page(dir, 0, 0); |
1da177e4 LT |
430 | ext2_dirent *de = NULL; |
431 | ||
432 | if (!IS_ERR(page)) { | |
433 | de = ext2_next_entry((ext2_dirent *) page_address(page)); | |
434 | *p = page; | |
435 | } | |
436 | return de; | |
437 | } | |
438 | ||
ac3ba644 | 439 | ino_t ext2_inode_by_name(struct inode *dir, const struct qstr *child) |
1da177e4 LT |
440 | { |
441 | ino_t res = 0; | |
a9885444 | 442 | struct ext2_dir_entry_2 *de; |
1da177e4 LT |
443 | struct page *page; |
444 | ||
a9885444 | 445 | de = ext2_find_entry (dir, child, &page); |
1da177e4 LT |
446 | if (de) { |
447 | res = le32_to_cpu(de->inode); | |
7d93a1a5 | 448 | ext2_put_page(page); |
1da177e4 LT |
449 | } |
450 | return res; | |
451 | } | |
452 | ||
f4e420dc CH |
453 | static int ext2_prepare_chunk(struct page *page, loff_t pos, unsigned len) |
454 | { | |
6e1db88d | 455 | return __block_write_begin(page, pos, len, ext2_get_block); |
f4e420dc CH |
456 | } |
457 | ||
1da177e4 LT |
458 | /* Releases the page */ |
459 | void ext2_set_link(struct inode *dir, struct ext2_dir_entry_2 *de, | |
39fe7557 | 460 | struct page *page, struct inode *inode, int update_times) |
1da177e4 | 461 | { |
f34fb6ec NP |
462 | loff_t pos = page_offset(page) + |
463 | (char *) de - (char *) page_address(page); | |
89910ccc | 464 | unsigned len = ext2_rec_len_from_disk(de->rec_len); |
1da177e4 LT |
465 | int err; |
466 | ||
467 | lock_page(page); | |
f4e420dc | 468 | err = ext2_prepare_chunk(page, pos, len); |
309be53d | 469 | BUG_ON(err); |
1da177e4 | 470 | de->inode = cpu_to_le32(inode->i_ino); |
f34fb6ec NP |
471 | ext2_set_de_type(de, inode); |
472 | err = ext2_commit_chunk(page, pos, len); | |
1da177e4 | 473 | ext2_put_page(page); |
39fe7557 | 474 | if (update_times) |
02027d42 | 475 | dir->i_mtime = dir->i_ctime = current_time(dir); |
1da177e4 LT |
476 | EXT2_I(dir)->i_flags &= ~EXT2_BTREE_FL; |
477 | mark_inode_dirty(dir); | |
478 | } | |
479 | ||
480 | /* | |
481 | * Parent is locked. | |
482 | */ | |
483 | int ext2_add_link (struct dentry *dentry, struct inode *inode) | |
484 | { | |
2b0143b5 | 485 | struct inode *dir = d_inode(dentry->d_parent); |
1da177e4 LT |
486 | const char *name = dentry->d_name.name; |
487 | int namelen = dentry->d_name.len; | |
488 | unsigned chunk_size = ext2_chunk_size(dir); | |
489 | unsigned reclen = EXT2_DIR_REC_LEN(namelen); | |
490 | unsigned short rec_len, name_len; | |
491 | struct page *page = NULL; | |
492 | ext2_dirent * de; | |
493 | unsigned long npages = dir_pages(dir); | |
494 | unsigned long n; | |
495 | char *kaddr; | |
f34fb6ec | 496 | loff_t pos; |
1da177e4 LT |
497 | int err; |
498 | ||
499 | /* | |
500 | * We take care of directory expansion in the same loop. | |
501 | * This code plays outside i_size, so it locks the page | |
502 | * to protect that region. | |
503 | */ | |
504 | for (n = 0; n <= npages; n++) { | |
505 | char *dir_end; | |
506 | ||
bd39597c | 507 | page = ext2_get_page(dir, n, 0); |
1da177e4 LT |
508 | err = PTR_ERR(page); |
509 | if (IS_ERR(page)) | |
510 | goto out; | |
511 | lock_page(page); | |
512 | kaddr = page_address(page); | |
513 | dir_end = kaddr + ext2_last_byte(dir, n); | |
514 | de = (ext2_dirent *)kaddr; | |
09cbfeaf | 515 | kaddr += PAGE_SIZE - reclen; |
1da177e4 LT |
516 | while ((char *)de <= kaddr) { |
517 | if ((char *)de == dir_end) { | |
518 | /* We hit i_size */ | |
519 | name_len = 0; | |
520 | rec_len = chunk_size; | |
89910ccc | 521 | de->rec_len = ext2_rec_len_to_disk(chunk_size); |
1da177e4 LT |
522 | de->inode = 0; |
523 | goto got_it; | |
524 | } | |
525 | if (de->rec_len == 0) { | |
605afd60 | 526 | ext2_error(dir->i_sb, __func__, |
1da177e4 LT |
527 | "zero-length directory entry"); |
528 | err = -EIO; | |
529 | goto out_unlock; | |
530 | } | |
531 | err = -EEXIST; | |
532 | if (ext2_match (namelen, name, de)) | |
533 | goto out_unlock; | |
534 | name_len = EXT2_DIR_REC_LEN(de->name_len); | |
89910ccc | 535 | rec_len = ext2_rec_len_from_disk(de->rec_len); |
1da177e4 LT |
536 | if (!de->inode && rec_len >= reclen) |
537 | goto got_it; | |
538 | if (rec_len >= name_len + reclen) | |
539 | goto got_it; | |
540 | de = (ext2_dirent *) ((char *) de + rec_len); | |
541 | } | |
542 | unlock_page(page); | |
543 | ext2_put_page(page); | |
544 | } | |
545 | BUG(); | |
546 | return -EINVAL; | |
547 | ||
548 | got_it: | |
f34fb6ec NP |
549 | pos = page_offset(page) + |
550 | (char*)de - (char*)page_address(page); | |
f4e420dc | 551 | err = ext2_prepare_chunk(page, pos, rec_len); |
1da177e4 LT |
552 | if (err) |
553 | goto out_unlock; | |
554 | if (de->inode) { | |
555 | ext2_dirent *de1 = (ext2_dirent *) ((char *) de + name_len); | |
89910ccc JK |
556 | de1->rec_len = ext2_rec_len_to_disk(rec_len - name_len); |
557 | de->rec_len = ext2_rec_len_to_disk(name_len); | |
1da177e4 LT |
558 | de = de1; |
559 | } | |
560 | de->name_len = namelen; | |
f34fb6ec | 561 | memcpy(de->name, name, namelen); |
1da177e4 LT |
562 | de->inode = cpu_to_le32(inode->i_ino); |
563 | ext2_set_de_type (de, inode); | |
f34fb6ec | 564 | err = ext2_commit_chunk(page, pos, rec_len); |
02027d42 | 565 | dir->i_mtime = dir->i_ctime = current_time(dir); |
1da177e4 LT |
566 | EXT2_I(dir)->i_flags &= ~EXT2_BTREE_FL; |
567 | mark_inode_dirty(dir); | |
568 | /* OFFSET_CACHE */ | |
569 | out_put: | |
570 | ext2_put_page(page); | |
571 | out: | |
572 | return err; | |
573 | out_unlock: | |
574 | unlock_page(page); | |
575 | goto out_put; | |
576 | } | |
577 | ||
578 | /* | |
579 | * ext2_delete_entry deletes a directory entry by merging it with the | |
580 | * previous entry. Page is up-to-date. Releases the page. | |
581 | */ | |
582 | int ext2_delete_entry (struct ext2_dir_entry_2 * dir, struct page * page ) | |
583 | { | |
f4e420dc | 584 | struct inode *inode = page->mapping->host; |
1da177e4 LT |
585 | char *kaddr = page_address(page); |
586 | unsigned from = ((char*)dir - kaddr) & ~(ext2_chunk_size(inode)-1); | |
89910ccc JK |
587 | unsigned to = ((char *)dir - kaddr) + |
588 | ext2_rec_len_from_disk(dir->rec_len); | |
f34fb6ec | 589 | loff_t pos; |
1da177e4 LT |
590 | ext2_dirent * pde = NULL; |
591 | ext2_dirent * de = (ext2_dirent *) (kaddr + from); | |
592 | int err; | |
593 | ||
594 | while ((char*)de < (char*)dir) { | |
595 | if (de->rec_len == 0) { | |
605afd60 | 596 | ext2_error(inode->i_sb, __func__, |
1da177e4 LT |
597 | "zero-length directory entry"); |
598 | err = -EIO; | |
599 | goto out; | |
600 | } | |
601 | pde = de; | |
602 | de = ext2_next_entry(de); | |
603 | } | |
604 | if (pde) | |
605 | from = (char*)pde - (char*)page_address(page); | |
f34fb6ec | 606 | pos = page_offset(page) + from; |
1da177e4 | 607 | lock_page(page); |
f4e420dc | 608 | err = ext2_prepare_chunk(page, pos, to - from); |
309be53d | 609 | BUG_ON(err); |
1da177e4 | 610 | if (pde) |
89910ccc | 611 | pde->rec_len = ext2_rec_len_to_disk(to - from); |
1da177e4 | 612 | dir->inode = 0; |
f34fb6ec | 613 | err = ext2_commit_chunk(page, pos, to - from); |
02027d42 | 614 | inode->i_ctime = inode->i_mtime = current_time(inode); |
1da177e4 LT |
615 | EXT2_I(inode)->i_flags &= ~EXT2_BTREE_FL; |
616 | mark_inode_dirty(inode); | |
617 | out: | |
618 | ext2_put_page(page); | |
619 | return err; | |
620 | } | |
621 | ||
622 | /* | |
623 | * Set the first fragment of directory. | |
624 | */ | |
625 | int ext2_make_empty(struct inode *inode, struct inode *parent) | |
626 | { | |
f4e420dc | 627 | struct page *page = grab_cache_page(inode->i_mapping, 0); |
1da177e4 LT |
628 | unsigned chunk_size = ext2_chunk_size(inode); |
629 | struct ext2_dir_entry_2 * de; | |
630 | int err; | |
631 | void *kaddr; | |
632 | ||
633 | if (!page) | |
634 | return -ENOMEM; | |
f34fb6ec | 635 | |
f4e420dc | 636 | err = ext2_prepare_chunk(page, 0, chunk_size); |
1da177e4 LT |
637 | if (err) { |
638 | unlock_page(page); | |
639 | goto fail; | |
640 | } | |
d4a23aee | 641 | kaddr = kmap_atomic(page); |
7823c7c1 | 642 | memset(kaddr, 0, chunk_size); |
1da177e4 LT |
643 | de = (struct ext2_dir_entry_2 *)kaddr; |
644 | de->name_len = 1; | |
89910ccc | 645 | de->rec_len = ext2_rec_len_to_disk(EXT2_DIR_REC_LEN(1)); |
1da177e4 LT |
646 | memcpy (de->name, ".\0\0", 4); |
647 | de->inode = cpu_to_le32(inode->i_ino); | |
648 | ext2_set_de_type (de, inode); | |
649 | ||
650 | de = (struct ext2_dir_entry_2 *)(kaddr + EXT2_DIR_REC_LEN(1)); | |
651 | de->name_len = 2; | |
89910ccc | 652 | de->rec_len = ext2_rec_len_to_disk(chunk_size - EXT2_DIR_REC_LEN(1)); |
1da177e4 LT |
653 | de->inode = cpu_to_le32(parent->i_ino); |
654 | memcpy (de->name, "..\0", 4); | |
655 | ext2_set_de_type (de, inode); | |
d4a23aee | 656 | kunmap_atomic(kaddr); |
1da177e4 LT |
657 | err = ext2_commit_chunk(page, 0, chunk_size); |
658 | fail: | |
09cbfeaf | 659 | put_page(page); |
1da177e4 LT |
660 | return err; |
661 | } | |
662 | ||
663 | /* | |
664 | * routine to check that the specified directory is empty (for rmdir) | |
665 | */ | |
666 | int ext2_empty_dir (struct inode * inode) | |
667 | { | |
668 | struct page *page = NULL; | |
669 | unsigned long i, npages = dir_pages(inode); | |
bd39597c | 670 | int dir_has_error = 0; |
1da177e4 LT |
671 | |
672 | for (i = 0; i < npages; i++) { | |
673 | char *kaddr; | |
674 | ext2_dirent * de; | |
bd39597c | 675 | page = ext2_get_page(inode, i, dir_has_error); |
1da177e4 | 676 | |
bd39597c ES |
677 | if (IS_ERR(page)) { |
678 | dir_has_error = 1; | |
1da177e4 | 679 | continue; |
bd39597c | 680 | } |
1da177e4 LT |
681 | |
682 | kaddr = page_address(page); | |
683 | de = (ext2_dirent *)kaddr; | |
684 | kaddr += ext2_last_byte(inode, i) - EXT2_DIR_REC_LEN(1); | |
685 | ||
686 | while ((char *)de <= kaddr) { | |
687 | if (de->rec_len == 0) { | |
605afd60 | 688 | ext2_error(inode->i_sb, __func__, |
1da177e4 LT |
689 | "zero-length directory entry"); |
690 | printk("kaddr=%p, de=%p\n", kaddr, de); | |
691 | goto not_empty; | |
692 | } | |
693 | if (de->inode != 0) { | |
694 | /* check for . and .. */ | |
695 | if (de->name[0] != '.') | |
696 | goto not_empty; | |
697 | if (de->name_len > 2) | |
698 | goto not_empty; | |
699 | if (de->name_len < 2) { | |
700 | if (de->inode != | |
701 | cpu_to_le32(inode->i_ino)) | |
702 | goto not_empty; | |
703 | } else if (de->name[1] != '.') | |
704 | goto not_empty; | |
705 | } | |
706 | de = ext2_next_entry(de); | |
707 | } | |
708 | ext2_put_page(page); | |
709 | } | |
710 | return 1; | |
711 | ||
712 | not_empty: | |
713 | ext2_put_page(page); | |
714 | return 0; | |
715 | } | |
716 | ||
4b6f5d20 | 717 | const struct file_operations ext2_dir_operations = { |
1da177e4 LT |
718 | .llseek = generic_file_llseek, |
719 | .read = generic_read_dir, | |
3b0a3c1a | 720 | .iterate_shared = ext2_readdir, |
14f9f7b2 | 721 | .unlocked_ioctl = ext2_ioctl, |
e322ff07 DH |
722 | #ifdef CONFIG_COMPAT |
723 | .compat_ioctl = ext2_compat_ioctl, | |
724 | #endif | |
48bde86d | 725 | .fsync = ext2_fsync, |
1da177e4 | 726 | }; |