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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> |
e1d747d9 | 29 | #include <linux/iversion.h> |
1da177e4 LT |
30 | |
31 | typedef struct ext2_dir_entry_2 ext2_dirent; | |
32 | ||
40a063f6 ES |
33 | /* |
34 | * Tests against MAX_REC_LEN etc were put in place for 64k block | |
35 | * sizes; if that is not possible on this arch, we can skip | |
36 | * those tests and speed things up. | |
37 | */ | |
89910ccc JK |
38 | static inline unsigned ext2_rec_len_from_disk(__le16 dlen) |
39 | { | |
40 | unsigned len = le16_to_cpu(dlen); | |
41 | ||
ea1754a0 | 42 | #if (PAGE_SIZE >= 65536) |
89910ccc JK |
43 | if (len == EXT2_MAX_REC_LEN) |
44 | return 1 << 16; | |
40a063f6 | 45 | #endif |
89910ccc JK |
46 | return len; |
47 | } | |
48 | ||
49 | static inline __le16 ext2_rec_len_to_disk(unsigned len) | |
50 | { | |
ea1754a0 | 51 | #if (PAGE_SIZE >= 65536) |
89910ccc JK |
52 | if (len == (1 << 16)) |
53 | return cpu_to_le16(EXT2_MAX_REC_LEN); | |
2c11619a JL |
54 | else |
55 | BUG_ON(len > (1 << 16)); | |
40a063f6 | 56 | #endif |
89910ccc JK |
57 | return cpu_to_le16(len); |
58 | } | |
59 | ||
1da177e4 LT |
60 | /* |
61 | * ext2 uses block-sized chunks. Arguably, sector-sized ones would be | |
62 | * more robust, but we have what we have | |
63 | */ | |
64 | static inline unsigned ext2_chunk_size(struct inode *inode) | |
65 | { | |
66 | return inode->i_sb->s_blocksize; | |
67 | } | |
68 | ||
1da177e4 LT |
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 | ||
09cbfeaf KS |
78 | last_byte -= page_nr << PAGE_SHIFT; |
79 | if (last_byte > PAGE_SIZE) | |
80 | last_byte = PAGE_SIZE; | |
1da177e4 LT |
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 | |
e1d747d9 | 90 | inode_inc_iversion(dir); |
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 | ||
6b7021ef | 98 | if (IS_DIRSYNC(dir)) { |
2b69c828 | 99 | err = write_one_page(page); |
6b7021ef | 100 | if (!err) |
c3765016 | 101 | err = sync_inode_metadata(dir, 1); |
6b7021ef | 102 | } else { |
1da177e4 | 103 | unlock_page(page); |
6b7021ef | 104 | } |
f34fb6ec | 105 | |
1da177e4 LT |
106 | return err; |
107 | } | |
108 | ||
728d392f | 109 | static bool ext2_check_page(struct page *page, int quiet, char *kaddr) |
1da177e4 LT |
110 | { |
111 | struct inode *dir = page->mapping->host; | |
112 | struct super_block *sb = dir->i_sb; | |
113 | unsigned chunk_size = ext2_chunk_size(dir); | |
1da177e4 LT |
114 | u32 max_inumber = le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count); |
115 | unsigned offs, rec_len; | |
09cbfeaf | 116 | unsigned limit = PAGE_SIZE; |
1da177e4 LT |
117 | ext2_dirent *p; |
118 | char *error; | |
119 | ||
09cbfeaf KS |
120 | if ((dir->i_size >> PAGE_SHIFT) == page->index) { |
121 | limit = dir->i_size & ~PAGE_MASK; | |
1da177e4 LT |
122 | if (limit & (chunk_size - 1)) |
123 | goto Ebadsize; | |
124 | if (!limit) | |
125 | goto out; | |
126 | } | |
127 | for (offs = 0; offs <= limit - EXT2_DIR_REC_LEN(1); offs += rec_len) { | |
128 | p = (ext2_dirent *)(kaddr + offs); | |
89910ccc | 129 | rec_len = ext2_rec_len_from_disk(p->rec_len); |
1da177e4 | 130 | |
40a063f6 | 131 | if (unlikely(rec_len < EXT2_DIR_REC_LEN(1))) |
1da177e4 | 132 | goto Eshort; |
40a063f6 | 133 | if (unlikely(rec_len & 3)) |
1da177e4 | 134 | goto Ealign; |
40a063f6 | 135 | if (unlikely(rec_len < EXT2_DIR_REC_LEN(p->name_len))) |
1da177e4 | 136 | goto Enamelen; |
40a063f6 | 137 | if (unlikely(((offs + rec_len - 1) ^ offs) & ~(chunk_size-1))) |
1da177e4 | 138 | goto Espan; |
40a063f6 | 139 | if (unlikely(le32_to_cpu(p->inode) > max_inumber)) |
1da177e4 LT |
140 | goto Einumber; |
141 | } | |
142 | if (offs != limit) | |
143 | goto Eend; | |
144 | out: | |
145 | SetPageChecked(page); | |
be5b82db | 146 | return true; |
1da177e4 LT |
147 | |
148 | /* Too bad, we had an error */ | |
149 | ||
150 | Ebadsize: | |
bd39597c ES |
151 | if (!quiet) |
152 | ext2_error(sb, __func__, | |
153 | "size of directory #%lu is not a multiple " | |
154 | "of chunk size", dir->i_ino); | |
1da177e4 LT |
155 | goto fail; |
156 | Eshort: | |
157 | error = "rec_len is smaller than minimal"; | |
158 | goto bad_entry; | |
159 | Ealign: | |
160 | error = "unaligned directory entry"; | |
161 | goto bad_entry; | |
162 | Enamelen: | |
163 | error = "rec_len is too small for name_len"; | |
164 | goto bad_entry; | |
165 | Espan: | |
166 | error = "directory entry across blocks"; | |
167 | goto bad_entry; | |
168 | Einumber: | |
169 | error = "inode out of bounds"; | |
170 | bad_entry: | |
bd39597c ES |
171 | if (!quiet) |
172 | ext2_error(sb, __func__, "bad entry in directory #%lu: : %s - " | |
173 | "offset=%lu, inode=%lu, rec_len=%d, name_len=%d", | |
09cbfeaf | 174 | dir->i_ino, error, (page->index<<PAGE_SHIFT)+offs, |
bd39597c ES |
175 | (unsigned long) le32_to_cpu(p->inode), |
176 | rec_len, p->name_len); | |
1da177e4 LT |
177 | goto fail; |
178 | Eend: | |
bd39597c ES |
179 | if (!quiet) { |
180 | p = (ext2_dirent *)(kaddr + offs); | |
181 | ext2_error(sb, "ext2_check_page", | |
182 | "entry in directory #%lu spans the page boundary" | |
183 | "offset=%lu, inode=%lu", | |
09cbfeaf | 184 | dir->i_ino, (page->index<<PAGE_SHIFT)+offs, |
bd39597c ES |
185 | (unsigned long) le32_to_cpu(p->inode)); |
186 | } | |
1da177e4 | 187 | fail: |
1da177e4 | 188 | SetPageError(page); |
be5b82db | 189 | return false; |
1da177e4 LT |
190 | } |
191 | ||
782b76d7 IW |
192 | /* |
193 | * Calls to ext2_get_page()/ext2_put_page() must be nested according to the | |
194 | * rules documented in kmap_local_page()/kunmap_local(). | |
195 | * | |
196 | * NOTE: ext2_find_entry() and ext2_dotdot() act as a call to ext2_get_page() | |
197 | * and should be treated as a call to ext2_get_page() for nesting purposes. | |
198 | */ | |
bd39597c | 199 | static struct page * ext2_get_page(struct inode *dir, unsigned long n, |
782b76d7 | 200 | int quiet, void **page_addr) |
1da177e4 LT |
201 | { |
202 | struct address_space *mapping = dir->i_mapping; | |
37ce0b31 MWO |
203 | struct folio *folio = read_mapping_folio(mapping, n, NULL); |
204 | ||
205 | if (IS_ERR(folio)) | |
206 | return &folio->page; | |
207 | *page_addr = kmap_local_folio(folio, n & (folio_nr_pages(folio) - 1)); | |
208 | if (unlikely(!folio_test_checked(folio))) { | |
209 | if (!ext2_check_page(&folio->page, quiet, *page_addr)) | |
210 | goto fail; | |
1da177e4 | 211 | } |
37ce0b31 | 212 | return &folio->page; |
1da177e4 LT |
213 | |
214 | fail: | |
37ce0b31 | 215 | ext2_put_page(&folio->page, *page_addr); |
1da177e4 LT |
216 | return ERR_PTR(-EIO); |
217 | } | |
218 | ||
219 | /* | |
220 | * NOTE! unlike strncmp, ext2_match returns 1 for success, 0 for failure. | |
221 | * | |
222 | * len <= EXT2_NAME_LEN and de != NULL are guaranteed by caller. | |
223 | */ | |
224 | static inline int ext2_match (int len, const char * const name, | |
225 | struct ext2_dir_entry_2 * de) | |
226 | { | |
227 | if (len != de->name_len) | |
228 | return 0; | |
229 | if (!de->inode) | |
230 | return 0; | |
231 | return !memcmp(name, de->name, len); | |
232 | } | |
233 | ||
234 | /* | |
235 | * p is at least 6 bytes before the end of page | |
236 | */ | |
237 | static inline ext2_dirent *ext2_next_entry(ext2_dirent *p) | |
238 | { | |
89910ccc JK |
239 | return (ext2_dirent *)((char *)p + |
240 | ext2_rec_len_from_disk(p->rec_len)); | |
1da177e4 LT |
241 | } |
242 | ||
243 | static inline unsigned | |
244 | ext2_validate_entry(char *base, unsigned offset, unsigned mask) | |
245 | { | |
246 | ext2_dirent *de = (ext2_dirent*)(base + offset); | |
247 | ext2_dirent *p = (ext2_dirent*)(base + (offset&mask)); | |
248 | while ((char*)p < (char*)de) { | |
249 | if (p->rec_len == 0) | |
250 | break; | |
251 | p = ext2_next_entry(p); | |
252 | } | |
253 | return (char *)p - base; | |
254 | } | |
255 | ||
1da177e4 LT |
256 | static inline void ext2_set_de_type(ext2_dirent *de, struct inode *inode) |
257 | { | |
1da177e4 | 258 | if (EXT2_HAS_INCOMPAT_FEATURE(inode->i_sb, EXT2_FEATURE_INCOMPAT_FILETYPE)) |
e1089218 | 259 | de->file_type = fs_umode_to_ftype(inode->i_mode); |
1da177e4 LT |
260 | else |
261 | de->file_type = 0; | |
262 | } | |
263 | ||
264 | static int | |
80886298 | 265 | ext2_readdir(struct file *file, struct dir_context *ctx) |
1da177e4 | 266 | { |
80886298 AV |
267 | loff_t pos = ctx->pos; |
268 | struct inode *inode = file_inode(file); | |
1da177e4 | 269 | struct super_block *sb = inode->i_sb; |
09cbfeaf KS |
270 | unsigned int offset = pos & ~PAGE_MASK; |
271 | unsigned long n = pos >> PAGE_SHIFT; | |
1da177e4 LT |
272 | unsigned long npages = dir_pages(inode); |
273 | unsigned chunk_mask = ~(ext2_chunk_size(inode)-1); | |
c472c07b | 274 | bool need_revalidate = !inode_eq_iversion(inode, file->f_version); |
e1089218 | 275 | bool has_filetype; |
1da177e4 LT |
276 | |
277 | if (pos > inode->i_size - EXT2_DIR_REC_LEN(1)) | |
2d7f2ea9 | 278 | return 0; |
1da177e4 | 279 | |
e1089218 PP |
280 | has_filetype = |
281 | EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_FILETYPE); | |
1da177e4 LT |
282 | |
283 | for ( ; n < npages; n++, offset = 0) { | |
284 | char *kaddr, *limit; | |
285 | ext2_dirent *de; | |
782b76d7 | 286 | struct page *page = ext2_get_page(inode, n, 0, (void **)&kaddr); |
1da177e4 LT |
287 | |
288 | if (IS_ERR(page)) { | |
605afd60 | 289 | ext2_error(sb, __func__, |
1da177e4 LT |
290 | "bad page in #%lu", |
291 | inode->i_ino); | |
09cbfeaf | 292 | ctx->pos += PAGE_SIZE - offset; |
bbff2860 | 293 | return PTR_ERR(page); |
1da177e4 | 294 | } |
2d7f2ea9 AV |
295 | if (unlikely(need_revalidate)) { |
296 | if (offset) { | |
297 | offset = ext2_validate_entry(kaddr, offset, chunk_mask); | |
09cbfeaf | 298 | ctx->pos = (n<<PAGE_SHIFT) + offset; |
2d7f2ea9 | 299 | } |
e1d747d9 JL |
300 | file->f_version = inode_query_iversion(inode); |
301 | need_revalidate = false; | |
1da177e4 LT |
302 | } |
303 | de = (ext2_dirent *)(kaddr+offset); | |
304 | limit = kaddr + ext2_last_byte(inode, n) - EXT2_DIR_REC_LEN(1); | |
305 | for ( ;(char*)de <= limit; de = ext2_next_entry(de)) { | |
306 | if (de->rec_len == 0) { | |
605afd60 | 307 | ext2_error(sb, __func__, |
1da177e4 | 308 | "zero-length directory entry"); |
782b76d7 | 309 | ext2_put_page(page, kaddr); |
2d7f2ea9 | 310 | return -EIO; |
1da177e4 LT |
311 | } |
312 | if (de->inode) { | |
1da177e4 LT |
313 | unsigned char d_type = DT_UNKNOWN; |
314 | ||
e1089218 PP |
315 | if (has_filetype) |
316 | d_type = fs_ftype_to_dtype(de->file_type); | |
1da177e4 | 317 | |
80886298 AV |
318 | if (!dir_emit(ctx, de->name, de->name_len, |
319 | le32_to_cpu(de->inode), | |
320 | d_type)) { | |
782b76d7 | 321 | ext2_put_page(page, kaddr); |
2d7f2ea9 | 322 | return 0; |
1da177e4 LT |
323 | } |
324 | } | |
80886298 | 325 | ctx->pos += ext2_rec_len_from_disk(de->rec_len); |
1da177e4 | 326 | } |
782b76d7 | 327 | ext2_put_page(page, kaddr); |
1da177e4 | 328 | } |
2d7f2ea9 | 329 | return 0; |
1da177e4 LT |
330 | } |
331 | ||
332 | /* | |
333 | * ext2_find_entry() | |
334 | * | |
335 | * finds an entry in the specified directory with the wanted name. It | |
92e12888 JC |
336 | * returns the page in which the entry was found (as a parameter - res_page), |
337 | * and the entry itself. Page is returned mapped and unlocked. | |
1da177e4 | 338 | * Entry is guaranteed to be valid. |
a6fbd0ab IW |
339 | * |
340 | * On Success ext2_put_page() should be called on *res_page. | |
782b76d7 IW |
341 | * |
342 | * NOTE: Calls to ext2_get_page()/ext2_put_page() must be nested according to | |
343 | * the rules documented in kmap_local_page()/kunmap_local(). | |
344 | * | |
345 | * ext2_find_entry() and ext2_dotdot() act as a call to ext2_get_page() and | |
346 | * should be treated as a call to ext2_get_page() for nesting purposes. | |
1da177e4 | 347 | */ |
ac3ba644 | 348 | struct ext2_dir_entry_2 *ext2_find_entry (struct inode *dir, |
782b76d7 IW |
349 | const struct qstr *child, struct page **res_page, |
350 | void **res_page_addr) | |
1da177e4 | 351 | { |
a9885444 AV |
352 | const char *name = child->name; |
353 | int namelen = child->len; | |
1da177e4 LT |
354 | unsigned reclen = EXT2_DIR_REC_LEN(namelen); |
355 | unsigned long start, n; | |
356 | unsigned long npages = dir_pages(dir); | |
357 | struct page *page = NULL; | |
358 | struct ext2_inode_info *ei = EXT2_I(dir); | |
359 | ext2_dirent * de; | |
782b76d7 | 360 | void *page_addr; |
1da177e4 LT |
361 | |
362 | if (npages == 0) | |
363 | goto out; | |
364 | ||
365 | /* OFFSET_CACHE */ | |
366 | *res_page = NULL; | |
782b76d7 | 367 | *res_page_addr = NULL; |
1da177e4 LT |
368 | |
369 | start = ei->i_dir_start_lookup; | |
370 | if (start >= npages) | |
371 | start = 0; | |
372 | n = start; | |
373 | do { | |
374 | char *kaddr; | |
782b76d7 | 375 | page = ext2_get_page(dir, n, 0, &page_addr); |
b4962091 | 376 | if (IS_ERR(page)) |
377 | return ERR_CAST(page); | |
378 | ||
782b76d7 | 379 | kaddr = page_addr; |
b4962091 | 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, __func__, | |
385 | "zero-length directory entry"); | |
782b76d7 | 386 | ext2_put_page(page, page_addr); |
b4962091 | 387 | goto out; |
1da177e4 | 388 | } |
b4962091 | 389 | if (ext2_match(namelen, name, de)) |
390 | goto found; | |
391 | de = ext2_next_entry(de); | |
392 | } | |
782b76d7 | 393 | ext2_put_page(page, page_addr); |
bd39597c | 394 | |
1da177e4 LT |
395 | if (++n >= npages) |
396 | n = 0; | |
d8adb9ce | 397 | /* next page is past the blocks we've got */ |
09cbfeaf | 398 | if (unlikely(n > (dir->i_blocks >> (PAGE_SHIFT - 9)))) { |
605afd60 | 399 | ext2_error(dir->i_sb, __func__, |
d8adb9ce ES |
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: | |
a43850a3 | 407 | return ERR_PTR(-ENOENT); |
1da177e4 LT |
408 | |
409 | found: | |
410 | *res_page = page; | |
782b76d7 | 411 | *res_page_addr = page_addr; |
1da177e4 LT |
412 | ei->i_dir_start_lookup = n; |
413 | return de; | |
414 | } | |
415 | ||
a6fbd0ab IW |
416 | /** |
417 | * Return the '..' directory entry and the page in which the entry was found | |
418 | * (as a parameter - p). | |
419 | * | |
420 | * On Success ext2_put_page() should be called on *p. | |
782b76d7 IW |
421 | * |
422 | * NOTE: Calls to ext2_get_page()/ext2_put_page() must be nested according to | |
423 | * the rules documented in kmap_local_page()/kunmap_local(). | |
424 | * | |
425 | * ext2_find_entry() and ext2_dotdot() act as a call to ext2_get_page() and | |
426 | * should be treated as a call to ext2_get_page() for nesting purposes. | |
a6fbd0ab | 427 | */ |
782b76d7 IW |
428 | struct ext2_dir_entry_2 *ext2_dotdot(struct inode *dir, struct page **p, |
429 | void **pa) | |
1da177e4 | 430 | { |
782b76d7 IW |
431 | void *page_addr; |
432 | struct page *page = ext2_get_page(dir, 0, 0, &page_addr); | |
1da177e4 LT |
433 | ext2_dirent *de = NULL; |
434 | ||
435 | if (!IS_ERR(page)) { | |
782b76d7 | 436 | de = ext2_next_entry((ext2_dirent *) page_addr); |
1da177e4 | 437 | *p = page; |
782b76d7 | 438 | *pa = page_addr; |
1da177e4 LT |
439 | } |
440 | return de; | |
441 | } | |
442 | ||
b4962091 | 443 | int ext2_inode_by_name(struct inode *dir, const struct qstr *child, ino_t *ino) |
1da177e4 | 444 | { |
a9885444 | 445 | struct ext2_dir_entry_2 *de; |
1da177e4 | 446 | struct page *page; |
782b76d7 | 447 | void *page_addr; |
1da177e4 | 448 | |
782b76d7 | 449 | de = ext2_find_entry(dir, child, &page, &page_addr); |
a43850a3 | 450 | if (IS_ERR(de)) |
b4962091 | 451 | return PTR_ERR(de); |
452 | ||
453 | *ino = le32_to_cpu(de->inode); | |
782b76d7 | 454 | ext2_put_page(page, page_addr); |
b4962091 | 455 | return 0; |
1da177e4 LT |
456 | } |
457 | ||
f4e420dc CH |
458 | static int ext2_prepare_chunk(struct page *page, loff_t pos, unsigned len) |
459 | { | |
6e1db88d | 460 | return __block_write_begin(page, pos, len, ext2_get_block); |
f4e420dc CH |
461 | } |
462 | ||
1da177e4 | 463 | void ext2_set_link(struct inode *dir, struct ext2_dir_entry_2 *de, |
782b76d7 IW |
464 | struct page *page, void *page_addr, struct inode *inode, |
465 | int update_times) | |
1da177e4 | 466 | { |
f34fb6ec | 467 | loff_t pos = page_offset(page) + |
782b76d7 | 468 | (char *) de - (char *) page_addr; |
89910ccc | 469 | unsigned len = ext2_rec_len_from_disk(de->rec_len); |
1da177e4 LT |
470 | int err; |
471 | ||
472 | lock_page(page); | |
f4e420dc | 473 | err = ext2_prepare_chunk(page, pos, len); |
309be53d | 474 | BUG_ON(err); |
1da177e4 | 475 | de->inode = cpu_to_le32(inode->i_ino); |
f34fb6ec NP |
476 | ext2_set_de_type(de, inode); |
477 | err = ext2_commit_chunk(page, pos, len); | |
39fe7557 | 478 | if (update_times) |
02027d42 | 479 | dir->i_mtime = dir->i_ctime = current_time(dir); |
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 | { | |
2b0143b5 | 489 | struct inode *dir = d_inode(dentry->d_parent); |
1da177e4 LT |
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; | |
782b76d7 | 496 | void *page_addr = NULL; |
1da177e4 LT |
497 | ext2_dirent * de; |
498 | unsigned long npages = dir_pages(dir); | |
499 | unsigned long n; | |
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++) { | |
782b76d7 | 509 | char *kaddr; |
1da177e4 LT |
510 | char *dir_end; |
511 | ||
782b76d7 | 512 | page = ext2_get_page(dir, n, 0, &page_addr); |
1da177e4 LT |
513 | err = PTR_ERR(page); |
514 | if (IS_ERR(page)) | |
515 | goto out; | |
516 | lock_page(page); | |
782b76d7 | 517 | kaddr = page_addr; |
1da177e4 LT |
518 | dir_end = kaddr + ext2_last_byte(dir, n); |
519 | de = (ext2_dirent *)kaddr; | |
09cbfeaf | 520 | kaddr += PAGE_SIZE - reclen; |
1da177e4 LT |
521 | while ((char *)de <= kaddr) { |
522 | if ((char *)de == dir_end) { | |
523 | /* We hit i_size */ | |
524 | name_len = 0; | |
525 | rec_len = chunk_size; | |
89910ccc | 526 | de->rec_len = ext2_rec_len_to_disk(chunk_size); |
1da177e4 LT |
527 | de->inode = 0; |
528 | goto got_it; | |
529 | } | |
530 | if (de->rec_len == 0) { | |
605afd60 | 531 | ext2_error(dir->i_sb, __func__, |
1da177e4 LT |
532 | "zero-length directory entry"); |
533 | err = -EIO; | |
534 | goto out_unlock; | |
535 | } | |
536 | err = -EEXIST; | |
537 | if (ext2_match (namelen, name, de)) | |
538 | goto out_unlock; | |
539 | name_len = EXT2_DIR_REC_LEN(de->name_len); | |
89910ccc | 540 | rec_len = ext2_rec_len_from_disk(de->rec_len); |
1da177e4 LT |
541 | if (!de->inode && rec_len >= reclen) |
542 | goto got_it; | |
543 | if (rec_len >= name_len + reclen) | |
544 | goto got_it; | |
545 | de = (ext2_dirent *) ((char *) de + rec_len); | |
546 | } | |
547 | unlock_page(page); | |
782b76d7 | 548 | ext2_put_page(page, page_addr); |
1da177e4 LT |
549 | } |
550 | BUG(); | |
551 | return -EINVAL; | |
552 | ||
553 | got_it: | |
f34fb6ec | 554 | pos = page_offset(page) + |
782b76d7 | 555 | (char *)de - (char *)page_addr; |
f4e420dc | 556 | err = ext2_prepare_chunk(page, pos, rec_len); |
1da177e4 LT |
557 | if (err) |
558 | goto out_unlock; | |
559 | if (de->inode) { | |
560 | ext2_dirent *de1 = (ext2_dirent *) ((char *) de + name_len); | |
89910ccc JK |
561 | de1->rec_len = ext2_rec_len_to_disk(rec_len - name_len); |
562 | de->rec_len = ext2_rec_len_to_disk(name_len); | |
1da177e4 LT |
563 | de = de1; |
564 | } | |
565 | de->name_len = namelen; | |
f34fb6ec | 566 | memcpy(de->name, name, namelen); |
1da177e4 LT |
567 | de->inode = cpu_to_le32(inode->i_ino); |
568 | ext2_set_de_type (de, inode); | |
f34fb6ec | 569 | err = ext2_commit_chunk(page, pos, rec_len); |
02027d42 | 570 | dir->i_mtime = dir->i_ctime = current_time(dir); |
1da177e4 LT |
571 | EXT2_I(dir)->i_flags &= ~EXT2_BTREE_FL; |
572 | mark_inode_dirty(dir); | |
573 | /* OFFSET_CACHE */ | |
574 | out_put: | |
782b76d7 | 575 | ext2_put_page(page, page_addr); |
1da177e4 LT |
576 | out: |
577 | return err; | |
578 | out_unlock: | |
579 | unlock_page(page); | |
580 | goto out_put; | |
581 | } | |
582 | ||
583 | /* | |
584 | * ext2_delete_entry deletes a directory entry by merging it with the | |
e2ebb123 | 585 | * previous entry. Page is up-to-date. |
1da177e4 | 586 | */ |
728d392f JP |
587 | int ext2_delete_entry (struct ext2_dir_entry_2 *dir, struct page *page, |
588 | char *kaddr) | |
1da177e4 | 589 | { |
f4e420dc | 590 | struct inode *inode = page->mapping->host; |
1da177e4 | 591 | unsigned from = ((char*)dir - kaddr) & ~(ext2_chunk_size(inode)-1); |
89910ccc JK |
592 | unsigned to = ((char *)dir - kaddr) + |
593 | ext2_rec_len_from_disk(dir->rec_len); | |
f34fb6ec | 594 | loff_t pos; |
1da177e4 LT |
595 | ext2_dirent * pde = NULL; |
596 | ext2_dirent * de = (ext2_dirent *) (kaddr + from); | |
597 | int err; | |
598 | ||
599 | while ((char*)de < (char*)dir) { | |
600 | if (de->rec_len == 0) { | |
605afd60 | 601 | ext2_error(inode->i_sb, __func__, |
1da177e4 LT |
602 | "zero-length directory entry"); |
603 | err = -EIO; | |
604 | goto out; | |
605 | } | |
606 | pde = de; | |
607 | de = ext2_next_entry(de); | |
608 | } | |
609 | if (pde) | |
728d392f | 610 | from = (char *)pde - kaddr; |
f34fb6ec | 611 | pos = page_offset(page) + from; |
1da177e4 | 612 | lock_page(page); |
f4e420dc | 613 | err = ext2_prepare_chunk(page, pos, to - from); |
309be53d | 614 | BUG_ON(err); |
1da177e4 | 615 | if (pde) |
89910ccc | 616 | pde->rec_len = ext2_rec_len_to_disk(to - from); |
1da177e4 | 617 | dir->inode = 0; |
f34fb6ec | 618 | err = ext2_commit_chunk(page, pos, to - from); |
02027d42 | 619 | inode->i_ctime = inode->i_mtime = current_time(inode); |
1da177e4 LT |
620 | EXT2_I(inode)->i_flags &= ~EXT2_BTREE_FL; |
621 | mark_inode_dirty(inode); | |
622 | out: | |
1da177e4 LT |
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: | |
09cbfeaf | 663 | put_page(page); |
1da177e4 LT |
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 | { | |
782b76d7 | 672 | void *page_addr = NULL; |
1da177e4 LT |
673 | struct page *page = NULL; |
674 | unsigned long i, npages = dir_pages(inode); | |
675 | ||
676 | for (i = 0; i < npages; i++) { | |
677 | char *kaddr; | |
678 | ext2_dirent * de; | |
27cfa258 | 679 | page = ext2_get_page(inode, i, 0, &page_addr); |
1da177e4 | 680 | |
27cfa258 YB |
681 | if (IS_ERR(page)) |
682 | goto not_empty; | |
1da177e4 | 683 | |
782b76d7 | 684 | kaddr = page_addr; |
1da177e4 LT |
685 | de = (ext2_dirent *)kaddr; |
686 | kaddr += ext2_last_byte(inode, i) - EXT2_DIR_REC_LEN(1); | |
687 | ||
688 | while ((char *)de <= kaddr) { | |
689 | if (de->rec_len == 0) { | |
605afd60 | 690 | ext2_error(inode->i_sb, __func__, |
1da177e4 LT |
691 | "zero-length directory entry"); |
692 | printk("kaddr=%p, de=%p\n", kaddr, de); | |
693 | goto not_empty; | |
694 | } | |
695 | if (de->inode != 0) { | |
696 | /* check for . and .. */ | |
697 | if (de->name[0] != '.') | |
698 | goto not_empty; | |
699 | if (de->name_len > 2) | |
700 | goto not_empty; | |
701 | if (de->name_len < 2) { | |
702 | if (de->inode != | |
703 | cpu_to_le32(inode->i_ino)) | |
704 | goto not_empty; | |
705 | } else if (de->name[1] != '.') | |
706 | goto not_empty; | |
707 | } | |
708 | de = ext2_next_entry(de); | |
709 | } | |
782b76d7 | 710 | ext2_put_page(page, page_addr); |
1da177e4 LT |
711 | } |
712 | return 1; | |
713 | ||
714 | not_empty: | |
782b76d7 | 715 | ext2_put_page(page, page_addr); |
1da177e4 LT |
716 | return 0; |
717 | } | |
718 | ||
4b6f5d20 | 719 | const struct file_operations ext2_dir_operations = { |
1da177e4 LT |
720 | .llseek = generic_file_llseek, |
721 | .read = generic_read_dir, | |
3b0a3c1a | 722 | .iterate_shared = ext2_readdir, |
14f9f7b2 | 723 | .unlocked_ioctl = ext2_ioctl, |
e322ff07 DH |
724 | #ifdef CONFIG_COMPAT |
725 | .compat_ioctl = ext2_compat_ioctl, | |
726 | #endif | |
48bde86d | 727 | .fsync = ext2_fsync, |
1da177e4 | 728 | }; |