1 | // SPDX-License-Identifier: GPL-2.0+ |
2 | /* |
3 | * NILFS directory entry operations |
4 | * |
5 | * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation. |
6 | * |
7 | * Modified for NILFS by Amagai Yoshiji. |
8 | */ |
9 | /* |
10 | * linux/fs/ext2/dir.c |
11 | * |
12 | * Copyright (C) 1992, 1993, 1994, 1995 |
13 | * Remy Card (card@masi.ibp.fr) |
14 | * Laboratoire MASI - Institut Blaise Pascal |
15 | * Universite Pierre et Marie Curie (Paris VI) |
16 | * |
17 | * from |
18 | * |
19 | * linux/fs/minix/dir.c |
20 | * |
21 | * Copyright (C) 1991, 1992 Linus Torvalds |
22 | * |
23 | * ext2 directory handling functions |
24 | * |
25 | * Big-endian to little-endian byte-swapping/bitmaps by |
26 | * David S. Miller (davem@caip.rutgers.edu), 1995 |
27 | * |
28 | * All code that works with directory layout had been switched to pagecache |
29 | * and moved here. AV |
30 | */ |
31 | |
32 | #include <linux/pagemap.h> |
33 | #include "nilfs.h" |
34 | #include "page.h" |
35 | |
36 | static inline unsigned int nilfs_rec_len_from_disk(__le16 dlen) |
37 | { |
38 | unsigned int len = le16_to_cpu(dlen); |
39 | |
40 | #if (PAGE_SIZE >= 65536) |
41 | if (len == NILFS_MAX_REC_LEN) |
42 | return 1 << 16; |
43 | #endif |
44 | return len; |
45 | } |
46 | |
47 | static inline __le16 nilfs_rec_len_to_disk(unsigned int len) |
48 | { |
49 | #if (PAGE_SIZE >= 65536) |
50 | if (len == (1 << 16)) |
51 | return cpu_to_le16(NILFS_MAX_REC_LEN); |
52 | |
53 | BUG_ON(len > (1 << 16)); |
54 | #endif |
55 | return cpu_to_le16(len); |
56 | } |
57 | |
58 | /* |
59 | * nilfs uses block-sized chunks. Arguably, sector-sized ones would be |
60 | * more robust, but we have what we have |
61 | */ |
62 | static inline unsigned int nilfs_chunk_size(struct inode *inode) |
63 | { |
64 | return inode->i_sb->s_blocksize; |
65 | } |
66 | |
67 | /* |
68 | * Return the offset into page `page_nr' of the last valid |
69 | * byte in that page, plus one. |
70 | */ |
71 | static unsigned int nilfs_last_byte(struct inode *inode, unsigned long page_nr) |
72 | { |
73 | unsigned int last_byte = inode->i_size; |
74 | |
75 | last_byte -= page_nr << PAGE_SHIFT; |
76 | if (last_byte > PAGE_SIZE) |
77 | last_byte = PAGE_SIZE; |
78 | return last_byte; |
79 | } |
80 | |
81 | static int nilfs_prepare_chunk(struct folio *folio, unsigned int from, |
82 | unsigned int to) |
83 | { |
84 | loff_t pos = folio_pos(folio) + from; |
85 | |
86 | return __block_write_begin(page: &folio->page, pos, len: to - from, get_block: nilfs_get_block); |
87 | } |
88 | |
89 | static void nilfs_commit_chunk(struct folio *folio, |
90 | struct address_space *mapping, size_t from, size_t to) |
91 | { |
92 | struct inode *dir = mapping->host; |
93 | loff_t pos = folio_pos(folio) + from; |
94 | size_t copied, len = to - from; |
95 | unsigned int nr_dirty; |
96 | int err; |
97 | |
98 | nr_dirty = nilfs_page_count_clean_buffers(&folio->page, from, to); |
99 | copied = block_write_end(NULL, mapping, pos, len, len, &folio->page, NULL); |
100 | if (pos + copied > dir->i_size) |
101 | i_size_write(inode: dir, i_size: pos + copied); |
102 | if (IS_DIRSYNC(dir)) |
103 | nilfs_set_transaction_flag(NILFS_TI_SYNC); |
104 | err = nilfs_set_file_dirty(inode: dir, nr_dirty); |
105 | WARN_ON(err); /* do not happen */ |
106 | folio_unlock(folio); |
107 | } |
108 | |
109 | static bool nilfs_check_folio(struct folio *folio, char *kaddr) |
110 | { |
111 | struct inode *dir = folio->mapping->host; |
112 | struct super_block *sb = dir->i_sb; |
113 | unsigned int chunk_size = nilfs_chunk_size(inode: dir); |
114 | size_t offs, rec_len; |
115 | size_t limit = folio_size(folio); |
116 | struct nilfs_dir_entry *p; |
117 | char *error; |
118 | |
119 | if (dir->i_size < folio_pos(folio) + limit) { |
120 | limit = dir->i_size - folio_pos(folio); |
121 | if (limit & (chunk_size - 1)) |
122 | goto Ebadsize; |
123 | if (!limit) |
124 | goto out; |
125 | } |
126 | for (offs = 0; offs <= limit - NILFS_DIR_REC_LEN(1); offs += rec_len) { |
127 | p = (struct nilfs_dir_entry *)(kaddr + offs); |
128 | rec_len = nilfs_rec_len_from_disk(dlen: p->rec_len); |
129 | |
130 | if (rec_len < NILFS_DIR_REC_LEN(1)) |
131 | goto Eshort; |
132 | if (rec_len & 3) |
133 | goto Ealign; |
134 | if (rec_len < NILFS_DIR_REC_LEN(p->name_len)) |
135 | goto Enamelen; |
136 | if (((offs + rec_len - 1) ^ offs) & ~(chunk_size-1)) |
137 | goto Espan; |
138 | } |
139 | if (offs != limit) |
140 | goto Eend; |
141 | out: |
142 | folio_set_checked(folio); |
143 | return true; |
144 | |
145 | /* Too bad, we had an error */ |
146 | |
147 | Ebadsize: |
148 | nilfs_error(sb, |
149 | "size of directory #%lu is not a multiple of chunk size" , |
150 | dir->i_ino); |
151 | goto fail; |
152 | Eshort: |
153 | error = "rec_len is smaller than minimal" ; |
154 | goto bad_entry; |
155 | Ealign: |
156 | error = "unaligned directory entry" ; |
157 | goto bad_entry; |
158 | Enamelen: |
159 | error = "rec_len is too small for name_len" ; |
160 | goto bad_entry; |
161 | Espan: |
162 | error = "directory entry across blocks" ; |
163 | bad_entry: |
164 | nilfs_error(sb, |
165 | "bad entry in directory #%lu: %s - offset=%lu, inode=%lu, rec_len=%zd, name_len=%d" , |
166 | dir->i_ino, error, (folio->index << PAGE_SHIFT) + offs, |
167 | (unsigned long)le64_to_cpu(p->inode), |
168 | rec_len, p->name_len); |
169 | goto fail; |
170 | Eend: |
171 | p = (struct nilfs_dir_entry *)(kaddr + offs); |
172 | nilfs_error(sb, |
173 | "entry in directory #%lu spans the page boundary offset=%lu, inode=%lu" , |
174 | dir->i_ino, (folio->index << PAGE_SHIFT) + offs, |
175 | (unsigned long)le64_to_cpu(p->inode)); |
176 | fail: |
177 | folio_set_error(folio); |
178 | return false; |
179 | } |
180 | |
181 | static void *nilfs_get_folio(struct inode *dir, unsigned long n, |
182 | struct folio **foliop) |
183 | { |
184 | struct address_space *mapping = dir->i_mapping; |
185 | struct folio *folio = read_mapping_folio(mapping, index: n, NULL); |
186 | void *kaddr; |
187 | |
188 | if (IS_ERR(ptr: folio)) |
189 | return folio; |
190 | |
191 | kaddr = kmap_local_folio(folio, offset: 0); |
192 | if (unlikely(!folio_test_checked(folio))) { |
193 | if (!nilfs_check_folio(folio, kaddr)) |
194 | goto fail; |
195 | } |
196 | |
197 | *foliop = folio; |
198 | return kaddr; |
199 | |
200 | fail: |
201 | folio_release_kmap(folio, addr: kaddr); |
202 | return ERR_PTR(error: -EIO); |
203 | } |
204 | |
205 | /* |
206 | * NOTE! unlike strncmp, nilfs_match returns 1 for success, 0 for failure. |
207 | * |
208 | * len <= NILFS_NAME_LEN and de != NULL are guaranteed by caller. |
209 | */ |
210 | static int |
211 | nilfs_match(int len, const unsigned char *name, struct nilfs_dir_entry *de) |
212 | { |
213 | if (len != de->name_len) |
214 | return 0; |
215 | if (!de->inode) |
216 | return 0; |
217 | return !memcmp(p: name, q: de->name, size: len); |
218 | } |
219 | |
220 | /* |
221 | * p is at least 6 bytes before the end of page |
222 | */ |
223 | static struct nilfs_dir_entry *nilfs_next_entry(struct nilfs_dir_entry *p) |
224 | { |
225 | return (struct nilfs_dir_entry *)((char *)p + |
226 | nilfs_rec_len_from_disk(dlen: p->rec_len)); |
227 | } |
228 | |
229 | static unsigned char |
230 | nilfs_filetype_table[NILFS_FT_MAX] = { |
231 | [NILFS_FT_UNKNOWN] = DT_UNKNOWN, |
232 | [NILFS_FT_REG_FILE] = DT_REG, |
233 | [NILFS_FT_DIR] = DT_DIR, |
234 | [NILFS_FT_CHRDEV] = DT_CHR, |
235 | [NILFS_FT_BLKDEV] = DT_BLK, |
236 | [NILFS_FT_FIFO] = DT_FIFO, |
237 | [NILFS_FT_SOCK] = DT_SOCK, |
238 | [NILFS_FT_SYMLINK] = DT_LNK, |
239 | }; |
240 | |
241 | #define S_SHIFT 12 |
242 | static unsigned char |
243 | nilfs_type_by_mode[(S_IFMT >> S_SHIFT) + 1] = { |
244 | [S_IFREG >> S_SHIFT] = NILFS_FT_REG_FILE, |
245 | [S_IFDIR >> S_SHIFT] = NILFS_FT_DIR, |
246 | [S_IFCHR >> S_SHIFT] = NILFS_FT_CHRDEV, |
247 | [S_IFBLK >> S_SHIFT] = NILFS_FT_BLKDEV, |
248 | [S_IFIFO >> S_SHIFT] = NILFS_FT_FIFO, |
249 | [S_IFSOCK >> S_SHIFT] = NILFS_FT_SOCK, |
250 | [S_IFLNK >> S_SHIFT] = NILFS_FT_SYMLINK, |
251 | }; |
252 | |
253 | static void nilfs_set_de_type(struct nilfs_dir_entry *de, struct inode *inode) |
254 | { |
255 | umode_t mode = inode->i_mode; |
256 | |
257 | de->file_type = nilfs_type_by_mode[(mode & S_IFMT)>>S_SHIFT]; |
258 | } |
259 | |
260 | static int nilfs_readdir(struct file *file, struct dir_context *ctx) |
261 | { |
262 | loff_t pos = ctx->pos; |
263 | struct inode *inode = file_inode(f: file); |
264 | struct super_block *sb = inode->i_sb; |
265 | unsigned int offset = pos & ~PAGE_MASK; |
266 | unsigned long n = pos >> PAGE_SHIFT; |
267 | unsigned long npages = dir_pages(inode); |
268 | |
269 | if (pos > inode->i_size - NILFS_DIR_REC_LEN(1)) |
270 | return 0; |
271 | |
272 | for ( ; n < npages; n++, offset = 0) { |
273 | char *kaddr, *limit; |
274 | struct nilfs_dir_entry *de; |
275 | struct folio *folio; |
276 | |
277 | kaddr = nilfs_get_folio(dir: inode, n, foliop: &folio); |
278 | if (IS_ERR(ptr: kaddr)) { |
279 | nilfs_error(sb, "bad page in #%lu" , inode->i_ino); |
280 | ctx->pos += PAGE_SIZE - offset; |
281 | return -EIO; |
282 | } |
283 | de = (struct nilfs_dir_entry *)(kaddr + offset); |
284 | limit = kaddr + nilfs_last_byte(inode, page_nr: n) - |
285 | NILFS_DIR_REC_LEN(1); |
286 | for ( ; (char *)de <= limit; de = nilfs_next_entry(p: de)) { |
287 | if (de->rec_len == 0) { |
288 | nilfs_error(sb, "zero-length directory entry" ); |
289 | folio_release_kmap(folio, addr: kaddr); |
290 | return -EIO; |
291 | } |
292 | if (de->inode) { |
293 | unsigned char t; |
294 | |
295 | if (de->file_type < NILFS_FT_MAX) |
296 | t = nilfs_filetype_table[de->file_type]; |
297 | else |
298 | t = DT_UNKNOWN; |
299 | |
300 | if (!dir_emit(ctx, name: de->name, namelen: de->name_len, |
301 | le64_to_cpu(de->inode), type: t)) { |
302 | folio_release_kmap(folio, addr: kaddr); |
303 | return 0; |
304 | } |
305 | } |
306 | ctx->pos += nilfs_rec_len_from_disk(dlen: de->rec_len); |
307 | } |
308 | folio_release_kmap(folio, addr: kaddr); |
309 | } |
310 | return 0; |
311 | } |
312 | |
313 | /* |
314 | * nilfs_find_entry() |
315 | * |
316 | * Finds an entry in the specified directory with the wanted name. It |
317 | * returns the folio in which the entry was found, and the entry itself. |
318 | * The folio is mapped and unlocked. When the caller is finished with |
319 | * the entry, it should call folio_release_kmap(). |
320 | * |
321 | * On failure, returns NULL and the caller should ignore foliop. |
322 | */ |
323 | struct nilfs_dir_entry *nilfs_find_entry(struct inode *dir, |
324 | const struct qstr *qstr, struct folio **foliop) |
325 | { |
326 | const unsigned char *name = qstr->name; |
327 | int namelen = qstr->len; |
328 | unsigned int reclen = NILFS_DIR_REC_LEN(namelen); |
329 | unsigned long start, n; |
330 | unsigned long npages = dir_pages(inode: dir); |
331 | struct nilfs_inode_info *ei = NILFS_I(inode: dir); |
332 | struct nilfs_dir_entry *de; |
333 | |
334 | if (npages == 0) |
335 | goto out; |
336 | |
337 | start = ei->i_dir_start_lookup; |
338 | if (start >= npages) |
339 | start = 0; |
340 | n = start; |
341 | do { |
342 | char *kaddr = nilfs_get_folio(dir, n, foliop); |
343 | |
344 | if (!IS_ERR(ptr: kaddr)) { |
345 | de = (struct nilfs_dir_entry *)kaddr; |
346 | kaddr += nilfs_last_byte(inode: dir, page_nr: n) - reclen; |
347 | while ((char *) de <= kaddr) { |
348 | if (de->rec_len == 0) { |
349 | nilfs_error(dir->i_sb, |
350 | "zero-length directory entry" ); |
351 | folio_release_kmap(folio: *foliop, addr: kaddr); |
352 | goto out; |
353 | } |
354 | if (nilfs_match(len: namelen, name, de)) |
355 | goto found; |
356 | de = nilfs_next_entry(p: de); |
357 | } |
358 | folio_release_kmap(folio: *foliop, addr: kaddr); |
359 | } |
360 | if (++n >= npages) |
361 | n = 0; |
362 | /* next folio is past the blocks we've got */ |
363 | if (unlikely(n > (dir->i_blocks >> (PAGE_SHIFT - 9)))) { |
364 | nilfs_error(dir->i_sb, |
365 | "dir %lu size %lld exceeds block count %llu" , |
366 | dir->i_ino, dir->i_size, |
367 | (unsigned long long)dir->i_blocks); |
368 | goto out; |
369 | } |
370 | } while (n != start); |
371 | out: |
372 | return NULL; |
373 | |
374 | found: |
375 | ei->i_dir_start_lookup = n; |
376 | return de; |
377 | } |
378 | |
379 | struct nilfs_dir_entry *nilfs_dotdot(struct inode *dir, struct folio **foliop) |
380 | { |
381 | struct nilfs_dir_entry *de = nilfs_get_folio(dir, n: 0, foliop); |
382 | |
383 | if (IS_ERR(ptr: de)) |
384 | return NULL; |
385 | return nilfs_next_entry(p: de); |
386 | } |
387 | |
388 | ino_t nilfs_inode_by_name(struct inode *dir, const struct qstr *qstr) |
389 | { |
390 | ino_t res = 0; |
391 | struct nilfs_dir_entry *de; |
392 | struct folio *folio; |
393 | |
394 | de = nilfs_find_entry(dir, qstr, foliop: &folio); |
395 | if (de) { |
396 | res = le64_to_cpu(de->inode); |
397 | folio_release_kmap(folio, addr: de); |
398 | } |
399 | return res; |
400 | } |
401 | |
402 | void nilfs_set_link(struct inode *dir, struct nilfs_dir_entry *de, |
403 | struct folio *folio, struct inode *inode) |
404 | { |
405 | size_t from = offset_in_folio(folio, de); |
406 | size_t to = from + nilfs_rec_len_from_disk(dlen: de->rec_len); |
407 | struct address_space *mapping = folio->mapping; |
408 | int err; |
409 | |
410 | folio_lock(folio); |
411 | err = nilfs_prepare_chunk(folio, from, to); |
412 | BUG_ON(err); |
413 | de->inode = cpu_to_le64(inode->i_ino); |
414 | nilfs_set_de_type(de, inode); |
415 | nilfs_commit_chunk(folio, mapping, from, to); |
416 | inode_set_mtime_to_ts(inode: dir, ts: inode_set_ctime_current(inode: dir)); |
417 | } |
418 | |
419 | /* |
420 | * Parent is locked. |
421 | */ |
422 | int nilfs_add_link(struct dentry *dentry, struct inode *inode) |
423 | { |
424 | struct inode *dir = d_inode(dentry: dentry->d_parent); |
425 | const unsigned char *name = dentry->d_name.name; |
426 | int namelen = dentry->d_name.len; |
427 | unsigned int chunk_size = nilfs_chunk_size(inode: dir); |
428 | unsigned int reclen = NILFS_DIR_REC_LEN(namelen); |
429 | unsigned short rec_len, name_len; |
430 | struct folio *folio = NULL; |
431 | struct nilfs_dir_entry *de; |
432 | unsigned long npages = dir_pages(inode: dir); |
433 | unsigned long n; |
434 | size_t from, to; |
435 | int err; |
436 | |
437 | /* |
438 | * We take care of directory expansion in the same loop. |
439 | * This code plays outside i_size, so it locks the folio |
440 | * to protect that region. |
441 | */ |
442 | for (n = 0; n <= npages; n++) { |
443 | char *kaddr = nilfs_get_folio(dir, n, foliop: &folio); |
444 | char *dir_end; |
445 | |
446 | if (IS_ERR(ptr: kaddr)) |
447 | return PTR_ERR(ptr: kaddr); |
448 | folio_lock(folio); |
449 | dir_end = kaddr + nilfs_last_byte(inode: dir, page_nr: n); |
450 | de = (struct nilfs_dir_entry *)kaddr; |
451 | kaddr += folio_size(folio) - reclen; |
452 | while ((char *)de <= kaddr) { |
453 | if ((char *)de == dir_end) { |
454 | /* We hit i_size */ |
455 | name_len = 0; |
456 | rec_len = chunk_size; |
457 | de->rec_len = nilfs_rec_len_to_disk(len: chunk_size); |
458 | de->inode = 0; |
459 | goto got_it; |
460 | } |
461 | if (de->rec_len == 0) { |
462 | nilfs_error(dir->i_sb, |
463 | "zero-length directory entry" ); |
464 | err = -EIO; |
465 | goto out_unlock; |
466 | } |
467 | err = -EEXIST; |
468 | if (nilfs_match(len: namelen, name, de)) |
469 | goto out_unlock; |
470 | name_len = NILFS_DIR_REC_LEN(de->name_len); |
471 | rec_len = nilfs_rec_len_from_disk(dlen: de->rec_len); |
472 | if (!de->inode && rec_len >= reclen) |
473 | goto got_it; |
474 | if (rec_len >= name_len + reclen) |
475 | goto got_it; |
476 | de = (struct nilfs_dir_entry *)((char *)de + rec_len); |
477 | } |
478 | folio_unlock(folio); |
479 | folio_release_kmap(folio, addr: kaddr); |
480 | } |
481 | BUG(); |
482 | return -EINVAL; |
483 | |
484 | got_it: |
485 | from = offset_in_folio(folio, de); |
486 | to = from + rec_len; |
487 | err = nilfs_prepare_chunk(folio, from, to); |
488 | if (err) |
489 | goto out_unlock; |
490 | if (de->inode) { |
491 | struct nilfs_dir_entry *de1; |
492 | |
493 | de1 = (struct nilfs_dir_entry *)((char *)de + name_len); |
494 | de1->rec_len = nilfs_rec_len_to_disk(len: rec_len - name_len); |
495 | de->rec_len = nilfs_rec_len_to_disk(len: name_len); |
496 | de = de1; |
497 | } |
498 | de->name_len = namelen; |
499 | memcpy(de->name, name, namelen); |
500 | de->inode = cpu_to_le64(inode->i_ino); |
501 | nilfs_set_de_type(de, inode); |
502 | nilfs_commit_chunk(folio, mapping: folio->mapping, from, to); |
503 | inode_set_mtime_to_ts(inode: dir, ts: inode_set_ctime_current(inode: dir)); |
504 | nilfs_mark_inode_dirty(inode: dir); |
505 | /* OFFSET_CACHE */ |
506 | out_put: |
507 | folio_release_kmap(folio, addr: de); |
508 | return err; |
509 | out_unlock: |
510 | folio_unlock(folio); |
511 | goto out_put; |
512 | } |
513 | |
514 | /* |
515 | * nilfs_delete_entry deletes a directory entry by merging it with the |
516 | * previous entry. Folio is up-to-date. |
517 | */ |
518 | int nilfs_delete_entry(struct nilfs_dir_entry *dir, struct folio *folio) |
519 | { |
520 | struct address_space *mapping = folio->mapping; |
521 | struct inode *inode = mapping->host; |
522 | char *kaddr = (char *)((unsigned long)dir & ~(folio_size(folio) - 1)); |
523 | size_t from, to; |
524 | struct nilfs_dir_entry *de, *pde = NULL; |
525 | int err; |
526 | |
527 | from = ((char *)dir - kaddr) & ~(nilfs_chunk_size(inode) - 1); |
528 | to = ((char *)dir - kaddr) + nilfs_rec_len_from_disk(dlen: dir->rec_len); |
529 | de = (struct nilfs_dir_entry *)(kaddr + from); |
530 | |
531 | while ((char *)de < (char *)dir) { |
532 | if (de->rec_len == 0) { |
533 | nilfs_error(inode->i_sb, |
534 | "zero-length directory entry" ); |
535 | err = -EIO; |
536 | goto out; |
537 | } |
538 | pde = de; |
539 | de = nilfs_next_entry(p: de); |
540 | } |
541 | if (pde) |
542 | from = (char *)pde - kaddr; |
543 | folio_lock(folio); |
544 | err = nilfs_prepare_chunk(folio, from, to); |
545 | BUG_ON(err); |
546 | if (pde) |
547 | pde->rec_len = nilfs_rec_len_to_disk(len: to - from); |
548 | dir->inode = 0; |
549 | nilfs_commit_chunk(folio, mapping, from, to); |
550 | inode_set_mtime_to_ts(inode, ts: inode_set_ctime_current(inode)); |
551 | out: |
552 | return err; |
553 | } |
554 | |
555 | /* |
556 | * Set the first fragment of directory. |
557 | */ |
558 | int nilfs_make_empty(struct inode *inode, struct inode *parent) |
559 | { |
560 | struct address_space *mapping = inode->i_mapping; |
561 | struct folio *folio = filemap_grab_folio(mapping, index: 0); |
562 | unsigned int chunk_size = nilfs_chunk_size(inode); |
563 | struct nilfs_dir_entry *de; |
564 | int err; |
565 | void *kaddr; |
566 | |
567 | if (IS_ERR(ptr: folio)) |
568 | return PTR_ERR(ptr: folio); |
569 | |
570 | err = nilfs_prepare_chunk(folio, from: 0, to: chunk_size); |
571 | if (unlikely(err)) { |
572 | folio_unlock(folio); |
573 | goto fail; |
574 | } |
575 | kaddr = kmap_local_folio(folio, offset: 0); |
576 | memset(kaddr, 0, chunk_size); |
577 | de = (struct nilfs_dir_entry *)kaddr; |
578 | de->name_len = 1; |
579 | de->rec_len = nilfs_rec_len_to_disk(NILFS_DIR_REC_LEN(1)); |
580 | memcpy(de->name, ".\0\0" , 4); |
581 | de->inode = cpu_to_le64(inode->i_ino); |
582 | nilfs_set_de_type(de, inode); |
583 | |
584 | de = (struct nilfs_dir_entry *)(kaddr + NILFS_DIR_REC_LEN(1)); |
585 | de->name_len = 2; |
586 | de->rec_len = nilfs_rec_len_to_disk(len: chunk_size - NILFS_DIR_REC_LEN(1)); |
587 | de->inode = cpu_to_le64(parent->i_ino); |
588 | memcpy(de->name, "..\0" , 4); |
589 | nilfs_set_de_type(de, inode); |
590 | kunmap_local(kaddr); |
591 | nilfs_commit_chunk(folio, mapping, from: 0, to: chunk_size); |
592 | fail: |
593 | folio_put(folio); |
594 | return err; |
595 | } |
596 | |
597 | /* |
598 | * routine to check that the specified directory is empty (for rmdir) |
599 | */ |
600 | int nilfs_empty_dir(struct inode *inode) |
601 | { |
602 | struct folio *folio = NULL; |
603 | char *kaddr; |
604 | unsigned long i, npages = dir_pages(inode); |
605 | |
606 | for (i = 0; i < npages; i++) { |
607 | struct nilfs_dir_entry *de; |
608 | |
609 | kaddr = nilfs_get_folio(dir: inode, n: i, foliop: &folio); |
610 | if (IS_ERR(ptr: kaddr)) |
611 | continue; |
612 | |
613 | de = (struct nilfs_dir_entry *)kaddr; |
614 | kaddr += nilfs_last_byte(inode, page_nr: i) - NILFS_DIR_REC_LEN(1); |
615 | |
616 | while ((char *)de <= kaddr) { |
617 | if (de->rec_len == 0) { |
618 | nilfs_error(inode->i_sb, |
619 | "zero-length directory entry (kaddr=%p, de=%p)" , |
620 | kaddr, de); |
621 | goto not_empty; |
622 | } |
623 | if (de->inode != 0) { |
624 | /* check for . and .. */ |
625 | if (de->name[0] != '.') |
626 | goto not_empty; |
627 | if (de->name_len > 2) |
628 | goto not_empty; |
629 | if (de->name_len < 2) { |
630 | if (de->inode != |
631 | cpu_to_le64(inode->i_ino)) |
632 | goto not_empty; |
633 | } else if (de->name[1] != '.') |
634 | goto not_empty; |
635 | } |
636 | de = nilfs_next_entry(p: de); |
637 | } |
638 | folio_release_kmap(folio, addr: kaddr); |
639 | } |
640 | return 1; |
641 | |
642 | not_empty: |
643 | folio_release_kmap(folio, addr: kaddr); |
644 | return 0; |
645 | } |
646 | |
647 | const struct file_operations nilfs_dir_operations = { |
648 | .llseek = generic_file_llseek, |
649 | .read = generic_read_dir, |
650 | .iterate_shared = nilfs_readdir, |
651 | .unlocked_ioctl = nilfs_ioctl, |
652 | #ifdef CONFIG_COMPAT |
653 | .compat_ioctl = nilfs_compat_ioctl, |
654 | #endif /* CONFIG_COMPAT */ |
655 | .fsync = nilfs_sync_file, |
656 | |
657 | }; |
658 | |