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selinux: fix overflow and 0 length allocations
[deliverable/linux.git] / fs / f2fs / dir.c
1 /*
2 * fs/f2fs/dir.c
3 *
4 * Copyright (c) 2012 Samsung Electronics Co., Ltd.
5 * http://www.samsung.com/
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11 #include <linux/fs.h>
12 #include <linux/f2fs_fs.h>
13 #include "f2fs.h"
14 #include "node.h"
15 #include "acl.h"
16 #include "xattr.h"
17
18 static unsigned long dir_blocks(struct inode *inode)
19 {
20 return ((unsigned long long) (i_size_read(inode) + PAGE_SIZE - 1))
21 >> PAGE_SHIFT;
22 }
23
24 static unsigned int dir_buckets(unsigned int level, int dir_level)
25 {
26 if (level + dir_level < MAX_DIR_HASH_DEPTH / 2)
27 return 1 << (level + dir_level);
28 else
29 return MAX_DIR_BUCKETS;
30 }
31
32 static unsigned int bucket_blocks(unsigned int level)
33 {
34 if (level < MAX_DIR_HASH_DEPTH / 2)
35 return 2;
36 else
37 return 4;
38 }
39
40 unsigned char f2fs_filetype_table[F2FS_FT_MAX] = {
41 [F2FS_FT_UNKNOWN] = DT_UNKNOWN,
42 [F2FS_FT_REG_FILE] = DT_REG,
43 [F2FS_FT_DIR] = DT_DIR,
44 [F2FS_FT_CHRDEV] = DT_CHR,
45 [F2FS_FT_BLKDEV] = DT_BLK,
46 [F2FS_FT_FIFO] = DT_FIFO,
47 [F2FS_FT_SOCK] = DT_SOCK,
48 [F2FS_FT_SYMLINK] = DT_LNK,
49 };
50
51 static unsigned char f2fs_type_by_mode[S_IFMT >> S_SHIFT] = {
52 [S_IFREG >> S_SHIFT] = F2FS_FT_REG_FILE,
53 [S_IFDIR >> S_SHIFT] = F2FS_FT_DIR,
54 [S_IFCHR >> S_SHIFT] = F2FS_FT_CHRDEV,
55 [S_IFBLK >> S_SHIFT] = F2FS_FT_BLKDEV,
56 [S_IFIFO >> S_SHIFT] = F2FS_FT_FIFO,
57 [S_IFSOCK >> S_SHIFT] = F2FS_FT_SOCK,
58 [S_IFLNK >> S_SHIFT] = F2FS_FT_SYMLINK,
59 };
60
61 void set_de_type(struct f2fs_dir_entry *de, umode_t mode)
62 {
63 de->file_type = f2fs_type_by_mode[(mode & S_IFMT) >> S_SHIFT];
64 }
65
66 unsigned char get_de_type(struct f2fs_dir_entry *de)
67 {
68 if (de->file_type < F2FS_FT_MAX)
69 return f2fs_filetype_table[de->file_type];
70 return DT_UNKNOWN;
71 }
72
73 static unsigned long dir_block_index(unsigned int level,
74 int dir_level, unsigned int idx)
75 {
76 unsigned long i;
77 unsigned long bidx = 0;
78
79 for (i = 0; i < level; i++)
80 bidx += dir_buckets(i, dir_level) * bucket_blocks(i);
81 bidx += idx * bucket_blocks(level);
82 return bidx;
83 }
84
85 static struct f2fs_dir_entry *find_in_block(struct page *dentry_page,
86 struct fscrypt_name *fname,
87 f2fs_hash_t namehash,
88 int *max_slots,
89 struct page **res_page)
90 {
91 struct f2fs_dentry_block *dentry_blk;
92 struct f2fs_dir_entry *de;
93 struct f2fs_dentry_ptr d;
94
95 dentry_blk = (struct f2fs_dentry_block *)kmap(dentry_page);
96
97 make_dentry_ptr(NULL, &d, (void *)dentry_blk, 1);
98 de = find_target_dentry(fname, namehash, max_slots, &d);
99 if (de)
100 *res_page = dentry_page;
101 else
102 kunmap(dentry_page);
103
104 return de;
105 }
106
107 struct f2fs_dir_entry *find_target_dentry(struct fscrypt_name *fname,
108 f2fs_hash_t namehash, int *max_slots,
109 struct f2fs_dentry_ptr *d)
110 {
111 struct f2fs_dir_entry *de;
112 unsigned long bit_pos = 0;
113 int max_len = 0;
114 struct fscrypt_str de_name = FSTR_INIT(NULL, 0);
115 struct fscrypt_str *name = &fname->disk_name;
116
117 if (max_slots)
118 *max_slots = 0;
119 while (bit_pos < d->max) {
120 if (!test_bit_le(bit_pos, d->bitmap)) {
121 bit_pos++;
122 max_len++;
123 continue;
124 }
125
126 de = &d->dentry[bit_pos];
127
128 if (unlikely(!de->name_len)) {
129 bit_pos++;
130 continue;
131 }
132
133 /* encrypted case */
134 de_name.name = d->filename[bit_pos];
135 de_name.len = le16_to_cpu(de->name_len);
136
137 /* show encrypted name */
138 if (fname->hash) {
139 if (de->hash_code == fname->hash)
140 goto found;
141 } else if (de_name.len == name->len &&
142 de->hash_code == namehash &&
143 !memcmp(de_name.name, name->name, name->len))
144 goto found;
145
146 if (max_slots && max_len > *max_slots)
147 *max_slots = max_len;
148 max_len = 0;
149
150 bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
151 }
152
153 de = NULL;
154 found:
155 if (max_slots && max_len > *max_slots)
156 *max_slots = max_len;
157 return de;
158 }
159
160 static struct f2fs_dir_entry *find_in_level(struct inode *dir,
161 unsigned int level,
162 struct fscrypt_name *fname,
163 struct page **res_page)
164 {
165 struct qstr name = FSTR_TO_QSTR(&fname->disk_name);
166 int s = GET_DENTRY_SLOTS(name.len);
167 unsigned int nbucket, nblock;
168 unsigned int bidx, end_block;
169 struct page *dentry_page;
170 struct f2fs_dir_entry *de = NULL;
171 bool room = false;
172 int max_slots;
173 f2fs_hash_t namehash;
174
175 namehash = f2fs_dentry_hash(&name);
176
177 nbucket = dir_buckets(level, F2FS_I(dir)->i_dir_level);
178 nblock = bucket_blocks(level);
179
180 bidx = dir_block_index(level, F2FS_I(dir)->i_dir_level,
181 le32_to_cpu(namehash) % nbucket);
182 end_block = bidx + nblock;
183
184 for (; bidx < end_block; bidx++) {
185 /* no need to allocate new dentry pages to all the indices */
186 dentry_page = find_data_page(dir, bidx);
187 if (IS_ERR(dentry_page)) {
188 if (PTR_ERR(dentry_page) == -ENOENT) {
189 room = true;
190 continue;
191 } else {
192 *res_page = dentry_page;
193 break;
194 }
195 }
196
197 de = find_in_block(dentry_page, fname, namehash, &max_slots,
198 res_page);
199 if (de)
200 break;
201
202 if (max_slots >= s)
203 room = true;
204 f2fs_put_page(dentry_page, 0);
205 }
206
207 if (!de && room && F2FS_I(dir)->chash != namehash) {
208 F2FS_I(dir)->chash = namehash;
209 F2FS_I(dir)->clevel = level;
210 }
211
212 return de;
213 }
214
215 /*
216 * Find an entry in the specified directory with the wanted name.
217 * It returns the page where the entry was found (as a parameter - res_page),
218 * and the entry itself. Page is returned mapped and unlocked.
219 * Entry is guaranteed to be valid.
220 */
221 struct f2fs_dir_entry *f2fs_find_entry(struct inode *dir,
222 const struct qstr *child, struct page **res_page)
223 {
224 unsigned long npages = dir_blocks(dir);
225 struct f2fs_dir_entry *de = NULL;
226 unsigned int max_depth;
227 unsigned int level;
228 struct fscrypt_name fname;
229 int err;
230
231 err = fscrypt_setup_filename(dir, child, 1, &fname);
232 if (err) {
233 *res_page = ERR_PTR(err);
234 return NULL;
235 }
236
237 if (f2fs_has_inline_dentry(dir)) {
238 *res_page = NULL;
239 de = find_in_inline_dir(dir, &fname, res_page);
240 goto out;
241 }
242
243 if (npages == 0) {
244 *res_page = NULL;
245 goto out;
246 }
247
248 max_depth = F2FS_I(dir)->i_current_depth;
249 if (unlikely(max_depth > MAX_DIR_HASH_DEPTH)) {
250 f2fs_msg(F2FS_I_SB(dir)->sb, KERN_WARNING,
251 "Corrupted max_depth of %lu: %u",
252 dir->i_ino, max_depth);
253 max_depth = MAX_DIR_HASH_DEPTH;
254 f2fs_i_depth_write(dir, max_depth);
255 }
256
257 for (level = 0; level < max_depth; level++) {
258 *res_page = NULL;
259 de = find_in_level(dir, level, &fname, res_page);
260 if (de || IS_ERR(*res_page))
261 break;
262 }
263 out:
264 fscrypt_free_filename(&fname);
265 return de;
266 }
267
268 struct f2fs_dir_entry *f2fs_parent_dir(struct inode *dir, struct page **p)
269 {
270 struct qstr dotdot = QSTR_INIT("..", 2);
271
272 return f2fs_find_entry(dir, &dotdot, p);
273 }
274
275 ino_t f2fs_inode_by_name(struct inode *dir, const struct qstr *qstr,
276 struct page **page)
277 {
278 ino_t res = 0;
279 struct f2fs_dir_entry *de;
280
281 de = f2fs_find_entry(dir, qstr, page);
282 if (de) {
283 res = le32_to_cpu(de->ino);
284 f2fs_dentry_kunmap(dir, *page);
285 f2fs_put_page(*page, 0);
286 }
287
288 return res;
289 }
290
291 void f2fs_set_link(struct inode *dir, struct f2fs_dir_entry *de,
292 struct page *page, struct inode *inode)
293 {
294 enum page_type type = f2fs_has_inline_dentry(dir) ? NODE : DATA;
295 lock_page(page);
296 f2fs_wait_on_page_writeback(page, type, true);
297 de->ino = cpu_to_le32(inode->i_ino);
298 set_de_type(de, inode->i_mode);
299 f2fs_dentry_kunmap(dir, page);
300 set_page_dirty(page);
301
302 dir->i_mtime = dir->i_ctime = CURRENT_TIME;
303 f2fs_mark_inode_dirty_sync(dir);
304 f2fs_put_page(page, 1);
305 }
306
307 static void init_dent_inode(const struct qstr *name, struct page *ipage)
308 {
309 struct f2fs_inode *ri;
310
311 f2fs_wait_on_page_writeback(ipage, NODE, true);
312
313 /* copy name info. to this inode page */
314 ri = F2FS_INODE(ipage);
315 ri->i_namelen = cpu_to_le32(name->len);
316 memcpy(ri->i_name, name->name, name->len);
317 set_page_dirty(ipage);
318 }
319
320 int update_dent_inode(struct inode *inode, struct inode *to,
321 const struct qstr *name)
322 {
323 struct page *page;
324
325 if (file_enc_name(to))
326 return 0;
327
328 page = get_node_page(F2FS_I_SB(inode), inode->i_ino);
329 if (IS_ERR(page))
330 return PTR_ERR(page);
331
332 init_dent_inode(name, page);
333 f2fs_put_page(page, 1);
334
335 return 0;
336 }
337
338 void do_make_empty_dir(struct inode *inode, struct inode *parent,
339 struct f2fs_dentry_ptr *d)
340 {
341 struct qstr dot = QSTR_INIT(".", 1);
342 struct qstr dotdot = QSTR_INIT("..", 2);
343
344 /* update dirent of "." */
345 f2fs_update_dentry(inode->i_ino, inode->i_mode, d, &dot, 0, 0);
346
347 /* update dirent of ".." */
348 f2fs_update_dentry(parent->i_ino, parent->i_mode, d, &dotdot, 0, 1);
349 }
350
351 static int make_empty_dir(struct inode *inode,
352 struct inode *parent, struct page *page)
353 {
354 struct page *dentry_page;
355 struct f2fs_dentry_block *dentry_blk;
356 struct f2fs_dentry_ptr d;
357
358 if (f2fs_has_inline_dentry(inode))
359 return make_empty_inline_dir(inode, parent, page);
360
361 dentry_page = get_new_data_page(inode, page, 0, true);
362 if (IS_ERR(dentry_page))
363 return PTR_ERR(dentry_page);
364
365 dentry_blk = kmap_atomic(dentry_page);
366
367 make_dentry_ptr(NULL, &d, (void *)dentry_blk, 1);
368 do_make_empty_dir(inode, parent, &d);
369
370 kunmap_atomic(dentry_blk);
371
372 set_page_dirty(dentry_page);
373 f2fs_put_page(dentry_page, 1);
374 return 0;
375 }
376
377 struct page *init_inode_metadata(struct inode *inode, struct inode *dir,
378 const struct qstr *name, struct page *dpage)
379 {
380 struct page *page;
381 int err;
382
383 if (is_inode_flag_set(inode, FI_NEW_INODE)) {
384 page = new_inode_page(inode);
385 if (IS_ERR(page))
386 return page;
387
388 if (S_ISDIR(inode->i_mode)) {
389 /* in order to handle error case */
390 get_page(page);
391 err = make_empty_dir(inode, dir, page);
392 if (err) {
393 lock_page(page);
394 goto put_error;
395 }
396 put_page(page);
397 }
398
399 err = f2fs_init_acl(inode, dir, page, dpage);
400 if (err)
401 goto put_error;
402
403 err = f2fs_init_security(inode, dir, name, page);
404 if (err)
405 goto put_error;
406
407 if (f2fs_encrypted_inode(dir) && f2fs_may_encrypt(inode)) {
408 err = fscrypt_inherit_context(dir, inode, page, false);
409 if (err)
410 goto put_error;
411 }
412 } else {
413 page = get_node_page(F2FS_I_SB(dir), inode->i_ino);
414 if (IS_ERR(page))
415 return page;
416
417 set_cold_node(inode, page);
418 }
419
420 if (name)
421 init_dent_inode(name, page);
422
423 /*
424 * This file should be checkpointed during fsync.
425 * We lost i_pino from now on.
426 */
427 if (is_inode_flag_set(inode, FI_INC_LINK)) {
428 file_lost_pino(inode);
429 /*
430 * If link the tmpfile to alias through linkat path,
431 * we should remove this inode from orphan list.
432 */
433 if (inode->i_nlink == 0)
434 remove_orphan_inode(F2FS_I_SB(dir), inode->i_ino);
435 f2fs_i_links_write(inode, true);
436 }
437 return page;
438
439 put_error:
440 clear_nlink(inode);
441 update_inode(inode, page);
442 f2fs_put_page(page, 1);
443 return ERR_PTR(err);
444 }
445
446 void update_parent_metadata(struct inode *dir, struct inode *inode,
447 unsigned int current_depth)
448 {
449 if (inode && is_inode_flag_set(inode, FI_NEW_INODE)) {
450 if (S_ISDIR(inode->i_mode))
451 f2fs_i_links_write(dir, true);
452 clear_inode_flag(inode, FI_NEW_INODE);
453 }
454 dir->i_mtime = dir->i_ctime = CURRENT_TIME;
455 f2fs_mark_inode_dirty_sync(dir);
456
457 if (F2FS_I(dir)->i_current_depth != current_depth)
458 f2fs_i_depth_write(dir, current_depth);
459
460 if (inode && is_inode_flag_set(inode, FI_INC_LINK))
461 clear_inode_flag(inode, FI_INC_LINK);
462 }
463
464 int room_for_filename(const void *bitmap, int slots, int max_slots)
465 {
466 int bit_start = 0;
467 int zero_start, zero_end;
468 next:
469 zero_start = find_next_zero_bit_le(bitmap, max_slots, bit_start);
470 if (zero_start >= max_slots)
471 return max_slots;
472
473 zero_end = find_next_bit_le(bitmap, max_slots, zero_start);
474 if (zero_end - zero_start >= slots)
475 return zero_start;
476
477 bit_start = zero_end + 1;
478
479 if (zero_end + 1 >= max_slots)
480 return max_slots;
481 goto next;
482 }
483
484 void f2fs_update_dentry(nid_t ino, umode_t mode, struct f2fs_dentry_ptr *d,
485 const struct qstr *name, f2fs_hash_t name_hash,
486 unsigned int bit_pos)
487 {
488 struct f2fs_dir_entry *de;
489 int slots = GET_DENTRY_SLOTS(name->len);
490 int i;
491
492 de = &d->dentry[bit_pos];
493 de->hash_code = name_hash;
494 de->name_len = cpu_to_le16(name->len);
495 memcpy(d->filename[bit_pos], name->name, name->len);
496 de->ino = cpu_to_le32(ino);
497 set_de_type(de, mode);
498 for (i = 0; i < slots; i++) {
499 test_and_set_bit_le(bit_pos + i, (void *)d->bitmap);
500 /* avoid wrong garbage data for readdir */
501 if (i)
502 (de + i)->name_len = 0;
503 }
504 }
505
506 int f2fs_add_regular_entry(struct inode *dir, const struct qstr *new_name,
507 struct inode *inode, nid_t ino, umode_t mode)
508 {
509 unsigned int bit_pos;
510 unsigned int level;
511 unsigned int current_depth;
512 unsigned long bidx, block;
513 f2fs_hash_t dentry_hash;
514 unsigned int nbucket, nblock;
515 struct page *dentry_page = NULL;
516 struct f2fs_dentry_block *dentry_blk = NULL;
517 struct f2fs_dentry_ptr d;
518 struct page *page = NULL;
519 int slots, err = 0;
520
521 level = 0;
522 slots = GET_DENTRY_SLOTS(new_name->len);
523 dentry_hash = f2fs_dentry_hash(new_name);
524
525 current_depth = F2FS_I(dir)->i_current_depth;
526 if (F2FS_I(dir)->chash == dentry_hash) {
527 level = F2FS_I(dir)->clevel;
528 F2FS_I(dir)->chash = 0;
529 }
530
531 start:
532 #ifdef CONFIG_F2FS_FAULT_INJECTION
533 if (time_to_inject(FAULT_DIR_DEPTH))
534 return -ENOSPC;
535 #endif
536 if (unlikely(current_depth == MAX_DIR_HASH_DEPTH))
537 return -ENOSPC;
538
539 /* Increase the depth, if required */
540 if (level == current_depth)
541 ++current_depth;
542
543 nbucket = dir_buckets(level, F2FS_I(dir)->i_dir_level);
544 nblock = bucket_blocks(level);
545
546 bidx = dir_block_index(level, F2FS_I(dir)->i_dir_level,
547 (le32_to_cpu(dentry_hash) % nbucket));
548
549 for (block = bidx; block <= (bidx + nblock - 1); block++) {
550 dentry_page = get_new_data_page(dir, NULL, block, true);
551 if (IS_ERR(dentry_page))
552 return PTR_ERR(dentry_page);
553
554 dentry_blk = kmap(dentry_page);
555 bit_pos = room_for_filename(&dentry_blk->dentry_bitmap,
556 slots, NR_DENTRY_IN_BLOCK);
557 if (bit_pos < NR_DENTRY_IN_BLOCK)
558 goto add_dentry;
559
560 kunmap(dentry_page);
561 f2fs_put_page(dentry_page, 1);
562 }
563
564 /* Move to next level to find the empty slot for new dentry */
565 ++level;
566 goto start;
567 add_dentry:
568 f2fs_wait_on_page_writeback(dentry_page, DATA, true);
569
570 if (inode) {
571 down_write(&F2FS_I(inode)->i_sem);
572 page = init_inode_metadata(inode, dir, new_name, NULL);
573 if (IS_ERR(page)) {
574 err = PTR_ERR(page);
575 goto fail;
576 }
577 if (f2fs_encrypted_inode(dir))
578 file_set_enc_name(inode);
579 }
580
581 make_dentry_ptr(NULL, &d, (void *)dentry_blk, 1);
582 f2fs_update_dentry(ino, mode, &d, new_name, dentry_hash, bit_pos);
583
584 set_page_dirty(dentry_page);
585
586 if (inode) {
587 f2fs_i_pino_write(inode, dir->i_ino);
588 f2fs_put_page(page, 1);
589 }
590
591 update_parent_metadata(dir, inode, current_depth);
592 fail:
593 if (inode)
594 up_write(&F2FS_I(inode)->i_sem);
595
596 kunmap(dentry_page);
597 f2fs_put_page(dentry_page, 1);
598
599 return err;
600 }
601
602 /*
603 * Caller should grab and release a rwsem by calling f2fs_lock_op() and
604 * f2fs_unlock_op().
605 */
606 int __f2fs_add_link(struct inode *dir, const struct qstr *name,
607 struct inode *inode, nid_t ino, umode_t mode)
608 {
609 struct fscrypt_name fname;
610 struct qstr new_name;
611 int err;
612
613 err = fscrypt_setup_filename(dir, name, 0, &fname);
614 if (err)
615 return err;
616
617 new_name.name = fname_name(&fname);
618 new_name.len = fname_len(&fname);
619
620 err = -EAGAIN;
621 if (f2fs_has_inline_dentry(dir))
622 err = f2fs_add_inline_entry(dir, &new_name, inode, ino, mode);
623 if (err == -EAGAIN)
624 err = f2fs_add_regular_entry(dir, &new_name, inode, ino, mode);
625
626 fscrypt_free_filename(&fname);
627 f2fs_update_time(F2FS_I_SB(dir), REQ_TIME);
628 return err;
629 }
630
631 int f2fs_do_tmpfile(struct inode *inode, struct inode *dir)
632 {
633 struct page *page;
634 int err = 0;
635
636 down_write(&F2FS_I(inode)->i_sem);
637 page = init_inode_metadata(inode, dir, NULL, NULL);
638 if (IS_ERR(page)) {
639 err = PTR_ERR(page);
640 goto fail;
641 }
642 f2fs_put_page(page, 1);
643
644 clear_inode_flag(inode, FI_NEW_INODE);
645 fail:
646 up_write(&F2FS_I(inode)->i_sem);
647 f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
648 return err;
649 }
650
651 void f2fs_drop_nlink(struct inode *dir, struct inode *inode)
652 {
653 struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
654
655 down_write(&F2FS_I(inode)->i_sem);
656
657 if (S_ISDIR(inode->i_mode))
658 f2fs_i_links_write(dir, false);
659 inode->i_ctime = CURRENT_TIME;
660
661 f2fs_i_links_write(inode, false);
662 if (S_ISDIR(inode->i_mode)) {
663 f2fs_i_links_write(inode, false);
664 f2fs_i_size_write(inode, 0);
665 }
666 up_write(&F2FS_I(inode)->i_sem);
667
668 if (inode->i_nlink == 0)
669 add_orphan_inode(inode);
670 else
671 release_orphan_inode(sbi);
672 }
673
674 /*
675 * It only removes the dentry from the dentry page, corresponding name
676 * entry in name page does not need to be touched during deletion.
677 */
678 void f2fs_delete_entry(struct f2fs_dir_entry *dentry, struct page *page,
679 struct inode *dir, struct inode *inode)
680 {
681 struct f2fs_dentry_block *dentry_blk;
682 unsigned int bit_pos;
683 int slots = GET_DENTRY_SLOTS(le16_to_cpu(dentry->name_len));
684 int i;
685
686 f2fs_update_time(F2FS_I_SB(dir), REQ_TIME);
687
688 if (f2fs_has_inline_dentry(dir))
689 return f2fs_delete_inline_entry(dentry, page, dir, inode);
690
691 lock_page(page);
692 f2fs_wait_on_page_writeback(page, DATA, true);
693
694 dentry_blk = page_address(page);
695 bit_pos = dentry - dentry_blk->dentry;
696 for (i = 0; i < slots; i++)
697 clear_bit_le(bit_pos + i, &dentry_blk->dentry_bitmap);
698
699 /* Let's check and deallocate this dentry page */
700 bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
701 NR_DENTRY_IN_BLOCK,
702 0);
703 kunmap(page); /* kunmap - pair of f2fs_find_entry */
704 set_page_dirty(page);
705
706 dir->i_ctime = dir->i_mtime = CURRENT_TIME;
707 f2fs_mark_inode_dirty_sync(dir);
708
709 if (inode)
710 f2fs_drop_nlink(dir, inode);
711
712 if (bit_pos == NR_DENTRY_IN_BLOCK &&
713 !truncate_hole(dir, page->index, page->index + 1)) {
714 clear_page_dirty_for_io(page);
715 ClearPagePrivate(page);
716 ClearPageUptodate(page);
717 inode_dec_dirty_pages(dir);
718 }
719 f2fs_put_page(page, 1);
720 }
721
722 bool f2fs_empty_dir(struct inode *dir)
723 {
724 unsigned long bidx;
725 struct page *dentry_page;
726 unsigned int bit_pos;
727 struct f2fs_dentry_block *dentry_blk;
728 unsigned long nblock = dir_blocks(dir);
729
730 if (f2fs_has_inline_dentry(dir))
731 return f2fs_empty_inline_dir(dir);
732
733 for (bidx = 0; bidx < nblock; bidx++) {
734 dentry_page = get_lock_data_page(dir, bidx, false);
735 if (IS_ERR(dentry_page)) {
736 if (PTR_ERR(dentry_page) == -ENOENT)
737 continue;
738 else
739 return false;
740 }
741
742 dentry_blk = kmap_atomic(dentry_page);
743 if (bidx == 0)
744 bit_pos = 2;
745 else
746 bit_pos = 0;
747 bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
748 NR_DENTRY_IN_BLOCK,
749 bit_pos);
750 kunmap_atomic(dentry_blk);
751
752 f2fs_put_page(dentry_page, 1);
753
754 if (bit_pos < NR_DENTRY_IN_BLOCK)
755 return false;
756 }
757 return true;
758 }
759
760 bool f2fs_fill_dentries(struct dir_context *ctx, struct f2fs_dentry_ptr *d,
761 unsigned int start_pos, struct fscrypt_str *fstr)
762 {
763 unsigned char d_type = DT_UNKNOWN;
764 unsigned int bit_pos;
765 struct f2fs_dir_entry *de = NULL;
766 struct fscrypt_str de_name = FSTR_INIT(NULL, 0);
767
768 bit_pos = ((unsigned long)ctx->pos % d->max);
769
770 while (bit_pos < d->max) {
771 bit_pos = find_next_bit_le(d->bitmap, d->max, bit_pos);
772 if (bit_pos >= d->max)
773 break;
774
775 de = &d->dentry[bit_pos];
776 if (de->name_len == 0) {
777 bit_pos++;
778 ctx->pos = start_pos + bit_pos;
779 continue;
780 }
781
782 d_type = get_de_type(de);
783
784 de_name.name = d->filename[bit_pos];
785 de_name.len = le16_to_cpu(de->name_len);
786
787 if (f2fs_encrypted_inode(d->inode)) {
788 int save_len = fstr->len;
789 int ret;
790
791 de_name.name = f2fs_kmalloc(de_name.len, GFP_NOFS);
792 if (!de_name.name)
793 return false;
794
795 memcpy(de_name.name, d->filename[bit_pos], de_name.len);
796
797 ret = fscrypt_fname_disk_to_usr(d->inode,
798 (u32)de->hash_code, 0,
799 &de_name, fstr);
800 kfree(de_name.name);
801 if (ret < 0)
802 return true;
803
804 de_name = *fstr;
805 fstr->len = save_len;
806 }
807
808 if (!dir_emit(ctx, de_name.name, de_name.len,
809 le32_to_cpu(de->ino), d_type))
810 return true;
811
812 bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
813 ctx->pos = start_pos + bit_pos;
814 }
815 return false;
816 }
817
818 static int f2fs_readdir(struct file *file, struct dir_context *ctx)
819 {
820 struct inode *inode = file_inode(file);
821 unsigned long npages = dir_blocks(inode);
822 struct f2fs_dentry_block *dentry_blk = NULL;
823 struct page *dentry_page = NULL;
824 struct file_ra_state *ra = &file->f_ra;
825 unsigned int n = ((unsigned long)ctx->pos / NR_DENTRY_IN_BLOCK);
826 struct f2fs_dentry_ptr d;
827 struct fscrypt_str fstr = FSTR_INIT(NULL, 0);
828 int err = 0;
829
830 if (f2fs_encrypted_inode(inode)) {
831 err = fscrypt_get_encryption_info(inode);
832 if (err && err != -ENOKEY)
833 return err;
834
835 err = fscrypt_fname_alloc_buffer(inode, F2FS_NAME_LEN, &fstr);
836 if (err < 0)
837 return err;
838 }
839
840 if (f2fs_has_inline_dentry(inode)) {
841 err = f2fs_read_inline_dir(file, ctx, &fstr);
842 goto out;
843 }
844
845 /* readahead for multi pages of dir */
846 if (npages - n > 1 && !ra_has_index(ra, n))
847 page_cache_sync_readahead(inode->i_mapping, ra, file, n,
848 min(npages - n, (pgoff_t)MAX_DIR_RA_PAGES));
849
850 for (; n < npages; n++) {
851 dentry_page = get_lock_data_page(inode, n, false);
852 if (IS_ERR(dentry_page)) {
853 err = PTR_ERR(dentry_page);
854 if (err == -ENOENT)
855 continue;
856 else
857 goto out;
858 }
859
860 dentry_blk = kmap(dentry_page);
861
862 make_dentry_ptr(inode, &d, (void *)dentry_blk, 1);
863
864 if (f2fs_fill_dentries(ctx, &d, n * NR_DENTRY_IN_BLOCK, &fstr)) {
865 kunmap(dentry_page);
866 f2fs_put_page(dentry_page, 1);
867 break;
868 }
869
870 ctx->pos = (n + 1) * NR_DENTRY_IN_BLOCK;
871 kunmap(dentry_page);
872 f2fs_put_page(dentry_page, 1);
873 }
874 err = 0;
875 out:
876 fscrypt_fname_free_buffer(&fstr);
877 return err;
878 }
879
880 static int f2fs_dir_open(struct inode *inode, struct file *filp)
881 {
882 if (f2fs_encrypted_inode(inode))
883 return fscrypt_get_encryption_info(inode) ? -EACCES : 0;
884 return 0;
885 }
886
887 const struct file_operations f2fs_dir_operations = {
888 .llseek = generic_file_llseek,
889 .read = generic_read_dir,
890 .iterate_shared = f2fs_readdir,
891 .fsync = f2fs_sync_file,
892 .open = f2fs_dir_open,
893 .unlocked_ioctl = f2fs_ioctl,
894 #ifdef CONFIG_COMPAT
895 .compat_ioctl = f2fs_compat_ioctl,
896 #endif
897 };
Linux kernel - Deliverables
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