1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * fs/f2fs/dir.c
4 *
5 * Copyright (c) 2012 Samsung Electronics Co., Ltd.
6 * http://www.samsung.com/
7 */
8 #include <asm/unaligned.h>
9 #include <linux/fs.h>
10 #include <linux/f2fs_fs.h>
11 #include <linux/sched/signal.h>
12 #include <linux/unicode.h>
13 #include "f2fs.h"
14 #include "node.h"
15 #include "acl.h"
16 #include "xattr.h"
17 #include <trace/events/f2fs.h>
18
19 #if IS_ENABLED(CONFIG_UNICODE)
20 extern struct kmem_cache *f2fs_cf_name_slab;
21 #endif
22
dir_blocks(struct inode * inode)23 static unsigned long dir_blocks(struct inode *inode)
24 {
25 return ((unsigned long long) (i_size_read(inode) + PAGE_SIZE - 1))
26 >> PAGE_SHIFT;
27 }
28
dir_buckets(unsigned int level,int dir_level)29 static unsigned int dir_buckets(unsigned int level, int dir_level)
30 {
31 if (level + dir_level < MAX_DIR_HASH_DEPTH / 2)
32 return BIT(level + dir_level);
33 else
34 return MAX_DIR_BUCKETS;
35 }
36
bucket_blocks(unsigned int level)37 static unsigned int bucket_blocks(unsigned int level)
38 {
39 if (level < MAX_DIR_HASH_DEPTH / 2)
40 return 2;
41 else
42 return 4;
43 }
44
45 #if IS_ENABLED(CONFIG_UNICODE)
46 /* If @dir is casefolded, initialize @fname->cf_name from @fname->usr_fname. */
f2fs_init_casefolded_name(const struct inode * dir,struct f2fs_filename * fname)47 int f2fs_init_casefolded_name(const struct inode *dir,
48 struct f2fs_filename *fname)
49 {
50 struct super_block *sb = dir->i_sb;
51 unsigned char *buf;
52 int len;
53
54 if (IS_CASEFOLDED(dir) &&
55 !is_dot_dotdot(fname->usr_fname->name, fname->usr_fname->len)) {
56 buf = f2fs_kmem_cache_alloc(f2fs_cf_name_slab,
57 GFP_NOFS, false, F2FS_SB(sb));
58 if (!buf)
59 return -ENOMEM;
60
61 len = utf8_casefold(sb->s_encoding, fname->usr_fname,
62 buf, F2FS_NAME_LEN);
63 if (len <= 0) {
64 kmem_cache_free(f2fs_cf_name_slab, buf);
65 if (sb_has_strict_encoding(sb))
66 return -EINVAL;
67 /* fall back to treating name as opaque byte sequence */
68 return 0;
69 }
70 fname->cf_name.name = buf;
71 fname->cf_name.len = len;
72 }
73
74 return 0;
75 }
76
f2fs_free_casefolded_name(struct f2fs_filename * fname)77 void f2fs_free_casefolded_name(struct f2fs_filename *fname)
78 {
79 unsigned char *buf = (unsigned char *)fname->cf_name.name;
80
81 if (buf) {
82 kmem_cache_free(f2fs_cf_name_slab, buf);
83 fname->cf_name.name = NULL;
84 }
85 }
86 #endif /* CONFIG_UNICODE */
87
__f2fs_setup_filename(const struct inode * dir,const struct fscrypt_name * crypt_name,struct f2fs_filename * fname)88 static int __f2fs_setup_filename(const struct inode *dir,
89 const struct fscrypt_name *crypt_name,
90 struct f2fs_filename *fname)
91 {
92 int err;
93
94 memset(fname, 0, sizeof(*fname));
95
96 fname->usr_fname = crypt_name->usr_fname;
97 fname->disk_name = crypt_name->disk_name;
98 #ifdef CONFIG_FS_ENCRYPTION
99 fname->crypto_buf = crypt_name->crypto_buf;
100 #endif
101 if (crypt_name->is_nokey_name) {
102 /* hash was decoded from the no-key name */
103 fname->hash = cpu_to_le32(crypt_name->hash);
104 } else {
105 err = f2fs_init_casefolded_name(dir, fname);
106 if (err) {
107 f2fs_free_filename(fname);
108 return err;
109 }
110 f2fs_hash_filename(dir, fname);
111 }
112 return 0;
113 }
114
115 /*
116 * Prepare to search for @iname in @dir. This is similar to
117 * fscrypt_setup_filename(), but this also handles computing the casefolded name
118 * and the f2fs dirhash if needed, then packing all the information about this
119 * filename up into a 'struct f2fs_filename'.
120 */
f2fs_setup_filename(struct inode * dir,const struct qstr * iname,int lookup,struct f2fs_filename * fname)121 int f2fs_setup_filename(struct inode *dir, const struct qstr *iname,
122 int lookup, struct f2fs_filename *fname)
123 {
124 struct fscrypt_name crypt_name;
125 int err;
126
127 err = fscrypt_setup_filename(dir, iname, lookup, &crypt_name);
128 if (err)
129 return err;
130
131 return __f2fs_setup_filename(dir, &crypt_name, fname);
132 }
133
134 /*
135 * Prepare to look up @dentry in @dir. This is similar to
136 * fscrypt_prepare_lookup(), but this also handles computing the casefolded name
137 * and the f2fs dirhash if needed, then packing all the information about this
138 * filename up into a 'struct f2fs_filename'.
139 */
f2fs_prepare_lookup(struct inode * dir,struct dentry * dentry,struct f2fs_filename * fname)140 int f2fs_prepare_lookup(struct inode *dir, struct dentry *dentry,
141 struct f2fs_filename *fname)
142 {
143 struct fscrypt_name crypt_name;
144 int err;
145
146 err = fscrypt_prepare_lookup(dir, dentry, &crypt_name);
147 if (err)
148 return err;
149
150 return __f2fs_setup_filename(dir, &crypt_name, fname);
151 }
152
f2fs_free_filename(struct f2fs_filename * fname)153 void f2fs_free_filename(struct f2fs_filename *fname)
154 {
155 #ifdef CONFIG_FS_ENCRYPTION
156 kfree(fname->crypto_buf.name);
157 fname->crypto_buf.name = NULL;
158 #endif
159 f2fs_free_casefolded_name(fname);
160 }
161
dir_block_index(unsigned int level,int dir_level,unsigned int idx)162 static unsigned long dir_block_index(unsigned int level,
163 int dir_level, unsigned int idx)
164 {
165 unsigned long i;
166 unsigned long bidx = 0;
167
168 for (i = 0; i < level; i++)
169 bidx += dir_buckets(i, dir_level) * bucket_blocks(i);
170 bidx += idx * bucket_blocks(level);
171 return bidx;
172 }
173
find_in_block(struct inode * dir,struct page * dentry_page,const struct f2fs_filename * fname,int * max_slots)174 static struct f2fs_dir_entry *find_in_block(struct inode *dir,
175 struct page *dentry_page,
176 const struct f2fs_filename *fname,
177 int *max_slots)
178 {
179 struct f2fs_dentry_block *dentry_blk;
180 struct f2fs_dentry_ptr d;
181
182 dentry_blk = (struct f2fs_dentry_block *)page_address(dentry_page);
183
184 make_dentry_ptr_block(dir, &d, dentry_blk);
185 return f2fs_find_target_dentry(&d, fname, max_slots);
186 }
187
f2fs_match_name(const struct inode * dir,const struct f2fs_filename * fname,const u8 * de_name,u32 de_name_len)188 static inline int f2fs_match_name(const struct inode *dir,
189 const struct f2fs_filename *fname,
190 const u8 *de_name, u32 de_name_len)
191 {
192 struct fscrypt_name f;
193
194 #if IS_ENABLED(CONFIG_UNICODE)
195 if (fname->cf_name.name)
196 return generic_ci_match(dir, fname->usr_fname,
197 &fname->cf_name,
198 de_name, de_name_len);
199
200 #endif
201 f.usr_fname = fname->usr_fname;
202 f.disk_name = fname->disk_name;
203 #ifdef CONFIG_FS_ENCRYPTION
204 f.crypto_buf = fname->crypto_buf;
205 #endif
206 return fscrypt_match_name(&f, de_name, de_name_len);
207 }
208
f2fs_find_target_dentry(const struct f2fs_dentry_ptr * d,const struct f2fs_filename * fname,int * max_slots)209 struct f2fs_dir_entry *f2fs_find_target_dentry(const struct f2fs_dentry_ptr *d,
210 const struct f2fs_filename *fname, int *max_slots)
211 {
212 struct f2fs_dir_entry *de;
213 unsigned long bit_pos = 0;
214 int max_len = 0;
215 int res = 0;
216
217 if (max_slots)
218 *max_slots = 0;
219 while (bit_pos < d->max) {
220 if (!test_bit_le(bit_pos, d->bitmap)) {
221 bit_pos++;
222 max_len++;
223 continue;
224 }
225
226 de = &d->dentry[bit_pos];
227
228 if (unlikely(!de->name_len)) {
229 bit_pos++;
230 continue;
231 }
232
233 if (de->hash_code == fname->hash) {
234 res = f2fs_match_name(d->inode, fname,
235 d->filename[bit_pos],
236 le16_to_cpu(de->name_len));
237 if (res < 0)
238 return ERR_PTR(res);
239 if (res)
240 goto found;
241 }
242
243 if (max_slots && max_len > *max_slots)
244 *max_slots = max_len;
245 max_len = 0;
246
247 bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
248 }
249
250 de = NULL;
251 found:
252 if (max_slots && max_len > *max_slots)
253 *max_slots = max_len;
254 return de;
255 }
256
find_in_level(struct inode * dir,unsigned int level,const struct f2fs_filename * fname,struct page ** res_page)257 static struct f2fs_dir_entry *find_in_level(struct inode *dir,
258 unsigned int level,
259 const struct f2fs_filename *fname,
260 struct page **res_page)
261 {
262 int s = GET_DENTRY_SLOTS(fname->disk_name.len);
263 unsigned int nbucket, nblock;
264 unsigned int bidx, end_block;
265 struct page *dentry_page;
266 struct f2fs_dir_entry *de = NULL;
267 pgoff_t next_pgofs;
268 bool room = false;
269 int max_slots;
270
271 nbucket = dir_buckets(level, F2FS_I(dir)->i_dir_level);
272 nblock = bucket_blocks(level);
273
274 bidx = dir_block_index(level, F2FS_I(dir)->i_dir_level,
275 le32_to_cpu(fname->hash) % nbucket);
276 end_block = bidx + nblock;
277
278 while (bidx < end_block) {
279 /* no need to allocate new dentry pages to all the indices */
280 dentry_page = f2fs_find_data_page(dir, bidx, &next_pgofs);
281 if (IS_ERR(dentry_page)) {
282 if (PTR_ERR(dentry_page) == -ENOENT) {
283 room = true;
284 bidx = next_pgofs;
285 continue;
286 } else {
287 *res_page = dentry_page;
288 break;
289 }
290 }
291
292 de = find_in_block(dir, dentry_page, fname, &max_slots);
293 if (IS_ERR(de)) {
294 *res_page = ERR_CAST(de);
295 de = NULL;
296 break;
297 } else if (de) {
298 *res_page = dentry_page;
299 break;
300 }
301
302 if (max_slots >= s)
303 room = true;
304 f2fs_put_page(dentry_page, 0);
305
306 bidx++;
307 }
308
309 if (!de && room && F2FS_I(dir)->chash != fname->hash) {
310 F2FS_I(dir)->chash = fname->hash;
311 F2FS_I(dir)->clevel = level;
312 }
313
314 return de;
315 }
316
__f2fs_find_entry(struct inode * dir,const struct f2fs_filename * fname,struct page ** res_page)317 struct f2fs_dir_entry *__f2fs_find_entry(struct inode *dir,
318 const struct f2fs_filename *fname,
319 struct page **res_page)
320 {
321 unsigned long npages = dir_blocks(dir);
322 struct f2fs_dir_entry *de = NULL;
323 unsigned int max_depth;
324 unsigned int level;
325
326 *res_page = NULL;
327
328 if (f2fs_has_inline_dentry(dir)) {
329 de = f2fs_find_in_inline_dir(dir, fname, res_page);
330 goto out;
331 }
332
333 if (npages == 0)
334 goto out;
335
336 max_depth = F2FS_I(dir)->i_current_depth;
337 if (unlikely(max_depth > MAX_DIR_HASH_DEPTH)) {
338 f2fs_warn(F2FS_I_SB(dir), "Corrupted max_depth of %lu: %u",
339 dir->i_ino, max_depth);
340 max_depth = MAX_DIR_HASH_DEPTH;
341 f2fs_i_depth_write(dir, max_depth);
342 }
343
344 for (level = 0; level < max_depth; level++) {
345 de = find_in_level(dir, level, fname, res_page);
346 if (de || IS_ERR(*res_page))
347 break;
348 }
349 out:
350 /* This is to increase the speed of f2fs_create */
351 if (!de)
352 F2FS_I(dir)->task = current;
353 return de;
354 }
355
356 /*
357 * Find an entry in the specified directory with the wanted name.
358 * It returns the page where the entry was found (as a parameter - res_page),
359 * and the entry itself. Page is returned mapped and unlocked.
360 * Entry is guaranteed to be valid.
361 */
f2fs_find_entry(struct inode * dir,const struct qstr * child,struct page ** res_page)362 struct f2fs_dir_entry *f2fs_find_entry(struct inode *dir,
363 const struct qstr *child, struct page **res_page)
364 {
365 struct f2fs_dir_entry *de = NULL;
366 struct f2fs_filename fname;
367 int err;
368
369 err = f2fs_setup_filename(dir, child, 1, &fname);
370 if (err) {
371 if (err == -ENOENT)
372 *res_page = NULL;
373 else
374 *res_page = ERR_PTR(err);
375 return NULL;
376 }
377
378 de = __f2fs_find_entry(dir, &fname, res_page);
379
380 f2fs_free_filename(&fname);
381 return de;
382 }
383
f2fs_parent_dir(struct inode * dir,struct page ** p)384 struct f2fs_dir_entry *f2fs_parent_dir(struct inode *dir, struct page **p)
385 {
386 return f2fs_find_entry(dir, &dotdot_name, p);
387 }
388
f2fs_inode_by_name(struct inode * dir,const struct qstr * qstr,struct page ** page)389 ino_t f2fs_inode_by_name(struct inode *dir, const struct qstr *qstr,
390 struct page **page)
391 {
392 ino_t res = 0;
393 struct f2fs_dir_entry *de;
394
395 de = f2fs_find_entry(dir, qstr, page);
396 if (de) {
397 res = le32_to_cpu(de->ino);
398 f2fs_put_page(*page, 0);
399 }
400
401 return res;
402 }
403
f2fs_set_link(struct inode * dir,struct f2fs_dir_entry * de,struct page * page,struct inode * inode)404 void f2fs_set_link(struct inode *dir, struct f2fs_dir_entry *de,
405 struct page *page, struct inode *inode)
406 {
407 enum page_type type = f2fs_has_inline_dentry(dir) ? NODE : DATA;
408
409 lock_page(page);
410 f2fs_wait_on_page_writeback(page, type, true, true);
411 de->ino = cpu_to_le32(inode->i_ino);
412 de->file_type = fs_umode_to_ftype(inode->i_mode);
413 set_page_dirty(page);
414
415 inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
416 f2fs_mark_inode_dirty_sync(dir, false);
417 f2fs_put_page(page, 1);
418 }
419
init_dent_inode(struct inode * dir,struct inode * inode,const struct f2fs_filename * fname,struct page * ipage)420 static void init_dent_inode(struct inode *dir, struct inode *inode,
421 const struct f2fs_filename *fname,
422 struct page *ipage)
423 {
424 struct f2fs_inode *ri;
425
426 if (!fname) /* tmpfile case? */
427 return;
428
429 f2fs_wait_on_page_writeback(ipage, NODE, true, true);
430
431 /* copy name info. to this inode page */
432 ri = F2FS_INODE(ipage);
433 ri->i_namelen = cpu_to_le32(fname->disk_name.len);
434 memcpy(ri->i_name, fname->disk_name.name, fname->disk_name.len);
435 if (IS_ENCRYPTED(dir)) {
436 file_set_enc_name(inode);
437 /*
438 * Roll-forward recovery doesn't have encryption keys available,
439 * so it can't compute the dirhash for encrypted+casefolded
440 * filenames. Append it to i_name if possible. Else, disable
441 * roll-forward recovery of the dentry (i.e., make fsync'ing the
442 * file force a checkpoint) by setting LOST_PINO.
443 */
444 if (IS_CASEFOLDED(dir)) {
445 if (fname->disk_name.len + sizeof(f2fs_hash_t) <=
446 F2FS_NAME_LEN)
447 put_unaligned(fname->hash, (f2fs_hash_t *)
448 &ri->i_name[fname->disk_name.len]);
449 else
450 file_lost_pino(inode);
451 }
452 }
453 set_page_dirty(ipage);
454 }
455
f2fs_do_make_empty_dir(struct inode * inode,struct inode * parent,struct f2fs_dentry_ptr * d)456 void f2fs_do_make_empty_dir(struct inode *inode, struct inode *parent,
457 struct f2fs_dentry_ptr *d)
458 {
459 struct fscrypt_str dot = FSTR_INIT(".", 1);
460 struct fscrypt_str dotdot = FSTR_INIT("..", 2);
461
462 /* update dirent of "." */
463 f2fs_update_dentry(inode->i_ino, inode->i_mode, d, &dot, 0, 0);
464
465 /* update dirent of ".." */
466 f2fs_update_dentry(parent->i_ino, parent->i_mode, d, &dotdot, 0, 1);
467 }
468
make_empty_dir(struct inode * inode,struct inode * parent,struct page * page)469 static int make_empty_dir(struct inode *inode,
470 struct inode *parent, struct page *page)
471 {
472 struct page *dentry_page;
473 struct f2fs_dentry_block *dentry_blk;
474 struct f2fs_dentry_ptr d;
475
476 if (f2fs_has_inline_dentry(inode))
477 return f2fs_make_empty_inline_dir(inode, parent, page);
478
479 dentry_page = f2fs_get_new_data_page(inode, page, 0, true);
480 if (IS_ERR(dentry_page))
481 return PTR_ERR(dentry_page);
482
483 dentry_blk = page_address(dentry_page);
484
485 make_dentry_ptr_block(NULL, &d, dentry_blk);
486 f2fs_do_make_empty_dir(inode, parent, &d);
487
488 set_page_dirty(dentry_page);
489 f2fs_put_page(dentry_page, 1);
490 return 0;
491 }
492
f2fs_init_inode_metadata(struct inode * inode,struct inode * dir,const struct f2fs_filename * fname,struct page * dpage)493 struct page *f2fs_init_inode_metadata(struct inode *inode, struct inode *dir,
494 const struct f2fs_filename *fname, struct page *dpage)
495 {
496 struct page *page;
497 int err;
498
499 if (is_inode_flag_set(inode, FI_NEW_INODE)) {
500 page = f2fs_new_inode_page(inode);
501 if (IS_ERR(page))
502 return page;
503
504 if (S_ISDIR(inode->i_mode)) {
505 /* in order to handle error case */
506 get_page(page);
507 err = make_empty_dir(inode, dir, page);
508 if (err) {
509 lock_page(page);
510 goto put_error;
511 }
512 put_page(page);
513 }
514
515 err = f2fs_init_acl(inode, dir, page, dpage);
516 if (err)
517 goto put_error;
518
519 err = f2fs_init_security(inode, dir,
520 fname ? fname->usr_fname : NULL, page);
521 if (err)
522 goto put_error;
523
524 if (IS_ENCRYPTED(inode)) {
525 err = fscrypt_set_context(inode, page);
526 if (err)
527 goto put_error;
528 }
529 } else {
530 page = f2fs_get_node_page(F2FS_I_SB(dir), inode->i_ino);
531 if (IS_ERR(page))
532 return page;
533 }
534
535 init_dent_inode(dir, inode, fname, page);
536
537 /*
538 * This file should be checkpointed during fsync.
539 * We lost i_pino from now on.
540 */
541 if (is_inode_flag_set(inode, FI_INC_LINK)) {
542 if (!S_ISDIR(inode->i_mode))
543 file_lost_pino(inode);
544 /*
545 * If link the tmpfile to alias through linkat path,
546 * we should remove this inode from orphan list.
547 */
548 if (inode->i_nlink == 0)
549 f2fs_remove_orphan_inode(F2FS_I_SB(dir), inode->i_ino);
550 f2fs_i_links_write(inode, true);
551 }
552 return page;
553
554 put_error:
555 clear_nlink(inode);
556 f2fs_update_inode(inode, page);
557 f2fs_put_page(page, 1);
558 return ERR_PTR(err);
559 }
560
f2fs_update_parent_metadata(struct inode * dir,struct inode * inode,unsigned int current_depth)561 void f2fs_update_parent_metadata(struct inode *dir, struct inode *inode,
562 unsigned int current_depth)
563 {
564 if (inode && is_inode_flag_set(inode, FI_NEW_INODE)) {
565 if (S_ISDIR(inode->i_mode))
566 f2fs_i_links_write(dir, true);
567 clear_inode_flag(inode, FI_NEW_INODE);
568 }
569 inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
570 f2fs_mark_inode_dirty_sync(dir, false);
571
572 if (F2FS_I(dir)->i_current_depth != current_depth)
573 f2fs_i_depth_write(dir, current_depth);
574
575 if (inode && is_inode_flag_set(inode, FI_INC_LINK))
576 clear_inode_flag(inode, FI_INC_LINK);
577 }
578
f2fs_room_for_filename(const void * bitmap,int slots,int max_slots)579 int f2fs_room_for_filename(const void *bitmap, int slots, int max_slots)
580 {
581 int bit_start = 0;
582 int zero_start, zero_end;
583 next:
584 zero_start = find_next_zero_bit_le(bitmap, max_slots, bit_start);
585 if (zero_start >= max_slots)
586 return max_slots;
587
588 zero_end = find_next_bit_le(bitmap, max_slots, zero_start);
589 if (zero_end - zero_start >= slots)
590 return zero_start;
591
592 bit_start = zero_end + 1;
593
594 if (zero_end + 1 >= max_slots)
595 return max_slots;
596 goto next;
597 }
598
f2fs_has_enough_room(struct inode * dir,struct page * ipage,const struct f2fs_filename * fname)599 bool f2fs_has_enough_room(struct inode *dir, struct page *ipage,
600 const struct f2fs_filename *fname)
601 {
602 struct f2fs_dentry_ptr d;
603 unsigned int bit_pos;
604 int slots = GET_DENTRY_SLOTS(fname->disk_name.len);
605
606 make_dentry_ptr_inline(dir, &d, inline_data_addr(dir, ipage));
607
608 bit_pos = f2fs_room_for_filename(d.bitmap, slots, d.max);
609
610 return bit_pos < d.max;
611 }
612
f2fs_update_dentry(nid_t ino,umode_t mode,struct f2fs_dentry_ptr * d,const struct fscrypt_str * name,f2fs_hash_t name_hash,unsigned int bit_pos)613 void f2fs_update_dentry(nid_t ino, umode_t mode, struct f2fs_dentry_ptr *d,
614 const struct fscrypt_str *name, f2fs_hash_t name_hash,
615 unsigned int bit_pos)
616 {
617 struct f2fs_dir_entry *de;
618 int slots = GET_DENTRY_SLOTS(name->len);
619 int i;
620
621 de = &d->dentry[bit_pos];
622 de->hash_code = name_hash;
623 de->name_len = cpu_to_le16(name->len);
624 memcpy(d->filename[bit_pos], name->name, name->len);
625 de->ino = cpu_to_le32(ino);
626 de->file_type = fs_umode_to_ftype(mode);
627 for (i = 0; i < slots; i++) {
628 __set_bit_le(bit_pos + i, (void *)d->bitmap);
629 /* avoid wrong garbage data for readdir */
630 if (i)
631 (de + i)->name_len = 0;
632 }
633 }
634
f2fs_add_regular_entry(struct inode * dir,const struct f2fs_filename * fname,struct inode * inode,nid_t ino,umode_t mode)635 int f2fs_add_regular_entry(struct inode *dir, const struct f2fs_filename *fname,
636 struct inode *inode, nid_t ino, umode_t mode)
637 {
638 unsigned int bit_pos;
639 unsigned int level;
640 unsigned int current_depth;
641 unsigned long bidx, block;
642 unsigned int nbucket, nblock;
643 struct page *dentry_page = NULL;
644 struct f2fs_dentry_block *dentry_blk = NULL;
645 struct f2fs_dentry_ptr d;
646 struct page *page = NULL;
647 int slots, err = 0;
648
649 level = 0;
650 slots = GET_DENTRY_SLOTS(fname->disk_name.len);
651
652 current_depth = F2FS_I(dir)->i_current_depth;
653 if (F2FS_I(dir)->chash == fname->hash) {
654 level = F2FS_I(dir)->clevel;
655 F2FS_I(dir)->chash = 0;
656 }
657
658 start:
659 if (time_to_inject(F2FS_I_SB(dir), FAULT_DIR_DEPTH))
660 return -ENOSPC;
661
662 if (unlikely(current_depth == MAX_DIR_HASH_DEPTH))
663 return -ENOSPC;
664
665 /* Increase the depth, if required */
666 if (level == current_depth)
667 ++current_depth;
668
669 nbucket = dir_buckets(level, F2FS_I(dir)->i_dir_level);
670 nblock = bucket_blocks(level);
671
672 bidx = dir_block_index(level, F2FS_I(dir)->i_dir_level,
673 (le32_to_cpu(fname->hash) % nbucket));
674
675 for (block = bidx; block <= (bidx + nblock - 1); block++) {
676 dentry_page = f2fs_get_new_data_page(dir, NULL, block, true);
677 if (IS_ERR(dentry_page))
678 return PTR_ERR(dentry_page);
679
680 dentry_blk = page_address(dentry_page);
681 bit_pos = f2fs_room_for_filename(&dentry_blk->dentry_bitmap,
682 slots, NR_DENTRY_IN_BLOCK);
683 if (bit_pos < NR_DENTRY_IN_BLOCK)
684 goto add_dentry;
685
686 f2fs_put_page(dentry_page, 1);
687 }
688
689 /* Move to next level to find the empty slot for new dentry */
690 ++level;
691 goto start;
692 add_dentry:
693 f2fs_wait_on_page_writeback(dentry_page, DATA, true, true);
694
695 if (inode) {
696 f2fs_down_write(&F2FS_I(inode)->i_sem);
697 page = f2fs_init_inode_metadata(inode, dir, fname, NULL);
698 if (IS_ERR(page)) {
699 err = PTR_ERR(page);
700 goto fail;
701 }
702 }
703
704 make_dentry_ptr_block(NULL, &d, dentry_blk);
705 f2fs_update_dentry(ino, mode, &d, &fname->disk_name, fname->hash,
706 bit_pos);
707
708 set_page_dirty(dentry_page);
709
710 if (inode) {
711 f2fs_i_pino_write(inode, dir->i_ino);
712
713 /* synchronize inode page's data from inode cache */
714 if (is_inode_flag_set(inode, FI_NEW_INODE))
715 f2fs_update_inode(inode, page);
716
717 f2fs_put_page(page, 1);
718 }
719
720 f2fs_update_parent_metadata(dir, inode, current_depth);
721 fail:
722 if (inode)
723 f2fs_up_write(&F2FS_I(inode)->i_sem);
724
725 f2fs_put_page(dentry_page, 1);
726
727 return err;
728 }
729
f2fs_add_dentry(struct inode * dir,const struct f2fs_filename * fname,struct inode * inode,nid_t ino,umode_t mode)730 int f2fs_add_dentry(struct inode *dir, const struct f2fs_filename *fname,
731 struct inode *inode, nid_t ino, umode_t mode)
732 {
733 int err = -EAGAIN;
734
735 if (f2fs_has_inline_dentry(dir)) {
736 /*
737 * Should get i_xattr_sem to keep the lock order:
738 * i_xattr_sem -> inode_page lock used by f2fs_setxattr.
739 */
740 f2fs_down_read(&F2FS_I(dir)->i_xattr_sem);
741 err = f2fs_add_inline_entry(dir, fname, inode, ino, mode);
742 f2fs_up_read(&F2FS_I(dir)->i_xattr_sem);
743 }
744 if (err == -EAGAIN)
745 err = f2fs_add_regular_entry(dir, fname, inode, ino, mode);
746
747 f2fs_update_time(F2FS_I_SB(dir), REQ_TIME);
748 return err;
749 }
750
751 /*
752 * Caller should grab and release a rwsem by calling f2fs_lock_op() and
753 * f2fs_unlock_op().
754 */
f2fs_do_add_link(struct inode * dir,const struct qstr * name,struct inode * inode,nid_t ino,umode_t mode)755 int f2fs_do_add_link(struct inode *dir, const struct qstr *name,
756 struct inode *inode, nid_t ino, umode_t mode)
757 {
758 struct f2fs_filename fname;
759 struct page *page = NULL;
760 struct f2fs_dir_entry *de = NULL;
761 int err;
762
763 err = f2fs_setup_filename(dir, name, 0, &fname);
764 if (err)
765 return err;
766
767 /*
768 * An immature stackable filesystem shows a race condition between lookup
769 * and create. If we have same task when doing lookup and create, it's
770 * definitely fine as expected by VFS normally. Otherwise, let's just
771 * verify on-disk dentry one more time, which guarantees filesystem
772 * consistency more.
773 */
774 if (current != F2FS_I(dir)->task) {
775 de = __f2fs_find_entry(dir, &fname, &page);
776 F2FS_I(dir)->task = NULL;
777 }
778 if (de) {
779 f2fs_put_page(page, 0);
780 err = -EEXIST;
781 } else if (IS_ERR(page)) {
782 err = PTR_ERR(page);
783 } else {
784 err = f2fs_add_dentry(dir, &fname, inode, ino, mode);
785 }
786 f2fs_free_filename(&fname);
787 return err;
788 }
789
f2fs_do_tmpfile(struct inode * inode,struct inode * dir,struct f2fs_filename * fname)790 int f2fs_do_tmpfile(struct inode *inode, struct inode *dir,
791 struct f2fs_filename *fname)
792 {
793 struct page *page;
794 int err = 0;
795
796 f2fs_down_write(&F2FS_I(inode)->i_sem);
797 page = f2fs_init_inode_metadata(inode, dir, fname, NULL);
798 if (IS_ERR(page)) {
799 err = PTR_ERR(page);
800 goto fail;
801 }
802 f2fs_put_page(page, 1);
803
804 clear_inode_flag(inode, FI_NEW_INODE);
805 f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
806 fail:
807 f2fs_up_write(&F2FS_I(inode)->i_sem);
808 return err;
809 }
810
f2fs_drop_nlink(struct inode * dir,struct inode * inode)811 void f2fs_drop_nlink(struct inode *dir, struct inode *inode)
812 {
813 struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
814
815 f2fs_down_write(&F2FS_I(inode)->i_sem);
816
817 if (S_ISDIR(inode->i_mode))
818 f2fs_i_links_write(dir, false);
819 inode_set_ctime_current(inode);
820
821 f2fs_i_links_write(inode, false);
822 if (S_ISDIR(inode->i_mode)) {
823 f2fs_i_links_write(inode, false);
824 f2fs_i_size_write(inode, 0);
825 }
826 f2fs_up_write(&F2FS_I(inode)->i_sem);
827
828 if (inode->i_nlink == 0)
829 f2fs_add_orphan_inode(inode);
830 else
831 f2fs_release_orphan_inode(sbi);
832 }
833
834 /*
835 * It only removes the dentry from the dentry page, corresponding name
836 * entry in name page does not need to be touched during deletion.
837 */
f2fs_delete_entry(struct f2fs_dir_entry * dentry,struct page * page,struct inode * dir,struct inode * inode)838 void f2fs_delete_entry(struct f2fs_dir_entry *dentry, struct page *page,
839 struct inode *dir, struct inode *inode)
840 {
841 struct f2fs_dentry_block *dentry_blk;
842 unsigned int bit_pos;
843 int slots = GET_DENTRY_SLOTS(le16_to_cpu(dentry->name_len));
844 int i;
845
846 f2fs_update_time(F2FS_I_SB(dir), REQ_TIME);
847
848 if (F2FS_OPTION(F2FS_I_SB(dir)).fsync_mode == FSYNC_MODE_STRICT)
849 f2fs_add_ino_entry(F2FS_I_SB(dir), dir->i_ino, TRANS_DIR_INO);
850
851 if (f2fs_has_inline_dentry(dir))
852 return f2fs_delete_inline_entry(dentry, page, dir, inode);
853
854 lock_page(page);
855 f2fs_wait_on_page_writeback(page, DATA, true, true);
856
857 dentry_blk = page_address(page);
858 bit_pos = dentry - dentry_blk->dentry;
859 for (i = 0; i < slots; i++)
860 __clear_bit_le(bit_pos + i, &dentry_blk->dentry_bitmap);
861
862 /* Let's check and deallocate this dentry page */
863 bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
864 NR_DENTRY_IN_BLOCK,
865 0);
866 set_page_dirty(page);
867
868 if (bit_pos == NR_DENTRY_IN_BLOCK &&
869 !f2fs_truncate_hole(dir, page->index, page->index + 1)) {
870 f2fs_clear_page_cache_dirty_tag(page);
871 clear_page_dirty_for_io(page);
872 ClearPageUptodate(page);
873 clear_page_private_all(page);
874
875 inode_dec_dirty_pages(dir);
876 f2fs_remove_dirty_inode(dir);
877 }
878 f2fs_put_page(page, 1);
879
880 inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
881 f2fs_mark_inode_dirty_sync(dir, false);
882
883 if (inode)
884 f2fs_drop_nlink(dir, inode);
885 }
886
f2fs_empty_dir(struct inode * dir)887 bool f2fs_empty_dir(struct inode *dir)
888 {
889 unsigned long bidx = 0;
890 struct page *dentry_page;
891 unsigned int bit_pos;
892 struct f2fs_dentry_block *dentry_blk;
893 unsigned long nblock = dir_blocks(dir);
894
895 if (f2fs_has_inline_dentry(dir))
896 return f2fs_empty_inline_dir(dir);
897
898 while (bidx < nblock) {
899 pgoff_t next_pgofs;
900
901 dentry_page = f2fs_find_data_page(dir, bidx, &next_pgofs);
902 if (IS_ERR(dentry_page)) {
903 if (PTR_ERR(dentry_page) == -ENOENT) {
904 bidx = next_pgofs;
905 continue;
906 } else {
907 return false;
908 }
909 }
910
911 dentry_blk = page_address(dentry_page);
912 if (bidx == 0)
913 bit_pos = 2;
914 else
915 bit_pos = 0;
916 bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
917 NR_DENTRY_IN_BLOCK,
918 bit_pos);
919
920 f2fs_put_page(dentry_page, 0);
921
922 if (bit_pos < NR_DENTRY_IN_BLOCK)
923 return false;
924
925 bidx++;
926 }
927 return true;
928 }
929
f2fs_fill_dentries(struct dir_context * ctx,struct f2fs_dentry_ptr * d,unsigned int start_pos,struct fscrypt_str * fstr)930 int f2fs_fill_dentries(struct dir_context *ctx, struct f2fs_dentry_ptr *d,
931 unsigned int start_pos, struct fscrypt_str *fstr)
932 {
933 unsigned char d_type = DT_UNKNOWN;
934 unsigned int bit_pos;
935 struct f2fs_dir_entry *de = NULL;
936 struct fscrypt_str de_name = FSTR_INIT(NULL, 0);
937 struct f2fs_sb_info *sbi = F2FS_I_SB(d->inode);
938 struct blk_plug plug;
939 bool readdir_ra = sbi->readdir_ra;
940 bool found_valid_dirent = false;
941 int err = 0;
942
943 bit_pos = ((unsigned long)ctx->pos % d->max);
944
945 if (readdir_ra)
946 blk_start_plug(&plug);
947
948 while (bit_pos < d->max) {
949 bit_pos = find_next_bit_le(d->bitmap, d->max, bit_pos);
950 if (bit_pos >= d->max)
951 break;
952
953 de = &d->dentry[bit_pos];
954 if (de->name_len == 0) {
955 if (found_valid_dirent || !bit_pos) {
956 f2fs_warn_ratelimited(sbi,
957 "invalid namelen(0), ino:%u, run fsck to fix.",
958 le32_to_cpu(de->ino));
959 set_sbi_flag(sbi, SBI_NEED_FSCK);
960 }
961 bit_pos++;
962 ctx->pos = start_pos + bit_pos;
963 continue;
964 }
965
966 d_type = fs_ftype_to_dtype(de->file_type);
967
968 de_name.name = d->filename[bit_pos];
969 de_name.len = le16_to_cpu(de->name_len);
970
971 /* check memory boundary before moving forward */
972 bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
973 if (unlikely(bit_pos > d->max ||
974 le16_to_cpu(de->name_len) > F2FS_NAME_LEN)) {
975 f2fs_warn(sbi, "%s: corrupted namelen=%d, run fsck to fix.",
976 __func__, le16_to_cpu(de->name_len));
977 set_sbi_flag(sbi, SBI_NEED_FSCK);
978 err = -EFSCORRUPTED;
979 f2fs_handle_error(sbi, ERROR_CORRUPTED_DIRENT);
980 goto out;
981 }
982
983 if (IS_ENCRYPTED(d->inode)) {
984 int save_len = fstr->len;
985
986 err = fscrypt_fname_disk_to_usr(d->inode,
987 (u32)le32_to_cpu(de->hash_code),
988 0, &de_name, fstr);
989 if (err)
990 goto out;
991
992 de_name = *fstr;
993 fstr->len = save_len;
994 }
995
996 if (!dir_emit(ctx, de_name.name, de_name.len,
997 le32_to_cpu(de->ino), d_type)) {
998 err = 1;
999 goto out;
1000 }
1001
1002 if (readdir_ra)
1003 f2fs_ra_node_page(sbi, le32_to_cpu(de->ino));
1004
1005 ctx->pos = start_pos + bit_pos;
1006 found_valid_dirent = true;
1007 }
1008 out:
1009 if (readdir_ra)
1010 blk_finish_plug(&plug);
1011 return err;
1012 }
1013
f2fs_readdir(struct file * file,struct dir_context * ctx)1014 static int f2fs_readdir(struct file *file, struct dir_context *ctx)
1015 {
1016 struct inode *inode = file_inode(file);
1017 unsigned long npages = dir_blocks(inode);
1018 struct f2fs_dentry_block *dentry_blk = NULL;
1019 struct page *dentry_page = NULL;
1020 struct file_ra_state *ra = &file->f_ra;
1021 loff_t start_pos = ctx->pos;
1022 unsigned int n = ((unsigned long)ctx->pos / NR_DENTRY_IN_BLOCK);
1023 struct f2fs_dentry_ptr d;
1024 struct fscrypt_str fstr = FSTR_INIT(NULL, 0);
1025 int err = 0;
1026
1027 if (IS_ENCRYPTED(inode)) {
1028 err = fscrypt_prepare_readdir(inode);
1029 if (err)
1030 goto out;
1031
1032 err = fscrypt_fname_alloc_buffer(F2FS_NAME_LEN, &fstr);
1033 if (err < 0)
1034 goto out;
1035 }
1036
1037 if (f2fs_has_inline_dentry(inode)) {
1038 err = f2fs_read_inline_dir(file, ctx, &fstr);
1039 goto out_free;
1040 }
1041
1042 for (; n < npages; ctx->pos = n * NR_DENTRY_IN_BLOCK) {
1043 pgoff_t next_pgofs;
1044
1045 /* allow readdir() to be interrupted */
1046 if (fatal_signal_pending(current)) {
1047 err = -ERESTARTSYS;
1048 goto out_free;
1049 }
1050 cond_resched();
1051
1052 /* readahead for multi pages of dir */
1053 if (npages - n > 1 && !ra_has_index(ra, n))
1054 page_cache_sync_readahead(inode->i_mapping, ra, file, n,
1055 min(npages - n, (pgoff_t)MAX_DIR_RA_PAGES));
1056
1057 dentry_page = f2fs_find_data_page(inode, n, &next_pgofs);
1058 if (IS_ERR(dentry_page)) {
1059 err = PTR_ERR(dentry_page);
1060 if (err == -ENOENT) {
1061 err = 0;
1062 n = next_pgofs;
1063 continue;
1064 } else {
1065 goto out_free;
1066 }
1067 }
1068
1069 dentry_blk = page_address(dentry_page);
1070
1071 make_dentry_ptr_block(inode, &d, dentry_blk);
1072
1073 err = f2fs_fill_dentries(ctx, &d,
1074 n * NR_DENTRY_IN_BLOCK, &fstr);
1075 if (err) {
1076 f2fs_put_page(dentry_page, 0);
1077 break;
1078 }
1079
1080 f2fs_put_page(dentry_page, 0);
1081
1082 n++;
1083 }
1084 out_free:
1085 fscrypt_fname_free_buffer(&fstr);
1086 out:
1087 trace_f2fs_readdir(inode, start_pos, ctx->pos, err);
1088 return err < 0 ? err : 0;
1089 }
1090
1091 const struct file_operations f2fs_dir_operations = {
1092 .llseek = generic_file_llseek,
1093 .read = generic_read_dir,
1094 .iterate_shared = f2fs_readdir,
1095 .fsync = f2fs_sync_file,
1096 .unlocked_ioctl = f2fs_ioctl,
1097 #ifdef CONFIG_COMPAT
1098 .compat_ioctl = f2fs_compat_ioctl,
1099 #endif
1100 };
1101