Linux 3.16-rc2
[linux/fpc-iii.git] / fs / f2fs / dir.c
blob966acb039e3b9927465558a99a1df9bdd38f3844
1 /*
2 * fs/f2fs/dir.c
4 * Copyright (c) 2012 Samsung Electronics Co., Ltd.
5 * http://www.samsung.com/
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.
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"
18 static unsigned long dir_blocks(struct inode *inode)
20 return ((unsigned long long) (i_size_read(inode) + PAGE_CACHE_SIZE - 1))
21 >> PAGE_CACHE_SHIFT;
24 static unsigned int dir_buckets(unsigned int level, int dir_level)
26 if (level + dir_level < MAX_DIR_HASH_DEPTH / 2)
27 return 1 << (level + dir_level);
28 else
29 return MAX_DIR_BUCKETS;
32 static unsigned int bucket_blocks(unsigned int level)
34 if (level < MAX_DIR_HASH_DEPTH / 2)
35 return 2;
36 else
37 return 4;
40 static 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,
51 #define S_SHIFT 12
52 static unsigned char f2fs_type_by_mode[S_IFMT >> S_SHIFT] = {
53 [S_IFREG >> S_SHIFT] = F2FS_FT_REG_FILE,
54 [S_IFDIR >> S_SHIFT] = F2FS_FT_DIR,
55 [S_IFCHR >> S_SHIFT] = F2FS_FT_CHRDEV,
56 [S_IFBLK >> S_SHIFT] = F2FS_FT_BLKDEV,
57 [S_IFIFO >> S_SHIFT] = F2FS_FT_FIFO,
58 [S_IFSOCK >> S_SHIFT] = F2FS_FT_SOCK,
59 [S_IFLNK >> S_SHIFT] = F2FS_FT_SYMLINK,
62 static void set_de_type(struct f2fs_dir_entry *de, struct inode *inode)
64 umode_t mode = inode->i_mode;
65 de->file_type = f2fs_type_by_mode[(mode & S_IFMT) >> S_SHIFT];
68 static unsigned long dir_block_index(unsigned int level,
69 int dir_level, unsigned int idx)
71 unsigned long i;
72 unsigned long bidx = 0;
74 for (i = 0; i < level; i++)
75 bidx += dir_buckets(i, dir_level) * bucket_blocks(i);
76 bidx += idx * bucket_blocks(level);
77 return bidx;
80 static bool early_match_name(const char *name, size_t namelen,
81 f2fs_hash_t namehash, struct f2fs_dir_entry *de)
83 if (le16_to_cpu(de->name_len) != namelen)
84 return false;
86 if (de->hash_code != namehash)
87 return false;
89 return true;
92 static struct f2fs_dir_entry *find_in_block(struct page *dentry_page,
93 const char *name, size_t namelen, int *max_slots,
94 f2fs_hash_t namehash, struct page **res_page)
96 struct f2fs_dir_entry *de;
97 unsigned long bit_pos = 0;
98 struct f2fs_dentry_block *dentry_blk = kmap(dentry_page);
99 const void *dentry_bits = &dentry_blk->dentry_bitmap;
100 int max_len = 0;
102 while (bit_pos < NR_DENTRY_IN_BLOCK) {
103 if (!test_bit_le(bit_pos, dentry_bits)) {
104 if (bit_pos == 0)
105 max_len = 1;
106 else if (!test_bit_le(bit_pos - 1, dentry_bits))
107 max_len++;
108 bit_pos++;
109 continue;
111 de = &dentry_blk->dentry[bit_pos];
112 if (early_match_name(name, namelen, namehash, de)) {
113 if (!memcmp(dentry_blk->filename[bit_pos],
114 name, namelen)) {
115 *res_page = dentry_page;
116 goto found;
119 if (max_len > *max_slots) {
120 *max_slots = max_len;
121 max_len = 0;
123 bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
126 de = NULL;
127 kunmap(dentry_page);
128 found:
129 if (max_len > *max_slots)
130 *max_slots = max_len;
131 return de;
134 static struct f2fs_dir_entry *find_in_level(struct inode *dir,
135 unsigned int level, const char *name, size_t namelen,
136 f2fs_hash_t namehash, struct page **res_page)
138 int s = GET_DENTRY_SLOTS(namelen);
139 unsigned int nbucket, nblock;
140 unsigned int bidx, end_block;
141 struct page *dentry_page;
142 struct f2fs_dir_entry *de = NULL;
143 bool room = false;
144 int max_slots = 0;
146 f2fs_bug_on(level > MAX_DIR_HASH_DEPTH);
148 nbucket = dir_buckets(level, F2FS_I(dir)->i_dir_level);
149 nblock = bucket_blocks(level);
151 bidx = dir_block_index(level, F2FS_I(dir)->i_dir_level,
152 le32_to_cpu(namehash) % nbucket);
153 end_block = bidx + nblock;
155 for (; bidx < end_block; bidx++) {
156 /* no need to allocate new dentry pages to all the indices */
157 dentry_page = find_data_page(dir, bidx, true);
158 if (IS_ERR(dentry_page)) {
159 room = true;
160 continue;
163 de = find_in_block(dentry_page, name, namelen,
164 &max_slots, namehash, res_page);
165 if (de)
166 break;
168 if (max_slots >= s)
169 room = true;
170 f2fs_put_page(dentry_page, 0);
173 if (!de && room && F2FS_I(dir)->chash != namehash) {
174 F2FS_I(dir)->chash = namehash;
175 F2FS_I(dir)->clevel = level;
178 return de;
182 * Find an entry in the specified directory with the wanted name.
183 * It returns the page where the entry was found (as a parameter - res_page),
184 * and the entry itself. Page is returned mapped and unlocked.
185 * Entry is guaranteed to be valid.
187 struct f2fs_dir_entry *f2fs_find_entry(struct inode *dir,
188 struct qstr *child, struct page **res_page)
190 const char *name = child->name;
191 size_t namelen = child->len;
192 unsigned long npages = dir_blocks(dir);
193 struct f2fs_dir_entry *de = NULL;
194 f2fs_hash_t name_hash;
195 unsigned int max_depth;
196 unsigned int level;
198 if (npages == 0)
199 return NULL;
201 *res_page = NULL;
203 name_hash = f2fs_dentry_hash(name, namelen);
204 max_depth = F2FS_I(dir)->i_current_depth;
206 for (level = 0; level < max_depth; level++) {
207 de = find_in_level(dir, level, name,
208 namelen, name_hash, res_page);
209 if (de)
210 break;
212 if (!de && F2FS_I(dir)->chash != name_hash) {
213 F2FS_I(dir)->chash = name_hash;
214 F2FS_I(dir)->clevel = level - 1;
216 return de;
219 struct f2fs_dir_entry *f2fs_parent_dir(struct inode *dir, struct page **p)
221 struct page *page;
222 struct f2fs_dir_entry *de;
223 struct f2fs_dentry_block *dentry_blk;
225 page = get_lock_data_page(dir, 0);
226 if (IS_ERR(page))
227 return NULL;
229 dentry_blk = kmap(page);
230 de = &dentry_blk->dentry[1];
231 *p = page;
232 unlock_page(page);
233 return de;
236 ino_t f2fs_inode_by_name(struct inode *dir, struct qstr *qstr)
238 ino_t res = 0;
239 struct f2fs_dir_entry *de;
240 struct page *page;
242 de = f2fs_find_entry(dir, qstr, &page);
243 if (de) {
244 res = le32_to_cpu(de->ino);
245 kunmap(page);
246 f2fs_put_page(page, 0);
249 return res;
252 void f2fs_set_link(struct inode *dir, struct f2fs_dir_entry *de,
253 struct page *page, struct inode *inode)
255 lock_page(page);
256 f2fs_wait_on_page_writeback(page, DATA);
257 de->ino = cpu_to_le32(inode->i_ino);
258 set_de_type(de, inode);
259 kunmap(page);
260 set_page_dirty(page);
261 dir->i_mtime = dir->i_ctime = CURRENT_TIME;
262 mark_inode_dirty(dir);
264 f2fs_put_page(page, 1);
267 static void init_dent_inode(const struct qstr *name, struct page *ipage)
269 struct f2fs_inode *ri;
271 f2fs_wait_on_page_writeback(ipage, NODE);
273 /* copy name info. to this inode page */
274 ri = F2FS_INODE(ipage);
275 ri->i_namelen = cpu_to_le32(name->len);
276 memcpy(ri->i_name, name->name, name->len);
277 set_page_dirty(ipage);
280 int update_dent_inode(struct inode *inode, const struct qstr *name)
282 struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
283 struct page *page;
285 page = get_node_page(sbi, inode->i_ino);
286 if (IS_ERR(page))
287 return PTR_ERR(page);
289 init_dent_inode(name, page);
290 f2fs_put_page(page, 1);
292 return 0;
295 static int make_empty_dir(struct inode *inode,
296 struct inode *parent, struct page *page)
298 struct page *dentry_page;
299 struct f2fs_dentry_block *dentry_blk;
300 struct f2fs_dir_entry *de;
301 void *kaddr;
303 dentry_page = get_new_data_page(inode, page, 0, true);
304 if (IS_ERR(dentry_page))
305 return PTR_ERR(dentry_page);
307 kaddr = kmap_atomic(dentry_page);
308 dentry_blk = (struct f2fs_dentry_block *)kaddr;
310 de = &dentry_blk->dentry[0];
311 de->name_len = cpu_to_le16(1);
312 de->hash_code = 0;
313 de->ino = cpu_to_le32(inode->i_ino);
314 memcpy(dentry_blk->filename[0], ".", 1);
315 set_de_type(de, inode);
317 de = &dentry_blk->dentry[1];
318 de->hash_code = 0;
319 de->name_len = cpu_to_le16(2);
320 de->ino = cpu_to_le32(parent->i_ino);
321 memcpy(dentry_blk->filename[1], "..", 2);
322 set_de_type(de, inode);
324 test_and_set_bit_le(0, &dentry_blk->dentry_bitmap);
325 test_and_set_bit_le(1, &dentry_blk->dentry_bitmap);
326 kunmap_atomic(kaddr);
328 set_page_dirty(dentry_page);
329 f2fs_put_page(dentry_page, 1);
330 return 0;
333 static struct page *init_inode_metadata(struct inode *inode,
334 struct inode *dir, const struct qstr *name)
336 struct page *page;
337 int err;
339 if (is_inode_flag_set(F2FS_I(inode), FI_NEW_INODE)) {
340 page = new_inode_page(inode, name);
341 if (IS_ERR(page))
342 return page;
344 if (S_ISDIR(inode->i_mode)) {
345 err = make_empty_dir(inode, dir, page);
346 if (err)
347 goto error;
350 err = f2fs_init_acl(inode, dir, page);
351 if (err)
352 goto put_error;
354 err = f2fs_init_security(inode, dir, name, page);
355 if (err)
356 goto put_error;
357 } else {
358 page = get_node_page(F2FS_SB(dir->i_sb), inode->i_ino);
359 if (IS_ERR(page))
360 return page;
362 set_cold_node(inode, page);
365 init_dent_inode(name, page);
368 * This file should be checkpointed during fsync.
369 * We lost i_pino from now on.
371 if (is_inode_flag_set(F2FS_I(inode), FI_INC_LINK)) {
372 file_lost_pino(inode);
373 inc_nlink(inode);
375 return page;
377 put_error:
378 f2fs_put_page(page, 1);
379 /* once the failed inode becomes a bad inode, i_mode is S_IFREG */
380 truncate_inode_pages(&inode->i_data, 0);
381 truncate_blocks(inode, 0);
382 remove_dirty_dir_inode(inode);
383 error:
384 remove_inode_page(inode);
385 return ERR_PTR(err);
388 static void update_parent_metadata(struct inode *dir, struct inode *inode,
389 unsigned int current_depth)
391 if (is_inode_flag_set(F2FS_I(inode), FI_NEW_INODE)) {
392 if (S_ISDIR(inode->i_mode)) {
393 inc_nlink(dir);
394 set_inode_flag(F2FS_I(dir), FI_UPDATE_DIR);
396 clear_inode_flag(F2FS_I(inode), FI_NEW_INODE);
398 dir->i_mtime = dir->i_ctime = CURRENT_TIME;
399 mark_inode_dirty(dir);
401 if (F2FS_I(dir)->i_current_depth != current_depth) {
402 F2FS_I(dir)->i_current_depth = current_depth;
403 set_inode_flag(F2FS_I(dir), FI_UPDATE_DIR);
406 if (is_inode_flag_set(F2FS_I(inode), FI_INC_LINK))
407 clear_inode_flag(F2FS_I(inode), FI_INC_LINK);
410 static int room_for_filename(struct f2fs_dentry_block *dentry_blk, int slots)
412 int bit_start = 0;
413 int zero_start, zero_end;
414 next:
415 zero_start = find_next_zero_bit_le(&dentry_blk->dentry_bitmap,
416 NR_DENTRY_IN_BLOCK,
417 bit_start);
418 if (zero_start >= NR_DENTRY_IN_BLOCK)
419 return NR_DENTRY_IN_BLOCK;
421 zero_end = find_next_bit_le(&dentry_blk->dentry_bitmap,
422 NR_DENTRY_IN_BLOCK,
423 zero_start);
424 if (zero_end - zero_start >= slots)
425 return zero_start;
427 bit_start = zero_end + 1;
429 if (zero_end + 1 >= NR_DENTRY_IN_BLOCK)
430 return NR_DENTRY_IN_BLOCK;
431 goto next;
435 * Caller should grab and release a rwsem by calling f2fs_lock_op() and
436 * f2fs_unlock_op().
438 int __f2fs_add_link(struct inode *dir, const struct qstr *name,
439 struct inode *inode)
441 unsigned int bit_pos;
442 unsigned int level;
443 unsigned int current_depth;
444 unsigned long bidx, block;
445 f2fs_hash_t dentry_hash;
446 struct f2fs_dir_entry *de;
447 unsigned int nbucket, nblock;
448 size_t namelen = name->len;
449 struct page *dentry_page = NULL;
450 struct f2fs_dentry_block *dentry_blk = NULL;
451 int slots = GET_DENTRY_SLOTS(namelen);
452 struct page *page;
453 int err = 0;
454 int i;
456 dentry_hash = f2fs_dentry_hash(name->name, name->len);
457 level = 0;
458 current_depth = F2FS_I(dir)->i_current_depth;
459 if (F2FS_I(dir)->chash == dentry_hash) {
460 level = F2FS_I(dir)->clevel;
461 F2FS_I(dir)->chash = 0;
464 start:
465 if (unlikely(current_depth == MAX_DIR_HASH_DEPTH))
466 return -ENOSPC;
468 /* Increase the depth, if required */
469 if (level == current_depth)
470 ++current_depth;
472 nbucket = dir_buckets(level, F2FS_I(dir)->i_dir_level);
473 nblock = bucket_blocks(level);
475 bidx = dir_block_index(level, F2FS_I(dir)->i_dir_level,
476 (le32_to_cpu(dentry_hash) % nbucket));
478 for (block = bidx; block <= (bidx + nblock - 1); block++) {
479 dentry_page = get_new_data_page(dir, NULL, block, true);
480 if (IS_ERR(dentry_page))
481 return PTR_ERR(dentry_page);
483 dentry_blk = kmap(dentry_page);
484 bit_pos = room_for_filename(dentry_blk, slots);
485 if (bit_pos < NR_DENTRY_IN_BLOCK)
486 goto add_dentry;
488 kunmap(dentry_page);
489 f2fs_put_page(dentry_page, 1);
492 /* Move to next level to find the empty slot for new dentry */
493 ++level;
494 goto start;
495 add_dentry:
496 f2fs_wait_on_page_writeback(dentry_page, DATA);
498 down_write(&F2FS_I(inode)->i_sem);
499 page = init_inode_metadata(inode, dir, name);
500 if (IS_ERR(page)) {
501 err = PTR_ERR(page);
502 goto fail;
504 de = &dentry_blk->dentry[bit_pos];
505 de->hash_code = dentry_hash;
506 de->name_len = cpu_to_le16(namelen);
507 memcpy(dentry_blk->filename[bit_pos], name->name, name->len);
508 de->ino = cpu_to_le32(inode->i_ino);
509 set_de_type(de, inode);
510 for (i = 0; i < slots; i++)
511 test_and_set_bit_le(bit_pos + i, &dentry_blk->dentry_bitmap);
512 set_page_dirty(dentry_page);
514 /* we don't need to mark_inode_dirty now */
515 F2FS_I(inode)->i_pino = dir->i_ino;
516 update_inode(inode, page);
517 f2fs_put_page(page, 1);
519 update_parent_metadata(dir, inode, current_depth);
520 fail:
521 up_write(&F2FS_I(inode)->i_sem);
523 if (is_inode_flag_set(F2FS_I(dir), FI_UPDATE_DIR)) {
524 update_inode_page(dir);
525 clear_inode_flag(F2FS_I(dir), FI_UPDATE_DIR);
527 kunmap(dentry_page);
528 f2fs_put_page(dentry_page, 1);
529 return err;
533 * It only removes the dentry from the dentry page,corresponding name
534 * entry in name page does not need to be touched during deletion.
536 void f2fs_delete_entry(struct f2fs_dir_entry *dentry, struct page *page,
537 struct inode *inode)
539 struct f2fs_dentry_block *dentry_blk;
540 unsigned int bit_pos;
541 struct address_space *mapping = page->mapping;
542 struct inode *dir = mapping->host;
543 int slots = GET_DENTRY_SLOTS(le16_to_cpu(dentry->name_len));
544 void *kaddr = page_address(page);
545 int i;
547 lock_page(page);
548 f2fs_wait_on_page_writeback(page, DATA);
550 dentry_blk = (struct f2fs_dentry_block *)kaddr;
551 bit_pos = dentry - (struct f2fs_dir_entry *)dentry_blk->dentry;
552 for (i = 0; i < slots; i++)
553 test_and_clear_bit_le(bit_pos + i, &dentry_blk->dentry_bitmap);
555 /* Let's check and deallocate this dentry page */
556 bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
557 NR_DENTRY_IN_BLOCK,
559 kunmap(page); /* kunmap - pair of f2fs_find_entry */
560 set_page_dirty(page);
562 dir->i_ctime = dir->i_mtime = CURRENT_TIME;
564 if (inode) {
565 struct f2fs_sb_info *sbi = F2FS_SB(dir->i_sb);
567 down_write(&F2FS_I(inode)->i_sem);
569 if (S_ISDIR(inode->i_mode)) {
570 drop_nlink(dir);
571 update_inode_page(dir);
573 inode->i_ctime = CURRENT_TIME;
574 drop_nlink(inode);
575 if (S_ISDIR(inode->i_mode)) {
576 drop_nlink(inode);
577 i_size_write(inode, 0);
579 up_write(&F2FS_I(inode)->i_sem);
580 update_inode_page(inode);
582 if (inode->i_nlink == 0)
583 add_orphan_inode(sbi, inode->i_ino);
584 else
585 release_orphan_inode(sbi);
588 if (bit_pos == NR_DENTRY_IN_BLOCK) {
589 truncate_hole(dir, page->index, page->index + 1);
590 clear_page_dirty_for_io(page);
591 ClearPageUptodate(page);
592 inode_dec_dirty_dents(dir);
594 f2fs_put_page(page, 1);
597 bool f2fs_empty_dir(struct inode *dir)
599 unsigned long bidx;
600 struct page *dentry_page;
601 unsigned int bit_pos;
602 struct f2fs_dentry_block *dentry_blk;
603 unsigned long nblock = dir_blocks(dir);
605 for (bidx = 0; bidx < nblock; bidx++) {
606 void *kaddr;
607 dentry_page = get_lock_data_page(dir, bidx);
608 if (IS_ERR(dentry_page)) {
609 if (PTR_ERR(dentry_page) == -ENOENT)
610 continue;
611 else
612 return false;
615 kaddr = kmap_atomic(dentry_page);
616 dentry_blk = (struct f2fs_dentry_block *)kaddr;
617 if (bidx == 0)
618 bit_pos = 2;
619 else
620 bit_pos = 0;
621 bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
622 NR_DENTRY_IN_BLOCK,
623 bit_pos);
624 kunmap_atomic(kaddr);
626 f2fs_put_page(dentry_page, 1);
628 if (bit_pos < NR_DENTRY_IN_BLOCK)
629 return false;
631 return true;
634 static int f2fs_readdir(struct file *file, struct dir_context *ctx)
636 struct inode *inode = file_inode(file);
637 unsigned long npages = dir_blocks(inode);
638 unsigned int bit_pos = 0;
639 struct f2fs_dentry_block *dentry_blk = NULL;
640 struct f2fs_dir_entry *de = NULL;
641 struct page *dentry_page = NULL;
642 struct file_ra_state *ra = &file->f_ra;
643 unsigned int n = ((unsigned long)ctx->pos / NR_DENTRY_IN_BLOCK);
644 unsigned char d_type = DT_UNKNOWN;
646 bit_pos = ((unsigned long)ctx->pos % NR_DENTRY_IN_BLOCK);
648 /* readahead for multi pages of dir */
649 if (npages - n > 1 && !ra_has_index(ra, n))
650 page_cache_sync_readahead(inode->i_mapping, ra, file, n,
651 min(npages - n, (pgoff_t)MAX_DIR_RA_PAGES));
653 for (; n < npages; n++) {
654 dentry_page = get_lock_data_page(inode, n);
655 if (IS_ERR(dentry_page))
656 continue;
658 dentry_blk = kmap(dentry_page);
659 while (bit_pos < NR_DENTRY_IN_BLOCK) {
660 bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
661 NR_DENTRY_IN_BLOCK,
662 bit_pos);
663 if (bit_pos >= NR_DENTRY_IN_BLOCK)
664 break;
666 de = &dentry_blk->dentry[bit_pos];
667 if (de->file_type < F2FS_FT_MAX)
668 d_type = f2fs_filetype_table[de->file_type];
669 else
670 d_type = DT_UNKNOWN;
671 if (!dir_emit(ctx,
672 dentry_blk->filename[bit_pos],
673 le16_to_cpu(de->name_len),
674 le32_to_cpu(de->ino), d_type))
675 goto stop;
677 bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
678 ctx->pos = n * NR_DENTRY_IN_BLOCK + bit_pos;
680 bit_pos = 0;
681 ctx->pos = (n + 1) * NR_DENTRY_IN_BLOCK;
682 kunmap(dentry_page);
683 f2fs_put_page(dentry_page, 1);
684 dentry_page = NULL;
686 stop:
687 if (dentry_page && !IS_ERR(dentry_page)) {
688 kunmap(dentry_page);
689 f2fs_put_page(dentry_page, 1);
692 return 0;
695 const struct file_operations f2fs_dir_operations = {
696 .llseek = generic_file_llseek,
697 .read = generic_read_dir,
698 .iterate = f2fs_readdir,
699 .fsync = f2fs_sync_file,
700 .unlocked_ioctl = f2fs_ioctl,