qib_fs: fix (some) dcache abuses
[linux-2.6.git] / fs / f2fs / dir.c
blob594fc1bb64ef44f1ea734ec7222b710a670b37fe
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)
26 if (level < MAX_DIR_HASH_DEPTH / 2)
27 return 1 << level;
28 else
29 return 1 << ((MAX_DIR_HASH_DEPTH / 2) - 1);
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, unsigned int idx)
70 unsigned long i;
71 unsigned long bidx = 0;
73 for (i = 0; i < level; i++)
74 bidx += dir_buckets(i) * bucket_blocks(i);
75 bidx += idx * bucket_blocks(level);
76 return bidx;
79 static bool early_match_name(const char *name, size_t namelen,
80 f2fs_hash_t namehash, struct f2fs_dir_entry *de)
82 if (le16_to_cpu(de->name_len) != namelen)
83 return false;
85 if (de->hash_code != namehash)
86 return false;
88 return true;
91 static struct f2fs_dir_entry *find_in_block(struct page *dentry_page,
92 const char *name, size_t namelen, int *max_slots,
93 f2fs_hash_t namehash, struct page **res_page)
95 struct f2fs_dir_entry *de;
96 unsigned long bit_pos, end_pos, next_pos;
97 struct f2fs_dentry_block *dentry_blk = kmap(dentry_page);
98 int slots;
100 bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
101 NR_DENTRY_IN_BLOCK, 0);
102 while (bit_pos < NR_DENTRY_IN_BLOCK) {
103 de = &dentry_blk->dentry[bit_pos];
104 slots = GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
106 if (early_match_name(name, namelen, namehash, de)) {
107 if (!memcmp(dentry_blk->filename[bit_pos],
108 name, namelen)) {
109 *res_page = dentry_page;
110 goto found;
113 next_pos = bit_pos + slots;
114 bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
115 NR_DENTRY_IN_BLOCK, next_pos);
116 if (bit_pos >= NR_DENTRY_IN_BLOCK)
117 end_pos = NR_DENTRY_IN_BLOCK;
118 else
119 end_pos = bit_pos;
120 if (*max_slots < end_pos - next_pos)
121 *max_slots = end_pos - next_pos;
124 de = NULL;
125 kunmap(dentry_page);
126 found:
127 return de;
130 static struct f2fs_dir_entry *find_in_level(struct inode *dir,
131 unsigned int level, const char *name, size_t namelen,
132 f2fs_hash_t namehash, struct page **res_page)
134 int s = GET_DENTRY_SLOTS(namelen);
135 unsigned int nbucket, nblock;
136 unsigned int bidx, end_block;
137 struct page *dentry_page;
138 struct f2fs_dir_entry *de = NULL;
139 bool room = false;
140 int max_slots = 0;
142 f2fs_bug_on(level > MAX_DIR_HASH_DEPTH);
144 nbucket = dir_buckets(level);
145 nblock = bucket_blocks(level);
147 bidx = dir_block_index(level, le32_to_cpu(namehash) % nbucket);
148 end_block = bidx + nblock;
150 for (; bidx < end_block; bidx++) {
151 /* no need to allocate new dentry pages to all the indices */
152 dentry_page = find_data_page(dir, bidx, true);
153 if (IS_ERR(dentry_page)) {
154 room = true;
155 continue;
158 de = find_in_block(dentry_page, name, namelen,
159 &max_slots, namehash, res_page);
160 if (de)
161 break;
163 if (max_slots >= s)
164 room = true;
165 f2fs_put_page(dentry_page, 0);
168 if (!de && room && F2FS_I(dir)->chash != namehash) {
169 F2FS_I(dir)->chash = namehash;
170 F2FS_I(dir)->clevel = level;
173 return de;
177 * Find an entry in the specified directory with the wanted name.
178 * It returns the page where the entry was found (as a parameter - res_page),
179 * and the entry itself. Page is returned mapped and unlocked.
180 * Entry is guaranteed to be valid.
182 struct f2fs_dir_entry *f2fs_find_entry(struct inode *dir,
183 struct qstr *child, struct page **res_page)
185 const char *name = child->name;
186 size_t namelen = child->len;
187 unsigned long npages = dir_blocks(dir);
188 struct f2fs_dir_entry *de = NULL;
189 f2fs_hash_t name_hash;
190 unsigned int max_depth;
191 unsigned int level;
193 if (namelen > F2FS_NAME_LEN)
194 return NULL;
196 if (npages == 0)
197 return NULL;
199 *res_page = NULL;
201 name_hash = f2fs_dentry_hash(name, namelen);
202 max_depth = F2FS_I(dir)->i_current_depth;
204 for (level = 0; level < max_depth; level++) {
205 de = find_in_level(dir, level, name,
206 namelen, name_hash, res_page);
207 if (de)
208 break;
210 if (!de && F2FS_I(dir)->chash != name_hash) {
211 F2FS_I(dir)->chash = name_hash;
212 F2FS_I(dir)->clevel = level - 1;
214 return de;
217 struct f2fs_dir_entry *f2fs_parent_dir(struct inode *dir, struct page **p)
219 struct page *page;
220 struct f2fs_dir_entry *de;
221 struct f2fs_dentry_block *dentry_blk;
223 page = get_lock_data_page(dir, 0);
224 if (IS_ERR(page))
225 return NULL;
227 dentry_blk = kmap(page);
228 de = &dentry_blk->dentry[1];
229 *p = page;
230 unlock_page(page);
231 return de;
234 ino_t f2fs_inode_by_name(struct inode *dir, struct qstr *qstr)
236 ino_t res = 0;
237 struct f2fs_dir_entry *de;
238 struct page *page;
240 de = f2fs_find_entry(dir, qstr, &page);
241 if (de) {
242 res = le32_to_cpu(de->ino);
243 kunmap(page);
244 f2fs_put_page(page, 0);
247 return res;
250 void f2fs_set_link(struct inode *dir, struct f2fs_dir_entry *de,
251 struct page *page, struct inode *inode)
253 lock_page(page);
254 wait_on_page_writeback(page);
255 de->ino = cpu_to_le32(inode->i_ino);
256 set_de_type(de, inode);
257 kunmap(page);
258 set_page_dirty(page);
259 dir->i_mtime = dir->i_ctime = CURRENT_TIME;
260 mark_inode_dirty(dir);
262 /* update parent inode number before releasing dentry page */
263 F2FS_I(inode)->i_pino = dir->i_ino;
265 f2fs_put_page(page, 1);
268 static void init_dent_inode(const struct qstr *name, struct page *ipage)
270 struct f2fs_node *rn;
272 /* copy name info. to this inode page */
273 rn = F2FS_NODE(ipage);
274 rn->i.i_namelen = cpu_to_le32(name->len);
275 memcpy(rn->i.i_name, name->name, name->len);
276 set_page_dirty(ipage);
279 int update_dent_inode(struct inode *inode, const struct qstr *name)
281 struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
282 struct page *page;
284 page = get_node_page(sbi, inode->i_ino);
285 if (IS_ERR(page))
286 return PTR_ERR(page);
288 init_dent_inode(name, page);
289 f2fs_put_page(page, 1);
291 return 0;
294 static int make_empty_dir(struct inode *inode,
295 struct inode *parent, struct page *page)
297 struct page *dentry_page;
298 struct f2fs_dentry_block *dentry_blk;
299 struct f2fs_dir_entry *de;
300 void *kaddr;
302 dentry_page = get_new_data_page(inode, page, 0, true);
303 if (IS_ERR(dentry_page))
304 return PTR_ERR(dentry_page);
306 kaddr = kmap_atomic(dentry_page);
307 dentry_blk = (struct f2fs_dentry_block *)kaddr;
309 de = &dentry_blk->dentry[0];
310 de->name_len = cpu_to_le16(1);
311 de->hash_code = 0;
312 de->ino = cpu_to_le32(inode->i_ino);
313 memcpy(dentry_blk->filename[0], ".", 1);
314 set_de_type(de, inode);
316 de = &dentry_blk->dentry[1];
317 de->hash_code = 0;
318 de->name_len = cpu_to_le16(2);
319 de->ino = cpu_to_le32(parent->i_ino);
320 memcpy(dentry_blk->filename[1], "..", 2);
321 set_de_type(de, inode);
323 test_and_set_bit_le(0, &dentry_blk->dentry_bitmap);
324 test_and_set_bit_le(1, &dentry_blk->dentry_bitmap);
325 kunmap_atomic(kaddr);
327 set_page_dirty(dentry_page);
328 f2fs_put_page(dentry_page, 1);
329 return 0;
332 static struct page *init_inode_metadata(struct inode *inode,
333 struct inode *dir, const struct qstr *name)
335 struct page *page;
336 int err;
338 if (is_inode_flag_set(F2FS_I(inode), FI_NEW_INODE)) {
339 page = new_inode_page(inode, name);
340 if (IS_ERR(page))
341 return page;
343 if (S_ISDIR(inode->i_mode)) {
344 err = make_empty_dir(inode, dir, page);
345 if (err)
346 goto error;
349 err = f2fs_init_acl(inode, dir, page);
350 if (err)
351 goto error;
353 err = f2fs_init_security(inode, dir, name, page);
354 if (err)
355 goto error;
357 wait_on_page_writeback(page);
358 } else {
359 page = get_node_page(F2FS_SB(dir->i_sb), inode->i_ino);
360 if (IS_ERR(page))
361 return page;
363 wait_on_page_writeback(page);
364 set_cold_node(inode, page);
367 init_dent_inode(name, page);
370 * This file should be checkpointed during fsync.
371 * We lost i_pino from now on.
373 if (is_inode_flag_set(F2FS_I(inode), FI_INC_LINK)) {
374 file_lost_pino(inode);
375 inc_nlink(inode);
377 return page;
379 error:
380 f2fs_put_page(page, 1);
381 remove_inode_page(inode);
382 return ERR_PTR(err);
385 static void update_parent_metadata(struct inode *dir, struct inode *inode,
386 unsigned int current_depth)
388 if (is_inode_flag_set(F2FS_I(inode), FI_NEW_INODE)) {
389 if (S_ISDIR(inode->i_mode)) {
390 inc_nlink(dir);
391 set_inode_flag(F2FS_I(dir), FI_UPDATE_DIR);
393 clear_inode_flag(F2FS_I(inode), FI_NEW_INODE);
395 dir->i_mtime = dir->i_ctime = CURRENT_TIME;
396 if (F2FS_I(dir)->i_current_depth != current_depth) {
397 F2FS_I(dir)->i_current_depth = current_depth;
398 set_inode_flag(F2FS_I(dir), FI_UPDATE_DIR);
401 if (is_inode_flag_set(F2FS_I(dir), FI_UPDATE_DIR))
402 update_inode_page(dir);
403 else
404 mark_inode_dirty(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 mutex by calling mutex_lock_op() and
436 * mutex_unlock_op().
438 int __f2fs_add_link(struct inode *dir, const struct qstr *name, struct inode *inode)
440 unsigned int bit_pos;
441 unsigned int level;
442 unsigned int current_depth;
443 unsigned long bidx, block;
444 f2fs_hash_t dentry_hash;
445 struct f2fs_dir_entry *de;
446 unsigned int nbucket, nblock;
447 size_t namelen = name->len;
448 struct page *dentry_page = NULL;
449 struct f2fs_dentry_block *dentry_blk = NULL;
450 int slots = GET_DENTRY_SLOTS(namelen);
451 struct page *page;
452 int err = 0;
453 int i;
455 dentry_hash = f2fs_dentry_hash(name->name, name->len);
456 level = 0;
457 current_depth = F2FS_I(dir)->i_current_depth;
458 if (F2FS_I(dir)->chash == dentry_hash) {
459 level = F2FS_I(dir)->clevel;
460 F2FS_I(dir)->chash = 0;
463 start:
464 if (current_depth == MAX_DIR_HASH_DEPTH)
465 return -ENOSPC;
467 /* Increase the depth, if required */
468 if (level == current_depth)
469 ++current_depth;
471 nbucket = dir_buckets(level);
472 nblock = bucket_blocks(level);
474 bidx = dir_block_index(level, (le32_to_cpu(dentry_hash) % nbucket));
476 for (block = bidx; block <= (bidx + nblock - 1); block++) {
477 dentry_page = get_new_data_page(dir, NULL, block, true);
478 if (IS_ERR(dentry_page))
479 return PTR_ERR(dentry_page);
481 dentry_blk = kmap(dentry_page);
482 bit_pos = room_for_filename(dentry_blk, slots);
483 if (bit_pos < NR_DENTRY_IN_BLOCK)
484 goto add_dentry;
486 kunmap(dentry_page);
487 f2fs_put_page(dentry_page, 1);
490 /* Move to next level to find the empty slot for new dentry */
491 ++level;
492 goto start;
493 add_dentry:
494 wait_on_page_writeback(dentry_page);
496 page = init_inode_metadata(inode, dir, name);
497 if (IS_ERR(page)) {
498 err = PTR_ERR(page);
499 goto fail;
501 de = &dentry_blk->dentry[bit_pos];
502 de->hash_code = dentry_hash;
503 de->name_len = cpu_to_le16(namelen);
504 memcpy(dentry_blk->filename[bit_pos], name->name, name->len);
505 de->ino = cpu_to_le32(inode->i_ino);
506 set_de_type(de, inode);
507 for (i = 0; i < slots; i++)
508 test_and_set_bit_le(bit_pos + i, &dentry_blk->dentry_bitmap);
509 set_page_dirty(dentry_page);
511 /* we don't need to mark_inode_dirty now */
512 F2FS_I(inode)->i_pino = dir->i_ino;
513 update_inode(inode, page);
514 f2fs_put_page(page, 1);
516 update_parent_metadata(dir, inode, current_depth);
517 fail:
518 clear_inode_flag(F2FS_I(dir), FI_UPDATE_DIR);
519 kunmap(dentry_page);
520 f2fs_put_page(dentry_page, 1);
521 return err;
525 * It only removes the dentry from the dentry page,corresponding name
526 * entry in name page does not need to be touched during deletion.
528 void f2fs_delete_entry(struct f2fs_dir_entry *dentry, struct page *page,
529 struct inode *inode)
531 struct f2fs_dentry_block *dentry_blk;
532 unsigned int bit_pos;
533 struct address_space *mapping = page->mapping;
534 struct inode *dir = mapping->host;
535 struct f2fs_sb_info *sbi = F2FS_SB(dir->i_sb);
536 int slots = GET_DENTRY_SLOTS(le16_to_cpu(dentry->name_len));
537 void *kaddr = page_address(page);
538 int i;
540 lock_page(page);
541 wait_on_page_writeback(page);
543 dentry_blk = (struct f2fs_dentry_block *)kaddr;
544 bit_pos = dentry - (struct f2fs_dir_entry *)dentry_blk->dentry;
545 for (i = 0; i < slots; i++)
546 test_and_clear_bit_le(bit_pos + i, &dentry_blk->dentry_bitmap);
548 /* Let's check and deallocate this dentry page */
549 bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
550 NR_DENTRY_IN_BLOCK,
552 kunmap(page); /* kunmap - pair of f2fs_find_entry */
553 set_page_dirty(page);
555 dir->i_ctime = dir->i_mtime = CURRENT_TIME;
557 if (inode && S_ISDIR(inode->i_mode)) {
558 drop_nlink(dir);
559 update_inode_page(dir);
560 } else {
561 mark_inode_dirty(dir);
564 if (inode) {
565 inode->i_ctime = CURRENT_TIME;
566 drop_nlink(inode);
567 if (S_ISDIR(inode->i_mode)) {
568 drop_nlink(inode);
569 i_size_write(inode, 0);
571 update_inode_page(inode);
573 if (inode->i_nlink == 0)
574 add_orphan_inode(sbi, inode->i_ino);
575 else
576 release_orphan_inode(sbi);
579 if (bit_pos == NR_DENTRY_IN_BLOCK) {
580 truncate_hole(dir, page->index, page->index + 1);
581 clear_page_dirty_for_io(page);
582 ClearPageUptodate(page);
583 dec_page_count(sbi, F2FS_DIRTY_DENTS);
584 inode_dec_dirty_dents(dir);
586 f2fs_put_page(page, 1);
589 bool f2fs_empty_dir(struct inode *dir)
591 unsigned long bidx;
592 struct page *dentry_page;
593 unsigned int bit_pos;
594 struct f2fs_dentry_block *dentry_blk;
595 unsigned long nblock = dir_blocks(dir);
597 for (bidx = 0; bidx < nblock; bidx++) {
598 void *kaddr;
599 dentry_page = get_lock_data_page(dir, bidx);
600 if (IS_ERR(dentry_page)) {
601 if (PTR_ERR(dentry_page) == -ENOENT)
602 continue;
603 else
604 return false;
607 kaddr = kmap_atomic(dentry_page);
608 dentry_blk = (struct f2fs_dentry_block *)kaddr;
609 if (bidx == 0)
610 bit_pos = 2;
611 else
612 bit_pos = 0;
613 bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
614 NR_DENTRY_IN_BLOCK,
615 bit_pos);
616 kunmap_atomic(kaddr);
618 f2fs_put_page(dentry_page, 1);
620 if (bit_pos < NR_DENTRY_IN_BLOCK)
621 return false;
623 return true;
626 static int f2fs_readdir(struct file *file, struct dir_context *ctx)
628 struct inode *inode = file_inode(file);
629 unsigned long npages = dir_blocks(inode);
630 unsigned int bit_pos = 0;
631 struct f2fs_dentry_block *dentry_blk = NULL;
632 struct f2fs_dir_entry *de = NULL;
633 struct page *dentry_page = NULL;
634 unsigned int n = ((unsigned long)ctx->pos / NR_DENTRY_IN_BLOCK);
635 unsigned char d_type = DT_UNKNOWN;
637 bit_pos = ((unsigned long)ctx->pos % NR_DENTRY_IN_BLOCK);
639 for ( ; n < npages; n++) {
640 dentry_page = get_lock_data_page(inode, n);
641 if (IS_ERR(dentry_page))
642 continue;
644 dentry_blk = kmap(dentry_page);
645 while (bit_pos < NR_DENTRY_IN_BLOCK) {
646 bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
647 NR_DENTRY_IN_BLOCK,
648 bit_pos);
649 if (bit_pos >= NR_DENTRY_IN_BLOCK)
650 break;
652 de = &dentry_blk->dentry[bit_pos];
653 if (de->file_type < F2FS_FT_MAX)
654 d_type = f2fs_filetype_table[de->file_type];
655 else
656 d_type = DT_UNKNOWN;
657 if (!dir_emit(ctx,
658 dentry_blk->filename[bit_pos],
659 le16_to_cpu(de->name_len),
660 le32_to_cpu(de->ino), d_type))
661 goto stop;
663 bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
664 ctx->pos = n * NR_DENTRY_IN_BLOCK + bit_pos;
666 bit_pos = 0;
667 ctx->pos = (n + 1) * NR_DENTRY_IN_BLOCK;
668 kunmap(dentry_page);
669 f2fs_put_page(dentry_page, 1);
670 dentry_page = NULL;
672 stop:
673 if (dentry_page && !IS_ERR(dentry_page)) {
674 kunmap(dentry_page);
675 f2fs_put_page(dentry_page, 1);
678 return 0;
681 const struct file_operations f2fs_dir_operations = {
682 .llseek = generic_file_llseek,
683 .read = generic_read_dir,
684 .iterate = f2fs_readdir,
685 .fsync = f2fs_sync_file,
686 .unlocked_ioctl = f2fs_ioctl,