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perf/x86: Add a few more comments
[linux-2.6/btrfs-unstable.git] / fs / f2fs / data.c
blob2261ccdd0b5f04a37be390f1b28c8703fafa86b4
1 /*
2 * fs/f2fs/data.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 <linux/buffer_head.h>
14 #include <linux/mpage.h>
15 #include <linux/aio.h>
16 #include <linux/writeback.h>
17 #include <linux/backing-dev.h>
18 #include <linux/blkdev.h>
19 #include <linux/bio.h>
20 #include <linux/prefetch.h>
21
22 #include "f2fs.h"
23 #include "node.h"
24 #include "segment.h"
25 #include <trace/events/f2fs.h>
26
27 static void f2fs_read_end_io(struct bio *bio, int err)
28 {
29 struct bio_vec *bvec;
30 int i;
31
32 bio_for_each_segment_all(bvec, bio, i) {
33 struct page *page = bvec->bv_page;
34
35 if (!err) {
36 SetPageUptodate(page);
37 } else {
38 ClearPageUptodate(page);
39 SetPageError(page);
40 }
41 unlock_page(page);
42 }
43 bio_put(bio);
44 }
45
46 static void f2fs_write_end_io(struct bio *bio, int err)
47 {
48 struct f2fs_sb_info *sbi = F2FS_SB(bio->bi_io_vec->bv_page->mapping->host->i_sb);
49 struct bio_vec *bvec;
50 int i;
51
52 bio_for_each_segment_all(bvec, bio, i) {
53 struct page *page = bvec->bv_page;
54
55 if (unlikely(err)) {
56 SetPageError(page);
57 set_bit(AS_EIO, &page->mapping->flags);
58 set_ckpt_flags(sbi->ckpt, CP_ERROR_FLAG);
59 sbi->sb->s_flags |= MS_RDONLY;
60 }
61 end_page_writeback(page);
62 dec_page_count(sbi, F2FS_WRITEBACK);
63 }
64
65 if (bio->bi_private)
66 complete(bio->bi_private);
67
68 if (!get_pages(sbi, F2FS_WRITEBACK) &&
69 !list_empty(&sbi->cp_wait.task_list))
70 wake_up(&sbi->cp_wait);
71
72 bio_put(bio);
73 }
74
75 /*
76 * Low-level block read/write IO operations.
77 */
78 static struct bio *__bio_alloc(struct f2fs_sb_info *sbi, block_t blk_addr,
79 int npages, bool is_read)
80 {
81 struct bio *bio;
82
83 /* No failure on bio allocation */
84 bio = bio_alloc(GFP_NOIO, npages);
85
86 bio->bi_bdev = sbi->sb->s_bdev;
87 bio->bi_iter.bi_sector = SECTOR_FROM_BLOCK(sbi, blk_addr);
88 bio->bi_end_io = is_read ? f2fs_read_end_io : f2fs_write_end_io;
89
90 return bio;
91 }
92
93 static void __submit_merged_bio(struct f2fs_bio_info *io)
94 {
95 struct f2fs_io_info *fio = &io->fio;
96 int rw;
97
98 if (!io->bio)
99 return;
100
101 rw = fio->rw;
102
103 if (is_read_io(rw)) {
104 trace_f2fs_submit_read_bio(io->sbi->sb, rw,
105 fio->type, io->bio);
106 submit_bio(rw, io->bio);
107 } else {
108 trace_f2fs_submit_write_bio(io->sbi->sb, rw,
109 fio->type, io->bio);
110 /*
111 * META_FLUSH is only from the checkpoint procedure, and we
112 * should wait this metadata bio for FS consistency.
113 */
114 if (fio->type == META_FLUSH) {
115 DECLARE_COMPLETION_ONSTACK(wait);
116 io->bio->bi_private = &wait;
117 submit_bio(rw, io->bio);
118 wait_for_completion(&wait);
119 } else {
120 submit_bio(rw, io->bio);
121 }
122 }
123
124 io->bio = NULL;
125 }
126
127 void f2fs_submit_merged_bio(struct f2fs_sb_info *sbi,
128 enum page_type type, int rw)
129 {
130 enum page_type btype = PAGE_TYPE_OF_BIO(type);
131 struct f2fs_bio_info *io;
132
133 io = is_read_io(rw) ? &sbi->read_io : &sbi->write_io[btype];
134
135 mutex_lock(&io->io_mutex);
136
137 /* change META to META_FLUSH in the checkpoint procedure */
138 if (type >= META_FLUSH) {
139 io->fio.type = META_FLUSH;
140 io->fio.rw = WRITE_FLUSH_FUA | REQ_META | REQ_PRIO;
141 }
142 __submit_merged_bio(io);
143 mutex_unlock(&io->io_mutex);
144 }
145
146 /*
147 * Fill the locked page with data located in the block address.
148 * Return unlocked page.
149 */
150 int f2fs_submit_page_bio(struct f2fs_sb_info *sbi, struct page *page,
151 block_t blk_addr, int rw)
152 {
153 struct bio *bio;
154
155 trace_f2fs_submit_page_bio(page, blk_addr, rw);
156
157 /* Allocate a new bio */
158 bio = __bio_alloc(sbi, blk_addr, 1, is_read_io(rw));
159
160 if (bio_add_page(bio, page, PAGE_CACHE_SIZE, 0) < PAGE_CACHE_SIZE) {
161 bio_put(bio);
162 f2fs_put_page(page, 1);
163 return -EFAULT;
164 }
165
166 submit_bio(rw, bio);
167 return 0;
168 }
169
170 void f2fs_submit_page_mbio(struct f2fs_sb_info *sbi, struct page *page,
171 block_t blk_addr, struct f2fs_io_info *fio)
172 {
173 enum page_type btype = PAGE_TYPE_OF_BIO(fio->type);
174 struct f2fs_bio_info *io;
175 bool is_read = is_read_io(fio->rw);
176
177 io = is_read ? &sbi->read_io : &sbi->write_io[btype];
178
179 verify_block_addr(sbi, blk_addr);
180
181 mutex_lock(&io->io_mutex);
182
183 if (!is_read)
184 inc_page_count(sbi, F2FS_WRITEBACK);
185
186 if (io->bio && (io->last_block_in_bio != blk_addr - 1 ||
187 io->fio.rw != fio->rw))
188 __submit_merged_bio(io);
189 alloc_new:
190 if (io->bio == NULL) {
191 int bio_blocks = MAX_BIO_BLOCKS(max_hw_blocks(sbi));
192
193 io->bio = __bio_alloc(sbi, blk_addr, bio_blocks, is_read);
194 io->fio = *fio;
195 }
196
197 if (bio_add_page(io->bio, page, PAGE_CACHE_SIZE, 0) <
198 PAGE_CACHE_SIZE) {
199 __submit_merged_bio(io);
200 goto alloc_new;
201 }
202
203 io->last_block_in_bio = blk_addr;
204
205 mutex_unlock(&io->io_mutex);
206 trace_f2fs_submit_page_mbio(page, fio->rw, fio->type, blk_addr);
207 }
208
209 /*
210 * Lock ordering for the change of data block address:
211 * ->data_page
212 * ->node_page
213 * update block addresses in the node page
214 */
215 static void __set_data_blkaddr(struct dnode_of_data *dn, block_t new_addr)
216 {
217 struct f2fs_node *rn;
218 __le32 *addr_array;
219 struct page *node_page = dn->node_page;
220 unsigned int ofs_in_node = dn->ofs_in_node;
221
222 f2fs_wait_on_page_writeback(node_page, NODE);
223
224 rn = F2FS_NODE(node_page);
225
226 /* Get physical address of data block */
227 addr_array = blkaddr_in_node(rn);
228 addr_array[ofs_in_node] = cpu_to_le32(new_addr);
229 set_page_dirty(node_page);
230 }
231
232 int reserve_new_block(struct dnode_of_data *dn)
233 {
234 struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb);
235
236 if (unlikely(is_inode_flag_set(F2FS_I(dn->inode), FI_NO_ALLOC)))
237 return -EPERM;
238 if (unlikely(!inc_valid_block_count(sbi, dn->inode, 1)))
239 return -ENOSPC;
240
241 trace_f2fs_reserve_new_block(dn->inode, dn->nid, dn->ofs_in_node);
242
243 __set_data_blkaddr(dn, NEW_ADDR);
244 dn->data_blkaddr = NEW_ADDR;
245 mark_inode_dirty(dn->inode);
246 sync_inode_page(dn);
247 return 0;
248 }
249
250 int f2fs_reserve_block(struct dnode_of_data *dn, pgoff_t index)
251 {
252 bool need_put = dn->inode_page ? false : true;
253 int err;
254
255 /* if inode_page exists, index should be zero */
256 f2fs_bug_on(!need_put && index);
257
258 err = get_dnode_of_data(dn, index, ALLOC_NODE);
259 if (err)
260 return err;
261
262 if (dn->data_blkaddr == NULL_ADDR)
263 err = reserve_new_block(dn);
264 if (err || need_put)
265 f2fs_put_dnode(dn);
266 return err;
267 }
268
269 static int check_extent_cache(struct inode *inode, pgoff_t pgofs,
270 struct buffer_head *bh_result)
271 {
272 struct f2fs_inode_info *fi = F2FS_I(inode);
273 pgoff_t start_fofs, end_fofs;
274 block_t start_blkaddr;
275
276 if (is_inode_flag_set(fi, FI_NO_EXTENT))
277 return 0;
278
279 read_lock(&fi->ext.ext_lock);
280 if (fi->ext.len == 0) {
281 read_unlock(&fi->ext.ext_lock);
282 return 0;
283 }
284
285 stat_inc_total_hit(inode->i_sb);
286
287 start_fofs = fi->ext.fofs;
288 end_fofs = fi->ext.fofs + fi->ext.len - 1;
289 start_blkaddr = fi->ext.blk_addr;
290
291 if (pgofs >= start_fofs && pgofs <= end_fofs) {
292 unsigned int blkbits = inode->i_sb->s_blocksize_bits;
293 size_t count;
294
295 clear_buffer_new(bh_result);
296 map_bh(bh_result, inode->i_sb,
297 start_blkaddr + pgofs - start_fofs);
298 count = end_fofs - pgofs + 1;
299 if (count < (UINT_MAX >> blkbits))
300 bh_result->b_size = (count << blkbits);
301 else
302 bh_result->b_size = UINT_MAX;
303
304 stat_inc_read_hit(inode->i_sb);
305 read_unlock(&fi->ext.ext_lock);
306 return 1;
307 }
308 read_unlock(&fi->ext.ext_lock);
309 return 0;
310 }
311
312 void update_extent_cache(block_t blk_addr, struct dnode_of_data *dn)
313 {
314 struct f2fs_inode_info *fi = F2FS_I(dn->inode);
315 pgoff_t fofs, start_fofs, end_fofs;
316 block_t start_blkaddr, end_blkaddr;
317 int need_update = true;
318
319 f2fs_bug_on(blk_addr == NEW_ADDR);
320 fofs = start_bidx_of_node(ofs_of_node(dn->node_page), fi) +
321 dn->ofs_in_node;
322
323 /* Update the page address in the parent node */
324 __set_data_blkaddr(dn, blk_addr);
325
326 if (is_inode_flag_set(fi, FI_NO_EXTENT))
327 return;
328
329 write_lock(&fi->ext.ext_lock);
330
331 start_fofs = fi->ext.fofs;
332 end_fofs = fi->ext.fofs + fi->ext.len - 1;
333 start_blkaddr = fi->ext.blk_addr;
334 end_blkaddr = fi->ext.blk_addr + fi->ext.len - 1;
335
336 /* Drop and initialize the matched extent */
337 if (fi->ext.len == 1 && fofs == start_fofs)
338 fi->ext.len = 0;
339
340 /* Initial extent */
341 if (fi->ext.len == 0) {
342 if (blk_addr != NULL_ADDR) {
343 fi->ext.fofs = fofs;
344 fi->ext.blk_addr = blk_addr;
345 fi->ext.len = 1;
346 }
347 goto end_update;
348 }
349
350 /* Front merge */
351 if (fofs == start_fofs - 1 && blk_addr == start_blkaddr - 1) {
352 fi->ext.fofs--;
353 fi->ext.blk_addr--;
354 fi->ext.len++;
355 goto end_update;
356 }
357
358 /* Back merge */
359 if (fofs == end_fofs + 1 && blk_addr == end_blkaddr + 1) {
360 fi->ext.len++;
361 goto end_update;
362 }
363
364 /* Split the existing extent */
365 if (fi->ext.len > 1 &&
366 fofs >= start_fofs && fofs <= end_fofs) {
367 if ((end_fofs - fofs) < (fi->ext.len >> 1)) {
368 fi->ext.len = fofs - start_fofs;
369 } else {
370 fi->ext.fofs = fofs + 1;
371 fi->ext.blk_addr = start_blkaddr +
372 fofs - start_fofs + 1;
373 fi->ext.len -= fofs - start_fofs + 1;
374 }
375 } else {
376 need_update = false;
377 }
378
379 /* Finally, if the extent is very fragmented, let's drop the cache. */
380 if (fi->ext.len < F2FS_MIN_EXTENT_LEN) {
381 fi->ext.len = 0;
382 set_inode_flag(fi, FI_NO_EXTENT);
383 need_update = true;
384 }
385 end_update:
386 write_unlock(&fi->ext.ext_lock);
387 if (need_update)
388 sync_inode_page(dn);
389 return;
390 }
391
392 struct page *find_data_page(struct inode *inode, pgoff_t index, bool sync)
393 {
394 struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
395 struct address_space *mapping = inode->i_mapping;
396 struct dnode_of_data dn;
397 struct page *page;
398 int err;
399
400 page = find_get_page(mapping, index);
401 if (page && PageUptodate(page))
402 return page;
403 f2fs_put_page(page, 0);
404
405 set_new_dnode(&dn, inode, NULL, NULL, 0);
406 err = get_dnode_of_data(&dn, index, LOOKUP_NODE);
407 if (err)
408 return ERR_PTR(err);
409 f2fs_put_dnode(&dn);
410
411 if (dn.data_blkaddr == NULL_ADDR)
412 return ERR_PTR(-ENOENT);
413
414 /* By fallocate(), there is no cached page, but with NEW_ADDR */
415 if (unlikely(dn.data_blkaddr == NEW_ADDR))
416 return ERR_PTR(-EINVAL);
417
418 page = grab_cache_page_write_begin(mapping, index, AOP_FLAG_NOFS);
419 if (!page)
420 return ERR_PTR(-ENOMEM);
421
422 if (PageUptodate(page)) {
423 unlock_page(page);
424 return page;
425 }
426
427 err = f2fs_submit_page_bio(sbi, page, dn.data_blkaddr,
428 sync ? READ_SYNC : READA);
429 if (err)
430 return ERR_PTR(err);
431
432 if (sync) {
433 wait_on_page_locked(page);
434 if (unlikely(!PageUptodate(page))) {
435 f2fs_put_page(page, 0);
436 return ERR_PTR(-EIO);
437 }
438 }
439 return page;
440 }
441
442 /*
443 * If it tries to access a hole, return an error.
444 * Because, the callers, functions in dir.c and GC, should be able to know
445 * whether this page exists or not.
446 */
447 struct page *get_lock_data_page(struct inode *inode, pgoff_t index)
448 {
449 struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
450 struct address_space *mapping = inode->i_mapping;
451 struct dnode_of_data dn;
452 struct page *page;
453 int err;
454
455 repeat:
456 page = grab_cache_page_write_begin(mapping, index, AOP_FLAG_NOFS);
457 if (!page)
458 return ERR_PTR(-ENOMEM);
459
460 set_new_dnode(&dn, inode, NULL, NULL, 0);
461 err = get_dnode_of_data(&dn, index, LOOKUP_NODE);
462 if (err) {
463 f2fs_put_page(page, 1);
464 return ERR_PTR(err);
465 }
466 f2fs_put_dnode(&dn);
467
468 if (unlikely(dn.data_blkaddr == NULL_ADDR)) {
469 f2fs_put_page(page, 1);
470 return ERR_PTR(-ENOENT);
471 }
472
473 if (PageUptodate(page))
474 return page;
475
476 /*
477 * A new dentry page is allocated but not able to be written, since its
478 * new inode page couldn't be allocated due to -ENOSPC.
479 * In such the case, its blkaddr can be remained as NEW_ADDR.
480 * see, f2fs_add_link -> get_new_data_page -> init_inode_metadata.
481 */
482 if (dn.data_blkaddr == NEW_ADDR) {
483 zero_user_segment(page, 0, PAGE_CACHE_SIZE);
484 SetPageUptodate(page);
485 return page;
486 }
487
488 err = f2fs_submit_page_bio(sbi, page, dn.data_blkaddr, READ_SYNC);
489 if (err)
490 return ERR_PTR(err);
491
492 lock_page(page);
493 if (unlikely(!PageUptodate(page))) {
494 f2fs_put_page(page, 1);
495 return ERR_PTR(-EIO);
496 }
497 if (unlikely(page->mapping != mapping)) {
498 f2fs_put_page(page, 1);
499 goto repeat;
500 }
501 return page;
502 }
503
504 /*
505 * Caller ensures that this data page is never allocated.
506 * A new zero-filled data page is allocated in the page cache.
507 *
508 * Also, caller should grab and release a rwsem by calling f2fs_lock_op() and
509 * f2fs_unlock_op().
510 * Note that, ipage is set only by make_empty_dir.
511 */
512 struct page *get_new_data_page(struct inode *inode,
513 struct page *ipage, pgoff_t index, bool new_i_size)
514 {
515 struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
516 struct address_space *mapping = inode->i_mapping;
517 struct page *page;
518 struct dnode_of_data dn;
519 int err;
520
521 set_new_dnode(&dn, inode, ipage, NULL, 0);
522 err = f2fs_reserve_block(&dn, index);
523 if (err)
524 return ERR_PTR(err);
525 repeat:
526 page = grab_cache_page(mapping, index);
527 if (!page) {
528 err = -ENOMEM;
529 goto put_err;
530 }
531
532 if (PageUptodate(page))
533 return page;
534
535 if (dn.data_blkaddr == NEW_ADDR) {
536 zero_user_segment(page, 0, PAGE_CACHE_SIZE);
537 SetPageUptodate(page);
538 } else {
539 err = f2fs_submit_page_bio(sbi, page, dn.data_blkaddr,
540 READ_SYNC);
541 if (err)
542 goto put_err;
543
544 lock_page(page);
545 if (unlikely(!PageUptodate(page))) {
546 f2fs_put_page(page, 1);
547 err = -EIO;
548 goto put_err;
549 }
550 if (unlikely(page->mapping != mapping)) {
551 f2fs_put_page(page, 1);
552 goto repeat;
553 }
554 }
555
556 if (new_i_size &&
557 i_size_read(inode) < ((index + 1) << PAGE_CACHE_SHIFT)) {
558 i_size_write(inode, ((index + 1) << PAGE_CACHE_SHIFT));
559 /* Only the directory inode sets new_i_size */
560 set_inode_flag(F2FS_I(inode), FI_UPDATE_DIR);
561 }
562 return page;
563
564 put_err:
565 f2fs_put_dnode(&dn);
566 return ERR_PTR(err);
567 }
568
569 static int __allocate_data_block(struct dnode_of_data *dn)
570 {
571 struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb);
572 struct f2fs_summary sum;
573 block_t new_blkaddr;
574 struct node_info ni;
575 int type;
576
577 if (unlikely(is_inode_flag_set(F2FS_I(dn->inode), FI_NO_ALLOC)))
578 return -EPERM;
579 if (unlikely(!inc_valid_block_count(sbi, dn->inode, 1)))
580 return -ENOSPC;
581
582 __set_data_blkaddr(dn, NEW_ADDR);
583 dn->data_blkaddr = NEW_ADDR;
584
585 get_node_info(sbi, dn->nid, &ni);
586 set_summary(&sum, dn->nid, dn->ofs_in_node, ni.version);
587
588 type = CURSEG_WARM_DATA;
589
590 allocate_data_block(sbi, NULL, NULL_ADDR, &new_blkaddr, &sum, type);
591
592 /* direct IO doesn't use extent cache to maximize the performance */
593 set_inode_flag(F2FS_I(dn->inode), FI_NO_EXTENT);
594 update_extent_cache(new_blkaddr, dn);
595 clear_inode_flag(F2FS_I(dn->inode), FI_NO_EXTENT);
596
597 dn->data_blkaddr = new_blkaddr;
598 return 0;
599 }
600
601 /*
602 * get_data_block() now supported readahead/bmap/rw direct_IO with mapped bh.
603 * If original data blocks are allocated, then give them to blockdev.
604 * Otherwise,
605 * a. preallocate requested block addresses
606 * b. do not use extent cache for better performance
607 * c. give the block addresses to blockdev
608 */
609 static int get_data_block(struct inode *inode, sector_t iblock,
610 struct buffer_head *bh_result, int create)
611 {
612 struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
613 unsigned int blkbits = inode->i_sb->s_blocksize_bits;
614 unsigned maxblocks = bh_result->b_size >> blkbits;
615 struct dnode_of_data dn;
616 int mode = create ? ALLOC_NODE : LOOKUP_NODE_RA;
617 pgoff_t pgofs, end_offset;
618 int err = 0, ofs = 1;
619 bool allocated = false;
620
621 /* Get the page offset from the block offset(iblock) */
622 pgofs = (pgoff_t)(iblock >> (PAGE_CACHE_SHIFT - blkbits));
623
624 if (check_extent_cache(inode, pgofs, bh_result))
625 goto out;
626
627 if (create)
628 f2fs_lock_op(sbi);
629
630 /* When reading holes, we need its node page */
631 set_new_dnode(&dn, inode, NULL, NULL, 0);
632 err = get_dnode_of_data(&dn, pgofs, mode);
633 if (err) {
634 if (err == -ENOENT)
635 err = 0;
636 goto unlock_out;
637 }
638 if (dn.data_blkaddr == NEW_ADDR)
639 goto put_out;
640
641 if (dn.data_blkaddr != NULL_ADDR) {
642 map_bh(bh_result, inode->i_sb, dn.data_blkaddr);
643 } else if (create) {
644 err = __allocate_data_block(&dn);
645 if (err)
646 goto put_out;
647 allocated = true;
648 map_bh(bh_result, inode->i_sb, dn.data_blkaddr);
649 } else {
650 goto put_out;
651 }
652
653 end_offset = IS_INODE(dn.node_page) ?
654 ADDRS_PER_INODE(F2FS_I(inode)) : ADDRS_PER_BLOCK;
655 bh_result->b_size = (((size_t)1) << blkbits);
656 dn.ofs_in_node++;
657 pgofs++;
658
659 get_next:
660 if (dn.ofs_in_node >= end_offset) {
661 if (allocated)
662 sync_inode_page(&dn);
663 allocated = false;
664 f2fs_put_dnode(&dn);
665
666 set_new_dnode(&dn, inode, NULL, NULL, 0);
667 err = get_dnode_of_data(&dn, pgofs, mode);
668 if (err) {
669 if (err == -ENOENT)
670 err = 0;
671 goto unlock_out;
672 }
673 if (dn.data_blkaddr == NEW_ADDR)
674 goto put_out;
675
676 end_offset = IS_INODE(dn.node_page) ?
677 ADDRS_PER_INODE(F2FS_I(inode)) : ADDRS_PER_BLOCK;
678 }
679
680 if (maxblocks > (bh_result->b_size >> blkbits)) {
681 block_t blkaddr = datablock_addr(dn.node_page, dn.ofs_in_node);
682 if (blkaddr == NULL_ADDR && create) {
683 err = __allocate_data_block(&dn);
684 if (err)
685 goto sync_out;
686 allocated = true;
687 blkaddr = dn.data_blkaddr;
688 }
689 /* Give more consecutive addresses for the read ahead */
690 if (blkaddr == (bh_result->b_blocknr + ofs)) {
691 ofs++;
692 dn.ofs_in_node++;
693 pgofs++;
694 bh_result->b_size += (((size_t)1) << blkbits);
695 goto get_next;
696 }
697 }
698 sync_out:
699 if (allocated)
700 sync_inode_page(&dn);
701 put_out:
702 f2fs_put_dnode(&dn);
703 unlock_out:
704 if (create)
705 f2fs_unlock_op(sbi);
706 out:
707 trace_f2fs_get_data_block(inode, iblock, bh_result, err);
708 return err;
709 }
710
711 static int f2fs_read_data_page(struct file *file, struct page *page)
712 {
713 struct inode *inode = page->mapping->host;
714 int ret;
715
716 /* If the file has inline data, try to read it directlly */
717 if (f2fs_has_inline_data(inode))
718 ret = f2fs_read_inline_data(inode, page);
719 else
720 ret = mpage_readpage(page, get_data_block);
721
722 return ret;
723 }
724
725 static int f2fs_read_data_pages(struct file *file,
726 struct address_space *mapping,
727 struct list_head *pages, unsigned nr_pages)
728 {
729 struct inode *inode = file->f_mapping->host;
730
731 /* If the file has inline data, skip readpages */
732 if (f2fs_has_inline_data(inode))
733 return 0;
734
735 return mpage_readpages(mapping, pages, nr_pages, get_data_block);
736 }
737
738 int do_write_data_page(struct page *page, struct f2fs_io_info *fio)
739 {
740 struct inode *inode = page->mapping->host;
741 block_t old_blkaddr, new_blkaddr;
742 struct dnode_of_data dn;
743 int err = 0;
744
745 set_new_dnode(&dn, inode, NULL, NULL, 0);
746 err = get_dnode_of_data(&dn, page->index, LOOKUP_NODE);
747 if (err)
748 return err;
749
750 old_blkaddr = dn.data_blkaddr;
751
752 /* This page is already truncated */
753 if (old_blkaddr == NULL_ADDR)
754 goto out_writepage;
755
756 set_page_writeback(page);
757
758 /*
759 * If current allocation needs SSR,
760 * it had better in-place writes for updated data.
761 */
762 if (unlikely(old_blkaddr != NEW_ADDR &&
763 !is_cold_data(page) &&
764 need_inplace_update(inode))) {
765 rewrite_data_page(page, old_blkaddr, fio);
766 } else {
767 write_data_page(page, &dn, &new_blkaddr, fio);
768 update_extent_cache(new_blkaddr, &dn);
769 }
770 out_writepage:
771 f2fs_put_dnode(&dn);
772 return err;
773 }
774
775 static int f2fs_write_data_page(struct page *page,
776 struct writeback_control *wbc)
777 {
778 struct inode *inode = page->mapping->host;
779 struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
780 loff_t i_size = i_size_read(inode);
781 const pgoff_t end_index = ((unsigned long long) i_size)
782 >> PAGE_CACHE_SHIFT;
783 unsigned offset = 0;
784 bool need_balance_fs = false;
785 int err = 0;
786 struct f2fs_io_info fio = {
787 .type = DATA,
788 .rw = (wbc->sync_mode == WB_SYNC_ALL) ? WRITE_SYNC : WRITE,
789 };
790
791 if (page->index < end_index)
792 goto write;
793
794 /*
795 * If the offset is out-of-range of file size,
796 * this page does not have to be written to disk.
797 */
798 offset = i_size & (PAGE_CACHE_SIZE - 1);
799 if ((page->index >= end_index + 1) || !offset) {
800 if (S_ISDIR(inode->i_mode)) {
801 dec_page_count(sbi, F2FS_DIRTY_DENTS);
802 inode_dec_dirty_dents(inode);
803 }
804 goto out;
805 }
806
807 zero_user_segment(page, offset, PAGE_CACHE_SIZE);
808 write:
809 if (unlikely(sbi->por_doing)) {
810 err = AOP_WRITEPAGE_ACTIVATE;
811 goto redirty_out;
812 }
813
814 /* Dentry blocks are controlled by checkpoint */
815 if (S_ISDIR(inode->i_mode)) {
816 dec_page_count(sbi, F2FS_DIRTY_DENTS);
817 inode_dec_dirty_dents(inode);
818 err = do_write_data_page(page, &fio);
819 } else {
820 f2fs_lock_op(sbi);
821
822 if (f2fs_has_inline_data(inode) || f2fs_may_inline(inode)) {
823 err = f2fs_write_inline_data(inode, page, offset);
824 f2fs_unlock_op(sbi);
825 goto out;
826 } else {
827 err = do_write_data_page(page, &fio);
828 }
829
830 f2fs_unlock_op(sbi);
831 need_balance_fs = true;
832 }
833 if (err == -ENOENT)
834 goto out;
835 else if (err)
836 goto redirty_out;
837
838 if (wbc->for_reclaim) {
839 f2fs_submit_merged_bio(sbi, DATA, WRITE);
840 need_balance_fs = false;
841 }
842
843 clear_cold_data(page);
844 out:
845 unlock_page(page);
846 if (need_balance_fs)
847 f2fs_balance_fs(sbi);
848 return 0;
849
850 redirty_out:
851 wbc->pages_skipped++;
852 set_page_dirty(page);
853 return err;
854 }
855
856 #define MAX_DESIRED_PAGES_WP 4096
857
858 static int __f2fs_writepage(struct page *page, struct writeback_control *wbc,
859 void *data)
860 {
861 struct address_space *mapping = data;
862 int ret = mapping->a_ops->writepage(page, wbc);
863 mapping_set_error(mapping, ret);
864 return ret;
865 }
866
867 static int f2fs_write_data_pages(struct address_space *mapping,
868 struct writeback_control *wbc)
869 {
870 struct inode *inode = mapping->host;
871 struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
872 bool locked = false;
873 int ret;
874 long excess_nrtw = 0, desired_nrtw;
875
876 /* deal with chardevs and other special file */
877 if (!mapping->a_ops->writepage)
878 return 0;
879
880 if (wbc->nr_to_write < MAX_DESIRED_PAGES_WP) {
881 desired_nrtw = MAX_DESIRED_PAGES_WP;
882 excess_nrtw = desired_nrtw - wbc->nr_to_write;
883 wbc->nr_to_write = desired_nrtw;
884 }
885
886 if (!S_ISDIR(inode->i_mode)) {
887 mutex_lock(&sbi->writepages);
888 locked = true;
889 }
890 ret = write_cache_pages(mapping, wbc, __f2fs_writepage, mapping);
891 if (locked)
892 mutex_unlock(&sbi->writepages);
893
894 f2fs_submit_merged_bio(sbi, DATA, WRITE);
895
896 remove_dirty_dir_inode(inode);
897
898 wbc->nr_to_write -= excess_nrtw;
899 return ret;
900 }
901
902 static int f2fs_write_begin(struct file *file, struct address_space *mapping,
903 loff_t pos, unsigned len, unsigned flags,
904 struct page **pagep, void **fsdata)
905 {
906 struct inode *inode = mapping->host;
907 struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
908 struct page *page;
909 pgoff_t index = ((unsigned long long) pos) >> PAGE_CACHE_SHIFT;
910 struct dnode_of_data dn;
911 int err = 0;
912
913 f2fs_balance_fs(sbi);
914 repeat:
915 err = f2fs_convert_inline_data(inode, pos + len);
916 if (err)
917 return err;
918
919 page = grab_cache_page_write_begin(mapping, index, flags);
920 if (!page)
921 return -ENOMEM;
922 *pagep = page;
923
924 if (f2fs_has_inline_data(inode) && (pos + len) <= MAX_INLINE_DATA)
925 goto inline_data;
926
927 f2fs_lock_op(sbi);
928 set_new_dnode(&dn, inode, NULL, NULL, 0);
929 err = f2fs_reserve_block(&dn, index);
930 f2fs_unlock_op(sbi);
931
932 if (err) {
933 f2fs_put_page(page, 1);
934 return err;
935 }
936 inline_data:
937 if ((len == PAGE_CACHE_SIZE) || PageUptodate(page))
938 return 0;
939
940 if ((pos & PAGE_CACHE_MASK) >= i_size_read(inode)) {
941 unsigned start = pos & (PAGE_CACHE_SIZE - 1);
942 unsigned end = start + len;
943
944 /* Reading beyond i_size is simple: memset to zero */
945 zero_user_segments(page, 0, start, end, PAGE_CACHE_SIZE);
946 goto out;
947 }
948
949 if (dn.data_blkaddr == NEW_ADDR) {
950 zero_user_segment(page, 0, PAGE_CACHE_SIZE);
951 } else {
952 if (f2fs_has_inline_data(inode))
953 err = f2fs_read_inline_data(inode, page);
954 else
955 err = f2fs_submit_page_bio(sbi, page, dn.data_blkaddr,
956 READ_SYNC);
957 if (err)
958 return err;
959 lock_page(page);
960 if (unlikely(!PageUptodate(page))) {
961 f2fs_put_page(page, 1);
962 return -EIO;
963 }
964 if (unlikely(page->mapping != mapping)) {
965 f2fs_put_page(page, 1);
966 goto repeat;
967 }
968 }
969 out:
970 SetPageUptodate(page);
971 clear_cold_data(page);
972 return 0;
973 }
974
975 static int f2fs_write_end(struct file *file,
976 struct address_space *mapping,
977 loff_t pos, unsigned len, unsigned copied,
978 struct page *page, void *fsdata)
979 {
980 struct inode *inode = page->mapping->host;
981
982 SetPageUptodate(page);
983 set_page_dirty(page);
984
985 if (pos + copied > i_size_read(inode)) {
986 i_size_write(inode, pos + copied);
987 mark_inode_dirty(inode);
988 update_inode_page(inode);
989 }
990
991 f2fs_put_page(page, 1);
992 return copied;
993 }
994
995 static int check_direct_IO(struct inode *inode, int rw,
996 const struct iovec *iov, loff_t offset, unsigned long nr_segs)
997 {
998 unsigned blocksize_mask = inode->i_sb->s_blocksize - 1;
999 int i;
1000
1001 if (rw == READ)
1002 return 0;
1003
1004 if (offset & blocksize_mask)
1005 return -EINVAL;
1006
1007 for (i = 0; i < nr_segs; i++)
1008 if (iov[i].iov_len & blocksize_mask)
1009 return -EINVAL;
1010 return 0;
1011 }
1012
1013 static ssize_t f2fs_direct_IO(int rw, struct kiocb *iocb,
1014 const struct iovec *iov, loff_t offset, unsigned long nr_segs)
1015 {
1016 struct file *file = iocb->ki_filp;
1017 struct inode *inode = file->f_mapping->host;
1018
1019 /* Let buffer I/O handle the inline data case. */
1020 if (f2fs_has_inline_data(inode))
1021 return 0;
1022
1023 if (check_direct_IO(inode, rw, iov, offset, nr_segs))
1024 return 0;
1025
1026 return blockdev_direct_IO(rw, iocb, inode, iov, offset, nr_segs,
1027 get_data_block);
1028 }
1029
1030 static void f2fs_invalidate_data_page(struct page *page, unsigned int offset,
1031 unsigned int length)
1032 {
1033 struct inode *inode = page->mapping->host;
1034 struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
1035 if (S_ISDIR(inode->i_mode) && PageDirty(page)) {
1036 dec_page_count(sbi, F2FS_DIRTY_DENTS);
1037 inode_dec_dirty_dents(inode);
1038 }
1039 ClearPagePrivate(page);
1040 }
1041
1042 static int f2fs_release_data_page(struct page *page, gfp_t wait)
1043 {
1044 ClearPagePrivate(page);
1045 return 1;
1046 }
1047
1048 static int f2fs_set_data_page_dirty(struct page *page)
1049 {
1050 struct address_space *mapping = page->mapping;
1051 struct inode *inode = mapping->host;
1052
1053 trace_f2fs_set_page_dirty(page, DATA);
1054
1055 SetPageUptodate(page);
1056 mark_inode_dirty(inode);
1057
1058 if (!PageDirty(page)) {
1059 __set_page_dirty_nobuffers(page);
1060 set_dirty_dir_page(inode, page);
1061 return 1;
1062 }
1063 return 0;
1064 }
1065
1066 static sector_t f2fs_bmap(struct address_space *mapping, sector_t block)
1067 {
1068 return generic_block_bmap(mapping, block, get_data_block);
1069 }
1070
1071 const struct address_space_operations f2fs_dblock_aops = {
1072 .readpage = f2fs_read_data_page,
1073 .readpages = f2fs_read_data_pages,
1074 .writepage = f2fs_write_data_page,
1075 .writepages = f2fs_write_data_pages,
1076 .write_begin = f2fs_write_begin,
1077 .write_end = f2fs_write_end,
1078 .set_page_dirty = f2fs_set_data_page_dirty,
1079 .invalidatepage = f2fs_invalidate_data_page,
1080 .releasepage = f2fs_release_data_page,
1081 .direct_IO = f2fs_direct_IO,
1082 .bmap = f2fs_bmap,
1083 };
(deprecated) Btrfs devel tree