xref: /openbmc/linux/fs/f2fs/data.c (revision 9cfc5c90)
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/writeback.h>
16 #include <linux/backing-dev.h>
17 #include <linux/pagevec.h>
18 #include <linux/blkdev.h>
19 #include <linux/bio.h>
20 #include <linux/prefetch.h>
21 #include <linux/uio.h>
22 #include <linux/cleancache.h>
23 
24 #include "f2fs.h"
25 #include "node.h"
26 #include "segment.h"
27 #include "trace.h"
28 #include <trace/events/f2fs.h>
29 
30 static void f2fs_read_end_io(struct bio *bio)
31 {
32 	struct bio_vec *bvec;
33 	int i;
34 
35 	if (f2fs_bio_encrypted(bio)) {
36 		if (bio->bi_error) {
37 			f2fs_release_crypto_ctx(bio->bi_private);
38 		} else {
39 			f2fs_end_io_crypto_work(bio->bi_private, bio);
40 			return;
41 		}
42 	}
43 
44 	bio_for_each_segment_all(bvec, bio, i) {
45 		struct page *page = bvec->bv_page;
46 
47 		if (!bio->bi_error) {
48 			SetPageUptodate(page);
49 		} else {
50 			ClearPageUptodate(page);
51 			SetPageError(page);
52 		}
53 		unlock_page(page);
54 	}
55 	bio_put(bio);
56 }
57 
58 static void f2fs_write_end_io(struct bio *bio)
59 {
60 	struct f2fs_sb_info *sbi = bio->bi_private;
61 	struct bio_vec *bvec;
62 	int i;
63 
64 	bio_for_each_segment_all(bvec, bio, i) {
65 		struct page *page = bvec->bv_page;
66 
67 		f2fs_restore_and_release_control_page(&page);
68 
69 		if (unlikely(bio->bi_error)) {
70 			set_page_dirty(page);
71 			set_bit(AS_EIO, &page->mapping->flags);
72 			f2fs_stop_checkpoint(sbi);
73 		}
74 		end_page_writeback(page);
75 		dec_page_count(sbi, F2FS_WRITEBACK);
76 	}
77 
78 	if (!get_pages(sbi, F2FS_WRITEBACK) &&
79 			!list_empty(&sbi->cp_wait.task_list))
80 		wake_up(&sbi->cp_wait);
81 
82 	bio_put(bio);
83 }
84 
85 /*
86  * Low-level block read/write IO operations.
87  */
88 static struct bio *__bio_alloc(struct f2fs_sb_info *sbi, block_t blk_addr,
89 				int npages, bool is_read)
90 {
91 	struct bio *bio;
92 
93 	bio = f2fs_bio_alloc(npages);
94 
95 	bio->bi_bdev = sbi->sb->s_bdev;
96 	bio->bi_iter.bi_sector = SECTOR_FROM_BLOCK(blk_addr);
97 	bio->bi_end_io = is_read ? f2fs_read_end_io : f2fs_write_end_io;
98 	bio->bi_private = is_read ? NULL : sbi;
99 
100 	return bio;
101 }
102 
103 static void __submit_merged_bio(struct f2fs_bio_info *io)
104 {
105 	struct f2fs_io_info *fio = &io->fio;
106 
107 	if (!io->bio)
108 		return;
109 
110 	if (is_read_io(fio->rw))
111 		trace_f2fs_submit_read_bio(io->sbi->sb, fio, io->bio);
112 	else
113 		trace_f2fs_submit_write_bio(io->sbi->sb, fio, io->bio);
114 
115 	submit_bio(fio->rw, io->bio);
116 	io->bio = NULL;
117 }
118 
119 void f2fs_submit_merged_bio(struct f2fs_sb_info *sbi,
120 				enum page_type type, int rw)
121 {
122 	enum page_type btype = PAGE_TYPE_OF_BIO(type);
123 	struct f2fs_bio_info *io;
124 
125 	io = is_read_io(rw) ? &sbi->read_io : &sbi->write_io[btype];
126 
127 	down_write(&io->io_rwsem);
128 
129 	/* change META to META_FLUSH in the checkpoint procedure */
130 	if (type >= META_FLUSH) {
131 		io->fio.type = META_FLUSH;
132 		if (test_opt(sbi, NOBARRIER))
133 			io->fio.rw = WRITE_FLUSH | REQ_META | REQ_PRIO;
134 		else
135 			io->fio.rw = WRITE_FLUSH_FUA | REQ_META | REQ_PRIO;
136 	}
137 	__submit_merged_bio(io);
138 	up_write(&io->io_rwsem);
139 }
140 
141 /*
142  * Fill the locked page with data located in the block address.
143  * Return unlocked page.
144  */
145 int f2fs_submit_page_bio(struct f2fs_io_info *fio)
146 {
147 	struct bio *bio;
148 	struct page *page = fio->encrypted_page ? fio->encrypted_page : fio->page;
149 
150 	trace_f2fs_submit_page_bio(page, fio);
151 	f2fs_trace_ios(fio, 0);
152 
153 	/* Allocate a new bio */
154 	bio = __bio_alloc(fio->sbi, fio->blk_addr, 1, is_read_io(fio->rw));
155 
156 	if (bio_add_page(bio, page, PAGE_CACHE_SIZE, 0) < PAGE_CACHE_SIZE) {
157 		bio_put(bio);
158 		return -EFAULT;
159 	}
160 
161 	submit_bio(fio->rw, bio);
162 	return 0;
163 }
164 
165 void f2fs_submit_page_mbio(struct f2fs_io_info *fio)
166 {
167 	struct f2fs_sb_info *sbi = fio->sbi;
168 	enum page_type btype = PAGE_TYPE_OF_BIO(fio->type);
169 	struct f2fs_bio_info *io;
170 	bool is_read = is_read_io(fio->rw);
171 	struct page *bio_page;
172 
173 	io = is_read ? &sbi->read_io : &sbi->write_io[btype];
174 
175 	verify_block_addr(sbi, fio->blk_addr);
176 
177 	down_write(&io->io_rwsem);
178 
179 	if (!is_read)
180 		inc_page_count(sbi, F2FS_WRITEBACK);
181 
182 	if (io->bio && (io->last_block_in_bio != fio->blk_addr - 1 ||
183 						io->fio.rw != fio->rw))
184 		__submit_merged_bio(io);
185 alloc_new:
186 	if (io->bio == NULL) {
187 		int bio_blocks = MAX_BIO_BLOCKS(sbi);
188 
189 		io->bio = __bio_alloc(sbi, fio->blk_addr, bio_blocks, is_read);
190 		io->fio = *fio;
191 	}
192 
193 	bio_page = fio->encrypted_page ? fio->encrypted_page : fio->page;
194 
195 	if (bio_add_page(io->bio, bio_page, PAGE_CACHE_SIZE, 0) <
196 							PAGE_CACHE_SIZE) {
197 		__submit_merged_bio(io);
198 		goto alloc_new;
199 	}
200 
201 	io->last_block_in_bio = fio->blk_addr;
202 	f2fs_trace_ios(fio, 0);
203 
204 	up_write(&io->io_rwsem);
205 	trace_f2fs_submit_page_mbio(fio->page, fio);
206 }
207 
208 /*
209  * Lock ordering for the change of data block address:
210  * ->data_page
211  *  ->node_page
212  *    update block addresses in the node page
213  */
214 void set_data_blkaddr(struct dnode_of_data *dn)
215 {
216 	struct f2fs_node *rn;
217 	__le32 *addr_array;
218 	struct page *node_page = dn->node_page;
219 	unsigned int ofs_in_node = dn->ofs_in_node;
220 
221 	f2fs_wait_on_page_writeback(node_page, NODE);
222 
223 	rn = F2FS_NODE(node_page);
224 
225 	/* Get physical address of data block */
226 	addr_array = blkaddr_in_node(rn);
227 	addr_array[ofs_in_node] = cpu_to_le32(dn->data_blkaddr);
228 	set_page_dirty(node_page);
229 }
230 
231 int reserve_new_block(struct dnode_of_data *dn)
232 {
233 	struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
234 
235 	if (unlikely(is_inode_flag_set(F2FS_I(dn->inode), FI_NO_ALLOC)))
236 		return -EPERM;
237 	if (unlikely(!inc_valid_block_count(sbi, dn->inode, 1)))
238 		return -ENOSPC;
239 
240 	trace_f2fs_reserve_new_block(dn->inode, dn->nid, dn->ofs_in_node);
241 
242 	dn->data_blkaddr = NEW_ADDR;
243 	set_data_blkaddr(dn);
244 	mark_inode_dirty(dn->inode);
245 	sync_inode_page(dn);
246 	return 0;
247 }
248 
249 int f2fs_reserve_block(struct dnode_of_data *dn, pgoff_t index)
250 {
251 	bool need_put = dn->inode_page ? false : true;
252 	int err;
253 
254 	err = get_dnode_of_data(dn, index, ALLOC_NODE);
255 	if (err)
256 		return err;
257 
258 	if (dn->data_blkaddr == NULL_ADDR)
259 		err = reserve_new_block(dn);
260 	if (err || need_put)
261 		f2fs_put_dnode(dn);
262 	return err;
263 }
264 
265 int f2fs_get_block(struct dnode_of_data *dn, pgoff_t index)
266 {
267 	struct extent_info ei;
268 	struct inode *inode = dn->inode;
269 
270 	if (f2fs_lookup_extent_cache(inode, index, &ei)) {
271 		dn->data_blkaddr = ei.blk + index - ei.fofs;
272 		return 0;
273 	}
274 
275 	return f2fs_reserve_block(dn, index);
276 }
277 
278 struct page *get_read_data_page(struct inode *inode, pgoff_t index,
279 						int rw, bool for_write)
280 {
281 	struct address_space *mapping = inode->i_mapping;
282 	struct dnode_of_data dn;
283 	struct page *page;
284 	struct extent_info ei;
285 	int err;
286 	struct f2fs_io_info fio = {
287 		.sbi = F2FS_I_SB(inode),
288 		.type = DATA,
289 		.rw = rw,
290 		.encrypted_page = NULL,
291 	};
292 
293 	if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode))
294 		return read_mapping_page(mapping, index, NULL);
295 
296 	page = f2fs_grab_cache_page(mapping, index, for_write);
297 	if (!page)
298 		return ERR_PTR(-ENOMEM);
299 
300 	if (f2fs_lookup_extent_cache(inode, index, &ei)) {
301 		dn.data_blkaddr = ei.blk + index - ei.fofs;
302 		goto got_it;
303 	}
304 
305 	set_new_dnode(&dn, inode, NULL, NULL, 0);
306 	err = get_dnode_of_data(&dn, index, LOOKUP_NODE);
307 	if (err)
308 		goto put_err;
309 	f2fs_put_dnode(&dn);
310 
311 	if (unlikely(dn.data_blkaddr == NULL_ADDR)) {
312 		err = -ENOENT;
313 		goto put_err;
314 	}
315 got_it:
316 	if (PageUptodate(page)) {
317 		unlock_page(page);
318 		return page;
319 	}
320 
321 	/*
322 	 * A new dentry page is allocated but not able to be written, since its
323 	 * new inode page couldn't be allocated due to -ENOSPC.
324 	 * In such the case, its blkaddr can be remained as NEW_ADDR.
325 	 * see, f2fs_add_link -> get_new_data_page -> init_inode_metadata.
326 	 */
327 	if (dn.data_blkaddr == NEW_ADDR) {
328 		zero_user_segment(page, 0, PAGE_CACHE_SIZE);
329 		SetPageUptodate(page);
330 		unlock_page(page);
331 		return page;
332 	}
333 
334 	fio.blk_addr = dn.data_blkaddr;
335 	fio.page = page;
336 	err = f2fs_submit_page_bio(&fio);
337 	if (err)
338 		goto put_err;
339 	return page;
340 
341 put_err:
342 	f2fs_put_page(page, 1);
343 	return ERR_PTR(err);
344 }
345 
346 struct page *find_data_page(struct inode *inode, pgoff_t index)
347 {
348 	struct address_space *mapping = inode->i_mapping;
349 	struct page *page;
350 
351 	page = find_get_page(mapping, index);
352 	if (page && PageUptodate(page))
353 		return page;
354 	f2fs_put_page(page, 0);
355 
356 	page = get_read_data_page(inode, index, READ_SYNC, false);
357 	if (IS_ERR(page))
358 		return page;
359 
360 	if (PageUptodate(page))
361 		return page;
362 
363 	wait_on_page_locked(page);
364 	if (unlikely(!PageUptodate(page))) {
365 		f2fs_put_page(page, 0);
366 		return ERR_PTR(-EIO);
367 	}
368 	return page;
369 }
370 
371 /*
372  * If it tries to access a hole, return an error.
373  * Because, the callers, functions in dir.c and GC, should be able to know
374  * whether this page exists or not.
375  */
376 struct page *get_lock_data_page(struct inode *inode, pgoff_t index,
377 							bool for_write)
378 {
379 	struct address_space *mapping = inode->i_mapping;
380 	struct page *page;
381 repeat:
382 	page = get_read_data_page(inode, index, READ_SYNC, for_write);
383 	if (IS_ERR(page))
384 		return page;
385 
386 	/* wait for read completion */
387 	lock_page(page);
388 	if (unlikely(!PageUptodate(page))) {
389 		f2fs_put_page(page, 1);
390 		return ERR_PTR(-EIO);
391 	}
392 	if (unlikely(page->mapping != mapping)) {
393 		f2fs_put_page(page, 1);
394 		goto repeat;
395 	}
396 	return page;
397 }
398 
399 /*
400  * Caller ensures that this data page is never allocated.
401  * A new zero-filled data page is allocated in the page cache.
402  *
403  * Also, caller should grab and release a rwsem by calling f2fs_lock_op() and
404  * f2fs_unlock_op().
405  * Note that, ipage is set only by make_empty_dir, and if any error occur,
406  * ipage should be released by this function.
407  */
408 struct page *get_new_data_page(struct inode *inode,
409 		struct page *ipage, pgoff_t index, bool new_i_size)
410 {
411 	struct address_space *mapping = inode->i_mapping;
412 	struct page *page;
413 	struct dnode_of_data dn;
414 	int err;
415 repeat:
416 	page = f2fs_grab_cache_page(mapping, index, true);
417 	if (!page) {
418 		/*
419 		 * before exiting, we should make sure ipage will be released
420 		 * if any error occur.
421 		 */
422 		f2fs_put_page(ipage, 1);
423 		return ERR_PTR(-ENOMEM);
424 	}
425 
426 	set_new_dnode(&dn, inode, ipage, NULL, 0);
427 	err = f2fs_reserve_block(&dn, index);
428 	if (err) {
429 		f2fs_put_page(page, 1);
430 		return ERR_PTR(err);
431 	}
432 	if (!ipage)
433 		f2fs_put_dnode(&dn);
434 
435 	if (PageUptodate(page))
436 		goto got_it;
437 
438 	if (dn.data_blkaddr == NEW_ADDR) {
439 		zero_user_segment(page, 0, PAGE_CACHE_SIZE);
440 		SetPageUptodate(page);
441 	} else {
442 		f2fs_put_page(page, 1);
443 
444 		page = get_read_data_page(inode, index, READ_SYNC, true);
445 		if (IS_ERR(page))
446 			goto repeat;
447 
448 		/* wait for read completion */
449 		lock_page(page);
450 	}
451 got_it:
452 	if (new_i_size && i_size_read(inode) <
453 				((loff_t)(index + 1) << PAGE_CACHE_SHIFT)) {
454 		i_size_write(inode, ((loff_t)(index + 1) << PAGE_CACHE_SHIFT));
455 		/* Only the directory inode sets new_i_size */
456 		set_inode_flag(F2FS_I(inode), FI_UPDATE_DIR);
457 	}
458 	return page;
459 }
460 
461 static int __allocate_data_block(struct dnode_of_data *dn)
462 {
463 	struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
464 	struct f2fs_inode_info *fi = F2FS_I(dn->inode);
465 	struct f2fs_summary sum;
466 	struct node_info ni;
467 	int seg = CURSEG_WARM_DATA;
468 	pgoff_t fofs;
469 
470 	if (unlikely(is_inode_flag_set(F2FS_I(dn->inode), FI_NO_ALLOC)))
471 		return -EPERM;
472 
473 	dn->data_blkaddr = datablock_addr(dn->node_page, dn->ofs_in_node);
474 	if (dn->data_blkaddr == NEW_ADDR)
475 		goto alloc;
476 
477 	if (unlikely(!inc_valid_block_count(sbi, dn->inode, 1)))
478 		return -ENOSPC;
479 
480 alloc:
481 	get_node_info(sbi, dn->nid, &ni);
482 	set_summary(&sum, dn->nid, dn->ofs_in_node, ni.version);
483 
484 	if (dn->ofs_in_node == 0 && dn->inode_page == dn->node_page)
485 		seg = CURSEG_DIRECT_IO;
486 
487 	allocate_data_block(sbi, NULL, dn->data_blkaddr, &dn->data_blkaddr,
488 								&sum, seg);
489 	set_data_blkaddr(dn);
490 
491 	/* update i_size */
492 	fofs = start_bidx_of_node(ofs_of_node(dn->node_page), fi) +
493 							dn->ofs_in_node;
494 	if (i_size_read(dn->inode) < ((loff_t)(fofs + 1) << PAGE_CACHE_SHIFT))
495 		i_size_write(dn->inode,
496 				((loff_t)(fofs + 1) << PAGE_CACHE_SHIFT));
497 
498 	/* direct IO doesn't use extent cache to maximize the performance */
499 	f2fs_drop_largest_extent(dn->inode, fofs);
500 
501 	return 0;
502 }
503 
504 static void __allocate_data_blocks(struct inode *inode, loff_t offset,
505 							size_t count)
506 {
507 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
508 	struct dnode_of_data dn;
509 	u64 start = F2FS_BYTES_TO_BLK(offset);
510 	u64 len = F2FS_BYTES_TO_BLK(count);
511 	bool allocated;
512 	u64 end_offset;
513 
514 	while (len) {
515 		f2fs_balance_fs(sbi);
516 		f2fs_lock_op(sbi);
517 
518 		/* When reading holes, we need its node page */
519 		set_new_dnode(&dn, inode, NULL, NULL, 0);
520 		if (get_dnode_of_data(&dn, start, ALLOC_NODE))
521 			goto out;
522 
523 		allocated = false;
524 		end_offset = ADDRS_PER_PAGE(dn.node_page, F2FS_I(inode));
525 
526 		while (dn.ofs_in_node < end_offset && len) {
527 			block_t blkaddr;
528 
529 			if (unlikely(f2fs_cp_error(sbi)))
530 				goto sync_out;
531 
532 			blkaddr = datablock_addr(dn.node_page, dn.ofs_in_node);
533 			if (blkaddr == NULL_ADDR || blkaddr == NEW_ADDR) {
534 				if (__allocate_data_block(&dn))
535 					goto sync_out;
536 				allocated = true;
537 			}
538 			len--;
539 			start++;
540 			dn.ofs_in_node++;
541 		}
542 
543 		if (allocated)
544 			sync_inode_page(&dn);
545 
546 		f2fs_put_dnode(&dn);
547 		f2fs_unlock_op(sbi);
548 	}
549 	return;
550 
551 sync_out:
552 	if (allocated)
553 		sync_inode_page(&dn);
554 	f2fs_put_dnode(&dn);
555 out:
556 	f2fs_unlock_op(sbi);
557 	return;
558 }
559 
560 /*
561  * f2fs_map_blocks() now supported readahead/bmap/rw direct_IO with
562  * f2fs_map_blocks structure.
563  * If original data blocks are allocated, then give them to blockdev.
564  * Otherwise,
565  *     a. preallocate requested block addresses
566  *     b. do not use extent cache for better performance
567  *     c. give the block addresses to blockdev
568  */
569 static int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map,
570 						int create, int flag)
571 {
572 	unsigned int maxblocks = map->m_len;
573 	struct dnode_of_data dn;
574 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
575 	int mode = create ? ALLOC_NODE : LOOKUP_NODE_RA;
576 	pgoff_t pgofs, end_offset;
577 	int err = 0, ofs = 1;
578 	struct extent_info ei;
579 	bool allocated = false;
580 
581 	map->m_len = 0;
582 	map->m_flags = 0;
583 
584 	/* it only supports block size == page size */
585 	pgofs =	(pgoff_t)map->m_lblk;
586 
587 	if (f2fs_lookup_extent_cache(inode, pgofs, &ei)) {
588 		map->m_pblk = ei.blk + pgofs - ei.fofs;
589 		map->m_len = min((pgoff_t)maxblocks, ei.fofs + ei.len - pgofs);
590 		map->m_flags = F2FS_MAP_MAPPED;
591 		goto out;
592 	}
593 
594 	if (create)
595 		f2fs_lock_op(F2FS_I_SB(inode));
596 
597 	/* When reading holes, we need its node page */
598 	set_new_dnode(&dn, inode, NULL, NULL, 0);
599 	err = get_dnode_of_data(&dn, pgofs, mode);
600 	if (err) {
601 		if (err == -ENOENT)
602 			err = 0;
603 		goto unlock_out;
604 	}
605 
606 	if (dn.data_blkaddr == NEW_ADDR || dn.data_blkaddr == NULL_ADDR) {
607 		if (create) {
608 			if (unlikely(f2fs_cp_error(sbi))) {
609 				err = -EIO;
610 				goto put_out;
611 			}
612 			err = __allocate_data_block(&dn);
613 			if (err)
614 				goto put_out;
615 			allocated = true;
616 			map->m_flags = F2FS_MAP_NEW;
617 		} else {
618 			if (flag != F2FS_GET_BLOCK_FIEMAP ||
619 						dn.data_blkaddr != NEW_ADDR) {
620 				if (flag == F2FS_GET_BLOCK_BMAP)
621 					err = -ENOENT;
622 				goto put_out;
623 			}
624 
625 			/*
626 			 * preallocated unwritten block should be mapped
627 			 * for fiemap.
628 			 */
629 			if (dn.data_blkaddr == NEW_ADDR)
630 				map->m_flags = F2FS_MAP_UNWRITTEN;
631 		}
632 	}
633 
634 	map->m_flags |= F2FS_MAP_MAPPED;
635 	map->m_pblk = dn.data_blkaddr;
636 	map->m_len = 1;
637 
638 	end_offset = ADDRS_PER_PAGE(dn.node_page, F2FS_I(inode));
639 	dn.ofs_in_node++;
640 	pgofs++;
641 
642 get_next:
643 	if (dn.ofs_in_node >= end_offset) {
644 		if (allocated)
645 			sync_inode_page(&dn);
646 		allocated = false;
647 		f2fs_put_dnode(&dn);
648 
649 		set_new_dnode(&dn, inode, NULL, NULL, 0);
650 		err = get_dnode_of_data(&dn, pgofs, mode);
651 		if (err) {
652 			if (err == -ENOENT)
653 				err = 0;
654 			goto unlock_out;
655 		}
656 
657 		end_offset = ADDRS_PER_PAGE(dn.node_page, F2FS_I(inode));
658 	}
659 
660 	if (maxblocks > map->m_len) {
661 		block_t blkaddr = datablock_addr(dn.node_page, dn.ofs_in_node);
662 
663 		if (blkaddr == NEW_ADDR || blkaddr == NULL_ADDR) {
664 			if (create) {
665 				if (unlikely(f2fs_cp_error(sbi))) {
666 					err = -EIO;
667 					goto sync_out;
668 				}
669 				err = __allocate_data_block(&dn);
670 				if (err)
671 					goto sync_out;
672 				allocated = true;
673 				map->m_flags |= F2FS_MAP_NEW;
674 				blkaddr = dn.data_blkaddr;
675 			} else {
676 				/*
677 				 * we only merge preallocated unwritten blocks
678 				 * for fiemap.
679 				 */
680 				if (flag != F2FS_GET_BLOCK_FIEMAP ||
681 						blkaddr != NEW_ADDR)
682 					goto sync_out;
683 			}
684 		}
685 
686 		/* Give more consecutive addresses for the readahead */
687 		if ((map->m_pblk != NEW_ADDR &&
688 				blkaddr == (map->m_pblk + ofs)) ||
689 				(map->m_pblk == NEW_ADDR &&
690 				blkaddr == NEW_ADDR)) {
691 			ofs++;
692 			dn.ofs_in_node++;
693 			pgofs++;
694 			map->m_len++;
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(F2FS_I_SB(inode));
706 out:
707 	trace_f2fs_map_blocks(inode, map, err);
708 	return err;
709 }
710 
711 static int __get_data_block(struct inode *inode, sector_t iblock,
712 			struct buffer_head *bh, int create, int flag)
713 {
714 	struct f2fs_map_blocks map;
715 	int ret;
716 
717 	map.m_lblk = iblock;
718 	map.m_len = bh->b_size >> inode->i_blkbits;
719 
720 	ret = f2fs_map_blocks(inode, &map, create, flag);
721 	if (!ret) {
722 		map_bh(bh, inode->i_sb, map.m_pblk);
723 		bh->b_state = (bh->b_state & ~F2FS_MAP_FLAGS) | map.m_flags;
724 		bh->b_size = map.m_len << inode->i_blkbits;
725 	}
726 	return ret;
727 }
728 
729 static int get_data_block(struct inode *inode, sector_t iblock,
730 			struct buffer_head *bh_result, int create, int flag)
731 {
732 	return __get_data_block(inode, iblock, bh_result, create, flag);
733 }
734 
735 static int get_data_block_dio(struct inode *inode, sector_t iblock,
736 			struct buffer_head *bh_result, int create)
737 {
738 	return __get_data_block(inode, iblock, bh_result, create,
739 						F2FS_GET_BLOCK_DIO);
740 }
741 
742 static int get_data_block_bmap(struct inode *inode, sector_t iblock,
743 			struct buffer_head *bh_result, int create)
744 {
745 	return __get_data_block(inode, iblock, bh_result, create,
746 						F2FS_GET_BLOCK_BMAP);
747 }
748 
749 static inline sector_t logical_to_blk(struct inode *inode, loff_t offset)
750 {
751 	return (offset >> inode->i_blkbits);
752 }
753 
754 static inline loff_t blk_to_logical(struct inode *inode, sector_t blk)
755 {
756 	return (blk << inode->i_blkbits);
757 }
758 
759 int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
760 		u64 start, u64 len)
761 {
762 	struct buffer_head map_bh;
763 	sector_t start_blk, last_blk;
764 	loff_t isize = i_size_read(inode);
765 	u64 logical = 0, phys = 0, size = 0;
766 	u32 flags = 0;
767 	bool past_eof = false, whole_file = false;
768 	int ret = 0;
769 
770 	ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC);
771 	if (ret)
772 		return ret;
773 
774 	if (f2fs_has_inline_data(inode)) {
775 		ret = f2fs_inline_data_fiemap(inode, fieinfo, start, len);
776 		if (ret != -EAGAIN)
777 			return ret;
778 	}
779 
780 	mutex_lock(&inode->i_mutex);
781 
782 	if (len >= isize) {
783 		whole_file = true;
784 		len = isize;
785 	}
786 
787 	if (logical_to_blk(inode, len) == 0)
788 		len = blk_to_logical(inode, 1);
789 
790 	start_blk = logical_to_blk(inode, start);
791 	last_blk = logical_to_blk(inode, start + len - 1);
792 next:
793 	memset(&map_bh, 0, sizeof(struct buffer_head));
794 	map_bh.b_size = len;
795 
796 	ret = get_data_block(inode, start_blk, &map_bh, 0,
797 					F2FS_GET_BLOCK_FIEMAP);
798 	if (ret)
799 		goto out;
800 
801 	/* HOLE */
802 	if (!buffer_mapped(&map_bh)) {
803 		start_blk++;
804 
805 		if (!past_eof && blk_to_logical(inode, start_blk) >= isize)
806 			past_eof = 1;
807 
808 		if (past_eof && size) {
809 			flags |= FIEMAP_EXTENT_LAST;
810 			ret = fiemap_fill_next_extent(fieinfo, logical,
811 					phys, size, flags);
812 		} else if (size) {
813 			ret = fiemap_fill_next_extent(fieinfo, logical,
814 					phys, size, flags);
815 			size = 0;
816 		}
817 
818 		/* if we have holes up to/past EOF then we're done */
819 		if (start_blk > last_blk || past_eof || ret)
820 			goto out;
821 	} else {
822 		if (start_blk > last_blk && !whole_file) {
823 			ret = fiemap_fill_next_extent(fieinfo, logical,
824 					phys, size, flags);
825 			goto out;
826 		}
827 
828 		/*
829 		 * if size != 0 then we know we already have an extent
830 		 * to add, so add it.
831 		 */
832 		if (size) {
833 			ret = fiemap_fill_next_extent(fieinfo, logical,
834 					phys, size, flags);
835 			if (ret)
836 				goto out;
837 		}
838 
839 		logical = blk_to_logical(inode, start_blk);
840 		phys = blk_to_logical(inode, map_bh.b_blocknr);
841 		size = map_bh.b_size;
842 		flags = 0;
843 		if (buffer_unwritten(&map_bh))
844 			flags = FIEMAP_EXTENT_UNWRITTEN;
845 
846 		start_blk += logical_to_blk(inode, size);
847 
848 		/*
849 		 * If we are past the EOF, then we need to make sure as
850 		 * soon as we find a hole that the last extent we found
851 		 * is marked with FIEMAP_EXTENT_LAST
852 		 */
853 		if (!past_eof && logical + size >= isize)
854 			past_eof = true;
855 	}
856 	cond_resched();
857 	if (fatal_signal_pending(current))
858 		ret = -EINTR;
859 	else
860 		goto next;
861 out:
862 	if (ret == 1)
863 		ret = 0;
864 
865 	mutex_unlock(&inode->i_mutex);
866 	return ret;
867 }
868 
869 /*
870  * This function was originally taken from fs/mpage.c, and customized for f2fs.
871  * Major change was from block_size == page_size in f2fs by default.
872  */
873 static int f2fs_mpage_readpages(struct address_space *mapping,
874 			struct list_head *pages, struct page *page,
875 			unsigned nr_pages)
876 {
877 	struct bio *bio = NULL;
878 	unsigned page_idx;
879 	sector_t last_block_in_bio = 0;
880 	struct inode *inode = mapping->host;
881 	const unsigned blkbits = inode->i_blkbits;
882 	const unsigned blocksize = 1 << blkbits;
883 	sector_t block_in_file;
884 	sector_t last_block;
885 	sector_t last_block_in_file;
886 	sector_t block_nr;
887 	struct block_device *bdev = inode->i_sb->s_bdev;
888 	struct f2fs_map_blocks map;
889 
890 	map.m_pblk = 0;
891 	map.m_lblk = 0;
892 	map.m_len = 0;
893 	map.m_flags = 0;
894 
895 	for (page_idx = 0; nr_pages; page_idx++, nr_pages--) {
896 
897 		prefetchw(&page->flags);
898 		if (pages) {
899 			page = list_entry(pages->prev, struct page, lru);
900 			list_del(&page->lru);
901 			if (add_to_page_cache_lru(page, mapping,
902 						  page->index, GFP_KERNEL))
903 				goto next_page;
904 		}
905 
906 		block_in_file = (sector_t)page->index;
907 		last_block = block_in_file + nr_pages;
908 		last_block_in_file = (i_size_read(inode) + blocksize - 1) >>
909 								blkbits;
910 		if (last_block > last_block_in_file)
911 			last_block = last_block_in_file;
912 
913 		/*
914 		 * Map blocks using the previous result first.
915 		 */
916 		if ((map.m_flags & F2FS_MAP_MAPPED) &&
917 				block_in_file > map.m_lblk &&
918 				block_in_file < (map.m_lblk + map.m_len))
919 			goto got_it;
920 
921 		/*
922 		 * Then do more f2fs_map_blocks() calls until we are
923 		 * done with this page.
924 		 */
925 		map.m_flags = 0;
926 
927 		if (block_in_file < last_block) {
928 			map.m_lblk = block_in_file;
929 			map.m_len = last_block - block_in_file;
930 
931 			if (f2fs_map_blocks(inode, &map, 0,
932 							F2FS_GET_BLOCK_READ))
933 				goto set_error_page;
934 		}
935 got_it:
936 		if ((map.m_flags & F2FS_MAP_MAPPED)) {
937 			block_nr = map.m_pblk + block_in_file - map.m_lblk;
938 			SetPageMappedToDisk(page);
939 
940 			if (!PageUptodate(page) && !cleancache_get_page(page)) {
941 				SetPageUptodate(page);
942 				goto confused;
943 			}
944 		} else {
945 			zero_user_segment(page, 0, PAGE_CACHE_SIZE);
946 			SetPageUptodate(page);
947 			unlock_page(page);
948 			goto next_page;
949 		}
950 
951 		/*
952 		 * This page will go to BIO.  Do we need to send this
953 		 * BIO off first?
954 		 */
955 		if (bio && (last_block_in_bio != block_nr - 1)) {
956 submit_and_realloc:
957 			submit_bio(READ, bio);
958 			bio = NULL;
959 		}
960 		if (bio == NULL) {
961 			struct f2fs_crypto_ctx *ctx = NULL;
962 
963 			if (f2fs_encrypted_inode(inode) &&
964 					S_ISREG(inode->i_mode)) {
965 
966 				ctx = f2fs_get_crypto_ctx(inode);
967 				if (IS_ERR(ctx))
968 					goto set_error_page;
969 
970 				/* wait the page to be moved by cleaning */
971 				f2fs_wait_on_encrypted_page_writeback(
972 						F2FS_I_SB(inode), block_nr);
973 			}
974 
975 			bio = bio_alloc(GFP_KERNEL,
976 				min_t(int, nr_pages, BIO_MAX_PAGES));
977 			if (!bio) {
978 				if (ctx)
979 					f2fs_release_crypto_ctx(ctx);
980 				goto set_error_page;
981 			}
982 			bio->bi_bdev = bdev;
983 			bio->bi_iter.bi_sector = SECTOR_FROM_BLOCK(block_nr);
984 			bio->bi_end_io = f2fs_read_end_io;
985 			bio->bi_private = ctx;
986 		}
987 
988 		if (bio_add_page(bio, page, blocksize, 0) < blocksize)
989 			goto submit_and_realloc;
990 
991 		last_block_in_bio = block_nr;
992 		goto next_page;
993 set_error_page:
994 		SetPageError(page);
995 		zero_user_segment(page, 0, PAGE_CACHE_SIZE);
996 		unlock_page(page);
997 		goto next_page;
998 confused:
999 		if (bio) {
1000 			submit_bio(READ, bio);
1001 			bio = NULL;
1002 		}
1003 		unlock_page(page);
1004 next_page:
1005 		if (pages)
1006 			page_cache_release(page);
1007 	}
1008 	BUG_ON(pages && !list_empty(pages));
1009 	if (bio)
1010 		submit_bio(READ, bio);
1011 	return 0;
1012 }
1013 
1014 static int f2fs_read_data_page(struct file *file, struct page *page)
1015 {
1016 	struct inode *inode = page->mapping->host;
1017 	int ret = -EAGAIN;
1018 
1019 	trace_f2fs_readpage(page, DATA);
1020 
1021 	/* If the file has inline data, try to read it directly */
1022 	if (f2fs_has_inline_data(inode))
1023 		ret = f2fs_read_inline_data(inode, page);
1024 	if (ret == -EAGAIN)
1025 		ret = f2fs_mpage_readpages(page->mapping, NULL, page, 1);
1026 	return ret;
1027 }
1028 
1029 static int f2fs_read_data_pages(struct file *file,
1030 			struct address_space *mapping,
1031 			struct list_head *pages, unsigned nr_pages)
1032 {
1033 	struct inode *inode = file->f_mapping->host;
1034 	struct page *page = list_entry(pages->prev, struct page, lru);
1035 
1036 	trace_f2fs_readpages(inode, page, nr_pages);
1037 
1038 	/* If the file has inline data, skip readpages */
1039 	if (f2fs_has_inline_data(inode))
1040 		return 0;
1041 
1042 	return f2fs_mpage_readpages(mapping, pages, NULL, nr_pages);
1043 }
1044 
1045 int do_write_data_page(struct f2fs_io_info *fio)
1046 {
1047 	struct page *page = fio->page;
1048 	struct inode *inode = page->mapping->host;
1049 	struct dnode_of_data dn;
1050 	int err = 0;
1051 
1052 	set_new_dnode(&dn, inode, NULL, NULL, 0);
1053 	err = get_dnode_of_data(&dn, page->index, LOOKUP_NODE);
1054 	if (err)
1055 		return err;
1056 
1057 	fio->blk_addr = dn.data_blkaddr;
1058 
1059 	/* This page is already truncated */
1060 	if (fio->blk_addr == NULL_ADDR) {
1061 		ClearPageUptodate(page);
1062 		goto out_writepage;
1063 	}
1064 
1065 	if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode)) {
1066 
1067 		/* wait for GCed encrypted page writeback */
1068 		f2fs_wait_on_encrypted_page_writeback(F2FS_I_SB(inode),
1069 							fio->blk_addr);
1070 
1071 		fio->encrypted_page = f2fs_encrypt(inode, fio->page);
1072 		if (IS_ERR(fio->encrypted_page)) {
1073 			err = PTR_ERR(fio->encrypted_page);
1074 			goto out_writepage;
1075 		}
1076 	}
1077 
1078 	set_page_writeback(page);
1079 
1080 	/*
1081 	 * If current allocation needs SSR,
1082 	 * it had better in-place writes for updated data.
1083 	 */
1084 	if (unlikely(fio->blk_addr != NEW_ADDR &&
1085 			!is_cold_data(page) &&
1086 			need_inplace_update(inode))) {
1087 		rewrite_data_page(fio);
1088 		set_inode_flag(F2FS_I(inode), FI_UPDATE_WRITE);
1089 		trace_f2fs_do_write_data_page(page, IPU);
1090 	} else {
1091 		write_data_page(&dn, fio);
1092 		set_data_blkaddr(&dn);
1093 		f2fs_update_extent_cache(&dn);
1094 		trace_f2fs_do_write_data_page(page, OPU);
1095 		set_inode_flag(F2FS_I(inode), FI_APPEND_WRITE);
1096 		if (page->index == 0)
1097 			set_inode_flag(F2FS_I(inode), FI_FIRST_BLOCK_WRITTEN);
1098 	}
1099 out_writepage:
1100 	f2fs_put_dnode(&dn);
1101 	return err;
1102 }
1103 
1104 static int f2fs_write_data_page(struct page *page,
1105 					struct writeback_control *wbc)
1106 {
1107 	struct inode *inode = page->mapping->host;
1108 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1109 	loff_t i_size = i_size_read(inode);
1110 	const pgoff_t end_index = ((unsigned long long) i_size)
1111 							>> PAGE_CACHE_SHIFT;
1112 	unsigned offset = 0;
1113 	bool need_balance_fs = false;
1114 	int err = 0;
1115 	struct f2fs_io_info fio = {
1116 		.sbi = sbi,
1117 		.type = DATA,
1118 		.rw = (wbc->sync_mode == WB_SYNC_ALL) ? WRITE_SYNC : WRITE,
1119 		.page = page,
1120 		.encrypted_page = NULL,
1121 	};
1122 
1123 	trace_f2fs_writepage(page, DATA);
1124 
1125 	if (page->index < end_index)
1126 		goto write;
1127 
1128 	/*
1129 	 * If the offset is out-of-range of file size,
1130 	 * this page does not have to be written to disk.
1131 	 */
1132 	offset = i_size & (PAGE_CACHE_SIZE - 1);
1133 	if ((page->index >= end_index + 1) || !offset)
1134 		goto out;
1135 
1136 	zero_user_segment(page, offset, PAGE_CACHE_SIZE);
1137 write:
1138 	if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
1139 		goto redirty_out;
1140 	if (f2fs_is_drop_cache(inode))
1141 		goto out;
1142 	if (f2fs_is_volatile_file(inode) && !wbc->for_reclaim &&
1143 			available_free_memory(sbi, BASE_CHECK))
1144 		goto redirty_out;
1145 
1146 	/* Dentry blocks are controlled by checkpoint */
1147 	if (S_ISDIR(inode->i_mode)) {
1148 		if (unlikely(f2fs_cp_error(sbi)))
1149 			goto redirty_out;
1150 		err = do_write_data_page(&fio);
1151 		goto done;
1152 	}
1153 
1154 	/* we should bypass data pages to proceed the kworkder jobs */
1155 	if (unlikely(f2fs_cp_error(sbi))) {
1156 		SetPageError(page);
1157 		goto out;
1158 	}
1159 
1160 	if (!wbc->for_reclaim)
1161 		need_balance_fs = true;
1162 	else if (has_not_enough_free_secs(sbi, 0))
1163 		goto redirty_out;
1164 
1165 	err = -EAGAIN;
1166 	f2fs_lock_op(sbi);
1167 	if (f2fs_has_inline_data(inode))
1168 		err = f2fs_write_inline_data(inode, page);
1169 	if (err == -EAGAIN)
1170 		err = do_write_data_page(&fio);
1171 	f2fs_unlock_op(sbi);
1172 done:
1173 	if (err && err != -ENOENT)
1174 		goto redirty_out;
1175 
1176 	clear_cold_data(page);
1177 out:
1178 	inode_dec_dirty_pages(inode);
1179 	if (err)
1180 		ClearPageUptodate(page);
1181 	unlock_page(page);
1182 	if (need_balance_fs)
1183 		f2fs_balance_fs(sbi);
1184 	if (wbc->for_reclaim)
1185 		f2fs_submit_merged_bio(sbi, DATA, WRITE);
1186 	return 0;
1187 
1188 redirty_out:
1189 	redirty_page_for_writepage(wbc, page);
1190 	return AOP_WRITEPAGE_ACTIVATE;
1191 }
1192 
1193 static int __f2fs_writepage(struct page *page, struct writeback_control *wbc,
1194 			void *data)
1195 {
1196 	struct address_space *mapping = data;
1197 	int ret = mapping->a_ops->writepage(page, wbc);
1198 	mapping_set_error(mapping, ret);
1199 	return ret;
1200 }
1201 
1202 /*
1203  * This function was copied from write_cche_pages from mm/page-writeback.c.
1204  * The major change is making write step of cold data page separately from
1205  * warm/hot data page.
1206  */
1207 static int f2fs_write_cache_pages(struct address_space *mapping,
1208 			struct writeback_control *wbc, writepage_t writepage,
1209 			void *data)
1210 {
1211 	int ret = 0;
1212 	int done = 0;
1213 	struct pagevec pvec;
1214 	int nr_pages;
1215 	pgoff_t uninitialized_var(writeback_index);
1216 	pgoff_t index;
1217 	pgoff_t end;		/* Inclusive */
1218 	pgoff_t done_index;
1219 	int cycled;
1220 	int range_whole = 0;
1221 	int tag;
1222 	int step = 0;
1223 
1224 	pagevec_init(&pvec, 0);
1225 next:
1226 	if (wbc->range_cyclic) {
1227 		writeback_index = mapping->writeback_index; /* prev offset */
1228 		index = writeback_index;
1229 		if (index == 0)
1230 			cycled = 1;
1231 		else
1232 			cycled = 0;
1233 		end = -1;
1234 	} else {
1235 		index = wbc->range_start >> PAGE_CACHE_SHIFT;
1236 		end = wbc->range_end >> PAGE_CACHE_SHIFT;
1237 		if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
1238 			range_whole = 1;
1239 		cycled = 1; /* ignore range_cyclic tests */
1240 	}
1241 	if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
1242 		tag = PAGECACHE_TAG_TOWRITE;
1243 	else
1244 		tag = PAGECACHE_TAG_DIRTY;
1245 retry:
1246 	if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
1247 		tag_pages_for_writeback(mapping, index, end);
1248 	done_index = index;
1249 	while (!done && (index <= end)) {
1250 		int i;
1251 
1252 		nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
1253 			      min(end - index, (pgoff_t)PAGEVEC_SIZE - 1) + 1);
1254 		if (nr_pages == 0)
1255 			break;
1256 
1257 		for (i = 0; i < nr_pages; i++) {
1258 			struct page *page = pvec.pages[i];
1259 
1260 			if (page->index > end) {
1261 				done = 1;
1262 				break;
1263 			}
1264 
1265 			done_index = page->index;
1266 
1267 			lock_page(page);
1268 
1269 			if (unlikely(page->mapping != mapping)) {
1270 continue_unlock:
1271 				unlock_page(page);
1272 				continue;
1273 			}
1274 
1275 			if (!PageDirty(page)) {
1276 				/* someone wrote it for us */
1277 				goto continue_unlock;
1278 			}
1279 
1280 			if (step == is_cold_data(page))
1281 				goto continue_unlock;
1282 
1283 			if (PageWriteback(page)) {
1284 				if (wbc->sync_mode != WB_SYNC_NONE)
1285 					f2fs_wait_on_page_writeback(page, DATA);
1286 				else
1287 					goto continue_unlock;
1288 			}
1289 
1290 			BUG_ON(PageWriteback(page));
1291 			if (!clear_page_dirty_for_io(page))
1292 				goto continue_unlock;
1293 
1294 			ret = (*writepage)(page, wbc, data);
1295 			if (unlikely(ret)) {
1296 				if (ret == AOP_WRITEPAGE_ACTIVATE) {
1297 					unlock_page(page);
1298 					ret = 0;
1299 				} else {
1300 					done_index = page->index + 1;
1301 					done = 1;
1302 					break;
1303 				}
1304 			}
1305 
1306 			if (--wbc->nr_to_write <= 0 &&
1307 			    wbc->sync_mode == WB_SYNC_NONE) {
1308 				done = 1;
1309 				break;
1310 			}
1311 		}
1312 		pagevec_release(&pvec);
1313 		cond_resched();
1314 	}
1315 
1316 	if (step < 1) {
1317 		step++;
1318 		goto next;
1319 	}
1320 
1321 	if (!cycled && !done) {
1322 		cycled = 1;
1323 		index = 0;
1324 		end = writeback_index - 1;
1325 		goto retry;
1326 	}
1327 	if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
1328 		mapping->writeback_index = done_index;
1329 
1330 	return ret;
1331 }
1332 
1333 static int f2fs_write_data_pages(struct address_space *mapping,
1334 			    struct writeback_control *wbc)
1335 {
1336 	struct inode *inode = mapping->host;
1337 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1338 	bool locked = false;
1339 	int ret;
1340 	long diff;
1341 
1342 	trace_f2fs_writepages(mapping->host, wbc, DATA);
1343 
1344 	/* deal with chardevs and other special file */
1345 	if (!mapping->a_ops->writepage)
1346 		return 0;
1347 
1348 	/* skip writing if there is no dirty page in this inode */
1349 	if (!get_dirty_pages(inode) && wbc->sync_mode == WB_SYNC_NONE)
1350 		return 0;
1351 
1352 	if (S_ISDIR(inode->i_mode) && wbc->sync_mode == WB_SYNC_NONE &&
1353 			get_dirty_pages(inode) < nr_pages_to_skip(sbi, DATA) &&
1354 			available_free_memory(sbi, DIRTY_DENTS))
1355 		goto skip_write;
1356 
1357 	/* during POR, we don't need to trigger writepage at all. */
1358 	if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
1359 		goto skip_write;
1360 
1361 	diff = nr_pages_to_write(sbi, DATA, wbc);
1362 
1363 	if (!S_ISDIR(inode->i_mode)) {
1364 		mutex_lock(&sbi->writepages);
1365 		locked = true;
1366 	}
1367 	ret = f2fs_write_cache_pages(mapping, wbc, __f2fs_writepage, mapping);
1368 	f2fs_submit_merged_bio(sbi, DATA, WRITE);
1369 	if (locked)
1370 		mutex_unlock(&sbi->writepages);
1371 
1372 	remove_dirty_dir_inode(inode);
1373 
1374 	wbc->nr_to_write = max((long)0, wbc->nr_to_write - diff);
1375 	return ret;
1376 
1377 skip_write:
1378 	wbc->pages_skipped += get_dirty_pages(inode);
1379 	return 0;
1380 }
1381 
1382 static void f2fs_write_failed(struct address_space *mapping, loff_t to)
1383 {
1384 	struct inode *inode = mapping->host;
1385 
1386 	if (to > inode->i_size) {
1387 		truncate_pagecache(inode, inode->i_size);
1388 		truncate_blocks(inode, inode->i_size, true);
1389 	}
1390 }
1391 
1392 static int f2fs_write_begin(struct file *file, struct address_space *mapping,
1393 		loff_t pos, unsigned len, unsigned flags,
1394 		struct page **pagep, void **fsdata)
1395 {
1396 	struct inode *inode = mapping->host;
1397 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1398 	struct page *page = NULL;
1399 	struct page *ipage;
1400 	pgoff_t index = ((unsigned long long) pos) >> PAGE_CACHE_SHIFT;
1401 	struct dnode_of_data dn;
1402 	int err = 0;
1403 
1404 	trace_f2fs_write_begin(inode, pos, len, flags);
1405 
1406 	f2fs_balance_fs(sbi);
1407 
1408 	/*
1409 	 * We should check this at this moment to avoid deadlock on inode page
1410 	 * and #0 page. The locking rule for inline_data conversion should be:
1411 	 * lock_page(page #0) -> lock_page(inode_page)
1412 	 */
1413 	if (index != 0) {
1414 		err = f2fs_convert_inline_inode(inode);
1415 		if (err)
1416 			goto fail;
1417 	}
1418 repeat:
1419 	page = grab_cache_page_write_begin(mapping, index, flags);
1420 	if (!page) {
1421 		err = -ENOMEM;
1422 		goto fail;
1423 	}
1424 
1425 	*pagep = page;
1426 
1427 	f2fs_lock_op(sbi);
1428 
1429 	/* check inline_data */
1430 	ipage = get_node_page(sbi, inode->i_ino);
1431 	if (IS_ERR(ipage)) {
1432 		err = PTR_ERR(ipage);
1433 		goto unlock_fail;
1434 	}
1435 
1436 	set_new_dnode(&dn, inode, ipage, ipage, 0);
1437 
1438 	if (f2fs_has_inline_data(inode)) {
1439 		if (pos + len <= MAX_INLINE_DATA) {
1440 			read_inline_data(page, ipage);
1441 			set_inode_flag(F2FS_I(inode), FI_DATA_EXIST);
1442 			sync_inode_page(&dn);
1443 			goto put_next;
1444 		}
1445 		err = f2fs_convert_inline_page(&dn, page);
1446 		if (err)
1447 			goto put_fail;
1448 	}
1449 
1450 	err = f2fs_get_block(&dn, index);
1451 	if (err)
1452 		goto put_fail;
1453 put_next:
1454 	f2fs_put_dnode(&dn);
1455 	f2fs_unlock_op(sbi);
1456 
1457 	f2fs_wait_on_page_writeback(page, DATA);
1458 
1459 	/* wait for GCed encrypted page writeback */
1460 	if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode))
1461 		f2fs_wait_on_encrypted_page_writeback(sbi, dn.data_blkaddr);
1462 
1463 	if (len == PAGE_CACHE_SIZE)
1464 		goto out_update;
1465 	if (PageUptodate(page))
1466 		goto out_clear;
1467 
1468 	if ((pos & PAGE_CACHE_MASK) >= i_size_read(inode)) {
1469 		unsigned start = pos & (PAGE_CACHE_SIZE - 1);
1470 		unsigned end = start + len;
1471 
1472 		/* Reading beyond i_size is simple: memset to zero */
1473 		zero_user_segments(page, 0, start, end, PAGE_CACHE_SIZE);
1474 		goto out_update;
1475 	}
1476 
1477 	if (dn.data_blkaddr == NEW_ADDR) {
1478 		zero_user_segment(page, 0, PAGE_CACHE_SIZE);
1479 	} else {
1480 		struct f2fs_io_info fio = {
1481 			.sbi = sbi,
1482 			.type = DATA,
1483 			.rw = READ_SYNC,
1484 			.blk_addr = dn.data_blkaddr,
1485 			.page = page,
1486 			.encrypted_page = NULL,
1487 		};
1488 		err = f2fs_submit_page_bio(&fio);
1489 		if (err)
1490 			goto fail;
1491 
1492 		lock_page(page);
1493 		if (unlikely(!PageUptodate(page))) {
1494 			err = -EIO;
1495 			goto fail;
1496 		}
1497 		if (unlikely(page->mapping != mapping)) {
1498 			f2fs_put_page(page, 1);
1499 			goto repeat;
1500 		}
1501 
1502 		/* avoid symlink page */
1503 		if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode)) {
1504 			err = f2fs_decrypt_one(inode, page);
1505 			if (err)
1506 				goto fail;
1507 		}
1508 	}
1509 out_update:
1510 	SetPageUptodate(page);
1511 out_clear:
1512 	clear_cold_data(page);
1513 	return 0;
1514 
1515 put_fail:
1516 	f2fs_put_dnode(&dn);
1517 unlock_fail:
1518 	f2fs_unlock_op(sbi);
1519 fail:
1520 	f2fs_put_page(page, 1);
1521 	f2fs_write_failed(mapping, pos + len);
1522 	return err;
1523 }
1524 
1525 static int f2fs_write_end(struct file *file,
1526 			struct address_space *mapping,
1527 			loff_t pos, unsigned len, unsigned copied,
1528 			struct page *page, void *fsdata)
1529 {
1530 	struct inode *inode = page->mapping->host;
1531 
1532 	trace_f2fs_write_end(inode, pos, len, copied);
1533 
1534 	set_page_dirty(page);
1535 
1536 	if (pos + copied > i_size_read(inode)) {
1537 		i_size_write(inode, pos + copied);
1538 		mark_inode_dirty(inode);
1539 		update_inode_page(inode);
1540 	}
1541 
1542 	f2fs_put_page(page, 1);
1543 	return copied;
1544 }
1545 
1546 static int check_direct_IO(struct inode *inode, struct iov_iter *iter,
1547 			   loff_t offset)
1548 {
1549 	unsigned blocksize_mask = inode->i_sb->s_blocksize - 1;
1550 
1551 	if (offset & blocksize_mask)
1552 		return -EINVAL;
1553 
1554 	if (iov_iter_alignment(iter) & blocksize_mask)
1555 		return -EINVAL;
1556 
1557 	return 0;
1558 }
1559 
1560 static ssize_t f2fs_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
1561 			      loff_t offset)
1562 {
1563 	struct file *file = iocb->ki_filp;
1564 	struct address_space *mapping = file->f_mapping;
1565 	struct inode *inode = mapping->host;
1566 	size_t count = iov_iter_count(iter);
1567 	int err;
1568 
1569 	/* we don't need to use inline_data strictly */
1570 	if (f2fs_has_inline_data(inode)) {
1571 		err = f2fs_convert_inline_inode(inode);
1572 		if (err)
1573 			return err;
1574 	}
1575 
1576 	if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode))
1577 		return 0;
1578 
1579 	err = check_direct_IO(inode, iter, offset);
1580 	if (err)
1581 		return err;
1582 
1583 	trace_f2fs_direct_IO_enter(inode, offset, count, iov_iter_rw(iter));
1584 
1585 	if (iov_iter_rw(iter) == WRITE) {
1586 		__allocate_data_blocks(inode, offset, count);
1587 		if (unlikely(f2fs_cp_error(F2FS_I_SB(inode)))) {
1588 			err = -EIO;
1589 			goto out;
1590 		}
1591 	}
1592 
1593 	err = blockdev_direct_IO(iocb, inode, iter, offset, get_data_block_dio);
1594 out:
1595 	if (err < 0 && iov_iter_rw(iter) == WRITE)
1596 		f2fs_write_failed(mapping, offset + count);
1597 
1598 	trace_f2fs_direct_IO_exit(inode, offset, count, iov_iter_rw(iter), err);
1599 
1600 	return err;
1601 }
1602 
1603 void f2fs_invalidate_page(struct page *page, unsigned int offset,
1604 							unsigned int length)
1605 {
1606 	struct inode *inode = page->mapping->host;
1607 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1608 
1609 	if (inode->i_ino >= F2FS_ROOT_INO(sbi) &&
1610 		(offset % PAGE_CACHE_SIZE || length != PAGE_CACHE_SIZE))
1611 		return;
1612 
1613 	if (PageDirty(page)) {
1614 		if (inode->i_ino == F2FS_META_INO(sbi))
1615 			dec_page_count(sbi, F2FS_DIRTY_META);
1616 		else if (inode->i_ino == F2FS_NODE_INO(sbi))
1617 			dec_page_count(sbi, F2FS_DIRTY_NODES);
1618 		else
1619 			inode_dec_dirty_pages(inode);
1620 	}
1621 
1622 	/* This is atomic written page, keep Private */
1623 	if (IS_ATOMIC_WRITTEN_PAGE(page))
1624 		return;
1625 
1626 	ClearPagePrivate(page);
1627 }
1628 
1629 int f2fs_release_page(struct page *page, gfp_t wait)
1630 {
1631 	/* If this is dirty page, keep PagePrivate */
1632 	if (PageDirty(page))
1633 		return 0;
1634 
1635 	/* This is atomic written page, keep Private */
1636 	if (IS_ATOMIC_WRITTEN_PAGE(page))
1637 		return 0;
1638 
1639 	ClearPagePrivate(page);
1640 	return 1;
1641 }
1642 
1643 static int f2fs_set_data_page_dirty(struct page *page)
1644 {
1645 	struct address_space *mapping = page->mapping;
1646 	struct inode *inode = mapping->host;
1647 
1648 	trace_f2fs_set_page_dirty(page, DATA);
1649 
1650 	SetPageUptodate(page);
1651 
1652 	if (f2fs_is_atomic_file(inode)) {
1653 		if (!IS_ATOMIC_WRITTEN_PAGE(page)) {
1654 			register_inmem_page(inode, page);
1655 			return 1;
1656 		}
1657 		/*
1658 		 * Previously, this page has been registered, we just
1659 		 * return here.
1660 		 */
1661 		return 0;
1662 	}
1663 
1664 	if (!PageDirty(page)) {
1665 		__set_page_dirty_nobuffers(page);
1666 		update_dirty_page(inode, page);
1667 		return 1;
1668 	}
1669 	return 0;
1670 }
1671 
1672 static sector_t f2fs_bmap(struct address_space *mapping, sector_t block)
1673 {
1674 	struct inode *inode = mapping->host;
1675 
1676 	if (f2fs_has_inline_data(inode))
1677 		return 0;
1678 
1679 	/* make sure allocating whole blocks */
1680 	if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
1681 		filemap_write_and_wait(mapping);
1682 
1683 	return generic_block_bmap(mapping, block, get_data_block_bmap);
1684 }
1685 
1686 const struct address_space_operations f2fs_dblock_aops = {
1687 	.readpage	= f2fs_read_data_page,
1688 	.readpages	= f2fs_read_data_pages,
1689 	.writepage	= f2fs_write_data_page,
1690 	.writepages	= f2fs_write_data_pages,
1691 	.write_begin	= f2fs_write_begin,
1692 	.write_end	= f2fs_write_end,
1693 	.set_page_dirty	= f2fs_set_data_page_dirty,
1694 	.invalidatepage	= f2fs_invalidate_page,
1695 	.releasepage	= f2fs_release_page,
1696 	.direct_IO	= f2fs_direct_IO,
1697 	.bmap		= f2fs_bmap,
1698 };
1699