xref: /openbmc/linux/fs/f2fs/data.c (revision 1d373a0ef7a7bc08f95ca820c627e961fb21e188)
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 	mutex_lock(&inode->i_mutex);
775 
776 	if (len >= isize) {
777 		whole_file = true;
778 		len = isize;
779 	}
780 
781 	if (logical_to_blk(inode, len) == 0)
782 		len = blk_to_logical(inode, 1);
783 
784 	start_blk = logical_to_blk(inode, start);
785 	last_blk = logical_to_blk(inode, start + len - 1);
786 next:
787 	memset(&map_bh, 0, sizeof(struct buffer_head));
788 	map_bh.b_size = len;
789 
790 	ret = get_data_block(inode, start_blk, &map_bh, 0,
791 					F2FS_GET_BLOCK_FIEMAP);
792 	if (ret)
793 		goto out;
794 
795 	/* HOLE */
796 	if (!buffer_mapped(&map_bh)) {
797 		start_blk++;
798 
799 		if (!past_eof && blk_to_logical(inode, start_blk) >= isize)
800 			past_eof = 1;
801 
802 		if (past_eof && size) {
803 			flags |= FIEMAP_EXTENT_LAST;
804 			ret = fiemap_fill_next_extent(fieinfo, logical,
805 					phys, size, flags);
806 		} else if (size) {
807 			ret = fiemap_fill_next_extent(fieinfo, logical,
808 					phys, size, flags);
809 			size = 0;
810 		}
811 
812 		/* if we have holes up to/past EOF then we're done */
813 		if (start_blk > last_blk || past_eof || ret)
814 			goto out;
815 	} else {
816 		if (start_blk > last_blk && !whole_file) {
817 			ret = fiemap_fill_next_extent(fieinfo, logical,
818 					phys, size, flags);
819 			goto out;
820 		}
821 
822 		/*
823 		 * if size != 0 then we know we already have an extent
824 		 * to add, so add it.
825 		 */
826 		if (size) {
827 			ret = fiemap_fill_next_extent(fieinfo, logical,
828 					phys, size, flags);
829 			if (ret)
830 				goto out;
831 		}
832 
833 		logical = blk_to_logical(inode, start_blk);
834 		phys = blk_to_logical(inode, map_bh.b_blocknr);
835 		size = map_bh.b_size;
836 		flags = 0;
837 		if (buffer_unwritten(&map_bh))
838 			flags = FIEMAP_EXTENT_UNWRITTEN;
839 
840 		start_blk += logical_to_blk(inode, size);
841 
842 		/*
843 		 * If we are past the EOF, then we need to make sure as
844 		 * soon as we find a hole that the last extent we found
845 		 * is marked with FIEMAP_EXTENT_LAST
846 		 */
847 		if (!past_eof && logical + size >= isize)
848 			past_eof = true;
849 	}
850 	cond_resched();
851 	if (fatal_signal_pending(current))
852 		ret = -EINTR;
853 	else
854 		goto next;
855 out:
856 	if (ret == 1)
857 		ret = 0;
858 
859 	mutex_unlock(&inode->i_mutex);
860 	return ret;
861 }
862 
863 /*
864  * This function was originally taken from fs/mpage.c, and customized for f2fs.
865  * Major change was from block_size == page_size in f2fs by default.
866  */
867 static int f2fs_mpage_readpages(struct address_space *mapping,
868 			struct list_head *pages, struct page *page,
869 			unsigned nr_pages)
870 {
871 	struct bio *bio = NULL;
872 	unsigned page_idx;
873 	sector_t last_block_in_bio = 0;
874 	struct inode *inode = mapping->host;
875 	const unsigned blkbits = inode->i_blkbits;
876 	const unsigned blocksize = 1 << blkbits;
877 	sector_t block_in_file;
878 	sector_t last_block;
879 	sector_t last_block_in_file;
880 	sector_t block_nr;
881 	struct block_device *bdev = inode->i_sb->s_bdev;
882 	struct f2fs_map_blocks map;
883 
884 	map.m_pblk = 0;
885 	map.m_lblk = 0;
886 	map.m_len = 0;
887 	map.m_flags = 0;
888 
889 	for (page_idx = 0; nr_pages; page_idx++, nr_pages--) {
890 
891 		prefetchw(&page->flags);
892 		if (pages) {
893 			page = list_entry(pages->prev, struct page, lru);
894 			list_del(&page->lru);
895 			if (add_to_page_cache_lru(page, mapping,
896 						  page->index, GFP_KERNEL))
897 				goto next_page;
898 		}
899 
900 		block_in_file = (sector_t)page->index;
901 		last_block = block_in_file + nr_pages;
902 		last_block_in_file = (i_size_read(inode) + blocksize - 1) >>
903 								blkbits;
904 		if (last_block > last_block_in_file)
905 			last_block = last_block_in_file;
906 
907 		/*
908 		 * Map blocks using the previous result first.
909 		 */
910 		if ((map.m_flags & F2FS_MAP_MAPPED) &&
911 				block_in_file > map.m_lblk &&
912 				block_in_file < (map.m_lblk + map.m_len))
913 			goto got_it;
914 
915 		/*
916 		 * Then do more f2fs_map_blocks() calls until we are
917 		 * done with this page.
918 		 */
919 		map.m_flags = 0;
920 
921 		if (block_in_file < last_block) {
922 			map.m_lblk = block_in_file;
923 			map.m_len = last_block - block_in_file;
924 
925 			if (f2fs_map_blocks(inode, &map, 0,
926 							F2FS_GET_BLOCK_READ))
927 				goto set_error_page;
928 		}
929 got_it:
930 		if ((map.m_flags & F2FS_MAP_MAPPED)) {
931 			block_nr = map.m_pblk + block_in_file - map.m_lblk;
932 			SetPageMappedToDisk(page);
933 
934 			if (!PageUptodate(page) && !cleancache_get_page(page)) {
935 				SetPageUptodate(page);
936 				goto confused;
937 			}
938 		} else {
939 			zero_user_segment(page, 0, PAGE_CACHE_SIZE);
940 			SetPageUptodate(page);
941 			unlock_page(page);
942 			goto next_page;
943 		}
944 
945 		/*
946 		 * This page will go to BIO.  Do we need to send this
947 		 * BIO off first?
948 		 */
949 		if (bio && (last_block_in_bio != block_nr - 1)) {
950 submit_and_realloc:
951 			submit_bio(READ, bio);
952 			bio = NULL;
953 		}
954 		if (bio == NULL) {
955 			struct f2fs_crypto_ctx *ctx = NULL;
956 
957 			if (f2fs_encrypted_inode(inode) &&
958 					S_ISREG(inode->i_mode)) {
959 
960 				ctx = f2fs_get_crypto_ctx(inode);
961 				if (IS_ERR(ctx))
962 					goto set_error_page;
963 
964 				/* wait the page to be moved by cleaning */
965 				f2fs_wait_on_encrypted_page_writeback(
966 						F2FS_I_SB(inode), block_nr);
967 			}
968 
969 			bio = bio_alloc(GFP_KERNEL,
970 				min_t(int, nr_pages, BIO_MAX_PAGES));
971 			if (!bio) {
972 				if (ctx)
973 					f2fs_release_crypto_ctx(ctx);
974 				goto set_error_page;
975 			}
976 			bio->bi_bdev = bdev;
977 			bio->bi_iter.bi_sector = SECTOR_FROM_BLOCK(block_nr);
978 			bio->bi_end_io = f2fs_read_end_io;
979 			bio->bi_private = ctx;
980 		}
981 
982 		if (bio_add_page(bio, page, blocksize, 0) < blocksize)
983 			goto submit_and_realloc;
984 
985 		last_block_in_bio = block_nr;
986 		goto next_page;
987 set_error_page:
988 		SetPageError(page);
989 		zero_user_segment(page, 0, PAGE_CACHE_SIZE);
990 		unlock_page(page);
991 		goto next_page;
992 confused:
993 		if (bio) {
994 			submit_bio(READ, bio);
995 			bio = NULL;
996 		}
997 		unlock_page(page);
998 next_page:
999 		if (pages)
1000 			page_cache_release(page);
1001 	}
1002 	BUG_ON(pages && !list_empty(pages));
1003 	if (bio)
1004 		submit_bio(READ, bio);
1005 	return 0;
1006 }
1007 
1008 static int f2fs_read_data_page(struct file *file, struct page *page)
1009 {
1010 	struct inode *inode = page->mapping->host;
1011 	int ret = -EAGAIN;
1012 
1013 	trace_f2fs_readpage(page, DATA);
1014 
1015 	/* If the file has inline data, try to read it directly */
1016 	if (f2fs_has_inline_data(inode))
1017 		ret = f2fs_read_inline_data(inode, page);
1018 	if (ret == -EAGAIN)
1019 		ret = f2fs_mpage_readpages(page->mapping, NULL, page, 1);
1020 	return ret;
1021 }
1022 
1023 static int f2fs_read_data_pages(struct file *file,
1024 			struct address_space *mapping,
1025 			struct list_head *pages, unsigned nr_pages)
1026 {
1027 	struct inode *inode = file->f_mapping->host;
1028 	struct page *page = list_entry(pages->prev, struct page, lru);
1029 
1030 	trace_f2fs_readpages(inode, page, nr_pages);
1031 
1032 	/* If the file has inline data, skip readpages */
1033 	if (f2fs_has_inline_data(inode))
1034 		return 0;
1035 
1036 	return f2fs_mpage_readpages(mapping, pages, NULL, nr_pages);
1037 }
1038 
1039 int do_write_data_page(struct f2fs_io_info *fio)
1040 {
1041 	struct page *page = fio->page;
1042 	struct inode *inode = page->mapping->host;
1043 	struct dnode_of_data dn;
1044 	int err = 0;
1045 
1046 	set_new_dnode(&dn, inode, NULL, NULL, 0);
1047 	err = get_dnode_of_data(&dn, page->index, LOOKUP_NODE);
1048 	if (err)
1049 		return err;
1050 
1051 	fio->blk_addr = dn.data_blkaddr;
1052 
1053 	/* This page is already truncated */
1054 	if (fio->blk_addr == NULL_ADDR) {
1055 		ClearPageUptodate(page);
1056 		goto out_writepage;
1057 	}
1058 
1059 	if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode)) {
1060 
1061 		/* wait for GCed encrypted page writeback */
1062 		f2fs_wait_on_encrypted_page_writeback(F2FS_I_SB(inode),
1063 							fio->blk_addr);
1064 
1065 		fio->encrypted_page = f2fs_encrypt(inode, fio->page);
1066 		if (IS_ERR(fio->encrypted_page)) {
1067 			err = PTR_ERR(fio->encrypted_page);
1068 			goto out_writepage;
1069 		}
1070 	}
1071 
1072 	set_page_writeback(page);
1073 
1074 	/*
1075 	 * If current allocation needs SSR,
1076 	 * it had better in-place writes for updated data.
1077 	 */
1078 	if (unlikely(fio->blk_addr != NEW_ADDR &&
1079 			!is_cold_data(page) &&
1080 			need_inplace_update(inode))) {
1081 		rewrite_data_page(fio);
1082 		set_inode_flag(F2FS_I(inode), FI_UPDATE_WRITE);
1083 		trace_f2fs_do_write_data_page(page, IPU);
1084 	} else {
1085 		write_data_page(&dn, fio);
1086 		set_data_blkaddr(&dn);
1087 		f2fs_update_extent_cache(&dn);
1088 		trace_f2fs_do_write_data_page(page, OPU);
1089 		set_inode_flag(F2FS_I(inode), FI_APPEND_WRITE);
1090 		if (page->index == 0)
1091 			set_inode_flag(F2FS_I(inode), FI_FIRST_BLOCK_WRITTEN);
1092 	}
1093 out_writepage:
1094 	f2fs_put_dnode(&dn);
1095 	return err;
1096 }
1097 
1098 static int f2fs_write_data_page(struct page *page,
1099 					struct writeback_control *wbc)
1100 {
1101 	struct inode *inode = page->mapping->host;
1102 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1103 	loff_t i_size = i_size_read(inode);
1104 	const pgoff_t end_index = ((unsigned long long) i_size)
1105 							>> PAGE_CACHE_SHIFT;
1106 	unsigned offset = 0;
1107 	bool need_balance_fs = false;
1108 	int err = 0;
1109 	struct f2fs_io_info fio = {
1110 		.sbi = sbi,
1111 		.type = DATA,
1112 		.rw = (wbc->sync_mode == WB_SYNC_ALL) ? WRITE_SYNC : WRITE,
1113 		.page = page,
1114 		.encrypted_page = NULL,
1115 	};
1116 
1117 	trace_f2fs_writepage(page, DATA);
1118 
1119 	if (page->index < end_index)
1120 		goto write;
1121 
1122 	/*
1123 	 * If the offset is out-of-range of file size,
1124 	 * this page does not have to be written to disk.
1125 	 */
1126 	offset = i_size & (PAGE_CACHE_SIZE - 1);
1127 	if ((page->index >= end_index + 1) || !offset)
1128 		goto out;
1129 
1130 	zero_user_segment(page, offset, PAGE_CACHE_SIZE);
1131 write:
1132 	if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
1133 		goto redirty_out;
1134 	if (f2fs_is_drop_cache(inode))
1135 		goto out;
1136 	if (f2fs_is_volatile_file(inode) && !wbc->for_reclaim &&
1137 			available_free_memory(sbi, BASE_CHECK))
1138 		goto redirty_out;
1139 
1140 	/* Dentry blocks are controlled by checkpoint */
1141 	if (S_ISDIR(inode->i_mode)) {
1142 		if (unlikely(f2fs_cp_error(sbi)))
1143 			goto redirty_out;
1144 		err = do_write_data_page(&fio);
1145 		goto done;
1146 	}
1147 
1148 	/* we should bypass data pages to proceed the kworkder jobs */
1149 	if (unlikely(f2fs_cp_error(sbi))) {
1150 		SetPageError(page);
1151 		goto out;
1152 	}
1153 
1154 	if (!wbc->for_reclaim)
1155 		need_balance_fs = true;
1156 	else if (has_not_enough_free_secs(sbi, 0))
1157 		goto redirty_out;
1158 
1159 	err = -EAGAIN;
1160 	f2fs_lock_op(sbi);
1161 	if (f2fs_has_inline_data(inode))
1162 		err = f2fs_write_inline_data(inode, page);
1163 	if (err == -EAGAIN)
1164 		err = do_write_data_page(&fio);
1165 	f2fs_unlock_op(sbi);
1166 done:
1167 	if (err && err != -ENOENT)
1168 		goto redirty_out;
1169 
1170 	clear_cold_data(page);
1171 out:
1172 	inode_dec_dirty_pages(inode);
1173 	if (err)
1174 		ClearPageUptodate(page);
1175 	unlock_page(page);
1176 	if (need_balance_fs)
1177 		f2fs_balance_fs(sbi);
1178 	if (wbc->for_reclaim)
1179 		f2fs_submit_merged_bio(sbi, DATA, WRITE);
1180 	return 0;
1181 
1182 redirty_out:
1183 	redirty_page_for_writepage(wbc, page);
1184 	return AOP_WRITEPAGE_ACTIVATE;
1185 }
1186 
1187 static int __f2fs_writepage(struct page *page, struct writeback_control *wbc,
1188 			void *data)
1189 {
1190 	struct address_space *mapping = data;
1191 	int ret = mapping->a_ops->writepage(page, wbc);
1192 	mapping_set_error(mapping, ret);
1193 	return ret;
1194 }
1195 
1196 /*
1197  * This function was copied from write_cche_pages from mm/page-writeback.c.
1198  * The major change is making write step of cold data page separately from
1199  * warm/hot data page.
1200  */
1201 static int f2fs_write_cache_pages(struct address_space *mapping,
1202 			struct writeback_control *wbc, writepage_t writepage,
1203 			void *data)
1204 {
1205 	int ret = 0;
1206 	int done = 0;
1207 	struct pagevec pvec;
1208 	int nr_pages;
1209 	pgoff_t uninitialized_var(writeback_index);
1210 	pgoff_t index;
1211 	pgoff_t end;		/* Inclusive */
1212 	pgoff_t done_index;
1213 	int cycled;
1214 	int range_whole = 0;
1215 	int tag;
1216 	int step = 0;
1217 
1218 	pagevec_init(&pvec, 0);
1219 next:
1220 	if (wbc->range_cyclic) {
1221 		writeback_index = mapping->writeback_index; /* prev offset */
1222 		index = writeback_index;
1223 		if (index == 0)
1224 			cycled = 1;
1225 		else
1226 			cycled = 0;
1227 		end = -1;
1228 	} else {
1229 		index = wbc->range_start >> PAGE_CACHE_SHIFT;
1230 		end = wbc->range_end >> PAGE_CACHE_SHIFT;
1231 		if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
1232 			range_whole = 1;
1233 		cycled = 1; /* ignore range_cyclic tests */
1234 	}
1235 	if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
1236 		tag = PAGECACHE_TAG_TOWRITE;
1237 	else
1238 		tag = PAGECACHE_TAG_DIRTY;
1239 retry:
1240 	if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
1241 		tag_pages_for_writeback(mapping, index, end);
1242 	done_index = index;
1243 	while (!done && (index <= end)) {
1244 		int i;
1245 
1246 		nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
1247 			      min(end - index, (pgoff_t)PAGEVEC_SIZE - 1) + 1);
1248 		if (nr_pages == 0)
1249 			break;
1250 
1251 		for (i = 0; i < nr_pages; i++) {
1252 			struct page *page = pvec.pages[i];
1253 
1254 			if (page->index > end) {
1255 				done = 1;
1256 				break;
1257 			}
1258 
1259 			done_index = page->index;
1260 
1261 			lock_page(page);
1262 
1263 			if (unlikely(page->mapping != mapping)) {
1264 continue_unlock:
1265 				unlock_page(page);
1266 				continue;
1267 			}
1268 
1269 			if (!PageDirty(page)) {
1270 				/* someone wrote it for us */
1271 				goto continue_unlock;
1272 			}
1273 
1274 			if (step == is_cold_data(page))
1275 				goto continue_unlock;
1276 
1277 			if (PageWriteback(page)) {
1278 				if (wbc->sync_mode != WB_SYNC_NONE)
1279 					f2fs_wait_on_page_writeback(page, DATA);
1280 				else
1281 					goto continue_unlock;
1282 			}
1283 
1284 			BUG_ON(PageWriteback(page));
1285 			if (!clear_page_dirty_for_io(page))
1286 				goto continue_unlock;
1287 
1288 			ret = (*writepage)(page, wbc, data);
1289 			if (unlikely(ret)) {
1290 				if (ret == AOP_WRITEPAGE_ACTIVATE) {
1291 					unlock_page(page);
1292 					ret = 0;
1293 				} else {
1294 					done_index = page->index + 1;
1295 					done = 1;
1296 					break;
1297 				}
1298 			}
1299 
1300 			if (--wbc->nr_to_write <= 0 &&
1301 			    wbc->sync_mode == WB_SYNC_NONE) {
1302 				done = 1;
1303 				break;
1304 			}
1305 		}
1306 		pagevec_release(&pvec);
1307 		cond_resched();
1308 	}
1309 
1310 	if (step < 1) {
1311 		step++;
1312 		goto next;
1313 	}
1314 
1315 	if (!cycled && !done) {
1316 		cycled = 1;
1317 		index = 0;
1318 		end = writeback_index - 1;
1319 		goto retry;
1320 	}
1321 	if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
1322 		mapping->writeback_index = done_index;
1323 
1324 	return ret;
1325 }
1326 
1327 static int f2fs_write_data_pages(struct address_space *mapping,
1328 			    struct writeback_control *wbc)
1329 {
1330 	struct inode *inode = mapping->host;
1331 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1332 	bool locked = false;
1333 	int ret;
1334 	long diff;
1335 
1336 	trace_f2fs_writepages(mapping->host, wbc, DATA);
1337 
1338 	/* deal with chardevs and other special file */
1339 	if (!mapping->a_ops->writepage)
1340 		return 0;
1341 
1342 	/* skip writing if there is no dirty page in this inode */
1343 	if (!get_dirty_pages(inode) && wbc->sync_mode == WB_SYNC_NONE)
1344 		return 0;
1345 
1346 	if (S_ISDIR(inode->i_mode) && wbc->sync_mode == WB_SYNC_NONE &&
1347 			get_dirty_pages(inode) < nr_pages_to_skip(sbi, DATA) &&
1348 			available_free_memory(sbi, DIRTY_DENTS))
1349 		goto skip_write;
1350 
1351 	/* during POR, we don't need to trigger writepage at all. */
1352 	if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
1353 		goto skip_write;
1354 
1355 	diff = nr_pages_to_write(sbi, DATA, wbc);
1356 
1357 	if (!S_ISDIR(inode->i_mode)) {
1358 		mutex_lock(&sbi->writepages);
1359 		locked = true;
1360 	}
1361 	ret = f2fs_write_cache_pages(mapping, wbc, __f2fs_writepage, mapping);
1362 	f2fs_submit_merged_bio(sbi, DATA, WRITE);
1363 	if (locked)
1364 		mutex_unlock(&sbi->writepages);
1365 
1366 	remove_dirty_dir_inode(inode);
1367 
1368 	wbc->nr_to_write = max((long)0, wbc->nr_to_write - diff);
1369 	return ret;
1370 
1371 skip_write:
1372 	wbc->pages_skipped += get_dirty_pages(inode);
1373 	return 0;
1374 }
1375 
1376 static void f2fs_write_failed(struct address_space *mapping, loff_t to)
1377 {
1378 	struct inode *inode = mapping->host;
1379 
1380 	if (to > inode->i_size) {
1381 		truncate_pagecache(inode, inode->i_size);
1382 		truncate_blocks(inode, inode->i_size, true);
1383 	}
1384 }
1385 
1386 static int f2fs_write_begin(struct file *file, struct address_space *mapping,
1387 		loff_t pos, unsigned len, unsigned flags,
1388 		struct page **pagep, void **fsdata)
1389 {
1390 	struct inode *inode = mapping->host;
1391 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1392 	struct page *page = NULL;
1393 	struct page *ipage;
1394 	pgoff_t index = ((unsigned long long) pos) >> PAGE_CACHE_SHIFT;
1395 	struct dnode_of_data dn;
1396 	int err = 0;
1397 
1398 	trace_f2fs_write_begin(inode, pos, len, flags);
1399 
1400 	f2fs_balance_fs(sbi);
1401 
1402 	/*
1403 	 * We should check this at this moment to avoid deadlock on inode page
1404 	 * and #0 page. The locking rule for inline_data conversion should be:
1405 	 * lock_page(page #0) -> lock_page(inode_page)
1406 	 */
1407 	if (index != 0) {
1408 		err = f2fs_convert_inline_inode(inode);
1409 		if (err)
1410 			goto fail;
1411 	}
1412 repeat:
1413 	page = grab_cache_page_write_begin(mapping, index, flags);
1414 	if (!page) {
1415 		err = -ENOMEM;
1416 		goto fail;
1417 	}
1418 
1419 	*pagep = page;
1420 
1421 	f2fs_lock_op(sbi);
1422 
1423 	/* check inline_data */
1424 	ipage = get_node_page(sbi, inode->i_ino);
1425 	if (IS_ERR(ipage)) {
1426 		err = PTR_ERR(ipage);
1427 		goto unlock_fail;
1428 	}
1429 
1430 	set_new_dnode(&dn, inode, ipage, ipage, 0);
1431 
1432 	if (f2fs_has_inline_data(inode)) {
1433 		if (pos + len <= MAX_INLINE_DATA) {
1434 			read_inline_data(page, ipage);
1435 			set_inode_flag(F2FS_I(inode), FI_DATA_EXIST);
1436 			sync_inode_page(&dn);
1437 			goto put_next;
1438 		}
1439 		err = f2fs_convert_inline_page(&dn, page);
1440 		if (err)
1441 			goto put_fail;
1442 	}
1443 
1444 	err = f2fs_get_block(&dn, index);
1445 	if (err)
1446 		goto put_fail;
1447 put_next:
1448 	f2fs_put_dnode(&dn);
1449 	f2fs_unlock_op(sbi);
1450 
1451 	f2fs_wait_on_page_writeback(page, DATA);
1452 
1453 	/* wait for GCed encrypted page writeback */
1454 	if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode))
1455 		f2fs_wait_on_encrypted_page_writeback(sbi, dn.data_blkaddr);
1456 
1457 	if (len == PAGE_CACHE_SIZE)
1458 		goto out_update;
1459 	if (PageUptodate(page))
1460 		goto out_clear;
1461 
1462 	if ((pos & PAGE_CACHE_MASK) >= i_size_read(inode)) {
1463 		unsigned start = pos & (PAGE_CACHE_SIZE - 1);
1464 		unsigned end = start + len;
1465 
1466 		/* Reading beyond i_size is simple: memset to zero */
1467 		zero_user_segments(page, 0, start, end, PAGE_CACHE_SIZE);
1468 		goto out_update;
1469 	}
1470 
1471 	if (dn.data_blkaddr == NEW_ADDR) {
1472 		zero_user_segment(page, 0, PAGE_CACHE_SIZE);
1473 	} else {
1474 		struct f2fs_io_info fio = {
1475 			.sbi = sbi,
1476 			.type = DATA,
1477 			.rw = READ_SYNC,
1478 			.blk_addr = dn.data_blkaddr,
1479 			.page = page,
1480 			.encrypted_page = NULL,
1481 		};
1482 		err = f2fs_submit_page_bio(&fio);
1483 		if (err)
1484 			goto fail;
1485 
1486 		lock_page(page);
1487 		if (unlikely(!PageUptodate(page))) {
1488 			err = -EIO;
1489 			goto fail;
1490 		}
1491 		if (unlikely(page->mapping != mapping)) {
1492 			f2fs_put_page(page, 1);
1493 			goto repeat;
1494 		}
1495 
1496 		/* avoid symlink page */
1497 		if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode)) {
1498 			err = f2fs_decrypt_one(inode, page);
1499 			if (err)
1500 				goto fail;
1501 		}
1502 	}
1503 out_update:
1504 	SetPageUptodate(page);
1505 out_clear:
1506 	clear_cold_data(page);
1507 	return 0;
1508 
1509 put_fail:
1510 	f2fs_put_dnode(&dn);
1511 unlock_fail:
1512 	f2fs_unlock_op(sbi);
1513 fail:
1514 	f2fs_put_page(page, 1);
1515 	f2fs_write_failed(mapping, pos + len);
1516 	return err;
1517 }
1518 
1519 static int f2fs_write_end(struct file *file,
1520 			struct address_space *mapping,
1521 			loff_t pos, unsigned len, unsigned copied,
1522 			struct page *page, void *fsdata)
1523 {
1524 	struct inode *inode = page->mapping->host;
1525 
1526 	trace_f2fs_write_end(inode, pos, len, copied);
1527 
1528 	set_page_dirty(page);
1529 
1530 	if (pos + copied > i_size_read(inode)) {
1531 		i_size_write(inode, pos + copied);
1532 		mark_inode_dirty(inode);
1533 		update_inode_page(inode);
1534 	}
1535 
1536 	f2fs_put_page(page, 1);
1537 	return copied;
1538 }
1539 
1540 static int check_direct_IO(struct inode *inode, struct iov_iter *iter,
1541 			   loff_t offset)
1542 {
1543 	unsigned blocksize_mask = inode->i_sb->s_blocksize - 1;
1544 
1545 	if (offset & blocksize_mask)
1546 		return -EINVAL;
1547 
1548 	if (iov_iter_alignment(iter) & blocksize_mask)
1549 		return -EINVAL;
1550 
1551 	return 0;
1552 }
1553 
1554 static ssize_t f2fs_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
1555 			      loff_t offset)
1556 {
1557 	struct file *file = iocb->ki_filp;
1558 	struct address_space *mapping = file->f_mapping;
1559 	struct inode *inode = mapping->host;
1560 	size_t count = iov_iter_count(iter);
1561 	int err;
1562 
1563 	/* we don't need to use inline_data strictly */
1564 	if (f2fs_has_inline_data(inode)) {
1565 		err = f2fs_convert_inline_inode(inode);
1566 		if (err)
1567 			return err;
1568 	}
1569 
1570 	if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode))
1571 		return 0;
1572 
1573 	err = check_direct_IO(inode, iter, offset);
1574 	if (err)
1575 		return err;
1576 
1577 	trace_f2fs_direct_IO_enter(inode, offset, count, iov_iter_rw(iter));
1578 
1579 	if (iov_iter_rw(iter) == WRITE) {
1580 		__allocate_data_blocks(inode, offset, count);
1581 		if (unlikely(f2fs_cp_error(F2FS_I_SB(inode)))) {
1582 			err = -EIO;
1583 			goto out;
1584 		}
1585 	}
1586 
1587 	err = blockdev_direct_IO(iocb, inode, iter, offset, get_data_block_dio);
1588 out:
1589 	if (err < 0 && iov_iter_rw(iter) == WRITE)
1590 		f2fs_write_failed(mapping, offset + count);
1591 
1592 	trace_f2fs_direct_IO_exit(inode, offset, count, iov_iter_rw(iter), err);
1593 
1594 	return err;
1595 }
1596 
1597 void f2fs_invalidate_page(struct page *page, unsigned int offset,
1598 							unsigned int length)
1599 {
1600 	struct inode *inode = page->mapping->host;
1601 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1602 
1603 	if (inode->i_ino >= F2FS_ROOT_INO(sbi) &&
1604 		(offset % PAGE_CACHE_SIZE || length != PAGE_CACHE_SIZE))
1605 		return;
1606 
1607 	if (PageDirty(page)) {
1608 		if (inode->i_ino == F2FS_META_INO(sbi))
1609 			dec_page_count(sbi, F2FS_DIRTY_META);
1610 		else if (inode->i_ino == F2FS_NODE_INO(sbi))
1611 			dec_page_count(sbi, F2FS_DIRTY_NODES);
1612 		else
1613 			inode_dec_dirty_pages(inode);
1614 	}
1615 
1616 	/* This is atomic written page, keep Private */
1617 	if (IS_ATOMIC_WRITTEN_PAGE(page))
1618 		return;
1619 
1620 	ClearPagePrivate(page);
1621 }
1622 
1623 int f2fs_release_page(struct page *page, gfp_t wait)
1624 {
1625 	/* If this is dirty page, keep PagePrivate */
1626 	if (PageDirty(page))
1627 		return 0;
1628 
1629 	/* This is atomic written page, keep Private */
1630 	if (IS_ATOMIC_WRITTEN_PAGE(page))
1631 		return 0;
1632 
1633 	ClearPagePrivate(page);
1634 	return 1;
1635 }
1636 
1637 static int f2fs_set_data_page_dirty(struct page *page)
1638 {
1639 	struct address_space *mapping = page->mapping;
1640 	struct inode *inode = mapping->host;
1641 
1642 	trace_f2fs_set_page_dirty(page, DATA);
1643 
1644 	SetPageUptodate(page);
1645 
1646 	if (f2fs_is_atomic_file(inode)) {
1647 		if (!IS_ATOMIC_WRITTEN_PAGE(page)) {
1648 			register_inmem_page(inode, page);
1649 			return 1;
1650 		}
1651 		/*
1652 		 * Previously, this page has been registered, we just
1653 		 * return here.
1654 		 */
1655 		return 0;
1656 	}
1657 
1658 	if (!PageDirty(page)) {
1659 		__set_page_dirty_nobuffers(page);
1660 		update_dirty_page(inode, page);
1661 		return 1;
1662 	}
1663 	return 0;
1664 }
1665 
1666 static sector_t f2fs_bmap(struct address_space *mapping, sector_t block)
1667 {
1668 	struct inode *inode = mapping->host;
1669 
1670 	if (f2fs_has_inline_data(inode))
1671 		return 0;
1672 
1673 	/* make sure allocating whole blocks */
1674 	if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
1675 		filemap_write_and_wait(mapping);
1676 
1677 	return generic_block_bmap(mapping, block, get_data_block_bmap);
1678 }
1679 
1680 const struct address_space_operations f2fs_dblock_aops = {
1681 	.readpage	= f2fs_read_data_page,
1682 	.readpages	= f2fs_read_data_pages,
1683 	.writepage	= f2fs_write_data_page,
1684 	.writepages	= f2fs_write_data_pages,
1685 	.write_begin	= f2fs_write_begin,
1686 	.write_end	= f2fs_write_end,
1687 	.set_page_dirty	= f2fs_set_data_page_dirty,
1688 	.invalidatepage	= f2fs_invalidate_page,
1689 	.releasepage	= f2fs_release_page,
1690 	.direct_IO	= f2fs_direct_IO,
1691 	.bmap		= f2fs_bmap,
1692 };
1693