xref: /linux/fs/f2fs/data.c (revision 4cf421e55d69016989548e0fb8585e69f54bd283)
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/mm.h>
23 #include <linux/memcontrol.h>
24 #include <linux/cleancache.h>
25 
26 #include "f2fs.h"
27 #include "node.h"
28 #include "segment.h"
29 #include "trace.h"
30 #include <trace/events/f2fs.h>
31 
32 static bool __is_cp_guaranteed(struct page *page)
33 {
34 	struct address_space *mapping = page->mapping;
35 	struct inode *inode;
36 	struct f2fs_sb_info *sbi;
37 
38 	if (!mapping)
39 		return false;
40 
41 	inode = mapping->host;
42 	sbi = F2FS_I_SB(inode);
43 
44 	if (inode->i_ino == F2FS_META_INO(sbi) ||
45 			inode->i_ino ==  F2FS_NODE_INO(sbi) ||
46 			S_ISDIR(inode->i_mode) ||
47 			is_cold_data(page))
48 		return true;
49 	return false;
50 }
51 
52 static void f2fs_read_end_io(struct bio *bio)
53 {
54 	struct bio_vec *bvec;
55 	int i;
56 
57 #ifdef CONFIG_F2FS_FAULT_INJECTION
58 	if (time_to_inject(F2FS_P_SB(bio->bi_io_vec->bv_page), FAULT_IO)) {
59 		f2fs_show_injection_info(FAULT_IO);
60 		bio->bi_error = -EIO;
61 	}
62 #endif
63 
64 	if (f2fs_bio_encrypted(bio)) {
65 		if (bio->bi_error) {
66 			fscrypt_release_ctx(bio->bi_private);
67 		} else {
68 			fscrypt_decrypt_bio_pages(bio->bi_private, bio);
69 			return;
70 		}
71 	}
72 
73 	bio_for_each_segment_all(bvec, bio, i) {
74 		struct page *page = bvec->bv_page;
75 
76 		if (!bio->bi_error) {
77 			if (!PageUptodate(page))
78 				SetPageUptodate(page);
79 		} else {
80 			ClearPageUptodate(page);
81 			SetPageError(page);
82 		}
83 		unlock_page(page);
84 	}
85 	bio_put(bio);
86 }
87 
88 static void f2fs_write_end_io(struct bio *bio)
89 {
90 	struct f2fs_sb_info *sbi = bio->bi_private;
91 	struct bio_vec *bvec;
92 	int i;
93 
94 	bio_for_each_segment_all(bvec, bio, i) {
95 		struct page *page = bvec->bv_page;
96 		enum count_type type = WB_DATA_TYPE(page);
97 
98 		if (IS_DUMMY_WRITTEN_PAGE(page)) {
99 			set_page_private(page, (unsigned long)NULL);
100 			ClearPagePrivate(page);
101 			unlock_page(page);
102 			mempool_free(page, sbi->write_io_dummy);
103 
104 			if (unlikely(bio->bi_error))
105 				f2fs_stop_checkpoint(sbi, true);
106 			continue;
107 		}
108 
109 		fscrypt_pullback_bio_page(&page, true);
110 
111 		if (unlikely(bio->bi_error)) {
112 			mapping_set_error(page->mapping, -EIO);
113 			f2fs_stop_checkpoint(sbi, true);
114 		}
115 		dec_page_count(sbi, type);
116 		clear_cold_data(page);
117 		end_page_writeback(page);
118 	}
119 	if (!get_pages(sbi, F2FS_WB_CP_DATA) &&
120 				wq_has_sleeper(&sbi->cp_wait))
121 		wake_up(&sbi->cp_wait);
122 
123 	bio_put(bio);
124 }
125 
126 /*
127  * Return true, if pre_bio's bdev is same as its target device.
128  */
129 struct block_device *f2fs_target_device(struct f2fs_sb_info *sbi,
130 				block_t blk_addr, struct bio *bio)
131 {
132 	struct block_device *bdev = sbi->sb->s_bdev;
133 	int i;
134 
135 	for (i = 0; i < sbi->s_ndevs; i++) {
136 		if (FDEV(i).start_blk <= blk_addr &&
137 					FDEV(i).end_blk >= blk_addr) {
138 			blk_addr -= FDEV(i).start_blk;
139 			bdev = FDEV(i).bdev;
140 			break;
141 		}
142 	}
143 	if (bio) {
144 		bio->bi_bdev = bdev;
145 		bio->bi_iter.bi_sector = SECTOR_FROM_BLOCK(blk_addr);
146 	}
147 	return bdev;
148 }
149 
150 int f2fs_target_device_index(struct f2fs_sb_info *sbi, block_t blkaddr)
151 {
152 	int i;
153 
154 	for (i = 0; i < sbi->s_ndevs; i++)
155 		if (FDEV(i).start_blk <= blkaddr && FDEV(i).end_blk >= blkaddr)
156 			return i;
157 	return 0;
158 }
159 
160 static bool __same_bdev(struct f2fs_sb_info *sbi,
161 				block_t blk_addr, struct bio *bio)
162 {
163 	return f2fs_target_device(sbi, blk_addr, NULL) == bio->bi_bdev;
164 }
165 
166 /*
167  * Low-level block read/write IO operations.
168  */
169 static struct bio *__bio_alloc(struct f2fs_sb_info *sbi, block_t blk_addr,
170 				int npages, bool is_read)
171 {
172 	struct bio *bio;
173 
174 	bio = f2fs_bio_alloc(npages);
175 
176 	f2fs_target_device(sbi, blk_addr, bio);
177 	bio->bi_end_io = is_read ? f2fs_read_end_io : f2fs_write_end_io;
178 	bio->bi_private = is_read ? NULL : sbi;
179 
180 	return bio;
181 }
182 
183 static inline void __submit_bio(struct f2fs_sb_info *sbi,
184 				struct bio *bio, enum page_type type)
185 {
186 	if (!is_read_io(bio_op(bio))) {
187 		unsigned int start;
188 
189 		if (f2fs_sb_mounted_blkzoned(sbi->sb) &&
190 			current->plug && (type == DATA || type == NODE))
191 			blk_finish_plug(current->plug);
192 
193 		if (type != DATA && type != NODE)
194 			goto submit_io;
195 
196 		start = bio->bi_iter.bi_size >> F2FS_BLKSIZE_BITS;
197 		start %= F2FS_IO_SIZE(sbi);
198 
199 		if (start == 0)
200 			goto submit_io;
201 
202 		/* fill dummy pages */
203 		for (; start < F2FS_IO_SIZE(sbi); start++) {
204 			struct page *page =
205 				mempool_alloc(sbi->write_io_dummy,
206 					GFP_NOIO | __GFP_ZERO | __GFP_NOFAIL);
207 			f2fs_bug_on(sbi, !page);
208 
209 			SetPagePrivate(page);
210 			set_page_private(page, (unsigned long)DUMMY_WRITTEN_PAGE);
211 			lock_page(page);
212 			if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE)
213 				f2fs_bug_on(sbi, 1);
214 		}
215 		/*
216 		 * In the NODE case, we lose next block address chain. So, we
217 		 * need to do checkpoint in f2fs_sync_file.
218 		 */
219 		if (type == NODE)
220 			set_sbi_flag(sbi, SBI_NEED_CP);
221 	}
222 submit_io:
223 	if (is_read_io(bio_op(bio)))
224 		trace_f2fs_submit_read_bio(sbi->sb, type, bio);
225 	else
226 		trace_f2fs_submit_write_bio(sbi->sb, type, bio);
227 	submit_bio(bio);
228 }
229 
230 static void __submit_merged_bio(struct f2fs_bio_info *io)
231 {
232 	struct f2fs_io_info *fio = &io->fio;
233 
234 	if (!io->bio)
235 		return;
236 
237 	bio_set_op_attrs(io->bio, fio->op, fio->op_flags);
238 
239 	if (is_read_io(fio->op))
240 		trace_f2fs_prepare_read_bio(io->sbi->sb, fio->type, io->bio);
241 	else
242 		trace_f2fs_prepare_write_bio(io->sbi->sb, fio->type, io->bio);
243 
244 	__submit_bio(io->sbi, io->bio, fio->type);
245 	io->bio = NULL;
246 }
247 
248 static bool __has_merged_page(struct f2fs_bio_info *io,
249 				struct inode *inode, nid_t ino, pgoff_t idx)
250 {
251 	struct bio_vec *bvec;
252 	struct page *target;
253 	int i;
254 
255 	if (!io->bio)
256 		return false;
257 
258 	if (!inode && !ino)
259 		return true;
260 
261 	bio_for_each_segment_all(bvec, io->bio, i) {
262 
263 		if (bvec->bv_page->mapping)
264 			target = bvec->bv_page;
265 		else
266 			target = fscrypt_control_page(bvec->bv_page);
267 
268 		if (idx != target->index)
269 			continue;
270 
271 		if (inode && inode == target->mapping->host)
272 			return true;
273 		if (ino && ino == ino_of_node(target))
274 			return true;
275 	}
276 
277 	return false;
278 }
279 
280 static bool has_merged_page(struct f2fs_sb_info *sbi, struct inode *inode,
281 				nid_t ino, pgoff_t idx, enum page_type type)
282 {
283 	enum page_type btype = PAGE_TYPE_OF_BIO(type);
284 	struct f2fs_bio_info *io = &sbi->write_io[btype];
285 	bool ret;
286 
287 	down_read(&io->io_rwsem);
288 	ret = __has_merged_page(io, inode, ino, idx);
289 	up_read(&io->io_rwsem);
290 	return ret;
291 }
292 
293 static void __f2fs_submit_merged_bio(struct f2fs_sb_info *sbi,
294 				struct inode *inode, nid_t ino, pgoff_t idx,
295 				enum page_type type, int rw)
296 {
297 	enum page_type btype = PAGE_TYPE_OF_BIO(type);
298 	struct f2fs_bio_info *io;
299 
300 	io = is_read_io(rw) ? &sbi->read_io : &sbi->write_io[btype];
301 
302 	down_write(&io->io_rwsem);
303 
304 	if (!__has_merged_page(io, inode, ino, idx))
305 		goto out;
306 
307 	/* change META to META_FLUSH in the checkpoint procedure */
308 	if (type >= META_FLUSH) {
309 		io->fio.type = META_FLUSH;
310 		io->fio.op = REQ_OP_WRITE;
311 		io->fio.op_flags = REQ_META | REQ_PRIO;
312 		if (!test_opt(sbi, NOBARRIER))
313 			io->fio.op_flags |= REQ_PREFLUSH | REQ_FUA;
314 	}
315 	__submit_merged_bio(io);
316 out:
317 	up_write(&io->io_rwsem);
318 }
319 
320 void f2fs_submit_merged_bio(struct f2fs_sb_info *sbi, enum page_type type,
321 									int rw)
322 {
323 	__f2fs_submit_merged_bio(sbi, NULL, 0, 0, type, rw);
324 }
325 
326 void f2fs_submit_merged_bio_cond(struct f2fs_sb_info *sbi,
327 				struct inode *inode, nid_t ino, pgoff_t idx,
328 				enum page_type type, int rw)
329 {
330 	if (has_merged_page(sbi, inode, ino, idx, type))
331 		__f2fs_submit_merged_bio(sbi, inode, ino, idx, type, rw);
332 }
333 
334 void f2fs_flush_merged_bios(struct f2fs_sb_info *sbi)
335 {
336 	f2fs_submit_merged_bio(sbi, DATA, WRITE);
337 	f2fs_submit_merged_bio(sbi, NODE, WRITE);
338 	f2fs_submit_merged_bio(sbi, META, WRITE);
339 }
340 
341 /*
342  * Fill the locked page with data located in the block address.
343  * Return unlocked page.
344  */
345 int f2fs_submit_page_bio(struct f2fs_io_info *fio)
346 {
347 	struct bio *bio;
348 	struct page *page = fio->encrypted_page ?
349 			fio->encrypted_page : fio->page;
350 
351 	trace_f2fs_submit_page_bio(page, fio);
352 	f2fs_trace_ios(fio, 0);
353 
354 	/* Allocate a new bio */
355 	bio = __bio_alloc(fio->sbi, fio->new_blkaddr, 1, is_read_io(fio->op));
356 
357 	if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
358 		bio_put(bio);
359 		return -EFAULT;
360 	}
361 	bio_set_op_attrs(bio, fio->op, fio->op_flags);
362 
363 	__submit_bio(fio->sbi, bio, fio->type);
364 	return 0;
365 }
366 
367 int f2fs_submit_page_mbio(struct f2fs_io_info *fio)
368 {
369 	struct f2fs_sb_info *sbi = fio->sbi;
370 	enum page_type btype = PAGE_TYPE_OF_BIO(fio->type);
371 	struct f2fs_bio_info *io;
372 	bool is_read = is_read_io(fio->op);
373 	struct page *bio_page;
374 	int err = 0;
375 
376 	io = is_read ? &sbi->read_io : &sbi->write_io[btype];
377 
378 	if (fio->old_blkaddr != NEW_ADDR)
379 		verify_block_addr(sbi, fio->old_blkaddr);
380 	verify_block_addr(sbi, fio->new_blkaddr);
381 
382 	bio_page = fio->encrypted_page ? fio->encrypted_page : fio->page;
383 
384 	/* set submitted = 1 as a return value */
385 	fio->submitted = 1;
386 
387 	if (!is_read)
388 		inc_page_count(sbi, WB_DATA_TYPE(bio_page));
389 
390 	down_write(&io->io_rwsem);
391 
392 	if (io->bio && (io->last_block_in_bio != fio->new_blkaddr - 1 ||
393 	    (io->fio.op != fio->op || io->fio.op_flags != fio->op_flags) ||
394 			!__same_bdev(sbi, fio->new_blkaddr, io->bio)))
395 		__submit_merged_bio(io);
396 alloc_new:
397 	if (io->bio == NULL) {
398 		if ((fio->type == DATA || fio->type == NODE) &&
399 				fio->new_blkaddr & F2FS_IO_SIZE_MASK(sbi)) {
400 			err = -EAGAIN;
401 			if (!is_read)
402 				dec_page_count(sbi, WB_DATA_TYPE(bio_page));
403 			goto out_fail;
404 		}
405 		io->bio = __bio_alloc(sbi, fio->new_blkaddr,
406 						BIO_MAX_PAGES, is_read);
407 		io->fio = *fio;
408 	}
409 
410 	if (bio_add_page(io->bio, bio_page, PAGE_SIZE, 0) <
411 							PAGE_SIZE) {
412 		__submit_merged_bio(io);
413 		goto alloc_new;
414 	}
415 
416 	io->last_block_in_bio = fio->new_blkaddr;
417 	f2fs_trace_ios(fio, 0);
418 out_fail:
419 	up_write(&io->io_rwsem);
420 	trace_f2fs_submit_page_mbio(fio->page, fio);
421 	return err;
422 }
423 
424 static void __set_data_blkaddr(struct dnode_of_data *dn)
425 {
426 	struct f2fs_node *rn = F2FS_NODE(dn->node_page);
427 	__le32 *addr_array;
428 
429 	/* Get physical address of data block */
430 	addr_array = blkaddr_in_node(rn);
431 	addr_array[dn->ofs_in_node] = cpu_to_le32(dn->data_blkaddr);
432 }
433 
434 /*
435  * Lock ordering for the change of data block address:
436  * ->data_page
437  *  ->node_page
438  *    update block addresses in the node page
439  */
440 void set_data_blkaddr(struct dnode_of_data *dn)
441 {
442 	f2fs_wait_on_page_writeback(dn->node_page, NODE, true);
443 	__set_data_blkaddr(dn);
444 	if (set_page_dirty(dn->node_page))
445 		dn->node_changed = true;
446 }
447 
448 void f2fs_update_data_blkaddr(struct dnode_of_data *dn, block_t blkaddr)
449 {
450 	dn->data_blkaddr = blkaddr;
451 	set_data_blkaddr(dn);
452 	f2fs_update_extent_cache(dn);
453 }
454 
455 /* dn->ofs_in_node will be returned with up-to-date last block pointer */
456 int reserve_new_blocks(struct dnode_of_data *dn, blkcnt_t count)
457 {
458 	struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
459 
460 	if (!count)
461 		return 0;
462 
463 	if (unlikely(is_inode_flag_set(dn->inode, FI_NO_ALLOC)))
464 		return -EPERM;
465 	if (unlikely(!inc_valid_block_count(sbi, dn->inode, &count)))
466 		return -ENOSPC;
467 
468 	trace_f2fs_reserve_new_blocks(dn->inode, dn->nid,
469 						dn->ofs_in_node, count);
470 
471 	f2fs_wait_on_page_writeback(dn->node_page, NODE, true);
472 
473 	for (; count > 0; dn->ofs_in_node++) {
474 		block_t blkaddr =
475 			datablock_addr(dn->node_page, dn->ofs_in_node);
476 		if (blkaddr == NULL_ADDR) {
477 			dn->data_blkaddr = NEW_ADDR;
478 			__set_data_blkaddr(dn);
479 			count--;
480 		}
481 	}
482 
483 	if (set_page_dirty(dn->node_page))
484 		dn->node_changed = true;
485 	return 0;
486 }
487 
488 /* Should keep dn->ofs_in_node unchanged */
489 int reserve_new_block(struct dnode_of_data *dn)
490 {
491 	unsigned int ofs_in_node = dn->ofs_in_node;
492 	int ret;
493 
494 	ret = reserve_new_blocks(dn, 1);
495 	dn->ofs_in_node = ofs_in_node;
496 	return ret;
497 }
498 
499 int f2fs_reserve_block(struct dnode_of_data *dn, pgoff_t index)
500 {
501 	bool need_put = dn->inode_page ? false : true;
502 	int err;
503 
504 	err = get_dnode_of_data(dn, index, ALLOC_NODE);
505 	if (err)
506 		return err;
507 
508 	if (dn->data_blkaddr == NULL_ADDR)
509 		err = reserve_new_block(dn);
510 	if (err || need_put)
511 		f2fs_put_dnode(dn);
512 	return err;
513 }
514 
515 int f2fs_get_block(struct dnode_of_data *dn, pgoff_t index)
516 {
517 	struct extent_info ei  = {0,0,0};
518 	struct inode *inode = dn->inode;
519 
520 	if (f2fs_lookup_extent_cache(inode, index, &ei)) {
521 		dn->data_blkaddr = ei.blk + index - ei.fofs;
522 		return 0;
523 	}
524 
525 	return f2fs_reserve_block(dn, index);
526 }
527 
528 struct page *get_read_data_page(struct inode *inode, pgoff_t index,
529 						int op_flags, bool for_write)
530 {
531 	struct address_space *mapping = inode->i_mapping;
532 	struct dnode_of_data dn;
533 	struct page *page;
534 	struct extent_info ei = {0,0,0};
535 	int err;
536 	struct f2fs_io_info fio = {
537 		.sbi = F2FS_I_SB(inode),
538 		.type = DATA,
539 		.op = REQ_OP_READ,
540 		.op_flags = op_flags,
541 		.encrypted_page = NULL,
542 	};
543 
544 	if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode))
545 		return read_mapping_page(mapping, index, NULL);
546 
547 	page = f2fs_grab_cache_page(mapping, index, for_write);
548 	if (!page)
549 		return ERR_PTR(-ENOMEM);
550 
551 	if (f2fs_lookup_extent_cache(inode, index, &ei)) {
552 		dn.data_blkaddr = ei.blk + index - ei.fofs;
553 		goto got_it;
554 	}
555 
556 	set_new_dnode(&dn, inode, NULL, NULL, 0);
557 	err = get_dnode_of_data(&dn, index, LOOKUP_NODE);
558 	if (err)
559 		goto put_err;
560 	f2fs_put_dnode(&dn);
561 
562 	if (unlikely(dn.data_blkaddr == NULL_ADDR)) {
563 		err = -ENOENT;
564 		goto put_err;
565 	}
566 got_it:
567 	if (PageUptodate(page)) {
568 		unlock_page(page);
569 		return page;
570 	}
571 
572 	/*
573 	 * A new dentry page is allocated but not able to be written, since its
574 	 * new inode page couldn't be allocated due to -ENOSPC.
575 	 * In such the case, its blkaddr can be remained as NEW_ADDR.
576 	 * see, f2fs_add_link -> get_new_data_page -> init_inode_metadata.
577 	 */
578 	if (dn.data_blkaddr == NEW_ADDR) {
579 		zero_user_segment(page, 0, PAGE_SIZE);
580 		if (!PageUptodate(page))
581 			SetPageUptodate(page);
582 		unlock_page(page);
583 		return page;
584 	}
585 
586 	fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
587 	fio.page = page;
588 	err = f2fs_submit_page_bio(&fio);
589 	if (err)
590 		goto put_err;
591 	return page;
592 
593 put_err:
594 	f2fs_put_page(page, 1);
595 	return ERR_PTR(err);
596 }
597 
598 struct page *find_data_page(struct inode *inode, pgoff_t index)
599 {
600 	struct address_space *mapping = inode->i_mapping;
601 	struct page *page;
602 
603 	page = find_get_page(mapping, index);
604 	if (page && PageUptodate(page))
605 		return page;
606 	f2fs_put_page(page, 0);
607 
608 	page = get_read_data_page(inode, index, 0, false);
609 	if (IS_ERR(page))
610 		return page;
611 
612 	if (PageUptodate(page))
613 		return page;
614 
615 	wait_on_page_locked(page);
616 	if (unlikely(!PageUptodate(page))) {
617 		f2fs_put_page(page, 0);
618 		return ERR_PTR(-EIO);
619 	}
620 	return page;
621 }
622 
623 /*
624  * If it tries to access a hole, return an error.
625  * Because, the callers, functions in dir.c and GC, should be able to know
626  * whether this page exists or not.
627  */
628 struct page *get_lock_data_page(struct inode *inode, pgoff_t index,
629 							bool for_write)
630 {
631 	struct address_space *mapping = inode->i_mapping;
632 	struct page *page;
633 repeat:
634 	page = get_read_data_page(inode, index, 0, for_write);
635 	if (IS_ERR(page))
636 		return page;
637 
638 	/* wait for read completion */
639 	lock_page(page);
640 	if (unlikely(page->mapping != mapping)) {
641 		f2fs_put_page(page, 1);
642 		goto repeat;
643 	}
644 	if (unlikely(!PageUptodate(page))) {
645 		f2fs_put_page(page, 1);
646 		return ERR_PTR(-EIO);
647 	}
648 	return page;
649 }
650 
651 /*
652  * Caller ensures that this data page is never allocated.
653  * A new zero-filled data page is allocated in the page cache.
654  *
655  * Also, caller should grab and release a rwsem by calling f2fs_lock_op() and
656  * f2fs_unlock_op().
657  * Note that, ipage is set only by make_empty_dir, and if any error occur,
658  * ipage should be released by this function.
659  */
660 struct page *get_new_data_page(struct inode *inode,
661 		struct page *ipage, pgoff_t index, bool new_i_size)
662 {
663 	struct address_space *mapping = inode->i_mapping;
664 	struct page *page;
665 	struct dnode_of_data dn;
666 	int err;
667 
668 	page = f2fs_grab_cache_page(mapping, index, true);
669 	if (!page) {
670 		/*
671 		 * before exiting, we should make sure ipage will be released
672 		 * if any error occur.
673 		 */
674 		f2fs_put_page(ipage, 1);
675 		return ERR_PTR(-ENOMEM);
676 	}
677 
678 	set_new_dnode(&dn, inode, ipage, NULL, 0);
679 	err = f2fs_reserve_block(&dn, index);
680 	if (err) {
681 		f2fs_put_page(page, 1);
682 		return ERR_PTR(err);
683 	}
684 	if (!ipage)
685 		f2fs_put_dnode(&dn);
686 
687 	if (PageUptodate(page))
688 		goto got_it;
689 
690 	if (dn.data_blkaddr == NEW_ADDR) {
691 		zero_user_segment(page, 0, PAGE_SIZE);
692 		if (!PageUptodate(page))
693 			SetPageUptodate(page);
694 	} else {
695 		f2fs_put_page(page, 1);
696 
697 		/* if ipage exists, blkaddr should be NEW_ADDR */
698 		f2fs_bug_on(F2FS_I_SB(inode), ipage);
699 		page = get_lock_data_page(inode, index, true);
700 		if (IS_ERR(page))
701 			return page;
702 	}
703 got_it:
704 	if (new_i_size && i_size_read(inode) <
705 				((loff_t)(index + 1) << PAGE_SHIFT))
706 		f2fs_i_size_write(inode, ((loff_t)(index + 1) << PAGE_SHIFT));
707 	return page;
708 }
709 
710 static int __allocate_data_block(struct dnode_of_data *dn)
711 {
712 	struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
713 	struct f2fs_summary sum;
714 	struct node_info ni;
715 	pgoff_t fofs;
716 	blkcnt_t count = 1;
717 
718 	if (unlikely(is_inode_flag_set(dn->inode, FI_NO_ALLOC)))
719 		return -EPERM;
720 
721 	dn->data_blkaddr = datablock_addr(dn->node_page, dn->ofs_in_node);
722 	if (dn->data_blkaddr == NEW_ADDR)
723 		goto alloc;
724 
725 	if (unlikely(!inc_valid_block_count(sbi, dn->inode, &count)))
726 		return -ENOSPC;
727 
728 alloc:
729 	get_node_info(sbi, dn->nid, &ni);
730 	set_summary(&sum, dn->nid, dn->ofs_in_node, ni.version);
731 
732 	allocate_data_block(sbi, NULL, dn->data_blkaddr, &dn->data_blkaddr,
733 						&sum, CURSEG_WARM_DATA);
734 	set_data_blkaddr(dn);
735 
736 	/* update i_size */
737 	fofs = start_bidx_of_node(ofs_of_node(dn->node_page), dn->inode) +
738 							dn->ofs_in_node;
739 	if (i_size_read(dn->inode) < ((loff_t)(fofs + 1) << PAGE_SHIFT))
740 		f2fs_i_size_write(dn->inode,
741 				((loff_t)(fofs + 1) << PAGE_SHIFT));
742 	return 0;
743 }
744 
745 static inline bool __force_buffered_io(struct inode *inode, int rw)
746 {
747 	return ((f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode)) ||
748 			(rw == WRITE && test_opt(F2FS_I_SB(inode), LFS)) ||
749 			F2FS_I_SB(inode)->s_ndevs);
750 }
751 
752 int f2fs_preallocate_blocks(struct kiocb *iocb, struct iov_iter *from)
753 {
754 	struct inode *inode = file_inode(iocb->ki_filp);
755 	struct f2fs_map_blocks map;
756 	int err = 0;
757 
758 	if (is_inode_flag_set(inode, FI_NO_PREALLOC))
759 		return 0;
760 
761 	map.m_lblk = F2FS_BLK_ALIGN(iocb->ki_pos);
762 	map.m_len = F2FS_BYTES_TO_BLK(iocb->ki_pos + iov_iter_count(from));
763 	if (map.m_len > map.m_lblk)
764 		map.m_len -= map.m_lblk;
765 	else
766 		map.m_len = 0;
767 
768 	map.m_next_pgofs = NULL;
769 
770 	if (iocb->ki_flags & IOCB_DIRECT) {
771 		err = f2fs_convert_inline_inode(inode);
772 		if (err)
773 			return err;
774 		return f2fs_map_blocks(inode, &map, 1,
775 			__force_buffered_io(inode, WRITE) ?
776 				F2FS_GET_BLOCK_PRE_AIO :
777 				F2FS_GET_BLOCK_PRE_DIO);
778 	}
779 	if (iocb->ki_pos + iov_iter_count(from) > MAX_INLINE_DATA) {
780 		err = f2fs_convert_inline_inode(inode);
781 		if (err)
782 			return err;
783 	}
784 	if (!f2fs_has_inline_data(inode))
785 		return f2fs_map_blocks(inode, &map, 1, F2FS_GET_BLOCK_PRE_AIO);
786 	return err;
787 }
788 
789 /*
790  * f2fs_map_blocks() now supported readahead/bmap/rw direct_IO with
791  * f2fs_map_blocks structure.
792  * If original data blocks are allocated, then give them to blockdev.
793  * Otherwise,
794  *     a. preallocate requested block addresses
795  *     b. do not use extent cache for better performance
796  *     c. give the block addresses to blockdev
797  */
798 int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map,
799 						int create, int flag)
800 {
801 	unsigned int maxblocks = map->m_len;
802 	struct dnode_of_data dn;
803 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
804 	int mode = create ? ALLOC_NODE : LOOKUP_NODE;
805 	pgoff_t pgofs, end_offset, end;
806 	int err = 0, ofs = 1;
807 	unsigned int ofs_in_node, last_ofs_in_node;
808 	blkcnt_t prealloc;
809 	struct extent_info ei = {0,0,0};
810 	block_t blkaddr;
811 
812 	if (!maxblocks)
813 		return 0;
814 
815 	map->m_len = 0;
816 	map->m_flags = 0;
817 
818 	/* it only supports block size == page size */
819 	pgofs =	(pgoff_t)map->m_lblk;
820 	end = pgofs + maxblocks;
821 
822 	if (!create && f2fs_lookup_extent_cache(inode, pgofs, &ei)) {
823 		map->m_pblk = ei.blk + pgofs - ei.fofs;
824 		map->m_len = min((pgoff_t)maxblocks, ei.fofs + ei.len - pgofs);
825 		map->m_flags = F2FS_MAP_MAPPED;
826 		goto out;
827 	}
828 
829 next_dnode:
830 	if (create)
831 		f2fs_lock_op(sbi);
832 
833 	/* When reading holes, we need its node page */
834 	set_new_dnode(&dn, inode, NULL, NULL, 0);
835 	err = get_dnode_of_data(&dn, pgofs, mode);
836 	if (err) {
837 		if (flag == F2FS_GET_BLOCK_BMAP)
838 			map->m_pblk = 0;
839 		if (err == -ENOENT) {
840 			err = 0;
841 			if (map->m_next_pgofs)
842 				*map->m_next_pgofs =
843 					get_next_page_offset(&dn, pgofs);
844 		}
845 		goto unlock_out;
846 	}
847 
848 	prealloc = 0;
849 	last_ofs_in_node = ofs_in_node = dn.ofs_in_node;
850 	end_offset = ADDRS_PER_PAGE(dn.node_page, inode);
851 
852 next_block:
853 	blkaddr = datablock_addr(dn.node_page, dn.ofs_in_node);
854 
855 	if (blkaddr == NEW_ADDR || blkaddr == NULL_ADDR) {
856 		if (create) {
857 			if (unlikely(f2fs_cp_error(sbi))) {
858 				err = -EIO;
859 				goto sync_out;
860 			}
861 			if (flag == F2FS_GET_BLOCK_PRE_AIO) {
862 				if (blkaddr == NULL_ADDR) {
863 					prealloc++;
864 					last_ofs_in_node = dn.ofs_in_node;
865 				}
866 			} else {
867 				err = __allocate_data_block(&dn);
868 				if (!err)
869 					set_inode_flag(inode, FI_APPEND_WRITE);
870 			}
871 			if (err)
872 				goto sync_out;
873 			map->m_flags |= F2FS_MAP_NEW;
874 			blkaddr = dn.data_blkaddr;
875 		} else {
876 			if (flag == F2FS_GET_BLOCK_BMAP) {
877 				map->m_pblk = 0;
878 				goto sync_out;
879 			}
880 			if (flag == F2FS_GET_BLOCK_FIEMAP &&
881 						blkaddr == NULL_ADDR) {
882 				if (map->m_next_pgofs)
883 					*map->m_next_pgofs = pgofs + 1;
884 			}
885 			if (flag != F2FS_GET_BLOCK_FIEMAP ||
886 						blkaddr != NEW_ADDR)
887 				goto sync_out;
888 		}
889 	}
890 
891 	if (flag == F2FS_GET_BLOCK_PRE_AIO)
892 		goto skip;
893 
894 	if (map->m_len == 0) {
895 		/* preallocated unwritten block should be mapped for fiemap. */
896 		if (blkaddr == NEW_ADDR)
897 			map->m_flags |= F2FS_MAP_UNWRITTEN;
898 		map->m_flags |= F2FS_MAP_MAPPED;
899 
900 		map->m_pblk = blkaddr;
901 		map->m_len = 1;
902 	} else if ((map->m_pblk != NEW_ADDR &&
903 			blkaddr == (map->m_pblk + ofs)) ||
904 			(map->m_pblk == NEW_ADDR && blkaddr == NEW_ADDR) ||
905 			flag == F2FS_GET_BLOCK_PRE_DIO) {
906 		ofs++;
907 		map->m_len++;
908 	} else {
909 		goto sync_out;
910 	}
911 
912 skip:
913 	dn.ofs_in_node++;
914 	pgofs++;
915 
916 	/* preallocate blocks in batch for one dnode page */
917 	if (flag == F2FS_GET_BLOCK_PRE_AIO &&
918 			(pgofs == end || dn.ofs_in_node == end_offset)) {
919 
920 		dn.ofs_in_node = ofs_in_node;
921 		err = reserve_new_blocks(&dn, prealloc);
922 		if (err)
923 			goto sync_out;
924 
925 		map->m_len += dn.ofs_in_node - ofs_in_node;
926 		if (prealloc && dn.ofs_in_node != last_ofs_in_node + 1) {
927 			err = -ENOSPC;
928 			goto sync_out;
929 		}
930 		dn.ofs_in_node = end_offset;
931 	}
932 
933 	if (pgofs >= end)
934 		goto sync_out;
935 	else if (dn.ofs_in_node < end_offset)
936 		goto next_block;
937 
938 	f2fs_put_dnode(&dn);
939 
940 	if (create) {
941 		f2fs_unlock_op(sbi);
942 		f2fs_balance_fs(sbi, dn.node_changed);
943 	}
944 	goto next_dnode;
945 
946 sync_out:
947 	f2fs_put_dnode(&dn);
948 unlock_out:
949 	if (create) {
950 		f2fs_unlock_op(sbi);
951 		f2fs_balance_fs(sbi, dn.node_changed);
952 	}
953 out:
954 	trace_f2fs_map_blocks(inode, map, err);
955 	return err;
956 }
957 
958 static int __get_data_block(struct inode *inode, sector_t iblock,
959 			struct buffer_head *bh, int create, int flag,
960 			pgoff_t *next_pgofs)
961 {
962 	struct f2fs_map_blocks map;
963 	int err;
964 
965 	map.m_lblk = iblock;
966 	map.m_len = bh->b_size >> inode->i_blkbits;
967 	map.m_next_pgofs = next_pgofs;
968 
969 	err = f2fs_map_blocks(inode, &map, create, flag);
970 	if (!err) {
971 		map_bh(bh, inode->i_sb, map.m_pblk);
972 		bh->b_state = (bh->b_state & ~F2FS_MAP_FLAGS) | map.m_flags;
973 		bh->b_size = (u64)map.m_len << inode->i_blkbits;
974 	}
975 	return err;
976 }
977 
978 static int get_data_block(struct inode *inode, sector_t iblock,
979 			struct buffer_head *bh_result, int create, int flag,
980 			pgoff_t *next_pgofs)
981 {
982 	return __get_data_block(inode, iblock, bh_result, create,
983 							flag, next_pgofs);
984 }
985 
986 static int get_data_block_dio(struct inode *inode, sector_t iblock,
987 			struct buffer_head *bh_result, int create)
988 {
989 	return __get_data_block(inode, iblock, bh_result, create,
990 						F2FS_GET_BLOCK_DIO, NULL);
991 }
992 
993 static int get_data_block_bmap(struct inode *inode, sector_t iblock,
994 			struct buffer_head *bh_result, int create)
995 {
996 	/* Block number less than F2FS MAX BLOCKS */
997 	if (unlikely(iblock >= F2FS_I_SB(inode)->max_file_blocks))
998 		return -EFBIG;
999 
1000 	return __get_data_block(inode, iblock, bh_result, create,
1001 						F2FS_GET_BLOCK_BMAP, NULL);
1002 }
1003 
1004 static inline sector_t logical_to_blk(struct inode *inode, loff_t offset)
1005 {
1006 	return (offset >> inode->i_blkbits);
1007 }
1008 
1009 static inline loff_t blk_to_logical(struct inode *inode, sector_t blk)
1010 {
1011 	return (blk << inode->i_blkbits);
1012 }
1013 
1014 int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
1015 		u64 start, u64 len)
1016 {
1017 	struct buffer_head map_bh;
1018 	sector_t start_blk, last_blk;
1019 	pgoff_t next_pgofs;
1020 	u64 logical = 0, phys = 0, size = 0;
1021 	u32 flags = 0;
1022 	int ret = 0;
1023 
1024 	ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC);
1025 	if (ret)
1026 		return ret;
1027 
1028 	if (f2fs_has_inline_data(inode)) {
1029 		ret = f2fs_inline_data_fiemap(inode, fieinfo, start, len);
1030 		if (ret != -EAGAIN)
1031 			return ret;
1032 	}
1033 
1034 	inode_lock(inode);
1035 
1036 	if (logical_to_blk(inode, len) == 0)
1037 		len = blk_to_logical(inode, 1);
1038 
1039 	start_blk = logical_to_blk(inode, start);
1040 	last_blk = logical_to_blk(inode, start + len - 1);
1041 
1042 next:
1043 	memset(&map_bh, 0, sizeof(struct buffer_head));
1044 	map_bh.b_size = len;
1045 
1046 	ret = get_data_block(inode, start_blk, &map_bh, 0,
1047 					F2FS_GET_BLOCK_FIEMAP, &next_pgofs);
1048 	if (ret)
1049 		goto out;
1050 
1051 	/* HOLE */
1052 	if (!buffer_mapped(&map_bh)) {
1053 		start_blk = next_pgofs;
1054 
1055 		if (blk_to_logical(inode, start_blk) < blk_to_logical(inode,
1056 					F2FS_I_SB(inode)->max_file_blocks))
1057 			goto prep_next;
1058 
1059 		flags |= FIEMAP_EXTENT_LAST;
1060 	}
1061 
1062 	if (size) {
1063 		if (f2fs_encrypted_inode(inode))
1064 			flags |= FIEMAP_EXTENT_DATA_ENCRYPTED;
1065 
1066 		ret = fiemap_fill_next_extent(fieinfo, logical,
1067 				phys, size, flags);
1068 	}
1069 
1070 	if (start_blk > last_blk || ret)
1071 		goto out;
1072 
1073 	logical = blk_to_logical(inode, start_blk);
1074 	phys = blk_to_logical(inode, map_bh.b_blocknr);
1075 	size = map_bh.b_size;
1076 	flags = 0;
1077 	if (buffer_unwritten(&map_bh))
1078 		flags = FIEMAP_EXTENT_UNWRITTEN;
1079 
1080 	start_blk += logical_to_blk(inode, size);
1081 
1082 prep_next:
1083 	cond_resched();
1084 	if (fatal_signal_pending(current))
1085 		ret = -EINTR;
1086 	else
1087 		goto next;
1088 out:
1089 	if (ret == 1)
1090 		ret = 0;
1091 
1092 	inode_unlock(inode);
1093 	return ret;
1094 }
1095 
1096 static struct bio *f2fs_grab_bio(struct inode *inode, block_t blkaddr,
1097 				 unsigned nr_pages)
1098 {
1099 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1100 	struct fscrypt_ctx *ctx = NULL;
1101 	struct bio *bio;
1102 
1103 	if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode)) {
1104 		ctx = fscrypt_get_ctx(inode, GFP_NOFS);
1105 		if (IS_ERR(ctx))
1106 			return ERR_CAST(ctx);
1107 
1108 		/* wait the page to be moved by cleaning */
1109 		f2fs_wait_on_encrypted_page_writeback(sbi, blkaddr);
1110 	}
1111 
1112 	bio = bio_alloc(GFP_KERNEL, min_t(int, nr_pages, BIO_MAX_PAGES));
1113 	if (!bio) {
1114 		if (ctx)
1115 			fscrypt_release_ctx(ctx);
1116 		return ERR_PTR(-ENOMEM);
1117 	}
1118 	f2fs_target_device(sbi, blkaddr, bio);
1119 	bio->bi_end_io = f2fs_read_end_io;
1120 	bio->bi_private = ctx;
1121 
1122 	return bio;
1123 }
1124 
1125 /*
1126  * This function was originally taken from fs/mpage.c, and customized for f2fs.
1127  * Major change was from block_size == page_size in f2fs by default.
1128  */
1129 static int f2fs_mpage_readpages(struct address_space *mapping,
1130 			struct list_head *pages, struct page *page,
1131 			unsigned nr_pages)
1132 {
1133 	struct bio *bio = NULL;
1134 	unsigned page_idx;
1135 	sector_t last_block_in_bio = 0;
1136 	struct inode *inode = mapping->host;
1137 	const unsigned blkbits = inode->i_blkbits;
1138 	const unsigned blocksize = 1 << blkbits;
1139 	sector_t block_in_file;
1140 	sector_t last_block;
1141 	sector_t last_block_in_file;
1142 	sector_t block_nr;
1143 	struct f2fs_map_blocks map;
1144 
1145 	map.m_pblk = 0;
1146 	map.m_lblk = 0;
1147 	map.m_len = 0;
1148 	map.m_flags = 0;
1149 	map.m_next_pgofs = NULL;
1150 
1151 	for (page_idx = 0; nr_pages; page_idx++, nr_pages--) {
1152 
1153 		prefetchw(&page->flags);
1154 		if (pages) {
1155 			page = list_last_entry(pages, struct page, lru);
1156 			list_del(&page->lru);
1157 			if (add_to_page_cache_lru(page, mapping,
1158 						  page->index,
1159 						  readahead_gfp_mask(mapping)))
1160 				goto next_page;
1161 		}
1162 
1163 		block_in_file = (sector_t)page->index;
1164 		last_block = block_in_file + nr_pages;
1165 		last_block_in_file = (i_size_read(inode) + blocksize - 1) >>
1166 								blkbits;
1167 		if (last_block > last_block_in_file)
1168 			last_block = last_block_in_file;
1169 
1170 		/*
1171 		 * Map blocks using the previous result first.
1172 		 */
1173 		if ((map.m_flags & F2FS_MAP_MAPPED) &&
1174 				block_in_file > map.m_lblk &&
1175 				block_in_file < (map.m_lblk + map.m_len))
1176 			goto got_it;
1177 
1178 		/*
1179 		 * Then do more f2fs_map_blocks() calls until we are
1180 		 * done with this page.
1181 		 */
1182 		map.m_flags = 0;
1183 
1184 		if (block_in_file < last_block) {
1185 			map.m_lblk = block_in_file;
1186 			map.m_len = last_block - block_in_file;
1187 
1188 			if (f2fs_map_blocks(inode, &map, 0,
1189 						F2FS_GET_BLOCK_READ))
1190 				goto set_error_page;
1191 		}
1192 got_it:
1193 		if ((map.m_flags & F2FS_MAP_MAPPED)) {
1194 			block_nr = map.m_pblk + block_in_file - map.m_lblk;
1195 			SetPageMappedToDisk(page);
1196 
1197 			if (!PageUptodate(page) && !cleancache_get_page(page)) {
1198 				SetPageUptodate(page);
1199 				goto confused;
1200 			}
1201 		} else {
1202 			zero_user_segment(page, 0, PAGE_SIZE);
1203 			if (!PageUptodate(page))
1204 				SetPageUptodate(page);
1205 			unlock_page(page);
1206 			goto next_page;
1207 		}
1208 
1209 		/*
1210 		 * This page will go to BIO.  Do we need to send this
1211 		 * BIO off first?
1212 		 */
1213 		if (bio && (last_block_in_bio != block_nr - 1 ||
1214 			!__same_bdev(F2FS_I_SB(inode), block_nr, bio))) {
1215 submit_and_realloc:
1216 			__submit_bio(F2FS_I_SB(inode), bio, DATA);
1217 			bio = NULL;
1218 		}
1219 		if (bio == NULL) {
1220 			bio = f2fs_grab_bio(inode, block_nr, nr_pages);
1221 			if (IS_ERR(bio)) {
1222 				bio = NULL;
1223 				goto set_error_page;
1224 			}
1225 			bio_set_op_attrs(bio, REQ_OP_READ, 0);
1226 		}
1227 
1228 		if (bio_add_page(bio, page, blocksize, 0) < blocksize)
1229 			goto submit_and_realloc;
1230 
1231 		last_block_in_bio = block_nr;
1232 		goto next_page;
1233 set_error_page:
1234 		SetPageError(page);
1235 		zero_user_segment(page, 0, PAGE_SIZE);
1236 		unlock_page(page);
1237 		goto next_page;
1238 confused:
1239 		if (bio) {
1240 			__submit_bio(F2FS_I_SB(inode), bio, DATA);
1241 			bio = NULL;
1242 		}
1243 		unlock_page(page);
1244 next_page:
1245 		if (pages)
1246 			put_page(page);
1247 	}
1248 	BUG_ON(pages && !list_empty(pages));
1249 	if (bio)
1250 		__submit_bio(F2FS_I_SB(inode), bio, DATA);
1251 	return 0;
1252 }
1253 
1254 static int f2fs_read_data_page(struct file *file, struct page *page)
1255 {
1256 	struct inode *inode = page->mapping->host;
1257 	int ret = -EAGAIN;
1258 
1259 	trace_f2fs_readpage(page, DATA);
1260 
1261 	/* If the file has inline data, try to read it directly */
1262 	if (f2fs_has_inline_data(inode))
1263 		ret = f2fs_read_inline_data(inode, page);
1264 	if (ret == -EAGAIN)
1265 		ret = f2fs_mpage_readpages(page->mapping, NULL, page, 1);
1266 	return ret;
1267 }
1268 
1269 static int f2fs_read_data_pages(struct file *file,
1270 			struct address_space *mapping,
1271 			struct list_head *pages, unsigned nr_pages)
1272 {
1273 	struct inode *inode = file->f_mapping->host;
1274 	struct page *page = list_last_entry(pages, struct page, lru);
1275 
1276 	trace_f2fs_readpages(inode, page, nr_pages);
1277 
1278 	/* If the file has inline data, skip readpages */
1279 	if (f2fs_has_inline_data(inode))
1280 		return 0;
1281 
1282 	return f2fs_mpage_readpages(mapping, pages, NULL, nr_pages);
1283 }
1284 
1285 int do_write_data_page(struct f2fs_io_info *fio)
1286 {
1287 	struct page *page = fio->page;
1288 	struct inode *inode = page->mapping->host;
1289 	struct dnode_of_data dn;
1290 	int err = 0;
1291 
1292 	set_new_dnode(&dn, inode, NULL, NULL, 0);
1293 	err = get_dnode_of_data(&dn, page->index, LOOKUP_NODE);
1294 	if (err)
1295 		return err;
1296 
1297 	fio->old_blkaddr = dn.data_blkaddr;
1298 
1299 	/* This page is already truncated */
1300 	if (fio->old_blkaddr == NULL_ADDR) {
1301 		ClearPageUptodate(page);
1302 		goto out_writepage;
1303 	}
1304 
1305 	if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode)) {
1306 		gfp_t gfp_flags = GFP_NOFS;
1307 
1308 		/* wait for GCed encrypted page writeback */
1309 		f2fs_wait_on_encrypted_page_writeback(F2FS_I_SB(inode),
1310 							fio->old_blkaddr);
1311 retry_encrypt:
1312 		fio->encrypted_page = fscrypt_encrypt_page(inode, fio->page,
1313 							PAGE_SIZE, 0,
1314 							fio->page->index,
1315 							gfp_flags);
1316 		if (IS_ERR(fio->encrypted_page)) {
1317 			err = PTR_ERR(fio->encrypted_page);
1318 			if (err == -ENOMEM) {
1319 				/* flush pending ios and wait for a while */
1320 				f2fs_flush_merged_bios(F2FS_I_SB(inode));
1321 				congestion_wait(BLK_RW_ASYNC, HZ/50);
1322 				gfp_flags |= __GFP_NOFAIL;
1323 				err = 0;
1324 				goto retry_encrypt;
1325 			}
1326 			goto out_writepage;
1327 		}
1328 	}
1329 
1330 	set_page_writeback(page);
1331 
1332 	/*
1333 	 * If current allocation needs SSR,
1334 	 * it had better in-place writes for updated data.
1335 	 */
1336 	if (unlikely(fio->old_blkaddr != NEW_ADDR &&
1337 			!is_cold_data(page) &&
1338 			!IS_ATOMIC_WRITTEN_PAGE(page) &&
1339 			need_inplace_update(inode))) {
1340 		rewrite_data_page(fio);
1341 		set_inode_flag(inode, FI_UPDATE_WRITE);
1342 		trace_f2fs_do_write_data_page(page, IPU);
1343 	} else {
1344 		write_data_page(&dn, fio);
1345 		trace_f2fs_do_write_data_page(page, OPU);
1346 		set_inode_flag(inode, FI_APPEND_WRITE);
1347 		if (page->index == 0)
1348 			set_inode_flag(inode, FI_FIRST_BLOCK_WRITTEN);
1349 	}
1350 out_writepage:
1351 	f2fs_put_dnode(&dn);
1352 	return err;
1353 }
1354 
1355 static int __write_data_page(struct page *page, bool *submitted,
1356 				struct writeback_control *wbc)
1357 {
1358 	struct inode *inode = page->mapping->host;
1359 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1360 	loff_t i_size = i_size_read(inode);
1361 	const pgoff_t end_index = ((unsigned long long) i_size)
1362 							>> PAGE_SHIFT;
1363 	loff_t psize = (page->index + 1) << PAGE_SHIFT;
1364 	unsigned offset = 0;
1365 	bool need_balance_fs = false;
1366 	int err = 0;
1367 	struct f2fs_io_info fio = {
1368 		.sbi = sbi,
1369 		.type = DATA,
1370 		.op = REQ_OP_WRITE,
1371 		.op_flags = wbc_to_write_flags(wbc),
1372 		.page = page,
1373 		.encrypted_page = NULL,
1374 		.submitted = false,
1375 	};
1376 
1377 	trace_f2fs_writepage(page, DATA);
1378 
1379 	if (page->index < end_index)
1380 		goto write;
1381 
1382 	/*
1383 	 * If the offset is out-of-range of file size,
1384 	 * this page does not have to be written to disk.
1385 	 */
1386 	offset = i_size & (PAGE_SIZE - 1);
1387 	if ((page->index >= end_index + 1) || !offset)
1388 		goto out;
1389 
1390 	zero_user_segment(page, offset, PAGE_SIZE);
1391 write:
1392 	if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
1393 		goto redirty_out;
1394 	if (f2fs_is_drop_cache(inode))
1395 		goto out;
1396 	/* we should not write 0'th page having journal header */
1397 	if (f2fs_is_volatile_file(inode) && (!page->index ||
1398 			(!wbc->for_reclaim &&
1399 			available_free_memory(sbi, BASE_CHECK))))
1400 		goto redirty_out;
1401 
1402 	/* we should bypass data pages to proceed the kworkder jobs */
1403 	if (unlikely(f2fs_cp_error(sbi))) {
1404 		mapping_set_error(page->mapping, -EIO);
1405 		goto out;
1406 	}
1407 
1408 	/* Dentry blocks are controlled by checkpoint */
1409 	if (S_ISDIR(inode->i_mode)) {
1410 		err = do_write_data_page(&fio);
1411 		goto done;
1412 	}
1413 
1414 	if (!wbc->for_reclaim)
1415 		need_balance_fs = true;
1416 	else if (has_not_enough_free_secs(sbi, 0, 0))
1417 		goto redirty_out;
1418 
1419 	err = -EAGAIN;
1420 	if (f2fs_has_inline_data(inode)) {
1421 		err = f2fs_write_inline_data(inode, page);
1422 		if (!err)
1423 			goto out;
1424 	}
1425 	f2fs_lock_op(sbi);
1426 	if (err == -EAGAIN)
1427 		err = do_write_data_page(&fio);
1428 	if (F2FS_I(inode)->last_disk_size < psize)
1429 		F2FS_I(inode)->last_disk_size = psize;
1430 	f2fs_unlock_op(sbi);
1431 done:
1432 	if (err && err != -ENOENT)
1433 		goto redirty_out;
1434 
1435 out:
1436 	inode_dec_dirty_pages(inode);
1437 	if (err)
1438 		ClearPageUptodate(page);
1439 
1440 	if (wbc->for_reclaim) {
1441 		f2fs_submit_merged_bio_cond(sbi, inode, 0, page->index,
1442 						DATA, WRITE);
1443 		remove_dirty_inode(inode);
1444 		submitted = NULL;
1445 	}
1446 
1447 	unlock_page(page);
1448 	f2fs_balance_fs(sbi, need_balance_fs);
1449 
1450 	if (unlikely(f2fs_cp_error(sbi))) {
1451 		f2fs_submit_merged_bio(sbi, DATA, WRITE);
1452 		submitted = NULL;
1453 	}
1454 
1455 	if (submitted)
1456 		*submitted = fio.submitted;
1457 
1458 	return 0;
1459 
1460 redirty_out:
1461 	redirty_page_for_writepage(wbc, page);
1462 	if (!err)
1463 		return AOP_WRITEPAGE_ACTIVATE;
1464 	unlock_page(page);
1465 	return err;
1466 }
1467 
1468 static int f2fs_write_data_page(struct page *page,
1469 					struct writeback_control *wbc)
1470 {
1471 	return __write_data_page(page, NULL, wbc);
1472 }
1473 
1474 /*
1475  * This function was copied from write_cche_pages from mm/page-writeback.c.
1476  * The major change is making write step of cold data page separately from
1477  * warm/hot data page.
1478  */
1479 static int f2fs_write_cache_pages(struct address_space *mapping,
1480 					struct writeback_control *wbc)
1481 {
1482 	int ret = 0;
1483 	int done = 0;
1484 	struct pagevec pvec;
1485 	int nr_pages;
1486 	pgoff_t uninitialized_var(writeback_index);
1487 	pgoff_t index;
1488 	pgoff_t end;		/* Inclusive */
1489 	pgoff_t done_index;
1490 	pgoff_t last_idx = ULONG_MAX;
1491 	int cycled;
1492 	int range_whole = 0;
1493 	int tag;
1494 
1495 	pagevec_init(&pvec, 0);
1496 
1497 	if (wbc->range_cyclic) {
1498 		writeback_index = mapping->writeback_index; /* prev offset */
1499 		index = writeback_index;
1500 		if (index == 0)
1501 			cycled = 1;
1502 		else
1503 			cycled = 0;
1504 		end = -1;
1505 	} else {
1506 		index = wbc->range_start >> PAGE_SHIFT;
1507 		end = wbc->range_end >> PAGE_SHIFT;
1508 		if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
1509 			range_whole = 1;
1510 		cycled = 1; /* ignore range_cyclic tests */
1511 	}
1512 	if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
1513 		tag = PAGECACHE_TAG_TOWRITE;
1514 	else
1515 		tag = PAGECACHE_TAG_DIRTY;
1516 retry:
1517 	if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
1518 		tag_pages_for_writeback(mapping, index, end);
1519 	done_index = index;
1520 	while (!done && (index <= end)) {
1521 		int i;
1522 
1523 		nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
1524 			      min(end - index, (pgoff_t)PAGEVEC_SIZE - 1) + 1);
1525 		if (nr_pages == 0)
1526 			break;
1527 
1528 		for (i = 0; i < nr_pages; i++) {
1529 			struct page *page = pvec.pages[i];
1530 			bool submitted = false;
1531 
1532 			if (page->index > end) {
1533 				done = 1;
1534 				break;
1535 			}
1536 
1537 			done_index = page->index;
1538 
1539 			lock_page(page);
1540 
1541 			if (unlikely(page->mapping != mapping)) {
1542 continue_unlock:
1543 				unlock_page(page);
1544 				continue;
1545 			}
1546 
1547 			if (!PageDirty(page)) {
1548 				/* someone wrote it for us */
1549 				goto continue_unlock;
1550 			}
1551 
1552 			if (PageWriteback(page)) {
1553 				if (wbc->sync_mode != WB_SYNC_NONE)
1554 					f2fs_wait_on_page_writeback(page,
1555 								DATA, true);
1556 				else
1557 					goto continue_unlock;
1558 			}
1559 
1560 			BUG_ON(PageWriteback(page));
1561 			if (!clear_page_dirty_for_io(page))
1562 				goto continue_unlock;
1563 
1564 			ret = __write_data_page(page, &submitted, wbc);
1565 			if (unlikely(ret)) {
1566 				/*
1567 				 * keep nr_to_write, since vfs uses this to
1568 				 * get # of written pages.
1569 				 */
1570 				if (ret == AOP_WRITEPAGE_ACTIVATE) {
1571 					unlock_page(page);
1572 					ret = 0;
1573 					continue;
1574 				}
1575 				done_index = page->index + 1;
1576 				done = 1;
1577 				break;
1578 			} else if (submitted) {
1579 				last_idx = page->index;
1580 			}
1581 
1582 			if (--wbc->nr_to_write <= 0 &&
1583 			    wbc->sync_mode == WB_SYNC_NONE) {
1584 				done = 1;
1585 				break;
1586 			}
1587 		}
1588 		pagevec_release(&pvec);
1589 		cond_resched();
1590 	}
1591 
1592 	if (!cycled && !done) {
1593 		cycled = 1;
1594 		index = 0;
1595 		end = writeback_index - 1;
1596 		goto retry;
1597 	}
1598 	if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
1599 		mapping->writeback_index = done_index;
1600 
1601 	if (last_idx != ULONG_MAX)
1602 		f2fs_submit_merged_bio_cond(F2FS_M_SB(mapping), mapping->host,
1603 						0, last_idx, DATA, WRITE);
1604 
1605 	return ret;
1606 }
1607 
1608 static int f2fs_write_data_pages(struct address_space *mapping,
1609 			    struct writeback_control *wbc)
1610 {
1611 	struct inode *inode = mapping->host;
1612 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1613 	struct blk_plug plug;
1614 	int ret;
1615 
1616 	/* deal with chardevs and other special file */
1617 	if (!mapping->a_ops->writepage)
1618 		return 0;
1619 
1620 	/* skip writing if there is no dirty page in this inode */
1621 	if (!get_dirty_pages(inode) && wbc->sync_mode == WB_SYNC_NONE)
1622 		return 0;
1623 
1624 	if (S_ISDIR(inode->i_mode) && wbc->sync_mode == WB_SYNC_NONE &&
1625 			get_dirty_pages(inode) < nr_pages_to_skip(sbi, DATA) &&
1626 			available_free_memory(sbi, DIRTY_DENTS))
1627 		goto skip_write;
1628 
1629 	/* skip writing during file defragment */
1630 	if (is_inode_flag_set(inode, FI_DO_DEFRAG))
1631 		goto skip_write;
1632 
1633 	/* during POR, we don't need to trigger writepage at all. */
1634 	if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
1635 		goto skip_write;
1636 
1637 	trace_f2fs_writepages(mapping->host, wbc, DATA);
1638 
1639 	blk_start_plug(&plug);
1640 	ret = f2fs_write_cache_pages(mapping, wbc);
1641 	blk_finish_plug(&plug);
1642 	/*
1643 	 * if some pages were truncated, we cannot guarantee its mapping->host
1644 	 * to detect pending bios.
1645 	 */
1646 
1647 	remove_dirty_inode(inode);
1648 	return ret;
1649 
1650 skip_write:
1651 	wbc->pages_skipped += get_dirty_pages(inode);
1652 	trace_f2fs_writepages(mapping->host, wbc, DATA);
1653 	return 0;
1654 }
1655 
1656 static void f2fs_write_failed(struct address_space *mapping, loff_t to)
1657 {
1658 	struct inode *inode = mapping->host;
1659 	loff_t i_size = i_size_read(inode);
1660 
1661 	if (to > i_size) {
1662 		truncate_pagecache(inode, i_size);
1663 		truncate_blocks(inode, i_size, true);
1664 	}
1665 }
1666 
1667 static int prepare_write_begin(struct f2fs_sb_info *sbi,
1668 			struct page *page, loff_t pos, unsigned len,
1669 			block_t *blk_addr, bool *node_changed)
1670 {
1671 	struct inode *inode = page->mapping->host;
1672 	pgoff_t index = page->index;
1673 	struct dnode_of_data dn;
1674 	struct page *ipage;
1675 	bool locked = false;
1676 	struct extent_info ei = {0,0,0};
1677 	int err = 0;
1678 
1679 	/*
1680 	 * we already allocated all the blocks, so we don't need to get
1681 	 * the block addresses when there is no need to fill the page.
1682 	 */
1683 	if (!f2fs_has_inline_data(inode) && len == PAGE_SIZE &&
1684 			!is_inode_flag_set(inode, FI_NO_PREALLOC))
1685 		return 0;
1686 
1687 	if (f2fs_has_inline_data(inode) ||
1688 			(pos & PAGE_MASK) >= i_size_read(inode)) {
1689 		f2fs_lock_op(sbi);
1690 		locked = true;
1691 	}
1692 restart:
1693 	/* check inline_data */
1694 	ipage = get_node_page(sbi, inode->i_ino);
1695 	if (IS_ERR(ipage)) {
1696 		err = PTR_ERR(ipage);
1697 		goto unlock_out;
1698 	}
1699 
1700 	set_new_dnode(&dn, inode, ipage, ipage, 0);
1701 
1702 	if (f2fs_has_inline_data(inode)) {
1703 		if (pos + len <= MAX_INLINE_DATA) {
1704 			read_inline_data(page, ipage);
1705 			set_inode_flag(inode, FI_DATA_EXIST);
1706 			if (inode->i_nlink)
1707 				set_inline_node(ipage);
1708 		} else {
1709 			err = f2fs_convert_inline_page(&dn, page);
1710 			if (err)
1711 				goto out;
1712 			if (dn.data_blkaddr == NULL_ADDR)
1713 				err = f2fs_get_block(&dn, index);
1714 		}
1715 	} else if (locked) {
1716 		err = f2fs_get_block(&dn, index);
1717 	} else {
1718 		if (f2fs_lookup_extent_cache(inode, index, &ei)) {
1719 			dn.data_blkaddr = ei.blk + index - ei.fofs;
1720 		} else {
1721 			/* hole case */
1722 			err = get_dnode_of_data(&dn, index, LOOKUP_NODE);
1723 			if (err || dn.data_blkaddr == NULL_ADDR) {
1724 				f2fs_put_dnode(&dn);
1725 				f2fs_lock_op(sbi);
1726 				locked = true;
1727 				goto restart;
1728 			}
1729 		}
1730 	}
1731 
1732 	/* convert_inline_page can make node_changed */
1733 	*blk_addr = dn.data_blkaddr;
1734 	*node_changed = dn.node_changed;
1735 out:
1736 	f2fs_put_dnode(&dn);
1737 unlock_out:
1738 	if (locked)
1739 		f2fs_unlock_op(sbi);
1740 	return err;
1741 }
1742 
1743 static int f2fs_write_begin(struct file *file, struct address_space *mapping,
1744 		loff_t pos, unsigned len, unsigned flags,
1745 		struct page **pagep, void **fsdata)
1746 {
1747 	struct inode *inode = mapping->host;
1748 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1749 	struct page *page = NULL;
1750 	pgoff_t index = ((unsigned long long) pos) >> PAGE_SHIFT;
1751 	bool need_balance = false;
1752 	block_t blkaddr = NULL_ADDR;
1753 	int err = 0;
1754 
1755 	trace_f2fs_write_begin(inode, pos, len, flags);
1756 
1757 	/*
1758 	 * We should check this at this moment to avoid deadlock on inode page
1759 	 * and #0 page. The locking rule for inline_data conversion should be:
1760 	 * lock_page(page #0) -> lock_page(inode_page)
1761 	 */
1762 	if (index != 0) {
1763 		err = f2fs_convert_inline_inode(inode);
1764 		if (err)
1765 			goto fail;
1766 	}
1767 repeat:
1768 	/*
1769 	 * Do not use grab_cache_page_write_begin() to avoid deadlock due to
1770 	 * wait_for_stable_page. Will wait that below with our IO control.
1771 	 */
1772 	page = pagecache_get_page(mapping, index,
1773 				FGP_LOCK | FGP_WRITE | FGP_CREAT, GFP_NOFS);
1774 	if (!page) {
1775 		err = -ENOMEM;
1776 		goto fail;
1777 	}
1778 
1779 	*pagep = page;
1780 
1781 	err = prepare_write_begin(sbi, page, pos, len,
1782 					&blkaddr, &need_balance);
1783 	if (err)
1784 		goto fail;
1785 
1786 	if (need_balance && has_not_enough_free_secs(sbi, 0, 0)) {
1787 		unlock_page(page);
1788 		f2fs_balance_fs(sbi, true);
1789 		lock_page(page);
1790 		if (page->mapping != mapping) {
1791 			/* The page got truncated from under us */
1792 			f2fs_put_page(page, 1);
1793 			goto repeat;
1794 		}
1795 	}
1796 
1797 	f2fs_wait_on_page_writeback(page, DATA, false);
1798 
1799 	/* wait for GCed encrypted page writeback */
1800 	if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode))
1801 		f2fs_wait_on_encrypted_page_writeback(sbi, blkaddr);
1802 
1803 	if (len == PAGE_SIZE || PageUptodate(page))
1804 		return 0;
1805 
1806 	if (!(pos & (PAGE_SIZE - 1)) && (pos + len) >= i_size_read(inode)) {
1807 		zero_user_segment(page, len, PAGE_SIZE);
1808 		return 0;
1809 	}
1810 
1811 	if (blkaddr == NEW_ADDR) {
1812 		zero_user_segment(page, 0, PAGE_SIZE);
1813 		SetPageUptodate(page);
1814 	} else {
1815 		struct bio *bio;
1816 
1817 		bio = f2fs_grab_bio(inode, blkaddr, 1);
1818 		if (IS_ERR(bio)) {
1819 			err = PTR_ERR(bio);
1820 			goto fail;
1821 		}
1822 		bio->bi_opf = REQ_OP_READ;
1823 		if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
1824 			bio_put(bio);
1825 			err = -EFAULT;
1826 			goto fail;
1827 		}
1828 
1829 		__submit_bio(sbi, bio, DATA);
1830 
1831 		lock_page(page);
1832 		if (unlikely(page->mapping != mapping)) {
1833 			f2fs_put_page(page, 1);
1834 			goto repeat;
1835 		}
1836 		if (unlikely(!PageUptodate(page))) {
1837 			err = -EIO;
1838 			goto fail;
1839 		}
1840 	}
1841 	return 0;
1842 
1843 fail:
1844 	f2fs_put_page(page, 1);
1845 	f2fs_write_failed(mapping, pos + len);
1846 	return err;
1847 }
1848 
1849 static int f2fs_write_end(struct file *file,
1850 			struct address_space *mapping,
1851 			loff_t pos, unsigned len, unsigned copied,
1852 			struct page *page, void *fsdata)
1853 {
1854 	struct inode *inode = page->mapping->host;
1855 
1856 	trace_f2fs_write_end(inode, pos, len, copied);
1857 
1858 	/*
1859 	 * This should be come from len == PAGE_SIZE, and we expect copied
1860 	 * should be PAGE_SIZE. Otherwise, we treat it with zero copied and
1861 	 * let generic_perform_write() try to copy data again through copied=0.
1862 	 */
1863 	if (!PageUptodate(page)) {
1864 		if (unlikely(copied != len))
1865 			copied = 0;
1866 		else
1867 			SetPageUptodate(page);
1868 	}
1869 	if (!copied)
1870 		goto unlock_out;
1871 
1872 	set_page_dirty(page);
1873 
1874 	if (pos + copied > i_size_read(inode))
1875 		f2fs_i_size_write(inode, pos + copied);
1876 unlock_out:
1877 	f2fs_put_page(page, 1);
1878 	f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
1879 	return copied;
1880 }
1881 
1882 static int check_direct_IO(struct inode *inode, struct iov_iter *iter,
1883 			   loff_t offset)
1884 {
1885 	unsigned blocksize_mask = inode->i_sb->s_blocksize - 1;
1886 
1887 	if (offset & blocksize_mask)
1888 		return -EINVAL;
1889 
1890 	if (iov_iter_alignment(iter) & blocksize_mask)
1891 		return -EINVAL;
1892 
1893 	return 0;
1894 }
1895 
1896 static ssize_t f2fs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
1897 {
1898 	struct address_space *mapping = iocb->ki_filp->f_mapping;
1899 	struct inode *inode = mapping->host;
1900 	size_t count = iov_iter_count(iter);
1901 	loff_t offset = iocb->ki_pos;
1902 	int rw = iov_iter_rw(iter);
1903 	int err;
1904 
1905 	err = check_direct_IO(inode, iter, offset);
1906 	if (err)
1907 		return err;
1908 
1909 	if (__force_buffered_io(inode, rw))
1910 		return 0;
1911 
1912 	trace_f2fs_direct_IO_enter(inode, offset, count, rw);
1913 
1914 	down_read(&F2FS_I(inode)->dio_rwsem[rw]);
1915 	err = blockdev_direct_IO(iocb, inode, iter, get_data_block_dio);
1916 	up_read(&F2FS_I(inode)->dio_rwsem[rw]);
1917 
1918 	if (rw == WRITE) {
1919 		if (err > 0)
1920 			set_inode_flag(inode, FI_UPDATE_WRITE);
1921 		else if (err < 0)
1922 			f2fs_write_failed(mapping, offset + count);
1923 	}
1924 
1925 	trace_f2fs_direct_IO_exit(inode, offset, count, rw, err);
1926 
1927 	return err;
1928 }
1929 
1930 void f2fs_invalidate_page(struct page *page, unsigned int offset,
1931 							unsigned int length)
1932 {
1933 	struct inode *inode = page->mapping->host;
1934 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1935 
1936 	if (inode->i_ino >= F2FS_ROOT_INO(sbi) &&
1937 		(offset % PAGE_SIZE || length != PAGE_SIZE))
1938 		return;
1939 
1940 	if (PageDirty(page)) {
1941 		if (inode->i_ino == F2FS_META_INO(sbi)) {
1942 			dec_page_count(sbi, F2FS_DIRTY_META);
1943 		} else if (inode->i_ino == F2FS_NODE_INO(sbi)) {
1944 			dec_page_count(sbi, F2FS_DIRTY_NODES);
1945 		} else {
1946 			inode_dec_dirty_pages(inode);
1947 			remove_dirty_inode(inode);
1948 		}
1949 	}
1950 
1951 	/* This is atomic written page, keep Private */
1952 	if (IS_ATOMIC_WRITTEN_PAGE(page))
1953 		return;
1954 
1955 	set_page_private(page, 0);
1956 	ClearPagePrivate(page);
1957 }
1958 
1959 int f2fs_release_page(struct page *page, gfp_t wait)
1960 {
1961 	/* If this is dirty page, keep PagePrivate */
1962 	if (PageDirty(page))
1963 		return 0;
1964 
1965 	/* This is atomic written page, keep Private */
1966 	if (IS_ATOMIC_WRITTEN_PAGE(page))
1967 		return 0;
1968 
1969 	set_page_private(page, 0);
1970 	ClearPagePrivate(page);
1971 	return 1;
1972 }
1973 
1974 /*
1975  * This was copied from __set_page_dirty_buffers which gives higher performance
1976  * in very high speed storages. (e.g., pmem)
1977  */
1978 void f2fs_set_page_dirty_nobuffers(struct page *page)
1979 {
1980 	struct address_space *mapping = page->mapping;
1981 	unsigned long flags;
1982 
1983 	if (unlikely(!mapping))
1984 		return;
1985 
1986 	spin_lock(&mapping->private_lock);
1987 	lock_page_memcg(page);
1988 	SetPageDirty(page);
1989 	spin_unlock(&mapping->private_lock);
1990 
1991 	spin_lock_irqsave(&mapping->tree_lock, flags);
1992 	WARN_ON_ONCE(!PageUptodate(page));
1993 	account_page_dirtied(page, mapping);
1994 	radix_tree_tag_set(&mapping->page_tree,
1995 			page_index(page), PAGECACHE_TAG_DIRTY);
1996 	spin_unlock_irqrestore(&mapping->tree_lock, flags);
1997 	unlock_page_memcg(page);
1998 
1999 	__mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
2000 	return;
2001 }
2002 
2003 static int f2fs_set_data_page_dirty(struct page *page)
2004 {
2005 	struct address_space *mapping = page->mapping;
2006 	struct inode *inode = mapping->host;
2007 
2008 	trace_f2fs_set_page_dirty(page, DATA);
2009 
2010 	if (!PageUptodate(page))
2011 		SetPageUptodate(page);
2012 
2013 	if (f2fs_is_atomic_file(inode) && !f2fs_is_commit_atomic_write(inode)) {
2014 		if (!IS_ATOMIC_WRITTEN_PAGE(page)) {
2015 			register_inmem_page(inode, page);
2016 			return 1;
2017 		}
2018 		/*
2019 		 * Previously, this page has been registered, we just
2020 		 * return here.
2021 		 */
2022 		return 0;
2023 	}
2024 
2025 	if (!PageDirty(page)) {
2026 		f2fs_set_page_dirty_nobuffers(page);
2027 		update_dirty_page(inode, page);
2028 		return 1;
2029 	}
2030 	return 0;
2031 }
2032 
2033 static sector_t f2fs_bmap(struct address_space *mapping, sector_t block)
2034 {
2035 	struct inode *inode = mapping->host;
2036 
2037 	if (f2fs_has_inline_data(inode))
2038 		return 0;
2039 
2040 	/* make sure allocating whole blocks */
2041 	if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
2042 		filemap_write_and_wait(mapping);
2043 
2044 	return generic_block_bmap(mapping, block, get_data_block_bmap);
2045 }
2046 
2047 #ifdef CONFIG_MIGRATION
2048 #include <linux/migrate.h>
2049 
2050 int f2fs_migrate_page(struct address_space *mapping,
2051 		struct page *newpage, struct page *page, enum migrate_mode mode)
2052 {
2053 	int rc, extra_count;
2054 	struct f2fs_inode_info *fi = F2FS_I(mapping->host);
2055 	bool atomic_written = IS_ATOMIC_WRITTEN_PAGE(page);
2056 
2057 	BUG_ON(PageWriteback(page));
2058 
2059 	/* migrating an atomic written page is safe with the inmem_lock hold */
2060 	if (atomic_written && !mutex_trylock(&fi->inmem_lock))
2061 		return -EAGAIN;
2062 
2063 	/*
2064 	 * A reference is expected if PagePrivate set when move mapping,
2065 	 * however F2FS breaks this for maintaining dirty page counts when
2066 	 * truncating pages. So here adjusting the 'extra_count' make it work.
2067 	 */
2068 	extra_count = (atomic_written ? 1 : 0) - page_has_private(page);
2069 	rc = migrate_page_move_mapping(mapping, newpage,
2070 				page, NULL, mode, extra_count);
2071 	if (rc != MIGRATEPAGE_SUCCESS) {
2072 		if (atomic_written)
2073 			mutex_unlock(&fi->inmem_lock);
2074 		return rc;
2075 	}
2076 
2077 	if (atomic_written) {
2078 		struct inmem_pages *cur;
2079 		list_for_each_entry(cur, &fi->inmem_pages, list)
2080 			if (cur->page == page) {
2081 				cur->page = newpage;
2082 				break;
2083 			}
2084 		mutex_unlock(&fi->inmem_lock);
2085 		put_page(page);
2086 		get_page(newpage);
2087 	}
2088 
2089 	if (PagePrivate(page))
2090 		SetPagePrivate(newpage);
2091 	set_page_private(newpage, page_private(page));
2092 
2093 	migrate_page_copy(newpage, page);
2094 
2095 	return MIGRATEPAGE_SUCCESS;
2096 }
2097 #endif
2098 
2099 const struct address_space_operations f2fs_dblock_aops = {
2100 	.readpage	= f2fs_read_data_page,
2101 	.readpages	= f2fs_read_data_pages,
2102 	.writepage	= f2fs_write_data_page,
2103 	.writepages	= f2fs_write_data_pages,
2104 	.write_begin	= f2fs_write_begin,
2105 	.write_end	= f2fs_write_end,
2106 	.set_page_dirty	= f2fs_set_data_page_dirty,
2107 	.invalidatepage	= f2fs_invalidate_page,
2108 	.releasepage	= f2fs_release_page,
2109 	.direct_IO	= f2fs_direct_IO,
2110 	.bmap		= f2fs_bmap,
2111 #ifdef CONFIG_MIGRATION
2112 	.migratepage    = f2fs_migrate_page,
2113 #endif
2114 };
2115