xref: /linux/fs/f2fs/data.c (revision 86a8280a7fe007d61b05fa8a352edc0595283dad)
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 			fscrypt_release_ctx(bio->bi_private);
38 		} else {
39 			fscrypt_decrypt_bio_pages(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 		fscrypt_pullback_bio_page(&page, true);
68 
69 		if (unlikely(bio->bi_error)) {
70 			set_bit(AS_EIO, &page->mapping->flags);
71 			f2fs_stop_checkpoint(sbi, true);
72 		}
73 		end_page_writeback(page);
74 	}
75 	if (atomic_dec_and_test(&sbi->nr_wb_bios) &&
76 				wq_has_sleeper(&sbi->cp_wait))
77 		wake_up(&sbi->cp_wait);
78 
79 	bio_put(bio);
80 }
81 
82 /*
83  * Low-level block read/write IO operations.
84  */
85 static struct bio *__bio_alloc(struct f2fs_sb_info *sbi, block_t blk_addr,
86 				int npages, bool is_read)
87 {
88 	struct bio *bio;
89 
90 	bio = f2fs_bio_alloc(npages);
91 
92 	bio->bi_bdev = sbi->sb->s_bdev;
93 	bio->bi_iter.bi_sector = SECTOR_FROM_BLOCK(blk_addr);
94 	bio->bi_end_io = is_read ? f2fs_read_end_io : f2fs_write_end_io;
95 	bio->bi_private = is_read ? NULL : sbi;
96 
97 	return bio;
98 }
99 
100 static inline void __submit_bio(struct f2fs_sb_info *sbi, int rw,
101 						struct bio *bio)
102 {
103 	if (!is_read_io(rw))
104 		atomic_inc(&sbi->nr_wb_bios);
105 	submit_bio(rw, bio);
106 }
107 
108 static void __submit_merged_bio(struct f2fs_bio_info *io)
109 {
110 	struct f2fs_io_info *fio = &io->fio;
111 
112 	if (!io->bio)
113 		return;
114 
115 	if (is_read_io(fio->rw))
116 		trace_f2fs_submit_read_bio(io->sbi->sb, fio, io->bio);
117 	else
118 		trace_f2fs_submit_write_bio(io->sbi->sb, fio, io->bio);
119 
120 	__submit_bio(io->sbi, fio->rw, io->bio);
121 	io->bio = NULL;
122 }
123 
124 static bool __has_merged_page(struct f2fs_bio_info *io, struct inode *inode,
125 						struct page *page, nid_t ino)
126 {
127 	struct bio_vec *bvec;
128 	struct page *target;
129 	int i;
130 
131 	if (!io->bio)
132 		return false;
133 
134 	if (!inode && !page && !ino)
135 		return true;
136 
137 	bio_for_each_segment_all(bvec, io->bio, i) {
138 
139 		if (bvec->bv_page->mapping)
140 			target = bvec->bv_page;
141 		else
142 			target = fscrypt_control_page(bvec->bv_page);
143 
144 		if (inode && inode == target->mapping->host)
145 			return true;
146 		if (page && page == target)
147 			return true;
148 		if (ino && ino == ino_of_node(target))
149 			return true;
150 	}
151 
152 	return false;
153 }
154 
155 static bool has_merged_page(struct f2fs_sb_info *sbi, struct inode *inode,
156 						struct page *page, nid_t ino,
157 						enum page_type type)
158 {
159 	enum page_type btype = PAGE_TYPE_OF_BIO(type);
160 	struct f2fs_bio_info *io = &sbi->write_io[btype];
161 	bool ret;
162 
163 	down_read(&io->io_rwsem);
164 	ret = __has_merged_page(io, inode, page, ino);
165 	up_read(&io->io_rwsem);
166 	return ret;
167 }
168 
169 static void __f2fs_submit_merged_bio(struct f2fs_sb_info *sbi,
170 				struct inode *inode, struct page *page,
171 				nid_t ino, enum page_type type, int rw)
172 {
173 	enum page_type btype = PAGE_TYPE_OF_BIO(type);
174 	struct f2fs_bio_info *io;
175 
176 	io = is_read_io(rw) ? &sbi->read_io : &sbi->write_io[btype];
177 
178 	down_write(&io->io_rwsem);
179 
180 	if (!__has_merged_page(io, inode, page, ino))
181 		goto out;
182 
183 	/* change META to META_FLUSH in the checkpoint procedure */
184 	if (type >= META_FLUSH) {
185 		io->fio.type = META_FLUSH;
186 		if (test_opt(sbi, NOBARRIER))
187 			io->fio.rw = WRITE_FLUSH | REQ_META | REQ_PRIO;
188 		else
189 			io->fio.rw = WRITE_FLUSH_FUA | REQ_META | REQ_PRIO;
190 	}
191 	__submit_merged_bio(io);
192 out:
193 	up_write(&io->io_rwsem);
194 }
195 
196 void f2fs_submit_merged_bio(struct f2fs_sb_info *sbi, enum page_type type,
197 									int rw)
198 {
199 	__f2fs_submit_merged_bio(sbi, NULL, NULL, 0, type, rw);
200 }
201 
202 void f2fs_submit_merged_bio_cond(struct f2fs_sb_info *sbi,
203 				struct inode *inode, struct page *page,
204 				nid_t ino, enum page_type type, int rw)
205 {
206 	if (has_merged_page(sbi, inode, page, ino, type))
207 		__f2fs_submit_merged_bio(sbi, inode, page, ino, type, rw);
208 }
209 
210 void f2fs_flush_merged_bios(struct f2fs_sb_info *sbi)
211 {
212 	f2fs_submit_merged_bio(sbi, DATA, WRITE);
213 	f2fs_submit_merged_bio(sbi, NODE, WRITE);
214 	f2fs_submit_merged_bio(sbi, META, WRITE);
215 }
216 
217 /*
218  * Fill the locked page with data located in the block address.
219  * Return unlocked page.
220  */
221 int f2fs_submit_page_bio(struct f2fs_io_info *fio)
222 {
223 	struct bio *bio;
224 	struct page *page = fio->encrypted_page ?
225 			fio->encrypted_page : fio->page;
226 
227 	trace_f2fs_submit_page_bio(page, fio);
228 	f2fs_trace_ios(fio, 0);
229 
230 	/* Allocate a new bio */
231 	bio = __bio_alloc(fio->sbi, fio->new_blkaddr, 1, is_read_io(fio->rw));
232 
233 	if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
234 		bio_put(bio);
235 		return -EFAULT;
236 	}
237 
238 	__submit_bio(fio->sbi, fio->rw, bio);
239 	return 0;
240 }
241 
242 void f2fs_submit_page_mbio(struct f2fs_io_info *fio)
243 {
244 	struct f2fs_sb_info *sbi = fio->sbi;
245 	enum page_type btype = PAGE_TYPE_OF_BIO(fio->type);
246 	struct f2fs_bio_info *io;
247 	bool is_read = is_read_io(fio->rw);
248 	struct page *bio_page;
249 
250 	io = is_read ? &sbi->read_io : &sbi->write_io[btype];
251 
252 	if (fio->old_blkaddr != NEW_ADDR)
253 		verify_block_addr(sbi, fio->old_blkaddr);
254 	verify_block_addr(sbi, fio->new_blkaddr);
255 
256 	down_write(&io->io_rwsem);
257 
258 	if (io->bio && (io->last_block_in_bio != fio->new_blkaddr - 1 ||
259 						io->fio.rw != fio->rw))
260 		__submit_merged_bio(io);
261 alloc_new:
262 	if (io->bio == NULL) {
263 		int bio_blocks = MAX_BIO_BLOCKS(sbi);
264 
265 		io->bio = __bio_alloc(sbi, fio->new_blkaddr,
266 						bio_blocks, is_read);
267 		io->fio = *fio;
268 	}
269 
270 	bio_page = fio->encrypted_page ? fio->encrypted_page : fio->page;
271 
272 	if (bio_add_page(io->bio, bio_page, PAGE_SIZE, 0) <
273 							PAGE_SIZE) {
274 		__submit_merged_bio(io);
275 		goto alloc_new;
276 	}
277 
278 	io->last_block_in_bio = fio->new_blkaddr;
279 	f2fs_trace_ios(fio, 0);
280 
281 	up_write(&io->io_rwsem);
282 	trace_f2fs_submit_page_mbio(fio->page, fio);
283 }
284 
285 static void __set_data_blkaddr(struct dnode_of_data *dn)
286 {
287 	struct f2fs_node *rn = F2FS_NODE(dn->node_page);
288 	__le32 *addr_array;
289 
290 	/* Get physical address of data block */
291 	addr_array = blkaddr_in_node(rn);
292 	addr_array[dn->ofs_in_node] = cpu_to_le32(dn->data_blkaddr);
293 }
294 
295 /*
296  * Lock ordering for the change of data block address:
297  * ->data_page
298  *  ->node_page
299  *    update block addresses in the node page
300  */
301 void set_data_blkaddr(struct dnode_of_data *dn)
302 {
303 	f2fs_wait_on_page_writeback(dn->node_page, NODE, true);
304 	__set_data_blkaddr(dn);
305 	if (set_page_dirty(dn->node_page))
306 		dn->node_changed = true;
307 }
308 
309 void f2fs_update_data_blkaddr(struct dnode_of_data *dn, block_t blkaddr)
310 {
311 	dn->data_blkaddr = blkaddr;
312 	set_data_blkaddr(dn);
313 	f2fs_update_extent_cache(dn);
314 }
315 
316 /* dn->ofs_in_node will be returned with up-to-date last block pointer */
317 int reserve_new_blocks(struct dnode_of_data *dn, blkcnt_t count)
318 {
319 	struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
320 
321 	if (!count)
322 		return 0;
323 
324 	if (unlikely(is_inode_flag_set(F2FS_I(dn->inode), FI_NO_ALLOC)))
325 		return -EPERM;
326 	if (unlikely(!inc_valid_block_count(sbi, dn->inode, &count)))
327 		return -ENOSPC;
328 
329 	trace_f2fs_reserve_new_blocks(dn->inode, dn->nid,
330 						dn->ofs_in_node, count);
331 
332 	f2fs_wait_on_page_writeback(dn->node_page, NODE, true);
333 
334 	for (; count > 0; dn->ofs_in_node++) {
335 		block_t blkaddr =
336 			datablock_addr(dn->node_page, dn->ofs_in_node);
337 		if (blkaddr == NULL_ADDR) {
338 			dn->data_blkaddr = NEW_ADDR;
339 			__set_data_blkaddr(dn);
340 			count--;
341 		}
342 	}
343 
344 	if (set_page_dirty(dn->node_page))
345 		dn->node_changed = true;
346 
347 	mark_inode_dirty(dn->inode);
348 	sync_inode_page(dn);
349 	return 0;
350 }
351 
352 /* Should keep dn->ofs_in_node unchanged */
353 int reserve_new_block(struct dnode_of_data *dn)
354 {
355 	unsigned int ofs_in_node = dn->ofs_in_node;
356 	int ret;
357 
358 	ret = reserve_new_blocks(dn, 1);
359 	dn->ofs_in_node = ofs_in_node;
360 	return ret;
361 }
362 
363 int f2fs_reserve_block(struct dnode_of_data *dn, pgoff_t index)
364 {
365 	bool need_put = dn->inode_page ? false : true;
366 	int err;
367 
368 	err = get_dnode_of_data(dn, index, ALLOC_NODE);
369 	if (err)
370 		return err;
371 
372 	if (dn->data_blkaddr == NULL_ADDR)
373 		err = reserve_new_block(dn);
374 	if (err || need_put)
375 		f2fs_put_dnode(dn);
376 	return err;
377 }
378 
379 int f2fs_get_block(struct dnode_of_data *dn, pgoff_t index)
380 {
381 	struct extent_info ei;
382 	struct inode *inode = dn->inode;
383 
384 	if (f2fs_lookup_extent_cache(inode, index, &ei)) {
385 		dn->data_blkaddr = ei.blk + index - ei.fofs;
386 		return 0;
387 	}
388 
389 	return f2fs_reserve_block(dn, index);
390 }
391 
392 struct page *get_read_data_page(struct inode *inode, pgoff_t index,
393 						int rw, bool for_write)
394 {
395 	struct address_space *mapping = inode->i_mapping;
396 	struct dnode_of_data dn;
397 	struct page *page;
398 	struct extent_info ei;
399 	int err;
400 	struct f2fs_io_info fio = {
401 		.sbi = F2FS_I_SB(inode),
402 		.type = DATA,
403 		.rw = rw,
404 		.encrypted_page = NULL,
405 	};
406 
407 	if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode))
408 		return read_mapping_page(mapping, index, NULL);
409 
410 	page = f2fs_grab_cache_page(mapping, index, for_write);
411 	if (!page)
412 		return ERR_PTR(-ENOMEM);
413 
414 	if (f2fs_lookup_extent_cache(inode, index, &ei)) {
415 		dn.data_blkaddr = ei.blk + index - ei.fofs;
416 		goto got_it;
417 	}
418 
419 	set_new_dnode(&dn, inode, NULL, NULL, 0);
420 	err = get_dnode_of_data(&dn, index, LOOKUP_NODE);
421 	if (err)
422 		goto put_err;
423 	f2fs_put_dnode(&dn);
424 
425 	if (unlikely(dn.data_blkaddr == NULL_ADDR)) {
426 		err = -ENOENT;
427 		goto put_err;
428 	}
429 got_it:
430 	if (PageUptodate(page)) {
431 		unlock_page(page);
432 		return page;
433 	}
434 
435 	/*
436 	 * A new dentry page is allocated but not able to be written, since its
437 	 * new inode page couldn't be allocated due to -ENOSPC.
438 	 * In such the case, its blkaddr can be remained as NEW_ADDR.
439 	 * see, f2fs_add_link -> get_new_data_page -> init_inode_metadata.
440 	 */
441 	if (dn.data_blkaddr == NEW_ADDR) {
442 		zero_user_segment(page, 0, PAGE_SIZE);
443 		SetPageUptodate(page);
444 		unlock_page(page);
445 		return page;
446 	}
447 
448 	fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
449 	fio.page = page;
450 	err = f2fs_submit_page_bio(&fio);
451 	if (err)
452 		goto put_err;
453 	return page;
454 
455 put_err:
456 	f2fs_put_page(page, 1);
457 	return ERR_PTR(err);
458 }
459 
460 struct page *find_data_page(struct inode *inode, pgoff_t index)
461 {
462 	struct address_space *mapping = inode->i_mapping;
463 	struct page *page;
464 
465 	page = find_get_page(mapping, index);
466 	if (page && PageUptodate(page))
467 		return page;
468 	f2fs_put_page(page, 0);
469 
470 	page = get_read_data_page(inode, index, READ_SYNC, false);
471 	if (IS_ERR(page))
472 		return page;
473 
474 	if (PageUptodate(page))
475 		return page;
476 
477 	wait_on_page_locked(page);
478 	if (unlikely(!PageUptodate(page))) {
479 		f2fs_put_page(page, 0);
480 		return ERR_PTR(-EIO);
481 	}
482 	return page;
483 }
484 
485 /*
486  * If it tries to access a hole, return an error.
487  * Because, the callers, functions in dir.c and GC, should be able to know
488  * whether this page exists or not.
489  */
490 struct page *get_lock_data_page(struct inode *inode, pgoff_t index,
491 							bool for_write)
492 {
493 	struct address_space *mapping = inode->i_mapping;
494 	struct page *page;
495 repeat:
496 	page = get_read_data_page(inode, index, READ_SYNC, for_write);
497 	if (IS_ERR(page))
498 		return page;
499 
500 	/* wait for read completion */
501 	lock_page(page);
502 	if (unlikely(!PageUptodate(page))) {
503 		f2fs_put_page(page, 1);
504 		return ERR_PTR(-EIO);
505 	}
506 	if (unlikely(page->mapping != mapping)) {
507 		f2fs_put_page(page, 1);
508 		goto repeat;
509 	}
510 	return page;
511 }
512 
513 /*
514  * Caller ensures that this data page is never allocated.
515  * A new zero-filled data page is allocated in the page cache.
516  *
517  * Also, caller should grab and release a rwsem by calling f2fs_lock_op() and
518  * f2fs_unlock_op().
519  * Note that, ipage is set only by make_empty_dir, and if any error occur,
520  * ipage should be released by this function.
521  */
522 struct page *get_new_data_page(struct inode *inode,
523 		struct page *ipage, pgoff_t index, bool new_i_size)
524 {
525 	struct address_space *mapping = inode->i_mapping;
526 	struct page *page;
527 	struct dnode_of_data dn;
528 	int err;
529 
530 	page = f2fs_grab_cache_page(mapping, index, true);
531 	if (!page) {
532 		/*
533 		 * before exiting, we should make sure ipage will be released
534 		 * if any error occur.
535 		 */
536 		f2fs_put_page(ipage, 1);
537 		return ERR_PTR(-ENOMEM);
538 	}
539 
540 	set_new_dnode(&dn, inode, ipage, NULL, 0);
541 	err = f2fs_reserve_block(&dn, index);
542 	if (err) {
543 		f2fs_put_page(page, 1);
544 		return ERR_PTR(err);
545 	}
546 	if (!ipage)
547 		f2fs_put_dnode(&dn);
548 
549 	if (PageUptodate(page))
550 		goto got_it;
551 
552 	if (dn.data_blkaddr == NEW_ADDR) {
553 		zero_user_segment(page, 0, PAGE_SIZE);
554 		SetPageUptodate(page);
555 	} else {
556 		f2fs_put_page(page, 1);
557 
558 		/* if ipage exists, blkaddr should be NEW_ADDR */
559 		f2fs_bug_on(F2FS_I_SB(inode), ipage);
560 		page = get_lock_data_page(inode, index, true);
561 		if (IS_ERR(page))
562 			return page;
563 	}
564 got_it:
565 	if (new_i_size && i_size_read(inode) <
566 				((loff_t)(index + 1) << PAGE_SHIFT)) {
567 		i_size_write(inode, ((loff_t)(index + 1) << PAGE_SHIFT));
568 		/* Only the directory inode sets new_i_size */
569 		set_inode_flag(F2FS_I(inode), FI_UPDATE_DIR);
570 	}
571 	return page;
572 }
573 
574 static int __allocate_data_block(struct dnode_of_data *dn)
575 {
576 	struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
577 	struct f2fs_summary sum;
578 	struct node_info ni;
579 	int seg = CURSEG_WARM_DATA;
580 	pgoff_t fofs;
581 	blkcnt_t count = 1;
582 
583 	if (unlikely(is_inode_flag_set(F2FS_I(dn->inode), FI_NO_ALLOC)))
584 		return -EPERM;
585 
586 	dn->data_blkaddr = datablock_addr(dn->node_page, dn->ofs_in_node);
587 	if (dn->data_blkaddr == NEW_ADDR)
588 		goto alloc;
589 
590 	if (unlikely(!inc_valid_block_count(sbi, dn->inode, &count)))
591 		return -ENOSPC;
592 
593 alloc:
594 	get_node_info(sbi, dn->nid, &ni);
595 	set_summary(&sum, dn->nid, dn->ofs_in_node, ni.version);
596 
597 	if (dn->ofs_in_node == 0 && dn->inode_page == dn->node_page)
598 		seg = CURSEG_DIRECT_IO;
599 
600 	allocate_data_block(sbi, NULL, dn->data_blkaddr, &dn->data_blkaddr,
601 								&sum, seg);
602 	set_data_blkaddr(dn);
603 
604 	/* update i_size */
605 	fofs = start_bidx_of_node(ofs_of_node(dn->node_page), dn->inode) +
606 							dn->ofs_in_node;
607 	if (i_size_read(dn->inode) < ((loff_t)(fofs + 1) << PAGE_SHIFT))
608 		i_size_write(dn->inode,
609 				((loff_t)(fofs + 1) << PAGE_SHIFT));
610 	return 0;
611 }
612 
613 ssize_t f2fs_preallocate_blocks(struct kiocb *iocb, struct iov_iter *from)
614 {
615 	struct inode *inode = file_inode(iocb->ki_filp);
616 	struct f2fs_map_blocks map;
617 	ssize_t ret = 0;
618 
619 	map.m_lblk = F2FS_BLK_ALIGN(iocb->ki_pos);
620 	map.m_len = F2FS_BYTES_TO_BLK(iov_iter_count(from));
621 	map.m_next_pgofs = NULL;
622 
623 	if (f2fs_encrypted_inode(inode))
624 		return 0;
625 
626 	if (iocb->ki_flags & IOCB_DIRECT) {
627 		ret = f2fs_convert_inline_inode(inode);
628 		if (ret)
629 			return ret;
630 		return f2fs_map_blocks(inode, &map, 1, F2FS_GET_BLOCK_PRE_DIO);
631 	}
632 	if (iocb->ki_pos + iov_iter_count(from) > MAX_INLINE_DATA) {
633 		ret = f2fs_convert_inline_inode(inode);
634 		if (ret)
635 			return ret;
636 	}
637 	if (!f2fs_has_inline_data(inode))
638 		return f2fs_map_blocks(inode, &map, 1, F2FS_GET_BLOCK_PRE_AIO);
639 	return ret;
640 }
641 
642 /*
643  * f2fs_map_blocks() now supported readahead/bmap/rw direct_IO with
644  * f2fs_map_blocks structure.
645  * If original data blocks are allocated, then give them to blockdev.
646  * Otherwise,
647  *     a. preallocate requested block addresses
648  *     b. do not use extent cache for better performance
649  *     c. give the block addresses to blockdev
650  */
651 int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map,
652 						int create, int flag)
653 {
654 	unsigned int maxblocks = map->m_len;
655 	struct dnode_of_data dn;
656 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
657 	int mode = create ? ALLOC_NODE : LOOKUP_NODE_RA;
658 	pgoff_t pgofs, end_offset, end;
659 	int err = 0, ofs = 1;
660 	unsigned int ofs_in_node, last_ofs_in_node;
661 	blkcnt_t prealloc;
662 	struct extent_info ei;
663 	bool allocated = false;
664 	block_t blkaddr;
665 
666 	map->m_len = 0;
667 	map->m_flags = 0;
668 
669 	/* it only supports block size == page size */
670 	pgofs =	(pgoff_t)map->m_lblk;
671 	end = pgofs + maxblocks;
672 
673 	if (!create && f2fs_lookup_extent_cache(inode, pgofs, &ei)) {
674 		map->m_pblk = ei.blk + pgofs - ei.fofs;
675 		map->m_len = min((pgoff_t)maxblocks, ei.fofs + ei.len - pgofs);
676 		map->m_flags = F2FS_MAP_MAPPED;
677 		goto out;
678 	}
679 
680 next_dnode:
681 	if (create)
682 		f2fs_lock_op(sbi);
683 
684 	/* When reading holes, we need its node page */
685 	set_new_dnode(&dn, inode, NULL, NULL, 0);
686 	err = get_dnode_of_data(&dn, pgofs, mode);
687 	if (err) {
688 		if (flag == F2FS_GET_BLOCK_BMAP)
689 			map->m_pblk = 0;
690 		if (err == -ENOENT) {
691 			err = 0;
692 			if (map->m_next_pgofs)
693 				*map->m_next_pgofs =
694 					get_next_page_offset(&dn, pgofs);
695 		}
696 		goto unlock_out;
697 	}
698 
699 	prealloc = 0;
700 	ofs_in_node = dn.ofs_in_node;
701 	end_offset = ADDRS_PER_PAGE(dn.node_page, inode);
702 
703 next_block:
704 	blkaddr = datablock_addr(dn.node_page, dn.ofs_in_node);
705 
706 	if (blkaddr == NEW_ADDR || blkaddr == NULL_ADDR) {
707 		if (create) {
708 			if (unlikely(f2fs_cp_error(sbi))) {
709 				err = -EIO;
710 				goto sync_out;
711 			}
712 			if (flag == F2FS_GET_BLOCK_PRE_AIO) {
713 				if (blkaddr == NULL_ADDR) {
714 					prealloc++;
715 					last_ofs_in_node = dn.ofs_in_node;
716 				}
717 			} else {
718 				err = __allocate_data_block(&dn);
719 				if (!err) {
720 					set_inode_flag(F2FS_I(inode),
721 							FI_APPEND_WRITE);
722 					allocated = true;
723 				}
724 			}
725 			if (err)
726 				goto sync_out;
727 			map->m_flags = F2FS_MAP_NEW;
728 			blkaddr = dn.data_blkaddr;
729 		} else {
730 			if (flag == F2FS_GET_BLOCK_BMAP) {
731 				map->m_pblk = 0;
732 				goto sync_out;
733 			}
734 			if (flag == F2FS_GET_BLOCK_FIEMAP &&
735 						blkaddr == NULL_ADDR) {
736 				if (map->m_next_pgofs)
737 					*map->m_next_pgofs = pgofs + 1;
738 			}
739 			if (flag != F2FS_GET_BLOCK_FIEMAP ||
740 						blkaddr != NEW_ADDR)
741 				goto sync_out;
742 		}
743 	}
744 
745 	if (flag == F2FS_GET_BLOCK_PRE_AIO)
746 		goto skip;
747 
748 	if (map->m_len == 0) {
749 		/* preallocated unwritten block should be mapped for fiemap. */
750 		if (blkaddr == NEW_ADDR)
751 			map->m_flags |= F2FS_MAP_UNWRITTEN;
752 		map->m_flags |= F2FS_MAP_MAPPED;
753 
754 		map->m_pblk = blkaddr;
755 		map->m_len = 1;
756 	} else if ((map->m_pblk != NEW_ADDR &&
757 			blkaddr == (map->m_pblk + ofs)) ||
758 			(map->m_pblk == NEW_ADDR && blkaddr == NEW_ADDR) ||
759 			flag == F2FS_GET_BLOCK_PRE_DIO) {
760 		ofs++;
761 		map->m_len++;
762 	} else {
763 		goto sync_out;
764 	}
765 
766 skip:
767 	dn.ofs_in_node++;
768 	pgofs++;
769 
770 	/* preallocate blocks in batch for one dnode page */
771 	if (flag == F2FS_GET_BLOCK_PRE_AIO &&
772 			(pgofs == end || dn.ofs_in_node == end_offset)) {
773 
774 		dn.ofs_in_node = ofs_in_node;
775 		err = reserve_new_blocks(&dn, prealloc);
776 		if (err)
777 			goto sync_out;
778 
779 		map->m_len += dn.ofs_in_node - ofs_in_node;
780 		if (prealloc && dn.ofs_in_node != last_ofs_in_node + 1) {
781 			err = -ENOSPC;
782 			goto sync_out;
783 		}
784 		dn.ofs_in_node = end_offset;
785 	}
786 
787 	if (pgofs >= end)
788 		goto sync_out;
789 	else if (dn.ofs_in_node < end_offset)
790 		goto next_block;
791 
792 	if (allocated)
793 		sync_inode_page(&dn);
794 	f2fs_put_dnode(&dn);
795 
796 	if (create) {
797 		f2fs_unlock_op(sbi);
798 		f2fs_balance_fs(sbi, allocated);
799 	}
800 	allocated = false;
801 	goto next_dnode;
802 
803 sync_out:
804 	if (allocated)
805 		sync_inode_page(&dn);
806 	f2fs_put_dnode(&dn);
807 unlock_out:
808 	if (create) {
809 		f2fs_unlock_op(sbi);
810 		f2fs_balance_fs(sbi, allocated);
811 	}
812 out:
813 	trace_f2fs_map_blocks(inode, map, err);
814 	return err;
815 }
816 
817 static int __get_data_block(struct inode *inode, sector_t iblock,
818 			struct buffer_head *bh, int create, int flag,
819 			pgoff_t *next_pgofs)
820 {
821 	struct f2fs_map_blocks map;
822 	int ret;
823 
824 	map.m_lblk = iblock;
825 	map.m_len = bh->b_size >> inode->i_blkbits;
826 	map.m_next_pgofs = next_pgofs;
827 
828 	ret = f2fs_map_blocks(inode, &map, create, flag);
829 	if (!ret) {
830 		map_bh(bh, inode->i_sb, map.m_pblk);
831 		bh->b_state = (bh->b_state & ~F2FS_MAP_FLAGS) | map.m_flags;
832 		bh->b_size = map.m_len << inode->i_blkbits;
833 	}
834 	return ret;
835 }
836 
837 static int get_data_block(struct inode *inode, sector_t iblock,
838 			struct buffer_head *bh_result, int create, int flag,
839 			pgoff_t *next_pgofs)
840 {
841 	return __get_data_block(inode, iblock, bh_result, create,
842 							flag, next_pgofs);
843 }
844 
845 static int get_data_block_dio(struct inode *inode, sector_t iblock,
846 			struct buffer_head *bh_result, int create)
847 {
848 	return __get_data_block(inode, iblock, bh_result, create,
849 						F2FS_GET_BLOCK_DIO, NULL);
850 }
851 
852 static int get_data_block_bmap(struct inode *inode, sector_t iblock,
853 			struct buffer_head *bh_result, int create)
854 {
855 	/* Block number less than F2FS MAX BLOCKS */
856 	if (unlikely(iblock >= F2FS_I_SB(inode)->max_file_blocks))
857 		return -EFBIG;
858 
859 	return __get_data_block(inode, iblock, bh_result, create,
860 						F2FS_GET_BLOCK_BMAP, NULL);
861 }
862 
863 static inline sector_t logical_to_blk(struct inode *inode, loff_t offset)
864 {
865 	return (offset >> inode->i_blkbits);
866 }
867 
868 static inline loff_t blk_to_logical(struct inode *inode, sector_t blk)
869 {
870 	return (blk << inode->i_blkbits);
871 }
872 
873 int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
874 		u64 start, u64 len)
875 {
876 	struct buffer_head map_bh;
877 	sector_t start_blk, last_blk;
878 	pgoff_t next_pgofs;
879 	loff_t isize;
880 	u64 logical = 0, phys = 0, size = 0;
881 	u32 flags = 0;
882 	int ret = 0;
883 
884 	ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC);
885 	if (ret)
886 		return ret;
887 
888 	if (f2fs_has_inline_data(inode)) {
889 		ret = f2fs_inline_data_fiemap(inode, fieinfo, start, len);
890 		if (ret != -EAGAIN)
891 			return ret;
892 	}
893 
894 	inode_lock(inode);
895 
896 	isize = i_size_read(inode);
897 	if (start >= isize)
898 		goto out;
899 
900 	if (start + len > isize)
901 		len = isize - start;
902 
903 	if (logical_to_blk(inode, len) == 0)
904 		len = blk_to_logical(inode, 1);
905 
906 	start_blk = logical_to_blk(inode, start);
907 	last_blk = logical_to_blk(inode, start + len - 1);
908 
909 next:
910 	memset(&map_bh, 0, sizeof(struct buffer_head));
911 	map_bh.b_size = len;
912 
913 	ret = get_data_block(inode, start_blk, &map_bh, 0,
914 					F2FS_GET_BLOCK_FIEMAP, &next_pgofs);
915 	if (ret)
916 		goto out;
917 
918 	/* HOLE */
919 	if (!buffer_mapped(&map_bh)) {
920 		start_blk = next_pgofs;
921 		/* Go through holes util pass the EOF */
922 		if (blk_to_logical(inode, start_blk) < isize)
923 			goto prep_next;
924 		/* Found a hole beyond isize means no more extents.
925 		 * Note that the premise is that filesystems don't
926 		 * punch holes beyond isize and keep size unchanged.
927 		 */
928 		flags |= FIEMAP_EXTENT_LAST;
929 	}
930 
931 	if (size) {
932 		if (f2fs_encrypted_inode(inode))
933 			flags |= FIEMAP_EXTENT_DATA_ENCRYPTED;
934 
935 		ret = fiemap_fill_next_extent(fieinfo, logical,
936 				phys, size, flags);
937 	}
938 
939 	if (start_blk > last_blk || ret)
940 		goto out;
941 
942 	logical = blk_to_logical(inode, start_blk);
943 	phys = blk_to_logical(inode, map_bh.b_blocknr);
944 	size = map_bh.b_size;
945 	flags = 0;
946 	if (buffer_unwritten(&map_bh))
947 		flags = FIEMAP_EXTENT_UNWRITTEN;
948 
949 	start_blk += logical_to_blk(inode, size);
950 
951 prep_next:
952 	cond_resched();
953 	if (fatal_signal_pending(current))
954 		ret = -EINTR;
955 	else
956 		goto next;
957 out:
958 	if (ret == 1)
959 		ret = 0;
960 
961 	inode_unlock(inode);
962 	return ret;
963 }
964 
965 /*
966  * This function was originally taken from fs/mpage.c, and customized for f2fs.
967  * Major change was from block_size == page_size in f2fs by default.
968  */
969 static int f2fs_mpage_readpages(struct address_space *mapping,
970 			struct list_head *pages, struct page *page,
971 			unsigned nr_pages)
972 {
973 	struct bio *bio = NULL;
974 	unsigned page_idx;
975 	sector_t last_block_in_bio = 0;
976 	struct inode *inode = mapping->host;
977 	const unsigned blkbits = inode->i_blkbits;
978 	const unsigned blocksize = 1 << blkbits;
979 	sector_t block_in_file;
980 	sector_t last_block;
981 	sector_t last_block_in_file;
982 	sector_t block_nr;
983 	struct block_device *bdev = inode->i_sb->s_bdev;
984 	struct f2fs_map_blocks map;
985 
986 	map.m_pblk = 0;
987 	map.m_lblk = 0;
988 	map.m_len = 0;
989 	map.m_flags = 0;
990 	map.m_next_pgofs = NULL;
991 
992 	for (page_idx = 0; nr_pages; page_idx++, nr_pages--) {
993 
994 		prefetchw(&page->flags);
995 		if (pages) {
996 			page = list_entry(pages->prev, struct page, lru);
997 			list_del(&page->lru);
998 			if (add_to_page_cache_lru(page, mapping,
999 						  page->index, GFP_KERNEL))
1000 				goto next_page;
1001 		}
1002 
1003 		block_in_file = (sector_t)page->index;
1004 		last_block = block_in_file + nr_pages;
1005 		last_block_in_file = (i_size_read(inode) + blocksize - 1) >>
1006 								blkbits;
1007 		if (last_block > last_block_in_file)
1008 			last_block = last_block_in_file;
1009 
1010 		/*
1011 		 * Map blocks using the previous result first.
1012 		 */
1013 		if ((map.m_flags & F2FS_MAP_MAPPED) &&
1014 				block_in_file > map.m_lblk &&
1015 				block_in_file < (map.m_lblk + map.m_len))
1016 			goto got_it;
1017 
1018 		/*
1019 		 * Then do more f2fs_map_blocks() calls until we are
1020 		 * done with this page.
1021 		 */
1022 		map.m_flags = 0;
1023 
1024 		if (block_in_file < last_block) {
1025 			map.m_lblk = block_in_file;
1026 			map.m_len = last_block - block_in_file;
1027 
1028 			if (f2fs_map_blocks(inode, &map, 0,
1029 						F2FS_GET_BLOCK_READ))
1030 				goto set_error_page;
1031 		}
1032 got_it:
1033 		if ((map.m_flags & F2FS_MAP_MAPPED)) {
1034 			block_nr = map.m_pblk + block_in_file - map.m_lblk;
1035 			SetPageMappedToDisk(page);
1036 
1037 			if (!PageUptodate(page) && !cleancache_get_page(page)) {
1038 				SetPageUptodate(page);
1039 				goto confused;
1040 			}
1041 		} else {
1042 			zero_user_segment(page, 0, PAGE_SIZE);
1043 			SetPageUptodate(page);
1044 			unlock_page(page);
1045 			goto next_page;
1046 		}
1047 
1048 		/*
1049 		 * This page will go to BIO.  Do we need to send this
1050 		 * BIO off first?
1051 		 */
1052 		if (bio && (last_block_in_bio != block_nr - 1)) {
1053 submit_and_realloc:
1054 			__submit_bio(F2FS_I_SB(inode), READ, bio);
1055 			bio = NULL;
1056 		}
1057 		if (bio == NULL) {
1058 			struct fscrypt_ctx *ctx = NULL;
1059 
1060 			if (f2fs_encrypted_inode(inode) &&
1061 					S_ISREG(inode->i_mode)) {
1062 
1063 				ctx = fscrypt_get_ctx(inode, GFP_NOFS);
1064 				if (IS_ERR(ctx))
1065 					goto set_error_page;
1066 
1067 				/* wait the page to be moved by cleaning */
1068 				f2fs_wait_on_encrypted_page_writeback(
1069 						F2FS_I_SB(inode), block_nr);
1070 			}
1071 
1072 			bio = bio_alloc(GFP_KERNEL,
1073 				min_t(int, nr_pages, BIO_MAX_PAGES));
1074 			if (!bio) {
1075 				if (ctx)
1076 					fscrypt_release_ctx(ctx);
1077 				goto set_error_page;
1078 			}
1079 			bio->bi_bdev = bdev;
1080 			bio->bi_iter.bi_sector = SECTOR_FROM_BLOCK(block_nr);
1081 			bio->bi_end_io = f2fs_read_end_io;
1082 			bio->bi_private = ctx;
1083 		}
1084 
1085 		if (bio_add_page(bio, page, blocksize, 0) < blocksize)
1086 			goto submit_and_realloc;
1087 
1088 		last_block_in_bio = block_nr;
1089 		goto next_page;
1090 set_error_page:
1091 		SetPageError(page);
1092 		zero_user_segment(page, 0, PAGE_SIZE);
1093 		unlock_page(page);
1094 		goto next_page;
1095 confused:
1096 		if (bio) {
1097 			__submit_bio(F2FS_I_SB(inode), READ, bio);
1098 			bio = NULL;
1099 		}
1100 		unlock_page(page);
1101 next_page:
1102 		if (pages)
1103 			put_page(page);
1104 	}
1105 	BUG_ON(pages && !list_empty(pages));
1106 	if (bio)
1107 		__submit_bio(F2FS_I_SB(inode), READ, bio);
1108 	return 0;
1109 }
1110 
1111 static int f2fs_read_data_page(struct file *file, struct page *page)
1112 {
1113 	struct inode *inode = page->mapping->host;
1114 	int ret = -EAGAIN;
1115 
1116 	trace_f2fs_readpage(page, DATA);
1117 
1118 	/* If the file has inline data, try to read it directly */
1119 	if (f2fs_has_inline_data(inode))
1120 		ret = f2fs_read_inline_data(inode, page);
1121 	if (ret == -EAGAIN)
1122 		ret = f2fs_mpage_readpages(page->mapping, NULL, page, 1);
1123 	return ret;
1124 }
1125 
1126 static int f2fs_read_data_pages(struct file *file,
1127 			struct address_space *mapping,
1128 			struct list_head *pages, unsigned nr_pages)
1129 {
1130 	struct inode *inode = file->f_mapping->host;
1131 	struct page *page = list_entry(pages->prev, struct page, lru);
1132 
1133 	trace_f2fs_readpages(inode, page, nr_pages);
1134 
1135 	/* If the file has inline data, skip readpages */
1136 	if (f2fs_has_inline_data(inode))
1137 		return 0;
1138 
1139 	return f2fs_mpage_readpages(mapping, pages, NULL, nr_pages);
1140 }
1141 
1142 int do_write_data_page(struct f2fs_io_info *fio)
1143 {
1144 	struct page *page = fio->page;
1145 	struct inode *inode = page->mapping->host;
1146 	struct dnode_of_data dn;
1147 	int err = 0;
1148 
1149 	set_new_dnode(&dn, inode, NULL, NULL, 0);
1150 	err = get_dnode_of_data(&dn, page->index, LOOKUP_NODE);
1151 	if (err)
1152 		return err;
1153 
1154 	fio->old_blkaddr = dn.data_blkaddr;
1155 
1156 	/* This page is already truncated */
1157 	if (fio->old_blkaddr == NULL_ADDR) {
1158 		ClearPageUptodate(page);
1159 		goto out_writepage;
1160 	}
1161 
1162 	if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode)) {
1163 		gfp_t gfp_flags = GFP_NOFS;
1164 
1165 		/* wait for GCed encrypted page writeback */
1166 		f2fs_wait_on_encrypted_page_writeback(F2FS_I_SB(inode),
1167 							fio->old_blkaddr);
1168 retry_encrypt:
1169 		fio->encrypted_page = fscrypt_encrypt_page(inode, fio->page,
1170 								gfp_flags);
1171 		if (IS_ERR(fio->encrypted_page)) {
1172 			err = PTR_ERR(fio->encrypted_page);
1173 			if (err == -ENOMEM) {
1174 				/* flush pending ios and wait for a while */
1175 				f2fs_flush_merged_bios(F2FS_I_SB(inode));
1176 				congestion_wait(BLK_RW_ASYNC, HZ/50);
1177 				gfp_flags |= __GFP_NOFAIL;
1178 				err = 0;
1179 				goto retry_encrypt;
1180 			}
1181 			goto out_writepage;
1182 		}
1183 	}
1184 
1185 	set_page_writeback(page);
1186 
1187 	/*
1188 	 * If current allocation needs SSR,
1189 	 * it had better in-place writes for updated data.
1190 	 */
1191 	if (unlikely(fio->old_blkaddr != NEW_ADDR &&
1192 			!is_cold_data(page) &&
1193 			!IS_ATOMIC_WRITTEN_PAGE(page) &&
1194 			need_inplace_update(inode))) {
1195 		rewrite_data_page(fio);
1196 		set_inode_flag(F2FS_I(inode), FI_UPDATE_WRITE);
1197 		trace_f2fs_do_write_data_page(page, IPU);
1198 	} else {
1199 		write_data_page(&dn, fio);
1200 		trace_f2fs_do_write_data_page(page, OPU);
1201 		set_inode_flag(F2FS_I(inode), FI_APPEND_WRITE);
1202 		if (page->index == 0)
1203 			set_inode_flag(F2FS_I(inode), FI_FIRST_BLOCK_WRITTEN);
1204 	}
1205 out_writepage:
1206 	f2fs_put_dnode(&dn);
1207 	return err;
1208 }
1209 
1210 static int f2fs_write_data_page(struct page *page,
1211 					struct writeback_control *wbc)
1212 {
1213 	struct inode *inode = page->mapping->host;
1214 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1215 	loff_t i_size = i_size_read(inode);
1216 	const pgoff_t end_index = ((unsigned long long) i_size)
1217 							>> PAGE_SHIFT;
1218 	unsigned offset = 0;
1219 	bool need_balance_fs = false;
1220 	int err = 0;
1221 	struct f2fs_io_info fio = {
1222 		.sbi = sbi,
1223 		.type = DATA,
1224 		.rw = (wbc->sync_mode == WB_SYNC_ALL) ? WRITE_SYNC : WRITE,
1225 		.page = page,
1226 		.encrypted_page = NULL,
1227 	};
1228 
1229 	trace_f2fs_writepage(page, DATA);
1230 
1231 	if (page->index < end_index)
1232 		goto write;
1233 
1234 	/*
1235 	 * If the offset is out-of-range of file size,
1236 	 * this page does not have to be written to disk.
1237 	 */
1238 	offset = i_size & (PAGE_SIZE - 1);
1239 	if ((page->index >= end_index + 1) || !offset)
1240 		goto out;
1241 
1242 	zero_user_segment(page, offset, PAGE_SIZE);
1243 write:
1244 	if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
1245 		goto redirty_out;
1246 	if (f2fs_is_drop_cache(inode))
1247 		goto out;
1248 	/* we should not write 0'th page having journal header */
1249 	if (f2fs_is_volatile_file(inode) && (!page->index ||
1250 			(!wbc->for_reclaim &&
1251 			available_free_memory(sbi, BASE_CHECK))))
1252 		goto redirty_out;
1253 
1254 	/* Dentry blocks are controlled by checkpoint */
1255 	if (S_ISDIR(inode->i_mode)) {
1256 		if (unlikely(f2fs_cp_error(sbi)))
1257 			goto redirty_out;
1258 		err = do_write_data_page(&fio);
1259 		goto done;
1260 	}
1261 
1262 	/* we should bypass data pages to proceed the kworkder jobs */
1263 	if (unlikely(f2fs_cp_error(sbi))) {
1264 		SetPageError(page);
1265 		goto out;
1266 	}
1267 
1268 	if (!wbc->for_reclaim)
1269 		need_balance_fs = true;
1270 	else if (has_not_enough_free_secs(sbi, 0))
1271 		goto redirty_out;
1272 
1273 	err = -EAGAIN;
1274 	f2fs_lock_op(sbi);
1275 	if (f2fs_has_inline_data(inode))
1276 		err = f2fs_write_inline_data(inode, page);
1277 	if (err == -EAGAIN)
1278 		err = do_write_data_page(&fio);
1279 	f2fs_unlock_op(sbi);
1280 done:
1281 	if (err && err != -ENOENT)
1282 		goto redirty_out;
1283 
1284 	clear_cold_data(page);
1285 out:
1286 	inode_dec_dirty_pages(inode);
1287 	if (err)
1288 		ClearPageUptodate(page);
1289 
1290 	if (wbc->for_reclaim) {
1291 		f2fs_submit_merged_bio_cond(sbi, NULL, page, 0, DATA, WRITE);
1292 		remove_dirty_inode(inode);
1293 	}
1294 
1295 	unlock_page(page);
1296 	f2fs_balance_fs(sbi, need_balance_fs);
1297 
1298 	if (unlikely(f2fs_cp_error(sbi)))
1299 		f2fs_submit_merged_bio(sbi, DATA, WRITE);
1300 
1301 	return 0;
1302 
1303 redirty_out:
1304 	redirty_page_for_writepage(wbc, page);
1305 	return AOP_WRITEPAGE_ACTIVATE;
1306 }
1307 
1308 static int __f2fs_writepage(struct page *page, struct writeback_control *wbc,
1309 			void *data)
1310 {
1311 	struct address_space *mapping = data;
1312 	int ret = mapping->a_ops->writepage(page, wbc);
1313 	mapping_set_error(mapping, ret);
1314 	return ret;
1315 }
1316 
1317 /*
1318  * This function was copied from write_cche_pages from mm/page-writeback.c.
1319  * The major change is making write step of cold data page separately from
1320  * warm/hot data page.
1321  */
1322 static int f2fs_write_cache_pages(struct address_space *mapping,
1323 			struct writeback_control *wbc, writepage_t writepage,
1324 			void *data)
1325 {
1326 	int ret = 0;
1327 	int done = 0;
1328 	struct pagevec pvec;
1329 	int nr_pages;
1330 	pgoff_t uninitialized_var(writeback_index);
1331 	pgoff_t index;
1332 	pgoff_t end;		/* Inclusive */
1333 	pgoff_t done_index;
1334 	int cycled;
1335 	int range_whole = 0;
1336 	int tag;
1337 	int step = 0;
1338 
1339 	pagevec_init(&pvec, 0);
1340 next:
1341 	if (wbc->range_cyclic) {
1342 		writeback_index = mapping->writeback_index; /* prev offset */
1343 		index = writeback_index;
1344 		if (index == 0)
1345 			cycled = 1;
1346 		else
1347 			cycled = 0;
1348 		end = -1;
1349 	} else {
1350 		index = wbc->range_start >> PAGE_SHIFT;
1351 		end = wbc->range_end >> PAGE_SHIFT;
1352 		if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
1353 			range_whole = 1;
1354 		cycled = 1; /* ignore range_cyclic tests */
1355 	}
1356 	if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
1357 		tag = PAGECACHE_TAG_TOWRITE;
1358 	else
1359 		tag = PAGECACHE_TAG_DIRTY;
1360 retry:
1361 	if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
1362 		tag_pages_for_writeback(mapping, index, end);
1363 	done_index = index;
1364 	while (!done && (index <= end)) {
1365 		int i;
1366 
1367 		nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
1368 			      min(end - index, (pgoff_t)PAGEVEC_SIZE - 1) + 1);
1369 		if (nr_pages == 0)
1370 			break;
1371 
1372 		for (i = 0; i < nr_pages; i++) {
1373 			struct page *page = pvec.pages[i];
1374 
1375 			if (page->index > end) {
1376 				done = 1;
1377 				break;
1378 			}
1379 
1380 			done_index = page->index;
1381 
1382 			lock_page(page);
1383 
1384 			if (unlikely(page->mapping != mapping)) {
1385 continue_unlock:
1386 				unlock_page(page);
1387 				continue;
1388 			}
1389 
1390 			if (!PageDirty(page)) {
1391 				/* someone wrote it for us */
1392 				goto continue_unlock;
1393 			}
1394 
1395 			if (step == is_cold_data(page))
1396 				goto continue_unlock;
1397 
1398 			if (PageWriteback(page)) {
1399 				if (wbc->sync_mode != WB_SYNC_NONE)
1400 					f2fs_wait_on_page_writeback(page,
1401 								DATA, true);
1402 				else
1403 					goto continue_unlock;
1404 			}
1405 
1406 			BUG_ON(PageWriteback(page));
1407 			if (!clear_page_dirty_for_io(page))
1408 				goto continue_unlock;
1409 
1410 			ret = (*writepage)(page, wbc, data);
1411 			if (unlikely(ret)) {
1412 				if (ret == AOP_WRITEPAGE_ACTIVATE) {
1413 					unlock_page(page);
1414 					ret = 0;
1415 				} else {
1416 					done_index = page->index + 1;
1417 					done = 1;
1418 					break;
1419 				}
1420 			}
1421 
1422 			if (--wbc->nr_to_write <= 0 &&
1423 			    wbc->sync_mode == WB_SYNC_NONE) {
1424 				done = 1;
1425 				break;
1426 			}
1427 		}
1428 		pagevec_release(&pvec);
1429 		cond_resched();
1430 	}
1431 
1432 	if (step < 1) {
1433 		step++;
1434 		goto next;
1435 	}
1436 
1437 	if (!cycled && !done) {
1438 		cycled = 1;
1439 		index = 0;
1440 		end = writeback_index - 1;
1441 		goto retry;
1442 	}
1443 	if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
1444 		mapping->writeback_index = done_index;
1445 
1446 	return ret;
1447 }
1448 
1449 static int f2fs_write_data_pages(struct address_space *mapping,
1450 			    struct writeback_control *wbc)
1451 {
1452 	struct inode *inode = mapping->host;
1453 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1454 	bool locked = false;
1455 	int ret;
1456 	long diff;
1457 
1458 	/* deal with chardevs and other special file */
1459 	if (!mapping->a_ops->writepage)
1460 		return 0;
1461 
1462 	/* skip writing if there is no dirty page in this inode */
1463 	if (!get_dirty_pages(inode) && wbc->sync_mode == WB_SYNC_NONE)
1464 		return 0;
1465 
1466 	if (S_ISDIR(inode->i_mode) && wbc->sync_mode == WB_SYNC_NONE &&
1467 			get_dirty_pages(inode) < nr_pages_to_skip(sbi, DATA) &&
1468 			available_free_memory(sbi, DIRTY_DENTS))
1469 		goto skip_write;
1470 
1471 	/* skip writing during file defragment */
1472 	if (is_inode_flag_set(F2FS_I(inode), FI_DO_DEFRAG))
1473 		goto skip_write;
1474 
1475 	/* during POR, we don't need to trigger writepage at all. */
1476 	if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
1477 		goto skip_write;
1478 
1479 	trace_f2fs_writepages(mapping->host, wbc, DATA);
1480 
1481 	diff = nr_pages_to_write(sbi, DATA, wbc);
1482 
1483 	if (!S_ISDIR(inode->i_mode) && wbc->sync_mode == WB_SYNC_ALL) {
1484 		mutex_lock(&sbi->writepages);
1485 		locked = true;
1486 	}
1487 	ret = f2fs_write_cache_pages(mapping, wbc, __f2fs_writepage, mapping);
1488 	f2fs_submit_merged_bio_cond(sbi, inode, NULL, 0, DATA, WRITE);
1489 	if (locked)
1490 		mutex_unlock(&sbi->writepages);
1491 
1492 	remove_dirty_inode(inode);
1493 
1494 	wbc->nr_to_write = max((long)0, wbc->nr_to_write - diff);
1495 	return ret;
1496 
1497 skip_write:
1498 	wbc->pages_skipped += get_dirty_pages(inode);
1499 	trace_f2fs_writepages(mapping->host, wbc, DATA);
1500 	return 0;
1501 }
1502 
1503 static void f2fs_write_failed(struct address_space *mapping, loff_t to)
1504 {
1505 	struct inode *inode = mapping->host;
1506 	loff_t i_size = i_size_read(inode);
1507 
1508 	if (to > i_size) {
1509 		truncate_pagecache(inode, i_size);
1510 		truncate_blocks(inode, i_size, true);
1511 	}
1512 }
1513 
1514 static int prepare_write_begin(struct f2fs_sb_info *sbi,
1515 			struct page *page, loff_t pos, unsigned len,
1516 			block_t *blk_addr, bool *node_changed)
1517 {
1518 	struct inode *inode = page->mapping->host;
1519 	pgoff_t index = page->index;
1520 	struct dnode_of_data dn;
1521 	struct page *ipage;
1522 	bool locked = false;
1523 	struct extent_info ei;
1524 	int err = 0;
1525 
1526 	/*
1527 	 * we already allocated all the blocks, so we don't need to get
1528 	 * the block addresses when there is no need to fill the page.
1529 	 */
1530 	if (!f2fs_has_inline_data(inode) && !f2fs_encrypted_inode(inode) &&
1531 					len == PAGE_SIZE)
1532 		return 0;
1533 
1534 	if (f2fs_has_inline_data(inode) ||
1535 			(pos & PAGE_MASK) >= i_size_read(inode)) {
1536 		f2fs_lock_op(sbi);
1537 		locked = true;
1538 	}
1539 restart:
1540 	/* check inline_data */
1541 	ipage = get_node_page(sbi, inode->i_ino);
1542 	if (IS_ERR(ipage)) {
1543 		err = PTR_ERR(ipage);
1544 		goto unlock_out;
1545 	}
1546 
1547 	set_new_dnode(&dn, inode, ipage, ipage, 0);
1548 
1549 	if (f2fs_has_inline_data(inode)) {
1550 		if (pos + len <= MAX_INLINE_DATA) {
1551 			read_inline_data(page, ipage);
1552 			set_inode_flag(F2FS_I(inode), FI_DATA_EXIST);
1553 			if (inode->i_nlink)
1554 				set_inline_node(ipage);
1555 		} else {
1556 			err = f2fs_convert_inline_page(&dn, page);
1557 			if (err)
1558 				goto out;
1559 			if (dn.data_blkaddr == NULL_ADDR)
1560 				err = f2fs_get_block(&dn, index);
1561 		}
1562 	} else if (locked) {
1563 		err = f2fs_get_block(&dn, index);
1564 	} else {
1565 		if (f2fs_lookup_extent_cache(inode, index, &ei)) {
1566 			dn.data_blkaddr = ei.blk + index - ei.fofs;
1567 		} else {
1568 			/* hole case */
1569 			err = get_dnode_of_data(&dn, index, LOOKUP_NODE);
1570 			if (err || dn.data_blkaddr == NULL_ADDR) {
1571 				f2fs_put_dnode(&dn);
1572 				f2fs_lock_op(sbi);
1573 				locked = true;
1574 				goto restart;
1575 			}
1576 		}
1577 	}
1578 
1579 	/* convert_inline_page can make node_changed */
1580 	*blk_addr = dn.data_blkaddr;
1581 	*node_changed = dn.node_changed;
1582 out:
1583 	f2fs_put_dnode(&dn);
1584 unlock_out:
1585 	if (locked)
1586 		f2fs_unlock_op(sbi);
1587 	return err;
1588 }
1589 
1590 static int f2fs_write_begin(struct file *file, struct address_space *mapping,
1591 		loff_t pos, unsigned len, unsigned flags,
1592 		struct page **pagep, void **fsdata)
1593 {
1594 	struct inode *inode = mapping->host;
1595 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1596 	struct page *page = NULL;
1597 	pgoff_t index = ((unsigned long long) pos) >> PAGE_SHIFT;
1598 	bool need_balance = false;
1599 	block_t blkaddr = NULL_ADDR;
1600 	int err = 0;
1601 
1602 	trace_f2fs_write_begin(inode, pos, len, flags);
1603 
1604 	/*
1605 	 * We should check this at this moment to avoid deadlock on inode page
1606 	 * and #0 page. The locking rule for inline_data conversion should be:
1607 	 * lock_page(page #0) -> lock_page(inode_page)
1608 	 */
1609 	if (index != 0) {
1610 		err = f2fs_convert_inline_inode(inode);
1611 		if (err)
1612 			goto fail;
1613 	}
1614 repeat:
1615 	page = grab_cache_page_write_begin(mapping, index, flags);
1616 	if (!page) {
1617 		err = -ENOMEM;
1618 		goto fail;
1619 	}
1620 
1621 	*pagep = page;
1622 
1623 	err = prepare_write_begin(sbi, page, pos, len,
1624 					&blkaddr, &need_balance);
1625 	if (err)
1626 		goto fail;
1627 
1628 	if (need_balance && has_not_enough_free_secs(sbi, 0)) {
1629 		unlock_page(page);
1630 		f2fs_balance_fs(sbi, true);
1631 		lock_page(page);
1632 		if (page->mapping != mapping) {
1633 			/* The page got truncated from under us */
1634 			f2fs_put_page(page, 1);
1635 			goto repeat;
1636 		}
1637 	}
1638 
1639 	f2fs_wait_on_page_writeback(page, DATA, false);
1640 
1641 	/* wait for GCed encrypted page writeback */
1642 	if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode))
1643 		f2fs_wait_on_encrypted_page_writeback(sbi, blkaddr);
1644 
1645 	if (len == PAGE_SIZE)
1646 		goto out_update;
1647 	if (PageUptodate(page))
1648 		goto out_clear;
1649 
1650 	if ((pos & PAGE_MASK) >= i_size_read(inode)) {
1651 		unsigned start = pos & (PAGE_SIZE - 1);
1652 		unsigned end = start + len;
1653 
1654 		/* Reading beyond i_size is simple: memset to zero */
1655 		zero_user_segments(page, 0, start, end, PAGE_SIZE);
1656 		goto out_update;
1657 	}
1658 
1659 	if (blkaddr == NEW_ADDR) {
1660 		zero_user_segment(page, 0, PAGE_SIZE);
1661 	} else {
1662 		struct f2fs_io_info fio = {
1663 			.sbi = sbi,
1664 			.type = DATA,
1665 			.rw = READ_SYNC,
1666 			.old_blkaddr = blkaddr,
1667 			.new_blkaddr = blkaddr,
1668 			.page = page,
1669 			.encrypted_page = NULL,
1670 		};
1671 		err = f2fs_submit_page_bio(&fio);
1672 		if (err)
1673 			goto fail;
1674 
1675 		lock_page(page);
1676 		if (unlikely(!PageUptodate(page))) {
1677 			err = -EIO;
1678 			goto fail;
1679 		}
1680 		if (unlikely(page->mapping != mapping)) {
1681 			f2fs_put_page(page, 1);
1682 			goto repeat;
1683 		}
1684 
1685 		/* avoid symlink page */
1686 		if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode)) {
1687 			err = fscrypt_decrypt_page(page);
1688 			if (err)
1689 				goto fail;
1690 		}
1691 	}
1692 out_update:
1693 	SetPageUptodate(page);
1694 out_clear:
1695 	clear_cold_data(page);
1696 	return 0;
1697 
1698 fail:
1699 	f2fs_put_page(page, 1);
1700 	f2fs_write_failed(mapping, pos + len);
1701 	return err;
1702 }
1703 
1704 static int f2fs_write_end(struct file *file,
1705 			struct address_space *mapping,
1706 			loff_t pos, unsigned len, unsigned copied,
1707 			struct page *page, void *fsdata)
1708 {
1709 	struct inode *inode = page->mapping->host;
1710 
1711 	trace_f2fs_write_end(inode, pos, len, copied);
1712 
1713 	set_page_dirty(page);
1714 
1715 	if (pos + copied > i_size_read(inode)) {
1716 		i_size_write(inode, pos + copied);
1717 		mark_inode_dirty(inode);
1718 	}
1719 
1720 	f2fs_put_page(page, 1);
1721 	f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
1722 	return copied;
1723 }
1724 
1725 static int check_direct_IO(struct inode *inode, struct iov_iter *iter,
1726 			   loff_t offset)
1727 {
1728 	unsigned blocksize_mask = inode->i_sb->s_blocksize - 1;
1729 
1730 	if (offset & blocksize_mask)
1731 		return -EINVAL;
1732 
1733 	if (iov_iter_alignment(iter) & blocksize_mask)
1734 		return -EINVAL;
1735 
1736 	return 0;
1737 }
1738 
1739 static ssize_t f2fs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
1740 {
1741 	struct address_space *mapping = iocb->ki_filp->f_mapping;
1742 	struct inode *inode = mapping->host;
1743 	size_t count = iov_iter_count(iter);
1744 	loff_t offset = iocb->ki_pos;
1745 	int err;
1746 
1747 	err = check_direct_IO(inode, iter, offset);
1748 	if (err)
1749 		return err;
1750 
1751 	if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode))
1752 		return 0;
1753 
1754 	trace_f2fs_direct_IO_enter(inode, offset, count, iov_iter_rw(iter));
1755 
1756 	err = blockdev_direct_IO(iocb, inode, iter, get_data_block_dio);
1757 	if (iov_iter_rw(iter) == WRITE) {
1758 		if (err > 0)
1759 			set_inode_flag(F2FS_I(inode), FI_UPDATE_WRITE);
1760 		else if (err < 0)
1761 			f2fs_write_failed(mapping, offset + count);
1762 	}
1763 
1764 	trace_f2fs_direct_IO_exit(inode, offset, count, iov_iter_rw(iter), err);
1765 
1766 	return err;
1767 }
1768 
1769 void f2fs_invalidate_page(struct page *page, unsigned int offset,
1770 							unsigned int length)
1771 {
1772 	struct inode *inode = page->mapping->host;
1773 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1774 
1775 	if (inode->i_ino >= F2FS_ROOT_INO(sbi) &&
1776 		(offset % PAGE_SIZE || length != PAGE_SIZE))
1777 		return;
1778 
1779 	if (PageDirty(page)) {
1780 		if (inode->i_ino == F2FS_META_INO(sbi))
1781 			dec_page_count(sbi, F2FS_DIRTY_META);
1782 		else if (inode->i_ino == F2FS_NODE_INO(sbi))
1783 			dec_page_count(sbi, F2FS_DIRTY_NODES);
1784 		else
1785 			inode_dec_dirty_pages(inode);
1786 	}
1787 
1788 	/* This is atomic written page, keep Private */
1789 	if (IS_ATOMIC_WRITTEN_PAGE(page))
1790 		return;
1791 
1792 	set_page_private(page, 0);
1793 	ClearPagePrivate(page);
1794 }
1795 
1796 int f2fs_release_page(struct page *page, gfp_t wait)
1797 {
1798 	/* If this is dirty page, keep PagePrivate */
1799 	if (PageDirty(page))
1800 		return 0;
1801 
1802 	/* This is atomic written page, keep Private */
1803 	if (IS_ATOMIC_WRITTEN_PAGE(page))
1804 		return 0;
1805 
1806 	set_page_private(page, 0);
1807 	ClearPagePrivate(page);
1808 	return 1;
1809 }
1810 
1811 static int f2fs_set_data_page_dirty(struct page *page)
1812 {
1813 	struct address_space *mapping = page->mapping;
1814 	struct inode *inode = mapping->host;
1815 
1816 	trace_f2fs_set_page_dirty(page, DATA);
1817 
1818 	SetPageUptodate(page);
1819 
1820 	if (f2fs_is_atomic_file(inode)) {
1821 		if (!IS_ATOMIC_WRITTEN_PAGE(page)) {
1822 			register_inmem_page(inode, page);
1823 			return 1;
1824 		}
1825 		/*
1826 		 * Previously, this page has been registered, we just
1827 		 * return here.
1828 		 */
1829 		return 0;
1830 	}
1831 
1832 	if (!PageDirty(page)) {
1833 		__set_page_dirty_nobuffers(page);
1834 		update_dirty_page(inode, page);
1835 		return 1;
1836 	}
1837 	return 0;
1838 }
1839 
1840 static sector_t f2fs_bmap(struct address_space *mapping, sector_t block)
1841 {
1842 	struct inode *inode = mapping->host;
1843 
1844 	if (f2fs_has_inline_data(inode))
1845 		return 0;
1846 
1847 	/* make sure allocating whole blocks */
1848 	if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
1849 		filemap_write_and_wait(mapping);
1850 
1851 	return generic_block_bmap(mapping, block, get_data_block_bmap);
1852 }
1853 
1854 const struct address_space_operations f2fs_dblock_aops = {
1855 	.readpage	= f2fs_read_data_page,
1856 	.readpages	= f2fs_read_data_pages,
1857 	.writepage	= f2fs_write_data_page,
1858 	.writepages	= f2fs_write_data_pages,
1859 	.write_begin	= f2fs_write_begin,
1860 	.write_end	= f2fs_write_end,
1861 	.set_page_dirty	= f2fs_set_data_page_dirty,
1862 	.invalidatepage	= f2fs_invalidate_page,
1863 	.releasepage	= f2fs_release_page,
1864 	.direct_IO	= f2fs_direct_IO,
1865 	.bmap		= f2fs_bmap,
1866 };
1867