xref: /openbmc/linux/fs/f2fs/data.c (revision e57e9ae5b179a6b243c42bf6d9549d1595c27089)
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 void f2fs_read_end_io(struct bio *bio)
33 {
34 	struct bio_vec *bvec;
35 	int i;
36 
37 #ifdef CONFIG_F2FS_FAULT_INJECTION
38 	if (time_to_inject(F2FS_P_SB(bio->bi_io_vec->bv_page), FAULT_IO))
39 		bio->bi_error = -EIO;
40 #endif
41 
42 	if (f2fs_bio_encrypted(bio)) {
43 		if (bio->bi_error) {
44 			fscrypt_release_ctx(bio->bi_private);
45 		} else {
46 			fscrypt_decrypt_bio_pages(bio->bi_private, bio);
47 			return;
48 		}
49 	}
50 
51 	bio_for_each_segment_all(bvec, bio, i) {
52 		struct page *page = bvec->bv_page;
53 
54 		if (!bio->bi_error) {
55 			if (!PageUptodate(page))
56 				SetPageUptodate(page);
57 		} else {
58 			ClearPageUptodate(page);
59 			SetPageError(page);
60 		}
61 		unlock_page(page);
62 	}
63 	bio_put(bio);
64 }
65 
66 static void f2fs_write_end_io(struct bio *bio)
67 {
68 	struct f2fs_sb_info *sbi = bio->bi_private;
69 	struct bio_vec *bvec;
70 	int i;
71 
72 	bio_for_each_segment_all(bvec, bio, i) {
73 		struct page *page = bvec->bv_page;
74 
75 		fscrypt_pullback_bio_page(&page, true);
76 
77 		if (unlikely(bio->bi_error)) {
78 			mapping_set_error(page->mapping, -EIO);
79 			f2fs_stop_checkpoint(sbi, true);
80 		}
81 		end_page_writeback(page);
82 	}
83 	if (atomic_dec_and_test(&sbi->nr_wb_bios) &&
84 				wq_has_sleeper(&sbi->cp_wait))
85 		wake_up(&sbi->cp_wait);
86 
87 	bio_put(bio);
88 }
89 
90 /*
91  * Low-level block read/write IO operations.
92  */
93 static struct bio *__bio_alloc(struct f2fs_sb_info *sbi, block_t blk_addr,
94 				int npages, bool is_read)
95 {
96 	struct bio *bio;
97 
98 	bio = f2fs_bio_alloc(npages);
99 
100 	bio->bi_bdev = sbi->sb->s_bdev;
101 	bio->bi_iter.bi_sector = SECTOR_FROM_BLOCK(blk_addr);
102 	bio->bi_end_io = is_read ? f2fs_read_end_io : f2fs_write_end_io;
103 	bio->bi_private = is_read ? NULL : sbi;
104 
105 	return bio;
106 }
107 
108 static inline void __submit_bio(struct f2fs_sb_info *sbi,
109 				struct bio *bio, enum page_type type)
110 {
111 	if (!is_read_io(bio_op(bio))) {
112 		atomic_inc(&sbi->nr_wb_bios);
113 		if (f2fs_sb_mounted_blkzoned(sbi->sb) &&
114 			current->plug && (type == DATA || type == NODE))
115 			blk_finish_plug(current->plug);
116 	}
117 	submit_bio(bio);
118 }
119 
120 static void __submit_merged_bio(struct f2fs_bio_info *io)
121 {
122 	struct f2fs_io_info *fio = &io->fio;
123 
124 	if (!io->bio)
125 		return;
126 
127 	if (is_read_io(fio->op))
128 		trace_f2fs_submit_read_bio(io->sbi->sb, fio, io->bio);
129 	else
130 		trace_f2fs_submit_write_bio(io->sbi->sb, fio, io->bio);
131 
132 	bio_set_op_attrs(io->bio, fio->op, fio->op_flags);
133 
134 	__submit_bio(io->sbi, io->bio, fio->type);
135 	io->bio = NULL;
136 }
137 
138 static bool __has_merged_page(struct f2fs_bio_info *io, struct inode *inode,
139 						struct page *page, nid_t ino)
140 {
141 	struct bio_vec *bvec;
142 	struct page *target;
143 	int i;
144 
145 	if (!io->bio)
146 		return false;
147 
148 	if (!inode && !page && !ino)
149 		return true;
150 
151 	bio_for_each_segment_all(bvec, io->bio, i) {
152 
153 		if (bvec->bv_page->mapping)
154 			target = bvec->bv_page;
155 		else
156 			target = fscrypt_control_page(bvec->bv_page);
157 
158 		if (inode && inode == target->mapping->host)
159 			return true;
160 		if (page && page == target)
161 			return true;
162 		if (ino && ino == ino_of_node(target))
163 			return true;
164 	}
165 
166 	return false;
167 }
168 
169 static bool has_merged_page(struct f2fs_sb_info *sbi, struct inode *inode,
170 						struct page *page, nid_t ino,
171 						enum page_type type)
172 {
173 	enum page_type btype = PAGE_TYPE_OF_BIO(type);
174 	struct f2fs_bio_info *io = &sbi->write_io[btype];
175 	bool ret;
176 
177 	down_read(&io->io_rwsem);
178 	ret = __has_merged_page(io, inode, page, ino);
179 	up_read(&io->io_rwsem);
180 	return ret;
181 }
182 
183 static void __f2fs_submit_merged_bio(struct f2fs_sb_info *sbi,
184 				struct inode *inode, struct page *page,
185 				nid_t ino, enum page_type type, int rw)
186 {
187 	enum page_type btype = PAGE_TYPE_OF_BIO(type);
188 	struct f2fs_bio_info *io;
189 
190 	io = is_read_io(rw) ? &sbi->read_io : &sbi->write_io[btype];
191 
192 	down_write(&io->io_rwsem);
193 
194 	if (!__has_merged_page(io, inode, page, ino))
195 		goto out;
196 
197 	/* change META to META_FLUSH in the checkpoint procedure */
198 	if (type >= META_FLUSH) {
199 		io->fio.type = META_FLUSH;
200 		io->fio.op = REQ_OP_WRITE;
201 		if (test_opt(sbi, NOBARRIER))
202 			io->fio.op_flags = WRITE_FLUSH | REQ_META | REQ_PRIO;
203 		else
204 			io->fio.op_flags = WRITE_FLUSH_FUA | REQ_META |
205 								REQ_PRIO;
206 	}
207 	__submit_merged_bio(io);
208 out:
209 	up_write(&io->io_rwsem);
210 }
211 
212 void f2fs_submit_merged_bio(struct f2fs_sb_info *sbi, enum page_type type,
213 									int rw)
214 {
215 	__f2fs_submit_merged_bio(sbi, NULL, NULL, 0, type, rw);
216 }
217 
218 void f2fs_submit_merged_bio_cond(struct f2fs_sb_info *sbi,
219 				struct inode *inode, struct page *page,
220 				nid_t ino, enum page_type type, int rw)
221 {
222 	if (has_merged_page(sbi, inode, page, ino, type))
223 		__f2fs_submit_merged_bio(sbi, inode, page, ino, type, rw);
224 }
225 
226 void f2fs_flush_merged_bios(struct f2fs_sb_info *sbi)
227 {
228 	f2fs_submit_merged_bio(sbi, DATA, WRITE);
229 	f2fs_submit_merged_bio(sbi, NODE, WRITE);
230 	f2fs_submit_merged_bio(sbi, META, WRITE);
231 }
232 
233 /*
234  * Fill the locked page with data located in the block address.
235  * Return unlocked page.
236  */
237 int f2fs_submit_page_bio(struct f2fs_io_info *fio)
238 {
239 	struct bio *bio;
240 	struct page *page = fio->encrypted_page ?
241 			fio->encrypted_page : fio->page;
242 
243 	trace_f2fs_submit_page_bio(page, fio);
244 	f2fs_trace_ios(fio, 0);
245 
246 	/* Allocate a new bio */
247 	bio = __bio_alloc(fio->sbi, fio->new_blkaddr, 1, is_read_io(fio->op));
248 
249 	if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
250 		bio_put(bio);
251 		return -EFAULT;
252 	}
253 	bio_set_op_attrs(bio, fio->op, fio->op_flags);
254 
255 	__submit_bio(fio->sbi, bio, fio->type);
256 	return 0;
257 }
258 
259 void f2fs_submit_page_mbio(struct f2fs_io_info *fio)
260 {
261 	struct f2fs_sb_info *sbi = fio->sbi;
262 	enum page_type btype = PAGE_TYPE_OF_BIO(fio->type);
263 	struct f2fs_bio_info *io;
264 	bool is_read = is_read_io(fio->op);
265 	struct page *bio_page;
266 
267 	io = is_read ? &sbi->read_io : &sbi->write_io[btype];
268 
269 	if (fio->old_blkaddr != NEW_ADDR)
270 		verify_block_addr(sbi, fio->old_blkaddr);
271 	verify_block_addr(sbi, fio->new_blkaddr);
272 
273 	down_write(&io->io_rwsem);
274 
275 	if (io->bio && (io->last_block_in_bio != fio->new_blkaddr - 1 ||
276 	    (io->fio.op != fio->op || io->fio.op_flags != fio->op_flags)))
277 		__submit_merged_bio(io);
278 alloc_new:
279 	if (io->bio == NULL) {
280 		io->bio = __bio_alloc(sbi, fio->new_blkaddr,
281 						BIO_MAX_PAGES, is_read);
282 		io->fio = *fio;
283 	}
284 
285 	bio_page = fio->encrypted_page ? fio->encrypted_page : fio->page;
286 
287 	if (bio_add_page(io->bio, bio_page, PAGE_SIZE, 0) <
288 							PAGE_SIZE) {
289 		__submit_merged_bio(io);
290 		goto alloc_new;
291 	}
292 
293 	io->last_block_in_bio = fio->new_blkaddr;
294 	f2fs_trace_ios(fio, 0);
295 
296 	up_write(&io->io_rwsem);
297 	trace_f2fs_submit_page_mbio(fio->page, fio);
298 }
299 
300 static void __set_data_blkaddr(struct dnode_of_data *dn)
301 {
302 	struct f2fs_node *rn = F2FS_NODE(dn->node_page);
303 	__le32 *addr_array;
304 
305 	/* Get physical address of data block */
306 	addr_array = blkaddr_in_node(rn);
307 	addr_array[dn->ofs_in_node] = cpu_to_le32(dn->data_blkaddr);
308 }
309 
310 /*
311  * Lock ordering for the change of data block address:
312  * ->data_page
313  *  ->node_page
314  *    update block addresses in the node page
315  */
316 void set_data_blkaddr(struct dnode_of_data *dn)
317 {
318 	f2fs_wait_on_page_writeback(dn->node_page, NODE, true);
319 	__set_data_blkaddr(dn);
320 	if (set_page_dirty(dn->node_page))
321 		dn->node_changed = true;
322 }
323 
324 void f2fs_update_data_blkaddr(struct dnode_of_data *dn, block_t blkaddr)
325 {
326 	dn->data_blkaddr = blkaddr;
327 	set_data_blkaddr(dn);
328 	f2fs_update_extent_cache(dn);
329 }
330 
331 /* dn->ofs_in_node will be returned with up-to-date last block pointer */
332 int reserve_new_blocks(struct dnode_of_data *dn, blkcnt_t count)
333 {
334 	struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
335 
336 	if (!count)
337 		return 0;
338 
339 	if (unlikely(is_inode_flag_set(dn->inode, FI_NO_ALLOC)))
340 		return -EPERM;
341 	if (unlikely(!inc_valid_block_count(sbi, dn->inode, &count)))
342 		return -ENOSPC;
343 
344 	trace_f2fs_reserve_new_blocks(dn->inode, dn->nid,
345 						dn->ofs_in_node, count);
346 
347 	f2fs_wait_on_page_writeback(dn->node_page, NODE, true);
348 
349 	for (; count > 0; dn->ofs_in_node++) {
350 		block_t blkaddr =
351 			datablock_addr(dn->node_page, dn->ofs_in_node);
352 		if (blkaddr == NULL_ADDR) {
353 			dn->data_blkaddr = NEW_ADDR;
354 			__set_data_blkaddr(dn);
355 			count--;
356 		}
357 	}
358 
359 	if (set_page_dirty(dn->node_page))
360 		dn->node_changed = true;
361 	return 0;
362 }
363 
364 /* Should keep dn->ofs_in_node unchanged */
365 int reserve_new_block(struct dnode_of_data *dn)
366 {
367 	unsigned int ofs_in_node = dn->ofs_in_node;
368 	int ret;
369 
370 	ret = reserve_new_blocks(dn, 1);
371 	dn->ofs_in_node = ofs_in_node;
372 	return ret;
373 }
374 
375 int f2fs_reserve_block(struct dnode_of_data *dn, pgoff_t index)
376 {
377 	bool need_put = dn->inode_page ? false : true;
378 	int err;
379 
380 	err = get_dnode_of_data(dn, index, ALLOC_NODE);
381 	if (err)
382 		return err;
383 
384 	if (dn->data_blkaddr == NULL_ADDR)
385 		err = reserve_new_block(dn);
386 	if (err || need_put)
387 		f2fs_put_dnode(dn);
388 	return err;
389 }
390 
391 int f2fs_get_block(struct dnode_of_data *dn, pgoff_t index)
392 {
393 	struct extent_info ei;
394 	struct inode *inode = dn->inode;
395 
396 	if (f2fs_lookup_extent_cache(inode, index, &ei)) {
397 		dn->data_blkaddr = ei.blk + index - ei.fofs;
398 		return 0;
399 	}
400 
401 	return f2fs_reserve_block(dn, index);
402 }
403 
404 struct page *get_read_data_page(struct inode *inode, pgoff_t index,
405 						int op_flags, bool for_write)
406 {
407 	struct address_space *mapping = inode->i_mapping;
408 	struct dnode_of_data dn;
409 	struct page *page;
410 	struct extent_info ei;
411 	int err;
412 	struct f2fs_io_info fio = {
413 		.sbi = F2FS_I_SB(inode),
414 		.type = DATA,
415 		.op = REQ_OP_READ,
416 		.op_flags = op_flags,
417 		.encrypted_page = NULL,
418 	};
419 
420 	if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode))
421 		return read_mapping_page(mapping, index, NULL);
422 
423 	page = f2fs_grab_cache_page(mapping, index, for_write);
424 	if (!page)
425 		return ERR_PTR(-ENOMEM);
426 
427 	if (f2fs_lookup_extent_cache(inode, index, &ei)) {
428 		dn.data_blkaddr = ei.blk + index - ei.fofs;
429 		goto got_it;
430 	}
431 
432 	set_new_dnode(&dn, inode, NULL, NULL, 0);
433 	err = get_dnode_of_data(&dn, index, LOOKUP_NODE);
434 	if (err)
435 		goto put_err;
436 	f2fs_put_dnode(&dn);
437 
438 	if (unlikely(dn.data_blkaddr == NULL_ADDR)) {
439 		err = -ENOENT;
440 		goto put_err;
441 	}
442 got_it:
443 	if (PageUptodate(page)) {
444 		unlock_page(page);
445 		return page;
446 	}
447 
448 	/*
449 	 * A new dentry page is allocated but not able to be written, since its
450 	 * new inode page couldn't be allocated due to -ENOSPC.
451 	 * In such the case, its blkaddr can be remained as NEW_ADDR.
452 	 * see, f2fs_add_link -> get_new_data_page -> init_inode_metadata.
453 	 */
454 	if (dn.data_blkaddr == NEW_ADDR) {
455 		zero_user_segment(page, 0, PAGE_SIZE);
456 		if (!PageUptodate(page))
457 			SetPageUptodate(page);
458 		unlock_page(page);
459 		return page;
460 	}
461 
462 	fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
463 	fio.page = page;
464 	err = f2fs_submit_page_bio(&fio);
465 	if (err)
466 		goto put_err;
467 	return page;
468 
469 put_err:
470 	f2fs_put_page(page, 1);
471 	return ERR_PTR(err);
472 }
473 
474 struct page *find_data_page(struct inode *inode, pgoff_t index)
475 {
476 	struct address_space *mapping = inode->i_mapping;
477 	struct page *page;
478 
479 	page = find_get_page(mapping, index);
480 	if (page && PageUptodate(page))
481 		return page;
482 	f2fs_put_page(page, 0);
483 
484 	page = get_read_data_page(inode, index, READ_SYNC, false);
485 	if (IS_ERR(page))
486 		return page;
487 
488 	if (PageUptodate(page))
489 		return page;
490 
491 	wait_on_page_locked(page);
492 	if (unlikely(!PageUptodate(page))) {
493 		f2fs_put_page(page, 0);
494 		return ERR_PTR(-EIO);
495 	}
496 	return page;
497 }
498 
499 /*
500  * If it tries to access a hole, return an error.
501  * Because, the callers, functions in dir.c and GC, should be able to know
502  * whether this page exists or not.
503  */
504 struct page *get_lock_data_page(struct inode *inode, pgoff_t index,
505 							bool for_write)
506 {
507 	struct address_space *mapping = inode->i_mapping;
508 	struct page *page;
509 repeat:
510 	page = get_read_data_page(inode, index, READ_SYNC, for_write);
511 	if (IS_ERR(page))
512 		return page;
513 
514 	/* wait for read completion */
515 	lock_page(page);
516 	if (unlikely(page->mapping != mapping)) {
517 		f2fs_put_page(page, 1);
518 		goto repeat;
519 	}
520 	if (unlikely(!PageUptodate(page))) {
521 		f2fs_put_page(page, 1);
522 		return ERR_PTR(-EIO);
523 	}
524 	return page;
525 }
526 
527 /*
528  * Caller ensures that this data page is never allocated.
529  * A new zero-filled data page is allocated in the page cache.
530  *
531  * Also, caller should grab and release a rwsem by calling f2fs_lock_op() and
532  * f2fs_unlock_op().
533  * Note that, ipage is set only by make_empty_dir, and if any error occur,
534  * ipage should be released by this function.
535  */
536 struct page *get_new_data_page(struct inode *inode,
537 		struct page *ipage, pgoff_t index, bool new_i_size)
538 {
539 	struct address_space *mapping = inode->i_mapping;
540 	struct page *page;
541 	struct dnode_of_data dn;
542 	int err;
543 
544 	page = f2fs_grab_cache_page(mapping, index, true);
545 	if (!page) {
546 		/*
547 		 * before exiting, we should make sure ipage will be released
548 		 * if any error occur.
549 		 */
550 		f2fs_put_page(ipage, 1);
551 		return ERR_PTR(-ENOMEM);
552 	}
553 
554 	set_new_dnode(&dn, inode, ipage, NULL, 0);
555 	err = f2fs_reserve_block(&dn, index);
556 	if (err) {
557 		f2fs_put_page(page, 1);
558 		return ERR_PTR(err);
559 	}
560 	if (!ipage)
561 		f2fs_put_dnode(&dn);
562 
563 	if (PageUptodate(page))
564 		goto got_it;
565 
566 	if (dn.data_blkaddr == NEW_ADDR) {
567 		zero_user_segment(page, 0, PAGE_SIZE);
568 		if (!PageUptodate(page))
569 			SetPageUptodate(page);
570 	} else {
571 		f2fs_put_page(page, 1);
572 
573 		/* if ipage exists, blkaddr should be NEW_ADDR */
574 		f2fs_bug_on(F2FS_I_SB(inode), ipage);
575 		page = get_lock_data_page(inode, index, true);
576 		if (IS_ERR(page))
577 			return page;
578 	}
579 got_it:
580 	if (new_i_size && i_size_read(inode) <
581 				((loff_t)(index + 1) << PAGE_SHIFT))
582 		f2fs_i_size_write(inode, ((loff_t)(index + 1) << PAGE_SHIFT));
583 	return page;
584 }
585 
586 static int __allocate_data_block(struct dnode_of_data *dn)
587 {
588 	struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
589 	struct f2fs_summary sum;
590 	struct node_info ni;
591 	pgoff_t fofs;
592 	blkcnt_t count = 1;
593 
594 	if (unlikely(is_inode_flag_set(dn->inode, FI_NO_ALLOC)))
595 		return -EPERM;
596 
597 	dn->data_blkaddr = datablock_addr(dn->node_page, dn->ofs_in_node);
598 	if (dn->data_blkaddr == NEW_ADDR)
599 		goto alloc;
600 
601 	if (unlikely(!inc_valid_block_count(sbi, dn->inode, &count)))
602 		return -ENOSPC;
603 
604 alloc:
605 	get_node_info(sbi, dn->nid, &ni);
606 	set_summary(&sum, dn->nid, dn->ofs_in_node, ni.version);
607 
608 	allocate_data_block(sbi, NULL, dn->data_blkaddr, &dn->data_blkaddr,
609 						&sum, CURSEG_WARM_DATA);
610 	set_data_blkaddr(dn);
611 
612 	/* update i_size */
613 	fofs = start_bidx_of_node(ofs_of_node(dn->node_page), dn->inode) +
614 							dn->ofs_in_node;
615 	if (i_size_read(dn->inode) < ((loff_t)(fofs + 1) << PAGE_SHIFT))
616 		f2fs_i_size_write(dn->inode,
617 				((loff_t)(fofs + 1) << PAGE_SHIFT));
618 	return 0;
619 }
620 
621 ssize_t f2fs_preallocate_blocks(struct kiocb *iocb, struct iov_iter *from)
622 {
623 	struct inode *inode = file_inode(iocb->ki_filp);
624 	struct f2fs_map_blocks map;
625 	ssize_t ret = 0;
626 
627 	map.m_lblk = F2FS_BLK_ALIGN(iocb->ki_pos);
628 	map.m_len = F2FS_BYTES_TO_BLK(iocb->ki_pos + iov_iter_count(from));
629 	if (map.m_len > map.m_lblk)
630 		map.m_len -= map.m_lblk;
631 	else
632 		map.m_len = 0;
633 
634 	map.m_next_pgofs = NULL;
635 
636 	if (iocb->ki_flags & IOCB_DIRECT) {
637 		ret = f2fs_convert_inline_inode(inode);
638 		if (ret)
639 			return ret;
640 		return f2fs_map_blocks(inode, &map, 1, F2FS_GET_BLOCK_PRE_DIO);
641 	}
642 	if (iocb->ki_pos + iov_iter_count(from) > MAX_INLINE_DATA) {
643 		ret = f2fs_convert_inline_inode(inode);
644 		if (ret)
645 			return ret;
646 	}
647 	if (!f2fs_has_inline_data(inode))
648 		return f2fs_map_blocks(inode, &map, 1, F2FS_GET_BLOCK_PRE_AIO);
649 	return ret;
650 }
651 
652 /*
653  * f2fs_map_blocks() now supported readahead/bmap/rw direct_IO with
654  * f2fs_map_blocks structure.
655  * If original data blocks are allocated, then give them to blockdev.
656  * Otherwise,
657  *     a. preallocate requested block addresses
658  *     b. do not use extent cache for better performance
659  *     c. give the block addresses to blockdev
660  */
661 int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map,
662 						int create, int flag)
663 {
664 	unsigned int maxblocks = map->m_len;
665 	struct dnode_of_data dn;
666 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
667 	int mode = create ? ALLOC_NODE : LOOKUP_NODE;
668 	pgoff_t pgofs, end_offset, end;
669 	int err = 0, ofs = 1;
670 	unsigned int ofs_in_node, last_ofs_in_node;
671 	blkcnt_t prealloc;
672 	struct extent_info ei;
673 	block_t blkaddr;
674 
675 	if (!maxblocks)
676 		return 0;
677 
678 	map->m_len = 0;
679 	map->m_flags = 0;
680 
681 	/* it only supports block size == page size */
682 	pgofs =	(pgoff_t)map->m_lblk;
683 	end = pgofs + maxblocks;
684 
685 	if (!create && f2fs_lookup_extent_cache(inode, pgofs, &ei)) {
686 		map->m_pblk = ei.blk + pgofs - ei.fofs;
687 		map->m_len = min((pgoff_t)maxblocks, ei.fofs + ei.len - pgofs);
688 		map->m_flags = F2FS_MAP_MAPPED;
689 		goto out;
690 	}
691 
692 next_dnode:
693 	if (create)
694 		f2fs_lock_op(sbi);
695 
696 	/* When reading holes, we need its node page */
697 	set_new_dnode(&dn, inode, NULL, NULL, 0);
698 	err = get_dnode_of_data(&dn, pgofs, mode);
699 	if (err) {
700 		if (flag == F2FS_GET_BLOCK_BMAP)
701 			map->m_pblk = 0;
702 		if (err == -ENOENT) {
703 			err = 0;
704 			if (map->m_next_pgofs)
705 				*map->m_next_pgofs =
706 					get_next_page_offset(&dn, pgofs);
707 		}
708 		goto unlock_out;
709 	}
710 
711 	prealloc = 0;
712 	last_ofs_in_node = ofs_in_node = dn.ofs_in_node;
713 	end_offset = ADDRS_PER_PAGE(dn.node_page, inode);
714 
715 next_block:
716 	blkaddr = datablock_addr(dn.node_page, dn.ofs_in_node);
717 
718 	if (blkaddr == NEW_ADDR || blkaddr == NULL_ADDR) {
719 		if (create) {
720 			if (unlikely(f2fs_cp_error(sbi))) {
721 				err = -EIO;
722 				goto sync_out;
723 			}
724 			if (flag == F2FS_GET_BLOCK_PRE_AIO) {
725 				if (blkaddr == NULL_ADDR) {
726 					prealloc++;
727 					last_ofs_in_node = dn.ofs_in_node;
728 				}
729 			} else {
730 				err = __allocate_data_block(&dn);
731 				if (!err)
732 					set_inode_flag(inode, FI_APPEND_WRITE);
733 			}
734 			if (err)
735 				goto sync_out;
736 			map->m_flags = F2FS_MAP_NEW;
737 			blkaddr = dn.data_blkaddr;
738 		} else {
739 			if (flag == F2FS_GET_BLOCK_BMAP) {
740 				map->m_pblk = 0;
741 				goto sync_out;
742 			}
743 			if (flag == F2FS_GET_BLOCK_FIEMAP &&
744 						blkaddr == NULL_ADDR) {
745 				if (map->m_next_pgofs)
746 					*map->m_next_pgofs = pgofs + 1;
747 			}
748 			if (flag != F2FS_GET_BLOCK_FIEMAP ||
749 						blkaddr != NEW_ADDR)
750 				goto sync_out;
751 		}
752 	}
753 
754 	if (flag == F2FS_GET_BLOCK_PRE_AIO)
755 		goto skip;
756 
757 	if (map->m_len == 0) {
758 		/* preallocated unwritten block should be mapped for fiemap. */
759 		if (blkaddr == NEW_ADDR)
760 			map->m_flags |= F2FS_MAP_UNWRITTEN;
761 		map->m_flags |= F2FS_MAP_MAPPED;
762 
763 		map->m_pblk = blkaddr;
764 		map->m_len = 1;
765 	} else if ((map->m_pblk != NEW_ADDR &&
766 			blkaddr == (map->m_pblk + ofs)) ||
767 			(map->m_pblk == NEW_ADDR && blkaddr == NEW_ADDR) ||
768 			flag == F2FS_GET_BLOCK_PRE_DIO) {
769 		ofs++;
770 		map->m_len++;
771 	} else {
772 		goto sync_out;
773 	}
774 
775 skip:
776 	dn.ofs_in_node++;
777 	pgofs++;
778 
779 	/* preallocate blocks in batch for one dnode page */
780 	if (flag == F2FS_GET_BLOCK_PRE_AIO &&
781 			(pgofs == end || dn.ofs_in_node == end_offset)) {
782 
783 		dn.ofs_in_node = ofs_in_node;
784 		err = reserve_new_blocks(&dn, prealloc);
785 		if (err)
786 			goto sync_out;
787 
788 		map->m_len += dn.ofs_in_node - ofs_in_node;
789 		if (prealloc && dn.ofs_in_node != last_ofs_in_node + 1) {
790 			err = -ENOSPC;
791 			goto sync_out;
792 		}
793 		dn.ofs_in_node = end_offset;
794 	}
795 
796 	if (pgofs >= end)
797 		goto sync_out;
798 	else if (dn.ofs_in_node < end_offset)
799 		goto next_block;
800 
801 	f2fs_put_dnode(&dn);
802 
803 	if (create) {
804 		f2fs_unlock_op(sbi);
805 		f2fs_balance_fs(sbi, dn.node_changed);
806 	}
807 	goto next_dnode;
808 
809 sync_out:
810 	f2fs_put_dnode(&dn);
811 unlock_out:
812 	if (create) {
813 		f2fs_unlock_op(sbi);
814 		f2fs_balance_fs(sbi, dn.node_changed);
815 	}
816 out:
817 	trace_f2fs_map_blocks(inode, map, err);
818 	return err;
819 }
820 
821 static int __get_data_block(struct inode *inode, sector_t iblock,
822 			struct buffer_head *bh, int create, int flag,
823 			pgoff_t *next_pgofs)
824 {
825 	struct f2fs_map_blocks map;
826 	int ret;
827 
828 	map.m_lblk = iblock;
829 	map.m_len = bh->b_size >> inode->i_blkbits;
830 	map.m_next_pgofs = next_pgofs;
831 
832 	ret = f2fs_map_blocks(inode, &map, create, flag);
833 	if (!ret) {
834 		map_bh(bh, inode->i_sb, map.m_pblk);
835 		bh->b_state = (bh->b_state & ~F2FS_MAP_FLAGS) | map.m_flags;
836 		bh->b_size = map.m_len << inode->i_blkbits;
837 	}
838 	return ret;
839 }
840 
841 static int get_data_block(struct inode *inode, sector_t iblock,
842 			struct buffer_head *bh_result, int create, int flag,
843 			pgoff_t *next_pgofs)
844 {
845 	return __get_data_block(inode, iblock, bh_result, create,
846 							flag, next_pgofs);
847 }
848 
849 static int get_data_block_dio(struct inode *inode, sector_t iblock,
850 			struct buffer_head *bh_result, int create)
851 {
852 	return __get_data_block(inode, iblock, bh_result, create,
853 						F2FS_GET_BLOCK_DIO, NULL);
854 }
855 
856 static int get_data_block_bmap(struct inode *inode, sector_t iblock,
857 			struct buffer_head *bh_result, int create)
858 {
859 	/* Block number less than F2FS MAX BLOCKS */
860 	if (unlikely(iblock >= F2FS_I_SB(inode)->max_file_blocks))
861 		return -EFBIG;
862 
863 	return __get_data_block(inode, iblock, bh_result, create,
864 						F2FS_GET_BLOCK_BMAP, NULL);
865 }
866 
867 static inline sector_t logical_to_blk(struct inode *inode, loff_t offset)
868 {
869 	return (offset >> inode->i_blkbits);
870 }
871 
872 static inline loff_t blk_to_logical(struct inode *inode, sector_t blk)
873 {
874 	return (blk << inode->i_blkbits);
875 }
876 
877 int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
878 		u64 start, u64 len)
879 {
880 	struct buffer_head map_bh;
881 	sector_t start_blk, last_blk;
882 	pgoff_t next_pgofs;
883 	u64 logical = 0, phys = 0, size = 0;
884 	u32 flags = 0;
885 	int ret = 0;
886 
887 	ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC);
888 	if (ret)
889 		return ret;
890 
891 	if (f2fs_has_inline_data(inode)) {
892 		ret = f2fs_inline_data_fiemap(inode, fieinfo, start, len);
893 		if (ret != -EAGAIN)
894 			return ret;
895 	}
896 
897 	inode_lock(inode);
898 
899 	if (logical_to_blk(inode, len) == 0)
900 		len = blk_to_logical(inode, 1);
901 
902 	start_blk = logical_to_blk(inode, start);
903 	last_blk = logical_to_blk(inode, start + len - 1);
904 
905 next:
906 	memset(&map_bh, 0, sizeof(struct buffer_head));
907 	map_bh.b_size = len;
908 
909 	ret = get_data_block(inode, start_blk, &map_bh, 0,
910 					F2FS_GET_BLOCK_FIEMAP, &next_pgofs);
911 	if (ret)
912 		goto out;
913 
914 	/* HOLE */
915 	if (!buffer_mapped(&map_bh)) {
916 		start_blk = next_pgofs;
917 
918 		if (blk_to_logical(inode, start_blk) < blk_to_logical(inode,
919 					F2FS_I_SB(inode)->max_file_blocks))
920 			goto prep_next;
921 
922 		flags |= FIEMAP_EXTENT_LAST;
923 	}
924 
925 	if (size) {
926 		if (f2fs_encrypted_inode(inode))
927 			flags |= FIEMAP_EXTENT_DATA_ENCRYPTED;
928 
929 		ret = fiemap_fill_next_extent(fieinfo, logical,
930 				phys, size, flags);
931 	}
932 
933 	if (start_blk > last_blk || ret)
934 		goto out;
935 
936 	logical = blk_to_logical(inode, start_blk);
937 	phys = blk_to_logical(inode, map_bh.b_blocknr);
938 	size = map_bh.b_size;
939 	flags = 0;
940 	if (buffer_unwritten(&map_bh))
941 		flags = FIEMAP_EXTENT_UNWRITTEN;
942 
943 	start_blk += logical_to_blk(inode, size);
944 
945 prep_next:
946 	cond_resched();
947 	if (fatal_signal_pending(current))
948 		ret = -EINTR;
949 	else
950 		goto next;
951 out:
952 	if (ret == 1)
953 		ret = 0;
954 
955 	inode_unlock(inode);
956 	return ret;
957 }
958 
959 static struct bio *f2fs_grab_bio(struct inode *inode, block_t blkaddr,
960 				 unsigned nr_pages)
961 {
962 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
963 	struct fscrypt_ctx *ctx = NULL;
964 	struct block_device *bdev = sbi->sb->s_bdev;
965 	struct bio *bio;
966 
967 	if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode)) {
968 		ctx = fscrypt_get_ctx(inode, GFP_NOFS);
969 		if (IS_ERR(ctx))
970 			return ERR_CAST(ctx);
971 
972 		/* wait the page to be moved by cleaning */
973 		f2fs_wait_on_encrypted_page_writeback(sbi, blkaddr);
974 	}
975 
976 	bio = bio_alloc(GFP_KERNEL, min_t(int, nr_pages, BIO_MAX_PAGES));
977 	if (!bio) {
978 		if (ctx)
979 			fscrypt_release_ctx(ctx);
980 		return ERR_PTR(-ENOMEM);
981 	}
982 	bio->bi_bdev = bdev;
983 	bio->bi_iter.bi_sector = SECTOR_FROM_BLOCK(blkaddr);
984 	bio->bi_end_io = f2fs_read_end_io;
985 	bio->bi_private = ctx;
986 
987 	return bio;
988 }
989 
990 /*
991  * This function was originally taken from fs/mpage.c, and customized for f2fs.
992  * Major change was from block_size == page_size in f2fs by default.
993  */
994 static int f2fs_mpage_readpages(struct address_space *mapping,
995 			struct list_head *pages, struct page *page,
996 			unsigned nr_pages)
997 {
998 	struct bio *bio = NULL;
999 	unsigned page_idx;
1000 	sector_t last_block_in_bio = 0;
1001 	struct inode *inode = mapping->host;
1002 	const unsigned blkbits = inode->i_blkbits;
1003 	const unsigned blocksize = 1 << blkbits;
1004 	sector_t block_in_file;
1005 	sector_t last_block;
1006 	sector_t last_block_in_file;
1007 	sector_t block_nr;
1008 	struct f2fs_map_blocks map;
1009 
1010 	map.m_pblk = 0;
1011 	map.m_lblk = 0;
1012 	map.m_len = 0;
1013 	map.m_flags = 0;
1014 	map.m_next_pgofs = NULL;
1015 
1016 	for (page_idx = 0; nr_pages; page_idx++, nr_pages--) {
1017 
1018 		prefetchw(&page->flags);
1019 		if (pages) {
1020 			page = list_entry(pages->prev, struct page, lru);
1021 			list_del(&page->lru);
1022 			if (add_to_page_cache_lru(page, mapping,
1023 						  page->index,
1024 						  readahead_gfp_mask(mapping)))
1025 				goto next_page;
1026 		}
1027 
1028 		block_in_file = (sector_t)page->index;
1029 		last_block = block_in_file + nr_pages;
1030 		last_block_in_file = (i_size_read(inode) + blocksize - 1) >>
1031 								blkbits;
1032 		if (last_block > last_block_in_file)
1033 			last_block = last_block_in_file;
1034 
1035 		/*
1036 		 * Map blocks using the previous result first.
1037 		 */
1038 		if ((map.m_flags & F2FS_MAP_MAPPED) &&
1039 				block_in_file > map.m_lblk &&
1040 				block_in_file < (map.m_lblk + map.m_len))
1041 			goto got_it;
1042 
1043 		/*
1044 		 * Then do more f2fs_map_blocks() calls until we are
1045 		 * done with this page.
1046 		 */
1047 		map.m_flags = 0;
1048 
1049 		if (block_in_file < last_block) {
1050 			map.m_lblk = block_in_file;
1051 			map.m_len = last_block - block_in_file;
1052 
1053 			if (f2fs_map_blocks(inode, &map, 0,
1054 						F2FS_GET_BLOCK_READ))
1055 				goto set_error_page;
1056 		}
1057 got_it:
1058 		if ((map.m_flags & F2FS_MAP_MAPPED)) {
1059 			block_nr = map.m_pblk + block_in_file - map.m_lblk;
1060 			SetPageMappedToDisk(page);
1061 
1062 			if (!PageUptodate(page) && !cleancache_get_page(page)) {
1063 				SetPageUptodate(page);
1064 				goto confused;
1065 			}
1066 		} else {
1067 			zero_user_segment(page, 0, PAGE_SIZE);
1068 			if (!PageUptodate(page))
1069 				SetPageUptodate(page);
1070 			unlock_page(page);
1071 			goto next_page;
1072 		}
1073 
1074 		/*
1075 		 * This page will go to BIO.  Do we need to send this
1076 		 * BIO off first?
1077 		 */
1078 		if (bio && (last_block_in_bio != block_nr - 1)) {
1079 submit_and_realloc:
1080 			__submit_bio(F2FS_I_SB(inode), bio, DATA);
1081 			bio = NULL;
1082 		}
1083 		if (bio == NULL) {
1084 			bio = f2fs_grab_bio(inode, block_nr, nr_pages);
1085 			if (IS_ERR(bio)) {
1086 				bio = NULL;
1087 				goto set_error_page;
1088 			}
1089 			bio_set_op_attrs(bio, REQ_OP_READ, 0);
1090 		}
1091 
1092 		if (bio_add_page(bio, page, blocksize, 0) < blocksize)
1093 			goto submit_and_realloc;
1094 
1095 		last_block_in_bio = block_nr;
1096 		goto next_page;
1097 set_error_page:
1098 		SetPageError(page);
1099 		zero_user_segment(page, 0, PAGE_SIZE);
1100 		unlock_page(page);
1101 		goto next_page;
1102 confused:
1103 		if (bio) {
1104 			__submit_bio(F2FS_I_SB(inode), bio, DATA);
1105 			bio = NULL;
1106 		}
1107 		unlock_page(page);
1108 next_page:
1109 		if (pages)
1110 			put_page(page);
1111 	}
1112 	BUG_ON(pages && !list_empty(pages));
1113 	if (bio)
1114 		__submit_bio(F2FS_I_SB(inode), bio, DATA);
1115 	return 0;
1116 }
1117 
1118 static int f2fs_read_data_page(struct file *file, struct page *page)
1119 {
1120 	struct inode *inode = page->mapping->host;
1121 	int ret = -EAGAIN;
1122 
1123 	trace_f2fs_readpage(page, DATA);
1124 
1125 	/* If the file has inline data, try to read it directly */
1126 	if (f2fs_has_inline_data(inode))
1127 		ret = f2fs_read_inline_data(inode, page);
1128 	if (ret == -EAGAIN)
1129 		ret = f2fs_mpage_readpages(page->mapping, NULL, page, 1);
1130 	return ret;
1131 }
1132 
1133 static int f2fs_read_data_pages(struct file *file,
1134 			struct address_space *mapping,
1135 			struct list_head *pages, unsigned nr_pages)
1136 {
1137 	struct inode *inode = file->f_mapping->host;
1138 	struct page *page = list_entry(pages->prev, struct page, lru);
1139 
1140 	trace_f2fs_readpages(inode, page, nr_pages);
1141 
1142 	/* If the file has inline data, skip readpages */
1143 	if (f2fs_has_inline_data(inode))
1144 		return 0;
1145 
1146 	return f2fs_mpage_readpages(mapping, pages, NULL, nr_pages);
1147 }
1148 
1149 int do_write_data_page(struct f2fs_io_info *fio)
1150 {
1151 	struct page *page = fio->page;
1152 	struct inode *inode = page->mapping->host;
1153 	struct dnode_of_data dn;
1154 	int err = 0;
1155 
1156 	set_new_dnode(&dn, inode, NULL, NULL, 0);
1157 	err = get_dnode_of_data(&dn, page->index, LOOKUP_NODE);
1158 	if (err)
1159 		return err;
1160 
1161 	fio->old_blkaddr = dn.data_blkaddr;
1162 
1163 	/* This page is already truncated */
1164 	if (fio->old_blkaddr == NULL_ADDR) {
1165 		ClearPageUptodate(page);
1166 		goto out_writepage;
1167 	}
1168 
1169 	if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode)) {
1170 		gfp_t gfp_flags = GFP_NOFS;
1171 
1172 		/* wait for GCed encrypted page writeback */
1173 		f2fs_wait_on_encrypted_page_writeback(F2FS_I_SB(inode),
1174 							fio->old_blkaddr);
1175 retry_encrypt:
1176 		fio->encrypted_page = fscrypt_encrypt_page(inode, fio->page,
1177 								gfp_flags);
1178 		if (IS_ERR(fio->encrypted_page)) {
1179 			err = PTR_ERR(fio->encrypted_page);
1180 			if (err == -ENOMEM) {
1181 				/* flush pending ios and wait for a while */
1182 				f2fs_flush_merged_bios(F2FS_I_SB(inode));
1183 				congestion_wait(BLK_RW_ASYNC, HZ/50);
1184 				gfp_flags |= __GFP_NOFAIL;
1185 				err = 0;
1186 				goto retry_encrypt;
1187 			}
1188 			goto out_writepage;
1189 		}
1190 	}
1191 
1192 	set_page_writeback(page);
1193 
1194 	/*
1195 	 * If current allocation needs SSR,
1196 	 * it had better in-place writes for updated data.
1197 	 */
1198 	if (unlikely(fio->old_blkaddr != NEW_ADDR &&
1199 			!is_cold_data(page) &&
1200 			!IS_ATOMIC_WRITTEN_PAGE(page) &&
1201 			need_inplace_update(inode))) {
1202 		rewrite_data_page(fio);
1203 		set_inode_flag(inode, FI_UPDATE_WRITE);
1204 		trace_f2fs_do_write_data_page(page, IPU);
1205 	} else {
1206 		write_data_page(&dn, fio);
1207 		trace_f2fs_do_write_data_page(page, OPU);
1208 		set_inode_flag(inode, FI_APPEND_WRITE);
1209 		if (page->index == 0)
1210 			set_inode_flag(inode, FI_FIRST_BLOCK_WRITTEN);
1211 	}
1212 out_writepage:
1213 	f2fs_put_dnode(&dn);
1214 	return err;
1215 }
1216 
1217 static int f2fs_write_data_page(struct page *page,
1218 					struct writeback_control *wbc)
1219 {
1220 	struct inode *inode = page->mapping->host;
1221 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1222 	loff_t i_size = i_size_read(inode);
1223 	const pgoff_t end_index = ((unsigned long long) i_size)
1224 							>> PAGE_SHIFT;
1225 	loff_t psize = (page->index + 1) << PAGE_SHIFT;
1226 	unsigned offset = 0;
1227 	bool need_balance_fs = false;
1228 	int err = 0;
1229 	struct f2fs_io_info fio = {
1230 		.sbi = sbi,
1231 		.type = DATA,
1232 		.op = REQ_OP_WRITE,
1233 		.op_flags = (wbc->sync_mode == WB_SYNC_ALL) ? WRITE_SYNC : 0,
1234 		.page = page,
1235 		.encrypted_page = NULL,
1236 	};
1237 
1238 	trace_f2fs_writepage(page, DATA);
1239 
1240 	if (page->index < end_index)
1241 		goto write;
1242 
1243 	/*
1244 	 * If the offset is out-of-range of file size,
1245 	 * this page does not have to be written to disk.
1246 	 */
1247 	offset = i_size & (PAGE_SIZE - 1);
1248 	if ((page->index >= end_index + 1) || !offset)
1249 		goto out;
1250 
1251 	zero_user_segment(page, offset, PAGE_SIZE);
1252 write:
1253 	if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
1254 		goto redirty_out;
1255 	if (f2fs_is_drop_cache(inode))
1256 		goto out;
1257 	/* we should not write 0'th page having journal header */
1258 	if (f2fs_is_volatile_file(inode) && (!page->index ||
1259 			(!wbc->for_reclaim &&
1260 			available_free_memory(sbi, BASE_CHECK))))
1261 		goto redirty_out;
1262 
1263 	/* we should bypass data pages to proceed the kworkder jobs */
1264 	if (unlikely(f2fs_cp_error(sbi))) {
1265 		mapping_set_error(page->mapping, -EIO);
1266 		goto out;
1267 	}
1268 
1269 	/* Dentry blocks are controlled by checkpoint */
1270 	if (S_ISDIR(inode->i_mode)) {
1271 		err = do_write_data_page(&fio);
1272 		goto done;
1273 	}
1274 
1275 	if (!wbc->for_reclaim)
1276 		need_balance_fs = true;
1277 	else if (has_not_enough_free_secs(sbi, 0, 0))
1278 		goto redirty_out;
1279 
1280 	err = -EAGAIN;
1281 	f2fs_lock_op(sbi);
1282 	if (f2fs_has_inline_data(inode))
1283 		err = f2fs_write_inline_data(inode, page);
1284 	if (err == -EAGAIN)
1285 		err = do_write_data_page(&fio);
1286 	if (F2FS_I(inode)->last_disk_size < psize)
1287 		F2FS_I(inode)->last_disk_size = psize;
1288 	f2fs_unlock_op(sbi);
1289 done:
1290 	if (err && err != -ENOENT)
1291 		goto redirty_out;
1292 
1293 	clear_cold_data(page);
1294 out:
1295 	inode_dec_dirty_pages(inode);
1296 	if (err)
1297 		ClearPageUptodate(page);
1298 
1299 	if (wbc->for_reclaim) {
1300 		f2fs_submit_merged_bio_cond(sbi, NULL, page, 0, DATA, WRITE);
1301 		remove_dirty_inode(inode);
1302 	}
1303 
1304 	unlock_page(page);
1305 	f2fs_balance_fs(sbi, need_balance_fs);
1306 
1307 	if (unlikely(f2fs_cp_error(sbi)))
1308 		f2fs_submit_merged_bio(sbi, DATA, WRITE);
1309 
1310 	return 0;
1311 
1312 redirty_out:
1313 	redirty_page_for_writepage(wbc, page);
1314 	unlock_page(page);
1315 	return err;
1316 }
1317 
1318 /*
1319  * This function was copied from write_cche_pages from mm/page-writeback.c.
1320  * The major change is making write step of cold data page separately from
1321  * warm/hot data page.
1322  */
1323 static int f2fs_write_cache_pages(struct address_space *mapping,
1324 					struct writeback_control *wbc)
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 nwritten = 0;
1338 
1339 	pagevec_init(&pvec, 0);
1340 
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 (PageWriteback(page)) {
1396 				if (wbc->sync_mode != WB_SYNC_NONE)
1397 					f2fs_wait_on_page_writeback(page,
1398 								DATA, true);
1399 				else
1400 					goto continue_unlock;
1401 			}
1402 
1403 			BUG_ON(PageWriteback(page));
1404 			if (!clear_page_dirty_for_io(page))
1405 				goto continue_unlock;
1406 
1407 			ret = mapping->a_ops->writepage(page, wbc);
1408 			if (unlikely(ret)) {
1409 				done_index = page->index + 1;
1410 				done = 1;
1411 				break;
1412 			} else {
1413 				nwritten++;
1414 			}
1415 
1416 			if (--wbc->nr_to_write <= 0 &&
1417 			    wbc->sync_mode == WB_SYNC_NONE) {
1418 				done = 1;
1419 				break;
1420 			}
1421 		}
1422 		pagevec_release(&pvec);
1423 		cond_resched();
1424 	}
1425 
1426 	if (!cycled && !done) {
1427 		cycled = 1;
1428 		index = 0;
1429 		end = writeback_index - 1;
1430 		goto retry;
1431 	}
1432 	if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
1433 		mapping->writeback_index = done_index;
1434 
1435 	if (nwritten)
1436 		f2fs_submit_merged_bio_cond(F2FS_M_SB(mapping), mapping->host,
1437 							NULL, 0, DATA, WRITE);
1438 
1439 	return ret;
1440 }
1441 
1442 static int f2fs_write_data_pages(struct address_space *mapping,
1443 			    struct writeback_control *wbc)
1444 {
1445 	struct inode *inode = mapping->host;
1446 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1447 	struct blk_plug plug;
1448 	int ret;
1449 
1450 	/* deal with chardevs and other special file */
1451 	if (!mapping->a_ops->writepage)
1452 		return 0;
1453 
1454 	/* skip writing if there is no dirty page in this inode */
1455 	if (!get_dirty_pages(inode) && wbc->sync_mode == WB_SYNC_NONE)
1456 		return 0;
1457 
1458 	if (S_ISDIR(inode->i_mode) && wbc->sync_mode == WB_SYNC_NONE &&
1459 			get_dirty_pages(inode) < nr_pages_to_skip(sbi, DATA) &&
1460 			available_free_memory(sbi, DIRTY_DENTS))
1461 		goto skip_write;
1462 
1463 	/* skip writing during file defragment */
1464 	if (is_inode_flag_set(inode, FI_DO_DEFRAG))
1465 		goto skip_write;
1466 
1467 	/* during POR, we don't need to trigger writepage at all. */
1468 	if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
1469 		goto skip_write;
1470 
1471 	trace_f2fs_writepages(mapping->host, wbc, DATA);
1472 
1473 	blk_start_plug(&plug);
1474 	ret = f2fs_write_cache_pages(mapping, wbc);
1475 	blk_finish_plug(&plug);
1476 	/*
1477 	 * if some pages were truncated, we cannot guarantee its mapping->host
1478 	 * to detect pending bios.
1479 	 */
1480 
1481 	remove_dirty_inode(inode);
1482 	return ret;
1483 
1484 skip_write:
1485 	wbc->pages_skipped += get_dirty_pages(inode);
1486 	trace_f2fs_writepages(mapping->host, wbc, DATA);
1487 	return 0;
1488 }
1489 
1490 static void f2fs_write_failed(struct address_space *mapping, loff_t to)
1491 {
1492 	struct inode *inode = mapping->host;
1493 	loff_t i_size = i_size_read(inode);
1494 
1495 	if (to > i_size) {
1496 		truncate_pagecache(inode, i_size);
1497 		truncate_blocks(inode, i_size, true);
1498 	}
1499 }
1500 
1501 static int prepare_write_begin(struct f2fs_sb_info *sbi,
1502 			struct page *page, loff_t pos, unsigned len,
1503 			block_t *blk_addr, bool *node_changed)
1504 {
1505 	struct inode *inode = page->mapping->host;
1506 	pgoff_t index = page->index;
1507 	struct dnode_of_data dn;
1508 	struct page *ipage;
1509 	bool locked = false;
1510 	struct extent_info ei;
1511 	int err = 0;
1512 
1513 	/*
1514 	 * we already allocated all the blocks, so we don't need to get
1515 	 * the block addresses when there is no need to fill the page.
1516 	 */
1517 	if (!f2fs_has_inline_data(inode) && len == PAGE_SIZE)
1518 		return 0;
1519 
1520 	if (f2fs_has_inline_data(inode) ||
1521 			(pos & PAGE_MASK) >= i_size_read(inode)) {
1522 		f2fs_lock_op(sbi);
1523 		locked = true;
1524 	}
1525 restart:
1526 	/* check inline_data */
1527 	ipage = get_node_page(sbi, inode->i_ino);
1528 	if (IS_ERR(ipage)) {
1529 		err = PTR_ERR(ipage);
1530 		goto unlock_out;
1531 	}
1532 
1533 	set_new_dnode(&dn, inode, ipage, ipage, 0);
1534 
1535 	if (f2fs_has_inline_data(inode)) {
1536 		if (pos + len <= MAX_INLINE_DATA) {
1537 			read_inline_data(page, ipage);
1538 			set_inode_flag(inode, FI_DATA_EXIST);
1539 			if (inode->i_nlink)
1540 				set_inline_node(ipage);
1541 		} else {
1542 			err = f2fs_convert_inline_page(&dn, page);
1543 			if (err)
1544 				goto out;
1545 			if (dn.data_blkaddr == NULL_ADDR)
1546 				err = f2fs_get_block(&dn, index);
1547 		}
1548 	} else if (locked) {
1549 		err = f2fs_get_block(&dn, index);
1550 	} else {
1551 		if (f2fs_lookup_extent_cache(inode, index, &ei)) {
1552 			dn.data_blkaddr = ei.blk + index - ei.fofs;
1553 		} else {
1554 			/* hole case */
1555 			err = get_dnode_of_data(&dn, index, LOOKUP_NODE);
1556 			if (err || dn.data_blkaddr == NULL_ADDR) {
1557 				f2fs_put_dnode(&dn);
1558 				f2fs_lock_op(sbi);
1559 				locked = true;
1560 				goto restart;
1561 			}
1562 		}
1563 	}
1564 
1565 	/* convert_inline_page can make node_changed */
1566 	*blk_addr = dn.data_blkaddr;
1567 	*node_changed = dn.node_changed;
1568 out:
1569 	f2fs_put_dnode(&dn);
1570 unlock_out:
1571 	if (locked)
1572 		f2fs_unlock_op(sbi);
1573 	return err;
1574 }
1575 
1576 static int f2fs_write_begin(struct file *file, struct address_space *mapping,
1577 		loff_t pos, unsigned len, unsigned flags,
1578 		struct page **pagep, void **fsdata)
1579 {
1580 	struct inode *inode = mapping->host;
1581 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1582 	struct page *page = NULL;
1583 	pgoff_t index = ((unsigned long long) pos) >> PAGE_SHIFT;
1584 	bool need_balance = false;
1585 	block_t blkaddr = NULL_ADDR;
1586 	int err = 0;
1587 
1588 	trace_f2fs_write_begin(inode, pos, len, flags);
1589 
1590 	/*
1591 	 * We should check this at this moment to avoid deadlock on inode page
1592 	 * and #0 page. The locking rule for inline_data conversion should be:
1593 	 * lock_page(page #0) -> lock_page(inode_page)
1594 	 */
1595 	if (index != 0) {
1596 		err = f2fs_convert_inline_inode(inode);
1597 		if (err)
1598 			goto fail;
1599 	}
1600 repeat:
1601 	page = grab_cache_page_write_begin(mapping, index, flags);
1602 	if (!page) {
1603 		err = -ENOMEM;
1604 		goto fail;
1605 	}
1606 
1607 	*pagep = page;
1608 
1609 	err = prepare_write_begin(sbi, page, pos, len,
1610 					&blkaddr, &need_balance);
1611 	if (err)
1612 		goto fail;
1613 
1614 	if (need_balance && has_not_enough_free_secs(sbi, 0, 0)) {
1615 		unlock_page(page);
1616 		f2fs_balance_fs(sbi, true);
1617 		lock_page(page);
1618 		if (page->mapping != mapping) {
1619 			/* The page got truncated from under us */
1620 			f2fs_put_page(page, 1);
1621 			goto repeat;
1622 		}
1623 	}
1624 
1625 	f2fs_wait_on_page_writeback(page, DATA, false);
1626 
1627 	/* wait for GCed encrypted page writeback */
1628 	if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode))
1629 		f2fs_wait_on_encrypted_page_writeback(sbi, blkaddr);
1630 
1631 	if (len == PAGE_SIZE || PageUptodate(page))
1632 		return 0;
1633 
1634 	if (blkaddr == NEW_ADDR) {
1635 		zero_user_segment(page, 0, PAGE_SIZE);
1636 		SetPageUptodate(page);
1637 	} else {
1638 		struct bio *bio;
1639 
1640 		bio = f2fs_grab_bio(inode, blkaddr, 1);
1641 		if (IS_ERR(bio)) {
1642 			err = PTR_ERR(bio);
1643 			goto fail;
1644 		}
1645 		bio_set_op_attrs(bio, REQ_OP_READ, READ_SYNC);
1646 		if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
1647 			bio_put(bio);
1648 			err = -EFAULT;
1649 			goto fail;
1650 		}
1651 
1652 		__submit_bio(sbi, bio, DATA);
1653 
1654 		lock_page(page);
1655 		if (unlikely(page->mapping != mapping)) {
1656 			f2fs_put_page(page, 1);
1657 			goto repeat;
1658 		}
1659 		if (unlikely(!PageUptodate(page))) {
1660 			err = -EIO;
1661 			goto fail;
1662 		}
1663 	}
1664 	return 0;
1665 
1666 fail:
1667 	f2fs_put_page(page, 1);
1668 	f2fs_write_failed(mapping, pos + len);
1669 	return err;
1670 }
1671 
1672 static int f2fs_write_end(struct file *file,
1673 			struct address_space *mapping,
1674 			loff_t pos, unsigned len, unsigned copied,
1675 			struct page *page, void *fsdata)
1676 {
1677 	struct inode *inode = page->mapping->host;
1678 
1679 	trace_f2fs_write_end(inode, pos, len, copied);
1680 
1681 	/*
1682 	 * This should be come from len == PAGE_SIZE, and we expect copied
1683 	 * should be PAGE_SIZE. Otherwise, we treat it with zero copied and
1684 	 * let generic_perform_write() try to copy data again through copied=0.
1685 	 */
1686 	if (!PageUptodate(page)) {
1687 		if (unlikely(copied != PAGE_SIZE))
1688 			copied = 0;
1689 		else
1690 			SetPageUptodate(page);
1691 	}
1692 	if (!copied)
1693 		goto unlock_out;
1694 
1695 	set_page_dirty(page);
1696 	clear_cold_data(page);
1697 
1698 	if (pos + copied > i_size_read(inode))
1699 		f2fs_i_size_write(inode, pos + copied);
1700 unlock_out:
1701 	f2fs_put_page(page, 1);
1702 	f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
1703 	return copied;
1704 }
1705 
1706 static int check_direct_IO(struct inode *inode, struct iov_iter *iter,
1707 			   loff_t offset)
1708 {
1709 	unsigned blocksize_mask = inode->i_sb->s_blocksize - 1;
1710 
1711 	if (offset & blocksize_mask)
1712 		return -EINVAL;
1713 
1714 	if (iov_iter_alignment(iter) & blocksize_mask)
1715 		return -EINVAL;
1716 
1717 	return 0;
1718 }
1719 
1720 static ssize_t f2fs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
1721 {
1722 	struct address_space *mapping = iocb->ki_filp->f_mapping;
1723 	struct inode *inode = mapping->host;
1724 	size_t count = iov_iter_count(iter);
1725 	loff_t offset = iocb->ki_pos;
1726 	int rw = iov_iter_rw(iter);
1727 	int err;
1728 
1729 	err = check_direct_IO(inode, iter, offset);
1730 	if (err)
1731 		return err;
1732 
1733 	if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode))
1734 		return 0;
1735 	if (rw == WRITE && test_opt(F2FS_I_SB(inode), LFS))
1736 		return 0;
1737 
1738 	trace_f2fs_direct_IO_enter(inode, offset, count, rw);
1739 
1740 	down_read(&F2FS_I(inode)->dio_rwsem[rw]);
1741 	err = blockdev_direct_IO(iocb, inode, iter, get_data_block_dio);
1742 	up_read(&F2FS_I(inode)->dio_rwsem[rw]);
1743 
1744 	if (rw == WRITE) {
1745 		if (err > 0)
1746 			set_inode_flag(inode, FI_UPDATE_WRITE);
1747 		else if (err < 0)
1748 			f2fs_write_failed(mapping, offset + count);
1749 	}
1750 
1751 	trace_f2fs_direct_IO_exit(inode, offset, count, rw, err);
1752 
1753 	return err;
1754 }
1755 
1756 void f2fs_invalidate_page(struct page *page, unsigned int offset,
1757 							unsigned int length)
1758 {
1759 	struct inode *inode = page->mapping->host;
1760 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1761 
1762 	if (inode->i_ino >= F2FS_ROOT_INO(sbi) &&
1763 		(offset % PAGE_SIZE || length != PAGE_SIZE))
1764 		return;
1765 
1766 	if (PageDirty(page)) {
1767 		if (inode->i_ino == F2FS_META_INO(sbi)) {
1768 			dec_page_count(sbi, F2FS_DIRTY_META);
1769 		} else if (inode->i_ino == F2FS_NODE_INO(sbi)) {
1770 			dec_page_count(sbi, F2FS_DIRTY_NODES);
1771 		} else {
1772 			inode_dec_dirty_pages(inode);
1773 			remove_dirty_inode(inode);
1774 		}
1775 	}
1776 
1777 	/* This is atomic written page, keep Private */
1778 	if (IS_ATOMIC_WRITTEN_PAGE(page))
1779 		return;
1780 
1781 	set_page_private(page, 0);
1782 	ClearPagePrivate(page);
1783 }
1784 
1785 int f2fs_release_page(struct page *page, gfp_t wait)
1786 {
1787 	/* If this is dirty page, keep PagePrivate */
1788 	if (PageDirty(page))
1789 		return 0;
1790 
1791 	/* This is atomic written page, keep Private */
1792 	if (IS_ATOMIC_WRITTEN_PAGE(page))
1793 		return 0;
1794 
1795 	set_page_private(page, 0);
1796 	ClearPagePrivate(page);
1797 	return 1;
1798 }
1799 
1800 /*
1801  * This was copied from __set_page_dirty_buffers which gives higher performance
1802  * in very high speed storages. (e.g., pmem)
1803  */
1804 void f2fs_set_page_dirty_nobuffers(struct page *page)
1805 {
1806 	struct address_space *mapping = page->mapping;
1807 	unsigned long flags;
1808 
1809 	if (unlikely(!mapping))
1810 		return;
1811 
1812 	spin_lock(&mapping->private_lock);
1813 	lock_page_memcg(page);
1814 	SetPageDirty(page);
1815 	spin_unlock(&mapping->private_lock);
1816 
1817 	spin_lock_irqsave(&mapping->tree_lock, flags);
1818 	WARN_ON_ONCE(!PageUptodate(page));
1819 	account_page_dirtied(page, mapping);
1820 	radix_tree_tag_set(&mapping->page_tree,
1821 			page_index(page), PAGECACHE_TAG_DIRTY);
1822 	spin_unlock_irqrestore(&mapping->tree_lock, flags);
1823 	unlock_page_memcg(page);
1824 
1825 	__mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
1826 	return;
1827 }
1828 
1829 static int f2fs_set_data_page_dirty(struct page *page)
1830 {
1831 	struct address_space *mapping = page->mapping;
1832 	struct inode *inode = mapping->host;
1833 
1834 	trace_f2fs_set_page_dirty(page, DATA);
1835 
1836 	if (!PageUptodate(page))
1837 		SetPageUptodate(page);
1838 
1839 	if (f2fs_is_atomic_file(inode)) {
1840 		if (!IS_ATOMIC_WRITTEN_PAGE(page)) {
1841 			register_inmem_page(inode, page);
1842 			return 1;
1843 		}
1844 		/*
1845 		 * Previously, this page has been registered, we just
1846 		 * return here.
1847 		 */
1848 		return 0;
1849 	}
1850 
1851 	if (!PageDirty(page)) {
1852 		f2fs_set_page_dirty_nobuffers(page);
1853 		update_dirty_page(inode, page);
1854 		return 1;
1855 	}
1856 	return 0;
1857 }
1858 
1859 static sector_t f2fs_bmap(struct address_space *mapping, sector_t block)
1860 {
1861 	struct inode *inode = mapping->host;
1862 
1863 	if (f2fs_has_inline_data(inode))
1864 		return 0;
1865 
1866 	/* make sure allocating whole blocks */
1867 	if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
1868 		filemap_write_and_wait(mapping);
1869 
1870 	return generic_block_bmap(mapping, block, get_data_block_bmap);
1871 }
1872 
1873 #ifdef CONFIG_MIGRATION
1874 #include <linux/migrate.h>
1875 
1876 int f2fs_migrate_page(struct address_space *mapping,
1877 		struct page *newpage, struct page *page, enum migrate_mode mode)
1878 {
1879 	int rc, extra_count;
1880 	struct f2fs_inode_info *fi = F2FS_I(mapping->host);
1881 	bool atomic_written = IS_ATOMIC_WRITTEN_PAGE(page);
1882 
1883 	BUG_ON(PageWriteback(page));
1884 
1885 	/* migrating an atomic written page is safe with the inmem_lock hold */
1886 	if (atomic_written && !mutex_trylock(&fi->inmem_lock))
1887 		return -EAGAIN;
1888 
1889 	/*
1890 	 * A reference is expected if PagePrivate set when move mapping,
1891 	 * however F2FS breaks this for maintaining dirty page counts when
1892 	 * truncating pages. So here adjusting the 'extra_count' make it work.
1893 	 */
1894 	extra_count = (atomic_written ? 1 : 0) - page_has_private(page);
1895 	rc = migrate_page_move_mapping(mapping, newpage,
1896 				page, NULL, mode, extra_count);
1897 	if (rc != MIGRATEPAGE_SUCCESS) {
1898 		if (atomic_written)
1899 			mutex_unlock(&fi->inmem_lock);
1900 		return rc;
1901 	}
1902 
1903 	if (atomic_written) {
1904 		struct inmem_pages *cur;
1905 		list_for_each_entry(cur, &fi->inmem_pages, list)
1906 			if (cur->page == page) {
1907 				cur->page = newpage;
1908 				break;
1909 			}
1910 		mutex_unlock(&fi->inmem_lock);
1911 		put_page(page);
1912 		get_page(newpage);
1913 	}
1914 
1915 	if (PagePrivate(page))
1916 		SetPagePrivate(newpage);
1917 	set_page_private(newpage, page_private(page));
1918 
1919 	migrate_page_copy(newpage, page);
1920 
1921 	return MIGRATEPAGE_SUCCESS;
1922 }
1923 #endif
1924 
1925 const struct address_space_operations f2fs_dblock_aops = {
1926 	.readpage	= f2fs_read_data_page,
1927 	.readpages	= f2fs_read_data_pages,
1928 	.writepage	= f2fs_write_data_page,
1929 	.writepages	= f2fs_write_data_pages,
1930 	.write_begin	= f2fs_write_begin,
1931 	.write_end	= f2fs_write_end,
1932 	.set_page_dirty	= f2fs_set_data_page_dirty,
1933 	.invalidatepage	= f2fs_invalidate_page,
1934 	.releasepage	= f2fs_release_page,
1935 	.direct_IO	= f2fs_direct_IO,
1936 	.bmap		= f2fs_bmap,
1937 #ifdef CONFIG_MIGRATION
1938 	.migratepage    = f2fs_migrate_page,
1939 #endif
1940 };
1941