xref: /linux/fs/f2fs/data.c (revision 6ea76f33e9ab99c7888547e1acba2baf8e4b5b17)
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_hmsmr(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 		io->fio.op_flags = REQ_PREFLUSH | REQ_META | REQ_PRIO;
202 		if (!test_opt(sbi, NOBARRIER))
203 			io->fio.op_flags |= REQ_FUA;
204 	}
205 	__submit_merged_bio(io);
206 out:
207 	up_write(&io->io_rwsem);
208 }
209 
210 void f2fs_submit_merged_bio(struct f2fs_sb_info *sbi, enum page_type type,
211 									int rw)
212 {
213 	__f2fs_submit_merged_bio(sbi, NULL, NULL, 0, type, rw);
214 }
215 
216 void f2fs_submit_merged_bio_cond(struct f2fs_sb_info *sbi,
217 				struct inode *inode, struct page *page,
218 				nid_t ino, enum page_type type, int rw)
219 {
220 	if (has_merged_page(sbi, inode, page, ino, type))
221 		__f2fs_submit_merged_bio(sbi, inode, page, ino, type, rw);
222 }
223 
224 void f2fs_flush_merged_bios(struct f2fs_sb_info *sbi)
225 {
226 	f2fs_submit_merged_bio(sbi, DATA, WRITE);
227 	f2fs_submit_merged_bio(sbi, NODE, WRITE);
228 	f2fs_submit_merged_bio(sbi, META, WRITE);
229 }
230 
231 /*
232  * Fill the locked page with data located in the block address.
233  * Return unlocked page.
234  */
235 int f2fs_submit_page_bio(struct f2fs_io_info *fio)
236 {
237 	struct bio *bio;
238 	struct page *page = fio->encrypted_page ?
239 			fio->encrypted_page : fio->page;
240 
241 	trace_f2fs_submit_page_bio(page, fio);
242 	f2fs_trace_ios(fio, 0);
243 
244 	/* Allocate a new bio */
245 	bio = __bio_alloc(fio->sbi, fio->new_blkaddr, 1, is_read_io(fio->op));
246 
247 	if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
248 		bio_put(bio);
249 		return -EFAULT;
250 	}
251 	bio_set_op_attrs(bio, fio->op, fio->op_flags);
252 
253 	__submit_bio(fio->sbi, bio, fio->type);
254 	return 0;
255 }
256 
257 void f2fs_submit_page_mbio(struct f2fs_io_info *fio)
258 {
259 	struct f2fs_sb_info *sbi = fio->sbi;
260 	enum page_type btype = PAGE_TYPE_OF_BIO(fio->type);
261 	struct f2fs_bio_info *io;
262 	bool is_read = is_read_io(fio->op);
263 	struct page *bio_page;
264 
265 	io = is_read ? &sbi->read_io : &sbi->write_io[btype];
266 
267 	if (fio->old_blkaddr != NEW_ADDR)
268 		verify_block_addr(sbi, fio->old_blkaddr);
269 	verify_block_addr(sbi, fio->new_blkaddr);
270 
271 	down_write(&io->io_rwsem);
272 
273 	if (io->bio && (io->last_block_in_bio != fio->new_blkaddr - 1 ||
274 	    (io->fio.op != fio->op || io->fio.op_flags != fio->op_flags)))
275 		__submit_merged_bio(io);
276 alloc_new:
277 	if (io->bio == NULL) {
278 		int bio_blocks = MAX_BIO_BLOCKS(sbi);
279 
280 		io->bio = __bio_alloc(sbi, fio->new_blkaddr,
281 						bio_blocks, 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, 0, 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, 0, 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 	int seg = CURSEG_WARM_DATA;
592 	pgoff_t fofs;
593 	blkcnt_t count = 1;
594 
595 	if (unlikely(is_inode_flag_set(dn->inode, FI_NO_ALLOC)))
596 		return -EPERM;
597 
598 	dn->data_blkaddr = datablock_addr(dn->node_page, dn->ofs_in_node);
599 	if (dn->data_blkaddr == NEW_ADDR)
600 		goto alloc;
601 
602 	if (unlikely(!inc_valid_block_count(sbi, dn->inode, &count)))
603 		return -ENOSPC;
604 
605 alloc:
606 	get_node_info(sbi, dn->nid, &ni);
607 	set_summary(&sum, dn->nid, dn->ofs_in_node, ni.version);
608 
609 	if (dn->ofs_in_node == 0 && dn->inode_page == dn->node_page)
610 		seg = CURSEG_DIRECT_IO;
611 
612 	allocate_data_block(sbi, NULL, dn->data_blkaddr, &dn->data_blkaddr,
613 								&sum, seg);
614 	set_data_blkaddr(dn);
615 
616 	/* update i_size */
617 	fofs = start_bidx_of_node(ofs_of_node(dn->node_page), dn->inode) +
618 							dn->ofs_in_node;
619 	if (i_size_read(dn->inode) < ((loff_t)(fofs + 1) << PAGE_SHIFT))
620 		f2fs_i_size_write(dn->inode,
621 				((loff_t)(fofs + 1) << PAGE_SHIFT));
622 	return 0;
623 }
624 
625 ssize_t f2fs_preallocate_blocks(struct kiocb *iocb, struct iov_iter *from)
626 {
627 	struct inode *inode = file_inode(iocb->ki_filp);
628 	struct f2fs_map_blocks map;
629 	ssize_t ret = 0;
630 
631 	map.m_lblk = F2FS_BLK_ALIGN(iocb->ki_pos);
632 	map.m_len = F2FS_BYTES_TO_BLK(iocb->ki_pos + iov_iter_count(from));
633 	if (map.m_len > map.m_lblk)
634 		map.m_len -= map.m_lblk;
635 	else
636 		map.m_len = 0;
637 
638 	map.m_next_pgofs = NULL;
639 
640 	if (iocb->ki_flags & IOCB_DIRECT) {
641 		ret = f2fs_convert_inline_inode(inode);
642 		if (ret)
643 			return ret;
644 		return f2fs_map_blocks(inode, &map, 1, F2FS_GET_BLOCK_PRE_DIO);
645 	}
646 	if (iocb->ki_pos + iov_iter_count(from) > MAX_INLINE_DATA) {
647 		ret = f2fs_convert_inline_inode(inode);
648 		if (ret)
649 			return ret;
650 	}
651 	if (!f2fs_has_inline_data(inode))
652 		return f2fs_map_blocks(inode, &map, 1, F2FS_GET_BLOCK_PRE_AIO);
653 	return ret;
654 }
655 
656 /*
657  * f2fs_map_blocks() now supported readahead/bmap/rw direct_IO with
658  * f2fs_map_blocks structure.
659  * If original data blocks are allocated, then give them to blockdev.
660  * Otherwise,
661  *     a. preallocate requested block addresses
662  *     b. do not use extent cache for better performance
663  *     c. give the block addresses to blockdev
664  */
665 int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map,
666 						int create, int flag)
667 {
668 	unsigned int maxblocks = map->m_len;
669 	struct dnode_of_data dn;
670 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
671 	int mode = create ? ALLOC_NODE : LOOKUP_NODE;
672 	pgoff_t pgofs, end_offset, end;
673 	int err = 0, ofs = 1;
674 	unsigned int ofs_in_node, last_ofs_in_node;
675 	blkcnt_t prealloc;
676 	struct extent_info ei;
677 	bool allocated = false;
678 	block_t blkaddr;
679 
680 	if (!maxblocks)
681 		return 0;
682 
683 	map->m_len = 0;
684 	map->m_flags = 0;
685 
686 	/* it only supports block size == page size */
687 	pgofs =	(pgoff_t)map->m_lblk;
688 	end = pgofs + maxblocks;
689 
690 	if (!create && f2fs_lookup_extent_cache(inode, pgofs, &ei)) {
691 		map->m_pblk = ei.blk + pgofs - ei.fofs;
692 		map->m_len = min((pgoff_t)maxblocks, ei.fofs + ei.len - pgofs);
693 		map->m_flags = F2FS_MAP_MAPPED;
694 		goto out;
695 	}
696 
697 next_dnode:
698 	if (create)
699 		f2fs_lock_op(sbi);
700 
701 	/* When reading holes, we need its node page */
702 	set_new_dnode(&dn, inode, NULL, NULL, 0);
703 	err = get_dnode_of_data(&dn, pgofs, mode);
704 	if (err) {
705 		if (flag == F2FS_GET_BLOCK_BMAP)
706 			map->m_pblk = 0;
707 		if (err == -ENOENT) {
708 			err = 0;
709 			if (map->m_next_pgofs)
710 				*map->m_next_pgofs =
711 					get_next_page_offset(&dn, pgofs);
712 		}
713 		goto unlock_out;
714 	}
715 
716 	prealloc = 0;
717 	ofs_in_node = dn.ofs_in_node;
718 	end_offset = ADDRS_PER_PAGE(dn.node_page, inode);
719 
720 next_block:
721 	blkaddr = datablock_addr(dn.node_page, dn.ofs_in_node);
722 
723 	if (blkaddr == NEW_ADDR || blkaddr == NULL_ADDR) {
724 		if (create) {
725 			if (unlikely(f2fs_cp_error(sbi))) {
726 				err = -EIO;
727 				goto sync_out;
728 			}
729 			if (flag == F2FS_GET_BLOCK_PRE_AIO) {
730 				if (blkaddr == NULL_ADDR) {
731 					prealloc++;
732 					last_ofs_in_node = dn.ofs_in_node;
733 				}
734 			} else {
735 				err = __allocate_data_block(&dn);
736 				if (!err) {
737 					set_inode_flag(inode, FI_APPEND_WRITE);
738 					allocated = true;
739 				}
740 			}
741 			if (err)
742 				goto sync_out;
743 			map->m_flags = F2FS_MAP_NEW;
744 			blkaddr = dn.data_blkaddr;
745 		} else {
746 			if (flag == F2FS_GET_BLOCK_BMAP) {
747 				map->m_pblk = 0;
748 				goto sync_out;
749 			}
750 			if (flag == F2FS_GET_BLOCK_FIEMAP &&
751 						blkaddr == NULL_ADDR) {
752 				if (map->m_next_pgofs)
753 					*map->m_next_pgofs = pgofs + 1;
754 			}
755 			if (flag != F2FS_GET_BLOCK_FIEMAP ||
756 						blkaddr != NEW_ADDR)
757 				goto sync_out;
758 		}
759 	}
760 
761 	if (flag == F2FS_GET_BLOCK_PRE_AIO)
762 		goto skip;
763 
764 	if (map->m_len == 0) {
765 		/* preallocated unwritten block should be mapped for fiemap. */
766 		if (blkaddr == NEW_ADDR)
767 			map->m_flags |= F2FS_MAP_UNWRITTEN;
768 		map->m_flags |= F2FS_MAP_MAPPED;
769 
770 		map->m_pblk = blkaddr;
771 		map->m_len = 1;
772 	} else if ((map->m_pblk != NEW_ADDR &&
773 			blkaddr == (map->m_pblk + ofs)) ||
774 			(map->m_pblk == NEW_ADDR && blkaddr == NEW_ADDR) ||
775 			flag == F2FS_GET_BLOCK_PRE_DIO) {
776 		ofs++;
777 		map->m_len++;
778 	} else {
779 		goto sync_out;
780 	}
781 
782 skip:
783 	dn.ofs_in_node++;
784 	pgofs++;
785 
786 	/* preallocate blocks in batch for one dnode page */
787 	if (flag == F2FS_GET_BLOCK_PRE_AIO &&
788 			(pgofs == end || dn.ofs_in_node == end_offset)) {
789 
790 		dn.ofs_in_node = ofs_in_node;
791 		err = reserve_new_blocks(&dn, prealloc);
792 		if (err)
793 			goto sync_out;
794 		allocated = dn.node_changed;
795 
796 		map->m_len += dn.ofs_in_node - ofs_in_node;
797 		if (prealloc && dn.ofs_in_node != last_ofs_in_node + 1) {
798 			err = -ENOSPC;
799 			goto sync_out;
800 		}
801 		dn.ofs_in_node = end_offset;
802 	}
803 
804 	if (pgofs >= end)
805 		goto sync_out;
806 	else if (dn.ofs_in_node < end_offset)
807 		goto next_block;
808 
809 	f2fs_put_dnode(&dn);
810 
811 	if (create) {
812 		f2fs_unlock_op(sbi);
813 		f2fs_balance_fs(sbi, allocated);
814 	}
815 	allocated = false;
816 	goto next_dnode;
817 
818 sync_out:
819 	f2fs_put_dnode(&dn);
820 unlock_out:
821 	if (create) {
822 		f2fs_unlock_op(sbi);
823 		f2fs_balance_fs(sbi, allocated);
824 	}
825 out:
826 	trace_f2fs_map_blocks(inode, map, err);
827 	return err;
828 }
829 
830 static int __get_data_block(struct inode *inode, sector_t iblock,
831 			struct buffer_head *bh, int create, int flag,
832 			pgoff_t *next_pgofs)
833 {
834 	struct f2fs_map_blocks map;
835 	int ret;
836 
837 	map.m_lblk = iblock;
838 	map.m_len = bh->b_size >> inode->i_blkbits;
839 	map.m_next_pgofs = next_pgofs;
840 
841 	ret = f2fs_map_blocks(inode, &map, create, flag);
842 	if (!ret) {
843 		map_bh(bh, inode->i_sb, map.m_pblk);
844 		bh->b_state = (bh->b_state & ~F2FS_MAP_FLAGS) | map.m_flags;
845 		bh->b_size = map.m_len << inode->i_blkbits;
846 	}
847 	return ret;
848 }
849 
850 static int get_data_block(struct inode *inode, sector_t iblock,
851 			struct buffer_head *bh_result, int create, int flag,
852 			pgoff_t *next_pgofs)
853 {
854 	return __get_data_block(inode, iblock, bh_result, create,
855 							flag, next_pgofs);
856 }
857 
858 static int get_data_block_dio(struct inode *inode, sector_t iblock,
859 			struct buffer_head *bh_result, int create)
860 {
861 	return __get_data_block(inode, iblock, bh_result, create,
862 						F2FS_GET_BLOCK_DIO, NULL);
863 }
864 
865 static int get_data_block_bmap(struct inode *inode, sector_t iblock,
866 			struct buffer_head *bh_result, int create)
867 {
868 	/* Block number less than F2FS MAX BLOCKS */
869 	if (unlikely(iblock >= F2FS_I_SB(inode)->max_file_blocks))
870 		return -EFBIG;
871 
872 	return __get_data_block(inode, iblock, bh_result, create,
873 						F2FS_GET_BLOCK_BMAP, NULL);
874 }
875 
876 static inline sector_t logical_to_blk(struct inode *inode, loff_t offset)
877 {
878 	return (offset >> inode->i_blkbits);
879 }
880 
881 static inline loff_t blk_to_logical(struct inode *inode, sector_t blk)
882 {
883 	return (blk << inode->i_blkbits);
884 }
885 
886 int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
887 		u64 start, u64 len)
888 {
889 	struct buffer_head map_bh;
890 	sector_t start_blk, last_blk;
891 	pgoff_t next_pgofs;
892 	loff_t isize;
893 	u64 logical = 0, phys = 0, size = 0;
894 	u32 flags = 0;
895 	int ret = 0;
896 
897 	ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC);
898 	if (ret)
899 		return ret;
900 
901 	if (f2fs_has_inline_data(inode)) {
902 		ret = f2fs_inline_data_fiemap(inode, fieinfo, start, len);
903 		if (ret != -EAGAIN)
904 			return ret;
905 	}
906 
907 	inode_lock(inode);
908 
909 	isize = i_size_read(inode);
910 	if (start >= isize)
911 		goto out;
912 
913 	if (start + len > isize)
914 		len = isize - start;
915 
916 	if (logical_to_blk(inode, len) == 0)
917 		len = blk_to_logical(inode, 1);
918 
919 	start_blk = logical_to_blk(inode, start);
920 	last_blk = logical_to_blk(inode, start + len - 1);
921 
922 next:
923 	memset(&map_bh, 0, sizeof(struct buffer_head));
924 	map_bh.b_size = len;
925 
926 	ret = get_data_block(inode, start_blk, &map_bh, 0,
927 					F2FS_GET_BLOCK_FIEMAP, &next_pgofs);
928 	if (ret)
929 		goto out;
930 
931 	/* HOLE */
932 	if (!buffer_mapped(&map_bh)) {
933 		start_blk = next_pgofs;
934 		/* Go through holes util pass the EOF */
935 		if (blk_to_logical(inode, start_blk) < isize)
936 			goto prep_next;
937 		/* Found a hole beyond isize means no more extents.
938 		 * Note that the premise is that filesystems don't
939 		 * punch holes beyond isize and keep size unchanged.
940 		 */
941 		flags |= FIEMAP_EXTENT_LAST;
942 	}
943 
944 	if (size) {
945 		if (f2fs_encrypted_inode(inode))
946 			flags |= FIEMAP_EXTENT_DATA_ENCRYPTED;
947 
948 		ret = fiemap_fill_next_extent(fieinfo, logical,
949 				phys, size, flags);
950 	}
951 
952 	if (start_blk > last_blk || ret)
953 		goto out;
954 
955 	logical = blk_to_logical(inode, start_blk);
956 	phys = blk_to_logical(inode, map_bh.b_blocknr);
957 	size = map_bh.b_size;
958 	flags = 0;
959 	if (buffer_unwritten(&map_bh))
960 		flags = FIEMAP_EXTENT_UNWRITTEN;
961 
962 	start_blk += logical_to_blk(inode, size);
963 
964 prep_next:
965 	cond_resched();
966 	if (fatal_signal_pending(current))
967 		ret = -EINTR;
968 	else
969 		goto next;
970 out:
971 	if (ret == 1)
972 		ret = 0;
973 
974 	inode_unlock(inode);
975 	return ret;
976 }
977 
978 static struct bio *f2fs_grab_bio(struct inode *inode, block_t blkaddr,
979 				 unsigned nr_pages)
980 {
981 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
982 	struct fscrypt_ctx *ctx = NULL;
983 	struct block_device *bdev = sbi->sb->s_bdev;
984 	struct bio *bio;
985 
986 	if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode)) {
987 		ctx = fscrypt_get_ctx(inode, GFP_NOFS);
988 		if (IS_ERR(ctx))
989 			return ERR_CAST(ctx);
990 
991 		/* wait the page to be moved by cleaning */
992 		f2fs_wait_on_encrypted_page_writeback(sbi, blkaddr);
993 	}
994 
995 	bio = bio_alloc(GFP_KERNEL, min_t(int, nr_pages, BIO_MAX_PAGES));
996 	if (!bio) {
997 		if (ctx)
998 			fscrypt_release_ctx(ctx);
999 		return ERR_PTR(-ENOMEM);
1000 	}
1001 	bio->bi_bdev = bdev;
1002 	bio->bi_iter.bi_sector = SECTOR_FROM_BLOCK(blkaddr);
1003 	bio->bi_end_io = f2fs_read_end_io;
1004 	bio->bi_private = ctx;
1005 
1006 	return bio;
1007 }
1008 
1009 /*
1010  * This function was originally taken from fs/mpage.c, and customized for f2fs.
1011  * Major change was from block_size == page_size in f2fs by default.
1012  */
1013 static int f2fs_mpage_readpages(struct address_space *mapping,
1014 			struct list_head *pages, struct page *page,
1015 			unsigned nr_pages)
1016 {
1017 	struct bio *bio = NULL;
1018 	unsigned page_idx;
1019 	sector_t last_block_in_bio = 0;
1020 	struct inode *inode = mapping->host;
1021 	const unsigned blkbits = inode->i_blkbits;
1022 	const unsigned blocksize = 1 << blkbits;
1023 	sector_t block_in_file;
1024 	sector_t last_block;
1025 	sector_t last_block_in_file;
1026 	sector_t block_nr;
1027 	struct f2fs_map_blocks map;
1028 
1029 	map.m_pblk = 0;
1030 	map.m_lblk = 0;
1031 	map.m_len = 0;
1032 	map.m_flags = 0;
1033 	map.m_next_pgofs = NULL;
1034 
1035 	for (page_idx = 0; nr_pages; page_idx++, nr_pages--) {
1036 
1037 		prefetchw(&page->flags);
1038 		if (pages) {
1039 			page = list_entry(pages->prev, struct page, lru);
1040 			list_del(&page->lru);
1041 			if (add_to_page_cache_lru(page, mapping,
1042 						  page->index,
1043 						  readahead_gfp_mask(mapping)))
1044 				goto next_page;
1045 		}
1046 
1047 		block_in_file = (sector_t)page->index;
1048 		last_block = block_in_file + nr_pages;
1049 		last_block_in_file = (i_size_read(inode) + blocksize - 1) >>
1050 								blkbits;
1051 		if (last_block > last_block_in_file)
1052 			last_block = last_block_in_file;
1053 
1054 		/*
1055 		 * Map blocks using the previous result first.
1056 		 */
1057 		if ((map.m_flags & F2FS_MAP_MAPPED) &&
1058 				block_in_file > map.m_lblk &&
1059 				block_in_file < (map.m_lblk + map.m_len))
1060 			goto got_it;
1061 
1062 		/*
1063 		 * Then do more f2fs_map_blocks() calls until we are
1064 		 * done with this page.
1065 		 */
1066 		map.m_flags = 0;
1067 
1068 		if (block_in_file < last_block) {
1069 			map.m_lblk = block_in_file;
1070 			map.m_len = last_block - block_in_file;
1071 
1072 			if (f2fs_map_blocks(inode, &map, 0,
1073 						F2FS_GET_BLOCK_READ))
1074 				goto set_error_page;
1075 		}
1076 got_it:
1077 		if ((map.m_flags & F2FS_MAP_MAPPED)) {
1078 			block_nr = map.m_pblk + block_in_file - map.m_lblk;
1079 			SetPageMappedToDisk(page);
1080 
1081 			if (!PageUptodate(page) && !cleancache_get_page(page)) {
1082 				SetPageUptodate(page);
1083 				goto confused;
1084 			}
1085 		} else {
1086 			zero_user_segment(page, 0, PAGE_SIZE);
1087 			if (!PageUptodate(page))
1088 				SetPageUptodate(page);
1089 			unlock_page(page);
1090 			goto next_page;
1091 		}
1092 
1093 		/*
1094 		 * This page will go to BIO.  Do we need to send this
1095 		 * BIO off first?
1096 		 */
1097 		if (bio && (last_block_in_bio != block_nr - 1)) {
1098 submit_and_realloc:
1099 			__submit_bio(F2FS_I_SB(inode), bio, DATA);
1100 			bio = NULL;
1101 		}
1102 		if (bio == NULL) {
1103 			bio = f2fs_grab_bio(inode, block_nr, nr_pages);
1104 			if (IS_ERR(bio)) {
1105 				bio = NULL;
1106 				goto set_error_page;
1107 			}
1108 			bio_set_op_attrs(bio, REQ_OP_READ, 0);
1109 		}
1110 
1111 		if (bio_add_page(bio, page, blocksize, 0) < blocksize)
1112 			goto submit_and_realloc;
1113 
1114 		last_block_in_bio = block_nr;
1115 		goto next_page;
1116 set_error_page:
1117 		SetPageError(page);
1118 		zero_user_segment(page, 0, PAGE_SIZE);
1119 		unlock_page(page);
1120 		goto next_page;
1121 confused:
1122 		if (bio) {
1123 			__submit_bio(F2FS_I_SB(inode), bio, DATA);
1124 			bio = NULL;
1125 		}
1126 		unlock_page(page);
1127 next_page:
1128 		if (pages)
1129 			put_page(page);
1130 	}
1131 	BUG_ON(pages && !list_empty(pages));
1132 	if (bio)
1133 		__submit_bio(F2FS_I_SB(inode), bio, DATA);
1134 	return 0;
1135 }
1136 
1137 static int f2fs_read_data_page(struct file *file, struct page *page)
1138 {
1139 	struct inode *inode = page->mapping->host;
1140 	int ret = -EAGAIN;
1141 
1142 	trace_f2fs_readpage(page, DATA);
1143 
1144 	/* If the file has inline data, try to read it directly */
1145 	if (f2fs_has_inline_data(inode))
1146 		ret = f2fs_read_inline_data(inode, page);
1147 	if (ret == -EAGAIN)
1148 		ret = f2fs_mpage_readpages(page->mapping, NULL, page, 1);
1149 	return ret;
1150 }
1151 
1152 static int f2fs_read_data_pages(struct file *file,
1153 			struct address_space *mapping,
1154 			struct list_head *pages, unsigned nr_pages)
1155 {
1156 	struct inode *inode = file->f_mapping->host;
1157 	struct page *page = list_entry(pages->prev, struct page, lru);
1158 
1159 	trace_f2fs_readpages(inode, page, nr_pages);
1160 
1161 	/* If the file has inline data, skip readpages */
1162 	if (f2fs_has_inline_data(inode))
1163 		return 0;
1164 
1165 	return f2fs_mpage_readpages(mapping, pages, NULL, nr_pages);
1166 }
1167 
1168 int do_write_data_page(struct f2fs_io_info *fio)
1169 {
1170 	struct page *page = fio->page;
1171 	struct inode *inode = page->mapping->host;
1172 	struct dnode_of_data dn;
1173 	int err = 0;
1174 
1175 	set_new_dnode(&dn, inode, NULL, NULL, 0);
1176 	err = get_dnode_of_data(&dn, page->index, LOOKUP_NODE);
1177 	if (err)
1178 		return err;
1179 
1180 	fio->old_blkaddr = dn.data_blkaddr;
1181 
1182 	/* This page is already truncated */
1183 	if (fio->old_blkaddr == NULL_ADDR) {
1184 		ClearPageUptodate(page);
1185 		goto out_writepage;
1186 	}
1187 
1188 	if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode)) {
1189 		gfp_t gfp_flags = GFP_NOFS;
1190 
1191 		/* wait for GCed encrypted page writeback */
1192 		f2fs_wait_on_encrypted_page_writeback(F2FS_I_SB(inode),
1193 							fio->old_blkaddr);
1194 retry_encrypt:
1195 		fio->encrypted_page = fscrypt_encrypt_page(inode, fio->page,
1196 								gfp_flags);
1197 		if (IS_ERR(fio->encrypted_page)) {
1198 			err = PTR_ERR(fio->encrypted_page);
1199 			if (err == -ENOMEM) {
1200 				/* flush pending ios and wait for a while */
1201 				f2fs_flush_merged_bios(F2FS_I_SB(inode));
1202 				congestion_wait(BLK_RW_ASYNC, HZ/50);
1203 				gfp_flags |= __GFP_NOFAIL;
1204 				err = 0;
1205 				goto retry_encrypt;
1206 			}
1207 			goto out_writepage;
1208 		}
1209 	}
1210 
1211 	set_page_writeback(page);
1212 
1213 	/*
1214 	 * If current allocation needs SSR,
1215 	 * it had better in-place writes for updated data.
1216 	 */
1217 	if (unlikely(fio->old_blkaddr != NEW_ADDR &&
1218 			!is_cold_data(page) &&
1219 			!IS_ATOMIC_WRITTEN_PAGE(page) &&
1220 			need_inplace_update(inode))) {
1221 		rewrite_data_page(fio);
1222 		set_inode_flag(inode, FI_UPDATE_WRITE);
1223 		trace_f2fs_do_write_data_page(page, IPU);
1224 	} else {
1225 		write_data_page(&dn, fio);
1226 		trace_f2fs_do_write_data_page(page, OPU);
1227 		set_inode_flag(inode, FI_APPEND_WRITE);
1228 		if (page->index == 0)
1229 			set_inode_flag(inode, FI_FIRST_BLOCK_WRITTEN);
1230 	}
1231 out_writepage:
1232 	f2fs_put_dnode(&dn);
1233 	return err;
1234 }
1235 
1236 static int f2fs_write_data_page(struct page *page,
1237 					struct writeback_control *wbc)
1238 {
1239 	struct inode *inode = page->mapping->host;
1240 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1241 	loff_t i_size = i_size_read(inode);
1242 	const pgoff_t end_index = ((unsigned long long) i_size)
1243 							>> PAGE_SHIFT;
1244 	loff_t psize = (page->index + 1) << PAGE_SHIFT;
1245 	unsigned offset = 0;
1246 	bool need_balance_fs = false;
1247 	int err = 0;
1248 	struct f2fs_io_info fio = {
1249 		.sbi = sbi,
1250 		.type = DATA,
1251 		.op = REQ_OP_WRITE,
1252 		.op_flags = wbc_to_write_flags(wbc),
1253 		.page = page,
1254 		.encrypted_page = NULL,
1255 	};
1256 
1257 	trace_f2fs_writepage(page, DATA);
1258 
1259 	if (page->index < end_index)
1260 		goto write;
1261 
1262 	/*
1263 	 * If the offset is out-of-range of file size,
1264 	 * this page does not have to be written to disk.
1265 	 */
1266 	offset = i_size & (PAGE_SIZE - 1);
1267 	if ((page->index >= end_index + 1) || !offset)
1268 		goto out;
1269 
1270 	zero_user_segment(page, offset, PAGE_SIZE);
1271 write:
1272 	if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
1273 		goto redirty_out;
1274 	if (f2fs_is_drop_cache(inode))
1275 		goto out;
1276 	/* we should not write 0'th page having journal header */
1277 	if (f2fs_is_volatile_file(inode) && (!page->index ||
1278 			(!wbc->for_reclaim &&
1279 			available_free_memory(sbi, BASE_CHECK))))
1280 		goto redirty_out;
1281 
1282 	/* we should bypass data pages to proceed the kworkder jobs */
1283 	if (unlikely(f2fs_cp_error(sbi))) {
1284 		mapping_set_error(page->mapping, -EIO);
1285 		goto out;
1286 	}
1287 
1288 	/* Dentry blocks are controlled by checkpoint */
1289 	if (S_ISDIR(inode->i_mode)) {
1290 		err = do_write_data_page(&fio);
1291 		goto done;
1292 	}
1293 
1294 	if (!wbc->for_reclaim)
1295 		need_balance_fs = true;
1296 	else if (has_not_enough_free_secs(sbi, 0, 0))
1297 		goto redirty_out;
1298 
1299 	err = -EAGAIN;
1300 	f2fs_lock_op(sbi);
1301 	if (f2fs_has_inline_data(inode))
1302 		err = f2fs_write_inline_data(inode, page);
1303 	if (err == -EAGAIN)
1304 		err = do_write_data_page(&fio);
1305 	if (F2FS_I(inode)->last_disk_size < psize)
1306 		F2FS_I(inode)->last_disk_size = psize;
1307 	f2fs_unlock_op(sbi);
1308 done:
1309 	if (err && err != -ENOENT)
1310 		goto redirty_out;
1311 
1312 	clear_cold_data(page);
1313 out:
1314 	inode_dec_dirty_pages(inode);
1315 	if (err)
1316 		ClearPageUptodate(page);
1317 
1318 	if (wbc->for_reclaim) {
1319 		f2fs_submit_merged_bio_cond(sbi, NULL, page, 0, DATA, WRITE);
1320 		remove_dirty_inode(inode);
1321 	}
1322 
1323 	unlock_page(page);
1324 	f2fs_balance_fs(sbi, need_balance_fs);
1325 
1326 	if (unlikely(f2fs_cp_error(sbi)))
1327 		f2fs_submit_merged_bio(sbi, DATA, WRITE);
1328 
1329 	return 0;
1330 
1331 redirty_out:
1332 	redirty_page_for_writepage(wbc, page);
1333 	unlock_page(page);
1334 	return err;
1335 }
1336 
1337 /*
1338  * This function was copied from write_cche_pages from mm/page-writeback.c.
1339  * The major change is making write step of cold data page separately from
1340  * warm/hot data page.
1341  */
1342 static int f2fs_write_cache_pages(struct address_space *mapping,
1343 					struct writeback_control *wbc)
1344 {
1345 	int ret = 0;
1346 	int done = 0;
1347 	struct pagevec pvec;
1348 	int nr_pages;
1349 	pgoff_t uninitialized_var(writeback_index);
1350 	pgoff_t index;
1351 	pgoff_t end;		/* Inclusive */
1352 	pgoff_t done_index;
1353 	int cycled;
1354 	int range_whole = 0;
1355 	int tag;
1356 	int nwritten = 0;
1357 
1358 	pagevec_init(&pvec, 0);
1359 
1360 	if (wbc->range_cyclic) {
1361 		writeback_index = mapping->writeback_index; /* prev offset */
1362 		index = writeback_index;
1363 		if (index == 0)
1364 			cycled = 1;
1365 		else
1366 			cycled = 0;
1367 		end = -1;
1368 	} else {
1369 		index = wbc->range_start >> PAGE_SHIFT;
1370 		end = wbc->range_end >> PAGE_SHIFT;
1371 		if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
1372 			range_whole = 1;
1373 		cycled = 1; /* ignore range_cyclic tests */
1374 	}
1375 	if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
1376 		tag = PAGECACHE_TAG_TOWRITE;
1377 	else
1378 		tag = PAGECACHE_TAG_DIRTY;
1379 retry:
1380 	if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
1381 		tag_pages_for_writeback(mapping, index, end);
1382 	done_index = index;
1383 	while (!done && (index <= end)) {
1384 		int i;
1385 
1386 		nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
1387 			      min(end - index, (pgoff_t)PAGEVEC_SIZE - 1) + 1);
1388 		if (nr_pages == 0)
1389 			break;
1390 
1391 		for (i = 0; i < nr_pages; i++) {
1392 			struct page *page = pvec.pages[i];
1393 
1394 			if (page->index > end) {
1395 				done = 1;
1396 				break;
1397 			}
1398 
1399 			done_index = page->index;
1400 
1401 			lock_page(page);
1402 
1403 			if (unlikely(page->mapping != mapping)) {
1404 continue_unlock:
1405 				unlock_page(page);
1406 				continue;
1407 			}
1408 
1409 			if (!PageDirty(page)) {
1410 				/* someone wrote it for us */
1411 				goto continue_unlock;
1412 			}
1413 
1414 			if (PageWriteback(page)) {
1415 				if (wbc->sync_mode != WB_SYNC_NONE)
1416 					f2fs_wait_on_page_writeback(page,
1417 								DATA, true);
1418 				else
1419 					goto continue_unlock;
1420 			}
1421 
1422 			BUG_ON(PageWriteback(page));
1423 			if (!clear_page_dirty_for_io(page))
1424 				goto continue_unlock;
1425 
1426 			ret = mapping->a_ops->writepage(page, wbc);
1427 			if (unlikely(ret)) {
1428 				done_index = page->index + 1;
1429 				done = 1;
1430 				break;
1431 			} else {
1432 				nwritten++;
1433 			}
1434 
1435 			if (--wbc->nr_to_write <= 0 &&
1436 			    wbc->sync_mode == WB_SYNC_NONE) {
1437 				done = 1;
1438 				break;
1439 			}
1440 		}
1441 		pagevec_release(&pvec);
1442 		cond_resched();
1443 	}
1444 
1445 	if (!cycled && !done) {
1446 		cycled = 1;
1447 		index = 0;
1448 		end = writeback_index - 1;
1449 		goto retry;
1450 	}
1451 	if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
1452 		mapping->writeback_index = done_index;
1453 
1454 	if (nwritten)
1455 		f2fs_submit_merged_bio_cond(F2FS_M_SB(mapping), mapping->host,
1456 							NULL, 0, DATA, WRITE);
1457 
1458 	return ret;
1459 }
1460 
1461 static int f2fs_write_data_pages(struct address_space *mapping,
1462 			    struct writeback_control *wbc)
1463 {
1464 	struct inode *inode = mapping->host;
1465 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1466 	struct blk_plug plug;
1467 	int ret;
1468 
1469 	/* deal with chardevs and other special file */
1470 	if (!mapping->a_ops->writepage)
1471 		return 0;
1472 
1473 	/* skip writing if there is no dirty page in this inode */
1474 	if (!get_dirty_pages(inode) && wbc->sync_mode == WB_SYNC_NONE)
1475 		return 0;
1476 
1477 	if (S_ISDIR(inode->i_mode) && wbc->sync_mode == WB_SYNC_NONE &&
1478 			get_dirty_pages(inode) < nr_pages_to_skip(sbi, DATA) &&
1479 			available_free_memory(sbi, DIRTY_DENTS))
1480 		goto skip_write;
1481 
1482 	/* skip writing during file defragment */
1483 	if (is_inode_flag_set(inode, FI_DO_DEFRAG))
1484 		goto skip_write;
1485 
1486 	/* during POR, we don't need to trigger writepage at all. */
1487 	if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
1488 		goto skip_write;
1489 
1490 	trace_f2fs_writepages(mapping->host, wbc, DATA);
1491 
1492 	blk_start_plug(&plug);
1493 	ret = f2fs_write_cache_pages(mapping, wbc);
1494 	blk_finish_plug(&plug);
1495 	/*
1496 	 * if some pages were truncated, we cannot guarantee its mapping->host
1497 	 * to detect pending bios.
1498 	 */
1499 
1500 	remove_dirty_inode(inode);
1501 	return ret;
1502 
1503 skip_write:
1504 	wbc->pages_skipped += get_dirty_pages(inode);
1505 	trace_f2fs_writepages(mapping->host, wbc, DATA);
1506 	return 0;
1507 }
1508 
1509 static void f2fs_write_failed(struct address_space *mapping, loff_t to)
1510 {
1511 	struct inode *inode = mapping->host;
1512 	loff_t i_size = i_size_read(inode);
1513 
1514 	if (to > i_size) {
1515 		truncate_pagecache(inode, i_size);
1516 		truncate_blocks(inode, i_size, true);
1517 	}
1518 }
1519 
1520 static int prepare_write_begin(struct f2fs_sb_info *sbi,
1521 			struct page *page, loff_t pos, unsigned len,
1522 			block_t *blk_addr, bool *node_changed)
1523 {
1524 	struct inode *inode = page->mapping->host;
1525 	pgoff_t index = page->index;
1526 	struct dnode_of_data dn;
1527 	struct page *ipage;
1528 	bool locked = false;
1529 	struct extent_info ei;
1530 	int err = 0;
1531 
1532 	/*
1533 	 * we already allocated all the blocks, so we don't need to get
1534 	 * the block addresses when there is no need to fill the page.
1535 	 */
1536 	if (!f2fs_has_inline_data(inode) && len == PAGE_SIZE)
1537 		return 0;
1538 
1539 	if (f2fs_has_inline_data(inode) ||
1540 			(pos & PAGE_MASK) >= i_size_read(inode)) {
1541 		f2fs_lock_op(sbi);
1542 		locked = true;
1543 	}
1544 restart:
1545 	/* check inline_data */
1546 	ipage = get_node_page(sbi, inode->i_ino);
1547 	if (IS_ERR(ipage)) {
1548 		err = PTR_ERR(ipage);
1549 		goto unlock_out;
1550 	}
1551 
1552 	set_new_dnode(&dn, inode, ipage, ipage, 0);
1553 
1554 	if (f2fs_has_inline_data(inode)) {
1555 		if (pos + len <= MAX_INLINE_DATA) {
1556 			read_inline_data(page, ipage);
1557 			set_inode_flag(inode, FI_DATA_EXIST);
1558 			if (inode->i_nlink)
1559 				set_inline_node(ipage);
1560 		} else {
1561 			err = f2fs_convert_inline_page(&dn, page);
1562 			if (err)
1563 				goto out;
1564 			if (dn.data_blkaddr == NULL_ADDR)
1565 				err = f2fs_get_block(&dn, index);
1566 		}
1567 	} else if (locked) {
1568 		err = f2fs_get_block(&dn, index);
1569 	} else {
1570 		if (f2fs_lookup_extent_cache(inode, index, &ei)) {
1571 			dn.data_blkaddr = ei.blk + index - ei.fofs;
1572 		} else {
1573 			/* hole case */
1574 			err = get_dnode_of_data(&dn, index, LOOKUP_NODE);
1575 			if (err || dn.data_blkaddr == NULL_ADDR) {
1576 				f2fs_put_dnode(&dn);
1577 				f2fs_lock_op(sbi);
1578 				locked = true;
1579 				goto restart;
1580 			}
1581 		}
1582 	}
1583 
1584 	/* convert_inline_page can make node_changed */
1585 	*blk_addr = dn.data_blkaddr;
1586 	*node_changed = dn.node_changed;
1587 out:
1588 	f2fs_put_dnode(&dn);
1589 unlock_out:
1590 	if (locked)
1591 		f2fs_unlock_op(sbi);
1592 	return err;
1593 }
1594 
1595 static int f2fs_write_begin(struct file *file, struct address_space *mapping,
1596 		loff_t pos, unsigned len, unsigned flags,
1597 		struct page **pagep, void **fsdata)
1598 {
1599 	struct inode *inode = mapping->host;
1600 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1601 	struct page *page = NULL;
1602 	pgoff_t index = ((unsigned long long) pos) >> PAGE_SHIFT;
1603 	bool need_balance = false;
1604 	block_t blkaddr = NULL_ADDR;
1605 	int err = 0;
1606 
1607 	trace_f2fs_write_begin(inode, pos, len, flags);
1608 
1609 	/*
1610 	 * We should check this at this moment to avoid deadlock on inode page
1611 	 * and #0 page. The locking rule for inline_data conversion should be:
1612 	 * lock_page(page #0) -> lock_page(inode_page)
1613 	 */
1614 	if (index != 0) {
1615 		err = f2fs_convert_inline_inode(inode);
1616 		if (err)
1617 			goto fail;
1618 	}
1619 repeat:
1620 	page = grab_cache_page_write_begin(mapping, index, flags);
1621 	if (!page) {
1622 		err = -ENOMEM;
1623 		goto fail;
1624 	}
1625 
1626 	*pagep = page;
1627 
1628 	err = prepare_write_begin(sbi, page, pos, len,
1629 					&blkaddr, &need_balance);
1630 	if (err)
1631 		goto fail;
1632 
1633 	if (need_balance && has_not_enough_free_secs(sbi, 0, 0)) {
1634 		unlock_page(page);
1635 		f2fs_balance_fs(sbi, true);
1636 		lock_page(page);
1637 		if (page->mapping != mapping) {
1638 			/* The page got truncated from under us */
1639 			f2fs_put_page(page, 1);
1640 			goto repeat;
1641 		}
1642 	}
1643 
1644 	f2fs_wait_on_page_writeback(page, DATA, false);
1645 
1646 	/* wait for GCed encrypted page writeback */
1647 	if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode))
1648 		f2fs_wait_on_encrypted_page_writeback(sbi, blkaddr);
1649 
1650 	if (len == PAGE_SIZE || PageUptodate(page))
1651 		return 0;
1652 
1653 	if (blkaddr == NEW_ADDR) {
1654 		zero_user_segment(page, 0, PAGE_SIZE);
1655 		SetPageUptodate(page);
1656 	} else {
1657 		struct bio *bio;
1658 
1659 		bio = f2fs_grab_bio(inode, blkaddr, 1);
1660 		if (IS_ERR(bio)) {
1661 			err = PTR_ERR(bio);
1662 			goto fail;
1663 		}
1664 		bio->bi_opf = REQ_OP_READ;
1665 		if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
1666 			bio_put(bio);
1667 			err = -EFAULT;
1668 			goto fail;
1669 		}
1670 
1671 		__submit_bio(sbi, bio, DATA);
1672 
1673 		lock_page(page);
1674 		if (unlikely(page->mapping != mapping)) {
1675 			f2fs_put_page(page, 1);
1676 			goto repeat;
1677 		}
1678 		if (unlikely(!PageUptodate(page))) {
1679 			err = -EIO;
1680 			goto fail;
1681 		}
1682 	}
1683 	return 0;
1684 
1685 fail:
1686 	f2fs_put_page(page, 1);
1687 	f2fs_write_failed(mapping, pos + len);
1688 	return err;
1689 }
1690 
1691 static int f2fs_write_end(struct file *file,
1692 			struct address_space *mapping,
1693 			loff_t pos, unsigned len, unsigned copied,
1694 			struct page *page, void *fsdata)
1695 {
1696 	struct inode *inode = page->mapping->host;
1697 
1698 	trace_f2fs_write_end(inode, pos, len, copied);
1699 
1700 	/*
1701 	 * This should be come from len == PAGE_SIZE, and we expect copied
1702 	 * should be PAGE_SIZE. Otherwise, we treat it with zero copied and
1703 	 * let generic_perform_write() try to copy data again through copied=0.
1704 	 */
1705 	if (!PageUptodate(page)) {
1706 		if (unlikely(copied != PAGE_SIZE))
1707 			copied = 0;
1708 		else
1709 			SetPageUptodate(page);
1710 	}
1711 	if (!copied)
1712 		goto unlock_out;
1713 
1714 	set_page_dirty(page);
1715 	clear_cold_data(page);
1716 
1717 	if (pos + copied > i_size_read(inode))
1718 		f2fs_i_size_write(inode, pos + copied);
1719 unlock_out:
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 rw = iov_iter_rw(iter);
1746 	int err;
1747 
1748 	err = check_direct_IO(inode, iter, offset);
1749 	if (err)
1750 		return err;
1751 
1752 	if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode))
1753 		return 0;
1754 	if (test_opt(F2FS_I_SB(inode), LFS))
1755 		return 0;
1756 
1757 	trace_f2fs_direct_IO_enter(inode, offset, count, rw);
1758 
1759 	down_read(&F2FS_I(inode)->dio_rwsem[rw]);
1760 	err = blockdev_direct_IO(iocb, inode, iter, get_data_block_dio);
1761 	up_read(&F2FS_I(inode)->dio_rwsem[rw]);
1762 
1763 	if (rw == WRITE) {
1764 		if (err > 0)
1765 			set_inode_flag(inode, FI_UPDATE_WRITE);
1766 		else if (err < 0)
1767 			f2fs_write_failed(mapping, offset + count);
1768 	}
1769 
1770 	trace_f2fs_direct_IO_exit(inode, offset, count, rw, err);
1771 
1772 	return err;
1773 }
1774 
1775 void f2fs_invalidate_page(struct page *page, unsigned int offset,
1776 							unsigned int length)
1777 {
1778 	struct inode *inode = page->mapping->host;
1779 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1780 
1781 	if (inode->i_ino >= F2FS_ROOT_INO(sbi) &&
1782 		(offset % PAGE_SIZE || length != PAGE_SIZE))
1783 		return;
1784 
1785 	if (PageDirty(page)) {
1786 		if (inode->i_ino == F2FS_META_INO(sbi))
1787 			dec_page_count(sbi, F2FS_DIRTY_META);
1788 		else if (inode->i_ino == F2FS_NODE_INO(sbi))
1789 			dec_page_count(sbi, F2FS_DIRTY_NODES);
1790 		else
1791 			inode_dec_dirty_pages(inode);
1792 	}
1793 
1794 	/* This is atomic written page, keep Private */
1795 	if (IS_ATOMIC_WRITTEN_PAGE(page))
1796 		return;
1797 
1798 	set_page_private(page, 0);
1799 	ClearPagePrivate(page);
1800 }
1801 
1802 int f2fs_release_page(struct page *page, gfp_t wait)
1803 {
1804 	/* If this is dirty page, keep PagePrivate */
1805 	if (PageDirty(page))
1806 		return 0;
1807 
1808 	/* This is atomic written page, keep Private */
1809 	if (IS_ATOMIC_WRITTEN_PAGE(page))
1810 		return 0;
1811 
1812 	set_page_private(page, 0);
1813 	ClearPagePrivate(page);
1814 	return 1;
1815 }
1816 
1817 /*
1818  * This was copied from __set_page_dirty_buffers which gives higher performance
1819  * in very high speed storages. (e.g., pmem)
1820  */
1821 void f2fs_set_page_dirty_nobuffers(struct page *page)
1822 {
1823 	struct address_space *mapping = page->mapping;
1824 	unsigned long flags;
1825 
1826 	if (unlikely(!mapping))
1827 		return;
1828 
1829 	spin_lock(&mapping->private_lock);
1830 	lock_page_memcg(page);
1831 	SetPageDirty(page);
1832 	spin_unlock(&mapping->private_lock);
1833 
1834 	spin_lock_irqsave(&mapping->tree_lock, flags);
1835 	WARN_ON_ONCE(!PageUptodate(page));
1836 	account_page_dirtied(page, mapping);
1837 	radix_tree_tag_set(&mapping->page_tree,
1838 			page_index(page), PAGECACHE_TAG_DIRTY);
1839 	spin_unlock_irqrestore(&mapping->tree_lock, flags);
1840 	unlock_page_memcg(page);
1841 
1842 	__mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
1843 	return;
1844 }
1845 
1846 static int f2fs_set_data_page_dirty(struct page *page)
1847 {
1848 	struct address_space *mapping = page->mapping;
1849 	struct inode *inode = mapping->host;
1850 
1851 	trace_f2fs_set_page_dirty(page, DATA);
1852 
1853 	if (!PageUptodate(page))
1854 		SetPageUptodate(page);
1855 
1856 	if (f2fs_is_atomic_file(inode)) {
1857 		if (!IS_ATOMIC_WRITTEN_PAGE(page)) {
1858 			register_inmem_page(inode, page);
1859 			return 1;
1860 		}
1861 		/*
1862 		 * Previously, this page has been registered, we just
1863 		 * return here.
1864 		 */
1865 		return 0;
1866 	}
1867 
1868 	if (!PageDirty(page)) {
1869 		f2fs_set_page_dirty_nobuffers(page);
1870 		update_dirty_page(inode, page);
1871 		return 1;
1872 	}
1873 	return 0;
1874 }
1875 
1876 static sector_t f2fs_bmap(struct address_space *mapping, sector_t block)
1877 {
1878 	struct inode *inode = mapping->host;
1879 
1880 	if (f2fs_has_inline_data(inode))
1881 		return 0;
1882 
1883 	/* make sure allocating whole blocks */
1884 	if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
1885 		filemap_write_and_wait(mapping);
1886 
1887 	return generic_block_bmap(mapping, block, get_data_block_bmap);
1888 }
1889 
1890 #ifdef CONFIG_MIGRATION
1891 #include <linux/migrate.h>
1892 
1893 int f2fs_migrate_page(struct address_space *mapping,
1894 		struct page *newpage, struct page *page, enum migrate_mode mode)
1895 {
1896 	int rc, extra_count;
1897 	struct f2fs_inode_info *fi = F2FS_I(mapping->host);
1898 	bool atomic_written = IS_ATOMIC_WRITTEN_PAGE(page);
1899 
1900 	BUG_ON(PageWriteback(page));
1901 
1902 	/* migrating an atomic written page is safe with the inmem_lock hold */
1903 	if (atomic_written && !mutex_trylock(&fi->inmem_lock))
1904 		return -EAGAIN;
1905 
1906 	/*
1907 	 * A reference is expected if PagePrivate set when move mapping,
1908 	 * however F2FS breaks this for maintaining dirty page counts when
1909 	 * truncating pages. So here adjusting the 'extra_count' make it work.
1910 	 */
1911 	extra_count = (atomic_written ? 1 : 0) - page_has_private(page);
1912 	rc = migrate_page_move_mapping(mapping, newpage,
1913 				page, NULL, mode, extra_count);
1914 	if (rc != MIGRATEPAGE_SUCCESS) {
1915 		if (atomic_written)
1916 			mutex_unlock(&fi->inmem_lock);
1917 		return rc;
1918 	}
1919 
1920 	if (atomic_written) {
1921 		struct inmem_pages *cur;
1922 		list_for_each_entry(cur, &fi->inmem_pages, list)
1923 			if (cur->page == page) {
1924 				cur->page = newpage;
1925 				break;
1926 			}
1927 		mutex_unlock(&fi->inmem_lock);
1928 		put_page(page);
1929 		get_page(newpage);
1930 	}
1931 
1932 	if (PagePrivate(page))
1933 		SetPagePrivate(newpage);
1934 	set_page_private(newpage, page_private(page));
1935 
1936 	migrate_page_copy(newpage, page);
1937 
1938 	return MIGRATEPAGE_SUCCESS;
1939 }
1940 #endif
1941 
1942 const struct address_space_operations f2fs_dblock_aops = {
1943 	.readpage	= f2fs_read_data_page,
1944 	.readpages	= f2fs_read_data_pages,
1945 	.writepage	= f2fs_write_data_page,
1946 	.writepages	= f2fs_write_data_pages,
1947 	.write_begin	= f2fs_write_begin,
1948 	.write_end	= f2fs_write_end,
1949 	.set_page_dirty	= f2fs_set_data_page_dirty,
1950 	.invalidatepage	= f2fs_invalidate_page,
1951 	.releasepage	= f2fs_release_page,
1952 	.direct_IO	= f2fs_direct_IO,
1953 	.bmap		= f2fs_bmap,
1954 #ifdef CONFIG_MIGRATION
1955 	.migratepage    = f2fs_migrate_page,
1956 #endif
1957 };
1958