xref: /openbmc/linux/fs/f2fs/data.c (revision 1ad71a27124caf0b68ddd3c92be01aa2b2a72b2a)
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 #include <linux/sched/signal.h>
26 
27 #include "f2fs.h"
28 #include "node.h"
29 #include "segment.h"
30 #include "trace.h"
31 #include <trace/events/f2fs.h>
32 
33 static bool __is_cp_guaranteed(struct page *page)
34 {
35 	struct address_space *mapping = page->mapping;
36 	struct inode *inode;
37 	struct f2fs_sb_info *sbi;
38 
39 	if (!mapping)
40 		return false;
41 
42 	inode = mapping->host;
43 	sbi = F2FS_I_SB(inode);
44 
45 	if (inode->i_ino == F2FS_META_INO(sbi) ||
46 			inode->i_ino ==  F2FS_NODE_INO(sbi) ||
47 			S_ISDIR(inode->i_mode) ||
48 			is_cold_data(page))
49 		return true;
50 	return false;
51 }
52 
53 static void f2fs_read_end_io(struct bio *bio)
54 {
55 	struct bio_vec *bvec;
56 	int i;
57 
58 #ifdef CONFIG_F2FS_FAULT_INJECTION
59 	if (time_to_inject(F2FS_P_SB(bio->bi_io_vec->bv_page), FAULT_IO)) {
60 		f2fs_show_injection_info(FAULT_IO);
61 		bio->bi_status = BLK_STS_IOERR;
62 	}
63 #endif
64 
65 	if (f2fs_bio_encrypted(bio)) {
66 		if (bio->bi_status) {
67 			fscrypt_release_ctx(bio->bi_private);
68 		} else {
69 			fscrypt_decrypt_bio_pages(bio->bi_private, bio);
70 			return;
71 		}
72 	}
73 
74 	bio_for_each_segment_all(bvec, bio, i) {
75 		struct page *page = bvec->bv_page;
76 
77 		if (!bio->bi_status) {
78 			if (!PageUptodate(page))
79 				SetPageUptodate(page);
80 		} else {
81 			ClearPageUptodate(page);
82 			SetPageError(page);
83 		}
84 		unlock_page(page);
85 	}
86 	bio_put(bio);
87 }
88 
89 static void f2fs_write_end_io(struct bio *bio)
90 {
91 	struct f2fs_sb_info *sbi = bio->bi_private;
92 	struct bio_vec *bvec;
93 	int i;
94 
95 	bio_for_each_segment_all(bvec, bio, i) {
96 		struct page *page = bvec->bv_page;
97 		enum count_type type = WB_DATA_TYPE(page);
98 
99 		if (IS_DUMMY_WRITTEN_PAGE(page)) {
100 			set_page_private(page, (unsigned long)NULL);
101 			ClearPagePrivate(page);
102 			unlock_page(page);
103 			mempool_free(page, sbi->write_io_dummy);
104 
105 			if (unlikely(bio->bi_status))
106 				f2fs_stop_checkpoint(sbi, true);
107 			continue;
108 		}
109 
110 		fscrypt_pullback_bio_page(&page, true);
111 
112 		if (unlikely(bio->bi_status)) {
113 			mapping_set_error(page->mapping, -EIO);
114 			if (type == F2FS_WB_CP_DATA)
115 				f2fs_stop_checkpoint(sbi, true);
116 		}
117 
118 		f2fs_bug_on(sbi, page->mapping == NODE_MAPPING(sbi) &&
119 					page->index != nid_of_node(page));
120 
121 		dec_page_count(sbi, type);
122 		clear_cold_data(page);
123 		end_page_writeback(page);
124 	}
125 	if (!get_pages(sbi, F2FS_WB_CP_DATA) &&
126 				wq_has_sleeper(&sbi->cp_wait))
127 		wake_up(&sbi->cp_wait);
128 
129 	bio_put(bio);
130 }
131 
132 /*
133  * Return true, if pre_bio's bdev is same as its target device.
134  */
135 struct block_device *f2fs_target_device(struct f2fs_sb_info *sbi,
136 				block_t blk_addr, struct bio *bio)
137 {
138 	struct block_device *bdev = sbi->sb->s_bdev;
139 	int i;
140 
141 	for (i = 0; i < sbi->s_ndevs; i++) {
142 		if (FDEV(i).start_blk <= blk_addr &&
143 					FDEV(i).end_blk >= blk_addr) {
144 			blk_addr -= FDEV(i).start_blk;
145 			bdev = FDEV(i).bdev;
146 			break;
147 		}
148 	}
149 	if (bio) {
150 		bio_set_dev(bio, bdev);
151 		bio->bi_iter.bi_sector = SECTOR_FROM_BLOCK(blk_addr);
152 	}
153 	return bdev;
154 }
155 
156 int f2fs_target_device_index(struct f2fs_sb_info *sbi, block_t blkaddr)
157 {
158 	int i;
159 
160 	for (i = 0; i < sbi->s_ndevs; i++)
161 		if (FDEV(i).start_blk <= blkaddr && FDEV(i).end_blk >= blkaddr)
162 			return i;
163 	return 0;
164 }
165 
166 static bool __same_bdev(struct f2fs_sb_info *sbi,
167 				block_t blk_addr, struct bio *bio)
168 {
169 	struct block_device *b = f2fs_target_device(sbi, blk_addr, NULL);
170 	return bio->bi_disk == b->bd_disk && bio->bi_partno == b->bd_partno;
171 }
172 
173 /*
174  * Low-level block read/write IO operations.
175  */
176 static struct bio *__bio_alloc(struct f2fs_sb_info *sbi, block_t blk_addr,
177 				struct writeback_control *wbc,
178 				int npages, bool is_read)
179 {
180 	struct bio *bio;
181 
182 	bio = f2fs_bio_alloc(sbi, npages, true);
183 
184 	f2fs_target_device(sbi, blk_addr, bio);
185 	bio->bi_end_io = is_read ? f2fs_read_end_io : f2fs_write_end_io;
186 	bio->bi_private = is_read ? NULL : sbi;
187 	if (wbc)
188 		wbc_init_bio(wbc, bio);
189 
190 	return bio;
191 }
192 
193 static inline void __submit_bio(struct f2fs_sb_info *sbi,
194 				struct bio *bio, enum page_type type)
195 {
196 	if (!is_read_io(bio_op(bio))) {
197 		unsigned int start;
198 
199 		if (f2fs_sb_mounted_blkzoned(sbi->sb) &&
200 			current->plug && (type == DATA || type == NODE))
201 			blk_finish_plug(current->plug);
202 
203 		if (type != DATA && type != NODE)
204 			goto submit_io;
205 
206 		start = bio->bi_iter.bi_size >> F2FS_BLKSIZE_BITS;
207 		start %= F2FS_IO_SIZE(sbi);
208 
209 		if (start == 0)
210 			goto submit_io;
211 
212 		/* fill dummy pages */
213 		for (; start < F2FS_IO_SIZE(sbi); start++) {
214 			struct page *page =
215 				mempool_alloc(sbi->write_io_dummy,
216 					GFP_NOIO | __GFP_ZERO | __GFP_NOFAIL);
217 			f2fs_bug_on(sbi, !page);
218 
219 			SetPagePrivate(page);
220 			set_page_private(page, (unsigned long)DUMMY_WRITTEN_PAGE);
221 			lock_page(page);
222 			if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE)
223 				f2fs_bug_on(sbi, 1);
224 		}
225 		/*
226 		 * In the NODE case, we lose next block address chain. So, we
227 		 * need to do checkpoint in f2fs_sync_file.
228 		 */
229 		if (type == NODE)
230 			set_sbi_flag(sbi, SBI_NEED_CP);
231 	}
232 submit_io:
233 	if (is_read_io(bio_op(bio)))
234 		trace_f2fs_submit_read_bio(sbi->sb, type, bio);
235 	else
236 		trace_f2fs_submit_write_bio(sbi->sb, type, bio);
237 	submit_bio(bio);
238 }
239 
240 static void __submit_merged_bio(struct f2fs_bio_info *io)
241 {
242 	struct f2fs_io_info *fio = &io->fio;
243 
244 	if (!io->bio)
245 		return;
246 
247 	bio_set_op_attrs(io->bio, fio->op, fio->op_flags);
248 
249 	if (is_read_io(fio->op))
250 		trace_f2fs_prepare_read_bio(io->sbi->sb, fio->type, io->bio);
251 	else
252 		trace_f2fs_prepare_write_bio(io->sbi->sb, fio->type, io->bio);
253 
254 	__submit_bio(io->sbi, io->bio, fio->type);
255 	io->bio = NULL;
256 }
257 
258 static bool __has_merged_page(struct f2fs_bio_info *io,
259 				struct inode *inode, nid_t ino, pgoff_t idx)
260 {
261 	struct bio_vec *bvec;
262 	struct page *target;
263 	int i;
264 
265 	if (!io->bio)
266 		return false;
267 
268 	if (!inode && !ino)
269 		return true;
270 
271 	bio_for_each_segment_all(bvec, io->bio, i) {
272 
273 		if (bvec->bv_page->mapping)
274 			target = bvec->bv_page;
275 		else
276 			target = fscrypt_control_page(bvec->bv_page);
277 
278 		if (idx != target->index)
279 			continue;
280 
281 		if (inode && inode == target->mapping->host)
282 			return true;
283 		if (ino && ino == ino_of_node(target))
284 			return true;
285 	}
286 
287 	return false;
288 }
289 
290 static bool has_merged_page(struct f2fs_sb_info *sbi, struct inode *inode,
291 				nid_t ino, pgoff_t idx, enum page_type type)
292 {
293 	enum page_type btype = PAGE_TYPE_OF_BIO(type);
294 	enum temp_type temp;
295 	struct f2fs_bio_info *io;
296 	bool ret = false;
297 
298 	for (temp = HOT; temp < NR_TEMP_TYPE; temp++) {
299 		io = sbi->write_io[btype] + temp;
300 
301 		down_read(&io->io_rwsem);
302 		ret = __has_merged_page(io, inode, ino, idx);
303 		up_read(&io->io_rwsem);
304 
305 		/* TODO: use HOT temp only for meta pages now. */
306 		if (ret || btype == META)
307 			break;
308 	}
309 	return ret;
310 }
311 
312 static void __f2fs_submit_merged_write(struct f2fs_sb_info *sbi,
313 				enum page_type type, enum temp_type temp)
314 {
315 	enum page_type btype = PAGE_TYPE_OF_BIO(type);
316 	struct f2fs_bio_info *io = sbi->write_io[btype] + temp;
317 
318 	down_write(&io->io_rwsem);
319 
320 	/* change META to META_FLUSH in the checkpoint procedure */
321 	if (type >= META_FLUSH) {
322 		io->fio.type = META_FLUSH;
323 		io->fio.op = REQ_OP_WRITE;
324 		io->fio.op_flags = REQ_META | REQ_PRIO | REQ_SYNC;
325 		if (!test_opt(sbi, NOBARRIER))
326 			io->fio.op_flags |= REQ_PREFLUSH | REQ_FUA;
327 	}
328 	__submit_merged_bio(io);
329 	up_write(&io->io_rwsem);
330 }
331 
332 static void __submit_merged_write_cond(struct f2fs_sb_info *sbi,
333 				struct inode *inode, nid_t ino, pgoff_t idx,
334 				enum page_type type, bool force)
335 {
336 	enum temp_type temp;
337 
338 	if (!force && !has_merged_page(sbi, inode, ino, idx, type))
339 		return;
340 
341 	for (temp = HOT; temp < NR_TEMP_TYPE; temp++) {
342 
343 		__f2fs_submit_merged_write(sbi, type, temp);
344 
345 		/* TODO: use HOT temp only for meta pages now. */
346 		if (type >= META)
347 			break;
348 	}
349 }
350 
351 void f2fs_submit_merged_write(struct f2fs_sb_info *sbi, enum page_type type)
352 {
353 	__submit_merged_write_cond(sbi, NULL, 0, 0, type, true);
354 }
355 
356 void f2fs_submit_merged_write_cond(struct f2fs_sb_info *sbi,
357 				struct inode *inode, nid_t ino, pgoff_t idx,
358 				enum page_type type)
359 {
360 	__submit_merged_write_cond(sbi, inode, ino, idx, type, false);
361 }
362 
363 void f2fs_flush_merged_writes(struct f2fs_sb_info *sbi)
364 {
365 	f2fs_submit_merged_write(sbi, DATA);
366 	f2fs_submit_merged_write(sbi, NODE);
367 	f2fs_submit_merged_write(sbi, META);
368 }
369 
370 /*
371  * Fill the locked page with data located in the block address.
372  * A caller needs to unlock the page on failure.
373  */
374 int f2fs_submit_page_bio(struct f2fs_io_info *fio)
375 {
376 	struct bio *bio;
377 	struct page *page = fio->encrypted_page ?
378 			fio->encrypted_page : fio->page;
379 
380 	trace_f2fs_submit_page_bio(page, fio);
381 	f2fs_trace_ios(fio, 0);
382 
383 	/* Allocate a new bio */
384 	bio = __bio_alloc(fio->sbi, fio->new_blkaddr, fio->io_wbc,
385 				1, is_read_io(fio->op));
386 
387 	if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
388 		bio_put(bio);
389 		return -EFAULT;
390 	}
391 	bio_set_op_attrs(bio, fio->op, fio->op_flags);
392 
393 	__submit_bio(fio->sbi, bio, fio->type);
394 
395 	if (!is_read_io(fio->op))
396 		inc_page_count(fio->sbi, WB_DATA_TYPE(fio->page));
397 	return 0;
398 }
399 
400 int f2fs_submit_page_write(struct f2fs_io_info *fio)
401 {
402 	struct f2fs_sb_info *sbi = fio->sbi;
403 	enum page_type btype = PAGE_TYPE_OF_BIO(fio->type);
404 	struct f2fs_bio_info *io = sbi->write_io[btype] + fio->temp;
405 	struct page *bio_page;
406 	int err = 0;
407 
408 	f2fs_bug_on(sbi, is_read_io(fio->op));
409 
410 	down_write(&io->io_rwsem);
411 next:
412 	if (fio->in_list) {
413 		spin_lock(&io->io_lock);
414 		if (list_empty(&io->io_list)) {
415 			spin_unlock(&io->io_lock);
416 			goto out_fail;
417 		}
418 		fio = list_first_entry(&io->io_list,
419 						struct f2fs_io_info, list);
420 		list_del(&fio->list);
421 		spin_unlock(&io->io_lock);
422 	}
423 
424 	if (fio->old_blkaddr != NEW_ADDR)
425 		verify_block_addr(sbi, fio->old_blkaddr);
426 	verify_block_addr(sbi, fio->new_blkaddr);
427 
428 	bio_page = fio->encrypted_page ? fio->encrypted_page : fio->page;
429 
430 	/* set submitted = true as a return value */
431 	fio->submitted = true;
432 
433 	inc_page_count(sbi, WB_DATA_TYPE(bio_page));
434 
435 	if (io->bio && (io->last_block_in_bio != fio->new_blkaddr - 1 ||
436 	    (io->fio.op != fio->op || io->fio.op_flags != fio->op_flags) ||
437 			!__same_bdev(sbi, fio->new_blkaddr, io->bio)))
438 		__submit_merged_bio(io);
439 alloc_new:
440 	if (io->bio == NULL) {
441 		if ((fio->type == DATA || fio->type == NODE) &&
442 				fio->new_blkaddr & F2FS_IO_SIZE_MASK(sbi)) {
443 			err = -EAGAIN;
444 			dec_page_count(sbi, WB_DATA_TYPE(bio_page));
445 			goto out_fail;
446 		}
447 		io->bio = __bio_alloc(sbi, fio->new_blkaddr, fio->io_wbc,
448 						BIO_MAX_PAGES, false);
449 		io->fio = *fio;
450 	}
451 
452 	if (bio_add_page(io->bio, bio_page, PAGE_SIZE, 0) < PAGE_SIZE) {
453 		__submit_merged_bio(io);
454 		goto alloc_new;
455 	}
456 
457 	if (fio->io_wbc)
458 		wbc_account_io(fio->io_wbc, bio_page, PAGE_SIZE);
459 
460 	io->last_block_in_bio = fio->new_blkaddr;
461 	f2fs_trace_ios(fio, 0);
462 
463 	trace_f2fs_submit_page_write(fio->page, fio);
464 
465 	if (fio->in_list)
466 		goto next;
467 out_fail:
468 	up_write(&io->io_rwsem);
469 	return err;
470 }
471 
472 static struct bio *f2fs_grab_read_bio(struct inode *inode, block_t blkaddr,
473 							 unsigned nr_pages)
474 {
475 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
476 	struct fscrypt_ctx *ctx = NULL;
477 	struct bio *bio;
478 
479 	if (f2fs_encrypted_file(inode)) {
480 		ctx = fscrypt_get_ctx(inode, GFP_NOFS);
481 		if (IS_ERR(ctx))
482 			return ERR_CAST(ctx);
483 
484 		/* wait the page to be moved by cleaning */
485 		f2fs_wait_on_block_writeback(sbi, blkaddr);
486 	}
487 
488 	bio = f2fs_bio_alloc(sbi, min_t(int, nr_pages, BIO_MAX_PAGES), false);
489 	if (!bio) {
490 		if (ctx)
491 			fscrypt_release_ctx(ctx);
492 		return ERR_PTR(-ENOMEM);
493 	}
494 	f2fs_target_device(sbi, blkaddr, bio);
495 	bio->bi_end_io = f2fs_read_end_io;
496 	bio->bi_private = ctx;
497 	bio_set_op_attrs(bio, REQ_OP_READ, 0);
498 
499 	return bio;
500 }
501 
502 /* This can handle encryption stuffs */
503 static int f2fs_submit_page_read(struct inode *inode, struct page *page,
504 							block_t blkaddr)
505 {
506 	struct bio *bio = f2fs_grab_read_bio(inode, blkaddr, 1);
507 
508 	if (IS_ERR(bio))
509 		return PTR_ERR(bio);
510 
511 	if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
512 		bio_put(bio);
513 		return -EFAULT;
514 	}
515 	__submit_bio(F2FS_I_SB(inode), bio, DATA);
516 	return 0;
517 }
518 
519 static void __set_data_blkaddr(struct dnode_of_data *dn)
520 {
521 	struct f2fs_node *rn = F2FS_NODE(dn->node_page);
522 	__le32 *addr_array;
523 	int base = 0;
524 
525 	if (IS_INODE(dn->node_page) && f2fs_has_extra_attr(dn->inode))
526 		base = get_extra_isize(dn->inode);
527 
528 	/* Get physical address of data block */
529 	addr_array = blkaddr_in_node(rn);
530 	addr_array[base + dn->ofs_in_node] = cpu_to_le32(dn->data_blkaddr);
531 }
532 
533 /*
534  * Lock ordering for the change of data block address:
535  * ->data_page
536  *  ->node_page
537  *    update block addresses in the node page
538  */
539 void set_data_blkaddr(struct dnode_of_data *dn)
540 {
541 	f2fs_wait_on_page_writeback(dn->node_page, NODE, true);
542 	__set_data_blkaddr(dn);
543 	if (set_page_dirty(dn->node_page))
544 		dn->node_changed = true;
545 }
546 
547 void f2fs_update_data_blkaddr(struct dnode_of_data *dn, block_t blkaddr)
548 {
549 	dn->data_blkaddr = blkaddr;
550 	set_data_blkaddr(dn);
551 	f2fs_update_extent_cache(dn);
552 }
553 
554 /* dn->ofs_in_node will be returned with up-to-date last block pointer */
555 int reserve_new_blocks(struct dnode_of_data *dn, blkcnt_t count)
556 {
557 	struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
558 	int err;
559 
560 	if (!count)
561 		return 0;
562 
563 	if (unlikely(is_inode_flag_set(dn->inode, FI_NO_ALLOC)))
564 		return -EPERM;
565 	if (unlikely((err = inc_valid_block_count(sbi, dn->inode, &count))))
566 		return err;
567 
568 	trace_f2fs_reserve_new_blocks(dn->inode, dn->nid,
569 						dn->ofs_in_node, count);
570 
571 	f2fs_wait_on_page_writeback(dn->node_page, NODE, true);
572 
573 	for (; count > 0; dn->ofs_in_node++) {
574 		block_t blkaddr = datablock_addr(dn->inode,
575 					dn->node_page, dn->ofs_in_node);
576 		if (blkaddr == NULL_ADDR) {
577 			dn->data_blkaddr = NEW_ADDR;
578 			__set_data_blkaddr(dn);
579 			count--;
580 		}
581 	}
582 
583 	if (set_page_dirty(dn->node_page))
584 		dn->node_changed = true;
585 	return 0;
586 }
587 
588 /* Should keep dn->ofs_in_node unchanged */
589 int reserve_new_block(struct dnode_of_data *dn)
590 {
591 	unsigned int ofs_in_node = dn->ofs_in_node;
592 	int ret;
593 
594 	ret = reserve_new_blocks(dn, 1);
595 	dn->ofs_in_node = ofs_in_node;
596 	return ret;
597 }
598 
599 int f2fs_reserve_block(struct dnode_of_data *dn, pgoff_t index)
600 {
601 	bool need_put = dn->inode_page ? false : true;
602 	int err;
603 
604 	err = get_dnode_of_data(dn, index, ALLOC_NODE);
605 	if (err)
606 		return err;
607 
608 	if (dn->data_blkaddr == NULL_ADDR)
609 		err = reserve_new_block(dn);
610 	if (err || need_put)
611 		f2fs_put_dnode(dn);
612 	return err;
613 }
614 
615 int f2fs_get_block(struct dnode_of_data *dn, pgoff_t index)
616 {
617 	struct extent_info ei  = {0,0,0};
618 	struct inode *inode = dn->inode;
619 
620 	if (f2fs_lookup_extent_cache(inode, index, &ei)) {
621 		dn->data_blkaddr = ei.blk + index - ei.fofs;
622 		return 0;
623 	}
624 
625 	return f2fs_reserve_block(dn, index);
626 }
627 
628 struct page *get_read_data_page(struct inode *inode, pgoff_t index,
629 						int op_flags, bool for_write)
630 {
631 	struct address_space *mapping = inode->i_mapping;
632 	struct dnode_of_data dn;
633 	struct page *page;
634 	struct extent_info ei = {0,0,0};
635 	int err;
636 
637 	page = f2fs_grab_cache_page(mapping, index, for_write);
638 	if (!page)
639 		return ERR_PTR(-ENOMEM);
640 
641 	if (f2fs_lookup_extent_cache(inode, index, &ei)) {
642 		dn.data_blkaddr = ei.blk + index - ei.fofs;
643 		goto got_it;
644 	}
645 
646 	set_new_dnode(&dn, inode, NULL, NULL, 0);
647 	err = get_dnode_of_data(&dn, index, LOOKUP_NODE);
648 	if (err)
649 		goto put_err;
650 	f2fs_put_dnode(&dn);
651 
652 	if (unlikely(dn.data_blkaddr == NULL_ADDR)) {
653 		err = -ENOENT;
654 		goto put_err;
655 	}
656 got_it:
657 	if (PageUptodate(page)) {
658 		unlock_page(page);
659 		return page;
660 	}
661 
662 	/*
663 	 * A new dentry page is allocated but not able to be written, since its
664 	 * new inode page couldn't be allocated due to -ENOSPC.
665 	 * In such the case, its blkaddr can be remained as NEW_ADDR.
666 	 * see, f2fs_add_link -> get_new_data_page -> init_inode_metadata.
667 	 */
668 	if (dn.data_blkaddr == NEW_ADDR) {
669 		zero_user_segment(page, 0, PAGE_SIZE);
670 		if (!PageUptodate(page))
671 			SetPageUptodate(page);
672 		unlock_page(page);
673 		return page;
674 	}
675 
676 	err = f2fs_submit_page_read(inode, page, dn.data_blkaddr);
677 	if (err)
678 		goto put_err;
679 	return page;
680 
681 put_err:
682 	f2fs_put_page(page, 1);
683 	return ERR_PTR(err);
684 }
685 
686 struct page *find_data_page(struct inode *inode, pgoff_t index)
687 {
688 	struct address_space *mapping = inode->i_mapping;
689 	struct page *page;
690 
691 	page = find_get_page(mapping, index);
692 	if (page && PageUptodate(page))
693 		return page;
694 	f2fs_put_page(page, 0);
695 
696 	page = get_read_data_page(inode, index, 0, false);
697 	if (IS_ERR(page))
698 		return page;
699 
700 	if (PageUptodate(page))
701 		return page;
702 
703 	wait_on_page_locked(page);
704 	if (unlikely(!PageUptodate(page))) {
705 		f2fs_put_page(page, 0);
706 		return ERR_PTR(-EIO);
707 	}
708 	return page;
709 }
710 
711 /*
712  * If it tries to access a hole, return an error.
713  * Because, the callers, functions in dir.c and GC, should be able to know
714  * whether this page exists or not.
715  */
716 struct page *get_lock_data_page(struct inode *inode, pgoff_t index,
717 							bool for_write)
718 {
719 	struct address_space *mapping = inode->i_mapping;
720 	struct page *page;
721 repeat:
722 	page = get_read_data_page(inode, index, 0, for_write);
723 	if (IS_ERR(page))
724 		return page;
725 
726 	/* wait for read completion */
727 	lock_page(page);
728 	if (unlikely(page->mapping != mapping)) {
729 		f2fs_put_page(page, 1);
730 		goto repeat;
731 	}
732 	if (unlikely(!PageUptodate(page))) {
733 		f2fs_put_page(page, 1);
734 		return ERR_PTR(-EIO);
735 	}
736 	return page;
737 }
738 
739 /*
740  * Caller ensures that this data page is never allocated.
741  * A new zero-filled data page is allocated in the page cache.
742  *
743  * Also, caller should grab and release a rwsem by calling f2fs_lock_op() and
744  * f2fs_unlock_op().
745  * Note that, ipage is set only by make_empty_dir, and if any error occur,
746  * ipage should be released by this function.
747  */
748 struct page *get_new_data_page(struct inode *inode,
749 		struct page *ipage, pgoff_t index, bool new_i_size)
750 {
751 	struct address_space *mapping = inode->i_mapping;
752 	struct page *page;
753 	struct dnode_of_data dn;
754 	int err;
755 
756 	page = f2fs_grab_cache_page(mapping, index, true);
757 	if (!page) {
758 		/*
759 		 * before exiting, we should make sure ipage will be released
760 		 * if any error occur.
761 		 */
762 		f2fs_put_page(ipage, 1);
763 		return ERR_PTR(-ENOMEM);
764 	}
765 
766 	set_new_dnode(&dn, inode, ipage, NULL, 0);
767 	err = f2fs_reserve_block(&dn, index);
768 	if (err) {
769 		f2fs_put_page(page, 1);
770 		return ERR_PTR(err);
771 	}
772 	if (!ipage)
773 		f2fs_put_dnode(&dn);
774 
775 	if (PageUptodate(page))
776 		goto got_it;
777 
778 	if (dn.data_blkaddr == NEW_ADDR) {
779 		zero_user_segment(page, 0, PAGE_SIZE);
780 		if (!PageUptodate(page))
781 			SetPageUptodate(page);
782 	} else {
783 		f2fs_put_page(page, 1);
784 
785 		/* if ipage exists, blkaddr should be NEW_ADDR */
786 		f2fs_bug_on(F2FS_I_SB(inode), ipage);
787 		page = get_lock_data_page(inode, index, true);
788 		if (IS_ERR(page))
789 			return page;
790 	}
791 got_it:
792 	if (new_i_size && i_size_read(inode) <
793 				((loff_t)(index + 1) << PAGE_SHIFT))
794 		f2fs_i_size_write(inode, ((loff_t)(index + 1) << PAGE_SHIFT));
795 	return page;
796 }
797 
798 static int __allocate_data_block(struct dnode_of_data *dn, int seg_type)
799 {
800 	struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
801 	struct f2fs_summary sum;
802 	struct node_info ni;
803 	pgoff_t fofs;
804 	blkcnt_t count = 1;
805 	int err;
806 
807 	if (unlikely(is_inode_flag_set(dn->inode, FI_NO_ALLOC)))
808 		return -EPERM;
809 
810 	dn->data_blkaddr = datablock_addr(dn->inode,
811 				dn->node_page, dn->ofs_in_node);
812 	if (dn->data_blkaddr == NEW_ADDR)
813 		goto alloc;
814 
815 	if (unlikely((err = inc_valid_block_count(sbi, dn->inode, &count))))
816 		return err;
817 
818 alloc:
819 	get_node_info(sbi, dn->nid, &ni);
820 	set_summary(&sum, dn->nid, dn->ofs_in_node, ni.version);
821 
822 	allocate_data_block(sbi, NULL, dn->data_blkaddr, &dn->data_blkaddr,
823 					&sum, seg_type, NULL, false);
824 	set_data_blkaddr(dn);
825 
826 	/* update i_size */
827 	fofs = start_bidx_of_node(ofs_of_node(dn->node_page), dn->inode) +
828 							dn->ofs_in_node;
829 	if (i_size_read(dn->inode) < ((loff_t)(fofs + 1) << PAGE_SHIFT))
830 		f2fs_i_size_write(dn->inode,
831 				((loff_t)(fofs + 1) << PAGE_SHIFT));
832 	return 0;
833 }
834 
835 static inline bool __force_buffered_io(struct inode *inode, int rw)
836 {
837 	return (f2fs_encrypted_file(inode) ||
838 			(rw == WRITE && test_opt(F2FS_I_SB(inode), LFS)) ||
839 			F2FS_I_SB(inode)->s_ndevs);
840 }
841 
842 int f2fs_preallocate_blocks(struct kiocb *iocb, struct iov_iter *from)
843 {
844 	struct inode *inode = file_inode(iocb->ki_filp);
845 	struct f2fs_map_blocks map;
846 	int flag;
847 	int err = 0;
848 	bool direct_io = iocb->ki_flags & IOCB_DIRECT;
849 
850 	/* convert inline data for Direct I/O*/
851 	if (direct_io) {
852 		err = f2fs_convert_inline_inode(inode);
853 		if (err)
854 			return err;
855 	}
856 
857 	if (is_inode_flag_set(inode, FI_NO_PREALLOC))
858 		return 0;
859 
860 	map.m_lblk = F2FS_BLK_ALIGN(iocb->ki_pos);
861 	map.m_len = F2FS_BYTES_TO_BLK(iocb->ki_pos + iov_iter_count(from));
862 	if (map.m_len > map.m_lblk)
863 		map.m_len -= map.m_lblk;
864 	else
865 		map.m_len = 0;
866 
867 	map.m_next_pgofs = NULL;
868 	map.m_seg_type = NO_CHECK_TYPE;
869 
870 	if (direct_io) {
871 		map.m_seg_type = rw_hint_to_seg_type(iocb->ki_hint);
872 		flag = __force_buffered_io(inode, WRITE) ?
873 					F2FS_GET_BLOCK_PRE_AIO :
874 					F2FS_GET_BLOCK_PRE_DIO;
875 		goto map_blocks;
876 	}
877 	if (iocb->ki_pos + iov_iter_count(from) > MAX_INLINE_DATA(inode)) {
878 		err = f2fs_convert_inline_inode(inode);
879 		if (err)
880 			return err;
881 	}
882 	if (f2fs_has_inline_data(inode))
883 		return err;
884 
885 	flag = F2FS_GET_BLOCK_PRE_AIO;
886 
887 map_blocks:
888 	err = f2fs_map_blocks(inode, &map, 1, flag);
889 	if (map.m_len > 0 && err == -ENOSPC) {
890 		if (!direct_io)
891 			set_inode_flag(inode, FI_NO_PREALLOC);
892 		err = 0;
893 	}
894 	return err;
895 }
896 
897 static inline void __do_map_lock(struct f2fs_sb_info *sbi, int flag, bool lock)
898 {
899 	if (flag == F2FS_GET_BLOCK_PRE_AIO) {
900 		if (lock)
901 			down_read(&sbi->node_change);
902 		else
903 			up_read(&sbi->node_change);
904 	} else {
905 		if (lock)
906 			f2fs_lock_op(sbi);
907 		else
908 			f2fs_unlock_op(sbi);
909 	}
910 }
911 
912 /*
913  * f2fs_map_blocks() now supported readahead/bmap/rw direct_IO with
914  * f2fs_map_blocks structure.
915  * If original data blocks are allocated, then give them to blockdev.
916  * Otherwise,
917  *     a. preallocate requested block addresses
918  *     b. do not use extent cache for better performance
919  *     c. give the block addresses to blockdev
920  */
921 int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map,
922 						int create, int flag)
923 {
924 	unsigned int maxblocks = map->m_len;
925 	struct dnode_of_data dn;
926 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
927 	int mode = create ? ALLOC_NODE : LOOKUP_NODE;
928 	pgoff_t pgofs, end_offset, end;
929 	int err = 0, ofs = 1;
930 	unsigned int ofs_in_node, last_ofs_in_node;
931 	blkcnt_t prealloc;
932 	struct extent_info ei = {0,0,0};
933 	block_t blkaddr;
934 
935 	if (!maxblocks)
936 		return 0;
937 
938 	map->m_len = 0;
939 	map->m_flags = 0;
940 
941 	/* it only supports block size == page size */
942 	pgofs =	(pgoff_t)map->m_lblk;
943 	end = pgofs + maxblocks;
944 
945 	if (!create && f2fs_lookup_extent_cache(inode, pgofs, &ei)) {
946 		map->m_pblk = ei.blk + pgofs - ei.fofs;
947 		map->m_len = min((pgoff_t)maxblocks, ei.fofs + ei.len - pgofs);
948 		map->m_flags = F2FS_MAP_MAPPED;
949 		goto out;
950 	}
951 
952 next_dnode:
953 	if (create)
954 		__do_map_lock(sbi, flag, true);
955 
956 	/* When reading holes, we need its node page */
957 	set_new_dnode(&dn, inode, NULL, NULL, 0);
958 	err = get_dnode_of_data(&dn, pgofs, mode);
959 	if (err) {
960 		if (flag == F2FS_GET_BLOCK_BMAP)
961 			map->m_pblk = 0;
962 		if (err == -ENOENT) {
963 			err = 0;
964 			if (map->m_next_pgofs)
965 				*map->m_next_pgofs =
966 					get_next_page_offset(&dn, pgofs);
967 		}
968 		goto unlock_out;
969 	}
970 
971 	prealloc = 0;
972 	last_ofs_in_node = ofs_in_node = dn.ofs_in_node;
973 	end_offset = ADDRS_PER_PAGE(dn.node_page, inode);
974 
975 next_block:
976 	blkaddr = datablock_addr(dn.inode, dn.node_page, dn.ofs_in_node);
977 
978 	if (blkaddr == NEW_ADDR || blkaddr == NULL_ADDR) {
979 		if (create) {
980 			if (unlikely(f2fs_cp_error(sbi))) {
981 				err = -EIO;
982 				goto sync_out;
983 			}
984 			if (flag == F2FS_GET_BLOCK_PRE_AIO) {
985 				if (blkaddr == NULL_ADDR) {
986 					prealloc++;
987 					last_ofs_in_node = dn.ofs_in_node;
988 				}
989 			} else {
990 				err = __allocate_data_block(&dn,
991 							map->m_seg_type);
992 				if (!err)
993 					set_inode_flag(inode, FI_APPEND_WRITE);
994 			}
995 			if (err)
996 				goto sync_out;
997 			map->m_flags |= F2FS_MAP_NEW;
998 			blkaddr = dn.data_blkaddr;
999 		} else {
1000 			if (flag == F2FS_GET_BLOCK_BMAP) {
1001 				map->m_pblk = 0;
1002 				goto sync_out;
1003 			}
1004 			if (flag == F2FS_GET_BLOCK_FIEMAP &&
1005 						blkaddr == NULL_ADDR) {
1006 				if (map->m_next_pgofs)
1007 					*map->m_next_pgofs = pgofs + 1;
1008 				goto sync_out;
1009 			}
1010 			if (flag != F2FS_GET_BLOCK_FIEMAP)
1011 				goto sync_out;
1012 		}
1013 	}
1014 
1015 	if (flag == F2FS_GET_BLOCK_PRE_AIO)
1016 		goto skip;
1017 
1018 	if (map->m_len == 0) {
1019 		/* preallocated unwritten block should be mapped for fiemap. */
1020 		if (blkaddr == NEW_ADDR)
1021 			map->m_flags |= F2FS_MAP_UNWRITTEN;
1022 		map->m_flags |= F2FS_MAP_MAPPED;
1023 
1024 		map->m_pblk = blkaddr;
1025 		map->m_len = 1;
1026 	} else if ((map->m_pblk != NEW_ADDR &&
1027 			blkaddr == (map->m_pblk + ofs)) ||
1028 			(map->m_pblk == NEW_ADDR && blkaddr == NEW_ADDR) ||
1029 			flag == F2FS_GET_BLOCK_PRE_DIO) {
1030 		ofs++;
1031 		map->m_len++;
1032 	} else {
1033 		goto sync_out;
1034 	}
1035 
1036 skip:
1037 	dn.ofs_in_node++;
1038 	pgofs++;
1039 
1040 	/* preallocate blocks in batch for one dnode page */
1041 	if (flag == F2FS_GET_BLOCK_PRE_AIO &&
1042 			(pgofs == end || dn.ofs_in_node == end_offset)) {
1043 
1044 		dn.ofs_in_node = ofs_in_node;
1045 		err = reserve_new_blocks(&dn, prealloc);
1046 		if (err)
1047 			goto sync_out;
1048 
1049 		map->m_len += dn.ofs_in_node - ofs_in_node;
1050 		if (prealloc && dn.ofs_in_node != last_ofs_in_node + 1) {
1051 			err = -ENOSPC;
1052 			goto sync_out;
1053 		}
1054 		dn.ofs_in_node = end_offset;
1055 	}
1056 
1057 	if (pgofs >= end)
1058 		goto sync_out;
1059 	else if (dn.ofs_in_node < end_offset)
1060 		goto next_block;
1061 
1062 	f2fs_put_dnode(&dn);
1063 
1064 	if (create) {
1065 		__do_map_lock(sbi, flag, false);
1066 		f2fs_balance_fs(sbi, dn.node_changed);
1067 	}
1068 	goto next_dnode;
1069 
1070 sync_out:
1071 	f2fs_put_dnode(&dn);
1072 unlock_out:
1073 	if (create) {
1074 		__do_map_lock(sbi, flag, false);
1075 		f2fs_balance_fs(sbi, dn.node_changed);
1076 	}
1077 out:
1078 	trace_f2fs_map_blocks(inode, map, err);
1079 	return err;
1080 }
1081 
1082 static int __get_data_block(struct inode *inode, sector_t iblock,
1083 			struct buffer_head *bh, int create, int flag,
1084 			pgoff_t *next_pgofs, int seg_type)
1085 {
1086 	struct f2fs_map_blocks map;
1087 	int err;
1088 
1089 	map.m_lblk = iblock;
1090 	map.m_len = bh->b_size >> inode->i_blkbits;
1091 	map.m_next_pgofs = next_pgofs;
1092 	map.m_seg_type = seg_type;
1093 
1094 	err = f2fs_map_blocks(inode, &map, create, flag);
1095 	if (!err) {
1096 		map_bh(bh, inode->i_sb, map.m_pblk);
1097 		bh->b_state = (bh->b_state & ~F2FS_MAP_FLAGS) | map.m_flags;
1098 		bh->b_size = (u64)map.m_len << inode->i_blkbits;
1099 	}
1100 	return err;
1101 }
1102 
1103 static int get_data_block(struct inode *inode, sector_t iblock,
1104 			struct buffer_head *bh_result, int create, int flag,
1105 			pgoff_t *next_pgofs)
1106 {
1107 	return __get_data_block(inode, iblock, bh_result, create,
1108 							flag, next_pgofs,
1109 							NO_CHECK_TYPE);
1110 }
1111 
1112 static int get_data_block_dio(struct inode *inode, sector_t iblock,
1113 			struct buffer_head *bh_result, int create)
1114 {
1115 	return __get_data_block(inode, iblock, bh_result, create,
1116 						F2FS_GET_BLOCK_DEFAULT, NULL,
1117 						rw_hint_to_seg_type(
1118 							inode->i_write_hint));
1119 }
1120 
1121 static int get_data_block_bmap(struct inode *inode, sector_t iblock,
1122 			struct buffer_head *bh_result, int create)
1123 {
1124 	/* Block number less than F2FS MAX BLOCKS */
1125 	if (unlikely(iblock >= F2FS_I_SB(inode)->max_file_blocks))
1126 		return -EFBIG;
1127 
1128 	return __get_data_block(inode, iblock, bh_result, create,
1129 						F2FS_GET_BLOCK_BMAP, NULL,
1130 						NO_CHECK_TYPE);
1131 }
1132 
1133 static inline sector_t logical_to_blk(struct inode *inode, loff_t offset)
1134 {
1135 	return (offset >> inode->i_blkbits);
1136 }
1137 
1138 static inline loff_t blk_to_logical(struct inode *inode, sector_t blk)
1139 {
1140 	return (blk << inode->i_blkbits);
1141 }
1142 
1143 static int f2fs_xattr_fiemap(struct inode *inode,
1144 				struct fiemap_extent_info *fieinfo)
1145 {
1146 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1147 	struct page *page;
1148 	struct node_info ni;
1149 	__u64 phys = 0, len;
1150 	__u32 flags;
1151 	nid_t xnid = F2FS_I(inode)->i_xattr_nid;
1152 	int err = 0;
1153 
1154 	if (f2fs_has_inline_xattr(inode)) {
1155 		int offset;
1156 
1157 		page = f2fs_grab_cache_page(NODE_MAPPING(sbi),
1158 						inode->i_ino, false);
1159 		if (!page)
1160 			return -ENOMEM;
1161 
1162 		get_node_info(sbi, inode->i_ino, &ni);
1163 
1164 		phys = (__u64)blk_to_logical(inode, ni.blk_addr);
1165 		offset = offsetof(struct f2fs_inode, i_addr) +
1166 					sizeof(__le32) * (DEF_ADDRS_PER_INODE -
1167 					F2FS_INLINE_XATTR_ADDRS(inode));
1168 
1169 		phys += offset;
1170 		len = inline_xattr_size(inode);
1171 
1172 		f2fs_put_page(page, 1);
1173 
1174 		flags = FIEMAP_EXTENT_DATA_INLINE | FIEMAP_EXTENT_NOT_ALIGNED;
1175 
1176 		if (!xnid)
1177 			flags |= FIEMAP_EXTENT_LAST;
1178 
1179 		err = fiemap_fill_next_extent(fieinfo, 0, phys, len, flags);
1180 		if (err || err == 1)
1181 			return err;
1182 	}
1183 
1184 	if (xnid) {
1185 		page = f2fs_grab_cache_page(NODE_MAPPING(sbi), xnid, false);
1186 		if (!page)
1187 			return -ENOMEM;
1188 
1189 		get_node_info(sbi, xnid, &ni);
1190 
1191 		phys = (__u64)blk_to_logical(inode, ni.blk_addr);
1192 		len = inode->i_sb->s_blocksize;
1193 
1194 		f2fs_put_page(page, 1);
1195 
1196 		flags = FIEMAP_EXTENT_LAST;
1197 	}
1198 
1199 	if (phys)
1200 		err = fiemap_fill_next_extent(fieinfo, 0, phys, len, flags);
1201 
1202 	return (err < 0 ? err : 0);
1203 }
1204 
1205 int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
1206 		u64 start, u64 len)
1207 {
1208 	struct buffer_head map_bh;
1209 	sector_t start_blk, last_blk;
1210 	pgoff_t next_pgofs;
1211 	u64 logical = 0, phys = 0, size = 0;
1212 	u32 flags = 0;
1213 	int ret = 0;
1214 
1215 	ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC | FIEMAP_FLAG_XATTR);
1216 	if (ret)
1217 		return ret;
1218 
1219 	inode_lock(inode);
1220 
1221 	if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) {
1222 		ret = f2fs_xattr_fiemap(inode, fieinfo);
1223 		goto out;
1224 	}
1225 
1226 	if (f2fs_has_inline_data(inode)) {
1227 		ret = f2fs_inline_data_fiemap(inode, fieinfo, start, len);
1228 		if (ret != -EAGAIN)
1229 			goto out;
1230 	}
1231 
1232 	if (logical_to_blk(inode, len) == 0)
1233 		len = blk_to_logical(inode, 1);
1234 
1235 	start_blk = logical_to_blk(inode, start);
1236 	last_blk = logical_to_blk(inode, start + len - 1);
1237 
1238 next:
1239 	memset(&map_bh, 0, sizeof(struct buffer_head));
1240 	map_bh.b_size = len;
1241 
1242 	ret = get_data_block(inode, start_blk, &map_bh, 0,
1243 					F2FS_GET_BLOCK_FIEMAP, &next_pgofs);
1244 	if (ret)
1245 		goto out;
1246 
1247 	/* HOLE */
1248 	if (!buffer_mapped(&map_bh)) {
1249 		start_blk = next_pgofs;
1250 
1251 		if (blk_to_logical(inode, start_blk) < blk_to_logical(inode,
1252 					F2FS_I_SB(inode)->max_file_blocks))
1253 			goto prep_next;
1254 
1255 		flags |= FIEMAP_EXTENT_LAST;
1256 	}
1257 
1258 	if (size) {
1259 		if (f2fs_encrypted_inode(inode))
1260 			flags |= FIEMAP_EXTENT_DATA_ENCRYPTED;
1261 
1262 		ret = fiemap_fill_next_extent(fieinfo, logical,
1263 				phys, size, flags);
1264 	}
1265 
1266 	if (start_blk > last_blk || ret)
1267 		goto out;
1268 
1269 	logical = blk_to_logical(inode, start_blk);
1270 	phys = blk_to_logical(inode, map_bh.b_blocknr);
1271 	size = map_bh.b_size;
1272 	flags = 0;
1273 	if (buffer_unwritten(&map_bh))
1274 		flags = FIEMAP_EXTENT_UNWRITTEN;
1275 
1276 	start_blk += logical_to_blk(inode, size);
1277 
1278 prep_next:
1279 	cond_resched();
1280 	if (fatal_signal_pending(current))
1281 		ret = -EINTR;
1282 	else
1283 		goto next;
1284 out:
1285 	if (ret == 1)
1286 		ret = 0;
1287 
1288 	inode_unlock(inode);
1289 	return ret;
1290 }
1291 
1292 /*
1293  * This function was originally taken from fs/mpage.c, and customized for f2fs.
1294  * Major change was from block_size == page_size in f2fs by default.
1295  */
1296 static int f2fs_mpage_readpages(struct address_space *mapping,
1297 			struct list_head *pages, struct page *page,
1298 			unsigned nr_pages)
1299 {
1300 	struct bio *bio = NULL;
1301 	sector_t last_block_in_bio = 0;
1302 	struct inode *inode = mapping->host;
1303 	const unsigned blkbits = inode->i_blkbits;
1304 	const unsigned blocksize = 1 << blkbits;
1305 	sector_t block_in_file;
1306 	sector_t last_block;
1307 	sector_t last_block_in_file;
1308 	sector_t block_nr;
1309 	struct f2fs_map_blocks map;
1310 
1311 	map.m_pblk = 0;
1312 	map.m_lblk = 0;
1313 	map.m_len = 0;
1314 	map.m_flags = 0;
1315 	map.m_next_pgofs = NULL;
1316 	map.m_seg_type = NO_CHECK_TYPE;
1317 
1318 	for (; nr_pages; nr_pages--) {
1319 		if (pages) {
1320 			page = list_last_entry(pages, struct page, lru);
1321 
1322 			prefetchw(&page->flags);
1323 			list_del(&page->lru);
1324 			if (add_to_page_cache_lru(page, mapping,
1325 						  page->index,
1326 						  readahead_gfp_mask(mapping)))
1327 				goto next_page;
1328 		}
1329 
1330 		block_in_file = (sector_t)page->index;
1331 		last_block = block_in_file + nr_pages;
1332 		last_block_in_file = (i_size_read(inode) + blocksize - 1) >>
1333 								blkbits;
1334 		if (last_block > last_block_in_file)
1335 			last_block = last_block_in_file;
1336 
1337 		/*
1338 		 * Map blocks using the previous result first.
1339 		 */
1340 		if ((map.m_flags & F2FS_MAP_MAPPED) &&
1341 				block_in_file > map.m_lblk &&
1342 				block_in_file < (map.m_lblk + map.m_len))
1343 			goto got_it;
1344 
1345 		/*
1346 		 * Then do more f2fs_map_blocks() calls until we are
1347 		 * done with this page.
1348 		 */
1349 		map.m_flags = 0;
1350 
1351 		if (block_in_file < last_block) {
1352 			map.m_lblk = block_in_file;
1353 			map.m_len = last_block - block_in_file;
1354 
1355 			if (f2fs_map_blocks(inode, &map, 0,
1356 						F2FS_GET_BLOCK_DEFAULT))
1357 				goto set_error_page;
1358 		}
1359 got_it:
1360 		if ((map.m_flags & F2FS_MAP_MAPPED)) {
1361 			block_nr = map.m_pblk + block_in_file - map.m_lblk;
1362 			SetPageMappedToDisk(page);
1363 
1364 			if (!PageUptodate(page) && !cleancache_get_page(page)) {
1365 				SetPageUptodate(page);
1366 				goto confused;
1367 			}
1368 		} else {
1369 			zero_user_segment(page, 0, PAGE_SIZE);
1370 			if (!PageUptodate(page))
1371 				SetPageUptodate(page);
1372 			unlock_page(page);
1373 			goto next_page;
1374 		}
1375 
1376 		/*
1377 		 * This page will go to BIO.  Do we need to send this
1378 		 * BIO off first?
1379 		 */
1380 		if (bio && (last_block_in_bio != block_nr - 1 ||
1381 			!__same_bdev(F2FS_I_SB(inode), block_nr, bio))) {
1382 submit_and_realloc:
1383 			__submit_bio(F2FS_I_SB(inode), bio, DATA);
1384 			bio = NULL;
1385 		}
1386 		if (bio == NULL) {
1387 			bio = f2fs_grab_read_bio(inode, block_nr, nr_pages);
1388 			if (IS_ERR(bio)) {
1389 				bio = NULL;
1390 				goto set_error_page;
1391 			}
1392 		}
1393 
1394 		if (bio_add_page(bio, page, blocksize, 0) < blocksize)
1395 			goto submit_and_realloc;
1396 
1397 		last_block_in_bio = block_nr;
1398 		goto next_page;
1399 set_error_page:
1400 		SetPageError(page);
1401 		zero_user_segment(page, 0, PAGE_SIZE);
1402 		unlock_page(page);
1403 		goto next_page;
1404 confused:
1405 		if (bio) {
1406 			__submit_bio(F2FS_I_SB(inode), bio, DATA);
1407 			bio = NULL;
1408 		}
1409 		unlock_page(page);
1410 next_page:
1411 		if (pages)
1412 			put_page(page);
1413 	}
1414 	BUG_ON(pages && !list_empty(pages));
1415 	if (bio)
1416 		__submit_bio(F2FS_I_SB(inode), bio, DATA);
1417 	return 0;
1418 }
1419 
1420 static int f2fs_read_data_page(struct file *file, struct page *page)
1421 {
1422 	struct inode *inode = page->mapping->host;
1423 	int ret = -EAGAIN;
1424 
1425 	trace_f2fs_readpage(page, DATA);
1426 
1427 	/* If the file has inline data, try to read it directly */
1428 	if (f2fs_has_inline_data(inode))
1429 		ret = f2fs_read_inline_data(inode, page);
1430 	if (ret == -EAGAIN)
1431 		ret = f2fs_mpage_readpages(page->mapping, NULL, page, 1);
1432 	return ret;
1433 }
1434 
1435 static int f2fs_read_data_pages(struct file *file,
1436 			struct address_space *mapping,
1437 			struct list_head *pages, unsigned nr_pages)
1438 {
1439 	struct inode *inode = mapping->host;
1440 	struct page *page = list_last_entry(pages, struct page, lru);
1441 
1442 	trace_f2fs_readpages(inode, page, nr_pages);
1443 
1444 	/* If the file has inline data, skip readpages */
1445 	if (f2fs_has_inline_data(inode))
1446 		return 0;
1447 
1448 	return f2fs_mpage_readpages(mapping, pages, NULL, nr_pages);
1449 }
1450 
1451 static int encrypt_one_page(struct f2fs_io_info *fio)
1452 {
1453 	struct inode *inode = fio->page->mapping->host;
1454 	gfp_t gfp_flags = GFP_NOFS;
1455 
1456 	if (!f2fs_encrypted_file(inode))
1457 		return 0;
1458 
1459 	/* wait for GCed encrypted page writeback */
1460 	f2fs_wait_on_block_writeback(fio->sbi, fio->old_blkaddr);
1461 
1462 retry_encrypt:
1463 	fio->encrypted_page = fscrypt_encrypt_page(inode, fio->page,
1464 			PAGE_SIZE, 0, fio->page->index, gfp_flags);
1465 	if (!IS_ERR(fio->encrypted_page))
1466 		return 0;
1467 
1468 	/* flush pending IOs and wait for a while in the ENOMEM case */
1469 	if (PTR_ERR(fio->encrypted_page) == -ENOMEM) {
1470 		f2fs_flush_merged_writes(fio->sbi);
1471 		congestion_wait(BLK_RW_ASYNC, HZ/50);
1472 		gfp_flags |= __GFP_NOFAIL;
1473 		goto retry_encrypt;
1474 	}
1475 	return PTR_ERR(fio->encrypted_page);
1476 }
1477 
1478 static inline bool need_inplace_update(struct f2fs_io_info *fio)
1479 {
1480 	struct inode *inode = fio->page->mapping->host;
1481 
1482 	if (f2fs_is_pinned_file(inode))
1483 		return true;
1484 	if (S_ISDIR(inode->i_mode) || f2fs_is_atomic_file(inode))
1485 		return false;
1486 	if (is_cold_data(fio->page))
1487 		return false;
1488 	if (IS_ATOMIC_WRITTEN_PAGE(fio->page))
1489 		return false;
1490 
1491 	return need_inplace_update_policy(inode, fio);
1492 }
1493 
1494 static inline bool valid_ipu_blkaddr(struct f2fs_io_info *fio)
1495 {
1496 	if (fio->old_blkaddr == NEW_ADDR)
1497 		return false;
1498 	if (fio->old_blkaddr == NULL_ADDR)
1499 		return false;
1500 	return true;
1501 }
1502 
1503 int do_write_data_page(struct f2fs_io_info *fio)
1504 {
1505 	struct page *page = fio->page;
1506 	struct inode *inode = page->mapping->host;
1507 	struct dnode_of_data dn;
1508 	struct extent_info ei = {0,0,0};
1509 	bool ipu_force = false;
1510 	int err = 0;
1511 
1512 	set_new_dnode(&dn, inode, NULL, NULL, 0);
1513 	if (need_inplace_update(fio) &&
1514 			f2fs_lookup_extent_cache(inode, page->index, &ei)) {
1515 		fio->old_blkaddr = ei.blk + page->index - ei.fofs;
1516 
1517 		if (valid_ipu_blkaddr(fio)) {
1518 			ipu_force = true;
1519 			fio->need_lock = LOCK_DONE;
1520 			goto got_it;
1521 		}
1522 	}
1523 
1524 	/* Deadlock due to between page->lock and f2fs_lock_op */
1525 	if (fio->need_lock == LOCK_REQ && !f2fs_trylock_op(fio->sbi))
1526 		return -EAGAIN;
1527 
1528 	err = get_dnode_of_data(&dn, page->index, LOOKUP_NODE);
1529 	if (err)
1530 		goto out;
1531 
1532 	fio->old_blkaddr = dn.data_blkaddr;
1533 
1534 	/* This page is already truncated */
1535 	if (fio->old_blkaddr == NULL_ADDR) {
1536 		ClearPageUptodate(page);
1537 		goto out_writepage;
1538 	}
1539 got_it:
1540 	/*
1541 	 * If current allocation needs SSR,
1542 	 * it had better in-place writes for updated data.
1543 	 */
1544 	if (ipu_force || (valid_ipu_blkaddr(fio) && need_inplace_update(fio))) {
1545 		err = encrypt_one_page(fio);
1546 		if (err)
1547 			goto out_writepage;
1548 
1549 		set_page_writeback(page);
1550 		f2fs_put_dnode(&dn);
1551 		if (fio->need_lock == LOCK_REQ)
1552 			f2fs_unlock_op(fio->sbi);
1553 		err = rewrite_data_page(fio);
1554 		trace_f2fs_do_write_data_page(fio->page, IPU);
1555 		set_inode_flag(inode, FI_UPDATE_WRITE);
1556 		return err;
1557 	}
1558 
1559 	if (fio->need_lock == LOCK_RETRY) {
1560 		if (!f2fs_trylock_op(fio->sbi)) {
1561 			err = -EAGAIN;
1562 			goto out_writepage;
1563 		}
1564 		fio->need_lock = LOCK_REQ;
1565 	}
1566 
1567 	err = encrypt_one_page(fio);
1568 	if (err)
1569 		goto out_writepage;
1570 
1571 	set_page_writeback(page);
1572 
1573 	/* LFS mode write path */
1574 	write_data_page(&dn, fio);
1575 	trace_f2fs_do_write_data_page(page, OPU);
1576 	set_inode_flag(inode, FI_APPEND_WRITE);
1577 	if (page->index == 0)
1578 		set_inode_flag(inode, FI_FIRST_BLOCK_WRITTEN);
1579 out_writepage:
1580 	f2fs_put_dnode(&dn);
1581 out:
1582 	if (fio->need_lock == LOCK_REQ)
1583 		f2fs_unlock_op(fio->sbi);
1584 	return err;
1585 }
1586 
1587 static int __write_data_page(struct page *page, bool *submitted,
1588 				struct writeback_control *wbc,
1589 				enum iostat_type io_type)
1590 {
1591 	struct inode *inode = page->mapping->host;
1592 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1593 	loff_t i_size = i_size_read(inode);
1594 	const pgoff_t end_index = ((unsigned long long) i_size)
1595 							>> PAGE_SHIFT;
1596 	loff_t psize = (page->index + 1) << PAGE_SHIFT;
1597 	unsigned offset = 0;
1598 	bool need_balance_fs = false;
1599 	int err = 0;
1600 	struct f2fs_io_info fio = {
1601 		.sbi = sbi,
1602 		.ino = inode->i_ino,
1603 		.type = DATA,
1604 		.op = REQ_OP_WRITE,
1605 		.op_flags = wbc_to_write_flags(wbc),
1606 		.old_blkaddr = NULL_ADDR,
1607 		.page = page,
1608 		.encrypted_page = NULL,
1609 		.submitted = false,
1610 		.need_lock = LOCK_RETRY,
1611 		.io_type = io_type,
1612 		.io_wbc = wbc,
1613 	};
1614 
1615 	trace_f2fs_writepage(page, DATA);
1616 
1617 	if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
1618 		goto redirty_out;
1619 
1620 	if (page->index < end_index)
1621 		goto write;
1622 
1623 	/*
1624 	 * If the offset is out-of-range of file size,
1625 	 * this page does not have to be written to disk.
1626 	 */
1627 	offset = i_size & (PAGE_SIZE - 1);
1628 	if ((page->index >= end_index + 1) || !offset)
1629 		goto out;
1630 
1631 	zero_user_segment(page, offset, PAGE_SIZE);
1632 write:
1633 	if (f2fs_is_drop_cache(inode))
1634 		goto out;
1635 	/* we should not write 0'th page having journal header */
1636 	if (f2fs_is_volatile_file(inode) && (!page->index ||
1637 			(!wbc->for_reclaim &&
1638 			available_free_memory(sbi, BASE_CHECK))))
1639 		goto redirty_out;
1640 
1641 	/* we should bypass data pages to proceed the kworkder jobs */
1642 	if (unlikely(f2fs_cp_error(sbi))) {
1643 		mapping_set_error(page->mapping, -EIO);
1644 		goto out;
1645 	}
1646 
1647 	/* Dentry blocks are controlled by checkpoint */
1648 	if (S_ISDIR(inode->i_mode)) {
1649 		fio.need_lock = LOCK_DONE;
1650 		err = do_write_data_page(&fio);
1651 		goto done;
1652 	}
1653 
1654 	if (!wbc->for_reclaim)
1655 		need_balance_fs = true;
1656 	else if (has_not_enough_free_secs(sbi, 0, 0))
1657 		goto redirty_out;
1658 	else
1659 		set_inode_flag(inode, FI_HOT_DATA);
1660 
1661 	err = -EAGAIN;
1662 	if (f2fs_has_inline_data(inode)) {
1663 		err = f2fs_write_inline_data(inode, page);
1664 		if (!err)
1665 			goto out;
1666 	}
1667 
1668 	if (err == -EAGAIN) {
1669 		err = do_write_data_page(&fio);
1670 		if (err == -EAGAIN) {
1671 			fio.need_lock = LOCK_REQ;
1672 			err = do_write_data_page(&fio);
1673 		}
1674 	}
1675 
1676 	down_write(&F2FS_I(inode)->i_sem);
1677 	if (F2FS_I(inode)->last_disk_size < psize)
1678 		F2FS_I(inode)->last_disk_size = psize;
1679 	up_write(&F2FS_I(inode)->i_sem);
1680 
1681 done:
1682 	if (err && err != -ENOENT)
1683 		goto redirty_out;
1684 
1685 out:
1686 	inode_dec_dirty_pages(inode);
1687 	if (err)
1688 		ClearPageUptodate(page);
1689 
1690 	if (wbc->for_reclaim) {
1691 		f2fs_submit_merged_write_cond(sbi, inode, 0, page->index, DATA);
1692 		clear_inode_flag(inode, FI_HOT_DATA);
1693 		remove_dirty_inode(inode);
1694 		submitted = NULL;
1695 	}
1696 
1697 	unlock_page(page);
1698 	if (!S_ISDIR(inode->i_mode))
1699 		f2fs_balance_fs(sbi, need_balance_fs);
1700 
1701 	if (unlikely(f2fs_cp_error(sbi))) {
1702 		f2fs_submit_merged_write(sbi, DATA);
1703 		submitted = NULL;
1704 	}
1705 
1706 	if (submitted)
1707 		*submitted = fio.submitted;
1708 
1709 	return 0;
1710 
1711 redirty_out:
1712 	redirty_page_for_writepage(wbc, page);
1713 	if (!err)
1714 		return AOP_WRITEPAGE_ACTIVATE;
1715 	unlock_page(page);
1716 	return err;
1717 }
1718 
1719 static int f2fs_write_data_page(struct page *page,
1720 					struct writeback_control *wbc)
1721 {
1722 	return __write_data_page(page, NULL, wbc, FS_DATA_IO);
1723 }
1724 
1725 /*
1726  * This function was copied from write_cche_pages from mm/page-writeback.c.
1727  * The major change is making write step of cold data page separately from
1728  * warm/hot data page.
1729  */
1730 static int f2fs_write_cache_pages(struct address_space *mapping,
1731 					struct writeback_control *wbc,
1732 					enum iostat_type io_type)
1733 {
1734 	int ret = 0;
1735 	int done = 0;
1736 	struct pagevec pvec;
1737 	int nr_pages;
1738 	pgoff_t uninitialized_var(writeback_index);
1739 	pgoff_t index;
1740 	pgoff_t end;		/* Inclusive */
1741 	pgoff_t done_index;
1742 	pgoff_t last_idx = ULONG_MAX;
1743 	int cycled;
1744 	int range_whole = 0;
1745 	int tag;
1746 
1747 	pagevec_init(&pvec);
1748 
1749 	if (get_dirty_pages(mapping->host) <=
1750 				SM_I(F2FS_M_SB(mapping))->min_hot_blocks)
1751 		set_inode_flag(mapping->host, FI_HOT_DATA);
1752 	else
1753 		clear_inode_flag(mapping->host, FI_HOT_DATA);
1754 
1755 	if (wbc->range_cyclic) {
1756 		writeback_index = mapping->writeback_index; /* prev offset */
1757 		index = writeback_index;
1758 		if (index == 0)
1759 			cycled = 1;
1760 		else
1761 			cycled = 0;
1762 		end = -1;
1763 	} else {
1764 		index = wbc->range_start >> PAGE_SHIFT;
1765 		end = wbc->range_end >> PAGE_SHIFT;
1766 		if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
1767 			range_whole = 1;
1768 		cycled = 1; /* ignore range_cyclic tests */
1769 	}
1770 	if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
1771 		tag = PAGECACHE_TAG_TOWRITE;
1772 	else
1773 		tag = PAGECACHE_TAG_DIRTY;
1774 retry:
1775 	if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
1776 		tag_pages_for_writeback(mapping, index, end);
1777 	done_index = index;
1778 	while (!done && (index <= end)) {
1779 		int i;
1780 
1781 		nr_pages = pagevec_lookup_range_tag(&pvec, mapping, &index, end,
1782 				tag);
1783 		if (nr_pages == 0)
1784 			break;
1785 
1786 		for (i = 0; i < nr_pages; i++) {
1787 			struct page *page = pvec.pages[i];
1788 			bool submitted = false;
1789 
1790 			done_index = page->index;
1791 retry_write:
1792 			lock_page(page);
1793 
1794 			if (unlikely(page->mapping != mapping)) {
1795 continue_unlock:
1796 				unlock_page(page);
1797 				continue;
1798 			}
1799 
1800 			if (!PageDirty(page)) {
1801 				/* someone wrote it for us */
1802 				goto continue_unlock;
1803 			}
1804 
1805 			if (PageWriteback(page)) {
1806 				if (wbc->sync_mode != WB_SYNC_NONE)
1807 					f2fs_wait_on_page_writeback(page,
1808 								DATA, true);
1809 				else
1810 					goto continue_unlock;
1811 			}
1812 
1813 			BUG_ON(PageWriteback(page));
1814 			if (!clear_page_dirty_for_io(page))
1815 				goto continue_unlock;
1816 
1817 			ret = __write_data_page(page, &submitted, wbc, io_type);
1818 			if (unlikely(ret)) {
1819 				/*
1820 				 * keep nr_to_write, since vfs uses this to
1821 				 * get # of written pages.
1822 				 */
1823 				if (ret == AOP_WRITEPAGE_ACTIVATE) {
1824 					unlock_page(page);
1825 					ret = 0;
1826 					continue;
1827 				} else if (ret == -EAGAIN) {
1828 					ret = 0;
1829 					if (wbc->sync_mode == WB_SYNC_ALL) {
1830 						cond_resched();
1831 						congestion_wait(BLK_RW_ASYNC,
1832 									HZ/50);
1833 						goto retry_write;
1834 					}
1835 					continue;
1836 				}
1837 				done_index = page->index + 1;
1838 				done = 1;
1839 				break;
1840 			} else if (submitted) {
1841 				last_idx = page->index;
1842 			}
1843 
1844 			/* give a priority to WB_SYNC threads */
1845 			if ((atomic_read(&F2FS_M_SB(mapping)->wb_sync_req) ||
1846 					--wbc->nr_to_write <= 0) &&
1847 					wbc->sync_mode == WB_SYNC_NONE) {
1848 				done = 1;
1849 				break;
1850 			}
1851 		}
1852 		pagevec_release(&pvec);
1853 		cond_resched();
1854 	}
1855 
1856 	if (!cycled && !done) {
1857 		cycled = 1;
1858 		index = 0;
1859 		end = writeback_index - 1;
1860 		goto retry;
1861 	}
1862 	if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
1863 		mapping->writeback_index = done_index;
1864 
1865 	if (last_idx != ULONG_MAX)
1866 		f2fs_submit_merged_write_cond(F2FS_M_SB(mapping), mapping->host,
1867 						0, last_idx, DATA);
1868 
1869 	return ret;
1870 }
1871 
1872 int __f2fs_write_data_pages(struct address_space *mapping,
1873 						struct writeback_control *wbc,
1874 						enum iostat_type io_type)
1875 {
1876 	struct inode *inode = mapping->host;
1877 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1878 	struct blk_plug plug;
1879 	int ret;
1880 
1881 	/* deal with chardevs and other special file */
1882 	if (!mapping->a_ops->writepage)
1883 		return 0;
1884 
1885 	/* skip writing if there is no dirty page in this inode */
1886 	if (!get_dirty_pages(inode) && wbc->sync_mode == WB_SYNC_NONE)
1887 		return 0;
1888 
1889 	/* during POR, we don't need to trigger writepage at all. */
1890 	if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
1891 		goto skip_write;
1892 
1893 	if (S_ISDIR(inode->i_mode) && wbc->sync_mode == WB_SYNC_NONE &&
1894 			get_dirty_pages(inode) < nr_pages_to_skip(sbi, DATA) &&
1895 			available_free_memory(sbi, DIRTY_DENTS))
1896 		goto skip_write;
1897 
1898 	/* skip writing during file defragment */
1899 	if (is_inode_flag_set(inode, FI_DO_DEFRAG))
1900 		goto skip_write;
1901 
1902 	trace_f2fs_writepages(mapping->host, wbc, DATA);
1903 
1904 	/* to avoid spliting IOs due to mixed WB_SYNC_ALL and WB_SYNC_NONE */
1905 	if (wbc->sync_mode == WB_SYNC_ALL)
1906 		atomic_inc(&sbi->wb_sync_req);
1907 	else if (atomic_read(&sbi->wb_sync_req))
1908 		goto skip_write;
1909 
1910 	blk_start_plug(&plug);
1911 	ret = f2fs_write_cache_pages(mapping, wbc, io_type);
1912 	blk_finish_plug(&plug);
1913 
1914 	if (wbc->sync_mode == WB_SYNC_ALL)
1915 		atomic_dec(&sbi->wb_sync_req);
1916 	/*
1917 	 * if some pages were truncated, we cannot guarantee its mapping->host
1918 	 * to detect pending bios.
1919 	 */
1920 
1921 	remove_dirty_inode(inode);
1922 	return ret;
1923 
1924 skip_write:
1925 	wbc->pages_skipped += get_dirty_pages(inode);
1926 	trace_f2fs_writepages(mapping->host, wbc, DATA);
1927 	return 0;
1928 }
1929 
1930 static int f2fs_write_data_pages(struct address_space *mapping,
1931 			    struct writeback_control *wbc)
1932 {
1933 	struct inode *inode = mapping->host;
1934 
1935 	return __f2fs_write_data_pages(mapping, wbc,
1936 			F2FS_I(inode)->cp_task == current ?
1937 			FS_CP_DATA_IO : FS_DATA_IO);
1938 }
1939 
1940 static void f2fs_write_failed(struct address_space *mapping, loff_t to)
1941 {
1942 	struct inode *inode = mapping->host;
1943 	loff_t i_size = i_size_read(inode);
1944 
1945 	if (to > i_size) {
1946 		down_write(&F2FS_I(inode)->i_mmap_sem);
1947 		truncate_pagecache(inode, i_size);
1948 		truncate_blocks(inode, i_size, true);
1949 		up_write(&F2FS_I(inode)->i_mmap_sem);
1950 	}
1951 }
1952 
1953 static int prepare_write_begin(struct f2fs_sb_info *sbi,
1954 			struct page *page, loff_t pos, unsigned len,
1955 			block_t *blk_addr, bool *node_changed)
1956 {
1957 	struct inode *inode = page->mapping->host;
1958 	pgoff_t index = page->index;
1959 	struct dnode_of_data dn;
1960 	struct page *ipage;
1961 	bool locked = false;
1962 	struct extent_info ei = {0,0,0};
1963 	int err = 0;
1964 
1965 	/*
1966 	 * we already allocated all the blocks, so we don't need to get
1967 	 * the block addresses when there is no need to fill the page.
1968 	 */
1969 	if (!f2fs_has_inline_data(inode) && len == PAGE_SIZE &&
1970 			!is_inode_flag_set(inode, FI_NO_PREALLOC))
1971 		return 0;
1972 
1973 	if (f2fs_has_inline_data(inode) ||
1974 			(pos & PAGE_MASK) >= i_size_read(inode)) {
1975 		__do_map_lock(sbi, F2FS_GET_BLOCK_PRE_AIO, true);
1976 		locked = true;
1977 	}
1978 restart:
1979 	/* check inline_data */
1980 	ipage = get_node_page(sbi, inode->i_ino);
1981 	if (IS_ERR(ipage)) {
1982 		err = PTR_ERR(ipage);
1983 		goto unlock_out;
1984 	}
1985 
1986 	set_new_dnode(&dn, inode, ipage, ipage, 0);
1987 
1988 	if (f2fs_has_inline_data(inode)) {
1989 		if (pos + len <= MAX_INLINE_DATA(inode)) {
1990 			read_inline_data(page, ipage);
1991 			set_inode_flag(inode, FI_DATA_EXIST);
1992 			if (inode->i_nlink)
1993 				set_inline_node(ipage);
1994 		} else {
1995 			err = f2fs_convert_inline_page(&dn, page);
1996 			if (err)
1997 				goto out;
1998 			if (dn.data_blkaddr == NULL_ADDR)
1999 				err = f2fs_get_block(&dn, index);
2000 		}
2001 	} else if (locked) {
2002 		err = f2fs_get_block(&dn, index);
2003 	} else {
2004 		if (f2fs_lookup_extent_cache(inode, index, &ei)) {
2005 			dn.data_blkaddr = ei.blk + index - ei.fofs;
2006 		} else {
2007 			/* hole case */
2008 			err = get_dnode_of_data(&dn, index, LOOKUP_NODE);
2009 			if (err || dn.data_blkaddr == NULL_ADDR) {
2010 				f2fs_put_dnode(&dn);
2011 				__do_map_lock(sbi, F2FS_GET_BLOCK_PRE_AIO,
2012 								true);
2013 				locked = true;
2014 				goto restart;
2015 			}
2016 		}
2017 	}
2018 
2019 	/* convert_inline_page can make node_changed */
2020 	*blk_addr = dn.data_blkaddr;
2021 	*node_changed = dn.node_changed;
2022 out:
2023 	f2fs_put_dnode(&dn);
2024 unlock_out:
2025 	if (locked)
2026 		__do_map_lock(sbi, F2FS_GET_BLOCK_PRE_AIO, false);
2027 	return err;
2028 }
2029 
2030 static int f2fs_write_begin(struct file *file, struct address_space *mapping,
2031 		loff_t pos, unsigned len, unsigned flags,
2032 		struct page **pagep, void **fsdata)
2033 {
2034 	struct inode *inode = mapping->host;
2035 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
2036 	struct page *page = NULL;
2037 	pgoff_t index = ((unsigned long long) pos) >> PAGE_SHIFT;
2038 	bool need_balance = false;
2039 	block_t blkaddr = NULL_ADDR;
2040 	int err = 0;
2041 
2042 	trace_f2fs_write_begin(inode, pos, len, flags);
2043 
2044 	if (f2fs_is_atomic_file(inode) &&
2045 			!available_free_memory(sbi, INMEM_PAGES)) {
2046 		err = -ENOMEM;
2047 		goto fail;
2048 	}
2049 
2050 	/*
2051 	 * We should check this at this moment to avoid deadlock on inode page
2052 	 * and #0 page. The locking rule for inline_data conversion should be:
2053 	 * lock_page(page #0) -> lock_page(inode_page)
2054 	 */
2055 	if (index != 0) {
2056 		err = f2fs_convert_inline_inode(inode);
2057 		if (err)
2058 			goto fail;
2059 	}
2060 repeat:
2061 	/*
2062 	 * Do not use grab_cache_page_write_begin() to avoid deadlock due to
2063 	 * wait_for_stable_page. Will wait that below with our IO control.
2064 	 */
2065 	page = f2fs_pagecache_get_page(mapping, index,
2066 				FGP_LOCK | FGP_WRITE | FGP_CREAT, GFP_NOFS);
2067 	if (!page) {
2068 		err = -ENOMEM;
2069 		goto fail;
2070 	}
2071 
2072 	*pagep = page;
2073 
2074 	err = prepare_write_begin(sbi, page, pos, len,
2075 					&blkaddr, &need_balance);
2076 	if (err)
2077 		goto fail;
2078 
2079 	if (need_balance && has_not_enough_free_secs(sbi, 0, 0)) {
2080 		unlock_page(page);
2081 		f2fs_balance_fs(sbi, true);
2082 		lock_page(page);
2083 		if (page->mapping != mapping) {
2084 			/* The page got truncated from under us */
2085 			f2fs_put_page(page, 1);
2086 			goto repeat;
2087 		}
2088 	}
2089 
2090 	f2fs_wait_on_page_writeback(page, DATA, false);
2091 
2092 	/* wait for GCed encrypted page writeback */
2093 	if (f2fs_encrypted_file(inode))
2094 		f2fs_wait_on_block_writeback(sbi, blkaddr);
2095 
2096 	if (len == PAGE_SIZE || PageUptodate(page))
2097 		return 0;
2098 
2099 	if (!(pos & (PAGE_SIZE - 1)) && (pos + len) >= i_size_read(inode)) {
2100 		zero_user_segment(page, len, PAGE_SIZE);
2101 		return 0;
2102 	}
2103 
2104 	if (blkaddr == NEW_ADDR) {
2105 		zero_user_segment(page, 0, PAGE_SIZE);
2106 		SetPageUptodate(page);
2107 	} else {
2108 		err = f2fs_submit_page_read(inode, page, blkaddr);
2109 		if (err)
2110 			goto fail;
2111 
2112 		lock_page(page);
2113 		if (unlikely(page->mapping != mapping)) {
2114 			f2fs_put_page(page, 1);
2115 			goto repeat;
2116 		}
2117 		if (unlikely(!PageUptodate(page))) {
2118 			err = -EIO;
2119 			goto fail;
2120 		}
2121 	}
2122 	return 0;
2123 
2124 fail:
2125 	f2fs_put_page(page, 1);
2126 	f2fs_write_failed(mapping, pos + len);
2127 	if (f2fs_is_atomic_file(inode))
2128 		drop_inmem_pages_all(sbi);
2129 	return err;
2130 }
2131 
2132 static int f2fs_write_end(struct file *file,
2133 			struct address_space *mapping,
2134 			loff_t pos, unsigned len, unsigned copied,
2135 			struct page *page, void *fsdata)
2136 {
2137 	struct inode *inode = page->mapping->host;
2138 
2139 	trace_f2fs_write_end(inode, pos, len, copied);
2140 
2141 	/*
2142 	 * This should be come from len == PAGE_SIZE, and we expect copied
2143 	 * should be PAGE_SIZE. Otherwise, we treat it with zero copied and
2144 	 * let generic_perform_write() try to copy data again through copied=0.
2145 	 */
2146 	if (!PageUptodate(page)) {
2147 		if (unlikely(copied != len))
2148 			copied = 0;
2149 		else
2150 			SetPageUptodate(page);
2151 	}
2152 	if (!copied)
2153 		goto unlock_out;
2154 
2155 	set_page_dirty(page);
2156 
2157 	if (pos + copied > i_size_read(inode))
2158 		f2fs_i_size_write(inode, pos + copied);
2159 unlock_out:
2160 	f2fs_put_page(page, 1);
2161 	f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
2162 	return copied;
2163 }
2164 
2165 static int check_direct_IO(struct inode *inode, struct iov_iter *iter,
2166 			   loff_t offset)
2167 {
2168 	unsigned blocksize_mask = inode->i_sb->s_blocksize - 1;
2169 
2170 	if (offset & blocksize_mask)
2171 		return -EINVAL;
2172 
2173 	if (iov_iter_alignment(iter) & blocksize_mask)
2174 		return -EINVAL;
2175 
2176 	return 0;
2177 }
2178 
2179 static ssize_t f2fs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
2180 {
2181 	struct address_space *mapping = iocb->ki_filp->f_mapping;
2182 	struct inode *inode = mapping->host;
2183 	size_t count = iov_iter_count(iter);
2184 	loff_t offset = iocb->ki_pos;
2185 	int rw = iov_iter_rw(iter);
2186 	int err;
2187 
2188 	err = check_direct_IO(inode, iter, offset);
2189 	if (err)
2190 		return err;
2191 
2192 	if (__force_buffered_io(inode, rw))
2193 		return 0;
2194 
2195 	trace_f2fs_direct_IO_enter(inode, offset, count, rw);
2196 
2197 	down_read(&F2FS_I(inode)->dio_rwsem[rw]);
2198 	err = blockdev_direct_IO(iocb, inode, iter, get_data_block_dio);
2199 	up_read(&F2FS_I(inode)->dio_rwsem[rw]);
2200 
2201 	if (rw == WRITE) {
2202 		if (err > 0) {
2203 			f2fs_update_iostat(F2FS_I_SB(inode), APP_DIRECT_IO,
2204 									err);
2205 			set_inode_flag(inode, FI_UPDATE_WRITE);
2206 		} else if (err < 0) {
2207 			f2fs_write_failed(mapping, offset + count);
2208 		}
2209 	}
2210 
2211 	trace_f2fs_direct_IO_exit(inode, offset, count, rw, err);
2212 
2213 	return err;
2214 }
2215 
2216 void f2fs_invalidate_page(struct page *page, unsigned int offset,
2217 							unsigned int length)
2218 {
2219 	struct inode *inode = page->mapping->host;
2220 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
2221 
2222 	if (inode->i_ino >= F2FS_ROOT_INO(sbi) &&
2223 		(offset % PAGE_SIZE || length != PAGE_SIZE))
2224 		return;
2225 
2226 	if (PageDirty(page)) {
2227 		if (inode->i_ino == F2FS_META_INO(sbi)) {
2228 			dec_page_count(sbi, F2FS_DIRTY_META);
2229 		} else if (inode->i_ino == F2FS_NODE_INO(sbi)) {
2230 			dec_page_count(sbi, F2FS_DIRTY_NODES);
2231 		} else {
2232 			inode_dec_dirty_pages(inode);
2233 			remove_dirty_inode(inode);
2234 		}
2235 	}
2236 
2237 	/* This is atomic written page, keep Private */
2238 	if (IS_ATOMIC_WRITTEN_PAGE(page))
2239 		return drop_inmem_page(inode, page);
2240 
2241 	set_page_private(page, 0);
2242 	ClearPagePrivate(page);
2243 }
2244 
2245 int f2fs_release_page(struct page *page, gfp_t wait)
2246 {
2247 	/* If this is dirty page, keep PagePrivate */
2248 	if (PageDirty(page))
2249 		return 0;
2250 
2251 	/* This is atomic written page, keep Private */
2252 	if (IS_ATOMIC_WRITTEN_PAGE(page))
2253 		return 0;
2254 
2255 	set_page_private(page, 0);
2256 	ClearPagePrivate(page);
2257 	return 1;
2258 }
2259 
2260 /*
2261  * This was copied from __set_page_dirty_buffers which gives higher performance
2262  * in very high speed storages. (e.g., pmem)
2263  */
2264 void f2fs_set_page_dirty_nobuffers(struct page *page)
2265 {
2266 	struct address_space *mapping = page->mapping;
2267 	unsigned long flags;
2268 
2269 	if (unlikely(!mapping))
2270 		return;
2271 
2272 	spin_lock(&mapping->private_lock);
2273 	lock_page_memcg(page);
2274 	SetPageDirty(page);
2275 	spin_unlock(&mapping->private_lock);
2276 
2277 	spin_lock_irqsave(&mapping->tree_lock, flags);
2278 	WARN_ON_ONCE(!PageUptodate(page));
2279 	account_page_dirtied(page, mapping);
2280 	radix_tree_tag_set(&mapping->page_tree,
2281 			page_index(page), PAGECACHE_TAG_DIRTY);
2282 	spin_unlock_irqrestore(&mapping->tree_lock, flags);
2283 	unlock_page_memcg(page);
2284 
2285 	__mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
2286 	return;
2287 }
2288 
2289 static int f2fs_set_data_page_dirty(struct page *page)
2290 {
2291 	struct address_space *mapping = page->mapping;
2292 	struct inode *inode = mapping->host;
2293 
2294 	trace_f2fs_set_page_dirty(page, DATA);
2295 
2296 	if (!PageUptodate(page))
2297 		SetPageUptodate(page);
2298 
2299 	if (f2fs_is_atomic_file(inode) && !f2fs_is_commit_atomic_write(inode)) {
2300 		if (!IS_ATOMIC_WRITTEN_PAGE(page)) {
2301 			register_inmem_page(inode, page);
2302 			return 1;
2303 		}
2304 		/*
2305 		 * Previously, this page has been registered, we just
2306 		 * return here.
2307 		 */
2308 		return 0;
2309 	}
2310 
2311 	if (!PageDirty(page)) {
2312 		f2fs_set_page_dirty_nobuffers(page);
2313 		update_dirty_page(inode, page);
2314 		return 1;
2315 	}
2316 	return 0;
2317 }
2318 
2319 static sector_t f2fs_bmap(struct address_space *mapping, sector_t block)
2320 {
2321 	struct inode *inode = mapping->host;
2322 
2323 	if (f2fs_has_inline_data(inode))
2324 		return 0;
2325 
2326 	/* make sure allocating whole blocks */
2327 	if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
2328 		filemap_write_and_wait(mapping);
2329 
2330 	return generic_block_bmap(mapping, block, get_data_block_bmap);
2331 }
2332 
2333 #ifdef CONFIG_MIGRATION
2334 #include <linux/migrate.h>
2335 
2336 int f2fs_migrate_page(struct address_space *mapping,
2337 		struct page *newpage, struct page *page, enum migrate_mode mode)
2338 {
2339 	int rc, extra_count;
2340 	struct f2fs_inode_info *fi = F2FS_I(mapping->host);
2341 	bool atomic_written = IS_ATOMIC_WRITTEN_PAGE(page);
2342 
2343 	BUG_ON(PageWriteback(page));
2344 
2345 	/* migrating an atomic written page is safe with the inmem_lock hold */
2346 	if (atomic_written) {
2347 		if (mode != MIGRATE_SYNC)
2348 			return -EBUSY;
2349 		if (!mutex_trylock(&fi->inmem_lock))
2350 			return -EAGAIN;
2351 	}
2352 
2353 	/*
2354 	 * A reference is expected if PagePrivate set when move mapping,
2355 	 * however F2FS breaks this for maintaining dirty page counts when
2356 	 * truncating pages. So here adjusting the 'extra_count' make it work.
2357 	 */
2358 	extra_count = (atomic_written ? 1 : 0) - page_has_private(page);
2359 	rc = migrate_page_move_mapping(mapping, newpage,
2360 				page, NULL, mode, extra_count);
2361 	if (rc != MIGRATEPAGE_SUCCESS) {
2362 		if (atomic_written)
2363 			mutex_unlock(&fi->inmem_lock);
2364 		return rc;
2365 	}
2366 
2367 	if (atomic_written) {
2368 		struct inmem_pages *cur;
2369 		list_for_each_entry(cur, &fi->inmem_pages, list)
2370 			if (cur->page == page) {
2371 				cur->page = newpage;
2372 				break;
2373 			}
2374 		mutex_unlock(&fi->inmem_lock);
2375 		put_page(page);
2376 		get_page(newpage);
2377 	}
2378 
2379 	if (PagePrivate(page))
2380 		SetPagePrivate(newpage);
2381 	set_page_private(newpage, page_private(page));
2382 
2383 	if (mode != MIGRATE_SYNC_NO_COPY)
2384 		migrate_page_copy(newpage, page);
2385 	else
2386 		migrate_page_states(newpage, page);
2387 
2388 	return MIGRATEPAGE_SUCCESS;
2389 }
2390 #endif
2391 
2392 const struct address_space_operations f2fs_dblock_aops = {
2393 	.readpage	= f2fs_read_data_page,
2394 	.readpages	= f2fs_read_data_pages,
2395 	.writepage	= f2fs_write_data_page,
2396 	.writepages	= f2fs_write_data_pages,
2397 	.write_begin	= f2fs_write_begin,
2398 	.write_end	= f2fs_write_end,
2399 	.set_page_dirty	= f2fs_set_data_page_dirty,
2400 	.invalidatepage	= f2fs_invalidate_page,
2401 	.releasepage	= f2fs_release_page,
2402 	.direct_IO	= f2fs_direct_IO,
2403 	.bmap		= f2fs_bmap,
2404 #ifdef CONFIG_MIGRATION
2405 	.migratepage    = f2fs_migrate_page,
2406 #endif
2407 };
2408