xref: /openbmc/linux/fs/f2fs/data.c (revision 2baf07818549c8bb8d7b3437e889b86eab56d38e)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * fs/f2fs/data.c
4  *
5  * Copyright (c) 2012 Samsung Electronics Co., Ltd.
6  *             http://www.samsung.com/
7  */
8 #include <linux/fs.h>
9 #include <linux/f2fs_fs.h>
10 #include <linux/buffer_head.h>
11 #include <linux/mpage.h>
12 #include <linux/writeback.h>
13 #include <linux/backing-dev.h>
14 #include <linux/pagevec.h>
15 #include <linux/blkdev.h>
16 #include <linux/bio.h>
17 #include <linux/prefetch.h>
18 #include <linux/uio.h>
19 #include <linux/cleancache.h>
20 #include <linux/sched/signal.h>
21 
22 #include "f2fs.h"
23 #include "node.h"
24 #include "segment.h"
25 #include "trace.h"
26 #include <trace/events/f2fs.h>
27 
28 #define NUM_PREALLOC_POST_READ_CTXS	128
29 
30 static struct kmem_cache *bio_post_read_ctx_cache;
31 static mempool_t *bio_post_read_ctx_pool;
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 			(S_ISREG(inode->i_mode) &&
49 			is_inode_flag_set(inode, FI_ATOMIC_FILE)) ||
50 			is_cold_data(page))
51 		return true;
52 	return false;
53 }
54 
55 static enum count_type __read_io_type(struct page *page)
56 {
57 	struct address_space *mapping = page->mapping;
58 
59 	if (mapping) {
60 		struct inode *inode = mapping->host;
61 		struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
62 
63 		if (inode->i_ino == F2FS_META_INO(sbi))
64 			return F2FS_RD_META;
65 
66 		if (inode->i_ino == F2FS_NODE_INO(sbi))
67 			return F2FS_RD_NODE;
68 	}
69 	return F2FS_RD_DATA;
70 }
71 
72 /* postprocessing steps for read bios */
73 enum bio_post_read_step {
74 	STEP_INITIAL = 0,
75 	STEP_DECRYPT,
76 };
77 
78 struct bio_post_read_ctx {
79 	struct bio *bio;
80 	struct work_struct work;
81 	unsigned int cur_step;
82 	unsigned int enabled_steps;
83 };
84 
85 static void __read_end_io(struct bio *bio)
86 {
87 	struct page *page;
88 	struct bio_vec *bv;
89 	int i;
90 
91 	bio_for_each_segment_all(bv, bio, i) {
92 		page = bv->bv_page;
93 
94 		/* PG_error was set if any post_read step failed */
95 		if (bio->bi_status || PageError(page)) {
96 			ClearPageUptodate(page);
97 			/* will re-read again later */
98 			ClearPageError(page);
99 		} else {
100 			SetPageUptodate(page);
101 		}
102 		dec_page_count(F2FS_P_SB(page), __read_io_type(page));
103 		unlock_page(page);
104 	}
105 	if (bio->bi_private)
106 		mempool_free(bio->bi_private, bio_post_read_ctx_pool);
107 	bio_put(bio);
108 }
109 
110 static void bio_post_read_processing(struct bio_post_read_ctx *ctx);
111 
112 static void decrypt_work(struct work_struct *work)
113 {
114 	struct bio_post_read_ctx *ctx =
115 		container_of(work, struct bio_post_read_ctx, work);
116 
117 	fscrypt_decrypt_bio(ctx->bio);
118 
119 	bio_post_read_processing(ctx);
120 }
121 
122 static void bio_post_read_processing(struct bio_post_read_ctx *ctx)
123 {
124 	switch (++ctx->cur_step) {
125 	case STEP_DECRYPT:
126 		if (ctx->enabled_steps & (1 << STEP_DECRYPT)) {
127 			INIT_WORK(&ctx->work, decrypt_work);
128 			fscrypt_enqueue_decrypt_work(&ctx->work);
129 			return;
130 		}
131 		ctx->cur_step++;
132 		/* fall-through */
133 	default:
134 		__read_end_io(ctx->bio);
135 	}
136 }
137 
138 static bool f2fs_bio_post_read_required(struct bio *bio)
139 {
140 	return bio->bi_private && !bio->bi_status;
141 }
142 
143 static void f2fs_read_end_io(struct bio *bio)
144 {
145 	if (time_to_inject(F2FS_P_SB(bio_first_page_all(bio)),
146 						FAULT_READ_IO)) {
147 		f2fs_show_injection_info(FAULT_READ_IO);
148 		bio->bi_status = BLK_STS_IOERR;
149 	}
150 
151 	if (f2fs_bio_post_read_required(bio)) {
152 		struct bio_post_read_ctx *ctx = bio->bi_private;
153 
154 		ctx->cur_step = STEP_INITIAL;
155 		bio_post_read_processing(ctx);
156 		return;
157 	}
158 
159 	__read_end_io(bio);
160 }
161 
162 static void f2fs_write_end_io(struct bio *bio)
163 {
164 	struct f2fs_sb_info *sbi = bio->bi_private;
165 	struct bio_vec *bvec;
166 	int i;
167 
168 	if (time_to_inject(sbi, FAULT_WRITE_IO)) {
169 		f2fs_show_injection_info(FAULT_WRITE_IO);
170 		bio->bi_status = BLK_STS_IOERR;
171 	}
172 
173 	bio_for_each_segment_all(bvec, bio, i) {
174 		struct page *page = bvec->bv_page;
175 		enum count_type type = WB_DATA_TYPE(page);
176 
177 		if (IS_DUMMY_WRITTEN_PAGE(page)) {
178 			set_page_private(page, (unsigned long)NULL);
179 			ClearPagePrivate(page);
180 			unlock_page(page);
181 			mempool_free(page, sbi->write_io_dummy);
182 
183 			if (unlikely(bio->bi_status))
184 				f2fs_stop_checkpoint(sbi, true);
185 			continue;
186 		}
187 
188 		fscrypt_pullback_bio_page(&page, true);
189 
190 		if (unlikely(bio->bi_status)) {
191 			mapping_set_error(page->mapping, -EIO);
192 			if (type == F2FS_WB_CP_DATA)
193 				f2fs_stop_checkpoint(sbi, true);
194 		}
195 
196 		f2fs_bug_on(sbi, page->mapping == NODE_MAPPING(sbi) &&
197 					page->index != nid_of_node(page));
198 
199 		dec_page_count(sbi, type);
200 		if (f2fs_in_warm_node_list(sbi, page))
201 			f2fs_del_fsync_node_entry(sbi, page);
202 		clear_cold_data(page);
203 		end_page_writeback(page);
204 	}
205 	if (!get_pages(sbi, F2FS_WB_CP_DATA) &&
206 				wq_has_sleeper(&sbi->cp_wait))
207 		wake_up(&sbi->cp_wait);
208 
209 	bio_put(bio);
210 }
211 
212 /*
213  * Return true, if pre_bio's bdev is same as its target device.
214  */
215 struct block_device *f2fs_target_device(struct f2fs_sb_info *sbi,
216 				block_t blk_addr, struct bio *bio)
217 {
218 	struct block_device *bdev = sbi->sb->s_bdev;
219 	int i;
220 
221 	for (i = 0; i < sbi->s_ndevs; i++) {
222 		if (FDEV(i).start_blk <= blk_addr &&
223 					FDEV(i).end_blk >= blk_addr) {
224 			blk_addr -= FDEV(i).start_blk;
225 			bdev = FDEV(i).bdev;
226 			break;
227 		}
228 	}
229 	if (bio) {
230 		bio_set_dev(bio, bdev);
231 		bio->bi_iter.bi_sector = SECTOR_FROM_BLOCK(blk_addr);
232 	}
233 	return bdev;
234 }
235 
236 int f2fs_target_device_index(struct f2fs_sb_info *sbi, block_t blkaddr)
237 {
238 	int i;
239 
240 	for (i = 0; i < sbi->s_ndevs; i++)
241 		if (FDEV(i).start_blk <= blkaddr && FDEV(i).end_blk >= blkaddr)
242 			return i;
243 	return 0;
244 }
245 
246 static bool __same_bdev(struct f2fs_sb_info *sbi,
247 				block_t blk_addr, struct bio *bio)
248 {
249 	struct block_device *b = f2fs_target_device(sbi, blk_addr, NULL);
250 	return bio->bi_disk == b->bd_disk && bio->bi_partno == b->bd_partno;
251 }
252 
253 /*
254  * Low-level block read/write IO operations.
255  */
256 static struct bio *__bio_alloc(struct f2fs_sb_info *sbi, block_t blk_addr,
257 				struct writeback_control *wbc,
258 				int npages, bool is_read,
259 				enum page_type type, enum temp_type temp)
260 {
261 	struct bio *bio;
262 
263 	bio = f2fs_bio_alloc(sbi, npages, true);
264 
265 	f2fs_target_device(sbi, blk_addr, bio);
266 	if (is_read) {
267 		bio->bi_end_io = f2fs_read_end_io;
268 		bio->bi_private = NULL;
269 	} else {
270 		bio->bi_end_io = f2fs_write_end_io;
271 		bio->bi_private = sbi;
272 		bio->bi_write_hint = f2fs_io_type_to_rw_hint(sbi, type, temp);
273 	}
274 	if (wbc)
275 		wbc_init_bio(wbc, bio);
276 
277 	return bio;
278 }
279 
280 static inline void __submit_bio(struct f2fs_sb_info *sbi,
281 				struct bio *bio, enum page_type type)
282 {
283 	if (!is_read_io(bio_op(bio))) {
284 		unsigned int start;
285 
286 		if (type != DATA && type != NODE)
287 			goto submit_io;
288 
289 		if (test_opt(sbi, LFS) && current->plug)
290 			blk_finish_plug(current->plug);
291 
292 		start = bio->bi_iter.bi_size >> F2FS_BLKSIZE_BITS;
293 		start %= F2FS_IO_SIZE(sbi);
294 
295 		if (start == 0)
296 			goto submit_io;
297 
298 		/* fill dummy pages */
299 		for (; start < F2FS_IO_SIZE(sbi); start++) {
300 			struct page *page =
301 				mempool_alloc(sbi->write_io_dummy,
302 					GFP_NOIO | __GFP_ZERO | __GFP_NOFAIL);
303 			f2fs_bug_on(sbi, !page);
304 
305 			SetPagePrivate(page);
306 			set_page_private(page, (unsigned long)DUMMY_WRITTEN_PAGE);
307 			lock_page(page);
308 			if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE)
309 				f2fs_bug_on(sbi, 1);
310 		}
311 		/*
312 		 * In the NODE case, we lose next block address chain. So, we
313 		 * need to do checkpoint in f2fs_sync_file.
314 		 */
315 		if (type == NODE)
316 			set_sbi_flag(sbi, SBI_NEED_CP);
317 	}
318 submit_io:
319 	if (is_read_io(bio_op(bio)))
320 		trace_f2fs_submit_read_bio(sbi->sb, type, bio);
321 	else
322 		trace_f2fs_submit_write_bio(sbi->sb, type, bio);
323 	submit_bio(bio);
324 }
325 
326 static void __submit_merged_bio(struct f2fs_bio_info *io)
327 {
328 	struct f2fs_io_info *fio = &io->fio;
329 
330 	if (!io->bio)
331 		return;
332 
333 	bio_set_op_attrs(io->bio, fio->op, fio->op_flags);
334 
335 	if (is_read_io(fio->op))
336 		trace_f2fs_prepare_read_bio(io->sbi->sb, fio->type, io->bio);
337 	else
338 		trace_f2fs_prepare_write_bio(io->sbi->sb, fio->type, io->bio);
339 
340 	__submit_bio(io->sbi, io->bio, fio->type);
341 	io->bio = NULL;
342 }
343 
344 static bool __has_merged_page(struct f2fs_bio_info *io, struct inode *inode,
345 						struct page *page, nid_t ino)
346 {
347 	struct bio_vec *bvec;
348 	struct page *target;
349 	int i;
350 
351 	if (!io->bio)
352 		return false;
353 
354 	if (!inode && !page && !ino)
355 		return true;
356 
357 	bio_for_each_segment_all(bvec, io->bio, i) {
358 
359 		if (bvec->bv_page->mapping)
360 			target = bvec->bv_page;
361 		else
362 			target = fscrypt_control_page(bvec->bv_page);
363 
364 		if (inode && inode == target->mapping->host)
365 			return true;
366 		if (page && page == target)
367 			return true;
368 		if (ino && ino == ino_of_node(target))
369 			return true;
370 	}
371 
372 	return false;
373 }
374 
375 static bool has_merged_page(struct f2fs_sb_info *sbi, struct inode *inode,
376 						struct page *page, nid_t ino,
377 						enum page_type type)
378 {
379 	enum page_type btype = PAGE_TYPE_OF_BIO(type);
380 	enum temp_type temp;
381 	struct f2fs_bio_info *io;
382 	bool ret = false;
383 
384 	for (temp = HOT; temp < NR_TEMP_TYPE; temp++) {
385 		io = sbi->write_io[btype] + temp;
386 
387 		down_read(&io->io_rwsem);
388 		ret = __has_merged_page(io, inode, page, ino);
389 		up_read(&io->io_rwsem);
390 
391 		/* TODO: use HOT temp only for meta pages now. */
392 		if (ret || btype == META)
393 			break;
394 	}
395 	return ret;
396 }
397 
398 static void __f2fs_submit_merged_write(struct f2fs_sb_info *sbi,
399 				enum page_type type, enum temp_type temp)
400 {
401 	enum page_type btype = PAGE_TYPE_OF_BIO(type);
402 	struct f2fs_bio_info *io = sbi->write_io[btype] + temp;
403 
404 	down_write(&io->io_rwsem);
405 
406 	/* change META to META_FLUSH in the checkpoint procedure */
407 	if (type >= META_FLUSH) {
408 		io->fio.type = META_FLUSH;
409 		io->fio.op = REQ_OP_WRITE;
410 		io->fio.op_flags = REQ_META | REQ_PRIO | REQ_SYNC;
411 		if (!test_opt(sbi, NOBARRIER))
412 			io->fio.op_flags |= REQ_PREFLUSH | REQ_FUA;
413 	}
414 	__submit_merged_bio(io);
415 	up_write(&io->io_rwsem);
416 }
417 
418 static void __submit_merged_write_cond(struct f2fs_sb_info *sbi,
419 				struct inode *inode, struct page *page,
420 				nid_t ino, enum page_type type, bool force)
421 {
422 	enum temp_type temp;
423 
424 	if (!force && !has_merged_page(sbi, inode, page, ino, type))
425 		return;
426 
427 	for (temp = HOT; temp < NR_TEMP_TYPE; temp++) {
428 
429 		__f2fs_submit_merged_write(sbi, type, temp);
430 
431 		/* TODO: use HOT temp only for meta pages now. */
432 		if (type >= META)
433 			break;
434 	}
435 }
436 
437 void f2fs_submit_merged_write(struct f2fs_sb_info *sbi, enum page_type type)
438 {
439 	__submit_merged_write_cond(sbi, NULL, 0, 0, type, true);
440 }
441 
442 void f2fs_submit_merged_write_cond(struct f2fs_sb_info *sbi,
443 				struct inode *inode, struct page *page,
444 				nid_t ino, enum page_type type)
445 {
446 	__submit_merged_write_cond(sbi, inode, page, ino, type, false);
447 }
448 
449 void f2fs_flush_merged_writes(struct f2fs_sb_info *sbi)
450 {
451 	f2fs_submit_merged_write(sbi, DATA);
452 	f2fs_submit_merged_write(sbi, NODE);
453 	f2fs_submit_merged_write(sbi, META);
454 }
455 
456 /*
457  * Fill the locked page with data located in the block address.
458  * A caller needs to unlock the page on failure.
459  */
460 int f2fs_submit_page_bio(struct f2fs_io_info *fio)
461 {
462 	struct bio *bio;
463 	struct page *page = fio->encrypted_page ?
464 			fio->encrypted_page : fio->page;
465 
466 	if (!f2fs_is_valid_blkaddr(fio->sbi, fio->new_blkaddr,
467 			__is_meta_io(fio) ? META_GENERIC : DATA_GENERIC))
468 		return -EFAULT;
469 
470 	trace_f2fs_submit_page_bio(page, fio);
471 	f2fs_trace_ios(fio, 0);
472 
473 	/* Allocate a new bio */
474 	bio = __bio_alloc(fio->sbi, fio->new_blkaddr, fio->io_wbc,
475 				1, is_read_io(fio->op), fio->type, fio->temp);
476 
477 	if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
478 		bio_put(bio);
479 		return -EFAULT;
480 	}
481 
482 	if (fio->io_wbc && !is_read_io(fio->op))
483 		wbc_account_io(fio->io_wbc, page, PAGE_SIZE);
484 
485 	bio_set_op_attrs(bio, fio->op, fio->op_flags);
486 
487 	inc_page_count(fio->sbi, is_read_io(fio->op) ?
488 			__read_io_type(page): WB_DATA_TYPE(fio->page));
489 
490 	__submit_bio(fio->sbi, bio, fio->type);
491 	return 0;
492 }
493 
494 void f2fs_submit_page_write(struct f2fs_io_info *fio)
495 {
496 	struct f2fs_sb_info *sbi = fio->sbi;
497 	enum page_type btype = PAGE_TYPE_OF_BIO(fio->type);
498 	struct f2fs_bio_info *io = sbi->write_io[btype] + fio->temp;
499 	struct page *bio_page;
500 
501 	f2fs_bug_on(sbi, is_read_io(fio->op));
502 
503 	down_write(&io->io_rwsem);
504 next:
505 	if (fio->in_list) {
506 		spin_lock(&io->io_lock);
507 		if (list_empty(&io->io_list)) {
508 			spin_unlock(&io->io_lock);
509 			goto out;
510 		}
511 		fio = list_first_entry(&io->io_list,
512 						struct f2fs_io_info, list);
513 		list_del(&fio->list);
514 		spin_unlock(&io->io_lock);
515 	}
516 
517 	if (__is_valid_data_blkaddr(fio->old_blkaddr))
518 		verify_block_addr(fio, fio->old_blkaddr);
519 	verify_block_addr(fio, fio->new_blkaddr);
520 
521 	bio_page = fio->encrypted_page ? fio->encrypted_page : fio->page;
522 
523 	/* set submitted = true as a return value */
524 	fio->submitted = true;
525 
526 	inc_page_count(sbi, WB_DATA_TYPE(bio_page));
527 
528 	if (io->bio && (io->last_block_in_bio != fio->new_blkaddr - 1 ||
529 	    (io->fio.op != fio->op || io->fio.op_flags != fio->op_flags) ||
530 			!__same_bdev(sbi, fio->new_blkaddr, io->bio)))
531 		__submit_merged_bio(io);
532 alloc_new:
533 	if (io->bio == NULL) {
534 		if ((fio->type == DATA || fio->type == NODE) &&
535 				fio->new_blkaddr & F2FS_IO_SIZE_MASK(sbi)) {
536 			dec_page_count(sbi, WB_DATA_TYPE(bio_page));
537 			fio->retry = true;
538 			goto skip;
539 		}
540 		io->bio = __bio_alloc(sbi, fio->new_blkaddr, fio->io_wbc,
541 						BIO_MAX_PAGES, false,
542 						fio->type, fio->temp);
543 		io->fio = *fio;
544 	}
545 
546 	if (bio_add_page(io->bio, bio_page, PAGE_SIZE, 0) < PAGE_SIZE) {
547 		__submit_merged_bio(io);
548 		goto alloc_new;
549 	}
550 
551 	if (fio->io_wbc)
552 		wbc_account_io(fio->io_wbc, bio_page, PAGE_SIZE);
553 
554 	io->last_block_in_bio = fio->new_blkaddr;
555 	f2fs_trace_ios(fio, 0);
556 
557 	trace_f2fs_submit_page_write(fio->page, fio);
558 skip:
559 	if (fio->in_list)
560 		goto next;
561 out:
562 	if (is_sbi_flag_set(sbi, SBI_IS_SHUTDOWN) ||
563 				f2fs_is_checkpoint_ready(sbi))
564 		__submit_merged_bio(io);
565 	up_write(&io->io_rwsem);
566 }
567 
568 static struct bio *f2fs_grab_read_bio(struct inode *inode, block_t blkaddr,
569 					unsigned nr_pages, unsigned op_flag)
570 {
571 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
572 	struct bio *bio;
573 	struct bio_post_read_ctx *ctx;
574 	unsigned int post_read_steps = 0;
575 
576 	if (!f2fs_is_valid_blkaddr(sbi, blkaddr, DATA_GENERIC))
577 		return ERR_PTR(-EFAULT);
578 
579 	bio = f2fs_bio_alloc(sbi, min_t(int, nr_pages, BIO_MAX_PAGES), false);
580 	if (!bio)
581 		return ERR_PTR(-ENOMEM);
582 	f2fs_target_device(sbi, blkaddr, bio);
583 	bio->bi_end_io = f2fs_read_end_io;
584 	bio_set_op_attrs(bio, REQ_OP_READ, op_flag);
585 
586 	if (f2fs_encrypted_file(inode))
587 		post_read_steps |= 1 << STEP_DECRYPT;
588 	if (post_read_steps) {
589 		ctx = mempool_alloc(bio_post_read_ctx_pool, GFP_NOFS);
590 		if (!ctx) {
591 			bio_put(bio);
592 			return ERR_PTR(-ENOMEM);
593 		}
594 		ctx->bio = bio;
595 		ctx->enabled_steps = post_read_steps;
596 		bio->bi_private = ctx;
597 	}
598 
599 	return bio;
600 }
601 
602 /* This can handle encryption stuffs */
603 static int f2fs_submit_page_read(struct inode *inode, struct page *page,
604 							block_t blkaddr)
605 {
606 	struct bio *bio = f2fs_grab_read_bio(inode, blkaddr, 1, 0);
607 
608 	if (IS_ERR(bio))
609 		return PTR_ERR(bio);
610 
611 	/* wait for GCed page writeback via META_MAPPING */
612 	f2fs_wait_on_block_writeback(inode, blkaddr);
613 
614 	if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
615 		bio_put(bio);
616 		return -EFAULT;
617 	}
618 	ClearPageError(page);
619 	inc_page_count(F2FS_I_SB(inode), F2FS_RD_DATA);
620 	__submit_bio(F2FS_I_SB(inode), bio, DATA);
621 	return 0;
622 }
623 
624 static void __set_data_blkaddr(struct dnode_of_data *dn)
625 {
626 	struct f2fs_node *rn = F2FS_NODE(dn->node_page);
627 	__le32 *addr_array;
628 	int base = 0;
629 
630 	if (IS_INODE(dn->node_page) && f2fs_has_extra_attr(dn->inode))
631 		base = get_extra_isize(dn->inode);
632 
633 	/* Get physical address of data block */
634 	addr_array = blkaddr_in_node(rn);
635 	addr_array[base + dn->ofs_in_node] = cpu_to_le32(dn->data_blkaddr);
636 }
637 
638 /*
639  * Lock ordering for the change of data block address:
640  * ->data_page
641  *  ->node_page
642  *    update block addresses in the node page
643  */
644 void f2fs_set_data_blkaddr(struct dnode_of_data *dn)
645 {
646 	f2fs_wait_on_page_writeback(dn->node_page, NODE, true);
647 	__set_data_blkaddr(dn);
648 	if (set_page_dirty(dn->node_page))
649 		dn->node_changed = true;
650 }
651 
652 void f2fs_update_data_blkaddr(struct dnode_of_data *dn, block_t blkaddr)
653 {
654 	dn->data_blkaddr = blkaddr;
655 	f2fs_set_data_blkaddr(dn);
656 	f2fs_update_extent_cache(dn);
657 }
658 
659 /* dn->ofs_in_node will be returned with up-to-date last block pointer */
660 int f2fs_reserve_new_blocks(struct dnode_of_data *dn, blkcnt_t count)
661 {
662 	struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
663 	int err;
664 
665 	if (!count)
666 		return 0;
667 
668 	if (unlikely(is_inode_flag_set(dn->inode, FI_NO_ALLOC)))
669 		return -EPERM;
670 	if (unlikely((err = inc_valid_block_count(sbi, dn->inode, &count))))
671 		return err;
672 
673 	trace_f2fs_reserve_new_blocks(dn->inode, dn->nid,
674 						dn->ofs_in_node, count);
675 
676 	f2fs_wait_on_page_writeback(dn->node_page, NODE, true);
677 
678 	for (; count > 0; dn->ofs_in_node++) {
679 		block_t blkaddr = datablock_addr(dn->inode,
680 					dn->node_page, dn->ofs_in_node);
681 		if (blkaddr == NULL_ADDR) {
682 			dn->data_blkaddr = NEW_ADDR;
683 			__set_data_blkaddr(dn);
684 			count--;
685 		}
686 	}
687 
688 	if (set_page_dirty(dn->node_page))
689 		dn->node_changed = true;
690 	return 0;
691 }
692 
693 /* Should keep dn->ofs_in_node unchanged */
694 int f2fs_reserve_new_block(struct dnode_of_data *dn)
695 {
696 	unsigned int ofs_in_node = dn->ofs_in_node;
697 	int ret;
698 
699 	ret = f2fs_reserve_new_blocks(dn, 1);
700 	dn->ofs_in_node = ofs_in_node;
701 	return ret;
702 }
703 
704 int f2fs_reserve_block(struct dnode_of_data *dn, pgoff_t index)
705 {
706 	bool need_put = dn->inode_page ? false : true;
707 	int err;
708 
709 	err = f2fs_get_dnode_of_data(dn, index, ALLOC_NODE);
710 	if (err)
711 		return err;
712 
713 	if (dn->data_blkaddr == NULL_ADDR)
714 		err = f2fs_reserve_new_block(dn);
715 	if (err || need_put)
716 		f2fs_put_dnode(dn);
717 	return err;
718 }
719 
720 int f2fs_get_block(struct dnode_of_data *dn, pgoff_t index)
721 {
722 	struct extent_info ei  = {0,0,0};
723 	struct inode *inode = dn->inode;
724 
725 	if (f2fs_lookup_extent_cache(inode, index, &ei)) {
726 		dn->data_blkaddr = ei.blk + index - ei.fofs;
727 		return 0;
728 	}
729 
730 	return f2fs_reserve_block(dn, index);
731 }
732 
733 struct page *f2fs_get_read_data_page(struct inode *inode, pgoff_t index,
734 						int op_flags, bool for_write)
735 {
736 	struct address_space *mapping = inode->i_mapping;
737 	struct dnode_of_data dn;
738 	struct page *page;
739 	struct extent_info ei = {0,0,0};
740 	int err;
741 
742 	page = f2fs_grab_cache_page(mapping, index, for_write);
743 	if (!page)
744 		return ERR_PTR(-ENOMEM);
745 
746 	if (f2fs_lookup_extent_cache(inode, index, &ei)) {
747 		dn.data_blkaddr = ei.blk + index - ei.fofs;
748 		goto got_it;
749 	}
750 
751 	set_new_dnode(&dn, inode, NULL, NULL, 0);
752 	err = f2fs_get_dnode_of_data(&dn, index, LOOKUP_NODE);
753 	if (err)
754 		goto put_err;
755 	f2fs_put_dnode(&dn);
756 
757 	if (unlikely(dn.data_blkaddr == NULL_ADDR)) {
758 		err = -ENOENT;
759 		goto put_err;
760 	}
761 got_it:
762 	if (PageUptodate(page)) {
763 		unlock_page(page);
764 		return page;
765 	}
766 
767 	/*
768 	 * A new dentry page is allocated but not able to be written, since its
769 	 * new inode page couldn't be allocated due to -ENOSPC.
770 	 * In such the case, its blkaddr can be remained as NEW_ADDR.
771 	 * see, f2fs_add_link -> f2fs_get_new_data_page ->
772 	 * f2fs_init_inode_metadata.
773 	 */
774 	if (dn.data_blkaddr == NEW_ADDR) {
775 		zero_user_segment(page, 0, PAGE_SIZE);
776 		if (!PageUptodate(page))
777 			SetPageUptodate(page);
778 		unlock_page(page);
779 		return page;
780 	}
781 
782 	err = f2fs_submit_page_read(inode, page, dn.data_blkaddr);
783 	if (err)
784 		goto put_err;
785 	return page;
786 
787 put_err:
788 	f2fs_put_page(page, 1);
789 	return ERR_PTR(err);
790 }
791 
792 struct page *f2fs_find_data_page(struct inode *inode, pgoff_t index)
793 {
794 	struct address_space *mapping = inode->i_mapping;
795 	struct page *page;
796 
797 	page = find_get_page(mapping, index);
798 	if (page && PageUptodate(page))
799 		return page;
800 	f2fs_put_page(page, 0);
801 
802 	page = f2fs_get_read_data_page(inode, index, 0, false);
803 	if (IS_ERR(page))
804 		return page;
805 
806 	if (PageUptodate(page))
807 		return page;
808 
809 	wait_on_page_locked(page);
810 	if (unlikely(!PageUptodate(page))) {
811 		f2fs_put_page(page, 0);
812 		return ERR_PTR(-EIO);
813 	}
814 	return page;
815 }
816 
817 /*
818  * If it tries to access a hole, return an error.
819  * Because, the callers, functions in dir.c and GC, should be able to know
820  * whether this page exists or not.
821  */
822 struct page *f2fs_get_lock_data_page(struct inode *inode, pgoff_t index,
823 							bool for_write)
824 {
825 	struct address_space *mapping = inode->i_mapping;
826 	struct page *page;
827 repeat:
828 	page = f2fs_get_read_data_page(inode, index, 0, for_write);
829 	if (IS_ERR(page))
830 		return page;
831 
832 	/* wait for read completion */
833 	lock_page(page);
834 	if (unlikely(page->mapping != mapping)) {
835 		f2fs_put_page(page, 1);
836 		goto repeat;
837 	}
838 	if (unlikely(!PageUptodate(page))) {
839 		f2fs_put_page(page, 1);
840 		return ERR_PTR(-EIO);
841 	}
842 	return page;
843 }
844 
845 /*
846  * Caller ensures that this data page is never allocated.
847  * A new zero-filled data page is allocated in the page cache.
848  *
849  * Also, caller should grab and release a rwsem by calling f2fs_lock_op() and
850  * f2fs_unlock_op().
851  * Note that, ipage is set only by make_empty_dir, and if any error occur,
852  * ipage should be released by this function.
853  */
854 struct page *f2fs_get_new_data_page(struct inode *inode,
855 		struct page *ipage, pgoff_t index, bool new_i_size)
856 {
857 	struct address_space *mapping = inode->i_mapping;
858 	struct page *page;
859 	struct dnode_of_data dn;
860 	int err;
861 
862 	page = f2fs_grab_cache_page(mapping, index, true);
863 	if (!page) {
864 		/*
865 		 * before exiting, we should make sure ipage will be released
866 		 * if any error occur.
867 		 */
868 		f2fs_put_page(ipage, 1);
869 		return ERR_PTR(-ENOMEM);
870 	}
871 
872 	set_new_dnode(&dn, inode, ipage, NULL, 0);
873 	err = f2fs_reserve_block(&dn, index);
874 	if (err) {
875 		f2fs_put_page(page, 1);
876 		return ERR_PTR(err);
877 	}
878 	if (!ipage)
879 		f2fs_put_dnode(&dn);
880 
881 	if (PageUptodate(page))
882 		goto got_it;
883 
884 	if (dn.data_blkaddr == NEW_ADDR) {
885 		zero_user_segment(page, 0, PAGE_SIZE);
886 		if (!PageUptodate(page))
887 			SetPageUptodate(page);
888 	} else {
889 		f2fs_put_page(page, 1);
890 
891 		/* if ipage exists, blkaddr should be NEW_ADDR */
892 		f2fs_bug_on(F2FS_I_SB(inode), ipage);
893 		page = f2fs_get_lock_data_page(inode, index, true);
894 		if (IS_ERR(page))
895 			return page;
896 	}
897 got_it:
898 	if (new_i_size && i_size_read(inode) <
899 				((loff_t)(index + 1) << PAGE_SHIFT))
900 		f2fs_i_size_write(inode, ((loff_t)(index + 1) << PAGE_SHIFT));
901 	return page;
902 }
903 
904 static int __allocate_data_block(struct dnode_of_data *dn, int seg_type)
905 {
906 	struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
907 	struct f2fs_summary sum;
908 	struct node_info ni;
909 	block_t old_blkaddr;
910 	blkcnt_t count = 1;
911 	int err;
912 
913 	if (unlikely(is_inode_flag_set(dn->inode, FI_NO_ALLOC)))
914 		return -EPERM;
915 
916 	err = f2fs_get_node_info(sbi, dn->nid, &ni);
917 	if (err)
918 		return err;
919 
920 	dn->data_blkaddr = datablock_addr(dn->inode,
921 				dn->node_page, dn->ofs_in_node);
922 	if (dn->data_blkaddr != NULL_ADDR)
923 		goto alloc;
924 
925 	if (unlikely((err = inc_valid_block_count(sbi, dn->inode, &count))))
926 		return err;
927 
928 alloc:
929 	set_summary(&sum, dn->nid, dn->ofs_in_node, ni.version);
930 	old_blkaddr = dn->data_blkaddr;
931 	f2fs_allocate_data_block(sbi, NULL, old_blkaddr, &dn->data_blkaddr,
932 					&sum, seg_type, NULL, false);
933 	if (GET_SEGNO(sbi, old_blkaddr) != NULL_SEGNO)
934 		invalidate_mapping_pages(META_MAPPING(sbi),
935 					old_blkaddr, old_blkaddr);
936 	f2fs_set_data_blkaddr(dn);
937 
938 	/*
939 	 * i_size will be updated by direct_IO. Otherwise, we'll get stale
940 	 * data from unwritten block via dio_read.
941 	 */
942 	return 0;
943 }
944 
945 int f2fs_preallocate_blocks(struct kiocb *iocb, struct iov_iter *from)
946 {
947 	struct inode *inode = file_inode(iocb->ki_filp);
948 	struct f2fs_map_blocks map;
949 	int flag;
950 	int err = 0;
951 	bool direct_io = iocb->ki_flags & IOCB_DIRECT;
952 
953 	/* convert inline data for Direct I/O*/
954 	if (direct_io) {
955 		err = f2fs_convert_inline_inode(inode);
956 		if (err)
957 			return err;
958 	}
959 
960 	if (is_inode_flag_set(inode, FI_NO_PREALLOC))
961 		return 0;
962 
963 	map.m_lblk = F2FS_BLK_ALIGN(iocb->ki_pos);
964 	map.m_len = F2FS_BYTES_TO_BLK(iocb->ki_pos + iov_iter_count(from));
965 	if (map.m_len > map.m_lblk)
966 		map.m_len -= map.m_lblk;
967 	else
968 		map.m_len = 0;
969 
970 	map.m_next_pgofs = NULL;
971 	map.m_next_extent = NULL;
972 	map.m_seg_type = NO_CHECK_TYPE;
973 
974 	if (direct_io) {
975 		map.m_seg_type = f2fs_rw_hint_to_seg_type(iocb->ki_hint);
976 		flag = f2fs_force_buffered_io(inode, iocb, from) ?
977 					F2FS_GET_BLOCK_PRE_AIO :
978 					F2FS_GET_BLOCK_PRE_DIO;
979 		goto map_blocks;
980 	}
981 	if (iocb->ki_pos + iov_iter_count(from) > MAX_INLINE_DATA(inode)) {
982 		err = f2fs_convert_inline_inode(inode);
983 		if (err)
984 			return err;
985 	}
986 	if (f2fs_has_inline_data(inode))
987 		return err;
988 
989 	flag = F2FS_GET_BLOCK_PRE_AIO;
990 
991 map_blocks:
992 	err = f2fs_map_blocks(inode, &map, 1, flag);
993 	if (map.m_len > 0 && err == -ENOSPC) {
994 		if (!direct_io)
995 			set_inode_flag(inode, FI_NO_PREALLOC);
996 		err = 0;
997 	}
998 	return err;
999 }
1000 
1001 void __do_map_lock(struct f2fs_sb_info *sbi, int flag, bool lock)
1002 {
1003 	if (flag == F2FS_GET_BLOCK_PRE_AIO) {
1004 		if (lock)
1005 			down_read(&sbi->node_change);
1006 		else
1007 			up_read(&sbi->node_change);
1008 	} else {
1009 		if (lock)
1010 			f2fs_lock_op(sbi);
1011 		else
1012 			f2fs_unlock_op(sbi);
1013 	}
1014 }
1015 
1016 /*
1017  * f2fs_map_blocks() now supported readahead/bmap/rw direct_IO with
1018  * f2fs_map_blocks structure.
1019  * If original data blocks are allocated, then give them to blockdev.
1020  * Otherwise,
1021  *     a. preallocate requested block addresses
1022  *     b. do not use extent cache for better performance
1023  *     c. give the block addresses to blockdev
1024  */
1025 int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map,
1026 						int create, int flag)
1027 {
1028 	unsigned int maxblocks = map->m_len;
1029 	struct dnode_of_data dn;
1030 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1031 	int mode = create ? ALLOC_NODE : LOOKUP_NODE;
1032 	pgoff_t pgofs, end_offset, end;
1033 	int err = 0, ofs = 1;
1034 	unsigned int ofs_in_node, last_ofs_in_node;
1035 	blkcnt_t prealloc;
1036 	struct extent_info ei = {0,0,0};
1037 	block_t blkaddr;
1038 	unsigned int start_pgofs;
1039 
1040 	if (!maxblocks)
1041 		return 0;
1042 
1043 	map->m_len = 0;
1044 	map->m_flags = 0;
1045 
1046 	/* it only supports block size == page size */
1047 	pgofs =	(pgoff_t)map->m_lblk;
1048 	end = pgofs + maxblocks;
1049 
1050 	if (!create && f2fs_lookup_extent_cache(inode, pgofs, &ei)) {
1051 		map->m_pblk = ei.blk + pgofs - ei.fofs;
1052 		map->m_len = min((pgoff_t)maxblocks, ei.fofs + ei.len - pgofs);
1053 		map->m_flags = F2FS_MAP_MAPPED;
1054 		if (map->m_next_extent)
1055 			*map->m_next_extent = pgofs + map->m_len;
1056 		goto out;
1057 	}
1058 
1059 next_dnode:
1060 	if (create)
1061 		__do_map_lock(sbi, flag, true);
1062 
1063 	/* When reading holes, we need its node page */
1064 	set_new_dnode(&dn, inode, NULL, NULL, 0);
1065 	err = f2fs_get_dnode_of_data(&dn, pgofs, mode);
1066 	if (err) {
1067 		if (flag == F2FS_GET_BLOCK_BMAP)
1068 			map->m_pblk = 0;
1069 		if (err == -ENOENT) {
1070 			err = 0;
1071 			if (map->m_next_pgofs)
1072 				*map->m_next_pgofs =
1073 					f2fs_get_next_page_offset(&dn, pgofs);
1074 			if (map->m_next_extent)
1075 				*map->m_next_extent =
1076 					f2fs_get_next_page_offset(&dn, pgofs);
1077 		}
1078 		goto unlock_out;
1079 	}
1080 
1081 	start_pgofs = pgofs;
1082 	prealloc = 0;
1083 	last_ofs_in_node = ofs_in_node = dn.ofs_in_node;
1084 	end_offset = ADDRS_PER_PAGE(dn.node_page, inode);
1085 
1086 next_block:
1087 	blkaddr = datablock_addr(dn.inode, dn.node_page, dn.ofs_in_node);
1088 
1089 	if (__is_valid_data_blkaddr(blkaddr) &&
1090 		!f2fs_is_valid_blkaddr(sbi, blkaddr, DATA_GENERIC)) {
1091 		err = -EFAULT;
1092 		goto sync_out;
1093 	}
1094 
1095 	if (is_valid_data_blkaddr(sbi, blkaddr)) {
1096 		/* use out-place-update for driect IO under LFS mode */
1097 		if (test_opt(sbi, LFS) && create &&
1098 				flag == F2FS_GET_BLOCK_DIO) {
1099 			err = __allocate_data_block(&dn, map->m_seg_type);
1100 			if (!err)
1101 				set_inode_flag(inode, FI_APPEND_WRITE);
1102 		}
1103 	} else {
1104 		if (create) {
1105 			if (unlikely(f2fs_cp_error(sbi))) {
1106 				err = -EIO;
1107 				goto sync_out;
1108 			}
1109 			if (flag == F2FS_GET_BLOCK_PRE_AIO) {
1110 				if (blkaddr == NULL_ADDR) {
1111 					prealloc++;
1112 					last_ofs_in_node = dn.ofs_in_node;
1113 				}
1114 			} else {
1115 				WARN_ON(flag != F2FS_GET_BLOCK_PRE_DIO &&
1116 					flag != F2FS_GET_BLOCK_DIO);
1117 				err = __allocate_data_block(&dn,
1118 							map->m_seg_type);
1119 				if (!err)
1120 					set_inode_flag(inode, FI_APPEND_WRITE);
1121 			}
1122 			if (err)
1123 				goto sync_out;
1124 			map->m_flags |= F2FS_MAP_NEW;
1125 			blkaddr = dn.data_blkaddr;
1126 		} else {
1127 			if (flag == F2FS_GET_BLOCK_BMAP) {
1128 				map->m_pblk = 0;
1129 				goto sync_out;
1130 			}
1131 			if (flag == F2FS_GET_BLOCK_PRECACHE)
1132 				goto sync_out;
1133 			if (flag == F2FS_GET_BLOCK_FIEMAP &&
1134 						blkaddr == NULL_ADDR) {
1135 				if (map->m_next_pgofs)
1136 					*map->m_next_pgofs = pgofs + 1;
1137 				goto sync_out;
1138 			}
1139 			if (flag != F2FS_GET_BLOCK_FIEMAP) {
1140 				/* for defragment case */
1141 				if (map->m_next_pgofs)
1142 					*map->m_next_pgofs = pgofs + 1;
1143 				goto sync_out;
1144 			}
1145 		}
1146 	}
1147 
1148 	if (flag == F2FS_GET_BLOCK_PRE_AIO)
1149 		goto skip;
1150 
1151 	if (map->m_len == 0) {
1152 		/* preallocated unwritten block should be mapped for fiemap. */
1153 		if (blkaddr == NEW_ADDR)
1154 			map->m_flags |= F2FS_MAP_UNWRITTEN;
1155 		map->m_flags |= F2FS_MAP_MAPPED;
1156 
1157 		map->m_pblk = blkaddr;
1158 		map->m_len = 1;
1159 	} else if ((map->m_pblk != NEW_ADDR &&
1160 			blkaddr == (map->m_pblk + ofs)) ||
1161 			(map->m_pblk == NEW_ADDR && blkaddr == NEW_ADDR) ||
1162 			flag == F2FS_GET_BLOCK_PRE_DIO) {
1163 		ofs++;
1164 		map->m_len++;
1165 	} else {
1166 		goto sync_out;
1167 	}
1168 
1169 skip:
1170 	dn.ofs_in_node++;
1171 	pgofs++;
1172 
1173 	/* preallocate blocks in batch for one dnode page */
1174 	if (flag == F2FS_GET_BLOCK_PRE_AIO &&
1175 			(pgofs == end || dn.ofs_in_node == end_offset)) {
1176 
1177 		dn.ofs_in_node = ofs_in_node;
1178 		err = f2fs_reserve_new_blocks(&dn, prealloc);
1179 		if (err)
1180 			goto sync_out;
1181 
1182 		map->m_len += dn.ofs_in_node - ofs_in_node;
1183 		if (prealloc && dn.ofs_in_node != last_ofs_in_node + 1) {
1184 			err = -ENOSPC;
1185 			goto sync_out;
1186 		}
1187 		dn.ofs_in_node = end_offset;
1188 	}
1189 
1190 	if (pgofs >= end)
1191 		goto sync_out;
1192 	else if (dn.ofs_in_node < end_offset)
1193 		goto next_block;
1194 
1195 	if (flag == F2FS_GET_BLOCK_PRECACHE) {
1196 		if (map->m_flags & F2FS_MAP_MAPPED) {
1197 			unsigned int ofs = start_pgofs - map->m_lblk;
1198 
1199 			f2fs_update_extent_cache_range(&dn,
1200 				start_pgofs, map->m_pblk + ofs,
1201 				map->m_len - ofs);
1202 		}
1203 	}
1204 
1205 	f2fs_put_dnode(&dn);
1206 
1207 	if (create) {
1208 		__do_map_lock(sbi, flag, false);
1209 		f2fs_balance_fs(sbi, dn.node_changed);
1210 	}
1211 	goto next_dnode;
1212 
1213 sync_out:
1214 	if (flag == F2FS_GET_BLOCK_PRECACHE) {
1215 		if (map->m_flags & F2FS_MAP_MAPPED) {
1216 			unsigned int ofs = start_pgofs - map->m_lblk;
1217 
1218 			f2fs_update_extent_cache_range(&dn,
1219 				start_pgofs, map->m_pblk + ofs,
1220 				map->m_len - ofs);
1221 		}
1222 		if (map->m_next_extent)
1223 			*map->m_next_extent = pgofs + 1;
1224 	}
1225 	f2fs_put_dnode(&dn);
1226 unlock_out:
1227 	if (create) {
1228 		__do_map_lock(sbi, flag, false);
1229 		f2fs_balance_fs(sbi, dn.node_changed);
1230 	}
1231 out:
1232 	trace_f2fs_map_blocks(inode, map, err);
1233 	return err;
1234 }
1235 
1236 bool f2fs_overwrite_io(struct inode *inode, loff_t pos, size_t len)
1237 {
1238 	struct f2fs_map_blocks map;
1239 	block_t last_lblk;
1240 	int err;
1241 
1242 	if (pos + len > i_size_read(inode))
1243 		return false;
1244 
1245 	map.m_lblk = F2FS_BYTES_TO_BLK(pos);
1246 	map.m_next_pgofs = NULL;
1247 	map.m_next_extent = NULL;
1248 	map.m_seg_type = NO_CHECK_TYPE;
1249 	last_lblk = F2FS_BLK_ALIGN(pos + len);
1250 
1251 	while (map.m_lblk < last_lblk) {
1252 		map.m_len = last_lblk - map.m_lblk;
1253 		err = f2fs_map_blocks(inode, &map, 0, F2FS_GET_BLOCK_DEFAULT);
1254 		if (err || map.m_len == 0)
1255 			return false;
1256 		map.m_lblk += map.m_len;
1257 	}
1258 	return true;
1259 }
1260 
1261 static int __get_data_block(struct inode *inode, sector_t iblock,
1262 			struct buffer_head *bh, int create, int flag,
1263 			pgoff_t *next_pgofs, int seg_type)
1264 {
1265 	struct f2fs_map_blocks map;
1266 	int err;
1267 
1268 	map.m_lblk = iblock;
1269 	map.m_len = bh->b_size >> inode->i_blkbits;
1270 	map.m_next_pgofs = next_pgofs;
1271 	map.m_next_extent = NULL;
1272 	map.m_seg_type = seg_type;
1273 
1274 	err = f2fs_map_blocks(inode, &map, create, flag);
1275 	if (!err) {
1276 		map_bh(bh, inode->i_sb, map.m_pblk);
1277 		bh->b_state = (bh->b_state & ~F2FS_MAP_FLAGS) | map.m_flags;
1278 		bh->b_size = (u64)map.m_len << inode->i_blkbits;
1279 	}
1280 	return err;
1281 }
1282 
1283 static int get_data_block(struct inode *inode, sector_t iblock,
1284 			struct buffer_head *bh_result, int create, int flag,
1285 			pgoff_t *next_pgofs)
1286 {
1287 	return __get_data_block(inode, iblock, bh_result, create,
1288 							flag, next_pgofs,
1289 							NO_CHECK_TYPE);
1290 }
1291 
1292 static int get_data_block_dio(struct inode *inode, sector_t iblock,
1293 			struct buffer_head *bh_result, int create)
1294 {
1295 	return __get_data_block(inode, iblock, bh_result, create,
1296 						F2FS_GET_BLOCK_DIO, NULL,
1297 						f2fs_rw_hint_to_seg_type(
1298 							inode->i_write_hint));
1299 }
1300 
1301 static int get_data_block_bmap(struct inode *inode, sector_t iblock,
1302 			struct buffer_head *bh_result, int create)
1303 {
1304 	/* Block number less than F2FS MAX BLOCKS */
1305 	if (unlikely(iblock >= F2FS_I_SB(inode)->max_file_blocks))
1306 		return -EFBIG;
1307 
1308 	return __get_data_block(inode, iblock, bh_result, create,
1309 						F2FS_GET_BLOCK_BMAP, NULL,
1310 						NO_CHECK_TYPE);
1311 }
1312 
1313 static inline sector_t logical_to_blk(struct inode *inode, loff_t offset)
1314 {
1315 	return (offset >> inode->i_blkbits);
1316 }
1317 
1318 static inline loff_t blk_to_logical(struct inode *inode, sector_t blk)
1319 {
1320 	return (blk << inode->i_blkbits);
1321 }
1322 
1323 static int f2fs_xattr_fiemap(struct inode *inode,
1324 				struct fiemap_extent_info *fieinfo)
1325 {
1326 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1327 	struct page *page;
1328 	struct node_info ni;
1329 	__u64 phys = 0, len;
1330 	__u32 flags;
1331 	nid_t xnid = F2FS_I(inode)->i_xattr_nid;
1332 	int err = 0;
1333 
1334 	if (f2fs_has_inline_xattr(inode)) {
1335 		int offset;
1336 
1337 		page = f2fs_grab_cache_page(NODE_MAPPING(sbi),
1338 						inode->i_ino, false);
1339 		if (!page)
1340 			return -ENOMEM;
1341 
1342 		err = f2fs_get_node_info(sbi, inode->i_ino, &ni);
1343 		if (err) {
1344 			f2fs_put_page(page, 1);
1345 			return err;
1346 		}
1347 
1348 		phys = (__u64)blk_to_logical(inode, ni.blk_addr);
1349 		offset = offsetof(struct f2fs_inode, i_addr) +
1350 					sizeof(__le32) * (DEF_ADDRS_PER_INODE -
1351 					get_inline_xattr_addrs(inode));
1352 
1353 		phys += offset;
1354 		len = inline_xattr_size(inode);
1355 
1356 		f2fs_put_page(page, 1);
1357 
1358 		flags = FIEMAP_EXTENT_DATA_INLINE | FIEMAP_EXTENT_NOT_ALIGNED;
1359 
1360 		if (!xnid)
1361 			flags |= FIEMAP_EXTENT_LAST;
1362 
1363 		err = fiemap_fill_next_extent(fieinfo, 0, phys, len, flags);
1364 		if (err || err == 1)
1365 			return err;
1366 	}
1367 
1368 	if (xnid) {
1369 		page = f2fs_grab_cache_page(NODE_MAPPING(sbi), xnid, false);
1370 		if (!page)
1371 			return -ENOMEM;
1372 
1373 		err = f2fs_get_node_info(sbi, xnid, &ni);
1374 		if (err) {
1375 			f2fs_put_page(page, 1);
1376 			return err;
1377 		}
1378 
1379 		phys = (__u64)blk_to_logical(inode, ni.blk_addr);
1380 		len = inode->i_sb->s_blocksize;
1381 
1382 		f2fs_put_page(page, 1);
1383 
1384 		flags = FIEMAP_EXTENT_LAST;
1385 	}
1386 
1387 	if (phys)
1388 		err = fiemap_fill_next_extent(fieinfo, 0, phys, len, flags);
1389 
1390 	return (err < 0 ? err : 0);
1391 }
1392 
1393 int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
1394 		u64 start, u64 len)
1395 {
1396 	struct buffer_head map_bh;
1397 	sector_t start_blk, last_blk;
1398 	pgoff_t next_pgofs;
1399 	u64 logical = 0, phys = 0, size = 0;
1400 	u32 flags = 0;
1401 	int ret = 0;
1402 
1403 	if (fieinfo->fi_flags & FIEMAP_FLAG_CACHE) {
1404 		ret = f2fs_precache_extents(inode);
1405 		if (ret)
1406 			return ret;
1407 	}
1408 
1409 	ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC | FIEMAP_FLAG_XATTR);
1410 	if (ret)
1411 		return ret;
1412 
1413 	inode_lock(inode);
1414 
1415 	if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) {
1416 		ret = f2fs_xattr_fiemap(inode, fieinfo);
1417 		goto out;
1418 	}
1419 
1420 	if (f2fs_has_inline_data(inode)) {
1421 		ret = f2fs_inline_data_fiemap(inode, fieinfo, start, len);
1422 		if (ret != -EAGAIN)
1423 			goto out;
1424 	}
1425 
1426 	if (logical_to_blk(inode, len) == 0)
1427 		len = blk_to_logical(inode, 1);
1428 
1429 	start_blk = logical_to_blk(inode, start);
1430 	last_blk = logical_to_blk(inode, start + len - 1);
1431 
1432 next:
1433 	memset(&map_bh, 0, sizeof(struct buffer_head));
1434 	map_bh.b_size = len;
1435 
1436 	ret = get_data_block(inode, start_blk, &map_bh, 0,
1437 					F2FS_GET_BLOCK_FIEMAP, &next_pgofs);
1438 	if (ret)
1439 		goto out;
1440 
1441 	/* HOLE */
1442 	if (!buffer_mapped(&map_bh)) {
1443 		start_blk = next_pgofs;
1444 
1445 		if (blk_to_logical(inode, start_blk) < blk_to_logical(inode,
1446 					F2FS_I_SB(inode)->max_file_blocks))
1447 			goto prep_next;
1448 
1449 		flags |= FIEMAP_EXTENT_LAST;
1450 	}
1451 
1452 	if (size) {
1453 		if (f2fs_encrypted_inode(inode))
1454 			flags |= FIEMAP_EXTENT_DATA_ENCRYPTED;
1455 
1456 		ret = fiemap_fill_next_extent(fieinfo, logical,
1457 				phys, size, flags);
1458 	}
1459 
1460 	if (start_blk > last_blk || ret)
1461 		goto out;
1462 
1463 	logical = blk_to_logical(inode, start_blk);
1464 	phys = blk_to_logical(inode, map_bh.b_blocknr);
1465 	size = map_bh.b_size;
1466 	flags = 0;
1467 	if (buffer_unwritten(&map_bh))
1468 		flags = FIEMAP_EXTENT_UNWRITTEN;
1469 
1470 	start_blk += logical_to_blk(inode, size);
1471 
1472 prep_next:
1473 	cond_resched();
1474 	if (fatal_signal_pending(current))
1475 		ret = -EINTR;
1476 	else
1477 		goto next;
1478 out:
1479 	if (ret == 1)
1480 		ret = 0;
1481 
1482 	inode_unlock(inode);
1483 	return ret;
1484 }
1485 
1486 /*
1487  * This function was originally taken from fs/mpage.c, and customized for f2fs.
1488  * Major change was from block_size == page_size in f2fs by default.
1489  *
1490  * Note that the aops->readpages() function is ONLY used for read-ahead. If
1491  * this function ever deviates from doing just read-ahead, it should either
1492  * use ->readpage() or do the necessary surgery to decouple ->readpages()
1493  * from read-ahead.
1494  */
1495 static int f2fs_mpage_readpages(struct address_space *mapping,
1496 			struct list_head *pages, struct page *page,
1497 			unsigned nr_pages, bool is_readahead)
1498 {
1499 	struct bio *bio = NULL;
1500 	sector_t last_block_in_bio = 0;
1501 	struct inode *inode = mapping->host;
1502 	const unsigned blkbits = inode->i_blkbits;
1503 	const unsigned blocksize = 1 << blkbits;
1504 	sector_t block_in_file;
1505 	sector_t last_block;
1506 	sector_t last_block_in_file;
1507 	sector_t block_nr;
1508 	struct f2fs_map_blocks map;
1509 
1510 	map.m_pblk = 0;
1511 	map.m_lblk = 0;
1512 	map.m_len = 0;
1513 	map.m_flags = 0;
1514 	map.m_next_pgofs = NULL;
1515 	map.m_next_extent = NULL;
1516 	map.m_seg_type = NO_CHECK_TYPE;
1517 
1518 	for (; nr_pages; nr_pages--) {
1519 		if (pages) {
1520 			page = list_last_entry(pages, struct page, lru);
1521 
1522 			prefetchw(&page->flags);
1523 			list_del(&page->lru);
1524 			if (add_to_page_cache_lru(page, mapping,
1525 						  page->index,
1526 						  readahead_gfp_mask(mapping)))
1527 				goto next_page;
1528 		}
1529 
1530 		block_in_file = (sector_t)page->index;
1531 		last_block = block_in_file + nr_pages;
1532 		last_block_in_file = (i_size_read(inode) + blocksize - 1) >>
1533 								blkbits;
1534 		if (last_block > last_block_in_file)
1535 			last_block = last_block_in_file;
1536 
1537 		/*
1538 		 * Map blocks using the previous result first.
1539 		 */
1540 		if ((map.m_flags & F2FS_MAP_MAPPED) &&
1541 				block_in_file > map.m_lblk &&
1542 				block_in_file < (map.m_lblk + map.m_len))
1543 			goto got_it;
1544 
1545 		/*
1546 		 * Then do more f2fs_map_blocks() calls until we are
1547 		 * done with this page.
1548 		 */
1549 		map.m_flags = 0;
1550 
1551 		if (block_in_file < last_block) {
1552 			map.m_lblk = block_in_file;
1553 			map.m_len = last_block - block_in_file;
1554 
1555 			if (f2fs_map_blocks(inode, &map, 0,
1556 						F2FS_GET_BLOCK_DEFAULT))
1557 				goto set_error_page;
1558 		}
1559 got_it:
1560 		if ((map.m_flags & F2FS_MAP_MAPPED)) {
1561 			block_nr = map.m_pblk + block_in_file - map.m_lblk;
1562 			SetPageMappedToDisk(page);
1563 
1564 			if (!PageUptodate(page) && !cleancache_get_page(page)) {
1565 				SetPageUptodate(page);
1566 				goto confused;
1567 			}
1568 
1569 			if (!f2fs_is_valid_blkaddr(F2FS_I_SB(inode), block_nr,
1570 								DATA_GENERIC))
1571 				goto set_error_page;
1572 		} else {
1573 			zero_user_segment(page, 0, PAGE_SIZE);
1574 			if (!PageUptodate(page))
1575 				SetPageUptodate(page);
1576 			unlock_page(page);
1577 			goto next_page;
1578 		}
1579 
1580 		/*
1581 		 * This page will go to BIO.  Do we need to send this
1582 		 * BIO off first?
1583 		 */
1584 		if (bio && (last_block_in_bio != block_nr - 1 ||
1585 			!__same_bdev(F2FS_I_SB(inode), block_nr, bio))) {
1586 submit_and_realloc:
1587 			__submit_bio(F2FS_I_SB(inode), bio, DATA);
1588 			bio = NULL;
1589 		}
1590 		if (bio == NULL) {
1591 			bio = f2fs_grab_read_bio(inode, block_nr, nr_pages,
1592 					is_readahead ? REQ_RAHEAD : 0);
1593 			if (IS_ERR(bio)) {
1594 				bio = NULL;
1595 				goto set_error_page;
1596 			}
1597 		}
1598 
1599 		/*
1600 		 * If the page is under writeback, we need to wait for
1601 		 * its completion to see the correct decrypted data.
1602 		 */
1603 		f2fs_wait_on_block_writeback(inode, block_nr);
1604 
1605 		if (bio_add_page(bio, page, blocksize, 0) < blocksize)
1606 			goto submit_and_realloc;
1607 
1608 		inc_page_count(F2FS_I_SB(inode), F2FS_RD_DATA);
1609 		ClearPageError(page);
1610 		last_block_in_bio = block_nr;
1611 		goto next_page;
1612 set_error_page:
1613 		SetPageError(page);
1614 		zero_user_segment(page, 0, PAGE_SIZE);
1615 		unlock_page(page);
1616 		goto next_page;
1617 confused:
1618 		if (bio) {
1619 			__submit_bio(F2FS_I_SB(inode), bio, DATA);
1620 			bio = NULL;
1621 		}
1622 		unlock_page(page);
1623 next_page:
1624 		if (pages)
1625 			put_page(page);
1626 	}
1627 	BUG_ON(pages && !list_empty(pages));
1628 	if (bio)
1629 		__submit_bio(F2FS_I_SB(inode), bio, DATA);
1630 	return 0;
1631 }
1632 
1633 static int f2fs_read_data_page(struct file *file, struct page *page)
1634 {
1635 	struct inode *inode = page->mapping->host;
1636 	int ret = -EAGAIN;
1637 
1638 	trace_f2fs_readpage(page, DATA);
1639 
1640 	/* If the file has inline data, try to read it directly */
1641 	if (f2fs_has_inline_data(inode))
1642 		ret = f2fs_read_inline_data(inode, page);
1643 	if (ret == -EAGAIN)
1644 		ret = f2fs_mpage_readpages(page->mapping, NULL, page, 1, false);
1645 	return ret;
1646 }
1647 
1648 static int f2fs_read_data_pages(struct file *file,
1649 			struct address_space *mapping,
1650 			struct list_head *pages, unsigned nr_pages)
1651 {
1652 	struct inode *inode = mapping->host;
1653 	struct page *page = list_last_entry(pages, struct page, lru);
1654 
1655 	trace_f2fs_readpages(inode, page, nr_pages);
1656 
1657 	/* If the file has inline data, skip readpages */
1658 	if (f2fs_has_inline_data(inode))
1659 		return 0;
1660 
1661 	return f2fs_mpage_readpages(mapping, pages, NULL, nr_pages, true);
1662 }
1663 
1664 static int encrypt_one_page(struct f2fs_io_info *fio)
1665 {
1666 	struct inode *inode = fio->page->mapping->host;
1667 	struct page *mpage;
1668 	gfp_t gfp_flags = GFP_NOFS;
1669 
1670 	if (!f2fs_encrypted_file(inode))
1671 		return 0;
1672 
1673 	/* wait for GCed page writeback via META_MAPPING */
1674 	f2fs_wait_on_block_writeback(inode, fio->old_blkaddr);
1675 
1676 retry_encrypt:
1677 	fio->encrypted_page = fscrypt_encrypt_page(inode, fio->page,
1678 			PAGE_SIZE, 0, fio->page->index, gfp_flags);
1679 	if (IS_ERR(fio->encrypted_page)) {
1680 		/* flush pending IOs and wait for a while in the ENOMEM case */
1681 		if (PTR_ERR(fio->encrypted_page) == -ENOMEM) {
1682 			f2fs_flush_merged_writes(fio->sbi);
1683 			congestion_wait(BLK_RW_ASYNC, HZ/50);
1684 			gfp_flags |= __GFP_NOFAIL;
1685 			goto retry_encrypt;
1686 		}
1687 		return PTR_ERR(fio->encrypted_page);
1688 	}
1689 
1690 	mpage = find_lock_page(META_MAPPING(fio->sbi), fio->old_blkaddr);
1691 	if (mpage) {
1692 		if (PageUptodate(mpage))
1693 			memcpy(page_address(mpage),
1694 				page_address(fio->encrypted_page), PAGE_SIZE);
1695 		f2fs_put_page(mpage, 1);
1696 	}
1697 	return 0;
1698 }
1699 
1700 static inline bool check_inplace_update_policy(struct inode *inode,
1701 				struct f2fs_io_info *fio)
1702 {
1703 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1704 	unsigned int policy = SM_I(sbi)->ipu_policy;
1705 
1706 	if (policy & (0x1 << F2FS_IPU_FORCE))
1707 		return true;
1708 	if (policy & (0x1 << F2FS_IPU_SSR) && f2fs_need_SSR(sbi))
1709 		return true;
1710 	if (policy & (0x1 << F2FS_IPU_UTIL) &&
1711 			utilization(sbi) > SM_I(sbi)->min_ipu_util)
1712 		return true;
1713 	if (policy & (0x1 << F2FS_IPU_SSR_UTIL) && f2fs_need_SSR(sbi) &&
1714 			utilization(sbi) > SM_I(sbi)->min_ipu_util)
1715 		return true;
1716 
1717 	/*
1718 	 * IPU for rewrite async pages
1719 	 */
1720 	if (policy & (0x1 << F2FS_IPU_ASYNC) &&
1721 			fio && fio->op == REQ_OP_WRITE &&
1722 			!(fio->op_flags & REQ_SYNC) &&
1723 			!f2fs_encrypted_inode(inode))
1724 		return true;
1725 
1726 	/* this is only set during fdatasync */
1727 	if (policy & (0x1 << F2FS_IPU_FSYNC) &&
1728 			is_inode_flag_set(inode, FI_NEED_IPU))
1729 		return true;
1730 
1731 	if (unlikely(fio && is_sbi_flag_set(sbi, SBI_CP_DISABLED) &&
1732 			!f2fs_is_checkpointed_data(sbi, fio->old_blkaddr)))
1733 		return true;
1734 
1735 	return false;
1736 }
1737 
1738 bool f2fs_should_update_inplace(struct inode *inode, struct f2fs_io_info *fio)
1739 {
1740 	if (f2fs_is_pinned_file(inode))
1741 		return true;
1742 
1743 	/* if this is cold file, we should overwrite to avoid fragmentation */
1744 	if (file_is_cold(inode))
1745 		return true;
1746 
1747 	return check_inplace_update_policy(inode, fio);
1748 }
1749 
1750 bool f2fs_should_update_outplace(struct inode *inode, struct f2fs_io_info *fio)
1751 {
1752 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1753 
1754 	if (test_opt(sbi, LFS))
1755 		return true;
1756 	if (S_ISDIR(inode->i_mode))
1757 		return true;
1758 	if (f2fs_is_atomic_file(inode))
1759 		return true;
1760 	if (fio) {
1761 		if (is_cold_data(fio->page))
1762 			return true;
1763 		if (IS_ATOMIC_WRITTEN_PAGE(fio->page))
1764 			return true;
1765 		if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED) &&
1766 			f2fs_is_checkpointed_data(sbi, fio->old_blkaddr)))
1767 			return true;
1768 	}
1769 	return false;
1770 }
1771 
1772 static inline bool need_inplace_update(struct f2fs_io_info *fio)
1773 {
1774 	struct inode *inode = fio->page->mapping->host;
1775 
1776 	if (f2fs_should_update_outplace(inode, fio))
1777 		return false;
1778 
1779 	return f2fs_should_update_inplace(inode, fio);
1780 }
1781 
1782 int f2fs_do_write_data_page(struct f2fs_io_info *fio)
1783 {
1784 	struct page *page = fio->page;
1785 	struct inode *inode = page->mapping->host;
1786 	struct dnode_of_data dn;
1787 	struct extent_info ei = {0,0,0};
1788 	struct node_info ni;
1789 	bool ipu_force = false;
1790 	int err = 0;
1791 
1792 	set_new_dnode(&dn, inode, NULL, NULL, 0);
1793 	if (need_inplace_update(fio) &&
1794 			f2fs_lookup_extent_cache(inode, page->index, &ei)) {
1795 		fio->old_blkaddr = ei.blk + page->index - ei.fofs;
1796 
1797 		if (!f2fs_is_valid_blkaddr(fio->sbi, fio->old_blkaddr,
1798 							DATA_GENERIC))
1799 			return -EFAULT;
1800 
1801 		ipu_force = true;
1802 		fio->need_lock = LOCK_DONE;
1803 		goto got_it;
1804 	}
1805 
1806 	/* Deadlock due to between page->lock and f2fs_lock_op */
1807 	if (fio->need_lock == LOCK_REQ && !f2fs_trylock_op(fio->sbi))
1808 		return -EAGAIN;
1809 
1810 	err = f2fs_get_dnode_of_data(&dn, page->index, LOOKUP_NODE);
1811 	if (err)
1812 		goto out;
1813 
1814 	fio->old_blkaddr = dn.data_blkaddr;
1815 
1816 	/* This page is already truncated */
1817 	if (fio->old_blkaddr == NULL_ADDR) {
1818 		ClearPageUptodate(page);
1819 		clear_cold_data(page);
1820 		goto out_writepage;
1821 	}
1822 got_it:
1823 	if (__is_valid_data_blkaddr(fio->old_blkaddr) &&
1824 		!f2fs_is_valid_blkaddr(fio->sbi, fio->old_blkaddr,
1825 							DATA_GENERIC)) {
1826 		err = -EFAULT;
1827 		goto out_writepage;
1828 	}
1829 	/*
1830 	 * If current allocation needs SSR,
1831 	 * it had better in-place writes for updated data.
1832 	 */
1833 	if (ipu_force || (is_valid_data_blkaddr(fio->sbi, fio->old_blkaddr) &&
1834 					need_inplace_update(fio))) {
1835 		err = encrypt_one_page(fio);
1836 		if (err)
1837 			goto out_writepage;
1838 
1839 		set_page_writeback(page);
1840 		ClearPageError(page);
1841 		f2fs_put_dnode(&dn);
1842 		if (fio->need_lock == LOCK_REQ)
1843 			f2fs_unlock_op(fio->sbi);
1844 		err = f2fs_inplace_write_data(fio);
1845 		trace_f2fs_do_write_data_page(fio->page, IPU);
1846 		set_inode_flag(inode, FI_UPDATE_WRITE);
1847 		return err;
1848 	}
1849 
1850 	if (fio->need_lock == LOCK_RETRY) {
1851 		if (!f2fs_trylock_op(fio->sbi)) {
1852 			err = -EAGAIN;
1853 			goto out_writepage;
1854 		}
1855 		fio->need_lock = LOCK_REQ;
1856 	}
1857 
1858 	err = f2fs_get_node_info(fio->sbi, dn.nid, &ni);
1859 	if (err)
1860 		goto out_writepage;
1861 
1862 	fio->version = ni.version;
1863 
1864 	err = encrypt_one_page(fio);
1865 	if (err)
1866 		goto out_writepage;
1867 
1868 	set_page_writeback(page);
1869 	ClearPageError(page);
1870 
1871 	/* LFS mode write path */
1872 	f2fs_outplace_write_data(&dn, fio);
1873 	trace_f2fs_do_write_data_page(page, OPU);
1874 	set_inode_flag(inode, FI_APPEND_WRITE);
1875 	if (page->index == 0)
1876 		set_inode_flag(inode, FI_FIRST_BLOCK_WRITTEN);
1877 out_writepage:
1878 	f2fs_put_dnode(&dn);
1879 out:
1880 	if (fio->need_lock == LOCK_REQ)
1881 		f2fs_unlock_op(fio->sbi);
1882 	return err;
1883 }
1884 
1885 static int __write_data_page(struct page *page, bool *submitted,
1886 				struct writeback_control *wbc,
1887 				enum iostat_type io_type)
1888 {
1889 	struct inode *inode = page->mapping->host;
1890 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1891 	loff_t i_size = i_size_read(inode);
1892 	const pgoff_t end_index = ((unsigned long long) i_size)
1893 							>> PAGE_SHIFT;
1894 	loff_t psize = (page->index + 1) << PAGE_SHIFT;
1895 	unsigned offset = 0;
1896 	bool need_balance_fs = false;
1897 	int err = 0;
1898 	struct f2fs_io_info fio = {
1899 		.sbi = sbi,
1900 		.ino = inode->i_ino,
1901 		.type = DATA,
1902 		.op = REQ_OP_WRITE,
1903 		.op_flags = wbc_to_write_flags(wbc),
1904 		.old_blkaddr = NULL_ADDR,
1905 		.page = page,
1906 		.encrypted_page = NULL,
1907 		.submitted = false,
1908 		.need_lock = LOCK_RETRY,
1909 		.io_type = io_type,
1910 		.io_wbc = wbc,
1911 	};
1912 
1913 	trace_f2fs_writepage(page, DATA);
1914 
1915 	/* we should bypass data pages to proceed the kworkder jobs */
1916 	if (unlikely(f2fs_cp_error(sbi))) {
1917 		mapping_set_error(page->mapping, -EIO);
1918 		/*
1919 		 * don't drop any dirty dentry pages for keeping lastest
1920 		 * directory structure.
1921 		 */
1922 		if (S_ISDIR(inode->i_mode))
1923 			goto redirty_out;
1924 		goto out;
1925 	}
1926 
1927 	if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
1928 		goto redirty_out;
1929 
1930 	if (page->index < end_index)
1931 		goto write;
1932 
1933 	/*
1934 	 * If the offset is out-of-range of file size,
1935 	 * this page does not have to be written to disk.
1936 	 */
1937 	offset = i_size & (PAGE_SIZE - 1);
1938 	if ((page->index >= end_index + 1) || !offset)
1939 		goto out;
1940 
1941 	zero_user_segment(page, offset, PAGE_SIZE);
1942 write:
1943 	if (f2fs_is_drop_cache(inode))
1944 		goto out;
1945 	/* we should not write 0'th page having journal header */
1946 	if (f2fs_is_volatile_file(inode) && (!page->index ||
1947 			(!wbc->for_reclaim &&
1948 			f2fs_available_free_memory(sbi, BASE_CHECK))))
1949 		goto redirty_out;
1950 
1951 	/* Dentry blocks are controlled by checkpoint */
1952 	if (S_ISDIR(inode->i_mode)) {
1953 		fio.need_lock = LOCK_DONE;
1954 		err = f2fs_do_write_data_page(&fio);
1955 		goto done;
1956 	}
1957 
1958 	if (!wbc->for_reclaim)
1959 		need_balance_fs = true;
1960 	else if (has_not_enough_free_secs(sbi, 0, 0))
1961 		goto redirty_out;
1962 	else
1963 		set_inode_flag(inode, FI_HOT_DATA);
1964 
1965 	err = -EAGAIN;
1966 	if (f2fs_has_inline_data(inode)) {
1967 		err = f2fs_write_inline_data(inode, page);
1968 		if (!err)
1969 			goto out;
1970 	}
1971 
1972 	if (err == -EAGAIN) {
1973 		err = f2fs_do_write_data_page(&fio);
1974 		if (err == -EAGAIN) {
1975 			fio.need_lock = LOCK_REQ;
1976 			err = f2fs_do_write_data_page(&fio);
1977 		}
1978 	}
1979 
1980 	if (err) {
1981 		file_set_keep_isize(inode);
1982 	} else {
1983 		down_write(&F2FS_I(inode)->i_sem);
1984 		if (F2FS_I(inode)->last_disk_size < psize)
1985 			F2FS_I(inode)->last_disk_size = psize;
1986 		up_write(&F2FS_I(inode)->i_sem);
1987 	}
1988 
1989 done:
1990 	if (err && err != -ENOENT)
1991 		goto redirty_out;
1992 
1993 out:
1994 	inode_dec_dirty_pages(inode);
1995 	if (err) {
1996 		ClearPageUptodate(page);
1997 		clear_cold_data(page);
1998 	}
1999 
2000 	if (wbc->for_reclaim) {
2001 		f2fs_submit_merged_write_cond(sbi, NULL, page, 0, DATA);
2002 		clear_inode_flag(inode, FI_HOT_DATA);
2003 		f2fs_remove_dirty_inode(inode);
2004 		submitted = NULL;
2005 	}
2006 
2007 	unlock_page(page);
2008 	if (!S_ISDIR(inode->i_mode))
2009 		f2fs_balance_fs(sbi, need_balance_fs);
2010 
2011 	if (unlikely(f2fs_cp_error(sbi))) {
2012 		f2fs_submit_merged_write(sbi, DATA);
2013 		submitted = NULL;
2014 	}
2015 
2016 	if (submitted)
2017 		*submitted = fio.submitted;
2018 
2019 	return 0;
2020 
2021 redirty_out:
2022 	redirty_page_for_writepage(wbc, page);
2023 	/*
2024 	 * pageout() in MM traslates EAGAIN, so calls handle_write_error()
2025 	 * -> mapping_set_error() -> set_bit(AS_EIO, ...).
2026 	 * file_write_and_wait_range() will see EIO error, which is critical
2027 	 * to return value of fsync() followed by atomic_write failure to user.
2028 	 */
2029 	if (!err || wbc->for_reclaim)
2030 		return AOP_WRITEPAGE_ACTIVATE;
2031 	unlock_page(page);
2032 	return err;
2033 }
2034 
2035 static int f2fs_write_data_page(struct page *page,
2036 					struct writeback_control *wbc)
2037 {
2038 	return __write_data_page(page, NULL, wbc, FS_DATA_IO);
2039 }
2040 
2041 /*
2042  * This function was copied from write_cche_pages from mm/page-writeback.c.
2043  * The major change is making write step of cold data page separately from
2044  * warm/hot data page.
2045  */
2046 static int f2fs_write_cache_pages(struct address_space *mapping,
2047 					struct writeback_control *wbc,
2048 					enum iostat_type io_type)
2049 {
2050 	int ret = 0;
2051 	int done = 0;
2052 	struct pagevec pvec;
2053 	struct f2fs_sb_info *sbi = F2FS_M_SB(mapping);
2054 	int nr_pages;
2055 	pgoff_t uninitialized_var(writeback_index);
2056 	pgoff_t index;
2057 	pgoff_t end;		/* Inclusive */
2058 	pgoff_t done_index;
2059 	int cycled;
2060 	int range_whole = 0;
2061 	int tag;
2062 	int nwritten = 0;
2063 
2064 	pagevec_init(&pvec);
2065 
2066 	if (get_dirty_pages(mapping->host) <=
2067 				SM_I(F2FS_M_SB(mapping))->min_hot_blocks)
2068 		set_inode_flag(mapping->host, FI_HOT_DATA);
2069 	else
2070 		clear_inode_flag(mapping->host, FI_HOT_DATA);
2071 
2072 	if (wbc->range_cyclic) {
2073 		writeback_index = mapping->writeback_index; /* prev offset */
2074 		index = writeback_index;
2075 		if (index == 0)
2076 			cycled = 1;
2077 		else
2078 			cycled = 0;
2079 		end = -1;
2080 	} else {
2081 		index = wbc->range_start >> PAGE_SHIFT;
2082 		end = wbc->range_end >> PAGE_SHIFT;
2083 		if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
2084 			range_whole = 1;
2085 		cycled = 1; /* ignore range_cyclic tests */
2086 	}
2087 	if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
2088 		tag = PAGECACHE_TAG_TOWRITE;
2089 	else
2090 		tag = PAGECACHE_TAG_DIRTY;
2091 retry:
2092 	if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
2093 		tag_pages_for_writeback(mapping, index, end);
2094 	done_index = index;
2095 	while (!done && (index <= end)) {
2096 		int i;
2097 
2098 		nr_pages = pagevec_lookup_range_tag(&pvec, mapping, &index, end,
2099 				tag);
2100 		if (nr_pages == 0)
2101 			break;
2102 
2103 		for (i = 0; i < nr_pages; i++) {
2104 			struct page *page = pvec.pages[i];
2105 			bool submitted = false;
2106 
2107 			/* give a priority to WB_SYNC threads */
2108 			if (atomic_read(&sbi->wb_sync_req[DATA]) &&
2109 					wbc->sync_mode == WB_SYNC_NONE) {
2110 				done = 1;
2111 				break;
2112 			}
2113 
2114 			done_index = page->index;
2115 retry_write:
2116 			lock_page(page);
2117 
2118 			if (unlikely(page->mapping != mapping)) {
2119 continue_unlock:
2120 				unlock_page(page);
2121 				continue;
2122 			}
2123 
2124 			if (!PageDirty(page)) {
2125 				/* someone wrote it for us */
2126 				goto continue_unlock;
2127 			}
2128 
2129 			if (PageWriteback(page)) {
2130 				if (wbc->sync_mode != WB_SYNC_NONE)
2131 					f2fs_wait_on_page_writeback(page,
2132 								DATA, true);
2133 				else
2134 					goto continue_unlock;
2135 			}
2136 
2137 			BUG_ON(PageWriteback(page));
2138 			if (!clear_page_dirty_for_io(page))
2139 				goto continue_unlock;
2140 
2141 			ret = __write_data_page(page, &submitted, wbc, io_type);
2142 			if (unlikely(ret)) {
2143 				/*
2144 				 * keep nr_to_write, since vfs uses this to
2145 				 * get # of written pages.
2146 				 */
2147 				if (ret == AOP_WRITEPAGE_ACTIVATE) {
2148 					unlock_page(page);
2149 					ret = 0;
2150 					continue;
2151 				} else if (ret == -EAGAIN) {
2152 					ret = 0;
2153 					if (wbc->sync_mode == WB_SYNC_ALL) {
2154 						cond_resched();
2155 						congestion_wait(BLK_RW_ASYNC,
2156 									HZ/50);
2157 						goto retry_write;
2158 					}
2159 					continue;
2160 				}
2161 				done_index = page->index + 1;
2162 				done = 1;
2163 				break;
2164 			} else if (submitted) {
2165 				nwritten++;
2166 			}
2167 
2168 			if (--wbc->nr_to_write <= 0 &&
2169 					wbc->sync_mode == WB_SYNC_NONE) {
2170 				done = 1;
2171 				break;
2172 			}
2173 		}
2174 		pagevec_release(&pvec);
2175 		cond_resched();
2176 	}
2177 
2178 	if (!cycled && !done) {
2179 		cycled = 1;
2180 		index = 0;
2181 		end = writeback_index - 1;
2182 		goto retry;
2183 	}
2184 	if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
2185 		mapping->writeback_index = done_index;
2186 
2187 	if (nwritten)
2188 		f2fs_submit_merged_write_cond(F2FS_M_SB(mapping), mapping->host,
2189 								NULL, 0, DATA);
2190 
2191 	return ret;
2192 }
2193 
2194 static inline bool __should_serialize_io(struct inode *inode,
2195 					struct writeback_control *wbc)
2196 {
2197 	if (!S_ISREG(inode->i_mode))
2198 		return false;
2199 	if (wbc->sync_mode != WB_SYNC_ALL)
2200 		return true;
2201 	if (get_dirty_pages(inode) >= SM_I(F2FS_I_SB(inode))->min_seq_blocks)
2202 		return true;
2203 	return false;
2204 }
2205 
2206 static int __f2fs_write_data_pages(struct address_space *mapping,
2207 						struct writeback_control *wbc,
2208 						enum iostat_type io_type)
2209 {
2210 	struct inode *inode = mapping->host;
2211 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
2212 	struct blk_plug plug;
2213 	int ret;
2214 	bool locked = false;
2215 
2216 	/* deal with chardevs and other special file */
2217 	if (!mapping->a_ops->writepage)
2218 		return 0;
2219 
2220 	/* skip writing if there is no dirty page in this inode */
2221 	if (!get_dirty_pages(inode) && wbc->sync_mode == WB_SYNC_NONE)
2222 		return 0;
2223 
2224 	/* during POR, we don't need to trigger writepage at all. */
2225 	if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
2226 		goto skip_write;
2227 
2228 	if (S_ISDIR(inode->i_mode) && wbc->sync_mode == WB_SYNC_NONE &&
2229 			get_dirty_pages(inode) < nr_pages_to_skip(sbi, DATA) &&
2230 			f2fs_available_free_memory(sbi, DIRTY_DENTS))
2231 		goto skip_write;
2232 
2233 	/* skip writing during file defragment */
2234 	if (is_inode_flag_set(inode, FI_DO_DEFRAG))
2235 		goto skip_write;
2236 
2237 	trace_f2fs_writepages(mapping->host, wbc, DATA);
2238 
2239 	/* to avoid spliting IOs due to mixed WB_SYNC_ALL and WB_SYNC_NONE */
2240 	if (wbc->sync_mode == WB_SYNC_ALL)
2241 		atomic_inc(&sbi->wb_sync_req[DATA]);
2242 	else if (atomic_read(&sbi->wb_sync_req[DATA]))
2243 		goto skip_write;
2244 
2245 	if (__should_serialize_io(inode, wbc)) {
2246 		mutex_lock(&sbi->writepages);
2247 		locked = true;
2248 	}
2249 
2250 	blk_start_plug(&plug);
2251 	ret = f2fs_write_cache_pages(mapping, wbc, io_type);
2252 	blk_finish_plug(&plug);
2253 
2254 	if (locked)
2255 		mutex_unlock(&sbi->writepages);
2256 
2257 	if (wbc->sync_mode == WB_SYNC_ALL)
2258 		atomic_dec(&sbi->wb_sync_req[DATA]);
2259 	/*
2260 	 * if some pages were truncated, we cannot guarantee its mapping->host
2261 	 * to detect pending bios.
2262 	 */
2263 
2264 	f2fs_remove_dirty_inode(inode);
2265 	return ret;
2266 
2267 skip_write:
2268 	wbc->pages_skipped += get_dirty_pages(inode);
2269 	trace_f2fs_writepages(mapping->host, wbc, DATA);
2270 	return 0;
2271 }
2272 
2273 static int f2fs_write_data_pages(struct address_space *mapping,
2274 			    struct writeback_control *wbc)
2275 {
2276 	struct inode *inode = mapping->host;
2277 
2278 	return __f2fs_write_data_pages(mapping, wbc,
2279 			F2FS_I(inode)->cp_task == current ?
2280 			FS_CP_DATA_IO : FS_DATA_IO);
2281 }
2282 
2283 static void f2fs_write_failed(struct address_space *mapping, loff_t to)
2284 {
2285 	struct inode *inode = mapping->host;
2286 	loff_t i_size = i_size_read(inode);
2287 
2288 	if (to > i_size) {
2289 		down_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
2290 		down_write(&F2FS_I(inode)->i_mmap_sem);
2291 
2292 		truncate_pagecache(inode, i_size);
2293 		f2fs_truncate_blocks(inode, i_size, true);
2294 
2295 		up_write(&F2FS_I(inode)->i_mmap_sem);
2296 		up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
2297 	}
2298 }
2299 
2300 static int prepare_write_begin(struct f2fs_sb_info *sbi,
2301 			struct page *page, loff_t pos, unsigned len,
2302 			block_t *blk_addr, bool *node_changed)
2303 {
2304 	struct inode *inode = page->mapping->host;
2305 	pgoff_t index = page->index;
2306 	struct dnode_of_data dn;
2307 	struct page *ipage;
2308 	bool locked = false;
2309 	struct extent_info ei = {0,0,0};
2310 	int err = 0;
2311 
2312 	/*
2313 	 * we already allocated all the blocks, so we don't need to get
2314 	 * the block addresses when there is no need to fill the page.
2315 	 */
2316 	if (!f2fs_has_inline_data(inode) && len == PAGE_SIZE &&
2317 			!is_inode_flag_set(inode, FI_NO_PREALLOC))
2318 		return 0;
2319 
2320 	if (f2fs_has_inline_data(inode) ||
2321 			(pos & PAGE_MASK) >= i_size_read(inode)) {
2322 		__do_map_lock(sbi, F2FS_GET_BLOCK_PRE_AIO, true);
2323 		locked = true;
2324 	}
2325 restart:
2326 	/* check inline_data */
2327 	ipage = f2fs_get_node_page(sbi, inode->i_ino);
2328 	if (IS_ERR(ipage)) {
2329 		err = PTR_ERR(ipage);
2330 		goto unlock_out;
2331 	}
2332 
2333 	set_new_dnode(&dn, inode, ipage, ipage, 0);
2334 
2335 	if (f2fs_has_inline_data(inode)) {
2336 		if (pos + len <= MAX_INLINE_DATA(inode)) {
2337 			f2fs_do_read_inline_data(page, ipage);
2338 			set_inode_flag(inode, FI_DATA_EXIST);
2339 			if (inode->i_nlink)
2340 				set_inline_node(ipage);
2341 		} else {
2342 			err = f2fs_convert_inline_page(&dn, page);
2343 			if (err)
2344 				goto out;
2345 			if (dn.data_blkaddr == NULL_ADDR)
2346 				err = f2fs_get_block(&dn, index);
2347 		}
2348 	} else if (locked) {
2349 		err = f2fs_get_block(&dn, index);
2350 	} else {
2351 		if (f2fs_lookup_extent_cache(inode, index, &ei)) {
2352 			dn.data_blkaddr = ei.blk + index - ei.fofs;
2353 		} else {
2354 			/* hole case */
2355 			err = f2fs_get_dnode_of_data(&dn, index, LOOKUP_NODE);
2356 			if (err || dn.data_blkaddr == NULL_ADDR) {
2357 				f2fs_put_dnode(&dn);
2358 				__do_map_lock(sbi, F2FS_GET_BLOCK_PRE_AIO,
2359 								true);
2360 				locked = true;
2361 				goto restart;
2362 			}
2363 		}
2364 	}
2365 
2366 	/* convert_inline_page can make node_changed */
2367 	*blk_addr = dn.data_blkaddr;
2368 	*node_changed = dn.node_changed;
2369 out:
2370 	f2fs_put_dnode(&dn);
2371 unlock_out:
2372 	if (locked)
2373 		__do_map_lock(sbi, F2FS_GET_BLOCK_PRE_AIO, false);
2374 	return err;
2375 }
2376 
2377 static int f2fs_write_begin(struct file *file, struct address_space *mapping,
2378 		loff_t pos, unsigned len, unsigned flags,
2379 		struct page **pagep, void **fsdata)
2380 {
2381 	struct inode *inode = mapping->host;
2382 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
2383 	struct page *page = NULL;
2384 	pgoff_t index = ((unsigned long long) pos) >> PAGE_SHIFT;
2385 	bool need_balance = false, drop_atomic = false;
2386 	block_t blkaddr = NULL_ADDR;
2387 	int err = 0;
2388 
2389 	trace_f2fs_write_begin(inode, pos, len, flags);
2390 
2391 	err = f2fs_is_checkpoint_ready(sbi);
2392 	if (err)
2393 		goto fail;
2394 
2395 	if ((f2fs_is_atomic_file(inode) &&
2396 			!f2fs_available_free_memory(sbi, INMEM_PAGES)) ||
2397 			is_inode_flag_set(inode, FI_ATOMIC_REVOKE_REQUEST)) {
2398 		err = -ENOMEM;
2399 		drop_atomic = true;
2400 		goto fail;
2401 	}
2402 
2403 	/*
2404 	 * We should check this at this moment to avoid deadlock on inode page
2405 	 * and #0 page. The locking rule for inline_data conversion should be:
2406 	 * lock_page(page #0) -> lock_page(inode_page)
2407 	 */
2408 	if (index != 0) {
2409 		err = f2fs_convert_inline_inode(inode);
2410 		if (err)
2411 			goto fail;
2412 	}
2413 repeat:
2414 	/*
2415 	 * Do not use grab_cache_page_write_begin() to avoid deadlock due to
2416 	 * wait_for_stable_page. Will wait that below with our IO control.
2417 	 */
2418 	page = f2fs_pagecache_get_page(mapping, index,
2419 				FGP_LOCK | FGP_WRITE | FGP_CREAT, GFP_NOFS);
2420 	if (!page) {
2421 		err = -ENOMEM;
2422 		goto fail;
2423 	}
2424 
2425 	*pagep = page;
2426 
2427 	err = prepare_write_begin(sbi, page, pos, len,
2428 					&blkaddr, &need_balance);
2429 	if (err)
2430 		goto fail;
2431 
2432 	if (need_balance && has_not_enough_free_secs(sbi, 0, 0)) {
2433 		unlock_page(page);
2434 		f2fs_balance_fs(sbi, true);
2435 		lock_page(page);
2436 		if (page->mapping != mapping) {
2437 			/* The page got truncated from under us */
2438 			f2fs_put_page(page, 1);
2439 			goto repeat;
2440 		}
2441 	}
2442 
2443 	f2fs_wait_on_page_writeback(page, DATA, false);
2444 
2445 	if (len == PAGE_SIZE || PageUptodate(page))
2446 		return 0;
2447 
2448 	if (!(pos & (PAGE_SIZE - 1)) && (pos + len) >= i_size_read(inode)) {
2449 		zero_user_segment(page, len, PAGE_SIZE);
2450 		return 0;
2451 	}
2452 
2453 	if (blkaddr == NEW_ADDR) {
2454 		zero_user_segment(page, 0, PAGE_SIZE);
2455 		SetPageUptodate(page);
2456 	} else {
2457 		err = f2fs_submit_page_read(inode, page, blkaddr);
2458 		if (err)
2459 			goto fail;
2460 
2461 		lock_page(page);
2462 		if (unlikely(page->mapping != mapping)) {
2463 			f2fs_put_page(page, 1);
2464 			goto repeat;
2465 		}
2466 		if (unlikely(!PageUptodate(page))) {
2467 			err = -EIO;
2468 			goto fail;
2469 		}
2470 	}
2471 	return 0;
2472 
2473 fail:
2474 	f2fs_put_page(page, 1);
2475 	f2fs_write_failed(mapping, pos + len);
2476 	if (drop_atomic)
2477 		f2fs_drop_inmem_pages_all(sbi, false);
2478 	return err;
2479 }
2480 
2481 static int f2fs_write_end(struct file *file,
2482 			struct address_space *mapping,
2483 			loff_t pos, unsigned len, unsigned copied,
2484 			struct page *page, void *fsdata)
2485 {
2486 	struct inode *inode = page->mapping->host;
2487 
2488 	trace_f2fs_write_end(inode, pos, len, copied);
2489 
2490 	/*
2491 	 * This should be come from len == PAGE_SIZE, and we expect copied
2492 	 * should be PAGE_SIZE. Otherwise, we treat it with zero copied and
2493 	 * let generic_perform_write() try to copy data again through copied=0.
2494 	 */
2495 	if (!PageUptodate(page)) {
2496 		if (unlikely(copied != len))
2497 			copied = 0;
2498 		else
2499 			SetPageUptodate(page);
2500 	}
2501 	if (!copied)
2502 		goto unlock_out;
2503 
2504 	set_page_dirty(page);
2505 
2506 	if (pos + copied > i_size_read(inode))
2507 		f2fs_i_size_write(inode, pos + copied);
2508 unlock_out:
2509 	f2fs_put_page(page, 1);
2510 	f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
2511 	return copied;
2512 }
2513 
2514 static int check_direct_IO(struct inode *inode, struct iov_iter *iter,
2515 			   loff_t offset)
2516 {
2517 	unsigned i_blkbits = READ_ONCE(inode->i_blkbits);
2518 	unsigned blkbits = i_blkbits;
2519 	unsigned blocksize_mask = (1 << blkbits) - 1;
2520 	unsigned long align = offset | iov_iter_alignment(iter);
2521 	struct block_device *bdev = inode->i_sb->s_bdev;
2522 
2523 	if (align & blocksize_mask) {
2524 		if (bdev)
2525 			blkbits = blksize_bits(bdev_logical_block_size(bdev));
2526 		blocksize_mask = (1 << blkbits) - 1;
2527 		if (align & blocksize_mask)
2528 			return -EINVAL;
2529 		return 1;
2530 	}
2531 	return 0;
2532 }
2533 
2534 static ssize_t f2fs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
2535 {
2536 	struct address_space *mapping = iocb->ki_filp->f_mapping;
2537 	struct inode *inode = mapping->host;
2538 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
2539 	struct f2fs_inode_info *fi = F2FS_I(inode);
2540 	size_t count = iov_iter_count(iter);
2541 	loff_t offset = iocb->ki_pos;
2542 	int rw = iov_iter_rw(iter);
2543 	int err;
2544 	enum rw_hint hint = iocb->ki_hint;
2545 	int whint_mode = F2FS_OPTION(sbi).whint_mode;
2546 	bool do_opu;
2547 
2548 	err = check_direct_IO(inode, iter, offset);
2549 	if (err)
2550 		return err < 0 ? err : 0;
2551 
2552 	if (f2fs_force_buffered_io(inode, iocb, iter))
2553 		return 0;
2554 
2555 	do_opu = allow_outplace_dio(inode, iocb, iter);
2556 
2557 	trace_f2fs_direct_IO_enter(inode, offset, count, rw);
2558 
2559 	if (rw == WRITE && whint_mode == WHINT_MODE_OFF)
2560 		iocb->ki_hint = WRITE_LIFE_NOT_SET;
2561 
2562 	if (iocb->ki_flags & IOCB_NOWAIT) {
2563 		if (!down_read_trylock(&fi->i_gc_rwsem[rw])) {
2564 			iocb->ki_hint = hint;
2565 			err = -EAGAIN;
2566 			goto out;
2567 		}
2568 		if (do_opu && !down_read_trylock(&fi->i_gc_rwsem[READ])) {
2569 			up_read(&fi->i_gc_rwsem[rw]);
2570 			iocb->ki_hint = hint;
2571 			err = -EAGAIN;
2572 			goto out;
2573 		}
2574 	} else {
2575 		down_read(&fi->i_gc_rwsem[rw]);
2576 		if (do_opu)
2577 			down_read(&fi->i_gc_rwsem[READ]);
2578 	}
2579 
2580 	err = blockdev_direct_IO(iocb, inode, iter, get_data_block_dio);
2581 
2582 	if (do_opu)
2583 		up_read(&fi->i_gc_rwsem[READ]);
2584 
2585 	up_read(&fi->i_gc_rwsem[rw]);
2586 
2587 	if (rw == WRITE) {
2588 		if (whint_mode == WHINT_MODE_OFF)
2589 			iocb->ki_hint = hint;
2590 		if (err > 0) {
2591 			f2fs_update_iostat(F2FS_I_SB(inode), APP_DIRECT_IO,
2592 									err);
2593 			if (!do_opu)
2594 				set_inode_flag(inode, FI_UPDATE_WRITE);
2595 		} else if (err < 0) {
2596 			f2fs_write_failed(mapping, offset + count);
2597 		}
2598 	}
2599 
2600 out:
2601 	trace_f2fs_direct_IO_exit(inode, offset, count, rw, err);
2602 
2603 	return err;
2604 }
2605 
2606 void f2fs_invalidate_page(struct page *page, unsigned int offset,
2607 							unsigned int length)
2608 {
2609 	struct inode *inode = page->mapping->host;
2610 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
2611 
2612 	if (inode->i_ino >= F2FS_ROOT_INO(sbi) &&
2613 		(offset % PAGE_SIZE || length != PAGE_SIZE))
2614 		return;
2615 
2616 	if (PageDirty(page)) {
2617 		if (inode->i_ino == F2FS_META_INO(sbi)) {
2618 			dec_page_count(sbi, F2FS_DIRTY_META);
2619 		} else if (inode->i_ino == F2FS_NODE_INO(sbi)) {
2620 			dec_page_count(sbi, F2FS_DIRTY_NODES);
2621 		} else {
2622 			inode_dec_dirty_pages(inode);
2623 			f2fs_remove_dirty_inode(inode);
2624 		}
2625 	}
2626 
2627 	clear_cold_data(page);
2628 
2629 	/* This is atomic written page, keep Private */
2630 	if (IS_ATOMIC_WRITTEN_PAGE(page))
2631 		return f2fs_drop_inmem_page(inode, page);
2632 
2633 	set_page_private(page, 0);
2634 	ClearPagePrivate(page);
2635 }
2636 
2637 int f2fs_release_page(struct page *page, gfp_t wait)
2638 {
2639 	/* If this is dirty page, keep PagePrivate */
2640 	if (PageDirty(page))
2641 		return 0;
2642 
2643 	/* This is atomic written page, keep Private */
2644 	if (IS_ATOMIC_WRITTEN_PAGE(page))
2645 		return 0;
2646 
2647 	clear_cold_data(page);
2648 	set_page_private(page, 0);
2649 	ClearPagePrivate(page);
2650 	return 1;
2651 }
2652 
2653 static int f2fs_set_data_page_dirty(struct page *page)
2654 {
2655 	struct address_space *mapping = page->mapping;
2656 	struct inode *inode = mapping->host;
2657 
2658 	trace_f2fs_set_page_dirty(page, DATA);
2659 
2660 	if (!PageUptodate(page))
2661 		SetPageUptodate(page);
2662 
2663 	if (f2fs_is_atomic_file(inode) && !f2fs_is_commit_atomic_write(inode)) {
2664 		if (!IS_ATOMIC_WRITTEN_PAGE(page)) {
2665 			f2fs_register_inmem_page(inode, page);
2666 			return 1;
2667 		}
2668 		/*
2669 		 * Previously, this page has been registered, we just
2670 		 * return here.
2671 		 */
2672 		return 0;
2673 	}
2674 
2675 	if (!PageDirty(page)) {
2676 		__set_page_dirty_nobuffers(page);
2677 		f2fs_update_dirty_page(inode, page);
2678 		return 1;
2679 	}
2680 	return 0;
2681 }
2682 
2683 static sector_t f2fs_bmap(struct address_space *mapping, sector_t block)
2684 {
2685 	struct inode *inode = mapping->host;
2686 
2687 	if (f2fs_has_inline_data(inode))
2688 		return 0;
2689 
2690 	/* make sure allocating whole blocks */
2691 	if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
2692 		filemap_write_and_wait(mapping);
2693 
2694 	return generic_block_bmap(mapping, block, get_data_block_bmap);
2695 }
2696 
2697 #ifdef CONFIG_MIGRATION
2698 #include <linux/migrate.h>
2699 
2700 int f2fs_migrate_page(struct address_space *mapping,
2701 		struct page *newpage, struct page *page, enum migrate_mode mode)
2702 {
2703 	int rc, extra_count;
2704 	struct f2fs_inode_info *fi = F2FS_I(mapping->host);
2705 	bool atomic_written = IS_ATOMIC_WRITTEN_PAGE(page);
2706 
2707 	BUG_ON(PageWriteback(page));
2708 
2709 	/* migrating an atomic written page is safe with the inmem_lock hold */
2710 	if (atomic_written) {
2711 		if (mode != MIGRATE_SYNC)
2712 			return -EBUSY;
2713 		if (!mutex_trylock(&fi->inmem_lock))
2714 			return -EAGAIN;
2715 	}
2716 
2717 	/*
2718 	 * A reference is expected if PagePrivate set when move mapping,
2719 	 * however F2FS breaks this for maintaining dirty page counts when
2720 	 * truncating pages. So here adjusting the 'extra_count' make it work.
2721 	 */
2722 	extra_count = (atomic_written ? 1 : 0) - page_has_private(page);
2723 	rc = migrate_page_move_mapping(mapping, newpage,
2724 				page, NULL, mode, extra_count);
2725 	if (rc != MIGRATEPAGE_SUCCESS) {
2726 		if (atomic_written)
2727 			mutex_unlock(&fi->inmem_lock);
2728 		return rc;
2729 	}
2730 
2731 	if (atomic_written) {
2732 		struct inmem_pages *cur;
2733 		list_for_each_entry(cur, &fi->inmem_pages, list)
2734 			if (cur->page == page) {
2735 				cur->page = newpage;
2736 				break;
2737 			}
2738 		mutex_unlock(&fi->inmem_lock);
2739 		put_page(page);
2740 		get_page(newpage);
2741 	}
2742 
2743 	if (PagePrivate(page))
2744 		SetPagePrivate(newpage);
2745 	set_page_private(newpage, page_private(page));
2746 
2747 	if (mode != MIGRATE_SYNC_NO_COPY)
2748 		migrate_page_copy(newpage, page);
2749 	else
2750 		migrate_page_states(newpage, page);
2751 
2752 	return MIGRATEPAGE_SUCCESS;
2753 }
2754 #endif
2755 
2756 const struct address_space_operations f2fs_dblock_aops = {
2757 	.readpage	= f2fs_read_data_page,
2758 	.readpages	= f2fs_read_data_pages,
2759 	.writepage	= f2fs_write_data_page,
2760 	.writepages	= f2fs_write_data_pages,
2761 	.write_begin	= f2fs_write_begin,
2762 	.write_end	= f2fs_write_end,
2763 	.set_page_dirty	= f2fs_set_data_page_dirty,
2764 	.invalidatepage	= f2fs_invalidate_page,
2765 	.releasepage	= f2fs_release_page,
2766 	.direct_IO	= f2fs_direct_IO,
2767 	.bmap		= f2fs_bmap,
2768 #ifdef CONFIG_MIGRATION
2769 	.migratepage    = f2fs_migrate_page,
2770 #endif
2771 };
2772 
2773 void f2fs_clear_radix_tree_dirty_tag(struct page *page)
2774 {
2775 	struct address_space *mapping = page_mapping(page);
2776 	unsigned long flags;
2777 
2778 	xa_lock_irqsave(&mapping->i_pages, flags);
2779 	radix_tree_tag_clear(&mapping->i_pages, page_index(page),
2780 						PAGECACHE_TAG_DIRTY);
2781 	xa_unlock_irqrestore(&mapping->i_pages, flags);
2782 }
2783 
2784 int __init f2fs_init_post_read_processing(void)
2785 {
2786 	bio_post_read_ctx_cache = KMEM_CACHE(bio_post_read_ctx, 0);
2787 	if (!bio_post_read_ctx_cache)
2788 		goto fail;
2789 	bio_post_read_ctx_pool =
2790 		mempool_create_slab_pool(NUM_PREALLOC_POST_READ_CTXS,
2791 					 bio_post_read_ctx_cache);
2792 	if (!bio_post_read_ctx_pool)
2793 		goto fail_free_cache;
2794 	return 0;
2795 
2796 fail_free_cache:
2797 	kmem_cache_destroy(bio_post_read_ctx_cache);
2798 fail:
2799 	return -ENOMEM;
2800 }
2801 
2802 void __exit f2fs_destroy_post_read_processing(void)
2803 {
2804 	mempool_destroy(bio_post_read_ctx_pool);
2805 	kmem_cache_destroy(bio_post_read_ctx_cache);
2806 }
2807