xref: /openbmc/linux/fs/f2fs/data.c (revision 80483c3a)
1 /*
2  * fs/f2fs/data.c
3  *
4  * Copyright (c) 2012 Samsung Electronics Co., Ltd.
5  *             http://www.samsung.com/
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  */
11 #include <linux/fs.h>
12 #include <linux/f2fs_fs.h>
13 #include <linux/buffer_head.h>
14 #include <linux/mpage.h>
15 #include <linux/writeback.h>
16 #include <linux/backing-dev.h>
17 #include <linux/pagevec.h>
18 #include <linux/blkdev.h>
19 #include <linux/bio.h>
20 #include <linux/prefetch.h>
21 #include <linux/uio.h>
22 #include <linux/mm.h>
23 #include <linux/memcontrol.h>
24 #include <linux/cleancache.h>
25 
26 #include "f2fs.h"
27 #include "node.h"
28 #include "segment.h"
29 #include "trace.h"
30 #include <trace/events/f2fs.h>
31 
32 static void f2fs_read_end_io(struct bio *bio)
33 {
34 	struct bio_vec *bvec;
35 	int i;
36 
37 	if (f2fs_bio_encrypted(bio)) {
38 		if (bio->bi_error) {
39 			fscrypt_release_ctx(bio->bi_private);
40 		} else {
41 			fscrypt_decrypt_bio_pages(bio->bi_private, bio);
42 			return;
43 		}
44 	}
45 
46 	bio_for_each_segment_all(bvec, bio, i) {
47 		struct page *page = bvec->bv_page;
48 
49 		if (!bio->bi_error) {
50 			if (!PageUptodate(page))
51 				SetPageUptodate(page);
52 		} else {
53 			ClearPageUptodate(page);
54 			SetPageError(page);
55 		}
56 		unlock_page(page);
57 	}
58 	bio_put(bio);
59 }
60 
61 static void f2fs_write_end_io(struct bio *bio)
62 {
63 	struct f2fs_sb_info *sbi = bio->bi_private;
64 	struct bio_vec *bvec;
65 	int i;
66 
67 	bio_for_each_segment_all(bvec, bio, i) {
68 		struct page *page = bvec->bv_page;
69 
70 		fscrypt_pullback_bio_page(&page, true);
71 
72 		if (unlikely(bio->bi_error)) {
73 			set_bit(AS_EIO, &page->mapping->flags);
74 			f2fs_stop_checkpoint(sbi, true);
75 		}
76 		end_page_writeback(page);
77 	}
78 	if (atomic_dec_and_test(&sbi->nr_wb_bios) &&
79 				wq_has_sleeper(&sbi->cp_wait))
80 		wake_up(&sbi->cp_wait);
81 
82 	bio_put(bio);
83 }
84 
85 /*
86  * Low-level block read/write IO operations.
87  */
88 static struct bio *__bio_alloc(struct f2fs_sb_info *sbi, block_t blk_addr,
89 				int npages, bool is_read)
90 {
91 	struct bio *bio;
92 
93 	bio = f2fs_bio_alloc(npages);
94 
95 	bio->bi_bdev = sbi->sb->s_bdev;
96 	bio->bi_iter.bi_sector = SECTOR_FROM_BLOCK(blk_addr);
97 	bio->bi_end_io = is_read ? f2fs_read_end_io : f2fs_write_end_io;
98 	bio->bi_private = is_read ? NULL : sbi;
99 
100 	return bio;
101 }
102 
103 static inline void __submit_bio(struct f2fs_sb_info *sbi,
104 				struct bio *bio, enum page_type type)
105 {
106 	if (!is_read_io(bio_op(bio))) {
107 		atomic_inc(&sbi->nr_wb_bios);
108 		if (f2fs_sb_mounted_hmsmr(sbi->sb) &&
109 			current->plug && (type == DATA || type == NODE))
110 			blk_finish_plug(current->plug);
111 	}
112 	submit_bio(bio);
113 }
114 
115 static void __submit_merged_bio(struct f2fs_bio_info *io)
116 {
117 	struct f2fs_io_info *fio = &io->fio;
118 
119 	if (!io->bio)
120 		return;
121 
122 	if (is_read_io(fio->op))
123 		trace_f2fs_submit_read_bio(io->sbi->sb, fio, io->bio);
124 	else
125 		trace_f2fs_submit_write_bio(io->sbi->sb, fio, io->bio);
126 
127 	bio_set_op_attrs(io->bio, fio->op, fio->op_flags);
128 
129 	__submit_bio(io->sbi, io->bio, fio->type);
130 	io->bio = NULL;
131 }
132 
133 static bool __has_merged_page(struct f2fs_bio_info *io, struct inode *inode,
134 						struct page *page, nid_t ino)
135 {
136 	struct bio_vec *bvec;
137 	struct page *target;
138 	int i;
139 
140 	if (!io->bio)
141 		return false;
142 
143 	if (!inode && !page && !ino)
144 		return true;
145 
146 	bio_for_each_segment_all(bvec, io->bio, i) {
147 
148 		if (bvec->bv_page->mapping)
149 			target = bvec->bv_page;
150 		else
151 			target = fscrypt_control_page(bvec->bv_page);
152 
153 		if (inode && inode == target->mapping->host)
154 			return true;
155 		if (page && page == target)
156 			return true;
157 		if (ino && ino == ino_of_node(target))
158 			return true;
159 	}
160 
161 	return false;
162 }
163 
164 static bool has_merged_page(struct f2fs_sb_info *sbi, struct inode *inode,
165 						struct page *page, nid_t ino,
166 						enum page_type type)
167 {
168 	enum page_type btype = PAGE_TYPE_OF_BIO(type);
169 	struct f2fs_bio_info *io = &sbi->write_io[btype];
170 	bool ret;
171 
172 	down_read(&io->io_rwsem);
173 	ret = __has_merged_page(io, inode, page, ino);
174 	up_read(&io->io_rwsem);
175 	return ret;
176 }
177 
178 static void __f2fs_submit_merged_bio(struct f2fs_sb_info *sbi,
179 				struct inode *inode, struct page *page,
180 				nid_t ino, enum page_type type, int rw)
181 {
182 	enum page_type btype = PAGE_TYPE_OF_BIO(type);
183 	struct f2fs_bio_info *io;
184 
185 	io = is_read_io(rw) ? &sbi->read_io : &sbi->write_io[btype];
186 
187 	down_write(&io->io_rwsem);
188 
189 	if (!__has_merged_page(io, inode, page, ino))
190 		goto out;
191 
192 	/* change META to META_FLUSH in the checkpoint procedure */
193 	if (type >= META_FLUSH) {
194 		io->fio.type = META_FLUSH;
195 		io->fio.op = REQ_OP_WRITE;
196 		if (test_opt(sbi, NOBARRIER))
197 			io->fio.op_flags = WRITE_FLUSH | REQ_META | REQ_PRIO;
198 		else
199 			io->fio.op_flags = WRITE_FLUSH_FUA | REQ_META |
200 								REQ_PRIO;
201 	}
202 	__submit_merged_bio(io);
203 out:
204 	up_write(&io->io_rwsem);
205 }
206 
207 void f2fs_submit_merged_bio(struct f2fs_sb_info *sbi, enum page_type type,
208 									int rw)
209 {
210 	__f2fs_submit_merged_bio(sbi, NULL, NULL, 0, type, rw);
211 }
212 
213 void f2fs_submit_merged_bio_cond(struct f2fs_sb_info *sbi,
214 				struct inode *inode, struct page *page,
215 				nid_t ino, enum page_type type, int rw)
216 {
217 	if (has_merged_page(sbi, inode, page, ino, type))
218 		__f2fs_submit_merged_bio(sbi, inode, page, ino, type, rw);
219 }
220 
221 void f2fs_flush_merged_bios(struct f2fs_sb_info *sbi)
222 {
223 	f2fs_submit_merged_bio(sbi, DATA, WRITE);
224 	f2fs_submit_merged_bio(sbi, NODE, WRITE);
225 	f2fs_submit_merged_bio(sbi, META, WRITE);
226 }
227 
228 /*
229  * Fill the locked page with data located in the block address.
230  * Return unlocked page.
231  */
232 int f2fs_submit_page_bio(struct f2fs_io_info *fio)
233 {
234 	struct bio *bio;
235 	struct page *page = fio->encrypted_page ?
236 			fio->encrypted_page : fio->page;
237 
238 	trace_f2fs_submit_page_bio(page, fio);
239 	f2fs_trace_ios(fio, 0);
240 
241 	/* Allocate a new bio */
242 	bio = __bio_alloc(fio->sbi, fio->new_blkaddr, 1, is_read_io(fio->op));
243 
244 	if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
245 		bio_put(bio);
246 		return -EFAULT;
247 	}
248 	bio_set_op_attrs(bio, fio->op, fio->op_flags);
249 
250 	__submit_bio(fio->sbi, bio, fio->type);
251 	return 0;
252 }
253 
254 void f2fs_submit_page_mbio(struct f2fs_io_info *fio)
255 {
256 	struct f2fs_sb_info *sbi = fio->sbi;
257 	enum page_type btype = PAGE_TYPE_OF_BIO(fio->type);
258 	struct f2fs_bio_info *io;
259 	bool is_read = is_read_io(fio->op);
260 	struct page *bio_page;
261 
262 	io = is_read ? &sbi->read_io : &sbi->write_io[btype];
263 
264 	if (fio->old_blkaddr != NEW_ADDR)
265 		verify_block_addr(sbi, fio->old_blkaddr);
266 	verify_block_addr(sbi, fio->new_blkaddr);
267 
268 	down_write(&io->io_rwsem);
269 
270 	if (io->bio && (io->last_block_in_bio != fio->new_blkaddr - 1 ||
271 	    (io->fio.op != fio->op || io->fio.op_flags != fio->op_flags)))
272 		__submit_merged_bio(io);
273 alloc_new:
274 	if (io->bio == NULL) {
275 		int bio_blocks = MAX_BIO_BLOCKS(sbi);
276 
277 		io->bio = __bio_alloc(sbi, fio->new_blkaddr,
278 						bio_blocks, is_read);
279 		io->fio = *fio;
280 	}
281 
282 	bio_page = fio->encrypted_page ? fio->encrypted_page : fio->page;
283 
284 	if (bio_add_page(io->bio, bio_page, PAGE_SIZE, 0) <
285 							PAGE_SIZE) {
286 		__submit_merged_bio(io);
287 		goto alloc_new;
288 	}
289 
290 	io->last_block_in_bio = fio->new_blkaddr;
291 	f2fs_trace_ios(fio, 0);
292 
293 	up_write(&io->io_rwsem);
294 	trace_f2fs_submit_page_mbio(fio->page, fio);
295 }
296 
297 static void __set_data_blkaddr(struct dnode_of_data *dn)
298 {
299 	struct f2fs_node *rn = F2FS_NODE(dn->node_page);
300 	__le32 *addr_array;
301 
302 	/* Get physical address of data block */
303 	addr_array = blkaddr_in_node(rn);
304 	addr_array[dn->ofs_in_node] = cpu_to_le32(dn->data_blkaddr);
305 }
306 
307 /*
308  * Lock ordering for the change of data block address:
309  * ->data_page
310  *  ->node_page
311  *    update block addresses in the node page
312  */
313 void set_data_blkaddr(struct dnode_of_data *dn)
314 {
315 	f2fs_wait_on_page_writeback(dn->node_page, NODE, true);
316 	__set_data_blkaddr(dn);
317 	if (set_page_dirty(dn->node_page))
318 		dn->node_changed = true;
319 }
320 
321 void f2fs_update_data_blkaddr(struct dnode_of_data *dn, block_t blkaddr)
322 {
323 	dn->data_blkaddr = blkaddr;
324 	set_data_blkaddr(dn);
325 	f2fs_update_extent_cache(dn);
326 }
327 
328 /* dn->ofs_in_node will be returned with up-to-date last block pointer */
329 int reserve_new_blocks(struct dnode_of_data *dn, blkcnt_t count)
330 {
331 	struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
332 
333 	if (!count)
334 		return 0;
335 
336 	if (unlikely(is_inode_flag_set(dn->inode, FI_NO_ALLOC)))
337 		return -EPERM;
338 	if (unlikely(!inc_valid_block_count(sbi, dn->inode, &count)))
339 		return -ENOSPC;
340 
341 	trace_f2fs_reserve_new_blocks(dn->inode, dn->nid,
342 						dn->ofs_in_node, count);
343 
344 	f2fs_wait_on_page_writeback(dn->node_page, NODE, true);
345 
346 	for (; count > 0; dn->ofs_in_node++) {
347 		block_t blkaddr =
348 			datablock_addr(dn->node_page, dn->ofs_in_node);
349 		if (blkaddr == NULL_ADDR) {
350 			dn->data_blkaddr = NEW_ADDR;
351 			__set_data_blkaddr(dn);
352 			count--;
353 		}
354 	}
355 
356 	if (set_page_dirty(dn->node_page))
357 		dn->node_changed = true;
358 	return 0;
359 }
360 
361 /* Should keep dn->ofs_in_node unchanged */
362 int reserve_new_block(struct dnode_of_data *dn)
363 {
364 	unsigned int ofs_in_node = dn->ofs_in_node;
365 	int ret;
366 
367 	ret = reserve_new_blocks(dn, 1);
368 	dn->ofs_in_node = ofs_in_node;
369 	return ret;
370 }
371 
372 int f2fs_reserve_block(struct dnode_of_data *dn, pgoff_t index)
373 {
374 	bool need_put = dn->inode_page ? false : true;
375 	int err;
376 
377 	err = get_dnode_of_data(dn, index, ALLOC_NODE);
378 	if (err)
379 		return err;
380 
381 	if (dn->data_blkaddr == NULL_ADDR)
382 		err = reserve_new_block(dn);
383 	if (err || need_put)
384 		f2fs_put_dnode(dn);
385 	return err;
386 }
387 
388 int f2fs_get_block(struct dnode_of_data *dn, pgoff_t index)
389 {
390 	struct extent_info ei;
391 	struct inode *inode = dn->inode;
392 
393 	if (f2fs_lookup_extent_cache(inode, index, &ei)) {
394 		dn->data_blkaddr = ei.blk + index - ei.fofs;
395 		return 0;
396 	}
397 
398 	return f2fs_reserve_block(dn, index);
399 }
400 
401 struct page *get_read_data_page(struct inode *inode, pgoff_t index,
402 						int op_flags, bool for_write)
403 {
404 	struct address_space *mapping = inode->i_mapping;
405 	struct dnode_of_data dn;
406 	struct page *page;
407 	struct extent_info ei;
408 	int err;
409 	struct f2fs_io_info fio = {
410 		.sbi = F2FS_I_SB(inode),
411 		.type = DATA,
412 		.op = REQ_OP_READ,
413 		.op_flags = op_flags,
414 		.encrypted_page = NULL,
415 	};
416 
417 	if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode))
418 		return read_mapping_page(mapping, index, NULL);
419 
420 	page = f2fs_grab_cache_page(mapping, index, for_write);
421 	if (!page)
422 		return ERR_PTR(-ENOMEM);
423 
424 	if (f2fs_lookup_extent_cache(inode, index, &ei)) {
425 		dn.data_blkaddr = ei.blk + index - ei.fofs;
426 		goto got_it;
427 	}
428 
429 	set_new_dnode(&dn, inode, NULL, NULL, 0);
430 	err = get_dnode_of_data(&dn, index, LOOKUP_NODE);
431 	if (err)
432 		goto put_err;
433 	f2fs_put_dnode(&dn);
434 
435 	if (unlikely(dn.data_blkaddr == NULL_ADDR)) {
436 		err = -ENOENT;
437 		goto put_err;
438 	}
439 got_it:
440 	if (PageUptodate(page)) {
441 		unlock_page(page);
442 		return page;
443 	}
444 
445 	/*
446 	 * A new dentry page is allocated but not able to be written, since its
447 	 * new inode page couldn't be allocated due to -ENOSPC.
448 	 * In such the case, its blkaddr can be remained as NEW_ADDR.
449 	 * see, f2fs_add_link -> get_new_data_page -> init_inode_metadata.
450 	 */
451 	if (dn.data_blkaddr == NEW_ADDR) {
452 		zero_user_segment(page, 0, PAGE_SIZE);
453 		if (!PageUptodate(page))
454 			SetPageUptodate(page);
455 		unlock_page(page);
456 		return page;
457 	}
458 
459 	fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
460 	fio.page = page;
461 	err = f2fs_submit_page_bio(&fio);
462 	if (err)
463 		goto put_err;
464 	return page;
465 
466 put_err:
467 	f2fs_put_page(page, 1);
468 	return ERR_PTR(err);
469 }
470 
471 struct page *find_data_page(struct inode *inode, pgoff_t index)
472 {
473 	struct address_space *mapping = inode->i_mapping;
474 	struct page *page;
475 
476 	page = find_get_page(mapping, index);
477 	if (page && PageUptodate(page))
478 		return page;
479 	f2fs_put_page(page, 0);
480 
481 	page = get_read_data_page(inode, index, READ_SYNC, false);
482 	if (IS_ERR(page))
483 		return page;
484 
485 	if (PageUptodate(page))
486 		return page;
487 
488 	wait_on_page_locked(page);
489 	if (unlikely(!PageUptodate(page))) {
490 		f2fs_put_page(page, 0);
491 		return ERR_PTR(-EIO);
492 	}
493 	return page;
494 }
495 
496 /*
497  * If it tries to access a hole, return an error.
498  * Because, the callers, functions in dir.c and GC, should be able to know
499  * whether this page exists or not.
500  */
501 struct page *get_lock_data_page(struct inode *inode, pgoff_t index,
502 							bool for_write)
503 {
504 	struct address_space *mapping = inode->i_mapping;
505 	struct page *page;
506 repeat:
507 	page = get_read_data_page(inode, index, READ_SYNC, for_write);
508 	if (IS_ERR(page))
509 		return page;
510 
511 	/* wait for read completion */
512 	lock_page(page);
513 	if (unlikely(page->mapping != mapping)) {
514 		f2fs_put_page(page, 1);
515 		goto repeat;
516 	}
517 	if (unlikely(!PageUptodate(page))) {
518 		f2fs_put_page(page, 1);
519 		return ERR_PTR(-EIO);
520 	}
521 	return page;
522 }
523 
524 /*
525  * Caller ensures that this data page is never allocated.
526  * A new zero-filled data page is allocated in the page cache.
527  *
528  * Also, caller should grab and release a rwsem by calling f2fs_lock_op() and
529  * f2fs_unlock_op().
530  * Note that, ipage is set only by make_empty_dir, and if any error occur,
531  * ipage should be released by this function.
532  */
533 struct page *get_new_data_page(struct inode *inode,
534 		struct page *ipage, pgoff_t index, bool new_i_size)
535 {
536 	struct address_space *mapping = inode->i_mapping;
537 	struct page *page;
538 	struct dnode_of_data dn;
539 	int err;
540 
541 	page = f2fs_grab_cache_page(mapping, index, true);
542 	if (!page) {
543 		/*
544 		 * before exiting, we should make sure ipage will be released
545 		 * if any error occur.
546 		 */
547 		f2fs_put_page(ipage, 1);
548 		return ERR_PTR(-ENOMEM);
549 	}
550 
551 	set_new_dnode(&dn, inode, ipage, NULL, 0);
552 	err = f2fs_reserve_block(&dn, index);
553 	if (err) {
554 		f2fs_put_page(page, 1);
555 		return ERR_PTR(err);
556 	}
557 	if (!ipage)
558 		f2fs_put_dnode(&dn);
559 
560 	if (PageUptodate(page))
561 		goto got_it;
562 
563 	if (dn.data_blkaddr == NEW_ADDR) {
564 		zero_user_segment(page, 0, PAGE_SIZE);
565 		if (!PageUptodate(page))
566 			SetPageUptodate(page);
567 	} else {
568 		f2fs_put_page(page, 1);
569 
570 		/* if ipage exists, blkaddr should be NEW_ADDR */
571 		f2fs_bug_on(F2FS_I_SB(inode), ipage);
572 		page = get_lock_data_page(inode, index, true);
573 		if (IS_ERR(page))
574 			return page;
575 	}
576 got_it:
577 	if (new_i_size && i_size_read(inode) <
578 				((loff_t)(index + 1) << PAGE_SHIFT))
579 		f2fs_i_size_write(inode, ((loff_t)(index + 1) << PAGE_SHIFT));
580 	return page;
581 }
582 
583 static int __allocate_data_block(struct dnode_of_data *dn)
584 {
585 	struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
586 	struct f2fs_summary sum;
587 	struct node_info ni;
588 	int seg = CURSEG_WARM_DATA;
589 	pgoff_t fofs;
590 	blkcnt_t count = 1;
591 
592 	if (unlikely(is_inode_flag_set(dn->inode, FI_NO_ALLOC)))
593 		return -EPERM;
594 
595 	dn->data_blkaddr = datablock_addr(dn->node_page, dn->ofs_in_node);
596 	if (dn->data_blkaddr == NEW_ADDR)
597 		goto alloc;
598 
599 	if (unlikely(!inc_valid_block_count(sbi, dn->inode, &count)))
600 		return -ENOSPC;
601 
602 alloc:
603 	get_node_info(sbi, dn->nid, &ni);
604 	set_summary(&sum, dn->nid, dn->ofs_in_node, ni.version);
605 
606 	if (dn->ofs_in_node == 0 && dn->inode_page == dn->node_page)
607 		seg = CURSEG_DIRECT_IO;
608 
609 	allocate_data_block(sbi, NULL, dn->data_blkaddr, &dn->data_blkaddr,
610 								&sum, seg);
611 	set_data_blkaddr(dn);
612 
613 	/* update i_size */
614 	fofs = start_bidx_of_node(ofs_of_node(dn->node_page), dn->inode) +
615 							dn->ofs_in_node;
616 	if (i_size_read(dn->inode) < ((loff_t)(fofs + 1) << PAGE_SHIFT))
617 		f2fs_i_size_write(dn->inode,
618 				((loff_t)(fofs + 1) << PAGE_SHIFT));
619 	return 0;
620 }
621 
622 ssize_t f2fs_preallocate_blocks(struct kiocb *iocb, struct iov_iter *from)
623 {
624 	struct inode *inode = file_inode(iocb->ki_filp);
625 	struct f2fs_map_blocks map;
626 	ssize_t ret = 0;
627 
628 	map.m_lblk = F2FS_BLK_ALIGN(iocb->ki_pos);
629 	map.m_len = F2FS_BYTES_TO_BLK(iov_iter_count(from));
630 	map.m_next_pgofs = NULL;
631 
632 	if (f2fs_encrypted_inode(inode))
633 		return 0;
634 
635 	if (iocb->ki_flags & IOCB_DIRECT) {
636 		ret = f2fs_convert_inline_inode(inode);
637 		if (ret)
638 			return ret;
639 		return f2fs_map_blocks(inode, &map, 1, F2FS_GET_BLOCK_PRE_DIO);
640 	}
641 	if (iocb->ki_pos + iov_iter_count(from) > MAX_INLINE_DATA) {
642 		ret = f2fs_convert_inline_inode(inode);
643 		if (ret)
644 			return ret;
645 	}
646 	if (!f2fs_has_inline_data(inode))
647 		return f2fs_map_blocks(inode, &map, 1, F2FS_GET_BLOCK_PRE_AIO);
648 	return ret;
649 }
650 
651 /*
652  * f2fs_map_blocks() now supported readahead/bmap/rw direct_IO with
653  * f2fs_map_blocks structure.
654  * If original data blocks are allocated, then give them to blockdev.
655  * Otherwise,
656  *     a. preallocate requested block addresses
657  *     b. do not use extent cache for better performance
658  *     c. give the block addresses to blockdev
659  */
660 int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map,
661 						int create, int flag)
662 {
663 	unsigned int maxblocks = map->m_len;
664 	struct dnode_of_data dn;
665 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
666 	int mode = create ? ALLOC_NODE : LOOKUP_NODE;
667 	pgoff_t pgofs, end_offset, end;
668 	int err = 0, ofs = 1;
669 	unsigned int ofs_in_node, last_ofs_in_node;
670 	blkcnt_t prealloc;
671 	struct extent_info ei;
672 	bool allocated = false;
673 	block_t blkaddr;
674 
675 	map->m_len = 0;
676 	map->m_flags = 0;
677 
678 	/* it only supports block size == page size */
679 	pgofs =	(pgoff_t)map->m_lblk;
680 	end = pgofs + maxblocks;
681 
682 	if (!create && f2fs_lookup_extent_cache(inode, pgofs, &ei)) {
683 		map->m_pblk = ei.blk + pgofs - ei.fofs;
684 		map->m_len = min((pgoff_t)maxblocks, ei.fofs + ei.len - pgofs);
685 		map->m_flags = F2FS_MAP_MAPPED;
686 		goto out;
687 	}
688 
689 next_dnode:
690 	if (create)
691 		f2fs_lock_op(sbi);
692 
693 	/* When reading holes, we need its node page */
694 	set_new_dnode(&dn, inode, NULL, NULL, 0);
695 	err = get_dnode_of_data(&dn, pgofs, mode);
696 	if (err) {
697 		if (flag == F2FS_GET_BLOCK_BMAP)
698 			map->m_pblk = 0;
699 		if (err == -ENOENT) {
700 			err = 0;
701 			if (map->m_next_pgofs)
702 				*map->m_next_pgofs =
703 					get_next_page_offset(&dn, pgofs);
704 		}
705 		goto unlock_out;
706 	}
707 
708 	prealloc = 0;
709 	ofs_in_node = dn.ofs_in_node;
710 	end_offset = ADDRS_PER_PAGE(dn.node_page, inode);
711 
712 next_block:
713 	blkaddr = datablock_addr(dn.node_page, dn.ofs_in_node);
714 
715 	if (blkaddr == NEW_ADDR || blkaddr == NULL_ADDR) {
716 		if (create) {
717 			if (unlikely(f2fs_cp_error(sbi))) {
718 				err = -EIO;
719 				goto sync_out;
720 			}
721 			if (flag == F2FS_GET_BLOCK_PRE_AIO) {
722 				if (blkaddr == NULL_ADDR) {
723 					prealloc++;
724 					last_ofs_in_node = dn.ofs_in_node;
725 				}
726 			} else {
727 				err = __allocate_data_block(&dn);
728 				if (!err) {
729 					set_inode_flag(inode, FI_APPEND_WRITE);
730 					allocated = true;
731 				}
732 			}
733 			if (err)
734 				goto sync_out;
735 			map->m_flags = F2FS_MAP_NEW;
736 			blkaddr = dn.data_blkaddr;
737 		} else {
738 			if (flag == F2FS_GET_BLOCK_BMAP) {
739 				map->m_pblk = 0;
740 				goto sync_out;
741 			}
742 			if (flag == F2FS_GET_BLOCK_FIEMAP &&
743 						blkaddr == NULL_ADDR) {
744 				if (map->m_next_pgofs)
745 					*map->m_next_pgofs = pgofs + 1;
746 			}
747 			if (flag != F2FS_GET_BLOCK_FIEMAP ||
748 						blkaddr != NEW_ADDR)
749 				goto sync_out;
750 		}
751 	}
752 
753 	if (flag == F2FS_GET_BLOCK_PRE_AIO)
754 		goto skip;
755 
756 	if (map->m_len == 0) {
757 		/* preallocated unwritten block should be mapped for fiemap. */
758 		if (blkaddr == NEW_ADDR)
759 			map->m_flags |= F2FS_MAP_UNWRITTEN;
760 		map->m_flags |= F2FS_MAP_MAPPED;
761 
762 		map->m_pblk = blkaddr;
763 		map->m_len = 1;
764 	} else if ((map->m_pblk != NEW_ADDR &&
765 			blkaddr == (map->m_pblk + ofs)) ||
766 			(map->m_pblk == NEW_ADDR && blkaddr == NEW_ADDR) ||
767 			flag == F2FS_GET_BLOCK_PRE_DIO) {
768 		ofs++;
769 		map->m_len++;
770 	} else {
771 		goto sync_out;
772 	}
773 
774 skip:
775 	dn.ofs_in_node++;
776 	pgofs++;
777 
778 	/* preallocate blocks in batch for one dnode page */
779 	if (flag == F2FS_GET_BLOCK_PRE_AIO &&
780 			(pgofs == end || dn.ofs_in_node == end_offset)) {
781 
782 		dn.ofs_in_node = ofs_in_node;
783 		err = reserve_new_blocks(&dn, prealloc);
784 		if (err)
785 			goto sync_out;
786 
787 		map->m_len += dn.ofs_in_node - ofs_in_node;
788 		if (prealloc && dn.ofs_in_node != last_ofs_in_node + 1) {
789 			err = -ENOSPC;
790 			goto sync_out;
791 		}
792 		dn.ofs_in_node = end_offset;
793 	}
794 
795 	if (pgofs >= end)
796 		goto sync_out;
797 	else if (dn.ofs_in_node < end_offset)
798 		goto next_block;
799 
800 	f2fs_put_dnode(&dn);
801 
802 	if (create) {
803 		f2fs_unlock_op(sbi);
804 		f2fs_balance_fs(sbi, allocated);
805 	}
806 	allocated = false;
807 	goto next_dnode;
808 
809 sync_out:
810 	f2fs_put_dnode(&dn);
811 unlock_out:
812 	if (create) {
813 		f2fs_unlock_op(sbi);
814 		f2fs_balance_fs(sbi, allocated);
815 	}
816 out:
817 	trace_f2fs_map_blocks(inode, map, err);
818 	return err;
819 }
820 
821 static int __get_data_block(struct inode *inode, sector_t iblock,
822 			struct buffer_head *bh, int create, int flag,
823 			pgoff_t *next_pgofs)
824 {
825 	struct f2fs_map_blocks map;
826 	int ret;
827 
828 	map.m_lblk = iblock;
829 	map.m_len = bh->b_size >> inode->i_blkbits;
830 	map.m_next_pgofs = next_pgofs;
831 
832 	ret = f2fs_map_blocks(inode, &map, create, flag);
833 	if (!ret) {
834 		map_bh(bh, inode->i_sb, map.m_pblk);
835 		bh->b_state = (bh->b_state & ~F2FS_MAP_FLAGS) | map.m_flags;
836 		bh->b_size = map.m_len << inode->i_blkbits;
837 	}
838 	return ret;
839 }
840 
841 static int get_data_block(struct inode *inode, sector_t iblock,
842 			struct buffer_head *bh_result, int create, int flag,
843 			pgoff_t *next_pgofs)
844 {
845 	return __get_data_block(inode, iblock, bh_result, create,
846 							flag, next_pgofs);
847 }
848 
849 static int get_data_block_dio(struct inode *inode, sector_t iblock,
850 			struct buffer_head *bh_result, int create)
851 {
852 	return __get_data_block(inode, iblock, bh_result, create,
853 						F2FS_GET_BLOCK_DIO, NULL);
854 }
855 
856 static int get_data_block_bmap(struct inode *inode, sector_t iblock,
857 			struct buffer_head *bh_result, int create)
858 {
859 	/* Block number less than F2FS MAX BLOCKS */
860 	if (unlikely(iblock >= F2FS_I_SB(inode)->max_file_blocks))
861 		return -EFBIG;
862 
863 	return __get_data_block(inode, iblock, bh_result, create,
864 						F2FS_GET_BLOCK_BMAP, NULL);
865 }
866 
867 static inline sector_t logical_to_blk(struct inode *inode, loff_t offset)
868 {
869 	return (offset >> inode->i_blkbits);
870 }
871 
872 static inline loff_t blk_to_logical(struct inode *inode, sector_t blk)
873 {
874 	return (blk << inode->i_blkbits);
875 }
876 
877 int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
878 		u64 start, u64 len)
879 {
880 	struct buffer_head map_bh;
881 	sector_t start_blk, last_blk;
882 	pgoff_t next_pgofs;
883 	loff_t isize;
884 	u64 logical = 0, phys = 0, size = 0;
885 	u32 flags = 0;
886 	int ret = 0;
887 
888 	ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC);
889 	if (ret)
890 		return ret;
891 
892 	if (f2fs_has_inline_data(inode)) {
893 		ret = f2fs_inline_data_fiemap(inode, fieinfo, start, len);
894 		if (ret != -EAGAIN)
895 			return ret;
896 	}
897 
898 	inode_lock(inode);
899 
900 	isize = i_size_read(inode);
901 	if (start >= isize)
902 		goto out;
903 
904 	if (start + len > isize)
905 		len = isize - start;
906 
907 	if (logical_to_blk(inode, len) == 0)
908 		len = blk_to_logical(inode, 1);
909 
910 	start_blk = logical_to_blk(inode, start);
911 	last_blk = logical_to_blk(inode, start + len - 1);
912 
913 next:
914 	memset(&map_bh, 0, sizeof(struct buffer_head));
915 	map_bh.b_size = len;
916 
917 	ret = get_data_block(inode, start_blk, &map_bh, 0,
918 					F2FS_GET_BLOCK_FIEMAP, &next_pgofs);
919 	if (ret)
920 		goto out;
921 
922 	/* HOLE */
923 	if (!buffer_mapped(&map_bh)) {
924 		start_blk = next_pgofs;
925 		/* Go through holes util pass the EOF */
926 		if (blk_to_logical(inode, start_blk) < isize)
927 			goto prep_next;
928 		/* Found a hole beyond isize means no more extents.
929 		 * Note that the premise is that filesystems don't
930 		 * punch holes beyond isize and keep size unchanged.
931 		 */
932 		flags |= FIEMAP_EXTENT_LAST;
933 	}
934 
935 	if (size) {
936 		if (f2fs_encrypted_inode(inode))
937 			flags |= FIEMAP_EXTENT_DATA_ENCRYPTED;
938 
939 		ret = fiemap_fill_next_extent(fieinfo, logical,
940 				phys, size, flags);
941 	}
942 
943 	if (start_blk > last_blk || ret)
944 		goto out;
945 
946 	logical = blk_to_logical(inode, start_blk);
947 	phys = blk_to_logical(inode, map_bh.b_blocknr);
948 	size = map_bh.b_size;
949 	flags = 0;
950 	if (buffer_unwritten(&map_bh))
951 		flags = FIEMAP_EXTENT_UNWRITTEN;
952 
953 	start_blk += logical_to_blk(inode, size);
954 
955 prep_next:
956 	cond_resched();
957 	if (fatal_signal_pending(current))
958 		ret = -EINTR;
959 	else
960 		goto next;
961 out:
962 	if (ret == 1)
963 		ret = 0;
964 
965 	inode_unlock(inode);
966 	return ret;
967 }
968 
969 struct bio *f2fs_grab_bio(struct inode *inode, block_t blkaddr,
970 							unsigned nr_pages)
971 {
972 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
973 	struct fscrypt_ctx *ctx = NULL;
974 	struct block_device *bdev = sbi->sb->s_bdev;
975 	struct bio *bio;
976 
977 	if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode)) {
978 		ctx = fscrypt_get_ctx(inode, GFP_NOFS);
979 		if (IS_ERR(ctx))
980 			return ERR_CAST(ctx);
981 
982 		/* wait the page to be moved by cleaning */
983 		f2fs_wait_on_encrypted_page_writeback(sbi, blkaddr);
984 	}
985 
986 	bio = bio_alloc(GFP_KERNEL, min_t(int, nr_pages, BIO_MAX_PAGES));
987 	if (!bio) {
988 		if (ctx)
989 			fscrypt_release_ctx(ctx);
990 		return ERR_PTR(-ENOMEM);
991 	}
992 	bio->bi_bdev = bdev;
993 	bio->bi_iter.bi_sector = SECTOR_FROM_BLOCK(blkaddr);
994 	bio->bi_end_io = f2fs_read_end_io;
995 	bio->bi_private = ctx;
996 
997 	return bio;
998 }
999 
1000 /*
1001  * This function was originally taken from fs/mpage.c, and customized for f2fs.
1002  * Major change was from block_size == page_size in f2fs by default.
1003  */
1004 static int f2fs_mpage_readpages(struct address_space *mapping,
1005 			struct list_head *pages, struct page *page,
1006 			unsigned nr_pages)
1007 {
1008 	struct bio *bio = NULL;
1009 	unsigned page_idx;
1010 	sector_t last_block_in_bio = 0;
1011 	struct inode *inode = mapping->host;
1012 	const unsigned blkbits = inode->i_blkbits;
1013 	const unsigned blocksize = 1 << blkbits;
1014 	sector_t block_in_file;
1015 	sector_t last_block;
1016 	sector_t last_block_in_file;
1017 	sector_t block_nr;
1018 	struct f2fs_map_blocks map;
1019 
1020 	map.m_pblk = 0;
1021 	map.m_lblk = 0;
1022 	map.m_len = 0;
1023 	map.m_flags = 0;
1024 	map.m_next_pgofs = NULL;
1025 
1026 	for (page_idx = 0; nr_pages; page_idx++, nr_pages--) {
1027 
1028 		prefetchw(&page->flags);
1029 		if (pages) {
1030 			page = list_entry(pages->prev, struct page, lru);
1031 			list_del(&page->lru);
1032 			if (add_to_page_cache_lru(page, mapping,
1033 						  page->index,
1034 						  readahead_gfp_mask(mapping)))
1035 				goto next_page;
1036 		}
1037 
1038 		block_in_file = (sector_t)page->index;
1039 		last_block = block_in_file + nr_pages;
1040 		last_block_in_file = (i_size_read(inode) + blocksize - 1) >>
1041 								blkbits;
1042 		if (last_block > last_block_in_file)
1043 			last_block = last_block_in_file;
1044 
1045 		/*
1046 		 * Map blocks using the previous result first.
1047 		 */
1048 		if ((map.m_flags & F2FS_MAP_MAPPED) &&
1049 				block_in_file > map.m_lblk &&
1050 				block_in_file < (map.m_lblk + map.m_len))
1051 			goto got_it;
1052 
1053 		/*
1054 		 * Then do more f2fs_map_blocks() calls until we are
1055 		 * done with this page.
1056 		 */
1057 		map.m_flags = 0;
1058 
1059 		if (block_in_file < last_block) {
1060 			map.m_lblk = block_in_file;
1061 			map.m_len = last_block - block_in_file;
1062 
1063 			if (f2fs_map_blocks(inode, &map, 0,
1064 						F2FS_GET_BLOCK_READ))
1065 				goto set_error_page;
1066 		}
1067 got_it:
1068 		if ((map.m_flags & F2FS_MAP_MAPPED)) {
1069 			block_nr = map.m_pblk + block_in_file - map.m_lblk;
1070 			SetPageMappedToDisk(page);
1071 
1072 			if (!PageUptodate(page) && !cleancache_get_page(page)) {
1073 				SetPageUptodate(page);
1074 				goto confused;
1075 			}
1076 		} else {
1077 			zero_user_segment(page, 0, PAGE_SIZE);
1078 			if (!PageUptodate(page))
1079 				SetPageUptodate(page);
1080 			unlock_page(page);
1081 			goto next_page;
1082 		}
1083 
1084 		/*
1085 		 * This page will go to BIO.  Do we need to send this
1086 		 * BIO off first?
1087 		 */
1088 		if (bio && (last_block_in_bio != block_nr - 1)) {
1089 submit_and_realloc:
1090 			__submit_bio(F2FS_I_SB(inode), bio, DATA);
1091 			bio = NULL;
1092 		}
1093 		if (bio == NULL) {
1094 			bio = f2fs_grab_bio(inode, block_nr, nr_pages);
1095 			if (IS_ERR(bio)) {
1096 				bio = NULL;
1097 				goto set_error_page;
1098 			}
1099 			bio_set_op_attrs(bio, REQ_OP_READ, 0);
1100 		}
1101 
1102 		if (bio_add_page(bio, page, blocksize, 0) < blocksize)
1103 			goto submit_and_realloc;
1104 
1105 		last_block_in_bio = block_nr;
1106 		goto next_page;
1107 set_error_page:
1108 		SetPageError(page);
1109 		zero_user_segment(page, 0, PAGE_SIZE);
1110 		unlock_page(page);
1111 		goto next_page;
1112 confused:
1113 		if (bio) {
1114 			__submit_bio(F2FS_I_SB(inode), bio, DATA);
1115 			bio = NULL;
1116 		}
1117 		unlock_page(page);
1118 next_page:
1119 		if (pages)
1120 			put_page(page);
1121 	}
1122 	BUG_ON(pages && !list_empty(pages));
1123 	if (bio)
1124 		__submit_bio(F2FS_I_SB(inode), bio, DATA);
1125 	return 0;
1126 }
1127 
1128 static int f2fs_read_data_page(struct file *file, struct page *page)
1129 {
1130 	struct inode *inode = page->mapping->host;
1131 	int ret = -EAGAIN;
1132 
1133 	trace_f2fs_readpage(page, DATA);
1134 
1135 	/* If the file has inline data, try to read it directly */
1136 	if (f2fs_has_inline_data(inode))
1137 		ret = f2fs_read_inline_data(inode, page);
1138 	if (ret == -EAGAIN)
1139 		ret = f2fs_mpage_readpages(page->mapping, NULL, page, 1);
1140 	return ret;
1141 }
1142 
1143 static int f2fs_read_data_pages(struct file *file,
1144 			struct address_space *mapping,
1145 			struct list_head *pages, unsigned nr_pages)
1146 {
1147 	struct inode *inode = file->f_mapping->host;
1148 	struct page *page = list_entry(pages->prev, struct page, lru);
1149 
1150 	trace_f2fs_readpages(inode, page, nr_pages);
1151 
1152 	/* If the file has inline data, skip readpages */
1153 	if (f2fs_has_inline_data(inode))
1154 		return 0;
1155 
1156 	return f2fs_mpage_readpages(mapping, pages, NULL, nr_pages);
1157 }
1158 
1159 int do_write_data_page(struct f2fs_io_info *fio)
1160 {
1161 	struct page *page = fio->page;
1162 	struct inode *inode = page->mapping->host;
1163 	struct dnode_of_data dn;
1164 	int err = 0;
1165 
1166 	set_new_dnode(&dn, inode, NULL, NULL, 0);
1167 	err = get_dnode_of_data(&dn, page->index, LOOKUP_NODE);
1168 	if (err)
1169 		return err;
1170 
1171 	fio->old_blkaddr = dn.data_blkaddr;
1172 
1173 	/* This page is already truncated */
1174 	if (fio->old_blkaddr == NULL_ADDR) {
1175 		ClearPageUptodate(page);
1176 		goto out_writepage;
1177 	}
1178 
1179 	if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode)) {
1180 		gfp_t gfp_flags = GFP_NOFS;
1181 
1182 		/* wait for GCed encrypted page writeback */
1183 		f2fs_wait_on_encrypted_page_writeback(F2FS_I_SB(inode),
1184 							fio->old_blkaddr);
1185 retry_encrypt:
1186 		fio->encrypted_page = fscrypt_encrypt_page(inode, fio->page,
1187 								gfp_flags);
1188 		if (IS_ERR(fio->encrypted_page)) {
1189 			err = PTR_ERR(fio->encrypted_page);
1190 			if (err == -ENOMEM) {
1191 				/* flush pending ios and wait for a while */
1192 				f2fs_flush_merged_bios(F2FS_I_SB(inode));
1193 				congestion_wait(BLK_RW_ASYNC, HZ/50);
1194 				gfp_flags |= __GFP_NOFAIL;
1195 				err = 0;
1196 				goto retry_encrypt;
1197 			}
1198 			goto out_writepage;
1199 		}
1200 	}
1201 
1202 	set_page_writeback(page);
1203 
1204 	/*
1205 	 * If current allocation needs SSR,
1206 	 * it had better in-place writes for updated data.
1207 	 */
1208 	if (unlikely(fio->old_blkaddr != NEW_ADDR &&
1209 			!is_cold_data(page) &&
1210 			!IS_ATOMIC_WRITTEN_PAGE(page) &&
1211 			need_inplace_update(inode))) {
1212 		rewrite_data_page(fio);
1213 		set_inode_flag(inode, FI_UPDATE_WRITE);
1214 		trace_f2fs_do_write_data_page(page, IPU);
1215 	} else {
1216 		write_data_page(&dn, fio);
1217 		trace_f2fs_do_write_data_page(page, OPU);
1218 		set_inode_flag(inode, FI_APPEND_WRITE);
1219 		if (page->index == 0)
1220 			set_inode_flag(inode, FI_FIRST_BLOCK_WRITTEN);
1221 	}
1222 out_writepage:
1223 	f2fs_put_dnode(&dn);
1224 	return err;
1225 }
1226 
1227 static int f2fs_write_data_page(struct page *page,
1228 					struct writeback_control *wbc)
1229 {
1230 	struct inode *inode = page->mapping->host;
1231 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1232 	loff_t i_size = i_size_read(inode);
1233 	const pgoff_t end_index = ((unsigned long long) i_size)
1234 							>> PAGE_SHIFT;
1235 	loff_t psize = (page->index + 1) << PAGE_SHIFT;
1236 	unsigned offset = 0;
1237 	bool need_balance_fs = false;
1238 	int err = 0;
1239 	struct f2fs_io_info fio = {
1240 		.sbi = sbi,
1241 		.type = DATA,
1242 		.op = REQ_OP_WRITE,
1243 		.op_flags = (wbc->sync_mode == WB_SYNC_ALL) ? WRITE_SYNC : 0,
1244 		.page = page,
1245 		.encrypted_page = NULL,
1246 	};
1247 
1248 	trace_f2fs_writepage(page, DATA);
1249 
1250 	if (page->index < end_index)
1251 		goto write;
1252 
1253 	/*
1254 	 * If the offset is out-of-range of file size,
1255 	 * this page does not have to be written to disk.
1256 	 */
1257 	offset = i_size & (PAGE_SIZE - 1);
1258 	if ((page->index >= end_index + 1) || !offset)
1259 		goto out;
1260 
1261 	zero_user_segment(page, offset, PAGE_SIZE);
1262 write:
1263 	if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
1264 		goto redirty_out;
1265 	if (f2fs_is_drop_cache(inode))
1266 		goto out;
1267 	/* we should not write 0'th page having journal header */
1268 	if (f2fs_is_volatile_file(inode) && (!page->index ||
1269 			(!wbc->for_reclaim &&
1270 			available_free_memory(sbi, BASE_CHECK))))
1271 		goto redirty_out;
1272 
1273 	/* we should bypass data pages to proceed the kworkder jobs */
1274 	if (unlikely(f2fs_cp_error(sbi))) {
1275 		mapping_set_error(page->mapping, -EIO);
1276 		goto out;
1277 	}
1278 
1279 	/* Dentry blocks are controlled by checkpoint */
1280 	if (S_ISDIR(inode->i_mode)) {
1281 		err = do_write_data_page(&fio);
1282 		goto done;
1283 	}
1284 
1285 	if (!wbc->for_reclaim)
1286 		need_balance_fs = true;
1287 	else if (has_not_enough_free_secs(sbi, 0))
1288 		goto redirty_out;
1289 
1290 	err = -EAGAIN;
1291 	f2fs_lock_op(sbi);
1292 	if (f2fs_has_inline_data(inode))
1293 		err = f2fs_write_inline_data(inode, page);
1294 	if (err == -EAGAIN)
1295 		err = do_write_data_page(&fio);
1296 	if (F2FS_I(inode)->last_disk_size < psize)
1297 		F2FS_I(inode)->last_disk_size = psize;
1298 	f2fs_unlock_op(sbi);
1299 done:
1300 	if (err && err != -ENOENT)
1301 		goto redirty_out;
1302 
1303 	clear_cold_data(page);
1304 out:
1305 	inode_dec_dirty_pages(inode);
1306 	if (err)
1307 		ClearPageUptodate(page);
1308 
1309 	if (wbc->for_reclaim) {
1310 		f2fs_submit_merged_bio_cond(sbi, NULL, page, 0, DATA, WRITE);
1311 		remove_dirty_inode(inode);
1312 	}
1313 
1314 	unlock_page(page);
1315 	f2fs_balance_fs(sbi, need_balance_fs);
1316 
1317 	if (unlikely(f2fs_cp_error(sbi)))
1318 		f2fs_submit_merged_bio(sbi, DATA, WRITE);
1319 
1320 	return 0;
1321 
1322 redirty_out:
1323 	redirty_page_for_writepage(wbc, page);
1324 	unlock_page(page);
1325 	return err;
1326 }
1327 
1328 /*
1329  * This function was copied from write_cche_pages from mm/page-writeback.c.
1330  * The major change is making write step of cold data page separately from
1331  * warm/hot data page.
1332  */
1333 static int f2fs_write_cache_pages(struct address_space *mapping,
1334 					struct writeback_control *wbc)
1335 {
1336 	int ret = 0;
1337 	int done = 0;
1338 	struct pagevec pvec;
1339 	int nr_pages;
1340 	pgoff_t uninitialized_var(writeback_index);
1341 	pgoff_t index;
1342 	pgoff_t end;		/* Inclusive */
1343 	pgoff_t done_index;
1344 	int cycled;
1345 	int range_whole = 0;
1346 	int tag;
1347 
1348 	pagevec_init(&pvec, 0);
1349 
1350 	if (wbc->range_cyclic) {
1351 		writeback_index = mapping->writeback_index; /* prev offset */
1352 		index = writeback_index;
1353 		if (index == 0)
1354 			cycled = 1;
1355 		else
1356 			cycled = 0;
1357 		end = -1;
1358 	} else {
1359 		index = wbc->range_start >> PAGE_SHIFT;
1360 		end = wbc->range_end >> PAGE_SHIFT;
1361 		if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
1362 			range_whole = 1;
1363 		cycled = 1; /* ignore range_cyclic tests */
1364 	}
1365 	if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
1366 		tag = PAGECACHE_TAG_TOWRITE;
1367 	else
1368 		tag = PAGECACHE_TAG_DIRTY;
1369 retry:
1370 	if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
1371 		tag_pages_for_writeback(mapping, index, end);
1372 	done_index = index;
1373 	while (!done && (index <= end)) {
1374 		int i;
1375 
1376 		nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
1377 			      min(end - index, (pgoff_t)PAGEVEC_SIZE - 1) + 1);
1378 		if (nr_pages == 0)
1379 			break;
1380 
1381 		for (i = 0; i < nr_pages; i++) {
1382 			struct page *page = pvec.pages[i];
1383 
1384 			if (page->index > end) {
1385 				done = 1;
1386 				break;
1387 			}
1388 
1389 			done_index = page->index;
1390 
1391 			lock_page(page);
1392 
1393 			if (unlikely(page->mapping != mapping)) {
1394 continue_unlock:
1395 				unlock_page(page);
1396 				continue;
1397 			}
1398 
1399 			if (!PageDirty(page)) {
1400 				/* someone wrote it for us */
1401 				goto continue_unlock;
1402 			}
1403 
1404 			if (PageWriteback(page)) {
1405 				if (wbc->sync_mode != WB_SYNC_NONE)
1406 					f2fs_wait_on_page_writeback(page,
1407 								DATA, true);
1408 				else
1409 					goto continue_unlock;
1410 			}
1411 
1412 			BUG_ON(PageWriteback(page));
1413 			if (!clear_page_dirty_for_io(page))
1414 				goto continue_unlock;
1415 
1416 			ret = mapping->a_ops->writepage(page, wbc);
1417 			if (unlikely(ret)) {
1418 				done_index = page->index + 1;
1419 				done = 1;
1420 				break;
1421 			}
1422 
1423 			if (--wbc->nr_to_write <= 0 &&
1424 			    wbc->sync_mode == WB_SYNC_NONE) {
1425 				done = 1;
1426 				break;
1427 			}
1428 		}
1429 		pagevec_release(&pvec);
1430 		cond_resched();
1431 	}
1432 
1433 	if (!cycled && !done) {
1434 		cycled = 1;
1435 		index = 0;
1436 		end = writeback_index - 1;
1437 		goto retry;
1438 	}
1439 	if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
1440 		mapping->writeback_index = done_index;
1441 
1442 	return ret;
1443 }
1444 
1445 static int f2fs_write_data_pages(struct address_space *mapping,
1446 			    struct writeback_control *wbc)
1447 {
1448 	struct inode *inode = mapping->host;
1449 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1450 	struct blk_plug plug;
1451 	int ret;
1452 
1453 	/* deal with chardevs and other special file */
1454 	if (!mapping->a_ops->writepage)
1455 		return 0;
1456 
1457 	/* skip writing if there is no dirty page in this inode */
1458 	if (!get_dirty_pages(inode) && wbc->sync_mode == WB_SYNC_NONE)
1459 		return 0;
1460 
1461 	if (S_ISDIR(inode->i_mode) && wbc->sync_mode == WB_SYNC_NONE &&
1462 			get_dirty_pages(inode) < nr_pages_to_skip(sbi, DATA) &&
1463 			available_free_memory(sbi, DIRTY_DENTS))
1464 		goto skip_write;
1465 
1466 	/* skip writing during file defragment */
1467 	if (is_inode_flag_set(inode, FI_DO_DEFRAG))
1468 		goto skip_write;
1469 
1470 	/* during POR, we don't need to trigger writepage at all. */
1471 	if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
1472 		goto skip_write;
1473 
1474 	trace_f2fs_writepages(mapping->host, wbc, DATA);
1475 
1476 	blk_start_plug(&plug);
1477 	ret = f2fs_write_cache_pages(mapping, wbc);
1478 	blk_finish_plug(&plug);
1479 	/*
1480 	 * if some pages were truncated, we cannot guarantee its mapping->host
1481 	 * to detect pending bios.
1482 	 */
1483 	f2fs_submit_merged_bio(sbi, DATA, WRITE);
1484 
1485 	remove_dirty_inode(inode);
1486 	return ret;
1487 
1488 skip_write:
1489 	wbc->pages_skipped += get_dirty_pages(inode);
1490 	trace_f2fs_writepages(mapping->host, wbc, DATA);
1491 	return 0;
1492 }
1493 
1494 static void f2fs_write_failed(struct address_space *mapping, loff_t to)
1495 {
1496 	struct inode *inode = mapping->host;
1497 	loff_t i_size = i_size_read(inode);
1498 
1499 	if (to > i_size) {
1500 		truncate_pagecache(inode, i_size);
1501 		truncate_blocks(inode, i_size, true);
1502 	}
1503 }
1504 
1505 static int prepare_write_begin(struct f2fs_sb_info *sbi,
1506 			struct page *page, loff_t pos, unsigned len,
1507 			block_t *blk_addr, bool *node_changed)
1508 {
1509 	struct inode *inode = page->mapping->host;
1510 	pgoff_t index = page->index;
1511 	struct dnode_of_data dn;
1512 	struct page *ipage;
1513 	bool locked = false;
1514 	struct extent_info ei;
1515 	int err = 0;
1516 
1517 	/*
1518 	 * we already allocated all the blocks, so we don't need to get
1519 	 * the block addresses when there is no need to fill the page.
1520 	 */
1521 	if (!f2fs_has_inline_data(inode) && !f2fs_encrypted_inode(inode) &&
1522 					len == PAGE_SIZE)
1523 		return 0;
1524 
1525 	if (f2fs_has_inline_data(inode) ||
1526 			(pos & PAGE_MASK) >= i_size_read(inode)) {
1527 		f2fs_lock_op(sbi);
1528 		locked = true;
1529 	}
1530 restart:
1531 	/* check inline_data */
1532 	ipage = get_node_page(sbi, inode->i_ino);
1533 	if (IS_ERR(ipage)) {
1534 		err = PTR_ERR(ipage);
1535 		goto unlock_out;
1536 	}
1537 
1538 	set_new_dnode(&dn, inode, ipage, ipage, 0);
1539 
1540 	if (f2fs_has_inline_data(inode)) {
1541 		if (pos + len <= MAX_INLINE_DATA) {
1542 			read_inline_data(page, ipage);
1543 			set_inode_flag(inode, FI_DATA_EXIST);
1544 			if (inode->i_nlink)
1545 				set_inline_node(ipage);
1546 		} else {
1547 			err = f2fs_convert_inline_page(&dn, page);
1548 			if (err)
1549 				goto out;
1550 			if (dn.data_blkaddr == NULL_ADDR)
1551 				err = f2fs_get_block(&dn, index);
1552 		}
1553 	} else if (locked) {
1554 		err = f2fs_get_block(&dn, index);
1555 	} else {
1556 		if (f2fs_lookup_extent_cache(inode, index, &ei)) {
1557 			dn.data_blkaddr = ei.blk + index - ei.fofs;
1558 		} else {
1559 			/* hole case */
1560 			err = get_dnode_of_data(&dn, index, LOOKUP_NODE);
1561 			if (err || dn.data_blkaddr == NULL_ADDR) {
1562 				f2fs_put_dnode(&dn);
1563 				f2fs_lock_op(sbi);
1564 				locked = true;
1565 				goto restart;
1566 			}
1567 		}
1568 	}
1569 
1570 	/* convert_inline_page can make node_changed */
1571 	*blk_addr = dn.data_blkaddr;
1572 	*node_changed = dn.node_changed;
1573 out:
1574 	f2fs_put_dnode(&dn);
1575 unlock_out:
1576 	if (locked)
1577 		f2fs_unlock_op(sbi);
1578 	return err;
1579 }
1580 
1581 static int f2fs_write_begin(struct file *file, struct address_space *mapping,
1582 		loff_t pos, unsigned len, unsigned flags,
1583 		struct page **pagep, void **fsdata)
1584 {
1585 	struct inode *inode = mapping->host;
1586 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1587 	struct page *page = NULL;
1588 	pgoff_t index = ((unsigned long long) pos) >> PAGE_SHIFT;
1589 	bool need_balance = false;
1590 	block_t blkaddr = NULL_ADDR;
1591 	int err = 0;
1592 
1593 	trace_f2fs_write_begin(inode, pos, len, flags);
1594 
1595 	/*
1596 	 * We should check this at this moment to avoid deadlock on inode page
1597 	 * and #0 page. The locking rule for inline_data conversion should be:
1598 	 * lock_page(page #0) -> lock_page(inode_page)
1599 	 */
1600 	if (index != 0) {
1601 		err = f2fs_convert_inline_inode(inode);
1602 		if (err)
1603 			goto fail;
1604 	}
1605 repeat:
1606 	page = grab_cache_page_write_begin(mapping, index, flags);
1607 	if (!page) {
1608 		err = -ENOMEM;
1609 		goto fail;
1610 	}
1611 
1612 	*pagep = page;
1613 
1614 	err = prepare_write_begin(sbi, page, pos, len,
1615 					&blkaddr, &need_balance);
1616 	if (err)
1617 		goto fail;
1618 
1619 	if (need_balance && has_not_enough_free_secs(sbi, 0)) {
1620 		unlock_page(page);
1621 		f2fs_balance_fs(sbi, true);
1622 		lock_page(page);
1623 		if (page->mapping != mapping) {
1624 			/* The page got truncated from under us */
1625 			f2fs_put_page(page, 1);
1626 			goto repeat;
1627 		}
1628 	}
1629 
1630 	f2fs_wait_on_page_writeback(page, DATA, false);
1631 
1632 	/* wait for GCed encrypted page writeback */
1633 	if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode))
1634 		f2fs_wait_on_encrypted_page_writeback(sbi, blkaddr);
1635 
1636 	if (len == PAGE_SIZE)
1637 		goto out_update;
1638 	if (PageUptodate(page))
1639 		goto out_clear;
1640 
1641 	if ((pos & PAGE_MASK) >= i_size_read(inode)) {
1642 		unsigned start = pos & (PAGE_SIZE - 1);
1643 		unsigned end = start + len;
1644 
1645 		/* Reading beyond i_size is simple: memset to zero */
1646 		zero_user_segments(page, 0, start, end, PAGE_SIZE);
1647 		goto out_update;
1648 	}
1649 
1650 	if (blkaddr == NEW_ADDR) {
1651 		zero_user_segment(page, 0, PAGE_SIZE);
1652 	} else {
1653 		struct bio *bio;
1654 
1655 		bio = f2fs_grab_bio(inode, blkaddr, 1);
1656 		if (IS_ERR(bio)) {
1657 			err = PTR_ERR(bio);
1658 			goto fail;
1659 		}
1660 		bio_set_op_attrs(bio, REQ_OP_READ, READ_SYNC);
1661 		if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
1662 			bio_put(bio);
1663 			err = -EFAULT;
1664 			goto fail;
1665 		}
1666 
1667 		__submit_bio(sbi, bio, DATA);
1668 
1669 		lock_page(page);
1670 		if (unlikely(page->mapping != mapping)) {
1671 			f2fs_put_page(page, 1);
1672 			goto repeat;
1673 		}
1674 		if (unlikely(!PageUptodate(page))) {
1675 			err = -EIO;
1676 			goto fail;
1677 		}
1678 	}
1679 out_update:
1680 	if (!PageUptodate(page))
1681 		SetPageUptodate(page);
1682 out_clear:
1683 	clear_cold_data(page);
1684 	return 0;
1685 
1686 fail:
1687 	f2fs_put_page(page, 1);
1688 	f2fs_write_failed(mapping, pos + len);
1689 	return err;
1690 }
1691 
1692 static int f2fs_write_end(struct file *file,
1693 			struct address_space *mapping,
1694 			loff_t pos, unsigned len, unsigned copied,
1695 			struct page *page, void *fsdata)
1696 {
1697 	struct inode *inode = page->mapping->host;
1698 
1699 	trace_f2fs_write_end(inode, pos, len, copied);
1700 
1701 	set_page_dirty(page);
1702 	f2fs_put_page(page, 1);
1703 
1704 	if (pos + copied > i_size_read(inode))
1705 		f2fs_i_size_write(inode, pos + copied);
1706 
1707 	f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
1708 	return copied;
1709 }
1710 
1711 static int check_direct_IO(struct inode *inode, struct iov_iter *iter,
1712 			   loff_t offset)
1713 {
1714 	unsigned blocksize_mask = inode->i_sb->s_blocksize - 1;
1715 
1716 	if (offset & blocksize_mask)
1717 		return -EINVAL;
1718 
1719 	if (iov_iter_alignment(iter) & blocksize_mask)
1720 		return -EINVAL;
1721 
1722 	return 0;
1723 }
1724 
1725 static ssize_t f2fs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
1726 {
1727 	struct address_space *mapping = iocb->ki_filp->f_mapping;
1728 	struct inode *inode = mapping->host;
1729 	size_t count = iov_iter_count(iter);
1730 	loff_t offset = iocb->ki_pos;
1731 	int rw = iov_iter_rw(iter);
1732 	int err;
1733 
1734 	err = check_direct_IO(inode, iter, offset);
1735 	if (err)
1736 		return err;
1737 
1738 	if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode))
1739 		return 0;
1740 	if (test_opt(F2FS_I_SB(inode), LFS))
1741 		return 0;
1742 
1743 	trace_f2fs_direct_IO_enter(inode, offset, count, rw);
1744 
1745 	down_read(&F2FS_I(inode)->dio_rwsem[rw]);
1746 	err = blockdev_direct_IO(iocb, inode, iter, get_data_block_dio);
1747 	up_read(&F2FS_I(inode)->dio_rwsem[rw]);
1748 
1749 	if (rw == WRITE) {
1750 		if (err > 0)
1751 			set_inode_flag(inode, FI_UPDATE_WRITE);
1752 		else if (err < 0)
1753 			f2fs_write_failed(mapping, offset + count);
1754 	}
1755 
1756 	trace_f2fs_direct_IO_exit(inode, offset, count, rw, err);
1757 
1758 	return err;
1759 }
1760 
1761 void f2fs_invalidate_page(struct page *page, unsigned int offset,
1762 							unsigned int length)
1763 {
1764 	struct inode *inode = page->mapping->host;
1765 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1766 
1767 	if (inode->i_ino >= F2FS_ROOT_INO(sbi) &&
1768 		(offset % PAGE_SIZE || length != PAGE_SIZE))
1769 		return;
1770 
1771 	if (PageDirty(page)) {
1772 		if (inode->i_ino == F2FS_META_INO(sbi))
1773 			dec_page_count(sbi, F2FS_DIRTY_META);
1774 		else if (inode->i_ino == F2FS_NODE_INO(sbi))
1775 			dec_page_count(sbi, F2FS_DIRTY_NODES);
1776 		else
1777 			inode_dec_dirty_pages(inode);
1778 	}
1779 
1780 	/* This is atomic written page, keep Private */
1781 	if (IS_ATOMIC_WRITTEN_PAGE(page))
1782 		return;
1783 
1784 	set_page_private(page, 0);
1785 	ClearPagePrivate(page);
1786 }
1787 
1788 int f2fs_release_page(struct page *page, gfp_t wait)
1789 {
1790 	/* If this is dirty page, keep PagePrivate */
1791 	if (PageDirty(page))
1792 		return 0;
1793 
1794 	/* This is atomic written page, keep Private */
1795 	if (IS_ATOMIC_WRITTEN_PAGE(page))
1796 		return 0;
1797 
1798 	set_page_private(page, 0);
1799 	ClearPagePrivate(page);
1800 	return 1;
1801 }
1802 
1803 /*
1804  * This was copied from __set_page_dirty_buffers which gives higher performance
1805  * in very high speed storages. (e.g., pmem)
1806  */
1807 void f2fs_set_page_dirty_nobuffers(struct page *page)
1808 {
1809 	struct address_space *mapping = page->mapping;
1810 	unsigned long flags;
1811 
1812 	if (unlikely(!mapping))
1813 		return;
1814 
1815 	spin_lock(&mapping->private_lock);
1816 	lock_page_memcg(page);
1817 	SetPageDirty(page);
1818 	spin_unlock(&mapping->private_lock);
1819 
1820 	spin_lock_irqsave(&mapping->tree_lock, flags);
1821 	WARN_ON_ONCE(!PageUptodate(page));
1822 	account_page_dirtied(page, mapping);
1823 	radix_tree_tag_set(&mapping->page_tree,
1824 			page_index(page), PAGECACHE_TAG_DIRTY);
1825 	spin_unlock_irqrestore(&mapping->tree_lock, flags);
1826 	unlock_page_memcg(page);
1827 
1828 	__mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
1829 	return;
1830 }
1831 
1832 static int f2fs_set_data_page_dirty(struct page *page)
1833 {
1834 	struct address_space *mapping = page->mapping;
1835 	struct inode *inode = mapping->host;
1836 
1837 	trace_f2fs_set_page_dirty(page, DATA);
1838 
1839 	if (!PageUptodate(page))
1840 		SetPageUptodate(page);
1841 
1842 	if (f2fs_is_atomic_file(inode)) {
1843 		if (!IS_ATOMIC_WRITTEN_PAGE(page)) {
1844 			register_inmem_page(inode, page);
1845 			return 1;
1846 		}
1847 		/*
1848 		 * Previously, this page has been registered, we just
1849 		 * return here.
1850 		 */
1851 		return 0;
1852 	}
1853 
1854 	if (!PageDirty(page)) {
1855 		f2fs_set_page_dirty_nobuffers(page);
1856 		update_dirty_page(inode, page);
1857 		return 1;
1858 	}
1859 	return 0;
1860 }
1861 
1862 static sector_t f2fs_bmap(struct address_space *mapping, sector_t block)
1863 {
1864 	struct inode *inode = mapping->host;
1865 
1866 	if (f2fs_has_inline_data(inode))
1867 		return 0;
1868 
1869 	/* make sure allocating whole blocks */
1870 	if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
1871 		filemap_write_and_wait(mapping);
1872 
1873 	return generic_block_bmap(mapping, block, get_data_block_bmap);
1874 }
1875 
1876 const struct address_space_operations f2fs_dblock_aops = {
1877 	.readpage	= f2fs_read_data_page,
1878 	.readpages	= f2fs_read_data_pages,
1879 	.writepage	= f2fs_write_data_page,
1880 	.writepages	= f2fs_write_data_pages,
1881 	.write_begin	= f2fs_write_begin,
1882 	.write_end	= f2fs_write_end,
1883 	.set_page_dirty	= f2fs_set_data_page_dirty,
1884 	.invalidatepage	= f2fs_invalidate_page,
1885 	.releasepage	= f2fs_release_page,
1886 	.direct_IO	= f2fs_direct_IO,
1887 	.bmap		= f2fs_bmap,
1888 };
1889