4 * Copyright (c) 2012 Samsung Electronics Co., Ltd.
5 * http://www.samsung.com/
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.
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/blkdev.h>
18 #include <linux/bio.h>
19 #include <linux/prefetch.h>
24 #include <trace/events/f2fs.h>
27 * Lock ordering for the change of data block address:
30 * update block addresses in the node page
32 static void __set_data_blkaddr(struct dnode_of_data *dn, block_t new_addr)
36 struct page *node_page = dn->node_page;
37 unsigned int ofs_in_node = dn->ofs_in_node;
39 wait_on_page_writeback(node_page);
41 rn = (struct f2fs_node *)page_address(node_page);
43 /* Get physical address of data block */
44 addr_array = blkaddr_in_node(rn);
45 addr_array[ofs_in_node] = cpu_to_le32(new_addr);
46 set_page_dirty(node_page);
49 int reserve_new_block(struct dnode_of_data *dn)
51 struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb);
53 if (is_inode_flag_set(F2FS_I(dn->inode), FI_NO_ALLOC))
55 if (!inc_valid_block_count(sbi, dn->inode, 1))
58 __set_data_blkaddr(dn, NEW_ADDR);
59 dn->data_blkaddr = NEW_ADDR;
64 static int check_extent_cache(struct inode *inode, pgoff_t pgofs,
65 struct buffer_head *bh_result)
67 struct f2fs_inode_info *fi = F2FS_I(inode);
68 struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
69 pgoff_t start_fofs, end_fofs;
70 block_t start_blkaddr;
72 read_lock(&fi->ext.ext_lock);
73 if (fi->ext.len == 0) {
74 read_unlock(&fi->ext.ext_lock);
79 start_fofs = fi->ext.fofs;
80 end_fofs = fi->ext.fofs + fi->ext.len - 1;
81 start_blkaddr = fi->ext.blk_addr;
83 if (pgofs >= start_fofs && pgofs <= end_fofs) {
84 unsigned int blkbits = inode->i_sb->s_blocksize_bits;
87 clear_buffer_new(bh_result);
88 map_bh(bh_result, inode->i_sb,
89 start_blkaddr + pgofs - start_fofs);
90 count = end_fofs - pgofs + 1;
91 if (count < (UINT_MAX >> blkbits))
92 bh_result->b_size = (count << blkbits);
94 bh_result->b_size = UINT_MAX;
97 read_unlock(&fi->ext.ext_lock);
100 read_unlock(&fi->ext.ext_lock);
104 void update_extent_cache(block_t blk_addr, struct dnode_of_data *dn)
106 struct f2fs_inode_info *fi = F2FS_I(dn->inode);
107 pgoff_t fofs, start_fofs, end_fofs;
108 block_t start_blkaddr, end_blkaddr;
110 BUG_ON(blk_addr == NEW_ADDR);
111 fofs = start_bidx_of_node(ofs_of_node(dn->node_page)) + dn->ofs_in_node;
113 /* Update the page address in the parent node */
114 __set_data_blkaddr(dn, blk_addr);
116 write_lock(&fi->ext.ext_lock);
118 start_fofs = fi->ext.fofs;
119 end_fofs = fi->ext.fofs + fi->ext.len - 1;
120 start_blkaddr = fi->ext.blk_addr;
121 end_blkaddr = fi->ext.blk_addr + fi->ext.len - 1;
123 /* Drop and initialize the matched extent */
124 if (fi->ext.len == 1 && fofs == start_fofs)
128 if (fi->ext.len == 0) {
129 if (blk_addr != NULL_ADDR) {
131 fi->ext.blk_addr = blk_addr;
138 if (fofs == start_fofs - 1 && blk_addr == start_blkaddr - 1) {
146 if (fofs == end_fofs + 1 && blk_addr == end_blkaddr + 1) {
151 /* Split the existing extent */
152 if (fi->ext.len > 1 &&
153 fofs >= start_fofs && fofs <= end_fofs) {
154 if ((end_fofs - fofs) < (fi->ext.len >> 1)) {
155 fi->ext.len = fofs - start_fofs;
157 fi->ext.fofs = fofs + 1;
158 fi->ext.blk_addr = start_blkaddr +
159 fofs - start_fofs + 1;
160 fi->ext.len -= fofs - start_fofs + 1;
164 write_unlock(&fi->ext.ext_lock);
168 write_unlock(&fi->ext.ext_lock);
173 struct page *find_data_page(struct inode *inode, pgoff_t index)
175 struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
176 struct address_space *mapping = inode->i_mapping;
177 struct dnode_of_data dn;
181 page = find_get_page(mapping, index);
182 if (page && PageUptodate(page))
184 f2fs_put_page(page, 0);
186 set_new_dnode(&dn, inode, NULL, NULL, 0);
187 err = get_dnode_of_data(&dn, index, LOOKUP_NODE);
192 if (dn.data_blkaddr == NULL_ADDR)
193 return ERR_PTR(-ENOENT);
195 /* By fallocate(), there is no cached page, but with NEW_ADDR */
196 if (dn.data_blkaddr == NEW_ADDR)
197 return ERR_PTR(-EINVAL);
199 page = grab_cache_page(mapping, index);
201 return ERR_PTR(-ENOMEM);
203 if (PageUptodate(page)) {
208 err = f2fs_readpage(sbi, page, dn.data_blkaddr, READ_SYNC);
209 wait_on_page_locked(page);
210 if (!PageUptodate(page)) {
211 f2fs_put_page(page, 0);
212 return ERR_PTR(-EIO);
218 * If it tries to access a hole, return an error.
219 * Because, the callers, functions in dir.c and GC, should be able to know
220 * whether this page exists or not.
222 struct page *get_lock_data_page(struct inode *inode, pgoff_t index)
224 struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
225 struct address_space *mapping = inode->i_mapping;
226 struct dnode_of_data dn;
230 set_new_dnode(&dn, inode, NULL, NULL, 0);
231 err = get_dnode_of_data(&dn, index, LOOKUP_NODE);
236 if (dn.data_blkaddr == NULL_ADDR)
237 return ERR_PTR(-ENOENT);
239 page = grab_cache_page(mapping, index);
241 return ERR_PTR(-ENOMEM);
243 if (PageUptodate(page))
246 BUG_ON(dn.data_blkaddr == NEW_ADDR);
247 BUG_ON(dn.data_blkaddr == NULL_ADDR);
249 err = f2fs_readpage(sbi, page, dn.data_blkaddr, READ_SYNC);
254 if (!PageUptodate(page)) {
255 f2fs_put_page(page, 1);
256 return ERR_PTR(-EIO);
262 * Caller ensures that this data page is never allocated.
263 * A new zero-filled data page is allocated in the page cache.
265 * Also, caller should grab and release a mutex by calling mutex_lock_op() and
268 struct page *get_new_data_page(struct inode *inode, pgoff_t index,
271 struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
272 struct address_space *mapping = inode->i_mapping;
274 struct dnode_of_data dn;
277 set_new_dnode(&dn, inode, NULL, NULL, 0);
278 err = get_dnode_of_data(&dn, index, ALLOC_NODE);
282 if (dn.data_blkaddr == NULL_ADDR) {
283 if (reserve_new_block(&dn)) {
285 return ERR_PTR(-ENOSPC);
290 page = grab_cache_page(mapping, index);
292 return ERR_PTR(-ENOMEM);
294 if (PageUptodate(page))
297 if (dn.data_blkaddr == NEW_ADDR) {
298 zero_user_segment(page, 0, PAGE_CACHE_SIZE);
299 SetPageUptodate(page);
301 err = f2fs_readpage(sbi, page, dn.data_blkaddr, READ_SYNC);
305 if (!PageUptodate(page)) {
306 f2fs_put_page(page, 1);
307 return ERR_PTR(-EIO);
312 i_size_read(inode) < ((index + 1) << PAGE_CACHE_SHIFT)) {
313 i_size_write(inode, ((index + 1) << PAGE_CACHE_SHIFT));
314 mark_inode_dirty_sync(inode);
319 static void read_end_io(struct bio *bio, int err)
321 const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
322 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
325 struct page *page = bvec->bv_page;
327 if (--bvec >= bio->bi_io_vec)
328 prefetchw(&bvec->bv_page->flags);
331 SetPageUptodate(page);
333 ClearPageUptodate(page);
337 } while (bvec >= bio->bi_io_vec);
338 kfree(bio->bi_private);
343 * Fill the locked page with data located in the block address.
344 * Return unlocked page.
346 int f2fs_readpage(struct f2fs_sb_info *sbi, struct page *page,
347 block_t blk_addr, int type)
349 struct block_device *bdev = sbi->sb->s_bdev;
352 trace_f2fs_readpage(page, blk_addr, type);
354 down_read(&sbi->bio_sem);
356 /* Allocate a new bio */
357 bio = f2fs_bio_alloc(bdev, 1);
359 /* Initialize the bio */
360 bio->bi_sector = SECTOR_FROM_BLOCK(sbi, blk_addr);
361 bio->bi_end_io = read_end_io;
363 if (bio_add_page(bio, page, PAGE_CACHE_SIZE, 0) < PAGE_CACHE_SIZE) {
364 kfree(bio->bi_private);
366 up_read(&sbi->bio_sem);
367 f2fs_put_page(page, 1);
371 submit_bio(type, bio);
372 up_read(&sbi->bio_sem);
377 * This function should be used by the data read flow only where it
378 * does not check the "create" flag that indicates block allocation.
379 * The reason for this special functionality is to exploit VFS readahead
382 static int get_data_block_ro(struct inode *inode, sector_t iblock,
383 struct buffer_head *bh_result, int create)
385 unsigned int blkbits = inode->i_sb->s_blocksize_bits;
386 unsigned maxblocks = bh_result->b_size >> blkbits;
387 struct dnode_of_data dn;
391 /* Get the page offset from the block offset(iblock) */
392 pgofs = (pgoff_t)(iblock >> (PAGE_CACHE_SHIFT - blkbits));
394 if (check_extent_cache(inode, pgofs, bh_result)) {
395 trace_f2fs_get_data_block(inode, iblock, bh_result, 0);
399 /* When reading holes, we need its node page */
400 set_new_dnode(&dn, inode, NULL, NULL, 0);
401 err = get_dnode_of_data(&dn, pgofs, LOOKUP_NODE_RA);
403 trace_f2fs_get_data_block(inode, iblock, bh_result, err);
404 return (err == -ENOENT) ? 0 : err;
407 /* It does not support data allocation */
410 if (dn.data_blkaddr != NEW_ADDR && dn.data_blkaddr != NULL_ADDR) {
412 unsigned int end_offset;
414 end_offset = IS_INODE(dn.node_page) ?
418 clear_buffer_new(bh_result);
420 /* Give more consecutive addresses for the read ahead */
421 for (i = 0; i < end_offset - dn.ofs_in_node; i++)
422 if (((datablock_addr(dn.node_page,
424 != (dn.data_blkaddr + i)) || maxblocks == i)
426 map_bh(bh_result, inode->i_sb, dn.data_blkaddr);
427 bh_result->b_size = (i << blkbits);
430 trace_f2fs_get_data_block(inode, iblock, bh_result, 0);
434 static int f2fs_read_data_page(struct file *file, struct page *page)
436 return mpage_readpage(page, get_data_block_ro);
439 static int f2fs_read_data_pages(struct file *file,
440 struct address_space *mapping,
441 struct list_head *pages, unsigned nr_pages)
443 return mpage_readpages(mapping, pages, nr_pages, get_data_block_ro);
446 int do_write_data_page(struct page *page)
448 struct inode *inode = page->mapping->host;
449 block_t old_blk_addr, new_blk_addr;
450 struct dnode_of_data dn;
453 set_new_dnode(&dn, inode, NULL, NULL, 0);
454 err = get_dnode_of_data(&dn, page->index, LOOKUP_NODE);
458 old_blk_addr = dn.data_blkaddr;
460 /* This page is already truncated */
461 if (old_blk_addr == NULL_ADDR)
464 set_page_writeback(page);
467 * If current allocation needs SSR,
468 * it had better in-place writes for updated data.
470 if (old_blk_addr != NEW_ADDR && !is_cold_data(page) &&
471 need_inplace_update(inode)) {
472 rewrite_data_page(F2FS_SB(inode->i_sb), page,
475 write_data_page(inode, page, &dn,
476 old_blk_addr, &new_blk_addr);
477 update_extent_cache(new_blk_addr, &dn);
484 static int f2fs_write_data_page(struct page *page,
485 struct writeback_control *wbc)
487 struct inode *inode = page->mapping->host;
488 struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
489 loff_t i_size = i_size_read(inode);
490 const pgoff_t end_index = ((unsigned long long) i_size)
493 bool need_balance_fs = false;
496 if (page->index < end_index)
500 * If the offset is out-of-range of file size,
501 * this page does not have to be written to disk.
503 offset = i_size & (PAGE_CACHE_SIZE - 1);
504 if ((page->index >= end_index + 1) || !offset) {
505 if (S_ISDIR(inode->i_mode)) {
506 dec_page_count(sbi, F2FS_DIRTY_DENTS);
507 inode_dec_dirty_dents(inode);
512 zero_user_segment(page, offset, PAGE_CACHE_SIZE);
514 if (sbi->por_doing) {
515 err = AOP_WRITEPAGE_ACTIVATE;
519 /* Dentry blocks are controlled by checkpoint */
520 if (S_ISDIR(inode->i_mode)) {
521 dec_page_count(sbi, F2FS_DIRTY_DENTS);
522 inode_dec_dirty_dents(inode);
523 err = do_write_data_page(page);
525 int ilock = mutex_lock_op(sbi);
526 err = do_write_data_page(page);
527 mutex_unlock_op(sbi, ilock);
528 need_balance_fs = true;
535 if (wbc->for_reclaim)
536 f2fs_submit_bio(sbi, DATA, true);
538 clear_cold_data(page);
542 f2fs_balance_fs(sbi);
546 wbc->pages_skipped++;
547 set_page_dirty(page);
551 #define MAX_DESIRED_PAGES_WP 4096
553 static int __f2fs_writepage(struct page *page, struct writeback_control *wbc,
556 struct address_space *mapping = data;
557 int ret = mapping->a_ops->writepage(page, wbc);
558 mapping_set_error(mapping, ret);
562 static int f2fs_write_data_pages(struct address_space *mapping,
563 struct writeback_control *wbc)
565 struct inode *inode = mapping->host;
566 struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
568 long excess_nrtw = 0, desired_nrtw;
570 /* deal with chardevs and other special file */
571 if (!mapping->a_ops->writepage)
574 if (wbc->nr_to_write < MAX_DESIRED_PAGES_WP) {
575 desired_nrtw = MAX_DESIRED_PAGES_WP;
576 excess_nrtw = desired_nrtw - wbc->nr_to_write;
577 wbc->nr_to_write = desired_nrtw;
580 if (!S_ISDIR(inode->i_mode))
581 mutex_lock(&sbi->writepages);
582 ret = write_cache_pages(mapping, wbc, __f2fs_writepage, mapping);
583 if (!S_ISDIR(inode->i_mode))
584 mutex_unlock(&sbi->writepages);
585 f2fs_submit_bio(sbi, DATA, (wbc->sync_mode == WB_SYNC_ALL));
587 remove_dirty_dir_inode(inode);
589 wbc->nr_to_write -= excess_nrtw;
593 static int f2fs_write_begin(struct file *file, struct address_space *mapping,
594 loff_t pos, unsigned len, unsigned flags,
595 struct page **pagep, void **fsdata)
597 struct inode *inode = mapping->host;
598 struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
600 pgoff_t index = ((unsigned long long) pos) >> PAGE_CACHE_SHIFT;
601 struct dnode_of_data dn;
605 /* for nobh_write_end */
608 f2fs_balance_fs(sbi);
610 page = grab_cache_page_write_begin(mapping, index, flags);
615 ilock = mutex_lock_op(sbi);
617 set_new_dnode(&dn, inode, NULL, NULL, 0);
618 err = get_dnode_of_data(&dn, index, ALLOC_NODE);
622 if (dn.data_blkaddr == NULL_ADDR)
623 err = reserve_new_block(&dn);
629 mutex_unlock_op(sbi, ilock);
631 if ((len == PAGE_CACHE_SIZE) || PageUptodate(page))
634 if ((pos & PAGE_CACHE_MASK) >= i_size_read(inode)) {
635 unsigned start = pos & (PAGE_CACHE_SIZE - 1);
636 unsigned end = start + len;
638 /* Reading beyond i_size is simple: memset to zero */
639 zero_user_segments(page, 0, start, end, PAGE_CACHE_SIZE);
643 if (dn.data_blkaddr == NEW_ADDR) {
644 zero_user_segment(page, 0, PAGE_CACHE_SIZE);
646 err = f2fs_readpage(sbi, page, dn.data_blkaddr, READ_SYNC);
650 if (!PageUptodate(page)) {
651 f2fs_put_page(page, 1);
656 SetPageUptodate(page);
657 clear_cold_data(page);
661 mutex_unlock_op(sbi, ilock);
662 f2fs_put_page(page, 1);
666 static ssize_t f2fs_direct_IO(int rw, struct kiocb *iocb,
667 const struct iovec *iov, loff_t offset, unsigned long nr_segs)
669 struct file *file = iocb->ki_filp;
670 struct inode *inode = file->f_mapping->host;
675 /* Needs synchronization with the cleaner */
676 return blockdev_direct_IO(rw, iocb, inode, iov, offset, nr_segs,
680 static void f2fs_invalidate_data_page(struct page *page, unsigned long offset)
682 struct inode *inode = page->mapping->host;
683 struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
684 if (S_ISDIR(inode->i_mode) && PageDirty(page)) {
685 dec_page_count(sbi, F2FS_DIRTY_DENTS);
686 inode_dec_dirty_dents(inode);
688 ClearPagePrivate(page);
691 static int f2fs_release_data_page(struct page *page, gfp_t wait)
693 ClearPagePrivate(page);
697 static int f2fs_set_data_page_dirty(struct page *page)
699 struct address_space *mapping = page->mapping;
700 struct inode *inode = mapping->host;
702 SetPageUptodate(page);
703 if (!PageDirty(page)) {
704 __set_page_dirty_nobuffers(page);
705 set_dirty_dir_page(inode, page);
711 static sector_t f2fs_bmap(struct address_space *mapping, sector_t block)
713 return generic_block_bmap(mapping, block, get_data_block_ro);
716 const struct address_space_operations f2fs_dblock_aops = {
717 .readpage = f2fs_read_data_page,
718 .readpages = f2fs_read_data_pages,
719 .writepage = f2fs_write_data_page,
720 .writepages = f2fs_write_data_pages,
721 .write_begin = f2fs_write_begin,
722 .write_end = nobh_write_end,
723 .set_page_dirty = f2fs_set_data_page_dirty,
724 .invalidatepage = f2fs_invalidate_data_page,
725 .releasepage = f2fs_release_data_page,
726 .direct_IO = f2fs_direct_IO,