From e2e59414aae2c8036dfaa57cf6a578e1694945e8 Mon Sep 17 00:00:00 2001 From: Jaegeuk Kim Date: Thu, 21 Jun 2018 11:29:43 -0700 Subject: [PATCH] f2fs: assign REQ_RAHEAD to bio for ->readpages As Jens reported, we'd better assign REQ_RAHEAD to bio by the fact that ->readpages is called only from read-ahead. In Documentation/filesystems/vfs.txt, readpages: called by the VM to read pages associated with the address_space object. This is essentially just a vector version of readpage. Instead of just one page, several pages are requested. readpages is only used for read-ahead, so read errors are ignored. If anything goes wrong, feel free to give up. Signed-off-by: Jens Axboe Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim --- fs/f2fs/data.c | 20 +++++++++++++------- 1 file changed, 13 insertions(+), 7 deletions(-) diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index 5e53d210e222..b6a90c853221 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -534,7 +534,7 @@ out: } static struct bio *f2fs_grab_read_bio(struct inode *inode, block_t blkaddr, - unsigned nr_pages) + unsigned nr_pages, unsigned op_flag) { struct f2fs_sb_info *sbi = F2FS_I_SB(inode); struct bio *bio; @@ -546,7 +546,7 @@ static struct bio *f2fs_grab_read_bio(struct inode *inode, block_t blkaddr, return ERR_PTR(-ENOMEM); f2fs_target_device(sbi, blkaddr, bio); bio->bi_end_io = f2fs_read_end_io; - bio_set_op_attrs(bio, REQ_OP_READ, 0); + bio_set_op_attrs(bio, REQ_OP_READ, op_flag); if (f2fs_encrypted_file(inode)) post_read_steps |= 1 << STEP_DECRYPT; @@ -571,7 +571,7 @@ static struct bio *f2fs_grab_read_bio(struct inode *inode, block_t blkaddr, static int f2fs_submit_page_read(struct inode *inode, struct page *page, block_t blkaddr) { - struct bio *bio = f2fs_grab_read_bio(inode, blkaddr, 1); + struct bio *bio = f2fs_grab_read_bio(inode, blkaddr, 1, 0); if (IS_ERR(bio)) return PTR_ERR(bio); @@ -1421,10 +1421,15 @@ out: /* * This function was originally taken from fs/mpage.c, and customized for f2fs. * Major change was from block_size == page_size in f2fs by default. + * + * Note that the aops->readpages() function is ONLY used for read-ahead. If + * this function ever deviates from doing just read-ahead, it should either + * use ->readpage() or do the necessary surgery to decouple ->readpages() + * from read-ahead. */ static int f2fs_mpage_readpages(struct address_space *mapping, struct list_head *pages, struct page *page, - unsigned nr_pages) + unsigned nr_pages, bool is_readahead) { struct bio *bio = NULL; sector_t last_block_in_bio = 0; @@ -1514,7 +1519,8 @@ submit_and_realloc: bio = NULL; } if (bio == NULL) { - bio = f2fs_grab_read_bio(inode, block_nr, nr_pages); + bio = f2fs_grab_read_bio(inode, block_nr, nr_pages, + is_readahead ? REQ_RAHEAD : 0); if (IS_ERR(bio)) { bio = NULL; goto set_error_page; @@ -1558,7 +1564,7 @@ static int f2fs_read_data_page(struct file *file, struct page *page) if (f2fs_has_inline_data(inode)) ret = f2fs_read_inline_data(inode, page); if (ret == -EAGAIN) - ret = f2fs_mpage_readpages(page->mapping, NULL, page, 1); + ret = f2fs_mpage_readpages(page->mapping, NULL, page, 1, false); return ret; } @@ -1575,7 +1581,7 @@ static int f2fs_read_data_pages(struct file *file, if (f2fs_has_inline_data(inode)) return 0; - return f2fs_mpage_readpages(mapping, pages, NULL, nr_pages); + return f2fs_mpage_readpages(mapping, pages, NULL, nr_pages, true); } static int encrypt_one_page(struct f2fs_io_info *fio) -- 2.11.4.GIT