From: Jens Axboe <axboe@xxxxxxxxx> Subject: ext4: readpages() should submit IO as read-ahead a_ops->readpages() is only ever used for read-ahead. Ensure that we pass this information down to the block layer. Link: http://lkml.kernel.org/r/20180621010725.17813-5-axboe@xxxxxxxxx Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx> Cc: Chris Mason <clm@xxxxxx> Cc: Christoph Hellwig <hch@xxxxxx> Cc: Theodore Ts'o <tytso@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/ext4/ext4.h | 2 +- fs/ext4/inode.c | 5 +++-- fs/ext4/readpage.c | 5 +++-- 3 files changed, 7 insertions(+), 5 deletions(-) --- a/fs/ext4/ext4.h~ext4-readpages-should-submit-io-as-read-ahead +++ a/fs/ext4/ext4.h @@ -3062,7 +3062,7 @@ static inline void ext4_set_de_type(stru /* readpages.c */ extern int ext4_mpage_readpages(struct address_space *mapping, struct list_head *pages, struct page *page, - unsigned nr_pages); + unsigned nr_pages, bool is_readahead); /* symlink.c */ extern const struct inode_operations ext4_encrypted_symlink_inode_operations; --- a/fs/ext4/inode.c~ext4-readpages-should-submit-io-as-read-ahead +++ a/fs/ext4/inode.c @@ -3325,7 +3325,8 @@ static int ext4_readpage(struct file *fi ret = ext4_readpage_inline(inode, page); if (ret == -EAGAIN) - return ext4_mpage_readpages(page->mapping, NULL, page, 1); + return ext4_mpage_readpages(page->mapping, NULL, page, 1, + false); return ret; } @@ -3340,7 +3341,7 @@ ext4_readpages(struct file *file, struct if (ext4_has_inline_data(inode)) return 0; - return ext4_mpage_readpages(mapping, pages, NULL, nr_pages); + return ext4_mpage_readpages(mapping, pages, NULL, nr_pages, true); } static void ext4_invalidatepage(struct page *page, unsigned int offset, --- a/fs/ext4/readpage.c~ext4-readpages-should-submit-io-as-read-ahead +++ a/fs/ext4/readpage.c @@ -98,7 +98,7 @@ static void mpage_end_io(struct bio *bio int ext4_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; @@ -259,7 +259,8 @@ int ext4_mpage_readpages(struct address_ bio->bi_iter.bi_sector = blocks[0] << (blkbits - 9); bio->bi_end_io = mpage_end_io; bio->bi_private = ctx; - bio_set_op_attrs(bio, REQ_OP_READ, 0); + bio_set_op_attrs(bio, REQ_OP_READ, + is_readahead ? REQ_RAHEAD : 0); } length = first_hole << blkbits; _
