ext4: make __ext4_get_inode_loc plug

Add a blk_plug to prevent the inode table readahead from being
submitted as small I/O requests.

Signed-off-by: zhangjs <zachary@baishancloud.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index ed1d8f9..11d7c2e 100644 (file)
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4570,6 +4570,7 @@ static int __ext4_get_inode_loc(struct inode *inode,
        struct buffer_head      *bh;
        struct super_block      *sb = inode->i_sb;
        ext4_fsblk_t            block;
+       struct blk_plug         plug;
        int                     inodes_per_block, inode_offset;
 
        iloc->bh = NULL;
@@ -4658,6 +4659,7 @@ make_io:
                 * If we need to do any I/O, try to pre-readahead extra
                 * blocks from the inode table.
                 */
+               blk_start_plug(&plug);
                if (EXT4_SB(sb)->s_inode_readahead_blks) {
                        ext4_fsblk_t b, end, table;
                        unsigned num;
@@ -4688,6 +4690,7 @@ make_io:
                get_bh(bh);
                bh->b_end_io = end_buffer_read_sync;
                submit_bh(REQ_OP_READ, REQ_META | REQ_PRIO, bh);
+               blk_finish_plug(&plug);
                wait_on_buffer(bh);
                if (!buffer_uptodate(bh)) {
                        EXT4_ERROR_INODE_BLOCK(inode, block,