From ef7cdac101602844a4179f7d2d9e26bd20a0edf9 Mon Sep 17 00:00:00 2001 From: Liu Bo Date: Thu, 13 Apr 2017 18:11:48 -0700 Subject: [PATCH] Btrfs: skip checksum verification if IO error occurs Currently dio read also goes to verify checksum if -EIO has been returned, although it usually fails on checksum, it's not necessary at all, we could directly check if there is another copy to read. And with this, the behavior of dio read is now consistent with that of buffered read. Signed-off-by: Liu Bo Reviewed-by: David Sterba [ use bool for uptodate ] Signed-off-by: David Sterba --- fs/btrfs/inode.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 147bafdb8628..b74a6d23a0fe 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -8180,6 +8180,7 @@ static int __btrfs_subio_endio_read(struct inode *inode, int nr_sectors; unsigned int pgoff; int csum_pos; + bool uptodate = (err == 0); int ret; fs_info = BTRFS_I(inode)->root->fs_info; @@ -8195,12 +8196,13 @@ static int __btrfs_subio_endio_read(struct inode *inode, pgoff = bvec.bv_offset; next_block: - csum_pos = BTRFS_BYTES_TO_BLKS(fs_info, offset); - ret = __readpage_endio_check(inode, io_bio, csum_pos, - bvec.bv_page, pgoff, start, - sectorsize); - if (likely(!ret)) - goto next; + if (uptodate) { + csum_pos = BTRFS_BYTES_TO_BLKS(fs_info, offset); + ret = __readpage_endio_check(inode, io_bio, csum_pos, + bvec.bv_page, pgoff, start, sectorsize); + if (likely(!ret)) + goto next; + } try_again: done.uptodate = 0; done.start = start; -- 2.20.1