Commit c16a8ac3 authored Dec 18, 2017 by Ming Lei Committed by Jens Axboe Jan 06, 2018

btrfs: avoid accessing bvec table directly for a cloned bio

Commit 17347cec(Btrfs: change how we iterate bios in endio)
mentioned that for dio the submitted bio may be fast cloned, we
can't access the bvec table directly for a cloned bio, so use
bio_get_first_bvec() to retrieve the 1st bvec.

Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <jbacik@fb.com>
Cc: David Sterba <dsterba@suse.com>
Cc: linux-btrfs@vger.kernel.org
Cc: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Acked: David Sterba <dsterba@suse.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

parent a0b60d72

fs/btrfs/inode.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -8015,6 +8015,7 @@ static blk_status_t dio_read_error(struct inode inode, struct bio failed_bio,
		int segs;
		int ret;
		blk_status_t status;
		struct bio_vec bvec;

		BUG_ON(bio_op(failed_bio) == REQ_OP_WRITE);

		@@ -8030,8 +8031,9 @@ static blk_status_t dio_read_error(struct inode inode, struct bio failed_bio,
		}

		segs = bio_segments(failed_bio);
		bio_get_first_bvec(failed_bio, &bvec);
		if (segs > 1 \|\|
		(failed_bio->bi_io_vec->bv_len > btrfs_inode_sectorsize(inode)))
		(bvec.bv_len > btrfs_inode_sectorsize(inode)))
		read_mode \|= REQ_FAILFAST_DEV;

		isector = start - btrfs_io_bio(failed_bio)->logical;

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