From: Jason Yan yanaijie@huawei.com
commit a89afe58f1a74aac768a5eb77af95ef4ee15beaa upstream.
If the last bio returned is not dio->bio, the status of the bio will not assigned to dio->bio if it is error. This will cause the whole IO status wrong.
ksoftirqd/21-117 [021] ..s. 4017.966090: 8,0 C N 4883648 [0] <idle>-0 [018] ..s. 4017.970888: 8,0 C WS 4924800 + 1024 [0] <idle>-0 [018] ..s. 4017.970909: 8,0 D WS 4935424 + 1024 [<idle>] <idle>-0 [018] ..s. 4017.970924: 8,0 D WS 4936448 + 321 [<idle>] ksoftirqd/21-117 [021] ..s. 4017.995033: 8,0 C R 4883648 + 336 [65475] ksoftirqd/21-117 [021] d.s. 4018.001988: myprobe1: (blkdev_bio_end_io+0x0/0x168) bi_status=7 ksoftirqd/21-117 [021] d.s. 4018.001992: myprobe: (aio_complete_rw+0x0/0x148) x0=0xffff802f2595ad80 res=0x12a000 res2=0x0
We always have to assign bio->bi_status to dio->bio.bi_status because we will only check dio->bio.bi_status when we return the whole IO to the upper layer.
Fixes: 542ff7bf18c6 ("block: new direct I/O implementation") Cc: stable@vger.kernel.org Cc: Christoph Hellwig hch@lst.de Cc: Jens Axboe axboe@kernel.dk Reviewed-by: Ming Lei ming.lei@redhat.com Signed-off-by: Jason Yan yanaijie@huawei.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- fs/block_dev.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
--- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -298,10 +298,10 @@ static void blkdev_bio_end_io(struct bio struct blkdev_dio *dio = bio->bi_private; bool should_dirty = dio->should_dirty;
- if (dio->multi_bio && !atomic_dec_and_test(&dio->ref)) { - if (bio->bi_status && !dio->bio.bi_status) - dio->bio.bi_status = bio->bi_status; - } else { + if (bio->bi_status && !dio->bio.bi_status) + dio->bio.bi_status = bio->bi_status; + + if (!dio->multi_bio || atomic_dec_and_test(&dio->ref)) { if (!dio->is_sync) { struct kiocb *iocb = dio->iocb; ssize_t ret;