queue-4.19/block-fix-the-return-errno-for-direct-io.patch

   1 From a89afe58f1a74aac768a5eb77af95ef4ee15beaa Mon Sep 17 00:00:00 2001
   2 From: Jason Yan <yanaijie@huawei.com>
   3 Date: Fri, 12 Apr 2019 10:09:16 +0800
   4 Subject: block: fix the return errno for direct IO
   5
   6 From: Jason Yan <yanaijie@huawei.com>
   7
   8 commit a89afe58f1a74aac768a5eb77af95ef4ee15beaa upstream.
   9
  10 If the last bio returned is not dio->bio, the status of the bio will
  11 not assigned to dio->bio if it is error. This will cause the whole IO
  12 status wrong.
  13
  14     ksoftirqd/21-117   [021] ..s.  4017.966090:   8,0    C   N 4883648 [0]
  15           <idle>-0     [018] ..s.  4017.970888:   8,0    C  WS 4924800 + 1024 [0]
  16           <idle>-0     [018] ..s.  4017.970909:   8,0    D  WS 4935424 + 1024 [<idle>]
  17           <idle>-0     [018] ..s.  4017.970924:   8,0    D  WS 4936448 + 321 [<idle>]
  18     ksoftirqd/21-117   [021] ..s.  4017.995033:   8,0    C   R 4883648 + 336 [65475]
  19     ksoftirqd/21-117   [021] d.s.  4018.001988: myprobe1: (blkdev_bio_end_io+0x0/0x168) bi_status=7
  20     ksoftirqd/21-117   [021] d.s.  4018.001992: myprobe: (aio_complete_rw+0x0/0x148) x0=0xffff802f2595ad80 res=0x12a000 res2=0x0
  21
  22 We always have to assign bio->bi_status to dio->bio.bi_status because we
  23 will only check dio->bio.bi_status when we return the whole IO to
  24 the upper layer.
  25
  26 Fixes: 542ff7bf18c6 ("block: new direct I/O implementation")
  27 Cc: stable@vger.kernel.org
  28 Cc: Christoph Hellwig <hch@lst.de>
  29 Cc: Jens Axboe <axboe@kernel.dk>
  30 Reviewed-by: Ming Lei <ming.lei@redhat.com>
  31 Signed-off-by: Jason Yan <yanaijie@huawei.com>
  32 Signed-off-by: Jens Axboe <axboe@kernel.dk>
  33 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  34
  35 ---
  36  fs/block_dev.c |    8 ++++----
  37  1 file changed, 4 insertions(+), 4 deletions(-)
  38
  39 --- a/fs/block_dev.c
  40 +++ b/fs/block_dev.c
  41 @@ -296,10 +296,10 @@ static void blkdev_bio_end_io(struct bio
  42         struct blkdev_dio *dio = bio->bi_private;
  43         bool should_dirty = dio->should_dirty;
  44
  45 -       if (dio->multi_bio && !atomic_dec_and_test(&dio->ref)) {
  46 -               if (bio->bi_status && !dio->bio.bi_status)
  47 -                       dio->bio.bi_status = bio->bi_status;
  48 -       } else {
  49 +       if (bio->bi_status && !dio->bio.bi_status)
  50 +               dio->bio.bi_status = bio->bi_status;
  51 +
  52 +       if (!dio->multi_bio || atomic_dec_and_test(&dio->ref)) {
  53                 if (!dio->is_sync) {
  54                         struct kiocb *iocb = dio->iocb;
  55                         ssize_t ret;