Linux 4.19.35

[thirdparty/kernel/stable-queue.git] / releases / 4.19.35 / block-fix-the-return-errno-for-direct-io.patch

diff --git a/releases/4.19.35/block-fix-the-return-errno-for-direct-io.patch b/releases/4.19.35/block-fix-the-return-errno-for-direct-io.patch
new file mode 100644 (file)
index 0000000..2ee069a
--- /dev/null
+++ b/releases/4.19.35/block-fix-the-return-errno-for-direct-io.patch
@@ -0,0 +1,55 @@
+From a89afe58f1a74aac768a5eb77af95ef4ee15beaa Mon Sep 17 00:00:00 2001
+From: Jason Yan <yanaijie@huawei.com>
+Date: Fri, 12 Apr 2019 10:09:16 +0800
+Subject: block: fix the return errno for direct IO
+
+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
+@@ -296,10 +296,10 @@ 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;