[qemu-xen stable-4.13] block/nfs: tear down aio before nfs_close

[patchbot@xxxxxxx]

commit 0694c489cd240620fee5675e8d24c7ce02d1d67d
Author:     Peter Lieven <pl@xxxxxxx>
AuthorDate: Tue Sep 10 17:41:09 2019 +0200
Commit:     Michael Roth <mdroth@xxxxxxxxxxxxxxxxxx>
CommitDate: Mon Oct 28 00:03:19 2019 -0500

    block/nfs: tear down aio before nfs_close
    
    nfs_close is a sync call from libnfs and has its own event
    handler polling on the nfs FD. Avoid that both QEMU and libnfs
    are intefering here.
    
    CC: qemu-stable@xxxxxxxxxx
    Signed-off-by: Peter Lieven <pl@xxxxxxx>
    Signed-off-by: Kevin Wolf <kwolf@xxxxxxxxxx>
    (cherry picked from commit 601dc6559725f7a614b6f893611e17ff0908e914)
    Signed-off-by: Michael Roth <mdroth@xxxxxxxxxxxxxxxxxx>
---
 block/nfs.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/block/nfs.c b/block/nfs.c
index d93241b3bb..2b7a078241 100644
--- a/block/nfs.c
+++ b/block/nfs.c
@@ -390,12 +390,14 @@ static void nfs_attach_aio_context(BlockDriverState *bs,
 static void nfs_client_close(NFSClient *client)
 {
     if (client->context) {
+        qemu_mutex_lock(&client->mutex);
+        aio_set_fd_handler(client->aio_context, nfs_get_fd(client->context),
+                           false, NULL, NULL, NULL, NULL);
+        qemu_mutex_unlock(&client->mutex);
         if (client->fh) {
             nfs_close(client->context, client->fh);
             client->fh = NULL;
         }
-        aio_set_fd_handler(client->aio_context, nfs_get_fd(client->context),
-                           false, NULL, NULL, NULL, NULL);
         nfs_destroy_context(client->context);
         client->context = NULL;
     }
--
generated by git-patchbot for /home/xen/git/qemu-xen.git#stable-4.13