1 From 0720bbba9f7ebac6f4f0ae7a65cd687ac6f3c452 Mon Sep 17 00:00:00 2001
2 From: John Snow <jsnow@redhat.com>
3 Date: Wed, 10 May 2017 13:39:45 -0400
4 Subject: [PATCH 05/23] blockdev: use drained_begin/end for qmp_block_resize
6 Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1447551
8 If one tries to issue a block_resize while a guest is busy
9 accessing the disk, it is possible that qemu may deadlock
10 when invoking aio_poll from both the main loop and the iothread.
12 Replace another instance of bdrv_drain_all that doesn't
15 Cc: qemu-stable@nongnu.org
16 Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
17 Signed-off-by: John Snow <jsnow@redhat.com>
18 Reviewed-by: Eric Blake <eblake@redhat.com>
19 Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
20 Signed-off-by: Kevin Wolf <kwolf@redhat.com>
23 1 file changed, 2 insertions(+), 3 deletions(-)
25 diff --git a/blockdev.c b/blockdev.c
26 index 1eeffb0571..1dca232781 100644
29 @@ -2929,10 +2929,9 @@ void qmp_block_resize(bool has_device, const char *device,
33 - /* complete all in-flight operations before resizing the device */
36 + bdrv_drained_begin(bs);
37 ret = blk_truncate(blk, size);
38 + bdrv_drained_end(bs);