From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51922) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1d8Vai-0007uQ-4F for qemu-devel@nongnu.org; Wed, 10 May 2017 13:40:01 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1d8Vah-00016R-A2 for qemu-devel@nongnu.org; Wed, 10 May 2017 13:40:00 -0400 From: John Snow Date: Wed, 10 May 2017 13:39:45 -0400 Message-Id: <20170510173945.11819-1-jsnow@redhat.com> Subject: [Qemu-devel] [PATCH] blockdev: use drained_begin/end for qmp_block_resize List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-block@nongnu.org Cc: kwolf@redhat.com, qemu-devel@nongnu.org, qemu-stable@nongnu.org, stefanha@redhat.com, pbonzini@redhat.com, mreitz@redhat.com, John Snow Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1447551 If one tries to issue a block_resize while a guest is busy accessing the disk, it is possible that qemu may deadlock when invoking aio_poll from both the main loop and the iothread. Replace another instance of bdrv_drain_all that doesn't quite belong. Suggested-by: Paolo Bonzini Signed-off-by: John Snow --- blockdev.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/blockdev.c b/blockdev.c index 0b38c3d..9ff06f3 100644 --- a/blockdev.c +++ b/blockdev.c @@ -2923,10 +2923,9 @@ void qmp_block_resize(bool has_device, const char *device, goto out; } - /* complete all in-flight operations before resizing the device */ - bdrv_drain_all(); - + bdrv_drained_begin(bs); ret = blk_truncate(blk, size, errp); + bdrv_drained_end(bs); out: blk_unref(blk); -- 2.9.3