From 9d7066090ad7cde8ce74aa2566959fe7789908b9 Mon Sep 17 00:00:00 2001 From: John Snow Date: Tue, 16 May 2017 21:00:41 +0200 Subject: [PATCH 05/27] blockdev: use drained_begin/end for qmp_block_resize RH-Author: John Snow Message-id: <20170516210041.12856-4-jsnow@redhat.com> Patchwork-id: 75196 O-Subject: [RHV-7.4 qemu-kvm-rhev PATCH v2 3/3] blockdev: use drained_begin/end for qmp_block_resize Bugzilla: 1447551 RH-Acked-by: Stefan Hajnoczi RH-Acked-by: Jeffrey Cody RH-Acked-by: Paolo Bonzini 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. Cc: qemu-stable@nongnu.org Suggested-by: Paolo Bonzini Signed-off-by: John Snow Reviewed-by: Eric Blake Reviewed-by: Paolo Bonzini Signed-off-by: Kevin Wolf (cherry picked from commit 698bdfa07d66b5ec218a60229e58eae1dcde00e5) Signed-off-by: John Snow Signed-off-by: Miroslav Rezanina --- blockdev.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/blockdev.c b/blockdev.c index 6a50742..b0894fa 100644 --- a/blockdev.c +++ b/blockdev.c @@ -2972,10 +2972,9 @@ 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); -- 1.8.3.1