[Qemu-devel] [PATCH 2/2] block: assert no image modification under BDRV_O_INACTIVE

From: "Denis V. Lunev" <den@openvz.org>
To: qemu-devel@nongnu.org
Cc: "Denis V. Lunev" <den@openvz.org>, Kevin Wolf <kwolf@redhat.com>,
	Max Reitz <mreitz@redhat.com>
Subject: [Qemu-devel] [PATCH 2/2] block: assert no image modification under BDRV_O_INACTIVE
Date: Wed,  5 Apr 2017 18:18:25 +0300	[thread overview]
Message-ID: <1491405505-31620-3-git-send-email-den@openvz.org> (raw)
In-Reply-To: <1491405505-31620-1-git-send-email-den@openvz.org>

As long as BDRV_O_INACTIVE is set, the image file is only opened so we
have a file descriptor for it. We're definitely not supposed to modify
the image, it's still owned by the migration source.

This commit is an addition to 09e0c771 but the assert() is added to
bdrv_truncate().

Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Kevin Wolf <kwolf@redhat.com>
CC: Max Reitz <mreitz@redhat.com>
---
 block.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/block.c b/block.c
index 927ba89..9273741 100644
--- a/block.c
+++ b/block.c
@@ -3279,6 +3279,8 @@ int bdrv_truncate(BdrvChild *child, int64_t offset)
     if (bs->read_only)
         return -EACCES;
 
+    assert(!(bs->open_flags & BDRV_O_INACTIVE));
+
     ret = drv->bdrv_truncate(bs, offset);
     if (ret == 0) {
         ret = refresh_total_sectors(bs, offset >> BDRV_SECTOR_BITS);
-- 
2.7.4
