From 2a32c6e82ed24d837ce7af346ffc93113f0164b5 Mon Sep 17 00:00:00 2001 From: John Snow Date: Mon, 17 Jul 2017 20:34:21 -0400 Subject: [PATCH] blockdev: move BDRV_O_NO_BACKING option forward For both external_snapshot_prepare and qmp_drive_mirror, we eventually append the option BDRV_O_NO_BACKING. However, we generally do so after we create the image. To accommodate image creation wanting to verify that a backing file exists or not, add this option prior to create to override checking the existence of the backing file. This prevents QEMU from trying to re-open a backing file that's already in use (thanks to qcow2 locking). Signed-off-by: John Snow Reviewed-by: Eric Blake Signed-off-by: Kevin Wolf --- blockdev.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/blockdev.c b/blockdev.c index 7f53cc8bb3..6469f161df 100644 --- a/blockdev.c +++ b/blockdev.c @@ -1710,7 +1710,8 @@ static void external_snapshot_prepare(BlkActionState *common, } flags = state->old_bs->open_flags; - flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING | BDRV_O_COPY_ON_READ); + flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_COPY_ON_READ); + flags |= BDRV_O_NO_BACKING; /* create new image w/backing file */ mode = s->has_mode ? s->mode : NEW_IMAGE_MODE_ABSOLUTE_PATHS; @@ -1735,8 +1736,6 @@ static void external_snapshot_prepare(BlkActionState *common, qdict_put_str(options, "node-name", snapshot_node_name); } qdict_put_str(options, "driver", format); - - flags |= BDRV_O_NO_BACKING; } state->new_bs = bdrv_open(new_image_file, snapshot_ref, options, flags, @@ -3548,6 +3547,9 @@ void qmp_drive_mirror(DriveMirror *arg, Error **errp) backing_mode = MIRROR_OPEN_BACKING_CHAIN; } + /* Don't open backing image in create() */ + flags |= BDRV_O_NO_BACKING; + if ((arg->sync == MIRROR_SYNC_MODE_FULL || !source) && arg->mode != NEW_IMAGE_MODE_EXISTING) { @@ -3587,8 +3589,7 @@ void qmp_drive_mirror(DriveMirror *arg, Error **errp) /* Mirroring takes care of copy-on-write using the source's backing * file. */ - target_bs = bdrv_open(arg->target, NULL, options, - flags | BDRV_O_NO_BACKING, errp); + target_bs = bdrv_open(arg->target, NULL, options, flags, errp); if (!target_bs) { goto out; } -- GitLab