blockdev: add x-blockdev-set-iothread force boolean

When a node is already associated with a BlockBackend the
x-blockdev-set-iothread command refuses to set the IOThread.  This is to
prevent accidentally changing the IOThread when the nodes are in use.

When the nodes are created with -drive they automatically get a
BlockBackend.  In that case we know nothing is using them yet and it's
safe to set the IOThread.  Add a force boolean to override the check.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20171207201320.19284-4-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This commit is contained in:
Stefan Hajnoczi 2017-12-07 20:13:17 +00:00
parent d02d8dde0c
commit 882e9b89af
2 changed files with 11 additions and 6 deletions

View File

@ -4131,7 +4131,7 @@ BlockJobInfoList *qmp_query_block_jobs(Error **errp)
}
void qmp_x_blockdev_set_iothread(const char *node_name, StrOrNull *iothread,
Error **errp)
bool has_force, bool force, Error **errp)
{
AioContext *old_context;
AioContext *new_context;
@ -4143,10 +4143,11 @@ void qmp_x_blockdev_set_iothread(const char *node_name, StrOrNull *iothread,
return;
}
/* If we want to allow more extreme test scenarios this guard could be
* removed. For now it protects against accidents. */
if (bdrv_has_blk(bs)) {
error_setg(errp, "Node %s is in use", node_name);
/* Protects against accidents. */
if (!(has_force && force) && bdrv_has_blk(bs)) {
error_setg(errp, "Node %s is associated with a BlockBackend and could "
"be in use (use force=true to override this check)",
node_name);
return;
}

View File

@ -3962,6 +3962,9 @@
#
# @iothread: the name of the IOThread object or null for the main loop
#
# @force: true if the node and its children should be moved when a BlockBackend
# is already attached
#
# Note: this command is experimental and intended for test cases that need
# control over IOThreads only.
#
@ -3984,4 +3987,5 @@
##
{ 'command': 'x-blockdev-set-iothread',
'data' : { 'node-name': 'str',
'iothread': 'StrOrNull' } }
'iothread': 'StrOrNull',
'*force': 'bool' } }