This is the companion to 'blockdev-add'. It allows deleting a
BlockBackend with its associated BlockDriverState tree, or a
BlockDriverState that is not attached to any backend.
In either case, the command fails if the reference count is greater
than 1 or the BlockDriverState has any parents.
Signed-off-by: Alberto Garcia <be...@igalia.com>
---
blockdev.c | 42 ++++++++++++++++++++++++++++++++++++++++++
qapi/block-core.json | 21 +++++++++++++++++++++
qmp-commands.hx | 36 ++++++++++++++++++++++++++++++++++++
3 files changed, 99 insertions(+)
diff --git a/blockdev.c b/blockdev.c
index 2360c1f..c448a0b 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -3402,6 +3402,48 @@ fail:
qmp_output_visitor_cleanup(ov);
}
+void qmp_blockdev_del(const char *device, Error **errp)
+{
+ AioContext *aio_context;
+ BlockBackend *blk;
+ BlockDriverState *bs;
+
+ blk = blk_by_name(device);
+ if (blk) {
+ bs = blk_bs(blk);
+ aio_context = blk_get_aio_context(blk);
+ } else {
+ bs = bdrv_find_node(device);
+ if (!bs) {
+ error_setg(errp, "Cannot find block device %s", device);
+ return;
+ }
+ blk = bs->blk;
+ aio_context = bdrv_get_aio_context(bs);
+ }
+
+ aio_context_acquire(aio_context);
+
+ if (bs && bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_DRIVE_DEL, errp)) {
+ goto out;
+ }
+
+ if (blk_get_refcnt(blk) > 1 ||
+ (bs && (bs->refcnt > 1 || !QLIST_EMPTY(&bs->parents)))) {
+ error_setg(errp, "Block device %s is being used", device);
+ goto out;
+ }
+
+ if (blk) {
+ blk_unref(blk);
+ } else {
+ bdrv_unref(bs);
+ }
+
+out:
+ aio_context_release(aio_context);
+}
+
BlockJobInfoList *qmp_query_block_jobs(Error **errp)
{
BlockJobInfoList *head = NULL, **p_next = &head;
diff --git a/qapi/block-core.json b/qapi/block-core.json
index 5f12af7..20897eb 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -1877,6 +1877,27 @@
{ 'command': 'blockdev-add', 'data': { 'options': 'BlockdevOptions' } }
##
+# @blockdev-del:
+#
+# Deletes a block device. The selected device can be either a block
+# backend or a graph node.
+#
+# In the former case the backend will be destroyed, along with its
+# inserted medium if there's any.
+#
+# In the latter case the node will be destroyed, along with the
+# backend it is attached to if there's any.
+#
+# The command will fail if the selected block device is still being
+# used.
+#
+# @device: Name of the block backend or the graph node to be deleted.
+#
+# Since: 2.5
+##
+{ 'command': 'blockdev-del', 'data': { 'device': 'str' } }
+
+##
# @blockdev-open-tray:
#
# Opens a block device's tray. If there is a block driver state tree inserted
as
diff --git a/qmp-commands.hx b/qmp-commands.hx
index 4f03d11..b8b133e 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -3921,6 +3921,42 @@ Example (2):
EQMP
{
+ .name = "blockdev-del",
+ .args_type = "device:s",
+ .mhandler.cmd_new = qmp_marshal_blockdev_del,
+ },
+
+SQMP
+blockdev-del
+------------
+Since 2.5
+
+Deletes a block device. The selected device can be either a block
+backend or a graph node.
+
+In the former case the backend will be destroyed, along with its
+inserted medium if there's any.
+
+In the latter case the node will be destroyed, along with the
+backend it is attached to if there's any.
+
+The command will fail if the selected block device is still being
+used.
+
+Arguments:
+
+- "device": Identifier of the block device or graph node name (json-string)
+
+Example:
+
+-> { "execute": "blockdev-del",
+ "arguments": { "device": "virtio0" }
+ }
+<- { "return": {} }
+
+EQMP
+
+ {
.name = "blockdev-open-tray",
.args_type = "device:s,force:b?",
.mhandler.cmd_new = qmp_marshal_blockdev_open_tray,
--
2.6.1
