commit 9b2aa84f87f5b95cb0295dcae38fbfbf115df2be
author Alberto Garcia <berto@igalia.com> Wed Apr 08 12:29:18 2015 +0300
committer Kevin Wolf <kwolf@redhat.com> Tue Apr 28 15:36:09 2015 +0200
tree fb2762247eacc84b4d217a126aeb6239d7614207
parent ec683d604069dcdaaa516789274bc0cdc14e5247

block: add bdrv_get_device_or_node_name()

This function gets the device name associated with a BlockDriverState,
or its node name if the device name is empty.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 4fa30aa8d61d9052ce266fd5429a59a14e941255.1428485266.git.berto@igalia.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block.c

diff --git a/block.c b/block.c
index d13b2e7..cc8010e 100644
--- a/block.c
+++ b/block.c
@@ -3980,6 +3980,15 @@
     return bs->blk ? blk_name(bs->blk) : "";
 }
 
+/* This can be used to identify nodes that might not have a device
+ * name associated. Since node and device names live in the same
+ * namespace, the result is unambiguous. The exception is if both are
+ * absent, then this returns an empty (non-null) string. */
+const char *bdrv_get_device_or_node_name(const BlockDriverState *bs)
+{
+    return bs->blk ? blk_name(bs->blk) : bs->node_name;
+}
+
 int bdrv_get_flags(BlockDriverState *bs)
 {
     return bs->open_flags;

block/quorum.c

diff --git a/block/quorum.c b/block/quorum.c
index 437b122..f91ef75 100644
--- a/block/quorum.c
+++ b/block/quorum.c
@@ -226,10 +226,7 @@
 
 static void quorum_report_failure(QuorumAIOCB *acb)
 {
-    const char *reference = bdrv_get_device_name(acb->common.bs)[0] ?
-                            bdrv_get_device_name(acb->common.bs) :
-                            acb->common.bs->node_name;
-
+    const char *reference = bdrv_get_device_or_node_name(acb->common.bs);
     qapi_event_send_quorum_failure(reference, acb->sector_num,
                                    acb->nb_sectors, &error_abort);
 }

include/block/block.h

diff --git a/include/block/block.h b/include/block/block.h
index 4c57d63..b285e0d 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -398,6 +398,7 @@
                          void *opaque);
 const char *bdrv_get_node_name(const BlockDriverState *bs);
 const char *bdrv_get_device_name(const BlockDriverState *bs);
+const char *bdrv_get_device_or_node_name(const BlockDriverState *bs);
 int bdrv_get_flags(BlockDriverState *bs);
 int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num,
                           const uint8_t *buf, int nb_sectors);