[PATCH 2/2] block: allow empty cmdline partition set

["Michał Mirosław" <mirq-linux@rere.qmqm.pl>]

Make no-partitions setting valid. This makes it possible to prevent
kernel from trying to read partition table from a device.

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
---
 Documentation/block/cmdline-partition.rst | 2 +-
 block/cmdline-parser.c                    | 8 +++-----
 2 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/Documentation/block/cmdline-partition.rst b/Documentation/block/cmdline-partition.rst
index 530bedff548a..a5ccacee982f 100644
--- a/Documentation/block/cmdline-partition.rst
+++ b/Documentation/block/cmdline-partition.rst
@@ -13,7 +13,7 @@ Users can easily change the partition.
 The format for the command line is just like mtdparts:
 
 blkdevparts=<blkdev-def>[;<blkdev-def>]
-  <blkdev-def> := <blkdev-id>:<partdef>[,<partdef>]
+  <blkdev-def> := <blkdev-id>:[<partdef>[,<partdef>]]
     <partdef> := <size>[@<offset>](part-name)
 
 <blkdev-id>
diff --git a/block/cmdline-parser.c b/block/cmdline-parser.c
index f2a14571882b..bc63e46e7bfc 100644
--- a/block/cmdline-parser.c
+++ b/block/cmdline-parser.c
@@ -133,11 +133,9 @@ static int parse_parts(struct cmdline_parts **parts, const char *bdevdef)
 		next_subpart = &(*next_subpart)->next_subpart;
 	}
 
-	if (!newparts->subpart) {
-		pr_warn("cmdline partition has no valid partition.");
-		ret = -EINVAL;
-		goto fail;
-	}
+	if (!newparts->subpart)
+		pr_warn("%s: cmdline partition has no valid partitions.",
+			newparts->name);
 
 	*parts = newparts;
 
-- 
2.20.1