[PATCH] xfs_growfs: allow mounted device node as argument

[Eric Sandeen <sandeen@redhat.com>]

Up until:

 b97815a0 xfs_growfs: ensure target path is an active xfs mountpoint

xfs_growfs actually accepted a mounted block device name as the
primary argument, because it could be found in the mount table.

It turns out that Ansible was making use of this undocumented behavior,
and it's trivial to allow it, so put it back in place and document
it this time.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
---

I can clone tests/xfs/289 to do tests of similar permutations for
device names.

diff --git a/growfs/xfs_growfs.c b/growfs/xfs_growfs.c
index 20089d2b..4224c5a0 100644
--- a/growfs/xfs_growfs.c
+++ b/growfs/xfs_growfs.c
@@ -140,6 +140,9 @@ main(int argc, char **argv)
 	}
 
 	fs = fs_table_lookup_mount(rpath);
+	if (!fs)
+		fs = fs_table_lookup_blkdev(rpath);
+
 	if (!fs) {
 		fprintf(stderr, _("%s: %s is not a mounted XFS filesystem\n"),
 			progname, argv[optind]);
diff --git a/man/man8/xfs_growfs.8 b/man/man8/xfs_growfs.8
index 7e6a387c..60a88189 100644
--- a/man/man8/xfs_growfs.8
+++ b/man/man8/xfs_growfs.8
@@ -35,7 +35,12 @@ xfs_growfs \- expand an XFS filesystem
 .B \-R
 .I size
 ]
+[
 .I mount-point
+|
+.I block-device
+]
+
 .br
 .B xfs_growfs \-V
 .SH DESCRIPTION
@@ -45,7 +50,10 @@ expands an existing XFS filesystem (see
 The
 .I mount-point
 argument is the pathname of the directory where the filesystem
-is mounted. The filesystem must be mounted to be grown (see
+is mounted. The
+.I block-device
+argument is the device name of a mounted XFS filesystem.
+The filesystem must be mounted to be grown (see
 .BR mount (8)).
 The existing contents of the filesystem are undisturbed, and the added space
 becomes available for additional file storage.