commit 5d477b6079619910dab882fa229cce1f14f86cf8
author Takashi Iwai <tiwai@suse.de> Fri May 10 14:04:11 2013 +0200
committer Al Viro <viro@zeniv.linux.org.uk> Fri May 31 15:16:33 2013 -0400
tree 02d3791a335d20f6515b26aa8657b47120105796
parent a93cb29acaa8f75618c3f202d1cf43c231984644

vfs: Fix invalid ida_remove() call

When the group id of a shared mount is not allocated, the umount still
tries to call mnt_release_group_id(), which eventually hits a kernel
warning at ida_remove() spewing a message like:
  ida_remove called for id=0 which is not allocated.

This patch fixes the bug simply checking the group id in the caller.

Reported-by: Cristian Rodríguez <crrodriguez@opensuse.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/pnode.c

diff --git a/fs/pnode.c b/fs/pnode.c
index 3d2a714..9af0df1 100644
--- a/fs/pnode.c
+++ b/fs/pnode.c
@@ -83,7 +83,8 @@
 		if (peer_mnt == mnt)
 			peer_mnt = NULL;
 	}
-	if (IS_MNT_SHARED(mnt) && list_empty(&mnt->mnt_share))
+	if (mnt->mnt_group_id && IS_MNT_SHARED(mnt) &&
+	    list_empty(&mnt->mnt_share))
 		mnt_release_group_id(mnt);
 
 	list_del_init(&mnt->mnt_share);