kernfs: remove unnecessary NULL check in __kernfs_remove()

895a068a524e ("kernfs: make kernfs_get_active() block if the node is
deactivated but not removed") added "struct kernfs_root *root =
kernfs_root(kn);" at the head of the function; however, the parameter
@kn is checked for later implying that the function may be called with
NULL.  This means that we may end up invoking kernfs_root() with NULL
which will oops.  None of the existing users invokes removal with NULL
@kn, so this bug doesn't actually trigger.

We can relocate kernfs_root() invocation after NULL check; however,
allowing NULL param tends to cause more confusion than actually
helping anything.  As there's no existing user, let's remove the
spurious NULL check.

This bug was detected by smatch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 0 insertions, 3 deletions

diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c
index a8028be6cdb7..4076e8a7c269 100644
--- a/fs/kernfs/dir.c
+++ b/fs/kernfs/dir.c
@@ -920,9 +920,6 @@ static void __kernfs_remove(struct kernfs_node *kn)
 
         lockdep_assert_held(&kernfs_mutex);
 
-        if (!kn)
-                return;
-
         pr_debug("kernfs %s: removing\n", kn->name);
 
         __kernfs_deactivate(kn);