kernfs: implement kernfs_path_len()
Add a function to determine the path length of a kernfs node. This
for now will be used by writeback tracepoint updates.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h
index 123be25..5d4e9c4 100644
--- a/include/linux/kernfs.h
+++ b/include/linux/kernfs.h
@@ -266,6 +266,7 @@
}
int kernfs_name(struct kernfs_node *kn, char *buf, size_t buflen);
+size_t kernfs_path_len(struct kernfs_node *kn);
char * __must_check kernfs_path(struct kernfs_node *kn, char *buf,
size_t buflen);
void pr_cont_kernfs_name(struct kernfs_node *kn);
@@ -332,6 +333,9 @@
static inline int kernfs_name(struct kernfs_node *kn, char *buf, size_t buflen)
{ return -ENOSYS; }
+static inline size_t kernfs_path_len(struct kernfs_node *kn)
+{ return 0; }
+
static inline char * __must_check kernfs_path(struct kernfs_node *kn, char *buf,
size_t buflen)
{ return NULL; }