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 <[email protected]> Cc: Greg Kroah-Hartman <[email protected]> --- fs/kernfs/dir.c | 23 +++++++++++++++++++++++ include/linux/kernfs.h | 4 ++++ 2 files changed, 27 insertions(+) diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c index 2d48d28..91e0045 100644 --- a/fs/kernfs/dir.c +++ b/fs/kernfs/dir.c @@ -92,6 +92,29 @@ int kernfs_name(struct kernfs_node *kn, char *buf, size_t buflen) } /** + * kernfs_path_len - determine the length of the full path of a given node + * @kn: kernfs_node of interest + * + * The returned length doesn't include the space for the terminating '\0'. + */ +size_t kernfs_path_len(struct kernfs_node *kn) +{ + size_t len = 0; + unsigned long flags; + + spin_lock_irqsave(&kernfs_rename_lock, flags); + + do { + len += strlen(kn->name) + 1; + kn = kn->parent; + } while (kn && kn->parent); + + spin_unlock_irqrestore(&kernfs_rename_lock, flags); + + return len; +} + +/** * kernfs_path - build full path of a given node * @kn: kernfs_node of interest * @buf: buffer to copy @kn's name into 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 @@ static inline bool kernfs_ns_enabled(struct kernfs_node *kn) } 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 bool kernfs_ns_enabled(struct kernfs_node *kn) 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; } -- 2.4.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
