diff options
author | Tejun Heo <tj@kernel.org> | 2015-08-19 00:54:55 +0300 |
---|---|---|
committer | Jens Axboe <axboe@fb.com> | 2015-08-19 01:49:15 +0300 |
commit | 9acee9c551f045d2c5b5261aa587331423fd7d92 (patch) | |
tree | 16f0ecafd4f842d6352dd85913283a262a8e56f0 | |
parent | 60292bcc1b240a6708aa531c8ece1da2a78d560a (diff) | |
download | linux-9acee9c551f045d2c5b5261aa587331423fd7d92.tar.xz |
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>
-rw-r--r-- | fs/kernfs/dir.c | 23 | ||||
-rw-r--r-- | include/linux/kernfs.h | 4 |
2 files changed, 27 insertions, 0 deletions
diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c index 2d48d28e1640..91e004518237 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 123be25ea15a..5d4e9c4b821d 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; } |