[PATCH v2] let kernfs_name_locked & kernfs_name return size_t

[PATCH v2] let kernfs_name_locked & kernfs_name return size_t

[Christian Brauner]

Simple patch that changes the return value of kernfs_name_locked and kernfs_name
to size_t which alignes these functions with kernfs_path_len which also returns
size_t.

Patch was made against for-4.5 branch of Tejun's cgroup tree.  (As per Tejun's
request, ccing gregkh@linuxfoundation.org and linux-kernel@vger.kernel.org.)

Changelog
        20150210: - Change return type of kernfs_name in kernfs.h as well.
                  - Build tested against Tejun's for-4.5 tree, 4.5-rc2 and
                    mainline 4.5-rc3.

*Note*, the changes in kernfs.h change the dummy return value of the static
inline definition of kernfs_name from -ENOSYS. I changed it to 0 analogous to
kernfs_path_len. I don't know if this is considered a deal-breaker.

Christian Brauner (1):
  let kernfs_name_locked & kernfs_name return size_t

 fs/kernfs/dir.c        | 4 ++--
 include/linux/kernfs.h | 6 +++---
 2 files changed, 5 insertions(+), 5 deletions(-)

-- 
2.7.1

[PATCH v2] let kernfs_name_locked & kernfs_name return size_t

[Christian Brauner]

They return the length of kn->parent or kn->name and should be aligned with
kernfs_path_len which also returns size_t.

Signed-off-by: Christian Brauner <christian.brauner@mailbox.org>
---
Changelog:
        20150210: - Change return type of kernfs_name in kernfs.h as well.
                  - Build tested against Tejun's for-4.5 tree, 4.5-rc2 and
                    mainline 4.5-rc3.
---
 fs/kernfs/dir.c        | 4 ++--
 include/linux/kernfs.h | 6 +++---
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c
index 742bf4a..a3553b8 100644
--- a/fs/kernfs/dir.c
+++ b/fs/kernfs/dir.c
@@ -39,7 +39,7 @@ static bool kernfs_lockdep(struct kernfs_node *kn)
 #endif
 }
 
-static int kernfs_name_locked(struct kernfs_node *kn, char *buf, size_t buflen)
+static size_t kernfs_name_locked(struct kernfs_node *kn, char *buf, size_t buflen)
 {
 	return strlcpy(buf, kn->parent ? kn->name : "/", buflen);
 }
@@ -80,7 +80,7 @@ static char * __must_check kernfs_path_locked(struct kernfs_node *kn, char *buf,
  *
  * This function can be called from any context.
  */
-int kernfs_name(struct kernfs_node *kn, char *buf, size_t buflen)
+size_t kernfs_name(struct kernfs_node *kn, char *buf, size_t buflen)
 {
 	unsigned long flags;
 	int ret;
diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h
index af51df3..982a198 100644
--- a/include/linux/kernfs.h
+++ b/include/linux/kernfs.h
@@ -265,7 +265,7 @@ static inline bool kernfs_ns_enabled(struct kernfs_node *kn)
 	return kn->flags & KERNFS_NS;
 }
 
-int kernfs_name(struct kernfs_node *kn, char *buf, size_t buflen);
+size_t 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);
@@ -332,8 +332,8 @@ static inline void kernfs_enable_ns(struct kernfs_node *kn) { }
 static inline bool kernfs_ns_enabled(struct kernfs_node *kn)
 { return false; }
 
-static inline int kernfs_name(struct kernfs_node *kn, char *buf, size_t buflen)
-{ return -ENOSYS; }
+static inline size_t kernfs_name(struct kernfs_node *kn, char *buf, size_t buflen)
+{ return 0; }
 
 static inline size_t kernfs_path_len(struct kernfs_node *kn)
 { return 0; }
-- 
2.7.1

Re: [PATCH v2] let kernfs_name_locked & kernfs_name return size_t

[Greg KH]

On Wed, Feb 10, 2016 at 08:07:05PM +0100, Christian Brauner wrote:
> Simple patch that changes the return value of kernfs_name_locked and kernfs_name
> to size_t which alignes these functions with kernfs_path_len which also returns
> size_t.
> 
> Patch was made against for-4.5 branch of Tejun's cgroup tree.  (As per Tejun's
> request, ccing gregkh@linuxfoundation.org and linux-kernel@vger.kernel.org.)
> 
> Changelog
>         20150210: - Change return type of kernfs_name in kernfs.h as well.
>                   - Build tested against Tejun's for-4.5 tree, 4.5-rc2 and
>                     mainline 4.5-rc3.
> 
> *Note*, the changes in kernfs.h change the dummy return value of the static
> inline definition of kernfs_name from -ENOSYS. I changed it to 0 analogous to
> kernfs_path_len. I don't know if this is considered a deal-breaker.

Please don't change that, that's a behavior change, not just a "cleanup
the return type" change.

thanks,

greg k-h