diff mbox series

[6/7] crypto: ccp: no need to check return value of debugfs_create functions

Message ID 20190122151422.14204-7-gregkh@linuxfoundation.org (mailing list archive)
State Accepted
Delegated to: Herbert Xu
Headers show
Series crypto: cleanup debugfs usage | expand

Commit Message

Greg KH Jan. 22, 2019, 3:14 p.m. UTC
When calling debugfs functions, there is no need to ever check the
return value.  The function can work or not, but the code logic should
never do something different based on this.

Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Gary Hook <gary.hook@amd.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-crypto@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/crypto/ccp/ccp-debugfs.c | 36 +++++++-------------------------
 1 file changed, 7 insertions(+), 29 deletions(-)

Comments

Gary R Hook Jan. 22, 2019, 10:06 p.m. UTC | #1
On 1/22/19 9:14 AM, Greg Kroah-Hartman wrote:
> When calling debugfs functions, there is no need to ever check the
> return value.  The function can work or not, but the code logic should
> never do something different based on this.

Stupid question(s) time.

If we don't care about failures (because the subsystem handles them 
without our involvement) why do these functions even have return values? 
Why haven't they been changed to void so that they reflect the current 
style of intended use?

I realize I'm old fashioned, but if a failure occurs, I've always been 
of a mind to kick out and not try to do any further work. But debugfs is 
to be treated as an exception to that paradigm? Carry on, ignore errors, 
don't worry about it?

That said,

Acked-by: Gary R Hook <gary.hook@amd.com>

> 
> Cc: Tom Lendacky <thomas.lendacky@amd.com>
> Cc: Gary Hook <gary.hook@amd.com>
> Cc: Herbert Xu <herbert@gondor.apana.org.au>
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: linux-crypto@vger.kernel.org
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> ---
>   drivers/crypto/ccp/ccp-debugfs.c | 36 +++++++-------------------------
>   1 file changed, 7 insertions(+), 29 deletions(-)
> 
> diff --git a/drivers/crypto/ccp/ccp-debugfs.c b/drivers/crypto/ccp/ccp-debugfs.c
> index 1a734bd2070a..4bd26af7098d 100644
> --- a/drivers/crypto/ccp/ccp-debugfs.c
> +++ b/drivers/crypto/ccp/ccp-debugfs.c
> @@ -286,10 +286,7 @@ void ccp5_debugfs_setup(struct ccp_device *ccp)
>   {
>   	struct ccp_cmd_queue *cmd_q;
>   	char name[MAX_NAME_LEN + 1];
> -	struct dentry *debugfs_info;
> -	struct dentry *debugfs_stats;
>   	struct dentry *debugfs_q_instance;
> -	struct dentry *debugfs_q_stats;
>   	int i;
>   
>   	if (!debugfs_initialized())
> @@ -299,24 +296,14 @@ void ccp5_debugfs_setup(struct ccp_device *ccp)
>   	if (!ccp_debugfs_dir)
>   		ccp_debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);
>   	mutex_unlock(&ccp_debugfs_lock);
> -	if (!ccp_debugfs_dir)
> -		return;
>   
>   	ccp->debugfs_instance = debugfs_create_dir(ccp->name, ccp_debugfs_dir);
> -	if (!ccp->debugfs_instance)
> -		goto err;
>   
> -	debugfs_info = debugfs_create_file("info", 0400,
> -					   ccp->debugfs_instance, ccp,
> -					   &ccp_debugfs_info_ops);
> -	if (!debugfs_info)
> -		goto err;
> +	debugfs_create_file("info", 0400, ccp->debugfs_instance, ccp,
> +			    &ccp_debugfs_info_ops);
>   
> -	debugfs_stats = debugfs_create_file("stats", 0600,
> -					    ccp->debugfs_instance, ccp,
> -					    &ccp_debugfs_stats_ops);
> -	if (!debugfs_stats)
> -		goto err;
> +	debugfs_create_file("stats", 0600, ccp->debugfs_instance, ccp,
> +			    &ccp_debugfs_stats_ops);
>   
>   	for (i = 0; i < ccp->cmd_q_count; i++) {
>   		cmd_q = &ccp->cmd_q[i];
> @@ -325,21 +312,12 @@ void ccp5_debugfs_setup(struct ccp_device *ccp)
>   
>   		debugfs_q_instance =
>   			debugfs_create_dir(name, ccp->debugfs_instance);
> -		if (!debugfs_q_instance)
> -			goto err;
> -
> -		debugfs_q_stats =
> -			debugfs_create_file("stats", 0600,
> -					    debugfs_q_instance, cmd_q,
> -					    &ccp_debugfs_queue_ops);
> -		if (!debugfs_q_stats)
> -			goto err;
> +
> +		debugfs_create_file("stats", 0600, debugfs_q_instance, cmd_q,
> +				    &ccp_debugfs_queue_ops);
>   	}
>   
>   	return;
> -
> -err:
> -	debugfs_remove_recursive(ccp->debugfs_instance);
>   }
>   
>   void ccp5_debugfs_destroy(void)
>
Greg KH Jan. 23, 2019, 6:55 a.m. UTC | #2
On Tue, Jan 22, 2019 at 10:06:54PM +0000, Gary R Hook wrote:
> On 1/22/19 9:14 AM, Greg Kroah-Hartman wrote:
> > When calling debugfs functions, there is no need to ever check the
> > return value.  The function can work or not, but the code logic should
> > never do something different based on this.
> 
> Stupid question(s) time.
> 
> If we don't care about failures (because the subsystem handles them 
> without our involvement) why do these functions even have return values? 
> Why haven't they been changed to void so that they reflect the current 
> style of intended use?

Because on "normal" operations, you use the return value for something
(i.e. a parent directory to pass to other functions, or a value so you
can remove the file later).

> I realize I'm old fashioned, but if a failure occurs, I've always been 
> of a mind to kick out and not try to do any further work. But debugfs is 
> to be treated as an exception to that paradigm? Carry on, ignore errors, 
> don't worry about it?

Yes, that is the case here, it goes against what everyone normally
thinks about kernel development :)

thanks,

greg k-h
diff mbox series

Patch

diff --git a/drivers/crypto/ccp/ccp-debugfs.c b/drivers/crypto/ccp/ccp-debugfs.c
index 1a734bd2070a..4bd26af7098d 100644
--- a/drivers/crypto/ccp/ccp-debugfs.c
+++ b/drivers/crypto/ccp/ccp-debugfs.c
@@ -286,10 +286,7 @@  void ccp5_debugfs_setup(struct ccp_device *ccp)
 {
 	struct ccp_cmd_queue *cmd_q;
 	char name[MAX_NAME_LEN + 1];
-	struct dentry *debugfs_info;
-	struct dentry *debugfs_stats;
 	struct dentry *debugfs_q_instance;
-	struct dentry *debugfs_q_stats;
 	int i;
 
 	if (!debugfs_initialized())
@@ -299,24 +296,14 @@  void ccp5_debugfs_setup(struct ccp_device *ccp)
 	if (!ccp_debugfs_dir)
 		ccp_debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);
 	mutex_unlock(&ccp_debugfs_lock);
-	if (!ccp_debugfs_dir)
-		return;
 
 	ccp->debugfs_instance = debugfs_create_dir(ccp->name, ccp_debugfs_dir);
-	if (!ccp->debugfs_instance)
-		goto err;
 
-	debugfs_info = debugfs_create_file("info", 0400,
-					   ccp->debugfs_instance, ccp,
-					   &ccp_debugfs_info_ops);
-	if (!debugfs_info)
-		goto err;
+	debugfs_create_file("info", 0400, ccp->debugfs_instance, ccp,
+			    &ccp_debugfs_info_ops);
 
-	debugfs_stats = debugfs_create_file("stats", 0600,
-					    ccp->debugfs_instance, ccp,
-					    &ccp_debugfs_stats_ops);
-	if (!debugfs_stats)
-		goto err;
+	debugfs_create_file("stats", 0600, ccp->debugfs_instance, ccp,
+			    &ccp_debugfs_stats_ops);
 
 	for (i = 0; i < ccp->cmd_q_count; i++) {
 		cmd_q = &ccp->cmd_q[i];
@@ -325,21 +312,12 @@  void ccp5_debugfs_setup(struct ccp_device *ccp)
 
 		debugfs_q_instance =
 			debugfs_create_dir(name, ccp->debugfs_instance);
-		if (!debugfs_q_instance)
-			goto err;
-
-		debugfs_q_stats =
-			debugfs_create_file("stats", 0600,
-					    debugfs_q_instance, cmd_q,
-					    &ccp_debugfs_queue_ops);
-		if (!debugfs_q_stats)
-			goto err;
+
+		debugfs_create_file("stats", 0600, debugfs_q_instance, cmd_q,
+				    &ccp_debugfs_queue_ops);
 	}
 
 	return;
-
-err:
-	debugfs_remove_recursive(ccp->debugfs_instance);
 }
 
 void ccp5_debugfs_destroy(void)