[PATCH] zcache: initialize module properly when zcache=FOO is given

[PATCH] zcache: initialize module properly when zcache=FOO is given

[Michal Hocko]

835f2f51 (staging: zcache: enable zcache to be built/loaded as a module)
introduced in 3.10-rc1 has introduced a bug for zcache=FOO module
parameter processing.

zcache_comp_init return code doesn't agree with crypto_has_comp which
uses 1 for the success unlike zcache_comp_init which uses 0. This
causes module loading failure even if the given algorithm is supported:
[    0.815330] zcache: compressor initialization failed

Reported-by: Cristian RodrA-guez <crrodriguez@opensuse.org>
Signed-off-by: Michal Hocko <mhocko@suse.cz>
---
 drivers/staging/zcache/zcache-main.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/zcache/zcache-main.c b/drivers/staging/zcache/zcache-main.c
index dcceed2..0fe530b 100644
--- a/drivers/staging/zcache/zcache-main.c
+++ b/drivers/staging/zcache/zcache-main.c
@@ -1811,10 +1811,12 @@ static int zcache_comp_init(void)
 #else
 	if (*zcache_comp_name != '\0') {
 		ret = crypto_has_comp(zcache_comp_name, 0, 0);
-		if (!ret)
+		if (!ret) {
 			pr_info("zcache: %s not supported\n",
 					zcache_comp_name);
-		goto out;
+			goto out;
+		}
+		goto out_alloc;
 	}
 	if (!ret)
 		strcpy(zcache_comp_name, "lzo");
@@ -1827,6 +1829,7 @@ static int zcache_comp_init(void)
 	pr_info("zcache: using %s compressor\n", zcache_comp_name);
 
 	/* alloc percpu transforms */
+out_alloc:
 	ret = 0;
 	zcache_comp_pcpu_tfms = alloc_percpu(struct crypto_comp *);
 	if (!zcache_comp_pcpu_tfms)
-- 
1.8.3.1

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Re: [PATCH] zcache: initialize module properly when zcache=FOO is given

[Konrad Rzeszutek Wilk]

On Wed, Jun 26, 2013 at 04:49:02PM +0200, Michal Hocko wrote:
> 835f2f51 (staging: zcache: enable zcache to be built/loaded as a module)
> introduced in 3.10-rc1 has introduced a bug for zcache=FOO module
> parameter processing.
> 
> zcache_comp_init return code doesn't agree with crypto_has_comp which
> uses 1 for the success unlike zcache_comp_init which uses 0. This
> causes module loading failure even if the given algorithm is supported:
> [    0.815330] zcache: compressor initialization failed
> 
> Reported-by: Cristian Rodríguez <crrodriguez@opensuse.org>
> Signed-off-by: Michal Hocko <mhocko@suse.cz>

Looks OK to me.

Cc-ing Greg.

> ---
>  drivers/staging/zcache/zcache-main.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/staging/zcache/zcache-main.c b/drivers/staging/zcache/zcache-main.c
> index dcceed2..0fe530b 100644
> --- a/drivers/staging/zcache/zcache-main.c
> +++ b/drivers/staging/zcache/zcache-main.c
> @@ -1811,10 +1811,12 @@ static int zcache_comp_init(void)
>  #else
>  	if (*zcache_comp_name != '\0') {
>  		ret = crypto_has_comp(zcache_comp_name, 0, 0);
> -		if (!ret)
> +		if (!ret) {
>  			pr_info("zcache: %s not supported\n",
>  					zcache_comp_name);
> -		goto out;
> +			goto out;
> +		}
> +		goto out_alloc;
>  	}
>  	if (!ret)
>  		strcpy(zcache_comp_name, "lzo");
> @@ -1827,6 +1829,7 @@ static int zcache_comp_init(void)
>  	pr_info("zcache: using %s compressor\n", zcache_comp_name);
>  
>  	/* alloc percpu transforms */
> +out_alloc:
>  	ret = 0;
>  	zcache_comp_pcpu_tfms = alloc_percpu(struct crypto_comp *);
>  	if (!zcache_comp_pcpu_tfms)
> -- 
> 1.8.3.1
> 

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Re: [PATCH] zcache: initialize module properly when zcache=FOO is given

[Greg KH]

On Wed, Jun 26, 2013 at 11:01:16AM -0400, Konrad Rzeszutek Wilk wrote:
> On Wed, Jun 26, 2013 at 04:49:02PM +0200, Michal Hocko wrote:
> > 835f2f51 (staging: zcache: enable zcache to be built/loaded as a module)
> > introduced in 3.10-rc1 has introduced a bug for zcache=FOO module
> > parameter processing.
> > 
> > zcache_comp_init return code doesn't agree with crypto_has_comp which
> > uses 1 for the success unlike zcache_comp_init which uses 0. This
> > causes module loading failure even if the given algorithm is supported:
> > [    0.815330] zcache: compressor initialization failed
> > 
> > Reported-by: Cristian Rodriguez <crrodriguez@opensuse.org>
> > Signed-off-by: Michal Hocko <mhocko@suse.cz>
> 
> Looks OK to me.
> 
> Cc-ing Greg.

That's nice, but can someone resend it in a format that I can apply it
in, with your ack?

thanks,

greg k-h

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