[PATCH V2] kernel/res_counter.c: replace simple_strtoull by kstrtoull

[PATCH V2] kernel/res_counter.c: replace simple_strtoull by kstrtoull

[Fabian Frederick]

Thanks to Andrew Morton for commenting first version.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Fabian Frederick <fabf@skynet.be>
---
V2: Suggestions by Andrew Morton
-use internal rc variable
-simplify if condition
 kernel/res_counter.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/res_counter.c b/kernel/res_counter.c
index 51dbac6..f65a95c 100644
--- a/kernel/res_counter.c
+++ b/kernel/res_counter.c
@@ -186,8 +186,8 @@ int res_counter_memparse_write_strategy(const char *buf,
 
 	/* return RES_COUNTER_MAX(unlimited) if "-1" is specified */
 	if (*buf == '-') {
-		res = simple_strtoull(buf + 1, &end, 10);
-		if (res != 1 || *end != '\0')
+		int rc = kstrtoull(buf + 1, 10, &res);
+		if ((res != 1) || rc)
 			return -EINVAL;
 		*resp = RES_COUNTER_MAX;
 		return 0;
-- 
1.9.1

Re: [PATCH V2] kernel/res_counter.c: replace simple_strtoull by kstrtoull

[Andrew Morton]

On Thu, 8 May 2014 19:00:43 +0200 Fabian Frederick <fabf@skynet.be> wrote:

> ...
>
> --- a/kernel/res_counter.c
> +++ b/kernel/res_counter.c
> @@ -186,8 +186,8 @@ int res_counter_memparse_write_strategy(const char *buf,
>  
>  	/* return RES_COUNTER_MAX(unlimited) if "-1" is specified */
>  	if (*buf == '-') {
> -		res = simple_strtoull(buf + 1, &end, 10);
> -		if (res != 1 || *end != '\0')
> +		int rc = kstrtoull(buf + 1, 10, &res);
> +		if ((res != 1) || rc)
>  			return -EINVAL;
>  		*resp = RES_COUNTER_MAX;

Two more things!

- there should be a newline after definitions, before code.

- we shouldn't overwrite the kstrtoull() return value.  In this case it
  might have returned -ERANGE but this code will replace that with EINVAL.

--- a/kernel/res_counter.c~kernel-res_counterc-replace-simple_strtoull-by-kstrtoull-fix
+++ a/kernel/res_counter.c
@@ -189,7 +189,10 @@ int res_counter_memparse_write_strategy(
 	/* return RES_COUNTER_MAX(unlimited) if "-1" is specified */
 	if (*buf == '-') {
 		int rc = kstrtoull(buf + 1, 10, &res);
-		if ((res != 1) || rc)
+
+		if (rc)
+			return rc;	
+		if (res != 1)
 			return -EINVAL;
 		*resp = RES_COUNTER_MAX;
 		return 0;
_