[PATCH] fs: ocfs2: dir.c: Cleaning up uninitialized variables

[PATCH] fs: ocfs2: dir.c: Cleaning up uninitialized variables

[Rickard Strandqvist]

There is a risk that the variable will be used without being initialized.

This was largely found by using a static code analysis program called cppcheck.

Signed-off-by: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
---
 fs/ocfs2/dir.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/ocfs2/dir.c b/fs/ocfs2/dir.c
index 0717662..27aa4a1 100644
--- a/fs/ocfs2/dir.c
+++ b/fs/ocfs2/dir.c
@@ -3738,7 +3738,7 @@ static int ocfs2_dx_dir_rebalance(struct ocfs2_super *osb, struct inode *dir,
 	int credits, ret, i, num_used, did_quota = 0;
 	u32 cpos, split_hash, insert_hash = hinfo->major_hash;
 	u64 orig_leaves_start;
-	int num_dx_leaves;
+	int num_dx_leaves = 0;
 	struct buffer_head **orig_dx_leaves = NULL;
 	struct buffer_head **new_dx_leaves = NULL;
 	struct ocfs2_alloc_context *data_ac = NULL, *meta_ac = NULL;
-- 
1.7.10.4

Re: [PATCH] fs: ocfs2: dir.c: Cleaning up uninitialized variables

[Srinivas Eeda]

Acked-by: Srinivas Eeda <srinivas.eeda@oracle.com>

On 06/01/2014 06:53 AM, Rickard Strandqvist wrote:
> There is a risk that the variable will be used without being initialized.
>
> This was largely found by using a static code analysis program called cppcheck.
>
> Signed-off-by: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
> ---
>   fs/ocfs2/dir.c |    2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/ocfs2/dir.c b/fs/ocfs2/dir.c
> index 0717662..27aa4a1 100644
> --- a/fs/ocfs2/dir.c
> +++ b/fs/ocfs2/dir.c
> @@ -3738,7 +3738,7 @@ static int ocfs2_dx_dir_rebalance(struct ocfs2_super *osb, struct inode *dir,
>   	int credits, ret, i, num_used, did_quota = 0;
>   	u32 cpos, split_hash, insert_hash = hinfo->major_hash;
>   	u64 orig_leaves_start;
> -	int num_dx_leaves;
> +	int num_dx_leaves = 0;
>   	struct buffer_head **orig_dx_leaves = NULL;
>   	struct buffer_head **new_dx_leaves = NULL;
>   	struct ocfs2_alloc_context *data_ac = NULL, *meta_ac = NULL;

Re: [PATCH] fs: ocfs2: dir.c: Cleaning up uninitialized variables

[Andrew Morton]

On Sun,  1 Jun 2014 15:53:04 +0200 Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se> wrote:

> There is a risk that the variable will be used without being initialized.

um, no there isn't.

> --- a/fs/ocfs2/dir.c
> +++ b/fs/ocfs2/dir.c
> @@ -3738,7 +3738,7 @@ static int ocfs2_dx_dir_rebalance(struct ocfs2_super *osb, struct inode *dir,
>  	int credits, ret, i, num_used, did_quota = 0;
>  	u32 cpos, split_hash, insert_hash = hinfo->major_hash;
>  	u64 orig_leaves_start;
> -	int num_dx_leaves;
> +	int num_dx_leaves = 0;
>  	struct buffer_head **orig_dx_leaves = NULL;
>  	struct buffer_head **new_dx_leaves = NULL;
>  	struct ocfs2_alloc_context *data_ac = NULL, *meta_ac = NULL;

If ocfs2_dx_dir_kmalloc_leaves() returns non-zero, num_dx_leaves will
have been initialized.

Re: [PATCH] fs: ocfs2: dir.c: Cleaning up uninitialized variables

[Rickard Strandqvist]

Hi

Yes, but if() above, there may be a:
goto out;

Or if kcalloc() fails in ocfs2_dx_dir_kmalloc_leaves() the variable
num_dx_leaves will not be set to any value.

But now that I look more carefully at it, I see that in the cases
orig_dx_leaves and new_dx_leaves ar NULL, so nothing will happen in
the out: part of the code.

Sorry about this :-(


Best regards
Rickard Strandqvist


2014-06-02 22:22 GMT+02:00 Andrew Morton <akpm@linux-foundation.org>:
> On Sun,  1 Jun 2014 15:53:04 +0200 Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se> wrote:
>
>> There is a risk that the variable will be used without being initialized.
>
> um, no there isn't.
>
>> --- a/fs/ocfs2/dir.c
>> +++ b/fs/ocfs2/dir.c
>> @@ -3738,7 +3738,7 @@ static int ocfs2_dx_dir_rebalance(struct ocfs2_super *osb, struct inode *dir,
>>       int credits, ret, i, num_used, did_quota = 0;
>>       u32 cpos, split_hash, insert_hash = hinfo->major_hash;
>>       u64 orig_leaves_start;
>> -     int num_dx_leaves;
>> +     int num_dx_leaves = 0;
>>       struct buffer_head **orig_dx_leaves = NULL;
>>       struct buffer_head **new_dx_leaves = NULL;
>>       struct ocfs2_alloc_context *data_ac = NULL, *meta_ac = NULL;
>
> If ocfs2_dx_dir_kmalloc_leaves() returns non-zero, num_dx_leaves will
> have been initialized.
>