[PATCH] Staging: erofs: Use !x in place of NULL comparision

[Gao Xiang]

Hi Bhanusree,

On 2019/3/21 17:37, Bhanusree Pola wrote:
> Test for NULL as !x instead of NULL comparisions for
> functions that return NULL on failure are used.
> Issue found using coccinelle
> Semantic patch used to solve the problem is as follows
> 

My personal idea...There are still several other places which use
NULL comparisions introduced by the erofs original code, eg,
super.c
53:     if (vi == NULL)
90:     if (bh == NULL) {
...

internal.h
480:                    if (unlikely(bio == NULL)) {
488:    } while (unlikely(bio == NULL));
...

Could you have time fix them as much as possible in a patch?

It will simplify erofs commit log since there are similar
patches address the same reason but with few fixes...:

staging: erofs: unzip_vle.c: Replace comparison to NULL.
staging: erofs: Modify conditional checks
staging: erofs: formatting fix to NULL comparison

... Thanks in advance...

Thanks,
Gao Xiang

> // <smpl>
> @@
> expression x;
> statement S;
> @@
> 
> x = (\(kmalloc\|devm_kzalloc\|kmalloc_array\|devm_ioremap\|
> usb_alloc_urb\|alloc_netdev\|dev_alloc_skb\)(...));
> 
> -if(x==NULL)
> +if(!x)
> // </smpl>
> 
> Signed-off-by: Bhanusree Pola <bhanusreemahesh at gmail.com>
> ---
>  drivers/staging/erofs/xattr.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/erofs/xattr.c b/drivers/staging/erofs/xattr.c
> index f716ab0446e5..515b4b446491 100644
> --- a/drivers/staging/erofs/xattr.c
> +++ b/drivers/staging/erofs/xattr.c
> @@ -107,7 +107,7 @@ static int init_inode_xattrs(struct inode *inode)
>  	vi->xattr_shared_count = ih->h_shared_count;
>  	vi->xattr_shared_xattrs = kmalloc_array(vi->xattr_shared_count,
>  						sizeof(uint), GFP_KERNEL);
> -	if (vi->xattr_shared_xattrs == NULL) {
> +	if (!vi->xattr_shared_xattrs) {
>  		xattr_iter_end(&it, atomic_map);
>  		ret = -ENOMEM;
>  		goto out_unlock;
>