Re: [PATCH] erofs: avoid useless memory allocation

[Yue Hu <zbestahu@gmail.com>]

On Fri,  3 Mar 2023 16:52:18 +0900
Noboru Asai <asai@sijam.com> wrote:

> The variable 'vi->xattr_shared_count' could be ZERO.
> 
> Signed-off-by: Noboru Asai <asai@sijam.com>
> ---
>  fs/erofs/xattr.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/fs/erofs/xattr.c b/fs/erofs/xattr.c
> index 60729b1220b6..5164813a693b 100644
> --- a/fs/erofs/xattr.c
> +++ b/fs/erofs/xattr.c
> @@ -80,6 +80,8 @@ static int init_inode_xattrs(struct inode *inode)
>  
>  	ih = (struct erofs_xattr_ibody_header *)(it.kaddr + it.ofs);
>  	vi->xattr_shared_count = ih->h_shared_count;
> +	if (!vi->xattr_shared_count)
> +		goto out_unlock;

Questions: ret = 0? no need to erofs_put_metabuf?

I think we can keep current since kmalloc_array() will check whether the
size(->xattr_shared_count) is zero size or not. rt?

>  	vi->xattr_shared_xattrs = kmalloc_array(vi->xattr_shared_count,
>  						sizeof(uint), GFP_KERNEL);
>  	if (!vi->xattr_shared_xattrs) {