Re: [PATCH] ovl: Avoid some memory allocation

[walter harms]

Am 10.02.2017 22:18, schrieb Christophe JAILLET:
> Reorder code to avoid allocating and then freeing some memory in an error
> handling path.
> 
> Signed-off-by: Christophe JAILLET <christophe.jail...@wanadoo.fr>
> ---
>  fs/overlayfs/namei.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c
> index 023bb0b03352..ba80ebb8a104 100644
> --- a/fs/overlayfs/namei.c
> +++ b/fs/overlayfs/namei.c
> @@ -35,13 +35,13 @@ static int ovl_check_redirect(struct dentry *dentry, 
> struct ovl_lookup_data *d,
>                       return 0;
>               goto fail;
>       }
> +     if (res == 0)
> +             goto invalid;
> +


perhaps:

   if (res == -ENODATA || res == -EOPNOTSUPP)
        return 0;
        
   if (ret < 0)
        goto fail;

   if (ret == 0)
        goto invalid;

I think its better to read, i guess the author also as we can find this
pattern after the other vfs_getxattr() also.

re,
 wh

>       buf = kzalloc(prelen + res + strlen(post) + 1, GFP_TEMPORARY);
>       if (!buf)
>               return -ENOMEM;
>  
> -     if (res == 0)
> -             goto invalid;
> -
>       res = vfs_getxattr(dentry, OVL_XATTR_REDIRECT, buf, res);
>       if (res < 0)
>               goto fail;