Re: [RFC][PATCH 08/13] do_sys_truncate(): import pathname only once

On Sun 09-11-25 06:37:40, Al Viro wrote:
> Convert the user_path_at() call inside a retry loop into getname_flags() +
> filename_lookup() + putname() and leave only filename_lookup() inside
> the loop.
> 
> In this case we never pass LOOKUP_EMPTY, so getname_flags() is equivalent
> to plain getname().
> 
> The things could be further simplified by use of cleanup.h stuff, but
> let's not clutter the patch with that.
> 
> Signed-off-by: Al Viro <[email protected]>

Looks good. Feel free to add:

Reviewed-by: Jan Kara <[email protected]>

								Honza

> ---
>  fs/open.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/open.c b/fs/open.c
> index e67baae339fc..eb2ff940393d 100644
> --- a/fs/open.c
> +++ b/fs/open.c
> @@ -129,14 +129,16 @@ EXPORT_SYMBOL_GPL(vfs_truncate);
>  int do_sys_truncate(const char __user *pathname, loff_t length)
>  {
>  	unsigned int lookup_flags = LOOKUP_FOLLOW;
> +	struct filename *name;
>  	struct path path;
>  	int error;
>  
>  	if (length < 0)	/* sorry, but loff_t says... */
>  		return -EINVAL;
>  
> +	name = getname(pathname);
>  retry:
> -	error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path);
> +	error = filename_lookup(AT_FDCWD, name, lookup_flags, &path, NULL);
>  	if (!error) {
>  		error = vfs_truncate(&path, length);
>  		path_put(&path);
> @@ -145,6 +147,7 @@ int do_sys_truncate(const char __user *pathname, loff_t length)
>  		lookup_flags |= LOOKUP_REVAL;
>  		goto retry;
>  	}
> +	putname(name);
>  	return error;
>  }
>  
> -- 
> 2.47.3
> 
-- 
Jan Kara <[email protected]>
SUSE Labs, CR