2022-01-14 00:59:09

by CGEL

Subject: [PATCH] NFS: Replace one-element array with flexible-array member

From: Changcheng Deng <[email protected]>

There is a regular need in the kernel to provide a way to declare having
a dynamically sized set of trailing elements in a structure. Kernel code
should always use “flexible array members” for these cases. The older
style of one-element or zero-length arrays should no longer be used.

Reference:
https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-
and-one-element-arrays

Reported-by: Zeal Robot <[email protected]>
Signed-off-by: Changcheng Deng <[email protected]>
---
include/linux/nfs_xdr.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index 39390d9df9e1..7f51edd5785a 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -421,7 +421,7 @@ struct nfs42_layout_error {
__u64 offset;
__u64 length;
nfs4_stateid stateid;
- struct nfs42_device_error errors[1];
+ struct nfs42_device_error errors[];
};

#define NFS42_LAYOUTERROR_MAX 5
--
2.25.1

2022-01-14 03:59:36

by Trond Myklebust

Subject: Re: [PATCH] NFS: Replace one-element array with flexible-array member

On Fri, 2022-01-14 at 00:57 +0000, [email protected] wrote:
> From: Changcheng Deng <[email protected]>
>
> There is a regular need in the kernel to provide a way to declare
> having
> a dynamically sized set of trailing elements in a structure. Kernel
> code
> should always use “flexible array members” for these cases. The older
> style of one-element or zero-length arrays should no longer be used.
>
> Reference:
> https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length
> -
> and-one-element-arrays
>
> Reported-by: Zeal Robot <[email protected]>
> Signed-off-by: Changcheng Deng <[email protected]>
> ---
>  include/linux/nfs_xdr.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
> index 39390d9df9e1..7f51edd5785a 100644
> --- a/include/linux/nfs_xdr.h
> +++ b/include/linux/nfs_xdr.h
> @@ -421,7 +421,7 @@ struct nfs42_layout_error {
>         __u64 offset;
>         __u64 length;
>         nfs4_stateid stateid;
> -       struct nfs42_device_error errors[1];
> +       struct nfs42_device_error errors[];
>  };
>  
>  #define NFS42_LAYOUTERROR_MAX 5

NACK. This is a fixed size array of length 1, not a variable size
array. Please fix your tool.

--
Trond Myklebust
Linux NFS client maintainer, Hammerspace
[email protected]