Re: [PATCH 1/1] nfs: Ensure NFS_MOUNT_TCP is correctly set for v4 mounts

From: Trond Myklebust <trond.myklebust@primarydata.com>
To: Scott Mayhew <smayhew@redhat.com>
Cc: Linux NFS Mailing List <linux-nfs@vger.kernel.org>
Subject: Re: [PATCH 1/1] nfs: Ensure NFS_MOUNT_TCP is correctly set for v4 mounts
Date: Thu, 29 May 2014 13:33:26 -0400	[thread overview]
Message-ID: <CAHQdGtRzQVWHov8q6Ywzh2CGzcS5niEVLg7LuHmZFr6EjZbSUw@mail.gmail.com> (raw)
In-Reply-To: <1401384351-21993-2-git-send-email-smayhew@redhat.com>

On Thu, May 29, 2014 at 1:25 PM, Scott Mayhew <smayhew@redhat.com> wrote:
> The NFS_MOUNT_TCP flag needs to be correctly set in the nfs_server->flags
> field, otherwise remount operations are likely to run afoul of the flags
> check in nfs_compare_remount_data() on systems where /etc/mtab is
> symlinked to /proc/mounts.
>
> Signed-off-by: Scott Mayhew <smayhew@redhat.com>
> ---
>  fs/nfs/super.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/fs/nfs/super.c b/fs/nfs/super.c
> index 2cb5694..0ae4e73 100644
> --- a/fs/nfs/super.c
> +++ b/fs/nfs/super.c
> @@ -2726,6 +2726,9 @@ static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
>  {
>         args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3|
>                          NFS_MOUNT_LOCAL_FLOCK|NFS_MOUNT_LOCAL_FCNTL);
> +
> +       if (args->nfs_server.protocol == XPRT_TRANSPORT_TCP)
> +               args->flags |= NFS_MOUNT_TCP;
>  }
>
>  /*
> --
> 1.9.0
>

Hi Scott,

Why can't we just apply the NFS_MOUNT_CMP_FLAGMASK to
nfs_compare_remount_data? NFS_MOUNT_TCP really is just legacy crud
from the bad old days of binary mount structures.

Cheers
  Trond

-- 
Trond Myklebust

Linux NFS client maintainer, PrimaryData

trond.myklebust@primarydata.com