Return-Path: <jeff.layton@primarydata.com>
Date: Mon, 28 Dec 2015 14:37:21 -0500
From: Jeff Layton <jeff.layton@primarydata.com>
To: Benjamin Coddington <bcodding@redhat.com>
Cc: Trond Myklebust <trond.myklebust@primarydata.com>,
        Anna Schumaker
 <anna.schumaker@netapp.com>,
        "J. Bruce Fields" <bfields@fieldses.org>,
        Christoph Hellwig <hch@infradead.org>, linux-nfs@vger.kernel.org
Subject: Re: [PATCH v3 02/10] NFS: Move the flock open mode check into
 nfs_flock()
Message-ID: <20151228143721.7fca2516@tlielax.poochiereds.net>
In-Reply-To: <7d9792cc96113c508fb45e5aa88f8afc40c9f00b.1451319354.git.bcodding@redhat.com>
References: <cover.1451319354.git.bcodding@redhat.com>
	<7d9792cc96113c508fb45e5aa88f8afc40c9f00b.1451319354.git.bcodding@redhat.com>
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List-ID: <linux-nfs.vger.kernel.org>

On Mon, 28 Dec 2015 11:27:58 -0500
Benjamin Coddington <bcodding@redhat.com> wrote:

> We only need to check lock exclusive/shared types against open mode when
> flock() is used on NFS, so move it into the flock-specific path instead of
> checking it for all locks.
> 
> Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
> ---
>  fs/nfs/file.c     |   16 ++++++++++++++++
>  fs/nfs/nfs4proc.c |   13 -------------
>  2 files changed, 16 insertions(+), 13 deletions(-)
> 
> diff --git a/fs/nfs/file.c b/fs/nfs/file.c
> index 93e2364..1e4804b 100644
> --- a/fs/nfs/file.c
> +++ b/fs/nfs/file.c
> @@ -893,6 +893,22 @@ int nfs_flock(struct file *filp, int cmd, struct file_lock *fl)
>  	/* We're simulating flock() locks using posix locks on the server */
>  	if (fl->fl_type == F_UNLCK)
>  		return do_unlk(filp, cmd, fl, is_local);
> +

nit: maybe make the above and below part of the same switch?

> +	/*
> +	 * VFS doesn't require the open mode to match a flock() lock's type.
> +	 * NFS, however, may simulate flock() locking with posix locking which
> +	 * requires the open mode to match the lock type.
> +	 */
> +	switch (fl->fl_type) {
> +	case F_RDLCK:
> +		if (!(filp->f_mode & FMODE_READ))
> +			return -EBADF;
> +		break;
> +	case F_WRLCK:
> +		if (!(filp->f_mode & FMODE_WRITE))
> +			return -EBADF;
> +	}
> +
>  	return do_setlk(filp, cmd, fl, is_local);
>  }
>  EXPORT_SYMBOL_GPL(nfs_flock);
> diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
> index 2231d7d..05ea1e1 100644
> --- a/fs/nfs/nfs4proc.c
> +++ b/fs/nfs/nfs4proc.c
> @@ -6125,19 +6125,6 @@ nfs4_proc_lock(struct file *filp, int cmd, struct file_lock *request)
>  
>  	if (state == NULL)
>  		return -ENOLCK;
> -	/*
> -	 * Don't rely on the VFS having checked the file open mode,
> -	 * since it won't do this for flock() locks.
> -	 */
> -	switch (request->fl_type) {
> -	case F_RDLCK:
> -		if (!(filp->f_mode & FMODE_READ))
> -			return -EBADF;
> -		break;
> -	case F_WRLCK:
> -		if (!(filp->f_mode & FMODE_WRITE))
> -			return -EBADF;
> -	}
>  
>  	do {
>  		status = nfs4_proc_setlk(state, cmd, request);

Looks correct other than the nit above:

Reviewed-by: Jeff Layton <jeff.layton@primarydata.com>