On Fri, 2017-03-31 at 23:15 -0400, Benjamin Coddington 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@xxxxxxxxxx>
> Reviewed-by: Christoph Hellwig <hch@xxxxxx>
> Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx>
> ---
> fs/nfs/file.c | 18 ++++++++++++++++--
> fs/nfs/nfs4proc.c | 14 --------------
> 2 files changed, 16 insertions(+), 16 deletions(-)
>
> diff --git a/fs/nfs/file.c b/fs/nfs/file.c
> index 26dbe8b0c10d..a490f45df4db 100644
> --- a/fs/nfs/file.c
> +++ b/fs/nfs/file.c
> @@ -820,9 +820,23 @@ int nfs_flock(struct file *filp, int cmd, struct file_lock *fl)
> if (NFS_SERVER(inode)->flags & NFS_MOUNT_LOCAL_FLOCK)
> is_local = 1;
>
> - /* We're simulating flock() locks using posix locks on the server */
> - if (fl->fl_type == F_UNLCK)
> + /*
> + * 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_UNLCK:
> return do_unlk(filp, cmd, fl, is_local);
> + 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 9388899e4050..91f88bfbbe79 100644
> --- a/fs/nfs/nfs4proc.c
> +++ b/fs/nfs/nfs4proc.c
> @@ -6592,20 +6592,6 @@ nfs4_proc_lock(struct file *filp, int cmd, struct file_lock *request)
> !test_bit(NFS_STATE_POSIX_LOCKS, &state->flags))
> 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;
> - }
> -
> status = nfs4_set_lock_state(state, request);
> if (status != 0)
> return status;
Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx>
