[PATCH] BUG 9965: Set lease only on regular files.

[Jeff Layton]

On Sat, 22 Jun 2013 10:48:57 +0200
Andreas Schneider <asn at samba.org> wrote:

> 
> Signed-off-by: Andreas Schneider <asn at samba.org>
> ---
>  source3/smbd/oplock_linux.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/source3/smbd/oplock_linux.c b/source3/smbd/oplock_linux.c
> index 7fa9b7c..9464d7a 100644
> --- a/source3/smbd/oplock_linux.c
> +++ b/source3/smbd/oplock_linux.c
> @@ -74,8 +74,20 @@ int linux_set_lease_sighandler(int fd)
>  
>  int linux_setlease(int fd, int leasetype)
>  {
> +	struct stat sb;
>  	int ret;
>  
> +	ret = fstat(fd, &sb);
> +	if (ret == -1) {
> +		return -1;
> +	}
> +
> +	/* We can't set a lease on special files like pipes */
> +	if (!S_ISREG(sb.st_mode)) {
> +		errno = EINVAL;
> +		return -1;
> +	}
> +
>  	/* First set the signal handler. */
>  	if (linux_set_lease_sighandler(fd) == -1) {
>  		return -1;

(apologies for the resend -- the original mail had a screwed up cc list...)

Attempting to set a lease isn't be harmful, and it seems like adding an
extra fstat() call here to handle the case where it's not a normal file
is less than ideal.

Might it be better instead to go ahead and just try to set a lease and
only do the fstat() if you get an EINVAL back? If it turns out not to
be a regular file then you can just not bother to log the error...
-- 
Jeff Layton <jlayton at samba.org>