2013-05-24 22:12:34

by J. Bruce Fields

Subject: [PATCH] svcrpc: implement O_NONBLOCK behavior for use-gss-proxy

From: "J. Bruce Fields" <[email protected]>

Somebody noticed LTP was complaining about O_NONBLOCK opens of
/proc/net/rpc/use-gss-proxy succeeding and then a following read
hanging.

I'm not convinced LTP really has any business opening random proc files
and expecting them to behave a certain way. And I don't really know if
this is really a bug.

But in any case perhaps the O_NONBLOCK behavior could be useful for
someone that wants to test whether gss-proxy is up without waiting.

Reported-by: Jan Stancek <[email protected]>
Signed-off-by: J. Bruce Fields <[email protected]>
---
net/sunrpc/auth_gss/svcauth_gss.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

Considering for 3.10.

diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c
index 9f0f017..618ccf5 100644
--- a/net/sunrpc/auth_gss/svcauth_gss.c
+++ b/net/sunrpc/auth_gss/svcauth_gss.c
@@ -1313,10 +1313,12 @@ static inline bool gssp_ready(struct sunrpc_net *sn)
return false;
}

-static int wait_for_gss_proxy(struct net *net)
+static int wait_for_gss_proxy(struct net *net, struct file *file)
{
struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);

+ if (file->f_flags & O_NONBLOCK && !gssp_ready(sn))
+ return -EAGAIN;
return wait_event_interruptible(sn->gssp_wq, gssp_ready(sn));
}

@@ -1358,7 +1360,7 @@ static ssize_t read_gssp(struct file *file, char __user *buf,
size_t len;
int ret;

- ret = wait_for_gss_proxy(net);
+ ret = wait_for_gss_proxy(net, file);
if (ret)
return ret;

--
1.7.9.5

2013-05-26 15:08:01

by Simo Sorce

Subject: Re: [PATCH] svcrpc: implement O_NONBLOCK behavior for use-gss-proxy

On Fri, 2013-05-24 at 18:12 -0400, J. Bruce Fields wrote:
> From: "J. Bruce Fields" <[email protected]>
>
> Somebody noticed LTP was complaining about O_NONBLOCK opens of
> /proc/net/rpc/use-gss-proxy succeeding and then a following read
> hanging.
>
> I'm not convinced LTP really has any business opening random proc files
> and expecting them to behave a certain way. And I don't really know if
> this is really a bug.
>
> But in any case perhaps the O_NONBLOCK behavior could be useful for
> someone that wants to test whether gss-proxy is up without waiting.
>
> Reported-by: Jan Stancek <[email protected]>
> Signed-off-by: J. Bruce Fields <[email protected]>

Ack by me.

Simo.


> ---
> net/sunrpc/auth_gss/svcauth_gss.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> Considering for 3.10.
>
> diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c
> index 9f0f017..618ccf5 100644
> --- a/net/sunrpc/auth_gss/svcauth_gss.c
> +++ b/net/sunrpc/auth_gss/svcauth_gss.c
> @@ -1313,10 +1313,12 @@ static inline bool gssp_ready(struct sunrpc_net *sn)
> return false;
> }
>
> -static int wait_for_gss_proxy(struct net *net)
> +static int wait_for_gss_proxy(struct net *net, struct file *file)
> {
> struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
>
> + if (file->f_flags & O_NONBLOCK && !gssp_ready(sn))
> + return -EAGAIN;
> return wait_event_interruptible(sn->gssp_wq, gssp_ready(sn));
> }
>
> @@ -1358,7 +1360,7 @@ static ssize_t read_gssp(struct file *file, char __user *buf,
> size_t len;
> int ret;
>
> - ret = wait_for_gss_proxy(net);
> + ret = wait_for_gss_proxy(net, file);
> if (ret)
> return ret;
>


--
Simo Sorce * Red Hat, Inc * New York