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Commit 1654a04c authored by Jeff Layton's avatar Jeff Layton Committed by J. Bruce Fields
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sunrpc: don't wait for write before allowing reads from use-gss-proxy file 



It doesn't make much sense to make reads from this procfile hang. As
far as I can tell, only gssproxy itself will open this file and it
never reads from it. Change it to just give the present setting of
sn->use_gss_proxy without waiting for anything.

Note that we do not want to call use_gss_proxy() in this codepath
since an inopportune read of this file could cause it to be disabled
prematurely.

Cc: stable@vger.kernel.org
Signed-off-by: default avatarJeff Layton <jlayton@redhat.com>
Signed-off-by: default avatarJ. Bruce Fields <bfields@redhat.com>
parent 73ca6590

net/sunrpc/auth_gss/gss_rpc_upcall.c

+0 −2
Original line number Diff line number Diff line
@@ -137,7 +137,6 @@ void init_gssp_clnt(struct sunrpc_net *sn) 
{

	mutex_init(&sn->gssp_lock);

	sn->gssp_clnt = NULL;

	init_waitqueue_head(&sn->gssp_wq);

}



int set_gssp_clnt(struct net *net)
@@ -154,7 +153,6 @@ int set_gssp_clnt(struct net *net) 
		sn->gssp_clnt = clnt;

	}

	mutex_unlock(&sn->gssp_lock);

	wake_up(&sn->gssp_wq);

	return ret;

}

net/sunrpc/auth_gss/svcauth_gss.c

+2 −31
Original line number Diff line number Diff line
@@ -1295,34 +1295,9 @@ static int set_gss_proxy(struct net *net, int type) 
	else

		ret = -EBUSY;

	spin_unlock(&use_gssp_lock);

	wake_up(&sn->gssp_wq);

	return ret;

}



static inline bool gssp_ready(struct sunrpc_net *sn)

{

	switch (sn->use_gss_proxy) {

		case -1:

			return false;

		case 0:

			return true;

		case 1:

			return sn->gssp_clnt;

	}

	WARN_ON_ONCE(1);

	return false;

}



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));

}





static ssize_t write_gssp(struct file *file, const char __user *buf,

			 size_t count, loff_t *ppos)

{
@@ -1355,16 +1330,12 @@ static ssize_t read_gssp(struct file *file, char __user *buf, 
			 size_t count, loff_t *ppos)

{

	struct net *net = PDE_DATA(file_inode(file));

	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);

	unsigned long p = *ppos;

	char tbuf[10];

	size_t len;

	int ret;



	ret = wait_for_gss_proxy(net, file);

	if (ret)

		return ret;



	snprintf(tbuf, sizeof(tbuf), "%d\n", use_gss_proxy(net));

	snprintf(tbuf, sizeof(tbuf), "%d\n", sn->use_gss_proxy);

	len = strlen(tbuf);

	if (p >= len)

		return 0;

net/sunrpc/netns.h

+0 −1
Original line number Diff line number Diff line
@@ -26,7 +26,6 @@ struct sunrpc_net { 
	unsigned int rpcb_is_af_local : 1;



	struct mutex gssp_lock;

	wait_queue_head_t gssp_wq;

	struct rpc_clnt *gssp_clnt;

	int use_gss_proxy;

	int pipe_version;