This is a note to let you know that I've just added the patch titled
sunrpc: don't wait for write before allowing reads from use-gss-proxy file
to the 3.12-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
sunrpc-don-t-wait-for-write-before-allowing-reads-from-use-gss-proxy-file.patch
and it can be found in the queue-3.12 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 1654a04cd702fd19c297c36300a6ab834cf8c072 Mon Sep 17 00:00:00 2001
From: Jeff Layton <jlayton@xxxxxxxxxx>
Date: Sat, 4 Jan 2014 07:18:03 -0500
Subject: sunrpc: don't wait for write before allowing reads from use-gss-proxy file
From: Jeff Layton <jlayton@xxxxxxxxxx>
commit 1654a04cd702fd19c297c36300a6ab834cf8c072 upstream.
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.
Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/sunrpc/auth_gss/gss_rpc_upcall.c | 2 --
net/sunrpc/auth_gss/svcauth_gss.c | 33 ++-------------------------------
net/sunrpc/netns.h | 1 -
3 files changed, 2 insertions(+), 34 deletions(-)
--- a/net/sunrpc/auth_gss/gss_rpc_upcall.c
+++ b/net/sunrpc/auth_gss/gss_rpc_upcall.c
@@ -137,7 +137,6 @@ void init_gssp_clnt(struct sunrpc_net *s
{
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;
}
--- a/net/sunrpc/auth_gss/svcauth_gss.c
+++ b/net/sunrpc/auth_gss/svcauth_gss.c
@@ -1295,34 +1295,9 @@ static int set_gss_proxy(struct net *net
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 *fi
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;
--- a/net/sunrpc/netns.h
+++ b/net/sunrpc/netns.h
@@ -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;
Patches currently in stable-queue which might be from jlayton@xxxxxxxxxx are
queue-3.12/sunrpc-don-t-wait-for-write-before-allowing-reads-from-use-gss-proxy-file.patch
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