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authorTrond Myklebust <trond.myklebust@hammerspace.com>2018-12-01 23:18:00 -0500
committerTrond Myklebust <trond.myklebust@hammerspace.com>2018-12-02 09:43:57 -0500
commit0a9a4304f3614e25d9de9b63502ca633c01c0d70 (patch)
tree683288309ec67126269473e0d6a63ae01abbabae
parent71700bb96047f68a0aae3932466fc7c9ad5ce6c0 (diff)
downloadlinux-0a9a4304f3614e25d9de9b63502ca633c01c0d70.tar.bz2
SUNRPC: Fix a potential race in xprt_connect()
If an asynchronous connection attempt completes while another task is in xprt_connect(), then the call to rpc_sleep_on() could end up racing with the call to xprt_wake_pending_tasks(). So add a second test of the connection state after we've put the task to sleep and set the XPRT_CONNECTING flag, when we know that there can be no asynchronous connection attempts still in progress. Fixes: 0b9e79431377d ("SUNRPC: Move the test for XPRT_CONNECTING into...") Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
-rw-r--r--net/sunrpc/xprt.c11
1 files changed, 9 insertions, 2 deletions
diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
index 122c91c28e7c..ce927002862a 100644
--- a/net/sunrpc/xprt.c
+++ b/net/sunrpc/xprt.c
@@ -826,8 +826,15 @@ void xprt_connect(struct rpc_task *task)
return;
if (xprt_test_and_set_connecting(xprt))
return;
- xprt->stat.connect_start = jiffies;
- xprt->ops->connect(xprt, task);
+ /* Race breaker */
+ if (!xprt_connected(xprt)) {
+ xprt->stat.connect_start = jiffies;
+ xprt->ops->connect(xprt, task);
+ } else {
+ xprt_clear_connecting(xprt);
+ task->tk_status = 0;
+ rpc_wake_up_queued_task(&xprt->pending, task);
+ }
}
xprt_release_write(xprt, task);
}