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author | Trond Myklebust <trond.myklebust@hammerspace.com> | 2018-12-01 23:18:00 -0500 |
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committer | Trond Myklebust <trond.myklebust@hammerspace.com> | 2018-12-02 09:43:57 -0500 |
commit | 0a9a4304f3614e25d9de9b63502ca633c01c0d70 (patch) | |
tree | 683288309ec67126269473e0d6a63ae01abbabae | |
parent | 71700bb96047f68a0aae3932466fc7c9ad5ce6c0 (diff) | |
download | linux-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.c | 11 |
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); } |