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SUNRPC: Fix a race in xs_tcp_state_change()

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When scheduling the autoclose RPC call, we want to ensure that we don't
race against the test_bit() call in xprt_clear_locked().

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Trond Myklebust 2007-11-06 10:18:36 -05:00
parent ef818a28fa
commit 66af1e5585
3 changed files with 22 additions and 4 deletions
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1
include/linux/sunrpc/xprt.h
View File

@ -246,6 +246,7 @@ struct rpc_rqst * xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid);
void xprt_complete_rqst(struct rpc_task *task, int copied);
void xprt_release_rqst_cong(struct rpc_task *task);
void xprt_disconnect(struct rpc_xprt *xprt);
void xprt_force_disconnect(struct rpc_xprt *xprt);
/*
* Reserved bit positions in xprt->state

20
net/sunrpc/xprt.c
View File

@ -570,6 +570,7 @@ static void xprt_autoclose(struct work_struct *work)
xprt_disconnect(xprt);
xprt->ops->close(xprt);
clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
xprt_release_write(xprt, NULL);
}
@ -588,6 +589,25 @@ void xprt_disconnect(struct rpc_xprt *xprt)
}
EXPORT_SYMBOL_GPL(xprt_disconnect);
/**
* xprt_force_disconnect - force a transport to disconnect
* @xprt: transport to disconnect
*
*/
void xprt_force_disconnect(struct rpc_xprt *xprt)
{
/* Don't race with the test_bit() in xprt_clear_locked() */
spin_lock_bh(&xprt->transport_lock);
set_bit(XPRT_CLOSE_WAIT, &xprt->state);
/* Try to schedule an autoclose RPC call */
if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0)
queue_work(rpciod_workqueue, &xprt->task_cleanup);
else if (xprt->snd_task != NULL)
rpc_wake_up_task(xprt->snd_task);
spin_unlock_bh(&xprt->transport_lock);
}
EXPORT_SYMBOL_GPL(xprt_force_disconnect);
static void
xprt_init_autodisconnect(unsigned long data)
{

5
net/sunrpc/xprtsock.c
View File

@ -1122,10 +1122,7 @@ static void xs_tcp_state_change(struct sock *sk)
case TCP_SYN_RECV:
break;
case TCP_CLOSE_WAIT:
/* Try to schedule an autoclose RPC calls */
set_bit(XPRT_CLOSE_WAIT, &xprt->state);
if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0)
queue_work(rpciod_workqueue, &xprt->task_cleanup);
xprt_force_disconnect(xprt);
default:
xprt_disconnect(xprt);
}