diff options
| author | Trond Myklebust <Trond.Myklebust@netapp.com> | 2008-03-21 23:19:41 +0300 |
|---|---|---|
| committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2008-04-20 00:53:20 +0400 |
| commit | 1e799b673c6b82b336ab13c48b5651d511ca3000 (patch) | |
| tree | 9954155b2a9bdd72e49a078418ceea6c47bcc609 /net/sunrpc | |
| parent | c1d519312dcdf11532fed9f99a8ecc3547ffd9d6 (diff) | |
| download | linux-1e799b673c6b82b336ab13c48b5651d511ca3000.tar.xz | |
SUNRPC: Fix read ordering problems with req->rq_private_buf.len
We want to ensure that req->rq_private_buf.len is updated before
req->rq_received, so that call_decode() doesn't use an old value for
req->rq_rcv_buf.len.
In 'call_decode()' itself, instead of using task->tk_status (which is set
using req->rq_received) must use the actual value of
req->rq_private_buf.len when deciding whether or not the received RPC reply
is too short.
Finally ensure that we set req->rq_rcv_buf.len to zero when retrying a
request. A typo meant that we were resetting req->rq_private_buf.len in
call_decode(), and then clobbering that value with the old rq_rcv_buf.len
again in xprt_transmit().
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'net/sunrpc')
| -rw-r--r-- | net/sunrpc/clnt.c | 26 | ||||
| -rw-r--r-- | net/sunrpc/xprt.c | 3 |
2 files changed, 15 insertions, 14 deletions
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c index 522b06849f86..3ae560464513 100644 --- a/net/sunrpc/clnt.c +++ b/net/sunrpc/clnt.c @@ -1199,18 +1199,6 @@ call_decode(struct rpc_task *task) task->tk_flags &= ~RPC_CALL_MAJORSEEN; } - if (task->tk_status < 12) { - if (!RPC_IS_SOFT(task)) { - task->tk_action = call_bind; - clnt->cl_stats->rpcretrans++; - goto out_retry; - } - dprintk("RPC: %s: too small RPC reply size (%d bytes)\n", - clnt->cl_protname, task->tk_status); - task->tk_action = call_timeout; - goto out_retry; - } - /* * Ensure that we see all writes made by xprt_complete_rqst() * before it changed req->rq_received. @@ -1222,6 +1210,18 @@ call_decode(struct rpc_task *task) WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf, sizeof(req->rq_rcv_buf)) != 0); + if (req->rq_rcv_buf.len < 12) { + if (!RPC_IS_SOFT(task)) { + task->tk_action = call_bind; + clnt->cl_stats->rpcretrans++; + goto out_retry; + } + dprintk("RPC: %s: too small RPC reply size (%d bytes)\n", + clnt->cl_protname, task->tk_status); + task->tk_action = call_timeout; + goto out_retry; + } + /* Verify the RPC header */ p = call_verify(task); if (IS_ERR(p)) { @@ -1243,7 +1243,7 @@ out_retry: task->tk_status = 0; /* Note: call_verify() may have freed the RPC slot */ if (task->tk_rqstp == req) { - req->rq_received = req->rq_private_buf.len = 0; + req->rq_received = req->rq_rcv_buf.len = 0; if (task->tk_client->cl_discrtry) xprt_force_disconnect(task->tk_xprt); } diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c index 3ba64f9f84ba..5110a4ea7fdf 100644 --- a/net/sunrpc/xprt.c +++ b/net/sunrpc/xprt.c @@ -757,9 +757,10 @@ void xprt_complete_rqst(struct rpc_task *task, int copied) task->tk_rtt = (long)jiffies - req->rq_xtime; list_del_init(&req->rq_list); + req->rq_private_buf.len = copied; /* Ensure all writes are done before we update req->rq_received */ smp_wmb(); - req->rq_received = req->rq_private_buf.len = copied; + req->rq_received = copied; rpc_wake_up_queued_task(&xprt->pending, task); } EXPORT_SYMBOL_GPL(xprt_complete_rqst); |