[ 04/82] sunrpc: fix loss of task->tk_status after rpc_delay call in xprt_alloc_slot

Ben Hutchings
2012-06-08T05:28:38Z

From: Trond Myklebust <Trond.Myklebust@netapp.com>

commit 1afeaf5c29aa07db25760d2fbed5c08a3aec3498 upstream.

xprt_alloc_slot will call rpc_delay() to make the task wait a bit before
retrying when it gets back an -ENOMEM error from xprt_dynamic_alloc_slot.
The problem is that rpc_delay will clear the task->tk_status, causing
call_reserveresult to abort the task.

The solution is simply to let call_reserveresult handle the ENOMEM error
directly.

Reported-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
net/sunrpc/clnt.c | 2 ++
net/sunrpc/xprt.c | 5 +++--
2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index adf2990..25302c8 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -1288,6 +1288,8 @@ call_reserveresult(struct rpc_task *task)
}

switch (status) {
+ case -ENOMEM:
+ rpc_delay(task, HZ >> 2);
case -EAGAIN: /* woken up; retry */
task->tk_action = call_reserve;
return;
diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
index b239e75..d7ccd79 100644
--- a/net/sunrpc/xprt.c
+++ b/net/sunrpc/xprt.c
@@ -984,15 +984,16 @@ static void xprt_alloc_slot(struct rpc_task *task)
goto out_init_req;
switch (PTR_ERR(req)) {
case -ENOMEM:
- rpc_delay(task, HZ >> 2);
dprintk("RPC: dynamic allocation of request slot "
"failed! Retrying\n");
+ task->tk_status = -ENOMEM;
break;
case -EAGAIN:
rpc_sleep_on(&xprt->backlog, task, NULL);
dprintk("RPC: waiting for request slot\n");
+ default:
+ task->tk_status = -EAGAIN;
}
- task->tk_status = -EAGAIN;
return;
out_init_req:
task->tk_status = 0;