[PATCH v3 05/12] xprtrdma: Address coverity complaint about wait_for_completion()

Chuck Lever
2016-11-29T15:52:40Z

> ** CID 114101: Error handling issues (CHECKED_RETURN)
> /net/sunrpc/xprtrdma/verbs.c: 355 in rpcrdma_create_id()

Commit 5675add36e76 ("RPC/RDMA: harden connection logic against
missing/late rdma_cm upcalls.") replaced wait_for_completion() calls
with these two call sites.

The original wait_for_completion() calls were added in the initial
commit of verbs.c, which was commit c56c65fb67d6 ("RPCRDMA: rpc rdma
verbs interface implementation"), but these returned void.

rpcrdma_create_id() is called by the RDMA connect worker, which
probably won't ever be interrupted. It is also called by
rpcrdma_ia_open which is in the synchronous mount path, and ^C is
possible there.

Add a bit of logic at those two call sites to return if the waits
return ERESTARTSYS.

Signed-off-by: Chuck Lever <chuck.lever-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
---
net/sunrpc/xprtrdma/verbs.c | 17 +++++++++++++----
1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index 451f5f2..cbb1885 100644
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -331,6 +331,7 @@ static void rpcrdma_destroy_id(struct rdma_cm_id *id)
rpcrdma_create_id(struct rpcrdma_xprt *xprt,
struct rpcrdma_ia *ia, struct sockaddr *addr)
{
+ unsigned long wtimeout = msecs_to_jiffies(RDMA_RESOLVE_TIMEOUT) + 1;
struct rdma_cm_id *id;
int rc;

@@ -352,8 +353,12 @@ static void rpcrdma_destroy_id(struct rdma_cm_id *id)
__func__, rc);
goto out;
}
- wait_for_completion_interruptible_timeout(&ia->ri_done,
- msecs_to_jiffies(RDMA_RESOLVE_TIMEOUT) + 1);
+ rc = wait_for_completion_interruptible_timeout(&ia->ri_done, wtimeout);
+ if (rc < 0) {
+ dprintk("RPC: %s: wait() exited: %i\n",
+ __func__, rc);
+ goto out;
+ }

/* FIXME:
* Until xprtrdma supports DEVICE_REMOVAL, the provider must
@@ -376,8 +381,12 @@ static void rpcrdma_destroy_id(struct rdma_cm_id *id)
__func__, rc);
goto put;
}
- wait_for_completion_interruptible_timeout(&ia->ri_done,
- msecs_to_jiffies(RDMA_RESOLVE_TIMEOUT) + 1);
+ rc = wait_for_completion_interruptible_timeout(&ia->ri_done, wtimeout);
+ if (rc < 0) {
+ dprintk("RPC: %s: wait() exited: %i\n",
+ __func__, rc);
+ goto put;
+ }
rc = ia->ri_async_rc;
if (rc)
goto put;

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