From: Benjamin Coddington <bcodding@redhat.com>
Date: Fri, 3 Mar 2023 21:08:32 +0000 (-0500)
Subject: SUNRPC: Fix a server shutdown leak
X-Git-Tag: baikal/mips/sdk6.1~234
X-Git-Url: https://git.baikalelectronics.ru/?a=commitdiff_plain;h=b3aa4b8291eca0dc28898f7f71726f66752d4774;p=kernel.git

SUNRPC: Fix a server shutdown leak

[ Upstream commit 5cfe6e5a040be6210c515bc2001c3bff5ebfd720 ]

Fix a race where kthread_stop() may prevent the threadfn from ever getting
called.  If that happens the svc_rqst will not be cleaned up.

Fixes: 025a3b57f381 ("NFSv4: Fix callback server shutdown")
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
index 24577d1b99079..9ee32e06f877e 100644
--- a/net/sunrpc/svc.c
+++ b/net/sunrpc/svc.c
@@ -787,6 +787,7 @@ svc_start_kthreads(struct svc_serv *serv, struct svc_pool *pool, int nrservs)
 static int
 svc_stop_kthreads(struct svc_serv *serv, struct svc_pool *pool, int nrservs)
 {
+	struct svc_rqst	*rqstp;
 	struct task_struct *task;
 	unsigned int state = serv->sv_nrthreads-1;
 
@@ -795,7 +796,10 @@ svc_stop_kthreads(struct svc_serv *serv, struct svc_pool *pool, int nrservs)
 		task = choose_victim(serv, pool, &state);
 		if (task == NULL)
 			break;
-		kthread_stop(task);
+		rqstp = kthread_data(task);
+		/* Did we lose a race to svo_function threadfn? */
+		if (kthread_stop(task) == -EINTR)
+			svc_exit_thread(rqstp);
 		nrservs++;
 	} while (nrservs < 0);
 	return 0;