From: Benjamin Coddington <bcodding@redhat.com>
Date: Fri, 3 Mar 2023 16:08:32 -0500
Subject: [PATCH] SUNRPC: Fix a server shutdown leak
Git-commit: 9ca6705d9d609441d34f8b853e1e4a6369b3b171
Patch-mainline: v6.3
References: git-fixes
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: ed6473ddc704 ("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>
Acked-by: NeilBrown <neilb@suse.com>
---
net/sunrpc/svc.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
--- a/net/sunrpc/svc.c
+++ b/net/sunrpc/svc.c
@@ -804,6 +804,7 @@ EXPORT_SYMBOL_GPL(svc_set_num_threads);
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;
@@ -812,7 +813,10 @@ svc_stop_kthreads(struct svc_serv *serv,
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;