This is a note to let you know that I've just added the patch titled
lockd: use svc_set_num_threads() for thread start and stop
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
lockd-use-svc_set_num_threads-for-thread-start-and-s.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 62bd7b2f79242abab81780d2fad765603ac41c2c
Author: NeilBrown <neilb@xxxxxxx>
Date: Mon Nov 29 15:51:25 2021 +1100
lockd: use svc_set_num_threads() for thread start and stop
[ Upstream commit 6b044fbaab02292fedb17565dbb3f2528083b169 ]
svc_set_num_threads() does everything that lockd_start_svc() does, except
set sv_maxconn. It also (when passed 0) finds the threads and
stops them with kthread_stop().
So move the setting for sv_maxconn, and use svc_set_num_thread()
We now don't need nlmsvc_task.
Now that we use svc_set_num_threads() it makes sense to set svo_module.
This request that the thread exists with module_put_and_exit().
Also fix the documentation for svo_module to make this explicit.
svc_prepare_thread is now only used where it is defined, so it can be
made static.
Signed-off-by: NeilBrown <neilb@xxxxxxx>
[ cel: upstream, module_put_and_exit was replaced via a merge commit ]
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c
index 1a7c11118b320..0475c5a5d061e 100644
--- a/fs/lockd/svc.c
+++ b/fs/lockd/svc.c
@@ -55,7 +55,6 @@ EXPORT_SYMBOL_GPL(nlmsvc_ops);
static DEFINE_MUTEX(nlmsvc_mutex);
static unsigned int nlmsvc_users;
static struct svc_serv *nlmsvc_serv;
-static struct task_struct *nlmsvc_task;
unsigned long nlmsvc_timeout;
unsigned int lockd_net_id;
@@ -186,7 +185,7 @@ lockd(void *vrqstp)
svc_exit_thread(rqstp);
- return 0;
+ module_put_and_kthread_exit(0);
}
static int create_lockd_listener(struct svc_serv *serv, const char *name,
@@ -292,8 +291,8 @@ static void lockd_down_net(struct svc_serv *serv, struct net *net)
__func__, net->ns.inum);
}
} else {
- pr_err("%s: no users! task=%p, net=%x\n",
- __func__, nlmsvc_task, net->ns.inum);
+ pr_err("%s: no users! net=%x\n",
+ __func__, net->ns.inum);
BUG();
}
}
@@ -351,49 +350,11 @@ static struct notifier_block lockd_inet6addr_notifier = {
};
#endif
-static int lockd_start_svc(struct svc_serv *serv)
-{
- int error;
- struct svc_rqst *rqst;
-
- /*
- * Create the kernel thread and wait for it to start.
- */
- rqst = svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE);
- if (IS_ERR(rqst)) {
- error = PTR_ERR(rqst);
- printk(KERN_WARNING
- "lockd_up: svc_rqst allocation failed, error=%d\n",
- error);
- goto out_rqst;
- }
-
- svc_sock_update_bufs(serv);
- serv->sv_maxconn = nlm_max_connections;
-
- nlmsvc_task = kthread_create(lockd, rqst, "%s", serv->sv_name);
- if (IS_ERR(nlmsvc_task)) {
- error = PTR_ERR(nlmsvc_task);
- printk(KERN_WARNING
- "lockd_up: kthread_run failed, error=%d\n", error);
- goto out_task;
- }
- rqst->rq_task = nlmsvc_task;
- wake_up_process(nlmsvc_task);
-
- dprintk("lockd_up: service started\n");
- return 0;
-
-out_task:
- svc_exit_thread(rqst);
- nlmsvc_task = NULL;
-out_rqst:
- return error;
-}
-
static const struct svc_serv_ops lockd_sv_ops = {
.svo_shutdown = svc_rpcb_cleanup,
+ .svo_function = lockd,
.svo_enqueue_xprt = svc_xprt_do_enqueue,
+ .svo_module = THIS_MODULE,
};
static int lockd_get(void)
@@ -425,7 +386,8 @@ static int lockd_get(void)
return -ENOMEM;
}
- error = lockd_start_svc(serv);
+ serv->sv_maxconn = nlm_max_connections;
+ error = svc_set_num_threads(serv, NULL, 1);
/* The thread now holds the only reference */
svc_put(serv);
if (error < 0)
@@ -453,11 +415,7 @@ static void lockd_put(void)
unregister_inet6addr_notifier(&lockd_inet6addr_notifier);
#endif
- if (nlmsvc_task) {
- kthread_stop(nlmsvc_task);
- dprintk("lockd_down: service stopped\n");
- nlmsvc_task = NULL;
- }
+ svc_set_num_threads(nlmsvc_serv, NULL, 0);
nlmsvc_serv = NULL;
dprintk("lockd_down: service destroyed\n");
}
diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h
index 35bb1c4393400..be535cc4fea07 100644
--- a/include/linux/sunrpc/svc.h
+++ b/include/linux/sunrpc/svc.h
@@ -64,7 +64,9 @@ struct svc_serv_ops {
/* queue up a transport for servicing */
void (*svo_enqueue_xprt)(struct svc_xprt *);
- /* optional module to count when adding threads (pooled svcs only) */
+ /* optional module to count when adding threads.
+ * Thread function must call module_put_and_kthread_exit() to exit.
+ */
struct module *svo_module;
};
@@ -506,8 +508,6 @@ struct svc_serv *svc_create(struct svc_program *, unsigned int,
const struct svc_serv_ops *);
struct svc_rqst *svc_rqst_alloc(struct svc_serv *serv,
struct svc_pool *pool, int node);
-struct svc_rqst *svc_prepare_thread(struct svc_serv *serv,
- struct svc_pool *pool, int node);
void svc_rqst_replace_page(struct svc_rqst *rqstp,
struct page *page);
void svc_rqst_free(struct svc_rqst *);
diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
index fee7a22578b64..f53ff8f2602f2 100644
--- a/net/sunrpc/svc.c
+++ b/net/sunrpc/svc.c
@@ -652,7 +652,7 @@ svc_rqst_alloc(struct svc_serv *serv, struct svc_pool *pool, int node)
}
EXPORT_SYMBOL_GPL(svc_rqst_alloc);
-struct svc_rqst *
+static struct svc_rqst *
svc_prepare_thread(struct svc_serv *serv, struct svc_pool *pool, int node)
{
struct svc_rqst *rqstp;
@@ -672,7 +672,6 @@ svc_prepare_thread(struct svc_serv *serv, struct svc_pool *pool, int node)
spin_unlock_bh(&pool->sp_lock);
return rqstp;
}
-EXPORT_SYMBOL_GPL(svc_prepare_thread);
/*
* Choose a pool in which to create a new thread, for svc_set_num_threads
