From: NeilBrown <neilb@xxxxxxx>
Using svc_recv() for (NFSv4.1) back-channel handling means we have just
one mechanism for waking threads.
Also change kthread_freezable_should_stop() in nfs4_callback_svc() to
kthread_should_stop() as used elsewhere.
kthread_freezable_should_stop() effectively adds a try_to_freeze() call,
and svc_recv() already contains that at an appropriate place.
Signed-off-by: NeilBrown <neilb@xxxxxxx>
Cc: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
Cc: Anna Schumaker <Anna.Schumaker@xxxxxxxxxx>
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
fs/nfs/callback.c | 42 ++-----------------------------------
include/linux/sunrpc/svc.h | 2 --
net/sunrpc/backchannel_rqst.c | 8 +++----
net/sunrpc/svc.c | 2 +-
net/sunrpc/svc_xprt.c | 27 ++++++++++++++++++++++++
net/sunrpc/xprtrdma/backchannel.c | 2 +-
6 files changed, 34 insertions(+), 49 deletions(-)
diff --git a/fs/nfs/callback.c b/fs/nfs/callback.c
index 272e6d2bb478..42a0c2f1e785 100644
--- a/fs/nfs/callback.c
+++ b/fs/nfs/callback.c
@@ -78,7 +78,7 @@ nfs4_callback_svc(void *vrqstp)
set_freezable();
- while (!kthread_freezable_should_stop(NULL))
+ while (!kthread_should_stop())
svc_recv(rqstp);
svc_exit_thread(rqstp);
@@ -86,41 +86,6 @@ nfs4_callback_svc(void *vrqstp)
}
#if defined(CONFIG_NFS_V4_1)
-/*
- * The callback service for NFSv4.1 callbacks
- */
-static int
-nfs41_callback_svc(void *vrqstp)
-{
- struct svc_rqst *rqstp = vrqstp;
- struct svc_serv *serv = rqstp->rq_server;
- struct rpc_rqst *req;
- DEFINE_WAIT(wq);
-
- set_freezable();
-
- while (!kthread_freezable_should_stop(NULL)) {
- prepare_to_wait(&serv->sv_cb_waitq, &wq, TASK_IDLE);
- spin_lock_bh(&serv->sv_cb_lock);
- if (!list_empty(&serv->sv_cb_list)) {
- req = list_first_entry(&serv->sv_cb_list,
- struct rpc_rqst, rq_bc_list);
- list_del(&req->rq_bc_list);
- spin_unlock_bh(&serv->sv_cb_lock);
- finish_wait(&serv->sv_cb_waitq, &wq);
- svc_process_bc(req, rqstp);
- } else {
- spin_unlock_bh(&serv->sv_cb_lock);
- if (!kthread_should_stop())
- schedule();
- finish_wait(&serv->sv_cb_waitq, &wq);
- }
- }
-
- svc_exit_thread(rqstp);
- return 0;
-}
-
static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
struct svc_serv *serv)
{
@@ -233,10 +198,7 @@ static struct svc_serv *nfs_callback_create_svc(int minorversion)
cb_info->users);
threadfn = nfs4_callback_svc;
-#if defined(CONFIG_NFS_V4_1)
- if (minorversion)
- threadfn = nfs41_callback_svc;
-#else
+#if !defined(CONFIG_NFS_V4_1)
if (minorversion)
return ERR_PTR(-ENOTSUPP);
#endif
diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h
index 0cdca5960171..acbe1314febd 100644
--- a/include/linux/sunrpc/svc.h
+++ b/include/linux/sunrpc/svc.h
@@ -92,8 +92,6 @@ struct svc_serv {
* that arrive over the same
* connection */
spinlock_t sv_cb_lock; /* protects the svc_cb_list */
- wait_queue_head_t sv_cb_waitq; /* sleep here if there are no
- * entries in the svc_cb_list */
bool sv_bc_enabled; /* service uses backchannel */
#endif /* CONFIG_SUNRPC_BACKCHANNEL */
};
diff --git a/net/sunrpc/backchannel_rqst.c b/net/sunrpc/backchannel_rqst.c
index 65a6c6429a53..44b7c89a635f 100644
--- a/net/sunrpc/backchannel_rqst.c
+++ b/net/sunrpc/backchannel_rqst.c
@@ -349,10 +349,8 @@ struct rpc_rqst *xprt_lookup_bc_request(struct rpc_xprt *xprt, __be32 xid)
}
/*
- * Add callback request to callback list. The callback
- * service sleeps on the sv_cb_waitq waiting for new
- * requests. Wake it up after adding enqueing the
- * request.
+ * Add callback request to callback list. Wake a thread
+ * on the first pool (usually the only pool) to handle it.
*/
void xprt_complete_bc_request(struct rpc_rqst *req, uint32_t copied)
{
@@ -371,6 +369,6 @@ void xprt_complete_bc_request(struct rpc_rqst *req, uint32_t copied)
xprt_get(xprt);
spin_lock(&bc_serv->sv_cb_lock);
list_add(&req->rq_bc_list, &bc_serv->sv_cb_list);
- wake_up(&bc_serv->sv_cb_waitq);
spin_unlock(&bc_serv->sv_cb_lock);
+ svc_pool_wake_idle_thread(&bc_serv->sv_pools[0]);
}
diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
index a3d031deb1ec..b98a159eb17f 100644
--- a/net/sunrpc/svc.c
+++ b/net/sunrpc/svc.c
@@ -440,7 +440,6 @@ __svc_init_bc(struct svc_serv *serv)
{
INIT_LIST_HEAD(&serv->sv_cb_list);
spin_lock_init(&serv->sv_cb_lock);
- init_waitqueue_head(&serv->sv_cb_waitq);
}
#else
static void
@@ -718,6 +717,7 @@ void svc_pool_wake_idle_thread(struct svc_pool *pool)
set_bit(SP_CONGESTED, &pool->sp_flags);
}
+EXPORT_SYMBOL_GPL(svc_pool_wake_idle_thread);
static struct svc_pool *
svc_pool_next(struct svc_serv *serv, struct svc_pool *pool, unsigned int *state)
diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
index 835160da3ad4..b057f1cbe7a1 100644
--- a/net/sunrpc/svc_xprt.c
+++ b/net/sunrpc/svc_xprt.c
@@ -17,6 +17,7 @@
#include <linux/sunrpc/svc_xprt.h>
#include <linux/sunrpc/svcsock.h>
#include <linux/sunrpc/xprt.h>
+#include <linux/sunrpc/bc_xprt.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <trace/events/sunrpc.h>
@@ -719,6 +720,13 @@ rqst_should_sleep(struct svc_rqst *rqstp)
if (freezing(current))
return false;
+#if defined(CONFIG_SUNRPC_BACKCHANNEL)
+ if (svc_is_backchannel(rqstp)) {
+ if (!list_empty(&rqstp->rq_server->sv_cb_list))
+ return false;
+ }
+#endif
+
return true;
}
@@ -868,6 +876,25 @@ void svc_recv(struct svc_rqst *rqstp)
trace_svc_xprt_dequeue(rqstp);
svc_handle_xprt(rqstp, xprt);
}
+
+#if defined(CONFIG_SUNRPC_BACKCHANNEL)
+ if (svc_is_backchannel(rqstp)) {
+ struct svc_serv *serv = rqstp->rq_server;
+ struct rpc_rqst *req;
+
+ spin_lock_bh(&serv->sv_cb_lock);
+ req = list_first_entry_or_null(&serv->sv_cb_list,
+ struct rpc_rqst, rq_bc_list);
+ if (req) {
+ list_del(&req->rq_bc_list);
+ spin_unlock_bh(&serv->sv_cb_lock);
+
+ svc_process_bc(req, rqstp);
+ return;
+ }
+ spin_unlock_bh(&serv->sv_cb_lock);
+ }
+#endif
}
EXPORT_SYMBOL_GPL(svc_recv);
diff --git a/net/sunrpc/xprtrdma/backchannel.c b/net/sunrpc/xprtrdma/backchannel.c
index e4d84a13c566..bfc434ec52a7 100644
--- a/net/sunrpc/xprtrdma/backchannel.c
+++ b/net/sunrpc/xprtrdma/backchannel.c
@@ -267,7 +267,7 @@ void rpcrdma_bc_receive_call(struct rpcrdma_xprt *r_xprt,
list_add(&rqst->rq_bc_list, &bc_serv->sv_cb_list);
spin_unlock(&bc_serv->sv_cb_lock);
- wake_up(&bc_serv->sv_cb_waitq);
+ svc_pool_wake_idle_thread(&bc_serv->sv_pools[0]);
r_xprt->rx_stats.bcall_count++;
return;
