svc_recv() currently returns a 0 on success or one of two errors:
- -EAGAIN means no message was successfully received
- -EINTR means the thread has been told to stop
Previously nfsd would stop as the result of a signal as well as
following kthread_stop(). In that case the difference was useful: EINTR
means stop unconditionally. EAGAIN means stop if kthread_should_stop(),
continue otherwise.
Now threads only exit when kthread_should_stop() so we don't need the
distinction.
So have all threads test kthread_should_stop() (most do), and return
simple success/failure from svc_recv().
Also change some helpers that svc_recv() uses to not bother with an
error code, returning a bool in once case, and NULL for failure in
another.
Signed-off-by: NeilBrown <neilb@xxxxxxx>
---
fs/lockd/svc.c | 9 +++------
fs/nfs/callback.c | 5 +----
fs/nfsd/nfssvc.c | 8 ++------
include/linux/sunrpc/svcsock.h | 2 +-
net/sunrpc/svc_xprt.c | 27 +++++++++++----------------
5 files changed, 18 insertions(+), 33 deletions(-)
diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c
index 91ef139a7757..a43b63e46127 100644
--- a/fs/lockd/svc.c
+++ b/fs/lockd/svc.c
@@ -116,7 +116,6 @@ static void set_grace_period(struct net *net)
static int
lockd(void *vrqstp)
{
- int err = 0;
struct svc_rqst *rqstp = vrqstp;
struct net *net = &init_net;
struct lockd_net *ln = net_generic(net, lockd_net_id);
@@ -139,12 +138,10 @@ lockd(void *vrqstp)
timeout = nlmsvc_retry_blocked();
/*
- * Find a socket with data available and call its
- * recvfrom routine.
+ * Find any work to do, such as a socket with data available,
+ * and do the work.
*/
- err = svc_recv(rqstp, timeout);
- if (err == -EAGAIN || err == -EINTR)
- continue;
+ svc_recv(rqstp, timeout);
}
if (nlmsvc_ops)
nlmsvc_invalidate_all();
diff --git a/fs/nfs/callback.c b/fs/nfs/callback.c
index 2d94384bd6a9..914d2402ca98 100644
--- a/fs/nfs/callback.c
+++ b/fs/nfs/callback.c
@@ -74,7 +74,6 @@ static int nfs4_callback_up_net(struct svc_serv *serv, struct net *net)
static int
nfs4_callback_svc(void *vrqstp)
{
- int err;
struct svc_rqst *rqstp = vrqstp;
set_freezable();
@@ -83,9 +82,7 @@ nfs4_callback_svc(void *vrqstp)
/*
* Listen for a request on the socket
*/
- err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT);
- if (err == -EAGAIN || err == -EINTR)
- continue;
+ svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT);
}
svc_exit_thread(rqstp);
diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
index 3e08cc746870..5bf48c33986e 100644
--- a/fs/nfsd/nfssvc.c
+++ b/fs/nfsd/nfssvc.c
@@ -953,7 +953,6 @@ nfsd(void *vrqstp)
struct svc_xprt *perm_sock = list_entry(rqstp->rq_server->sv_permsocks.next, typeof(struct svc_xprt), xpt_list);
struct net *net = perm_sock->xpt_net;
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
- int err;
/* At this point, the thread shares current->fs
* with the init process. We need to create files with the
@@ -972,7 +971,7 @@ nfsd(void *vrqstp)
/*
* The main request loop
*/
- for (;;) {
+ while (!kthread_should_stop()) {
/* Update sv_maxconn if it has changed */
rqstp->rq_server->sv_maxconn = nn->max_connections;
@@ -980,10 +979,7 @@ nfsd(void *vrqstp)
* Find a socket with data available and call its
* recvfrom routine.
*/
- while ((err = svc_recv(rqstp, 60*60*HZ)) == -EAGAIN)
- ;
- if (err == -EINTR)
- break;
+ svc_recv(rqstp, 60*60*HZ);
validate_process_creds();
}
diff --git a/include/linux/sunrpc/svcsock.h b/include/linux/sunrpc/svcsock.h
index 55446136499f..fb5c98069356 100644
--- a/include/linux/sunrpc/svcsock.h
+++ b/include/linux/sunrpc/svcsock.h
@@ -64,7 +64,7 @@ static inline u32 svc_sock_final_rec(struct svc_sock *svsk)
* Function prototypes.
*/
void svc_close_net(struct svc_serv *, struct net *);
-int svc_recv(struct svc_rqst *, long);
+void svc_recv(struct svc_rqst *, long);
void svc_send(struct svc_rqst *rqstp);
void svc_drop(struct svc_rqst *);
void svc_sock_update_bufs(struct svc_serv *serv);
diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
index c808f6d60c99..67825eef8646 100644
--- a/net/sunrpc/svc_xprt.c
+++ b/net/sunrpc/svc_xprt.c
@@ -664,7 +664,7 @@ static void svc_check_conn_limits(struct svc_serv *serv)
}
}
-static int svc_alloc_arg(struct svc_rqst *rqstp)
+static bool svc_alloc_arg(struct svc_rqst *rqstp)
{
struct svc_serv *serv = rqstp->rq_server;
struct xdr_buf *arg = &rqstp->rq_arg;
@@ -689,7 +689,7 @@ static int svc_alloc_arg(struct svc_rqst *rqstp)
set_current_state(TASK_IDLE);
if (kthread_should_stop()) {
set_current_state(TASK_RUNNING);
- return -EINTR;
+ return false;
}
trace_svc_alloc_arg_err(pages, ret);
memalloc_retry_wait(GFP_KERNEL);
@@ -708,7 +708,7 @@ static int svc_alloc_arg(struct svc_rqst *rqstp)
arg->tail[0].iov_len = 0;
rqstp->rq_xid = xdr_zero;
- return 0;
+ return true;
}
static bool
@@ -773,9 +773,9 @@ static struct svc_xprt *svc_get_next_xprt(struct svc_rqst *rqstp, long timeout)
if (!time_left)
percpu_counter_inc(&pool->sp_threads_timedout);
if (kthread_should_stop())
- return ERR_PTR(-EINTR);
+ return NULL;
percpu_counter_inc(&pool->sp_threads_no_work);
- return ERR_PTR(-EAGAIN);
+ return NULL;
out_found:
/* Normally we will wait up to 5 seconds for any required
* cache information to be provided.
@@ -856,32 +856,27 @@ static int svc_handle_xprt(struct svc_rqst *rqstp, struct svc_xprt *xprt)
* organised not to touch any cachelines in the shared svc_serv
* structure, only cachelines in the local svc_pool.
*/
-int svc_recv(struct svc_rqst *rqstp, long timeout)
+void svc_recv(struct svc_rqst *rqstp, long timeout)
{
struct svc_xprt *xprt = NULL;
struct svc_serv *serv = rqstp->rq_server;
- int len, err;
+ int len;
- err = svc_alloc_arg(rqstp);
- if (err)
+ if (!svc_alloc_arg(rqstp))
goto out;
try_to_freeze();
cond_resched();
- err = -EINTR;
if (kthread_should_stop())
goto out;
xprt = svc_get_next_xprt(rqstp, timeout);
- if (IS_ERR(xprt)) {
- err = PTR_ERR(xprt);
+ if (!xprt)
goto out;
- }
len = svc_handle_xprt(rqstp, xprt);
/* No data, incomplete (TCP) read, or accept() */
- err = -EAGAIN;
if (len <= 0)
goto out_release;
@@ -896,12 +891,12 @@ int svc_recv(struct svc_rqst *rqstp, long timeout)
percpu_counter_inc(&rqstp->rq_pool->sp_messages_arrived);
rqstp->rq_stime = ktime_get();
svc_process(rqstp);
- return 0;
+ return;
out_release:
rqstp->rq_res.len = 0;
svc_xprt_release(rqstp);
out:
- return err;
+ return;
}
EXPORT_SYMBOL_GPL(svc_recv);
