[PATCH v3 09/11] NFS; callback per-net usage counting introduced

Stanislav Kinsbursky
2012-07-03T16:23:44Z

This patch also introduces refcount-aware nfs_callback_down_net() wrapper for
svc_shutdown_net().

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
---
fs/nfs/callback.c | 19 +++++++++++++++++--
fs/nfs/netns.h | 1 +
2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/fs/nfs/callback.c b/fs/nfs/callback.c
index 97bccb1..35ccd2a 100644
--- a/fs/nfs/callback.c
+++ b/fs/nfs/callback.c
@@ -284,10 +284,25 @@ static int nfs_callback_start_svc(int minorversion, struct rpc_xprt *xprt,
return 0;
}

+static void nfs_callback_down_net(u32 minorversion, struct svc_serv *serv, struct net *net)
+{
+ struct nfs_net *nn = net_generic(net, nfs_net_id);
+
+ if (--nn->cb_users[minorversion])
+ return;
+
+ dprintk("NFS: destroy per-net callback data; net=%p\n", net);
+ svc_shutdown_net(serv, net);
+}
+
static int nfs_callback_up_net(int minorversion, struct svc_serv *serv, struct net *net)
{
+ struct nfs_net *nn = net_generic(net, nfs_net_id);
int ret;

+ if (nn->cb_users[minorversion]++)
+ return 0;
+
dprintk("NFS: create per-net callback data; net=%p\n", net);

ret = svc_bind(serv, net);
@@ -390,7 +405,7 @@ err_create:
return ret;

err_start:
- svc_shutdown_net(serv, net);
+ nfs_callback_down_net(minorversion, serv, net);
dprintk("NFS: Couldn't create server thread; err = %d\n", ret);
goto err_net;
}
@@ -403,10 +418,10 @@ void nfs_callback_down(int minorversion, struct net *net)
struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];

mutex_lock(&nfs_callback_mutex);
+ nfs_callback_down_net(minorversion, cb_info->serv, net);
cb_info->users--;
if (cb_info->users == 0 && cb_info->task != NULL) {
kthread_stop(cb_info->task);
- svc_shutdown_net(cb_info->serv, net);
svc_exit_thread(cb_info->rqst);
cb_info->serv = NULL;
cb_info->rqst = NULL;
diff --git a/fs/nfs/netns.h b/fs/nfs/netns.h
index 097dae1..b015ab8 100644
--- a/fs/nfs/netns.h
+++ b/fs/nfs/netns.h
@@ -24,6 +24,7 @@ struct nfs_net {
struct idr cb_ident_idr; /* Protected by nfs_client_lock */
unsigned short nfs_callback_tcpport;
unsigned short nfs_callback_tcpport6;
+ int cb_users[NFS4_MAX_MINOR_VERSION + 1];
#endif
spinlock_t nfs_client_lock;
struct timespec boot_time;