lockd: move lockd's grace period handling into its own module

Currently, all of the grace period handling is part of lockd. Eventually
though we'd like to be able to build v4-only servers, at which point
we'll need to put all of this elsewhere.

Move the code itself into fs/nfs_common and have it build a grace.ko
module. Then, rejigger the Kconfig options so that both nfsd and lockd
enable it automatically.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>

8 files changed, 70 insertions, 15 deletions

diff --git a/fs/Kconfig b/fs/Kconfig
index 312393f32948..db5dc1598716 100644
--- a/fs/Kconfig
+++ b/fs/Kconfig
@@ -233,9 +233,13 @@ if NETWORK_FILESYSTEMS
 source "fs/nfs/Kconfig"
 source "fs/nfsd/Kconfig"
 
+config GRACE_PERIOD
+        tristate
+
 config LOCKD
         tristate
         depends on FILE_LOCKING
+        select GRACE_PERIOD
 
 config LOCKD_V4
         bool
@@ -249,7 +253,7 @@ config NFS_ACL_SUPPORT
 
 config NFS_COMMON
         bool
-        depends on NFSD || NFS_FS
+        depends on NFSD || NFS_FS || LOCKD
         default y
 
 source "net/sunrpc/Kconfig"
diff --git a/fs/lockd/Makefile b/fs/lockd/Makefile
index ca58d64374ca..6a0b351ce30e 100644
--- a/fs/lockd/Makefile
+++ b/fs/lockd/Makefile
@@ -5,6 +5,6 @@
 obj-$(CONFIG_LOCKD) += lockd.o
 
 lockd-objs-y := clntlock.o clntproc.o clntxdr.o host.o svc.o svclock.o \
-                svcshare.o svcproc.o svcsubs.o mon.o xdr.o grace.o
+                svcshare.o svcproc.o svcsubs.o mon.o xdr.o
 lockd-objs-$(CONFIG_LOCKD_V4) += clnt4xdr.o xdr4.o svc4proc.o
 lockd-objs                    := $(lockd-objs-y)
diff --git a/fs/lockd/netns.h b/fs/lockd/netns.h
index 5010b55628b4..097bfa3adb1c 100644
--- a/fs/lockd/netns.h
+++ b/fs/lockd/netns.h
@@ -11,7 +11,6 @@ struct lockd_net {
 
         struct delayed_work grace_period_end;
         struct lock_manager lockd_manager;
-        struct list_head grace_list;
 
         spinlock_t nsm_clnt_lock;
         unsigned int nsm_users;
diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c
index 09857b48d0c3..266b67972305 100644
--- a/fs/lockd/svc.c
+++ b/fs/lockd/svc.c
@@ -586,7 +586,7 @@ static int lockd_init_net(struct net *net)
         struct lockd_net *ln = net_generic(net, lockd_net_id);
 
         INIT_DELAYED_WORK(&ln->grace_period_end, grace_ender);
-        INIT_LIST_HEAD(&ln->grace_list);
+        INIT_LIST_HEAD(&ln->lockd_manager.list);
         spin_lock_init(&ln->nsm_clnt_lock);
         return 0;
 }
diff --git a/fs/nfs_common/Makefile b/fs/nfs_common/Makefile
index f689ed82af3a..d153ca3ea577 100644
--- a/fs/nfs_common/Makefile
+++ b/fs/nfs_common/Makefile
@@ -3,5 +3,6 @@
 #
 
 obj-$(CONFIG_NFS_ACL_SUPPORT) += nfs_acl.o
-
 nfs_acl-objs := nfsacl.o
+
+obj-$(CONFIG_GRACE_PERIOD) += grace.o
diff --git a/fs/lockd/grace.c b/fs/nfs_common/grace.c
index 6d1ee7204c88..ae6e58ea4de5 100644
--- a/fs/lockd/grace.c
+++ b/fs/nfs_common/grace.c
@@ -1,17 +1,20 @@
 /*
  * Common code for control of lockd and nfsv4 grace periods.
+ *
+ * Transplanted from lockd code
  */
 
 #include <linux/module.h>
-#include <linux/lockd/bind.h>
 #include <net/net_namespace.h>
+#include <net/netns/generic.h>
+#include <linux/fs.h>
 
-#include "netns.h"
-
+static int grace_net_id;
 static DEFINE_SPINLOCK(grace_lock);
 
 /**
  * locks_start_grace
+ * @net: net namespace that this lock manager belongs to
  * @lm: who this grace period is for
  *
  * A grace period is a period during which locks should not be given
@@ -21,18 +24,20 @@ static DEFINE_SPINLOCK(grace_lock);
  *
  * This function is called to start a grace period.
  */
-void locks_start_grace(struct net *net, struct lock_manager *lm)
+void
+locks_start_grace(struct net *net, struct lock_manager *lm)
 {
-        struct lockd_net *ln = net_generic(net, lockd_net_id);
+        struct list_head *grace_list = net_generic(net, grace_net_id);
 
         spin_lock(&grace_lock);
-        list_add(&lm->list, &ln->grace_list);
+        list_add(&lm->list, grace_list);
         spin_unlock(&grace_lock);
 }
 EXPORT_SYMBOL_GPL(locks_start_grace);
 
 /**
  * locks_end_grace
+ * @net: net namespace that this lock manager belongs to
  * @lm: who this grace period is for
  *
  * Call this function to state that the given lock manager is ready to
@@ -41,7 +46,8 @@ EXPORT_SYMBOL_GPL(locks_start_grace);
  * Note that callers count on it being safe to call this more than once,
  * and the second call should be a no-op.
  */
-void locks_end_grace(struct lock_manager *lm)
+void
+locks_end_grace(struct lock_manager *lm)
 {
         spin_lock(&grace_lock);
         list_del_init(&lm->list);
@@ -56,10 +62,52 @@ EXPORT_SYMBOL_GPL(locks_end_grace);
  * to answer ordinary lock requests, and when they should accept only
  * lock reclaims.
  */
-int locks_in_grace(struct net *net)
+int
+locks_in_grace(struct net *net)
 {
-        struct lockd_net *ln = net_generic(net, lockd_net_id);
+        struct list_head *grace_list = net_generic(net, grace_net_id);
 
-        return !list_empty(&ln->grace_list);
+        return !list_empty(grace_list);
 }
 EXPORT_SYMBOL_GPL(locks_in_grace);
+
+static int __net_init
+grace_init_net(struct net *net)
+{
+        struct list_head *grace_list = net_generic(net, grace_net_id);
+
+        INIT_LIST_HEAD(grace_list);
+        return 0;
+}
+
+static void __net_exit
+grace_exit_net(struct net *net)
+{
+        struct list_head *grace_list = net_generic(net, grace_net_id);
+
+        BUG_ON(!list_empty(grace_list));
+}
+
+static struct pernet_operations grace_net_ops = {
+        .init = grace_init_net,
+        .exit = grace_exit_net,
+        .id   = &grace_net_id,
+        .size = sizeof(struct list_head),
+};
+
+static int __init
+init_grace(void)
+{
+        return register_pernet_subsys(&grace_net_ops);
+}
+
+static void __exit
+exit_grace(void)
+{
+        unregister_pernet_subsys(&grace_net_ops);
+}
+
+MODULE_AUTHOR("Jeff Layton <jlayton@primarydata.com>");
+MODULE_LICENSE("GPL");
+module_init(init_grace)
+module_exit(exit_grace)
diff --git a/fs/nfsd/Kconfig b/fs/nfsd/Kconfig
index f3586b645d7d..73395156bdb4 100644
--- a/fs/nfsd/Kconfig
+++ b/fs/nfsd/Kconfig
@@ -71,6 +71,7 @@ config NFSD_V4
         select FS_POSIX_ACL
         select SUNRPC_GSS
         select CRYPTO
+        select GRACE_PERIOD
         help
           This option enables support in your system's NFS server for
           version 4 of the NFS protocol (RFC 3530).
diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h
index 9d117f61d976..b97bf2ef996e 100644
--- a/include/linux/proc_fs.h
+++ b/include/linux/proc_fs.h
@@ -74,6 +74,8 @@ static inline int remove_proc_subtree(const char *name, struct proc_dir_entry *p
 
 #endif /* CONFIG_PROC_FS */
 
+struct net;
+
 static inline struct proc_dir_entry *proc_net_mkdir(
         struct net *net, const char *name, struct proc_dir_entry *parent)
 {