5 files changed, 77 insertions, 28 deletions

diff --git a/fs/lockd/Makefile b/fs/lockd/Makefile
index 7725a0a9a555..97f6073ab339 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 host.o svc.o svclock.o svcshare.o \
-                svcproc.o svcsubs.o mon.o xdr.o
+                svcproc.o svcsubs.o mon.o xdr.o grace.o
 lockd-objs-$(CONFIG_LOCKD_V4) += xdr4.o svc4proc.o
 lockd-objs                    := $(lockd-objs-y)
diff --git a/fs/lockd/grace.c b/fs/lockd/grace.c
new file mode 100644
index 000000000000..183cc1f0af1c
--- /dev/null
+++ b/fs/lockd/grace.c
@@ -0,0 +1,59 @@
+/*
+ * Common code for control of lockd and nfsv4 grace periods.
+ */
+
+#include <linux/module.h>
+#include <linux/lockd/bind.h>
+
+static LIST_HEAD(grace_list);
+static DEFINE_SPINLOCK(grace_lock);
+
+/**
+ * locks_start_grace
+ * @lm: who this grace period is for
+ *
+ * A grace period is a period during which locks should not be given
+ * out.  Currently grace periods are only enforced by the two lock
+ * managers (lockd and nfsd), using the locks_in_grace() function to
+ * check when they are in a grace period.
+ *
+ * This function is called to start a grace period.
+ */
+void locks_start_grace(struct lock_manager *lm)
+{
+        spin_lock(&grace_lock);
+        list_add(&lm->list, &grace_list);
+        spin_unlock(&grace_lock);
+}
+EXPORT_SYMBOL_GPL(locks_start_grace);
+
+/**
+ * locks_end_grace
+ * @lm: who this grace period is for
+ *
+ * Call this function to state that the given lock manager is ready to
+ * resume regular locking.  The grace period will not end until all lock
+ * managers that called locks_start_grace() also call locks_end_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)
+{
+        spin_lock(&grace_lock);
+        list_del_init(&lm->list);
+        spin_unlock(&grace_lock);
+}
+EXPORT_SYMBOL_GPL(locks_end_grace);
+
+/**
+ * locks_in_grace
+ *
+ * Lock managers call this function to determine when it is OK for them
+ * to answer ordinary lock requests, and when they should accept only
+ * lock reclaims.
+ */
+int locks_in_grace(void)
+{
+        return !list_empty(&grace_list);
+}
+EXPORT_SYMBOL_GPL(locks_in_grace);
diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c
index f345ef7fb8ae..f013aed11533 100644
--- a/fs/lockd/svc.c
+++ b/fs/lockd/svc.c
@@ -51,7 +51,6 @@ static DEFINE_MUTEX(nlmsvc_mutex);
 static unsigned int             nlmsvc_users;
 static struct task_struct       *nlmsvc_task;
 static struct svc_rqst          *nlmsvc_rqst;
-int                             nlmsvc_grace_period;
 unsigned long                   nlmsvc_timeout;
 
 /*
@@ -85,30 +84,21 @@ static unsigned long get_lockd_grace_period(void)
                 return nlm_timeout * 5 * HZ;
 }
 
-unsigned long get_nfs_grace_period(void)
-{
-        unsigned long lockdgrace = get_lockd_grace_period();
-        unsigned long nfsdgrace = 0;
-
-        if (nlmsvc_ops)
-                nfsdgrace = nlmsvc_ops->get_grace_period();
-
-        return max(lockdgrace, nfsdgrace);
-}
-EXPORT_SYMBOL(get_nfs_grace_period);
+static struct lock_manager lockd_manager = {
+};
 
 static void grace_ender(struct work_struct *not_used)
 {
-        nlmsvc_grace_period = 0;
+        locks_end_grace(&lockd_manager);
 }
 
 static DECLARE_DELAYED_WORK(grace_period_end, grace_ender);
 
 static void set_grace_period(void)
 {
-        unsigned long grace_period = get_nfs_grace_period() + jiffies;
+        unsigned long grace_period = get_lockd_grace_period();
 
-        nlmsvc_grace_period = 1;
+        locks_start_grace(&lockd_manager);
         cancel_delayed_work_sync(&grace_period_end);
         schedule_delayed_work(&grace_period_end, grace_period);
 }
diff --git a/fs/lockd/svc4proc.c b/fs/lockd/svc4proc.c
index 4a714f64515b..7ca617367b3e 100644
--- a/fs/lockd/svc4proc.c
+++ b/fs/lockd/svc4proc.c
@@ -89,7 +89,7 @@ nlm4svc_proc_test(struct svc_rqst *rqstp, struct nlm_args *argp,
         resp->cookie = argp->cookie;
 
         /* Don't accept test requests during grace period */
-        if (nlmsvc_grace_period) {
+        if (locks_in_grace()) {
                 resp->status = nlm_lck_denied_grace_period;
                 return rc;
         }
@@ -123,7 +123,7 @@ nlm4svc_proc_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
         resp->cookie = argp->cookie;
 
         /* Don't accept new lock requests during grace period */
-        if (nlmsvc_grace_period && !argp->reclaim) {
+        if (locks_in_grace() && !argp->reclaim) {
                 resp->status = nlm_lck_denied_grace_period;
                 return rc;
         }
@@ -169,7 +169,7 @@ nlm4svc_proc_cancel(struct svc_rqst *rqstp, struct nlm_args *argp,
         resp->cookie = argp->cookie;
 
         /* Don't accept requests during grace period */
-        if (nlmsvc_grace_period) {
+        if (locks_in_grace()) {
                 resp->status = nlm_lck_denied_grace_period;
                 return rpc_success;
         }
@@ -202,7 +202,7 @@ nlm4svc_proc_unlock(struct svc_rqst *rqstp, struct nlm_args *argp,
         resp->cookie = argp->cookie;
 
         /* Don't accept new lock requests during grace period */
-        if (nlmsvc_grace_period) {
+        if (locks_in_grace()) {
                 resp->status = nlm_lck_denied_grace_period;
                 return rpc_success;
         }
@@ -341,7 +341,7 @@ nlm4svc_proc_share(struct svc_rqst *rqstp, struct nlm_args *argp,
         resp->cookie = argp->cookie;
 
         /* Don't accept new lock requests during grace period */
-        if (nlmsvc_grace_period && !argp->reclaim) {
+        if (locks_in_grace() && !argp->reclaim) {
                 resp->status = nlm_lck_denied_grace_period;
                 return rpc_success;
         }
@@ -374,7 +374,7 @@ nlm4svc_proc_unshare(struct svc_rqst *rqstp, struct nlm_args *argp,
         resp->cookie = argp->cookie;
 
         /* Don't accept requests during grace period */
-        if (nlmsvc_grace_period) {
+        if (locks_in_grace()) {
                 resp->status = nlm_lck_denied_grace_period;
                 return rpc_success;
         }
diff --git a/fs/lockd/svcproc.c b/fs/lockd/svcproc.c
index 76262c1986f2..1b013e198804 100644
--- a/fs/lockd/svcproc.c
+++ b/fs/lockd/svcproc.c
@@ -118,7 +118,7 @@ nlmsvc_proc_test(struct svc_rqst *rqstp, struct nlm_args *argp,
         resp->cookie = argp->cookie;
 
         /* Don't accept test requests during grace period */
-        if (nlmsvc_grace_period) {
+        if (locks_in_grace()) {
                 resp->status = nlm_lck_denied_grace_period;
                 return rc;
         }
@@ -153,7 +153,7 @@ nlmsvc_proc_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
         resp->cookie = argp->cookie;
 
         /* Don't accept new lock requests during grace period */
-        if (nlmsvc_grace_period && !argp->reclaim) {
+        if (locks_in_grace() && !argp->reclaim) {
                 resp->status = nlm_lck_denied_grace_period;
                 return rc;
         }
@@ -199,7 +199,7 @@ nlmsvc_proc_cancel(struct svc_rqst *rqstp, struct nlm_args *argp,
         resp->cookie = argp->cookie;
 
         /* Don't accept requests during grace period */
-        if (nlmsvc_grace_period) {
+        if (locks_in_grace()) {
                 resp->status = nlm_lck_denied_grace_period;
                 return rpc_success;
         }
@@ -232,7 +232,7 @@ nlmsvc_proc_unlock(struct svc_rqst *rqstp, struct nlm_args *argp,
         resp->cookie = argp->cookie;
 
         /* Don't accept new lock requests during grace period */
-        if (nlmsvc_grace_period) {
+        if (locks_in_grace()) {
                 resp->status = nlm_lck_denied_grace_period;
                 return rpc_success;
         }
@@ -373,7 +373,7 @@ nlmsvc_proc_share(struct svc_rqst *rqstp, struct nlm_args *argp,
         resp->cookie = argp->cookie;
 
         /* Don't accept new lock requests during grace period */
-        if (nlmsvc_grace_period && !argp->reclaim) {
+        if (locks_in_grace() && !argp->reclaim) {
                 resp->status = nlm_lck_denied_grace_period;
                 return rpc_success;
         }
@@ -406,7 +406,7 @@ nlmsvc_proc_unshare(struct svc_rqst *rqstp, struct nlm_args *argp,
         resp->cookie = argp->cookie;
 
         /* Don't accept requests during grace period */
-        if (nlmsvc_grace_period) {
+        if (locks_in_grace()) {
                 resp->status = nlm_lck_denied_grace_period;
                 return rpc_success;
         }