3 files changed, 49 insertions, 1 deletions

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 08fb273ad4e0..8f7ace5942be 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -4113,7 +4113,7 @@ out:
         return status;
 }
 
-static void
+void
 nfsd4_end_grace(struct nfsd_net *nn)
 {
         /* do nothing if grace period already ended */
diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index 4e042105fb6e..ca73ca79a0ee 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -49,6 +49,7 @@ enum {
         NFSD_Leasetime,
         NFSD_Gracetime,
         NFSD_RecoveryDir,
+        NFSD_V4EndGrace,
 #endif
 };
 
@@ -68,6 +69,7 @@ static ssize_t write_maxconn(struct file *file, char *buf, size_t size);
 static ssize_t write_leasetime(struct file *file, char *buf, size_t size);
 static ssize_t write_gracetime(struct file *file, char *buf, size_t size);
 static ssize_t write_recoverydir(struct file *file, char *buf, size_t size);
+static ssize_t write_v4_end_grace(struct file *file, char *buf, size_t size);
 #endif
 
 static ssize_t (*write_op[])(struct file *, char *, size_t) = {
@@ -84,6 +86,7 @@ static ssize_t (*write_op[])(struct file *, char *, size_t) = {
         [NFSD_Leasetime] = write_leasetime,
         [NFSD_Gracetime] = write_gracetime,
         [NFSD_RecoveryDir] = write_recoverydir,
+        [NFSD_V4EndGrace] = write_v4_end_grace,
 #endif
 };
 
@@ -1077,6 +1080,47 @@ static ssize_t write_recoverydir(struct file *file, char *buf, size_t size)
         return rv;
 }
 
+/**
+ * write_v4_end_grace - release grace period for nfsd's v4.x lock manager
+ *
+ * Input:
+ *                      buf:            ignored
+ *                      size:           zero
+ * OR
+ *
+ * Input:
+ *                      buf:            any value
+ *                      size:           non-zero length of C string in @buf
+ * Output:
+ *                      passed-in buffer filled with "Y" or "N" with a newline
+ *                      and NULL-terminated C string. This indicates whether
+ *                      the grace period has ended in the current net
+ *                      namespace. Return code is the size in bytes of the
+ *                      string. Writing a string that starts with 'Y', 'y', or
+ *                      '1' to the file will end the grace period for nfsd's v4
+ *                      lock manager.
+ */
+static ssize_t write_v4_end_grace(struct file *file, char *buf, size_t size)
+{
+        struct net *net = file->f_dentry->d_sb->s_fs_info;
+        struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+        if (size > 0) {
+                switch(buf[0]) {
+                case 'Y':
+                case 'y':
+                case '1':
+                        nfsd4_end_grace(nn);
+                        break;
+                default:
+                        return -EINVAL;
+                }
+        }
+
+        return scnprintf(buf, SIMPLE_TRANSACTION_LIMIT, "%c\n",
+                         nn->grace_ended ? 'Y' : 'N');
+}
+
 #endif
 
 /*----------------------------------------------------------------------------*/
@@ -1110,6 +1154,7 @@ static int nfsd_fill_super(struct super_block * sb, void * data, int silent)
                 [NFSD_Leasetime] = {"nfsv4leasetime", &transaction_ops, S_IWUSR|S_IRUSR},
                 [NFSD_Gracetime] = {"nfsv4gracetime", &transaction_ops, S_IWUSR|S_IRUSR},
                 [NFSD_RecoveryDir] = {"nfsv4recoverydir", &transaction_ops, S_IWUSR|S_IRUSR},
+                [NFSD_V4EndGrace] = {"v4_end_grace", &transaction_ops, S_IWUSR|S_IRUGO},
 #endif
                 /* last one */ {""}
         };
diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
index a5fa6909501e..854f0c574ccf 100644
--- a/fs/nfsd/state.h
+++ b/fs/nfsd/state.h
@@ -545,6 +545,9 @@ extern struct nfs4_client_reclaim *nfs4_client_to_reclaim(const char *name,
                                                         struct nfsd_net *nn);
 extern bool nfs4_has_reclaimed_state(const char *name, struct nfsd_net *nn);
 
+/* grace period management */
+void nfsd4_end_grace(struct nfsd_net *nn);
+
 /* nfs4recover operations */
 extern int nfsd4_client_tracking_init(struct net *net);
 extern void nfsd4_client_tracking_exit(struct net *net);