5 files changed, 67 insertions, 65 deletions

diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index 4bc22c763de7..ed12ad40828b 100644
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -455,7 +455,7 @@ static struct rpc_program cb_program = {
 
 static int max_cb_time(void)
 {
-        return max(NFSD_LEASE_TIME/10, (time_t)1) * HZ;
+        return max(nfsd4_lease/10, (time_t)1) * HZ;
 }
 
 /* Reference counting, callback cleanup, etc., all look racy as heck.
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index c97fddbd17db..efef7f2442d5 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -44,8 +44,8 @@
 #define NFSDDBG_FACILITY                NFSDDBG_PROC
 
 /* Globals */
-static time_t lease_time = 90;     /* default lease time */
-static time_t user_lease_time = 90;
+time_t nfsd4_lease = 90;     /* default lease time */
+time_t nfsd4_grace = 90;
 static time_t boot_time;
 static u32 current_ownerid = 1;
 static u32 current_fileid = 1;
@@ -2553,6 +2553,12 @@ nfsd4_end_grace(void)
         dprintk("NFSD: end of grace period\n");
         nfsd4_recdir_purge_old();
         locks_end_grace(&nfsd4_manager);
+        /*
+         * Now that every NFSv4 client has had the chance to recover and
+         * to see the (possibly new, possibly shorter) lease time, we
+         * can safely set the next grace time to the current lease time:
+         */
+        nfsd4_grace = nfsd4_lease;
 }
 
 static time_t
@@ -2562,9 +2568,9 @@ nfs4_laundromat(void)
         struct nfs4_stateowner *sop;
         struct nfs4_delegation *dp;
         struct list_head *pos, *next, reaplist;
-        time_t cutoff = get_seconds() - NFSD_LEASE_TIME;
-        time_t t, clientid_val = NFSD_LEASE_TIME;
-        time_t u, test_val = NFSD_LEASE_TIME;
+        time_t cutoff = get_seconds() - nfsd4_lease;
+        time_t t, clientid_val = nfsd4_lease;
+        time_t u, test_val = nfsd4_lease;
 
         nfs4_lock_state();
 
@@ -2604,7 +2610,7 @@ nfs4_laundromat(void)
                 list_del_init(&dp->dl_recall_lru);
                 unhash_delegation(dp);
         }
-        test_val = NFSD_LEASE_TIME;
+        test_val = nfsd4_lease;
         list_for_each_safe(pos, next, &close_lru) {
                 sop = list_entry(pos, struct nfs4_stateowner, so_close_lru);
                 if (time_after((unsigned long)sop->so_time, (unsigned long)cutoff)) {
@@ -2674,7 +2680,7 @@ EXPIRED_STATEID(stateid_t *stateid)
 {
         if (time_before((unsigned long)boot_time,
                         ((unsigned long)stateid->si_boot)) &&
-            time_before((unsigned long)(stateid->si_boot + lease_time), get_seconds())) {
+            time_before((unsigned long)(stateid->si_boot + nfsd4_lease), get_seconds())) {
                 dprintk("NFSD: expired stateid " STATEID_FMT "!\n",
                         STATEID_VAL(stateid));
                 return 1;
@@ -3975,12 +3981,6 @@ nfsd4_load_reboot_recovery_data(void)
                 printk("NFSD: Failure reading reboot recovery data\n");
 }
 
-unsigned long
-get_nfs4_grace_period(void)
-{
-        return max(user_lease_time, lease_time) * HZ;
-}
-
 /*
  * Since the lifetime of a delegation isn't limited to that of an open, a
  * client may quite reasonably hang on to a delegation as long as it has
@@ -4007,18 +4007,14 @@ set_max_delegations(void)
 static int
 __nfs4_state_start(void)
 {
-        unsigned long grace_time;
-
         boot_time = get_seconds();
-        grace_time = get_nfs4_grace_period();
-        lease_time = user_lease_time;
         locks_start_grace(&nfsd4_manager);
         printk(KERN_INFO "NFSD: starting %ld-second grace period\n",
-               grace_time/HZ);
+               nfsd4_grace);
         laundry_wq = create_singlethread_workqueue("nfsd4");
         if (laundry_wq == NULL)
                 return -ENOMEM;
-        queue_delayed_work(laundry_wq, &laundromat_work, grace_time);
+        queue_delayed_work(laundry_wq, &laundromat_work, nfsd4_grace * HZ);
         set_max_delegations();
         return set_callback_cred();
 }
@@ -4038,12 +4034,6 @@ nfs4_state_start(void)
         return 0;
 }
 
-time_t
-nfs4_lease_time(void)
-{
-        return lease_time;
-}
-
 static void
 __nfs4_state_shutdown(void)
 {
@@ -4127,21 +4117,3 @@ nfs4_recoverydir(void)
 {
         return user_recovery_dirname;
 }
-
-/*
- * Called when leasetime is changed.
- *
- * The only way the protocol gives us to handle on-the-fly lease changes is to
- * simulate a reboot.  Instead of doing that, we just wait till the next time
- * we start to register any changes in lease time.  If the administrator
- * really wants to change the lease time *now*, they can go ahead and bring
- * nfsd down and then back up again after changing the lease time.
- *
- * user_lease_time is protected by nfsd_mutex since it's only really accessed
- * when nfsd is starting
- */
-void
-nfs4_reset_lease(time_t leasetime)
-{
-        user_lease_time = leasetime;
-}
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 78c7e24e5129..fb27b1db007b 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -1899,7 +1899,7 @@ nfsd4_encode_fattr(struct svc_fh *fhp, struct svc_export *exp,
         if (bmval0 & FATTR4_WORD0_LEASE_TIME) {
                 if ((buflen -= 4) < 0)
                         goto out_resource;
-                WRITE32(NFSD_LEASE_TIME);
+                WRITE32(nfsd4_lease);
         }
         if (bmval0 & FATTR4_WORD0_RDATTR_ERROR) {
                 if ((buflen -= 4) < 0)
diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index 0f0e77f2012f..413cb8ef951b 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -45,6 +45,7 @@ enum {
          */
 #ifdef CONFIG_NFSD_V4
         NFSD_Leasetime,
+        NFSD_Gracetime,
         NFSD_RecoveryDir,
 #endif
 };
@@ -69,6 +70,7 @@ static ssize_t write_ports(struct file *file, char *buf, size_t size);
 static ssize_t write_maxblksize(struct file *file, char *buf, size_t size);
 #ifdef CONFIG_NFSD_V4
 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);
 #endif
 
@@ -90,6 +92,7 @@ static ssize_t (*write_op[])(struct file *, char *, size_t) = {
         [NFSD_MaxBlkSize] = write_maxblksize,
 #ifdef CONFIG_NFSD_V4
         [NFSD_Leasetime] = write_leasetime,
+        [NFSD_Gracetime] = write_gracetime,
         [NFSD_RecoveryDir] = write_recoverydir,
 #endif
 };
@@ -1203,29 +1206,45 @@ static ssize_t write_maxblksize(struct file *file, char *buf, size_t size)
 }
 
 #ifdef CONFIG_NFSD_V4
-extern time_t nfs4_leasetime(void);
-
-static ssize_t __write_leasetime(struct file *file, char *buf, size_t size)
+static ssize_t __nfsd4_write_time(struct file *file, char *buf, size_t size, time_t *time)
 {
-        /* if size > 10 seconds, call
-         * nfs4_reset_lease() then write out the new lease (seconds) as reply
-         */
         char *mesg = buf;
-        int rv, lease;
+        int rv, i;
 
         if (size > 0) {
                 if (nfsd_serv)
                         return -EBUSY;
-                rv = get_int(&mesg, &lease);
+                rv = get_int(&mesg, &i);
                 if (rv)
                         return rv;
-                if (lease < 10 || lease > 3600)
+                /*
+                 * Some sanity checking.  We don't have a reason for
+                 * these particular numbers, but problems with the
+                 * extremes are:
+                 *      - Too short: the briefest network outage may
+                 *        cause clients to lose all their locks.  Also,
+                 *        the frequent polling may be wasteful.
+                 *      - Too long: do you really want reboot recovery
+                 *        to take more than an hour?  Or to make other
+                 *        clients wait an hour before being able to
+                 *        revoke a dead client's locks?
+                 */
+                if (i < 10 || i > 3600)
                         return -EINVAL;
-                nfs4_reset_lease(lease);
+                *time = i;
         }
 
-        return scnprintf(buf, SIMPLE_TRANSACTION_LIMIT, "%ld\n",
-                                                        nfs4_lease_time());
+        return scnprintf(buf, SIMPLE_TRANSACTION_LIMIT, "%ld\n", *time);
+}
+
+static ssize_t nfsd4_write_time(struct file *file, char *buf, size_t size, time_t *time)
+{
+        ssize_t rv;
+
+        mutex_lock(&nfsd_mutex);
+        rv = __nfsd4_write_time(file, buf, size, time);
+        mutex_unlock(&nfsd_mutex);
+        return rv;
 }
 
 /**
@@ -1251,12 +1270,22 @@ static ssize_t __write_leasetime(struct file *file, char *buf, size_t size)
  */
 static ssize_t write_leasetime(struct file *file, char *buf, size_t size)
 {
-        ssize_t rv;
+        return nfsd4_write_time(file, buf, size, &nfsd4_lease);
+}
 
-        mutex_lock(&nfsd_mutex);
-        rv = __write_leasetime(file, buf, size);
-        mutex_unlock(&nfsd_mutex);
-        return rv;
+/**
+ * write_gracetime - Set or report current NFSv4 grace period time
+ *
+ * As above, but sets the time of the NFSv4 grace period.
+ *
+ * Note this should never be set to less than the *previous*
+ * lease-period time, but we don't try to enforce this.  (In the common
+ * case (a new boot), we don't know what the previous lease time was
+ * anyway.)
+ */
+static ssize_t write_gracetime(struct file *file, char *buf, size_t size)
+{
+        return nfsd4_write_time(file, buf, size, &nfsd4_grace);
 }
 
 extern char *nfs4_recoverydir(void);
@@ -1350,6 +1379,7 @@ static int nfsd_fill_super(struct super_block * sb, void * data, int silent)
                 [NFSD_MaxBlkSize] = {"max_block_size", &transaction_ops, S_IWUSR|S_IRUGO},
 #ifdef CONFIG_NFSD_V4
                 [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},
 #endif
                 /* last one */ {""}
diff --git a/fs/nfsd/nfsd.h b/fs/nfsd/nfsd.h
index e942a1aaac92..72377761270e 100644
--- a/fs/nfsd/nfsd.h
+++ b/fs/nfsd/nfsd.h
@@ -82,7 +82,6 @@ int nfs4_state_init(void);
 void nfsd4_free_slabs(void);
 int nfs4_state_start(void);
 void nfs4_state_shutdown(void);
-time_t nfs4_lease_time(void);
 void nfs4_reset_lease(time_t leasetime);
 int nfs4_reset_recoverydir(char *recdir);
 #else
@@ -90,7 +89,6 @@ static inline int nfs4_state_init(void) { return 0; }
 static inline void nfsd4_free_slabs(void) { }
 static inline int nfs4_state_start(void) { return 0; }
 static inline void nfs4_state_shutdown(void) { }
-static inline time_t nfs4_lease_time(void) { return 0; }
 static inline void nfs4_reset_lease(time_t leasetime) { }
 static inline int nfs4_reset_recoverydir(char *recdir) { return 0; }
 #endif
@@ -229,6 +227,9 @@ extern struct timeval	nfssvc_boot;
 
 #ifdef CONFIG_NFSD_V4
 
+extern time_t nfsd4_lease;
+extern time_t nfsd4_grace;
+
 /* before processing a COMPOUND operation, we have to check that there
  * is enough space in the buffer for XDR encode to succeed.  otherwise,
  * we might process an operation with side effects, and be unable to
@@ -247,7 +248,6 @@ extern struct timeval	nfssvc_boot;
 #define COMPOUND_SLACK_SPACE            140    /* OP_GETFH */
 #define COMPOUND_ERR_SLACK_SPACE        12     /* OP_SETATTR */
 
-#define NFSD_LEASE_TIME                 (nfs4_lease_time())
 #define NFSD_LAUNDROMAT_MINTIMEOUT      10   /* seconds */
 
 /*