nfsd: use boottime for lease expiry calculation

A couple of time_t variables are only used to track the state of the
lease time and its expiration. The code correctly uses the 'time_after()'
macro to make this work on 32-bit architectures even beyond year 2038,
but the get_seconds() function and the time_t type itself are deprecated
as they behave inconsistently between 32-bit and 64-bit architectures
and often lead to code that is not y2038 safe.

As a minor issue, using get_seconds() leads to problems with concurrent
settimeofday() or clock_settime() calls, in the worst case timeout never
triggering after the time has been set backwards.

Change nfsd to use time64_t and ktime_get_boottime_seconds() here. This
is clearly excessive, as boottime by itself means we never go beyond 32
bits, but it does mean we handle this correctly and consistently without
having to worry about corner cases and should be no more expensive than
the previous implementation on 64-bit architectures.

The max_cb_time() function gets changed in order to avoid an expensive
64-bit division operation, but as the lease time is at most one hour,
there is no change in behavior.

Also do the same for server-to-server copy expiration time.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
[bfields@redhat.com: fix up copy expiration]
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h
index 29bbe28eda5350312362cdd3412676a1ea7f8aa6..2baf32311e0074c81b325cc1c0a6b1a25682494c 100644 (file)
--- a/fs/nfsd/netns.h
+++ b/fs/nfsd/netns.h
@@ -92,8 +92,8 @@ struct nfsd_net {
        bool in_grace;
        const struct nfsd4_client_tracking_ops *client_tracking_ops;
 
-       time_t nfsd4_lease;
-       time_t nfsd4_grace;
+       time64_t nfsd4_lease;
+       time64_t nfsd4_grace;
        bool somebody_reclaimed;
 
        bool track_reclaim_completes;

diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index 24534db87e8606ee9bb72520f4590d0bf462970d..c3b11a715082914c2bfee7be0d27a507be967fdd 100644 (file)
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -823,7 +823,16 @@ static const struct rpc_program cb_program = {
 static int max_cb_time(struct net *net)
 {
        struct nfsd_net *nn = net_generic(net, nfsd_net_id);
-       return max(nn->nfsd4_lease/10, (time_t)1) * HZ;
+
+       /*
+        * nfsd4_lease is set to at most one hour in __nfsd4_write_time,
+        * so we can use 32-bit math on it. Warn if that assumption
+        * ever stops being true.
+        */
+       if (WARN_ON_ONCE(nn->nfsd4_lease > 3600))
+               return 360 * HZ;
+
+       return max(((u32)nn->nfsd4_lease)/10, 1u) * HZ;
 }
 
 static struct workqueue_struct *callback_wq;

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index f680b1530f3842de53b678062a5d1482bf394d56..1ad68b49a1017bb9915d1ae8a0d82eacb53ed089 100644 (file)
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -171,7 +171,7 @@ renew_client_locked(struct nfs4_client *clp)
                        clp->cl_clientid.cl_boot,
                        clp->cl_clientid.cl_id);
        list_move_tail(&clp->cl_lru, &nn->client_lru);
-       clp->cl_time = get_seconds();
+       clp->cl_time = ktime_get_boottime_seconds();
 }
 
 static void put_client_renew_locked(struct nfs4_client *clp)
@@ -776,7 +776,7 @@ struct nfs4_cpntf_state *nfs4_alloc_init_cpntf_state(struct nfsd_net *nn,
        cps = kzalloc(sizeof(struct nfs4_cpntf_state), GFP_KERNEL);
        if (!cps)
                return NULL;
-       cps->cpntf_time = get_seconds();
+       cps->cpntf_time = ktime_get_boottime_seconds();
        refcount_set(&cps->cp_stateid.sc_count, 1);
        if (!nfs4_init_cp_state(nn, &cps->cp_stateid, NFS4_COPYNOTIFY_STID))
                goto out_free;
@@ -2661,7 +2661,7 @@ static struct nfs4_client *create_client(struct xdr_netobj name,
        gen_clid(clp, nn);
        kref_init(&clp->cl_nfsdfs.cl_ref);
        nfsd4_init_cb(&clp->cl_cb_null, clp, NULL, NFSPROC4_CLNT_CB_NULL);
-       clp->cl_time = get_seconds();
+       clp->cl_time = ktime_get_boottime_seconds();
        clear_bit(0, &clp->cl_cb_slot_busy);
        copy_verf(clp, verf);
        memcpy(&clp->cl_addr, sa, sizeof(struct sockaddr_storage));
@@ -4331,7 +4331,7 @@ move_to_close_lru(struct nfs4_ol_stateid *s, struct net *net)
        last = oo->oo_last_closed_stid;
        oo->oo_last_closed_stid = s;
        list_move_tail(&oo->oo_close_lru, &nn->close_lru);
-       oo->oo_time = get_seconds();
+       oo->oo_time = ktime_get_boottime_seconds();
        spin_unlock(&nn->client_lock);
        if (last)
                nfs4_put_stid(&last->st_stid);
@@ -4426,7 +4426,7 @@ static void nfsd4_cb_recall_prepare(struct nfsd4_callback *cb)
         */
        spin_lock(&state_lock);
        if (dp->dl_time == 0) {
-               dp->dl_time = get_seconds();
+               dp->dl_time = ktime_get_boottime_seconds();
                list_add_tail(&dp->dl_recall_lru, &nn->del_recall_lru);
        }
        spin_unlock(&state_lock);
@@ -5233,9 +5233,8 @@ nfsd4_end_grace(struct nfsd_net *nn)
  */
 static bool clients_still_reclaiming(struct nfsd_net *nn)
 {
-       unsigned long now = (unsigned long) ktime_get_real_seconds();
-       unsigned long double_grace_period_end = (unsigned long)nn->boot_time +
-                                          2 * (unsigned long)nn->nfsd4_lease;
+       time64_t double_grace_period_end = nn->boot_time +
+                                          2 * nn->nfsd4_lease;
 
        if (nn->track_reclaim_completes &&
                        atomic_read(&nn->nr_reclaim_complete) ==
@@ -5248,12 +5247,12 @@ static bool clients_still_reclaiming(struct nfsd_net *nn)
         * If we've given them *two* lease times to reclaim, and they're
         * still not done, give up:
         */
-       if (time_after(now, double_grace_period_end))
+       if (ktime_get_boottime_seconds() > double_grace_period_end)
                return false;
        return true;
 }
 
-static time_t
+static time64_t
 nfs4_laundromat(struct nfsd_net *nn)
 {
        struct nfs4_client *clp;
@@ -5262,8 +5261,8 @@ nfs4_laundromat(struct nfsd_net *nn)
        struct nfs4_ol_stateid *stp;
        struct nfsd4_blocked_lock *nbl;
        struct list_head *pos, *next, reaplist;
-       time_t cutoff = get_seconds() - nn->nfsd4_lease;
-       time_t t, new_timeo = nn->nfsd4_lease;
+       time64_t cutoff = ktime_get_boottime_seconds() - nn->nfsd4_lease;
+       time64_t t, new_timeo = nn->nfsd4_lease;
        struct nfs4_cpntf_state *cps;
        copy_stateid_t *cps_t;
        int i;
@@ -5282,8 +5281,7 @@ nfs4_laundromat(struct nfsd_net *nn)
        idr_for_each_entry(&nn->s2s_cp_stateids, cps_t, i) {
                cps = container_of(cps_t, struct nfs4_cpntf_state, cp_stateid);
                if (cps->cp_stateid.sc_type == NFS4_COPYNOTIFY_STID &&
-                               !time_after((unsigned long)cps->cpntf_time,
-                               (unsigned long)cutoff))
+                               cps->cpntf_time > cutoff)
                        _free_cpntf_state_locked(nn, cps);
        }
        spin_unlock(&nn->s2s_cp_lock);
@@ -5291,7 +5289,7 @@ nfs4_laundromat(struct nfsd_net *nn)
        spin_lock(&nn->client_lock);
        list_for_each_safe(pos, next, &nn->client_lru) {
                clp = list_entry(pos, struct nfs4_client, cl_lru);
-               if (time_after((unsigned long)clp->cl_time, (unsigned long)cutoff)) {
+               if (clp->cl_time > cutoff) {
                        t = clp->cl_time - cutoff;
                        new_timeo = min(new_timeo, t);
                        break;
@@ -5314,7 +5312,7 @@ nfs4_laundromat(struct nfsd_net *nn)
        spin_lock(&state_lock);
        list_for_each_safe(pos, next, &nn->del_recall_lru) {
                dp = list_entry (pos, struct nfs4_delegation, dl_recall_lru);
-               if (time_after((unsigned long)dp->dl_time, (unsigned long)cutoff)) {
+               if (dp->dl_time > cutoff) {
                        t = dp->dl_time - cutoff;
                        new_timeo = min(new_timeo, t);
                        break;
@@ -5334,8 +5332,7 @@ nfs4_laundromat(struct nfsd_net *nn)
        while (!list_empty(&nn->close_lru)) {
                oo = list_first_entry(&nn->close_lru, struct nfs4_openowner,
                                        oo_close_lru);
-               if (time_after((unsigned long)oo->oo_time,
-                              (unsigned long)cutoff)) {
+               if (oo->oo_time > cutoff) {
                        t = oo->oo_time - cutoff;
                        new_timeo = min(new_timeo, t);
                        break;
@@ -5365,8 +5362,7 @@ nfs4_laundromat(struct nfsd_net *nn)
        while (!list_empty(&nn->blocked_locks_lru)) {
                nbl = list_first_entry(&nn->blocked_locks_lru,
                                        struct nfsd4_blocked_lock, nbl_lru);
-               if (time_after((unsigned long)nbl->nbl_time,
-                              (unsigned long)cutoff)) {
+               if (nbl->nbl_time > cutoff) {
                        t = nbl->nbl_time - cutoff;
                        new_timeo = min(new_timeo, t);
                        break;
@@ -5383,7 +5379,7 @@ nfs4_laundromat(struct nfsd_net *nn)
                free_blocked_lock(nbl);
        }
 out:
-       new_timeo = max_t(time_t, new_timeo, NFSD_LAUNDROMAT_MINTIMEOUT);
+       new_timeo = max_t(time64_t, new_timeo, NFSD_LAUNDROMAT_MINTIMEOUT);
        return new_timeo;
 }
 
@@ -5393,13 +5389,13 @@ static void laundromat_main(struct work_struct *);
 static void
 laundromat_main(struct work_struct *laundry)
 {
-       time_t t;
+       time64_t t;
        struct delayed_work *dwork = to_delayed_work(laundry);
        struct nfsd_net *nn = container_of(dwork, struct nfsd_net,
                                           laundromat_work);
 
        t = nfs4_laundromat(nn);
-       dprintk("NFSD: laundromat_main - sleeping for %ld seconds\n", t);
+       dprintk("NFSD: laundromat_main - sleeping for %lld seconds\n", t);
        queue_delayed_work(laundry_wq, &nn->laundromat_work, t*HZ);
 }
 
@@ -5723,7 +5719,7 @@ static __be32 find_cpntf_state(struct nfsd_net *nn, stateid_t *st,
        if (status)
                return status;
 
-       cps->cpntf_time = get_seconds();
+       cps->cpntf_time = ktime_get_boottime_seconds();
        memset(&cstate, 0, sizeof(cstate));
        status = lookup_clientid(&cps->cp_p_clid, &cstate, nn, true);
        if (status)
@@ -6700,7 +6696,7 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
        }
 
        if (fl_flags & FL_SLEEP) {
-               nbl->nbl_time = get_seconds();
+               nbl->nbl_time = ktime_get_boottime_seconds();
                spin_lock(&nn->blocked_locks_lock);
                list_add_tail(&nbl->nbl_list, &lock_sop->lo_blocked);
                list_add_tail(&nbl->nbl_lru, &nn->blocked_locks_lru);
@@ -7861,7 +7857,7 @@ nfs4_state_start_net(struct net *net)
        nfsd4_client_tracking_init(net);
        if (nn->track_reclaim_completes && nn->reclaim_str_hashtbl_size == 0)
                goto skip_grace;
-       printk(KERN_INFO "NFSD: starting %ld-second grace period (net %x)\n",
+       printk(KERN_INFO "NFSD: starting %lld-second grace period (net %x)\n",
               nn->nfsd4_grace, net->ns.inum);
        queue_delayed_work(laundry_wq, &nn->laundromat_work, nn->nfsd4_grace * HZ);
        return 0;

diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index 11b42c523f045b15875a98c988a737c6107797fc..aace740d5a9242e75631b7a5c8f29e3f54171d9e 100644 (file)
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -956,7 +956,7 @@ static ssize_t write_maxconn(struct file *file, char *buf, size_t size)
 
 #ifdef CONFIG_NFSD_V4
 static ssize_t __nfsd4_write_time(struct file *file, char *buf, size_t size,
-                                 time_t *time, struct nfsd_net *nn)
+                                 time64_t *time, struct nfsd_net *nn)
 {
        char *mesg = buf;
        int rv, i;
@@ -984,11 +984,11 @@ static ssize_t __nfsd4_write_time(struct file *file, char *buf, size_t size,
                *time = i;
        }
 
-       return scnprintf(buf, SIMPLE_TRANSACTION_LIMIT, "%ld\n", *time);
+       return scnprintf(buf, SIMPLE_TRANSACTION_LIMIT, "%lld\n", *time);
 }
 
 static ssize_t nfsd4_write_time(struct file *file, char *buf, size_t size,
-                               time_t *time, struct nfsd_net *nn)
+                               time64_t *time, struct nfsd_net *nn)
 {
        ssize_t rv;
 

diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
index df6bd2cb257f81d96e28cdadc4a77b6094e27a3a..68d3f30ee760c2c6d0b8341fda1b453d4bada813 100644 (file)
--- a/fs/nfsd/state.h
+++ b/fs/nfsd/state.h
@@ -121,7 +121,7 @@ struct nfs4_cpntf_state {
        struct list_head        cp_list;        /* per parent nfs4_stid */
        stateid_t               cp_p_stateid;   /* copy of parent's stateid */
        clientid_t              cp_p_clid;      /* copy of parent's clid */
-       time_t                  cpntf_time;     /* last time stateid used */
+       time64_t                cpntf_time;     /* last time stateid used */
 };
 
 /*
@@ -152,7 +152,7 @@ struct nfs4_delegation {
        struct list_head        dl_recall_lru;  /* delegation recalled */
        struct nfs4_clnt_odstate *dl_clnt_odstate;
        u32                     dl_type;
-       time_t                  dl_time;
+       time64_t                dl_time;
 /* For recall: */
        int                     dl_retries;
        struct nfsd4_callback   dl_recall;
@@ -330,7 +330,7 @@ struct nfs4_client {
 #endif
        struct xdr_netobj       cl_name;        /* id generated by client */
        nfs4_verifier           cl_verifier;    /* generated by client */
-       time_t                  cl_time;        /* time of last lease renewal */
+       time64_t                cl_time;        /* time of last lease renewal */
        struct sockaddr_storage cl_addr;        /* client ipaddress */
        bool                    cl_mach_cred;   /* SP4_MACH_CRED in force */
        struct svc_cred         cl_cred;        /* setclientid principal */
@@ -469,7 +469,7 @@ struct nfs4_openowner {
         */
        struct list_head        oo_close_lru;
        struct nfs4_ol_stateid *oo_last_closed_stid;
-       time_t                  oo_time; /* time of placement on so_close_lru */
+       time64_t                oo_time; /* time of placement on so_close_lru */
 #define NFS4_OO_CONFIRMED   1
        unsigned char           oo_flags;
 };
@@ -626,7 +626,7 @@ static inline bool nfsd4_stateid_generation_after(stateid_t *a, stateid_t *b)
 struct nfsd4_blocked_lock {
        struct list_head        nbl_list;
        struct list_head        nbl_lru;
-       time_t                  nbl_time;
+       time64_t                nbl_time;
        struct file_lock        nbl_lock;
        struct knfsd_fh         nbl_fh;
        struct nfsd4_callback   nbl_cb;