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>

1 files changed, 5 insertions, 5 deletions

diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
index df6bd2cb257f..68d3f30ee760 100644
--- 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;