xfs: quota: move to time64_t interfaces

As a preparation for removing the 32-bit time_t type and
all associated interfaces, change xfs to use time64_t and
ktime_get_real_seconds() for the quota housekeeping.

This avoids one difference between 32-bit and 64-bit kernels,
raising the theoretical limit for the quota grace period
to year 2106 on 32-bit instead of year 2038.

Note that common user space tools using the XFS quotactl
interface instead of the generic one still use the y2038
dates.

To fix quotas properly, both the on-disk format and user
space still need to be changed.

Signed-off-by: Arnd Bergmann <[e-mail]>
Reviewed-by: Christoph Hellwig <[e-mail]>
Reviewed-by: Darrick J. Wong <[e-mail]>
Signed-off-by: Darrick J. Wong <[e-mail]>

fs/xfs/xfs_dquot.c

···
 		    (d->d_blk_hardlimit &&
 		     (be64_to_cpu(d->d_bcount) >
 		      be64_to_cpu(d->d_blk_hardlimit)))) {
-			d->d_btimer = cpu_to_be32(get_seconds() +
+			d->d_btimer = cpu_to_be32(ktime_get_real_seconds() +
 					mp->m_quotainfo->qi_btimelimit);
 		} else {
 			d->d_bwarns = 0;
···
 		    (d->d_ino_hardlimit &&
 		     (be64_to_cpu(d->d_icount) >
 		      be64_to_cpu(d->d_ino_hardlimit)))) {
-			d->d_itimer = cpu_to_be32(get_seconds() +
+			d->d_itimer = cpu_to_be32(ktime_get_real_seconds() +
 					mp->m_quotainfo->qi_itimelimit);
 		} else {
 			d->d_iwarns = 0;
···
 		    (d->d_rtb_hardlimit &&
 		     (be64_to_cpu(d->d_rtbcount) >
 		      be64_to_cpu(d->d_rtb_hardlimit)))) {
-			d->d_rtbtimer = cpu_to_be32(get_seconds() +
+			d->d_rtbtimer = cpu_to_be32(ktime_get_real_seconds() +
 					mp->m_quotainfo->qi_rtbtimelimit);
 		} else {
 			d->d_rtbwarns = 0;

fs/xfs/xfs_qm.h

···
 	struct xfs_inode	*qi_pquotaip;	/* project quota inode */
 	struct list_lru	 qi_lru;
 	int		 qi_dquots;
-	time_t		 qi_btimelimit;	 /* limit for blks timer */
-	time_t		 qi_itimelimit;	 /* limit for inodes timer */
-	time_t		 qi_rtbtimelimit;/* limit for rt blks timer */
+	time64_t	 qi_btimelimit;	 /* limit for blks timer */
+	time64_t	 qi_itimelimit;	 /* limit for inodes timer */
+	time64_t	 qi_rtbtimelimit;/* limit for rt blks timer */
 	xfs_qwarncnt_t	 qi_bwarnlimit;	 /* limit for blks warnings */
 	xfs_qwarncnt_t	 qi_iwarnlimit;	 /* limit for inodes warnings */
 	xfs_qwarncnt_t	 qi_rtbwarnlimit;/* limit for rt blks warnings */

fs/xfs/xfs_quotaops.c

···
 	tstate->flags |= QCI_SYSFILE;
 	tstate->blocks = ip->i_d.di_nblocks;
 	tstate->nextents = ip->i_d.di_nextents;
-	tstate->spc_timelimit = q->qi_btimelimit;
-	tstate->ino_timelimit = q->qi_itimelimit;
-	tstate->rt_spc_timelimit = q->qi_rtbtimelimit;
+	tstate->spc_timelimit = (u32)q->qi_btimelimit;
+	tstate->ino_timelimit = (u32)q->qi_itimelimit;
+	tstate->rt_spc_timelimit = (u32)q->qi_rtbtimelimit;
 	tstate->spc_warnlimit = q->qi_bwarnlimit;
 	tstate->ino_warnlimit = q->qi_iwarnlimit;
 	tstate->rt_spc_warnlimit = q->qi_rtbwarnlimit;

fs/xfs/xfs_trans_dquot.c

···
 {
 	xfs_qcnt_t		hardlimit;
 	xfs_qcnt_t		softlimit;
-	time_t			timer;
+	time64_t		timer;
 	xfs_qwarncnt_t		warns;
 	xfs_qwarncnt_t		warnlimit;
 	xfs_qcnt_t		total_count;
···
 				goto error_return;
 			}
 			if (softlimit && total_count > softlimit) {
-				if ((timer != 0 && get_seconds() > timer) ||
+				if ((timer != 0 &&
+				     ktime_get_real_seconds() > timer) ||
 				    (warns != 0 && warns >= warnlimit)) {
 					xfs_quota_warn(mp, dqp,
 						       QUOTA_NL_BSOFTLONGWARN);
···
 				goto error_return;
 			}
 			if (softlimit && total_count > softlimit) {
-				if  ((timer != 0 && get_seconds() > timer) ||
+				if  ((timer != 0 &&
+				      ktime_get_real_seconds() > timer) ||
 				     (warns != 0 && warns >= warnlimit)) {
 					xfs_quota_warn(mp, dqp,
 						       QUOTA_NL_ISOFTLONGWARN);