quota: widen timestamps for the fs_disk_quota structure

Soon, XFS will support quota grace period expiration timestamps beyond
the year 2038, widen the timestamp fields to handle the extra time bits.
Internally, XFS now stores unsigned 34-bit quantities, so the extra 8
bits here should work fine.  (Note that XFS is the only user of this
structure.)

Link: https://lore.kernel.org/r/20200909163413.GJ7955@magnolia
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>

1 files changed, 36 insertions, 6 deletions

diff --git a/fs/quota/quota.c b/fs/quota/quota.c
index 47f9e151988b..52362eeaea94 100644
--- a/fs/quota/quota.c
+++ b/fs/quota/quota.c
@@ -481,6 +481,14 @@ static inline u64 quota_btobb(u64 bytes)
 	return (bytes + (1 << XFS_BB_SHIFT) - 1) >> XFS_BB_SHIFT;
 }
 
+static inline s64 copy_from_xfs_dqblk_ts(const struct fs_disk_quota *d,
+		__s32 timer, __s8 timer_hi)
+{
+	if (d->d_fieldmask & FS_DQ_BIGTIME)
+		return (u32)timer | (s64)timer_hi << 32;
+	return timer;
+}
+
 static void copy_from_xfs_dqblk(struct qc_dqblk *dst, struct fs_disk_quota *src)
 {
 	dst->d_spc_hardlimit = quota_bbtob(src->d_blk_hardlimit);
@@ -489,14 +497,17 @@ static void copy_from_xfs_dqblk(struct qc_dqblk *dst, struct fs_disk_quota *src)
 	dst->d_ino_softlimit = src->d_ino_softlimit;
 	dst->d_space = quota_bbtob(src->d_bcount);
 	dst->d_ino_count = src->d_icount;
-	dst->d_ino_timer = src->d_itimer;
-	dst->d_spc_timer = src->d_btimer;
+	dst->d_ino_timer = copy_from_xfs_dqblk_ts(src, src->d_itimer,
+						  src->d_itimer_hi);
+	dst->d_spc_timer = copy_from_xfs_dqblk_ts(src, src->d_btimer,
+						  src->d_btimer_hi);
 	dst->d_ino_warns = src->d_iwarns;
 	dst->d_spc_warns = src->d_bwarns;
 	dst->d_rt_spc_hardlimit = quota_bbtob(src->d_rtb_hardlimit);
 	dst->d_rt_spc_softlimit = quota_bbtob(src->d_rtb_softlimit);
 	dst->d_rt_space = quota_bbtob(src->d_rtbcount);
-	dst->d_rt_spc_timer = src->d_rtbtimer;
+	dst->d_rt_spc_timer = copy_from_xfs_dqblk_ts(src, src->d_rtbtimer,
+						     src->d_rtbtimer_hi);
 	dst->d_rt_spc_warns = src->d_rtbwarns;
 	dst->d_fieldmask = 0;
 	if (src->d_fieldmask & FS_DQ_ISOFT)
@@ -588,10 +599,26 @@ static int quota_setxquota(struct super_block *sb, int type, qid_t id,
 	return sb->s_qcop->set_dqblk(sb, qid, &qdq);
 }
 
+static inline void copy_to_xfs_dqblk_ts(const struct fs_disk_quota *d,
+		__s32 *timer_lo, __s8 *timer_hi, s64 timer)
+{
+	*timer_lo = timer;
+	if (d->d_fieldmask & FS_DQ_BIGTIME)
+		*timer_hi = timer >> 32;
+}
+
+static inline bool want_bigtime(s64 timer)
+{
+	return timer > S32_MAX || timer < S32_MIN;
+}
+
 static void copy_to_xfs_dqblk(struct fs_disk_quota *dst, struct qc_dqblk *src,
 			      int type, qid_t id)
 {
 	memset(dst, 0, sizeof(*dst));
+	if (want_bigtime(src->d_ino_timer) || want_bigtime(src->d_spc_timer) ||
+	    want_bigtime(src->d_rt_spc_timer))
+		dst->d_fieldmask |= FS_DQ_BIGTIME;
 	dst->d_version = FS_DQUOT_VERSION;
 	dst->d_id = id;
 	if (type == USRQUOTA)
@@ -606,14 +633,17 @@ static void copy_to_xfs_dqblk(struct fs_disk_quota *dst, struct qc_dqblk *src,
 	dst->d_ino_softlimit = src->d_ino_softlimit;
 	dst->d_bcount = quota_btobb(src->d_space);
 	dst->d_icount = src->d_ino_count;
-	dst->d_itimer = src->d_ino_timer;
-	dst->d_btimer = src->d_spc_timer;
+	copy_to_xfs_dqblk_ts(dst, &dst->d_itimer, &dst->d_itimer_hi,
+			     src->d_ino_timer);
+	copy_to_xfs_dqblk_ts(dst, &dst->d_btimer, &dst->d_btimer_hi,
+			     src->d_spc_timer);
 	dst->d_iwarns = src->d_ino_warns;
 	dst->d_bwarns = src->d_spc_warns;
 	dst->d_rtb_hardlimit = quota_btobb(src->d_rt_spc_hardlimit);
 	dst->d_rtb_softlimit = quota_btobb(src->d_rt_spc_softlimit);
 	dst->d_rtbcount = quota_btobb(src->d_rt_space);
-	dst->d_rtbtimer = src->d_rt_spc_timer;
+	copy_to_xfs_dqblk_ts(dst, &dst->d_rtbtimer, &dst->d_rtbtimer_hi,
+			     src->d_rt_spc_timer);
 	dst->d_rtbwarns = src->d_rt_spc_warns;
 }