[PATCH 12/18] xfs: enable bigtime for quota timers

From: "Darrick J. Wong" <darrick.wong@oracle.com>
To: sandeen@sandeen.net, darrick.wong@oracle.com
Cc: linux-xfs@vger.kernel.org
Subject: [PATCH 12/18] xfs: enable bigtime for quota timers
Date: Mon, 17 Aug 2020 16:00:09 -0700	[thread overview]
Message-ID: <159770520929.3958786.2869468837745844258.stgit@magnolia> (raw)
In-Reply-To: <159770513155.3958786.16108819726679724438.stgit@magnolia>

From: Darrick J. Wong <darrick.wong@oracle.com>

Enable the bigtime feature for quota timers.  We decrease the accuracy
of the timers to ~4s in exchange for being able to set timers up to the
bigtime maximum.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
 include/xfs_mount.h     |    5 +++++
 libxfs/xfs_dquot_buf.c  |   40 ++++++++++++++++++++++++++++++++++++++++
 libxfs/xfs_format.h     |   26 +++++++++++++++++++++++++-
 libxfs/xfs_quota_defs.h |    3 ++-
 4 files changed, 72 insertions(+), 2 deletions(-)

diff --git a/include/xfs_mount.h b/include/xfs_mount.h
index 20c8bfaf4fa8..be74a922b7a1 100644
--- a/include/xfs_mount.h
+++ b/include/xfs_mount.h
@@ -184,4 +184,9 @@ extern xfs_mount_t	*libxfs_mount (xfs_mount_t *, xfs_sb_t *,
 int		libxfs_umount(struct xfs_mount *mp);
 extern void	libxfs_rtmount_destroy (xfs_mount_t *);
 
+/* Dummy xfs_dquot so that libxfs compiles. */
+struct xfs_dquot {
+	int		q_type;
+};
+
 #endif	/* __XFS_MOUNT_H__ */
diff --git a/libxfs/xfs_dquot_buf.c b/libxfs/xfs_dquot_buf.c
index 847b9ba5280c..e5938ef649f0 100644
--- a/libxfs/xfs_dquot_buf.c
+++ b/libxfs/xfs_dquot_buf.c
@@ -67,6 +67,13 @@ xfs_dquot_verify(
 	    ddq_type != XFS_DQTYPE_GROUP)
 		return __this_address;
 
+	if ((ddq->d_type & XFS_DQTYPE_BIGTIME) &&
+	    !xfs_sb_version_hasbigtime(&mp->m_sb))
+		return __this_address;
+
+	if ((ddq->d_type & XFS_DQTYPE_BIGTIME) && !ddq->d_id)
+		return __this_address;
+
 	if (id != -1 && id != be32_to_cpu(ddq->d_id))
 		return __this_address;
 
@@ -294,6 +301,20 @@ xfs_dquot_from_disk_timestamp(
 	time64_t		*timer,
 	__be32			dtimer)
 {
+	/* Zero always means zero, regardless of encoding. */
+	if (!dtimer) {
+		*timer = 0;
+		return;
+	}
+
+	if (ddq->d_type & XFS_DQTYPE_BIGTIME) {
+		uint64_t	t;
+
+		t = be32_to_cpu(dtimer);
+		*timer = t << XFS_DQ_BIGTIME_SHIFT;
+		return;
+	}
+
 	*timer = be32_to_cpu(dtimer);
 }
 
@@ -304,5 +325,24 @@ xfs_dquot_to_disk_timestamp(
 	__be32			*dtimer,
 	time64_t		timer)
 {
+	/* Zero always means zero, regardless of encoding. */
+	if (!timer) {
+		*dtimer = cpu_to_be32(0);
+		return;
+	}
+
+	if (dqp->q_type & XFS_DQTYPE_BIGTIME) {
+		uint64_t	t = timer;
+
+		/*
+		 * Round the end of the grace period up to the nearest bigtime
+		 * interval that we support, to give users the most time to fix
+		 * the problems.
+		 */
+		t = roundup_64(t, 1U << XFS_DQ_BIGTIME_SHIFT);
+		*dtimer = cpu_to_be32(t >> XFS_DQ_BIGTIME_SHIFT);
+		return;
+	}
+
 	*dtimer = cpu_to_be32(timer);
 }
diff --git a/libxfs/xfs_format.h b/libxfs/xfs_format.h
index 67303e517260..87c86a6dfb91 100644
--- a/libxfs/xfs_format.h
+++ b/libxfs/xfs_format.h
@@ -1228,13 +1228,15 @@ static inline void xfs_dinode_put_rdev(struct xfs_dinode *dip, xfs_dev_t rdev)
 #define XFS_DQTYPE_USER		0x01		/* user dquot record */
 #define XFS_DQTYPE_PROJ		0x02		/* project dquot record */
 #define XFS_DQTYPE_GROUP	0x04		/* group dquot record */
+#define XFS_DQTYPE_BIGTIME	0x08		/* large expiry timestamps */
 
 /* bitmask to determine if this is a user/group/project dquot */
 #define XFS_DQTYPE_REC_MASK	(XFS_DQTYPE_USER | \
 				 XFS_DQTYPE_PROJ | \
 				 XFS_DQTYPE_GROUP)
 
-#define XFS_DQTYPE_ANY		(XFS_DQTYPE_REC_MASK)
+#define XFS_DQTYPE_ANY		(XFS_DQTYPE_REC_MASK | \
+				 XFS_DQTYPE_BIGTIME)
 
 /*
  * XFS Quota Timers
@@ -1271,6 +1273,28 @@ static inline void xfs_dinode_put_rdev(struct xfs_dinode *dip, xfs_dev_t rdev)
 #define XFS_DQ_GRACE_MIN	((int64_t)0)
 #define XFS_DQ_GRACE_MAX	((int64_t)U32_MAX)
 
+/*
+ * When bigtime is enabled, we trade a few bits of precision to expand the
+ * expiration timeout range to match that of big inode timestamps.  The grace
+ * periods stored in dquot 0 are not shifted, since they record an interval,
+ * not a timestamp.
+ */
+#define XFS_DQ_BIGTIME_SHIFT		(2)
+
+/*
+ * Smallest possible quota expiration with big timestamps, which is
+ * Jan  1 00:00:01 UTC 1970.
+ */
+#define XFS_DQ_BIGTIMEOUT_MIN		(XFS_DQ_TIMEOUT_MIN)
+
+/*
+ * Largest supported quota expiration with traditional timestamps, which is
+ * the largest bigtime inode timestamp, or Jul  2 20:20:25 UTC 2486.  The field
+ * is large enough that it's possible to fit expirations up to 2514, but we
+ * want to keep the maximum timestamp in sync.
+ */
+#define XFS_DQ_BIGTIMEOUT_MAX		(XFS_INO_BIGTIME_MAX)
+
 /*
  * This is the main portion of the on-disk representation of quota information
  * for a user.  We pad this with some more expansion room to construct the on
diff --git a/libxfs/xfs_quota_defs.h b/libxfs/xfs_quota_defs.h
index b524059faab5..b9a47eae684b 100644
--- a/libxfs/xfs_quota_defs.h
+++ b/libxfs/xfs_quota_defs.h
@@ -23,7 +23,8 @@ typedef uint8_t		xfs_dqtype_t;
 #define XFS_DQTYPE_STRINGS \
 	{ XFS_DQTYPE_USER,	"USER" }, \
 	{ XFS_DQTYPE_PROJ,	"PROJ" }, \
-	{ XFS_DQTYPE_GROUP,	"GROUP" }
+	{ XFS_DQTYPE_GROUP,	"GROUP" }, \
+	{ XFS_DQTYPE_BIGTIME,	"BIGTIME" }
 
 /*
  * flags for q_flags field in the dquot.

