[PATCH 02/11] xfs: refactor quota expiration timer modification

Darrick J. Wong
2020-08-17T22:59:08Z

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

Define explicit limits on the range of quota grace period expiration
timeouts and refactor the code that modifies the timeouts into helpers
that clamp the values appropriately.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
fs/xfs/libxfs/xfs_format.h | 22 ++++++++++++++++++++++
fs/xfs/xfs_dquot.c | 13 ++++++++++++-
fs/xfs/xfs_dquot.h | 2 ++
fs/xfs/xfs_ondisk.h | 2 ++
fs/xfs/xfs_qm_syscalls.c | 9 +++++++--
5 files changed, 45 insertions(+), 3 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_format.h b/fs/xfs/libxfs/xfs_format.h
index b1b8a5c05cea..ef36978239ac 100644
--- a/fs/xfs/libxfs/xfs_format.h
+++ b/fs/xfs/libxfs/xfs_format.h
@@ -1197,6 +1197,28 @@ static inline void xfs_dinode_put_rdev(struct xfs_dinode *dip, xfs_dev_t rdev)

#define XFS_DQTYPE_ANY (XFS_DQTYPE_REC_MASK)

+/*
+ * XFS Quota Timers
+ * ================
+ *
+ * Quota grace period expiration timers are an unsigned 32-bit seconds counter;
+ * time zero is the Unix epoch, Jan 1 00:00:01 UTC 1970. An expiration value
+ * of zero means that the quota limit has not been reached, and therefore no
+ * expiration has been set.
+ */
+
+/*
+ * Smallest possible quota expiration with traditional timestamps, which is
+ * Jan 1 00:00:01 UTC 1970.
+ */
+#define XFS_DQ_TIMEOUT_MIN ((int64_t)1)
+
+/*
+ * Largest possible quota expiration with traditional timestamps, which is
+ * Feb 7 06:28:15 UTC 2106.
+ */
+#define XFS_DQ_TIMEOUT_MAX ((int64_t)U32_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/fs/xfs/xfs_dquot.c b/fs/xfs/xfs_dquot.c
index bcd73b9c2994..2425b1c30d11 100644
--- a/fs/xfs/xfs_dquot.c
+++ b/fs/xfs/xfs_dquot.c
@@ -98,6 +98,16 @@ xfs_qm_adjust_dqlimits(
xfs_dquot_set_prealloc_limits(dq);
}

+/* Set the expiration time of a quota's grace period. */
+void
+xfs_dquot_set_timeout(
+ time64_t *timer,
+ time64_t value)
+{
+ *timer = clamp_t(time64_t, value, XFS_DQ_TIMEOUT_MIN,
+ XFS_DQ_TIMEOUT_MAX);
+}
+
/*
* Determine if this quota counter is over either limit and set the quota
* timers as appropriate.
@@ -112,7 +122,8 @@ xfs_qm_adjust_res_timer(
if ((res->softlimit && res->count > res->softlimit) ||
(res->hardlimit && res->count > res->hardlimit)) {
if (res->timer == 0)
- res->timer = ktime_get_real_seconds() + qlim->time;
+ xfs_dquot_set_timeout(&res->timer,
+ ktime_get_real_seconds() + qlim->time);
} else {
if (res->timer == 0)
res->warnings = 0;
diff --git a/fs/xfs/xfs_dquot.h b/fs/xfs/xfs_dquot.h
index 282a65da93c7..11bd0ee9b0fa 100644
--- a/fs/xfs/xfs_dquot.h
+++ b/fs/xfs/xfs_dquot.h
@@ -237,4 +237,6 @@ typedef int (*xfs_qm_dqiterate_fn)(struct xfs_dquot *dq,
int xfs_qm_dqiterate(struct xfs_mount *mp, xfs_dqtype_t type,
xfs_qm_dqiterate_fn iter_fn, void *priv);

+void xfs_dquot_set_timeout(time64_t *timer, time64_t limit);
+
#endif /* __XFS_DQUOT_H__ */
diff --git a/fs/xfs/xfs_ondisk.h b/fs/xfs/xfs_ondisk.h
index 48a64fa49f91..38ccffcf3336 100644
--- a/fs/xfs/xfs_ondisk.h
+++ b/fs/xfs/xfs_ondisk.h
@@ -25,6 +25,8 @@ xfs_check_limits(void)
/* make sure timestamp limits are correct */
XFS_CHECK_VALUE(XFS_INO_TIME_MIN, -2147483648LL);
XFS_CHECK_VALUE(XFS_INO_TIME_MAX, 2147483647LL);
+ XFS_CHECK_VALUE(XFS_DQ_TIMEOUT_MIN, 1LL);
+ XFS_CHECK_VALUE(XFS_DQ_TIMEOUT_MAX, 4294967295LL);
}

static inline void __init
diff --git a/fs/xfs/xfs_qm_syscalls.c b/fs/xfs/xfs_qm_syscalls.c
index 1c542b4a5220..b16d533a6feb 100644
--- a/fs/xfs/xfs_qm_syscalls.c
+++ b/fs/xfs/xfs_qm_syscalls.c
@@ -483,9 +483,14 @@ xfs_setqlim_timer(
struct xfs_quota_limits *qlim,
s64 timer)
{
- res->timer = timer;
- if (qlim)
+ if (qlim) {
+ /* Set the length of the default grace period. */
+ res->timer = timer;
qlim->time = timer;
+ } else {
+ /* Set the grace period expiration on a quota. */
+ xfs_dquot_set_timeout(&res->timer, timer);
+ }
}

/*