xfs: create quota preallocation watermarks for realtime quota

Refactor the quota preallocation watermarking code so that it'll work
for realtime quota too.  Convert the do_div calls into div_u64 for
compactness.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

Author: Darrick J. Wong

fs/xfs/xfs_dquot.c

@@ -277,6 +277,25 @@ xfs_qm_init_dquot_blk(
 		xfs_trans_log_buf(tp, bp, 0, BBTOB(q->qi_dqchunklen) - 1);
 }
 
+static void
+xfs_dquot_set_prealloc(
+	struct xfs_dquot_pre		*pre,
+	const struct xfs_dquot_res	*res)
+{
+	xfs_qcnt_t			space;
+
+	pre->q_prealloc_hi_wmark = res->hardlimit;
+	pre->q_prealloc_lo_wmark = res->softlimit;
+
+	space = div_u64(pre->q_prealloc_hi_wmark, 100);
+	if (!pre->q_prealloc_lo_wmark)
+		pre->q_prealloc_lo_wmark = space * 95;
+
+	pre->q_low_space[XFS_QLOWSP_1_PCNT] = space;
+	pre->q_low_space[XFS_QLOWSP_3_PCNT] = space * 3;
+	pre->q_low_space[XFS_QLOWSP_5_PCNT] = space * 5;
+}
+
 /*
  * Initialize the dynamic speculative preallocation thresholds. The lo/hi
  * watermarks correspond to the soft and hard limits by default. If a soft limit
@@ -285,22 +304,8 @@ xfs_qm_init_dquot_blk(
 void
 xfs_dquot_set_prealloc_limits(struct xfs_dquot *dqp)
 {
-	uint64_t space;
-
-	dqp->q_prealloc_hi_wmark = dqp->q_blk.hardlimit;
-	dqp->q_prealloc_lo_wmark = dqp->q_blk.softlimit;
-	if (!dqp->q_prealloc_lo_wmark) {
-		dqp->q_prealloc_lo_wmark = dqp->q_prealloc_hi_wmark;
-		do_div(dqp->q_prealloc_lo_wmark, 100);
-		dqp->q_prealloc_lo_wmark *= 95;
-	}
-
-	space = dqp->q_prealloc_hi_wmark;
-
-	do_div(space, 100);
-	dqp->q_low_space[XFS_QLOWSP_1_PCNT] = space;
-	dqp->q_low_space[XFS_QLOWSP_3_PCNT] = space * 3;
-	dqp->q_low_space[XFS_QLOWSP_5_PCNT] = space * 5;
+	xfs_dquot_set_prealloc(&dqp->q_blk_prealloc, &dqp->q_blk);
+	xfs_dquot_set_prealloc(&dqp->q_rtb_prealloc, &dqp->q_rtb);
 }
 
 /*

fs/xfs/xfs_dquot.h

@@ -56,6 +56,12 @@ xfs_dquot_res_over_limits(
 	return false;
 }
 
+struct xfs_dquot_pre {
+	xfs_qcnt_t		q_prealloc_lo_wmark;
+	xfs_qcnt_t		q_prealloc_hi_wmark;
+	int64_t			q_low_space[XFS_QLOWSP_MAX];
+};
+
 /*
  * The incore dquot structure
  */
@@ -76,9 +82,9 @@ struct xfs_dquot {
 
 	struct xfs_dq_logitem	q_logitem;
 
-	xfs_qcnt_t		q_prealloc_lo_wmark;
-	xfs_qcnt_t		q_prealloc_hi_wmark;
-	int64_t			q_low_space[XFS_QLOWSP_MAX];
+	struct xfs_dquot_pre	q_blk_prealloc;
+	struct xfs_dquot_pre	q_rtb_prealloc;
+
 	struct mutex		q_qlock;
 	struct completion	q_flush;
 	atomic_t		q_pincount;
@@ -192,7 +198,11 @@ static inline bool xfs_dquot_lowsp(struct xfs_dquot *dqp)
 	int64_t freesp;
 
 	freesp = dqp->q_blk.hardlimit - dqp->q_blk.reserved;
-	if (freesp < dqp->q_low_space[XFS_QLOWSP_1_PCNT])
+	if (freesp < dqp->q_blk_prealloc.q_low_space[XFS_QLOWSP_1_PCNT])
+		return true;
+
+	freesp = dqp->q_rtb.hardlimit - dqp->q_rtb.reserved;
+	if (freesp < dqp->q_rtb_prealloc.q_low_space[XFS_QLOWSP_1_PCNT])
 		return true;
 
 	return false;

fs/xfs/xfs_iomap.c

@@ -353,16 +353,26 @@ xfs_quota_need_throttle(
 	xfs_fsblock_t		alloc_blocks)
 {
 	struct xfs_dquot	*dq = xfs_inode_dquot(ip, type);
+	struct xfs_dquot_res	*res;
+	struct xfs_dquot_pre	*pre;
 
 	if (!dq || !xfs_this_quota_on(ip->i_mount, type))
 		return false;
 
+	if (XFS_IS_REALTIME_INODE(ip)) {
+		res = &dq->q_rtb;
+		pre = &dq->q_rtb_prealloc;
+	} else {
+		res = &dq->q_blk;
+		pre = &dq->q_blk_prealloc;
+	}
+
 	/* no hi watermark, no throttle */
-	if (!dq->q_prealloc_hi_wmark)
+	if (!pre->q_prealloc_hi_wmark)
 		return false;
 
 	/* under the lo watermark, no throttle */
-	if (dq->q_blk.reserved + alloc_blocks < dq->q_prealloc_lo_wmark)
+	if (res->reserved + alloc_blocks < pre->q_prealloc_lo_wmark)
 		return false;
 
 	return true;
@@ -377,22 +387,35 @@ xfs_quota_calc_throttle(
 	int64_t			*qfreesp)
 {
 	struct xfs_dquot	*dq = xfs_inode_dquot(ip, type);
+	struct xfs_dquot_res	*res;
+	struct xfs_dquot_pre	*pre;
 	int64_t			freesp;
 	int			shift = 0;
 
+	if (!dq) {
+		res = NULL;
+		pre = NULL;
+	} else if (XFS_IS_REALTIME_INODE(ip)) {
+		res = &dq->q_rtb;
+		pre = &dq->q_rtb_prealloc;
+	} else {
+		res = &dq->q_blk;
+		pre = &dq->q_blk_prealloc;
+	}
+
 	/* no dq, or over hi wmark, squash the prealloc completely */
-	if (!dq || dq->q_blk.reserved >= dq->q_prealloc_hi_wmark) {
+	if (!res || res->reserved >= pre->q_prealloc_hi_wmark) {
 		*qblocks = 0;
 		*qfreesp = 0;
 		return;
 	}
 
-	freesp = dq->q_prealloc_hi_wmark - dq->q_blk.reserved;
-	if (freesp < dq->q_low_space[XFS_QLOWSP_5_PCNT]) {
+	freesp = pre->q_prealloc_hi_wmark - res->reserved;
+	if (freesp < pre->q_low_space[XFS_QLOWSP_5_PCNT]) {
 		shift = 2;
-		if (freesp < dq->q_low_space[XFS_QLOWSP_3_PCNT])
+		if (freesp < pre->q_low_space[XFS_QLOWSP_3_PCNT])
 			shift += 2;
-		if (freesp < dq->q_low_space[XFS_QLOWSP_1_PCNT])
+		if (freesp < pre->q_low_space[XFS_QLOWSP_1_PCNT])
 			shift += 2;
 	}
 

fs/xfs/xfs_qm.c

@@ -2178,6 +2178,8 @@ xfs_inode_near_dquot_enforcement(
 	xfs_dqtype_t		type)
 {
 	struct xfs_dquot	*dqp;
+	struct xfs_dquot_res	*res;
+	struct xfs_dquot_pre	*pre;
 	int64_t			freesp;
 
 	/* We only care for quotas that are enabled and enforced. */
@@ -2186,21 +2188,30 @@ xfs_inode_near_dquot_enforcement(
 		return false;
 
 	if (xfs_dquot_res_over_limits(&dqp->q_ino) ||
+	    xfs_dquot_res_over_limits(&dqp->q_blk) ||
 	    xfs_dquot_res_over_limits(&dqp->q_rtb))
 		return true;
 
+	if (XFS_IS_REALTIME_INODE(ip)) {
+		res = &dqp->q_rtb;
+		pre = &dqp->q_rtb_prealloc;
+	} else {
+		res = &dqp->q_blk;
+		pre = &dqp->q_blk_prealloc;
+	}
+
 	/* For space on the data device, check the various thresholds. */
-	if (!dqp->q_prealloc_hi_wmark)
+	if (!pre->q_prealloc_hi_wmark)
 		return false;
 
-	if (dqp->q_blk.reserved < dqp->q_prealloc_lo_wmark)
+	if (res->reserved < pre->q_prealloc_lo_wmark)
 		return false;
 
-	if (dqp->q_blk.reserved >= dqp->q_prealloc_hi_wmark)
+	if (res->reserved >= pre->q_prealloc_hi_wmark)
 		return true;
 
-	freesp = dqp->q_prealloc_hi_wmark - dqp->q_blk.reserved;
-	if (freesp < dqp->q_low_space[XFS_QLOWSP_5_PCNT])
+	freesp = pre->q_prealloc_hi_wmark - res->reserved;
+	if (freesp < pre->q_low_space[XFS_QLOWSP_5_PCNT])
 		return true;
 
 	return false;