xfs: create incore realtime group structures

Create an incore object that will contain information about a realtime
allocation group.  This will eventually enable us to shard the realtime
section in a similar manner to how we shard the data section, but for
now just a single object for the entire RT subvolume is created.

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

1 files changed, 151 insertions, 0 deletions

diff --git a/fs/xfs/libxfs/xfs_rtgroup.c b/fs/xfs/libxfs/xfs_rtgroup.c
new file mode 100644
index 000000000000..9d3842e83c93
--- /dev/null
+++ b/fs/xfs/libxfs/xfs_rtgroup.c
@@ -0,0 +1,151 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2022-2024 Oracle.  All Rights Reserved.
+ * Author: Darrick J. Wong <djwong@kernel.org>
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_bit.h"
+#include "xfs_sb.h"
+#include "xfs_mount.h"
+#include "xfs_btree.h"
+#include "xfs_alloc_btree.h"
+#include "xfs_rmap_btree.h"
+#include "xfs_alloc.h"
+#include "xfs_ialloc.h"
+#include "xfs_rmap.h"
+#include "xfs_ag.h"
+#include "xfs_ag_resv.h"
+#include "xfs_health.h"
+#include "xfs_error.h"
+#include "xfs_bmap.h"
+#include "xfs_defer.h"
+#include "xfs_log_format.h"
+#include "xfs_trans.h"
+#include "xfs_trace.h"
+#include "xfs_inode.h"
+#include "xfs_icache.h"
+#include "xfs_rtgroup.h"
+#include "xfs_rtbitmap.h"
+
+int
+xfs_rtgroup_alloc(
+	struct xfs_mount	*mp,
+	xfs_rgnumber_t		rgno,
+	xfs_rgnumber_t		rgcount,
+	xfs_rtbxlen_t		rextents)
+{
+	struct xfs_rtgroup	*rtg;
+	int			error;
+
+	rtg = kzalloc(sizeof(struct xfs_rtgroup), GFP_KERNEL);
+	if (!rtg)
+		return -ENOMEM;
+
+	error = xfs_group_insert(mp, rtg_group(rtg), rgno, XG_TYPE_RTG);
+	if (error)
+		goto out_free_rtg;
+	return 0;
+
+out_free_rtg:
+	kfree(rtg);
+	return error;
+}
+
+void
+xfs_rtgroup_free(
+	struct xfs_mount	*mp,
+	xfs_rgnumber_t		rgno)
+{
+	xfs_group_free(mp, rgno, XG_TYPE_RTG, NULL);
+}
+
+/* Free a range of incore rtgroup objects. */
+void
+xfs_free_rtgroups(
+	struct xfs_mount	*mp,
+	xfs_rgnumber_t		first_rgno,
+	xfs_rgnumber_t		end_rgno)
+{
+	xfs_rgnumber_t		rgno;
+
+	for (rgno = first_rgno; rgno < end_rgno; rgno++)
+		xfs_rtgroup_free(mp, rgno);
+}
+
+/* Initialize some range of incore rtgroup objects. */
+int
+xfs_initialize_rtgroups(
+	struct xfs_mount	*mp,
+	xfs_rgnumber_t		first_rgno,
+	xfs_rgnumber_t		end_rgno,
+	xfs_rtbxlen_t		rextents)
+{
+	xfs_rgnumber_t		index;
+	int			error;
+
+	if (first_rgno >= end_rgno)
+		return 0;
+
+	for (index = first_rgno; index < end_rgno; index++) {
+		error = xfs_rtgroup_alloc(mp, index, end_rgno, rextents);
+		if (error)
+			goto out_unwind_new_rtgs;
+	}
+
+	return 0;
+
+out_unwind_new_rtgs:
+	xfs_free_rtgroups(mp, first_rgno, index);
+	return error;
+}
+
+/* Compute the number of rt extents in this realtime group. */
+xfs_rtxnum_t
+__xfs_rtgroup_extents(
+	struct xfs_mount	*mp,
+	xfs_rgnumber_t		rgno,
+	xfs_rgnumber_t		rgcount,
+	xfs_rtbxlen_t		rextents)
+{
+	ASSERT(rgno < rgcount);
+	if (rgno == rgcount - 1)
+		return rextents - ((xfs_rtxnum_t)rgno * mp->m_sb.sb_rgextents);
+
+	ASSERT(xfs_has_rtgroups(mp));
+	return mp->m_sb.sb_rgextents;
+}
+
+xfs_rtxnum_t
+xfs_rtgroup_extents(
+	struct xfs_mount	*mp,
+	xfs_rgnumber_t		rgno)
+{
+	return __xfs_rtgroup_extents(mp, rgno, mp->m_sb.sb_rgcount,
+			mp->m_sb.sb_rextents);
+}
+
+/*
+ * Update the rt extent count of the previous tail rtgroup if it changed during
+ * recovery (i.e. recovery of a growfs).
+ */
+int
+xfs_update_last_rtgroup_size(
+	struct xfs_mount	*mp,
+	xfs_rgnumber_t		prev_rgcount)
+{
+	struct xfs_rtgroup	*rtg;
+
+	ASSERT(prev_rgcount > 0);
+
+	rtg = xfs_rtgroup_grab(mp, prev_rgcount - 1);
+	if (!rtg)
+		return -EFSCORRUPTED;
+	rtg->rtg_extents = __xfs_rtgroup_extents(mp, prev_rgcount - 1,
+			mp->m_sb.sb_rgcount, mp->m_sb.sb_rextents);
+	xfs_rtgroup_rele(rtg);
+	return 0;
+}