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+/*
+ * Copyright (C) 2016 Oracle. All Rights Reserved.
+ *
+ * Author: Darrick J. Wong <darrick.wong@oracle.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+#ifndef __XFS_RMAP_ITEM_H__
+#define __XFS_RMAP_ITEM_H__
+
+/*
+ * There are (currently) three pairs of rmap btree redo item types: map, unmap,
+ * and convert. The common abbreviations for these are RUI (rmap update
+ * intent) and RUD (rmap update done). The redo item type is encoded in the
+ * flags field of each xfs_map_extent.
+ *
+ * *I items should be recorded in the *first* of a series of rolled
+ * transactions, and the *D items should be recorded in the same transaction
+ * that records the associated rmapbt updates. Typically, the first
+ * transaction will record a bmbt update, followed by some number of
+ * transactions containing rmapbt updates, and finally transactions with any
+ * bnobt/cntbt updates.
+ *
+ * Should the system crash after the commit of the first transaction but
+ * before the commit of the final transaction in a series, log recovery will
+ * use the redo information recorded by the intent items to replay the
+ * (rmapbt/bnobt/cntbt) metadata updates in the non-first transaction.
+ */
+
+/* kernel only RUI/RUD definitions */
+
+struct xfs_mount;
+struct kmem_zone;
+
+/*
+ * Max number of extents in fast allocation path.
+ */
+#define XFS_RUI_MAX_FAST_EXTENTS 16
+
+/*
+ * Define RUI flag bits. Manipulated by set/clear/test_bit operators.
+ */
+#define XFS_RUI_RECOVERED 1
+
+/*
+ * This is the "rmap update intent" log item. It is used to log the fact that
+ * some reverse mappings need to change. It is used in conjunction with the
+ * "rmap update done" log item described below.
+ *
+ * These log items follow the same rules as struct xfs_efi_log_item; see the
+ * comments about that structure (in xfs_extfree_item.h) for more details.
+ */
+struct xfs_rui_log_item {
+ struct xfs_log_item rui_item;
+ atomic_t rui_refcount;
+ atomic_t rui_next_extent;
+ unsigned long rui_flags; /* misc flags */
+ struct xfs_rui_log_format rui_format;
+};
+
+/*
+ * This is the "rmap update done" log item. It is used to log the fact that
+ * some rmapbt updates mentioned in an earlier rui item have been performed.
+ */
+struct xfs_rud_log_item {
+ struct xfs_log_item rud_item;
+ struct xfs_rui_log_item *rud_ruip;
+ struct xfs_rud_log_format rud_format;
+};
+
+extern struct kmem_zone *xfs_rui_zone;
+extern struct kmem_zone *xfs_rud_zone;
+
+struct xfs_rui_log_item *xfs_rui_init(struct xfs_mount *, uint);
+struct xfs_rud_log_item *xfs_rud_init(struct xfs_mount *,
+ struct xfs_rui_log_item *);
+int xfs_rui_copy_format(struct xfs_log_iovec *buf,
+ struct xfs_rui_log_format *dst_rui_fmt);
+void xfs_rui_item_free(struct xfs_rui_log_item *);
+void xfs_rui_release(struct xfs_rui_log_item *);
+int xfs_rui_recover(struct xfs_mount *mp, struct xfs_rui_log_item *ruip);
+
+#endif /* __XFS_RMAP_ITEM_H__ */