1/*
  2 * Copyright (C) 2016 Oracle.  All Rights Reserved.
  3 *
  4 * Author: Darrick J. Wong <darrick.wong@oracle.com>
  5 *
  6 * This program is free software; you can redistribute it and/or
  7 * modify it under the terms of the GNU General Public License
  8 * as published by the Free Software Foundation; either version 2
  9 * of the License, or (at your option) any later version.
 10 *
 11 * This program is distributed in the hope that it would be useful,
 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 14 * GNU General Public License for more details.
 15 *
 16 * You should have received a copy of the GNU General Public License
 17 * along with this program; if not, write the Free Software Foundation,
 18 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
 19 */
 20#ifndef	__XFS_RMAP_ITEM_H__
 21#define	__XFS_RMAP_ITEM_H__
 22
 23/*
 24 * There are (currently) three pairs of rmap btree redo item types: map, unmap,
 25 * and convert.  The common abbreviations for these are RUI (rmap update
 26 * intent) and RUD (rmap update done).  The redo item type is encoded in the
 27 * flags field of each xfs_map_extent.
 28 *
 29 * *I items should be recorded in the *first* of a series of rolled
 30 * transactions, and the *D items should be recorded in the same transaction
 31 * that records the associated rmapbt updates.  Typically, the first
 32 * transaction will record a bmbt update, followed by some number of
 33 * transactions containing rmapbt updates, and finally transactions with any
 34 * bnobt/cntbt updates.
 35 *
 36 * Should the system crash after the commit of the first transaction but
 37 * before the commit of the final transaction in a series, log recovery will
 38 * use the redo information recorded by the intent items to replay the
 39 * (rmapbt/bnobt/cntbt) metadata updates in the non-first transaction.
 40 */
 41
 42/* kernel only RUI/RUD definitions */
 43
 44struct xfs_mount;
 45struct kmem_zone;
 46
 47/*
 48 * Max number of extents in fast allocation path.
 49 */
 50#define	XFS_RUI_MAX_FAST_EXTENTS	16
 51
 52/*
 53 * Define RUI flag bits. Manipulated by set/clear/test_bit operators.
 54 */
 55#define	XFS_RUI_RECOVERED		1
 56
 57/*
 58 * This is the "rmap update intent" log item.  It is used to log the fact that
 59 * some reverse mappings need to change.  It is used in conjunction with the
 60 * "rmap update done" log item described below.
 61 *
 62 * These log items follow the same rules as struct xfs_efi_log_item; see the
 63 * comments about that structure (in xfs_extfree_item.h) for more details.
 64 */
 65struct xfs_rui_log_item {
 66	struct xfs_log_item		rui_item;
 67	atomic_t			rui_refcount;
 68	atomic_t			rui_next_extent;
 69	unsigned long			rui_flags;	/* misc flags */
 70	struct xfs_rui_log_format	rui_format;
 71};
 72
 73static inline size_t
 74xfs_rui_log_item_sizeof(
 75	unsigned int		nr)
 76{
 77	return offsetof(struct xfs_rui_log_item, rui_format) +
 78			xfs_rui_log_format_sizeof(nr);
 79}
 80
 81/*
 82 * This is the "rmap update done" log item.  It is used to log the fact that
 83 * some rmapbt updates mentioned in an earlier rui item have been performed.
 84 */
 85struct xfs_rud_log_item {
 86	struct xfs_log_item		rud_item;
 87	struct xfs_rui_log_item		*rud_ruip;
 88	struct xfs_rud_log_format	rud_format;
 89};
 90
 91extern struct kmem_zone	*xfs_rui_zone;
 92extern struct kmem_zone	*xfs_rud_zone;
 93
 94struct xfs_rui_log_item *xfs_rui_init(struct xfs_mount *, uint);
 95struct xfs_rud_log_item *xfs_rud_init(struct xfs_mount *,
 96		struct xfs_rui_log_item *);
 97int xfs_rui_copy_format(struct xfs_log_iovec *buf,
 98		struct xfs_rui_log_format *dst_rui_fmt);
 99void xfs_rui_item_free(struct xfs_rui_log_item *);
100void xfs_rui_release(struct xfs_rui_log_item *);
101int xfs_rui_recover(struct xfs_mount *mp, struct xfs_rui_log_item *ruip);
102
103#endif	/* __XFS_RMAP_ITEM_H__ */