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_REFCOUNT_ITEM_H__
 21#define	__XFS_REFCOUNT_ITEM_H__
 22
 23/*
 24 * There are (currently) two pairs of refcount btree redo item types:
 25 * increase and decrease.  The log items for these are CUI (refcount
 26 * update intent) and CUD (refcount update done).  The redo item type
 27 * is encoded in the 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
 31 * transaction that records the associated refcountbt updates.
 32 *
 33 * Should the system crash after the commit of the first transaction
 34 * but before the commit of the final transaction in a series, log
 35 * recovery will use the redo information recorded by the intent items
 36 * to replay the refcountbt metadata updates.
 37 */
 38
 39/* kernel only CUI/CUD definitions */
 40
 41struct xfs_mount;
 42struct kmem_zone;
 43
 44/*
 45 * Max number of extents in fast allocation path.
 46 */
 47#define	XFS_CUI_MAX_FAST_EXTENTS	16
 48
 49/*
 50 * Define CUI flag bits. Manipulated by set/clear/test_bit operators.
 51 */
 52#define	XFS_CUI_RECOVERED		1
 53
 54/*
 55 * This is the "refcount update intent" log item.  It is used to log
 56 * the fact that some reverse mappings need to change.  It is used in
 57 * conjunction with the "refcount update done" log item described
 58 * below.
 59 *
 60 * These log items follow the same rules as struct xfs_efi_log_item;
 61 * see the comments about that structure (in xfs_extfree_item.h) for
 62 * more details.
 63 */
 64struct xfs_cui_log_item {
 65	struct xfs_log_item		cui_item;
 66	atomic_t			cui_refcount;
 67	atomic_t			cui_next_extent;
 68	unsigned long			cui_flags;	/* misc flags */
 69	struct xfs_cui_log_format	cui_format;
 70};
 71
 72static inline size_t
 73xfs_cui_log_item_sizeof(
 74	unsigned int		nr)
 75{
 76	return offsetof(struct xfs_cui_log_item, cui_format) +
 77			xfs_cui_log_format_sizeof(nr);
 78}
 79
 80/*
 81 * This is the "refcount update done" log item.  It is used to log the
 82 * fact that some refcountbt updates mentioned in an earlier cui item
 83 * have been performed.
 84 */
 85struct xfs_cud_log_item {
 86	struct xfs_log_item		cud_item;
 87	struct xfs_cui_log_item		*cud_cuip;
 88	struct xfs_cud_log_format	cud_format;
 89};
 90
 91extern struct kmem_zone	*xfs_cui_zone;
 92extern struct kmem_zone	*xfs_cud_zone;
 93
 94struct xfs_cui_log_item *xfs_cui_init(struct xfs_mount *, uint);
 95struct xfs_cud_log_item *xfs_cud_init(struct xfs_mount *,
 96		struct xfs_cui_log_item *);
 97void xfs_cui_item_free(struct xfs_cui_log_item *);
 98void xfs_cui_release(struct xfs_cui_log_item *);
 99int xfs_cui_recover(struct xfs_mount *mp, struct xfs_cui_log_item *cuip,
100		struct xfs_defer_ops *dfops);
101
102#endif	/* __XFS_REFCOUNT_ITEM_H__ */