[linux.git] / fs / xfs / xfs_bmap_item.h

// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2016 Oracle.  All Rights Reserved.
 * Author: Darrick J. Wong <[email protected]>
 */
#ifndef	__XFS_BMAP_ITEM_H__
#define	__XFS_BMAP_ITEM_H__

/*
 * There are (currently) two pairs of bmap btree redo item types: map & unmap.
 * The common abbreviations for these are BUI (bmap update intent) and BUD
 * (bmap 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 bmbt 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
 * bmbt metadata updates in the non-first transaction.
 */

/* kernel only BUI/BUD definitions */

struct xfs_mount;
struct kmem_zone;

/*
 * Max number of extents in fast allocation path.
 */
#define	XFS_BUI_MAX_FAST_EXTENTS	1

/*
 * This is the "bmap 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
 * "bmap 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_bui_log_item {
	struct xfs_log_item		bui_item;
	atomic_t			bui_refcount;
	atomic_t			bui_next_extent;
	struct xfs_bui_log_format	bui_format;
};

static inline size_t
xfs_bui_log_item_sizeof(
	unsigned int		nr)
{
	return offsetof(struct xfs_bui_log_item, bui_format) +
			xfs_bui_log_format_sizeof(nr);
}

/*
 * This is the "bmap update done" log item.  It is used to log the fact that
 * some bmbt updates mentioned in an earlier bui item have been performed.
 */
struct xfs_bud_log_item {
	struct xfs_log_item		bud_item;
	struct xfs_bui_log_item		*bud_buip;
	struct xfs_bud_log_format	bud_format;
};

extern struct kmem_zone	*xfs_bui_zone;
extern struct kmem_zone	*xfs_bud_zone;

#endif	/* __XFS_BMAP_ITEM_H__ */
Commit	Line	Data
0b61f8a4	1	// SPDX-License-Identifier: GPL-2.0+
6413a014 DW	2	/*
6413a014 DW	3	* Copyright (C) 2016 Oracle. All Rights Reserved.
6413a014	4	* Author: Darrick J. Wong <[email protected]>
6413a014 DW	5	*/
	6	#ifndef __XFS_BMAP_ITEM_H__
	7	#define __XFS_BMAP_ITEM_H__
	8
	9	/*
	10	* There are (currently) two pairs of bmap btree redo item types: map & unmap.
	11	* The common abbreviations for these are BUI (bmap update intent) and BUD
	12	* (bmap update done). The redo item type is encoded in the flags field of
	13	* each xfs_map_extent.
	14	*
	15	* I items should be recorded in the first* of a series of rolled
	16	* transactions, and the *D items should be recorded in the same transaction
	17	* that records the associated bmbt updates.
	18	*
	19	* Should the system crash after the commit of the first transaction but
	20	* before the commit of the final transaction in a series, log recovery will
	21	* use the redo information recorded by the intent items to replay the
	22	* bmbt metadata updates in the non-first transaction.
	23	*/
	24
	25	/* kernel only BUI/BUD definitions */
	26
	27	struct xfs_mount;
	28	struct kmem_zone;
	29
	30	/*
	31	* Max number of extents in fast allocation path.
	32	*/
	33	#define XFS_BUI_MAX_FAST_EXTENTS 1
	34
6413a014 DW	35	/*
	36	* This is the "bmap update intent" log item. It is used to log the fact that
	37	* some reverse mappings need to change. It is used in conjunction with the
	38	* "bmap update done" log item described below.
	39	*
	40	* These log items follow the same rules as struct xfs_efi_log_item; see the
	41	* comments about that structure (in xfs_extfree_item.h) for more details.
	42	*/
	43	struct xfs_bui_log_item {
	44	struct xfs_log_item bui_item;
	45	atomic_t bui_refcount;
	46	atomic_t bui_next_extent;
6413a014 DW	47	struct xfs_bui_log_format bui_format;
	48	};
	49
	50	static inline size_t
	51	xfs_bui_log_item_sizeof(
	52	unsigned int nr)
	53	{
	54	return offsetof(struct xfs_bui_log_item, bui_format) +
	55	xfs_bui_log_format_sizeof(nr);
	56	}
	57
	58	/*
	59	* This is the "bmap update done" log item. It is used to log the fact that
	60	* some bmbt updates mentioned in an earlier bui item have been performed.
	61	*/
	62	struct xfs_bud_log_item {
	63	struct xfs_log_item bud_item;
	64	struct xfs_bui_log_item *bud_buip;
	65	struct xfs_bud_log_format bud_format;
	66	};
	67
	68	extern struct kmem_zone *xfs_bui_zone;
	69	extern struct kmem_zone *xfs_bud_zone;
	70
6413a014	71	#endif /* __XFS_BMAP_ITEM_H__ */