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

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

/*
 * There are (currently) two pairs of refcount btree redo item types:
 * increase and decrease.  The log items for these are CUI (refcount
 * update intent) and CUD (refcount 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 refcountbt 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 refcountbt metadata updates.
 */

/* kernel only CUI/CUD definitions */

struct xfs_mount;
struct kmem_zone;

/*
 * Max number of extents in fast allocation path.
 */
#define	XFS_CUI_MAX_FAST_EXTENTS	16

/*
 * This is the "refcount 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 "refcount 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_cui_log_item {
	struct xfs_log_item		cui_item;
	atomic_t			cui_refcount;
	atomic_t			cui_next_extent;
	struct xfs_cui_log_format	cui_format;
};

static inline size_t
xfs_cui_log_item_sizeof(
	unsigned int		nr)
{
	return offsetof(struct xfs_cui_log_item, cui_format) +
			xfs_cui_log_format_sizeof(nr);
}

/*
 * This is the "refcount update done" log item.  It is used to log the
 * fact that some refcountbt updates mentioned in an earlier cui item
 * have been performed.
 */
struct xfs_cud_log_item {
	struct xfs_log_item		cud_item;
	struct xfs_cui_log_item		*cud_cuip;
	struct xfs_cud_log_format	cud_format;
};

extern struct kmem_zone	*xfs_cui_zone;
extern struct kmem_zone	*xfs_cud_zone;

#endif	/* __XFS_REFCOUNT_ITEM_H__ */
Commit	Line	Data
0b61f8a4	1	// SPDX-License-Identifier: GPL-2.0+
baf4bcac DW	2	/*
baf4bcac DW	3	* Copyright (C) 2016 Oracle. All Rights Reserved.
baf4bcac	4	* Author: Darrick J. Wong <[email protected]>
baf4bcac DW	5	*/
	6	#ifndef __XFS_REFCOUNT_ITEM_H__
	7	#define __XFS_REFCOUNT_ITEM_H__
	8
	9	/*
	10	* There are (currently) two pairs of refcount btree redo item types:
	11	* increase and decrease. The log items for these are CUI (refcount
	12	* update intent) and CUD (refcount update done). The redo item type
	13	* is encoded in the flags field of 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
	17	* transaction that records the associated refcountbt updates.
	18	*
	19	* Should the system crash after the commit of the first transaction
	20	* but before the commit of the final transaction in a series, log
	21	* recovery will use the redo information recorded by the intent items
	22	* to replay the refcountbt metadata updates.
	23	*/
	24
	25	/* kernel only CUI/CUD 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_CUI_MAX_FAST_EXTENTS 16
	34
baf4bcac DW	35	/*
	36	* This is the "refcount update intent" log item. It is used to log
	37	* the fact that some reverse mappings need to change. It is used in
	38	* conjunction with the "refcount update done" log item described
	39	* below.
	40	*
	41	* These log items follow the same rules as struct xfs_efi_log_item;
	42	* see the comments about that structure (in xfs_extfree_item.h) for
	43	* more details.
	44	*/
	45	struct xfs_cui_log_item {
	46	struct xfs_log_item cui_item;
	47	atomic_t cui_refcount;
	48	atomic_t cui_next_extent;
baf4bcac DW	49	struct xfs_cui_log_format cui_format;
	50	};
	51
	52	static inline size_t
	53	xfs_cui_log_item_sizeof(
	54	unsigned int nr)
	55	{
	56	return offsetof(struct xfs_cui_log_item, cui_format) +
	57	xfs_cui_log_format_sizeof(nr);
	58	}
	59
	60	/*
	61	* This is the "refcount update done" log item. It is used to log the
	62	* fact that some refcountbt updates mentioned in an earlier cui item
	63	* have been performed.
	64	*/
	65	struct xfs_cud_log_item {
	66	struct xfs_log_item cud_item;
	67	struct xfs_cui_log_item *cud_cuip;
	68	struct xfs_cud_log_format cud_format;
	69	};
	70
	71	extern struct kmem_zone *xfs_cui_zone;
	72	extern struct kmem_zone *xfs_cud_zone;
	73
baf4bcac	74	#endif /* __XFS_REFCOUNT_ITEM_H__ */