xref: /openbmc/linux/fs/xfs/xfs_bmap_item.h (revision 182696fb)
10b61f8a4SDave Chinner // SPDX-License-Identifier: GPL-2.0+
26413a014SDarrick J. Wong /*
36413a014SDarrick J. Wong  * Copyright (C) 2016 Oracle.  All Rights Reserved.
46413a014SDarrick J. Wong  * Author: Darrick J. Wong <darrick.wong@oracle.com>
56413a014SDarrick J. Wong  */
66413a014SDarrick J. Wong #ifndef	__XFS_BMAP_ITEM_H__
76413a014SDarrick J. Wong #define	__XFS_BMAP_ITEM_H__
86413a014SDarrick J. Wong 
96413a014SDarrick J. Wong /*
106413a014SDarrick J. Wong  * There are (currently) two pairs of bmap btree redo item types: map & unmap.
116413a014SDarrick J. Wong  * The common abbreviations for these are BUI (bmap update intent) and BUD
126413a014SDarrick J. Wong  * (bmap update done).  The redo item type is encoded in the flags field of
136413a014SDarrick J. Wong  * each xfs_map_extent.
146413a014SDarrick J. Wong  *
156413a014SDarrick J. Wong  * *I items should be recorded in the *first* of a series of rolled
166413a014SDarrick J. Wong  * transactions, and the *D items should be recorded in the same transaction
176413a014SDarrick J. Wong  * that records the associated bmbt updates.
186413a014SDarrick J. Wong  *
196413a014SDarrick J. Wong  * Should the system crash after the commit of the first transaction but
206413a014SDarrick J. Wong  * before the commit of the final transaction in a series, log recovery will
216413a014SDarrick J. Wong  * use the redo information recorded by the intent items to replay the
226413a014SDarrick J. Wong  * bmbt metadata updates in the non-first transaction.
236413a014SDarrick J. Wong  */
246413a014SDarrick J. Wong 
256413a014SDarrick J. Wong /* kernel only BUI/BUD definitions */
266413a014SDarrick J. Wong 
276413a014SDarrick J. Wong struct xfs_mount;
28e7720afaSDarrick J. Wong struct kmem_cache;
296413a014SDarrick J. Wong 
306413a014SDarrick J. Wong /*
316413a014SDarrick J. Wong  * Max number of extents in fast allocation path.
326413a014SDarrick J. Wong  */
336413a014SDarrick J. Wong #define	XFS_BUI_MAX_FAST_EXTENTS	1
346413a014SDarrick J. Wong 
356413a014SDarrick J. Wong /*
366413a014SDarrick J. Wong  * This is the "bmap update intent" log item.  It is used to log the fact that
376413a014SDarrick J. Wong  * some reverse mappings need to change.  It is used in conjunction with the
386413a014SDarrick J. Wong  * "bmap update done" log item described below.
396413a014SDarrick J. Wong  *
406413a014SDarrick J. Wong  * These log items follow the same rules as struct xfs_efi_log_item; see the
416413a014SDarrick J. Wong  * comments about that structure (in xfs_extfree_item.h) for more details.
426413a014SDarrick J. Wong  */
436413a014SDarrick J. Wong struct xfs_bui_log_item {
446413a014SDarrick J. Wong 	struct xfs_log_item		bui_item;
456413a014SDarrick J. Wong 	atomic_t			bui_refcount;
466413a014SDarrick J. Wong 	atomic_t			bui_next_extent;
476413a014SDarrick J. Wong 	struct xfs_bui_log_format	bui_format;
486413a014SDarrick J. Wong };
496413a014SDarrick J. Wong 
506413a014SDarrick J. Wong static inline size_t
xfs_bui_log_item_sizeof(unsigned int nr)516413a014SDarrick J. Wong xfs_bui_log_item_sizeof(
526413a014SDarrick J. Wong 	unsigned int		nr)
536413a014SDarrick J. Wong {
546413a014SDarrick J. Wong 	return offsetof(struct xfs_bui_log_item, bui_format) +
556413a014SDarrick J. Wong 			xfs_bui_log_format_sizeof(nr);
566413a014SDarrick J. Wong }
576413a014SDarrick J. Wong 
586413a014SDarrick J. Wong /*
596413a014SDarrick J. Wong  * This is the "bmap update done" log item.  It is used to log the fact that
606413a014SDarrick J. Wong  * some bmbt updates mentioned in an earlier bui item have been performed.
616413a014SDarrick J. Wong  */
626413a014SDarrick J. Wong struct xfs_bud_log_item {
636413a014SDarrick J. Wong 	struct xfs_log_item		bud_item;
646413a014SDarrick J. Wong 	struct xfs_bui_log_item		*bud_buip;
656413a014SDarrick J. Wong 	struct xfs_bud_log_format	bud_format;
666413a014SDarrick J. Wong };
676413a014SDarrick J. Wong 
68*182696fbSDarrick J. Wong extern struct kmem_cache	*xfs_bui_cache;
69*182696fbSDarrick J. Wong extern struct kmem_cache	*xfs_bud_cache;
706413a014SDarrick J. Wong 
716413a014SDarrick J. Wong #endif	/* __XFS_BMAP_ITEM_H__ */
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