// SPDX-License-Identifier: GPL-2.0+ /* * Copyright (C) 2016 Oracle. All Rights Reserved. * Author: Darrick J. Wong <darrick.wong@oracle.com> */ #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_cache; /* * 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_cache *xfs_cui_cache; extern struct kmem_cache *xfs_cud_cache; #endif /* __XFS_REFCOUNT_ITEM_H__ */