1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * Copyright (C) 2016 Oracle. All Rights Reserved. 4 * Author: Darrick J. Wong <darrick.wong@oracle.com> 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 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; 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 74 #endif /* __XFS_REFCOUNT_ITEM_H__ */ 75