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_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 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; 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 71 #endif /* __XFS_BMAP_ITEM_H__ */ 72