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_RMAP_ITEM_H__ 7 #define __XFS_RMAP_ITEM_H__ 8 9 /* 10 * There are (currently) three pairs of rmap btree redo item types: map, unmap, 11 * and convert. The common abbreviations for these are RUI (rmap update 12 * intent) and RUD (rmap update done). The redo item type is encoded in the 13 * 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 transaction 17 * that records the associated rmapbt updates. Typically, the first 18 * transaction will record a bmbt update, followed by some number of 19 * transactions containing rmapbt updates, and finally transactions with any 20 * bnobt/cntbt updates. 21 * 22 * Should the system crash after the commit of the first transaction but 23 * before the commit of the final transaction in a series, log recovery will 24 * use the redo information recorded by the intent items to replay the 25 * (rmapbt/bnobt/cntbt) metadata updates in the non-first transaction. 26 */ 27 28 /* kernel only RUI/RUD definitions */ 29 30 struct xfs_mount; 31 struct kmem_cache; 32 33 /* 34 * Max number of extents in fast allocation path. 35 */ 36 #define XFS_RUI_MAX_FAST_EXTENTS 16 37 38 /* 39 * This is the "rmap update intent" log item. It is used to log the fact that 40 * some reverse mappings need to change. It is used in conjunction with the 41 * "rmap update done" log item described below. 42 * 43 * These log items follow the same rules as struct xfs_efi_log_item; see the 44 * comments about that structure (in xfs_extfree_item.h) for more details. 45 */ 46 struct xfs_rui_log_item { 47 struct xfs_log_item rui_item; 48 atomic_t rui_refcount; 49 atomic_t rui_next_extent; 50 struct xfs_rui_log_format rui_format; 51 }; 52 53 static inline size_t xfs_rui_log_item_sizeof(unsigned int nr)54xfs_rui_log_item_sizeof( 55 unsigned int nr) 56 { 57 return offsetof(struct xfs_rui_log_item, rui_format) + 58 xfs_rui_log_format_sizeof(nr); 59 } 60 61 /* 62 * This is the "rmap update done" log item. It is used to log the fact that 63 * some rmapbt updates mentioned in an earlier rui item have been performed. 64 */ 65 struct xfs_rud_log_item { 66 struct xfs_log_item rud_item; 67 struct xfs_rui_log_item *rud_ruip; 68 struct xfs_rud_log_format rud_format; 69 }; 70 71 extern struct kmem_cache *xfs_rui_cache; 72 extern struct kmem_cache *xfs_rud_cache; 73 74 #endif /* __XFS_RMAP_ITEM_H__ */ 75