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 * Define BUI flag bits. Manipulated by set/clear/test_bit operators. 37 */ 38 #define XFS_BUI_RECOVERED 1 39 40 /* 41 * This is the "bmap update intent" log item. It is used to log the fact that 42 * some reverse mappings need to change. It is used in conjunction with the 43 * "bmap update done" log item described below. 44 * 45 * These log items follow the same rules as struct xfs_efi_log_item; see the 46 * comments about that structure (in xfs_extfree_item.h) for more details. 47 */ 48 struct xfs_bui_log_item { 49 struct xfs_log_item bui_item; 50 atomic_t bui_refcount; 51 atomic_t bui_next_extent; 52 unsigned long bui_flags; /* misc flags */ 53 struct xfs_bui_log_format bui_format; 54 }; 55 56 static inline size_t 57 xfs_bui_log_item_sizeof( 58 unsigned int nr) 59 { 60 return offsetof(struct xfs_bui_log_item, bui_format) + 61 xfs_bui_log_format_sizeof(nr); 62 } 63 64 /* 65 * This is the "bmap update done" log item. It is used to log the fact that 66 * some bmbt updates mentioned in an earlier bui item have been performed. 67 */ 68 struct xfs_bud_log_item { 69 struct xfs_log_item bud_item; 70 struct xfs_bui_log_item *bud_buip; 71 struct xfs_bud_log_format bud_format; 72 }; 73 74 extern struct kmem_zone *xfs_bui_zone; 75 extern struct kmem_zone *xfs_bud_zone; 76 77 struct xfs_bui_log_item *xfs_bui_init(struct xfs_mount *); 78 void xfs_bui_item_free(struct xfs_bui_log_item *); 79 void xfs_bui_release(struct xfs_bui_log_item *); 80 int xfs_bui_recover(struct xfs_trans *parent_tp, struct xfs_bui_log_item *buip); 81 82 #endif /* __XFS_BMAP_ITEM_H__ */ 83