1 /* 2 * Copyright (C) 2016 Oracle. All Rights Reserved. 3 * 4 * Author: Darrick J. Wong <darrick.wong@oracle.com> 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License 8 * as published by the Free Software Foundation; either version 2 9 * of the License, or (at your option) any later version. 10 * 11 * This program is distributed in the hope that it would be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, write the Free Software Foundation, 18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. 19 */ 20 #ifndef __XFS_BMAP_ITEM_H__ 21 #define __XFS_BMAP_ITEM_H__ 22 23 /* 24 * There are (currently) two pairs of bmap btree redo item types: map & unmap. 25 * The common abbreviations for these are BUI (bmap update intent) and BUD 26 * (bmap update done). The redo item type is encoded in the flags field of 27 * each xfs_map_extent. 28 * 29 * *I items should be recorded in the *first* of a series of rolled 30 * transactions, and the *D items should be recorded in the same transaction 31 * that records the associated bmbt updates. 32 * 33 * Should the system crash after the commit of the first transaction but 34 * before the commit of the final transaction in a series, log recovery will 35 * use the redo information recorded by the intent items to replay the 36 * bmbt metadata updates in the non-first transaction. 37 */ 38 39 /* kernel only BUI/BUD definitions */ 40 41 struct xfs_mount; 42 struct kmem_zone; 43 44 /* 45 * Max number of extents in fast allocation path. 46 */ 47 #define XFS_BUI_MAX_FAST_EXTENTS 1 48 49 /* 50 * Define BUI flag bits. Manipulated by set/clear/test_bit operators. 51 */ 52 #define XFS_BUI_RECOVERED 1 53 54 /* 55 * This is the "bmap update intent" log item. It is used to log the fact that 56 * some reverse mappings need to change. It is used in conjunction with the 57 * "bmap update done" log item described below. 58 * 59 * These log items follow the same rules as struct xfs_efi_log_item; see the 60 * comments about that structure (in xfs_extfree_item.h) for more details. 61 */ 62 struct xfs_bui_log_item { 63 struct xfs_log_item bui_item; 64 atomic_t bui_refcount; 65 atomic_t bui_next_extent; 66 unsigned long bui_flags; /* misc flags */ 67 struct xfs_bui_log_format bui_format; 68 }; 69 70 static inline size_t 71 xfs_bui_log_item_sizeof( 72 unsigned int nr) 73 { 74 return offsetof(struct xfs_bui_log_item, bui_format) + 75 xfs_bui_log_format_sizeof(nr); 76 } 77 78 /* 79 * This is the "bmap update done" log item. It is used to log the fact that 80 * some bmbt updates mentioned in an earlier bui item have been performed. 81 */ 82 struct xfs_bud_log_item { 83 struct xfs_log_item bud_item; 84 struct xfs_bui_log_item *bud_buip; 85 struct xfs_bud_log_format bud_format; 86 }; 87 88 extern struct kmem_zone *xfs_bui_zone; 89 extern struct kmem_zone *xfs_bud_zone; 90 91 struct xfs_bui_log_item *xfs_bui_init(struct xfs_mount *); 92 struct xfs_bud_log_item *xfs_bud_init(struct xfs_mount *, 93 struct xfs_bui_log_item *); 94 void xfs_bui_item_free(struct xfs_bui_log_item *); 95 void xfs_bui_release(struct xfs_bui_log_item *); 96 int xfs_bui_recover(struct xfs_mount *mp, struct xfs_bui_log_item *buip); 97 98 #endif /* __XFS_BMAP_ITEM_H__ */ 99