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_REFCOUNT_ITEM_H__ 21 #define __XFS_REFCOUNT_ITEM_H__ 22 23 /* 24 * There are (currently) two pairs of refcount btree redo item types: 25 * increase and decrease. The log items for these are CUI (refcount 26 * update intent) and CUD (refcount update done). The redo item type 27 * is encoded in the flags field of 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 31 * transaction that records the associated refcountbt updates. 32 * 33 * Should the system crash after the commit of the first transaction 34 * but before the commit of the final transaction in a series, log 35 * recovery will use the redo information recorded by the intent items 36 * to replay the refcountbt metadata updates. 37 */ 38 39 /* kernel only CUI/CUD 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_CUI_MAX_FAST_EXTENTS 16 48 49 /* 50 * Define CUI flag bits. Manipulated by set/clear/test_bit operators. 51 */ 52 #define XFS_CUI_RECOVERED 1 53 54 /* 55 * This is the "refcount update intent" log item. It is used to log 56 * the fact that some reverse mappings need to change. It is used in 57 * conjunction with the "refcount update done" log item described 58 * below. 59 * 60 * These log items follow the same rules as struct xfs_efi_log_item; 61 * see the comments about that structure (in xfs_extfree_item.h) for 62 * more details. 63 */ 64 struct xfs_cui_log_item { 65 struct xfs_log_item cui_item; 66 atomic_t cui_refcount; 67 atomic_t cui_next_extent; 68 unsigned long cui_flags; /* misc flags */ 69 struct xfs_cui_log_format cui_format; 70 }; 71 72 static inline size_t 73 xfs_cui_log_item_sizeof( 74 unsigned int nr) 75 { 76 return offsetof(struct xfs_cui_log_item, cui_format) + 77 xfs_cui_log_format_sizeof(nr); 78 } 79 80 /* 81 * This is the "refcount update done" log item. It is used to log the 82 * fact that some refcountbt updates mentioned in an earlier cui item 83 * have been performed. 84 */ 85 struct xfs_cud_log_item { 86 struct xfs_log_item cud_item; 87 struct xfs_cui_log_item *cud_cuip; 88 struct xfs_cud_log_format cud_format; 89 }; 90 91 extern struct kmem_zone *xfs_cui_zone; 92 extern struct kmem_zone *xfs_cud_zone; 93 94 struct xfs_cui_log_item *xfs_cui_init(struct xfs_mount *, uint); 95 struct xfs_cud_log_item *xfs_cud_init(struct xfs_mount *, 96 struct xfs_cui_log_item *); 97 void xfs_cui_item_free(struct xfs_cui_log_item *); 98 void xfs_cui_release(struct xfs_cui_log_item *); 99 100 #endif /* __XFS_REFCOUNT_ITEM_H__ */ 101