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Diffstat (limited to 'fs/xfs/xfs_rmap_item.h')
| -rw-r--r-- | fs/xfs/xfs_rmap_item.h | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/fs/xfs/xfs_rmap_item.h b/fs/xfs/xfs_rmap_item.h new file mode 100644 index 000000000000..bd36ab50c0fe --- /dev/null +++ b/fs/xfs/xfs_rmap_item.h @@ -0,0 +1,100 @@ +/* + * Copyright (C) 2016 Oracle. All Rights Reserved. + * + * Author: Darrick J. Wong <darrick.wong@oracle.com> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it would be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. + */ +#ifndef __XFS_RMAP_ITEM_H__ +#define __XFS_RMAP_ITEM_H__ + +/* + * There are (currently) three pairs of rmap btree redo item types: map, unmap, + * and convert. The common abbreviations for these are RUI (rmap update + * intent) and RUD (rmap update done). The redo item type is encoded in the + * flags field of each xfs_map_extent. + * + * *I items should be recorded in the *first* of a series of rolled + * transactions, and the *D items should be recorded in the same transaction + * that records the associated rmapbt updates. Typically, the first + * transaction will record a bmbt update, followed by some number of + * transactions containing rmapbt updates, and finally transactions with any + * bnobt/cntbt updates. + * + * Should the system crash after the commit of the first transaction but + * before the commit of the final transaction in a series, log recovery will + * use the redo information recorded by the intent items to replay the + * (rmapbt/bnobt/cntbt) metadata updates in the non-first transaction. + */ + +/* kernel only RUI/RUD definitions */ + +struct xfs_mount; +struct kmem_zone; + +/* + * Max number of extents in fast allocation path. + */ +#define XFS_RUI_MAX_FAST_EXTENTS 16 + +/* + * Define RUI flag bits. Manipulated by set/clear/test_bit operators. + */ +#define XFS_RUI_RECOVERED 1 + +/* + * This is the "rmap update intent" log item. It is used to log the fact that + * some reverse mappings need to change. It is used in conjunction with the + * "rmap update done" log item described below. + * + * These log items follow the same rules as struct xfs_efi_log_item; see the + * comments about that structure (in xfs_extfree_item.h) for more details. + */ +struct xfs_rui_log_item { + struct xfs_log_item rui_item; + atomic_t rui_refcount; + atomic_t rui_next_extent; + unsigned long rui_flags; /* misc flags */ + struct xfs_rui_log_format rui_format; +}; + +/* + * This is the "rmap update done" log item. It is used to log the fact that + * some rmapbt updates mentioned in an earlier rui item have been performed. + */ +struct xfs_rud_log_item { + struct xfs_log_item rud_item; + struct xfs_rui_log_item *rud_ruip; + uint rud_next_extent; + struct xfs_rud_log_format rud_format; +}; + +/* + * Max number of extents in fast allocation path. + */ +#define XFS_RUD_MAX_FAST_EXTENTS 16 + +extern struct kmem_zone *xfs_rui_zone; +extern struct kmem_zone *xfs_rud_zone; + +struct xfs_rui_log_item *xfs_rui_init(struct xfs_mount *, uint); +struct xfs_rud_log_item *xfs_rud_init(struct xfs_mount *, + struct xfs_rui_log_item *, uint); +int xfs_rui_copy_format(struct xfs_log_iovec *buf, + struct xfs_rui_log_format *dst_rui_fmt); +void xfs_rui_item_free(struct xfs_rui_log_item *); +void xfs_rui_release(struct xfs_rui_log_item *); + +#endif /* __XFS_RMAP_ITEM_H__ */ |