ubuntu-linux-kernel/fs/xfs/xfs_refcount_item.h

103 lines
3.3 KiB
C

/*
* 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_REFCOUNT_ITEM_H__
#define __XFS_REFCOUNT_ITEM_H__
/*
* There are (currently) two pairs of refcount btree redo item types:
* increase and decrease. The log items for these are CUI (refcount
* update intent) and CUD (refcount 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 refcountbt 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 refcountbt metadata updates.
*/
/* kernel only CUI/CUD definitions */
struct xfs_mount;
struct kmem_zone;
/*
* Max number of extents in fast allocation path.
*/
#define XFS_CUI_MAX_FAST_EXTENTS 16
/*
* Define CUI flag bits. Manipulated by set/clear/test_bit operators.
*/
#define XFS_CUI_RECOVERED 1
/*
* This is the "refcount 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 "refcount 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_cui_log_item {
struct xfs_log_item cui_item;
atomic_t cui_refcount;
atomic_t cui_next_extent;
unsigned long cui_flags; /* misc flags */
struct xfs_cui_log_format cui_format;
};
static inline size_t
xfs_cui_log_item_sizeof(
unsigned int nr)
{
return offsetof(struct xfs_cui_log_item, cui_format) +
xfs_cui_log_format_sizeof(nr);
}
/*
* This is the "refcount update done" log item. It is used to log the
* fact that some refcountbt updates mentioned in an earlier cui item
* have been performed.
*/
struct xfs_cud_log_item {
struct xfs_log_item cud_item;
struct xfs_cui_log_item *cud_cuip;
struct xfs_cud_log_format cud_format;
};
extern struct kmem_zone *xfs_cui_zone;
extern struct kmem_zone *xfs_cud_zone;
struct xfs_cui_log_item *xfs_cui_init(struct xfs_mount *, uint);
struct xfs_cud_log_item *xfs_cud_init(struct xfs_mount *,
struct xfs_cui_log_item *);
void xfs_cui_item_free(struct xfs_cui_log_item *);
void xfs_cui_release(struct xfs_cui_log_item *);
int xfs_cui_recover(struct xfs_mount *mp, struct xfs_cui_log_item *cuip,
struct xfs_defer_ops *dfops);
#endif /* __XFS_REFCOUNT_ITEM_H__ */