linux/fs/xfs/libxfs/xfs_defer.h
Darrick J. Wong 9f3afb57d5 xfs: implement deferred bmbt map/unmap operations
Implement deferred versions of the inode block map/unmap functions.
These will be used in subsequent patches to make reflink operations
atomic.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2016-10-04 11:05:44 -07:00

100 lines
3.8 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_DEFER_H__
#define __XFS_DEFER_H__
struct xfs_defer_op_type;
/*
* Save a log intent item and a list of extents, so that we can replay
* whatever action had to happen to the extent list and file the log done
* item.
*/
struct xfs_defer_pending {
const struct xfs_defer_op_type *dfp_type; /* function pointers */
struct list_head dfp_list; /* pending items */
void *dfp_intent; /* log intent item */
void *dfp_done; /* log done item */
struct list_head dfp_work; /* work items */
unsigned int dfp_count; /* # extent items */
};
/*
* Header for deferred operation list.
*
* dop_low is used by the allocator to activate the lowspace algorithm -
* when free space is running low the extent allocator may choose to
* allocate an extent from an AG without leaving sufficient space for
* a btree split when inserting the new extent. In this case the allocator
* will enable the lowspace algorithm which is supposed to allow further
* allocations (such as btree splits and newroots) to allocate from
* sequential AGs. In order to avoid locking AGs out of order the lowspace
* algorithm will start searching for free space from AG 0. If the correct
* transaction reservations have been made then this algorithm will eventually
* find all the space it needs.
*/
enum xfs_defer_ops_type {
XFS_DEFER_OPS_TYPE_BMAP,
XFS_DEFER_OPS_TYPE_REFCOUNT,
XFS_DEFER_OPS_TYPE_RMAP,
XFS_DEFER_OPS_TYPE_FREE,
XFS_DEFER_OPS_TYPE_MAX,
};
#define XFS_DEFER_OPS_NR_INODES 2 /* join up to two inodes */
struct xfs_defer_ops {
bool dop_committed; /* did any trans commit? */
bool dop_low; /* alloc in low mode */
struct list_head dop_intake; /* unlogged pending work */
struct list_head dop_pending; /* logged pending work */
/* relog these inodes with each roll */
struct xfs_inode *dop_inodes[XFS_DEFER_OPS_NR_INODES];
};
void xfs_defer_add(struct xfs_defer_ops *dop, enum xfs_defer_ops_type type,
struct list_head *h);
int xfs_defer_finish(struct xfs_trans **tp, struct xfs_defer_ops *dop,
struct xfs_inode *ip);
void xfs_defer_cancel(struct xfs_defer_ops *dop);
void xfs_defer_init(struct xfs_defer_ops *dop, xfs_fsblock_t *fbp);
bool xfs_defer_has_unfinished_work(struct xfs_defer_ops *dop);
int xfs_defer_join(struct xfs_defer_ops *dop, struct xfs_inode *ip);
/* Description of a deferred type. */
struct xfs_defer_op_type {
enum xfs_defer_ops_type type;
unsigned int max_items;
void (*abort_intent)(void *);
void *(*create_done)(struct xfs_trans *, void *, unsigned int);
int (*finish_item)(struct xfs_trans *, struct xfs_defer_ops *,
struct list_head *, void *, void **);
void (*finish_cleanup)(struct xfs_trans *, void *, int);
void (*cancel_item)(struct list_head *);
int (*diff_items)(void *, struct list_head *, struct list_head *);
void *(*create_intent)(struct xfs_trans *, uint);
void (*log_item)(struct xfs_trans *, void *, struct list_head *);
};
void xfs_defer_init_op_type(const struct xfs_defer_op_type *type);
#endif /* __XFS_DEFER_H__ */