tegrakernel/kernel/kernel-4.9/fs/xfs/libxfs/xfs_refcount.h

87 lines
3.2 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_H__
#define __XFS_REFCOUNT_H__
extern int xfs_refcount_lookup_le(struct xfs_btree_cur *cur,
xfs_agblock_t bno, int *stat);
extern int xfs_refcount_lookup_ge(struct xfs_btree_cur *cur,
xfs_agblock_t bno, int *stat);
extern int xfs_refcount_get_rec(struct xfs_btree_cur *cur,
struct xfs_refcount_irec *irec, int *stat);
enum xfs_refcount_intent_type {
XFS_REFCOUNT_INCREASE = 1,
XFS_REFCOUNT_DECREASE,
XFS_REFCOUNT_ALLOC_COW,
XFS_REFCOUNT_FREE_COW,
};
struct xfs_refcount_intent {
struct list_head ri_list;
enum xfs_refcount_intent_type ri_type;
xfs_fsblock_t ri_startblock;
xfs_extlen_t ri_blockcount;
};
extern int xfs_refcount_increase_extent(struct xfs_mount *mp,
struct xfs_defer_ops *dfops, struct xfs_bmbt_irec *irec);
extern int xfs_refcount_decrease_extent(struct xfs_mount *mp,
struct xfs_defer_ops *dfops, struct xfs_bmbt_irec *irec);
extern void xfs_refcount_finish_one_cleanup(struct xfs_trans *tp,
struct xfs_btree_cur *rcur, int error);
extern int xfs_refcount_finish_one(struct xfs_trans *tp,
struct xfs_defer_ops *dfops, enum xfs_refcount_intent_type type,
xfs_fsblock_t startblock, xfs_extlen_t blockcount,
xfs_fsblock_t *new_fsb, xfs_extlen_t *new_len,
struct xfs_btree_cur **pcur);
extern int xfs_refcount_find_shared(struct xfs_btree_cur *cur,
xfs_agblock_t agbno, xfs_extlen_t aglen, xfs_agblock_t *fbno,
xfs_extlen_t *flen, bool find_end_of_shared);
extern int xfs_refcount_alloc_cow_extent(struct xfs_mount *mp,
struct xfs_defer_ops *dfops, xfs_fsblock_t fsb,
xfs_extlen_t len);
extern int xfs_refcount_free_cow_extent(struct xfs_mount *mp,
struct xfs_defer_ops *dfops, xfs_fsblock_t fsb,
xfs_extlen_t len);
extern int xfs_refcount_recover_cow_leftovers(struct xfs_mount *mp,
xfs_agnumber_t agno);
/*
* While we're adjusting the refcounts records of an extent, we have
* to keep an eye on the number of extents we're dirtying -- run too
* many in a single transaction and we'll exceed the transaction's
* reservation and crash the fs. Each record adds 12 bytes to the
* log (plus any key updates) so we'll conservatively assume 32 bytes
* per record. We must also leave space for btree splits on both ends
* of the range and space for the CUD and a new CUI.
*/
#define XFS_REFCOUNT_ITEM_OVERHEAD 32
static inline xfs_fileoff_t xfs_refcount_max_unmap(int log_res)
{
return (log_res * 3 / 4) / XFS_REFCOUNT_ITEM_OVERHEAD;
}
#endif /* __XFS_REFCOUNT_H__ */