linux/fs/xfs/libxfs/xfs_refcount.h
Darrick J. Wong 9e253954ac xfs: compact deferred intent item structures
Rearrange these structs to reduce the amount of unused padding bytes.
This saves eight bytes for each of the three structs changed here, which
means they're now all (rmap/bmap are 64 bytes, refc is 32 bytes) even
powers of two.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Chandan Babu R <chandan.babu@oracle.com>
2021-10-22 16:04:36 -07:00

87 lines
2.9 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2016 Oracle. All Rights Reserved.
* Author: Darrick J. Wong <darrick.wong@oracle.com>
*/
#ifndef __XFS_REFCOUNT_H__
#define __XFS_REFCOUNT_H__
struct xfs_trans;
struct xfs_mount;
struct xfs_perag;
struct xfs_btree_cur;
struct xfs_bmbt_irec;
struct xfs_refcount_irec;
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_lookup_eq(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_extlen_t ri_blockcount;
xfs_fsblock_t ri_startblock;
};
void xfs_refcount_increase_extent(struct xfs_trans *tp,
struct xfs_bmbt_irec *irec);
void xfs_refcount_decrease_extent(struct xfs_trans *tp,
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,
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);
void xfs_refcount_alloc_cow_extent(struct xfs_trans *tp, xfs_fsblock_t fsb,
xfs_extlen_t len);
void xfs_refcount_free_cow_extent(struct xfs_trans *tp, xfs_fsblock_t fsb,
xfs_extlen_t len);
extern int xfs_refcount_recover_cow_leftovers(struct xfs_mount *mp,
struct xfs_perag *pag);
/*
* 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;
}
extern int xfs_refcount_has_record(struct xfs_btree_cur *cur,
xfs_agblock_t bno, xfs_extlen_t len, bool *exists);
union xfs_btree_rec;
extern void xfs_refcount_btrec_to_irec(const union xfs_btree_rec *rec,
struct xfs_refcount_irec *irec);
extern int xfs_refcount_insert(struct xfs_btree_cur *cur,
struct xfs_refcount_irec *irec, int *stat);
#endif /* __XFS_REFCOUNT_H__ */