1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Copyright (C) 2016 Oracle.  All Rights Reserved.
4 * Author: Darrick J. Wong <darrick.wong@oracle.com>
5 */
6#ifndef __XFS_REFCOUNT_H__
7#define __XFS_REFCOUNT_H__
8
9extern int xfs_refcount_lookup_le(struct xfs_btree_cur *cur,
10		xfs_agblock_t bno, int *stat);
11extern int xfs_refcount_lookup_ge(struct xfs_btree_cur *cur,
12		xfs_agblock_t bno, int *stat);
13extern int xfs_refcount_lookup_eq(struct xfs_btree_cur *cur,
14		xfs_agblock_t bno, int *stat);
15extern int xfs_refcount_get_rec(struct xfs_btree_cur *cur,
16		struct xfs_refcount_irec *irec, int *stat);
17
18enum xfs_refcount_intent_type {
19	XFS_REFCOUNT_INCREASE = 1,
20	XFS_REFCOUNT_DECREASE,
21	XFS_REFCOUNT_ALLOC_COW,
22	XFS_REFCOUNT_FREE_COW,
23};
24
25struct xfs_refcount_intent {
26	struct list_head			ri_list;
27	enum xfs_refcount_intent_type		ri_type;
28	xfs_fsblock_t				ri_startblock;
29	xfs_extlen_t				ri_blockcount;
30};
31
32void xfs_refcount_increase_extent(struct xfs_trans *tp,
33		struct xfs_bmbt_irec *irec);
34void xfs_refcount_decrease_extent(struct xfs_trans *tp,
35		struct xfs_bmbt_irec *irec);
36
37extern void xfs_refcount_finish_one_cleanup(struct xfs_trans *tp,
38		struct xfs_btree_cur *rcur, int error);
39extern int xfs_refcount_finish_one(struct xfs_trans *tp,
40		enum xfs_refcount_intent_type type, xfs_fsblock_t startblock,
41		xfs_extlen_t blockcount, xfs_fsblock_t *new_fsb,
42		xfs_extlen_t *new_len, struct xfs_btree_cur **pcur);
43
44extern int xfs_refcount_find_shared(struct xfs_btree_cur *cur,
45		xfs_agblock_t agbno, xfs_extlen_t aglen, xfs_agblock_t *fbno,
46		xfs_extlen_t *flen, bool find_end_of_shared);
47
48void xfs_refcount_alloc_cow_extent(struct xfs_trans *tp, xfs_fsblock_t fsb,
49		xfs_extlen_t len);
50void xfs_refcount_free_cow_extent(struct xfs_trans *tp, xfs_fsblock_t fsb,
51		xfs_extlen_t len);
52extern int xfs_refcount_recover_cow_leftovers(struct xfs_mount *mp,
53		xfs_agnumber_t agno);
54
55/*
56 * While we're adjusting the refcounts records of an extent, we have
57 * to keep an eye on the number of extents we're dirtying -- run too
58 * many in a single transaction and we'll exceed the transaction's
59 * reservation and crash the fs.  Each record adds 12 bytes to the
60 * log (plus any key updates) so we'll conservatively assume 32 bytes
61 * per record.  We must also leave space for btree splits on both ends
62 * of the range and space for the CUD and a new CUI.
63 */
64#define XFS_REFCOUNT_ITEM_OVERHEAD	32
65
66static inline xfs_fileoff_t xfs_refcount_max_unmap(int log_res)
67{
68	return (log_res * 3 / 4) / XFS_REFCOUNT_ITEM_OVERHEAD;
69}
70
71extern int xfs_refcount_has_record(struct xfs_btree_cur *cur,
72		xfs_agblock_t bno, xfs_extlen_t len, bool *exists);
73union xfs_btree_rec;
74extern void xfs_refcount_btrec_to_irec(union xfs_btree_rec *rec,
75		struct xfs_refcount_irec *irec);
76extern int xfs_refcount_insert(struct xfs_btree_cur *cur,
77		struct xfs_refcount_irec *irec, int *stat);
78
79#endif	/* __XFS_REFCOUNT_H__ */
80