xref: /linux/fs/xfs/libxfs/xfs_refcount.h (revision d2912cb15bdda8ba4a5dd73396ad62641af2f520)
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 
9 extern int xfs_refcount_lookup_le(struct xfs_btree_cur *cur,
10 		xfs_agblock_t bno, int *stat);
11 extern int xfs_refcount_lookup_ge(struct xfs_btree_cur *cur,
12 		xfs_agblock_t bno, int *stat);
13 extern int xfs_refcount_lookup_eq(struct xfs_btree_cur *cur,
14 		xfs_agblock_t bno, int *stat);
15 extern int xfs_refcount_get_rec(struct xfs_btree_cur *cur,
16 		struct xfs_refcount_irec *irec, int *stat);
17 
18 enum 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 
25 struct 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 
32 extern int xfs_refcount_increase_extent(struct xfs_trans *tp,
33 		struct xfs_bmbt_irec *irec);
34 extern int xfs_refcount_decrease_extent(struct xfs_trans *tp,
35 		struct xfs_bmbt_irec *irec);
36 
37 extern void xfs_refcount_finish_one_cleanup(struct xfs_trans *tp,
38 		struct xfs_btree_cur *rcur, int error);
39 extern 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 
44 extern 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 
48 extern int xfs_refcount_alloc_cow_extent(struct xfs_trans *tp,
49 		xfs_fsblock_t fsb, xfs_extlen_t len);
50 extern int xfs_refcount_free_cow_extent(struct xfs_trans *tp,
51 		xfs_fsblock_t fsb, xfs_extlen_t len);
52 extern 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 
66 static inline xfs_fileoff_t xfs_refcount_max_unmap(int log_res)
67 {
68 	return (log_res * 3 / 4) / XFS_REFCOUNT_ITEM_OVERHEAD;
69 }
70 
71 extern int xfs_refcount_has_record(struct xfs_btree_cur *cur,
72 		xfs_agblock_t bno, xfs_extlen_t len, bool *exists);
73 union xfs_btree_rec;
74 extern void xfs_refcount_btrec_to_irec(union xfs_btree_rec *rec,
75 		struct xfs_refcount_irec *irec);
76 extern int xfs_refcount_insert(struct xfs_btree_cur *cur,
77 		struct xfs_refcount_irec *irec, int *stat);
78 
79 #endif	/* __XFS_REFCOUNT_H__ */
80