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
9struct xfs_trans;
10struct xfs_mount;
11struct xfs_perag;
12struct xfs_btree_cur;
13struct xfs_bmbt_irec;
14struct xfs_refcount_irec;
15struct xfs_rtgroup;
16
17extern int xfs_refcount_lookup_le(struct xfs_btree_cur *cur,
18 enum xfs_refc_domain domain, xfs_agblock_t bno, int *stat);
19extern int xfs_refcount_lookup_ge(struct xfs_btree_cur *cur,
20 enum xfs_refc_domain domain, xfs_agblock_t bno, int *stat);
21extern int xfs_refcount_lookup_eq(struct xfs_btree_cur *cur,
22 enum xfs_refc_domain domain, xfs_agblock_t bno, int *stat);
23extern int xfs_refcount_get_rec(struct xfs_btree_cur *cur,
24 struct xfs_refcount_irec *irec, int *stat);
25
26static inline uint32_t
27xfs_refcount_encode_startblock(
28 xfs_agblock_t startblock,
29 enum xfs_refc_domain domain)
30{
31 uint32_t start;
32
33 /*
34 * low level btree operations need to handle the generic btree range
35 * query functions (which set rc_domain == -1U), so we check that the
36 * domain is /not/ shared.
37 */
38 start = startblock & ~XFS_REFC_COWFLAG;
39 if (domain != XFS_REFC_DOMAIN_SHARED)
40 start |= XFS_REFC_COWFLAG;
41
42 return start;
43}
44
45enum xfs_refcount_intent_type {
46 XFS_REFCOUNT_INCREASE = 1,
47 XFS_REFCOUNT_DECREASE,
48 XFS_REFCOUNT_ALLOC_COW,
49 XFS_REFCOUNT_FREE_COW,
50};
51
52#define XFS_REFCOUNT_INTENT_STRINGS \
53 { XFS_REFCOUNT_INCREASE, "incr" }, \
54 { XFS_REFCOUNT_DECREASE, "decr" }, \
55 { XFS_REFCOUNT_ALLOC_COW, "alloc_cow" }, \
56 { XFS_REFCOUNT_FREE_COW, "free_cow" }
57
58struct xfs_refcount_intent {
59 struct list_head ri_list;
60 struct xfs_group *ri_group;
61 enum xfs_refcount_intent_type ri_type;
62 xfs_extlen_t ri_blockcount;
63 xfs_fsblock_t ri_startblock;
64 bool ri_realtime;
65};
66
67/* Check that the refcount is appropriate for the record domain. */
68static inline bool
69xfs_refcount_check_domain(
70 const struct xfs_refcount_irec *irec)
71{
72 if (irec->rc_domain == XFS_REFC_DOMAIN_COW && irec->rc_refcount != 1)
73 return false;
74 if (irec->rc_domain == XFS_REFC_DOMAIN_SHARED && irec->rc_refcount < 2)
75 return false;
76 return true;
77}
78
79void xfs_refcount_increase_extent(struct xfs_trans *tp, bool isrt,
80 struct xfs_bmbt_irec *irec);
81void xfs_refcount_decrease_extent(struct xfs_trans *tp, bool isrt,
82 struct xfs_bmbt_irec *irec);
83
84int xfs_refcount_finish_one(struct xfs_trans *tp,
85 struct xfs_refcount_intent *ri, struct xfs_btree_cur **pcur);
86int xfs_rtrefcount_finish_one(struct xfs_trans *tp,
87 struct xfs_refcount_intent *ri, struct xfs_btree_cur **pcur);
88
89extern int xfs_refcount_find_shared(struct xfs_btree_cur *cur,
90 xfs_agblock_t agbno, xfs_extlen_t aglen, xfs_agblock_t *fbno,
91 xfs_extlen_t *flen, bool find_end_of_shared);
92
93void xfs_refcount_alloc_cow_extent(struct xfs_trans *tp, bool isrt,
94 xfs_fsblock_t fsb, xfs_extlen_t len);
95void xfs_refcount_free_cow_extent(struct xfs_trans *tp, bool isrt,
96 xfs_fsblock_t fsb, xfs_extlen_t len);
97int xfs_refcount_recover_cow_leftovers(struct xfs_group *xg);
98
99/*
100 * While we're adjusting the refcounts records of an extent, we have
101 * to keep an eye on the number of extents we're dirtying -- run too
102 * many in a single transaction and we'll exceed the transaction's
103 * reservation and crash the fs. Each record adds 12 bytes to the
104 * log (plus any key updates) so we'll conservatively assume 32 bytes
105 * per record. We must also leave space for btree splits on both ends
106 * of the range and space for the CUD and a new CUI.
107 *
108 * Each EFI that we attach to the transaction is assumed to consume ~32 bytes.
109 * This is a low estimate for an EFI tracking a single extent (16 bytes for the
110 * EFI header, 16 for the extent, and 12 for the xlog op header), but the
111 * estimate is acceptable if there's more than one extent being freed.
112 * In the worst case of freeing every other block during a refcount decrease
113 * operation, we amortize the space used for one EFI log item across 16
114 * extents.
115 */
116#define XFS_REFCOUNT_ITEM_OVERHEAD 32
117
118extern int xfs_refcount_has_records(struct xfs_btree_cur *cur,
119 enum xfs_refc_domain domain, xfs_agblock_t bno,
120 xfs_extlen_t len, enum xbtree_recpacking *outcome);
121union xfs_btree_rec;
122extern void xfs_refcount_btrec_to_irec(const union xfs_btree_rec *rec,
123 struct xfs_refcount_irec *irec);
124xfs_failaddr_t xfs_refcount_check_irec(struct xfs_perag *pag,
125 const struct xfs_refcount_irec *irec);
126xfs_failaddr_t xfs_rtrefcount_check_irec(struct xfs_rtgroup *rtg,
127 const struct xfs_refcount_irec *irec);
128extern int xfs_refcount_insert(struct xfs_btree_cur *cur,
129 struct xfs_refcount_irec *irec, int *stat);
130
131extern struct kmem_cache *xfs_refcount_intent_cache;
132
133int __init xfs_refcount_intent_init_cache(void);
134void xfs_refcount_intent_destroy_cache(void);
135
136typedef int (*xfs_refcount_query_range_fn)(
137 struct xfs_btree_cur *cur,
138 const struct xfs_refcount_irec *rec,
139 void *priv);
140
141int xfs_refcount_query_range(struct xfs_btree_cur *cur,
142 const struct xfs_refcount_irec *low_rec,
143 const struct xfs_refcount_irec *high_rec,
144 xfs_refcount_query_range_fn fn, void *priv);
145
146#endif /* __XFS_REFCOUNT_H__ */
147

source code of linux/fs/xfs/libxfs/xfs_refcount.h