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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 : struct xfs_trans;
10 : struct xfs_mount;
11 : struct xfs_perag;
12 : struct xfs_btree_cur;
13 : struct xfs_bmbt_irec;
14 : struct xfs_refcount_irec;
15 :
16 : extern int xfs_refcount_lookup_le(struct xfs_btree_cur *cur,
17 : enum xfs_refc_domain domain, xfs_agblock_t bno, int *stat);
18 : extern int xfs_refcount_lookup_ge(struct xfs_btree_cur *cur,
19 : enum xfs_refc_domain domain, xfs_agblock_t bno, int *stat);
20 : extern int xfs_refcount_lookup_eq(struct xfs_btree_cur *cur,
21 : enum xfs_refc_domain domain, xfs_agblock_t bno, int *stat);
22 : extern int xfs_refcount_get_rec(struct xfs_btree_cur *cur,
23 : struct xfs_refcount_irec *irec, int *stat);
24 :
25 : static inline uint32_t
26 : xfs_refcount_encode_startblock(
27 : xfs_agblock_t startblock,
28 : enum xfs_refc_domain domain)
29 : {
30 31870060528 : uint32_t start;
31 :
32 : /*
33 : * low level btree operations need to handle the generic btree range
34 : * query functions (which set rc_domain == -1U), so we check that the
35 : * domain is /not/ shared.
36 : */
37 31870060528 : start = startblock & ~XFS_REFC_COWFLAG;
38 31870060528 : if (domain != XFS_REFC_DOMAIN_SHARED)
39 8482556390 : start |= XFS_REFC_COWFLAG;
40 :
41 31870060528 : return start;
42 : }
43 :
44 : enum xfs_refcount_intent_type {
45 : XFS_REFCOUNT_INCREASE = 1,
46 : XFS_REFCOUNT_DECREASE,
47 : XFS_REFCOUNT_ALLOC_COW,
48 : XFS_REFCOUNT_FREE_COW,
49 : };
50 :
51 : struct xfs_refcount_intent {
52 : struct list_head ri_list;
53 : struct xfs_perag *ri_pag;
54 : enum xfs_refcount_intent_type ri_type;
55 : xfs_extlen_t ri_blockcount;
56 : xfs_fsblock_t ri_startblock;
57 : };
58 :
59 : /* Check that the refcount is appropriate for the record domain. */
60 : static inline bool
61 2466626178 : xfs_refcount_check_domain(
62 : const struct xfs_refcount_irec *irec)
63 : {
64 2466626178 : if (irec->rc_domain == XFS_REFC_DOMAIN_COW && irec->rc_refcount != 1)
65 : return false;
66 2466626181 : if (irec->rc_domain == XFS_REFC_DOMAIN_SHARED && irec->rc_refcount < 2)
67 0 : return false;
68 : return true;
69 : }
70 :
71 : void xfs_refcount_update_get_group(struct xfs_mount *mp,
72 : struct xfs_refcount_intent *ri);
73 :
74 : void xfs_refcount_increase_extent(struct xfs_trans *tp,
75 : struct xfs_bmbt_irec *irec);
76 : void xfs_refcount_decrease_extent(struct xfs_trans *tp,
77 : struct xfs_bmbt_irec *irec);
78 :
79 : extern void xfs_refcount_finish_one_cleanup(struct xfs_trans *tp,
80 : struct xfs_btree_cur *rcur, int error);
81 : extern int xfs_refcount_finish_one(struct xfs_trans *tp,
82 : struct xfs_refcount_intent *ri, struct xfs_btree_cur **pcur);
83 :
84 : extern int xfs_refcount_find_shared(struct xfs_btree_cur *cur,
85 : xfs_agblock_t agbno, xfs_extlen_t aglen, xfs_agblock_t *fbno,
86 : xfs_extlen_t *flen, bool find_end_of_shared);
87 :
88 : void xfs_refcount_alloc_cow_extent(struct xfs_trans *tp, xfs_fsblock_t fsb,
89 : xfs_extlen_t len);
90 : void xfs_refcount_free_cow_extent(struct xfs_trans *tp, xfs_fsblock_t fsb,
91 : xfs_extlen_t len);
92 : extern int xfs_refcount_recover_cow_leftovers(struct xfs_mount *mp,
93 : struct xfs_perag *pag);
94 :
95 : /*
96 : * While we're adjusting the refcounts records of an extent, we have
97 : * to keep an eye on the number of extents we're dirtying -- run too
98 : * many in a single transaction and we'll exceed the transaction's
99 : * reservation and crash the fs. Each record adds 12 bytes to the
100 : * log (plus any key updates) so we'll conservatively assume 32 bytes
101 : * per record. We must also leave space for btree splits on both ends
102 : * of the range and space for the CUD and a new CUI.
103 : *
104 : * Each EFI that we attach to the transaction is assumed to consume ~32 bytes.
105 : * This is a low estimate for an EFI tracking a single extent (16 bytes for the
106 : * EFI header, 16 for the extent, and 12 for the xlog op header), but the
107 : * estimate is acceptable if there's more than one extent being freed.
108 : * In the worst case of freeing every other block during a refcount decrease
109 : * operation, we amortize the space used for one EFI log item across 16
110 : * extents.
111 : */
112 : #define XFS_REFCOUNT_ITEM_OVERHEAD 32
113 :
114 : extern int xfs_refcount_has_records(struct xfs_btree_cur *cur,
115 : enum xfs_refc_domain domain, xfs_agblock_t bno,
116 : xfs_extlen_t len, enum xbtree_recpacking *outcome);
117 : union xfs_btree_rec;
118 : extern void xfs_refcount_btrec_to_irec(const union xfs_btree_rec *rec,
119 : struct xfs_refcount_irec *irec);
120 : xfs_failaddr_t xfs_refcount_check_perag_irec(struct xfs_perag *pag,
121 : const struct xfs_refcount_irec *irec);
122 : xfs_failaddr_t xfs_refcount_check_irec(struct xfs_btree_cur *cur,
123 : const struct xfs_refcount_irec *irec);
124 : extern int xfs_refcount_insert(struct xfs_btree_cur *cur,
125 : struct xfs_refcount_irec *irec, int *stat);
126 :
127 : extern struct kmem_cache *xfs_refcount_intent_cache;
128 :
129 : int __init xfs_refcount_intent_init_cache(void);
130 : void xfs_refcount_intent_destroy_cache(void);
131 :
132 : typedef int (*xfs_refcount_query_range_fn)(
133 : struct xfs_btree_cur *cur,
134 : const struct xfs_refcount_irec *rec,
135 : void *priv);
136 :
137 : int xfs_refcount_query_range(struct xfs_btree_cur *cur,
138 : const struct xfs_refcount_irec *low_rec,
139 : const struct xfs_refcount_irec *high_rec,
140 : xfs_refcount_query_range_fn fn, void *priv);
141 :
142 : #endif /* __XFS_REFCOUNT_H__ */
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