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
xfs_refcount_encode_startblock(xfs_agblock_t startblock,enum xfs_refc_domain domain)26 xfs_refcount_encode_startblock(
27 xfs_agblock_t startblock,
28 enum xfs_refc_domain domain)
29 {
30 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 start = startblock & ~XFS_REFC_COWFLAG;
38 if (domain != XFS_REFC_DOMAIN_SHARED)
39 start |= XFS_REFC_COWFLAG;
40
41 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 #define XFS_REFCOUNT_INTENT_STRINGS \
52 { XFS_REFCOUNT_INCREASE, "incr" }, \
53 { XFS_REFCOUNT_DECREASE, "decr" }, \
54 { XFS_REFCOUNT_ALLOC_COW, "alloc_cow" }, \
55 { XFS_REFCOUNT_FREE_COW, "free_cow" }
56
57 struct xfs_refcount_intent {
58 struct list_head ri_list;
59 struct xfs_perag *ri_pag;
60 enum xfs_refcount_intent_type ri_type;
61 xfs_extlen_t ri_blockcount;
62 xfs_fsblock_t ri_startblock;
63 };
64
65 /* Check that the refcount is appropriate for the record domain. */
66 static inline bool
xfs_refcount_check_domain(const struct xfs_refcount_irec * irec)67 xfs_refcount_check_domain(
68 const struct xfs_refcount_irec *irec)
69 {
70 if (irec->rc_domain == XFS_REFC_DOMAIN_COW && irec->rc_refcount != 1)
71 return false;
72 if (irec->rc_domain == XFS_REFC_DOMAIN_SHARED && irec->rc_refcount < 2)
73 return false;
74 return true;
75 }
76
77 void xfs_refcount_increase_extent(struct xfs_trans *tp,
78 struct xfs_bmbt_irec *irec);
79 void xfs_refcount_decrease_extent(struct xfs_trans *tp,
80 struct xfs_bmbt_irec *irec);
81
82 extern int xfs_refcount_finish_one(struct xfs_trans *tp,
83 struct xfs_refcount_intent *ri, struct xfs_btree_cur **pcur);
84
85 extern int xfs_refcount_find_shared(struct xfs_btree_cur *cur,
86 xfs_agblock_t agbno, xfs_extlen_t aglen, xfs_agblock_t *fbno,
87 xfs_extlen_t *flen, bool find_end_of_shared);
88
89 void xfs_refcount_alloc_cow_extent(struct xfs_trans *tp, xfs_fsblock_t fsb,
90 xfs_extlen_t len);
91 void xfs_refcount_free_cow_extent(struct xfs_trans *tp, xfs_fsblock_t fsb,
92 xfs_extlen_t len);
93 extern int xfs_refcount_recover_cow_leftovers(struct xfs_mount *mp,
94 struct xfs_perag *pag);
95
96 /*
97 * While we're adjusting the refcounts records of an extent, we have
98 * to keep an eye on the number of extents we're dirtying -- run too
99 * many in a single transaction and we'll exceed the transaction's
100 * reservation and crash the fs. Each record adds 12 bytes to the
101 * log (plus any key updates) so we'll conservatively assume 32 bytes
102 * per record. We must also leave space for btree splits on both ends
103 * of the range and space for the CUD and a new CUI.
104 *
105 * Each EFI that we attach to the transaction is assumed to consume ~32 bytes.
106 * This is a low estimate for an EFI tracking a single extent (16 bytes for the
107 * EFI header, 16 for the extent, and 12 for the xlog op header), but the
108 * estimate is acceptable if there's more than one extent being freed.
109 * In the worst case of freeing every other block during a refcount decrease
110 * operation, we amortize the space used for one EFI log item across 16
111 * extents.
112 */
113 #define XFS_REFCOUNT_ITEM_OVERHEAD 32
114
115 extern int xfs_refcount_has_records(struct xfs_btree_cur *cur,
116 enum xfs_refc_domain domain, xfs_agblock_t bno,
117 xfs_extlen_t len, enum xbtree_recpacking *outcome);
118 union xfs_btree_rec;
119 extern void xfs_refcount_btrec_to_irec(const union xfs_btree_rec *rec,
120 struct xfs_refcount_irec *irec);
121 xfs_failaddr_t xfs_refcount_check_irec(struct xfs_perag *pag,
122 const struct xfs_refcount_irec *irec);
123 extern int xfs_refcount_insert(struct xfs_btree_cur *cur,
124 struct xfs_refcount_irec *irec, int *stat);
125
126 extern struct kmem_cache *xfs_refcount_intent_cache;
127
128 int __init xfs_refcount_intent_init_cache(void);
129 void xfs_refcount_intent_destroy_cache(void);
130
131 typedef int (*xfs_refcount_query_range_fn)(
132 struct xfs_btree_cur *cur,
133 const struct xfs_refcount_irec *rec,
134 void *priv);
135
136 int xfs_refcount_query_range(struct xfs_btree_cur *cur,
137 const struct xfs_refcount_irec *low_rec,
138 const struct xfs_refcount_irec *high_rec,
139 xfs_refcount_query_range_fn fn, void *priv);
140
141 #endif /* __XFS_REFCOUNT_H__ */
142