1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
|
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _BCACHEFS_BTREE_GC_H
#define _BCACHEFS_BTREE_GC_H
#include "bkey.h"
#include "btree_gc_types.h"
#include "btree_types.h"
int bch2_check_topology(struct bch_fs *);
int bch2_check_allocations(struct bch_fs *);
/*
* For concurrent mark and sweep (with other index updates), we define a total
* ordering of _all_ references GC walks:
*
* Note that some references will have the same GC position as others - e.g.
* everything within the same btree node; in those cases we're relying on
* whatever locking exists for where those references live, i.e. the write lock
* on a btree node.
*
* That locking is also required to ensure GC doesn't pass the updater in
* between the updater adding/removing the reference and updating the GC marks;
* without that, we would at best double count sometimes.
*
* That part is important - whenever calling bch2_mark_pointers(), a lock _must_
* be held that prevents GC from passing the position the updater is at.
*
* (What about the start of gc, when we're clearing all the marks? GC clears the
* mark with the gc pos seqlock held, and bch_mark_bucket checks against the gc
* position inside its cmpxchg loop, so crap magically works).
*/
/* Position of (the start of) a gc phase: */
static inline struct gc_pos gc_phase(enum gc_phase phase)
{
return (struct gc_pos) { .phase = phase, };
}
static inline struct gc_pos gc_pos_btree(enum btree_id btree, unsigned level,
struct bpos pos)
{
return (struct gc_pos) {
.phase = GC_PHASE_btree,
.btree = btree,
.level = level,
.pos = pos,
};
}
static inline int gc_btree_order(enum btree_id btree)
{
if (btree == BTREE_ID_alloc)
return -2;
if (btree == BTREE_ID_stripes)
return -1;
return btree;
}
static inline int gc_pos_cmp(struct gc_pos l, struct gc_pos r)
{
return cmp_int(l.phase, r.phase) ?:
cmp_int(gc_btree_order(l.btree),
gc_btree_order(r.btree)) ?:
cmp_int(l.level, r.level) ?:
bpos_cmp(l.pos, r.pos);
}
static inline bool gc_visited(struct bch_fs *c, struct gc_pos pos)
{
unsigned seq;
bool ret;
do {
seq = read_seqcount_begin(&c->gc_pos_lock);
ret = gc_pos_cmp(pos, c->gc_pos) <= 0;
} while (read_seqcount_retry(&c->gc_pos_lock, seq));
return ret;
}
void bch2_gc_pos_to_text(struct printbuf *, struct gc_pos *);
int bch2_gc_gens(struct bch_fs *);
void bch2_gc_gens_async(struct bch_fs *);
void bch2_fs_gc_init(struct bch_fs *);
#endif /* _BCACHEFS_BTREE_GC_H */
|
