summaryrefslogtreecommitdiffstats
path: root/fs/bcachefs/migrate.c
blob: 38bf75b6bc2d63be62471d2d4f9c28c00efad3dc (plain)
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
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
// SPDX-License-Identifier: GPL-2.0
/*
 * Code for moving data off a device.
 */

#include "bcachefs.h"
#include "btree_update.h"
#include "btree_update_interior.h"
#include "buckets.h"
#include "extents.h"
#include "io.h"
#include "journal.h"
#include "keylist.h"
#include "migrate.h"
#include "move.h"
#include "replicas.h"
#include "super-io.h"

static int drop_dev_ptrs(struct bch_fs *c, struct bkey_s k,
			 unsigned dev_idx, int flags, bool metadata)
{
	unsigned replicas = metadata ? c->opts.metadata_replicas : c->opts.data_replicas;
	unsigned lost = metadata ? BCH_FORCE_IF_METADATA_LOST : BCH_FORCE_IF_DATA_LOST;
	unsigned degraded = metadata ? BCH_FORCE_IF_METADATA_DEGRADED : BCH_FORCE_IF_DATA_DEGRADED;
	unsigned nr_good;

	bch2_bkey_drop_device(k, dev_idx);

	nr_good = bch2_bkey_durability(c, k.s_c);
	if ((!nr_good && !(flags & lost)) ||
	    (nr_good < replicas && !(flags & degraded)))
		return -EINVAL;

	return 0;
}

static int bch2_dev_usrdata_drop(struct bch_fs *c, unsigned dev_idx, int flags)
{
	struct btree_trans trans;
	struct btree_iter *iter;
	struct bkey_s_c k;
	BKEY_PADDED(key) tmp;
	int ret = 0;

	bch2_trans_init(&trans, c);

	iter = bch2_trans_get_iter(&trans, BTREE_ID_EXTENTS,
				   POS_MIN, BTREE_ITER_PREFETCH);

	mutex_lock(&c->replicas_gc_lock);
	bch2_replicas_gc_start(c, (1 << BCH_DATA_USER)|(1 << BCH_DATA_CACHED));


	while ((k = bch2_btree_iter_peek(iter)).k &&
	       !(ret = btree_iter_err(k))) {
		if (!bkey_extent_is_data(k.k) ||
		    !bch2_extent_has_device(bkey_s_c_to_extent(k), dev_idx)) {
			ret = bch2_mark_bkey_replicas(c, k);
			if (ret)
				break;
			bch2_btree_iter_next(iter);
			continue;
		}

		bkey_reassemble(&tmp.key, k);

		ret = drop_dev_ptrs(c, bkey_i_to_s(&tmp.key),
				    dev_idx, flags, false);
		if (ret)
			break;

		/*
		 * If the new extent no longer has any pointers, bch2_extent_normalize()
		 * will do the appropriate thing with it (turning it into a
		 * KEY_TYPE_error key, or just a discard if it was a cached extent)
		 */
		bch2_extent_normalize(c, bkey_i_to_s(&tmp.key));

		/* XXX not sketchy at all */
		iter->pos = bkey_start_pos(&tmp.key.k);

		bch2_trans_update(&trans, BTREE_INSERT_ENTRY(iter, &tmp.key));

		ret = bch2_trans_commit(&trans, NULL, NULL,
					BTREE_INSERT_ATOMIC|
					BTREE_INSERT_NOFAIL);

		/*
		 * don't want to leave ret == -EINTR, since if we raced and
		 * something else overwrote the key we could spuriously return
		 * -EINTR below:
		 */
		if (ret == -EINTR)
			ret = 0;
		if (ret)
			break;
	}

	bch2_trans_exit(&trans);

	bch2_replicas_gc_end(c, ret);
	mutex_unlock(&c->replicas_gc_lock);

	return ret;
}

static int bch2_dev_metadata_drop(struct bch_fs *c, unsigned dev_idx, int flags)
{
	struct btree_iter iter;
	struct closure cl;
	struct btree *b;
	unsigned id;
	int ret;

	/* don't handle this yet: */
	if (flags & BCH_FORCE_IF_METADATA_LOST)
		return -EINVAL;

	closure_init_stack(&cl);

	mutex_lock(&c->replicas_gc_lock);
	bch2_replicas_gc_start(c, 1 << BCH_DATA_BTREE);

	for (id = 0; id < BTREE_ID_NR; id++) {
		for_each_btree_node(&iter, c, id, POS_MIN, BTREE_ITER_PREFETCH, b) {
			__BKEY_PADDED(k, BKEY_BTREE_PTR_VAL_U64s_MAX) tmp;
			struct bkey_i_btree_ptr *new_key;
retry:
			if (!bch2_bkey_has_device(bkey_i_to_s_c(&b->key),
						  dev_idx)) {
				/*
				 * we might have found a btree node key we
				 * needed to update, and then tried to update it
				 * but got -EINTR after upgrading the iter, but
				 * then raced and the node is now gone:
				 */
				bch2_btree_iter_downgrade(&iter);

				ret = bch2_mark_bkey_replicas(c, bkey_i_to_s_c(&b->key));
				if (ret)
					goto err;
			} else {
				bkey_copy(&tmp.k, &b->key);
				new_key = bkey_i_to_btree_ptr(&tmp.k);

				ret = drop_dev_ptrs(c, bkey_i_to_s(&new_key->k_i),
						    dev_idx, flags, true);
				if (ret)
					goto err;

				ret = bch2_btree_node_update_key(c, &iter, b, new_key);
				if (ret == -EINTR) {
					b = bch2_btree_iter_peek_node(&iter);
					goto retry;
				}
				if (ret)
					goto err;
			}
		}
		bch2_btree_iter_unlock(&iter);
	}

	/* flush relevant btree updates */
	while (1) {
		closure_wait_event(&c->btree_interior_update_wait,
				   !bch2_btree_interior_updates_nr_pending(c) ||
				   c->btree_roots_dirty);
		if (!bch2_btree_interior_updates_nr_pending(c))
			break;
		bch2_journal_meta(&c->journal);
	}

	ret = 0;
out:
	ret = bch2_replicas_gc_end(c, ret);
	mutex_unlock(&c->replicas_gc_lock);

	return ret;
err:
	bch2_btree_iter_unlock(&iter);
	goto out;
}

int bch2_dev_data_drop(struct bch_fs *c, unsigned dev_idx, int flags)
{
	return bch2_dev_usrdata_drop(c, dev_idx, flags) ?:
		bch2_dev_metadata_drop(c, dev_idx, flags);
}