GNU Linux-libre 6.9-gnu
[releases.git] / fs / bcachefs / migrate.c
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Code for moving data off a device.
4  */
5
6 #include "bcachefs.h"
7 #include "bkey_buf.h"
8 #include "btree_update.h"
9 #include "btree_update_interior.h"
10 #include "buckets.h"
11 #include "errcode.h"
12 #include "extents.h"
13 #include "io_write.h"
14 #include "journal.h"
15 #include "keylist.h"
16 #include "migrate.h"
17 #include "move.h"
18 #include "replicas.h"
19 #include "super-io.h"
20
21 static int drop_dev_ptrs(struct bch_fs *c, struct bkey_s k,
22                          unsigned dev_idx, int flags, bool metadata)
23 {
24         unsigned replicas = metadata ? c->opts.metadata_replicas : c->opts.data_replicas;
25         unsigned lost = metadata ? BCH_FORCE_IF_METADATA_LOST : BCH_FORCE_IF_DATA_LOST;
26         unsigned degraded = metadata ? BCH_FORCE_IF_METADATA_DEGRADED : BCH_FORCE_IF_DATA_DEGRADED;
27         unsigned nr_good;
28
29         bch2_bkey_drop_device(k, dev_idx);
30
31         nr_good = bch2_bkey_durability(c, k.s_c);
32         if ((!nr_good && !(flags & lost)) ||
33             (nr_good < replicas && !(flags & degraded)))
34                 return -BCH_ERR_remove_would_lose_data;
35
36         return 0;
37 }
38
39 static int bch2_dev_usrdata_drop_key(struct btree_trans *trans,
40                                      struct btree_iter *iter,
41                                      struct bkey_s_c k,
42                                      unsigned dev_idx,
43                                      int flags)
44 {
45         struct bch_fs *c = trans->c;
46         struct bkey_i *n;
47         int ret;
48
49         if (!bch2_bkey_has_device_c(k, dev_idx))
50                 return 0;
51
52         n = bch2_bkey_make_mut(trans, iter, &k, BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE);
53         ret = PTR_ERR_OR_ZERO(n);
54         if (ret)
55                 return ret;
56
57         ret = drop_dev_ptrs(c, bkey_i_to_s(n), dev_idx, flags, false);
58         if (ret)
59                 return ret;
60
61         /*
62          * If the new extent no longer has any pointers, bch2_extent_normalize()
63          * will do the appropriate thing with it (turning it into a
64          * KEY_TYPE_error key, or just a discard if it was a cached extent)
65          */
66         bch2_extent_normalize(c, bkey_i_to_s(n));
67
68         /*
69          * Since we're not inserting through an extent iterator
70          * (BTREE_ITER_ALL_SNAPSHOTS iterators aren't extent iterators),
71          * we aren't using the extent overwrite path to delete, we're
72          * just using the normal key deletion path:
73          */
74         if (bkey_deleted(&n->k))
75                 n->k.size = 0;
76         return 0;
77 }
78
79 static int bch2_dev_usrdata_drop(struct bch_fs *c, unsigned dev_idx, int flags)
80 {
81         struct btree_trans *trans = bch2_trans_get(c);
82         enum btree_id id;
83         int ret = 0;
84
85         for (id = 0; id < BTREE_ID_NR; id++) {
86                 if (!btree_type_has_ptrs(id))
87                         continue;
88
89                 ret = for_each_btree_key_commit(trans, iter, id, POS_MIN,
90                                 BTREE_ITER_PREFETCH|BTREE_ITER_ALL_SNAPSHOTS, k,
91                                 NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
92                         bch2_dev_usrdata_drop_key(trans, &iter, k, dev_idx, flags));
93                 if (ret)
94                         break;
95         }
96
97         bch2_trans_put(trans);
98
99         return ret;
100 }
101
102 static int bch2_dev_metadata_drop(struct bch_fs *c, unsigned dev_idx, int flags)
103 {
104         struct btree_trans *trans;
105         struct btree_iter iter;
106         struct closure cl;
107         struct btree *b;
108         struct bkey_buf k;
109         unsigned id;
110         int ret;
111
112         /* don't handle this yet: */
113         if (flags & BCH_FORCE_IF_METADATA_LOST)
114                 return -BCH_ERR_remove_with_metadata_missing_unimplemented;
115
116         trans = bch2_trans_get(c);
117         bch2_bkey_buf_init(&k);
118         closure_init_stack(&cl);
119
120         for (id = 0; id < BTREE_ID_NR; id++) {
121                 bch2_trans_node_iter_init(trans, &iter, id, POS_MIN, 0, 0,
122                                           BTREE_ITER_PREFETCH);
123 retry:
124                 ret = 0;
125                 while (bch2_trans_begin(trans),
126                        (b = bch2_btree_iter_peek_node(&iter)) &&
127                        !(ret = PTR_ERR_OR_ZERO(b))) {
128                         if (!bch2_bkey_has_device_c(bkey_i_to_s_c(&b->key), dev_idx))
129                                 goto next;
130
131                         bch2_bkey_buf_copy(&k, c, &b->key);
132
133                         ret = drop_dev_ptrs(c, bkey_i_to_s(k.k),
134                                             dev_idx, flags, true);
135                         if (ret)
136                                 break;
137
138                         ret = bch2_btree_node_update_key(trans, &iter, b, k.k, 0, false);
139                         if (bch2_err_matches(ret, BCH_ERR_transaction_restart)) {
140                                 ret = 0;
141                                 continue;
142                         }
143
144                         bch_err_msg(c, ret, "updating btree node key");
145                         if (ret)
146                                 break;
147 next:
148                         bch2_btree_iter_next_node(&iter);
149                 }
150                 if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
151                         goto retry;
152
153                 bch2_trans_iter_exit(trans, &iter);
154
155                 if (ret)
156                         goto err;
157         }
158
159         bch2_btree_interior_updates_flush(c);
160         ret = 0;
161 err:
162         bch2_bkey_buf_exit(&k, c);
163         bch2_trans_put(trans);
164
165         BUG_ON(bch2_err_matches(ret, BCH_ERR_transaction_restart));
166
167         return ret;
168 }
169
170 int bch2_dev_data_drop(struct bch_fs *c, unsigned dev_idx, int flags)
171 {
172         return bch2_dev_usrdata_drop(c, dev_idx, flags) ?:
173                 bch2_dev_metadata_drop(c, dev_idx, flags);
174 }