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 "progress.h"
19 #include "replicas.h"
20 #include "super-io.h"
21 
drop_dev_ptrs(struct bch_fs * c,struct bkey_s k,unsigned dev_idx,int flags,bool metadata)22 static int drop_dev_ptrs(struct bch_fs *c, struct bkey_s k,
23 			 unsigned dev_idx, int flags, bool metadata)
24 {
25 	unsigned replicas = metadata ? c->opts.metadata_replicas : c->opts.data_replicas;
26 	unsigned lost = metadata ? BCH_FORCE_IF_METADATA_LOST : BCH_FORCE_IF_DATA_LOST;
27 	unsigned degraded = metadata ? BCH_FORCE_IF_METADATA_DEGRADED : BCH_FORCE_IF_DATA_DEGRADED;
28 	unsigned nr_good;
29 
30 	bch2_bkey_drop_device(k, dev_idx);
31 
32 	nr_good = bch2_bkey_durability(c, k.s_c);
33 	if ((!nr_good && !(flags & lost)) ||
34 	    (nr_good < replicas && !(flags & degraded)))
35 		return -BCH_ERR_remove_would_lose_data;
36 
37 	return 0;
38 }
39 
bch2_dev_usrdata_drop_key(struct btree_trans * trans,struct btree_iter * iter,struct bkey_s_c k,unsigned dev_idx,int flags)40 static int bch2_dev_usrdata_drop_key(struct btree_trans *trans,
41 				     struct btree_iter *iter,
42 				     struct bkey_s_c k,
43 				     unsigned dev_idx,
44 				     int flags)
45 {
46 	struct bch_fs *c = trans->c;
47 	struct bkey_i *n;
48 	int ret;
49 
50 	if (!bch2_bkey_has_device_c(k, dev_idx))
51 		return 0;
52 
53 	n = bch2_bkey_make_mut(trans, iter, &k, BTREE_UPDATE_internal_snapshot_node);
54 	ret = PTR_ERR_OR_ZERO(n);
55 	if (ret)
56 		return ret;
57 
58 	ret = drop_dev_ptrs(c, bkey_i_to_s(n), dev_idx, flags, false);
59 	if (ret)
60 		return ret;
61 
62 	/*
63 	 * If the new extent no longer has any pointers, bch2_extent_normalize()
64 	 * will do the appropriate thing with it (turning it into a
65 	 * KEY_TYPE_error key, or just a discard if it was a cached extent)
66 	 */
67 	bch2_extent_normalize(c, bkey_i_to_s(n));
68 
69 	/*
70 	 * Since we're not inserting through an extent iterator
71 	 * (BTREE_ITER_all_snapshots iterators aren't extent iterators),
72 	 * we aren't using the extent overwrite path to delete, we're
73 	 * just using the normal key deletion path:
74 	 */
75 	if (bkey_deleted(&n->k))
76 		n->k.size = 0;
77 	return 0;
78 }
79 
bch2_dev_usrdata_drop(struct bch_fs * c,struct progress_indicator_state * progress,unsigned dev_idx,int flags)80 static int bch2_dev_usrdata_drop(struct bch_fs *c,
81 				 struct progress_indicator_state *progress,
82 				 unsigned dev_idx, int flags)
83 {
84 	struct btree_trans *trans = bch2_trans_get(c);
85 	enum btree_id id;
86 	int ret = 0;
87 
88 	for (id = 0; id < BTREE_ID_NR; id++) {
89 		if (!btree_type_has_ptrs(id))
90 			continue;
91 
92 		ret = for_each_btree_key_commit(trans, iter, id, POS_MIN,
93 				BTREE_ITER_prefetch|BTREE_ITER_all_snapshots, k,
94 				NULL, NULL, BCH_TRANS_COMMIT_no_enospc, ({
95 			bch2_progress_update_iter(trans, progress, &iter, "dropping user data");
96 			bch2_dev_usrdata_drop_key(trans, &iter, k, dev_idx, flags);
97 		}));
98 		if (ret)
99 			break;
100 	}
101 
102 	bch2_trans_put(trans);
103 
104 	return ret;
105 }
106 
bch2_dev_metadata_drop(struct bch_fs * c,struct progress_indicator_state * progress,unsigned dev_idx,int flags)107 static int bch2_dev_metadata_drop(struct bch_fs *c,
108 				  struct progress_indicator_state *progress,
109 				  unsigned dev_idx, int flags)
110 {
111 	struct btree_trans *trans;
112 	struct btree_iter iter;
113 	struct closure cl;
114 	struct btree *b;
115 	struct bkey_buf k;
116 	unsigned id;
117 	int ret;
118 
119 	/* don't handle this yet: */
120 	if (flags & BCH_FORCE_IF_METADATA_LOST)
121 		return -BCH_ERR_remove_with_metadata_missing_unimplemented;
122 
123 	trans = bch2_trans_get(c);
124 	bch2_bkey_buf_init(&k);
125 	closure_init_stack(&cl);
126 
127 	for (id = 0; id < BTREE_ID_NR; id++) {
128 		bch2_trans_node_iter_init(trans, &iter, id, POS_MIN, 0, 0,
129 					  BTREE_ITER_prefetch);
130 retry:
131 		ret = 0;
132 		while (bch2_trans_begin(trans),
133 		       (b = bch2_btree_iter_peek_node(trans, &iter)) &&
134 		       !(ret = PTR_ERR_OR_ZERO(b))) {
135 			bch2_progress_update_iter(trans, progress, &iter, "dropping metadata");
136 
137 			if (!bch2_bkey_has_device_c(bkey_i_to_s_c(&b->key), dev_idx))
138 				goto next;
139 
140 			bch2_bkey_buf_copy(&k, c, &b->key);
141 
142 			ret = drop_dev_ptrs(c, bkey_i_to_s(k.k),
143 					    dev_idx, flags, true);
144 			if (ret)
145 				break;
146 
147 			ret = bch2_btree_node_update_key(trans, &iter, b, k.k, 0, false);
148 			if (bch2_err_matches(ret, BCH_ERR_transaction_restart)) {
149 				ret = 0;
150 				continue;
151 			}
152 
153 			bch_err_msg(c, ret, "updating btree node key");
154 			if (ret)
155 				break;
156 next:
157 			bch2_btree_iter_next_node(trans, &iter);
158 		}
159 		if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
160 			goto retry;
161 
162 		bch2_trans_iter_exit(trans, &iter);
163 
164 		if (ret)
165 			goto err;
166 	}
167 
168 	bch2_btree_interior_updates_flush(c);
169 	ret = 0;
170 err:
171 	bch2_bkey_buf_exit(&k, c);
172 	bch2_trans_put(trans);
173 
174 	BUG_ON(bch2_err_matches(ret, BCH_ERR_transaction_restart));
175 
176 	return ret;
177 }
178 
bch2_dev_data_drop(struct bch_fs * c,unsigned dev_idx,int flags)179 int bch2_dev_data_drop(struct bch_fs *c, unsigned dev_idx, int flags)
180 {
181 	struct progress_indicator_state progress;
182 	bch2_progress_init(&progress, c,
183 			   BIT_ULL(BTREE_ID_extents)|
184 			   BIT_ULL(BTREE_ID_reflink));
185 
186 	return bch2_dev_usrdata_drop(c, &progress, dev_idx, flags) ?:
187 		bch2_dev_metadata_drop(c, &progress, dev_idx, flags);
188 }
189