1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22 /*
23 * Copyright (c) 2012 by Delphix. All rights reserved.
24 */
25
26 #include <sys/arc.h>
27 #include <sys/bptree.h>
28 #include <sys/dmu.h>
29 #include <sys/dmu_objset.h>
30 #include <sys/dmu_tx.h>
31 #include <sys/dmu_traverse.h>
32 #include <sys/dsl_dataset.h>
33 #include <sys/dsl_dir.h>
34 #include <sys/dsl_pool.h>
35 #include <sys/dnode.h>
36 #include <sys/refcount.h>
37 #include <sys/spa.h>
38
39 /*
40 * A bptree is a queue of root block pointers from destroyed datasets. When a
41 * dataset is destroyed its root block pointer is put on the end of the pool's
42 * bptree queue so the dataset's blocks can be freed asynchronously by
43 * dsl_scan_sync. This allows the delete operation to finish without traversing
44 * all the dataset's blocks.
45 *
46 * Note that while bt_begin and bt_end are only ever incremented in this code
47 * they are effectively reset to 0 every time the entire bptree is freed because
48 * the bptree's object is destroyed and re-created.
49 */
50
51 struct bptree_args {
52 bptree_phys_t *ba_phys; /* data in bonus buffer, dirtied if freeing */
53 boolean_t ba_free; /* true if freeing during traversal */
54
55 bptree_itor_t *ba_func; /* function to call for each blockpointer */
56 void *ba_arg; /* caller supplied argument to ba_func */
57 dmu_tx_t *ba_tx; /* caller supplied tx, NULL if not freeing */
58 } bptree_args_t;
59
60 uint64_t
61 bptree_alloc(objset_t *os, dmu_tx_t *tx)
62 {
63 uint64_t obj;
64 dmu_buf_t *db;
65 bptree_phys_t *bt;
66
67 obj = dmu_object_alloc(os, DMU_OTN_UINT64_METADATA,
68 SPA_MAXBLOCKSIZE, DMU_OTN_UINT64_METADATA,
69 sizeof (bptree_phys_t), tx);
70
71 /*
72 * Bonus buffer contents are already initialized to 0, but for
73 * readability we make it explicit.
74 */
75 VERIFY0(dmu_bonus_hold(os, obj, FTAG, &db));
76 dmu_buf_will_dirty(db, tx);
77 bt = db->db_data;
78 bt->bt_begin = 0;
79 bt->bt_end = 0;
80 bt->bt_bytes = 0;
81 bt->bt_comp = 0;
82 bt->bt_uncomp = 0;
83 dmu_buf_rele(db, FTAG);
84
85 return (obj);
86 }
87
88 int
89 bptree_free(objset_t *os, uint64_t obj, dmu_tx_t *tx)
90 {
91 dmu_buf_t *db;
92 bptree_phys_t *bt;
93
94 VERIFY0(dmu_bonus_hold(os, obj, FTAG, &db));
95 bt = db->db_data;
96 ASSERT3U(bt->bt_begin, ==, bt->bt_end);
97 ASSERT0(bt->bt_bytes);
98 ASSERT0(bt->bt_comp);
99 ASSERT0(bt->bt_uncomp);
100 dmu_buf_rele(db, FTAG);
101
102 return (dmu_object_free(os, obj, tx));
103 }
104
105 void
106 bptree_add(objset_t *os, uint64_t obj, blkptr_t *bp, uint64_t birth_txg,
107 uint64_t bytes, uint64_t comp, uint64_t uncomp, dmu_tx_t *tx)
108 {
109 dmu_buf_t *db;
110 bptree_phys_t *bt;
111 bptree_entry_phys_t bte;
112
113 /*
114 * bptree objects are in the pool mos, therefore they can only be
115 * modified in syncing context. Furthermore, this is only modified
116 * by the sync thread, so no locking is necessary.
117 */
118 ASSERT(dmu_tx_is_syncing(tx));
119
120 VERIFY0(dmu_bonus_hold(os, obj, FTAG, &db));
121 bt = db->db_data;
122
123 bte.be_birth_txg = birth_txg;
124 bte.be_bp = *bp;
125 bzero(&bte.be_zb, sizeof (bte.be_zb));
126 dmu_write(os, obj, bt->bt_end * sizeof (bte), sizeof (bte), &bte, tx);
127
128 dmu_buf_will_dirty(db, tx);
129 bt->bt_end++;
130 bt->bt_bytes += bytes;
131 bt->bt_comp += comp;
132 bt->bt_uncomp += uncomp;
133 dmu_buf_rele(db, FTAG);
134 }
135
136 /* ARGSUSED */
137 static int
138 bptree_visit_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp, arc_buf_t *pbuf,
139 const zbookmark_t *zb, const dnode_phys_t *dnp, void *arg)
140 {
141 int err;
142 struct bptree_args *ba = arg;
143
144 if (bp == NULL)
145 return (0);
146
147 err = ba->ba_func(ba->ba_arg, bp, ba->ba_tx);
148 if (err == 0 && ba->ba_free) {
149 ba->ba_phys->bt_bytes -= bp_get_dsize_sync(spa, bp);
150 ba->ba_phys->bt_comp -= BP_GET_PSIZE(bp);
151 ba->ba_phys->bt_uncomp -= BP_GET_UCSIZE(bp);
152 }
153 return (err);
154 }
155
156 int
157 bptree_iterate(objset_t *os, uint64_t obj, boolean_t free, bptree_itor_t func,
158 void *arg, dmu_tx_t *tx)
159 {
160 int err;
161 uint64_t i;
162 dmu_buf_t *db;
163 struct bptree_args ba;
164
165 ASSERT(!free || dmu_tx_is_syncing(tx));
166
167 err = dmu_bonus_hold(os, obj, FTAG, &db);
168 if (err != 0)
169 return (err);
170
171 if (free)
172 dmu_buf_will_dirty(db, tx);
173
174 ba.ba_phys = db->db_data;
175 ba.ba_free = free;
176 ba.ba_func = func;
177 ba.ba_arg = arg;
178 ba.ba_tx = tx;
179
180 err = 0;
181 for (i = ba.ba_phys->bt_begin; i < ba.ba_phys->bt_end; i++) {
182 bptree_entry_phys_t bte;
183
184 ASSERT(!free || i == ba.ba_phys->bt_begin);
185
186 err = dmu_read(os, obj, i * sizeof (bte), sizeof (bte),
187 &bte, DMU_READ_NO_PREFETCH);
188 if (err != 0)
189 break;
190
191 err = traverse_dataset_destroyed(os->os_spa, &bte.be_bp,
192 bte.be_birth_txg, &bte.be_zb, TRAVERSE_POST,
193 bptree_visit_cb, &ba);
194 if (free) {
195 ASSERT(err == 0 || err == ERESTART);
196 if (err != 0) {
197 /* save bookmark for future resume */
198 ASSERT3U(bte.be_zb.zb_objset, ==,
199 ZB_DESTROYED_OBJSET);
200 ASSERT0(bte.be_zb.zb_level);
201 dmu_write(os, obj, i * sizeof (bte),
202 sizeof (bte), &bte, tx);
203 break;
204 } else {
205 ba.ba_phys->bt_begin++;
206 (void) dmu_free_range(os, obj,
207 i * sizeof (bte), sizeof (bte), tx);
208 }
209 }
210 }
211
212 ASSERT(!free || err != 0 || ba.ba_phys->bt_begin == ba.ba_phys->bt_end);
213
214 /* if all blocks are free there should be no used space */
215 if (ba.ba_phys->bt_begin == ba.ba_phys->bt_end) {
216 ASSERT0(ba.ba_phys->bt_bytes);
217 ASSERT0(ba.ba_phys->bt_comp);
218 ASSERT0(ba.ba_phys->bt_uncomp);
219 }
220
221 dmu_buf_rele(db, FTAG);
222
223 return (err);
224 }