xref: /freebsd/sys/contrib/openzfs/module/zfs/ddt_zap.c (revision a0409676120c1e558d0ade943019934e0f15118d)
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) 2009, 2010, Oracle and/or its affiliates. All rights reserved.
24  * Copyright (c) 2018 by Delphix. All rights reserved.
25  */
26 
27 #include <sys/zfs_context.h>
28 #include <sys/spa.h>
29 #include <sys/zio.h>
30 #include <sys/ddt.h>
31 #include <sys/zap.h>
32 #include <sys/dmu_tx.h>
33 
34 int ddt_zap_leaf_blockshift = 12;
35 int ddt_zap_indirect_blockshift = 12;
36 
37 static int
38 ddt_zap_create(objset_t *os, uint64_t *objectp, dmu_tx_t *tx, boolean_t prehash)
39 {
40 	zap_flags_t flags = ZAP_FLAG_HASH64 | ZAP_FLAG_UINT64_KEY;
41 
42 	if (prehash)
43 		flags |= ZAP_FLAG_PRE_HASHED_KEY;
44 
45 	*objectp = zap_create_flags(os, 0, flags, DMU_OT_DDT_ZAP,
46 	    ddt_zap_leaf_blockshift, ddt_zap_indirect_blockshift,
47 	    DMU_OT_NONE, 0, tx);
48 
49 	return (*objectp == 0 ? SET_ERROR(ENOTSUP) : 0);
50 }
51 
52 static int
53 ddt_zap_destroy(objset_t *os, uint64_t object, dmu_tx_t *tx)
54 {
55 	return (zap_destroy(os, object, tx));
56 }
57 
58 static int
59 ddt_zap_lookup(objset_t *os, uint64_t object, ddt_entry_t *dde)
60 {
61 	uchar_t *cbuf;
62 	uint64_t one, csize;
63 	int error;
64 
65 	cbuf = kmem_alloc(sizeof (dde->dde_phys) + 1, KM_SLEEP);
66 
67 	error = zap_length_uint64(os, object, (uint64_t *)&dde->dde_key,
68 	    DDT_KEY_WORDS, &one, &csize);
69 	if (error)
70 		goto out;
71 
72 	ASSERT(one == 1);
73 	ASSERT(csize <= (sizeof (dde->dde_phys) + 1));
74 
75 	error = zap_lookup_uint64(os, object, (uint64_t *)&dde->dde_key,
76 	    DDT_KEY_WORDS, 1, csize, cbuf);
77 	if (error)
78 		goto out;
79 
80 	ddt_decompress(cbuf, dde->dde_phys, csize, sizeof (dde->dde_phys));
81 out:
82 	kmem_free(cbuf, sizeof (dde->dde_phys) + 1);
83 
84 	return (error);
85 }
86 
87 static void
88 ddt_zap_prefetch(objset_t *os, uint64_t object, ddt_entry_t *dde)
89 {
90 	(void) zap_prefetch_uint64(os, object, (uint64_t *)&dde->dde_key,
91 	    DDT_KEY_WORDS);
92 }
93 
94 static int
95 ddt_zap_update(objset_t *os, uint64_t object, ddt_entry_t *dde, dmu_tx_t *tx)
96 {
97 	uchar_t cbuf[sizeof (dde->dde_phys) + 1];
98 	uint64_t csize;
99 
100 	csize = ddt_compress(dde->dde_phys, cbuf,
101 	    sizeof (dde->dde_phys), sizeof (cbuf));
102 
103 	return (zap_update_uint64(os, object, (uint64_t *)&dde->dde_key,
104 	    DDT_KEY_WORDS, 1, csize, cbuf, tx));
105 }
106 
107 static int
108 ddt_zap_remove(objset_t *os, uint64_t object, ddt_entry_t *dde, dmu_tx_t *tx)
109 {
110 	return (zap_remove_uint64(os, object, (uint64_t *)&dde->dde_key,
111 	    DDT_KEY_WORDS, tx));
112 }
113 
114 static int
115 ddt_zap_walk(objset_t *os, uint64_t object, ddt_entry_t *dde, uint64_t *walk)
116 {
117 	zap_cursor_t zc;
118 	zap_attribute_t za;
119 	int error;
120 
121 	if (*walk == 0) {
122 		/*
123 		 * We don't want to prefetch the entire ZAP object, because
124 		 * it can be enormous.  Also the primary use of DDT iteration
125 		 * is for scrubbing, in which case we will be issuing many
126 		 * scrub I/Os for each ZAP block that we read in, so
127 		 * reading the ZAP is unlikely to be the bottleneck.
128 		 */
129 		zap_cursor_init_noprefetch(&zc, os, object);
130 	} else {
131 		zap_cursor_init_serialized(&zc, os, object, *walk);
132 	}
133 	if ((error = zap_cursor_retrieve(&zc, &za)) == 0) {
134 		uchar_t cbuf[sizeof (dde->dde_phys) + 1];
135 		uint64_t csize = za.za_num_integers;
136 		ASSERT(za.za_integer_length == 1);
137 		error = zap_lookup_uint64(os, object, (uint64_t *)za.za_name,
138 		    DDT_KEY_WORDS, 1, csize, cbuf);
139 		ASSERT(error == 0);
140 		if (error == 0) {
141 			ddt_decompress(cbuf, dde->dde_phys, csize,
142 			    sizeof (dde->dde_phys));
143 			dde->dde_key = *(ddt_key_t *)za.za_name;
144 		}
145 		zap_cursor_advance(&zc);
146 		*walk = zap_cursor_serialize(&zc);
147 	}
148 	zap_cursor_fini(&zc);
149 	return (error);
150 }
151 
152 static int
153 ddt_zap_count(objset_t *os, uint64_t object, uint64_t *count)
154 {
155 	return (zap_count(os, object, count));
156 }
157 
158 const ddt_ops_t ddt_zap_ops = {
159 	"zap",
160 	ddt_zap_create,
161 	ddt_zap_destroy,
162 	ddt_zap_lookup,
163 	ddt_zap_prefetch,
164 	ddt_zap_update,
165 	ddt_zap_remove,
166 	ddt_zap_walk,
167 	ddt_zap_count,
168 };
169