xref: /freebsd/sys/contrib/openzfs/module/zfs/dataset_kstats.c (revision d9a42747950146bf03cda7f6e25d219253f8a57a)
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 https://opensource.org/licenses/CDDL-1.0.
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) 2018 by Delphix. All rights reserved.
24  * Copyright (c) 2018 Datto Inc.
25  */
26 
27 #include <sys/dataset_kstats.h>
28 #include <sys/dmu_objset.h>
29 #include <sys/dsl_dataset.h>
30 #include <sys/spa.h>
31 
32 static dataset_kstat_values_t empty_dataset_kstats = {
33 	{ "dataset_name",	KSTAT_DATA_STRING },
34 	{ "writes",	KSTAT_DATA_UINT64 },
35 	{ "nwritten",	KSTAT_DATA_UINT64 },
36 	{ "reads",	KSTAT_DATA_UINT64 },
37 	{ "nread",	KSTAT_DATA_UINT64 },
38 	{ "nunlinks",	KSTAT_DATA_UINT64 },
39 	{ "nunlinked",	KSTAT_DATA_UINT64 },
40 	{
41 	{ "zil_commit_count",			KSTAT_DATA_UINT64 },
42 	{ "zil_commit_writer_count",		KSTAT_DATA_UINT64 },
43 	{ "zil_itx_count",			KSTAT_DATA_UINT64 },
44 	{ "zil_itx_indirect_count",		KSTAT_DATA_UINT64 },
45 	{ "zil_itx_indirect_bytes",		KSTAT_DATA_UINT64 },
46 	{ "zil_itx_copied_count",		KSTAT_DATA_UINT64 },
47 	{ "zil_itx_copied_bytes",		KSTAT_DATA_UINT64 },
48 	{ "zil_itx_needcopy_count",		KSTAT_DATA_UINT64 },
49 	{ "zil_itx_needcopy_bytes",		KSTAT_DATA_UINT64 },
50 	{ "zil_itx_metaslab_normal_count",	KSTAT_DATA_UINT64 },
51 	{ "zil_itx_metaslab_normal_bytes",	KSTAT_DATA_UINT64 },
52 	{ "zil_itx_metaslab_slog_count",	KSTAT_DATA_UINT64 },
53 	{ "zil_itx_metaslab_slog_bytes",	KSTAT_DATA_UINT64 }
54 	}
55 };
56 
57 static int
58 dataset_kstats_update(kstat_t *ksp, int rw)
59 {
60 	dataset_kstats_t *dk = ksp->ks_private;
61 	dataset_kstat_values_t *dkv = ksp->ks_data;
62 	ASSERT3P(dk->dk_kstats->ks_data, ==, dkv);
63 
64 	if (rw == KSTAT_WRITE)
65 		return (EACCES);
66 
67 	dkv->dkv_writes.value.ui64 =
68 	    wmsum_value(&dk->dk_sums.dss_writes);
69 	dkv->dkv_nwritten.value.ui64 =
70 	    wmsum_value(&dk->dk_sums.dss_nwritten);
71 	dkv->dkv_reads.value.ui64 =
72 	    wmsum_value(&dk->dk_sums.dss_reads);
73 	dkv->dkv_nread.value.ui64 =
74 	    wmsum_value(&dk->dk_sums.dss_nread);
75 	dkv->dkv_nunlinks.value.ui64 =
76 	    wmsum_value(&dk->dk_sums.dss_nunlinks);
77 	dkv->dkv_nunlinked.value.ui64 =
78 	    wmsum_value(&dk->dk_sums.dss_nunlinked);
79 
80 	zil_kstat_values_update(&dkv->dkv_zil_stats, &dk->dk_zil_sums);
81 
82 	return (0);
83 }
84 
85 int
86 dataset_kstats_create(dataset_kstats_t *dk, objset_t *objset)
87 {
88 	/*
89 	 * There should not be anything wrong with having kstats for
90 	 * snapshots. Since we are not sure how useful they would be
91 	 * though nor how much their memory overhead would matter in
92 	 * a filesystem with many snapshots, we skip them for now.
93 	 */
94 	if (dmu_objset_is_snapshot(objset))
95 		return (0);
96 
97 	/*
98 	 * At the time of this writing, KSTAT_STRLEN is 255 in Linux,
99 	 * and the spa_name can theoretically be up to 256 characters.
100 	 * In reality though the spa_name can be 240 characters max
101 	 * [see origin directory name check in pool_namecheck()]. Thus,
102 	 * the naming scheme for the module name below should not cause
103 	 * any truncations. In the event that a truncation does happen
104 	 * though, due to some future change, we silently skip creating
105 	 * the kstat and log the event.
106 	 */
107 	char kstat_module_name[KSTAT_STRLEN];
108 	int n = snprintf(kstat_module_name, sizeof (kstat_module_name),
109 	    "zfs/%s", spa_name(dmu_objset_spa(objset)));
110 	if (n < 0) {
111 		zfs_dbgmsg("failed to create dataset kstat for objset %lld: "
112 		    " snprintf() for kstat module name returned %d",
113 		    (unsigned long long)dmu_objset_id(objset), n);
114 		return (SET_ERROR(EINVAL));
115 	} else if (n >= KSTAT_STRLEN) {
116 		zfs_dbgmsg("failed to create dataset kstat for objset %lld: "
117 		    "kstat module name length (%d) exceeds limit (%d)",
118 		    (unsigned long long)dmu_objset_id(objset),
119 		    n, KSTAT_STRLEN);
120 		return (SET_ERROR(ENAMETOOLONG));
121 	}
122 
123 	char kstat_name[KSTAT_STRLEN];
124 	n = snprintf(kstat_name, sizeof (kstat_name), "objset-0x%llx",
125 	    (unsigned long long)dmu_objset_id(objset));
126 	if (n < 0) {
127 		zfs_dbgmsg("failed to create dataset kstat for objset %lld: "
128 		    " snprintf() for kstat name returned %d",
129 		    (unsigned long long)dmu_objset_id(objset), n);
130 		return (SET_ERROR(EINVAL));
131 	} else if (n >= KSTAT_STRLEN) {
132 		zfs_dbgmsg("failed to create dataset kstat for objset %lld: "
133 		    "kstat name length (%d) exceeds limit (%d)",
134 		    (unsigned long long)dmu_objset_id(objset),
135 		    n, KSTAT_STRLEN);
136 		return (SET_ERROR(ENAMETOOLONG));
137 	}
138 
139 	kstat_t *kstat = kstat_create(kstat_module_name, 0, kstat_name,
140 	    "dataset", KSTAT_TYPE_NAMED,
141 	    sizeof (empty_dataset_kstats) / sizeof (kstat_named_t),
142 	    KSTAT_FLAG_VIRTUAL);
143 	if (kstat == NULL)
144 		return (SET_ERROR(ENOMEM));
145 
146 	dataset_kstat_values_t *dk_kstats =
147 	    kmem_alloc(sizeof (empty_dataset_kstats), KM_SLEEP);
148 	memcpy(dk_kstats, &empty_dataset_kstats,
149 	    sizeof (empty_dataset_kstats));
150 
151 	char *ds_name = kmem_zalloc(ZFS_MAX_DATASET_NAME_LEN, KM_SLEEP);
152 	dsl_dataset_name(objset->os_dsl_dataset, ds_name);
153 	KSTAT_NAMED_STR_PTR(&dk_kstats->dkv_ds_name) = ds_name;
154 	KSTAT_NAMED_STR_BUFLEN(&dk_kstats->dkv_ds_name) =
155 	    ZFS_MAX_DATASET_NAME_LEN;
156 
157 	kstat->ks_data = dk_kstats;
158 	kstat->ks_update = dataset_kstats_update;
159 	kstat->ks_private = dk;
160 	kstat->ks_data_size += ZFS_MAX_DATASET_NAME_LEN;
161 
162 	wmsum_init(&dk->dk_sums.dss_writes, 0);
163 	wmsum_init(&dk->dk_sums.dss_nwritten, 0);
164 	wmsum_init(&dk->dk_sums.dss_reads, 0);
165 	wmsum_init(&dk->dk_sums.dss_nread, 0);
166 	wmsum_init(&dk->dk_sums.dss_nunlinks, 0);
167 	wmsum_init(&dk->dk_sums.dss_nunlinked, 0);
168 	zil_sums_init(&dk->dk_zil_sums);
169 
170 	dk->dk_kstats = kstat;
171 	kstat_install(kstat);
172 	return (0);
173 }
174 
175 void
176 dataset_kstats_destroy(dataset_kstats_t *dk)
177 {
178 	if (dk->dk_kstats == NULL)
179 		return;
180 
181 	dataset_kstat_values_t *dkv = dk->dk_kstats->ks_data;
182 	kstat_delete(dk->dk_kstats);
183 	dk->dk_kstats = NULL;
184 	kmem_free(KSTAT_NAMED_STR_PTR(&dkv->dkv_ds_name),
185 	    KSTAT_NAMED_STR_BUFLEN(&dkv->dkv_ds_name));
186 	kmem_free(dkv, sizeof (empty_dataset_kstats));
187 
188 	wmsum_fini(&dk->dk_sums.dss_writes);
189 	wmsum_fini(&dk->dk_sums.dss_nwritten);
190 	wmsum_fini(&dk->dk_sums.dss_reads);
191 	wmsum_fini(&dk->dk_sums.dss_nread);
192 	wmsum_fini(&dk->dk_sums.dss_nunlinks);
193 	wmsum_fini(&dk->dk_sums.dss_nunlinked);
194 	zil_sums_fini(&dk->dk_zil_sums);
195 }
196 
197 void
198 dataset_kstats_update_write_kstats(dataset_kstats_t *dk,
199     int64_t nwritten)
200 {
201 	ASSERT3S(nwritten, >=, 0);
202 
203 	if (dk->dk_kstats == NULL)
204 		return;
205 
206 	wmsum_add(&dk->dk_sums.dss_writes, 1);
207 	wmsum_add(&dk->dk_sums.dss_nwritten, nwritten);
208 }
209 
210 void
211 dataset_kstats_update_read_kstats(dataset_kstats_t *dk,
212     int64_t nread)
213 {
214 	ASSERT3S(nread, >=, 0);
215 
216 	if (dk->dk_kstats == NULL)
217 		return;
218 
219 	wmsum_add(&dk->dk_sums.dss_reads, 1);
220 	wmsum_add(&dk->dk_sums.dss_nread, nread);
221 }
222 
223 void
224 dataset_kstats_update_nunlinks_kstat(dataset_kstats_t *dk, int64_t delta)
225 {
226 	if (dk->dk_kstats == NULL)
227 		return;
228 
229 	wmsum_add(&dk->dk_sums.dss_nunlinks, delta);
230 }
231 
232 void
233 dataset_kstats_update_nunlinked_kstat(dataset_kstats_t *dk, int64_t delta)
234 {
235 	if (dk->dk_kstats == NULL)
236 		return;
237 
238 	wmsum_add(&dk->dk_sums.dss_nunlinked, delta);
239 }
240