xref: /freebsd/sys/contrib/openzfs/module/zfs/dataset_kstats.c (revision 61145dc2b94f12f6a47344fb9aac702321880e43)
1 // SPDX-License-Identifier: CDDL-1.0
2 /*
3  * CDDL HEADER START
4  *
5  * The contents of this file are subject to the terms of the
6  * Common Development and Distribution License (the "License").
7  * You may not use this file except in compliance with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or https://opensource.org/licenses/CDDL-1.0.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 
23 /*
24  * Copyright (c) 2018 by Delphix. All rights reserved.
25  * Copyright (c) 2018 Datto Inc.
26  */
27 
28 #include <sys/dataset_kstats.h>
29 #include <sys/dmu_objset.h>
30 #include <sys/dsl_dataset.h>
31 #include <sys/spa.h>
32 
33 static dataset_kstat_values_t empty_dataset_kstats = {
34 	{ "dataset_name",	KSTAT_DATA_STRING },
35 	{ "writes",	KSTAT_DATA_UINT64 },
36 	{ "nwritten",	KSTAT_DATA_UINT64 },
37 	{ "reads",	KSTAT_DATA_UINT64 },
38 	{ "nread",	KSTAT_DATA_UINT64 },
39 	{ "nunlinks",	KSTAT_DATA_UINT64 },
40 	{ "nunlinked",	KSTAT_DATA_UINT64 },
41 	{
42 	{ "zil_commit_count",			KSTAT_DATA_UINT64 },
43 	{ "zil_commit_writer_count",		KSTAT_DATA_UINT64 },
44 	{ "zil_commit_error_count",		KSTAT_DATA_UINT64 },
45 	{ "zil_commit_stall_count",		KSTAT_DATA_UINT64 },
46 	{ "zil_commit_suspend_count",		KSTAT_DATA_UINT64 },
47 	{ "zil_itx_count",			KSTAT_DATA_UINT64 },
48 	{ "zil_itx_indirect_count",		KSTAT_DATA_UINT64 },
49 	{ "zil_itx_indirect_bytes",		KSTAT_DATA_UINT64 },
50 	{ "zil_itx_copied_count",		KSTAT_DATA_UINT64 },
51 	{ "zil_itx_copied_bytes",		KSTAT_DATA_UINT64 },
52 	{ "zil_itx_needcopy_count",		KSTAT_DATA_UINT64 },
53 	{ "zil_itx_needcopy_bytes",		KSTAT_DATA_UINT64 },
54 	{ "zil_itx_metaslab_normal_count",	KSTAT_DATA_UINT64 },
55 	{ "zil_itx_metaslab_normal_bytes",	KSTAT_DATA_UINT64 },
56 	{ "zil_itx_metaslab_normal_write",	KSTAT_DATA_UINT64 },
57 	{ "zil_itx_metaslab_normal_alloc",	KSTAT_DATA_UINT64 },
58 	{ "zil_itx_metaslab_slog_count",	KSTAT_DATA_UINT64 },
59 	{ "zil_itx_metaslab_slog_bytes",	KSTAT_DATA_UINT64 },
60 	{ "zil_itx_metaslab_slog_write",	KSTAT_DATA_UINT64 },
61 	{ "zil_itx_metaslab_slog_alloc",	KSTAT_DATA_UINT64 }
62 	}
63 };
64 
65 static int
dataset_kstats_update(kstat_t * ksp,int rw)66 dataset_kstats_update(kstat_t *ksp, int rw)
67 {
68 	dataset_kstats_t *dk = ksp->ks_private;
69 	dataset_kstat_values_t *dkv = ksp->ks_data;
70 	ASSERT3P(dk->dk_kstats->ks_data, ==, dkv);
71 
72 	if (rw == KSTAT_WRITE)
73 		return (EACCES);
74 
75 	dkv->dkv_writes.value.ui64 =
76 	    wmsum_value(&dk->dk_sums.dss_writes);
77 	dkv->dkv_nwritten.value.ui64 =
78 	    wmsum_value(&dk->dk_sums.dss_nwritten);
79 	dkv->dkv_reads.value.ui64 =
80 	    wmsum_value(&dk->dk_sums.dss_reads);
81 	dkv->dkv_nread.value.ui64 =
82 	    wmsum_value(&dk->dk_sums.dss_nread);
83 	dkv->dkv_nunlinks.value.ui64 =
84 	    wmsum_value(&dk->dk_sums.dss_nunlinks);
85 	dkv->dkv_nunlinked.value.ui64 =
86 	    wmsum_value(&dk->dk_sums.dss_nunlinked);
87 
88 	zil_kstat_values_update(&dkv->dkv_zil_stats, &dk->dk_zil_sums);
89 
90 	return (0);
91 }
92 
93 int
dataset_kstats_create(dataset_kstats_t * dk,objset_t * objset)94 dataset_kstats_create(dataset_kstats_t *dk, objset_t *objset)
95 {
96 	/*
97 	 * There should not be anything wrong with having kstats for
98 	 * snapshots. Since we are not sure how useful they would be
99 	 * though nor how much their memory overhead would matter in
100 	 * a filesystem with many snapshots, we skip them for now.
101 	 */
102 	if (dmu_objset_is_snapshot(objset))
103 		return (0);
104 
105 	/*
106 	 * At the time of this writing, KSTAT_STRLEN is 255 in Linux,
107 	 * and the spa_name can theoretically be up to 256 characters.
108 	 * In reality though the spa_name can be 240 characters max
109 	 * [see origin directory name check in pool_namecheck()]. Thus,
110 	 * the naming scheme for the module name below should not cause
111 	 * any truncations. In the event that a truncation does happen
112 	 * though, due to some future change, we silently skip creating
113 	 * the kstat and log the event.
114 	 */
115 	char kstat_module_name[KSTAT_STRLEN];
116 	int n = snprintf(kstat_module_name, sizeof (kstat_module_name),
117 	    "zfs/%s", spa_name(dmu_objset_spa(objset)));
118 	if (n < 0) {
119 		zfs_dbgmsg("failed to create dataset kstat for objset %lld: "
120 		    " snprintf() for kstat module name returned %d",
121 		    (unsigned long long)dmu_objset_id(objset), n);
122 		return (SET_ERROR(EINVAL));
123 	} else if (n >= KSTAT_STRLEN) {
124 		zfs_dbgmsg("failed to create dataset kstat for objset %lld: "
125 		    "kstat module name length (%d) exceeds limit (%d)",
126 		    (unsigned long long)dmu_objset_id(objset),
127 		    n, KSTAT_STRLEN);
128 		return (SET_ERROR(ENAMETOOLONG));
129 	}
130 
131 	char kstat_name[KSTAT_STRLEN];
132 	n = snprintf(kstat_name, sizeof (kstat_name), "objset-0x%llx",
133 	    (unsigned long long)dmu_objset_id(objset));
134 	if (n < 0) {
135 		zfs_dbgmsg("failed to create dataset kstat for objset %lld: "
136 		    " snprintf() for kstat name returned %d",
137 		    (unsigned long long)dmu_objset_id(objset), n);
138 		return (SET_ERROR(EINVAL));
139 	} else if (n >= KSTAT_STRLEN) {
140 		zfs_dbgmsg("failed to create dataset kstat for objset %lld: "
141 		    "kstat name length (%d) exceeds limit (%d)",
142 		    (unsigned long long)dmu_objset_id(objset),
143 		    n, KSTAT_STRLEN);
144 		return (SET_ERROR(ENAMETOOLONG));
145 	}
146 
147 	kstat_t *kstat = kstat_create(kstat_module_name, 0, kstat_name,
148 	    "dataset", KSTAT_TYPE_NAMED,
149 	    sizeof (empty_dataset_kstats) / sizeof (kstat_named_t),
150 	    KSTAT_FLAG_VIRTUAL);
151 	if (kstat == NULL)
152 		return (SET_ERROR(ENOMEM));
153 
154 	dataset_kstat_values_t *dk_kstats =
155 	    kmem_alloc(sizeof (empty_dataset_kstats), KM_SLEEP);
156 	memcpy(dk_kstats, &empty_dataset_kstats,
157 	    sizeof (empty_dataset_kstats));
158 
159 	char *ds_name = kmem_zalloc(ZFS_MAX_DATASET_NAME_LEN, KM_SLEEP);
160 	dsl_dataset_name(objset->os_dsl_dataset, ds_name);
161 	KSTAT_NAMED_STR_PTR(&dk_kstats->dkv_ds_name) = ds_name;
162 	KSTAT_NAMED_STR_BUFLEN(&dk_kstats->dkv_ds_name) =
163 	    ZFS_MAX_DATASET_NAME_LEN;
164 
165 	kstat->ks_data = dk_kstats;
166 	kstat->ks_update = dataset_kstats_update;
167 	kstat->ks_private = dk;
168 	kstat->ks_data_size += ZFS_MAX_DATASET_NAME_LEN;
169 
170 	wmsum_init(&dk->dk_sums.dss_writes, 0);
171 	wmsum_init(&dk->dk_sums.dss_nwritten, 0);
172 	wmsum_init(&dk->dk_sums.dss_reads, 0);
173 	wmsum_init(&dk->dk_sums.dss_nread, 0);
174 	wmsum_init(&dk->dk_sums.dss_nunlinks, 0);
175 	wmsum_init(&dk->dk_sums.dss_nunlinked, 0);
176 	zil_sums_init(&dk->dk_zil_sums);
177 
178 	dk->dk_kstats = kstat;
179 	kstat_install(kstat);
180 	return (0);
181 }
182 
183 void
dataset_kstats_destroy(dataset_kstats_t * dk)184 dataset_kstats_destroy(dataset_kstats_t *dk)
185 {
186 	if (dk->dk_kstats == NULL)
187 		return;
188 
189 	dataset_kstat_values_t *dkv = dk->dk_kstats->ks_data;
190 	kstat_delete(dk->dk_kstats);
191 	dk->dk_kstats = NULL;
192 	kmem_free(KSTAT_NAMED_STR_PTR(&dkv->dkv_ds_name),
193 	    KSTAT_NAMED_STR_BUFLEN(&dkv->dkv_ds_name));
194 	kmem_free(dkv, sizeof (empty_dataset_kstats));
195 
196 	wmsum_fini(&dk->dk_sums.dss_writes);
197 	wmsum_fini(&dk->dk_sums.dss_nwritten);
198 	wmsum_fini(&dk->dk_sums.dss_reads);
199 	wmsum_fini(&dk->dk_sums.dss_nread);
200 	wmsum_fini(&dk->dk_sums.dss_nunlinks);
201 	wmsum_fini(&dk->dk_sums.dss_nunlinked);
202 	zil_sums_fini(&dk->dk_zil_sums);
203 }
204 
205 void
dataset_kstats_rename(dataset_kstats_t * dk,const char * name)206 dataset_kstats_rename(dataset_kstats_t *dk, const char *name)
207 {
208 	if (dk->dk_kstats == NULL)
209 		return;
210 
211 	dataset_kstat_values_t *dkv = dk->dk_kstats->ks_data;
212 	char *ds_name;
213 
214 	ds_name = KSTAT_NAMED_STR_PTR(&dkv->dkv_ds_name);
215 	ASSERT3S(ds_name, !=, NULL);
216 	(void) strlcpy(ds_name, name,
217 	    KSTAT_NAMED_STR_BUFLEN(&dkv->dkv_ds_name));
218 }
219 
220 void
dataset_kstats_update_write_kstats(dataset_kstats_t * dk,int64_t nwritten)221 dataset_kstats_update_write_kstats(dataset_kstats_t *dk, int64_t nwritten)
222 {
223 	ASSERT3S(nwritten, >=, 0);
224 
225 	if (dk->dk_kstats == NULL)
226 		return;
227 
228 	wmsum_add(&dk->dk_sums.dss_writes, 1);
229 	wmsum_add(&dk->dk_sums.dss_nwritten, nwritten);
230 }
231 
232 void
dataset_kstats_update_read_kstats(dataset_kstats_t * dk,int64_t nread)233 dataset_kstats_update_read_kstats(dataset_kstats_t *dk, int64_t nread)
234 {
235 	ASSERT3S(nread, >=, 0);
236 
237 	if (dk->dk_kstats == NULL)
238 		return;
239 
240 	wmsum_add(&dk->dk_sums.dss_reads, 1);
241 	wmsum_add(&dk->dk_sums.dss_nread, nread);
242 }
243 
244 void
dataset_kstats_update_nunlinks_kstat(dataset_kstats_t * dk,int64_t delta)245 dataset_kstats_update_nunlinks_kstat(dataset_kstats_t *dk, int64_t delta)
246 {
247 	if (dk->dk_kstats == NULL)
248 		return;
249 
250 	wmsum_add(&dk->dk_sums.dss_nunlinks, delta);
251 }
252 
253 void
dataset_kstats_update_nunlinked_kstat(dataset_kstats_t * dk,int64_t delta)254 dataset_kstats_update_nunlinked_kstat(dataset_kstats_t *dk, int64_t delta)
255 {
256 	if (dk->dk_kstats == NULL)
257 		return;
258 
259 	wmsum_add(&dk->dk_sums.dss_nunlinked, delta);
260 }
261