xref: /freebsd/sys/contrib/openzfs/module/zfs/dataset_kstats.c (revision 7a7741af18d6c8a804cc643cb7ecda9d730c6aa6)
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_commit_error_count",		KSTAT_DATA_UINT64 },
44 	{ "zil_commit_stall_count",		KSTAT_DATA_UINT64 },
45 	{ "zil_commit_suspend_count",		KSTAT_DATA_UINT64 },
46 	{ "zil_itx_count",			KSTAT_DATA_UINT64 },
47 	{ "zil_itx_indirect_count",		KSTAT_DATA_UINT64 },
48 	{ "zil_itx_indirect_bytes",		KSTAT_DATA_UINT64 },
49 	{ "zil_itx_copied_count",		KSTAT_DATA_UINT64 },
50 	{ "zil_itx_copied_bytes",		KSTAT_DATA_UINT64 },
51 	{ "zil_itx_needcopy_count",		KSTAT_DATA_UINT64 },
52 	{ "zil_itx_needcopy_bytes",		KSTAT_DATA_UINT64 },
53 	{ "zil_itx_metaslab_normal_count",	KSTAT_DATA_UINT64 },
54 	{ "zil_itx_metaslab_normal_bytes",	KSTAT_DATA_UINT64 },
55 	{ "zil_itx_metaslab_normal_write",	KSTAT_DATA_UINT64 },
56 	{ "zil_itx_metaslab_normal_alloc",	KSTAT_DATA_UINT64 },
57 	{ "zil_itx_metaslab_slog_count",	KSTAT_DATA_UINT64 },
58 	{ "zil_itx_metaslab_slog_bytes",	KSTAT_DATA_UINT64 },
59 	{ "zil_itx_metaslab_slog_write",	KSTAT_DATA_UINT64 },
60 	{ "zil_itx_metaslab_slog_alloc",	KSTAT_DATA_UINT64 }
61 	}
62 };
63 
64 static int
dataset_kstats_update(kstat_t * ksp,int rw)65 dataset_kstats_update(kstat_t *ksp, int rw)
66 {
67 	dataset_kstats_t *dk = ksp->ks_private;
68 	dataset_kstat_values_t *dkv = ksp->ks_data;
69 	ASSERT3P(dk->dk_kstats->ks_data, ==, dkv);
70 
71 	if (rw == KSTAT_WRITE)
72 		return (EACCES);
73 
74 	dkv->dkv_writes.value.ui64 =
75 	    wmsum_value(&dk->dk_sums.dss_writes);
76 	dkv->dkv_nwritten.value.ui64 =
77 	    wmsum_value(&dk->dk_sums.dss_nwritten);
78 	dkv->dkv_reads.value.ui64 =
79 	    wmsum_value(&dk->dk_sums.dss_reads);
80 	dkv->dkv_nread.value.ui64 =
81 	    wmsum_value(&dk->dk_sums.dss_nread);
82 	dkv->dkv_nunlinks.value.ui64 =
83 	    wmsum_value(&dk->dk_sums.dss_nunlinks);
84 	dkv->dkv_nunlinked.value.ui64 =
85 	    wmsum_value(&dk->dk_sums.dss_nunlinked);
86 
87 	zil_kstat_values_update(&dkv->dkv_zil_stats, &dk->dk_zil_sums);
88 
89 	return (0);
90 }
91 
92 int
dataset_kstats_create(dataset_kstats_t * dk,objset_t * objset)93 dataset_kstats_create(dataset_kstats_t *dk, objset_t *objset)
94 {
95 	/*
96 	 * There should not be anything wrong with having kstats for
97 	 * snapshots. Since we are not sure how useful they would be
98 	 * though nor how much their memory overhead would matter in
99 	 * a filesystem with many snapshots, we skip them for now.
100 	 */
101 	if (dmu_objset_is_snapshot(objset))
102 		return (0);
103 
104 	/*
105 	 * At the time of this writing, KSTAT_STRLEN is 255 in Linux,
106 	 * and the spa_name can theoretically be up to 256 characters.
107 	 * In reality though the spa_name can be 240 characters max
108 	 * [see origin directory name check in pool_namecheck()]. Thus,
109 	 * the naming scheme for the module name below should not cause
110 	 * any truncations. In the event that a truncation does happen
111 	 * though, due to some future change, we silently skip creating
112 	 * the kstat and log the event.
113 	 */
114 	char kstat_module_name[KSTAT_STRLEN];
115 	int n = snprintf(kstat_module_name, sizeof (kstat_module_name),
116 	    "zfs/%s", spa_name(dmu_objset_spa(objset)));
117 	if (n < 0) {
118 		zfs_dbgmsg("failed to create dataset kstat for objset %lld: "
119 		    " snprintf() for kstat module name returned %d",
120 		    (unsigned long long)dmu_objset_id(objset), n);
121 		return (SET_ERROR(EINVAL));
122 	} else if (n >= KSTAT_STRLEN) {
123 		zfs_dbgmsg("failed to create dataset kstat for objset %lld: "
124 		    "kstat module name length (%d) exceeds limit (%d)",
125 		    (unsigned long long)dmu_objset_id(objset),
126 		    n, KSTAT_STRLEN);
127 		return (SET_ERROR(ENAMETOOLONG));
128 	}
129 
130 	char kstat_name[KSTAT_STRLEN];
131 	n = snprintf(kstat_name, sizeof (kstat_name), "objset-0x%llx",
132 	    (unsigned long long)dmu_objset_id(objset));
133 	if (n < 0) {
134 		zfs_dbgmsg("failed to create dataset kstat for objset %lld: "
135 		    " snprintf() for kstat name returned %d",
136 		    (unsigned long long)dmu_objset_id(objset), n);
137 		return (SET_ERROR(EINVAL));
138 	} else if (n >= KSTAT_STRLEN) {
139 		zfs_dbgmsg("failed to create dataset kstat for objset %lld: "
140 		    "kstat name length (%d) exceeds limit (%d)",
141 		    (unsigned long long)dmu_objset_id(objset),
142 		    n, KSTAT_STRLEN);
143 		return (SET_ERROR(ENAMETOOLONG));
144 	}
145 
146 	kstat_t *kstat = kstat_create(kstat_module_name, 0, kstat_name,
147 	    "dataset", KSTAT_TYPE_NAMED,
148 	    sizeof (empty_dataset_kstats) / sizeof (kstat_named_t),
149 	    KSTAT_FLAG_VIRTUAL);
150 	if (kstat == NULL)
151 		return (SET_ERROR(ENOMEM));
152 
153 	dataset_kstat_values_t *dk_kstats =
154 	    kmem_alloc(sizeof (empty_dataset_kstats), KM_SLEEP);
155 	memcpy(dk_kstats, &empty_dataset_kstats,
156 	    sizeof (empty_dataset_kstats));
157 
158 	char *ds_name = kmem_zalloc(ZFS_MAX_DATASET_NAME_LEN, KM_SLEEP);
159 	dsl_dataset_name(objset->os_dsl_dataset, ds_name);
160 	KSTAT_NAMED_STR_PTR(&dk_kstats->dkv_ds_name) = ds_name;
161 	KSTAT_NAMED_STR_BUFLEN(&dk_kstats->dkv_ds_name) =
162 	    ZFS_MAX_DATASET_NAME_LEN;
163 
164 	kstat->ks_data = dk_kstats;
165 	kstat->ks_update = dataset_kstats_update;
166 	kstat->ks_private = dk;
167 	kstat->ks_data_size += ZFS_MAX_DATASET_NAME_LEN;
168 
169 	wmsum_init(&dk->dk_sums.dss_writes, 0);
170 	wmsum_init(&dk->dk_sums.dss_nwritten, 0);
171 	wmsum_init(&dk->dk_sums.dss_reads, 0);
172 	wmsum_init(&dk->dk_sums.dss_nread, 0);
173 	wmsum_init(&dk->dk_sums.dss_nunlinks, 0);
174 	wmsum_init(&dk->dk_sums.dss_nunlinked, 0);
175 	zil_sums_init(&dk->dk_zil_sums);
176 
177 	dk->dk_kstats = kstat;
178 	kstat_install(kstat);
179 	return (0);
180 }
181 
182 void
dataset_kstats_destroy(dataset_kstats_t * dk)183 dataset_kstats_destroy(dataset_kstats_t *dk)
184 {
185 	if (dk->dk_kstats == NULL)
186 		return;
187 
188 	dataset_kstat_values_t *dkv = dk->dk_kstats->ks_data;
189 	kstat_delete(dk->dk_kstats);
190 	dk->dk_kstats = NULL;
191 	kmem_free(KSTAT_NAMED_STR_PTR(&dkv->dkv_ds_name),
192 	    KSTAT_NAMED_STR_BUFLEN(&dkv->dkv_ds_name));
193 	kmem_free(dkv, sizeof (empty_dataset_kstats));
194 
195 	wmsum_fini(&dk->dk_sums.dss_writes);
196 	wmsum_fini(&dk->dk_sums.dss_nwritten);
197 	wmsum_fini(&dk->dk_sums.dss_reads);
198 	wmsum_fini(&dk->dk_sums.dss_nread);
199 	wmsum_fini(&dk->dk_sums.dss_nunlinks);
200 	wmsum_fini(&dk->dk_sums.dss_nunlinked);
201 	zil_sums_fini(&dk->dk_zil_sums);
202 }
203 
204 void
dataset_kstats_rename(dataset_kstats_t * dk,const char * name)205 dataset_kstats_rename(dataset_kstats_t *dk, const char *name)
206 {
207 	if (dk->dk_kstats == NULL)
208 		return;
209 
210 	dataset_kstat_values_t *dkv = dk->dk_kstats->ks_data;
211 	char *ds_name;
212 
213 	ds_name = KSTAT_NAMED_STR_PTR(&dkv->dkv_ds_name);
214 	ASSERT3S(ds_name, !=, NULL);
215 	(void) strlcpy(ds_name, name,
216 	    KSTAT_NAMED_STR_BUFLEN(&dkv->dkv_ds_name));
217 }
218 
219 void
dataset_kstats_update_write_kstats(dataset_kstats_t * dk,int64_t nwritten)220 dataset_kstats_update_write_kstats(dataset_kstats_t *dk, int64_t nwritten)
221 {
222 	ASSERT3S(nwritten, >=, 0);
223 
224 	if (dk->dk_kstats == NULL)
225 		return;
226 
227 	wmsum_add(&dk->dk_sums.dss_writes, 1);
228 	wmsum_add(&dk->dk_sums.dss_nwritten, nwritten);
229 }
230 
231 void
dataset_kstats_update_read_kstats(dataset_kstats_t * dk,int64_t nread)232 dataset_kstats_update_read_kstats(dataset_kstats_t *dk, int64_t nread)
233 {
234 	ASSERT3S(nread, >=, 0);
235 
236 	if (dk->dk_kstats == NULL)
237 		return;
238 
239 	wmsum_add(&dk->dk_sums.dss_reads, 1);
240 	wmsum_add(&dk->dk_sums.dss_nread, nread);
241 }
242 
243 void
dataset_kstats_update_nunlinks_kstat(dataset_kstats_t * dk,int64_t delta)244 dataset_kstats_update_nunlinks_kstat(dataset_kstats_t *dk, int64_t delta)
245 {
246 	if (dk->dk_kstats == NULL)
247 		return;
248 
249 	wmsum_add(&dk->dk_sums.dss_nunlinks, delta);
250 }
251 
252 void
dataset_kstats_update_nunlinked_kstat(dataset_kstats_t * dk,int64_t delta)253 dataset_kstats_update_nunlinked_kstat(dataset_kstats_t *dk, int64_t delta)
254 {
255 	if (dk->dk_kstats == NULL)
256 		return;
257 
258 	wmsum_add(&dk->dk_sums.dss_nunlinked, delta);
259 }
260