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) 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 42 static int 43 dataset_kstats_update(kstat_t *ksp, int rw) 44 { 45 dataset_kstats_t *dk = ksp->ks_private; 46 ASSERT3P(dk->dk_kstats->ks_data, ==, ksp->ks_data); 47 48 if (rw == KSTAT_WRITE) 49 return (EACCES); 50 51 dataset_kstat_values_t *dkv = dk->dk_kstats->ks_data; 52 dkv->dkv_writes.value.ui64 = 53 wmsum_value(&dk->dk_sums.dss_writes); 54 dkv->dkv_nwritten.value.ui64 = 55 wmsum_value(&dk->dk_sums.dss_nwritten); 56 dkv->dkv_reads.value.ui64 = 57 wmsum_value(&dk->dk_sums.dss_reads); 58 dkv->dkv_nread.value.ui64 = 59 wmsum_value(&dk->dk_sums.dss_nread); 60 dkv->dkv_nunlinks.value.ui64 = 61 wmsum_value(&dk->dk_sums.dss_nunlinks); 62 dkv->dkv_nunlinked.value.ui64 = 63 wmsum_value(&dk->dk_sums.dss_nunlinked); 64 65 return (0); 66 } 67 68 void 69 dataset_kstats_create(dataset_kstats_t *dk, objset_t *objset) 70 { 71 /* 72 * There should not be anything wrong with having kstats for 73 * snapshots. Since we are not sure how useful they would be 74 * though nor how much their memory overhead would matter in 75 * a filesystem with many snapshots, we skip them for now. 76 */ 77 if (dmu_objset_is_snapshot(objset)) 78 return; 79 80 /* 81 * At the time of this writing, KSTAT_STRLEN is 255 in Linux, 82 * and the spa_name can theoretically be up to 256 characters. 83 * In reality though the spa_name can be 240 characters max 84 * [see origin directory name check in pool_namecheck()]. Thus, 85 * the naming scheme for the module name below should not cause 86 * any truncations. In the event that a truncation does happen 87 * though, due to some future change, we silently skip creating 88 * the kstat and log the event. 89 */ 90 char kstat_module_name[KSTAT_STRLEN]; 91 int n = snprintf(kstat_module_name, sizeof (kstat_module_name), 92 "zfs/%s", spa_name(dmu_objset_spa(objset))); 93 if (n < 0) { 94 zfs_dbgmsg("failed to create dataset kstat for objset %lld: " 95 " snprintf() for kstat module name returned %d", 96 (unsigned long long)dmu_objset_id(objset), n); 97 return; 98 } else if (n >= KSTAT_STRLEN) { 99 zfs_dbgmsg("failed to create dataset kstat for objset %lld: " 100 "kstat module name length (%d) exceeds limit (%d)", 101 (unsigned long long)dmu_objset_id(objset), 102 n, KSTAT_STRLEN); 103 return; 104 } 105 106 char kstat_name[KSTAT_STRLEN]; 107 n = snprintf(kstat_name, sizeof (kstat_name), "objset-0x%llx", 108 (unsigned long long)dmu_objset_id(objset)); 109 if (n < 0) { 110 zfs_dbgmsg("failed to create dataset kstat for objset %lld: " 111 " snprintf() for kstat name returned %d", 112 (unsigned long long)dmu_objset_id(objset), n); 113 return; 114 } 115 ASSERT3U(n, <, KSTAT_STRLEN); 116 117 kstat_t *kstat = kstat_create(kstat_module_name, 0, kstat_name, 118 "dataset", KSTAT_TYPE_NAMED, 119 sizeof (empty_dataset_kstats) / sizeof (kstat_named_t), 120 KSTAT_FLAG_VIRTUAL); 121 if (kstat == NULL) 122 return; 123 124 dataset_kstat_values_t *dk_kstats = 125 kmem_alloc(sizeof (empty_dataset_kstats), KM_SLEEP); 126 memcpy(dk_kstats, &empty_dataset_kstats, 127 sizeof (empty_dataset_kstats)); 128 129 char *ds_name = kmem_zalloc(ZFS_MAX_DATASET_NAME_LEN, KM_SLEEP); 130 dsl_dataset_name(objset->os_dsl_dataset, ds_name); 131 KSTAT_NAMED_STR_PTR(&dk_kstats->dkv_ds_name) = ds_name; 132 KSTAT_NAMED_STR_BUFLEN(&dk_kstats->dkv_ds_name) = 133 ZFS_MAX_DATASET_NAME_LEN; 134 135 kstat->ks_data = dk_kstats; 136 kstat->ks_update = dataset_kstats_update; 137 kstat->ks_private = dk; 138 kstat->ks_data_size += ZFS_MAX_DATASET_NAME_LEN; 139 140 kstat_install(kstat); 141 dk->dk_kstats = kstat; 142 143 wmsum_init(&dk->dk_sums.dss_writes, 0); 144 wmsum_init(&dk->dk_sums.dss_nwritten, 0); 145 wmsum_init(&dk->dk_sums.dss_reads, 0); 146 wmsum_init(&dk->dk_sums.dss_nread, 0); 147 wmsum_init(&dk->dk_sums.dss_nunlinks, 0); 148 wmsum_init(&dk->dk_sums.dss_nunlinked, 0); 149 } 150 151 void 152 dataset_kstats_destroy(dataset_kstats_t *dk) 153 { 154 if (dk->dk_kstats == NULL) 155 return; 156 157 dataset_kstat_values_t *dkv = dk->dk_kstats->ks_data; 158 kmem_free(KSTAT_NAMED_STR_PTR(&dkv->dkv_ds_name), 159 KSTAT_NAMED_STR_BUFLEN(&dkv->dkv_ds_name)); 160 kmem_free(dkv, sizeof (empty_dataset_kstats)); 161 162 kstat_delete(dk->dk_kstats); 163 dk->dk_kstats = NULL; 164 165 wmsum_fini(&dk->dk_sums.dss_writes); 166 wmsum_fini(&dk->dk_sums.dss_nwritten); 167 wmsum_fini(&dk->dk_sums.dss_reads); 168 wmsum_fini(&dk->dk_sums.dss_nread); 169 wmsum_fini(&dk->dk_sums.dss_nunlinks); 170 wmsum_fini(&dk->dk_sums.dss_nunlinked); 171 } 172 173 void 174 dataset_kstats_update_write_kstats(dataset_kstats_t *dk, 175 int64_t nwritten) 176 { 177 ASSERT3S(nwritten, >=, 0); 178 179 if (dk->dk_kstats == NULL) 180 return; 181 182 wmsum_add(&dk->dk_sums.dss_writes, 1); 183 wmsum_add(&dk->dk_sums.dss_nwritten, nwritten); 184 } 185 186 void 187 dataset_kstats_update_read_kstats(dataset_kstats_t *dk, 188 int64_t nread) 189 { 190 ASSERT3S(nread, >=, 0); 191 192 if (dk->dk_kstats == NULL) 193 return; 194 195 wmsum_add(&dk->dk_sums.dss_reads, 1); 196 wmsum_add(&dk->dk_sums.dss_nread, nread); 197 } 198 199 void 200 dataset_kstats_update_nunlinks_kstat(dataset_kstats_t *dk, int64_t delta) 201 { 202 if (dk->dk_kstats == NULL) 203 return; 204 205 wmsum_add(&dk->dk_sums.dss_nunlinks, delta); 206 } 207 208 void 209 dataset_kstats_update_nunlinked_kstat(dataset_kstats_t *dk, int64_t delta) 210 { 211 if (dk->dk_kstats == NULL) 212 return; 213 214 wmsum_add(&dk->dk_sums.dss_nunlinked, delta); 215 } 216