module/zfs/dataset_kstats.c

   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 }