diff options
Diffstat (limited to 'module/zfs/dataset_kstats.c')
| -rw-r--r-- | module/zfs/dataset_kstats.c | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/module/zfs/dataset_kstats.c b/module/zfs/dataset_kstats.c new file mode 100644 index 000000000..ac0ad84ed --- /dev/null +++ b/module/zfs/dataset_kstats.c @@ -0,0 +1,185 @@ +/* + * CDDL HEADER START + * + * The contents of this file are subject to the terms of the + * Common Development and Distribution License (the "License"). + * You may not use this file except in compliance with the License. + * + * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE + * or http://www.opensolaris.org/os/licensing. + * See the License for the specific language governing permissions + * and limitations under the License. + * + * When distributing Covered Code, include this CDDL HEADER in each + * file and include the License file at usr/src/OPENSOLARIS.LICENSE. + * If applicable, add the following below this CDDL HEADER, with the + * fields enclosed by brackets "[]" replaced with your own identifying + * information: Portions Copyright [yyyy] [name of copyright owner] + * + * CDDL HEADER END + */ + +/* + * Copyright (c) 2018 by Delphix. All rights reserved. + */ + +#include <sys/dataset_kstats.h> +#include <sys/dmu_objset.h> +#include <sys/dsl_dataset.h> +#include <sys/spa.h> + +static dataset_kstat_values_t empty_dataset_kstats = { + { "dataset_name", KSTAT_DATA_STRING }, + { "writes", KSTAT_DATA_UINT64 }, + { "nwritten", KSTAT_DATA_UINT64 }, + { "reads", KSTAT_DATA_UINT64 }, + { "nread", KSTAT_DATA_UINT64 }, +}; + +static int +dataset_kstats_update(kstat_t *ksp, int rw) +{ + dataset_kstats_t *dk = ksp->ks_private; + ASSERT3P(dk->dk_kstats->ks_data, ==, ksp->ks_data); + + if (rw == KSTAT_WRITE) + return (EACCES); + + dataset_kstat_values_t *dkv = dk->dk_kstats->ks_data; + dkv->dkv_writes.value.ui64 = + aggsum_value(&dk->dk_aggsums.das_writes); + dkv->dkv_nwritten.value.ui64 = + aggsum_value(&dk->dk_aggsums.das_nwritten); + dkv->dkv_reads.value.ui64 = + aggsum_value(&dk->dk_aggsums.das_reads); + dkv->dkv_nread.value.ui64 = + aggsum_value(&dk->dk_aggsums.das_nread); + + return (0); +} + +void +dataset_kstats_create(dataset_kstats_t *dk, objset_t *objset) +{ + /* + * There should not be anything wrong with having kstats for + * snapshots. Since we are not sure how useful they would be + * though nor how much their memory overhead would matter in + * a filesystem with many snapshots, we skip them for now. + */ + if (dmu_objset_is_snapshot(objset)) + return; + + /* + * At the time of this writing, KSTAT_STRLEN is 255 in Linux, + * and the spa_name can theoretically be up to 256 characters. + * In reality though the spa_name can be 240 characters max + * [see origin directory name check in pool_namecheck()]. Thus, + * the naming scheme for the module name below should not cause + * any truncations. In the event that a truncation does happen + * though, due to some future change, we silently skip creating + * the kstat and log the event. + */ + char kstat_module_name[KSTAT_STRLEN]; + int n = snprintf(kstat_module_name, sizeof (kstat_module_name), + "zfs/%s", spa_name(dmu_objset_spa(objset))); + if (n < 0) { + zfs_dbgmsg("failed to create dataset kstat for objset %lld: " + " snprintf() for kstat module name returned %d", + (unsigned long long)dmu_objset_id(objset), n); + return; + } else if (n >= KSTAT_STRLEN) { + zfs_dbgmsg("failed to create dataset kstat for objset %lld: " + "kstat module name length (%d) exceeds limit (%d)", + (unsigned long long)dmu_objset_id(objset), + n, KSTAT_STRLEN); + return; + } + + char kstat_name[KSTAT_STRLEN]; + n = snprintf(kstat_name, sizeof (kstat_name), "objset-0x%llx", + (unsigned long long)dmu_objset_id(objset)); + if (n < 0) { + zfs_dbgmsg("failed to create dataset kstat for objset %lld: " + " snprintf() for kstat name returned %d", + (unsigned long long)dmu_objset_id(objset), n); + return; + } + ASSERT3U(n, <, KSTAT_STRLEN); + + kstat_t *kstat = kstat_create(kstat_module_name, 0, kstat_name, + "dataset", KSTAT_TYPE_NAMED, + sizeof (empty_dataset_kstats) / sizeof (kstat_named_t), + KSTAT_FLAG_VIRTUAL); + if (kstat == NULL) + return; + + dataset_kstat_values_t *dk_kstats = + kmem_alloc(sizeof (empty_dataset_kstats), KM_SLEEP); + bcopy(&empty_dataset_kstats, dk_kstats, + sizeof (empty_dataset_kstats)); + + char *ds_name = kmem_zalloc(ZFS_MAX_DATASET_NAME_LEN, KM_SLEEP); + dsl_dataset_name(objset->os_dsl_dataset, ds_name); + KSTAT_NAMED_STR_PTR(&dk_kstats->dkv_ds_name) = ds_name; + KSTAT_NAMED_STR_BUFLEN(&dk_kstats->dkv_ds_name) = + ZFS_MAX_DATASET_NAME_LEN; + + kstat->ks_data = dk_kstats; + kstat->ks_update = dataset_kstats_update; + kstat->ks_private = dk; + + kstat_install(kstat); + dk->dk_kstats = kstat; + + aggsum_init(&dk->dk_aggsums.das_writes, 0); + aggsum_init(&dk->dk_aggsums.das_nwritten, 0); + aggsum_init(&dk->dk_aggsums.das_reads, 0); + aggsum_init(&dk->dk_aggsums.das_nread, 0); +} + +void +dataset_kstats_destroy(dataset_kstats_t *dk) +{ + if (dk->dk_kstats == NULL) + return; + + dataset_kstat_values_t *dkv = dk->dk_kstats->ks_data; + kmem_free(KSTAT_NAMED_STR_PTR(&dkv->dkv_ds_name), + KSTAT_NAMED_STR_BUFLEN(&dkv->dkv_ds_name)); + kmem_free(dkv, sizeof (empty_dataset_kstats)); + + kstat_delete(dk->dk_kstats); + dk->dk_kstats = NULL; + + aggsum_fini(&dk->dk_aggsums.das_writes); + aggsum_fini(&dk->dk_aggsums.das_nwritten); + aggsum_fini(&dk->dk_aggsums.das_reads); + aggsum_fini(&dk->dk_aggsums.das_nread); +} + +void +dataset_kstats_update_write_kstats(dataset_kstats_t *dk, + int64_t nwritten) +{ + ASSERT3S(nwritten, >=, 0); + + if (dk->dk_kstats == NULL) + return; + + aggsum_add(&dk->dk_aggsums.das_writes, 1); + aggsum_add(&dk->dk_aggsums.das_nwritten, nwritten); +} + +void +dataset_kstats_update_read_kstats(dataset_kstats_t *dk, + int64_t nread) +{ + ASSERT3S(nread, >=, 0); + + if (dk->dk_kstats == NULL) + return; + + aggsum_add(&dk->dk_aggsums.das_reads, 1); + aggsum_add(&dk->dk_aggsums.das_nread, nread); +} |