From d0136ee0a7baad1afc582465a1ff1de73a435016 Mon Sep 17 00:00:00 2001 From: Andrew Date: Wed, 18 May 2022 12:25:33 -0500 Subject: [PATCH] Expose zpool guids through kstats There are times when end-users may wish to have a fast and convenient method to get zpool guid without having to use libzfs. This commit exposes the zpool guid via kstats in similar manner to the zpool state. Reviewed-by: Alexander Motin Reviewed-by: Brian Behlendorf Signed-off-by: Andrew Walker Closes #13466 --- include/sys/spa.h | 1 + module/zfs/spa_stats.c | 48 ++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 49 insertions(+) diff --git a/include/sys/spa.h b/include/sys/spa.h index 86d9500305e7..9f268c5c6e0c 100644 --- a/include/sys/spa.h +++ b/include/sys/spa.h @@ -898,6 +898,7 @@ typedef struct spa_stats { spa_history_kstat_t tx_assign_histogram; spa_history_list_t mmp_history; spa_history_kstat_t state; /* pool state */ + spa_history_kstat_t guid; /* pool guid */ spa_history_kstat_t iostats; } spa_stats_t; diff --git a/module/zfs/spa_stats.c b/module/zfs/spa_stats.c index 2a75b37f020e..f1d644bc68ca 100644 --- a/module/zfs/spa_stats.c +++ b/module/zfs/spa_stats.c @@ -819,6 +819,41 @@ spa_state_init(spa_t *spa) kmem_strfree(name); } +static int +spa_guid_data(char *buf, size_t size, void *data) +{ + spa_t *spa = (spa_t *)data; + (void) snprintf(buf, size, "%llu\n", (u_longlong_t)spa_guid(spa)); + return (0); +} + +static void +spa_guid_init(spa_t *spa) +{ + spa_history_kstat_t *shk = &spa->spa_stats.guid; + char *name; + kstat_t *ksp; + + mutex_init(&shk->lock, NULL, MUTEX_DEFAULT, NULL); + + name = kmem_asprintf("zfs/%s", spa_name(spa)); + + ksp = kstat_create(name, 0, "guid", "misc", + KSTAT_TYPE_RAW, 0, KSTAT_FLAG_VIRTUAL); + + shk->kstat = ksp; + if (ksp) { + ksp->ks_lock = &shk->lock; + ksp->ks_data = NULL; + ksp->ks_private = spa; + ksp->ks_flags |= KSTAT_FLAG_NO_HEADERS; + kstat_set_raw_ops(ksp, NULL, spa_guid_data, spa_state_addr); + kstat_install(ksp); + } + + kmem_strfree(name); +} + static void spa_health_destroy(spa_t *spa) { @@ -830,6 +865,17 @@ spa_health_destroy(spa_t *spa) mutex_destroy(&shk->lock); } +static void +spa_guid_destroy(spa_t *spa) +{ + spa_history_kstat_t *shk = &spa->spa_stats.guid; + kstat_t *ksp = shk->kstat; + if (ksp) + kstat_delete(ksp); + + mutex_destroy(&shk->lock); +} + static const spa_iostats_t spa_iostats_template = { { "trim_extents_written", KSTAT_DATA_UINT64 }, { "trim_bytes_written", KSTAT_DATA_UINT64 }, @@ -950,6 +996,7 @@ spa_stats_init(spa_t *spa) spa_tx_assign_init(spa); spa_mmp_history_init(spa); spa_state_init(spa); + spa_guid_init(spa); spa_iostats_init(spa); } @@ -962,6 +1009,7 @@ spa_stats_destroy(spa_t *spa) spa_txg_history_destroy(spa); spa_read_history_destroy(spa); spa_mmp_history_destroy(spa); + spa_guid_destroy(spa); } ZFS_MODULE_PARAM(zfs, zfs_, read_history, INT, ZMOD_RW,