From 73afbff431cd4ac97e29db7f8fee79baf9751824 Mon Sep 17 00:00:00 2001 From: mav Date: Tue, 6 Aug 2013 14:41:41 +0000 Subject: [PATCH] Block reporting of ZFS features for suspended pools. Before executing any subcommand, zpool tool fetches pools configuration from the kernel. Before features support was added, kernel was regenerating that configuration based on data always present in memory. Unfortunately, pool features list and activity counters are not such. They are stored in ZAP, that normally resides in ARC, but under heavy memory pressure may be swapped out. If pool is suspended at this point, there is no way to recover it back since any zpool command will stuck. This change has one predictable flaw: `zpool upgrade` always wish to upgrade suspended pools, but fortunately it can't do it due to the suspension. --- sys/cddl/contrib/opensolaris/uts/common/fs/zfs/spa.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/spa.c b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/spa.c index 9cd7ed861b98..cd3fb798b82e 100644 --- a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/spa.c +++ b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/spa.c @@ -3060,6 +3060,10 @@ spa_add_feature_stats(spa_t *spa, nvlist_t *config) ASSERT(spa_config_held(spa, SCL_CONFIG, RW_READER)); VERIFY(nvlist_alloc(&features, NV_UNIQUE_NAME, KM_SLEEP) == 0); + /* We may be unable to read features if pool is suspended. */ + if (spa_suspended(spa)) + goto out; + if (spa->spa_feat_for_read_obj != 0) { for (zap_cursor_init(&zc, spa->spa_meta_objset, spa->spa_feat_for_read_obj); @@ -3086,6 +3090,7 @@ spa_add_feature_stats(spa_t *spa, nvlist_t *config) zap_cursor_fini(&zc); } +out: VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_FEATURE_STATS, features) == 0); nvlist_free(features);