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authorNed Bass <[email protected]>2015-02-26 12:24:11 -0800
committerBrian Behlendorf <[email protected]>2015-03-05 14:11:10 -0800
commit417104bdd3c7ce07ec58674dd078f9891c3bc780 (patch)
treed1a19daa843375394ececb2cf8098d42adaae79d /include/sys
parent0e86d309ccc53e7d6093f8cf2bb09858f63267ac (diff)
Use cached feature info in spa_add_feature_stats()
Avoid issuing I/O to the pool when retrieving feature flags information. Trying to read the ZAPs from disk means that zpool clear would hang if the pool is suspended and recovery would require a reboot. To keep the feature stats resident in memory, we hang a cached nvlist off of the spa. It is built up from disk the first time spa_add_feature_stats() is called, and refreshed thereafter using the cached feature reference counts. spa_add_feature_stats() gets called at pool import time so we can be sure the cached nvlist will be available if the pool is later suspended. Signed-off-by: Ned Bass <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes #3082
Diffstat (limited to 'include/sys')
-rw-r--r--include/sys/spa_impl.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/include/sys/spa_impl.h b/include/sys/spa_impl.h
index 1cb535b9f..72e04e8cf 100644
--- a/include/sys/spa_impl.h
+++ b/include/sys/spa_impl.h
@@ -236,6 +236,7 @@ struct spa {
uint64_t spa_feat_for_read_obj; /* required to read from pool */
uint64_t spa_feat_desc_obj; /* Feature descriptions */
uint64_t spa_feat_enabled_txg_obj; /* Feature enabled txg */
+ nvlist_t *spa_feat_stats; /* Cache of enabled features */
/* cache feature refcounts */
uint64_t spa_feat_refcount_cache[SPA_FEATURES];
taskqid_t spa_deadman_tqid; /* Task id */