zfs initialize performance enhancements

PROBLEM
========

When invoking "zpool initialize" on a pool the command will
create a thread to initialize each disk. Unfortunately, it does
this serially across many transaction groups which can result
in commands taking a long time to return to the user and may
appear hung. The same thing is true when trying to suspend/cancel
the operation.

SOLUTION
=========

This change refactors the way we invoke the initialize interface
to ensure we can start or stop the intialization in just a few
transaction groups.

When stopping or cancelling a vdev initialization perform it
in two phases.  First signal each vdev initialization thread
that it should exit, then after all threads have been signaled
wait for them to exit.

On a pool with 40 leaf vdevs this reduces the vdev initialize
stop/cancel time from ~10 minutes to under a second.  The reason
for this is spa_vdev_initialize() no longer needs to wait on
multiple full TXGs per leaf vdev being stopped.

This commit additionally adds some missing checks for the passed
"initialize_vdevs" input nvlist.  The contents of the user provided
input "initialize_vdevs" nvlist must be validated to ensure all
values are uint64s.  This is done in zfs_ioc_pool_initialize() in
order to keep all of these checks in a single location.

Updated the innvl and outnvl comments to match the formatting used
for all other new sytle ioctls.

Reviewed by: Matt Ahrens <[email protected]>
Reviewed-by: loli10K <[email protected]>
Reviewed-by: Tim Chase <[email protected]>
Signed-off-by: Brian Behlendorf <[email protected]>
Signed-off-by: George Wilson <[email protected]>
Closes #8230

1 files changed, 4 insertions, 1 deletions

diff --git a/include/sys/vdev_initialize.h b/include/sys/vdev_initialize.h
index db4b0572c..319fb9bc0 100644
--- a/include/sys/vdev_initialize.h
+++ b/include/sys/vdev_initialize.h
@@ -26,15 +26,18 @@
 #ifndef _SYS_VDEV_INITIALIZE_H
 #define	_SYS_VDEV_INITIALIZE_H
 
+#include <sys/spa.h>
+
 #ifdef	__cplusplus
 extern "C" {
 #endif
 
 extern void vdev_initialize(vdev_t *vd);
 extern void vdev_initialize_stop(vdev_t *vd,
-    vdev_initializing_state_t tgt_state);
+    vdev_initializing_state_t tgt_state, list_t *vd_list);
 extern void vdev_initialize_stop_all(vdev_t *vd,
     vdev_initializing_state_t tgt_state);
+extern void vdev_initialize_stop_wait(spa_t *spa, list_t *vd_list);
 extern void vdev_initialize_restart(vdev_t *vd);
 extern void vdev_xlate(vdev_t *vd, const range_seg_t *logical_rs,
     range_seg_t *physical_rs);