svn commit: r224920 - projects/zfsd/head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs

[Pawel Jakub Dawidek]

On Tue, Aug 16, 2011 at 10:20:45PM +0000, Justin T. Gibbs wrote:
> Author: gibbs
> Date: Tue Aug 16 22:20:45 2011
> New Revision: 224920
> URL: http://svn.freebsd.org/changeset/base/224920
> 
> Log:
>   Close several race conditions in the ZFS vdev geom module, most triggered
>   by concurrent ZFS reprobe and GEOM orphan processing.
>   
>   sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev_geom.c:
>   	o Make vdev_geom_close() synchronous instead of deferring
>   	  its work to a GEOM event handler.  This prevents a future
>   	  open call from referencing a consumer that is scheduled for
>   	  destruction.
[...]
> @@ -547,9 +558,9 @@ vdev_geom_close(vdev_t *vd)
>  	cp = vd->vdev_tsd;
>  	if (cp == NULL)
>  		return;
> -	vd->vdev_tsd = NULL;
> -	vd->vdev_delayed_close = B_FALSE;
> -	g_post_event(vdev_geom_detach, cp, M_WAITOK, NULL);
> +	g_topology_lock();
> +	vdev_geom_detach(cp);
> +	g_topology_unlock();

This reverts the @104422 change I made. The reason for deatching vdev
from the GEOM event thread was that I was experiencing deadlocks when
trying to acquire the topology lock in vdev_geom_close().

It was long time ago, so the deadlock might not be there anymore as
there were a lot of changes to the locking in the meantime (it might
have been due to LOR between the topology lock and the
spa_namespace_lock/spa_config, which is no longer a problem).

Just FYI.

-- 
Pawel Jakub Dawidek                       http://www.wheelsystems.com
FreeBSD committer                         http://www.FreeBSD.org
Am I Evil? Yes, I Am!                     http://yomoli.com
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