f7b60097b5
Using zvols as backing devices for ZFS pools is fraught with panics and deadlocks. For example, attempting to online a missing device in the presence of a zvol can cause a panic when vdev_geom tastes the zvol. Better to completely disable vdev_geom from ever opening a zvol. The solution relies on setting a thread-local variable during vdev_geom_open, and returning EOPNOTSUPP during zvol_open if that thread-local variable is set. Remove the check for MUTEX_HELD(&zfsdev_state_lock) in zvol_open. Its intent was to prevent a recursive mutex acquisition panic. However, the new check for the thread-local variable also fixes that problem. Also, fix a panic in vdev_geom_taste_orphan. For an unknown reason, this function was set to panic. But it can occur that a device disappears during tasting, and it causes no problems to ignore this departure. Reviewed by: delphij MFC after: 1 week Relnotes: yes Sponsored by: Spectra Logic Corp Differential Revision: https://reviews.freebsd.org/D4986 |
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| OPENSOLARIS.LICENSE | ||