Allan Jude c79b58ccc5 Pull in a follow-on commit to resolve a deadlock in ZFS sequential ... resilver (r334844) MFV/ZoL: Fix deadlock in IO pipeline commit a76f3d0437 Author: Brian Behlendorf <behlendorf1@llnl.gov> Date: Fri Mar 16 16:46:06 2018 -0700 Fix deadlock in IO pipeline In vdev_queue_aggregate() the zio_execute() bypass should not be called under the vdev queue lock. This can result in a deadlock as shown in the stack traces below. Drop the vdev queue lock then walk the parents of the aggregate IO to determine the list of component IOs to be bypassed. This can be done safely without holding the io_lock since the new aggregate IO has not yet been returned and its parents cannot change. --- THREAD 1 --- arc_read() zio_nowait() zio_vdev_io_start() vdev_queue_io() <--- mutex_enter(vq->vq_lock) vdev_queue_io_to_issue() vdev_queue_aggregate() zio_execute() vdev_queue_io_to_issue() vdev_queue_aggregate() zio_execute() zio_vdev_io_assess() zio_wait_for_children() <- mutex_enter(zio->io_lock) --- THREAD 2 --- (inverse order) arc_read() zio_change_priority() <- mutex_enter(zio->zio_lock) vdev_queue_change_io_priority() <- mutex_enter(vq->vq_lock) Reviewed-by: Tom Caputi <tcaputi@datto.com> Reviewed-by: Don Brady <don.brady@delphix.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Reported by: ZFS Leadership Meeting Reviewed by: mav Approved by: re (kib) Obtained from: ZFS-on-Linux MFC after: 2 weeks Sponsored by: Klara Systems Differential Revision: https://reviews.freebsd.org/D17495		2018-10-10 22:59:15 +00:00
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opensolaris	Pull in a follow-on commit to resolve a deadlock in ZFS sequential	2018-10-10 22:59:15 +00:00