Avoid panic when adjusting priority of a read in the face of an IO error

PR:		231516
Reported by:	sbruno
Approved by:	re (rgrimes)
Obtained from:	ZFS-on-Linux
X-MFC-with:	334844
Sponsored by:	Klara Systems

MFV/ZoL:	Fix zio->io_priority failed (7 < 6) assert

commit c26cf0966d
Author: Tony Hutter <hutter2@llnl.gov>
Date:   Tue May 29 18:13:48 2018 -0700

  Fix zio->io_priority failed (7 < 6) assert

  This fixes an assert in vdev_queue_change_io_priority():

    VERIFY3(zio->io_priority < ZIO_PRIORITY_NUM_QUEUEABLE) failed (7 < 6)
    PANIC at vdev_queue.c:832:vdev_queue_change_io_priority()

  Reviewed-by: Tom Caputi <tcaputi@datto.com>
  Reviewed-by: George Melikov <mail@gmelikov.ru>
  Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
  Signed-off-by: Tony Hutter <hutter2@llnl.gov>
This commit is contained in:
Allan Jude 2018-09-29 01:26:07 +00:00
parent 2a99321a57
commit 9d967dd27d

View File

@ -958,6 +958,15 @@ vdev_queue_change_io_priority(zio_t *zio, zio_priority_t priority)
vdev_queue_t *vq = &zio->io_vd->vdev_queue;
avl_tree_t *tree;
/*
* ZIO_PRIORITY_NOW is used by the vdev cache code and the aggregate zio
* code to issue IOs without adding them to the vdev queue. In this
* case, the zio is already going to be issued as quickly as possible
* and so it doesn't need any reprioitization to help.
*/
if (zio->io_priority == ZIO_PRIORITY_NOW)
return;
ASSERT3U(zio->io_priority, <, ZIO_PRIORITY_NUM_QUEUEABLE);
ASSERT3U(priority, <, ZIO_PRIORITY_NUM_QUEUEABLE);