From 045f8bc8e4b096d8828d120d4e4a8f3bd39b9b73 Mon Sep 17 00:00:00 2001 From: Warner Losh Date: Thu, 11 Jan 2018 03:11:41 +0000 Subject: [PATCH] When we crash, we'll stop the scheduler before we call the shutdown_post_sync event. For adashutdown, this causes problems because we need to poll for completion of the commands, but we're not yet officially dumping yet, so the code from r326964 assumed we could use the interrupt-driven commands rather than the polled ones. This lead to a hang. Prevent this by also checking to see if the scheduler is stopped to do the polling. Reported by: markj@ Sponsored by: Netflix Differential Review: https://reviews.freebsd.org/D13845 --- sys/cam/cam_periph.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/sys/cam/cam_periph.c b/sys/cam/cam_periph.c index b9c3dcf76ee..6cb4583e92d 100644 --- a/sys/cam/cam_periph.c +++ b/sys/cam/cam_periph.c @@ -1187,10 +1187,16 @@ cam_periph_runccb(union ccb *ccb, * scheduler is running in this case, we still need to poll the I/O to * avoid sleeping waiting for the ccb to complete. * - * XXX To avoid locking problems, dumping/polling callers must call + * A panic triggered dump stops the scheduler, any callback from the + * shutdown_post_sync event will run with the scheduler stopped, but + * before we're officially dumping. To avoid hanging in adashutdown + * initiated commands (or other similar situations), we have to test for + * either SCHEDULER_STOPPED() here as well. + * + * To avoid locking problems, dumping/polling callers must call * without a periph lock held. */ - must_poll = dumping; + must_poll = dumping || SCHEDULER_STOPPED(); ccb->ccb_h.cbfcnp = cam_periph_done; /*