tree 3fc6db73809742be0f0fdf403c77af02a6feeeba
parent 93252632e828da3e90241a1c0e766556abf71598
author Omar Sandoval <osandov@fb.com> 1491576747 -0600
committer Jens Axboe <axboe@fb.com> 1491577008 -0600

blk-mq-sched: fix crash in switch error path

In elevator_switch(), if blk_mq_init_sched() fails, we attempt to fall
back to the original scheduler. However, at this point, we've already
torn down the original scheduler's tags, so this causes a crash. Doing
the fallback like the legacy elevator path is much harder for mq, so fix
it by just falling back to none, instead.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>