Re: [PATCH] block: fix direct dispatch issue failure for clones

[Bart Van Assche <bvanassche@acm.org>]

On Thu, 2018-12-06 at 15:21 -0700, Jens Axboe wrote:
> On 12/6/18 3:20 PM, Jens Axboe wrote:
> > After the direct dispatch corruption fix, we permanently disallow direct
> > dispatch of non read/write requests. This works fine off the normal IO
> > path, as they will be retried like any other failed direct dispatch
> > request. But for the blk_insert_cloned_request() that only DM uses to
> > bypass the bottom level scheduler, we always first attempt direct
> > dispatch. For some types of requests, that's now a permanent failure,
> > and no amount of retrying will make that succeed.
> > 
> > Don't use direct dispatch off the cloned insert path, always just use
> > bypass inserts. This still bypasses the bottom level scheduler, which is
> > what DM wants.
> > 
> > Fixes: ffe81d45322c ("blk-mq: fix corruption with direct issue")
> > Signed-off-by: Jens Axboe <axboe@kernel.dk>
> 
> Bart, I'll add your reported-by here of course, and also a stable CC
> since the original patch went into stable.

Feel free to add the following:

Tested-by: Bart Van Assche <bvanassche@acm.org>