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

[Jens Axboe <axboe@kernel.dk>]

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.

-- 
Jens Axboe