Re: [PATCH 1/2] block: modify blk_mq_plug() to allow only reads for zoned block devices

[Christoph Hellwig <hch@xxxxxxxxxxxxx>]

On Tue, Sep 27, 2022 at 10:04:19AM -0600, Jens Axboe wrote:
> Ah yes, good point. We used to have this notion of 'fs' request, don't
> think we do anymore. Because it really should just be:

A fs request is a !passthrough request.

> if (zoned && (op & REQ_OP_WRITE) && fs_request)
>          return NULL;
> 
> for that condition imho. I guess we could make it:
> 
> if (zoned && (op & REQ_OP_WRITE) && !(op & REQ_OP_DRV_OUT))
>          return NULL;

Well, the only opcodes we do zone locking for is REQ_OP_WRITE and
REQ_OP_WRITE_ZEROES.  So this should be:

	if (zoned && (op == REQ_OP_WRITE || op == REQ_OP_WRITE_ZEROES))
		return NULL;