[PATCH v3 30/30] block: Do not special-case plugging of zone write operations

[Christoph Hellwig]

On Thu, Mar 28, 2024 at 09:44:09AM +0900, Damien Le Moal wrote:
> With the block layer zone write plugging being automatically done for
> any write operation to a zone of a zoned block device, a regular request
> plugging handled through current->plug can only ever see at most a
> single write request per zone. In such case, any potential reordering
> of the plugged requests will be harmless. We can thus remove the special
> casing for write operations to zones and have these requests plugged as
> well. This allows removing the function blk_mq_plug and instead directly
> using current->plug where needed.

This looks good in general:

Reviewed-by: Christoph Hellwig <hch at lst.de>

But IIRC we recently had a report that plus reorder I/Os, which would
be grave for the extent layout if we haven't fixed that yet, so we
should probably look into it first.