block: move the stable_writes flag to queue_limits
Move the stable_writes flag into the queue_limits feature field so that
it can be set atomically with the queue frozen.
The flag is now inherited by blk_stack_limits, which greatly simplifies
the code in dm, and fixed md which previously did not pass on the flag
set on lower devices.
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
projects / users / hch / block.git / commit