block: respect queue limit of max discard segment

When queue_max_discard_segments(q) is 1, blk_discard_mergable() will
return false for discard request, then normal request merge is applied.
However, only queue_max_segments() is checked, so max discard segment
limit isn't respected.

Check max discard segment limit in the request merge code for fixing
the issue.

Discard request failure of virtio_blk is fixed.

Fixes: 69840466086d ("block: fix the DISCARD request merge")
Signed-off-by: Ming Lei <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Cc: Stefano Garzarella <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>

0 files changed, 0 insertions, 0 deletions