How do I detect a block device is being used as swap inside its requestqueue handler?

[Richard Yao]

Dear Linus Torvalds et al,

I am having some trouble with an out of tree module for a virtual block
device driver. I need to disable the direct reclaim path when the device
is used as swap. I cannot see a way to detect that the device is being
used as swap, so I am currently disabling it unconditionally.

Is there a clean way to detect that the block device is being used as
swap? I am not subscribed to the list, so please CC replies to me.

Yours truly,
Richard Yao

Attachment: signature.asc
Description: OpenPGP digital signature