tree 8a87578fc6753431f9d698703ad0217392916f3e
parent 849a370016a5489c49253338507ee6cc4a08df4b
author Jens Axboe <axboe@kernel.dk> 1541536255 -0700
committer Jens Axboe <axboe@kernel.dk> 1542641690 -0700

block: have ->poll_fn() return number of entries polled

We currently only really support sync poll, ie poll with 1 IO in flight.
This prepares us for supporting async poll.

Note that the returned value isn't necessarily 100% accurate. If poll
races with IRQ completion, we assume that the fact that the task is now
runnable means we found at least one entry. In reality it could be more
than 1, or not even 1. This is fine, the caller will just need to take
this into account.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>