tree 79c7b943d7c6d62fec1874afd2c50964de054aa0
parent bb5c3cdda37aad22996d6da2addd58cadc0436c0
author Shaohua Li <shli@fb.com> 1421371945 -0800
committer Jens Axboe <axboe@fb.com> 1422047746 -0700

block: support different tag allocation policy

The libata tag allocation is using a round-robin policy. Next patch will
make libata use block generic tag allocation, so let's add a policy to
tag allocation.

Currently two policies: FIFO (default) and round-robin.

Cc: Jens Axboe <axboe@fb.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>