null_blk: add support for shared tags
authorJens Axboe <axboe@kernel.dk>
Tue, 20 Jun 2017 20:22:01 +0000 (14:22 -0600)
committerJens Axboe <axboe@kernel.dk>
Tue, 20 Jun 2017 20:22:01 +0000 (14:22 -0600)
commit82f402fefa50f1675bf918bcd009981bd6b30ac8
treeda5a8eeee2aaaad6146c669ce56e92b4ce8acc2e
parentedf064e7c6fec3646b06c944a8e35d1a3de5c2c3
null_blk: add support for shared tags

Some storage drivers need to share tag sets between devices. It's
useful to be able to model that with null_blk, to find hangs or
performance issues.

Add a 'shared_tags' bool module parameter that. If that is set to
true and nr_devices is bigger than 1, all devices allocated will
share the same tag set.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
drivers/block/null_blk.c