null_blk: mem garbage on NUMA systems during init
authorMatias Bjorling <m@bjorling.me>
Tue, 10 Dec 2013 15:50:38 +0000 (16:50 +0100)
committerLinus Torvalds <torvalds@linux-foundation.org>
Sun, 15 Dec 2013 20:17:16 +0000 (12:17 -0800)
commit57053d8c5c59562cac156513740c10b502a40968
tree0e71310912a1004760561540bc7e665957468ee5
parente4158f1b1090d362a7c998bd654cc3fe8f5c863c
null_blk: mem garbage on NUMA systems during init

For NUMA systems, initializing the blk-mq layer and using per node hctx.
We initialize submit queues to 1, while blk-mq nr_hw_queues is
initialized to the number of NUMA nodes.

This makes the null_init_hctx function overwrite memory outside of what
it allocated.  In my case it lead to writing garbage into struct
request_queue's mq_map.

Signed-off-by: Matias Bjorling <m@bjorling.me>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/block/null_blk.c