blk-mq: fix race in IO start accounting
authorJens Axboe <axboe@fb.com>
Fri, 9 May 2014 20:54:08 +0000 (14:54 -0600)
committerJens Axboe <axboe@fb.com>
Fri, 9 May 2014 20:54:08 +0000 (14:54 -0600)
commitcf4b50afc28cc4629f82f5591bef1db2ce129fdc
tree021ac302ac256c4fd3a03b740a0c823e69644b89
parent4bb659b156996f2993dc16fad71fec9ee070153c
blk-mq: fix race in IO start accounting

Commit c6d600c6 opened up a small race where we could attempt to
account IO completion on a request, racing with IO start accounting.
Fix this up by ensuring that we've accounted for IO start before
inserting the request.

Signed-off-by: Jens Axboe <axboe@fb.com>
block/blk-mq.c