tree 001dfc1147a64bd05798e29b15ce5d995486a6fa
parent 64565911cdb57c2f512a9715b985b5617402cc67
author Jens Axboe <jens.axboe@oracle.com> 1211978819 +0200
committer Jens Axboe <jens.axboe@oracle.com> 1211978968 +0200

cfq-iosched: fix RCU problem in cfq_cic_lookup()

cfq_cic_lookup() needs to properly protect ioc->ioc_data before
dereferencing it and also exclude updaters of ioc->ioc_data as well.

Also add a number of comments documenting why the existing RCU usage
is OK.

Thanks a lot to "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> for
review and comments!

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>