Commit 2d8f6131 authored by Oleg Nesterov's avatar Oleg Nesterov Committed by Greg Kroah-Hartman
Browse files

elv_unregister: fix possible crash on module unload 



An exiting task or process which didn't do I/O yet have no io context,
elv_unregister() should check it is not NULL.

Signed-off-by: default avatarOleg Nesterov <oleg@tv-sign.ru>
Acked-by: default avatarJens Axboe <axboe@suse.de>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 00a2b0f6

block/elevator.c

+2 −1
Original line number Diff line number Diff line
@@ -765,6 +765,7 @@ void elv_unregister(struct elevator_type *e) 
		read_lock(&tasklist_lock);

		do_each_thread(g, p) {

			task_lock(p);

			if (p->io_context)

				e->ops.trim(p->io_context);

			task_unlock(p);

		} while_each_thread(g, p);