From e164094964e6e20fe7fce418e06a9dce952bb7a4 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Tue, 19 Feb 2008 10:20:37 +0100 Subject: elevator: make elevator_get() attempt to load the appropriate module Currently we fail if someone requests a valid io scheduler, but it's modular and not currently loaded. That can happen from a driver init asking for a different scheduler, or online switching through sysfs as requested by a user. This patch makes elevator_get() request_module() to attempt to load the appropriate module, instead of requiring that done manually. Signed-off-by: Jens Axboe --- block/elevator.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/block/elevator.c b/block/elevator.c index bafbae0344d..88318c38360 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -134,6 +134,21 @@ static struct elevator_type *elevator_get(const char *name) spin_lock(&elv_list_lock); e = elevator_find(name); + if (!e) { + char elv[ELV_NAME_MAX + strlen("-iosched")]; + + spin_unlock(&elv_list_lock); + + if (!strcmp(name, "anticipatory")) + sprintf(elv, "as-iosched"); + else + sprintf(elv, "%s-iosched", name); + + request_module(elv); + spin_lock(&elv_list_lock); + e = elevator_find(name); + } + if (e && !try_module_get(e->elevator_owner)) e = NULL; -- cgit v1.2.3