[BLOCK] elevator init fixes
I got a panic in the elevator code, backtrace :
Unable to handle kernel NULL pointer dereference at virtual address 00000060
..
EIP is at elevator_put+0x0/0x30 (null elevator_type passed)
..
elevator_init+0x38
blk_init_queu_node+0xc9
floppy_init+0xdb
do_initcalls+0x23
init+0x10a
init+0x0
Clearly if the kmalloc here fails, e->elevator_type is not yet set; this
appears to be the correct fix, but I think I probably hit the second case
due to a race condition. Someone more familiar with the elevator code
should look at this more closely until I can determine if I can reproduce.
Signed-off-by: Zachary Amsden <zach@vmware.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Jens Axboe <axboe@suse.de>
diff --git a/block/elevator.c b/block/elevator.c
index d4a49a3..23cfbe5 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -190,14 +190,14 @@
eq = kmalloc(sizeof(struct elevator_queue), GFP_KERNEL);
if (!eq) {
- elevator_put(e->elevator_type);
+ elevator_put(e);
return -ENOMEM;
}
ret = elevator_attach(q, e, eq);
if (ret) {
kfree(eq);
- elevator_put(e->elevator_type);
+ elevator_put(e);
}
return ret;