iocost: don't nest spin_lock_irq in ioc_weight_write()
This code causes a static analysis warning:
block/blk-iocost.c:2113 ioc_weight_write() error: double lock 'irq'
We disable IRQs in blkg_conf_prep() and re-enable them in
blkg_conf_finish(). IRQ disable/enable should not be nested because
that means the IRQs will be enabled at the first unlock instead of the
second one.
Fixes: 7caa47151ab2 ("blkcg: implement blk-iocost")
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/block/blk-iocost.c b/block/blk-iocost.c
index 2a3db80..a7ed434 100644
--- a/block/blk-iocost.c
+++ b/block/blk-iocost.c
@@ -2110,10 +2110,10 @@ static ssize_t ioc_weight_write(struct kernfs_open_file *of, char *buf,
goto einval;
}
- spin_lock_irq(&iocg->ioc->lock);
+ spin_lock(&iocg->ioc->lock);
iocg->cfg_weight = v;
weight_updated(iocg);
- spin_unlock_irq(&iocg->ioc->lock);
+ spin_unlock(&iocg->ioc->lock);
blkg_conf_finish(&ctx);
return nbytes;
