[PATCH] blkcg: fix call_kern.cocci warnings

[Julia Lawall]

From: kbuild test robot <fengguang.wu@xxxxxxxxx>

block/blk-cgroup.c:243:57-67: ERROR: function blkg_create called on line 1260 inside lock on line 1259 but uses GFP_KERNEL
block/blk-cgroup.c:243:57-67: ERROR: function blkg_create called on line 922 inside lock on line 911 but uses GFP_KERNEL

Generated by: scripts/coccinelle/locks/call_kern.cocci

Fixes: 6ef69a3a0b4a ("blkcg: change blkg reference counting to use percpu_ref")
CC: Dennis Zhou (Facebook) <dennisszhou@xxxxxxxxx>
Signed-off-by: kbuild test robot <fengguang.wu@xxxxxxxxx>
Signed-off-by: Julia Lawall <julia.lawall@xxxxxxx>
---

url:    https://github.com/0day-ci/linux/commits/Dennis-Zhou/blkcg-ref-count-refactor-cleanup-blkcg-avg_lat/20180831-161742
base:   https://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block.git for-next
:::::: branch date: 10 hours ago
:::::: commit date: 10 hours ago

The kbuild report doesn't include enough context to check this.  Please
check whether this is appropriate and whether another approach would be
better.


 blk-cgroup.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -240,7 +240,7 @@ static struct blkcg_gq *blkg_create(stru
 		blkg_get(blkg->parent);
 	}

-	ret = percpu_ref_init(&blkg->refcnt, __blkg_release, 0, GFP_KERNEL);
+	ret = percpu_ref_init(&blkg->refcnt, __blkg_release, 0, GFP_ATOMIC);
 	if (ret)
 		goto err_cancel_ref;