dm btree: silence lockdep lock inversion in dm_btree_del()

Allocate memory using GFP_NOIO when deleting a btree.  dm_btree_del()
can be called via an ioctl and we don't want to recurse into the FS or
block layer.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org

diff --git a/drivers/md/persistent-data/dm-btree.c b/drivers/md/persistent-data/dm-btree.c
index 200ac12..fdd3793 100644 (file)
--- a/drivers/md/persistent-data/dm-btree.c
+++ b/drivers/md/persistent-data/dm-btree.c
@@ -255,7 +255,7 @@ int dm_btree_del(struct dm_btree_info *info, dm_block_t root)
        int r;
        struct del_stack *s;
 
-       s = kmalloc(sizeof(*s), GFP_KERNEL);
+       s = kmalloc(sizeof(*s), GFP_NOIO);
        if (!s)
                return -ENOMEM;
        s->info = info;