writeback: separate out include/linux/backing-dev-defs.h With the planned cgroup writeback support, backing-dev related declarations will be more widely used across block and cgroup; unfortunately, including backing-dev.h from include/linux/blkdev.h makes cyclic include dependency quite likely. This patch separates out backing-dev-defs.h which only has the essential definitions and updates blkdev.h to include it. c files which need access to more backing-dev details now include backing-dev.h directly. This takes backing-dev.h off the common include dependency chain making it a lot easier to use it across block and cgroup. v2: fs/fat build failure fixed. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 8d1e602..440987c 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c
@@ -26,6 +26,7 @@ #include <linux/log2.h> #include <linux/module.h> #include <linux/slab.h> +#include <linux/backing-dev.h> #include <trace/events/ext4.h> #ifdef CONFIG_EXT4_DEBUG