Commit 13eec236 authored Apr 12, 2017 by Jan Kara Committed by Jens Axboe Apr 20, 2017

fs: Get proper reference for s_bdi



So far we just relied on block device to hold a bdi reference for us
while the filesystem is mounted. While that works perfectly fine, it is
a bit awkward that we have a pointer to a refcounted structure in the
superblock without proper reference. So make s_bdi hold a proper
reference to block device's BDI. No filesystem using mount_bdev()
actually changes s_bdi so this is safe and will make bdev filesystems
work the same way as filesystems needing to set up their private bdi.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>

parent fca39346

fs/super.c

+2 −5

Original line number	Diff line number	Diff line
		@@ -1054,12 +1054,9 @@ static int set_bdev_super(struct super_block s, void data)
		{
		s->s_bdev = data;
		s->s_dev = s->s_bdev->bd_dev;
		s->s_bdi = bdi_get(s->s_bdev->bd_bdi);
		s->s_iflags \|= SB_I_DYNBDI;

		/*
		* We set the bdi here to the queue backing, file systems can
		* overwrite this in ->fill_super()
		*/
		s->s_bdi = bdev_get_queue(s->s_bdev)->backing_dev_info;
		return 0;
		}