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 <h...@lst.de> Signed-off-by: Jan Kara <j...@suse.cz> --- fs/super.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/fs/super.c b/fs/super.c index 0f51a437c269..e267d3a00144 100644 --- a/fs/super.c +++ b/fs/super.c @@ -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; } -- 2.12.0