bdi: reimplement bdev_inode_switch_bdi()
A block_device may be attached to different gendisks and thus
different bdis over time. bdev_inode_switch_bdi() is used to switch
the associated bdi. The function assumes that the inode could be
dirty and transfers it between bdis if so. This is a bit nasty in
that it reaches into bdi internals.
This patch reimplements the function so that it writes out the inode
if dirty. This is a lot simpler and can be implemented without
exposing bdi internals.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index b65fe93..7d63d5e 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -40,7 +40,7 @@
/* bdi_wq serves all asynchronous writeback tasks */
struct workqueue_struct *bdi_wq;
-void bdi_lock_two(struct bdi_writeback *wb1, struct bdi_writeback *wb2)
+static void bdi_lock_two(struct bdi_writeback *wb1, struct bdi_writeback *wb2)
{
if (wb1 < wb2) {
spin_lock(&wb1->list_lock);