writeback: dirty inodes against their matching cgroup bdi_writeback's

__mark_inode_dirty() always dirtied the inode against the root wb
(bdi_writeback).  The previous patches added all the infrastructure
necessary to attribute an inode against the wb of the dirtying cgroup.

This patch updates __mark_inode_dirty() so that it uses the wb
associated with the inode instead of unconditionally using the root
one.

Currently, none of the filesystems has FS_CGROUP_WRITEBACK and all
pages will keep being dirtied against the root wb.

v2: Updated for per-inode wb association.

Signed-off-by: Tejun Heo <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Jan Kara <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
1 file changed