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 <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>

1 files changed, 11 insertions, 12 deletions

diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 59d76f6c9d8d..881ea5d97c00 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -1504,7 +1504,6 @@ static noinline void block_dump___mark_inode_dirty(struct inode *inode)
 void __mark_inode_dirty(struct inode *inode, int flags)
 {
         struct super_block *sb = inode->i_sb;
-        struct backing_dev_info *bdi = NULL;
         int dirtytime;
 
         trace_writeback_mark_inode_dirty(inode, flags);
@@ -1574,30 +1573,30 @@ void __mark_inode_dirty(struct inode *inode, int flags)
                  * reposition it (that would break b_dirty time-ordering).
                  */
                 if (!was_dirty) {
+                        struct bdi_writeback *wb = inode_to_wb(inode);
                         struct list_head *dirty_list;
                         bool wakeup_bdi = false;
-                        bdi = inode_to_bdi(inode);
 
                         spin_unlock(&inode->i_lock);
-                        spin_lock(&bdi->wb.list_lock);
+                        spin_lock(&wb->list_lock);
 
-                        WARN(bdi_cap_writeback_dirty(bdi) &&
-                             !test_bit(WB_registered, &bdi->wb.state),
-                             "bdi-%s not registered\n", bdi->name);
+                        WARN(bdi_cap_writeback_dirty(wb->bdi) &&
+                             !test_bit(WB_registered, &wb->state),
+                             "bdi-%s not registered\n", wb->bdi->name);
 
                         inode->dirtied_when = jiffies;
                         if (dirtytime)
                                 inode->dirtied_time_when = jiffies;
 
                         if (inode->i_state & (I_DIRTY_INODE | I_DIRTY_PAGES))
-                                dirty_list = &bdi->wb.b_dirty;
+                                dirty_list = &wb->b_dirty;
                         else
-                                dirty_list = &bdi->wb.b_dirty_time;
+                                dirty_list = &wb->b_dirty_time;
 
-                        wakeup_bdi = inode_wb_list_move_locked(inode, &bdi->wb,
+                        wakeup_bdi = inode_wb_list_move_locked(inode, wb,
                                                                dirty_list);
 
-                        spin_unlock(&bdi->wb.list_lock);
+                        spin_unlock(&wb->list_lock);
                         trace_writeback_dirty_inode_enqueue(inode);
 
                         /*
@@ -1606,8 +1605,8 @@ void __mark_inode_dirty(struct inode *inode, int flags)
                          * to make sure background write-back happens
                          * later.
                          */
-                        if (bdi_cap_writeback_dirty(bdi) && wakeup_bdi)
-                                wb_wakeup_delayed(&bdi->wb);
+                        if (bdi_cap_writeback_dirty(wb->bdi) && wakeup_bdi)
+                                wb_wakeup_delayed(wb);
                         return;
                 }
         }