writeback: send work item to queue_io, move_expired_inodes

Instead of sending ->older_than_this to queue_io() and
move_expired_inodes(), send the entire wb_writeback_work
structure.  There are other fields of a work item that are
useful in these routines and in tracepoints.

Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Curt Wohlgemuth <curtw@google.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>

2 files changed, 11 insertions, 10 deletions

diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 6401cd76f109..c51029693600 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -251,7 +251,7 @@ static bool inode_dirtied_after(struct inode *inode, unsigned long t)
  */
 static int move_expired_inodes(struct list_head *delaying_queue,
                                struct list_head *dispatch_queue,
-                               unsigned long *older_than_this)
+                               struct wb_writeback_work *work)
 {
         LIST_HEAD(tmp);
         struct list_head *pos, *node;
@@ -262,8 +262,8 @@ static int move_expired_inodes(struct list_head *delaying_queue,
 
         while (!list_empty(delaying_queue)) {
                 inode = wb_inode(delaying_queue->prev);
-                if (older_than_this &&
-                    inode_dirtied_after(inode, *older_than_this))
+                if (work->older_than_this &&
+                    inode_dirtied_after(inode, *work->older_than_this))
                         break;
                 if (sb && sb != inode->i_sb)
                         do_sb_sort = 1;
@@ -302,13 +302,13 @@ out:
  *                                           |
  *                                           +--> dequeue for IO
  */
-static void queue_io(struct bdi_writeback *wb, unsigned long *older_than_this)
+static void queue_io(struct bdi_writeback *wb, struct wb_writeback_work *work)
 {
         int moved;
         assert_spin_locked(&wb->list_lock);
         list_splice_init(&wb->b_more_io, &wb->b_io);
-        moved = move_expired_inodes(&wb->b_dirty, &wb->b_io, older_than_this);
-        trace_writeback_queue_io(wb, older_than_this, moved);
+        moved = move_expired_inodes(&wb->b_dirty, &wb->b_io, work);
+        trace_writeback_queue_io(wb, work, moved);
 }
 
 static int write_inode(struct inode *inode, struct writeback_control *wbc)
@@ -651,7 +651,7 @@ long writeback_inodes_wb(struct bdi_writeback *wb, long nr_pages)
 
         spin_lock(&wb->list_lock);
         if (list_empty(&wb->b_io))
-                queue_io(wb, NULL);
+                queue_io(wb, &work);
         __writeback_inodes_wb(wb, &work);
         spin_unlock(&wb->list_lock);
 
@@ -745,7 +745,7 @@ static long wb_writeback(struct bdi_writeback *wb,
 
                 trace_writeback_start(wb->bdi, work);
                 if (list_empty(&wb->b_io))
-                        queue_io(wb, work->older_than_this);
+                        queue_io(wb, work);
                 if (work->sb)
                         progress = writeback_sb_inodes(work->sb, wb, work);
                 else
diff --git a/include/trace/events/writeback.h b/include/trace/events/writeback.h
index 0ce9f06f58c2..1261db3916cc 100644
--- a/include/trace/events/writeback.h
+++ b/include/trace/events/writeback.h
@@ -157,9 +157,9 @@ DEFINE_WBC_EVENT(wbc_writepage);
 
 TRACE_EVENT(writeback_queue_io,
         TP_PROTO(struct bdi_writeback *wb,
-                 unsigned long *older_than_this,
+                 struct wb_writeback_work *work,
                  int moved),
-        TP_ARGS(wb, older_than_this, moved),
+        TP_ARGS(wb, work, moved),
         TP_STRUCT__entry(
                 __array(char,           name, 32)
                 __field(unsigned long,  older)
@@ -167,6 +167,7 @@ TRACE_EVENT(writeback_queue_io,
                 __field(int,            moved)
         ),
         TP_fast_assign(
+                unsigned long *older_than_this = work->older_than_this;
                 strncpy(__entry->name, dev_name(wb->bdi->dev), 32);
                 __entry->older  = older_than_this ?  *older_than_this : 0;
                 __entry->age    = older_than_this ?