writeback: remove writeback_control.more_io

When wbc.more_io was first introduced, it indicates whether there are
at least one superblock whose s_more_io contains more IO work. Now with
the per-bdi writeback, it can be replaced with a simple b_more_io test.

Acked-by: Jan Kara <jack@suse.cz>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>

1 files changed, 2 insertions, 7 deletions

diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index d0553f33fb50..f43c479feee9 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -560,12 +560,8 @@ static int writeback_sb_inodes(struct super_block *sb, struct bdi_writeback *wb,
                 iput(inode);
                 cond_resched();
                 spin_lock(&wb->list_lock);
-                if (wbc->nr_to_write <= 0) {
-                        wbc->more_io = 1;
+                if (wbc->nr_to_write <= 0)
                         return 1;
-                }
-                if (!list_empty(&wb->b_more_io))
-                        wbc->more_io = 1;
         }
         /* b_io is empty */
         return 1;
@@ -708,7 +704,6 @@ static long wb_writeback(struct bdi_writeback *wb,
                         wbc.older_than_this = &oldest_jif;
                 }
 
-                wbc.more_io = 0;
                 wbc.nr_to_write = write_chunk;
                 wbc.pages_skipped = 0;
                 wbc.inodes_written = 0;
@@ -740,7 +735,7 @@ static long wb_writeback(struct bdi_writeback *wb,
                 /*
                  * No more inodes for IO, bail
                  */
-                if (!wbc.more_io)
+                if (list_empty(&wb->b_more_io))
                         break;
                 /*
                  * Nothing written. Wait for some inode to