writeback: split writeback_inodes_wb

The case where we have a superblock doesn't require a loop here as we scan
over all inodes in writeback_sb_inodes. Split it out into a separate helper
to make the code simpler.  This also allows to get rid of the sb member in
struct writeback_control, which was rather out of place there.

Also update the comments in writeback_sb_inodes that explain the handling
of inodes from wrong superblocks.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

1 files changed, 0 insertions, 2 deletions

diff --git a/include/linux/writeback.h b/include/linux/writeback.h
index f6756f6a610c..c24eca71e80c 100644
--- a/include/linux/writeback.h
+++ b/include/linux/writeback.h
@@ -27,8 +27,6 @@ enum writeback_sync_modes {
  * in a manner such that unspecified fields are set to zero.
  */
 struct writeback_control {
-        struct super_block *sb;         /* if !NULL, only write inodes from
-                                           this super_block */
         enum writeback_sync_modes sync_mode;
         unsigned long *older_than_this; /* If !NULL, only write back inodes
                                            older than this */