writeback: remove writeback_inodes_wbc

This was just an odd wrapper around writeback_inodes_wb.  Removing this
also allows to get rid of the bdi member of struct writeback_control
which was rather out of place there.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

fs/afs/write.c

@@ -680,7 +680,6 @@ int afs_writeback_all(struct afs_vnode *vnode)
 {
 	struct address_space *mapping = vnode->vfs_inode.i_mapping;
 	struct writeback_control wbc = {
-		.bdi		= mapping->backing_dev_info,
 		.sync_mode	= WB_SYNC_ALL,
 		.nr_to_write	= LONG_MAX,
 		.range_cyclic	= 1,

fs/btrfs/extent_io.c

@@ -2594,7 +2594,6 @@ int extent_write_full_page(struct extent_io_tree *tree, struct page *page,
 		.sync_io = wbc->sync_mode == WB_SYNC_ALL,
 	};
 	struct writeback_control wbc_writepages = {
-		.bdi		= wbc->bdi,
 		.sync_mode	= wbc->sync_mode,
 		.older_than_this = NULL,
 		.nr_to_write	= 64,
@@ -2628,7 +2627,6 @@ int extent_write_locked_range(struct extent_io_tree *tree, struct inode *inode,
 		.sync_io = mode == WB_SYNC_ALL,
 	};
 	struct writeback_control wbc_writepages = {
-		.bdi		= inode->i_mapping->backing_dev_info,
 		.sync_mode	= mode,
 		.older_than_this = NULL,
 		.nr_to_write	= nr_pages * 2,

fs/fs-writeback.c

@@ -614,8 +614,8 @@ static int writeback_sb_inodes(struct super_block *sb,
 	return 1;
 }
 
-static void writeback_inodes_wb(struct bdi_writeback *wb,
-				struct writeback_control *wbc)
+void writeback_inodes_wb(struct bdi_writeback *wb,
+		struct writeback_control *wbc)
 {
 	int ret = 0;
 
@@ -660,13 +660,6 @@ static void writeback_inodes_wb(struct bdi_writeback *wb,
 	/* Leave any unwritten inodes on b_io */
 }
 
-void writeback_inodes_wbc(struct writeback_control *wbc)
-{
-	struct backing_dev_info *bdi = wbc->bdi;
-
-	writeback_inodes_wb(&bdi->wb, wbc);
-}
-
 /*
  * The maximum number of pages to writeout in a single bdi flush/kupdate
  * operation.  We do this so we don't hold I_SYNC against an inode for
@@ -705,7 +698,6 @@ static long wb_writeback(struct bdi_writeback *wb,
 			 struct wb_writeback_args *args)
 {
 	struct writeback_control wbc = {
-		.bdi			= wb->bdi,
 		.sb			= args->sb,
 		.sync_mode		= args->sync_mode,
 		.older_than_this	= NULL,

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 backing_dev_info *bdi;	/* If !NULL, only write back this
-					   queue */
 	struct super_block *sb;		/* if !NULL, only write inodes from
 					   this super_block */
 	enum writeback_sync_modes sync_mode;
@@ -66,7 +64,8 @@ int inode_wait(void *);
 void writeback_inodes_sb(struct super_block *);
 int writeback_inodes_sb_if_idle(struct super_block *);
 void sync_inodes_sb(struct super_block *);
-void writeback_inodes_wbc(struct writeback_control *wbc);
+void writeback_inodes_wb(struct bdi_writeback *wb,
+		struct writeback_control *wbc);
 long wb_do_writeback(struct bdi_writeback *wb, int force_wait);
 void wakeup_flusher_threads(long nr_pages);
 

mm/backing-dev.c

@@ -340,14 +340,13 @@ int bdi_has_dirty_io(struct backing_dev_info *bdi)
 static void bdi_flush_io(struct backing_dev_info *bdi)
 {
 	struct writeback_control wbc = {
-		.bdi			= bdi,
 		.sync_mode		= WB_SYNC_NONE,
 		.older_than_this	= NULL,
 		.range_cyclic		= 1,
 		.nr_to_write		= 1024,
 	};
 
-	writeback_inodes_wbc(&wbc);
+	writeback_inodes_wb(&bdi->wb, &wbc);
 }
 
 /*

mm/page-writeback.c

@@ -495,7 +495,6 @@ static void balance_dirty_pages(struct address_space *mapping,
 
 	for (;;) {
 		struct writeback_control wbc = {
-			.bdi		= bdi,
 			.sync_mode	= WB_SYNC_NONE,
 			.older_than_this = NULL,
 			.nr_to_write	= write_chunk,
@@ -537,7 +536,7 @@ static void balance_dirty_pages(struct address_space *mapping,
 		 * up.
 		 */
 		if (bdi_nr_reclaimable > bdi_thresh) {
-			writeback_inodes_wbc(&wbc);
+			writeback_inodes_wb(&bdi->wb, &wbc);
 			pages_written += write_chunk - wbc.nr_to_write;
 			get_dirty_limits(&background_thresh, &dirty_thresh,
 				       &bdi_thresh, bdi);