mm: don't include <linux/blkdev.h> in <linux/backing-dev.h>

Move inode_to_bdi out of line to avoid having to include blkdev.h.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20210920123328.1399408-4-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

drivers/mtd/mtdsuper.c

@@ -15,6 +15,7 @@
 #include <linux/slab.h>
 #include <linux/major.h>
 #include <linux/backing-dev.h>
+#include <linux/blkdev.h>
 #include <linux/fs_context.h>
 #include "mtdcore.h"
 

fs/ntfs/file.c

@@ -5,6 +5,7 @@
  * Copyright (c) 2001-2015 Anton Altaparmakov and Tuxera Inc.
  */
 
+#include <linux/blkdev.h>
 #include <linux/backing-dev.h>
 #include <linux/buffer_head.h>
 #include <linux/gfp.h>

fs/ntfs3/file.c

@@ -8,6 +8,7 @@
  */
 
 #include <linux/backing-dev.h>
+#include <linux/blkdev.h>
 #include <linux/buffer_head.h>
 #include <linux/compat.h>
 #include <linux/falloc.h>

fs/orangefs/inode.c

@@ -10,7 +10,7 @@
  *  Linux VFS inode operations.
  */
 
-#include <linux/bvec.h>
+#include <linux/blkdev.h>
 #include <linux/fileattr.h>
 #include "protocol.h"
 #include "orangefs-kernel.h"

include/linux/backing-dev.h

@@ -12,7 +12,6 @@
 #include <linux/kernel.h>
 #include <linux/fs.h>
 #include <linux/sched.h>
-#include <linux/blkdev.h>
 #include <linux/device.h>
 #include <linux/writeback.h>
 #include <linux/backing-dev-defs.h>
@@ -134,20 +133,7 @@ static inline bool writeback_in_progress(struct bdi_writeback *wb)
 	return test_bit(WB_writeback_running, &wb->state);
 }
 
-static inline struct backing_dev_info *inode_to_bdi(struct inode *inode)
-{
-	struct super_block *sb;
-
-	if (!inode)
-		return &noop_backing_dev_info;
-
-	sb = inode->i_sb;
-#ifdef CONFIG_BLOCK
-	if (sb_is_blkdev_sb(sb))
-		return I_BDEV(inode)->bd_disk->bdi;
-#endif
-	return sb->s_bdi;
-}
+struct backing_dev_info *inode_to_bdi(struct inode *inode);
 
 static inline int wb_congested(struct bdi_writeback *wb, int cong_bits)
 {

mm/backing-dev.c

@@ -978,6 +978,22 @@ void bdi_put(struct backing_dev_info *bdi)
 }
 EXPORT_SYMBOL(bdi_put);
 
+struct backing_dev_info *inode_to_bdi(struct inode *inode)
+{
+	struct super_block *sb;
+
+	if (!inode)
+		return &noop_backing_dev_info;
+
+	sb = inode->i_sb;
+#ifdef CONFIG_BLOCK
+	if (sb_is_blkdev_sb(sb))
+		return I_BDEV(inode)->bd_disk->bdi;
+#endif
+	return sb->s_bdi;
+}
+EXPORT_SYMBOL(inode_to_bdi);
+
 const char *bdi_dev_name(struct backing_dev_info *bdi)
 {
 	if (!bdi || !bdi->dev)