[PATCH 6/6] block: convert ->bd_inode to container_of()

[Pavel Begunkov <asml.silence@xxxxxxxxx>]

We don't need bdev->bd_inode as we know the layout, they are stored in
the same structure and so offset_of is enough. Convert extra
dereferencing to offseting starting from the block layer.

Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx>
---
 block/fops.c           | 10 ++++++----
 include/linux/blkdev.h | 15 ++++++++++-----
 2 files changed, 16 insertions(+), 9 deletions(-)

diff --git a/block/fops.c b/block/fops.c
index 99e699427f31..5438ed9cfcf7 100644
--- a/block/fops.c
+++ b/block/fops.c
@@ -17,14 +17,16 @@
 #include <linux/fs.h>
 #include "blk.h"
 
-static inline struct inode *bdev_file_inode(struct file *file)
+static inline struct block_device *blkdev_get_bdev(struct file *file)
 {
-	return file->f_mapping->host;
+	return file->private_data;
 }
 
-static inline struct block_device *blkdev_get_bdev(struct file *file)
+static inline struct inode *bdev_file_inode(struct file *file)
 {
-	return file->private_data;
+	struct block_device *bdev = blkdev_get_bdev(file);
+
+	return bdev_get_inode(bdev);
 }
 
 static int blkdev_get_block(struct inode *inode, sector_t iblock,
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 591f14522f78..a56f3a852206 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1139,11 +1139,6 @@ static inline unsigned int blksize_bits(unsigned int size)
 	return bits;
 }
 
-static inline unsigned int block_size(struct block_device *bdev)
-{
-	return 1 << bdev->bd_inode->i_blkbits;
-}
-
 int kblockd_schedule_work(struct work_struct *work);
 int kblockd_mod_delayed_work_on(int cpu, struct delayed_work *dwork, unsigned long delay);
 
@@ -1289,6 +1284,16 @@ static inline struct block_device *I_BDEV(struct inode *inode)
 	return &BDEV_I(inode)->bdev;
 }
 
+static inline struct inode *bdev_get_inode(struct block_device *bdev)
+{
+	return &container_of(bdev, struct bdev_inode, bdev)->vfs_inode;
+}
+
+static inline unsigned int block_size(struct block_device *bdev)
+{
+	return 1 << bdev_get_inode(bdev)->i_blkbits;
+}
+
 #ifdef CONFIG_BLOCK
 void invalidate_bdev(struct block_device *bdev);
 int sync_blockdev(struct block_device *bdev);
-- 
2.33.0