[PATCH block/for-next v2 01/16] block: add a new helper to get inode from block_device

Yu Kuai
2023-11-27T06:21:59Z

From: Yu Kuai <yukuai3@huawei.com>

block_devcie is allocated from bdev_alloc() by bdev_alloc_inode(), and
currently block_device contains a pointer that point to the address of
inode, while such inode is allocated together:

bdev_alloc
inode = new_inode()
// inode is &bdev_inode->vfs_inode
bdev = I_BDEV(inode)
// bdev is &bdev_inode->bdev
bdev->inode = inode

Add a new helper to get address of inode from bdev by add operation
instead of memory access, which is more efficiency.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
---
block/bdev.c | 5 -----
include/linux/blk_types.h | 12 ++++++++++++
2 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/block/bdev.c b/block/bdev.c
index e4cfb7adb645..7509389095b7 100644
--- a/block/bdev.c
+++ b/block/bdev.c
@@ -30,11 +30,6 @@
#include "../fs/internal.h"
#include "blk.h"

-struct bdev_inode {
- struct block_device bdev;
- struct inode vfs_inode;
-};
-
static inline struct bdev_inode *BDEV_I(struct inode *inode)
{
return container_of(inode, struct bdev_inode, vfs_inode);
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index d5c5e59ddbd2..06de8393dcd1 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -85,6 +85,18 @@ struct block_device {
#define bdev_kobj(_bdev) \
(&((_bdev)->bd_device.kobj))

+struct bdev_inode {
+ struct block_device bdev;
+ struct inode vfs_inode;
+};
+
+static inline struct inode *bdev_inode(struct block_device *bdev)
+{
+ struct bdev_inode *bi = container_of(bdev, struct bdev_inode, bdev);
+
+ return &bi->vfs_inode;
+}
+
/*
* Block error status values. See block/blk-core:blk_errors for the details.
* Alpha cannot write a byte atomically, so we need to use 32-bit value.
--
2.39.2