diff mbox series

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

Message ID 20231127062116.2355129-2-yukuai1@huaweicloud.com
State New
Headers show
Series [block/for-next,v2,01/16] block: add a new helper to get inode from block_device | expand

Commit Message

Yu Kuai Nov. 27, 2023, 6:21 a.m. UTC 
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(-)

Comments

'Christoph Hellwig' Nov. 28, 2023, 5:48 a.m. UTC | #1 
On Tue, Nov 28, 2023 at 09:35:56AM +0800, Yu Kuai wrote:
> Thanks for the advice! In case I'm understanding correctly, do you mean
> that all other fs/drivers that is using pages versions can safely switch
> to folio versions now?

If you never allocate a high-order folio pages are identical to folios.
So yes, we can do folio based interfaces only, and also use that as
an opportunity to convert over the callers.

> By the way, my orginal idea was trying to add a new field 'bd_flags'
> in block_devcie, and then add a new bit so that bio_check_ro() will
> only warn once for each partition. Now that this patchset will be quite
> complex, I'll add a new bool field 'bd_ro_warned' to fix the above
> problem first, and then add 'bd_flags' once this patchset is done.

Yes, please do a minimal version if you can find space where the
rmw cycles don't cause damage to neighbouring fields.  Or just leave
the current set of warnings in if it's too hard.
diff mbox series

Patch

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.