Re: [PATCH] btrfs: remove 32bit compat code for VFS inode number

[Qu Wenruo <wqu@suse.com>]

在 2026/4/15 05:42, David Sterba 写道:
> Commit 0b2600f81cefcd ("treewide: change inode->i_ino from unsigned long
> to u64") sets the inode number type to u64 unconditionally, so we can
> use it directly as there's no difference on 32bit and 64bit platform. We
> used to have a copy of the number in our btrfs_inode.
> 
> The size of btrfs_inode on 32bit platform is about 688 bytes (after the
> change).
> 
> Signed-off-by: David Sterba <dsterba@suse.com>

Reviewed-by: Qu Wenruo <wqu@suse.com>

But that treewide patch is not yet in our for-next, we can only merge it 
after our for-next is rebased.

Thanks,
Qu

> ---
>   fs/btrfs/btrfs_inode.h | 31 -------------------------------
>   fs/btrfs/verity.c      |  4 ++--
>   2 files changed, 2 insertions(+), 33 deletions(-)
> 
> diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h
> index 55c272fe5d92a0..3481c91fec7cfb 100644
> --- a/fs/btrfs/btrfs_inode.h
> +++ b/fs/btrfs/btrfs_inode.h
> @@ -128,15 +128,6 @@ struct btrfs_inode {
>   	/* which subvolume this inode belongs to */
>   	struct btrfs_root *root;
>   
> -#if BITS_PER_LONG == 32
> -	/*
> -	 * The objectid of the corresponding BTRFS_INODE_ITEM_KEY.
> -	 * On 64 bits platforms we can get it from vfs_inode.i_ino, which is an
> -	 * unsigned long and therefore 64 bits on such platforms.
> -	 */
> -	u64 objectid;
> -#endif
> -
>   	/* Cached value of inode property 'compression'. */
>   	u8 prop_compress;
>   
> @@ -372,30 +363,11 @@ static inline unsigned long btrfs_inode_hash(u64 objectid,
>   	return (unsigned long)h;
>   }
>   
> -#if BITS_PER_LONG == 32
> -
> -/*
> - * On 32 bit systems the i_ino of struct inode is 32 bits (unsigned long), so
> - * we use the inode's location objectid which is a u64 to avoid truncation.
> - */
> -static inline u64 btrfs_ino(const struct btrfs_inode *inode)
> -{
> -	u64 ino = inode->objectid;
> -
> -	if (test_bit(BTRFS_INODE_ROOT_STUB, &inode->runtime_flags))
> -		ino = inode->vfs_inode.i_ino;
> -	return ino;
> -}
> -
> -#else
> -
>   static inline u64 btrfs_ino(const struct btrfs_inode *inode)
>   {
>   	return inode->vfs_inode.i_ino;
>   }
>   
> -#endif
> -
>   static inline void btrfs_get_inode_key(const struct btrfs_inode *inode,
>   				       struct btrfs_key *key)
>   {
> @@ -406,9 +378,6 @@ static inline void btrfs_get_inode_key(const struct btrfs_inode *inode,
>   
>   static inline void btrfs_set_inode_number(struct btrfs_inode *inode, u64 ino)
>   {
> -#if BITS_PER_LONG == 32
> -	inode->objectid = ino;
> -#endif
>   	inode->vfs_inode.i_ino = ino;
>   }
>   
> diff --git a/fs/btrfs/verity.c b/fs/btrfs/verity.c
> index 0062b3a5578199..983365a7354168 100644
> --- a/fs/btrfs/verity.c
> +++ b/fs/btrfs/verity.c
> @@ -458,7 +458,7 @@ static int rollback_verity(struct btrfs_inode *inode)
>   	if (ret) {
>   		btrfs_handle_fs_error(root->fs_info, ret,
>   				"failed to drop verity items in rollback %llu",
> -				(u64)inode->vfs_inode.i_ino);
> +				inode->vfs_inode.i_ino);
>   		goto out;
>   	}
>   
> @@ -472,7 +472,7 @@ static int rollback_verity(struct btrfs_inode *inode)
>   		trans = NULL;
>   		btrfs_handle_fs_error(root->fs_info, ret,
>   			"failed to start transaction in verity rollback %llu",
> -			(u64)inode->vfs_inode.i_ino);
> +			inode->vfs_inode.i_ino);
>   		goto out;
>   	}
>   	inode->ro_flags &= ~BTRFS_INODE_RO_VERITY;