Re: [PATCH v2 060/110] vfs: change kino_t from unsigned long to u64

Jan Kara <[email protected]> Tue, 3 Mar 2026 12:29:48 +0100
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Message-ID <yfjlanmzvvyuea5qeqnozxtb4ubpkdev3o7ibwmmoo3oczthtu@27zcimxovqjh>
On Mon 02-03-26 15:24:44, Jeff Layton wrote:
> Change kino_t from unsigned long to u64, and update PRIino from "l"
> to "ll" accordingly. This is the actual type widening of i_ino.
> 
> All format strings have already been converted to use PRIino, so this
> change compiles warning-free on both 32-bit and 64-bit architectures.
> 
> On 64-bit architectures, unsigned long is already 64 bits, so this is
> effectively a type alias change with no runtime impact. On 32-bit
> architectures, this widens i_ino from 32 to 64 bits, allowing
> filesystems like NFS, CIFS, XFS, Ceph, and FUSE to store their native
> 64-bit inode numbers without folding/hashing.
> 
> The VFS already handles 64-bit inode numbers in kstat.ino (u64) and
> statx.stx_ino (__u64). The existing overflow checks in cp_new_stat(),
> cp_old_stat(), and cp_compat_stat() handle narrowing to 32-bit st_ino
> with -EOVERFLOW, so userspace ABI is preserved.
> 
> struct inode will grow by 4 bytes on 32-bit architectures.
> 
> Signed-off-by: Jeff Layton <[email protected]>

Looks good. Feel free to add:

Reviewed-by: Jan Kara <[email protected]>

								Honza

> ---
>  include/linux/fs.h | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index d0c4789838b5852111583a3e4cced88999496e68..4193817e02e8bf94f29514ca43379af21f37ac61 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -758,8 +758,8 @@ struct inode_state_flags {
>  	enum inode_state_flags_enum __state;
>  };
>  
> -typedef unsigned long	kino_t;
> -#define PRIino		"l"
> +typedef u64		kino_t;
> +#define PRIino		"ll"
>  
>  /*
>   * Keep mostly read-only and often accessed (especially for
> 
> -- 
> 2.53.0
> 
-- 
Jan Kara <[email protected]>
SUSE Labs, CR