Re: [PATCH 4/5] exportfs: define FILEID_INO64_GEN* file handle types

[Jeff Layton <jlayton@kernel.org>]

On Wed, 2023-10-18 at 12:59 +0300, Amir Goldstein wrote:
> Similar to the common FILEID_INO32* file handle types, define common
> FILEID_INO64* file handle types.
> 
> The type values of FILEID_INO64_GEN and FILEID_INO64_GEN_PARENT are the
> values returned by fuse and xfs for 64bit ino encoded file handle types.
> 
> Note that these type value are filesystem specific and they do not define
> a universal file handle format, for example:
> fuse encodes FILEID_INO64_GEN as [ino-hi32,ino-lo32,gen] and xfs encodes
> FILEID_INO64_GEN as [hostr-order-ino64,gen] (a.k.a xfs_fid64).
> 
> The FILEID_INO64_GEN fhandle type is going to be used for file ids for
> fanotify from filesystems that do not support NFS export.
> 
> Signed-off-by: Amir Goldstein <amir73il@gmail.com>
> ---
>  fs/fuse/inode.c          |  7 ++++---
>  include/linux/exportfs.h | 11 +++++++++++
>  2 files changed, 15 insertions(+), 3 deletions(-)
> 
> diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
> index 2e4eb7cf26fb..e63f966698a5 100644
> --- a/fs/fuse/inode.c
> +++ b/fs/fuse/inode.c
> @@ -1002,7 +1002,7 @@ static int fuse_encode_fh(struct inode *inode, u32 *fh, int *max_len,
>  	}
>  
>  	*max_len = len;
> -	return parent ? 0x82 : 0x81;
> +	return parent ? FILEID_INO64_GEN_PARENT : FILEID_INO64_GEN;
>  }
>  
>  static struct dentry *fuse_fh_to_dentry(struct super_block *sb,
> @@ -1010,7 +1010,8 @@ static struct dentry *fuse_fh_to_dentry(struct super_block *sb,
>  {
>  	struct fuse_inode_handle handle;
>  
> -	if ((fh_type != 0x81 && fh_type != 0x82) || fh_len < 3)
> +	if ((fh_type != FILEID_INO64_GEN &&
> +	     fh_type != FILEID_INO64_GEN_PARENT) || fh_len < 3)
>  		return NULL;
>  
>  	handle.nodeid = (u64) fid->raw[0] << 32;
> @@ -1024,7 +1025,7 @@ static struct dentry *fuse_fh_to_parent(struct super_block *sb,
>  {
>  	struct fuse_inode_handle parent;
>  
> -	if (fh_type != 0x82 || fh_len < 6)
> +	if (fh_type != FILEID_INO64_GEN_PARENT || fh_len < 6)
>  		return NULL;
>  
>  	parent.nodeid = (u64) fid->raw[3] << 32;
> diff --git a/include/linux/exportfs.h b/include/linux/exportfs.h
> index 6b6e01321405..21eeb9f6bdbd 100644
> --- a/include/linux/exportfs.h
> +++ b/include/linux/exportfs.h
> @@ -98,6 +98,17 @@ enum fid_type {
>  	 */
>  	FILEID_FAT_WITH_PARENT = 0x72,
>  
> +	/*
> +	 * 64 bit inode number, 32 bit generation number.
> +	 */
> +	FILEID_INO64_GEN = 0x81,
> +
> +	/*
> +	 * 64 bit inode number, 32 bit generation number,
> +	 * 64 bit parent inode number, 32 bit parent generation.
> +	 */
> +	FILEID_INO64_GEN_PARENT = 0x82,
> +
>  	/*
>  	 * 128 bit child FID (struct lu_fid)
>  	 * 128 bit parent FID (struct lu_fid)

Reviewed-by: Jeff Layton <jlayton@kernel.org>