On Wed, Oct 18, 2023 at 12:59:58PM +0300, Amir Goldstein wrote:
> export_operations ->encode_fh() no longer has a default implementation to
> encode FILEID_INO32_GEN* file handles.
>
> Rename the default helper for encoding FILEID_INO32_GEN* file handles to
> generic_encode_ino32_fh() and convert the filesystems that used the
> default implementation to use the generic helper explicitly.
>
> This is a step towards allowing filesystems to encode non-decodeable file
> handles for fanotify without having to implement any export_operations.
>
> Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx>
> ---
> Documentation/filesystems/nfs/exporting.rst | 7 ++-----
> Documentation/filesystems/porting.rst | 9 +++++++++
> fs/affs/namei.c | 1 +
> fs/befs/linuxvfs.c | 1 +
> fs/efs/super.c | 1 +
> fs/erofs/super.c | 1 +
> fs/exportfs/expfs.c | 14 ++++++++------
> fs/ext2/super.c | 1 +
> fs/ext4/super.c | 1 +
> fs/f2fs/super.c | 1 +
> fs/fat/nfs.c | 1 +
> fs/jffs2/super.c | 1 +
> fs/jfs/super.c | 1 +
> fs/ntfs/namei.c | 1 +
> fs/ntfs3/super.c | 1 +
> fs/smb/client/export.c | 9 +++------
> fs/squashfs/export.c | 1 +
> fs/ufs/super.c | 1 +
> include/linux/exportfs.h | 4 +++-
> 19 files changed, 39 insertions(+), 18 deletions(-)
>
> diff --git a/Documentation/filesystems/nfs/exporting.rst b/Documentation/filesystems/nfs/exporting.rst
> index 4b30daee399a..de64d2d002a2 100644
> --- a/Documentation/filesystems/nfs/exporting.rst
> +++ b/Documentation/filesystems/nfs/exporting.rst
> @@ -122,12 +122,9 @@ are exportable by setting the s_export_op field in the struct
> super_block. This field must point to a "struct export_operations"
> struct which has the following members:
>
> - encode_fh (optional)
> + encode_fh (mandatory)
> Takes a dentry and creates a filehandle fragment which may later be used
> - to find or create a dentry for the same object. The default
> - implementation creates a filehandle fragment that encodes a 32bit inode
> - and generation number for the inode encoded, and if necessary the
> - same information for the parent.
> + to find or create a dentry for the same object.
>
> fh_to_dentry (mandatory)
> Given a filehandle fragment, this should find the implied object and
> diff --git a/Documentation/filesystems/porting.rst b/Documentation/filesystems/porting.rst
> index 4d05b9862451..197ef78a5014 100644
> --- a/Documentation/filesystems/porting.rst
> +++ b/Documentation/filesystems/porting.rst
> @@ -1045,3 +1045,12 @@ filesystem type is now moved to a later point when the devices are closed:
> As this is a VFS level change it has no practical consequences for filesystems
> other than that all of them must use one of the provided kill_litter_super(),
> kill_anon_super(), or kill_block_super() helpers.
> +
> +---
> +
> +**mandatory**
> +
> +export_operations ->encode_fh() no longer has a default implementation to
> +encode FILEID_INO32_GEN* file handles.
> +Fillesystems that used the default implementation may use the generic helper
> +generic_encode_ino32_fh() explicitly.
> diff --git a/fs/affs/namei.c b/fs/affs/namei.c
> index 2fe4a5832fcf..d6b9758ee23d 100644
> --- a/fs/affs/namei.c
> +++ b/fs/affs/namei.c
> @@ -568,6 +568,7 @@ static struct dentry *affs_fh_to_parent(struct super_block *sb, struct fid *fid,
> }
>
> const struct export_operations affs_export_ops = {
> + .encode_fh = generic_encode_ino32_fh,
> .fh_to_dentry = affs_fh_to_dentry,
> .fh_to_parent = affs_fh_to_parent,
> .get_parent = affs_get_parent,
> diff --git a/fs/befs/linuxvfs.c b/fs/befs/linuxvfs.c
> index 9a16a51fbb88..410dcaffd5ab 100644
> --- a/fs/befs/linuxvfs.c
> +++ b/fs/befs/linuxvfs.c
> @@ -96,6 +96,7 @@ static const struct address_space_operations befs_symlink_aops = {
> };
>
> static const struct export_operations befs_export_operations = {
> + .encode_fh = generic_encode_ino32_fh,
> .fh_to_dentry = befs_fh_to_dentry,
> .fh_to_parent = befs_fh_to_parent,
> .get_parent = befs_get_parent,
> diff --git a/fs/efs/super.c b/fs/efs/super.c
> index b287f47c165b..f17fdac76b2e 100644
> --- a/fs/efs/super.c
> +++ b/fs/efs/super.c
> @@ -123,6 +123,7 @@ static const struct super_operations efs_superblock_operations = {
> };
>
> static const struct export_operations efs_export_ops = {
> + .encode_fh = generic_encode_ino32_fh,
> .fh_to_dentry = efs_fh_to_dentry,
> .fh_to_parent = efs_fh_to_parent,
> .get_parent = efs_get_parent,
> diff --git a/fs/erofs/super.c b/fs/erofs/super.c
> index 3700af9ee173..edbe07a24156 100644
> --- a/fs/erofs/super.c
> +++ b/fs/erofs/super.c
> @@ -626,6 +626,7 @@ static struct dentry *erofs_get_parent(struct dentry *child)
> }
>
> static const struct export_operations erofs_export_ops = {
> + .encode_fh = generic_encode_ino32_fh,
> .fh_to_dentry = erofs_fh_to_dentry,
> .fh_to_parent = erofs_fh_to_parent,
> .get_parent = erofs_get_parent,
> diff --git a/fs/exportfs/expfs.c b/fs/exportfs/expfs.c
> index 9ee205df8fa7..30da4539e257 100644
> --- a/fs/exportfs/expfs.c
> +++ b/fs/exportfs/expfs.c
> @@ -343,20 +343,21 @@ static int get_name(const struct path *path, char *name, struct dentry *child)
> }
>
> /**
> - * export_encode_fh - default export_operations->encode_fh function
> + * generic_encode_ino32_fh - generic export_operations->encode_fh function
> * @inode: the object to encode
> - * @fid: where to store the file handle fragment
> + * @fh: where to store the file handle fragment
> * @max_len: maximum length to store there
> * @parent: parent directory inode, if wanted
> *
> - * This default encode_fh function assumes that the 32 inode number
> + * This generic encode_fh function assumes that the 32 inode number
> * is suitable for locating an inode, and that the generation number
> * can be used to check that it is still valid. It places them in the
> * filehandle fragment where export_decode_fh expects to find them.
> */
> -static int export_encode_fh(struct inode *inode, struct fid *fid,
> - int *max_len, struct inode *parent)
> +int generic_encode_ino32_fh(struct inode *inode, __u32 *fh, int *max_len,
> + struct inode *parent)
> {
> + struct fid *fid = (void *)fh;
> int len = *max_len;
> int type = FILEID_INO32_GEN;
>
> @@ -380,6 +381,7 @@ static int export_encode_fh(struct inode *inode, struct fid *fid,
> *max_len = len;
> return type;
> }
> +EXPORT_SYMBOL_GPL(generic_encode_ino32_fh);
>
> /**
> * exportfs_encode_inode_fh - encode a file handle from inode
> @@ -402,7 +404,7 @@ int exportfs_encode_inode_fh(struct inode *inode, struct fid *fid,
> if (nop && nop->encode_fh)
> return nop->encode_fh(inode, fid->raw, max_len, parent);
>
> - return export_encode_fh(inode, fid, max_len, parent);
> + return -EOPNOTSUPP;
> }
> EXPORT_SYMBOL_GPL(exportfs_encode_inode_fh);
>
> diff --git a/fs/ext2/super.c b/fs/ext2/super.c
> index aaf3e3e88cb2..b9f158a34997 100644
> --- a/fs/ext2/super.c
> +++ b/fs/ext2/super.c
> @@ -397,6 +397,7 @@ static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
> }
>
> static const struct export_operations ext2_export_ops = {
> + .encode_fh = generic_encode_ino32_fh,
> .fh_to_dentry = ext2_fh_to_dentry,
> .fh_to_parent = ext2_fh_to_parent,
> .get_parent = ext2_get_parent,
> diff --git a/fs/ext4/super.c b/fs/ext4/super.c
> index dbebd8b3127e..c44db1915437 100644
> --- a/fs/ext4/super.c
> +++ b/fs/ext4/super.c
> @@ -1646,6 +1646,7 @@ static const struct super_operations ext4_sops = {
> };
>
> static const struct export_operations ext4_export_ops = {
> + .encode_fh = generic_encode_ino32_fh,
> .fh_to_dentry = ext4_fh_to_dentry,
> .fh_to_parent = ext4_fh_to_parent,
> .get_parent = ext4_get_parent,
> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> index a8c8232852bb..60cfa11f65bf 100644
> --- a/fs/f2fs/super.c
> +++ b/fs/f2fs/super.c
> @@ -3282,6 +3282,7 @@ static struct dentry *f2fs_fh_to_parent(struct super_block *sb, struct fid *fid,
> }
>
> static const struct export_operations f2fs_export_ops = {
> + .encode_fh = generic_encode_ino32_fh,
> .fh_to_dentry = f2fs_fh_to_dentry,
> .fh_to_parent = f2fs_fh_to_parent,
> .get_parent = f2fs_get_parent,
> diff --git a/fs/fat/nfs.c b/fs/fat/nfs.c
> index 3626eb585a98..c52e63e10d35 100644
> --- a/fs/fat/nfs.c
> +++ b/fs/fat/nfs.c
> @@ -279,6 +279,7 @@ static struct dentry *fat_get_parent(struct dentry *child_dir)
> }
>
> const struct export_operations fat_export_ops = {
> + .encode_fh = generic_encode_ino32_fh,
> .fh_to_dentry = fat_fh_to_dentry,
> .fh_to_parent = fat_fh_to_parent,
> .get_parent = fat_get_parent,
> diff --git a/fs/jffs2/super.c b/fs/jffs2/super.c
> index 7ea37f49f1e1..f99591a634b4 100644
> --- a/fs/jffs2/super.c
> +++ b/fs/jffs2/super.c
> @@ -150,6 +150,7 @@ static struct dentry *jffs2_get_parent(struct dentry *child)
> }
>
> static const struct export_operations jffs2_export_ops = {
> + .encode_fh = generic_encode_ino32_fh,
> .get_parent = jffs2_get_parent,
> .fh_to_dentry = jffs2_fh_to_dentry,
> .fh_to_parent = jffs2_fh_to_parent,
> diff --git a/fs/jfs/super.c b/fs/jfs/super.c
> index 2e2f7f6d36a0..2cc2632f3c47 100644
> --- a/fs/jfs/super.c
> +++ b/fs/jfs/super.c
> @@ -896,6 +896,7 @@ static const struct super_operations jfs_super_operations = {
> };
>
> static const struct export_operations jfs_export_operations = {
> + .encode_fh = generic_encode_ino32_fh,
> .fh_to_dentry = jfs_fh_to_dentry,
> .fh_to_parent = jfs_fh_to_parent,
> .get_parent = jfs_get_parent,
> diff --git a/fs/ntfs/namei.c b/fs/ntfs/namei.c
> index ab44f2db533b..d7498ddc4a72 100644
> --- a/fs/ntfs/namei.c
> +++ b/fs/ntfs/namei.c
> @@ -384,6 +384,7 @@ static struct dentry *ntfs_fh_to_parent(struct super_block *sb, struct fid *fid,
> * and due to using iget() whereas NTFS needs ntfs_iget().
> */
> const struct export_operations ntfs_export_ops = {
> + .encode_fh = generic_encode_ino32_fh,
> .get_parent = ntfs_get_parent, /* Find the parent of a given
> directory. */
> .fh_to_dentry = ntfs_fh_to_dentry,
> diff --git a/fs/ntfs3/super.c b/fs/ntfs3/super.c
> index 5661a363005e..661ffb5aa1e0 100644
> --- a/fs/ntfs3/super.c
> +++ b/fs/ntfs3/super.c
> @@ -789,6 +789,7 @@ static int ntfs_nfs_commit_metadata(struct inode *inode)
> }
>
> static const struct export_operations ntfs_export_ops = {
> + .encode_fh = generic_encode_ino32_fh,
> .fh_to_dentry = ntfs_fh_to_dentry,
> .fh_to_parent = ntfs_fh_to_parent,
> .get_parent = ntfs3_get_parent,
> diff --git a/fs/smb/client/export.c b/fs/smb/client/export.c
> index 37c28415df1e..834e9c9197b4 100644
> --- a/fs/smb/client/export.c
> +++ b/fs/smb/client/export.c
> @@ -41,13 +41,10 @@ static struct dentry *cifs_get_parent(struct dentry *dentry)
> }
>
> const struct export_operations cifs_export_ops = {
> + .encode_fh = generic_encode_ino32_fh,
> .get_parent = cifs_get_parent,
> -/* Following five export operations are unneeded so far and can default:
> - .get_dentry =
> - .get_name =
> - .find_exported_dentry =
> - .decode_fh =
> - .encode_fs = */
> +/* Following export operations are mandatory for NFS export support:
> + .fh_to_dentry = */
> };
>
> #endif /* CONFIG_CIFS_NFSD_EXPORT */
> diff --git a/fs/squashfs/export.c b/fs/squashfs/export.c
> index 723763746238..62972f0ff868 100644
> --- a/fs/squashfs/export.c
> +++ b/fs/squashfs/export.c
> @@ -173,6 +173,7 @@ __le64 *squashfs_read_inode_lookup_table(struct super_block *sb,
>
>
> const struct export_operations squashfs_export_ops = {
> + .encode_fh = generic_encode_ino32_fh,
> .fh_to_dentry = squashfs_fh_to_dentry,
> .fh_to_parent = squashfs_fh_to_parent,
> .get_parent = squashfs_get_parent
> diff --git a/fs/ufs/super.c b/fs/ufs/super.c
> index 23377c1baed9..a480810cd4e3 100644
> --- a/fs/ufs/super.c
> +++ b/fs/ufs/super.c
> @@ -137,6 +137,7 @@ static struct dentry *ufs_get_parent(struct dentry *child)
> }
>
> static const struct export_operations ufs_export_ops = {
> + .encode_fh = generic_encode_ino32_fh,
> .fh_to_dentry = ufs_fh_to_dentry,
> .fh_to_parent = ufs_fh_to_parent,
> .get_parent = ufs_get_parent,
> diff --git a/include/linux/exportfs.h b/include/linux/exportfs.h
> index 5b3c9f30b422..6b6e01321405 100644
> --- a/include/linux/exportfs.h
> +++ b/include/linux/exportfs.h
> @@ -235,7 +235,7 @@ extern int exportfs_encode_fh(struct dentry *dentry, struct fid *fid,
>
> static inline bool exportfs_can_encode_fid(const struct export_operations *nop)
> {
> - return nop;
> + return nop && nop->encode_fh;
The ->encode_fh() method returns an integer type, not a boolean. It
would be more clear if this were written
return nop && (nop->encode_fh != FILEID_ROOT);
(I'm just guessing at what you might have intended).
> }
>
> static inline bool exportfs_can_decode_fh(const struct export_operations *nop)
> @@ -279,6 +279,8 @@ extern struct dentry *exportfs_decode_fh(struct vfsmount *mnt, struct fid *fid,
> /*
> * Generic helpers for filesystems.
> */
> +int generic_encode_ino32_fh(struct inode *inode, __u32 *fh, int *max_len,
> + struct inode *parent);
> extern struct dentry *generic_fh_to_dentry(struct super_block *sb,
> struct fid *fid, int fh_len, int fh_type,
> struct inode *(*get_inode) (struct super_block *sb, u64 ino, u32 gen));
> --
> 2.34.1
>
--
Chuck Lever
