exportfs: make ->encode_fh() a mandatory method for NFS export

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.

After this change, exportfs_encode_inode_fh() no longer has a default
implementation to encode FILEID_INO32_GEN* file handles.

This is a step towards allowing filesystems to encode non-decodeable
file handles for fanotify without having to implement any
export_operations.

Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Acked-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Link: https://lore.kernel.org/r/20231023180801.2953446-3-amir73il@gmail.com
Acked-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>
This commit is contained in:
Amir Goldstein 2023-10-23 21:07:59 +03:00 committed by Christian Brauner
parent 66c62769bc
commit e21fc2038c
No known key found for this signature in database
GPG key ID: 91C61BC06578DCA2
19 changed files with 47 additions and 19 deletions

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@ -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

View file

@ -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.
Filesystems that used the default implementation may use the generic helper
generic_encode_ino32_fh() explicitly.

View file

@ -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,

View file

@ -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,

View file

@ -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,

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@ -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,

View file

@ -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
* @max_len: maximum length to store there
* @fh: where to store the file handle fragment
* @max_len: maximum length to store there (in 4 byte units)
* @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);

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@ -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,

View file

@ -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,

View file

@ -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,

View file

@ -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,

View file

@ -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,

View file

@ -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,

View file

@ -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,

View file

@ -811,6 +811,7 @@ 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,

View file

@ -41,13 +41,12 @@ 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 */

View file

@ -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

View file

@ -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,

View file

@ -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;
}
static inline bool exportfs_can_decode_fh(const struct export_operations *nop)
@ -279,6 +279,13 @@ extern struct dentry *exportfs_decode_fh(struct vfsmount *mnt, struct fid *fid,
/*
* Generic helpers for filesystems.
*/
#ifdef CONFIG_EXPORTFS
int generic_encode_ino32_fh(struct inode *inode, __u32 *fh, int *max_len,
struct inode *parent);
#else
#define generic_encode_ino32_fh NULL
#endif
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));