// SPDX-License-Identifier: CDDL-1.0
/*
 * This file and its contents are supplied under the terms of the
 * Common Development and Distribution License ("CDDL"), version 1.0.
 * You may only use this file in accordance with the terms of version
 * 1.0 of the CDDL.
 *
 * A full copy of the text of the CDDL should have accompanied this
 * source.  A copy of the CDDL is also available via the Internet at
 * https://opensource.org/license/CDDL-1.0.
 */

/*
 * Copyright (C) 2011 Lawrence Livermore National Security, LLC.
 */

#ifndef _ZFS_XATTR_H
#define	_ZFS_XATTR_H

#include <linux/posix_acl_xattr.h>

/*
 * 2.6.35 API change,
 * The const keyword was added to the 'struct xattr_handler' in the
 * generic Linux super_block structure.  To handle this we define an
 * appropriate xattr_handler_t typedef which can be used.  This was
 * the preferred solution because it keeps the code clean and readable.
 */
typedef const struct xattr_handler	xattr_handler_t;

/*
 * 4.5 API change,
 */
#define	ZPL_XATTR_LIST_WRAPPER(fn)					\
static bool								\
fn(struct dentry *dentry)						\
{									\
	return (!!__ ## fn(dentry->d_inode, NULL, 0, NULL, 0));		\
}

#ifdef HAVE_XATTR_GET_DENTRY_INODE_FLAGS
/*
 * Android API change,
 * The xattr_handler->get() callback also takes a flags arg.
 */
#define	ZPL_XATTR_GET_WRAPPER(fn)					\
static int								\
fn(const struct xattr_handler *handler, struct dentry *dentry,		\
    struct inode *inode, const char *name, void *buffer,		\
    size_t size, int flags)						\
{									\
	return (__ ## fn(inode, name, buffer, size));			\
}
#else
#define	ZPL_XATTR_GET_WRAPPER(fn)					\
static int								\
fn(const struct xattr_handler *handler, struct dentry *dentry,		\
    struct inode *inode, const char *name, void *buffer, size_t size)	\
{									\
	return (__ ## fn(inode, name, buffer, size));			\
}
#endif

#if defined(HAVE_IDMAP_MNTIDMAP)
#define	ZPL_XATTR_SET_WRAPPER(fn)					\
static int								\
fn(const struct xattr_handler *handler, struct mnt_idmap *user_ns,	\
    struct dentry *dentry, struct inode *inode, const char *name,	\
    const void *buffer, size_t size, int flags)	\
{									\
	return (__ ## fn(user_ns, inode, name, buffer, size, flags));	\
}
#elif defined(HAVE_IDMAP_USERNS)
#define	ZPL_XATTR_SET_WRAPPER(fn)					\
static int								\
fn(const struct xattr_handler *handler, struct user_namespace *user_ns, \
    struct dentry *dentry, struct inode *inode, const char *name,	\
    const void *buffer, size_t size, int flags)	\
{									\
	return (__ ## fn(user_ns, inode, name, buffer, size, flags));	\
}
#else
#define	ZPL_XATTR_SET_WRAPPER(fn)					\
static int								\
fn(const struct xattr_handler *handler, struct dentry *dentry,		\
    struct inode *inode, const char *name, const void *buffer,		\
    size_t size, int flags)						\
{									\
	return (__ ## fn(kcred->user_ns, inode, name, buffer, size, flags));\
}
#endif

/*
 * Linux 3.7 API change. posix_acl_{from,to}_xattr gained the user_ns
 * parameter.  All callers are expected to pass the &init_user_ns which
 * is available through the init credential (kcred).
 */
static inline struct posix_acl *
zpl_acl_from_xattr(const void *value, int size)
{
	return (posix_acl_from_xattr(kcred->user_ns, value, size));
}

/*
 * Linux 7.0 API change. posix_acl_to_xattr() changed from filling the
 * caller-provided buffer to allocating a buffer with enough space and
 * returning it. We wrap this up by copying the result into the provided
 * buffer and freeing the allocated buffer.
 */
static inline int
zpl_acl_to_xattr(struct posix_acl *acl, void *value, int size)
{
#ifdef HAVE_POSIX_ACL_TO_XATTR_ALLOC
	size_t s = 0;
	void *v = posix_acl_to_xattr(kcred->user_ns, acl, &s,
	    kmem_flags_convert(KM_SLEEP));
	if (v == NULL)
		return (-ENOMEM);
	memcpy(value, v, MIN(size, s));
	kfree(v);
	return (0);
#else
	return (posix_acl_to_xattr(kcred->user_ns, acl, value, size));
#endif
}

#endif /* _ZFS_XATTR_H */
