linux/include/linux/posix_acl.h
Christian Brauner 8043bffd01
acl: make posix_acl_clone() available to overlayfs
The ovl_get_acl() function needs to alter the POSIX ACLs retrieved from the
lower filesystem. Instead of hand-rolling a overlayfs specific
posix_acl_clone() variant allow export it. It's not special and it's not deeply
internal anyway.

Link: https://lore.kernel.org/r/20220708090134.385160-3-brauner@kernel.org
Cc: Seth Forshee <sforshee@digitalocean.com>
Cc: Amir Goldstein <amir73il@gmail.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Aleksa Sarai <cyphar@cyphar.com>
Cc: Miklos Szeredi <mszeredi@redhat.com>
Cc: linux-unionfs@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Seth Forshee <sforshee@digitalocean.com>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2022-07-15 22:09:57 +02:00

134 lines
3.3 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
File: linux/posix_acl.h
(C) 2002 Andreas Gruenbacher, <a.gruenbacher@computer.org>
*/
#ifndef __LINUX_POSIX_ACL_H
#define __LINUX_POSIX_ACL_H
#include <linux/bug.h>
#include <linux/slab.h>
#include <linux/rcupdate.h>
#include <linux/refcount.h>
#include <uapi/linux/posix_acl.h>
struct user_namespace;
struct posix_acl_entry {
short e_tag;
unsigned short e_perm;
union {
kuid_t e_uid;
kgid_t e_gid;
};
};
struct posix_acl {
refcount_t a_refcount;
struct rcu_head a_rcu;
unsigned int a_count;
struct posix_acl_entry a_entries[];
};
#define FOREACH_ACL_ENTRY(pa, acl, pe) \
for(pa=(acl)->a_entries, pe=pa+(acl)->a_count; pa<pe; pa++)
/*
* Duplicate an ACL handle.
*/
static inline struct posix_acl *
posix_acl_dup(struct posix_acl *acl)
{
if (acl)
refcount_inc(&acl->a_refcount);
return acl;
}
/*
* Free an ACL handle.
*/
static inline void
posix_acl_release(struct posix_acl *acl)
{
if (acl && refcount_dec_and_test(&acl->a_refcount))
kfree_rcu(acl, a_rcu);
}
/* posix_acl.c */
extern void posix_acl_init(struct posix_acl *, int);
extern struct posix_acl *posix_acl_alloc(int, gfp_t);
extern struct posix_acl *posix_acl_from_mode(umode_t, gfp_t);
extern int posix_acl_equiv_mode(const struct posix_acl *, umode_t *);
extern int __posix_acl_create(struct posix_acl **, gfp_t, umode_t *);
extern int __posix_acl_chmod(struct posix_acl **, gfp_t, umode_t);
extern struct posix_acl *get_posix_acl(struct inode *, int);
extern int set_posix_acl(struct user_namespace *, struct inode *, int,
struct posix_acl *);
struct posix_acl *get_cached_acl_rcu(struct inode *inode, int type);
struct posix_acl *posix_acl_clone(const struct posix_acl *acl, gfp_t flags);
#ifdef CONFIG_FS_POSIX_ACL
int posix_acl_chmod(struct user_namespace *, struct inode *, umode_t);
extern int posix_acl_create(struct inode *, umode_t *, struct posix_acl **,
struct posix_acl **);
int posix_acl_update_mode(struct user_namespace *, struct inode *, umode_t *,
struct posix_acl **);
extern int simple_set_acl(struct user_namespace *, struct inode *,
struct posix_acl *, int);
extern int simple_acl_create(struct inode *, struct inode *);
struct posix_acl *get_cached_acl(struct inode *inode, int type);
void set_cached_acl(struct inode *inode, int type, struct posix_acl *acl);
void forget_cached_acl(struct inode *inode, int type);
void forget_all_cached_acls(struct inode *inode);
int posix_acl_valid(struct user_namespace *, const struct posix_acl *);
int posix_acl_permission(struct user_namespace *, struct inode *,
const struct posix_acl *, int);
static inline void cache_no_acl(struct inode *inode)
{
inode->i_acl = NULL;
inode->i_default_acl = NULL;
}
#else
static inline int posix_acl_chmod(struct user_namespace *mnt_userns,
struct inode *inode, umode_t mode)
{
return 0;
}
#define simple_set_acl NULL
static inline int simple_acl_create(struct inode *dir, struct inode *inode)
{
return 0;
}
static inline void cache_no_acl(struct inode *inode)
{
}
static inline int posix_acl_create(struct inode *inode, umode_t *mode,
struct posix_acl **default_acl, struct posix_acl **acl)
{
*default_acl = *acl = NULL;
return 0;
}
static inline void forget_all_cached_acls(struct inode *inode)
{
}
#endif /* CONFIG_FS_POSIX_ACL */
struct posix_acl *get_acl(struct inode *inode, int type);
#endif /* __LINUX_POSIX_ACL_H */