linux/fs/ceph/acl.c

195 lines
4.3 KiB
C

/*
* linux/fs/ceph/acl.c
*
* Copyright (C) 2013 Guangliang Zhao, <lucienchao@gmail.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#include <linux/ceph/ceph_debug.h>
#include <linux/fs.h>
#include <linux/string.h>
#include <linux/xattr.h>
#include <linux/posix_acl_xattr.h>
#include <linux/posix_acl.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include "super.h"
static inline void ceph_set_cached_acl(struct inode *inode,
int type, struct posix_acl *acl)
{
struct ceph_inode_info *ci = ceph_inode(inode);
spin_lock(&ci->i_ceph_lock);
if (__ceph_caps_issued_mask(ci, CEPH_CAP_XATTR_SHARED, 0))
set_cached_acl(inode, type, acl);
spin_unlock(&ci->i_ceph_lock);
}
static inline struct posix_acl *ceph_get_cached_acl(struct inode *inode,
int type)
{
struct ceph_inode_info *ci = ceph_inode(inode);
struct posix_acl *acl = ACL_NOT_CACHED;
spin_lock(&ci->i_ceph_lock);
if (__ceph_caps_issued_mask(ci, CEPH_CAP_XATTR_SHARED, 0))
acl = get_cached_acl(inode, type);
spin_unlock(&ci->i_ceph_lock);
return acl;
}
struct posix_acl *ceph_get_acl(struct inode *inode, int type)
{
int size;
const char *name;
char *value = NULL;
struct posix_acl *acl;
switch (type) {
case ACL_TYPE_ACCESS:
name = POSIX_ACL_XATTR_ACCESS;
break;
case ACL_TYPE_DEFAULT:
name = POSIX_ACL_XATTR_DEFAULT;
break;
default:
BUG();
}
size = __ceph_getxattr(inode, name, "", 0);
if (size > 0) {
value = kzalloc(size, GFP_NOFS);
if (!value)
return ERR_PTR(-ENOMEM);
size = __ceph_getxattr(inode, name, value, size);
}
if (size > 0)
acl = posix_acl_from_xattr(&init_user_ns, value, size);
else if (size == -ERANGE || size == -ENODATA || size == 0)
acl = NULL;
else
acl = ERR_PTR(-EIO);
kfree(value);
if (!IS_ERR(acl))
ceph_set_cached_acl(inode, type, acl);
return acl;
}
int ceph_set_acl(struct inode *inode, struct posix_acl *acl, int type)
{
int ret = 0, size = 0;
const char *name = NULL;
char *value = NULL;
struct iattr newattrs;
umode_t new_mode = inode->i_mode, old_mode = inode->i_mode;
struct dentry *dentry;
switch (type) {
case ACL_TYPE_ACCESS:
name = POSIX_ACL_XATTR_ACCESS;
if (acl) {
ret = posix_acl_equiv_mode(acl, &new_mode);
if (ret < 0)
goto out;
if (ret == 0)
acl = NULL;
}
break;
case ACL_TYPE_DEFAULT:
if (!S_ISDIR(inode->i_mode)) {
ret = acl ? -EINVAL : 0;
goto out;
}
name = POSIX_ACL_XATTR_DEFAULT;
break;
default:
ret = -EINVAL;
goto out;
}
if (acl) {
size = posix_acl_xattr_size(acl->a_count);
value = kmalloc(size, GFP_NOFS);
if (!value) {
ret = -ENOMEM;
goto out;
}
ret = posix_acl_to_xattr(&init_user_ns, acl, value, size);
if (ret < 0)
goto out_free;
}
dentry = d_find_alias(inode);
if (new_mode != old_mode) {
newattrs.ia_mode = new_mode;
newattrs.ia_valid = ATTR_MODE;
ret = ceph_setattr(dentry, &newattrs);
if (ret)
goto out_dput;
}
ret = __ceph_setxattr(dentry, name, value, size, 0);
if (ret) {
if (new_mode != old_mode) {
newattrs.ia_mode = old_mode;
newattrs.ia_valid = ATTR_MODE;
ceph_setattr(dentry, &newattrs);
}
goto out_dput;
}
ceph_set_cached_acl(inode, type, acl);
out_dput:
dput(dentry);
out_free:
kfree(value);
out:
return ret;
}
int ceph_init_acl(struct dentry *dentry, struct inode *inode, struct inode *dir)
{
struct posix_acl *default_acl, *acl;
int error;
error = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
if (error)
return error;
if (!default_acl && !acl)
cache_no_acl(inode);
if (default_acl) {
error = ceph_set_acl(inode, default_acl, ACL_TYPE_DEFAULT);
posix_acl_release(default_acl);
}
if (acl) {
if (!error)
error = ceph_set_acl(inode, acl, ACL_TYPE_ACCESS);
posix_acl_release(acl);
}
return error;
}