Commit e36c5243 authored by Dave Kleikamp's avatar Dave Kleikamp

Add fs/jfs/acl.c

This file was somehow skipped (along with jfs_acl.h> when I checked in
the ACL support.
parent 5be2bc3c
/*
* Copyright (c) International Business Machines Corp., 2002
* Copyright (c) Andreas Gruenbacher, 2001
* Copyright (c) Linus Torvalds, 1991, 1992
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* 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 02111-1307 USA
*/
#include <linux/sched.h>
#include <linux/fs.h>
#include "jfs_incore.h"
#include "jfs_xattr.h"
#include "jfs_acl.h"
struct posix_acl *jfs_get_acl(struct inode *inode, int type)
{
struct posix_acl *acl;
char *ea_name;
struct jfs_inode_info *ji = JFS_IP(inode);
struct posix_acl **p_acl;
int size;
char *value = NULL;
switch(type) {
case ACL_TYPE_ACCESS:
ea_name = XATTR_NAME_ACL_ACCESS;
p_acl = &ji->i_acl;
break;
case ACL_TYPE_DEFAULT:
ea_name = XATTR_NAME_ACL_DEFAULT;
p_acl = &ji->i_default_acl;
break;
default:
return ERR_PTR(-EINVAL);
}
if (*p_acl != JFS_ACL_NOT_CACHED)
return posix_acl_dup(*p_acl);
size = __jfs_getxattr(inode, ea_name, NULL, 0);
if (size > 0) {
value = kmalloc(size, GFP_KERNEL);
if (!value)
return ERR_PTR(-ENOMEM);
size = __jfs_getxattr(inode, ea_name, value, size);
}
if (size < 0) {
if (size == -ENODATA) {
*p_acl = NULL;
acl = NULL;
} else
acl = ERR_PTR(size);
} else {
acl = posix_acl_from_xattr(value, size);
if (!IS_ERR(acl))
*p_acl = posix_acl_dup(acl);
}
if (value)
kfree(value);
return acl;
}
int jfs_set_acl(struct inode *inode, int type, struct posix_acl *acl)
{
char *ea_name;
struct jfs_inode_info *ji = JFS_IP(inode);
struct posix_acl **p_acl;
int rc;
int size = 0;
char *value = NULL;
if (S_ISLNK(inode->i_mode))
return -EOPNOTSUPP;
switch(type) {
case ACL_TYPE_ACCESS:
ea_name = XATTR_NAME_ACL_ACCESS;
p_acl = &ji->i_acl;
break;
case ACL_TYPE_DEFAULT:
ea_name = XATTR_NAME_ACL_DEFAULT;
p_acl = &ji->i_default_acl;
if (!S_ISDIR(inode->i_mode))
return acl ? -EACCES : 0;
break;
default:
return -EINVAL;
}
if (acl) {
size = xattr_acl_size(acl->a_count);
value = kmalloc(size, GFP_KERNEL);
if (!value)
return -ENOMEM;
rc = posix_acl_to_xattr(acl, value, size);
if (rc < 0)
goto out;
}
rc = __jfs_setxattr(inode, ea_name, value, size, 0);
out:
if (value)
kfree(value);
if (!rc) {
if (*p_acl && (*p_acl != JFS_ACL_NOT_CACHED))
posix_acl_release(*p_acl);
*p_acl = posix_acl_dup(acl);
}
return rc;
}
/*
* __jfs_permission()
*
* modified vfs_permission to check posix acl
*/
static int __jfs_permission(struct inode * inode, int mask, int have_sem)
{
umode_t mode = inode->i_mode;
struct jfs_inode_info *ji = JFS_IP(inode);
if (mask & MAY_WRITE) {
/*
* Nobody gets write access to a read-only fs.
*/
if (IS_RDONLY(inode) &&
(S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)))
return -EROFS;
/*
* Nobody gets write access to an immutable file.
*/
if (IS_IMMUTABLE(inode))
return -EACCES;
}
if (current->fsuid == inode->i_uid) {
mode >>= 6;
goto check_mode;
}
/*
* ACL can't contain additional permissions if the ACL_MASK entry
* is zero.
*/
if (!(mode & S_IRWXG))
goto check_groups;
if (ji->i_acl == JFS_ACL_NOT_CACHED) {
struct posix_acl *acl;
if (!have_sem)
down(&inode->i_sem);
acl = jfs_get_acl(inode, ACL_TYPE_ACCESS);
if (!have_sem)
up(&inode->i_sem);
if (IS_ERR(acl))
return PTR_ERR(acl);
posix_acl_release(acl);
}
if (ji->i_acl) {
int rc = posix_acl_permission(inode, ji->i_acl, mask);
if (rc == -EACCES)
goto check_capabilities;
return rc;
}
check_groups:
if (in_group_p(inode->i_gid))
mode >>= 3;
check_mode:
/*
* If the DACs are ok we don't need any capability check.
*/
if (((mode & mask & (MAY_READ|MAY_WRITE|MAY_EXEC)) == mask))
return 0;
check_capabilities:
/*
* Read/write DACs are always overridable.
* Executable DACs are overridable if at least one exec bit is set.
*/
if ((mask & (MAY_READ|MAY_WRITE)) || (inode->i_mode & S_IXUGO))
if (capable(CAP_DAC_OVERRIDE))
return 0;
/*
* Searching includes executable on directories, else just read.
*/
if (mask == MAY_READ || (S_ISDIR(inode->i_mode) && !(mask & MAY_WRITE)))
if (capable(CAP_DAC_READ_SEARCH))
return 0;
return -EACCES;
}
int jfs_permission(struct inode * inode, int mask)
{
return __jfs_permission(inode, mask, 0);
}
int jfs_permission_have_sem(struct inode * inode, int mask)
{
return __jfs_permission(inode, mask, 1);
}
int jfs_init_acl(struct inode *inode, struct inode *dir)
{
struct posix_acl *acl = NULL;
struct posix_acl *clone;
mode_t mode;
int rc = 0;
if (S_ISLNK(inode->i_mode))
return 0;
acl = jfs_get_acl(dir, ACL_TYPE_DEFAULT);
if (IS_ERR(acl))
return PTR_ERR(acl);
if (acl) {
if (S_ISDIR(inode->i_mode)) {
rc = jfs_set_acl(inode, ACL_TYPE_DEFAULT, acl);
if (rc)
goto cleanup;
}
clone = posix_acl_clone(acl, GFP_KERNEL);
if (!clone) {
rc = -ENOMEM;
goto cleanup;
}
mode = inode->i_mode;
rc = posix_acl_create_masq(clone, &mode);
if (rc >= 0) {
inode->i_mode = mode;
if (rc > 0)
rc = jfs_set_acl(inode, ACL_TYPE_ACCESS, clone);
}
posix_acl_release(clone);
cleanup:
posix_acl_release(acl);
} else
inode->i_mode &= ~current->fs->umask;
return rc;
}
int jfs_acl_chmod(struct inode *inode)
{
struct posix_acl *acl, *clone;
int rc;
if (S_ISLNK(inode->i_mode))
return -EOPNOTSUPP;
acl = jfs_get_acl(inode, ACL_TYPE_ACCESS);
if (IS_ERR(acl) || !acl)
return PTR_ERR(acl);
clone = posix_acl_clone(acl, GFP_KERNEL);
posix_acl_release(acl);
if (!clone)
return -ENOMEM;
rc = posix_acl_chmod_masq(clone, inode->i_mode);
if (!rc)
rc = jfs_set_acl(inode, ACL_TYPE_ACCESS, clone);
posix_acl_release(clone);
return rc;
}
int jfs_setattr(struct dentry *dentry, struct iattr *iattr)
{
struct inode *inode = dentry->d_inode;
int rc;
rc = inode_change_ok(inode, iattr);
if (rc)
return rc;
inode_setattr(inode, iattr);
if (iattr->ia_valid & ATTR_MODE)
rc = jfs_acl_chmod(inode);
return rc;
}
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