2646a1f61a
This code has been shamelessly stolen from XFS at the suggestion of Christoph Hellwig. I've not added support for cached ACLs so far... watch for that in a later patch, although this is designed in such a way that they should be easy to add. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com> Cc: Christoph Hellwig <hch@infradead.org>
340 lines
6.9 KiB
C
340 lines
6.9 KiB
C
/*
|
|
* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
|
|
* Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
|
|
*
|
|
* This copyrighted material is made available to anyone wishing to use,
|
|
* modify, copy, or redistribute it subject to the terms and conditions
|
|
* of the GNU General Public License version 2.
|
|
*/
|
|
|
|
#include <linux/sched.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/spinlock.h>
|
|
#include <linux/completion.h>
|
|
#include <linux/buffer_head.h>
|
|
#include <linux/xattr.h>
|
|
#include <linux/posix_acl.h>
|
|
#include <linux/posix_acl_xattr.h>
|
|
#include <linux/gfs2_ondisk.h>
|
|
|
|
#include "gfs2.h"
|
|
#include "incore.h"
|
|
#include "acl.h"
|
|
#include "xattr.h"
|
|
#include "glock.h"
|
|
#include "inode.h"
|
|
#include "meta_io.h"
|
|
#include "trans.h"
|
|
#include "util.h"
|
|
|
|
static int acl_get(struct gfs2_inode *ip, const char *name,
|
|
struct posix_acl **acl, struct gfs2_ea_location *el,
|
|
char **datap, unsigned int *lenp)
|
|
{
|
|
char *data;
|
|
unsigned int len;
|
|
int error;
|
|
|
|
el->el_bh = NULL;
|
|
|
|
if (!ip->i_eattr)
|
|
return 0;
|
|
|
|
error = gfs2_ea_find(ip, GFS2_EATYPE_SYS, name, el);
|
|
if (error)
|
|
return error;
|
|
if (!el->el_ea)
|
|
return 0;
|
|
if (!GFS2_EA_DATA_LEN(el->el_ea))
|
|
goto out;
|
|
|
|
len = GFS2_EA_DATA_LEN(el->el_ea);
|
|
data = kmalloc(len, GFP_NOFS);
|
|
error = -ENOMEM;
|
|
if (!data)
|
|
goto out;
|
|
|
|
error = gfs2_ea_get_copy(ip, el, data, len);
|
|
if (error < 0)
|
|
goto out_kfree;
|
|
error = 0;
|
|
|
|
if (acl) {
|
|
*acl = posix_acl_from_xattr(data, len);
|
|
if (IS_ERR(*acl))
|
|
error = PTR_ERR(*acl);
|
|
}
|
|
|
|
out_kfree:
|
|
if (error || !datap) {
|
|
kfree(data);
|
|
} else {
|
|
*datap = data;
|
|
*lenp = len;
|
|
}
|
|
out:
|
|
return error;
|
|
}
|
|
|
|
/**
|
|
* gfs2_check_acl - Check an ACL to see if we're allowed to do something
|
|
* @inode: the file we want to do something to
|
|
* @mask: what we want to do
|
|
*
|
|
* Returns: errno
|
|
*/
|
|
|
|
int gfs2_check_acl(struct inode *inode, int mask)
|
|
{
|
|
struct gfs2_ea_location el;
|
|
struct posix_acl *acl = NULL;
|
|
int error;
|
|
|
|
error = acl_get(GFS2_I(inode), GFS2_POSIX_ACL_ACCESS, &acl, &el, NULL, NULL);
|
|
brelse(el.el_bh);
|
|
if (error)
|
|
return error;
|
|
|
|
if (acl) {
|
|
error = posix_acl_permission(inode, acl, mask);
|
|
posix_acl_release(acl);
|
|
return error;
|
|
}
|
|
|
|
return -EAGAIN;
|
|
}
|
|
|
|
static int munge_mode(struct gfs2_inode *ip, mode_t mode)
|
|
{
|
|
struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
|
|
struct buffer_head *dibh;
|
|
int error;
|
|
|
|
error = gfs2_trans_begin(sdp, RES_DINODE, 0);
|
|
if (error)
|
|
return error;
|
|
|
|
error = gfs2_meta_inode_buffer(ip, &dibh);
|
|
if (!error) {
|
|
gfs2_assert_withdraw(sdp,
|
|
(ip->i_inode.i_mode & S_IFMT) == (mode & S_IFMT));
|
|
ip->i_inode.i_mode = mode;
|
|
gfs2_trans_add_bh(ip->i_gl, dibh, 1);
|
|
gfs2_dinode_out(ip, dibh->b_data);
|
|
brelse(dibh);
|
|
}
|
|
|
|
gfs2_trans_end(sdp);
|
|
|
|
return 0;
|
|
}
|
|
|
|
int gfs2_acl_create(struct gfs2_inode *dip, struct gfs2_inode *ip)
|
|
{
|
|
struct gfs2_ea_location el;
|
|
struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
|
|
struct posix_acl *acl = NULL, *clone;
|
|
mode_t mode = ip->i_inode.i_mode;
|
|
char *data = NULL;
|
|
unsigned int len;
|
|
int error;
|
|
|
|
if (!sdp->sd_args.ar_posix_acl)
|
|
return 0;
|
|
if (S_ISLNK(ip->i_inode.i_mode))
|
|
return 0;
|
|
|
|
error = acl_get(dip, GFS2_POSIX_ACL_DEFAULT, &acl, &el, &data, &len);
|
|
brelse(el.el_bh);
|
|
if (error)
|
|
return error;
|
|
if (!acl) {
|
|
mode &= ~current_umask();
|
|
if (mode != ip->i_inode.i_mode)
|
|
error = munge_mode(ip, mode);
|
|
return error;
|
|
}
|
|
|
|
clone = posix_acl_clone(acl, GFP_NOFS);
|
|
error = -ENOMEM;
|
|
if (!clone)
|
|
goto out;
|
|
posix_acl_release(acl);
|
|
acl = clone;
|
|
|
|
if (S_ISDIR(ip->i_inode.i_mode)) {
|
|
error = gfs2_xattr_set(&ip->i_inode, GFS2_EATYPE_SYS,
|
|
GFS2_POSIX_ACL_DEFAULT, data, len, 0);
|
|
if (error)
|
|
goto out;
|
|
}
|
|
|
|
error = posix_acl_create_masq(acl, &mode);
|
|
if (error < 0)
|
|
goto out;
|
|
if (error == 0)
|
|
goto munge;
|
|
|
|
posix_acl_to_xattr(acl, data, len);
|
|
error = gfs2_xattr_set(&ip->i_inode, GFS2_EATYPE_SYS,
|
|
GFS2_POSIX_ACL_ACCESS, data, len, 0);
|
|
if (error)
|
|
goto out;
|
|
munge:
|
|
error = munge_mode(ip, mode);
|
|
out:
|
|
posix_acl_release(acl);
|
|
kfree(data);
|
|
return error;
|
|
}
|
|
|
|
int gfs2_acl_chmod(struct gfs2_inode *ip, struct iattr *attr)
|
|
{
|
|
struct posix_acl *acl = NULL, *clone;
|
|
struct gfs2_ea_location el;
|
|
char *data;
|
|
unsigned int len;
|
|
int error;
|
|
|
|
error = acl_get(ip, GFS2_POSIX_ACL_ACCESS, &acl, &el, &data, &len);
|
|
if (error)
|
|
goto out_brelse;
|
|
if (!acl)
|
|
return gfs2_setattr_simple(ip, attr);
|
|
|
|
clone = posix_acl_clone(acl, GFP_NOFS);
|
|
error = -ENOMEM;
|
|
if (!clone)
|
|
goto out;
|
|
posix_acl_release(acl);
|
|
acl = clone;
|
|
|
|
error = posix_acl_chmod_masq(acl, attr->ia_mode);
|
|
if (!error) {
|
|
posix_acl_to_xattr(acl, data, len);
|
|
error = gfs2_ea_acl_chmod(ip, &el, attr, data);
|
|
}
|
|
|
|
out:
|
|
posix_acl_release(acl);
|
|
kfree(data);
|
|
out_brelse:
|
|
brelse(el.el_bh);
|
|
return error;
|
|
}
|
|
|
|
static int gfs2_acl_type(const char *name)
|
|
{
|
|
if (strcmp(name, GFS2_POSIX_ACL_ACCESS) == 0)
|
|
return ACL_TYPE_ACCESS;
|
|
if (strcmp(name, GFS2_POSIX_ACL_DEFAULT) == 0)
|
|
return ACL_TYPE_DEFAULT;
|
|
return -EINVAL;
|
|
}
|
|
|
|
static int gfs2_xattr_system_get(struct inode *inode, const char *name,
|
|
void *buffer, size_t size)
|
|
{
|
|
int type;
|
|
|
|
type = gfs2_acl_type(name);
|
|
if (type < 0)
|
|
return type;
|
|
|
|
return gfs2_xattr_get(inode, GFS2_EATYPE_SYS, name, buffer, size);
|
|
}
|
|
|
|
static int gfs2_set_mode(struct inode *inode, mode_t mode)
|
|
{
|
|
int error = 0;
|
|
|
|
if (mode != inode->i_mode) {
|
|
struct iattr iattr;
|
|
|
|
iattr.ia_valid = ATTR_MODE;
|
|
iattr.ia_mode = mode;
|
|
|
|
error = gfs2_setattr_simple(GFS2_I(inode), &iattr);
|
|
}
|
|
|
|
return error;
|
|
}
|
|
|
|
static int gfs2_xattr_system_set(struct inode *inode, const char *name,
|
|
const void *value, size_t size, int flags)
|
|
{
|
|
struct gfs2_sbd *sdp = GFS2_SB(inode);
|
|
struct posix_acl *acl = NULL;
|
|
int error = 0, type;
|
|
|
|
if (!sdp->sd_args.ar_posix_acl)
|
|
return -EOPNOTSUPP;
|
|
|
|
type = gfs2_acl_type(name);
|
|
if (type < 0)
|
|
return type;
|
|
if (flags & XATTR_CREATE)
|
|
return -EINVAL;
|
|
if (type == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode))
|
|
return value ? -EACCES : 0;
|
|
if ((current_fsuid() != inode->i_uid) && !capable(CAP_FOWNER))
|
|
return -EPERM;
|
|
if (S_ISLNK(inode->i_mode))
|
|
return -EOPNOTSUPP;
|
|
|
|
if (!value)
|
|
goto set_acl;
|
|
|
|
acl = posix_acl_from_xattr(value, size);
|
|
if (!acl) {
|
|
/*
|
|
* acl_set_file(3) may request that we set default ACLs with
|
|
* zero length -- defend (gracefully) against that here.
|
|
*/
|
|
goto out;
|
|
}
|
|
if (IS_ERR(acl)) {
|
|
error = PTR_ERR(acl);
|
|
goto out;
|
|
}
|
|
|
|
error = posix_acl_valid(acl);
|
|
if (error)
|
|
goto out_release;
|
|
|
|
error = -EINVAL;
|
|
if (acl->a_count > GFS2_ACL_MAX_ENTRIES)
|
|
goto out_release;
|
|
|
|
if (type == ACL_TYPE_ACCESS) {
|
|
mode_t mode = inode->i_mode;
|
|
error = posix_acl_equiv_mode(acl, &mode);
|
|
|
|
if (error <= 0) {
|
|
posix_acl_release(acl);
|
|
acl = NULL;
|
|
|
|
if (error < 0)
|
|
return error;
|
|
}
|
|
|
|
error = gfs2_set_mode(inode, mode);
|
|
if (error)
|
|
goto out_release;
|
|
}
|
|
|
|
set_acl:
|
|
error = gfs2_xattr_set(inode, GFS2_EATYPE_SYS, name, value, size, 0);
|
|
out_release:
|
|
posix_acl_release(acl);
|
|
out:
|
|
return error;
|
|
}
|
|
|
|
struct xattr_handler gfs2_xattr_system_handler = {
|
|
.prefix = XATTR_SYSTEM_PREFIX,
|
|
.get = gfs2_xattr_system_get,
|
|
.set = gfs2_xattr_system_set,
|
|
};
|
|
|