cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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acl.c (3300B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
      4 * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
      5 */
      6
      7#include <linux/sched.h>
      8#include <linux/slab.h>
      9#include <linux/spinlock.h>
     10#include <linux/completion.h>
     11#include <linux/buffer_head.h>
     12#include <linux/xattr.h>
     13#include <linux/posix_acl.h>
     14#include <linux/posix_acl_xattr.h>
     15#include <linux/gfs2_ondisk.h>
     16
     17#include "gfs2.h"
     18#include "incore.h"
     19#include "acl.h"
     20#include "xattr.h"
     21#include "glock.h"
     22#include "inode.h"
     23#include "meta_io.h"
     24#include "quota.h"
     25#include "rgrp.h"
     26#include "trans.h"
     27#include "util.h"
     28
     29static const char *gfs2_acl_name(int type)
     30{
     31	switch (type) {
     32	case ACL_TYPE_ACCESS:
     33		return XATTR_POSIX_ACL_ACCESS;
     34	case ACL_TYPE_DEFAULT:
     35		return XATTR_POSIX_ACL_DEFAULT;
     36	}
     37	return NULL;
     38}
     39
     40static struct posix_acl *__gfs2_get_acl(struct inode *inode, int type)
     41{
     42	struct gfs2_inode *ip = GFS2_I(inode);
     43	struct posix_acl *acl;
     44	const char *name;
     45	char *data;
     46	int len;
     47
     48	if (!ip->i_eattr)
     49		return NULL;
     50
     51	name = gfs2_acl_name(type);
     52	len = gfs2_xattr_acl_get(ip, name, &data);
     53	if (len <= 0)
     54		return ERR_PTR(len);
     55	acl = posix_acl_from_xattr(&init_user_ns, data, len);
     56	kfree(data);
     57	return acl;
     58}
     59
     60struct posix_acl *gfs2_get_acl(struct inode *inode, int type, bool rcu)
     61{
     62	struct gfs2_inode *ip = GFS2_I(inode);
     63	struct gfs2_holder gh;
     64	bool need_unlock = false;
     65	struct posix_acl *acl;
     66
     67	if (rcu)
     68		return ERR_PTR(-ECHILD);
     69
     70	if (!gfs2_glock_is_locked_by_me(ip->i_gl)) {
     71		int ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED,
     72					     LM_FLAG_ANY, &gh);
     73		if (ret)
     74			return ERR_PTR(ret);
     75		need_unlock = true;
     76	}
     77	acl = __gfs2_get_acl(inode, type);
     78	if (need_unlock)
     79		gfs2_glock_dq_uninit(&gh);
     80	return acl;
     81}
     82
     83int __gfs2_set_acl(struct inode *inode, struct posix_acl *acl, int type)
     84{
     85	int error;
     86	size_t len;
     87	char *data;
     88	const char *name = gfs2_acl_name(type);
     89
     90	if (acl) {
     91		len = posix_acl_xattr_size(acl->a_count);
     92		data = kmalloc(len, GFP_NOFS);
     93		if (data == NULL)
     94			return -ENOMEM;
     95		error = posix_acl_to_xattr(&init_user_ns, acl, data, len);
     96		if (error < 0)
     97			goto out;
     98	} else {
     99		data = NULL;
    100		len = 0;
    101	}
    102
    103	error = __gfs2_xattr_set(inode, name, data, len, 0, GFS2_EATYPE_SYS);
    104	if (error)
    105		goto out;
    106	set_cached_acl(inode, type, acl);
    107out:
    108	kfree(data);
    109	return error;
    110}
    111
    112int gfs2_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
    113		 struct posix_acl *acl, int type)
    114{
    115	struct gfs2_inode *ip = GFS2_I(inode);
    116	struct gfs2_holder gh;
    117	bool need_unlock = false;
    118	int ret;
    119	umode_t mode;
    120
    121	if (acl && acl->a_count > GFS2_ACL_MAX_ENTRIES(GFS2_SB(inode)))
    122		return -E2BIG;
    123
    124	ret = gfs2_qa_get(ip);
    125	if (ret)
    126		return ret;
    127
    128	if (!gfs2_glock_is_locked_by_me(ip->i_gl)) {
    129		ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
    130		if (ret)
    131			goto out;
    132		need_unlock = true;
    133	}
    134
    135	mode = inode->i_mode;
    136	if (type == ACL_TYPE_ACCESS && acl) {
    137		ret = posix_acl_update_mode(&init_user_ns, inode, &mode, &acl);
    138		if (ret)
    139			goto unlock;
    140	}
    141
    142	ret = __gfs2_set_acl(inode, acl, type);
    143	if (!ret && mode != inode->i_mode) {
    144		inode->i_ctime = current_time(inode);
    145		inode->i_mode = mode;
    146		mark_inode_dirty(inode);
    147	}
    148unlock:
    149	if (need_unlock)
    150		gfs2_glock_dq_uninit(&gh);
    151out:
    152	gfs2_qa_put(ip);
    153	return ret;
    154}