linux-stable/fs/gfs2/acl.c
Miklos Szeredi 0cad624662 vfs: add rcu argument to ->get_acl() callback
Add a rcu argument to the ->get_acl() callback to allow
get_cached_acl_rcu() to call the ->get_acl() method in the next patch.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-08-18 22:08:24 +02:00

154 lines
3.2 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
* Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
*/
#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 "quota.h"
#include "rgrp.h"
#include "trans.h"
#include "util.h"
static const char *gfs2_acl_name(int type)
{
switch (type) {
case ACL_TYPE_ACCESS:
return XATTR_POSIX_ACL_ACCESS;
case ACL_TYPE_DEFAULT:
return XATTR_POSIX_ACL_DEFAULT;
}
return NULL;
}
static struct posix_acl *__gfs2_get_acl(struct inode *inode, int type)
{
struct gfs2_inode *ip = GFS2_I(inode);
struct posix_acl *acl;
const char *name;
char *data;
int len;
if (!ip->i_eattr)
return NULL;
name = gfs2_acl_name(type);
len = gfs2_xattr_acl_get(ip, name, &data);
if (len <= 0)
return ERR_PTR(len);
acl = posix_acl_from_xattr(&init_user_ns, data, len);
kfree(data);
return acl;
}
struct posix_acl *gfs2_get_acl(struct inode *inode, int type, bool rcu)
{
struct gfs2_inode *ip = GFS2_I(inode);
struct gfs2_holder gh;
bool need_unlock = false;
struct posix_acl *acl;
if (rcu)
return ERR_PTR(-ECHILD);
if (!gfs2_glock_is_locked_by_me(ip->i_gl)) {
int ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED,
LM_FLAG_ANY, &gh);
if (ret)
return ERR_PTR(ret);
need_unlock = true;
}
acl = __gfs2_get_acl(inode, type);
if (need_unlock)
gfs2_glock_dq_uninit(&gh);
return acl;
}
int __gfs2_set_acl(struct inode *inode, struct posix_acl *acl, int type)
{
int error;
size_t len;
char *data;
const char *name = gfs2_acl_name(type);
if (acl) {
len = posix_acl_xattr_size(acl->a_count);
data = kmalloc(len, GFP_NOFS);
if (data == NULL)
return -ENOMEM;
error = posix_acl_to_xattr(&init_user_ns, acl, data, len);
if (error < 0)
goto out;
} else {
data = NULL;
len = 0;
}
error = __gfs2_xattr_set(inode, name, data, len, 0, GFS2_EATYPE_SYS);
if (error)
goto out;
set_cached_acl(inode, type, acl);
out:
kfree(data);
return error;
}
int gfs2_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
struct posix_acl *acl, int type)
{
struct gfs2_inode *ip = GFS2_I(inode);
struct gfs2_holder gh;
bool need_unlock = false;
int ret;
umode_t mode;
if (acl && acl->a_count > GFS2_ACL_MAX_ENTRIES(GFS2_SB(inode)))
return -E2BIG;
ret = gfs2_qa_get(ip);
if (ret)
return ret;
if (!gfs2_glock_is_locked_by_me(ip->i_gl)) {
ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
if (ret)
goto out;
need_unlock = true;
}
mode = inode->i_mode;
if (type == ACL_TYPE_ACCESS && acl) {
ret = posix_acl_update_mode(&init_user_ns, inode, &mode, &acl);
if (ret)
goto unlock;
}
ret = __gfs2_set_acl(inode, acl, type);
if (!ret && mode != inode->i_mode) {
inode->i_ctime = current_time(inode);
inode->i_mode = mode;
mark_inode_dirty(inode);
}
unlock:
if (need_unlock)
gfs2_glock_dq_uninit(&gh);
out:
gfs2_qa_put(ip);
return ret;
}