// 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 = 0;
        char *data = NULL;
        const char *name = gfs2_acl_name(type);

        if (acl) {
                data = posix_acl_to_xattr(&init_user_ns, acl, &len, GFP_NOFS);
                if (data == NULL)
                        return -ENOMEM;
        }

        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 mnt_idmap *idmap, struct dentry *dentry,
                 struct posix_acl *acl, int type)
{
        struct inode *inode = d_inode(dentry);
        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(&nop_mnt_idmap, inode, &mode, &acl);
                if (ret)
                        goto unlock;
        }

        ret = __gfs2_set_acl(inode, acl, type);
        if (!ret && mode != inode->i_mode) {
                inode_set_ctime_current(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;
}