// 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/spinlock.h>
#include <linux/completion.h>
#include <linux/buffer_head.h>
#include <linux/gfs2_ondisk.h>
#include <linux/namei.h>
#include <linux/crc32.h>

#include "gfs2.h"
#include "incore.h"
#include "dir.h"
#include "glock.h"
#include "super.h"
#include "util.h"
#include "inode.h"

/**
 * gfs2_drevalidate - Check directory lookup consistency
 * @dir: expected parent directory inode
 * @name: expexted name
 * @dentry: dentry to check
 * @flags: lookup flags
 *
 * Check to make sure the lookup necessary to arrive at this inode from its
 * parent is still good.
 *
 * Returns: 1 if the dentry is ok, 0 if it isn't
 */

static int gfs2_drevalidate(struct inode *dir, const struct qstr *name,
                            struct dentry *dentry, unsigned int flags)
{
        struct gfs2_sbd *sdp = GFS2_SB(dir);
        struct gfs2_inode *dip = GFS2_I(dir);
        struct inode *inode;
        struct gfs2_holder d_gh;
        struct gfs2_inode *ip = NULL;
        int error, valid;
        int had_lock = 0;

        if (flags & LOOKUP_RCU)
                return -ECHILD;

        inode = d_inode(dentry);

        if (inode) {
                if (is_bad_inode(inode))
                        return 0;
                ip = GFS2_I(inode);
        }

        if (sdp->sd_lockstruct.ls_ops->lm_mount == NULL)
                return 1;

        had_lock = (gfs2_glock_is_locked_by_me(dip->i_gl) != NULL);
        if (!had_lock) {
                error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &d_gh);
                if (error)
                        return 0;
        }

        error = gfs2_dir_check(dir, name, ip);
        valid = inode ? !error : (error == -ENOENT);

        if (!had_lock)
                gfs2_glock_dq_uninit(&d_gh);
        return valid;
}

static int gfs2_dhash(const struct dentry *dentry, struct qstr *str)
{
        str->hash = gfs2_disk_hash(str->name, str->len);
        return 0;
}

static int gfs2_dentry_delete(const struct dentry *dentry)
{
        struct gfs2_inode *ginode;

        if (d_really_is_negative(dentry))
                return 0;

        ginode = GFS2_I(d_inode(dentry));
        if (!gfs2_holder_initialized(&ginode->i_iopen_gh))
                return 0;

        if (test_bit(GLF_DEMOTE, &ginode->i_iopen_gh.gh_gl->gl_flags))
                return 1;

        return 0;
}

const struct dentry_operations gfs2_dops = {
        .d_revalidate = gfs2_drevalidate,
        .d_hash = gfs2_dhash,
        .d_delete = gfs2_dentry_delete,
};