linux-imx

// SPDX-License-Identifier: GPL-2.0

#include <linux/syscalls.h>

#include <linux/slab.h>

#include <linux/fs.h>

#include <linux/file.h>

#include <linux/mount.h>

#include <linux/namei.h>

#include <linux/exportfs.h>

#include <linux/fs_struct.h>

#include <linux/fsnotify.h>

#include <linux/personality.h>

#include <linux/uaccess.h>

#include <linux/compat.h>

#include "internal.h"

#include "mount.h"

​

static long do_sys_name_to_handle(struct path *path,

                  struct file_handle __user *ufh,

                  int __user *mnt_id)

{

    long retval;

    struct file_handle f_handle;

    int handle_dwords, handle_bytes;

    struct file_handle *handle = NULL;

​

    /*

     * We need to make sure whether the file system

     * support decoding of the file handle

     */

    if (!path->dentry->d_sb->s_export_op ||

        !path->dentry->d_sb->s_export_op->fh_to_dentry)

        return -EOPNOTSUPP;

​

    if (copy_from_user(&f_handle, ufh, sizeof(struct file_handle)))

        return -EFAULT;

​

    if (f_handle.handle_bytes > MAX_HANDLE_SZ)

        return -EINVAL;

​

    handle = kmalloc(sizeof(struct file_handle) + f_handle.handle_bytes,

             GFP_KERNEL);

    if (!handle)

        return -ENOMEM;

​

    /* convert handle size to multiple of sizeof(u32) */

    handle_dwords = f_handle.handle_bytes >> 2;

​

    /* we ask for a non connected handle */

    retval = exportfs_encode_fh(path->dentry,

                    (struct fid *)handle->f_handle,

                    &handle_dwords,  0);

    handle->handle_type = retval;

    /* convert handle size to bytes */

    handle_bytes = handle_dwords * sizeof(u32);

    handle->handle_bytes = handle_bytes;

    if ((handle->handle_bytes > f_handle.handle_bytes) ||

        (retval == FILEID_INVALID) || (retval == -ENOSPC)) {

        /* As per old exportfs_encode_fh documentation

         * we could return ENOSPC to indicate overflow

         * But file system returned 255 always. So handle

         * both the values

         */

        /*