incubator-nuttx/fs/nfs/nfs_util.c

/****************************************************************************
 * fs/nfs/nfs_util.h
 *
 *   Copyright (C) 2012 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name NuttX nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <nuttx/config.h>
#include <sys/types.h>
#include <sys/time.h>

#include <stdint.h>
#include <queue.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <errno.h>
#include <assert.h>
#include <debug.h>

#include <nuttx/fs/dirent.h>

#include "nfs_proto.h"
#include "nfs_mount.h"
#include "nfs_node.h"

/****************************************************************************
 * Private Types
 ****************************************************************************/

/****************************************************************************
 * Private Function Prototypes
 ****************************************************************************/

/****************************************************************************
 * Private Variables
 ****************************************************************************/

/****************************************************************************
 * Public Variables
 ****************************************************************************/

/****************************************************************************
 * Private Functions
 ****************************************************************************/

/****************************************************************************
 * Public Functions
 ****************************************************************************/

/****************************************************************************
 * Name: nfs_semtake
 ****************************************************************************/

void nfs_semtake(struct nfsmount *nmp)
{
  /* Take the semaphore (perhaps waiting) */

  while (sem_wait(&nmp->nm_sem) != 0)
    {
      /* The only case that an error should occur here is if
       * the wait was awakened by a signal.
       */

      ASSERT(*get_errno_ptr() == EINTR);
    }
}

/****************************************************************************
 * Name: nfs_semgive
 ****************************************************************************/

void nfs_semgive(struct nfsmount *nmp)
{
   sem_post(&nmp->nm_sem);
}

/****************************************************************************
 * Name: nfs_checkmount
 *
 * Desciption: Check if the mountpoint is still valid.
 *
 *   The caller should hold the mountpoint semaphore
 *
 ****************************************************************************/

int nfs_checkmount(struct nfsmount *nmp)
{
  struct nfsnode *file;
  struct inode *inode;
  struct geometry geo;
  int ret;

  /* If the fs_mounted flag is false, then we have already handled the loss
   * of the mount.
   */

  DEBUGASSERT(nmp && nmp->nm_blkdriver);
  if (nmp->nm_mounted)
    {
      /* We still think the mount is healthy.  Check an see if this is
       * still the case
       */

      inode = nmp->nm_blkdriver;
      if (inode->u.i_bops && inode->u.i_bops->geometry)
        {
          ret = inode->u.i_bops->geometry(inode, &geo);
          if (ret == OK && geo.geo_available && !geo.geo_mediachanged)
            {
              return OK;
            }
        }

      /* If we get here, the mount is NOT healthy */

      nmp->nm_mounted = false;

      /* Make sure that this is flagged in every opened file */

      for (file = nmp->nm_head; file; file = file->n_next)
        {
          file->n_open = false;
        }
    }
  return -ENODEV;
}