px4_autopilot/nuttx/fs/fs_inoderemove.c

/****************************************************************************
 * fs/fs_inoderemove.c
 *
 *   Copyright (C) 2007-2009 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <gnutt@nuttx.org>
 *
 * 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 <errno.h>

#include <nuttx/kmalloc.h>
#include <nuttx/fs/fs.h>

#include "fs_internal.h"

/****************************************************************************
 * Definitions
 ****************************************************************************/

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

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

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

/****************************************************************************
 * Name: inode_unlink
 ****************************************************************************/

static void inode_unlink(struct inode *node,
                         struct inode *peer,
                         struct inode *parent)
{
  /* If peer is non-null, then remove the node from the right of
   * of that peer node.
   */

  if (peer)
    {
      peer->i_peer = node->i_peer;
    }

  /* If parent is non-null, then remove the node from head of
   * of the list of children.
   */

  else if (parent)
    {
      parent->i_child = node->i_peer;
    }

  /* Otherwise, we must be removing the root inode. */

  else
    {
       root_inode = node->i_peer;
    }

  node->i_peer    = NULL;
}

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

/****************************************************************************
 * Name: inode_remove
 *
 * Description:
 *   Remove a node from the in-memory, inode tree
 *
 *   NOTE: Caller must hold the inode semaphore
 *
 ****************************************************************************/

int inode_remove(FAR const char *path)
{
  const char       *name = path;
  FAR struct inode *node;
  FAR struct inode *left;
  FAR struct inode *parent;

  if (!*path || path[0] != '/')
    {
      return -EINVAL;
    }

  /* Find the node to delete */

  node = inode_search(&name, &left, &parent, (const char **)NULL);
  if (node)
    {
      /* Found it, now remove it from the tree */

      inode_unlink(node, left, parent);

      /* We cannot delete it if there reference to the inode */

      if (node->i_crefs)
        {
          /* In that case, we will mark it deleted, when the FS
           * releases the inode, we will then, finally delete
           * the subtree.
           */

           node->i_flags |= FSNODEFLAG_DELETED;
           return -EBUSY;
        }
      else
        {
          /* And delete it now -- recursively to delete all of its children */

          inode_free(node->i_child);
          kfree(node);
          return OK;
        }
    }

  /* The node does not exist or it has references */

  return -ENOENT;
}