nxffs_initialize.c

/****************************************************************************
 * fs/nxffs/nxffs_initialize.c
 *
 *   Copyright (C) 2011 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
 *
 * References: Linux/Documentation/filesystems/romfs.txt
 *
 * 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 <assert.h>
#include <debug.h>

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

#include "nxffs.h"

/****************************************************************************
 * Pre-processor Definitions
 ****************************************************************************/

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

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

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

/* See fs_mount.c -- this structure is explicitly externed there.
 * We use the old-fashioned kind of initializers so that this will compile
 * with any compiler.
 */

const struct mountpt_operations nxffs_operations =
{
  nxffs_open,        /* open */
  nxffs_close,       /* close */
  nxffs_read,        /* read */
  nxffs_write,       /* write */
  NULL,              /* seek -- Use f_pos in struct file */
  nxffs_ioctl,       /* ioctl */
  NULL,              /* sync -- No buffered data */

  nxffs_opendir,     /* opendir */
  NULL,              /* closedir */
  nxffs_readdir,     /* readdir */
  nxffs_rewinddir,   /* rewinddir */

  nxffs_bind,        /* bind */
  nxffs_unbind,      /* unbind */
  nxffs_statfs,      /* statfs */

  nxffs_unlink,      /* unlink */
  NULL,              /* mkdir -- no directories */
  NULL,              /* rmdir -- no directories */
  NULL,              /* rename -- cannot rename in place if name is longer */
  nxffs_stat         /* stat */
};

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

/* A singly-linked list of open files */

struct nxffs_ofile_s *g_ofiles;

/* The magic number that appears that the beginning of each NXFFS (logical)
 * block
 */

const uint8_t g_blockmagic[NXFFS_MAGICSIZE] = { 'B', 'l', 'c', 'k' };

/* The magic number that appears that the beginning of each NXFFS inode */

const uint8_t g_inodemagic[NXFFS_MAGICSIZE] = { 'I', 'n', 'o', 'd' };

/* The magic number that appears that the beginning of each NXFFS inode
 * data block.
 */

const uint8_t g_datamagic[NXFFS_MAGICSIZE] = { 'D', 'a', 't', 'a' };

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

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

/****************************************************************************
 * Name: nxffs_initialize
 *
 * Description:
 *   Initialize to provide NXFFS on an MTD interface
 *
 * Input Parameters:
 *   mtd - The MTD device that supports the FLASH interface.
 *   start - The first block of the file system begins at this block number
 *     in the FLASH
 *   nblocks - This number of blocks is set aside for the file system.
 *
 ****************************************************************************/

int nxffs_initialize(FAR struct mtd_dev_s *mtd, off_t start, off_t nblocks)
{
  FAR struct nxffs_volume_s *volume;
  struct nxffs_blkstats_s stats;
  off_t threshold;
  int ret;

  /* Allocate a NXFFS volume structure */

  volume = (FAR struct nxffs_volume_s *)kzalloc(sizeof(struct nxffs_volume_s));
  if (!volume)
    {
      ret = -ENOMEM;
      goto errout;
    }

  /* Initialize the NXFFS volume structure */

  volume->mtd = mtd;

  /* Get the volume geometry. (casting to uintptr_t first eliminates
   * complaints on some architectures where the sizeof long is different
   * from the size of a pointer).
   */

  ret = MTD_IOCTL(mtd, MTDIOC_GEOMETRY, (unsigned long)((uintptr_t)&volume->geo));
  if (ret < 0)
    {
      fdbg("MTD ioctl(MTDIOC_GEOMETRY) failed: %d\n", -ret);
      goto errout_with_volume;
    }

  /* Allocate one, in-memory erase block buffer */

  volume->cache  = (FAR uint8_t *)kmalloc(volume->geo.erasesize);
  if (!volume->cache)
    {
      fdbg("Failed to allocate an erase block buffer\n");
      ret = -ENOMEM;
      goto errout_with_volume;
    }

  /* Get the number of R/W blocks per erase block */

  volume->blkper = volume->geo.erasesize / volume->geo.blocksize;
  DEBUGASSERT((off_t)volume->blkper * volume->geo.blocksize == volume->geo.erasesize);

  /* Check if there is a valid NXFFS file system on the flash */

  ret = nxffs_blockstats(volume, &stats);
  if (ret < 0)
    {
      fdbg("Failed to collect block statistics: %d\n", -ret);
      goto errout_with_iobuffer;
    }

  /* If the proportion of good blocks is low or the proportion of unformatted
   * blocks is high, then reformat the FLASH.
   */

  threshold = stats.nblocks / 5;
  if (stats.ngood < threshold || stats.nunformat > threshold)
    {
      /* Reformat the volume */

      ret = nxffs_reformat(volume);
      if (ret < 0)
        {
          fdbg("Failed to reformat the volume: %d\n", -ret);
          goto errout_with_iobuffer;
        }

      /* Get statistics on the re-formatted volume */

#if defined(CONFIG_DEBUG) && defined(CONFIG_DEBUG_FS)
      ret = nxffs_blockstats(volume, &stats);
      if (ret < 0)
        {
          fdbg("Failed to collect block statistics: %d\n", -ret);
          goto errout_with_iobuffer;
        }
#endif
    }

  /* Return success */

  return OK;

errout_with_iobuffer:
  kfree(volume->cache);
errout_with_volume:
  kfree(volume);
errout:
  return ret;
}

/****************************************************************************
 * Name: nxffs_limits
 *
 * Description:
 *   Recalculate file system limits:  (1) the FLASH offset to the first,
 *   valid inode, and (2) the FLASH offset to the first, unused byte after
 *   the last inode (invalid or not).
 *
 *   The first, lower limit must be recalculated: (1) initially, (2)
 *   whenever the first inode is deleted, or (3) whenever inode is moved
 *   as part of the clean-up operation.
 *
 *   The second, upper limit must be (1) incremented whenever new file
 *   data is written, or (2) recalculated as part of the clean-up operation.
 *
 * Input Parameters:
 *   volume - Identifies the NXFFS volume
 *
 * Returned Value:
 *   Zero on success. Otherwise, a negated error is returned indicating the
 *   nature of the failure.
 *
 ****************************************************************************/

int nxffs_limits(FAR struct nxffs_volume_s *volume)
{
#warning "Missing Logic"
}