/***************************************************************************
 *
 * Copyright (C) 2001 International Business Machines
 * All rights reserved.
 *
 * This file is part of the GPFS mmfslinux kernel module.
 *
 * 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. The name of the author may not be used to endorse or promote products 
 *     derived from this software without specific prior written
 *     permission. 
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
 *
 *************************************************************************** */
/* @(#)90       1.28  src/avs/fs/mmfs/ts/kernext/gpl-linux/block.c, mmfs, avs_rgpfs24, rgpfs240610b 8/4/04 23:12:51 */
#if LINUX_KERNEL_VERSION < 2050000

#define __NO_VERSION__

#ifndef __KERNEL__
#define __KERNEL__
#endif

#include <Shark-gpl.h>

#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/stat.h>
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/blkdev.h>
#include <asm/uaccess.h>

#include <linux/devfs_fs_kernel.h>

#include <verdep.h>
#include <cxiTypes.h>
#include <linux2gpfs.h>
#include <cxiIOBuffer.h>
#include <cxiSharedSeg.h>
#include <cxiSystem.h>
#include <Trace.h>


/* Major number for GPFS filesystem /dev entries.  Note that FS_MAJOR
   is just our first choice for a number.  Since we don't have a reserved
   number (see linux/major.h) we have to be prepared to receive EBUSY when
   we register.  If FS_MAJOR is already taken, we allow devfs_register_blkdev
   to assign us any available number.  After we've registered, our major
   number will be stored in GPFSFileSysMajorNumber.  */
#define FS_MAJOR 239

static unsigned int GPFSFileSysMajorNumber = 0;


/* just return a zero'd buffer */
ssize_t 
gpfs_fb_read(struct file *file, char *buf, size_t nbytes, loff_t *ppos)
{
  ssize_t written = 0;
  int toWrite;
  int rc = 0;

  ENTER(0);
  TRACE3(TRACE_BOPS, 2, TRCID_FBREAD_ENTER,
         "gpfs_fb_read: enter file 0x%X buf 0x%X nbytes %d\n", 
         file, buf, nbytes);

  while (nbytes)
  {
    toWrite = (nbytes >= PAGE_SIZE) ? PAGE_SIZE : nbytes;

    rc = clear_user(buf, toWrite);
    if (rc)
      goto xerror;

    nbytes -= toWrite;
    buf += toWrite;
    written += toWrite;
  }

xerror:
  TRACE1(TRACE_BOPS, 2, TRCID_FBREAD_EXIT,
         "gpfs_fb_read: exit written %d\n", written);

  EXIT(0);
  return (rc ? -ENOSYS : written);
}

ssize_t 
gpfs_fb_write(struct file *file, const char *buf, size_t nbytes, loff_t *ppos)
{
  ENTER(0);
  TRACE3(TRACE_BOPS, 2, TRCID_FBWRITE_ENTER,
         "gpfs_fb_write: enter file 0x%X buf 0x%X nbytes %d\n", 
         file, buf, nbytes);
  EXIT(0);
  return nbytes;
}

int 
gpfs_fb_open(struct inode *inode, struct file *file)
{
  struct block_device *bdP;
  int openers;
  int count;

  ENTER(0);
  TRACE2(TRACE_BOPS, 2, TRCID_FBOPEN_ENTER,
         "gpfs_fb_open: inode 0x%X file 0x%X\n", inode, file);

  if (inode->i_bdev)
  {
    bdP = inode->i_bdev;

# if LINUX_KERNEL_VERSION >= 2041300
    openers = bdP->bd_openers;
    count   = atomic_read(&bdP->bd_count);
#else
    openers = atomic_read(&bdP->bd_openers);
    count   = atomic_read(&bdP->bd_count);
#endif

    TRACE3(TRACE_BOPS, 2, TRCID_FBOPEN_EXIT,
           "gpfs_fb_open: exit bdP 0x%lX openers %d count %d\n", 
           bdP, openers, count);
  }
  EXIT(0);
  return 0;
}

int 
gpfs_fb_release(struct inode *inode, struct file *file)
{
  struct block_device *bdP;
  int openers;
  int count;

  ENTER(0);
  TRACE2(TRACE_BOPS, 2, TRCID_FBRELEASE_ENTER,
         "gpfs_fb_release: inode 0x%X file 0x%X\n", inode, file);

  if (inode->i_bdev)
  {
    bdP = inode->i_bdev;
# if LINUX_KERNEL_VERSION >= 2041300
    openers = bdP->bd_openers;
    count   = atomic_read(&bdP->bd_count);
#else
    openers = atomic_read(&bdP->bd_openers);
    count   = atomic_read(&bdP->bd_count);
#endif

    /* We're responsible for calling this to lower the openers
     * count as we have a specific release routine.   We're using
     * BDEV_RAW since that doesn't incur any operations in 
     * blkdev_put()
     */
    blkdev_put(bdP, BDEV_RAW);

    TRACE3(TRACE_BOPS, 2, TRCID_FBRELEASE_EXIT,
           "gpfs_fb_release: exit bdP 0x%lX openers %d count %d\n", 
           bdP, openers, count);
  }
  EXIT(0);
  return 0;
}

int 
gpfs_fb_ioctl(struct inode *inode, struct file *file, unsigned p1, 
              unsigned long p2)
{
  ENTER(0);
  TRACE4(TRACE_BOPS, 2, TRCID_FBIOCTL_ENTER,
         "gpfs_fb_ioctl: inode 0x%X file 0x%X p1 %d p2 %d\n",
         inode, file, p1, p2);
  EXIT(0);
  return 0;
}

int
gpfs_b_open(struct inode *inode, struct file *file)
{
  struct block_device *bdP;
  int openers;
  int count;

  ENTER(0);
  TRACE2(TRACE_BOPS, 2, TRCID_BOPEN_ENTER,
         "gpfs_b_open: inode 0x%X file 0x%X\n", inode, file);
  if (!inode)
          return -EINVAL;

  if (inode->i_bdev)
  {
    bdP = inode->i_bdev;
# if LINUX_KERNEL_VERSION >= 2041300
    openers = bdP->bd_openers;
    count   = atomic_read(&bdP->bd_count);
#else
    openers = atomic_read(&bdP->bd_openers);
    count   = atomic_read(&bdP->bd_count);
#endif

    TRACE3(TRACE_BOPS, 2, TRCID_BOPEN_EXIT,
           "gpfs_b_open: exit bdP 0x%lX openers %d count %d\n", 
           bdP, openers, count);
  }
  file->f_op = &gpfs_fbps;

  EXIT(0);
  return 0;          /* success */
}

int 
gpfs_b_release(struct inode *inode, struct file *file)
{
  struct block_device *bdP;
  int openers;
  int count;

  ENTER(0);
  TRACE2(TRACE_BOPS, 2, TRCID_BRELEASE_ENTER,
         "gpfs_b_release: inode 0x%X file 0x%X\n", inode, file);

  if (inode->i_bdev)
  {
    bdP = inode->i_bdev;
# if LINUX_KERNEL_VERSION >= 2041300
    openers = bdP->bd_openers;
    count   = atomic_read(&bdP->bd_count);
#else
    openers = atomic_read(&bdP->bd_openers);
    count   = atomic_read(&bdP->bd_count);
#endif

    TRACE3(TRACE_BOPS, 2, TRCID_BRELEASE_EXIT,
           "gpfs_b_release: exit bdP 0x%lX openers %d count %d\n", 
           bdP, openers, count);
  }
  EXIT(0);
  return 0;          /* success */
}

int 
gpfs_b_ioctl(struct inode *inode, struct file *file, unsigned p1,
             unsigned long p2)
{
  ENTER(0);
  TRACE4(TRACE_BOPS, 2, TRCID_BIOCTL_ENTER,
         "gpfs_fb_ioctl: inode 0x%X file 0x%X p1 %d p2 %d\n",
         inode, file, p1, p2);
  EXIT(0);
  return 0;
}

int
gpfs_make_request(request_queue_t *rq, int rw, struct buffer_head *bh)
{
  ENTER(0);
  BUFHEAD_ERROR_IODONE(bh);
  EXIT(0);
  return 0;
}


int 
gpfs_block_init()
{
  int rc;

  ENTER(0);
  GPFSFileSysMajorNumber = FS_MAJOR;

retry:
  rc = register_blkdev(GPFSFileSysMajorNumber, "gpfs", &gpfs_bops);
  if (rc < 0)
  {
    TRACE2(TRACE_BOPS, 2, TRCID_BLOCK_011,
           "gpfs_block_init: unable to get major %d rc %d\n",
           GPFSFileSysMajorNumber, rc);

    /* If FS_MAJOR was already taken, register without specifying a major
       number (allow devfs_register_blkdev to choose an available one). */

    if ((rc == -EBUSY) && (GPFSFileSysMajorNumber == FS_MAJOR))
    {
      GPFSFileSysMajorNumber = 0;
      goto retry;
    }

    GPFSFileSysMajorNumber = 0;
    EXIT(0);
    return -1;
  }

  /* If devfs_register_blkdev chose the number, save it so we can
     properly unregister later. */

  if (GPFSFileSysMajorNumber == 0)
    GPFSFileSysMajorNumber = rc;


  /* set up a null strategy routine */
  blk_queue_make_request(BLK_DEFAULT_QUEUE(GPFSFileSysMajorNumber),
                         gpfs_make_request);
                          
  TRACE2(TRACE_BOPS, 2, TRCID_BLOCK_013,
         "gpfs_block_init: register_blkdev %d rc %d\n",
         GPFSFileSysMajorNumber, rc);
  EXIT(0);
  return 0;
}

void 
gpfs_block_clean()
{
  int rc;

  ENTER(0);
  rc = unregister_blkdev(GPFSFileSysMajorNumber, "gpfs");
  TRACE2(TRACE_BOPS, 2, TRCID_BLOCK_015,
         "gpfs_block_clean: unregister_blkdev %d rc %d\n",
         GPFSFileSysMajorNumber, rc);

  GPFSFileSysMajorNumber = 0;
  EXIT(0);
}
#endif /* LINUX_KERNEL_VERSION < 2050000 */