/*
   * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.

   * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.

   *
   * This copyrighted material is made available to anyone wishing to use,
   * modify, copy, or redistribute it subject to the terms and conditions

   * of the GNU General Public License version 2.

   */
  
  #include <linux/sched.h>
  #include <linux/slab.h>
  #include <linux/spinlock.h>
  #include <linux/completion.h>
  #include <linux/buffer_head.h>

  #include <linux/kallsyms.h>

  #include <linux/gfs2_ondisk.h>

  
  #include "gfs2.h"

  #include "incore.h"

  #include "glock.h"
  #include "log.h"
  #include "lops.h"
  #include "meta_io.h"
  #include "trans.h"

  #include "util.h"

  #include "trace_gfs2.h"

  int gfs2_trans_begin(struct gfs2_sbd *sdp, unsigned int blocks,
  		     unsigned int revokes)

  {
  	struct gfs2_trans *tr;
  	int error;

  	BUG_ON(current->journal_info);
  	BUG_ON(blocks == 0 && revokes == 0);

  	if (!test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags))
  		return -EROFS;

  	tr = kzalloc(sizeof(struct gfs2_trans), GFP_NOFS);

  	if (!tr)
  		return -ENOMEM;

  	tr->tr_ip = (unsigned long)__builtin_return_address(0);

  	tr->tr_blocks = blocks;
  	tr->tr_revokes = revokes;
  	tr->tr_reserved = 1;
  	if (blocks)

  		tr->tr_reserved += 6 + blocks;

  	if (revokes)
  		tr->tr_reserved += gfs2_struct2blk(sdp, revokes,

  						   sizeof(u64));

  	INIT_LIST_HEAD(&tr->tr_list_buf);

  	gfs2_holder_init(sdp->sd_trans_gl, LM_ST_SHARED, 0, &tr->tr_t_gh);

  	error = gfs2_glock_nq(&tr->tr_t_gh);

  	if (error)

  		goto fail_holder_uninit;

  	error = gfs2_log_reserve(sdp, tr->tr_reserved);
  	if (error)
  		goto fail_gunlock;

  	current->journal_info = tr;

  
  	return 0;

  fail_gunlock:

  	gfs2_glock_dq(&tr->tr_t_gh);

  fail_holder_uninit:

  	gfs2_holder_uninit(&tr->tr_t_gh);

  	kfree(tr);
  
  	return error;
  }

  /**
   * gfs2_log_release - Release a given number of log blocks
   * @sdp: The GFS2 superblock
   * @blks: The number of blocks
   *
   */
  
  static void gfs2_log_release(struct gfs2_sbd *sdp, unsigned int blks)
  {
  
  	atomic_add(blks, &sdp->sd_log_blks_free);
  	trace_gfs2_log_blocks(sdp, blks);
  	gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <=
  				  sdp->sd_jdesc->jd_blocks);
  	up_read(&sdp->sd_log_flush_lock);
  }

  void gfs2_trans_end(struct gfs2_sbd *sdp)
  {

  	struct gfs2_trans *tr = current->journal_info;

  	BUG_ON(!tr);

  	current->journal_info = NULL;

  	if (!tr->tr_touched) {
  		gfs2_log_release(sdp, tr->tr_reserved);

  		if (tr->tr_t_gh.gh_gl) {
  			gfs2_glock_dq(&tr->tr_t_gh);
  			gfs2_holder_uninit(&tr->tr_t_gh);
  			kfree(tr);
  		}

  		return;
  	}

  	if (gfs2_assert_withdraw(sdp, tr->tr_num_buf <= tr->tr_blocks)) {
  		fs_err(sdp, "tr_num_buf = %u, tr_blocks = %u ",
  		       tr->tr_num_buf, tr->tr_blocks);
  		print_symbol(KERN_WARNING "GFS2: Transaction created at: %s
  ", tr->tr_ip);
  	}

  	if (gfs2_assert_withdraw(sdp, tr->tr_num_revoke <= tr->tr_revokes)) {

  		fs_err(sdp, "tr_num_revoke = %u, tr_revokes = %u ",
  		       tr->tr_num_revoke, tr->tr_revokes);
  		print_symbol(KERN_WARNING "GFS2: Transaction created at: %s
  ", tr->tr_ip);

  	}

  
  	gfs2_log_commit(sdp, tr);

  	if (tr->tr_t_gh.gh_gl) {
  		gfs2_glock_dq(&tr->tr_t_gh);
  		gfs2_holder_uninit(&tr->tr_t_gh);
  		kfree(tr);
  	}

  
  	if (sdp->sd_vfs->s_flags & MS_SYNCHRONOUS)

  		gfs2_log_flush(sdp, NULL);

  }

  /**
   * gfs2_trans_add_bh - Add a to-be-modified buffer to the current transaction
   * @gl: the glock the buffer belongs to
   * @bh: The buffer to add

   * @meta: True in the case of adding metadata

   *
   */

  void gfs2_trans_add_bh(struct gfs2_glock *gl, struct buffer_head *bh, int meta)

  {
  	struct gfs2_sbd *sdp = gl->gl_sbd;
  	struct gfs2_bufdata *bd;

  	bd = bh->b_private;

  	if (bd)
  		gfs2_assert(sdp, bd->bd_gl == gl);
  	else {

  		gfs2_attach_bufdata(gl, bh, meta);

  		bd = bh->b_private;

  	}

  	lops_add(sdp, &bd->bd_le);
  }

  void gfs2_trans_add_revoke(struct gfs2_sbd *sdp, struct gfs2_bufdata *bd)

  {

  	BUG_ON(!list_empty(&bd->bd_le.le_list));
  	BUG_ON(!list_empty(&bd->bd_ail_st_list));
  	BUG_ON(!list_empty(&bd->bd_ail_gl_list));

  	lops_init_le(&bd->bd_le, &gfs2_revoke_lops);

  	lops_add(sdp, &bd->bd_le);

  }

  void gfs2_trans_add_unrevoke(struct gfs2_sbd *sdp, u64 blkno, unsigned int len)

  {

  	struct gfs2_bufdata *bd, *tmp;
  	struct gfs2_trans *tr = current->journal_info;
  	unsigned int n = len;

  
  	gfs2_log_lock(sdp);

  	list_for_each_entry_safe(bd, tmp, &sdp->sd_log_le_revoke, bd_le.le_list) {
  		if ((bd->bd_blkno >= blkno) && (bd->bd_blkno < (blkno + len))) {

  			list_del_init(&bd->bd_le.le_list);

  			gfs2_assert_withdraw(sdp, sdp->sd_log_num_revoke);
  			sdp->sd_log_num_revoke--;

  			kmem_cache_free(gfs2_bufdata_cachep, bd);
  			tr->tr_num_revoke_rm++;
  			if (--n == 0)
  				break;

  		}
  	}

  	gfs2_log_unlock(sdp);

  }