/*
   * 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.

   */

  #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

  #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 "inode.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 = _RET_IP_;

  	tr->tr_blocks = blocks;
  	tr->tr_revokes = revokes;
  	tr->tr_reserved = 1;

  	tr->tr_alloced = 1;

  	if (blocks)

  		tr->tr_reserved += 6 + blocks;

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

  						   sizeof(u64));

  	INIT_LIST_HEAD(&tr->tr_databuf);
  	INIT_LIST_HEAD(&tr->tr_buf);

  	sb_start_intwrite(sdp->sd_vfs);

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

  		goto fail;

  	current->journal_info = tr;

  
  	return 0;

  fail:

  	sb_end_intwrite(sdp->sd_vfs);

  	kfree(tr);
  
  	return error;
  }

  static void gfs2_print_trans(const struct gfs2_trans *tr)
  {

  	pr_warn("Transaction created at: %pSR
  ", (void *)tr->tr_ip);
  	pr_warn("blocks=%u revokes=%u reserved=%u touched=%u
  ",
  		tr->tr_blocks, tr->tr_revokes, tr->tr_reserved, tr->tr_touched);
  	pr_warn("Buf %u/%u Databuf %u/%u Revoke %u/%u
  ",
  		tr->tr_num_buf_new, tr->tr_num_buf_rm,
  		tr->tr_num_databuf_new, tr->tr_num_databuf_rm,
  		tr->tr_num_revoke, tr->tr_num_revoke_rm);

  }

  void gfs2_trans_end(struct gfs2_sbd *sdp)
  {

  	struct gfs2_trans *tr = current->journal_info;

  	s64 nbuf;

  	int alloced = tr->tr_alloced;

  	BUG_ON(!tr);

  	current->journal_info = NULL;

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

  		if (alloced) {

  			kfree(tr);

  			sb_end_intwrite(sdp->sd_vfs);
  		}

  		return;
  	}

  	nbuf = tr->tr_num_buf_new + tr->tr_num_databuf_new;
  	nbuf -= tr->tr_num_buf_rm;
  	nbuf -= tr->tr_num_databuf_rm;
  
  	if (gfs2_assert_withdraw(sdp, (nbuf <= tr->tr_blocks) &&
  				       (tr->tr_num_revoke <= tr->tr_revokes)))
  		gfs2_print_trans(tr);

  
  	gfs2_log_commit(sdp, tr);

  	if (alloced && !tr->tr_attached)

  			kfree(tr);

  	up_read(&sdp->sd_log_flush_lock);

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

  		gfs2_log_flush(sdp, NULL, NORMAL_FLUSH);

  	if (alloced)
  		sb_end_intwrite(sdp->sd_vfs);

  }

  static struct gfs2_bufdata *gfs2_alloc_bufdata(struct gfs2_glock *gl,
  					       struct buffer_head *bh,
  					       const struct gfs2_log_operations *lops)
  {
  	struct gfs2_bufdata *bd;
  
  	bd = kmem_cache_zalloc(gfs2_bufdata_cachep, GFP_NOFS | __GFP_NOFAIL);
  	bd->bd_bh = bh;
  	bd->bd_gl = gl;
  	bd->bd_ops = lops;
  	INIT_LIST_HEAD(&bd->bd_list);
  	bh->b_private = bd;
  	return bd;
  }

  /**

   * gfs2_trans_add_data - Add a databuf to the transaction.
   * @gl: The inode glock associated with the buffer
   * @bh: The buffer to add

   *

   * This is used in two distinct cases:
   * i) In ordered write mode
   *    We put the data buffer on a list so that we can ensure that its
   *    synced to disk at the right time
   * ii) In journaled data mode
   *    We need to journal the data block in the same way as metadata in
   *    the functions above. The difference is that here we have a tag
   *    which is two __be64's being the block number (as per meta data)
   *    and a flag which says whether the data block needs escaping or
   *    not. This means we need a new log entry for each 251 or so data
   *    blocks, which isn't an enormous overhead but twice as much as
   *    for normal metadata blocks.

   */

  void gfs2_trans_add_data(struct gfs2_glock *gl, struct buffer_head *bh)

  {
  	struct gfs2_trans *tr = current->journal_info;

  	struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;

  	struct address_space *mapping = bh->b_page->mapping;

  	struct gfs2_inode *ip = GFS2_I(mapping->host);

  	struct gfs2_bufdata *bd;

  	if (!gfs2_is_jdata(ip)) {
  		gfs2_ordered_add_inode(ip);

  		return;

  	}

  	lock_buffer(bh);
  	gfs2_log_lock(sdp);

  	bd = bh->b_private;

  	if (bd == NULL) {

  		gfs2_log_unlock(sdp);
  		unlock_buffer(bh);

  		if (bh->b_private == NULL)
  			bd = gfs2_alloc_bufdata(gl, bh, &gfs2_databuf_lops);

  		else
  			bd = bh->b_private;

  		lock_buffer(bh);
  		gfs2_log_lock(sdp);

  	}

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

  	tr->tr_touched = 1;
  	if (list_empty(&bd->bd_list)) {
  		set_bit(GLF_LFLUSH, &bd->bd_gl->gl_flags);
  		set_bit(GLF_DIRTY, &bd->bd_gl->gl_flags);
  		gfs2_pin(sdp, bd->bd_bh);
  		tr->tr_num_databuf_new++;

  		list_add_tail(&bd->bd_list, &tr->tr_databuf);

  	}

  	gfs2_log_unlock(sdp);
  	unlock_buffer(bh);

  }

  static void meta_lo_add(struct gfs2_sbd *sdp, struct gfs2_bufdata *bd)

  {

  	struct gfs2_meta_header *mh;
  	struct gfs2_trans *tr;

  	enum gfs2_freeze_state state = atomic_read(&sdp->sd_freeze_state);

  
  	tr = current->journal_info;
  	tr->tr_touched = 1;
  	if (!list_empty(&bd->bd_list))
  		return;
  	set_bit(GLF_LFLUSH, &bd->bd_gl->gl_flags);
  	set_bit(GLF_DIRTY, &bd->bd_gl->gl_flags);
  	mh = (struct gfs2_meta_header *)bd->bd_bh->b_data;
  	if (unlikely(mh->mh_magic != cpu_to_be32(GFS2_MAGIC))) {

  		pr_err("Attempting to add uninitialised block to journal (inplace block=%lld)
  ",

  		       (unsigned long long)bd->bd_bh->b_blocknr);
  		BUG();
  	}

  	if (unlikely(state == SFS_FROZEN)) {
  		printk(KERN_INFO "GFS2:adding buf while frozen
  ");
  		gfs2_assert_withdraw(sdp, 0);
  	}

  	gfs2_pin(sdp, bd->bd_bh);
  	mh->__pad0 = cpu_to_be64(0);
  	mh->mh_jid = cpu_to_be32(sdp->sd_jdesc->jd_jid);

  	list_add(&bd->bd_list, &tr->tr_buf);

  	tr->tr_num_buf_new++;

  }
  
  void gfs2_trans_add_meta(struct gfs2_glock *gl, struct buffer_head *bh)
  {

  	struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;

  	struct gfs2_bufdata *bd;
  
  	lock_buffer(bh);
  	gfs2_log_lock(sdp);
  	bd = bh->b_private;

  	if (bd == NULL) {

  		gfs2_log_unlock(sdp);
  		unlock_buffer(bh);

  		lock_page(bh->b_page);
  		if (bh->b_private == NULL)
  			bd = gfs2_alloc_bufdata(gl, bh, &gfs2_buf_lops);

  		else
  			bd = bh->b_private;

  		unlock_page(bh->b_page);

  		lock_buffer(bh);
  		gfs2_log_lock(sdp);
  	}

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

  	meta_lo_add(sdp, bd);
  	gfs2_log_unlock(sdp);
  	unlock_buffer(bh);

  }

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

  {

  	struct gfs2_trans *tr = current->journal_info;

  	BUG_ON(!list_empty(&bd->bd_list));

  	gfs2_add_revoke(sdp, bd);

  	tr->tr_touched = 1;
  	tr->tr_num_revoke++;

  }

  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_list) {

  		if ((bd->bd_blkno >= blkno) && (bd->bd_blkno < (blkno + len))) {

  			list_del_init(&bd->bd_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);

  }