/* -*- mode: c; c-basic-offset: 8; -*-
   * vim: noexpandtab sw=8 ts=8 sts=0:
   *
   * resize.c
   *
   * volume resize.
   * Inspired by ext3/resize.c.
   *
   * Copyright (C) 2007 Oracle.  All rights reserved.
   *
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of the GNU General Public
   * License as published by the Free Software Foundation; either
   * version 2 of the License, or (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * General Public License for more details.
   *
   * You should have received a copy of the GNU General Public
   * License along with this program; if not, write to the
   * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
   * Boston, MA 021110-1307, USA.
   */
  
  #include <linux/fs.h>
  #include <linux/types.h>

  #include <cluster/masklog.h>
  
  #include "ocfs2.h"
  
  #include "alloc.h"
  #include "dlmglue.h"
  #include "inode.h"
  #include "journal.h"
  #include "super.h"
  #include "sysfile.h"
  #include "uptodate.h"

  #include "ocfs2_trace.h"

  
  #include "buffer_head_io.h"
  #include "suballoc.h"
  #include "resize.h"
  
  /*
   * Check whether there are new backup superblocks exist
   * in the last group. If there are some, mark them or clear
   * them in the bitmap.
   *
   * Return how many backups we find in the last group.
   */
  static u16 ocfs2_calc_new_backup_super(struct inode *inode,
  				       struct ocfs2_group_desc *gd,
  				       int new_clusters,
  				       u32 first_new_cluster,
  				       u16 cl_cpg,
  				       int set)
  {
  	int i;
  	u16 backups = 0;
  	u32 cluster;
  	u64 blkno, gd_blkno, lgd_blkno = le64_to_cpu(gd->bg_blkno);
  
  	for (i = 0; i < OCFS2_MAX_BACKUP_SUPERBLOCKS; i++) {
  		blkno = ocfs2_backup_super_blkno(inode->i_sb, i);
  		cluster = ocfs2_blocks_to_clusters(inode->i_sb, blkno);
  
  		gd_blkno = ocfs2_which_cluster_group(inode, cluster);
  		if (gd_blkno < lgd_blkno)
  			continue;
  		else if (gd_blkno > lgd_blkno)
  			break;
  
  		if (set)
  			ocfs2_set_bit(cluster % cl_cpg,
  				      (unsigned long *)gd->bg_bitmap);
  		else
  			ocfs2_clear_bit(cluster % cl_cpg,
  					(unsigned long *)gd->bg_bitmap);
  		backups++;
  	}

  	return backups;
  }
  
  static int ocfs2_update_last_group_and_inode(handle_t *handle,
  					     struct inode *bm_inode,
  					     struct buffer_head *bm_bh,
  					     struct buffer_head *group_bh,
  					     u32 first_new_cluster,
  					     int new_clusters)
  {
  	int ret = 0;
  	struct ocfs2_super *osb = OCFS2_SB(bm_inode->i_sb);
  	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) bm_bh->b_data;
  	struct ocfs2_chain_list *cl = &fe->id2.i_chain;
  	struct ocfs2_chain_rec *cr;
  	struct ocfs2_group_desc *group;
  	u16 chain, num_bits, backups = 0;
  	u16 cl_bpc = le16_to_cpu(cl->cl_bpc);
  	u16 cl_cpg = le16_to_cpu(cl->cl_cpg);

  	trace_ocfs2_update_last_group_and_inode(new_clusters,
  						first_new_cluster);

  	ret = ocfs2_journal_access_gd(handle, INODE_CACHE(bm_inode),
  				      group_bh, OCFS2_JOURNAL_ACCESS_WRITE);

  	if (ret < 0) {
  		mlog_errno(ret);
  		goto out;
  	}
  
  	group = (struct ocfs2_group_desc *)group_bh->b_data;
  
  	/* update the group first. */
  	num_bits = new_clusters * cl_bpc;
  	le16_add_cpu(&group->bg_bits, num_bits);
  	le16_add_cpu(&group->bg_free_bits_count, num_bits);
  
  	/*
  	 * check whether there are some new backup superblocks exist in
  	 * this group and update the group bitmap accordingly.
  	 */
  	if (OCFS2_HAS_COMPAT_FEATURE(osb->sb,
  				     OCFS2_FEATURE_COMPAT_BACKUP_SB)) {
  		backups = ocfs2_calc_new_backup_super(bm_inode,
  						     group,
  						     new_clusters,
  						     first_new_cluster,
  						     cl_cpg, 1);
  		le16_add_cpu(&group->bg_free_bits_count, -1 * backups);
  	}

  	ocfs2_journal_dirty(handle, group_bh);

  
  	/* update the inode accordingly. */

  	ret = ocfs2_journal_access_di(handle, INODE_CACHE(bm_inode), bm_bh,

  				      OCFS2_JOURNAL_ACCESS_WRITE);

  	if (ret < 0) {
  		mlog_errno(ret);
  		goto out_rollback;
  	}
  
  	chain = le16_to_cpu(group->bg_chain);
  	cr = (&cl->cl_recs[chain]);
  	le32_add_cpu(&cr->c_total, num_bits);
  	le32_add_cpu(&cr->c_free, num_bits);
  	le32_add_cpu(&fe->id1.bitmap1.i_total, num_bits);
  	le32_add_cpu(&fe->i_clusters, new_clusters);
  
  	if (backups) {
  		le32_add_cpu(&cr->c_free, -1 * backups);
  		le32_add_cpu(&fe->id1.bitmap1.i_used, backups);
  	}
  
  	spin_lock(&OCFS2_I(bm_inode)->ip_lock);
  	OCFS2_I(bm_inode)->ip_clusters = le32_to_cpu(fe->i_clusters);
  	le64_add_cpu(&fe->i_size, new_clusters << osb->s_clustersize_bits);
  	spin_unlock(&OCFS2_I(bm_inode)->ip_lock);
  	i_size_write(bm_inode, le64_to_cpu(fe->i_size));
  
  	ocfs2_journal_dirty(handle, bm_bh);
  
  out_rollback:
  	if (ret < 0) {
  		ocfs2_calc_new_backup_super(bm_inode,
  					    group,
  					    new_clusters,
  					    first_new_cluster,
  					    cl_cpg, 0);
  		le16_add_cpu(&group->bg_free_bits_count, backups);
  		le16_add_cpu(&group->bg_bits, -1 * num_bits);
  		le16_add_cpu(&group->bg_free_bits_count, -1 * num_bits);
  	}
  out:

  	if (ret)
  		mlog_errno(ret);

  	return ret;
  }
  
  static int update_backups(struct inode * inode, u32 clusters, char *data)
  {
  	int i, ret = 0;
  	u32 cluster;
  	u64 blkno;
  	struct buffer_head *backup = NULL;
  	struct ocfs2_dinode *backup_di = NULL;
  	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
  
  	/* calculate the real backups we need to update. */
  	for (i = 0; i < OCFS2_MAX_BACKUP_SUPERBLOCKS; i++) {
  		blkno = ocfs2_backup_super_blkno(inode->i_sb, i);
  		cluster = ocfs2_blocks_to_clusters(inode->i_sb, blkno);
  		if (cluster > clusters)
  			break;

  		ret = ocfs2_read_blocks_sync(osb, blkno, 1, &backup);

  		if (ret < 0) {
  			mlog_errno(ret);
  			break;
  		}
  
  		memcpy(backup->b_data, data, inode->i_sb->s_blocksize);
  
  		backup_di = (struct ocfs2_dinode *)backup->b_data;
  		backup_di->i_blkno = cpu_to_le64(blkno);
  
  		ret = ocfs2_write_super_or_backup(osb, backup);
  		brelse(backup);
  		backup = NULL;
  		if (ret < 0) {
  			mlog_errno(ret);
  			break;
  		}
  	}
  
  	return ret;
  }
  
  static void ocfs2_update_super_and_backups(struct inode *inode,
  					   int new_clusters)
  {
  	int ret;
  	u32 clusters = 0;
  	struct buffer_head *super_bh = NULL;
  	struct ocfs2_dinode *super_di = NULL;
  	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
  
  	/*
  	 * update the superblock last.
  	 * It doesn't matter if the write failed.
  	 */

  	ret = ocfs2_read_blocks_sync(osb, OCFS2_SUPER_BLOCK_BLKNO, 1,
  				     &super_bh);

  	if (ret < 0) {
  		mlog_errno(ret);
  		goto out;
  	}
  
  	super_di = (struct ocfs2_dinode *)super_bh->b_data;
  	le32_add_cpu(&super_di->i_clusters, new_clusters);
  	clusters = le32_to_cpu(super_di->i_clusters);
  
  	ret = ocfs2_write_super_or_backup(osb, super_bh);
  	if (ret < 0) {
  		mlog_errno(ret);
  		goto out;
  	}
  
  	if (OCFS2_HAS_COMPAT_FEATURE(osb->sb, OCFS2_FEATURE_COMPAT_BACKUP_SB))
  		ret = update_backups(inode, clusters, super_bh->b_data);
  
  out:

  	brelse(super_bh);

  	if (ret)
  		printk(KERN_WARNING "ocfs2: Failed to update super blocks on %s"
  			" during fs resize. This condition is not fatal,"
  			" but fsck.ocfs2 should be run to fix it
  ",
  			osb->dev_str);
  	return;
  }
  
  /*
   * Extend the filesystem to the new number of clusters specified.  This entry
   * point is only used to extend the current filesystem to the end of the last
   * existing group.
   */
  int ocfs2_group_extend(struct inode * inode, int new_clusters)
  {
  	int ret;
  	handle_t *handle;
  	struct buffer_head *main_bm_bh = NULL;
  	struct buffer_head *group_bh = NULL;
  	struct inode *main_bm_inode = NULL;
  	struct ocfs2_dinode *fe = NULL;
  	struct ocfs2_group_desc *group = NULL;
  	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
  	u16 cl_bpc;
  	u32 first_new_cluster;
  	u64 lgd_blkno;

  	if (ocfs2_is_hard_readonly(osb) || ocfs2_is_soft_readonly(osb))
  		return -EROFS;
  
  	if (new_clusters < 0)
  		return -EINVAL;
  	else if (new_clusters == 0)
  		return 0;
  
  	main_bm_inode = ocfs2_get_system_file_inode(osb,
  						    GLOBAL_BITMAP_SYSTEM_INODE,
  						    OCFS2_INVALID_SLOT);
  	if (!main_bm_inode) {
  		ret = -EINVAL;
  		mlog_errno(ret);
  		goto out;
  	}
  
  	mutex_lock(&main_bm_inode->i_mutex);
  
  	ret = ocfs2_inode_lock(main_bm_inode, &main_bm_bh, 1);
  	if (ret < 0) {
  		mlog_errno(ret);
  		goto out_mutex;
  	}
  
  	fe = (struct ocfs2_dinode *)main_bm_bh->b_data;

  	/* main_bm_bh is validated by inode read inside ocfs2_inode_lock(),
  	 * so any corruption is a code bug. */
  	BUG_ON(!OCFS2_IS_VALID_DINODE(fe));

  	if (le16_to_cpu(fe->id2.i_chain.cl_cpg) !=

  		ocfs2_group_bitmap_size(osb->sb, 0,
  					osb->s_feature_incompat) * 8) {

  		mlog(ML_ERROR, "The disk is too old and small. "
  		     "Force to do offline resize.");
  		ret = -EINVAL;
  		goto out_unlock;

  	}
  
  	first_new_cluster = le32_to_cpu(fe->i_clusters);
  	lgd_blkno = ocfs2_which_cluster_group(main_bm_inode,
  					      first_new_cluster - 1);

  	ret = ocfs2_read_group_descriptor(main_bm_inode, fe, lgd_blkno,
  					  &group_bh);

  	if (ret < 0) {
  		mlog_errno(ret);
  		goto out_unlock;
  	}

  	group = (struct ocfs2_group_desc *)group_bh->b_data;

  	cl_bpc = le16_to_cpu(fe->id2.i_chain.cl_bpc);
  	if (le16_to_cpu(group->bg_bits) / cl_bpc + new_clusters >
  		le16_to_cpu(fe->id2.i_chain.cl_cpg)) {
  		ret = -EINVAL;
  		goto out_unlock;
  	}

  
  	trace_ocfs2_group_extend(

  	     (unsigned long long)le64_to_cpu(group->bg_blkno), new_clusters);

  
  	handle = ocfs2_start_trans(osb, OCFS2_GROUP_EXTEND_CREDITS);
  	if (IS_ERR(handle)) {
  		mlog_errno(PTR_ERR(handle));
  		ret = -EINVAL;
  		goto out_unlock;
  	}
  
  	/* update the last group descriptor and inode. */
  	ret = ocfs2_update_last_group_and_inode(handle, main_bm_inode,
  						main_bm_bh, group_bh,
  						first_new_cluster,
  						new_clusters);
  	if (ret) {
  		mlog_errno(ret);
  		goto out_commit;
  	}
  
  	ocfs2_update_super_and_backups(main_bm_inode, new_clusters);
  
  out_commit:
  	ocfs2_commit_trans(osb, handle);
  out_unlock:

  	brelse(group_bh);
  	brelse(main_bm_bh);

  
  	ocfs2_inode_unlock(main_bm_inode, 1);
  
  out_mutex:
  	mutex_unlock(&main_bm_inode->i_mutex);
  	iput(main_bm_inode);
  
  out:

  	return ret;
  }

  
  static int ocfs2_check_new_group(struct inode *inode,
  				 struct ocfs2_dinode *di,
  				 struct ocfs2_new_group_input *input,
  				 struct buffer_head *group_bh)
  {
  	int ret;

  	struct ocfs2_group_desc *gd =
  		(struct ocfs2_group_desc *)group_bh->b_data;

  	u16 cl_bpc = le16_to_cpu(di->id2.i_chain.cl_bpc);

  	ret = ocfs2_check_group_descriptor(inode->i_sb, di, group_bh);

  	if (ret)
  		goto out;

  	ret = -EINVAL;
  	if (le16_to_cpu(gd->bg_chain) != input->chain)

  		mlog(ML_ERROR, "Group descriptor # %llu has bad chain %u "
  		     "while input has %u set.
  ",
  		     (unsigned long long)le64_to_cpu(gd->bg_blkno),
  		     le16_to_cpu(gd->bg_chain), input->chain);
  	else if (le16_to_cpu(gd->bg_bits) != input->clusters * cl_bpc)
  		mlog(ML_ERROR, "Group descriptor # %llu has bit count %u but "
  		     "input has %u clusters set
  ",
  		     (unsigned long long)le64_to_cpu(gd->bg_blkno),
  		     le16_to_cpu(gd->bg_bits), input->clusters);
  	else if (le16_to_cpu(gd->bg_free_bits_count) != input->frees * cl_bpc)
  		mlog(ML_ERROR, "Group descriptor # %llu has free bit count %u "
  		     "but it should have %u set
  ",
  		     (unsigned long long)le64_to_cpu(gd->bg_blkno),
  		     le16_to_cpu(gd->bg_bits),
  		     input->frees * cl_bpc);
  	else
  		ret = 0;

  out:

  	return ret;
  }
  
  static int ocfs2_verify_group_and_input(struct inode *inode,
  					struct ocfs2_dinode *di,
  					struct ocfs2_new_group_input *input,
  					struct buffer_head *group_bh)
  {
  	u16 cl_count = le16_to_cpu(di->id2.i_chain.cl_count);
  	u16 cl_cpg = le16_to_cpu(di->id2.i_chain.cl_cpg);
  	u16 next_free = le16_to_cpu(di->id2.i_chain.cl_next_free_rec);
  	u32 cluster = ocfs2_blocks_to_clusters(inode->i_sb, input->group);
  	u32 total_clusters = le32_to_cpu(di->i_clusters);
  	int ret = -EINVAL;
  
  	if (cluster < total_clusters)
  		mlog(ML_ERROR, "add a group which is in the current volume.
  ");
  	else if (input->chain >= cl_count)
  		mlog(ML_ERROR, "input chain exceeds the limit.
  ");
  	else if (next_free != cl_count && next_free != input->chain)
  		mlog(ML_ERROR,
  		     "the add group should be in chain %u
  ", next_free);
  	else if (total_clusters + input->clusters < total_clusters)
  		mlog(ML_ERROR, "add group's clusters overflow.
  ");
  	else if (input->clusters > cl_cpg)
  		mlog(ML_ERROR, "the cluster exceeds the maximum of a group
  ");
  	else if (input->frees > input->clusters)
  		mlog(ML_ERROR, "the free cluster exceeds the total clusters
  ");
  	else if (total_clusters % cl_cpg != 0)
  		mlog(ML_ERROR,
  		     "the last group isn't full. Use group extend first.
  ");
  	else if (input->group != ocfs2_which_cluster_group(inode, cluster))
  		mlog(ML_ERROR, "group blkno is invalid
  ");
  	else if ((ret = ocfs2_check_new_group(inode, di, input, group_bh)))
  		mlog(ML_ERROR, "group descriptor check failed.
  ");
  	else
  		ret = 0;
  
  	return ret;
  }
  
  /* Add a new group descriptor to global_bitmap. */
  int ocfs2_group_add(struct inode *inode, struct ocfs2_new_group_input *input)
  {
  	int ret;
  	handle_t *handle;
  	struct buffer_head *main_bm_bh = NULL;
  	struct inode *main_bm_inode = NULL;
  	struct ocfs2_dinode *fe = NULL;
  	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
  	struct buffer_head *group_bh = NULL;
  	struct ocfs2_group_desc *group = NULL;
  	struct ocfs2_chain_list *cl;
  	struct ocfs2_chain_rec *cr;
  	u16 cl_bpc;

  	if (ocfs2_is_hard_readonly(osb) || ocfs2_is_soft_readonly(osb))
  		return -EROFS;
  
  	main_bm_inode = ocfs2_get_system_file_inode(osb,
  						    GLOBAL_BITMAP_SYSTEM_INODE,
  						    OCFS2_INVALID_SLOT);
  	if (!main_bm_inode) {
  		ret = -EINVAL;
  		mlog_errno(ret);
  		goto out;
  	}
  
  	mutex_lock(&main_bm_inode->i_mutex);
  
  	ret = ocfs2_inode_lock(main_bm_inode, &main_bm_bh, 1);
  	if (ret < 0) {
  		mlog_errno(ret);
  		goto out_mutex;
  	}
  
  	fe = (struct ocfs2_dinode *)main_bm_bh->b_data;
  
  	if (le16_to_cpu(fe->id2.i_chain.cl_cpg) !=

  		ocfs2_group_bitmap_size(osb->sb, 0,
  					osb->s_feature_incompat) * 8) {

  		mlog(ML_ERROR, "The disk is too old and small."
  		     " Force to do offline resize.");
  		ret = -EINVAL;
  		goto out_unlock;
  	}

  	ret = ocfs2_read_blocks_sync(osb, input->group, 1, &group_bh);

  	if (ret < 0) {
  		mlog(ML_ERROR, "Can't read the group descriptor # %llu "
  		     "from the device.", (unsigned long long)input->group);
  		goto out_unlock;
  	}

  	ocfs2_set_new_buffer_uptodate(INODE_CACHE(inode), group_bh);

  
  	ret = ocfs2_verify_group_and_input(main_bm_inode, fe, input, group_bh);
  	if (ret) {
  		mlog_errno(ret);
  		goto out_unlock;
  	}

  	trace_ocfs2_group_add((unsigned long long)input->group,
  			       input->chain, input->clusters, input->frees);

  
  	handle = ocfs2_start_trans(osb, OCFS2_GROUP_ADD_CREDITS);
  	if (IS_ERR(handle)) {
  		mlog_errno(PTR_ERR(handle));
  		ret = -EINVAL;
  		goto out_unlock;
  	}
  
  	cl_bpc = le16_to_cpu(fe->id2.i_chain.cl_bpc);
  	cl = &fe->id2.i_chain;
  	cr = &cl->cl_recs[input->chain];

  	ret = ocfs2_journal_access_gd(handle, INODE_CACHE(main_bm_inode),
  				      group_bh, OCFS2_JOURNAL_ACCESS_WRITE);

  	if (ret < 0) {
  		mlog_errno(ret);
  		goto out_commit;
  	}
  
  	group = (struct ocfs2_group_desc *)group_bh->b_data;
  	group->bg_next_group = cr->c_blkno;

  	ocfs2_journal_dirty(handle, group_bh);

  	ret = ocfs2_journal_access_di(handle, INODE_CACHE(main_bm_inode),
  				      main_bm_bh, OCFS2_JOURNAL_ACCESS_WRITE);

  	if (ret < 0) {
  		mlog_errno(ret);
  		goto out_commit;
  	}
  
  	if (input->chain == le16_to_cpu(cl->cl_next_free_rec)) {
  		le16_add_cpu(&cl->cl_next_free_rec, 1);
  		memset(cr, 0, sizeof(struct ocfs2_chain_rec));
  	}

  	cr->c_blkno = cpu_to_le64(input->group);

  	le32_add_cpu(&cr->c_total, input->clusters * cl_bpc);
  	le32_add_cpu(&cr->c_free, input->frees * cl_bpc);
  
  	le32_add_cpu(&fe->id1.bitmap1.i_total, input->clusters *cl_bpc);
  	le32_add_cpu(&fe->id1.bitmap1.i_used,
  		     (input->clusters - input->frees) * cl_bpc);
  	le32_add_cpu(&fe->i_clusters, input->clusters);
  
  	ocfs2_journal_dirty(handle, main_bm_bh);
  
  	spin_lock(&OCFS2_I(main_bm_inode)->ip_lock);
  	OCFS2_I(main_bm_inode)->ip_clusters = le32_to_cpu(fe->i_clusters);
  	le64_add_cpu(&fe->i_size, input->clusters << osb->s_clustersize_bits);
  	spin_unlock(&OCFS2_I(main_bm_inode)->ip_lock);
  	i_size_write(main_bm_inode, le64_to_cpu(fe->i_size));
  
  	ocfs2_update_super_and_backups(main_bm_inode, input->clusters);
  
  out_commit:
  	ocfs2_commit_trans(osb, handle);
  out_unlock:

  	brelse(group_bh);
  	brelse(main_bm_bh);

  
  	ocfs2_inode_unlock(main_bm_inode, 1);
  
  out_mutex:
  	mutex_unlock(&main_bm_inode->i_mutex);
  	iput(main_bm_inode);
  
  out:

  	return ret;
  }