/fs/ocfs2/alloc.c

/* -*- mode: c; c-basic-offset: 8; -*-
 * vim: noexpandtab sw=8 ts=8 sts=0:
 *
 * alloc.c
 *
 * Extent allocs and frees
 *
 * Copyright (C) 2002, 2004 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 <linux/slab.h>
#include <linux/highmem.h>
#include <linux/swap.h>
#include <linux/quotaops.h>
#include <linux/blkdev.h>

#include <cluster/masklog.h>

#include "ocfs2.h"

#include "alloc.h"
#include "aops.h"
#include "blockcheck.h"
#include "dlmglue.h"
#include "extent_map.h"
#include "inode.h"
#include "journal.h"
#include "localalloc.h"
#include "suballoc.h"
#include "sysfile.h"
#include "file.h"
#include "super.h"
#include "uptodate.h"
#include "xattr.h"
#include "refcounttree.h"
#include "ocfs2_trace.h"

#include "buffer_head_io.h"

enum ocfs2_contig_type {
	CONTIG_NONE = 0,
	CONTIG_LEFT,
	CONTIG_RIGHT,
	CONTIG_LEFTRIGHT,
};

static enum ocfs2_contig_type
	ocfs2_extent_rec_contig(struct super_block *sb,
				struct ocfs2_extent_rec *ext,
				struct ocfs2_extent_rec *insert_rec);
struct ocfs2_extent_tree_operations {
	void (*eo_set_last_eb_blk)(struct ocfs2_extent_tree *et,
				   u64 blkno);
	u64 (*eo_get_last_eb_blk)(struct ocfs2_extent_tree *et);

	void (*eo_update_clusters)(struct ocfs2_extent_tree *et,
				   u32 new_clusters);

	void (*eo_extent_map_insert)(struct ocfs2_extent_tree *et,
				     struct ocfs2_extent_rec *rec);

	void (*eo_extent_map_truncate)(struct ocfs2_extent_tree *et,
				       u32 clusters);

	int (*eo_insert_check)(struct ocfs2_extent_tree *et,
			       struct ocfs2_extent_rec *rec);
	int (*eo_sanity_check)(struct ocfs2_extent_tree *et);


	void (*eo_fill_root_el)(struct ocfs2_extent_tree *et);

	void (*eo_fill_max_leaf_clusters)(struct ocfs2_extent_tree *et);

	enum ocfs2_contig_type
		(*eo_extent_contig)(struct ocfs2_extent_tree *et,
				    struct ocfs2_extent_rec *ext,
				    struct ocfs2_extent_rec *insert_rec);
};


static u64 ocfs2_dinode_get_last_eb_blk(struct ocfs2_extent_tree *et);
static void ocfs2_dinode_set_last_eb_blk(struct ocfs2_extent_tree *et,
					 u64 blkno);
static void ocfs2_dinode_update_clusters(struct ocfs2_extent_tree *et,
					 u32 clusters);
static void ocfs2_dinode_extent_map_insert(struct ocfs2_extent_tree *et,
					   struct ocfs2_extent_rec *rec);
static void ocfs2_dinode_extent_map_truncate(struct ocfs2_extent_tree *et,
					     u32 clusters);
static int ocfs2_dinode_insert_check(struct ocfs2_extent_tree *et,
				     struct ocfs2_extent_rec *rec);
static int ocfs2_dinode_sanity_check(struct ocfs2_extent_tree *et);
static void ocfs2_dinode_fill_root_el(struct ocfs2_extent_tree *et);
static struct ocfs2_extent_tree_operations ocfs2_dinode_et_ops = {
	.eo_set_last_eb_blk	= ocfs2_dinode_set_last_eb_blk,
	.eo_get_last_eb_blk	= ocfs2_dinode_get_last_eb_blk,
	.eo_update_clusters	= ocfs2_dinode_update_clusters,
	.eo_extent_map_insert	= ocfs2_dinode_extent_map_insert,
	.eo_extent_map_truncate	= ocfs2_dinode_extent_map_truncate,
	.eo_insert_check	= ocfs2_dinode_insert_check,
	.eo_sanity_check	= ocfs2_dinode_sanity_check,
	.eo_fill_root_el	= ocfs2_dinode_fill_root_el,
};

static void ocfs2_dinode_set_last_eb_blk(struct ocfs2_extent_tree *et,
					 u64 blkno)
{
	struct ocfs2_dinode *di = et->et_object;

	BUG_ON(et->et_ops != &ocfs2_dinode_et_ops);
	di->i_last_eb_blk = cpu_to_le64(blkno);
}

static u64 ocfs2_dinode_get_last_eb_blk(struct ocfs2_extent_tree *et)
{
	struct ocfs2_dinode *di = et->et_object;

	BUG_ON(et->et_ops != &ocfs2_dinode_et_ops);
	return le64_to_cpu(di->i_last_eb_blk);
}

static void ocfs2_dinode_update_clusters(struct ocfs2_extent_tree *et,
					 u32 clusters)
{
	struct ocfs2_inode_info *oi = cache_info_to_inode(et->et_ci);
	struct ocfs2_dinode *di = et->et_object;

	le32_add_cpu(&di->i_clusters, clusters);
	spin_lock(&oi->ip_lock);
	oi->ip_clusters = le32_to_cpu(di->i_clusters);
	spin_unlock(&oi->ip_lock);
}

static void ocfs2_dinode_extent_map_insert(struct ocfs2_extent_tree *et,
					   struct ocfs2_extent_rec *rec)
{
	struct inode *inode = &cache_info_to_inode(et->et_ci)->vfs_inode;

	ocfs2_extent_map_insert_rec(inode, rec);
}

static void ocfs2_dinode_extent_map_truncate(struct ocfs2_extent_tree *et,
					     u32 clusters)
{
	struct inode *inode = &cache_info_to_inode(et->et_ci)->vfs_inode;

	ocfs2_extent_map_trunc(inode, clusters);
}

static int ocfs2_dinode_insert_check(struct ocfs2_extent_tree *et,
				     struct ocfs2_extent_rec *rec)
{
	struct ocfs2_inode_info *oi = cache_info_to_inode(et->et_ci);
	struct ocfs2_super *osb = OCFS2_SB(oi->vfs_inode.i_sb);

	BUG_ON(oi->ip_dyn_features & OCFS2_INLINE_DATA_FL);
	mlog_bug_on_msg(!ocfs2_sparse_alloc(osb) &&
			(oi->ip_clusters != le32_to_cpu(rec->e_cpos)),
			"Device %s, asking for sparse allocation: inode %llu, "
			"cpos %u, clusters %u\n",
			osb->dev_str,
			(unsigned long long)oi->ip_blkno,
			rec->e_cpos, oi->ip_clusters);

	return 0;
}

static int ocfs2_dinode_sanity_check(struct ocfs2_extent_tree *et)
{
	struct ocfs2_dinode *di = et->et_object;

	BUG_ON(et->et_ops != &ocfs2_dinode_et_ops);
	BUG_ON(!OCFS2_IS_VALID_DINODE(di));

	return 0;
}

static void ocfs2_dinode_fill_root_el(struct ocfs2_extent_tree *et)
{
	struct ocfs2_dinode *di = et->et_object;

	et->et_root_el = &di->id2.i_list;
}


static void ocfs2_xattr_value_fill_root_el(struct ocfs2_extent_tree *et)
{
	struct ocfs2_xattr_value_buf *vb = et->et_object;

	et->et_root_el = &vb->vb_xv->xr_list;
}

static void ocfs2_xattr_value_set_last_eb_blk(struct ocfs2_extent_tree *et,
					      u64 blkno)
{
	struct ocfs2_xattr_value_buf *vb = et->et_object;

	vb->vb_xv->xr_last_eb_blk = cpu_to_le64(blkno);
}

static u64 ocfs2_xattr_value_get_last_eb_blk(struct ocfs2_extent_tree *et)
{
	struct ocfs2_xattr_value_buf *vb = et->et_object;

	return le64_to_cpu(vb->vb_xv->xr_last_eb_blk);
}

static void ocfs2_xattr_value_update_clusters(struct ocfs2_extent_tree *et,
					      u32 clusters)
{
	struct ocfs2_xattr_value_buf *vb = et->et_object;

	le32_add_cpu(&vb->vb_xv->xr_clusters, clusters);
}

static struct ocfs2_extent_tree_operations ocfs2_xattr_value_et_ops = {
	.eo_set_last_eb_blk	= ocfs2_xattr_value_set_last_eb_blk,
	.eo_get_last_eb_blk	= ocfs2_xattr_value_get_last_eb_blk,
	.eo_update_clusters	= ocfs2_xattr_value_update_clusters,
	.eo_fill_root_el	= ocfs2_xattr_value_fill_root_el,
};

static void ocfs2_xattr_tree_fill_root_el(struct ocfs2_extent_tree *et)
{
	struct ocfs2_xattr_block *xb = et->et_object;

	et->et_root_el = &xb->xb_attrs.xb_root.xt_list;
}

static void ocfs2_xattr_tree_fill_max_leaf_clusters(struct ocfs2_extent_tree *et)
{
	struct super_block *sb = ocfs2_metadata_cache_get_super(et->et_ci);
	et->et_max_leaf_clusters =
		ocfs2_clusters_for_bytes(sb, OCFS2_MAX_XATTR_TREE_LEAF_SIZE);
}

static void ocfs2_xattr_tree_set_last_eb_blk(struct ocfs2_extent_tree *et,
					     u64 blkno)
{
	struct ocfs2_xattr_block *xb = et->et_object;
	struct ocfs2_xattr_tree_root *xt = &xb->xb_attrs.xb_root;

	xt->xt_last_eb_blk = cpu_to_le64(blkno);
}

static u64 ocfs2_xattr_tree_get_last_eb_blk(struct ocfs2_extent_tree *et)
{
	struct ocfs2_xattr_block *xb = et->et_object;
	struct ocfs2_xattr_tree_root *xt = &xb->xb_attrs.xb_root;

	return le64_to_cpu(xt->xt_last_eb_blk);
}

static void ocfs2_xattr_tree_update_clusters(struct ocfs2_extent_tree *et,
					     u32 clusters)
{
	struct ocfs2_xattr_block *xb = et->et_object;

	le32_add_cpu(&xb->xb_attrs.xb_root.xt_clusters, clusters);
}

static struct ocfs2_extent_tree_operations ocfs2_xattr_tree_et_ops = {
	.eo_set_last_eb_blk	= ocfs2_xattr_tree_set_last_eb_blk,
	.eo_get_last_eb_blk	= ocfs2_xattr_tree_get_last_eb_blk,
	.eo_update_clusters	= ocfs2_xattr_tree_update_clusters,
	.eo_fill_root_el	= ocfs2_xattr_tree_fill_root_el,
	.eo_fill_max_leaf_clusters = ocfs2_xattr_tree_fill_max_leaf_clusters,
};

static void ocfs2_dx_root_set_last_eb_blk(struct ocfs2_extent_tree *et,
					  u64 blkno)
{
	struct ocfs2_dx_root_block *dx_root = et->et_object;

	dx_root->dr_last_eb_blk = cpu_to_le64(blkno);
}

static u64 ocfs2_dx_root_get_last_eb_blk(struct ocfs2_extent_tree *et)
{
	struct ocfs2_dx_root_block *dx_root = et->et_object;

	return le64_to_cpu(dx_root->dr_last_eb_blk);
}

static void ocfs2_dx_root_update_clusters(struct ocfs2_extent_tree *et,
					  u32 clusters)
{
	struct ocfs2_dx_root_block *dx_root = et->et_object;

	le32_add_cpu(&dx_root->dr_clusters, clusters);
}

static int ocfs2_dx_root_sanity_check(struct ocfs2_extent_tree *et)
{
	struct ocfs2_dx_root_block *dx_root = et->et_object;

	BUG_ON(!OCFS2_IS_VALID_DX_ROOT(dx_root));

	return 0;
}

static void ocfs2_dx_root_fill_root_el(struct ocfs2_extent_tree *et)
{
	struct ocfs2_dx_root_block *dx_root = et->et_object;

	et->et_root_el = &dx_root->dr_list;
}

static struct ocfs2_extent_tree_operations ocfs2_dx_root_et_ops = {
	.eo_set_last_eb_blk	= ocfs2_dx_root_set_last_eb_blk,
	.eo_get_last_eb_blk	= ocfs2_dx_root_get_last_eb_blk,
	.eo_update_clusters	= ocfs2_dx_root_update_clusters,
	.eo_sanity_check	= ocfs2_dx_root_sanity_check,
	.eo_fill_root_el	= ocfs2_dx_root_fill_root_el,
};

static void ocfs2_refcount_tree_fill_root_el(struct ocfs2_extent_tree *et)
{
	struct ocfs2_refcount_block *rb = et->et_object;

	et->et_root_el = &rb->rf_list;
}

static void ocfs2_refcount_tree_set_last_eb_blk(struct ocfs2_extent_tree *et,
						u64 blkno)
{
	struct ocfs2_refcount_block *rb = et->et_object;

	rb->rf_last_eb_blk = cpu_to_le64(blkno);
}

static u64 ocfs2_refcount_tree_get_last_eb_blk(struct ocfs2_extent_tree *et)
{
	struct ocfs2_refcount_block *rb = et->et_object;

	return le64_to_cpu(rb->rf_last_eb_blk);
}

static void ocfs2_refcount_tree_update_clusters(struct ocfs2_extent_tree *et,
						u32 clusters)
{
	struct ocfs2_refcount_block *rb = et->et_object;

	le32_add_cpu(&rb->rf_clusters, clusters);
}

static enum ocfs2_contig_type
ocfs2_refcount_tree_extent_contig(struct ocfs2_extent_tree *et,
				  struct ocfs2_extent_rec *ext,
				  struct ocfs2_extent_rec *insert_rec)
{
	return CONTIG_NONE;
}

static struct ocfs2_extent_tree_operations ocfs2_refcount_tree_et_ops = {
	.eo_set_last_eb_blk	= ocfs2_refcount_tree_set_last_eb_blk,
	.eo_get_last_eb_blk	= ocfs2_refcount_tree_get_last_eb_blk,
	.eo_update_clusters	= ocfs2_refcount_tree_update_clusters,
	.eo_fill_root_el	= ocfs2_refcount_tree_fill_root_el,
	.eo_extent_contig	= ocfs2_refcount_tree_extent_contig,
};

static void __ocfs2_init_extent_tree(struct ocfs2_extent_tree *et,
				     struct ocfs2_caching_info *ci,
				     struct buffer_head *bh,
				     ocfs2_journal_access_func access,
				     void *obj,
				     struct ocfs2_extent_tree_operations *ops)
{
	et->et_ops = ops;
	et->et_root_bh = bh;
	et->et_ci = ci;
	et->et_root_journal_access = access;
	if (!obj)
		obj = (void *)bh->b_data;
	et->et_object = obj;

	et->et_ops->eo_fill_root_el(et);
	if (!et->et_ops->eo_fill_max_leaf_clusters)
		et->et_max_leaf_clusters = 0;
	else
		et->et_ops->eo_fill_max_leaf_clusters(et);
}

void ocfs2_init_dinode_extent_tree(struct ocfs2_extent_tree *et,
				   struct ocfs2_caching_info *ci,
				   struct buffer_head *bh)
{
	__ocfs2_init_extent_tree(et, ci, bh, ocfs2_journal_access_di,
				 NULL, &ocfs2_dinode_et_ops);
}

void ocfs2_init_xattr_tree_extent_tree(struct ocfs2_extent_tree *et,
				       struct ocfs2_caching_info *ci,
				       struct buffer_head *bh)
{
	__ocfs2_init_extent_tree(et, ci, bh, ocfs2_journal_access_xb,
				 NULL, &ocfs2_xattr_tree_et_ops);
}

void ocfs2_init_xattr_value_extent_tree(struct ocfs2_extent_tree *et,
					struct ocfs2_caching_info *ci,
					struct ocfs2_xattr_value_buf *vb)
{
	__ocfs2_init_extent_tree(et, ci, vb->vb_bh, vb->vb_access, vb,
				 &ocfs2_xattr_value_et_ops);
}

void ocfs2_init_dx_root_extent_tree(struct ocfs2_extent_tree *et,
				    struct ocfs2_caching_info *ci,
				    struct buffer_head *bh)
{
	__ocfs2_init_extent_tree(et, ci, bh, ocfs2_journal_access_dr,
				 NULL, &ocfs2_dx_root_et_ops);
}

void ocfs2_init_refcount_extent_tree(struct ocfs2_extent_tree *et,
				     struct ocfs2_caching_info *ci,
				     struct buffer_head *bh)
{
	__ocfs2_init_extent_tree(et, ci, bh, ocfs2_journal_access_rb,
				 NULL, &ocfs2_refcount_tree_et_ops);
}

static inline void ocfs2_et_set_last_eb_blk(struct ocfs2_extent_tree *et,
					    u64 new_last_eb_blk)
{
	et->et_ops->eo_set_last_eb_blk(et, new_last_eb_blk);
}

static inline u64 ocfs2_et_get_last_eb_blk(struct ocfs2_extent_tree *et)
{
	return et->et_ops->eo_get_last_eb_blk(et);
}

static inline void ocfs2_et_update_clusters(struct ocfs2_extent_tree *et,
					    u32 clusters)
{
	et->et_ops->eo_update_clusters(et, clusters);
}

static inline void ocfs2_et_extent_map_insert(struct ocfs2_extent_tree *et,
					      struct ocfs2_extent_rec *rec)
{
	if (et->et_ops->eo_extent_map_insert)
		et->et_ops->eo_extent_map_insert(et, rec);
}

static inline void ocfs2_et_extent_map_truncate(struct ocfs2_extent_tree *et,
						u32 clusters)
{
	if (et->et_ops->eo_extent_map_truncate)
		et->et_ops->eo_extent_map_truncate(et, clusters);
}

static inline int ocfs2_et_root_journal_access(handle_t *handle,
					       struct ocfs2_extent_tree *et,
					       int type)
{
	return et->et_root_journal_access(handle, et->et_ci, et->et_root_bh,
					  type);
}

static inline enum ocfs2_contig_type
	ocfs2_et_extent_contig(struct ocfs2_extent_tree *et,
			       struct ocfs2_extent_rec *rec,
			       struct ocfs2_extent_rec *insert_rec)
{
	if (et->et_ops->eo_extent_contig)
		return et->et_ops->eo_extent_contig(et, rec, insert_rec);

	return ocfs2_extent_rec_contig(
				ocfs2_metadata_cache_get_super(et->et_ci),
				rec, insert_rec);
}

static inline int ocfs2_et_insert_check(struct ocfs2_extent_tree *et,
					struct ocfs2_extent_rec *rec)
{
	int ret = 0;

	if (et->et_ops->eo_insert_check)
		ret = et->et_ops->eo_insert_check(et, rec);
	return ret;
}

static inline int ocfs2_et_sanity_check(struct ocfs2_extent_tree *et)
{
	int ret = 0;

	if (et->et_ops->eo_sanity_check)
		ret = et->et_ops->eo_sanity_check(et);
	return ret;
}

static int ocfs2_cache_extent_block_free(struct ocfs2_cached_dealloc_ctxt *ctxt,
					 struct ocfs2_extent_block *eb);
static void ocfs2_adjust_rightmost_records(handle_t *handle,
					   struct ocfs2_extent_tree *et,
					   struct ocfs2_path *path,
					   struct ocfs2_extent_rec *insert_rec);
void ocfs2_reinit_path(struct ocfs2_path *path, int keep_root)
{
	int i, start = 0, depth = 0;
	struct ocfs2_path_item *node;

	if (keep_root)
		start = 1;

	for(i = start; i < path_num_items(path); i++) {
		node = &path->p_node[i];

		brelse(node->bh);
		node->bh = NULL;
		node->el = NULL;
	}

	if (keep_root)
		depth = le16_to_cpu(path_root_el(path)->l_tree_depth);
	else
		path_root_access(path) = NULL;

	path->p_tree_depth = depth;
}

void ocfs2_free_path(struct ocfs2_path *path)
{
	if (path) {
		ocfs2_reinit_path(path, 0);
		kfree(path);
	}
}

static void ocfs2_cp_path(struct ocfs2_path *dest, struct ocfs2_path *src)
{
	int i;

	BUG_ON(path_root_bh(dest) != path_root_bh(src));
	BUG_ON(path_root_el(dest) != path_root_el(src));
	BUG_ON(path_root_access(dest) != path_root_access(src));

	ocfs2_reinit_path(dest, 1);

	for(i = 1; i < OCFS2_MAX_PATH_DEPTH; i++) {
		dest->p_node[i].bh = src->p_node[i].bh;
		dest->p_node[i].el = src->p_node[i].el;

		if (dest->p_node[i].bh)
			get_bh(dest->p_node[i].bh);
	}
}

static void ocfs2_mv_path(struct ocfs2_path *dest, struct ocfs2_path *src)
{
	int i;

	BUG_ON(path_root_bh(dest) != path_root_bh(src));
	BUG_ON(path_root_access(dest) != path_root_access(src));

	for(i = 1; i < OCFS2_MAX_PATH_DEPTH; i++) {
		brelse(dest->p_node[i].bh);

		dest->p_node[i].bh = src->p_node[i].bh;
		dest->p_node[i].el = src->p_node[i].el;

		src->p_node[i].bh = NULL;
		src->p_node[i].el = NULL;
	}
}

static inline void ocfs2_path_insert_eb(struct ocfs2_path *path, int index,
					struct buffer_head *eb_bh)
{
	struct ocfs2_extent_block *eb = (struct ocfs2_extent_block *)eb_bh->b_data;

	BUG_ON(index == 0);

	path->p_node[index].bh = eb_bh;
	path->p_node[index].el = &eb->h_list;
}

static struct ocfs2_path *ocfs2_new_path(struct buffer_head *root_bh,
					 struct ocfs2_extent_list *root_el,
					 ocfs2_journal_access_func access)
{
	struct ocfs2_path *path;

	BUG_ON(le16_to_cpu(root_el->l_tree_depth) >= OCFS2_MAX_PATH_DEPTH);

	path = kzalloc(sizeof(*path), GFP_NOFS);
	if (path) {
		path->p_tree_depth = le16_to_cpu(root_el->l_tree_depth);
		get_bh(root_bh);
		path_root_bh(path) = root_bh;
		path_root_el(path) = root_el;
		path_root_access(path) = access;
	}

	return path;
}

struct ocfs2_path *ocfs2_new_path_from_path(struct ocfs2_path *path)
{
	return ocfs2_new_path(path_root_bh(path), path_root_el(path),
			      path_root_access(path));
}

struct ocfs2_path *ocfs2_new_path_from_et(struct ocfs2_extent_tree *et)
{
	return ocfs2_new_path(et->et_root_bh, et->et_root_el,
			      et->et_root_journal_access);
}

int ocfs2_path_bh_journal_access(handle_t *handle,
				 struct ocfs2_caching_info *ci,
				 struct ocfs2_path *path,
				 int idx)
{
	ocfs2_journal_access_func access = path_root_access(path);

	if (!access)
		access = ocfs2_journal_access;

	if (idx)
		access = ocfs2_journal_access_eb;

	return access(handle, ci, path->p_node[idx].bh,
		      OCFS2_JOURNAL_ACCESS_WRITE);
}

int ocfs2_journal_access_path(struct ocfs2_caching_info *ci,
			      handle_t *handle,
			      struct ocfs2_path *path)
{
	int i, ret = 0;

	if (!path)
		goto out;

	for(i = 0; i < path_num_items(path); i++) {
		ret = ocfs2_path_bh_journal_access(handle, ci, path, i);
		if (ret < 0) {
			mlog_errno(ret);
			goto out;
		}
	}

out:
	return ret;
}

int ocfs2_search_extent_list(struct ocfs2_extent_list *el, u32 v_cluster)
{
	int ret = -1;
	int i;
	struct ocfs2_extent_rec *rec;
	u32 rec_end, rec_start, clusters;

	for(i = 0; i < le16_to_cpu(el->l_next_free_rec); i++) {
		rec = &el->l_recs[i];

		rec_start = le32_to_cpu(rec->e_cpos);
		clusters = ocfs2_rec_clusters(el, rec);

		rec_end = rec_start + clusters;

		if (v_cluster >= rec_start && v_cluster < rec_end) {
			ret = i;
			break;
		}
	}

	return ret;
}

static int ocfs2_block_extent_contig(struct super_block *sb,
				     struct ocfs2_extent_rec *ext,
				     u64 blkno)
{
	u64 blk_end = le64_to_cpu(ext->e_blkno);

	blk_end += ocfs2_clusters_to_blocks(sb,
				    le16_to_cpu(ext->e_leaf_clusters));

	return blkno == blk_end;
}

static int ocfs2_extents_adjacent(struct ocfs2_extent_rec *left,
				  struct ocfs2_extent_rec *right)
{
	u32 left_range;

	left_range = le32_to_cpu(left->e_cpos) +
		le16_to_cpu(left->e_leaf_clusters);

	return (left_range == le32_to_cpu(right->e_cpos));
}

static enum ocfs2_contig_type
	ocfs2_extent_rec_contig(struct super_block *sb,
				struct ocfs2_extent_rec *ext,
				struct ocfs2_extent_rec *insert_rec)
{
	u64 blkno = le64_to_cpu(insert_rec->e_blkno);

	/*
	 * Refuse to coalesce extent records with different flag
	 * fields - we don't want to mix unwritten extents with user
	 * data.
	 */
	if (ext->e_flags != insert_rec->e_flags)
		return CONTIG_NONE;

	if (ocfs2_extents_adjacent(ext, insert_rec) &&
	    ocfs2_block_extent_contig(sb, ext, blkno))
			return CONTIG_RIGHT;

	blkno = le64_to_cpu(ext->e_blkno);
	if (ocfs2_extents_adjacent(insert_rec, ext) &&
	    ocfs2_block_extent_contig(sb, insert_rec, blkno))
		return CONTIG_LEFT;

	return CONTIG_NONE;
}

enum ocfs2_append_type {
	APPEND_NONE = 0,
	APPEND_TAIL,
};

enum ocfs2_split_type {
	SPLIT_NONE = 0,
	SPLIT_LEFT,
	SPLIT_RIGHT,
};

struct ocfs2_insert_type {
	enum ocfs2_split_type	ins_split;
	enum ocfs2_append_type	ins_appending;
	enum ocfs2_contig_type	ins_contig;
	int			ins_contig_index;
	int			ins_tree_depth;
};

struct ocfs2_merge_ctxt {
	enum ocfs2_contig_type	c_contig_type;
	int			c_has_empty_extent;
	int			c_split_covers_rec;
};

static int ocfs2_validate_extent_block(struct super_block *sb,
				       struct buffer_head *bh)
{
	int rc;
	struct ocfs2_extent_block *eb =
		(struct ocfs2_extent_block *)bh->b_data;

	trace_ocfs2_validate_extent_block((unsigned long long)bh->b_blocknr);

	BUG_ON(!buffer_uptodate(bh));

	rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &eb->h_check);
	if (rc) {
		mlog(ML_ERROR, "Checksum failed for extent block %llu\n",
		     (unsigned long long)bh->b_blocknr);
		return rc;
	}


	if (!OCFS2_IS_VALID_EXTENT_BLOCK(eb)) {
		ocfs2_error(sb,
			    "Extent block #%llu has bad signature %.*s",
			    (unsigned long long)bh->b_blocknr, 7,
			    eb->h_signature);
		return -EINVAL;
	}

	if (le64_to_cpu(eb->h_blkno) != bh->b_blocknr) {
		ocfs2_error(sb,
			    "Extent block #%llu has an invalid h_blkno "
			    "of %llu",
			    (unsigned long long)bh->b_blocknr,
			    (unsigned long long)le64_to_cpu(eb->h_blkno));
		return -EINVAL;
	}

	if (le32_to_cpu(eb->h_fs_generation) != OCFS2_SB(sb)->fs_generation) {
		ocfs2_error(sb,
			    "Extent block #%llu has an invalid "
			    "h_fs_generation of #%u",
			    (unsigned long long)bh->b_blocknr,
			    le32_to_cpu(eb->h_fs_generation));
		return -EINVAL;
	}

	return 0;
}

int ocfs2_read_extent_block(struct ocfs2_caching_info *ci, u64 eb_blkno,
			    struct buffer_head **bh)
{
	int rc;
	struct buffer_head *tmp = *bh;

	rc = ocfs2_read_block(ci, eb_blkno, &tmp,
			      ocfs2_validate_extent_block);

	
	if (!rc && !*bh)
		*bh = tmp;

	return rc;
}


int ocfs2_num_free_extents(struct ocfs2_super *osb,
			   struct ocfs2_extent_tree *et)
{
	int retval;
	struct ocfs2_extent_list *el = NULL;
	struct ocfs2_extent_block *eb;
	struct buffer_head *eb_bh = NULL;
	u64 last_eb_blk = 0;

	el = et->et_root_el;
	last_eb_blk = ocfs2_et_get_last_eb_blk(et);

	if (last_eb_blk) {
		retval = ocfs2_read_extent_block(et->et_ci, last_eb_blk,
						 &eb_bh);
		if (retval < 0) {
			mlog_errno(retval);
			goto bail;
		}
		eb = (struct ocfs2_extent_block *) eb_bh->b_data;
		el = &eb->h_list;
	}

	BUG_ON(el->l_tree_depth != 0);

	retval = le16_to_cpu(el->l_count) - le16_to_cpu(el->l_next_free_rec);
bail:
	brelse(eb_bh);

	trace_ocfs2_num_free_extents(retval);
	return retval;
}

static int ocfs2_create_new_meta_bhs(handle_t *handle,
				     struct ocfs2_extent_tree *et,
				     int wanted,
				     struct ocfs2_alloc_context *meta_ac,
				     struct buffer_head *bhs[])
{
	int count, status, i;
	u16 suballoc_bit_start;
	u32 num_got;
	u64 suballoc_loc, first_blkno;
	struct ocfs2_super *osb =
		OCFS2_SB(ocfs2_metadata_cache_get_super(et->et_ci));
	struct ocfs2_extent_block *eb;

	count = 0;
	while (count < wanted) {
		status = ocfs2_claim_metadata(handle,
					      meta_ac,
					      wanted - count,
					      &suballoc_loc,
					      &suballoc_bit_start,
					      &num_got,
					      &first_blkno);
		if (status < 0) {
			mlog_errno(status);
			goto bail;
		}

		for(i = count;  i < (num_got + count); i++) {
			bhs[i] = sb_getblk(osb->sb, first_blkno);
			if (bhs[i] == NULL) {
				status = -EIO;
				mlog_errno(status);
				goto bail;
			}
			ocfs2_set_new_buffer_uptodate(et->et_ci, bhs[i]);

			status = ocfs2_journal_access_eb(handle, et->et_ci,
							 bhs[i],
							 OCFS2_JOURNAL_ACCESS_CREATE);
			if (status < 0) {
				mlog_errno(status);
				goto bail;
			}

			memset(bhs[i]->b_data, 0, osb->sb->s_blocksize);
			eb = (struct ocfs2_extent_block *) bhs[i]->b_data;
			
			strcpy(eb->h_signature, OCFS2_EXTENT_BLOCK_SIGNATURE);
			eb->h_blkno = cpu_to_le64(first_blkno);
			eb->h_fs_generation = cpu_to_le32(osb->fs_generation);
			eb->h_suballoc_slot =
				cpu_to_le16(meta_ac->ac_alloc_slot);
			eb->h_suballoc_loc = cpu_to_le64(suballoc_loc);
			eb->h_suballoc_bit = cpu_to_le16(suballoc_bit_start);
			eb->h_list.l_count =
				cpu_to_le16(ocfs2_extent_recs_per_eb(osb->sb));

			suballoc_bit_start++;
			first_blkno++;

			ocfs2_journal_dirty(handle, bhs[i]);
		}

		count += num_got;
	}

	status = 0;
bail:
	if (status < 0) {
		for(i = 0; i < wanted; i++) {
			brelse(bhs[i]);
			bhs[i] = NULL;
		}
		mlog_errno(status);
	}
	return status;
}

static inline u32 ocfs2_sum_rightmost_rec(struct ocfs2_extent_list  *el)
{
	int i;

	i = le16_to_cpu(el->l_next_free_rec) - 1;

	return le32_to_cpu(el->l_recs[i].e_cpos) +
		ocfs2_rec_clusters(el, &el->l_recs[i]);
}

static int ocfs2_adjust_rightmost_branch(handle_t *handle,
					 struct ocfs2_extent_tree *et)
{
	int status;
	struct ocfs2_path *path = NULL;
	struct ocfs2_extent_list *el;
	struct ocfs2_extent_rec *rec;

	path = ocfs2_new_path_from_et(et);
	if (!path) {
		status = -ENOMEM;
		return status;
	}

	status = ocfs2_find_path(et->et_ci, path, UINT_MAX);
	if (status < 0) {
		mlog_errno(status);
		goto out;
	}

	status = ocfs2_extend_trans(handle, path_num_items(path));
	if (status < 0) {
		mlog_errno(status);
		goto out;
	}

	status = ocfs2_journal_access_path(et->et_ci, handle, path);
	if (status < 0) {
		mlog_errno(status);
		goto out;
	}

	el = path_leaf_el(path);
	rec = &el->l_recs[le16_to_cpu(el->l_next_free_rec) - 1];

	ocfs2_adjust_rightmost_records(handle, et, path, rec);

out:
	ocfs2_free_path(path);
	return status;
}

static int ocfs2_add_branch(handle_t *handle,
			    struct ocfs2_extent_tree *et,
			    struct buffer_head *eb_bh,
			    struct buffer_head **last_eb_bh,
			    struct ocfs2_alloc_context *meta_ac)
{
	int status, new_blocks, i;
	u64 next_blkno, new_last_eb_blk;
	struct buffer_head *bh;
	struct buffer_head **new_eb_bhs = NULL;
	struct ocfs2_extent_block *eb;
	struct ocfs2_extent_list  *eb_el;
	struct ocfs2_extent_list  *el;
	u32 new_cpos, root_end;

	BUG_ON(!last_eb_bh || !*last_eb_bh);

	if (eb_bh) {
		eb = (struct ocfs2_extent_block *) eb_bh->b_data;
		el = &eb->h_list;
	} else
		el = et->et_root_el;

	
	BUG_ON(!el->l_tree_depth);

	new_blocks = le16_to_cpu(el->l_tree_depth);

	eb = (struct ocfs2_extent_block *)(*last_eb_bh)->b_data;
	new_cpos = ocfs2_sum_rightmost_rec(&eb->h_list);
	root_end = ocfs2_sum_rightmost_rec(et->et_root_el);

	if (root_end > new_cpos) {
		trace_ocfs2_adjust_rightmost_branch(
			(unsigned long long)
			ocfs2_metadata_cache_owner(et->et_ci),
			root_end, new_cpos);

		status = ocfs2_adjust_rightmost_branch(handle, et);
		if (status) {
			mlog_errno(status);
			goto bail;
		}
	}

	
	new_eb_bhs = kcalloc(new_blocks, sizeof(struct buffer_head *),
			     GFP_KERNEL);
	if (!new_eb_bhs) {
		status = -ENOMEM;
		mlog_errno(status);
		goto bail;
	}

	status = ocfs2_create_new_meta_bhs(handle, et, new_blocks,
					   meta_ac, new_eb_bhs);
	if (status < 0) {
		mlog_errno(status);
		goto bail;
	}

	next_blkno = new_last_eb_blk = 0;
	for(i = 0; i < new_blocks; i++) {
		bh = new_eb_bhs[i];
		eb = (struct ocfs2_extent_block *) bh->b_data;
		
		BUG_ON(!OCFS2_IS_VALID_EXTENT_BLOCK(eb));
		eb_el = &eb->h_list;

		status = ocfs2_journal_access_eb(handle, et->et_ci, bh,
						 OCFS2_JOURNAL_ACCESS_CREATE);
		if (status < 0) {
			mlog_errno(status);
			goto bail;
		}

		eb->h_next_leaf_blk = 0;
		eb_el->l_tree_depth = cpu_to_le16(i);
		eb_el->l_next_free_rec = cpu_to_le16(1);
		eb_el->l_recs[0].e_cpos = cpu_to_le32(new_cpos);
		eb_el->l_recs[0].e_blkno = cpu_to_le64(next_blkno);
		eb_el->l_recs[0].e_int_clusters = cpu_to_le32(0);
		if (!eb_el->l_tree_depth)
			new_last_eb_blk = le64_to_cpu(eb->h_blkno);

		ocfs2_journal_dirty(handle, bh);
		next_blkno = le64_to_cpu(eb->h_blkno);
	}

	status = ocfs2_journal_access_eb(handle, et->et_ci, *last_eb_bh,
					 OCFS2_JOURNAL_ACCESS_WRITE);
	if (status < 0) {
		mlog_errno(status);
		goto bail;
	}
	status = ocfs2_et_root_journal_access(handle, et,
					      OCFS2_JOURNAL_ACCESS_WRITE);
	if (status < 0) {
		mlog_errno(status);
		goto bail;
	}
	if (eb_bh) {
		status = ocfs2_journal_access_eb(handle, et->et_ci, eb_bh,
						 OCFS2_JOURNAL_ACCESS_WRITE);
		if (status < 0) {
			mlog_errno(status);
			goto bail;
		}
	}

	i = le16_to_cpu(el->l_next_free_rec);
	el->l_recs[i].e_blkno = cpu_to_le64(next_blkno);
	el->l_recs[i].e_cpos = cpu_to_le32(new_cpos);
	el->l_recs[i].e_int_clusters = 0;
	le16_add_cpu(&el->l_next_free_rec, 1);

	ocfs2_et_set_last_eb_blk(et, new_last_eb_blk);

	eb = (struct ocfs2_extent_block *) (*last_eb_bh)->b_data;
	eb->h_next_leaf_blk = cpu_to_le64(new_last_eb_blk);

	ocfs2_journal_dirty(handle, *last_eb_bh);
	ocfs2_journal_dirty(handle, et->et_root_bh);
	if (eb_bh)
		ocfs2_journal_dirty(handle, eb_bh);

	brelse(*last_eb_bh);
	get_bh(new_eb_bhs[0]);
	*last_eb_bh = new_eb_bhs[0];

	status = 0;
bail:
	if (new_eb_bhs) {
		for (i = 0; i < new_blocks; i++)
			brelse(new_eb_bhs[i]);
		kfree(new_eb_bhs);
	}

	return status;
}

static int ocfs2_shift_tree_depth(handle_t *handle,
				  struct ocfs2_extent_tree *et,
				  struct ocfs2_alloc_context *meta_ac,
				  struct buffer_head **ret_new_eb_bh)
{
	int status, i;
	u32 new_clusters;
	struct buffer_head *new_eb_bh = NULL;
	struct ocfs2_extent_block *eb;
	struct ocfs2_extent_list  *root_el;
	struct ocfs2_extent_list  *eb_el;

	status = ocfs2_create_new_meta_bhs(handle, et, 1, meta_ac,
					   &new_eb_bh);
	if (status < 0) {
		mlog_errno(status);
		goto bail;
	}

	eb = (struct ocfs2_extent_block *) new_eb_bh->b_data;
	
	BUG_ON(!OCFS2_IS_VALID_EXTENT_BLOCK(eb));

	eb_el = &eb->h_list;
	root_el = et->et_root_el;

	status = ocfs2_journal_access_eb(handle, et->et_ci, new_eb_bh,
					 OCFS2_JOURNAL_ACCESS_CREATE);
	if (status < 0) {
		mlog_errno(status);
		goto bail;
	}

	
	eb_el->l_tree_depth = root_el->l_tree_depth;
	eb_el->l_next_free_rec = root_el->l_next_free_rec;
	for (i = 0; i < le16_to_cpu(root_el->l_next_free_rec); i++)
		eb_el->l_recs[i] = root_el->l_recs[i];

	ocfs2_journal_dirty(handle, new_eb_bh);

	status = ocfs2_et_root_journal_access(handle, et,
					      OCFS2_JOURNAL_ACCESS_WRITE);
	if (status < 0) {
		mlog_errno(status);
		goto bail;
	}

	new_clusters = ocfs2_sum_rightmost_rec(eb_el);

	
	le16_add_cpu(&root_el->l_tree_depth, 1);
	root_el->l_recs[0].e_cpos = 0;
	root_el->l_recs[0].e_blkno = eb->h_blkno;
	root_el->l_recs[0].e_int_clusters = cpu_to_le32(new_clusters);
	for (i = 1; i < le16_to_cpu(root_el->l_next_free_rec); i++)
		memset(&root_el->l_recs[i], 0, sizeof(struct ocfs2_extent_rec));
	root_el->l_next_free_rec = cpu_to_le16(1);

	if (root_el->l_tree_depth == cpu_to_le16(1))
		ocfs2_et_set_last_eb_blk(et, le64_to_cpu(eb->h_blkno));

	ocfs2_journal_dirty(handle, et->et_root_bh);

	*ret_new_eb_bh = new_eb_bh;
	new_eb_bh = NULL;
	status = 0;
bail:
	brelse(new_eb_bh);

	return status;
}

static int ocfs2_find_branch_target(struct ocfs2_extent_tree *et,
				    struct buffer_head **target_bh)
{
	int status = 0, i;
	u64 blkno;
	struct ocfs2_extent_block *eb;
	struct ocfs2_extent_list  *el;
	struct buffer_head *bh = NULL;
	struct buffer_head *lowest_bh = NULL;

	*target_bh = NULL;

	el = et->et_root_el;

	while(le16_to_cpu(el->l_tree_depth) > 1) {
		if (le16_to_cpu(el->l_next_free_rec) == 0) {
			ocfs2_error(ocfs2_metadata_cache_get_super(et->et_ci),
				    "Owner %llu has empty "
				    "extent list (next_free_rec == 0)",
				    (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci));
			status = -EIO;
			goto bail;
		}
		i = le16_to_cpu(el->l_next_free_rec) - 1;
		blkno = le64_to_cpu(el->l_recs[i].e_blkno);
		if (!blkno) {
			ocfs2_error(ocfs2_metadata_cache_get_super(et->et_ci),
				    "Owner %llu has extent "
				    "list where extent # %d has no physical "
				    "block start",
				    (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci), i);
			status = -EIO;
			goto bail;
		}

		brelse(bh);
		bh = NULL;

		status = ocfs2_read_extent_block(et->et_ci, blkno, &bh);
		if (status < 0) {
			mlog_errno(status);
			goto bail;
		}

		eb = (struct ocfs2_extent_block *) bh->b_data;
		el = &eb->h_list;

		if (le16_to_cpu(el->l_next_free_rec) <
		    le16_to_cpu(el->l_count)) {
			brelse(lowest_bh);
			lowest_bh = bh;
			get_bh(lowest_bh);
		}
	}

	el = et->et_root_el;
	if (!lowest_bh && (el->l_next_free_rec == el->l_count))
		status = 1;

	*target_bh = lowest_bh;
bail:
	brelse(bh);

	return status;
}

static int ocfs2_grow_tree(handle_t *handle, struct ocfs2_extent_tree *et,
			   int *final_depth, struct buffer_head **last_eb_bh,
			   struct ocfs2_alloc_context *meta_ac)
{
	int ret, shift;
	struct ocfs2_extent_list *el = et->et_root_el;
	int depth = le16_to_cpu(el->l_tree_depth);
	struct buffer_head *bh = NULL;

	BUG_ON(meta_ac == NULL);

	shift = ocfs2_find_branch_target(et, &bh);
	if (shift < 0) {
		ret = shift;
		mlog_errno(ret);
		goto out;
	}

	if (shift) {
		BUG_ON(bh);
		trace_ocfs2_grow_tree(
			(unsigned long long)
			ocfs2_metadata_cache_owner(et->et_ci),
			depth);

		ret = ocfs2_shift_tree_depth(handle, et, meta_ac, &bh);
		if (ret < 0) {
			mlog_errno(ret);
			goto out;
		}
		depth++;
		if (depth == 1) {
			BUG_ON(*last_eb_bh);
			get_bh(bh);
			*last_eb_bh = bh;
			goto out;
		}
	}

	ret = ocfs2_add_branch(handle, et, bh, last_eb_bh,
			       meta_ac);
	if (ret < 0) {
		mlog_errno(ret);
		goto out;
	}

out:
	if (final_depth)
		*final_depth = depth;
	brelse(bh);
	return ret;
}

static void ocfs2_shift_records_right(struct ocfs2_extent_list *el)
{
	int next_free = le16_to_cpu(el->l_next_free_rec);
	int count = le16_to_cpu(el->l_count);
	unsigned int num_bytes;

	BUG_ON(!next_free);
	
	BUG_ON(next_free >= count);

	num_bytes = sizeof(struct ocfs2_extent_rec) * next_free;

	memmove(&el->l_recs[1], &el->l_recs[0], num_bytes);
}

static void ocfs2_rotate_leaf(struct ocfs2_extent_list *el,
			      struct ocfs2_extent_rec *insert_rec)
{
	int i, insert_index, next_free, has_empty, num_bytes;
	u32 insert_cpos = le32_to_cpu(insert_rec->e_cpos);
	struct ocfs2_extent_rec *rec;

	next_free = le16_to_cpu(el->l_next_free_rec);
	has_empty = ocfs2_is_empty_extent(&el->l_recs[0]);

	BUG_ON(!next_free);

	
	BUG_ON(el->l_next_free_rec == el->l_count && !has_empty);

	if (has_empty) {
		for(i = 0; i < (next_free - 1); i++)
			el->l_recs[i] = el->l_recs[i+1];

		next_free--;
	}

	for(i = 0; i < next_free; i++) {
		rec = &el->l_recs[i];

		if (insert_cpos < le32_to_cpu(rec->e_cpos))
			break;
	}
	insert_index = i;

	trace_ocfs2_rotate_leaf(insert_cpos, insert_index,
				has_empty, next_free,
				le16_to_cpu(el->l_count));

	BUG_ON(insert_index < 0);
	BUG_ON(insert_index >= le16_to_cpu(el->l_count));
	BUG_ON(insert_index > next_free);

	if (insert_index != next_free) {
		BUG_ON(next_free >= le16_to_cpu(el->l_count));

		num_bytes = next_free - insert_index;
		num_bytes *= sizeof(struct ocfs2_extent_rec);
		memmove(&el->l_recs[insert_index + 1],
			&el->l_recs[insert_index],
			num_bytes);
	}

	next_free++;
	el->l_next_free_rec = cpu_to_le16(next_free);
	BUG_ON(le16_to_cpu(el->l_next_free_rec) > le16_to_cpu(el->l_count));

	el->l_recs[insert_index] = *insert_rec;

}

static void ocfs2_remove_empty_extent(struct ocfs2_extent_list *el)
{
	int size, num_recs = le16_to_cpu(el->l_next_free_rec);

	BUG_ON(num_recs == 0);

	if (ocfs2_is_empty_extent(&el->l_recs[0])) {
		num_recs--;
		size = num_recs * sizeof(struct ocfs2_extent_rec);
		memmove(&el->l_recs[0], &el->l_recs[1], size);
		memset(&el->l_recs[num_recs], 0,
		       sizeof(struct ocfs2_extent_rec));
		el->l_next_free_rec = cpu_to_le16(num_recs);
	}
}

static void ocfs2_create_empty_extent(struct ocfs2_extent_list *el)
{
	int next_free = le16_to_cpu(el->l_next_free_rec);

	BUG_ON(le16_to_cpu(el->l_tree_depth) != 0);

	if (next_free == 0)
		goto set_and_inc;

	if (ocfs2_is_empty_extent(&el->l_recs[0]))
		return;

	mlog_bug_on_msg(el->l_count == el->l_next_free_rec,
			"Asked to create an empty extent in a full list:\n"
			"count = %u, tree depth = %u",
			le16_to_cpu(el->l_count),
			le16_to_cpu(el->l_tree_depth));

	ocfs2_shift_records_right(el);

set_and_inc:
	le16_add_cpu(&el->l_next_free_rec, 1);
	memset(&el->l_recs[0], 0, sizeof(struct ocfs2_extent_rec));
}

int ocfs2_find_subtree_root(struct ocfs2_extent_tree *et,
			    struct ocfs2_path *left,
			    struct ocfs2_path *right)
{
	int i = 0;

	BUG_ON(path_root_bh(left) != path_root_bh(right));

	do {
		i++;

		mlog_bug_on_msg(i > left->p_tree_depth,
				"Owner %llu, left depth %u, right depth %u\n"
				"left leaf blk %llu, right leaf blk %llu\n",
				(unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),
				left->p_tree_depth, right->p_tree_depth,
				(unsigned long long)path_leaf_bh(left)->b_blocknr,
				(unsigned long long)path_leaf_bh(right)->b_blocknr);
	} while (left->p_node[i].bh->b_blocknr ==
		 right->p_node[i].bh->b_blocknr);

	return i - 1;
}

typedef void (path_insert_t)(void *, struct buffer_head *);

static int __ocfs2_find_path(struct ocfs2_caching_info *ci,
			     struct ocfs2_extent_list *root_el, u32 cpos,
			     path_insert_t *func, void *data)
{
	int i, ret = 0;
	u32 range;
	u64 blkno;
	struct buffer_head *bh = NULL;
	struct ocfs2_extent_block *eb;
	struct ocfs2_extent_list *el;
	struct ocfs2_extent_rec *rec;

	el = root_el;
	while (el->l_tree_depth) {
		if (le16_to_cpu(el->l_next_free_rec) == 0) {
			ocfs2_error(ocfs2_metadata_cache_get_super(ci),
				    "Owner %llu has empty extent list at "
				    "depth %u\n",
				    (unsigned long long)ocfs2_metadata_cache_owner(ci),
				    le16_to_cpu(el->l_tree_depth));
			ret = -EROFS;
			goto out;

		}

		for(i = 0; i < le16_to_cpu(el->l_next_free_rec) - 1; i++) {
			rec = &el->l_recs[i];

			range = le32_to_cpu(rec->e_cpos) +
				ocfs2_rec_clusters(el, rec);
			if (cpos >= le32_to_cpu(rec->e_cpos) && cpos < range)
			    break;
		}

		blkno = le64_to_cpu(el->l_recs[i].e_blkno);
		if (blkno == 0) {
			ocfs2_error(ocfs2_metadata_cache_get_super(ci),
				    "Owner %llu has bad blkno in extent list "
				    "at depth %u (index %d)\n",
				    (unsigned long long)ocfs2_metadata_cache_owner(ci),
				    le16_to_cpu(el->l_tree_depth), i);
			ret = -EROFS;
			goto out;
		}

		brelse(bh);
		bh = NULL;
		ret = ocfs2_read_extent_block(ci, blkno, &bh);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		eb = (struct ocfs2_extent_block *) bh->b_data;
		el = &eb->h_list;

		if (le16_to_cpu(el->l_next_free_rec) >
		    le16_to_cpu(el->l_count)) {
			ocfs2_error(ocfs2_metadata_cache_get_super(ci),
				    "Owner %llu has bad count in extent list "
				    "at block %llu (next free=%u, count=%u)\n",
				    (unsigned long long)ocfs2_metadata_cache_owner(ci),
				    (unsigned long long)bh->b_blocknr,
				    le16_to_cpu(el->l_next_free_rec),
				    le16_to_cpu(el->l_count));
			ret = -EROFS;
			goto out;
		}

		if (func)
			func(data, bh);
	}

out:
	brelse(bh);

	return ret;
}

struct find_path_data {
	int index;
	struct ocfs2_path *path;
};
static void find_path_ins(void *data, struct buffer_head *bh)
{
	struct find_path_data *fp = data;

	get_bh(bh);
	ocfs2_path_insert_eb(fp->path, fp->index, bh);
	fp->index++;
}
int ocfs2_find_path(struct ocfs2_caching_info *ci,
		    struct ocfs2_path *path, u32 cpos)
{
	struct find_path_data data;

	data.index = 1;
	data.path = path;
	return __ocfs2_find_path(ci, path_root_el(path), cpos,
				 find_path_ins, &data);
}

static void find_leaf_ins(void *data, struct buffer_head *bh)
{
	struct ocfs2_extent_block *eb =(struct ocfs2_extent_block *)bh->b_data;
	struct ocfs2_extent_list *el = &eb->h_list;
	struct buffer_head **ret = data;

	
	if (le16_to_cpu(el->l_tree_depth) == 0) {
		get_bh(bh);
		*ret = bh;
	}
}
int ocfs2_find_leaf(struct ocfs2_caching_info *ci,
		    struct ocfs2_extent_list *root_el, u32 cpos,
		    struct buffer_head **leaf_bh)
{
	int ret;
	struct buffer_head *bh = NULL;

	ret = __ocfs2_find_path(ci, root_el, cpos, find_leaf_ins, &bh);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	*leaf_bh = bh;
out:
	return ret;
}

static void ocfs2_adjust_adjacent_records(struct ocfs2_extent_rec *left_rec,
				  struct ocfs2_extent_list *left_child_el,
				  struct ocfs2_extent_rec *right_rec,
				  struct ocfs2_extent_list *right_child_el)
{
	u32 left_clusters, right_end;

	left_clusters = le32_to_cpu(right_child_el->l_recs[0].e_cpos);
	if (!ocfs2_rec_clusters(right_child_el, &right_child_el->l_recs[0])) {
		BUG_ON(right_child_el->l_tree_depth);
		BUG_ON(le16_to_cpu(right_child_el->l_next_free_rec) <= 1);
		left_clusters = le32_to_cpu(right_child_el->l_recs[1].e_cpos);
	}
	left_clusters -= le32_to_cpu(left_rec->e_cpos);
	left_rec->e_int_clusters = cpu_to_le32(left_clusters);

	right_end = le32_to_cpu(right_rec->e_cpos);
	right_end += le32_to_cpu(right_rec->e_int_clusters);

	right_rec->e_cpos = left_rec->e_cpos;
	le32_add_cpu(&right_rec->e_cpos, left_clusters);

	right_end -= le32_to_cpu(right_rec->e_cpos);
	right_rec->e_int_clusters = cpu_to_le32(right_end);
}

static void ocfs2_adjust_root_records(struct ocfs2_extent_list *root_el,
				      struct ocfs2_extent_list *left_el,
				      struct ocfs2_extent_list *right_el,
				      u64 left_el_blkno)
{
	int i;

	BUG_ON(le16_to_cpu(root_el->l_tree_depth) <=
	       le16_to_cpu(left_el->l_tree_depth));

	for(i = 0; i < le16_to_cpu(root_el->l_next_free_rec) - 1; i++) {
		if (le64_to_cpu(root_el->l_recs[i].e_blkno) == left_el_blkno)
			break;
	}

	BUG_ON(i >= (le16_to_cpu(root_el->l_next_free_rec) - 1));

	ocfs2_adjust_adjacent_records(&root_el->l_recs[i], left_el,
				      &root_el->l_recs[i + 1], right_el);
}

static void ocfs2_complete_edge_insert(handle_t *handle,
				       struct ocfs2_path *left_path,
				       struct ocfs2_path *right_path,
				       int subtree_index)
{
	int i, idx;
	struct ocfs2_extent_list *el, *left_el, *right_el;
	struct ocfs2_extent_rec *left_rec, *right_rec;
	struct buffer_head *root_bh = left_path->p_node[subtree_index].bh;

	left_el = path_leaf_el(left_path);
	right_el = path_leaf_el(right_path);
	for(i = left_path->p_tree_depth - 1; i > subtree_index; i--) {
		trace_ocfs2_complete_edge_insert(i);

		el = left_path->p_node[i].el;
		idx = le16_to_cpu(left_el->l_next_free_rec) - 1;
		left_rec = &el->l_recs[idx];

		el = right_path->p_node[i].el;
		right_rec = &el->l_recs[0];

		ocfs2_adjust_adjacent_records(left_rec, left_el, right_rec,
					      right_el);

		ocfs2_journal_dirty(handle, left_path->p_node[i].bh);
		ocfs2_journal_dirty(handle, right_path->p_node[i].bh);

		left_el = left_path->p_node[i].el;
		right_el = right_path->p_node[i].el;
	}


	el = left_path->p_node[subtree_index].el;
	left_el = left_path->p_node[subtree_index + 1].el;
	right_el = right_path->p_node[subtree_index + 1].el;

	ocfs2_adjust_root_records(el, left_el, right_el,
				  left_path->p_node[subtree_index + 1].bh->b_blocknr);

	root_bh = left_path->p_node[subtree_index].bh;

	ocfs2_journal_dirty(handle, root_bh);
}

static int ocfs2_rotate_subtree_right(handle_t *handle,
				      struct ocfs2_extent_tree *et,
				      struct ocfs2_path *left_path,
				      struct ocfs2_path *right_path,
				      int subtree_index)
{
	int ret, i;
	struct buffer_head *right_leaf_bh;
	struct buffer_head *left_leaf_bh = NULL;
	struct buffer_head *root_bh;
	struct ocfs2_extent_list *right_el, *left_el;
	struct ocfs2_extent_rec move_rec;

	left_leaf_bh = path_leaf_bh(left_path);
	left_el = path_leaf_el(left_path);

	if (left_el->l_next_free_rec != left_el->l_count) {
		ocfs2_error(ocfs2_metadata_cache_get_super(et->et_ci),
			    "Inode %llu has non-full interior leaf node %llu"
			    "(next free = %u)",
			    (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),
			    (unsigned long long)left_leaf_bh->b_blocknr,
			    le16_to_cpu(left_el->l_next_free_rec));
		return -EROFS;
	}

	if (ocfs2_is_empty_extent(&left_el->l_recs[0]))
		return 0;

	root_bh = left_path->p_node[subtree_index].bh;
	BUG_ON(root_bh != right_path->p_node[subtree_index].bh);

	ret = ocfs2_path_bh_journal_access(handle, et->et_ci, right_path,
					   subtree_index);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	for(i = subtree_index + 1; i < path_num_items(right_path); i++) {
		ret = ocfs2_path_bh_journal_access(handle, et->et_ci,
						   right_path, i);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		ret = ocfs2_path_bh_journal_access(handle, et->et_ci,
						   left_path, i);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}
	}

	right_leaf_bh = path_leaf_bh(right_path);
	right_el = path_leaf_el(right_path);

	
	mlog_bug_on_msg(!right_el->l_next_free_rec, "Inode %llu: Rotate fails "
			"because rightmost leaf block %llu is empty\n",
			(unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),
			(unsigned long long)right_leaf_bh->b_blocknr);

	ocfs2_create_empty_extent(right_el);

	ocfs2_journal_dirty(handle, right_leaf_bh);

	
	i = le16_to_cpu(left_el->l_next_free_rec) - 1;
	move_rec = left_el->l_recs[i];
	right_el->l_recs[0] = move_rec;

	le16_add_cpu(&left_el->l_next_free_rec, -1);
	ocfs2_shift_records_right(left_el);
	memset(&left_el->l_recs[0], 0, sizeof(struct ocfs2_extent_rec));
	le16_add_cpu(&left_el->l_next_free_rec, 1);

	ocfs2_journal_dirty(handle, left_leaf_bh);

	ocfs2_complete_edge_insert(handle, left_path, right_path,
				   subtree_index);

out:
	return ret;
}

int ocfs2_find_cpos_for_left_leaf(struct super_block *sb,
				  struct ocfs2_path *path, u32 *cpos)
{
	int i, j, ret = 0;
	u64 blkno;
	struct ocfs2_extent_list *el;

	BUG_ON(path->p_tree_depth == 0);

	*cpos = 0;

	blkno = path_leaf_bh(path)->b_blocknr;

	
	i = path->p_tree_depth - 1;
	while (i >= 0) {
		el = path->p_node[i].el;

		for(j = 0; j < le16_to_cpu(el->l_next_free_rec); j++) {
			if (le64_to_cpu(el->l_recs[j].e_blkno) == blkno) {
				if (j == 0) {
					if (i == 0) {
						goto out;
					}
					goto next_node;
				}

				*cpos = le32_to_cpu(el->l_recs[j - 1].e_cpos);
				*cpos = *cpos + ocfs2_rec_clusters(el,
							   &el->l_recs[j - 1]);
				*cpos = *cpos - 1;
				goto out;
			}
		}

		ocfs2_error(sb,
			    "Invalid extent tree at extent block %llu\n",
			    (unsigned long long)blkno);
		ret = -EROFS;
		goto out;

next_node:
		blkno = path->p_node[i].bh->b_blocknr;
		i--;
	}

out:
	return ret;
}

static int ocfs2_extend_rotate_transaction(handle_t *handle, int subtree_depth,
					   int op_credits,
					   struct ocfs2_path *path)
{
	int ret = 0;
	int credits = (path->p_tree_depth - subtree_depth) * 2 + 1 + op_credits;

	if (handle->h_buffer_credits < credits)
		ret = ocfs2_extend_trans(handle,
					 credits - handle->h_buffer_credits);

	return ret;
}

static int ocfs2_rotate_requires_path_adjustment(struct ocfs2_path *left_path,
						 u32 insert_cpos)
{
	struct ocfs2_extent_list *left_el;
	struct ocfs2_extent_rec *rec;
	int next_free;

	left_el = path_leaf_el(left_path);
	next_free = le16_to_cpu(left_el->l_next_free_rec);
	rec = &left_el->l_recs[next_free - 1];

	if (insert_cpos > le32_to_cpu(rec->e_cpos))
		return 1;
	return 0;
}

static int ocfs2_leftmost_rec_contains(struct ocfs2_extent_list *el, u32 cpos)
{
	int next_free = le16_to_cpu(el->l_next_free_rec);
	unsigned int range;
	struct ocfs2_extent_rec *rec;

	if (next_free == 0)
		return 0;

	rec = &el->l_recs[0];
	if (ocfs2_is_empty_extent(rec)) {
		
		if (next_free == 1)
			return 0;
		rec = &el->l_recs[1];
	}

	range = le32_to_cpu(rec->e_cpos) + ocfs2_rec_clusters(el, rec);
	if (cpos >= le32_to_cpu(rec->e_cpos) && cpos < range)
		return 1;
	return 0;
}

static int ocfs2_rotate_tree_right(handle_t *handle,
				   struct ocfs2_extent_tree *et,
				   enum ocfs2_split_type split,
				   u32 insert_cpos,
				   struct ocfs2_path *right_path,
				   struct ocfs2_path **ret_left_path)
{
	int ret, start, orig_credits = handle->h_buffer_credits;
	u32 cpos;
	struct ocfs2_path *left_path = NULL;
	struct super_block *sb = ocfs2_metadata_cache_get_super(et->et_ci);

	*ret_left_path = NULL;

	left_path = ocfs2_new_path_from_path(right_path);
	if (!left_path) {
		ret = -ENOMEM;
		mlog_errno(ret);
		goto out;
	}

	ret = ocfs2_find_cpos_for_left_leaf(sb, right_path, &cpos);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	trace_ocfs2_rotate_tree_right(
		(unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),
		insert_cpos, cpos);

	while (cpos && insert_cpos <= cpos) {
		trace_ocfs2_rotate_tree_right(
			(unsigned long long)
			ocfs2_metadata_cache_owner(et->et_ci),
			insert_cpos, cpos);

		ret = ocfs2_find_path(et->et_ci, left_path, cpos);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		mlog_bug_on_msg(path_leaf_bh(left_path) ==
				path_leaf_bh(right_path),
				"Owner %llu: error during insert of %u "
				"(left path cpos %u) results in two identical "
				"paths ending at %llu\n",
				(unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),
				insert_cpos, cpos,
				(unsigned long long)
				path_leaf_bh(left_path)->b_blocknr);

		if (split == SPLIT_NONE &&
		    ocfs2_rotate_requires_path_adjustment(left_path,
							  insert_cpos)) {

			*ret_left_path = left_path;
			goto out_ret_path;
		}

		start = ocfs2_find_subtree_root(et, left_path, right_path);

		trace_ocfs2_rotate_subtree(start,
			(unsigned long long)
			right_path->p_node[start].bh->b_blocknr,
			right_path->p_tree_depth);

		ret = ocfs2_extend_rotate_transaction(handle, start,
						      orig_credits, right_path);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		ret = ocfs2_rotate_subtree_right(handle, et, left_path,
						 right_path, start);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		if (split != SPLIT_NONE &&
		    ocfs2_leftmost_rec_contains(path_leaf_el(right_path),
						insert_cpos)) {
			*ret_left_path = left_path;
			goto out_ret_path;
		}

		ocfs2_mv_path(right_path, left_path);

		ret = ocfs2_find_cpos_for_left_leaf(sb, right_path, &cpos);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}
	}

out:
	ocfs2_free_path(left_path);

out_ret_path:
	return ret;
}

static int ocfs2_update_edge_lengths(handle_t *handle,
				     struct ocfs2_extent_tree *et,
				     int subtree_index, struct ocfs2_path *path)
{
	int i, idx, ret;
	struct ocfs2_extent_rec *rec;
	struct ocfs2_extent_list *el;
	struct ocfs2_extent_block *eb;
	u32 range;

	ret = ocfs2_extend_trans(handle, subtree_index);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	ret = ocfs2_journal_access_path(et->et_ci, handle, path);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	
	eb = (struct ocfs2_extent_block *)path_leaf_bh(path)->b_data;
	BUG_ON(eb->h_next_leaf_blk != 0ULL);

	el = &eb->h_list;
	BUG_ON(le16_to_cpu(el->l_next_free_rec) == 0);
	idx = le16_to_cpu(el->l_next_free_rec) - 1;
	rec = &el->l_recs[idx];
	range = le32_to_cpu(rec->e_cpos) + ocfs2_rec_clusters(el, rec);

	for (i = 0; i < path->p_tree_depth; i++) {
		el = path->p_node[i].el;
		idx = le16_to_cpu(el->l_next_free_rec) - 1;
		rec = &el->l_recs[idx];

		rec->e_int_clusters = cpu_to_le32(range);
		le32_add_cpu(&rec->e_int_clusters, -le32_to_cpu(rec->e_cpos));

		ocfs2_journal_dirty(handle, path->p_node[i].bh);
	}
out:
	return ret;
}

static void ocfs2_unlink_path(handle_t *handle,
			      struct ocfs2_extent_tree *et,
			      struct ocfs2_cached_dealloc_ctxt *dealloc,
			      struct ocfs2_path *path, int unlink_start)
{
	int ret, i;
	struct ocfs2_extent_block *eb;
	struct ocfs2_extent_list *el;
	struct buffer_head *bh;

	for(i = unlink_start; i < path_num_items(path); i++) {
		bh = path->p_node[i].bh;

		eb = (struct ocfs2_extent_block *)bh->b_data;
		el = &eb->h_list;
		if (le16_to_cpu(el->l_next_free_rec) > 1) {
			mlog(ML_ERROR,
			     "Inode %llu, attempted to remove extent block "
			     "%llu with %u records\n",
			     (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),
			     (unsigned long long)le64_to_cpu(eb->h_blkno),
			     le16_to_cpu(el->l_next_free_rec));

			ocfs2_journal_dirty(handle, bh);
			ocfs2_remove_from_cache(et->et_ci, bh);
			continue;
		}

		el->l_next_free_rec = 0;
		memset(&el->l_recs[0], 0, sizeof(struct ocfs2_extent_rec));

		ocfs2_journal_dirty(handle, bh);

		ret = ocfs2_cache_extent_block_free(dealloc, eb);
		if (ret)
			mlog_errno(ret);

		ocfs2_remove_from_cache(et->et_ci, bh);
	}
}

static void ocfs2_unlink_subtree(handle_t *handle,
				 struct ocfs2_extent_tree *et,
				 struct ocfs2_path *left_path,
				 struct ocfs2_path *right_path,
				 int subtree_index,
				 struct ocfs2_cached_dealloc_ctxt *dealloc)
{
	int i;
	struct buffer_head *root_bh = left_path->p_node[subtree_index].bh;
	struct ocfs2_extent_list *root_el = left_path->p_node[subtree_index].el;
	struct ocfs2_extent_list *el;
	struct ocfs2_extent_block *eb;

	el = path_leaf_el(left_path);

	eb = (struct ocfs2_extent_block *)right_path->p_node[subtree_index + 1].bh->b_data;

	for(i = 1; i < le16_to_cpu(root_el->l_next_free_rec); i++)
		if (root_el->l_recs[i].e_blkno == eb->h_blkno)
			break;

	BUG_ON(i >= le16_to_cpu(root_el->l_next_free_rec));

	memset(&root_el->l_recs[i], 0, sizeof(struct ocfs2_extent_rec));
	le16_add_cpu(&root_el->l_next_free_rec, -1);

	eb = (struct ocfs2_extent_block *)path_leaf_bh(left_path)->b_data;
	eb->h_next_leaf_blk = 0;

	ocfs2_journal_dirty(handle, root_bh);
	ocfs2_journal_dirty(handle, path_leaf_bh(left_path));

	ocfs2_unlink_path(handle, et, dealloc, right_path,
			  subtree_index + 1);
}

static int ocfs2_rotate_subtree_left(handle_t *handle,
				     struct ocfs2_extent_tree *et,
				     struct ocfs2_path *left_path,
				     struct ocfs2_path *right_path,
				     int subtree_index,
				     struct ocfs2_cached_dealloc_ctxt *dealloc,
				     int *deleted)
{
	int ret, i, del_right_subtree = 0, right_has_empty = 0;
	struct buffer_head *root_bh, *et_root_bh = path_root_bh(right_path);
	struct ocfs2_extent_list *right_leaf_el, *left_leaf_el;
	struct ocfs2_extent_block *eb;

	*deleted = 0;

	right_leaf_el = path_leaf_el(right_path);
	left_leaf_el = path_leaf_el(left_path);
	root_bh = left_path->p_node[subtree_index].bh;
	BUG_ON(root_bh != right_path->p_node[subtree_index].bh);

	if (!ocfs2_is_empty_extent(&left_leaf_el->l_recs[0]))
		return 0;

	eb = (struct ocfs2_extent_block *)path_leaf_bh(right_path)->b_data;
	if (ocfs2_is_empty_extent(&right_leaf_el->l_recs[0])) {

		if (eb->h_next_leaf_blk != 0ULL)
			return -EAGAIN;

		if (le16_to_cpu(right_leaf_el->l_next_free_rec) > 1) {
			ret = ocfs2_journal_access_eb(handle, et->et_ci,
						      path_leaf_bh(right_path),
						      OCFS2_JOURNAL_ACCESS_WRITE);
			if (ret) {
				mlog_errno(ret);
				goto out;
			}

			ocfs2_remove_empty_extent(right_leaf_el);
		} else
			right_has_empty = 1;
	}

	if (eb->h_next_leaf_blk == 0ULL &&
	    le16_to_cpu(right_leaf_el->l_next_free_rec) == 1) {
		ret = ocfs2_et_root_journal_access(handle, et,
						   OCFS2_JOURNAL_ACCESS_WRITE);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		del_right_subtree = 1;
	}

	BUG_ON(right_has_empty && !del_right_subtree);

	ret = ocfs2_path_bh_journal_access(handle, et->et_ci, right_path,
					   subtree_index);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	for(i = subtree_index + 1; i < path_num_items(right_path); i++) {
		ret = ocfs2_path_bh_journal_access(handle, et->et_ci,
						   right_path, i);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		ret = ocfs2_path_bh_journal_access(handle, et->et_ci,
						   left_path, i);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}
	}

	if (!right_has_empty) {
		ocfs2_rotate_leaf(left_leaf_el, &right_leaf_el->l_recs[0]);
		memset(&right_leaf_el->l_recs[0], 0,
		       sizeof(struct ocfs2_extent_rec));
	}
	if (eb->h_next_leaf_blk == 0ULL) {
		ocfs2_remove_empty_extent(right_leaf_el);
	}

	ocfs2_journal_dirty(handle, path_leaf_bh(left_path));
	ocfs2_journal_dirty(handle, path_leaf_bh(right_path));

	if (del_right_subtree) {
		ocfs2_unlink_subtree(handle, et, left_path, right_path,
				     subtree_index, dealloc);
		ret = ocfs2_update_edge_lengths(handle, et, subtree_index,
						left_path);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		eb = (struct ocfs2_extent_block *)path_leaf_bh(left_path)->b_data;
		ocfs2_et_set_last_eb_blk(et, le64_to_cpu(eb->h_blkno));

		if (right_has_empty)
			ocfs2_remove_empty_extent(left_leaf_el);

		ocfs2_journal_dirty(handle, et_root_bh);

		*deleted = 1;
	} else
		ocfs2_complete_edge_insert(handle, left_path, right_path,
					   subtree_index);

out:
	return ret;
}

int ocfs2_find_cpos_for_right_leaf(struct super_block *sb,
				   struct ocfs2_path *path, u32 *cpos)
{
	int i, j, ret = 0;
	u64 blkno;
	struct ocfs2_extent_list *el;

	*cpos = 0;

	if (path->p_tree_depth == 0)
		return 0;

	blkno = path_leaf_bh(path)->b_blocknr;

	
	i = path->p_tree_depth - 1;
	while (i >= 0) {
		int next_free;

		el = path->p_node[i].el;

		next_free = le16_to_cpu(el->l_next_free_rec);
		for(j = 0; j < le16_to_cpu(el->l_next_free_rec); j++) {
			if (le64_to_cpu(el->l_recs[j].e_blkno) == blkno) {
				if (j == (next_free - 1)) {
					if (i == 0) {
						goto out;
					}
					goto next_node;
				}

				*cpos = le32_to_cpu(el->l_recs[j + 1].e_cpos);
				goto out;
			}
		}

		ocfs2_error(sb,
			    "Invalid extent tree at extent block %llu\n",
			    (unsigned long long)blkno);
		ret = -EROFS;
		goto out;

next_node:
		blkno = path->p_node[i].bh->b_blocknr;
		i--;
	}

out:
	return ret;
}

static int ocfs2_rotate_rightmost_leaf_left(handle_t *handle,
					    struct ocfs2_extent_tree *et,
					    struct ocfs2_path *path)
{
	int ret;
	struct buffer_head *bh = path_leaf_bh(path);
	struct ocfs2_extent_list *el = path_leaf_el(path);

	if (!ocfs2_is_empty_extent(&el->l_recs[0]))
		return 0;

	ret = ocfs2_path_bh_journal_access(handle, et->et_ci, path,
					   path_num_items(path) - 1);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	ocfs2_remove_empty_extent(el);
	ocfs2_journal_dirty(handle, bh);

out:
	return ret;
}

static int __ocfs2_rotate_tree_left(handle_t *handle,
				    struct ocfs2_extent_tree *et,
				    int orig_credits,
				    struct ocfs2_path *path,
				    struct ocfs2_cached_dealloc_ctxt *dealloc,
				    struct ocfs2_path **empty_extent_path)
{
	int ret, subtree_root, deleted;
	u32 right_cpos;
	struct ocfs2_path *left_path = NULL;
	struct ocfs2_path *right_path = NULL;
	struct super_block *sb = ocfs2_metadata_cache_get_super(et->et_ci);

	BUG_ON(!ocfs2_is_empty_extent(&(path_leaf_el(path)->l_recs[0])));

	*empty_extent_path = NULL;

	ret = ocfs2_find_cpos_for_right_leaf(sb, path, &right_cpos);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	left_path = ocfs2_new_path_from_path(path);
	if (!left_path) {
		ret = -ENOMEM;
		mlog_errno(ret);
		goto out;
	}

	ocfs2_cp_path(left_path, path);

	right_path = ocfs2_new_path_from_path(path);
	if (!right_path) {
		ret = -ENOMEM;
		mlog_errno(ret);
		goto out;
	}

	while (right_cpos) {
		ret = ocfs2_find_path(et->et_ci, right_path, right_cpos);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		subtree_root = ocfs2_find_subtree_root(et, left_path,
						       right_path);

		trace_ocfs2_rotate_subtree(subtree_root,
		     (unsigned long long)
		     right_path->p_node[subtree_root].bh->b_blocknr,
		     right_path->p_tree_depth);

		ret = ocfs2_extend_rotate_transaction(handle, subtree_root,
						      orig_credits, left_path);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		ret = ocfs2_path_bh_journal_access(handle, et->et_ci,
						   left_path, 0);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		ret = ocfs2_rotate_subtree_left(handle, et, left_path,
						right_path, subtree_root,
						dealloc, &deleted);
		if (ret == -EAGAIN) {
			*empty_extent_path = right_path;
			right_path = NULL;
			goto out;
		}
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		if (deleted)
			break;

		ocfs2_mv_path(left_path, right_path);

		ret = ocfs2_find_cpos_for_right_leaf(sb, left_path,
						     &right_cpos);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}
	}

out:
	ocfs2_free_path(right_path);
	ocfs2_free_path(left_path);

	return ret;
}

static int ocfs2_remove_rightmost_path(handle_t *handle,
				struct ocfs2_extent_tree *et,
				struct ocfs2_path *path,
				struct ocfs2_cached_dealloc_ctxt *dealloc)
{
	int ret, subtree_index;
	u32 cpos;
	struct ocfs2_path *left_path = NULL;
	struct ocfs2_extent_block *eb;
	struct ocfs2_extent_list *el;


	ret = ocfs2_et_sanity_check(et);
	if (ret)
		goto out;
	ret = ocfs2_extend_rotate_transaction(handle, 0,
					      handle->h_buffer_credits,
					      path);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	ret = ocfs2_journal_access_path(et->et_ci, handle, path);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	ret = ocfs2_find_cpos_for_left_leaf(ocfs2_metadata_cache_get_super(et->et_ci),
					    path, &cpos);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	if (cpos) {
		left_path = ocfs2_new_path_from_path(path);
		if (!left_path) {
			ret = -ENOMEM;
			mlog_errno(ret);
			goto out;
		}

		ret = ocfs2_find_path(et->et_ci, left_path, cpos);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		ret = ocfs2_journal_access_path(et->et_ci, handle, left_path);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		subtree_index = ocfs2_find_subtree_root(et, left_path, path);

		ocfs2_unlink_subtree(handle, et, left_path, path,
				     subtree_index, dealloc);
		ret = ocfs2_update_edge_lengths(handle, et, subtree_index,
						left_path);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		eb = (struct ocfs2_extent_block *)path_leaf_bh(left_path)->b_data;
		ocfs2_et_set_last_eb_blk(et, le64_to_cpu(eb->h_blkno));
	} else {
		ocfs2_unlink_path(handle, et, dealloc, path, 1);

		el = et->et_root_el;
		el->l_tree_depth = 0;
		el->l_next_free_rec = 0;
		memset(&el->l_recs[0], 0, sizeof(struct ocfs2_extent_rec));

		ocfs2_et_set_last_eb_blk(et, 0);
	}

	ocfs2_journal_dirty(handle, path_root_bh(path));

out:
	ocfs2_free_path(left_path);
	return ret;
}

static int ocfs2_rotate_tree_left(handle_t *handle,
				  struct ocfs2_extent_tree *et,
				  struct ocfs2_path *path,
				  struct ocfs2_cached_dealloc_ctxt *dealloc)
{
	int ret, orig_credits = handle->h_buffer_credits;
	struct ocfs2_path *tmp_path = NULL, *restart_path = NULL;
	struct ocfs2_extent_block *eb;
	struct ocfs2_extent_list *el;

	el = path_leaf_el(path);
	if (!ocfs2_is_empty_extent(&el->l_recs[0]))
		return 0;

	if (path->p_tree_depth == 0) {
rightmost_no_delete:
		ret = ocfs2_rotate_rightmost_leaf_left(handle, et, path);
		if (ret)
			mlog_errno(ret);
		goto out;
	}


	eb = (struct ocfs2_extent_block *)path_leaf_bh(path)->b_data;
	el = &eb->h_list;
	if (eb->h_next_leaf_blk == 0) {
		if (le16_to_cpu(el->l_next_free_rec) > 1)
			goto rightmost_no_delete;

		if (le16_to_cpu(el->l_next_free_rec) == 0) {
			ret = -EIO;
			ocfs2_error(ocfs2_metadata_cache_get_super(et->et_ci),
				    "Owner %llu has empty extent block at %llu",
				    (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),
				    (unsigned long long)le64_to_cpu(eb->h_blkno));
			goto out;
		}


		ret = ocfs2_remove_rightmost_path(handle, et, path,
						  dealloc);
		if (ret)
			mlog_errno(ret);
		goto out;
	}

try_rotate:
	ret = __ocfs2_rotate_tree_left(handle, et, orig_credits, path,
				       dealloc, &restart_path);
	if (ret && ret != -EAGAIN) {
		mlog_errno(ret);
		goto out;
	}

	while (ret == -EAGAIN) {
		tmp_path = restart_path;
		restart_path = NULL;

		ret = __ocfs2_rotate_tree_left(handle, et, orig_credits,
					       tmp_path, dealloc,
					       &restart_path);
		if (ret && ret != -EAGAIN) {
			mlog_errno(ret);
			goto out;
		}

		ocfs2_free_path(tmp_path);
		tmp_path = NULL;

		if (ret == 0)
			goto try_rotate;
	}

out:
	ocfs2_free_path(tmp_path);
	ocfs2_free_path(restart_path);
	return ret;
}

static void ocfs2_cleanup_merge(struct ocfs2_extent_list *el,
				int index)
{
	struct ocfs2_extent_rec *rec = &el->l_recs[index];
	unsigned int size;

	if (rec->e_leaf_clusters == 0) {
		if (index > 0) {
			BUG_ON(ocfs2_is_empty_extent(&el->l_recs[0]));
			size = index * sizeof(struct ocfs2_extent_rec);
			memmove(&el->l_recs[1], &el->l_recs[0], size);
		}

		memset(&el->l_recs[0], 0, sizeof(struct ocfs2_extent_rec));
	}
}

static int ocfs2_get_right_path(struct ocfs2_extent_tree *et,
				struct ocfs2_path *left_path,
				struct ocfs2_path **ret_right_path)
{
	int ret;
	u32 right_cpos;
	struct ocfs2_path *right_path = NULL;
	struct ocfs2_extent_list *left_el;

	*ret_right_path = NULL;

	
	BUG_ON(left_path->p_tree_depth == 0);

	left_el = path_leaf_el(left_path);
	BUG_ON(left_el->l_next_free_rec != left_el->l_count);

	ret = ocfs2_find_cpos_for_right_leaf(ocfs2_metadata_cache_get_super(et->et_ci),
					     left_path, &right_cpos);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	
	BUG_ON(right_cpos == 0);

	right_path = ocfs2_new_path_from_path(left_path);
	if (!right_path) {
		ret = -ENOMEM;
		mlog_errno(ret);
		goto out;
	}

	ret = ocfs2_find_path(et->et_ci, right_path, right_cpos);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	*ret_right_path = right_path;
out:
	if (ret)
		ocfs2_free_path(right_path);
	return ret;
}

static int ocfs2_merge_rec_right(struct ocfs2_path *left_path,
				 handle_t *handle,
				 struct ocfs2_extent_tree *et,
				 struct ocfs2_extent_rec *split_rec,
				 int index)
{
	int ret, next_free, i;
	unsigned int split_clusters = le16_to_cpu(split_rec->e_leaf_clusters);
	struct ocfs2_extent_rec *left_rec;
	struct ocfs2_extent_rec *right_rec;
	struct ocfs2_extent_list *right_el;
	struct ocfs2_path *right_path = NULL;
	int subtree_index = 0;
	struct ocfs2_extent_list *el = path_leaf_el(left_path);
	struct buffer_head *bh = path_leaf_bh(left_path);
	struct buffer_head *root_bh = NULL;

	BUG_ON(index >= le16_to_cpu(el->l_next_free_rec));
	left_rec = &el->l_recs[index];

	if (index == le16_to_cpu(el->l_next_free_rec) - 1 &&
	    le16_to_cpu(el->l_next_free_rec) == le16_to_cpu(el->l_count)) {
		
		ret = ocfs2_get_right_path(et, left_path, &right_path);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		right_el = path_leaf_el(right_path);
		next_free = le16_to_cpu(right_el->l_next_free_rec);
		BUG_ON(next_free <= 0);
		right_rec = &right_el->l_recs[0];
		if (ocfs2_is_empty_extent(right_rec)) {
			BUG_ON(next_free <= 1);
			right_rec = &right_el->l_recs[1];
		}

		BUG_ON(le32_to_cpu(left_rec->e_cpos) +
		       le16_to_cpu(left_rec->e_leaf_clusters) !=
		       le32_to_cpu(right_rec->e_cpos));

		subtree_index = ocfs2_find_subtree_root(et, left_path,
							right_path);

		ret = ocfs2_extend_rotate_transaction(handle, subtree_index,
						      handle->h_buffer_credits,
						      right_path);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		root_bh = left_path->p_node[subtree_index].bh;
		BUG_ON(root_bh != right_path->p_node[subtree_index].bh);

		ret = ocfs2_path_bh_journal_access(handle, et->et_ci, right_path,
						   subtree_index);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		for (i = subtree_index + 1;
		     i < path_num_items(right_path); i++) {
			ret = ocfs2_path_bh_journal_access(handle, et->et_ci,
							   right_path, i);
			if (ret) {
				mlog_errno(ret);
				goto out;
			}

			ret = ocfs2_path_bh_journal_access(handle, et->et_ci,
							   left_path, i);
			if (ret) {
				mlog_errno(ret);
				goto out;
			}
		}

	} else {
		BUG_ON(index == le16_to_cpu(el->l_next_free_rec) - 1);
		right_rec = &el->l_recs[index + 1];
	}

	ret = ocfs2_path_bh_journal_access(handle, et->et_ci, left_path,
					   path_num_items(left_path) - 1);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	le16_add_cpu(&left_rec->e_leaf_clusters, -split_clusters);

	le32_add_cpu(&right_rec->e_cpos, -split_clusters);
	le64_add_cpu(&right_rec->e_blkno,
		     -ocfs2_clusters_to_blocks(ocfs2_metadata_cache_get_super(et->et_ci),
					       split_clusters));
	le16_add_cpu(&right_rec->e_leaf_clusters, split_clusters);

	ocfs2_cleanup_merge(el, index);

	ocfs2_journal_dirty(handle, bh);
	if (right_path) {
		ocfs2_journal_dirty(handle, path_leaf_bh(right_path));
		ocfs2_complete_edge_insert(handle, left_path, right_path,
					   subtree_index);
	}
out:
	if (right_path)
		ocfs2_free_path(right_path);
	return ret;
}

static int ocfs2_get_left_path(struct ocfs2_extent_tree *et,
			       struct ocfs2_path *right_path,
			       struct ocfs2_path **ret_left_path)
{
	int ret;
	u32 left_cpos;
	struct ocfs2_path *left_path = NULL;

	*ret_left_path = NULL;

	
	BUG_ON(right_path->p_tree_depth == 0);

	ret = ocfs2_find_cpos_for_left_leaf(ocfs2_metadata_cache_get_super(et->et_ci),
					    right_path, &left_cpos);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	
	BUG_ON(left_cpos == 0);

	left_path = ocfs2_new_path_from_path(right_path);
	if (!left_path) {
		ret = -ENOMEM;
		mlog_errno(ret);
		goto out;
	}

	ret = ocfs2_find_path(et->et_ci, left_path, left_cpos);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	*ret_left_path = left_path;
out:
	if (ret)
		ocfs2_free_path(left_path);
	return ret;
}

static int ocfs2_merge_rec_left(struct ocfs2_path *right_path,
				handle_t *handle,
				struct ocfs2_extent_tree *et,
				struct ocfs2_extent_rec *split_rec,
				struct ocfs2_cached_dealloc_ctxt *dealloc,
				int index)
{
	int ret, i, subtree_index = 0, has_empty_extent = 0;
	unsigned int split_clusters = le16_to_cpu(split_rec->e_leaf_clusters);
	struct ocfs2_extent_rec *left_rec;
	struct ocfs2_extent_rec *right_rec;
	struct ocfs2_extent_list *el = path_leaf_el(right_path);
	struct buffer_head *bh = path_leaf_bh(right_path);
	struct buffer_head *root_bh = NULL;
	struct ocfs2_path *left_path = NULL;
	struct ocfs2_extent_list *left_el;

	BUG_ON(index < 0);

	right_rec = &el->l_recs[index];
	if (index == 0) {
		
		ret = ocfs2_get_left_path(et, right_path, &left_path);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		left_el = path_leaf_el(left_path);
		BUG_ON(le16_to_cpu(left_el->l_next_free_rec) !=
		       le16_to_cpu(left_el->l_count));

		left_rec = &left_el->l_recs[
				le16_to_cpu(left_el->l_next_free_rec) - 1];
		BUG_ON(le32_to_cpu(left_rec->e_cpos) +
		       le16_to_cpu(left_rec->e_leaf_clusters) !=
		       le32_to_cpu(split_rec->e_cpos));

		subtree_index = ocfs2_find_subtree_root(et, left_path,
							right_path);

		ret = ocfs2_extend_rotate_transaction(handle, subtree_index,
						      handle->h_buffer_credits,
						      left_path);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		root_bh = left_path->p_node[subtree_index].bh;
		BUG_ON(root_bh != right_path->p_node[subtree_index].bh);

		ret = ocfs2_path_bh_journal_access(handle, et->et_ci, right_path,
						   subtree_index);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		for (i = subtree_index + 1;
		     i < path_num_items(right_path); i++) {
			ret = ocfs2_path_bh_journal_access(handle, et->et_ci,
							   right_path, i);
			if (ret) {
				mlog_errno(ret);
				goto out;
			}

			ret = ocfs2_path_bh_journal_access(handle, et->et_ci,
							   left_path, i);
			if (ret) {
				mlog_errno(ret);
				goto out;
			}
		}
	} else {
		left_rec = &el->l_recs[index - 1];
		if (ocfs2_is_empty_extent(&el->l_recs[0]))
			has_empty_extent = 1;
	}

	ret = ocfs2_path_bh_journal_access(handle, et->et_ci, right_path,
					   path_num_items(right_path) - 1);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	if (has_empty_extent && index == 1) {
		*left_rec = *split_rec;

		has_empty_extent = 0;
	} else
		le16_add_cpu(&left_rec->e_leaf_clusters, split_clusters);

	le32_add_cpu(&right_rec->e_cpos, split_clusters);
	le64_add_cpu(&right_rec->e_blkno,
		     ocfs2_clusters_to_blocks(ocfs2_metadata_cache_get_super(et->et_ci),
					      split_clusters));
	le16_add_cpu(&right_rec->e_leaf_clusters, -split_clusters);

	ocfs2_cleanup_merge(el, index);

	ocfs2_journal_dirty(handle, bh);
	if (left_path) {
		ocfs2_journal_dirty(handle, path_leaf_bh(left_path));

		if (le16_to_cpu(right_rec->e_leaf_clusters) == 0 &&
		    le16_to_cpu(el->l_next_free_rec) == 1) {

			ret = ocfs2_remove_rightmost_path(handle, et,
							  right_path,
							  dealloc);
			if (ret) {
				mlog_errno(ret);
				goto out;
			}

			ocfs2_mv_path(right_path, left_path);
			left_path = NULL;
		} else
			ocfs2_complete_edge_insert(handle, left_path,
						   right_path, subtree_index);
	}
out:
	if (left_path)
		ocfs2_free_path(left_path);
	return ret;
}

static int ocfs2_try_to_merge_extent(handle_t *handle,
				     struct ocfs2_extent_tree *et,
				     struct ocfs2_path *path,
				     int split_index,
				     struct ocfs2_extent_rec *split_rec,
				     struct ocfs2_cached_dealloc_ctxt *dealloc,
				     struct ocfs2_merge_ctxt *ctxt)
{
	int ret = 0;
	struct ocfs2_extent_list *el = path_leaf_el(path);
	struct ocfs2_extent_rec *rec = &el->l_recs[split_index];

	BUG_ON(ctxt->c_contig_type == CONTIG_NONE);

	if (ctxt->c_split_covers_rec && ctxt->c_has_empty_extent) {
		ret = ocfs2_rotate_tree_left(handle, et, path, dealloc);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}
		split_index--;
		rec = &el->l_recs[split_index];
	}

	if (ctxt->c_contig_type == CONTIG_LEFTRIGHT) {
		BUG_ON(!ctxt->c_split_covers_rec);

		ret = ocfs2_merge_rec_right(path, handle, et, split_rec,
					    split_index);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		BUG_ON(!ocfs2_is_empty_extent(&el->l_recs[0]));

		
		ret = ocfs2_rotate_tree_left(handle, et, path, dealloc);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		rec = &el->l_recs[split_index];

		ret = ocfs2_merge_rec_left(path, handle, et, rec,
					   dealloc, split_index);

		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		ret = ocfs2_rotate_tree_left(handle, et, path, dealloc);
		if (ret)
			mlog_errno(ret);
		ret = 0;
	} else {
		if (ctxt->c_contig_type == CONTIG_RIGHT) {
			ret = ocfs2_merge_rec_left(path, handle, et,
						   split_rec, dealloc,
						   split_index);
			if (ret) {
				mlog_errno(ret);
				goto out;
			}
		} else {
			ret = ocfs2_merge_rec_right(path, handle,
						    et, split_rec,
						    split_index);
			if (ret) {
				mlog_errno(ret);
				goto out;
			}
		}

		if (ctxt->c_split_covers_rec) {
			ret = ocfs2_rotate_tree_left(handle, et, path,
						     dealloc);
			if (ret)
				mlog_errno(ret);
			ret = 0;
		}
	}

out:
	return ret;
}

static void ocfs2_subtract_from_rec(struct super_block *sb,
				    enum ocfs2_split_type split,
				    struct ocfs2_extent_rec *rec,
				    struct ocfs2_extent_rec *split_rec)
{
	u64 len_blocks;

	len_blocks = ocfs2_clusters_to_blocks(sb,
				le16_to_cpu(split_rec->e_leaf_clusters));

	if (split == SPLIT_LEFT) {
		le32_add_cpu(&rec->e_cpos,
			     le16_to_cpu(split_rec->e_leaf_clusters));
		le64_add_cpu(&rec->e_blkno, len_blocks);
		le16_add_cpu(&rec->e_leaf_clusters,
			     -le16_to_cpu(split_rec->e_leaf_clusters));
	} else {
		le16_add_cpu(&rec->e_leaf_clusters,
			     -le16_to_cpu(split_rec->e_leaf_clusters));
	}
}

static void ocfs2_insert_at_leaf(struct ocfs2_extent_tree *et,
				 struct ocfs2_extent_rec *insert_rec,
				 struct ocfs2_extent_list *el,
				 struct ocfs2_insert_type *insert)
{
	int i = insert->ins_contig_index;
	unsigned int range;
	struct ocfs2_extent_rec *rec;

	BUG_ON(le16_to_cpu(el->l_tree_depth) != 0);

	if (insert->ins_split != SPLIT_NONE) {
		i = ocfs2_search_extent_list(el, le32_to_cpu(insert_rec->e_cpos));
		BUG_ON(i == -1);
		rec = &el->l_recs[i];
		ocfs2_subtract_from_rec(ocfs2_metadata_cache_get_super(et->et_ci),
					insert->ins_split, rec,
					insert_rec);
		goto rotate;
	}

	if (insert->ins_contig != CONTIG_NONE) {
		rec = &el->l_recs[i];
		if (insert->ins_contig == CONTIG_LEFT) {
			rec->e_blkno = insert_rec->e_blkno;
			rec->e_cpos = insert_rec->e_cpos;
		}
		le16_add_cpu(&rec->e_leaf_clusters,
			     le16_to_cpu(insert_rec->e_leaf_clusters));
		return;
	}

	if (le16_to_cpu(el->l_next_free_rec) == 0 ||
	    ((le16_to_cpu(el->l_next_free_rec) == 1) &&
	     ocfs2_is_empty_extent(&el->l_recs[0]))) {
		el->l_recs[0] = *insert_rec;
		el->l_next_free_rec = cpu_to_le16(1);
		return;
	}

	if (insert->ins_appending == APPEND_TAIL) {
		i = le16_to_cpu(el->l_next_free_rec) - 1;
		rec = &el->l_recs[i];
		range = le32_to_cpu(rec->e_cpos)
			+ le16_to_cpu(rec->e_leaf_clusters);
		BUG_ON(le32_to_cpu(insert_rec->e_cpos) < range);

		mlog_bug_on_msg(le16_to_cpu(el->l_next_free_rec) >=
				le16_to_cpu(el->l_count),
				"owner %llu, depth %u, count %u, next free %u, "
				"rec.cpos %u, rec.clusters %u, "
				"insert.cpos %u, insert.clusters %u\n",
				ocfs2_metadata_cache_owner(et->et_ci),
				le16_to_cpu(el->l_tree_depth),
				le16_to_cpu(el->l_count),
				le16_to_cpu(el->l_next_free_rec),
				le32_to_cpu(el->l_recs[i].e_cpos),
				le16_to_cpu(el->l_recs[i].e_leaf_clusters),
				le32_to_cpu(insert_rec->e_cpos),
				le16_to_cpu(insert_rec->e_leaf_clusters));
		i++;
		el->l_recs[i] = *insert_rec;
		le16_add_cpu(&el->l_next_free_rec, 1);
		return;
	}

rotate:
	ocfs2_rotate_leaf(el, insert_rec);
}

static void ocfs2_adjust_rightmost_records(handle_t *handle,
					   struct ocfs2_extent_tree *et,
					   struct ocfs2_path *path,
					   struct ocfs2_extent_rec *insert_rec)
{
	int ret, i, next_free;
	struct buffer_head *bh;
	struct ocfs2_extent_list *el;
	struct ocfs2_extent_rec *rec;

	for (i = 0; i < path->p_tree_depth; i++) {
		bh = path->p_node[i].bh;
		el = path->p_node[i].el;

		next_free = le16_to_cpu(el->l_next_free_rec);
		if (next_free == 0) {
			ocfs2_error(ocfs2_metadata_cache_get_super(et->et_ci),
				    "Owner %llu has a bad extent list",
				    (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci));
			ret = -EIO;
			return;
		}

		rec = &el->l_recs[next_free - 1];

		rec->e_int_clusters = insert_rec->e_cpos;
		le32_add_cpu(&rec->e_int_clusters,
			     le16_to_cpu(insert_rec->e_leaf_clusters));
		le32_add_cpu(&rec->e_int_clusters,
			     -le32_to_cpu(rec->e_cpos));

		ocfs2_journal_dirty(handle, bh);
	}
}

static int ocfs2_append_rec_to_path(handle_t *handle,
				    struct ocfs2_extent_tree *et,
				    struct ocfs2_extent_rec *insert_rec,
				    struct ocfs2_path *right_path,
				    struct ocfs2_path **ret_left_path)
{
	int ret, next_free;
	struct ocfs2_extent_list *el;
	struct ocfs2_path *left_path = NULL;

	*ret_left_path = NULL;

	BUG_ON(right_path->p_tree_depth == 0);

	el = path_leaf_el(right_path);
	next_free = le16_to_cpu(el->l_next_free_rec);
	if (next_free == 0 ||
	    (next_free == 1 && ocfs2_is_empty_extent(&el->l_recs[0]))) {
		u32 left_cpos;

		ret = ocfs2_find_cpos_for_left_leaf(ocfs2_metadata_cache_get_super(et->et_ci),
						    right_path, &left_cpos);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		trace_ocfs2_append_rec_to_path(
			(unsigned long long)
			ocfs2_metadata_cache_owner(et->et_ci),
			le32_to_cpu(insert_rec->e_cpos),
			left_cpos);

		if (left_cpos) {
			left_path = ocfs2_new_path_from_path(right_path);
			if (!left_path) {
				ret = -ENOMEM;
				mlog_errno(ret);
				goto out;
			}

			ret = ocfs2_find_path(et->et_ci, left_path,
					      left_cpos);
			if (ret) {
				mlog_errno(ret);
				goto out;
			}

		}
	}

	ret = ocfs2_journal_access_path(et->et_ci, handle, right_path);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	ocfs2_adjust_rightmost_records(handle, et, right_path, insert_rec);

	*ret_left_path = left_path;
	ret = 0;
out:
	if (ret != 0)
		ocfs2_free_path(left_path);

	return ret;
}

static void ocfs2_split_record(struct ocfs2_extent_tree *et,
			       struct ocfs2_path *left_path,
			       struct ocfs2_path *right_path,
			       struct ocfs2_extent_rec *split_rec,
			       enum ocfs2_split_type split)
{
	int index;
	u32 cpos = le32_to_cpu(split_rec->e_cpos);
	struct ocfs2_extent_list *left_el = NULL, *right_el, *insert_el, *el;
	struct ocfs2_extent_rec *rec, *tmprec;

	right_el = path_leaf_el(right_path);
	if (left_path)
		left_el = path_leaf_el(left_path);

	el = right_el;
	insert_el = right_el;
	index = ocfs2_search_extent_list(el, cpos);
	if (index != -1) {
		if (index == 0 && left_path) {
			BUG_ON(ocfs2_is_empty_extent(&el->l_recs[0]));


			if (split == SPLIT_LEFT) {
				insert_el = left_el;
			} else {
				tmprec = &right_el->l_recs[index];
				ocfs2_rotate_leaf(left_el, tmprec);
				el = left_el;

				memset(tmprec, 0, sizeof(*tmprec));
				index = ocfs2_search_extent_list(left_el, cpos);
				BUG_ON(index == -1);
			}
		}
	} else {
		BUG_ON(!left_path);
		BUG_ON(!ocfs2_is_empty_extent(&left_el->l_recs[0]));
		el = left_el;
		insert_el = left_el;
		index = ocfs2_search_extent_list(el, cpos);
		BUG_ON(index == -1);
	}

	rec = &el->l_recs[index];
	ocfs2_subtract_from_rec(ocfs2_metadata_cache_get_super(et->et_ci),
				split, rec, split_rec);
	ocfs2_rotate_leaf(insert_el, split_rec);
}

static int ocfs2_insert_path(handle_t *handle,
			     struct ocfs2_extent_tree *et,
			     struct ocfs2_path *left_path,
			     struct ocfs2_path *right_path,
			     struct ocfs2_extent_rec *insert_rec,
			     struct ocfs2_insert_type *insert)
{
	int ret, subtree_index;
	struct buffer_head *leaf_bh = path_leaf_bh(right_path);

	if (left_path) {
		ret = ocfs2_extend_trans(handle, left_path->p_tree_depth);
		if (ret < 0) {
			mlog_errno(ret);
			goto out;
		}

		ret = ocfs2_journal_access_path(et->et_ci, handle, left_path);
		if (ret < 0) {
			mlog_errno(ret);
			goto out;
		}
	}

	ret = ocfs2_journal_access_path(et->et_ci, handle, right_path);
	if (ret < 0) {
		mlog_errno(ret);
		goto out;
	}

	if (insert->ins_split != SPLIT_NONE) {
		ocfs2_split_record(et, left_path, right_path,
				   insert_rec, insert->ins_split);

		if (left_path)
			ocfs2_journal_dirty(handle,
					    path_leaf_bh(left_path));
	} else
		ocfs2_insert_at_leaf(et, insert_rec, path_leaf_el(right_path),
				     insert);

	ocfs2_journal_dirty(handle, leaf_bh);

	if (left_path) {
		subtree_index = ocfs2_find_subtree_root(et, left_path,
							right_path);
		ocfs2_complete_edge_insert(handle, left_path, right_path,
					   subtree_index);
	}

	ret = 0;
out:
	return ret;
}

static int ocfs2_do_insert_extent(handle_t *handle,
				  struct ocfs2_extent_tree *et,
				  struct ocfs2_extent_rec *insert_rec,
				  struct ocfs2_insert_type *type)
{
	int ret, rotate = 0;
	u32 cpos;
	struct ocfs2_path *right_path = NULL;
	struct ocfs2_path *left_path = NULL;
	struct ocfs2_extent_list *el;

	el = et->et_root_el;

	ret = ocfs2_et_root_journal_access(handle, et,
					   OCFS2_JOURNAL_ACCESS_WRITE);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	if (le16_to_cpu(el->l_tree_depth) == 0) {
		ocfs2_insert_at_leaf(et, insert_rec, el, type);
		goto out_update_clusters;
	}

	right_path = ocfs2_new_path_from_et(et);
	if (!right_path) {
		ret = -ENOMEM;
		mlog_errno(ret);
		goto out;
	}

	cpos = le32_to_cpu(insert_rec->e_cpos);
	if (type->ins_appending == APPEND_NONE &&
	    type->ins_contig == CONTIG_NONE) {
		rotate = 1;
		cpos = UINT_MAX;
	}

	ret = ocfs2_find_path(et->et_ci, right_path, cpos);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	if (rotate) {
		ret = ocfs2_rotate_tree_right(handle, et, type->ins_split,
					      le32_to_cpu(insert_rec->e_cpos),
					      right_path, &left_path);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		ret = ocfs2_et_root_journal_access(handle, et,
						   OCFS2_JOURNAL_ACCESS_WRITE);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}
	} else if (type->ins_appending == APPEND_TAIL
		   && type->ins_contig != CONTIG_LEFT) {
		ret = ocfs2_append_rec_to_path(handle, et, insert_rec,
					       right_path, &left_path);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}
	}

	ret = ocfs2_insert_path(handle, et, left_path, right_path,
				insert_rec, type);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

out_update_clusters:
	if (type->ins_split == SPLIT_NONE)
		ocfs2_et_update_clusters(et,
					 le16_to_cpu(insert_rec->e_leaf_clusters));

	ocfs2_journal_dirty(handle, et->et_root_bh);

out:
	ocfs2_free_path(left_path);
	ocfs2_free_path(right_path);

	return ret;
}

static enum ocfs2_contig_type
ocfs2_figure_merge_contig_type(struct ocfs2_extent_tree *et,
			       struct ocfs2_path *path,
			       struct ocfs2_extent_list *el, int index,
			       struct ocfs2_extent_rec *split_rec)
{
	int status;
	enum ocfs2_contig_type ret = CONTIG_NONE;
	u32 left_cpos, right_cpos;
	struct ocfs2_extent_rec *rec = NULL;
	struct ocfs2_extent_list *new_el;
	struct ocfs2_path *left_path = NULL, *right_path = NULL;
	struct buffer_head *bh;
	struct ocfs2_extent_block *eb;
	struct super_block *sb = ocfs2_metadata_cache_get_super(et->et_ci);

	if (index > 0) {
		rec = &el->l_recs[index - 1];
	} else if (path->p_tree_depth > 0) {
		status = ocfs2_find_cpos_for_left_leaf(sb, path, &left_cpos);
		if (status)
			goto out;

		if (left_cpos != 0) {
			left_path = ocfs2_new_path_from_path(path);
			if (!left_path)
				goto out;

			status = ocfs2_find_path(et->et_ci, left_path,
						 left_cpos);
			if (status)
				goto out;

			new_el = path_leaf_el(left_path);

			if (le16_to_cpu(new_el->l_next_free_rec) !=
			    le16_to_cpu(new_el->l_count)) {
				bh = path_leaf_bh(left_path);
				eb = (struct ocfs2_extent_block *)bh->b_data;
				ocfs2_error(sb,
					    "Extent block #%llu has an "
					    "invalid l_next_free_rec of "
					    "%d.  It should have "
					    "matched the l_count of %d",
					    (unsigned long long)le64_to_cpu(eb->h_blkno),
					    le16_to_cpu(new_el->l_next_free_rec),
					    le16_to_cpu(new_el->l_count));
				status = -EINVAL;
				goto out;
			}
			rec = &new_el->l_recs[
				le16_to_cpu(new_el->l_next_free_rec) - 1];
		}
	}

	if (rec) {
		if (index == 1 && ocfs2_is_empty_extent(rec)) {
			if (split_rec->e_cpos == el->l_recs[index].e_cpos)
				ret = CONTIG_RIGHT;
		} else {
			ret = ocfs2_et_extent_contig(et, rec, split_rec);
		}
	}

	rec = NULL;
	if (index < (le16_to_cpu(el->l_next_free_rec) - 1))
		rec = &el->l_recs[index + 1];
	else if (le16_to_cpu(el->l_next_free_rec) == le16_to_cpu(el->l_count) &&
		 path->p_tree_depth > 0) {
		status = ocfs2_find_cpos_for_right_leaf(sb, path, &right_cpos);
		if (status)
			goto out;

		if (right_cpos == 0)
			goto out;

		right_path = ocfs2_new_path_from_path(path);
		if (!right_path)
			goto out;

		status = ocfs2_find_path(et->et_ci, right_path, right_cpos);
		if (status)
			goto out;

		new_el = path_leaf_el(right_path);
		rec = &new_el->l_recs[0];
		if (ocfs2_is_empty_extent(rec)) {
			if (le16_to_cpu(new_el->l_next_free_rec) <= 1) {
				bh = path_leaf_bh(right_path);
				eb = (struct ocfs2_extent_block *)bh->b_data;
				ocfs2_error(sb,
					    "Extent block #%llu has an "
					    "invalid l_next_free_rec of %d",
					    (unsigned long long)le64_to_cpu(eb->h_blkno),
					    le16_to_cpu(new_el->l_next_free_rec));
				status = -EINVAL;
				goto out;
			}
			rec = &new_el->l_recs[1];
		}
	}

	if (rec) {
		enum ocfs2_contig_type contig_type;

		contig_type = ocfs2_et_extent_contig(et, rec, split_rec);

		if (contig_type == CONTIG_LEFT && ret == CONTIG_RIGHT)
			ret = CONTIG_LEFTRIGHT;
		else if (ret == CONTIG_NONE)
			ret = contig_type;
	}

out:
	if (left_path)
		ocfs2_free_path(left_path);
	if (right_path)
		ocfs2_free_path(right_path);

	return ret;
}

static void ocfs2_figure_contig_type(struct ocfs2_extent_tree *et,
				     struct ocfs2_insert_type *insert,
				     struct ocfs2_extent_list *el,
				     struct ocfs2_extent_rec *insert_rec)
{
	int i;
	enum ocfs2_contig_type contig_type = CONTIG_NONE;

	BUG_ON(le16_to_cpu(el->l_tree_depth) != 0);

	for(i = 0; i < le16_to_cpu(el->l_next_free_rec); i++) {
		contig_type = ocfs2_et_extent_contig(et, &el->l_recs[i],
						     insert_rec);
		if (contig_type != CONTIG_NONE) {
			insert->ins_contig_index = i;
			break;
		}
	}
	insert->ins_contig = contig_type;

	if (insert->ins_contig != CONTIG_NONE) {
		struct ocfs2_extent_rec *rec =
				&el->l_recs[insert->ins_contig_index];
		unsigned int len = le16_to_cpu(rec->e_leaf_clusters) +
				   le16_to_cpu(insert_rec->e_leaf_clusters);

		if (et->et_max_leaf_clusters &&
		    (len > et->et_max_leaf_clusters))
			insert->ins_contig = CONTIG_NONE;
	}
}

static void ocfs2_figure_appending_type(struct ocfs2_insert_type *insert,
					struct ocfs2_extent_list *el,
					struct ocfs2_extent_rec *insert_rec)
{
	int i;
	u32 cpos = le32_to_cpu(insert_rec->e_cpos);
	struct ocfs2_extent_rec *rec;

	insert->ins_appending = APPEND_NONE;

	BUG_ON(le16_to_cpu(el->l_tree_depth) != 0);

	if (!el->l_next_free_rec)
		goto set_tail_append;

	if (ocfs2_is_empty_extent(&el->l_recs[0])) {
		
		if (le16_to_cpu(el->l_next_free_rec) == 1)
			goto set_tail_append;
	}

	i = le16_to_cpu(el->l_next_free_rec) - 1;
	rec = &el->l_recs[i];

	if (cpos >=
	    (le32_to_cpu(rec->e_cpos) + le16_to_cpu(rec->e_leaf_clusters)))
		goto set_tail_append;

	return;

set_tail_append:
	insert->ins_appending = APPEND_TAIL;
}

static int ocfs2_figure_insert_type(struct ocfs2_extent_tree *et,
				    struct buffer_head **last_eb_bh,
				    struct ocfs2_extent_rec *insert_rec,
				    int *free_records,
				    struct ocfs2_insert_type *insert)
{
	int ret;
	struct ocfs2_extent_block *eb;
	struct ocfs2_extent_list *el;
	struct ocfs2_path *path = NULL;
	struct buffer_head *bh = NULL;

	insert->ins_split = SPLIT_NONE;

	el = et->et_root_el;
	insert->ins_tree_depth = le16_to_cpu(el->l_tree_depth);

	if (el->l_tree_depth) {
		ret = ocfs2_read_extent_block(et->et_ci,
					      ocfs2_et_get_last_eb_blk(et),
					      &bh);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}
		eb = (struct ocfs2_extent_block *) bh->b_data;
		el = &eb->h_list;
	}

	*free_records = le16_to_cpu(el->l_count) -
		le16_to_cpu(el->l_next_free_rec);

	if (!insert->ins_tree_depth) {
		ocfs2_figure_contig_type(et, insert, el, insert_rec);
		ocfs2_figure_appending_type(insert, el, insert_rec);
		return 0;
	}

	path = ocfs2_new_path_from_et(et);
	if (!path) {
		ret = -ENOMEM;
		mlog_errno(ret);
		goto out;
	}

	ret = ocfs2_find_path(et->et_ci, path, le32_to_cpu(insert_rec->e_cpos));
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	el = path_leaf_el(path);

	ocfs2_figure_contig_type(et, insert, el, insert_rec);

	if (insert->ins_contig == CONTIG_LEFT &&
	    insert->ins_contig_index == 0)
		insert->ins_contig = CONTIG_NONE;

	if (ocfs2_et_get_last_eb_blk(et) ==
	    path_leaf_bh(path)->b_blocknr) {
		ocfs2_figure_appending_type(insert, el, insert_rec);
	}

out:
	ocfs2_free_path(path);

	if (ret == 0)
		*last_eb_bh = bh;
	else
		brelse(bh);
	return ret;
}

int ocfs2_insert_extent(handle_t *handle,
			struct ocfs2_extent_tree *et,
			u32 cpos,
			u64 start_blk,
			u32 new_clusters,
			u8 flags,
			struct ocfs2_alloc_context *meta_ac)
{
	int status;
	int uninitialized_var(free_records);
	struct buffer_head *last_eb_bh = NULL;
	struct ocfs2_insert_type insert = {0, };
	struct ocfs2_extent_rec rec;

	trace_ocfs2_insert_extent_start(
		(unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),
		cpos, new_clusters);

	memset(&rec, 0, sizeof(rec));
	rec.e_cpos = cpu_to_le32(cpos);
	rec.e_blkno = cpu_to_le64(start_blk);
	rec.e_leaf_clusters = cpu_to_le16(new_clusters);
	rec.e_flags = flags;
	status = ocfs2_et_insert_check(et, &rec);
	if (status) {
		mlog_errno(status);
		goto bail;
	}

	status = ocfs2_figure_insert_type(et, &last_eb_bh, &rec,
					  &free_records, &insert);
	if (status < 0) {
		mlog_errno(status);
		goto bail;
	}

	trace_ocfs2_insert_extent(insert.ins_appending, insert.ins_contig,
				  insert.ins_contig_index, free_records,
				  insert.ins_tree_depth);

	if (insert.ins_contig == CONTIG_NONE && free_records == 0) {
		status = ocfs2_grow_tree(handle, et,
					 &insert.ins_tree_depth, &last_eb_bh,
					 meta_ac);
		if (status) {
			mlog_errno(status);
			goto bail;
		}
	}

	
	status = ocfs2_do_insert_extent(handle, et, &rec, &insert);
	if (status < 0)
		mlog_errno(status);
	else
		ocfs2_et_extent_map_insert(et, &rec);

bail:
	brelse(last_eb_bh);

	return status;
}

int ocfs2_add_clusters_in_btree(handle_t *handle,
				struct ocfs2_extent_tree *et,
				u32 *logical_offset,
				u32 clusters_to_add,
				int mark_unwritten,
				struct ocfs2_alloc_context *data_ac,
				struct ocfs2_alloc_context *meta_ac,
				enum ocfs2_alloc_restarted *reason_ret)
{
	int status = 0, err = 0;
	int free_extents;
	enum ocfs2_alloc_restarted reason = RESTART_NONE;
	u32 bit_off, num_bits;
	u64 block;
	u8 flags = 0;
	struct ocfs2_super *osb =
		OCFS2_SB(ocfs2_metadata_cache_get_super(et->et_ci));

	BUG_ON(!clusters_to_add);

	if (mark_unwritten)
		flags = OCFS2_EXT_UNWRITTEN;

	free_extents = ocfs2_num_free_extents(osb, et);
	if (free_extents < 0) {
		status = free_extents;
		mlog_errno(status);
		goto leave;
	}

	if (!free_extents && !meta_ac) {
		err = -1;
		status = -EAGAIN;
		reason = RESTART_META;
		goto leave;
	} else if ((!free_extents)
		   && (ocfs2_alloc_context_bits_left(meta_ac)
		       < ocfs2_extend_meta_needed(et->et_root_el))) {
		err = -2;
		status = -EAGAIN;
		reason = RESTART_META;
		goto leave;
	}

	status = __ocfs2_claim_clusters(handle, data_ac, 1,
					clusters_to_add, &bit_off, &num_bits);
	if (status < 0) {
		if (status != -ENOSPC)
			mlog_errno(status);
		goto leave;
	}

	BUG_ON(num_bits > clusters_to_add);

	
	status = ocfs2_et_root_journal_access(handle, et,
					      OCFS2_JOURNAL_ACCESS_WRITE);
	if (status < 0) {
		mlog_errno(status);
		goto leave;
	}

	block = ocfs2_clusters_to_blocks(osb->sb, bit_off);
	trace_ocfs2_add_clusters_in_btree(
	     (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),
	     bit_off, num_bits);
	status = ocfs2_insert_extent(handle, et, *logical_offset, block,
				     num_bits, flags, meta_ac);
	if (status < 0) {
		mlog_errno(status);
		goto leave;
	}

	ocfs2_journal_dirty(handle, et->et_root_bh);

	clusters_to_add -= num_bits;
	*logical_offset += num_bits;

	if (clusters_to_add) {
		err = clusters_to_add;
		status = -EAGAIN;
		reason = RESTART_TRANS;
	}

leave:
	if (reason_ret)
		*reason_ret = reason;
	trace_ocfs2_add_clusters_in_btree_ret(status, reason, err);
	return status;
}

static void ocfs2_make_right_split_rec(struct super_block *sb,
				       struct ocfs2_extent_rec *split_rec,
				       u32 cpos,
				       struct ocfs2_extent_rec *rec)
{
	u32 rec_cpos = le32_to_cpu(rec->e_cpos);
	u32 rec_range = rec_cpos + le16_to_cpu(rec->e_leaf_clusters);

	memset(split_rec, 0, sizeof(struct ocfs2_extent_rec));

	split_rec->e_cpos = cpu_to_le32(cpos);
	split_rec->e_leaf_clusters = cpu_to_le16(rec_range - cpos);

	split_rec->e_blkno = rec->e_blkno;
	le64_add_cpu(&split_rec->e_blkno,
		     ocfs2_clusters_to_blocks(sb, cpos - rec_cpos));

	split_rec->e_flags = rec->e_flags;
}

static int ocfs2_split_and_insert(handle_t *handle,
				  struct ocfs2_extent_tree *et,
				  struct ocfs2_path *path,
				  struct buffer_head **last_eb_bh,
				  int split_index,
				  struct ocfs2_extent_rec *orig_split_rec,
				  struct ocfs2_alloc_context *meta_ac)
{
	int ret = 0, depth;
	unsigned int insert_range, rec_range, do_leftright = 0;
	struct ocfs2_extent_rec tmprec;
	struct ocfs2_extent_list *rightmost_el;
	struct ocfs2_extent_rec rec;
	struct ocfs2_extent_rec split_rec = *orig_split_rec;
	struct ocfs2_insert_type insert;
	struct ocfs2_extent_block *eb;

leftright:
	rec = path_leaf_el(path)->l_recs[split_index];

	rightmost_el = et->et_root_el;

	depth = le16_to_cpu(rightmost_el->l_tree_depth);
	if (depth) {
		BUG_ON(!(*last_eb_bh));
		eb = (struct ocfs2_extent_block *) (*last_eb_bh)->b_data;
		rightmost_el = &eb->h_list;
	}

	if (le16_to_cpu(rightmost_el->l_next_free_rec) ==
	    le16_to_cpu(rightmost_el->l_count)) {
		ret = ocfs2_grow_tree(handle, et,
				      &depth, last_eb_bh, meta_ac);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}
	}

	memset(&insert, 0, sizeof(struct ocfs2_insert_type));
	insert.ins_appending = APPEND_NONE;
	insert.ins_contig = CONTIG_NONE;
	insert.ins_tree_depth = depth;

	insert_range = le32_to_cpu(split_rec.e_cpos) +
		le16_to_cpu(split_rec.e_leaf_clusters);
	rec_range = le32_to_cpu(rec.e_cpos) +
		le16_to_cpu(rec.e_leaf_clusters);

	if (split_rec.e_cpos == rec.e_cpos) {
		insert.ins_split = SPLIT_LEFT;
	} else if (insert_range == rec_range) {
		insert.ins_split = SPLIT_RIGHT;
	} else {
		insert.ins_split = SPLIT_RIGHT;

		ocfs2_make_right_split_rec(ocfs2_metadata_cache_get_super(et->et_ci),
					   &tmprec, insert_range, &rec);

		split_rec = tmprec;

		BUG_ON(do_leftright);
		do_leftright = 1;
	}

	ret = ocfs2_do_insert_extent(handle, et, &split_rec, &insert);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	if (do_leftright == 1) {
		u32 cpos;
		struct ocfs2_extent_list *el;

		do_leftright++;
		split_rec = *orig_split_rec;

		ocfs2_reinit_path(path, 1);

		cpos = le32_to_cpu(split_rec.e_cpos);
		ret = ocfs2_find_path(et->et_ci, path, cpos);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		el = path_leaf_el(path);
		split_index = ocfs2_search_extent_list(el, cpos);
		goto leftright;
	}
out:

	return ret;
}

static int ocfs2_replace_extent_rec(handle_t *handle,
				    struct ocfs2_extent_tree *et,
				    struct ocfs2_path *path,
				    struct ocfs2_extent_list *el,
				    int split_index,
				    struct ocfs2_extent_rec *split_rec)
{
	int ret;

	ret = ocfs2_path_bh_journal_access(handle, et->et_ci, path,
					   path_num_items(path) - 1);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	el->l_recs[split_index] = *split_rec;

	ocfs2_journal_dirty(handle, path_leaf_bh(path));
out:
	return ret;
}

int ocfs2_split_extent(handle_t *handle,
		       struct ocfs2_extent_tree *et,
		       struct ocfs2_path *path,
		       int split_index,
		       struct ocfs2_extent_rec *split_rec,
		       struct ocfs2_alloc_context *meta_ac,
		       struct ocfs2_cached_dealloc_ctxt *dealloc)
{
	int ret = 0;
	struct ocfs2_extent_list *el = path_leaf_el(path);
	struct buffer_head *last_eb_bh = NULL;
	struct ocfs2_extent_rec *rec = &el->l_recs[split_index];
	struct ocfs2_merge_ctxt ctxt;
	struct ocfs2_extent_list *rightmost_el;

	if (le32_to_cpu(rec->e_cpos) > le32_to_cpu(split_rec->e_cpos) ||
	    ((le32_to_cpu(rec->e_cpos) + le16_to_cpu(rec->e_leaf_clusters)) <
	     (le32_to_cpu(split_rec->e_cpos) + le16_to_cpu(split_rec->e_leaf_clusters)))) {
		ret = -EIO;
		mlog_errno(ret);
		goto out;
	}

	ctxt.c_contig_type = ocfs2_figure_merge_contig_type(et, path, el,
							    split_index,
							    split_rec);

	if (path->p_tree_depth) {
		struct ocfs2_extent_block *eb;

		ret = ocfs2_read_extent_block(et->et_ci,
					      ocfs2_et_get_last_eb_blk(et),
					      &last_eb_bh);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		eb = (struct ocfs2_extent_block *) last_eb_bh->b_data;
		rightmost_el = &eb->h_list;
	} else
		rightmost_el = path_root_el(path);

	if (rec->e_cpos == split_rec->e_cpos &&
	    rec->e_leaf_clusters == split_rec->e_leaf_clusters)
		ctxt.c_split_covers_rec = 1;
	else
		ctxt.c_split_covers_rec = 0;

	ctxt.c_has_empty_extent = ocfs2_is_empty_extent(&el->l_recs[0]);

	trace_ocfs2_split_extent(split_index, ctxt.c_contig_type,
				 ctxt.c_has_empty_extent,
				 ctxt.c_split_covers_rec);

	if (ctxt.c_contig_type == CONTIG_NONE) {
		if (ctxt.c_split_covers_rec)
			ret = ocfs2_replace_extent_rec(handle, et, path, el,
						       split_index, split_rec);
		else
			ret = ocfs2_split_and_insert(handle, et, path,
						     &last_eb_bh, split_index,
						     split_rec, meta_ac);
		if (ret)
			mlog_errno(ret);
	} else {
		ret = ocfs2_try_to_merge_extent(handle, et, path,
						split_index, split_rec,
						dealloc, &ctxt);
		if (ret)
			mlog_errno(ret);
	}

out:
	brelse(last_eb_bh);
	return ret;
}

int ocfs2_change_extent_flag(handle_t *handle,
			     struct ocfs2_extent_tree *et,
			     u32 cpos, u32 len, u32 phys,
			     struct ocfs2_alloc_context *meta_ac,
			     struct ocfs2_cached_dealloc_ctxt *dealloc,
			     int new_flags, int clear_flags)
{
	int ret, index;
	struct super_block *sb = ocfs2_metadata_cache_get_super(et->et_ci);
	u64 start_blkno = ocfs2_clusters_to_blocks(sb, phys);
	struct ocfs2_extent_rec split_rec;
	struct ocfs2_path *left_path = NULL;
	struct ocfs2_extent_list *el;
	struct ocfs2_extent_rec *rec;

	left_path = ocfs2_new_path_from_et(et);
	if (!left_path) {
		ret = -ENOMEM;
		mlog_errno(ret);
		goto out;
	}

	ret = ocfs2_find_path(et->et_ci, left_path, cpos);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}
	el = path_leaf_el(left_path);

	index = ocfs2_search_extent_list(el, cpos);
	if (index == -1 || index >= le16_to_cpu(el->l_next_free_rec)) {
		ocfs2_error(sb,
			    "Owner %llu has an extent at cpos %u which can no "
			    "longer be found.\n",
			     (unsigned long long)
			     ocfs2_metadata_cache_owner(et->et_ci), cpos);
		ret = -EROFS;
		goto out;
	}

	ret = -EIO;
	rec = &el->l_recs[index];
	if (new_flags && (rec->e_flags & new_flags)) {
		mlog(ML_ERROR, "Owner %llu tried to set %d flags on an "
		     "extent that already had them",
		     (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),
		     new_flags);
		goto out;
	}

	if (clear_flags && !(rec->e_flags & clear_flags)) {
		mlog(ML_ERROR, "Owner %llu tried to clear %d flags on an "
		     "extent that didn't have them",
		     (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),
		     clear_flags);
		goto out;
	}

	memset(&split_rec, 0, sizeof(struct ocfs2_extent_rec));
	split_rec.e_cpos = cpu_to_le32(cpos);
	split_rec.e_leaf_clusters = cpu_to_le16(len);
	split_rec.e_blkno = cpu_to_le64(start_blkno);
	split_rec.e_flags = rec->e_flags;
	if (new_flags)
		split_rec.e_flags |= new_flags;
	if (clear_flags)
		split_rec.e_flags &= ~clear_flags;

	ret = ocfs2_split_extent(handle, et, left_path,
				 index, &split_rec, meta_ac,
				 dealloc);
	if (ret)
		mlog_errno(ret);

out:
	ocfs2_free_path(left_path);
	return ret;

}

/*
 * Mark the already-existing extent at cpos as written for len clusters.
 * This removes the unwritten extent flag.
 *
 * If the existing extent is larger than the request, initiate a
 * split. An attempt will be made at merging with adjacent extents.
 *
 * The caller is responsible for passing down meta_ac if we'll need it.
 */
int ocfs2_mark_extent_written(struct inode *inode,
			      struct ocfs2_extent_tree *et,
			      handle_t *handle, u32 cpos, u32 len, u32 phys,
			      struct ocfs2_alloc_context *meta_ac,
			      struct ocfs2_cached_dealloc_ctxt *dealloc)
{
	int ret;

	trace_ocfs2_mark_extent_written(
		(unsigned long long)OCFS2_I(inode)->ip_blkno,
		cpos, len, phys);

	if (!ocfs2_writes_unwritten_extents(OCFS2_SB(inode->i_sb))) {
		ocfs2_error(inode->i_sb, "Inode %llu has unwritten extents "
			    "that are being written to, but the feature bit "
			    "is not set in the super block.",
			    (unsigned long long)OCFS2_I(inode)->ip_blkno);
		ret = -EROFS;
		goto out;
	}

	ocfs2_et_extent_map_truncate(et, 0);

	ret = ocfs2_change_extent_flag(handle, et, cpos,
				       len, phys, meta_ac, dealloc,
				       0, OCFS2_EXT_UNWRITTEN);
	if (ret)
		mlog_errno(ret);

out:
	return ret;
}

static int ocfs2_split_tree(handle_t *handle, struct ocfs2_extent_tree *et,
			    struct ocfs2_path *path,
			    int index, u32 new_range,
			    struct ocfs2_alloc_context *meta_ac)
{
	int ret, depth, credits;
	struct buffer_head *last_eb_bh = NULL;
	struct ocfs2_extent_block *eb;
	struct ocfs2_extent_list *rightmost_el, *el;
	struct ocfs2_extent_rec split_rec;
	struct ocfs2_extent_rec *rec;
	struct ocfs2_insert_type insert;

	el = path_leaf_el(path);
	rec = &el->l_recs[index];
	ocfs2_make_right_split_rec(ocfs2_metadata_cache_get_super(et->et_ci),
				   &split_rec, new_range, rec);

	depth = path->p_tree_depth;
	if (depth > 0) {
		ret = ocfs2_read_extent_block(et->et_ci,
					      ocfs2_et_get_last_eb_blk(et),
					      &last_eb_bh);
		if (ret < 0) {
			mlog_errno(ret);
			goto out;
		}

		eb = (struct ocfs2_extent_block *) last_eb_bh->b_data;
		rightmost_el = &eb->h_list;
	} else
		rightmost_el = path_leaf_el(path);

	credits = path->p_tree_depth +
		  ocfs2_extend_meta_needed(et->et_root_el);
	ret = ocfs2_extend_trans(handle, credits);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	if (le16_to_cpu(rightmost_el->l_next_free_rec) ==
	    le16_to_cpu(rightmost_el->l_count)) {
		ret = ocfs2_grow_tree(handle, et, &depth, &last_eb_bh,
				      meta_ac);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}
	}

	memset(&insert, 0, sizeof(struct ocfs2_insert_type));
	insert.ins_appending = APPEND_NONE;
	insert.ins_contig = CONTIG_NONE;
	insert.ins_split = SPLIT_RIGHT;
	insert.ins_tree_depth = depth;

	ret = ocfs2_do_insert_extent(handle, et, &split_rec, &insert);
	if (ret)
		mlog_errno(ret);

out:
	brelse(last_eb_bh);
	return ret;
}

static int ocfs2_truncate_rec(handle_t *handle,
			      struct ocfs2_extent_tree *et,
			      struct ocfs2_path *path, int index,
			      struct ocfs2_cached_dealloc_ctxt *dealloc,
			      u32 cpos, u32 len)
{
	int ret;
	u32 left_cpos, rec_range, trunc_range;
	int wants_rotate = 0, is_rightmost_tree_rec = 0;
	struct super_block *sb = ocfs2_metadata_cache_get_super(et->et_ci);
	struct ocfs2_path *left_path = NULL;
	struct ocfs2_extent_list *el = path_leaf_el(path);
	struct ocfs2_extent_rec *rec;
	struct ocfs2_extent_block *eb;

	if (ocfs2_is_empty_extent(&el->l_recs[0]) && index > 0) {
		ret = ocfs2_rotate_tree_left(handle, et, path, dealloc);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		index--;
	}

	if (index == (le16_to_cpu(el->l_next_free_rec) - 1) &&
	    path->p_tree_depth) {
		eb = (struct ocfs2_extent_block *)path_leaf_bh(path)->b_data;
		if (eb->h_next_leaf_blk == 0)
			is_rightmost_tree_rec = 1;
	}

	rec = &el->l_recs[index];
	if (index == 0 && path->p_tree_depth &&
	    le32_to_cpu(rec->e_cpos) == cpos) {

		ret = ocfs2_find_cpos_for_left_leaf(sb, path, &left_cpos);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		if (left_cpos && le16_to_cpu(el->l_next_free_rec) > 1) {
			left_path = ocfs2_new_path_from_path(path);
			if (!left_path) {
				ret = -ENOMEM;
				mlog_errno(ret);
				goto out;
			}

			ret = ocfs2_find_path(et->et_ci, left_path,
					      left_cpos);
			if (ret) {
				mlog_errno(ret);
				goto out;
			}
		}
	}

	ret = ocfs2_extend_rotate_transaction(handle, 0,
					      handle->h_buffer_credits,
					      path);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	ret = ocfs2_journal_access_path(et->et_ci, handle, path);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	ret = ocfs2_journal_access_path(et->et_ci, handle, left_path);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	rec_range = le32_to_cpu(rec->e_cpos) + ocfs2_rec_clusters(el, rec);
	trunc_range = cpos + len;

	if (le32_to_cpu(rec->e_cpos) == cpos && rec_range == trunc_range) {
		int next_free;

		memset(rec, 0, sizeof(*rec));
		ocfs2_cleanup_merge(el, index);
		wants_rotate = 1;

		next_free = le16_to_cpu(el->l_next_free_rec);
		if (is_rightmost_tree_rec && next_free > 1) {
			rec = &el->l_recs[next_free - 1];
			ocfs2_adjust_rightmost_records(handle, et, path,
						       rec);
		}
	} else if (le32_to_cpu(rec->e_cpos) == cpos) {
		
		le32_add_cpu(&rec->e_cpos, len);
		le64_add_cpu(&rec->e_blkno, ocfs2_clusters_to_blocks(sb, len));
		le16_add_cpu(&rec->e_leaf_clusters, -len);
	} else if (rec_range == trunc_range) {
		
		le16_add_cpu(&rec->e_leaf_clusters, -len);
		if (is_rightmost_tree_rec)
			ocfs2_adjust_rightmost_records(handle, et, path, rec);
	} else {
		
		mlog(ML_ERROR, "Owner %llu: Invalid record truncate: (%u, %u) "
		     "(%u, %u)\n",
		     (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),
		     le32_to_cpu(rec->e_cpos),
		     le16_to_cpu(rec->e_leaf_clusters), cpos, len);
		BUG();
	}

	if (left_path) {
		int subtree_index;

		subtree_index = ocfs2_find_subtree_root(et, left_path, path);
		ocfs2_complete_edge_insert(handle, left_path, path,
					   subtree_index);
	}

	ocfs2_journal_dirty(handle, path_leaf_bh(path));

	ret = ocfs2_rotate_tree_left(handle, et, path, dealloc);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

out:
	ocfs2_free_path(left_path);
	return ret;
}

int ocfs2_remove_extent(handle_t *handle,
			struct ocfs2_extent_tree *et,
			u32 cpos, u32 len,
			struct ocfs2_alloc_context *meta_ac,
			struct ocfs2_cached_dealloc_ctxt *dealloc)
{
	int ret, index;
	u32 rec_range, trunc_range;
	struct ocfs2_extent_rec *rec;
	struct ocfs2_extent_list *el;
	struct ocfs2_path *path = NULL;

	ocfs2_et_extent_map_truncate(et, 0);

	path = ocfs2_new_path_from_et(et);
	if (!path) {
		ret = -ENOMEM;
		mlog_errno(ret);
		goto out;
	}

	ret = ocfs2_find_path(et->et_ci, path, cpos);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	el = path_leaf_el(path);
	index = ocfs2_search_extent_list(el, cpos);
	if (index == -1 || index >= le16_to_cpu(el->l_next_free_rec)) {
		ocfs2_error(ocfs2_metadata_cache_get_super(et->et_ci),
			    "Owner %llu has an extent at cpos %u which can no "
			    "longer be found.\n",
			    (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),
			    cpos);
		ret = -EROFS;
		goto out;
	}

	rec = &el->l_recs[index];
	rec_range = le32_to_cpu(rec->e_cpos) + ocfs2_rec_clusters(el, rec);
	trunc_range = cpos + len;

	BUG_ON(cpos < le32_to_cpu(rec->e_cpos) || trunc_range > rec_range);

	trace_ocfs2_remove_extent(
		(unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),
		cpos, len, index, le32_to_cpu(rec->e_cpos),
		ocfs2_rec_clusters(el, rec));

	if (le32_to_cpu(rec->e_cpos) == cpos || rec_range == trunc_range) {
		ret = ocfs2_truncate_rec(handle, et, path, index, dealloc,
					 cpos, len);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}
	} else {
		ret = ocfs2_split_tree(handle, et, path, index,
				       trunc_range, meta_ac);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		ocfs2_reinit_path(path, 1);

		ret = ocfs2_find_path(et->et_ci, path, cpos);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		el = path_leaf_el(path);
		index = ocfs2_search_extent_list(el, cpos);
		if (index == -1 || index >= le16_to_cpu(el->l_next_free_rec)) {
			ocfs2_error(ocfs2_metadata_cache_get_super(et->et_ci),
				    "Owner %llu: split at cpos %u lost record.",
				    (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),
				    cpos);
			ret = -EROFS;
			goto out;
		}

		rec = &el->l_recs[index];
		rec_range = le32_to_cpu(rec->e_cpos) +
			ocfs2_rec_clusters(el, rec);
		if (rec_range != trunc_range) {
			ocfs2_error(ocfs2_metadata_cache_get_super(et->et_ci),
				    "Owner %llu: error after split at cpos %u"
				    "trunc len %u, existing record is (%u,%u)",
				    (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),
				    cpos, len, le32_to_cpu(rec->e_cpos),
				    ocfs2_rec_clusters(el, rec));
			ret = -EROFS;
			goto out;
		}

		ret = ocfs2_truncate_rec(handle, et, path, index, dealloc,
					 cpos, len);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}
	}

out:
	ocfs2_free_path(path);
	return ret;
}

static int ocfs2_reserve_blocks_for_rec_trunc(struct inode *inode,
					      struct ocfs2_extent_tree *et,
					      u32 extents_to_split,
					      struct ocfs2_alloc_context **ac,
					      int extra_blocks)
{
	int ret = 0, num_free_extents;
	unsigned int max_recs_needed = 2 * extents_to_split;
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);

	*ac = NULL;

	num_free_extents = ocfs2_num_free_extents(osb, et);
	if (num_free_extents < 0) {
		ret = num_free_extents;
		mlog_errno(ret);
		goto out;
	}

	if (!num_free_extents ||
	    (ocfs2_sparse_alloc(osb) && num_free_extents < max_recs_needed))
		extra_blocks += ocfs2_extend_meta_needed(et->et_root_el);

	if (extra_blocks) {
		ret = ocfs2_reserve_new_metadata_blocks(osb, extra_blocks, ac);
		if (ret < 0) {
			if (ret != -ENOSPC)
				mlog_errno(ret);
			goto out;
		}
	}

out:
	if (ret) {
		if (*ac) {
			ocfs2_free_alloc_context(*ac);
			*ac = NULL;
		}
	}

	return ret;
}

int ocfs2_remove_btree_range(struct inode *inode,
			     struct ocfs2_extent_tree *et,
			     u32 cpos, u32 phys_cpos, u32 len, int flags,
			     struct ocfs2_cached_dealloc_ctxt *dealloc,
			     u64 refcount_loc)
{
	int ret, credits = 0, extra_blocks = 0;
	u64 phys_blkno = ocfs2_clusters_to_blocks(inode->i_sb, phys_cpos);
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
	struct inode *tl_inode = osb->osb_tl_inode;
	handle_t *handle;
	struct ocfs2_alloc_context *meta_ac = NULL;
	struct ocfs2_refcount_tree *ref_tree = NULL;

	if ((flags & OCFS2_EXT_REFCOUNTED) && len) {
		BUG_ON(!(OCFS2_I(inode)->ip_dyn_features &
			 OCFS2_HAS_REFCOUNT_FL));

		ret = ocfs2_lock_refcount_tree(osb, refcount_loc, 1,
					       &ref_tree, NULL);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		ret = ocfs2_prepare_refcount_change_for_del(inode,
							    refcount_loc,
							    phys_blkno,
							    len,
							    &credits,
							    &extra_blocks);
		if (ret < 0) {
			mlog_errno(ret);
			goto out;
		}
	}

	ret = ocfs2_reserve_blocks_for_rec_trunc(inode, et, 1, &meta_ac,
						 extra_blocks);
	if (ret) {
		mlog_errno(ret);
		return ret;
	}

	mutex_lock(&tl_inode->i_mutex);

	if (ocfs2_truncate_log_needs_flush(osb)) {
		ret = __ocfs2_flush_truncate_log(osb);
		if (ret < 0) {
			mlog_errno(ret);
			goto out;
		}
	}

	handle = ocfs2_start_trans(osb,
			ocfs2_remove_extent_credits(osb->sb) + credits);
	if (IS_ERR(handle)) {
		ret = PTR_ERR(handle);
		mlog_errno(ret);
		goto out;
	}

	ret = ocfs2_et_root_journal_access(handle, et,
					   OCFS2_JOURNAL_ACCESS_WRITE);
	if (ret) {
		mlog_errno(ret);
		goto out_commit;
	}

	dquot_free_space_nodirty(inode,
				  ocfs2_clusters_to_bytes(inode->i_sb, len));

	ret = ocfs2_remove_extent(handle, et, cpos, len, meta_ac, dealloc);
	if (ret) {
		mlog_errno(ret);
		goto out_commit;
	}

	ocfs2_et_update_clusters(et, -len);

	ocfs2_journal_dirty(handle, et->et_root_bh);

	if (phys_blkno) {
		if (flags & OCFS2_EXT_REFCOUNTED)
			ret = ocfs2_decrease_refcount(inode, handle,
					ocfs2_blocks_to_clusters(osb->sb,
								 phys_blkno),
					len, meta_ac,
					dealloc, 1);
		else
			ret = ocfs2_truncate_log_append(osb, handle,
							phys_blkno, len);
		if (ret)
			mlog_errno(ret);

	}

out_commit:
	ocfs2_commit_trans(osb, handle);
out:
	mutex_unlock(&tl_inode->i_mutex);

	if (meta_ac)
		ocfs2_free_alloc_context(meta_ac);

	if (ref_tree)
		ocfs2_unlock_refcount_tree(osb, ref_tree, 1);

	return ret;
}

int ocfs2_truncate_log_needs_flush(struct ocfs2_super *osb)
{
	struct buffer_head *tl_bh = osb->osb_tl_bh;
	struct ocfs2_dinode *di;
	struct ocfs2_truncate_log *tl;

	di = (struct ocfs2_dinode *) tl_bh->b_data;
	tl = &di->id2.i_dealloc;

	mlog_bug_on_msg(le16_to_cpu(tl->tl_used) > le16_to_cpu(tl->tl_count),
			"slot %d, invalid truncate log parameters: used = "
			"%u, count = %u\n", osb->slot_num,
			le16_to_cpu(tl->tl_used), le16_to_cpu(tl->tl_count));
	return le16_to_cpu(tl->tl_used) == le16_to_cpu(tl->tl_count);
}

static int ocfs2_truncate_log_can_coalesce(struct ocfs2_truncate_log *tl,
					   unsigned int new_start)
{
	unsigned int tail_index;
	unsigned int current_tail;

	
	if (!le16_to_cpu(tl->tl_used))
		return 0;

	tail_index = le16_to_cpu(tl->tl_used) - 1;
	current_tail = le32_to_cpu(tl->tl_recs[tail_index].t_start);
	current_tail += le32_to_cpu(tl->tl_recs[tail_index].t_clusters);

	return current_tail == new_start;
}

int ocfs2_truncate_log_append(struct ocfs2_super *osb,
			      handle_t *handle,
			      u64 start_blk,
			      unsigned int num_clusters)
{
	int status, index;
	unsigned int start_cluster, tl_count;
	struct inode *tl_inode = osb->osb_tl_inode;
	struct buffer_head *tl_bh = osb->osb_tl_bh;
	struct ocfs2_dinode *di;
	struct ocfs2_truncate_log *tl;

	BUG_ON(mutex_trylock(&tl_inode->i_mutex));

	start_cluster = ocfs2_blocks_to_clusters(osb->sb, start_blk);

	di = (struct ocfs2_dinode *) tl_bh->b_data;

	BUG_ON(!OCFS2_IS_VALID_DINODE(di));

	tl = &di->id2.i_dealloc;
	tl_count = le16_to_cpu(tl->tl_count);
	mlog_bug_on_msg(tl_count > ocfs2_truncate_recs_per_inode(osb->sb) ||
			tl_count == 0,
			"Truncate record count on #%llu invalid "
			"wanted %u, actual %u\n",
			(unsigned long long)OCFS2_I(tl_inode)->ip_blkno,
			ocfs2_truncate_recs_per_inode(osb->sb),
			le16_to_cpu(tl->tl_count));

	
	index = le16_to_cpu(tl->tl_used);
	if (index >= tl_count) {
		status = -ENOSPC;
		mlog_errno(status);
		goto bail;
	}

	status = ocfs2_journal_access_di(handle, INODE_CACHE(tl_inode), tl_bh,
					 OCFS2_JOURNAL_ACCESS_WRITE);
	if (status < 0) {
		mlog_errno(status);
		goto bail;
	}

	trace_ocfs2_truncate_log_append(
		(unsigned long long)OCFS2_I(tl_inode)->ip_blkno, index,
		start_cluster, num_clusters);
	if (ocfs2_truncate_log_can_coalesce(tl, start_cluster)) {
		index--;

		num_clusters += le32_to_cpu(tl->tl_recs[index].t_clusters);
		trace_ocfs2_truncate_log_append(
			(unsigned long long)OCFS2_I(tl_inode)->ip_blkno,
			index, le32_to_cpu(tl->tl_recs[index].t_start),
			num_clusters);
	} else {
		tl->tl_recs[index].t_start = cpu_to_le32(start_cluster);
		tl->tl_used = cpu_to_le16(index + 1);
	}
	tl->tl_recs[index].t_clusters = cpu_to_le32(num_clusters);

	ocfs2_journal_dirty(handle, tl_bh);

	osb->truncated_clusters += num_clusters;
bail:
	return status;
}

static int ocfs2_replay_truncate_records(struct ocfs2_super *osb,
					 handle_t *handle,
					 struct inode *data_alloc_inode,
					 struct buffer_head *data_alloc_bh)
{
	int status = 0;
	int i;
	unsigned int num_clusters;
	u64 start_blk;
	struct ocfs2_truncate_rec rec;
	struct ocfs2_dinode *di;
	struct ocfs2_truncate_log *tl;
	struct inode *tl_inode = osb->osb_tl_inode;
	struct buffer_head *tl_bh = osb->osb_tl_bh;

	di = (struct ocfs2_dinode *) tl_bh->b_data;
	tl = &di->id2.i_dealloc;
	i = le16_to_cpu(tl->tl_used) - 1;
	while (i >= 0) {
		status = ocfs2_journal_access_di(handle, INODE_CACHE(tl_inode), tl_bh,
						 OCFS2_JOURNAL_ACCESS_WRITE);
		if (status < 0) {
			mlog_errno(status);
			goto bail;
		}

		tl->tl_used = cpu_to_le16(i);

		ocfs2_journal_dirty(handle, tl_bh);

		status = ocfs2_extend_trans(handle,
					    OCFS2_TRUNCATE_LOG_FLUSH_ONE_REC);
		if (status < 0) {
			mlog_errno(status);
			goto bail;
		}

		rec = tl->tl_recs[i];
		start_blk = ocfs2_clusters_to_blocks(data_alloc_inode->i_sb,
						    le32_to_cpu(rec.t_start));
		num_clusters = le32_to_cpu(rec.t_clusters);

		if (start_blk) {
			trace_ocfs2_replay_truncate_records(
				(unsigned long long)OCFS2_I(tl_inode)->ip_blkno,
				i, le32_to_cpu(rec.t_start), num_clusters);

			status = ocfs2_free_clusters(handle, data_alloc_inode,
						     data_alloc_bh, start_blk,
						     num_clusters);
			if (status < 0) {
				mlog_errno(status);
				goto bail;
			}
		}
		i--;
	}

	osb->truncated_clusters = 0;

bail:
	return status;
}

int __ocfs2_flush_truncate_log(struct ocfs2_super *osb)
{
	int status;
	unsigned int num_to_flush;
	handle_t *handle;
	struct inode *tl_inode = osb->osb_tl_inode;
	struct inode *data_alloc_inode = NULL;
	struct buffer_head *tl_bh = osb->osb_tl_bh;
	struct buffer_head *data_alloc_bh = NULL;
	struct ocfs2_dinode *di;
	struct ocfs2_truncate_log *tl;

	BUG_ON(mutex_trylock(&tl_inode->i_mutex));

	di = (struct ocfs2_dinode *) tl_bh->b_data;

	BUG_ON(!OCFS2_IS_VALID_DINODE(di));

	tl = &di->id2.i_dealloc;
	num_to_flush = le16_to_cpu(tl->tl_used);
	trace_ocfs2_flush_truncate_log(
		(unsigned long long)OCFS2_I(tl_inode)->ip_blkno,
		num_to_flush);
	if (!num_to_flush) {
		status = 0;
		goto out;
	}

	data_alloc_inode = ocfs2_get_system_file_inode(osb,
						       GLOBAL_BITMAP_SYSTEM_INODE,
						       OCFS2_INVALID_SLOT);
	if (!data_alloc_inode) {
		status = -EINVAL;
		mlog(ML_ERROR, "Could not get bitmap inode!\n");
		goto out;
	}

	mutex_lock(&data_alloc_inode->i_mutex);

	status = ocfs2_inode_lock(data_alloc_inode, &data_alloc_bh, 1);
	if (status < 0) {
		mlog_errno(status);
		goto out_mutex;
	}

	handle = ocfs2_start_trans(osb, OCFS2_TRUNCATE_LOG_UPDATE);
	if (IS_ERR(handle)) {
		status = PTR_ERR(handle);
		mlog_errno(status);
		goto out_unlock;
	}

	status = ocfs2_replay_truncate_records(osb, handle, data_alloc_inode,
					       data_alloc_bh);
	if (status < 0)
		mlog_errno(status);

	ocfs2_commit_trans(osb, handle);

out_unlock:
	brelse(data_alloc_bh);
	ocfs2_inode_unlock(data_alloc_inode, 1);

out_mutex:
	mutex_unlock(&data_alloc_inode->i_mutex);
	iput(data_alloc_inode);

out:
	return status;
}

int ocfs2_flush_truncate_log(struct ocfs2_super *osb)
{
	int status;
	struct inode *tl_inode = osb->osb_tl_inode;

	mutex_lock(&tl_inode->i_mutex);
	status = __ocfs2_flush_truncate_log(osb);
	mutex_unlock(&tl_inode->i_mutex);

	return status;
}

static void ocfs2_truncate_log_worker(struct work_struct *work)
{
	int status;
	struct ocfs2_super *osb =
		container_of(work, struct ocfs2_super,
			     osb_truncate_log_wq.work);

	status = ocfs2_flush_truncate_log(osb);
	if (status < 0)
		mlog_errno(status);
	else
		ocfs2_init_steal_slots(osb);
}

#define OCFS2_TRUNCATE_LOG_FLUSH_INTERVAL (2 * HZ)
void ocfs2_schedule_truncate_log_flush(struct ocfs2_super *osb,
				       int cancel)
{
	if (osb->osb_tl_inode) {
		if (cancel)
			cancel_delayed_work(&osb->osb_truncate_log_wq);

		queue_delayed_work(ocfs2_wq, &osb->osb_truncate_log_wq,
				   OCFS2_TRUNCATE_LOG_FLUSH_INTERVAL);
	}
}

static int ocfs2_get_truncate_log_info(struct ocfs2_super *osb,
				       int slot_num,
				       struct inode **tl_inode,
				       struct buffer_head **tl_bh)
{
	int status;
	struct inode *inode = NULL;
	struct buffer_head *bh = NULL;

	inode = ocfs2_get_system_file_inode(osb,
					   TRUNCATE_LOG_SYSTEM_INODE,
					   slot_num);
	if (!inode) {
		status = -EINVAL;
		mlog(ML_ERROR, "Could not get load truncate log inode!\n");
		goto bail;
	}

	status = ocfs2_read_inode_block(inode, &bh);
	if (status < 0) {
		iput(inode);
		mlog_errno(status);
		goto bail;
	}

	*tl_inode = inode;
	*tl_bh    = bh;
bail:
	return status;
}

int ocfs2_begin_truncate_log_recovery(struct ocfs2_super *osb,
				      int slot_num,
				      struct ocfs2_dinode **tl_copy)
{
	int status;
	struct inode *tl_inode = NULL;
	struct buffer_head *tl_bh = NULL;
	struct ocfs2_dinode *di;
	struct ocfs2_truncate_log *tl;

	*tl_copy = NULL;

	trace_ocfs2_begin_truncate_log_recovery(slot_num);

	status = ocfs2_get_truncate_log_info(osb, slot_num, &tl_inode, &tl_bh);
	if (status < 0) {
		mlog_errno(status);
		goto bail;
	}

	di = (struct ocfs2_dinode *) tl_bh->b_data;

	BUG_ON(!OCFS2_IS_VALID_DINODE(di));

	tl = &di->id2.i_dealloc;
	if (le16_to_cpu(tl->tl_used)) {
		trace_ocfs2_truncate_log_recovery_num(le16_to_cpu(tl->tl_used));

		*tl_copy = kmalloc(tl_bh->b_size, GFP_KERNEL);
		if (!(*tl_copy)) {
			status = -ENOMEM;
			mlog_errno(status);
			goto bail;
		}

		memcpy(*tl_copy, tl_bh->b_data, tl_bh->b_size);

		tl->tl_used = 0;

		ocfs2_compute_meta_ecc(osb->sb, tl_bh->b_data, &di->i_check);
		status = ocfs2_write_block(osb, tl_bh, INODE_CACHE(tl_inode));
		if (status < 0) {
			mlog_errno(status);
			goto bail;
		}
	}

bail:
	if (tl_inode)
		iput(tl_inode);
	brelse(tl_bh);

	if (status < 0 && (*tl_copy)) {
		kfree(*tl_copy);
		*tl_copy = NULL;
		mlog_errno(status);
	}

	return status;
}

int ocfs2_complete_truncate_log_recovery(struct ocfs2_super *osb,
					 struct ocfs2_dinode *tl_copy)
{
	int status = 0;
	int i;
	unsigned int clusters, num_recs, start_cluster;
	u64 start_blk;
	handle_t *handle;
	struct inode *tl_inode = osb->osb_tl_inode;
	struct ocfs2_truncate_log *tl;

	if (OCFS2_I(tl_inode)->ip_blkno == le64_to_cpu(tl_copy->i_blkno)) {
		mlog(ML_ERROR, "Asked to recover my own truncate log!\n");
		return -EINVAL;
	}

	tl = &tl_copy->id2.i_dealloc;
	num_recs = le16_to_cpu(tl->tl_used);
	trace_ocfs2_complete_truncate_log_recovery(
		(unsigned long long)le64_to_cpu(tl_copy->i_blkno),
		num_recs);

	mutex_lock(&tl_inode->i_mutex);
	for(i = 0; i < num_recs; i++) {
		if (ocfs2_truncate_log_needs_flush(osb)) {
			status = __ocfs2_flush_truncate_log(osb);
			if (status < 0) {
				mlog_errno(status);
				goto bail_up;
			}
		}

		handle = ocfs2_start_trans(osb, OCFS2_TRUNCATE_LOG_UPDATE);
		if (IS_ERR(handle)) {
			status = PTR_ERR(handle);
			mlog_errno(status);
			goto bail_up;
		}

		clusters = le32_to_cpu(tl->tl_recs[i].t_clusters);
		start_cluster = le32_to_cpu(tl->tl_recs[i].t_start);
		start_blk = ocfs2_clusters_to_blocks(osb->sb, start_cluster);

		status = ocfs2_truncate_log_append(osb, handle,
						   start_blk, clusters);
		ocfs2_commit_trans(osb, handle);
		if (status < 0) {
			mlog_errno(status);
			goto bail_up;
		}
	}

bail_up:
	mutex_unlock(&tl_inode->i_mutex);

	return status;
}

void ocfs2_truncate_log_shutdown(struct ocfs2_super *osb)
{
	int status;
	struct inode *tl_inode = osb->osb_tl_inode;

	if (tl_inode) {
		cancel_delayed_work(&osb->osb_truncate_log_wq);
		flush_workqueue(ocfs2_wq);

		status = ocfs2_flush_truncate_log(osb);
		if (status < 0)
			mlog_errno(status);

		brelse(osb->osb_tl_bh);
		iput(osb->osb_tl_inode);
	}
}

int ocfs2_truncate_log_init(struct ocfs2_super *osb)
{
	int status;
	struct inode *tl_inode = NULL;
	struct buffer_head *tl_bh = NULL;

	status = ocfs2_get_truncate_log_info(osb,
					     osb->slot_num,
					     &tl_inode,
					     &tl_bh);
	if (status < 0)
		mlog_errno(status);

	INIT_DELAYED_WORK(&osb->osb_truncate_log_wq,
			  ocfs2_truncate_log_worker);
	osb->osb_tl_bh    = tl_bh;
	osb->osb_tl_inode = tl_inode;

	return status;
}


struct ocfs2_cached_block_free {
	struct ocfs2_cached_block_free		*free_next;
	u64					free_bg;
	u64					free_blk;
	unsigned int				free_bit;
};

struct ocfs2_per_slot_free_list {
	struct ocfs2_per_slot_free_list		*f_next_suballocator;
	int					f_inode_type;
	int					f_slot;
	struct ocfs2_cached_block_free		*f_first;
};

static int ocfs2_free_cached_blocks(struct ocfs2_super *osb,
				    int sysfile_type,
				    int slot,
				    struct ocfs2_cached_block_free *head)
{
	int ret;
	u64 bg_blkno;
	handle_t *handle;
	struct inode *inode;
	struct buffer_head *di_bh = NULL;
	struct ocfs2_cached_block_free *tmp;

	inode = ocfs2_get_system_file_inode(osb, sysfile_type, slot);
	if (!inode) {
		ret = -EINVAL;
		mlog_errno(ret);
		goto out;
	}

	mutex_lock(&inode->i_mutex);

	ret = ocfs2_inode_lock(inode, &di_bh, 1);
	if (ret) {
		mlog_errno(ret);
		goto out_mutex;
	}

	handle = ocfs2_start_trans(osb, OCFS2_SUBALLOC_FREE);
	if (IS_ERR(handle)) {
		ret = PTR_ERR(handle);
		mlog_errno(ret);
		goto out_unlock;
	}

	while (head) {
		if (head->free_bg)
			bg_blkno = head->free_bg;
		else
			bg_blkno = ocfs2_which_suballoc_group(head->free_blk,
							      head->free_bit);
		trace_ocfs2_free_cached_blocks(
		     (unsigned long long)head->free_blk, head->free_bit);

		ret = ocfs2_free_suballoc_bits(handle, inode, di_bh,
					       head->free_bit, bg_blkno, 1);
		if (ret) {
			mlog_errno(ret);
			goto out_journal;
		}

		ret = ocfs2_extend_trans(handle, OCFS2_SUBALLOC_FREE);
		if (ret) {
			mlog_errno(ret);
			goto out_journal;
		}

		tmp = head;
		head = head->free_next;
		kfree(tmp);
	}

out_journal:
	ocfs2_commit_trans(osb, handle);

out_unlock:
	ocfs2_inode_unlock(inode, 1);
	brelse(di_bh);
out_mutex:
	mutex_unlock(&inode->i_mutex);
	iput(inode);
out:
	while(head) {
		
		tmp = head;
		head = head->free_next;
		kfree(tmp);
	}

	return ret;
}

int ocfs2_cache_cluster_dealloc(struct ocfs2_cached_dealloc_ctxt *ctxt,
				u64 blkno, unsigned int bit)
{
	int ret = 0;
	struct ocfs2_cached_block_free *item;

	item = kzalloc(sizeof(*item), GFP_NOFS);
	if (item == NULL) {
		ret = -ENOMEM;
		mlog_errno(ret);
		return ret;
	}

	trace_ocfs2_cache_cluster_dealloc((unsigned long long)blkno, bit);

	item->free_blk = blkno;
	item->free_bit = bit;
	item->free_next = ctxt->c_global_allocator;

	ctxt->c_global_allocator = item;
	return ret;
}

static int ocfs2_free_cached_clusters(struct ocfs2_super *osb,
				      struct ocfs2_cached_block_free *head)
{
	struct ocfs2_cached_block_free *tmp;
	struct inode *tl_inode = osb->osb_tl_inode;
	handle_t *handle;
	int ret = 0;

	mutex_lock(&tl_inode->i_mutex);

	while (head) {
		if (ocfs2_truncate_log_needs_flush(osb)) {
			ret = __ocfs2_flush_truncate_log(osb);
			if (ret < 0) {
				mlog_errno(ret);
				break;
			}
		}

		handle = ocfs2_start_trans(osb, OCFS2_TRUNCATE_LOG_UPDATE);
		if (IS_ERR(handle)) {
			ret = PTR_ERR(handle);
			mlog_errno(ret);
			break;
		}

		ret = ocfs2_truncate_log_append(osb, handle, head->free_blk,
						head->free_bit);

		ocfs2_commit_trans(osb, handle);
		tmp = head;
		head = head->free_next;
		kfree(tmp);

		if (ret < 0) {
			mlog_errno(ret);
			break;
		}
	}

	mutex_unlock(&tl_inode->i_mutex);

	while (head) {
		
		tmp = head;
		head = head->free_next;
		kfree(tmp);
	}

	return ret;
}

int ocfs2_run_deallocs(struct ocfs2_super *osb,
		       struct ocfs2_cached_dealloc_ctxt *ctxt)
{
	int ret = 0, ret2;
	struct ocfs2_per_slot_free_list *fl;

	if (!ctxt)
		return 0;

	while (ctxt->c_first_suballocator) {
		fl = ctxt->c_first_suballocator;

		if (fl->f_first) {
			trace_ocfs2_run_deallocs(fl->f_inode_type,
						 fl->f_slot);
			ret2 = ocfs2_free_cached_blocks(osb,
							fl->f_inode_type,
							fl->f_slot,
							fl->f_first);
			if (ret2)
				mlog_errno(ret2);
			if (!ret)
				ret = ret2;
		}

		ctxt->c_first_suballocator = fl->f_next_suballocator;
		kfree(fl);
	}

	if (ctxt->c_global_allocator) {
		ret2 = ocfs2_free_cached_clusters(osb,
						  ctxt->c_global_allocator);
		if (ret2)
			mlog_errno(ret2);
		if (!ret)
			ret = ret2;

		ctxt->c_global_allocator = NULL;
	}

	return ret;
}

static struct ocfs2_per_slot_free_list *
ocfs2_find_per_slot_free_list(int type,
			      int slot,
			      struct ocfs2_cached_dealloc_ctxt *ctxt)
{
	struct ocfs2_per_slot_free_list *fl = ctxt->c_first_suballocator;

	while (fl) {
		if (fl->f_inode_type == type && fl->f_slot == slot)
			return fl;

		fl = fl->f_next_suballocator;
	}

	fl = kmalloc(sizeof(*fl), GFP_NOFS);
	if (fl) {
		fl->f_inode_type = type;
		fl->f_slot = slot;
		fl->f_first = NULL;
		fl->f_next_suballocator = ctxt->c_first_suballocator;

		ctxt->c_first_suballocator = fl;
	}
	return fl;
}

int ocfs2_cache_block_dealloc(struct ocfs2_cached_dealloc_ctxt *ctxt,
			      int type, int slot, u64 suballoc,
			      u64 blkno, unsigned int bit)
{
	int ret;
	struct ocfs2_per_slot_free_list *fl;
	struct ocfs2_cached_block_free *item;

	fl = ocfs2_find_per_slot_free_list(type, slot, ctxt);
	if (fl == NULL) {
		ret = -ENOMEM;
		mlog_errno(ret);
		goto out;
	}

	item = kzalloc(sizeof(*item), GFP_NOFS);
	if (item == NULL) {
		ret = -ENOMEM;
		mlog_errno(ret);
		goto out;
	}

	trace_ocfs2_cache_block_dealloc(type, slot,
					(unsigned long long)suballoc,
					(unsigned long long)blkno, bit);

	item->free_bg = suballoc;
	item->free_blk = blkno;
	item->free_bit = bit;
	item->free_next = fl->f_first;

	fl->f_first = item;

	ret = 0;
out:
	return ret;
}

static int ocfs2_cache_extent_block_free(struct ocfs2_cached_dealloc_ctxt *ctxt,
					 struct ocfs2_extent_block *eb)
{
	return ocfs2_cache_block_dealloc(ctxt, EXTENT_ALLOC_SYSTEM_INODE,
					 le16_to_cpu(eb->h_suballoc_slot),
					 le64_to_cpu(eb->h_suballoc_loc),
					 le64_to_cpu(eb->h_blkno),
					 le16_to_cpu(eb->h_suballoc_bit));
}

static int ocfs2_zero_func(handle_t *handle, struct buffer_head *bh)
{
	set_buffer_uptodate(bh);
	mark_buffer_dirty(bh);
	return 0;
}

void ocfs2_map_and_dirty_page(struct inode *inode, handle_t *handle,
			      unsigned int from, unsigned int to,
			      struct page *page, int zero, u64 *phys)
{
	int ret, partial = 0;

	ret = ocfs2_map_page_blocks(page, phys, inode, from, to, 0);
	if (ret)
		mlog_errno(ret);

	if (zero)
		zero_user_segment(page, from, to);

	ret = walk_page_buffers(handle, page_buffers(page),
				from, to, &partial,
				ocfs2_zero_func);
	if (ret < 0)
		mlog_errno(ret);
	else if (ocfs2_should_order_data(inode)) {
		ret = ocfs2_jbd2_file_inode(handle, inode);
		if (ret < 0)
			mlog_errno(ret);
	}

	if (!partial)
		SetPageUptodate(page);

	flush_dcache_page(page);
}

static void ocfs2_zero_cluster_pages(struct inode *inode, loff_t start,
				     loff_t end, struct page **pages,
				     int numpages, u64 phys, handle_t *handle)
{
	int i;
	struct page *page;
	unsigned int from, to = PAGE_CACHE_SIZE;
	struct super_block *sb = inode->i_sb;

	BUG_ON(!ocfs2_sparse_alloc(OCFS2_SB(sb)));

	if (numpages == 0)
		goto out;

	to = PAGE_CACHE_SIZE;
	for(i = 0; i < numpages; i++) {
		page = pages[i];

		from = start & (PAGE_CACHE_SIZE - 1);
		if ((end >> PAGE_CACHE_SHIFT) == page->index)
			to = end & (PAGE_CACHE_SIZE - 1);

		BUG_ON(from > PAGE_CACHE_SIZE);
		BUG_ON(to > PAGE_CACHE_SIZE);

		ocfs2_map_and_dirty_page(inode, handle, from, to, page, 1,
					 &phys);

		start = (page->index + 1) << PAGE_CACHE_SHIFT;
	}
out:
	if (pages)
		ocfs2_unlock_and_free_pages(pages, numpages);
}

int ocfs2_grab_pages(struct inode *inode, loff_t start, loff_t end,
		     struct page **pages, int *num)
{
	int numpages, ret = 0;
	struct address_space *mapping = inode->i_mapping;
	unsigned long index;
	loff_t last_page_bytes;

	BUG_ON(start > end);

	numpages = 0;
	last_page_bytes = PAGE_ALIGN(end);
	index = start >> PAGE_CACHE_SHIFT;
	do {
		pages[numpages] = find_or_create_page(mapping, index, GFP_NOFS);
		if (!pages[numpages]) {
			ret = -ENOMEM;
			mlog_errno(ret);
			goto out;
		}

		numpages++;
		index++;
	} while (index < (last_page_bytes >> PAGE_CACHE_SHIFT));

out:
	if (ret != 0) {
		if (pages)
			ocfs2_unlock_and_free_pages(pages, numpages);
		numpages = 0;
	}

	*num = numpages;

	return ret;
}

static int ocfs2_grab_eof_pages(struct inode *inode, loff_t start, loff_t end,
				struct page **pages, int *num)
{
	struct super_block *sb = inode->i_sb;

	BUG_ON(start >> OCFS2_SB(sb)->s_clustersize_bits !=
	       (end - 1) >> OCFS2_SB(sb)->s_clustersize_bits);

	return ocfs2_grab_pages(inode, start, end, pages, num);
}

int ocfs2_zero_range_for_truncate(struct inode *inode, handle_t *handle,
				  u64 range_start, u64 range_end)
{
	int ret = 0, numpages;
	struct page **pages = NULL;
	u64 phys;
	unsigned int ext_flags;
	struct super_block *sb = inode->i_sb;

	if (!ocfs2_sparse_alloc(OCFS2_SB(sb)))
		return 0;

	pages = kcalloc(ocfs2_pages_per_cluster(sb),
			sizeof(struct page *), GFP_NOFS);
	if (pages == NULL) {
		ret = -ENOMEM;
		mlog_errno(ret);
		goto out;
	}

	if (range_start == range_end)
		goto out;

	ret = ocfs2_extent_map_get_blocks(inode,
					  range_start >> sb->s_blocksize_bits,
					  &phys, NULL, &ext_flags);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	/*
	 * Tail is a hole, or is marked unwritten. In either case, we
	 * can count on read and write to return/push zero's.
	 */
	if (phys == 0 || ext_flags & OCFS2_EXT_UNWRITTEN)
		goto out;

	ret = ocfs2_grab_eof_pages(inode, range_start, range_end, pages,
				   &numpages);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	ocfs2_zero_cluster_pages(inode, range_start, range_end, pages,
				 numpages, phys, handle);

	ret = filemap_fdatawrite_range(inode->i_mapping, range_start,
				       range_end - 1);
	if (ret)
		mlog_errno(ret);

out:
	if (pages)
		kfree(pages);

	return ret;
}

static void ocfs2_zero_dinode_id2_with_xattr(struct inode *inode,
					     struct ocfs2_dinode *di)
{
	unsigned int blocksize = 1 << inode->i_sb->s_blocksize_bits;
	unsigned int xattrsize = le16_to_cpu(di->i_xattr_inline_size);

	if (le16_to_cpu(di->i_dyn_features) & OCFS2_INLINE_XATTR_FL)
		memset(&di->id2, 0, blocksize -
				    offsetof(struct ocfs2_dinode, id2) -
				    xattrsize);
	else
		memset(&di->id2, 0, blocksize -
				    offsetof(struct ocfs2_dinode, id2));
}

void ocfs2_dinode_new_extent_list(struct inode *inode,
				  struct ocfs2_dinode *di)
{
	ocfs2_zero_dinode_id2_with_xattr(inode, di);
	di->id2.i_list.l_tree_depth = 0;
	di->id2.i_list.l_next_free_rec = 0;
	di->id2.i_list.l_count = cpu_to_le16(
		ocfs2_extent_recs_per_inode_with_xattr(inode->i_sb, di));
}

void ocfs2_set_inode_data_inline(struct inode *inode, struct ocfs2_dinode *di)
{
	struct ocfs2_inode_info *oi = OCFS2_I(inode);
	struct ocfs2_inline_data *idata = &di->id2.i_data;

	spin_lock(&oi->ip_lock);
	oi->ip_dyn_features |= OCFS2_INLINE_DATA_FL;
	di->i_dyn_features = cpu_to_le16(oi->ip_dyn_features);
	spin_unlock(&oi->ip_lock);

	ocfs2_zero_dinode_id2_with_xattr(inode, di);

	idata->id_count = cpu_to_le16(
			ocfs2_max_inline_data_with_xattr(inode->i_sb, di));
}

int ocfs2_convert_inline_data_to_extents(struct inode *inode,
					 struct buffer_head *di_bh)
{
	int ret, i, has_data, num_pages = 0;
	handle_t *handle;
	u64 uninitialized_var(block);
	struct ocfs2_inode_info *oi = OCFS2_I(inode);
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
	struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
	struct ocfs2_alloc_context *data_ac = NULL;
	struct page **pages = NULL;
	loff_t end = osb->s_clustersize;
	struct ocfs2_extent_tree et;
	int did_quota = 0;

	has_data = i_size_read(inode) ? 1 : 0;

	if (has_data) {
		pages = kcalloc(ocfs2_pages_per_cluster(osb->sb),
				sizeof(struct page *), GFP_NOFS);
		if (pages == NULL) {
			ret = -ENOMEM;
			mlog_errno(ret);
			goto out;
		}

		ret = ocfs2_reserve_clusters(osb, 1, &data_ac);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}
	}

	handle = ocfs2_start_trans(osb,
				   ocfs2_inline_to_extents_credits(osb->sb));
	if (IS_ERR(handle)) {
		ret = PTR_ERR(handle);
		mlog_errno(ret);
		goto out_unlock;
	}

	ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
				      OCFS2_JOURNAL_ACCESS_WRITE);
	if (ret) {
		mlog_errno(ret);
		goto out_commit;
	}

	if (has_data) {
		u32 bit_off, num;
		unsigned int page_end;
		u64 phys;

		ret = dquot_alloc_space_nodirty(inode,
				       ocfs2_clusters_to_bytes(osb->sb, 1));
		if (ret)
			goto out_commit;
		did_quota = 1;

		data_ac->ac_resv = &OCFS2_I(inode)->ip_la_data_resv;

		ret = ocfs2_claim_clusters(handle, data_ac, 1, &bit_off,
					   &num);
		if (ret) {
			mlog_errno(ret);
			goto out_commit;
		}

		block = phys = ocfs2_clusters_to_blocks(inode->i_sb, bit_off);

		if (!ocfs2_sparse_alloc(osb) &&
		    PAGE_CACHE_SIZE < osb->s_clustersize)
			end = PAGE_CACHE_SIZE;

		ret = ocfs2_grab_eof_pages(inode, 0, end, pages, &num_pages);
		if (ret) {
			mlog_errno(ret);
			goto out_commit;
		}

		ret = ocfs2_read_inline_data(inode, pages[0], di_bh);
		if (ret) {
			mlog_errno(ret);
			goto out_commit;
		}

		page_end = PAGE_CACHE_SIZE;
		if (PAGE_CACHE_SIZE > osb->s_clustersize)
			page_end = osb->s_clustersize;

		for (i = 0; i < num_pages; i++)
			ocfs2_map_and_dirty_page(inode, handle, 0, page_end,
						 pages[i], i > 0, &phys);
	}

	spin_lock(&oi->ip_lock);
	oi->ip_dyn_features &= ~OCFS2_INLINE_DATA_FL;
	di->i_dyn_features = cpu_to_le16(oi->ip_dyn_features);
	spin_unlock(&oi->ip_lock);

	ocfs2_dinode_new_extent_list(inode, di);

	ocfs2_journal_dirty(handle, di_bh);

	if (has_data) {
		ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(inode), di_bh);
		ret = ocfs2_insert_extent(handle, &et, 0, block, 1, 0, NULL);
		if (ret) {
			mlog_errno(ret);
			goto out_commit;
		}

		inode->i_blocks = ocfs2_inode_sector_count(inode);
	}

out_commit:
	if (ret < 0 && did_quota)
		dquot_free_space_nodirty(inode,
					  ocfs2_clusters_to_bytes(osb->sb, 1));

	ocfs2_commit_trans(osb, handle);

out_unlock:
	if (data_ac)
		ocfs2_free_alloc_context(data_ac);

out:
	if (pages) {
		ocfs2_unlock_and_free_pages(pages, num_pages);
		kfree(pages);
	}

	return ret;
}

int ocfs2_commit_truncate(struct ocfs2_super *osb,
			  struct inode *inode,
			  struct buffer_head *di_bh)
{
	int status = 0, i, flags = 0;
	u32 new_highest_cpos, range, trunc_cpos, trunc_len, phys_cpos, coff;
	u64 blkno = 0;
	struct ocfs2_extent_list *el;
	struct ocfs2_extent_rec *rec;
	struct ocfs2_path *path = NULL;
	struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
	struct ocfs2_extent_list *root_el = &(di->id2.i_list);
	u64 refcount_loc = le64_to_cpu(di->i_refcount_loc);
	struct ocfs2_extent_tree et;
	struct ocfs2_cached_dealloc_ctxt dealloc;

	ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(inode), di_bh);
	ocfs2_init_dealloc_ctxt(&dealloc);

	new_highest_cpos = ocfs2_clusters_for_bytes(osb->sb,
						     i_size_read(inode));

	path = ocfs2_new_path(di_bh, &di->id2.i_list,
			      ocfs2_journal_access_di);
	if (!path) {
		status = -ENOMEM;
		mlog_errno(status);
		goto bail;
	}

	ocfs2_extent_map_trunc(inode, new_highest_cpos);

start:
	if (OCFS2_I(inode)->ip_clusters == 0) {
		status = 0;
		goto bail;
	}

	status = ocfs2_find_path(INODE_CACHE(inode), path, UINT_MAX);
	if (status) {
		mlog_errno(status);
		goto bail;
	}

	trace_ocfs2_commit_truncate(
		(unsigned long long)OCFS2_I(inode)->ip_blkno,
		new_highest_cpos,
		OCFS2_I(inode)->ip_clusters,
		path->p_tree_depth);

	el = path_leaf_el(path);
	if (le16_to_cpu(el->l_next_free_rec) == 0) {
		ocfs2_error(inode->i_sb,
			    "Inode %llu has empty extent block at %llu\n",
			    (unsigned long long)OCFS2_I(inode)->ip_blkno,
			    (unsigned long long)path_leaf_bh(path)->b_blocknr);
		status = -EROFS;
		goto bail;
	}

	i = le16_to_cpu(el->l_next_free_rec) - 1;
	rec = &el->l_recs[i];
	flags = rec->e_flags;
	range = le32_to_cpu(rec->e_cpos) + ocfs2_rec_clusters(el, rec);

	if (i == 0 && ocfs2_is_empty_extent(rec)) {
		if (root_el->l_tree_depth && rec->e_int_clusters == 0) {
			ocfs2_error(inode->i_sb, "Inode %lu has an empty "
				    "extent record, depth %u\n", inode->i_ino,
				    le16_to_cpu(root_el->l_tree_depth));
			status = -EROFS;
			goto bail;
		}
		trunc_cpos = le32_to_cpu(rec->e_cpos);
		trunc_len = 0;
		blkno = 0;
	} else if (le32_to_cpu(rec->e_cpos) >= new_highest_cpos) {
		trunc_cpos = le32_to_cpu(rec->e_cpos);
		trunc_len = ocfs2_rec_clusters(el, rec);
		blkno = le64_to_cpu(rec->e_blkno);
	} else if (range > new_highest_cpos) {
		trunc_cpos = new_highest_cpos;
		trunc_len = range - new_highest_cpos;
		coff = new_highest_cpos - le32_to_cpu(rec->e_cpos);
		blkno = le64_to_cpu(rec->e_blkno) +
				ocfs2_clusters_to_blocks(inode->i_sb, coff);
	} else {
		status = 0;
		goto bail;
	}

	phys_cpos = ocfs2_blocks_to_clusters(inode->i_sb, blkno);

	status = ocfs2_remove_btree_range(inode, &et, trunc_cpos,
					  phys_cpos, trunc_len, flags, &dealloc,
					  refcount_loc);
	if (status < 0) {
		mlog_errno(status);
		goto bail;
	}

	ocfs2_reinit_path(path, 1);

	goto start;

bail:

	ocfs2_schedule_truncate_log_flush(osb, 1);

	ocfs2_run_deallocs(osb, &dealloc);

	ocfs2_free_path(path);

	return status;
}

int ocfs2_truncate_inline(struct inode *inode, struct buffer_head *di_bh,
			  unsigned int start, unsigned int end, int trunc)
{
	int ret;
	unsigned int numbytes;
	handle_t *handle;
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
	struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
	struct ocfs2_inline_data *idata = &di->id2.i_data;

	if (end > i_size_read(inode))
		end = i_size_read(inode);

	BUG_ON(start >= end);

	if (!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) ||
	    !(le16_to_cpu(di->i_dyn_features) & OCFS2_INLINE_DATA_FL) ||
	    !ocfs2_supports_inline_data(osb)) {
		ocfs2_error(inode->i_sb,
			    "Inline data flags for inode %llu don't agree! "
			    "Disk: 0x%x, Memory: 0x%x, Superblock: 0x%x\n",
			    (unsigned long long)OCFS2_I(inode)->ip_blkno,
			    le16_to_cpu(di->i_dyn_features),
			    OCFS2_I(inode)->ip_dyn_features,
			    osb->s_feature_incompat);
		ret = -EROFS;
		goto out;
	}

	handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
	if (IS_ERR(handle)) {
		ret = PTR_ERR(handle);
		mlog_errno(ret);
		goto out;
	}

	ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
				      OCFS2_JOURNAL_ACCESS_WRITE);
	if (ret) {
		mlog_errno(ret);
		goto out_commit;
	}

	numbytes = end - start;
	memset(idata->id_data + start, 0, numbytes);

	if (trunc) {
		i_size_write(inode, start);
		di->i_size = cpu_to_le64(start);
	}

	inode->i_blocks = ocfs2_inode_sector_count(inode);
	inode->i_ctime = inode->i_mtime = CURRENT_TIME;

	di->i_ctime = di->i_mtime = cpu_to_le64(inode->i_ctime.tv_sec);
	di->i_ctime_nsec = di->i_mtime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);

	ocfs2_journal_dirty(handle, di_bh);

out_commit:
	ocfs2_commit_trans(osb, handle);

out:
	return ret;
}

static int ocfs2_trim_extent(struct super_block *sb,
			     struct ocfs2_group_desc *gd,
			     u32 start, u32 count)
{
	u64 discard, bcount;

	bcount = ocfs2_clusters_to_blocks(sb, count);
	discard = le64_to_cpu(gd->bg_blkno) +
			ocfs2_clusters_to_blocks(sb, start);

	trace_ocfs2_trim_extent(sb, (unsigned long long)discard, bcount);

	return sb_issue_discard(sb, discard, bcount, GFP_NOFS, 0);
}

static int ocfs2_trim_group(struct super_block *sb,
			    struct ocfs2_group_desc *gd,
			    u32 start, u32 max, u32 minbits)
{
	int ret = 0, count = 0, next;
	void *bitmap = gd->bg_bitmap;

	if (le16_to_cpu(gd->bg_free_bits_count) < minbits)
		return 0;

	trace_ocfs2_trim_group((unsigned long long)le64_to_cpu(gd->bg_blkno),
			       start, max, minbits);

	while (start < max) {
		start = ocfs2_find_next_zero_bit(bitmap, max, start);
		if (start >= max)
			break;
		next = ocfs2_find_next_bit(bitmap, max, start);

		if ((next - start) >= minbits) {
			ret = ocfs2_trim_extent(sb, gd,
						start, next - start);
			if (ret < 0) {
				mlog_errno(ret);
				break;
			}
			count += next - start;
		}
		start = next + 1;

		if (fatal_signal_pending(current)) {
			count = -ERESTARTSYS;
			break;
		}

		if ((le16_to_cpu(gd->bg_free_bits_count) - count) < minbits)
			break;
	}

	if (ret < 0)
		count = ret;

	return count;
}

int ocfs2_trim_fs(struct super_block *sb, struct fstrim_range *range)
{
	struct ocfs2_super *osb = OCFS2_SB(sb);
	u64 start, len, trimmed, first_group, last_group, group;
	int ret, cnt;
	u32 first_bit, last_bit, minlen;
	struct buffer_head *main_bm_bh = NULL;
	struct inode *main_bm_inode = NULL;
	struct buffer_head *gd_bh = NULL;
	struct ocfs2_dinode *main_bm;
	struct ocfs2_group_desc *gd = NULL;

	start = range->start >> osb->s_clustersize_bits;
	len = range->len >> osb->s_clustersize_bits;
	minlen = range->minlen >> osb->s_clustersize_bits;
	trimmed = 0;

	if (!len) {
		range->len = 0;
		return 0;
	}

	if (minlen >= osb->bitmap_cpg)
		return -EINVAL;

	main_bm_inode = ocfs2_get_system_file_inode(osb,
						    GLOBAL_BITMAP_SYSTEM_INODE,
						    OCFS2_INVALID_SLOT);
	if (!main_bm_inode) {
		ret = -EIO;
		mlog_errno(ret);
		goto out;
	}

	mutex_lock(&main_bm_inode->i_mutex);

	ret = ocfs2_inode_lock(main_bm_inode, &main_bm_bh, 0);
	if (ret < 0) {
		mlog_errno(ret);
		goto out_mutex;
	}
	main_bm = (struct ocfs2_dinode *)main_bm_bh->b_data;

	if (start >= le32_to_cpu(main_bm->i_clusters)) {
		ret = -EINVAL;
		goto out_unlock;
	}

	if (start + len > le32_to_cpu(main_bm->i_clusters))
		len = le32_to_cpu(main_bm->i_clusters) - start;

	trace_ocfs2_trim_fs(start, len, minlen);

	
	first_group = ocfs2_which_cluster_group(main_bm_inode, start);
	if (first_group == osb->first_cluster_group_blkno)
		first_bit = start;
	else
		first_bit = start - ocfs2_blocks_to_clusters(sb, first_group);
	last_group = ocfs2_which_cluster_group(main_bm_inode, start + len - 1);
	last_bit = osb->bitmap_cpg;

	for (group = first_group; group <= last_group;) {
		if (first_bit + len >= osb->bitmap_cpg)
			last_bit = osb->bitmap_cpg;
		else
			last_bit = first_bit + len;

		ret = ocfs2_read_group_descriptor(main_bm_inode,
						  main_bm, group,
						  &gd_bh);
		if (ret < 0) {
			mlog_errno(ret);
			break;
		}

		gd = (struct ocfs2_group_desc *)gd_bh->b_data;
		cnt = ocfs2_trim_group(sb, gd, first_bit, last_bit, minlen);
		brelse(gd_bh);
		gd_bh = NULL;
		if (cnt < 0) {
			ret = cnt;
			mlog_errno(ret);
			break;
		}

		trimmed += cnt;
		len -= osb->bitmap_cpg - first_bit;
		first_bit = 0;
		if (group == osb->first_cluster_group_blkno)
			group = ocfs2_clusters_to_blocks(sb, osb->bitmap_cpg);
		else
			group += ocfs2_clusters_to_blocks(sb, osb->bitmap_cpg);
	}
	range->len = trimmed * sb->s_blocksize;
out_unlock:
	ocfs2_inode_unlock(main_bm_inode, 0);
	brelse(main_bm_bh);
out_mutex:
	mutex_unlock(&main_bm_inode->i_mutex);
	iput(main_bm_inode);
out:
	return ret;
}