fs/ocfs2/xattr.c

/* -*- mode: c; c-basic-offset: 8; -*-
 * vim: noexpandtab sw=8 ts=8 sts=0:
 *
 * xattr.c
 *
 * Copyright (C) 2008 Oracle.  All rights reserved.
 *
 * CREDITS:
 * Lots of code in this file is taken from ext3.
 *
 * 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/capability.h>
#include <linux/fs.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/highmem.h>
#include <linux/pagemap.h>
#include <linux/uio.h>
#include <linux/sched.h>
#include <linux/splice.h>
#include <linux/mount.h>
#include <linux/writeback.h>
#include <linux/falloc.h>
#include <linux/sort.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/string.h>

#define MLOG_MASK_PREFIX ML_XATTR
#include <cluster/masklog.h>

#include "ocfs2.h"
#include "alloc.h"
#include "dlmglue.h"
#include "file.h"
#include "symlink.h"
#include "sysfile.h"
#include "inode.h"
#include "journal.h"
#include "ocfs2_fs.h"
#include "suballoc.h"
#include "uptodate.h"
#include "buffer_head_io.h"
#include "super.h"
#include "xattr.h"


struct ocfs2_xattr_def_value_root {
	struct ocfs2_xattr_value_root	xv;
	struct ocfs2_extent_rec		er;
};

struct ocfs2_xattr_bucket {
	struct buffer_head *bhs[OCFS2_XATTR_MAX_BLOCKS_PER_BUCKET];
	struct ocfs2_xattr_header *xh;
};

#define OCFS2_XATTR_ROOT_SIZE	(sizeof(struct ocfs2_xattr_def_value_root))
#define OCFS2_XATTR_INLINE_SIZE	80

static struct ocfs2_xattr_def_value_root def_xv = {
	.xv.xr_list.l_count = cpu_to_le16(1),
};

struct xattr_handler *ocfs2_xattr_handlers[] = {
	&ocfs2_xattr_user_handler,
	&ocfs2_xattr_trusted_handler,
	NULL
};

static struct xattr_handler *ocfs2_xattr_handler_map[] = {
	[OCFS2_XATTR_INDEX_USER]	= &ocfs2_xattr_user_handler,
	[OCFS2_XATTR_INDEX_TRUSTED]	= &ocfs2_xattr_trusted_handler,
};

struct ocfs2_xattr_info {
	int name_index;
	const char *name;
	const void *value;
	size_t value_len;
};

struct ocfs2_xattr_search {
	struct buffer_head *inode_bh;
	/*
	 * xattr_bh point to the block buffer head which has extended attribute
	 * when extended attribute in inode, xattr_bh is equal to inode_bh.
	 */
	struct buffer_head *xattr_bh;
	struct ocfs2_xattr_header *header;
	struct ocfs2_xattr_bucket bucket;
	void *base;
	void *end;
	struct ocfs2_xattr_entry *here;
	int not_found;
};

static int ocfs2_xattr_bucket_get_name_value(struct inode *inode,
					     struct ocfs2_xattr_header *xh,
					     int index,
					     int *block_off,
					     int *new_offset);

static int ocfs2_xattr_index_block_find(struct inode *inode,
					struct buffer_head *root_bh,
					int name_index,
					const char *name,
					struct ocfs2_xattr_search *xs);

static int ocfs2_xattr_tree_list_index_block(struct inode *inode,
					struct ocfs2_xattr_tree_root *xt,
					char *buffer,
					size_t buffer_size);

static int ocfs2_xattr_create_index_block(struct inode *inode,
					  struct ocfs2_xattr_search *xs);

static int ocfs2_xattr_set_entry_index_block(struct inode *inode,
					     struct ocfs2_xattr_info *xi,
					     struct ocfs2_xattr_search *xs);

static int ocfs2_delete_xattr_index_block(struct inode *inode,
					  struct buffer_head *xb_bh);

static inline const char *ocfs2_xattr_prefix(int name_index)
{
	struct xattr_handler *handler = NULL;

	if (name_index > 0 && name_index < OCFS2_XATTR_MAX)
		handler = ocfs2_xattr_handler_map[name_index];

	return handler ? handler->prefix : NULL;
}

static u32 ocfs2_xattr_name_hash(struct inode *inode,
				 const char *name,
				 int name_len)
{
	/* Get hash value of uuid from super block */
	u32 hash = OCFS2_SB(inode->i_sb)->uuid_hash;
	int i;

	/* hash extended attribute name */
	for (i = 0; i < name_len; i++) {
		hash = (hash << OCFS2_HASH_SHIFT) ^
		       (hash >> (8*sizeof(hash) - OCFS2_HASH_SHIFT)) ^
		       *name++;
	}

	return hash;
}

/*
 * ocfs2_xattr_hash_entry()
 *
 * Compute the hash of an extended attribute.
 */
static void ocfs2_xattr_hash_entry(struct inode *inode,
				   struct ocfs2_xattr_header *header,
				   struct ocfs2_xattr_entry *entry)
{
	u32 hash = 0;
	char *name = (char *)header + le16_to_cpu(entry->xe_name_offset);

	hash = ocfs2_xattr_name_hash(inode, name, entry->xe_name_len);
	entry->xe_name_hash = cpu_to_le32(hash);

	return;
}

static int ocfs2_xattr_extend_allocation(struct inode *inode,
					 u32 clusters_to_add,
					 struct buffer_head *xattr_bh,
					 struct ocfs2_xattr_value_root *xv)
{
	int status = 0;
	int restart_func = 0;
	int credits = 0;
	handle_t *handle = NULL;
	struct ocfs2_alloc_context *data_ac = NULL;
	struct ocfs2_alloc_context *meta_ac = NULL;
	enum ocfs2_alloc_restarted why;
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
	u32 prev_clusters, logical_start = le32_to_cpu(xv->xr_clusters);
	struct ocfs2_extent_tree et;

	mlog(0, "(clusters_to_add for xattr= %u)\n", clusters_to_add);

	ocfs2_init_xattr_value_extent_tree(&et, inode, xattr_bh, xv);

restart_all:

	status = ocfs2_lock_allocators(inode, &et, clusters_to_add, 0,
				       &data_ac, &meta_ac);
	if (status) {
		mlog_errno(status);
		goto leave;
	}

	credits = ocfs2_calc_extend_credits(osb->sb, et.et_root_el,
					    clusters_to_add);
	handle = ocfs2_start_trans(osb, credits);
	if (IS_ERR(handle)) {
		status = PTR_ERR(handle);
		handle = NULL;
		mlog_errno(status);
		goto leave;
	}

restarted_transaction:
	status = ocfs2_journal_access(handle, inode, xattr_bh,
				      OCFS2_JOURNAL_ACCESS_WRITE);
	if (status < 0) {
		mlog_errno(status);
		goto leave;
	}

	prev_clusters = le32_to_cpu(xv->xr_clusters);
	status = ocfs2_add_clusters_in_btree(osb,
					     inode,
					     &logical_start,
					     clusters_to_add,
					     0,
					     &et,
					     handle,
					     data_ac,
					     meta_ac,
					     &why);
	if ((status < 0) && (status != -EAGAIN)) {
		if (status != -ENOSPC)
			mlog_errno(status);
		goto leave;
	}

	status = ocfs2_journal_dirty(handle, xattr_bh);
	if (status < 0) {
		mlog_errno(status);
		goto leave;
	}

	clusters_to_add -= le32_to_cpu(xv->xr_clusters) - prev_clusters;

	if (why != RESTART_NONE && clusters_to_add) {
		if (why == RESTART_META) {
			mlog(0, "restarting function.\n");
			restart_func = 1;
		} else {
			BUG_ON(why != RESTART_TRANS);

			mlog(0, "restarting transaction.\n");
			/* TODO: This can be more intelligent. */
			credits = ocfs2_calc_extend_credits(osb->sb,
							    et.et_root_el,
							    clusters_to_add);
			status = ocfs2_extend_trans(handle, credits);
			if (status < 0) {
				/* handle still has to be committed at
				 * this point. */
				status = -ENOMEM;
				mlog_errno(status);
				goto leave;
			}
			goto restarted_transaction;
		}
	}

leave:
	if (handle) {
		ocfs2_commit_trans(osb, handle);
		handle = NULL;
	}
	if (data_ac) {
		ocfs2_free_alloc_context(data_ac);
		data_ac = NULL;
	}
	if (meta_ac) {
		ocfs2_free_alloc_context(meta_ac);
		meta_ac = NULL;
	}
	if ((!status) && restart_func) {
		restart_func = 0;
		goto restart_all;
	}

	return status;
}

static int __ocfs2_remove_xattr_range(struct inode *inode,
				      struct buffer_head *root_bh,
				      struct ocfs2_xattr_value_root *xv,
				      u32 cpos, u32 phys_cpos, u32 len,
				      struct ocfs2_cached_dealloc_ctxt *dealloc)
{
	int ret;
	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_extent_tree et;

	ocfs2_init_xattr_value_extent_tree(&et, inode, root_bh, xv);

	ret = ocfs2_lock_allocators(inode, &et, 0, 1, NULL, &meta_ac);
	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);
	if (IS_ERR(handle)) {
		ret = PTR_ERR(handle);
		mlog_errno(ret);
		goto out;
	}

	ret = ocfs2_journal_access(handle, inode, root_bh,
				   OCFS2_JOURNAL_ACCESS_WRITE);
	if (ret) {
		mlog_errno(ret);
		goto out_commit;
	}

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

	le32_add_cpu(&xv->xr_clusters, -len);

	ret = ocfs2_journal_dirty(handle, root_bh);
	if (ret) {
		mlog_errno(ret);
		goto out_commit;
	}

	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);

	return ret;
}

static int ocfs2_xattr_shrink_size(struct inode *inode,
				   u32 old_clusters,
				   u32 new_clusters,
				   struct buffer_head *root_bh,
				   struct ocfs2_xattr_value_root *xv)
{
	int ret = 0;
	u32 trunc_len, cpos, phys_cpos, alloc_size;
	u64 block;
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
	struct ocfs2_cached_dealloc_ctxt dealloc;

	ocfs2_init_dealloc_ctxt(&dealloc);

	if (old_clusters <= new_clusters)
		return 0;

	cpos = new_clusters;
	trunc_len = old_clusters - new_clusters;
	while (trunc_len) {
		ret = ocfs2_xattr_get_clusters(inode, cpos, &phys_cpos,
					       &alloc_size, &xv->xr_list);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		if (alloc_size > trunc_len)
			alloc_size = trunc_len;

		ret = __ocfs2_remove_xattr_range(inode, root_bh, xv, cpos,
						 phys_cpos, alloc_size,
						 &dealloc);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		block = ocfs2_clusters_to_blocks(inode->i_sb, phys_cpos);
		ocfs2_remove_xattr_clusters_from_cache(inode, block,
						       alloc_size);
		cpos += alloc_size;
		trunc_len -= alloc_size;
	}

out:
	ocfs2_schedule_truncate_log_flush(osb, 1);
	ocfs2_run_deallocs(osb, &dealloc);

	return ret;
}

static int ocfs2_xattr_value_truncate(struct inode *inode,
				      struct buffer_head *root_bh,
				      struct ocfs2_xattr_value_root *xv,
				      int len)
{
	int ret;
	u32 new_clusters = ocfs2_clusters_for_bytes(inode->i_sb, len);
	u32 old_clusters = le32_to_cpu(xv->xr_clusters);

	if (new_clusters == old_clusters)
		return 0;

	if (new_clusters > old_clusters)
		ret = ocfs2_xattr_extend_allocation(inode,
						    new_clusters - old_clusters,
						    root_bh, xv);
	else
		ret = ocfs2_xattr_shrink_size(inode,
					      old_clusters, new_clusters,
					      root_bh, xv);

	return ret;
}

static int ocfs2_xattr_list_entry(char *buffer, size_t size,
				  size_t *result, const char *prefix,
				  const char *name, int name_len)
{
	char *p = buffer + *result;
	int prefix_len = strlen(prefix);
	int total_len = prefix_len + name_len + 1;

	*result += total_len;

	/* we are just looking for how big our buffer needs to be */
	if (!size)
		return 0;

	if (*result > size)
		return -ERANGE;

	memcpy(p, prefix, prefix_len);
	memcpy(p + prefix_len, name, name_len);
	p[prefix_len + name_len] = '\0';

	return 0;
}

static int ocfs2_xattr_list_entries(struct inode *inode,
				    struct ocfs2_xattr_header *header,
				    char *buffer, size_t buffer_size)
{
	size_t result = 0;
	int i, type, ret;
	const char *prefix, *name;

	for (i = 0 ; i < le16_to_cpu(header->xh_count); i++) {
		struct ocfs2_xattr_entry *entry = &header->xh_entries[i];
		type = ocfs2_xattr_get_type(entry);
		prefix = ocfs2_xattr_prefix(type);

		if (prefix) {
			name = (const char *)header +
				le16_to_cpu(entry->xe_name_offset);

			ret = ocfs2_xattr_list_entry(buffer, buffer_size,
						     &result, prefix, name,
						     entry->xe_name_len);
			if (ret)
				return ret;
		}
	}

	return result;
}

static int ocfs2_xattr_ibody_list(struct inode *inode,
				  struct ocfs2_dinode *di,
				  char *buffer,
				  size_t buffer_size)
{
	struct ocfs2_xattr_header *header = NULL;
	struct ocfs2_inode_info *oi = OCFS2_I(inode);
	int ret = 0;

	if (!(oi->ip_dyn_features & OCFS2_INLINE_XATTR_FL))
		return ret;

	header = (struct ocfs2_xattr_header *)
		 ((void *)di + inode->i_sb->s_blocksize -
		 le16_to_cpu(di->i_xattr_inline_size));

	ret = ocfs2_xattr_list_entries(inode, header, buffer, buffer_size);

	return ret;
}

static int ocfs2_xattr_block_list(struct inode *inode,
				  struct ocfs2_dinode *di,
				  char *buffer,
				  size_t buffer_size)
{
	struct buffer_head *blk_bh = NULL;
	struct ocfs2_xattr_block *xb;
	int ret = 0;

	if (!di->i_xattr_loc)
		return ret;

	ret = ocfs2_read_block(OCFS2_SB(inode->i_sb),
			       le64_to_cpu(di->i_xattr_loc),
			       &blk_bh, OCFS2_BH_CACHED, inode);
	if (ret < 0) {
		mlog_errno(ret);
		return ret;
	}
	/*Verify the signature of xattr block*/
	if (memcmp((void *)blk_bh->b_data, OCFS2_XATTR_BLOCK_SIGNATURE,
		   strlen(OCFS2_XATTR_BLOCK_SIGNATURE))) {
		ret = -EFAULT;
		goto cleanup;
	}

	xb = (struct ocfs2_xattr_block *)blk_bh->b_data;

	if (!(le16_to_cpu(xb->xb_flags) & OCFS2_XATTR_INDEXED)) {
		struct ocfs2_xattr_header *header = &xb->xb_attrs.xb_header;
		ret = ocfs2_xattr_list_entries(inode, header,
					       buffer, buffer_size);
	} else {
		struct ocfs2_xattr_tree_root *xt = &xb->xb_attrs.xb_root;
		ret = ocfs2_xattr_tree_list_index_block(inode, xt,
						   buffer, buffer_size);
	}
cleanup:
	brelse(blk_bh);

	return ret;
}

ssize_t ocfs2_listxattr(struct dentry *dentry,
			char *buffer,
			size_t size)
{
	int ret = 0, i_ret = 0, b_ret = 0;
	struct buffer_head *di_bh = NULL;
	struct ocfs2_dinode *di = NULL;
	struct ocfs2_inode_info *oi = OCFS2_I(dentry->d_inode);

	if (!ocfs2_supports_xattr(OCFS2_SB(dentry->d_sb)))
		return -EOPNOTSUPP;

	if (!(oi->ip_dyn_features & OCFS2_HAS_XATTR_FL))
		return ret;

	ret = ocfs2_inode_lock(dentry->d_inode, &di_bh, 0);
	if (ret < 0) {
		mlog_errno(ret);
		return ret;
	}

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

	down_read(&oi->ip_xattr_sem);
	i_ret = ocfs2_xattr_ibody_list(dentry->d_inode, di, buffer, size);
	if (i_ret < 0)
		b_ret = 0;
	else {
		if (buffer) {
			buffer += i_ret;
			size -= i_ret;
		}
		b_ret = ocfs2_xattr_block_list(dentry->d_inode, di,
					       buffer, size);
		if (b_ret < 0)
			i_ret = 0;
	}
	up_read(&oi->ip_xattr_sem);
	ocfs2_inode_unlock(dentry->d_inode, 0);

	brelse(di_bh);

	return i_ret + b_ret;
}

static int ocfs2_xattr_find_entry(int name_index,
				  const char *name,
				  struct ocfs2_xattr_search *xs)
{
	struct ocfs2_xattr_entry *entry;
	size_t name_len;
	int i, cmp = 1;

	if (name == NULL)
		return -EINVAL;

	name_len = strlen(name);
	entry = xs->here;
	for (i = 0; i < le16_to_cpu(xs->header->xh_count); i++) {
		cmp = name_index - ocfs2_xattr_get_type(entry);
		if (!cmp)
			cmp = name_len - entry->xe_name_len;
		if (!cmp)
			cmp = memcmp(name, (xs->base +
				     le16_to_cpu(entry->xe_name_offset)),
				     name_len);
		if (cmp == 0)
			break;
		entry += 1;
	}
	xs->here = entry;

	return cmp ? -ENODATA : 0;
}

static int ocfs2_xattr_get_value_outside(struct inode *inode,
					 struct ocfs2_xattr_value_root *xv,
					 void *buffer,
					 size_t len)
{
	u32 cpos, p_cluster, num_clusters, bpc, clusters;
	u64 blkno;
	int i, ret = 0;
	size_t cplen, blocksize;
	struct buffer_head *bh = NULL;
	struct ocfs2_extent_list *el;

	el = &xv->xr_list;
	clusters = le32_to_cpu(xv->xr_clusters);
	bpc = ocfs2_clusters_to_blocks(inode->i_sb, 1);
	blocksize = inode->i_sb->s_blocksize;

	cpos = 0;
	while (cpos < clusters) {
		ret = ocfs2_xattr_get_clusters(inode, cpos, &p_cluster,
					       &num_clusters, el);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		blkno = ocfs2_clusters_to_blocks(inode->i_sb, p_cluster);
		/* Copy ocfs2_xattr_value */
		for (i = 0; i < num_clusters * bpc; i++, blkno++) {
			ret = ocfs2_read_block(OCFS2_SB(inode->i_sb), blkno,
					       &bh, OCFS2_BH_CACHED, inode);
			if (ret) {
				mlog_errno(ret);
				goto out;
			}

			cplen = len >= blocksize ? blocksize : len;
			memcpy(buffer, bh->b_data, cplen);
			len -= cplen;
			buffer += cplen;

			brelse(bh);
			bh = NULL;
			if (len == 0)
				break;
		}
		cpos += num_clusters;
	}
out:
	return ret;
}

static int ocfs2_xattr_ibody_get(struct inode *inode,
				 int name_index,
				 const char *name,
				 void *buffer,
				 size_t buffer_size,
				 struct ocfs2_xattr_search *xs)
{
	struct ocfs2_inode_info *oi = OCFS2_I(inode);
	struct ocfs2_dinode *di = (struct ocfs2_dinode *)xs->inode_bh->b_data;
	struct ocfs2_xattr_value_root *xv;
	size_t size;
	int ret = 0;

	if (!(oi->ip_dyn_features & OCFS2_INLINE_XATTR_FL))
		return -ENODATA;

	xs->end = (void *)di + inode->i_sb->s_blocksize;
	xs->header = (struct ocfs2_xattr_header *)
			(xs->end - le16_to_cpu(di->i_xattr_inline_size));
	xs->base = (void *)xs->header;
	xs->here = xs->header->xh_entries;

	ret = ocfs2_xattr_find_entry(name_index, name, xs);
	if (ret)
		return ret;
	size = le64_to_cpu(xs->here->xe_value_size);
	if (buffer) {
		if (size > buffer_size)
			return -ERANGE;
		if (ocfs2_xattr_is_local(xs->here)) {
			memcpy(buffer, (void *)xs->base +
			       le16_to_cpu(xs->here->xe_name_offset) +
			       OCFS2_XATTR_SIZE(xs->here->xe_name_len), size);
		} else {
			xv = (struct ocfs2_xattr_value_root *)
				(xs->base + le16_to_cpu(
				 xs->here->xe_name_offset) +
				OCFS2_XATTR_SIZE(xs->here->xe_name_len));
			ret = ocfs2_xattr_get_value_outside(inode, xv,
							    buffer, size);
			if (ret < 0) {
				mlog_errno(ret);
				return ret;
			}
		}
	}

	return size;
}

static int ocfs2_xattr_block_get(struct inode *inode,
				 int name_index,
				 const char *name,
				 void *buffer,
				 size_t buffer_size,
				 struct ocfs2_xattr_search *xs)
{
	struct ocfs2_dinode *di = (struct ocfs2_dinode *)xs->inode_bh->b_data;
	struct buffer_head *blk_bh = NULL;
	struct ocfs2_xattr_block *xb;
	struct ocfs2_xattr_value_root *xv;
	size_t size;
	int ret = -ENODATA, name_offset, name_len, block_off, i;

	if (!di->i_xattr_loc)
		return ret;

	memset(&xs->bucket, 0, sizeof(xs->bucket));

	ret = ocfs2_read_block(OCFS2_SB(inode->i_sb),
			       le64_to_cpu(di->i_xattr_loc),
			       &blk_bh, OCFS2_BH_CACHED, inode);
	if (ret < 0) {
		mlog_errno(ret);
		return ret;
	}
	/*Verify the signature of xattr block*/
	if (memcmp((void *)blk_bh->b_data, OCFS2_XATTR_BLOCK_SIGNATURE,
		   strlen(OCFS2_XATTR_BLOCK_SIGNATURE))) {
		ret = -EFAULT;
		goto cleanup;
	}

	xs->xattr_bh = blk_bh;
	xb = (struct ocfs2_xattr_block *)blk_bh->b_data;

	if (!(le16_to_cpu(xb->xb_flags) & OCFS2_XATTR_INDEXED)) {
		xs->header = &xb->xb_attrs.xb_header;
		xs->base = (void *)xs->header;
		xs->end = (void *)(blk_bh->b_data) + blk_bh->b_size;
		xs->here = xs->header->xh_entries;

		ret = ocfs2_xattr_find_entry(name_index, name, xs);
	} else
		ret = ocfs2_xattr_index_block_find(inode, blk_bh,
						   name_index,
						   name, xs);

	if (ret)
		goto cleanup;
	size = le64_to_cpu(xs->here->xe_value_size);
	if (buffer) {
		ret = -ERANGE;
		if (size > buffer_size)
			goto cleanup;

		name_offset = le16_to_cpu(xs->here->xe_name_offset);
		name_len = OCFS2_XATTR_SIZE(xs->here->xe_name_len);
		i = xs->here - xs->header->xh_entries;

		if (le16_to_cpu(xb->xb_flags) & OCFS2_XATTR_INDEXED) {
			ret = ocfs2_xattr_bucket_get_name_value(inode,
								xs->bucket.xh,
								i,
								&block_off,
								&name_offset);
			xs->base = xs->bucket.bhs[block_off]->b_data;
		}
		if (ocfs2_xattr_is_local(xs->here)) {
			memcpy(buffer, (void *)xs->base +
			       name_offset + name_len, size);
		} else {
			xv = (struct ocfs2_xattr_value_root *)
				(xs->base + name_offset + name_len);
			ret = ocfs2_xattr_get_value_outside(inode, xv,
							    buffer, size);
			if (ret < 0) {
				mlog_errno(ret);
				goto cleanup;
			}
		}
	}
	ret = size;
cleanup:
	for (i = 0; i < OCFS2_XATTR_MAX_BLOCKS_PER_BUCKET; i++)
		brelse(xs->bucket.bhs[i]);
	memset(&xs->bucket, 0, sizeof(xs->bucket));

	brelse(blk_bh);
	return ret;
}

/* ocfs2_xattr_get()
 *
 * Copy an extended attribute into the buffer provided.
 * Buffer is NULL to compute the size of buffer required.
 */
int ocfs2_xattr_get(struct inode *inode,
		    int name_index,
		    const char *name,
		    void *buffer,
		    size_t buffer_size)
{
	int ret;
	struct ocfs2_dinode *di = NULL;
	struct buffer_head *di_bh = NULL;
	struct ocfs2_inode_info *oi = OCFS2_I(inode);
	struct ocfs2_xattr_search xis = {
		.not_found = -ENODATA,
	};
	struct ocfs2_xattr_search xbs = {
		.not_found = -ENODATA,
	};

	if (!ocfs2_supports_xattr(OCFS2_SB(inode->i_sb)))
		return -EOPNOTSUPP;

	if (!(oi->ip_dyn_features & OCFS2_HAS_XATTR_FL))
		ret = -ENODATA;

	ret = ocfs2_inode_lock(inode, &di_bh, 0);
	if (ret < 0) {
		mlog_errno(ret);
		return ret;
	}
	xis.inode_bh = xbs.inode_bh = di_bh;
	di = (struct ocfs2_dinode *)di_bh->b_data;

	down_read(&oi->ip_xattr_sem);
	ret = ocfs2_xattr_ibody_get(inode, name_index, name, buffer,
				    buffer_size, &xis);
	if (ret == -ENODATA)
		ret = ocfs2_xattr_block_get(inode, name_index, name, buffer,
					    buffer_size, &xbs);
	up_read(&oi->ip_xattr_sem);
	ocfs2_inode_unlock(inode, 0);

	brelse(di_bh);

	return ret;
}

static int __ocfs2_xattr_set_value_outside(struct inode *inode,
					   struct ocfs2_xattr_value_root *xv,
					   const void *value,
					   int value_len)
{
	int ret = 0, i, cp_len, credits;
	u16 blocksize = inode->i_sb->s_blocksize;
	u32 p_cluster, num_clusters;
	u32 cpos = 0, bpc = ocfs2_clusters_to_blocks(inode->i_sb, 1);
	u32 clusters = ocfs2_clusters_for_bytes(inode->i_sb, value_len);
	u64 blkno;
	struct buffer_head *bh = NULL;
	handle_t *handle;

	BUG_ON(clusters > le32_to_cpu(xv->xr_clusters));

	credits = clusters * bpc;
	handle = ocfs2_start_trans(OCFS2_SB(inode->i_sb), credits);
	if (IS_ERR(handle)) {
		ret = PTR_ERR(handle);
		mlog_errno(ret);
		goto out;
	}

	while (cpos < clusters) {
		ret = ocfs2_xattr_get_clusters(inode, cpos, &p_cluster,
					       &num_clusters, &xv->xr_list);
		if (ret) {
			mlog_errno(ret);
			goto out_commit;
		}

		blkno = ocfs2_clusters_to_blocks(inode->i_sb, p_cluster);

		for (i = 0; i < num_clusters * bpc; i++, blkno++) {
			ret = ocfs2_read_block(OCFS2_SB(inode->i_sb), blkno,
					       &bh, OCFS2_BH_CACHED, inode);
			if (ret) {
				mlog_errno(ret);
				goto out_commit;
			}

			ret = ocfs2_journal_access(handle,
						   inode,
						   bh,
						   OCFS2_JOURNAL_ACCESS_WRITE);
			if (ret < 0) {
				mlog_errno(ret);
				goto out_commit;
			}

			cp_len = value_len > blocksize ? blocksize : value_len;
			memcpy(bh->b_data, value, cp_len);
			value_len -= cp_len;
			value += cp_len;
			if (cp_len < blocksize)
				memset(bh->b_data + cp_len, 0,
				       blocksize - cp_len);

			ret = ocfs2_journal_dirty(handle, bh);
			if (ret < 0) {
				mlog_errno(ret);
				goto out_commit;
			}
			brelse(bh);
			bh = NULL;

			/*
			 * XXX: do we need to empty all the following
			 * blocks in this cluster?
			 */
			if (!value_len)
				break;
		}
		cpos += num_clusters;
	}
out_commit:
	ocfs2_commit_trans(OCFS2_SB(inode->i_sb), handle);
out:
	brelse(bh);

	return ret;
}

static int ocfs2_xattr_cleanup(struct inode *inode,
			       struct ocfs2_xattr_info *xi,
			       struct ocfs2_xattr_search *xs,
			       size_t offs)
{
	handle_t *handle = NULL;
	int ret = 0;
	size_t name_len = strlen(xi->name);
	void *val = xs->base + offs;
	size_t size = OCFS2_XATTR_SIZE(name_len) + OCFS2_XATTR_ROOT_SIZE;

	handle = ocfs2_start_trans((OCFS2_SB(inode->i_sb)),
				   OCFS2_XATTR_BLOCK_UPDATE_CREDITS);
	if (IS_ERR(handle)) {
		ret = PTR_ERR(handle);
		mlog_errno(ret);
		goto out;
	}
	ret = ocfs2_journal_access(handle, inode, xs->xattr_bh,
				   OCFS2_JOURNAL_ACCESS_WRITE);
	if (ret) {
		mlog_errno(ret);
		goto out_commit;
	}
	/* Decrease xattr count */
	le16_add_cpu(&xs->header->xh_count, -1);
	/* Remove the xattr entry and tree root which has already be set*/
	memset((void *)xs->here, 0, sizeof(struct ocfs2_xattr_entry));
	memset(val, 0, size);

	ret = ocfs2_journal_dirty(handle, xs->xattr_bh);
	if (ret < 0)
		mlog_errno(ret);
out_commit:
	ocfs2_commit_trans(OCFS2_SB(inode->i_sb), handle);
out:
	return ret;
}

static int ocfs2_xattr_update_entry(struct inode *inode,
				    struct ocfs2_xattr_info *xi,
				    struct ocfs2_xattr_search *xs,
				    size_t offs)
{
	handle_t *handle = NULL;
	int ret = 0;

	handle = ocfs2_start_trans((OCFS2_SB(inode->i_sb)),
				   OCFS2_XATTR_BLOCK_UPDATE_CREDITS);
	if (IS_ERR(handle)) {
		ret = PTR_ERR(handle);
		mlog_errno(ret);
		goto out;
	}
	ret = ocfs2_journal_access(handle, inode, xs->xattr_bh,
				   OCFS2_JOURNAL_ACCESS_WRITE);
	if (ret) {
		mlog_errno(ret);
		goto out_commit;
	}

	xs->here->xe_name_offset = cpu_to_le16(offs);
	xs->here->xe_value_size = cpu_to_le64(xi->value_len);
	if (xi->value_len <= OCFS2_XATTR_INLINE_SIZE)
		ocfs2_xattr_set_local(xs->here, 1);
	else
		ocfs2_xattr_set_local(xs->here, 0);
	ocfs2_xattr_hash_entry(inode, xs->header, xs->here);

	ret = ocfs2_journal_dirty(handle, xs->xattr_bh);
	if (ret < 0)
		mlog_errno(ret);
out_commit:
	ocfs2_commit_trans(OCFS2_SB(inode->i_sb), handle);
out:
	return ret;
}

/*
 * ocfs2_xattr_set_value_outside()
 *
 * Set large size value in B tree.
 */
static int ocfs2_xattr_set_value_outside(struct inode *inode,
					 struct ocfs2_xattr_info *xi,
					 struct ocfs2_xattr_search *xs,
					 size_t offs)
{
	size_t name_len = strlen(xi->name);
	void *val = xs->base + offs;
	struct ocfs2_xattr_value_root *xv = NULL;
	size_t size = OCFS2_XATTR_SIZE(name_len) + OCFS2_XATTR_ROOT_SIZE;
	int ret = 0;

	memset(val, 0, size);
	memcpy(val, xi->name, name_len);
	xv = (struct ocfs2_xattr_value_root *)
		(val + OCFS2_XATTR_SIZE(name_len));
	xv->xr_clusters = 0;
	xv->xr_last_eb_blk = 0;
	xv->xr_list.l_tree_depth = 0;
	xv->xr_list.l_count = cpu_to_le16(1);
	xv->xr_list.l_next_free_rec = 0;

	ret = ocfs2_xattr_value_truncate(inode, xs->xattr_bh, xv,
					 xi->value_len);
	if (ret < 0) {
		mlog_errno(ret);
		return ret;
	}
	ret = __ocfs2_xattr_set_value_outside(inode, xv, xi->value,
					      xi->value_len);
	if (ret < 0) {
		mlog_errno(ret);
		return ret;
	}
	ret = ocfs2_xattr_update_entry(inode, xi, xs, offs);
	if (ret < 0)
		mlog_errno(ret);

	return ret;
}

/*
 * ocfs2_xattr_set_entry_local()
 *
 * Set, replace or remove extended attribute in local.
 */
static void ocfs2_xattr_set_entry_local(struct inode *inode,
					struct ocfs2_xattr_info *xi,
					struct ocfs2_xattr_search *xs,
					struct ocfs2_xattr_entry *last,
					size_t min_offs)
{
	size_t name_len = strlen(xi->name);
	int i;

	if (xi->value && xs->not_found) {
		/* Insert the new xattr entry. */
		le16_add_cpu(&xs->header->xh_count, 1);
		ocfs2_xattr_set_type(last, xi->name_index);
		ocfs2_xattr_set_local(last, 1);
		last->xe_name_len = name_len;
	} else {
		void *first_val;
		void *val;
		size_t offs, size;

		first_val = xs->base + min_offs;
		offs = le16_to_cpu(xs->here->xe_name_offset);
		val = xs->base + offs;

		if (le64_to_cpu(xs->here->xe_value_size) >
		    OCFS2_XATTR_INLINE_SIZE)
			size = OCFS2_XATTR_SIZE(name_len) +
				OCFS2_XATTR_ROOT_SIZE;
		else
			size = OCFS2_XATTR_SIZE(name_len) +
			OCFS2_XATTR_SIZE(le64_to_cpu(xs->here->xe_value_size));

		if (xi->value && size == OCFS2_XATTR_SIZE(name_len) +
				OCFS2_XATTR_SIZE(xi->value_len)) {
			/* The old and the new value have the
			   same size. Just replace the value. */
			ocfs2_xattr_set_local(xs->here, 1);
			xs->here->xe_value_size = cpu_to_le64(xi->value_len);
			/* Clear value bytes. */
			memset(val + OCFS2_XATTR_SIZE(name_len),
			       0,
			       OCFS2_XATTR_SIZE(xi->value_len));
			memcpy(val + OCFS2_XATTR_SIZE(name_len),
			       xi->value,
			       xi->value_len);
			return;
		}
		/* Remove the old name+value. */
		memmove(first_val + size, first_val, val - first_val);
		memset(first_val, 0, size);
		xs->here->xe_name_hash = 0;
		xs->here->xe_name_offset = 0;
		ocfs2_xattr_set_local(xs->here, 1);
		xs->here->xe_value_size = 0;

		min_offs += size;

		/* Adjust all value offsets. */
		last = xs->header->xh_entries;
		for (i = 0 ; i < le16_to_cpu(xs->header->xh_count); i++) {
			size_t o = le16_to_cpu(last->xe_name_offset);

			if (o < offs)
				last->xe_name_offset = cpu_to_le16(o + size);
			last += 1;
		}

		if (!xi->value) {
			/* Remove the old entry. */
			last -= 1;
			memmove(xs->here, xs->here + 1,
				(void *)last - (void *)xs->here);
			memset(last, 0, sizeof(struct ocfs2_xattr_entry));
			le16_add_cpu(&xs->header->xh_count, -1);
		}
	}
	if (xi->value) {
		/* Insert the new name+value. */
		size_t size = OCFS2_XATTR_SIZE(name_len) +
				OCFS2_XATTR_SIZE(xi->value_len);
		void *val = xs->base + min_offs - size;

		xs->here->xe_name_offset = cpu_to_le16(min_offs - size);
		memset(val, 0, size);
		memcpy(val, xi->name, name_len);
		memcpy(val + OCFS2_XATTR_SIZE(name_len),
		       xi->value,
		       xi->value_len);
		xs->here->xe_value_size = cpu_to_le64(xi->value_len);
		ocfs2_xattr_set_local(xs->here, 1);
		ocfs2_xattr_hash_entry(inode, xs->header, xs->here);
	}

	return;
}

/*
 * ocfs2_xattr_set_entry()
 *
 * Set extended attribute entry into inode or block.
 *
 * If extended attribute value size > OCFS2_XATTR_INLINE_SIZE,
 * We first insert tree root(ocfs2_xattr_value_root) with set_entry_local(),
 * then set value in B tree with set_value_outside().
 */
static int ocfs2_xattr_set_entry(struct inode *inode,
				 struct ocfs2_xattr_info *xi,
				 struct ocfs2_xattr_search *xs,
				 int flag)
{
	struct ocfs2_xattr_entry *last;
	struct ocfs2_inode_info *oi = OCFS2_I(inode);
	struct ocfs2_dinode *di = (struct ocfs2_dinode *)xs->inode_bh->b_data;
	size_t min_offs = xs->end - xs->base, name_len = strlen(xi->name);
	size_t size_l = 0;
	handle_t *handle = NULL;
	int free, i, ret;
	struct ocfs2_xattr_info xi_l = {
		.name_index = xi->name_index,
		.name = xi->name,
		.value = xi->value,
		.value_len = xi->value_len,
	};

	/* Compute min_offs, last and free space. */
	last = xs->header->xh_entries;

	for (i = 0 ; i < le16_to_cpu(xs->header->xh_count); i++) {
		size_t offs = le16_to_cpu(last->xe_name_offset);
		if (offs < min_offs)
			min_offs = offs;
		last += 1;
	}

	free = min_offs - ((void *)last - xs->base) - sizeof(__u32);
	if (free < 0)
		return -EFAULT;

	if (!xs->not_found) {
		size_t size = 0;
		if (ocfs2_xattr_is_local(xs->here))
			size = OCFS2_XATTR_SIZE(name_len) +
			OCFS2_XATTR_SIZE(le64_to_cpu(xs->here->xe_value_size));
		else
			size = OCFS2_XATTR_SIZE(name_len) +
				OCFS2_XATTR_ROOT_SIZE;
		free += (size + sizeof(struct ocfs2_xattr_entry));
	}
	/* Check free space in inode or block */
	if (xi->value && xi->value_len > OCFS2_XATTR_INLINE_SIZE) {
		if (free < sizeof(struct ocfs2_xattr_entry) +
			   OCFS2_XATTR_SIZE(name_len) +
			   OCFS2_XATTR_ROOT_SIZE) {
			ret = -ENOSPC;
			goto out;
		}
		size_l = OCFS2_XATTR_SIZE(name_len) + OCFS2_XATTR_ROOT_SIZE;
		xi_l.value = (void *)&def_xv;
		xi_l.value_len = OCFS2_XATTR_ROOT_SIZE;
	} else if (xi->value) {
		if (free < sizeof(struct ocfs2_xattr_entry) +
			   OCFS2_XATTR_SIZE(name_len) +
			   OCFS2_XATTR_SIZE(xi->value_len)) {
			ret = -ENOSPC;
			goto out;
		}
	}

	if (!xs->not_found) {
		/* For existing extended attribute */
		size_t size = OCFS2_XATTR_SIZE(name_len) +
			OCFS2_XATTR_SIZE(le64_to_cpu(xs->here->xe_value_size));
		size_t offs = le16_to_cpu(xs->here->xe_name_offset);
		void *val = xs->base + offs;

		if (ocfs2_xattr_is_local(xs->here) && size == size_l) {
			/* Replace existing local xattr with tree root */
			ret = ocfs2_xattr_set_value_outside(inode, xi, xs,
							    offs);
			if (ret < 0)
				mlog_errno(ret);
			goto out;
		} else if (!ocfs2_xattr_is_local(xs->here)) {
			/* For existing xattr which has value outside */
			struct ocfs2_xattr_value_root *xv = NULL;
			xv = (struct ocfs2_xattr_value_root *)(val +
				OCFS2_XATTR_SIZE(name_len));

			if (xi->value_len > OCFS2_XATTR_INLINE_SIZE) {
				/*
				 * If new value need set outside also,
				 * first truncate old value to new value,
				 * then set new value with set_value_outside().
				 */
				ret = ocfs2_xattr_value_truncate(inode,
								 xs->xattr_bh,
								 xv,
								 xi->value_len);
				if (ret < 0) {
					mlog_errno(ret);
					goto out;
				}

				ret = __ocfs2_xattr_set_value_outside(inode,
								xv,
								xi->value,
								xi->value_len);
				if (ret < 0) {
					mlog_errno(ret);
					goto out;
				}

				ret = ocfs2_xattr_update_entry(inode,
							       xi,
							       xs,
							       offs);
				if (ret < 0)
					mlog_errno(ret);
				goto out;
			} else {
				/*
				 * If new value need set in local,
				 * just trucate old value to zero.
				 */
				 ret = ocfs2_xattr_value_truncate(inode,
								 xs->xattr_bh,
								 xv,
								 0);
				if (ret < 0)
					mlog_errno(ret);
			}
		}
	}

	handle = ocfs2_start_trans((OCFS2_SB(inode->i_sb)),
				   OCFS2_INODE_UPDATE_CREDITS);
	if (IS_ERR(handle)) {
		ret = PTR_ERR(handle);
		mlog_errno(ret);
		goto out;
	}

	ret = ocfs2_journal_access(handle, inode, xs->inode_bh,
				   OCFS2_JOURNAL_ACCESS_WRITE);
	if (ret) {
		mlog_errno(ret);
		goto out_commit;
	}

	if (!(flag & OCFS2_INLINE_XATTR_FL)) {
		/* set extended attribute in external block. */
		ret = ocfs2_extend_trans(handle,
					 OCFS2_INODE_UPDATE_CREDITS +
					 OCFS2_XATTR_BLOCK_UPDATE_CREDITS);
		if (ret) {
			mlog_errno(ret);
			goto out_commit;
		}
		ret = ocfs2_journal_access(handle, inode, xs->xattr_bh,
					   OCFS2_JOURNAL_ACCESS_WRITE);
		if (ret) {
			mlog_errno(ret);
			goto out_commit;
		}
	}

	/*
	 * Set value in local, include set tree root in local.
	 * This is the first step for value size >INLINE_SIZE.
	 */
	ocfs2_xattr_set_entry_local(inode, &xi_l, xs, last, min_offs);

	if (!(flag & OCFS2_INLINE_XATTR_FL)) {
		ret = ocfs2_journal_dirty(handle, xs->xattr_bh);
		if (ret < 0) {
			mlog_errno(ret);
			goto out_commit;
		}
	}

	if (!(oi->ip_dyn_features & OCFS2_INLINE_XATTR_FL) &&
	    (flag & OCFS2_INLINE_XATTR_FL)) {
		struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
		unsigned int xattrsize = osb->s_xattr_inline_size;

		/*
		 * Adjust extent record count or inline data size
		 * to reserve space for extended attribute.
		 */
		if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
			struct ocfs2_inline_data *idata = &di->id2.i_data;
			le16_add_cpu(&idata->id_count, -xattrsize);
		} else if (!(ocfs2_inode_is_fast_symlink(inode))) {
			struct ocfs2_extent_list *el = &di->id2.i_list;
			le16_add_cpu(&el->l_count, -(xattrsize /
					sizeof(struct ocfs2_extent_rec)));
		}
		di->i_xattr_inline_size = cpu_to_le16(xattrsize);
	}
	/* Update xattr flag */
	spin_lock(&oi->ip_lock);
	oi->ip_dyn_features |= flag;
	di->i_dyn_features = cpu_to_le16(oi->ip_dyn_features);
	spin_unlock(&oi->ip_lock);
	/* Update inode ctime */
	inode->i_ctime = CURRENT_TIME;
	di->i_ctime = cpu_to_le64(inode->i_ctime.tv_sec);
	di->i_ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);

	ret = ocfs2_journal_dirty(handle, xs->inode_bh);
	if (ret < 0)
		mlog_errno(ret);

out_commit:
	ocfs2_commit_trans(OCFS2_SB(inode->i_sb), handle);

	if (!ret && xi->value_len > OCFS2_XATTR_INLINE_SIZE) {
		/*
		 * Set value outside in B tree.
		 * This is the second step for value size > INLINE_SIZE.
		 */
		size_t offs = le16_to_cpu(xs->here->xe_name_offset);
		ret = ocfs2_xattr_set_value_outside(inode, xi, xs, offs);
		if (ret < 0) {
			int ret2;

			mlog_errno(ret);
			/*
			 * If set value outside failed, we have to clean
			 * the junk tree root we have already set in local.
			 */
			ret2 = ocfs2_xattr_cleanup(inode, xi, xs, offs);
			if (ret2 < 0)
				mlog_errno(ret2);
		}
	}
out:
	return ret;

}

static int ocfs2_remove_value_outside(struct inode*inode,
				      struct buffer_head *bh,
				      struct ocfs2_xattr_header *header)
{
	int ret = 0, i;

	for (i = 0; i < le16_to_cpu(header->xh_count); i++) {
		struct ocfs2_xattr_entry *entry = &header->xh_entries[i];

		if (!ocfs2_xattr_is_local(entry)) {
			struct ocfs2_xattr_value_root *xv;
			void *val;

			val = (void *)header +
				le16_to_cpu(entry->xe_name_offset);
			xv = (struct ocfs2_xattr_value_root *)
				(val + OCFS2_XATTR_SIZE(entry->xe_name_len));
			ret = ocfs2_xattr_value_truncate(inode, bh, xv, 0);
			if (ret < 0) {
				mlog_errno(ret);
				return ret;
			}
		}
	}

	return ret;
}

static int ocfs2_xattr_ibody_remove(struct inode *inode,
				    struct buffer_head *di_bh)
{

	struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
	struct ocfs2_xattr_header *header;
	int ret;

	header = (struct ocfs2_xattr_header *)
		 ((void *)di + inode->i_sb->s_blocksize -
		 le16_to_cpu(di->i_xattr_inline_size));

	ret = ocfs2_remove_value_outside(inode, di_bh, header);

	return ret;
}

static int ocfs2_xattr_block_remove(struct inode *inode,
				    struct buffer_head *blk_bh)
{
	struct ocfs2_xattr_block *xb;
	int ret = 0;

	xb = (struct ocfs2_xattr_block *)blk_bh->b_data;
	if (!(le16_to_cpu(xb->xb_flags) & OCFS2_XATTR_INDEXED)) {
		struct ocfs2_xattr_header *header = &(xb->xb_attrs.xb_header);
		ret = ocfs2_remove_value_outside(inode, blk_bh, header);
	} else
		ret = ocfs2_delete_xattr_index_block(inode, blk_bh);

	return ret;
}

static int ocfs2_xattr_free_block(struct inode *inode,
				  u64 block)
{
	struct inode *xb_alloc_inode;
	struct buffer_head *xb_alloc_bh = NULL;
	struct buffer_head *blk_bh = NULL;
	struct ocfs2_xattr_block *xb;
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
	handle_t *handle;
	int ret = 0;
	u64 blk, bg_blkno;
	u16 bit;

	ret = ocfs2_read_block(osb, block, &blk_bh,
			       OCFS2_BH_CACHED, inode);
	if (ret < 0) {
		mlog_errno(ret);
		goto out;
	}

	/*Verify the signature of xattr block*/
	if (memcmp((void *)blk_bh->b_data, OCFS2_XATTR_BLOCK_SIGNATURE,
		   strlen(OCFS2_XATTR_BLOCK_SIGNATURE))) {
		ret = -EFAULT;
		goto out;
	}

	ret = ocfs2_xattr_block_remove(inode, blk_bh);
	if (ret < 0) {
		mlog_errno(ret);
		goto out;
	}

	xb = (struct ocfs2_xattr_block *)blk_bh->b_data;
	blk = le64_to_cpu(xb->xb_blkno);
	bit = le16_to_cpu(xb->xb_suballoc_bit);
	bg_blkno = ocfs2_which_suballoc_group(blk, bit);

	xb_alloc_inode = ocfs2_get_system_file_inode(osb,
				EXTENT_ALLOC_SYSTEM_INODE,
				le16_to_cpu(xb->xb_suballoc_slot));
	if (!xb_alloc_inode) {
		ret = -ENOMEM;
		mlog_errno(ret);
		goto out;
	}
	mutex_lock(&xb_alloc_inode->i_mutex);

	ret = ocfs2_inode_lock(xb_alloc_inode, &xb_alloc_bh, 1);
	if (ret < 0) {
		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;
	}

	ret = ocfs2_free_suballoc_bits(handle, xb_alloc_inode, xb_alloc_bh,
				       bit, bg_blkno, 1);
	if (ret < 0)
		mlog_errno(ret);

	ocfs2_commit_trans(osb, handle);
out_unlock:
	ocfs2_inode_unlock(xb_alloc_inode, 1);
	brelse(xb_alloc_bh);
out_mutex:
	mutex_unlock(&xb_alloc_inode->i_mutex);
	iput(xb_alloc_inode);
out:
	brelse(blk_bh);
	return ret;
}

/*
 * ocfs2_xattr_remove()
 *
 * Free extended attribute resources associated with this inode.
 */
int ocfs2_xattr_remove(struct inode *inode, struct buffer_head *di_bh)
{
	struct ocfs2_inode_info *oi = OCFS2_I(inode);
	struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
	handle_t *handle;
	int ret;

	if (!ocfs2_supports_xattr(OCFS2_SB(inode->i_sb)))
		return 0;

	if (!(oi->ip_dyn_features & OCFS2_HAS_XATTR_FL))
		return 0;

	if (oi->ip_dyn_features & OCFS2_INLINE_XATTR_FL) {
		ret = ocfs2_xattr_ibody_remove(inode, di_bh);
		if (ret < 0) {
			mlog_errno(ret);
			goto out;
		}
	}

	if (di->i_xattr_loc) {
		ret = ocfs2_xattr_free_block(inode,
					     le64_to_cpu(di->i_xattr_loc));
		if (ret < 0) {
			mlog_errno(ret);
			goto out;
		}
	}

	handle = ocfs2_start_trans((OCFS2_SB(inode->i_sb)),
				   OCFS2_INODE_UPDATE_CREDITS);
	if (IS_ERR(handle)) {
		ret = PTR_ERR(handle);
		mlog_errno(ret);
		goto out;
	}
	ret = ocfs2_journal_access(handle, inode, di_bh,
				   OCFS2_JOURNAL_ACCESS_WRITE);
	if (ret) {
		mlog_errno(ret);
		goto out_commit;
	}

	di->i_xattr_loc = 0;

	spin_lock(&oi->ip_lock);
	oi->ip_dyn_features &= ~(OCFS2_INLINE_XATTR_FL | OCFS2_HAS_XATTR_FL);
	di->i_dyn_features = cpu_to_le16(oi->ip_dyn_features);
	spin_unlock(&oi->ip_lock);

	ret = ocfs2_journal_dirty(handle, di_bh);
	if (ret < 0)
		mlog_errno(ret);
out_commit:
	ocfs2_commit_trans(OCFS2_SB(inode->i_sb), handle);
out:
	return ret;
}

static int ocfs2_xattr_has_space_inline(struct inode *inode,
					struct ocfs2_dinode *di)
{
	struct ocfs2_inode_info *oi = OCFS2_I(inode);
	unsigned int xattrsize = OCFS2_SB(inode->i_sb)->s_xattr_inline_size;
	int free;

	if (xattrsize < OCFS2_MIN_XATTR_INLINE_SIZE)
		return 0;

	if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
		struct ocfs2_inline_data *idata = &di->id2.i_data;
		free = le16_to_cpu(idata->id_count) - le64_to_cpu(di->i_size);
	} else if (ocfs2_inode_is_fast_symlink(inode)) {
		free = ocfs2_fast_symlink_chars(inode->i_sb) -
			le64_to_cpu(di->i_size);
	} else {
		struct ocfs2_extent_list *el = &di->id2.i_list;
		free = (le16_to_cpu(el->l_count) -
			le16_to_cpu(el->l_next_free_rec)) *
			sizeof(struct ocfs2_extent_rec);
	}
	if (free >= xattrsize)
		return 1;

	return 0;
}

/*
 * ocfs2_xattr_ibody_find()
 *
 * Find extended attribute in inode block and
 * fill search info into struct ocfs2_xattr_search.
 */
static int ocfs2_xattr_ibody_find(struct inode *inode,
				  int name_index,
				  const char *name,
				  struct ocfs2_xattr_search *xs)
{
	struct ocfs2_inode_info *oi = OCFS2_I(inode);
	struct ocfs2_dinode *di = (struct ocfs2_dinode *)xs->inode_bh->b_data;
	int ret;
	int has_space = 0;

	if (inode->i_sb->s_blocksize == OCFS2_MIN_BLOCKSIZE)
		return 0;

	if (!(oi->ip_dyn_features & OCFS2_INLINE_XATTR_FL)) {
		down_read(&oi->ip_alloc_sem);
		has_space = ocfs2_xattr_has_space_inline(inode, di);
		up_read(&oi->ip_alloc_sem);
		if (!has_space)
			return 0;
	}

	xs->xattr_bh = xs->inode_bh;
	xs->end = (void *)di + inode->i_sb->s_blocksize;
	if (oi->ip_dyn_features & OCFS2_INLINE_XATTR_FL)
		xs->header = (struct ocfs2_xattr_header *)
			(xs->end - le16_to_cpu(di->i_xattr_inline_size));
	else
		xs->header = (struct ocfs2_xattr_header *)
			(xs->end - OCFS2_SB(inode->i_sb)->s_xattr_inline_size);
	xs->base = (void *)xs->header;
	xs->here = xs->header->xh_entries;

	/* Find the named attribute. */
	if (oi->ip_dyn_features & OCFS2_INLINE_XATTR_FL) {
		ret = ocfs2_xattr_find_entry(name_index, name, xs);
		if (ret && ret != -ENODATA)
			return ret;
		xs->not_found = ret;
	}

	return 0;
}

/*
 * ocfs2_xattr_ibody_set()
 *
 * Set, replace or remove an extended attribute into inode block.
 *
 */
static int ocfs2_xattr_ibody_set(struct inode *inode,
				 struct ocfs2_xattr_info *xi,
				 struct ocfs2_xattr_search *xs)
{
	struct ocfs2_inode_info *oi = OCFS2_I(inode);
	struct ocfs2_dinode *di = (struct ocfs2_dinode *)xs->inode_bh->b_data;
	int ret;

	if (inode->i_sb->s_blocksize == OCFS2_MIN_BLOCKSIZE)
		return -ENOSPC;

	down_write(&oi->ip_alloc_sem);
	if (!(oi->ip_dyn_features & OCFS2_INLINE_XATTR_FL)) {
		if (!ocfs2_xattr_has_space_inline(inode, di)) {
			ret = -ENOSPC;
			goto out;
		}
	}

	ret = ocfs2_xattr_set_entry(inode, xi, xs,
				(OCFS2_INLINE_XATTR_FL | OCFS2_HAS_XATTR_FL));
out:
	up_write(&oi->ip_alloc_sem);

	return ret;
}

/*
 * ocfs2_xattr_block_find()
 *
 * Find extended attribute in external block and
 * fill search info into struct ocfs2_xattr_search.
 */
static int ocfs2_xattr_block_find(struct inode *inode,
				  int name_index,
				  const char *name,
				  struct ocfs2_xattr_search *xs)
{
	struct ocfs2_dinode *di = (struct ocfs2_dinode *)xs->inode_bh->b_data;
	struct buffer_head *blk_bh = NULL;
	struct ocfs2_xattr_block *xb;
	int ret = 0;

	if (!di->i_xattr_loc)
		return ret;

	ret = ocfs2_read_block(OCFS2_SB(inode->i_sb),
			       le64_to_cpu(di->i_xattr_loc),
			       &blk_bh, OCFS2_BH_CACHED, inode);
	if (ret < 0) {
		mlog_errno(ret);
		return ret;
	}
	/*Verify the signature of xattr block*/
	if (memcmp((void *)blk_bh->b_data, OCFS2_XATTR_BLOCK_SIGNATURE,
		   strlen(OCFS2_XATTR_BLOCK_SIGNATURE))) {
			ret = -EFAULT;
			goto cleanup;
	}

	xs->xattr_bh = blk_bh;
	xb = (struct ocfs2_xattr_block *)blk_bh->b_data;

	if (!(le16_to_cpu(xb->xb_flags) & OCFS2_XATTR_INDEXED)) {
		xs->header = &xb->xb_attrs.xb_header;
		xs->base = (void *)xs->header;
		xs->end = (void *)(blk_bh->b_data) + blk_bh->b_size;
		xs->here = xs->header->xh_entries;

		ret = ocfs2_xattr_find_entry(name_index, name, xs);
	} else
		ret = ocfs2_xattr_index_block_find(inode, blk_bh,
						   name_index,
						   name, xs);

	if (ret && ret != -ENODATA) {
		xs->xattr_bh = NULL;
		goto cleanup;
	}
	xs->not_found = ret;
	return 0;
cleanup:
	brelse(blk_bh);

	return ret;
}

/*
 * When all the xattrs are deleted from index btree, the ocfs2_xattr_tree
 * will be erased and ocfs2_xattr_block will have its ocfs2_xattr_header
 * re-initialized.
 */
static int ocfs2_restore_xattr_block(struct inode *inode,
				     struct ocfs2_xattr_search *xs)
{
	int ret;
	handle_t *handle;
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
	struct ocfs2_xattr_block *xb =
		(struct ocfs2_xattr_block *)xs->xattr_bh->b_data;
	struct ocfs2_extent_list *el = &xb->xb_attrs.xb_root.xt_list;
	u16 xb_flags = le16_to_cpu(xb->xb_flags);

	BUG_ON(!(xb_flags & OCFS2_XATTR_INDEXED) ||
		le16_to_cpu(el->l_next_free_rec) != 0);

	handle = ocfs2_start_trans(osb, OCFS2_XATTR_BLOCK_UPDATE_CREDITS);
	if (IS_ERR(handle)) {
		ret = PTR_ERR(handle);
		handle = NULL;
		goto out;
	}

	ret = ocfs2_journal_access(handle, inode, xs->xattr_bh,
				   OCFS2_JOURNAL_ACCESS_WRITE);
	if (ret < 0) {
		mlog_errno(ret);
		goto out_commit;
	}

	memset(&xb->xb_attrs, 0, inode->i_sb->s_blocksize -
	       offsetof(struct ocfs2_xattr_block, xb_attrs));

	xb->xb_flags = cpu_to_le16(xb_flags & ~OCFS2_XATTR_INDEXED);

	ocfs2_journal_dirty(handle, xs->xattr_bh);

out_commit:
	ocfs2_commit_trans(osb, handle);
out:
	return ret;
}

/*
 * ocfs2_xattr_block_set()
 *
 * Set, replace or remove an extended attribute into external block.
 *
 */
static int ocfs2_xattr_block_set(struct inode *inode,
				 struct ocfs2_xattr_info *xi,
				 struct ocfs2_xattr_search *xs)
{
	struct buffer_head *new_bh = NULL;
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
	struct ocfs2_dinode *di =  (struct ocfs2_dinode *)xs->inode_bh->b_data;
	struct ocfs2_alloc_context *meta_ac = NULL;
	handle_t *handle = NULL;
	struct ocfs2_xattr_block *xblk = NULL;
	u16 suballoc_bit_start;
	u32 num_got;
	u64 first_blkno;
	int ret;

	if (!xs->xattr_bh) {
		/*
		 * Alloc one external block for extended attribute
		 * outside of inode.
		 */
		ret = ocfs2_reserve_new_metadata_blocks(osb, 1, &meta_ac);
		if (ret < 0) {
			mlog_errno(ret);
			goto out;
		}
		handle = ocfs2_start_trans(osb,
					   OCFS2_XATTR_BLOCK_CREATE_CREDITS);
		if (IS_ERR(handle)) {
			ret = PTR_ERR(handle);
			mlog_errno(ret);
			goto out;
		}
		ret = ocfs2_journal_access(handle, inode, xs->inode_bh,
					   OCFS2_JOURNAL_ACCESS_CREATE);
		if (ret < 0) {
			mlog_errno(ret);
			goto out_commit;
		}

		ret = ocfs2_claim_metadata(osb, handle, meta_ac, 1,
					   &suballoc_bit_start, &num_got,
					   &first_blkno);
		if (ret < 0) {
			mlog_errno(ret);
			goto out_commit;
		}

		new_bh = sb_getblk(inode->i_sb, first_blkno);
		ocfs2_set_new_buffer_uptodate(inode, new_bh);

		ret = ocfs2_journal_access(handle, inode, new_bh,
					   OCFS2_JOURNAL_ACCESS_CREATE);
		if (ret < 0) {
			mlog_errno(ret);
			goto out_commit;
		}

		/* Initialize ocfs2_xattr_block */
		xs->xattr_bh = new_bh;
		xblk = (struct ocfs2_xattr_block *)new_bh->b_data;
		memset(xblk, 0, inode->i_sb->s_blocksize);
		strcpy((void *)xblk, OCFS2_XATTR_BLOCK_SIGNATURE);
		xblk->xb_suballoc_slot = cpu_to_le16(osb->slot_num);
		xblk->xb_suballoc_bit = cpu_to_le16(suballoc_bit_start);
		xblk->xb_fs_generation = cpu_to_le32(osb->fs_generation);
		xblk->xb_blkno = cpu_to_le64(first_blkno);

		xs->header = &xblk->xb_attrs.xb_header;
		xs->base = (void *)xs->header;
		xs->end = (void *)xblk + inode->i_sb->s_blocksize;
		xs->here = xs->header->xh_entries;


		ret = ocfs2_journal_dirty(handle, new_bh);
		if (ret < 0) {
			mlog_errno(ret);
			goto out_commit;
		}
		di->i_xattr_loc = cpu_to_le64(first_blkno);
		ret = ocfs2_journal_dirty(handle, xs->inode_bh);
		if (ret < 0)
			mlog_errno(ret);
out_commit:
		ocfs2_commit_trans(osb, handle);
out:
		if (meta_ac)
			ocfs2_free_alloc_context(meta_ac);
		if (ret < 0)
			return ret;
	} else
		xblk = (struct ocfs2_xattr_block *)xs->xattr_bh->b_data;

	if (!(le16_to_cpu(xblk->xb_flags) & OCFS2_XATTR_INDEXED)) {
		/* Set extended attribute into external block */
		ret = ocfs2_xattr_set_entry(inode, xi, xs, OCFS2_HAS_XATTR_FL);
		if (!ret || ret != -ENOSPC)
			goto end;

		ret = ocfs2_xattr_create_index_block(inode, xs);
		if (ret)
			goto end;
	}

	ret = ocfs2_xattr_set_entry_index_block(inode, xi, xs);
	if (!ret && xblk->xb_attrs.xb_root.xt_list.l_next_free_rec == 0)
		ret = ocfs2_restore_xattr_block(inode, xs);

end:

	return ret;
}

/*
 * ocfs2_xattr_set()
 *
 * Set, replace or remove an extended attribute for this inode.
 * value is NULL to remove an existing extended attribute, else either
 * create or replace an extended attribute.
 */
int ocfs2_xattr_set(struct inode *inode,
		    int name_index,
		    const char *name,
		    const void *value,
		    size_t value_len,
		    int flags)
{
	struct buffer_head *di_bh = NULL;
	struct ocfs2_dinode *di;
	int ret;
	u16 i, blk_per_bucket = ocfs2_blocks_per_xattr_bucket(inode->i_sb);

	struct ocfs2_xattr_info xi = {
		.name_index = name_index,
		.name = name,
		.value = value,
		.value_len = value_len,
	};

	struct ocfs2_xattr_search xis = {
		.not_found = -ENODATA,
	};

	struct ocfs2_xattr_search xbs = {
		.not_found = -ENODATA,
	};

	if (!ocfs2_supports_xattr(OCFS2_SB(inode->i_sb)))
		return -EOPNOTSUPP;

	ret = ocfs2_inode_lock(inode, &di_bh, 1);
	if (ret < 0) {
		mlog_errno(ret);
		return ret;
	}
	xis.inode_bh = xbs.inode_bh = di_bh;
	di = (struct ocfs2_dinode *)di_bh->b_data;

	down_write(&OCFS2_I(inode)->ip_xattr_sem);
	/*
	 * Scan inode and external block to find the same name
	 * extended attribute and collect search infomation.
	 */
	ret = ocfs2_xattr_ibody_find(inode, name_index, name, &xis);
	if (ret)
		goto cleanup;
	if (xis.not_found) {
		ret = ocfs2_xattr_block_find(inode, name_index, name, &xbs);
		if (ret)
			goto cleanup;
	}

	if (xis.not_found && xbs.not_found) {
		ret = -ENODATA;
		if (flags & XATTR_REPLACE)
			goto cleanup;
		ret = 0;
		if (!value)
			goto cleanup;
	} else {
		ret = -EEXIST;
		if (flags & XATTR_CREATE)
			goto cleanup;
	}

	if (!value) {
		/* Remove existing extended attribute */
		if (!xis.not_found)
			ret = ocfs2_xattr_ibody_set(inode, &xi, &xis);
		else if (!xbs.not_found)
			ret = ocfs2_xattr_block_set(inode, &xi, &xbs);
	} else {
		/* We always try to set extended attribute into inode first*/
		ret = ocfs2_xattr_ibody_set(inode, &xi, &xis);
		if (!ret && !xbs.not_found) {
			/*
			 * If succeed and that extended attribute existing in
			 * external block, then we will remove it.
			 */
			xi.value = NULL;
			xi.value_len = 0;
			ret = ocfs2_xattr_block_set(inode, &xi, &xbs);
		} else if (ret == -ENOSPC) {
			if (di->i_xattr_loc && !xbs.xattr_bh) {
				ret = ocfs2_xattr_block_find(inode, name_index,
							     name, &xbs);
				if (ret)
					goto cleanup;
			}
			/*
			 * If no space in inode, we will set extended attribute
			 * into external block.
			 */
			ret = ocfs2_xattr_block_set(inode, &xi, &xbs);
			if (ret)
				goto cleanup;
			if (!xis.not_found) {
				/*
				 * If succeed and that extended attribute
				 * existing in inode, we will remove it.
				 */
				xi.value = NULL;
				xi.value_len = 0;
				ret = ocfs2_xattr_ibody_set(inode, &xi, &xis);
			}
		}
	}
cleanup:
	up_write(&OCFS2_I(inode)->ip_xattr_sem);
	ocfs2_inode_unlock(inode, 1);
	brelse(di_bh);
	brelse(xbs.xattr_bh);
	for (i = 0; i < blk_per_bucket; i++)
		brelse(xbs.bucket.bhs[i]);

	return ret;
}

/*
 * Find the xattr extent rec which may contains name_hash.
 * e_cpos will be the first name hash of the xattr rec.
 * el must be the ocfs2_xattr_header.xb_attrs.xb_root.xt_list.
 */
static int ocfs2_xattr_get_rec(struct inode *inode,
			       u32 name_hash,
			       u64 *p_blkno,
			       u32 *e_cpos,
			       u32 *num_clusters,
			       struct ocfs2_extent_list *el)
{
	int ret = 0, i;
	struct buffer_head *eb_bh = NULL;
	struct ocfs2_extent_block *eb;
	struct ocfs2_extent_rec *rec = NULL;
	u64 e_blkno = 0;

	if (el->l_tree_depth) {
		ret = ocfs2_find_leaf(inode, el, name_hash, &eb_bh);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

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

		if (el->l_tree_depth) {
			ocfs2_error(inode->i_sb,
				    "Inode %lu has non zero tree depth in "
				    "xattr tree block %llu\n", inode->i_ino,
				    (unsigned long long)eb_bh->b_blocknr);
			ret = -EROFS;
			goto out;
		}
	}

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

		if (le32_to_cpu(rec->e_cpos) <= name_hash) {
			e_blkno = le64_to_cpu(rec->e_blkno);
			break;
		}
	}

	if (!e_blkno) {
		ocfs2_error(inode->i_sb, "Inode %lu has bad extent "
			    "record (%u, %u, 0) in xattr", inode->i_ino,
			    le32_to_cpu(rec->e_cpos),
			    ocfs2_rec_clusters(el, rec));
		ret = -EROFS;
		goto out;
	}

	*p_blkno = le64_to_cpu(rec->e_blkno);
	*num_clusters = le16_to_cpu(rec->e_leaf_clusters);
	if (e_cpos)
		*e_cpos = le32_to_cpu(rec->e_cpos);
out:
	brelse(eb_bh);
	return ret;
}

typedef int (xattr_bucket_func)(struct inode *inode,
				struct ocfs2_xattr_bucket *bucket,
				void *para);

static int ocfs2_find_xe_in_bucket(struct inode *inode,
				   struct buffer_head *header_bh,
				   int name_index,
				   const char *name,
				   u32 name_hash,
				   u16 *xe_index,
				   int *found)
{
	int i, ret = 0, cmp = 1, block_off, new_offset;
	struct ocfs2_xattr_header *xh =
			(struct ocfs2_xattr_header *)header_bh->b_data;
	size_t name_len = strlen(name);
	struct ocfs2_xattr_entry *xe = NULL;
	struct buffer_head *name_bh = NULL;
	char *xe_name;

	/*
	 * We don't use binary search in the bucket because there
	 * may be multiple entries with the same name hash.
	 */
	for (i = 0; i < le16_to_cpu(xh->xh_count); i++) {
		xe = &xh->xh_entries[i];

		if (name_hash > le32_to_cpu(xe->xe_name_hash))
			continue;
		else if (name_hash < le32_to_cpu(xe->xe_name_hash))
			break;

		cmp = name_index - ocfs2_xattr_get_type(xe);
		if (!cmp)
			cmp = name_len - xe->xe_name_len;
		if (cmp)
			continue;

		ret = ocfs2_xattr_bucket_get_name_value(inode,
							xh,
							i,
							&block_off,
							&new_offset);
		if (ret) {
			mlog_errno(ret);
			break;
		}

		ret = ocfs2_read_block(OCFS2_SB(inode->i_sb),
				       header_bh->b_blocknr + block_off,
				       &name_bh, OCFS2_BH_CACHED, inode);
		if (ret) {
			mlog_errno(ret);
			break;
		}
		xe_name = name_bh->b_data + new_offset;

		cmp = memcmp(name, xe_name, name_len);
		brelse(name_bh);
		name_bh = NULL;

		if (cmp == 0) {
			*xe_index = i;
			*found = 1;
			ret = 0;
			break;
		}
	}

	return ret;
}

/*
 * Find the specified xattr entry in a series of buckets.
 * This series start from p_blkno and last for num_clusters.
 * The ocfs2_xattr_header.xh_num_buckets of the first bucket contains
 * the num of the valid buckets.
 *
 * Return the buffer_head this xattr should reside in. And if the xattr's
 * hash is in the gap of 2 buckets, return the lower bucket.
 */
static int ocfs2_xattr_bucket_find(struct inode *inode,
				   int name_index,
				   const char *name,
				   u32 name_hash,
				   u64 p_blkno,
				   u32 first_hash,
				   u32 num_clusters,
				   struct ocfs2_xattr_search *xs)
{
	int ret, found = 0;
	struct buffer_head *bh = NULL;
	struct buffer_head *lower_bh = NULL;
	struct ocfs2_xattr_header *xh = NULL;
	struct ocfs2_xattr_entry *xe = NULL;
	u16 index = 0;
	u16 blk_per_bucket = ocfs2_blocks_per_xattr_bucket(inode->i_sb);
	int low_bucket = 0, bucket, high_bucket;
	u32 last_hash;
	u64 blkno;

	ret = ocfs2_read_block(OCFS2_SB(inode->i_sb), p_blkno,
			       &bh, OCFS2_BH_CACHED, inode);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	xh = (struct ocfs2_xattr_header *)bh->b_data;
	high_bucket = le16_to_cpu(xh->xh_num_buckets) - 1;

	while (low_bucket <= high_bucket) {
		brelse(bh);
		bh = NULL;
		bucket = (low_bucket + high_bucket) / 2;

		blkno = p_blkno + bucket * blk_per_bucket;

		ret = ocfs2_read_block(OCFS2_SB(inode->i_sb), blkno,
				       &bh, OCFS2_BH_CACHED, inode);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		xh = (struct ocfs2_xattr_header *)bh->b_data;
		xe = &xh->xh_entries[0];
		if (name_hash < le32_to_cpu(xe->xe_name_hash)) {
			high_bucket = bucket - 1;
			continue;
		}

		/*
		 * Check whether the hash of the last entry in our
		 * bucket is larger than the search one. for an empty
		 * bucket, the last one is also the first one.
		 */
		if (xh->xh_count)
			xe = &xh->xh_entries[le16_to_cpu(xh->xh_count) - 1];

		last_hash = le32_to_cpu(xe->xe_name_hash);

		/* record lower_bh which may be the insert place. */
		brelse(lower_bh);
		lower_bh = bh;
		bh = NULL;

		if (name_hash > le32_to_cpu(xe->xe_name_hash)) {
			low_bucket = bucket + 1;
			continue;
		}

		/* the searched xattr should reside in this bucket if exists. */
		ret = ocfs2_find_xe_in_bucket(inode, lower_bh,
					      name_index, name, name_hash,
					      &index, &found);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}
		break;
	}

	/*
	 * Record the bucket we have found.
	 * When the xattr's hash value is in the gap of 2 buckets, we will
	 * always set it to the previous bucket.
	 */
	if (!lower_bh) {
		/*
		 * We can't find any bucket whose first name_hash is less
		 * than the find name_hash.
		 */
		BUG_ON(bh->b_blocknr != p_blkno);
		lower_bh = bh;
		bh = NULL;
	}
	xs->bucket.bhs[0] = lower_bh;
	xs->bucket.xh = (struct ocfs2_xattr_header *)
					xs->bucket.bhs[0]->b_data;
	lower_bh = NULL;

	xs->header = xs->bucket.xh;
	xs->base = xs->bucket.bhs[0]->b_data;
	xs->end = xs->base + inode->i_sb->s_blocksize;

	if (found) {
		/*
		 * If we have found the xattr enty, read all the blocks in
		 * this bucket.
		 */
		ret = ocfs2_read_blocks(OCFS2_SB(inode->i_sb),
					xs->bucket.bhs[0]->b_blocknr + 1,
					blk_per_bucket - 1, &xs->bucket.bhs[1],
					OCFS2_BH_CACHED, inode);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		xs->here = &xs->header->xh_entries[index];
		mlog(0, "find xattr %s in bucket %llu, entry = %u\n", name,
		     (unsigned long long)xs->bucket.bhs[0]->b_blocknr, index);
	} else
		ret = -ENODATA;

out:
	brelse(bh);
	brelse(lower_bh);
	return ret;
}

static int ocfs2_xattr_index_block_find(struct inode *inode,
					struct buffer_head *root_bh,
					int name_index,
					const char *name,
					struct ocfs2_xattr_search *xs)
{
	int ret;
	struct ocfs2_xattr_block *xb =
			(struct ocfs2_xattr_block *)root_bh->b_data;
	struct ocfs2_xattr_tree_root *xb_root = &xb->xb_attrs.xb_root;
	struct ocfs2_extent_list *el = &xb_root->xt_list;
	u64 p_blkno = 0;
	u32 first_hash, num_clusters = 0;
	u32 name_hash = ocfs2_xattr_name_hash(inode, name, strlen(name));

	if (le16_to_cpu(el->l_next_free_rec) == 0)
		return -ENODATA;

	mlog(0, "find xattr %s, hash = %u, index = %d in xattr tree\n",
	     name, name_hash, name_index);

	ret = ocfs2_xattr_get_rec(inode, name_hash, &p_blkno, &first_hash,
				  &num_clusters, el);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	BUG_ON(p_blkno == 0 || num_clusters == 0 || first_hash > name_hash);

	mlog(0, "find xattr extent rec %u clusters from %llu, the first hash "
	     "in the rec is %u\n", num_clusters, p_blkno, first_hash);

	ret = ocfs2_xattr_bucket_find(inode, name_index, name, name_hash,
				      p_blkno, first_hash, num_clusters, xs);

out:
	return ret;
}

static int ocfs2_iterate_xattr_buckets(struct inode *inode,
				       u64 blkno,
				       u32 clusters,
				       xattr_bucket_func *func,
				       void *para)
{
	int i, j, ret = 0;
	int blk_per_bucket = ocfs2_blocks_per_xattr_bucket(inode->i_sb);
	u32 bpc = ocfs2_xattr_buckets_per_cluster(OCFS2_SB(inode->i_sb));
	u32 num_buckets = clusters * bpc;
	struct ocfs2_xattr_bucket bucket;

	memset(&bucket, 0, sizeof(bucket));

	mlog(0, "iterating xattr buckets in %u clusters starting from %llu\n",
	     clusters, blkno);

	for (i = 0; i < num_buckets; i++, blkno += blk_per_bucket) {
		ret = ocfs2_read_blocks(OCFS2_SB(inode->i_sb),
					blkno, blk_per_bucket,
					bucket.bhs, OCFS2_BH_CACHED, inode);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		bucket.xh = (struct ocfs2_xattr_header *)bucket.bhs[0]->b_data;
		/*
		 * The real bucket num in this series of blocks is stored
		 * in the 1st bucket.
		 */
		if (i == 0)
			num_buckets = le16_to_cpu(bucket.xh->xh_num_buckets);

		mlog(0, "iterating xattr bucket %llu, first hash %u\n", blkno,
		     le32_to_cpu(bucket.xh->xh_entries[0].xe_name_hash));
		if (func) {
			ret = func(inode, &bucket, para);
			if (ret) {
				mlog_errno(ret);
				break;
			}
		}

		for (j = 0; j < blk_per_bucket; j++)
			brelse(bucket.bhs[j]);
		memset(&bucket, 0, sizeof(bucket));
	}

out:
	for (j = 0; j < blk_per_bucket; j++)
		brelse(bucket.bhs[j]);

	return ret;
}

struct ocfs2_xattr_tree_list {
	char *buffer;
	size_t buffer_size;
	size_t result;
};

static int ocfs2_xattr_bucket_get_name_value(struct inode *inode,
					     struct ocfs2_xattr_header *xh,
					     int index,
					     int *block_off,
					     int *new_offset)
{
	u16 name_offset;

	if (index < 0 || index >= le16_to_cpu(xh->xh_count))
		return -EINVAL;

	name_offset = le16_to_cpu(xh->xh_entries[index].xe_name_offset);

	*block_off = name_offset >> inode->i_sb->s_blocksize_bits;
	*new_offset = name_offset % inode->i_sb->s_blocksize;

	return 0;
}

static int ocfs2_list_xattr_bucket(struct inode *inode,
				   struct ocfs2_xattr_bucket *bucket,
				   void *para)
{
	int ret = 0, type;
	struct ocfs2_xattr_tree_list *xl = (struct ocfs2_xattr_tree_list *)para;
	int i, block_off, new_offset;
	const char *prefix, *name;

	for (i = 0 ; i < le16_to_cpu(bucket->xh->xh_count); i++) {
		struct ocfs2_xattr_entry *entry = &bucket->xh->xh_entries[i];
		type = ocfs2_xattr_get_type(entry);
		prefix = ocfs2_xattr_prefix(type);

		if (prefix) {
			ret = ocfs2_xattr_bucket_get_name_value(inode,
								bucket->xh,
								i,
								&block_off,
								&new_offset);
			if (ret)
				break;

			name = (const char *)bucket->bhs[block_off]->b_data +
				new_offset;
			ret = ocfs2_xattr_list_entry(xl->buffer,
						     xl->buffer_size,
						     &xl->result,
						     prefix, name,
						     entry->xe_name_len);
			if (ret)
				break;
		}
	}

	return ret;
}

static int ocfs2_xattr_tree_list_index_block(struct inode *inode,
					     struct ocfs2_xattr_tree_root *xt,
					     char *buffer,
					     size_t buffer_size)
{
	struct ocfs2_extent_list *el = &xt->xt_list;
	int ret = 0;
	u32 name_hash = UINT_MAX, e_cpos = 0, num_clusters = 0;
	u64 p_blkno = 0;
	struct ocfs2_xattr_tree_list xl = {
		.buffer = buffer,
		.buffer_size = buffer_size,
		.result = 0,
	};

	if (le16_to_cpu(el->l_next_free_rec) == 0)
		return 0;

	while (name_hash > 0) {
		ret = ocfs2_xattr_get_rec(inode, name_hash, &p_blkno,
					  &e_cpos, &num_clusters, el);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		ret = ocfs2_iterate_xattr_buckets(inode, p_blkno, num_clusters,
						  ocfs2_list_xattr_bucket,
						  &xl);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		if (e_cpos == 0)
			break;

		name_hash = e_cpos - 1;
	}

	ret = xl.result;
out:
	return ret;
}

static int cmp_xe(const void *a, const void *b)
{
	const struct ocfs2_xattr_entry *l = a, *r = b;
	u32 l_hash = le32_to_cpu(l->xe_name_hash);
	u32 r_hash = le32_to_cpu(r->xe_name_hash);

	if (l_hash > r_hash)
		return 1;
	if (l_hash < r_hash)
		return -1;
	return 0;
}

static void swap_xe(void *a, void *b, int size)
{
	struct ocfs2_xattr_entry *l = a, *r = b, tmp;

	tmp = *l;
	memcpy(l, r, sizeof(struct ocfs2_xattr_entry));
	memcpy(r, &tmp, sizeof(struct ocfs2_xattr_entry));
}

/*
 * When the ocfs2_xattr_block is filled up, new bucket will be created
 * and all the xattr entries will be moved to the new bucket.
 * Note: we need to sort the entries since they are not saved in order
 * in the ocfs2_xattr_block.
 */
static void ocfs2_cp_xattr_block_to_bucket(struct inode *inode,
					   struct buffer_head *xb_bh,
					   struct buffer_head *xh_bh,
					   struct buffer_head *data_bh)
{
	int i, blocksize = inode->i_sb->s_blocksize;
	u16 offset, size, off_change;
	struct ocfs2_xattr_entry *xe;
	struct ocfs2_xattr_block *xb =
				(struct ocfs2_xattr_block *)xb_bh->b_data;
	struct ocfs2_xattr_header *xb_xh = &xb->xb_attrs.xb_header;
	struct ocfs2_xattr_header *xh =
				(struct ocfs2_xattr_header *)xh_bh->b_data;
	u16 count = le16_to_cpu(xb_xh->xh_count);
	char *target = xh_bh->b_data, *src = xb_bh->b_data;

	mlog(0, "cp xattr from block %llu to bucket %llu\n",
	     (unsigned long long)xb_bh->b_blocknr,
	     (unsigned long long)xh_bh->b_blocknr);

	memset(xh_bh->b_data, 0, blocksize);
	if (data_bh)
		memset(data_bh->b_data, 0, blocksize);
	/*
	 * Since the xe_name_offset is based on ocfs2_xattr_header,
	 * there is a offset change corresponding to the change of
	 * ocfs2_xattr_header's position.
	 */
	off_change = offsetof(struct ocfs2_xattr_block, xb_attrs.xb_header);
	xe = &xb_xh->xh_entries[count - 1];
	offset = le16_to_cpu(xe->xe_name_offset) + off_change;
	size = blocksize - offset;

	/* copy all the names and values. */
	if (data_bh)
		target = data_bh->b_data;
	memcpy(target + offset, src + offset, size);

	/* Init new header now. */
	xh->xh_count = xb_xh->xh_count;
	xh->xh_num_buckets = cpu_to_le16(1);
	xh->xh_name_value_len = cpu_to_le16(size);
	xh->xh_free_start = cpu_to_le16(OCFS2_XATTR_BUCKET_SIZE - size);

	/* copy all the entries. */
	target = xh_bh->b_data;
	offset = offsetof(struct ocfs2_xattr_header, xh_entries);
	size = count * sizeof(struct ocfs2_xattr_entry);
	memcpy(target + offset, (char *)xb_xh + offset, size);

	/* Change the xe offset for all the xe because of the move. */
	off_change = OCFS2_XATTR_BUCKET_SIZE - blocksize +
		 offsetof(struct ocfs2_xattr_block, xb_attrs.xb_header);
	for (i = 0; i < count; i++)
		le16_add_cpu(&xh->xh_entries[i].xe_name_offset, off_change);

	mlog(0, "copy entry: start = %u, size = %u, offset_change = %u\n",
	     offset, size, off_change);

	sort(target + offset, count, sizeof(struct ocfs2_xattr_entry),
	     cmp_xe, swap_xe);
}

/*
 * After we move xattr from block to index btree, we have to
 * update ocfs2_xattr_search to the new xe and base.
 *
 * When the entry is in xattr block, xattr_bh indicates the storage place.
 * While if the entry is in index b-tree, "bucket" indicates the
 * real place of the xattr.
 */
static int ocfs2_xattr_update_xattr_search(struct inode *inode,
					   struct ocfs2_xattr_search *xs,
					   struct buffer_head *old_bh,
					   struct buffer_head *new_bh)
{
	int ret = 0;
	char *buf = old_bh->b_data;
	struct ocfs2_xattr_block *old_xb = (struct ocfs2_xattr_block *)buf;
	struct ocfs2_xattr_header *old_xh = &old_xb->xb_attrs.xb_header;
	int i, blocksize = inode->i_sb->s_blocksize;
	u16 blk_per_bucket = ocfs2_blocks_per_xattr_bucket(inode->i_sb);

	xs->bucket.bhs[0] = new_bh;
	get_bh(new_bh);
	xs->bucket.xh = (struct ocfs2_xattr_header *)xs->bucket.bhs[0]->b_data;
	xs->header = xs->bucket.xh;

	xs->base = new_bh->b_data;
	xs->end = xs->base + inode->i_sb->s_blocksize;

	if (!xs->not_found) {
		if (OCFS2_XATTR_BUCKET_SIZE != blocksize) {
			ret = ocfs2_read_blocks(OCFS2_SB(inode->i_sb),
					xs->bucket.bhs[0]->b_blocknr + 1,
					blk_per_bucket - 1, &xs->bucket.bhs[1],
					OCFS2_BH_CACHED, inode);
			if (ret) {
				mlog_errno(ret);
				return ret;
			}

			i = xs->here - old_xh->xh_entries;
			xs->here = &xs->header->xh_entries[i];
		}
	}

	return ret;
}

static int ocfs2_xattr_create_index_block(struct inode *inode,
					  struct ocfs2_xattr_search *xs)
{
	int ret, credits = OCFS2_SUBALLOC_ALLOC;
	u32 bit_off, len;
	u64 blkno;
	handle_t *handle;
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
	struct ocfs2_inode_info *oi = OCFS2_I(inode);
	struct ocfs2_alloc_context *data_ac;
	struct buffer_head *xh_bh = NULL, *data_bh = NULL;
	struct buffer_head *xb_bh = xs->xattr_bh;
	struct ocfs2_xattr_block *xb =
			(struct ocfs2_xattr_block *)xb_bh->b_data;
	struct ocfs2_xattr_tree_root *xr;
	u16 xb_flags = le16_to_cpu(xb->xb_flags);
	u16 bpb = ocfs2_blocks_per_xattr_bucket(inode->i_sb);

	mlog(0, "create xattr index block for %llu\n",
	     (unsigned long long)xb_bh->b_blocknr);

	BUG_ON(xb_flags & OCFS2_XATTR_INDEXED);

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

	/*
	 * XXX:
	 * We can use this lock for now, and maybe move to a dedicated mutex
	 * if performance becomes a problem later.
	 */
	down_write(&oi->ip_alloc_sem);

	/*
	 * 3 more credits, one for xattr block update, one for the 1st block
	 * of the new xattr bucket and one for the value/data.
	 */
	credits += 3;
	handle = ocfs2_start_trans(osb, credits);
	if (IS_ERR(handle)) {
		ret = PTR_ERR(handle);
		mlog_errno(ret);
		goto out_sem;
	}

	ret = ocfs2_journal_access(handle, inode, xb_bh,
				   OCFS2_JOURNAL_ACCESS_WRITE);
	if (ret) {
		mlog_errno(ret);
		goto out_commit;
	}

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

	/*
	 * The bucket may spread in many blocks, and
	 * we will only touch the 1st block and the last block
	 * in the whole bucket(one for entry and one for data).
	 */
	blkno = ocfs2_clusters_to_blocks(inode->i_sb, bit_off);

	mlog(0, "allocate 1 cluster from %llu to xattr block\n", blkno);

	xh_bh = sb_getblk(inode->i_sb, blkno);
	if (!xh_bh) {
		ret = -EIO;
		mlog_errno(ret);
		goto out_commit;
	}

	ocfs2_set_new_buffer_uptodate(inode, xh_bh);

	ret = ocfs2_journal_access(handle, inode, xh_bh,
				   OCFS2_JOURNAL_ACCESS_CREATE);
	if (ret) {
		mlog_errno(ret);
		goto out_commit;
	}

	if (bpb > 1) {
		data_bh = sb_getblk(inode->i_sb, blkno + bpb - 1);
		if (!data_bh) {
			ret = -EIO;
			mlog_errno(ret);
			goto out_commit;
		}

		ocfs2_set_new_buffer_uptodate(inode, data_bh);

		ret = ocfs2_journal_access(handle, inode, data_bh,
					   OCFS2_JOURNAL_ACCESS_CREATE);
		if (ret) {
			mlog_errno(ret);
			goto out_commit;
		}
	}

	ocfs2_cp_xattr_block_to_bucket(inode, xb_bh, xh_bh, data_bh);

	ocfs2_journal_dirty(handle, xh_bh);
	if (data_bh)
		ocfs2_journal_dirty(handle, data_bh);

	ocfs2_xattr_update_xattr_search(inode, xs, xb_bh, xh_bh);

	/* Change from ocfs2_xattr_header to ocfs2_xattr_tree_root */
	memset(&xb->xb_attrs, 0, inode->i_sb->s_blocksize -
	       offsetof(struct ocfs2_xattr_block, xb_attrs));

	xr = &xb->xb_attrs.xb_root;
	xr->xt_clusters = cpu_to_le32(1);
	xr->xt_last_eb_blk = 0;
	xr->xt_list.l_tree_depth = 0;
	xr->xt_list.l_count = cpu_to_le16(ocfs2_xattr_recs_per_xb(inode->i_sb));
	xr->xt_list.l_next_free_rec = cpu_to_le16(1);

	xr->xt_list.l_recs[0].e_cpos = 0;
	xr->xt_list.l_recs[0].e_blkno = cpu_to_le64(blkno);
	xr->xt_list.l_recs[0].e_leaf_clusters = cpu_to_le16(1);

	xb->xb_flags = cpu_to_le16(xb_flags | OCFS2_XATTR_INDEXED);

	ret = ocfs2_journal_dirty(handle, xb_bh);
	if (ret) {
		mlog_errno(ret);
		goto out_commit;
	}

out_commit:
	ocfs2_commit_trans(osb, handle);

out_sem:
	up_write(&oi->ip_alloc_sem);

out:
	if (data_ac)
		ocfs2_free_alloc_context(data_ac);

	brelse(xh_bh);
	brelse(data_bh);

	return ret;
}

static int cmp_xe_offset(const void *a, const void *b)
{
	const struct ocfs2_xattr_entry *l = a, *r = b;
	u32 l_name_offset = le16_to_cpu(l->xe_name_offset);
	u32 r_name_offset = le16_to_cpu(r->xe_name_offset);

	if (l_name_offset < r_name_offset)
		return 1;
	if (l_name_offset > r_name_offset)
		return -1;
	return 0;
}

/*
 * defrag a xattr bucket if we find that the bucket has some
 * holes beteen name/value pairs.
 * We will move all the name/value pairs to the end of the bucket
 * so that we can spare some space for insertion.
 */
static int ocfs2_defrag_xattr_bucket(struct inode *inode,
				     struct ocfs2_xattr_bucket *bucket)
{
	int ret, i;
	size_t end, offset, len, value_len;
	struct ocfs2_xattr_header *xh;
	char *entries, *buf, *bucket_buf = NULL;
	u64 blkno = bucket->bhs[0]->b_blocknr;
	u16 blk_per_bucket = ocfs2_blocks_per_xattr_bucket(inode->i_sb);
	u16 xh_free_start;
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
	size_t blocksize = inode->i_sb->s_blocksize;
	handle_t *handle;
	struct buffer_head **bhs;
	struct ocfs2_xattr_entry *xe;

	bhs = kzalloc(sizeof(struct buffer_head *) * blk_per_bucket,
			GFP_NOFS);
	if (!bhs)
		return -ENOMEM;

	ret = ocfs2_read_blocks(osb, blkno, blk_per_bucket, bhs,
				OCFS2_BH_CACHED, inode);
	if (ret)
		goto out;

	/*
	 * In order to make the operation more efficient and generic,
	 * we copy all the blocks into a contiguous memory and do the
	 * defragment there, so if anything is error, we will not touch
	 * the real block.
	 */
	bucket_buf = kmalloc(OCFS2_XATTR_BUCKET_SIZE, GFP_NOFS);
	if (!bucket_buf) {
		ret = -EIO;
		goto out;
	}

	buf = bucket_buf;
	for (i = 0; i < blk_per_bucket; i++, buf += blocksize)
		memcpy(buf, bhs[i]->b_data, blocksize);

	handle = ocfs2_start_trans((OCFS2_SB(inode->i_sb)), blk_per_bucket);
	if (IS_ERR(handle)) {
		ret = PTR_ERR(handle);
		handle = NULL;
		mlog_errno(ret);
		goto out;
	}

	for (i = 0; i < blk_per_bucket; i++) {
		ret = ocfs2_journal_access(handle, inode, bhs[i],
					   OCFS2_JOURNAL_ACCESS_WRITE);
		if (ret < 0) {
			mlog_errno(ret);
			goto commit;
		}
	}

	xh = (struct ocfs2_xattr_header *)bucket_buf;
	entries = (char *)xh->xh_entries;
	xh_free_start = le16_to_cpu(xh->xh_free_start);

	mlog(0, "adjust xattr bucket in %llu, count = %u, "
	     "xh_free_start = %u, xh_name_value_len = %u.\n",
	     blkno, le16_to_cpu(xh->xh_count), xh_free_start,
	     le16_to_cpu(xh->xh_name_value_len));

	/*
	 * sort all the entries by their offset.
	 * the largest will be the first, so that we can
	 * move them to the end one by one.
	 */
	sort(entries, le16_to_cpu(xh->xh_count),
	     sizeof(struct ocfs2_xattr_entry),
	     cmp_xe_offset, swap_xe);

	/* Move all name/values to the end of the bucket. */
	xe = xh->xh_entries;
	end = OCFS2_XATTR_BUCKET_SIZE;
	for (i = 0; i < le16_to_cpu(xh->xh_count); i++, xe++) {
		offset = le16_to_cpu(xe->xe_name_offset);
		if (ocfs2_xattr_is_local(xe))
			value_len = OCFS2_XATTR_SIZE(
					le64_to_cpu(xe->xe_value_size));
		else
			value_len = OCFS2_XATTR_ROOT_SIZE;
		len = OCFS2_XATTR_SIZE(xe->xe_name_len) + value_len;

		/*
		 * We must make sure that the name/value pair
		 * exist in the same block. So adjust end to
		 * the previous block end if needed.
		 */
		if (((end - len) / blocksize !=
			(end - 1) / blocksize))
			end = end - end % blocksize;

		if (end > offset + len) {
			memmove(bucket_buf + end - len,
				bucket_buf + offset, len);
			xe->xe_name_offset = cpu_to_le16(end - len);
		}

		mlog_bug_on_msg(end < offset + len, "Defrag check failed for "
				"bucket %llu\n", (unsigned long long)blkno);

		end -= len;
	}

	mlog_bug_on_msg(xh_free_start > end, "Defrag check failed for "
			"bucket %llu\n", (unsigned long long)blkno);

	if (xh_free_start == end)
		goto commit;

	memset(bucket_buf + xh_free_start, 0, end - xh_free_start);
	xh->xh_free_start = cpu_to_le16(end);

	/* sort the entries by their name_hash. */
	sort(entries, le16_to_cpu(xh->xh_count),
	     sizeof(struct ocfs2_xattr_entry),
	     cmp_xe, swap_xe);

	buf = bucket_buf;
	for (i = 0; i < blk_per_bucket; i++, buf += blocksize) {
		memcpy(bhs[i]->b_data, buf, blocksize);
		ocfs2_journal_dirty(handle, bhs[i]);
	}

commit:
	ocfs2_commit_trans(OCFS2_SB(inode->i_sb), handle);
out:

	if (bhs) {
		for (i = 0; i < blk_per_bucket; i++)
			brelse(bhs[i]);
	}
	kfree(bhs);

	kfree(bucket_buf);
	return ret;
}

/*
 * Move half nums of the xattr bucket in the previous cluster to this new
 * cluster. We only touch the last cluster of the previous extend record.
 *
 * first_bh is the first buffer_head of a series of bucket in the same
 * extent rec and header_bh is the header of one bucket in this cluster.
 * They will be updated if we move the data header_bh contains to the new
 * cluster. first_hash will be set as the 1st xe's name_hash of the new cluster.
 */
static int ocfs2_mv_xattr_bucket_cross_cluster(struct inode *inode,
					       handle_t *handle,
					       struct buffer_head **first_bh,
					       struct buffer_head **header_bh,
					       u64 new_blkno,
					       u64 prev_blkno,
					       u32 num_clusters,
					       u32 *first_hash)
{
	int i, ret, credits;
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
	int bpc = ocfs2_clusters_to_blocks(inode->i_sb, 1);
	int num_buckets = ocfs2_xattr_buckets_per_cluster(osb);
	int blocksize = inode->i_sb->s_blocksize;
	struct buffer_head *old_bh, *new_bh, *prev_bh, *new_first_bh = NULL;
	struct ocfs2_xattr_header *new_xh;
	struct ocfs2_xattr_header *xh =
			(struct ocfs2_xattr_header *)((*first_bh)->b_data);

	BUG_ON(le16_to_cpu(xh->xh_num_buckets) < num_buckets);
	BUG_ON(OCFS2_XATTR_BUCKET_SIZE == osb->s_clustersize);

	prev_bh = *first_bh;
	get_bh(prev_bh);
	xh = (struct ocfs2_xattr_header *)prev_bh->b_data;

	prev_blkno += (num_clusters - 1) * bpc + bpc / 2;

	mlog(0, "move half of xattrs in cluster %llu to %llu\n",
	     prev_blkno, new_blkno);

	/*
	 * We need to update the 1st half of the new cluster and
	 * 1 more for the update of the 1st bucket of the previous
	 * extent record.
	 */
	credits = bpc / 2 + 1;
	ret = ocfs2_extend_trans(handle, credits);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	ret = ocfs2_journal_access(handle, inode, prev_bh,
				   OCFS2_JOURNAL_ACCESS_WRITE);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	for (i = 0; i < bpc / 2; i++, prev_blkno++, new_blkno++) {
		old_bh = new_bh = NULL;
		new_bh = sb_getblk(inode->i_sb, new_blkno);
		if (!new_bh) {
			ret = -EIO;
			mlog_errno(ret);
			goto out;
		}

		ocfs2_set_new_buffer_uptodate(inode, new_bh);

		ret = ocfs2_journal_access(handle, inode, new_bh,
					   OCFS2_JOURNAL_ACCESS_CREATE);
		if (ret < 0) {
			mlog_errno(ret);
			brelse(new_bh);
			goto out;
		}

		ret = ocfs2_read_block(osb, prev_blkno,
				       &old_bh, OCFS2_BH_CACHED, inode);
		if (ret < 0) {
			mlog_errno(ret);
			brelse(new_bh);
			goto out;
		}

		memcpy(new_bh->b_data, old_bh->b_data, blocksize);

		if (i == 0) {
			new_xh = (struct ocfs2_xattr_header *)new_bh->b_data;
			new_xh->xh_num_buckets = cpu_to_le16(num_buckets / 2);

			if (first_hash)
				*first_hash = le32_to_cpu(
					new_xh->xh_entries[0].xe_name_hash);
			new_first_bh = new_bh;
			get_bh(new_first_bh);
		}

		ocfs2_journal_dirty(handle, new_bh);

		if (*header_bh == old_bh) {
			brelse(*header_bh);
			*header_bh = new_bh;
			get_bh(*header_bh);

			brelse(*first_bh);
			*first_bh = new_first_bh;
			get_bh(*first_bh);
		}
		brelse(new_bh);
		brelse(old_bh);
	}

	le16_add_cpu(&xh->xh_num_buckets, -(num_buckets / 2));

	ocfs2_journal_dirty(handle, prev_bh);
out:
	brelse(prev_bh);
	brelse(new_first_bh);
	return ret;
}

static int ocfs2_read_xattr_bucket(struct inode *inode,
				   u64 blkno,
				   struct buffer_head **bhs,
				   int new)
{
	int ret = 0;
	u16 i, blk_per_bucket = ocfs2_blocks_per_xattr_bucket(inode->i_sb);

	if (!new)
		return ocfs2_read_blocks(OCFS2_SB(inode->i_sb), blkno,
					 blk_per_bucket, bhs,
					 OCFS2_BH_CACHED, inode);

	for (i = 0; i < blk_per_bucket; i++) {
		bhs[i] = sb_getblk(inode->i_sb, blkno + i);
		if (bhs[i] == NULL) {
			ret = -EIO;
			mlog_errno(ret);
			break;
		}
		ocfs2_set_new_buffer_uptodate(inode, bhs[i]);
	}

	return ret;
}

/*
 * Move half num of the xattrs in old bucket(blk) to new bucket(new_blk).
 * first_hash will record the 1st hash of the new bucket.
 */
static int ocfs2_half_xattr_bucket(struct inode *inode,
				   handle_t *handle,
				   u64 blk,
				   u64 new_blk,
				   u32 *first_hash,
				   int new_bucket_head)
{
	int ret, i;
	u16 count, start, len, name_value_len, xe_len, name_offset;
	u16 blk_per_bucket = ocfs2_blocks_per_xattr_bucket(inode->i_sb);
	struct buffer_head **s_bhs, **t_bhs = NULL;
	struct ocfs2_xattr_header *xh;
	struct ocfs2_xattr_entry *xe;
	int blocksize = inode->i_sb->s_blocksize;

	mlog(0, "move half of xattrs from bucket %llu to %llu\n",
	     blk, new_blk);

	s_bhs = kcalloc(blk_per_bucket, sizeof(struct buffer_head *), GFP_NOFS);
	if (!s_bhs)
		return -ENOMEM;

	ret = ocfs2_read_xattr_bucket(inode, blk, s_bhs, 0);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	ret = ocfs2_journal_access(handle, inode, s_bhs[0],
				   OCFS2_JOURNAL_ACCESS_WRITE);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	t_bhs = kcalloc(blk_per_bucket, sizeof(struct buffer_head *), GFP_NOFS);
	if (!t_bhs) {
		ret = -ENOMEM;
		goto out;
	}

	ret = ocfs2_read_xattr_bucket(inode, new_blk, t_bhs, new_bucket_head);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	for (i = 0; i < blk_per_bucket; i++) {
		ret = ocfs2_journal_access(handle, inode, t_bhs[i],
					   OCFS2_JOURNAL_ACCESS_CREATE);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}
	}

	/* copy the whole bucket to the new first. */
	for (i = 0; i < blk_per_bucket; i++)
		memcpy(t_bhs[i]->b_data, s_bhs[i]->b_data, blocksize);

	/* update the new bucket. */
	xh = (struct ocfs2_xattr_header *)t_bhs[0]->b_data;
	count = le16_to_cpu(xh->xh_count);
	start = count / 2;

	/*
	 * Calculate the total name/value len and xh_free_start for
	 * the old bucket first.
	 */
	name_offset = OCFS2_XATTR_BUCKET_SIZE;
	name_value_len = 0;
	for (i = 0; i < start; i++) {
		xe = &xh->xh_entries[i];
		xe_len = OCFS2_XATTR_SIZE(xe->xe_name_len);
		if (ocfs2_xattr_is_local(xe))
			xe_len +=
			   OCFS2_XATTR_SIZE(le64_to_cpu(xe->xe_value_size));
		else
			xe_len += OCFS2_XATTR_ROOT_SIZE;
		name_value_len += xe_len;
		if (le16_to_cpu(xe->xe_name_offset) < name_offset)
			name_offset = le16_to_cpu(xe->xe_name_offset);
	}

	/*
	 * Now begin the modification to the new bucket.
	 *
	 * In the new bucket, We just move the xattr entry to the beginning
	 * and don't touch the name/value. So there will be some holes in the
	 * bucket, and they will be removed when ocfs2_defrag_xattr_bucket is
	 * called.
	 */
	xe = &xh->xh_entries[start];
	len = sizeof(struct ocfs2_xattr_entry) * (count - start);
	mlog(0, "mv xattr entry len %d from %d to %d\n", len,
	     (int)((char *)xe - (char *)xh),
	     (int)((char *)xh->xh_entries - (char *)xh));
	memmove((char *)xh->xh_entries, (char *)xe, len);
	xe = &xh->xh_entries[count - start];
	len = sizeof(struct ocfs2_xattr_entry) * start;
	memset((char *)xe, 0, len);

	le16_add_cpu(&xh->xh_count, -start);
	le16_add_cpu(&xh->xh_name_value_len, -name_value_len);

	/* Calculate xh_free_start for the new bucket. */
	xh->xh_free_start = cpu_to_le16(OCFS2_XATTR_BUCKET_SIZE);
	for (i = 0; i < le16_to_cpu(xh->xh_count); i++) {
		xe = &xh->xh_entries[i];
		xe_len = OCFS2_XATTR_SIZE(xe->xe_name_len);
		if (ocfs2_xattr_is_local(xe))
			xe_len +=
			   OCFS2_XATTR_SIZE(le64_to_cpu(xe->xe_value_size));
		else
			xe_len += OCFS2_XATTR_ROOT_SIZE;
		if (le16_to_cpu(xe->xe_name_offset) <
		    le16_to_cpu(xh->xh_free_start))
			xh->xh_free_start = xe->xe_name_offset;
	}

	/* set xh->xh_num_buckets for the new xh. */
	if (new_bucket_head)
		xh->xh_num_buckets = cpu_to_le16(1);
	else
		xh->xh_num_buckets = 0;

	for (i = 0; i < blk_per_bucket; i++) {
		ocfs2_journal_dirty(handle, t_bhs[i]);
		if (ret)
			mlog_errno(ret);
	}

	/* store the first_hash of the new bucket. */
	if (first_hash)
		*first_hash = le32_to_cpu(xh->xh_entries[0].xe_name_hash);

	/*
	 * Now only update the 1st block of the old bucket.
	 * Please note that the entry has been sorted already above.
	 */
	xh = (struct ocfs2_xattr_header *)s_bhs[0]->b_data;
	memset(&xh->xh_entries[start], 0,
	       sizeof(struct ocfs2_xattr_entry) * (count - start));
	xh->xh_count = cpu_to_le16(start);
	xh->xh_free_start = cpu_to_le16(name_offset);
	xh->xh_name_value_len = cpu_to_le16(name_value_len);

	ocfs2_journal_dirty(handle, s_bhs[0]);
	if (ret)
		mlog_errno(ret);

out:
	if (s_bhs) {
		for (i = 0; i < blk_per_bucket; i++)
			brelse(s_bhs[i]);
	}
	kfree(s_bhs);

	if (t_bhs) {
		for (i = 0; i < blk_per_bucket; i++)
			brelse(t_bhs[i]);
	}
	kfree(t_bhs);

	return ret;
}

/*
 * Copy xattr from one bucket to another bucket.
 *
 * The caller must make sure that the journal transaction
 * has enough space for journaling.
 */
static int ocfs2_cp_xattr_bucket(struct inode *inode,
				 handle_t *handle,
				 u64 s_blkno,
				 u64 t_blkno,
				 int t_is_new)
{
	int ret, i;
	int blk_per_bucket = ocfs2_blocks_per_xattr_bucket(inode->i_sb);
	int blocksize = inode->i_sb->s_blocksize;
	struct buffer_head **s_bhs, **t_bhs = NULL;

	BUG_ON(s_blkno == t_blkno);

	mlog(0, "cp bucket %llu to %llu, target is %d\n",
	     s_blkno, t_blkno, t_is_new);

	s_bhs = kzalloc(sizeof(struct buffer_head *) * blk_per_bucket,
			GFP_NOFS);
	if (!s_bhs)
		return -ENOMEM;

	ret = ocfs2_read_xattr_bucket(inode, s_blkno, s_bhs, 0);
	if (ret)
		goto out;

	t_bhs = kzalloc(sizeof(struct buffer_head *) * blk_per_bucket,
			GFP_NOFS);
	if (!t_bhs) {
		ret = -ENOMEM;
		goto out;
	}

	ret = ocfs2_read_xattr_bucket(inode, t_blkno, t_bhs, t_is_new);
	if (ret)
		goto out;

	for (i = 0; i < blk_per_bucket; i++) {
		ret = ocfs2_journal_access(handle, inode, t_bhs[i],
					   OCFS2_JOURNAL_ACCESS_WRITE);
		if (ret)
			goto out;
	}

	for (i = 0; i < blk_per_bucket; i++) {
		memcpy(t_bhs[i]->b_data, s_bhs[i]->b_data, blocksize);
		ocfs2_journal_dirty(handle, t_bhs[i]);
	}

out:
	if (s_bhs) {
		for (i = 0; i < blk_per_bucket; i++)
			brelse(s_bhs[i]);
	}
	kfree(s_bhs);

	if (t_bhs) {
		for (i = 0; i < blk_per_bucket; i++)
			brelse(t_bhs[i]);
	}
	kfree(t_bhs);

	return ret;
}

/*
 * Copy one xattr cluster from src_blk to to_blk.
 * The to_blk will become the first bucket header of the cluster, so its
 * xh_num_buckets will be initialized as the bucket num in the cluster.
 */
static int ocfs2_cp_xattr_cluster(struct inode *inode,
				  handle_t *handle,
				  struct buffer_head *first_bh,
				  u64 src_blk,
				  u64 to_blk,
				  u32 *first_hash)
{
	int i, ret, credits;
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
	int bpc = ocfs2_clusters_to_blocks(inode->i_sb, 1);
	int num_buckets = ocfs2_xattr_buckets_per_cluster(osb);
	struct buffer_head *bh = NULL;
	struct ocfs2_xattr_header *xh;
	u64 to_blk_start = to_blk;

	mlog(0, "cp xattrs from cluster %llu to %llu\n", src_blk, to_blk);

	/*
	 * We need to update the new cluster and 1 more for the update of
	 * the 1st bucket of the previous extent rec.
	 */
	credits = bpc + 1;
	ret = ocfs2_extend_trans(handle, credits);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	ret = ocfs2_journal_access(handle, inode, first_bh,
				   OCFS2_JOURNAL_ACCESS_WRITE);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	for (i = 0; i < num_buckets; i++) {
		ret = ocfs2_cp_xattr_bucket(inode, handle,
					    src_blk, to_blk, 1);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		src_blk += ocfs2_blocks_per_xattr_bucket(inode->i_sb);
		to_blk += ocfs2_blocks_per_xattr_bucket(inode->i_sb);
	}

	/* update the old bucket header. */
	xh = (struct ocfs2_xattr_header *)first_bh->b_data;
	le16_add_cpu(&xh->xh_num_buckets, -num_buckets);

	ocfs2_journal_dirty(handle, first_bh);

	/* update the new bucket header. */
	ret = ocfs2_read_block(osb, to_blk_start, &bh, OCFS2_BH_CACHED, inode);
	if (ret < 0) {
		mlog_errno(ret);
		goto out;
	}

	ret = ocfs2_journal_access(handle, inode, bh,
				   OCFS2_JOURNAL_ACCESS_WRITE);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	xh = (struct ocfs2_xattr_header *)bh->b_data;
	xh->xh_num_buckets = cpu_to_le16(num_buckets);

	ocfs2_journal_dirty(handle, bh);

	if (first_hash)
		*first_hash = le32_to_cpu(xh->xh_entries[0].xe_name_hash);
out:
	brelse(bh);
	return ret;
}

/*
 * Move half of the xattrs in this cluster to the new cluster.
 * This function should only be called when bucket size == cluster size.
 * Otherwise ocfs2_mv_xattr_bucket_cross_cluster should be used instead.
 */
static int ocfs2_half_xattr_cluster(struct inode *inode,
				    handle_t *handle,
				    u64 prev_blk,
				    u64 new_blk,
				    u32 *first_hash)
{
	u16 blk_per_bucket = ocfs2_blocks_per_xattr_bucket(inode->i_sb);
	int ret, credits = 2 * blk_per_bucket;

	BUG_ON(OCFS2_XATTR_BUCKET_SIZE < OCFS2_SB(inode->i_sb)->s_clustersize);

	ret = ocfs2_extend_trans(handle, credits);
	if (ret) {
		mlog_errno(ret);
		return ret;
	}

	/* Move half of the xattr in start_blk to the next bucket. */
	return  ocfs2_half_xattr_bucket(inode, handle, prev_blk,
					new_blk, first_hash, 1);
}

/*
 * Move some xattrs from the old cluster to the new one since they are not
 * contiguous in ocfs2 xattr tree.
 *
 * new_blk starts a new separate cluster, and we will move some xattrs from
 * prev_blk to it. v_start will be set as the first name hash value in this
 * new cluster so that it can be used as e_cpos during tree insertion and
 * don't collide with our original b-tree operations. first_bh and header_bh
 * will also be updated since they will be used in ocfs2_extend_xattr_bucket
 * to extend the insert bucket.
 *
 * The problem is how much xattr should we move to the new one and when should
 * we update first_bh and header_bh?
 * 1. If cluster size > bucket size, that means the previous cluster has more
 *    than 1 bucket, so just move half nums of bucket into the new cluster and
 *    update the first_bh and header_bh if the insert bucket has been moved
 *    to the new cluster.
 * 2. If cluster_size == bucket_size:
 *    a) If the previous extent rec has more than one cluster and the insert
 *       place isn't in the last cluster, copy the entire last cluster to the
 *       new one. This time, we don't need to upate the first_bh and header_bh
 *       since they will not be moved into the new cluster.
 *    b) Otherwise, move the bottom half of the xattrs in the last cluster into
 *       the new one. And we set the extend flag to zero if the insert place is
 *       moved into the new allocated cluster since no extend is needed.
 */
static int ocfs2_adjust_xattr_cross_cluster(struct inode *inode,
					    handle_t *handle,
					    struct buffer_head **first_bh,
					    struct buffer_head **header_bh,
					    u64 new_blk,
					    u64 prev_blk,
					    u32 prev_clusters,
					    u32 *v_start,
					    int *extend)
{
	int ret = 0;
	int bpc = ocfs2_clusters_to_blocks(inode->i_sb, 1);

	mlog(0, "adjust xattrs from cluster %llu len %u to %llu\n",
	     prev_blk, prev_clusters, new_blk);

	if (ocfs2_xattr_buckets_per_cluster(OCFS2_SB(inode->i_sb)) > 1)
		ret = ocfs2_mv_xattr_bucket_cross_cluster(inode,
							  handle,
							  first_bh,
							  header_bh,
							  new_blk,
							  prev_blk,
							  prev_clusters,
							  v_start);
	else {
		u64 last_blk = prev_blk + bpc * (prev_clusters - 1);

		if (prev_clusters > 1 && (*header_bh)->b_blocknr != last_blk)
			ret = ocfs2_cp_xattr_cluster(inode, handle, *first_bh,
						     last_blk, new_blk,
						     v_start);
		else {
			ret = ocfs2_half_xattr_cluster(inode, handle,
						       last_blk, new_blk,
						       v_start);

			if ((*header_bh)->b_blocknr == last_blk && extend)
				*extend = 0;
		}
	}

	return ret;
}

/*
 * Add a new cluster for xattr storage.
 *
 * If the new cluster is contiguous with the previous one, it will be
 * appended to the same extent record, and num_clusters will be updated.
 * If not, we will insert a new extent for it and move some xattrs in
 * the last cluster into the new allocated one.
 * We also need to limit the maximum size of a btree leaf, otherwise we'll
 * lose the benefits of hashing because we'll have to search large leaves.
 * So now the maximum size is OCFS2_MAX_XATTR_TREE_LEAF_SIZE(or clustersize,
 * if it's bigger).
 *
 * first_bh is the first block of the previous extent rec and header_bh
 * indicates the bucket we will insert the new xattrs. They will be updated
 * when the header_bh is moved into the new cluster.
 */
static int ocfs2_add_new_xattr_cluster(struct inode *inode,
				       struct buffer_head *root_bh,
				       struct buffer_head **first_bh,
				       struct buffer_head **header_bh,
				       u32 *num_clusters,
				       u32 prev_cpos,
				       u64 prev_blkno,
				       int *extend)
{
	int ret, credits;
	u16 bpc = ocfs2_clusters_to_blocks(inode->i_sb, 1);
	u32 prev_clusters = *num_clusters;
	u32 clusters_to_add = 1, bit_off, num_bits, v_start = 0;
	u64 block;
	handle_t *handle = NULL;
	struct ocfs2_alloc_context *data_ac = NULL;
	struct ocfs2_alloc_context *meta_ac = NULL;
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
	struct ocfs2_extent_tree et;

	mlog(0, "Add new xattr cluster for %llu, previous xattr hash = %u, "
	     "previous xattr blkno = %llu\n",
	     (unsigned long long)OCFS2_I(inode)->ip_blkno,
	     prev_cpos, prev_blkno);

	ocfs2_init_xattr_tree_extent_tree(&et, inode, root_bh);

	ret = ocfs2_lock_allocators(inode, &et, clusters_to_add, 0,
				    &data_ac, &meta_ac);
	if (ret) {
		mlog_errno(ret);
		goto leave;
	}

	credits = ocfs2_calc_extend_credits(osb->sb, et.et_root_el,
					    clusters_to_add);
	handle = ocfs2_start_trans(osb, credits);
	if (IS_ERR(handle)) {
		ret = PTR_ERR(handle);
		handle = NULL;
		mlog_errno(ret);
		goto leave;
	}

	ret = ocfs2_journal_access(handle, inode, root_bh,
				   OCFS2_JOURNAL_ACCESS_WRITE);
	if (ret < 0) {
		mlog_errno(ret);
		goto leave;
	}

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

	BUG_ON(num_bits > clusters_to_add);

	block = ocfs2_clusters_to_blocks(osb->sb, bit_off);
	mlog(0, "Allocating %u clusters at block %u for xattr in inode %llu\n",
	     num_bits, bit_off, (unsigned long long)OCFS2_I(inode)->ip_blkno);

	if (prev_blkno + prev_clusters * bpc == block &&
	    (prev_clusters + num_bits) << osb->s_clustersize_bits <=
	     OCFS2_MAX_XATTR_TREE_LEAF_SIZE) {
		/*
		 * If this cluster is contiguous with the old one and
		 * adding this new cluster, we don't surpass the limit of
		 * OCFS2_MAX_XATTR_TREE_LEAF_SIZE, cool. We will let it be
		 * initialized and used like other buckets in the previous
		 * cluster.
		 * So add it as a contiguous one. The caller will handle
		 * its init process.
		 */
		v_start = prev_cpos + prev_clusters;
		*num_clusters = prev_clusters + num_bits;
		mlog(0, "Add contiguous %u clusters to previous extent rec.\n",
		     num_bits);
	} else {
		ret = ocfs2_adjust_xattr_cross_cluster(inode,
						       handle,
						       first_bh,
						       header_bh,
						       block,
						       prev_blkno,
						       prev_clusters,
						       &v_start,
						       extend);
		if (ret) {
			mlog_errno(ret);
			goto leave;
		}
	}

	if (handle->h_buffer_credits < credits) {
		/*
		 * The journal has been restarted before, and don't
		 * have enough space for the insertion, so extend it
		 * here.
		 */
		ret = ocfs2_extend_trans(handle, credits);
		if (ret) {
			mlog_errno(ret);
			goto leave;
		}
	}
	mlog(0, "Insert %u clusters at block %llu for xattr at %u\n",
	     num_bits, block, v_start);
	ret = ocfs2_insert_extent(osb, handle, inode, &et, v_start, block,
				  num_bits, 0, meta_ac);
	if (ret < 0) {
		mlog_errno(ret);
		goto leave;
	}

	ret = ocfs2_journal_dirty(handle, root_bh);
	if (ret < 0) {
		mlog_errno(ret);
		goto leave;
	}

leave:
	if (handle)
		ocfs2_commit_trans(osb, handle);
	if (data_ac)
		ocfs2_free_alloc_context(data_ac);
	if (meta_ac)
		ocfs2_free_alloc_context(meta_ac);

	return ret;
}

/*
 * Extend a new xattr bucket and move xattrs to the end one by one until
 * We meet with start_bh. Only move half of the xattrs to the bucket after it.
 */
static int ocfs2_extend_xattr_bucket(struct inode *inode,
				     struct buffer_head *first_bh,
				     struct buffer_head *start_bh,
				     u32 num_clusters)
{
	int ret, credits;
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
	u16 blk_per_bucket = ocfs2_blocks_per_xattr_bucket(inode->i_sb);
	u64 start_blk = start_bh->b_blocknr, end_blk;
	u32 num_buckets = num_clusters * ocfs2_xattr_buckets_per_cluster(osb);
	handle_t *handle;
	struct ocfs2_xattr_header *first_xh =
				(struct ocfs2_xattr_header *)first_bh->b_data;
	u16 bucket = le16_to_cpu(first_xh->xh_num_buckets);

	mlog(0, "extend xattr bucket in %llu, xattr extend rec starting "
	     "from %llu, len = %u\n", start_blk,
	     (unsigned long long)first_bh->b_blocknr, num_clusters);

	BUG_ON(bucket >= num_buckets);

	end_blk = first_bh->b_blocknr + (bucket - 1) * blk_per_bucket;

	/*
	 * We will touch all the buckets after the start_bh(include it).
	 * Add one more bucket and modify the first_bh.
	 */
	credits = end_blk - start_blk + 2 * blk_per_bucket + 1;
	handle = ocfs2_start_trans(osb, credits);
	if (IS_ERR(handle)) {
		ret = PTR_ERR(handle);
		handle = NULL;
		mlog_errno(ret);
		goto out;
	}

	ret = ocfs2_journal_access(handle, inode, first_bh,
				   OCFS2_JOURNAL_ACCESS_WRITE);
	if (ret) {
		mlog_errno(ret);
		goto commit;
	}

	while (end_blk != start_blk) {
		ret = ocfs2_cp_xattr_bucket(inode, handle, end_blk,
					    end_blk + blk_per_bucket, 0);
		if (ret)
			goto commit;
		end_blk -= blk_per_bucket;
	}

	/* Move half of the xattr in start_blk to the next bucket. */
	ret = ocfs2_half_xattr_bucket(inode, handle, start_blk,
				      start_blk + blk_per_bucket, NULL, 0);

	le16_add_cpu(&first_xh->xh_num_buckets, 1);
	ocfs2_journal_dirty(handle, first_bh);

commit:
	ocfs2_commit_trans(osb, handle);
out:
	return ret;
}

/*
 * Add new xattr bucket in an extent record and adjust the buckets accordingly.
 * xb_bh is the ocfs2_xattr_block.
 * We will move all the buckets starting from header_bh to the next place. As
 * for this one, half num of its xattrs will be moved to the next one.
 *
 * We will allocate a new cluster if current cluster is full and adjust
 * header_bh and first_bh if the insert place is moved to the new cluster.
 */
static int ocfs2_add_new_xattr_bucket(struct inode *inode,
				      struct buffer_head *xb_bh,
				      struct buffer_head *header_bh)
{
	struct ocfs2_xattr_header *first_xh = NULL;
	struct buffer_head *first_bh = NULL;
	struct ocfs2_xattr_block *xb =
			(struct ocfs2_xattr_block *)xb_bh->b_data;
	struct ocfs2_xattr_tree_root *xb_root = &xb->xb_attrs.xb_root;
	struct ocfs2_extent_list *el = &xb_root->xt_list;
	struct ocfs2_xattr_header *xh =
			(struct ocfs2_xattr_header *)header_bh->b_data;
	u32 name_hash = le32_to_cpu(xh->xh_entries[0].xe_name_hash);
	struct super_block *sb = inode->i_sb;
	struct ocfs2_super *osb = OCFS2_SB(sb);
	int ret, num_buckets, extend = 1;
	u64 p_blkno;
	u32 e_cpos, num_clusters;

	mlog(0, "Add new xattr bucket starting form %llu\n",
	     (unsigned long long)header_bh->b_blocknr);

	/*
	 * Add refrence for header_bh here because it may be
	 * changed in ocfs2_add_new_xattr_cluster and we need
	 * to free it in the end.
	 */
	get_bh(header_bh);

	ret = ocfs2_xattr_get_rec(inode, name_hash, &p_blkno, &e_cpos,
				  &num_clusters, el);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	ret = ocfs2_read_block(osb, p_blkno,
			       &first_bh, OCFS2_BH_CACHED, inode);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	num_buckets = ocfs2_xattr_buckets_per_cluster(osb) * num_clusters;
	first_xh = (struct ocfs2_xattr_header *)first_bh->b_data;

	if (num_buckets == le16_to_cpu(first_xh->xh_num_buckets)) {
		ret = ocfs2_add_new_xattr_cluster(inode,
						  xb_bh,
						  &first_bh,
						  &header_bh,
						  &num_clusters,
						  e_cpos,
						  p_blkno,
						  &extend);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}
	}

	if (extend)
		ret = ocfs2_extend_xattr_bucket(inode,
						first_bh,
						header_bh,
						num_clusters);
	if (ret)
		mlog_errno(ret);
out:
	brelse(first_bh);
	brelse(header_bh);
	return ret;
}

static inline char *ocfs2_xattr_bucket_get_val(struct inode *inode,
					struct ocfs2_xattr_bucket *bucket,
					int offs)
{
	int block_off = offs >> inode->i_sb->s_blocksize_bits;

	offs = offs % inode->i_sb->s_blocksize;
	return bucket->bhs[block_off]->b_data + offs;
}

/*
 * Handle the normal xattr set, including replace, delete and new.
 *
 * Note: "local" indicates the real data's locality. So we can't
 * just its bucket locality by its length.
 */
static void ocfs2_xattr_set_entry_normal(struct inode *inode,
					 struct ocfs2_xattr_info *xi,
					 struct ocfs2_xattr_search *xs,
					 u32 name_hash,
					 int local)
{
	struct ocfs2_xattr_entry *last, *xe;
	int name_len = strlen(xi->name);
	struct ocfs2_xattr_header *xh = xs->header;
	u16 count = le16_to_cpu(xh->xh_count), start;
	size_t blocksize = inode->i_sb->s_blocksize;
	char *val;
	size_t offs, size, new_size;

	last = &xh->xh_entries[count];
	if (!xs->not_found) {
		xe = xs->here;
		offs = le16_to_cpu(xe->xe_name_offset);
		if (ocfs2_xattr_is_local(xe))
			size = OCFS2_XATTR_SIZE(name_len) +
			OCFS2_XATTR_SIZE(le64_to_cpu(xe->xe_value_size));
		else
			size = OCFS2_XATTR_SIZE(name_len) +
			OCFS2_XATTR_SIZE(OCFS2_XATTR_ROOT_SIZE);

		/*
		 * If the new value will be stored outside, xi->value has been
		 * initalized as an empty ocfs2_xattr_value_root, and the same
		 * goes with xi->value_len, so we can set new_size safely here.
		 * See ocfs2_xattr_set_in_bucket.
		 */
		new_size = OCFS2_XATTR_SIZE(name_len) +
			   OCFS2_XATTR_SIZE(xi->value_len);

		le16_add_cpu(&xh->xh_name_value_len, -size);
		if (xi->value) {
			if (new_size > size)
				goto set_new_name_value;

			/* Now replace the old value with new one. */
			if (local)
				xe->xe_value_size = cpu_to_le64(xi->value_len);
			else
				xe->xe_value_size = 0;

			val = ocfs2_xattr_bucket_get_val(inode,
							 &xs->bucket, offs);
			memset(val + OCFS2_XATTR_SIZE(name_len), 0,
			       size - OCFS2_XATTR_SIZE(name_len));
			if (OCFS2_XATTR_SIZE(xi->value_len) > 0)
				memcpy(val + OCFS2_XATTR_SIZE(name_len),
				       xi->value, xi->value_len);

			le16_add_cpu(&xh->xh_name_value_len, new_size);
			ocfs2_xattr_set_local(xe, local);
			return;
		} else {
			/*
			 * Remove the old entry if there is more than one.
			 * We don't remove the last entry so that we can
			 * use it to indicate the hash value of the empty
			 * bucket.
			 */
			last -= 1;
			le16_add_cpu(&xh->xh_count, -1);
			if (xh->xh_count) {
				memmove(xe, xe + 1,
					(void *)last - (void *)xe);
				memset(last, 0,
				       sizeof(struct ocfs2_xattr_entry));
			} else
				xh->xh_free_start =
					cpu_to_le16(OCFS2_XATTR_BUCKET_SIZE);

			return;
		}
	} else {
		/* find a new entry for insert. */
		int low = 0, high = count - 1, tmp;
		struct ocfs2_xattr_entry *tmp_xe;

		while (low <= high && count) {
			tmp = (low + high) / 2;
			tmp_xe = &xh->xh_entries[tmp];

			if (name_hash > le32_to_cpu(tmp_xe->xe_name_hash))
				low = tmp + 1;
			else if (name_hash <
				 le32_to_cpu(tmp_xe->xe_name_hash))
				high = tmp - 1;
			else {
				low = tmp;
				break;
			}
		}

		xe = &xh->xh_entries[low];
		if (low != count)
			memmove(xe + 1, xe, (void *)last - (void *)xe);

		le16_add_cpu(&xh->xh_count, 1);
		memset(xe, 0, sizeof(struct ocfs2_xattr_entry));
		xe->xe_name_hash = cpu_to_le32(name_hash);
		xe->xe_name_len = name_len;
		ocfs2_xattr_set_type(xe, xi->name_index);
	}

set_new_name_value:
	/* Insert the new name+value. */
	size = OCFS2_XATTR_SIZE(name_len) + OCFS2_XATTR_SIZE(xi->value_len);

	/*
	 * We must make sure that the name/value pair
	 * exists in the same block.
	 */
	offs = le16_to_cpu(xh->xh_free_start);
	start = offs - size;

	if (start >> inode->i_sb->s_blocksize_bits !=
	    (offs - 1) >> inode->i_sb->s_blocksize_bits) {
		offs = offs - offs % blocksize;
		xh->xh_free_start = cpu_to_le16(offs);
	}

	val = ocfs2_xattr_bucket_get_val(inode,
					 &xs->bucket, offs - size);
	xe->xe_name_offset = cpu_to_le16(offs - size);

	memset(val, 0, size);
	memcpy(val, xi->name, name_len);
	memcpy(val + OCFS2_XATTR_SIZE(name_len), xi->value, xi->value_len);

	xe->xe_value_size = cpu_to_le64(xi->value_len);
	ocfs2_xattr_set_local(xe, local);
	xs->here = xe;
	le16_add_cpu(&xh->xh_free_start, -size);
	le16_add_cpu(&xh->xh_name_value_len, size);

	return;
}

static int ocfs2_xattr_bucket_handle_journal(struct inode *inode,
					     handle_t *handle,
					     struct ocfs2_xattr_search *xs,
					     struct buffer_head **bhs,
					     u16 bh_num)
{
	int ret = 0, off, block_off;
	struct ocfs2_xattr_entry *xe = xs->here;

	/*
	 * First calculate all the blocks we should journal_access
	 * and journal_dirty. The first block should always be touched.
	 */
	ret = ocfs2_journal_dirty(handle, bhs[0]);
	if (ret)
		mlog_errno(ret);

	/* calc the data. */
	off = le16_to_cpu(xe->xe_name_offset);
	block_off = off >> inode->i_sb->s_blocksize_bits;
	ret = ocfs2_journal_dirty(handle, bhs[block_off]);
	if (ret)
		mlog_errno(ret);

	return ret;
}

/*
 * Set the xattr entry in the specified bucket.
 * The bucket is indicated by xs->bucket and it should have the enough
 * space for the xattr insertion.
 */
static int ocfs2_xattr_set_entry_in_bucket(struct inode *inode,
					   struct ocfs2_xattr_info *xi,
					   struct ocfs2_xattr_search *xs,
					   u32 name_hash,
					   int local)
{
	int i, ret;
	handle_t *handle = NULL;
	u16 blk_per_bucket = ocfs2_blocks_per_xattr_bucket(inode->i_sb);
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);

	mlog(0, "Set xattr entry len = %lu index = %d in bucket %llu\n",
	     (unsigned long)xi->value_len, xi->name_index,
	     (unsigned long long)xs->bucket.bhs[0]->b_blocknr);

	if (!xs->bucket.bhs[1]) {
		ret = ocfs2_read_blocks(osb,
					xs->bucket.bhs[0]->b_blocknr + 1,
					blk_per_bucket - 1, &xs->bucket.bhs[1],
					OCFS2_BH_CACHED, inode);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}
	}

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

	for (i = 0; i < blk_per_bucket; i++) {
		ret = ocfs2_journal_access(handle, inode, xs->bucket.bhs[i],
					   OCFS2_JOURNAL_ACCESS_WRITE);
		if (ret < 0) {
			mlog_errno(ret);
			goto out;
		}
	}

	ocfs2_xattr_set_entry_normal(inode, xi, xs, name_hash, local);

	/*Only dirty the blocks we have touched in set xattr. */
	ret = ocfs2_xattr_bucket_handle_journal(inode, handle, xs,
						xs->bucket.bhs, blk_per_bucket);
	if (ret)
		mlog_errno(ret);
out:
	ocfs2_commit_trans(osb, handle);

	return ret;
}

static int ocfs2_xattr_value_update_size(struct inode *inode,
					 struct buffer_head *xe_bh,
					 struct ocfs2_xattr_entry *xe,
					 u64 new_size)
{
	int ret;
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
	handle_t *handle = NULL;

	handle = ocfs2_start_trans(osb, 1);
	if (handle == NULL) {
		ret = -ENOMEM;
		mlog_errno(ret);
		goto out;
	}

	ret = ocfs2_journal_access(handle, inode, xe_bh,
				   OCFS2_JOURNAL_ACCESS_WRITE);
	if (ret < 0) {
		mlog_errno(ret);
		goto out_commit;
	}

	xe->xe_value_size = cpu_to_le64(new_size);

	ret = ocfs2_journal_dirty(handle, xe_bh);
	if (ret < 0)
		mlog_errno(ret);

out_commit:
	ocfs2_commit_trans(osb, handle);
out:
	return ret;
}

/*
 * Truncate the specified xe_off entry in xattr bucket.
 * bucket is indicated by header_bh and len is the new length.
 * Both the ocfs2_xattr_value_root and the entry will be updated here.
 *
 * Copy the new updated xe and xe_value_root to new_xe and new_xv if needed.
 */
static int ocfs2_xattr_bucket_value_truncate(struct inode *inode,
					     struct buffer_head *header_bh,
					     int xe_off,
					     int len)
{
	int ret, offset;
	u64 value_blk;
	struct buffer_head *value_bh = NULL;
	struct ocfs2_xattr_value_root *xv;
	struct ocfs2_xattr_entry *xe;
	struct ocfs2_xattr_header *xh =
			(struct ocfs2_xattr_header *)header_bh->b_data;
	size_t blocksize = inode->i_sb->s_blocksize;

	xe = &xh->xh_entries[xe_off];

	BUG_ON(!xe || ocfs2_xattr_is_local(xe));

	offset = le16_to_cpu(xe->xe_name_offset) +
		 OCFS2_XATTR_SIZE(xe->xe_name_len);

	value_blk = offset / blocksize;

	/* We don't allow ocfs2_xattr_value to be stored in different block. */
	BUG_ON(value_blk != (offset + OCFS2_XATTR_ROOT_SIZE - 1) / blocksize);
	value_blk += header_bh->b_blocknr;

	ret = ocfs2_read_block(OCFS2_SB(inode->i_sb), value_blk,
			       &value_bh, OCFS2_BH_CACHED, inode);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	xv = (struct ocfs2_xattr_value_root *)
		(value_bh->b_data + offset % blocksize);

	mlog(0, "truncate %u in xattr bucket %llu to %d bytes.\n",
	     xe_off, (unsigned long long)header_bh->b_blocknr, len);
	ret = ocfs2_xattr_value_truncate(inode, value_bh, xv, len);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	ret = ocfs2_xattr_value_update_size(inode, header_bh, xe, len);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

out:
	brelse(value_bh);
	return ret;
}

static int ocfs2_xattr_bucket_value_truncate_xs(struct inode *inode,
						struct ocfs2_xattr_search *xs,
						int len)
{
	int ret, offset;
	struct ocfs2_xattr_entry *xe = xs->here;
	struct ocfs2_xattr_header *xh = (struct ocfs2_xattr_header *)xs->base;

	BUG_ON(!xs->bucket.bhs[0] || !xe || ocfs2_xattr_is_local(xe));

	offset = xe - xh->xh_entries;
	ret = ocfs2_xattr_bucket_value_truncate(inode, xs->bucket.bhs[0],
						offset, len);
	if (ret)
		mlog_errno(ret);

	return ret;
}

static int ocfs2_xattr_bucket_set_value_outside(struct inode *inode,
						struct ocfs2_xattr_search *xs,
						char *val,
						int value_len)
{
	int offset;
	struct ocfs2_xattr_value_root *xv;
	struct ocfs2_xattr_entry *xe = xs->here;

	BUG_ON(!xs->base || !xe || ocfs2_xattr_is_local(xe));

	offset = le16_to_cpu(xe->xe_name_offset) +
		 OCFS2_XATTR_SIZE(xe->xe_name_len);

	xv = (struct ocfs2_xattr_value_root *)(xs->base + offset);

	return __ocfs2_xattr_set_value_outside(inode, xv, val, value_len);
}

static int ocfs2_rm_xattr_cluster(struct inode *inode,
				  struct buffer_head *root_bh,
				  u64 blkno,
				  u32 cpos,
				  u32 len)
{
	int ret;
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
	struct inode *tl_inode = osb->osb_tl_inode;
	handle_t *handle;
	struct ocfs2_xattr_block *xb =
			(struct ocfs2_xattr_block *)root_bh->b_data;
	struct ocfs2_alloc_context *meta_ac = NULL;
	struct ocfs2_cached_dealloc_ctxt dealloc;
	struct ocfs2_extent_tree et;

	ocfs2_init_xattr_tree_extent_tree(&et, inode, root_bh);

	ocfs2_init_dealloc_ctxt(&dealloc);

	mlog(0, "rm xattr extent rec at %u len = %u, start from %llu\n",
	     cpos, len, (unsigned long long)blkno);

	ocfs2_remove_xattr_clusters_from_cache(inode, blkno, len);

	ret = ocfs2_lock_allocators(inode, &et, 0, 1, NULL, &meta_ac);
	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);
	if (handle == NULL) {
		ret = -ENOMEM;
		mlog_errno(ret);
		goto out;
	}

	ret = ocfs2_journal_access(handle, inode, root_bh,
				   OCFS2_JOURNAL_ACCESS_WRITE);
	if (ret) {
		mlog_errno(ret);
		goto out_commit;
	}

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

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

	ret = ocfs2_journal_dirty(handle, root_bh);
	if (ret) {
		mlog_errno(ret);
		goto out_commit;
	}

	ret = ocfs2_truncate_log_append(osb, handle, blkno, len);
	if (ret)
		mlog_errno(ret);

out_commit:
	ocfs2_commit_trans(osb, handle);
out:
	ocfs2_schedule_truncate_log_flush(osb, 1);

	mutex_unlock(&tl_inode->i_mutex);

	if (meta_ac)
		ocfs2_free_alloc_context(meta_ac);

	ocfs2_run_deallocs(osb, &dealloc);

	return ret;
}

static void ocfs2_xattr_bucket_remove_xs(struct inode *inode,
					 struct ocfs2_xattr_search *xs)
{
	handle_t *handle = NULL;
	struct ocfs2_xattr_header *xh = xs->bucket.xh;
	struct ocfs2_xattr_entry *last = &xh->xh_entries[
						le16_to_cpu(xh->xh_count) - 1];
	int ret = 0;

	handle = ocfs2_start_trans((OCFS2_SB(inode->i_sb)), 1);
	if (IS_ERR(handle)) {
		ret = PTR_ERR(handle);
		mlog_errno(ret);
		return;
	}

	ret = ocfs2_journal_access(handle, inode, xs->bucket.bhs[0],
				   OCFS2_JOURNAL_ACCESS_WRITE);
	if (ret) {
		mlog_errno(ret);
		goto out_commit;
	}

	/* Remove the old entry. */
	memmove(xs->here, xs->here + 1,
		(void *)last - (void *)xs->here);
	memset(last, 0, sizeof(struct ocfs2_xattr_entry));
	le16_add_cpu(&xh->xh_count, -1);

	ret = ocfs2_journal_dirty(handle, xs->bucket.bhs[0]);
	if (ret < 0)
		mlog_errno(ret);
out_commit:
	ocfs2_commit_trans(OCFS2_SB(inode->i_sb), handle);
}

/*
 * Set the xattr name/value in the bucket specified in xs.
 *
 * As the new value in xi may be stored in the bucket or in an outside cluster,
 * we divide the whole process into 3 steps:
 * 1. insert name/value in the bucket(ocfs2_xattr_set_entry_in_bucket)
 * 2. truncate of the outside cluster(ocfs2_xattr_bucket_value_truncate_xs)
 * 3. Set the value to the outside cluster(ocfs2_xattr_bucket_set_value_outside)
 * 4. If the clusters for the new outside value can't be allocated, we need
 *    to free the xattr we allocated in set.
 */
static int ocfs2_xattr_set_in_bucket(struct inode *inode,
				     struct ocfs2_xattr_info *xi,
				     struct ocfs2_xattr_search *xs)
{
	int ret, local = 1;
	size_t value_len;
	char *val = (char *)xi->value;
	struct ocfs2_xattr_entry *xe = xs->here;
	u32 name_hash = ocfs2_xattr_name_hash(inode, xi->name,
					      strlen(xi->name));

	if (!xs->not_found && !ocfs2_xattr_is_local(xe)) {
		/*
		 * We need to truncate the xattr storage first.
		 *
		 * If both the old and new value are stored to
		 * outside block, we only need to truncate
		 * the storage and then set the value outside.
		 *
		 * If the new value should be stored within block,
		 * we should free all the outside block first and
		 * the modification to the xattr block will be done
		 * by following steps.
		 */
		if (xi->value_len > OCFS2_XATTR_INLINE_SIZE)
			value_len = xi->value_len;
		else
			value_len = 0;

		ret = ocfs2_xattr_bucket_value_truncate_xs(inode, xs,
							   value_len);
		if (ret)
			goto out;

		if (value_len)
			goto set_value_outside;
	}

	value_len = xi->value_len;
	/* So we have to handle the inside block change now. */
	if (value_len > OCFS2_XATTR_INLINE_SIZE) {
		/*
		 * If the new value will be stored outside of block,
		 * initalize a new empty value root and insert it first.
		 */
		local = 0;
		xi->value = &def_xv;
		xi->value_len = OCFS2_XATTR_ROOT_SIZE;
	}

	ret = ocfs2_xattr_set_entry_in_bucket(inode, xi, xs, name_hash, local);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	if (value_len <= OCFS2_XATTR_INLINE_SIZE)
		goto out;

	/* allocate the space now for the outside block storage. */
	ret = ocfs2_xattr_bucket_value_truncate_xs(inode, xs,
						   value_len);
	if (ret) {
		mlog_errno(ret);

		if (xs->not_found) {
			/*
			 * We can't allocate enough clusters for outside
			 * storage and we have allocated xattr already,
			 * so need to remove it.
			 */
			ocfs2_xattr_bucket_remove_xs(inode, xs);
		}
		goto out;
	}

set_value_outside:
	ret = ocfs2_xattr_bucket_set_value_outside(inode, xs, val, value_len);
out:
	return ret;
}

/* check whether the xattr bucket is filled up with the same hash value. */
static int ocfs2_check_xattr_bucket_collision(struct inode *inode,
					      struct ocfs2_xattr_bucket *bucket)
{
	struct ocfs2_xattr_header *xh = bucket->xh;

	if (xh->xh_entries[le16_to_cpu(xh->xh_count) - 1].xe_name_hash ==
	    xh->xh_entries[0].xe_name_hash) {
		mlog(ML_ERROR, "Too much hash collision in xattr bucket %llu, "
		     "hash = %u\n",
		     (unsigned long long)bucket->bhs[0]->b_blocknr,
		     le32_to_cpu(xh->xh_entries[0].xe_name_hash));
		return -ENOSPC;
	}

	return 0;
}

static int ocfs2_xattr_set_entry_index_block(struct inode *inode,
					     struct ocfs2_xattr_info *xi,
					     struct ocfs2_xattr_search *xs)
{
	struct ocfs2_xattr_header *xh;
	struct ocfs2_xattr_entry *xe;
	u16 count, header_size, xh_free_start;
	int i, free, max_free, need, old;
	size_t value_size = 0, name_len = strlen(xi->name);
	size_t blocksize = inode->i_sb->s_blocksize;
	int ret, allocation = 0;
	u16 blk_per_bucket = ocfs2_blocks_per_xattr_bucket(inode->i_sb);

	mlog_entry("Set xattr %s in xattr index block\n", xi->name);

try_again:
	xh = xs->header;
	count = le16_to_cpu(xh->xh_count);
	xh_free_start = le16_to_cpu(xh->xh_free_start);
	header_size = sizeof(struct ocfs2_xattr_header) +
			count * sizeof(struct ocfs2_xattr_entry);
	max_free = OCFS2_XATTR_BUCKET_SIZE -
		le16_to_cpu(xh->xh_name_value_len) - header_size;

	mlog_bug_on_msg(header_size > blocksize, "bucket %llu has header size "
			"of %u which exceed block size\n",
			(unsigned long long)xs->bucket.bhs[0]->b_blocknr,
			header_size);

	if (xi->value && xi->value_len > OCFS2_XATTR_INLINE_SIZE)
		value_size = OCFS2_XATTR_ROOT_SIZE;
	else if (xi->value)
		value_size = OCFS2_XATTR_SIZE(xi->value_len);

	if (xs->not_found)
		need = sizeof(struct ocfs2_xattr_entry) +
			OCFS2_XATTR_SIZE(name_len) + value_size;
	else {
		need = value_size + OCFS2_XATTR_SIZE(name_len);

		/*
		 * We only replace the old value if the new length is smaller
		 * than the old one. Otherwise we will allocate new space in the
		 * bucket to store it.
		 */
		xe = xs->here;
		if (ocfs2_xattr_is_local(xe))
			old = OCFS2_XATTR_SIZE(le64_to_cpu(xe->xe_value_size));
		else
			old = OCFS2_XATTR_SIZE(OCFS2_XATTR_ROOT_SIZE);

		if (old >= value_size)
			need = 0;
	}

	free = xh_free_start - header_size;
	/*
	 * We need to make sure the new name/value pair
	 * can exist in the same block.
	 */
	if (xh_free_start % blocksize < need)
		free -= xh_free_start % blocksize;

	mlog(0, "xs->not_found = %d, in xattr bucket %llu: free = %d, "
	     "need = %d, max_free = %d, xh_free_start = %u, xh_name_value_len ="
	     " %u\n", xs->not_found,
	     (unsigned long long)xs->bucket.bhs[0]->b_blocknr,
	     free, need, max_free, le16_to_cpu(xh->xh_free_start),
	     le16_to_cpu(xh->xh_name_value_len));

	if (free < need || count == ocfs2_xattr_max_xe_in_bucket(inode->i_sb)) {
		if (need <= max_free &&
		    count < ocfs2_xattr_max_xe_in_bucket(inode->i_sb)) {
			/*
			 * We can create the space by defragment. Since only the
			 * name/value will be moved, the xe shouldn't be changed
			 * in xs.
			 */
			ret = ocfs2_defrag_xattr_bucket(inode, &xs->bucket);
			if (ret) {
				mlog_errno(ret);
				goto out;
			}

			xh_free_start = le16_to_cpu(xh->xh_free_start);
			free = xh_free_start - header_size;
			if (xh_free_start % blocksize < need)
				free -= xh_free_start % blocksize;

			if (free >= need)
				goto xattr_set;

			mlog(0, "Can't get enough space for xattr insert by "
			     "defragment. Need %u bytes, but we have %d, so "
			     "allocate new bucket for it.\n", need, free);
		}

		/*
		 * We have to add new buckets or clusters and one
		 * allocation should leave us enough space for insert.
		 */
		BUG_ON(allocation);

		/*
		 * We do not allow for overlapping ranges between buckets. And
		 * the maximum number of collisions we will allow for then is
		 * one bucket's worth, so check it here whether we need to
		 * add a new bucket for the insert.
		 */
		ret = ocfs2_check_xattr_bucket_collision(inode, &xs->bucket);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		ret = ocfs2_add_new_xattr_bucket(inode,
						 xs->xattr_bh,
						 xs->bucket.bhs[0]);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		for (i = 0; i < blk_per_bucket; i++)
			brelse(xs->bucket.bhs[i]);

		memset(&xs->bucket, 0, sizeof(xs->bucket));

		ret = ocfs2_xattr_index_block_find(inode, xs->xattr_bh,
						   xi->name_index,
						   xi->name, xs);
		if (ret && ret != -ENODATA)
			goto out;
		xs->not_found = ret;
		allocation = 1;
		goto try_again;
	}

xattr_set:
	ret = ocfs2_xattr_set_in_bucket(inode, xi, xs);
out:
	mlog_exit(ret);
	return ret;
}

static int ocfs2_delete_xattr_in_bucket(struct inode *inode,
					struct ocfs2_xattr_bucket *bucket,
					void *para)
{
	int ret = 0;
	struct ocfs2_xattr_header *xh = bucket->xh;
	u16 i;
	struct ocfs2_xattr_entry *xe;

	for (i = 0; i < le16_to_cpu(xh->xh_count); i++) {
		xe = &xh->xh_entries[i];
		if (ocfs2_xattr_is_local(xe))
			continue;

		ret = ocfs2_xattr_bucket_value_truncate(inode,
							bucket->bhs[0],
							i, 0);
		if (ret) {
			mlog_errno(ret);
			break;
		}
	}

	return ret;
}

static int ocfs2_delete_xattr_index_block(struct inode *inode,
					  struct buffer_head *xb_bh)
{
	struct ocfs2_xattr_block *xb =
			(struct ocfs2_xattr_block *)xb_bh->b_data;
	struct ocfs2_extent_list *el = &xb->xb_attrs.xb_root.xt_list;
	int ret = 0;
	u32 name_hash = UINT_MAX, e_cpos, num_clusters;
	u64 p_blkno;

	if (le16_to_cpu(el->l_next_free_rec) == 0)
		return 0;

	while (name_hash > 0) {
		ret = ocfs2_xattr_get_rec(inode, name_hash, &p_blkno,
					  &e_cpos, &num_clusters, el);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		ret = ocfs2_iterate_xattr_buckets(inode, p_blkno, num_clusters,
						  ocfs2_delete_xattr_in_bucket,
						  NULL);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		ret = ocfs2_rm_xattr_cluster(inode, xb_bh,
					     p_blkno, e_cpos, num_clusters);
		if (ret) {
			mlog_errno(ret);
			break;
		}

		if (e_cpos == 0)
			break;

		name_hash = e_cpos - 1;
	}

out:
	return ret;
}

/*
 * 'trusted' attributes support
 */

#define XATTR_TRUSTED_PREFIX "trusted."

static size_t ocfs2_xattr_trusted_list(struct inode *inode, char *list,
				       size_t list_size, const char *name,
				       size_t name_len)
{
	const size_t prefix_len = sizeof(XATTR_TRUSTED_PREFIX) - 1;
	const size_t total_len = prefix_len + name_len + 1;

	if (list && total_len <= list_size) {
		memcpy(list, XATTR_TRUSTED_PREFIX, prefix_len);
		memcpy(list + prefix_len, name, name_len);
		list[prefix_len + name_len] = '\0';
	}
	return total_len;
}

static int ocfs2_xattr_trusted_get(struct inode *inode, const char *name,
				   void *buffer, size_t size)
{
	if (strcmp(name, "") == 0)
		return -EINVAL;
	return ocfs2_xattr_get(inode, OCFS2_XATTR_INDEX_TRUSTED, name,
			       buffer, size);
}

static int ocfs2_xattr_trusted_set(struct inode *inode, const char *name,
				   const void *value, size_t size, int flags)
{
	if (strcmp(name, "") == 0)
		return -EINVAL;

	return ocfs2_xattr_set(inode, OCFS2_XATTR_INDEX_TRUSTED, name, value,
			       size, flags);
}

struct xattr_handler ocfs2_xattr_trusted_handler = {
	.prefix	= XATTR_TRUSTED_PREFIX,
	.list	= ocfs2_xattr_trusted_list,
	.get	= ocfs2_xattr_trusted_get,
	.set	= ocfs2_xattr_trusted_set,
};


/*
 * 'user' attributes support
 */

#define XATTR_USER_PREFIX "user."

static size_t ocfs2_xattr_user_list(struct inode *inode, char *list,
				    size_t list_size, const char *name,
				    size_t name_len)
{
	const size_t prefix_len = sizeof(XATTR_USER_PREFIX) - 1;
	const size_t total_len = prefix_len + name_len + 1;
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);

	if (osb->s_mount_opt & OCFS2_MOUNT_NOUSERXATTR)
		return 0;

	if (list && total_len <= list_size) {
		memcpy(list, XATTR_USER_PREFIX, prefix_len);
		memcpy(list + prefix_len, name, name_len);
		list[prefix_len + name_len] = '\0';
	}
	return total_len;
}

static int ocfs2_xattr_user_get(struct inode *inode, const char *name,
				void *buffer, size_t size)
{
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);

	if (strcmp(name, "") == 0)
		return -EINVAL;
	if (osb->s_mount_opt & OCFS2_MOUNT_NOUSERXATTR)
		return -EOPNOTSUPP;
	return ocfs2_xattr_get(inode, OCFS2_XATTR_INDEX_USER, name,
			       buffer, size);
}

static int ocfs2_xattr_user_set(struct inode *inode, const char *name,
				const void *value, size_t size, int flags)
{
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);

	if (strcmp(name, "") == 0)
		return -EINVAL;
	if (osb->s_mount_opt & OCFS2_MOUNT_NOUSERXATTR)
		return -EOPNOTSUPP;

	return ocfs2_xattr_set(inode, OCFS2_XATTR_INDEX_USER, name, value,
			       size, flags);
}

struct xattr_handler ocfs2_xattr_user_handler = {
	.prefix	= XATTR_USER_PREFIX,
	.list	= ocfs2_xattr_user_list,
	.get	= ocfs2_xattr_user_get,
	.set	= ocfs2_xattr_user_set,
};