Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 492a8a33 authored by Tao Ma's avatar Tao Ma Committed by Joel Becker
Browse files

ocfs2: Add CoW support for xattr.



In order to make 2 transcation(xattr and cow) independent with each other,
we CoW the whole xattr out in case we are setting them.

Signed-off-by: default avatarTao Ma <tao.ma@oracle.com>
parent 913580b4
Loading
Loading
Loading
Loading
+243 −3
Original line number Diff line number Diff line
@@ -32,6 +32,7 @@
#include "dlmglue.h"
#include "extent_map.h"
#include "aops.h"
#include "xattr.h"

#include <linux/bio.h>
#include <linux/blkdev.h>
@@ -51,6 +52,9 @@ struct ocfs2_cow_context {
	struct ocfs2_alloc_context *meta_ac;
	struct ocfs2_alloc_context *data_ac;
	struct ocfs2_cached_dealloc_ctxt dealloc;
	void *cow_object;
	struct ocfs2_post_refcount *post_refcount;
	int extra_credits;
	int (*get_clusters)(struct ocfs2_cow_context *context,
			    u32 v_cluster, u32 *p_cluster,
			    u32 *num_clusters,
@@ -2848,6 +2852,65 @@ unlock:
	return ret;
}

static int ocfs2_duplicate_clusters_by_jbd(handle_t *handle,
					   struct ocfs2_cow_context *context,
					   u32 cpos, u32 old_cluster,
					   u32 new_cluster, u32 new_len)
{
	int ret = 0;
	struct super_block *sb = context->inode->i_sb;
	struct ocfs2_caching_info *ci = context->data_et.et_ci;
	int i, blocks = ocfs2_clusters_to_blocks(sb, new_len);
	u64 old_block = ocfs2_clusters_to_blocks(sb, old_cluster);
	u64 new_block = ocfs2_clusters_to_blocks(sb, new_cluster);
	struct ocfs2_super *osb = OCFS2_SB(sb);
	struct buffer_head *old_bh = NULL;
	struct buffer_head *new_bh = NULL;

	mlog(0, "old_cluster %u, new %u, len %u\n", old_cluster,
	     new_cluster, new_len);

	for (i = 0; i < blocks; i++, old_block++, new_block++) {
		new_bh = sb_getblk(osb->sb, new_block);
		if (new_bh == NULL) {
			ret = -EIO;
			mlog_errno(ret);
			break;
		}

		ocfs2_set_new_buffer_uptodate(ci, new_bh);

		ret = ocfs2_read_block(ci, old_block, &old_bh, NULL);
		if (ret) {
			mlog_errno(ret);
			break;
		}

		ret = ocfs2_journal_access(handle, ci, new_bh,
					   OCFS2_JOURNAL_ACCESS_CREATE);
		if (ret) {
			mlog_errno(ret);
			break;
		}

		memcpy(new_bh->b_data, old_bh->b_data, sb->s_blocksize);
		ret = ocfs2_journal_dirty(handle, new_bh);
		if (ret) {
			mlog_errno(ret);
			break;
		}

		brelse(new_bh);
		brelse(old_bh);
		new_bh = NULL;
		old_bh = NULL;
	}

	brelse(new_bh);
	brelse(old_bh);
	return ret;
}

static int ocfs2_clear_ext_refcount(handle_t *handle,
				    struct ocfs2_extent_tree *et,
				    u32 cpos, u32 p_cluster, u32 len,
@@ -3026,6 +3089,10 @@ static int ocfs2_make_clusters_writable(struct super_block *sb,
		return ret;
	}

	if (context->post_refcount)
		credits += context->post_refcount->credits;

	credits += context->extra_credits;
	handle = ocfs2_start_trans(osb, credits);
	if (IS_ERR(handle)) {
		ret = PTR_ERR(handle);
@@ -3105,13 +3172,25 @@ static int ocfs2_make_clusters_writable(struct super_block *sb,
		ref_leaf_bh = NULL;
	}

	/* handle any post_cow action. */
	if (context->post_refcount && context->post_refcount->func) {
		ret = context->post_refcount->func(context->inode, handle,
						context->post_refcount->para);
		if (ret) {
			mlog_errno(ret);
			goto out_commit;
		}
	}

	/*
	 * Here we should write the new page out first if we are
	 * in write-back mode.
	 */
	if (context->get_clusters == ocfs2_di_get_clusters) {
		ret = ocfs2_cow_sync_writeback(sb, context, cpos, num_clusters);
		if (ret)
			mlog_errno(ret);
	}

out_commit:
	ocfs2_commit_trans(osb, handle);
@@ -3298,6 +3377,167 @@ int ocfs2_refcount_cow(struct inode *inode,
	return ret;
}

static int ocfs2_xattr_value_get_clusters(struct ocfs2_cow_context *context,
					  u32 v_cluster, u32 *p_cluster,
					  u32 *num_clusters,
					  unsigned int *extent_flags)
{
	struct inode *inode = context->inode;
	struct ocfs2_xattr_value_root *xv = context->cow_object;

	return ocfs2_xattr_get_clusters(inode, v_cluster, p_cluster,
					num_clusters, &xv->xr_list,
					extent_flags);
}

/*
 * Given a xattr value root, calculate the most meta/credits we need for
 * refcount tree change if we truncate it to 0.
 */
int ocfs2_refcounted_xattr_delete_need(struct inode *inode,
				       struct ocfs2_caching_info *ref_ci,
				       struct buffer_head *ref_root_bh,
				       struct ocfs2_xattr_value_root *xv,
				       int *meta_add, int *credits)
{
	int ret = 0, index, ref_blocks = 0;
	u32 p_cluster, num_clusters;
	u32 cpos = 0, clusters = le32_to_cpu(xv->xr_clusters);
	struct ocfs2_refcount_block *rb;
	struct ocfs2_refcount_rec rec;
	struct buffer_head *ref_leaf_bh = NULL;

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

		cpos += num_clusters;

		while (num_clusters) {
			ret = ocfs2_get_refcount_rec(ref_ci, ref_root_bh,
						     p_cluster, num_clusters,
						     &rec, &index,
						     &ref_leaf_bh);
			if (ret) {
				mlog_errno(ret);
				goto out;
			}

			BUG_ON(!rec.r_refcount);

			rb = (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;

			/*
			 * We really don't know whether the other clusters is in
			 * this refcount block or not, so just take the worst
			 * case that all the clusters are in this block and each
			 * one will split a refcount rec, so totally we need
			 * clusters * 2 new refcount rec.
			 */
			if (le64_to_cpu(rb->rf_records.rl_used) + clusters * 2 >
			    le16_to_cpu(rb->rf_records.rl_count))
				ref_blocks++;

			*credits += 1;
			brelse(ref_leaf_bh);
			ref_leaf_bh = NULL;

			if (num_clusters <= le32_to_cpu(rec.r_clusters))
				break;
			else
				num_clusters -= le32_to_cpu(rec.r_clusters);
			p_cluster += num_clusters;
		}
	}

	*meta_add += ref_blocks;
	if (!ref_blocks)
		goto out;

	rb = (struct ocfs2_refcount_block *)ref_root_bh->b_data;
	if (le32_to_cpu(rb->rf_flags) & OCFS2_REFCOUNT_TREE_FL)
		*credits += OCFS2_EXPAND_REFCOUNT_TREE_CREDITS;
	else {
		struct ocfs2_extent_tree et;

		ocfs2_init_refcount_extent_tree(&et, ref_ci, ref_root_bh);
		*credits += ocfs2_calc_extend_credits(inode->i_sb,
						      et.et_root_el,
						      ref_blocks);
	}

out:
	brelse(ref_leaf_bh);
	return ret;
}

/*
 * Do CoW for xattr.
 */
int ocfs2_refcount_cow_xattr(struct inode *inode,
			     struct ocfs2_dinode *di,
			     struct ocfs2_xattr_value_buf *vb,
			     struct ocfs2_refcount_tree *ref_tree,
			     struct buffer_head *ref_root_bh,
			     u32 cpos, u32 write_len,
			     struct ocfs2_post_refcount *post)
{
	int ret;
	struct ocfs2_xattr_value_root *xv = vb->vb_xv;
	struct ocfs2_inode_info *oi = OCFS2_I(inode);
	struct ocfs2_cow_context *context = NULL;
	u32 cow_start, cow_len;

	BUG_ON(!(oi->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL));

	ret = ocfs2_refcount_cal_cow_clusters(inode, &xv->xr_list,
					      cpos, write_len, UINT_MAX,
					      &cow_start, &cow_len);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	BUG_ON(cow_len == 0);

	context = kzalloc(sizeof(struct ocfs2_cow_context), GFP_NOFS);
	if (!context) {
		ret = -ENOMEM;
		mlog_errno(ret);
		goto out;
	}

	context->inode = inode;
	context->cow_start = cow_start;
	context->cow_len = cow_len;
	context->ref_tree = ref_tree;
	context->ref_root_bh = ref_root_bh;;
	context->cow_object = xv;

	context->cow_duplicate_clusters = ocfs2_duplicate_clusters_by_jbd;
	/* We need the extra credits for duplicate_clusters by jbd. */
	context->extra_credits =
		ocfs2_clusters_to_blocks(inode->i_sb, 1) * cow_len;
	context->get_clusters = ocfs2_xattr_value_get_clusters;
	context->post_refcount = post;

	ocfs2_init_xattr_value_extent_tree(&context->data_et,
					   INODE_CACHE(inode), vb);

	ret = ocfs2_replace_cow(context);
	if (ret)
		mlog_errno(ret);

out:
	kfree(context);
	return ret;
}

/*
 * Insert a new extent into refcount tree and mark a extent rec
 * as refcounted in the dinode tree.
+29 −0
Original line number Diff line number Diff line
@@ -54,4 +54,33 @@ int ocfs2_prepare_refcount_change_for_del(struct inode *inode,
					  struct ocfs2_alloc_context **meta_ac);
int ocfs2_refcount_cow(struct inode *inode, struct buffer_head *di_bh,
		       u32 cpos, u32 write_len, u32 max_cpos);

typedef int (ocfs2_post_refcount_func)(struct inode *inode,
				       handle_t *handle,
				       void *para);
/*
 * Some refcount caller need to do more work after we modify the data b-tree
 * during refcount operation(including CoW and add refcount flag), and make the
 * transaction complete. So it must give us this structure so that we can do it
 * within our transaction.
 *
 */
struct ocfs2_post_refcount {
	int credits;			/* credits it need for journal. */
	ocfs2_post_refcount_func *func;	/* real function. */
	void *para;
};

int ocfs2_refcounted_xattr_delete_need(struct inode *inode,
				       struct ocfs2_caching_info *ref_ci,
				       struct buffer_head *ref_root_bh,
				       struct ocfs2_xattr_value_root *xv,
				       int *meta_add, int *credits);
int ocfs2_refcount_cow_xattr(struct inode *inode,
			     struct ocfs2_dinode *di,
			     struct ocfs2_xattr_value_buf *vb,
			     struct ocfs2_refcount_tree *ref_tree,
			     struct buffer_head *ref_root_bh,
			     u32 cpos, u32 write_len,
			     struct ocfs2_post_refcount *post);
#endif /* OCFS2_REFCOUNTTREE_H */
+222 −12
Original line number Diff line number Diff line
@@ -55,7 +55,7 @@
#include "buffer_head_io.h"
#include "super.h"
#include "xattr.h"

#include "refcounttree.h"

struct ocfs2_xattr_def_value_root {
	struct ocfs2_xattr_value_root	xv;
@@ -176,6 +176,14 @@ static int ocfs2_mv_xattr_buckets(struct inode *inode, handle_t *handle,
				  u64 src_blk, u64 last_blk, u64 to_blk,
				  unsigned int start_bucket,
				  u32 *first_hash);
static int ocfs2_prepare_refcount_xattr(struct inode *inode,
					struct ocfs2_dinode *di,
					struct ocfs2_xattr_info *xi,
					struct ocfs2_xattr_search *xis,
					struct ocfs2_xattr_search *xbs,
					struct ocfs2_refcount_tree **ref_tree,
					int *meta_need,
					int *credits);

static inline u16 ocfs2_xattr_buckets_per_cluster(struct ocfs2_super *osb)
{
@@ -647,6 +655,7 @@ leave:
static int __ocfs2_remove_xattr_range(struct inode *inode,
				      struct ocfs2_xattr_value_buf *vb,
				      u32 cpos, u32 phys_cpos, u32 len,
				      unsigned int ext_flags,
				      struct ocfs2_xattr_set_ctxt *ctxt)
{
	int ret;
@@ -678,7 +687,14 @@ static int __ocfs2_remove_xattr_range(struct inode *inode,
		goto out;
	}

	ret = ocfs2_cache_cluster_dealloc(&ctxt->dealloc, phys_blkno, len);
	if (ext_flags & OCFS2_EXT_REFCOUNTED)
		ret = ocfs2_decrease_refcount(inode, handle,
					ocfs2_blocks_to_clusters(inode->i_sb,
								 phys_blkno),
					len, ctxt->meta_ac, &ctxt->dealloc, 1);
	else
		ret = ocfs2_cache_cluster_dealloc(&ctxt->dealloc,
						  phys_blkno, len);
	if (ret)
		mlog_errno(ret);

@@ -693,6 +709,7 @@ static int ocfs2_xattr_shrink_size(struct inode *inode,
				   struct ocfs2_xattr_set_ctxt *ctxt)
{
	int ret = 0;
	unsigned int ext_flags;
	u32 trunc_len, cpos, phys_cpos, alloc_size;
	u64 block;

@@ -704,7 +721,7 @@ static int ocfs2_xattr_shrink_size(struct inode *inode,
	while (trunc_len) {
		ret = ocfs2_xattr_get_clusters(inode, cpos, &phys_cpos,
					       &alloc_size,
					       &vb->vb_xv->xr_list, NULL);
					       &vb->vb_xv->xr_list, &ext_flags);
		if (ret) {
			mlog_errno(ret);
			goto out;
@@ -715,7 +732,7 @@ static int ocfs2_xattr_shrink_size(struct inode *inode,

		ret = __ocfs2_remove_xattr_range(inode, vb, cpos,
						 phys_cpos, alloc_size,
						 ctxt);
						 ext_flags, ctxt);
		if (ret) {
			mlog_errno(ret);
			goto out;
@@ -1182,7 +1199,7 @@ static int ocfs2_xattr_get(struct inode *inode,

static int __ocfs2_xattr_set_value_outside(struct inode *inode,
					   handle_t *handle,
					   struct ocfs2_xattr_value_root *xv,
					   struct ocfs2_xattr_value_buf *vb,
					   const void *value,
					   int value_len)
{
@@ -1193,18 +1210,22 @@ static int __ocfs2_xattr_set_value_outside(struct inode *inode,
	u32 clusters = ocfs2_clusters_for_bytes(inode->i_sb, value_len);
	u64 blkno;
	struct buffer_head *bh = NULL;
	unsigned int ext_flags;
	struct ocfs2_xattr_value_root *xv = vb->vb_xv;

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

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

		BUG_ON(ext_flags & OCFS2_EXT_REFCOUNTED);

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

		for (i = 0; i < num_clusters * bpc; i++, blkno++) {
@@ -1356,7 +1377,7 @@ static int ocfs2_xattr_set_value_outside(struct inode *inode,
		mlog_errno(ret);
		return ret;
	}
	ret = __ocfs2_xattr_set_value_outside(inode, ctxt->handle, vb->vb_xv,
	ret = __ocfs2_xattr_set_value_outside(inode, ctxt->handle, vb,
					      xi->value, xi->value_len);
	if (ret < 0)
		mlog_errno(ret);
@@ -1595,7 +1616,7 @@ static int ocfs2_xattr_set_entry(struct inode *inode,

				ret = __ocfs2_xattr_set_value_outside(inode,
								handle,
								vb.vb_xv,
								&vb,
								xi->value,
								xi->value_len);
				if (ret < 0)
@@ -2431,6 +2452,7 @@ static int ocfs2_init_xattr_set_ctxt(struct inode *inode,
				     struct ocfs2_xattr_search *xis,
				     struct ocfs2_xattr_search *xbs,
				     struct ocfs2_xattr_set_ctxt *ctxt,
				     int extra_meta,
				     int *credits)
{
	int clusters_add, meta_add, ret;
@@ -2447,6 +2469,7 @@ static int ocfs2_init_xattr_set_ctxt(struct inode *inode,
		return ret;
	}

	meta_add += extra_meta;
	mlog(0, "Set xattr %s, reserve meta blocks = %d, clusters = %d, "
	     "credits = %d\n", xi->name, meta_add, clusters_add, *credits);

@@ -2714,10 +2737,11 @@ int ocfs2_xattr_set(struct inode *inode,
{
	struct buffer_head *di_bh = NULL;
	struct ocfs2_dinode *di;
	int ret, credits;
	int ret, credits, ref_meta = 0, ref_credits = 0;
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
	struct inode *tl_inode = osb->osb_tl_inode;
	struct ocfs2_xattr_set_ctxt ctxt = { NULL, NULL, };
	struct ocfs2_refcount_tree *ref_tree = NULL;

	struct ocfs2_xattr_info xi = {
		.name_index = name_index,
@@ -2782,6 +2806,17 @@ int ocfs2_xattr_set(struct inode *inode,
			goto cleanup;
	}

	/* Check whether the value is refcounted and do some prepartion. */
	if (OCFS2_I(inode)->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL &&
	    (!xis.not_found || !xbs.not_found)) {
		ret = ocfs2_prepare_refcount_xattr(inode, di, &xi,
						   &xis, &xbs, &ref_tree,
						   &ref_meta, &ref_credits);
		if (ret) {
			mlog_errno(ret);
			goto cleanup;
		}
	}

	mutex_lock(&tl_inode->i_mutex);

@@ -2796,7 +2831,7 @@ int ocfs2_xattr_set(struct inode *inode,
	mutex_unlock(&tl_inode->i_mutex);

	ret = ocfs2_init_xattr_set_ctxt(inode, di, &xi, &xis,
					&xbs, &ctxt, &credits);
					&xbs, &ctxt, ref_meta, &credits);
	if (ret) {
		mlog_errno(ret);
		goto cleanup;
@@ -2804,7 +2839,7 @@ int ocfs2_xattr_set(struct inode *inode,

	/* we need to update inode's ctime field, so add credit for it. */
	credits += OCFS2_INODE_UPDATE_CREDITS;
	ctxt.handle = ocfs2_start_trans(osb, credits);
	ctxt.handle = ocfs2_start_trans(osb, credits + ref_credits);
	if (IS_ERR(ctxt.handle)) {
		ret = PTR_ERR(ctxt.handle);
		mlog_errno(ret);
@@ -2823,6 +2858,8 @@ int ocfs2_xattr_set(struct inode *inode,
		ocfs2_schedule_truncate_log_flush(osb, 1);
	ocfs2_run_deallocs(osb, &ctxt.dealloc);
cleanup:
	if (ref_tree)
		ocfs2_unlock_refcount_tree(osb, ref_tree, 1);
	up_write(&OCFS2_I(inode)->ip_xattr_sem);
	ocfs2_inode_unlock(inode, 1);
cleanup_nolock:
@@ -4802,6 +4839,9 @@ static int ocfs2_xattr_bucket_set_value_outside(struct inode *inode,
	struct ocfs2_xattr_entry *xe = xs->here;
	struct ocfs2_xattr_header *xh = bucket_xh(xs->bucket);
	void *base;
	struct ocfs2_xattr_value_buf vb = {
		.vb_access = ocfs2_journal_access,
	};

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

@@ -4818,8 +4858,10 @@ static int ocfs2_xattr_bucket_set_value_outside(struct inode *inode,
	xv = (struct ocfs2_xattr_value_root *)(base + offset +
		 OCFS2_XATTR_SIZE(xe->xe_name_len));

	vb.vb_xv = xv;
	vb.vb_bh = xs->bucket->bu_bhs[block_off];
	ret = __ocfs2_xattr_set_value_outside(inode, handle,
					      xv, val, value_len);
					      &vb, val, value_len);
	if (ret)
		mlog_errno(ret);
out:
@@ -5310,6 +5352,174 @@ out:
	return ret;
}

/*
 * Whenever we modify a xattr value root in the bucket(e.g, CoW
 * or change the extent record flag), we need to recalculate
 * the metaecc for the whole bucket. So it is done here.
 *
 * Note:
 * We have to give the extra credits for the caller.
 */
static int ocfs2_xattr_bucket_post_refcount(struct inode *inode,
					    handle_t *handle,
					    void *para)
{
	int ret;
	struct ocfs2_xattr_bucket *bucket =
			(struct ocfs2_xattr_bucket *)para;

	ret = ocfs2_xattr_bucket_journal_access(handle, bucket,
						OCFS2_JOURNAL_ACCESS_WRITE);
	if (ret) {
		mlog_errno(ret);
		return ret;
	}

	ocfs2_xattr_bucket_journal_dirty(handle, bucket);

	return 0;
}

/*
 * Special action we need if the xattr value is refcounted.
 *
 * 1. If the xattr is refcounted, lock the tree.
 * 2. CoW the xattr if we are setting the new value and the value
 *    will be stored outside.
 * 3. In other case, decrease_refcount will work for us, so just
 *    lock the refcount tree, calculate the meta and credits is OK.
 *
 * We have to do CoW before ocfs2_init_xattr_set_ctxt since
 * currently CoW is a completed transaction, while this function
 * will also lock the allocators and let us deadlock. So we will
 * CoW the whole xattr value.
 */
static int ocfs2_prepare_refcount_xattr(struct inode *inode,
					struct ocfs2_dinode *di,
					struct ocfs2_xattr_info *xi,
					struct ocfs2_xattr_search *xis,
					struct ocfs2_xattr_search *xbs,
					struct ocfs2_refcount_tree **ref_tree,
					int *meta_add,
					int *credits)
{
	int ret = 0;
	struct ocfs2_xattr_block *xb;
	struct ocfs2_xattr_entry *xe;
	char *base;
	u32 p_cluster, num_clusters;
	unsigned int ext_flags;
	int name_offset, name_len;
	struct ocfs2_xattr_value_buf vb;
	struct ocfs2_xattr_bucket *bucket = NULL;
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
	struct ocfs2_post_refcount refcount;
	struct ocfs2_post_refcount *p = NULL;
	struct buffer_head *ref_root_bh = NULL;

	if (!xis->not_found) {
		xe = xis->here;
		name_offset = le16_to_cpu(xe->xe_name_offset);
		name_len = OCFS2_XATTR_SIZE(xe->xe_name_len);
		base = xis->base;
		vb.vb_bh = xis->inode_bh;
		vb.vb_access = ocfs2_journal_access_di;
	} else {
		int i, block_off = 0;
		xb = (struct ocfs2_xattr_block *)xbs->xattr_bh->b_data;
		xe = xbs->here;
		name_offset = le16_to_cpu(xe->xe_name_offset);
		name_len = OCFS2_XATTR_SIZE(xe->xe_name_len);
		i = xbs->here - xbs->header->xh_entries;

		if (le16_to_cpu(xb->xb_flags) & OCFS2_XATTR_INDEXED) {
			ret = ocfs2_xattr_bucket_get_name_value(inode,
							bucket_xh(xbs->bucket),
							i, &block_off,
							&name_offset);
			if (ret) {
				mlog_errno(ret);
				goto out;
			}
			base = bucket_block(xbs->bucket, block_off);
			vb.vb_bh = xbs->bucket->bu_bhs[block_off];
			vb.vb_access = ocfs2_journal_access;

			if (ocfs2_meta_ecc(osb)) {
				/*create parameters for ocfs2_post_refcount. */
				bucket = xbs->bucket;
				refcount.credits = bucket->bu_blocks;
				refcount.para = bucket;
				refcount.func =
					ocfs2_xattr_bucket_post_refcount;
				p = &refcount;
			}
		} else {
			base = xbs->base;
			vb.vb_bh = xbs->xattr_bh;
			vb.vb_access = ocfs2_journal_access_xb;
		}
	}

	if (ocfs2_xattr_is_local(xe))
		goto out;

	vb.vb_xv = (struct ocfs2_xattr_value_root *)
				(base + name_offset + name_len);

	ret = ocfs2_xattr_get_clusters(inode, 0, &p_cluster,
				       &num_clusters, &vb.vb_xv->xr_list,
				       &ext_flags);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	/*
	 * We just need to check the 1st extent record, since we always
	 * CoW the whole xattr. So there shouldn't be a xattr with
	 * some REFCOUNT extent recs after the 1st one.
	 */
	if (!(ext_flags & OCFS2_EXT_REFCOUNTED))
		goto out;

	ret = ocfs2_lock_refcount_tree(osb, le64_to_cpu(di->i_refcount_loc),
				       1, ref_tree, &ref_root_bh);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	/*
	 * If we are deleting the xattr or the new size will be stored inside,
	 * cool, leave it there, the xattr truncate process will remove them
	 * for us(it still needs the refcount tree lock and the meta, credits).
	 * And the worse case is that every cluster truncate will split the
	 * refcount tree, and make the original extent become 3. So we will need
	 * 2 * cluster more extent recs at most.
	 */
	if (!xi->value || xi->value_len <= OCFS2_XATTR_INLINE_SIZE) {

		ret = ocfs2_refcounted_xattr_delete_need(inode,
							 &(*ref_tree)->rf_ci,
							 ref_root_bh, vb.vb_xv,
							 meta_add, credits);
		if (ret)
			mlog_errno(ret);
		goto out;
	}

	ret = ocfs2_refcount_cow_xattr(inode, di, &vb,
				       *ref_tree, ref_root_bh, 0,
				       le32_to_cpu(vb.vb_xv->xr_clusters), p);
	if (ret)
		mlog_errno(ret);

out:
	brelse(ref_root_bh);
	return ret;
}

/*
 * 'security' attributes support
 */