ocfs2: Use buckets in ocfs2_xattr_create_index_block().

Use the ocfs2_xattr_bucket abstraction in
ocfs2_xattr_create_index_block() and its helpers.  We get more efficient
reads, a lot less buffer_head munging, and nicer code to boot.  While
we're at it, ocfs2_xattr_update_xattr_search() becomes void.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>

fs/ocfs2/xattr.c

@@ -2649,32 +2649,34 @@ static void swap_xe(void *a, void *b, int size)
 /*
  * 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.
+ * The header goes at the start of the bucket, and the names+values are
+ * filled from the end.  This is why *target starts as the last buffer.
  * 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)
+					   struct ocfs2_xattr_bucket *bucket)
 {
 	int i, blocksize = inode->i_sb->s_blocksize;
+	int blks = ocfs2_blocks_per_xattr_bucket(inode->i_sb);
 	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;
+	struct ocfs2_xattr_header *xh = bucket_xh(bucket);
 	u16 count = le16_to_cpu(xb_xh->xh_count);
-	char *target = xh_bh->b_data, *src = xb_bh->b_data;
+	char *src = xb_bh->b_data;
+	char *target = bucket_block(bucket, blks - 1);
 
 	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);
+	     (unsigned long long)bucket_blkno(bucket));
+
+	for (i = 0; i < blks; i++)
+		memset(bucket_block(bucket, i), 0, blocksize);
 
-	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
@@ -2686,8 +2688,6 @@ static void ocfs2_cp_xattr_block_to_bucket(struct inode *inode,
 	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. */
@@ -2697,7 +2697,7 @@ static void ocfs2_cp_xattr_block_to_bucket(struct inode *inode,
 	xh->xh_free_start = cpu_to_le16(OCFS2_XATTR_BUCKET_SIZE - size);
 
 	/* copy all the entries. */
-	target = xh_bh->b_data;
+	target = bucket_block(bucket, 0);
 	offset = offsetof(struct ocfs2_xattr_header, xh_entries);
 	size = count * sizeof(struct ocfs2_xattr_entry);
 	memcpy(target + offset, (char *)xb_xh + offset, size);
@@ -2723,42 +2723,24 @@ static void ocfs2_cp_xattr_block_to_bucket(struct inode *inode,
  * 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)
+static void ocfs2_xattr_update_xattr_search(struct inode *inode,
+					    struct ocfs2_xattr_search *xs,
+					    struct buffer_head *old_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);
+	int i;
 
-	xs->bucket->bu_bhs[0] = new_bh;
-	get_bh(new_bh);
 	xs->header = bucket_xh(xs->bucket);
-
-	xs->base = new_bh->b_data;
+	xs->base = bucket_block(xs->bucket, 0);
 	xs->end = xs->base + inode->i_sb->s_blocksize;
 
-	if (!xs->not_found) {
-		if (OCFS2_XATTR_BUCKET_SIZE != blocksize) {
-			ret = ocfs2_read_blocks(inode,
-					bucket_blkno(xs->bucket) + 1,
-					blk_per_bucket - 1, &xs->bucket->bu_bhs[1],
-					0);
-			if (ret) {
-				mlog_errno(ret);
-				return ret;
-			}
-
-		}
-		i = xs->here - old_xh->xh_entries;
-		xs->here = &xs->header->xh_entries[i];
-	}
+	if (xs->not_found)
+		return;
 
-	return ret;
+	i = xs->here - old_xh->xh_entries;
+	xs->here = &xs->header->xh_entries[i];
 }
 
 static int ocfs2_xattr_create_index_block(struct inode *inode,
@@ -2771,18 +2753,17 @@ static int ocfs2_xattr_create_index_block(struct inode *inode,
 	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);
+	BUG_ON(!xs->bucket);
 
 	ret = ocfs2_reserve_clusters(osb, 1, &data_ac);
 	if (ret) {
@@ -2798,10 +2779,10 @@ static int ocfs2_xattr_create_index_block(struct inode *inode,
 	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.
+	 * We need more credits.  One for the xattr block update and one
+	 * for each block of the new xattr bucket.
 	 */
-	credits += 3;
+	credits += 1 + ocfs2_blocks_per_xattr_bucket(inode->i_sb);
 	handle = ocfs2_start_trans(osb, credits);
 	if (IS_ERR(handle)) {
 		ret = PTR_ERR(handle);
@@ -2832,51 +2813,23 @@ static int ocfs2_xattr_create_index_block(struct inode *inode,
 	mlog(0, "allocate 1 cluster from %llu to xattr block\n",
 	     (unsigned long long)blkno);
 
-	xh_bh = sb_getblk(inode->i_sb, blkno);
-	if (!xh_bh) {
-		ret = -EIO;
+	ret = ocfs2_init_xattr_bucket(xs->bucket, blkno);
+	if (ret) {
 		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);
+	ret = ocfs2_xattr_bucket_journal_access(handle, xs->bucket,
+						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_cp_xattr_block_to_bucket(inode, xb_bh, xs->bucket);
+	ocfs2_xattr_bucket_journal_dirty(handle, xs->bucket);
 
-	ret = ocfs2_xattr_update_xattr_search(inode, xs, xb_bh, xh_bh);
-	if (ret) {
-		mlog_errno(ret);
-		goto out_commit;
-	}
+	ocfs2_xattr_update_xattr_search(inode, xs, xb_bh);
 
 	/* Change from ocfs2_xattr_header to ocfs2_xattr_tree_root */
 	memset(&xb->xb_attrs, 0, inode->i_sb->s_blocksize -
@@ -2911,9 +2864,6 @@ out:
 	if (data_ac)
 		ocfs2_free_alloc_context(data_ac);
 
-	brelse(xh_bh);
-	brelse(data_bh);
-
 	return ret;
 }