ocfs2: Dirty the entire first bucket in ocfs2_extend_xattr_bucket()

ocfs2_extend_xattr_bucket() takes an extent of buckets and shifts some
of them down to make room for a new xattr.  It is passed the first bh of
the first bucket, because that is where we store the number of buckets
in the extent.

However, future code wants to always dirty the entire bucket when it
is changed.  So let's pass the entire bucket into this function, skip
any block reads (we have them), and add the access/dirty logic.  We also
can skip passing in the target bucket bh - we only need its block
number.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>

fs/ocfs2/xattr.c

@@ -3905,7 +3905,7 @@ static int ocfs2_cp_xattr_bucket(struct inode *inode,
 		mlog_errno(ret);
 		goto out;
 	}
-  
+
 	ret = ocfs2_read_xattr_bucket(s_bucket, s_blkno);
 	if (ret)
 		goto out;
@@ -4232,65 +4232,73 @@ static int ocfs2_add_new_xattr_cluster(struct inode *inode,
 }
 
 /*
- * 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.
+ * We are given an extent.  'first' is the bucket at the very front of
+ * the extent.  The extent has space for an additional bucket past
+ * bucket_xh(first)->xh_num_buckets.  'target_blkno' is the block number
+ * of the target bucket.  We wish to shift every bucket past the target
+ * down one, filling in that additional space.  When we get back to the
+ * target, we split the target between itself and the now-empty bucket
+ * at target+1 (aka, target_blkno + blks_per_bucket).
  */
 static int ocfs2_extend_xattr_bucket(struct inode *inode,
 				     handle_t *handle,
-				     struct buffer_head *first_bh,
-				     struct buffer_head *start_bh,
+				     struct ocfs2_xattr_bucket *first,
+				     u64 target_blk,
 				     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);
-	struct ocfs2_xattr_header *first_xh =
-				(struct ocfs2_xattr_header *)first_bh->b_data;
-	u16 bucket = le16_to_cpu(first_xh->xh_num_buckets);
+	u64 end_blk;
+	u16 new_bucket = le16_to_cpu(bucket_xh(first)->xh_num_buckets);
 
 	mlog(0, "extend xattr bucket in %llu, xattr extend rec starting "
-	     "from %llu, len = %u\n", (unsigned long long)start_blk,
-	     (unsigned long long)first_bh->b_blocknr, num_clusters);
+	     "from %llu, len = %u\n", (unsigned long long)target_blk,
+	     (unsigned long long)bucket_blkno(first), num_clusters);
 
-	BUG_ON(bucket >= num_buckets);
+	/* The extent must have room for an additional bucket */
+	BUG_ON(new_bucket >=
+	       (num_clusters * ocfs2_xattr_buckets_per_cluster(osb)));
 
-	end_blk = first_bh->b_blocknr + (bucket - 1) * blk_per_bucket;
+	/* end_blk points to the last existing bucket */
+	end_blk = bucket_blkno(first) + ((new_bucket - 1) * blk_per_bucket);
 
 	/*
-	 * We will touch all the buckets after the start_bh(include it).
-	 * Then we add one more bucket.
+	 * end_blk is the start of the last existing bucket.
+	 * Thus, (end_blk - target_blk) covers the target bucket and
+	 * every bucket after it up to, but not including, the last
+	 * existing bucket.  Then we add the last existing bucket, the
+	 * new bucket, and the first bucket (3 * blk_per_bucket).
 	 */
-	credits = end_blk - start_blk + 3 * blk_per_bucket + 1 +
+	credits = (end_blk - target_blk) + (3 * blk_per_bucket) +
 		  handle->h_buffer_credits;
 	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);
+	ret = ocfs2_xattr_bucket_journal_access(handle, first,
+						OCFS2_JOURNAL_ACCESS_WRITE);
 	if (ret) {
 		mlog_errno(ret);
 		goto out;
 	}
 
-	while (end_blk != start_blk) {
+	while (end_blk != target_blk) {
 		ret = ocfs2_cp_xattr_bucket(inode, handle, end_blk,
 					    end_blk + blk_per_bucket, 0);
 		if (ret)
 			goto out;
 		end_blk -= blk_per_bucket;
 	}
 
-	/* Move half of the xattr in start_blk to the next bucket. */
-	ret = ocfs2_divide_xattr_bucket(inode, handle, start_blk,
-					start_blk + blk_per_bucket, NULL, 0);
+	/* Move half of the xattr in target_blkno to the next bucket. */
+	ret = ocfs2_divide_xattr_bucket(inode, handle, target_blk,
+					target_blk + blk_per_bucket, NULL, 0);
 
-	le16_add_cpu(&first_xh->xh_num_buckets, 1);
-	ocfs2_journal_dirty(handle, first_bh);
+	le16_add_cpu(&bucket_xh(first)->xh_num_buckets, 1);
+	ocfs2_xattr_bucket_journal_dirty(handle, first);
 
 out:
 	return ret;
@@ -4324,10 +4332,19 @@ static int ocfs2_add_new_xattr_bucket(struct inode *inode,
 	int ret, num_buckets, extend = 1;
 	u64 p_blkno;
 	u32 e_cpos, num_clusters;
+	/* The bucket at the front of the extent */
+	struct ocfs2_xattr_bucket *first;
 
 	mlog(0, "Add new xattr bucket starting form %llu\n",
 	     (unsigned long long)header_bh->b_blocknr);
 
+	first = ocfs2_xattr_bucket_new(inode);
+	if (!first) {
+		ret = -ENOMEM;
+		mlog_errno(ret);
+		goto out;
+	}
+
 	/*
 	 * Add refrence for header_bh here because it may be
 	 * changed in ocfs2_add_new_xattr_cluster and we need
@@ -4367,17 +4384,25 @@ static int ocfs2_add_new_xattr_bucket(struct inode *inode,
 		}
 	}
 
-	if (extend)
+	if (extend) {
+		/* These bucket reads should be cached */
+		ret = ocfs2_read_xattr_bucket(first, first_bh->b_blocknr);
+		if (ret) {
+			mlog_errno(ret);
+			goto out;
+		}
 		ret = ocfs2_extend_xattr_bucket(inode,
 						ctxt->handle,
-						first_bh,
-						header_bh,
+						first, header_bh->b_blocknr,
 						num_clusters);
-	if (ret)
-		mlog_errno(ret);
+		if (ret)
+			mlog_errno(ret);
+	}
+
 out:
 	brelse(first_bh);
 	brelse(header_bh);
+	ocfs2_xattr_bucket_free(first);
 	return ret;
 }