3 files changed, 89 insertions, 4 deletions

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 6df921f218f..0f34cae0a63 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -5602,15 +5602,18 @@ static void btrfs_endio_direct_write(struct bio *bio, int err)
 	struct btrfs_trans_handle *trans;
 	struct btrfs_ordered_extent *ordered = NULL;
 	struct extent_state *cached_state = NULL;
+	u64 ordered_offset = dip->logical_offset;
+	u64 ordered_bytes = dip->bytes;
 	int ret;
 
 	if (err)
 		goto out_done;
-
-	ret = btrfs_dec_test_ordered_pending(inode, &ordered,
-					     dip->logical_offset, dip->bytes);
+again:
+	ret = btrfs_dec_test_first_ordered_pending(inode, &ordered,
+						   &ordered_offset,
+						   ordered_bytes);
 	if (!ret)
-		goto out_done;
+		goto out_test;
 
 	BUG_ON(!ordered);
 
@@ -5670,8 +5673,20 @@ out_unlock:
 out:
 	btrfs_delalloc_release_metadata(inode, ordered->len);
 	btrfs_end_transaction(trans, root);
+	ordered_offset = ordered->file_offset + ordered->len;
 	btrfs_put_ordered_extent(ordered);
 	btrfs_put_ordered_extent(ordered);
+
+out_test:
+	/*
+	 * our bio might span multiple ordered extents.  If we haven't
+	 * completed the accounting for the whole dio, go back and try again
+	 */
+	if (ordered_offset < dip->logical_offset + dip->bytes) {
+		ordered_bytes = dip->logical_offset + dip->bytes -
+			ordered_offset;
+		goto again;
+	}
 out_done:
 	bio->bi_private = dip->private;
 
diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c
index f4621f6deca..ae7737e352c 100644
--- a/fs/btrfs/ordered-data.c
+++ b/fs/btrfs/ordered-data.c
@@ -250,6 +250,73 @@ int btrfs_add_ordered_sum(struct inode *inode,
 
 /*
  * this is used to account for finished IO across a given range
+ * of the file.  The IO may span ordered extents.  If
+ * a given ordered_extent is completely done, 1 is returned, otherwise
+ * 0.
+ *
+ * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
+ * to make sure this function only returns 1 once for a given ordered extent.
+ *
+ * file_offset is updated to one byte past the range that is recorded as
+ * complete.  This allows you to walk forward in the file.
+ */
+int btrfs_dec_test_first_ordered_pending(struct inode *inode,
+				   struct btrfs_ordered_extent **cached,
+				   u64 *file_offset, u64 io_size)
+{
+	struct btrfs_ordered_inode_tree *tree;
+	struct rb_node *node;
+	struct btrfs_ordered_extent *entry = NULL;
+	int ret;
+	u64 dec_end;
+	u64 dec_start;
+	u64 to_dec;
+
+	tree = &BTRFS_I(inode)->ordered_tree;
+	spin_lock(&tree->lock);
+	node = tree_search(tree, *file_offset);
+	if (!node) {
+		ret = 1;
+		goto out;
+	}
+
+	entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
+	if (!offset_in_entry(entry, *file_offset)) {
+		ret = 1;
+		goto out;
+	}
+
+	dec_start = max(*file_offset, entry->file_offset);
+	dec_end = min(*file_offset + io_size, entry->file_offset +
+		      entry->len);
+	*file_offset = dec_end;
+	if (dec_start > dec_end) {
+		printk(KERN_CRIT "bad ordering dec_start %llu end %llu\n",
+		       (unsigned long long)dec_start,
+		       (unsigned long long)dec_end);
+	}
+	to_dec = dec_end - dec_start;
+	if (to_dec > entry->bytes_left) {
+		printk(KERN_CRIT "bad ordered accounting left %llu size %llu\n",
+		       (unsigned long long)entry->bytes_left,
+		       (unsigned long long)to_dec);
+	}
+	entry->bytes_left -= to_dec;
+	if (entry->bytes_left == 0)
+		ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
+	else
+		ret = 1;
+out:
+	if (!ret && cached && entry) {
+		*cached = entry;
+		atomic_inc(&entry->refs);
+	}
+	spin_unlock(&tree->lock);
+	return ret == 0;
+}
+
+/*
+ * this is used to account for finished IO across a given range
  * of the file.  The IO should not span ordered extents.  If
  * a given ordered_extent is completely done, 1 is returned, otherwise
  * 0.
diff --git a/fs/btrfs/ordered-data.h b/fs/btrfs/ordered-data.h
index 8ac365492a3..61dca83119d 100644
--- a/fs/btrfs/ordered-data.h
+++ b/fs/btrfs/ordered-data.h
@@ -141,6 +141,9 @@ int btrfs_remove_ordered_extent(struct inode *inode,
 int btrfs_dec_test_ordered_pending(struct inode *inode,
 				   struct btrfs_ordered_extent **cached,
 				   u64 file_offset, u64 io_size);
+int btrfs_dec_test_first_ordered_pending(struct inode *inode,
+				   struct btrfs_ordered_extent **cached,
+				   u64 *file_offset, u64 io_size);
 int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
 			     u64 start, u64 len, u64 disk_len, int type);
 int btrfs_add_ordered_extent_dio(struct inode *inode, u64 file_offset,