diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 2d41cb25266b..f9a078661ebc 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -3263,6 +3263,7 @@ int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
 			     struct btrfs_root *root,
 			     struct btrfs_path *path, u64 objectid,
 			     u64 bytenr, int mod);
+u64 btrfs_file_extent_length(struct btrfs_path *path);
 int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
 			   struct btrfs_root *root,
 			   struct btrfs_ordered_sum *sums);
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index 1ad08e4e4a15..bd38cef42358 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -133,7 +133,6 @@ fail:
 	return ERR_PTR(ret);
 }
 
-
 int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
 			     struct btrfs_root *root,
 			     struct btrfs_path *path, u64 objectid,
@@ -151,6 +150,26 @@ int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
 	return ret;
 }
 
+u64 btrfs_file_extent_length(struct btrfs_path *path)
+{
+	int extent_type;
+	struct btrfs_file_extent_item *fi;
+	u64 len;
+
+	fi = btrfs_item_ptr(path->nodes[0], path->slots[0],
+			    struct btrfs_file_extent_item);
+	extent_type = btrfs_file_extent_type(path->nodes[0], fi);
+
+	if (extent_type == BTRFS_FILE_EXTENT_REG ||
+	    extent_type == BTRFS_FILE_EXTENT_PREALLOC)
+		len = btrfs_file_extent_num_bytes(path->nodes[0], fi);
+	else if (extent_type == BTRFS_FILE_EXTENT_INLINE)
+		len = btrfs_file_extent_inline_len(path->nodes[0], fi);
+	else
+		BUG();
+
+	return len;
+}
 
 static int __btrfs_lookup_bio_sums(struct btrfs_root *root,
 				   struct inode *inode, struct bio *bio,
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 4ec41ecb4d65..bcf0e48b1932 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -3143,7 +3143,6 @@ static int log_one_extent(struct btrfs_trans_handle *trans,
 			  struct btrfs_path *dst_path, struct log_args *args)
 {
 	struct btrfs_root *log = root->log_root;
-	struct btrfs_file_extent_item *fi;
 	struct btrfs_key key;
 	u64 start = em->mod_start;
 	u64 search_start = start;
@@ -3199,10 +3198,7 @@ again:
 				}
 			} while (key.offset > start);
 
-			fi = btrfs_item_ptr(path->nodes[0], path->slots[0],
-					    struct btrfs_file_extent_item);
-			num_bytes = btrfs_file_extent_num_bytes(path->nodes[0],
-								fi);
+			num_bytes = btrfs_file_extent_length(path);
 			if (key.offset + num_bytes <= start) {
 				btrfs_release_path(path);
 				return -ENOENT;
@@ -3211,8 +3207,7 @@ again:
 		args->src = path->nodes[0];
 next_slot:
 		btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
-		fi = btrfs_item_ptr(args->src, path->slots[0],
-				    struct btrfs_file_extent_item);
+		num_bytes = btrfs_file_extent_length(path);
 		if (args->nr &&
 		    args->start_slot + args->nr == path->slots[0]) {
 			args->nr++;
@@ -3230,7 +3225,6 @@ next_slot:
 		}
 		nritems = btrfs_header_nritems(path->nodes[0]);
 		path->slots[0]++;
-		num_bytes = btrfs_file_extent_num_bytes(args->src, fi);
 		if (len < num_bytes) {
 			/* I _think_ this is ok, envision we write to a
 			 * preallocated space that is adjacent to a previously