Re: [PATCH 2/2] btrfs: Don't set SHAREABLE flag for data reloc tree

On Wed, May 13, 2020 at 02:16:11PM +0800, Qu Wenruo wrote:

-	if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
+	if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID &&
+	    root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID) {

 	if (test_bit(BTRFS_ROOT_SHAREABLE, &root->state) ||
-	    root == fs_info->tree_root)
+	    root == fs_info->tree_root || root == fs_info->dreloc_root)

 		if (found_extent &&
 		    (test_bit(BTRFS_ROOT_SHAREABLE, &root->state) ||
-		     root == fs_info->tree_root)) {
+		     root == fs_info->tree_root ||
+		     root == fs_info->dreloc_root)) {

Lots of repeated conditions, though not all of them exactly the same. I
was thinking about adding some helpers but don't have a good suggestion.

The concern is about too much special casing, it's eg tree_root +
data_reloc_tree, or SHAREABLE + tree_reloc + data_reloc, etc. The
helpers should capture the common semantics of the condition and also
reduce the surface for future errors.