btrfs-progs: check: remove old mixed backref code

A code added in 2009 (95d3f20b51e9b) for a very short-lived change in
the format is no concern to us nowadays.

Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/cmds-check.c b/cmds-check.c
index 7ee81d8..7382d33 100644 (file)
--- a/cmds-check.c
+++ b/cmds-check.c
@@ -66,7 +66,6 @@ static u64 total_extent_tree_bytes = 0;
 static u64 btree_space_waste = 0;
 static u64 data_bytes_allocated = 0;
 static u64 data_bytes_referenced = 0;
-static int found_old_backref = 0;
 static LIST_HEAD(duplicate_extents);
 static LIST_HEAD(delete_items);
 static int no_holes = 0;
@@ -7945,11 +7944,6 @@ static int run_next_block(struct btrfs_root *root,
                total_fs_tree_bytes += buf->len;
        if (btrfs_header_owner(buf) == BTRFS_EXTENT_TREE_OBJECTID)
                total_extent_tree_bytes += buf->len;
-       if (!found_old_backref &&
-           btrfs_header_owner(buf) == BTRFS_TREE_RELOC_OBJECTID &&
-           btrfs_header_backref_rev(buf) == BTRFS_MIXED_BACKREF_REV &&
-           !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC))
-               found_old_backref = 1;
 out:
        free_extent_buffer(buf);
        return ret;
@@ -11456,11 +11450,6 @@ static int traverse_tree_block(struct btrfs_root *root,
                total_fs_tree_bytes += node->len;
        if (btrfs_header_owner(node) == BTRFS_EXTENT_TREE_OBJECTID)
                total_extent_tree_bytes += node->len;
-       if (!found_old_backref &&
-           btrfs_header_owner(node) == BTRFS_TREE_RELOC_OBJECTID &&
-           btrfs_header_backref_rev(node) == BTRFS_MIXED_BACKREF_REV &&
-           !btrfs_header_flag(node, BTRFS_HEADER_FLAG_RELOC))
-               found_old_backref = 1;
 
        /* pre-order tranversal, check itself first */
        level = btrfs_header_level(node);
@@ -13150,17 +13139,6 @@ int cmd_check(int argc, char **argv)
                err |= !!ret;
        }
 out:
-       if (found_old_backref) { /*
-                * there was a disk format change when mixed
-                * backref was in testing tree. The old format
-                * existed about one week.
-                */
-               printf("\n * Found old mixed backref format. "
-                      "The old format is not supported! *"
-                      "\n * Please mount the FS in readonly mode, "
-                      "backup data and re-format the FS. *\n\n");
-               err |= 1;
-       }
        printf("found %llu bytes used, ",
               (unsigned long long)bytes_used);
        if (err)