btrfs: Remove 'objectid' member from struct btrfs_root

There are two members in struct btrfs_root which indicate root's
objectid: objectid and root_key.objectid.

They are both set to the same value in __setup_root():

  static void __setup_root(struct btrfs_root *root,
                           struct btrfs_fs_info *fs_info,
                           u64 objectid)
  {
    ...
    root->objectid = objectid;
    ...
    root->root_key.objectid = objecitd;
    ...
  }

and not changed to other value after initialization.

grep in btrfs directory shows both are used in many places:
  $ grep -rI "root->root_key.objectid" | wc -l
  133
  $ grep -rI "root->objectid" | wc -l
  55
 (4.17, inc. some noise)

It is confusing to have two similar variable names and it seems
that there is no rule about which should be used in a certain case.

Since ->root_key itself is needed for tree reloc tree, let's remove
'objecitd' member and unify code to use ->root_key.objectid in all places.

Signed-off-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 4 insertions, 4 deletions

diff --git a/fs/btrfs/ref-verify.c b/fs/btrfs/ref-verify.c
index e5b9e596bb92..d69fbfb30aa9 100644
--- a/fs/btrfs/ref-verify.c
+++ b/fs/btrfs/ref-verify.c
@@ -732,7 +732,7 @@ int btrfs_ref_tree_mod(struct btrfs_root *root, u64 bytenr, u64 num_bytes,
 
         INIT_LIST_HEAD(&ra->list);
         ra->action = action;
-        ra->root = root->objectid;
+        ra->root = root->root_key.objectid;
 
         /*
          * This is an allocation, preallocate the block_entry in case we haven't
@@ -787,8 +787,8 @@ int btrfs_ref_tree_mod(struct btrfs_root *root, u64 bytenr, u64 num_bytes,
                          * one we want to lookup below when we modify the
                          * re->num_refs.
                          */
-                        ref_root = root->objectid;
-                        re->root_objectid = root->objectid;
+                        ref_root = root->root_key.objectid;
+                        re->root_objectid = root->root_key.objectid;
                         re->num_refs = 0;
                 }
 
@@ -862,7 +862,7 @@ int btrfs_ref_tree_mod(struct btrfs_root *root, u64 bytenr, u64 num_bytes,
                          * didn't thik of some other corner case.
                          */
                         btrfs_err(fs_info, "failed to find root %llu for %llu",
-                                  root->objectid, be->bytenr);
+                                  root->root_key.objectid, be->bytenr);
                         dump_block_entry(fs_info, be);
                         dump_ref_action(fs_info, ra);
                         kfree(ra);