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, 3 insertions, 2 deletions

diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index ae750b1574a2..84006e3dd105 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -1468,7 +1468,7 @@ int btrfs_check_shared(struct btrfs_root *root, u64 inum, u64 bytenr)
         struct seq_list elem = SEQ_LIST_INIT(elem);
         int ret = 0;
         struct share_check shared = {
-                .root_objectid = root->objectid,
+                .root_objectid = root->root_key.objectid,
                 .inum = inum,
                 .share_count = 0,
         };
@@ -2031,7 +2031,8 @@ static int iterate_inode_refs(u64 inum, struct btrfs_root *fs_root,
                         /* path must be released before calling iterate()! */
                         btrfs_debug(fs_root->fs_info,
                                 "following ref at offset %u for inode %llu in tree %llu",
-                                cur, found_key.objectid, fs_root->objectid);
+                                cur, found_key.objectid,
+                                fs_root->root_key.objectid);
                         ret = iterate(parent, name_len,
                                       (unsigned long)(iref + 1), eb, ctx);
                         if (ret)