[PATCH 0/6] Overhaul free objectid code

[Nikolay Borisov <nborisov@suse.com>]

This series aims to make the free objectid code more straighforward. Currently
the highest used objectid is used which implies that when btrfs_get_free_objectid
is called the pre-increment operator is used. At the same time when looking
at how highest_objectid is initialised in find_free_objectid it's using the,
at first looko unusual, 'BTRFS_FREE_OBJECTID - 1'. Furthermore btrfs_find_free_objectid
is badly named as it's used only in initializaion context.

With the series applied the following is achieved:
 * The 2 functions related to free objectid have better naming which describes
 their semantic meaning.

 * highest_objectid is renamed to free_objectid which clearly states what it's
 supposed to hold, also btrfs_get_free_objectid now returns the value and
 does a post-increment which seems more logical than the previous cod.

 * Now it's not necessary to re-initialize free_objectid in create_subvol
 since that member is now consistently initialized when a given root is read
 for the first time in btrfs_init_fs_root->btrfs_init_root_free_objectid.
 Additionally in btrfs_init_root_free_objectid free_objectid is now initialized
 to BTRFS_FIRST_FREE_OBJECTID so it's self-explanatory.

This series survived xfstest as well as a new xfstest which verifies precisely
this functionality.


Nikolay Borisov (6):
  btrfs: Rename btrfs_find_highest_objectid to
    btrfs_init_root_free_objectid
  btrfs: Rename btrfs_find_free_objectid to btrfs_get_free_objectid
  btrfs: Remove useless ASSERTS
  btrfs: Rename highest_objectid to free_objectid
  btrfs: Make free_objectid hold the next available objectid in the root
  btrfs: Remove new_dirid argument from btrfs_create_subvol_root

 fs/btrfs/ctree.h            |  5 ++---
 fs/btrfs/disk-io.c          | 25 ++++++++++---------------
 fs/btrfs/disk-io.h          |  4 ++--
 fs/btrfs/free-space-cache.c |  2 +-
 fs/btrfs/inode.c            | 23 +++++++++++++----------
 fs/btrfs/ioctl.c            | 11 +++--------
 fs/btrfs/relocation.c       |  2 +-
 fs/btrfs/transaction.c      |  2 +-
 fs/btrfs/tree-log.c         |  3 +--
 9 files changed, 34 insertions(+), 43 deletions(-)

--
2.25.1