Re: [PATCH 0/6] Overhaul free objectid code

[David Sterba <dsterba@suse.cz>]

On Mon, Dec 07, 2020 at 05:32:31PM +0200, Nikolay Borisov wrote:
> 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

Except patch 3 (the assert) added to misc-next, thanks.