On 2/13/25 23:46, Suren Baghdasaryan wrote:
> vma_iter_store() functions can be used both when adding a new vma and
> when updating an existing one. However for existing ones we do not need
> to mark them attached as they are already marked that way. With
> vma->detached being a separate flag, double-marking a vmas as attached
> or detached is not an issue because the flag will simply be overwritten
> with the same value. However once we fold this flag into the refcount
> later in this series, re-attaching or re-detaching a vma becomes an
> issue since these operations will be incrementing/decrementing a
> refcount.
> Introduce vma_iter_store_new() and vma_iter_store_overwrite() to replace
> vma_iter_store() and avoid re-attaching a vma during vma update. Add
> assertions in vma_mark_attached()/vma_mark_detached() to catch invalid
> usage. Update vma tests to check for vma detached state correctness.
>
> Signed-off-by: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Reviewed-by: Vlastimil Babka <vbabka@xxxxxxx>
> ---
> Changes since v9 [1]:
> - Change VM_BUG_ON_VMA() to WARN_ON_ONCE() in vma_assert_{attached|detached},
> per Lorenzo Stoakes
Maybe later we can reduce the paranoia to VM_WARN_ON_ONCE()?
