Re: [PATCH v3 04/16] mm/mmap: Extract the gathering of vmas from do_vmi_align_munmap()

["Liam R. Howlett" <Liam.Howlett@oracle.com>]

* Lorenzo Stoakes <lorenzo.stoakes@oracle.com> [240705 14:01]:
> On Thu, Jul 04, 2024 at 02:27:06PM GMT, Liam R. Howlett wrote:
> > Create vmi_gather_munmap_vmas() to handle the gathering of vmas into a
> > detached maple tree for removal later.  Part of the gathering is the
> > splitting of vmas that span the boundary.
> >
> > Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
> > ---
> >  mm/mmap.c | 82 +++++++++++++++++++++++++++++++++++++++----------------
> >  1 file changed, 58 insertions(+), 24 deletions(-)
> >
> > diff --git a/mm/mmap.c b/mm/mmap.c
> > index 411798f46932..8dc8ffbf9d8d 100644
> > --- a/mm/mmap.c
> > +++ b/mm/mmap.c
> > @@ -2656,32 +2656,29 @@ vmi_complete_munmap_vmas(struct vma_iterator *vmi, struct vm_area_struct *vma,
> >  }
> >
> >  /*
> > - * do_vmi_align_munmap() - munmap the aligned region from @start to @end.
> > + * vmi_gather_munmap_vmas() - Put all VMAs within a range into a maple tree
> > + * for removal at a later date.  Handles splitting first and last if necessary
> > + * and marking the vmas as isolated.
> > + *
> >   * @vmi: The vma iterator
> >   * @vma: The starting vm_area_struct
> >   * @mm: The mm_struct
> >   * @start: The aligned start address to munmap.
> >   * @end: The aligned end address to munmap.
> >   * @uf: The userfaultfd list_head
> > - * @unlock: Set to true to drop the mmap_lock.  unlocking only happens on
> > - * success.
> > + * @mas_detach: The maple state tracking the detached tree
> 
> Missing the locked_vm parameter.

Thanks.  This will be dropped later but I'll add it and drop it later.

> 
> >   *
> > - * Return: 0 on success and drops the lock if so directed, error and leaves the
> > - * lock held otherwise.
> > + * Return: 0 on success
> >   */
> >  static int
> > -do_vmi_align_munmap(struct vma_iterator *vmi, struct vm_area_struct *vma,
> > +vmi_gather_munmap_vmas(struct vma_iterator *vmi, struct vm_area_struct *vma,
> >  		    struct mm_struct *mm, unsigned long start,
> > -		    unsigned long end, struct list_head *uf, bool unlock)
> > +		    unsigned long end, struct list_head *uf,
> > +		    struct ma_state *mas_detach, unsigned long *locked_vm)

...

> 
> Other than trivial comment error, LGTM:
> 
> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>

Thanks!