Re: [PATCH 01/14] mm: Fix comments mentioning i_mutex

Jan Kara
2021-06-10T10:40:52Z

On Thu 10-06-21 17:06:41, Ming Lei wrote:
> On Mon, Jun 07, 2021 at 04:52:11PM +0200, Jan Kara wrote:
> > inode->i_mutex has been replaced with inode->i_rwsem long ago. Fix
> > comments still mentioning i_mutex.
> >
> > Reviewed-by: Christoph Hellwig <hch@lst.de>
> > Acked-by: Hugh Dickins <hughd@google.com>
> > Signed-off-by: Jan Kara <jack@suse.cz>
> > ---
>
> ...
>
> > diff --git a/mm/rmap.c b/mm/rmap.c
> > index 693a610e181d..a35cbbbded0d 100644
> > --- a/mm/rmap.c
> > +++ b/mm/rmap.c
> > @@ -20,9 +20,9 @@
> > /*
> > * Lock ordering in mm:
> > *
> > - * inode->i_mutex (while writing or truncating, not reading or faulting)
> > + * inode->i_rwsem (while writing or truncating, not reading or faulting)
> > * mm->mmap_lock
> > - * page->flags PG_locked (lock_page) * (see huegtlbfs below)
> > + * page->flags PG_locked (lock_page) * (see hugetlbfs below)
> > * hugetlbfs_i_mmap_rwsem_key (in huge_pmd_share)
> > * mapping->i_mmap_rwsem
> > * hugetlb_fault_mutex (hugetlbfs specific page fault mutex)
> > @@ -41,7 +41,7 @@
> > * in arch-dependent flush_dcache_mmap_lock,
> > * within bdi.wb->list_lock in __sync_single_inode)
> > *
> > - * anon_vma->rwsem,mapping->i_mutex (memory_failure, collect_procs_anon)
> > + * anon_vma->rwsem,mapping->i_mmap_rwsem (memory_failure, collect_procs_anon)
>
> This one looks a typo.

Actually it isn't a typo. Memory failure path doesn't touch inode->i_rwsem
at all. It uses mapping->i_mmap_rwsem in collect_procs_file(). So perhaps
the functions listed there should be updated to (collect_procs_anon(),
collect_procs_file()) but the lock name change is IMO correct.

Honza
--
Jan Kara <jack@suse.com>
SUSE Labs, CR