Messages in this thread | | | Date | Fri, 18 Nov 2016 08:30:29 +0100 | From | Jan Kara <> | Subject | Re: [PATCH 2/9] mm: khugepaged: fix radix tree node leak in shmem collapse error path |
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On Thu 17-11-16 14:11:31, Johannes Weiner wrote: > The radix tree counts valid entries in each tree node. Entries stored > in the tree cannot be removed by simpling storing NULL in the slot or > the internal counters will be off and the node never gets freed again. > > When collapsing a shmem page fails, restore the holes that were filled > with radix_tree_insert() with a proper radix tree deletion. > > Fixes: f3f0e1d2150b ("khugepaged: add support of collapse for tmpfs/shmem pages") > Reported-by: Jan Kara <jack@suse.cz> > Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Looks good. You can add:
Reviewed-by: Jan Kara <jack@suse.cz>
Honza
> --- > mm/khugepaged.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/mm/khugepaged.c b/mm/khugepaged.c > index bdfdab40a813..d553c294de40 100644 > --- a/mm/khugepaged.c > +++ b/mm/khugepaged.c > @@ -1523,9 +1523,11 @@ static void collapse_shmem(struct mm_struct *mm, > if (!page || iter.index < page->index) { > if (!nr_none) > break; > - /* Put holes back where they were */ > - radix_tree_replace_slot(slot, NULL); > nr_none--; > + /* Put holes back where they were */ > + radix_tree_delete(&mapping->page_tree, > + iter.index); > + slot = radix_tree_iter_next(&iter); > continue; > } > > -- > 2.10.2 > -- Jan Kara <jack@suse.com> SUSE Labs, CR
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