| Message ID | 20250321053148.1434076-3-gshan@redhat.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Fix parameter passed to page_mapcount_is_type() | expand |
On 21.03.25 06:31, Gavin Shan wrote: > As the comments of page_mapcount_is_type() indicate, the parameter passed > to the function should be one more than page->__mapcount. However, > page->__mapcount is passed to the function by commit 4ffca5a96678 > ("mm: support only one page_type per page") where page_type_has_type() > is replaced by page_mapcount_is_type(), but the parameter isn't adjusted. > > Fix the parameter passed to page_mapcount_is_type() to be (page->__mapcount > + 1). > > Fixes: 4ffca5a96678 ("mm: support only one page_type per page") > Cc: stable@vger.kernel.org # v6.12+ > Signed-off-by: Gavin Shan <gshan@redhat.com> > --- > mm/debug.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/mm/debug.c b/mm/debug.c > index 8d2acf432385..b6bd9555ec7b 100644 > --- a/mm/debug.c > +++ b/mm/debug.c > @@ -71,10 +71,10 @@ static void __dump_folio(struct folio *folio, struct page *page, > unsigned long pfn, unsigned long idx) > { > struct address_space *mapping = folio_mapping(folio); > - int mapcount = atomic_read(&page->_mapcount); > + int mapcount = atomic_read(&page->_mapcount) + 1; > char *type = ""; > > - mapcount = page_mapcount_is_type(mapcount) ? 0 : mapcount + 1; > + mapcount = page_mapcount_is_type(mapcount) ? 0 : mapcount; > pr_warn("page: refcount:%d mapcount:%d mapping:%p index:%#lx pfn:%#lx\n", > folio_ref_count(folio), mapcount, mapping, > folio->index + idx, pfn); Acked-by: David Hildenbrand <david@redhat.com>
diff --git a/mm/debug.c b/mm/debug.c index 8d2acf432385..b6bd9555ec7b 100644 --- a/mm/debug.c +++ b/mm/debug.c @@ -71,10 +71,10 @@ static void __dump_folio(struct folio *folio, struct page *page, unsigned long pfn, unsigned long idx) { struct address_space *mapping = folio_mapping(folio); - int mapcount = atomic_read(&page->_mapcount); + int mapcount = atomic_read(&page->_mapcount) + 1; char *type = ""; - mapcount = page_mapcount_is_type(mapcount) ? 0 : mapcount + 1; + mapcount = page_mapcount_is_type(mapcount) ? 0 : mapcount; pr_warn("page: refcount:%d mapcount:%d mapping:%p index:%#lx pfn:%#lx\n", folio_ref_count(folio), mapcount, mapping, folio->index + idx, pfn);
As the comments of page_mapcount_is_type() indicate, the parameter passed to the function should be one more than page->__mapcount. However, page->__mapcount is passed to the function by commit 4ffca5a96678 ("mm: support only one page_type per page") where page_type_has_type() is replaced by page_mapcount_is_type(), but the parameter isn't adjusted. Fix the parameter passed to page_mapcount_is_type() to be (page->__mapcount + 1). Fixes: 4ffca5a96678 ("mm: support only one page_type per page") Cc: stable@vger.kernel.org # v6.12+ Signed-off-by: Gavin Shan <gshan@redhat.com> --- mm/debug.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)