From 54cf41c969da6637cce790b7400da1451609db9b Mon Sep 17 00:00:00 2001
From: Byungchul Park <byungchul@sk.com>
Date: Fri, 15 May 2026 12:47:01 +0900
Subject: Revert "mm: introduce a new page type for page pool in page type"

This reverts commit db359fccf212 ("mm: introduce a new page type for page
pool in page type") and a part of 735a309b4bfb9e ("net: add net_iov_init()
and use it to initialize ->page_type").

Netpp page_type'ed pages might be used in mapping so as to use @_mapcount.
However, since @page_type and @_mapcount are union'ed in struct page,
these two can't be used at the same time.  Revert the commit introducing
page_type for Netpp for now.

The patch will be retried once @page_type and @_mapcount get allowed to be
used at the same time.

The revert also includes removal of @page_type initialization part
introduced by commit 735a309b4bfb9e ("net: add net_iov_init() and use it
to initialize ->page_type"), which will be restored on the retry.

Link: https://lore.kernel.org/20260515034701.17027-1-byungchul@sk.com
Fixes: db359fccf212 ("mm: introduce a new page type for page pool in page type")
Signed-off-by: Byungchul Park <byungchul@sk.com>
Reported-by: Dragos Tatulea <dtatulea@nvidia.com>
Closes: https://lore.kernel.org/all/982b9bc1-0a0a-4fc5-8e3a-3672db2b29a1@nvidia.com
Acked-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Acked-by: Harry Yoo (Oracle) <harry@kernel.org>
Reviewed-by: Lorenzo Stoakes <ljs@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Cc: Jesper Dangaard Brouer <hawk@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Mark Bloch <mbloch@nvidia.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Pavel Begunkov <asml.silence@gmail.com>
Cc: Saeed Mahameed <saeedm@nvidia.com>
Cc: Simon Horman <horms@kernel.org>
Cc: Stanislav Fomichev <sdf@fomichev.me>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Tariq Toukan <tariqt@nvidia.com>
Cc: Toke Hoiland-Jorgensen <toke@redhat.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
 mm/page_alloc.c | 13 ++++---------
 1 file changed, 4 insertions(+), 9 deletions(-)

(limited to 'mm')

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 23c7298d3be2..d49c254174da 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1035,6 +1035,7 @@ static inline bool page_expected_state(struct page *page,
 #ifdef CONFIG_MEMCG
 			page->memcg_data |
 #endif
+			page_pool_page_is_pp(page) |
 			(page->flags.f & check_flags)))
 		return false;
 
@@ -1061,6 +1062,8 @@ static const char *page_bad_reason(struct page *page, unsigned long flags)
 	if (unlikely(page->memcg_data))
 		bad_reason = "page still charged to cgroup";
 #endif
+	if (unlikely(page_pool_page_is_pp(page)))
+		bad_reason = "page_pool leak";
 	return bad_reason;
 }
 
@@ -1377,17 +1380,9 @@ __always_inline bool __free_pages_prepare(struct page *page,
 		mod_mthp_stat(order, MTHP_STAT_NR_ANON, -1);
 		folio->mapping = NULL;
 	}
-	if (unlikely(page_has_type(page))) {
-		/* networking expects to clear its page type before releasing */
-		if (is_check_pages_enabled()) {
-			if (unlikely(PageNetpp(page))) {
-				bad_page(page, "page_pool leak");
-				return false;
-			}
-		}
+	if (unlikely(page_has_type(page)))
 		/* Reset the page_type (which overlays _mapcount) */
 		page->page_type = UINT_MAX;
-	}
 
 	if (is_check_pages_enabled()) {
 		if (free_page_is_bad(page))
-- 
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