From: Shivank Garg <shivankg@amd.com>
Date: Wed, 11 Jun 2025 05:27:07 +0000 (+0000)
Subject: mm: use folio_expected_ref_count() helper for reference counting
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a984f16fba2cbadfd8f3310cf506a484dc5bdeb6;p=thirdparty%2Fkernel%2Flinux.git

mm: use folio_expected_ref_count() helper for reference counting

Replace open-coded folio reference count calculations with the
folio_expected_ref_count().

No functional changes intended.

Link: https://lkml.kernel.org/r/20250611052706.515408-2-shivankg@amd.com
Signed-off-by: Shivank Garg <shivankg@amd.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Marc Rutland <mark.rutland@arm.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Namhyung kim <namhyung@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 4c965ba77f9f8..8a601df870720 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -436,8 +436,7 @@ static int __uprobe_write_opcode(struct vm_area_struct *vma,
 	 * there are no unexpected folio references ...
 	 */
 	if (is_register || userfaultfd_missing(vma) ||
-	    (folio_ref_count(folio) != folio_mapcount(folio) + 1 +
-	     folio_test_swapcache(folio) * folio_nr_pages(folio)))
+	    (folio_ref_count(folio) != folio_expected_ref_count(folio) + 1))
 		goto remap;
 
 	/*
diff --git a/mm/memfd.c b/mm/memfd.c
index 4fc98abe66277..65a107f72e399 100644
--- a/mm/memfd.c
+++ b/mm/memfd.c
@@ -32,8 +32,7 @@
 
 static bool memfd_folio_has_extra_refs(struct folio *folio)
 {
-	return folio_ref_count(folio) - folio_mapcount(folio) !=
-	       folio_nr_pages(folio);
+	return folio_ref_count(folio) != folio_expected_ref_count(folio);
 }
 
 static void memfd_tag_pins(struct xa_state *xas)