Merge pull request #1642 from robertbaldyga/xfs-ioclass-fix

Fix io classification for XFS

configure.d/1_page_mapping.conf

@@ -0,0 +1,45 @@
+#!/bin/bash
+#
+# Copyright(c) 2025 Huawei Technologies
+# SPDX-License-Identifier: BSD-3-Clause
+#
+
+. $(dirname $3)/conf_framework.sh
+
+check() {
+	cur_name=$(basename $2)
+	config_file_path=$1
+	if compile_module $cur_name "page_folio((struct page *)NULL);" "linux/page-flags.h"
+	then
+		echo $cur_name "1" >> $config_file_path
+	else
+		echo $cur_name "2" >> $config_file_path
+	fi
+}
+
+apply() {
+    case "$1" in
+    "1")
+		add_function "
+	static inline struct address_space *cas_page_mapping(struct page *page)
+	{
+		struct folio *folio = page_folio(page);
+
+		return folio->mapping;
+	}" ;;
+
+    "2")
+		add_function "
+	static inline struct address_space *cas_page_mapping(struct page *page)
+	{
+		if (PageCompound(page))
+			return NULL;
+
+		return page->mapping;
+	}" ;;
+    *)
+        exit 1
+    esac
+}
+
+conf_run $@

modules/cas_cache/classifier.c

@@ -53,7 +53,7 @@ static cas_cls_eval_t _cas_cls_metadata_test(struct cas_classifier *cls,
 	if (PageAnon(io->page))
 		return cas_cls_eval_no;
 
-	if (PageSlab(io->page) || PageCompound(io->page)) {
+	if (PageSlab(io->page)) {
 		/* A filesystem issues IO on pages that does not belongs
 		 * to the file page cache. It means that it is a
 		 * part of metadata
@@ -61,7 +61,7 @@ static cas_cls_eval_t _cas_cls_metadata_test(struct cas_classifier *cls,
 		return cas_cls_eval_yes;
 	}
 
-	if (!io->page->mapping) {
+	if (!cas_page_mapping(io->page)) {
 		/* XFS case, page are allocated internally and do not
 		 * have references into inode
 		 */
@@ -1229,6 +1229,7 @@ static void _cas_cls_get_bio_context(struct bio *bio,
 	struct cas_cls_io *ctx)
 {
 	struct page *page = NULL;
+	struct address_space *mapping;
 
 	if (!bio)
 		return;
@@ -1246,13 +1247,14 @@ static void _cas_cls_get_bio_context(struct bio *bio,
 	if (PageAnon(page))
 		return;
 
-	if (PageSlab(page) || PageCompound(page))
+	if (PageSlab(page))
 		return;
 
-	if (!page->mapping)
+	mapping = cas_page_mapping(page);
+	if (!mapping)
 		return;
 
-	ctx->inode = page->mapping->host;
+	ctx->inode = mapping->host;
 
 	return;
 }