The next commit will need to find the memcg id from the user-passed path
to the memory cgroup, from sysfs.c.  memcg_path_to_id() is doing that,
but defined in sysfs-schemes.c as a static function.  Move the function
to sysfs-common.c and mark it as non-static, so that the next commit can
reuse the function.

Signed-off-by: SeongJae Park <sj@kernel.org>
---
 mm/damon/sysfs-common.c  | 41 ++++++++++++++++++++++++++++++++++++++++
 mm/damon/sysfs-common.h  |  2 ++
 mm/damon/sysfs-schemes.c | 41 ----------------------------------------
 3 files changed, 43 insertions(+), 41 deletions(-)

diff --git a/mm/damon/sysfs-common.c b/mm/damon/sysfs-common.c
index 83e24a9b5a0db..bdc6ae2639e4f 100644
--- a/mm/damon/sysfs-common.c
+++ b/mm/damon/sysfs-common.c
@@ -104,3 +104,44 @@ const struct kobj_type damon_sysfs_ul_range_ktype = {
 	.default_groups = damon_sysfs_ul_range_groups,
 };
 
+
+static bool damon_sysfs_memcg_path_eq(struct mem_cgroup *memcg,
+		char *memcg_path_buf, char *path)
+{
+#ifdef CONFIG_MEMCG
+	cgroup_path(memcg->css.cgroup, memcg_path_buf, PATH_MAX);
+	if (sysfs_streq(memcg_path_buf, path))
+		return true;
+#endif /* CONFIG_MEMCG */
+	return false;
+}
+
+int damon_sysfs_memcg_path_to_id(char *memcg_path, u64 *id)
+{
+	struct mem_cgroup *memcg;
+	char *path;
+	bool found = false;
+
+	if (!memcg_path)
+		return -EINVAL;
+
+	path = kmalloc_array(PATH_MAX, sizeof(*path), GFP_KERNEL);
+	if (!path)
+		return -ENOMEM;
+
+	for (memcg = mem_cgroup_iter(NULL, NULL, NULL); memcg;
+			memcg = mem_cgroup_iter(NULL, memcg, NULL)) {
+		/* skip offlined memcg */
+		if (!mem_cgroup_online(memcg))
+			continue;
+		if (damon_sysfs_memcg_path_eq(memcg, path, memcg_path)) {
+			*id = mem_cgroup_id(memcg);
+			found = true;
+			mem_cgroup_iter_break(NULL, memcg);
+			break;
+		}
+	}
+
+	kfree(path);
+	return found ? 0 : -EINVAL;
+}
diff --git a/mm/damon/sysfs-common.h b/mm/damon/sysfs-common.h
index 2099adee11d05..3079306966a91 100644
--- a/mm/damon/sysfs-common.h
+++ b/mm/damon/sysfs-common.h
@@ -59,3 +59,5 @@ int damos_sysfs_set_quota_scores(struct damon_sysfs_schemes *sysfs_schemes,
 void damos_sysfs_update_effective_quotas(
 		struct damon_sysfs_schemes *sysfs_schemes,
 		struct damon_ctx *ctx);
+
+int damon_sysfs_memcg_path_to_id(char *memcg_path, u64 *id);
diff --git a/mm/damon/sysfs-schemes.c b/mm/damon/sysfs-schemes.c
index 43a8224d991e8..6b21bbe97d04a 100644
--- a/mm/damon/sysfs-schemes.c
+++ b/mm/damon/sysfs-schemes.c
@@ -2792,47 +2792,6 @@ const struct kobj_type damon_sysfs_schemes_ktype = {
 	.default_groups = damon_sysfs_schemes_groups,
 };
 
-static bool damon_sysfs_memcg_path_eq(struct mem_cgroup *memcg,
-		char *memcg_path_buf, char *path)
-{
-#ifdef CONFIG_MEMCG
-	cgroup_path(memcg->css.cgroup, memcg_path_buf, PATH_MAX);
-	if (sysfs_streq(memcg_path_buf, path))
-		return true;
-#endif /* CONFIG_MEMCG */
-	return false;
-}
-
-static int damon_sysfs_memcg_path_to_id(char *memcg_path, u64 *id)
-{
-	struct mem_cgroup *memcg;
-	char *path;
-	bool found = false;
-
-	if (!memcg_path)
-		return -EINVAL;
-
-	path = kmalloc_array(PATH_MAX, sizeof(*path), GFP_KERNEL);
-	if (!path)
-		return -ENOMEM;
-
-	for (memcg = mem_cgroup_iter(NULL, NULL, NULL); memcg;
-			memcg = mem_cgroup_iter(NULL, memcg, NULL)) {
-		/* skip offlined memcg */
-		if (!mem_cgroup_online(memcg))
-			continue;
-		if (damon_sysfs_memcg_path_eq(memcg, path, memcg_path)) {
-			*id = mem_cgroup_id(memcg);
-			found = true;
-			mem_cgroup_iter_break(NULL, memcg);
-			break;
-		}
-	}
-
-	kfree(path);
-	return found ? 0 : -EINVAL;
-}
-
 static int damon_sysfs_add_scheme_filters(struct damos *scheme,
 		struct damon_sysfs_scheme_filters *sysfs_filters)
 {
-- 
2.47.3