From 96f5cfb7b3c317d0f3bc3b68ab78c723d022aa45 Mon Sep 17 00:00:00 2001
From: Gleb Chesnokov <gleb.chesnokov@scst.dev>
Date: Fri, 2 Sep 2022 12:38:39 +0300
Subject: [PATCH] scst/include/backport.h: Fix the register_shrinker() backport

The register_shrinker() function has begun to return non void value since
v3.12 version. So fix the backport of this function for kernel versions
before v3.12.

Fixes: 84bd33f9a18c ("scst_mem: Port to Linux kernel v6.0")
---
 scst/include/backport.h | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/scst/include/backport.h b/scst/include/backport.h
index 04c847014..e892014eb 100644
--- a/scst/include/backport.h
+++ b/scst/include/backport.h
@@ -783,7 +783,15 @@ static inline void kvfree(void *addr)
 static inline
 int register_shrinker_backport(struct shrinker *shrinker, const char *fmt, ...)
 {
+/*
+ * See also commit 1d3d4437eae1 ("vmscan: per-node deferred work") # v3.12
+ */
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 12, 0)
 	return register_shrinker(shrinker);
+#else
+	register_shrinker(shrinker);
+	return 0;
+#endif
 }
 
 #define register_shrinker register_shrinker_backport