Subject: [PATCH v2 7/8] powerpc/mm: remove linear mapping if __add_pages() fails in arch_add_memory()

From: David Hildenbrand <[email-masked]>
Date: Wed, 11 Nov 2020 15:53:21 +0100

Let's revert what we did in case seomthing goes wrong and we return an
error - as already done on arm64 and s390x.

Cc: Michael Ellerman <[email-masked]>
Cc: Benjamin Herrenschmidt <[email-masked]>
Cc: Paul Mackerras <[email-masked]>
Cc: Rashmica Gupta <[email-masked]>
Cc: Andrew Morton <[email-masked]>
Cc: Mike Rapoport <[email-masked]>
Cc: Michal Hocko <[email-masked]>
Cc: Oscar Salvador <[email-masked]>
Cc: Wei Yang <[email-masked]>
Signed-off-by: David Hildenbrand <[email-masked]>
---
 arch/powerpc/mm/mem.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index c5755b9efb64..8b946ec68d1b 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -170,7 +170,10 @@ int __ref arch_add_memory(int nid, u64 start, u64 size,
 	rc = arch_create_linear_mapping(nid, start, size, params);
 	if (rc)
 		return rc;
-	return __add_pages(nid, start_pfn, nr_pages, params);
+	rc = __add_pages(nid, start_pfn, nr_pages, params);
+	if (rc)
+		arch_remove_linear_mapping(start, size);
+	return rc;
 }
 
 void __ref arch_remove_memory(int nid, u64 start, u64 size,
-- 
2.26.2