# \[PATCH v1 3/4\] powerpc/mm: remove linear mapping if \_\_add\_pages() fails in arch\_add\_memory()

- From: David Hildenbrand \<hidden\>
- Date: 2020-10-29 16:27:48 
- List: linuxppc-dev
- Page: https://ratatoskr.run/linuxppc-dev/2020/10/6156818
- Thread: https://ratatoskr.run/linux-mm/2020/10/6156815/t.md

```text
Let's revert what we did in case seomthing goes wrong and we return an
error.

Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <redacted>
Cc: Rashmica Gupta <redacted>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Wei Yang <redacted>
Signed-off-by: David Hildenbrand <redacted>
---
 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 685028451dd2..69b3e8072261 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -165,7 +165,10 @@ 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

```