From: Ira Weiny <ira.weiny@intel.com>
Date: Thu, 29 Dec 2022 14:04:46 -0800
Subject: [PATCH] cifs: Fix kmap_local_page() unmapping
Git-commit: 67fcb2c598bc7643f694e8194d5c300a52af5aa9
References: git-fixes
Patch-mainline: v6.2-rc3

kmap_local_page() requires kunmap_local() to unmap the mapping.  In
addition memcpy_page() is provided to perform this common memcpy
pattern.

Replace the kmap_local_page() and broken kunmap() with memcpy_page()

Fixes: d406d26745ab ("cifs: skip alloc when request has no pages")
Reviewed-by: Paulo Alcantara <pc@cjr.nz>
Reviewed-by: "Fabio M. De Francesco" <fmdefrancesco@gmail.com>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Acked-by: Paulo Alcantara <palcantara@suse.de>
---
 fs/cifs/smb2ops.c | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index dc160de7a6de..0d7e9bcd9f34 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -4488,17 +4488,12 @@ smb3_init_transform_rq(struct TCP_Server_Info *server, int num_rqst,
 
 		/* copy pages form the old */
 		for (j = 0; j < npages; j++) {
-			char *dst, *src;
 			unsigned int offset, len;
 
 			rqst_page_get_length(new, j, &len, &offset);
 
-			dst = kmap_local_page(new->rq_pages[j]) + offset;
-			src = kmap_local_page(old->rq_pages[j]) + offset;
-
-			memcpy(dst, src, len);
-			kunmap(new->rq_pages[j]);
-			kunmap(old->rq_pages[j]);
+			memcpy_page(new->rq_pages[j], offset,
+				    old->rq_pages[j], offset, len);
 		}
 	}
 
-- 
2.39.0