config: fix page_mapping test

It always failed from "unused variable" warnings-errors. The resulting `#define page_mapping(...)` happend to work because it always overrode the kernel's function prototype, but that's brittle. Sponsored-by: https://despairlabs.com/sponsor/ Reviewed-by: Brian Behlendorf <[email protected]> Reviewed-by: Tony Hutter <[email protected]> Reviewed-by: Tino Reichardt <[email protected]> Signed-off-by: Rob Norris <[email protected]> Closes #16479
openzfs · Sep 18, 2024 · 7cdfda3 · 7cdfda3
1 parent 0807423
commit 7cdfda3
Showing 1 changed file with 2 additions and 2 deletions.
diff --git a/config/kernel-mm-pagemap.m4 b/config/kernel-mm-pagemap.m4
@@ -21,8 +21,8 @@ AC_DEFUN([ZFS_AC_KERNEL_SRC_MM_PAGE_MAPPING], [
 	ZFS_LINUX_TEST_SRC([page_mapping], [
 		#include <linux/pagemap.h>
 	],[
-		struct page *p = NULL;
-		struct address_space *m = page_mapping(NULL);
+		struct address_space *m;
+		m = page_mapping(NULL);
 	])
 ])
 AC_DEFUN([ZFS_AC_KERNEL_MM_PAGE_MAPPING], [