Linux 5.17 compat: detect complete_and_exit() rename

Linux 5.17 sees a rename from complete_and_exit()
to kthread complete_and_exit()

Upstream commit cead18552660702a4a46f58e65188fe5f36e9dfe
("exit: Rename complete_and_exit to kthread_complete_and_exit")

Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes openzfs#12989

config/kernel-kthread.m4

@@ -0,0 +1,27 @@
+AC_DEFUN([ZFS_AC_KERNEL_KTHREAD], [
+	dnl #
+	dnl # 5.17 API,
+	dnl # cead18552660702a4a46f58e65188fe5f36e9dfe ("exit: Rename complete_and_exit to kthread_complete_and_exit")
+	dnl #
+	dnl # Also moves the definition from include/linux/kernel.h to include/linux/kthread.h
+	dnl #
+	AC_MSG_CHECKING([whether kthread_complete_and_exit() is available])
+	ZFS_LINUX_TEST_RESULT([kthread_complete_and_exit], [
+		AC_MSG_RESULT(yes)
+		AC_DEFINE(SPL_KTHREAD_COMPLETE_AND_EXIT, kthread_complete_and_exit, [kthread_complete_and_exit() available])
+	], [
+		AC_MSG_RESULT(no)
+		AC_DEFINE(SPL_KTHREAD_COMPLETE_AND_EXIT, complete_and_exit, [using complete_and_exit() instead])
+	])
+])
+
+AC_DEFUN([ZFS_AC_KERNEL_SRC_KTHREAD], [
+	ZFS_LINUX_TEST_SRC([kthread_complete_and_exit], [
+		#include <linux/kthread.h>
+	], [
+		struct completion *completion = NULL;
+		long code = 0;
+
+		kthread_complete_and_exit(completion, code);
+	])
+])

config/kernel.m4

@@ -136,6 +136,7 @@ AC_DEFUN([ZFS_AC_KERNEL_TEST_SRC], [
 	ZFS_AC_KERNEL_SRC_STANDALONE_LINUX_STDARG
 	ZFS_AC_KERNEL_SRC_PAGEMAP_FOLIO_WAIT_BIT
 	ZFS_AC_KERNEL_SRC_ADD_DISK
+	ZFS_AC_KERNEL_SRC_KTHREAD
 
 	AC_MSG_CHECKING([for available kernel interfaces])
 	ZFS_LINUX_TEST_COMPILE_ALL([kabi])
@@ -245,6 +246,7 @@ AC_DEFUN([ZFS_AC_KERNEL_TEST_RESULT], [
 	ZFS_AC_KERNEL_STANDALONE_LINUX_STDARG
 	ZFS_AC_KERNEL_PAGEMAP_FOLIO_WAIT_BIT
 	ZFS_AC_KERNEL_ADD_DISK
+	ZFS_AC_KERNEL_KTHREAD
 ])
 
 dnl #

module/os/linux/spl/spl-thread.c

@@ -66,7 +66,7 @@ void
 __thread_exit(void)
 {
 	tsd_exit();
-	complete_and_exit(NULL, 0);
+	SPL_KTHREAD_COMPLETE_AND_EXIT(NULL, 0);
 	/* Unreachable */
 }
 EXPORT_SYMBOL(__thread_exit);