From 5cb46f6a664db913f0ef2bf8e929c3f8d8cbfc5b Mon Sep 17 00:00:00 2001
From: Tony Hutter <hutter2@llnl.gov>
Date: Wed, 9 Jan 2019 13:16:39 -0800
Subject: [PATCH] Linux 4.18 compat: Use ktime_get_coarse_real_ts64()

Newer kernels remove current_kernel_time64().  Use
ktime_get_coarse_real_ts64() in its place.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes #8258
---
 config/kernel-ktime_get_coarse_real_ts64.m4 | 18 ++++++++++++++++++
 config/kernel.m4                            |  1 +
 include/spl/sys/time.h                      | 12 ++++++++++++
 3 files changed, 31 insertions(+)
 create mode 100644 config/kernel-ktime_get_coarse_real_ts64.m4

diff --git a/config/kernel-ktime_get_coarse_real_ts64.m4 b/config/kernel-ktime_get_coarse_real_ts64.m4
new file mode 100644
index 000000000..d6be8c418
--- /dev/null
+++ b/config/kernel-ktime_get_coarse_real_ts64.m4
@@ -0,0 +1,18 @@
+dnl #
+dnl # 4.18: ktime_get_coarse_real_ts64() added.  Use it in place of
+dnl # current_kernel_time64().
+dnl #
+AC_DEFUN([ZFS_AC_KERNEL_KTIME_GET_COARSE_REAL_TS64],
+	[AC_MSG_CHECKING([whether ktime_get_coarse_real_ts64() exists])
+	ZFS_LINUX_TRY_COMPILE([
+		#include <linux/mm.h>
+	], [
+		struct timespec64 ts;
+		ktime_get_coarse_real_ts64(&ts);
+	], [
+		AC_MSG_RESULT(yes)
+		AC_DEFINE(HAVE_KTIME_GET_COARSE_REAL_TS64, 1, [ktime_get_coarse_real_ts64() exists])
+	], [
+		AC_MSG_RESULT(no)
+	])
+])
diff --git a/config/kernel.m4 b/config/kernel.m4
index 7330c00e1..098c43700 100644
--- a/config/kernel.m4
+++ b/config/kernel.m4
@@ -161,6 +161,7 @@ AC_DEFUN([ZFS_AC_CONFIG_KERNEL], [
 	ZFS_AC_KERNEL_ACL_HAS_REFCOUNT
 	ZFS_AC_KERNEL_USERNS_CAPABILITIES
 	ZFS_AC_KERNEL_IN_COMPAT_SYSCALL
+	ZFS_AC_KERNEL_KTIME_GET_COARSE_REAL_TS64
 
 	AS_IF([test "$LINUX_OBJ" != "$LINUX"], [
 		KERNEL_MAKE="$KERNEL_MAKE O=$LINUX_OBJ"
diff --git a/include/spl/sys/time.h b/include/spl/sys/time.h
index 1a986c9b9..312415b7b 100644
--- a/include/spl/sys/time.h
+++ b/include/spl/sys/time.h
@@ -73,7 +73,13 @@ static inline void
 gethrestime(inode_timespec_t *ts)
 {
 #if defined(HAVE_INODE_TIMESPEC64_TIMES)
+
+#if defined(HAVE_KTIME_GET_COARSE_REAL_TS64)
+	ktime_get_coarse_real_ts64(ts);
+#else
 	*ts = current_kernel_time64();
+#endif /* HAVE_KTIME_GET_COARSE_REAL_TS64 */
+
 #else
 	*ts = current_kernel_time();
 #endif
@@ -83,7 +89,13 @@ static inline time_t
 gethrestime_sec(void)
 {
 #if defined(HAVE_INODE_TIMESPEC64_TIMES)
+#if defined(HAVE_KTIME_GET_COARSE_REAL_TS64)
+	inode_timespec_t ts;
+	ktime_get_coarse_real_ts64(&ts);
+#else
 	inode_timespec_t ts = current_kernel_time64();
+#endif  /* HAVE_KTIME_GET_COARSE_REAL_TS64 */
+
 #else
 	inode_timespec_t ts = current_kernel_time();
 #endif