From baf2979ed35c1a9c2e90e84416e220ab3d25140a Mon Sep 17 00:00:00 2001
From: Brian Behlendorf <behlendorf1@llnl.gov>
Date: Tue, 10 Nov 2009 14:06:57 -0800
Subject: [PATCH] Linux 2.6.31 Compatibility Updates

SPL_AC_2ARGS_SET_FS_PWD macro updated to explicitly include
linux/fs_struct.h which was dropped from linux/sched.h.

min_wmark_pages, low_wmark_pages, high_wmark_pages macros
introduced in newer kernels.  For older kernels mm_compat.h
was introduced to define them as needed as direct mappings
to per zone min_pages, low_pages, max_pages.
---
 config/spl-build.m4       |  1 +
 configure                 |  2 ++
 include/linux/mm_compat.h | 22 ++++++++++++++++++++++
 include/sys/kmem.h        |  2 +-
 include/sys/vnode.h       |  1 +
 module/spl/spl-kmem.c     |  6 +++---
 6 files changed, 30 insertions(+), 4 deletions(-)
 create mode 100644 include/linux/mm_compat.h

diff --git a/config/spl-build.m4 b/config/spl-build.m4
index ae45e29da..f50e1757f 100644
--- a/config/spl-build.m4
+++ b/config/spl-build.m4
@@ -1266,6 +1266,7 @@ AC_DEFUN([SPL_AC_2ARGS_SET_FS_PWD],
 	[AC_MSG_CHECKING([whether set_fs_pwd() wants 2 args])
 	SPL_LINUX_TRY_COMPILE([
 		#include <linux/sched.h>
+		#include <linux/fs_struct.h>
 	],[
 		set_fs_pwd(NULL, NULL);
 	],[
diff --git a/configure b/configure
index 15fea65f9..3beeb5df0 100755
--- a/configure
+++ b/configure
@@ -21871,6 +21871,7 @@ cat >>conftest.$ac_ext <<_ACEOF
 
 
 		#include <linux/sched.h>
+		#include <linux/fs_struct.h>
 
 int
 main (void)
@@ -25119,6 +25120,7 @@ cat >>conftest.$ac_ext <<_ACEOF
 
 
 		#include <linux/sched.h>
+		#include <linux/fs_struct.h>
 
 int
 main (void)
diff --git a/include/linux/mm_compat.h b/include/linux/mm_compat.h
new file mode 100644
index 000000000..c99027b44
--- /dev/null
+++ b/include/linux/mm_compat.h
@@ -0,0 +1,22 @@
+#ifndef _SPL_MM_COMPAT_H
+#define _SPL_MM_COMPAT_H
+
+#include <linux/mm.h>
+
+/*
+ * Linux 2.6.31 API Change.
+ * Individual pages_{min,low,high} moved in to watermark array.
+ */
+#ifndef min_wmark_pages
+#define min_wmark_pages(z)	(z->pages_min)
+#endif
+
+#ifndef low_wmark_pages
+#define low_wmark_pages(z)	(z->pages_low)
+#endif
+
+#ifndef high_wmark_pages
+#define high_wmark_pages(z)	(z->pages_high)
+#endif
+
+#endif /* SPL_MM_COMPAT_H */
diff --git a/include/sys/kmem.h b/include/sys/kmem.h
index 7cfbc49e5..3e5eb204f 100644
--- a/include/sys/kmem.h
+++ b/include/sys/kmem.h
@@ -36,7 +36,7 @@ extern "C" {
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/vmalloc.h>
-#include <linux/mm.h>
+#include <linux/mm_compat.h>
 #include <linux/spinlock.h>
 #include <linux/rwsem.h>
 #include <linux/hash.h>
diff --git a/include/sys/vnode.h b/include/sys/vnode.h
index d8a8df272..9568a1392 100644
--- a/include/sys/vnode.h
+++ b/include/sys/vnode.h
@@ -39,6 +39,7 @@ extern "C" {
 #include <linux/namei.h>
 #include <linux/file.h>
 #include <linux/fs.h>
+#include <linux/fs_struct.h>
 #include <linux/mount.h>
 #include <sys/kmem.h>
 #include <sys/mutex.h>
diff --git a/module/spl/spl-kmem.c b/module/spl/spl-kmem.c
index 00d37c798..79a7028c2 100644
--- a/module/spl/spl-kmem.c
+++ b/module/spl/spl-kmem.c
@@ -1826,9 +1826,9 @@ spl_kmem_init_globals(void)
                 if (!populated_zone(zone))
                         continue;
 
-		minfree += zone->pages_min;
-		desfree += zone->pages_low;
-		lotsfree += zone->pages_high;
+		minfree += min_wmark_pages(zone);
+		desfree += low_wmark_pages(zone);
+		lotsfree += high_wmark_pages(zone);
 	}
 
 	/* Solaris default values */
-- 
2.40.0