Linux 3.5 compat, end_writeback() changed to clear_inode()

The end_writeback() function was changed by moving the call to
inode_sync_wait() earlier in to evict().   This effecitvely changes
the ordering of the sync but it does not impact the details of
the zfs implementation.

However, as part of this change end_writeback() was renamed to
clear_inode() to reflect the new semantics.  This change does
impact us and clear_inode() now maps to end_writeback() for
kernels prior to 3.5.

Signed-off-by: Richard Yao <[email protected]>
Signed-off-by: Brian Behlendorf <[email protected]>
Closes #784

Makefile.in

@@ -87,6 +87,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-blkdev-get-by-path.m4 \
 	$(top_srcdir)/config/kernel-blkdev-get.m4 \
 	$(top_srcdir)/config/kernel-check-disk-size-change.m4 \
+	$(top_srcdir)/config/kernel-clear-inode.m4 \
 	$(top_srcdir)/config/kernel-create-umode-t.m4 \
 	$(top_srcdir)/config/kernel-d-make-root.m4 \
 	$(top_srcdir)/config/kernel-d-obtain-alias.m4 \

cmd/Makefile.in

@@ -64,6 +64,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-blkdev-get-by-path.m4 \
 	$(top_srcdir)/config/kernel-blkdev-get.m4 \
 	$(top_srcdir)/config/kernel-check-disk-size-change.m4 \
+	$(top_srcdir)/config/kernel-clear-inode.m4 \
 	$(top_srcdir)/config/kernel-create-umode-t.m4 \
 	$(top_srcdir)/config/kernel-d-make-root.m4 \
 	$(top_srcdir)/config/kernel-d-obtain-alias.m4 \

cmd/mount_zfs/Makefile.in

@@ -67,6 +67,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-blkdev-get-by-path.m4 \
 	$(top_srcdir)/config/kernel-blkdev-get.m4 \
 	$(top_srcdir)/config/kernel-check-disk-size-change.m4 \
+	$(top_srcdir)/config/kernel-clear-inode.m4 \
 	$(top_srcdir)/config/kernel-create-umode-t.m4 \
 	$(top_srcdir)/config/kernel-d-make-root.m4 \
 	$(top_srcdir)/config/kernel-d-obtain-alias.m4 \

cmd/vdev_id/Makefile.in

@@ -66,6 +66,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-blkdev-get-by-path.m4 \
 	$(top_srcdir)/config/kernel-blkdev-get.m4 \
 	$(top_srcdir)/config/kernel-check-disk-size-change.m4 \
+	$(top_srcdir)/config/kernel-clear-inode.m4 \
 	$(top_srcdir)/config/kernel-create-umode-t.m4 \
 	$(top_srcdir)/config/kernel-d-make-root.m4 \
 	$(top_srcdir)/config/kernel-d-obtain-alias.m4 \

cmd/zdb/Makefile.in

@@ -67,6 +67,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-blkdev-get-by-path.m4 \
 	$(top_srcdir)/config/kernel-blkdev-get.m4 \
 	$(top_srcdir)/config/kernel-check-disk-size-change.m4 \
+	$(top_srcdir)/config/kernel-clear-inode.m4 \
 	$(top_srcdir)/config/kernel-create-umode-t.m4 \
 	$(top_srcdir)/config/kernel-d-make-root.m4 \
 	$(top_srcdir)/config/kernel-d-obtain-alias.m4 \

cmd/zfs/Makefile.in

@@ -67,6 +67,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-blkdev-get-by-path.m4 \
 	$(top_srcdir)/config/kernel-blkdev-get.m4 \
 	$(top_srcdir)/config/kernel-check-disk-size-change.m4 \
+	$(top_srcdir)/config/kernel-clear-inode.m4 \
 	$(top_srcdir)/config/kernel-create-umode-t.m4 \
 	$(top_srcdir)/config/kernel-d-make-root.m4 \
 	$(top_srcdir)/config/kernel-d-obtain-alias.m4 \

cmd/zinject/Makefile.in

@@ -67,6 +67,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-blkdev-get-by-path.m4 \
 	$(top_srcdir)/config/kernel-blkdev-get.m4 \
 	$(top_srcdir)/config/kernel-check-disk-size-change.m4 \
+	$(top_srcdir)/config/kernel-clear-inode.m4 \
 	$(top_srcdir)/config/kernel-create-umode-t.m4 \
 	$(top_srcdir)/config/kernel-d-make-root.m4 \
 	$(top_srcdir)/config/kernel-d-obtain-alias.m4 \

cmd/zpios/Makefile.in

@@ -67,6 +67,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-blkdev-get-by-path.m4 \
 	$(top_srcdir)/config/kernel-blkdev-get.m4 \
 	$(top_srcdir)/config/kernel-check-disk-size-change.m4 \
+	$(top_srcdir)/config/kernel-clear-inode.m4 \
 	$(top_srcdir)/config/kernel-create-umode-t.m4 \
 	$(top_srcdir)/config/kernel-d-make-root.m4 \
 	$(top_srcdir)/config/kernel-d-obtain-alias.m4 \

cmd/zpool/Makefile.in

@@ -67,6 +67,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-blkdev-get-by-path.m4 \
 	$(top_srcdir)/config/kernel-blkdev-get.m4 \
 	$(top_srcdir)/config/kernel-check-disk-size-change.m4 \
+	$(top_srcdir)/config/kernel-clear-inode.m4 \
 	$(top_srcdir)/config/kernel-create-umode-t.m4 \
 	$(top_srcdir)/config/kernel-d-make-root.m4 \
 	$(top_srcdir)/config/kernel-d-obtain-alias.m4 \

cmd/zpool_id/Makefile.in

@@ -66,6 +66,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-blkdev-get-by-path.m4 \
 	$(top_srcdir)/config/kernel-blkdev-get.m4 \
 	$(top_srcdir)/config/kernel-check-disk-size-change.m4 \
+	$(top_srcdir)/config/kernel-clear-inode.m4 \
 	$(top_srcdir)/config/kernel-create-umode-t.m4 \
 	$(top_srcdir)/config/kernel-d-make-root.m4 \
 	$(top_srcdir)/config/kernel-d-obtain-alias.m4 \

cmd/zpool_layout/Makefile.in

@@ -66,6 +66,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-blkdev-get-by-path.m4 \
 	$(top_srcdir)/config/kernel-blkdev-get.m4 \
 	$(top_srcdir)/config/kernel-check-disk-size-change.m4 \
+	$(top_srcdir)/config/kernel-clear-inode.m4 \
 	$(top_srcdir)/config/kernel-create-umode-t.m4 \
 	$(top_srcdir)/config/kernel-d-make-root.m4 \
 	$(top_srcdir)/config/kernel-d-obtain-alias.m4 \

cmd/ztest/Makefile.in

@@ -67,6 +67,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-blkdev-get-by-path.m4 \
 	$(top_srcdir)/config/kernel-blkdev-get.m4 \
 	$(top_srcdir)/config/kernel-check-disk-size-change.m4 \
+	$(top_srcdir)/config/kernel-clear-inode.m4 \
 	$(top_srcdir)/config/kernel-create-umode-t.m4 \
 	$(top_srcdir)/config/kernel-d-make-root.m4 \
 	$(top_srcdir)/config/kernel-d-obtain-alias.m4 \

cmd/zvol_id/Makefile.in

@@ -67,6 +67,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-blkdev-get-by-path.m4 \
 	$(top_srcdir)/config/kernel-blkdev-get.m4 \
 	$(top_srcdir)/config/kernel-check-disk-size-change.m4 \
+	$(top_srcdir)/config/kernel-clear-inode.m4 \
 	$(top_srcdir)/config/kernel-create-umode-t.m4 \
 	$(top_srcdir)/config/kernel-d-make-root.m4 \
 	$(top_srcdir)/config/kernel-d-obtain-alias.m4 \

config/kernel-clear-inode.m4

@@ -0,0 +1,29 @@
+dnl #
+dnl # 3.5.0 API change
+dnl # torvalds/linux@dbd5768f87ff6fb0a4fe09c4d7b6c4a24de99430 and
+dnl # torvalds/linux@7994e6f7254354e03028a11f98a27bd67dace9f1 reworked
+dnl # where inode_sync_wait() is called.
+dnl #
+dnl # Prior to these changes it would occur in end_writeback() but due
+dnl # to various issues (described in the above commits) it has been
+dnl # moved to evict().   This changes the ordering is which sync occurs
+dnl # but otherwise doesn't impact the zpl implementation.
+dnl #
+dnl # The major impact here is the renaming of end_writeback() to
+dnl # clear_inode().  However, care must be taken when detecting this
+dnl # API change because as recently as 2.6.35 there was a clear_inode()
+dnl # function.  However, it was made obsolete by the evict_inode() API
+dnl # change at the same time.
+dnl #
+dnl # Therefore, to ensure we have the correct API we only allow the
+dnl # clear_inode() compatibility code to be defined iff the evict_inode()
+dnl # functionality is also detected.
+dnl #
+AC_DEFUN([ZFS_AC_KERNEL_CLEAR_INODE], [
+	ZFS_CHECK_SYMBOL_EXPORT(
+		[clear_inode],
+		[fs/inode.c],
+		[AC_DEFINE(HAVE_CLEAR_INODE, 1,
+		[clear_inode() is available])],
+		[])
+])

config/kernel.m4

@@ -51,6 +51,7 @@ AC_DEFUN([ZFS_AC_CONFIG_KERNEL], [
 	ZFS_AC_KERNEL_CREATE_UMODE_T
 	ZFS_AC_KERNEL_AUTOMOUNT
 	ZFS_AC_KERNEL_ENCODE_FH_WITH_INODE
+	ZFS_AC_KERNEL_CLEAR_INODE
 	ZFS_AC_KERNEL_INSERT_INODE_LOCKED
 	ZFS_AC_KERNEL_D_MAKE_ROOT
 	ZFS_AC_KERNEL_D_OBTAIN_ALIAS

configure

@@ -16410,6 +16410,59 @@ fi
 
 
 
+	{ $as_echo "$as_me:$LINENO: checking whether symbol clear_inode is exported" >&5
+$as_echo_n "checking whether symbol clear_inode is exported... " >&6; }
+	grep -q -E '[[:space:]]clear_inode[[:space:]]' \
+		$LINUX_OBJ/$LINUX_SYMBOLS 2>/dev/null
+	rc=$?
+	if test $rc -ne 0; then
+
+		export=0
+		for file in fs/inode.c; do
+			grep -q -E "EXPORT_SYMBOL.*(clear_inode)" "$LINUX/$file" 2>/dev/null
+			rc=$?
+			if test $rc -eq 0; then
+
+				export=1
+				break;
+
+fi
+
+		done
+		if test $export -eq 0; then
+
+			{ $as_echo "$as_me:$LINENO: result: no" >&5
+$as_echo "no" >&6; }
+
+
+else
+
+			{ $as_echo "$as_me:$LINENO: result: yes" >&5
+$as_echo "yes" >&6; }
+
+cat >>confdefs.h <<\_ACEOF
+#define HAVE_CLEAR_INODE 1
+_ACEOF
+
+
+fi
+
+
+else
+
+		{ $as_echo "$as_me:$LINENO: result: yes" >&5
+$as_echo "yes" >&6; }
+
+cat >>confdefs.h <<\_ACEOF
+#define HAVE_CLEAR_INODE 1
+_ACEOF
+
+
+fi
+
+
+
+
 	{ $as_echo "$as_me:$LINENO: checking whether symbol insert_inode_locked is exported" >&5
 $as_echo_n "checking whether symbol insert_inode_locked is exported... " >&6; }
 	grep -q -E '[[:space:]]insert_inode_locked[[:space:]]' \
@@ -23076,6 +23129,59 @@ fi
 
 
 
+	{ $as_echo "$as_me:$LINENO: checking whether symbol clear_inode is exported" >&5
+$as_echo_n "checking whether symbol clear_inode is exported... " >&6; }
+	grep -q -E '[[:space:]]clear_inode[[:space:]]' \
+		$LINUX_OBJ/$LINUX_SYMBOLS 2>/dev/null
+	rc=$?
+	if test $rc -ne 0; then
+
+		export=0
+		for file in fs/inode.c; do
+			grep -q -E "EXPORT_SYMBOL.*(clear_inode)" "$LINUX/$file" 2>/dev/null
+			rc=$?
+			if test $rc -eq 0; then
+
+				export=1
+				break;
+
+fi
+
+		done
+		if test $export -eq 0; then
+
+			{ $as_echo "$as_me:$LINENO: result: no" >&5
+$as_echo "no" >&6; }
+
+
+else
+
+			{ $as_echo "$as_me:$LINENO: result: yes" >&5
+$as_echo "yes" >&6; }
+
+cat >>confdefs.h <<\_ACEOF
+#define HAVE_CLEAR_INODE 1
+_ACEOF
+
+
+fi
+
+
+else
+
+		{ $as_echo "$as_me:$LINENO: result: yes" >&5
+$as_echo "yes" >&6; }
+
+cat >>confdefs.h <<\_ACEOF
+#define HAVE_CLEAR_INODE 1
+_ACEOF
+
+
+fi
+
+
+
+
 	{ $as_echo "$as_me:$LINENO: checking whether symbol insert_inode_locked is exported" >&5
 $as_echo_n "checking whether symbol insert_inode_locked is exported... " >&6; }
 	grep -q -E '[[:space:]]insert_inode_locked[[:space:]]' \

dracut/90zfs/Makefile.in

@@ -65,6 +65,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-blkdev-get-by-path.m4 \
 	$(top_srcdir)/config/kernel-blkdev-get.m4 \
 	$(top_srcdir)/config/kernel-check-disk-size-change.m4 \
+	$(top_srcdir)/config/kernel-clear-inode.m4 \
 	$(top_srcdir)/config/kernel-create-umode-t.m4 \
 	$(top_srcdir)/config/kernel-d-make-root.m4 \
 	$(top_srcdir)/config/kernel-d-obtain-alias.m4 \

dracut/Makefile.in

@@ -64,6 +64,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-blkdev-get-by-path.m4 \
 	$(top_srcdir)/config/kernel-blkdev-get.m4 \
 	$(top_srcdir)/config/kernel-check-disk-size-change.m4 \
+	$(top_srcdir)/config/kernel-clear-inode.m4 \
 	$(top_srcdir)/config/kernel-create-umode-t.m4 \
 	$(top_srcdir)/config/kernel-d-make-root.m4 \
 	$(top_srcdir)/config/kernel-d-obtain-alias.m4 \

etc/Makefile.in

@@ -64,6 +64,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-blkdev-get-by-path.m4 \
 	$(top_srcdir)/config/kernel-blkdev-get.m4 \
 	$(top_srcdir)/config/kernel-check-disk-size-change.m4 \
+	$(top_srcdir)/config/kernel-clear-inode.m4 \
 	$(top_srcdir)/config/kernel-create-umode-t.m4 \
 	$(top_srcdir)/config/kernel-d-make-root.m4 \
 	$(top_srcdir)/config/kernel-d-obtain-alias.m4 \

etc/init.d/Makefile.in

@@ -65,6 +65,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-blkdev-get-by-path.m4 \
 	$(top_srcdir)/config/kernel-blkdev-get.m4 \
 	$(top_srcdir)/config/kernel-check-disk-size-change.m4 \
+	$(top_srcdir)/config/kernel-clear-inode.m4 \
 	$(top_srcdir)/config/kernel-create-umode-t.m4 \
 	$(top_srcdir)/config/kernel-d-make-root.m4 \
 	$(top_srcdir)/config/kernel-d-obtain-alias.m4 \

etc/zfs/Makefile.in

@@ -65,6 +65,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-blkdev-get-by-path.m4 \
 	$(top_srcdir)/config/kernel-blkdev-get.m4 \
 	$(top_srcdir)/config/kernel-check-disk-size-change.m4 \
+	$(top_srcdir)/config/kernel-clear-inode.m4 \
 	$(top_srcdir)/config/kernel-create-umode-t.m4 \
 	$(top_srcdir)/config/kernel-d-make-root.m4 \
 	$(top_srcdir)/config/kernel-d-obtain-alias.m4 \

include/Makefile.in

@@ -66,6 +66,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-blkdev-get-by-path.m4 \
 	$(top_srcdir)/config/kernel-blkdev-get.m4 \
 	$(top_srcdir)/config/kernel-check-disk-size-change.m4 \
+	$(top_srcdir)/config/kernel-clear-inode.m4 \
 	$(top_srcdir)/config/kernel-create-umode-t.m4 \
 	$(top_srcdir)/config/kernel-d-make-root.m4 \
 	$(top_srcdir)/config/kernel-d-obtain-alias.m4 \

include/linux/Makefile.in

@@ -66,6 +66,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-blkdev-get-by-path.m4 \
 	$(top_srcdir)/config/kernel-blkdev-get.m4 \
 	$(top_srcdir)/config/kernel-check-disk-size-change.m4 \
+	$(top_srcdir)/config/kernel-clear-inode.m4 \
 	$(top_srcdir)/config/kernel-create-umode-t.m4 \
 	$(top_srcdir)/config/kernel-d-make-root.m4 \
 	$(top_srcdir)/config/kernel-d-obtain-alias.m4 \

include/linux/vfs_compat.h

@@ -121,4 +121,14 @@ typedef	umode_t		zpl_umode_t;
 typedef	int		zpl_umode_t;
 #endif
 
+/*
+ * 3.5 API change,
+ * The clear_inode() function replaces end_writeback() and introduces an
+ * ordering change regarding when the inode_sync_wait() occurs.  See the
+ * configure check in config/kernel-clear-inode.m4 for full details.
+ */
+#if defined(HAVE_EVICT_INODE) && !defined(HAVE_CLEAR_INODE)
+#define clear_inode(ip)		end_writeback(ip)
+#endif /* HAVE_EVICT_INODE && !HAVE_CLEAR_INODE */
+
 #endif /* _ZFS_VFS_H */

include/sys/Makefile.in

@@ -66,6 +66,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-blkdev-get-by-path.m4 \
 	$(top_srcdir)/config/kernel-blkdev-get.m4 \
 	$(top_srcdir)/config/kernel-check-disk-size-change.m4 \
+	$(top_srcdir)/config/kernel-clear-inode.m4 \
 	$(top_srcdir)/config/kernel-create-umode-t.m4 \
 	$(top_srcdir)/config/kernel-d-make-root.m4 \
 	$(top_srcdir)/config/kernel-d-obtain-alias.m4 \

include/sys/fm/Makefile.in

@@ -66,6 +66,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-blkdev-get-by-path.m4 \
 	$(top_srcdir)/config/kernel-blkdev-get.m4 \
 	$(top_srcdir)/config/kernel-check-disk-size-change.m4 \
+	$(top_srcdir)/config/kernel-clear-inode.m4 \
 	$(top_srcdir)/config/kernel-create-umode-t.m4 \
 	$(top_srcdir)/config/kernel-d-make-root.m4 \
 	$(top_srcdir)/config/kernel-d-obtain-alias.m4 \

include/sys/fm/fs/Makefile.in

@@ -66,6 +66,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-blkdev-get-by-path.m4 \
 	$(top_srcdir)/config/kernel-blkdev-get.m4 \
 	$(top_srcdir)/config/kernel-check-disk-size-change.m4 \
+	$(top_srcdir)/config/kernel-clear-inode.m4 \
 	$(top_srcdir)/config/kernel-create-umode-t.m4 \
 	$(top_srcdir)/config/kernel-d-make-root.m4 \
 	$(top_srcdir)/config/kernel-d-obtain-alias.m4 \

include/sys/fs/Makefile.in

@@ -66,6 +66,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-blkdev-get-by-path.m4 \
 	$(top_srcdir)/config/kernel-blkdev-get.m4 \
 	$(top_srcdir)/config/kernel-check-disk-size-change.m4 \
+	$(top_srcdir)/config/kernel-clear-inode.m4 \
 	$(top_srcdir)/config/kernel-create-umode-t.m4 \
 	$(top_srcdir)/config/kernel-d-make-root.m4 \
 	$(top_srcdir)/config/kernel-d-obtain-alias.m4 \

lib/Makefile.in

@@ -64,6 +64,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-blkdev-get-by-path.m4 \
 	$(top_srcdir)/config/kernel-blkdev-get.m4 \
 	$(top_srcdir)/config/kernel-check-disk-size-change.m4 \
+	$(top_srcdir)/config/kernel-clear-inode.m4 \
 	$(top_srcdir)/config/kernel-create-umode-t.m4 \
 	$(top_srcdir)/config/kernel-d-make-root.m4 \
 	$(top_srcdir)/config/kernel-d-obtain-alias.m4 \

lib/libavl/Makefile.in

@@ -66,6 +66,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-blkdev-get-by-path.m4 \
 	$(top_srcdir)/config/kernel-blkdev-get.m4 \
 	$(top_srcdir)/config/kernel-check-disk-size-change.m4 \
+	$(top_srcdir)/config/kernel-clear-inode.m4 \
 	$(top_srcdir)/config/kernel-create-umode-t.m4 \
 	$(top_srcdir)/config/kernel-d-make-root.m4 \
 	$(top_srcdir)/config/kernel-d-obtain-alias.m4 \

lib/libefi/Makefile.in

@@ -66,6 +66,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-blkdev-get-by-path.m4 \
 	$(top_srcdir)/config/kernel-blkdev-get.m4 \
 	$(top_srcdir)/config/kernel-check-disk-size-change.m4 \
+	$(top_srcdir)/config/kernel-clear-inode.m4 \
 	$(top_srcdir)/config/kernel-create-umode-t.m4 \
 	$(top_srcdir)/config/kernel-d-make-root.m4 \
 	$(top_srcdir)/config/kernel-d-obtain-alias.m4 \

lib/libnvpair/Makefile.in

@@ -66,6 +66,7 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/kernel-blkdev-get-by-path.m4 \
 	$(top_srcdir)/config/kernel-blkdev-get.m4 \
 	$(top_srcdir)/config/kernel-check-disk-size-change.m4 \
+	$(top_srcdir)/config/kernel-clear-inode.m4 \
 	$(top_srcdir)/config/kernel-create-umode-t.m4 \
 	$(top_srcdir)/config/kernel-d-make-root.m4 \
 	$(top_srcdir)/config/kernel-d-obtain-alias.m4 \