Linux compat 2.6.37, invalidate_inodes()

In the 2.6.37 kernel the function invalidate_inodes() is no longer
exported for use by modules.  This memory management functionality
is needed to invalidate the inodes attached to a super block without
unmounting the filesystem.

Because this function still exists in the kernel and the prototype
is available is a common header all we strictly need is the symbol
address.  The address is obtained using spl_kallsyms_lookup_name()
and assigned to the variable invalidate_inodes_fn.  Then a #define
is used to replace all instances of invalidate_inodes() with a
call to the acquired address.  All the complexity is hidden behind
HAVE_INVALIDATE_INODES and invalidate_inodes() can be used as usual.

Long term we should try to get this, or another, interface made
available to modules again.

1 files changed, 82 insertions, 0 deletions

diff --git a/configure b/configure
index c3b08440e..535ca2e7d 100755
--- a/configure
+++ b/configure
@@ -15334,6 +15334,47 @@ _ACEOF
 	fi
 
 
+
+	{ $as_echo "$as_me:$LINENO: checking whether symbol invalidate_inodes is exported" >&5
+$as_echo_n "checking whether symbol invalidate_inodes is exported... " >&6; }
+	grep -q -E '[[:space:]]invalidate_inodes[[:space:]]' \
+		$LINUX_OBJ/Module*.symvers 2>/dev/null
+	rc=$?
+	if test $rc -ne 0; then
+		export=0
+		for file in ; do
+			grep -q -E "EXPORT_SYMBOL.*(invalidate_inodes)" \
+				"$LINUX_OBJ/$file" 2>/dev/null
+			rc=$?
+		        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_INVALIDATE_INODES 1
+_ACEOF
+
+		fi
+	else
+		{ $as_echo "$as_me:$LINENO: result: yes" >&5
+$as_echo "yes" >&6; }
+
+cat >>confdefs.h <<\_ACEOF
+#define HAVE_INVALIDATE_INODES 1
+_ACEOF
+
+	fi
+
+
  ;;
                 user)
 
@@ -19029,6 +19070,47 @@ _ACEOF
 
 
 
+	{ $as_echo "$as_me:$LINENO: checking whether symbol invalidate_inodes is exported" >&5
+$as_echo_n "checking whether symbol invalidate_inodes is exported... " >&6; }
+	grep -q -E '[[:space:]]invalidate_inodes[[:space:]]' \
+		$LINUX_OBJ/Module*.symvers 2>/dev/null
+	rc=$?
+	if test $rc -ne 0; then
+		export=0
+		for file in ; do
+			grep -q -E "EXPORT_SYMBOL.*(invalidate_inodes)" \
+				"$LINUX_OBJ/$file" 2>/dev/null
+			rc=$?
+		        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_INVALIDATE_INODES 1
+_ACEOF
+
+		fi
+	else
+		{ $as_echo "$as_me:$LINENO: result: yes" >&5
+$as_echo "yes" >&6; }
+
+cat >>confdefs.h <<\_ACEOF
+#define HAVE_INVALIDATE_INODES 1
+_ACEOF
+
+	fi
+
+
+
 
 
 	if test "x$AWK" != xgawk; then