Simplify BDI integration

[zfs.git] / config / kernel-bdi-setup-and-register.m4

diff --git a/config/kernel-bdi-setup-and-register.m4 b/config/kernel-bdi-setup-and-register.m4
new file mode 100644 (file)
index 0000000..56fab87
--- /dev/null
+++ b/config/kernel-bdi-setup-and-register.m4
@@ -0,0 +1,15 @@
+dnl #
+dnl # 2.6.34 API change
+dnl # The bdi_setup_and_register() helper function is avilable and
+dnl # exported by the kernel.  This is a trivial helper function but
+dnl # using it significantly simplifies the code surrounding setting
+dnl # up and tearing down the bdi structure.
+dnl #
+AC_DEFUN([ZFS_AC_KERNEL_BDI_SETUP_AND_REGISTER], [
+       ZFS_CHECK_SYMBOL_EXPORT(
+               [bdi_setup_and_register],
+               [mm/backing-dev.c],
+               [AC_DEFINE(HAVE_BDI_SETUP_AND_REGISTER, 1,
+               [bdi_setup_and_register() is available])],
+               [])
+])