+#
+# LC_NFS_FILLDIR_USE_CTX
+#
+# 3.18 kernel moved from void cookie to struct dir_context
+#
+AC_DEFUN([LC_NFS_FILLDIR_USE_CTX], [
+tmp_flags="$EXTRA_KCFLAGS"
+EXTRA_KCFLAGS="-Werror"
+LB_CHECK_COMPILE([if filldir_t uses struct dir_context],
+filldir_ctx, [
+ #include <linux/fs.h>
+],[
+ int filldir(struct dir_context *ctx, const char* name,
+ int i, loff_t off, u64 tmp, unsigned temp)
+ {
+ return 0;
+ }
+
+ struct dir_context ctx = {
+ .actor = filldir,
+ };
+
+ ctx.actor(NULL, "test", 0, (loff_t) 0, 0, 0);
+],[
+ AC_DEFINE(HAVE_FILLDIR_USE_CTX, 1,
+ [filldir_t needs struct dir_context as argument])
+])
+EXTRA_KCFLAGS="$tmp_flags"
+]) # LC_NFS_FILLDIR_USE_CTX
+
+#
+# LC_PERCPU_COUNTER_INIT
+#
+# 3.18 For kernels 3.18 and after percpu_counter_init starts
+# to pass a GFP_* memory allocation flag for internal
+# memory allocation purposes.
+#
+AC_DEFUN([LC_PERCPU_COUNTER_INIT], [
+LB_CHECK_COMPILE([if percpu_counter_init uses GFP_* flag as argument],
+percpu_counter_init, [
+ #include <linux/percpu_counter.h>
+],[
+ percpu_counter_init(NULL, 0, GFP_KERNEL);
+],[
+ AC_DEFINE(HAVE_PERCPU_COUNTER_INIT_GFP_FLAG, 1,
+ [percpu_counter_init uses GFP_* flag])
+])
+]) # LC_PERCPU_COUNTER_INIT
+
+#
+# LC_KIOCB_HAS_NBYTES
+#
+# 3.19 kernel removed ki_nbytes from struct kiocb
+#
+AC_DEFUN([LC_KIOCB_HAS_NBYTES], [
+LB_CHECK_COMPILE([if struct kiocb has ki_nbytes field],
+ki_nbytes, [
+ #include <linux/fs.h>
+],[
+ struct kiocb iocb;
+
+ iocb.ki_nbytes = 0;
+],[
+ AC_DEFINE(HAVE_KI_NBYTES, 1, [ki_nbytes field exist])
+])
+]) # LC_KIOCB_HAS_NBYTES
+
+#
+# LC_BACKING_DEV_INFO_REMOVAL
+#
+# 3.20 kernel removed backing_dev_info from address_space
+#
+AC_DEFUN([LC_BACKING_DEV_INFO_REMOVAL], [
+LB_CHECK_COMPILE([if struct address_space has backing_dev_info],
+backing_dev_info, [
+ #include <linux/fs.h>
+],[
+ struct address_space mapping;
+
+ mapping.backing_dev_info = NULL;
+],[
+ AC_DEFINE(HAVE_BACKING_DEV_INFO, 1, [backing_dev_info exist])
+])
+]) # LC_BACKING_DEV_INFO_REMOVAL
+
+#
+# LC_HAVE_BDI_CAP_MAP_COPY
+#
+# 3.20 removed mmap handling for backing devices since
+# it breaks on non-MMU systems. See kernel commit
+# b4caecd48005fbed3949dde6c1cb233142fd69e9
+#
+AC_DEFUN([LC_HAVE_BDI_CAP_MAP_COPY], [
+LB_CHECK_COMPILE([if have 'BDI_CAP_MAP_COPY'],
+bdi_cap_map_copy, [
+ #include <linux/backing-dev.h>
+],[
+ struct backing_dev_info info;
+
+ info.capabilities = BDI_CAP_MAP_COPY;
+],[
+ AC_DEFINE(HAVE_BDI_CAP_MAP_COPY, 1,
+ [BDI_CAP_MAP_COPY exist])
+])
+]) # LC_HAVE_BDI_CAP_MAP_COPY
+
+#
+# LC_CANCEL_DIRTY_PAGE
+#
+# 4.0.0 kernel removed cancel_dirty_page
+#
+AC_DEFUN([LC_CANCEL_DIRTY_PAGE], [
+LB_CHECK_COMPILE([if cancel_dirty_page still exist],
+cancel_dirty_page, [
+ #include <linux/mm.h>
+],[
+ cancel_dirty_page(NULL, PAGE_SIZE);
+],[
+ AC_DEFINE(HAVE_CANCEL_DIRTY_PAGE, 1,
+ [cancel_dirty_page is still available])
+])
+]) # LC_CANCEL_DIRTY_PAGE
+
+#
+# LC_IOV_ITER_RW
+#
+# 4.1 kernel has iov_iter_rw
+#
+AC_DEFUN([LC_IOV_ITER_RW], [
+LB_CHECK_COMPILE([if iov_iter_rw exist],
+iov_iter_rw, [
+ #include <linux/fs.h>
+ #include <linux/uio.h>
+],[
+ struct iov_iter *iter = NULL;
+
+ iov_iter_rw(iter);
+],[
+ AC_DEFINE(HAVE_IOV_ITER_RW, 1,
+ [iov_iter_rw exist])
+])
+]) # LC_IOV_ITER_RW
+
+#
+# LC_HAVE_SYNC_READ_WRITE
+#
+# 4.1 new_sync_[read|write] no longer exported
+#
+AC_DEFUN([LC_HAVE_SYNC_READ_WRITE], [
+LB_CHECK_EXPORT([new_sync_read], [fs/read_write.c],
+ [AC_DEFINE(HAVE_SYNC_READ_WRITE, 1,
+ [new_sync_[read|write] is exported by the kernel])])
+]) # LC_HAVE_SYNC_READ_WRITE
+
+#
+# LC_NEW_CANCEL_DIRTY_PAGE
+#
+# 4.2 kernel has new cancel_dirty_page
+#
+AC_DEFUN([LC_NEW_CANCEL_DIRTY_PAGE], [
+LB_CHECK_COMPILE([if cancel_dirty_page with one argument exist],
+new_cancel_dirty_page, [
+ #include <linux/mm.h>
+],[
+ cancel_dirty_page(NULL);
+],[
+ AC_DEFINE(HAVE_NEW_CANCEL_DIRTY_PAGE, 1,
+ [cancel_dirty_page with one arguement is available])
+])
+]) # LC_NEW_CANCEL_DIRTY_PAGE
+
+#
+# LC_SYMLINK_OPS_USE_NAMEIDATA
+#
+# For the 4.2+ kernels the file system internal symlink api no
+# longer uses struct nameidata as a argument
+#
+AC_DEFUN([LC_SYMLINK_OPS_USE_NAMEIDATA], [
+LB_CHECK_COMPILE([if symlink inode operations have struct nameidata argument],
+symlink_use_nameidata, [
+ #include <linux/namei.h>
+ #include <linux/fs.h>
+],[
+ struct nameidata *nd = NULL;
+
+ ((struct inode_operations *)0)->follow_link(NULL, nd);
+ ((struct inode_operations *)0)->put_link(NULL, nd, NULL);
+],[
+ AC_DEFINE(HAVE_SYMLINK_OPS_USE_NAMEIDATA, 1,
+ [symlink inode operations need struct nameidata argument])
+])
+]) # LC_SYMLINK_OPS_USE_NAMEIDATA
+
+#
+# LC_BIO_ENDIO_USES_ONE_ARG
+#
+# 4.2 kernel bio_endio now only takes one argument
+#
+AC_DEFUN([LC_BIO_ENDIO_USES_ONE_ARG], [
+LB_CHECK_COMPILE([if 'bio_endio' with one argument exist],
+bio_endio, [
+ #include <linux/bio.h>
+],[
+ bio_endio(NULL);
+],[
+ AC_DEFINE(HAVE_BIO_ENDIO_USES_ONE_ARG, 1,
+ [bio_endio takes only one argument])