+# LC_D_COMPARE_4ARGS
+#
+# Kernel version 4.8 commit 6fa67e707559303e086303aeecc9e8b91ef497d5
+# get rid of 'parent' argument of ->d_compare()
+#
+AC_DEFUN([LC_D_COMPARE_4ARGS], [
+LB_CHECK_COMPILE([if 'd_compare' taken 4 arguments],
+d_compare_4args, [
+ #include <linux/dcache.h>
+],[
+ ((struct dentry_operations*)0)->d_compare(NULL,0,NULL,NULL);
+],[
+ AC_DEFINE(HAVE_D_COMPARE_4ARGS, 1,
+ [d_compare need 4 arguments])
+])
+]) # LC_D_COMPARE_4ARGS
+
+#
+# LC_FULL_NAME_HASH_3ARGS
+#
+# Kernel version 4.8 commit 8387ff2577eb9ed245df9a39947f66976c6bcd02
+# vfs: make the string hashes salt the hash
+#
+AC_DEFUN([LC_FULL_NAME_HASH_3ARGS], [
+LB_CHECK_COMPILE([if 'full_name_hash' taken 3 arguments],
+full_name_hash_3args, [
+ #include <linux/stringhash.h>
+],[
+ unsigned int hash;
+ hash = full_name_hash(NULL,NULL,0);
+],[
+ AC_DEFINE(HAVE_FULL_NAME_HASH_3ARGS, 1,
+ [full_name_hash need 3 arguments])
+])
+]) # LC_FULL_NAME_HASH_3ARGS
+
+#
+# LC_STRUCT_POSIX_ACL_XATTR
+#
+# Kernel version 4.8 commit 2211d5ba5c6c4e972ba6dbc912b2897425ea6621
+# posix_acl: xattr representation cleanups
+#
+AC_DEFUN([LC_STRUCT_POSIX_ACL_XATTR], [
+LB_CHECK_COMPILE([if 'struct posix_acl_xattr_{header,entry}' defined],
+struct_posix_acl_xattr, [
+ #include <linux/fs.h>
+ #include <linux/posix_acl_xattr.h>
+],[
+ struct posix_acl_xattr_header *h = NULL;
+ struct posix_acl_xattr_entry *e;
+ e = (void *)(h + 1);
+],[
+ AC_DEFINE(HAVE_STRUCT_POSIX_ACL_XATTR, 1,
+ [struct posix_acl_xattr_{header,entry} defined])
+])
+]) # LC_STRUCT_POSIX_ACL_XATTR
+
+#
+# LC_IOP_XATTR
+#
+# Kernel version 4.8 commit fd50ecaddf8372a1d96e0daeaac0f93cf04e4d42
+# removed {get,set,remove}xattr inode operations
+#
+AC_DEFUN([LC_IOP_XATTR], [
+LB_CHECK_COMPILE([if 'inode_operations' has {get,set,remove}xattr members],
+inode_ops_xattr, [
+ #include <linux/fs.h>
+],[
+ struct inode_operations iop;
+ iop.setxattr = NULL;
+ iop.getxattr = NULL;
+ iop.removexattr = NULL;
+],[
+ AC_DEFINE(HAVE_IOP_XATTR, 1,
+ [inode_operations has {get,set,remove}xattr members])
+])
+]) # LC_IOP_XATTR
+
+#
+# LC_GROUP_INFO_GID
+#
+# Kernel version 4.9 commit 81243eacfa400f5f7b89f4c2323d0de9982bb0fb
+# cred: simpler, 1D supplementary groups
+#
+AC_DEFUN([LC_GROUP_INFO_GID], [
+LB_CHECK_COMPILE([if 'struct group_info' has member 'gid'],
+group_info_gid, [
+ #include <linux/cred.h>
+],[
+ kgid_t *p;
+ p = ((struct group_info *)0)->gid;
+],[
+ AC_DEFINE(HAVE_GROUP_INFO_GID, 1,
+ [struct group_info has member gid])
+])
+]) # LC_GROUP_INFO_GID
+
+#
+# LC_VFS_SETXATTR
+#
+# Kernel version 4.9 commit 5d6c31910bc0713e37628dc0ce677dcb13c8ccf4
+# added __vfs_{get,set,remove}xattr helpers
+#
+AC_DEFUN([LC_VFS_SETXATTR], [
+LB_CHECK_COMPILE([if '__vfs_setxattr' helper is available],
+vfs_setxattr, [
+ #include <linux/xattr.h>
+],[
+ __vfs_setxattr(NULL, NULL, NULL, NULL, 0, 0);
+],[
+ AC_DEFINE(HAVE_VFS_SETXATTR, 1,
+ ['__vfs_setxattr is available])
+])
+]) # LC_VFS_SETXATTR
+
+#
+# LC_IOP_GENERIC_READLINK
+#
+# Kernel version 4.10 commit dfeef68862edd7d4bafe68ef7aeb5f658ef24bb5
+# removed generic_readlink from individual file systems
+#
+AC_DEFUN([LC_IOP_GENERIC_READLINK], [
+LB_CHECK_COMPILE([if 'generic_readlink' still exist],
+inode_ops_readlink, [
+ #include <linux/fs.h>
+],[
+ struct inode_operations iop;
+ iop.readlink = generic_readlink;
+],[
+ AC_DEFINE(HAVE_IOP_GENERIC_READLINK, 1,
+ [generic_readlink has been removed])
+])
+]) # LC_IOP_GENERIC_READLINK
+
+#
+# LC_HAVE_VM_FAULT_ADDRESS
+#
+# Kernel version 4.10 commit 1a29d85eb0f19b7d8271923d8917d7b4f5540b3e
+# removed virtual_address field. Need to use address field instead
+#
+AC_DEFUN([LC_HAVE_VM_FAULT_ADDRESS], [
+LB_CHECK_COMPILE([if 'struct vm_fault' replaced virtual_address with address field],
+vm_fault_address, [
+ #include <linux/mm.h>
+],[
+ struct vm_fault vmf;
+ vmf.address = NULL;
+],[
+ AC_DEFINE(HAVE_VM_FAULT_ADDRESS, 1,
+ [virtual_address has been replaced by address field])
+])
+]) # LC_HAVE_VM_FAULT_ADDRESS
+
+#
+# LC_INODEOPS_ENHANCED_GETATTR
+#
+# Kernel version 4.11 commit a528d35e8bfcc521d7cb70aaf03e1bd296c8493f
+# expanded getattr to be able to get more stat information.
+#
+AC_DEFUN([LC_INODEOPS_ENHANCED_GETATTR], [
+LB_CHECK_COMPILE([if 'inode_operations' getattr member can gather advance stats],
+getattr_path, [
+ #include <linux/fs.h>
+],[
+ struct path path;
+
+ ((struct inode_operations *)1)->getattr(&path, NULL, 0, 0);
+],[
+ AC_DEFINE(HAVE_INODEOPS_ENHANCED_GETATTR, 1,
+ [inode_operations .getattr member function can gather advance stats])
+])
+]) # LC_INODEOPS_ENHANCED_GETATTR
+
+#
+# LC_VM_OPERATIONS_REMOVE_VMF_ARG
+#
+# Kernel version 4.11 commit 11bac80004499ea59f361ef2a5516c84b6eab675
+# removed struct vm_area_struct as an argument for vm_operations since
+# in the same kernel version struct vma_area_struct was folded into
+# struct vm_fault.
+#
+AC_DEFUN([LC_VM_OPERATIONS_REMOVE_VMF_ARG], [
+LB_CHECK_COMPILE([if 'struct vm_operations' removed struct vm_area_struct],
+vm_operations_no_vm_area_struct, [
+ #include <linux/mm.h>
+],[
+ struct vm_fault vmf;
+
+ ((struct vm_operations_struct *)0)->fault(&vmf);
+ ((struct vm_operations_struct *)0)->page_mkwrite(&vmf);
+],[
+ AC_DEFINE(HAVE_VM_OPS_USE_VM_FAULT_ONLY, 1,
+ ['struct vm_operations' remove struct vm_area_struct argument])
+])
+]) # LC_VM_OPERATIONS_REMOVE_VMF_ARG
+
+#
+# Kernel version 4.12 commit 47f38c539e9a42344ff5a664942075bd4df93876
+# CURRENT_TIME is not 64 bit time safe so it was replaced with
+# current_time()
+#
+AC_DEFUN([LC_CURRENT_TIME], [
+LB_CHECK_COMPILE([if CURRENT_TIME has been replaced with current_time],
+current_time, [
+ #include <linux/fs.h>
+],[
+ struct timespec ts = current_time(NULL);
+],[
+ AC_DEFINE(HAVE_CURRENT_TIME, 1,
+ [current_time() has replaced CURRENT_TIME])
+])
+]) # LIBCFS_CURRENT_TIME
+
+#