From 8f195a908ffaa8faf8f4c8a0e701e44ae3859e33 Mon Sep 17 00:00:00 2001
From: Yuxuan Shui <yshuiv7@gmail.com>
Date: Fri, 12 Oct 2012 22:41:06 +0800
Subject: [PATCH] Linux 3.6 compat, iops->lookup()

As of Linux commit 00cd8dd3bf95f2cc8435b4cac01d9995635c6d0b the
struct nameidata is no longer passed to iops->lookup.  Instead
only the inamedata->flags are passed.

ZFS like almost all Linux fileystems never made use of this so
only the prototype needs to be wrapped for compatibility.

Signed-off-by: Yuxuan Shui <yshuiv7@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #873
---
 config/kernel-lookup-nameidata.m4 | 21 +++++++++++++++++++++
 config/kernel.m4                  |  1 +
 module/zfs/zpl_ctldir.c           | 15 +++++++++++++++
 module/zfs/zpl_inode.c            |  4 ++++
 4 files changed, 41 insertions(+)
 create mode 100644 config/kernel-lookup-nameidata.m4

diff --git a/config/kernel-lookup-nameidata.m4 b/config/kernel-lookup-nameidata.m4
new file mode 100644
index 000000000..5e30be433
--- /dev/null
+++ b/config/kernel-lookup-nameidata.m4
@@ -0,0 +1,21 @@
+dnl #
+dnl # 3.6 API change
+dnl #
+AC_DEFUN([ZFS_AC_KERNEL_LOOKUP_NAMEIDATA], [
+	AC_MSG_CHECKING([whether iops->lookup() takes struct nameidata])
+	ZFS_LINUX_TRY_COMPILE([
+		#include <linux/fs.h>
+	],[
+		struct dentry * (*inode_lookup) (struct inode *,struct dentry *,
+		                     struct nameidata *) = NULL;
+		struct inode_operations iops __attribute__ ((unused)) = {
+			.lookup		= inode_lookup,
+		};
+	],[
+		AC_MSG_RESULT(yes)
+		AC_DEFINE(HAVE_LOOKUP_NAMEIDATA, 1,
+		          [iops->lookup() operation takes nameidata])
+	],[
+		AC_MSG_RESULT(no)
+	])
+])
diff --git a/config/kernel.m4 b/config/kernel.m4
index 3a144a337..8d8cd6b48 100644
--- a/config/kernel.m4
+++ b/config/kernel.m4
@@ -49,6 +49,7 @@ AC_DEFUN([ZFS_AC_CONFIG_KERNEL], [
 	ZFS_AC_KERNEL_NR_CACHED_OBJECTS
 	ZFS_AC_KERNEL_FREE_CACHED_OBJECTS
 	ZFS_AC_KERNEL_FALLOCATE
+	ZFS_AC_KERNEL_LOOKUP_NAMEIDATA
 	ZFS_AC_KERNEL_TRUNCATE_RANGE
 	ZFS_AC_KERNEL_CREATE_UMODE_T
 	ZFS_AC_KERNEL_AUTOMOUNT
diff --git a/module/zfs/zpl_ctldir.c b/module/zfs/zpl_ctldir.c
index c680e5443..7dfaf6ebc 100644
--- a/module/zfs/zpl_ctldir.c
+++ b/module/zfs/zpl_ctldir.c
@@ -143,7 +143,11 @@ zpl_root_getattr(struct vfsmount *mnt, struct dentry *dentry,
 }
 
 static struct dentry *
+#ifdef HAVE_LOOKUP_NAMEIDATA
 zpl_root_lookup(struct inode *dip, struct dentry *dentry, struct nameidata *nd)
+#else
+zpl_root_lookup(struct inode *dip, struct dentry *dentry, unsigned int flags)
+#endif
 {
 	cred_t *cr = CRED();
 	struct inode *ip;
@@ -180,8 +184,14 @@ const struct inode_operations zpl_ops_root = {
 };
 
 static struct dentry *
+#ifdef HAVE_LOOKUP_NAMEIDATA
 zpl_snapdir_lookup(struct inode *dip, struct dentry *dentry,
     struct nameidata *nd)
+#else
+zpl_snapdir_lookup(struct inode *dip, struct dentry *dentry,
+    unsigned int flags)
+#endif
+
 {
 	cred_t *cr = CRED();
 	struct inode *ip;
@@ -410,8 +420,13 @@ const struct dentry_operations zpl_dops_snapdirs = {
 #endif /* HAVE_AUTOMOUNT */
 
 static struct dentry *
+#ifdef HAVE_LOOKUP_NAMEIDATA
 zpl_shares_lookup(struct inode *dip, struct dentry *dentry,
     struct nameidata *nd)
+#else
+zpl_shares_lookup(struct inode *dip, struct dentry *dentry,
+    unsigned int flags)
+#endif
 {
 	cred_t *cr = CRED();
 	struct inode *ip = NULL;
diff --git a/module/zfs/zpl_inode.c b/module/zfs/zpl_inode.c
index 0dab82cc0..5b31c126c 100644
--- a/module/zfs/zpl_inode.c
+++ b/module/zfs/zpl_inode.c
@@ -31,7 +31,11 @@
 
 
 static struct dentry *
+#ifdef HAVE_LOOKUP_NAMEIDATA
 zpl_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
+#else
+zpl_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
+#endif
 {
 	cred_t *cr = CRED();
 	struct inode *ip;