File aufs-nfs4-is-special of Package aufs

From: Jeff Mahoney <jeffm@suse.com>
Subject: aufs: Handle NFSv4 enablement separately from NFSv2/3

 NFSv4's atomic opens require that a nameidata be passed down
 into __lookup_hash, which isn't exported. However, NFSv2/3
 can be supported with just lookup_one_len.

 This patch handles NFSv4 enablement separately and will
 enable NFSv2/3 support if __lookup_hash isn't exported, and
 addtionally enable NFSv4 if it is.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
---
 fs/aufs25/branch.c              |    2 +-
 fs/aufs25/branch.h              |   15 +++++++++++----
 fs/aufs25/vfsub.c               |   10 ++++++----
 fs/aufs25/vfsub.h               |    2 --
 local.mk                        |    6 +++++-
 patch/release_open_intent.patch |   14 ++++++++++++++
 6 files changed, 37 insertions(+), 12 deletions(-)

--- a/fs/aufs25/branch.c
+++ b/fs/aufs25/branch.c
@@ -393,7 +393,7 @@ static int test_add(struct super_block *
 		goto out;
 	}
 
-	if (unlikely(au_test_unsupported_nfs(inode->i_sb))) {
+	if (unlikely(au_test_unsupported_nfs(inode))) {
 		AuErr(AuNoNfsBranchMsg " %s\n", add->path);
 		goto out;
 	}
--- a/fs/aufs25/branch.h
+++ b/fs/aufs25/branch.h
@@ -28,6 +28,7 @@
 #ifdef __KERNEL__
 
 #include <linux/fs.h>
+#include <linux/nfs_fs.h>
 #include <linux/mount.h>
 #include <linux/sysfs.h>
 #include <linux/aufs_type.h>
@@ -350,9 +351,14 @@ static inline void au_br_nfs_lockdep_on(
 }
 
 #ifdef CONFIG_AUFS_BR_NFS
-static inline int au_test_unsupported_nfs(struct super_block *h_sb)
+static inline int au_test_unsupported_nfs(struct inode *h_inode)
 {
+#ifdef CONFIG_AUFS_BR_NFS4
 	return 0;
+#else
+	return h_inode->i_sb->s_magic == NFS_SUPER_MAGIC &&
+	       NFS_PROTO(h_inode)->version == 4;
+#endif
 }
 
 /* it doesn't mntget() */
@@ -362,12 +368,13 @@ struct vfsmount *au_nfsmnt(struct super_
 	return au_do_nfsmnt(au_sbr_mnt(sb, bindex));
 }
 
-#define AuNoNfsBranchMsg "dummy"
+#define AuNoNfsBranchMsg "NFSv4 branch is not supported" \
+	", try some configurations and patches included in aufs source CVS."
 
 #else
-static inline int au_test_unsupported_nfs(struct super_block *h_sb)
+static inline int au_test_unsupported_nfs(struct inode *h_inode)
 {
-	return h_sb->s_magic == NFS_SUPER_MAGIC;
+	return h_inode->i_sb->s_magic == NFS_SUPER_MAGIC;
 }
 
 static inline
--- a/fs/aufs25/vfsub.c
+++ b/fs/aufs25/vfsub.c
@@ -84,7 +84,6 @@ struct dentry *vfsub_lookup_one_len(cons
 	return d;
 }
 
-#ifdef CONFIG_AUFS_LHASH_PATCH
 struct dentry *vfsub__lookup_hash(struct qstr *name, struct dentry *parent,
 				  struct nameidata *nd)
 {
@@ -92,16 +91,19 @@ struct dentry *vfsub__lookup_hash(struct
 
 	LKTRTrace("%.*s/%.*s, nd %d\n",
 		  AuDLNPair(parent), AuLNPair(name), !!nd);
-	if (nd)
-		LKTRTrace("nd{0x%x}\n", nd->flags);
+#ifdef CONFIG_AUFS_LHASH_PATCH
+	BUG_ON(!nd);
+	LKTRTrace("nd{0x%x}\n", nd->flags);
 	IMustLock(parent->d_inode);
 
 	d = __lookup_hash(name, parent, nd);
 	if (!IS_ERR(d))
 		au_update_fuse_h_inode(NULL, d); /*ignore*/
+#else
+	d = vfsub_lookup_one_len(name->name, parent, name->len);
+#endif
 	return d;
 }
-#endif
 
 /* ---------------------------------------------------------------------- */
 
--- a/fs/aufs25/vfsub.h
+++ b/fs/aufs25/vfsub.h
@@ -250,10 +250,8 @@ int vfsub_path_lookup(const char *name,
 struct dentry *vfsub_lookup_one_len(const char *name, struct dentry *parent,
 				    int len);
 
-#ifdef CONFIG_AUFS_LHASH_PATCH
 struct dentry *vfsub__lookup_hash(struct qstr *name, struct dentry *parent,
 				  struct nameidata *nd);
-#endif
 
 /* ---------------------------------------------------------------------- */
 
--- a/local.mk
+++ b/local.mk
@@ -61,8 +61,12 @@ AUFS_DEF_CONFIG =
 # automatic configurations
 
 export CONFIG_AUFS_BR_NFS =
+export CONFIG_AUFS_BR_NFS4 =
 ifdef CONFIG_NFS_FS
 CONFIG_AUFS_BR_NFS = y
+ifdef CONFIG_NFS_V4
+CONFIG_AUFS_BR_NFS4 = y
+endif
 ifeq "t" "$(shell test ${SUBLEVEL} -lt 16 && echo t)"
 CONFIG_AUFS_BR_NFS =
 else ifeq "t" "$(shell test ${SUBLEVEL} -ge 19 \
@@ -71,7 +75,7 @@ else ifeq "t" "$(shell test ${SUBLEVEL}
 			-o x${CONFIG_AUFS_PUT_FILP_PATCH} = xy \) \
 		\) \
 	&& echo t)"
-CONFIG_AUFS_BR_NFS =
+CONFIG_AUFS_BR_NFS4 =
 endif
 endif
 
--- /dev/null
+++ b/patch/release_open_intent.patch
@@ -0,0 +1,14 @@
+---
+ fs/namei.c |    1 +
+ 1 file changed, 1 insertion(+)
+
+--- a/fs/namei.c
++++ b/fs/namei.c
+@@ -410,6 +410,7 @@ void release_open_intent(struct nameidat
+ 	else
+ 		fput(nd->intent.open.file);
+ }
++EXPORT_SYMBOL_GPL(release_open_intent);
+ 
+ static inline struct dentry *
+ do_revalidate(struct dentry *dentry, struct nameidata *nd)