From: Peter Staubach <staubach@redhat.com>
Date: Fri, 18 Jan 2008 15:15:55 -0500
Subject: [fs] manually d_move inside of rename()
Message-id: 479108FB.60603@redhat.com
O-Subject: [RHEL5.2 PATCH] Backport patch from 2.6.19 allowing fs' to manually d_move() inside of ->rename()
Bugzilla: 427472

Hi.

Attached is a patch to address bz427472, "Backport patch from
2.6.19 allowing fs' to manually d_move() inside of ->rename()".

This patch allows a file system to better control when the
dcache is updated during a rename operation.  The NFS code
implemented a particular solution, but this wasn't quite
sufficient for OCFS, so they have requested a variation of it.
Thus, both NFS and the VFS code was updated to reflect the
new requirements and implementation.

The patch was committed upstream and has been tested there by
the OCFS folks.

    Thanx...

       ps

Acked-by: Steve Dickson <SteveD@redhat.com>
Acked-by: Jeff Layton <jlayton@redhat.com>

diff --git a/fs/namei.c b/fs/namei.c
index cece729..6b99c47 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2397,7 +2397,8 @@ static int vfs_rename_dir(struct inode *old_dir, struct dentry *old_dentry,
 		dput(new_dentry);
 	}
 	if (!error)
-		d_move(old_dentry,new_dentry);
+		if (!(old_dir->i_sb->s_type->fs_flags & FS_RENAME_DOES_D_MOVE))
+			d_move(old_dentry,new_dentry);
 	return error;
 }
 
@@ -2420,8 +2421,7 @@ static int vfs_rename_other(struct inode *old_dir, struct dentry *old_dentry,
 	else
 		error = old_dir->i_op->rename(old_dir, old_dentry, new_dir, new_dentry);
 	if (!error) {
-		/* The following d_move() should become unconditional */
-		if (!(old_dir->i_sb->s_type->fs_flags & FS_ODD_RENAME))
+		if (!(old_dir->i_sb->s_type->fs_flags & FS_RENAME_DOES_D_MOVE))
 			d_move(old_dentry, new_dentry);
 	}
 	if (target)
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index bf2a8b2..48452eb 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -1670,8 +1670,7 @@ out:
 	if (rehash)
 		d_rehash(rehash);
 	if (!error) {
-		if (!S_ISDIR(old_inode->i_mode))
-			d_move(old_dentry, new_dentry);
+		d_move(old_dentry, new_dentry);
 		nfs_set_verifier(new_dentry, nfs_save_change_attribute(new_dir));
 	}
 
diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index 753508d..9427062 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -71,7 +71,7 @@ static struct file_system_type nfs_fs_type = {
 	.name		= "nfs",
 	.get_sb		= nfs_get_sb,
 	.kill_sb	= nfs_kill_super,
-	.fs_flags	= FS_ODD_RENAME|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
+	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 };
 
 struct file_system_type nfs_xdev_fs_type = {
@@ -79,7 +79,7 @@ struct file_system_type nfs_xdev_fs_type = {
 	.name		= "nfs",
 	.get_sb		= nfs_xdev_get_sb,
 	.kill_sb	= nfs_kill_super,
-	.fs_flags	= FS_ODD_RENAME|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
+	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 };
 
 static struct super_operations nfs_sops = {
@@ -108,7 +108,7 @@ static struct file_system_type nfs4_fs_type = {
 	.name		= "nfs4",
 	.get_sb		= nfs4_get_sb,
 	.kill_sb	= nfs4_kill_super,
-	.fs_flags	= FS_ODD_RENAME|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
+	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 };
 
 struct file_system_type nfs4_xdev_fs_type = {
@@ -116,7 +116,7 @@ struct file_system_type nfs4_xdev_fs_type = {
 	.name		= "nfs4",
 	.get_sb		= nfs4_xdev_get_sb,
 	.kill_sb	= nfs4_kill_super,
-	.fs_flags	= FS_ODD_RENAME|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
+	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 };
 
 struct file_system_type nfs4_referral_fs_type = {
@@ -124,7 +124,7 @@ struct file_system_type nfs4_referral_fs_type = {
 	.name		= "nfs4",
 	.get_sb		= nfs4_referral_get_sb,
 	.kill_sb	= nfs4_kill_super,
-	.fs_flags	= FS_ODD_RENAME|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
+	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 };
 
 static struct super_operations nfs4_sops = {
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 3423d23..6644592 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -92,9 +92,10 @@ extern int dir_notify_enable;
 #define FS_REQUIRES_DEV 1 
 #define FS_BINARY_MOUNTDATA 2
 #define FS_REVAL_DOT	16384	/* Check the paths ".", ".." for staleness */
-#define FS_ODD_RENAME	32768	/* Temporary stuff; will go away as soon
-				  * as nfs_rename() will be cleaned up
-				  */
+#define FS_RENAME_DOES_D_MOVE	32768	/* FS will handle d_move()
+					 * during rename() internally.
+					 */
+
 /*
  * These are the fs-independent mount-flags: up to 32 flags are supported
  */