JFS: support for kNFSD

Add support for the get_parent export operation to make nfs exporting
work on 2.5.
Switch to the new iget_locked and eliminate ->read_inode.

Submitted by Christoph Hellwig, and Dave Kleikamp

fs/jfs/inode.c

@@ -34,17 +34,18 @@ extern struct file_operations jfs_file_operations;
 struct address_space_operations jfs_aops;
 extern int freeZeroLink(struct inode *);
 
-void jfs_put_inode(struct inode *inode)
+struct inode *jfs_iget(struct super_block *sb, ino_t ino)
 {
-	jFYI(1, ("In jfs_put_inode, inode = 0x%p\n", inode));
-}
+	struct inode *inode = iget_locked(sb, ino);
 
-void jfs_read_inode(struct inode *inode)
-{
-	jFYI(1, ("In jfs_read_inode, inode = 0x%p\n", inode));
+	if (!inode || !(inode->i_state & I_NEW))
+		return inode;
 
-	if (diRead(inode))
-		goto bad_inode;
+	if (diRead(inode)) { 
+		make_bad_inode(inode);
+		unlock_new_inode(inode);
+		return NULL;
+	}
 
 	if (S_ISREG(inode->i_mode)) {
 		inode->i_op = &jfs_file_inode_operations;
@@ -65,11 +66,8 @@ void jfs_read_inode(struct inode *inode)
 		init_special_inode(inode, inode->i_mode,
 				   kdev_t_to_nr(inode->i_rdev));
 	}
-
-	return;
-
-      bad_inode:
-	make_bad_inode(inode);
+	unlock_new_inode(inode);
+	return inode;
 }
 
 /* This define is from fs/open.c */

fs/jfs/namei.c

@@ -32,6 +32,7 @@ extern struct address_space_operations jfs_aops;
 
 extern int jfs_fsync(struct file *, struct dentry *, int);
 extern void jfs_truncate_nolock(struct inode *, loff_t);
+extern struct inode *jfs_iget(struct super_block *, ino_t);
 
 /*
  * forward references
@@ -1410,7 +1411,7 @@ static struct dentry *jfs_lookup(struct inode *dip, struct dentry *dentry)
 		}
 	}
 
-	ip = iget(dip->i_sb, inum);
+	ip = jfs_iget(dip->i_sb, inum);
 	if (ip == NULL) {
 		jERROR(1,
 		       ("jfs_lookup: iget failed on inum %d\n",
@@ -1418,9 +1419,25 @@ static struct dentry *jfs_lookup(struct inode *dip, struct dentry *dentry)
 		return ERR_PTR(-EACCES);
 	}
 
-	d_add(dentry, ip);
+	return d_splice_alias(ip, dentry);
+}
+
+struct dentry *jfs_get_parent(struct dentry *dentry)
+{
+	struct super_block *sb = dentry->d_inode->i_sb;
+	struct dentry *parent = ERR_PTR(-EACCES);
+	struct inode *inode;
+
+	inode = jfs_iget(sb, JFS_IP(dentry->d_inode)->i_dtroot.header.idotdot);
+	if (inode) {
+		parent = d_alloc_anon(inode);
+		if (!parent) {
+			parent = ERR_PTR(-ENOMEM);
+			iput(inode);
+		}
+	}
 
-	return ERR_PTR(0);
+	return parent;
 }
 
 struct inode_operations jfs_dir_inode_operations = {

fs/jfs/super.c

@@ -53,6 +53,8 @@ MODULE_PARM_DESC(jfsloglevel, "Specify JFS loglevel (0, 1 or 2)");
 /*
  * External declarations
  */
+extern struct inode *jfs_iget(struct super_block *, ino_t);
+
 extern int jfs_mount(struct super_block *);
 extern int jfs_mount_rw(struct super_block *, int);
 extern int jfs_umount(struct super_block *);
@@ -61,12 +63,13 @@ extern int jfs_umount_rw(struct super_block *);
 extern int jfsIOWait(void *);
 extern int jfs_lazycommit(void *);
 extern int jfs_sync(void *);
-extern void jfs_put_inode(struct inode *inode);
-extern void jfs_read_inode(struct inode *inode);
+
 extern void jfs_dirty_inode(struct inode *inode);
 extern void jfs_delete_inode(struct inode *inode);
 extern void jfs_write_inode(struct inode *inode, int wait);
 
+extern struct dentry *jfs_get_parent(struct dentry *dentry);
+
 #if defined(CONFIG_JFS_DEBUG) && defined(CONFIG_PROC_FS)
 extern void jfs_proc_init(void);
 extern void jfs_proc_clean(void);
@@ -232,19 +235,21 @@ int jfs_remount(struct super_block *sb, int *flags, char *data)
 	return 0;
 }
 
-static struct super_operations jfs_sops = {
+static struct super_operations jfs_super_operations = {
 	alloc_inode:	jfs_alloc_inode,
 	destroy_inode:	jfs_destroy_inode,
-	read_inode:	jfs_read_inode,
 	dirty_inode:	jfs_dirty_inode,
 	write_inode:	jfs_write_inode,
-	put_inode:	jfs_put_inode,
 	delete_inode:	jfs_delete_inode,
 	put_super:	jfs_put_super,
 	statfs:		jfs_statfs,
 	remount_fs:	jfs_remount,
 };
 
+static struct export_operations jfs_export_operations = {
+	get_parent:	jfs_get_parent,
+};
+
 static int jfs_fill_super(struct super_block *sb, void *data, int silent)
 {
 	struct jfs_sb_info *sbi;
@@ -268,7 +273,13 @@ static int jfs_fill_super(struct super_block *sb, void *data, int silent)
 	 * Initialize blocksize to 4K.
 	 */
 	sb_set_blocksize(sb, PSIZE);
-	sb->s_op = &jfs_sops;
+
+	/*
+	 * Set method vectors.
+	 */
+	sb->s_op = &jfs_super_operations;
+	sb->s_export_op = &jfs_export_operations;
+
 	/*
 	 * Initialize direct-mapping inode/address-space
 	 */
@@ -309,7 +320,7 @@ static int jfs_fill_super(struct super_block *sb, void *data, int silent)
 
 	sb->s_magic = JFS_SUPER_MAGIC;
 
-	inode = iget(sb, ROOT_I);
+	inode = jfs_iget(sb, ROOT_I);
 	if (!inode || is_bad_inode(inode))
 		goto out_no_root;
 	sb->s_root = d_alloc_root(inode);