o Added ref counting to tables

o Further changes to new fs interface

driver/device-mapper/dm-fs.c

@@ -167,7 +167,7 @@ static int dmfs_release(struct inode *inode, struct file *f)
 
 	/* free off the old table */
 	if (table) {
-		dm_table_destroy(table);
+		dm_put_table(table);
 		inode->u.generic_ip = 0;
 	}
 
@@ -201,7 +201,7 @@ void dmfs_put_inode(struct inode *inode)
 
 	} else {
 		if (table)
-			dm_table_destroy(table);
+			dm_put_table(table);
 
 	}
 

driver/device-mapper/dm-parse.c

@@ -34,6 +34,9 @@ struct dm_table *dm_parse(extract_line_fn line_fn, void *l_private,
 	void *context;
 	int last_line_good = 1, was_error = 0;
 
+	if (table == NULL)
+		return NULL;
+
 #define PARSE_ERROR {last_line_good = 0; was_error = 1; continue;}
 
 	while (line_fn(&line, l_private)) {
@@ -114,7 +117,7 @@ struct dm_table *dm_parse(extract_line_fn line_fn, void *l_private,
 			return table;
 	}
 
-	dm_table_destroy(table);
+	dm_put_table(table);
 	return 0;
 }
 

driver/device-mapper/dm-table.c

@@ -127,6 +127,7 @@ struct dm_table *dm_table_create(void)
 
 	memset(t, 0, sizeof(*t));
 
+	atomic_set(&t->refcnt, 1);
 	atomic_set(&t->pending, 0);
 	init_waitqueue_head(&t->wait);
 
@@ -141,12 +142,12 @@ struct dm_table *dm_table_create(void)
 	return t;
 }
 
-void dm_table_destroy(struct dm_table *t)
+static void dm_table_destroy(struct dm_table *t)
 {
 	int i;
 
-	if (!t)
-		return;
+	if (atomic_read(&t->pending))
+		BUG();
 
 	/* free the indexes */
 	for (i = 0; i < t->depth - 1; i++) {
@@ -165,6 +166,12 @@ void dm_table_destroy(struct dm_table *t)
 	kfree(t);
 }
 
+void dm_put_table(struct dm_table *t)
+{
+	if (atomic_dec_and_test(&t->refcnt))
+		dm_table_destroy(t);
+}
+
 /*
  * checks to see if we need to extend highs or targets
  */

driver/device-mapper/dm.h

@@ -167,6 +167,8 @@ struct target {
  * the btree
  */
 struct dm_table {
+	atomic_t refcnt;
+
 	/* btree table */
 	int depth;
 	int counts[MAX_DEPTH];	/* in nodes */
@@ -226,7 +228,7 @@ void dm_suspend(struct mapped_device *md);
 
 /* dm-table.c */
 struct dm_table *dm_table_create(void);
-void dm_table_destroy(struct dm_table *t);
+void dm_put_table(struct dm_table *t);
 
 int dm_table_add_target(struct dm_table *t, offset_t high,
 			struct target_type *type, void *private);

driver/device-mapper/dmfs-lv.c

@@ -27,6 +27,7 @@
 static int dmfs_lv_create(struct inode *dir, struct dentry *dentry, int mode)
 {
 	struct inode *inode;
+	struct dm_table *table;
 
 	if (dentry->d_name.name[0] == '.')
 		return -EPERM;
@@ -37,16 +38,23 @@ static int dmfs_lv_create(struct inode *dir, struct dentry *dentry, int mode)
 
 	inode = dmfs_create_table(dir, dentry, mode)
 	if (!IS_ERR(inode)) {
-		d_instantiate(dentry, inode);
-		dget(dentry);
-		return 0;
+		table = dm_table_create();
+		if (table) {
+			d_instantiate(dentry, inode);
+			dget(dentry);
+			return 0;
+		}
+		iput(inode);
+		return -ENOMEM;
 	}
 	return PTR_ERR(inode);
 }
 
 static int dmfs_lv_unlink(struct inode *dir, struct dentry *dentry)
 {
-
+	inode->i_nlink--;
+	dput(dentry);
+	return 0;
 }
 
 static int dmfs_lv_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry)
@@ -59,6 +67,9 @@ static int dmfs_lv_link(struct dentry *old_dentry, struct inode *dir, struct den
 	if (dentry->d_parent != old_dentry->d_parent)
 		return -EPERM;
 
+	if (dentry->d_name[0] == '.')
+		return -EPERM;
+
 	inode->i_ctime = CURRENT_TIME;
 
 	return 0;

driver/device-mapper/dmfs-super.c

@@ -41,13 +41,16 @@ static void dmfs_delete_inode(struct inode *inode)
 		case S_IFDIR:
 			if (inode->u.generic_ip) {
 				dm_remove((struct mapped_device *)inode->u.generic_ip);
-				inode->u.generic_ip = NULL;
 			}
 			break;
 		case S_IFREG:
+			if (inode->u.generic_ip) {
+				dm_put_table((struct dm_table *)inode->u.generic_ip);
+			}
 			break;
 	}
 
+	inode->u.generic_ip = NULL;
 	clear_inode(inode);
 }