fs: cleanup backingstore handling

All filesystem drivers which need a backingstore device do the same
ignoring of '/dev/' in the backingstore followed by a cdev_open. Add a
helper function for it and let the core handle the cdev. As a side
effect this makes sure that fsdev->cdev is also set when a device is
mounted without the leading '/dev/' which was previously ignored
by the mount code.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

fs/cramfs/cramfs.c

@@ -422,29 +422,33 @@ static int cramfs_probe(struct device_d *dev)
 {
 	struct fs_device_d *fsdev;
 	struct cramfs_priv *priv;
+	int ret;
 
 	fsdev = dev_to_fs_device(dev);
 
 	priv = xmalloc(sizeof(struct cramfs_priv));
 	dev->priv = priv;
 
-	if (strncmp(fsdev->backingstore, "/dev/", 5))
-		return -ENODEV;
+	ret = fsdev_open_cdev(fsdev);
+	if (ret)
+		goto err_out;
 
-	priv->cdev = cdev_by_name(fsdev->backingstore + 5);
-	if (!priv->cdev)
-		return -ENODEV;
+	priv->cdev = fsdev->cdev;
 
 	if (cramfs_read_super(priv)) {
 		dev_info(dev, "no valid cramfs found\n");
-		free(priv);
-		return -EINVAL;
+		ret =  -EINVAL;
 	}
 
 	priv->curr_base = -1;
 
 	cramfs_uncompress_init ();
 	return 0;
+
+err_out:
+	free(priv);
+
+	return ret;
 }
 
 static void cramfs_remove(struct device_d *dev)

fs/ext4/ext_barebox.c

@@ -225,7 +225,6 @@ static int ext_readlink(struct device_d *dev, const char *pathname,
 static int ext_probe(struct device_d *dev)
 {
 	struct fs_device_d *fsdev = dev_to_fs_device(dev);
-	char *backingstore = fsdev->backingstore;
 	int ret;
 	struct ext_filesystem *fs;
 
@@ -234,14 +233,11 @@ static int ext_probe(struct device_d *dev)
 	dev->priv = fs;
 	fs->dev = dev;
 
-	if (!strncmp(backingstore , "/dev/", 5))
-		backingstore += 5;
-
-	fs->cdev = cdev_open(backingstore, O_RDWR);
-	if (!fs->cdev) {
-		ret = -ENOENT;
+	ret = fsdev_open_cdev(fsdev);
+	if (ret)
 		goto err_open;
-	}
+
+	fs->cdev = fsdev->cdev;
 
 	ret = ext4fs_mount(fs);
 	if (ret)
@@ -250,7 +246,6 @@ static int ext_probe(struct device_d *dev)
 	return 0;
 
 err_mount:
-	cdev_close(fs->cdev);
 err_open:
 	free(fs);
 
@@ -262,7 +257,6 @@ static void ext_remove(struct device_d *dev)
 	struct ext_filesystem *fs = dev->priv;
 
 	ext4fs_umount(fs);
-	cdev_close(fs->cdev);
 	free(fs);
 }
 

fs/fat/fat.c

@@ -373,19 +373,15 @@ static int fat_probe(struct device_d *dev)
 {
 	struct fs_device_d *fsdev = dev_to_fs_device(dev);
 	struct fat_priv *priv = xzalloc(sizeof(struct fat_priv));
-	char *backingstore = fsdev->backingstore;
 	int ret;
 
 	dev->priv = priv;
 
-	if (!strncmp(backingstore , "/dev/", 5))
-		backingstore += 5;
-
-	priv->cdev = cdev_open(backingstore, O_RDWR);
-	if (!priv->cdev) {
-		ret = -ENOENT;
+	ret = fsdev_open_cdev(fsdev);
+	if (ret)
 		goto err_open;
-	}
+
+	priv->cdev = fsdev->cdev;
 
 	priv->fat.userdata = priv;
 	ret = f_mount(&priv->fat);
@@ -395,7 +391,6 @@ static int fat_probe(struct device_d *dev)
 	return 0;
 
 err_mount:
-	cdev_close(priv->cdev);
 err_open:
 	free(priv);
 
@@ -404,10 +399,6 @@ err_open:
 
 static void fat_remove(struct device_d *dev)
 {
-	struct fat_priv *priv = dev->priv;
-
-	cdev_close(priv->cdev);
-
 	free(dev->priv);
 }
 

fs/fs.c

@@ -1231,6 +1231,9 @@ static void fs_remove(struct device_d *dev)
 	if (fsdev == fs_dev_root)
 		fs_dev_root = NULL;
 
+	if (fsdev->cdev)
+		cdev_close(fsdev->cdev);
+
 	free(fsdev->backingstore);
 	free(fsdev);
 }
@@ -1279,6 +1282,23 @@ static const char *detect_fs(const char *filename)
 	return NULL;
 }
 
+int fsdev_open_cdev(struct fs_device_d *fsdev)
+{
+	const char *backingstore = fsdev->backingstore;
+
+	if (!strncmp(backingstore , "/dev/", 5))
+		backingstore += 5;
+
+	fsdev->cdev = cdev_open(backingstore, O_RDWR);
+	if (!fsdev->cdev)
+		return -EINVAL;
+
+	fsdev->dev.parent = fsdev->cdev->dev;
+	fsdev->parent_device = fsdev->cdev->dev;
+
+	return 0;
+}
+
 /*
  * Mount a device to a directory.
  * We do this by registering a new device on which the filesystem
@@ -1323,14 +1343,6 @@ int mount(const char *device, const char *fsname, const char *_path)
 	fsdev->path = xstrdup(path);
 	fsdev->dev.bus = &fs_bus;
 
-	if (!strncmp(device, "/dev/", 5))
-		fsdev->cdev = cdev_by_name(device + 5);
-
-	if (fsdev->cdev) {
-		fsdev->dev.parent = fsdev->cdev->dev;
-		fsdev->parent_device = fsdev->cdev->dev;
-	}
-
 	ret = register_device(&fsdev->dev);
 	if (ret)
 		goto err_register;

fs/ubifs/ubifs.c

@@ -553,25 +553,22 @@ static int ubifs_probe(struct device_d *dev)
 {
 	struct fs_device_d *fsdev = dev_to_fs_device(dev);
 	struct ubifs_priv *priv = xzalloc(sizeof(struct ubifs_priv));
-	char *backingstore = fsdev->backingstore;
 	int ret;
 
 	dev->priv = priv;
 
-	if (!strncmp(backingstore , "/dev/", 5))
-		backingstore += 5;
-
-	priv->cdev = cdev_open(backingstore, O_RDONLY);
-	if (!priv->cdev) {
-		ret = -ENOENT;
+	ret = fsdev_open_cdev(fsdev);
+	if (ret)
 		goto err_free;
-	}
+
+	priv->cdev = fsdev->cdev;
 
 	priv->ubi = ubi_open_volume_cdev(priv->cdev, UBI_READONLY);
 	if (IS_ERR(priv->ubi)) {
 		dev_err(dev, "failed to open ubi volume: %s\n",
 				strerror(-PTR_ERR(priv->ubi)));
-		return PTR_ERR(priv->ubi);
+		ret = PTR_ERR(priv->ubi);
+		goto err_free;
 	}
 
 	priv->sb = ubifs_get_super(priv->ubi, 0);
@@ -596,7 +593,6 @@ static void ubifs_remove(struct device_d *dev)
 
 	ubifs_umount(c);
 	ubi_close_volume(priv->ubi);
-	cdev_close(priv->cdev);
 
 	free(c);
 	free(sb);

include/fs.h

@@ -193,4 +193,6 @@ void automount_print(void);
 
 int unlink_recursive(const char *path, char **failedpath);
 
+int fsdev_open_cdev(struct fs_device_d *fsdev);
+
 #endif /* __FS_H */