Commit 3188b295 authored by NeilBrown's avatar NeilBrown Committed by Al Viro
Browse files

ovl: rearrange ovl_follow_link to it doesn't need to call ->put_link 



ovl_follow_link current calls ->put_link on an error path.
However ->put_link is about to change in a way that it will be
impossible to call it from ovl_follow_link.

So rearrange the code to avoid the need for that error path.
Specifically: move the kmalloc() call before the ->follow_link()
call to the subordinate filesystem.

Signed-off-by: default avatarNeilBrown <neilb@suse.de>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 90e4fc88

fs/overlayfs/inode.c

+12 −13
Original line number Diff line number Diff line
@@ -145,6 +145,7 @@ static void *ovl_follow_link(struct dentry *dentry, struct nameidata *nd) 
	void *ret;

	struct dentry *realdentry;

	struct inode *realinode;

	struct ovl_link_data *data = NULL;



	realdentry = ovl_dentry_real(dentry);

	realinode = realdentry->d_inode;
@@ -152,25 +153,23 @@ static void *ovl_follow_link(struct dentry *dentry, struct nameidata *nd) 
	if (WARN_ON(!realinode->i_op->follow_link))

		return ERR_PTR(-EPERM);



	ret = realinode->i_op->follow_link(realdentry, nd);

	if (IS_ERR(ret))

		return ret;



	if (realinode->i_op->put_link) {

		struct ovl_link_data *data;



		data = kmalloc(sizeof(struct ovl_link_data), GFP_KERNEL);

		if (!data) {

			realinode->i_op->put_link(realdentry, nd, ret);

		if (!data)

			return ERR_PTR(-ENOMEM);

		}

		data->realdentry = realdentry;

	}



	ret = realinode->i_op->follow_link(realdentry, nd);

	if (IS_ERR(ret)) {

		kfree(data);

		return ret;

	}



	if (data)

		data->cookie = ret;



	return data;

	} else {

		return NULL;

	}

}



static void ovl_put_link(struct dentry *dentry, struct nameidata *nd, void *c)

CRA Git | Maintained and supported by SUSTech CRA and CCSE