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: NeilBrown <neilb@suse.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index 04f1248..1b4b9c5e 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -145,6 +145,7 @@
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 @@
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;
- }
+ return data;
}
static void ovl_put_link(struct dentry *dentry, struct nameidata *nd, void *c)