ecryptfs: get rid of pointless mount references in ecryptfs dentries

->lower_path.mnt has the same value for all dentries on given ecryptfs
instance and if somebody goes for mountpoint-crossing variant where that
would not be true, we can deal with that when it happens (and _not_
with duplicating these reference into each dentry).

As it is, we are better off just sticking a reference into ecryptfs-private
part of superblock and keeping it pinned until ->kill_sb().

That way we can stick a reference to underlying dentry right into ->d_fsdata
of ecryptfs one, getting rid of indirection through struct ecryptfs_dentry_info,
along with the entire struct ecryptfs_dentry_info machinery.

[kudos to Dan Carpenter for spotting a bug in ecryptfs_get_tree() part]

Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 1 insertions, 13 deletions

diff --git a/fs/ecryptfs/dentry.c b/fs/ecryptfs/dentry.c
index 1dfd5b81d831..6648a924e31a 100644
--- a/fs/ecryptfs/dentry.c
+++ b/fs/ecryptfs/dentry.c
@@ -59,14 +59,6 @@ static int ecryptfs_d_revalidate(struct inode *dir, const struct qstr *name,
 	return rc;
 }
 
-struct kmem_cache *ecryptfs_dentry_info_cache;
-
-static void ecryptfs_dentry_free_rcu(struct rcu_head *head)
-{
-	kmem_cache_free(ecryptfs_dentry_info_cache,
-		container_of(head, struct ecryptfs_dentry_info, rcu));
-}
-
 /**
  * ecryptfs_d_release
  * @dentry: The ecryptfs dentry
@@ -75,11 +67,7 @@ static void ecryptfs_dentry_free_rcu(struct rcu_head *head)
  */
 static void ecryptfs_d_release(struct dentry *dentry)
 {
-	struct ecryptfs_dentry_info *p = dentry->d_fsdata;
-	if (p) {
-		path_put(&p->lower_path);
-		call_rcu(&p->rcu, ecryptfs_dentry_free_rcu);
-	}
+	dput(dentry->d_fsdata);
 }
 
 const struct dentry_operations ecryptfs_dops = {