ceph: mark directory as non-complete after loading key

When setting a directory's crypt context, ceph_dir_clear_complete()
needs to be called otherwise if it was complete before, any existing
(old) dentry will still be valid.

This patch adds a wrapper around __fscrypt_prepare_readdir() which will
ensure a directory is marked as non-complete if key status changes.

[ xiubli: revise commit title per Milind ]

Signed-off-by: Luís Henriques <lhenriques@suse.de>
Reviewed-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Milind Changire <mchangir@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

1 files changed, 33 insertions, 2 deletions

diff --git a/fs/ceph/crypto.c b/fs/ceph/crypto.c
index a08978a0ed4d..5df2c52b384f 100644
--- a/fs/ceph/crypto.c
+++ b/fs/ceph/crypto.c
@@ -287,8 +287,8 @@ int ceph_fname_to_usr(const struct ceph_fname *fname, struct fscrypt_str *tname,
 	if (fname->name_len > NAME_MAX || fname->ctext_len > NAME_MAX)
 		return -EIO;
 
-	ret = __fscrypt_prepare_readdir(fname->dir);
-	if (ret)
+	ret = ceph_fscrypt_prepare_readdir(fname->dir);
+	if (ret < 0)
 		return ret;
 
 	/*
@@ -334,3 +334,34 @@ out:
 	fscrypt_fname_free_buffer(&_tname);
 	return ret;
 }
+
+/**
+ * ceph_fscrypt_prepare_readdir - simple __fscrypt_prepare_readdir() wrapper
+ * @dir: directory inode for readdir prep
+ *
+ * Simple wrapper around __fscrypt_prepare_readdir() that will mark directory as
+ * non-complete if this call results in having the directory unlocked.
+ *
+ * Returns:
+ *     1 - if directory was locked and key is now loaded (i.e. dir is unlocked)
+ *     0 - if directory is still locked
+ *   < 0 - if __fscrypt_prepare_readdir() fails
+ */
+int ceph_fscrypt_prepare_readdir(struct inode *dir)
+{
+	bool had_key = fscrypt_has_encryption_key(dir);
+	int err;
+
+	if (!IS_ENCRYPTED(dir))
+		return 0;
+
+	err = __fscrypt_prepare_readdir(dir);
+	if (err)
+		return err;
+	if (!had_key && fscrypt_has_encryption_key(dir)) {
+		/* directory just got unlocked, mark it as not complete */
+		ceph_dir_clear_complete(dir);
+		return 1;
+	}
+	return 0;
+}