ceph: add support to readdir for encrypted names

To make it simpler to decrypt names in a readdir reply (i.e. before
we have a dentry), add a new ceph_encode_encrypted_fname()-like helper
that takes a qstr pointer instead of a dentry pointer.

Once we've decrypted the names in a readdir reply, we no longer need the
crypttext, so overwrite them in ceph_mds_reply_dir_entry with the
unencrypted names. Then in both ceph_readdir_prepopulate() and
ceph_readdir() we will use the dencrypted name directly.

[ jlayton: convert some BUG_ONs into error returns ]

Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-and-tested-by: Luís Henriques <lhenriques@suse.de>
Reviewed-by: Milind Changire <mchangir@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/fs/ceph/crypto.h b/fs/ceph/crypto.h
index a53645123248..3269fc8f8cf3 100644
--- a/fs/ceph/crypto.h
+++ b/fs/ceph/crypto.h
@@ -19,6 +19,7 @@ struct ceph_fname {
 	unsigned char	*ctext;		// binary crypttext (if any)
 	u32		name_len;	// length of name buffer
 	u32		ctext_len;	// length of crypttext
+	bool		no_copy;
 };
 
 struct ceph_fscrypt_auth {
@@ -76,6 +77,8 @@ int ceph_fscrypt_prepare_context(struct inode *dir, struct inode *inode,
 				 struct ceph_acl_sec_ctx *as);
 void ceph_fscrypt_as_ctx_to_req(struct ceph_mds_request *req,
 				struct ceph_acl_sec_ctx *as);
+int ceph_encode_encrypted_dname(const struct inode *parent,
+				struct qstr *d_name, char *buf);
 int ceph_encode_encrypted_fname(const struct inode *parent,
 				struct dentry *dentry, char *buf);
 
@@ -121,6 +124,13 @@ static inline void ceph_fscrypt_as_ctx_to_req(struct ceph_mds_request *req,
 {
 }
 
+static inline int ceph_encode_encrypted_dname(const struct inode *parent,
+					      struct qstr *d_name, char *buf)
+{
+	memcpy(buf, d_name->name, d_name->len);
+	return d_name->len;
+}
+
 static inline int ceph_encode_encrypted_fname(const struct inode *parent,
 					      struct dentry *dentry, char *buf)
 {