ceph: add support for encrypted snapshot names

Since filenames in encrypted directories are already encrypted and shown
as a base64-encoded string when the directory is locked, snapshot names
should show a similar behaviour.

Signed-off-by: Luís Henriques <lhenriques@suse.de>
Reviewed-by: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>

diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index 6cb791bc870197d271edd9b60a29d0a8a620e90f..a8a6e55252c0f4ca336fc2038c5c12c31203ff98 100644 (file)
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -92,9 +92,15 @@ struct inode *ceph_new_inode(struct inode *dir, struct dentry *dentry,
        if (err < 0)
                goto out_err;
 
-       err = ceph_fscrypt_prepare_context(dir, inode, as_ctx);
-       if (err)
-               goto out_err;
+       /*
+        * We'll skip setting fscrypt context for snapshots, leaving that for
+        * the handle_reply().
+        */
+       if (ceph_snap(dir) != CEPH_SNAPDIR) {
+               err = ceph_fscrypt_prepare_context(dir, inode, as_ctx);
+               if (err)
+                       goto out_err;
+       }
 
        return inode;
 out_err:
@@ -158,6 +164,7 @@ struct inode *ceph_get_snapdir(struct inode *parent)
        };
        struct inode *inode = ceph_get_inode(parent->i_sb, vino, NULL);
        struct ceph_inode_info *ci = ceph_inode(inode);
+       int ret = -ENOTDIR;
 
        if (IS_ERR(inode))
                return inode;
@@ -183,6 +190,24 @@ struct inode *ceph_get_snapdir(struct inode *parent)
        ci->i_rbytes = 0;
        ci->i_btime = ceph_inode(parent)->i_btime;
 
+#ifdef CONFIG_FS_ENCRYPTION
+       /* if encrypted, just borrow fscrypt_auth from parent */
+       if (IS_ENCRYPTED(parent)) {
+               struct ceph_inode_info *pci = ceph_inode(parent);
+
+               ci->fscrypt_auth = kmemdup(pci->fscrypt_auth,
+                                          pci->fscrypt_auth_len,
+                                          GFP_KERNEL);
+               if (ci->fscrypt_auth) {
+                       inode->i_flags |= S_ENCRYPTED;
+                       ci->fscrypt_auth_len = pci->fscrypt_auth_len;
+               } else {
+                       dout("Failed to alloc snapdir fscrypt_auth\n");
+                       ret = -ENOMEM;
+                       goto err;
+               }
+       }
+#endif
        if (inode->i_state & I_NEW) {
                inode->i_op = &ceph_snapdir_iops;
                inode->i_fop = &ceph_snapdir_fops;
@@ -196,7 +221,7 @@ err:
                discard_new_inode(inode);
        else
                iput(inode);
-       return ERR_PTR(-ENOTDIR);
+       return ERR_PTR(ret);
 }
 
 const struct inode_operations ceph_file_iops = {