ceph: return -EINVAL if given fsc mount option on kernel w/o support

[ Upstream commit ff29fde84d1fc82f233c7da0daa3574a3942bec7 ]

If someone requests fscache on the mount, and the kernel doesn't
support it, it should fail the mount.

[ Drop ceph prefix -- it's provided by pr_err. ]
Signed-off-by: NJeff Layton <jlayton@kernel.org>
Reviewed-by: NIlya Dryomov <idryomov@gmail.com>
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

fs/ceph/super.c

@@ -248,6 +248,7 @@ static int parse_fsopt_token(char *c, void *private)
 			return -ENOMEM;
 		break;
 	case Opt_fscache_uniq:
+#ifdef CONFIG_CEPH_FSCACHE
 		kfree(fsopt->fscache_uniq);
 		fsopt->fscache_uniq = kstrndup(argstr[0].from,
 					       argstr[0].to-argstr[0].from,
@@ -256,7 +257,10 @@ static int parse_fsopt_token(char *c, void *private)
 			return -ENOMEM;
 		fsopt->flags |= CEPH_MOUNT_OPT_FSCACHE;
 		break;
-		/* misc */
+#else
+		pr_err("fscache support is disabled\n");
+		return -EINVAL;
+#endif
 	case Opt_wsize:
 		if (intval < (int)PAGE_SIZE || intval > CEPH_MAX_WRITE_SIZE)
 			return -EINVAL;
@@ -328,10 +332,15 @@ static int parse_fsopt_token(char *c, void *private)
 		fsopt->flags &= ~CEPH_MOUNT_OPT_INO32;
 		break;
 	case Opt_fscache:
+#ifdef CONFIG_CEPH_FSCACHE
 		fsopt->flags |= CEPH_MOUNT_OPT_FSCACHE;
 		kfree(fsopt->fscache_uniq);
 		fsopt->fscache_uniq = NULL;
 		break;
+#else
+		pr_err("fscache support is disabled\n");
+		return -EINVAL;
+#endif
 	case Opt_nofscache:
 		fsopt->flags &= ~CEPH_MOUNT_OPT_FSCACHE;
 		kfree(fsopt->fscache_uniq);