Move common zfs ioctl compatibility functions (userland) into libzfs_compat.c

Introduce additional constants for zfs ioctl versions

1 files changed, 103 insertions, 0 deletions

diff --git a/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_compat.c b/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_compat.c
new file mode 100644
index 0000000..2a2ae76
--- /dev/null
+++ b/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_compat.c
@@ -0,0 +1,103 @@
+/*
+ * CDDL HEADER SART
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+
+/*
+ * Copyright (c) 2013 Martin Matuska <mm@FreeBSD.org>. All rights reserved.
+ */
+
+#include "libzfs_compat.h"
+
+int zfs_ioctl_version = ZFS_IOCVER_UNDEF;
+static int zfs_spa_version = -1;
+
+/*
+ * Get zfs_ioctl_version
+ */
+int
+get_zfs_ioctl_version(void)
+{
+	size_t ver_size;
+	int ver = ZFS_IOCVER_NONE;
+
+	ver_size = sizeof(ver);
+	sysctlbyname("vfs.zfs.version.ioctl", &ver, &ver_size, NULL, 0);
+
+	return (ver);
+}
+
+/*
+ * Get the SPA version
+ */
+static int
+get_zfs_spa_version(void)
+{
+	size_t ver_size;
+	int ver = 0;
+
+	ver_size = sizeof(ver);
+	sysctlbyname("vfs.zfs.version.spa", &ver, &ver_size, NULL, 0);
+
+	return (ver);
+}
+
+/*
+ * This is FreeBSD version of ioctl, because Solaris' ioctl() updates
+ * zc_nvlist_dst_size even if an error is returned, on FreeBSD if an
+ * error is returned zc_nvlist_dst_size won't be updated.
+ */
+int
+zcmd_ioctl(int fd, int request, zfs_cmd_t *zc)
+{
+	size_t oldsize;
+	int ret, cflag = ZFS_CMD_COMPAT_NONE;
+
+	if (zfs_ioctl_version == ZFS_IOCVER_UNDEF)
+		zfs_ioctl_version = get_zfs_ioctl_version();
+
+	if (zfs_ioctl_version == ZFS_IOCVER_DEADMAN)
+		cflag = ZFS_CMD_COMPAT_DEADMAN;
+
+	/*
+	 * If vfs.zfs.version.ioctl is not defined, assume we have v28
+	 * compatible binaries and use vfs.zfs.version.spa to test for v15
+	 */
+	if (zfs_ioctl_version < ZFS_IOCVER_DEADMAN) {
+		cflag = ZFS_CMD_COMPAT_V28;
+
+		if (zfs_spa_version < 0)
+			zfs_spa_version = get_zfs_spa_version();
+
+		if (zfs_spa_version == SPA_VERSION_15 ||
+		    zfs_spa_version == SPA_VERSION_14 ||
+		    zfs_spa_version == SPA_VERSION_13)
+			cflag = ZFS_CMD_COMPAT_V15;
+	}
+
+	oldsize = zc->zc_nvlist_dst_size;
+	ret = zcmd_ioctl_compat(fd, request, zc, cflag);
+
+	if (ret == 0 && oldsize < zc->zc_nvlist_dst_size) {
+		ret = -1;
+		errno = ENOMEM;
+	}
+
+	return (ret);
+}