drbd: Implemented the --assume-clean option for drbdsetup resize

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>

drivers/block/drbd/drbd_nl.c

@@ -1479,6 +1479,7 @@ static int drbd_nl_resize(struct drbd_conf *mdev, struct drbd_nl_cfg_req *nlp,
 	int retcode = NO_ERROR;
 	int ldsc = 0; /* local disk size changed */
 	enum determine_dev_size dd;
+	enum dds_flags ddsf;
 
 	memset(&rs, 0, sizeof(struct resize));
 	if (!resize_from_tags(mdev, nlp->tag_list, &rs)) {
@@ -1502,13 +1503,19 @@ static int drbd_nl_resize(struct drbd_conf *mdev, struct drbd_nl_cfg_req *nlp,
 		goto fail;
 	}
 
+	if (rs.no_resync && mdev->agreed_pro_version < 93) {
+		retcode = ERR_NEED_APV_93;
+		goto fail;
+	}
+
 	if (mdev->ldev->known_size != drbd_get_capacity(mdev->ldev->backing_bdev)) {
 		mdev->ldev->known_size = drbd_get_capacity(mdev->ldev->backing_bdev);
 		ldsc = 1;
 	}
 
 	mdev->ldev->dc.disk_size = (sector_t)rs.resize_size;
-	dd = drbd_determin_dev_size(mdev, rs.resize_force ? DDSF_FORCED : 0);
+	ddsf = (rs.resize_force ? DDSF_FORCED : 0) | (rs.no_resync ? DDSF_NO_RESYNC : 0);
+	dd = drbd_determin_dev_size(mdev, ddsf);
 	drbd_md_sync(mdev);
 	put_ldev(mdev);
 	if (dd == dev_size_error) {
@@ -1521,7 +1528,7 @@ static int drbd_nl_resize(struct drbd_conf *mdev, struct drbd_nl_cfg_req *nlp,
 			set_bit(RESIZE_PENDING, &mdev->flags);
 
 		drbd_send_uuids(mdev);
-		drbd_send_sizes(mdev, 1, 0);
+		drbd_send_sizes(mdev, 1, ddsf);
 	}
 
  fail:

include/linux/drbd.h

@@ -56,7 +56,7 @@ extern const char *drbd_buildtag(void);
 #define REL_VERSION "8.3.7"
 #define API_VERSION 88
 #define PRO_VERSION_MIN 86
-#define PRO_VERSION_MAX 92
+#define PRO_VERSION_MAX 93
 
 
 enum drbd_io_error_p {
@@ -139,6 +139,7 @@ enum drbd_ret_codes {
 	ERR_DATA_NOT_CURRENT	= 150,
 	ERR_CONNECTED		= 151, /* DRBD 8.3 only */
 	ERR_PERM		= 152,
+	ERR_NEED_APV_93		= 153,
 
 	/* insert new ones above this line */
 	AFTER_LAST_ERR_CODE

include/linux/drbd_nl.h

@@ -71,6 +71,7 @@ NL_PACKET(disconnect, 6, )
 NL_PACKET(resize, 7,
 	NL_INT64(		29,	T_MAY_IGNORE,	resize_size)
 	NL_BIT(			68,	T_MAY_IGNORE,	resize_force)
+	NL_BIT(			69,	T_MANDATORY,	no_resync)
 )
 
 NL_PACKET(syncer_conf, 8,