From 29ebccc3e26b472a0873951736f4057487b143c2 Mon Sep 17 00:00:00 2001
From: Alasdair Kergon <agk@redhat.com>
Date: Tue, 26 Aug 2003 21:12:06 +0000
Subject: [PATCH] Cope better when format functions are missing.

---
 lib/label/label.c       | 11 +++++++++--
 lib/metadata/metadata.c | 21 ++++++++++++++++++++-
 2 files changed, 29 insertions(+), 3 deletions(-)

diff --git a/lib/label/label.c b/lib/label/label.c
index dc549dafd..0c78ed0dd 100644
--- a/lib/label/label.c
+++ b/lib/label/label.c
@@ -280,6 +280,11 @@ int label_write(struct device *dev, struct label *label)
 	struct label_header *lh = (struct label_header *) buf;
 	int r = 1;
 
+	if (!label->labeller->ops->write) {
+		log_err("Label handler does not support label writes");
+		return 0;
+	}
+
 	if ((LABEL_SIZE + (label->sector << SECTOR_SHIFT)) > LABEL_SCAN_SIZE) {
 		log_error("Label sector %" PRIu64 " beyond range (%ld)",
 			  label->sector, LABEL_SCAN_SECTORS);
@@ -292,8 +297,10 @@ int label_write(struct device *dev, struct label *label)
 	lh->sector_xl = xlate64(label->sector);
 	lh->offset_xl = xlate32(sizeof(*lh));
 
-	if (!label->labeller->ops->write(label, buf))
+	if (!label->labeller->ops->write(label, buf)) {
+		stack;
 		return 0;
+	}
 
 	lh->crc_xl = xlate32(calc_crc(INITIAL_CRC, &lh->offset_xl, LABEL_SIZE -
 				      ((void *) &lh->offset_xl - (void *) lh)));
@@ -327,7 +334,7 @@ int label_verify(struct device *dev)
 		return 0;
 	}
 
-	return l->ops->verify(l, buf, sector);
+	return ((l->ops->verify) ? l->ops->verify(l, buf, sector) : 1);
 }
 
 void label_destroy(struct label *label)
diff --git a/lib/metadata/metadata.c b/lib/metadata/metadata.c
index 3f2bc054e..6acf843ae 100644
--- a/lib/metadata/metadata.c
+++ b/lib/metadata/metadata.c
@@ -217,7 +217,8 @@ struct volume_group *vg_create(struct cmd_context *cmd, const char *vg_name,
 		goto bad;
 	}
 
-	if (!vg->fid->fmt->ops->vg_setup(vg->fid, vg)) {
+	if (vg->fid->fmt->ops->vg_setup &&
+	    !vg->fid->fmt->ops->vg_setup(vg->fid, vg)) {
 		log_error("Format specific setup of volume group '%s' failed.",
 			  vg_name);
 		goto bad;
@@ -463,6 +464,19 @@ int vg_write(struct volume_group *vg)
 	/* Write to each copy of the metadata area */
 	list_iterate(mdah, &vg->fid->metadata_areas) {
 		mda = list_item(mdah, struct metadata_area);
+		if(!mda->ops->vg_write) {
+			log_error("Format does not support writing volume"
+				  "group metadata areas");
+			/* Revert */
+			list_uniterate(mdah2, &vg->fid->metadata_areas, mdah) {
+				mda = list_item(mdah2, struct metadata_area);
+				if (mda->ops->vg_revert &&
+				    !mda->ops->vg_revert(vg->fid, vg, mda)) {
+					stack;
+				}
+			}
+			return 0;
+		}
 		if (!mda->ops->vg_write(vg->fid, vg, mda)) {
 			stack;
 			/* Revert */
@@ -869,6 +883,11 @@ struct list *get_pvs(struct cmd_context *cmd)
 int pv_write(struct cmd_context *cmd, struct physical_volume *pv,
 	     struct list *mdas, int64_t label_sector)
 {
+	if (!pv->fmt->ops->pv_write) {
+		log_error("Format does not support writing physical volumes");
+		return 0;
+	}
+
 	if (*pv->vg_name || pv->pe_alloc_count) {
 		log_error("Assertion failed: can't _pv_write non-orphan PV "
 			  "(in VG %s)", pv->vg_name);