Allow non-orphan PVs with two metadata areas to be resized.

We allow writing non-orphan PVs only for resize now. The "orphan PV" assert
in pv_write fn uses the "allow_non_orphan" parameter to control this assert.
However, we should find a more elaborate solution so we can remove this
restriction altogether (pv_write together with vg_write is not atomic, we
need to find a safe mechanism so there's an easy revert possible in case of
an error).

WHATS_NEW

@@ -5,8 +5,8 @@ Version 2.02.85 -
   Improve normal allocation algorithm to include clinging to existing areas.
   Add allocation/maximise_cling & mirror_logs_require_separate_pvs to lvm.conf.
   Fix metadata balance code to work with recent changes in metadata handling.
-  Add old_uuid field to physical_volume and fix pvchange -u for recent changes.
+  Add old_id field to physical_volume and fix pvchange -u for recent changes.
-  Allow pvresize on a PV with two metadata areas (for PVs not in a VG).
+  Allow pvresize on a PV with two metadata areas.
   Change pvcreate to use new metadata handling interface.
   Restructure existing pv_setup and pv_write fn, add pv_initialise fn.
   Add internal interface to support adding and removing metadata areas.

lib/format_text/format-text.c

@@ -1273,7 +1273,8 @@ static int _text_pv_write(const struct format_type *fmt, struct physical_volume
 
 	/* Add a new cache entry with PV info or update existing one. */
 	if (!(info = lvmcache_add(fmt->labeller, (const char *) &pv->id,
-			pv->dev, FMT_TEXT_ORPHAN_VG_NAME, NULL, 0)))
+		      pv->dev, pv->vg ? pv->vg->name : FMT_TEXT_ORPHAN_VG_NAME,
+		      NULL, 0)))
 		return_0;
 
 	label = info->label;
@@ -2161,17 +2162,6 @@ static int _text_pv_resize(const struct format_type *fmt,
 	/* If there's an mda at the end, move it to a new position. */
 	if ((mda = fid_get_mda_indexed(fid, pvid, ID_LEN, 1)) &&
 	    (mdac = mda->metadata_locn)) {
-		/*
-		 * FIXME: Remove this restriction - we need to
-		 *        allow writing PV labels on non-orphan VGs
-		 *        for this to work correctly.
-		 */
-		if (vg) {
-			log_error("Resizing a PV with two metadata areas "
-				  "that is part of a VG is not supported.");
-			return 0;
-		}
-
 		/* FIXME: Maybe MDA0 size would be better? */
 		mda_size = mdac->area.size >> SECTOR_SHIFT;
 		mda_ignored = mda_is_ignored(mda);

lib/metadata/metadata-exported.h

@@ -384,7 +384,7 @@ struct dm_list *get_vgnames(struct cmd_context *cmd, int include_internal);
 struct dm_list *get_vgids(struct cmd_context *cmd, int include_internal);
 int scan_vgs_for_pvs(struct cmd_context *cmd, int warnings);
 
-int pv_write(struct cmd_context *cmd, struct physical_volume *pv);
+int pv_write(struct cmd_context *cmd, struct physical_volume *pv, int allow_non_orphan);
 int move_pv(struct volume_group *vg_from, struct volume_group *vg_to,
 	    const char *pv_name);
 int move_pvs_used_by_lv(struct volume_group *vg_from,

lib/metadata/metadata.c

@@ -586,7 +586,7 @@ int vg_remove(struct volume_group *vg)
 		}
 
 		/* FIXME Write to same sector label was read from */
-		if (!pv_write(vg->cmd, pv)) {
+		if (!pv_write(vg->cmd, pv, 0)) {
 			log_error("Failed to remove physical volume \"%s\""
 				  " from volume group \"%s\"",
 				  pv_dev_name(pv), vg->name);
@@ -1511,7 +1511,7 @@ struct physical_volume * pvcreate_single(struct cmd_context *cmd,
 	log_very_verbose("Writing physical volume data to disk \"%s\"",
 			 pv_name);
 
-	if (!(pv_write(cmd, pv))) {
+	if (!(pv_write(cmd, pv, 0))) {
 		log_error("Failed to write physical volume \"%s\"", pv_name);
 		goto error;
 	}
@@ -3536,7 +3536,7 @@ int scan_vgs_for_pvs(struct cmd_context *cmd, int warnings)
 }
 
 int pv_write(struct cmd_context *cmd __attribute__((unused)),
-	     struct physical_volume *pv)
+	     struct physical_volume *pv, int allow_non_orphan)
 {
 	if (!pv->fmt->ops->pv_write) {
 		log_error("Format does not support writing physical volumes");
@@ -3549,7 +3549,8 @@ int pv_write(struct cmd_context *cmd __attribute__((unused)),
 	 *        to provide some revert mechanism since PV label together
 	 *        with VG metadata write is not atomic.
 	 */
-	if (!is_orphan_vg(pv->vg_name) || pv->pe_alloc_count) {
+	if (!allow_non_orphan &&
+	    (!is_orphan_vg(pv->vg_name) || pv->pe_alloc_count)) {
 		log_error("Assertion failed: can't _pv_write non-orphan PV "
 			  "(in VG %s)", pv->vg_name);
 		return 0;
@@ -3574,7 +3575,7 @@ int pv_write_orphan(struct cmd_context *cmd, struct physical_volume *pv)
 		return 0;
 	}
 
-	if (!pv_write(cmd, pv)) {
+	if (!pv_write(cmd, pv, 0)) {
 		log_error("Failed to clear metadata from physical "
 			  "volume \"%s\" after removal from \"%s\"",
 			  pv_dev_name(pv), old_vg_name);

lib/metadata/metadata.h

@@ -192,6 +192,7 @@ unsigned mda_is_ignored(struct metadata_area *mda);
 void mda_set_ignored(struct metadata_area *mda, unsigned ignored);
 unsigned mda_locns_match(struct metadata_area *mda1, struct metadata_area *mda2);
 void vg_set_fid(struct volume_group *vg, struct format_instance *fid);
+/* FIXME: Add generic interface for mda counts based on given key. */
 int fid_add_mda(struct format_instance *fid, struct metadata_area *mda,
 		const char *key, size_t key_len, const unsigned sub_key);
 int fid_add_mdas(struct format_instance *fid, struct dm_list *mdas,

tools/pvchange.c

@@ -140,7 +140,7 @@ static int _pvchange_single(struct cmd_context *cmd, struct volume_group *vg,
 
 			pv->vg_name = pv->fmt->orphan_vg_name;
 			pv->pe_alloc_count = 0;
-			if (!(pv_write(cmd, pv))) {
+			if (!(pv_write(cmd, pv, 0))) {
 				log_error("pv_write with new uuid failed "
 					  "for %s.", pv_name);
 				return 0;
@@ -162,7 +162,7 @@ static int _pvchange_single(struct cmd_context *cmd, struct volume_group *vg,
 			return 0;
 		}
 		backup(vg);
-	} else if (!(pv_write(cmd, pv))) {
+	} else if (!(pv_write(cmd, pv, 0))) {
 		log_error("Failed to store physical volume \"%s\"",
 			  pv_name);
 		return 0;

tools/pvresize.c

@@ -15,6 +15,7 @@
  */
 
 #include "tools.h"
+#include "metadata.h"
 
 struct pvresize_params {
 	uint64_t new_size;
@@ -96,6 +97,16 @@ static int _pv_resize_single(struct cmd_context *cmd,
 		goto_out;
 
 	log_verbose("Updating physical volume \"%s\"", pv_name);
+
+	/* Write PV label only if this an orphan PV or it has 2nd mda. */
+	if ((is_orphan_vg(vg_name) ||
+	    fid_get_mda_indexed(vg->fid, (const char *) &pv->id, ID_LEN, 1)) &&
+	    !pv_write(cmd, pv, 1)) {
+		log_error("Failed to store physical volume \"%s\"",
+			  pv_name);
+		goto out;
+	}
+
 	if (!is_orphan_vg(vg_name)) {
 		if (!vg_write(vg) || !vg_commit(vg)) {
 			log_error("Failed to store physical volume \"%s\" in "
@@ -103,10 +114,6 @@ static int _pv_resize_single(struct cmd_context *cmd,
 			goto out;
 		}
 		backup(vg);
-	} else if (!(pv_write(cmd, pv))) {
-		log_error("Failed to store physical volume \"%s\"",
-			  pv_name);
-		goto out;
 	}
 
 	log_print("Physical volume \"%s\" changed", pv_name);

tools/vgconvert.c

@@ -151,7 +151,7 @@ static int vgconvert_single(struct cmd_context *cmd, const char *vg_name,
 
 		log_very_verbose("Writing physical volume data to disk \"%s\"",
 				 pv_dev_name(pv));
-		if (!(pv_write(cmd, pv))) {
+		if (!(pv_write(cmd, pv, 0))) {
 			log_error("Failed to write physical volume \"%s\"",
 				  pv_dev_name(pv));
 			log_error("Use pvcreate and vgcfgrestore to repair "

tools/vgreduce.c

@@ -438,7 +438,7 @@ static int _vgreduce_single(struct cmd_context *cmd, struct volume_group *vg,
 		goto bad;
 	}
 
-	if (!pv_write(cmd, pv)) {
+	if (!pv_write(cmd, pv, 0)) {
 		log_error("Failed to clear metadata from physical "
 			  "volume \"%s\" "
 			  "after removal from \"%s\"", name, vg->name);