From b71dc87559cefd4a4d0a4007130a431aa6344801 Mon Sep 17 00:00:00 2001
From: Conrad Meyer <cem@FreeBSD.org>
Date: Fri, 29 May 2020 19:44:18 +0000
Subject: [PATCH] geom_part: Dispatch to partitions to create providers and
 aliases

This allows partitions to create additional aliases of their own.  The
default method implementations preserve the existing behavior.

No functional change.

Reviewed by:	imp
Differential Revision:	https://reviews.freebsd.org/D24938
---
 sys/geom/part/g_part.c    | 16 +++-----------
 sys/geom/part/g_part_if.m | 45 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 48 insertions(+), 13 deletions(-)

diff --git a/sys/geom/part/g_part.c b/sys/geom/part/g_part.c
index dba1b683804..1619817e279 100644
--- a/sys/geom/part/g_part.c
+++ b/sys/geom/part/g_part.c
@@ -469,7 +469,6 @@ g_part_new_provider(struct g_geom *gp, struct g_part_table *table,
 {
 	struct g_consumer *cp;
 	struct g_provider *pp;
-	struct sbuf *sb;
 	struct g_geom_alias *gap;
 	off_t offset;
 
@@ -481,11 +480,7 @@ g_part_new_provider(struct g_geom *gp, struct g_part_table *table,
 		entry->gpe_offset = offset;
 
 	if (entry->gpe_pp == NULL) {
-		sb = sbuf_new_auto();
-		G_PART_FULLNAME(table, entry, sb, gp->name);
-		sbuf_finish(sb);
-		entry->gpe_pp = g_new_providerf(gp, "%s", sbuf_data(sb));
-		sbuf_delete(sb);
+		entry->gpe_pp = G_PART_NEW_PROVIDER(table, gp, entry, gp->name);
 		/*
 		 * If our parent provider had any aliases, then copy them to our
 		 * provider so when geom DEV tastes things later, they will be
@@ -493,13 +488,8 @@ g_part_new_provider(struct g_geom *gp, struct g_part_table *table,
 		 * place of the geom's name we use to create the provider. The
 		 * kobj interface that generates names makes this awkward.
 		 */
-		LIST_FOREACH(gap, &pp->aliases, ga_next) {
-			sb = sbuf_new_auto();
-			G_PART_FULLNAME(table, entry, sb, gap->ga_alias);
-			sbuf_finish(sb);
-			g_provider_add_alias(entry->gpe_pp, "%s", sbuf_data(sb));
-			sbuf_delete(sb);
-		}
+		LIST_FOREACH(gap, &pp->aliases, ga_next)
+			G_PART_ADD_ALIAS(table, entry->gpe_pp, entry, gap->ga_alias);
 		entry->gpe_pp->flags |= G_PF_DIRECT_SEND | G_PF_DIRECT_RECEIVE;
 		entry->gpe_pp->private = entry;		/* Close the circle. */
 	}
diff --git a/sys/geom/part/g_part_if.m b/sys/geom/part/g_part_if.m
index 5b959a3e593..577fdad8520 100644
--- a/sys/geom/part/g_part_if.m
+++ b/sys/geom/part/g_part_if.m
@@ -52,6 +52,34 @@ CODE {
 		    G_PART_NAME(table, entry, buf, sizeof(buf)));
 	}
 
+	static struct g_provider *
+	default_new_provider(struct g_part_table *table, struct g_geom *gp,
+	    struct g_part_entry *entry, const char *pfx)
+	{
+		struct g_provider *ret;
+		struct sbuf *sb;
+
+		sb = sbuf_new_auto();
+		G_PART_FULLNAME(table, entry, sb, pfx);
+		sbuf_finish(sb);
+		ret = g_new_providerf(gp, "%s", sbuf_data(sb));
+		sbuf_delete(sb);
+		return (ret);
+	}
+
+	static void
+	default_add_alias(struct g_part_table *table, struct g_provider *pp,
+	    struct g_part_entry *entry, const char *pfx)
+	{
+		struct sbuf *sb;
+
+		sb = sbuf_new_auto();
+		G_PART_FULLNAME(table, entry, sb, pfx);
+		sbuf_finish(sb);
+		g_provider_add_alias(pp, "%s", sbuf_data(sb));
+		sbuf_delete(sb);
+	}
+
 	static int
 	default_precheck(struct g_part_table *t __unused,
 	    enum g_part_ctl r __unused, struct g_part_parms *p __unused)
@@ -88,6 +116,15 @@ METHOD int add {
 	struct g_part_parms *gpp;
 };
 
+# add_alias() - Create aliases for the partition's provider with the given
+# alias prefixes.
+METHOD void add_alias {
+	struct g_part_table *table;
+	struct g_provider *pp;
+	struct g_part_entry *entry;
+	const char *pfx;
+} DEFAULT default_add_alias;
+
 # bootcode() - scheme specific processing for the bootcode verb.
 METHOD int bootcode {
 	struct g_part_table *table;
@@ -145,6 +182,14 @@ METHOD int modify {
 	struct g_part_parms *gpp;
 };
 
+# new_provider() - Create the partition's provider(s).
+METHOD struct g_provider * new_provider {
+	struct g_part_table *table;
+	struct g_geom *gp;
+	struct g_part_entry *entry;
+	const char *pfx;
+} DEFAULT default_new_provider;
+
 # resize() - scheme specific processing for the resize verb.
 METHOD int resize {
 	struct g_part_table *table;