svn commit: r322196 - head/sys/geom

[Warner Losh]

Author: imp
Date: Mon Aug  7 21:12:28 2017
New Revision: 322196
URL: https://svnweb.freebsd.org/changeset/base/322196

Log:
  Add aliasing concept to geom.
  
  Add an alias name list to geoms. Use them in geom_dev to create
  aliases. Previously, geom_dev would create an device node for the name
  of the geom. Now, additional nodes are created pointing back to the
  primary node with make_dev_alias_p. Aliases must be in place on the
  geom before any tasting occurs.
  
  Differential Revision: https://reviews.freebsd.org/D11873

Modified:
  head/sys/geom/geom.h
  head/sys/geom/geom_dev.c
  head/sys/geom/geom_dump.c
  head/sys/geom/geom_subr.c

Modified: head/sys/geom/geom.h
==============================================================================
--- head/sys/geom/geom.h	Mon Aug  7 19:56:09 2017	(r322195)
+++ head/sys/geom/geom.h	Mon Aug  7 21:12:28 2017	(r322196)
@@ -120,6 +120,15 @@ struct g_class {
 	LIST_HEAD(,g_geom)	geom;
 };
 
+/*
+ * The g_geom_alias is a list node for aliases for the geom name
+ * for device node creation.
+ */
+struct g_geom_alias {
+	LIST_ENTRY(g_geom_alias) ga_next;
+	const char		*ga_alias;
+};
+
 #define G_VERSION_00	0x19950323
 #define G_VERSION_01	0x20041207	/* add fflag to g_ioctl_t */
 #define G_VERSION	G_VERSION_01
@@ -150,6 +159,7 @@ struct g_geom {
 	unsigned		flags;
 #define	G_GEOM_WITHER		1
 #define	G_GEOM_VOLATILE_BIO	2
+	LIST_HEAD(,g_geom_alias) aliases;
 };
 
 /*
@@ -269,6 +279,7 @@ void g_destroy_provider(struct g_provider *pp);
 void g_detach(struct g_consumer *cp);
 void g_error_provider(struct g_provider *pp, int error);
 struct g_provider *g_provider_by_name(char const *arg);
+void g_geom_add_alias(struct g_geom *gp, const char *alias);
 int g_getattr__(const char *attr, struct g_consumer *cp, void *var, int len);
 #define g_getattr(a, c, v) g_getattr__((a), (c), (v), sizeof *(v))
 int g_handleattr(struct bio *bp, const char *attribute, const void *val,

Modified: head/sys/geom/geom_dev.c
==============================================================================
--- head/sys/geom/geom_dev.c	Mon Aug  7 19:56:09 2017	(r322195)
+++ head/sys/geom/geom_dev.c	Mon Aug  7 21:12:28 2017	(r322196)
@@ -315,10 +315,11 @@ static struct g_geom *
 g_dev_taste(struct g_class *mp, struct g_provider *pp, int insist __unused)
 {
 	struct g_geom *gp;
+	struct g_geom_alias *gap;
 	struct g_consumer *cp;
 	struct g_dev_softc *sc;
 	int error;
-	struct cdev *dev;
+	struct cdev *dev, *adev;
 	char buf[SPECNAMELEN + 6];
 
 	g_trace(G_T_TOPOLOGY, "dev_taste(%s,%s)", mp->name, pp->name);
@@ -357,6 +358,23 @@ g_dev_taste(struct g_class *mp, struct g_provider *pp,
 	g_dev_attrchanged(cp, "GEOM::physpath");
 	snprintf(buf, sizeof(buf), "cdev=%s", gp->name);
 	devctl_notify_f("GEOM", "DEV", "CREATE", buf, M_WAITOK);
+	/*
+	 * Now add all the aliases for this drive
+	 */
+	LIST_FOREACH(gap, &pp->geom->aliases, ga_next) {
+		error = make_dev_alias_p(MAKEDEV_CHECKNAME | MAKEDEV_WAITOK, &adev, dev,
+		    "%s", gap->ga_alias);
+		if (error) {
+			printf("%s: make_dev_alias_p() failed (name=%s, error=%d)\n",
+			    __func__, gap->ga_alias, error);
+			continue;
+		}
+		adev->si_flags |= SI_UNMAPPED;
+		adev->si_iosize_max = dev->si_iosize_max;
+		adev->si_drv2 = dev->si_drv2;
+		snprintf(buf, sizeof(buf), "cdev=%s", gap->ga_alias);
+		devctl_notify_f("GEOM", "DEV", "CREATE", buf, M_WAITOK);
+	}
 
 	return (gp);
 }

Modified: head/sys/geom/geom_dump.c
==============================================================================
--- head/sys/geom/geom_dump.c	Mon Aug  7 19:56:09 2017	(r322195)
+++ head/sys/geom/geom_dump.c	Mon Aug  7 21:12:28 2017	(r322196)
@@ -234,6 +234,7 @@ g_conf_geom(struct sbuf *sb, struct g_geom *gp, struct
 {
 	struct g_consumer *cp2;
 	struct g_provider *pp2;
+	struct g_geom_alias *gap;
 
 	sbuf_printf(sb, "    <geom id=\"%p\">\n", gp);
 	sbuf_printf(sb, "      <class ref=\"%p\"/>\n", gp->class);
@@ -258,6 +259,11 @@ g_conf_geom(struct sbuf *sb, struct g_geom *gp, struct
 		if (pp != NULL && pp != pp2)
 			continue;
 		g_conf_provider(sb, pp2);
+	}
+	LIST_FOREACH(gap, &gp->aliases, ga_next) {
+		sbuf_printf(sb, "      <alias>\n");
+		g_conf_printf_escaped(sb, "%s", gap->ga_alias);
+		sbuf_printf(sb, "      </alias>\n");
 	}
 	sbuf_printf(sb, "    </geom>\n");
 }

Modified: head/sys/geom/geom_subr.c
==============================================================================
--- head/sys/geom/geom_subr.c	Mon Aug  7 19:56:09 2017	(r322195)
+++ head/sys/geom/geom_subr.c	Mon Aug  7 21:12:28 2017	(r322196)
@@ -347,6 +347,7 @@ g_new_geomf(struct g_class *mp, const char *fmt, ...)
 	gp->rank = 1;
 	LIST_INIT(&gp->consumer);
 	LIST_INIT(&gp->provider);
+	LIST_INIT(&gp->aliases);
 	LIST_INSERT_HEAD(&mp->geom, gp, geom);
 	TAILQ_INSERT_HEAD(&geoms, gp, geoms);
 	strcpy(gp->name, sbuf_data(sb));
@@ -367,6 +368,7 @@ g_new_geomf(struct g_class *mp, const char *fmt, ...)
 void
 g_destroy_geom(struct g_geom *gp)
 {
+	struct g_geom_alias *gap, *gaptmp;
 
 	g_topology_assert();
 	G_VALID_GEOM(gp);
@@ -380,6 +382,8 @@ g_destroy_geom(struct g_geom *gp)
 	g_cancel_event(gp);
 	LIST_REMOVE(gp, geom);
 	TAILQ_REMOVE(&geoms, gp, geoms);
+	LIST_FOREACH_SAFE(gap, &gp->aliases, ga_next, gaptmp)
+		g_free(gap);
 	g_free(gp->name);
 	g_free(gp);
 }
@@ -1210,6 +1214,18 @@ g_compare_names(const char *namea, const char *nameb)
 	if (strcmp(namea + deva, nameb + devb) == 0)
 		return (1);
 	return (0);
+}
+
+void
+g_geom_add_alias(struct g_geom *gp, const char *alias)
+{
+	struct g_geom_alias *gap;
+
+	gap = (struct g_geom_alias *)g_malloc(
+		sizeof(struct g_geom_alias) + strlen(alias) + 1, M_WAITOK);
+	strcpy((char *)(gap + 1), alias);
+	gap->ga_alias = (const char *)(gap + 1);
+	LIST_INSERT_HEAD(&gp->aliases, gap, ga_next);
 }
 
 #if defined(DIAGNOSTIC) || defined(DDB)