From 90f2be24301fc6b17fcba2ec8f236cc0f0da607e Mon Sep 17 00:00:00 2001
From: Alexander Motin <mav@FreeBSD.org>
Date: Wed, 27 Apr 2011 00:10:26 +0000
Subject: [PATCH] Implement relaxed comparision for hardcoded provider names to
 make it ignore adX/adaY difference in both directions to simplify migration
 to the CAM-based ATA or back.

---
 sys/geom/concat/g_concat.c   |  3 ++-
 sys/geom/geom.h              |  1 +
 sys/geom/geom_subr.c         | 37 ++++++++++++++++++++++++++++++++++++
 sys/geom/journal/g_journal.c |  3 ++-
 sys/geom/mirror/g_mirror.c   |  3 ++-
 sys/geom/raid3/g_raid3.c     |  3 ++-
 sys/geom/shsec/g_shsec.c     |  3 ++-
 sys/geom/stripe/g_stripe.c   |  3 ++-
 sys/geom/virstor/g_virstor.c |  7 +++----
 9 files changed, 53 insertions(+), 10 deletions(-)

diff --git a/sys/geom/concat/g_concat.c b/sys/geom/concat/g_concat.c
index 85d8a21b3e83..10ee5713554e 100644
--- a/sys/geom/concat/g_concat.c
+++ b/sys/geom/concat/g_concat.c
@@ -678,7 +678,8 @@ g_concat_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
 	if (md.md_version < 4)
 		md.md_provsize = pp->mediasize;
 
-	if (md.md_provider[0] != '\0' && strcmp(md.md_provider, pp->name) != 0)
+	if (md.md_provider[0] != '\0' &&
+	    !g_compare_names(md.md_provider, pp->name))
 		return (NULL);
 	if (md.md_provsize != pp->mediasize)
 		return (NULL);
diff --git a/sys/geom/geom.h b/sys/geom/geom.h
index a42721eded0c..1dc6eb11ef87 100644
--- a/sys/geom/geom.h
+++ b/sys/geom/geom.h
@@ -238,6 +238,7 @@ void g_waitidlelock(void);
 /* geom_subr.c */
 int g_access(struct g_consumer *cp, int nread, int nwrite, int nexcl);
 int g_attach(struct g_consumer *cp, struct g_provider *pp);
+int g_compare_names(const char *namea, const char *nameb);
 void g_destroy_consumer(struct g_consumer *cp);
 void g_destroy_geom(struct g_geom *pp);
 void g_destroy_provider(struct g_provider *pp);
diff --git a/sys/geom/geom_subr.c b/sys/geom/geom_subr.c
index b001c5fcaed0..a0958f30da0b 100644
--- a/sys/geom/geom_subr.c
+++ b/sys/geom/geom_subr.c
@@ -1017,6 +1017,43 @@ g_getattr__(const char *attr, struct g_consumer *cp, void *var, int len)
 	return (0);
 }
 
+static int
+g_get_device_prefix_len(const char *name)
+{
+	int len;
+
+	if (strncmp(name, "ada", 3) == 0)
+		len = 3;
+	else if (strncmp(name, "ad", 2) == 0)
+		len = 2;
+	else
+		return (0);
+	if (name[len] < '0' || name[len] > '9')
+		return (0);
+	do {
+		len++;
+	} while (name[len] >= '0' && name[len] <= '9');
+	return (len);
+}
+
+int
+g_compare_names(const char *namea, const char *nameb)
+{
+	int deva, devb;
+
+	if (strcmp(namea, nameb) == 0)
+		return (1);
+	deva = g_get_device_prefix_len(namea);
+	if (deva == 0)
+		return (0);
+	devb = g_get_device_prefix_len(nameb);
+	if (devb == 0)
+		return (0);
+	if (strcmp(namea + deva, nameb + devb) == 0)
+		return (1);
+	return (0);
+}
+
 #if defined(DIAGNOSTIC) || defined(DDB)
 /*
  * This function walks the mesh and returns a non-zero integer if it
diff --git a/sys/geom/journal/g_journal.c b/sys/geom/journal/g_journal.c
index 48c03a1cd5c2..906a1e46a2ca 100644
--- a/sys/geom/journal/g_journal.c
+++ b/sys/geom/journal/g_journal.c
@@ -2527,7 +2527,8 @@ g_journal_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
 		return (NULL);
 	gp = NULL;
 
-	if (md.md_provider[0] != '\0' && strcmp(md.md_provider, pp->name) != 0)
+	if (md.md_provider[0] != '\0' &&
+	    !g_compare_names(md.md_provider, pp->name))
 		return (NULL);
 	if (md.md_provsize != 0 && md.md_provsize != pp->mediasize)
 		return (NULL);
diff --git a/sys/geom/mirror/g_mirror.c b/sys/geom/mirror/g_mirror.c
index 326851f96c9d..a2780d7c9634 100644
--- a/sys/geom/mirror/g_mirror.c
+++ b/sys/geom/mirror/g_mirror.c
@@ -3007,7 +3007,8 @@ g_mirror_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
 		return (NULL);
 	gp = NULL;
 
-	if (md.md_provider[0] != '\0' && strcmp(md.md_provider, pp->name) != 0)
+	if (md.md_provider[0] != '\0' &&
+	    !g_compare_names(md.md_provider, pp->name))
 		return (NULL);
 	if (md.md_provsize != 0 && md.md_provsize != pp->mediasize)
 		return (NULL);
diff --git a/sys/geom/raid3/g_raid3.c b/sys/geom/raid3/g_raid3.c
index 6cc20947ef54..67e44196c364 100644
--- a/sys/geom/raid3/g_raid3.c
+++ b/sys/geom/raid3/g_raid3.c
@@ -3329,7 +3329,8 @@ g_raid3_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
 		return (NULL);
 	gp = NULL;
 
-	if (md.md_provider[0] != '\0' && strcmp(md.md_provider, pp->name) != 0)
+	if (md.md_provider[0] != '\0' &&
+	    !g_compare_names(md.md_provider, pp->name))
 		return (NULL);
 	if (md.md_provsize != 0 && md.md_provsize != pp->mediasize)
 		return (NULL);
diff --git a/sys/geom/shsec/g_shsec.c b/sys/geom/shsec/g_shsec.c
index ee2cf4bab554..a2d9e1273243 100644
--- a/sys/geom/shsec/g_shsec.c
+++ b/sys/geom/shsec/g_shsec.c
@@ -673,7 +673,8 @@ g_shsec_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
 	if (md.md_version < 1)
 		md.md_provsize = pp->mediasize;
 
-	if (md.md_provider[0] != '\0' && strcmp(md.md_provider, pp->name) != 0)
+	if (md.md_provider[0] != '\0' &&
+	    !g_compare_names(md.md_provider, pp->name))
 		return (NULL);
 	if (md.md_provsize != pp->mediasize)
 		return (NULL);
diff --git a/sys/geom/stripe/g_stripe.c b/sys/geom/stripe/g_stripe.c
index add0be0f3132..b8faffdb02f8 100644
--- a/sys/geom/stripe/g_stripe.c
+++ b/sys/geom/stripe/g_stripe.c
@@ -952,7 +952,8 @@ g_stripe_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
 	if (md.md_version < 3)
 		md.md_provsize = pp->mediasize;
 
-	if (md.md_provider[0] != '\0' && strcmp(md.md_provider, pp->name) != 0)
+	if (md.md_provider[0] != '\0' &&
+	    !g_compare_names(md.md_provider, pp->name))
 		return (NULL);
 	if (md.md_provsize != pp->mediasize)
 		return (NULL);
diff --git a/sys/geom/virstor/g_virstor.c b/sys/geom/virstor/g_virstor.c
index d48a2b1ef9a1..509aca1faf2d 100644
--- a/sys/geom/virstor/g_virstor.c
+++ b/sys/geom/virstor/g_virstor.c
@@ -809,10 +809,9 @@ g_virstor_taste(struct g_class *mp, struct g_provider *pp, int flags)
 	/* If the provider name is hardcoded, use the offered provider only
 	 * if it's been offered with its proper name (the one used in
 	 * the label command). */
-	if (md.provider[0] != '\0') {
-		if (strcmp(md.provider, pp->name) != 0)
-			return (NULL);
-	}
+	if (md.provider[0] != '\0' &&
+	    !g_compare_names(md.provider, pp->name))
+		return (NULL);
 
 	/* Iterate all geoms this class already knows about to see if a new
 	 * geom instance of this class needs to be created (in case the provider