MFC r284582:

Fix off-by-one error in fstyp(8) and geom_label(4) that made them use
a single space (" ") as a CD9660 label name when no label was present.
Similar problem was also present in msdosfs label recognition.

Sponsored by:	The FreeBSD Foundation

4 files changed, 19 insertions, 18 deletions

diff --git a/sys/geom/label/g_label.c b/sys/geom/label/g_label.c
index fc16f7f..553643a 100644
--- a/sys/geom/label/g_label.c
+++ b/sys/geom/label/g_label.c
@@ -38,6 +38,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/malloc.h>
 #include <sys/libkern.h>
 #include <sys/sbuf.h>
+#include <sys/stddef.h>
 #include <sys/sysctl.h>
 #include <geom/geom.h>
 #include <geom/geom_slice.h>
@@ -93,6 +94,20 @@ const struct g_label_desc *g_labels[] = {
 	NULL
 };
 
+void
+g_label_rtrim(char *label, size_t size)
+{
+	ptrdiff_t i;
+
+	for (i = size - 1; i >= 0; i--) {
+		if (label[i] == '\0')
+			continue;
+		else if (label[i] == ' ')
+			label[i] = '\0';
+		else
+			break;
+	}
+}
 
 static int
 g_label_destroy_geom(struct gctl_req *req __unused, struct g_class *mp,
diff --git a/sys/geom/label/g_label.h b/sys/geom/label/g_label.h
index eca3126..ff7b035 100644
--- a/sys/geom/label/g_label.h
+++ b/sys/geom/label/g_label.h
@@ -88,6 +88,8 @@ extern struct g_label_desc g_label_ntfs;
 extern struct g_label_desc g_label_gpt;
 extern struct g_label_desc g_label_gpt_uuid;
 extern struct g_label_desc g_label_disk_ident;
+
+extern void g_label_rtrim(char *label, size_t size);
 #endif	/* _KERNEL */
 
 struct g_label_metadata {
diff --git a/sys/geom/label/g_label_iso9660.c b/sys/geom/label/g_label_iso9660.c
index 154cefc..c3c49b0 100644
--- a/sys/geom/label/g_label_iso9660.c
+++ b/sys/geom/label/g_label_iso9660.c
@@ -47,7 +47,6 @@ g_label_iso9660_taste(struct g_consumer *cp, char *label, size_t size)
 {
 	struct g_provider *pp;
 	char *sector, *volume;
-	int i;
 
 	g_topology_assert_not();
 	pp = cp->provider;
@@ -68,14 +67,7 @@ g_label_iso9660_taste(struct g_consumer *cp, char *label, size_t size)
 	bzero(label, size);
 	strlcpy(label, volume, MIN(size, VOLUME_LEN));
 	g_free(sector);
-	for (i = size - 1; i > 0; i--) {
-		if (label[i] == '\0')
-			continue;
-		else if (label[i] == ' ')
-			label[i] = '\0';
-		else
-			break;
-	}
+	g_label_rtrim(label, size);
 }
 
 struct g_label_desc g_label_iso9660 = {
diff --git a/sys/geom/label/g_label_msdosfs.c b/sys/geom/label/g_label_msdosfs.c
index 5f65a72..918fabc 100644
--- a/sys/geom/label/g_label_msdosfs.c
+++ b/sys/geom/label/g_label_msdosfs.c
@@ -48,7 +48,6 @@ g_label_msdosfs_taste(struct g_consumer *cp, char *label, size_t size)
 	FAT32_BSBPB *pfat32_bsbpb;
 	FAT_DES *pfat_entry;
 	uint8_t *sector0, *sector;
-	uint32_t i;
 
 	g_topology_assert_not();
 	pp = cp->provider;
@@ -200,14 +199,7 @@ g_label_msdosfs_taste(struct g_consumer *cp, char *label, size_t size)
 	}
 
 endofchecks:
-	for (i = size - 1; i > 0; i--) {
-		if (label[i] == '\0')
-			continue;
-		else if (label[i] == ' ')
-			label[i] = '\0';
-		else
-			break;
-	}
+	g_label_rtrim(label, size);
 
 error:
 	if (sector0 != NULL)