lilo patch for mirrored configurations

[Erik Agsjö]

I have added basic support for mirrored targets to Christophe Saout's lilo patch.
The patch should be applied after the "lilo-22.6-devmapper.patch" and makes it
possible to run lilo on my dmraid created mirrored configuration.

The code is by no means integrated with the MD based RAID-1 support in
lilo, which of course would be neat, but it's a start.

/Erik

-----8<------

--- lilo-22.6-devmapper_patched/geometry.c	Wed Oct  6 21:34:55 2004
+++ lilo-22.6-devmapper_patched_work/geometry.c	Wed Oct  6 23:34:04 2004
@@ -930,57 +930,76 @@
 
 		if (!target_type) continue;
 
-		if (strcmp(target_type, "linear") != 0)
-		    die("device-mapper: only linear boot device supported");
-
 		target = alloc_t(DM_TARGET);
 		target->start = start;
 		target->length = length;
-		if (dm_version_nr < 4 &&
-		    isxdigit(params[0]) &&
-		    isxdigit(params[1]) &&
-		    params[2] == ':' &&
-		    isxdigit(params[3]) &&
-		    isxdigit(params[4])) { /* old 2.4 format */
-		    if (sscanf(params, "%02x:%02x %"PRIu64, &major, &minor, &target->offset) != 3)
-			die("device-mapper: parse error in linear params (\"%s\")", params);
-		} else if (isdigit(params[0]) &&
-			   strchr(params, ':')) { /* dm_bdevname/format_dev_t (>= 2.6.0-test4?) format */
-		    if (sscanf(params, "%u:%u %"PRIu64, &major, &minor, &target->offset) != 3)
-			die("device-mapper: parse error in linear params (\"%s\")", params);
-		} else { /* >= 2.5.69 format, this should go away soon */
-		    struct stat st;
-		    FILE *file;
 
-		    p = strrchr(params, ' ');
-		    if (p == NULL)
-			die("device-mapper: parse error in linear params (\"%s\")", params);
-		    *p = 0;
-		    sprintf(buf, "/dev/%s", params);	/* let's hope it's there */
-		    if (stat(buf, &st) == 0) {
-			if (!S_ISBLK(st.st_mode))
-			    die("device-mapper: %s is not a valid block device", buf);
-			major = MAJOR(st.st_rdev);
-			minor = MINOR(st.st_rdev);
-		    } else {				/* let's try sysfs */
-			int dev;
-			sprintf(buf, "/sys/block/%s/dev", params);
-			file = fopen(buf, "r");
- 			if (!file)
-			    die("device-mapper: \"%s\" could not be opened. /sys mounted?", buf);
-			if (!fgets(buf, PATH_MAX, file))
-			    die("device-mapper: read error from \"/sys/block/%s/dev\"", params);
-			if (sscanf(buf, "%u:%u", &major, &minor) != 2) {
-			    if (sscanf(buf, "%x", &dev) != 1)
-				die("device-mapper: error getting device from \"%s\"", buf);
-			    major = MAJOR(dev);
-			    minor = MINOR(dev);
+		if (strcmp(target_type, "mirror") == 0){
+		    int device_count = 0;
+		    uint64_t secondary_offset = 0;
+		    int secondary_major;
+		    int secondary_minor;
+		    if(sscanf(params, "%*s %*d %*d %*s %d %u:%u %"PRIu64" %u:%u %"PRIu64,
+			      &device_count,
+			      &major, &minor, &target->offset,
+			      &secondary_major, &secondary_minor, &secondary_offset) != 7){
+			die("device-mapper: parse error in mirror params (\"%s\")", params);
+		    }
+		    if(device_count > 2){
+			die("device-mapper: mirrors of more than 2 devices not supported");
+		    }
+		    if(secondary_offset != target->offset){
+			die("device-mapper: skewed mirrors not supported");
+		    }
+		} else if (strcmp(target_type, "linear") == 0) {
+		    if (dm_version_nr < 4 &&
+			isxdigit(params[0]) &&
+			isxdigit(params[1]) &&
+			params[2] == ':' &&
+			isxdigit(params[3]) &&
+			isxdigit(params[4])) { /* old 2.4 format */
+			if (sscanf(params, "%02x:%02x %"PRIu64, &major, &minor, &target->offset) != 3)
+			    die("device-mapper: parse error in linear params (\"%s\")", params);
+		    } else if (isdigit(params[0]) &&
+			       strchr(params, ':')) { /* dm_bdevname/format_dev_t (>= 2.6.0-test4?) format */
+			if (sscanf(params, "%u:%u %"PRIu64, &major, &minor, &target->offset) != 3)
+			    die("device-mapper: parse error in linear params (\"%s\")", params);
+		    } else { /* >= 2.5.69 format, this should go away soon */
+			struct stat st;
+			FILE *file;
+
+			p = strrchr(params, ' ');
+			if (p == NULL)
+			    die("device-mapper: parse error in linear params (\"%s\")", params);
+			*p = 0;
+			sprintf(buf, "/dev/%s", params);	/* let's hope it's there */
+			if (stat(buf, &st) == 0) {
+			    if (!S_ISBLK(st.st_mode))
+				die("device-mapper: %s is not a valid block device", buf);
+			    major = MAJOR(st.st_rdev);
+			    minor = MINOR(st.st_rdev);
+			} else {				/* let's try sysfs */
+			    int dev;
+			    sprintf(buf, "/sys/block/%s/dev", params);
+			    file = fopen(buf, "r");
+			    if (!file)
+				die("device-mapper: \"%s\" could not be opened. /sys mounted?", buf);
+			    if (!fgets(buf, PATH_MAX, file))
+				die("device-mapper: read error from \"/sys/block/%s/dev\"", params);
+			    if (sscanf(buf, "%u:%u", &major, &minor) != 2) {
+				if (sscanf(buf, "%x", &dev) != 1)
+				    die("device-mapper: error getting device from \"%s\"", buf);
+				major = MAJOR(dev);
+				minor = MINOR(dev);
+			    }
+			    (void) fclose(file);
 			}
-			(void) fclose(file);
+			*p = ' ';
+			if (sscanf(p+1, "%"PRIu64, &target->offset) != 1)
+			    die("device-mapper: parse error in linear params (\"%s\")", params);
 		    }
-		    *p = ' ';
-		    if (sscanf(p+1, "%"PRIu64, &target->offset) != 1)
-			die("device-mapper: parse error in linear params (\"%s\")", params);
+		}else{
+		    die("device-mapper: only mirror or linear boot device supported");
 		}
 		target->device = (major << 8) | minor;
 		if (!device)