Initial DDF support code.

Create a ddf array by naming the device /dev/ddf* or
specifying metadata 'ddf'.

If ddf is specified with no level, assume a container (indeed,
anything else would be wrong).

**Need to use text_Version to set external metadata...

More ddf support

Load a ddf container.  Now
   --examine /dev/ddf
works.
super-ddf: fix compile warning

From: Dan Williams <dan.j.williams@intel.com>

super-ddf.c:723: format %lu expects type long unsigned int, but argument 3 has type unsigned int

Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Create.c

@@ -92,6 +92,14 @@ int Create(struct supertype *st, char *mddev, int mdfd,
 			return 1;
 		}
 	}
+	if (level == UnSet) {
+		/* "ddf" metadata only supports one level - should possibly
+		 * push this into metadata handler??
+		 */
+		if (st && st->ss == &super_ddf)
+			level = LEVEL_CONTAINER;
+	}
+
 	if (level == UnSet) {
 		fprintf(stderr,
 			Name ": a RAID level is needed to create an array.\n");

Makefile

@@ -69,18 +69,19 @@ MAN8DIR = $(MANDIR)/man8
 OBJS =  mdadm.o config.o mdstat.o  ReadMe.o util.o Manage.o Assemble.o Build.o \
 	Create.o Detail.o Examine.o Grow.o Monitor.o dlink.o Kill.o Query.o \
 	Incremental.o \
-	mdopen.o super0.o super1.o bitmap.o restripe.o sysfs.o sha1.o \
-	mapfile.o crc32.o
+	mdopen.o super0.o super1.o super-ddf.o bitmap.o restripe.o sysfs.o \
+	sha1.o mapfile.o crc32.o
 SRCS =  mdadm.c config.c mdstat.c  ReadMe.c util.c Manage.c Assemble.c Build.c \
 	Create.c Detail.c Examine.c Grow.c Monitor.c dlink.c Kill.c Query.c \
 	Incremental.c \
-	mdopen.c super0.c super1.c bitmap.c restripe.c sysfs.c sha1.c \
-	mapfile.c crc32.c
+	mdopen.c super0.c super1.c super-ddf.c bitmap.c restripe.c sysfs.c \
+	sha1.c mapfile.c crc32.c
 
 STATICSRC = pwgr.c
 STATICOBJS = pwgr.o
 
-ASSEMBLE_SRCS := mdassemble.c Assemble.c Manage.c config.c dlink.c util.c super0.c super1.c sha1.c
+ASSEMBLE_SRCS := mdassemble.c Assemble.c Manage.c config.c dlink.c util.c \
+	super0.c super1.c super-ddf.c sha1.c crc32.c
 ASSEMBLE_FLAGS:= $(CFLAGS) -DMDASSEMBLE
 ifdef MDASSEMBLE_AUTO
 ASSEMBLE_SRCS += mdopen.c mdstat.c

TODO

@@ -1,3 +1,38 @@
+ - add 'name' field to metadata type and use it.
+ - use validate_geometry more
+ - metadata should be able to check/reject bitmap stuff.
+
+DDF:
+  Three new metadata types:
+    ddf - used only to create a container.
+    ddf-bvd - used to create an array in a container
+    ddf-svd - used to create a secondary array from bvds.
+
+  Usage:
+    mdadm -C /dev/ddf1 /dev/sd[abcdef]
+    mdadm -C /dev/md1 -e ddf /dev/sd[a-f]
+    mdadm -C /dev/md1 -l container /dev/sd[a-f]
+
+        Each of these create a new ddf container using all those
+	devices.  The name 'ddf*' signals that ddf metadata should be used.
+	'-e ddf' only supports one level - 'container'.  'container' is only
+	supported by ddf.
+
+    mdadm -C /dev/md1 -l0 -n4 /dev/ddf1 # or maybe not ???
+    mdadm -C /dev/md1 -l1 -n2 /dev/sda /dev/sdb
+	If exactly one device is given, and it is a container, we select
+	devices from that container.
+	If devices are given that are already in use, they must be in use by
+	a container, and the array is created in the container.
+	If devices given are bvds, we slip under the hood to make
+	  the svd arrays.
+
+    mdadm -A /dev/ddf ......
+	base drives make a container.  Anything in that container is started
+	 auto-read-only.
+	 if /dev/ddf is already assembled, we assemble bvds and svds inside it.
+
+
 2005-dec-20
   Want an incremental assembly mode to work nicely with udev.
   Core usage would be something like

mdadm.h

@@ -380,7 +380,7 @@ extern struct superswitch {
 	char *text_version;
 	int swapuuid; /* true if uuid is bigending rather than hostendian */
 	int external;
-} super0, super1, *superlist[];
+} super0, super1, super_ddf, super_ddf_bvd, super_ddf_svd, *superlist[];
 
 struct supertype {
 	struct superswitch *ss;
@@ -546,6 +546,7 @@ extern char DefaultConfFile[];
 extern int open_mddev(char *dev, int autof);
 extern int open_mddev_devnum(char *devname, int devnum, char *name,
 			     char *chosen_name, int parts);
+extern int open_container(int fd);
 
 
 #define	LEVEL_MULTIPATH		(-4)
@@ -554,6 +555,7 @@ extern int open_mddev_devnum(char *devname, int devnum, char *name,
 
 /* kernel module doesn't know about these */
 #define LEVEL_CONTAINER		(-100)
+#define	LEVEL_UNSUPPORTED	(-200)
 
 
 /* faulty stuff */

util.c

@@ -31,6 +31,7 @@
 #include	"md_p.h"
 #include	<sys/utsname.h>
 #include	<ctype.h>
+#include	<dirent.h>
 
 /*
  * following taken from linux/blkpg.h because they aren't
@@ -759,7 +760,7 @@ int dev_open(char *dev, int flags)
 	return fd;
 }
 
-struct superswitch *superlist[] = { &super0, &super1, NULL };
+struct superswitch *superlist[] = { &super0, &super1, &super_ddf, NULL };
 
 #if !defined(MDASSEMBLE) || defined(MDASSEMBLE) && defined(MDASSEMBLE_AUTO)
 struct supertype *super_by_fd(int fd)
@@ -908,6 +909,55 @@ void get_one_disk(int mdfd, mdu_array_info_t *ainf, mdu_disk_info_t *disk)
 			return;
 }
 
+int open_container(int fd)
+{
+	/* 'fd' is a block device.  Find out if it is in use
+	 * by a container, and return an open fd on that container.
+	 */
+	char path[256];
+	char *e;
+	DIR *dir;
+	struct dirent *de;
+	int dfd, n;
+	char buf[200];
+	int major, minor;
+	struct stat st;
+
+	if (fstat(fd, &st) != 0)
+		return -1;
+	sprintf(path, "/sys/dev/block/%d:%d/holders",
+		(int)major(st.st_rdev), (int)minor(st.st_rdev));
+	e = path + strlen(path);
+
+	dir = opendir(path);
+	if (!dir)
+		return -1;
+	while ((de = readdir(dir))) {
+		if (de->d_ino == 0)
+			continue;
+		if (de->d_name[0] == '.')
+			continue;
+		sprintf(e, "/%s/dev", de->d_name);
+		dfd = open(path, O_RDONLY);
+		if (dfd < 0)
+			continue;
+		n = read(dfd, buf, sizeof(buf));
+		close(dfd);
+		if (n <= 0 || n >= sizeof(buf))
+			continue;
+		buf[n] = 0;
+		if (sscanf(buf, "%d:%d", &major, &minor) != 2)
+			continue;
+		sprintf(buf, "%d:%d", major, minor);
+		dfd = dev_open(buf, O_RDONLY);
+		if (dfd >= 0) {
+			closedir(dir);
+			return dfd;
+		}
+	}
+	return -1;
+}
+
 #ifdef __TINYC__
 /* tinyc doesn't optimize this check in ioctl.h out ... */
 unsigned int __invalid_size_argument_for_IOC = 0;