Add --export option to --detail to use key=value pairs.

udev likes to get information about a device as key=value pairs so it
can create disk/by-id links etc.  So add --export flag which causes
the output of --detail to easily parsable.

From: Kay Sievers <kay.sievers@novell.com>

Detail.c

@@ -31,7 +31,7 @@
 #include	"md_p.h"
 #include	"md_u.h"
 
-int Detail(char *dev, int brief, int test, char *homehost)
+int Detail(char *dev, int brief, int export, int test, char *homehost)
 {
 	/*
 	 * Print out details for an md array by using
@@ -128,7 +128,18 @@ int Detail(char *dev, int brief, int test, char *homehost)
 
 	/* Ok, we have some info to print... */
 	c = map_num(pers, array.level);
-	if (brief) 
+
+	if (export) {
+		if (c)
+			printf("MD_LEVEL=%s\n", c);
+		printf("MD_DEVICES=%d\n", array.raid_disks);
+		printf("MD_METADATA=%d.%d\n", array.major_version,
+		       array.minor_version);
+		st->ss->export_super(super);
+		goto out;
+	}
+
+	if (brief)
 		printf("ARRAY %s level=%s num-devices=%d", dev, c?c:"-unknown-",array.raid_disks );
 	else {
 		mdu_bitmap_file_t bmf;
@@ -360,6 +371,7 @@ This is pretty boring
 
 	if (brief > 1 && devices) printf("\n   devices=%s", devices);
 	if (brief) printf("\n");
+out:
 	if (test && (rv&2)) rv &= ~1;
 	close(fd);
 	return rv;

ReadMe.c

@@ -166,6 +166,7 @@ struct option long_options[] = {
 
     /* For Detail/Examine */
     {"brief",	  0, 0, 'b'},
+    {"export",	  0, 0, 'Y'},
     {"sparc2.2",  0, 0, Sparc22},
     {"test",      0, 0, 't'},
 
@@ -239,6 +240,8 @@ char OptionHelp[] =
 "  --verbose     -v   : Be more verbose about what is happening\n"
 "  --quiet       -q   : Don't print un-necessary messages\n"
 "  --brief       -b   : Be less verbose, more brief\n"
+"  --export      -Y   : With --detail, use key=value format for easy\n"
+"                       import into environment\n"
 "  --force       -f   : Override normal checks and be more forceful\n"
 "\n"
 "  --assemble    -A   : Assemble an array\n"

mdadm.8

@@ -909,6 +909,14 @@ Information about what is discovered is presented.
 .BR \-D ", " \-\-detail
 Print detail of one or more md devices.
 
+.TP
+.BR \-Y ", " \-\-export
+When used with
+.BR \-\-detail ,
+output will be formatted as
+.B key=value
+pairs for easy import into the environment.
+
 .TP
 .BR \-E ", " \-\-examine
 Print content of md superblock on device(s).

mdadm.c

@@ -74,6 +74,7 @@ int main(int argc, char *argv[])
 	int brief = 0;
 	int force = 0;
 	int test = 0;
+	int export = 0;
 	int assume_clean = 0;
 	char *symlinks = NULL;
 	/* autof indicates whether and how to create device node.
@@ -159,6 +160,9 @@ int main(int argc, char *argv[])
 			}
 			continue;
 
+		case 'Y': export++;
+			continue;
+
 		case HomeHost:
 			homehost = optarg;
 			continue;
@@ -1189,7 +1193,8 @@ int main(int argc, char *argv[])
 								e->dev);
 							continue;
 						}
-						rv |= Detail(name, verbose>1?0:verbose+1, test, homehost);
+						rv |= Detail(name, verbose>1?0:verbose+1,
+							     export, test, homehost);
 						put_md_name(name);
 					}
 				} else	if (devmode == 'S' && scan) {
@@ -1234,7 +1239,10 @@ int main(int argc, char *argv[])
 			for (dv=devlist ; dv; dv=dv->next) {
 				switch(dv->disposition) {
 				case 'D':
-					rv |= Detail(dv->devname, brief?1+verbose:0, test, homehost); continue;
+					rv |= Detail(dv->devname,
+						     brief?1+verbose:0,
+						     export, test, homehost);
+					continue;
 				case 'K': /* Zero superblock */
 					rv |= Kill(dv->devname, force, quiet); continue;
 				case 'Q':

mdadm.h

@@ -339,6 +339,7 @@ extern struct superswitch {
 	void (*examine_super)(void *sbv, char *homehost);
 	void (*brief_examine_super)(void *sbv);
 	void (*detail_super)(void *sbv, char *homehost);
+	void (*export_super)(void *sbv);
 	void (*brief_detail_super)(void *sbv);
 	void (*uuid_from_super)(int uuid[4], void *sbv);
 	void (*getinfo_super)(struct mdinfo *info, void *sbv);
@@ -443,7 +444,7 @@ extern int Create(struct supertype *st, char *mddev, int mdfd,
 		  int runstop, int verbose, int force, int assume_clean,
 		  char *bitmap_file, int bitmap_chunk, int write_behind, int delay);
 
-extern int Detail(char *dev, int brief, int test, char *homehost);
+extern int Detail(char *dev, int brief, int export, int test, char *homehost);
 extern int Query(char *dev);
 extern int Examine(mddev_dev_t devlist, int brief, int scan, int SparcAdjust,
 		   struct supertype *forcest, char *homehost);

super0.c

@@ -280,6 +280,18 @@ static void brief_detail_super0(void *sbv)
 	else
 		printf("%08x", sb->set_uuid0);
 }
+
+static void export_super0(void *sbv)
+{
+	mdp_super_t *sb = sbv;
+	printf("MD_UUID=");
+	if (sb->minor_version >= 90)
+		printf("%08x:%08x:%08x:%08x", sb->set_uuid0, sb->set_uuid1,
+		       sb->set_uuid2, sb->set_uuid3);
+	else
+		printf("%08x", sb->set_uuid0);
+	printf("\n");
+}
 #endif
 
 static int match_home0(void *sbv, char *homehost)
@@ -940,6 +952,7 @@ struct superswitch super0 = {
 	.brief_examine_super = brief_examine_super0,
 	.detail_super = detail_super0,
 	.brief_detail_super = brief_detail_super0,
+	.export_super = export_super0,
 #endif
 	.match_home = match_home0,
 	.uuid_from_super = uuid_from_super0,

super1.c

@@ -393,6 +393,28 @@ static void brief_detail_super1(void *sbv)
 	}
 }
 
+static void export_super1(void *sbv)
+{
+	struct mdp_superblock_1 *sb = sbv;
+	int i;
+	int len = 32;
+
+	for (i=0; i<32; i++)
+		if (sb->set_name[i] == '\n' ||
+		    sb->set_name[i] == '\0') {
+			len = i;
+			break;
+		}
+	if (len)
+		printf("MD_NAME=%.*s\n", len, sb->set_name);
+	printf("MD_UUID=");
+	for (i=0; i<16; i++) {
+		if ((i&3)==0 && i != 0) printf(":");
+		printf("%02x", sb->set_uuid[i]);
+	}
+	printf("\n");
+}
+
 #endif
 
 static int match_home1(void *sbv, char *homehost)
@@ -1300,6 +1322,7 @@ struct superswitch super1 = {
 	.brief_examine_super = brief_examine_super1,
 	.detail_super = detail_super1,
 	.brief_detail_super = brief_detail_super1,
+	.export_super = export_super1,
 #endif
 	.match_home = match_home1,
 	.uuid_from_super = uuid_from_super1,