Fix --grow --add for linear arrays.

The new superblock needs to have a new disk.number.  This is a bit of a hack...
Fix handling of negative bitmap offsets on 64bit hosts.

The bitmap offset is a signed 32bit number, so casting to (long)
isn't sufficient.  We must cast to (int32_t).
Fix various problems with --grow --add for linear.

The code to add a drive to a live linear array had never
been tested properly and so was buggy.  This tidies it up
and means that the new regression-test passes.

4 files changed, 45 insertions, 15 deletions

diff --git a/ChangeLog b/ChangeLog
index caa25391..a25463e2 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -6,6 +6,7 @@ Changes Prior to this release
     -   fix internal bitmap allocation problems with v1.1, v1.2 metadata.
     -   --help now goes to stdout so you can direct it to a pager.
     -   Various manpage updates.
+    -   Make "--grow --add" for linear arrays really work.
 
 Changes Prior to 2.6.1 release
     -   --monitor was producing some meaningless warnings due to a bug.
diff --git a/Grow.c b/Grow.c
index c160f2c6..c28c1ac5 100644
--- a/Grow.c
+++ b/Grow.c
@@ -121,10 +121,12 @@ int Grow_Add_device(char *devname, int fd, char *newdev)
 	info.disk.minor = minor(stb.st_rdev);
 	info.disk.raid_disk = d;
 	info.disk.state = (1 << MD_DISK_SYNC) | (1 << MD_DISK_ACTIVE);
-	st->ss->update_super(&info, super, "grow", newdev, 0, 0, NULL);
+	st->ss->update_super(&info, super, "linear-grow-new", newdev,
+			     0, 0, NULL);
 
 	if (st->ss->store_super(st, nfd, super)) {
-		fprintf(stderr, Name ": Cannot store new superblock on %s\n", newdev);
+		fprintf(stderr, Name ": Cannot store new superblock on %s\n",
+			newdev);
 		close(nfd);
 		return 1;
 	}
@@ -174,12 +176,9 @@ int Grow_Add_device(char *devname, int fd, char *newdev)
 		info.array.nr_disks = nd+1;
 		info.array.active_disks = nd+1;
 		info.array.working_disks = nd+1;
-		info.disk.number = nd;
-		info.disk.major = major(stb.st_rdev);
-		info.disk.minor = minor(stb.st_rdev);
-		info.disk.raid_disk = nd;
-		info.disk.state = (1 << MD_DISK_SYNC) | (1 << MD_DISK_ACTIVE);
-		st->ss->update_super(&info, super, "grow", dv, 0, 0, NULL);
+
+		st->ss->update_super(&info, super, "linear-grow-update", dv,
+				     0, 0, NULL);
 		
 		if (st->ss->store_super(st, fd2, super)) {
 			fprintf(stderr, Name ": Cannot store new superblock on %s\n", dv);
diff --git a/super0.c b/super0.c
index 5828e15b..30da8aa2 100644
--- a/super0.c
+++ b/super0.c
@@ -459,7 +459,16 @@ static int update_super0(struct mdinfo *info, void *sbv, char *update,
 			rv = 1;
 		}
 	}
-	if (strcmp(update, "grow") == 0) {
+	if (strcmp(update, "linear-grow-new") == 0) {
+		memset(&sb->disks[info->disk.number], 0, sizeof(sb->disks[0]));
+		sb->disks[info->disk.number].number = info->disk.number;
+		sb->disks[info->disk.number].major = info->disk.major;
+		sb->disks[info->disk.number].minor = info->disk.minor;
+		sb->disks[info->disk.number].raid_disk = info->disk.raid_disk;
+		sb->disks[info->disk.number].state = info->disk.state;
+		sb->this_disk = sb->disks[info->disk.number];
+	}
+	if (strcmp(update, "linear-grow-update") == 0) {
 		sb->raid_disks = info->array.raid_disks;
 		sb->nr_disks = info->array.nr_disks;
 		sb->active_disks = info->array.active_disks;
@@ -470,8 +479,6 @@ static int update_super0(struct mdinfo *info, void *sbv, char *update,
 		sb->disks[info->disk.number].minor = info->disk.minor;
 		sb->disks[info->disk.number].raid_disk = info->disk.raid_disk;
 		sb->disks[info->disk.number].state = info->disk.state;
-		if (sb->this_disk.number == info->disk.number)
-			sb->this_disk = sb->disks[info->disk.number];
 	}
 	if (strcmp(update, "resync") == 0) {
 		/* make sure resync happens */
diff --git a/super1.c b/super1.c
index 5995bb61..0e70e1e9 100644
--- a/super1.c
+++ b/super1.c
@@ -549,11 +549,34 @@ static int update_super1(struct mdinfo *info, void *sbv, char *update,
 			rv = 1;
 		}
 	}
-	if (strcmp(update, "grow") == 0) {
+	if (strcmp(update, "linear-grow-new") == 0) {
+		int i;
+		int rfd;
+		int max = __le32_to_cpu(sb->max_dev);
+
+		for (i=0 ; i < max ; i++)
+			if (__le16_to_cpu(sb->dev_roles[i]) >= 0xfffe)
+				break;
+		sb->dev_number = __cpu_to_le32(i);
+		info->disk.number = i;
+		if (max >= __le32_to_cpu(sb->max_dev))
+			sb->max_dev = __cpu_to_le32(max+1);
+
+		if ((rfd = open("/dev/urandom", O_RDONLY)) < 0 ||
+		    read(rfd, sb->device_uuid, 16) != 16) {
+			*(__u32*)(sb->device_uuid) = random();
+			*(__u32*)(sb->device_uuid+4) = random();
+			*(__u32*)(sb->device_uuid+8) = random();
+			*(__u32*)(sb->device_uuid+12) = random();
+		}
+
+		sb->dev_roles[i] =
+			__cpu_to_le16(info->disk.raid_disk);
+	}
+	if (strcmp(update, "linear-grow-update") == 0) {
 		sb->raid_disks = __cpu_to_le32(info->array.raid_disks);
-		/* As we are just adding a spare, there is no need to
-		 * make any change to the dev_roles array
-		 */
+		sb->dev_roles[info->disk.number] =
+			__cpu_to_le16(info->disk.raid_disk);
 	}
 	if (strcmp(update, "resync") == 0) {
 		/* make sure resync happens */