Grow: support reshape of RAID0 arrays.

This is done via conversion to RAID4 and back.

To grow the array, extra devices will be needed which cannot
already be present as spares - so allow a list of new devices
to be included in grow request which changed the number of devices.

Signed-off-by: NeilBrown <neilb@suse.de>

3 files changed, 47 insertions, 20 deletions

diff --git a/Grow.c b/Grow.c
index 812c1da..2a41428 100644
--- a/Grow.c
+++ b/Grow.c
@@ -1273,7 +1273,8 @@ char *analyse_change(struct mdinfo *info, struct reshape *re)
 
 static int reshape_array(char *container, int fd, char *devname,
 			 struct supertype *st, struct mdinfo *info,
-			 int force, char *backup_file, int quiet, int forked,
+			 int force, struct mddev_dev *devlist,
+			 char *backup_file, int quiet, int forked,
 			 int restart);
 static int reshape_container(char *container, char *devname,
 			     struct supertype *st, 
@@ -1285,6 +1286,7 @@ static int reshape_container(char *container, char *devname,
 int Grow_reshape(char *devname, int fd, int quiet, char *backup_file,
 		 long long size,
 		 int level, char *layout_str, int chunksize, int raid_disks,
+		 struct mddev_dev *devlist,
 		 int force)
 {
 	/* Make some changes in the shape of an array.
@@ -1315,6 +1317,9 @@ int Grow_reshape(char *devname, int fd, int quiet, char *backup_file,
 	char container_buf[20];
 	int cfd = -1;
 
+	struct mddev_dev *dv;
+	int added_disks;
+
 	struct mdinfo info;
 	struct mdinfo *sra;
 
@@ -1390,10 +1395,13 @@ int Grow_reshape(char *devname, int fd, int quiet, char *backup_file,
 
 		if (mdmon_running(container_dev))
 			st->update_tail = &st->updates;
-	} 
+	}
 
+	added_disks = 0;
+	for (dv = devlist; dv; dv = dv->next)
+		added_disks++;
 	if (raid_disks > array.raid_disks &&
-	    array.spare_disks < (raid_disks - array.raid_disks) &&
+	    array.spare_disks +added_disks < (raid_disks - array.raid_disks) &&
 	    !force) {
 		fprintf(stderr,
 			Name ": Need %d spare%s to avoid degraded array,"
@@ -1401,7 +1409,7 @@ int Grow_reshape(char *devname, int fd, int quiet, char *backup_file,
 			"       Use --force to over-ride this check.\n",
 			raid_disks - array.raid_disks, 
 			raid_disks - array.raid_disks == 1 ? "" : "s", 
-			array.spare_disks);
+			array.spare_disks + added_disks);
 		return 1;
 	}
 
@@ -1614,7 +1622,7 @@ int Grow_reshape(char *devname, int fd, int quiet, char *backup_file,
 		}
 		sync_metadata(st);
 		rv = reshape_array(container, fd, devname, st, &info, force,
-				   backup_file, quiet, 0, 0);
+				   devlist, backup_file, quiet, 0, 0);
 		frozen = 0;
 	}
 release:
@@ -1625,7 +1633,7 @@ release:
 
 static int reshape_array(char *container, int fd, char *devname,
 			 struct supertype *st, struct mdinfo *info,
-			 int force,
+			 int force, struct mddev_dev *devlist,
 			 char *backup_file, int quiet, int forked,
 			 int restart)
 {
@@ -1638,6 +1646,9 @@ static int reshape_array(char *container, int fd, char *devname,
 	struct mdu_array_info_s array;
 	char *c;
 
+	struct mddev_dev *dv;
+	int added_disks;
+
 	int *fdlist;
 	unsigned long long *offsets;
 	int d;
@@ -1697,20 +1708,23 @@ static int reshape_array(char *container, int fd, char *devname,
 	 */
 	sysfs_freeze_array(info);
 	/* Check we have enough spares to not be degraded */
+	added_disks = 0;
+	for (dv = devlist; dv ; dv=dv->next)
+		added_disks++;
 	spares_needed = max(reshape.before.data_disks,
 			    reshape.after.data_disks)
 		+ reshape.parity - array.raid_disks;
 
 	if (!force &&
-	    info->new_level > 1 &&
-	    spares_needed > info->array.spare_disks) {
+	    info->new_level > 1 && info->array.level > 1 &&
+	    spares_needed > info->array.spare_disks + added_disks) {
 		fprintf(stderr,
 			Name ": Need %d spare%s to avoid degraded array,"
 			" and only have %d.\n"
 			"       Use --force to over-ride this check.\n",
 			spares_needed,
 			spares_needed == 1 ? "" : "s", 
-			info->array.spare_disks);
+			info->array.spare_disks + added_disks);
 		goto release;
 	}
 	/* Check we have enough spares to not fail */
@@ -1718,13 +1732,13 @@ static int reshape_array(char *container, int fd, char *devname,
 			    reshape.after.data_disks)
 		- array.raid_disks;
 	if ((info->new_level > 1 || info->new_level == 0) &&
-	    spares_needed > info->array.spare_disks) {
+	    spares_needed > info->array.spare_disks +added_disks) {
 		fprintf(stderr,
 			Name ": Need %d spare%s to create working array,"
 			" and only have %d.\n",
 			spares_needed,
 			spares_needed == 1 ? "" : "s", 
-			info->array.spare_disks);
+			info->array.spare_disks + added_disks);
 		goto release;
 	}
 
@@ -1783,6 +1797,13 @@ static int reshape_array(char *container, int fd, char *devname,
 			sysfs_free(info2);
 		}
 	}
+	/* We might have been given some devices to add to the
+	 * array.  Now that the array has been changed to the right
+	 * level and frozen, we can safely add them.
+	 */
+	if (devlist)
+		Manage_subdevs(devname, fd, devlist, !quiet,
+			       0,NULL);
 
 	if (reshape.backup_blocks == 0) {
 		/* No restriping needed, but we might need to impose
@@ -2263,7 +2284,7 @@ int reshape_container(char *container, char *devname,
 		sysfs_init(content, fd, mdstat->devnum);
 
 		rv = reshape_array(container, fd, adev, st,
-				   content, force,
+				   content, force, NULL,
 				   backup_file, quiet, 1, restart);
 		close(fd);
 		restart = 0;
@@ -3399,5 +3420,5 @@ int Grow_continue(int mdfd, struct supertype *st, struct mdinfo *info,
 		}
 	}
 	return reshape_array(container, mdfd, "array", st, info, 1,
-			     backup_file, 0, 0, 1);
+			     NULL, backup_file, 0, 0, 1);
 }
diff --git a/mdadm.c b/mdadm.c
index 443c88a..c44c432 100644
--- a/mdadm.c
+++ b/mdadm.c
@@ -1630,22 +1630,26 @@ int main(int argc, char *argv[])
 				break;
 			}
 		}
-		if (devs_found > 1) {
-
+		if (devs_found > 1 && raiddisks == 0) {
 			/* must be '-a'. */
-			if (size >= 0 || raiddisks || chunk || layout_str != NULL || bitmap_file) {
-				fprintf(stderr, Name ": --add cannot be used with other geometry changes in --grow mode\n");
+			if (size >= 0 || chunk || layout_str != NULL || bitmap_file) {
+				fprintf(stderr, Name ": --add cannot be used with "
+					"other geometry changes in --grow mode\n");
 				rv = 1;
 				break;
 			}
 			for (dv=devlist->next; dv ; dv=dv->next) {
-				rv = Grow_Add_device(devlist->devname, mdfd, dv->devname);
+				rv = Grow_Add_device(devlist->devname, mdfd,
+						     dv->devname);
 				if (rv)
 					break;
 			}
 		} else if (bitmap_file) {
-			if (size >= 0 || raiddisks || chunk || layout_str != NULL) {
-				fprintf(stderr, Name ": --bitmap changes cannot be used with other geometry changes in --grow mode\n");
+			if (size >= 0 || raiddisks || chunk ||
+			    layout_str != NULL || devs_found) {
+				fprintf(stderr, Name ": --bitmap changes cannot be "
+					"used with other geometry changes "
+					"in --grow mode\n");
 				rv = 1;
 				break;
 			}
@@ -1657,6 +1661,7 @@ int main(int argc, char *argv[])
 			   || chunk != 0 || level != UnSet) {
 			rv = Grow_reshape(devlist->devname, mdfd, quiet, backup_file,
 					  size, level, layout_str, chunk, raiddisks,
+					  devlist->next,
 					  force);
 		} else if (array_size < 0)
 			fprintf(stderr, Name ": no changes to --grow\n");
diff --git a/mdadm.h b/mdadm.h
index db15175..fa84ad2 100644
--- a/mdadm.h
+++ b/mdadm.h
@@ -1008,6 +1008,7 @@ extern int Grow_addbitmap(char *devname, int fd, char *file, int chunk, int dela
 extern int Grow_reshape(char *devname, int fd, int quiet, char *backup_file,
 			long long size,
 			int level, char *layout_str, int chunksize, int raid_disks,
+			struct mddev_dev *devlist,
 			int force);
 extern int Grow_restart(struct supertype *st, struct mdinfo *info,
 			int *fdlist, int cnt, char *backup_file, int verbose);