Adding upstream version 4.3.upstream/4.3

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1340 insertions, 0 deletions

diff --git a/Create.c b/Create.c
new file mode 100644
index 0000000..8082f54
--- /dev/null
+++ b/Create.c
@@ -0,0 +1,1340 @@
+/*
+ * mdadm - manage Linux "md" devices aka RAID arrays.
+ *
+ * Copyright (C) 2001-2013 Neil Brown <neilb@suse.de>
+ *
+ *
+ *    This program is free software; you can redistribute it and/or modify
+ *    it under the terms of the GNU General Public License as published by
+ *    the Free Software Foundation; either version 2 of the License, or
+ *    (at your option) any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License
+ *    along with this program; if not, write to the Free Software
+ *    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ *    Author: Neil Brown
+ *    Email: <neilb@suse.de>
+ */
+
+#include	"mdadm.h"
+#include	"udev.h"
+#include	"md_u.h"
+#include	"md_p.h"
+#include	<ctype.h>
+#include	<fcntl.h>
+#include	<signal.h>
+#include	<sys/signalfd.h>
+#include	<sys/wait.h>
+
+static int round_size_and_verify(unsigned long long *size, int chunk)
+{
+	if (*size == 0)
+		return 0;
+	*size &= ~(unsigned long long)(chunk - 1);
+	if (*size == 0) {
+		pr_err("Size cannot be smaller than chunk.\n");
+		return 1;
+	}
+	return 0;
+}
+
+/**
+ * default_layout() - Get default layout for level.
+ * @st: metadata requested, could be NULL.
+ * @level: raid level requested.
+ * @verbose: verbose level.
+ *
+ * Try to ask metadata handler first, otherwise use global defaults.
+ *
+ * Return: Layout or &UnSet, return value meaning depends of level used.
+ */
+int default_layout(struct supertype *st, int level, int verbose)
+{
+	int layout = UnSet;
+	mapping_t *layout_map = NULL;
+	char *layout_name = NULL;
+
+	if (st && st->ss->default_geometry)
+		st->ss->default_geometry(st, &level, &layout, NULL);
+
+	if (layout != UnSet)
+		return layout;
+
+	switch (level) {
+	default: /* no layout */
+		layout = 0;
+		break;
+	case 0:
+		layout = RAID0_ORIG_LAYOUT;
+		break;
+	case 10:
+		layout = 0x102; /* near=2, far=1 */
+		layout_name = "n2";
+		break;
+	case 5:
+	case 6:
+		layout_map = r5layout;
+		break;
+	case LEVEL_FAULTY:
+		layout_map = faultylayout;
+		break;
+	}
+
+	if (layout_map) {
+		layout = map_name(layout_map, "default");
+		layout_name = map_num_s(layout_map, layout);
+	}
+	if (layout_name && verbose > 0)
+		pr_err("layout defaults to %s\n", layout_name);
+
+	return layout;
+}
+
+static pid_t write_zeroes_fork(int fd, struct shape *s, struct supertype *st,
+			       struct mddev_dev *dv)
+
+{
+	const unsigned long long req_size = 1 << 30;
+	unsigned long long offset_bytes, size_bytes, sz;
+	sigset_t sigset;
+	int ret = 0;
+	pid_t pid;
+
+	size_bytes = KIB_TO_BYTES(s->size);
+
+	/*
+	 * If size_bytes is zero, this is a zoned raid array where
+	 * each disk is of a different size and uses its full
+	 * disk. Thus zero the entire disk.
+	 */
+	if (!size_bytes && !get_dev_size(fd, dv->devname, &size_bytes))
+		return -1;
+
+	if (dv->data_offset != INVALID_SECTORS)
+		offset_bytes = SEC_TO_BYTES(dv->data_offset);
+	else
+		offset_bytes = SEC_TO_BYTES(st->data_offset);
+
+	pr_info("zeroing data from %lld to %lld on: %s\n",
+		offset_bytes, size_bytes, dv->devname);
+
+	pid = fork();
+	if (pid < 0) {
+		pr_err("Could not fork to zero disks: %s\n", strerror(errno));
+		return pid;
+	} else if (pid != 0) {
+		return pid;
+	}
+
+	sigemptyset(&sigset);
+	sigaddset(&sigset, SIGINT);
+	sigprocmask(SIG_UNBLOCK, &sigset, NULL);
+
+	while (size_bytes) {
+		/*
+		 * Split requests to the kernel into 1GB chunks seeing the
+		 * fallocate() call is not interruptible and blocking a
+		 * ctrl-c for several minutes is not desirable.
+		 *
+		 * 1GB is chosen as a compromise: the user may still have
+		 * to wait several seconds if they ctrl-c on devices that
+		 * zero slowly, but will reduce the number of requests
+		 * required and thus the overhead on devices that perform
+		 * better.
+		 */
+		sz = size_bytes;
+		if (sz >= req_size)
+			sz = req_size;
+
+		if (fallocate(fd, FALLOC_FL_ZERO_RANGE | FALLOC_FL_KEEP_SIZE,
+			      offset_bytes, sz)) {
+			pr_err("zeroing %s failed: %s\n", dv->devname,
+			       strerror(errno));
+			ret = 1;
+			break;
+		}
+
+		offset_bytes += sz;
+		size_bytes -= sz;
+	}
+
+	exit(ret);
+}
+
+static int wait_for_zero_forks(int *zero_pids, int count)
+{
+	int wstatus, ret = 0, i, sfd, wait_count = 0;
+	struct signalfd_siginfo fdsi;
+	bool interrupted = false;
+	sigset_t sigset;
+	ssize_t s;
+
+	for (i = 0; i < count; i++)
+		if (zero_pids[i])
+			wait_count++;
+	if (!wait_count)
+		return 0;
+
+	sigemptyset(&sigset);
+	sigaddset(&sigset, SIGINT);
+	sigaddset(&sigset, SIGCHLD);
+	sigprocmask(SIG_BLOCK, &sigset, NULL);
+
+	sfd = signalfd(-1, &sigset, 0);
+	if (sfd < 0) {
+		pr_err("Unable to create signalfd: %s\n", strerror(errno));
+		return 1;
+	}
+
+	while (1) {
+		s = read(sfd, &fdsi, sizeof(fdsi));
+		if (s != sizeof(fdsi)) {
+			pr_err("Invalid signalfd read: %s\n", strerror(errno));
+			close(sfd);
+			return 1;
+		}
+
+		if (fdsi.ssi_signo == SIGINT) {
+			printf("\n");
+			pr_info("Interrupting zeroing processes, please wait...\n");
+			interrupted = true;
+		} else if (fdsi.ssi_signo == SIGCHLD) {
+			if (!--wait_count)
+				break;
+		}
+	}
+
+	close(sfd);
+
+	for (i = 0; i < count; i++) {
+		if (!zero_pids[i])
+			continue;
+
+		waitpid(zero_pids[i], &wstatus, 0);
+		zero_pids[i] = 0;
+		if (!WIFEXITED(wstatus) || WEXITSTATUS(wstatus))
+			ret = 1;
+	}
+
+	if (interrupted) {
+		pr_err("zeroing interrupted!\n");
+		return 1;
+	}
+
+	if (ret)
+		pr_err("zeroing failed!\n");
+	else
+		pr_info("zeroing finished\n");
+
+	return ret;
+}
+
+static int add_disk_to_super(int mdfd, struct shape *s, struct context *c,
+		struct supertype *st, struct mddev_dev *dv,
+		struct mdinfo *info, int have_container, int major_num,
+		int *zero_pid)
+{
+	dev_t rdev;
+	int fd;
+
+	if (dv->disposition == 'j') {
+		info->disk.raid_disk = MD_DISK_ROLE_JOURNAL;
+		info->disk.state = (1<<MD_DISK_JOURNAL);
+	} else if (info->disk.raid_disk < s->raiddisks) {
+		info->disk.state = (1<<MD_DISK_ACTIVE) |
+			(1<<MD_DISK_SYNC);
+	} else {
+		info->disk.state = 0;
+	}
+
+	if (dv->writemostly == FlagSet) {
+		if (major_num == BITMAP_MAJOR_CLUSTERED) {
+			pr_err("Can not set %s --write-mostly with a clustered bitmap\n",dv->devname);
+			return 1;
+		} else {
+			info->disk.state |= (1<<MD_DISK_WRITEMOSTLY);
+		}
+
+	}
+
+	if (dv->failfast == FlagSet)
+		info->disk.state |= (1<<MD_DISK_FAILFAST);
+
+	if (have_container) {
+		fd = -1;
+	} else {
+		if (st->ss->external && st->container_devnm[0])
+			fd = open(dv->devname, O_RDWR);
+		else
+			fd = open(dv->devname, O_RDWR|O_EXCL);
+
+		if (fd < 0) {
+			pr_err("failed to open %s after earlier success - aborting\n",
+			       dv->devname);
+			return 1;
+		}
+		if (!fstat_is_blkdev(fd, dv->devname, &rdev))
+			return 1;
+		info->disk.major = major(rdev);
+		info->disk.minor = minor(rdev);
+	}
+	if (fd >= 0)
+		remove_partitions(fd);
+	if (st->ss->add_to_super(st, &info->disk, fd, dv->devname,
+				 dv->data_offset)) {
+		ioctl(mdfd, STOP_ARRAY, NULL);
+		return 1;
+	}
+	st->ss->getinfo_super(st, info, NULL);
+
+	if (fd >= 0 && s->write_zeroes) {
+		*zero_pid = write_zeroes_fork(fd, s, st, dv);
+		if (*zero_pid <= 0) {
+			ioctl(mdfd, STOP_ARRAY, NULL);
+			return 1;
+		}
+	}
+
+	if (have_container && c->verbose > 0)
+		pr_err("Using %s for device %d\n",
+		       map_dev(info->disk.major, info->disk.minor, 0),
+		       info->disk.number);
+
+	if (!have_container) {
+		/* getinfo_super might have lost these ... */
+		info->disk.major = major(rdev);
+		info->disk.minor = minor(rdev);
+	}
+
+	return 0;
+}
+
+static int update_metadata(int mdfd, struct shape *s, struct supertype *st,
+			   struct map_ent **map, struct mdinfo *info,
+			   char *chosen_name)
+{
+	struct mdinfo info_new;
+	struct map_ent *me = NULL;
+
+	/* check to see if the uuid has changed due to these
+	 * metadata changes, and if so update the member array
+	 * and container uuid.  Note ->write_init_super clears
+	 * the subarray cursor such that ->getinfo_super once
+	 * again returns container info.
+	 */
+	st->ss->getinfo_super(st, &info_new, NULL);
+	if (st->ss->external && !is_container(s->level) &&
+	    !same_uuid(info_new.uuid, info->uuid, 0)) {
+		map_update(map, fd2devnm(mdfd),
+			   info_new.text_version,
+			   info_new.uuid, chosen_name);
+		me = map_by_devnm(map, st->container_devnm);
+	}
+
+	if (st->ss->write_init_super(st)) {
+		st->ss->free_super(st);
+		return 1;
+	}
+
+	/*
+	 * Before activating the array, perform extra steps
+	 * required to configure the internal write-intent
+	 * bitmap.
+	 */
+	if (info_new.consistency_policy == CONSISTENCY_POLICY_BITMAP &&
+	    st->ss->set_bitmap && st->ss->set_bitmap(st, info)) {
+		st->ss->free_super(st);
+		return 1;
+	}
+
+	/* update parent container uuid */
+	if (me) {
+		char *path = xstrdup(me->path);
+
+		st->ss->getinfo_super(st, &info_new, NULL);
+		map_update(map, st->container_devnm, info_new.text_version,
+			   info_new.uuid, path);
+		free(path);
+	}
+
+	flush_metadata_updates(st);
+	st->ss->free_super(st);
+
+	return 0;
+}
+
+static int add_disks(int mdfd, struct mdinfo *info, struct shape *s,
+		     struct context *c, struct supertype *st,
+		     struct map_ent **map, struct mddev_dev *devlist,
+		     int total_slots, int have_container, int insert_point,
+		     int major_num, char *chosen_name)
+{
+	struct mddev_dev *moved_disk = NULL;
+	int pass, raid_disk_num, dnum;
+	int zero_pids[total_slots];
+	struct mddev_dev *dv;
+	struct mdinfo *infos;
+	sigset_t sigset, orig_sigset;
+	int ret = 0;
+
+	/*
+	 * Block SIGINT so the main thread will always wait for the
+	 * zeroing processes when being interrupted. Otherwise the
+	 * zeroing processes will finish their work in the background
+	 * keeping the disk busy.
+	 */
+	sigemptyset(&sigset);
+	sigaddset(&sigset, SIGINT);
+	sigprocmask(SIG_BLOCK, &sigset, &orig_sigset);
+	memset(zero_pids, 0, sizeof(zero_pids));
+
+	infos = xmalloc(sizeof(*infos) * total_slots);
+	enable_fds(total_slots);
+	for (pass = 1; pass <= 2; pass++) {
+		for (dnum = 0, raid_disk_num = 0, dv = devlist; dv;
+		     dv = (dv->next) ? (dv->next) : moved_disk, dnum++) {
+			if (dnum >= total_slots)
+				abort();
+			if (dnum == insert_point) {
+				raid_disk_num += 1;
+				moved_disk = dv;
+				continue;
+			}
+			if (strcasecmp(dv->devname, "missing") == 0) {
+				raid_disk_num += 1;
+				continue;
+			}
+			if (have_container)
+				moved_disk = NULL;
+			if (have_container && dnum < total_slots - 1)
+				/* repeatedly use the container */
+				moved_disk = dv;
+
+			switch(pass) {
+			case 1:
+				infos[dnum] = *info;
+				infos[dnum].disk.number = dnum;
+				infos[dnum].disk.raid_disk = raid_disk_num++;
+
+				if (dv->disposition == 'j')
+					raid_disk_num--;
+
+				ret = add_disk_to_super(mdfd, s, c, st, dv,
+						&infos[dnum], have_container,
+						major_num, &zero_pids[dnum]);
+				if (ret)
+					goto out;
+
+				break;
+			case 2:
+				infos[dnum].errors = 0;
+
+				ret = add_disk(mdfd, st, info, &infos[dnum]);
+				if (ret) {
+					pr_err("ADD_NEW_DISK for %s failed: %s\n",
+					       dv->devname, strerror(errno));
+					if (errno == EINVAL &&
+					    info->array.level == 0) {
+						pr_err("Possibly your kernel doesn't support RAID0 layouts.\n");
+						pr_err("Either upgrade, or use --layout=dangerous\n");
+					}
+					goto out;
+				}
+				break;
+			}
+			if (!have_container &&
+			    dv == moved_disk && dnum != insert_point) break;
+		}
+
+		if (pass == 1) {
+			ret = wait_for_zero_forks(zero_pids, total_slots);
+			if (ret)
+				goto out;
+
+			ret = update_metadata(mdfd, s, st, map, info,
+					      chosen_name);
+			if (ret)
+				goto out;
+		}
+	}
+
+out:
+	if (ret)
+		wait_for_zero_forks(zero_pids, total_slots);
+	free(infos);
+	sigprocmask(SIG_SETMASK, &orig_sigset, NULL);
+	return ret;
+}
+
+int Create(struct supertype *st, struct mddev_ident *ident, int subdevs,
+	   struct mddev_dev *devlist, struct shape *s, struct context *c)
+{
+	/*
+	 * Create a new raid array.
+	 *
+	 * First check that necessary details are available
+	 * (i.e. level, raid-disks)
+	 *
+	 * Then check each disk to see what might be on it
+	 * and report anything interesting.
+	 *
+	 * If anything looks odd, and runstop not set,
+	 * abort.
+	 *
+	 * SET_ARRAY_INFO and ADD_NEW_DISK, and
+	 * if runstop==run, or raiddisks disks were used,
+	 * RUN_ARRAY
+	 */
+	int mdfd;
+	unsigned long long minsize = 0, maxsize = 0;
+	char *mindisc = NULL;
+	char *maxdisc = NULL;
+	char *name = ident->name;
+	int *uuid = ident->uuid_set == 1 ? ident->uuid : NULL;
+	int dnum;
+	struct mddev_dev *dv;
+	dev_t rdev;
+	int fail = 0, warn = 0;
+	int first_missing = subdevs * 2;
+	int second_missing = subdevs * 2;
+	int missing_disks = 0;
+	int insert_point = subdevs * 2; /* where to insert a missing drive */
+	int total_slots;
+	int rv;
+	int bitmap_fd;
+	int have_container = 0;
+	int container_fd = -1;
+	int need_mdmon = 0;
+	unsigned long long bitmapsize;
+	struct mdinfo info;
+	int did_default = 0;
+	int do_default_layout = 0;
+	int do_default_chunk = 0;
+	char chosen_name[1024];
+	struct map_ent *map = NULL;
+	unsigned long long newsize;
+	mdu_array_info_t inf;
+
+	int major_num = BITMAP_MAJOR_HI;
+	if (s->bitmap_file && strcmp(s->bitmap_file, "clustered") == 0) {
+		major_num = BITMAP_MAJOR_CLUSTERED;
+		if (c->nodes <= 1) {
+			pr_err("At least 2 nodes are needed for cluster-md\n");
+			return 1;
+		}
+	}
+
+	memset(&info, 0, sizeof(info));
+	if (s->level == UnSet && st && st->ss->default_geometry)
+		st->ss->default_geometry(st, &s->level, NULL, NULL);
+	if (s->level == UnSet) {
+		pr_err("a RAID level is needed to create an array.\n");
+		return 1;
+	}
+	if (s->raiddisks < 4 && s->level == 6) {
+		pr_err("at least 4 raid-devices needed for level 6\n");
+		return 1;
+	}
+	if (s->raiddisks > 256 && s->level == 6) {
+		pr_err("no more than 256 raid-devices supported for level 6\n");
+		return 1;
+	}
+	if (s->raiddisks < 2 && s->level >= 4) {
+		pr_err("at least 2 raid-devices needed for level %d\n", s->level);
+		return 1;
+	}
+	if (s->level <= 0 && s->sparedisks) {
+		pr_err("This level does not support spare devices\n");
+		return 1;
+	}
+
+	if (subdevs == 1 && strcmp(devlist->devname, "missing") != 0) {
+		/* If given a single device, it might be a container, and we can
+		 * extract a device list from there
+		 */
+		int fd;
+
+		memset(&inf, 0, sizeof(inf));
+		fd = open(devlist->devname, O_RDONLY);
+		if (fd >= 0 &&
+		    md_get_array_info(fd, &inf) == 0 && inf.raid_disks == 0) {
+			/* yep, looks like a container */
+			if (st) {
+				rv = st->ss->load_container(st, fd,
+							    devlist->devname);
+				if (rv == 0)
+					have_container = 1;
+			} else {
+				st = super_by_fd(fd, NULL);
+				if (st && !(rv = st->ss->
+					    load_container(st, fd,
+							   devlist->devname)))
+					have_container = 1;
+				else
+					st = NULL;
+			}
+			if (have_container) {
+				subdevs = s->raiddisks;
+				first_missing = subdevs * 2;
+				second_missing = subdevs * 2;
+				insert_point = subdevs * 2;
+			}
+		}
+		if (fd >= 0)
+			close(fd);
+	}
+	if (st && st->ss->external && s->sparedisks) {
+		pr_err("This metadata type does not support spare disks at create time\n");
+		return 1;
+	}
+	if (subdevs > s->raiddisks+s->sparedisks+s->journaldisks) {
+		pr_err("You have listed more devices (%d) than are in the array(%d)!\n", subdevs, s->raiddisks+s->sparedisks);
+		return 1;
+	}
+	if (!have_container && subdevs < s->raiddisks+s->sparedisks+s->journaldisks) {
+		pr_err("You haven't given enough devices (real or missing) to create this array\n");
+		return 1;
+	}
+	if (s->bitmap_file && s->level <= 0) {
+		pr_err("bitmaps not meaningful with level %s\n",
+			map_num(pers, s->level)?:"given");
+		return 1;
+	}
+
+	/* now set some defaults */
+
+	if (s->layout == UnSet) {
+		do_default_layout = 1;
+		s->layout = default_layout(st, s->level, c->verbose);
+	}
+
+	if (s->level == 10)
+		/* check layout fits in array*/
+		if ((s->layout&255) * ((s->layout>>8)&255) > s->raiddisks) {
+			pr_err("that layout requires at least %d devices\n",
+				(s->layout&255) * ((s->layout>>8)&255));
+			return 1;
+		}
+
+	switch(s->level) {
+	case 4:
+	case 5:
+	case 10:
+	case 6:
+	case 0:
+		if (s->chunk == 0 || s->chunk == UnSet) {
+			s->chunk = UnSet;
+			do_default_chunk = 1;
+			/* chunk will be set later */
+		}
+		break;
+	case LEVEL_LINEAR:
+		/* a chunksize of zero 0s perfectly valid (and preferred) since 2.6.16 */
+		break;
+	case 1:
+	case LEVEL_FAULTY:
+	case LEVEL_MULTIPATH:
+	case LEVEL_CONTAINER:
+		if (s->chunk) {
+			pr_err("specifying chunk size is forbidden for this level\n");
+			return 1;
+		}
+		break;
+	default:
+		pr_err("unknown level %d\n", s->level);
+		return 1;
+	}
+
+	if (s->size == MAX_SIZE)
+		/* use '0' to mean 'max' now... */
+		s->size = 0;
+	if (s->size && s->chunk && s->chunk != UnSet)
+		if (round_size_and_verify(&s->size, s->chunk))
+			return 1;
+
+	newsize = s->size * 2;
+	if (st && ! st->ss->validate_geometry(st, s->level, s->layout, s->raiddisks,
+					      &s->chunk, s->size*2,
+					      s->data_offset, NULL,
+					      &newsize, s->consistency_policy,
+					      c->verbose >= 0))
+		return 1;
+
+	if (s->chunk && s->chunk != UnSet) {
+		newsize &= ~(unsigned long long)(s->chunk*2 - 1);
+		if (do_default_chunk) {
+			/* default chunk was just set */
+			if (c->verbose > 0)
+				pr_err("chunk size defaults to %dK\n", s->chunk);
+			if (round_size_and_verify(&s->size, s->chunk))
+				return 1;
+			do_default_chunk = 0;
+		}
+	}
+
+	if (s->size == 0) {
+		s->size = newsize / 2;
+		if (s->level == 1)
+			/* If this is ever reshaped to RAID5, we will
+			 * need a chunksize.  So round it off a bit
+			 * now just to be safe
+			 */
+			s->size &= ~(64ULL-1);
+
+		if (s->size && c->verbose > 0)
+			pr_err("setting size to %lluK\n", s->size);
+	}
+
+	/* now look at the subdevs */
+	info.array.active_disks = 0;
+	info.array.working_disks = 0;
+	dnum = 0;
+	for (dv = devlist; dv; dv = dv->next)
+		if (s->data_offset == VARIABLE_OFFSET)
+			dv->data_offset = INVALID_SECTORS;
+		else
+			dv->data_offset = s->data_offset;
+
+	for (dv=devlist; dv && !have_container; dv=dv->next, dnum++) {
+		char *dname = dv->devname;
+		unsigned long long freesize;
+		int dfd;
+		char *doff;
+
+		if (strcasecmp(dname, "missing") == 0) {
+			if (first_missing > dnum)
+				first_missing = dnum;
+			if (second_missing > dnum && dnum > first_missing)
+				second_missing = dnum;
+			missing_disks ++;
+			continue;
+		}
+		if (s->data_offset == VARIABLE_OFFSET) {
+			doff = strchr(dname, ':');
+			if (doff) {
+				*doff++ = 0;
+				dv->data_offset = parse_size(doff);
+			} else
+				dv->data_offset = INVALID_SECTORS;
+		} else
+			dv->data_offset = s->data_offset;
+
+		dfd = open(dname, O_RDONLY);
+		if (dfd < 0) {
+			pr_err("cannot open %s: %s\n",
+				dname, strerror(errno));
+			exit(2);
+		}
+		if (!fstat_is_blkdev(dfd, dname, NULL)) {
+			close(dfd);
+			exit(2);
+		}
+		close(dfd);
+		info.array.working_disks++;
+		if (dnum < s->raiddisks && dv->disposition != 'j')
+			info.array.active_disks++;
+		if (st == NULL) {
+			struct createinfo *ci = conf_get_create_info();
+			if (ci)
+				st = ci->supertype;
+		}
+		if (st == NULL) {
+			/* Need to choose a default metadata, which is different
+			 * depending on geometry of array.
+			 */
+			int i;
+			char *name = "default";
+			for(i = 0; !st && superlist[i]; i++) {
+				st = superlist[i]->match_metadata_desc(name);
+				if (!st)
+					continue;
+				if (do_default_layout)
+					s->layout = default_layout(st, s->level, c->verbose);
+				switch (st->ss->validate_geometry(
+						st, s->level, s->layout, s->raiddisks,
+						&s->chunk, s->size*2,
+						dv->data_offset, dname,
+						&freesize, s->consistency_policy,
+						c->verbose > 0)) {
+				case -1: /* Not valid, message printed, and not
+					  * worth checking any further */
+					exit(2);
+					break;
+				case 0: /* Geometry not valid */
+					free(st);
+					st = NULL;
+					s->chunk = do_default_chunk ? UnSet : s->chunk;
+					break;
+				case 1:	/* All happy */
+					break;
+				}
+			}
+
+			if (!st) {
+				int dfd = open(dname, O_RDONLY|O_EXCL);
+				if (dfd < 0) {
+					pr_err("cannot open %s: %s\n",
+						dname, strerror(errno));
+					exit(2);
+				}
+				pr_err("device %s not suitable for any style of array\n",
+					dname);
+				exit(2);
+			}
+			if (st->ss != &super0 ||
+			    st->minor_version != 90)
+				did_default = 1;
+		} else {
+			if (do_default_layout)
+				s->layout = default_layout(st, s->level, 0);
+			if (!st->ss->validate_geometry(st, s->level, s->layout,
+						       s->raiddisks,
+						       &s->chunk, s->size*2,
+						       dv->data_offset,
+						       dname, &freesize,
+						       s->consistency_policy,
+						       c->verbose >= 0)) {
+
+				pr_err("%s is not suitable for this array.\n",
+				       dname);
+				fail = 1;
+				continue;
+			}
+		}
+
+		if (dv->disposition == 'j')
+			goto skip_size_check;  /* skip write journal for size check */
+
+		freesize /= 2; /* convert to K */
+		if (s->chunk && s->chunk != UnSet) {
+			/* round to chunk size */
+			freesize = freesize & ~(s->chunk-1);
+			if (do_default_chunk) {
+				/* default chunk was just set */
+				if (c->verbose > 0)
+					pr_err("chunk size defaults to %dK\n", s->chunk);
+				if (round_size_and_verify(&s->size, s->chunk))
+					return 1;
+				do_default_chunk = 0;
+			}
+		}
+		if (!freesize) {
+			pr_err("no free space left on %s\n", dname);
+			fail = 1;
+			continue;
+		}
+
+		if (s->size && freesize < s->size) {
+			pr_err("%s is smaller than given size. %lluK < %lluK + metadata\n",
+				dname, freesize, s->size);
+			fail = 1;
+			continue;
+		}
+		if (maxdisc == NULL || (maxdisc && freesize > maxsize)) {
+			maxdisc = dname;
+			maxsize = freesize;
+		}
+		if (mindisc ==NULL || (mindisc && freesize < minsize)) {
+			mindisc = dname;
+			minsize = freesize;
+		}
+	skip_size_check:
+		if (c->runstop != 1 || c->verbose >= 0) {
+			int fd = open(dname, O_RDONLY);
+			if (fd < 0) {
+				pr_err("Cannot open %s: %s\n",
+					dname, strerror(errno));
+				fail = 1;
+				continue;
+			}
+			warn |= check_ext2(fd, dname);
+			warn |= check_reiser(fd, dname);
+			warn |= check_raid(fd, dname);
+			if (strcmp(st->ss->name, "1.x") == 0 &&
+			    st->minor_version >= 1)
+				/* metadata at front */
+				warn |= check_partitions(fd, dname, 0, 0);
+			else if (s->level == 1 || is_container(s->level) ||
+				 (s->level == 0 && s->raiddisks == 1))
+				/* partitions could be meaningful */
+				warn |= check_partitions(fd, dname, freesize*2, s->size*2);
+			else
+				/* partitions cannot be meaningful */
+				warn |= check_partitions(fd, dname, 0, 0);
+			if (strcmp(st->ss->name, "1.x") == 0 &&
+			    st->minor_version >= 1 &&
+			    did_default &&
+			    s->level == 1 &&
+			    (warn & 1024) == 0) {
+				warn |= 1024;
+				pr_err("Note: this array has metadata at the start and\n"
+					"    may not be suitable as a boot device.  If you plan to\n"
+					"    store '/boot' on this device please ensure that\n"
+					"    your boot-loader understands md/v1.x metadata, or use\n"
+					"    --metadata=0.90\n");
+			}
+			close(fd);
+		}
+	}
+	if (missing_disks == dnum && !have_container) {
+		pr_err("Subdevs can't be all missing\n");
+		return 1;
+	}
+	if (s->raiddisks + s->sparedisks > st->max_devs) {
+		pr_err("Too many devices: %s metadata only supports %d\n",
+			st->ss->name, st->max_devs);
+		return 1;
+	}
+	if (have_container)
+		info.array.working_disks = s->raiddisks;
+	if (fail) {
+		pr_err("create aborted\n");
+		return 1;
+	}
+	if (s->size == 0) {
+		if (mindisc == NULL && !have_container) {
+			pr_err("no size and no drives given - aborting create.\n");
+			return 1;
+		}
+		if (s->level > 0 || s->level == LEVEL_MULTIPATH ||
+		    s->level == LEVEL_FAULTY || st->ss->external) {
+			/* size is meaningful */
+			if (!st->ss->validate_geometry(st, s->level, s->layout,
+						       s->raiddisks,
+						       &s->chunk, minsize*2,
+						       s->data_offset,
+						       NULL, NULL,
+						       s->consistency_policy, 0)) {
+				pr_err("devices too large for RAID level %d\n", s->level);
+				return 1;
+			}
+			s->size = minsize;
+			if (s->level == 1)
+				/* If this is ever reshaped to RAID5, we will
+				 * need a chunksize.  So round it off a bit
+				 * now just to be safe
+				 */
+				s->size &= ~(64ULL-1);
+			if (c->verbose > 0)
+				pr_err("size set to %lluK\n", s->size);
+		}
+	}
+
+	if (!s->bitmap_file &&
+	    !st->ss->external &&
+	    s->level >= 1 &&
+	    st->ss->add_internal_bitmap &&
+	    s->journaldisks == 0 &&
+	    (s->consistency_policy != CONSISTENCY_POLICY_RESYNC &&
+	     s->consistency_policy != CONSISTENCY_POLICY_PPL) &&
+	    (s->write_behind || s->size > 100*1024*1024ULL)) {
+		if (c->verbose > 0)
+			pr_err("automatically enabling write-intent bitmap on large array\n");
+		s->bitmap_file = "internal";
+	}
+	if (s->bitmap_file && str_is_none(s->bitmap_file) == true)
+		s->bitmap_file = NULL;
+
+	if (s->consistency_policy == CONSISTENCY_POLICY_PPL &&
+	    !st->ss->write_init_ppl) {
+		pr_err("%s metadata does not support PPL\n", st->ss->name);
+		return 1;
+	}
+
+	if (!have_container && s->level > 0 && ((maxsize-s->size)*100 > maxsize)) {
+		if (c->runstop != 1 || c->verbose >= 0)
+			pr_err("largest drive (%s) exceeds size (%lluK) by more than 1%%\n",
+				maxdisc, s->size);
+		warn = 1;
+	}
+
+	if (st->ss->detail_platform && st->ss->detail_platform(0, 1, NULL) != 0) {
+		if (c->runstop != 1 || c->verbose >= 0)
+			pr_err("%s unable to enumerate platform support\n"
+				"    array may not be compatible with hardware/firmware\n",
+				st->ss->name);
+		warn = 1;
+	}
+	st->nodes = c->nodes;
+	st->cluster_name = c->homecluster;
+
+	if (warn) {
+		if (c->runstop!= 1) {
+			if (!ask("Continue creating array? ")) {
+				pr_err("create aborted.\n");
+				return 1;
+			}
+		} else {
+			if (c->verbose > 0)
+				pr_err("creation continuing despite oddities due to --run\n");
+		}
+	}
+
+	/* If this is raid4/5, we want to configure the last active slot
+	 * as missing, so that a reconstruct happens (faster than re-parity)
+	 * FIX: Can we do this for raid6 as well?
+	 */
+	if (st->ss->external == 0 && s->assume_clean == 0 &&
+	    c->force == 0 && first_missing >= s->raiddisks) {
+		switch (s->level) {
+		case 4:
+		case 5:
+			insert_point = s->raiddisks-1;
+			s->sparedisks++;
+			info.array.active_disks--;
+			missing_disks++;
+			break;
+		default:
+			break;
+		}
+	}
+	/* For raid6, if creating with 1 missing drive, make a good drive
+	 * into a spare, else the create will fail
+	 */
+	if (s->assume_clean == 0 && c->force == 0 && first_missing < s->raiddisks &&
+	    st->ss->external == 0 &&
+	    second_missing >= s->raiddisks && s->level == 6) {
+		insert_point = s->raiddisks - 1;
+		if (insert_point == first_missing)
+			insert_point--;
+		s->sparedisks ++;
+		info.array.active_disks--;
+		missing_disks++;
+	}
+
+	if (s->level <= 0 && first_missing < subdevs * 2) {
+		pr_err("This level does not support missing devices\n");
+		return 1;
+	}
+
+	/* We need to create the device */
+	map_lock(&map);
+	mdfd = create_mddev(ident->devname, ident->name, c->autof, LOCAL, chosen_name, 1);
+	if (mdfd < 0) {
+		map_unlock(&map);
+		return 1;
+	}
+	/* verify if chosen_name is not in use,
+	 * it could be in conflict with already existing device
+	 * e.g. container, array
+	 */
+	if (strncmp(chosen_name, DEV_MD_DIR, DEV_MD_DIR_LEN) == 0 &&
+	    map_by_name(&map, chosen_name + DEV_MD_DIR_LEN)) {
+		pr_err("Array name %s is in use already.\n", chosen_name);
+		close(mdfd);
+		map_unlock(&map);
+		udev_unblock();
+		return 1;
+	}
+
+	memset(&inf, 0, sizeof(inf));
+	md_get_array_info(mdfd, &inf);
+	if (inf.working_disks != 0) {
+		pr_err("another array by this name is already running.\n");
+		goto abort_locked;
+	}
+
+	/* Ok, lets try some ioctls */
+
+	info.array.level = s->level;
+	info.array.size = s->size;
+	info.array.raid_disks = s->raiddisks;
+	/* The kernel should *know* what md_minor we are dealing
+	 * with, but it chooses to trust me instead. Sigh
+	 */
+	info.array.md_minor = 0;
+	if (fstat_is_blkdev(mdfd, chosen_name, &rdev))
+		info.array.md_minor = minor(rdev);
+	info.array.not_persistent = 0;
+
+	if (((s->level == 4 || s->level == 5) &&
+	     (insert_point < s->raiddisks || first_missing < s->raiddisks)) ||
+	    (s->level == 6 && (insert_point < s->raiddisks ||
+			       second_missing < s->raiddisks)) ||
+	    (s->level <= 0) || s->assume_clean) {
+		info.array.state = 1; /* clean, but one+ drive will be missing*/
+		info.resync_start = MaxSector;
+	} else {
+		info.array.state = 0; /* not clean, but no errors */
+		info.resync_start = 0;
+	}
+	if (s->level == 10) {
+		/* for raid10, the bitmap size is the capacity of the array,
+		 * which is array.size * raid_disks / ncopies;
+		 * .. but convert to sectors.
+		 */
+		int ncopies = ((s->layout>>8) & 255) * (s->layout & 255);
+		bitmapsize = s->size * s->raiddisks / ncopies * 2;
+/*		printf("bms=%llu as=%d rd=%d nc=%d\n", bitmapsize, s->size, s->raiddisks, ncopies);*/
+	} else
+		bitmapsize = s->size * 2;
+
+	/* There is lots of redundancy in these disk counts,
+	 * raid_disks is the most meaningful value
+	 *          it describes the geometry of the array
+	 *          it is constant
+	 * nr_disks is total number of used slots.
+	 *          it should be raid_disks+spare_disks
+	 * spare_disks is the number of extra disks present
+	 *          see above
+	 * active_disks is the number of working disks in
+	 *          active slots. (With raid_disks)
+	 * working_disks is the total number of working disks,
+	 *          including spares
+	 * failed_disks is the number of disks marked failed
+	 *
+	 * Ideally, the kernel would keep these (except raid_disks)
+	 * up-to-date as we ADD_NEW_DISK, but it doesn't (yet).
+	 * So for now, we assume that all raid and spare
+	 * devices will be given.
+	 */
+	info.array.spare_disks=s->sparedisks;
+	info.array.failed_disks=missing_disks;
+	info.array.nr_disks = info.array.working_disks
+		+ info.array.failed_disks;
+	info.array.layout = s->layout;
+	info.array.chunk_size = s->chunk*1024;
+
+	if (*name == 0) {
+		/* base name on devname */
+		/*  /dev/md0 -> 0
+		 *  /dev/md_d0 -> d0
+		 *  /dev/md_foo -> foo
+		 *  /dev/md/1 -> 1
+		 *  /dev/md/d1 -> d1
+		 *  /dev/md/home -> home
+		 *  /dev/mdhome -> home
+		 */
+		/* FIXME compare this with rules in create_mddev */
+		name = strrchr(chosen_name, '/');
+
+		if (name) {
+			name++;
+			if (strncmp(name, "md_", 3) == 0 &&
+			    strlen(name) > 3 && (name - chosen_name) == 5 /* /dev/ */)
+				name += 3;
+			else if (strncmp(name, "md", 2) == 0 &&
+				 strlen(name) > 2 && isdigit(name[2]) &&
+				 (name - chosen_name) == 5 /* /dev/ */)
+				name += 2;
+		}
+	}
+	if (!st->ss->init_super(st, &info.array, s, name, c->homehost, uuid,
+				s->data_offset))
+		goto abort_locked;
+
+	total_slots = info.array.nr_disks;
+	st->ss->getinfo_super(st, &info, NULL);
+	if (sysfs_init(&info, mdfd, NULL)) {
+		pr_err("unable to initialize sysfs\n");
+		goto abort_locked;
+	}
+
+	if (did_default && c->verbose >= 0) {
+		if (is_subarray(info.text_version)) {
+			char devnm[32];
+			char *ep;
+			struct mdinfo *mdi;
+
+			strncpy(devnm, info.text_version+1, 32);
+			devnm[31] = 0;
+			ep = strchr(devnm, '/');
+			if (ep)
+				*ep = 0;
+
+			mdi = sysfs_read(-1, devnm, GET_VERSION);
+
+			pr_info("Creating array inside %s container %s\n",
+				mdi?mdi->text_version:"managed", devnm);
+			sysfs_free(mdi);
+		} else
+			pr_info("Defaulting to version %s metadata\n",
+				info.text_version);
+	}
+
+	map_update(&map, fd2devnm(mdfd), info.text_version,
+		   info.uuid, chosen_name);
+	/* Keep map locked until devices have been added to array
+	 * to stop another mdadm from finding and using those devices.
+	 */
+
+	if (s->bitmap_file && (strcmp(s->bitmap_file, "internal") == 0 ||
+			       strcmp(s->bitmap_file, "clustered") == 0)) {
+		if (!st->ss->add_internal_bitmap) {
+			pr_err("internal bitmaps not supported with %s metadata\n",
+				st->ss->name);
+			goto abort_locked;
+		}
+		if (st->ss->add_internal_bitmap(st, &s->bitmap_chunk,
+						c->delay, s->write_behind,
+						bitmapsize, 1, major_num)) {
+			pr_err("Given bitmap chunk size not supported.\n");
+			goto abort_locked;
+		}
+		s->bitmap_file = NULL;
+	}
+
+	if (sysfs_init(&info, mdfd, NULL)) {
+		pr_err("unable to initialize sysfs\n");
+		goto abort_locked;
+	}
+
+	if (st->ss->external && st->container_devnm[0]) {
+		/* member */
+
+		/* When creating a member, we need to be careful
+		 * to negotiate with mdmon properly.
+		 * If it is already running, we cannot write to
+		 * the devices and must ask it to do that part.
+		 * If it isn't running, we write to the devices,
+		 * and then start it.
+		 * We hold an exclusive open on the container
+		 * device to make sure mdmon doesn't exit after
+		 * we checked that it is running.
+		 *
+		 * For now, fail if it is already running.
+		 */
+		container_fd = open_dev_excl(st->container_devnm);
+		if (container_fd < 0) {
+			pr_err("Cannot get exclusive open on container - weird.\n");
+			goto abort_locked;
+		}
+		if (mdmon_running(st->container_devnm)) {
+			if (c->verbose)
+				pr_err("reusing mdmon for %s.\n",
+					st->container_devnm);
+			st->update_tail = &st->updates;
+		} else
+			need_mdmon = 1;
+	}
+	rv = set_array_info(mdfd, st, &info);
+	if (rv) {
+		pr_err("failed to set array info for %s: %s\n", chosen_name, strerror(errno));
+		goto abort_locked;
+	}
+
+	if (s->bitmap_file) {
+		int uuid[4];
+
+		st->ss->uuid_from_super(st, uuid);
+		if (CreateBitmap(s->bitmap_file, c->force, (char*)uuid, s->bitmap_chunk,
+				 c->delay, s->write_behind,
+				 bitmapsize,
+				 major_num)) {
+			goto abort_locked;
+		}
+		bitmap_fd = open(s->bitmap_file, O_RDWR);
+		if (bitmap_fd < 0) {
+			pr_err("weird: %s cannot be opened\n",
+				s->bitmap_file);
+			goto abort_locked;
+		}
+		if (ioctl(mdfd, SET_BITMAP_FILE, bitmap_fd) < 0) {
+			pr_err("Cannot set bitmap file for %s: %s\n", chosen_name, strerror(errno));
+			goto abort_locked;
+		}
+	}
+
+	if (add_disks(mdfd, &info, s, c, st, &map, devlist, total_slots,
+		      have_container, insert_point, major_num, chosen_name))
+		goto abort_locked;
+
+	map_unlock(&map);
+
+	if (is_container(s->level)) {
+		/* No need to start.  But we should signal udev to
+		 * create links */
+		sysfs_uevent(&info, "change");
+		if (c->verbose >= 0)
+			pr_err("container %s prepared.\n", chosen_name);
+		wait_for(chosen_name, mdfd);
+	} else if (c->runstop == 1 || subdevs >= s->raiddisks) {
+		if (st->ss->external) {
+			int err;
+			switch(s->level) {
+			case LEVEL_LINEAR:
+			case LEVEL_MULTIPATH:
+			case 0:
+				err = sysfs_set_str(&info, NULL, "array_state",
+						    c->readonly
+						    ? "readonly"
+						    : "active");
+				need_mdmon = 0;
+				break;
+			default:
+				err = sysfs_set_str(&info, NULL, "array_state",
+						    "readonly");
+				break;
+			}
+			sysfs_set_safemode(&info, info.safe_mode_delay);
+			if (err) {
+				pr_err("failed to activate array.\n");
+				ioctl(mdfd, STOP_ARRAY, NULL);
+				goto abort;
+			}
+		} else if (c->readonly &&
+			   sysfs_attribute_available(
+				   &info, NULL, "array_state")) {
+			if (sysfs_set_str(&info, NULL,
+					  "array_state", "readonly") < 0) {
+				pr_err("Failed to start array: %s\n",
+				       strerror(errno));
+				ioctl(mdfd, STOP_ARRAY, NULL);
+				goto abort;
+			}
+		} else {
+			/* param is not actually used */
+			mdu_param_t param;
+			if (ioctl(mdfd, RUN_ARRAY, &param)) {
+				pr_err("RUN_ARRAY failed: %s\n",
+				       strerror(errno));
+				if (errno == 524 /* ENOTSUP */ &&
+				    info.array.level == 0)
+					cont_err("Please use --layout=original or --layout=alternate\n");
+				if (info.array.chunk_size & (info.array.chunk_size-1)) {
+					cont_err("Problem may be that chunk size is not a power of 2\n");
+				}
+				ioctl(mdfd, STOP_ARRAY, NULL);
+				goto abort;
+			}
+			/* if start_ro module parameter is set, array is
+			 * auto-read-only, which is bad as the resync won't
+			 * start.  So lets make it read-write now.
+			 */
+			ioctl(mdfd, RESTART_ARRAY_RW, NULL);
+		}
+		if (c->verbose >= 0)
+			pr_info("array %s started.\n", chosen_name);
+		if (st->ss->external && st->container_devnm[0]) {
+			if (need_mdmon)
+				start_mdmon(st->container_devnm);
+
+			ping_monitor(st->container_devnm);
+			close(container_fd);
+		}
+		wait_for(chosen_name, mdfd);
+	} else {
+		pr_err("not starting array - not enough devices.\n");
+	}
+	udev_unblock();
+	close(mdfd);
+	sysfs_uevent(&info, "change");
+	return 0;
+
+ abort:
+	udev_unblock();
+	map_lock(&map);
+ abort_locked:
+	map_remove(&map, fd2devnm(mdfd));
+	map_unlock(&map);
+
+	if (mdfd >= 0)
+		close(mdfd);
+	return 1;
+}