Correct checking if file descriptors are valid

[thirdparty/mdadm.git] / Assemble.c

/*
 * mdadm - manage Linux "md" devices aka RAID arrays.
 *
 * Copyright (C) 2001-2016 Neil Brown <neilb@suse.com>
 *
 *
 *    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        <ctype.h>

mapping_t assemble_statuses[] = {
        { "but cannot be started", INCR_NO },
        { "but not safe to start", INCR_UNSAFE },
        { "and started", INCR_YES },
        { NULL, INCR_ALREADY }
};


/**
 * struct assembly_array_info - General, meaningful information for assembly.
 * @name: Array name.
 * @new_cnt: Count of drives known to be members, recently added.
 * @preexist_cnt: Count of member drives in pre-assembled array.
 * @exp_cnt: Count of known expansion targets.
 *
 * FIXME: @exp_new_cnt for recently added expansion targets.
 */
struct assembly_array_info {
        char *name;
        int new_cnt;
        int preexist_cnt;
        int exp_cnt;
};

/**
 * set_array_assembly_status() - generate status of assembly for an array.
 * @c: Global settings.
 * @result: Pointer to status mask.
 * @status: Status to be set/printed.
 * @arr: Array information.
 *
 *  Print status message to user or set it in @result if it is not NULL.
 */
static void set_array_assembly_status(struct context *c,
                                   int *result, int status,
                                   struct assembly_array_info *arr)
{
        int raid_disks = arr->preexist_cnt + arr->new_cnt;
        char *status_msg = map_num(assemble_statuses, status);

        if (c->export && result)
                *result |= status;

        if (c->export || c->verbose < 0)
                return;

        pr_err("%s has been assembled with %d device%s", arr->name,
               raid_disks, raid_disks == 1 ? "":"s");
        if (arr->preexist_cnt > 0)
                fprintf(stderr, " (%d new)", arr->new_cnt);
        if (arr->exp_cnt)
                fprintf(stderr, " ( + %d for expansion)", arr->exp_cnt);
        if (status_msg)
                fprintf(stderr, " %s", status_msg);
        fprintf(stderr, ".\n");
}

static int name_matches(char *found, char *required, char *homehost, int require_homehost)
{
        /* See if the name found matches the required name, possibly
         * prefixed with 'homehost'
         */
        char *sep;
        unsigned int l;

        if (strcmp(found, required)==0)
                return 1;
        sep = strchr(found, ':');
        if (!sep)
                return 0;
        l = sep - found;
        if (strncmp(found, "any:", 4) == 0 ||
            (homehost && strcmp(homehost, "any") == 0) ||
            !require_homehost ||
            (homehost && strlen(homehost) == l &&
             strncmp(found, homehost, l) == 0)) {
                /* matching homehost */
                if (strcmp(sep+1, required) == 0)
                        return 1;
        }
        return 0;
}

static int is_member_busy(char *metadata_version)
{
        /* check if the given member array is active */
        struct mdstat_ent *mdstat = mdstat_read(0, 0);
        struct mdstat_ent *ent;
        int busy = 0;

        for (ent = mdstat; ent; ent = ent->next) {
                if (ent->metadata_version == NULL)
                        continue;
                if (strncmp(ent->metadata_version, "external:", 9) != 0)
                        continue;
                if (!is_subarray(&ent->metadata_version[9]))
                        continue;
                /* Skip first char - it can be '/' or '-' */
                if (strcmp(&ent->metadata_version[10], metadata_version+1) == 0) {
                        busy = 1;
                        break;
                }
        }
        free_mdstat(mdstat);

        return busy;
}

static int ident_matches(struct mddev_ident *ident,
                         struct mdinfo *content,
                         struct supertype *tst,
                         char *homehost, int require_homehost,
                         char *update, char *devname)
{

        if (ident->uuid_set && (!update || strcmp(update, "uuid")!= 0) &&
            same_uuid(content->uuid, ident->uuid, tst->ss->swapuuid)==0 &&
            memcmp(content->uuid, uuid_zero, sizeof(int[4])) != 0) {
                if (devname)
                        pr_err("%s has wrong uuid.\n", devname);
                return 0;
        }
        if (ident->name[0] && (!update || strcmp(update, "name")!= 0) &&
            name_matches(content->name, ident->name, homehost, require_homehost)==0) {
                if (devname)
                        pr_err("%s has wrong name.\n", devname);
                return 0;
        }
        if (ident->super_minor != UnSet &&
            ident->super_minor != content->array.md_minor) {
                if (devname)
                        pr_err("%s has wrong super-minor.\n",
                               devname);
                return 0;
        }
        if (ident->level != UnSet &&
            ident->level != content->array.level) {
                if (devname)
                        pr_err("%s has wrong raid level.\n",
                               devname);
                return 0;
        }
        if (ident->raid_disks != UnSet &&
            content->array.raid_disks != 0 && /* metadata doesn't know how many to expect */
            ident->raid_disks!= content->array.raid_disks) {
                if (devname)
                        pr_err("%s requires wrong number of drives.\n",
                               devname);
                return 0;
        }
        if (ident->member && ident->member[0]) {
                /* content->text_version must match */
                char *s = strchr(content->text_version+1, '/');
                if (s == NULL) {
                        if (devname)
                                pr_err("%s is not a container and one is required.\n",
                                       devname);
                        return 0;
                } else if (strcmp(ident->member, s+1) != 0) {
                        if (devname)
                                pr_err("skipping wrong member %s is %s\n",
                                       content->text_version, devname);
                        return 0;
                }
        }
        return 1;
}

static int select_devices(struct mddev_dev *devlist,
                          struct mddev_ident *ident,
                          struct supertype **stp,
                          struct mdinfo **contentp,
                          struct context *c,
                          int inargv, int auto_assem)
{
        struct mddev_dev *tmpdev;
        int num_devs;
        struct supertype *st = *stp;
        struct mdinfo *content = NULL;
        int report_mismatch = ((inargv && c->verbose >= 0) || c->verbose > 0);
        struct domainlist *domains = NULL;
        dev_t rdev;

        tmpdev = devlist; num_devs = 0;
        while (tmpdev) {
                if (tmpdev->used)
                        tmpdev->used = 2;
                else
                        num_devs++;
                tmpdev->disposition = 0;
                tmpdev = tmpdev->next;
        }

        /* first walk the list of devices to find a consistent set
         * that match the criterea, if that is possible.
         * We flag the ones we like with 'used'.
         */
        for (tmpdev = devlist;
             tmpdev;
             tmpdev = tmpdev ? tmpdev->next : NULL) {
                char *devname = tmpdev->devname;
                int dfd;
                struct supertype *tst;
                struct dev_policy *pol = NULL;
                int found_container = 0;

                if (tmpdev->used > 1)
                        continue;

                if (ident->container) {
                        if (ident->container[0] == '/' &&
                            !same_dev(ident->container, devname)) {
                                if (report_mismatch)
                                        pr_err("%s is not the container required (%s)\n",
                                               devname, ident->container);
                                continue;
                        }
                } else if (ident->devices &&
                           !match_oneof(ident->devices, devname)) {
                        /* Note that we ignore the "device=" identifier if a
                         * "container=" is given.  Checking both is unnecessarily
                         * complicated.
                         */
                        if (report_mismatch)
                                pr_err("%s is not one of %s\n", devname, ident->devices);
                        continue;
                }

                tst = dup_super(st);

                dfd = dev_open(devname, O_RDONLY);
                if (dfd < 0) {
                        if (report_mismatch)
                                pr_err("cannot open device %s: %s\n",
                                       devname, strerror(errno));
                        tmpdev->used = 2;
                } else if (!fstat_is_blkdev(dfd, devname, &rdev)) {
                        tmpdev->used = 2;
                } else if (must_be_container(dfd)) {
                        if (st) {
                                /* already found some components, this cannot
                                 * be another one.
                                 */
                                if (report_mismatch)
                                        pr_err("%s is a container, but we are looking for components\n",
                                               devname);
                                tmpdev->used = 2;
                        } if (!tst && (tst = super_by_fd(dfd, NULL)) == NULL) {
                                if (report_mismatch)
                                        pr_err("not a recognisable container: %s\n",
                                               devname);
                                tmpdev->used = 2;
                        } else if (!tst->ss->load_container ||
                                   tst->ss->load_container(tst, dfd, NULL)) {
                                if (report_mismatch)
                                        pr_err("no correct container type: %s\n",
                                               devname);
                                tmpdev->used = 2;
                        } else if (auto_assem &&
                                   !conf_test_metadata(tst->ss->name,
                                                       (pol = devid_policy(rdev)),
                                                       tst->ss->match_home(tst, c->homehost) == 1)) {
                                if (report_mismatch)
                                        pr_err("%s has metadata type %s for which auto-assembly is disabled\n",
                                               devname, tst->ss->name);
                                tmpdev->used = 2;
                        } else
                                found_container = 1;
                } else {
                        if (!tst && (tst = guess_super(dfd)) == NULL) {
                                if (report_mismatch)
                                        pr_err("no recogniseable superblock on %s\n",
                                               devname);
                                tmpdev->used = 2;
                        } else if ((tst->ignore_hw_compat = 0),
                                   tst->ss->load_super(tst, dfd,
                                                       report_mismatch ? devname : NULL)) {
                                if (report_mismatch)
                                        pr_err("no RAID superblock on %s\n",
                                               devname);
                                tmpdev->used = 2;
                        } else if (tst->ss->compare_super == NULL) {
                                if (report_mismatch)
                                        pr_err("Cannot assemble %s metadata on %s\n",
                                               tst->ss->name, devname);
                                tmpdev->used = 2;
                        } else if (auto_assem && st == NULL &&
                                   !conf_test_metadata(tst->ss->name,
                                                       (pol = devid_policy(rdev)),
                                                       tst->ss->match_home(tst, c->homehost) == 1)) {
                                if (report_mismatch)
                                        pr_err("%s has metadata type %s for which auto-assembly is disabled\n",
                                               devname, tst->ss->name);
                                tmpdev->used = 2;
                        }
                }
                if (dfd >= 0) close(dfd);
                if (tmpdev->used == 2) {
                        if (auto_assem || !inargv)
                                /* Ignore unrecognised devices during auto-assembly */
                                goto loop;
                        if (ident->name[0] ||
                            ident->super_minor != UnSet)
                                /* Ignore unrecognised device if looking for
                                 * specific array */
                                goto loop;
                        if (ident->uuid_set)
                                /* ignore unrecognized device if looking for
                                 * specific uuid
                                 */
                                goto loop;

                        pr_err("%s has no superblock - assembly aborted\n",
                               devname);
                        if (st)
                                st->ss->free_super(st);
                        dev_policy_free(pol);
                        domain_free(domains);
                        if (tst)
                                tst->ss->free_super(tst);
                        return -1;
                }

                if (found_container) {
                        /* tmpdev is a container.  We need to be either
                         * looking for a member, or auto-assembling
                         */
                        /* should be safe to try an exclusive open now, we
                         * have rejected anything that some other mdadm might
                         * be looking at
                         */
                        dfd = dev_open(devname, O_RDONLY | O_EXCL);
                        if (dfd < 0) {
                                if (report_mismatch)
                                        pr_err("%s is busy - skipping\n", devname);
                                goto loop;
                        }
                        close(dfd);

                        if (ident->container && ident->container[0] != '/') {
                                /* we have a uuid */
                                int uuid[4];

                                content = *contentp;
                                tst->ss->getinfo_super(tst, content, NULL);

                                if (!parse_uuid(ident->container, uuid) ||
                                    !same_uuid(content->uuid, uuid, tst->ss->swapuuid)) {
                                        if (report_mismatch)
                                                pr_err("%s has wrong UUID to be required container\n",
                                                       devname);
                                        goto loop;
                                }
                        }
                        /* It is worth looking inside this container.
                         */
                        if (c->verbose > 0)
                                pr_err("looking in container %s\n",
                                       devname);

                        for (content = tst->ss->container_content(tst, NULL);
                             content;
                             content = content->next) {

                                if (!ident_matches(ident, content, tst,
                                                   c->homehost, c->require_homehost,
                                                   c->update,
                                                   report_mismatch ? devname : NULL))
                                        /* message already printed */;
                                else if (is_member_busy(content->text_version)) {
                                        if (report_mismatch)
                                                pr_err("member %s in %s is already assembled\n",
                                                       content->text_version,
                                                       devname);
                                } else if (content->array.state & (1<<MD_SB_BLOCK_VOLUME)) {
                                        /* do not assemble arrays with unsupported configurations */
                                        pr_err("Cannot activate member %s in %s.\n",
                                               content->text_version,
                                               devname);
                                } else
                                        break;
                        }
                        if (!content) {
                                tmpdev->used = 2;
                                goto loop; /* empty container */
                        }

                        st = tst; tst = NULL;
                        if (!auto_assem && inargv && tmpdev->next != NULL) {
                                pr_err("%s is a container, but is not only device given: confused and aborting\n",
                                       devname);
                                st->ss->free_super(st);
                                dev_policy_free(pol);
                                domain_free(domains);
                                return -1;
                        }
                        if (c->verbose > 0)
                                pr_err("found match on member %s in %s\n",
                                       content->text_version, devname);

                        /* make sure we finished the loop */
                        tmpdev = NULL;
                        goto loop;
                } else {
                        content = *contentp;
                        tst->ss->getinfo_super(tst, content, NULL);

                        if (!ident_matches(ident, content, tst,
                                           c->homehost, c->require_homehost,
                                           c->update,
                                           report_mismatch ? devname : NULL))
                                goto loop;

                        if (auto_assem) {
                                /* Never auto-assemble things that conflict
                                 * with mdadm.conf in some way
                                 */
                                struct mddev_ident *match;
                                int rv = 0;

                                match = conf_match(tst, content, devname,
                                                   report_mismatch ? c->verbose : -1,
                                                   &rv);
                                if (!match && rv == 2)
                                        goto loop;
                                if (match && match->devname &&
                                    strcasecmp(match->devname, "<ignore>") == 0) {
                                        if (report_mismatch)
                                                pr_err("%s is a member of an explicitly ignored array\n",
                                                       devname);
                                        goto loop;
                                }
                                if (match && !ident_matches(match, content, tst,
                                                            c->homehost, c->require_homehost,
                                                            c->update,
                                                            report_mismatch ? devname : NULL))
                                        /* Array exists  in mdadm.conf but some
                                         * details don't match, so reject it
                                         */
                                        goto loop;
                        }

                        /* should be safe to try an exclusive open now, we
                         * have rejected anything that some other mdadm might
                         * be looking at
                         */
                        dfd = dev_open(devname, O_RDONLY | O_EXCL);
                        if (dfd < 0) {
                                if (report_mismatch)
                                        pr_err("%s is busy - skipping\n", devname);
                                goto loop;
                        }
                        close(dfd);

                        if (st == NULL)
                                st = dup_super(tst);
                        if (st->minor_version == -1)
                                st->minor_version = tst->minor_version;

                        if (memcmp(content->uuid, uuid_zero,
                                   sizeof(int[4])) == 0) {
                                /* this is a floating spare.  It cannot define
                                 * an array unless there are no more arrays of
                                 * this type to be found.  It can be included
                                 * in an array of this type though.
                                 */
                                tmpdev->used = 3;
                                goto loop;
                        }

                        if (st->ss != tst->ss ||
                            st->minor_version != tst->minor_version ||
                            st->ss->compare_super(st, tst, 1) != 0) {
                                /* Some mismatch. If exactly one array matches this host,
                                 * we can resolve on that one.
                                 * Or, if we are auto assembling, we just ignore the second
                                 * for now.
                                 */
                                if (auto_assem)
                                        goto loop;
                                if (c->homehost) {
                                        int first = st->ss->match_home(st, c->homehost);
                                        int last = tst->ss->match_home(tst, c->homehost);
                                        if (first != last &&
                                            (first == 1 || last == 1)) {
                                                /* We can do something */
                                                if (first) {/* just ignore this one */
                                                        if (report_mismatch)
                                                                pr_err("%s misses out due to wrong homehost\n",
                                                                       devname);
                                                        goto loop;
                                                } else { /* reject all those sofar */
                                                        struct mddev_dev *td;
                                                        if (report_mismatch)
                                                                pr_err("%s overrides previous devices due to good homehost\n",
                                                                       devname);
                                                        for (td=devlist; td != tmpdev; td=td->next)
                                                                if (td->used == 1)
                                                                        td->used = 0;
                                                        tmpdev->used = 1;
                                                        goto loop;
                                                }
                                        }
                                }
                                pr_err("superblock on %s doesn't match others - assembly aborted\n",
                                       devname);
                                tst->ss->free_super(tst);
                                st->ss->free_super(st);
                                dev_policy_free(pol);
                                domain_free(domains);
                                return -1;
                        }
                        tmpdev->used = 1;
                }
        loop:
                /* Collect domain information from members only */
                if (tmpdev && tmpdev->used == 1) {
                        if (!pol)
                                pol = devid_policy(rdev);
                        domain_merge(&domains, pol, tst?tst->ss->name:NULL);
                }
                dev_policy_free(pol);
                pol = NULL;
                if (tst)
                        tst->ss->free_super(tst);
        }

        /* Check if we found some imsm spares but no members */
        if ((auto_assem ||
             (ident->uuid_set &&
              memcmp(uuid_zero, ident->uuid,sizeof(uuid_zero)) == 0)) &&
            (!st || !st->sb))
                for (tmpdev = devlist; tmpdev; tmpdev = tmpdev->next) {
                        if (tmpdev->used != 3)
                                continue;
                        tmpdev->used = 1;
                        content = *contentp;

                        if (!st->sb) {
                                /* we need sb from one of the spares */
                                int dfd = dev_open(tmpdev->devname, O_RDONLY);
                                if (dfd < 0 ||
                                    st->ss->load_super(st, dfd, NULL))
                                        tmpdev->used = 2;
                                close_fd(&dfd);
                        }
                }

        /* Now reject spares that don't match domains of identified members */
        for (tmpdev = devlist; tmpdev; tmpdev = tmpdev->next) {
                if (tmpdev->used != 3)
                        continue;
                if (!stat_is_blkdev(tmpdev->devname, &rdev)) {
                        tmpdev->used = 2;
                } else {
                        struct dev_policy *pol = devid_policy(rdev);
                        int dt = domain_test(domains, pol, NULL);
                        if (inargv && dt != 0)
                                /* take this spare as domains match
                                 * if there are any */
                                tmpdev->used = 1;
                        else if (!inargv && dt == 1)
                                /* device wasn't explicitly listed, so need
                                 * explicit domain match - which we have */
                                tmpdev->used = 1;
                        else
                                /* if domains don't match mark as unused */
                                tmpdev->used = 0;
                        dev_policy_free(pol);
                }
        }
        domain_free(domains);
        *stp = st;
        if (st && st->sb && content == *contentp)
                st->ss->getinfo_super(st, content, NULL);
        *contentp = content;

        return num_devs;
}

struct devs {
        char *devname;
        int uptodate; /* set once we decide that this device is as
                       * recent as everything else in the array.
                       */
        int included; /* set if the device is already in the array
                       * due to a previous '-I'
                       */
        struct mdinfo i;
};

static int load_devices(struct devs *devices, char *devmap,
                        struct mddev_ident *ident, struct supertype **stp,
                        struct mddev_dev *devlist, struct context *c,
                        struct mdinfo *content,
                        int mdfd, char *mddev,
                        int *most_recentp, int *bestcntp, int **bestp,
                        int inargv)
{
        struct mddev_dev *tmpdev;
        int devcnt = 0;
        int nextspare = 0;
        int bitmap_done = 0;
        int most_recent = -1;
        int bestcnt = 0;
        int *best = *bestp;
        struct supertype *st = *stp;

        for (tmpdev = devlist; tmpdev; tmpdev=tmpdev->next) {
                char *devname = tmpdev->devname;
                struct stat stb;
                struct supertype *tst;
                int i;
                int dfd;
                int disk_state;

                if (tmpdev->used != 1)
                        continue;
                /* looks like a good enough match to update the super block if needed */
                if (c->update) {
                        /* prepare useful information in info structures */
                        struct stat stb2;
                        int err;
                        fstat(mdfd, &stb2);

                        if (strcmp(c->update, "uuid") == 0 && !ident->uuid_set)
                                random_uuid((__u8 *)ident->uuid);

                        if (strcmp(c->update, "ppl") == 0 &&
                            ident->bitmap_fd >= 0) {
                                pr_err("PPL is not compatible with bitmap\n");
                                close(mdfd);
                                free(devices);
                                free(devmap);
                                return -1;
                        }

                        dfd = dev_open(devname,
                                       tmpdev->disposition == 'I'
                                       ? O_RDWR : (O_RDWR|O_EXCL));

                        tst = dup_super(st);
                        if (dfd < 0 || tst->ss->load_super(tst, dfd, NULL) != 0) {
                                pr_err("cannot re-read metadata from %s - aborting\n",
                                       devname);
                                if (dfd >= 0)
                                        close(dfd);
                                close(mdfd);
                                free(devices);
                                free(devmap);
                                tst->ss->free_super(tst);
                                free(tst);
                                *stp = st;
                                return -1;
                        }
                        tst->ss->getinfo_super(tst, content, devmap + devcnt * content->array.raid_disks);

                        memcpy(content->uuid, ident->uuid, 16);
                        strcpy(content->name, ident->name);
                        content->array.md_minor = minor(stb2.st_rdev);

                        if (strcmp(c->update, "byteorder") == 0)
                                err = 0;
                        else if (strcmp(c->update, "home-cluster") == 0) {
                                tst->cluster_name = c->homecluster;
                                err = tst->ss->write_bitmap(tst, dfd, NameUpdate);
                        } else if (strcmp(c->update, "nodes") == 0) {
                                tst->nodes = c->nodes;
                                err = tst->ss->write_bitmap(tst, dfd, NodeNumUpdate);
                        } else if (strcmp(c->update, "revert-reshape") == 0 &&
                                   c->invalid_backup)
                                err = tst->ss->update_super(tst, content,
                                                            "revert-reshape-nobackup",
                                                            devname, c->verbose,
                                                            ident->uuid_set,
                                                            c->homehost);
                        else
                                err = tst->ss->update_super(tst, content, c->update,
                                                            devname, c->verbose,
                                                            ident->uuid_set,
                                                            c->homehost);
                        if (err < 0) {
                                if (err == -1)
                                        pr_err("--update=%s not understood for %s metadata\n",
                                               c->update, tst->ss->name);
                                tst->ss->free_super(tst);
                                free(tst);
                                close(mdfd);
                                close(dfd);
                                free(devices);
                                free(devmap);
                                *stp = st;
                                return -1;
                        }
                        if (strcmp(c->update, "uuid")==0 &&
                            !ident->uuid_set) {
                                ident->uuid_set = 1;
                                memcpy(ident->uuid, content->uuid, 16);
                        }
                        if (tst->ss->store_super(tst, dfd))
                                pr_err("Could not re-write superblock on %s.\n",
                                       devname);

                        if (strcmp(c->update, "uuid")==0 &&
                            ident->bitmap_fd >= 0 && !bitmap_done) {
                                if (bitmap_update_uuid(ident->bitmap_fd,
                                                       content->uuid,
                                                       tst->ss->swapuuid) != 0)
                                        pr_err("Could not update uuid on external bitmap.\n");
                                else
                                        bitmap_done = 1;
                        }
                } else {
                        dfd = dev_open(devname,
                                       tmpdev->disposition == 'I'
                                       ? O_RDWR : (O_RDWR|O_EXCL));
                        tst = dup_super(st);

                        if (dfd < 0 || tst->ss->load_super(tst, dfd, NULL) != 0) {
                                pr_err("cannot re-read metadata from %s - aborting\n",
                                       devname);
                                if (dfd >= 0)
                                        close(dfd);
                                close(mdfd);
                                free(devices);
                                free(devmap);
                                tst->ss->free_super(tst);
                                free(tst);
                                *stp = st;
                                return -1;
                        }
                        tst->ss->getinfo_super(tst, content, devmap + devcnt * content->array.raid_disks);
                }

                fstat(dfd, &stb);
                close(dfd);

                if (c->verbose > 0)
                        pr_err("%s is identified as a member of %s, slot %d%s.\n",
                               devname, mddev, content->disk.raid_disk,
                               (content->disk.state & (1<<MD_DISK_REPLACEMENT)) ? " replacement":"");
                devices[devcnt].devname = devname;
                devices[devcnt].uptodate = 0;
                devices[devcnt].included = (tmpdev->disposition == 'I');
                devices[devcnt].i = *content;
                devices[devcnt].i.disk.major = major(stb.st_rdev);
                devices[devcnt].i.disk.minor = minor(stb.st_rdev);

                disk_state = devices[devcnt].i.disk.state & ~((1<<MD_DISK_FAILFAST) |
                                                              (1<<MD_DISK_WRITEMOSTLY));
                if (disk_state == ((1<<MD_DISK_ACTIVE) | (1<<MD_DISK_SYNC))) {
                        if (most_recent < 0 ||
                            devices[devcnt].i.events
                            > devices[most_recent].i.events) {
                                struct supertype *tmp = tst;
                                tst = st;
                                st = tmp;
                                most_recent = devcnt;
                        }
                }
                tst->ss->free_super(tst);
                free(tst);

                if (content->array.level == LEVEL_MULTIPATH)
                        /* with multipath, the raid_disk from the superblock is meaningless */
                        i = devcnt;
                else
                        i = devices[devcnt].i.disk.raid_disk;
                if (i+1 == 0 || i == MD_DISK_ROLE_JOURNAL) {
                        if (nextspare < content->array.raid_disks*2)
                                nextspare = content->array.raid_disks*2;
                        i = nextspare++;
                } else {
                        /* i is raid_disk - double it so there is room for
                         * replacements */
                        i *= 2;
                        if (devices[devcnt].i.disk.state & (1<<MD_DISK_REPLACEMENT))
                                i++;
                        if (i >= content->array.raid_disks*2 &&
                            i >= nextspare)
                                nextspare = i+1;
                }
                if (i < 10000) {
                        if (i >= bestcnt) {
                                int newbestcnt = i+10;
                                int *newbest = xmalloc(sizeof(int)*newbestcnt);
                                int c;
                                for (c=0; c < newbestcnt; c++)
                                        if (c < bestcnt)
                                                newbest[c] = best[c];
                                        else
                                                newbest[c] = -1;
                                if (best)free(best);
                                best = newbest;
                                bestcnt = newbestcnt;
                        }
                        if (best[i] >=0 &&
                            devices[best[i]].i.events ==
                            devices[devcnt].i.events &&
                            (devices[best[i]].i.disk.minor !=
                             devices[devcnt].i.disk.minor) &&
                            st->ss == &super0 &&
                            content->array.level != LEVEL_MULTIPATH) {
                                /* two different devices with identical superblock.
                                 * Could be a mis-detection caused by overlapping
                                 * partitions.  fail-safe.
                                 */
                                pr_err("WARNING %s and %s appear to have very similar superblocks.\n"
                                       "      If they are really different, please --zero the superblock on one\n"
                                       "      If they are the same or overlap, please remove one from %s.\n",
                                       devices[best[i]].devname, devname,
                                       inargv ? "the list" :
                                       "the\n      DEVICE list in mdadm.conf"
                                        );
                                close(mdfd);
                                free(devices);
                                free(devmap);
                                *stp = st;
                                return -1;
                        }
                        if (best[i] == -1 || (devices[best[i]].i.events
                                              < devices[devcnt].i.events))
                                best[i] = devcnt;
                        else if (st->ss == &super_imsm)
                                best[i+1] = devcnt;
                }
                devcnt++;
        }
        if (most_recent >= 0)
                *most_recentp = most_recent;
        *bestcntp = bestcnt;
        *bestp = best;
        *stp = st;
        return devcnt;
}

static int force_array(struct mdinfo *content,
                       struct devs *devices,
                       int *best, int bestcnt, char *avail,
                       int most_recent,
                       struct supertype *st,
                       struct context *c)
{
        int okcnt = 0;
        while (!enough(content->array.level, content->array.raid_disks,
                       content->array.layout, 1,
                       avail) ||
               (content->reshape_active && content->delta_disks > 0 &&
                !enough(content->array.level, (content->array.raid_disks
                                               - content->delta_disks),
                        content->new_layout, 1, avail))) {
                /* Choose the newest best drive which is
                 * not up-to-date, update the superblock
                 * and add it.
                 */
                int fd;
                struct supertype *tst;
                unsigned long long current_events;
                int chosen_drive = -1;
                int i;

                for (i = 0;
                     i < content->array.raid_disks * 2 && i < bestcnt;
                     i += 2) {
                        int j = best[i];
                        if (j < 0)
                                continue;
                        if (devices[j].uptodate)
                                continue;
                        if (devices[j].i.recovery_start != MaxSector) {
                                int delta;
                                if (!devices[j].i.reshape_active ||
                                    devices[j].i.delta_disks <= 0)
                                        continue;
                                /* When increasing number of devices, an
                                 * added device also appears to be
                                 * recovering.  It is safe to include it
                                 * as long as it won't be a source of
                                 * data.
                                 * For now, just allow for last data
                                 * devices in RAID4 or last devices in RAID4/5/6.
                                 */
                                delta = devices[j].i.delta_disks;
                                if (devices[j].i.array.level >= 4 &&
                                    devices[j].i.array.level <= 6 &&
                                    i/2 >= content->array.raid_disks - delta)
                                        /* OK */;
                                else if (devices[j].i.array.level == 4 &&
                                         i/2 >= content->array.raid_disks - delta - 1)
                                        /* OK */;
                                else
                                        continue;
                        } else if (devices[j].i.reshape_active !=
                            content->reshape_active ||
                            (devices[j].i.reshape_active &&
                            devices[j].i.reshape_progress !=
                            content->reshape_progress))
                                /* Here, it may be a source of data. If two
                                 * devices claim different progresses, it
                                 * means that reshape boundaries differ for
                                 * their own devices. Kernel will only treat
                                 * the first one as reshape progress and
                                 * go on. It may cause disaster, so avoid it.
                                 */
                                continue;
                        if (chosen_drive < 0 ||
                             devices[j].i.events
                            > devices[chosen_drive].i.events)
                                chosen_drive = j;
                }
                if (chosen_drive < 0)
                        break;
                current_events = devices[chosen_drive].i.events;
        add_another:
                if (c->verbose >= 0)
                        pr_err("forcing event count in %s(%d) from %d up to %d\n",
                               devices[chosen_drive].devname,
                               devices[chosen_drive].i.disk.raid_disk,
                               (int)(devices[chosen_drive].i.events),
                               (int)(devices[most_recent].i.events));
                fd = dev_open(devices[chosen_drive].devname,
                              devices[chosen_drive].included ? O_RDWR
                              : (O_RDWR|O_EXCL));
                if (fd < 0) {
                        pr_err("Couldn't open %s for write - not updating\n",
                               devices[chosen_drive].devname);
                        devices[chosen_drive].i.events = 0;
                        continue;
                }
                tst = dup_super(st);
                if (tst->ss->load_super(tst,fd, NULL)) {
                        close(fd);
                        pr_err("RAID superblock disappeared from %s - not updating.\n",
                               devices[chosen_drive].devname);
                        devices[chosen_drive].i.events = 0;
                        continue;
                }
                content->events = devices[most_recent].i.events;
                tst->ss->update_super(tst, content, "force-one",
                                      devices[chosen_drive].devname, c->verbose,
                                      0, NULL);

                if (tst->ss->store_super(tst, fd)) {
                        close(fd);
                        pr_err("Could not re-write superblock on %s\n",
                               devices[chosen_drive].devname);
                        devices[chosen_drive].i.events = 0;
                        tst->ss->free_super(tst);
                        continue;
                }
                close(fd);
                devices[chosen_drive].i.events = devices[most_recent].i.events;
                devices[chosen_drive].uptodate = 1;
                avail[chosen_drive] = 1;
                okcnt++;
                tst->ss->free_super(tst);
                /* If there are any other drives of the same vintage,
                 * add them in as well.  We can't lose and we might gain
                 */
                for (i = 0;
                     i < content->array.raid_disks * 2 && i < bestcnt ;
                     i += 2) {
                        int j = best[i];
                        if (j >= 0 &&
                            !devices[j].uptodate &&
                            devices[j].i.recovery_start == MaxSector &&
                            devices[j].i.events == current_events &&
                            ((!devices[j].i.reshape_active &&
                            !content->reshape_active) ||
                            (devices[j].i.reshape_active ==
                            content->reshape_active &&
                            devices[j].i.reshape_progress ==
                            content->reshape_progress))) {
                                chosen_drive = j;
                                goto add_another;
                        }
                }
        }
        return okcnt;
}

static int start_array(int mdfd,
                       char *mddev,
                       struct mdinfo *content,
                       struct supertype *st,
                       struct mddev_ident *ident,
                       int *best, int bestcnt,
                       int chosen_drive,
                       struct devs *devices,
                       unsigned int okcnt,
                       unsigned int sparecnt,
                       unsigned int rebuilding_cnt,
                       unsigned int journalcnt,
                       struct context *c,
                       int clean, char *avail,
                       int start_partial_ok,
                       int err_ok,
                       int was_forced
        )
{
        int rv;
        int i;
        unsigned int req_cnt;

        if (content->journal_device_required && (content->journal_clean == 0)) {
                if (!c->force) {
                        pr_err("Not safe to assemble with missing or stale journal device, consider --force.\n");
                        return 1;
                }
                pr_err("Journal is missing or stale, starting array read only.\n");
                c->readonly = 1;
        }

        if (content->consistency_policy == CONSISTENCY_POLICY_PPL)
                clean = 1;

        rv = set_array_info(mdfd, st, content);
        if (rv && !err_ok) {
                pr_err("failed to set array info for %s: %s\n",
                       mddev, strerror(errno));
                return 1;
        }
        if (ident->bitmap_fd >= 0) {
                if (ioctl(mdfd, SET_BITMAP_FILE, ident->bitmap_fd) != 0) {
                        pr_err("SET_BITMAP_FILE failed.\n");
                        return 1;
                }
        } else if (ident->bitmap_file) {
                /* From config file */
                int bmfd = open(ident->bitmap_file, O_RDWR);
                if (bmfd < 0) {
                        pr_err("Could not open bitmap file %s\n",
                               ident->bitmap_file);
                        return 1;
                }
                if (ioctl(mdfd, SET_BITMAP_FILE, bmfd) != 0) {
                        pr_err("Failed to set bitmapfile for %s\n", mddev);
                        close(bmfd);
                        return 1;
                }
                close(bmfd);
        }

        /* First, add the raid disks, but add the chosen one last */
        for (i = 0; i <= bestcnt; i++) {
                int j;
                if (i < bestcnt) {
                        j = best[i];
                        if (j == chosen_drive)
                                continue;
                } else
                        j = chosen_drive;

                if (j >= 0 && !devices[j].included) {
                        int dfd;

                        dfd = dev_open(devices[j].devname, O_RDWR|O_EXCL);
                        if (dfd >= 0) {
                                remove_partitions(dfd);
                                close(dfd);
                        }
                        rv = add_disk(mdfd, st, content, &devices[j].i);

                        if (rv) {
                                pr_err("failed to add %s to %s: %s\n",
                                       devices[j].devname, mddev,
                                       strerror(errno));
                                if (errno == EINVAL && content->array.level == 0 &&
                                    content->array.layout != 0) {
                                        cont_err("Possibly your kernel doesn't support RAID0 layouts.\n");
                                        cont_err("Please upgrade.\n");
                                }
                                if (i < content->array.raid_disks * 2 ||
                                    i == bestcnt)
                                        okcnt--;
                                else
                                        sparecnt--;
                        } else if (c->verbose > 0) {
                                pr_err("added %s to %s as %d%s%s\n",
                                       devices[j].devname, mddev,
                                       devices[j].i.disk.raid_disk,
                                       devices[j].uptodate?"":
                                       " (possibly out of date)",
                                       (devices[j].i.disk.state &
                                        (1<<MD_DISK_REPLACEMENT)) ?
                                       " replacement":"");
                        }
                } else if (j >= 0) {
                        if (c->verbose > 0)
                                pr_err("%s is already in %s as %d\n",
                                       devices[j].devname, mddev,
                                       devices[j].i.disk.raid_disk);
                } else if (c->verbose > 0 &&
                           i < content->array.raid_disks * 2 && (i & 1) == 0)
                        pr_err("no uptodate device for slot %d of %s\n",
                               i/2, mddev);
        }

        if (content->array.level == LEVEL_CONTAINER) {
                sysfs_rules_apply(mddev, content);
                if (c->verbose >= 0) {
                        pr_err("Container %s has been assembled with %d drive%s",
                               mddev, okcnt + sparecnt + journalcnt,
                               okcnt + sparecnt + journalcnt == 1 ? "" : "s");
                        if (okcnt < (unsigned)content->array.raid_disks)
                                fprintf(stderr, " (out of %d)\n",
                                        content->array.raid_disks);
                        else
                                fprintf(stderr, "\n");
                }

                if (st->ss->validate_container) {
                        struct mdinfo *devices_list;
                        struct mdinfo *info_devices;
                        unsigned int count;

                        devices_list = NULL;
                        info_devices = xmalloc(sizeof(struct mdinfo) *
                                               (okcnt + sparecnt));
                        for (count = 0; count < okcnt + sparecnt; count++) {
                                info_devices[count] = devices[count].i;
                                info_devices[count].next = devices_list;
                                devices_list = &info_devices[count];
                        }
                        if (st->ss->validate_container(devices_list))
                                pr_err("Mismatch detected!\n");
                        free(info_devices);
                }

                st->ss->free_super(st);
                sysfs_uevent(content, "change");
                if (err_ok && okcnt < (unsigned)content->array.raid_disks)
                        /* Was partial, is still partial, so signal an error
                         * to ensure we don't retry */
                        return 1;
                return 0;
        }

        /* Get number of in-sync devices according to the superblock.
         * We must have this number to start the array without -s or -R
         */
        req_cnt = content->array.working_disks;

        if (c->runstop == 1 ||
            (c->runstop <= 0 &&
             (enough(content->array.level, content->array.raid_disks,
                     content->array.layout, clean, avail) &&
               (okcnt + rebuilding_cnt >= req_cnt || start_partial_ok)))) {
                /* This array is good-to-go.
                 * If a reshape is in progress then we might need to
                 * continue monitoring it.  In that case we start
                 * it read-only and let the grow code make it writable.
                 */
                int rv;

                if (content->reshape_active &&
                    !(content->reshape_active & RESHAPE_NO_BACKUP) &&
                    content->delta_disks <= 0) {
                        if (!c->backup_file) {
                                pr_err("%s: Need a backup file to complete reshape of this array.\n",
                                       mddev);
                                pr_err("Please provided one with \"--backup-file=...\"\n");
                                if (c->update &&
                                    strcmp(c->update, "revert-reshape") == 0)
                                        pr_err("(Don't specify --update=revert-reshape again, that part succeeded.)\n");
                                return 1;
                        }
                        rv = sysfs_set_str(content, NULL,
                                           "array_state", "readonly");
                        if (rv == 0)
                                rv = Grow_continue(mdfd, st, content,
                                                   c->backup_file, 0,
                                                   c->freeze_reshape);
                } else if (c->readonly &&
                           sysfs_attribute_available(content, NULL,
                                                     "array_state")) {
                        rv = sysfs_set_str(content, NULL,
                                           "array_state", "readonly");
                } else
                        rv = ioctl(mdfd, RUN_ARRAY, NULL);
                reopen_mddev(mdfd); /* drop O_EXCL */
                if (rv == 0) {
                        sysfs_rules_apply(mddev, content);
                        if (c->verbose >= 0) {
                                pr_err("%s has been started with %d drive%s",
                                       mddev, okcnt, okcnt==1?"":"s");
                                if (okcnt < (unsigned)content->array.raid_disks)
                                        fprintf(stderr, " (out of %d)",
                                                content->array.raid_disks);
                                if (rebuilding_cnt)
                                        fprintf(stderr, "%s %d rebuilding",
                                                sparecnt?",":" and",
                                                rebuilding_cnt);
                                if (sparecnt)
                                        fprintf(stderr, " and %d spare%s",
                                                sparecnt,
                                                sparecnt == 1 ? "" : "s");
                                if (content->journal_clean)
                                        fprintf(stderr, " and %d journal",
                                                journalcnt);
                                fprintf(stderr, ".\n");
                        }
                        if (content->reshape_active &&
                            content->array.level >= 4 &&
                            content->array.level <= 6) {
                                /* might need to increase the size
                                 * of the stripe cache - default is 256
                                 */
                                int chunk_size = content->array.chunk_size;

                                if (content->reshape_active &&
                                    content->new_chunk > chunk_size)
                                        chunk_size = content->new_chunk;
                                if (256 < 4 * ((chunk_size+4065)/4096)) {
                                        struct mdinfo *sra;

                                        sra = sysfs_read(mdfd, NULL, 0);
                                        if (sra)
                                                sysfs_set_num(sra, NULL,
                                                              "stripe_cache_size",
                                                              (4 * chunk_size / 4096) + 1);
                                        sysfs_free(sra);
                                }
                        }
                        if (okcnt < (unsigned)content->array.raid_disks) {
                                /* If any devices did not get added
                                 * because the kernel rejected them based
                                 * on event count, try adding them
                                 * again providing the action policy is
                                 * 're-add' or greater.  The bitmap
                                 * might allow them to be included, or
                                 * they will become spares.
                                 */
                                for (i = 0; i < bestcnt; i++) {
                                        int j = best[i];
                                        if (j >= 0 && !devices[j].uptodate) {
                                                if (!disk_action_allows(&devices[j].i, st->ss->name, act_re_add))
                                                        continue;
                                                rv = add_disk(mdfd, st, content,
                                                              &devices[j].i);
                                                if (rv == 0 && c->verbose >= 0)
                                                        pr_err("%s has been re-added.\n",
                                                               devices[j].devname);
                                        }
                                }
                        }
                        if (content->array.level == 6 &&
                            okcnt + 1 == (unsigned)content->array.raid_disks &&
                            was_forced) {
                                struct mdinfo *sra;

                                sra = sysfs_read(mdfd, NULL, 0);
                                if (sra)
                                        sysfs_set_str(sra, NULL,
                                                      "sync_action", "repair");
                                sysfs_free(sra);
                        }
                        return 0;
                }
                pr_err("failed to RUN_ARRAY %s: %s\n", mddev, strerror(errno));
                if (errno == 524 /* ENOTSUP */ &&
                    content->array.level == 0 && content->array.layout == 0)
                        cont_err("Please use --update=layout-original or --update=layout-alternate\n");

                if (!enough(content->array.level, content->array.raid_disks,
                            content->array.layout, 1, avail))
                        pr_err("Not enough devices to start the array.\n");
                else if (!enough(content->array.level,
                                 content->array.raid_disks,
                                 content->array.layout, clean, avail))
                        pr_err("Not enough devices to start the array while not clean - consider --force.\n");

                return 1;
        }
        if (c->runstop == -1) {
                pr_err("%s assembled from %d drive%s",
                       mddev, okcnt, okcnt == 1 ? "" : "s");
                if (okcnt != (unsigned)content->array.raid_disks)
                        fprintf(stderr, " (out of %d)",
                                content->array.raid_disks);
                fprintf(stderr, ", but not started.\n");
                return 2;
        }
        if (c->verbose >= -1) {
                pr_err("%s assembled from %d drive%s",
                       mddev, okcnt, okcnt == 1 ? "" : "s");
                if (rebuilding_cnt)
                        fprintf(stderr, "%s %d rebuilding",
                                sparecnt ? "," : " and", rebuilding_cnt);
                if (sparecnt)
                        fprintf(stderr, " and %d spare%s", sparecnt,
                                sparecnt == 1 ? "" : "s");
                if (!enough(content->array.level, content->array.raid_disks,
                            content->array.layout, 1, avail))
                        fprintf(stderr, " - not enough to start the array.\n");
                else if (!enough(content->array.level,
                                 content->array.raid_disks,
                                 content->array.layout, clean, avail))
                        fprintf(stderr, " - not enough to start the array while not clean - consider --force.\n");
                else {
                        if (req_cnt == (unsigned)content->array.raid_disks)
                                fprintf(stderr, " - need all %d to start it",
                                        req_cnt);
                        else
                                fprintf(stderr, " - need %d to start", req_cnt);
                        fprintf(stderr, " (use --run to insist).\n");
                }
        }
        return 1;
}

int Assemble(struct supertype *st, char *mddev,
             struct mddev_ident *ident,
             struct mddev_dev *devlist,
             struct context *c)
{
        /*
         * The task of Assemble is to find a collection of
         * devices that should (according to their superblocks)
         * form an array, and to give this collection to the MD driver.
         * In Linux-2.4 and later, this involves submitting a
         * SET_ARRAY_INFO ioctl with no arg - to prepare
         * the array - and then submit a number of
         * ADD_NEW_DISK ioctls to add disks into
         * the array.  Finally RUN_ARRAY might
         * be submitted to start the array.
         *
         * Much of the work of Assemble is in finding and/or
         * checking the disks to make sure they look right.
         *
         * If mddev is not set, then scan must be set and we
         *  read through the config file for dev+uuid mapping
         *  We recurse, setting mddev, for each device that
         *    - isn't running
         *    - has a valid uuid (or any uuid if !uuidset)
         *
         * If mddev is set, we try to determine state of md.
         *   check version - must be at least 0.90.0
         *   check kernel version.  must be at least 2.4.
         *    If not, we can possibly fall back on START_ARRAY
         *   Try to GET_ARRAY_INFO.
         *     If possible, give up
         *     If not, try to STOP_ARRAY just to make sure
         *
         * If !uuidset and scan, look in conf-file for uuid
         *       If not found, give up
         * If !devlist and scan and uuidset, get list of devs from conf-file
         *
         * For each device:
         *   Check superblock - discard if bad
         *   Check uuid (set if we don't have one) - discard if no match
         *   Check superblock similarity if we have a superblock - discard if different
         *   Record events, devicenum
         * This should give us a list of devices for the array
         * We should collect the most recent event number
         *
         * Count disks with recent enough event count
         * While force && !enough disks
         *    Choose newest rejected disks, update event count
         *     mark clean and rewrite superblock
         * If recent kernel:
         *    SET_ARRAY_INFO
         *    foreach device with recent events : ADD_NEW_DISK
         *    if runstop == 1 || "enough" disks and runstop==0 -> RUN_ARRAY
         * If old kernel:
         *    Check the device numbers in superblock are right
         *    update superblock if any changes
         *    START_ARRAY
         *
         */
        int rv = -1;
        int mdfd = -1;
        int clean;
        int auto_assem = (mddev == NULL && !ident->uuid_set &&
                          ident->super_minor == UnSet && ident->name[0] == 0 &&
                          (ident->container == NULL || ident->member == NULL));
        struct devs *devices = NULL;
        char *devmap;
        int *best = NULL; /* indexed by raid_disk */
        int bestcnt = 0;
        int devcnt;
        unsigned int okcnt, sparecnt, rebuilding_cnt, replcnt, journalcnt;
        int journal_clean = 0;
        int i;
        int was_forced = 0;
        int most_recent = 0;
        int chosen_drive;
        int change = 0;
        int inargv = 0;
        int start_partial_ok = (c->runstop >= 0) &&
                (c->force || devlist==NULL || auto_assem);
        int num_devs;
        struct mddev_dev *tmpdev;
        struct mdinfo info;
        struct mdinfo *content = NULL;
        struct mdinfo *pre_exist = NULL;
        char *avail;
        char *name = NULL;
        char chosen_name[1024];
        struct map_ent *map = NULL;
        struct map_ent *mp;

        /*
         * If any subdevs are listed, then any that don't
         * match ident are discarded.  Remainder must all match and
         * become the array.
         * If no subdevs, then we scan all devices in the config file, but
         * there must be something in the identity
         */

        if (!devlist &&
            ident->uuid_set == 0 &&
            (ident->super_minor < 0 || ident->super_minor == UnSet) &&
            ident->name[0] == 0 &&
            (ident->container == NULL || ident->member == NULL) &&
            ident->devices == NULL) {
                pr_err("No identity information available for %s - cannot assemble.\n",
                       mddev ? mddev : "further assembly");
                return 1;
        }

        if (devlist == NULL)
                devlist = conf_get_devs();
        else if (mddev)
                inargv = 1;

try_again:
        /* We come back here when doing auto-assembly and attempting some
         * set of devices failed.  Those are now marked as ->used==2 and
         * we ignore them and try again
         */
        if (!st && ident->st)
                st = ident->st;
        if (c->verbose>0)
                pr_err("looking for devices for %s\n",
                       mddev ? mddev : "further assembly");

        content = &info;
        if (st && c->force)
                st->ignore_hw_compat = 1;
        num_devs = select_devices(devlist, ident, &st, &content, c,
                                  inargv, auto_assem);
        if (num_devs < 0)
                return 1;

        if (!st || !st->sb || !content)
                return 2;

        /* We have a full set of devices - we now need to find the
         * array device.
         * However there is a risk that we are racing with "mdadm -I"
         * and the array is already partially assembled - we will have
         * rejected any devices already in this address.
         * So we take a lock on the map file - to prevent further races -
         * and look for the uuid in there.  If found and the array is
         * active, we abort.  If found and the array is not active
         * we commit to that md device and add all the contained devices
         * to our list.  We flag them so that we don't try to re-add,
         * but can remove if they turn out to not be wanted.
         */
        if (map_lock(&map))
                pr_err("failed to get exclusive lock on mapfile - continue anyway...\n");
        if (c->update && strcmp(c->update,"uuid") == 0)
                mp = NULL;
        else
                mp = map_by_uuid(&map, content->uuid);
        if (mp) {
                struct mdinfo *dv;
                /* array already exists. */
                pre_exist = sysfs_read(-1, mp->devnm, GET_LEVEL|GET_DEVS);
                if (pre_exist->array.level != UnSet) {
                        pr_err("Found some drive for an array that is already active: %s\n",
                               mp->path);
                        pr_err("giving up.\n");
                        goto out;
                }
                for (dv = pre_exist->devs; dv; dv = dv->next) {
                        /* We want to add this device to our list,
                         * but it could already be there if "mdadm -I"
                         * started *after* we checked for O_EXCL.
                         * If we add it to the top of the list
                         * it will be preferred over later copies.
                         */
                        struct mddev_dev *newdev;
                        char *devname = map_dev(dv->disk.major,
                                                dv->disk.minor,
                                                0);
                        if (!devname)
                                continue;
                        newdev = xmalloc(sizeof(*newdev));
                        newdev->devname = devname;
                        newdev->disposition = 'I';
                        newdev->used = 1;
                        newdev->next = devlist;
                        devlist = newdev;
                        num_devs++;
                }
                strcpy(chosen_name, mp->path);
                if (c->verbose > 0 || mddev == NULL ||
                    strcmp(mddev, chosen_name) != 0)
                        pr_err("Merging with already-assembled %s\n",
                               chosen_name);
                mdfd = open_dev_excl(mp->devnm);
        } else {
                int trustworthy = FOREIGN;
                name = content->name;
                switch (st->ss->match_home(st, c->homehost)
                        ?: st->ss->match_home(st, "any")) {
                case 1:
                        trustworthy = LOCAL;
                        name = strchr(content->name, ':');
                        if (name)
                                name++;
                        else
                                name = content->name;
                        break;
                }
                if (mddev && map_by_name(&map, mddev) != NULL) {
                        pr_err("Cannot create device with %s because is in use\n", mddev);
                        goto out;
                }
                if (!auto_assem)
                        /* If the array is listed in mdadm.conf or on
                         * command line, then we trust the name
                         * even if the array doesn't look local
                         */
                        trustworthy = LOCAL;

                if (name[0] == 0 &&
                    content->array.level == LEVEL_CONTAINER) {
                        name = content->text_version;
                        trustworthy = METADATA;
                }

                if (name[0] && trustworthy != LOCAL &&
                    ! c->require_homehost &&
                    conf_name_is_free(name))
                        trustworthy = LOCAL;

                if (trustworthy == LOCAL &&
                    strchr(name, ':'))
                        /* Ignore 'host:' prefix of name */
                        name = strchr(name, ':')+1;

                mdfd = create_mddev(mddev, name, ident->autof, trustworthy,
                                    chosen_name, 0);
        }
        if (mdfd < 0) {
                st->ss->free_super(st);
                if (auto_assem)
                        goto try_again;
                goto out;
        }
        mddev = chosen_name;
        if (pre_exist == NULL) {
                if (mddev_busy(fd2devnm(mdfd))) {
                        pr_err("%s already active, cannot restart it!\n",
                               mddev);
                        for (tmpdev = devlist ;
                             tmpdev && tmpdev->used != 1;
                             tmpdev = tmpdev->next)
                                ;
                        if (tmpdev && auto_assem)
                                pr_err("%s needed for %s...\n",
                                       mddev, tmpdev->devname);
                        close(mdfd);
                        mdfd = -3;
                        st->ss->free_super(st);
                        if (auto_assem)
                                goto try_again;
                        goto out;
                }
                /* just incase it was started but has no content */
                ioctl(mdfd, STOP_ARRAY, NULL);
        }

        if (content != &info) {
                /* This is a member of a container.  Try starting the array. */
                int err;
                err = assemble_container_content(st, mdfd, content, c,
                                                 chosen_name, NULL);
                close(mdfd);
                return err;
        }

        /* Ok, no bad inconsistancy, we can try updating etc */
        devices = xcalloc(num_devs, sizeof(*devices));
        devmap = xcalloc(num_devs, content->array.raid_disks);
        devcnt = load_devices(devices, devmap, ident, &st, devlist,
                              c, content, mdfd, mddev,
                              &most_recent, &bestcnt, &best, inargv);
        if (devcnt < 0) {
                mdfd = -3;
                /*
                 * devices is already freed in load_devices, so set devices
                 * to NULL to avoid double free devices.
                 */
                devices = NULL;
                goto out;
        }

        if (devcnt == 0) {
                pr_err("no devices found for %s\n",
                       mddev);
                if (st)
                        st->ss->free_super(st);
                free(devmap);
                goto out;
        }

        if (c->update && strcmp(c->update, "byteorder")==0)
                st->minor_version = 90;

        st->ss->getinfo_super(st, content, NULL);
        clean = content->array.state & 1;

        /* now we have some devices that might be suitable.
         * I wonder how many
         */
        avail = xcalloc(content->array.raid_disks, 1);
        okcnt = 0;
        replcnt = 0;
        sparecnt=0;
        journalcnt=0;
        rebuilding_cnt=0;
        for (i=0; i< bestcnt; i++) {
                int j = best[i];
                int event_margin = 1; /* always allow a difference of '1'
                                       * like the kernel does
                                       */
                if (j < 0) continue;
                /* note: we ignore error flags in multipath arrays
                 * as they don't make sense
                 */
                if (content->array.level != LEVEL_MULTIPATH) {
                        if (devices[j].i.disk.state & (1<<MD_DISK_JOURNAL)) {
                                if (content->journal_device_required)
                                        journalcnt++;
                                else    /* unexpected journal, mark as faulty */
                                        devices[j].i.disk.state |= (1<<MD_DISK_FAULTY);
                        } else if (!(devices[j].i.disk.state & (1<<MD_DISK_ACTIVE))) {
                                if (!(devices[j].i.disk.state
                                      & (1<<MD_DISK_FAULTY))) {
                                        devices[j].uptodate = 1;
                                        sparecnt++;
                                }
                                continue;
                        }
                }
                /* If this device thinks that 'most_recent' has failed, then
                 * we must reject this device.
                 */
                if (j != most_recent && !c->force &&
                    content->array.raid_disks > 0 &&
                    devices[most_recent].i.disk.raid_disk >= 0 &&
                    devmap[j * content->array.raid_disks + devices[most_recent].i.disk.raid_disk] == 0) {
                        if (c->verbose > -1)
                                pr_err("ignoring %s as it reports %s as failed\n",
                                       devices[j].devname, devices[most_recent].devname);
                        best[i] = -1;
                        continue;
                }
                /* Require event counter to be same as, or just less than,
                 * most recent.  If it is bigger, it must be a stray spare and
                 * should be ignored.
                 */
                if (devices[j].i.events+event_margin >=
                    devices[most_recent].i.events &&
                    devices[j].i.events <=
                    devices[most_recent].i.events
                        ) {
                        devices[j].uptodate = 1;
                        if (devices[j].i.disk.state & (1<<MD_DISK_JOURNAL))
                                journal_clean = 1;
                        if (i < content->array.raid_disks * 2) {
                                if (devices[j].i.recovery_start == MaxSector ||
                                    (content->reshape_active &&
                                     i >= content->array.raid_disks - content->delta_disks)) {
                                        if (!avail[i/2]) {
                                                okcnt++;
                                                avail[i/2]=1;
                                        } else
                                                replcnt++;
                                } else
                                        rebuilding_cnt++;
                        } else if (devices[j].i.disk.raid_disk != MD_DISK_ROLE_JOURNAL)
                                sparecnt++;
                }
        }
        free(devmap);
        if (c->force) {
                int force_ok = force_array(content, devices, best, bestcnt,
                                           avail, most_recent, st, c);
                okcnt += force_ok;
                if (force_ok)
                        was_forced = 1;
        }
        /* Now we want to look at the superblock which the kernel will base things on
         * and compare the devices that we think are working with the devices that the
         * superblock thinks are working.
         * If there are differences and --force is given, then update this chosen
         * superblock.
         */
        chosen_drive = -1;
        st->ss->free_super(st);
        for (i=0; chosen_drive < 0 && i<bestcnt; i+=2) {
                int j = best[i];
                int fd;

                if (j<0)
                        continue;
                if (!devices[j].uptodate)
                        continue;
                if (devices[j].i.events < devices[most_recent].i.events)
                        continue;
                chosen_drive = j;
                if ((fd=dev_open(devices[j].devname,
                                 devices[j].included ? O_RDONLY
                                 : (O_RDONLY|O_EXCL)))< 0) {
                        pr_err("Cannot open %s: %s\n",
                               devices[j].devname, strerror(errno));
                        goto out;
                }
                if (st->ss->load_super(st,fd, NULL)) {
                        close(fd);
                        pr_err("RAID superblock has disappeared from %s\n",
                               devices[j].devname);
                        goto out;
                }
                close(fd);
        }
        if (st->sb == NULL) {
                pr_err("No suitable drives found for %s\n", mddev);
                goto out;
        }
        st->ss->getinfo_super(st, content, NULL);
        if (sysfs_init(content, mdfd, NULL)) {
                pr_err("Unable to initialize sysfs\n");
                goto out;
        }

        /* after reload context, store journal_clean in context */
        content->journal_clean = journal_clean;
        for (i=0; i<bestcnt; i++) {
                int j = best[i];
                unsigned int desired_state;

                if (j < 0)
                        continue;
                if (devices[j].i.disk.raid_disk == MD_DISK_ROLE_JOURNAL)
                        desired_state = (1<<MD_DISK_JOURNAL);
                else if (i >= content->array.raid_disks * 2)
                        desired_state = 0;
                else if (i & 1)
                        desired_state = (1<<MD_DISK_ACTIVE) | (1<<MD_DISK_REPLACEMENT);
                else
                        desired_state = (1<<MD_DISK_ACTIVE) | (1<<MD_DISK_SYNC);

                desired_state |= devices[j].i.disk.state & ((1<<MD_DISK_FAILFAST) |
                                                            (1<<MD_DISK_WRITEMOSTLY));

                if (!devices[j].uptodate)
                        continue;

                devices[j].i.disk.state = desired_state;
                if (!(devices[j].i.array.state & 1))
                        clean = 0;

                if (st->ss->update_super(st, &devices[j].i, "assemble", NULL,
                                         c->verbose, 0, NULL)) {
                        if (c->force) {
                                if (c->verbose >= 0)
                                        pr_err("clearing FAULTY flag for device %d in %s for %s\n",
                                               j, mddev, devices[j].devname);
                                change = 1;
                        } else {
                                if (c->verbose >= -1)
                                        pr_err("device %d in %s has wrong state in superblock, but %s seems ok\n",
                                               i, mddev, devices[j].devname);
                        }
                }
#if 0
                if (!(super.disks[i].i.disk.state & (1 << MD_DISK_FAULTY))) {
                        pr_err("devices %d of %s is not marked FAULTY in superblock, but cannot be found\n",
                               i, mddev);
                }
#endif
        }
        if (c->force && !clean &&
            !enough(content->array.level, content->array.raid_disks,
                    content->array.layout, clean,
                    avail)) {
                change += st->ss->update_super(st, content, "force-array",
                                               devices[chosen_drive].devname, c->verbose,
                                               0, NULL);
                was_forced = 1;
                clean = 1;
        }

        if (change) {
                int fd;
                fd = dev_open(devices[chosen_drive].devname,
                              devices[chosen_drive].included ?
                              O_RDWR : (O_RDWR|O_EXCL));
                if (fd < 0) {
                        pr_err("Could not open %s for write - cannot Assemble array.\n",
                               devices[chosen_drive].devname);
                        goto out;
                }
                if (st->ss->store_super(st, fd)) {
                        close(fd);
                        pr_err("Could not re-write superblock on %s\n",
                               devices[chosen_drive].devname);
                        goto out;
                }
                if (c->verbose >= 0)
                        pr_err("Marking array %s as 'clean'\n",
                               mddev);
                close(fd);
        }

        /* If we are in the middle of a reshape we may need to restore saved data
         * that was moved aside due to the reshape overwriting live data
         * The code of doing this lives in Grow.c
         */
        if (content->reshape_active &&
            !(content->reshape_active & RESHAPE_NO_BACKUP)) {
                int err = 0;
                int *fdlist = xmalloc(sizeof(int)* bestcnt);
                if (c->verbose > 0)
                        pr_err("%s has an active reshape - checking if critical section needs to be restored\n",
                               chosen_name);
                if (!c->backup_file)
                        c->backup_file = locate_backup(content->sys_name);
                enable_fds(bestcnt/2);
                for (i = 0; i < bestcnt/2; i++) {
                        int j = best[i*2];
                        if (j >= 0) {
                                fdlist[i] = dev_open(devices[j].devname,
                                                     devices[j].included
                                                     ? O_RDWR : (O_RDWR|O_EXCL));
                                if (fdlist[i] < 0) {
                                        pr_err("Could not open %s for write - cannot Assemble array.\n",
                                               devices[j].devname);
                                        err = 1;
                                        break;
                                }
                        } else
                                fdlist[i] = -1;
                }
                if (!err) {
                        if (st->ss->external && st->ss->recover_backup)
                                err = st->ss->recover_backup(st, content);
                        else
                                err = Grow_restart(st, content, fdlist, bestcnt/2,
                                                   c->backup_file, c->verbose > 0);
                        if (err && c->invalid_backup) {
                                if (c->verbose > 0)
                                        pr_err("continuing without restoring backup\n");
                                err = 0;
                        }
                }
                while (i>0) {
                        i--;
                        if (fdlist[i]>=0) close(fdlist[i]);
                }
                free(fdlist);
                if (err) {
                        pr_err("Failed to restore critical section for reshape, sorry.\n");
                        if (c->backup_file == NULL)
                                cont_err("Possibly you needed to specify the --backup-file\n");
                        goto out;
                }
        }

        /* Almost ready to actually *do* something */
        /* First, fill in the map, so that udev can find our name
         * as soon as we become active.
         */
        if (c->update && strcmp(c->update, "metadata")==0) {
                content->array.major_version = 1;
                content->array.minor_version = 0;
                strcpy(content->text_version, "1.0");
        }

        map_update(&map, fd2devnm(mdfd), content->text_version,
                   content->uuid, chosen_name);

        rv = start_array(mdfd, mddev, content,
                         st, ident, best, bestcnt,
                         chosen_drive, devices, okcnt, sparecnt,
                         rebuilding_cnt, journalcnt,
                         c,
                         clean, avail, start_partial_ok,
                         pre_exist != NULL,
                         was_forced);
        if (rv == 1 && !pre_exist)
                ioctl(mdfd, STOP_ARRAY, NULL);
        free(devices);
out:
        map_unlock(&map);
        if (rv == 0) {
                wait_for(chosen_name, mdfd);
                close(mdfd);
                if (auto_assem) {
                        int usecs = 1;
                        /* There is a nasty race with 'mdadm --monitor'.
                         * If it opens this device before we close it,
                         * it gets an incomplete open on which IO
                         * doesn't work and the capacity is
                         * wrong.
                         * If we reopen (to check for layered devices)
                         * before --monitor closes, we loose.
                         *
                         * So: wait upto 1 second for there to be
                         * a non-zero capacity.
                         */
                        while (usecs < 1000) {
                                mdfd = open(mddev, O_RDONLY);
                                if (mdfd >= 0) {
                                        unsigned long long size;
                                        if (get_dev_size(mdfd, NULL, &size) &&
                                            size > 0)
                                                break;
                                        close(mdfd);
                                }
                                usleep(usecs);
                                usecs <<= 1;
                        }
                }
        } else if (mdfd >= 0)
                close(mdfd);

        /* '2' means 'OK, but not started yet' */
        if (rv == -1) {
                free(devices);
                return 1;
        }
        return rv == 2 ? 0 : rv;
}

int assemble_container_content(struct supertype *st, int mdfd,
                               struct mdinfo *content, struct context *c,
                               char *chosen_name, int *result)
{
        struct mdinfo *dev, *sra, *dev2;
        struct assembly_array_info array = {chosen_name, 0, 0, 0};
        int old_raid_disks;
        int start_reshape;
        char *avail;
        int err;
        int is_raid456, is_clean, all_disks;

        if (sysfs_init(content, mdfd, NULL)) {
                pr_err("Unable to initialize sysfs\n");
                return 1;
        }

        sra = sysfs_read(mdfd, NULL, GET_VERSION|GET_DEVS);
        if (sra == NULL || strcmp(sra->text_version, content->text_version) != 0) {
                if (content->array.major_version == -1 &&
                    content->array.minor_version == -2 &&
                    c->readonly &&
                    content->text_version[0] == '/')
                        content->text_version[0] = '-';
                if (sysfs_set_array(content, 9003) != 0) {
                        sysfs_free(sra);
                        return 1;
                }
        }

        /* There are two types of reshape: container wide or sub-array specific
         * Check if metadata requests blocking container wide reshapes
         */
        start_reshape = (content->reshape_active &&
                         !((content->reshape_active == CONTAINER_RESHAPE) &&
                           (content->array.state & (1<<MD_SB_BLOCK_CONTAINER_RESHAPE))));

        /* Block subarray here if it is under reshape now
         * Do not allow for any changes in this array
         */
        if (st->ss->external && content->recovery_blocked && start_reshape)
                block_subarray(content);

        for (dev2 = sra->devs; dev2; dev2 = dev2->next) {
                for (dev = content->devs; dev; dev = dev->next)
                        if (dev2->disk.major == dev->disk.major &&
                            dev2->disk.minor == dev->disk.minor)
                                break;
                if (dev)
                        continue;
                /* Don't want this one any more */
                if (sysfs_set_str(sra, dev2, "slot", "none") < 0 &&
                    errno == EBUSY) {
                        pr_err("Cannot remove old device %s: not updating %s\n", dev2->sys_name, sra->sys_name);
                        sysfs_free(sra);
                        return 1;
                }
                sysfs_set_str(sra, dev2, "state", "remove");
        }
        old_raid_disks = content->array.raid_disks - content->delta_disks;
        avail = xcalloc(content->array.raid_disks, 1);
        for (dev = content->devs; dev; dev = dev->next) {
                if (dev->disk.raid_disk >= 0)
                        avail[dev->disk.raid_disk] = 1;
                if (sysfs_add_disk(content, dev, 1) == 0) {
                        if (dev->disk.raid_disk >= old_raid_disks &&
                            content->reshape_active)
                                array.exp_cnt++;
                        else
                                array.new_cnt++;
                } else if (errno == EEXIST)
                        array.preexist_cnt++;
        }
        sysfs_free(sra);

        all_disks = array.new_cnt + array.exp_cnt + array.preexist_cnt;

        map_update(NULL, fd2devnm(mdfd), content->text_version,
                   content->uuid, chosen_name);

        if (content->consistency_policy == CONSISTENCY_POLICY_PPL &&
            st->ss->validate_ppl) {
                content->array.state |= 1;
                err = 0;

                for (dev = content->devs; dev; dev = dev->next) {
                        int dfd;
                        char *devpath;
                        int ret;

                        ret = st->ss->validate_ppl(st, content, dev);
                        if (ret == 0)
                                continue;

                        if (ret < 0) {
                                err = 1;
                                break;
                        }

                        if (!c->force) {
                                pr_err("%s contains invalid PPL - consider --force or --update-subarray with --update=no-ppl\n",
                                        chosen_name);
                                content->array.state &= ~1;
                                avail[dev->disk.raid_disk] = 0;
                                break;
                        }

                        /* have --force - overwrite the invalid ppl */
                        devpath = map_dev(dev->disk.major, dev->disk.minor, 0);
                        dfd = dev_open(devpath, O_RDWR);
                        if (dfd < 0) {
                                pr_err("Failed to open %s\n", devpath);
                                err = 1;
                                break;
                        }

                        err = st->ss->write_init_ppl(st, content, dfd);
                        close(dfd);

                        if (err)
                                break;
                }

                if (err) {
                        free(avail);
                        return err;
                }
        } else if (c->force) {
                /* Set the array as 'clean' so that we can proceed with starting
                 * it even if we don't have all devices. Mdmon doesn't care
                 * if the dirty flag is set in metadata, it will start managing
                 * it anyway.
                 * This is really important for raid456 (RWH case), other levels
                 * are started anyway.
                 */
                content->array.state |= 1;
        }

        is_raid456 = (content->array.level >= 4 && content->array.level <= 6);
        is_clean = content->array.state & 1;

        if (enough(content->array.level, content->array.raid_disks,
                   content->array.layout, is_clean, avail) == 0) {
                set_array_assembly_status(c, result, INCR_NO, &array);

                if (c->verbose >= 0 && is_raid456 && !is_clean)
                        pr_err("Consider --force to start dirty degraded array\n");

                free(avail);
                return 1;
        }
        free(avail);

        if (c->runstop <= 0 && all_disks < content->array.working_disks) {

                set_array_assembly_status(c, result, INCR_UNSAFE, &array);

                if (c->verbose >= 0 && c->force)
                        pr_err("Consider --run to start array as degraded.\n");
                return 1;
        }

        if (is_raid456 && content->resync_start != MaxSector && c->force &&
            all_disks < content->array.raid_disks) {

                content->resync_start = MaxSector;
                err = sysfs_set_num(content, NULL, "resync_start", MaxSector);
                if (err)
                        return 1;

                pr_err("%s array state forced to clean. It may cause data corruption.\n",
                       chosen_name);
        }

        /*
         * Before activating the array, perform extra steps required
         * to configure the internal write-intent bitmap.
         */
        if (content->consistency_policy == CONSISTENCY_POLICY_BITMAP &&
            st->ss->set_bitmap)
                st->ss->set_bitmap(st, content);

        if (start_reshape) {
                int spare = content->array.raid_disks + array.exp_cnt;
                if (restore_backup(st, content,
                                   array.new_cnt,
                                   spare, &c->backup_file, c->verbose) == 1)
                        return 1;

                if (content->reshape_progress == 0) {
                        /* If reshape progress is 0 - we are assembling the
                         * array that was stopped, before reshape has started.
                         * Array needs to be started as active, Grow_continue()
                         * will start the reshape.
                         */
                        sysfs_set_num(content, NULL, "reshape_position",
                                      MaxSector);
                        err = sysfs_set_str(content, NULL,
                                            "array_state", "active");
                        sysfs_set_num(content, NULL, "reshape_position", 0);
                } else {
                        err = sysfs_set_str(content, NULL,
                                            "array_state", "readonly");
                }

                if (err)
                        return 1;

                if (st->ss->external) {
                        if (!mdmon_running(st->container_devnm))
                                start_mdmon(st->container_devnm);
                        ping_monitor(st->container_devnm);
                        if (mdmon_running(st->container_devnm) &&
                            st->update_tail == NULL)
                                st->update_tail = &st->updates;
                }

                err = Grow_continue(mdfd, st, content, c->backup_file,
                                    0, c->freeze_reshape);
        } else switch(content->array.level) {
                case LEVEL_LINEAR:
                case LEVEL_MULTIPATH:
                case 0:
                        err = sysfs_set_str(content, NULL, "array_state",
                                            c->readonly ? "readonly" : "active");
                        break;
                default:
                        err = sysfs_set_str(content, NULL, "array_state",
                                            "readonly");
                        /* start mdmon if needed. */
                        if (!err) {
                                if (!mdmon_running(st->container_devnm))
                                        start_mdmon(st->container_devnm);
                                ping_monitor(st->container_devnm);
                        }
                        break;
                }
        if (!err)
                sysfs_set_safemode(content, content->safe_mode_delay);

        /* Block subarray here if it is not reshaped now
         * It has be blocked a little later to allow mdmon to switch in
         * in to R/W state
         */
        if (st->ss->external && content->recovery_blocked &&
            !start_reshape)
                block_subarray(content);

        if (err)
                set_array_assembly_status(c, result, INCR_NO, &array);
        else {
                set_array_assembly_status(c, result, INCR_YES, &array);
                wait_for(chosen_name, mdfd);
                sysfs_rules_apply(chosen_name, content);
        }

        return err;
        /* FIXME should have an O_EXCL and wait for read-auto */
}