continue;
if (st->ss->load_super(st, fd2, &super, NULL)==0) {
if (st->ss->add_internal_bitmap(st, super,
- chunk, delay, write_behind,
+ chunk, delay, write_behind,
bitmapsize, 0, major))
st->ss->write_bitmap(st, fd2, super);
else {
return 0;
}
+
+/*
+ * When reshaping an array we might need to backup some data.
+ * This is written to all spares with a 'super_block' describing it.
+ * The superblock goes 1K form the end of the used space on the
+ * device.
+ * It if written after the backup is complete.
+ * It has the following structure.
+ */
+
+struct mdp_backup_super {
+ char magic[16]; /* md_backup_data-1 */
+ __u8 set_uuid[16];
+ __u64 mtime;
+ /* start/sizes in 512byte sectors */
+ __u64 devstart;
+ __u64 arraystart;
+ __u64 length;
+ __u32 sb_csum; /* csum of preceeding bytes. */
+};
+
+int bsb_csum(char *buf, int len)
+{
+ int i;
+ int csum = 0;
+ for (i=0; i<len; i++)
+ csum = (csum<<3) + buf[0];
+ return __cpu_to_le32(csum);
+}
+
+int Grow_reshape(char *devname, int fd, int quiet,
+ long long size,
+ int level, int layout, int chunksize, int raid_disks)
+{
+ /* Make some changes in the shape of an array.
+ * The kernel must support the change.
+ * Different reshapes have subtly different meaning for different
+ * levels, so we need to check the current state of the array
+ * and go from there.
+ */
+ struct mdu_array_info_s array;
+ char *c;
+
+ struct mdp_backup_super bsb;
+ struct supertype *st;
+
+ int nlevel, olevel;
+ int nchunk, ochunk;
+ int nlayout, olayout;
+ int ndisks, odisks;
+ int ndata, odata;
+ unsigned long long nstripe, ostripe, last_block;
+ int *fdlist;
+ unsigned long long *offsets;
+ int d, i, spares;
+ int nrdisks;
+ int err;
+ void *super = NULL;
+
+ struct sysarray *sra;
+ struct sysdev *sd;
+
+ if (ioctl(fd, GET_ARRAY_INFO, &array) < 0) {
+ fprintf(stderr, Name ": %s is not an active md array - aborting\n",
+ devname);
+ return 1;
+ }
+ c = map_num(pers, array.level);
+ if (c == NULL) c = "-unknown-";
+ switch(array.level) {
+ default: /* raid0, linear, multipath cannot be reconfigured */
+ fprintf(stderr, Name ": %s array %s cannot be reshaped.\n",
+ c, devname);
+ return 1;
+
+ case LEVEL_FAULTY: /* only 'layout' change is permitted */
+
+ if (size >= 0) {
+ fprintf(stderr, Name ": %s: Cannot change size of a 'faulty' array\n",
+ devname);
+ return 1;
+ }
+ if (level != UnSet && level != LEVEL_FAULTY) {
+ fprintf(stderr, Name ": %s: Cannot change RAID level of a 'faulty' array\n",
+ devname);
+ return 1;
+ }
+ if (chunksize || raid_disks) {
+ fprintf(stderr, Name ": %s: Cannot change chunksize or disks of a 'faulty' array\n",
+ devname);
+ return 1;
+ }
+ if (layout == UnSet)
+ return 0; /* nothing to do.... */
+
+ array.layout = layout;
+ if (ioctl(fd, SET_ARRAY_INFO, &array) != 0) {
+ fprintf(stderr, Name ": Cannot set layout for %s: %s\n",
+ devname, strerror(errno));
+ return 1;
+ }
+ if (!quiet)
+ printf("layout for %s set to %d\n", devname, array.layout);
+ return 0;
+
+ case 1: /* raid_disks and size can each be changed. They are independant */
+
+ if (level != UnSet && level != 1) {
+ fprintf(stderr, Name ": %s: Cannot change RAID level of a RAID1 array.\n",
+ devname);
+ return 1;
+ }
+ if (chunksize || layout != UnSet) {
+ fprintf(stderr, Name ": %s: Cannot change chunk size of layout for a RAID1 array.\n",
+ devname);
+ return 1;
+ }
+
+ /* Each can trigger a resync/recovery which will block the
+ * other from happening. Later we could block
+ * resync for the duration via 'sync_action'...
+ */
+ if (raid_disks >= 0)
+ array.raid_disks = raid_disks;
+ if (size >= 0)
+ array.size = size;
+ if (ioctl(fd, SET_ARRAY_INFO, &array) != 0) {
+ fprintf(stderr, Name ": Cannot set device size/shape for %s: %s\n",
+ devname, strerror(errno));
+ return 1;
+ }
+ return 0;
+
+ case 4:
+ case 5:
+ case 6:
+ st = super_by_version(array.major_version,
+ array.minor_version);
+ /* size can be changed independantly.
+ * layout/chunksize/raid_disks/level can be changed
+ * though the kernel may not support it all.
+ * If 'suspend_lo' is not present in devfs, then
+ * these cannot be changed.
+ */
+ if (size >= 0) {
+ /* Cannot change other details as well.. */
+ if (layout != UnSet ||
+ chunksize != 0 ||
+ raid_disks != 0 ||
+ level != UnSet) {
+ fprintf(stderr, Name ": %s: Cannot change shape as well as size of a %s array.\n",
+ devname, c);
+ return 1;
+ }
+ array.size = size;
+ if (ioctl(fd, SET_ARRAY_INFO, &array) != 0) {
+ fprintf(stderr, Name ": Cannot set device size/shape for %s: %s\n",
+ devname, strerror(errno));
+ return 1;
+ }
+ return 0;
+ }
+ /* Ok, just change the shape. This can be awkward.
+ * There are three possibilities.
+ * 1/ The array will shrink. We don't support this
+ * possibility. Maybe one day...
+ * 2/ The array will not change size. This is easy enough
+ * to do, but not reliably. If the process is aborted
+ * the array *will* be corrupted. So maybe we can allow
+ * this but only if the user is really certain. e.g.
+ * --really-risk-everything
+ * 3/ The array will grow. This can be reliably achieved.
+ * However the kernel's restripe routines will cheerfully
+ * overwrite some early data before it is safe. So we
+ * need to make a backup of the early parts of the array
+ * and be ready to restore it if rebuild aborts very early.
+ *
+ * We backup data by writing it to all spares (there must be
+ * at least 1, so even raid6->raid5 requires a spare to be
+ * present).
+ *
+ * So: we enumerate the devices in the array and
+ * make sure we can open all of them.
+ * Then we freeze the early part of the array and
+ * backup to the various spares.
+ * Then we request changes and start the reshape.
+ * Monitor progress until it has passed the danger zone.
+ * and finally invalidate the copied data and unfreeze the
+ * start of the array.
+ *
+ * Before we can do this we need to decide:
+ * - will the array grow? Just calculate size
+ * - how much needs to be saved: count stripes.
+ * - where to save data... good question.
+ *
+ */
+ nlevel = olevel = array.level;
+ nchunk = ochunk = array.chunk_size;
+ nlayout = olayout = array.layout;
+ ndisks = odisks = array.raid_disks;
+
+ if (level != UnSet) nlevel = level;
+ if (chunksize) nchunk = chunksize;
+ if (layout != UnSet) nlayout = layout;
+ if (raid_disks) ndisks = raid_disks;
+
+ odata = odisks-1;
+ if (olevel == 6) odata--; /* number of data disks */
+ ndata = ndisks-1;
+ if (nlevel == 6) ndata--;
+
+ if (ndata < odata) {
+ fprintf(stderr, Name ": %s: Cannot reduce number of data disks (yet).\n",
+ devname);
+ return 1;
+ }
+ if (ndata == odata) {
+ fprintf(stderr, Name ": %s: Cannot reshape array without increasing size (yet).\n",
+ devname);
+ return 1;
+ }
+ /* Well, it is growing... so how much do we need to backup.
+ * Need to backup a full number of new-stripes, such that the
+ * last one does not over-write any place that it would be read
+ * from
+ */
+ nstripe = ostripe = 0;
+ while (nstripe+ochunk/512 >= ostripe) {
+ nstripe += nchunk/512;
+ last_block = nstripe * ndata;
+ ostripe = last_block / odata;
+ }
+ printf("Need to backup to stripe %llu sectors, %lluK\n", nstripe, last_block/2);
+
+ sra = sysfs_read(fd, 0,
+ GET_COMPONENT|GET_DEVS|GET_OFFSET|GET_STATE);
+ if (!sra) {
+ fprintf(stderr, Name ": %s: Cannot get array details from sysfs\n",
+ devname);
+ return 1;
+ }
+
+ if (last_block >= sra->component_size/2) {
+ fprintf(stderr, Name ": %s: Something wrong - reshape aborted\n",
+ devname);
+ return 1;
+ }
+
+ nrdisks = array.nr_disks + sra->spares;
+ /* Now we need to open all these devices so we can read/write.
+ */
+ fdlist = malloc(nrdisks * sizeof(int));
+ offsets = malloc(nrdisks * sizeof(offsets[0]));
+ if (!fdlist || !offsets) {
+ fprintf(stderr, Name ": malloc failed: grow aborted\n");
+ return 1;
+ }
+ for (d=0; d< nrdisks; d++)
+ fdlist[d] = -1;
+ d = array.raid_disks;
+ for (sd = sra->devs; sd; sd=sd->next) {
+ if (sd->state & (1<<MD_DISK_FAULTY))
+ continue;
+ if (sd->state & (1<<MD_DISK_SYNC)) {
+ char *dn = map_dev(sd->major, sd->minor);
+ fdlist[sd->role] = open(dn, O_RDONLY);
+ offsets[sd->role] = sd->offset;
+ if (fdlist[sd->role] < 0) {
+ fprintf(stderr, Name ": %s: cannot open component %s\n",
+ devname, dn);
+ goto abort;
+ }
+ } else {
+ /* spare */
+ char *dn = map_dev(sd->major, sd->minor);
+ fdlist[d] = open(dn, O_RDWR);
+ offsets[d] = sd->offset;
+ if (fdlist[d]<0) {
+ fprintf(stderr, Name ": %s: cannot open component %s\n",
+ devname, dn);
+ goto abort;
+ }
+ d++;
+ }
+ }
+ for (i=0 ; i<array.raid_disks; i++)
+ if (fdlist[i] < 0) {
+ fprintf(stderr, Name ": %s: failed to find device %d. Array might be degraded.\n"
+ " --grow aborted\n", devname, i);
+ goto abort;
+ }
+ if (fdlist[array.raid_disks] < 0) {
+ fprintf(stderr, Name ": %s: failed to find a spare - --grow aborted\n",
+ devname);
+ goto abort;
+ }
+
+ /* Find a superblock */
+ if (st->ss->load_super(st, fdlist[0], &super, NULL)) {
+ fprintf(stderr, Name ": %s: Cannot find a superblock\n",
+ devname);
+ goto abort;
+ }
+
+ spares = sra->spares;
+
+ /* Decide offset for the backup and llseek the spares */
+ for (i=array.raid_disks; i<d; i++) {
+ offsets[i] += sra->component_size - last_block - 8;
+ if (lseek64(fdlist[i], offsets[i]<<9, 0) != offsets[i]<<9) {
+ fprintf(stderr, Name ": could not seek...\n");
+ goto abort;
+ }
+ }
+ array.level = nlevel;
+ array.raid_disks = ndisks;
+ array.chunk_size = nchunk;
+ array.layout = nlayout;
+ if (ioctl(fd, SET_ARRAY_INFO, &array) != 0) {
+ fprintf(stderr, Name ": Cannot set device size/shape for %s: %s\n",
+ devname, strerror(errno));
+ goto abort;
+ }
+
+ /* suspend the relevant region */
+ sysfs_set_num(sra, NULL, "suspend_hi", 0); /* just in case */
+ if (sysfs_set_num(sra, NULL, "suspend_lo", 0) < 0 ||
+ sysfs_set_num(sra, NULL, "suspend_hi", last_block) < 0) {
+ fprintf(stderr, Name ": %s: failed to suspend device.\n",
+ devname);
+ goto abort_resume;
+ }
+
+
+ err = save_stripes(fdlist, offsets,
+ odisks, ochunk, olevel, olayout,
+ spares, fdlist+odisks,
+ 0ULL, nstripe*512);
+
+ /* abort if there was an error */
+ if (err < 0) {
+ fprintf(stderr, Name ": %s: failed to save critical region\n",
+ devname);
+ goto abort_resume;
+ }
+ /* FIXME write superblocks */
+ memcpy(bsb.magic, "md_backups_data-1", 16);
+ st->ss->uuid_from_super((int*)&bsb.set_uuid, super);
+ bsb.mtime = time(0);
+ bsb.arraystart = 0;
+ bsb.length = last_block;
+ for (i=odisks; i<d ; i++) {
+ bsb.devstart = offsets[i];
+ bsb.sb_csum = bsb_csum((char*)&bsb, ((char*)&bsb.sb_csum)-((char*)&bsb));
+ lseek64(fdlist[i], (offsets[i]+last_block)<<9, 0);
+ write(fdlist[i], &bsb, sizeof(bsb));
+ /* FIXME error check */
+ }
+
+ /* start the reshape happening */
+ if (sysfs_set_str(sra, NULL, "sync_action", "reshape") < 0) {
+ fprintf(stderr, Name ": %s: failed to initiate reshape\n",
+ devname);
+ goto abort_resume;
+ }
+ /* wait for reshape to pass the critical region */
+ while(1) {
+ unsigned long long comp;
+ if (sysfs_get_ll(sra, NULL, "sync_completed", &comp)<0)
+ break;
+ if (comp >= nstripe)
+ break;
+ sleep(1);
+ }
+ /* invalidate superblocks */
+ memset(&bsb, 0, sizeof(bsb));
+ for (i=odisks; i<d ; i++) {
+ lseek64(fdlist[i], (offsets[i]+last_block)<<9, 0);
+ write(fdlist[i], &bsb, sizeof(bsb));
+ }
+
+ /* unsuspend. */
+ sysfs_set_num(sra, NULL, "suspend_lo", last_block);
+
+ for (i=0; i<d; i++)
+ if (fdlist[i] >= 0)
+ close(fdlist[i]);
+ free(fdlist);
+ free(offsets);
+
+ break;
+ }
+ return 0;
+
+
+ abort_resume:
+ sysfs_set_num(sra, NULL, "suspend_lo", last_block);
+ abort:
+ for (i=0; i<array.nr_disks; i++)
+ if (fdlist[i] >= 0)
+ close(fdlist[i]);
+ free(fdlist);
+ free(offsets);
+ return 1;
+
+}
projects / thirdparty / mdadm.git / blobdiff