]> git.ipfire.org Git - thirdparty/mdadm.git/blobdiff - Grow.c
Consistently print program Name and __func__ in debug messages.
[thirdparty/mdadm.git] / Grow.c
diff --git a/Grow.c b/Grow.c
index 9350a07976552e2bb6d23f45e72dc2a1468980c7..f2879768ca70354f6f6707a511af0b1fd7319819 100644 (file)
--- a/Grow.c
+++ b/Grow.c
@@ -1,7 +1,7 @@
 /*
  * mdadm - manage Linux "md" devices aka RAID arrays.
  *
- * Copyright (C) 2001-2009 Neil Brown <neilb@suse.de>
+ * Copyright (C) 2001-2013 Neil Brown <neilb@suse.de>
  *
  *
  *    This program is free software; you can redistribute it and/or modify
 #include       "mdadm.h"
 #include       "dlink.h"
 #include       <sys/mman.h>
+#include       <stddef.h>
+#include       <stdint.h>
+#include       <signal.h>
+#include       <sys/wait.h>
 
 #if ! defined(__BIG_ENDIAN) && ! defined(__LITTLE_ENDIAN)
 #error no endian defined
 #include       "md_u.h"
 #include       "md_p.h"
 
-#ifndef offsetof
-#define offsetof(t,f) ((size_t)&(((t*)0)->f))
-#endif
-
 int restore_backup(struct supertype *st,
                   struct mdinfo *content,
                   int working_disks,
                   int next_spare,
-                  char *backup_file,
+                  char **backup_filep,
                   int verbose)
 {
        int i;
@@ -47,14 +47,12 @@ int restore_backup(struct supertype *st,
        struct mdinfo *dev;
        int err;
        int disk_count = next_spare + working_disks;
+       char *backup_file = *backup_filep;
 
        dprintf("Called restore_backup()\n");
-       fdlist = malloc(sizeof(int) * disk_count);
-       if (fdlist == NULL) {
-               fprintf(stderr,
-                       Name ": cannot allocate memory for disk list\n");
-               return 1;
-       }
+       fdlist = xmalloc(sizeof(int) * disk_count);
+
+       enable_fds(next_spare);
        for (i = 0; i < next_spare; i++)
                fdlist[i] = -1;
        for (dev = content->devs; dev; dev = dev->next) {
@@ -71,6 +69,11 @@ int restore_backup(struct supertype *st,
                        fdlist[next_spare++] = fd;
        }
 
+       if (!backup_file) {
+               backup_file = locate_backup(content->sys_name);
+               *backup_filep = backup_file;
+       }
+
        if (st->ss->external && st->ss->recover_backup)
                err = st->ss->recover_backup(st, content);
        else
@@ -84,10 +87,10 @@ int restore_backup(struct supertype *st,
        }
        free(fdlist);
        if (err) {
-               fprintf(stderr, Name ": Failed to restore critical"
-                       " section for reshape - sorry.\n");
+               pr_err("Failed to restore critical"
+                      " section for reshape - sorry.\n");
                if (!backup_file)
-                       fprintf(stderr, Name ":  Possibly you need"
+                       pr_err("Possibly you need"
                                " to specify a --backup-file\n");
                return 1;
        }
@@ -115,23 +118,24 @@ int Grow_Add_device(char *devname, int fd, char *newdev)
        char *subarray = NULL;
 
        if (ioctl(fd, GET_ARRAY_INFO, &info.array) < 0) {
-               fprintf(stderr, Name ": cannot get array info for %s\n", devname);
+               pr_err("cannot get array info for %s\n", devname);
                return 1;
        }
 
        if (info.array.level != -1) {
-               fprintf(stderr, Name ": can only add devices to linear arrays\n");
+               pr_err("can only add devices to linear arrays\n");
                return 1;
        }
 
        st = super_by_fd(fd, &subarray);
        if (!st) {
-               fprintf(stderr, Name ": cannot handle arrays with superblock version %d\n", info.array.major_version);
+               pr_err("cannot handle arrays with superblock version %d\n",
+                      info.array.major_version);
                return 1;
        }
 
        if (subarray) {
-               fprintf(stderr, Name ": Cannot grow linear sub-arrays yet\n");
+               pr_err("Cannot grow linear sub-arrays yet\n");
                free(subarray);
                free(st);
                return 1;
@@ -139,18 +143,19 @@ int Grow_Add_device(char *devname, int fd, char *newdev)
 
        nfd = open(newdev, O_RDWR|O_EXCL|O_DIRECT);
        if (nfd < 0) {
-               fprintf(stderr, Name ": cannot open %s\n", newdev);
+               pr_err("cannot open %s\n", newdev);
                free(st);
                return 1;
        }
        fstat(nfd, &stb);
        if ((stb.st_mode & S_IFMT) != S_IFBLK) {
-               fprintf(stderr, Name ": %s is not a block device!\n", newdev);
+               pr_err("%s is not a block device!\n", newdev);
                close(nfd);
                free(st);
                return 1;
        }
-       /* now check out all the devices and make sure we can read the superblock */
+       /* now check out all the devices and make sure we can read the
+        * superblock */
        for (d=0 ; d < info.array.raid_disks ; d++) {
                mdu_disk_info_t disk;
                char *dv;
@@ -159,7 +164,7 @@ int Grow_Add_device(char *devname, int fd, char *newdev)
 
                disk.number = d;
                if (ioctl(fd, GET_DISK_INFO, &disk) < 0) {
-                       fprintf(stderr, Name ": cannot get device detail for device %d\n",
+                       pr_err("cannot get device detail for device %d\n",
                                d);
                        close(nfd);
                        free(st);
@@ -167,7 +172,7 @@ int Grow_Add_device(char *devname, int fd, char *newdev)
                }
                dv = map_dev(disk.major, disk.minor, 1);
                if (!dv) {
-                       fprintf(stderr, Name ": cannot find device file for device %d\n",
+                       pr_err("cannot find device file for device %d\n",
                                d);
                        close(nfd);
                        free(st);
@@ -175,14 +180,14 @@ int Grow_Add_device(char *devname, int fd, char *newdev)
                }
                fd2 = dev_open(dv, O_RDWR);
                if (fd2 < 0) {
-                       fprintf(stderr, Name ": cannot open device file %s\n", dv);
+                       pr_err("cannot open device file %s\n", dv);
                        close(nfd);
                        free(st);
                        return 1;
                }
 
                if (st->ss->load_super(st, fd2, NULL)) {
-                       fprintf(stderr, Name ": cannot find super block on %s\n", dv);
+                       pr_err("cannot find super block on %s\n", dv);
                        close(nfd);
                        close(fd2);
                        free(st);
@@ -203,7 +208,7 @@ int Grow_Add_device(char *devname, int fd, char *newdev)
                             0, 0, NULL);
 
        if (st->ss->store_super(st, nfd)) {
-               fprintf(stderr, Name ": Cannot store new superblock on %s\n",
+               pr_err("Cannot store new superblock on %s\n",
                        newdev);
                close(nfd);
                return 1;
@@ -211,7 +216,7 @@ int Grow_Add_device(char *devname, int fd, char *newdev)
        close(nfd);
 
        if (ioctl(fd, ADD_NEW_DISK, &info.disk) != 0) {
-               fprintf(stderr, Name ": Cannot add new disk to this array\n");
+               pr_err("Cannot add new disk to this array\n");
                return 1;
        }
        /* Well, that seems to have worked.
@@ -219,7 +224,7 @@ int Grow_Add_device(char *devname, int fd, char *newdev)
         */
 
        if (ioctl(fd, GET_ARRAY_INFO, &info.array) < 0) {
-               fprintf(stderr, Name ": cannot get array info for %s\n", devname);
+               pr_err("cannot get array info for %s\n", devname);
                return 1;
        }
 
@@ -230,23 +235,23 @@ int Grow_Add_device(char *devname, int fd, char *newdev)
 
                disk.number = d;
                if (ioctl(fd, GET_DISK_INFO, &disk) < 0) {
-                       fprintf(stderr, Name ": cannot get device detail for device %d\n",
+                       pr_err("cannot get device detail for device %d\n",
                                d);
                        return 1;
                }
                dv = map_dev(disk.major, disk.minor, 1);
                if (!dv) {
-                       fprintf(stderr, Name ": cannot find device file for device %d\n",
+                       pr_err("cannot find device file for device %d\n",
                                d);
                        return 1;
                }
                fd2 = dev_open(dv, O_RDWR);
                if (fd2 < 0) {
-                       fprintf(stderr, Name ": cannot open device file %s\n", dv);
+                       pr_err("cannot open device file %s\n", dv);
                        return 1;
                }
                if (st->ss->load_super(st, fd2, NULL)) {
-                       fprintf(stderr, Name ": cannot find super block on %s\n", dv);
+                       pr_err("cannot find super block on %s\n", dv);
                        close(fd);
                        return 1;
                }
@@ -259,7 +264,7 @@ int Grow_Add_device(char *devname, int fd, char *newdev)
                                     0, 0, NULL);
 
                if (st->ss->store_super(st, fd2)) {
-                       fprintf(stderr, Name ": Cannot store new superblock on %s\n", dv);
+                       pr_err("Cannot store new superblock on %s\n", dv);
                        close(fd2);
                        return 1;
                }
@@ -269,7 +274,7 @@ int Grow_Add_device(char *devname, int fd, char *newdev)
        return 0;
 }
 
-int Grow_addbitmap(char *devname, int fd, char *file, int chunk, int delay, int write_behind, int force)
+int Grow_addbitmap(char *devname, int fd, struct context *c, struct shape *s)
 {
        /*
         * First check that array doesn't have a bitmap
@@ -290,7 +295,7 @@ int Grow_addbitmap(char *devname, int fd, char *file, int chunk, int delay, int
 
        if (vers < 9003) {
                major = BITMAP_MAJOR_HOSTENDIAN;
-               fprintf(stderr, Name ": Warning - bitmaps created on this kernel"
+               pr_err("Warning - bitmaps created on this kernel"
                        " are not portable\n"
                        "  between different architectures.  Consider upgrading"
                        " the Linux kernel.\n");
@@ -298,48 +303,48 @@ int Grow_addbitmap(char *devname, int fd, char *file, int chunk, int delay, int
 
        if (ioctl(fd, GET_BITMAP_FILE, &bmf) != 0) {
                if (errno == ENOMEM)
-                       fprintf(stderr, Name ": Memory allocation failure.\n");
+                       pr_err("Memory allocation failure.\n");
                else
-                       fprintf(stderr, Name ": bitmaps not supported by this kernel.\n");
+                       pr_err("bitmaps not supported by this kernel.\n");
                return 1;
        }
        if (bmf.pathname[0]) {
-               if (strcmp(file,"none")==0) {
+               if (strcmp(s->bitmap_file,"none")==0) {
                        if (ioctl(fd, SET_BITMAP_FILE, -1)!= 0) {
-                               fprintf(stderr, Name ": failed to remove bitmap %s\n",
+                               pr_err("failed to remove bitmap %s\n",
                                        bmf.pathname);
                                return 1;
                        }
                        return 0;
                }
-               fprintf(stderr, Name ": %s already has a bitmap (%s)\n",
+               pr_err("%s already has a bitmap (%s)\n",
                        devname, bmf.pathname);
                return 1;
        }
        if (ioctl(fd, GET_ARRAY_INFO, &array) != 0) {
-               fprintf(stderr, Name ": cannot get array status for %s\n", devname);
+               pr_err("cannot get array status for %s\n", devname);
                return 1;
        }
        if (array.state & (1<<MD_SB_BITMAP_PRESENT)) {
-               if (strcmp(file, "none")==0) {
+               if (strcmp(s->bitmap_file, "none")==0) {
                        array.state &= ~(1<<MD_SB_BITMAP_PRESENT);
                        if (ioctl(fd, SET_ARRAY_INFO, &array)!= 0) {
-                               fprintf(stderr, Name ": failed to remove internal bitmap.\n");
+                               pr_err("failed to remove internal bitmap.\n");
                                return 1;
                        }
                        return 0;
                }
-               fprintf(stderr, Name ": Internal bitmap already present on %s\n",
+               pr_err("Internal bitmap already present on %s\n",
                        devname);
                return 1;
        }
 
-       if (strcmp(file, "none") == 0) {
-               fprintf(stderr, Name ": no bitmap found on %s\n", devname);
+       if (strcmp(s->bitmap_file, "none") == 0) {
+               pr_err("no bitmap found on %s\n", devname);
                return 1;
        }
        if (array.level <= 0) {
-               fprintf(stderr, Name ": Bitmaps not meaningful with level %s\n",
+               pr_err("Bitmaps not meaningful with level %s\n",
                        map_num(pers, array.level)?:"of this array");
                return 1;
        }
@@ -353,7 +358,7 @@ int Grow_addbitmap(char *devname, int fd, char *file, int chunk, int delay, int
                bitmapsize = get_component_size(fd);
        }
        if (bitmapsize == 0) {
-               fprintf(stderr, Name ": Cannot reliably determine size of array to create bitmap - sorry.\n");
+               pr_err("Cannot reliably determine size of array to create bitmap - sorry.\n");
                return 1;
        }
 
@@ -364,27 +369,27 @@ int Grow_addbitmap(char *devname, int fd, char *file, int chunk, int delay, int
 
        st = super_by_fd(fd, &subarray);
        if (!st) {
-               fprintf(stderr, Name ": Cannot understand version %d.%d\n",
+               pr_err("Cannot understand version %d.%d\n",
                        array.major_version, array.minor_version);
                return 1;
        }
        if (subarray) {
-               fprintf(stderr, Name ": Cannot add bitmaps to sub-arrays yet\n");
+               pr_err("Cannot add bitmaps to sub-arrays yet\n");
                free(subarray);
                free(st);
                return 1;
        }
-       if (strcmp(file, "internal") == 0) {
+       if (strcmp(s->bitmap_file, "internal") == 0) {
                int rv;
                int d;
                int offset_setable = 0;
                struct mdinfo *mdi;
                if (st->ss->add_internal_bitmap == NULL) {
-                       fprintf(stderr, Name ": Internal bitmaps not supported "
+                       pr_err("Internal bitmaps not supported "
                                "with %s metadata\n", st->ss->name);
                        return 1;
                }
-               mdi = sysfs_read(fd, -1, GET_BITMAP_LOCATION);
+               mdi = sysfs_read(fd, NULL, GET_BITMAP_LOCATION);
                if (mdi)
                        offset_setable = 1;
                for (d=0; d< st->max_devs; d++) {
@@ -406,14 +411,14 @@ int Grow_addbitmap(char *devname, int fd, char *file, int chunk, int delay, int
                                if (st->ss->load_super(st, fd2, NULL)==0) {
                                        if (st->ss->add_internal_bitmap(
                                                    st,
-                                                   &chunk, delay, write_behind,
+                                                   &s->bitmap_chunk, c->delay, s->write_behind,
                                                    bitmapsize, offset_setable,
                                                    major)
                                                )
                                                st->ss->write_bitmap(st, fd2);
                                        else {
-                                               fprintf(stderr, Name ": failed "
-                               "to create internal bitmap - chunksize problem.\n");
+                                               pr_err("failed to create internal bitmap"
+                                                      " - chunksize problem.\n");
                                                close(fd2);
                                                return 1;
                                        }
@@ -423,7 +428,7 @@ int Grow_addbitmap(char *devname, int fd, char *file, int chunk, int delay, int
                }
                if (offset_setable) {
                        st->ss->getinfo_super(st, mdi, NULL);
-                       sysfs_init(mdi, fd, -1);
+                       sysfs_init(mdi, fd, NULL);
                        rv = sysfs_set_num_signed(mdi, NULL, "bitmap/location",
                                                  mdi->bitmap_offset);
                } else {
@@ -432,10 +437,9 @@ int Grow_addbitmap(char *devname, int fd, char *file, int chunk, int delay, int
                }
                if (rv < 0) {
                        if (errno == EBUSY)
-                               fprintf(stderr, Name
-                                       ": Cannot add bitmap while array is"
-                                       " resyncing or reshaping etc.\n");
-                       fprintf(stderr, Name ": failed to set internal bitmap.\n");
+                               pr_err("Cannot add bitmap while array is"
+                                      " resyncing or reshaping etc.\n");
+                       pr_err("failed to set internal bitmap.\n");
                        return 1;
                }
        } else {
@@ -445,7 +449,7 @@ int Grow_addbitmap(char *devname, int fd, char *file, int chunk, int delay, int
                int max_devs = st->max_devs;
 
                /* try to load a superblock */
-               for (d=0; d<max_devs; d++) {
+               for (d = 0; d < max_devs; d++) {
                        mdu_disk_info_t disk;
                        char *dv;
                        int fd2;
@@ -456,7 +460,8 @@ int Grow_addbitmap(char *devname, int fd, char *file, int chunk, int delay, int
                            (disk.state & (1<<MD_DISK_REMOVED)))
                                continue;
                        dv = map_dev(disk.major, disk.minor, 1);
-                       if (!dv) continue;
+                       if (!dv)
+                               continue;
                        fd2 = dev_open(dv, O_RDONLY);
                        if (fd2 >= 0) {
                                if (st->ss->load_super(st, fd2, NULL) == 0) {
@@ -468,26 +473,25 @@ int Grow_addbitmap(char *devname, int fd, char *file, int chunk, int delay, int
                        }
                }
                if (d == max_devs) {
-                       fprintf(stderr, Name ": cannot find UUID for array!\n");
+                       pr_err("cannot find UUID for array!\n");
                        return 1;
                }
-               if (CreateBitmap(file, force, (char*)uuid, chunk,
-                                delay, write_behind, bitmapsize, major)) {
+               if (CreateBitmap(s->bitmap_file, c->force, (char*)uuid, s->bitmap_chunk,
+                                c->delay, s->write_behind, bitmapsize, major)) {
                        return 1;
                }
-               bitmap_fd = open(file, O_RDWR);
+               bitmap_fd = open(s->bitmap_file, O_RDWR);
                if (bitmap_fd < 0) {
-                       fprintf(stderr, Name ": weird: %s cannot be opened\n",
-                               file);
+                       pr_err("weird: %s cannot be opened\n",
+                               s->bitmap_file);
                        return 1;
                }
                if (ioctl(fd, SET_BITMAP_FILE, bitmap_fd) < 0) {
                        int err = errno;
                        if (errno == EBUSY)
-                               fprintf(stderr, Name
-                                       ": Cannot add bitmap while array is"
-                                       " resyncing or reshaping etc.\n");
-                       fprintf(stderr, Name ": Cannot set bitmap file for %s: %s\n",
+                               pr_err("Cannot add bitmap while array is"
+                                      " resyncing or reshaping etc.\n");
+                       pr_err("Cannot set bitmap file for %s: %s\n",
                                devname, strerror(err));
                        return 1;
                }
@@ -526,7 +530,7 @@ static __u32 bsb_csum(char *buf, int len)
 {
        int i;
        int csum = 0;
-       for (i=0; i<len; i++)
+       for (i = 0; i < len; i++)
                csum = (csum<<3) + buf[0];
        return __cpu_to_le32(csum);
 }
@@ -536,13 +540,11 @@ static int check_idle(struct supertype *st)
        /* Check that all member arrays for this container, or the
         * container of this array, are idle
         */
-       int container_dev = (st->container_dev != NoMdDev
-                            ? st->container_dev : st->devnum);
-       char container[40];
+       char *container = (st->container_devnm[0]
+                          ? st->container_devnm : st->devnm);
        struct mdstat_ent *ent, *e;
        int is_idle = 1;
 
-       fmt_devname(container, container_dev);
        ent = mdstat_read(0, 0);
        for (e = ent ; e; e = e->next) {
                if (!is_container_member(e, container))
@@ -558,17 +560,14 @@ static int check_idle(struct supertype *st)
 
 static int freeze_container(struct supertype *st)
 {
-       int container_dev = (st->container_dev != NoMdDev
-                            ? st->container_dev : st->devnum);
-       char container[40];
+       char *container = (st->container_devnm[0]
+                          ? st->container_devnm : st->devnm);
 
        if (!check_idle(st))
                return -1;
 
-       fmt_devname(container, container_dev);
-
        if (block_monitor(container, 1)) {
-               fprintf(stderr, Name ": failed to freeze container\n");
+               pr_err("failed to freeze container\n");
                return -2;
        }
 
@@ -577,11 +576,8 @@ static int freeze_container(struct supertype *st)
 
 static void unfreeze_container(struct supertype *st)
 {
-       int container_dev = (st->container_dev != NoMdDev
-                            ? st->container_dev : st->devnum);
-       char container[40];
-
-       fmt_devname(container, container_dev);
+       char *container = (st->container_devnm[0]
+                          ? st->container_devnm : st->devnm);
 
        unblock_monitor(container, 1);
 }
@@ -597,7 +593,7 @@ static int freeze(struct supertype *st)
        if (st->ss->external)
                return freeze_container(st);
        else {
-               struct mdinfo *sra = sysfs_read(-1, st->devnum, GET_VERSION);
+               struct mdinfo *sra = sysfs_read(-1, st->devnm, GET_VERSION);
                int err;
                char buf[20];
 
@@ -619,12 +615,15 @@ static void unfreeze(struct supertype *st)
        if (st->ss->external)
                return unfreeze_container(st);
        else {
-               struct mdinfo *sra = sysfs_read(-1, st->devnum, GET_VERSION);
+               struct mdinfo *sra = sysfs_read(-1, st->devnm, GET_VERSION);
+               char buf[20];
 
-               if (sra)
+               if (sra &&
+                   sysfs_get_str(sra, NULL, "sync_action", buf, 20) > 0
+                   && strcmp(buf, "frozen\n") == 0) {
+                       printf("unfreeze\n");
                        sysfs_set_str(sra, NULL, "sync_action", "idle");
-               else
-                       fprintf(stderr, Name ": failed to unfreeze array\n");
+               }
                sysfs_free(sra);
        }
 }
@@ -637,18 +636,14 @@ static void wait_reshape(struct mdinfo *sra)
        if (fd < 0)
                return;
 
-       while  (sysfs_fd_get_str(fd, action, 20) > 0 &&
-               strncmp(action, "reshape", 7) == 0) {
-               fd_set rfds;
-               FD_ZERO(&rfds);
-               FD_SET(fd, &rfds);
-               select(fd+1, NULL, NULL, &rfds, NULL);
-       }
+       while (sysfs_fd_get_str(fd, action, 20) > 0 &&
+              strncmp(action, "reshape", 7) == 0)
+               sysfs_wait(fd, NULL);
        close(fd);
 }
 
-static int reshape_super(struct supertype *st, long long size, int level,
-                        int layout, int chunksize, int raid_disks,
+static int reshape_super(struct supertype *st, unsigned long long size,
+                        int level, int layout, int chunksize, int raid_disks,
                         int delta_disks, char *backup_file, char *dev,
                         int direction, int verbose)
 {
@@ -657,7 +652,7 @@ static int reshape_super(struct supertype *st, long long size, int level,
                return 0;
        if (!st->ss->reshape_super ||
            !st->ss->manage_reshape) {
-               fprintf(stderr, Name ": %s metadata does not support reshape\n",
+               pr_err("%s metadata does not support reshape\n",
                        st->ss->name);
                return 1;
        }
@@ -744,7 +739,8 @@ void abort_reshape(struct mdinfo *sra)
        sysfs_set_num(sra, NULL, "suspend_hi", 0);
        sysfs_set_num(sra, NULL, "suspend_lo", 0);
        sysfs_set_num(sra, NULL, "sync_min", 0);
-       sysfs_set_str(sra, NULL, "sync_max", "max");
+       // It isn't safe to reset sync_max as we aren't monitoring.
+       // Array really should be stopped at this point.
 }
 
 int remove_disks_for_takeover(struct supertype *st,
@@ -850,6 +846,7 @@ int reshape_prepare_fdlist(char *devname,
        int d = 0;
        struct mdinfo *sd;
 
+       enable_fds(nrdisks);
        for (d = 0; d <= nrdisks; d++)
                fdlist[d] = -1;
        d = raid_disks;
@@ -863,9 +860,8 @@ int reshape_prepare_fdlist(char *devname,
                                = dev_open(dn, O_RDONLY);
                        offsets[sd->disk.raid_disk] = sd->data_offset*512;
                        if (fdlist[sd->disk.raid_disk] < 0) {
-                               fprintf(stderr,
-                                       Name ": %s: cannot open component %s\n",
-                                       devname, dn ? dn : "-unknown-");
+                               pr_err("%s: cannot open component %s\n",
+                                      devname, dn ? dn : "-unknown-");
                                d = -1;
                                goto release;
                        }
@@ -876,7 +872,7 @@ int reshape_prepare_fdlist(char *devname,
                                fdlist[d] = dev_open(dn, O_RDWR);
                                offsets[d] = (sd->data_offset + sra->component_size - blocks - 8)*512;
                                if (fdlist[d] < 0) {
-                                       fprintf(stderr, Name ": %s: cannot open component %s\n",
+                                       pr_err("%s: cannot open component %s\n",
                                                devname, dn ? dn : "-unknown-");
                                        d = -1;
                                        goto release;
@@ -894,6 +890,7 @@ int reshape_open_backup_file(char *backup_file,
                             long blocks,
                             int *fdlist,
                             unsigned long long *offsets,
+                            char *sys_name,
                             int restart)
 {
        /* Return 1 on success, 0 on any form of failure */
@@ -907,7 +904,7 @@ int reshape_open_backup_file(char *backup_file,
                       S_IRUSR | S_IWUSR);
        *offsets = 8 * 512;
        if (*fdlist < 0) {
-               fprintf(stderr, Name ": %s: cannot create backup file %s: %s\n",
+               pr_err("%s: cannot create backup file %s: %s\n",
                        devname, backup_file, strerror(errno));
                return 0;
        }
@@ -920,7 +917,7 @@ int reshape_open_backup_file(char *backup_file,
        dev = stb.st_dev;
        fstat(fd, &stb);
        if (stb.st_rdev == dev) {
-               fprintf(stderr, Name ": backup file must NOT be"
+               pr_err("backup file must NOT be"
                        " on the array being reshaped.\n");
                close(*fdlist);
                return 0;
@@ -929,18 +926,26 @@ int reshape_open_backup_file(char *backup_file,
        memset(buf, 0, 512);
        for (i=0; i < blocks + 8 ; i++) {
                if (write(*fdlist, buf, 512) != 512) {
-                       fprintf(stderr, Name ": %s: cannot create"
+                       pr_err("%s: cannot create"
                                " backup file %s: %s\n",
                                devname, backup_file, strerror(errno));
                        return 0;
                }
        }
        if (fsync(*fdlist) != 0) {
-               fprintf(stderr, Name ": %s: cannot create backup file %s: %s\n",
+               pr_err("%s: cannot create backup file %s: %s\n",
                        devname, backup_file, strerror(errno));
                return 0;
        }
 
+       if (!restart && strncmp(backup_file, MAP_DIR, strlen(MAP_DIR)) != 0) {
+               char *bu = make_backup(sys_name);
+               if (symlink(backup_file, bu))
+                       pr_err("Recording backup file in " MAP_DIR "failed: %s\n",
+                              strerror(errno));
+               free(bu);
+       }
+
        return 1;
 }
 
@@ -956,19 +961,14 @@ unsigned long compute_backup_blocks(int nchunk, int ochunk,
        a = (ochunk/512) * odata;
        b = (nchunk/512) * ndata;
        /* Find GCD */
-       while (a != b) {
-               if (a < b)
-                       b -= a;
-               if (b < a)
-                       a -= b;
-       }
+       a = GCD(a, b);
        /* LCM == product / GCD */
        blocks = (ochunk/512) * (nchunk/512) * odata * ndata / a;
 
        return blocks;
 }
 
-char *analyse_change(struct mdinfo *info, struct reshape *re)
+char *analyse_change(char *devname, struct mdinfo *info, struct reshape *re)
 {
        /* Based on the current array state in info->array and
         * the changes in info->new_* etc, determine:
@@ -985,12 +985,16 @@ char *analyse_change(struct mdinfo *info, struct reshape *re)
         * This can be called as part of starting a reshape, or
         * when assembling an array that is undergoing reshape.
         */
+       int near, far, offset, copies;
        int new_disks;
+       int old_chunk, new_chunk;
        /* delta_parity records change in number of devices
         * caused by level change
         */
        int delta_parity = 0;
 
+       memset(re, 0, sizeof(*re));
+
        /* If a new level not explicitly given, we assume no-change */
        if (info->new_level == UnSet)
                info->new_level = info->array.level;
@@ -1005,9 +1009,16 @@ char *analyse_change(struct mdinfo *info, struct reshape *re)
                        /* chunk size is meaningful, must divide component_size
                         * evenly
                         */
-                       if (info->component_size % (info->new_chunk/512))
-                               return "New chunk size does not"
-                                       " divide component size";
+                       if (info->component_size % (info->new_chunk/512)) {
+                               unsigned long long shrink = info->component_size;
+                               shrink &= ~(unsigned long long)(info->new_chunk/512-1);
+                               pr_err("New chunk size (%dK) does not evenly divide device size (%lluk)\n",
+                                      info->new_chunk/1024, info->component_size/2);
+                               pr_err("After shrinking any filesystem, \"mdadm --grow %s --size %llu\"\n",
+                                      devname, shrink/2);
+                               pr_err("will shrink the array so the given chunk size would work.\n");
+                               return "";
+                       }
                        break;
                default:
                        return "chunk size not meaningful for this level";
@@ -1017,7 +1028,12 @@ char *analyse_change(struct mdinfo *info, struct reshape *re)
 
        switch (info->array.level) {
        default:
-               return "Cannot understand this RAID level";
+               return "No reshape is possibly for this RAID level";
+       case LEVEL_LINEAR:
+               if (info->delta_disks != UnSet)
+                       return "Only --add is supported for LINEAR, setting --raid-disks is not needed";
+               else
+                       return "Only --add is supported for LINEAR, other --grow options are not meaningful";
        case 1:
                /* RAID1 can convert to RAID1 with different disks, or
                 * raid5 with 2 disks, or
@@ -1035,9 +1051,6 @@ char *analyse_change(struct mdinfo *info, struct reshape *re)
                        re->level = 0;
                        re->before.data_disks = 1;
                        re->after.data_disks = 1;
-                       re->before.layout = 0;
-                       re->backup_blocks = 0;
-                       re->parity = 0;
                        return NULL;
                }
                if (info->new_level == 1) {
@@ -1045,8 +1058,6 @@ char *analyse_change(struct mdinfo *info, struct reshape *re)
                                /* Don't know what to do */
                                return "no change requested for Growing RAID1";
                        re->level = 1;
-                       re->backup_blocks = 0;
-                       re->parity = 0;
                        return NULL;
                }
                if (info->array.raid_disks == 2 &&
@@ -1072,38 +1083,94 @@ char *analyse_change(struct mdinfo *info, struct reshape *re)
                return "Impossibly level change request for RAID1";
 
        case 10:
-               /* RAID10 can only be converted from near mode to
-                * RAID0 by removing some devices
+               /* RAID10 can be converted from near mode to
+                * RAID0 by removing some devices.
+                * It can also be reshaped if the kernel supports
+                * new_data_offset.
                 */
-               if ((info->array.layout & ~0xff) != 0x100)
-                       return "Cannot Grow RAID10 with far/offset layout";
-               /* number of devices must be multiple of number of copies */
-               if (info->array.raid_disks % (info->array.layout & 0xff))
-                       return "RAID10 layout too complex for Grow operation";
+               switch (info->new_level) {
+               case 0:
+                       if ((info->array.layout & ~0xff) != 0x100)
+                               return "Cannot Grow RAID10 with far/offset layout";
+                       /* number of devices must be multiple of number of copies */
+                       if (info->array.raid_disks % (info->array.layout & 0xff))
+                               return "RAID10 layout too complex for Grow operation";
+
+                       new_disks = (info->array.raid_disks
+                                    / (info->array.layout & 0xff));
+                       if (info->delta_disks == UnSet)
+                               info->delta_disks = (new_disks
+                                                    - info->array.raid_disks);
 
-               if (info->new_level != 0)
-                       return "RAID10 can only be changed to RAID0";
-               new_disks = (info->array.raid_disks
-                            / (info->array.layout & 0xff));
-               if (info->delta_disks == UnSet)
-                       info->delta_disks = (new_disks
-                                            - info->array.raid_disks);
-
-               if (info->delta_disks != new_disks - info->array.raid_disks)
-                       return "New number of raid-devices impossible for RAID10";
-               if (info->new_chunk &&
-                   info->new_chunk != info->array.chunk_size)
-                       return "Cannot change chunk-size with RAID10 Grow";
-
-               /* looks good */
-               re->level = 0;
-               re->parity = 0;
-               re->before.data_disks = new_disks;
-               re->after.data_disks = re->before.data_disks;
-               re->before.layout = 0;
-               re->backup_blocks = 0;
-               return NULL;
+                       if (info->delta_disks != new_disks - info->array.raid_disks)
+                               return "New number of raid-devices impossible for RAID10";
+                       if (info->new_chunk &&
+                           info->new_chunk != info->array.chunk_size)
+                               return "Cannot change chunk-size with RAID10 Grow";
 
+                       /* looks good */
+                       re->level = 0;
+                       re->before.data_disks = new_disks;
+                       re->after.data_disks = re->before.data_disks;
+                       return NULL;
+
+               case 10:
+                       near = info->array.layout & 0xff;
+                       far = (info->array.layout >> 8) & 0xff;
+                       offset = info->array.layout & 0x10000;
+                       if (far > 1 && !offset)
+                               return "Cannot reshape RAID10 in far-mode";
+                       copies = near * far;
+
+                       old_chunk = info->array.chunk_size * far;
+
+                       if (info->new_layout == UnSet)
+                               info->new_layout = info->array.layout;
+                       else {
+                               near = info->new_layout & 0xff;
+                               far = (info->new_layout >> 8) & 0xff;
+                               offset = info->new_layout & 0x10000;
+                               if (far > 1 && !offset)
+                                       return "Cannot reshape RAID10 to far-mode";
+                               if (near * far != copies)
+                                       return "Cannot change number of copies"
+                                               " when reshaping RAID10";
+                       }
+                       if (info->delta_disks == UnSet)
+                               info->delta_disks = 0;
+                       new_disks = (info->array.raid_disks +
+                                    info->delta_disks);
+
+                       new_chunk = info->new_chunk * far;
+
+                       re->level = 10;
+                       re->before.layout = info->array.layout;
+                       re->before.data_disks = info->array.raid_disks;
+                       re->after.layout = info->new_layout;
+                       re->after.data_disks = new_disks;
+                       /* For RAID10 we don't do backup but do allow reshape,
+                        * so set backup_blocks to INVALID_SECTORS rather than
+                        * zero.
+                        * And there is no need to synchronise stripes on both
+                        * 'old' and  'new'.  So the important
+                        * number is the minimum data_offset difference
+                        * which is the larger of (offset copies * chunk).
+                        */
+                       re->backup_blocks = INVALID_SECTORS;
+                       re->min_offset_change = max(old_chunk, new_chunk) / 512;
+                       if (new_disks < re->before.data_disks &&
+                           info->space_after < re->min_offset_change)
+                               /* Reduce component size by one chunk */
+                               re->new_size = (info->component_size -
+                                               re->min_offset_change);
+                       else
+                               re->new_size = info->component_size;
+                       re->new_size = re->new_size * new_disks / copies;
+                       return NULL;
+
+               default:
+                       return "RAID10 can only be changed to RAID0";
+               }
        case 0:
                /* RAID0 can be converted to RAID10, or to RAID456 */
                if (info->new_level == 10) {
@@ -1134,12 +1201,10 @@ char *analyse_change(struct mdinfo *info, struct reshape *re)
                                return "Cannot change chunk-size with RAID0->RAID10";
                        /* looks good */
                        re->level = 10;
-                       re->parity = 0;
                        re->before.data_disks = (info->array.raid_disks +
                                                 info->delta_disks);
                        re->after.data_disks = re->before.data_disks;
                        re->before.layout = info->new_layout;
-                       re->backup_blocks = 0;
                        return NULL;
                }
 
@@ -1157,11 +1222,15 @@ char *analyse_change(struct mdinfo *info, struct reshape *re)
                        delta_parity = 1;
                        re->level = 5;
                        re->before.layout = ALGORITHM_PARITY_N;
+                       if (info->new_layout == UnSet)
+                               info->new_layout = map_name(r5layout, "default");
                        break;
                case 6:
                        delta_parity = 2;
                        re->level = 6;
                        re->before.layout = ALGORITHM_PARITY_N;
+                       if (info->new_layout == UnSet)
+                               info->new_layout = map_name(r6layout, "default");
                        break;
                default:
                        return "Impossible level change requested";
@@ -1221,7 +1290,8 @@ char *analyse_change(struct mdinfo *info, struct reshape *re)
                                return "Cannot set raid_disk when "
                                        "converting RAID5->RAID1";
                        re->level = 1;
-                       break;
+                       info->new_chunk = 0;
+                       return NULL;
                default:
                        return "Impossible level change requested";
                }
@@ -1259,9 +1329,12 @@ char *analyse_change(struct mdinfo *info, struct reshape *re)
 
                switch (re->level) {
                case 4:
-                       re->after.layout = 0 ; break;
+                       re->before.layout = 0;
+                       re->after.layout = 0;
+                       break;
                case 5:
-                       re->after.layout = ALGORITHM_PARITY_N; break;
+                       re->after.layout = ALGORITHM_PARITY_N;
+                       break;
                }
                break;
 
@@ -1272,9 +1345,11 @@ char *analyse_change(struct mdinfo *info, struct reshape *re)
 
                switch (re->level) {
                case 4:
-                       re->after.layout = 0 ; break;
+                       re->after.layout = 0;
+                       break;
                case 5:
-                       re->after.layout = ALGORITHM_PARITY_N; break;
+                       re->after.layout = ALGORITHM_PARITY_N;
+                       break;
                }
                break;
 
@@ -1346,25 +1421,31 @@ char *analyse_change(struct mdinfo *info, struct reshape *re)
                                + info->delta_disks
                                - delta_parity);
        switch (re->level) {
-       case 6: re->parity = 2; break;
+       case 6: re->parity = 2;
+               break;
        case 4:
-       case 5: re->parity = 1; break;
-       default: re->parity = 0; break;
+       case 5: re->parity = 1;
+               break;
+       default: re->parity = 0;
+               break;
        }
        /* So we have a restripe operation, we need to calculate the number
         * of blocks per reshape operation.
         */
+       re->new_size = info->component_size * re->before.data_disks;
        if (info->new_chunk == 0)
                info->new_chunk = info->array.chunk_size;
        if (re->after.data_disks == re->before.data_disks &&
            re->after.layout == re->before.layout &&
            info->new_chunk == info->array.chunk_size) {
-               /* Nothing to change */
+               /* Nothing to change, can change level immediately. */
+               re->level = info->new_level;
                re->backup_blocks = 0;
                return NULL;
        }
        if (re->after.data_disks == 1 && re->before.data_disks == 1) {
                /* chunk and layout changes make no difference */
+               re->level = info->new_level;
                re->backup_blocks = 0;
                return NULL;
        }
@@ -1381,6 +1462,7 @@ char *analyse_change(struct mdinfo *info, struct reshape *re)
                info->new_chunk, info->array.chunk_size,
                re->after.data_disks,
                re->before.data_disks);
+       re->min_offset_change = re->backup_blocks / re->before.data_disks;
 
        re->new_size = info->component_size * re->after.data_disks;
        return NULL;
@@ -1414,8 +1496,8 @@ static int set_array_size(struct supertype *st, struct mdinfo *sra,
                                ret_val = 0;
                                dprintf("Array size changed");
                        }
-                       dprintf(" from %llu to %llu.\n",
-                               current_size, new_size);
+                       dprintf_cont(" from %llu to %llu.\n",
+                                    current_size, new_size);
                }
                sysfs_free(info);
        } else
@@ -1427,21 +1509,21 @@ static int set_array_size(struct supertype *st, struct mdinfo *sra,
 static int reshape_array(char *container, int fd, char *devname,
                         struct supertype *st, struct mdinfo *info,
                         int force, struct mddev_dev *devlist,
-                        char *backup_file, int quiet, int forked,
+                        unsigned long long data_offset,
+                        char *backup_file, int verbose, int forked,
                         int restart, int freeze_reshape);
 static int reshape_container(char *container, char *devname,
                             int mdfd,
                             struct supertype *st,
                             struct mdinfo *info,
                             int force,
-                            char *backup_file,
-                            int quiet, int restart, int freeze_reshape);
+                            char *backup_file, int verbose,
+                            int forked, int restart, int freeze_reshape);
 
-int Grow_reshape(char *devname, int fd, int quiet, char *backup_file,
-                long long size,
-                int level, char *layout_str, int chunksize, int raid_disks,
+int Grow_reshape(char *devname, int fd,
                 struct mddev_dev *devlist,
-                int assume_clean, int force)
+                unsigned long long data_offset,
+                struct context *c, struct shape *s)
 {
        /* Make some changes in the shape of an array.
         * The kernel must support the change.
@@ -1468,7 +1550,6 @@ int Grow_reshape(char *devname, int fd, int quiet, char *backup_file,
        int frozen;
        int changed = 0;
        char *container = NULL;
-       char container_buf[20];
        int cfd = -1;
 
        struct mddev_dev *dv;
@@ -1478,35 +1559,40 @@ int Grow_reshape(char *devname, int fd, int quiet, char *backup_file,
        struct mdinfo *sra;
 
        if (ioctl(fd, GET_ARRAY_INFO, &array) < 0) {
-               fprintf(stderr, Name ": %s is not an active md array - aborting\n",
+               pr_err("%s is not an active md array - aborting\n",
                        devname);
                return 1;
        }
+       if (data_offset != INVALID_SECTORS && array.level != 10
+           && (array.level < 4 || array.level > 6)) {
+               pr_err("--grow --data-offset not yet supported\n");
+               return 1;
+       }
 
-       if (size >= 0 &&
-           (chunksize || level!= UnSet || layout_str || raid_disks)) {
-               fprintf(stderr, Name ": cannot change component size at the same time "
+       if (s->size > 0 &&
+           (s->chunk || s->level!= UnSet || s->layout_str || s->raiddisks)) {
+               pr_err("cannot change component size at the same time "
                        "as other changes.\n"
                        "   Change size first, then check data is intact before "
                        "making other changes.\n");
                return 1;
        }
 
-       if (raid_disks && raid_disks < array.raid_disks && array.level > 1 &&
+       if (s->raiddisks && s->raiddisks < array.raid_disks && array.level > 1 &&
            get_linux_version() < 2006032 &&
            !check_env("MDADM_FORCE_FEWER")) {
-               fprintf(stderr, Name ": reducing the number of devices is not safe before Linux 2.6.32\n"
+               pr_err("reducing the number of devices is not safe before Linux 2.6.32\n"
                        "       Please use a newer kernel\n");
                return 1;
        }
 
        st = super_by_fd(fd, &subarray);
        if (!st) {
-               fprintf(stderr, Name ": Unable to determine metadata format for %s\n", devname);
+               pr_err("Unable to determine metadata format for %s\n", devname);
                return 1;
        }
-       if (raid_disks > st->max_devs) {
-               fprintf(stderr, Name ": Cannot increase raid-disks on this array"
+       if (s->raiddisks > st->max_devs) {
+               pr_err("Cannot increase raid-disks on this array"
                        " beyond %d\n", st->max_devs);
                return 1;
        }
@@ -1516,32 +1602,28 @@ int Grow_reshape(char *devname, int fd, int quiet, char *backup_file,
         * pre-requisite spare devices (mdmon owns final validation)
         */
        if (st->ss->external) {
-               int container_dev;
                int rv;
 
                if (subarray) {
-                       container_dev = st->container_dev;
-                       cfd = open_dev_excl(st->container_dev);
+                       container = st->container_devnm;
+                       cfd = open_dev_excl(st->container_devnm);
                } else {
-                       container_dev = st->devnum;
+                       container = st->devnm;
                        close(fd);
-                       cfd = open_dev_excl(st->devnum);
+                       cfd = open_dev_excl(st->devnm);
                        fd = cfd;
                }
                if (cfd < 0) {
-                       fprintf(stderr, Name ": Unable to open container for %s\n",
+                       pr_err("Unable to open container for %s\n",
                                devname);
                        free(subarray);
                        return 1;
                }
 
-               fmt_devname(container_buf, container_dev);
-               container = container_buf;
-
                rv = st->ss->load_container(st, cfd, NULL);
 
                if (rv) {
-                       fprintf(stderr, Name ": Cannot read superblock for %s\n",
+                       pr_err("Cannot read superblock for %s\n",
                                devname);
                        free(subarray);
                        return 1;
@@ -1565,11 +1647,10 @@ int Grow_reshape(char *devname, int fd, int quiet, char *backup_file,
                                    & (1<<MD_SB_BLOCK_CONTAINER_RESHAPE))
                                        allow_reshape = 0;
                                if (!allow_reshape) {
-                                       fprintf(stderr, Name
-                                               " cannot reshape arrays in"
-                                               " container with unsupported"
-                                               " metadata: %s(%s)\n",
-                                               devname, container_buf);
+                                       pr_err("cannot reshape arrays in"
+                                              " container with unsupported"
+                                              " metadata: %s(%s)\n",
+                                              devname, container);
                                        sysfs_free(cc);
                                        free(subarray);
                                        return 1;
@@ -1577,27 +1658,26 @@ int Grow_reshape(char *devname, int fd, int quiet, char *backup_file,
                        }
                        sysfs_free(cc);
                }
-               if (mdmon_running(container_dev))
+               if (mdmon_running(container))
                        st->update_tail = &st->updates;
        }
 
        added_disks = 0;
        for (dv = devlist; dv; dv = dv->next)
                added_disks++;
-       if (raid_disks > array.raid_disks &&
-           array.spare_disks +added_disks < (raid_disks - array.raid_disks) &&
-           !force) {
-               fprintf(stderr,
-                       Name ": Need %d spare%s to avoid degraded array,"
-                       " and only have %d.\n"
-                       "       Use --force to over-ride this check.\n",
-                       raid_disks - array.raid_disks,
-                       raid_disks - array.raid_disks == 1 ? "" : "s",
-                       array.spare_disks + added_disks);
+       if (s->raiddisks > array.raid_disks &&
+           array.spare_disks +added_disks < (s->raiddisks - array.raid_disks) &&
+           !c->force) {
+               pr_err("Need %d spare%s to avoid degraded array,"
+                      " and only have %d.\n"
+                      "       Use --force to over-ride this check.\n",
+                      s->raiddisks - array.raid_disks,
+                      s->raiddisks - array.raid_disks == 1 ? "" : "s",
+                      array.spare_disks + added_disks);
                return 1;
        }
 
-       sra = sysfs_read(fd, 0, GET_LEVEL | GET_DISKS | GET_DEVS
+       sra = sysfs_read(fd, NULL, GET_LEVEL | GET_DISKS | GET_DEVS
                         | GET_STATE | GET_VERSION);
        if (sra) {
                if (st->ss->external && subarray == NULL) {
@@ -1605,7 +1685,7 @@ int Grow_reshape(char *devname, int fd, int quiet, char *backup_file,
                        sra->array.level = LEVEL_CONTAINER;
                }
        } else {
-               fprintf(stderr, Name ": failed to read sysfs parameters for %s\n",
+               pr_err("failed to read sysfs parameters for %s\n",
                        devname);
                return 1;
        }
@@ -1615,24 +1695,30 @@ int Grow_reshape(char *devname, int fd, int quiet, char *backup_file,
                sysfs_free(sra);
                return 1;
        } else if (frozen < 0) {
-               fprintf(stderr, Name ": %s is performing resync/recovery and cannot"
+               pr_err("%s is performing resync/recovery and cannot"
                        " be reshaped\n", devname);
                sysfs_free(sra);
                return 1;
        }
 
        /* ========= set size =============== */
-       if (size >= 0 && (size == 0 || size != array.size)) {
-               long long orig_size = get_component_size(fd)/2;
-               long long min_csize;
+       if (s->size > 0 && (s->size == MAX_SIZE || s->size != (unsigned)array.size)) {
+               unsigned long long orig_size = get_component_size(fd)/2;
+               unsigned long long min_csize;
                struct mdinfo *mdi;
                int raid0_takeover = 0;
 
                if (orig_size == 0)
-                       orig_size = array.size;
+                       orig_size = (unsigned) array.size;
+
+               if (orig_size == 0) {
+                       pr_err("Cannot set device size in this type of array.\n");
+                       rv = 1;
+                       goto release;
+               }
 
-               if (reshape_super(st, size, UnSet, UnSet, 0, 0, UnSet, NULL,
-                                 devname, APPLY_METADATA_CHANGES, !quiet)) {
+               if (reshape_super(st, s->size, UnSet, UnSet, 0, 0, UnSet, NULL,
+                                 devname, APPLY_METADATA_CHANGES, c->verbose > 0)) {
                        rv = 1;
                        goto release;
                }
@@ -1654,7 +1740,7 @@ int Grow_reshape(char *devname, int fd, int quiet, char *backup_file,
                                dprintf("Metadata size correction from %llu to "
                                        "%llu (%llu)\n", orig_size, new_size,
                                        new_size * data_disks);
-                               size = new_size;
+                               s->size = new_size;
                                sysfs_free(sizeinfo);
                        }
                }
@@ -1667,7 +1753,8 @@ int Grow_reshape(char *devname, int fd, int quiet, char *backup_file,
                min_csize = 0;
                rv = 0;
                for (mdi = sra->devs; mdi; mdi = mdi->next) {
-                       if (sysfs_set_num(sra, mdi, "size", size) < 0) {
+                       if (sysfs_set_num(sra, mdi, "size",
+                                         s->size == MAX_SIZE ? 0 : s->size) < 0) {
                                /* Probably kernel refusing to let us
                                 * reduce the size - not an error.
                                 */
@@ -1682,29 +1769,29 @@ int Grow_reshape(char *devname, int fd, int quiet, char *backup_file,
                                        if (csize >= 2ULL*1024*1024*1024)
                                                csize = 2ULL*1024*1024*1024;
                                        if ((min_csize == 0 || (min_csize
-                                                               > (long long)csize)))
+                                                               > csize)))
                                                min_csize = csize;
                                }
                        }
                }
                if (rv) {
-                       fprintf(stderr, Name ": Cannot set size on "
+                       pr_err("Cannot set size on "
                                "array members.\n");
                        goto size_change_error;
                }
-               if (min_csize && size > min_csize) {
-                       fprintf(stderr, Name ": Cannot safely make this array "
+               if (min_csize && s->size > min_csize) {
+                       pr_err("Cannot safely make this array "
                                "use more than 2TB per device on this kernel.\n");
                        rv = 1;
                        goto size_change_error;
                }
-               if (min_csize && size == 0) {
+               if (min_csize && s->size == MAX_SIZE) {
                        /* Don't let the kernel choose a size - it will get
                         * it wrong
                         */
-                       fprintf(stderr, Name ": Limited v0.90 array to "
-                               "2TB per device\n");
-                       size = min_csize;
+                       pr_err("Limited v0.90 array to "
+                              "2TB per device\n");
+                       s->size = min_csize;
                }
                if (st->ss->external) {
                        if (sra->array.level == 0) {
@@ -1720,22 +1807,24 @@ int Grow_reshape(char *devname, int fd, int quiet, char *backup_file,
                        }
                        /* make sure mdmon is
                         * aware of the new level */
-                       if (!mdmon_running(st->container_dev))
-                               start_mdmon(st->container_dev);
+                       if (!mdmon_running(st->container_devnm))
+                               start_mdmon(st->container_devnm);
                        ping_monitor(container);
-                       if (mdmon_running(st->container_dev) &&
+                       if (mdmon_running(st->container_devnm) &&
                                        st->update_tail == NULL)
                                st->update_tail = &st->updates;
                }
 
-               array.size = size;
-               if (array.size != size) {
+               if (s->size == MAX_SIZE)
+                       s->size = 0;
+               array.size = s->size;
+               if (s->size & ~INT32_MAX) {
                        /* got truncated to 32bit, write to
                         * component_size instead
                         */
                        if (sra)
                                rv = sysfs_set_num(sra, NULL,
-                                                  "component_size", size);
+                                                  "component_size", s->size);
                        else
                                rv = -1;
                } else {
@@ -1766,53 +1855,54 @@ size_change_error:
                        if (reshape_super(st, orig_size, UnSet, UnSet, 0, 0,
                                          UnSet, NULL, devname,
                                          ROLLBACK_METADATA_CHANGES,
-                                         !quiet) == 0)
+                                         c->verbose) == 0)
                                sync_metadata(st);
-                       fprintf(stderr, Name ": Cannot set device size for %s: %s\n",
+                       pr_err("Cannot set device size for %s: %s\n",
                                devname, strerror(err));
                        if (err == EBUSY &&
                            (array.state & (1<<MD_SB_BITMAP_PRESENT)))
-                               fprintf(stderr, "       Bitmap must be removed before size can be changed\n");
+                               cont_err("Bitmap must be removed before size can be changed\n");
                        rv = 1;
                        goto release;
                }
-               if (assume_clean) {
-                       /* This will fail on kernels newer than 3.0 unless
+               if (s->assume_clean) {
+                       /* This will fail on kernels older than 3.0 unless
                         * a backport has been arranged.
                         */
                        if (sra == NULL ||
                            sysfs_set_str(sra, NULL, "resync_start", "none") < 0)
-                               fprintf(stderr, Name ": --assume-clean not support with --grow on this kernel\n");
+                               pr_err("--assume-clean not supported with --grow on this kernel\n");
                }
                ioctl(fd, GET_ARRAY_INFO, &array);
-               size = get_component_size(fd)/2;
-               if (size == 0)
-                       size = array.size;
-               if (!quiet) {
-                       if (size == orig_size)
-                               fprintf(stderr, Name ": component size of %s "
+               s->size = get_component_size(fd)/2;
+               if (s->size == 0)
+                       s->size = array.size;
+               if (c->verbose >= 0) {
+                       if (s->size == orig_size)
+                               pr_err("component size of %s "
                                        "unchanged at %lluK\n",
-                                       devname, size);
+                                       devname, s->size);
                        else
-                               fprintf(stderr, Name ": component size of %s "
+                               pr_err("component size of %s "
                                        "has been set to %lluK\n",
-                                       devname, size);
+                                       devname, s->size);
                }
                changed = 1;
        } else if (array.level != LEVEL_CONTAINER) {
-               size = get_component_size(fd)/2;
-               if (size == 0)
-                       size = array.size;
+               s->size = get_component_size(fd)/2;
+               if (s->size == 0)
+                       s->size = array.size;
        }
 
        /* See if there is anything else to do */
-       if ((level == UnSet || level == array.level) &&
-           (layout_str == NULL) &&
-           (chunksize == 0 || chunksize == array.chunk_size) &&
-           (raid_disks == 0 || raid_disks == array.raid_disks)) {
+       if ((s->level == UnSet || s->level == array.level) &&
+           (s->layout_str == NULL) &&
+           (s->chunk == 0 || s->chunk == array.chunk_size) &&
+           data_offset == INVALID_SECTORS &&
+           (s->raiddisks == 0 || s->raiddisks == array.raid_disks)) {
                /* Nothing more to do */
-               if (!changed && !quiet)
-                       fprintf(stderr, Name ": %s: no change requested\n",
+               if (!changed && c->verbose >= 0)
+                       pr_err("%s: no change requested\n",
                                devname);
                goto release;
        }
@@ -1823,13 +1913,13 @@ size_change_error:
         *      - far_copies == 1
         *      - near_copies == 2
         */
-       if ((level == 0 && array.level == 10 && sra &&
+       if ((s->level == 0 && array.level == 10 && sra &&
             array.layout == ((1 << 8) + 2) && !(array.raid_disks & 1)) ||
-           (level == 0 && array.level == 1 && sra)) {
+           (s->level == 0 && array.level == 1 && sra)) {
                int err;
                err = remove_disks_for_takeover(st, sra, array.layout);
                if (err) {
-                       dprintf(Name": Array cannot be reshaped\n");
+                       dprintf("Array cannot be reshaped\n");
                        if (cfd > -1)
                                close(cfd);
                        rv = 1;
@@ -1845,36 +1935,34 @@ size_change_error:
 
        memset(&info, 0, sizeof(info));
        info.array = array;
-       sysfs_init(&info, fd, NoMdDev);
+       sysfs_init(&info, fd, NULL);
        strcpy(info.text_version, sra->text_version);
-       info.component_size = size*2;
-       info.new_level = level;
-       info.new_chunk = chunksize * 1024;
+       info.component_size = s->size*2;
+       info.new_level = s->level;
+       info.new_chunk = s->chunk * 1024;
        if (info.array.level == LEVEL_CONTAINER) {
                info.delta_disks = UnSet;
-               info.array.raid_disks = raid_disks;
-       } else if (raid_disks)
-               info.delta_disks = raid_disks - info.array.raid_disks;
+               info.array.raid_disks = s->raiddisks;
+       } else if (s->raiddisks)
+               info.delta_disks = s->raiddisks - info.array.raid_disks;
        else
                info.delta_disks = UnSet;
-       if (layout_str == NULL) {
+       if (s->layout_str == NULL) {
                info.new_layout = UnSet;
                if (info.array.level == 6 &&
                    (info.new_level == 6 || info.new_level == UnSet) &&
                    info.array.layout >= 16) {
-                       fprintf(stderr, Name
-                               ": %s has a non-standard layout.  If you"
-                               " wish to preserve this\n"
-                               "      during the reshape, please specify"
-                               " --layout=preserve\n"
-                               "      If you want to change it, specify a"
-                               " layout or use --layout=normalise\n",
-                               devname);
+                       pr_err("%s has a non-standard layout.  If you"
+                              " wish to preserve this\n", devname);
+                       cont_err("during the reshape, please specify"
+                                " --layout=preserve\n");
+                       cont_err("If you want to change it, specify a"
+                                " layout or use --layout=normalise\n");
                        rv = 1;
                        goto release;
                }
-       } else if (strcmp(layout_str, "normalise") == 0 ||
-                  strcmp(layout_str, "normalize") == 0) {
+       } else if (strcmp(s->layout_str, "normalise") == 0 ||
+                  strcmp(s->layout_str, "normalize") == 0) {
                /* If we have a -6 RAID6 layout, remove the '-6'. */
                info.new_layout = UnSet;
                if (info.array.level == 6 && info.new_level == UnSet) {
@@ -1886,13 +1974,12 @@ size_change_error:
                                info.new_layout = map_name(r6layout, l);
                        }
                } else {
-                       fprintf(stderr, Name
-                               ": %s is only meaningful when reshaping"
-                               " a RAID6 array.\n", layout_str);
+                       pr_err("%s is only meaningful when reshaping"
+                              " a RAID6 array.\n", s->layout_str);
                        rv = 1;
                        goto release;
                }
-       } else if (strcmp(layout_str, "preserve") == 0) {
+       } else if (strcmp(s->layout_str, "preserve") == 0) {
                /* This means that a non-standard RAID6 layout
                 * is OK.
                 * In particular:
@@ -1910,9 +1997,8 @@ size_change_error:
                        strcat(l, "-6");
                        info.new_layout = map_name(r6layout, l);
                } else {
-                       fprintf(stderr, Name
-                               ": %s in only meaningful when reshaping"
-                               " to RAID6\n", layout_str);
+                       pr_err("%s in only meaningful when reshaping"
+                              " to RAID6\n", s->layout_str);
                        rv = 1;
                        goto release;
                }
@@ -1922,55 +2008,55 @@ size_change_error:
                        l = info.array.level;
                switch (l) {
                case 5:
-                       info.new_layout = map_name(r5layout, layout_str);
+                       info.new_layout = map_name(r5layout, s->layout_str);
                        break;
                case 6:
-                       info.new_layout = map_name(r6layout, layout_str);
+                       info.new_layout = map_name(r6layout, s->layout_str);
                        break;
                case 10:
-                       info.new_layout = parse_layout_10(layout_str);
+                       info.new_layout = parse_layout_10(s->layout_str);
                        break;
                case LEVEL_FAULTY:
-                       info.new_layout = parse_layout_faulty(layout_str);
+                       info.new_layout = parse_layout_faulty(s->layout_str);
                        break;
                default:
-                       fprintf(stderr, Name ": layout not meaningful"
+                       pr_err("layout not meaningful"
                                " with this level\n");
                        rv = 1;
                        goto release;
                }
                if (info.new_layout == UnSet) {
-                       fprintf(stderr, Name ": layout %s not understood"
+                       pr_err("layout %s not understood"
                                " for this level\n",
-                               layout_str);
+                               s->layout_str);
                        rv = 1;
                        goto release;
                }
        }
 
        if (array.level == LEVEL_FAULTY) {
-               if (level != UnSet && level != array.level) {
-                       fprintf(stderr, Name ": cannot change level of Faulty device\n");
+               if (s->level != UnSet && s->level != array.level) {
+                       pr_err("cannot change level of Faulty device\n");
                        rv =1 ;
                }
-               if (chunksize) {
-                       fprintf(stderr, Name ": cannot set chunksize of Faulty device\n");
+               if (s->chunk) {
+                       pr_err("cannot set chunksize of Faulty device\n");
                        rv =1 ;
                }
-               if (raid_disks && raid_disks != 1) {
-                       fprintf(stderr, Name ": cannot set raid_disks of Faulty device\n");
+               if (s->raiddisks && s->raiddisks != 1) {
+                       pr_err("cannot set raid_disks of Faulty device\n");
                        rv =1 ;
                }
-               if (layout_str) {
+               if (s->layout_str) {
                        if (ioctl(fd, GET_ARRAY_INFO, &array) != 0) {
                                dprintf("Cannot get array information.\n");
                                goto release;
                        }
                        array.layout = info.new_layout;
                        if (ioctl(fd, SET_ARRAY_INFO, &array) != 0) {
-                               fprintf(stderr, Name ": failed to set new layout\n");
+                               pr_err("failed to set new layout\n");
                                rv = 1;
-                       } else if (!quiet)
+                       } else if (c->verbose >= 0)
                                printf("layout for %s set to %d\n",
                                       devname, array.layout);
                }
@@ -1984,7 +2070,7 @@ size_change_error:
                 * performed at the level of the container
                 */
                rv = reshape_container(container, devname, -1, st, &info,
-                                      force, backup_file, quiet, 0, 0);
+                                      c->force, c->backup_file, c->verbose, 0, 0, 0);
                frozen = 0;
        } else {
                /* get spare devices from external metadata
@@ -2003,17 +2089,18 @@ size_change_error:
                /* Impose these changes on a single array.  First
                 * check that the metadata is OK with the change. */
 
-               if (reshape_super(st, -1, info.new_level,
+               if (reshape_super(st, 0, info.new_level,
                                  info.new_layout, info.new_chunk,
                                  info.array.raid_disks, info.delta_disks,
-                                 backup_file, devname, APPLY_METADATA_CHANGES,
-                                 quiet)) {
+                                 c->backup_file, devname, APPLY_METADATA_CHANGES,
+                                 c->verbose)) {
                        rv = 1;
                        goto release;
                }
                sync_metadata(st);
-               rv = reshape_array(container, fd, devname, st, &info, force,
-                                  devlist, backup_file, quiet, 0, 0, 0);
+               rv = reshape_array(container, fd, devname, st, &info, c->force,
+                                  devlist, data_offset, c->backup_file, c->verbose,
+                                  0, 0, 0);
                frozen = 0;
        }
 release:
@@ -2046,7 +2133,7 @@ static int verify_reshape_position(struct mdinfo *info, int level)
                char *ep;
                unsigned long long position = strtoull(buf, &ep, 0);
 
-               dprintf(Name": Read sync_max sysfs entry is: %s\n", buf);
+               dprintf("Read sync_max sysfs entry is: %s\n", buf);
                if (!(ep == buf || (*ep != 0 && *ep != '\n' && *ep != ' '))) {
                        position *= get_data_disks(level,
                                                   info->new_layout,
@@ -2058,11 +2145,11 @@ static int verify_reshape_position(struct mdinfo *info, int level)
                                info->reshape_progress = position;
                                ret_val = 1;
                        } else if (info->reshape_progress > position) {
-                               fprintf(stderr, Name ": Fatal error: array "
-                                       "reshape was not properly frozen "
-                                       "(expected reshape position is %llu, "
-                                       "but reshape progress is %llu.\n",
-                                       position, info->reshape_progress);
+                               pr_err("Fatal error: array "
+                                      "reshape was not properly frozen "
+                                      "(expected reshape position is %llu, "
+                                      "but reshape progress is %llu.\n",
+                                      position, info->reshape_progress);
                                ret_val = -1;
                        } else {
                                dprintf("Reshape position in md and metadata "
@@ -2080,17 +2167,652 @@ static int verify_reshape_position(struct mdinfo *info, int level)
        return ret_val;
 }
 
+static unsigned long long choose_offset(unsigned long long lo,
+                                       unsigned long long hi,
+                                       unsigned long long min,
+                                       unsigned long long max)
+{
+       /* Choose a new offset between hi and lo.
+        * It must be between min and max, but
+        * we would prefer something near the middle of hi/lo, and also
+        * prefer to be aligned to a big power of 2.
+        *
+        * So we start with the middle, then for each bit,
+        * starting at '1' and increasing, if it is set, we either
+        * add it or subtract it if possible, preferring the option
+        * which is furthest from the boundary.
+        *
+        * We stop once we get a 1MB alignment. As units are in sectors,
+        * 1MB = 2*1024 sectors.
+        */
+       unsigned long long choice = (lo + hi) / 2;
+       unsigned long long bit = 1;
+
+       for (bit = 1; bit < 2*1024; bit = bit << 1) {
+               unsigned long long bigger, smaller;
+               if (! (bit & choice))
+                       continue;
+               bigger = choice + bit;
+               smaller = choice - bit;
+               if (bigger > max && smaller < min)
+                       break;
+               if (bigger > max)
+                       choice = smaller;
+               else if (smaller < min)
+                       choice = bigger;
+               else if (hi - bigger > smaller - lo)
+                       choice = bigger;
+               else
+                       choice = smaller;
+       }
+       return choice;
+}
+
+static int set_new_data_offset(struct mdinfo *sra, struct supertype *st,
+                              char *devname, int delta_disks,
+                              unsigned long long data_offset,
+                              unsigned long long min,
+                              int can_fallback)
+{
+       struct mdinfo *sd;
+       int dir = 0;
+       int err = 0;
+       unsigned long long before, after;
+
+       /* Need to find min space before and after so same is used
+        * on all devices
+        */
+       before = UINT64_MAX;
+       after = UINT64_MAX;
+       for (sd = sra->devs; sd; sd = sd->next) {
+               char *dn;
+               int dfd;
+               int rv;
+               struct supertype *st2;
+               struct mdinfo info2;
+
+               if (sd->disk.state & (1<<MD_DISK_FAULTY))
+                       continue;
+               dn = map_dev(sd->disk.major, sd->disk.minor, 0);
+               dfd = dev_open(dn, O_RDONLY);
+               if (dfd < 0) {
+                       pr_err("%s: cannot open component %s\n",
+                               devname, dn ? dn : "-unknown-");
+                       goto release;
+               }
+               st2 = dup_super(st);
+               rv = st2->ss->load_super(st2,dfd, NULL);
+               close(dfd);
+               if (rv) {
+                       free(st2);
+                       pr_err("%s: cannot get superblock from %s\n",
+                               devname, dn);
+                       goto release;
+               }
+               st2->ss->getinfo_super(st2, &info2, NULL);
+               st2->ss->free_super(st2);
+               free(st2);
+               if (info2.space_before == 0 &&
+                   info2.space_after == 0) {
+                       /* Metadata doesn't support data_offset changes */
+                       pr_err("%s: Metadata version doesn't support"
+                              " data_offset changes\n", devname);
+                       goto fallback;
+               }
+               if (before > info2.space_before)
+                       before = info2.space_before;
+               if (after > info2.space_after)
+                       after = info2.space_after;
+
+               if (data_offset != INVALID_SECTORS) {
+                       if (dir == 0) {
+                               if (info2.data_offset == data_offset) {
+                                       pr_err("%s: already has that data_offset\n",
+                                              dn);
+                                       goto release;
+                               }
+                               if (data_offset < info2.data_offset)
+                                       dir = -1;
+                               else
+                                       dir = 1;
+                       } else if ((data_offset <= info2.data_offset && dir == 1) ||
+                                  (data_offset >= info2.data_offset && dir == -1)) {
+                               pr_err("%s: differing data offsets on devices make this --data-offset setting impossible\n",
+                                       dn);
+                               goto release;
+                       }
+               }
+       }
+       if (before == UINT64_MAX)
+               /* impossible really, there must be no devices */
+               return 1;
+
+       for (sd = sra->devs; sd; sd = sd->next) {
+               char *dn = map_dev(sd->disk.major, sd->disk.minor, 0);
+               unsigned long long new_data_offset;
+
+               if (sd->disk.state & (1<<MD_DISK_FAULTY))
+                       continue;
+               if (delta_disks < 0) {
+                       /* Don't need any space as array is shrinking
+                        * just move data_offset up by min
+                        */
+                       if (data_offset == INVALID_SECTORS)
+                               new_data_offset = sd->data_offset + min;
+                       else {
+                               if (data_offset < sd->data_offset + min) {
+                                       pr_err("--data-offset too small for %s\n",
+                                               dn);
+                                       goto release;
+                               }
+                               new_data_offset = data_offset;
+                       }
+               } else if (delta_disks > 0) {
+                       /* need space before */
+                       if (before < min) {
+                               if (can_fallback)
+                                       goto fallback;
+                               pr_err("Insufficient head-space for reshape on %s\n",
+                                       dn);
+                               goto release;
+                       }
+                       if (data_offset == INVALID_SECTORS)
+                               new_data_offset = sd->data_offset - min;
+                       else {
+                               if (data_offset > sd->data_offset - min) {
+                                       pr_err("--data-offset too large for %s\n",
+                                               dn);
+                                       goto release;
+                               }
+                               new_data_offset = data_offset;
+                       }
+               } else {
+                       if (dir == 0) {
+                               /* can move up or down.  If 'data_offset'
+                                * was set we would have already decided,
+                                * so just choose direction with most space.
+                                */
+                               if (before > after)
+                                       dir = -1;
+                               else
+                                       dir = 1;
+                       }
+                       sysfs_set_str(sra, NULL, "reshape_direction",
+                                     dir == 1 ? "backwards" : "forwards");
+                       if (dir > 0) {
+                               /* Increase data offset */
+                               if (after < min) {
+                                       if (can_fallback)
+                                               goto fallback;
+                                       pr_err("Insufficient tail-space for reshape on %s\n",
+                                               dn);
+                                       goto release;
+                               }
+                               if (data_offset != INVALID_SECTORS &&
+                                   data_offset < sd->data_offset + min) {
+                                       pr_err("--data-offset too small on %s\n",
+                                               dn);
+                                       goto release;
+                               }
+                               if (data_offset != INVALID_SECTORS)
+                                       new_data_offset = data_offset;
+                               else
+                                       new_data_offset = choose_offset(sd->data_offset,
+                                                                       sd->data_offset + after,
+                                                                       sd->data_offset + min,
+                                                                       sd->data_offset + after);
+                       } else {
+                               /* Decrease data offset */
+                               if (before < min) {
+                                       if (can_fallback)
+                                               goto fallback;
+                                       pr_err("insufficient head-room on %s\n",
+                                               dn);
+                                       goto release;
+                               }
+                               if (data_offset != INVALID_SECTORS &&
+                                   data_offset < sd->data_offset - min) {
+                                       pr_err("--data-offset too small on %s\n",
+                                               dn);
+                                       goto release;
+                               }
+                               if (data_offset != INVALID_SECTORS)
+                                       new_data_offset = data_offset;
+                               else
+                                       new_data_offset = choose_offset(sd->data_offset - before,
+                                                                       sd->data_offset,
+                                                                       sd->data_offset - before,
+                                                                       sd->data_offset - min);
+                       }
+               }
+               err = sysfs_set_num(sra, sd, "new_offset", new_data_offset);
+               if (err < 0 && errno == E2BIG) {
+                       /* try again after increasing data size to max */
+                       err = sysfs_set_num(sra, sd, "size", 0);
+                       if (err < 0 && errno == EINVAL &&
+                           !(sd->disk.state & (1<<MD_DISK_SYNC))) {
+                               /* some kernels have a bug where you cannot
+                                * use '0' on spare devices. */
+                               sysfs_set_num(sra, sd, "size",
+                                             (sra->component_size + after)/2);
+                       }
+                       err = sysfs_set_num(sra, sd, "new_offset",
+                                           new_data_offset);
+               }
+               if (err < 0) {
+                       if (errno == E2BIG && data_offset != INVALID_SECTORS) {
+                               pr_err("data-offset is too big for %s\n",
+                                      dn);
+                               goto release;
+                       }
+                       if (sd == sra->devs &&
+                           (errno == ENOENT || errno == E2BIG))
+                               /* Early kernel, no 'new_offset' file,
+                                * or kernel doesn't like us.
+                                * For RAID5/6 this is not fatal
+                                */
+                               return 1;
+                       pr_err("Cannot set new_offset for %s\n",
+                               dn);
+                       break;
+               }
+       }
+       return err;
+release:
+       return -1;
+fallback:
+       /* Just use a backup file */
+       return 1;
+}
+
+static int raid10_reshape(char *container, int fd, char *devname,
+                         struct supertype *st, struct mdinfo *info,
+                         struct reshape *reshape,
+                         unsigned long long data_offset,
+                         int force, int verbose)
+{
+       /* Changing raid_disks, layout, chunksize or possibly
+        * just data_offset for a RAID10.
+        * We must always change data_offset.  We change by at least
+        * ->min_offset_change which is the largest of the old and new
+        * chunk sizes.
+        * If raid_disks is increasing, then data_offset must decrease
+        * by at least this copy size.
+        * If raid_disks is unchanged, data_offset must increase or
+        * decrease by at least min_offset_change but preferably by much more.
+        * We choose half of the available space.
+        * If raid_disks is decreasing, data_offset must increase by
+        * at least min_offset_change.  To allow of this, component_size
+        * must be decreased by the same amount.
+        *
+        * So we calculate the required minimum and direction, possibly
+        * reduce the component_size, then iterate through the devices
+        * and set the new_data_offset.
+        * If that all works, we set chunk_size, layout, raid_disks, and start
+        * 'reshape'
+        */
+       struct mdinfo *sra;
+       unsigned long long min;
+       int err = 0;
+
+       sra = sysfs_read(fd, NULL,
+                        GET_COMPONENT|GET_DEVS|GET_OFFSET|GET_STATE|GET_CHUNK
+               );
+       if (!sra) {
+               pr_err("%s: Cannot get array details from sysfs\n",
+                       devname);
+               goto release;
+       }
+       min = reshape->min_offset_change;
+
+       if (info->delta_disks)
+               sysfs_set_str(sra, NULL, "reshape_direction",
+                             info->delta_disks < 0 ? "backwards" : "forwards");
+       if (info->delta_disks < 0 &&
+           info->space_after < min) {
+               int rv = sysfs_set_num(sra, NULL, "component_size",
+                                      (sra->component_size -
+                                       min)/2);
+               if (rv) {
+                       pr_err("cannot reduce component size\n");
+                       goto release;
+               }
+       }
+       err = set_new_data_offset(sra, st, devname, info->delta_disks, data_offset,
+                                 min, 0);
+       if (err == 1) {
+               pr_err("Cannot set new_data_offset: RAID10 reshape not\n");
+               cont_err("supported on this kernel\n");
+               err = -1;
+       }
+       if (err < 0)
+               goto release;
+
+       if (!err && sysfs_set_num(sra, NULL, "chunk_size", info->new_chunk) < 0)
+               err = errno;
+       if (!err && sysfs_set_num(sra, NULL, "layout", reshape->after.layout) < 0)
+               err = errno;
+       if (!err && sysfs_set_num(sra, NULL, "raid_disks",
+                                 info->array.raid_disks + info->delta_disks) < 0)
+               err = errno;
+       if (!err && sysfs_set_str(sra, NULL, "sync_action", "reshape") < 0)
+               err = errno;
+       if (err) {
+               pr_err("Cannot set array shape for %s\n",
+                      devname);
+               if (err == EBUSY &&
+                   (info->array.state & (1<<MD_SB_BITMAP_PRESENT)))
+                       cont_err("       Bitmap must be removed before"
+                                " shape can be changed\n");
+               goto release;
+       }
+       sysfs_free(sra);
+       return 0;
+release:
+       sysfs_free(sra);
+       return 1;
+}
+
+static void get_space_after(int fd, struct supertype *st, struct mdinfo *info)
+{
+       struct mdinfo *sra, *sd;
+       /* Initialisation to silence compiler warning */
+       unsigned long long min_space_before = 0, min_space_after = 0;
+       int first = 1;
+
+       sra = sysfs_read(fd, NULL, GET_DEVS);
+       if (!sra)
+               return;
+       for (sd = sra->devs; sd; sd = sd->next) {
+               char *dn;
+               int dfd;
+               struct supertype *st2;
+               struct mdinfo info2;
+
+               if (sd->disk.state & (1<<MD_DISK_FAULTY))
+                       continue;
+               dn = map_dev(sd->disk.major, sd->disk.minor, 0);
+               dfd = dev_open(dn, O_RDONLY);
+               if (dfd < 0)
+                       break;
+               st2 = dup_super(st);
+               if (st2->ss->load_super(st2,dfd, NULL)) {
+                       close(dfd);
+                       free(st2);
+                       break;
+               }
+               close(dfd);
+               st2->ss->getinfo_super(st2, &info2, NULL);
+               st2->ss->free_super(st2);
+               free(st2);
+               if (first ||
+                   min_space_before > info2.space_before)
+                       min_space_before = info2.space_before;
+               if (first ||
+                   min_space_after > info2.space_after)
+                       min_space_after = info2.space_after;
+               first = 0;
+       }
+       if (sd == NULL && !first) {
+               info->space_after = min_space_after;
+               info->space_before = min_space_before;
+       }
+       sysfs_free(sra);
+}
+
+static void update_cache_size(char *container, struct mdinfo *sra,
+                             struct mdinfo *info,
+                             int disks, unsigned long long blocks)
+{
+       /* Check that the internal stripe cache is
+        * large enough, or it won't work.
+        * It must hold at least 4 stripes of the larger
+        * chunk size
+        */
+       unsigned long cache;
+       cache = max(info->array.chunk_size, info->new_chunk);
+       cache *= 4; /* 4 stripes minimum */
+       cache /= 512; /* convert to sectors */
+       /* make sure there is room for 'blocks' with a bit to spare */
+       if (cache < 16 + blocks / disks)
+               cache = 16 + blocks / disks;
+       cache /= (4096/512); /* Covert from sectors to pages */
+
+       if (sra->cache_size < cache)
+               subarray_set_num(container, sra, "stripe_cache_size",
+                                cache+1);
+}
+
+static int impose_reshape(struct mdinfo *sra,
+                         struct mdinfo *info,
+                         struct supertype *st,
+                         int fd,
+                         int restart,
+                         char *devname, char *container,
+                         struct reshape *reshape)
+{
+       struct mdu_array_info_s array;
+
+       sra->new_chunk = info->new_chunk;
+
+       if (restart) {
+               /* for external metadata checkpoint saved by mdmon can be lost
+                * or missed /due to e.g. crash/. Check if md is not during
+                * restart farther than metadata points to.
+                * If so, this means metadata information is obsolete.
+                */
+               if (st->ss->external)
+                       verify_reshape_position(info, reshape->level);
+               sra->reshape_progress = info->reshape_progress;
+       } else {
+               sra->reshape_progress = 0;
+               if (reshape->after.data_disks < reshape->before.data_disks)
+                       /* start from the end of the new array */
+                       sra->reshape_progress = (sra->component_size
+                                                * reshape->after.data_disks);
+       }
+
+       ioctl(fd, GET_ARRAY_INFO, &array);
+       if (info->array.chunk_size == info->new_chunk &&
+           reshape->before.layout == reshape->after.layout &&
+           st->ss->external == 0) {
+               /* use SET_ARRAY_INFO but only if reshape hasn't started */
+               array.raid_disks = reshape->after.data_disks + reshape->parity;
+               if (!restart &&
+                   ioctl(fd, SET_ARRAY_INFO, &array) != 0) {
+                       int err = errno;
+
+                       pr_err("Cannot set device shape for %s: %s\n",
+                              devname, strerror(errno));
+
+                       if (err == EBUSY &&
+                           (array.state & (1<<MD_SB_BITMAP_PRESENT)))
+                               cont_err("Bitmap must be removed before"
+                                        " shape can be changed\n");
+
+                       goto release;
+               }
+       } else if (!restart) {
+               /* set them all just in case some old 'new_*' value
+                * persists from some earlier problem.
+                */
+               int err = 0;
+               if (sysfs_set_num(sra, NULL, "chunk_size", info->new_chunk) < 0)
+                       err = errno;
+               if (!err && sysfs_set_num(sra, NULL, "layout",
+                                         reshape->after.layout) < 0)
+                       err = errno;
+               if (!err && subarray_set_num(container, sra, "raid_disks",
+                                            reshape->after.data_disks +
+                                            reshape->parity) < 0)
+                       err = errno;
+               if (err) {
+                       pr_err("Cannot set device shape for %s\n",
+                               devname);
+
+                       if (err == EBUSY &&
+                           (array.state & (1<<MD_SB_BITMAP_PRESENT)))
+                               cont_err("Bitmap must be removed before"
+                                        " shape can be changed\n");
+                       goto release;
+               }
+       }
+       return 0;
+release:
+       return -1;
+}
+
+static int impose_level(int fd, int level, char *devname, int verbose)
+{
+       char *c;
+       struct mdu_array_info_s array;
+       struct mdinfo info;
+       sysfs_init(&info, fd, NULL);
+
+       ioctl(fd, GET_ARRAY_INFO, &array);
+       if (level == 0 &&
+           (array.level >= 4 && array.level <= 6)) {
+               /* To convert to RAID0 we need to fail and
+                * remove any non-data devices. */
+               int found = 0;
+               int d;
+               int data_disks = array.raid_disks - 1;
+               if (array.level == 6)
+                       data_disks -= 1;
+               if (array.level == 5 &&
+                   array.layout != ALGORITHM_PARITY_N)
+                       return -1;
+               if (array.level == 6 &&
+                   array.layout != ALGORITHM_PARITY_N_6)
+                       return -1;
+               sysfs_set_str(&info, NULL,"sync_action", "idle");
+               /* First remove any spares so no recovery starts */
+               for (d = 0, found = 0;
+                    d < MAX_DISKS && found < array.nr_disks;
+                    d++) {
+                       mdu_disk_info_t disk;
+                       disk.number = d;
+                       if (ioctl(fd, GET_DISK_INFO, &disk) < 0)
+                               continue;
+                       if (disk.major == 0 && disk.minor == 0)
+                               continue;
+                       found++;
+                       if ((disk.state & (1 << MD_DISK_ACTIVE))
+                           && disk.raid_disk < data_disks)
+                               /* keep this */
+                               continue;
+                       ioctl(fd, HOT_REMOVE_DISK,
+                             makedev(disk.major, disk.minor));
+               }
+               /* Now fail anything left */
+               ioctl(fd, GET_ARRAY_INFO, &array);
+               for (d = 0, found = 0;
+                    d < MAX_DISKS && found < array.nr_disks;
+                    d++) {
+                       int cnt;
+                       mdu_disk_info_t disk;
+                       disk.number = d;
+                       if (ioctl(fd, GET_DISK_INFO, &disk) < 0)
+                               continue;
+                       if (disk.major == 0 && disk.minor == 0)
+                               continue;
+                       found++;
+                       if ((disk.state & (1 << MD_DISK_ACTIVE))
+                           && disk.raid_disk < data_disks)
+                               /* keep this */
+                               continue;
+                       ioctl(fd, SET_DISK_FAULTY,
+                             makedev(disk.major, disk.minor));
+                       cnt = 5;
+                       while (ioctl(fd, HOT_REMOVE_DISK,
+                                    makedev(disk.major, disk.minor)) < 0
+                              && errno == EBUSY
+                              && cnt--) {
+                               usleep(10000);
+                       }
+               }
+       }
+       c = map_num(pers, level);
+       if (c) {
+               int err = sysfs_set_str(&info, NULL, "level", c);
+               if (err) {
+                       err = errno;
+                       pr_err("%s: could not set level to %s\n",
+                               devname, c);
+                       if (err == EBUSY &&
+                           (array.state & (1<<MD_SB_BITMAP_PRESENT)))
+                               cont_err("Bitmap must be removed"
+                                        " before level can be changed\n");
+                       return err;
+               }
+               if (verbose >= 0)
+                       pr_err("level of %s changed to %s\n",
+                               devname, c);
+       }
+       return 0;
+}
+
+int sigterm = 0;
+static void catch_term(int sig)
+{
+       sigterm = 1;
+}
+
+static int continue_via_systemd(char *devnm)
+{
+       int skipped, i, pid, status;
+       char pathbuf[1024];
+       /* In a systemd/udev world, it is best to get systemd to
+        * run "mdadm --grow --continue" rather than running in the
+        * background.
+        */
+       switch(fork()) {
+       case  0:
+               /* FIXME yuk. CLOSE_EXEC?? */
+               skipped = 0;
+               for (i = 3; skipped < 20; i++)
+                       if (close(i) < 0)
+                               skipped++;
+                       else
+                               skipped = 0;
+
+               /* Don't want to see error messages from
+                * systemctl.  If the service doesn't exist,
+                * we fork ourselves.
+                */
+               close(2);
+               open("/dev/null", O_WRONLY);
+               snprintf(pathbuf, sizeof(pathbuf), "mdadm-grow-continue@%s.service",
+                        devnm);
+               status = execl("/usr/bin/systemctl", "systemctl",
+                              "start",
+                              pathbuf, NULL);
+               status = execl("/bin/systemctl", "systemctl", "start",
+                              pathbuf, NULL);
+               exit(1);
+       case -1: /* Just do it ourselves. */
+               break;
+       default: /* parent - good */
+               pid = wait(&status);
+               if (pid >= 0 && status == 0)
+                       return 1;
+       }
+       return 0;
+}
+
 static int reshape_array(char *container, int fd, char *devname,
                         struct supertype *st, struct mdinfo *info,
                         int force, struct mddev_dev *devlist,
-                        char *backup_file, int quiet, int forked,
+                        unsigned long long data_offset,
+                        char *backup_file, int verbose, int forked,
                         int restart, int freeze_reshape)
 {
        struct reshape reshape;
        int spares_needed;
        char *msg;
        int orig_level = UnSet;
-       int disks, odisks;
+       int odisks;
+       int delayed;
 
        struct mdu_array_info_s array;
        char *c;
@@ -2104,10 +2826,10 @@ static int reshape_array(char *container, int fd, char *devname,
        int nrdisks;
        int err;
        unsigned long blocks;
-       unsigned long cache;
        unsigned long long array_size;
        int done;
        struct mdinfo *sra = NULL;
+       char buf[20];
 
        /* when reshaping a RAID0, the component_size might be zero.
         * So try to fix that up.
@@ -2121,12 +2843,16 @@ static int reshape_array(char *container, int fd, char *devname,
                info->component_size = array_size / array.raid_disks;
        }
 
+       if (array.level == 10)
+               /* Need space_after info */
+               get_space_after(fd, st, info);
+
        if (info->reshape_active) {
                int new_level = info->new_level;
                info->new_level = UnSet;
                if (info->delta_disks > 0)
                        info->array.raid_disks -= info->delta_disks;
-               msg = analyse_change(info, &reshape);
+               msg = analyse_change(devname, info, &reshape);
                info->new_level = new_level;
                if (info->delta_disks > 0)
                        info->array.raid_disks += info->delta_disks;
@@ -2134,9 +2860,11 @@ static int reshape_array(char *container, int fd, char *devname,
                        /* Make sure the array isn't read-only */
                        ioctl(fd, RESTART_ARRAY_RW, 0);
        } else
-               msg = analyse_change(info, &reshape);
+               msg = analyse_change(devname, info, &reshape);
        if (msg) {
-               fprintf(stderr, Name ": %s\n", msg);
+               /* if msg == "", error has already been printed */
+               if (msg[0])
+                       pr_err("%s\n", msg);
                goto release;
        }
        if (restart &&
@@ -2144,12 +2872,14 @@ static int reshape_array(char *container, int fd, char *devname,
             reshape.before.layout != info->array.layout ||
             reshape.before.data_disks + reshape.parity
             != info->array.raid_disks - max(0, info->delta_disks))) {
-               fprintf(stderr, Name ": reshape info is not in native format -"
+               pr_err("reshape info is not in native format -"
                        " cannot continue.\n");
                goto release;
        }
 
-       if (st->ss->external && restart && (info->reshape_progress == 0)) {
+       if (st->ss->external && restart && (info->reshape_progress == 0) &&
+           !((sysfs_get_str(info, NULL, "sync_action", buf, sizeof(buf)) > 0) &&
+             (strncmp(buf, "reshape", 7) == 0))) {
                /* When reshape is restarted from '0', very begin of array
                 * it is possible that for external metadata reshape and array
                 * configuration doesn't happen.
@@ -2165,6 +2895,22 @@ static int reshape_array(char *container, int fd, char *devname,
                /* reshape already started. just skip to monitoring the reshape */
                if (reshape.backup_blocks == 0)
                        return 0;
+               if (restart & RESHAPE_NO_BACKUP)
+                       return 0;
+
+               /* Need 'sra' down at 'started:' */
+               sra = sysfs_read(fd, NULL,
+                                GET_COMPONENT|GET_DEVS|GET_OFFSET|GET_STATE|GET_CHUNK|
+                                GET_CACHE);
+               if (!sra) {
+                       pr_err("%s: Cannot get array details from sysfs\n",
+                              devname);
+                       goto release;
+               }
+
+               if (!backup_file)
+                       backup_file = locate_backup(sra->sys_name);
+
                goto started;
        }
        /* The container is frozen but the array may not be.
@@ -2184,13 +2930,12 @@ static int reshape_array(char *container, int fd, char *devname,
        if (!force &&
            info->new_level > 1 && info->array.level > 1 &&
            spares_needed > info->array.spare_disks + added_disks) {
-               fprintf(stderr,
-                       Name ": Need %d spare%s to avoid degraded array,"
-                       " and only have %d.\n"
-                       "       Use --force to over-ride this check.\n",
-                       spares_needed,
-                       spares_needed == 1 ? "" : "s",
-                       info->array.spare_disks + added_disks);
+               pr_err("Need %d spare%s to avoid degraded array,"
+                      " and only have %d.\n"
+                      "       Use --force to over-ride this check.\n",
+                      spares_needed,
+                      spares_needed == 1 ? "" : "s",
+                      info->array.spare_disks + added_disks);
                goto release;
        }
        /* Check we have enough spares to not fail */
@@ -2199,47 +2944,32 @@ static int reshape_array(char *container, int fd, char *devname,
                - array.raid_disks;
        if ((info->new_level > 1 || info->new_level == 0) &&
            spares_needed > info->array.spare_disks +added_disks) {
-               fprintf(stderr,
-                       Name ": Need %d spare%s to create working array,"
-                       " and only have %d.\n",
-                       spares_needed,
-                       spares_needed == 1 ? "" : "s",
-                       info->array.spare_disks + added_disks);
+               pr_err("Need %d spare%s to create working array,"
+                      " and only have %d.\n",
+                      spares_needed,
+                      spares_needed == 1 ? "" : "s",
+                      info->array.spare_disks + added_disks);
                goto release;
        }
 
        if (reshape.level != array.level) {
-               char *c = map_num(pers, reshape.level);
-               int err;
-               if (c == NULL)
-                       goto release;
-
-               err = sysfs_set_str(info, NULL, "level", c);
-               if (err) {
-                       err = errno;
-                       fprintf(stderr, Name ": %s: could not set level to %s\n",
-                               devname, c);
-                       if (err == EBUSY &&
-                           (info->array.state & (1<<MD_SB_BITMAP_PRESENT)))
-                               fprintf(stderr, "       Bitmap must be removed"
-                                       " before level can be changed\n");
+               int err = impose_level(fd, reshape.level, devname, verbose);
+               if (err)
                        goto release;
-               }
-               if (!quiet)
-                       fprintf(stderr, Name ": level of %s changed to %s\n",
-                               devname, c);
+               info->new_layout = UnSet; /* after level change,
+                                          * layout is meaningless */
                orig_level = array.level;
                sysfs_freeze_array(info);
 
                if (reshape.level > 0 && st->ss->external) {
                        /* make sure mdmon is aware of the new level */
-                       if (mdmon_running(st->container_dev))
+                       if (mdmon_running(container))
                                flush_mdmon(container);
 
-                       if (!mdmon_running(st->container_dev))
-                               start_mdmon(st->container_dev);
+                       if (!mdmon_running(container))
+                               start_mdmon(container);
                        ping_monitor(container);
-                       if (mdmon_running(st->container_dev) &&
+                       if (mdmon_running(container) &&
                            st->update_tail == NULL)
                                st->update_tail = &st->updates;
                }
@@ -2256,7 +2986,7 @@ static int reshape_array(char *container, int fd, char *devname,
                struct mdinfo *d;
 
                if (info2) {
-                       sysfs_init(info2, fd, st->devnum);
+                       sysfs_init(info2, fd, st->devnm);
                        /* When increasing number of devices, we need to set
                         * new raid_disks before adding these, or they might
                         * be rejected.
@@ -2283,9 +3013,11 @@ static int reshape_array(char *container, int fd, char *devname,
         * level and frozen, we can safely add them.
         */
        if (devlist)
-               Manage_subdevs(devname, fd, devlist, !quiet,
+               Manage_subdevs(devname, fd, devlist, verbose,
                               0,NULL, 0);
 
+       if (reshape.backup_blocks == 0 && data_offset != INVALID_SECTORS)
+               reshape.backup_blocks = reshape.before.data_disks * info->array.chunk_size/512;
        if (reshape.backup_blocks == 0) {
                /* No restriping needed, but we might need to impose
                 * some more changes: layout, raid_disks, chunk_size
@@ -2301,9 +3033,9 @@ static int reshape_array(char *container, int fd, char *devname,
                    info->new_layout != array.layout) {
                        array.layout = info->new_layout;
                        if (ioctl(fd, SET_ARRAY_INFO, &array) != 0) {
-                               fprintf(stderr, Name ": failed to set new layout\n");
+                               pr_err("failed to set new layout\n");
                                goto release;
-                       } else if (!quiet)
+                       } else if (verbose >= 0)
                                printf("layout for %s set to %d\n",
                                       devname, array.layout);
                }
@@ -2312,9 +3044,9 @@ static int reshape_array(char *container, int fd, char *devname,
                    array.raid_disks != (info->array.raid_disks + info->delta_disks)) {
                        array.raid_disks += info->delta_disks;
                        if (ioctl(fd, SET_ARRAY_INFO, &array) != 0) {
-                               fprintf(stderr, Name ": failed to set raid disks\n");
+                               pr_err("failed to set raid disks\n");
                                goto release;
-                       } else if (!quiet) {
+                       } else if (verbose >= 0) {
                                printf("raid_disks for %s set to %d\n",
                                       devname, array.raid_disks);
                        }
@@ -2323,9 +3055,9 @@ static int reshape_array(char *container, int fd, char *devname,
                    info->new_chunk != array.chunk_size) {
                        if (sysfs_set_num(info, NULL,
                                          "chunk_size", info->new_chunk) != 0) {
-                               fprintf(stderr, Name ": failed to set chunk size\n");
+                               pr_err("failed to set chunk size\n");
                                goto release;
-                       } else if (!quiet)
+                       } else if (verbose >= 0)
                                printf("chunk size for %s set to %d\n",
                                       devname, array.chunk_size);
                }
@@ -2366,27 +3098,90 @@ static int reshape_array(char *container, int fd, char *devname,
         *   -  request the shape change.
         *   -  fork to handle backup etc.
         */
-started:
        /* Check that we can hold all the data */
        get_dev_size(fd, NULL, &array_size);
        if (reshape.new_size < (array_size/512)) {
-               fprintf(stderr,
-                       Name ": this change will reduce the size of the array.\n"
-                       "       use --grow --array-size first to truncate array.\n"
-                       "       e.g. mdadm --grow %s --array-size %llu\n",
-                       devname, reshape.new_size/2);
+               pr_err("this change will reduce the size of the array.\n"
+                      "       use --grow --array-size first to truncate array.\n"
+                      "       e.g. mdadm --grow %s --array-size %llu\n",
+                      devname, reshape.new_size/2);
                goto release;
        }
 
-       sra = sysfs_read(fd, 0,
+       if (array.level == 10) {
+               /* Reshaping RAID10 does not require any data backup by
+                * user-space.  Instead it requires that the data_offset
+                * is changed to avoid the need for backup.
+                * So this is handled very separately
+                */
+               if (restart)
+                       /* Nothing to do. */
+                       return 0;
+               return raid10_reshape(container, fd, devname, st, info,
+                                     &reshape, data_offset,
+                                     force, verbose);
+       }
+       sra = sysfs_read(fd, NULL,
                         GET_COMPONENT|GET_DEVS|GET_OFFSET|GET_STATE|GET_CHUNK|
                         GET_CACHE);
        if (!sra) {
-               fprintf(stderr, Name ": %s: Cannot get array details from sysfs\n",
+               pr_err("%s: Cannot get array details from sysfs\n",
                        devname);
                goto release;
        }
 
+       if (!backup_file)
+               switch(set_new_data_offset(sra, st, devname,
+                                          reshape.after.data_disks - reshape.before.data_disks,
+                                          data_offset,
+                                          reshape.min_offset_change, 1)) {
+       case -1:
+               goto release;
+       case 0:
+               /* Updated data_offset, so it's easy now */
+               update_cache_size(container, sra, info,
+                                 min(reshape.before.data_disks,
+                                     reshape.after.data_disks),
+                                 reshape.backup_blocks);
+
+               /* Right, everything seems fine. Let's kick things off.
+                */
+               sync_metadata(st);
+
+               if (impose_reshape(sra, info, st, fd, restart,
+                                  devname, container, &reshape) < 0)
+                       goto release;
+               if (sysfs_set_str(sra, NULL, "sync_action", "reshape") < 0) {
+                       pr_err("Failed to initiate reshape!\n");
+                       goto release;
+               }
+               if (info->new_level == reshape.level)
+                       return 0;
+               /* need to adjust level when reshape completes */
+               switch(fork()) {
+               case -1: /* ignore error, but don't wait */
+                       return 0;
+               default: /* parent */
+                       return 0;
+               case 0:
+                       map_fork();
+                       break;
+               }
+               close(fd);
+               wait_reshape(sra);
+               fd = open_dev(sra->sys_name);
+               if (fd >= 0)
+                       impose_level(fd, info->new_level, devname, verbose);
+               return 0;
+       case 1: /* Couldn't set data_offset, try the old way */
+               if (data_offset != INVALID_SECTORS) {
+                       pr_err("Cannot update data_offset on this array\n");
+                       goto release;
+               }
+               break;
+       }
+
+started:
        /* Decide how many blocks (sectors) for a reshape
         * unit.  The number we have so far is just a minimum
         */
@@ -2401,11 +3196,11 @@ started:
                       blocks < 16*1024*2)
                        blocks *= 2;
        } else
-               fprintf(stderr, Name ": Need to backup %luK of critical "
+               pr_err("Need to backup %luK of critical "
                        "section..\n", blocks/2);
 
        if (blocks >= sra->component_size/2) {
-               fprintf(stderr, Name ": %s: Something wrong"
+               pr_err("%s: Something wrong"
                        " - reshape aborted\n",
                        devname);
                goto release;
@@ -2416,12 +3211,8 @@ started:
        nrdisks = max(reshape.before.data_disks,
                      reshape.after.data_disks) + reshape.parity
                + sra->array.spare_disks;
-       fdlist = malloc((1+nrdisks) * sizeof(int));
-       offsets = malloc((1+nrdisks) * sizeof(offsets[0]));
-       if (!fdlist || !offsets) {
-               fprintf(stderr, Name ": malloc failed: grow aborted\n");
-               goto release;
-       }
+       fdlist = xcalloc((1+nrdisks), sizeof(int));
+       offsets = xcalloc((1+nrdisks), sizeof(offsets[0]));
 
        odisks = reshape.before.data_disks + reshape.parity;
        d = reshape_prepare_fdlist(devname, sra, odisks,
@@ -2435,11 +3226,12 @@ started:
                if (backup_file == NULL) {
                        if (reshape.after.data_disks <=
                            reshape.before.data_disks) {
-                               fprintf(stderr, Name ": %s: Cannot grow - "
-                                       "need backup-file\n", devname);
+                               pr_err("%s: Cannot grow - need backup-file\n",
+                                      devname);
+                               pr_err(" Please provide one with \"--backup=...\"\n");
                                goto release;
                        } else if (sra->array.spare_disks == 0) {
-                               fprintf(stderr, Name ": %s: Cannot grow - "
+                               pr_err("%s: Cannot grow - "
                                        "need a spare or backup-file to backup "
                                        "critical section\n", devname);
                                goto release;
@@ -2448,6 +3240,7 @@ started:
                        if (!reshape_open_backup_file(backup_file, fd, devname,
                                                      (signed)blocks,
                                                      fdlist+d, offsets+d,
+                                                     sra->sys_name,
                                                      restart)) {
                                goto release;
                        }
@@ -2455,23 +3248,9 @@ started:
                }
        }
 
-       /* lastly, check that the internal stripe cache is
-        * large enough, or it won't work.
-        * It must hold at least 4 stripes of the larger
-        * chunk size
-        */
-       cache = max(info->array.chunk_size, info->new_chunk);
-       cache *= 4; /* 4 stripes minimum */
-       cache /= 512; /* convert to sectors */
-       disks = min(reshape.before.data_disks, reshape.after.data_disks);
-       /* make sure there is room for 'blocks' with a bit to spare */
-       if (cache < 16 + blocks / disks)
-               cache = 16 + blocks / disks;
-       cache /= (4096/512); /* Covert from sectors to pages */
-
-       if (sra->cache_size < cache)
-               subarray_set_num(container, sra, "stripe_cache_size",
-                                cache+1);
+       update_cache_size(container, sra, info,
+                         min(reshape.before.data_disks, reshape.after.data_disks),
+                         blocks);
 
        /* Right, everything seems fine. Let's kick things off.
         * If only changing raid_disks, use ioctl, else use
@@ -2479,81 +3258,16 @@ started:
         */
        sync_metadata(st);
 
-       sra->new_chunk = info->new_chunk;
-
-       if (restart) {
-               /* for external metadata checkpoint saved by mdmon can be lost
-                * or missed /due to e.g. crash/. Check if md is not during
-                * restart farther than metadata points to.
-                * If so, this means metadata information is obsolete.
-                */
-               if (st->ss->external)
-                       verify_reshape_position(info, reshape.level);
-               sra->reshape_progress = info->reshape_progress;
-       } else {
-               sra->reshape_progress = 0;
-               if (reshape.after.data_disks < reshape.before.data_disks)
-                       /* start from the end of the new array */
-                       sra->reshape_progress = (sra->component_size
-                                                * reshape.after.data_disks);
-       }
-
-       if (info->array.chunk_size == info->new_chunk &&
-           reshape.before.layout == reshape.after.layout &&
-           st->ss->external == 0) {
-               /* use SET_ARRAY_INFO but only if reshape hasn't started */
-               ioctl(fd, GET_ARRAY_INFO, &array);
-               array.raid_disks = reshape.after.data_disks + reshape.parity;
-               if (!restart &&
-                   ioctl(fd, SET_ARRAY_INFO, &array) != 0) {
-                       int err = errno;
-
-                       fprintf(stderr,
-                               Name ": Cannot set device shape for %s: %s\n",
-                               devname, strerror(errno));
-
-                       if (err == EBUSY &&
-                           (array.state & (1<<MD_SB_BITMAP_PRESENT)))
-                               fprintf(stderr,
-                                       "       Bitmap must be removed before"
-                                       " shape can be changed\n");
-
-                       goto release;
-               }
-       } else if (!restart) {
-               /* set them all just in case some old 'new_*' value
-                * persists from some earlier problem.
-                */
-               int err = 0;
-               if (sysfs_set_num(sra, NULL, "chunk_size", info->new_chunk) < 0)
-                       err = errno;
-               if (!err && sysfs_set_num(sra, NULL, "layout",
-                                         reshape.after.layout) < 0)
-                       err = errno;
-               if (!err && subarray_set_num(container, sra, "raid_disks",
-                                            reshape.after.data_disks +
-                                            reshape.parity) < 0)
-                       err = errno;
-               if (err) {
-                       fprintf(stderr, Name ": Cannot set device shape for %s\n",
-                               devname);
-
-                       if (err == EBUSY &&
-                           (array.state & (1<<MD_SB_BITMAP_PRESENT)))
-                               fprintf(stderr,
-                                       "       Bitmap must be removed before"
-                                       " shape can be changed\n");
-                       goto release;
-               }
-       }
+       if (impose_reshape(sra, info, st, fd, restart,
+                          devname, container, &reshape) < 0)
+               goto release;
 
        err = start_reshape(sra, restart, reshape.before.data_disks,
                            reshape.after.data_disks);
        if (err) {
-               fprintf(stderr,
-                       Name ": Cannot %s reshape for %s\n",
-                       restart ? "continue" : "start",
-                       devname);
+               pr_err("Cannot %s reshape for %s\n",
+                      restart ? "continue" : "start",
+                      devname);
                goto release;
        }
        if (restart)
@@ -2562,19 +3276,27 @@ started:
                free(fdlist);
                free(offsets);
                sysfs_free(sra);
-               fprintf(stderr, Name ": Reshape has to be continued from"
+               pr_err("Reshape has to be continued from"
                        " location %llu when root filesystem has been mounted.\n",
                        sra->reshape_progress);
                return 1;
        }
 
+       if (!forked && !check_env("MDADM_NO_SYSTEMCTL"))
+               if (continue_via_systemd(container ?: sra->sys_name)) {
+                       free(fdlist);
+                       free(offsets);
+                       sysfs_free(sra);
+                       return 0;
+               }
+
        /* Now we just need to kick off the reshape and watch, while
         * handling backups of the data...
         * This is all done by a forked background process.
         */
        switch(forked ? 0 : fork()) {
        case -1:
-               fprintf(stderr, Name ": Cannot run child to monitor reshape: %s\n",
+               pr_err("Cannot run child to monitor reshape: %s\n",
                        strerror(errno));
                abort_reshape(sra);
                goto release;
@@ -2588,6 +3310,39 @@ started:
                break;
        }
 
+       /* If another array on the same devices is busy, the
+        * reshape will wait for them.  This would mean that
+        * the first section that we suspend will stay suspended
+        * for a long time.  So check on that possibility
+        * by looking for "DELAYED" in /proc/mdstat, and if found,
+        * wait a while
+        */
+       do {
+               struct mdstat_ent *mds, *m;
+               delayed = 0;
+               mds = mdstat_read(1, 0);
+               for (m = mds; m; m = m->next)
+                       if (strcmp(m->devnm, sra->sys_name) == 0) {
+                               if (m->resync &&
+                                   m->percent == RESYNC_DELAYED)
+                                       delayed = 1;
+                               if (m->resync == 0)
+                                       /* Haven't started the reshape thread
+                                        * yet, wait a bit
+                                        */
+                                       delayed = 2;
+                               break;
+                       }
+               free_mdstat(mds);
+               if (delayed == 1 && get_linux_version() < 3007000) {
+                       pr_err("Reshape is delayed, but cannot wait carefully with this kernel.\n"
+                              "       You might experience problems until other reshapes complete.\n");
+                       delayed = 0;
+               }
+               if (delayed)
+                       mdstat_wait(30 - (delayed-1) * 25);
+       } while (delayed);
+       mdstat_close();
        close(fd);
        if (check_env("MDADM_GROW_VERIFY"))
                fd = open(devname, O_RDONLY | O_DIRECT);
@@ -2595,6 +3350,8 @@ started:
                fd = -1;
        mlockall(MCL_FUTURE);
 
+       signal(SIGTERM, catch_term);
+
        if (st->ss->external) {
                /* metadata handler takes it from here */
                done = st->ss->manage_reshape(
@@ -2612,8 +3369,21 @@ started:
        free(fdlist);
        free(offsets);
 
-       if (backup_file && done)
+       if (backup_file && done) {
+               char *bul;
+               bul = make_backup(sra->sys_name);
+               if (bul) {
+                       char buf[1024];
+                       int l = readlink(bul, buf, sizeof(buf));
+                       if (l > 0) {
+                               buf[l]=0;
+                               unlink(buf);
+                       }
+                       unlink(bul);
+                       free(bul);
+               }
                unlink(backup_file);
+       }
        if (!done) {
                abort_reshape(sra);
                goto out;
@@ -2634,7 +3404,7 @@ started:
 
        if (st->ss->external) {
                /* Re-load the metadata as much could have changed */
-               int cfd = open_dev(st->container_dev);
+               int cfd = open_dev(st->container_devnm);
                if (cfd >= 0) {
                        flush_mdmon(container);
                        st->ss->free_super(st);
@@ -2652,15 +3422,10 @@ started:
                set_array_size(st, info, info->text_version);
 
        if (info->new_level != reshape.level) {
-
-               c = map_num(pers, info->new_level);
-               if (c) {
-                       err = sysfs_set_str(sra, NULL, "level", c);
-                       if (err)
-                               fprintf(stderr, Name\
-                                       ": %s: could not set level "
-                                       "to %s\n", devname, c);
-               }
+               if (fd < 0)
+                       fd = open(devname, O_RDONLY);
+               impose_level(fd, info->new_level, devname, verbose);
+               close(fd);
                if (info->new_level == 0)
                        st->update_tail = NULL;
        }
@@ -2677,7 +3442,7 @@ release:
        if (orig_level != UnSet && sra) {
                c = map_num(pers, orig_level);
                if (c && sysfs_set_str(sra, NULL, "level", c) == 0)
-                       fprintf(stderr, Name ": aborting level change\n");
+                       pr_err("aborting level change\n");
        }
        sysfs_free(sra);
        if (!forked)
@@ -2692,22 +3457,22 @@ int reshape_container(char *container, char *devname,
                      struct supertype *st,
                      struct mdinfo *info,
                      int force,
-                     char *backup_file,
-                     int quiet, int restart, int freeze_reshape)
+                     char *backup_file, int verbose,
+                     int forked, int restart, int freeze_reshape)
 {
        struct mdinfo *cc = NULL;
        int rv = restart;
-       int last_devnum = -1;
+       char last_devnm[32] = "";
 
        /* component_size is not meaningful for a container,
-        * so pass '-1' meaning 'no change'
+        * so pass '0' meaning 'no change'
         */
        if (!restart &&
-           reshape_super(st, -1, info->new_level,
+           reshape_super(st, 0, info->new_level,
                          info->new_layout, info->new_chunk,
                          info->array.raid_disks, info->delta_disks,
                          backup_file, devname, APPLY_METADATA_CHANGES,
-                         quiet)) {
+                         verbose)) {
                unfreeze(st);
                return 1;
        }
@@ -2718,15 +3483,19 @@ int reshape_container(char *container, char *devname,
         */
        ping_monitor(container);
 
-       switch (fork()) {
+       if (!forked && !freeze_reshape && !check_env("MDADM_NO_SYSTEMCTL"))
+               if (continue_via_systemd(container))
+                       return 0;
+
+       switch (forked ? 0 : fork()) {
        case -1: /* error */
                perror("Cannot fork to complete reshape\n");
                unfreeze(st);
                return 1;
        default: /* parent */
                if (!freeze_reshape)
-                       printf(Name ": multi-array reshape continues"
-                              " in background\n");
+                       printf("%s: multi-array reshape continues"
+                              " in background\n", Name);
                return 0;
        case 0: /* child */
                map_fork();
@@ -2754,6 +3523,7 @@ int reshape_container(char *container, char *devname,
                int fd;
                struct mdstat_ent *mdstat;
                char *adev;
+               int devid;
 
                sysfs_free(cc);
 
@@ -2765,13 +3535,12 @@ int reshape_container(char *container, char *devname,
                                continue;
 
                        subarray = strchr(content->text_version+1, '/')+1;
-                       mdstat = mdstat_by_subdev(subarray,
-                                                 devname2devnum(container));
+                       mdstat = mdstat_by_subdev(subarray, container);
                        if (!mdstat)
                                continue;
                        if (mdstat->active == 0) {
-                               fprintf(stderr, Name ": Skipping inactive "
-                                       "array md%i.\n", mdstat->devnum);
+                               pr_err("Skipping inactive array %s.\n",
+                                      mdstat->devnm);
                                free_mdstat(mdstat);
                                mdstat = NULL;
                                continue;
@@ -2781,20 +3550,18 @@ int reshape_container(char *container, char *devname,
                if (!content)
                        break;
 
-               adev = map_dev(dev2major(mdstat->devnum),
-                              dev2minor(mdstat->devnum),
-                              0);
+               devid = devnm2devid(mdstat->devnm);
+               adev = map_dev(major(devid), minor(devid), 0);
                if (!adev)
                        adev = content->text_version;
 
-               fd = open_dev(mdstat->devnum);
+               fd = open_dev(mdstat->devnm);
                if (fd < 0) {
-                       printf(Name ": Device %s cannot be opened for reshape.",
-                              adev);
+                       pr_err("Device %s cannot be opened for reshape.\n", adev);
                        break;
                }
 
-               if (last_devnum == mdstat->devnum) {
+               if (strcmp(last_devnm, mdstat->devnm) == 0) {
                        /* Do not allow for multiple reshape_array() calls for
                         * the same array.
                         * It can happen when reshape_array() returns without
@@ -2805,21 +3572,21 @@ int reshape_container(char *container, char *devname,
                         * This is possibly interim until the behaviour of
                         * reshape_array is resolved().
                         */
-                       printf(Name ": Multiple reshape execution detected for "
-                              "device  %s.", adev);
+                       printf("%s: Multiple reshape execution detected for "
+                              "device  %s.\n", Name, adev);
                        close(fd);
                        break;
                }
-               last_devnum = mdstat->devnum;
+               strcpy(last_devnm, mdstat->devnm);
 
-               sysfs_init(content, fd, mdstat->devnum);
+               sysfs_init(content, fd, mdstat->devnm);
 
-               if (mdmon_running(devname2devnum(container)))
+               if (mdmon_running(container))
                        flush_mdmon(container);
 
                rv = reshape_array(container, fd, adev, st,
-                                  content, force, NULL,
-                                  backup_file, quiet, 1, restart,
+                                  content, force, NULL, INVALID_SECTORS,
+                                  backup_file, verbose, 1, restart,
                                   freeze_reshape);
                close(fd);
 
@@ -2832,7 +3599,7 @@ int reshape_container(char *container, char *devname,
                if (rv)
                        break;
 
-               if (mdmon_running(devname2devnum(container)))
+               if (mdmon_running(container))
                        flush_mdmon(container);
        }
        if (!rv)
@@ -2869,7 +3636,7 @@ int progress_reshape(struct mdinfo *info, struct reshape *reshape,
                     unsigned long long backup_point,
                     unsigned long long wait_point,
                     unsigned long long *suspend_point,
-                    unsigned long long *reshape_completed)
+                    unsigned long long *reshape_completed, int *frozen)
 {
        /* This function is called repeatedly by the reshape manager.
         * It determines how much progress can safely be made and allows
@@ -3086,7 +3853,8 @@ int progress_reshape(struct mdinfo *info, struct reshape *reshape,
                wait_point = info->component_size - wait_point;
        }
 
-       sysfs_set_num(info, NULL, "sync_max", max_progress);
+       if (!*frozen)
+               sysfs_set_num(info, NULL, "sync_max", max_progress);
 
        /* Now wait.  If we have already reached the point that we were
         * asked to wait to, don't wait at all, else wait for any change.
@@ -3106,7 +3874,6 @@ int progress_reshape(struct mdinfo *info, struct reshape *reshape,
                 * waiting forever on a dead array
                 */
                char action[20];
-               fd_set rfds;
                if (sysfs_get_str(info, NULL, "sync_action",
                                  action, 20) <= 0 ||
                    strncmp(action, "reshape", 7) != 0)
@@ -3122,9 +3889,7 @@ int progress_reshape(struct mdinfo *info, struct reshape *reshape,
                    && info->reshape_progress < (info->component_size
                                                 * reshape->after.data_disks))
                        break;
-               FD_ZERO(&rfds);
-               FD_SET(fd, &rfds);
-               select(fd+1, NULL, NULL, &rfds, NULL);
+               sysfs_wait(fd, NULL);
                if (sysfs_fd_get_ll(fd, &completed) < 0)
                        goto check_progress;
        }
@@ -3169,23 +3934,24 @@ check_progress:
                /* The abort might only be temporary.  Wait up to 10
                 * seconds for fd to contain a valid number again.
                 */
-               struct timeval tv;
+               int wait = 10000;
                int rv = -2;
-               tv.tv_sec = 10;
-               tv.tv_usec = 0;
-               while (fd >= 0 && rv < 0 && tv.tv_sec > 0) {
-                       fd_set rfds;
-                       FD_ZERO(&rfds);
-                       FD_SET(fd, &rfds);
-                       if (select(fd+1, NULL, NULL, &rfds, &tv) != 1)
+               unsigned long long new_sync_max;
+               while (fd >= 0 && rv < 0 && wait > 0) {
+                       if (sysfs_wait(fd, &wait) != 1)
                                break;
                        switch (sysfs_fd_get_ll(fd, &completed)) {
                        case 0:
                                /* all good again */
                                rv = 1;
+                               /* If "sync_max" is no longer max_progress
+                                * we need to freeze things
+                                */
+                               sysfs_get_ll(info, NULL, "sync_max", &new_sync_max);
+                               *frozen = (new_sync_max != max_progress);
                                break;
                        case -2: /* read error - abort */
-                               tv.tv_sec = 0;
+                               wait = 0;
                                break;
                        }
                }
@@ -3435,8 +4201,8 @@ static void validate(int afd, int bfd, unsigned long long offset)
                        free(abuf);
                        free(bbuf);
                        abuflen = len;
-                       abuf = malloc(abuflen);
-                       bbuf = malloc(abuflen);
+                       abuf = xmalloc(abuflen);
+                       bbuf = xmalloc(abuflen);
                }
 
                lseek64(bfd, offset+__le64_to_cpu(bsb2.devstart2)*512, 0);
@@ -3477,6 +4243,7 @@ int child_monitor(int afd, struct mdinfo *sra, struct reshape *reshape,
        struct mdinfo *sd;
        unsigned long stripes;
        int uuid[4];
+       int frozen = 0;
 
        /* set up the backup-super-block.  This requires the
         * uuid from the array.
@@ -3498,7 +4265,7 @@ int child_monitor(int afd, struct mdinfo *sra, struct reshape *reshape,
                        break;
        }
        if (!sd) {
-               fprintf(stderr, Name ": Cannot find a superblock\n");
+               pr_err("Cannot find a superblock\n");
                return 0;
        }
 
@@ -3554,9 +4321,11 @@ int child_monitor(int afd, struct mdinfo *sra, struct reshape *reshape,
                                wait_point = __le64_to_cpu(bsb.arraystart2);
                }
 
+               reshape_completed = sra->reshape_progress;
                rv = progress_reshape(sra, reshape,
                                      backup_point, wait_point,
-                                     &suspend_point, &reshape_completed);
+                                     &suspend_point, &reshape_completed,
+                                     &frozen);
                /* external metadata would need to ping_monitor here */
                sra->reshape_progress = reshape_completed;
 
@@ -3582,7 +4351,8 @@ int child_monitor(int afd, struct mdinfo *sra, struct reshape *reshape,
                                forget_backup(dests, destfd,
                                              destoffsets, 1);
                }
-
+               if (sigterm)
+                       rv = -2;
                if (rv < 0) {
                        if (rv == -1)
                                done = 1;
@@ -3590,6 +4360,7 @@ int child_monitor(int afd, struct mdinfo *sra, struct reshape *reshape,
                }
                if (rv == 0 && increasing && !st->ss->external) {
                        /* No longer need to monitor this reshape */
+                       sysfs_set_str(sra, NULL, "sync_max", "max");
                        done = 1;
                        break;
                }
@@ -3643,7 +4414,12 @@ int child_monitor(int afd, struct mdinfo *sra, struct reshape *reshape,
        }
 
        /* FIXME maybe call progress_reshape one more time instead */
-       abort_reshape(sra); /* remove any remaining suspension */
+       /* remove any remaining suspension */
+       sysfs_set_num(sra, NULL, "suspend_lo", 0x7FFFFFFFFFFFFFFFULL);
+       sysfs_set_num(sra, NULL, "suspend_hi", 0);
+       sysfs_set_num(sra, NULL, "suspend_lo", 0);
+       sysfs_set_num(sra, NULL, "sync_min", 0);
+
        if (reshape->before.data_disks == reshape->after.data_disks)
                sysfs_set_num(sra, NULL, "sync_speed_min", speed);
        free(buf);
@@ -3693,7 +4469,7 @@ int Grow_restart(struct supertype *st, struct mdinfo *info, int *fdlist, int cnt
                if (i == old_disks-1) {
                        fd = open(backup_file, O_RDONLY);
                        if (fd<0) {
-                               fprintf(stderr, Name ": backup file %s inaccessible: %s\n",
+                               pr_err("backup file %s inaccessible: %s\n",
                                        backup_file, strerror(errno));
                                continue;
                        }
@@ -3711,7 +4487,7 @@ int Grow_restart(struct supertype *st, struct mdinfo *info, int *fdlist, int cnt
                        if (lseek64(fd,
                                    (dinfo.data_offset + dinfo.component_size - 8) <<9,
                                    0) < 0) {
-                               fprintf(stderr, Name ": Cannot seek on device %d\n", i);
+                               pr_err("Cannot seek on device %d\n", i);
                                continue; /* Cannot seek */
                        }
                        sprintf(namebuf, "device-%d", i);
@@ -3719,29 +4495,29 @@ int Grow_restart(struct supertype *st, struct mdinfo *info, int *fdlist, int cnt
                }
                if (read(fd, &bsb, sizeof(bsb)) != sizeof(bsb)) {
                        if (verbose)
-                               fprintf(stderr, Name ": Cannot read from %s\n", devname);
+                               pr_err("Cannot read from %s\n", devname);
                        continue; /* Cannot read */
                }
                if (memcmp(bsb.magic, "md_backup_data-1", 16) != 0 &&
                    memcmp(bsb.magic, "md_backup_data-2", 16) != 0) {
                        if (verbose)
-                               fprintf(stderr, Name ": No backup metadata on %s\n", devname);
+                               pr_err("No backup metadata on %s\n", devname);
                        continue;
                }
                if (bsb.sb_csum != bsb_csum((char*)&bsb, ((char*)&bsb.sb_csum)-((char*)&bsb))) {
                        if (verbose)
-                               fprintf(stderr, Name ": Bad backup-metadata checksum on %s\n", devname);
+                               pr_err("Bad backup-metadata checksum on %s\n", devname);
                        continue; /* bad checksum */
                }
                if (memcmp(bsb.magic, "md_backup_data-2", 16) == 0 &&
                    bsb.sb_csum2 != bsb_csum((char*)&bsb, ((char*)&bsb.sb_csum2)-((char*)&bsb))) {
                        if (verbose)
-                               fprintf(stderr, Name ": Bad backup-metadata checksum2 on %s\n", devname);
+                               pr_err("Bad backup-metadata checksum2 on %s\n", devname);
                        continue; /* Bad second checksum */
                }
                if (memcmp(bsb.set_uuid,info->uuid, 16) != 0) {
                        if (verbose)
-                               fprintf(stderr, Name ": Wrong uuid on backup-metadata on %s\n", devname);
+                               pr_err("Wrong uuid on backup-metadata on %s\n", devname);
                        continue; /* Wrong uuid */
                }
 
@@ -3752,14 +4528,13 @@ int Grow_restart(struct supertype *st, struct mdinfo *info, int *fdlist, int cnt
                if (info->array.utime > (int)__le64_to_cpu(bsb.mtime) + 2*60*60 ||
                    info->array.utime < (int)__le64_to_cpu(bsb.mtime) - 10*60) {
                        if (check_env("MDADM_GROW_ALLOW_OLD")) {
-                               fprintf(stderr, Name ": accepting backup with timestamp %lu "
+                               pr_err("accepting backup with timestamp %lu "
                                        "for array with timestamp %lu\n",
                                        (unsigned long)__le64_to_cpu(bsb.mtime),
                                        (unsigned long)info->array.utime);
                        } else {
-                               if (verbose)
-                                       fprintf(stderr, Name ": too-old timestamp on "
-                                               "backup-metadata on %s\n", devname);
+                               pr_err("too-old timestamp on backup-metadata on %s\n", devname);
+                               pr_err("If you think it is should be safe, try 'export MDADM_GROW_ALLOW_OLD=1'\n");
                                continue; /* time stamp is too bad */
                        }
                }
@@ -3774,8 +4549,7 @@ int Grow_restart(struct supertype *st, struct mdinfo *info, int *fdlist, int cnt
                                    < info->reshape_progress) {
                                nonew:
                                        if (verbose)
-                                               fprintf(stderr, Name
-                                                       ": backup-metadata found on %s but is not needed\n", devname);
+                                               pr_err("backup-metadata found on %s but is not needed\n", devname);
                                        continue; /* No new data here */
                                }
                        } else {
@@ -3809,9 +4583,8 @@ int Grow_restart(struct supertype *st, struct mdinfo *info, int *fdlist, int cnt
                if (lseek64(fd, __le64_to_cpu(bsb.devstart)*512, 0)< 0) {
                second_fail:
                        if (verbose)
-                               fprintf(stderr, Name
-                                       ": Failed to verify secondary backup-metadata block on %s\n",
-                                       devname);
+                               pr_err("Failed to verify secondary backup-metadata block on %s\n",
+                                      devname);
                        continue; /* Cannot seek */
                }
                /* There should be a duplicate backup superblock 4k before here */
@@ -3826,7 +4599,7 @@ int Grow_restart(struct supertype *st, struct mdinfo *info, int *fdlist, int cnt
                        goto second_fail; /* Cannot find leading superblock */
 
                /* Now need the data offsets for all devices. */
-               offsets = malloc(sizeof(*offsets)*info->array.raid_disks);
+               offsets = xmalloc(sizeof(*offsets)*info->array.raid_disks);
                for(j=0; j<info->array.raid_disks; j++) {
                        if (fdlist[j] < 0)
                                continue;
@@ -3837,7 +4610,7 @@ int Grow_restart(struct supertype *st, struct mdinfo *info, int *fdlist, int cnt
                        st->ss->free_super(st);
                        offsets[j] = dinfo.data_offset * 512;
                }
-               printf(Name ": restoring critical section\n");
+               printf("%s: restoring critical section\n", Name);
 
                if (restore_stripes(fdlist, offsets,
                                    info->array.raid_disks,
@@ -3849,7 +4622,7 @@ int Grow_restart(struct supertype *st, struct mdinfo *info, int *fdlist, int cnt
                                    __le64_to_cpu(bsb.length)*512, NULL)) {
                        /* didn't succeed, so giveup */
                        if (verbose)
-                               fprintf(stderr, Name ": Error restoring backup from %s\n",
+                               pr_err("Error restoring backup from %s\n",
                                        devname);
                        free(offsets);
                        return 1;
@@ -3867,7 +4640,7 @@ int Grow_restart(struct supertype *st, struct mdinfo *info, int *fdlist, int cnt
                                    __le64_to_cpu(bsb.length2)*512, NULL)) {
                        /* didn't succeed, so giveup */
                        if (verbose)
-                               fprintf(stderr, Name ": Error restoring second backup from %s\n",
+                               pr_err("Error restoring second backup from %s\n",
                                        devname);
                        free(offsets);
                        return 1;
@@ -3916,7 +4689,8 @@ int Grow_restart(struct supertype *st, struct mdinfo *info, int *fdlist, int cnt
                        }
                }
                for (j=0; j<info->array.raid_disks; j++) {
-                       if (fdlist[j] < 0) continue;
+                       if (fdlist[j] < 0)
+                               continue;
                        if (st->ss->load_super(st, fdlist[j], NULL))
                                continue;
                        st->ss->getinfo_super(st, &dinfo, NULL);
@@ -3966,7 +4740,7 @@ int Grow_restart(struct supertype *st, struct mdinfo *info, int *fdlist, int cnt
        }
        /* needed to recover critical section! */
        if (verbose)
-               fprintf(stderr, Name ": Failed to find backup of critical section\n");
+               pr_err("Failed to find backup of critical section\n");
        return 1;
 }
 
@@ -3980,7 +4754,6 @@ int Grow_continue_command(char *devname, int fd,
        char *subarray = NULL;
        struct mdinfo *cc = NULL;
        struct mdstat_ent *mdstat = NULL;
-       char buf[40];
        int cfd = -1;
        int fd2 = -1;
 
@@ -3989,51 +4762,84 @@ int Grow_continue_command(char *devname, int fd,
 
        st = super_by_fd(fd, &subarray);
        if (!st || !st->ss) {
-               fprintf(stderr,
-                       Name ": Unable to determine metadata format for %s\n",
-                       devname);
+               pr_err("Unable to determine metadata format for %s\n",
+                      devname);
                return 1;
        }
        dprintf("Grow continue is run for ");
        if (st->ss->external == 0) {
-               dprintf("native array (%s)\n", devname);
-               if (ioctl(fd, GET_ARRAY_INFO, &array) < 0) {
-                       fprintf(stderr, Name ": %s is not an active md array -"
+               int d;
+               dprintf_cont("native array (%s)\n", devname);
+               if (ioctl(fd, GET_ARRAY_INFO, &array.array) < 0) {
+                       pr_err("%s is not an active md array -"
                                " aborting\n", devname);
                        ret_val = 1;
                        goto Grow_continue_command_exit;
                }
                content = &array;
-               sysfs_init(content, fd, st->devnum);
+               /* Need to load a superblock.
+                * FIXME we should really get what we need from
+                * sysfs
+                */
+               for (d = 0; d < MAX_DISKS; d++) {
+                       mdu_disk_info_t disk;
+                       char *dv;
+                       int err;
+                       disk.number = d;
+                       if (ioctl(fd, GET_DISK_INFO, &disk) < 0)
+                               continue;
+                       if (disk.major == 0 && disk.minor == 0)
+                               continue;
+                       if ((disk.state & (1 << MD_DISK_ACTIVE)) == 0)
+                               continue;
+                       dv = map_dev(disk.major, disk.minor, 1);
+                       if (!dv)
+                               continue;
+                       fd2 = dev_open(dv, O_RDONLY);
+                       if (fd2 < 0)
+                               continue;
+                       err = st->ss->load_super(st, fd2, NULL);
+                       close(fd2);
+                       /* invalidate fd2 to avoid possible double close() */
+                       fd2 = -1;
+                       if (err)
+                               continue;
+                       break;
+               }
+               if (d == MAX_DISKS) {
+                       pr_err("Unable to load metadata for %s\n",
+                              devname);
+                       ret_val = 1;
+                       goto Grow_continue_command_exit;
+               }
+               st->ss->getinfo_super(st, content, NULL);
        } else {
-               int container_dev;
+               char *container;
 
                if (subarray) {
-                       dprintf("subarray (%s)\n", subarray);
-                       container_dev = st->container_dev;
-                       cfd = open_dev_excl(st->container_dev);
+                       dprintf_cont("subarray (%s)\n", subarray);
+                       container = st->container_devnm;
+                       cfd = open_dev_excl(st->container_devnm);
                } else {
-                       container_dev = st->devnum;
+                       container = st->devnm;
                        close(fd);
-                       cfd = open_dev_excl(st->devnum);
-                       dprintf("container (%i)\n", container_dev);
+                       cfd = open_dev_excl(st->devnm);
+                       dprintf_cont("container (%s)\n", container);
                        fd = cfd;
                }
                if (cfd < 0) {
-                       fprintf(stderr, Name ": Unable to open container "
+                       pr_err("Unable to open container "
                                "for %s\n", devname);
                        ret_val = 1;
                        goto Grow_continue_command_exit;
                }
-               fmt_devname(buf, container_dev);
 
                /* find in container array under reshape
                 */
                ret_val = st->ss->load_container(st, cfd, NULL);
                if (ret_val) {
-                       fprintf(stderr,
-                               Name ": Cannot read superblock for %s\n",
-                               devname);
+                       pr_err("Cannot read superblock for %s\n",
+                              devname);
                        ret_val = 1;
                        goto Grow_continue_command_exit;
                }
@@ -4059,22 +4865,21 @@ int Grow_continue_command(char *devname, int fd,
                                allow_reshape = 0;
 
                        if (!allow_reshape) {
-                               fprintf(stderr, Name
-                                       ": cannot continue reshape of an array"
-                                       " in container with unsupported"
-                                       " metadata: %s(%s)\n",
-                                       devname, buf);
+                               pr_err("cannot continue reshape of an array"
+                                      " in container with unsupported"
+                                      " metadata: %s(%s)\n",
+                                      devname, container);
                                ret_val = 1;
                                goto Grow_continue_command_exit;
                        }
 
                        array = strchr(content->text_version+1, '/')+1;
-                       mdstat = mdstat_by_subdev(array, container_dev);
+                       mdstat = mdstat_by_subdev(array, container);
                        if (!mdstat)
                                continue;
                        if (mdstat->active == 0) {
-                               fprintf(stderr, Name ": Skipping inactive "
-                                       "array md%i.\n", mdstat->devnum);
+                               pr_err("Skipping inactive array %s.\n",
+                                      mdstat->devnm);
                                free_mdstat(mdstat);
                                mdstat = NULL;
                                continue;
@@ -4082,32 +4887,30 @@ int Grow_continue_command(char *devname, int fd,
                        break;
                }
                if (!content) {
-                       fprintf(stderr,
-                               Name ": Unable to determine reshaped "
-                               "array for %s\n", devname);
+                       pr_err("Unable to determine reshaped "
+                              "array for %s\n", devname);
                        ret_val = 1;
                        goto Grow_continue_command_exit;
                }
-               fd2 = open_dev(mdstat->devnum);
+               fd2 = open_dev(mdstat->devnm);
                if (fd2 < 0) {
-                       fprintf(stderr, Name ": cannot open (md%i)\n",
-                               mdstat->devnum);
+                       pr_err("cannot open (%s)\n", mdstat->devnm);
                        ret_val = 1;
                        goto Grow_continue_command_exit;
                }
 
-               sysfs_init(content, fd2, mdstat->devnum);
+               sysfs_init(content, fd2, mdstat->devnm);
 
                /* start mdmon in case it is not running
                 */
-               if (!mdmon_running(container_dev))
-                       start_mdmon(container_dev);
-               ping_monitor(buf);
+               if (!mdmon_running(container))
+                       start_mdmon(container);
+               ping_monitor(container);
 
-               if (mdmon_running(container_dev))
+               if (mdmon_running(container))
                        st->update_tail = &st->updates;
                else {
-                       fprintf(stderr, Name ":  No mdmon found. "
+                       pr_err("No mdmon found. "
                                "Grow cannot continue.\n");
                        ret_val = 1;
                        goto Grow_continue_command_exit;
@@ -4117,15 +4920,14 @@ int Grow_continue_command(char *devname, int fd,
        /* verify that array under reshape is started from
         * correct position
         */
-       if (verify_reshape_position(content,
-                                   map_name(pers, mdstat->level)) < 0) {
+       if (verify_reshape_position(content, content->array.level) < 0) {
                ret_val = 1;
                goto Grow_continue_command_exit;
        }
 
        /* continue reshape
         */
-       ret_val = Grow_continue(fd, st, content, backup_file, 0);
+       ret_val = Grow_continue(fd, st, content, backup_file, 1, 0);
 
 Grow_continue_command_exit:
        if (fd2 > -1)
@@ -4141,7 +4943,7 @@ Grow_continue_command_exit:
 }
 
 int Grow_continue(int mdfd, struct supertype *st, struct mdinfo *info,
-                 char *backup_file, int freeze_reshape)
+                 char *backup_file, int forked, int freeze_reshape)
 {
        int ret_val = 2;
 
@@ -4149,22 +4951,49 @@ int Grow_continue(int mdfd, struct supertype *st, struct mdinfo *info,
                return ret_val;
 
        if (st->ss->external) {
-               char container[40];
-               int cfd = open_dev(st->container_dev);
+               int cfd = open_dev(st->container_devnm);
 
                if (cfd < 0)
                        return 1;
 
-               fmt_devname(container, st->container_dev);
-               st->ss->load_container(st, cfd, container);
+               st->ss->load_container(st, cfd, st->container_devnm);
                close(cfd);
-               ret_val = reshape_container(container, NULL, mdfd,
+               ret_val = reshape_container(st->container_devnm, NULL, mdfd,
                                            st, info, 0, backup_file,
-                                           0, 1, freeze_reshape);
+                                           0, forked,
+                                           1 | info->reshape_active,
+                                           freeze_reshape);
        } else
                ret_val = reshape_array(NULL, mdfd, "array", st, info, 1,
-                                       NULL, backup_file, 0, 0, 1,
+                                       NULL, INVALID_SECTORS,
+                                       backup_file, 0, forked,
+                                       1 | info->reshape_active,
                                        freeze_reshape);
 
        return ret_val;
 }
+
+char *make_backup(char *name)
+{
+       char *base = "backup_file-";
+       int len;
+       char *fname;
+
+       len = strlen(MAP_DIR) + 1 + strlen(base) + strlen(name)+1;
+       fname = xmalloc(len);
+       sprintf(fname, "%s/%s%s", MAP_DIR, base, name);
+       return fname;
+}
+
+char *locate_backup(char *name)
+{
+       char *fl = make_backup(name);
+       struct stat stb;
+
+       if (stat(fl, &stb) == 0 &&
+           S_ISREG(stb.st_mode))
+               return fl;
+
+       free(fl);
+       return NULL;
+}