MDADM:Check mdinfo->reshape_active more times before calling Grow_continue

When reshaping a 3 drives raid5 to 4 drives raid5, there is a chance that
it can't start the reshape. If the disks are not enough to have spaces for
relocating the data_offset, it needs to call start_reshape and then run
mdadm --grow --continue by systemd. But mdadm --grow --continue fails
because it checkes that info->reshape_active is 0.

The info->reshape_active is got from the superblock of underlying devices.
Function start_reshape write reshape to /sys/../sync_action. Before writing
latest superblock to underlying devices, mdadm --grow --continue is called.
There is a chance info->reshape_active is 0. We should wait for superblock
updating more time before calling Grow_continue.

Signed-off-by: Xiao Ni <xni@redhat.com>
Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>

diff --git a/Grow.c b/Grow.c
index f184d9c4e988a6be9d444407ec2adc7766413d5f..628f0e74d047880ab4fcdd35e8dc1a08c821e27b 100755 (executable)
--- a/Grow.c
+++ b/Grow.c
@@ -4788,6 +4788,7 @@ int Grow_continue_command(char *devname, int fd,
        dprintf("Grow continue is run for ");
        if (st->ss->external == 0) {
                int d;
+               int cnt = 5;
                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);
@@ -4799,36 +4800,42 @@ int Grow_continue_command(char *devname, int fd,
                 * 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);
-                       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);
+               do {
+                       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);
+                               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);
+                       if (!content->reshape_active)
+                               sleep(3);
+                       else
+                               break;
+               } while (cnt-- > 0);
        } else {
                char *container;