Manage: allow --re-add to failed array.

If both "legs" of a RAID1 (or equivalent in RAID10) fail, then one
of the becomes available again it maybe appropriate to re-add the
failed device(s).
So remove the restriction that an array must has 'enough' devices
before being re-added, and if there is no-where to read a superblock
from for matching, then assume the kernel will do necessary checks.

Signed-off-by: NeilBrown <neilb@suse.de>

diff --git a/Manage.c b/Manage.c
index d9775ded855554a95ec8a286dc743d930dfba330..4cf6e587278b7becf19f40f41b377d67ca86d6df 100644 (file)
--- a/Manage.c
+++ b/Manage.c
@@ -723,7 +723,13 @@ int Manage_subdevs(char *devname, int fd,
                                        break;
                                }
                                /* FIXME this is a bad test to be using */
-                               if (!tst->sb) {
+                               if (!tst->sb &&
+                                   dv->re_add) {
+                                       /* we are re-adding a device to a
+                                        * completely dead array - have to depend
+                                        * on kernel to check
+                                        */
+                               } else if (!tst->sb) {
                                        close(tfd);
                                        st->ss->free_super(st);
                                        fprintf(stderr, Name ": cannot load array metadata from %s\n", devname);
@@ -747,12 +753,16 @@ int Manage_subdevs(char *devname, int fd,
                                 * and was temporarily removed, and is now being re-added.
                                 * If so, we can simply re-add it.
                                 */
-                               tst->ss->uuid_from_super(tst, duuid);
 
                                if (st->sb) {
                                        struct mdinfo mdi;
                                        st->ss->getinfo_super(st, &mdi, NULL);
                                        st->ss->uuid_from_super(st, ouuid);
+                                       if (tst->sb)
+                                               tst->ss->uuid_from_super(tst, duuid);
+                                       else
+                                               /* Assume uuid matches: kernel will check */
+                                               memcpy(duuid, ouuid, sizeof(ouuid));
                                        if ((mdi.disk.state & (1<<MD_DISK_ACTIVE)) &&
                                            !(mdi.disk.state & (1<<MD_DISK_FAULTY)) &&
                                            memcmp(duuid, ouuid, sizeof(ouuid))==0) {
@@ -768,7 +778,7 @@ int Manage_subdevs(char *devname, int fd,
                                                disc.number = mdi.disk.number;
                                                if (ioctl(fd, GET_DISK_INFO, &disc) != 0
                                                    || disc.major != 0 || disc.minor != 0
-                                                   || !enough_fd(fd))
+                                                       )
                                                        goto skip_re_add;
                                                disc.major = major(stb.st_rdev);
                                                disc.minor = minor(stb.st_rdev);