From f43f5b32991c7f5a188940b00989c27f87feee81 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Wed, 2 Apr 2014 15:26:35 +1100 Subject: [PATCH 4/4] DDF: Don't fail compare_super_ddf due to re-configure changes. It is possible that one device has seem some reconfig but the other hasn't. In that case they are still the "same" DDF, even though one might be older. Such age will be detected by 'seq' differences. If A is new and B is old, then it is import that mdadm -I B mdadm -I A doesn't get confused because A has the same uuid as B, but compare_super fails. So: if the seq numbers are different, then just accept as two different superblocks. If they are the same, then look to copy data from new to old. Signed-off-by: NeilBrown --- super-ddf.c | 44 +++++++++++--------------------------------- 1 file changed, 11 insertions(+), 33 deletions(-) --- mdadm-3.3.orig/super-ddf.c +++ mdadm-3.3/super-ddf.c @@ -3937,47 +3937,25 @@ static int compare_super_ddf(struct supe if (memcmp(first->anchor.guid, second->anchor.guid, DDF_GUID_LEN) != 0) return 2; - if (first->max_part != second->max_part || - !be16_eq(first->phys->used_pdes, second->phys->used_pdes) || - !be16_eq(first->virt->populated_vdes, - second->virt->populated_vdes)) { - dprintf("%s: PD/VD number mismatch\n", __func__); - return 3; - } + /* It is only OK to compare info in the anchor. Anything else + * could be changing due to a reconfig so must be ignored. + * guid really should be enough anyway. + */ - max_pds = be16_to_cpu(first->phys->used_pdes); - for (dl2 = second->dlist; dl2; dl2 = dl2->next) { - for (pd = 0; pd < max_pds; pd++) - if (be32_eq(first->phys->entries[pd].refnum, - dl2->disk.refnum)) - break; - if (pd == max_pds) { - dprintf("%s: no match for disk %08x\n", __func__, - be32_to_cpu(dl2->disk.refnum)); - return 3; - } + if (!be32_eq(first->active->seq, second->active->seq)) { + dprintf("%s: sequence number mismatch %u<->%u\n", __func__, + be32_to_cpu(first->active->seq), + be32_to_cpu(second->active->seq)); + return 0; } - max_vds = be16_to_cpu(first->active->max_vd_entries); - for (vl2 = second->conflist; vl2; vl2 = vl2->next) { - if (!be32_eq(vl2->conf.magic, DDF_VD_CONF_MAGIC)) - continue; - for (vd = 0; vd < max_vds; vd++) - if (!memcmp(first->virt->entries[vd].guid, - vl2->conf.guid, DDF_GUID_LEN)) - break; - if (vd == max_vds) { - dprintf("%s: no match for VD config\n", __func__); - return 3; - } - } - /* FIXME should I look at anything else? */ - /* At this point we are fairly sure that the meta data matches. But the new disk may contain additional local data. Add it to the super block. */ + max_vds = be16_to_cpu(first->active->max_vd_entries); + max_pds = be16_to_cpu(first->phys->used_pdes); for (vl2 = second->conflist; vl2; vl2 = vl2->next) { for (vl1 = first->conflist; vl1; vl1 = vl1->next) if (!memcmp(vl1->conf.guid, vl2->conf.guid,