util-linux/2.25-libfdisk-gpt-recovery....

123 lines
4.0 KiB
Diff

diff -up util-linux-2.24/libfdisk/src/gpt.c.kzak util-linux-2.24/libfdisk/src/gpt.c
--- util-linux-2.24/libfdisk/src/gpt.c.kzak 2013-10-21 13:03:38.782957983 +0200
+++ util-linux-2.24/libfdisk/src/gpt.c 2013-10-23 12:16:01.062783977 +0200
@@ -410,6 +410,46 @@ static int gpt_mknew_header_from_bkp(str
return 0;
}
+static struct gpt_header *gpt_copy_header(struct fdisk_context *cxt,
+ struct gpt_header *src)
+{
+ struct gpt_header *res;
+
+ if (!cxt || !src)
+ return NULL;
+
+ res = calloc(1, sizeof(*res));
+ if (!res) {
+ fdisk_warn(cxt, _("failed to allocate GPT header"));
+ return NULL;
+ }
+
+ res->my_lba = src->alternative_lba;
+ res->alternative_lba = src->my_lba;
+
+ res->signature = src->signature;
+ res->revision = src->revision;
+ res->size = src->size;
+ res->npartition_entries = src->npartition_entries;
+ res->sizeof_partition_entry = src->sizeof_partition_entry;
+ res->first_usable_lba = src->first_usable_lba;
+ res->last_usable_lba = src->last_usable_lba;
+
+ memcpy(&res->disk_guid, &src->disk_guid, sizeof(src->disk_guid));
+
+
+ if (res->my_lba == GPT_PRIMARY_PARTITION_TABLE_LBA)
+ res->partition_entry_lba = cpu_to_le64(2);
+ else {
+ uint64_t esz = le32_to_cpu(src->npartition_entries) * sizeof(struct gpt_entry);
+ uint64_t esects = (esz + cxt->sector_size - 1) / cxt->sector_size;
+
+ res->partition_entry_lba = cpu_to_le64(cxt->total_sectors - 1 - esects);
+ }
+
+ return res;
+}
+
/*
* Builds a clean new GPT header (currently under revision 1.0).
*
@@ -776,10 +816,13 @@ static struct gpt_header *gpt_read_heade
else
free(ents);
+ DBG(LABEL, dbgprint("found valid GPT Header on LBA %ju", lba));
return header;
invalid:
free(header);
free(ents);
+
+ DBG(LABEL, dbgprint("read GPT Header on LBA %ju failed", lba));
return NULL;
}
@@ -1091,6 +1134,8 @@ static int gpt_probe_label(struct fdisk_
gpt = self_label(cxt);
+ /* TODO: it would be nice to support scenario when GPT headers are OK,
+ * but PMBR is corrupt */
mbr_type = valid_pmbr(cxt);
if (!mbr_type)
goto failed;
@@ -1102,20 +1147,36 @@ static int gpt_probe_label(struct fdisk_
gpt->pheader = gpt_read_header(cxt, GPT_PRIMARY_PARTITION_TABLE_LBA,
&gpt->ents);
- /*
- * TODO: If the primary GPT is corrupt, we must check the last LBA of the
- * device to see if it has a valid GPT Header and point to a valid GPT
- * Partition Entry Array.
- * If it points to a valid GPT Partition Entry Array, then software should
- * restore the primary GPT if allowed by platform policy settings.
- *
- * For now we just abort GPT probing!
- */
- if (!gpt->pheader || !gpt->ents)
+ if (gpt->pheader)
+ /* primary OK, try backup from alternative LBA */
+ gpt->bheader = gpt_read_header(cxt,
+ le64_to_cpu(gpt->pheader->alternative_lba),
+ NULL);
+ else
+ /* primary corrupted -- try last LBA */
+ gpt->bheader = gpt_read_header(cxt, last_lba(cxt), &gpt->ents);
+
+ if (!gpt->pheader && !gpt->bheader)
goto failed;
- /* OK, probing passed, now initialize backup header and fdisk variables. */
- gpt->bheader = gpt_read_header(cxt, last_lba(cxt), NULL);
+ /* primary OK, backup corrupted -- recovery */
+ if (gpt->pheader && !gpt->bheader) {
+ fdisk_warnx(cxt, _("The backup GPT table is corrupt, but the "
+ "primary appears OK, so that will be used."));
+ gpt->bheader = gpt_copy_header(cxt, gpt->pheader);
+ if (!gpt->bheader)
+ goto failed;
+ gpt_recompute_crc(gpt->bheader, gpt->ents);
+
+ /* primary corrupted, backup OK -- recovery */
+ } else if (!gpt->pheader && gpt->bheader) {
+ fdisk_warnx(cxt, _("The primary GPT table is corrupt, but the "
+ "backup appears OK, so that will be used."));
+ gpt->pheader = gpt_copy_header(cxt, gpt->bheader);
+ if (!gpt->pheader)
+ goto failed;
+ gpt_recompute_crc(gpt->pheader, gpt->ents);
+ }
cxt->label->nparts_max = le32_to_cpu(gpt->pheader->npartition_entries);
cxt->label->nparts_cur = partitions_in_use(gpt->pheader, gpt->ents);