On Mon, 9 Sep 2013 20:40:14 +0200 mwilck@xxxxxxxx wrote:
> Some fake RAID BIOSes (in particular, LSI ones) change the
> VD GUID at every boot. These GUIDs are not suitable for
> identifying an array. Luckily the header GUID appears to
> remain constant.
>
> We construct a pseudo-UUID from the header GUID and those
> properties of the subarray that we expect to remain constant.
> This is only array name and index; all else might change e.g.
> during grow.
>
> Don't do this for all non-MD arrays, only for those known
> to use varying volume GUIDs.
>
> This patch obsoletes my previous patch "DDF: new algorithm
> for subarray UUID"
>
> Signed-off-by: Martin Wilck <mwilck@xxxxxxxx>
Thanks. Applied.
NeilBrown
> ---
> super-ddf.c | 55 ++++++++++++++++++++++++++++++++++++++++++++++++++-----
> 1 files changed, 50 insertions(+), 5 deletions(-)
>
> diff --git a/super-ddf.c b/super-ddf.c
> index 72a8351..19d8494 100644
> --- a/super-ddf.c
> +++ b/super-ddf.c
> @@ -1583,6 +1583,7 @@ static void brief_examine_subarrays_ddf(struct supertype *st, int verbose)
> continue;
> memcpy(vcl.conf.guid, ve->guid, DDF_GUID_LEN);
> ddf->currentconf =&vcl;
> + vcl.vcnum = i;
> uuid_from_super_ddf(st, info.uuid);
> fname_from_uuid(st, &info, nbuf1, ':');
> memcpy(namebuf, ve->name, sizeof(ve->name));
> @@ -1682,6 +1683,52 @@ static void detail_super_ddf(struct supertype *st, char *homehost)
> */
> }
>
> +static const char *vendors_with_variable_volume_UUID[] = {
> + "LSI ",
> +};
> +
> +static int volume_id_is_reliable(const struct ddf_super *ddf)
> +{
> + int n = sizeof(vendors_with_variable_volume_UUID) /
> + sizeof(vendors_with_variable_volume_UUID[0]);
> + int i;
> + for (i = 0; i < n; i++)
> + if (!memcmp(ddf->controller.guid,
> + vendors_with_variable_volume_UUID[i], 8))
> + return 0;
> + return 1;
> +}
> +
> +static void uuid_of_ddf_subarray(const struct ddf_super *ddf,
> + unsigned int vcnum, int uuid[4])
> +{
> + char buf[DDF_GUID_LEN+18], sha[20], *p;
> + struct sha1_ctx ctx;
> + if (volume_id_is_reliable(ddf)) {
> + uuid_from_ddf_guid(ddf->virt->entries[vcnum].guid, uuid);
> + return;
> + }
> + /*
> + * Some fake RAID BIOSes (in particular, LSI ones) change the
> + * VD GUID at every boot. These GUIDs are not suitable for
> + * identifying an array. Luckily the header GUID appears to
> + * remain constant.
> + * We construct a pseudo-UUID from the header GUID and those
> + * properties of the subarray that we expect to remain constant.
> + */
> + memset(buf, 0, sizeof(buf));
> + p = buf;
> + memcpy(p, ddf->anchor.guid, DDF_GUID_LEN);
> + p += DDF_GUID_LEN;
> + memcpy(p, ddf->virt->entries[vcnum].name, 16);
> + p += 16;
> + *((__u16 *) p) = vcnum;
> + sha1_init_ctx(&ctx);
> + sha1_process_bytes(buf, sizeof(buf), &ctx);
> + sha1_finish_ctx(&ctx, sha);
> + memcpy(uuid, sha, 4*4);
> +}
> +
> static void brief_detail_super_ddf(struct supertype *st)
> {
> struct mdinfo info;
> @@ -1693,7 +1740,7 @@ static void brief_detail_super_ddf(struct supertype *st)
> else if (vcnum == DDF_NOTFOUND)
> return;
> else
> - uuid_from_ddf_guid(ddf->virt->entries[vcnum].guid, info.uuid);
> + uuid_of_ddf_subarray(ddf, vcnum, info.uuid);
> fname_from_uuid(st, &info, nbuf,':');
> printf(" UUID=%s", nbuf + 5);
> }
> @@ -1836,13 +1883,11 @@ static void uuid_from_super_ddf(struct supertype *st, int uuid[4])
> */
> struct ddf_super *ddf = st->sb;
> struct vcl *vcl = ddf->currentconf;
> - char *guid;
>
> if (vcl)
> - guid = vcl->conf.guid;
> + uuid_of_ddf_subarray(ddf, vcl->vcnum, uuid);
> else
> - guid = ddf->anchor.guid;
> - uuid_from_ddf_guid(guid, uuid);
> + uuid_from_ddf_guid(ddf->anchor.guid, uuid);
> }
>
> static void getinfo_super_ddf_bvd(struct supertype *st, struct mdinfo *info, char *map);
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