ddf: prevent superblock being zeroed on --update

The full fix would be to support updating ddf metadata, but this minimal
fix just prevents the superblock from being zeroed when someone
inadvertently passes an unsupported --update option during assembly.

Reported-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

diff --git a/super-ddf.c b/super-ddf.c
index 9bf08c2c9428512d9a1ff0da17e5712372e1d792..06858e23fb9cbc3f0fc94874c2b9905d9a6ca73a 100644 (file)
--- a/super-ddf.c
+++ b/super-ddf.c
@@ -1589,13 +1589,8 @@ static int init_super_ddf(struct supertype *st,
        struct phys_disk *pd;
        struct virtual_disk *vd;
 
-       if (!info) {
-               st->sb = NULL;
-               return 0;
-       }
        if (st->sb)
-               return init_super_ddf_bvd(st, info, size, name, homehost,
-                                         uuid);
+               return init_super_ddf_bvd(st, info, size, name, homehost, uuid);
 
        if (posix_memalign((void**)&ddf, 512, sizeof(*ddf)) != 0) {
                fprintf(stderr, Name ": %s could not allocate superblock\n", __func__);
@@ -1604,6 +1599,12 @@ static int init_super_ddf(struct supertype *st,
        memset(ddf, 0, sizeof(*ddf));
        ddf->dlist = NULL; /* no physical disks yet */
        ddf->conflist = NULL; /* No virtual disks yet */
+       st->sb = ddf;
+
+       if (info == NULL) {
+               /* zeroing superblock */
+               return 0;
+       }
 
        /* At least 32MB *must* be reserved for the ddf.  So let's just
         * start 32MB from the end, and put the primary header there.
@@ -2971,12 +2972,22 @@ static struct mdinfo *container_content_ddf(struct supertype *st)
        return rest;
 }
 
-static int store_zero_ddf(struct supertype *st, int fd)
+static int store_super_ddf(struct supertype *st, int fd)
 {
+       struct ddf_super *ddf = st->sb;
        unsigned long long dsize;
        void *buf;
        int rc;
 
+       if (!ddf)
+               return 1;
+
+       /* ->dlist and ->conflist will be set for updates, currently not
+        * supported
+        */
+       if (ddf->dlist || ddf->conflist)
+               return 1;
+
        if (!get_dev_size(fd, NULL, &dsize))
                return 1;
 
@@ -3627,7 +3638,7 @@ struct superswitch super_ddf = {
 
        .load_super     = load_super_ddf,
        .init_super     = init_super_ddf,
-       .store_super    = store_zero_ddf,
+       .store_super    = store_super_ddf,
        .free_super     = free_super_ddf,
        .match_metadata_desc = match_metadata_desc_ddf,
        .container_content = container_content_ddf,