diff options
| -rw-r--r-- | sys/geom/geom_gpt.c | 41 |
1 files changed, 21 insertions, 20 deletions
diff --git a/sys/geom/geom_gpt.c b/sys/geom/geom_gpt.c index 24aa3c9..92b8371 100644 --- a/sys/geom/geom_gpt.c +++ b/sys/geom/geom_gpt.c @@ -931,26 +931,6 @@ g_gpt_taste(struct g_class *mp, struct g_provider *pp, int insist __unused) g_topology_assert(); /* - * Sanity-check the provider. Since the first sector on the provider - * must be a PMBR and a PMBR is 512 bytes large, the sector size must - * be at least 512 bytes. We also require that the sector size is a - * multiple of the GPT entry size (which is 128 bytes). - * Also, since the theoretical minimum number of sectors needed by - * GPT is 6, any medium that has less than 6 sectors is never going - * to hold a GPT. The number 6 comes from: - * 1 sector for the PMBR - * 2 sectors for the GPT headers (each 1 sector) - * 2 sectors for the GPT tables (each 1 sector) - * 1 sector for an actual partition - * It's better to catch this pathological case early than behaving - * pathologically later on by panicing... - */ - if (pp->sectorsize < 512 || - pp->sectorsize % sizeof(struct gpt_ent) != 0 || - pp->mediasize < 6 * pp->sectorsize) - return (NULL); - - /* * We don't nest. That is, we disallow nesting a GPT inside a GPT * partition. We check only for direct nesting. Indirect nesting is * not easy to determine. If you want, you can therefore nest GPT @@ -981,6 +961,27 @@ g_gpt_taste(struct g_class *mp, struct g_provider *pp, int insist __unused) g_topology_unlock(); /* + * Now that we have access permissions, we can sanity-check the + * provider. Since the first sector on the provider must be a PMBR + * and a PMBR is 512 bytes large, the sector size must be at least + * 512 bytes. We also require that the sector size is a multiple + * of the GPT entry size (which is 128 bytes). Lastly, since the + * theoretical minimum number of sectors needed by GPT is 6, any + * medium that has less than 6 sectors is never going to be able + * to hold a GPT. The number 6 comes from: + * 1 sector for the PMBR + * 2 sectors for the GPT headers (each 1 sector) + * 2 sectors for the GPT tables (each 1 sector) + * 1 sector for an actual partition + * It's better to catch this pathological case early than behaving + * pathologically later on by panicing... + */ + if (pp->sectorsize < 512 || + pp->sectorsize % sizeof(struct gpt_ent) != 0 || + pp->mediasize < 6 * pp->sectorsize) + goto fail; + + /* * Read both the primary and secondary GPT headers. We have all * the information at our fingertips that way to determine if * there's a GPT, including whether recovery is appropriate. |
