[PATCH v2] drivers/nvme/host: Fix namespace duplication check rule

[Sungup Moon]

Some NVMe device, use EUI64 and NGUID, has fixed value EUI64 on a
sub-system because of the bit size of ID. Current kernel check the
all IDs should have unique value in a sub-system and globally.
However, if an namespace has duplicate IDs (not all) in a sub-system,
current kernel raise "duplicate IDs in subsystem for nsid" error. But
NVMe Specification defines the namespace unique identifier like this:

When creating a namespace, the controller shall indicate a globally
unique value in one or more of the following:
a) the EUI64 field;
b) the NGUID field; or
c) a Namespace Identification Descriptor with the Namespace Identifier
Type field set to 3h
(reference: 7.11 Unique Identifier; NVM Express 1.4c spec)

So, I suggest the modified nvme_subsys_check_duplicate_ids function
checking uniqueness from all IDS to one more IDs.

I missed the initializing of "duplicated" variable, so I reissue the
version2 patch.

Signed-off-by: Sungup Moon <sungup.moon at samsung.com>
---
 drivers/nvme/host/core.c | 25 ++++++++++++++++++-------
 1 file changed, 18 insertions(+), 7 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index af367b22871b..8c2faa2881a4 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -3902,24 +3902,35 @@ static struct nvme_ns_head *nvme_find_ns_head(struct nvme_ctrl *ctrl,
        return NULL;
 }

+#define IDS_EQUAL(A, B) (memcmp(&(A), &(B), sizeof(A)) == 0)
+
 static int nvme_subsys_check_duplicate_ids(struct nvme_subsystem *subsys,
                struct nvme_ns_ids *ids)
 {
        bool has_uuid = !uuid_is_null(&ids->uuid);
        bool has_nguid = memchr_inv(ids->nguid, 0, sizeof(ids->nguid));
        bool has_eui64 = memchr_inv(ids->eui64, 0, sizeof(ids->eui64));
+       bool duplicated;
        struct nvme_ns_head *h;

        lockdep_assert_held(&subsys->lock);

        list_for_each_entry(h, &subsys->nsheads, entry) {
-               if (has_uuid && uuid_equal(&ids->uuid, &h->ids.uuid))
-                       return -EINVAL;
-               if (has_nguid &&
-                   memcmp(&ids->nguid, &h->ids.nguid, sizeof(ids->nguid)) == 0)
-                       return -EINVAL;
-               if (has_eui64 &&
-                   memcmp(&ids->eui64, &h->ids.eui64, sizeof(ids->eui64)) == 0)
+               duplicated = has_uuid || has_nguid || has_eui64;
+
+               if (has_uuid)
+                       duplicated = duplicated &&
+                               uuid_equal(&ids->uuid, &h->ids.uuid);
+
+               if (has_nguid)
+                       duplicated = duplicated &&
+                               IDS_EQUAL(ids->nguid, h->ids.nguid);
+
+               if (has_eui64)
+                       duplicated = duplicated &&
+                               IDS_EQUAL(ids->eui64, h->ids.eui64);
+
+               if (duplicated)
                        return -EINVAL;
        }

--
2.34.1