Messages in this thread | | | Subject | Re: [PATCH v2] nvme: use uuid_t in nvme_ns | From | Johannes Thumshirn <> | Date | Mon, 12 Jun 2017 12:04:18 +0200 |
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On 06/12/2017 11:50 AM, Andy Shevchenko wrote: >> len = NVME_NIDT_UUID_LEN; >> - memcpy(ns->uuid, data + pos + sizeof(*cur), len); >> + uuid_copy(&ns->uuid, data + pos + sizeof(*cur)); > > So, this reveals two thins: > 1) shall we define NVME_NIDT_UUID_LEN to be UUID_LEN or substitute it > completely with the latter?
No, we have NVME_NIDT_UUID_LEN but also NVME_NIDT_NGUID_LEN and NVME_NIDT_EUI64_LEN.
> 2) Is the len variable used later in the function?
Yes, we have to iterate the buffer by len, which can (currently) be either 8 or 16 bytes. New types which may emerge someday in the future might have a different length.
> >> - if (!memchr_inv(ns->uuid, 0, sizeof(ns->uuid)) || >> + if (uuid_is_null(&ns->uuid) || >> !memchr_inv(ns->nguid, 0, sizeof(ns->nguid))) > >> u8 nguid[16]; >> - u8 uuid[16]; >> + uuid_t uuid; > > Do you plan to switch nguid to be guid_t / uuid_t ? >
I'm not sure the NVMe NGUID is the same as a GUID (a.k.a little endian UUID). Quoting from the spec:
"This field uses the EUI-64 based 16-byte designator format. Bytes 114:112 contain the 24-bit Organizationally Unique Identifier (OUI) value assigned by the IEEE Registration Authority. Bytes 119:115 contain an extension identifer assigned by the corresponding organization. Bytes 111:104 contain the vendor specific extension identifier assigned by the corresponding organization. See the IEEE EUI-64 guidelines for more information."
But maybe Christoph can clarify it.
Byte, Johannes -- Johannes Thumshirn Storage jthumshirn@suse.de +49 911 74053 689 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: Felix Imendörffer, Jane Smithard, Graham Norton HRB 21284 (AG Nürnberg) Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850
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