Messages in this thread | | | Date | Fri, 24 Jun 2016 01:09:20 -0700 | From | Christoph Hellwig <> | Subject | Re: [PATCH 3/3] nvme: Check if drive is locked using ATA Security |
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On Sun, Jun 19, 2016 at 04:06:34PM -0700, Jethro Beekman wrote: > Signed-off-by: Jethro Beekman <kernel@jbeekman.nl> > --- > drivers/nvme/host/core.c | 49 +++++++++++++++++++++++++++++++++++++++++- > 1 file changed, 48 insertions(+), 1 deletion(-) > > diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c > index da027ed..0164122 100644 > --- a/drivers/nvme/host/core.c > +++ b/drivers/nvme/host/core.c > @@ -1389,10 +1389,57 @@ int nvme_security_recv(struct nvme_ctrl *dev, u8 protocol, void *buf, > return nvme_submit_sync_cmd(dev->admin_q, &c, buf, len); > } > > +#define OACS_SECURITY (1<<0) > +#define SCSI_SECURITY_PROTOCOL_ATA_SECURITY 0xef > +#define ATA_SECURITY_LOCKED 0x4
It would be great to have this out in a header or maybe rather headers. OACS_SECURITY should go into nvme.h, we probably should have a new header for the SCSI security protocols (e.g. include/scsi/scsi_security.h ?), and I'm not sure what to do with ATA_SECURITY_LOCKED - maybe just add it to scsi_security.h for now until we get a more fully blown ata security implementation that even includes ATA :))
> static bool nvme_security_is_locked(struct nvme_ctrl *ctrl, > struct nvme_id_ctrl *id) > { > - return false; > + int err; > + unsigned int i; > + bool found; > + u8 protocols[256+8]; /* 8 byte hdr + max number of possible protocols */
Please define a constant for the length in the new scsi_security.h header.
> + /* find ata security protocol */ > + n = be16_to_cpup((__be16 *)(protocols+6));
Just use get_unaligned_be16 that operates directly on the char array, similar to how we do in lots of places in the SCSI stack.
> + for (i = 0; i <= n; i++) { > + if (protocols[8+i] == SCSI_SECURITY_PROTOCOL_ATA_SECURITY) { > + found = true; > + break; > + } > + }
I wonder if it might be a good idea to change the structure here a bit to allow for future other protocols and have each protocol in a helper, e.g. do something like
for (i = 0; i <= n; i++) { switch (protocols[8 + i]) { case SCSI_SECURITY_PROTOCOL_ATA_SECURITY: locked |= nvme_security_ata_is_locked() break; default: break; }
> + return ata_security[1] == 0xe && (ata_security[9]&ATA_SECURITY_LOCKED);
Can we have a sumbolic name for the 0xe? Also please always add spaces around your operators.
But after all this nitpicking the general idea looks fine, thanks a lot for the patch!
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