On Mon, 2012-10-08 at 08:45 +0100, James Bottomley wrote: > On Sun, 2012-10-07 at 11:11 -0700, Nicholas A. Bellinger wrote: > > On Sun, 2012-10-07 at 09:16 +0100, James Bottomley wrote: > > > On Sat, 2012-10-06 at 23:11 -0700, Nicholas A. Bellinger wrote: > > > > On Sat, 2012-10-06 at 21:49 -0400, Christoph Hellwig wrote: > > > > > Currenly all non-pscsi bakcneds report their standards version as > > > > > SPC 2 via ->get_device_rev. > > > > > > > > No, the proper on-the-wire bits to signal SPC-3 compliance are already > > > > being returned by virtual backend drivers within standard INQUIRY > > > > payload data. > > > > > > > > Notice the comment: > > > > > > > > root@tifa:/usr/src/target-pending.git# grep SCSI_SPC_2 drivers/target/*.c > > > > drivers/target/target_core_file.c: return SCSI_SPC_2; /* Returns SPC-3 in Initiator Data */ > > > > drivers/target/target_core_iblock.c: return SCSI_SPC_2; /* Returns SPC-3 in Initiator Data */ > > > > drivers/target/target_core_rd.c: return SCSI_SPC_2; /* Returns SPC-3 in Initiator Data */ > > > > > > That's causing confusion, I think! > > > > > > > > In addition to putting it into the > > > > > inquirty data in spc_emulate_inquiry_std we also use it in two > > > > > places to check on the version of the persistent reservation and > > > > > alua support. What is the benefit of supporting the old-style SCSI 2 > > > > > reservations and ALUA support when they can't be used at all with > > > > > the virtual backends, and can only be used in the corner case emulated > > > > > ALUA/PR support for pscsi? > > > > > > > > > > > > > It's the include/scsi/scsi.h SCSI_3 + SCSI_SPC_* version definition > > > > names that are incorrect: > > > > > > > > #define SCSI_UNKNOWN 0 > > > > #define SCSI_1 1 > > > > #define SCSI_1_CCS 2 > > > > #define SCSI_2 3 > > > > #define SCSI_3 4 /* SPC */ > > > > #define SCSI_SPC_2 5 > > > > #define SCSI_SPC_3 6 > > > > > > > > from spc4r30 section 6.4.2 Standard INQUIRY data, Table 142 -- Version: > > > > > > > > 00h The device server does not claim conformance to any standard. > > > > 01h to 02h Obsolete > > > > 03h The device server complies to ANSI INCITS 301-1997 (a withdrawn standard). > > > > 04h The device server complies to ANSI INCITS 351-2001 (SPC-2). > > > > 05h The device server complies to ANSI INCITS 408-2005 (SPC-3). > > > > 06h The device server complies to this standard. > > > > > > > > How about the following patch to fix the long-standing incorrect name > > > > usage of these three scsi.h defines..? > > > > > > Because it's not incorrect. Your confusion is that the SCSI_ constants > > > should match the inquiry data ... they shouldn't. > > > > No, my current confusion is stemming from why it's OK for SCSI_SPC_[2,3] > > constant names+values to not match what is actually defined in SPC-4 > > drafts for what target INQUIRY emulation bits end up going 'over the > > wire'. > > OK, I don't understand what you didn't get about the explanation below. > But the gist is it's not a constant representing inquiry[2]&7; it's an > ordered set of enumerations representing gross capabilities abstracted > into sdev->scsi_level. > Yes, there is no confusion on how scsi-core is working here.. > > > SCSI_3 does exist, by > > > the way, it was defined in the first version of SPC and there are some > > > devices which conform to it. > > > > > > > Regardless, SCSI_SPC_[2,3] -> SCSI_SPC[3,4] constants for target-core + > > scsi-core should still be re-named to avoid the extra confusion this > > introduces for folks reading code. > > I'm not convinced there is confusion; this use of enumerated levelling > goes back to 2.2 and no-one else has had a problem with it. You're the > only one whose had an issue and it does seem to be because you didn't > bother reading the comment above their definitions in the header file > which does explain what's going on. > The point is that it would be nice to have constants representing on-the-wire values in scsi.h that both scsi-core and target-core can use. What about just defining the proper 'on-the-wire' that target-core needs instead..? diff --git a/include/scsi/scsi.h b/include/scsi/scsi.h index 66216c1..13ee02b 100644 --- a/include/scsi/scsi.h +++ b/include/scsi/scsi.h @@ -541,6 +541,13 @@ static inline int scsi_is_wlun(unsigned int lun) #define SCSI_SPC_3 6 /* + * ANSI INCITS Standard INQUIRY resp[2] version bits + */ +#define SCSI_ANSIVER_SPC2 0x04 /* ANSI INCITS 351-2001 (SPC-2) */ +#define SCSI_ANSIVER_SPC3 0x05 /* ANSI INCITS 408-2005 (SPC-3) */ +#define SCSI_ANSIVER_SPC4 0x06 /* SPC-4 standard draft */ + +/* * INQ PERIPHERAL QUALIFIERS */ #define SCSI_INQ_PQ_CON 0x00 -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
