[SCSI] sd: Logical Block Provisioning update

SBC3r26 contains many changes to the Logical Block Provisioning
interfaces (formerly known as Thin Provisioning ditto). This patch
implements support for both the old and new schemes using the same
heuristic as before (whether the LBP VPD page is present).

The new code also allows the provisioning mode (i.e. choice of command)
to be overridden on a per-device basis via sysfs. Two additional modes
are supported in this version:

 - WRITE SAME(10) with the UNMAP bit set

 - WRITE SAME(10) without the UNMAP bit set. This allows us to support
   devices that predate the TP/LBP enhancements in SBC3 and which work
   by way zero-detection

Switching between modes has been consolidated in a helper function that
also updates the block layer topology according to the limitations of
the chosen command.

I experimented with trying WRITE SAME(16) if UNMAP fails, WRITE SAME(10)
if WRITE SAME(16) fails, etc. but found several devices that got
cranky. So for now we'll disable discard if one of the commands
fail. The user still has the option of selecting a different mode in
sysfs.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

1 files changed, 7 insertions, 0 deletions

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index e531acf..3829bf0 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -867,6 +867,13 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
 				description = "Host Data Integrity Failure";
 				action = ACTION_FAIL;
 				error = -EILSEQ;
+			/* INVALID COMMAND OPCODE or INVALID FIELD IN CDB */
+			} else if ((sshdr.asc == 0x20 || sshdr.asc == 0x24) &&
+				   (cmd->cmnd[0] == UNMAP ||
+				    cmd->cmnd[0] == WRITE_SAME_16 ||
+				    cmd->cmnd[0] == WRITE_SAME)) {
+				description = "Discard failure";
+				action = ACTION_FAIL;
 			} else
 				action = ACTION_FAIL;
 			break;