scsi: sd: Implement blacklist option for WRITE SAME w/ UNMAP
SBC-4 states:
"A MAXIMUM UNMAP LBA COUNT field set to a non-zero value indicates the
maximum number of LBAs that may be unmapped by an UNMAP command"
"A MAXIMUM WRITE SAME LENGTH field set to a non-zero value indicates
the maximum number of contiguous logical blocks that the device server
allows to be unmapped or written in a single WRITE SAME command."
Despite the spec being clear on the topic, some devices incorrectly
expect WRITE SAME commands with the UNMAP bit set to be limited to the
value reported in MAXIMUM UNMAP LBA COUNT in the Block Limits VPD.
Implement a blacklist option that can be used to accommodate devices
with this behavior.
Cc: <stable@vger.kernel.org>
Reported-by: Bill Kuzeja <William.Kuzeja@stratus.com>
Reported-by: Ewan D. Milne <emilne@redhat.com>
Reviewed-by: Ewan D. Milne <emilne@redhat.com>
Tested-by: Laurence Oberman <loberman@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index e7818af..15590a0 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -956,6 +956,9 @@ static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result,
if (*bflags & BLIST_NO_DIF)
sdev->no_dif = 1;
+ if (*bflags & BLIST_UNMAP_LIMIT_WS)
+ sdev->unmap_limit_for_ws = 1;
+
sdev->eh_timeout = SCSI_DEFAULT_EH_TIMEOUT;
if (*bflags & BLIST_TRY_VPD_PAGES)
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index fb9f8b5..3d26a729 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -715,13 +715,21 @@ static void sd_config_discard(struct scsi_disk *sdkp, unsigned int mode)
break;
case SD_LBP_WS16:
- max_blocks = min_not_zero(sdkp->max_ws_blocks,
- (u32)SD_MAX_WS16_BLOCKS);
+ if (sdkp->device->unmap_limit_for_ws)
+ max_blocks = sdkp->max_unmap_blocks;
+ else
+ max_blocks = sdkp->max_ws_blocks;
+
+ max_blocks = min_not_zero(max_blocks, (u32)SD_MAX_WS16_BLOCKS);
break;
case SD_LBP_WS10:
- max_blocks = min_not_zero(sdkp->max_ws_blocks,
- (u32)SD_MAX_WS10_BLOCKS);
+ if (sdkp->device->unmap_limit_for_ws)
+ max_blocks = sdkp->max_unmap_blocks;
+ else
+ max_blocks = sdkp->max_ws_blocks;
+
+ max_blocks = min_not_zero(max_blocks, (u32)SD_MAX_WS10_BLOCKS);
break;
case SD_LBP_ZERO: