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>
This commit is contained in:
Martin K. Petersen
2017-09-27 21:35:12 -04:00
父節點 d0b7a9095c
當前提交 28a0bc4120
共有 4 個文件被更改,包括 17 次插入4 次删除

查看文件

@@ -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)

查看文件

@@ -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: