This is a note to let you know that I've just added the patch titled scsi: sd: Implement blacklist option for WRITE SAME w/ UNMAP to the 4.13-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: scsi-sd-implement-blacklist-option-for-write-same-w-unmap.patch and it can be found in the queue-4.13 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 28a0bc4120d38a394499382ba21d6965a67a3703 Mon Sep 17 00:00:00 2001 From: "Martin K. Petersen" <martin.petersen@xxxxxxxxxx> Date: Wed, 27 Sep 2017 21:35:12 -0400 Subject: scsi: sd: Implement blacklist option for WRITE SAME w/ UNMAP From: Martin K. Petersen <martin.petersen@xxxxxxxxxx> commit 28a0bc4120d38a394499382ba21d6965a67a3703 upstream. 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. Reported-by: Bill Kuzeja <William.Kuzeja@xxxxxxxxxxx> Reported-by: Ewan D. Milne <emilne@xxxxxxxxxx> Reviewed-by: Ewan D. Milne <emilne@xxxxxxxxxx> Tested-by: Laurence Oberman <loberman@xxxxxxxxxx> Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/scsi/scsi_scan.c | 3 +++ drivers/scsi/sd.c | 16 ++++++++++++---- include/scsi/scsi_device.h | 1 + include/scsi/scsi_devinfo.h | 1 + 4 files changed, 17 insertions(+), 4 deletions(-) --- a/drivers/scsi/scsi_scan.c +++ b/drivers/scsi/scsi_scan.c @@ -956,6 +956,9 @@ static int scsi_add_lun(struct scsi_devi 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) --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -715,13 +715,21 @@ static void sd_config_discard(struct scs 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: --- a/include/scsi/scsi_device.h +++ b/include/scsi/scsi_device.h @@ -182,6 +182,7 @@ struct scsi_device { unsigned no_dif:1; /* T10 PI (DIF) should be disabled */ unsigned broken_fua:1; /* Don't set FUA bit */ unsigned lun_in_cdb:1; /* Store LUN bits in CDB[1] */ + unsigned unmap_limit_for_ws:1; /* Use the UNMAP limit for WRITE SAME */ atomic_t disk_events_disable_depth; /* disable depth for disk events */ --- a/include/scsi/scsi_devinfo.h +++ b/include/scsi/scsi_devinfo.h @@ -29,5 +29,6 @@ #define BLIST_TRY_VPD_PAGES 0x10000000 /* Attempt to read VPD pages */ #define BLIST_NO_RSOC 0x20000000 /* don't try to issue RSOC */ #define BLIST_MAX_1024 0x40000000 /* maximum 1024 sector cdb length */ +#define BLIST_UNMAP_LIMIT_WS 0x80000000 /* Use UNMAP limit for WRITE SAME */ #endif Patches currently in stable-queue which might be from martin.petersen@xxxxxxxxxx are queue-4.13/scsi-sd-do-not-override-max_sectors_kb-sysfs-setting.patch queue-4.13/scsi-sd-implement-blacklist-option-for-write-same-w-unmap.patch