From 28a0bc4120d38a394499382ba21d6965a67a3703 Mon Sep 17 00:00:00 2001 From: "Martin K. Petersen" Date: Wed, 27 Sep 2017 21:35:12 -0400 Subject: 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: Reported-by: Bill Kuzeja Reported-by: Ewan D. Milne Reviewed-by: Ewan D. Milne Tested-by: Laurence Oberman Signed-off-by: Martin K. Petersen --- drivers/scsi/sd.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) (limited to 'drivers/scsi/sd.c') diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index fb9f8b5f4673..3d26a729825c 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: -- cgit v1.2.3 From 77082ca503bed061f7fbda7cfd7c93beda967a41 Mon Sep 17 00:00:00 2001 From: "Martin K. Petersen" Date: Wed, 27 Sep 2017 21:38:59 -0400 Subject: scsi: sd: Do not override max_sectors_kb sysfs setting A user may lower the max_sectors_kb setting in sysfs to accommodate certain workloads. Previously we would always set the max I/O size to either the block layer default or the optional preferred I/O size reported by the device. Keep the current heuristics for the initial setting of max_sectors_kb. For subsequent invocations, only update the current queue limit if it exceeds the capabilities of the hardware. Cc: Reported-by: Don Brace Reviewed-by: Martin Wilck Tested-by: Don Brace Signed-off-by: Martin K. Petersen --- drivers/scsi/sd.c | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-) (limited to 'drivers/scsi/sd.c') diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 3d26a729825c..d175c5c5ccf8 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -3107,8 +3107,6 @@ static int sd_revalidate_disk(struct gendisk *disk) sd_read_security(sdkp, buffer); } - sdkp->first_scan = 0; - /* * We now have all cache related info, determine how we deal * with flush requests. @@ -3123,7 +3121,7 @@ static int sd_revalidate_disk(struct gendisk *disk) q->limits.max_dev_sectors = logical_to_sectors(sdp, dev_max); /* - * Use the device's preferred I/O size for reads and writes + * Determine the device's preferred I/O size for reads and writes * unless the reported value is unreasonably small, large, or * garbage. */ @@ -3137,8 +3135,19 @@ static int sd_revalidate_disk(struct gendisk *disk) rw_max = min_not_zero(logical_to_sectors(sdp, dev_max), (sector_t)BLK_DEF_MAX_SECTORS); - /* Combine with controller limits */ - q->limits.max_sectors = min(rw_max, queue_max_hw_sectors(q)); + /* Do not exceed controller limit */ + rw_max = min(rw_max, queue_max_hw_sectors(q)); + + /* + * Only update max_sectors if previously unset or if the current value + * exceeds the capabilities of the hardware. + */ + if (sdkp->first_scan || + q->limits.max_sectors > q->limits.max_dev_sectors || + q->limits.max_sectors > q->limits.max_hw_sectors) + q->limits.max_sectors = rw_max; + + sdkp->first_scan = 0; set_capacity(disk, logical_to_sectors(sdp, sdkp->capacity)); sd_config_write_same(sdkp); -- cgit v1.2.3