When the SCSI device is initialized, check whether it supports WRITE_SAME_16 or WRITE_SAME_10 in the sd_read_write_same(). If the back-end storage device does not support queries, it will not set sdkp->ws16 as 1. When the WRITE_SAME io is issued through the blkdev_issue_write_same(), the WRITE_SAME type is set to WRITE_SAME_10 by default in the sd_setup_write_same_cmnd() since of "sdkp->ws16=0". If the storage device does not support WRITE_SAME_10, then the SCSI device is set to not support WRITE_SAME. Currently, some storage devices do not provide queries for WRITE_SAME_16/WRITE_SAME_10 support, but they do support WRITE_SAME_16 and do not support WRITE_SAME_10. So in order for these devices to use WRITE_SAME, we need a new module parameter to set whether SCSI disks support WRITE_SAME_16 by default. Signed-off-by: AlexChen <alex.chen@xxxxxxxxxx> --- drivers/scsi/sd.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 4f7e7b607..ff368701d 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -104,6 +104,9 @@ MODULE_ALIAS_SCSI_DEVICE(TYPE_ZBC); #define SD_MINORS 0 #endif +static int sd_default_support_ws16; +module_param(sd_default_support_ws16, int, 0644); + static void sd_config_discard(struct scsi_disk *, unsigned int); static void sd_config_write_same(struct scsi_disk *); static int sd_revalidate_disk(struct gendisk *); @@ -3014,7 +3017,8 @@ static void sd_read_write_same(struct scsi_disk *sdkp, unsigned char *buffer) sdev->no_write_same = 1; } - if (scsi_report_opcode(sdev, buffer, SD_BUF_SIZE, WRITE_SAME_16) == 1) + if (scsi_report_opcode(sdev, buffer, SD_BUF_SIZE, WRITE_SAME_16) == 1 || + sd_default_support_ws16) sdkp->ws16 = 1; if (scsi_report_opcode(sdev, buffer, SD_BUF_SIZE, WRITE_SAME) == 1) -- 2.19.1
