On 2020/1/20 3:36, Bart Van Assche wrote: > On 2020-01-19 06:13, AlexChen wrote: >> 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) > > Should this be fixed using the quirk mechanism instead of introducing a > new kernel module parameter? Kernel module parameters apply to all SCSI > disk devices irrespective of their vendor and model. The quirk mechanism > can be used to introduce special behavior for certain disk models and > types. See also the output of the following grep command: > > $ git grep -nH '& BLIST' > > Bart. > Thanks for your reply. I will try to fix the problem by the way you suggested above. Thanks Alex > > . >
