On 2/29/24 11:58, Damien Le Moal wrote:
On 2024/02/29 10:54, Bart Van Assche wrote:
On 2/29/24 10:31, Damien Le Moal wrote:
Yes, but I find that a little fragile and given that rw-10 causes problems with
ZBC, I prefer to make it very explicit that the 10B command variants should not
be used.
Hi Damien,
From commit c6463c651d7a ("sd_zbc: Force use of READ16/WRITE16"; v4.10):
-------------------------------------------------------------------------
sd_zbc: Force use of READ16/WRITE16
Normally, sd_read_capacity sets sdp->use_16_for_rw to 1 based on the
disk capacity so that READ16/WRITE16 are used for large drives. However,
for a zoned disk with RC_BASIS set to 0, the capacity reported through
READ_CAPACITY may be very small, leading to use_16_for_rw not being
set and READ10/WRITE10 commands being used, even after the actual zoned
disk capacity is corrected in sd_zbc_read_zones. This causes LBA offset
overflow for accesses beyond 2TB.
As the ZBC standard makes it mandatory for ZBC drives to support
the READ16/WRITE16 commands anyway, make sure that use_16_for_rw is set.
-------------------------------------------------------------------------
Would this change be sufficient to fix the problems mentioned above?
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 997de4daa8c4..71f477e502e9 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -1279,7 +1279,7 @@ static blk_status_t
sd_setup_read_write_cmnd(struct scsi_cmnd *cmd)
if (protect && sdkp->protection_type == T10_PI_TYPE2_PROTECTION) {
ret = sd_setup_rw32_cmnd(cmd, write, lba, nr_blocks,
protect | fua, dld);
- } else if (sdp->use_16_for_rw || (nr_blocks > 0xffff)) {
+ } else if (sdp->use_16_for_rw || (nr_blocks > 0xffff) || (lba >> 32)) {
Sure, that works too, but seems useless given that we do have use_16_for_rw set.
Would clearing use_10_for_rw to 0 cause a problem for zoned UFS drives ?
The patch at the start of this email thread should be sufficient. I
shared the above change because I wanted to make sure that I understand
why 16-byte commands need to be selected explicitly for zoned hard
disks. I plan to post a second version of that patch with the
use_10_for_rw = 0 assignment restored.
Thanks,
Bart.
