Commit 7926d51f authored by Martin K. Petersen's avatar Martin K. Petersen

scsi: sd: Use READ(16) when reading block zero on large capacity disks

Commit 321da3dc ("scsi: sd: usb_storage: uas: Access media prior
to querying device properties") triggered a read to LBA 0 before
attempting to inquire about device characteristics. This was done
because some protocol bridge devices will return generic values until
an attached storage device's media has been accessed.

Pierre Tomon reported that this change caused problems on a large
capacity external drive connected via a bridge device. The bridge in
question does not appear to implement the READ(10) command.

Issue a READ(16) instead of READ(10) when a device has been identified
as preferring 16-byte commands (use_16_for_rw heuristic).

Link: https://bugzilla.kernel.org/show_bug.cgi?id=218890
Link: https://lore.kernel.org/r/70dd7ae0-b6b1-48e1-bb59-53b7c7f18274@rowland.harvard.edu
Link: https://lore.kernel.org/r/20240605022521.3960956-1-martin.petersen@oracle.com
Fixes: 321da3dc ("scsi: sd: usb_storage: uas: Access media prior to querying device properties")
Cc: stable@vger.kernel.org
Reported-by: default avatarPierre Tomon <pierretom+12@ik.me>
Suggested-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Tested-by: default avatarPierre Tomon <pierretom+12@ik.me>
Reviewed-by: default avatarBart Van Assche <bvanassche@acm.org>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent d53b681c
......@@ -3565,16 +3565,23 @@ static bool sd_validate_opt_xfer_size(struct scsi_disk *sdkp,
static void sd_read_block_zero(struct scsi_disk *sdkp)
{
unsigned int buf_len = sdkp->device->sector_size;
char *buffer, cmd[10] = { };
struct scsi_device *sdev = sdkp->device;
unsigned int buf_len = sdev->sector_size;
u8 *buffer, cmd[16] = { };
buffer = kmalloc(buf_len, GFP_KERNEL);
if (!buffer)
return;
if (sdev->use_16_for_rw) {
cmd[0] = READ_16;
put_unaligned_be64(0, &cmd[2]); /* Logical block address 0 */
put_unaligned_be32(1, &cmd[10]);/* Transfer 1 logical block */
} else {
cmd[0] = READ_10;
put_unaligned_be32(0, &cmd[2]); /* Logical block address 0 */
put_unaligned_be16(1, &cmd[7]); /* Transfer 1 logical block */
}
scsi_execute_cmd(sdkp->device, cmd, REQ_OP_DRV_IN, buffer, buf_len,
SD_TIMEOUT, sdkp->max_retries, NULL);
......
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