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

Message ID 20240604144501.3862738-1-martin.petersen@oracle.com
State New
Headers show
Series scsi: sd: Use READ(16) when reading block zero on large capacity disks | expand

Commit Message

Martin K. Petersen June 4, 2024, 2:45 p.m. UTC 
Commit 321da3dc1f3c ("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).

Cc: stable@vger.kernel.org
Fixes: 321da3dc1f3c ("scsi: sd: usb_storage: uas: Access media prior to querying device properties")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=218890
Reported-by: Pierre Tomon <pierretom+12@ik.me>
Suggested-by: Alan Stern <stern@rowland.harvard.edu>
Tested-by: Pierre Tomon <pierretom+12@ik.me>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
---
 drivers/scsi/sd.c | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)
diff mbox series

Patch

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 65cdc8b77e35..6759bd5af58a 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -3572,16 +3572,23 @@  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;
+	char *buffer, cmd[16] = { };
 
 	buffer = kmalloc(buf_len, GFP_KERNEL);
 	if (!buffer)
 		return;
 
-	cmd[0] = READ_10;
-	put_unaligned_be32(0, &cmd[2]); /* Logical block address 0 */
-	put_unaligned_be16(1, &cmd[7]);	/* Transfer 1 logical block */
+	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);