tree 45f0a900f458dda1ef95cf386dcd213290eb13cb
parent 122c81c563b0c1c6b15ff76a9159af5ee1f21563
author Matt Wang <wwentao@vmware.com> 1621417772 +0000
committer Martin K. Petersen <martin.petersen@oracle.com> 1621651298 -0400

scsi: vmw_pvscsi: Set correct residual data length

Some commands (such as INQUIRY) may return less data than the initiator
requested. To avoid conducting useless information, set the right residual
count to make upper layer aware of this.

Before (INQUIRY PAGE 0xB0 with 128B buffer):

$ sg_raw -r 128 /dev/sda 12 01 B0 00 80 00
SCSI Status: Good

Received 128 bytes of data:
 00 00 b0 00 3c 01 00 00 00 00 00 00 00 00 00 00 00 ...<............
 10 00 00 00 00 00 01 00 00 00 00 00 40 00 00 08 00 ...........@....
 20 80 00 00 00 00 00 00 00 00 00 20 00 00 00 00 00 .......... .....
 30 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
 40 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
 50 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
 60 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
 70 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................

After:

$ sg_raw -r 128 /dev/sda 12 01 B0 00 80 00
SCSI Status: Good

Received 64 bytes of data:
00 00 b0 00 3c 01 00 00 00 00 00 00 00 00 00 00 00 ...<............
10 00 00 00 00 00 01 00 00 00 00 00 40 00 00 08 00 ...........@....
20 80 00 00 00 00 00 00 00 00 00 20 00 00 00 00 00 .......... .....
30 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................

[mkp: clarified description]

Link: https://lore.kernel.org/r/03C41093-B62E-43A2-913E-CFC92F1C70C3@vmware.com
Signed-off-by: Matt Wang <wwentao@vmware.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>