Patch "scsi: vmw_pvscsi: Set correct residual data length" has been added to the 4.4-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    scsi: vmw_pvscsi: Set correct residual data length

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     scsi-vmw_pvscsi-set-correct-residual-data-length.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 2d7aeee08f2042970844b2a153914a8160d29358
Author: Matt Wang <wwentao@xxxxxxxxxx>
Date:   Wed May 19 09:49:32 2021 +0000

    scsi: vmw_pvscsi: Set correct residual data length
    
    [ Upstream commit e662502b3a782d479e67736a5a1c169a703d853a ]
    
    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@xxxxxxxxxx
    Signed-off-by: Matt Wang <wwentao@xxxxxxxxxx>
    Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/scsi/vmw_pvscsi.c b/drivers/scsi/vmw_pvscsi.c
index 3f2a5d6c437b..d25cf084afe7 100644
--- a/drivers/scsi/vmw_pvscsi.c
+++ b/drivers/scsi/vmw_pvscsi.c
@@ -558,7 +558,13 @@ static void pvscsi_complete_request(struct pvscsi_adapter *adapter,
 		case BTSTAT_SUCCESS:
 		case BTSTAT_LINKED_COMMAND_COMPLETED:
 		case BTSTAT_LINKED_COMMAND_COMPLETED_WITH_FLAG:
-			/* If everything went fine, let's move on..  */
+			/*
+			 * Commands like INQUIRY may transfer less data than
+			 * requested by the initiator via bufflen. Set residual
+			 * count to make upper layer aware of the actual amount
+			 * of data returned.
+			 */
+			scsi_set_resid(cmd, scsi_bufflen(cmd) - e->dataLen);
 			cmd->result = (DID_OK << 16);
 			break;