From e662502b3a782d479e67736a5a1c169a703d853a Mon Sep 17 00:00:00 2001 From: Matt Wang Date: Wed, 19 May 2021 09:49:32 +0000 Subject: [PATCH] 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 Signed-off-by: Martin K. Petersen --- drivers/scsi/vmw_pvscsi.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/vmw_pvscsi.c b/drivers/scsi/vmw_pvscsi.c index 8a79605..b9969fc 100644 --- a/drivers/scsi/vmw_pvscsi.c +++ b/drivers/scsi/vmw_pvscsi.c @@ -585,7 +585,13 @@ 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; -- 2.7.4