In commit 8930a6c20791 ("scsi: core: add support for request batching") blk-mq last flags was mapped to SCMD_LAST and used as an indicator to send the batch for the drivers that implement it but the error handling code was not updated.

scsi_send_eh_cmnd(...) is used to send error handling commands and request sense. The problem is that request sense comes as a single command that gets into the batch queue and times out. As result device goes offline after several failed resets. This was observed on virtio_scsi device resize operation.

[ 496.316946] sd 0:0:4:0: [sdd] tag#117 scsi_eh_0: requesting sense [ 506.786356] sd 0:0:4:0: [sdd] tag#117 scsi_send_eh_cmnd timeleft: 0 [ 506.787981] sd 0:0:4:0: [sdd] tag#117 abort

To fix this always set SCMD_LAST flag in scsi_send_eh_cmnd and scsi_reset_ioctl(...).

Fixes: 8930a6c20791 ("scsi: core: add support for request batching") Signed-off-by: Alexander Atanasov alexander.atanasov@virtuozzo.com --- drivers/scsi/scsi_error.c | 2 ++ 1 file changed, 2 insertions(+)

v1->v2: fix it globally not only for virtio_scsi, as suggested by Paolo Bonzini, to avoid reintroducing the same bug.

diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c index c67cdcdc3ba8..1223d34c04da 100644 --- a/drivers/scsi/scsi_error.c +++ b/drivers/scsi/scsi_error.c @@ -1152,6 +1152,7 @@ static enum scsi_disposition scsi_send_eh_cmnd(struct scsi_cmnd *scmd,

scsi_log_send(scmd); scmd->submitter = SUBMITTED_BY_SCSI_ERROR_HANDLER; + scmd->flags |= SCMD_LAST;

/* * Lock sdev->state_mutex to avoid that scsi_device_quiesce() can @@ -2459,6 +2460,7 @@ scsi_ioctl_reset(struct scsi_device *dev, int __user *arg) scsi_init_command(dev, scmd);

scmd->submitter = SUBMITTED_BY_SCSI_RESET_IOCTL; + scmd->flags |= SCMD_LAST; memset(&scmd->sdb, 0, sizeof(scmd->sdb));

scmd->cmd_len = 0;