[PATCH 3/3] scsi: storvsc: Correctly handle multiple flags in srb_status

From: Michael Kelley
Date: Fri Jun 04 2021 - 13:21:28 EST


Hyper-V is observed to sometimes set multiple flags in the
srb_status, such as ABORTED and ERROR. Current code in
storvsc_handle_error() handles only a single flag being set,
and does nothing when multiple flags are set. Fix this by
changing the case statement into a series of "if" statements
testing individual flags. The functionality for handling each
flag is unchanged.

Signed-off-by: Michael Kelley <mikelley@xxxxxxxxxxxxx>
---
drivers/scsi/storvsc_drv.c | 61 +++++++++++++++++++++++++---------------------
1 file changed, 33 insertions(+), 28 deletions(-)

diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
index fff9441..e96d2aa 100644
--- a/drivers/scsi/storvsc_drv.c
+++ b/drivers/scsi/storvsc_drv.c
@@ -1009,17 +1009,40 @@ static void storvsc_handle_error(struct vmscsi_request *vm_srb,
struct storvsc_scan_work *wrk;
void (*process_err_fn)(struct work_struct *work);
struct hv_host_device *host_dev = shost_priv(host);
- bool do_work = false;

- switch (SRB_STATUS(vm_srb->srb_status)) {
- case SRB_STATUS_ERROR:
+ /*
+ * In some situations, Hyper-V sets multiple bits in the
+ * srb_status, such as ABORTED and ERROR. So process them
+ * individually, with the most specific bits first.
+ */
+
+ if (vm_srb->srb_status & SRB_STATUS_INVALID_LUN) {
+ set_host_byte(scmnd, DID_NO_CONNECT);
+ process_err_fn = storvsc_remove_lun;
+ goto do_work;
+ }
+
+ if (vm_srb->srb_status & SRB_STATUS_ABORTED) {
+ if (vm_srb->srb_status & SRB_STATUS_AUTOSENSE_VALID &&
+ /* Capacity data has changed */
+ (asc == 0x2a) && (ascq == 0x9)) {
+ process_err_fn = storvsc_device_scan;
+ /*
+ * Retry the I/O that triggered this.
+ */
+ set_host_byte(scmnd, DID_REQUEUE);
+ goto do_work;
+ }
+ }
+
+ if (vm_srb->srb_status & SRB_STATUS_ERROR) {
/*
* Let upper layer deal with error when
* sense message is present.
*/
-
if (vm_srb->srb_status & SRB_STATUS_AUTOSENSE_VALID)
- break;
+ return;
+
/*
* If there is an error; offline the device since all
* error recovery strategies would have already been
@@ -1032,37 +1055,19 @@ static void storvsc_handle_error(struct vmscsi_request *vm_srb,
set_host_byte(scmnd, DID_PASSTHROUGH);
break;
/*
- * On Some Windows hosts TEST_UNIT_READY command can return
- * SRB_STATUS_ERROR, let the upper level code deal with it
- * based on the sense information.
+ * On some Hyper-V hosts TEST_UNIT_READY command can
+ * return SRB_STATUS_ERROR. Let the upper level code
+ * deal with it based on the sense information.
*/
case TEST_UNIT_READY:
break;
default:
set_host_byte(scmnd, DID_ERROR);
}
- break;
- case SRB_STATUS_INVALID_LUN:
- set_host_byte(scmnd, DID_NO_CONNECT);
- do_work = true;
- process_err_fn = storvsc_remove_lun;
- break;
- case SRB_STATUS_ABORTED:
- if (vm_srb->srb_status & SRB_STATUS_AUTOSENSE_VALID &&
- (asc == 0x2a) && (ascq == 0x9)) {
- do_work = true;
- process_err_fn = storvsc_device_scan;
- /*
- * Retry the I/O that triggered this.
- */
- set_host_byte(scmnd, DID_REQUEUE);
- }
- break;
}
+ return;

- if (!do_work)
- return;
-
+do_work:
/*
* We need to schedule work to process this error; schedule it.
*/
--
1.8.3.1