RE: [PATCH 3/3] scsi: storvsc: Correctly handle multiple flags in srb_status
From: Long Li <longli@microsoft.com>
Date: 2021-06-07 22:25:19
Also in:
linux-scsi, lkml
quoted hunk ↗ jump to hunk
Subject: [PATCH 3/3] scsi: storvsc: Correctly handle multiple flags in srb_status 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 <redacted> --- 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 indexfff9441..e96d2aa 100644--- a/drivers/scsi/storvsc_drv.c +++ b/drivers/scsi/storvsc_drv.c@@ -1009,17 +1009,40 @@ static void storvsc_handle_error(structvmscsi_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) {
I'm curious on SRB_STATUS_INVALID_LUN and SRB_STATUS_ABORTED, the actions on those two codes are different. It doesn't look like we can get those two in the same status code.
/*
* 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