[PATCH v12 14/20] scsi: Have scsi-ml retry scsi_report_lun_scan errors

Mike Christie
2023-11-14T01:40:29Z

This has scsi_report_lun_scan have scsi-ml retry errors instead of driving
them itself.

There is one behavior change where we no longer retry when
scsi_execute_cmd returns < 0, but we should be ok. We don't need to retry
for failures like the queue being removed, and for the case where there
are no tags/reqs the block layer waits/retries for us. For possible memory
allocation failures from blk_rq_map_kern we use GFP_NOIO, so retrying
will probably not help.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
---
drivers/scsi/scsi_scan.c | 57 +++++++++++++++++++++++-----------------
1 file changed, 33 insertions(+), 24 deletions(-)

diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index 8da0990b2dde..dce2d75e394a 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -1416,14 +1416,34 @@ static int scsi_report_lun_scan(struct scsi_target *starget, blist_flags_t bflag
unsigned int length;
u64 lun;
unsigned int num_luns;
- unsigned int retries;
int result;
struct scsi_lun *lunp, *lun_data;
- struct scsi_sense_hdr sshdr;
struct scsi_device *sdev;
struct Scsi_Host *shost = dev_to_shost(&starget->dev);
+ struct scsi_failure failure_defs[] = {
+ {
+ .sense = UNIT_ATTENTION,
+ .asc = SCMD_FAILURE_ASC_ANY,
+ .ascq = SCMD_FAILURE_ASCQ_ANY,
+ .result = SAM_STAT_CHECK_CONDITION,
+ },
+ /* Fail all CCs except the UA above */
+ {
+ .sense = SCMD_FAILURE_SENSE_ANY,
+ .result = SAM_STAT_CHECK_CONDITION,
+ },
+ /* Retry any other errors not listed above */
+ {
+ .result = SCMD_FAILURE_RESULT_ANY,
+ },
+ {}
+ };
+ struct scsi_failures failures = {
+ .total_allowed = 3,
+ .failure_definitions = failure_defs,
+ };
const struct scsi_exec_args exec_args = {
- .sshdr = &sshdr,
+ .failures = &failures,
};
int ret = 0;

@@ -1494,29 +1514,18 @@ static int scsi_report_lun_scan(struct scsi_target *starget, blist_flags_t bflag
* should come through as a check condition, and will not generate
* a retry.
*/
- for (retries = 0; retries < 3; retries++) {
- SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev,
- "scsi scan: Sending REPORT LUNS to (try %d)\n",
- retries));
-
- result = scsi_execute_cmd(sdev, scsi_cmd, REQ_OP_DRV_IN,
- lun_data, length,
- SCSI_REPORT_LUNS_TIMEOUT, 3,
- &exec_args);
+ scsi_reset_failures(&failures);

- SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev,
- "scsi scan: REPORT LUNS"
- " %s (try %d) result 0x%x\n",
- result ? "failed" : "successful",
- retries, result));
- if (result == 0)
- break;
- else if (scsi_sense_valid(&sshdr)) {
- if (sshdr.sense_key != UNIT_ATTENTION)
- break;
- }
- }
+ SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev,
+ "scsi scan: Sending REPORT LUNS\n"));
+
+ result = scsi_execute_cmd(sdev, scsi_cmd, REQ_OP_DRV_IN, lun_data,
+ length, SCSI_REPORT_LUNS_TIMEOUT, 3,
+ &exec_args);

+ SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev,
+ "scsi scan: REPORT LUNS %s result 0x%x\n",
+ result ? "failed" : "successful", result));
if (result) {
/*
* The device probably does not support a REPORT LUN command
--
2.34.1