The Fibre Channel transport topology created by storvsc exposes only one dummy remote port per SCSI host. Its scsi_target_id is always zero.
As a result, the FC transport user-scan path looks up the remote port using target ID 0. It cannot initiate a scan for Target 1 or higher. No SCSI command is therefore sent to Hyper-V when userspace explicitly requests a scan of one of these targets. storvsc itself supports up to STORVSC_FC_MAX_TARGETS and already passes scmnd->device->id to Hyper-V as vm_srb->target_id. Devices on Target 1 and higher work when initially discovered. They can also be rediscovered by a full host scan, such as the scan triggered after an FC port bounce. Provide a storvsc-specific user_scan callback that uses the exported scsi_scan_target() interface. Iterate over the requested channel and target ranges so that wildcard and explicitly addressed scans retain the expected SCSI sysfs scan semantics. This bypasses the single-rport lookup in fc_user_scan() and allows userspace to explicitly scan any target supported by storvsc without requiring one synthetic fc_rport for every Hyper-V target. Signed-off-by: Laurence Oberman <[email protected]> --- Changes in v2: - Replace the private, unexported scsi_scan_host_selected() helper with the exported scsi_scan_target() interface. - Preserve wildcard channel and target scan behavior. - Verify that storvsc_eh_timed_out() does not use the FC error-handler helpers; the reported missing-rport dereference is not present. drivers/scsi/storvsc_drv.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c index 571ea549152b..58b6ae96d03f 100644 --- a/drivers/scsi/storvsc_drv.c +++ b/drivers/scsi/storvsc_drv.c @@ -520,6 +520,36 @@ static void storvsc_host_scan(struct work_struct *work) scsi_scan_host(host); } +#if IS_ENABLED(CONFIG_SCSI_FC_ATTRS) +static int storvsc_user_scan(struct Scsi_Host *host, + unsigned int channel, + unsigned int id, + u64 lun) +{ + unsigned int first_channel, last_channel; + unsigned int first_id, end_id; + unsigned int ch, target; + + if ((channel != SCAN_WILD_CARD && channel > host->max_channel) || + (id != SCAN_WILD_CARD && id >= host->max_id) || + (lun != SCAN_WILD_CARD && lun >= host->max_lun)) + return -EINVAL; + + first_channel = channel == SCAN_WILD_CARD ? 0 : channel; + last_channel = channel == SCAN_WILD_CARD ? host->max_channel : channel; + first_id = id == SCAN_WILD_CARD ? 0 : id; + end_id = id == SCAN_WILD_CARD ? host->max_id : id + 1; + + for (ch = first_channel; ch <= last_channel; ch++) { + for (target = first_id; target < end_id; target++) + scsi_scan_target(&host->shost_gendev, ch, target, lun, + SCSI_SCAN_MANUAL); + } + + return 0; +} +#endif + static void storvsc_remove_lun(struct work_struct *work) { struct storvsc_scan_work *wrk; @@ -2232,6 +2262,8 @@ static int __init storvsc_drv_init(void) fc_transport_template = fc_attach_transport(&fc_transport_functions); if (!fc_transport_template) return -ENODEV; + + fc_transport_template->user_scan = storvsc_user_scan; #endif ret = vmbus_driver_register(&storvsc_drv); -- 2.55.0
