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Rework the logic of sequential SCSI LUN scanner.

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Previous logic was not differentiating disconnected LUNs and absent targets.
That made it to stop scan if LUN 0 was not found for any reason.  That made
problematic, for example, using iSCSI targets declaring SPC-2 compliance and
having no LUN 0 configured.

The new logic continues sequential LUN scan if:
 -- we have more configured LUNs that need recheck;
 -- this LUN is connected and its SCSI version allows more LUNs;
 -- this LUN is disconnected, its SCSI version allows more LUNs and we
    guess they may be connected (we haven't scanned first 8 LUNs yet or
    kern.cam.cam_srch_hi sysctl is set to scan more).

Reported by:	trasz
MFC after:	1 month
This commit is contained in:
Alexander Motin 2014-10-02 09:42:11 +00:00
parent dc7717a863
commit 1d4bc8bce6
1 changed files with 36 additions and 62 deletions
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98
sys/cam/scsi/scsi_xpt.c
View File

@ -1135,6 +1135,7 @@ probedone(struct cam_periph *periph, union ccb *done_ccb)
u_int8_t periph_qual;
path->device->flags |= CAM_DEV_INQUIRY_DATA_VALID;
scsi_find_quirk(path->device);
inq_buf = &path->device->inq_data;
periph_qual = SID_QUAL(inq_buf);
@ -1163,8 +1164,6 @@ probedone(struct cam_periph *periph, union ccb *done_ccb)
goto out;
}
scsi_find_quirk(path->device);
scsi_devise_transport(path);
if (path->device->lun_id == 0 &&
@ -1213,10 +1212,13 @@ probedone(struct cam_periph *periph, union ccb *done_ccb)
: SF_RETRY_UA,
&softc->saved_ccb) == ERESTART) {
goto outr;
} else if ((done_ccb->ccb_h.status & CAM_DEV_QFRZN) != 0) {
/* Don't wedge the queue */
xpt_release_devq(done_ccb->ccb_h.path, /*count*/1,
/*run_queue*/TRUE);
} else {
if ((done_ccb->ccb_h.status & CAM_DEV_QFRZN) != 0) {
/* Don't wedge the queue */
xpt_release_devq(done_ccb->ccb_h.path,
/*count*/1, /*run_queue*/TRUE);
}
path->device->flags &= ~CAM_DEV_INQUIRY_DATA_VALID;
}
/*
* If we get to this point, we got an error status back
@ -1975,7 +1977,7 @@ scsi_scan_bus(struct cam_periph *periph, union ccb *request_ccb)
struct cam_path *path, *oldpath;
scsi_scan_bus_info *scan_info;
struct cam_et *target;
struct cam_ed *device;
struct cam_ed *device, *nextdev;
int next_target;
path_id_t path_id;
target_id_t target_id;
@ -1984,18 +1986,10 @@ scsi_scan_bus(struct cam_periph *periph, union ccb *request_ccb)
oldpath = request_ccb->ccb_h.path;
status = cam_ccb_status(request_ccb);
/* Reuse the same CCB to query if a device was really found */
scan_info = (scsi_scan_bus_info *)request_ccb->ccb_h.ppriv_ptr0;
xpt_setup_ccb(&request_ccb->ccb_h, request_ccb->ccb_h.path,
request_ccb->ccb_h.pinfo.priority);
request_ccb->ccb_h.func_code = XPT_GDEV_TYPE;
path_id = request_ccb->ccb_h.path_id;
target_id = request_ccb->ccb_h.target_id;
lun_id = request_ccb->ccb_h.target_lun;
xpt_action(request_ccb);
target = request_ccb->ccb_h.path->target;
next_target = 1;
@ -2068,56 +2062,36 @@ scsi_scan_bus(struct cam_periph *periph, union ccb *request_ccb)
}
}
} else {
mtx_unlock(&target->luns_mtx);
if (request_ccb->ccb_h.status != CAM_REQ_CMP) {
int phl;
/*
* If we already probed lun 0 successfully, or
* we have additional configured luns on this
* target that might have "gone away", go onto
* the next lun.
*/
/*
* We may touch devices that we don't
* hold references too, so ensure they
* don't disappear out from under us.
* The target above is referenced by the
* path in the request ccb.
*/
phl = 0;
device = TAILQ_FIRST(&target->ed_entries);
if (device != NULL) {
phl = CAN_SRCH_HI_SPARSE(device);
if (device->lun_id == 0)
device = TAILQ_NEXT(device, links);
}
if ((lun_id != 0) || (device != NULL)) {
if (lun_id < (CAM_SCSI2_MAXLUN-1) || phl) {
lun_id++;
next_target = 0;
}
}
if (lun_id == request_ccb->ccb_h.target_lun
|| lun_id > scan_info->cpi->max_lun)
next_target = 1;
} else {
mtx_unlock(&target->luns_mtx);
device = request_ccb->ccb_h.path->device;
if ((SCSI_QUIRK(device)->quirks &
CAM_QUIRK_NOLUNS) == 0) {
/* Try the next lun */
if (lun_id < (CAM_SCSI2_MAXLUN-1)
|| CAN_SRCH_HI_DENSE(device)) {
lun_id++;
/* Continue sequential LUN scan if: */
/* -- we have more LUNs that need recheck */
mtx_lock(&target->bus->eb_mtx);
nextdev = device;
while ((nextdev = TAILQ_NEXT(nextdev, links)) != NULL)
if ((nextdev->flags & CAM_DEV_UNCONFIGURED) == 0)
break;
mtx_unlock(&target->bus->eb_mtx);
if (nextdev != NULL) {
next_target = 0;
/* -- this LUN is connected and its SCSI version
* allows more LUNs. */
} else if ((device->flags & CAM_DEV_UNCONFIGURED) == 0) {
if (lun_id < (CAM_SCSI2_MAXLUN-1) ||
CAN_SRCH_HI_DENSE(device))
next_target = 0;
/* -- this LUN is disconnected, its SCSI version
* allows more LUNs and we guess they may be. */
} else if ((device->flags & CAM_DEV_INQUIRY_DATA_VALID) != 0) {
if (lun_id < (CAM_SCSI2_MAXLUN-1) ||
CAN_SRCH_HI_SPARSE(device))
next_target = 0;
}
}
if (lun_id == request_ccb->ccb_h.target_lun
|| lun_id > scan_info->cpi->max_lun)
next_target = 1;
}
if (next_target == 0) {
lun_id++;
if (lun_id > scan_info->cpi->max_lun)
next_target = 1;
}
}
/*