Hi,
This follows on from something I mentioned in my recent post "[PATCH]
storage: Don't scan target 7 for SCM USB-SCSI converters".
In drivers/usb/storage/usb.c, usb_stor_control_thread():
/* reject if target != 0 or if LUN is higher than
* the maximum known LUN
*/
else if (us->srb->device->id &&
!(us->fflags & US_FL_SCM_MULT_TARG)) {
usb_stor_dbg(us, "Bad target number (%d:%llu)\n",
us->srb->device->id,
us->srb->device->lun);
us->srb->result = DID_BAD_TARGET << 16;
}
else if (us->srb->device->lun > us->max_lun) {
usb_stor_dbg(us, "Bad LUN (%d:%llu)\n",
...
The condition (us->srb->device->id && !(us->fflags & US_FL_SCM_MULT_TARG))
means:
- If not SCM_MULT_TARG, reject if us->srb->device->id is non-zero. That
works for the usual case.
- If SCM_MULT_TARG, never reject. Hmm...
Would it be better/clearer to change the condition to simply
(us->srb->device->id >= host->max_id)
Then the command is rejected if us->srb->device->id is too large, and works
for the SCM_MULT_TARG case too. (host->max_id is 1 for the non-SCM_MULT_TARG
case.) Plus the condition matches nicely with the later LUN check. Untested
patch below.
Signed-off-by: Mark Knibbs <[email protected]>
diff -up linux-3.17-rc6/drivers/usb/storage/usb.c.orig
linux-3.17-rc6/drivers/usb/storage/usb.c
--- linux-3.17-rc6/drivers/usb/storage/usb.c.orig 2014-09-21
23:43:02.000000000 +0100
+++ linux-3.17-rc6/drivers/usb/storage/usb.c 2014-09-24 13:09:55.000000000
+0100
@@ -342,11 +342,10 @@ static int usb_stor_control_thread(void
us->srb->result = DID_ERROR << 16;
}
- /* reject if target != 0 or if LUN is higher than
+ /* reject if target is invalid or if LUN is higher than
* the maximum known LUN
*/
- else if (us->srb->device->id &&
- !(us->fflags & US_FL_SCM_MULT_TARG)) {
+ else if (us->srb->device->id >= host->max_id) {
usb_stor_dbg(us, "Bad target number (%d:%llu)\n",
us->srb->device->id,
us->srb->device->lun);
--
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