This patch started life as as534, and has been re-diffed against the latest
tree.

usb-storage has a small loophole, a window between the time queuecommand
accepts a new command and the time the control thread starts to execute
it.  If disconnect is called during that window, the driver won't cancel
the pending command -- we've been relying on the SCSI core to cancel it
for us during host removal.  But it's better for usb-storage to cancel it;  
this avoids races and reduces reliance on the SCSI core.  Fortunately
cancelling these commands is easy to do; the key is to do it _before_ 
calling scsi_remove_host.

Greg, please apply.

Matt

Signed-off-by: Alan Stern <[EMAIL PROTECTED]>
Signed-off-by: Matthew Dharm <[EMAIL PROTECTED]>

Index: usb-2.6/drivers/usb/storage/usb.c
===================================================================
--- usb-2.6.orig/drivers/usb/storage/usb.c
+++ usb-2.6/drivers/usb/storage/usb.c
@@ -833,6 +833,19 @@ static void quiesce_and_remove_host(struct us_data 
        /* Wait for the current command to finish, then remove the host */
        down(&us->dev_semaphore);
        up(&us->dev_semaphore);
+
+       /* queuecommand won't accept any new commands and the control
+        * thread won't execute a previously-queued command.  If there
+        * is such a command pending, complete it with an error. */
+       if (us->srb) {
+               us->srb->result = DID_NO_CONNECT << 16;
+               scsi_lock(us_to_host(us));
+               us->srb->scsi_done(us->srb);
+               us->srb = NULL;
+               scsi_unlock(us_to_host(us));
+       }
+
+       /* Now we own no commands so it's safe to remove the SCSI host */
        scsi_remove_host(us_to_host(us));
 }
 
-- 
Matthew Dharm                              Home: [EMAIL PROTECTED] 
Maintainer, Linux USB Mass Storage Driver

Sir, for the hundreth time, we do NOT carry 600-round boxes of belt-fed 
suction darts!
                                        -- Salesperson to Greg
User Friendly, 12/30/1997

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