re: uas: Use GFP_NOIO rather then GFP_ATOMIC where possible

Dan Carpenter
2014-03-28T08:08:33Z

Hello Hans de Goede,

The patch e36e64930cff: "uas: Use GFP_NOIO rather then GFP_ATOMIC
where possible" from Nov 7, 2013, leads to the following static
checker warning:

drivers/usb/storage/uas.c:806 uas_eh_task_mgmt()
error: scheduling with locks held: 'spin_lock:lock'

drivers/usb/storage/uas.c
789 spin_lock_irqsave(&devinfo->lock, flags);
790
791 if (devinfo->resetting) {
792 spin_unlock_irqrestore(&devinfo->lock, flags);
793 return FAILED;
794 }
795
796 if (devinfo->running_task) {
797 shost_printk(KERN_INFO, shost,
798 "%s: %s: error already running a task\n",
799 __func__, fname);
800 spin_unlock_irqrestore(&devinfo->lock, flags);
801 return FAILED;
802 }
803
804 devinfo->running_task = 1;
805 memset(&devinfo->response, 0, sizeof(devinfo->response));
806 sense_urb = uas_submit_sense_urb(cmnd, GFP_NOIO,
^^^^^^^^
The original code had this as GFP_ATOMIC because we can't sleep while
we have spin_lock_irqsave() held.

807 devinfo->use_streams ? tag : 0);
808 if (!sense_urb) {
809 shost_printk(KERN_INFO, shost,
810 "%s: %s: submit sense urb failed\n",
811 __func__, fname);
812 devinfo->running_task = 0;
813 spin_unlock_irqrestore(&devinfo->lock, flags);
814 return FAILED;
815 }
816 if (uas_submit_task_urb(cmnd, GFP_NOIO, function, tag)) {
^^^^^^^^
Same.

817 shost_printk(KERN_INFO, shost,
818 "%s: %s: submit task mgmt urb failed\n",
819 __func__, fname);
820 devinfo->running_task = 0;
821 spin_unlock_irqrestore(&devinfo->lock, flags);
822 usb_kill_urb(sense_urb);
823 return FAILED;
824 }
825 spin_unlock_irqrestore(&devinfo->lock, flags);

regards,
dan carpenter