usb_blk_nfree      92 dev/usb/usb_mem.c int usb_blk_nfree = 0;
usb_blk_nfree     120 dev/usb/usb_mem.c 			usb_blk_nfree--;
usb_blk_nfree     211 dev/usb/usb_mem.c 	usb_blk_nfree++;