On Wed, 23 May 2012, Pantelis Antoniou wrote: > > I don't believe that. Are you sure you haven't mixed up unmounting and > > ejecting? > > > > I'm using the Finder; I don't fiddle with the command line. > > I see an eject icon, I press it, and the disk should umount/eject. Is that any different from dragging the disk's icon to the trashcan? > On the Mac it's all integrated, there's no separate unmount/eject steps. > > Speaking of which, I did try to replicate the behavior of the Mac on Linux. > > Using udisks to send a detach command I get to see this on the console: > > > May 23 17:55:48 beagleboard [ 335.725341] lun0: unload attempt prevented > > May 23 17:55:48 beagleboard [ 335.725372] gadget: sending command-failure status > > > > And this is the result on the host: > > > root@ubuntu:~# sudo udisks --detach /dev/sdb > > Detach failed: Error detaching: helper exited with exit code 1: Detaching device /dev/sdb > > USB device: /sys/devices/pci0000:00/0000:00:11.0/0000:02:03.0/usb1/1-1) > > SYNCHRONIZE CACHE: OK > > STOP UNIT: FAILED: No such file or directory > > > > So udisks does send a STOP UNIT command too. Which fails because there was > a previous command that disallowed media unmounting. There is no such command. However there is a command that prevents media _unloading_. If you unmount all the filesystems on the device first, unloading will be allowed again. The "eject" command will do both for you. > I does sound like we have a code path (STOP UNIT command) that wasn't been > exercised at all on Linux hosts, but on the Mac it is being exercised with > unexpected results. It _has_ been exercised on Linux hosts. I tested it when it was originally written. > > For example, what happens when you plug in a regular USB flash memory > > stick to an OS-X system? Many of them them are not removable. (More > > accurately, none of them are removable and many of them -- but not all! > > -- correctly tell the host that they aren't.) Is it then impossible to > > unmount such a flash drive? > > > > Most of the USB flash memory sticks I've used on the Mac operate perfectly fine. > > You click the eject button and they unmount cleanly. There is a strong case to > be made that a Linux based device that presents a mass memory interface should work > in the same manner. Indeed, the mass-storage gadgets are supposed to present the same interface and behave in the same manner. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
