On Mon, Nov 23, 2009 at 02:50:22PM -0500, tm@ wrote: > On Mon, Nov 23, 2009 at 07:54:50PM +0100, Jan Kara wrote: > > On Mon 23-11-09 13:20:26, Alan Stern wrote: > > > On Mon, 23 Nov 2009, Jan Kara wrote: > > > > > > > On Mon 23-11-09 10:06:03, Alan Stern wrote: > > > > > On Mon, 23 Nov 2009, Jan Kara wrote: > > > > > > > > > > > Yeah, from what you write, it looks like USB enclosure is at fault (or it > > > > > > could still be your USB controller but I doubt it). It's still a bit > > > > > > bothering that the error reported by the drive was not properly propagated > > > > > > up to VFS. Either it's some block layer retry/ignore magic that I missed or > > > > > > we ignore errors from block layer in some place. > > > > > > > > > > Is there any interest in tracking this down? It's not hard to find out > > > > > what low-level errors are being reported and to generate them on demand > > > > > with an emulated USB disk drive. > > > > Well, if you could provide me with the patch, I could try to track down > > > > why the errors aren't propagated... It would be interesting because if it's > > > > not some retry logic in block layer, it's a bug in VFS ;). > > > > > > I can't provide a patch without first knowing what the errors are. The > > > way to find out is to use usbmon. See Documentation/usb/usbmon.txt for > > > instructions. > > Ah, OK. The problem manifests itself as an error in SATA communication > > (which in fact somehow happens over USB, but I don't really know the > > details of mass storage over USB) so debugging USB would become actual only > > if we found out it's really some bug in an usb stack. But so far the most > > probable is just an error somewhere between the USB controller in the > > enclosure and the drive itself. BTW: Is the data transferred over USB > > checksummed? > > > > Honza > Mind that this is an ide hard drive in a usb enclosure, not sata. > The error reported is bizzare. I don't know if I'll be able to get the > enclosure to cause the error on demand, but before I try supergluing it, > I'll try to do whatever I need to do with usbmon so we can get the error > that's actually happening so you can do whatever you need to do to track it > down :) > > Tim McGrath Uhh, this could be a problem. CONFIG_USB_MON=y is set in my .config BUT, although I followed the directions and debugfs is mounted, root@roll:/home/tm# mount /dev/root on / type ext4 (rw,relatime,barrier=1,data=ordered,data_err=abort) proc on /proc type proc (rw) sysfs on /sys type sysfs (rw) usbfs on /proc/bus/usb type usbfs (rw) none_debugs on /sys/kernel/debug type debugfs (rw) I receive this message when I test if usbmon's directory exists: root@roll:/home/tm# ls /sys/kernel/debug/usbmon ls: cannot access /sys/kernel/debug/usbmon: No such file or directory According to the kernel documentation usbmon should be loaded already. Help? Timothy McGrath -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
