On Fri, 2012-06-22 at 14:39 +0100, James Bottomley wrote: > On Wed, 2012-06-20 at 13:13 -0700, Greg KH wrote: > > On Wed, Jun 20, 2012 at 04:04:19PM -0400, Alan Stern wrote: > > > Several bug reports have been received recently for USB mass-storage > > > devices that don't handle READ CAPACITY(16) commands properly. They > > > report bogus sizes, in some cases becoming unusable as a result. > > > > > > The bugs were triggered by commit > > > 09b6b51b0b6c1b9bb61815baf205e4d74c89ff04 (SCSI & usb-storage: add > > > flags for VPD pages and REPORT LUNS), which caused usb-storage to stop > > > overriding the SCSI level reported by devices. By default, the sd > > > driver will try READ CAPACITY(16) first for any device whose level is > > > above SCSI_SPC_2. > > > > > > It seems likely that any device large enough to require the use of > > > READ CAPACITY(16) (i.e., 2 TB or more) would be able to handle READ > > > CAPACITY(10) commands properly. Indeed, I don't know of any devices > > > that don't handle READ CAPACITY(10) properly. > > > > > > Therefore this patch (as1559) adds a new flag telling the sd driver > > > to try READ CAPACITY(10) before READ CAPACITY(16), and sets this flag > > > for every USB mass-storage device. If a device really is larger than > > > 2 TB, sd will fall back to READ CAPACITY(16) just as it used to. > > > > > > This fixes Bugzilla #43391. > > > > > > Signed-off-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> > > > Acked-by: Hans de Goede <hdegoede@xxxxxxxxxx> > > > CC: "James E.J. Bottomley" <JBottomley@xxxxxxxxxxxxx> > > > CC: Matthew Dharm <mdharm-usb@xxxxxxxxxxxxxxxxxx> > > > CC: <stable@xxxxxxxxxxxxxxx> > > > > James, mind if I take this through my trees? > > Actually, you can take 1/2 but I need to do 2/2 as a postmerge. I > foresee a conflict with another patch I'm queuing that needs resolving. > > Let me know when you've got 1/2 in and I'll build the postmerge tree. Actually, forget I said this ... the postmerge has to be the other way around. James -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
