On Wed, 19 Nov 2014, Christoph Hellwig wrote: > On Sat, Nov 15, 2014 at 08:14:57PM -0500, Jeff DeFouw wrote: > > Kernel 3.16 includes commit > > 89fb4cd1f717a871ef79fa7debbe840e3225cd54 > > scsi: handle flush errors properly > > > > I have an old USB backup drive that indicates a write cache but does not > > support Synchronize Cache(10). The request error now gets returned, > > resulting in a journal abort and inability to write to the ext3 > > filesystem. I was able to work around the problem by adding a new USB > > storage quirk that completes the request without contacting the drive. > > Is it acceptable for a drive to respond this way, and therefore need to > > be handled in the SCSI layer, or is a new USB storage quirk the right > > way to go? > > Maybe the problem is that usb-storage sets the wce_default_on flag, and > we thus send a SYNCHRONIZE_CACHE even if the devices never claimed to > support it? usb-storage sets wce_default_on only for devices that are marked with the US_FL_WRITE_CACHE quirk flag. Currently only two devices have that flag: the Seagate Portable HDD (vendor ID 0x0bc2, product ID 0x2300) and the Western Digital My Password HDD (vendor ID 0x1058, product ID 0x070a). > Adding the Alan Stern -- 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
