On Mon, 2011-12-12 at 16:48 +0530, Amit Sahrawat wrote: > It has been observed that a number of USB HDD's do not respond correctly > to SCSI mode sense command(retrieve caching pages) which results in their > Write Cache being discarded by queue requests i.e., WCE if left set to > '0'(disabled). > This results in a number of Filesystem corruptions, when the device > is unplugged abruptly. Um, how would knowing the caching type correctly help? If you surprise unplug the device, we can't send a flush to it anyway ... > So, in order to identify the devices correctly - give it > a last try using ATA_16 after failure from normal routine. > Introduce a mechanism to store write-cache type using /sys/class/ > interface, so that the normal code continues to function without errors. > > Signed-off-by: Amit Sahrawat <amit.sahrawat83@xxxxxxxxx> > Signed-off-by: Nam-Jae Jeon <namjae.jeon@xxxxxxxxxxx> This whole patch looks like a layering violation. Why not just update the SAT layer to translate the MODE SENSE correctly? 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
