On Wed, 2014-05-14 at 15:48 -0700, Andy Grover wrote: > Just like for pSCSI, if the transport sets get_write_cache, then it is > not valid to enable write cache emulation for it. Return an error. > > see https://bugzilla.redhat.com/show_bug.cgi?id=1082675 > > Reviewed-by: Chris Leech <cleech@xxxxxxxxxx> > Signed-off-by: Andy Grover <agrover@xxxxxxxxxx> > --- > drivers/target/target_core_device.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c > index 65001e1..d461ecb 100644 > --- a/drivers/target/target_core_device.c > +++ b/drivers/target/target_core_device.c > @@ -798,10 +798,10 @@ int se_dev_set_emulate_write_cache(struct se_device *dev, int flag) > pr_err("emulate_write_cache not supported for pSCSI\n"); > return -EINVAL; > } > - if (dev->transport->get_write_cache) { > - pr_warn("emulate_write_cache cannot be changed when underlying" > - " HW reports WriteCacheEnabled, ignoring request\n"); > - return 0; > + if (flag && > + dev->transport->get_write_cache) { > + pr_err("emulate_write_cache not supported for this device\n"); > + return -EINVAL; > } > > dev->dev_attrib.emulate_write_cache = flag; Allowing the target WCE bit to be disabled when the underlying device has WCE enabled is a recipe for disaster. How is the initiator supposed to know when to flush writes if the target is telling it that WCE is disabled. I'll take change to return -EINVAL here, but the other part is dangerous and wrong. --nab -- 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
