On Tue, 2013-01-08 at 19:56 -0800, Roland Dreier wrote: > On Tue, Jan 8, 2013 at 7:48 PM, Nicholas A. Bellinger > <nab@xxxxxxxxxxxxxxx> wrote: > > Digging into this a bit more, I'm starting to think the root problem is > > that the CMD_T_ACTIVE bit in se_cmd->transport_state is getting cleared > > by transport_cmd_check_stop() during transport_generic_new_cmd() for > > pending WRITEs before the cmd->se_tfo->write_pending() callback occurs, > > but is not getting reset until way too late in target_complete_cmd(). > > > > This bit used to be set each time in transport_add_cmd_to_queue() when a > > se_cmd was added to the legacy transport_processing_thread() logic > > (including for iSCSI WRITEs), but this has since been removed starting > > from v3.6 code. (Here is the v3.5.x reference for good measure) > > > > http://git.kernel.org/?p=linux/kernel/git/stable/linux-stable.git;a=blob;f=drivers/target/target_core_transport.c;h=0981707216b7f937db1b7a6931b9df113048ecef;hb=refs/heads/linux-3.5.y#l600 > > > > So here is a quick patch to explicitly re-set CMD_T_ACTIVE within > > target_execute_cmd(), which is the function that iscsi-target now calls > > in >= v3.6.x to submit individual WRITEs once the full data payload has > > been received. > > > > diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c > > index 978762d..1689c8b 100644 > > --- a/drivers/target/target_core_transport.c > > +++ b/drivers/target/target_core_transport.c > > @@ -1687,6 +1687,7 @@ void target_execute_cmd(struct se_cmd *cmd) > > return; > > } > > > > + cmd->transport_state |= CMD_T_ACTIVE; > > cmd->t_state = TRANSPORT_PROCESSING; > > spin_unlock_irq(&cmd->t_state_lock); > > Yes, I sent the same patch last week. <nod>, sorry still catching up on the backlog + busy on WIP v3.9 iSER-target bits. ;) > Not sure if it fixes the crash in this mail thread, but see > http://permalink.gmane.org/gmane.linux.scsi/79495 (or your backlog of > target-devel mail) for a detailed explanation of another reason why > it's needed. I'm quite certain at this point that Martin's active I/O shutdown OOPsen here is due to the same >= v3.6 regression bug of CMD_T_ACTIVE not being re-set during pending WRITEs I/O submission. So that said, I'll finish catching up tomorrow and end up applying your patch as the proper fix for mainline. Thanks Roland! --nab -- To unsubscribe from this list: send the line "unsubscribe target-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
