From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bart Van Assche Subject: Re: [PATCH 04/12] IB/srp: Fix connection state tracking Date: Tue, 5 May 2015 11:31:50 +0200 Message-ID: <55488E06.8040308@sandisk.com> References: <5541EE21.3050809@sandisk.com> <5541EE9F.8090605@sandisk.com> <5541FB3F.70902@dev.mellanox.co.il> <5542111E.1080305@sandisk.com> <5542439D.1000107@dev.mellanox.co.il> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <5542439D.1000107-LDSdmyG8hGV8YrgS2mwiifqBs+8SCbDb@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Sagi Grimberg , Doug Ledford Cc: James Bottomley , Sagi Grimberg , Sebastian Parschauer , linux-rdma , "linux-scsi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" List-Id: linux-rdma@vger.kernel.org On 04/30/15 17:00, Sagi Grimberg wrote: > On 4/30/2015 2:25 PM, Bart Van Assche wrote: >> On 04/30/15 11:51, Sagi Grimberg wrote: >>> On 4/30/2015 11:58 AM, Bart Van Assche wrote: >>>> @@ -170,6 +170,7 @@ struct srp_rdma_ch { >>>> >>>> struct completion tsk_mgmt_done; >>>> u8 tsk_mgmt_status; >>>> + bool connected; >>> >>> I generally agree with this flag, but I'm a bit confused about the >>> semantics of two connected flags? Also, we check the target connected >>> flag on TMFs, although we are executing it on a channel (should we >>> check both?) >>> >>> I'd say keep only the channel connected flag, the target logic needs to >>> be mandated by the state. >> >> I think we need both flags. The ch->connected flag is used only in >> srp_destroy_qp() to verify whether a channel has been disconnected >> before it is destroyed. The target->connected flag provides an easy way >> to test the connected state in e.g. srp_disconnect_target(). > > We can just as easily check rport state. rport state is modified before > target-connected. I still think one is redundant. Sorry but I disagree. If e.g. both the fast_io_fail and dev_loss_tmo timers have been disabled then the rport state is SRP_RPORT_RUNNING all the time. At least in that case it is not possible to derive the target->connected state from the rport state. >> And if it >> is attempted to send a task management function over a channel that has >> just been disconnected that should be fine since any channel disconnect >> causes tl_err_work to be queued. That last action will sooner or later >> result in a reconnect. > > Will it be fine to queue commands when the channel is in reconnecting > stage? As one can see in srp_reconnect_rport() the associated SCSI devices are blocked as long as a reconnect is in progress. This means that srp_queuecommand() won't be called while a reconnect is in progress. Bart. -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html