From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sagi Grimberg Subject: Re: [PATCH 02/12] scsi_transport_srp: Fix a race condition Date: Thu, 30 Apr 2015 12:44:15 +0300 Message-ID: <5541F96F.8090503@dev.mellanox.co.il> References: <5541EE21.3050809@sandisk.com> <5541EE66.7090608@sandisk.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <5541EE66.7090608-XdAiOPVOjttBDgjK7y7TUQ@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Bart Van Assche , 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 4/30/2015 11:57 AM, Bart Van Assche wrote: > Avoid that srp_terminate_io() can get invoked while srp_queuecommand() > is in progress. This patch avoids that an I/O timeout can trigger the > following kernel warning: > > WARNING: at drivers/infiniband/ulp/srp/ib_srp.c:1447 srp_terminate_io+0xef/0x100 [ib_srp]() > Call Trace: > [] dump_stack+0x4e/0x68 > [] warn_slowpath_common+0x81/0xa0 > [] warn_slowpath_null+0x1a/0x20 > [] srp_terminate_io+0xef/0x100 [ib_srp] > [] __rport_fail_io_fast+0xba/0xc0 [scsi_transport_srp] > [] rport_fast_io_fail_timedout+0xe0/0xf0 [scsi_transport_srp] > [] process_one_work+0x1db/0x780 > [] worker_thread+0x11b/0x450 > [] kthread+0xe4/0x100 > [] ret_from_fork+0x7c/0xb0 > > See also patch "scsi_transport_srp: Add transport layer error > handling" (commit ID 29c17324803c). > > Signed-off-by: Bart Van Assche > Cc: James Bottomley > Cc: Sagi Grimberg > Cc: Sebastian Parschauer > Cc: #v3.13 > --- > drivers/scsi/scsi_transport_srp.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/scsi/scsi_transport_srp.c b/drivers/scsi/scsi_transport_srp.c > index 6ce1c48..4a44337 100644 > --- a/drivers/scsi/scsi_transport_srp.c > +++ b/drivers/scsi/scsi_transport_srp.c > @@ -437,8 +437,10 @@ static void __rport_fail_io_fast(struct srp_rport *rport) > > /* Involve the LLD if possible to terminate all I/O on the rport. */ > i = to_srp_internal(shost->transportt); > - if (i->f->terminate_rport_io) > + if (i->f->terminate_rport_io) { > + srp_wait_for_queuecommand(shost); > i->f->terminate_rport_io(rport); > + } Why not just terminate the inflight IO before unblocking the target? -- 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