| Message ID | 5541EE66.7090608@sandisk.com (mailing list archive) |
|---|---|
| State | Rejected |
| Headers | show |
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: > [<ffffffff814c65a2>] dump_stack+0x4e/0x68 > [<ffffffff81051f71>] warn_slowpath_common+0x81/0xa0 > [<ffffffff8105204a>] warn_slowpath_null+0x1a/0x20 > [<ffffffffa075f51f>] srp_terminate_io+0xef/0x100 [ib_srp] > [<ffffffffa07495da>] __rport_fail_io_fast+0xba/0xc0 [scsi_transport_srp] > [<ffffffffa0749a90>] rport_fast_io_fail_timedout+0xe0/0xf0 [scsi_transport_srp] > [<ffffffff8106e09b>] process_one_work+0x1db/0x780 > [<ffffffff8106e75b>] worker_thread+0x11b/0x450 > [<ffffffff81073c64>] kthread+0xe4/0x100 > [<ffffffff814cf26c>] 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 <bart.vanassche@sandisk.com> > Cc: James Bottomley <JBottomley@Odin.com> > Cc: Sagi Grimberg <sagig@mellanox.com> > Cc: Sebastian Parschauer <sebastian.riemer@profitbricks.com> > Cc: <stable@vger.kernel.org> #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@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 04/30/15 11:44, Sagi Grimberg wrote: > 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: >> [<ffffffff814c65a2>] dump_stack+0x4e/0x68 >> [<ffffffff81051f71>] warn_slowpath_common+0x81/0xa0 >> [<ffffffff8105204a>] warn_slowpath_null+0x1a/0x20 >> [<ffffffffa075f51f>] srp_terminate_io+0xef/0x100 [ib_srp] >> [<ffffffffa07495da>] __rport_fail_io_fast+0xba/0xc0 >> [scsi_transport_srp] >> [<ffffffffa0749a90>] rport_fast_io_fail_timedout+0xe0/0xf0 >> [scsi_transport_srp] >> [<ffffffff8106e09b>] process_one_work+0x1db/0x780 >> [<ffffffff8106e75b>] worker_thread+0x11b/0x450 >> [<ffffffff81073c64>] kthread+0xe4/0x100 >> [<ffffffff814cf26c>] 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 <bart.vanassche@sandisk.com> >> Cc: James Bottomley <JBottomley@Odin.com> >> Cc: Sagi Grimberg <sagig@mellanox.com> >> Cc: Sebastian Parschauer <sebastian.riemer@profitbricks.com> >> Cc: <stable@vger.kernel.org> #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? Sorry but I don't think that would prevent the described race condition. The call trace in the description of this patch illustrates that srp_queuecommand() can still be active even after the transport state has been changed into "offline". Hence if terminate_rport_io() would be invoked earlier the same race would still exist. Bart. -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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); + } } /**
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: [<ffffffff814c65a2>] dump_stack+0x4e/0x68 [<ffffffff81051f71>] warn_slowpath_common+0x81/0xa0 [<ffffffff8105204a>] warn_slowpath_null+0x1a/0x20 [<ffffffffa075f51f>] srp_terminate_io+0xef/0x100 [ib_srp] [<ffffffffa07495da>] __rport_fail_io_fast+0xba/0xc0 [scsi_transport_srp] [<ffffffffa0749a90>] rport_fast_io_fail_timedout+0xe0/0xf0 [scsi_transport_srp] [<ffffffff8106e09b>] process_one_work+0x1db/0x780 [<ffffffff8106e75b>] worker_thread+0x11b/0x450 [<ffffffff81073c64>] kthread+0xe4/0x100 [<ffffffff814cf26c>] 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 <bart.vanassche@sandisk.com> Cc: James Bottomley <JBottomley@Odin.com> Cc: Sagi Grimberg <sagig@mellanox.com> Cc: Sebastian Parschauer <sebastian.riemer@profitbricks.com> Cc: <stable@vger.kernel.org> #v3.13 --- drivers/scsi/scsi_transport_srp.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)