From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bart Van Assche Subject: [PATCH 02/10] IB/srp: Keep rport as long as the IB transport layer Date: Thu, 10 Oct 2013 14:10:54 +0200 Message-ID: <5256994E.5070504@acm.org> References: <52569806.9080201@acm.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from georges.telenet-ops.be ([195.130.137.68]:35502 "EHLO georges.telenet-ops.be" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754871Ab3JJMK4 (ORCPT ); Thu, 10 Oct 2013 08:10:56 -0400 In-Reply-To: <52569806.9080201@acm.org> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: David Dillow , Roland Dreier , Vu Pham , Sebastian Riemer , linux-rdma , linux-scsi , James Bottomley Keep the rport data structure around after srp_remove_host() has finished until cleanup of the IB transport layer has finished completely. This is necessary because later patches use the rport pointer inside the queuecommand callback. Without this patch accessing the rport from inside a queuecommand callback is racy because srp_remove_host() must be invoked before scsi_remove_host() and because the queuecommand callback could get invoked after srp_remove_host() has finished. In other words, without this patch the queuecommand callback can get invoked after the rport data structure has been freed. Signed-off-by: Bart Van Assche Cc: David Dillow Cc: Roland Dreier Cc: James Bottomley Cc: Vu Pham Cc: Sebastian Riemer --- drivers/infiniband/ulp/srp/ib_srp.c | 3 +++ drivers/infiniband/ulp/srp/ib_srp.h | 1 + drivers/scsi/scsi_transport_srp.c | 18 ++++++++++++++++++ include/scsi/scsi_transport_srp.h | 2 ++ 4 files changed, 24 insertions(+) diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c index aed5b75..414fd02 100644 --- a/drivers/infiniband/ulp/srp/ib_srp.c +++ b/drivers/infiniband/ulp/srp/ib_srp.c @@ -528,11 +528,13 @@ static void srp_remove_target(struct srp_target_port *target) WARN_ON_ONCE(target->state != SRP_TARGET_REMOVED); srp_del_scsi_host_attr(target->scsi_host); + srp_rport_get(target->rport); srp_remove_host(target->scsi_host); scsi_remove_host(target->scsi_host); srp_disconnect_target(target); ib_destroy_cm_id(target->cm_id); srp_free_target_ib(target); + srp_rport_put(target->rport); srp_free_req_data(target); spin_lock(&target->srp_host->target_lock); @@ -2004,6 +2006,7 @@ static int srp_add_target(struct srp_host *host, struct srp_target_port *target) } rport->lld_data = target; + target->rport = rport; spin_lock(&host->target_lock); list_add_tail(&target->list, &host->target_list); diff --git a/drivers/infiniband/ulp/srp/ib_srp.h b/drivers/infiniband/ulp/srp/ib_srp.h index 84d821b..2a1768f 100644 --- a/drivers/infiniband/ulp/srp/ib_srp.h +++ b/drivers/infiniband/ulp/srp/ib_srp.h @@ -153,6 +153,7 @@ struct srp_target_port { u16 io_class; struct srp_host *srp_host; struct Scsi_Host *scsi_host; + struct srp_rport *rport; char target_name[32]; unsigned int scsi_id; unsigned int sg_tablesize; diff --git a/drivers/scsi/scsi_transport_srp.c b/drivers/scsi/scsi_transport_srp.c index f379c7f..f7ba94a 100644 --- a/drivers/scsi/scsi_transport_srp.c +++ b/drivers/scsi/scsi_transport_srp.c @@ -185,6 +185,24 @@ static int srp_host_match(struct attribute_container *cont, struct device *dev) } /** + * srp_rport_get() - increment rport reference count + */ +void srp_rport_get(struct srp_rport *rport) +{ + get_device(&rport->dev); +} +EXPORT_SYMBOL(srp_rport_get); + +/** + * srp_rport_put() - decrement rport reference count + */ +void srp_rport_put(struct srp_rport *rport) +{ + put_device(&rport->dev); +} +EXPORT_SYMBOL(srp_rport_put); + +/** * srp_rport_add - add a SRP remote port to the device hierarchy * @shost: scsi host the remote port is connected to. * @ids: The port id for the remote port. diff --git a/include/scsi/scsi_transport_srp.h b/include/scsi/scsi_transport_srp.h index ff0f04a..5a2d2d1 100644 --- a/include/scsi/scsi_transport_srp.h +++ b/include/scsi/scsi_transport_srp.h @@ -38,6 +38,8 @@ extern struct scsi_transport_template * srp_attach_transport(struct srp_function_template *); extern void srp_release_transport(struct scsi_transport_template *); +extern void srp_rport_get(struct srp_rport *rport); +extern void srp_rport_put(struct srp_rport *rport); extern struct srp_rport *srp_rport_add(struct Scsi_Host *, struct srp_rport_identifiers *); extern void srp_rport_del(struct srp_rport *); -- 1.8.1.4