IB/srp: Eliminate state SRP_TARGET_DEAD
Only queue removal work after having changed the target state
into SRP_TARGET_REMOVED and not if that state was already equal
to SRP_TARGET_REMOVED. That allows us to remove the state
SRP_TARGET_DEAD. Add a call to srp_disconnect_target() in
srp_remove_target() -- due to previous changes it is now safe to
invoke that function even if the IB connection has already
been disconnected. This change allows us to replace the target
removal code in srp_remove_one() by an (indirect) call to
srp_remove_target(). Rename srp_target_port.work into
srp_target_port.remove_work to reflect its usage.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: David Dillow <dillowda@ornl.gov>
Signed-off-by: Roland Dreier <roland@purestorage.com>
diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c
index beb6878..95590a3 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -428,6 +428,23 @@
return status;
}
+static bool srp_queue_remove_work(struct srp_target_port *target)
+{
+ bool changed = false;
+
+ spin_lock_irq(&target->lock);
+ if (target->state != SRP_TARGET_REMOVED) {
+ target->state = SRP_TARGET_REMOVED;
+ changed = true;
+ }
+ spin_unlock_irq(&target->lock);
+
+ if (changed)
+ queue_work(system_long_wq, &target->remove_work);
+
+ return changed;
+}
+
static bool srp_change_conn_state(struct srp_target_port *target,
bool connected)
{
@@ -458,21 +475,6 @@
}
}
-static bool srp_change_state(struct srp_target_port *target,
- enum srp_target_state old,
- enum srp_target_state new)
-{
- bool changed = false;
-
- spin_lock_irq(&target->lock);
- if (target->state == old) {
- target->state = new;
- changed = true;
- }
- spin_unlock_irq(&target->lock);
- return changed;
-}
-
static void srp_free_req_data(struct srp_target_port *target)
{
struct ib_device *ibdev = target->srp_host->srp_dev->dev;
@@ -508,9 +510,12 @@
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_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_free_req_data(target);
@@ -520,10 +525,9 @@
static void srp_remove_work(struct work_struct *work)
{
struct srp_target_port *target =
- container_of(work, struct srp_target_port, work);
+ container_of(work, struct srp_target_port, remove_work);
- if (!srp_change_state(target, SRP_TARGET_DEAD, SRP_TARGET_REMOVED))
- return;
+ WARN_ON_ONCE(target->state != SRP_TARGET_REMOVED);
spin_lock(&target->srp_host->target_lock);
list_del(&target->list);
@@ -738,17 +742,8 @@
* However, we have to defer the real removal because we
* are in the context of the SCSI error handler now, which
* will deadlock if we call scsi_remove_host().
- *
- * Schedule our work inside the lock to avoid a race with
- * the flush_scheduled_work() in srp_remove_one().
*/
- spin_lock_irq(&target->lock);
- if (target->state == SRP_TARGET_LIVE) {
- target->state = SRP_TARGET_DEAD;
- INIT_WORK(&target->work, srp_remove_work);
- queue_work(ib_wq, &target->work);
- }
- spin_unlock_irq(&target->lock);
+ srp_queue_remove_work(target);
return ret;
}
@@ -2258,6 +2253,7 @@
sizeof (struct srp_indirect_buf) +
target->cmd_sg_cnt * sizeof (struct srp_direct_buf);
+ INIT_WORK(&target->remove_work, srp_remove_work);
spin_lock_init(&target->lock);
INIT_LIST_HEAD(&target->free_tx);
INIT_LIST_HEAD(&target->free_reqs);
@@ -2491,8 +2487,7 @@
{
struct srp_device *srp_dev;
struct srp_host *host, *tmp_host;
- LIST_HEAD(target_list);
- struct srp_target_port *target, *tmp_target;
+ struct srp_target_port *target;
srp_dev = ib_get_client_data(device, &srp_client);
@@ -2505,35 +2500,17 @@
wait_for_completion(&host->released);
/*
- * Mark all target ports as removed, so we stop queueing
- * commands and don't try to reconnect.
+ * Remove all target ports.
*/
spin_lock(&host->target_lock);
- list_for_each_entry(target, &host->target_list, list) {
- spin_lock_irq(&target->lock);
- target->state = SRP_TARGET_REMOVED;
- spin_unlock_irq(&target->lock);
- }
+ list_for_each_entry(target, &host->target_list, list)
+ srp_queue_remove_work(target);
spin_unlock(&host->target_lock);
/*
- * Wait for any reconnection tasks that may have
- * started before we marked our target ports as
- * removed, and any target port removal tasks.
+ * Wait for target port removal tasks.
*/
- flush_workqueue(ib_wq);
-
- list_for_each_entry_safe(target, tmp_target,
- &host->target_list, list) {
- srp_del_scsi_host_attr(target->scsi_host);
- 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_free_req_data(target);
- scsi_host_put(target->scsi_host);
- }
+ flush_workqueue(system_long_wq);
kfree(host);
}
diff --git a/drivers/infiniband/ulp/srp/ib_srp.h b/drivers/infiniband/ulp/srp/ib_srp.h
index ef95fa4..de2d0b3 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.h
+++ b/drivers/infiniband/ulp/srp/ib_srp.h
@@ -80,8 +80,7 @@
enum srp_target_state {
SRP_TARGET_LIVE,
- SRP_TARGET_DEAD,
- SRP_TARGET_REMOVED
+ SRP_TARGET_REMOVED,
};
enum srp_iu_type {
@@ -175,7 +174,7 @@
struct srp_iu *rx_ring[SRP_RQ_SIZE];
struct srp_request req_ring[SRP_CMD_SQ_SIZE];
- struct work_struct work;
+ struct work_struct remove_work;
struct list_head list;
struct completion done;