This is a break-out and slight cleanup of Bart Van Assche's work.
---
drivers/infiniband/ulp/srp/ib_srp.c | 45 ++++++++++++++++++----------------
1 files changed, 24 insertions(+), 21 deletions(-)
diff --git a/drivers/infiniband/ulp/srp/ib_srp.c
b/drivers/infiniband/ulp/srp/ib_srp.c
index 95fb9f0..a14975b 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -441,18 +441,28 @@ static void srp_disconnect_target(struct srp_target_port
*target)
wait_for_completion(&target->done);
}
+static bool srp_change_state(struct srp_target_port *target,
+ enum srp_target_state old,
+ enum srp_target_state new)
+{
+ int changed = false;
+
+ spin_lock_irq(target->scsi_host->host_lock);
+ if (target->state == old) {
+ target->state = new;
+ changed = true;
+ }
+ spin_unlock_irq(target->scsi_host->host_lock);
+ return changed;
+}
+
static void srp_remove_work(struct work_struct *work)
{
struct srp_target_port *target =
container_of(work, struct srp_target_port, work);
- spin_lock_irq(target->scsi_host->host_lock);
- if (target->state != SRP_TARGET_DEAD) {
- spin_unlock_irq(target->scsi_host->host_lock);
+ if (!srp_change_state(target, SRP_TARGET_DEAD, SRP_TARGET_REMOVED))
return;
- }
- target->state = SRP_TARGET_REMOVED;
- spin_unlock_irq(target->scsi_host->host_lock);
spin_lock(&target->srp_host->target_lock);
list_del(&target->list);
@@ -560,13 +570,8 @@ static int srp_reconnect_target(struct srp_target_port
*target)
struct ib_wc wc;
int ret;
- spin_lock_irq(target->scsi_host->host_lock);
- if (target->state != SRP_TARGET_LIVE) {
- spin_unlock_irq(target->scsi_host->host_lock);
+ if (!srp_change_state(target, SRP_TARGET_LIVE, SRP_TARGET_CONNECTING))
return -EAGAIN;
- }
- target->state = SRP_TARGET_CONNECTING;
- spin_unlock_irq(target->scsi_host->host_lock);
srp_disconnect_target(target);
/*
@@ -605,13 +610,8 @@ static int srp_reconnect_target(struct srp_target_port
*target)
if (ret)
goto err;
- spin_lock_irq(target->scsi_host->host_lock);
- if (target->state == SRP_TARGET_CONNECTING) {
- ret = 0;
- target->state = SRP_TARGET_LIVE;
- } else
+ if (!srp_change_state(target, SRP_TARGET_CONNECTING, SRP_TARGET_LIVE))
ret = -EAGAIN;
- spin_unlock_irq(target->scsi_host->host_lock);
return ret;
@@ -621,9 +621,12 @@ err:
/*
* We couldn't reconnect, so kill our target port off.
- * However, we have to defer the real removal because we might
- * be in the context of the SCSI error handler now, which
- * would deadlock if we call scsi_remove_host().
+ * 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->scsi_host->host_lock);
if (target->state == SRP_TARGET_CONNECTING) {
--
1.7.2.3
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