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authorBart Van Assche <bvanassche@acm.org>2010-11-26 18:13:06 (GMT)
committerDavid Dillow <dillowda@ornl.gov>2011-01-05 20:24:25 (GMT)
commit9709f0e05b827049733f439de82a4a1688b37b86 (patch)
tree62bf3010092a46c6971eaef148719eee59d85074 /drivers
parentf8b6e31e4e46bf514c27fce38783ed5615cca01d (diff)
downloadlinux-fsl-qoriq-9709f0e05b827049733f439de82a4a1688b37b86.tar.xz
IB/srp: consolidate state change code
Signed-off-by: Bart Van Assche <bvanassche@acm.org> [ broken out and small cleanups by David Dillow ] Signed-off-by: David Dillow <dillowda@ornl.gov>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/infiniband/ulp/srp/ib_srp.c45
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 29429a1..def9e6b 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)
+{
+ bool 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) {