IB/srpt: Wait until channel release has finished during module unload

Introduce the helper function srpt_set_enabled(). Protect
sport->enabled changes with sdev->mutex. Makes configfs writes
into 'enabled' wait until all channel resources have been freed.
Wait until channel release has finished during kernel module
unload.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

diff --git a/drivers/infiniband/ulp/srpt/ib_srpt.c b/drivers/infiniband/ulp/srpt/ib_srpt.c
index 1aeb8d6..ca602eb 100644 (file)
--- a/drivers/infiniband/ulp/srpt/ib_srpt.c
+++ b/drivers/infiniband/ulp/srpt/ib_srpt.c
@@ -1821,19 +1821,31 @@ out:
        return wait;
 }
 
-static void __srpt_close_all_ch(struct srpt_device *sdev)
+static void srpt_set_enabled(struct srpt_port *sport, bool enabled)
+       __must_hold(&sdev->mutex)
 {
+       struct srpt_device *sdev = sport->sdev;
        struct srpt_rdma_ch *ch;
 
        lockdep_assert_held(&sdev->mutex);
 
+       if (sport->enabled == enabled)
+               return;
+       sport->enabled = enabled;
+       if (sport->enabled)
+               return;
+
+again:
        list_for_each_entry(ch, &sdev->rch_list, list) {
-               if (srpt_disconnect_ch(ch) >= 0)
-                       pr_info("Closing channel %s-%d because target %s has been disabled\n",
-                               ch->sess_name, ch->qp->qp_num,
-                               sdev->device->name);
-               srpt_close_ch(ch);
+               if (ch->sport == sport) {
+                       pr_info("%s: closing channel %s-%d\n",
+                               sdev->device->name, ch->sess_name,
+                               ch->qp->qp_num);
+                       if (srpt_disconnect_ch_sync(ch))
+                               goto again;
+               }
        }
+
 }
 
 static void srpt_free_ch(struct kref *kref)
@@ -2496,8 +2508,7 @@ static int srpt_release_sdev(struct srpt_device *sdev)
 
        mutex_lock(&sdev->mutex);
        for (i = 0; i < ARRAY_SIZE(sdev->port); i++)
-               sdev->port[i].enabled = false;
-       __srpt_close_all_ch(sdev);
+               srpt_set_enabled(&sdev->port[i], false);
        mutex_unlock(&sdev->mutex);
 
        res = wait_event_interruptible(sdev->ch_releaseQ,
@@ -3083,7 +3094,6 @@ static ssize_t srpt_tpg_enable_store(struct config_item *item,
        struct se_portal_group *se_tpg = to_tpg(item);
        struct srpt_port *sport = srpt_tpg_to_sport(se_tpg);
        struct srpt_device *sdev = sport->sdev;
-       struct srpt_rdma_ch *ch;
        unsigned long tmp;
         int ret;
 
@@ -3097,24 +3107,11 @@ static ssize_t srpt_tpg_enable_store(struct config_item *item,
                pr_err("Illegal value for srpt_tpg_store_enable: %lu\n", tmp);
                return -EINVAL;
        }
-       if (sport->enabled == tmp)
-               goto out;
-       sport->enabled = tmp;
-       if (sport->enabled)
-               goto out;
 
        mutex_lock(&sdev->mutex);
-       list_for_each_entry(ch, &sdev->rch_list, list) {
-               if (ch->sport == sport) {
-                       pr_debug("%s: ch %p %s-%d\n", __func__, ch,
-                                ch->sess_name, ch->qp->qp_num);
-                       srpt_disconnect_ch(ch);
-                       srpt_close_ch(ch);
-               }
-       }
+       srpt_set_enabled(sport, tmp);
        mutex_unlock(&sdev->mutex);
 
-out:
        return count;
 }