drbd: Do not try to free tl_hash in drbd_disconnect() when IO is suspended

We may not free tl_hash when IO is suspended, since we can not wait
until ap_bio_cnt reaches zero.

We can do this after susp reched 0, since then tl_clear was called

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>

4 files changed, 43 insertions, 26 deletions

diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h
index aa9bb213fe70..f84ffb17a7e5 100644
--- a/drivers/block/drbd/drbd_int.h
+++ b/drivers/block/drbd/drbd_int.h
@@ -1493,6 +1493,7 @@ extern void _drbd_wait_ee_list_empty(struct drbd_conf *mdev,
 extern void drbd_set_recv_tcq(struct drbd_conf *mdev, int tcq_enabled);
 extern void _drbd_clear_done_ee(struct drbd_conf *mdev, struct list_head *to_be_freed);
 extern void drbd_flush_workqueue(struct drbd_conf *mdev);
+extern void drbd_free_tl_hash(struct drbd_conf *mdev);
 
 /* yes, there is kernel_setsockopt, but only since 2.6.18. we don't need to
  * mess with get_fs/set_fs, we know we are KERNEL_DS always. */
diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index 9fe9bdd9e33d..8d14635e7faf 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -1409,6 +1409,10 @@ static void after_state_ch(struct drbd_conf *mdev, union drbd_state os,
             (os.user_isp && !ns.user_isp))
                 resume_next_sg(mdev);
 
+        /* free tl_hash if we Got thawed and are C_STANDALONE */
+        if (ns.conn == C_STANDALONE && ns.susp == 0 && mdev->tl_hash)
+                drbd_free_tl_hash(mdev);
+
         /* Upon network connection, we need to start the receiver */
         if (os.conn == C_STANDALONE && ns.conn == C_UNCONNECTED)
                 drbd_thread_start(&mdev->receiver);
diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c
index dc0a9acbfdf1..6c08e637e25c 100644
--- a/drivers/block/drbd/drbd_nl.c
+++ b/drivers/block/drbd/drbd_nl.c
@@ -1391,6 +1391,7 @@ static int drbd_nl_net_conf(struct drbd_conf *mdev, struct drbd_nl_cfg_req *nlp,
                 }
         }
 
+        drbd_flush_workqueue(mdev);
         spin_lock_irq(&mdev->req_lock);
         if (mdev->net_conf != NULL) {
                 retcode = ERR_NET_CONFIGURED;
@@ -1429,10 +1430,9 @@ static int drbd_nl_net_conf(struct drbd_conf *mdev, struct drbd_nl_cfg_req *nlp,
         mdev->int_dig_out=int_dig_out;
         mdev->int_dig_in=int_dig_in;
         mdev->int_dig_vv=int_dig_vv;
+        retcode = _drbd_set_state(_NS(mdev, conn, C_UNCONNECTED), CS_VERBOSE, NULL);
         spin_unlock_irq(&mdev->req_lock);
 
-        retcode = _drbd_request_state(mdev, NS(conn, C_UNCONNECTED), CS_VERBOSE);
-
         kobject_uevent(&disk_to_dev(mdev->vdisk)->kobj, KOBJ_CHANGE);
         reply->ret_code = retcode;
         drbd_reconfig_done(mdev);
diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index 22d74d79ba42..5e49ee75d3c9 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -3691,6 +3691,36 @@ void drbd_flush_workqueue(struct drbd_conf *mdev)
         wait_for_completion(&barr.done);
 }
 
+void drbd_free_tl_hash(struct drbd_conf *mdev)
+{
+        struct hlist_head *h;
+
+        spin_lock_irq(&mdev->req_lock);
+
+        if (!mdev->tl_hash || mdev->state.conn != C_STANDALONE) {
+                spin_unlock_irq(&mdev->req_lock);
+                return;
+        }
+        /* paranoia code */
+        for (h = mdev->ee_hash; h < mdev->ee_hash + mdev->ee_hash_s; h++)
+                if (h->first)
+                        dev_err(DEV, "ASSERT FAILED ee_hash[%u].first == %p, expected NULL\n",
+                                (int)(h - mdev->ee_hash), h->first);
+        kfree(mdev->ee_hash);
+        mdev->ee_hash = NULL;
+        mdev->ee_hash_s = 0;
+
+        /* paranoia code */
+        for (h = mdev->tl_hash; h < mdev->tl_hash + mdev->tl_hash_s; h++)
+                if (h->first)
+                        dev_err(DEV, "ASSERT FAILED tl_hash[%u] == %p, expected NULL\n",
+                                (int)(h - mdev->tl_hash), h->first);
+        kfree(mdev->tl_hash);
+        mdev->tl_hash = NULL;
+        mdev->tl_hash_s = 0;
+        spin_unlock_irq(&mdev->req_lock);
+}
+
 static void drbd_disconnect(struct drbd_conf *mdev)
 {
         enum drbd_fencing_p fp;
@@ -3774,32 +3804,14 @@ static void drbd_disconnect(struct drbd_conf *mdev)
         spin_unlock_irq(&mdev->req_lock);
 
         if (os.conn == C_DISCONNECTING) {
-                struct hlist_head *h;
                 wait_event(mdev->net_cnt_wait, atomic_read(&mdev->net_cnt) == 0);
 
-                /* we must not free the tl_hash
-                 * while application io is still on the fly */
-                wait_event(mdev->misc_wait, atomic_read(&mdev->ap_bio_cnt) == 0);
-
-                spin_lock_irq(&mdev->req_lock);
-                /* paranoia code */
-                for (h = mdev->ee_hash; h < mdev->ee_hash + mdev->ee_hash_s; h++)
-                        if (h->first)
-                                dev_err(DEV, "ASSERT FAILED ee_hash[%u].first == %p, expected NULL\n",
-                                                (int)(h - mdev->ee_hash), h->first);
-                kfree(mdev->ee_hash);
-                mdev->ee_hash = NULL;
-                mdev->ee_hash_s = 0;
-
-                /* paranoia code */
-                for (h = mdev->tl_hash; h < mdev->tl_hash + mdev->tl_hash_s; h++)
-                        if (h->first)
-                                dev_err(DEV, "ASSERT FAILED tl_hash[%u] == %p, expected NULL\n",
-                                                (int)(h - mdev->tl_hash), h->first);
-                kfree(mdev->tl_hash);
-                mdev->tl_hash = NULL;
-                mdev->tl_hash_s = 0;
-                spin_unlock_irq(&mdev->req_lock);
+                if (!mdev->state.susp) {
+                        /* we must not free the tl_hash
+                         * while application io is still on the fly */
+                        wait_event(mdev->misc_wait, !atomic_read(&mdev->ap_bio_cnt));
+                        drbd_free_tl_hash(mdev);
+                }
 
                 crypto_free_hash(mdev->cram_hmac_tfm);
                 mdev->cram_hmac_tfm = NULL;