drbd: Track the reasons to suspend IO in dedicated state bits

There are three ways to get IO suspended:

 * Loss of any access to data
 * Fence-peer-handler running
 * User requested to suspend IO

Track those in different bits, so that one condition clearing its
state bit does not interfere with the other two conditions.

Only when the user resumes IO he overrules all three bits.

The fact is hidden from the user, he sees only a single suspend
bit.

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

1 files changed, 14 insertions, 6 deletions

diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c
index 5b30f90cab3e..9ee44568dce3 100644
--- a/drivers/block/drbd/drbd_nl.c
+++ b/drivers/block/drbd/drbd_nl.c
@@ -209,7 +209,8 @@ enum drbd_disk_state drbd_try_outdate_peer(struct drbd_conf *mdev)
                 put_ldev(mdev);
         } else {
                 dev_warn(DEV, "Not fencing peer, I'm not even Consistent myself.\n");
-                return mdev->state.pdsk;
+                nps = mdev->state.pdsk;
+                goto out;
         }
 
         r = drbd_khelper(mdev, "fence-peer");
@@ -256,6 +257,14 @@ enum drbd_disk_state drbd_try_outdate_peer(struct drbd_conf *mdev)
 
         dev_info(DEV, "fence-peer helper returned %d (%s)\n",
                         (r>>8) & 0xff, ex_to_string);
+
+out:
+        if (mdev->state.susp_fen && nps >= D_UNKNOWN) {
+                /* The handler was not successful... unfreeze here, the
+                   state engine can not unfreeze... */
+                _drbd_request_state(mdev, NS(susp_fen, 0), CS_VERBOSE);
+        }
+
         return nps;
 }
 
@@ -550,7 +559,7 @@ char *ppsize(char *buf, unsigned long long size)
 void drbd_suspend_io(struct drbd_conf *mdev)
 {
         set_bit(SUSPEND_IO, &mdev->flags);
-        if (mdev->state.susp)
+        if (is_susp(mdev->state))
                 return;
         wait_event(mdev->misc_wait, !atomic_read(&mdev->ap_bio_cnt));
 }
@@ -1016,7 +1025,7 @@ static int drbd_nl_disk_conf(struct drbd_conf *mdev, struct drbd_nl_cfg_req *nlp
 
         drbd_suspend_io(mdev);
         /* also wait for the last barrier ack. */
-        wait_event(mdev->misc_wait, !atomic_read(&mdev->ap_pending_cnt) || mdev->state.susp);
+        wait_event(mdev->misc_wait, !atomic_read(&mdev->ap_pending_cnt) || is_susp(mdev->state));
         /* and for any other previously queued work */
         drbd_flush_workqueue(mdev);
 
@@ -1114,8 +1123,7 @@ static int drbd_nl_disk_conf(struct drbd_conf *mdev, struct drbd_nl_cfg_req *nlp
                 clear_bit(CRASHED_PRIMARY, &mdev->flags);
 
         if (drbd_md_test_flag(mdev->ldev, MDF_PRIMARY_IND) &&
-            !(mdev->state.role == R_PRIMARY && mdev->state.susp &&
-              mdev->sync_conf.on_no_data == OND_SUSPEND_IO)) {
+            !(mdev->state.role == R_PRIMARY && mdev->state.susp_nod)) {
                 set_bit(CRASHED_PRIMARY, &mdev->flags);
                 cp_discovered = 1;
         }
@@ -1939,7 +1947,7 @@ static int drbd_nl_resume_io(struct drbd_conf *mdev, struct drbd_nl_cfg_req *nlp
                 drbd_md_sync(mdev);
         }
         drbd_suspend_io(mdev);
-        reply->ret_code = drbd_request_state(mdev, NS(susp, 0));
+        reply->ret_code = drbd_request_state(mdev, NS3(susp, 0, susp_nod, 0, susp_fen, 0));
         if (reply->ret_code == SS_SUCCESS) {
                 if (mdev->state.conn < C_CONNECTED)
                         tl_clear(mdev);