drbd: Consider the disk-timeout also for meta-data IO operations

If the backing device is already frozen during attach, we failed
to recognize that. The current disk-timeout code works on top
of the drbd_request objects. During attach we do not allow IO
and therefore never generate a drbd_request object but block
before that in drbd_make_request().

This patch adds the timeout to all drbd_md_sync_page_io().

Before this patch we used to go from D_ATTACHING directly
to D_DISKLESS if IO failed during attach. We can no longer
do this since we have to stay in D_FAILED until all IO
ops issued to the backing device returned.

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

4 files changed, 45 insertions, 39 deletions

diff --git a/drivers/block/drbd/drbd_actlog.c b/drivers/block/drbd/drbd_actlog.c
index 601ad9ef0437..08bd7c1b36e1 100644
--- a/drivers/block/drbd/drbd_actlog.c
+++ b/drivers/block/drbd/drbd_actlog.c
@@ -88,9 +88,16 @@ static bool md_io_allowed(struct drbd_conf *mdev)
         return ds >= D_NEGOTIATING || ds == D_ATTACHING;
 }
 
-void wait_until_done_or_disk_failure(struct drbd_conf *mdev, unsigned int *done)
+void wait_until_done_or_disk_failure(struct drbd_conf *mdev, struct drbd_backing_dev *bdev,
+                                     unsigned int *done)
 {
-        wait_event(mdev->misc_wait, *done || !md_io_allowed(mdev));
+        long dt = bdev->dc.disk_timeout * HZ / 10;
+        if (dt == 0)
+                dt = MAX_SCHEDULE_TIMEOUT;
+
+        dt = wait_event_timeout(mdev->misc_wait, *done || !md_io_allowed(mdev), dt);
+        if (dt == 0)
+                dev_err(DEV, "meta-data IO operation timed out\n");
 }
 
 static int _drbd_md_sync_page_io(struct drbd_conf *mdev,
@@ -130,7 +137,7 @@ static int _drbd_md_sync_page_io(struct drbd_conf *mdev,
                 bio_endio(bio, -EIO);
         else
                 submit_bio(rw, bio);
-        wait_until_done_or_disk_failure(mdev, &mdev->md_io.done);
+        wait_until_done_or_disk_failure(mdev, bdev, &mdev->md_io.done);
         ok = bio_flagged(bio, BIO_UPTODATE) && mdev->md_io.error == 0;
 
  out:
diff --git a/drivers/block/drbd/drbd_bitmap.c b/drivers/block/drbd/drbd_bitmap.c
index 9611db43cc7a..49603bc67fe4 100644
--- a/drivers/block/drbd/drbd_bitmap.c
+++ b/drivers/block/drbd/drbd_bitmap.c
@@ -1088,7 +1088,7 @@ static int bm_rw(struct drbd_conf *mdev, int rw, unsigned lazy_writeout_upper_id
          * "in_flight reached zero, all done" event.
          */
         if (!atomic_dec_and_test(&ctx->in_flight))
-                wait_until_done_or_disk_failure(mdev, &ctx->done);
+                wait_until_done_or_disk_failure(mdev, mdev->ldev, &ctx->done);
         else
                 kref_put(&ctx->kref, &bm_aio_ctx_destroy);
 
@@ -1195,7 +1195,7 @@ int drbd_bm_write_page(struct drbd_conf *mdev, unsigned int idx) __must_hold(loc
         }
 
         bm_page_io_async(ctx, idx, WRITE_SYNC);
-        wait_until_done_or_disk_failure(mdev, &ctx->done);
+        wait_until_done_or_disk_failure(mdev, mdev->ldev, &ctx->done);
 
         if (ctx->error)
                 drbd_chk_io_error(mdev, 1, true);
diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h
index 31dee20f3411..fe5797f73d88 100644
--- a/drivers/block/drbd/drbd_int.h
+++ b/drivers/block/drbd/drbd_int.h
@@ -1541,7 +1541,8 @@ extern void *drbd_md_get_buffer(struct drbd_conf *mdev);
 extern void drbd_md_put_buffer(struct drbd_conf *mdev);
 extern int drbd_md_sync_page_io(struct drbd_conf *mdev,
                                 struct drbd_backing_dev *bdev, sector_t sector, int rw);
-extern void wait_until_done_or_disk_failure(struct drbd_conf *mdev, unsigned int *done);
+extern void wait_until_done_or_disk_failure(struct drbd_conf *mdev, struct drbd_backing_dev *bdev,
+                                            unsigned int *done);
 extern void drbd_ov_oos_found(struct drbd_conf*, sector_t, int);
 extern void drbd_rs_controller_reset(struct drbd_conf *mdev);
 
diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index b2c0e5f0d52c..8ca8925520ad 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -916,11 +916,6 @@ static union drbd_state sanitize_state(struct drbd_conf *mdev, union drbd_state
         if (ns.disk == D_FAILED && os.disk == D_DISKLESS)
                 ns.disk = D_DISKLESS;
 
-        /* if we are only D_ATTACHING yet,
-         * we can (and should) go directly to D_DISKLESS. */
-        if (ns.disk == D_FAILED && os.disk == D_ATTACHING)
-                ns.disk = D_DISKLESS;
-
         /* After C_DISCONNECTING only C_STANDALONE may follow */
         if (os.conn == C_DISCONNECTING && ns.conn != C_STANDALONE)
                 ns.conn = os.conn;
@@ -1592,35 +1587,38 @@ static void after_state_ch(struct drbd_conf *mdev, union drbd_state os,
         /* first half of local IO error, failure to attach,
          * or administrative detach */
         if (os.disk != D_FAILED && ns.disk == D_FAILED) {
-                enum drbd_io_error_p eh;
-                int was_io_error;
+                enum drbd_io_error_p eh = EP_PASS_ON;
+                int was_io_error = 0;
                 /* corresponding get_ldev was in __drbd_set_state, to serialize
-                 * our cleanup here with the transition to D_DISKLESS,
-                 * so it is safe to dreference ldev here. */
-                eh = mdev->ldev->dc.on_io_error;
-                was_io_error = test_and_clear_bit(WAS_IO_ERROR, &mdev->flags);
-
-                /* Immediately allow completion of all application IO, that waits
-                   for completion from the local disk. */
-                tl_abort_disk_io(mdev);
-
-                /* current state still has to be D_FAILED,
-                 * there is only one way out: to D_DISKLESS,
-                 * and that may only happen after our put_ldev below. */
-                if (mdev->state.disk != D_FAILED)
-                        dev_err(DEV,
-                                "ASSERT FAILED: disk is %s during detach\n",
-                                drbd_disk_str(mdev->state.disk));
-
-                if (ns.conn >= C_CONNECTED)
-                        drbd_send_state(mdev, ns);
-
-                drbd_rs_cancel_all(mdev);
-
-                /* In case we want to get something to stable storage still,
-                 * this may be the last chance.
-                 * Following put_ldev may transition to D_DISKLESS. */
-                drbd_md_sync(mdev);
+                 * our cleanup here with the transition to D_DISKLESS.
+                 * But is is still not save to dreference ldev here, since
+                 * we might come from an failed Attach before ldev was set. */
+                if (mdev->ldev) {
+                        eh = mdev->ldev->dc.on_io_error;
+                        was_io_error = test_and_clear_bit(WAS_IO_ERROR, &mdev->flags);
+
+                        /* Immediately allow completion of all application IO, that waits
+                           for completion from the local disk. */
+                        tl_abort_disk_io(mdev);
+
+                        /* current state still has to be D_FAILED,
+                         * there is only one way out: to D_DISKLESS,
+                         * and that may only happen after our put_ldev below. */
+                        if (mdev->state.disk != D_FAILED)
+                                dev_err(DEV,
+                                        "ASSERT FAILED: disk is %s during detach\n",
+                                        drbd_disk_str(mdev->state.disk));
+
+                        if (ns.conn >= C_CONNECTED)
+                                drbd_send_state(mdev, ns);
+
+                        drbd_rs_cancel_all(mdev);
+
+                        /* In case we want to get something to stable storage still,
+                         * this may be the last chance.
+                         * Following put_ldev may transition to D_DISKLESS. */
+                        drbd_md_sync(mdev);
+                }
                 put_ldev(mdev);
 
                 if (was_io_error && eh == EP_CALL_HELPER)