[Devel] [RFC PATCH vz9 v6 60/62] dm-ploop: sync when suspended or stopping

[Alexander Atanasov]

On suspended or stopped sync delta.

https://virtuozzo.atlassian.net/browse/VSTOR-91821
Signed-off-by: Alexander Atanasov <alexander.atanasov at virtuozzo.com>
---
 drivers/md/dm-ploop-target.c | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/drivers/md/dm-ploop-target.c b/drivers/md/dm-ploop-target.c
index 66a0d4655fd1..4e5800657bf6 100644
--- a/drivers/md/dm-ploop-target.c
+++ b/drivers/md/dm-ploop-target.c
@@ -61,7 +61,8 @@ void ploop_call_rw_iter(struct file *file, loff_t pos, unsigned rw,
 	init_sync_kiocb(iocb, file);
 	iocb->ki_pos = pos;
 	iocb->ki_complete = ploop_aio_complete;
-	if (pio->bi_op & REQ_FUA)
+	iocb->ki_flags |= IOCB_ALLOC_CACHE;
+	if (rw == WRITE && pio->bi_op & REQ_FUA)
 		iocb->ki_flags |= IOCB_DSYNC;
 
 	atomic_set(&pio->aio_ref, 2);
@@ -193,7 +194,8 @@ static void ploop_destroy(struct ploop *ploop)
 			}
 		}
 
-		kthread_stop(ploop->kt_worker->task);	/* waits for the thread to stop */
+		/* waits for the thread to stop */
+		kthread_stop(ploop->kt_worker->task);
 
 		WARN_ON(!llist_empty(&ploop->pios[PLOOP_LIST_PREPARE]));
 		WARN_ON(!llist_empty(&ploop->llresubmit_pios));
@@ -207,6 +209,8 @@ static void ploop_destroy(struct ploop *ploop)
 		percpu_ref_exit(&ploop->inflight_bios_ref[i]);
 	/* Nobody uses it after destroy_workqueue() */
 	while (ploop->nr_deltas-- > 0) {
+		vfs_fsync(ploop->deltas[ploop->nr_deltas].file, 1);
+
 		if (ploop->deltas[ploop->nr_deltas].file)
 			fput(ploop->deltas[ploop->nr_deltas].file);
 		for (i = 0; i < ploop->nkt_runners; i++) {
@@ -286,10 +290,15 @@ static int ploop_check_top_delta(struct ploop *ploop, struct file *file)
 	if (!page)
 		goto out;
 
+
 	ret = ploop_rw_page_sync(READ, file, 0, page);
 	if (ret < 0)
 		goto out;
 
+
+	/* flush dirty pages before changing direct IO */
+	vfs_fsync(file, 1);
+
 	ret = ploop_setup_metadata(ploop, page);
 	if (ret)
 		goto out;
@@ -351,6 +360,9 @@ static int ploop_add_deltas_stack(struct ploop *ploop, char **argv, int argc)
 				goto err_fput;
 		}
 
+		/* switch to direct io here */
+		vfs_fsync(file, 0);
+
 		ret = ploop_add_delta(ploop, i, file, is_raw);
 		if (ret < 0)
 			goto err_fput;
@@ -671,11 +683,16 @@ static void ploop_presuspend(struct dm_target *ti)
 	 * For pending enospc requests. Otherwise,
 	 * we may never be able to suspend this target.
 	 */
+	/* All flushes are done as one */
 	ploop_set_wants_suspend(ti, true);
 	flush_work(&ploop->event_work);
 	del_timer_sync(&ploop->enospc_timer);
+	wait_event_interruptible(ploop->dispatcher_wq_data,
+			(!atomic_read(&ploop->kt_worker->inflight_pios)));
+	vfs_fsync(ploop_top_delta(ploop)->file, 0);
 	ploop_enospc_timer(&ploop->enospc_timer);
 }
+
 static void ploop_presuspend_undo(struct dm_target *ti)
 {
 	ploop_set_wants_suspend(ti, false);
-- 
2.43.0