drbd: get rid of atomic update on disk bitmap works

Just trigger the occasional lazy bitmap write-out during resync
from the central wait_for_work() helper.

Previously, during resync, bitmap pages would be written out separately,
synchronously, one at a time, at least 8 times each (every 512 bytes
worth of bitmap cleared).

Now we trigger "merge friendly" bulk write out of all cleared pages
every two seconds during resync, and once the resync is finished.
Most pages will be written out only once.

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

1 files changed, 1 insertions, 62 deletions

diff --git a/drivers/block/drbd/drbd_actlog.c b/drivers/block/drbd/drbd_actlog.c
index 05a1780ffa85..9c42edf4871b 100644
--- a/drivers/block/drbd/drbd_actlog.c
+++ b/drivers/block/drbd/drbd_actlog.c
@@ -92,12 +92,6 @@ struct __packed al_transaction_on_disk {
 	__be32	context[AL_CONTEXT_PER_TRANSACTION];
 };
 
-struct update_odbm_work {
-	struct drbd_work w;
-	struct drbd_device *device;
-	unsigned int enr;
-};
-
 struct update_al_work {
 	struct drbd_work w;
 	struct drbd_device *device;
@@ -452,15 +446,6 @@ static unsigned int al_extent_to_bm_page(unsigned int al_enr)
 		 (AL_EXTENT_SHIFT - BM_BLOCK_SHIFT));
 }
 
-static unsigned int rs_extent_to_bm_page(unsigned int rs_enr)
-{
-	return rs_enr >>
-		/* bit to page */
-		((PAGE_SHIFT + 3) -
-		/* resync extent number to bit */
-		 (BM_EXT_SHIFT - BM_BLOCK_SHIFT));
-}
-
 static sector_t al_tr_number_to_on_disk_sector(struct drbd_device *device)
 {
 	const unsigned int stripes = device->ldev->md.al_stripes;
@@ -682,40 +667,6 @@ int drbd_initialize_al(struct drbd_device *device, void *buffer)
 	return 0;
 }
 
-static int w_update_odbm(struct drbd_work *w, int unused)
-{
-	struct update_odbm_work *udw = container_of(w, struct update_odbm_work, w);
-	struct drbd_device *device = udw->device;
-	struct sib_info sib = { .sib_reason = SIB_SYNC_PROGRESS, };
-
-	if (!get_ldev(device)) {
-		if (__ratelimit(&drbd_ratelimit_state))
-			drbd_warn(device, "Can not update on disk bitmap, local IO disabled.\n");
-		kfree(udw);
-		return 0;
-	}
-
-	drbd_bm_write_page(device, rs_extent_to_bm_page(udw->enr));
-	put_ldev(device);
-
-	kfree(udw);
-
-	if (drbd_bm_total_weight(device) <= device->rs_failed) {
-		switch (device->state.conn) {
-		case C_SYNC_SOURCE:  case C_SYNC_TARGET:
-		case C_PAUSED_SYNC_S: case C_PAUSED_SYNC_T:
-			drbd_resync_finished(device);
-		default:
-			/* nothing to do */
-			break;
-		}
-	}
-	drbd_bcast_event(device, &sib);
-
-	return 0;
-}
-
-
 /* ATTENTION. The AL's extents are 4MB each, while the extents in the
  * resync LRU-cache are 16MB each.
  * The caller of this function has to hold an get_ldev() reference.
@@ -726,8 +677,6 @@ static void drbd_try_clear_on_disk_bm(struct drbd_device *device, sector_t secto
 				      int count, int success)
 {
 	struct lc_element *e;
-	struct update_odbm_work *udw;
-
 	unsigned int enr;
 
 	D_ASSERT(device, atomic_read(&device->local_cnt));
@@ -791,17 +740,7 @@ static void drbd_try_clear_on_disk_bm(struct drbd_device *device, sector_t secto
 
 		if (ext->rs_left == ext->rs_failed) {
 			ext->rs_failed = 0;
-
-			udw = kmalloc(sizeof(*udw), GFP_ATOMIC);
-			if (udw) {
-				udw->enr = ext->lce.lc_number;
-				udw->w.cb = w_update_odbm;
-				udw->device = device;
-				drbd_queue_work_front(&first_peer_device(device)->connection->sender_work,
-						      &udw->w);
-			} else {
-				drbd_warn(device, "Could not kmalloc an udw\n");
-			}
+			wake_up(&first_peer_device(device)->connection->sender_work.q_wait);
 		}
 	} else {
 		drbd_err(device, "lc_get() failed! locked=%d/%d flags=%lu\n",