[Devel] [PATCH vz9 v1 60/63] dm-ploop: dm-ploop: simplify discard completion

[Alexander Atanasov]

ploop_advance_local_after_bat_wb is handling only one
md page, so it is possible do simplify discard completion
done in ploop_piwb_discard_completed.
initialization overlaps and there is an extra md page
lookup which can be avoided.

remove the function and integrate it into
ploop_advance_local_after_bat_wb.

This also makes locking more obvious.

https://virtuozzo.atlassian.net/browse/VSTOR-98392
Signed-off-by: Alexander Atanasov <alexander.atanasov at virtuozzo.com>
---
 drivers/md/dm-ploop-map.c | 45 ++++++++++++---------------------------
 1 file changed, 14 insertions(+), 31 deletions(-)

diff --git a/drivers/md/dm-ploop-map.c b/drivers/md/dm-ploop-map.c
index 98297fb46bb6..ef0a7e10d1cc 100644
--- a/drivers/md/dm-ploop-map.c
+++ b/drivers/md/dm-ploop-map.c
@@ -798,36 +798,6 @@ static void ploop_complete_cow(struct ploop_cow *cow, blk_status_t bi_status)
 	kmem_cache_free(cow_cache, cow);
 }
 
-static void ploop_piwb_discard_completed(struct ploop *ploop,
-					 bool success, u32 clu, u32 new_dst_clu)
-{
-	u32 id, *bat_entries, dst_clu;
-	struct md_page *md;
-	u8 level;
-
-	if (new_dst_clu)
-		return;
-
-	id = ploop_bat_clu_to_page_nr(clu);
-	md = ploop_md_page_find(ploop, id);
-	BUG_ON(!md);
-
-	clu = ploop_bat_clu_idx_in_page(clu); /* relative to page */
-
-	bat_entries = md->kmpage;
-	dst_clu = READ_ONCE(bat_entries[clu]);
-	level = md->bat_levels[clu];
-
-	if (!(dst_clu == BAT_ENTRY_NONE || level < ploop_top_level(ploop))) {
-		WARN_ON_ONCE(ploop->nr_deltas != 1);
-		if (success) {
-			WRITE_ONCE(bat_entries[clu], BAT_ENTRY_NONE);
-			WRITE_ONCE(md->bat_levels[clu], 0);
-			ploop_hole_set_bit(dst_clu, ploop);
-		}
-	}
-}
-
 /*
  * Update local BAT copy with written indexes on success.
  * Mark allocate clusters as holes on failure.
@@ -872,7 +842,20 @@ static void ploop_advance_local_after_bat_wb(struct ploop *ploop,
 #endif
 	for (; i < last; i++) {
 		if (piwb->type == PIWB_TYPE_DISCARD) {
-			ploop_piwb_discard_completed(ploop, success, i + off, dst_clu[i]);
+			/* discard completed */
+			u32 clu = i + off;
+			u8 level = md->bat_levels[clu];
+			u32 d_clu = READ_ONCE(bat_entries[clu]);
+
+			if (success && !dst_clu[i] &&
+			    (!(d_clu == BAT_ENTRY_NONE ||
+			    level < ploop_top_level(ploop)))) {
+				WARN_ON_ONCE(ploop->nr_deltas != 1);
+				WRITE_ONCE(bat_entries[clu], BAT_ENTRY_NONE);
+				WRITE_ONCE(md->bat_levels[clu], 0);
+				ploop_hole_set_bit(d_clu, ploop);
+			}
+
 			continue;
 		}
 
-- 
2.43.0