From: Kent Overstreet <kent.overstreet@gmail.com>
Date: Wed, 14 Apr 2021 17:29:34 +0000 (-0400)
Subject: bcachefs: Better iterator picking
X-Git-Tag: io_uring-6.7-2023-11-10~119^2~1647
X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=a0c9cc1727ecf302ab0be07e93d0c023e64be8da;p=linux-block.git

bcachefs: Better iterator picking

Avoid cloning iterators if we don't have to.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
---

diff --git a/fs/bcachefs/btree_iter.c b/fs/bcachefs/btree_iter.c
index 033a079fb3f3..7d8b7d765cf7 100644
--- a/fs/bcachefs/btree_iter.c
+++ b/fs/bcachefs/btree_iter.c
@@ -2017,10 +2017,14 @@ struct btree_iter *__bch2_trans_get_iter(struct btree_trans *trans,
 		if (iter->btree_id != btree_id)
 			continue;
 
-		if (best &&
-		    bkey_cmp(bpos_diff(best->real_pos, pos),
-			     bpos_diff(iter->real_pos, pos)) < 0)
-			continue;
+		if (best) {
+			int cmp = bkey_cmp(bpos_diff(best->real_pos, pos),
+					   bpos_diff(iter->real_pos, pos));
+
+			if (cmp < 0 ||
+			    ((cmp == 0 && btree_iter_keep(trans, iter))))
+				continue;
+		}
 
 		best = iter;
 	}