[PATCH v2 03/15] bcachefs: Improve check_allocations pass speed when not in fsck

[Nikita Ofitserov via B4 Relay <devnull+himikof.gmail.com@kernel.org>]

From: Nikita Ofitserov <himikof@gmail.com>

Skip reading unnecessary leaf btree nodes unless running fsck.
For example, this should speed up version upgrade/downgrade when
rebuilding accounting information.

Signed-off-by: Nikita Ofitserov <himikof@gmail.com>
---
 fs/bcachefs/btree_gc.c | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/fs/bcachefs/btree_gc.c b/fs/bcachefs/btree_gc.c
index 2a369aebdbe216ed665115e27388ab4821696bf8..b95a3610900de2eecf978c62f3809453455f7a5c 100644
--- a/fs/bcachefs/btree_gc.c
+++ b/fs/bcachefs/btree_gc.c
@@ -793,8 +793,21 @@ static int bch2_gc_btrees(struct bch_fs *c)
 		if (IS_ERR_OR_NULL(bch2_btree_id_root(c, btree)->b))
 			continue;
 
-		/* We need to make sure every leaf node is readable before going RW */
-		ret = bch2_gc_btree(trans, &progress, btree, 0, true);
+
+		unsigned target_depth = BIT_ULL(btree) & btree_leaf_has_triggers_mask ? 0 : 1;
+
+		/*
+		 * In fsck, we need to make sure every leaf node is readable
+		 * before going RW, otherwise we can no longer rewind inside
+		 * btree_lost_data to repair during the current fsck run.
+		 *
+		 * Otherwise, we can delay the repair to the next
+		 * mount or offline fsck.
+		 */
+		if (test_bit(BCH_FS_in_fsck, &c->flags))
+			target_depth = 0;
+
+		ret = bch2_gc_btree(trans, &progress, btree, target_depth, true);
 	}
 
 	bch_err_fn(c, ret);

-- 
2.50.1