From: Kent Overstreet Date: Wed, 29 Nov 2023 00:26:23 +0000 (-0500) Subject: bcachefs: Fix race between btree writes and metadata drop X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=2111f39459b0b2ec54859b756c625edb0befce0e;p=linux.git bcachefs: Fix race between btree writes and metadata drop btree writes update the btree node key after every write, in order to update sectors_written, and they also might need to drop pointers if one of the writes failed in a replicated btree node. But the btree node might also have had a pointer dropped while the write was in flight, by bch2_dev_metadata_drop(), and thus there was a bug where the btree node write would ovewrite the btree node's key with what it had at the start of the write. Fix this by dropping pointers not currently in the btree node key. Signed-off-by: Kent Overstreet --- diff --git a/fs/bcachefs/btree_update_interior.c b/fs/bcachefs/btree_update_interior.c index d68fb01944b14..6697417273aa1 100644 --- a/fs/bcachefs/btree_update_interior.c +++ b/fs/bcachefs/btree_update_interior.c @@ -2270,6 +2270,10 @@ int bch2_btree_node_update_key_get_iter(struct btree_trans *trans, BUG_ON(!btree_node_hashed(b)); + struct bch_extent_ptr *ptr; + bch2_bkey_drop_ptrs(bkey_i_to_s(new_key), ptr, + !bch2_bkey_has_device(bkey_i_to_s(&b->key), ptr->dev)); + ret = bch2_btree_node_update_key(trans, &iter, b, new_key, commit_flags, skip_triggers); out: