From 8cc0e50614520c6c609c6ae32a65d0591b7865a1 Mon Sep 17 00:00:00 2001 From: Kent Overstreet Date: Sun, 18 Aug 2024 13:13:39 -0400 Subject: [PATCH] bcachefs: Fix "trying to move an extent, but nr_replicas=0" data_update_init() does a bunch of complicated stuff to decide how many replicas to add, since we only want to increase an extent's durability on an explicit rereplicate, but extent pointers may be on devices with different durability settings. There was a corner case when evacuating a device that had been set to durability=0 after data had been written to it, and extents on that device had already been rereplicated - then evacuate only needs to drop pointers on that device, not move them. So the assert for !m->op.nr_replicas was spurious; this was a perfectly legitimate case that needed to be handled. Signed-off-by: Kent Overstreet --- fs/bcachefs/data_update.c | 29 ++++++++++++----------------- 1 file changed, 12 insertions(+), 17 deletions(-) diff --git a/fs/bcachefs/data_update.c b/fs/bcachefs/data_update.c index 5f49f4953b19..65176d51b502 100644 --- a/fs/bcachefs/data_update.c +++ b/fs/bcachefs/data_update.c @@ -695,16 +695,6 @@ int bch2_data_update_init(struct btree_trans *trans, * Increasing replication is an explicit operation triggered by * rereplicate, currently, so that users don't get an unexpected -ENOSPC */ - if (!(m->data_opts.write_flags & BCH_WRITE_CACHED) && - !durability_required) { - m->data_opts.kill_ptrs |= m->data_opts.rewrite_ptrs; - m->data_opts.rewrite_ptrs = 0; - /* if iter == NULL, it's just a promote */ - if (iter) - ret = bch2_extent_drop_ptrs(trans, iter, k, m->data_opts); - goto out; - } - m->op.nr_replicas = min(durability_removing, durability_required) + m->data_opts.extra_replicas; @@ -716,17 +706,22 @@ int bch2_data_update_init(struct btree_trans *trans, if (!(durability_have + durability_removing)) m->op.nr_replicas = max((unsigned) m->op.nr_replicas, 1); - if (!m->op.nr_replicas) { - struct printbuf buf = PRINTBUF; + m->op.nr_replicas_required = m->op.nr_replicas; - bch2_data_update_to_text(&buf, m); - WARN(1, "trying to move an extent, but nr_replicas=0\n%s", buf.buf); - printbuf_exit(&buf); + /* + * It might turn out that we don't need any new replicas, if the + * replicas or durability settings have been changed since the extent + * was written: + */ + if (!m->op.nr_replicas) { + m->data_opts.kill_ptrs |= m->data_opts.rewrite_ptrs; + m->data_opts.rewrite_ptrs = 0; + /* if iter == NULL, it's just a promote */ + if (iter) + ret = bch2_extent_drop_ptrs(trans, iter, k, m->data_opts); goto out; } - m->op.nr_replicas_required = m->op.nr_replicas; - if (reserve_sectors) { ret = bch2_disk_reservation_add(c, &m->op.res, reserve_sectors, m->data_opts.extra_replicas -- 2.20.1