From: Kent Overstreet <kent.overstreet@gmail.com>
Date: Fri, 16 Oct 2020 02:50:48 +0000 (-0400)
Subject: bcachefs: Fix copygc dying on startup
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=9f20ed157d521c7a1af0fe01e80d9e0ee880f9f7;p=linux.git

bcachefs: Fix copygc dying on startup

The copygc threads errors out and makes the filesystem go RO if it ever
tries to run and discovers it has no reserve allocated - which is a
problem if it races with the allocator thread and its reserve hasn't
been filled yet.

The allocator thread doesn't start filling the copygc reserve until
after BCH_FS_STARTED has been set, so make sure to wake up the allocator
threads after setting that and before starting copygc.

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

diff --git a/fs/bcachefs/alloc_background.h b/fs/bcachefs/alloc_background.h
index f6b9f27f07134..4f462696b747a 100644
--- a/fs/bcachefs/alloc_background.h
+++ b/fs/bcachefs/alloc_background.h
@@ -61,8 +61,10 @@ static inline void bch2_wake_allocator(struct bch_dev *ca)
 
 	rcu_read_lock();
 	p = rcu_dereference(ca->alloc_thread);
-	if (p)
+	if (p) {
 		wake_up_process(p);
+		ca->allocator_state = ALLOCATOR_RUNNING;
+	}
 	rcu_read_unlock();
 }
 
diff --git a/fs/bcachefs/super.c b/fs/bcachefs/super.c
index 988c678de9fc6..85ba96cb2292e 100644
--- a/fs/bcachefs/super.c
+++ b/fs/bcachefs/super.c
@@ -888,6 +888,13 @@ int bch2_fs_start(struct bch_fs *c)
 
 	set_bit(BCH_FS_STARTED, &c->flags);
 
+	/*
+	 * Allocator threads don't start filling copygc reserve until after we
+	 * set BCH_FS_STARTED - wake them now:
+	 */
+	for_each_online_member(ca, c, i)
+		bch2_wake_allocator(ca);
+
 	if (c->opts.read_only || c->opts.nochanges) {
 		bch2_fs_read_only(c);
 	} else {