Commit 468035ca authored by Kent Overstreet's avatar Kent Overstreet
Browse files

bcachefs: Start gc, copygc, rebalance threads after initing writes ref 



This fixes a bug where copygc would occasionally race with going
read-write and die, thinking we were read only, because it couldn't take
a ref on c->writes.

It's not necessary for copygc (or rebalance, or copygc) to take write
refs; they could run with BCH_TRANS_COMMIT_nocheck_rw, but this is an
easier fix that making sure that flag is passed correctly everywhere.

Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
parent 202a7c29

fs/bcachefs/super.c

+16 −12
Original line number Diff line number Diff line
@@ -423,6 +423,18 @@ static int __bch2_fs_read_write(struct bch_fs *c, bool early) 
		bch2_dev_allocator_add(c, ca);

	bch2_recalc_capacity(c);



	set_bit(BCH_FS_RW, &c->flags);

	set_bit(BCH_FS_WAS_RW, &c->flags);



#ifndef BCH_WRITE_REF_DEBUG

	percpu_ref_reinit(&c->writes);

#else

	for (i = 0; i < BCH_WRITE_REF_NR; i++) {

		BUG_ON(atomic_long_read(&c->writes[i]));

		atomic_long_inc(&c->writes[i]);

	}

#endif



	ret = bch2_gc_thread_start(c);

	if (ret) {

		bch_err(c, "error starting gc thread");
@@ -439,23 +451,15 @@ static int __bch2_fs_read_write(struct bch_fs *c, bool early) 
			goto err;

	}



#ifndef BCH_WRITE_REF_DEBUG

	percpu_ref_reinit(&c->writes);

#else

	for (i = 0; i < BCH_WRITE_REF_NR; i++) {

		BUG_ON(atomic_long_read(&c->writes[i]));

		atomic_long_inc(&c->writes[i]);

	}

#endif

	set_bit(BCH_FS_RW, &c->flags);

	set_bit(BCH_FS_WAS_RW, &c->flags);



	bch2_do_discards(c);

	bch2_do_invalidates(c);

	bch2_do_stripe_deletes(c);

	bch2_do_pending_node_rewrites(c);

	return 0;

err:

	if (test_bit(BCH_FS_RW, &c->flags))

		bch2_fs_read_only(c);

	else

		__bch2_fs_read_only(c);

	return ret;

}