From bf0a628a95dba7f983b6047cea695fb066fb2512 Mon Sep 17 00:00:00 2001 From: Nicholas Swenson Date: Tue, 26 Nov 2013 19:14:23 -0800 Subject: [PATCH] bcache: fix for gc and writeback race Garbage collector needs to check keys in the writeback keybuf to make sure it's not invalidating buckets to which the writeback keys point to. Signed-off-by: Nicholas Swenson Signed-off-by: Kent Overstreet --- drivers/md/bcache/btree.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c index c36745e5986a..31bb53fcc67a 100644 --- a/drivers/md/bcache/btree.c +++ b/drivers/md/bcache/btree.c @@ -1561,6 +1561,28 @@ size_t bch_btree_gc_finish(struct cache_set *c) SET_GC_MARK(PTR_BUCKET(c, &c->uuid_bucket, i), GC_MARK_METADATA); + /* don't reclaim buckets to which writeback keys point */ + rcu_read_lock(); + for (i = 0; i < c->nr_uuids; i++) { + struct bcache_device *d = c->devices[i]; + struct cached_dev *dc; + struct keybuf_key *w, *n; + unsigned j; + + if (!d || UUID_FLASH_ONLY(&c->uuids[i])) + continue; + dc = container_of(d, struct cached_dev, disk); + + spin_lock(&dc->writeback_keys.lock); + rbtree_postorder_for_each_entry_safe(w, n, + &dc->writeback_keys.keys, node) + for (j = 0; j < KEY_PTRS(&w->key); j++) + SET_GC_MARK(PTR_BUCKET(c, &w->key, j), + GC_MARK_DIRTY); + spin_unlock(&dc->writeback_keys.lock); + } + rcu_read_unlock(); + for_each_cache(ca, c, i) { uint64_t *i; -- 2.20.1