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| author | Kent Overstreet <kent.overstreet@gmail.com> | 2016-05-30 16:05:09 -0800 |
|---|---|---|
| committer | Kent Overstreet <kent.overstreet@gmail.com> | 2016-07-30 01:13:54 -0800 |
| commit | d9ec478c57c165528011840dd8420d4da823dd1a (patch) | |
| tree | 6851b7beefb4455747dc3eb4dfd42c5594e6133a | |
| parent | cd336596ae51c0d56aac0e29a19e9a15b31bd3a7 (diff) | |
bcache: remove sentinel null from btree_iter
| -rw-r--r-- | drivers/md/bcache/btree_iter.c | 23 | ||||
| -rw-r--r-- | drivers/md/bcache/btree_iter.h | 4 |
2 files changed, 13 insertions, 14 deletions
diff --git a/drivers/md/bcache/btree_iter.c b/drivers/md/bcache/btree_iter.c index 0963827efe18..59483bbe57e9 100644 --- a/drivers/md/bcache/btree_iter.c +++ b/drivers/md/bcache/btree_iter.c @@ -514,19 +514,17 @@ static inline void btree_iter_lock_root(struct btree_iter *iter, struct bpos pos { struct cache_set *c = iter->c; - iter->nodes_locked = 0; - iter->nodes_intent_locked = 0; - memset(iter->nodes, 0, sizeof(iter->nodes)); - while (1) { struct btree *b = c->btree_roots[iter->btree_id].b; + unsigned level = READ_ONCE(b->level); - iter->level = b->level; + btree_iter_verify_locking(iter, level); - btree_iter_verify_locking(iter, iter->level); - - if (btree_node_lock(b, iter, iter->level, + if (btree_node_lock(b, iter, level, (b != c->btree_roots[iter->btree_id].b))) { + iter->level = level; + if (level + 1 < BTREE_MAX_DEPTH) + iter->nodes[level + 1] = NULL; btree_iter_node_set(iter, b, pos); break; } @@ -591,7 +589,8 @@ retry: * If we've got a btree node locked (i.e. we aren't about to relock the * root) - advance its node iterator if necessary: */ - if (iter->nodes[iter->level]) { + if (iter->level < BTREE_MAX_DEPTH && + iter->nodes[iter->level]) { struct bkey_s_c k; while ((k = __btree_iter_peek_all(iter)).k && @@ -606,7 +605,8 @@ retry: * btree_iter_lock_root() comes next and that it can't fail */ while (iter->level > l) - if (iter->nodes[iter->level]) { + if (iter->level < BTREE_MAX_DEPTH && + iter->nodes[iter->level]) { struct closure cl; int ret; @@ -672,7 +672,8 @@ struct btree *bch_btree_iter_next_node(struct btree_iter *iter) btree_iter_up(iter); - if (!iter->nodes[iter->level]) + if (iter->level >= BTREE_MAX_DEPTH || + !iter->nodes[iter->level]) return NULL; /* parent node usually won't be locked: redo traversal if necessary */ diff --git a/drivers/md/bcache/btree_iter.h b/drivers/md/bcache/btree_iter.h index c021a2633d2f..c06e692b895e 100644 --- a/drivers/md/bcache/btree_iter.h +++ b/drivers/md/bcache/btree_iter.h @@ -48,10 +48,8 @@ struct btree_iter { * always fail (but since freeing a btree node takes a write lock on the * node, which increments the node's lock seq, that's not actually * necessary in that example). - * - * One extra slot for a sentinel NULL: */ - struct btree *nodes[BTREE_MAX_DEPTH + 1]; + struct btree *nodes[BTREE_MAX_DEPTH]; struct btree_node_iter node_iters[BTREE_MAX_DEPTH]; /* |