Commit bc9389ee authored by Kent Overstreet's avatar Kent Overstreet

bcache: Avoid deadlocking in garbage collection

Not a complete fix - we could still deadlock if btree_insert_node() has
to split...
Signed-off-by: default avatarKent Overstreet <kmo@daterainc.com>
parent a1f0358b
......@@ -1059,14 +1059,14 @@ static void btree_node_free(struct btree *b)
mutex_unlock(&b->c->bucket_lock);
}
struct btree *bch_btree_node_alloc(struct cache_set *c, int level)
struct btree *bch_btree_node_alloc(struct cache_set *c, int level, bool wait)
{
BKEY_PADDED(key) k;
struct btree *b = ERR_PTR(-EAGAIN);
mutex_lock(&c->bucket_lock);
retry:
if (__bch_bucket_alloc_set(c, WATERMARK_METADATA, &k.key, 1, true))
if (__bch_bucket_alloc_set(c, WATERMARK_METADATA, &k.key, 1, wait))
goto err;
bkey_put(c, &k.key);
......@@ -1098,9 +1098,9 @@ struct btree *bch_btree_node_alloc(struct cache_set *c, int level)
return b;
}
static struct btree *btree_node_alloc_replacement(struct btree *b)
static struct btree *btree_node_alloc_replacement(struct btree *b, bool wait)
{
struct btree *n = bch_btree_node_alloc(b->c, b->level);
struct btree *n = bch_btree_node_alloc(b->c, b->level, wait);
if (!IS_ERR_OR_NULL(n))
bch_btree_sort_into(b, n);
......@@ -1250,7 +1250,7 @@ static int btree_gc_coalesce(struct btree *b, struct btree_op *op,
return 0;
for (i = 0; i < nodes; i++) {
new_nodes[i] = btree_node_alloc_replacement(r[i].b);
new_nodes[i] = btree_node_alloc_replacement(r[i].b, false);
if (IS_ERR_OR_NULL(new_nodes[i]))
goto out_nocoalesce;
}
......@@ -1420,7 +1420,8 @@ static int btree_gc_recurse(struct btree *b, struct btree_op *op,
if (!IS_ERR(last->b)) {
should_rewrite = btree_gc_mark_node(last->b, gc);
if (should_rewrite) {
n = btree_node_alloc_replacement(last->b);
n = btree_node_alloc_replacement(last->b,
false);
if (!IS_ERR_OR_NULL(n)) {
bch_btree_node_write_sync(n);
......@@ -1492,7 +1493,7 @@ static int bch_btree_gc_root(struct btree *b, struct btree_op *op,
should_rewrite = btree_gc_mark_node(b, gc);
if (should_rewrite) {
n = btree_node_alloc_replacement(b);
n = btree_node_alloc_replacement(b, false);
if (!IS_ERR_OR_NULL(n)) {
bch_btree_node_write_sync(n);
......@@ -2038,7 +2039,7 @@ static int btree_split(struct btree *b, struct btree_op *op,
closure_init_stack(&cl);
n1 = btree_node_alloc_replacement(b);
n1 = btree_node_alloc_replacement(b, true);
if (IS_ERR(n1))
goto err;
......@@ -2049,12 +2050,12 @@ static int btree_split(struct btree *b, struct btree_op *op,
trace_bcache_btree_node_split(b, n1->sets[0].data->keys);
n2 = bch_btree_node_alloc(b->c, b->level);
n2 = bch_btree_node_alloc(b->c, b->level, true);
if (IS_ERR(n2))
goto err_free1;
if (!b->parent) {
n3 = bch_btree_node_alloc(b->c, b->level + 1);
n3 = bch_btree_node_alloc(b->c, b->level + 1, true);
if (IS_ERR(n3))
goto err_free2;
}
......
......@@ -271,7 +271,7 @@ void bch_btree_node_read(struct btree *);
void bch_btree_node_write(struct btree *, struct closure *);
void bch_btree_set_root(struct btree *);
struct btree *bch_btree_node_alloc(struct cache_set *, int);
struct btree *bch_btree_node_alloc(struct cache_set *, int, bool);
struct btree *bch_btree_node_get(struct cache_set *, struct bkey *, int, bool);
int bch_btree_insert_check_key(struct btree *, struct btree_op *,
......
......@@ -1601,7 +1601,7 @@ static void run_cache_set(struct cache_set *c)
goto err;
err = "cannot allocate new btree root";
c->root = bch_btree_node_alloc(c, 0);
c->root = bch_btree_node_alloc(c, 0, true);
if (IS_ERR_OR_NULL(c->root))
goto err;
......
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