On Fri, 17 Feb 2023, Zheng Wang wrote:

Due to the previously fix of __bch_btree_node_alloc, the return value will never be a NULL pointer. So IS_ERR is enough to handle the failure situation. Fix it by replacing IS_ERR_OR_NULL check to IS_ERR check.

Fixes: cafe56359144 ("bcache: A block layer cache") Cc: stable@vger.kernel.org Signed-off-by: Zheng Wang zyytlz.wz@163.com

---

v3:

• Add Cc: stable@vger.kernel.org suggested by Eric

Make sure that the commit bcache: Fix __bch_btree_node_alloc to make the failure behavior consistent is committed _before_ this "Remove some unnecessary NULL point check..." patch.

It would be a good idea to add "this patch depends on `bcache: Fix __bch_btree_node_alloc to make the failure behavior consistent`" to the commit message so the stable maintainers know.

-Eric

v2:

• Replace more checks

---

drivers/md/bcache/btree.c | 10 +++++----- drivers/md/bcache/super.c | 4 ++-- 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c index 147c493a989a..7c21e54468bf 100644 --- a/drivers/md/bcache/btree.c +++ b/drivers/md/bcache/btree.c @@ -1138,7 +1138,7 @@ static struct btree *btree_node_alloc_replacement(struct btree *b, { struct btree *n = bch_btree_node_alloc(b->c, op, b->level, b->parent);

• if (!IS_ERR_OR_NULL(n)) {

• if (!IS_ERR(n)) { mutex_lock(&n->write_lock); bch_btree_sort_into(&b->keys, &n->keys, &b->c->sort); bkey_copy_key(&n->key, &b->key);

@@ -1340,7 +1340,7 @@ static int btree_gc_coalesce(struct btree *b, struct btree_op *op, memset(new_nodes, 0, sizeof(new_nodes)); closure_init_stack(&cl);

• while (nodes < GC_MERGE_NODES && !IS_ERR_OR_NULL(r[nodes].b))

• while (nodes < GC_MERGE_NODES && !IS_ERR(r[nodes].b)) keys += r[nodes++].keys;

blocks = btree_default_blocks(b->c) * 2 / 3; @@ -1352,7 +1352,7 @@ static int btree_gc_coalesce(struct btree *b, struct btree_op *op, for (i = 0; i < nodes; i++) { new_nodes[i] = btree_node_alloc_replacement(r[i].b, NULL);

• if (IS_ERR_OR_NULL(new_nodes[i]))
  

• if (IS_ERR(new_nodes[i]))
  goto out_nocoalesce;
  

  }

@@ -1487,7 +1487,7 @@ static int btree_gc_coalesce(struct btree *b, struct btree_op *op, bch_keylist_free(&keylist); for (i = 0; i < nodes; i++)

• if (!IS_ERR_OR_NULL(new_nodes[i])) {
  

• if (!IS_ERR(new_nodes[i])) {
  btree_node_free(new_nodes[i]);
  rw_unlock(true, new_nodes[i]);
  

  }

@@ -1669,7 +1669,7 @@ static int bch_btree_gc_root(struct btree *b, struct btree_op *op, if (should_rewrite) { n = btree_node_alloc_replacement(b, NULL);

• if (!IS_ERR_OR_NULL(n)) {
  

• if (!IS_ERR(n)) {
  bch_btree_node_write_sync(n);
  

bch_btree_set_root(n); diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c index ba3909bb6bea..7660962e7b8b 100644 --- a/drivers/md/bcache/super.c +++ b/drivers/md/bcache/super.c @@ -1724,7 +1724,7 @@ static void cache_set_flush(struct closure *cl) if (!IS_ERR_OR_NULL(c->gc_thread)) kthread_stop(c->gc_thread);

• if (!IS_ERR_OR_NULL(c->root))

• if (!IS_ERR(c->root)) list_add(&c->root->list, &c->btree_cache);

/* @@ -2088,7 +2088,7 @@ static int run_cache_set(struct cache_set *c) err = "cannot allocate new btree root"; c->root = __bch_btree_node_alloc(c, NULL, 0, true, NULL);

• if (IS_ERR_OR_NULL(c->root))
  

• if (IS_ERR(c->root))
  goto err;
  

mutex_lock(&c->root->write_lock); -- 2.25.1