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@xxxxxxxxxxxxxxx
> Signed-off-by: Zheng Wang <zyytlz.wz@xxxxxxx>
> ---
> v3:
> - Add Cc: stable@xxxxxxxxxxxxxxx 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
>
>
