[v3] bcache: Remove some unnecessary NULL point check for the return value of __bch_btree_node_alloc-related pointer

[RESEBD PATCH v3] bcache: Remove some unnecessary NULL point check for the return value of __bch_btree_node_alloc-related pointer

Posted by Zheng Wang 2 years, 6 months ago

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
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

Re: [RESEBD PATCH v3] bcache: Remove some unnecessary NULL point check for the return value of __bch_btree_node_alloc-related pointer

Posted by Eric Wheeler 2 years, 6 months ago

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
> 
>

Re: [RESEBD PATCH v3] bcache: Remove some unnecessary NULL point check for the return value of __bch_btree_node_alloc-related pointer

Posted by Zheng Hacker 2 years, 6 months ago

Eric Wheeler <bcache@lists.ewheeler.net> 于2023年2月18日周六 05:57写道：
>
> 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.

Oh, sorry for my mistake. I forgot to commit the first patch. I'll try
to commit it first.

>
> 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.

Yes, I will append that msg in the next version.

Best regargds,
Zheng