[PATCH] dm persistent data: test return value of node_copy

[PATCH] dm persistent data: test return value of node_copy

[Mikulas Patocka]

There were 3 places where the return value of node_copy was not tested.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Assisted-by: Claude:claude-opus-5
Cc: stable@vger.kernel.org
Fixes: 3241b1d3e0aa ("dm: add persistent data library")

---
 drivers/md/persistent-data/dm-btree-remove.c |   13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

Index: linux-2.6/drivers/md/persistent-data/dm-btree-remove.c
===================================================================
--- linux-2.6.orig/drivers/md/persistent-data/dm-btree-remove.c
+++ linux-2.6/drivers/md/persistent-data/dm-btree-remove.c
@@ -253,7 +253,9 @@ static int __rebalance2(struct dm_btree_
 		/*
 		 * Merge
 		 */
-		node_copy(left, right, -nr_right);
+		ret = node_copy(left, right, -nr_right);
+		if (unlikely(ret))
+			return ret;
 		left->header.nr_entries = cpu_to_le32(nr_left + nr_right);
 		delete_at(parent, r->index);
 
@@ -315,13 +317,16 @@ static int delete_center_node(struct dm_
 {
 	uint32_t max_entries = le32_to_cpu(left->header.max_entries);
 	unsigned int shift = min(max_entries - nr_left, nr_center);
+	int ret;
 
 	if (nr_left + shift > max_entries) {
 		DMERR("node shift out of bounds");
 		return -EINVAL;
 	}
 
-	node_copy(left, center, -shift);
+	ret = node_copy(left, center, -shift);
+	if (unlikely(ret))
+		return ret;
 	left->header.nr_entries = cpu_to_le32(nr_left + shift);
 
 	if (shift != nr_center) {
@@ -333,7 +338,9 @@ static int delete_center_node(struct dm_
 		}
 
 		node_shift(right, shift);
-		node_copy(center, right, shift);
+		ret = node_copy(center, right, shift);
+		if (unlikely(ret))
+			return ret;
 		right->header.nr_entries = cpu_to_le32(nr_right + shift);
 	}
 	*key_ptr(parent, r->index) = right->keys[0];

Re: [PATCH] dm persistent data: test return value of node_copy

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 1 potential
issue to consider:
- [Low] dm persistent data: Fixes trailer cites wrong commit for
  node_copy()
--

commit f0758e03fa9ea11bfbf4ab38d82540be653f4f13
Author: Mikulas Patocka <mpatocka@redhat.com>

> dm persistent data: test return value of node_copy
>
> There were 3 places where the return value of node_copy was not tested.
>
> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
> Assisted-by: Claude:claude-opus-5
> Cc: stable@vger.kernel.org
> Fixes: 3241b1d3e0aa ("dm: add persistent data library")

[Severity: Low]
In commit 3241b1d3e0aa ("dm: add persistent data library"), node_copy()
returned void and used BUG_ON() for error checks.  Commit c671ffa55d8b
("dm btree remove: change a bunch of BUG_ON() calls to proper errors")
converted node_copy() to return an error code and left the three call
sites in __rebalance2() and delete_center_node() unchecked.  Should the
Fixes tag be:

  Fixes: c671ffa55d8b ("dm btree remove: change a bunch of BUG_ON() calls to proper errors")

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/db8878fd-43c1-d976-debd-8e1d1547e7c7@redhat.com?part=1