Re: [RFC PATCH 17/17] netfs: Combine prepare and issue ops and grab the buffers on request

From: ChenXiaoSong

Date: Mon Mar 23 2026 - 21:04:46 EST


In netfs_writeback_single(), on the failure path, should we call netfs_put_failed_request() instead of netfs_put_request()?

```
--- a/fs/netfs/write_issue.c
+++ b/fs/netfs/write_issue.c
@@ -1041,7 +1041,7 @@ int netfs_writeback_single(struct address_space *mapping,
return ret;

cleanup_free:
- netfs_put_request(wreq, netfs_rreq_trace_put_return);
+ netfs_put_failed_request(wreq, netfs_rreq_trace_put_return);
couldnt_start:
mutex_unlock(&ictx->wb_lock);
_leave(" = %d", ret);
```

Thanks,
ChenXiaoSong <chenxiaosong@xxxxxxxxxx>

On 3/24/26 06:44, Paulo Alcantara wrote:
Thanks for the review. The above is still broken as it wolud cause an
UAF on @subreq as we're putting it with netfs_put_subrequest() and then
dereferencing it afterwards.

Besides, we could also get rid of 'subreq = NULL' as it is currently a
no-op -- including in other places.

Let's wait for next patchset from Dave, though.