Re: [PATCH] btrfs: compression: Adjust cb->compressed_folios allocation type

[Qu Wenruo <wqu@suse.com>]

在 2025/4/26 15:53, Kees Cook 写道:
> In preparation for making the kmalloc family of allocators type aware,
> we need to make sure that the returned type from the allocation matches
> the type of the variable being assigned. (Before, the allocator would
> always return "void *", which can be implicitly cast to any pointer type.)
> 
> The assigned type is "struct folio **" but the returned type will be
> "struct page **". These are the same allocation size (pointer size), but
> the types don't match. Adjust the allocation type to match the assignment.
> 
> Signed-off-by: Kees Cook <kees@kernel.org>

Reviewed-by: Qu Wenruo <wqu@suse.com>

Thanks,
Qu

> ---
> Cc: Chris Mason <clm@fb.com>
> Cc: Josef Bacik <josef@toxicpanda.com>
> Cc: David Sterba <dsterba@suse.com>
> Cc: <linux-btrfs@vger.kernel.org>
> ---
>   fs/btrfs/compression.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
> index e7f8ee5d48a4..7f11ef559be6 100644
> --- a/fs/btrfs/compression.c
> +++ b/fs/btrfs/compression.c
> @@ -606,7 +606,7 @@ void btrfs_submit_compressed_read(struct btrfs_bio *bbio)
>   	free_extent_map(em);
>   
>   	cb->nr_folios = DIV_ROUND_UP(compressed_len, PAGE_SIZE);
> -	cb->compressed_folios = kcalloc(cb->nr_folios, sizeof(struct page *), GFP_NOFS);
> +	cb->compressed_folios = kcalloc(cb->nr_folios, sizeof(struct folio *), GFP_NOFS);
>   	if (!cb->compressed_folios) {
>   		ret = BLK_STS_RESOURCE;
>   		goto out_free_bio;