btrfs: compression: adjust cb->compressed_folios allocation type

[ Upstream commit 6f9a8ab796c6528d22de3c504c81fce7dde63d8a ]

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.

Reviewed-by: Qu Wenruo <[email protected]>
Signed-off-by: Kees Cook <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
(cherry picked from commit 92dff981dddffe6f5f7a4ed53d28623627a3151b)
Signed-off-by: Jack Vogel <[email protected]>

Author: kees

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;