mm/codetag: fix arg in pgalloc_tag_copy alloc_tag_sub

alloc_tag_sub() takes bytes as opposed to number of pages as argument.

Currently pgalloc_tag_copy() passes the number of pages.  This fix passes
the correct unit, which is the number of bytes allocated.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: e0a955b ("mm/codetag: add pgalloc_tag_copy()")
Signed-off-by: Sourav Panda <[email protected]>
Acked-by: Suren Baghdasaryan <[email protected]>
Reviewed-by: Pasha Tatashin <[email protected]>
Reviewed-by: Anshuman Khandual <[email protected]>
Cc: Wei Xu <[email protected]>
Cc: Yu Zhao <[email protected]>
Cc: Kent Overstreet <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

Author: Sourav Panda

include/linux/mm.h

@@ -4207,7 +4207,7 @@ static inline void pgalloc_tag_copy(struct folio *new, struct folio *old)
 	/* Clear the old ref to the original allocation tag. */
 	clear_page_tag_ref(&old->page);
 	/* Decrement the counters of the tag on get_new_folio. */
-	alloc_tag_sub(ref, folio_nr_pages(new));
+	alloc_tag_sub(ref, folio_size(new));
 
 	__alloc_tag_ref_set(ref, tag);