mm/rmap: use folio_large_nr_pages() in add/remove functions

Let's just use the "large" variant in code where we are sure that we have
a large folio in our hands: this way we are sure that we don't perform any
unnecessary "large" checks.

While at it, convert the VM_BUG_ON_VMA to a VM_WARN_ON_ONCE.

Maybe in the future there will not be a difference in that regard between
large and small folios; in that case, unifying the handling again will be
easy.  E.g., folio_large_nr_pages() will simply translate to
folio_nr_pages() until we replace all instances.

Link: https://lkml.kernel.org/r/20250303163014.1128035-12-david@redhat.com


Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andy Lutomirks^H^Hski <luto@kernel.org>
Cc: Borislav Betkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Lance Yang <ioworker0@gmail.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcow (Oracle) <willy@infradead.org>
Cc: Michal Koutn <mkoutny@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: tejun heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zefan Li <lizefan.x@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>