From: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Date: Wed, 9 Jul 2025 19:40:17 +0000 (-0700)
Subject: mm/memory.c: use folios in __access_remote_vm()
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0c092fef53f08f1e461b180c61dddc30491ec855;p=thirdparty%2Flinux.git

mm/memory.c: use folios in __access_remote_vm()

Use kmap_local_folio() instead of kmap_local_page().  Replaces 2 calls to
compound_head() with one.

This prepares us for the removal of unmap_and_put_page().

Link: https://lkml.kernel.org/r/20250709194017.927978-5-vishal.moola@gmail.com
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Jordan Rome <linux@jordanrome.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

diff --git a/mm/memory.c b/mm/memory.c
index cb2f1296854a6..bc27b1990fcba 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -6691,6 +6691,7 @@ static int __access_remote_vm(struct mm_struct *mm, unsigned long addr,
 	while (len) {
 		int bytes, offset;
 		void *maddr;
+		struct folio *folio;
 		struct vm_area_struct *vma = NULL;
 		struct page *page = get_user_page_vma_remote(mm, addr,
 							     gup_flags, &vma);
@@ -6722,21 +6723,22 @@ static int __access_remote_vm(struct mm_struct *mm, unsigned long addr,
 			if (bytes <= 0)
 				break;
 		} else {
+			folio = page_folio(page);
 			bytes = len;
 			offset = addr & (PAGE_SIZE-1);
 			if (bytes > PAGE_SIZE-offset)
 				bytes = PAGE_SIZE-offset;
 
-			maddr = kmap_local_page(page);
+			maddr = kmap_local_folio(folio, folio_page_idx(folio, page) * PAGE_SIZE);
 			if (write) {
 				copy_to_user_page(vma, page, addr,
 						  maddr + offset, buf, bytes);
-				set_page_dirty_lock(page);
+				folio_mark_dirty_lock(folio);
 			} else {
 				copy_from_user_page(vma, page, addr,
 						    buf, maddr + offset, bytes);
 			}
-			unmap_and_put_page(page, maddr);
+			folio_release_kmap(folio, maddr);
 		}
 		len -= bytes;
 		buf += bytes;