Commit 0c092fef authored by Vishal Moola (Oracle)'s avatar Vishal Moola (Oracle) Committed by Andrew Morton
Browse files

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: default avatarVishal Moola (Oracle) <vishal.moola@gmail.com>
Acked-by: default avatarDavid Hildenbrand <david@redhat.com>
Cc: Jordan Rome <linux@jordanrome.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 0ec5eea2

mm/memory.c

+5 −3
Original line number Diff line number Diff line
@@ -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;