Commit 0ec5eea2 authored by Vishal Moola (Oracle)'s avatar Vishal Moola (Oracle) Committed by Andrew Morton
Browse files

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

Patch series "Remove unmap_and_put_page()".

This patchset uses folios in both the callers of unmap_and_put_page(),
saving a couple calls to compound_head() wrappers.


This patch (of 3):

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

This prepares us for the removal of unmap_and_put_page().

Link: https://lkml.kernel.org/r/20250709194017.927978-3-vishal.moola@gmail.com
Link: https://lkml.kernel.org/r/20250709194017.927978-4-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 db87a4e2

mm/memory.c

+5 −3
Original line number Diff line number Diff line
@@ -6815,6 +6815,7 @@ static int __copy_remote_vm_str(struct mm_struct *mm, unsigned long addr, 
	while (len) {

		int bytes, offset, retval;

		void *maddr;

		struct folio *folio;

		struct page *page;

		struct vm_area_struct *vma = NULL;
@@ -6830,17 +6831,18 @@ static int __copy_remote_vm_str(struct mm_struct *mm, unsigned long addr, 
			goto out;

		}



		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);

		retval = strscpy(buf, maddr + offset, bytes);

		if (retval >= 0) {

			/* Found the end of the string */

			buf += retval;

			unmap_and_put_page(page, maddr);

			folio_release_kmap(folio, maddr);

			break;

		}
@@ -6858,7 +6860,7 @@ static int __copy_remote_vm_str(struct mm_struct *mm, unsigned long addr, 
		}

		len -= bytes;



		unmap_and_put_page(page, maddr);

		folio_release_kmap(folio, maddr);

	}



out: