The patch titled
Subject: mm: convert __do_fault() to use a folio
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
mm-convert-__do_fault-to-use-a-folio.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-convert-__do_fault-to-use-a-folio.patch
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
Subject: mm: convert __do_fault() to use a folio
Date: Wed, 8 Nov 2023 18:28:05 +0000
Convert vmf->page to a folio as soon as we're going to use it. This fixes
a bug if the fault handler returns a tail page with hardware poison; tail
pages have an invalid page->index, so we would fail to unmap the page from
the page tables. We actually have to unmap the entire folio (or
mapping_evict_folio() will fail), so use unmap_mapping_folio() instead.
This also saves various calls to compound_head() hidden in lock_page(),
put_page(), etc.
Link: https://lkml.kernel.org/r/20231108182809.602073-3-willy@xxxxxxxxxxxxx
Fixes: 793917d997df ("mm/readahead: Add large folio readahead")
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Cc: Naoya Horiguchi <naoya.horiguchi@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memory.c | 20 ++++++++++----------
1 file changed, 10 insertions(+), 10 deletions(-)
--- a/mm/memory.c~mm-convert-__do_fault-to-use-a-folio
+++ a/mm/memory.c
@@ -4239,6 +4239,7 @@ oom:
static vm_fault_t __do_fault(struct vm_fault *vmf)
{
struct vm_area_struct *vma = vmf->vma;
+ struct folio *folio;
vm_fault_t ret;
/*
@@ -4267,27 +4268,26 @@ static vm_fault_t __do_fault(struct vm_f
VM_FAULT_DONE_COW)))
return ret;
+ folio = page_folio(vmf->page);
if (unlikely(PageHWPoison(vmf->page))) {
- struct page *page = vmf->page;
vm_fault_t poisonret = VM_FAULT_HWPOISON;
if (ret & VM_FAULT_LOCKED) {
- if (page_mapped(page))
- unmap_mapping_pages(page_mapping(page),
- page->index, 1, false);
- /* Retry if a clean page was removed from the cache. */
- if (invalidate_inode_page(page))
+ if (page_mapped(vmf->page))
+ unmap_mapping_folio(folio);
+ /* Retry if a clean folio was removed from the cache. */
+ if (mapping_evict_folio(folio->mapping, folio))
poisonret = VM_FAULT_NOPAGE;
- unlock_page(page);
+ folio_unlock(folio);
}
- put_page(page);
+ folio_put(folio);
vmf->page = NULL;
return poisonret;
}
if (unlikely(!(ret & VM_FAULT_LOCKED)))
- lock_page(vmf->page);
+ folio_lock(folio);
else
- VM_BUG_ON_PAGE(!PageLocked(vmf->page), vmf->page);
+ VM_BUG_ON_PAGE(!folio_test_locked(folio), vmf->page);
return ret;
}
_
Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are
mm-make-mapping_evict_folio-the-preferred-way-to-evict-clean-folios.patch
mm-convert-__do_fault-to-use-a-folio.patch
mm-use-mapping_evict_folio-in-truncate_error_page.patch
mm-convert-soft_offline_in_use_page-to-use-a-folio.patch
mm-convert-isolate_page-to-mf_isolate_folio.patch
mm-remove-invalidate_inode_page.patch
