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.
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Fixes: 793917d997df ("mm/readahead: Add large folio readahead")
Cc: stable@xxxxxxxxxxxxxxx
---
mm/memory.c | 20 ++++++++++----------
1 file changed, 10 insertions(+), 10 deletions(-)
diff --git a/mm/memory.c b/mm/memory.c
index 1f18ed4a5497..c2ee303ba6b3 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -4239,6 +4239,7 @@ static vm_fault_t do_anonymous_page(struct vm_fault *vmf)
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_fault *vmf)
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;
}
--
2.42.0
