swap: convert add_to_swap() to take a folio

The only caller already has a folio available, so this saves a conversion.
Also convert the return type to boolean.

Link: https://lkml.kernel.org/r/20220504182857.4013401-9-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Matthew Wilcox (Oracle) 2022-05-12 20:23:02 -07:00 committed by Andrew Morton
parent e2e3fdc7d4
commit 09c02e5632
3 changed files with 31 additions and 28 deletions

View File

@ -32,7 +32,7 @@ extern struct address_space *swapper_spaces[];
>> SWAP_ADDRESS_SPACE_SHIFT])
void show_swap_cache_info(void);
int add_to_swap(struct page *page);
bool add_to_swap(struct folio *folio);
void *get_shadow_from_swap_cache(swp_entry_t entry);
int add_to_swap_cache(struct page *page, swp_entry_t entry,
gfp_t gfp, void **shadowp);
@ -119,9 +119,9 @@ struct page *find_get_incore_page(struct address_space *mapping, pgoff_t index)
return find_get_page(mapping, index);
}
static inline int add_to_swap(struct page *page)
static inline bool add_to_swap(struct folio *folio)
{
return 0;
return false;
}
static inline void *get_shadow_from_swap_cache(swp_entry_t entry)

View File

@ -176,24 +176,26 @@ void __delete_from_swap_cache(struct page *page,
}
/**
* add_to_swap - allocate swap space for a page
* @page: page we want to move to swap
* add_to_swap - allocate swap space for a folio
* @folio: folio we want to move to swap
*
* Allocate swap space for the page and add the page to the
* swap cache. Caller needs to hold the page lock.
* Allocate swap space for the folio and add the folio to the
* swap cache.
*
* Context: Caller needs to hold the folio lock.
* Return: Whether the folio was added to the swap cache.
*/
int add_to_swap(struct page *page)
bool add_to_swap(struct folio *folio)
{
struct folio *folio = page_folio(page);
swp_entry_t entry;
int err;
VM_BUG_ON_PAGE(!PageLocked(page), page);
VM_BUG_ON_PAGE(!PageUptodate(page), page);
VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio);
VM_BUG_ON_FOLIO(!folio_test_uptodate(folio), folio);
entry = folio_alloc_swap(folio);
if (!entry.val)
return 0;
return false;
/*
* XArray node allocations from PF_MEMALLOC contexts could
@ -206,7 +208,7 @@ int add_to_swap(struct page *page)
/*
* Add it to the swap cache.
*/
err = add_to_swap_cache(page, entry,
err = add_to_swap_cache(&folio->page, entry,
__GFP_HIGH|__GFP_NOMEMALLOC|__GFP_NOWARN, NULL);
if (err)
/*
@ -215,22 +217,23 @@ int add_to_swap(struct page *page)
*/
goto fail;
/*
* Normally the page will be dirtied in unmap because its pte should be
* dirty. A special case is MADV_FREE page. The page's pte could have
* dirty bit cleared but the page's SwapBacked bit is still set because
* clearing the dirty bit and SwapBacked bit has no lock protected. For
* such page, unmap will not set dirty bit for it, so page reclaim will
* not write the page out. This can cause data corruption when the page
* is swap in later. Always setting the dirty bit for the page solves
* the problem.
* Normally the folio will be dirtied in unmap because its
* pte should be dirty. A special case is MADV_FREE page. The
* page's pte could have dirty bit cleared but the folio's
* SwapBacked flag is still set because clearing the dirty bit
* and SwapBacked flag has no lock protected. For such folio,
* unmap will not set dirty bit for it, so folio reclaim will
* not write the folio out. This can cause data corruption when
* the folio is swapped in later. Always setting the dirty flag
* for the folio solves the problem.
*/
set_page_dirty(page);
folio_mark_dirty(folio);
return 1;
return true;
fail:
put_swap_page(page, entry);
return 0;
put_swap_page(&folio->page, entry);
return false;
}
/*

View File

@ -1731,8 +1731,8 @@ static unsigned int shrink_page_list(struct list_head *page_list,
page_list))
goto activate_locked;
}
if (!add_to_swap(page)) {
if (!PageTransHuge(page))
if (!add_to_swap(folio)) {
if (!folio_test_large(folio))
goto activate_locked_split;
/* Fallback to swap normal pages */
if (split_folio_to_list(folio,
@ -1741,7 +1741,7 @@ static unsigned int shrink_page_list(struct list_head *page_list,
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
count_vm_event(THP_SWPOUT_FALLBACK);
#endif
if (!add_to_swap(page))
if (!add_to_swap(folio))
goto activate_locked_split;
}