The quilt patch titled
Subject: shmem: convert shmem_writepage() to use a folio throughout
has been removed from the -mm tree. Its filename was
shmem-convert-shmem_writepage-to-use-a-folio-throughout.patch
This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
------------------------------------------------------
From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
Subject: shmem: convert shmem_writepage() to use a folio throughout
Date: Fri, 2 Sep 2022 20:46:02 +0100
Even though we will split any large folio that comes in, write the code to
handle large folios so as to not leave a trap for whoever tries to handle
large folios in the swap cache.
Link: https://lkml.kernel.org/r/20220902194653.1739778-7-willy@xxxxxxxxxxxxx
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/shmem.c | 47 ++++++++++++++++++++++++-----------------------
1 file changed, 24 insertions(+), 23 deletions(-)
--- a/mm/shmem.c~shmem-convert-shmem_writepage-to-use-a-folio-throughout
+++ a/mm/shmem.c
@@ -1328,17 +1328,18 @@ static int shmem_writepage(struct page *
* "force", drivers/gpu/drm/i915/gem/i915_gem_shmem.c gets huge pages,
* and its shmem_writeback() needs them to be split when swapping.
*/
- if (PageTransCompound(page)) {
+ if (folio_test_large(folio)) {
/* Ensure the subpages are still dirty */
- SetPageDirty(page);
+ folio_test_set_dirty(folio);
if (split_huge_page(page) < 0)
goto redirty;
- ClearPageDirty(page);
+ folio = page_folio(page);
+ folio_clear_dirty(folio);
}
- BUG_ON(!PageLocked(page));
- mapping = page->mapping;
- index = page->index;
+ BUG_ON(!folio_test_locked(folio));
+ mapping = folio->mapping;
+ index = folio->index;
inode = mapping->host;
info = SHMEM_I(inode);
if (info->flags & VM_LOCKED)
@@ -1361,15 +1362,15 @@ static int shmem_writepage(struct page *
/*
* This is somewhat ridiculous, but without plumbing a SWAP_MAP_FALLOC
* value into swapfile.c, the only way we can correctly account for a
- * fallocated page arriving here is now to initialize it and write it.
+ * fallocated folio arriving here is now to initialize it and write it.
*
- * That's okay for a page already fallocated earlier, but if we have
+ * That's okay for a folio already fallocated earlier, but if we have
* not yet completed the fallocation, then (a) we want to keep track
- * of this page in case we have to undo it, and (b) it may not be a
+ * of this folio in case we have to undo it, and (b) it may not be a
* good idea to continue anyway, once we're pushing into swap. So
- * reactivate the page, and let shmem_fallocate() quit when too many.
+ * reactivate the folio, and let shmem_fallocate() quit when too many.
*/
- if (!PageUptodate(page)) {
+ if (!folio_test_uptodate(folio)) {
if (inode->i_private) {
struct shmem_falloc *shmem_falloc;
spin_lock(&inode->i_lock);
@@ -1385,9 +1386,9 @@ static int shmem_writepage(struct page *
if (shmem_falloc)
goto redirty;
}
- clear_highpage(page);
- flush_dcache_page(page);
- SetPageUptodate(page);
+ folio_zero_range(folio, 0, folio_size(folio));
+ flush_dcache_folio(folio);
+ folio_mark_uptodate(folio);
}
swap = folio_alloc_swap(folio);
@@ -1396,7 +1397,7 @@ static int shmem_writepage(struct page *
/*
* Add inode to shmem_unuse()'s list of swapped-out inodes,
- * if it's not already there. Do it now before the page is
+ * if it's not already there. Do it now before the folio is
* moved to swap cache, when its pagelock no longer protects
* the inode from eviction. But don't unlock the mutex until
* we've incremented swapped, because shmem_unuse_inode() will
@@ -1406,7 +1407,7 @@ static int shmem_writepage(struct page *
if (list_empty(&info->swaplist))
list_add(&info->swaplist, &shmem_swaplist);
- if (add_to_swap_cache(page, swap,
+ if (add_to_swap_cache(&folio->page, swap,
__GFP_HIGH | __GFP_NOMEMALLOC | __GFP_NOWARN,
NULL) == 0) {
spin_lock_irq(&info->lock);
@@ -1415,21 +1416,21 @@ static int shmem_writepage(struct page *
spin_unlock_irq(&info->lock);
swap_shmem_alloc(swap);
- shmem_delete_from_page_cache(page, swp_to_radix_entry(swap));
+ shmem_delete_from_page_cache(&folio->page, swp_to_radix_entry(swap));
mutex_unlock(&shmem_swaplist_mutex);
- BUG_ON(page_mapped(page));
- swap_writepage(page, wbc);
+ BUG_ON(folio_mapped(folio));
+ swap_writepage(&folio->page, wbc);
return 0;
}
mutex_unlock(&shmem_swaplist_mutex);
- put_swap_page(page, swap);
+ put_swap_page(&folio->page, swap);
redirty:
- set_page_dirty(page);
+ folio_mark_dirty(folio);
if (wbc->for_reclaim)
- return AOP_WRITEPAGE_ACTIVATE; /* Return with page locked */
- unlock_page(page);
+ return AOP_WRITEPAGE_ACTIVATE; /* Return with folio locked */
+ folio_unlock(folio);
return 0;
}
_
Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are
