[PATCH 06/12] mm/truncate: add folio_unmap_invalidate() helper

Jens Axboe
2024-12-20T15:48:43Z

Add a folio_unmap_invalidate() helper, which unmaps and invalidates a
given folio. The caller must already have locked the folio. Embed the
old invalidate_complete_folio2() helper in there as well, as nobody else
calls it.

Use this new helper in invalidate_inode_pages2_range(), rather than
duplicate the code there.

In preparation for using this elsewhere as well, have it take a gfp_t
mask rather than assume GFP_KERNEL is the right choice. This bubbles
back to invalidate_complete_folio2() as well.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
mm/internal.h | 2 ++
mm/truncate.c | 53 +++++++++++++++++++++++++++------------------------
2 files changed, 30 insertions(+), 25 deletions(-)

diff --git a/mm/internal.h b/mm/internal.h
index cb8d8e8e3ffa..ed3c3690eb03 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -392,6 +392,8 @@ void unmap_page_range(struct mmu_gather *tlb,
struct vm_area_struct *vma,
unsigned long addr, unsigned long end,
struct zap_details *details);
+int folio_unmap_invalidate(struct address_space *mapping, struct folio *folio,
+ gfp_t gfp);

void page_cache_ra_order(struct readahead_control *, struct file_ra_state *,
unsigned int order);
diff --git a/mm/truncate.c b/mm/truncate.c
index 7c304d2f0052..e2e115adfbc5 100644
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -525,6 +525,15 @@ unsigned long invalidate_mapping_pages(struct address_space *mapping,
}
EXPORT_SYMBOL(invalidate_mapping_pages);

+static int folio_launder(struct address_space *mapping, struct folio *folio)
+{
+ if (!folio_test_dirty(folio))
+ return 0;
+ if (folio->mapping != mapping || mapping->a_ops->launder_folio == NULL)
+ return 0;
+ return mapping->a_ops->launder_folio(folio);
+}
+
/*
* This is like mapping_evict_folio(), except it ignores the folio's
* refcount. We do this because invalidate_inode_pages2() needs stronger
@@ -532,14 +541,26 @@ EXPORT_SYMBOL(invalidate_mapping_pages);
* shrink_folio_list() has a temp ref on them, or because they're transiently
* sitting in the folio_add_lru() caches.
*/
-static int invalidate_complete_folio2(struct address_space *mapping,
- struct folio *folio)
+int folio_unmap_invalidate(struct address_space *mapping, struct folio *folio,
+ gfp_t gfp)
{
- if (folio->mapping != mapping)
- return 0;
+ int ret;
+
+ VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio);

- if (!filemap_release_folio(folio, GFP_KERNEL))
+ if (folio_test_dirty(folio))
return 0;
+ if (folio_mapped(folio))
+ unmap_mapping_folio(folio);
+ BUG_ON(folio_mapped(folio));
+
+ ret = folio_launder(mapping, folio);
+ if (ret)
+ return ret;
+ if (folio->mapping != mapping)
+ return -EBUSY;
+ if (!filemap_release_folio(folio, gfp))
+ return -EBUSY;

spin_lock(&mapping->host->i_lock);
xa_lock_irq(&mapping->i_pages);
@@ -558,16 +579,7 @@ static int invalidate_complete_folio2(struct address_space *mapping,
failed:
xa_unlock_irq(&mapping->i_pages);
spin_unlock(&mapping->host->i_lock);
- return 0;
-}
-
-static int folio_launder(struct address_space *mapping, struct folio *folio)
-{
- if (!folio_test_dirty(folio))
- return 0;
- if (folio->mapping != mapping || mapping->a_ops->launder_folio == NULL)
- return 0;
- return mapping->a_ops->launder_folio(folio);
+ return -EBUSY;
}

/**
@@ -631,16 +643,7 @@ int invalidate_inode_pages2_range(struct address_space *mapping,
}
VM_BUG_ON_FOLIO(!folio_contains(folio, indices[i]), folio);
folio_wait_writeback(folio);
-
- if (folio_mapped(folio))
- unmap_mapping_folio(folio);
- BUG_ON(folio_mapped(folio));
-
- ret2 = folio_launder(mapping, folio);
- if (ret2 == 0) {
- if (!invalidate_complete_folio2(mapping, folio))
- ret2 = -EBUSY;
- }
+ ret2 = folio_unmap_invalidate(mapping, folio, GFP_KERNEL);
if (ret2 < 0)
ret = ret2;
folio_unlock(folio);
--
2.45.2