fs: Change try_to_free_buffers() to take a folio

All but two of the callers already have a folio; pass a folio into
try_to_free_buffers().  This removes the last user of cancel_dirty_page()
so remove that wrapper function too.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Jeff Layton <jlayton@kernel.org>

fs/buffer.c

@@ -955,7 +955,7 @@ grow_dev_page(struct block_device *bdev, sector_t block,
 						size);
 			goto done;
 		}
-		if (!try_to_free_buffers(page))
+		if (!try_to_free_buffers(page_folio(page)))
 			goto failed;
 	}
 
@@ -3155,20 +3155,20 @@ int sync_dirty_buffer(struct buffer_head *bh)
 EXPORT_SYMBOL(sync_dirty_buffer);
 
 /*
- * try_to_free_buffers() checks if all the buffers on this particular page
+ * try_to_free_buffers() checks if all the buffers on this particular folio
  * are unused, and releases them if so.
  *
  * Exclusion against try_to_free_buffers may be obtained by either
- * locking the page or by holding its mapping's private_lock.
+ * locking the folio or by holding its mapping's private_lock.
  *
- * If the page is dirty but all the buffers are clean then we need to
- * be sure to mark the page clean as well.  This is because the page
+ * If the folio is dirty but all the buffers are clean then we need to
+ * be sure to mark the folio clean as well.  This is because the folio
  * may be against a block device, and a later reattachment of buffers
- * to a dirty page will set *all* buffers dirty.  Which would corrupt
+ * to a dirty folio will set *all* buffers dirty.  Which would corrupt
  * filesystem data on the same device.
  *
- * The same applies to regular filesystem pages: if all the buffers are
- * clean then we set the page clean and proceed.  To do that, we require
+ * The same applies to regular filesystem folios: if all the buffers are
+ * clean then we set the folio clean and proceed.  To do that, we require
  * total exclusion from block_dirty_folio().  That is obtained with
  * private_lock.
  *
@@ -3207,40 +3207,40 @@ drop_buffers(struct page *page, struct buffer_head **buffers_to_free)
 	return 0;
 }
 
-int try_to_free_buffers(struct page *page)
+bool try_to_free_buffers(struct folio *folio)
 {
-	struct address_space * const mapping = page->mapping;
+	struct address_space * const mapping = folio->mapping;
 	struct buffer_head *buffers_to_free = NULL;
-	int ret = 0;
+	bool ret = 0;
 
-	BUG_ON(!PageLocked(page));
-	if (PageWriteback(page))
-		return 0;
+	BUG_ON(!folio_test_locked(folio));
+	if (folio_test_writeback(folio))
+		return false;
 
 	if (mapping == NULL) {		/* can this still happen? */
-		ret = drop_buffers(page, &buffers_to_free);
+		ret = drop_buffers(&folio->page, &buffers_to_free);
 		goto out;
 	}
 
 	spin_lock(&mapping->private_lock);
-	ret = drop_buffers(page, &buffers_to_free);
+	ret = drop_buffers(&folio->page, &buffers_to_free);
 
 	/*
 	 * If the filesystem writes its buffers by hand (eg ext3)
-	 * then we can have clean buffers against a dirty page.  We
-	 * clean the page here; otherwise the VM will never notice
+	 * then we can have clean buffers against a dirty folio.  We
+	 * clean the folio here; otherwise the VM will never notice
 	 * that the filesystem did any IO at all.
 	 *
 	 * Also, during truncate, discard_buffer will have marked all
-	 * the page's buffers clean.  We discover that here and clean
-	 * the page also.
+	 * the folio's buffers clean.  We discover that here and clean
+	 * the folio also.
 	 *
 	 * private_lock must be held over this entire operation in order
 	 * to synchronise against block_dirty_folio and prevent the
 	 * dirty bit from being lost.
 	 */
 	if (ret)
-		cancel_dirty_page(page);
+		folio_cancel_dirty(folio);
 	spin_unlock(&mapping->private_lock);
 out:
 	if (buffers_to_free) {

fs/ext4/inode.c

@@ -3255,7 +3255,7 @@ static bool ext4_release_folio(struct folio *folio, gfp_t wait)
 	if (journal)
 		return jbd2_journal_try_to_free_buffers(journal, folio);
 	else
-		return try_to_free_buffers(&folio->page);
+		return try_to_free_buffers(folio);
 }
 
 static bool ext4_inode_datasync_dirty(struct inode *inode)

fs/gfs2/aops.c

@@ -757,7 +757,7 @@ bool gfs2_release_folio(struct folio *folio, gfp_t gfp_mask)
 	} while (bh != head);
 	gfs2_log_unlock(sdp);
 
-	return try_to_free_buffers(&folio->page);
+	return try_to_free_buffers(folio);
 
 cannot_release:
 	gfs2_log_unlock(sdp);

fs/hfs/inode.c

@@ -124,7 +124,7 @@ static bool hfs_release_folio(struct folio *folio, gfp_t mask)
 		} while (--i && nidx < tree->node_count);
 		spin_unlock(&tree->hash_lock);
 	}
-	return res ? try_to_free_buffers(&folio->page) : false;
+	return res ? try_to_free_buffers(folio) : false;
 }
 
 static ssize_t hfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)

fs/hfsplus/inode.c

@@ -121,7 +121,7 @@ static bool hfsplus_release_folio(struct folio *folio, gfp_t mask)
 		} while (--i && nidx < tree->node_count);
 		spin_unlock(&tree->hash_lock);
 	}
-	return res ? try_to_free_buffers(&folio->page) : false;
+	return res ? try_to_free_buffers(folio) : false;
 }
 
 static ssize_t hfsplus_direct_IO(struct kiocb *iocb, struct iov_iter *iter)

fs/jbd2/commit.c

@@ -82,7 +82,7 @@ static void release_buffer_page(struct buffer_head *bh)
 
 	folio_get(folio);
 	__brelse(bh);
-	try_to_free_buffers(&folio->page);
+	try_to_free_buffers(folio);
 	folio_unlock(folio);
 	folio_put(folio);
 	return;

fs/jbd2/transaction.c

@@ -2175,7 +2175,7 @@ bool jbd2_journal_try_to_free_buffers(journal_t *journal, struct folio *folio)
 			goto busy;
 	} while ((bh = bh->b_this_page) != head);
 
-	ret = try_to_free_buffers(&folio->page);
+	ret = try_to_free_buffers(folio);
 busy:
 	return ret;
 }
@@ -2482,7 +2482,7 @@ int jbd2_journal_invalidate_folio(journal_t *journal, struct folio *folio,
 	} while (bh != head);
 
 	if (!partial_page) {
-		if (may_free && try_to_free_buffers(&folio->page))
+		if (may_free && try_to_free_buffers(folio))
 			J_ASSERT(!folio_buffers(folio));
 	}
 	return 0;

fs/mpage.c

@@ -431,7 +431,7 @@ static void clean_buffers(struct page *page, unsigned first_unmapped)
 	 * disk before we reach the platter.
 	 */
 	if (buffer_heads_over_limit && PageUptodate(page))
-		try_to_free_buffers(page);
+		try_to_free_buffers(page_folio(page));
 }
 
 /*

fs/ocfs2/aops.c

@@ -502,7 +502,7 @@ static bool ocfs2_release_folio(struct folio *folio, gfp_t wait)
 {
 	if (!folio_buffers(folio))
 		return false;
-	return try_to_free_buffers(&folio->page);
+	return try_to_free_buffers(folio);
 }
 
 static void ocfs2_figure_cluster_boundaries(struct ocfs2_super *osb,

fs/reiserfs/inode.c

@@ -3234,7 +3234,7 @@ static bool reiserfs_release_folio(struct folio *folio, gfp_t unused_gfp_flags)
 		bh = bh->b_this_page;
 	} while (bh != head);
 	if (ret)
-		ret = try_to_free_buffers(&folio->page);
+		ret = try_to_free_buffers(folio);
 	spin_unlock(&j->j_dirty_buffers_lock);
 	return ret;
 }

fs/reiserfs/journal.c

@@ -606,7 +606,7 @@ static void release_buffer_page(struct buffer_head *bh)
 		folio_get(folio);
 		put_bh(bh);
 		if (!folio->mapping)
-			try_to_free_buffers(&folio->page);
+			try_to_free_buffers(folio);
 		folio_unlock(folio);
 		folio_put(folio);
 	} else {

include/linux/buffer_head.h

@@ -158,7 +158,7 @@ void mark_buffer_write_io_error(struct buffer_head *bh);
 void touch_buffer(struct buffer_head *bh);
 void set_bh_page(struct buffer_head *bh,
 		struct page *page, unsigned long offset);
-int try_to_free_buffers(struct page *);
+bool try_to_free_buffers(struct folio *);
 struct buffer_head *alloc_page_buffers(struct page *page, unsigned long size,
 		bool retry);
 void create_empty_buffers(struct page *, unsigned long,
@@ -402,7 +402,7 @@ bool block_dirty_folio(struct address_space *mapping, struct folio *folio);
 #else /* CONFIG_BLOCK */
 
 static inline void buffer_init(void) {}
-static inline int try_to_free_buffers(struct page *page) { return 1; }
+static inline bool try_to_free_buffers(struct folio *folio) { return true; }
 static inline int inode_has_buffers(struct inode *inode) { return 0; }
 static inline void invalidate_inode_buffers(struct inode *inode) {}
 static inline int remove_inode_buffers(struct inode *inode) { return 1; }

include/linux/pagemap.h

@@ -1067,10 +1067,6 @@ static inline void folio_cancel_dirty(struct folio *folio)
 	if (folio_test_dirty(folio))
 		__folio_cancel_dirty(folio);
 }
-static inline void cancel_dirty_page(struct page *page)
-{
-	folio_cancel_dirty(page_folio(page));
-}
 bool folio_clear_dirty_for_io(struct folio *folio);
 bool clear_page_dirty_for_io(struct page *page);
 void folio_invalidate(struct folio *folio, size_t offset, size_t length);

mm/filemap.c

@@ -3957,6 +3957,6 @@ bool filemap_release_folio(struct folio *folio, gfp_t gfp)
 
 	if (mapping && mapping->a_ops->release_folio)
 		return mapping->a_ops->release_folio(folio, gfp);
-	return try_to_free_buffers(&folio->page);
+	return try_to_free_buffers(folio);
 }
 EXPORT_SYMBOL(filemap_release_folio);

mm/migrate.c

@@ -1013,7 +1013,7 @@ static int __unmap_and_move(struct page *page, struct page *newpage,
 	if (!page->mapping) {
 		VM_BUG_ON_PAGE(PageAnon(page), page);
 		if (page_has_private(page)) {
-			try_to_free_buffers(page);
+			try_to_free_buffers(folio);
 			goto out_unlock_both;
 		}
 	} else if (page_mapped(page)) {

mm/vmscan.c

@@ -1181,7 +1181,7 @@ static pageout_t pageout(struct folio *folio, struct address_space *mapping)
 		 * folio->mapping == NULL while being dirty with clean buffers.
 		 */
 		if (folio_test_private(folio)) {
-			if (try_to_free_buffers(&folio->page)) {
+			if (try_to_free_buffers(folio)) {
 				folio_clear_dirty(folio);
 				pr_info("%s: orphaned folio\n", __func__);
 				return PAGE_CLEAN;