Patch series "Further set_page_dirty cleanups".
Prompted by Christoph's recent patches, here are some more patches to
improve the state of set_page_dirty().  They're all from the folio tree,
so they've been tested to a certain extent.
This patch (of 6):
Nothing in __set_page_dirty() is specific to buffer_head, so move it to
mm/page-writeback.c.  That removes the only caller of
account_page_dirtied() outside of page-writeback.c, so make it static.
Link: https://lkml.kernel.org/r/20210615162342.1669332-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20210615162342.1669332-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 
 }
 EXPORT_SYMBOL(mark_buffer_dirty_inode);
 
-/*
- * Mark the page dirty, and set it dirty in the page cache, and mark the inode
- * dirty.
- *
- * If warn is true, then emit a warning if the page is not uptodate and has
- * not been truncated.
- *
- * The caller must hold lock_page_memcg().
- */
-void __set_page_dirty(struct page *page, struct address_space *mapping,
-                            int warn)
-{
-       unsigned long flags;
-
-       xa_lock_irqsave(&mapping->i_pages, flags);
-       if (page->mapping) {    /* Race with truncate? */
-               WARN_ON_ONCE(warn && !PageUptodate(page));
-               account_page_dirtied(page, mapping);
-               __xa_set_mark(&mapping->i_pages, page_index(page),
-                               PAGECACHE_TAG_DIRTY);
-       }
-       xa_unlock_irqrestore(&mapping->i_pages, flags);
-}
-
 /*
  * Add a page to the dirty page list.
  *
 
 int __set_page_dirty_no_writeback(struct page *page);
 int redirty_page_for_writepage(struct writeback_control *wbc,
                                struct page *page);
-void account_page_dirtied(struct page *page, struct address_space *mapping);
 void account_page_cleaned(struct page *page, struct address_space *mapping,
                          struct bdi_writeback *wb);
 int set_page_dirty(struct page *page);
 
  *
  * NOTE: This relies on being atomic wrt interrupts.
  */
-void account_page_dirtied(struct page *page, struct address_space *mapping)
+static void account_page_dirtied(struct page *page,
+               struct address_space *mapping)
 {
        struct inode *inode = mapping->host;
 
        }
 }
 
+/*
+ * Mark the page dirty, and set it dirty in the page cache, and mark the inode
+ * dirty.
+ *
+ * If warn is true, then emit a warning if the page is not uptodate and has
+ * not been truncated.
+ *
+ * The caller must hold lock_page_memcg().
+ */
+void __set_page_dirty(struct page *page, struct address_space *mapping,
+                            int warn)
+{
+       unsigned long flags;
+
+       xa_lock_irqsave(&mapping->i_pages, flags);
+       if (page->mapping) {    /* Race with truncate? */
+               WARN_ON_ONCE(warn && !PageUptodate(page));
+               account_page_dirtied(page, mapping);
+               __xa_set_mark(&mapping->i_pages, page_index(page),
+                               PAGECACHE_TAG_DIRTY);
+       }
+       xa_unlock_irqrestore(&mapping->i_pages, flags);
+}
+
 /*
  * For address_spaces which do not use buffers.  Just tag the page as dirty in
  * the xarray.