X-Git-Url: https://git.karo-electronics.de/?a=blobdiff_plain;f=fs%2Fbuffer.c;h=4d7433534f5cd77b7f9b240fba57ac7923df07e6;hb=f23ceb2559ce2212e007779c1d6b1dd09c4c5242;hp=f93392e2df126fd5c17833b7105338fc6f65be5f;hpb=1b6dcfa6c084d389821dc8f612fa89ad8fe198ad;p=karo-tx-linux.git

diff --git a/fs/buffer.c b/fs/buffer.c
index f93392e2df12..4d7433534f5c 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -82,6 +82,40 @@ void unlock_buffer(struct buffer_head *bh)
 }
 EXPORT_SYMBOL(unlock_buffer);
 
+/*
+ * Returns if the page has dirty or writeback buffers. If all the buffers
+ * are unlocked and clean then the PageDirty information is stale. If
+ * any of the pages are locked, it is assumed they are locked for IO.
+ */
+void buffer_check_dirty_writeback(struct page *page,
+				     bool *dirty, bool *writeback)
+{
+	struct buffer_head *head, *bh;
+	*dirty = false;
+	*writeback = false;
+
+	BUG_ON(!PageLocked(page));
+
+	if (!page_has_buffers(page))
+		return;
+
+	if (PageWriteback(page))
+		*writeback = true;
+
+	head = page_buffers(page);
+	bh = head;
+	do {
+		if (buffer_locked(bh))
+			*writeback = true;
+
+		if (buffer_dirty(bh))
+			*dirty = true;
+
+		bh = bh->b_this_page;
+	} while (bh != head);
+}
+EXPORT_SYMBOL(buffer_check_dirty_writeback);
+
 /*
  * Block until a buffer comes unlocked.  This doesn't stop it
  * from becoming locked again - you have to lock it yourself