pipe: add documentation and comments
As per Andrew Mortons request, here's a set of documentation for
the generic pipe_buf_operations hooks, the pipe, and pipe_buffer
structures.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/fs/splice.c b/fs/splice.c
index c8041216..ed2ce99 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -85,6 +85,10 @@
buf->flags &= ~PIPE_BUF_FLAG_LRU;
}
+/*
+ * Check whether the contents of buf is OK to access. Since the content
+ * is a page cache page, IO may be in flight.
+ */
static int page_cache_pipe_buf_confirm(struct pipe_inode_info *pipe,
struct pipe_buffer *buf)
{