1 files changed, 39 insertions, 0 deletions
diff --git a/fs/aufs/poll.c b/fs/aufs/poll.c
new file mode 100644
index 000000000..dd2baf5dc
--- /dev/null
+++ b/fs/aufs/poll.c
@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) 2005-2016 Junjiro R. Okajima
+ */
+
+/*
+ * poll operation
+ * There is only one filesystem which implements ->poll operation, currently.
+ */
+
+#include "aufs.h"
+
+unsigned int aufs_poll(struct file *file, poll_table *wait)
+{
+	unsigned int mask;
+	int err;
+	struct file *h_file;
+	struct super_block *sb;
+
+	/* We should pretend an error happened. */
+	mask = POLLERR /* | POLLIN | POLLOUT */;
+	sb = file->f_path.dentry->d_sb;
+	si_read_lock(sb, AuLock_FLUSH | AuLock_NOPLMW);
+
+	h_file = au_read_pre(file, /*keep_fi*/0);
+	err = PTR_ERR(h_file);
+	if (IS_ERR(h_file))
+		goto out;
+
+	/* it is not an error if h_file has no operation */
+	mask = DEFAULT_POLLMASK;
+	if (h_file->f_op->poll)
+		mask = h_file->f_op->poll(h_file, wait);
+	fput(h_file); /* instead of au_read_post() */
+
+out:
+	si_read_unlock(sb);
+	AuTraceErr((int)mask);
+	return mask;
+}