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-rw-r--r--fs/aufs/poll.c52
1 files changed, 52 insertions, 0 deletions
diff --git a/fs/aufs/poll.c b/fs/aufs/poll.c
new file mode 100644
index 000000000..262a792fd
--- /dev/null
+++ b/fs/aufs/poll.c
@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2005-2015 Junjiro R. Okajima
+ *
+ * This program, aufs is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/*
+ * 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;
+}