Add ->flock() operation to low and high level interfaces

This fixes problems with emulating flock() with POSIX locking.
Reported by Sebastian Pipping.

As with lock/setlk/getlk most filesystems don't need to implement
this, as the kernel takes care of file locking.  The only reason to
implement locking operations is for network filesystems which want
file locking to work between clients.

1 files changed, 20 insertions, 1 deletions

diff --git a/include/fuse_lowlevel.h b/include/fuse_lowlevel.h
index e38fe92..7c00f76 100644
--- a/include/fuse_lowlevel.h
+++ b/include/fuse_lowlevel.h
@@ -796,7 +796,7 @@ struct fuse_lowlevel_ops {
 	 * @param req request handle
 	 * @param ino the inode number
 	 * @param fi file information
-	 * @param lock the region/type to test
+	 * @param lock the region/type to set
 	 * @param sleep locking operation may sleep
 	 */
 	void (*setlk) (fuse_req_t req, fuse_ino_t ino,
@@ -932,6 +932,25 @@ struct fuse_lowlevel_ops {
 	void (*forget_multi) (fuse_req_t req, size_t count,
 			      struct fuse_forget_data *forgets);
 
+	/**
+	 * Acquire, modify or release a BSD file lock
+	 *
+	 * Note: if the locking methods are not implemented, the kernel
+	 * will still allow file locking to work locally.  Hence these are
+	 * only interesting for network filesystems and similar.
+	 *
+	 * Introduced in version 2.9
+	 *
+	 * Valid replies:
+	 *   fuse_reply_err
+	 *
+	 * @param req request handle
+	 * @param ino the inode number
+	 * @param fi file information
+	 * @param op the locking operation, see flock(2)
+	 */
+	void (*flock) (fuse_req_t req, fuse_ino_t ino,
+		       struct fuse_file_info *fi, int op);
 };
 
 /**