support FUSE_TMPFILE in the low level API

Note that name hashes and using paths as parameters
makes it very hard to support
anonymous files in the high level API.

Known Issues:
- tests have to bail out when O_TMPFILE is not supported.
This will always be the case with high level passthrough implementations.
- test_create_and_link_tmpfile has to be skipped
due to unidentified problems with github runner

1 files changed, 23 insertions, 0 deletions

diff --git a/include/fuse_lowlevel.h b/include/fuse_lowlevel.h
index e5c308c..3d398de 100644
--- a/include/fuse_lowlevel.h
+++ b/include/fuse_lowlevel.h
@@ -1302,6 +1302,29 @@ struct fuse_lowlevel_ops {
 	 */
 	void (*lseek) (fuse_req_t req, fuse_ino_t ino, off_t off, int whence,
 		       struct fuse_file_info *fi);
+
+
+	/**
+	 * Create a tempfile
+	 * 
+	 * Tempfile means an anonymous file. It can be made into a normal file later
+	 * by using linkat or such.
+	 * 
+	 * If this is answered with an error ENOSYS this is treated by the kernel as 
+	 * a permanent failure and it will disable the feature and not ask again.
+	 *
+	 * Valid replies:
+	 *   fuse_reply_create
+	 *   fuse_reply_err
+	 *
+	 * @param req request handle
+	 * @param parent inode number of the parent directory
+	 * @param mode file type and mode with which to create the new file
+	 * @param fi file information
+	 */
+	void (*tmpfile) (fuse_req_t req, fuse_ino_t parent,
+			mode_t mode, struct fuse_file_info *fi);
+
 };
 
 /**