Do not pass unsupported mount options to the kernel.

The filesystem daemon is responsible for implementing eg. st_atime updates, so passing
options like relatime to the kernel results in them being silently ignored. Instead, such
options need to be interpreted (and filtered out) by the filesystem daemon.

1 files changed, 6 insertions, 0 deletions

diff --git a/include/fuse_lowlevel.h b/include/fuse_lowlevel.h
index 6500e29..9142b1c 100644
--- a/include/fuse_lowlevel.h
+++ b/include/fuse_lowlevel.h
@@ -313,6 +313,12 @@ struct fuse_lowlevel_ops {
 	 * expected to reset the setuid and setgid bits if the file
 	 * size or owner is being changed.
 	 *
+	 * This method will not be called to update st_atime or st_ctime implicitly
+	 * (eg. after a read() request), and only be called to implicitly update st_mtime
+	 * if writeback caching is active. It is the filesystem's responsibility to update
+	 * these timestamps when needed, and (if desired) to implement mount options like
+	 * `noatime` or `relatime`.
+	 *
 	 * If the setattr was invoked from the ftruncate() system call
 	 * under Linux kernel versions 2.6.15 or later, the fi->fh will
 	 * contain the value set by the open method or will be undefined