Added support for FUSE_EXPLICIT_INVAL_DATA to enable (#474)

1 files changed, 23 insertions, 0 deletions

diff --git a/include/fuse_common.h b/include/fuse_common.h
index 2d686b2..77d4bfe 100644
--- a/include/fuse_common.h
+++ b/include/fuse_common.h
@@ -359,6 +359,29 @@ struct fuse_loop_config {
 #define FUSE_CAP_NO_OPENDIR_SUPPORT    (1 << 24)
 
 /**
+ * Indicates support for invalidating cached pages only on explicit request.
+ *
+ * If this flag is set in the `capable` field of the `fuse_conn_info` structure,
+ * then the FUSE kernel module supports invalidating cached pages only on
+ * explicit request by the filesystem through fuse_lowlevel_notify_inval_inode()
+ * or fuse_invalidate_path().
+ *
+ * By setting this flag in the `want` field of the `fuse_conn_info` structure,
+ * the filesystem is responsible for invalidating cached pages through explicit
+ * requests to the kernel.
+ *
+ * Note that setting this flag does not prevent the cached pages from being
+ * flushed by OS itself and/or through user actions.
+ *
+ * Note that if both FUSE_CAP_EXPLICIT_INVAL_DATA and FUSE_CAP_AUTO_INVAL_DATA
+ * are set in the `capable` field of the `fuse_conn_info` structure then
+ * FUSE_CAP_AUTO_INVAL_DATA takes precedence.
+ *
+ * This feature is disabled by default.
+ */
+#define FUSE_CAP_EXPLICIT_INVAL_DATA    (1 << 25)
+
+/**
  * Ioctl flags
  *
  * FUSE_IOCTL_COMPAT: 32bit compat ioctl on 64bit machine