Make expire only function fail if no kernel support (#789)

1 files changed, 36 insertions, 5 deletions

diff --git a/lib/fuse_lowlevel.c b/lib/fuse_lowlevel.c
index 1ce6083..4b9ee89 100644
--- a/lib/fuse_lowlevel.c
+++ b/lib/fuse_lowlevel.c
@@ -2305,9 +2305,28 @@ int fuse_lowlevel_notify_inval_inode(struct fuse_session *se, fuse_ino_t ino,
 	return send_notify_iov(se, FUSE_NOTIFY_INVAL_INODE, iov, 2);
 }
 
-int fuse_lowlevel_notify_expire_entry(struct fuse_session *se, fuse_ino_t parent,
-				      const char *name, size_t namelen,
-				      enum fuse_expire_flags flags)
+/**
+ * Notify parent attributes and the dentry matching parent/name
+ * 
+ * Underlying base function for fuse_lowlevel_notify_inval_entry() and
+ * fuse_lowlevel_notify_expire_entry().
+ * 
+ * @warning
+ * Only checks if fuse_lowlevel_notify_inval_entry() is supported by
+ * the kernel. All other flags will fall back to 
+ * fuse_lowlevel_notify_inval_entry() if not supported!
+ * DO THE PROPER CHECKS IN THE DERIVED FUNCTION!
+ *
+ * @param se the session object
+ * @param parent inode number
+ * @param name file name
+ * @param namelen strlen() of file name
+ * @param flags flags to control if the entry should be expired or invalidated
+ * @return zero for success, -errno for failure
+*/
+static int fuse_lowlevel_notify_entry(struct fuse_session *se, fuse_ino_t parent,
+							const char *name, size_t namelen,
+							enum fuse_notify_entry_flags flags)
 {
 	struct fuse_notify_inval_entry_out outarg;
 	struct iovec iov[3];
@@ -2333,9 +2352,21 @@ int fuse_lowlevel_notify_expire_entry(struct fuse_session *se, fuse_ino_t parent
 }
 
 int fuse_lowlevel_notify_inval_entry(struct fuse_session *se, fuse_ino_t parent,
-				     const char *name, size_t namelen)
+						 const char *name, size_t namelen)
+{
+	return fuse_lowlevel_notify_entry(se, parent, name, namelen, FUSE_LL_INVALIDATE);
+}
+
+int fuse_lowlevel_notify_expire_entry(struct fuse_session *se, fuse_ino_t parent,
+							const char *name, size_t namelen)
 {
-	return fuse_lowlevel_notify_expire_entry(se, parent, name, namelen, 0);
+	if (!se)
+		return -EINVAL;
+
+	if (!(se->conn.capable & FUSE_CAP_EXPIRE_ONLY))
+		return -ENOSYS;
+
+	return fuse_lowlevel_notify_entry(se, parent, name, namelen, FUSE_LL_EXPIRE_ONLY);
 }