Require at least FUSE 2.8, and 2.9 for lock forwarding.

Fixes #40.

3 files changed, 20 insertions, 1 deletions

diff --git a/ChangeLog b/ChangeLog
index c63e707..3633f60 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2016-10-02  Martin Pärtel <martin dot partel at gmail dot com>
+
+	* Require FUSE 2.9 at compile-time.
+	* Also compile with FUSE 2.8, but without support for lock forwarding.
+
 2016-09-25  Martin Pärtel <martin dot partel at gmail dot com>
 
 	* Fix bug in readdir() introduced with 1.13.1. This fixes a bug when
diff --git a/configure.ac b/configure.ac
index 59d3bdb..306f4a7 100644
--- a/configure.ac
+++ b/configure.ac
@@ -60,7 +60,9 @@ AC_COMPILE_IFELSE(
 )
 
 # Check for fuse
-PKG_CHECK_MODULES([fuse], [fuse >= 2.6.0])
+PKG_CHECK_MODULES([fuse], [fuse >= 2.9.0],
+    [AC_DEFINE([HAVE_FUSE_29], [1], [Have FUSE >= 2.9.0])],
+    [PKG_CHECK_MODULES([fuse], [fuse >= 2.8.0])])
 
 AC_CONFIG_FILES([Makefile \
 	src/Makefile \
diff --git a/src/bindfs.c b/src/bindfs.c
index 004c771..460f362 100644
--- a/src/bindfs.c
+++ b/src/bindfs.c
@@ -1103,6 +1103,7 @@ static int bindfs_write(const char *path, const char *buf, size_t size,
     return res;
 }
 
+/* This callback is only installed if lock forwarding is enabled. */
 static int bindfs_lock(const char *path, struct fuse_file_info *fi, int cmd,
                        struct flock *lock)
 {
@@ -1113,6 +1114,7 @@ static int bindfs_lock(const char *path, struct fuse_file_info *fi, int cmd,
   return 0;
 }
 
+/* This callback is only installed if lock forwarding is enabled. */
 static int bindfs_flock(const char *path, struct fuse_file_info *fi, int op)
 {
     int res = flock(fi->fh, op);
@@ -1378,8 +1380,10 @@ static struct fuse_operations bindfs_oper = {
     .open       = bindfs_open,
     .read       = bindfs_read,
     .write      = bindfs_write,
+#ifdef HAVE_FUSE_29
     .lock       = bindfs_lock,
     .flock      = bindfs_flock,
+#endif
     .ioctl      = bindfs_ioctl,
     .statfs     = bindfs_statfs,
     .release    = bindfs_release,
@@ -2220,6 +2224,7 @@ int main(int argc, char *argv[])
         bindfs_oper.removexattr = NULL;
     }
 
+#ifdef HAVE_FUSE_29
     /* Check that lock forwarding is not enabled in single-threaded mode. */
     if (settings.enable_lock_forwarding && !od.multithreaded) {
         fprintf(stderr, "To use --enable-lock-forwarding, you must use "
@@ -2233,6 +2238,13 @@ int main(int argc, char *argv[])
         bindfs_oper.lock = NULL;
         bindfs_oper.flock = NULL;
     }
+#else
+    if (settings.enable_lock_forwarding) {
+        fprintf(stderr, "To use --enable-lock-forwarding, bindfs must be "
+                        "compiled with FUSE 2.9.0 or newer.\n");
+        return 1;
+    }
+#endif
 
     /* Remove the ioctl implementation unless the user has enabled it */
     if (!settings.enable_ioctl) {