support RHEL6

closes: #29

Makefile

@@ -21,18 +21,19 @@
 # THE SOFTWARE.
 
 PKGCONFIG =  	$(shell which pkg-config)
-GIT 	= 	$(shell which git)
-TAR 	= 	$(shell which tar)
-MKDIR   = 	$(shell which mkdir)
-TOUCH 	= 	$(shell which touch)
-CP      = 	$(shell which cp)
-RM 	= 	$(shell which rm)
-FIND 	= 	$(shell which find)
-INSTALL = 	$(shell which install)
-MKTEMP  = 	$(shell which mktemp)
-STRIP   = 	$(shell which strip)
-PANDOC  =       $(shell which pandoc)
+GIT 	  = 	$(shell which git)
+TAR 	  = 	$(shell which tar)
+MKDIR     = 	$(shell which mkdir)
+TOUCH 	  = 	$(shell which touch)
+CP        = 	$(shell which cp)
+RM 	  = 	$(shell which rm)
+FIND 	  = 	$(shell which find)
+INSTALL   = 	$(shell which install)
+MKTEMP    = 	$(shell which mktemp)
+STRIP     = 	$(shell which strip)
+PANDOC    =	$(shell which pandoc)
 GIT2DEBCL =     ./tools/git2debcl
+CPPFIND   =     ./tools/cppfind
 
 ifeq ($(PKGCONFIG),"")
 $(error "pkg-config not installed"
@@ -54,23 +55,35 @@ ifeq ($(FUSE_AVAILABLE),0)
 $(error "FUSE development package doesn't appear available")
 endif
 
-OPTS 	= 	-O2
-SRC	=	$(wildcard src/*.cpp)
-OBJ     =       $(SRC:src/%.cpp=obj/%.o)
-DEPS    =       $(OBJ:obj/%.o=obj/%.d)
-TARGET  =       mergerfs
-MANPAGE = 	$(TARGET).1
-CFLAGS  =       -g -Wall \
-		$(OPTS) \
-                $(shell $(PKGCONFIG) fuse --cflags) \
-                -DFUSE_USE_VERSION=26 \
-                -MMD
-LDFLAGS	=       $(shell $(PKGCONFIG) fuse --libs)
-
-BINDIR 	=	$(PREFIX)/usr/bin
-MANDIR 	=	$(PREFIX)/usr/share/man/man1
+FLAG_NOPATH = $(shell $(CPPFIND) "flag_nopath")
+FALLOCATE   = $(shell $(CPPFIND) "fuse_fs_fallocate")
+FLOCK       = $(shell $(CPPFIND) "fuse_fs_flock")
+READ_BUF    = $(shell $(CPPFIND) "fuse_fs_read_buf")
+WRITE_BUF   = $(shell $(CPPFIND) "fuse_fs_write_buf")
+
+OPTS 	    = -O2
+SRC	    = $(wildcard src/*.cpp)
+OBJ         = $(SRC:src/%.cpp=obj/%.o)
+DEPS        = $(OBJ:obj/%.o=obj/%.d)
+TARGET      = mergerfs
+MANPAGE     = $(TARGET).1
+FUSE_CFLAGS = $(shell $(PKGCONFIG) --cflags fuse)
+CFLAGS      = -g -Wall \
+	      $(OPTS) \
+              $(FUSE_CFLAGS) \
+              -DFUSE_USE_VERSION=26 \
+              -MMD \
+	      -DFLAG_NOPATH=$(FLAG_NOPATH) \
+	      -DFALLOCATE=$(FALLOCATE) \
+              -DFLOCK=$(FLOCK) \
+	      -DREAD_BUF=$(READ_BUF) \
+              -DWRITE_BUF=$(WRITE_BUF)
+LDFLAGS       = $(shell $(PKGCONFIG) fuse --libs)
+
+BINDIR 	      =	$(PREFIX)/usr/bin
+MANDIR 	      =	$(PREFIX)/usr/share/man/man1
 INSTALLTARGET = $(DESTDIR)/$(BINDIR)/$(TARGET)
-MANTARGET = 	$(DESTDIR)/$(MANDIR)/$(MANPAGE)
+MANTARGET     =	$(DESTDIR)/$(MANDIR)/$(MANPAGE)
 
 ifeq ($(XATTR_AVAILABLE),0)
 $(warning "xattr not available: disabling")

src/fallocate.cpp

@@ -22,6 +22,8 @@
    THE SOFTWARE.
 */
 
+#if FALLOCATE
+
 #ifndef _GNU_SOURCE
 #define _GNU_SOURCE
 #endif
@@ -82,3 +84,5 @@ namespace mergerfs
     }
   }
 }
+
+#endif

src/init.cpp

@@ -33,7 +33,9 @@ namespace mergerfs
     void *
     init(struct fuse_conn_info *conn)
     {
+#ifdef FUSE_CAP_IOCTL_DIR
       conn->want |= FUSE_CAP_IOCTL_DIR;
+#endif
 
       return &config::get_writable();
     }

src/ioctl.cpp

@@ -80,6 +80,7 @@ _ioctl(const int           fd,
   return ((rv == -1) ? -errno : rv);
 }
 
+#ifdef FUSE_IOCTL_DIR
 static
 int
 _ioctl_dir_base(const fs::SearchFunc  searchFunc,
@@ -130,6 +131,7 @@ _ioctl_dir(const string        fusepath,
                          flags,
                          data);
 }
+#endif
 
 namespace mergerfs
 {
@@ -145,12 +147,14 @@ namespace mergerfs
     {
       const FileInfo *fileinfo = (FileInfo*)ffi->fh;
 
+#ifdef FUSE_IOCTL_DIR
       if(flags & FUSE_IOCTL_DIR)
         return _ioctl_dir(fusepath,
                           cmd,
                           arg,
                           flags,
                           data);
+#endif
 
       return _ioctl(fileinfo->fd,
                     cmd,

src/mergerfs.cpp

@@ -76,9 +76,11 @@ static
 struct fuse_operations
 get_fuse_operations()
 {
-  struct fuse_operations ops = {};
+  struct fuse_operations ops = {0};
 
+#if FLAG_NOPATH
   ops.flag_nopath      = false;
+#endif
   ops.flag_nullpath_ok = false;
 
   ops.access      = mergerfs::access::access;
@@ -87,9 +89,13 @@ get_fuse_operations()
   ops.chown       = mergerfs::chown::chown;
   ops.create      = mergerfs::create::create;
   ops.destroy     = mergerfs::destroy::destroy;
+#if FALLOCATE
   ops.fallocate   = mergerfs::fallocate::fallocate;
+#endif
   ops.fgetattr    = mergerfs::fgetattr::fgetattr;
+#if FLOCK
   ops.flock       = NULL;
+#endif
   ops.flush       = mergerfs::flush::flush;
   ops.fsync       = mergerfs::fsync::fsync;
   ops.fsyncdir    = NULL;
@@ -108,7 +114,9 @@ get_fuse_operations()
   ops.opendir     = mergerfs::opendir::opendir;
   ops.poll        = NULL;
   ops.read        = mergerfs::read::read;
+#if READ_BUF
   ops.read_buf    = mergerfs::read_buf::read_buf;
+#endif
   ops.readdir     = mergerfs::readdir::readdir;
   ops.readlink    = mergerfs::readlink::readlink;
   ops.release     = mergerfs::release::release;
@@ -124,7 +132,9 @@ get_fuse_operations()
   ops.utime       = NULL;       /* deprecated; use utimens() */
   ops.utimens     = mergerfs::utimens::utimens;
   ops.write       = mergerfs::write::write;
+#if WRITE_BUF
   ops.write_buf   = mergerfs::write_buf::write_buf;
+#endif
 
   return ops;
 }

src/read_buf.cpp

@@ -22,6 +22,8 @@
    THE SOFTWARE.
 */
 
+#if READ_BUF
+
 #include <fuse.h>
 
 #include <stdlib.h>
@@ -72,3 +74,5 @@ namespace mergerfs
     }
   }
 }
+
+#endif

src/write_buf.cpp

@@ -22,6 +22,8 @@
    THE SOFTWARE.
 */
 
+#if WRITE_BUF
+
 #include <fuse.h>
 
 #include <stdlib.h>
@@ -63,3 +65,5 @@ namespace mergerfs
     }
   }
 }
+
+#endif

tools/cppfind

@@ -0,0 +1,7 @@
+#!/bin/bash
+
+FUSE_CFLAGS=$(pkg-config --cflags fuse)
+
+echo "#include <fuse.h>" | cpp ${FUSE_CFLAGS} | grep -q "${1}"
+
+[ "$?" != "0" ]; echo $?