try to make Utility.Mounts portable

This is an unholy mashup, but it just might work. It works on Linux,
that's all I've tested. :)

Assistant/Threads/MountWatcher.hs

@@ -82,7 +82,7 @@ type MountPoints = S.Set FilePath
 
 {- Reads mtab, getting the current set of mount points. -}
 currentMountPoints :: IO MountPoints
-currentMountPoints = S.fromList . map mnt_dir <$> read_mtab
+currentMountPoints = S.fromList . map mnt_dir <$> getMounts
 
 {- Finds new mount points, given an old and a new set. -}
 newMountPoints :: MountPoints -> MountPoints -> MountPoints

Makefile

@@ -6,10 +6,10 @@ all=$(bins) $(mans) docs
 OS:=$(shell uname | sed 's/[-_].*//')
 ifeq ($(OS),Linux)
 BASEFLAGS_OPTS+=-DWITH_INOTIFY -DWITH_DBUS
-clibs=Utility/libdiskfree.o
+clibs=Utility/libdiskfree.o Utility/libmounts.o
 else
 BASEFLAGS_OPTS+=-DWITH_KQUEUE
-clibs=Utility/libdiskfree.o Utility/libkqueue.o
+clibs=Utility/libdiskfree.o Utility/libmounts.o Utility/libkqueue.o
 endif
 
 PREFIX=/usr

Utility/Mounts.hsc

@@ -2,6 +2,9 @@
  - 
  - Derived from hsshellscript, originally written by
  - Volker Wysk <hsss@volker-wysk.de>
+ - 
+ - Modified to support BSD and Mac OS X by
+ - Joey Hess <joey@kitenet.net>
  -
  - Licensed under the GNU LGPL version 2.1 or higher.
  -}
@@ -10,8 +13,7 @@
 
 module Utility.Mounts (
 	Mntent(..),
-	read_mtab,
-	read_fstab,
+	getMounts
 ) where
 
 import Control.Monad
@@ -20,62 +22,46 @@ import Foreign.C
 import GHC.IO hiding (finally, bracket)
 import Prelude hiding (catch)
 
-#include <stdio.h>
-#include <mntent.h>
+#include "libmounts.h"
 
+{- This is a stripped down mntent, containing only
+ - fields available everywhere. -}
 data Mntent = Mntent
 	{ mnt_fsname :: String
 	, mnt_dir :: String
 	, mnt_type :: String
-	, mnt_opts :: String
-	, mnt_freq :: Int
-	, mnt_passno :: Int
 	} deriving (Read, Show, Eq)
 
-read_mounts :: String -> IO [Mntent]
-read_mounts path = do
-	h <- withCString path $ \cpath ->
-		withCString "r" $ \r ->
-			c_setmntent cpath r
+getMounts :: IO [Mntent]
+getMounts = do
+	h <- c_mounts_start
 	when (h == nullPtr) $
-		throwErrno "setmntent"
+		throwErrno "getMounts"
 	mntent <- getmntent h []
-	_ <- c_endmntent h
+	_ <- c_mounts_end h
 	return mntent
 
 	where
-		getmntent h l = do
-			ptr <- c_getmntent h
+		getmntent h c = do
+			ptr <- c_mounts_next h
 			if (ptr == nullPtr)
-				then return $ reverse l
+				then return $ reverse c
 				else do
 					mnt_fsname_str <- #{peek struct mntent, mnt_fsname} ptr >>= peekCString
 					mnt_dir_str <- #{peek struct mntent, mnt_dir} ptr >>= peekCString
 					mnt_type_str <- #{peek struct mntent, mnt_type} ptr >>= peekCString
-					mnt_opts_str <- #{peek struct mntent, mnt_opts} ptr >>= peekCString
-					mnt_freq_int <- #{peek struct mntent, mnt_freq} ptr
-					mnt_passno_int <- #{peek struct mntent, mnt_passno} ptr
 					let ent = Mntent
 						{ mnt_fsname = mnt_fsname_str
 						, mnt_dir = mnt_dir_str
 						, mnt_type = mnt_type_str
-						, mnt_opts = mnt_opts_str
-						, mnt_freq = mnt_freq_int
-						, mnt_passno = mnt_passno_int
 						}
-					getmntent h (ent:l)
+					getmntent h (ent:c)
 
-read_mtab :: IO [Mntent]
-read_mtab = read_mounts "/etc/mtab"
+foreign import ccall unsafe "libmounts.h mounts_start" c_mounts_start
+        :: IO (Ptr ())
 
-read_fstab :: IO [Mntent]
-read_fstab = read_mounts "/etc/fstab"
+foreign import ccall unsafe "libmounts.h mounts_next" c_mounts_next
+        :: Ptr () -> IO (Ptr ())
 
-foreign import ccall safe "setmntent"
-	c_setmntent :: ((Ptr CChar) -> ((Ptr CChar) -> (IO (Ptr ()))))
-
-foreign import ccall safe "endmntent"
-	c_endmntent :: ((Ptr ()) -> (IO CInt))
-
-foreign import ccall safe "getmntent"
-	c_getmntent :: ((Ptr ()) -> (IO (Ptr ())))
+foreign import ccall unsafe "libmounts.h mounts_end" c_mounts_end
+        :: Ptr () -> IO CInt

Utility/libmounts.c

@@ -0,0 +1,105 @@
+/* mounted filesystems, C mini-library
+ *
+ * Copyright (c) 1980, 1989, 1993, 1994
+ *      The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 2001
+ *      David Rufino <daverufino@btinternet.com>
+ * Copyright 2012
+ *      Joey Hess <joey@kitenet.net>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include "libmounts.h"
+
+#include <errno.h>
+#include <stdio.h>
+
+#ifdef GETMNTENT
+/* direct passthrough the getmntent */
+FILE *mounts_start (void) {
+	return setmntent("/etc/mtab", "r");
+}
+int mounts_end (FILE *fp) {
+	return endmntent(fp);
+}
+struct mntent *mounts_next (FILE *fp) {
+	return getmntent(fp);
+}
+#endif
+
+#ifdef GETMNTINFOCALL
+/* getmntent emulation using getmntinfo */
+FILE *mounts_start (void) {
+	return ((FILE *)0x1) /* dummy non-NULL FILE pointer, not used */
+}
+int mounts_end (FILE *fp) {
+	return 1;
+}
+
+static struct mntent _mntent;
+
+static struct mntent *statfs_to_mntent (struct MNTINFOSTRUCT *mntbuf) {
+	_mntent.mnt_fsname = mntbuf->f_mntfromname;
+	_mntent.mnt_dir = mntbuf->f_mntonname;
+	_mntent.mnt_type = mntbuf->f_fstypename;
+
+	_mntent.mnt_opts = '\0';
+	_mntent.mnt_freq = 0;
+	_mntent.mnt_passno = 0;
+
+	return (&_mntent);
+}
+
+static int pos = -1;
+static int mntsize = -1;
+
+struct mntent *mounts_next (FILE *fp) {
+	struct MNTINFOSTRUCT *mntbuf;
+
+	if (pos == -1 || mntsize == -1)
+		mntsize = GETMNTINFOCALL(&mntbuf, MNT_NOWAIT);
+	++pos;
+	if (pos == mntsize) {
+		pos = mntsize = -1;
+		return NULL;
+	}
+
+	return (statfs_to_mntent(&mntbuf[pos]));
+}
+#endif
+
+#ifdef UNKNOWN
+/* dummy, do-nothing version */
+FILE *mounts_start (void) {
+	return ((FILE *)0x1);
+}
+int mounts_end (FILE *fp) {
+	return 1;
+}
+struct mntent *mounts_next (FILE *fp) {
+	return NULL;
+}
+#endif

Utility/libmounts.h

@@ -0,0 +1,48 @@
+/* Include appropriate headers for the OS, and define what will be used. */
+#if defined(__APPLE__)
+# include <sys/param.h>
+# include <sys/ucred.h>
+# include <sys/mount.h>
+/* In newer OSX versions, statfs64 is deprecated, in favor of statfs,
+ * which is 64 bit only with a build option -- but statfs64 still works,
+ * and this keeps older OSX also supported. */
+# define GETMNTINFOCALL getmntinfo64
+# define MNTINFOSTRUCT statfs64
+#else
+#if defined (__FreeBSD__)
+# include <sys/param.h>
+# include <sys/ucred.h>
+# include <sys/mount.h>
+# define GETMNTINFOCALL getmntinfo64
+# define MNTINFOSTRUCT statfs64
+#else
+#if defined (__linux__) || defined (__FreeBSD_kernel__)
+/* Linux or Debian kFreeBSD */
+#include <mntent.h>
+# define GETMNTENT
+#else
+# warning mounts listing code not available for this OS
+# define UNKNOWN
+#endif
+#endif
+#endif
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+#ifndef GETMNTENT
+#warning "boo"
+struct mntent {
+	char *mnt_fsname;
+	char *mnt_dir;
+	char *mnt_type;
+	char *mnt_opts; /* not filled in */
+	int mnt_freq; /* not filled in */
+	int mnt_passno; /* not filled in */
+};
+#endif
+
+FILE *mounts_start (void);
+int mounts_end (FILE *fp);
+struct mntent *mounts_next (FILE *fp);

debian/copyright

@@ -8,13 +8,22 @@ License: GPL-3+
  this package's source, or in /usr/share/common-licenses/GPL-3 on
  Debian systems.
 
-Files: Utility/Mtab.hcs
+Files: Utility/Mounts.hsc
 Copyright: Volker Wysk <hsss@volker-wysk.de>
 License: LGPL-2.1+
- the full text of version 2.1 of the LGPL is distributed as doc/LGPL
+ The full text of version 2.1 of the LGPL is distributed as doc/LGPL
  in this package's source, or in /usr/share/common-licences/LGPL-2.1
  on Debian systems.
 
+Files: Utility/libmounts.c
+Copyright: 1980, 1989, 1993, 1994 The Regents of the University of California
+           2001 David Rufino <daverufino@btinternet.com>
+           2012 Joey Hess <joey@kitenet.net>
+License: BSD-3-clause
+ The full test of the 3 clause BSD license is distributed inside
+ Utility/libmounts.c in this package's source, or in
+ /usr/share/common-licenses/BSD on Debian systems.
+
 Files: doc/logo.png doc/logo_small.png doc/favicon.png
 Copyright: 2007 Henrik Nyh <http://henrik.nyh.se/>
            2010 Joey Hess <joey@kitenet.net>

git-annex.cabal

@@ -46,7 +46,7 @@ Executable git-annex
    IfElse, text, QuickCheck >= 2.1, bloomfilter, edit-distance, process
   -- Need to list these because they're generated from .hsc files.
   Other-Modules: Utility.Touch Utility.Mounts
-  C-Sources: Utility/libdiskfree.c
+  C-Sources: Utility/libdiskfree.c Utility/libmounts.c
   Extensions: CPP
   GHC-Options: -threaded