[PATCH] Trying to finalize loose ends of truncate.c fallocate

[Matej Cepl]

* man/mkfile.8.xml: temporarily example of manpage for mkfile
* src/mkfile: script to use truncate to emulate mkfile(8)
* src/truncate.c: add option -a to user posix_fallocate before
  creating a file
* tests/misc/truncate-fallocate: test truncate fallocate
  functionality
* tests/misc/truncate-mkfile: test mkfile(8)

Signed-off-by: Matej Cepl <address@hidden>
---
 doc/coreutils.texi            |    9 ++++
 man/mkfile.8.xml              |   94 +++++++++++++++++++++++++++++++++++++++++
 src/mkfile                    |   81 +++++++++++++++++++++++++++++++++++
 src/truncate.c                |   48 +++++++++++++++------
 tests/Makefile.am             |    1 +
 tests/misc/truncate-fallocate |   57 +++++++++++++++++++++++++
 tests/misc/truncate-mkfile    |   72 +++++++++++++++++++++++++++++++
 7 files changed, 349 insertions(+), 13 deletions(-)
 create mode 100644 man/mkfile.8.xml
 create mode 100755 src/mkfile
 create mode 100755 tests/misc/truncate-fallocate
 create mode 100755 tests/misc/truncate-mkfile

diff --git a/doc/coreutils.texi b/doc/coreutils.texi
index 2c1fae5..d318e8d 100644
--- a/doc/coreutils.texi
+++ b/doc/coreutils.texi
@@ -10491,6 +10491,15 @@ The program accepts the following options.  Also see 
@ref{Common options}.
 
 @table @samp
 
address@hidden -a
address@hidden --fallocate
address@hidden -a
address@hidden --fallocate
+When extending file use system call @command{fallocate}, which
+ensures that disk space is allocated for @var{FILE}. After a successful
+call subsequent writes in the specified files are guaranteed
+not to fail because of lack of disk space.
+
 @item -c
 @itemx --no-create
 @opindex -c
diff --git a/man/mkfile.8.xml b/man/mkfile.8.xml
new file mode 100644
index 0000000..ba3d0b4
--- /dev/null
+++ b/man/mkfile.8.xml
@@ -0,0 +1,94 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN"
+                   "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd";>
+<!-- lifted from troff+man by doclifter -->
+<refentry id='mkfile8'>
+<!--  Copyright (c) 2007 -->
+<!--   MATEJ Cepl.  All rights reserved. -->
+<!--  Copyright (c) 2001, 2003, 2004 -->
+<!--   HATANOU Tomomi.  All rights reserved. -->
+
+<!--  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. 
-->
+<!--   @(#)mkfile.8    1.3 (HATANOU Tomomi) 2004/01/21 -->
+
+<info>
+    <date>2007-09-03</date>
+    <author>Matěj Cepl &lt;address@hidden&gt;</author>
+</info>
+<refmeta>
+<refentrytitle>MKFILE</refentrytitle>
+<manvolnum>8</manvolnum>
+<refmiscinfo class='date'>2007-09-03</refmiscinfo>
+<refmiscinfo class='source'>GNU</refmiscinfo>
+<refmiscinfo class='manual'>GNU</refmiscinfo>
+</refmeta>
+<refnamediv id='name'>
+<refname>mkfile</refname>
+<refpurpose>create a file</refpurpose>
+</refnamediv>
+<!-- body begins here -->
+<refsynopsisdiv id='synopsis'>
+<cmdsynopsis>
+  <command>mkfile</command>    <arg choice='opt'>-n </arg>
+    <arg choice='opt'>-v </arg>
+    <arg choice='plain'><replaceable>size</replaceable></arg>
+    <group choice='plain'><arg 
choice='plain'><replaceable>e</replaceable></arg><arg 
choice='plain'><replaceable>p</replaceable></arg><arg 
choice='plain'><replaceable>t</replaceable></arg><arg 
choice='plain'><replaceable>g</replaceable></arg><arg 
choice='plain'><replaceable>m</replaceable></arg><arg 
choice='plain'><replaceable>k</replaceable></arg><arg 
choice='plain'><replaceable>b</replaceable></arg><arg 
choice='plain'><replaceable>filename</replaceable></arg></group>
+</cmdsynopsis>
+</refsynopsisdiv>
+
+
+<refsect1 id='description'><title>DESCRIPTION</title>
+<para>creates a file named
+<emphasis remap='I'>filename</emphasis>
+that are suitable for use as NFS-mounted swap areas,
+or as local swap areas.
+The file is padded with zeros by default.
+The default
+<emphasis remap='I'>size</emphasis>
+is in bytes, but it can be flagged as exabytes, petabytes, terabytes, 
gigabytes, megabytes, kilobytes, or blocks, with the e, p, t, g, m, k, or b 
suffixes, respectively.</para>
+</refsect1>
+
+<refsect1 id='options'><title>OPTIONS</title>
+<para>The following options are available:</para>
+<variablelist remap='TP'>
+  <varlistentry>
+  <term><option>-n</option></term>
+  <listitem>
+<para>Create an empty file.
+The size is noted, but disk blocks are not allocated
+until data is written to them.</para>
+  </listitem>
+  </varlistentry>
+  <varlistentry>
+  <term><option>-v</option></term>
+  <listitem>
+<para>Verbose.
+Report the names and sizes of created files.</para>
+
+  </listitem>
+  </varlistentry>
+</variablelist>
+</refsect1>
+
+<refsect1 id='see_also'><title>SEE ALSO</title>
+<para><citerefentry><refentrytitle>swapon</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
+<citerefentry><refentrytitle>swapon</refentrytitle><manvolnum>8</manvolnum></citerefentry>,</para>
+</refsect1>
+
+<refsect1 id='bugs'><title>BUGS</title>
+<para>Option
+<option>-n</option>
+is not tested well.</para>
+</refsect1>
+
+<refsect1 id='history'><title>HISTORY</title>
+<para>A command first appeared in SunOS.</para>
+</refsect1>
+</refentry>
diff --git a/src/mkfile b/src/mkfile
new file mode 100755
index 0000000..0c020ad
--- /dev/null
+++ b/src/mkfile
@@ -0,0 +1,81 @@
+#!/bin/bash
+# the original manpage is on
+# http://developer.apple.com/documentation/Darwin/Reference\
+# /ManPages/man8/mkfile.8.html
+# and
+# http://docs.sun.com/app/docs/doc/819-2240/6n4htdnbv?a=view
+SPARSE=0
+VERBOSE=0
+OPTFLAGS=""
+VERSION="1.0"
+COMMANDNAME="$0"
+
+function usage() {
+   cat - <<\EOF
+Usage: mkfile OPTION... SIZE FILE
+Create a new FILE of the specified size (possibly with sparse file) that is
+suitable for use as NFS-mounted swap areas, or as local swap areas.
+
+A FILE argument that does exist is overwritten.
+
+Mandatory arguments to long options are mandatory for short options too.
+  -n create a sparse file (the size is noted, but disk blocks are not
+      allocated until data is written to them)
+  -v be verbose (report the size of the file created)
+  -h display this help and exit
+
+SIZE is a number which may be followed by one of the following suffixes:
+KB 1000, K 1024, MB 1000*1000, M 1024*1024, and so on for G, T, P, E, Z, Y.
+
+SIZE may also be prefixed by one of the following modifying characters:
+`+' extend by, `-' reduce by, `<' at most, `>' at least,
+`/' round down to multiple of, `%' round up to multiple of.
+
+SEE ALSO
+swapon(8)
+
+HISTORY
+A command first appeared in SunOS.
+
+Report truncate bugs to address@hidden
+GNU coreutils home page: <http://www.gnu.org/software/coreutils/>
+General help using GNU software: <http://www.gnu.org/gethelp/>
+Report mkfile translation bugs to <http://translationproject.org/team/>
+EOF
+}
+
+while getopts ":vnh" OPTION ; do
+    case $OPTION in
+       v)
+          VERBOSE=1
+       ;;
+       n)
+          SPARSE=1
+       ;;
+       h)
+          usage
+          exit 0
+       ;;
+       *)
+          usage
+          exit 1
+       ;;
+   esac
+done
+
+if [ $SPARSE -eq 0 ] ; then
+   OPTFLAGS=$OPTFLAGS"-a "
+fi
+
+shift $(($OPTIND - 1))
+SIZE="$1"
+
+shift 1
+FILE="$1"
+
+truncate $OPTFLAGS $SIZE $FILE
+RET=$?
+
+if [ $RET -eq 0 ] &&Â [ $VERBOSE -eq 1 ] ; then
+   echo >&2 "Created file $FILE of the size "$(stat --format="%s" $FILE)"."
+fi
diff --git a/src/truncate.c b/src/truncate.c
index c6f12b7..6eaeac0 100644
--- a/src/truncate.c
+++ b/src/truncate.c
@@ -15,6 +15,7 @@
    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
 /* Written by Pádraig Brady
+   Extended to use posix_fallocate by Matěj Cepl <address@hidden>
 
    This is backwards compatible with the FreeBSD utility, but is more
    flexible wrt the size specifications and the use of long options,
@@ -50,10 +51,13 @@ static bool block_mode;
 /* (-r) Reference file to use size from */
 static char const *ref_file;
 
-static struct option const longopts[] =
-{
+/* (-a) Use fallocate to create a file */
+static bool fallocate_mode;
+
+static struct option const longopts[] = {
   {"no-create", no_argument, NULL, 'c'},
   {"io-blocks", no_argument, NULL, 'o'},
+  {"fallocate", no_argument, NULL, 'a'},
   {"reference", required_argument, NULL, 'r'},
   {"size", required_argument, NULL, 's'},
   {GETOPT_HELP_OPTION_DECL},
@@ -71,13 +75,12 @@ typedef enum
    This supports dd BLOCK size suffixes + lowercase g,t,m for bsd compat
    Note we don't support dd's b=512, c=1, w=2 or 21x512MiB formats.  */
 static int
-parse_len (char const *str, off_t *size)
+parse_len (char const *str, off_t * size)
 {
   enum strtol_error e;
   intmax_t tmp_size;
   e = xstrtoimax (str, NULL, 10, &tmp_size, "EgGkKmMPtTYZ0");
-  if (e == LONGINT_OK
-      && !(OFF_T_MIN <= tmp_size && tmp_size <= OFF_T_MAX))
+  if (e == LONGINT_OK && !(OFF_T_MIN <= tmp_size && tmp_size <= OFF_T_MAX))
     e = LONGINT_OVERFLOW;
 
   if (e == LONGINT_OK)
@@ -114,6 +117,9 @@ reads as zero bytes.\n\
 Mandatory arguments to long options are mandatory for short options too.\n\
 "), stdout);
       fputs (_("\
+  -a, --fallocate        when extending a file use fallocate.\n\
+"), stdout);
+      fputs (_("\
   -c, --no-create        do not create any files\n\
 "), stdout);
       fputs (_("\
@@ -161,8 +167,7 @@ do_ftruncate (int fd, char const *fname, off_t ssize, 
rel_mode_t rel_mode)
           error (0, 0,
                  _("overflow in %" PRIdMAX
                    " * %" PRIdMAX " byte blocks for file %s"),
-                 (intmax_t) ssize, (intmax_t) blksize,
-                 quote (fname));
+                 (intmax_t) ssize, (intmax_t) blksize, quote (fname));
           return 1;
         }
       ssize *= blksize;
@@ -210,7 +215,7 @@ do_ftruncate (int fd, char const *fname, off_t ssize, 
rel_mode_t rel_mode)
         }
       else
         {
-          if (ssize > OFF_T_MAX - (off_t)fsize)
+          if (ssize > OFF_T_MAX - (off_t) fsize)
             {
               error (0, 0, _("overflow extending size of file %s"),
                      quote (fname));
@@ -224,6 +229,20 @@ do_ftruncate (int fd, char const *fname, off_t ssize, 
rel_mode_t rel_mode)
   if (nsize < 0)
     nsize = 0;
 
+  /* posix_fallocate() is available since glibc 2.1.94.
+   * fallocate is in Linux since kernel 2.6.23.
+   */
+  if (fallocate_mode)
+    {
+      int ret = 0;
+      if ((ret = posix_fallocate (fd, 0, nsize)) != 0)
+        {
+          error (0, ret, _("cannot fallocate size %d for file %s"), nsize,
+                 quote (fname));
+          return 1;
+        }
+    }
+
   if (ftruncate (fd, nsize) == -1)      /* note updates mtime & ctime */
     {
       /* Complain only when ftruncate fails on a regular file, a
@@ -255,7 +274,7 @@ int
 main (int argc, char **argv)
 {
   bool got_size = false;
-  off_t size IF_LINT (= 0);
+  off_t size IF_LINT ( = 0);
   rel_mode_t rel_mode = rm_abs;
   mode_t omode;
   int c, errors = 0, fd = -1, oflags;
@@ -269,10 +288,14 @@ main (int argc, char **argv)
 
   atexit (close_stdout);
 
-  while ((c = getopt_long (argc, argv, "cor:s:", longopts, NULL)) != -1)
+  while ((c = getopt_long (argc, argv, "acor:s:", longopts, NULL)) != -1)
     {
       switch (c)
         {
+        case 'a':
+          fallocate_mode = true;
+          break;
+
         case 'c':
           no_create = true;
           break;
@@ -330,9 +353,9 @@ main (int argc, char **argv)
           got_size = true;
           break;
 
-        case_GETOPT_HELP_CHAR;
+          case_GETOPT_HELP_CHAR;
 
-        case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
+          case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
 
         default:
           usage (EXIT_FAILURE);
@@ -402,7 +425,6 @@ main (int argc, char **argv)
           continue;
         }
 
-
       if (fd != -1)
         {
           errors += do_ftruncate (fd, fname, size, rel_mode);
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 07e9473..d6e6426 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -231,6 +231,7 @@ TESTS =                                             \
   misc/truncate-overflow                       \
   misc/truncate-parameters                     \
   misc/truncate-relative                       \
+  misc/truncate-fallocate                      \
   misc/tsort                                   \
   misc/tty-eof                                 \
   misc/unexpand                                        \
diff --git a/tests/misc/truncate-fallocate b/tests/misc/truncate-fallocate
new file mode 100755
index 0000000..bce4083
--- /dev/null
+++ b/tests/misc/truncate-fallocate
@@ -0,0 +1,57 @@
+#!/bin/sh
+
+# Copyright (C) 2008 Free Software Foundation, Inc.
+# Written by Matěj Cepl <address@hidden>
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+export LANG=C
+TESTSIZE=200k
+TESTFILE=testfile
+
+if test "$VERBOSE" = yes; then
+  set -x
+  truncate --version
+fi
+
+. $srcdir/lang-default
+. $srcdir/test-lib.sh
+skip_if_root_
+
+trap EXIT rm -f $TESTFILE
+
+fail=0
+
+[ -f $TESTFILE ] && rm -f $TESTFILE
+truncate -a -s $TESTSIZE $TESTFILE || fail=1
+
+if [ ! $fail -eq 1 ] ; then
+       size=$(stat --format="%s" $TESTFILE)
+       if [ "$(($size - 204800))" -gt 1024 ] ; then
+               echo "Cannot create file $TESTFILE of $TESTSIZE size."
+               fail=1
+       fi
+fi
+
+[ -f $TESTFILE ] && rm -f $TESTFILE
+if [ ! $fail -eq 1 ] ; then
+       truncate -a $TESTFILE || fail=1
+fi
+
+[ -f $TESTFILE ] && rm -f $TESTFILE
+if [ ! $fail -eq 1 ] ; then
+       truncate -s || fail=1
+fi
+
+Exit $fail
diff --git a/tests/misc/truncate-mkfile b/tests/misc/truncate-mkfile
new file mode 100755
index 0000000..90531a6
--- /dev/null
+++ b/tests/misc/truncate-mkfile
@@ -0,0 +1,72 @@
+#!/bin/sh
+# make sure truncate gives reasonable diagnostics
+
+# Copyright (C) 2008 Free Software Foundation, Inc.
+# Written by Matěj Cepl <address@hidden>
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+export LANG=C
+TESTSIZE=200k
+TESTFILE=testfile
+
+if test "$VERBOSE" = yes; then
+  set -x
+  truncate --version
+fi
+
+. $srcdir/lang-default
+. $srcdir/test-lib.sh
+skip_if_root_
+
+trap EXIT rm -f $TESTFILE
+
+fail=0
+
+[ -f $TESTFILE ] && rm -f $TESTFILE
+mkfile $TESTSIZE $TESTFILE || fail=1
+
+if [ ! $fail -eq 1 ] ; then
+       size=$(stat --format="%s" $TESTFILE)
+       if [ "$(($size - 204800))" -gt 1024 ] ; then
+               echo "Cannot create file $TESTFILE of $TESTSIZE size."
+               fail=1
+       fi
+fi
+
+# Sparse file creation
+[ -f $TESTFILE ] && rm -f $TESTFILE
+mkfile -n $TESTSIZE $TESTFILE || fail=1
+
+if [ ! $fail -eq 1 ] ; then
+       size=$(stat --format="%s" $TESTFILE)
+       blocks=$(stat --format="%s" $TESTFILE)
+       if [ "$(($size - 204800))" -gt 1024 ] ; then
+               echo "Cannot create file $TESTFILE of $TESTSIZE size."
+               fail=1
+       fi
+fi
+
+# Non-sensical option
+[ -f $TESTFILE ] && rm -f $TESTFILE
+if [ ! $fail -eq 1 ] ; then
+       truncate -s $TESTFILE && fail=1
+fi
+
+[ -f $TESTFILE ] && rm -f $TESTFILE
+if [ ! $fail -eq 1 ] ; then
+       truncate -s || fail=1
+fi
+
+Exit $fail
-- 
1.6.0.6