275: add a write and reserve test

This test is for write-posix test. If writing a file when the disk is almost
full, the posix wants the call to write as much as possible but not none.

quote the POSIX:
If a write() requests that more bytes be written than there is room for
(for example, [XSI] [Option Start] the process' file size limit or
[Option End] the physical end of a medium), only as many bytes as there
is room for shall be written. For example, suppose there is space for 20
bytes more in a file before reaching a limit. A write of 512 bytes will
return 20. The next write of a non-zero number of bytes would give a
failure return (except as noted below).

Signed-off-by: Wu Bo <Wu.Bo@cn.fujitsu.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

275

@@ -0,0 +1,89 @@
+#! /bin/bash
+# FS QA Test No. 275
+#
+# The posix write test. when write size is larger than disk free size,
+# should write as more as possible
+#
+#-----------------------------------------------------------------------
+# Copyright (c) 2011-2012 Fujitsu, Inc.  All Rights Reserved.
+#
+# 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.
+#
+# This program is distributed in the hope that it would 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, write the Free Software Foundation,
+# Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+#
+#-----------------------------------------------------------------------
+#
+#creator
+owner=wu.bo@cn.fujitsu.com
+
+seq=`basename $0`
+echo "QA output created by $seq"
+
+here=`pwd`
+tmp=/tmp/$$
+status=0    # success is the default!
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+_cleanup()
+{
+	cd /
+	rm -f $SCRATCH_MNT/* $tmp.*
+	_scratch_unmount
+}
+
+. ./common.rc
+. ./common.filter
+
+# real QA test starts here
+_supported_fs generic
+_supported_os IRIX Linux
+_require_scratch
+
+echo "------------------------------"
+echo "write lack test"
+echo "------------------------------"
+
+rm -f $seq.full
+
+umount $SCRATCH_DEV 2>/dev/null
+_scratch_mkfs_sized $((1 * 1024 * 1024 * 1024)) >>$seq.full 2>&1
+_scratch_mount
+
+rm -rf $SCRATCH_MNT/*
+cd $SCRATCH_MNT
+
+dd if=/dev/zero of=tmp1 bs=4K count=1 >/dev/null 2>&1
+if [ $? -ne 0 ]
+then
+	echo "create file err"
+	status=1
+	exit
+fi
+
+dd if=/dev/zero of=tmp2 bs=1M >/dev/null 2>&1
+dd if=/dev/zero of=tmp3 bs=4K >/dev/null 2>&1
+sync
+
+rm -f tmp1
+sync
+
+dd if=/dev/zero of=tmp1 bs=8K count=1 >/dev/null 2>&1
+_filesize=`du tmp1 | awk '{print $1}'`
+if [ $_filesize -ne 4 ]
+then
+	echo "write file err"
+	status=1
+	exit
+fi
+
+echo "done"
+exit