Date:	Mon, 06 Jun 2011 16:34:29 -0700
From:	Allison Henderson <achender@...t.ibm.com>
To:	linux-fsdevel <linux-fsdevel@...r.kernel.org>,
	Ext4 Developers List <linux-ext4@...r.kernel.org>,
	xfs-oss <xfs@....sgi.com>
Subject: [PATCH 3/3 v5] XFS TESTS: Add ENOSPC Hole Punch Test

This patch adds a test to 252 that tests that a hole can be punched even when the
disk is full.  Reserved blocks should be used to allow a punch hole to proceed even
when there is not enough blocks to further fragment the file. To test this, the
file system is fragmented by punching holes in regular intervals and filling
the file system between punches. This will eventually force the file system to use
reserved blocks to proceed with the punch hole operation.

Signed-off-by: Allison Henderson <achender@...ibm.com>
---
:100755 100755 5efa243... b5204fe... M	252
:100644 100644 ddf63b0... fc6123c... M	common.punch
 252          |   12 +++++++
 common.punch |   95 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 107 insertions(+), 0 deletions(-)

diff --git a/252 b/252
index 5efa243..b5204fe 100755
--- a/252
+++ b/252
@@ -49,6 +49,7 @@ _supported_os Linux
 
 _require_xfs_io_falloc_punch
 _require_xfs_io_fiemap
+_require_scratch
 
 testfile=$TEST_DIR/252.$$
 
@@ -64,4 +65,15 @@ _test_generic_punch -k falloc fpunch fpunch fiemap _filter_fiemap $testfile -F
 # Delayed allocation multi punch hole tests
 _test_generic_punch -d -k falloc fpunch fpunch fiemap _filter_fiemap $testfile -F
 
+# Test full filesystem hole punching.
+# Make a small file system to fill
+umount $SCRATCH_DEV &> /dev/null
+_scratch_mkfs_sized $(( 1024 * 1024 * 1024 )) &> /dev/null
+_scratch_mount
+# Test must be able to write files with non-root permissions
+chmod 777 $SCRATCH_MNT
+
+block_size=`stat -f $SCRATCH_DEV | grep "Block size" | cut -d " " -f3`
+_test_full_fs_punch $(( $block_size * 2 )) $block_size 500 $SCRATCH_MNT/252.$$
+
 status=0 ; exit
diff --git a/common.punch b/common.punch
index ddf63b0..fc6123c 100644
--- a/common.punch
+++ b/common.punch
@@ -481,5 +481,100 @@ _test_generic_punch()
 		-c "$zero_cmd 128 128" \
 		-c "$map_cmd -v" $testfile | $filter_cmd
 	[ $? -ne 0 ] && die_now
+}
+
+# _fill_fs()
+#
+# Fills a file system by repeatedly creating files in the given folder
+# starting with the given file size.  Files are reduced in size when
+# they can no longer fit untill no more files can be created.
+#
+# This routine is used by _test_full_fs_punch to test that a hole may
+# still be punched when the disk is full by borrowing reserved blocks.
+# All files are created as a non root user to prevent reserved blocks
+# from being consumed.
+#
+_fill_fs() {
+	local file_size=$1
+	local dir=$2
+	local file_count=1
+
+	if [ $# -ne 2 ]
+	then
+	    echo "USAGE: $0 filesize dir"
+	    exit 1
+	fi
+
+	mkdir -p $dir &> /dev/null
+	if [[ $? != 0 ]] ; then
+		return 0
+	fi
+	chmod 777 $dir
+
+	rc=0
+	while [ $file_size -gt 0 -a $rc == 0 ]
+	do
+		# This part must not be done as root or
+		# reserved blocks will be consumed
+		sudo -u nobody $XFS_IO_PROG -F -f -c "pwrite  0 $file_size" $dir/$file_count.bin &> /dev/null
+		rc=$?
+
+		# If there was no room to make the file,
+		# and the file size can still be made smaller,
+		# then divide it in half, and keep going
+		if [ $file_size -gt 1 -a $rc != 0 ]
+		then
+			file_size=$(( $file_size / 2 ))
+			rc=0
+		fi
+		file_count=$(( $file_count + 1 ))
+
+	done
+}
 
+# _test_full_fs_punch()
+#
+# This function will test that a hole may be punched
+# even when the file system is full.  Reserved blocks
+# should be used to allow a punch hole to proceed even
+# when there is not enough blocks to further fragment the
+# file. To test this, this function will fragment the file
+# system by punching holes in regular intervals and filling
+# the file system between punches. 
+#
+_test_full_fs_punch()
+{
+	hole_len=$1      # The length of the holes to punch
+	hole_interval=$2 # The interval between the holes
+	iterations=$3    # The number of holes to punch
+	file_name=$4     # File to punch holes in
+	file_len=$(( $(( $hole_len + $hole_interval )) * $iterations ))
+	path=`dirname $file_name`
+	hole_offset=0
+
+	rm -f $file_name &> /dev/null
+
+	$XFS_IO_PROG -F -f -c "pwrite 0 $file_len" \
+		-c "fsync" $file_name &> /dev/null
+	chmod 666 $file_name
+
+	_fill_fs $(( 1024 * 1024 * 1024 )) $path/fill
+
+	for (( i=0; i<$iterations; i++ ))
+	do
+		# This part must not be done as root in order to
+		# test that reserved blocks are used when needed
+		sudo -u nobody $XFS_IO_PROG -F -f -c "fpunch $hole_offset $hole_len" $file_name 
+		rc=$?
+		if [[ $? != 0 ]] ; then
+			echo Punch hole failed
+			break
+		fi
+
+		hole_offset=$(( $hole_offset + $hole_len + $hole_interval ))
+
+		_fill_fs $hole_len $path/fill.$i
+
+	done
 }
+
-- 
1.7.1

--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Powered by blists - more mailing lists