qemu/tests/qemu-iotests/308
Max Reitz f29add26d4 iotests/308: Test +w on read-only FUSE exports
Test that +w on read-only FUSE exports returns an EROFS error.  u+x on
the other hand should work.  (There is no special reason to choose u+x
here, it simply is like +w another flag that is not set by default.)

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20210625142317.271673-6-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-07-09 12:26:05 +02:00

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#!/usr/bin/env bash
# group: rw
#
# Test FUSE exports (in ways that are not captured by the generic
# tests)
#
# Copyright (C) 2020 Red Hat, Inc.
#
# 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 2 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/>.
#
seq=$(basename "$0")
echo "QA output created by $seq"
status=1 # failure is the default!
_cleanup()
{
_cleanup_qemu
_cleanup_test_img
rmdir "$EXT_MP" 2>/dev/null
rm -f "$EXT_MP"
rm -f "$COPIED_IMG"
}
trap "_cleanup; exit \$status" 0 1 2 3 15
# get standard environment, filters and checks
. ./common.rc
. ./common.filter
. ./common.qemu
# Generic format, but needs a plain filename
_supported_fmt generic
if [ "$IMGOPTSSYNTAX" = "true" ]; then
_unsupported_fmt $IMGFMT
fi
# We need the image to have exactly the specified size, and VPC does
# not allow that by default
_unsupported_fmt vpc
_supported_proto file # We create the FUSE export manually
_supported_os Linux # We need /dev/urandom
# $1: Export ID
# $2: Options (beyond the node-name and ID)
# $3: Expected return value (defaults to 'return')
# $4: Node to export (defaults to 'node-format')
fuse_export_add()
{
# The grep -v is a filter for errors when /etc/fuse.conf does not contain
# user_allow_other. (The error is benign, but it is printed by fusermount
# on the first mount attempt, so our export code cannot hide it.)
_send_qemu_cmd $QEMU_HANDLE \
"{'execute': 'block-export-add',
'arguments': {
'type': 'fuse',
'id': '$1',
'node-name': '${4:-node-format}',
$2
} }" \
"${3:-return}" \
| _filter_imgfmt \
| grep -v 'option allow_other only allowed if'
}
# $1: Export ID
fuse_export_del()
{
_send_qemu_cmd $QEMU_HANDLE \
"{'execute': 'block-export-del',
'arguments': {
'id': '$1'
} }" \
'return'
_send_qemu_cmd $QEMU_HANDLE \
'' \
'BLOCK_EXPORT_DELETED'
}
# Return the length of the protocol file
# $1: Protocol node export mount point
# $2: Original file (to compare)
get_proto_len()
{
len1=$(stat -c '%s' "$1")
len2=$(stat -c '%s' "$2")
if [ "$len1" != "$len2" ]; then
echo 'ERROR: Length of export and original differ:' >&2
echo "$len1 != $len2" >&2
else
echo '(OK: Lengths of export and original are the same)' >&2
fi
echo "$len1"
}
COPIED_IMG="$TEST_IMG.copy"
EXT_MP="$TEST_IMG.fuse"
echo '=== Set up ==='
# Create image with random data
_make_test_img 64M
$QEMU_IO -c 'write -s /dev/urandom 0 64M' "$TEST_IMG" | _filter_qemu_io
_launch_qemu
_send_qemu_cmd $QEMU_HANDLE \
"{'execute': 'qmp_capabilities'}" \
'return'
# Separate blockdev-add calls for format and protocol so we can remove
# the format layer later on
_send_qemu_cmd $QEMU_HANDLE \
"{'execute': 'blockdev-add',
'arguments': {
'driver': 'file',
'node-name': 'node-protocol',
'filename': '$TEST_IMG'
} }" \
'return'
_send_qemu_cmd $QEMU_HANDLE \
"{'execute': 'blockdev-add',
'arguments': {
'driver': '$IMGFMT',
'node-name': 'node-format',
'file': 'node-protocol'
} }" \
'return'
echo
echo '=== Mountpoint not present ==='
rmdir "$EXT_MP" 2>/dev/null
rm -f "$EXT_MP"
output=$(fuse_export_add 'export-err' "'mountpoint': '$EXT_MP'" error)
if echo "$output" | grep -q "Invalid parameter 'fuse'"; then
_notrun 'No FUSE support'
fi
echo "$output"
echo
echo '=== Mountpoint is a directory ==='
mkdir "$EXT_MP"
fuse_export_add 'export-err' "'mountpoint': '$EXT_MP'" error
rmdir "$EXT_MP"
echo
echo '=== Mountpoint is a regular file ==='
touch "$EXT_MP"
fuse_export_add 'export-mp' "'mountpoint': '$EXT_MP'"
# Check that the export presents the same data as the original image
$QEMU_IMG compare -f raw -F $IMGFMT -U "$EXT_MP" "$TEST_IMG"
# Some quick chmod tests
stat -c 'Permissions pre-chmod: %a' "$EXT_MP"
# Verify that we cannot set +w
chmod u+w "$EXT_MP" 2>&1 | _filter_testdir | _filter_imgfmt
stat -c 'Permissions post-+w: %a' "$EXT_MP"
# But that we can set, say, +x (if we are so inclined)
chmod u+x "$EXT_MP" 2>&1 | _filter_testdir | _filter_imgfmt
stat -c 'Permissions post-+x: %a' "$EXT_MP"
echo
echo '=== Mount over existing file ==='
# This is the coolest feature of FUSE exports: You can transparently
# make images in any format appear as raw images
fuse_export_add 'export-img' "'mountpoint': '$TEST_IMG'"
# Accesses both exports at the same time, so we get a concurrency test
$QEMU_IMG compare -f raw -F raw -U "$EXT_MP" "$TEST_IMG"
# Just to be sure, we later want to compare the data offline. Also,
# this allows us to see that cp works without complaining.
# (This is not a given, because cp will expect a short read at EOF.
# Internally, qemu does not allow short reads, so we have to check
# whether the FUSE export driver lets them work.)
cp "$TEST_IMG" "$COPIED_IMG"
# $TEST_IMG will be in mode 0400 because it is read-only; we are going
# to write to the copy, so make it writable
chmod 0600 "$COPIED_IMG"
echo
echo '=== Double export ==='
# We have already seen that exporting a node twice works fine, but you
# cannot export anything twice on the same mount point. The reason is
# that qemu has to stat the given mount point, and this would have to
# be answered by the same qemu instance if it already has an export
# there. However, it cannot answer the stat because it is itself
# caught up in that same stat.
fuse_export_add 'export-err' "'mountpoint': '$EXT_MP'" error
echo
echo '=== Remove export ==='
# Double-check that $EXT_MP appears as a non-empty file (the raw image)
$QEMU_IMG info -f raw "$EXT_MP" | grep 'virtual size'
fuse_export_del 'export-mp'
# See that the file appears empty again
$QEMU_IMG info -f raw "$EXT_MP" | grep 'virtual size'
echo
echo '=== Writable export ==='
fuse_export_add 'export-mp' "'mountpoint': '$EXT_MP', 'writable': true"
# Check that writing to the read-only export fails
$QEMU_IO -f raw -c 'write -P 42 1M 64k' "$TEST_IMG" 2>&1 \
| _filter_qemu_io | _filter_testdir | _filter_imgfmt
# But here it should work
$QEMU_IO -f raw -c 'write -P 42 1M 64k' "$EXT_MP" | _filter_qemu_io
# (Adjust the copy, too)
$QEMU_IO -f raw -c 'write -P 42 1M 64k' "$COPIED_IMG" | _filter_qemu_io
echo
echo '=== Resizing exports ==='
# Here, we need to export the protocol node -- the format layer may
# not be growable, simply because the format does not support it.
# Remove all exports and the format node first so permissions will not
# get in the way
fuse_export_del 'export-mp'
fuse_export_del 'export-img'
_send_qemu_cmd $QEMU_HANDLE \
"{'execute': 'blockdev-del',
'arguments': {
'node-name': 'node-format'
} }" \
'return'
# Now export the protocol node
fuse_export_add \
'export-mp' \
"'mountpoint': '$EXT_MP', 'writable': true" \
'return' \
'node-protocol'
echo
echo '--- Try growing non-growable export ---'
# Get the current size so we can write beyond the EOF
orig_len=$(get_proto_len "$EXT_MP" "$TEST_IMG")
orig_disk_usage=$(stat -c '%b' "$TEST_IMG")
# Should fail (exports are non-growable by default)
# (Note that qemu-io can never write beyond the EOF, so we have to use
# dd here)
dd if=/dev/zero of="$EXT_MP" bs=1 count=64k seek=$orig_len 2>&1 \
| _filter_testdir | _filter_imgfmt
echo
echo '--- Resize export ---'
# But we can truncate it explicitly; even with fallocate
fallocate -o "$orig_len" -l 64k "$EXT_MP"
new_len=$(get_proto_len "$EXT_MP" "$TEST_IMG")
if [ "$new_len" != "$((orig_len + 65536))" ]; then
echo 'ERROR: Unexpected post-truncate image size:'
echo "$new_len != $((orig_len + 65536))"
else
echo 'OK: Post-truncate image size is as expected'
fi
new_disk_usage=$(stat -c '%b' "$TEST_IMG")
if [ "$new_disk_usage" -gt "$orig_disk_usage" ]; then
echo 'OK: Disk usage grew with fallocate'
else
echo 'ERROR: Disk usage did not grow despite fallocate:'
echo "$orig_disk_usage => $new_disk_usage"
fi
echo
echo '--- Try growing growable export ---'
# Now export as growable
fuse_export_del 'export-mp'
fuse_export_add \
'export-mp' \
"'mountpoint': '$EXT_MP', 'writable': true, 'growable': true" \
'return' \
'node-protocol'
# Now we should be able to write beyond the EOF
dd if=/dev/zero of="$EXT_MP" bs=1 count=64k seek=$new_len 2>&1 \
| _filter_testdir | _filter_imgfmt
new_len=$(get_proto_len "$EXT_MP" "$TEST_IMG")
if [ "$new_len" != "$((orig_len + 131072))" ]; then
echo 'ERROR: Unexpected post-grow image size:'
echo "$new_len != $((orig_len + 131072))"
else
echo 'OK: Post-grow image size is as expected'
fi
echo
echo '--- Shrink export ---'
# Now go back to the original size
truncate -s "$orig_len" "$EXT_MP"
new_len=$(get_proto_len "$EXT_MP" "$TEST_IMG")
if [ "$new_len" != "$orig_len" ]; then
echo 'ERROR: Unexpected post-truncate image size:'
echo "$new_len != $orig_len"
else
echo 'OK: Post-truncate image size is as expected'
fi
echo
echo '=== Tear down ==='
_send_qemu_cmd $QEMU_HANDLE \
"{'execute': 'quit'}" \
'return'
wait=yes _cleanup_qemu
echo
echo '=== Compare copy with original ==='
$QEMU_IMG compare -f raw -F $IMGFMT "$COPIED_IMG" "$TEST_IMG"
# success, all done
echo "*** done"
rm -f $seq.full
status=0