mirrors/libguestfs
1
0
Fork 0
mirror of https://github.com/libguestfs/libguestfs.git synced 2026-03-21 22:53:37 +00:00
Code Issues Packages Projects Releases Wiki Activity

daemon: btrfs: Simplify snapshot code and fix invalid memory access

Browse Source 
The existing code had a bug which you can demonstrate by doing:

  $ guestfish -N fs:btrfs:10G -m /dev/sda1 \
  btrfs-subvolume-create /sub :
  btrfs-subvolume-snapshot /sub /snap1 : \
  btrfs-subvolume-snapshot /sub /snap123 : \
  btrfs-subvolume-snapshot /sub /snap123456 : \
  btrfs-subvolume-show /sub
  ...
  libguestfs: error: appliance closed the connection unexpectedly.
  This usually means the libguestfs appliance crashed.

As the code for parsing the output and creating the comma-separated
list of snapshots was unncessarily complicated in the first place,
simplify it.  This also fixes the bug.

This also adds a regression test.

Thanks: Arye Yurkovsky
Link: https://lists.libguestfs.org/archives/list/guestfs@lists.libguestfs.org/thread/QV5VDHIH7WRUNAE54K6OEOKJMWL6M7EM/
This commit is contained in:
Richard W.M. Jones
2025-11-21 17:19:29 +00:00
committed by rwmjones
parent 6c8e3992fc
commit 56da6b36d3
3 changed files with 82 additions and 22 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
tests/Makefile.am
View File

@@ -50,12 +50,14 @@ TESTS += \
btrfs/test-btrfs-misc.pl \
btrfs/test-btrfs-devices.sh \
btrfs/test-btrfs-subvolume-default.pl \
btrfs/test-btrfs-replace.sh
btrfs/test-btrfs-replace.sh \
btrfs/test-btrfs-subvolume-snapshot.sh
EXTRA_DIST += \
btrfs/test-btrfs-misc.pl \
btrfs/test-btrfs-devices.sh \
btrfs/test-btrfs-subvolume-default.pl \
btrfs/test-btrfs-replace.sh
btrfs/test-btrfs-replace.sh \
btrfs/test-btrfs-subvolume-snapshot.sh
CLEANFILES += \
c-api/test.log \

67
tests/btrfs/test-btrfs-subvolume-snapshot.sh Executable file
View File

@@ -0,0 +1,67 @@
#!/bin/bash -
# libguestfs
# Copyright Red Hat
#
# 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, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
# Test btrfs subvolumes and snapshots.
source ./functions.sh
set -e
set -x
skip_if_skipped
skip_unless_feature_available btrfs
guestfish <<'EOF'
# Create a large empty disk.
sparse test-btrfs-subvolume-snapshot.img 10G
run
mkfs btrfs /dev/sda
mount /dev/sda /
# Create some subvolumes.
btrfs-subvolume-create /sub0
btrfs-subvolume-create /sub1
btrfs-subvolume-create /sub3
# Create a few snapshots.
btrfs-subvolume-snapshot /sub1 /snap11
btrfs-subvolume-snapshot /sub3 /snap31
btrfs-subvolume-snapshot /sub3 /snap3123
btrfs-subvolume-snapshot /sub3 /snap3123456123456
# List the subvolumes.
btrfs-subvolume-show /sub0
btrfs-subvolume-show /sub1
btrfs-subvolume-show /sub3
# Capture the list of snapshots.
btrfs-subvolume-show /sub0 | grep -F 'Snapshot(s):' > subvolume-snapshot.out
btrfs-subvolume-show /sub1 | grep -F 'Snapshot(s):' >> subvolume-snapshot.out
btrfs-subvolume-show /sub3 | grep -F 'Snapshot(s):' >> subvolume-snapshot.out
EOF
cat subvolume-snapshot.out
test "$(cat subvolume-snapshot.out)" = \
"Snapshot(s):
Snapshot(s): snap11
Snapshot(s): snap31,snap3123,snap3123456123456"
rm test-btrfs-subvolume-snapshot.img subvolume-snapshot.out