From e78ae6d16009263a8dfcd91ea8ce8fc08a077529 Mon Sep 17 00:00:00 2001 From: Eduardo Otubo Date: Tue, 28 Apr 2020 08:22:03 +0200 Subject: [PATCH 1/3] Do not use fallocate in swap file creation on xfs. (#70) RH-Author: Eduardo Otubo Message-id: <20200422130428.7663-2-otubo@redhat.com> Patchwork-id: 96031 O-Subject: [RHEL-7.7.z/RHEL-7.8.z cloud-init PATCH 1/3] Do not use fallocate in swap file creation on xfs. (#70) Bugzilla: 1801094 RH-Acked-by: Vitaly Kuznetsov RH-Acked-by: Cathy Avery commit 6603706eec1c39d9d591c8ffa0ef7171b74d84d6 Author: Eduardo Otubo Date: Thu Jan 23 17:41:48 2020 +0100 Do not use fallocate in swap file creation on xfs. (#70) When creating a swap file on an xfs filesystem, fallocate cannot be used. Doing so results in failure of swapon and a message like: swapon: swapfile has holes The solution here is to maintain a list (currently containing only XFS) of filesystems where fallocate cannot be used. The, on those fileystems use the slower but functional 'dd' method. Signed-off-by: Eduardo Otubo Co-authored-by: Adam Dobrawy Co-authored-by: Scott Moser Co-authored-by: Daniel Watkins LP: #1781781 Signed-off-bt: Eduardo Otubo Signed-off-by: Miroslav Rezanina --- cloudinit/config/cc_mounts.py | 67 ++++++++++++++++------ .../unittests/test_handler/test_handler_mounts.py | 12 ++++ 2 files changed, 62 insertions(+), 17 deletions(-) diff --git a/cloudinit/config/cc_mounts.py b/cloudinit/config/cc_mounts.py index 123ffb8..6884ddf 100644 --- a/cloudinit/config/cc_mounts.py +++ b/cloudinit/config/cc_mounts.py @@ -223,13 +223,58 @@ def suggested_swapsize(memsize=None, maxsize=None, fsys=None): return size +def create_swapfile(fname, size): + """Size is in MiB.""" + + errmsg = "Failed to create swapfile '%s' of size %dMB via %s: %s" + + def create_swap(fname, size, method): + LOG.debug("Creating swapfile in '%s' on fstype '%s' using '%s'", + fname, fstype, method) + + if method == "fallocate": + cmd = ['fallocate', '-l', '%dM' % size, fname] + elif method == "dd": + cmd = ['dd', 'if=/dev/zero', 'of=%s' % fname, 'bs=1M', + 'count=%d' % size] + + try: + util.subp(cmd, capture=True) + except util.ProcessExecutionError as e: + LOG.warning(errmsg, fname, size, method, e) + util.del_file(fname) + + swap_dir = os.path.dirname(fname) + util.ensure_dir(swap_dir) + + fstype = util.get_mount_info(swap_dir)[1] + + if fstype in ("xfs", "btrfs"): + create_swap(fname, size, "dd") + else: + try: + create_swap(fname, size, "fallocate") + except util.ProcessExecutionError as e: + LOG.warning(errmsg, fname, size, "dd", e) + LOG.warning("Will attempt with dd.") + create_swap(fname, size, "dd") + + util.chmod(fname, 0o600) + try: + util.subp(['mkswap', fname]) + except util.ProcessExecutionError: + util.del_file(fname) + raise + + def setup_swapfile(fname, size=None, maxsize=None): """ fname: full path string of filename to setup size: the size to create. set to "auto" for recommended maxsize: the maximum size """ - tdir = os.path.dirname(fname) + swap_dir = os.path.dirname(fname) + mibsize = str(int(size / (2 ** 20))) if str(size).lower() == "auto": try: memsize = util.read_meminfo()['total'] @@ -237,28 +282,16 @@ def setup_swapfile(fname, size=None, maxsize=None): LOG.debug("Not creating swap: failed to read meminfo") return - util.ensure_dir(tdir) - size = suggested_swapsize(fsys=tdir, maxsize=maxsize, + util.ensure_dir(swap_dir) + size = suggested_swapsize(fsys=swap_dir, maxsize=maxsize, memsize=memsize) if not size: LOG.debug("Not creating swap: suggested size was 0") return - mbsize = str(int(size / (2 ** 20))) - msg = "creating swap file '%s' of %sMB" % (fname, mbsize) - try: - util.ensure_dir(tdir) - util.log_time(LOG.debug, msg, func=util.subp, - args=[['sh', '-c', - ('rm -f "$1" && umask 0066 && ' - '{ fallocate -l "${2}M" "$1" || ' - ' dd if=/dev/zero "of=$1" bs=1M "count=$2"; } && ' - 'mkswap "$1" || { r=$?; rm -f "$1"; exit $r; }'), - 'setup_swap', fname, mbsize]]) - - except Exception as e: - raise IOError("Failed %s: %s" % (msg, e)) + util.log_time(LOG.debug, msg="Setting up swap file", func=create_swapfile, + args=[fname, mibsize]) return fname diff --git a/tests/unittests/test_handler/test_handler_mounts.py b/tests/unittests/test_handler/test_handler_mounts.py index 0fb160b..7bcefa0 100644 --- a/tests/unittests/test_handler/test_handler_mounts.py +++ b/tests/unittests/test_handler/test_handler_mounts.py @@ -181,6 +181,18 @@ class TestFstabHandling(test_helpers.FilesystemMockingTestCase): return dev + def test_swap_integrity(self): + '''Ensure that the swap file is correctly created and can + swapon successfully. Fixing the corner case of: + kernel: swapon: swapfile has holes''' + + fstab = '/swap.img swap swap defaults 0 0\n' + + with open(cc_mounts.FSTAB_PATH, 'w') as fd: + fd.write(fstab) + cc = {'swap': ['filename: /swap.img', 'size: 512', 'maxsize: 512']} + cc_mounts.handle(None, cc, self.mock_cloud, self.mock_log, []) + def test_fstab_no_swap_device(self): '''Ensure that cloud-init adds a discovered swap partition to /etc/fstab.''' -- 1.8.3.1