diff -up yum-3.4.3/yumcommands.py.orig yum-3.4.3/yumcommands.py

--- yum-3.4.3/yumcommands.py.orig	2016-07-21 11:39:40.422379800 +0200

+++ yum-3.4.3/yumcommands.py	2016-07-21 11:40:42.144992126 +0200

@@ -42,6 +42,7 @@ import errno

 import yum.config

 from yum import updateinfo

 from yum.packages import parsePackages

+from yum.fssnapshots import LibLVMError, lvmerr2str

 def _err_mini_usage(base, basecmd):

     if basecmd not in base.yum_cli_commands:

@@ -4266,12 +4267,19 @@ class FSSnapshotCommand(YumCommand):

             return 1, [basecmd + ' ' + subcommand + ' done']

         if subcommand == 'list':

-            snaps = base.fssnap.old_snapshots()

+            try:

+                snaps = base.fssnap.old_snapshots()

+            except LibLVMError as e:

+                return 1, [_("Failed to list snapshots: ") + lvmerr2str(e)]

             print _("List of %u snapshosts:") % len(snaps)

             self._li_snaps(base, snaps)

         if subcommand == 'delete':

-            snaps = base.fssnap.old_snapshots()

+            msg = _("Failed to delete snapshots: ")

+            try:

+                snaps = base.fssnap.old_snapshots()

+            except LibLVMError as e:

+                return 1, [msg + lvmerr2str(e)]

             devs = [x['dev'] for x in snaps]

             snaps = set()

             for dev in devs:

@@ -4282,13 +4290,20 @@ class FSSnapshotCommand(YumCommand):

                     if dev == extcmd or fnmatch.fnmatch(dev, extcmd):

                         snaps.add(dev)

                         break

-            snaps = base.fssnap.del_snapshots(devices=snaps)

+            try:

+                snaps = base.fssnap.del_snapshots(devices=snaps)

+            except LibLVMError as e:

+                return 1, [msg + lvmerr2str(e)]

             print _("Deleted %u snapshosts:") % len(snaps)

             self._li_snaps(base, snaps)

         if subcommand in ('have-space', 'has-space'):

             pc = base.conf.fssnap_percentage

-            if base.fssnap.has_space(pc):

+            try:

+                has_space = base.fssnap.has_space(pc)

+            except LibLVMError as e:

+                return 1, [_("Could not determine free space on logical volumes: ") + lvmerr2str(e)]

+            if has_space:

                 print _("Space available to take a snapshot.")

             else:

                 print _("Not enough space available on logical volumes to take a snapshot.")

@@ -4296,14 +4311,22 @@ class FSSnapshotCommand(YumCommand):

         if subcommand == 'create':

             tags = {'*': ['reason=manual']}

             pc = base.conf.fssnap_percentage

-            snaps = base.fssnap.snapshot(pc, tags=tags)

+            msg = _("Failed to create snapshots")

+            try:

+                snaps = base.fssnap.snapshot(pc, tags=tags)

+            except LibLVMError as e:

+                msg += ": " + lvmerr2str(e)

+                snaps = []

             if not snaps:

-                print _("Failed to create snapshots")

+                print msg

             for (odev, ndev) in snaps:

                 print _("Created snapshot from %s, results is: %s") %(odev,ndev)

         if subcommand == 'summary':

-            snaps = base.fssnap.old_snapshots()

+            try:

+                snaps = base.fssnap.old_snapshots()

+            except LibLVMError as e:

+                return 1, [_("Failed to list snapshots: ") + lvmerr2str(e)]

             if not snaps:

                 print _("No snapshots, LVM version:"), base.fssnap.version

                 return 0, [basecmd + ' ' + subcommand + ' done']

diff -up yum-3.4.3/yum/fssnapshots.py.orig yum-3.4.3/yum/fssnapshots.py

--- yum-3.4.3/yum/fssnapshots.py.orig	2016-07-21 11:39:40.351380246 +0200

+++ yum-3.4.3/yum/fssnapshots.py	2016-07-21 11:40:02.211242946 +0200

@@ -6,6 +6,7 @@ import time

 from datetime import datetime

 import subprocess

+from yum import _

 try:

     import lvm

@@ -24,6 +25,14 @@ except:

     lvm = None

     _ver = None

+if lvm is not None:

+    from lvm import LibLVMError

+    class _ResultError(LibLVMError):

+        """Exception raised for LVM calls resulting in bad return values."""

+        pass

+else:

+    LibLVMError = None

+

 def _is_origin(lv):

     snap = lv.getAttr()

@@ -53,14 +62,18 @@ def _vg_name2lv(vg, lvname):

         return None

 def _list_vg_names():

-    names = lvm.listVgNames()

+    try:

+        names = lvm.listVgNames()

+    except LibLVMError:

+        # Try to use the lvm binary instead

+        names = []

     if not names: # Could be just broken...

         p = subprocess.Popen(["/sbin/lvm", "vgs", "-o", "vg_name"],

                              stdout=subprocess.PIPE, stderr=subprocess.PIPE)

         err = p.wait()

         if err:

-            return [] # Meh.

+            raise _ResultError(_("Failed to obtain volume group names"))

         output = p.communicate()[0]

         output = output.split('\n')

@@ -132,6 +145,25 @@ def _lv_data(vg, lv):

     return data

+def _log_traceback(func):

+    """Decorator for _FSSnap methods that logs LVM tracebacks."""

+    def wrap(self, *args, **kwargs):

+        try:

+            return func(self, *args, **kwargs)

+        except LibLVMError as e:

+            if self._logger is not None:

+                self._logger.exception(e)

+            raise

+    return wrap

+

+def lvmerr2str(exc):

+    """Convert a LibLVMError instance to a readable error message."""

+    if type(exc) == LibLVMError and len(exc.args) == 2:

+        # args[0] is the error number so ignore that

+        return exc.args[1]

+    else:

+        return str(exc)

+

 class _FSSnap(object):

@@ -139,7 +171,7 @@ class _FSSnap(object):

     # New style is: fedora/root fedora/swap

     # New style is: redhat/root redhat/swap

     def __init__(self, root="/", lookup_mounts=True,

-                 devices=('!*/swap', '!*/lv_swap')):

+                 devices=('!*/swap', '!*/lv_swap'), logger=None):

         if not lvm or os.geteuid():

             devices = []

@@ -150,12 +182,18 @@ class _FSSnap(object):

         self._postfix = None

         self._root = root

         self._devs = devices

-        self._vgnames = []

+        self._vgname_list = None

+        # Logger object to be used for LVM traceback logging

+        self._logger = logger

         if not self._devs:

             return

-        self._vgnames = _list_vg_names() if self.available else []

+    @property

+    def _vgnames(self):

+        if self._vgname_list is None:

+            self._vgname_list = _list_vg_names() if self.available else []

+        return self._vgname_list

     def _use_dev(self, vgname, lv=None):

@@ -196,6 +234,7 @@ class _FSSnap(object):

         return found_neg

+    @_log_traceback

     def has_space(self, percentage=100):

         """ See if we have enough space to try a snapshot. """

@@ -207,7 +246,8 @@ class _FSSnap(object):

             vg = lvm.vgOpen(vgname, 'r')

             if not vg:

-                return False

+                raise _ResultError(

+                    _("Unknown error when opening volume group ") + vgname)

             vgfsize = vg.getFreeSize()

             lvssize = 0

@@ -230,6 +270,7 @@ class _FSSnap(object):

         return ret

+    @_log_traceback

     def snapshot(self, percentage=100, prefix='', postfix=None, tags={}):

         """ Attempt to take a snapshot, note that errors can happen after

             this function succeeds. """

@@ -245,7 +286,8 @@ class _FSSnap(object):

             vg = lvm.vgOpen(vgname, 'w')

             if not vg:

-                return False

+                raise _ResultError(

+                    _("Unknown error when opening volume group ") + vgname)

             for lv in vg.listLVs():

                 lvname = lv.getName()

@@ -257,7 +299,8 @@ class _FSSnap(object):

                 nlv = lv.snapshot(nlvname, (lv.getSize() * percentage) / 100)

                 if not nlv: # Failed here ... continuing seems bad.

                     vg.close()

-                    return None

+                    raise _ResultError(

+                        _("Unknown error when creating snapshot ") + nlvname)

                 odev = "%s/%s" % (vgname,  lvname)

                 ndev = "%s/%s" % (vgname, nlvname)

@@ -280,6 +323,7 @@ class _FSSnap(object):

         return ret

+    @_log_traceback

     def old_snapshots(self):

         """ List data for old snapshots. """

@@ -289,6 +333,9 @@ class _FSSnap(object):

             # see stuff after changing config. options.

             vg = lvm.vgOpen(vgname, 'w')

+            if not vg:

+                raise _ResultError(

+                    _("Unknown error when opening volume group ") + vgname)

             for lv in vg.listLVs():

@@ -300,6 +347,7 @@ class _FSSnap(object):

         return ret

+    @_log_traceback

     def del_snapshots(self, devices=[]):

         """ Remove snapshots. """

@@ -318,6 +366,9 @@ class _FSSnap(object):

         for vgname in togo:

             vg = lvm.vgOpen(vgname, 'w')

+            if not vg:

+                raise _ResultError(

+                    _("Unknown error when opening volume group ") + vgname)

             for lvname in togo[vgname]:

                 lv = _vg_name2lv(vg, lvname)

diff -up yum-3.4.3/yum/__init__.py.orig yum-3.4.3/yum/__init__.py

--- yum-3.4.3/yum/__init__.py.orig	2016-07-21 11:39:40.425379782 +0200

+++ yum-3.4.3/yum/__init__.py	2016-07-21 11:40:02.211242946 +0200

@@ -81,6 +81,7 @@ import yumRepo

 import callbacks

 import yum.history

 import yum.fssnapshots

+from yum.fssnapshots import LibLVMError, lvmerr2str

 import yum.igroups

 import update_md

@@ -204,6 +205,7 @@ class YumBase(depsolve.Depsolve):

         self._not_found_i = {}

         self.logger = logging.getLogger("yum.YumBase")

         self.verbose_logger = logging.getLogger("yum.verbose.YumBase")

+        self.file_logger = logging.getLogger("yum.filelogging.YumBase")

         self._override_sigchecks = False

         self._repos = RepoStorage(self)

         self.repo_setopts = {} # since we have to use repo_setopts in base and 

@@ -1048,7 +1050,8 @@ class YumBase(depsolve.Depsolve):

         if self._fssnap is None:

             devices = self.conf.fssnap_devices

             self._fssnap = yum.fssnapshots._FSSnap(root=self.conf.installroot,

-                                                   devices=devices)

+                                                   devices=devices,

+                                                   logger=self.file_logger)

         return self._fssnap

@@ -1726,6 +1729,37 @@ much more problems).

         :raises: :class:`yum.Errors.YumRPMTransError` if there is a

            transaction cannot be completed

         """

+

+        def create_snapshot(post=False):

+            """Create the pre or post trans snapshot if we have free space."""

+            msg = _("Not enough space on logical volumes to create %s FS snapshot." %

+                    ("post trans" if post else "pre."))

+            try:

+                has_space = self.fssnap.has_space(self.conf.fssnap_percentage)

+            except LibLVMError as e:

+                msg = _("Could not determine free space on logical volumes: ") + lvmerr2str(e)

+                has_space = False

+            if not has_space:

+                if not post and self.conf.fssnap_abort_on_errors in ('snapshot-failure', 'any'):

+                    raise Errors.YumRPMTransError(msg="Aborting transaction", errors=msg)

+                else:

+                    self.verbose_logger.critical(msg)

+            else:

+                tags = {'*': ['reason=automatic']} # FIXME: pre. and post tags

+                msg = _("Failed to create snapshot")

+                try:

+                    snaps = self.fssnap.snapshot(self.conf.fssnap_percentage, tags=tags)

+                except LibLVMError as e:

+                    msg += ": " + lvmerr2str(e)

+                    snaps = []

+                if not snaps:

+                    if not post and self.conf.fssnap_abort_on_errors in ('snapshot-failure', 'any'):

+                        raise Errors.YumRPMTransError(msg="Aborting transaction", errors=msg)

+                    else:

+                        self.verbose_logger.critical(msg)

+                for (odev, ndev) in snaps:

+                    self.verbose_logger.info(_("Created snapshot from %s, results is: %s") % (odev, ndev))

+

         if (self.conf.fssnap_automatic_pre or self.conf.fssnap_automatic_post) and not self.fssnap.available:

             msg = _("Snapshot support not available.")

             if self.conf.fssnap_abort_on_errors in ('broken-setup', 'any'):

@@ -1737,7 +1771,13 @@ much more problems).

                                        self.conf.fssnap_automatic_post) and

                                       self.conf.fssnap_automatic_keep):

             # Automatically kill old snapshots...

-            snaps = self.fssnap.old_snapshots()

+            cleanup_fail = False

+            try:

+                snaps = self.fssnap.old_snapshots()

+            except LibLVMError as e:

+                self.verbose_logger.debug(lvmerr2str(e))

+                cleanup_fail = True

+                snaps = []

             snaps = sorted(snaps, key=lambda x: (x['ctime'], x['origin_dev']),

                            reverse=True)

             last = '<n/a>'

@@ -1754,30 +1794,22 @@ much more problems).

                 if num > self.conf.fssnap_automatic_keep:

                     todel.append(snap['dev'])

             # Display something to the user?

-            snaps = self.fssnap.del_snapshots(devices=todel)

+            try:

+                snaps = self.fssnap.del_snapshots(devices=todel)

+            except LibLVMError as e:

+                self.verbose_logger.debug(lvmerr2str(e))

+                cleanup_fail = True

+                snaps = []

             if len(snaps):

                 self.verbose_logger.info(_("Deleted %u snapshots.") % len(snaps))

+            elif cleanup_fail:

+                self.verbose_logger.warning(_("Skipping the cleanup of old "

+                                              "snapshots due to errors"))

         if (self.fssnap.available and

             (not self.ts.isTsFlagSet(rpm.RPMTRANS_FLAG_TEST) and

             self.conf.fssnap_automatic_pre)):

-            if not self.fssnap.has_space(self.conf.fssnap_percentage):

-                msg = _("Not enough space on logical volumes to create pre. FS snapshot.")

-                if self.conf.fssnap_abort_on_errors in ('snapshot-failure', 'any'):

-                    raise Errors.YumRPMTransError(msg="Aborting transaction", errors=msg)

-                else:

-                    self.verbose_logger.critical(msg)

-            else:

-                tags = {'*': ['reason=automatic']} # FIXME: pre. tags

-                snaps = self.fssnap.snapshot(self.conf.fssnap_percentage, tags=tags)

-                if not snaps:

-                    msg = _("Failed to create snapshot")

-                    if self.conf.fssnap_abort_on_errors in ('snapshot-failure', 'any'):

-                        raise Errors.YumRPMTransError(msg="Aborting transaction", errors=msg)

-                    else:

-                        self.verbose_logger.critical(msg)

-                for (odev, ndev) in snaps:

-                    self.verbose_logger.info(_("Created snapshot from %s, results is: %s") % (odev, ndev))

+            create_snapshot()

         self.plugins.run('pretrans')

@@ -1912,16 +1944,7 @@ much more problems).

         if (self.fssnap.available and

             (not self.ts.isTsFlagSet(rpm.RPMTRANS_FLAG_TEST) and

             self.conf.fssnap_automatic_post)):

-            if not self.fssnap.has_space(self.conf.fssnap_percentage):

-                msg = _("Not enough space on logical volumes to create post trans FS snapshot.")

-                self.verbose_logger.critical(msg)

-            else:

-                tags = {'*': ['reason=automatic']} # FIXME: post tags

-                snaps = self.fssnap.snapshot(self.conf.fssnap_percentage, tags=tags)

-                if not snaps:

-                    self.verbose_logger.critical(_("Failed to create snapshot"))

-                for (odev, ndev) in snaps:

-                    self.verbose_logger.info(_("Created snapshot from %s, results is: %s") % (odev, ndev))

+            create_snapshot(post=True)

         return resultobject

     def verifyTransaction(self, resultobject=None, txmbr_cb=None):