POSIX does not guarantee whether uid_t and gid_t are signed or
unsigned, nor does it guarantee whether they are smaller, same
size, or larger than int (or even the same size as one another).
Therefore, it is possible to have platforms where '(uid_t)-1==-1'
is false or where 'uid = gid = -1' sets uid to the wrong value,
thanks to integer promotion rules. The only portable way to use
the placeholder value of these two types is to always use a cast.
Thankfully, the issue is mostly theoretical - sanlock only
compiles on Linux for now, and on Linux, these types do not
suffer from strange promotion problems.
* src/locking/lock_driver_sanlock.c
(virLockManagerSanlockSetupLockspace, virLockManagerSanlockInit)
(virLockManagerSanlockCreateLease): Cast -1 to proper type before
comparing with uid_t or gid_t.
Since sanlock doesn't run under root:root, we have chown()'ed the
__LIBVIRT__DISKS__ lease file to the user:group defined in the
sanlock config. However, when writing the patch I've forgot about
lease files for each disk (this is the
/var/lib/libvirt/sanlock/<md5>) file.
Currently, if sanlock is already registering a lockspace other
libvirtd instances (from other hosts) obtain -EINPROGRESS. On
sufficiently new sanlock, sanlock_inq_lockspace() is called,
which suspend execution until lockspace state is changed. With
current libvirt implementation, we fail to retry adding the
lockspace again but continue in error path. Therefore we produce
meaningless error message:
virLockManagerSanlockSetupLockspace:363 : Unable to add lockspace
/var/lib/libvirt/sanlock/__LIBVIRT__DISKS__: Success
qemudLoadDriverConfig:558 : Failed to load lock manager sanlock
We should try to re-add the lockspace after its state change to
be sure it was added successfully. In fact, with sufficiently new
sanlock we can just avoid dummy usleep() which is used if there's
no inquire API.
It may take some time for sanlock to add a lockspace. And if user
restart libvirtd service meanwhile, the fresh daemon can fail adding
the same lockspace with EINPROGRESS. Recent sanlock has
sanlock_inq_lockspace() function which should block until lockspace
changes state. If we are building against older sanlock we should
retry a few times before claiming an error. This issue can be easily
reproduced:
for i in {1..1000} ; do echo $i; service libvirtd restart; sleep 2; done
20
Stopping libvirtd daemon: [FAILED]
Starting libvirtd daemon: [ OK ]
21
Stopping libvirtd daemon: [ OK ]
Starting libvirtd daemon: [ OK ]
22
Stopping libvirtd daemon: [ OK ]
Starting libvirtd daemon: [ OK ]
error : virLockManagerSanlockSetupLockspace:334 : Unable to add
lockspace /var/lib/libvirt/sanlock/__LIBVIRT__DISKS__: Operation now in
progress
The libvirt coding standard is to use 'function(...args...)'
instead of 'function (...args...)'. A non-trivial number of
places did not follow this rule and are fixed in this patch.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
libvirt started using sanlock_killpath to implement on_lockfailure
action. Since sanlock_killpath was introduced in sanlock 2.4, libvirt
fails to build with older sanlock.
While the changes to sanlock driver should be stable, the actual
implementation of sanlock_helper is supposed to be replaced in the
future. However, before we can implement a better sanlock_helper, we
need an administrative interface to libvirtd so that the helper can just
pass a "leases lost" event to the particular libvirt driver and
everything else will be taken care of internally. This approach will
also allow libvirt to pass such event to applications and use
appropriate reasons when changing domain states.
The temporary implementation handles all actions directly by calling
appropriate libvirt APIs (which among other things means that it needs
to know the credentials required to connect to libvirtd).
https://www.gnu.org/licenses/gpl-howto.html recommends that
the 'If not, see <url>.' phrase be a separate sentence.
* tests/securityselinuxhelper.c: Remove doubled line.
* tests/securityselinuxtest.c: Likewise.
* globally: s/; If/. If/
Generating "Unable to add lockspace /lock/space/dir/__LIBVIRT__DISKS__:
No such file or directory" is correct but not exactly clear. This patch
changes the error message to "Unable to create lockspace
/lock/space/dir/__LIBVIRT__DISKS__: parent directory does not exist or
is not a directory".
This is a patch for bug 847848
If registering an existing lockspace with the sanlock daemon
returns an error, libvirt should not proceed to unlink the lockspace.
Signed-off-by: Asad Saeed <asad.saeed@acidseed.com>
This is a patch for bug 826704
All sanlock resources get released when hot-dettaching a disk from the domain
because virLockManagerSanlockRelease uses the wrong function parameters/flags.
With the patch only the resources that should be released are cleaned up.
Signed-off-by: Frido Roose <frido.roose@gmail.com>
Per the FSF address could be changed from time to time, and GNU
recommends the following now: (http://www.gnu.org/licenses/gpl-howto.html)
You should have received a copy of the GNU General Public License
along with Foobar. If not, see <http://www.gnu.org/licenses/>.
This patch removes the explicit FSF address, and uses above instead
(of course, with inserting 'Lesser' before 'General').
Except a bunch of files for security driver, all others are changed
automatically, the copyright for securify files are not complete,
that's why to do it manually:
src/security/security_selinux.h
src/security/security_driver.h
src/security/security_selinux.c
src/security/security_apparmor.h
src/security/security_apparmor.c
src/security/security_driver.c
A sanlock lease can be marked as shared (rather
than exclusive) using SANLK_RES_SHARED flag. This
adds support for that flag and ensures that in auto
disk mode, any shared disks use shared leases. This
also makes any read-only disks be completely
ignored.
These changes remove the need for the option
ignore_readonly_and_shared_disks
so that is removed
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The function sanlock_inquire can return NULL in the state string if the
message consists only of a header. The return value is arbitrary and
sent by the server. We should proceed carefully while touching such
pointers.
Detected by Coverity. The only way to get to error_unlink is if
path was successfully assigned, so the if was useless. Meanwhile,
there was a return statement that did not free path.
* src/locking/lock_driver_sanlock.c
(virLockManagerSanlockSetupLockspace): Fix mem-leak, and drop
useless if.
Inexplicably the sanlock code all got placed under the GPLv2-only,
so libvirt's use of sanlock introduces a license incompatibility.
The sanlock developers have now rearranged the code such that there
is a 'sanlock_client.so' which is LGPLv2+ while their daemon remains
GPLv2-only. To use the new client library we need to call the new
sanlock_init and sanlock_align APIs instead of sanlock_direct_init
and sanlock_direct_align. These APIs calls are now routed via the
sanlock daemon, instead of doing direct I/O calls to disk.
For all this we require sanlock >= 1.8
* configure.ac: Check for sanlock_client.so instead of sanlock.so
and fix various comments
* libvirt.spec.in: Mandate sanlock >= 1.8
* src/Makefile.am: Link to -lsanlock_client
* src/locking/lock_driver_sanlock.c: Use sanlock_init and
sanlock_align
The code for creating a sanlock lockspace accidentally used
SANLK_NAME_LEN instead of SANLK_PATH_LEN for a size check.
This meant disk paths were limited to 48 bytes !
* src/locking/lock_driver_sanlock.c: Fix disk path length
check
Continuation of commit 313ac7fd, and enforce things with a syntax
check.
Technically, virNetServerClientCalculateHandleMode is not printing
a mode_t, but rather a collection of VIR_EVENT_HANDLE_* bits;
however, these bits are < 8, so there is no different in the
output, and that was the easiest way to silence the new syntax check.
* cfg.mk (sc_flags_debug): New syntax check.
(exclude_file_name_regexp--sc_flags_debug): Add exemptions.
* src/fdstream.c (virFDStreamOpenFileInternal): Print flags in
hex, mode_t in octal.
* src/libvirt-qemu.c (virDomainQemuMonitorCommand)
(virDomainQemuAttach): Likewise.
* src/locking/lock_driver_nop.c (virLockManagerNopInit): Likewise.
* src/locking/lock_driver_sanlock.c (virLockManagerSanlockInit):
Likewise.
* src/locking/lock_manager.c: Likewise.
* src/qemu/qemu_migration.c: Likewise.
* src/qemu/qemu_monitor.c: Likewise.
* src/rpc/virnetserverclient.c
(virNetServerClientCalculateHandleMode): Print mode with %o.
No caller was using the flags argument, and this function is internal
only, so we might as well skip it.
* src/util/util.h (safezero): Update signature.
* src/util/util.c (safezero): Update function.
* src/locking/lock_driver_sanlock.c
(virLockManagerSanlockSetupLockspace)
(virLockManagerSanlockCreateLease): Update all callers.
* src/storage/storage_backend.c (createRawFile): Likewise.
The current sanlock plugin requires a central management
application to manually add <lease> elements to each guest,
to protect resources that are assigned to it (eg writable
disks). This makes the sanlock plugin useless for usage
in more ad hoc deployment environments where there is no
central authority to associate disks with leases.
This patch adds a mode where the sanlock plugin will
automatically create leases for each assigned read-write
disk, using a md5 checksum of the fully qualified disk
path. This can work pretty well if guests are using
stable disk paths for block devices eg /dev/disk/by-path/XXXX
symlinks, or if all hosts have NFS volumes mounted in
a consistent pattern.
The plugin will create one lockspace for managing disks
with filename /var/lib/libvirt/sanlock/__LIBVIRT__DISKS__.
For each VM disks, there will be another file to hold
a lease /var/lib/libvirt/sanlock/5903e5d25e087e60a20fe4566fab41fd
Each VM disk lease is usually 1 MB in size. The script
virt-sanlock-cleanup should be run periodically to remove
unused lease files from the lockspace directory.
To make use of this capability the admin will need to do
several tasks:
- Mount an NFS volume (or other shared filesystem)
on /var/lib/libvirt/sanlock
- Configure 'host_id' in /etc/libvirt/qemu-sanlock.conf
with a unique value for each host with the same NFS
mount
- Toggle the 'auto_disk_leases' parameter in qemu-sanlock.conf
Technically the first step can be skipped, in which case
sanlock will only protect against 2 vms on the same host
using the same disk (or the same VM being started twice
due to error by libvirt).
* src/locking/libvirt_sanlock.aug,
src/locking/sanlock.conf,
src/locking/test_libvirt_sanlock.aug: Add config params
for configuring auto lease setup
* libvirt.spec.in: Add virt-sanlock-cleanup program, man
page
* tools/virt-sanlock-cleanup.in: Script to purge unused
disk resource lease files
Introduce a configuration file with a single parameter
'require_lease_for_disks', which is used to decide whether
it is allowed to start a guest which has read/write disks,
but without any leases.
* libvirt.spec.in: Add sanlock config file and augeas
lens
* src/Makefile.am: Install sanlock config file and
augeas lens
* src/locking/libvirt_sanlock.aug: Augeas master lens
* src/locking/test_libvirt_sanlock.aug: Augeas test file
* src/locking/sanlock.conf: Example sanlock config
* src/locking/lock_driver_sanlock.c: Wire up loading
of configuration file
Allow a 'configFile' parameter to be passed into the lock
drivers to provide configuration. Wire up the QEMU driver
to pass in file names '/etc/libvirt/qemu-$NAME.conf
eg qemu-sanlock.conf
* src/locking/lock_driver.h, src/locking/lock_driver_nop.c,
src/locking/lock_driver_sanlock.c, src/locking/lock_manager.c,
src/locking/lock_manager.h: Add configFile parameter
* src/qemu/qemu_conf.c: Pass in configuration file path to
lock driver plugins
The libvirt sanlock plugin is intentionally leaking a file
descriptor to QEMU. To enable QEMU to use this FD under
SELinux, it must be labelled correctly. We dont want to use
the svirt_image_t for this, since QEMU must not be allowed
to actually use the FD. So instead we label it with svirt_t
using virSecurityManagerSetProcessFDLabel
* src/locking/domain_lock.c, src/locking/domain_lock.h,
src/locking/lock_driver.h, src/locking/lock_driver_nop.c,
src/locking/lock_driver_sanlock.c, src/locking/lock_manager.c,
src/locking/lock_manager.h: Optionally pass an FD back to
the hypervisor for security driver labelling
* src/qemu/qemu_process.c: label the lock manager plugin
FD with the process label
When virLockDriverAcquire is invoked during hotplug the state
parameter will be left as NULL.
* src/locking/lock_driver_nop.c,
src/locking/lock_driver_sanlock.c: Don't reference NULL state
parameter
In between fork and exec, a connection to sanlock is acquired
and the socket file descriptor is intionally leaked to the
child process. sanlock watches this FD for POLL_HANGUP to
detect when QEMU has exited. We don't want a rogus/compromised
QEMU from issuing sanlock RPC calls on the leaked FD though,
since that could be used to DOS other guests. By calling
sanlock_restrict() on the socket before exec() we can lock
it down.
* configure.ac: Check for sanlock_restrict API
* src/locking/domain_lock.c: Restrict lock acquired in
process startup phase
* src/locking/lock_driver.h: Add VIR_LOCK_MANAGER_ACQUIRE_RESTRICT
* src/locking/lock_driver_sanlock.c: Add call to sanlock_restrict
when requested by VIR_LOCK_MANAGER_ACQUIRE_RESTRICT flag
Sanlock is a project that implements a disk-paxos locking
algorithm. This is suitable for cluster deployments with
shared storage.
* src/Makefile.am: Add dlopen plugin for sanlock
* src/locking/lock_driver_sanlock.c: Sanlock driver
* configure.ac: Check for sanlock
* libvirt.spec.in: Add a libvirt-lock-sanlock RPM
