Commit Graph

116 Commits

Author SHA1 Message Date
Peter Krempa
3bf5f0427a sanlock: Fix condition left crippled while debugging 2012-03-08 11:49:32 +01:00
Eric Blake
a55f18929b sanlock: fix memory leak
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.
2011-09-22 13:32:20 +08:00
Daniel P. Berrange
19ff0ddfbb Update to require sanlock 1.8 for license compliance
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
2011-09-20 11:18:54 +08:00
Daniel P. Berrange
2223b1f71f Fix incorrect path length check in sanlock lockspace setup
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
2011-08-31 11:07:31 +01:00
Eric Blake
8e22e08935 build: rename files.h to virfile.h
In preparation for a future patch adding new virFile APIs.

* src/util/files.h, src/util/files.c: Move...
* src/util/virfile.h, src/util/virfile.c: ...here, and rename
functions to virFile prefix.  Macro names are intentionally
left alone.
* *.c: All '#include "files.h"' uses changed.
* src/Makefile.am (UTIL_SOURCES): Reflect rename.
* cfg.mk (exclude_file_name_regexp--sc_prohibit_close): Likewise.
* src/libvirt_private.syms: Likewise.
* docs/hacking.html.in: Likewise.
* HACKING: Regenerate.
2011-07-21 10:34:51 -06:00
Eric Blake
37754a74bb maint: fix typos
Our XML prefers "shareable" over "sharable".

* docs/internals/locking.html.in: s/sharable/shareable/
* src/locking/lock_driver_sanlock.c
(virLockManagerSanlockAddResource): Likewise.
2011-07-15 12:15:04 -06:00
Eric Blake
06dbfa6d21 maint: print flags in hex during debug
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.
2011-07-13 07:47:45 -06:00
Federico Simoncelli
de2aa6cfc7 sanlock: avoid lockspace setup when auto_disk_lease is off
When auto_disk_lease is off we should avoid the automatic lockspace
creation.

Signed-off-by: Federico Simoncelli <fsimonce@redhat.com>
2011-07-08 14:49:10 -06:00
Eric Blake
17da0669e0 util: drop unused safezero argument
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.
2011-07-07 14:15:38 -06:00
Daniel P. Berrange
97e4f21782 Support automatic creation of leases for disks in sanlock
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
2011-06-28 18:18:06 +01:00
Daniel P. Berrange
58eb4f2cbb Support loading a configuration file for sanlock plugin
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
2011-06-28 18:07:06 +01:00
Daniel P. Berrange
5df29ebc25 Allow per-driver config file for lock manager plugins
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
2011-06-28 18:07:06 +01:00
Daniel P. Berrange
5247b0695a Ensure sanlock socket is labelled with the VM process label
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
2011-06-28 16:41:46 +01:00
Daniel P. Berrange
eb661ce3ee Avoid crash on NULL pointer in lock driver impls during hotplug
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
2011-06-02 17:23:45 +01:00
Daniel P. Berrange
ebfb8c4243 Add call to sanlock_restrict() in QEMU lock driver
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
2011-06-02 17:23:44 +01:00
Daniel P. Berrange
9f135031ff Add a plugin for the 'sanlock' project
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
2011-06-02 10:54:01 +01:00