Now that cgroups/security driver/locking driver support labelling of
individual images and tolerate network storage we don't have to refrain
from passing all image files to it. This allows removing the checking
code as we already make sure that the snapshot function won't be called
with unsupported options.
Now that security, cgroup and locking APIs support working on individual
images and we track the backing chain security info on a per-image basis
we can finally kill swapping the disk source in virDomainDiskDef and use
the virStorageSource directly.
Until now we were changing information about the disk source via
multiple steps of copying data. Now that we changed to a pointer to
store the disk source we might use it to change the approach to track
the data.
Additionally this will allow proper tracking of the backing chain.
When pivoting to a new disk source after a block commit (and possibly
after a soon-to-be-added active block commit) we changed just a few
fields to the new target. In case we'd copy a network disk to a local
file we'd not change the type properly.
To avoid such problems, switch to tracking of the source via changing of
the complete source struct to the one tracking the mirroring info.
Use the source struct and the corresponding function so that we can
avoid using the path separately. Now that
qemuDomainPrepareDiskChainElementPath isn't use anywhere, we can safely
remove it.
Additionally, the removal fixes a misaligned comment as the removed
function was added under a comment for a different function.
Add security driver functions to label separate storage images using the
virStorageSource definition. This will help to avoid the need to do ugly
changes to the disk struct and use the source directly.
Add functions that will allow to set all the required cgroup stuff on
individual images taking a virStorageSourcePtr. Also convert functions
designed to setup whole backing chain to take advantage of the change.
When dispatching events from the event loop, the array of registered
handles is searched to see what handles happened an event on. However,
the array is searched in weird way: the check for the array boundaries
is at the end, so we may touch the elements after the end of the
array:
==10434== Invalid read of size 4
==10434== at 0x52D06B6: virEventPollDispatchHandles (vireventpoll.c:486)
==10434== by 0x52D10E4: virEventPollRunOnce (vireventpoll.c:660)
==10434== by 0x52CF207: virEventRunDefaultImpl (virevent.c:308)
==10434== by 0x1639D1: virNetServerRun (virnetserver.c:1139)
==10434== by 0x1220DC: main (libvirtd.c:1507)
==10434== Address 0xc11ff04 is 4 bytes after a block of size 960 alloc'd
==10434== at 0x4C2CA5E: realloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==10434== by 0x52AD378: virReallocN (viralloc.c:245)
==10434== by 0x52AD46E: virExpandN (viralloc.c:294)
==10434== by 0x52AD5B1: virResizeN (viralloc.c:352)
==10434== by 0x52CF2EC: virEventPollAddHandle (vireventpoll.c:116)
==10434== by 0x52CEF5B: virEventAddHandle (virevent.c:78)
==10434== by 0x11F69A90: nodeStateInitialize (node_device_udev.c:1797)
==10434== by 0x53C3C89: virStateInitialize (libvirt.c:743)
==10434== by 0x120563: daemonRunStateInit (libvirtd.c:919)
==10434== by 0x5317719: virThreadHelper (virthread.c:197)
==10434== by 0x8376F39: start_thread (in /lib64/libpthread-2.17.so)
==10434== by 0x8A7F9FC: clone (in /lib64/libc-2.17.so)
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Commit a48f445100 introduced a helper
function to convert cgroup device mode to string. The function was only
conditionally compiled on platforms that support cgroup. This broke the
build when attempting to export the symbol:
CCLD libvirt.la
Cannot export virCgroupGetDevicePermsString: symbol not defined
Move the function out of the ifdef, as it doesn't really depend on the
cgroup code being present.
In libxlDomainMigrationConfirm(), a transient domain is removed
from the domain list after successful migration. Later in cleanup,
the domain object is unlocked, resulting in a crash
Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x7fb4208ed700 (LWP 12044)]
0x00007fb4267251e6 in virClassIsDerivedFrom (klass=0xdeadbeef,
parent=0x7fb42830d0c0) at util/virobject.c:169
169 if (klass->magic == parent->magic)
(gdb) bt
0 0x00007fb4267251e6 in virClassIsDerivedFrom (klass=0xdeadbeef,
parent=0x7fb42830d0c0) at util/virobject.c:169
1 0x00007fb42672591b in virObjectIsClass (anyobj=0x7fb4100082b0,
klass=0x7fb42830d0c0) at util/virobject.c:365
2 0x00007fb42672583c in virObjectUnlock (anyobj=0x7fb4100082b0)
at util/virobject.c:338
3 0x00007fb41a8c7d7a in libxlDomainMigrationConfirm (driver=0x7fb4100404c0,
vm=0x7fb4100082b0, flags=1, cancelled=0) at libxl/libxl_migration.c:583
Fix by setting the virDomainObjPtr to NULL after removing it from
the domain list.
During migration, the libxl driver starts a modify job in the
begin phase, ending the job in the confirm phase. This is
essentially VIR_MIGRATE_CHANGE_PROTECTION semantics, but the
driver does not support that flag. Without CHANGE_PROTECTION
support, the job would never be terminated in error conditions
where migrate confirm phase is not executed. Further attempts
to modify the domain would result in failure to acquire a job
after LIBXL_JOB_WAIT_TIME.
Similar to the qemu driver, end the job in the begin phase.
Protecting the domain object across all phases of migration can
be done in a future patch adding CHANGE_PROTECTION support.
In libxlDomainMigrationPrepare(), a new virDomainObj is created
from the incoming domain def and added to the driver's domain
list, but never removed if there are subsequent failures during
the prepare phase.
targethost# virsh list --all
sourcehost# virsh migrate --live dom xen+ssh://targethost/system
error: operation failed: Fail to create socket for incoming migration.
targethost# virsh list --all
error: Failed to list domains
error: name in virGetDomain must not be NULL
After adding code to remove the domain on prepare failure, noticed
that libvirtd crashed due to double free of the virDomainDef. Similar
to the qemu driver, pass a pointer to virDomainDefPtr so it can be set
to NULL once a virDomainObj is created from it.
Qemu will fallback to aio=threads when the cache mode doesn't use
O_DIRECT, even if aio=native was explictly set.
Closes: https://bugzilla.redhat.com/show_bug.cgi?id=1086704
Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>
When run under an environment that inherits an ignored SIGPIPE
(hello, annoying buildbots), a syntax-check was producing quite
a bit of noise, such as:
> prohibit_argmatch_without_use
> grep: write error
> grep: write error
> /bin/sed: couldn't write 25 items to stdout: Broken pipe
> sed: couldn't write 1 item to stdout: Broken pipe
> 0.46 prohibit_argmatch_without_use
This has been fixed upstream in gnulib. There are several other
portability improvements in our regular submodule update.
* .gnulib: Update to latest, in part for quieter syntax-check.
Signed-off-by: Eric Blake <eblake@redhat.com>
Cgroups code uses VIR_CGROUP_DEVICE_* flags to specify the mode but in
the end it needs to be converted to a string. Add a helper to do it and
use it in the cgroup code before introducing it into the rest of the
code.
When discovering a disk backing chain the parent disk's metadata need to
be populated into the guest images so that each piece of the backing
chain contains a copy of those. This will allow us to refactor the
security driver so that it will not need to carry around the original
disk definition.
We are going to modify storage source chains in place. Add a helper that
will copy relevant information such as security labels to the new
element if that doesn't contain it.
In the future we might need to track state of individual images. Move
the readonly and shared flags to the virStorageSource struct so that we
can keep them in a per-image basis.
Some of the further changes will propagate seclabels from a disk source
element into the backing store elements. This would change the XML
output of the backing store as the seclabels would be formatted for each
backing store element. Skip the seclabels formatting until we decide
that it's necessary.
Now that we are able to select images from the backing chain via indexed
access we should also convert possible network sources to
qemu-compatible strings before passing them to qemu.
Now that we are able to select images from the backing chain via indexed
access we should also convert possible network sources to
qemu-compatible strings before passing them to qemu.
Introduce flag for the block rebase API to allow the rebase operation to
leave the chain relatively addressed. Also adds a virsh switch to enable
this behavior.
Introduce flag for the block commit API to allow the commit operation to
leave the chain relatively addressed. Also adds a virsh switch to enable
this behavior.
The qemu block info function relied on working with local storage. Break
this assumption by adding support for remote volumes. Unfortunately we
still need to take a hybrid approach as some of the operations require a
filedescriptor.
Previously you'd get:
$ virsh domblkinfo gl vda
error: cannot stat file '/img10': Bad file descriptor
Now you get some stats:
$ virsh domblkinfo gl vda
Capacity: 10485760
Allocation: 197120
Physical: 197120
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1110198
To allow reusing this function in the qemu driver we need to allow
specifying the storage format. Also separate return of the backing store
path now isn't necessary.
