https://bugzilla.redhat.com/show_bug.cgi?id=965169 documents a
problem starting domains when cgroups are enabled; I was able
to reliably reproduce the race about 5% of the time when I added
hooks to domain startup by 3 seconds (as that seemed to be about
the length of time that qemu created and then closed a temporary
thread, probably related to aio handling of initially opening
a disk image). The problem has existed since we introduced
virCgroupMoveTask in commit 9102829 (v0.10.0).
There are some inherent TOCTTOU races when moving tasks between
kernel cgroups, precisely because threads can be created or
completed in the window between when we read a thread id from the
source and when we write to the destination. As the goal of
virCgroupMoveTask is merely to move ALL tasks into the new
cgroup, it is sufficient to iterate until no more threads are
being created in the old group, and ignoring any threads that
die before we can move them.
It would be nicer to start the threads in the right cgroup to
begin with, but by default, all child threads are created in
the same cgroup as their parent, and we don't want vcpu child
threads in the emulator cgroup, so I don't see any good way
of avoiding the move. It would also be nice if the kernel were
to implement something like rename() as a way to atomically move
a group of threads from one cgroup to another, instead of forcing
a window where we have to read and parse the source, then format
and write back into the destination.
* src/util/vircgroup.c (virCgroupAddTaskStrController): Ignore
ESRCH, because a thread ended between read and write attempts.
(virCgroupMoveTask): Loop until all threads have moved.
Signed-off-by: Eric Blake <eblake@redhat.com>
(cherry picked from commit 83e4c77547)
This resolves:
https://bugzilla.redhat.com/show_bug.cgi?id=851411https://bugzilla.redhat.com/show_bug.cgi?id=955500
The first problem was that virFileOpenAs was returning fd (-1) in one
of the error cases rather than ret (-errno), so the caller thought
that the error was EPERM rather than ENOENT.
The second problem was that some log messages in the general purpose
qemuOpenFile() function would always say "Failed to create" even if
the caller hadn't included O_CREAT (i.e. they were trying to open an
existing file).
This fixes virFileOpenAs to jump down to the error return (which
returns ret instead of fd) in the previously mentioned incorrect
failure case of virFileOpenAs(), removes all error logging from
virFileOpenAs() (since the callers report it), and modifies
qemuOpenFile to appropriately use "open" or "create" in its log
messages.
NB: I seriously considered removing logging from all callers of
virFileOpenAs(), but there is at least one case where the caller
doesn't want virFileOpenAs() to log any errors, because it's just
going to try again (qemuOpenFile()). We can't simply make a silent
variation of virFileOpenAs() though, because qemuOpenFile() can't make
the decision about whether or not it wants to retry until after
virFileOpenAs() has already returned an error code.
Likewise, I also considered changing virFileOpenAs() to return -1 with
errno set on return, and may still do that, but only as a separate
patch, as it obscures the intent of this patch too much.
(cherry picked from commit a2c1bedbd8)
POSIX says pthread_t is opaque. We can't guarantee if it is scaler
or a pointer, nor what size it is; and BSD differs from Linux.
We've also had reports of gcc complaining on attempts to cast it,
if we use a cast to the wrong type (for example, pointers have to be
cast to void* or intptr_t before being narrowed; while casting a
function return of scalar pthread_t to void* triggers a different
warning).
Give up on casts, and use unions to get at decent bits instead. And
rather than futz around with figuring which 32 bits of a potentially
64-bit pointer are most likely to be unique, convert the rest of
the code base to use 64-bit values when using a debug id.
Based on a report by Guido Günther against kFreeBSD, but with a
fix that doesn't regress commit 4d970fd29 for FreeBSD.
* src/util/virthreadpthread.c (virThreadSelfID, virThreadID): Use
union to get at a decent bit representation of thread_t bits.
* src/util/virthread.h (virThreadSelfID, virThreadID): Alter
signature.
* src/util/virthreadwin32.c (virThreadSelfID, virThreadID):
Likewise.
* src/qemu/qemu_domain.h (qemuDomainJobObj): Alter type of owner.
* src/qemu/qemu_domain.c (qemuDomainObjTransferJob)
(qemuDomainObjSetJobPhase, qemuDomainObjReleaseAsyncJob)
(qemuDomainObjBeginNestedJob, qemuDomainObjBeginJobInternal): Fix
clients.
* src/util/virlog.c (virLogFormatString): Likewise.
* src/util/vireventpoll.c (virEventPollInterruptLocked):
Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
(cherry picked from commit 22d12905e6)
Commit 776d49f4 added a static function that is only called
conditionally; leading to this compile error on mingw:
CC libvirt_util_la-virprocess.lo
../../src/util/virprocess.c:624:26: error: 'struct rlimit' declared inside parameter list [-Werror]
../../src/util/virprocess.c:624:26: error: its scope is only this definition or declaration, which is probably not what you want [-Werror]
../../src/util/virprocess.c:622:1: error: 'virProcessPrLimit' defined but not used [-Werror=unused-function]
* src/util/virprocess.c (virProcessPrLimit): Only declare
virProcessPrLimit when used.
Signed-off-by: Eric Blake <eblake@redhat.com>
(cherry picked from commit 05f79a3894)
virPCIDeviceReattach and virPCIDeviceUnbindFromStub (called by
virPCIDeviceReattach) had previously required the name of the stub
driver as input. This is unnecessary, because the name of the driver
the device is currently bound to can be found by looking at the link:
/sys/bus/pci/dddd:bb:ss.ff/driver
Instead of requiring that the name of the expected stub driver name
and only unbinding if that one name is matched, we no longer take a
driver name in the arglist for either of these
functions. virPCIDeviceUnbindFromStub just compares the name of the
currently bound driver to a list of "well known" stubs (right now
contains "pci-stub" and "vfio-pci" for qemu, and "pciback" for xen),
and only performs the unbind if it's one of those devices.
This allows virsh nodedevice-reattach to work properly across a
libvirtd restart, and fixes a couple of cases where we were
erroneously still hard-coding "pci-stub" as the drive name.
For some unknown reason, virPCIDeviceReattach had been calling
modprobe on the stub driver prior to unbinding the device. This was
problematic because we no longer know the name of the stub driver in
that function. However, it is pointless to probe for the stub driver
at that time anyway - because the device is bound to the stub driver,
we are guaranteed that it is already loaded, and so that call to
modprobe has been removed.
On cygwin, compilation failed because SIOCSIFHWADDR is undefined.
* src/util/virnetdev.c (virNetDevSetMAC): Cygwin can query but not
set mac address.
Signed-off-by: Eric Blake <eblake@redhat.com>
FreeBSD (and maybe other BSDs) have different member
names in struct ifreq when compared to Linux, such as:
- uses ifr_data instead of ifr_newname for setting
interface names
- uses ifr_index instead of ifr_ifindex for interface
index
Also, add a check for SIOCGIFHWADDR for virNetDevValidateConfig().
Use AF_LOCAL if AF_PACKET is not available.
Signed-off-by: Eric Blake <eblake@redhat.com>
These fixes solve a compilation failure on FreeBSD:
util/virnetdevtap.c: In function 'virNetDevTapGetName':
util/virnetdevtap.c:56: warning: unused parameter 'tapfd' [-Wunused-parameter]
util/virnetdevtap.c:56: warning: unused parameter 'ifname' [-Wunused-parameter]
* src/util/virnetdevtap.c (virNetDevTapGetName): Add attributes
when TUNGETIFF is not present.
Signed-off-by: Eric Blake <eblake@redhat.com>
This will be used on a tap file descriptor returned by the bridge helper
to populate the <target> element, because the helper does not provide
the interface name.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This patch adds two sets of functions:
1) lower level virProcessSet*() functions that will immediately set
the RLIMIT_MEMLOCK. RLIMIT_NPROC, or RLIMIT_NOFILE of either the
current process (using setrlimit()) or any other process (using
prlimit()). "current process" is indicated by passing a 0 for pid.
2) functions for virCommand* that will setup a virCommand object to
set those limits at a later time just after it has forked a new
process, but before it execs the new program.
configure.ac has prlimit and setrlimit added to the list of functions
to check for, and the low level functions log an "unsupported" error)
on platforms that don't support those functions.
If a user cgroup name begins with "cgroup.", "_" or with any of
the controllers from /proc/cgroups followed by a dot, then they
need to be prefixed with a single underscore. eg if there is
an object "cpu.service", then this would end up as "_cpu.service"
in the cgroup filesystem tree, however, "waldo.service" would
stay "waldo.service", at least as long as nobody comes up with
a cgroup controller called "waldo".
Since we require a '.XXXX' suffix on all partitions, there is
no scope for clashing with the kernel 'tasks' and 'release_agent'
files.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
If the partition named passed in the XML does not already have
a suffix, ensure it gets a '.partition' added to each component.
The exceptions are /machine, /user and /system which do not need
to have a suffix, since they are fixed partitions at the top
level.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Recently we changed to create VM cgroups with the naming pattern
$VMNAME.$DRIVER.libvirt. Following discussions with the systemd
community it was decided that only having a single '.' in the
names is preferrable. So this changes the naming scheme to be
$VMNAME.libvirt-$DRIVER. eg for LXC 'mycontainer.libvirt-lxc' or
for KVM 'myvm.libvirt-qemu'.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
This can be set when the virPCIDevice is created and placed on a list,
then used later when traversing the list to determine which stub
driver to bind/unbind for managed devices.
The existing Detach and Attach functions' signatures haven't been
changed (they still accept a stub driver name in the arg list), but if
the arg list has NULL for stub driver and one is available in the
device's object, that will be used. (we may later deprecate and remove
the arg from those functions).
POSIX says that both basename() and dirname() may return static
storage (aka they need not be thread-safe); and that they may but
not must modify their input argument. Furthermore, <libgen.h>
is not available on all platforms. For these reasons, you should
never use these functions in a multi-threaded library.
Gnulib instead recommends a way to avoid the portability nightmare:
gnulib's "dirname.h" provides useful thread-safe counterparts. The
obvious dir_name() and base_name() are GPL (because they malloc(),
but call exit() on failure) so we can't use them; but the LGPL
variants mdir_name() (malloc's or returns NULL) and last_component
(always points into the incoming string without modifying it,
differing from basename semantics only on corner cases like the
empty string that we shouldn't be hitting in the first place) are
already in use in libvirt. This finishes the swap over to the safe
functions.
* cfg.mk (sc_prohibit_libgen): New rule.
* src/util/vircgroup.c: Fix offenders.
* src/parallels/parallels_storage.c (parallelsPoolAddByDomain):
Likewise.
* src/parallels/parallels_network.c (parallelsGetBridgedNetInfo):
Likewise.
* src/node_device/node_device_udev.c (udevProcessSCSIHost)
(udevProcessSCSIDevice): Likewise.
* src/storage/storage_backend_disk.c
(virStorageBackendDiskDeleteVol): Likewise.
* src/util/virpci.c (virPCIGetDeviceAddressFromSysfsLink):
Likewise.
* src/util/virstoragefile.h (_virStorageFileMetadata): Avoid false
positive.
Signed-off-by: Eric Blake <eblake@redhat.com>
Refactoring done in 19c6ad9ac7 didn't
correctly take into account the order cgroup limit modification needs to
be done in. This resulted into errors when decreasing the limits.
The operations need to take place in this order:
decrease hard limit
change swap hard limit
or
change swap hard limit
increase hard limit
This patch also fixes the check if the hard_limit is less than
swap_hard_limit to print better error messages. For this purpose I
introduced a helper function virCompareLimitUlong to compare limit
values where value of 0 is equal to unlimited. Additionally the check is
now applied also when the user does not provide all of the tunables
through the API and in that case the currently set values are used.
This patch resolves:
https://bugzilla.redhat.com/show_bug.cgi?id=950478
Create the utility function virSocketAddrGetIpPrefix() to
determine the prefix for this network. The code in this
function was adapted from virNetworkIpDefPrefix().
Update virNetworkIpDefPrefix() in src/conf/network_conf.c
to use the new utility function.
Signed-off-by: Gene Czarcinski <gene@czarc.net>
http://www.uhv.edu/ac/newsletters/writing/grammartip2009.07.01.htm
(and several other sites) give hints that 'onto' is best used if
you can also add 'up' just before it and still make sense. In many
cases in the code base, we really want the two-word form, or even
a simplification to just 'on' or 'to'.
* docs/hacking.html.in: Use correct 'on to'.
* python/libvirt-override.c: Likewise.
* src/lxc/lxc_controller.c: Likewise.
* src/util/virpci.c: Likewise.
* daemon/THREADS.txt: Use simpler 'on'.
* docs/formatdomain.html.in: Better usage.
* docs/internals/rpc.html.in: Likewise.
* src/conf/domain_event.c: Likewise.
* src/rpc/virnetclient.c: Likewise.
* tests/qemumonitortestutils.c: Likewise.
* HACKING: Regenerate.
Signed-off-by: Eric Blake <eblake@redhat.com>
When running unprivileged, virSetUIDGIDWithCaps will fail because it
tries to add the requested capabilities to the permitted and effective
sets.
Detect this case, and invoke the child with cleared permitted and
effective sets. If it is a setuid program, it will get them.
Some care is needed also because you cannot drop capabilities from the
bounding set without CAP_SETPCAP. Because of that, ignore errors from
setting the bounding set.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The need_prctl variable is not really needed. If it is false,
capng_apply will be called twice with the same set, causing
a little extra work but no problem. This keeps the code a bit
simpler.
It is also clearer to invoke capng_apply(CAPNG_SELECT_BOUNDS)
separately, to make sure it is done while we have CAP_SETPCAP.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The recent qemu requires "0x" prefix for the disk wwn, this patch
changes virValidateWWN to allow the prefix, and prepend "0x" if
it's not specified. E.g.
qemu-kvm: -device scsi-hd,bus=scsi0.0,channel=0,scsi-id=0,lun=0,\
drive=drive-scsi0-0-0-0,id=scsi0-0-0-0,wwn=6000c60016ea71ad:
Property 'scsi-hd.wwn' doesn't take value '6000c60016ea71ad'
Though it's a qemu regression, but it's nice to allow the prefix,
and doesn't hurt for us to always output "0x".
Detected by a simple Shell script:
for i in $(git ls-files -- '*.[ch]'); do
awk 'BEGIN {
fail=0
}
/# *include.*\.h/{
match($0, /["<][^">]*[">]/)
arr[substr($0, RSTART+1, RLENGTH-2)]++
}
END {
for (key in arr) {
if (arr[key] > 1) {
fail=1
printf("%d %s\n", arr[key], key)
}
}
if (fail == 1)
exit 1
}' $i
if test $? != 0; then
echo "Duplicate header(s) in $i"
fi
done;
A later patch will add the syntax-check to avoid duplicate
headers.
Fix the error
util/vircgroup.c: In function 'virCgroupNewDomainPartition':
util/vircgroup.c:1299:11: error: declaration of 'dirname' shadows a global declaration [-Werror=shadow]
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Add a virCgroupIsolateMount method which looks at where the
current process is place in the cgroups (eg /system/demo.lxc.libvirt)
and then remounts the cgroups such that this sub-directory
becomes the root directory from the current process' POV.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
If a cgroup controller is co-mounted with another, eg
/sys/fs/cgroup/cpu,cpuacct
Then it is a requirement that there exist symlinks at
/sys/fs/cgroup/cpu
/sys/fs/cgroup/cpuacct
pointing to the real mount point. Add support to virCgroupPtr
to detect and track these symlinks
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The virCgroupNewDriver method had a 'bool privileged' param.
If a false value was ever passed in, it would simply not
work, since non-root users don't have any privileges to create
new cgroups. Just delete this broken code entirely and make
the QEMU driver skip cgroup setup in non-privileged mode
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
A resource partition is an absolute cgroup path, ignoring the
current process placement. Expose a virCgroupNewPartition API
for constructing such cgroups
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Currently if virCgroupMakeGroup fails, we can get in a situation
where some controllers have been setup, but others not. Ensure
we call virCgroupRemove to remove what we've done upon failure
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Currently the virCgroupPtr struct contains 3 pieces of
information
- path - path of the cgroup, relative to current process'
cgroup placement
- placement - current process' placement in each controller
- mounts - mount point of each controller
When reading/writing cgroup settings, the path & placement
strings are combined to form the file path. This approach
only works if we assume all cgroups will be relative to
the current process' cgroup placement.
To allow support for managing cgroups at any place in the
heirarchy a change is needed. The 'placement' data should
reflect the absolute path to the cgroup, and the 'path'
value should no longer be used to form the paths to the
cgroup attribute files.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Rename all the virCgroupForXXX methods to use the form
virCgroupNewXXX since they are all constructors. Also
make sure the output parameter is the last one in the
list, and annotate all pointers as non-null. Fix up
all callers, and make sure they use true/false not 0/1
for the boolean parameters
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The definition of structs for cgroups are kept in vircgroup.c since
they are intended to be private from users of the API. To enable
effective testing, however, they need to be accessible. To address
the latter issue, without compronmising the former, this introduces
a new vircgrouppriv.h file to hold the struct definitions.
To prevent other files including this private header, it requires
that __VIR_CGROUP_ALLOW_INCLUDE_PRIV_H__ be defined before inclusion
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The virCgroupForDriver method recently gained an 'int controllers'
parameter, but the stub impl did not
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Though they are the same thing, mixed use of them is uncomfortable.
"unsigned" is used a lot in old codes, this just tries to change the
ones in utils.
