If the host side of an LXC container console disconnected
and the guest side continued to write data, until the PTY
buffer filled up, the LXC controller would busy wait. It
would repeatedly see POLLHUP from poll() and not disable
the watch.

This was due to some bogus logic detecting blocking
conditions. Upon seeing a POLLHUP we must disable all
reading & writing from the PTY, and setup the epoll to
wake us up again when the connection comes back.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Most of the usage of getuid()/getgid() is in cases where we are
considering what privileges we have. As such the code should be
using the effective IDs, not real IDs.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

A typo in the setup of NBD backed filesystems meant the
/dev/nbdN device would not be added to the cgroups device
ACL.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

In Fedora 20, libvirt_lxc crashes immediately at startup with a
trace

 #0  0x00007f0cddb653ec in free () from /lib64/libc.so.6
 #1  0x00007f0ce0e16f4a in virFree (ptrptr=ptrptr@entry=0x7f0ce1830058) at util/viralloc.c:580
 #2  0x00007f0ce0e2764b in virResetError (err=0x7f0ce1830030) at util/virerror.c:354
 #3  0x00007f0ce0e27a5a in virResetLastError () at util/virerror.c:387
 #4  0x00007f0ce0e28858 in virEventRegisterDefaultImpl () at util/virevent.c:233
 #5  0x00007f0ce0db47c6 in main (argc=11, argv=0x7fff4596c328) at lxc/lxc_controller.c:2352

Normally virInitialize calls virErrorInitialize and
virThreadInitialize, but we don't link to libvirt.so
in libvirt_lxc, and nor did we ever call the error
or thread initializers.

I have absolutely no idea how this has ever worked, let alone
what caused it to stop working in Fedora 20.

In addition not all code paths from virLogSetFromEnv will
ensure virLogInitialize is called correctly, which is another
possible crash scenario.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The LXC controller main() method initialized 'rc' to 1
rather than '-1'. In the cleanup path it will print any
error to stderr, if-and-only-if rc < 0. Hence the incorrect
initialization caused errors to be lost.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The LXC controller uses dbus to talk to systemd to create
cgroups. This means that each LXC controller instance has
a dbus connection. The DBus daemon is limited to 256
connections by default and we want to be able to run many
1000 of containers.

While the dbus limit could be raised in the config files,
it is simpler to make libvirt LXC controller close its
dbus connection once everything is configured.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

s/becuase/because/
Signed-off-by: NChen Hanxiao <chenhanxiao@cn.fujitsu.com>

* src/lxc/lxc_controller.c (virLXCControllerSetupDisk): Fix typo.
* src/lxc/lxc_driver.c (lxcDomainAttachDeviceDiskLive): Likewise.
Signed-off-by: NEric Blake <eblake@redhat.com>

This configuration knob lets user to set the length of queue of
connection requests waiting to be accept()-ed by the daemon. IOW, it
just controls the @backlog passed to listen:

  int listen(int sockfd, int backlog);

Convert the LXC driver code to use the new atomic API
for setup of cgroups
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Currently the LXC driver creates the VM's cgroup prior to
forking, and then libvirt_lxc moves the child process
into the cgroup. This won't work with systemd whose APIs
do the creation of cgroups + attachment of processes atomically.

Fortunately we simply move the entire cgroups setup into
the libvirt_lxc child process. We make it take place before
fork'ing into the background, so by the time virCommandRun
returns in the LXC driver, the cgroup is guaranteed to be
present.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

If no explicit driver is set for an image backed filesystem,
set it to use the loop driver (if raw) or nbd driver (if
non-raw)
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

A couple of places in LXC setup for filesystems did not do
a "goto cleanup" after reporting errors. While fixing this,
also add in many more debug statements to aid troubleshooting
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The 'driver->caps' pointer can be changed on the fly. Accessing
it currently requires the global driver lock. Isolate this
access in a single helper, so a future patch can relax the
locking constraints.

Wire up the new virDomainCreate{XML}WithFiles methods in the
LXC driver, so that FDs get passed down to the init process.

The lxc_container code needs to do a little dance in order
to renumber the file descriptors it receives into linear
order, starting from STDERR_FILENO + 1.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

These host devices are created for container,
the owner should be the root user of container.
Signed-off-by: NGao feng <gaofeng@cn.fujitsu.com>

Otherwise the container will fail to start if we
enable user namespace, since there is no rights to
do mknod in uninit user namespace.
Signed-off-by: NGao feng <gaofeng@cn.fujitsu.com>

lxc driver will use this function to change the owner
of hot added devices.

Move virLXCControllerChown to lxc_container.c and Rename
it to lxcContainerChown.
Signed-off-by: NGao feng <gaofeng@cn.fujitsu.com>

These disk devices are created for container,
the owner should be the root user of container.
Signed-off-by: NGao feng <gaofeng@cn.fujitsu.com>

Since mknod in container is forbidden, we should setup disks
on host side.
Signed-off-by: NGao feng <gaofeng@cn.fujitsu.com>

Convert the type of loop iterators named 'i', 'j', k',
'ii', 'jj', 'kk', to be 'size_t' instead of 'int' or
'unsigned int', also santizing 'ii', 'jj', 'kk' to use
the normal 'i', 'j', 'k' naming
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Many applications use /dev/tty to read from stdin.
e.g. zypper on openSUSE.

Let's create this device node to unbreak those applications.
As /dev/tty is a synonym for the current controlling terminal
it cannot harm the host or any other containers.
Signed-off-by: NRichard Weinberger <richard@nod.at>

Add some debug logging of LXC wait/continue messages
and uid/gid map update code.

These files are created for container,
the owner should be the root user of container.
Signed-off-by: NGao feng <gaofeng@cn.fujitsu.com>

Since these devices are created for the container.
the owner should be the root user of the container.
Signed-off-by: NGao feng <gaofeng@cn.fujitsu.com>

container will create /dev/pts directory in /dev.
the owner of /dev should be the root user of container.
Signed-off-by: NGao feng <gaofeng@cn.fujitsu.com>

Since these tty devices will be used by container,
the owner of them should be the root user of container.

This patch also adds a new function virLXCControllerChown,
we can use this general function to change the owner of
files.
Signed-off-by: NGao feng <gaofeng@cn.fujitsu.com>

user namespace doesn't allow to create devices in
uninit userns. We should create devices on host side.

We first mount tmpfs on dev directroy under state dir
of container. then create devices under this dev dir.

Finally in container, mount the dev directroy created
on host to the /dev/ directroy of container.
Signed-off-by: NGao feng <gaofeng@cn.fujitsu.com>

This patch introduces new helper function
virLXCControllerSetupUserns, in this function,
we set the files uid_map and gid_map of the init
task of container.

lxcContainerSetID is used for creating cred for
tasks running in container. Since after setuid/setgid,
we may be a new user. This patch calls lxcContainerSetUserns
at first to make sure the new created files belong to
right user.
Signed-off-by: NGao feng <gaofeng@cn.fujitsu.com>

Found with 'git grep "= 1"'.

The comments is for virLXCControllerSetupPrivateNS.
Signed-off-by: NGao feng <gaofeng@cn.fujitsu.com>

We forgot to free the mount_options.
Signed-off-by: NGao feng <gaofeng@cn.fujitsu.com>

After commit c131525b
"Auto-add a root <filesystem> element to LXC containers on startup"
for libvirt lxc, root must be existent.
Signed-off-by: NGao feng <gaofeng@cn.fujitsu.com>

The LXC driver can already configure <disk> or <filesystem>
devices to use the loop device. This extends it to also allow
for use of the NBD device, to support non-raw formats.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The current code for setting up loop devices to LXC disks first
does a switch() based on the disk format, then looks at the
disk driver name. Reverse this so it first looks at the driver
name, and then the disk format. This is more useful since the
list of supported disk formats depends on what driver is used.

The code for setting loop devices for LXC fs entries also needs
to have the same logic added, now the XML schema supports this.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The source code base needs to be adapted as well. Some files
include virutil.h just for the string related functions (here,
the include is substituted to match the new file), some include
virutil.h without any need (here, the include is removed), and
some require both.