Add VIR_STORAGE_VOL_CREATE_PREALLOC_METADATA flag to virStorageVolCreateXML
and virStorageVolCreateXMLFrom. This flag requests metadata
preallocation when creating/cloning qcow2 images, resulting in creating
a sparse file with qcow2 metadata. It has only slightly larger disk usage
compared to new image with no allocation, but offers higher performance.

Pushed under trivial rule.

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: NDaniel P. Berrange <berrange@redhat.com>

Rename the 'wait' parameter to 'loop'.
This silences the warning:
storage/storage_backend.c:1348:34: error: declaration of 'wait' shadows
a global declaration [-Werror=shadow]
and fixes the build with -Werror.
--
Note: loop is pool backwards.

virStorageVolLookupByPath is an API call that virt-manager uses
quite a bit when dealing with storage. This call use BackendStablePath
which has several usleep() heuristics that can be tripped up
and hang virt-manager for a while.

Current example: an empty mpath pool pointing to /dev/mapper makes
_any_ calls to virStorageVolLookupByPath take 5 seconds.

The sleep heuristics are actually only needed in certain cases
when we are waiting for new storage to appear, so let's skip the
timeout steps when calling from LookupByPath.

We are currently able to work only with non-translated SELinux
contexts, but we are using functions that work with translated
contexts throughout the code.  This patch swaps all SELinux context
translation relative calls with their raw sisters to avoid parsing
problems.

The problems can be experienced with mcstrans for example.  The
difference is that if you have translations enabled (yum install
mcstrans; service mcstrans start), fgetfilecon_raw() will get you
something like 'system_u:object_r:virt_image_t:s0', whereas
fgetfilecon() will return 'system_u:object_r:virt_image_t:SystemLow'
that we cannot parse.

I was trying to confirm that the _raw variants were here since the dawn of
time, but the only thing I see now is that it was imported together in
the upstream repo [1] from svn, so before 2008.

Thanks Laurent Bigonville for finding this out.

[1] http://oss.tresys.com/git/selinux.git

It might need some time till the LUN's stable path shows up on
initiator host, and although the time window is not foreseeable,
as a better than nothing fix, this patch adds timeout for the
stable path discovery process.

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/

Otherwise, in locations like virobject.c where PROBE is used,
for certain configure options, the compiler warns:

util/virobject.c:110:1: error: 'intptr_t' undeclared (first use in this function)

As long as we are making this header always available, we can
clean up several other files.

* src/internal.h (includes): Pull in <stdint.h>.
* src/conf/nwfilter_conf.h: Rely on internal.h.
* src/storage/storage_backend.c: Likewise.
* src/storage/storage_backend.h: Likewise.
* src/util/cgroup.c: Likewise.
* src/util/sexpr.h: Likewise.
* src/util/virhashcode.h: Likewise.
* src/util/virnetdevvportprofile.h: Likewise.
* src/util/virnetlink.h: Likewise.
* src/util/virrandom.h: Likewise.
* src/vbox/vbox_driver.c: Likewise.
* src/xenapi/xenapi_driver.c: Likewise.
* src/xenapi/xenapi_utils.c: Likewise.
* src/xenapi/xenapi_utils.h: Likewise.
* src/xenxs/xenxs_private.h: Likewise.
* tests/storagebackendsheepdogtest.c: Likewise.

The access, birth, modification and change times are added to
storage volumes and corresponding xml representations.  This
shows up in the XML in this format:

<timestamps>
  <atime>1341933637.027319099</atime>
  <mtime>1341933637.027319099</mtime>
</timestamps>
Signed-off-by: NEric Blake <eblake@redhat.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

This patch brings support to manage sheepdog pools and volumes to libvirt.
It uses the "collie" command-line utility that comes with sheepdog for that.

A sheepdog pool in libvirt maps to a sheepdog cluster.
It needs a host and port to connect to, which in most cases
is just going to be the default of localhost on port 7000.

A sheepdog volume in libvirt maps to a sheepdog vdi.
To create one specify the pool, a name and the capacity.
Volumes can also be resized later.

In the volume XML the vdi name has to be put into the <target><path>.
To use the volume as a disk source for virtual machines specify
the vdi name as "name" attribute of the <source>.
The host and port information from the pool are specified inside the host tag.

  <disk type='network'>
    ...
    <source protocol="sheepdog" name="vdi_name">
      <host name="localhost" port="7000"/>
    </source>
  </disk>

To work right this patch parses the output of collie,
so it relies on the raw output option. There recently was a bug which caused
size information to be reported wrong. This is fixed upstream already and
will be in the next release.
Signed-off-by: NSebastian Wiedenroth <wiedi@frubar.net>

Update the storage driver to use virReportError instead of
the virStorageReportError custom macro
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

To make it easier to dynamically change the command line ARGV,
switch all storage code over to use virCommandPtr APIs for
running programs
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

This patch adds support for a new storage backend with RBD support.

RBD is the RADOS Block Device and is part of the Ceph distributed storage
system.

It comes in two flavours: Qemu-RBD and Kernel RBD, this storage backend only
supports Qemu-RBD, thus limiting the use of this storage driver to Qemu only.

To function this backend relies on librbd and librados being present on the
local system.

The backend also supports Cephx authentication for safe authentication with
the Ceph cluster.

For storing credentials it uses the built-in secret mechanism of libvirt.
Signed-off-by: NWido den Hollander <wido@widodh.nl>

Input to the volume cloning code is a source volume and an XML
descriptor for the new volume. It is possible for the new volume
to have a greater size than source volume, at which point libvirt
will just stick 0s on the end of the new image (for raw format
anyways).

Unfortunately a logic error messed up our tracking of the of the
excess amount that needed to be written: end result is that sparse
clones were made very much non-sparse, and cloning regular disk
images could end up excessively sized (though data unaltered).

Drop the 'remain' variable entriely here since it's redundant, and
track actual allocation directly against the desired 'total'.

virFileOpenAs previously would only try opening a file as the current
user, or as a different user, but wouldn't try both methods in a
single call. This made it cumbersome to use as a replacement for
open(2). Additionally, it had a lot of historical baggage that led to
it being difficult to understand.

This patch refactors virFileOpenAs in the following ways:

* reorganize the code so that everything dealing with both the parent
  and child sides of the "fork+setuid+setgid+open" method are in a
  separate function. This makes the public function easier to understand.

* Allow a single call to virFileOpenAs() to first attempt the open as
  the current user, and if that fails to automatically re-try after
  doing fork+setuid (if deemed appropriate, i.e. errno indicates it
  would now be successful, and the file is on a networkFS). This makes
  it possible (in many, but possibly not all, cases) to drop-in
  virFileOpenAs() as a replacement for open(2).

  (NB: currently qemuOpenFile() calls virFileOpenAs() twice, once
  without forking, then again with forking. That unfortunately can't
  be changed without at least some discussion of the ramifications,
  because the requested file permissions are different in each case,
  which is something that a single call to virFileOpenAs() can't deal
  with.)

* Add a flag so that any fchown() of the file to a different uid:gid
  is explicitly requested when the function is called, rather than it
  being implied by the presence of the O_CREAT flag. This just makes
  for less subtle surprises to consumers. (Commit
  b1643dc1 added the check for O_CREAT
  before forcing ownership. This patch just makes that restriction
  more explicit.)

* If either the uid or gid is specified as "-1", virFileOpenAs will
  interpret this to mean "the current [gu]id".

All current consumers of virFileOpenAs should retain their present
behavior (after a few minor changes to their setup code and
arguments).

On F16 at least, empty volume groups don't have a directory under /dev.
The directory only appears once a logical volume is created.

This tickles some behavior in BackendStablePath which ends with
libvirt sleeping for 5 seconds while waiting for the directory to appear.
This causes all sorts of problems for the virStorageVolLookupByPath API
which virtinst uses, even if trying to resolve a path that is independent
of the logical pool.

In reality we don't even need to do that checking since logical pools
always have a stable target path. Short circuit the polling in that
case.

Fixes bug 782261

This partly reverts my previous patch f88de3eb. We need to
get file status after open, as given path could have been symlink,
so fstat() will operate on different file than lstat().

If pool directory contains special files like FIFO or sockets
we want to skip those on pool-start or pool-refresh otherwise
open() will get an error.

Detected by Coverity.  Only possible if qemu-img gives bogus output,
but we might as well be robust.

* src/storage/storage_backend.c
(virStorageBackendQEMUImgBackingFormat): Check for strstr failure.

If the regexes supported (?:pvs)?, then we could handle this by
optionally matching but not returning the initial command name.  But it
doesn't.  So add a new char* argument to
virStorageBackendRunProgRegex().  If that argument is NULL then we act
as usual.  Otherwise, if the string at that argument is found at the
start of a returned line, we drop that before running the regex.

With this patch, virt-manager shows me lvs with command_names 1 or 0.

The definitions of PVS_BASE etc may want to be moved into the configure
scripts (though given how PVS is found, IIUC that could only happen if
pvs was a link to pvs_real), but in any case no sense dealing with that
until we're sure this is an ok way to handle it.
Signed-off-by: NSerge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

Commit 0376f4a6 intended to fix incorrect use of VIR_ERR_NO_SUPPORT,
but replacing it with VIR_ERR_OPERATION_INVALID is not proper either.

Although we are flushing cache after some critical writes (e.g.
volume creation), after some others we do not (e.g. volume cloning).
This patch fix this issue. That is for volume cloning, writing
header of logical volume, and storage wipe.

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.

* src/storage/storage_backend.c (virStorageBackendCreateBlockFrom)
(virStorageBackendCreateQemuImg)
(virStorageBackendCreateQcowCreate): Reject unknown flags.
* src/storage/storage_backend_disk.c (virStorageBackendDiskBuildPool)
(virStorageBackendDiskDeleteVol): Likewise.
* src/storage/storage_backend_fs.c
(virStorageBackendFileSystemNetFindPoolSources)
(virStorageBackendFileSystemBuild)
(virStorageBackendFileSystemDelete, createFileDir)
(virStorageBackendFileSystemVolBuildFrom)
(virStorageBackendFileSystemVolDelete): Likewise.
* src/storage/storage_backend_iscsi.c
(virStorageBackendISCSIFindPoolSources): Likewise.
* src/storage/storage_backend_logical.c
(virStorageBackendLogicalFindPoolSources)
(virStorageBackendLogicalBuildPool)
(virStorageBackendLogicalDeletePool)
(virStorageBackendLogicalDeleteVol): Likewise.
* src/storage/storage_driver.c (storageOpen, storagePoolCreate)
(storagePoolDefine, storagePoolRefresh, storagePoolGetXMLDesc)
(storageVolumeCreateXML, storageVolumeCreateXMLFrom)
(storageVolumeGetXMLDesc): Likewise.

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.

virStorageBackendCreateRaw: createRawFile already reported the
exact error.

Before the fix:

error: Failed to create vol vol-create.img
error: cannot create path '/var/lib/libvirt/images/vol-create.img': Unknown error 18446744073709551597

After the fix:

error: Failed to create vol vol-create.img
error: cannot fill file '/var/lib/libvirt/images/vol-create.img': No space left on device

Most of the safezero() implementations return -1 on error,
setting errno. The safezero() impl using posix_fallocate()
though returned a positive errno value on error (due to
the unusual API contract of posix_fallocate() compared to
most syscall APIs).

* src/util/util.c: Ensure safezero() returns -1 and sets
  errno on error.
* src/storage/storage_backend.c: Change safezero != 0 to
  < 0 for detecting errors

Suggested here:
https://www.redhat.com/archives/libvir-list/2011-May/msg00594.html

* src/storage/storage_backend.c (virStorageBackendCreateQemuImg):
Generate size inline.

Since directories can be used for <filesystem> passthrough, they are
basically storage volumes.

v2:
    Skip ., .., lost+found dirs

v3:
    Use gnulib last_component

v4:
    Use gnulib "dirname.h", not system <dirname.h>
    Don't skip lost+found

Two additional places need initgroups call to properly work in an
environment where the UID is allowed to open/create stuff through its
supplementary groups.

Commit d7b26792 introduced
a return value picking of qemu-img on '-h', but without any comment.

qemu-img returns non-zero status on -h. Therefore we need to
provide virCommandRun() a non-NULL exit status pointer.