Create a helper virStorageBackendCreateQemuImgSetBacking to perform the
backing store set
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>

Since we support QEMU 0.12 and later, checking for support of specific flags
added prior to that isn't necessary.

Thus start with the base of having the "-o options" available for the
qemu-img create option and then determine whether we have the compat
option for qcow2 files (which would be necessary up through qemu 2.0
where the default changes to compat 0.11).

Adjust test to no long check for NONE and FLAG options as well was removing
results of tests that would use that option.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>

Create helper virStorageBackendCreateQemuImgSetInput to set the input
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>

Split out a helper from virStorageBackendCreateQemuImgCmdFromVol
to check the encryption - soon a new encryption sheriff will be
patroling and that'll mean all sorts of new checks.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>

Change 'ephemeral' to 'isephemeral' and 'private' to 'isprivate' since
both are bools.

Remove all the plumbing needed for the different qcow-create/kvm-img
non-raw file creation.

We can drop the error messages because CreateQemuImg will thrown an
error for us but with slightly less fidelity (unable to find qemu-img),
which I think is acceptable given the unlikeliness of that error in
practice.

This an ubuntu/debian packaging convention. At one point it may have
been an actually different binary, but at least as of ubuntu precise
(the oldest supported ubuntu distro, released april 2012) kvm-img is
just a symlink to qemu-img for back compat.

I think it's safe to drop support for it

qcow-create was a crippled qemu-img impl that shipped with xen. I
think supporting this was only relevant for really old distros
that didn't have a proper qemu package, like early RHEL5. I think
it's fair to drop support

In case of ploop volume, target path of the volume is the path to the
directory that contains image file named root.hds and DiskDescriptor.xml.
While using uploadVol and downloadVol callbacks we need to open root.hds
itself.
Upload or download operations with ploop volume are only allowed when
images do not have snapshots. Otherwise operation fails.
Signed-off-by: NOlga Krishtal <okrishtal@virtuozzo.com>
Signed-off-by: NJán Tomko <jtomko@redhat.com>

Refreshes meta-information such as allocation, capacity, format, etc.
Ploop volumes differ from other volume types. Path to volume is the path
to directory with image file root.hds and DiskDescriptor.xml.
https://openvz.org/Ploop/format
Due to this fact, operations of opening the volume have to be done once
again. get the information.

To decide whether the given volume is ploops one, it is necessary to check
the presence of root.hds and DiskDescriptor.xml files in volumes' directory.
Only in this case the volume can be manipulated as the ploops one.
Such strategy helps us to resolve problems that might occure, when we
upload some other volume type from ploop source.
Signed-off-by: NOlga Krishtal <okrishtal@virtuozzo.com>
Signed-off-by: NJán Tomko <jtomko@redhat.com>

Returns error in case of vol-wipe cmd for a ploop volume
Signed-off-by: NOlga Krishtal <okrishtal@virtuozzo.com>

Changes the size of given ploop volume via ploop resize tool.
Signed-off-by: NOlga Krishtal <okrishtal@virtuozzo.com>

These callbacks let us to create ploop volumes in dir, fs and etc. pools.
If a ploop volume was created via buildVol callback, then this volume
is an empty ploop device with DiskDescriptor.xml.
If the volume was created via .buildFrom - then its content is similar to
input volume content.
Signed-off-by: NOlga Krishtal <okrishtal@virtuozzo.com>
Signed-off-by: NJán Tomko <jtomko@redhat.com>

Do not store the return value of called functions in the same variable
as the (future) return value of the current function.

This makes tracking the origin of the value easier and reduces
the chance of introducing a new point of exit without resetting
the return value back to -1.

This new algorithm adds support for wiping volumes using TRIM.

It does not overwrite all the data in a volume, but it tells the
backing storage pool/driver that all bytes in a volume can be
discarded.

It depends on the backing storage pool how this is handled.

A SCSI backend might send UNMAP commands to remove all data present
on a LUN.

A Ceph backend might use rbd_discard() to instruct the Ceph cluster
that all data on that RBD volume can be discarded.
Signed-off-by: NWido den Hollander <wido@widodh.nl>

Use the cast of (virStorageVolWipeAlgorithm) adding the missing case:'s
(VIR_STORAGE_VOL_WIPE_ALG_ZERO and VIR_STORAGE_VOL_WIPE_ALG_LAST).

Additionally, the old code would also still run the SCRUB command on
default since it didn't go to cleanup when a invalid flag was supplied.
We now go to cleanup and exit if a invalid flag would be provided.
Signed-off-by: NWido den Hollander <wido@widodh.nl>

It is not used by the caller.

The only caller always passes 0 for the extent start.
Drop the 'extent_start' parameter, as well as the mention of extents
from the function name.

Change off_t extent_length to unsigned long long wipe_len, as well as the
'remain' variable.

We do not need to pass a zero-filled buffer as an argument,
the function can allocate its own.

Return -1:
* on all failures of fdatasync. Instead of propagating -errno
  all the way up to the virStorageVolWipe API, which is documented
  to return 0 or -1.
* after a partial wipe. If safewrite failed, we would re-use the
  non-negative return value of lseek (which should be 0 in this case,
  because that's the only offset we seek to).

I found this useful while processing a volume that wouldn't end up
showing up in the resulting list of block volumes. In this case, the
partition type wasn't found in the disk_types table.

Similar to the openflags VIR_STORAGE_VOL_OPEN_NOERROR processing, if some
read processing operation fails, check the readflags for the corresponding
error flag being set. If so, rather then causing an error - use VIR_WARN
to flag the error, but return -2 which some callers can use to perform
specific actions. Use a new VIR_STORAGE_VOL_READ_NOERROR flag in a new
VolReadErrorMode enum.

While processing the volume for lseek, virFileReadHeaderFD, and
virStorageFileGetMetadataFromBuf - failure would cause an error,
but ret would not be set. That would result in an error message being
sent, but successful status being returned.

Just so it's clearer what to expect upon input and what types of return
values could be generated.  These were loosely copied from existing
virStorageBackendUpdateVolTargetInfoFD.

Similar to the openflags which allow VIR_STORAGE_VOL_OPEN_NOERROR to be
passed to avoid open errors, add a 'readflags' variable so that in the
future read failures could also be ignored.

https://bugzilla.redhat.com/show_bug.cgi?id=1282288

Rather than using just open on the path, allow for the possibility that
the path to be opened resides on an NFS root-squash target and was created
under a different uid/gid.

Without using virFileOpenAs an attempt to get the volume size data may fail
if the current user doesn't have permissions to read the volume, such as
would be the case if mode wasn't supplied in the volume XML and the default
VIR_STORAGE_DEFAULT_VOL_PERM_MODE (e.g. 0600) was used. Under this scenario
the owner/group is not root:root, thus this path run under root would fail
to open/read the volume.

NB: The virFileOpenAs code using OPEN_FORK will only work when the failure
is not EACESS/EPERM and the path resolves to a shared file system.

https://bugzilla.redhat.com/show_bug.cgi?id=1282288

Although commit id '77346f27' resolves part of the problem regarding creating
a qemu-img image in an NFS root-squash environment, it really didn't fix the
entire problem. Unfortunately it only masked the problem. It seems qemu-img
must open/create the image using 0644, which if used by target.perms would
result in the chmod not being called since the mode desired and set match.

Although qemu-img could conceivably ignore the mode when creating, libvirt
has more knowledge of the environment and can make the adjustment to the
mode far more easily by using virFileOpenAs with VIR_FILE_OPEN_FORCE_MODE.
If that's successful, then we know on return the file will have the right
owner and mode, so we can declare success

After successfully returning from virFileOpenAs, if subsequent calls fail,
then we need to remove the file since our caller expects that failures after
creation will remove the created file.

After a successful qemu-img/qcow-create of the backing file, if we
fail to stat the file, change it owner/group, or mode, then the
cleanup path should remove the file.

Currently the code does not handle the NFS root squash environment
properly since if the file gets created, then the subsequent chmod
will fail in a root squash environment where we're creating a file
in the pool with qemu tools, such as seen via:

   $ virsh vol-create-from $pool $file.xml file.img --inputpool $pool

assuming $file.xml is creating a file of "<format type='qcow2'"> from
an existing file.img in the pool of "<format type='raw'>".

This patch will utilize the virCommandSetUmask when creating the file
in the NETFS pool. The virCommandSetUmask API was added in commit id
'0e1a1a8c', which was after the original code was developed in commit
id 'e1f27784' to attempt to handle the root squash environment.

Also, rather than blindly attempting to chmod, check to see if the
st_mode bits from the stat match what we're trying to set and only
make the chmod if they don't.

Also, a slight adjustment to the fallback algorithm to move the
virCommandSetUID/virCommandSetGID inside the if (!filecreated) since
they're only useful if we need to attempt to create the file again.

Rework the code in order to use the "ret = -1;" and goto cleanup;
coding style.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>

Cleanup calls to virStorageBackendCopyToFD a bit.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>

Commit id '7c2d65dd' changed the default value of mode to be -1 if not
supplied in the XML, which should cause creation of the volume using the
default mode of VIR_STORAGE_DEFAULT_VOL_PERM_MODE; however, the check
made was whether mode was '0' or not to use default or provided value.

This patch fixes the issue to check if the 'mode' was provided in the XML
and use that value.

While a zero allocation in safezero should be fine it isn't when we use
posix_fallocate which returns EINVAL on a zero allocation.

While we could skip the zero allocation in safezero_posix_fallocate it's
an optimization to do it for all allocations.

This fixes vm installation via virtinst for me which otherwise aborts
like:

   Starting install...
   Retrieving file linux...               | 5.9 MB     00:01 ...
   Retrieving file initrd.gz...           |  29 MB     00:07 ...
   ERROR    Couldn't create storage volume 'virtinst-linux.sBgds4': 'cannot fill file '/var/lib/libvirt/boot/virtinst-linux.sBgds4': Invalid argument'

The error was introduced by e30297b0 as spotted by Chunyan Liu

In commit 155ca616, a change was introduced that no longer allowed defining
volumes via XML with a capacity of '0'. Because we check for info.size_arg
to be non-zero, this use-case fails. This patch allows info.size_arg to be
zero if no backing store is specified.
Signed-off-by: NChris J Arges <chris.j.arges@canonical.com>

When virsh vol-clone is attempted on a raw file where capacity > allocation,
the resulting cloned volume has a size that matches the virtual-size of
the parent; in place of matching its actual, disk size.
This patch fixes the cloned disk to have same _allocated_size_ as
the parent file from which it was cloned.

Ref: http://www.redhat.com/archives/libvir-list/2015-May/msg00050.html

Also fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1130739Signed-off-by: NPrerna Saxena <prerna@linux.vnet.ibm.com>
Signed-off-by: NJán Tomko <jtomko@redhat.com>

Instead of storing the remaining bytes, store the position of the first
unallocated byte. This will allow changing the amount of bytes copied
by virStorageBackendCopyToFD without changing the safezero call.

No functional impact.

The XML parser sets a default <mode> if none is explicitly passed in.
This is then used at pool/vol creation time, and unconditionally reported
in the XML.

The problem with this approach is that it's impossible for other code
to determine if the user explicitly requested a storage mode. There
are some cases where we want to make this distinction, but we currently
can't.

Handle <mode> parsing like we handle <owner>/<group>: if no value is
passed in, set it to -1, and adjust the internal consumers to handle
it.

Trying to use qemu:///session to create a storage pool pointing at
/tmp will usually fail with something like:

$ virsh pool-start tmp
error: Failed to start pool tmp
error: cannot open volume '/tmp/systemd-private-c38cf0418d7a4734a66a8175996c384f-colord.service-kEyiTA': Permission denied

If any volume in an FS pool can't be opened by the daemon, the refresh
fails, and the pool can't be used.

This causes pain for virt-install/virt-manager though. Imaging a user
downloads a disk image to /tmp. virt-manager wants to import /tmp as
a storage pool, so we can detect what disk format it is, and set the
XML correctly. However this case will likely fail as explained above.

Change the logic here to skip volumes that fail to open. This could
conceivably cause user complaints along the lines of 'why doesn't
libvirt show $ROOT-OWNED-VOLUME-FOO', but figuring that currently
the pool won't even startup, I don't think there are any current
users that care about that case.

https://bugzilla.redhat.com/show_bug.cgi?id=1103308

Fix the if (!STRPREFIX(path, "/dev")) to be if (!STRPREFIX(path, "/dev/"))
to ensure a path such as "/device" isn't declared stable.