Thanks to the testsuite, I feel quite confident that this rewrite
is correct; it gives the same results for all cases except for one.
I can make the argument that _that_ case was a pre-existing bug:
when looking up relative names, the lookup is supposed to be
pegged to the directory that contains the parent qcow2 file.  Thus,
this resolves the fixme first mentioned in commit 367cd69d (even
though I accidentally removed the fixme comment early in 74430fe3).

* src/util/virstoragefile.c (virStorageFileChainLookup): Depend on
new rather than old fields.
* tests/virstoragetest.c (mymain): Adjust test to match fix.
Signed-off-by: NEric Blake <eblake@redhat.com>

The original chain lookup code had to pass in the starting name,
because it was not available in the chain.  But now that we have
added fields to the struct, this parameter is redundant.

* src/util/virstoragefile.h (virStorageFileChainLookup): Alter
signature.
* src/util/virstoragefile.c (virStorageFileChainLookup): Adjust
handling of top of chain.
* src/qemu/qemu_driver.c (qemuDomainBlockCommit): Adjust caller.
* tests/virstoragetest.c (testStorageLookup, mymain): Likewise.
Signed-off-by: NEric Blake <eblake@redhat.com>

The chain lookup function was inconsistent on whether it left
a message in the log when looking up a name that is not found
on the chain (leaving a message for OOM or if name was
relative but not part of the chain), and could litter the log
even when successful (when name was relative but deep in the
chain, use of virFindBackingFile early in the chain would complain
about a file not found).  It's easier to make the function
consistently emit a message exactly once on failure, and to let
all callers rely on the clean semantics.

* src/util/virstoragefile.c (virStorageFileChainLookup): Always
report error on failure.  Simplify relative lookups.
* src/qemu/qemu_driver.c (qemuDomainBlockCommit): Avoid
overwriting error.
Signed-off-by: NEric Blake <eblake@redhat.com>

When checking if two filenames point to the same inode (whether
by hardlink or symlink), sometimes one of the names might be
relative.  This convenience function makes it easier to check.

* src/util/virfile.h (virFileRelLinkPointsTo): New prototype.
* src/util/virfile.c (virFileRelLinkPointsTo): New function.
* src/libvirt_private.syms (virfile.h): Export it.
* src/xen/xm_internal.c (xenXMDomainGetAutostart): Use it.
Signed-off-by: NEric Blake <eblake@redhat.com>

I realized that we had no good test coverage of looking up a
name from within a backing chain, even though code like
block-commit is relying on it.

* tests/virstoragetest.c (testStorageLookup): New function.
(mymain): New tests.
Signed-off-by: NEric Blake <eblake@redhat.com>

This uses the dbus api of systemd to check the power management
capabilities of the node.

Noticed while tweaking the RelaxNG grammar for <disk> elements.

* tests/qemuxml2xmloutdata/qemuxml2xmlout-numad-static-vcpu-no-numatune.xml:
* tests/qemuxml2xmloutdata/qemuxml2xmlout-disk-cdrom-empty.xml:
Drop unused files.
* tests/qemuargv2xmltest.c (testInfo, DO_TEST_FULL): Drop unused
field.
Signed-off-by: NEric Blake <eblake@redhat.com>

When domain is not persistent, it should be forgotten upon destroying.

Drop another redundant field from virStorageFileMetadata.

* src/util/virstoragefile.h (_virStorageFileMetadata): Drop
field.
* src/util/virstoragefile.c
(virStorageFileGetMetadataFromFDInternal)
(virStorageFileGetMetadataFromFD)
(virStorageFileGetMetadataRecurse): Adjust callers.
* tests/virstoragetest.c (_testFileData, testStorageChain)
(mymain): Simplify test.
Signed-off-by: NEric Blake <eblake@redhat.com>

A couple pieces of virStorageFileMetadata are used only while
collecting information about the chain, and don't need to
live permanently in the struct.  This patch refactors external
callers to collect the information separately, so that the
next patch can remove the fields.

* src/util/virstoragefile.h (virStorageFileGetMetadataFromBuf):
Alter signature.
* src/util/virstoragefile.c (virStorageFileGetMetadataInternal):
Likewise.
(virStorageFileGetMetadataFromFDInternal): Adjust callers.
* src/storage/storage_backend_fs.c (virStorageBackendProbeTarget):
Likewise.
* src/storage/storage_backend_gluster.c
(virStorageBackendGlusterRefreshVol): Likewise.
Signed-off-by: NEric Blake <eblake@redhat.com>

Finally starting to prune away some of the old fields that have
been made redundant by the new fields, on my way towards directly
reusing virStorageSource.

* src/util/virstoragefile.h (_virStorageFileMetadata): Drop
field.
* src/util/virstoragefile.c (virStorageFileGetMetadataInternal)
(virStorageFileChainLookup): Adjust callers.
* tests/virstoragetest.c (_testFileData, testStorageChain)
(mymain): Simplify test.
Signed-off-by: NEric Blake <eblake@redhat.com>

Deciding if a user string represents a local file instead of a
network path is an operation worth exposing directly, particularly
since the next patch will be removing a redundant variable that
was caching the information.

* src/util/virstoragefile.h (virStorageIsFile): New declaration.
* src/util/virstoragefile.c (virBackingStoreIsFile): Rename...
(virStorageIsFile): ...export, and allow NULL input.
(virStorageFileGetMetadataInternal)
(virStorageFileGetMetadataRecurse, virStorageFileGetMetadata):
Update callers.
* src/conf/domain_conf.c (virDomainDiskDefForeachPath): Use it.
* src/storage/storage_backend_fs.c (virStorageBackendProbeTarget):
Likewise.
* src/libvirt_private.syms (virstoragefile.h): Export function.
Signed-off-by: NEric Blake <eblake@redhat.com>

So far, my work has been merely preserving the status quo of
backing file analysis.  But this patch starts to tread in the
territory of making the backing chain code more powerful - we
will eventually support network storage containing non-raw
formats.  Here, we expose metadata information about a network
backing store, even if that information is still hardcoded to
a raw format for now.

* src/util/virstoragefile.c (virStorageFileGetMetadataRecurse):
Also populate struct for non-file backing.
(virStorageFileGetMetadata, virStorageFileGetMetadatainternal):
Recognize non-file top image.
(virFindBackingFile): Add comment.
(virStorageFileChainGetBroken): Adjust comment, ensure output
is set.
* tests/virstoragetest.c (mymain): Update test to reflect it.
Signed-off-by: NEric Blake <eblake@redhat.com>

I'm tired of alternating between test failures due to bugs in
my refactoring work, vs. test failures due to leftovers in
the file system from the previous test.  This patch has no
impact when the testsuite is successful, but doeesn't hurt either.

* tests/virstoragetest.c (testPrepImages): Clean up from prior
failed test.
Signed-off-by: NEric Blake <eblake@redhat.com>

Most of the APIs in CPU driver do not expect to get NULL for input
parameters. Let's mark them with ATTRIBUTE_NONNULL and also check for
some members of virCPUDef when the APIs expect them have some specific
values.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Every test that makes use of virmock.h (only virsystemdtest as of now)
needs to be linked with -export-dynamic to make sure the LD_PRELOADed
mock library can access its wrap_* symbols. Normally,
DRIVER_MODULE_LDFLAGS variable contains -export-dynamic but when
--without-driver-modules configure option is used, DRIVER_MODULE_LDFLAGS
is empty.

This patch turns on -export-dynamic for all tests unconditionally
regardless on --without-driver-modules. This fixes virsystemdtest and
all future users of virmock.h.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

My commit 897808e7 added a parameter to virCgroupGetPercpuStats,
but didn't change the stub for systems where cgroups are not supported.

The original comment of vshCmdInfo:
"name" - command name

Actually it's 'help' and the short description
of command, not the command name.
Signed-off-by: NLi Yang <liyang.fnst@cn.fujitsu.com>

The iterator is checked for being less than or equal to need_cpus.
The 'n' variable is incremented need_cpus + 1 times.

Simplify the computation of need_cpus and make its value one larger,
to let it be used instead of 'n' and compared without the equal sign
in loop conditions.

Just index the sum_cpu_time array instead of using a helper variable.

Start the loop at start_cpu instead of continuing for all lower values.

The cpus are indexed from 0, so a startcpu value equal
to the number of CPUs is invalid.

https://bugzilla.redhat.com/show_bug.cgi?id=1070680

total_cpus is the total number of CPUs on the host
need_cpus is the number of CPUs we need to look at

(need_cpus can be larger than ncpus, because we need to look
 at CPUs before the startcpu too, even if we aren't reporting
 their stats)

Currently, virCgroupGetPercpuStats is only used by the LXC driver,
filling out the CPUTIME stats. qemuDomainGetPercpuStats does this
and also filles out VCPUTIME stats.

Extend virCgroupGetPercpuStats to also report VCPUTIME stats if
nvcpupids is non-zero. In the LXC driver, we don't have cpupids.
In the QEMU driver, there is at least one cpupid for a running domain,
so the behavior shouldn't change for QEMU either.

Also rename getSumVcpuPercpuStats to virCgroupGetPercpuVcpuSum.

We need to return the number of successfully populated stats,
not the nparams supplied by the user.

All we need is the virCgroupPtr and number of vcpupids.
This will allow the function to be moved to util/vircgroup.c.

Validate that all the new fields are getting set to desired values.

* tests/virstoragetest.c (_testFileData, testStorageChain): Check
for more fields.
(mymain): Populate additional fields.
Signed-off-by: NEric Blake <eblake@redhat.com>

The testsuite is absolutely essential to feeling comfortable
about swapping the backing chain structure over to a new format.
This patch tests the path settings, and demonstrates that the
correct short name is being passed to the child.

* tests/virstoragetest.c (testStorageChain): Test path.
(mymain): Update expected data.
Signed-off-by: NEric Blake <eblake@redhat.com>

The current use of virStorageFileMetadata is awkward; to learn
some of the information about a child node, you have to read
fields in the parent node.  This does not lend itself well to
modifying backing chains (whether inserting a new node in the
chain, or consolidating existing nodes); better would be to
learn about a child node directly in that node.  This patch
sets up some new fields which contain redundant information,
although not necessarily in the final desired state for the
new fields (see the next patch for actual tests of what is there
now).  Then later patches will do any refactoring necessary to
get the fields to their desired states, and update clients to
get the information from the new fields, so we can finally
delete the fields that are tracking information about the wrong
node.

More concretely, compare these three example backing chains:

good <- one
missing <- two
gluster://server/vol/img <- three

Pre-patch, querying the chains gives:
{ .backingStore = "/path/to/good",
  .backingStoreRaw = "good",
  .backingStoreIsFile = true,
  .backingStoreFormat = VIR_STORAGE_FILE_RAW,
  .backingMeta = {
    .backingStore = NULL,
    .backingStoreRaw = NULL,
    .backingStoreIsFile = false,
    .backingMeta = NULL,
  }
}
{ .backingStore = NULL,
  .backingStoreRaw = "missing",
  .backingStoreIsFile = false,
  .backingStoreFormat = VIR_STORAGE_FILE_NONE,
  .backingMeta = NULL,
}
{ .backingStore = "gluster://server/vol/img",
  .backingStoreRaw = NULL,
  .backingStoreIsFile = false,
  .backingStoreFormat = VIR_STORAGE_FILE_RAW,
  .backingMeta = NULL,
}

Deciding whether to ignore a missing backing file (as in virsh
vol-dumpxml) or report an error (as in security manager sVirt
labeling) requires reading multiple fields.  Plus, the format
is hard-coded to treat all network protocols as end-of-the-chain,
as if they were raw.  By the end of this patch series, the goal
is to instead represent these three situations as:

{ .path = "one",
  .canonPath = "/path/to/one",
  .type = VIR_STORAGE_TYPE_FILE,
  .format = VIR_STORAGE_FILE_QCOW2,
  .backingStoreRaw = "good",
  .backingMeta = {
    .path = "good",
    .canonPath = "/path/to/good",
    .type = VIR_STORAGE_TYPE_FILE,
    .format = VIR_STORAGE_FILE_RAW,
    .backingStoreRaw = NULL,
    .backingMeta = NULL,
  }
}
{ .path = "two",
  .canonPath = "/path/to/two",
  .type = VIR_STORAGE_TYPE_FILE,
  .format = VIR_STORAGE_FILE_QCOW2,
  .backingStoreRaw = "missing",
  .backingMeta = NULL,
}
{ .path = "three",
  .canonPath = "/path/to/three",
  .type = VIR_STORAGE_TYPE_FILE,
  .format = VIR_STORAGE_FILE_QCOW2,
  .backingStoreRaw = "gluster://server/vol/img",
  .backingMeta = {
    .path = "gluster://server/vol/img",
    .canonPath = "gluster://server/vol/img",
    .type = VIR_STORAGE_TYPE_NETWORK,
    .format = VIR_STORAGE_FILE_RAW,
    .backingStoreRaw = NULL,
    .backingMeta = NULL,
  }
}

or, for the second file, maybe also allowing:
{ .path = "two",
  .canonPath = "/path/to/two",
  .type = VIR_STORAGE_TYPE_FILE,
  .format = VIR_STORAGE_FILE_QCOW2,
  .backingStoreRaw = "missing",
  .backingMeta = {
    .path = "missing",
    .canonPath = NULL,
    .type = VIR_STORAGE_TYPE_NONE,
    .format = VIR_STORAGE_FILE_NONE,
    .backingStoreRaw = NULL,
    .backingMeta = NULL,
  }
}

* src/util/virstoragefile.h (_virStorageFileMetadata): Add
path, canonPath, relDir, type, and format fields.  Reorder
existing fields, and add lots of comments.
* src/util/virstoragefile.c (virStorageFileFreeMetadata): Clean
new fields.
(virStorageFileGetMetadataInternal)
(virStorageFileGetMetadataFromFDInternal): Start populating new
fields.
Signed-off-by: NEric Blake <eblake@redhat.com>

A later patch will be adding some new fields to
virStorageFileMetadata; to minimize confusion, renaming the
test fields now will make it more obvious which fields are
being tested later.

* tests/virstoragetest.c (_testFileData): Alter names.
(testStorageChain, mymain): Adjust clients.
Signed-off-by: NEric Blake <eblake@redhat.com>

Right now, we are allocating virStorageFileMetadata near the bottom
of the callchain, only after we have identified that we are visiting
a file (and not a network resource).  I'm hoping to eventually
support parsing the backing chain from XML, where the backing chain
crawl then validates what was parsed rather than allocating a fresh
structure.  Likewise, I'm working towards a setup where we have a
backing element even for networks.  Both of these use cases are
easier to code if the allocation is hoisted earlier.

* src/util/virstoragefile.c (virStorageFileGetMetadataInternal)
(virStorageFileGetMetadataFromFDInternal): Change signature.
(virStorageFileGetMetadataFromBuf)
(virStorageFileGetMetadataRecurse, virStorageFileGetMetadata):
Update callers.
Signed-off-by: NEric Blake <eblake@redhat.com>

The previous patch started a separation of error messages
reported against the user-specified name, vs. tracking the
canonical path that was actually opened.  This patch extends
that notion, by hoisting directory detection up front, passing
the canonical path through the entire call chain, and
simplifying lower-level functions that can now assume that
a canonical path and directory have been supplied.

* src/util/virstoragefile.c
(virStorageFileGetMetadataFromFDInternal)
(virStorageFileGetMetadataInternal): Add parameter, require
directory.
(virFindBackingFile): Require directory.
(virStorageFileGetMetadataFromFD): Pass canonical path.
(virStorageFileGetMetadataFromBuf): Likewise.
(virStorageFileGetMetadata): Determine initial directory.
Signed-off-by: NEric Blake <eblake@redhat.com>

The function isn't used in any other file. Convert it to static.

Refactor the function to avoid multiple wrappers splitting identical
fields from the now common metadata struct.

The refactor is done by folding in the wrapper used for disk sources
which allows us to lookup secrets via the secret driver. This may allow
using stored secrets for snapshot disk images too in the future.

Now that we store all metadata about a storage image in a
virStorageSource struct let's use it also to store information needed by
the storage driver to access and do operations on the files.

Now that storage source metadata is stored in a single struct we don't
need two initialization functions for different structs.

Now that the storage source definition is uniform convert the helpers to
retrieve the actual storage type to a single one.

https://bugzilla.redhat.com/show_bug.cgi?id=1024159

If adding a volume to a storage pool fails during the CreateXML or
CreateXMLFrom API's, we don't want to adjust the available and
allocation values for the storage pool during storageVolDelete
since we haven't adjusted the values for the create.

Refactor storageVolDelete() a bit to create a storageVolDeleteInternal()
which will handle the primary deletion activities.  Add a parameter
updateMeta which will signify whether to update the values or not.

Adjust the calls from CreateXML and CreateXMLFrom to directly call the
DeleteInternal with the pool lock held.  This does bypass the call
to virStorageVolDeleteEnsureACL().

Introduced in commit d1e55de3.
virstoragetest.c: In function ‘testStorageChain’:
virstoragetest.c:249:10: warning: declaration of ‘abs’ shadows a global
declaration [-Wshadow]

As we can use virBhyveCapsBuild() now, replace
testBhyveBuildCapabilities() with it.

Another reduction in the number of structs I have to modify
when I start tracking new fields in virStorageFileMetadata.

* tests/virstoragetest.c (_testFileData): Add fields.
(testStorageChain): Select between fields based on flag.
(mymain): Record both absolute and relative expectations in one
struct.
Signed-off-by: NEric Blake <eblake@redhat.com>