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>

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>

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>

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

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>

As I add more tests, it's getting harder to follow the split between
a struct in one place and a test using the struct in another.
Interleaving the tests makes changes more localized, and also makes
debugging easier when a test goes wrong during my refactoring work.

* tests/virstoragetest.c (mymain): Modify structs as we go, rather
than up-front.
(testStorageChain): Make failure debugging easier.
Signed-off-by: NEric Blake <eblake@redhat.com>

Part of the upcoming refactoring will change how broken chains
are detected; it makes sense to test that this works.  In
particular, test the just-fixed infinite loop detection bug.
Also, make sure that detection of directories is sane.

* tests/virstoragetest.c (testStorageChain): Enhance test.
(mymain): Add more tests.
(testCleanupImages, testPrepImages): Populate a directory.
Signed-off-by: NEric Blake <eblake@redhat.com>

I'm about to add fields to virStorageFileMetadata, which means
also adding fields to the testFileData struct in virstoragetest.
Alas, adding even one pointer on an x86_64 machine gave me a
dreaded compiler error:

virstoragetest.c:712:1: error: the frame size of 4208 bytes is larger than 4096 bytes [-Werror=frame-larger-than=]

After some experimentation, I realized that each test was creating
yet another testChainData (which contains testFileData) on the stack;
forcing the reuse of one of these structures instead of creating a
fresh one each time drastically reduces the size requirements.  While
at it, I also got rid of a lot of intermediate structs, with some
macro magic that lets me directly build up the destination chains
inline.

For a bit more insight into what this patch does:
The old code uses an intermediate variable as a fixed-size array
of structs:
testFileData chain[] = { a, b };
data.files = chain;

In the new code, the use of VIR_FLATTEN_* allows the TEST_CHAIN()
macro to still take a single argument for each chain, but now of
the form '(a, b)', where it is turned into the var-args 'a, b'
multiple arguments understood by TEST_ONE_CHAIN().  Thus, the
new code avoids an intermediate variable, and directly provides
the list of pointers to be assigned into array elements:
data.files = { &a, &b };

* tests/virstoragetest.c (mymain): Rewrite TEST_ONE_CHAIN to
reuse the same struct for each test, and to take the data
inline rather than via intermediate variables.
(testChainData): Use bounded array of pointers instead of
unlimited array of struct.
(testStorageChain): Reflect struct change.
Signed-off-by: NEric Blake <eblake@redhat.com>

Writing this test with C99 initializers will make it easier to test
additions and deletions to struct members as I refactor the code.

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

No need to spawn a child 'rm' process when we can do it ourselves.

* tests/virstoragetest.c (testCleanupImages): Use dedicated
helper.
Signed-off-by: NEric Blake <eblake@redhat.com>

A future patch will merge virStorageFileMetadata and virStorageSource,
but I found it easier to do if both structs use the same information
for tracking whether a source file needs encryption keys.

* src/util/virstoragefile.h (_virStorageFileMetadata): Prepare
full encryption struct instead of just a bool.
* src/storage/storage_backend_fs.c (virStorageBackendProbeTarget):
Use transfer semantics.
* src/storage/storage_backend_gluster.c
(virStorageBackendGlusterRefreshVol): Likewise.
* src/util/virstoragefile.c (virStorageFileGetMetadataInternal):
Populate struct.
(virStorageFileFreeMetadata): Adjust clients.
* tests/virstoragetest.c (testStorageChain): Likewise.
Signed-off-by: NEric Blake <eblake@redhat.com>

Any source file which calls the logging APIs now needs
to have a VIR_LOG_INIT("source.name") declaration at
the start of the file. This provides a static variable
of the virLogSource type.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

While working on v1.0.5-maint (the branch in use on Fedora 19)
with the host at Fedora 20, I got a failure in virstoragetest.
I traced it to the fact that we were using qemu-img to create a
qcow2 file, but qemu-img changed from creating v2 files by
default in F19 to creating v3 files in F20.  Rather than leaving
it up to qemu-img, it is better to write the test to force
testing of BOTH file formats (better code coverage and all).

This patch alone does not fix all the failures in v1.0.5-maint;
for that, we must decide to either teach the older branch to
understand v3 files, or to reject them outright as unsupported.
But for upstream, making the test less dependent on changing
qemu-img defaults is always a good thing.

* tests/virstoragetest.c (testPrepImages): Simplify creation of
raw file; check if qemu supports compat and if so use it.
Signed-off-by: NEric Blake <eblake@redhat.com>

The test case average timing code has not been used by any test
case ever. Delete it to remove complexity.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.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>

These all existed before virfile.c was created, and for some reason
weren't moved.

This is mostly straightfoward, although the syntax rule prohibiting
write() had to be changed to have an exception for virfile.c instead
of virutil.c.

This movement pointed out that there is a function called
virBuildPath(), and another almost identical function called
virFileBuildPath(). They really should be a single function, which
I'll take care of as soon as I figure out what the arglist should look
like.

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.

On Win32 symlink() is not available, so virstoragetest.c
must be conditionalized to avoid compile failures.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

virstoragetest was failing on RHEL 5, but with no good error message:

TEST: virstoragetest
                                        0   FAIL

It turns out that qemu-img was so old, that it lacked support for
-o backing_file.  It didn't help that the test was also using
qemu-img from PATH, even after first probing for kvm-img.

* tests/virstoragetest.c (testPrepImages): Consistently use
discovered binary.  Skip instead of fail if qemu-img fails during
setup.

On RHEL 5, I noticed this test failure message:

TEST: qemumonitorjsontest
libvirt not compiled with yajl, skippingSKIP: qemumonitorjsontest

* tests/virstoragetest.c (testPrepImages): Use simpler fputs.
* tests/qemumonitorjsontest.c (mymain): Ensure trailing newline.

Testing our backing chain handling will make it much easier to
ensure that we avoid issues in the future.  If only I had written
this test before I first caused several regressions...

* tests/virstoragetest.c: New test.
* tests/Makefile.am (test_programs): Build it.
* .gitignore: Ignore new files.