If the virHashAddEntry fails, then we need to "careful" about
how we free the @vm. When virDomainObjNew returns there is one
reference and the object is locked, so use virDomainObjEndAPI
when done.

Add a virObjectRef in the error path for the second virHashAddEntry
call since it doesn't call virObjectRef, but virHashRemoveEntry
will call virObjectUnref because virObjectFreeHashData is called
when the element is removed from the hash table as set up in
virDomainObjListNew.

Eventually these paths should goto error and error should be changed
to use EndAPI as well, but that requires more adjustments to other
paths in the code to have a locked and ref counted @vm.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>

Use bool instead of an int.

Some failures of the post parse callback can be tolerated. This is
specifically desired when loading the configs of existing VMs. In such
case the post parse callback should not really be modifying anything
in the definition.

This patch adds a parse flag VIR_DOMAIN_DEF_PARSE_ALLOW_POST_PARSE_FAIL
which will allow the callbacks to report non-fatal failures by returning
a positive return value. In such case the field 'postParseFailed' in the
domain definition is set to true, to notify the drivers that the
callback failed and possibly needs to be re-run.

When dropping a domain report which one was dropped so that it's not
necessary to rummage through the logs.

Rather than overload virObjectUnlock as commit id '77f4593b' has
done, create a separate virObjectRWUnlock API that will force the
consumers to make the proper decision regarding unlocking the
RWLock's. Similar to the RWLockRead and RWLockWrite, use the
virObjectGetRWLockableObj helper. This restores the virObjectUnlock
code to using the virObjectGetLockableObj.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>

Instead of making virObjectLock be the entry point for two
different types of locks, let's create a virObjectRWLockWrite API
which will only handle the virObjectRWLockableClass objects.

Use the new virObjectRWLockWrite for the virdomainobjlist code
in order to handle the Add, Remove, Rename, and Load operations
that need to be very synchronous.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>

Since the class it represents is based on virObjectRWLockableClass
and in order to make sure we differentiate just in case anyone somehow
believes they could use virObjectLockRead for a virObjectLockableClass,
let's rename the API to use the RW in the name. Besides the RW locks
refer to pthread_rwlock_{init|rdlock|wrlock|unlock|destroy} while the
other locks refer to pthread_mutex_{init|lock|unlock|destroy}.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>

There is no reason why two threads trying to look up two domains
should mutually exclude each other. Utilize new
virObjectRWLockable that was just introduced.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NPavel Hrdina <phrdina@redhat.com>

While searching for an element using a function it may be
desirable to know the element key for future operation.
Signed-off-by: NPavel Hrdina <phrdina@redhat.com>
Reviewed-by: NJiri Denemark <jdenemar@redhat.com>

So far our code is full of the following pattern:

  dom = virGetDomain(conn, name, uuid)
  if (dom)
      dom->id = 42;

There is no reasong why it couldn't be just:

  dom = virGetDomain(conn, name, uuid, id);

After all, client domain representation consists of tuple (name,
uuid, id).
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

We want to pass the proper opaque pointer instead of NULL to
virDomainDefParse and subsequently virDomainDefParseNode too.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Use it instead of opendir everywhere we need to check for ENOENT.

This fixes the disappearance of domains and networks starting with a
dot.

https://bugzilla.redhat.com/show_bug.cgi?id=1333248

Introduce a helper that only calls closedir if DIR* is non-NULL
and sets it to NULL afterwards.

In libxl driver we do virObjectRef in libxlDomainObjBeginJob,
If virCondWaitUntil failed, it goes to error, do virObjectUnref,
There's a chance that someone undefine the vm at the same time,
and refs unref to zero, vm is freed in libxlDomainObjBeginJob.
But the vm outside function is not Null, we do virObjectUnlock(vm).
That's how we overwrite the vm memory after it's freed. I fix it.
Signed-off-by: NWang Yufei <james.wangyufei@huawei.com>
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Until now we weren't able to add checks that would reject configuration
once accepted by the parser. This patch adds a new callback and
infrastructure to add such checks. In this patch all the places where
rejecting a now-invalid configuration wouldn't be a good idea are marked
with a new parser flag.

Our existing virHashForEach method iterates through all items disregarding the
fact, that some of the iterators might have actually failed. Errors are usually
dispatched through an error element in opaque data which then causes the
original caller of virHashForEach to return -1. In that case, virHashForEach
could return as soon as one of the iterators fail. This patch changes the
iterator return type and adjusts all of its instances accordingly, so the
actual refactor of virHashForEach method can be dealt with later.
Signed-off-by: NErik Skultety <eskultet@redhat.com>

A pretty nasty deadlock occurs while trying to rename a VM in parallel
with virDomainObjListNumOfDomains.
The short description of the problem is as follows:

Thread #1:

qemuDomainRename:
    ------> aquires domain lock by qemuDomObjFromDomain
       ---------> waits for domain list lock in any of the listed functions:
          - virDomainObjListFindByName
          - virDomainObjListRenameAddNew
          - virDomainObjListRenameRemove

Thread #2:

virDomainObjListNumOfDomains:
    ------> aquires domain list lock
       ---------> waits for domain lock in virDomainObjListCount

Introduce generic virDomainObjListRename function for renaming domains.
It aquires list lock in right order to avoid deadlock. Callback is used
to make driver specific domain updates.
Signed-off-by: NNikolay Shirokovskiy <nshirokovskiy@virtuozzo.com>
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Our domain_conf.* files are big enough. Not only they contain XML
parsing code, but they served as a storage of all functions whose
name is virDomain prefixed. This is just wrong as it gathers not
related functions (and modules) into one big file which is then
harder to maintain. Split virDomainObjList module into a separate
file called virdomainobjlist.[ch].
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>