The HTML pages are currently validated against an XHTML 1.0 DTD.
This makes it impossible to take advantage of features that are
introduced in HTML 5, because they'll fail validation.
There is intentionally no DTD defined for HTML 5, so there's no
alternative to XHTML 1.0 DTD that we could switch to. The only
options are to stick with XHTML 1.0 forever, or drop the DTD
validation, and we pick the latter.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
docs: switch to using 'id' attribute instead of 'name' for links
The 'name' attribute on <a...> elements is deprecated in favour
of the 'id' attribute which is allowed on any element. HTML5
drops 'name' support entirely.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Ján Tomko [Tue, 27 Jun 2017 14:33:22 +0000 (16:33 +0200)]
conf: check for buffer errors before virBufferUse
After an OOM error, virBuffer* APIs set buf->use to zero.
Adding a buffer to the parent buffer only if use is non-zero
would quietly drop data on error.
Check the error beforehand to make sure buf->use is zero
because we have not attempted to add anything to it.
Ján Tomko [Tue, 27 Jun 2017 14:24:11 +0000 (16:24 +0200)]
Use a separate buffer for <smartcard> subelements
Convert virDomainSmartcardDefFormat to use a separate buffer
for possible subelements, to avoid the need for duplicated
formatting logic in virDomainDeviceInfoNeedsFormat.
Ján Tomko [Tue, 27 Jun 2017 12:04:52 +0000 (14:04 +0200)]
Remove superfluous usage of virDomainDeviceInfoNeedsFormat
This function returns false if virDomainDeviceInfoFormat
would not format anything.
Using it as the sole condition to decide whether to call
virDomainDeviceInfoFormat or not is pointless, since
the conditions are repeated in virDomainDeviceInfoFormat.
driver: conditionalize use of dlopen functions & use mingw-dlfcn
Not every platform is guaranteed to have dlopen/dlsym, so we should
conditionalize its use. Suprisingly it is actually present for Win32
via the mingw-dlfcn add on, but we should still conditionalize it.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Michal Privoznik [Tue, 25 Jul 2017 15:04:11 +0000 (17:04 +0200)]
virnetworkobj: Make virNetworkObjFindBy{UUID,Name}Locked() static again
These functions were made exportable back in 3aa3e072 when I was
splitting network code into parsing and list management parts.
Since then the split is finished now and these two functions do
not need to be exported anymore.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Michal Privoznik [Thu, 27 Jul 2017 06:43:40 +0000 (08:43 +0200)]
virConnect: Update comment for @privateData
This member allows us to store a pointer to some private data.
However, the comment says it's used in both domain driver and
network driver. Well, it is not. It's just one pointer and domain
driver uses it directly. Network driver has a global driver
variable. Update the comment to not confuse others.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Julio Faracco [Fri, 28 Jul 2017 21:49:35 +0000 (18:49 -0300)]
tools: virsh: Adding unix socket support to 'domdisplay' command.
This commit adds the unix socket URL support to 'domdisplay' command.
Before, even if an user was using unix socket to define a spice graphics,
the command 'domdisplay' showed that the settings were not supported. Now,
the command shows the proper URL: spice+unix://foo/bar.sock.
qemu: Split shmem preparation as it's supposed to be
Since the introduction of shmem, there was a split of preparation code
from the formatting code from qemuBuildCommandLine() into
qemuProcessPrepareDomain(). Let's fix shmem in this regard, so that
we can slowly get to a cleaner codebase.
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
So there are couple of issues here. Firstly, we never unref the
@pendingReply and thus it leaks.
==13279== 144 (72 direct, 72 indirect) bytes in 1 blocks are definitely lost in loss record 1,095 of 1,259
==13279== at 0x4C2E080: calloc (vg_replace_malloc.c:711)
==13279== by 0x781FA97: _dbus_pending_call_new_unlocked (in /usr/lib64/libdbus-1.so.3.14.11)
==13279== by 0x7812A4C: dbus_connection_send_with_reply (in /usr/lib64/libdbus-1.so.3.14.11)
==13279== by 0x56BEDF3: virNetDaemonCallInhibit (virnetdaemon.c:514)
==13279== by 0x56BEF18: virNetDaemonAddShutdownInhibition (virnetdaemon.c:536)
==13279== by 0x12473B: daemonInhibitCallback (libvirtd.c:742)
==13279== by 0x1249BD: daemonRunStateInit (libvirtd.c:823)
==13279== by 0x554FBCF: virThreadHelper (virthread.c:206)
==13279== by 0x8F913D3: start_thread (in /lib64/libpthread-2.23.so)
==13279== by 0x928DE3C: clone (in /lib64/libc-2.23.so)
Secondly, while we send the message, we are suspended ('cos we're
talking to a UNIX socket). However, until we are resumed back
again the reply might have came therefore subsequent
dbus_pending_call_set_notify() has no effect and in fact the
virNetDaemonGotInhibitReply() callback is never called. Thirdly,
the dbus_connection_send_with_reply() has really stupid policy
for return values. To cite the man page:
Returns
FALSE if no memory, TRUE otherwise.
Yes, that's right. If anything goes wrong and it's not case of
OOM then TRUE is returned, i.e. you're trying to pass FDs and
it's not supported, or you're not connected, or anything else.
Therefore, checking for return value of
dbus_connection_send_with_reply() is not enoguh. We also have to
check if @pendingReply is not NULL before proceeding any further.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
We are given a string in @machinename, we never allocate it, just
merely use it for reading. We should not free it otherwise it
leads to double free:
==32191== Thread 17:
==32191== Invalid free() / delete / delete[] / realloc()
==32191== at 0x4C2D1A0: free (vg_replace_malloc.c:530)
==32191== by 0x54BBB84: virFree (viralloc.c:582)
==32191== by 0x2BC04499: qemuProcessStop (qemu_process.c:6313)
==32191== by 0x2BC500FF: processMonitorEOFEvent (qemu_driver.c:4724)
==32191== by 0x2BC502FC: qemuProcessEventHandler (qemu_driver.c:4769)
==32191== by 0x5550640: virThreadPoolWorker (virthreadpool.c:167)
==32191== by 0x554FBCF: virThreadHelper (virthread.c:206)
==32191== by 0x8F913D3: start_thread (in /lib64/libpthread-2.23.so)
==32191== by 0x928DE3C: clone (in /lib64/libc-2.23.so)
==32191== Address 0x31893d70 is 0 bytes inside a block of size 1,100 free'd
==32191== at 0x4C2D1A0: free (vg_replace_malloc.c:530)
==32191== by 0x54BBB84: virFree (viralloc.c:582)
==32191== by 0x54C1936: virCgroupValidateMachineGroup (vircgroup.c:343)
==32191== by 0x54C4B29: virCgroupNewDetectMachine (vircgroup.c:1550)
==32191== by 0x2BBDDA29: qemuConnectCgroup (qemu_cgroup.c:972)
==32191== by 0x2BC05DA7: qemuProcessReconnect (qemu_process.c:6822)
==32191== by 0x554FBCF: virThreadHelper (virthread.c:206)
==32191== by 0x8F913D3: start_thread (in /lib64/libpthread-2.23.so)
==32191== by 0x928DE3C: clone (in /lib64/libc-2.23.so)
==32191== Block was alloc'd at
==32191== at 0x4C2BE80: malloc (vg_replace_malloc.c:298)
==32191== by 0x4C2E35F: realloc (vg_replace_malloc.c:785)
==32191== by 0x54BB492: virReallocN (viralloc.c:245)
==32191== by 0x54BEDF2: virBufferGrow (virbuffer.c:150)
==32191== by 0x54BF3B9: virBufferVasprintf (virbuffer.c:408)
==32191== by 0x54BF324: virBufferAsprintf (virbuffer.c:381)
==32191== by 0x55BB271: virDomainGenerateMachineName (domain_conf.c:27078)
==32191== by 0x2BBD5B8F: qemuDomainGetMachineName (qemu_domain.c:9595)
==32191== by 0x2BBDD9B4: qemuConnectCgroup (qemu_cgroup.c:966)
==32191== by 0x2BC05DA7: qemuProcessReconnect (qemu_process.c:6822)
==32191== by 0x554FBCF: virThreadHelper (virthread.c:206)
==32191== by 0x8F913D3: start_thread (in /lib64/libpthread-2.23.so)
Moreover, make the @machinename 'const char *' to mark it
explicitly that we are not changing the passed string.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Peter Krempa [Wed, 26 Jul 2017 09:06:51 +0000 (11:06 +0200)]
tests: qemumonitorjson: Old and empty test case for node name detection
Prior to qemu 2.5 the node names would not be generated, thus would be
missing from 'query-blockstats' and 'query-named-block-nodes'. Test that
the code correctly detects nothing.
Additionally make sure that a VM without disks does not cause problems.
The test case change is necessary as our test file checker does not play
well with empty files.
Peter Krempa [Fri, 28 Jul 2017 10:37:48 +0000 (12:37 +0200)]
tests: utils: Allow NULL strings to be equal to empty file in virTestCompareToFile
Treat an NULL string equivalent to an empty string in
virTestCompareToFile so that callers don't need to add additional logic
in case when a test produces no output.
Peter Krempa [Fri, 28 Jul 2017 09:49:38 +0000 (11:49 +0200)]
tests: Run virt-aa-helper-test only when the helper was compiled
'virt-aa-helper' is compiled when both WITH_LIBVIRTD and
WITH_SECDRIVER_APPARMOR are defined. The test was run only when
WITH_SECDRIVER_APPARMOR was defined thus causing a build failure when
building without the daemon.
Erik Skultety [Wed, 26 Jul 2017 08:45:11 +0000 (10:45 +0200)]
nodedev: Fix double unlock of the driver on udevEnumerateDevices failure
Commit @4cb719b2dc moved the driver locks around since these have become
unnecessary at spots where the code handles now self-lockable object
list, but missed the possible double unlock if udevEnumerateDevices
fails, because at that point the driver lock had been already dropped.
Signed-off-by: Erik Skultety <eskultet@redhat.com>
Peter Krempa [Wed, 26 Jul 2017 19:57:23 +0000 (21:57 +0200)]
security: apparmor: load the storage driver dynamically
In commit 5e515b542d I've attempted to fix the inability to access
storage from the apparmor helper program by linking with the storage
driver. By linking with the .so the linker complains that it's not
portable. Fix this by loading the module dynamically as we are supposed
to do.
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Pavel Hrdina [Fri, 21 Jul 2017 17:54:33 +0000 (19:54 +0200)]
qemu: properly handle '=' in the VNC socket path
If a domain name contains a '=' and the unix socket path is
auto-generated or socket path provided by user contains '=' QEMU
is unable to properly parse the command line. In order to make it
work we need to use the new command line syntax for VNC if it's
available, otherwise we can use the old syntax.
Peter Krempa [Wed, 26 Jul 2017 09:06:51 +0000 (11:06 +0200)]
tests: qemumonitorjson: Add test case for node name detection with blockjob
qemu 2.9 returns an extra layer in the backing data if a block job is
active. Add a test case to see whether our code properly detects and
ignores such layer.
The test data was prepared by creating a backing chain of qcow2 images
(with qemu-img and with libvirt's snapshot feature).
One of the layers was then merged back by doing a block-commit:
virsh blockcommit VM hda --top /var/lib/libvirt/images/b
and then a block-copy job was started and kept in synchronized phase:
virsh blockcopy VM hda /tmp/tgt.img --transient job
Peter Krempa [Wed, 26 Jul 2017 08:02:21 +0000 (10:02 +0200)]
tests: Extract mock library for making hash table deterministic
virHashNew calls virRandomBits to initialize seed for the hashing
function. If a test uses iteration through the hash table to produce
results they may/will be non-deterministic. Extract the mock library
which was used for mac address mapping to be universal.
Peter Krempa [Wed, 26 Jul 2017 07:36:21 +0000 (09:36 +0200)]
qemu: block: Refactor node name detection code
Remove the complex and unreliable code which inferred the node name
hierarchy only from data returned by 'query-named-block-nodes'. It turns
out that query-blockstats contain the full hierarchy of nodes as
perceived by qemu so the inference code is not necessary.
In query blockstats, the 'parent' object corresponds to the storage
behind a storage volume and 'backing' corresponds to the lower level of
backing chain. Since all have node names this data can be really easily
used to detect node names.
In addition to the code refactoring the one remaining test case needed
to be fixed along.
Peter Krempa [Tue, 25 Jul 2017 15:32:38 +0000 (17:32 +0200)]
qemu: block: Rename qemuBlockFillNodeData and move it to the top
The same operation will become useful in other places so rename the
function to be more generic and move it to the top so that it can be
reused earlier in the file.
Peter Krempa [Tue, 25 Jul 2017 16:40:50 +0000 (18:40 +0200)]
tests: utils: Add virTestLoadFileJSON helper
This new helper loads, parses and returns a JSON file from 'abs_srcdir'
By using variable arguments for the function, it's not necessary to
format the path separately in the test cases.
Peter Krempa [Tue, 25 Jul 2017 13:11:31 +0000 (15:11 +0200)]
tests: utils: Add virTestLoadFilePath helper
This new helper loads and returns a file from 'abs_srcdir'. By using
variable arguments for the function, it's not necessary to format the
path separately in the test cases.
Peter Krempa [Wed, 26 Jul 2017 07:32:10 +0000 (09:32 +0200)]
tests: qemumonitorjson: Drop redundant data from testBlockNodeNameDetectFormat
The node name and backing file name can be inferred from the hierarchy.
This will also help when converting to detect node names using
query-blockstats data.
Peter Krempa [Wed, 26 Jul 2017 07:30:18 +0000 (09:30 +0200)]
tests: qemumonitor: Prepare for more test data in testBlockNodeNameDetect
Rename 'json' and related variables to 'nodeNameJson'. Also rename the
test files along. This is a preparation for modifying how we detect node
names which will also require data from 'query-blockstats'.
This should be considered a configuration error since a vHBA
would not be created. In order to use the HBA as the backing the
following XML should be used:
<adapter type='scsi_host' name='scsi_hostN'/>
So add a check prior to the checkParent call to validate that
the provided wwnn/wwpn resolves to a vHBA and not an HBA.
Since commit 2e6ecba1bcac, the pointer to the qemu driver is saved in
domain object's private data and hence does not have to be passed as
yet another parameter if domain object is already one of them.
This is a first (example) patch of this kind of clean up, others will
hopefully follow.
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Pavel Hrdina [Wed, 19 Jul 2017 15:01:56 +0000 (17:01 +0200)]
qemu: switch QEMU capabilities to use virFileCache
The switch contains considerable amount of changes:
virQEMUCapsRememberCached() is removed because this is now handled
by virFileCacheSave().
virQEMUCapsInitCached() is removed because this is now handled by
virFileCacheLoad().
virQEMUCapsNewForBinary() is split into two functions,
virQEMUCapsNewData() which creates new data if there is nothing
cached and virQEMUCapsLoadFile() which loads the cached data.
This is now handled by virFileCacheNewData().
virQEMUCapsCacheValidate() is removed because this is now handled by
virFileCacheValidate().
virQEMUCapsCacheFree() is removed because it's no longer required.
Add virCapsPtr into virQEMUCapsCachePriv because for each call of
virFileCacheLookup*() we need to use current virCapsPtr.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com> Reviewed-by: Jiri Denemark <jdenemar@redhat.com>
Pavel Hrdina [Fri, 21 Jul 2017 13:09:54 +0000 (15:09 +0200)]
qemu: pass only host arch instead of the whole virCaps
This is a preparation for following patches where we switch to
virFileCache for QEMU capabilities cache
The host arch will always remain the same but virCaps may change. Now
the host arch is stored while creating new qemu capabilities cache.
It removes the need to pass virCaps into virQEMUCapsCache*() functions.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com> Reviewed-by: Jiri Denemark <jdenemar@redhat.com>
Pavel Hrdina [Fri, 21 Jul 2017 12:24:51 +0000 (14:24 +0200)]
tests: rewrite host CPU mocking
Move all the host CPU data into a separate file and rewrite qemucpumock
to not use passed @caps. This is preparation for following patch which
will replace virCaps argument with virArch.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com> Reviewed-by: Jiri Denemark <jdenemar@redhat.com>
Pavel Hrdina [Fri, 7 Apr 2017 15:34:53 +0000 (17:34 +0200)]
util: introduce virFileCache
The new virFileCache will nicely handle the caching logic for any data
that we would like to cache. For each type of data we will just need
to implement few handlers that will take care of creating, validating,
loading and saving the cached data.
The cached data must be an instance of virObject.
Currently we cache QEMU capabilities which will start using
virFileCache.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com> Reviewed-by: Jiri Denemark <jdenemar@redhat.com>
Scott Garfinkle [Tue, 25 Jul 2017 14:33:50 +0000 (09:33 -0500)]
Generate unique socket file
It's possible to have more than one unnamed virtio-serial unix channel.
We need to generate a unique name for each channel. Currently, we use
".../unknown.sock" for all of them. Better practice would be to specify
an explicit target path name; however, in the absence of that, we need
uniqueness in the names we generate internally.
Before the changes we'd get /var/lib/libvirt/qemu/channel/target/unknown.sock
for each instance of
<channel type='unix'>
<source mode='bind'/>
<target type='virtio'/>
</channel>
Now, we get vioser-00-00-01.sock, vioser-00-00-02.sock, etc.
Move machineName generation from virsystemd into domain_conf
It is more related to a domain as we might use it even when there is
no systemd and it does not use any dbus/systemd functions. In order
not to use code from conf/ in util/ pass machineName in cgroups code
as a parameter. That also fixes a leak of machineName in the lxc
driver and cleans up and de-duplicates some code.
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
John Ferlan [Thu, 1 Jun 2017 16:43:06 +0000 (12:43 -0400)]
secret: Handle object list removal and deletion properly
Rather than rely on virSecretObjEndAPI to make the final virObjectUnref
after the call to virSecretObjListRemove, be more explicit by calling
virObjectUnref and setting @obj to NULL for secretUndefine and in
the error path of secretDefineXML. Calling EndAPI will end up calling
Unlock on an already unlocked object which has indeteriminate results
(usually an ignored error).
The virSecretObjEndAPI will both Unref and Unlock the object; however,
the virSecretObjListRemove would have already Unlock'd the object so
calling Unlock again is incorrect. Once the virSecretObjListRemove
is called all that's left is to Unref our interest since that's the
corrollary to the virSecretObjListAdd which returned our ref interest
plus references for each hash table in which the object resides. In math
terms, after an Add there's 2 refs on the object (1 for the object and
1 for the list). After calling Remove there's just 1 ref on the object.
For the Add callers, calling EndAPI removes the ref for the object and
unlocks it, but since it's in a list the other 1 remains.
John Ferlan [Tue, 25 Jul 2017 13:02:09 +0000 (09:02 -0400)]
secret: Fix memory leak in virSecretLoad
If the virSecretLoadValue fails, the code jumped to cleanup without
setting @ret = obj, thus calling virSecretObjListRemove which only
accounts for the object reference related to adding the object to
the list during virSecretObjListAdd, but does not account for the
reference to the object itself as the return of @ret would be NULL
so the caller wouldn't call virSecretObjEndAPI on the object recently
added thus reducing the refcnt to zero.
This patch will perform the ObjListRemove in the failure path of
virSecretLoadValue and Unref @obj in order to perform clean up
and return @obj as NULL. The @def will be freed as part of the
virObjectUnref.
John Ferlan [Thu, 1 Jun 2017 12:17:52 +0000 (08:17 -0400)]
secret: Properly handle @def after virSecretObjAdd in driver
Since the virSecretObjListAdd technically consumes @def on success,
the secretDefineXML should set @def = NULL immediately and process
the remaining calls using a new @objDef variable. We can use use
VIR_STEAL_PTR since we know the Add function just stores @def in
obj->def.
Because we steal @def into @objDef, if we jump to restore_backup:
and @backup is set, then we need to ensure the @def would be
free'd properly, so we'll steal it back from @objDef. For the other
condition this fixes a double free of @def if the code had jumped to
@backup == NULL thus calling virSecretObjListRemove without setting
@def = NULL. In this case, the subsequent call to DefFree would
succeed and free @def; however, the call to EndAPI would also
call DefFree because the Unref done would be the last one for
the @obj meaning the obj->def would be used to call DefFree,
but it's already been free'd because @def wasn't managed right
within this error path.
As it turns out, this is not portable and very Linux & glibc
specific. Worse, this may lead to not starving writers on Linux
but everywhere else. Revert this and if the starvation occurs
resolve it.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com> Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Andrea Bolognani [Wed, 19 Jul 2017 08:37:04 +0000 (10:37 +0200)]
conf: Fix backwards migration of pSeries guests
Recent commits made it so that pci-root controllers for
pSeries guests are automatically assigned the
spapr-pci-host-bridge model name; however, that prevents
guests to migrate to older versions of libvirt which don't
know about that model name at all, which at the moment is
all of them :)
To avoid the issue, just strip the model name from PHBs
when formatting the migratable XML; guests that use more
than one PHB are not going to be migratable anyway.
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
If the parent provided for the storage pool adapter is not vHBA
capable, then issue a configuration error even though the provided
wwnn/wwpn were found.
It is a configuration error to provide a mismatched parent to
the wwnn/wwpn. The @parent is optional and is used as a means to
perform duplicate pool source checks.
Commit id '106930aaa' altered the order of checking for an existing
vHBA (e.g something created via nodedev-create functionality outside
of the storage pool logic) which inadvertantly broke the code to
decide whether to alter/force the fchost->managed field to be 'yes'
because the storage pool will be managing the created vHBA in order
to ensure when the storage pool is destroyed that the vHBA is also
destroyed.
This patch moves the check (and checkParent helper) for an existing
vHBA back into the createVport in storage_backend_scsi. It also
adjusts the checkParent logic to more closely follow the intentions
prior to commit id '79ab0935'. The changes made by commit id '08c0ea16f'
are only necessary to run the virStoragePoolFCRefreshThread when
a vHBA was really created because there's a timing lag such that
the refreshPool call made after a startPool from storagePoolCreate*
wouldn't necessarily find LUNs, but the thread would. For an already
existing vHBA, using the thread is unnecessary since the vHBA already
exists and the lag to configure the LUNs wouldn't exist.
John Ferlan [Thu, 29 Jun 2017 20:51:54 +0000 (16:51 -0400)]
nodedev: Remove driver locks around object list mgmt code
Since virnodedeviceobj now has a self-lockable hash table, there's no
need to lock the table from the driver for processing. Thus remove the
locks from the driver for NodeDeviceObjList mgmt.
John Ferlan [Thu, 29 Jun 2017 19:50:06 +0000 (15:50 -0400)]
nodedev: Convert virNodeDeviceObjListPtr to use hash tables
Rather than use a forward linked list of elements, it'll be much more
efficient to use a hash table to reference the elements by unique name
and to perform hash searches.
This patch does all the heavy lifting of converting the list object to
use a self locking list that contains the hash table. Each of the FindBy
functions that do not involve finding the object by it's key (name) is
converted to use virHashSearch in order to find the specific object.
When searching for the key (name), it's possible to use virHashLookup.
For any of the list perusal functions that are required to evaluate
each object, the virHashForEach function is used.
John Ferlan [Thu, 20 Jul 2017 13:07:52 +0000 (09:07 -0400)]
nodedev: Alter node device deletion logic
Alter the node device deletion logic to make use of the parent field
from the obj->def rather than call virNodeDeviceObjListGetParentHost.
As it turns out the saved @def won't have parent_wwnn/wwpn or
parent_fabric_wwn, so the only logical path would be to call
virNodeDeviceObjListGetParentHostByParent which we can accomplish
directly via virNodeDeviceObjListFindByName.
Michal Privoznik [Wed, 19 Jul 2017 10:11:05 +0000 (12:11 +0200)]
virdomainobjlist: Use virObjectRWLockable
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: Michal Privoznik <mprivozn@redhat.com> Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Michal Privoznik [Wed, 19 Jul 2017 07:31:50 +0000 (09:31 +0200)]
virobject: Introduce virObjectRWLockable
Up until now we only had virObjectLockable which uses mutexes for
mutually excluding each other in critical section. Well, this is
not enough. Future work will require RW locks so we might as well
have virObjectRWLockable which is introduced here.
Moreover, polymorphism is introduced to our code for the first
time. Yay! More specifically, virObjectLock will grab a write
lock, virObjectLockRead will grab a read lock then (what a
surprise right?). This has great advantage that an object can be
made derived from virObjectRWLockable in a single line and still
continue functioning properly (mutexes can be viewed as grabbing
write locks only). Then just those critical sections that can
grab a read lock need fixing. Therefore the resulting change is
going to be way smaller.
In order to avoid writer starvation, the object initializes RW
lock that prefers writers.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com> Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Michal Privoznik [Wed, 19 Jul 2017 10:54:23 +0000 (12:54 +0200)]
virthread: Introduce virRWLockInitPreferWriter
We already have virRWLockInit. But this uses pthread defaults
which prefer reader to initialize the RW lock. This may lead to
writer starvation. Therefore we need to have the counterpart that
prefers writers. Now, according to the
pthread_rwlockattr_setkind_np() man page setting
PTHREAD_RWLOCK_PREFER_WRITER_NP attribute is no-op. Therefore we
need to use PTHREAD_RWLOCK_PREFER_WRITER_NONRECURSIVE_NP
attribute. So much for good enum value names.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com> Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
projects / libvirt.git / log