Different protocols have different means to uniquely identify a storage
file. This patch implements a storage driver API to retrieve a unique
string describing a volume. The current implementation works for local
storage only and returns the canonical path of the volume.
To add caching support the local filesystem driver now has a private
structure holding the cached string, which is created only when it's
initially accessed.
This patch provides the implementation for local files only for start.
Add storage driver based functions to access headers of storage files
for metadata extraction. Along with this patch a local filesystem and
gluster via libgfapi implementation is provided. The gluster
implementation is based on code of the saferead_lim function.
To allow using the storage driver APIs to access files on various
storage sources in a universal fashion possibly on storage such as nfs
with root squash we'll need to store the desired uid/gid in the
metadata.
Add new initialisation API that will store the desired uid/gid and a
wrapper for the current use. Additionally add docs for the two APIs.
Commit id 'ac9a0963' refactored out the 'withCapacity' for the
virStorageBackendUpdateVolInfo() API. See:
http://www.redhat.com/archives/libvir-list/2014-April/msg00043.html
This resulted in a difference in how 'virsh vol-info --pool <poolName>
<volume>' or 'virsh vol-list vol-list --pool <poolName> --details' outputs
the capacity information for a directory pool with a qcow2 sparse file.
For example, using the following XML
mkdir /home/TestPool
cat testpool.xml
<pool type='dir'>
<name>TestPool</name>
<uuid>6bf80895-10b6-75a6-6059-89fdea2aefb7</uuid>
<source>
</source>
<target>
<path>/home/TestPool</path>
<permissions>
<mode>0755</mode>
<owner>0</owner>
<group>0</group>
</permissions>
</target>
</pool>
virsh pool-create testpool.xml
virsh vol-create-as --pool TestPool temp_vol_1 \
--capacity 1048576 --allocation 1048576 --format qcow2
virsh vol-info --pool TestPool temp_vol_1
Results in listing a Capacity value. Prior to the commit, the value would
be '1.0 MiB' (1048576 bytes). However, after the commit the output would be
(for example) '192.50 KiB', which for my system was the size of the volume
in my file system (eg 'ls -l TestPool/temp_vol_1' results in '197120' bytes
or 192.50 KiB). While perhaps technically correct, it's not necessarily
what the user expected (certainly virt-test didn't expect it).
This patch restores the code to not update the target capacity for this path
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.
Currently VolOpen notifies the user of a potentially non-fatal failure by
returning -2 and logging a VIR_WARN or VIR_INFO. Unfortunately most
callers treat -2 as fatal but don't actually report any message with
the error APIs.
Rename the VOL_OPEN_ERROR flag to VOL_OPEN_NOERROR. If NOERROR is specified,
we preserve the current behavior of returning -2 (there's only one caller
that wants this).
However in the default case, only return -1, and actually use the error
APIs. Fix up a couple callers as a result.
Now that each virStorageSource can track allocation information,
and given that we already have the information without extra
syscalls, it's easier to just always populate the information
directly into the struct than it is to sometimes pass the address
of the struct members down the call chain.
* src/storage/storage_backend.h (virStorageBackendUpdateVolInfo)
(virStorageBackendUpdateVolTargetInfo)
(virStorageBackendUpdateVolTargetInfoFD): Update signature.
* src/storage/storage_backend.c (virStorageBackendUpdateVolInfo)
(virStorageBackendUpdateVolTargetInfo)
(virStorageBackendUpdateVolTargetInfoFD): Always populate struct
members instead.
* src/storage/storage_backend_disk.c
(virStorageBackendDiskMakeDataVol): Update client.
* src/storage/storage_backend_fs.c (virStorageBackendProbeTarget)
(virStorageBackendFileSystemRefresh)
(virStorageBackendFileSystemVolRefresh): Likewise.
* src/storage/storage_backend_gluster.c
(virStorageBackendGlusterRefreshVol): Likewise.
* src/storage/storage_backend_logical.c
(virStorageBackendLogicalMakeVol): Likewise.
* src/storage/storage_backend_mpath.c
(virStorageBackendMpathNewVol): Likewise.
* src/storage/storage_backend_scsi.c
(virStorageBackendSCSINewLun): Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
A fairly smooth transition. And now that domain disks and
storage volumes share a common struct, it opens the doors for
a future patch to expose more details in the XML for both
objects.
* src/conf/storage_conf.h (_virStorageVolTarget): Delete.
(_virStorageVolDef): Use common type.
* src/conf/storage_conf.c (virStorageVolDefFree)
(virStorageVolTargetDefFormat): Update clients.
* src/storage/storage_backend.h: Likewise.
* src/storage/storage_backend.c
(virStorageBackendDetectBlockVolFormatFD)
(virStorageBackendUpdateVolTargetInfo)
(virStorageBackendUpdateVolTargetInfoFD): Likewise.
* src/storage/storage_backend_fs.c (virStorageBackendProbeTarget):
Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
https://bugzilla.redhat.com/show_bug.cgi?id=1072714
Use the "gluster" command line tool to retrieve information about remote
volumes on a gluster server to allow storage pool source lookup.
Unfortunately gluster doesn't provide a management library so that we
could use that directly, instead the RPC calls are hardcoded in the
command line tool.
Without this, using /dev/mapper as a directory pool
fails in virStorageBackendUpdateVolTargetInfoFD:
cannot seek to end of file '/dev/mapper/control': Illegal seek
Skip over character devices by default.
https://bugzilla.redhat.com/show_bug.cgi?id=710866
In commit e32268184b I accidentally added
twice a typedef for virStorageFileBackend when I moved it between files
across patch iterations. The double declaration breaks build on older
compilers in RHEL5 and FreeBSD.
Remove the spurious definition.
Add APIs that will allow to use the storage driver to assist in
operations on files even for remote filesystems without native
representation as files in the host.
We support gluster volumes in domain XML, so we also ought to
support them as a storage pool. Besides, a future patch will
want to take advantage of libgfapi to handle the case of a
gluster device holding qcow2 rather than raw storage, and for
that to work, we need a storage backend that can read gluster
storage volume contents. This sets up the framework.
Note that the new pool is named 'gluster' to match a
<disk type='network'><source protocol='gluster'> image source
already supported in a <domain>; it does NOT match the
<pool type='netfs'><source><target type='glusterfs'>,
since that uses a FUSE mount to a local file name rather than
a network name.
This and subsequent patches have been tested against glusterfs
3.4.1 (available on Fedora 19); there are likely bugs in older
versions that may prevent decent use of gfapi, so this patch
enforces the minimum version tested. A future patch may lower
the minimum. On the other hand, I hit at least two bugs in
3.4.1 that will be fixed in 3.5/3.4.2, where it might be worth
raising the minimum: glfs_readdir is nicer to use than
glfs_readdir_r [1], and glfs_fini should only return failure on
an actual failure [2].
[1] http://lists.gnu.org/archive/html/gluster-devel/2013-10/msg00085.html
[2] http://lists.gnu.org/archive/html/gluster-devel/2013-10/msg00086.html
* configure.ac (WITH_STORAGE_GLUSTER): New conditional.
* m4/virt-gluster.m4: new file.
* libvirt.spec.in (BuildRequires): Support gluster in spec file.
* src/conf/storage_conf.h (VIR_STORAGE_POOL_GLUSTER): New pool
type.
* src/conf/storage_conf.c (poolTypeInfo): Treat similar to
sheepdog and rbd.
(virStoragePoolDefFormat): Don't output target for gluster.
* src/storage/storage_backend_gluster.h: New file.
* src/storage/storage_backend_gluster.c: Likewise.
* po/POTFILES.in: Add new file.
* src/storage/storage_backend.c (backends): Register new type.
* src/Makefile.am (STORAGE_DRIVER_GLUSTER_SOURCES): Build new files.
* src/storage/storage_backend.h (_virStorageBackend): Documet
assumption.
Signed-off-by: Eric Blake <eblake@redhat.com>
We are calling fstat() at least twice per storage volume in
a directory storage pool; this is rather wasteful. Refactoring
this is also a step towards making code reusable for gluster,
where gluster can provide struct stat but cannot use fstat().
* src/storage/storage_backend.h
(virStorageBackendVolOpenCheckMode)
(virStorageBackendUpdateVolTargetInfoFD): Update signature.
* src/storage/storage_backend.c
(virStorageBackendVolOpenCheckMode): Pass stat results back.
(virStorageBackendUpdateVolTargetInfoFD): Use existing stats.
(virStorageBackendVolOpen, virStorageBackendUpdateVolTargetInfo):
Update callers.
* src/storage/storage_backend_fs.c (virStorageBackendProbeTarget):
Likewise.
* src/storage/storage_backend_scsi.c
(virStorageBackendSCSIUpdateVolTargetInfo): Likewise.
* src/storage/storage_backend_mpath.c
(virStorageBackendMpathUpdateVolTargetInfo): Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
Add VIR_STORAGE_VOL_CREATE_PREALLOC_METADATA flag to virStorageVolCreateXML
and virStorageVolCreateXMLFrom. This flag requests metadata
preallocation when creating/cloning qcow2 images, resulting in creating
a sparse file with qcow2 metadata. It has only slightly larger disk usage
compared to new image with no allocation, but offers higher performance.
Rename the 'wait' parameter to 'loop'.
This silences the warning:
storage/storage_backend.c:1348:34: error: declaration of 'wait' shadows
a global declaration [-Werror=shadow]
and fixes the build with -Werror.
--
Note: loop is pool backwards.
virStorageVolLookupByPath is an API call that virt-manager uses
quite a bit when dealing with storage. This call use BackendStablePath
which has several usleep() heuristics that can be tripped up
and hang virt-manager for a while.
Current example: an empty mpath pool pointing to /dev/mapper makes
_any_ calls to virStorageVolLookupByPath take 5 seconds.
The sleep heuristics are actually only needed in certain cases
when we are waiting for new storage to appear, so let's skip the
timeout steps when calling from LookupByPath.
https://www.gnu.org/licenses/gpl-howto.html recommends that
the 'If not, see <url>.' phrase be a separate sentence.
* tests/securityselinuxhelper.c: Remove doubled line.
* tests/securityselinuxtest.c: Likewise.
* globally: s/; If/. If/
Otherwise, in locations like virobject.c where PROBE is used,
for certain configure options, the compiler warns:
util/virobject.c:110:1: error: 'intptr_t' undeclared (first use in this function)
As long as we are making this header always available, we can
clean up several other files.
* src/internal.h (includes): Pull in <stdint.h>.
* src/conf/nwfilter_conf.h: Rely on internal.h.
* src/storage/storage_backend.c: Likewise.
* src/storage/storage_backend.h: Likewise.
* src/util/cgroup.c: Likewise.
* src/util/sexpr.h: Likewise.
* src/util/virhashcode.h: Likewise.
* src/util/virnetdevvportprofile.h: Likewise.
* src/util/virnetlink.h: Likewise.
* src/util/virrandom.h: Likewise.
* src/vbox/vbox_driver.c: Likewise.
* src/xenapi/xenapi_driver.c: Likewise.
* src/xenapi/xenapi_utils.c: Likewise.
* src/xenapi/xenapi_utils.h: Likewise.
* src/xenxs/xenxs_private.h: Likewise.
* tests/storagebackendsheepdogtest.c: Likewise.
Per the FSF address could be changed from time to time, and GNU
recommends the following now: (http://www.gnu.org/licenses/gpl-howto.html)
You should have received a copy of the GNU General Public License
along with Foobar. If not, see <http://www.gnu.org/licenses/>.
This patch removes the explicit FSF address, and uses above instead
(of course, with inserting 'Lesser' before 'General').
Except a bunch of files for security driver, all others are changed
automatically, the copyright for securify files are not complete,
that's why to do it manually:
src/security/security_selinux.h
src/security/security_driver.h
src/security/security_selinux.c
src/security/security_apparmor.h
src/security/security_apparmor.c
src/security/security_driver.c
Update the storage driver to use virReportError instead of
the virStorageReportError custom macro
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
To make it easier to dynamically change the command line ARGV,
switch all storage code over to use virCommandPtr APIs for
running programs
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
If the regexes supported (?:pvs)?, then we could handle this by
optionally matching but not returning the initial command name. But it
doesn't. So add a new char* argument to
virStorageBackendRunProgRegex(). If that argument is NULL then we act
as usual. Otherwise, if the string at that argument is found at the
start of a returned line, we drop that before running the regex.
With this patch, virt-manager shows me lvs with command_names 1 or 0.
The definitions of PVS_BASE etc may want to be moved into the configure
scripts (though given how PVS is found, IIUC that could only happen if
pvs was a link to pvs_real), but in any case no sense dealing with that
until we're sure this is an ok way to handle it.
Signed-off-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Since directories can be used for <filesystem> passthrough, they are
basically storage volumes.
v2:
Skip ., .., lost+found dirs
v3:
Use gnulib last_component
v4:
Use gnulib "dirname.h", not system <dirname.h>
Don't skip lost+found
When libvirt starts up all storage pools default to the inactive
state, even if the underlying storage is already active on the
host. This introduces a new API into the internal storage backend
drivers that checks whether a storage pool is already active. If
the pool is active at libvirtd startup, the volume list will be
immediately populated.
* src/storage/storage_backend.h: New internal API for checking
storage pool state
* src/storage/storage_driver.c: Check whether a pool is active
upon driver startup
* src/storage/storage_backend_fs.c, src/storage/storage_backend_iscsi.c,
src/storage/storage_backend_logical.c, src/storage/storage_backend_mpath.c,
src/storage/storage_backend_scsi.c: Add checks for pool state
If a directory pool contains pipes or sockets, a pool start can fail or hang:
https://bugzilla.redhat.com/show_bug.cgi?id=589577
We already try to avoid these special files, but only attempt after
opening the path, which is where the problems lie. Unify volume opening
into helper functions, which use the proper open() flags to avoid error,
followed by fstat to validate storage mode.
Previously, virStorageBackendUpdateVolTargetInfoFD attempted to enforce the
storage mode check, but allowed callers to detect this case and silently
continue. In practice, only the FS backend was using this feature, the rest
were treating unknown mode as an error condition. Unfortunately the InfoFD
function wasn't raising an error message here, so error reporting was
busted.
This patch adds 2 functions: virStorageBackendVolOpen, and
virStorageBackendVolOpenModeSkip. The latter retains the original opt out
semantics, the former now throws an explicit error.
This patch maintains the previous volume mode checks: allowing specific
modes for specific pool types requires a bit of surgery, since VolOpen
is called through several different helper functions.
v2: Use ATTRIBUTE_NONNULL. Drop stat check, just open with
O_NONBLOCK|O_NOCTTY.
v3: Move mode check logic back to VolOpen. Use 2 VolOpen functions with
different error semantics.
v4: Make second VolOpen function more extensible. Didn't opt to change
FS backend defaults, this can just be to fix the original bug.
v5: Prefix default flags with VIR_, use ATTRIBUTE_RETURN_CHECK
Volume detection in the scsi backend was duplicating code already
present in storage_backend.c. Let's drop the duplicate code.
Also, change the shared function name to be less generic, and remove
some error squashing in the other call site.
The virConnectPtr is no longer required for error reporting since
that is recorded in a thread local. Remove use of virConnectPtr
from all APIs in storage_conf.{h,c} and storage_encryption_conf.{h,c}
and update all callers to match
In order to avoid problems trying to chown files that were created by
root on a root-squashing nfs server, fork a new process that setuid's
to the desired uid before creating the file. (It's only done this way
if the pool containing the new volume is of type 'netfs', otherwise
the old method of creating the file followed by chown() is used.)
This changes the semantics of the "create_func" slightly - previously
it was assumed that this function just created the file, then the
caller would chown it to the desired uid. Now, create_func does both
operations.
There are multiple functions that can take on the role of create_func:
createFileDir - previously called mkdir(), now calls virDirCreate().
virStorageBackendCreateRaw - previously called open(),
now calls virFileCreate().
virStorageBackendCreateQemuImg - use virRunWithHook() to setuid/gid.
virStorageBackendCreateQcowCreate - same.
virStorageBackendCreateBlockFrom - preserve old behavior (but attempt
chown when necessary even if not root)
* src/storage/storage_backend.[ch] src/storage/storage_backend_disk.c
src/storage/storage_backend_fs.c src/storage/storage_backend_logical.c
src/storage/storage_driver.c: change the create_func implementations,
also propagate the pool information to be able to detect NETFS ones.
