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
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.
Nearly all of the methods in src/util/util.h have error codes that
must be checked by the caller to correct detect & report failure.
Add ATTRIBUTE_RETURN_CHECK to ensure compile time validation of
this
* daemon/libvirtd.c: Add explicit check on return value of virAsprintf
* src/conf/domain_conf.c: Add missing check on virParseMacAddr return
value status & report error
* src/network/bridge_driver.c: Add missing OOM check on virAsprintf
and report error
* src/qemu/qemu_conf.c: Add missing check on virParseMacAddr return
value status & report error
* src/security/security_selinux.c: Remove call to virRandomInitialize
that's done in libvirt.c already
* src/storage/storage_backend_logical.c: Add check & log on virRun
return status
* src/util/util.c: Add missing checks on virAsprintf/Run status
* src/util/util.h: Annotate all methods with ATTRIBUTE_RETURN_CHECK
if they return an error status code
* src/vbox/vbox_tmpl.c: Add missing check on virParseMacAddr
* src/xen/xm_internal.c: Add missing checks on virAsprintf
* tests/qemuargv2xmltest.c: Remove bogus call to virRandomInitialize()
