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
Similarly to deprecating close(), I am now deprecating fclose() and
introduce VIR_FORCE_FCLOSE() and VIR_FCLOSE(). Also, fdopen() is replaced with
VIR_FDOPEN().
Most of the files are opened in read-only mode, so usage of
VIR_FORCE_CLOSE() seemed appropriate. Others that are opened in write
mode already had the fclose()< 0 check and I converted those to
VIR_FCLOSE()< 0.
I did not find occurrences of possible double-closed files on the way.
Using automated replacement with sed and editing I have now replaced all
occurrences of close() with VIR_(FORCE_)CLOSE() except for one, of
course. Some replacements were straight forward, others I needed to pay
attention. I hope I payed attention in all the right places... Please
have a look. This should have at least solved one more double-close
error.
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
