qemu: don't log error for missing optional storage sources on stats

Every time we call all domain stats for inactive domain with
unavailable storage source we get error message in logs [1]. It's a bit noisy.
While it's arguable whether we need such message or not for mandatory
disks we would like not to see messages for optional disks. Let's
filter at least for cases of local files. Fixing other cases would
require passing flag down the stack to .backendInit of storage
which is ugly.

Stats for active domain are fine because we either drop disks
with unavailable sources or clean source which is handled
by virStorageSourceIsEmpty in qemuDomainGetStatsOneBlockFallback.

We have these logs for successful stats since 25aa7035d (version 1.2.15)
which in turn fixes 596a13713 (version 1.2.12 )which added substantial
stats for offline disks.

[1] error message example:
qemuOpenFileAs:3324 : Failed to open file '/path/to/optional/disk': No such file or directory

Signed-off-by: Nikolay Shirokovskiy <nshirokovskiy@virtuozzo.com>
This commit is contained in:
Nikolay Shirokovskiy 2018-11-09 12:21:50 +03:00
parent dfbd7315c0
commit 318d807a0b
3 changed files with 26 additions and 0 deletions

View File

@ -13704,3 +13704,12 @@ qemuDomainIsUsingNoShutdown(qemuDomainObjPrivatePtr priv)
{
return priv->monJSON && priv->allowReboot == VIR_TRISTATE_BOOL_YES;
}
bool
qemuDomainDiskIsMissingLocalOptional(virDomainDiskDefPtr disk)
{
return disk->startupPolicy == VIR_DOMAIN_STARTUP_POLICY_OPTIONAL &&
virStorageSourceIsLocalStorage(disk->src) && disk->src->path &&
!virFileExists(disk->src->path);
}

View File

@ -1095,4 +1095,7 @@ qemuDomainRunningReasonToResumeEvent(virDomainRunningReason reason);
bool
qemuDomainIsUsingNoShutdown(qemuDomainObjPrivatePtr priv);
bool
qemuDomainDiskIsMissingLocalOptional(virDomainDiskDefPtr disk);
#endif /* LIBVIRT_QEMU_DOMAIN_H */

View File

@ -20720,6 +20720,20 @@ qemuDomainGetStatsBlockExportDisk(virDomainDiskDefPtr disk,
const char *backendstoragealias;
int ret = -1;
/*
* This helps to keep logs clean from error messages on getting stats
* for optional disk with nonexistent source file. We won't get any
* stats for such a disk anyway in below code.
*/
if (!virDomainObjIsActive(dom) &&
qemuDomainDiskIsMissingLocalOptional(disk)) {
VIR_INFO("optional disk '%s' source file is missing, "
"skip getting stats", disk->dst);
return qemuDomainGetStatsBlockExportHeader(disk, disk->src, *recordnr,
records, nrecords);
}
for (n = disk->src; virStorageSourceIsBacking(n); n = n->backingStore) {
if (blockdev) {
frontendalias = QEMU_DOMAIN_DISK_PRIVATE(disk)->qomName;