|
 |
2d1356 |
From a3176697f2d1288d3e30ca6aac0d2c5891a6b135 Mon Sep 17 00:00:00 2001
|
|
|
2d1356 |
Message-Id: <a3176697f2d1288d3e30ca6aac0d2c5891a6b135@dist-git>
|
|
|
2d1356 |
From: Peter Krempa <pkrempa@redhat.com>
|
|
|
2d1356 |
Date: Thu, 26 May 2016 12:54:54 +0200
|
|
|
2d1356 |
Subject: [PATCH] qemu: bulk stats: Don't access possibly blocked storage
|
|
|
2d1356 |
|
|
|
2d1356 |
https://bugzilla.redhat.com/show_bug.cgi?id=1339963
|
|
|
2d1356 |
|
|
|
2d1356 |
If the stats for a block device can't be acquired from qemu we've
|
|
|
2d1356 |
fallen back to loading them from the file on the disk in libvirt.
|
|
|
2d1356 |
|
|
|
2d1356 |
If qemu is not cooperating due to being stuck on an inaccessible NFS
|
|
|
2d1356 |
share we would then attempt to read the files and get stuck too with
|
|
|
2d1356 |
the VM object locked. All other APIs would eventually get stuck waiting
|
|
|
2d1356 |
on the VM lock.
|
|
|
2d1356 |
|
|
|
2d1356 |
Avoid this problem by skipping the block stats if the VM is online but
|
|
|
2d1356 |
the monitor did not provide any stats.
|
|
|
2d1356 |
|
|
|
2d1356 |
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1337073
|
|
|
2d1356 |
(cherry picked from commit 71d2c172edb997bae1e883b2e1bafa97d9f953a1)
|
|
|
2d1356 |
---
|
|
|
2d1356 |
src/qemu/qemu_driver.c | 13 +++++++++++--
|
|
|
2d1356 |
1 file changed, 11 insertions(+), 2 deletions(-)
|
|
|
2d1356 |
|
|
|
2d1356 |
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
|
|
|
2d1356 |
index 1075237..5e28b21 100644
|
|
|
2d1356 |
--- a/src/qemu/qemu_driver.c
|
|
|
2d1356 |
+++ b/src/qemu/qemu_driver.c
|
|
|
2d1356 |
@@ -19392,13 +19392,22 @@ qemuDomainGetStatsOneBlock(virQEMUDriverPtr driver,
|
|
|
2d1356 |
QEMU_ADD_BLOCK_PARAM_UI(record, maxparams, block_idx, "backingIndex",
|
|
|
2d1356 |
backing_idx);
|
|
|
2d1356 |
|
|
|
2d1356 |
- /* use fallback path if data is not available */
|
|
|
2d1356 |
- if (!stats || !alias || !(entry = virHashLookup(stats, alias))) {
|
|
|
2d1356 |
+ /* the VM is offline so we have to go and load the stast from the disk by
|
|
|
2d1356 |
+ * ourselves */
|
|
|
2d1356 |
+ if (!virDomainObjIsActive(dom)) {
|
|
|
2d1356 |
ret = qemuDomainGetStatsOneBlockFallback(driver, cfg, dom, record,
|
|
|
2d1356 |
maxparams, src, block_idx);
|
|
|
2d1356 |
goto cleanup;
|
|
|
2d1356 |
}
|
|
|
2d1356 |
|
|
|
2d1356 |
+ /* In case where qemu didn't provide the stats we stop here rather than
|
|
|
2d1356 |
+ * trying to refresh the stats from the disk. Inability to provide stats is
|
|
|
2d1356 |
+ * usually caused by blocked storage so this would make libvirtd hang */
|
|
|
2d1356 |
+ if (!stats || !alias || !(entry = virHashLookup(stats, alias))) {
|
|
|
2d1356 |
+ ret = 0;
|
|
|
2d1356 |
+ goto cleanup;
|
|
|
2d1356 |
+ }
|
|
|
2d1356 |
+
|
|
|
2d1356 |
QEMU_ADD_BLOCK_PARAM_LL(record, maxparams, block_idx,
|
|
|
2d1356 |
"rd.reqs", entry->rd_req);
|
|
|
2d1356 |
QEMU_ADD_BLOCK_PARAM_LL(record, maxparams, block_idx,
|
|
|
2d1356 |
--
|
|
|
2d1356 |
2.8.3
|
|
|
2d1356 |
|