From 2086e6329ab1592ed045f18711dce4be79fe6724 Mon Sep 17 00:00:00 2001
Message-Id: <2086e6329ab1592ed045f18711dce4be79fe6724.1429290875.git.jen@redhat.com>
From: Kevin Wolf <kwolf@redhat.com>
Date: Wed, 15 Apr 2015 08:56:51 -0500
Subject: [CHANGE] block: Fix query-block after disabling throttling
To: rhvirt-patches@redhat.com,
jen@redhat.com
RH-Author: Kevin Wolf <kwolf@redhat.com>
Message-id: <1429088211-4125-1-git-send-email-kwolf@redhat.com>
Patchwork-id: 64816
O-Subject: [RHEL-6.7 qemu-kvm PATCH] block: Fix query-block after disabling throttling
Bugzilla: 1211545
RH-Acked-by: Max Reitz <mreitz@redhat.com>
RH-Acked-by: Fam Zheng <famz@redhat.com>
RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Upstream status: Fix for downstream-only code
If a VM had I/O throttling enabled, and then it was disabled at runtime,
query-block would still return the old throttling limits. This patch
fixes it to return 0 for all limits.
This problem originates in downstream commit 669ccf4e, which differs
from the corresponding upstream commit 727f005e in that it doesn't check
bs->io_limits_enabled before accessing the limits. This was not a
problem directly after the backport because disabling throttling
involved clearing all limits to 0.
The new throttling code as introduced in downstream commit 25ef1eb9
(upstream cc0681c4), however, updates the limits only if throtting is
enabled after the change. It appears a little weird to leave old values
around and just resetting all limits to 0 might be the nicer fix, but
this is what upstream still does today, so I chose to do the same here.
For the fix this means that the code for setting the limits is
unchanged, but query-block checks bs->io_limits_enabled before accessing
the limits.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
Buzgilla: https://bugzilla.redhat.com/show_bug.cgi?id=1211545
Brew: http://brewweb.devel.redhat.com/brew/taskinfo?taskID=8982488
---
block.c | 20 +++++++++++---------
1 file changed, 11 insertions(+), 9 deletions(-)
Signed-off-by: Jeff E. Nelson <jen@redhat.com>
---
block.c | 18 ++++++++++--------
1 file changed, 10 insertions(+), 8 deletions(-)
diff --git a/block.c b/block.c
index 524569e..6c14a9d 100644
--- a/block.c
+++ b/block.c
@@ -3075,15 +3075,17 @@ void bdrv_info(Monitor *mon, QObject **ret_data)
#ifdef CONFIG_BLOCK_IO_THROTTLING
ThrottleConfig cfg;
throttle_get_config(&bs->throttle_state, &cfg);
- int64_t bps, bps_rd, bps_wr;
- int64_t iops, iops_rd, iops_wr;
+ int64_t bps = 0, bps_rd = 0, bps_wr = 0;
+ int64_t iops = 0, iops_rd = 0, iops_wr = 0;
- bps = cfg.buckets[THROTTLE_BPS_TOTAL].avg;
- bps_rd = cfg.buckets[THROTTLE_BPS_READ].avg;
- bps_wr = cfg.buckets[THROTTLE_BPS_WRITE].avg;
- iops = cfg.buckets[THROTTLE_OPS_TOTAL].avg;
- iops_rd = cfg.buckets[THROTTLE_OPS_READ].avg;
- iops_wr = cfg.buckets[THROTTLE_OPS_WRITE].avg;
+ if (bs->io_limits_enabled) {
+ bps = cfg.buckets[THROTTLE_BPS_TOTAL].avg;
+ bps_rd = cfg.buckets[THROTTLE_BPS_READ].avg;
+ bps_wr = cfg.buckets[THROTTLE_BPS_WRITE].avg;
+ iops = cfg.buckets[THROTTLE_OPS_TOTAL].avg;
+ iops_rd = cfg.buckets[THROTTLE_OPS_READ].avg;
+ iops_wr = cfg.buckets[THROTTLE_OPS_WRITE].avg;
+ }
obj = qobject_from_jsonf("{ 'file': %s, 'ro': %i, 'drv': %s, "
"'encrypted': %i, "
--
2.1.0