* [Bug 1939179] [NEW] qemu-ga fsfreeze crashes the kernel
@ 2021-08-06 22:19 Arthur Lyubochenya
2021-08-09 7:00 ` [Bug 1939179] " Thomas Huth
2021-08-09 9:42 ` Thomas Huth
0 siblings, 2 replies; 3+ messages in thread
From: Arthur Lyubochenya @ 2021-08-06 22:19 UTC (permalink / raw
To: qemu-devel
Public bug reported:
Hello,
Still required your attention, duplicate from:
https://bugs.launchpad.net/bugs/1807073
https://bugs.launchpad.net/bugs/1813045
We use mainly Cloudlinux, Debian and Centos.
We experienced many crashes on our qemu instances based on Cloudlinux during a snapshot.
The issue is not related to CloudLinux directly, but to Qemu agent, which does not freeze the file system(s) correctly. What is actually happening:
When VM backup is invoked, Qemu agent freezes the file systems, so no single change will be made during the backup. But Qemu agent does not respect the loop* devices in freezing order (we have checked its sources), which leads to the next situation:
1) freeze loopback fs
---> send async reqs to loopback thread
2) freeze main fs
3) loopback thread wakes up and trying to write data to the main fs, which is still frozen, and this finally leads to the hung task and kernel crash.
Moreover, a lot of Proxmox users are complaining about the issue as well:
https://forum.proxmox.com/threads/error-vm-100-qmp-command-guest-fsfreeze-thaw-failed-got-timeout.68082/
https://forum.proxmox.com/threads/problem-with-fsfreeze-freeze-and-qemu-guest-agent.65707/
** Affects: qemu
Importance: Undecided
Status: New
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https://bugs.launchpad.net/bugs/1939179
Title:
qemu-ga fsfreeze crashes the kernel
Status in QEMU:
New
Bug description:
Hello,
Still required your attention, duplicate from:
https://bugs.launchpad.net/bugs/1807073
https://bugs.launchpad.net/bugs/1813045
We use mainly Cloudlinux, Debian and Centos.
We experienced many crashes on our qemu instances based on Cloudlinux during a snapshot.
The issue is not related to CloudLinux directly, but to Qemu agent, which does not freeze the file system(s) correctly. What is actually happening:
When VM backup is invoked, Qemu agent freezes the file systems, so no single change will be made during the backup. But Qemu agent does not respect the loop* devices in freezing order (we have checked its sources), which leads to the next situation:
1) freeze loopback fs
---> send async reqs to loopback thread
2) freeze main fs
3) loopback thread wakes up and trying to write data to the main fs, which is still frozen, and this finally leads to the hung task and kernel crash.
Moreover, a lot of Proxmox users are complaining about the issue as well:
https://forum.proxmox.com/threads/error-vm-100-qmp-command-guest-fsfreeze-thaw-failed-got-timeout.68082/
https://forum.proxmox.com/threads/problem-with-fsfreeze-freeze-and-qemu-guest-agent.65707/
To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1939179/+subscriptions
^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug 1939179] Re: qemu-ga fsfreeze crashes the kernel
2021-08-06 22:19 [Bug 1939179] [NEW] qemu-ga fsfreeze crashes the kernel Arthur Lyubochenya
@ 2021-08-09 7:00 ` Thomas Huth
2021-08-09 9:42 ` Thomas Huth
1 sibling, 0 replies; 3+ messages in thread
From: Thomas Huth @ 2021-08-09 7:00 UTC (permalink / raw
To: qemu-devel
We are currently in progress of retiring this bug tracker here... could
you please open a new ticket on gitlab instead:
https://gitlab.com/qemu-project/qemu/-/issues
Thanks and sorry for the inconvenience.
** Changed in: qemu
Status: New => Incomplete
--
You received this bug notification because you are a member of qemu-
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https://bugs.launchpad.net/bugs/1939179
Title:
qemu-ga fsfreeze crashes the kernel
Status in QEMU:
Incomplete
Bug description:
Hello,
Still required your attention, duplicate from:
https://bugs.launchpad.net/bugs/1807073
https://bugs.launchpad.net/bugs/1813045
We use mainly Cloudlinux, Debian and Centos.
We experienced many crashes on our qemu instances based on Cloudlinux during a snapshot.
The issue is not related to CloudLinux directly, but to Qemu agent, which does not freeze the file system(s) correctly. What is actually happening:
When VM backup is invoked, Qemu agent freezes the file systems, so no single change will be made during the backup. But Qemu agent does not respect the loop* devices in freezing order (we have checked its sources), which leads to the next situation:
1) freeze loopback fs
---> send async reqs to loopback thread
2) freeze main fs
3) loopback thread wakes up and trying to write data to the main fs, which is still frozen, and this finally leads to the hung task and kernel crash.
Moreover, a lot of Proxmox users are complaining about the issue as well:
https://forum.proxmox.com/threads/error-vm-100-qmp-command-guest-fsfreeze-thaw-failed-got-timeout.68082/
https://forum.proxmox.com/threads/problem-with-fsfreeze-freeze-and-qemu-guest-agent.65707/
To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1939179/+subscriptions
^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug 1939179] Re: qemu-ga fsfreeze crashes the kernel
2021-08-06 22:19 [Bug 1939179] [NEW] qemu-ga fsfreeze crashes the kernel Arthur Lyubochenya
2021-08-09 7:00 ` [Bug 1939179] " Thomas Huth
@ 2021-08-09 9:42 ` Thomas Huth
1 sibling, 0 replies; 3+ messages in thread
From: Thomas Huth @ 2021-08-09 9:42 UTC (permalink / raw
To: qemu-devel
https://gitlab.com/qemu-project/qemu/-/issues/520
... thanks!
** Bug watch added: gitlab.com/qemu-project/qemu/-/issues #520
https://gitlab.com/qemu-project/qemu/-/issues/520
** Changed in: qemu
Status: Incomplete => Invalid
--
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1939179
Title:
qemu-ga fsfreeze crashes the kernel
Status in QEMU:
Invalid
Bug description:
Hello,
Still required your attention, duplicate from:
https://bugs.launchpad.net/bugs/1807073
https://bugs.launchpad.net/bugs/1813045
We use mainly Cloudlinux, Debian and Centos.
We experienced many crashes on our qemu instances based on Cloudlinux during a snapshot.
The issue is not related to CloudLinux directly, but to Qemu agent, which does not freeze the file system(s) correctly. What is actually happening:
When VM backup is invoked, Qemu agent freezes the file systems, so no single change will be made during the backup. But Qemu agent does not respect the loop* devices in freezing order (we have checked its sources), which leads to the next situation:
1) freeze loopback fs
---> send async reqs to loopback thread
2) freeze main fs
3) loopback thread wakes up and trying to write data to the main fs, which is still frozen, and this finally leads to the hung task and kernel crash.
Moreover, a lot of Proxmox users are complaining about the issue as well:
https://forum.proxmox.com/threads/error-vm-100-qmp-command-guest-fsfreeze-thaw-failed-got-timeout.68082/
https://forum.proxmox.com/threads/problem-with-fsfreeze-freeze-and-qemu-guest-agent.65707/
To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1939179/+subscriptions
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2021-08-09 9:54 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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2021-08-06 22:19 [Bug 1939179] [NEW] qemu-ga fsfreeze crashes the kernel Arthur Lyubochenya
2021-08-09 7:00 ` [Bug 1939179] " Thomas Huth
2021-08-09 9:42 ` Thomas Huth
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