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It can be accessed and reviewed at: https://github.com/lxc/lxd/pull/7011
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=== Description (from pull-request) ===
Signed-off-by: Christian Brauner <christian.brau...@ubuntu.com>
From 146e6a80542fc4623af13f47126f036d7a940e7a Mon Sep 17 00:00:00 2001
From: Christian Brauner <christian.brau...@ubuntu.com>
Date: Thu, 12 Mar 2020 11:33:05 +0100
Subject: [PATCH 1/2] driver_qemu: delete vm id from vmConsole
Otherwise I'd expect the map to be growing.
Signed-off-by: Christian Brauner <christian.brau...@ubuntu.com>
---
lxd/instance/drivers/driver_qemu.go | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/lxd/instance/drivers/driver_qemu.go
b/lxd/instance/drivers/driver_qemu.go
index 3c83c55619..6c937be053 100644
--- a/lxd/instance/drivers/driver_qemu.go
+++ b/lxd/instance/drivers/driver_qemu.go
@@ -3161,7 +3161,7 @@ func (vm *qemu) Console() (*os.File, chan error, error) {
<-chDisconnect
vmConsoleLock.Lock()
- vmConsole[vm.id] = false
+ delete(vmConsole, vm.id)
vmConsoleLock.Unlock()
}()
From a95bf4d5671dd91bd74280f1d0a60a4bb76f5a27 Mon Sep 17 00:00:00 2001
From: Christian Brauner <christian.brau...@ubuntu.com>
Date: Thu, 12 Mar 2020 11:53:26 +0100
Subject: [PATCH 2/2] ExecReaderToChannel: Prevent endless loops
Well, there's a bug in ExecReaderToChannel() where we can end up in an endless
loop when the error we get from poll() is non-transient. Realistically, when
poll() returns -1 it means something is so wrong we can't recover from it and a
next call to poll() won't be any better. If we get POLLNVAL that's pretty
obvious that the fd has been closed and so this is guaranteed to end up in an
endless loop. If we get POLLERR we could maybe maybe argue that there's
something we can do but realistically, not really. So exit in all those cases.
(Note, that we've never hit this problem before with containers. It suddenly
started appearing when the lxd-agent became a thing.)
Closes #6870.
Signed-off-by: Christian Brauner <christian.brau...@ubuntu.com>
---
shared/util_linux_cgo.go | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/shared/util_linux_cgo.go b/shared/util_linux_cgo.go
index 1914ff1002..45f7c03e22 100644
--- a/shared/util_linux_cgo.go
+++ b/shared/util_linux_cgo.go
@@ -325,16 +325,24 @@ func ExecReaderToChannel(r io.Reader, bufferSize int,
exited <-chan bool, fd int
ret, revents, err := GetPollRevents(fd, 0, (POLLIN | POLLPRI |
POLLERR | POLLHUP | POLLRDHUP | POLLNVAL))
if ret < 0 {
logger.Errorf("Failed to poll(POLLIN | POLLPRI |
POLLHUP | POLLRDHUP) on file descriptor: %s.", err)
+ // Something went wrong so let's exited otherwise we
+ // end up in an endless loop.
+ once.Do(closeChannel)
} else if ret > 0 {
if (revents & POLLERR) > 0 {
logger.Warnf("Detected poll(POLLERR) event.")
+ // Read end has likely been closed so again,
+ // avoid an endless loop.
+ once.Do(closeChannel)
} else if (revents & POLLNVAL) > 0 {
logger.Warnf("Detected poll(POLLNVAL) event.")
+ // Well, someone closed the fd havent they? So
+ // let's go home.
+ once.Do(closeChannel)
}
} else if ret == 0 {
logger.Debugf("No data in stdout: exiting.")
once.Do(closeChannel)
- return
}
}()
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