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authorgVisor bot <gvisor-bot@google.com>2019-08-02 20:57:13 +0000
committergVisor bot <gvisor-bot@google.com>2019-08-02 20:57:13 +0000
commit15041d177271e6373941d372b8bd2e29db28b125 (patch)
tree5bd2c0e31b3db71ed053aa483e646f8650b1f76c /runsc
parenta0ddb482614af1a079ef547adae40bc50810f636 (diff)
parentb461be88a8036ca0455aceb8b6c723d6b6fded4f (diff)
Merge b461be88 (automated)
Diffstat (limited to 'runsc')
-rw-r--r--runsc/boot/controller.go2
-rw-r--r--runsc/boot/fs.go6
-rw-r--r--runsc/boot/loader.go92
-rw-r--r--runsc/specutils/specutils.go11
4 files changed, 86 insertions, 25 deletions
diff --git a/runsc/boot/controller.go b/runsc/boot/controller.go
index f1e4a9ba4..0285f599d 100644
--- a/runsc/boot/controller.go
+++ b/runsc/boot/controller.go
@@ -347,7 +347,7 @@ func (cm *containerManager) Restore(o *RestoreOpts, _ *struct{}) error {
cm.l.k = k
// Set up the restore environment.
- mntr := newContainerMounter(cm.l.spec, "", cm.l.goferFDs, cm.l.k, cm.l.mountHints)
+ mntr := newContainerMounter(cm.l.spec, cm.l.goferFDs, cm.l.k, cm.l.mountHints)
renv, err := mntr.createRestoreEnvironment(cm.l.conf)
if err != nil {
return fmt.Errorf("creating RestoreEnvironment: %v", err)
diff --git a/runsc/boot/fs.go b/runsc/boot/fs.go
index 98ce40991..b6eeacf98 100644
--- a/runsc/boot/fs.go
+++ b/runsc/boot/fs.go
@@ -476,9 +476,6 @@ func (p *podMountHints) findMount(mount specs.Mount) *mountHint {
}
type containerMounter struct {
- // cid is the container ID. May be set to empty for the root container.
- cid string
-
root *specs.Root
// mounts is the set of submounts for the container. It's a copy from the spec
@@ -493,9 +490,8 @@ type containerMounter struct {
hints *podMountHints
}
-func newContainerMounter(spec *specs.Spec, cid string, goferFDs []int, k *kernel.Kernel, hints *podMountHints) *containerMounter {
+func newContainerMounter(spec *specs.Spec, goferFDs []int, k *kernel.Kernel, hints *podMountHints) *containerMounter {
return &containerMounter{
- cid: cid,
root: spec.Root,
mounts: compileMounts(spec),
fds: fdDispenser{fds: goferFDs},
diff --git a/runsc/boot/loader.go b/runsc/boot/loader.go
index 77e1aa456..434f1ca77 100644
--- a/runsc/boot/loader.go
+++ b/runsc/boot/loader.go
@@ -27,6 +27,7 @@ import (
gtime "time"
specs "github.com/opencontainers/runtime-spec/specs-go"
+ "golang.org/x/sys/unix"
"gvisor.dev/gvisor/pkg/abi/linux"
"gvisor.dev/gvisor/pkg/cpuid"
"gvisor.dev/gvisor/pkg/log"
@@ -524,11 +525,9 @@ func (l *Loader) run() error {
// ours either way.
l.rootProcArgs.FDTable = fdTable
- // cid for root container can be empty. Only subcontainers need it to set
- // the mount location.
- mntr := newContainerMounter(l.spec, "", l.goferFDs, l.k, l.mountHints)
-
- // Setup the root container.
+ // Setup the root container file system.
+ l.startGoferMonitor(l.sandboxID, l.goferFDs)
+ mntr := newContainerMounter(l.spec, l.goferFDs, l.k, l.mountHints)
if err := mntr.setupRootContainer(ctx, ctx, l.conf, func(mns *fs.MountNamespace) {
l.rootProcArgs.MountNamespace = mns
}); err != nil {
@@ -687,7 +686,9 @@ func (l *Loader) startContainer(spec *specs.Spec, conf *Config, cid string, file
goferFDs = append(goferFDs, fd)
}
- mntr := newContainerMounter(spec, cid, goferFDs, l.k, l.mountHints)
+ // Setup the child container file system.
+ l.startGoferMonitor(cid, goferFDs)
+ mntr := newContainerMounter(spec, goferFDs, l.k, l.mountHints)
if err := mntr.setupChildContainer(conf, &procArgs); err != nil {
return fmt.Errorf("configuring container FS: %v", err)
}
@@ -710,17 +711,59 @@ func (l *Loader) startContainer(spec *specs.Spec, conf *Config, cid string, file
return nil
}
+// startGoferMonitor runs a goroutine to monitor gofer's health. It polls on
+// the gofer FDs looking for disconnects, and destroys the container if a
+// disconnect occurs in any of the gofer FDs.
+func (l *Loader) startGoferMonitor(cid string, goferFDs []int) {
+ go func() {
+ log.Debugf("Monitoring gofer health for container %q", cid)
+ var events []unix.PollFd
+ for _, fd := range goferFDs {
+ events = append(events, unix.PollFd{
+ Fd: int32(fd),
+ Events: unix.POLLHUP | unix.POLLRDHUP,
+ })
+ }
+ _, _, err := specutils.RetryEintr(func() (uintptr, uintptr, error) {
+ // Use ppoll instead of poll because it's already whilelisted in seccomp.
+ n, err := unix.Ppoll(events, nil, nil)
+ return uintptr(n), 0, err
+ })
+ if err != nil {
+ panic(fmt.Sprintf("Error monitoring gofer FDs: %v", err))
+ }
+
+ // Check if the gofer has stopped as part of normal container destruction.
+ // This is done just to avoid sending an annoying error message to the log.
+ // Note that there is a small race window in between mu.Unlock() and the
+ // lock being reacquired in destroyContainer(), but it's harmless to call
+ // destroyContainer() multiple times.
+ l.mu.Lock()
+ _, ok := l.processes[execID{cid: cid}]
+ l.mu.Unlock()
+ if ok {
+ log.Infof("Gofer socket disconnected, destroying container %q", cid)
+ if err := l.destroyContainer(cid); err != nil {
+ log.Warningf("Error destroying container %q after gofer stopped: %v", cid, err)
+ }
+ }
+ }()
+}
+
// destroyContainer stops a container if it is still running and cleans up its
// filesystem.
func (l *Loader) destroyContainer(cid string) error {
l.mu.Lock()
defer l.mu.Unlock()
- // Has the container started?
- _, _, err := l.threadGroupFromIDLocked(execID{cid: cid})
+ _, _, started, err := l.threadGroupFromIDLocked(execID{cid: cid})
+ if err != nil {
+ // Container doesn't exist.
+ return err
+ }
- // If the container has started, kill and wait for all processes.
- if err == nil {
+ // The container exists, has it been started?
+ if started {
if err := l.signalAllProcesses(cid, int32(linux.SIGKILL)); err != nil {
return fmt.Errorf("sending SIGKILL to all container processes: %v", err)
}
@@ -754,9 +797,12 @@ func (l *Loader) executeAsync(args *control.ExecArgs) (kernel.ThreadID, error) {
l.mu.Lock()
defer l.mu.Unlock()
- tg, _, err := l.threadGroupFromIDLocked(execID{cid: args.ContainerID})
+ tg, _, started, err := l.threadGroupFromIDLocked(execID{cid: args.ContainerID})
if err != nil {
- return 0, fmt.Errorf("no such container: %q", args.ContainerID)
+ return 0, err
+ }
+ if !started {
+ return 0, fmt.Errorf("container %q not started", args.ContainerID)
}
// Get the container MountNamespace from the Task.
@@ -1018,22 +1064,30 @@ func (l *Loader) signalAllProcesses(cid string, signo int32) error {
func (l *Loader) threadGroupFromID(key execID) (*kernel.ThreadGroup, *host.TTYFileOperations, error) {
l.mu.Lock()
defer l.mu.Unlock()
- return l.threadGroupFromIDLocked(key)
+ tg, tty, ok, err := l.threadGroupFromIDLocked(key)
+ if err != nil {
+ return nil, nil, err
+ }
+ if !ok {
+ return nil, nil, fmt.Errorf("container %q not started", key.cid)
+ }
+ return tg, tty, nil
}
// threadGroupFromIDLocked returns the thread group and TTY for the given
// execution ID. TTY may be nil if the process is not attached to a terminal.
-// Returns error if execution ID is invalid or if container/process has not
-// started yet. Caller must hold 'mu'.
-func (l *Loader) threadGroupFromIDLocked(key execID) (*kernel.ThreadGroup, *host.TTYFileOperations, error) {
+// Also returns a boolean indicating whether the container has already started.
+// Returns error if execution ID is invalid or if the container cannot be
+// found (maybe it has been deleted). Caller must hold 'mu'.
+func (l *Loader) threadGroupFromIDLocked(key execID) (*kernel.ThreadGroup, *host.TTYFileOperations, bool, error) {
ep := l.processes[key]
if ep == nil {
- return nil, nil, fmt.Errorf("container not found")
+ return nil, nil, false, fmt.Errorf("container %q not found", key.cid)
}
if ep.tg == nil {
- return nil, nil, fmt.Errorf("container not started")
+ return nil, nil, false, nil
}
- return ep.tg, ep.tty, nil
+ return ep.tg, ep.tty, true, nil
}
func init() {
diff --git a/runsc/specutils/specutils.go b/runsc/specutils/specutils.go
index 0b40e38a3..2eec92349 100644
--- a/runsc/specutils/specutils.go
+++ b/runsc/specutils/specutils.go
@@ -492,3 +492,14 @@ func (c *Cleanup) Clean() {
func (c *Cleanup) Release() {
c.clean = nil
}
+
+// RetryEintr retries the function until an error different than EINTR is
+// returned.
+func RetryEintr(f func() (uintptr, uintptr, error)) (uintptr, uintptr, error) {
+ for {
+ r1, r2, err := f()
+ if err != syscall.EINTR {
+ return r1, r2, err
+ }
+ }
+}