Port aio to VFS2.

In order to make sure all aio goroutines have stopped during S/R, a new
WaitGroup was added to TaskSet, analagous to runningGoroutines. This WaitGroup
is incremented with each aio goroutine, and waited on during kernel.Pause.

The old VFS1 aio code was changed to use this new WaitGroup, rather than
fs.Async. The only uses of fs.Async are now inode and mount Release operations,
which do not call fs.Async recursively. This fixes a lock-ordering violation
that can cause deadlocks.

Updates #1035.

PiperOrigin-RevId: 316689380

1 files changed, 0 insertions, 53 deletions

diff --git a/pkg/sentry/kernel/context.go b/pkg/sentry/kernel/context.go
index 0c40bf315..dd5f0f5fa 100644
--- a/pkg/sentry/kernel/context.go
+++ b/pkg/sentry/kernel/context.go
@@ -18,7 +18,6 @@ import (
 	"time"
 
 	"gvisor.dev/gvisor/pkg/context"
-	"gvisor.dev/gvisor/pkg/log"
 )
 
 // contextID is the kernel package's type for context.Context.Value keys.
@@ -113,55 +112,3 @@ func (*Task) Done() <-chan struct{} {
 func (*Task) Err() error {
 	return nil
 }
-
-// AsyncContext returns a context.Context that may be used by goroutines that
-// do work on behalf of t and therefore share its contextual values, but are
-// not t's task goroutine (e.g. asynchronous I/O).
-func (t *Task) AsyncContext() context.Context {
-	return taskAsyncContext{t: t}
-}
-
-type taskAsyncContext struct {
-	context.NoopSleeper
-	t *Task
-}
-
-// Debugf implements log.Logger.Debugf.
-func (ctx taskAsyncContext) Debugf(format string, v ...interface{}) {
-	ctx.t.Debugf(format, v...)
-}
-
-// Infof implements log.Logger.Infof.
-func (ctx taskAsyncContext) Infof(format string, v ...interface{}) {
-	ctx.t.Infof(format, v...)
-}
-
-// Warningf implements log.Logger.Warningf.
-func (ctx taskAsyncContext) Warningf(format string, v ...interface{}) {
-	ctx.t.Warningf(format, v...)
-}
-
-// IsLogging implements log.Logger.IsLogging.
-func (ctx taskAsyncContext) IsLogging(level log.Level) bool {
-	return ctx.t.IsLogging(level)
-}
-
-// Deadline implements context.Context.Deadline.
-func (ctx taskAsyncContext) Deadline() (time.Time, bool) {
-	return ctx.t.Deadline()
-}
-
-// Done implements context.Context.Done.
-func (ctx taskAsyncContext) Done() <-chan struct{} {
-	return ctx.t.Done()
-}
-
-// Err implements context.Context.Err.
-func (ctx taskAsyncContext) Err() error {
-	return ctx.t.Err()
-}
-
-// Value implements context.Context.Value.
-func (ctx taskAsyncContext) Value(key interface{}) interface{} {
-	return ctx.t.Value(key)
-}