diff options
Diffstat (limited to 'pkg/sentry/fsimpl/gofer/special_file.go')
| -rw-r--r-- | pkg/sentry/fsimpl/gofer/special_file.go | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/pkg/sentry/fsimpl/gofer/special_file.go b/pkg/sentry/fsimpl/gofer/special_file.go index 29afb67d9..4b59c1c3c 100644 --- a/pkg/sentry/fsimpl/gofer/special_file.go +++ b/pkg/sentry/fsimpl/gofer/special_file.go @@ -42,6 +42,11 @@ import ( type specialFileFD struct { fileDescription + // releaseMu synchronizes the closing of fd.handle with fd.sync(). It's safe + // to access fd.handle without locking for operations that require a ref to + // be held by the caller, e.g. vfs.FileDescriptionImpl implementations. + releaseMu sync.RWMutex `state:"nosave"` + // handle is used for file I/O. handle is immutable. handle handle `state:"nosave"` @@ -117,7 +122,10 @@ func (fd *specialFileFD) Release(ctx context.Context) { if fd.haveQueue { fdnotifier.RemoveFD(fd.handle.fd) } + fd.releaseMu.Lock() fd.handle.close(ctx) + fd.releaseMu.Unlock() + fs := fd.vfsfd.Mount().Filesystem().Impl().(*filesystem) fs.syncMu.Lock() delete(fs.specialFileFDs, fd) @@ -373,6 +381,13 @@ func (fd *specialFileFD) Sync(ctx context.Context) error { } func (fd *specialFileFD) sync(ctx context.Context, forFilesystemSync bool) error { + // Locks to ensure it didn't race with fd.Release(). + fd.releaseMu.RLock() + defer fd.releaseMu.RUnlock() + + if !fd.handle.isOpen() { + return nil + } err := func() error { // If we have a host FD, fsyncing it is likely to be faster than an fsync // RPC. |