Implement ioctl(FIOASYNC)

FIOASYNC and friends are used to send signals when a file is ready for IO.

This may or may not be needed by Nginx. While Nginx does use it, it is unclear
if the code that uses it has any effect.

PiperOrigin-RevId: 201550828
Change-Id: I7ba05a7db4eb2dfffde11e9bd9a35b65b98d7f50

1 files changed, 7 insertions, 0 deletions

diff --git a/pkg/sentry/fs/flags.go b/pkg/sentry/fs/flags.go
index dfa6a3d62..7a8eefd02 100644
--- a/pkg/sentry/fs/flags.go
+++ b/pkg/sentry/fs/flags.go
@@ -42,6 +42,9 @@ type FileFlags struct {
 
 	// Directory indicates that this file must be a directory.
 	Directory bool
+
+	// Async indicates that this file sends signals on IO events.
+	Async bool
 }
 
 // SettableFileFlags is a subset of FileFlags above that can be changed
@@ -55,6 +58,9 @@ type SettableFileFlags struct {
 
 	// Append indicates this file is append only.
 	Append bool
+
+	// Async indicates that this file sends signals on IO events.
+	Async bool
 }
 
 // Settable returns the subset of f that are settable.
@@ -63,5 +69,6 @@ func (f FileFlags) Settable() SettableFileFlags {
 		Direct:      f.Direct,
 		NonBlocking: f.NonBlocking,
 		Append:      f.Append,
+		Async:       f.Async,
 	}
 }