Implement pipe(2) and pipe2(2) for VFS2.

Updates #1035

PiperOrigin-RevId: 306968644

3 files changed, 3 insertions, 24 deletions

diff --git a/pkg/sentry/fsimpl/tmpfs/filesystem.go b/pkg/sentry/fsimpl/tmpfs/filesystem.go
index f4d50d64f..660f5a29b 100644
--- a/pkg/sentry/fsimpl/tmpfs/filesystem.go
+++ b/pkg/sentry/fsimpl/tmpfs/filesystem.go
@@ -392,7 +392,7 @@ func (d *dentry) open(ctx context.Context, rp *vfs.ResolvingPath, opts *vfs.Open
 		// Can't open symlinks without O_PATH (which is unimplemented).
 		return nil, syserror.ELOOP
 	case *namedPipe:
-		return newNamedPipeFD(ctx, impl, rp, &d.vfsd, opts.Flags)
+		return impl.pipe.Open(ctx, rp.Mount(), &d.vfsd, opts.Flags)
 	case *deviceFile:
 		return rp.VirtualFilesystem().OpenDeviceSpecialFile(ctx, rp.Mount(), &d.vfsd, impl.kind, impl.major, impl.minor, opts)
 	case *socketFile:
diff --git a/pkg/sentry/fsimpl/tmpfs/named_pipe.go b/pkg/sentry/fsimpl/tmpfs/named_pipe.go
index 2c5c739df..8d77b3fa8 100644
--- a/pkg/sentry/fsimpl/tmpfs/named_pipe.go
+++ b/pkg/sentry/fsimpl/tmpfs/named_pipe.go
@@ -16,10 +16,8 @@ package tmpfs
 
 import (
 	"gvisor.dev/gvisor/pkg/abi/linux"
-	"gvisor.dev/gvisor/pkg/context"
 	"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
 	"gvisor.dev/gvisor/pkg/sentry/kernel/pipe"
-	"gvisor.dev/gvisor/pkg/sentry/vfs"
 	"gvisor.dev/gvisor/pkg/usermem"
 )
 
@@ -33,27 +31,8 @@ type namedPipe struct {
 //   * fs.mu must be locked.
 //   * rp.Mount().CheckBeginWrite() has been called successfully.
 func (fs *filesystem) newNamedPipe(creds *auth.Credentials, mode linux.FileMode) *inode {
-	file := &namedPipe{pipe: pipe.NewVFSPipe(pipe.DefaultPipeSize, usermem.PageSize)}
+	file := &namedPipe{pipe: pipe.NewVFSPipe(true /* isNamed */, pipe.DefaultPipeSize, usermem.PageSize)}
 	file.inode.init(file, fs, creds, linux.S_IFIFO|mode)
 	file.inode.nlink = 1 // Only the parent has a link.
 	return &file.inode
 }
-
-// namedPipeFD implements vfs.FileDescriptionImpl. Methods are implemented
-// entirely via struct embedding.
-type namedPipeFD struct {
-	fileDescription
-
-	*pipe.VFSPipeFD
-}
-
-func newNamedPipeFD(ctx context.Context, np *namedPipe, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, flags uint32) (*vfs.FileDescription, error) {
-	var err error
-	var fd namedPipeFD
-	fd.VFSPipeFD, err = np.pipe.NewVFSPipeFD(ctx, vfsd, &fd.vfsfd, flags)
-	if err != nil {
-		return nil, err
-	}
-	fd.vfsfd.Init(&fd, flags, rp.Mount(), vfsd, &vfs.FileDescriptionOptions{})
-	return &fd.vfsfd, nil
-}
diff --git a/pkg/sentry/fsimpl/tmpfs/tmpfs.go b/pkg/sentry/fsimpl/tmpfs/tmpfs.go
index 9fa8637d5..a59b24d45 100644
--- a/pkg/sentry/fsimpl/tmpfs/tmpfs.go
+++ b/pkg/sentry/fsimpl/tmpfs/tmpfs.go
@@ -357,6 +357,7 @@ func (i *inode) setStat(ctx context.Context, creds *auth.Credentials, stat *linu
 		return err
 	}
 	i.mu.Lock()
+	defer i.mu.Unlock()
 	var (
 		needsMtimeBump bool
 		needsCtimeBump bool
@@ -427,7 +428,6 @@ func (i *inode) setStat(ctx context.Context, creds *auth.Credentials, stat *linu
 		atomic.StoreInt64(&i.ctime, now)
 	}
 
-	i.mu.Unlock()
 	return nil
 }