Use new reference count utility throughout gvisor.

This uses the refs_vfs2 template in vfs2 as well as objects common to vfs1 and
vfs2. Note that vfs1-only refcounts are not replaced, since vfs1 will be deleted
soon anyway.

The following structs now use the new tool, with leak check enabled:
devpts:rootInode
fuse:inode
kernfs:Dentry
kernfs:dir
kernfs:readonlyDir
kernfs:StaticDirectory
proc:fdDirInode
proc:fdInfoDirInode
proc:subtasksInode
proc:taskInode
proc:tasksInode
vfs:FileDescription
vfs:MountNamespace
vfs:Filesystem
sys:dir
kernel:FSContext
kernel:ProcessGroup
kernel:Session
shm:Shm
mm:aioMappable
mm:SpecialMappable
transport:queue

And the following use the template, but because they currently are not leak
checked, a TODO is left instead of enabling leak check in this patch:
kernel:FDTable
tun:tunEndpoint

Updates #1486.

PiperOrigin-RevId: 328460377

1 files changed, 7 insertions, 0 deletions

diff --git a/pkg/sentry/fsimpl/devpts/devpts.go b/pkg/sentry/fsimpl/devpts/devpts.go
index 3f3a099bd..0eaff9087 100644
--- a/pkg/sentry/fsimpl/devpts/devpts.go
+++ b/pkg/sentry/fsimpl/devpts/devpts.go
@@ -83,6 +83,7 @@ func (fstype FilesystemType) newFilesystem(vfsObj *vfs.VirtualFilesystem, creds
 	}
 	root.InodeAttrs.Init(creds, linux.UNNAMED_MAJOR, devMinor, 1, linux.ModeDirectory|0555)
 	root.OrderedChildren.Init(kernfs.OrderedChildrenOptions{})
+	root.EnableLeakCheck()
 	root.dentry.Init(root)
 
 	// Construct the pts master inode and dentry. Linux always uses inode
@@ -110,6 +111,7 @@ func (fs *filesystem) Release(ctx context.Context) {
 
 // rootInode is the root directory inode for the devpts mounts.
 type rootInode struct {
+	rootInodeRefs
 	kernfs.AlwaysValid
 	kernfs.InodeAttrs
 	kernfs.InodeDirectoryNoNewChildren
@@ -233,3 +235,8 @@ func (i *rootInode) IterDirents(ctx context.Context, cb vfs.IterDirentsCallback,
 	}
 	return offset, nil
 }
+
+// DecRef implements kernfs.Inode.
+func (i *rootInode) DecRef(context.Context) {
+	i.rootInodeRefs.DecRef(i.Destroy)
+}