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

3 files changed, 30 insertions, 8 deletions

diff --git a/pkg/sentry/mm/BUILD b/pkg/sentry/mm/BUILD
index f9d0837a1..b4a47ccca 100644
--- a/pkg/sentry/mm/BUILD
+++ b/pkg/sentry/mm/BUILD
@@ -73,12 +73,35 @@ go_template_instance(
     },
 )
 
+go_template_instance(
+    name = "aio_mappable_refs",
+    out = "aio_mappable_refs.go",
+    package = "mm",
+    prefix = "aioMappable",
+    template = "//pkg/refs_vfs2:refs_template",
+    types = {
+        "T": "aioMappable",
+    },
+)
+
+go_template_instance(
+    name = "special_mappable_refs",
+    out = "special_mappable_refs.go",
+    package = "mm",
+    prefix = "SpecialMappable",
+    template = "//pkg/refs_vfs2:refs_template",
+    types = {
+        "T": "SpecialMappable",
+    },
+)
+
 go_library(
     name = "mm",
     srcs = [
         "address_space.go",
         "aio_context.go",
         "aio_context_state.go",
+        "aio_mappable_refs.go",
         "debug.go",
         "file_refcount_set.go",
         "io.go",
@@ -92,6 +115,7 @@ go_library(
         "save_restore.go",
         "shm.go",
         "special_mappable.go",
+        "special_mappable_refs.go",
         "syscalls.go",
         "vma.go",
         "vma_set.go",
diff --git a/pkg/sentry/mm/aio_context.go b/pkg/sentry/mm/aio_context.go
index 16fea53c4..7bf48cb2c 100644
--- a/pkg/sentry/mm/aio_context.go
+++ b/pkg/sentry/mm/aio_context.go
@@ -17,7 +17,6 @@ package mm
 import (
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/context"
-	"gvisor.dev/gvisor/pkg/refs"
 	"gvisor.dev/gvisor/pkg/sentry/memmap"
 	"gvisor.dev/gvisor/pkg/sentry/pgalloc"
 	"gvisor.dev/gvisor/pkg/sentry/usage"
@@ -239,7 +238,7 @@ func (ctx *AIOContext) Drain() {
 //
 // +stateify savable
 type aioMappable struct {
-	refs.AtomicRefCount
+	aioMappableRefs
 
 	mfp pgalloc.MemoryFileProvider
 	fr  memmap.FileRange
@@ -253,13 +252,13 @@ func newAIOMappable(mfp pgalloc.MemoryFileProvider) (*aioMappable, error) {
 		return nil, err
 	}
 	m := aioMappable{mfp: mfp, fr: fr}
-	m.EnableLeakCheck("mm.aioMappable")
+	m.EnableLeakCheck()
 	return &m, nil
 }
 
 // DecRef implements refs.RefCounter.DecRef.
 func (m *aioMappable) DecRef(ctx context.Context) {
-	m.AtomicRefCount.DecRefWithDestructor(ctx, func(context.Context) {
+	m.aioMappableRefs.DecRef(func() {
 		m.mfp.MemoryFile().DecRef(m.fr)
 	})
 }
diff --git a/pkg/sentry/mm/special_mappable.go b/pkg/sentry/mm/special_mappable.go
index 4cdb52eb6..f4c93baeb 100644
--- a/pkg/sentry/mm/special_mappable.go
+++ b/pkg/sentry/mm/special_mappable.go
@@ -16,7 +16,6 @@ package mm
 
 import (
 	"gvisor.dev/gvisor/pkg/context"
-	"gvisor.dev/gvisor/pkg/refs"
 	"gvisor.dev/gvisor/pkg/sentry/memmap"
 	"gvisor.dev/gvisor/pkg/sentry/pgalloc"
 	"gvisor.dev/gvisor/pkg/sentry/usage"
@@ -31,7 +30,7 @@ import (
 //
 // +stateify savable
 type SpecialMappable struct {
-	refs.AtomicRefCount
+	SpecialMappableRefs
 
 	mfp  pgalloc.MemoryFileProvider
 	fr   memmap.FileRange
@@ -45,13 +44,13 @@ type SpecialMappable struct {
 // Preconditions: fr.Length() != 0.
 func NewSpecialMappable(name string, mfp pgalloc.MemoryFileProvider, fr memmap.FileRange) *SpecialMappable {
 	m := SpecialMappable{mfp: mfp, fr: fr, name: name}
-	m.EnableLeakCheck("mm.SpecialMappable")
+	m.EnableLeakCheck()
 	return &m
 }
 
 // DecRef implements refs.RefCounter.DecRef.
 func (m *SpecialMappable) DecRef(ctx context.Context) {
-	m.AtomicRefCount.DecRefWithDestructor(ctx, func(context.Context) {
+	m.SpecialMappableRefs.DecRef(func() {
 		m.mfp.MemoryFile().DecRef(m.fr)
 	})
 }