diff options
| author | Dean Deng <deandeng@google.com> | 2020-11-09 08:30:29 -0800 |
|---|---|---|
| committer | gVisor bot <gvisor-bot@google.com> | 2020-11-09 08:33:17 -0800 |
| commit | 0fb5353e45f166460d5846576c20479072207a06 (patch) | |
| tree | f88e4472c07f56e4d34b14743e1a3afaafab62e1 /pkg/sentry/vfs/mount.go | |
| parent | 78cce3a46b953cab00731f8afacf7e9e7f4dc751 (diff) | |
Initialize references with a value of 1.
This lets us avoid treating a value of 0 as one reference. All references
using the refsvfs2 template must call InitRefs() before the reference is
incremented/decremented, or else a panic will occur. Therefore, it should be
pretty easy to identify missing InitRef calls during testing.
Updates #1486.
PiperOrigin-RevId: 341411151
Diffstat (limited to 'pkg/sentry/vfs/mount.go')
| -rw-r--r-- | pkg/sentry/vfs/mount.go | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/pkg/sentry/vfs/mount.go b/pkg/sentry/vfs/mount.go index 3ea981ad4..d865fd603 100644 --- a/pkg/sentry/vfs/mount.go +++ b/pkg/sentry/vfs/mount.go @@ -169,7 +169,7 @@ func (vfs *VirtualFilesystem) NewMountNamespace(ctx context.Context, creds *auth Owner: creds.UserNamespace, mountpoints: make(map[*Dentry]uint32), } - mntns.EnableLeakCheck() + mntns.InitRefs() mntns.root = newMount(vfs, fs, root, mntns, opts) return mntns, nil } @@ -477,7 +477,9 @@ func (mnt *Mount) tryIncMountedRef() bool { return false } if atomic.CompareAndSwapInt64(&mnt.refs, r, r+1) { - refsvfs2.LogTryIncRef(mnt, r+1) + if mnt.LogRefs() { + refsvfs2.LogTryIncRef(mnt, r+1) + } return true } } @@ -488,12 +490,17 @@ func (mnt *Mount) IncRef() { // In general, negative values for mnt.refs are valid because the MSB is // the eager-unmount bit. r := atomic.AddInt64(&mnt.refs, 1) - refsvfs2.LogIncRef(mnt, r) + if mnt.LogRefs() { + refsvfs2.LogIncRef(mnt, r) + } } // DecRef decrements mnt's reference count. func (mnt *Mount) DecRef(ctx context.Context) { r := atomic.AddInt64(&mnt.refs, -1) + if mnt.LogRefs() { + refsvfs2.LogDecRef(mnt, r) + } if r&^math.MinInt64 == 0 { // mask out MSB refsvfs2.Unregister(mnt) mnt.destroy(ctx) |