From 0fb5353e45f166460d5846576c20479072207a06 Mon Sep 17 00:00:00 2001 From: Dean Deng Date: Mon, 9 Nov 2020 08:30:29 -0800 Subject: 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 --- pkg/sentry/fsimpl/overlay/overlay.go | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) (limited to 'pkg/sentry/fsimpl/overlay/overlay.go') diff --git a/pkg/sentry/fsimpl/overlay/overlay.go b/pkg/sentry/fsimpl/overlay/overlay.go index 73130bc8d..3492409b2 100644 --- a/pkg/sentry/fsimpl/overlay/overlay.go +++ b/pkg/sentry/fsimpl/overlay/overlay.go @@ -514,7 +514,9 @@ func (d *dentry) IncRef() { // d.refs may be 0 if d.fs.renameMu is locked, which serializes against // d.checkDropLocked(). r := atomic.AddInt64(&d.refs, 1) - refsvfs2.LogIncRef(d, r) + if d.LogRefs() { + refsvfs2.LogIncRef(d, r) + } } // TryIncRef implements vfs.DentryImpl.TryIncRef. @@ -525,7 +527,9 @@ func (d *dentry) TryIncRef() bool { return false } if atomic.CompareAndSwapInt64(&d.refs, r, r+1) { - refsvfs2.LogTryIncRef(d, r+1) + if d.LogRefs() { + refsvfs2.LogTryIncRef(d, r+1) + } return true } } @@ -534,7 +538,9 @@ func (d *dentry) TryIncRef() bool { // DecRef implements vfs.DentryImpl.DecRef. func (d *dentry) DecRef(ctx context.Context) { r := atomic.AddInt64(&d.refs, -1) - refsvfs2.LogDecRef(d, r) + if d.LogRefs() { + refsvfs2.LogDecRef(d, r) + } if r == 0 { d.fs.renameMu.Lock() d.checkDropLocked(ctx) @@ -546,7 +552,9 @@ func (d *dentry) DecRef(ctx context.Context) { func (d *dentry) decRefLocked(ctx context.Context) { r := atomic.AddInt64(&d.refs, -1) - refsvfs2.LogDecRef(d, r) + if d.LogRefs() { + refsvfs2.LogDecRef(d, r) + } if r == 0 { d.checkDropLocked(ctx) } else if r < 0 { -- cgit v1.2.3