diff options
Diffstat (limited to 'pkg/sentry/fsimpl/overlay/filesystem.go')
| -rw-r--r-- | pkg/sentry/fsimpl/overlay/filesystem.go | 24 |
1 files changed, 17 insertions, 7 deletions
diff --git a/pkg/sentry/fsimpl/overlay/filesystem.go b/pkg/sentry/fsimpl/overlay/filesystem.go index bc07d72c0..d55bdc97f 100644 --- a/pkg/sentry/fsimpl/overlay/filesystem.go +++ b/pkg/sentry/fsimpl/overlay/filesystem.go @@ -78,26 +78,36 @@ func putDentrySlice(ds *[]*dentry) { } // renameMuRUnlockAndCheckDrop calls fs.renameMu.RUnlock(), then calls -// dentry.checkDropLocked on all dentries in *ds with fs.renameMu locked for +// dentry.checkDropLocked on all dentries in *dsp with fs.renameMu locked for // writing. // -// ds is a pointer-to-pointer since defer evaluates its arguments immediately, +// dsp is a pointer-to-pointer since defer evaluates its arguments immediately, // but dentry slices are allocated lazily, and it's much easier to say "defer // fs.renameMuRUnlockAndCheckDrop(&ds)" than "defer func() { // fs.renameMuRUnlockAndCheckDrop(ds) }()" to work around this. -func (fs *filesystem) renameMuRUnlockAndCheckDrop(ctx context.Context, ds **[]*dentry) { +func (fs *filesystem) renameMuRUnlockAndCheckDrop(ctx context.Context, dsp **[]*dentry) { fs.renameMu.RUnlock() - if *ds == nil { + if *dsp == nil { return } - if len(**ds) != 0 { + ds := **dsp + // Only go through calling dentry.checkDropLocked() (which requires + // re-locking renameMu) if we actually have any dentries with zero refs. + checkAny := false + for i := range ds { + if atomic.LoadInt64(&ds[i].refs) == 0 { + checkAny = true + break + } + } + if checkAny { fs.renameMu.Lock() - for _, d := range **ds { + for _, d := range ds { d.checkDropLocked(ctx) } fs.renameMu.Unlock() } - putDentrySlice(*ds) + putDentrySlice(*dsp) } func (fs *filesystem) renameMuUnlockAndCheckDrop(ctx context.Context, ds **[]*dentry) { |