diff options
| -rw-r--r-- | pkg/refs_vfs2/refs_template.go | 2 | ||||
| -rw-r--r-- | pkg/sentry/fsimpl/tmpfs/BUILD | 13 | ||||
| -rw-r--r-- | pkg/sentry/fsimpl/tmpfs/tmpfs.go | 27 |
3 files changed, 20 insertions, 22 deletions
diff --git a/pkg/refs_vfs2/refs_template.go b/pkg/refs_vfs2/refs_template.go index 3e5b458c7..99c43c065 100644 --- a/pkg/refs_vfs2/refs_template.go +++ b/pkg/refs_vfs2/refs_template.go @@ -59,7 +59,7 @@ func (r *Refs) finalize() { note = "(Leak checker uninitialized): " } if n := r.ReadRefs(); n != 0 { - log.Warningf("%sAtomicRefCount %p owned by %T garbage collected with ref count of %d (want 0)", note, r, ownerType, n) + log.Warningf("%sRefs %p owned by %T garbage collected with ref count of %d (want 0)", note, r, ownerType, n) } } diff --git a/pkg/sentry/fsimpl/tmpfs/BUILD b/pkg/sentry/fsimpl/tmpfs/BUILD index e73732a6b..5cd428d64 100644 --- a/pkg/sentry/fsimpl/tmpfs/BUILD +++ b/pkg/sentry/fsimpl/tmpfs/BUILD @@ -26,6 +26,17 @@ go_template_instance( }, ) +go_template_instance( + name = "inode_refs", + out = "inode_refs.go", + package = "tmpfs", + prefix = "inode", + template = "//pkg/refs_vfs2:refs_template", + types = { + "T": "inode", + }, +) + go_library( name = "tmpfs", srcs = [ @@ -34,6 +45,7 @@ go_library( "directory.go", "filesystem.go", "fstree.go", + "inode_refs.go", "named_pipe.go", "regular_file.go", "socket_file.go", @@ -47,6 +59,7 @@ go_library( "//pkg/context", "//pkg/fspath", "//pkg/log", + "//pkg/refs", "//pkg/safemem", "//pkg/sentry/arch", "//pkg/sentry/fs", diff --git a/pkg/sentry/fsimpl/tmpfs/tmpfs.go b/pkg/sentry/fsimpl/tmpfs/tmpfs.go index 4681a2f52..de2af6d01 100644 --- a/pkg/sentry/fsimpl/tmpfs/tmpfs.go +++ b/pkg/sentry/fsimpl/tmpfs/tmpfs.go @@ -285,13 +285,10 @@ type inode struct { // fs is the owning filesystem. fs is immutable. fs *filesystem - // refs is a reference count. refs is accessed using atomic memory - // operations. - // // A reference is held on all inodes as long as they are reachable in the // filesystem tree, i.e. nlink is nonzero. This reference is dropped when // nlink reaches 0. - refs int64 + refs inodeRefs // xattrs implements extended attributes. // @@ -327,7 +324,6 @@ func (i *inode) init(impl interface{}, fs *filesystem, kuid auth.KUID, kgid auth panic("file type is required in FileMode") } i.fs = fs - i.refs = 1 i.mode = uint32(mode) i.uid = uint32(kuid) i.gid = uint32(kgid) @@ -339,6 +335,7 @@ func (i *inode) init(impl interface{}, fs *filesystem, kuid auth.KUID, kgid auth i.mtime = now // i.nlink initialized by caller i.impl = impl + i.refs.EnableLeakCheck() } // incLinksLocked increments i's link count. @@ -369,25 +366,15 @@ func (i *inode) decLinksLocked(ctx context.Context) { } func (i *inode) incRef() { - if atomic.AddInt64(&i.refs, 1) <= 1 { - panic("tmpfs.inode.incRef() called without holding a reference") - } + i.refs.IncRef() } func (i *inode) tryIncRef() bool { - for { - refs := atomic.LoadInt64(&i.refs) - if refs == 0 { - return false - } - if atomic.CompareAndSwapInt64(&i.refs, refs, refs+1) { - return true - } - } + return i.refs.TryIncRef() } func (i *inode) decRef(ctx context.Context) { - if refs := atomic.AddInt64(&i.refs, -1); refs == 0 { + i.refs.DecRef(func() { i.watches.HandleDeletion(ctx) if regFile, ok := i.impl.(*regularFile); ok { // Release memory used by regFile to store data. Since regFile is @@ -395,9 +382,7 @@ func (i *inode) decRef(ctx context.Context) { // metadata. regFile.data.DropAll(regFile.memFile) } - } else if refs < 0 { - panic("tmpfs.inode.decRef() called without holding a reference") - } + }) } func (i *inode) checkPermissions(creds *auth.Credentials, ats vfs.AccessTypes) error { |