diff options
Diffstat (limited to 'pkg/sentry/vfs/inotify.go')
| -rw-r--r-- | pkg/sentry/vfs/inotify.go | 38 |
1 files changed, 30 insertions, 8 deletions
diff --git a/pkg/sentry/vfs/inotify.go b/pkg/sentry/vfs/inotify.go index 1d28ccb46..05a3051a4 100644 --- a/pkg/sentry/vfs/inotify.go +++ b/pkg/sentry/vfs/inotify.go @@ -33,6 +33,19 @@ import ( // must be a power 2 for rounding below. const inotifyEventBaseSize = 16 +// EventType defines different kinds of inotfiy events. +// +// The way events are labelled appears somewhat arbitrary, but they must match +// Linux so that IN_EXCL_UNLINK behaves as it does in Linux. +type EventType uint8 + +// PathEvent and InodeEvent correspond to FSNOTIFY_EVENT_PATH and +// FSNOTIFY_EVENT_INODE in Linux. +const ( + PathEvent EventType = iota + InodeEvent EventType = iota +) + // Inotify represents an inotify instance created by inotify_init(2) or // inotify_init1(2). Inotify implements FileDescriptionImpl. // @@ -419,13 +432,22 @@ func (w *Watches) Remove(id uint64) { } // Notify queues a new event with all watches in this set. -func (w *Watches) Notify(name string, events, cookie uint32) { +func (w *Watches) Notify(name string, events, cookie uint32, et EventType) { + w.NotifyWithExclusions(name, events, cookie, et, false) +} + +// NotifyWithExclusions queues a new event with watches in this set. Watches +// with IN_EXCL_UNLINK are skipped if the event is coming from a child that +// has been unlinked. +func (w *Watches) NotifyWithExclusions(name string, events, cookie uint32, et EventType, unlinked bool) { // N.B. We don't defer the unlocks because Notify is in the hot path of // all IO operations, and the defer costs too much for small IO // operations. w.mu.RLock() for _, watch := range w.ws { - // TODO(gvisor.dev/issue/1479): Skip for IN_EXCL_UNLINK cases. + if unlinked && watch.ExcludeUnlinkedChildren() && et == PathEvent { + continue + } watch.Notify(name, events, cookie) } w.mu.RUnlock() @@ -434,7 +456,7 @@ func (w *Watches) Notify(name string, events, cookie uint32) { // HandleDeletion is called when the watch target is destroyed to emit // the appropriate events. func (w *Watches) HandleDeletion() { - w.Notify("", linux.IN_DELETE_SELF, 0) + w.Notify("", linux.IN_DELETE_SELF, 0, InodeEvent) // TODO(gvisor.dev/issue/1479): This doesn't work because maps are not copied // by value. Ideally, we wouldn't have this circular locking so we can just @@ -655,8 +677,8 @@ func InotifyEventFromStatMask(mask uint32) uint32 { // InotifyRemoveChild sends the appriopriate notifications to the watch sets of // the child being removed and its parent. func InotifyRemoveChild(self, parent *Watches, name string) { - self.Notify("", linux.IN_ATTRIB, 0) - parent.Notify(name, linux.IN_DELETE, 0) + self.Notify("", linux.IN_ATTRIB, 0, InodeEvent) + parent.Notify(name, linux.IN_DELETE, 0, InodeEvent) // TODO(gvisor.dev/issue/1479): implement IN_EXCL_UNLINK. } @@ -668,8 +690,8 @@ func InotifyRename(ctx context.Context, renamed, oldParent, newParent *Watches, dirEv = linux.IN_ISDIR } cookie := uniqueid.InotifyCookie(ctx) - oldParent.Notify(oldName, dirEv|linux.IN_MOVED_FROM, cookie) - newParent.Notify(newName, dirEv|linux.IN_MOVED_TO, cookie) + oldParent.Notify(oldName, dirEv|linux.IN_MOVED_FROM, cookie, InodeEvent) + newParent.Notify(newName, dirEv|linux.IN_MOVED_TO, cookie, InodeEvent) // Somewhat surprisingly, self move events do not have a cookie. - renamed.Notify("", linux.IN_MOVE_SELF, 0) + renamed.Notify("", linux.IN_MOVE_SELF, 0, InodeEvent) } |