From ccf69bdd7e05a4e5f404fbef89a7f49f218645e2 Mon Sep 17 00:00:00 2001 From: Dean Deng Date: Fri, 29 May 2020 12:27:15 -0700 Subject: Implement IN_EXCL_UNLINK inotify option in vfs2. Limited to tmpfs. Inotify support in other filesystem implementations to follow. Updates #1479 PiperOrigin-RevId: 313828648 --- pkg/sentry/fsimpl/tmpfs/directory.go | 3 ++- pkg/sentry/fsimpl/tmpfs/filesystem.go | 14 +++++++------- pkg/sentry/fsimpl/tmpfs/tmpfs.go | 18 +++++++++++------- 3 files changed, 20 insertions(+), 15 deletions(-) (limited to 'pkg/sentry/fsimpl/tmpfs') diff --git a/pkg/sentry/fsimpl/tmpfs/directory.go b/pkg/sentry/fsimpl/tmpfs/directory.go index 8bc475f88..70387cb9c 100644 --- a/pkg/sentry/fsimpl/tmpfs/directory.go +++ b/pkg/sentry/fsimpl/tmpfs/directory.go @@ -79,6 +79,7 @@ func (dir *directory) removeChildLocked(child *dentry) { dir.iterMu.Lock() dir.childList.Remove(child) dir.iterMu.Unlock() + child.unlinked = true } type directoryFD struct { @@ -112,7 +113,7 @@ func (fd *directoryFD) IterDirents(ctx context.Context, cb vfs.IterDirentsCallba dir.iterMu.Lock() defer dir.iterMu.Unlock() - fd.dentry().InotifyWithParent(linux.IN_ACCESS, 0) + fd.dentry().InotifyWithParent(linux.IN_ACCESS, 0, vfs.PathEvent) fd.inode().touchAtime(fd.vfsfd.Mount()) if fd.off == 0 { diff --git a/pkg/sentry/fsimpl/tmpfs/filesystem.go b/pkg/sentry/fsimpl/tmpfs/filesystem.go index b4159f904..183eb975c 100644 --- a/pkg/sentry/fsimpl/tmpfs/filesystem.go +++ b/pkg/sentry/fsimpl/tmpfs/filesystem.go @@ -182,7 +182,7 @@ func (fs *filesystem) doCreateAt(rp *vfs.ResolvingPath, dir bool, create func(pa if dir { ev |= linux.IN_ISDIR } - parentDir.inode.watches.Notify(name, uint32(ev), 0) + parentDir.inode.watches.Notify(name, uint32(ev), 0, vfs.InodeEvent) parentDir.inode.touchCMtime() return nil } @@ -247,7 +247,7 @@ func (fs *filesystem) LinkAt(ctx context.Context, rp *vfs.ResolvingPath, vd vfs. return syserror.EMLINK } d.inode.incLinksLocked() - d.inode.watches.Notify("", linux.IN_ATTRIB, 0) + d.inode.watches.Notify("", linux.IN_ATTRIB, 0, vfs.InodeEvent) parentDir.insertChildLocked(fs.newDentry(d.inode), name) return nil }) @@ -361,7 +361,7 @@ afterTrailingSymlink: if err != nil { return nil, err } - parentDir.inode.watches.Notify(name, linux.IN_CREATE, 0) + parentDir.inode.watches.Notify(name, linux.IN_CREATE, 0, vfs.PathEvent) parentDir.inode.touchCMtime() return fd, nil } @@ -613,7 +613,7 @@ func (fs *filesystem) RmdirAt(ctx context.Context, rp *vfs.ResolvingPath) error return err } parentDir.removeChildLocked(child) - parentDir.inode.watches.Notify(name, linux.IN_DELETE|linux.IN_ISDIR, 0) + parentDir.inode.watches.Notify(name, linux.IN_DELETE|linux.IN_ISDIR, 0, vfs.InodeEvent) // Remove links for child, child/., and child/.. child.inode.decLinksLocked() child.inode.decLinksLocked() @@ -636,7 +636,7 @@ func (fs *filesystem) SetStatAt(ctx context.Context, rp *vfs.ResolvingPath, opts } if ev := vfs.InotifyEventFromStatMask(opts.Stat.Mask); ev != 0 { - d.InotifyWithParent(ev, 0) + d.InotifyWithParent(ev, 0, vfs.InodeEvent) } return nil } @@ -784,7 +784,7 @@ func (fs *filesystem) SetxattrAt(ctx context.Context, rp *vfs.ResolvingPath, opt return err } - d.InotifyWithParent(linux.IN_ATTRIB, 0) + d.InotifyWithParent(linux.IN_ATTRIB, 0, vfs.InodeEvent) return nil } @@ -800,7 +800,7 @@ func (fs *filesystem) RemovexattrAt(ctx context.Context, rp *vfs.ResolvingPath, return err } - d.InotifyWithParent(linux.IN_ATTRIB, 0) + d.InotifyWithParent(linux.IN_ATTRIB, 0, vfs.InodeEvent) return nil } diff --git a/pkg/sentry/fsimpl/tmpfs/tmpfs.go b/pkg/sentry/fsimpl/tmpfs/tmpfs.go index 1d83b6840..f0e098702 100644 --- a/pkg/sentry/fsimpl/tmpfs/tmpfs.go +++ b/pkg/sentry/fsimpl/tmpfs/tmpfs.go @@ -163,6 +163,11 @@ type dentry struct { // filesystem.mu. name string + // unlinked indicates whether this dentry has been unlinked from its parent. + // It is only set to true on an unlink operation, and never set from true to + // false. unlinked is protected by filesystem.mu. + unlinked bool + // dentryEntry (ugh) links dentries into their parent directory.childList. dentryEntry @@ -202,7 +207,7 @@ func (d *dentry) DecRef() { } // InotifyWithParent implements vfs.DentryImpl.InotifyWithParent. -func (d *dentry) InotifyWithParent(events uint32, cookie uint32) { +func (d *dentry) InotifyWithParent(events uint32, cookie uint32, et vfs.EventType) { if d.inode.isDir() { events |= linux.IN_ISDIR } @@ -211,9 +216,9 @@ func (d *dentry) InotifyWithParent(events uint32, cookie uint32) { if d.parent != nil { // Note that d.parent or d.name may be stale if there is a concurrent // rename operation. Inotify does not provide consistency guarantees. - d.parent.inode.watches.Notify(d.name, events, cookie) + d.parent.inode.watches.NotifyWithExclusions(d.name, events, cookie, et, d.unlinked) } - d.inode.watches.Notify("", events, cookie) + d.inode.watches.Notify("", events, cookie, et) } // Watches implements vfs.DentryImpl.Watches. @@ -676,9 +681,8 @@ func (fd *fileDescription) SetStat(ctx context.Context, opts vfs.SetStatOptions) return err } - // Generate inotify events. if ev := vfs.InotifyEventFromStatMask(opts.Stat.Mask); ev != 0 { - d.InotifyWithParent(ev, 0) + d.InotifyWithParent(ev, 0, vfs.InodeEvent) } return nil } @@ -701,7 +705,7 @@ func (fd *fileDescription) Setxattr(ctx context.Context, opts vfs.SetxattrOption } // Generate inotify events. - d.InotifyWithParent(linux.IN_ATTRIB, 0) + d.InotifyWithParent(linux.IN_ATTRIB, 0, vfs.InodeEvent) return nil } @@ -713,7 +717,7 @@ func (fd *fileDescription) Removexattr(ctx context.Context, name string) error { } // Generate inotify events. - d.InotifyWithParent(linux.IN_ATTRIB, 0) + d.InotifyWithParent(linux.IN_ATTRIB, 0, vfs.InodeEvent) return nil } -- cgit v1.2.3