From 0c292cdaab5c226bcf90c3376a0f3942cb266eed Mon Sep 17 00:00:00 2001 From: Nicolas Lacasse Date: Tue, 4 Jun 2019 12:57:41 -0700 Subject: Remove the Dirent field from Pipe. Dirents are ref-counted, but Pipes are not. Holding a Dirent inside of a Pipe raises difficult questions about the lifecycle of the Pipe and Dirent. Fortunately, we can side-step those questions by removing the Dirent field from Pipe entirely. We only need the Dirent when constructing fs.Files (which are ref-counted), and in GetFile (when a Dirent is passed to us anyways). PiperOrigin-RevId: 251497628 --- pkg/sentry/kernel/pipe/node.go | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) (limited to 'pkg/sentry/kernel/pipe/node.go') diff --git a/pkg/sentry/kernel/pipe/node.go b/pkg/sentry/kernel/pipe/node.go index 926c4c623..dc7da529e 100644 --- a/pkg/sentry/kernel/pipe/node.go +++ b/pkg/sentry/kernel/pipe/node.go @@ -38,7 +38,11 @@ type inodeOperations struct { fsutil.InodeNotMappable `state:"nosave"` fsutil.InodeNotSocket `state:"nosave"` fsutil.InodeNotSymlink `state:"nosave"` - fsutil.InodeNotVirtual `state:"nosave"` + + // Marking pipe inodes as virtual allows them to be saved and restored + // even if they have been unlinked. We can get away with this because + // their state exists entirely within the sentry. + fsutil.InodeVirtual `state:"nosave"` fsutil.InodeSimpleAttributes @@ -86,7 +90,7 @@ func (i *inodeOperations) GetFile(ctx context.Context, d *fs.Dirent, flags fs.Fi switch { case flags.Read && !flags.Write: // O_RDONLY. - r := i.p.Open(ctx, flags) + r := i.p.Open(ctx, d, flags) i.newHandleLocked(&i.rWakeup) if i.p.isNamed && !flags.NonBlocking && !i.p.HasWriters() { @@ -102,7 +106,7 @@ func (i *inodeOperations) GetFile(ctx context.Context, d *fs.Dirent, flags fs.Fi return r, nil case flags.Write && !flags.Read: // O_WRONLY. - w := i.p.Open(ctx, flags) + w := i.p.Open(ctx, d, flags) i.newHandleLocked(&i.wWakeup) if i.p.isNamed && !i.p.HasReaders() { @@ -122,7 +126,7 @@ func (i *inodeOperations) GetFile(ctx context.Context, d *fs.Dirent, flags fs.Fi case flags.Read && flags.Write: // O_RDWR. // Pipes opened for read-write always succeeds without blocking. - rw := i.p.Open(ctx, flags) + rw := i.p.Open(ctx, d, flags) i.newHandleLocked(&i.rWakeup) i.newHandleLocked(&i.wWakeup) return rw, nil -- cgit v1.2.3