Implement POSIX locks

- Change FileDescriptionImpl Lock/UnlockPOSIX signature to
  take {start,length,whence}, so the correct offset can be
  calculated in the implementations.
- Create PosixLocker interface to make it possible to share
  the same locking code from different implementations.

Closes #1480

PiperOrigin-RevId: 316910286

1 files changed, 12 insertions, 2 deletions

diff --git a/pkg/sentry/fsimpl/devpts/slave.go b/pkg/sentry/fsimpl/devpts/slave.go
index 7fe475080..cf1a0f0ac 100644
--- a/pkg/sentry/fsimpl/devpts/slave.go
+++ b/pkg/sentry/fsimpl/devpts/slave.go
@@ -18,10 +18,10 @@ import (
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/context"
 	"gvisor.dev/gvisor/pkg/sentry/arch"
+	fslock "gvisor.dev/gvisor/pkg/sentry/fs/lock"
 	"gvisor.dev/gvisor/pkg/sentry/fsimpl/kernfs"
 	"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
 	"gvisor.dev/gvisor/pkg/sentry/vfs"
-	"gvisor.dev/gvisor/pkg/sentry/vfs/lock"
 	"gvisor.dev/gvisor/pkg/syserror"
 	"gvisor.dev/gvisor/pkg/usermem"
 	"gvisor.dev/gvisor/pkg/waiter"
@@ -34,7 +34,7 @@ type slaveInode struct {
 	kernfs.InodeNotDirectory
 	kernfs.InodeNotSymlink
 
-	locks lock.FileLocks
+	locks vfs.FileLocks
 
 	// Keep a reference to this inode's dentry.
 	dentry kernfs.Dentry
@@ -185,3 +185,13 @@ func (sfd *slaveFileDescription) Stat(ctx context.Context, opts vfs.StatOptions)
 	fs := sfd.vfsfd.VirtualDentry().Mount().Filesystem()
 	return sfd.inode.Stat(fs, opts)
 }
+
+// LockPOSIX implements vfs.FileDescriptionImpl.LockPOSIX.
+func (sfd *slaveFileDescription) LockPOSIX(ctx context.Context, uid fslock.UniqueID, t fslock.LockType, start, length uint64, whence int16, block fslock.Blocker) error {
+	return sfd.Locks().LockPOSIX(ctx, &sfd.vfsfd, uid, t, start, length, whence, block)
+}
+
+// UnlockPOSIX implements vfs.FileDescriptionImpl.UnlockPOSIX.
+func (sfd *slaveFileDescription) UnlockPOSIX(ctx context.Context, uid fslock.UniqueID, start, length uint64, whence int16) error {
+	return sfd.Locks().UnlockPOSIX(ctx, &sfd.vfsfd, uid, start, length, whence)
+}