Implement F_GETLK fcntl.

Fixes #5113.

PiperOrigin-RevId: 353313374

1 files changed, 14 insertions, 6 deletions

diff --git a/pkg/sentry/vfs/file_description.go b/pkg/sentry/vfs/file_description.go
index dbf8425b4..eb6c2e36b 100644
--- a/pkg/sentry/vfs/file_description.go
+++ b/pkg/sentry/vfs/file_description.go
@@ -448,16 +448,19 @@ type FileDescriptionImpl interface {
 	RemoveXattr(ctx context.Context, name string) error
 
 	// LockBSD tries to acquire a BSD-style advisory file lock.
-	LockBSD(ctx context.Context, uid lock.UniqueID, t lock.LockType, block lock.Blocker) error
+	LockBSD(ctx context.Context, uid lock.UniqueID, ownerPID int32, t lock.LockType, block lock.Blocker) error
 
 	// UnlockBSD releases a BSD-style advisory file lock.
 	UnlockBSD(ctx context.Context, uid lock.UniqueID) error
 
 	// LockPOSIX tries to acquire a POSIX-style advisory file lock.
-	LockPOSIX(ctx context.Context, uid lock.UniqueID, t lock.LockType, r lock.LockRange, block lock.Blocker) error
+	LockPOSIX(ctx context.Context, uid lock.UniqueID, ownerPID int32, t lock.LockType, r lock.LockRange, block lock.Blocker) error
 
 	// UnlockPOSIX releases a POSIX-style advisory file lock.
 	UnlockPOSIX(ctx context.Context, uid lock.UniqueID, ComputeLockRange lock.LockRange) error
+
+	// TestPOSIX returns information about whether the specified lock can be held, in the style of the F_GETLK fcntl.
+	TestPOSIX(ctx context.Context, uid lock.UniqueID, t lock.LockType, r lock.LockRange) (linux.Flock, error)
 }
 
 // Dirent holds the information contained in struct linux_dirent64.
@@ -791,9 +794,9 @@ func (fd *FileDescription) Msync(ctx context.Context, mr memmap.MappableRange) e
 }
 
 // LockBSD tries to acquire a BSD-style advisory file lock.
-func (fd *FileDescription) LockBSD(ctx context.Context, lockType lock.LockType, blocker lock.Blocker) error {
+func (fd *FileDescription) LockBSD(ctx context.Context, ownerPID int32, lockType lock.LockType, blocker lock.Blocker) error {
 	atomic.StoreUint32(&fd.usedLockBSD, 1)
-	return fd.impl.LockBSD(ctx, fd, lockType, blocker)
+	return fd.impl.LockBSD(ctx, fd, ownerPID, lockType, blocker)
 }
 
 // UnlockBSD releases a BSD-style advisory file lock.
@@ -802,8 +805,8 @@ func (fd *FileDescription) UnlockBSD(ctx context.Context) error {
 }
 
 // LockPOSIX locks a POSIX-style file range lock.
-func (fd *FileDescription) LockPOSIX(ctx context.Context, uid lock.UniqueID, t lock.LockType, r lock.LockRange, block lock.Blocker) error {
-	return fd.impl.LockPOSIX(ctx, uid, t, r, block)
+func (fd *FileDescription) LockPOSIX(ctx context.Context, uid lock.UniqueID, ownerPID int32, t lock.LockType, r lock.LockRange, block lock.Blocker) error {
+	return fd.impl.LockPOSIX(ctx, uid, ownerPID, t, r, block)
 }
 
 // UnlockPOSIX unlocks a POSIX-style file range lock.
@@ -811,6 +814,11 @@ func (fd *FileDescription) UnlockPOSIX(ctx context.Context, uid lock.UniqueID, r
 	return fd.impl.UnlockPOSIX(ctx, uid, r)
 }
 
+// TestPOSIX returns information about whether the specified lock can be held.
+func (fd *FileDescription) TestPOSIX(ctx context.Context, uid lock.UniqueID, t lock.LockType, r lock.LockRange) (linux.Flock, error) {
+	return fd.impl.TestPOSIX(ctx, uid, t, r)
+}
+
 // ComputeLockRange computes the range of a file lock based on the given values.
 func (fd *FileDescription) ComputeLockRange(ctx context.Context, start uint64, length uint64, whence int16) (lock.LockRange, error) {
 	var off int64