Implement file locks for regular tmpfs files in VFSv2.

Add a file lock implementation that can be embedded into various filesystem
implementations.

Updates #1480

PiperOrigin-RevId: 292614758

1 files changed, 23 insertions, 0 deletions

diff --git a/pkg/sentry/fsimpl/tmpfs/regular_file.go b/pkg/sentry/fsimpl/tmpfs/regular_file.go
index e9e6faf67..dab346a41 100644
--- a/pkg/sentry/fsimpl/tmpfs/regular_file.go
+++ b/pkg/sentry/fsimpl/tmpfs/regular_file.go
@@ -23,6 +23,7 @@ import (
 	"gvisor.dev/gvisor/pkg/context"
 	"gvisor.dev/gvisor/pkg/safemem"
 	"gvisor.dev/gvisor/pkg/sentry/fs/fsutil"
+	"gvisor.dev/gvisor/pkg/sentry/fs/lock"
 	"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
 	"gvisor.dev/gvisor/pkg/sentry/memmap"
 	"gvisor.dev/gvisor/pkg/sentry/pgalloc"
@@ -192,6 +193,28 @@ func (fd *regularFileFD) Sync(ctx context.Context) error {
 	return nil
 }
 
+// LockBSD implements vfs.FileDescriptionImpl.LockBSD.
+func (fd *regularFileFD) LockBSD(ctx context.Context, uid lock.UniqueID, t lock.LockType, block lock.Blocker) error {
+	return fd.inode().lockBSD(uid, t, block)
+}
+
+// UnlockBSD implements vfs.FileDescriptionImpl.UnlockBSD.
+func (fd *regularFileFD) UnlockBSD(ctx context.Context, uid lock.UniqueID) error {
+	fd.inode().unlockBSD(uid)
+	return nil
+}
+
+// LockPOSIX implements vfs.FileDescriptionImpl.LockPOSIX.
+func (fd *regularFileFD) LockPOSIX(ctx context.Context, uid lock.UniqueID, t lock.LockType, rng lock.LockRange, block lock.Blocker) error {
+	return fd.inode().lockPOSIX(uid, t, rng, block)
+}
+
+// UnlockPOSIX implements vfs.FileDescriptionImpl.UnlockPOSIX.
+func (fd *regularFileFD) UnlockPOSIX(ctx context.Context, uid lock.UniqueID, rng lock.LockRange) error {
+	fd.inode().unlockPOSIX(uid, rng)
+	return nil
+}
+
 // regularFileReadWriter implements safemem.Reader and Safemem.Writer.
 type regularFileReadWriter struct {
 	file *regularFile