Implement flock(2) in VFS2

LockFD is the generic implementation that can be embedded in
FileDescriptionImpl implementations. Unique lock ID is
maintained in vfs.FileDescription and is created on demand.

Updates #1480

PiperOrigin-RevId: 315604825

65 files changed, 406 insertions, 267 deletions

diff --git a/pkg/sentry/devices/memdev/full.go b/pkg/sentry/devices/memdev/full.go
index c7e197691..af66fe4dc 100644
--- a/pkg/sentry/devices/memdev/full.go
+++ b/pkg/sentry/devices/memdev/full.go
@@ -42,6 +42,7 @@ type fullFD struct {
 	vfsfd vfs.FileDescription
 	vfs.FileDescriptionDefaultImpl
 	vfs.DentryMetadataFileDescriptionImpl
+	vfs.NoLockFD
 }
 
 // Release implements vfs.FileDescriptionImpl.Release.
diff --git a/pkg/sentry/devices/memdev/null.go b/pkg/sentry/devices/memdev/null.go
index 33d060d02..92d3d71be 100644
--- a/pkg/sentry/devices/memdev/null.go
+++ b/pkg/sentry/devices/memdev/null.go
@@ -43,6 +43,7 @@ type nullFD struct {
 	vfsfd vfs.FileDescription
 	vfs.FileDescriptionDefaultImpl
 	vfs.DentryMetadataFileDescriptionImpl
+	vfs.NoLockFD
 }
 
 // Release implements vfs.FileDescriptionImpl.Release.
diff --git a/pkg/sentry/devices/memdev/random.go b/pkg/sentry/devices/memdev/random.go
index acfa23149..6b81da5ef 100644
--- a/pkg/sentry/devices/memdev/random.go
+++ b/pkg/sentry/devices/memdev/random.go
@@ -48,6 +48,7 @@ type randomFD struct {
 	vfsfd vfs.FileDescription
 	vfs.FileDescriptionDefaultImpl
 	vfs.DentryMetadataFileDescriptionImpl
+	vfs.NoLockFD
 
 	// off is the "file offset". off is accessed using atomic memory
 	// operations.
diff --git a/pkg/sentry/devices/memdev/zero.go b/pkg/sentry/devices/memdev/zero.go
index 3b1372b9e..c6f15054d 100644
--- a/pkg/sentry/devices/memdev/zero.go
+++ b/pkg/sentry/devices/memdev/zero.go
@@ -44,6 +44,7 @@ type zeroFD struct {
 	vfsfd vfs.FileDescription
 	vfs.FileDescriptionDefaultImpl
 	vfs.DentryMetadataFileDescriptionImpl
+	vfs.NoLockFD
 }
 
 // Release implements vfs.FileDescriptionImpl.Release.
diff --git a/pkg/sentry/fs/file.go b/pkg/sentry/fs/file.go
index 2a278fbe3..ca41520b4 100644
--- a/pkg/sentry/fs/file.go
+++ b/pkg/sentry/fs/file.go
@@ -146,7 +146,7 @@ func (f *File) DecRef() {
 	f.DecRefWithDestructor(func() {
 		// Drop BSD style locks.
 		lockRng := lock.LockRange{Start: 0, End: lock.LockEOF}
-		f.Dirent.Inode.LockCtx.BSD.UnlockRegion(lock.UniqueID(f.UniqueID), lockRng)
+		f.Dirent.Inode.LockCtx.BSD.UnlockRegion(f, lockRng)
 
 		// Release resources held by the FileOperations.
 		f.FileOperations.Release()
diff --git a/pkg/sentry/fs/lock/lock.go b/pkg/sentry/fs/lock/lock.go
index 926538d90..8a5d9c7eb 100644
--- a/pkg/sentry/fs/lock/lock.go
+++ b/pkg/sentry/fs/lock/lock.go
@@ -62,7 +62,7 @@ import (
 type LockType int
 
 // UniqueID is a unique identifier of the holder of a regional file lock.
-type UniqueID uint64
+type UniqueID interface{}
 
 const (
 	// ReadLock describes a POSIX regional file lock to be taken
@@ -98,12 +98,7 @@ type Lock struct {
 	// If len(Readers) > 0 then HasWriter must be false.
 	Readers map[UniqueID]bool
 
-	// HasWriter indicates that this is a write lock held by a single
-	// UniqueID.
-	HasWriter bool
-
-	// Writer is only valid if HasWriter is true.  It identifies a
-	// single write lock holder.
+	// Writer holds the writer unique ID. It's nil if there are no writers.
 	Writer UniqueID
 }
 
@@ -186,7 +181,6 @@ func makeLock(uid UniqueID, t LockType) Lock {
 	case ReadLock:
 		value.Readers[uid] = true
 	case WriteLock:
-		value.HasWriter = true
 		value.Writer = uid
 	default:
 		panic(fmt.Sprintf("makeLock: invalid lock type %d", t))
@@ -196,10 +190,7 @@ func makeLock(uid UniqueID, t LockType) Lock {
 
 // isHeld returns true if uid is a holder of Lock.
 func (l Lock) isHeld(uid UniqueID) bool {
-	if l.HasWriter && l.Writer == uid {
-		return true
-	}
-	return l.Readers[uid]
+	return l.Writer == uid || l.Readers[uid]
 }
 
 // lock sets uid as a holder of a typed lock on Lock.
@@ -214,20 +205,20 @@ func (l *Lock) lock(uid UniqueID, t LockType) {
 		}
 		// We cannot downgrade a write lock to a read lock unless the
 		// uid is the same.
-		if l.HasWriter {
+		if l.Writer != nil {
 			if l.Writer != uid {
 				panic(fmt.Sprintf("lock: cannot downgrade write lock to read lock for uid %d, writer is %d", uid, l.Writer))
 			}
 			// Ensure that there is only one reader if upgrading.
 			l.Readers = make(map[UniqueID]bool)
 			// Ensure that there is no longer a writer.
-			l.HasWriter = false
+			l.Writer = nil
 		}
 		l.Readers[uid] = true
 		return
 	case WriteLock:
 		// If we are already the writer, then this is a no-op.
-		if l.HasWriter && l.Writer == uid {
+		if l.Writer == uid {
 			return
 		}
 		// We can only upgrade a read lock to a write lock if there
@@ -243,7 +234,6 @@ func (l *Lock) lock(uid UniqueID, t LockType) {
 		}
 		// Ensure that there is only a writer.
 		l.Readers = make(map[UniqueID]bool)
-		l.HasWriter = true
 		l.Writer = uid
 	default:
 		panic(fmt.Sprintf("lock: invalid lock type %d", t))
@@ -277,9 +267,8 @@ func (l LockSet) canLock(uid UniqueID, t LockType, r LockRange) bool {
 	switch t {
 	case ReadLock:
 		return l.lockable(r, func(value Lock) bool {
-			// If there is no writer, there's no problem adding
-			// another reader.
-			if !value.HasWriter {
+			// If there is no writer, there's no problem adding another reader.
+			if value.Writer == nil {
 				return true
 			}
 			// If there is a writer, then it must be the same uid
@@ -289,10 +278,9 @@ func (l LockSet) canLock(uid UniqueID, t LockType, r LockRange) bool {
 	case WriteLock:
 		return l.lockable(r, func(value Lock) bool {
 			// If there are only readers.
-			if !value.HasWriter {
-				// Then this uid can only take a write lock if
-				// this is a private upgrade, meaning that the
-				// only reader is uid.
+			if value.Writer == nil {
+				// Then this uid can only take a write lock if this is a private
+				// upgrade, meaning that the only reader is uid.
 				return len(value.Readers) == 1 && value.Readers[uid]
 			}
 			// If the uid is already a writer on this region, then
@@ -304,7 +292,8 @@ func (l LockSet) canLock(uid UniqueID, t LockType, r LockRange) bool {
 	}
 }
 
-// lock returns true if uid took a lock of type t on the entire range of LockRange.
+// lock returns true if uid took a lock of type t on the entire range of
+// LockRange.
 //
 // Preconditions: r.Start <= r.End (will panic otherwise).
 func (l *LockSet) lock(uid UniqueID, t LockType, r LockRange) bool {
@@ -339,7 +328,7 @@ func (l *LockSet) lock(uid UniqueID, t LockType, r LockRange) bool {
 			seg, _ = l.SplitUnchecked(seg, r.End)
 		}
 
-		// Set the lock on the segment.  This is guaranteed to
+		// Set the lock on the segment. This is guaranteed to
 		// always be safe, given canLock above.
 		value := seg.ValuePtr()
 		value.lock(uid, t)
@@ -386,7 +375,7 @@ func (l *LockSet) unlock(uid UniqueID, r LockRange) {
 
 		value := seg.Value()
 		var remove bool
-		if value.HasWriter && value.Writer == uid {
+		if value.Writer == uid {
 			// If we are unlocking a writer, then since there can
 			// only ever be one writer and no readers, then this
 			// lock should always be removed from the set.
diff --git a/pkg/sentry/fs/lock/lock_set_functions.go b/pkg/sentry/fs/lock/lock_set_functions.go
index 8a3ace0c1..50a16e662 100644
--- a/pkg/sentry/fs/lock/lock_set_functions.go
+++ b/pkg/sentry/fs/lock/lock_set_functions.go
@@ -44,14 +44,9 @@ func (lockSetFunctions) Merge(r1 LockRange, val1 Lock, r2 LockRange, val2 Lock)
 			return Lock{}, false
 		}
 	}
-	if val1.HasWriter != val2.HasWriter {
+	if val1.Writer != val2.Writer {
 		return Lock{}, false
 	}
-	if val1.HasWriter {
-		if val1.Writer != val2.Writer {
-			return Lock{}, false
-		}
-	}
 	return val1, true
 }
 
@@ -62,7 +57,6 @@ func (lockSetFunctions) Split(r LockRange, val Lock, split uint64) (Lock, Lock)
 	for k, v := range val.Readers {
 		val0.Readers[k] = v
 	}
-	val0.HasWriter = val.HasWriter
 	val0.Writer = val.Writer
 
 	return val, val0
diff --git a/pkg/sentry/fs/lock/lock_test.go b/pkg/sentry/fs/lock/lock_test.go
index ba002aeb7..fad90984b 100644
--- a/pkg/sentry/fs/lock/lock_test.go
+++ b/pkg/sentry/fs/lock/lock_test.go
@@ -42,9 +42,6 @@ func equals(e0, e1 []entry) bool {
 		if !reflect.DeepEqual(e0[i].LockRange, e1[i].LockRange) {
 			return false
 		}
-		if e0[i].Lock.HasWriter != e1[i].Lock.HasWriter {
-			return false
-		}
 		if e0[i].Lock.Writer != e1[i].Lock.Writer {
 			return false
 		}
@@ -105,7 +102,7 @@ func TestCanLock(t *testing.T) {
 			LockRange: LockRange{2048, 3072},
 		},
 		{
-			Lock:      Lock{HasWriter: true, Writer: 1},
+			Lock:      Lock{Writer: 1},
 			LockRange: LockRange{3072, 4096},
 		},
 	})
@@ -241,7 +238,7 @@ func TestSetLock(t *testing.T) {
 			// 0                                  max uint64
 			after: []entry{
 				{
-					Lock:      Lock{HasWriter: true, Writer: 0},
+					Lock:      Lock{Writer: 0},
 					LockRange: LockRange{0, LockEOF},
 				},
 			},
@@ -254,7 +251,7 @@ func TestSetLock(t *testing.T) {
 			// 0                                  max uint64
 			before: []entry{
 				{
-					Lock:      Lock{HasWriter: true, Writer: 0},
+					Lock:      Lock{Writer: 0},
 					LockRange: LockRange{0, LockEOF},
 				},
 			},
@@ -273,7 +270,7 @@ func TestSetLock(t *testing.T) {
 					LockRange: LockRange{0, 4096},
 				},
 				{
-					Lock:      Lock{HasWriter: true, Writer: 0},
+					Lock:      Lock{Writer: 0},
 					LockRange: LockRange{4096, LockEOF},
 				},
 			},
@@ -301,7 +298,7 @@ func TestSetLock(t *testing.T) {
 			// 0          4096                    max uint64
 			after: []entry{
 				{
-					Lock:      Lock{HasWriter: true, Writer: 0},
+					Lock:      Lock{Writer: 0},
 					LockRange: LockRange{0, 4096},
 				},
 				{
@@ -318,7 +315,7 @@ func TestSetLock(t *testing.T) {
 			// 0                                  max uint64
 			before: []entry{
 				{
-					Lock:      Lock{HasWriter: true, Writer: 0},
+					Lock:      Lock{Writer: 0},
 					LockRange: LockRange{0, LockEOF},
 				},
 			},
@@ -550,7 +547,7 @@ func TestSetLock(t *testing.T) {
 					LockRange: LockRange{0, 1024},
 				},
 				{
-					Lock:      Lock{HasWriter: true, Writer: 0},
+					Lock:      Lock{Writer: 0},
 					LockRange: LockRange{1024, 4096},
 				},
 				{
@@ -594,7 +591,7 @@ func TestSetLock(t *testing.T) {
 					LockRange: LockRange{0, 1024},
 				},
 				{
-					Lock:      Lock{HasWriter: true, Writer: 0},
+					Lock:      Lock{Writer: 0},
 					LockRange: LockRange{1024, 3072},
 				},
 				{
@@ -633,7 +630,7 @@ func TestSetLock(t *testing.T) {
 			// 0            1024        2048        4096   max uint64
 			before: []entry{
 				{
-					Lock:      Lock{HasWriter: true, Writer: 0},
+					Lock:      Lock{Writer: 0},
 					LockRange: LockRange{0, 1024},
 				},
 				{
@@ -663,11 +660,11 @@ func TestSetLock(t *testing.T) {
 			// 0            1024                     max uint64
 			after: []entry{
 				{
-					Lock:      Lock{HasWriter: true, Writer: 0},
+					Lock:      Lock{Writer: 0},
 					LockRange: LockRange{0, 1024},
 				},
 				{
-					Lock:      Lock{HasWriter: true, Writer: 0},
+					Lock:      Lock{Writer: 0},
 					LockRange: LockRange{1024, LockEOF},
 				},
 			},
@@ -675,28 +672,30 @@ func TestSetLock(t *testing.T) {
 	}
 
 	for _, test := range tests {
-		l := fill(test.before)
+		t.Run(test.name, func(t *testing.T) {
+			l := fill(test.before)
 
-		r := LockRange{Start: test.start, End: test.end}
-		success := l.lock(test.uid, test.lockType, r)
-		var got []entry
-		for seg := l.FirstSegment(); seg.Ok(); seg = seg.NextSegment() {
-			got = append(got, entry{
-				Lock:      seg.Value(),
-				LockRange: seg.Range(),
-			})
-		}
+			r := LockRange{Start: test.start, End: test.end}
+			success := l.lock(test.uid, test.lockType, r)
+			var got []entry
+			for seg := l.FirstSegment(); seg.Ok(); seg = seg.NextSegment() {
+				got = append(got, entry{
+					Lock:      seg.Value(),
+					LockRange: seg.Range(),
+				})
+			}
 
-		if success != test.success {
-			t.Errorf("%s: setlock(%v, %+v, %d, %d) got success %v, want %v", test.name, test.before, r, test.uid, test.lockType, success, test.success)
-			continue
-		}
+			if success != test.success {
+				t.Errorf("setlock(%v, %+v, %d, %d) got success %v, want %v", test.before, r, test.uid, test.lockType, success, test.success)
+				return
+			}
 
-		if success {
-			if !equals(got, test.after) {
-				t.Errorf("%s: got set %+v, want %+v", test.name, got, test.after)
+			if success {
+				if !equals(got, test.after) {
+					t.Errorf("got set %+v, want %+v", got, test.after)
+				}
 			}
-		}
+		})
 	}
 }
 
@@ -782,7 +781,7 @@ func TestUnlock(t *testing.T) {
 			// 0                                  max uint64
 			before: []entry{
 				{
-					Lock:      Lock{HasWriter: true, Writer: 0},
+					Lock:      Lock{Writer: 0},
 					LockRange: LockRange{0, LockEOF},
 				},
 			},
@@ -824,7 +823,7 @@ func TestUnlock(t *testing.T) {
 			// 0                                  max uint64
 			before: []entry{
 				{
-					Lock:      Lock{HasWriter: true, Writer: 0},
+					Lock:      Lock{Writer: 0},
 					LockRange: LockRange{0, LockEOF},
 				},
 			},
@@ -837,7 +836,7 @@ func TestUnlock(t *testing.T) {
 			// 0     4096                    max uint64
 			after: []entry{
 				{
-					Lock:      Lock{HasWriter: true, Writer: 0},
+					Lock:      Lock{Writer: 0},
 					LockRange: LockRange{4096, LockEOF},
 				},
 			},
@@ -876,7 +875,7 @@ func TestUnlock(t *testing.T) {
 			// 0                                  max uint64
 			before: []entry{
 				{
-					Lock:      Lock{HasWriter: true, Writer: 0},
+					Lock:      Lock{Writer: 0},
 					LockRange: LockRange{0, LockEOF},
 				},
 			},
@@ -889,7 +888,7 @@ func TestUnlock(t *testing.T) {
 			// 0                          4096
 			after: []entry{
 				{
-					Lock:      Lock{HasWriter: true, Writer: 0},
+					Lock:      Lock{Writer: 0},
 					LockRange: LockRange{0, 4096},
 				},
 			},
@@ -906,7 +905,7 @@ func TestUnlock(t *testing.T) {
 					LockRange: LockRange{0, 1024},
 				},
 				{
-					Lock:      Lock{HasWriter: true, Writer: 0},
+					Lock:      Lock{Writer: 0},
 					LockRange: LockRange{1024, 4096},
 				},
 				{
@@ -974,7 +973,7 @@ func TestUnlock(t *testing.T) {
 			// 0        1024    4096            max uint64
 			before: []entry{
 				{
-					Lock:      Lock{HasWriter: true, Writer: 0},
+					Lock:      Lock{Writer: 0},
 					LockRange: LockRange{0, 1024},
 				},
 				{
@@ -991,7 +990,7 @@ func TestUnlock(t *testing.T) {
 			// 0           8    4096            max uint64
 			after: []entry{
 				{
-					Lock:      Lock{HasWriter: true, Writer: 0},
+					Lock:      Lock{Writer: 0},
 					LockRange: LockRange{0, 8},
 				},
 				{
@@ -1008,7 +1007,7 @@ func TestUnlock(t *testing.T) {
 			// 0        1024    4096            max uint64
 			before: []entry{
 				{
-					Lock:      Lock{HasWriter: true, Writer: 0},
+					Lock:      Lock{Writer: 0},
 					LockRange: LockRange{0, 1024},
 				},
 				{
@@ -1025,7 +1024,7 @@ func TestUnlock(t *testing.T) {
 			// 0       1024     4096        8192      max uint64
 			after: []entry{
 				{
-					Lock:      Lock{HasWriter: true, Writer: 0},
+					Lock:      Lock{Writer: 0},
 					LockRange: LockRange{0, 1024},
 				},
 				{
@@ -1041,19 +1040,21 @@ func TestUnlock(t *testing.T) {
 	}
 
 	for _, test := range tests {
-		l := fill(test.before)
+		t.Run(test.name, func(t *testing.T) {
+			l := fill(test.before)
 
-		r := LockRange{Start: test.start, End: test.end}
-		l.unlock(test.uid, r)
-		var got []entry
-		for seg := l.FirstSegment(); seg.Ok(); seg = seg.NextSegment() {
-			got = append(got, entry{
-				Lock:      seg.Value(),
-				LockRange: seg.Range(),
-			})
-		}
-		if !equals(got, test.after) {
-			t.Errorf("%s: got set %+v, want %+v", test.name, got, test.after)
-		}
+			r := LockRange{Start: test.start, End: test.end}
+			l.unlock(test.uid, r)
+			var got []entry
+			for seg := l.FirstSegment(); seg.Ok(); seg = seg.NextSegment() {
+				got = append(got, entry{
+					Lock:      seg.Value(),
+					LockRange: seg.Range(),
+				})
+			}
+			if !equals(got, test.after) {
+				t.Errorf("got set %+v, want %+v", got, test.after)
+			}
+		})
 	}
 }
diff --git a/pkg/sentry/fsimpl/devpts/BUILD b/pkg/sentry/fsimpl/devpts/BUILD
index 585764223..cf440dce8 100644
--- a/pkg/sentry/fsimpl/devpts/BUILD
+++ b/pkg/sentry/fsimpl/devpts/BUILD
@@ -23,6 +23,7 @@ go_library(
         "//pkg/sentry/kernel/auth",
         "//pkg/sentry/unimpl",
         "//pkg/sentry/vfs",
+        "//pkg/sentry/vfs/lock",
         "//pkg/sync",
         "//pkg/syserror",
         "//pkg/usermem",
diff --git a/pkg/sentry/fsimpl/devpts/devpts.go b/pkg/sentry/fsimpl/devpts/devpts.go
index c03c65445..9b0e0cca2 100644
--- a/pkg/sentry/fsimpl/devpts/devpts.go
+++ b/pkg/sentry/fsimpl/devpts/devpts.go
@@ -28,6 +28,7 @@ import (
 	"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"
 )
 
@@ -116,6 +117,8 @@ type rootInode struct {
 	kernfs.InodeNotSymlink
 	kernfs.OrderedChildren
 
+	locks lock.FileLocks
+
 	// Keep a reference to this inode's dentry.
 	dentry kernfs.Dentry
 
@@ -183,7 +186,7 @@ func (i *rootInode) masterClose(t *Terminal) {
 
 // Open implements kernfs.Inode.Open.
 func (i *rootInode) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) {
-	fd, err := kernfs.NewGenericDirectoryFD(rp.Mount(), vfsd, &i.OrderedChildren, &opts)
+	fd, err := kernfs.NewGenericDirectoryFD(rp.Mount(), vfsd, &i.OrderedChildren, &i.locks, &opts)
 	if err != nil {
 		return nil, err
 	}
diff --git a/pkg/sentry/fsimpl/devpts/master.go b/pkg/sentry/fsimpl/devpts/master.go
index 7a7ce5d81..1d22adbe3 100644
--- a/pkg/sentry/fsimpl/devpts/master.go
+++ b/pkg/sentry/fsimpl/devpts/master.go
@@ -22,6 +22,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
 	"gvisor.dev/gvisor/pkg/sentry/unimpl"
 	"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"
@@ -34,6 +35,8 @@ type masterInode struct {
 	kernfs.InodeNotDirectory
 	kernfs.InodeNotSymlink
 
+	locks lock.FileLocks
+
 	// Keep a reference to this inode's dentry.
 	dentry kernfs.Dentry
 
@@ -55,6 +58,7 @@ func (mi *masterInode) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vf
 		inode: mi,
 		t:     t,
 	}
+	fd.LockFD.Init(&mi.locks)
 	if err := fd.vfsfd.Init(fd, opts.Flags, rp.Mount(), vfsd, &vfs.FileDescriptionOptions{}); err != nil {
 		mi.DecRef()
 		return nil, err
@@ -85,6 +89,7 @@ func (mi *masterInode) SetStat(ctx context.Context, vfsfs *vfs.Filesystem, creds
 type masterFileDescription struct {
 	vfsfd vfs.FileDescription
 	vfs.FileDescriptionDefaultImpl
+	vfs.LockFD
 
 	inode *masterInode
 	t     *Terminal
diff --git a/pkg/sentry/fsimpl/devpts/slave.go b/pkg/sentry/fsimpl/devpts/slave.go
index 526cd406c..7fe475080 100644
--- a/pkg/sentry/fsimpl/devpts/slave.go
+++ b/pkg/sentry/fsimpl/devpts/slave.go
@@ -21,6 +21,7 @@ import (
 	"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"
@@ -33,6 +34,8 @@ type slaveInode struct {
 	kernfs.InodeNotDirectory
 	kernfs.InodeNotSymlink
 
+	locks lock.FileLocks
+
 	// Keep a reference to this inode's dentry.
 	dentry kernfs.Dentry
 
@@ -51,6 +54,7 @@ func (si *slaveInode) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs
 	fd := &slaveFileDescription{
 		inode: si,
 	}
+	fd.LockFD.Init(&si.locks)
 	if err := fd.vfsfd.Init(fd, opts.Flags, rp.Mount(), vfsd, &vfs.FileDescriptionOptions{}); err != nil {
 		si.DecRef()
 		return nil, err
@@ -91,6 +95,7 @@ func (si *slaveInode) SetStat(ctx context.Context, vfsfs *vfs.Filesystem, creds
 type slaveFileDescription struct {
 	vfsfd vfs.FileDescription
 	vfs.FileDescriptionDefaultImpl
+	vfs.LockFD
 
 	inode *slaveInode
 }
diff --git a/pkg/sentry/fsimpl/eventfd/eventfd.go b/pkg/sentry/fsimpl/eventfd/eventfd.go
index c573d7935..d12d78b84 100644
--- a/pkg/sentry/fsimpl/eventfd/eventfd.go
+++ b/pkg/sentry/fsimpl/eventfd/eventfd.go
@@ -37,6 +37,7 @@ type EventFileDescription struct {
 	vfsfd vfs.FileDescription
 	vfs.FileDescriptionDefaultImpl
 	vfs.DentryMetadataFileDescriptionImpl
+	vfs.NoLockFD
 
 	// queue is used to notify interested parties when the event object
 	// becomes readable or writable.
diff --git a/pkg/sentry/fsimpl/ext/BUILD b/pkg/sentry/fsimpl/ext/BUILD
index ff861d0fe..973fa0def 100644
--- a/pkg/sentry/fsimpl/ext/BUILD
+++ b/pkg/sentry/fsimpl/ext/BUILD
@@ -60,6 +60,7 @@ go_library(
         "//pkg/sentry/socket/unix/transport",
         "//pkg/sentry/syscalls/linux",
         "//pkg/sentry/vfs",
+        "//pkg/sentry/vfs/lock",
         "//pkg/sync",
         "//pkg/syserror",
         "//pkg/usermem",
diff --git a/pkg/sentry/fsimpl/ext/file_description.go b/pkg/sentry/fsimpl/ext/file_description.go
index 92f7da40d..90b086468 100644
--- a/pkg/sentry/fsimpl/ext/file_description.go
+++ b/pkg/sentry/fsimpl/ext/file_description.go
@@ -26,6 +26,7 @@ import (
 type fileDescription struct {
 	vfsfd vfs.FileDescription
 	vfs.FileDescriptionDefaultImpl
+	vfs.LockFD
 }
 
 func (fd *fileDescription) filesystem() *filesystem {
diff --git a/pkg/sentry/fsimpl/ext/inode.go b/pkg/sentry/fsimpl/ext/inode.go
index 485f86f4b..e4b434b13 100644
--- a/pkg/sentry/fsimpl/ext/inode.go
+++ b/pkg/sentry/fsimpl/ext/inode.go
@@ -22,6 +22,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/fsimpl/ext/disklayout"
 	"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"
 )
 
@@ -54,6 +55,8 @@ type inode struct {
 	// diskInode gives us access to the inode struct on disk. Immutable.
 	diskInode disklayout.Inode
 
+	locks lock.FileLocks
+
 	// This is immutable. The first field of the implementations must have inode
 	// as the first field to ensure temporality.
 	impl interface{}
@@ -157,6 +160,7 @@ func (in *inode) open(rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts *vfs.OpenOpt
 	switch in.impl.(type) {
 	case *regularFile:
 		var fd regularFileFD
+		fd.LockFD.Init(&in.locks)
 		if err := fd.vfsfd.Init(&fd, opts.Flags, mnt, vfsd, &vfs.FileDescriptionOptions{}); err != nil {
 			return nil, err
 		}
@@ -168,6 +172,7 @@ func (in *inode) open(rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts *vfs.OpenOpt
 			return nil, syserror.EISDIR
 		}
 		var fd directoryFD
+		fd.LockFD.Init(&in.locks)
 		if err := fd.vfsfd.Init(&fd, opts.Flags, mnt, vfsd, &vfs.FileDescriptionOptions{}); err != nil {
 			return nil, err
 		}
@@ -178,6 +183,7 @@ func (in *inode) open(rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts *vfs.OpenOpt
 			return nil, syserror.ELOOP
 		}
 		var fd symlinkFD
+		fd.LockFD.Init(&in.locks)
 		fd.vfsfd.Init(&fd, opts.Flags, mnt, vfsd, &vfs.FileDescriptionOptions{})
 		return &fd.vfsfd, nil
 	default:
diff --git a/pkg/sentry/fsimpl/ext/regular_file.go b/pkg/sentry/fsimpl/ext/regular_file.go
index 30135ddb0..f7015c44f 100644
--- a/pkg/sentry/fsimpl/ext/regular_file.go
+++ b/pkg/sentry/fsimpl/ext/regular_file.go
@@ -77,6 +77,7 @@ func (in *inode) isRegular() bool {
 // vfs.FileDescriptionImpl.
 type regularFileFD struct {
 	fileDescription
+	vfs.LockFD
 
 	// off is the file offset. off is accessed using atomic memory operations.
 	off int64
diff --git a/pkg/sentry/fsimpl/gofer/BUILD b/pkg/sentry/fsimpl/gofer/BUILD
index f5f35a3bc..5cdeeaeb5 100644
--- a/pkg/sentry/fsimpl/gofer/BUILD
+++ b/pkg/sentry/fsimpl/gofer/BUILD
@@ -54,6 +54,7 @@ go_library(
         "//pkg/p9",
         "//pkg/safemem",
         "//pkg/sentry/fs/fsutil",
+        "//pkg/sentry/fs/lock",
         "//pkg/sentry/fsimpl/host",
         "//pkg/sentry/hostfd",
         "//pkg/sentry/kernel",
@@ -68,6 +69,7 @@ go_library(
         "//pkg/sentry/socket/unix/transport",
         "//pkg/sentry/usage",
         "//pkg/sentry/vfs",
+        "//pkg/sentry/vfs/lock",
         "//pkg/syserr",
         "//pkg/syserror",
         "//pkg/unet",
diff --git a/pkg/sentry/fsimpl/gofer/filesystem.go b/pkg/sentry/fsimpl/gofer/filesystem.go
index 36e0e1856..40933b74b 100644
--- a/pkg/sentry/fsimpl/gofer/filesystem.go
+++ b/pkg/sentry/fsimpl/gofer/filesystem.go
@@ -801,6 +801,7 @@ func (d *dentry) openLocked(ctx context.Context, rp *vfs.ResolvingPath, opts *vf
 				return nil, err
 			}
 			fd := &regularFileFD{}
+			fd.LockFD.Init(&d.locks)
 			if err := fd.vfsfd.Init(fd, opts.Flags, mnt, &d.vfsd, &vfs.FileDescriptionOptions{
 				AllowDirectIO: true,
 			}); err != nil {
@@ -826,6 +827,7 @@ func (d *dentry) openLocked(ctx context.Context, rp *vfs.ResolvingPath, opts *vf
 			}
 		}
 		fd := &directoryFD{}
+		fd.LockFD.Init(&d.locks)
 		if err := fd.vfsfd.Init(fd, opts.Flags, mnt, &d.vfsd, &vfs.FileDescriptionOptions{}); err != nil {
 			return nil, err
 		}
@@ -842,7 +844,7 @@ func (d *dentry) openLocked(ctx context.Context, rp *vfs.ResolvingPath, opts *vf
 		}
 	case linux.S_IFIFO:
 		if d.isSynthetic() {
-			return d.pipe.Open(ctx, mnt, &d.vfsd, opts.Flags)
+			return d.pipe.Open(ctx, mnt, &d.vfsd, opts.Flags, &d.locks)
 		}
 	}
 	return d.openSpecialFileLocked(ctx, mnt, opts)
@@ -902,7 +904,7 @@ retry:
 			return nil, err
 		}
 	}
-	fd, err := newSpecialFileFD(h, mnt, d, opts.Flags)
+	fd, err := newSpecialFileFD(h, mnt, d, &d.locks, opts.Flags)
 	if err != nil {
 		h.close(ctx)
 		return nil, err
@@ -989,6 +991,7 @@ func (d *dentry) createAndOpenChildLocked(ctx context.Context, rp *vfs.Resolving
 	var childVFSFD *vfs.FileDescription
 	if useRegularFileFD {
 		fd := &regularFileFD{}
+		fd.LockFD.Init(&child.locks)
 		if err := fd.vfsfd.Init(fd, opts.Flags, mnt, &child.vfsd, &vfs.FileDescriptionOptions{
 			AllowDirectIO: true,
 		}); err != nil {
@@ -1003,7 +1006,7 @@ func (d *dentry) createAndOpenChildLocked(ctx context.Context, rp *vfs.Resolving
 		if fdobj != nil {
 			h.fd = int32(fdobj.Release())
 		}
-		fd, err := newSpecialFileFD(h, mnt, child, opts.Flags)
+		fd, err := newSpecialFileFD(h, mnt, child, &d.locks, opts.Flags)
 		if err != nil {
 			h.close(ctx)
 			return nil, err
diff --git a/pkg/sentry/fsimpl/gofer/gofer.go b/pkg/sentry/fsimpl/gofer/gofer.go
index 3f3bd56f0..0d88a328e 100644
--- a/pkg/sentry/fsimpl/gofer/gofer.go
+++ b/pkg/sentry/fsimpl/gofer/gofer.go
@@ -45,6 +45,7 @@ import (
 	"gvisor.dev/gvisor/pkg/log"
 	"gvisor.dev/gvisor/pkg/p9"
 	"gvisor.dev/gvisor/pkg/sentry/fs/fsutil"
+	fslock "gvisor.dev/gvisor/pkg/sentry/fs/lock"
 	"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
 	"gvisor.dev/gvisor/pkg/sentry/kernel/pipe"
 	ktime "gvisor.dev/gvisor/pkg/sentry/kernel/time"
@@ -52,6 +53,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/pgalloc"
 	"gvisor.dev/gvisor/pkg/sentry/socket/unix/transport"
 	"gvisor.dev/gvisor/pkg/sentry/vfs"
+	"gvisor.dev/gvisor/pkg/sentry/vfs/lock"
 	"gvisor.dev/gvisor/pkg/syserror"
 	"gvisor.dev/gvisor/pkg/unet"
 	"gvisor.dev/gvisor/pkg/usermem"
@@ -662,6 +664,8 @@ type dentry struct {
 	// If this dentry represents a synthetic named pipe, pipe is the pipe
 	// endpoint bound to this file.
 	pipe *pipe.VFSPipe
+
+	locks lock.FileLocks
 }
 
 // dentryAttrMask returns a p9.AttrMask enabling all attributes used by the
@@ -1366,6 +1370,9 @@ func (d *dentry) decLinks() {
 type fileDescription struct {
 	vfsfd vfs.FileDescription
 	vfs.FileDescriptionDefaultImpl
+	vfs.LockFD
+
+	lockLogging sync.Once
 }
 
 func (fd *fileDescription) filesystem() *filesystem {
@@ -1416,3 +1423,19 @@ func (fd *fileDescription) Setxattr(ctx context.Context, opts vfs.SetxattrOption
 func (fd *fileDescription) Removexattr(ctx context.Context, name string) error {
 	return fd.dentry().removexattr(ctx, auth.CredentialsFromContext(ctx), name)
 }
+
+// LockBSD implements vfs.FileDescriptionImpl.LockBSD.
+func (fd *fileDescription) LockBSD(ctx context.Context, uid fslock.UniqueID, t fslock.LockType, block fslock.Blocker) error {
+	fd.lockLogging.Do(func() {
+		log.Infof("File lock using gofer file handled internally.")
+	})
+	return fd.LockFD.LockBSD(ctx, uid, t, block)
+}
+
+// LockPOSIX implements vfs.FileDescriptionImpl.LockPOSIX.
+func (fd *fileDescription) LockPOSIX(ctx context.Context, uid fslock.UniqueID, t fslock.LockType, rng fslock.LockRange, block fslock.Blocker) error {
+	fd.lockLogging.Do(func() {
+		log.Infof("Range lock using gofer file handled internally.")
+	})
+	return fd.LockFD.LockPOSIX(ctx, uid, t, rng, block)
+}
diff --git a/pkg/sentry/fsimpl/gofer/special_file.go b/pkg/sentry/fsimpl/gofer/special_file.go
index ff6126b87..289efdd25 100644
--- a/pkg/sentry/fsimpl/gofer/special_file.go
+++ b/pkg/sentry/fsimpl/gofer/special_file.go
@@ -22,6 +22,7 @@ import (
 	"gvisor.dev/gvisor/pkg/fdnotifier"
 	"gvisor.dev/gvisor/pkg/safemem"
 	"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"
@@ -51,7 +52,7 @@ type specialFileFD struct {
 	off int64
 }
 
-func newSpecialFileFD(h handle, mnt *vfs.Mount, d *dentry, flags uint32) (*specialFileFD, error) {
+func newSpecialFileFD(h handle, mnt *vfs.Mount, d *dentry, locks *lock.FileLocks, flags uint32) (*specialFileFD, error) {
 	ftype := d.fileType()
 	seekable := ftype == linux.S_IFREG
 	mayBlock := ftype == linux.S_IFIFO || ftype == linux.S_IFSOCK
@@ -60,6 +61,7 @@ func newSpecialFileFD(h handle, mnt *vfs.Mount, d *dentry, flags uint32) (*speci
 		seekable: seekable,
 		mayBlock: mayBlock,
 	}
+	fd.LockFD.Init(locks)
 	if mayBlock && h.fd >= 0 {
 		if err := fdnotifier.AddFD(h.fd, &fd.queue); err != nil {
 			return nil, err
diff --git a/pkg/sentry/fsimpl/host/BUILD b/pkg/sentry/fsimpl/host/BUILD
index ca0fe6d2b..54f16ad63 100644
--- a/pkg/sentry/fsimpl/host/BUILD
+++ b/pkg/sentry/fsimpl/host/BUILD
@@ -39,6 +39,7 @@ go_library(
         "//pkg/sentry/unimpl",
         "//pkg/sentry/uniqueid",
         "//pkg/sentry/vfs",
+        "//pkg/sentry/vfs/lock",
         "//pkg/sync",
         "//pkg/syserr",
         "//pkg/syserror",
diff --git a/pkg/sentry/fsimpl/host/host.go b/pkg/sentry/fsimpl/host/host.go
index 18b127521..5ec5100b8 100644
--- a/pkg/sentry/fsimpl/host/host.go
+++ b/pkg/sentry/fsimpl/host/host.go
@@ -34,6 +34,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/memmap"
 	unixsocket "gvisor.dev/gvisor/pkg/sentry/socket/unix"
 	"gvisor.dev/gvisor/pkg/sentry/vfs"
+	"gvisor.dev/gvisor/pkg/sentry/vfs/lock"
 	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 	"gvisor.dev/gvisor/pkg/usermem"
@@ -182,6 +183,8 @@ type inode struct {
 	kernfs.InodeNotDirectory
 	kernfs.InodeNotSymlink
 
+	locks lock.FileLocks
+
 	// When the reference count reaches zero, the host fd is closed.
 	refs.AtomicRefCount
 
@@ -468,7 +471,7 @@ func (i *inode) open(ctx context.Context, d *vfs.Dentry, mnt *vfs.Mount, flags u
 			return nil, err
 		}
 		// Currently, we only allow Unix sockets to be imported.
-		return unixsocket.NewFileDescription(ep, ep.Type(), flags, mnt, d)
+		return unixsocket.NewFileDescription(ep, ep.Type(), flags, mnt, d, &i.locks)
 	}
 
 	// TODO(gvisor.dev/issue/1672): Whitelist specific file types here, so that
@@ -478,6 +481,7 @@ func (i *inode) open(ctx context.Context, d *vfs.Dentry, mnt *vfs.Mount, flags u
 			fileDescription: fileDescription{inode: i},
 			termios:         linux.DefaultSlaveTermios,
 		}
+		fd.LockFD.Init(&i.locks)
 		vfsfd := &fd.vfsfd
 		if err := vfsfd.Init(fd, flags, mnt, d, &vfs.FileDescriptionOptions{}); err != nil {
 			return nil, err
@@ -486,6 +490,7 @@ func (i *inode) open(ctx context.Context, d *vfs.Dentry, mnt *vfs.Mount, flags u
 	}
 
 	fd := &fileDescription{inode: i}
+	fd.LockFD.Init(&i.locks)
 	vfsfd := &fd.vfsfd
 	if err := vfsfd.Init(fd, flags, mnt, d, &vfs.FileDescriptionOptions{}); err != nil {
 		return nil, err
@@ -497,6 +502,7 @@ func (i *inode) open(ctx context.Context, d *vfs.Dentry, mnt *vfs.Mount, flags u
 type fileDescription struct {
 	vfsfd vfs.FileDescription
 	vfs.FileDescriptionDefaultImpl
+	vfs.LockFD
 
 	// inode is vfsfd.Dentry().Impl().(*kernfs.Dentry).Inode().(*inode), but
 	// cached to reduce indirections and casting. fileDescription does not hold
diff --git a/pkg/sentry/fsimpl/kernfs/BUILD b/pkg/sentry/fsimpl/kernfs/BUILD
index ef34cb28a..0299dbde9 100644
--- a/pkg/sentry/fsimpl/kernfs/BUILD
+++ b/pkg/sentry/fsimpl/kernfs/BUILD
@@ -49,6 +49,7 @@ go_library(
         "//pkg/sentry/memmap",
         "//pkg/sentry/socket/unix/transport",
         "//pkg/sentry/vfs",
+        "//pkg/sentry/vfs/lock",
         "//pkg/sync",
         "//pkg/syserror",
         "//pkg/usermem",
@@ -67,6 +68,7 @@ go_test(
         "//pkg/sentry/fsimpl/testutil",
         "//pkg/sentry/kernel/auth",
         "//pkg/sentry/vfs",
+        "//pkg/sentry/vfs/lock",
         "//pkg/syserror",
         "//pkg/usermem",
         "@com_github_google_go-cmp//cmp:go_default_library",
diff --git a/pkg/sentry/fsimpl/kernfs/dynamic_bytes_file.go b/pkg/sentry/fsimpl/kernfs/dynamic_bytes_file.go
index 1568a9d49..6418de0a3 100644
--- a/pkg/sentry/fsimpl/kernfs/dynamic_bytes_file.go
+++ b/pkg/sentry/fsimpl/kernfs/dynamic_bytes_file.go
@@ -21,6 +21,7 @@ import (
 	"gvisor.dev/gvisor/pkg/context"
 	"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"
 )
@@ -38,7 +39,8 @@ type DynamicBytesFile struct {
 	InodeNotDirectory
 	InodeNotSymlink
 
-	data vfs.DynamicBytesSource
+	locks lock.FileLocks
+	data  vfs.DynamicBytesSource
 }
 
 var _ Inode = (*DynamicBytesFile)(nil)
@@ -55,7 +57,7 @@ func (f *DynamicBytesFile) Init(creds *auth.Credentials, devMajor, devMinor uint
 // Open implements Inode.Open.
 func (f *DynamicBytesFile) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) {
 	fd := &DynamicBytesFD{}
-	if err := fd.Init(rp.Mount(), vfsd, f.data, opts.Flags); err != nil {
+	if err := fd.Init(rp.Mount(), vfsd, f.data, &f.locks, opts.Flags); err != nil {
 		return nil, err
 	}
 	return &fd.vfsfd, nil
@@ -77,13 +79,15 @@ func (*DynamicBytesFile) SetStat(context.Context, *vfs.Filesystem, *auth.Credent
 type DynamicBytesFD struct {
 	vfs.FileDescriptionDefaultImpl
 	vfs.DynamicBytesFileDescriptionImpl
+	vfs.LockFD
 
 	vfsfd vfs.FileDescription
 	inode Inode
 }
 
 // Init initializes a DynamicBytesFD.
-func (fd *DynamicBytesFD) Init(m *vfs.Mount, d *vfs.Dentry, data vfs.DynamicBytesSource, flags uint32) error {
+func (fd *DynamicBytesFD) Init(m *vfs.Mount, d *vfs.Dentry, data vfs.DynamicBytesSource, locks *lock.FileLocks, flags uint32) error {
+	fd.LockFD.Init(locks)
 	if err := fd.vfsfd.Init(fd, flags, m, d, &vfs.FileDescriptionOptions{}); err != nil {
 		return err
 	}
diff --git a/pkg/sentry/fsimpl/kernfs/fd_impl_util.go b/pkg/sentry/fsimpl/kernfs/fd_impl_util.go
index 8284e76a7..33a5968ca 100644
--- a/pkg/sentry/fsimpl/kernfs/fd_impl_util.go
+++ b/pkg/sentry/fsimpl/kernfs/fd_impl_util.go
@@ -22,6 +22,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
 	"gvisor.dev/gvisor/pkg/sentry/memmap"
 	"gvisor.dev/gvisor/pkg/sentry/vfs"
+	"gvisor.dev/gvisor/pkg/sentry/vfs/lock"
 	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 	"gvisor.dev/gvisor/pkg/usermem"
@@ -42,6 +43,7 @@ import (
 type GenericDirectoryFD struct {
 	vfs.FileDescriptionDefaultImpl
 	vfs.DirectoryFileDescriptionDefaultImpl
+	vfs.LockFD
 
 	vfsfd    vfs.FileDescription
 	children *OrderedChildren
@@ -55,9 +57,9 @@ type GenericDirectoryFD struct {
 
 // NewGenericDirectoryFD creates a new GenericDirectoryFD and returns its
 // dentry.
-func NewGenericDirectoryFD(m *vfs.Mount, d *vfs.Dentry, children *OrderedChildren, opts *vfs.OpenOptions) (*GenericDirectoryFD, error) {
+func NewGenericDirectoryFD(m *vfs.Mount, d *vfs.Dentry, children *OrderedChildren, locks *lock.FileLocks, opts *vfs.OpenOptions) (*GenericDirectoryFD, error) {
 	fd := &GenericDirectoryFD{}
-	if err := fd.Init(children, opts); err != nil {
+	if err := fd.Init(children, locks, opts); err != nil {
 		return nil, err
 	}
 	if err := fd.vfsfd.Init(fd, opts.Flags, m, d, &vfs.FileDescriptionOptions{}); err != nil {
@@ -69,11 +71,12 @@ func NewGenericDirectoryFD(m *vfs.Mount, d *vfs.Dentry, children *OrderedChildre
 // Init initializes a GenericDirectoryFD. Use it when overriding
 // GenericDirectoryFD. Caller must call fd.VFSFileDescription.Init() with the
 // correct implementation.
-func (fd *GenericDirectoryFD) Init(children *OrderedChildren, opts *vfs.OpenOptions) error {
+func (fd *GenericDirectoryFD) Init(children *OrderedChildren, locks *lock.FileLocks, opts *vfs.OpenOptions) error {
 	if vfs.AccessTypesForOpenFlags(opts)&vfs.MayWrite != 0 {
 		// Can't open directories for writing.
 		return syserror.EISDIR
 	}
+	fd.LockFD.Init(locks)
 	fd.children = children
 	return nil
 }
diff --git a/pkg/sentry/fsimpl/kernfs/inode_impl_util.go b/pkg/sentry/fsimpl/kernfs/inode_impl_util.go
index 982daa2e6..0e4927215 100644
--- a/pkg/sentry/fsimpl/kernfs/inode_impl_util.go
+++ b/pkg/sentry/fsimpl/kernfs/inode_impl_util.go
@@ -23,6 +23,7 @@ import (
 	"gvisor.dev/gvisor/pkg/refs"
 	"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
 	"gvisor.dev/gvisor/pkg/sentry/vfs"
+	"gvisor.dev/gvisor/pkg/sentry/vfs/lock"
 	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 )
@@ -555,6 +556,8 @@ type StaticDirectory struct {
 	InodeAttrs
 	InodeNoDynamicLookup
 	OrderedChildren
+
+	locks lock.FileLocks
 }
 
 var _ Inode = (*StaticDirectory)(nil)
@@ -584,7 +587,7 @@ func (s *StaticDirectory) Init(creds *auth.Credentials, devMajor, devMinor uint3
 
 // Open implements kernfs.Inode.
 func (s *StaticDirectory) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) {
-	fd, err := NewGenericDirectoryFD(rp.Mount(), vfsd, &s.OrderedChildren, &opts)
+	fd, err := NewGenericDirectoryFD(rp.Mount(), vfsd, &s.OrderedChildren, &s.locks, &opts)
 	if err != nil {
 		return nil, err
 	}
diff --git a/pkg/sentry/fsimpl/kernfs/kernfs_test.go b/pkg/sentry/fsimpl/kernfs/kernfs_test.go
index 412cf6ac9..6749facf7 100644
--- a/pkg/sentry/fsimpl/kernfs/kernfs_test.go
+++ b/pkg/sentry/fsimpl/kernfs/kernfs_test.go
@@ -27,6 +27,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/fsimpl/testutil"
 	"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"
 )
@@ -100,8 +101,10 @@ type readonlyDir struct {
 	kernfs.InodeNotSymlink
 	kernfs.InodeNoDynamicLookup
 	kernfs.InodeDirectoryNoNewChildren
-
 	kernfs.OrderedChildren
+
+	locks lock.FileLocks
+
 	dentry kernfs.Dentry
 }
 
@@ -117,7 +120,7 @@ func (fs *filesystem) newReadonlyDir(creds *auth.Credentials, mode linux.FileMod
 }
 
 func (d *readonlyDir) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) {
-	fd, err := kernfs.NewGenericDirectoryFD(rp.Mount(), vfsd, &d.OrderedChildren, &opts)
+	fd, err := kernfs.NewGenericDirectoryFD(rp.Mount(), vfsd, &d.OrderedChildren, &d.locks, &opts)
 	if err != nil {
 		return nil, err
 	}
@@ -128,10 +131,12 @@ type dir struct {
 	attrs
 	kernfs.InodeNotSymlink
 	kernfs.InodeNoDynamicLookup
+	kernfs.OrderedChildren
+
+	locks lock.FileLocks
 
 	fs     *filesystem
 	dentry kernfs.Dentry
-	kernfs.OrderedChildren
 }
 
 func (fs *filesystem) newDir(creds *auth.Credentials, mode linux.FileMode, contents map[string]*kernfs.Dentry) *kernfs.Dentry {
@@ -147,7 +152,7 @@ func (fs *filesystem) newDir(creds *auth.Credentials, mode linux.FileMode, conte
 }
 
 func (d *dir) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) {
-	fd, err := kernfs.NewGenericDirectoryFD(rp.Mount(), vfsd, &d.OrderedChildren, &opts)
+	fd, err := kernfs.NewGenericDirectoryFD(rp.Mount(), vfsd, &d.OrderedChildren, &d.locks, &opts)
 	if err != nil {
 		return nil, err
 	}
diff --git a/pkg/sentry/fsimpl/pipefs/BUILD b/pkg/sentry/fsimpl/pipefs/BUILD
index 5950a2d59..c618dbe6c 100644
--- a/pkg/sentry/fsimpl/pipefs/BUILD
+++ b/pkg/sentry/fsimpl/pipefs/BUILD
@@ -15,6 +15,7 @@ go_library(
         "//pkg/sentry/kernel/pipe",
         "//pkg/sentry/kernel/time",
         "//pkg/sentry/vfs",
+        "//pkg/sentry/vfs/lock",
         "//pkg/syserror",
         "//pkg/usermem",
     ],
diff --git a/pkg/sentry/fsimpl/pipefs/pipefs.go b/pkg/sentry/fsimpl/pipefs/pipefs.go
index cab771211..e4dabaa33 100644
--- a/pkg/sentry/fsimpl/pipefs/pipefs.go
+++ b/pkg/sentry/fsimpl/pipefs/pipefs.go
@@ -27,6 +27,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/kernel/pipe"
 	ktime "gvisor.dev/gvisor/pkg/sentry/kernel/time"
 	"gvisor.dev/gvisor/pkg/sentry/vfs"
+	"gvisor.dev/gvisor/pkg/sentry/vfs/lock"
 	"gvisor.dev/gvisor/pkg/syserror"
 	"gvisor.dev/gvisor/pkg/usermem"
 )
@@ -81,7 +82,8 @@ type inode struct {
 	kernfs.InodeNotSymlink
 	kernfs.InodeNoopRefCount
 
-	pipe *pipe.VFSPipe
+	locks lock.FileLocks
+	pipe  *pipe.VFSPipe
 
 	ino uint64
 	uid auth.KUID
@@ -147,7 +149,7 @@ func (i *inode) SetStat(ctx context.Context, vfsfs *vfs.Filesystem, creds *auth.
 
 // Open implements kernfs.Inode.Open.
 func (i *inode) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) {
-	return i.pipe.Open(ctx, rp.Mount(), vfsd, opts.Flags)
+	return i.pipe.Open(ctx, rp.Mount(), vfsd, opts.Flags, &i.locks)
 }
 
 // NewConnectedPipeFDs returns a pair of FileDescriptions representing the read
diff --git a/pkg/sentry/fsimpl/proc/BUILD b/pkg/sentry/fsimpl/proc/BUILD
index 17c1342b5..351ba4ee9 100644
--- a/pkg/sentry/fsimpl/proc/BUILD
+++ b/pkg/sentry/fsimpl/proc/BUILD
@@ -35,6 +35,7 @@ go_library(
         "//pkg/sentry/socket/unix/transport",
         "//pkg/sentry/usage",
         "//pkg/sentry/vfs",
+        "//pkg/sentry/vfs/lock",
         "//pkg/syserror",
         "//pkg/tcpip/header",
         "//pkg/usermem",
diff --git a/pkg/sentry/fsimpl/proc/subtasks.go b/pkg/sentry/fsimpl/proc/subtasks.go
index 36a911db4..e2cdb7ee9 100644
--- a/pkg/sentry/fsimpl/proc/subtasks.go
+++ b/pkg/sentry/fsimpl/proc/subtasks.go
@@ -24,6 +24,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/kernel"
 	"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"
 )
 
@@ -37,6 +38,8 @@ type subtasksInode struct {
 	kernfs.OrderedChildren
 	kernfs.AlwaysValid
 
+	locks lock.FileLocks
+
 	fs                *filesystem
 	task              *kernel.Task
 	pidns             *kernel.PIDNamespace
@@ -153,7 +156,7 @@ func (fd *subtasksFD) SetStat(ctx context.Context, opts vfs.SetStatOptions) erro
 // Open implements kernfs.Inode.
 func (i *subtasksInode) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) {
 	fd := &subtasksFD{task: i.task}
-	if err := fd.Init(&i.OrderedChildren, &opts); err != nil {
+	if err := fd.Init(&i.OrderedChildren, &i.locks, &opts); err != nil {
 		return nil, err
 	}
 	if err := fd.VFSFileDescription().Init(fd, opts.Flags, rp.Mount(), vfsd, &vfs.FileDescriptionOptions{}); err != nil {
diff --git a/pkg/sentry/fsimpl/proc/task.go b/pkg/sentry/fsimpl/proc/task.go
index 482055db1..44078a765 100644
--- a/pkg/sentry/fsimpl/proc/task.go
+++ b/pkg/sentry/fsimpl/proc/task.go
@@ -25,6 +25,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
 	"gvisor.dev/gvisor/pkg/sentry/mm"
 	"gvisor.dev/gvisor/pkg/sentry/vfs"
+	"gvisor.dev/gvisor/pkg/sentry/vfs/lock"
 	"gvisor.dev/gvisor/pkg/syserror"
 )
 
@@ -38,6 +39,8 @@ type taskInode struct {
 	kernfs.InodeAttrs
 	kernfs.OrderedChildren
 
+	locks lock.FileLocks
+
 	task *kernel.Task
 }
 
@@ -103,7 +106,7 @@ func (i *taskInode) Valid(ctx context.Context) bool {
 
 // Open implements kernfs.Inode.
 func (i *taskInode) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) {
-	fd, err := kernfs.NewGenericDirectoryFD(rp.Mount(), vfsd, &i.OrderedChildren, &opts)
+	fd, err := kernfs.NewGenericDirectoryFD(rp.Mount(), vfsd, &i.OrderedChildren, &i.locks, &opts)
 	if err != nil {
 		return nil, err
 	}
diff --git a/pkg/sentry/fsimpl/proc/task_fds.go b/pkg/sentry/fsimpl/proc/task_fds.go
index 44ccc9e4a..ef6c1d04f 100644
--- a/pkg/sentry/fsimpl/proc/task_fds.go
+++ b/pkg/sentry/fsimpl/proc/task_fds.go
@@ -27,6 +27,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/kernel"
 	"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"
 )
 
@@ -53,6 +54,8 @@ func taskFDExists(t *kernel.Task, fd int32) bool {
 }
 
 type fdDir struct {
+	locks lock.FileLocks
+
 	fs   *filesystem
 	task *kernel.Task
 
@@ -143,7 +146,7 @@ func (i *fdDirInode) Lookup(ctx context.Context, name string) (*vfs.Dentry, erro
 
 // Open implements kernfs.Inode.
 func (i *fdDirInode) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) {
-	fd, err := kernfs.NewGenericDirectoryFD(rp.Mount(), vfsd, &i.OrderedChildren, &opts)
+	fd, err := kernfs.NewGenericDirectoryFD(rp.Mount(), vfsd, &i.OrderedChildren, &i.locks, &opts)
 	if err != nil {
 		return nil, err
 	}
@@ -270,7 +273,7 @@ func (i *fdInfoDirInode) Lookup(ctx context.Context, name string) (*vfs.Dentry,
 
 // Open implements kernfs.Inode.
 func (i *fdInfoDirInode) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) {
-	fd, err := kernfs.NewGenericDirectoryFD(rp.Mount(), vfsd, &i.OrderedChildren, &opts)
+	fd, err := kernfs.NewGenericDirectoryFD(rp.Mount(), vfsd, &i.OrderedChildren, &i.locks, &opts)
 	if err != nil {
 		return nil, err
 	}
diff --git a/pkg/sentry/fsimpl/proc/task_files.go b/pkg/sentry/fsimpl/proc/task_files.go
index 2f297e48a..e5eaa91cd 100644
--- a/pkg/sentry/fsimpl/proc/task_files.go
+++ b/pkg/sentry/fsimpl/proc/task_files.go
@@ -30,6 +30,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/mm"
 	"gvisor.dev/gvisor/pkg/sentry/usage"
 	"gvisor.dev/gvisor/pkg/sentry/vfs"
+	"gvisor.dev/gvisor/pkg/sentry/vfs/lock"
 	"gvisor.dev/gvisor/pkg/syserror"
 	"gvisor.dev/gvisor/pkg/usermem"
 )
@@ -775,6 +776,8 @@ type namespaceInode struct {
 	kernfs.InodeNoopRefCount
 	kernfs.InodeNotDirectory
 	kernfs.InodeNotSymlink
+
+	locks lock.FileLocks
 }
 
 var _ kernfs.Inode = (*namespaceInode)(nil)
@@ -791,6 +794,7 @@ func (i *namespaceInode) Init(creds *auth.Credentials, devMajor, devMinor uint32
 func (i *namespaceInode) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) {
 	fd := &namespaceFD{inode: i}
 	i.IncRef()
+	fd.LockFD.Init(&i.locks)
 	if err := fd.vfsfd.Init(fd, opts.Flags, rp.Mount(), vfsd, &vfs.FileDescriptionOptions{}); err != nil {
 		return nil, err
 	}
@@ -801,6 +805,7 @@ func (i *namespaceInode) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *
 // /proc/[pid]/ns/*.
 type namespaceFD struct {
 	vfs.FileDescriptionDefaultImpl
+	vfs.LockFD
 
 	vfsfd vfs.FileDescription
 	inode *namespaceInode
@@ -825,8 +830,3 @@ func (fd *namespaceFD) SetStat(ctx context.Context, opts vfs.SetStatOptions) err
 func (fd *namespaceFD) Release() {
 	fd.inode.DecRef()
 }
-
-// OnClose implements FileDescriptionImpl.
-func (*namespaceFD) OnClose(context.Context) error {
-	return nil
-}
diff --git a/pkg/sentry/fsimpl/proc/tasks.go b/pkg/sentry/fsimpl/proc/tasks.go
index b51d43954..58c8b9d05 100644
--- a/pkg/sentry/fsimpl/proc/tasks.go
+++ b/pkg/sentry/fsimpl/proc/tasks.go
@@ -25,6 +25,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/kernel"
 	"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"
 )
 
@@ -43,6 +44,8 @@ type tasksInode struct {
 	kernfs.OrderedChildren
 	kernfs.AlwaysValid
 
+	locks lock.FileLocks
+
 	fs    *filesystem
 	pidns *kernel.PIDNamespace
 
@@ -197,7 +200,7 @@ func (i *tasksInode) IterDirents(ctx context.Context, cb vfs.IterDirentsCallback
 
 // Open implements kernfs.Inode.
 func (i *tasksInode) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) {
-	fd, err := kernfs.NewGenericDirectoryFD(rp.Mount(), vfsd, &i.OrderedChildren, &opts)
+	fd, err := kernfs.NewGenericDirectoryFD(rp.Mount(), vfsd, &i.OrderedChildren, &i.locks, &opts)
 	if err != nil {
 		return nil, err
 	}
diff --git a/pkg/sentry/fsimpl/signalfd/signalfd.go b/pkg/sentry/fsimpl/signalfd/signalfd.go
index d29ef3f83..242ba9b5d 100644
--- a/pkg/sentry/fsimpl/signalfd/signalfd.go
+++ b/pkg/sentry/fsimpl/signalfd/signalfd.go
@@ -31,6 +31,7 @@ type SignalFileDescription struct {
 	vfsfd vfs.FileDescription
 	vfs.FileDescriptionDefaultImpl
 	vfs.DentryMetadataFileDescriptionImpl
+	vfs.NoLockFD
 
 	// target is the original signal target task.
 	//
diff --git a/pkg/sentry/fsimpl/sys/BUILD b/pkg/sentry/fsimpl/sys/BUILD
index a741e2bb6..237f17def 100644
--- a/pkg/sentry/fsimpl/sys/BUILD
+++ b/pkg/sentry/fsimpl/sys/BUILD
@@ -15,6 +15,7 @@ go_library(
         "//pkg/sentry/kernel",
         "//pkg/sentry/kernel/auth",
         "//pkg/sentry/vfs",
+        "//pkg/sentry/vfs/lock",
         "//pkg/syserror",
     ],
 )
diff --git a/pkg/sentry/fsimpl/sys/sys.go b/pkg/sentry/fsimpl/sys/sys.go
index 0af373604..b84463d3a 100644
--- a/pkg/sentry/fsimpl/sys/sys.go
+++ b/pkg/sentry/fsimpl/sys/sys.go
@@ -25,6 +25,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/kernel"
 	"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"
 )
 
@@ -98,8 +99,10 @@ type dir struct {
 	kernfs.InodeNoDynamicLookup
 	kernfs.InodeNotSymlink
 	kernfs.InodeDirectoryNoNewChildren
-
 	kernfs.OrderedChildren
+
+	locks lock.FileLocks
+
 	dentry kernfs.Dentry
 }
 
@@ -121,7 +124,7 @@ func (*dir) SetStat(context.Context, *vfs.Filesystem, *auth.Credentials, vfs.Set
 
 // Open implements kernfs.Inode.Open.
 func (d *dir) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) {
-	fd, err := kernfs.NewGenericDirectoryFD(rp.Mount(), vfsd, &d.OrderedChildren, &opts)
+	fd, err := kernfs.NewGenericDirectoryFD(rp.Mount(), vfsd, &d.OrderedChildren, &d.locks, &opts)
 	if err != nil {
 		return nil, err
 	}
diff --git a/pkg/sentry/fsimpl/timerfd/timerfd.go b/pkg/sentry/fsimpl/timerfd/timerfd.go
index 60c92d626..2dc90d484 100644
--- a/pkg/sentry/fsimpl/timerfd/timerfd.go
+++ b/pkg/sentry/fsimpl/timerfd/timerfd.go
@@ -32,6 +32,7 @@ type TimerFileDescription struct {
 	vfsfd vfs.FileDescription
 	vfs.FileDescriptionDefaultImpl
 	vfs.DentryMetadataFileDescriptionImpl
+	vfs.NoLockFD
 
 	events waiter.Queue
 	timer  *ktime.Timer
diff --git a/pkg/sentry/fsimpl/tmpfs/filesystem.go b/pkg/sentry/fsimpl/tmpfs/filesystem.go
index e801680e8..72399b321 100644
--- a/pkg/sentry/fsimpl/tmpfs/filesystem.go
+++ b/pkg/sentry/fsimpl/tmpfs/filesystem.go
@@ -399,6 +399,7 @@ func (d *dentry) open(ctx context.Context, rp *vfs.ResolvingPath, opts *vfs.Open
 	switch impl := d.inode.impl.(type) {
 	case *regularFile:
 		var fd regularFileFD
+		fd.LockFD.Init(&d.inode.locks)
 		if err := fd.vfsfd.Init(&fd, opts.Flags, rp.Mount(), &d.vfsd, &vfs.FileDescriptionOptions{}); err != nil {
 			return nil, err
 		}
@@ -414,15 +415,16 @@ func (d *dentry) open(ctx context.Context, rp *vfs.ResolvingPath, opts *vfs.Open
 			return nil, syserror.EISDIR
 		}
 		var fd directoryFD
+		fd.LockFD.Init(&d.inode.locks)
 		if err := fd.vfsfd.Init(&fd, opts.Flags, rp.Mount(), &d.vfsd, &vfs.FileDescriptionOptions{}); err != nil {
 			return nil, err
 		}
 		return &fd.vfsfd, nil
 	case *symlink:
-		// Can't open symlinks without O_PATH (which is unimplemented).
+		// TODO(gvisor.dev/issue/2782): Can't open symlinks without O_PATH.
 		return nil, syserror.ELOOP
 	case *namedPipe:
-		return impl.pipe.Open(ctx, rp.Mount(), &d.vfsd, opts.Flags)
+		return impl.pipe.Open(ctx, rp.Mount(), &d.vfsd, opts.Flags, &d.inode.locks)
 	case *deviceFile:
 		return rp.VirtualFilesystem().OpenDeviceSpecialFile(ctx, rp.Mount(), &d.vfsd, impl.kind, impl.major, impl.minor, opts)
 	case *socketFile:
diff --git a/pkg/sentry/fsimpl/tmpfs/regular_file.go b/pkg/sentry/fsimpl/tmpfs/regular_file.go
index 4f2ae04d2..77447b32c 100644
--- a/pkg/sentry/fsimpl/tmpfs/regular_file.go
+++ b/pkg/sentry/fsimpl/tmpfs/regular_file.go
@@ -25,7 +25,6 @@ import (
 	"gvisor.dev/gvisor/pkg/safemem"
 	"gvisor.dev/gvisor/pkg/sentry/fs"
 	"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"
@@ -366,28 +365,6 @@ 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
-}
-
 // ConfigureMMap implements vfs.FileDescriptionImpl.ConfigureMMap.
 func (fd *regularFileFD) ConfigureMMap(ctx context.Context, opts *memmap.MMapOpts) error {
 	file := fd.inode().impl.(*regularFile)
diff --git a/pkg/sentry/fsimpl/tmpfs/tmpfs.go b/pkg/sentry/fsimpl/tmpfs/tmpfs.go
index 7ce1b86c7..71a7522af 100644
--- a/pkg/sentry/fsimpl/tmpfs/tmpfs.go
+++ b/pkg/sentry/fsimpl/tmpfs/tmpfs.go
@@ -36,7 +36,6 @@ import (
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/context"
-	fslock "gvisor.dev/gvisor/pkg/sentry/fs/lock"
 	"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
 	"gvisor.dev/gvisor/pkg/sentry/kernel/time"
 	"gvisor.dev/gvisor/pkg/sentry/pgalloc"
@@ -311,7 +310,6 @@ type inode struct {
 	ctime int64 // nanoseconds
 	mtime int64 // nanoseconds
 
-	// Advisory file locks, which lock at the inode level.
 	locks lock.FileLocks
 
 	// Inotify watches for this inode.
@@ -539,44 +537,6 @@ func (i *inode) setStat(ctx context.Context, creds *auth.Credentials, stat *linu
 	return nil
 }
 
-// TODO(gvisor.dev/issue/1480): support file locking for file types other than regular.
-func (i *inode) lockBSD(uid fslock.UniqueID, t fslock.LockType, block fslock.Blocker) error {
-	switch i.impl.(type) {
-	case *regularFile:
-		return i.locks.LockBSD(uid, t, block)
-	}
-	return syserror.EBADF
-}
-
-// TODO(gvisor.dev/issue/1480): support file locking for file types other than regular.
-func (i *inode) unlockBSD(uid fslock.UniqueID) error {
-	switch i.impl.(type) {
-	case *regularFile:
-		i.locks.UnlockBSD(uid)
-		return nil
-	}
-	return syserror.EBADF
-}
-
-// TODO(gvisor.dev/issue/1480): support file locking for file types other than regular.
-func (i *inode) lockPOSIX(uid fslock.UniqueID, t fslock.LockType, rng fslock.LockRange, block fslock.Blocker) error {
-	switch i.impl.(type) {
-	case *regularFile:
-		return i.locks.LockPOSIX(uid, t, rng, block)
-	}
-	return syserror.EBADF
-}
-
-// TODO(gvisor.dev/issue/1480): support file locking for file types other than regular.
-func (i *inode) unlockPOSIX(uid fslock.UniqueID, rng fslock.LockRange) error {
-	switch i.impl.(type) {
-	case *regularFile:
-		i.locks.UnlockPOSIX(uid, rng)
-		return nil
-	}
-	return syserror.EBADF
-}
-
 // allocatedBlocksForSize returns the number of 512B blocks needed to
 // accommodate the given size in bytes, as appropriate for struct
 // stat::st_blocks and struct statx::stx_blocks. (Note that this 512B block
@@ -708,6 +668,7 @@ func (i *inode) userXattrSupported() bool {
 type fileDescription struct {
 	vfsfd vfs.FileDescription
 	vfs.FileDescriptionDefaultImpl
+	vfs.LockFD
 }
 
 func (fd *fileDescription) filesystem() *filesystem {
diff --git a/pkg/sentry/kernel/fd_table.go b/pkg/sentry/kernel/fd_table.go
index dbfcef0fa..b35afafe3 100644
--- a/pkg/sentry/kernel/fd_table.go
+++ b/pkg/sentry/kernel/fd_table.go
@@ -80,9 +80,6 @@ type FDTable struct {
 	refs.AtomicRefCount
 	k *Kernel
 
-	// uid is a unique identifier.
-	uid uint64
-
 	// mu protects below.
 	mu sync.Mutex `state:"nosave"`
 
@@ -130,7 +127,7 @@ func (f *FDTable) loadDescriptorTable(m map[int32]descriptor) {
 // drop drops the table reference.
 func (f *FDTable) drop(file *fs.File) {
 	// Release locks.
-	file.Dirent.Inode.LockCtx.Posix.UnlockRegion(lock.UniqueID(f.uid), lock.LockRange{0, lock.LockEOF})
+	file.Dirent.Inode.LockCtx.Posix.UnlockRegion(f, lock.LockRange{0, lock.LockEOF})
 
 	// Send inotify events.
 	d := file.Dirent
@@ -164,17 +161,9 @@ func (f *FDTable) dropVFS2(file *vfs.FileDescription) {
 	file.DecRef()
 }
 
-// ID returns a unique identifier for this FDTable.
-func (f *FDTable) ID() uint64 {
-	return f.uid
-}
-
 // NewFDTable allocates a new FDTable that may be used by tasks in k.
 func (k *Kernel) NewFDTable() *FDTable {
-	f := &FDTable{
-		k:   k,
-		uid: atomic.AddUint64(&k.fdMapUids, 1),
-	}
+	f := &FDTable{k: k}
 	f.init()
 	return f
 }
diff --git a/pkg/sentry/kernel/kernel.go b/pkg/sentry/kernel/kernel.go
index 5efeb3767..bcbeb6a39 100644
--- a/pkg/sentry/kernel/kernel.go
+++ b/pkg/sentry/kernel/kernel.go
@@ -194,11 +194,6 @@ type Kernel struct {
 	// cpuClockTickerSetting is protected by runningTasksMu.
 	cpuClockTickerSetting ktime.Setting
 
-	// fdMapUids is an ever-increasing counter for generating FDTable uids.
-	//
-	// fdMapUids is mutable, and is accessed using atomic memory operations.
-	fdMapUids uint64
-
 	// uniqueID is used to generate unique identifiers.
 	//
 	// uniqueID is mutable, and is accessed using atomic memory operations.
diff --git a/pkg/sentry/kernel/pipe/BUILD b/pkg/sentry/kernel/pipe/BUILD
index 7bfa9075a..0db546b98 100644
--- a/pkg/sentry/kernel/pipe/BUILD
+++ b/pkg/sentry/kernel/pipe/BUILD
@@ -27,6 +27,7 @@ go_library(
         "//pkg/sentry/fs",
         "//pkg/sentry/fs/fsutil",
         "//pkg/sentry/vfs",
+        "//pkg/sentry/vfs/lock",
         "//pkg/sync",
         "//pkg/syserror",
         "//pkg/usermem",
diff --git a/pkg/sentry/kernel/pipe/vfs.go b/pkg/sentry/kernel/pipe/vfs.go
index 2602bed72..c0e9ee1f4 100644
--- a/pkg/sentry/kernel/pipe/vfs.go
+++ b/pkg/sentry/kernel/pipe/vfs.go
@@ -21,6 +21,7 @@ import (
 	"gvisor.dev/gvisor/pkg/safemem"
 	"gvisor.dev/gvisor/pkg/sentry/arch"
 	"gvisor.dev/gvisor/pkg/sentry/vfs"
+	"gvisor.dev/gvisor/pkg/sentry/vfs/lock"
 	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 	"gvisor.dev/gvisor/pkg/usermem"
@@ -61,11 +62,13 @@ func NewVFSPipe(isNamed bool, sizeBytes, atomicIOBytes int64) *VFSPipe {
 //
 // Preconditions: statusFlags should not contain an open access mode.
 func (vp *VFSPipe) ReaderWriterPair(mnt *vfs.Mount, vfsd *vfs.Dentry, statusFlags uint32) (*vfs.FileDescription, *vfs.FileDescription) {
-	return vp.newFD(mnt, vfsd, linux.O_RDONLY|statusFlags), vp.newFD(mnt, vfsd, linux.O_WRONLY|statusFlags)
+	// Connected pipes share the same locks.
+	locks := &lock.FileLocks{}
+	return vp.newFD(mnt, vfsd, linux.O_RDONLY|statusFlags, locks), vp.newFD(mnt, vfsd, linux.O_WRONLY|statusFlags, locks)
 }
 
 // Open opens the pipe represented by vp.
-func (vp *VFSPipe) Open(ctx context.Context, mnt *vfs.Mount, vfsd *vfs.Dentry, statusFlags uint32) (*vfs.FileDescription, error) {
+func (vp *VFSPipe) Open(ctx context.Context, mnt *vfs.Mount, vfsd *vfs.Dentry, statusFlags uint32, locks *lock.FileLocks) (*vfs.FileDescription, error) {
 	vp.mu.Lock()
 	defer vp.mu.Unlock()
 
@@ -75,7 +78,7 @@ func (vp *VFSPipe) Open(ctx context.Context, mnt *vfs.Mount, vfsd *vfs.Dentry, s
 		return nil, syserror.EINVAL
 	}
 
-	fd := vp.newFD(mnt, vfsd, statusFlags)
+	fd := vp.newFD(mnt, vfsd, statusFlags, locks)
 
 	// Named pipes have special blocking semantics during open:
 	//
@@ -127,10 +130,11 @@ func (vp *VFSPipe) Open(ctx context.Context, mnt *vfs.Mount, vfsd *vfs.Dentry, s
 }
 
 // Preconditions: vp.mu must be held.
-func (vp *VFSPipe) newFD(mnt *vfs.Mount, vfsd *vfs.Dentry, statusFlags uint32) *vfs.FileDescription {
+func (vp *VFSPipe) newFD(mnt *vfs.Mount, vfsd *vfs.Dentry, statusFlags uint32, locks *lock.FileLocks) *vfs.FileDescription {
 	fd := &VFSPipeFD{
 		pipe: &vp.pipe,
 	}
+	fd.LockFD.Init(locks)
 	fd.vfsfd.Init(fd, statusFlags, mnt, vfsd, &vfs.FileDescriptionOptions{
 		DenyPRead:         true,
 		DenyPWrite:        true,
@@ -159,6 +163,7 @@ type VFSPipeFD struct {
 	vfsfd vfs.FileDescription
 	vfs.FileDescriptionDefaultImpl
 	vfs.DentryMetadataFileDescriptionImpl
+	vfs.LockFD
 
 	pipe *Pipe
 }
diff --git a/pkg/sentry/socket/hostinet/BUILD b/pkg/sentry/socket/hostinet/BUILD
index e82d6cd1e..60c9896fc 100644
--- a/pkg/sentry/socket/hostinet/BUILD
+++ b/pkg/sentry/socket/hostinet/BUILD
@@ -34,6 +34,7 @@ go_library(
         "//pkg/sentry/socket",
         "//pkg/sentry/socket/control",
         "//pkg/sentry/vfs",
+        "//pkg/sentry/vfs/lock",
         "//pkg/syserr",
         "//pkg/syserror",
         "//pkg/tcpip/stack",
diff --git a/pkg/sentry/socket/hostinet/socket_vfs2.go b/pkg/sentry/socket/hostinet/socket_vfs2.go
index 677743113..027add1fd 100644
--- a/pkg/sentry/socket/hostinet/socket_vfs2.go
+++ b/pkg/sentry/socket/hostinet/socket_vfs2.go
@@ -26,6 +26,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/kernel"
 	"gvisor.dev/gvisor/pkg/sentry/socket"
 	"gvisor.dev/gvisor/pkg/sentry/vfs"
+	"gvisor.dev/gvisor/pkg/sentry/vfs/lock"
 	"gvisor.dev/gvisor/pkg/syserr"
 	"gvisor.dev/gvisor/pkg/syserror"
 	"gvisor.dev/gvisor/pkg/usermem"
@@ -35,6 +36,7 @@ import (
 type socketVFS2 struct {
 	vfsfd vfs.FileDescription
 	vfs.FileDescriptionDefaultImpl
+	vfs.LockFD
 
 	// We store metadata for hostinet sockets internally. Technically, we should
 	// access metadata (e.g. through stat, chmod) on the host for correctness,
@@ -59,6 +61,7 @@ func newVFS2Socket(t *kernel.Task, family int, stype linux.SockType, protocol in
 			fd:       fd,
 		},
 	}
+	s.LockFD.Init(&lock.FileLocks{})
 	if err := fdnotifier.AddFD(int32(fd), &s.queue); err != nil {
 		return nil, syserr.FromError(err)
 	}
diff --git a/pkg/sentry/socket/netlink/BUILD b/pkg/sentry/socket/netlink/BUILD
index 7212d8644..420e573c9 100644
--- a/pkg/sentry/socket/netlink/BUILD
+++ b/pkg/sentry/socket/netlink/BUILD
@@ -29,6 +29,7 @@ go_library(
         "//pkg/sentry/socket/unix",
         "//pkg/sentry/socket/unix/transport",
         "//pkg/sentry/vfs",
+        "//pkg/sentry/vfs/lock",
         "//pkg/sync",
         "//pkg/syserr",
         "//pkg/syserror",
diff --git a/pkg/sentry/socket/netlink/socket_vfs2.go b/pkg/sentry/socket/netlink/socket_vfs2.go
index b854bf990..8bfee5193 100644
--- a/pkg/sentry/socket/netlink/socket_vfs2.go
+++ b/pkg/sentry/socket/netlink/socket_vfs2.go
@@ -23,6 +23,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/socket/unix"
 	"gvisor.dev/gvisor/pkg/sentry/socket/unix/transport"
 	"gvisor.dev/gvisor/pkg/sentry/vfs"
+	"gvisor.dev/gvisor/pkg/sentry/vfs/lock"
 	"gvisor.dev/gvisor/pkg/syserr"
 	"gvisor.dev/gvisor/pkg/syserror"
 	"gvisor.dev/gvisor/pkg/tcpip"
@@ -40,6 +41,7 @@ type SocketVFS2 struct {
 	vfsfd vfs.FileDescription
 	vfs.FileDescriptionDefaultImpl
 	vfs.DentryMetadataFileDescriptionImpl
+	vfs.LockFD
 
 	socketOpsCommon
 }
@@ -66,7 +68,7 @@ func NewVFS2(t *kernel.Task, skType linux.SockType, protocol Protocol) (*SocketV
 		return nil, err
 	}
 
-	return &SocketVFS2{
+	fd := &SocketVFS2{
 		socketOpsCommon: socketOpsCommon{
 			ports:          t.Kernel().NetlinkPorts(),
 			protocol:       protocol,
@@ -75,7 +77,9 @@ func NewVFS2(t *kernel.Task, skType linux.SockType, protocol Protocol) (*SocketV
 			connection:     connection,
 			sendBufferSize: defaultSendBufferSize,
 		},
-	}, nil
+	}
+	fd.LockFD.Init(&lock.FileLocks{})
+	return fd, nil
 }
 
 // Readiness implements waiter.Waitable.Readiness.
diff --git a/pkg/sentry/socket/netstack/BUILD b/pkg/sentry/socket/netstack/BUILD
index 8f0f5466e..0f592ecc3 100644
--- a/pkg/sentry/socket/netstack/BUILD
+++ b/pkg/sentry/socket/netstack/BUILD
@@ -37,6 +37,7 @@ go_library(
         "//pkg/sentry/socket/netfilter",
         "//pkg/sentry/unimpl",
         "//pkg/sentry/vfs",
+        "//pkg/sentry/vfs/lock",
         "//pkg/sync",
         "//pkg/syserr",
         "//pkg/syserror",
diff --git a/pkg/sentry/socket/netstack/netstack_vfs2.go b/pkg/sentry/socket/netstack/netstack_vfs2.go
index fcd8013c0..1412a4810 100644
--- a/pkg/sentry/socket/netstack/netstack_vfs2.go
+++ b/pkg/sentry/socket/netstack/netstack_vfs2.go
@@ -25,6 +25,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/socket"
 	"gvisor.dev/gvisor/pkg/sentry/socket/netfilter"
 	"gvisor.dev/gvisor/pkg/sentry/vfs"
+	"gvisor.dev/gvisor/pkg/sentry/vfs/lock"
 	"gvisor.dev/gvisor/pkg/syserr"
 	"gvisor.dev/gvisor/pkg/syserror"
 	"gvisor.dev/gvisor/pkg/tcpip"
@@ -38,6 +39,7 @@ type SocketVFS2 struct {
 	vfsfd vfs.FileDescription
 	vfs.FileDescriptionDefaultImpl
 	vfs.DentryMetadataFileDescriptionImpl
+	vfs.LockFD
 
 	socketOpsCommon
 }
@@ -64,6 +66,7 @@ func NewVFS2(t *kernel.Task, family int, skType linux.SockType, protocol int, qu
 			protocol: protocol,
 		},
 	}
+	s.LockFD.Init(&lock.FileLocks{})
 	vfsfd := &s.vfsfd
 	if err := vfsfd.Init(s, linux.O_RDWR, mnt, d, &vfs.FileDescriptionOptions{
 		DenyPRead:         true,
diff --git a/pkg/sentry/socket/unix/BUILD b/pkg/sentry/socket/unix/BUILD
index de2cc4bdf..7d4cc80fe 100644
--- a/pkg/sentry/socket/unix/BUILD
+++ b/pkg/sentry/socket/unix/BUILD
@@ -29,6 +29,7 @@ go_library(
         "//pkg/sentry/socket/netstack",
         "//pkg/sentry/socket/unix/transport",
         "//pkg/sentry/vfs",
+        "//pkg/sentry/vfs/lock",
         "//pkg/syserr",
         "//pkg/syserror",
         "//pkg/tcpip",
diff --git a/pkg/sentry/socket/unix/unix_vfs2.go b/pkg/sentry/socket/unix/unix_vfs2.go
index 45e109361..8c32371a2 100644
--- a/pkg/sentry/socket/unix/unix_vfs2.go
+++ b/pkg/sentry/socket/unix/unix_vfs2.go
@@ -26,6 +26,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/socket/netstack"
 	"gvisor.dev/gvisor/pkg/sentry/socket/unix/transport"
 	"gvisor.dev/gvisor/pkg/sentry/vfs"
+	"gvisor.dev/gvisor/pkg/sentry/vfs/lock"
 	"gvisor.dev/gvisor/pkg/syserr"
 	"gvisor.dev/gvisor/pkg/syserror"
 	"gvisor.dev/gvisor/pkg/tcpip"
@@ -39,6 +40,7 @@ type SocketVFS2 struct {
 	vfsfd vfs.FileDescription
 	vfs.FileDescriptionDefaultImpl
 	vfs.DentryMetadataFileDescriptionImpl
+	vfs.LockFD
 
 	socketOpsCommon
 }
@@ -51,7 +53,7 @@ func NewSockfsFile(t *kernel.Task, ep transport.Endpoint, stype linux.SockType)
 	mnt := t.Kernel().SocketMount()
 	d := sockfs.NewDentry(t.Credentials(), mnt)
 
-	fd, err := NewFileDescription(ep, stype, linux.O_RDWR, mnt, d)
+	fd, err := NewFileDescription(ep, stype, linux.O_RDWR, mnt, d, &lock.FileLocks{})
 	if err != nil {
 		return nil, syserr.FromError(err)
 	}
@@ -60,7 +62,7 @@ func NewSockfsFile(t *kernel.Task, ep transport.Endpoint, stype linux.SockType)
 
 // NewFileDescription creates and returns a socket file description
 // corresponding to the given mount and dentry.
-func NewFileDescription(ep transport.Endpoint, stype linux.SockType, flags uint32, mnt *vfs.Mount, d *vfs.Dentry) (*vfs.FileDescription, error) {
+func NewFileDescription(ep transport.Endpoint, stype linux.SockType, flags uint32, mnt *vfs.Mount, d *vfs.Dentry, locks *lock.FileLocks) (*vfs.FileDescription, error) {
 	// You can create AF_UNIX, SOCK_RAW sockets. They're the same as
 	// SOCK_DGRAM and don't require CAP_NET_RAW.
 	if stype == linux.SOCK_RAW {
@@ -73,6 +75,7 @@ func NewFileDescription(ep transport.Endpoint, stype linux.SockType, flags uint3
 			stype: stype,
 		},
 	}
+	sock.LockFD.Init(locks)
 	vfsfd := &sock.vfsfd
 	if err := vfsfd.Init(sock, flags, mnt, d, &vfs.FileDescriptionOptions{
 		DenyPRead:         true,
diff --git a/pkg/sentry/syscalls/linux/sys_file.go b/pkg/sentry/syscalls/linux/sys_file.go
index 35a98212a..8347617bd 100644
--- a/pkg/sentry/syscalls/linux/sys_file.go
+++ b/pkg/sentry/syscalls/linux/sys_file.go
@@ -998,9 +998,6 @@ func Fcntl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscall
 			return 0, nil, err
 		}
 
-		// The lock uid is that of the Task's FDTable.
-		lockUniqueID := lock.UniqueID(t.FDTable().ID())
-
 		// These locks don't block; execute the non-blocking operation using the inode's lock
 		// context directly.
 		switch flock.Type {
@@ -1010,12 +1007,12 @@ func Fcntl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscall
 			}
 			if cmd == linux.F_SETLK {
 				// Non-blocking lock, provide a nil lock.Blocker.
-				if !file.Dirent.Inode.LockCtx.Posix.LockRegion(lockUniqueID, lock.ReadLock, rng, nil) {
+				if !file.Dirent.Inode.LockCtx.Posix.LockRegion(t.FDTable(), lock.ReadLock, rng, nil) {
 					return 0, nil, syserror.EAGAIN
 				}
 			} else {
 				// Blocking lock, pass in the task to satisfy the lock.Blocker interface.
-				if !file.Dirent.Inode.LockCtx.Posix.LockRegion(lockUniqueID, lock.ReadLock, rng, t) {
+				if !file.Dirent.Inode.LockCtx.Posix.LockRegion(t.FDTable(), lock.ReadLock, rng, t) {
 					return 0, nil, syserror.EINTR
 				}
 			}
@@ -1026,18 +1023,18 @@ func Fcntl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscall
 			}
 			if cmd == linux.F_SETLK {
 				// Non-blocking lock, provide a nil lock.Blocker.
-				if !file.Dirent.Inode.LockCtx.Posix.LockRegion(lockUniqueID, lock.WriteLock, rng, nil) {
+				if !file.Dirent.Inode.LockCtx.Posix.LockRegion(t.FDTable(), lock.WriteLock, rng, nil) {
 					return 0, nil, syserror.EAGAIN
 				}
 			} else {
 				// Blocking lock, pass in the task to satisfy the lock.Blocker interface.
-				if !file.Dirent.Inode.LockCtx.Posix.LockRegion(lockUniqueID, lock.WriteLock, rng, t) {
+				if !file.Dirent.Inode.LockCtx.Posix.LockRegion(t.FDTable(), lock.WriteLock, rng, t) {
 					return 0, nil, syserror.EINTR
 				}
 			}
 			return 0, nil, nil
 		case linux.F_UNLCK:
-			file.Dirent.Inode.LockCtx.Posix.UnlockRegion(lockUniqueID, rng)
+			file.Dirent.Inode.LockCtx.Posix.UnlockRegion(t.FDTable(), rng)
 			return 0, nil, nil
 		default:
 			return 0, nil, syserror.EINVAL
@@ -2157,22 +2154,6 @@ func Flock(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscall
 	nonblocking := operation&linux.LOCK_NB != 0
 	operation &^= linux.LOCK_NB
 
-	// flock(2):
-	// Locks created by flock() are associated with an open file table entry. This means that
-	// duplicate file descriptors (created by, for example, fork(2) or dup(2)) refer to the
-	// same lock, and this lock may be modified or released using any of these descriptors. Furthermore,
-	// the lock is released either by an explicit LOCK_UN operation on any of these duplicate
-	// descriptors, or when all such descriptors have been closed.
-	//
-	// If a process uses open(2) (or similar) to obtain more than one descriptor for the same file,
-	// these descriptors are treated independently by flock(). An attempt to lock the file using
-	// one of these file descriptors may be denied by a lock that the calling process has already placed via
-	// another descriptor.
-	//
-	// We use the File UniqueID as the lock UniqueID because it needs to reference the same lock across dup(2)
-	// and fork(2).
-	lockUniqueID := lock.UniqueID(file.UniqueID)
-
 	// A BSD style lock spans the entire file.
 	rng := lock.LockRange{
 		Start: 0,
@@ -2183,29 +2164,29 @@ func Flock(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscall
 	case linux.LOCK_EX:
 		if nonblocking {
 			// Since we're nonblocking we pass a nil lock.Blocker implementation.
-			if !file.Dirent.Inode.LockCtx.BSD.LockRegion(lockUniqueID, lock.WriteLock, rng, nil) {
+			if !file.Dirent.Inode.LockCtx.BSD.LockRegion(file, lock.WriteLock, rng, nil) {
 				return 0, nil, syserror.EWOULDBLOCK
 			}
 		} else {
 			// Because we're blocking we will pass the task to satisfy the lock.Blocker interface.
-			if !file.Dirent.Inode.LockCtx.BSD.LockRegion(lockUniqueID, lock.WriteLock, rng, t) {
+			if !file.Dirent.Inode.LockCtx.BSD.LockRegion(file, lock.WriteLock, rng, t) {
 				return 0, nil, syserror.EINTR
 			}
 		}
 	case linux.LOCK_SH:
 		if nonblocking {
 			// Since we're nonblocking we pass a nil lock.Blocker implementation.
-			if !file.Dirent.Inode.LockCtx.BSD.LockRegion(lockUniqueID, lock.ReadLock, rng, nil) {
+			if !file.Dirent.Inode.LockCtx.BSD.LockRegion(file, lock.ReadLock, rng, nil) {
 				return 0, nil, syserror.EWOULDBLOCK
 			}
 		} else {
 			// Because we're blocking we will pass the task to satisfy the lock.Blocker interface.
-			if !file.Dirent.Inode.LockCtx.BSD.LockRegion(lockUniqueID, lock.ReadLock, rng, t) {
+			if !file.Dirent.Inode.LockCtx.BSD.LockRegion(file, lock.ReadLock, rng, t) {
 				return 0, nil, syserror.EINTR
 			}
 		}
 	case linux.LOCK_UN:
-		file.Dirent.Inode.LockCtx.BSD.UnlockRegion(lockUniqueID, rng)
+		file.Dirent.Inode.LockCtx.BSD.UnlockRegion(file, rng)
 	default:
 		// flock(2): EINVAL operation is invalid.
 		return 0, nil, syserror.EINVAL
diff --git a/pkg/sentry/syscalls/linux/vfs2/BUILD b/pkg/sentry/syscalls/linux/vfs2/BUILD
index c0d005247..9f93f4354 100644
--- a/pkg/sentry/syscalls/linux/vfs2/BUILD
+++ b/pkg/sentry/syscalls/linux/vfs2/BUILD
@@ -14,6 +14,7 @@ go_library(
         "getdents.go",
         "inotify.go",
         "ioctl.go",
+        "lock.go",
         "memfd.go",
         "mmap.go",
         "mount.go",
@@ -42,6 +43,7 @@ go_library(
         "//pkg/fspath",
         "//pkg/gohacks",
         "//pkg/sentry/arch",
+        "//pkg/sentry/fs/lock",
         "//pkg/sentry/fsbridge",
         "//pkg/sentry/fsimpl/eventfd",
         "//pkg/sentry/fsimpl/pipefs",
diff --git a/pkg/sentry/syscalls/linux/vfs2/lock.go b/pkg/sentry/syscalls/linux/vfs2/lock.go
new file mode 100644
index 000000000..bf19028c4
--- /dev/null
+++ b/pkg/sentry/syscalls/linux/vfs2/lock.go
@@ -0,0 +1,64 @@
+// Copyright 2020 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package vfs2
+
+import (
+	"gvisor.dev/gvisor/pkg/abi/linux"
+	"gvisor.dev/gvisor/pkg/sentry/arch"
+	"gvisor.dev/gvisor/pkg/sentry/fs/lock"
+	"gvisor.dev/gvisor/pkg/sentry/kernel"
+	"gvisor.dev/gvisor/pkg/syserror"
+)
+
+// Flock implements linux syscall flock(2).
+func Flock(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+	fd := args[0].Int()
+	operation := args[1].Int()
+
+	file := t.GetFileVFS2(fd)
+	if file == nil {
+		// flock(2): EBADF fd is not an open file descriptor.
+		return 0, nil, syserror.EBADF
+	}
+	defer file.DecRef()
+
+	nonblocking := operation&linux.LOCK_NB != 0
+	operation &^= linux.LOCK_NB
+
+	var blocker lock.Blocker
+	if !nonblocking {
+		blocker = t
+	}
+
+	switch operation {
+	case linux.LOCK_EX:
+		if err := file.LockBSD(t, lock.WriteLock, blocker); err != nil {
+			return 0, nil, err
+		}
+	case linux.LOCK_SH:
+		if err := file.LockBSD(t, lock.ReadLock, blocker); err != nil {
+			return 0, nil, err
+		}
+	case linux.LOCK_UN:
+		if err := file.UnlockBSD(t); err != nil {
+			return 0, nil, err
+		}
+	default:
+		// flock(2): EINVAL operation is invalid.
+		return 0, nil, syserror.EINVAL
+	}
+
+	return 0, nil, nil
+}
diff --git a/pkg/sentry/syscalls/linux/vfs2/vfs2.go b/pkg/sentry/syscalls/linux/vfs2/vfs2.go
index 7b6e7571a..954c82f97 100644
--- a/pkg/sentry/syscalls/linux/vfs2/vfs2.go
+++ b/pkg/sentry/syscalls/linux/vfs2/vfs2.go
@@ -62,7 +62,7 @@ func Override() {
 	s.Table[55] = syscalls.Supported("getsockopt", GetSockOpt)
 	s.Table[59] = syscalls.Supported("execve", Execve)
 	s.Table[72] = syscalls.Supported("fcntl", Fcntl)
-	delete(s.Table, 73) // flock
+	s.Table[73] = syscalls.Supported("fcntl", Flock)
 	s.Table[74] = syscalls.Supported("fsync", Fsync)
 	s.Table[75] = syscalls.Supported("fdatasync", Fdatasync)
 	s.Table[76] = syscalls.Supported("truncate", Truncate)
diff --git a/pkg/sentry/vfs/BUILD b/pkg/sentry/vfs/BUILD
index 774cc66cc..16d9f3a28 100644
--- a/pkg/sentry/vfs/BUILD
+++ b/pkg/sentry/vfs/BUILD
@@ -72,6 +72,7 @@ go_library(
         "//pkg/sentry/memmap",
         "//pkg/sentry/socket/unix/transport",
         "//pkg/sentry/uniqueid",
+        "//pkg/sentry/vfs/lock",
         "//pkg/sync",
         "//pkg/syserror",
         "//pkg/usermem",
diff --git a/pkg/sentry/vfs/epoll.go b/pkg/sentry/vfs/epoll.go
index 8297f964b..599c3131c 100644
--- a/pkg/sentry/vfs/epoll.go
+++ b/pkg/sentry/vfs/epoll.go
@@ -31,6 +31,7 @@ type EpollInstance struct {
 	vfsfd FileDescription
 	FileDescriptionDefaultImpl
 	DentryMetadataFileDescriptionImpl
+	NoLockFD
 
 	// q holds waiters on this EpollInstance.
 	q waiter.Queue
diff --git a/pkg/sentry/vfs/file_description.go b/pkg/sentry/vfs/file_description.go
index bb294563d..97b9b18d7 100644
--- a/pkg/sentry/vfs/file_description.go
+++ b/pkg/sentry/vfs/file_description.go
@@ -73,6 +73,8 @@ type FileDescription struct {
 	// writable is analogous to Linux's FMODE_WRITE.
 	writable bool
 
+	usedLockBSD uint32
+
 	// impl is the FileDescriptionImpl associated with this Filesystem. impl is
 	// immutable. This should be the last field in FileDescription.
 	impl FileDescriptionImpl
@@ -175,6 +177,12 @@ func (fd *FileDescription) DecRef() {
 			}
 			ep.interestMu.Unlock()
 		}
+
+		// If BSD locks were used, release any lock that it may have acquired.
+		if atomic.LoadUint32(&fd.usedLockBSD) != 0 {
+			fd.impl.UnlockBSD(context.Background(), fd)
+		}
+
 		// Release implementation resources.
 		fd.impl.Release()
 		if fd.writable {
@@ -420,13 +428,9 @@ type FileDescriptionImpl interface {
 	Removexattr(ctx context.Context, name string) error
 
 	// LockBSD tries to acquire a BSD-style advisory file lock.
-	//
-	// TODO(gvisor.dev/issue/1480): BSD-style file locking
 	LockBSD(ctx context.Context, uid lock.UniqueID, t lock.LockType, block lock.Blocker) error
 
-	// LockBSD releases a BSD-style advisory file lock.
-	//
-	// TODO(gvisor.dev/issue/1480): BSD-style file locking
+	// 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.
@@ -736,3 +740,14 @@ func (fd *FileDescription) InodeID() uint64 {
 func (fd *FileDescription) Msync(ctx context.Context, mr memmap.MappableRange) error {
 	return fd.Sync(ctx)
 }
+
+// LockBSD tries to acquire a BSD-style advisory file lock.
+func (fd *FileDescription) LockBSD(ctx context.Context, lockType lock.LockType, blocker lock.Blocker) error {
+	atomic.StoreUint32(&fd.usedLockBSD, 1)
+	return fd.impl.LockBSD(ctx, fd, lockType, blocker)
+}
+
+// UnlockBSD releases a BSD-style advisory file lock.
+func (fd *FileDescription) UnlockBSD(ctx context.Context) error {
+	return fd.impl.UnlockBSD(ctx, fd)
+}
diff --git a/pkg/sentry/vfs/file_description_impl_util.go b/pkg/sentry/vfs/file_description_impl_util.go
index f4c111926..af7213dfd 100644
--- a/pkg/sentry/vfs/file_description_impl_util.go
+++ b/pkg/sentry/vfs/file_description_impl_util.go
@@ -21,8 +21,9 @@ import (
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/context"
 	"gvisor.dev/gvisor/pkg/sentry/arch"
-	"gvisor.dev/gvisor/pkg/sentry/fs/lock"
+	fslock "gvisor.dev/gvisor/pkg/sentry/fs/lock"
 	"gvisor.dev/gvisor/pkg/sentry/memmap"
+	"gvisor.dev/gvisor/pkg/sentry/vfs/lock"
 	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 	"gvisor.dev/gvisor/pkg/usermem"
@@ -153,26 +154,6 @@ func (FileDescriptionDefaultImpl) Removexattr(ctx context.Context, name string)
 	return syserror.ENOTSUP
 }
 
-// LockBSD implements FileDescriptionImpl.LockBSD.
-func (FileDescriptionDefaultImpl) LockBSD(ctx context.Context, uid lock.UniqueID, t lock.LockType, block lock.Blocker) error {
-	return syserror.EBADF
-}
-
-// UnlockBSD implements FileDescriptionImpl.UnlockBSD.
-func (FileDescriptionDefaultImpl) UnlockBSD(ctx context.Context, uid lock.UniqueID) error {
-	return syserror.EBADF
-}
-
-// LockPOSIX implements FileDescriptionImpl.LockPOSIX.
-func (FileDescriptionDefaultImpl) LockPOSIX(ctx context.Context, uid lock.UniqueID, t lock.LockType, rng lock.LockRange, block lock.Blocker) error {
-	return syserror.EBADF
-}
-
-// UnlockPOSIX implements FileDescriptionImpl.UnlockPOSIX.
-func (FileDescriptionDefaultImpl) UnlockPOSIX(ctx context.Context, uid lock.UniqueID, rng lock.LockRange) error {
-	return syserror.EBADF
-}
-
 // DirectoryFileDescriptionDefaultImpl may be embedded by implementations of
 // FileDescriptionImpl that always represent directories to obtain
 // implementations of non-directory I/O methods that return EISDIR.
@@ -384,3 +365,60 @@ func GenericConfigureMMap(fd *FileDescription, m memmap.Mappable, opts *memmap.M
 	fd.IncRef()
 	return nil
 }
+
+// LockFD may be used by most implementations of FileDescriptionImpl.Lock*
+// functions. Caller must call Init().
+type LockFD struct {
+	locks *lock.FileLocks
+}
+
+// Init initializes fd with FileLocks to use.
+func (fd *LockFD) Init(locks *lock.FileLocks) {
+	fd.locks = locks
+}
+
+// LockBSD implements vfs.FileDescriptionImpl.LockBSD.
+func (fd *LockFD) LockBSD(ctx context.Context, uid fslock.UniqueID, t fslock.LockType, block fslock.Blocker) error {
+	return fd.locks.LockBSD(uid, t, block)
+}
+
+// UnlockBSD implements vfs.FileDescriptionImpl.UnlockBSD.
+func (fd *LockFD) UnlockBSD(ctx context.Context, uid fslock.UniqueID) error {
+	fd.locks.UnlockBSD(uid)
+	return nil
+}
+
+// LockPOSIX implements vfs.FileDescriptionImpl.LockPOSIX.
+func (fd *LockFD) LockPOSIX(ctx context.Context, uid fslock.UniqueID, t fslock.LockType, rng fslock.LockRange, block fslock.Blocker) error {
+	return fd.locks.LockPOSIX(uid, t, rng, block)
+}
+
+// UnlockPOSIX implements vfs.FileDescriptionImpl.UnlockPOSIX.
+func (fd *LockFD) UnlockPOSIX(ctx context.Context, uid fslock.UniqueID, rng fslock.LockRange) error {
+	fd.locks.UnlockPOSIX(uid, rng)
+	return nil
+}
+
+// NoLockFD implements Lock*/Unlock* portion of FileDescriptionImpl interface
+// returning ENOLCK.
+type NoLockFD struct{}
+
+// LockBSD implements vfs.FileDescriptionImpl.LockBSD.
+func (NoLockFD) LockBSD(ctx context.Context, uid fslock.UniqueID, t fslock.LockType, block fslock.Blocker) error {
+	return syserror.ENOLCK
+}
+
+// UnlockBSD implements vfs.FileDescriptionImpl.UnlockBSD.
+func (NoLockFD) UnlockBSD(ctx context.Context, uid fslock.UniqueID) error {
+	return syserror.ENOLCK
+}
+
+// LockPOSIX implements vfs.FileDescriptionImpl.LockPOSIX.
+func (NoLockFD) LockPOSIX(ctx context.Context, uid fslock.UniqueID, t fslock.LockType, rng fslock.LockRange, block fslock.Blocker) error {
+	return syserror.ENOLCK
+}
+
+// UnlockPOSIX implements vfs.FileDescriptionImpl.UnlockPOSIX.
+func (NoLockFD) UnlockPOSIX(ctx context.Context, uid fslock.UniqueID, rng fslock.LockRange) error {
+	return syserror.ENOLCK
+}
diff --git a/pkg/sentry/vfs/file_description_impl_util_test.go b/pkg/sentry/vfs/file_description_impl_util_test.go
index 3a75d4d62..5061f6ac9 100644
--- a/pkg/sentry/vfs/file_description_impl_util_test.go
+++ b/pkg/sentry/vfs/file_description_impl_util_test.go
@@ -33,6 +33,7 @@ import (
 type fileDescription struct {
 	vfsfd FileDescription
 	FileDescriptionDefaultImpl
+	NoLockFD
 }
 
 // genCount contains the number of times its DynamicBytesSource.Generate()
diff --git a/pkg/sentry/vfs/inotify.go b/pkg/sentry/vfs/inotify.go
index 05a3051a4..7fa7d2d0c 100644
--- a/pkg/sentry/vfs/inotify.go
+++ b/pkg/sentry/vfs/inotify.go
@@ -57,6 +57,7 @@ type Inotify struct {
 	vfsfd FileDescription
 	FileDescriptionDefaultImpl
 	DentryMetadataFileDescriptionImpl
+	NoLockFD
 
 	// Unique identifier for this inotify instance. We don't just reuse the
 	// inotify fd because fds can be duped. These should not be exposed to the