Merge release-20200608.0-69-g96519e2c9 (automated)

4 files changed, 61 insertions, 28 deletions

diff --git a/pkg/sentry/vfs/file_description.go b/pkg/sentry/vfs/file_description.go
index 13c48824e..e0538ea53 100644
--- a/pkg/sentry/vfs/file_description.go
+++ b/pkg/sentry/vfs/file_description.go
@@ -438,14 +438,10 @@ type FileDescriptionImpl interface {
 	UnlockBSD(ctx context.Context, uid lock.UniqueID) error
 
 	// LockPOSIX tries to acquire a POSIX-style advisory file lock.
-	//
-	// TODO(gvisor.dev/issue/1480): POSIX-style file locking
-	LockPOSIX(ctx context.Context, uid lock.UniqueID, t lock.LockType, rng lock.LockRange, block lock.Blocker) error
+	LockPOSIX(ctx context.Context, uid lock.UniqueID, t lock.LockType, start, length uint64, whence int16, block lock.Blocker) error
 
 	// UnlockPOSIX releases a POSIX-style advisory file lock.
-	//
-	// TODO(gvisor.dev/issue/1480): POSIX-style file locking
-	UnlockPOSIX(ctx context.Context, uid lock.UniqueID, rng lock.LockRange) error
+	UnlockPOSIX(ctx context.Context, uid lock.UniqueID, start, length uint64, whence int16) error
 }
 
 // Dirent holds the information contained in struct linux_dirent64.
@@ -764,3 +760,13 @@ func (fd *FileDescription) LockBSD(ctx context.Context, lockType lock.LockType,
 func (fd *FileDescription) UnlockBSD(ctx context.Context) error {
 	return fd.impl.UnlockBSD(ctx, fd)
 }
+
+// LockPOSIX locks a POSIX-style file range lock.
+func (fd *FileDescription) LockPOSIX(ctx context.Context, uid lock.UniqueID, t lock.LockType, start, end uint64, whence int16, block lock.Blocker) error {
+	return fd.impl.LockPOSIX(ctx, uid, t, start, end, whence, block)
+}
+
+// UnlockPOSIX unlocks a POSIX-style file range lock.
+func (fd *FileDescription) UnlockPOSIX(ctx context.Context, uid lock.UniqueID, start, end uint64, whence int16) error {
+	return fd.impl.UnlockPOSIX(ctx, uid, start, end, whence)
+}
diff --git a/pkg/sentry/vfs/file_description_impl_util.go b/pkg/sentry/vfs/file_description_impl_util.go
index af7213dfd..1e66997ce 100644
--- a/pkg/sentry/vfs/file_description_impl_util.go
+++ b/pkg/sentry/vfs/file_description_impl_util.go
@@ -23,7 +23,6 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/arch"
 	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"
@@ -369,14 +368,19 @@ func GenericConfigureMMap(fd *FileDescription, m memmap.Mappable, opts *memmap.M
 // LockFD may be used by most implementations of FileDescriptionImpl.Lock*
 // functions. Caller must call Init().
 type LockFD struct {
-	locks *lock.FileLocks
+	locks *FileLocks
 }
 
 // Init initializes fd with FileLocks to use.
-func (fd *LockFD) Init(locks *lock.FileLocks) {
+func (fd *LockFD) Init(locks *FileLocks) {
 	fd.locks = locks
 }
 
+// Locks returns the locks associated with this file.
+func (fd *LockFD) Locks() *FileLocks {
+	return fd.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)
@@ -388,17 +392,6 @@ func (fd *LockFD) UnlockBSD(ctx context.Context, uid fslock.UniqueID) error {
 	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{}
@@ -414,11 +407,11 @@ func (NoLockFD) UnlockBSD(ctx context.Context, uid fslock.UniqueID) error {
 }
 
 // LockPOSIX implements vfs.FileDescriptionImpl.LockPOSIX.
-func (NoLockFD) LockPOSIX(ctx context.Context, uid fslock.UniqueID, t fslock.LockType, rng fslock.LockRange, block fslock.Blocker) error {
+func (NoLockFD) LockPOSIX(ctx context.Context, uid fslock.UniqueID, t fslock.LockType, start, length uint64, whence int16, 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 {
+func (NoLockFD) UnlockPOSIX(ctx context.Context, uid fslock.UniqueID, start, length uint64, whence int16) error {
 	return syserror.ENOLCK
 }
diff --git a/pkg/sentry/vfs/lock/lock.go b/pkg/sentry/vfs/lock.go
index 724dfe743..6c7583a81 100644
--- a/pkg/sentry/vfs/lock/lock.go
+++ b/pkg/sentry/vfs/lock.go
@@ -17,9 +17,11 @@
 //
 // The actual implementations can be found in the lock package under
 // sentry/fs/lock.
-package lock
+package vfs
 
 import (
+	"gvisor.dev/gvisor/pkg/abi/linux"
+	"gvisor.dev/gvisor/pkg/context"
 	fslock "gvisor.dev/gvisor/pkg/sentry/fs/lock"
 	"gvisor.dev/gvisor/pkg/syserror"
 )
@@ -56,7 +58,11 @@ func (fl *FileLocks) UnlockBSD(uid fslock.UniqueID) {
 }
 
 // LockPOSIX tries to acquire a POSIX-style lock on a file region.
-func (fl *FileLocks) LockPOSIX(uid fslock.UniqueID, t fslock.LockType, rng fslock.LockRange, block fslock.Blocker) error {
+func (fl *FileLocks) LockPOSIX(ctx context.Context, fd *FileDescription, uid fslock.UniqueID, t fslock.LockType, start, length uint64, whence int16, block fslock.Blocker) error {
+	rng, err := computeRange(ctx, fd, start, length, whence)
+	if err != nil {
+		return err
+	}
 	if fl.posix.LockRegion(uid, t, rng, block) {
 		return nil
 	}
@@ -67,6 +73,37 @@ func (fl *FileLocks) LockPOSIX(uid fslock.UniqueID, t fslock.LockType, rng fsloc
 //
 // This operation is always successful, even if there did not exist a lock on
 // the requested region held by uid in the first place.
-func (fl *FileLocks) UnlockPOSIX(uid fslock.UniqueID, rng fslock.LockRange) {
+func (fl *FileLocks) UnlockPOSIX(ctx context.Context, fd *FileDescription, uid fslock.UniqueID, start, length uint64, whence int16) error {
+	rng, err := computeRange(ctx, fd, start, length, whence)
+	if err != nil {
+		return err
+	}
 	fl.posix.UnlockRegion(uid, rng)
+	return nil
+}
+
+func computeRange(ctx context.Context, fd *FileDescription, start uint64, length uint64, whence int16) (fslock.LockRange, error) {
+	var off int64
+	switch whence {
+	case linux.SEEK_SET:
+		off = 0
+	case linux.SEEK_CUR:
+		// Note that Linux does not hold any mutexes while retrieving the file
+		// offset, see fs/locks.c:flock_to_posix_lock and fs/locks.c:fcntl_setlk.
+		curOff, err := fd.Seek(ctx, 0, linux.SEEK_CUR)
+		if err != nil {
+			return fslock.LockRange{}, err
+		}
+		off = curOff
+	case linux.SEEK_END:
+		stat, err := fd.Stat(ctx, StatOptions{Mask: linux.STATX_SIZE})
+		if err != nil {
+			return fslock.LockRange{}, err
+		}
+		off = int64(stat.Size)
+	default:
+		return fslock.LockRange{}, syserror.EINVAL
+	}
+
+	return fslock.ComputeRange(int64(start), int64(length), off)
 }
diff --git a/pkg/sentry/vfs/lock/lock_state_autogen.go b/pkg/sentry/vfs/lock/lock_state_autogen.go
deleted file mode 100644
index 682254baf..000000000
--- a/pkg/sentry/vfs/lock/lock_state_autogen.go
+++ /dev/null
@@ -1,3 +0,0 @@
-// automatically generated by stateify.
-
-package lock