Merge branch 'master' into pr_lazy_fpsimd_2

1 files changed, 56 insertions, 6 deletions

diff --git a/pkg/sentry/fsimpl/tmpfs/tmpfs.go b/pkg/sentry/fsimpl/tmpfs/tmpfs.go
index 88dbd6e35..521206305 100644
--- a/pkg/sentry/fsimpl/tmpfs/tmpfs.go
+++ b/pkg/sentry/fsimpl/tmpfs/tmpfs.go
@@ -18,9 +18,10 @@
 // Lock order:
 //
 // filesystem.mu
-//   regularFileFD.offMu
-//     regularFile.mu
 //   inode.mu
+//     regularFileFD.offMu
+//       regularFile.mapsMu
+//         regularFile.dataMu
 package tmpfs
 
 import (
@@ -30,14 +31,19 @@ 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"
 	"gvisor.dev/gvisor/pkg/sentry/vfs"
+	"gvisor.dev/gvisor/pkg/sentry/vfs/lock"
 	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 )
 
+// Name is the default filesystem name.
+const Name = "tmpfs"
+
 // FilesystemType implements vfs.FilesystemType.
 type FilesystemType struct{}
 
@@ -153,6 +159,9 @@ type inode struct {
 	rdevMajor uint32
 	rdevMinor uint32
 
+	// Advisory file locks, which lock at the inode level.
+	locks lock.FileLocks
+
 	impl interface{} // immutable
 }
 
@@ -218,12 +227,15 @@ func (i *inode) tryIncRef() bool {
 
 func (i *inode) decRef() {
 	if refs := atomic.AddInt64(&i.refs, -1); refs == 0 {
-		// This is unnecessary; it's mostly to simulate what tmpfs would do.
 		if regFile, ok := i.impl.(*regularFile); ok {
-			regFile.mu.Lock()
+			// Hold inode.mu and regFile.dataMu while mutating
+			// size.
+			i.mu.Lock()
+			regFile.dataMu.Lock()
 			regFile.data.DropAll(regFile.memFile)
 			atomic.StoreUint64(&regFile.size, 0)
-			regFile.mu.Unlock()
+			regFile.dataMu.Unlock()
+			i.mu.Unlock()
 		}
 	} else if refs < 0 {
 		panic("tmpfs.inode.decRef() called without holding a reference")
@@ -312,7 +324,7 @@ func (i *inode) setStat(stat linux.Statx) error {
 	if mask&linux.STATX_SIZE != 0 {
 		switch impl := i.impl.(type) {
 		case *regularFile:
-			updated, err := impl.truncate(stat.Size)
+			updated, err := impl.truncateLocked(stat.Size)
 			if err != nil {
 				return err
 			}
@@ -352,6 +364,44 @@ func (i *inode) setStat(stat linux.Statx) error {
 	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