Implement fallocate(2)

Closes #225

PiperOrigin-RevId: 247508791
Change-Id: I04f47cf2770b30043e5a272aba4ba6e11d0476cc

1 files changed, 25 insertions, 0 deletions

diff --git a/pkg/sentry/fs/fsutil/inode.go b/pkg/sentry/fs/fsutil/inode.go
index b6366d906..151be1d0d 100644
--- a/pkg/sentry/fs/fsutil/inode.go
+++ b/pkg/sentry/fs/fsutil/inode.go
@@ -34,6 +34,7 @@ type SimpleFileInode struct {
 	InodeNoExtendedAttributes `state:"nosave"`
 	InodeNoopRelease          `state:"nosave"`
 	InodeNoopWriteOut         `state:"nosave"`
+	InodeNotAllocatable       `state:"nosave"`
 	InodeNotDirectory         `state:"nosave"`
 	InodeNotMappable          `state:"nosave"`
 	InodeNotOpenable          `state:"nosave"`
@@ -61,6 +62,7 @@ type NoReadWriteFileInode struct {
 	InodeNoExtendedAttributes `state:"nosave"`
 	InodeNoopRelease          `state:"nosave"`
 	InodeNoopWriteOut         `state:"nosave"`
+	InodeNotAllocatable       `state:"nosave"`
 	InodeNotDirectory         `state:"nosave"`
 	InodeNotMappable          `state:"nosave"`
 	InodeNotSocket            `state:"nosave"`
@@ -465,3 +467,26 @@ func (InodeDenyWriteChecker) Check(ctx context.Context, inode *fs.Inode, p fs.Pe
 	}
 	return fs.ContextCanAccessFile(ctx, inode, p)
 }
+
+//InodeNotAllocatable can be used by Inodes that do not support Allocate().
+type InodeNotAllocatable struct{}
+
+func (InodeNotAllocatable) Allocate(_ context.Context, _ *fs.Inode, _, _ int64) error {
+	return syserror.EOPNOTSUPP
+}
+
+// InodeNoopAllocate implements fs.InodeOperations.Allocate as a noop.
+type InodeNoopAllocate struct{}
+
+// Allocate implements fs.InodeOperations.Allocate.
+func (InodeNoopAllocate) Allocate(_ context.Context, _ *fs.Inode, _, _ int64) error {
+	return nil
+}
+
+// InodeIsDirAllocate implements fs.InodeOperations.Allocate for directories.
+type InodeIsDirAllocate struct{}
+
+// Allocate implements fs.InodeOperations.Allocate.
+func (InodeIsDirAllocate) Allocate(_ context.Context, _ *fs.Inode, _, _ int64) error {
+	return syserror.EISDIR
+}