ext: testing environment setup with VFS2 support.

PiperOrigin-RevId: 259835948

4 files changed, 6 insertions, 5 deletions

diff --git a/pkg/sentry/fs/ext/disklayout/dirent_old.go b/pkg/sentry/fs/ext/disklayout/dirent_old.go
index 2e0f9c812..6fff12a6e 100644
--- a/pkg/sentry/fs/ext/disklayout/dirent_old.go
+++ b/pkg/sentry/fs/ext/disklayout/dirent_old.go
@@ -17,8 +17,7 @@ package disklayout
 import "gvisor.dev/gvisor/pkg/sentry/fs"
 
 // DirentOld represents the old directory entry struct which does not contain
-// the file type. This emulates Linux's ext4_dir_entry struct. This is used in
-// ext2, ext3 and sometimes in ext4.
+// the file type. This emulates Linux's ext4_dir_entry struct.
 //
 // Note: This struct can be of variable size on disk. The one described below
 // is of maximum size and the FileName beyond NameLength bytes might contain
diff --git a/pkg/sentry/fs/ext/disklayout/superblock_32.go b/pkg/sentry/fs/ext/disklayout/superblock_32.go
index 587e4afaa..53e515fd3 100644
--- a/pkg/sentry/fs/ext/disklayout/superblock_32.go
+++ b/pkg/sentry/fs/ext/disklayout/superblock_32.go
@@ -15,7 +15,8 @@
 package disklayout
 
 // SuperBlock32Bit implements SuperBlock and represents the 32-bit version of
-// the ext4_super_block struct in fs/ext4/ext4.h.
+// the ext4_super_block struct in fs/ext4/ext4.h. Should be used only if
+// RevLevel = DynamicRev and 64-bit feature is disabled.
 type SuperBlock32Bit struct {
 	// We embed the old superblock struct here because the 32-bit version is just
 	// an extension of the old version.
diff --git a/pkg/sentry/fs/ext/disklayout/superblock_64.go b/pkg/sentry/fs/ext/disklayout/superblock_64.go
index a2c2278fb..7c1053fb4 100644
--- a/pkg/sentry/fs/ext/disklayout/superblock_64.go
+++ b/pkg/sentry/fs/ext/disklayout/superblock_64.go
@@ -17,7 +17,8 @@ package disklayout
 // SuperBlock64Bit implements SuperBlock and represents the 64-bit version of
 // the ext4_super_block struct in fs/ext4/ext4.h. This sums up to be exactly
 // 1024 bytes (smallest possible block size) and hence the superblock always
-// fits in no more than one data block.
+// fits in no more than one data block. Should only be used when the 64-bit
+// feature is set.
 type SuperBlock64Bit struct {
 	// We embed the 32-bit struct here because 64-bit version is just an extension
 	// of the 32-bit version.
diff --git a/pkg/sentry/fs/ext/disklayout/superblock_old.go b/pkg/sentry/fs/ext/disklayout/superblock_old.go
index 5a64aaaa1..9221e0251 100644
--- a/pkg/sentry/fs/ext/disklayout/superblock_old.go
+++ b/pkg/sentry/fs/ext/disklayout/superblock_old.go
@@ -15,7 +15,7 @@
 package disklayout
 
 // SuperBlockOld implements SuperBlock and represents the old version of the
-// superblock struct in ext2 and ext3 systems.
+// superblock struct. Should be used only if RevLevel = OldRev.
 type SuperBlockOld struct {
 	InodesCountRaw      uint32
 	BlocksCountLo       uint32