I spent some time over the last couple of days trying to make
libparted detect Ext4 filesystems [1]. Here ([2] and below) is a very
preliminary 'git diff' against the current Git master. I have not yet
tested it extensively, but I just wanted to know whether I am on the
right track or not.
diff --git a/libparted/fs/ext2/ext2_fs.h b/libparted/fs/ext2/ext2_fs.h
index 713cc21..08d0c38 100644
--- a/libparted/fs/ext2/ext2_fs.h
+++ b/libparted/fs/ext2/ext2_fs.h
@@ -59,6 +59,8 @@
#define EXT2_FEATURE_INCOMPAT_FILETYPE 0x0002
#define EXT3_FEATURE_INCOMPAT_RECOVER 0x0004
+#define EXT4_FEATURE_INCOMPAT_EXTENTS 0x0040
+#define EXT4_FEATURE_INCOMPAT_64BIT 0x0080
/*
* Special inodes numbers
diff --git a/libparted/fs/ext2/interface.c b/libparted/fs/ext2/interface.c
index 8935840..48ee61a 100644
--- a/libparted/fs/ext2/interface.c
+++ b/libparted/fs/ext2/interface.c
@@ -32,7 +32,7 @@ static PedFileSystemType _ext3_type;
struct ext2_dev_handle*
ext2_make_dev_handle_from_parted_geometry(PedGeometry* geom);
static PedGeometry*
-_ext2_generic_probe (PedGeometry* geom, int expect_ext3)
+_ext2_generic_probe (PedGeometry* geom, int expect_ext_ver)
{
struct ext2_super_block sb;
@@ -46,10 +46,23 @@ _ext2_generic_probe (PedGeometry* geom, int expect_ext3)
PedSector group_nr = EXT2_SUPER_BLOCK_GROUP_NR(sb);
PedSector first_data_block = EXT2_SUPER_FIRST_DATA_BLOCK(sb);
int version = EXT2_SUPER_REV_LEVEL(sb);
- int is_ext3 = (EXT2_SUPER_FEATURE_COMPAT(sb)
- & EXT3_FEATURE_COMPAT_HAS_JOURNAL) != 0;
-
- if (expect_ext3 != is_ext3)
+ int is_ext3 = 0;
+ int is_ext4 = 0;
+
+ is_ext3 = (EXT2_SUPER_FEATURE_COMPAT (sb)
+ & EXT3_FEATURE_COMPAT_HAS_JOURNAL) != 0;
+ if (is_ext3) {
+ is_ext4 = is_ext3 && ((EXT2_SUPER_FEATURE_INCOMPAT (sb)
+ & EXT4_FEATURE_INCOMPAT_EXTENTS) != 0);
+ if (is_ext4)
+ is_ext3 = 0;
+ }
+
+ if (expect_ext_ver == 2 && (is_ext3 || is_ext4))
+ return NULL;
+ if (expect_ext_ver == 3 && !is_ext3)
+ return NULL;
+ else if (expect_ext_ver == 4 && !is_ext4)
return NULL;
if (version > 0 && group_nr > 0) {
@@ -64,7 +77,8 @@ _ext2_generic_probe (PedGeometry* geom, int expect_ext3)
return NULL;
ped_geometry_init (&probe_geom, geom->dev,
start, block_count * block_size);
- return _ext2_generic_probe (&probe_geom, expect_ext3);
+ return _ext2_generic_probe (&probe_geom,
+ expect_ext_ver);
} else {
return ped_geometry_new (geom->dev, geom->start,
block_count * block_size);
@@ -76,13 +90,19 @@ _ext2_generic_probe (PedGeometry* geom, int expect_ext3)
static PedGeometry*
_ext2_probe (PedGeometry* geom)
{
- return _ext2_generic_probe (geom, 0);
+ return _ext2_generic_probe (geom, 2);
}
static PedGeometry*
_ext3_probe (PedGeometry* geom)
{
- return _ext2_generic_probe (geom, 1);
+ return _ext2_generic_probe (geom, 3);
+}
+
+static PedGeometry*
+_ext4_probe (PedGeometry* geom)
+{
+ return _ext2_generic_probe (geom, 4);
}
#ifndef DISCOVER_ONLY
@@ -323,6 +343,20 @@ static PedFileSystemOps _ext3_ops = {
#endif /* !DISCOVER_ONLY */
};
+static PedFileSystemOps _ext4_ops = {
+ probe: _ext4_probe,
+ clobber: NULL,
+ open: NULL,
+ create: NULL,
+ close: NULL,
+ check: NULL,
+ resize: NULL,
+ copy: NULL,
+ get_create_constraint: NULL,
+ get_copy_constraint: NULL,
+ get_resize_constraint: NULL
+};
+
#define EXT23_BLOCK_SIZES ((int[6]){512, 1024, 2048, 4096, 8192, 0})
static PedFileSystemType _ext2_type = {
@@ -339,14 +373,23 @@ static PedFileSystemType _ext3_type = {
block_sizes: EXT23_BLOCK_SIZES
};
+static PedFileSystemType _ext4_type = {
+ next: NULL,
+ ops: &_ext4_ops,
+ name: "ext4",
+ block_sizes: EXT23_BLOCK_SIZES
+};
+
void ped_file_system_ext2_init ()
{
ped_file_system_type_register (&_ext2_type);
ped_file_system_type_register (&_ext3_type);
+ ped_file_system_type_register (&_ext4_type);
}
void ped_file_system_ext2_done ()
{
ped_file_system_type_unregister (&_ext2_type);
ped_file_system_type_unregister (&_ext3_type);
+ ped_file_system_type_unregister (&_ext4_type);
}
Comments?
Happy hacking,
Debarshi
----
[1] http://parted.alioth.debian.org/cgi-bin/trac.cgi/ticket/188
[2] http://rishi.fedorapeople.org/gnu/parted-ext4-probe.patch
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