Module: Ext4

Included in:: FileObject

Defined in:: lib/fs/MiqFS/modules/Ext4.rb,
lib/fs/ext4/inode.rb,
lib/fs/ext4/extent.rb,
lib/fs/ext4/directory.rb,
lib/fs/ext4/superblock.rb,
lib/fs/ext4/alloc_bitmap.rb,
lib/fs/ext4/extent_index.rb,
lib/fs/ext4/extent_header.rb,
lib/fs/ext4/ex_attrib_name.rb,
lib/fs/ext4/directory_entry.rb,
lib/fs/ext4/hash_tree_entry.rb,
lib/fs/ext4/posix_acl_entry.rb,
lib/fs/ext4/ex_attrib_header.rb,
lib/fs/ext4/hash_tree_header.rb,
lib/fs/ext4/posix_acl_header.rb,
lib/fs/ext4/group_descriptor_entry.rb,
lib/fs/ext4/group_descriptor_table.rb

Overview

Ext4 file system interface to MiqFS.

Defined Under Namespace

Classes: AllocBitmap, Directory, DirectoryEntry, ExAttribHeader, ExAttribName, Extent, ExtentHeader, ExtentIndex, FileObject, GroupDescriptorEntry, GroupDescriptorTable, HashTreeEntry, HashTreeHeader, Inode, PosixAclEntry, PosixAclHeader, Superblock

Constant Summary collapse

INODE = //////////////////////////////////////////////////////////////////////////// // Data definitions.

BinaryStruct.new([
  'S',  'file_mode',    # File mode (type and permission), see PF_ DF_ & FM_ below.
  'S',  'uid_lo',       # Lower 16-bits of user id.
  'L',  'size_lo',      # Lower 32-bits of size in bytes.
  'L',  'atime',        # Last access       time.
  'L',  'ctime',        # Last change       time.
  'L',  'mtime',        # Last modification time.
  'L',  'dtime',        # Time deleted.
  'S',  'gid_lo',       # Lower 16-bits of group id.
  'S',  'link_count',   # Link count.
  'L',  'blocks_lo',    # Lower 32-bits of Block count.
  'L',  'flags',        # Inode flags, see IF_ below.
  'L',  'version',      # Version.
  'a60', 'data',         # 60 bytes deciphered into data (symlink, indirect pointer, or extents)
  'L',  'gen_num',      # Generation number (NFS).
  'L',  'file_acl_lo',  # Lower 32-bits of File.
  'L',  'size_hi',      # Upper 32-bits of size in bytes or directory ACL.
  'L',  'obso_faddr',   # Obsoleted fragment address.
  'S',  'blocks_hi',    # Upper 16-bits of Block count.
  'S',  'file_acl_hi',  # Upper 16-bits of File ACL.
  'S',  'uid_hi',       # Upper 16-bits of user id.
  'S',  'gid_hi',       # Upper 16-bits of group id.
  'L',  'reserved2',    # Unused.
  'S',  'extra_isize',  #
  'S',  'pad1',         #
  'L',  'ctime_extra',  # extra Change             time (nsec << 2 | epoch)
  'L',  'mtime_extra',  # extra Modification       time (nsec << 2 | epoch)
  'L',  'atime_extra',  # extra Access             time (nsec << 2 | epoch)
  'L',  'crtime',       # File Creation time
  'L',  'crtime_extra', # extra File Creation Time time (nsec << 2 | epoch)
  'L',  'version_hi',   # Upper 32-bits of version (for 64-bit version)
])

SIZEOF_INODE =

INODE.size

SYM_LNK_SIZE =

MAX_READ =

4294967296

DEFAULT_BLOCK_SIZE =

EXTENT = //////////////////////////////////////////////////////////////////////////// // Data definitions.

BinaryStruct.new([
  'L',  'block',      # first logical block extent covers
  'S',  'length',     # number of blocks covered by extent
  'S',  'start_hi',   # high 16 bits of physical block
  'L',  'start_lo',   # low  32 bits of physical block
])

SIZEOF_EXTENT =

EXTENT.size

SUPERBLOCK = //////////////////////////////////////////////////////////////////////////// // Data definitions. Linux 2.6.2 from Fedora Core 6.

BinaryStruct.new([
  'L',  'num_inodes',         # Number of inodes in file system.
  'L',  'num_blocks',         # Number of blocks in file system.
  'L',  'reserved_blocks',    # Number of reserved blocks to prevent file system from filling up.
  'L',  'unallocated_blocks', # Number of unallocated blocks.
  'L',  'unallocated_inodes', # Number of unallocated inodes.
  'L',  'block_group_zero',   # Block where block group 0 starts.
  'L',  'block_size',         # Block size (saved as num bits to shift 1024 left).
  'L',  'fragment_size',      # Fragment size (saved as num bits to shift 1024 left).
  'L',  'blocks_in_group',    # Number of blocks in each block group.
  'L',  'fragments_in_group', # Number of fragments in each block group.
  'L',  'inodes_in_group',    # Number of inodes in each block group.
  'L',  'last_mount_time',    # Time FS was last mounted.
  'L',  'last_write_time',    # Time FS was last written to.
  'S',  'mount_count',        # Current mount count.
  'S',  'max_mount_count',    # Maximum mount count.
  'S',  'signature',          # Always 0xef53
  'S',  'fs_state',           # File System State: see FSS_ below.
  'S',  'err_method',         # Error Handling Method: see EHM_ below.
  'S',  'ver_minor',          # Minor version number.
  'L',  'last_check_time',    # Last consistency check time.
  'L',  'forced_check_int',   # Forced check interval.
  'L',  'creator_os',         # Creator OS: see CO_ below.
  'L',  'ver_major',          # Major version: see MV_ below.
  'S',  'uid_res_blocks',     # UID that can use reserved blocks.
  'S',  'gid_res_blocks',     # GID that can uss reserved blocks.
  # Begin dynamic version fields
  'L',  'first_inode',        # First non-reserved inode in file system.
  'S',  'inode_size',         # Size of each inode.
  'S',  'block_group',        # Block group that this superblock is part of (if backup copy).
  'L',  'compat_flags',       # Compatible feature flags (see CFF_ below).
  'L',  'incompat_flags',     # Incompatible feature flags (see ICF_ below).
  'L',  'ro_flags',           # Read Only feature flags (see ROF_ below).
  'a16',  'fs_id',            # File system ID (UUID or GUID).
  'a16',  'vol_name',         # Volume name.
  'a64',  'last_mnt_path',    # Path where last mounted.
  'L',  'algo_use_bmp',       # Algorithm usage bitmap.
  # Performance hints
  'C',  'file_prealloc_blks', # Blocks to preallocate for files.
  'C',  'dir_prealloc_blks',  # Blocks to preallocate for directories.
  'S',  'unused1',            # Unused.
  # Journal support
  'a16',  'jrnl_id',          # Joural ID (UUID or GUID).
  'L',  'jrnl_inode',         # Journal inode.
  'L',  'jrnl_device',        # Journal device.
  'L',  'orphan_head',        # Head of orphan inode list.
  'a16',  'hash_seed',        # HTREE hash seed. This is actually L4 (__u32 s_hash_seed[4])
  'C',  'hash_ver',           # Default hash version.
  'C',  'unused2',
  'S',  'group_desc_size',    # Group descriptor size.
  'L',  'mount_opts',         # Default mount options.
  'L',  'first_meta_blk_grp', # First metablock block group.
  'a360', 'reserved'          # Unused.
])

SUPERBLOCK_SIG =

0xef53

SUPERBLOCK_OFFSET =

SUPERBLOCK_SIZE =

GDE_SIZE = default group descriptor size.

INODE_SIZE = Default inode size.

EXTENT_INDEX = //////////////////////////////////////////////////////////////////////////// // Data definitions.

BinaryStruct.new([
  'L',  'block',      # index covers logical blocks from 'block'
  'L',  'leaf_lo',    # low  32 bits of physical block of the next level. leaf or next index could be there
  'S',  'leaf_hi',    # high 16 bits of physical block
  'S',  'unused',     #
])

SIZEOF_EXTENT_INDEX =

EXTENT_INDEX.size

DEF_CACHE_SIZE = Default directory cache size.

EXTENT_HEADER = //////////////////////////////////////////////////////////////////////////// // Data definitions.

BinaryStruct.new([
  'S',  'magic',      # Signature.
  'S',  'entries',    # Number of Valid Entries
  'S',  'max',        # Capacity of Store in Entries
  'S',  'depth',      # Has tree real underlying blocks?
  'L',  'generation', # Generation of the tree.
])

SIZEOF_EXTENT_HEADER =

EXTENT_HEADER.size

EX_ATTRIB_NAME = //////////////////////////////////////////////////////////////////////////// // Data definitions.

[
  'C',  'name_len',       # Length of name
  'C',  'type',           # Type of attribute, see AT_ below.
  'S',  'offset_to_val',  # Offset to value.
  'L',  'blk_loc',        # Block location of value (not used).
  'L',  'size_of_val',    # Size in bytes of value.
  'L',  'hash_of_val',    # Hash of value.
]

DIR_ENTRY_ORIGINAL = //////////////////////////////////////////////////////////////////////////// // Data definitions.

BinaryStruct.new([
  'L',  'inode_val',  # Inode address of metadata.
  'S',  'entry_len',  # Length of entry.
  'S',  'name_len',   # Length of name.
])

SIZEOF_DIR_ENTRY_ORIGINAL = Here follows the name in ASCII.

DIR_ENTRY_ORIGINAL.size

DIR_ENTRY_NEW =

BinaryStruct.new([
  'L',  'inode_val',  # Inode address of metadata.
  'S',  'entry_len',  # Length of entry.
  'C',  'name_len',   # Length of name.
  'C',  'file_type',  # Type of file (see FT_ below).
])

SIZEOF_DIR_ENTRY_NEW = Here follows the name in ASCII.

DIR_ENTRY_NEW.size

HASH_TREE_ENTRY_FIRST = //////////////////////////////////////////////////////////////////////////// // Data definitions.

BinaryStruct.new([
  'S',  'max_descriptors',  # Maximum number of node descriptors.
  'S',  'cur_descriptors',  # Current number of node descriptors.
  'L',  'first_node',       # Block address of first node.
])

SIZEOF_HASH_TREE_ENTRY_FIRST =

HASH_TREE_ENTRY_FIRST.size

HASH_TREE_ENTRY_NEXT =

BinaryStruct.new([
  'L',  'min_hash',   # Minimum hash value in node.
  'L',  'next_node',  # Block address of next node.
])

SIZEOF_HASH_TREE_ENTRY_NEXT =

HASH_TREE_ENTRY_NEXT.size

SIZEOF_HASH_TREE_ENTRY =

SIZEOF_HASH_TREE_ENTRY_NEXT

POSIX_ACL_ENTRY = //////////////////////////////////////////////////////////////////////////// // Data definitions.

[
  'S',  'type',         # Entry type, see ET_ below.
  'S',  'permissions',  # Permissions, see EP_ below.
  'L',  'u_g_id',       # User / Group id (not defined for some types).
]

EX_ATTRIB_HEADER = //////////////////////////////////////////////////////////////////////////// // Data definitions.

[
  'L',  'signature',  # Always 0xea020000
  'L',  'ref_count',
  'L',  'num_blks',
  'L',  'hash',
]

HASH_TREE_HEADER = //////////////////////////////////////////////////////////////////////////// // Data definitions.

BinaryStruct.new([
  'L',  'unused1',    # Unused.
  'C',  'hash_ver',   # Hash version.
  'C',  'length',     # Length of this structure.
  'C',  'leaf_level', # Levels of leaves.
  'C',  'unused2',    # Unused.
])

SIZEOF_HASH_TREE_HEADER =

HASH_TREE_HEADER.size

POSIX_ACL_HEADER = //////////////////////////////////////////////////////////////////////////// // Data definitions.

[
  'L',  'version',  # Always 1, or 1 is all that's supported.
]

GDE = //////////////////////////////////////////////////////////////////////////// // Data definitions.

BinaryStruct.new([
  'L',  'blk_bmp',        # Starting block address of block bitmap.
  'L',  'inode_bmp',      # Starting block address of inode bitmap.
  'L',  'inode_table',    # Starting block address of inode table.
  'S',  'unalloc_blks',   # Number of unallocated blocks in group.
  'S',  'unalloc_inodes', # Number of unallocated inodes in group.
  'S',  'num_dirs',       # Number of directories in group.
  'a14',  'unused1',      # Unused.
])

Instance Attribute Summary collapse

#cache_hits ⇒ Object

Members (these become members of an MiqFS instance).
#dir_cache ⇒ Object

Members (these become members of an MiqFS instance).
#entry_cache ⇒ Object

Members (these become members of an MiqFS instance).
#rootDir ⇒ Object

Members (these become members of an MiqFS instance).
#superblock ⇒ Object

Members (these become members of an MiqFS instance).