freebsd-dev/sys/fs/ext2fs/ext2_dinode.h
Pedro F. Giffuni d7511a40a7 Add read-only support for extents in ext2fs.
Basic support for extents was implemented by Zheng Liu as part
of his Google Summer of Code in 2010. This support is read-only
at this time.

In addition to extents we also support the huge_file extension
for read-only purposes. This works nicely with the additional
support for birthtime/nanosec timestamps and dir_index that
have been added lately.

The implementation may not work for all ext4 filesystems as
it doesn't support some features that are being enabled by
default on recent linux like flex_bg. Nevertheless, the feature
should be very useful for migration or simple access in
filesystems that have been converted from ext2/3 or don't use
incompatible features.

Special thanks to Zheng Liu for his dedication and continued
work to support ext2 in FreeBSD.

Submitted by:	Zheng Liu (lz@)
Reviewed by:	Mike Ma, Christoph Mallon (previous version)
Sponsored by:	Google Inc.
MFC after:	3 weeks
2013-08-12 21:34:48 +00:00

134 lines
5.6 KiB
C

/*-
* Copyright (c) 2009 Aditya Sarawgi
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#ifndef _FS_EXT2FS_EXT2_DINODE_H_
#define _FS_EXT2FS_EXT2_DINODE_H_
/*
* Special inode numbers
* The root inode is the root of the file system. Inode 0 can't be used for
* normal purposes and bad blocks are normally linked to inode 1, thus
* the root inode is 2.
* Inode 3 to 10 are reserved in ext2fs.
*/
#define EXT2_BADBLKINO ((ino_t)1)
#define EXT2_ROOTINO ((ino_t)2)
#define EXT2_ACLIDXINO ((ino_t)3)
#define EXT2_ACLDATAINO ((ino_t)4)
#define EXT2_BOOTLOADERINO ((ino_t)5)
#define EXT2_UNDELDIRINO ((ino_t)6)
#define EXT2_RESIZEINO ((ino_t)7)
#define EXT2_JOURNALINO ((ino_t)8)
#define EXT2_FIRSTINO ((ino_t)11)
/*
* Inode flags
* The current implementation uses only EXT2_IMMUTABLE and EXT2_APPEND flags
*/
#define EXT2_SECRM 0x00000001 /* Secure deletion */
#define EXT2_UNRM 0x00000002 /* Undelete */
#define EXT2_COMPR 0x00000004 /* Compress file */
#define EXT2_SYNC 0x00000008 /* Synchronous updates */
#define EXT2_IMMUTABLE 0x00000010 /* Immutable file */
#define EXT2_APPEND 0x00000020 /* writes to file may only append */
#define EXT2_NODUMP 0x00000040 /* do not dump file */
#define EXT2_NOATIME 0x00000080 /* do not update atime */
#define EXT4_INDEX 0x00001000 /* hash-indexed directory */
#define EXT4_IMAGIC 0x00002000 /* AFS directory */
#define EXT4_JOURNAL_DATA 0x00004000 /* file data should be journaled */
#define EXT4_NOTAIL 0x00008000 /* file tail should not be merged */
#define EXT4_DIRSYNC 0x00010000 /* dirsync behaviour */
#define EXT4_TOPDIR 0x00020000 /* Top of directory hierarchies*/
#define EXT4_HUGE_FILE 0x00040000 /* Set to each huge file */
#define EXT4_EXTENTS 0x00080000 /* Inode uses extents */
#define EXT4_EOFBLOCKS 0x00400000 /* Blocks allocated beyond EOF */
/*
* Definitions for nanosecond timestamps.
* Ext3 inode versioning, 2006-12-13.
*/
#define EXT3_EPOCH_BITS 2
#define EXT3_EPOCH_MASK ((1 << EXT3_EPOCH_BITS) - 1)
#define EXT3_NSEC_MASK (~0UL << EXT3_EPOCH_BITS)
#define E2DI_HAS_XTIME(ip) (EXT2_HAS_RO_COMPAT_FEATURE(ip->i_e2fs, \
EXT2F_ROCOMPAT_EXTRA_ISIZE))
#define E2DI_HAS_HUGE_FILE(ip) (EXT2_HAS_RO_COMPAT_FEATURE(ip->i_e2fs, \
EXT2F_ROCOMPAT_HUGE_FILE))
/*
* Constants relative to the data blocks
*/
#define EXT2_NDIR_BLOCKS 12
#define EXT2_IND_BLOCK EXT2_NDIR_BLOCKS
#define EXT2_DIND_BLOCK (EXT2_IND_BLOCK + 1)
#define EXT2_TIND_BLOCK (EXT2_DIND_BLOCK + 1)
#define EXT2_N_BLOCKS (EXT2_TIND_BLOCK + 1)
#define EXT2_MAXSYMLINKLEN (EXT2_N_BLOCKS * sizeof(uint32_t))
/*
* Structure of an inode on the disk
*/
struct ext2fs_dinode {
uint16_t e2di_mode; /* 0: IFMT, permissions; see below. */
uint16_t e2di_uid; /* 2: Owner UID */
uint32_t e2di_size; /* 4: Size (in bytes) */
uint32_t e2di_atime; /* 8: Access time */
uint32_t e2di_ctime; /* 12: Change time */
uint32_t e2di_mtime; /* 16: Modification time */
uint32_t e2di_dtime; /* 20: Deletion time */
uint16_t e2di_gid; /* 24: Owner GID */
uint16_t e2di_nlink; /* 26: File link count */
uint32_t e2di_nblock; /* 28: Blocks count */
uint32_t e2di_flags; /* 32: Status flags (chflags) */
uint32_t e2di_version; /* 36: Low 32 bits inode version */
uint32_t e2di_blocks[EXT2_N_BLOCKS]; /* 40: disk blocks */
uint32_t e2di_gen; /* 100: generation number */
uint32_t e2di_facl; /* 104: Low EA block */
uint32_t e2di_size_high; /* 108: Upper bits of file size */
uint32_t e2di_faddr; /* 112: Fragment address (obsolete) */
uint16_t e2di_nblock_high; /* 116: Blocks count bits 47:32 */
uint16_t e2di_facl_high; /* 118: File EA bits 47:32 */
uint16_t e2di_uid_high; /* 120: Owner UID top 16 bits */
uint16_t e2di_gid_high; /* 122: Owner GID top 16 bits */
uint16_t e2di_chksum_lo; /* 124: Lower inode checksum */
uint16_t e2di_lx_reserved; /* 126: Unused */
uint16_t e2di_extra_isize; /* 128: Size of this inode */
uint16_t e2di_chksum_hi; /* 130: High inode checksum */
uint32_t e2di_ctime_extra; /* 132: Extra change time */
uint32_t e2di_mtime_extra; /* 136: Extra modification time */
uint32_t e2di_atime_extra; /* 140: Extra access time */
uint32_t e2di_crtime; /* 144: Creation (birth)time */
uint32_t e2di_crtime_extra; /* 148: Extra creation (birth)time */
uint32_t e2di_version_hi; /* 152: High bits of inode version */
};
#endif /* !_FS_EXT2FS_EXT2_DINODE_H_ */