File system access library.

src/libdiskfs/ext2.h

@@ -0,0 +1,167 @@
+typedef struct Super Super;
+typedef struct Group Group;
+typedef struct Inode Inode;
+typedef struct Dirent Dirent;
+typedef struct Ext2 Ext2;
+
+enum
+{
+	BYTESPERSEC	= 512,
+
+	SBOFF = 1024,
+	SBSIZE = 1024,
+
+	SUPERMAGIC = 0xEF53,
+	MINBLOCKSIZE = 1024,
+	MAXBLOCKSIZE = 4096,
+	ROOTINODE = 2,
+	FIRSTINODE = 11,
+	VALIDFS = 0x0001,
+	ERRORFS = 0x0002,
+
+	NDIRBLOCKS = 12,
+	INDBLOCK = NDIRBLOCKS,
+	DINDBLOCK = INDBLOCK+1,
+	TINDBLOCK = DINDBLOCK+1,
+	NBLOCKS = TINDBLOCK+1,
+
+	NAMELEN = 255,
+
+	/* permissions in Inode.mode */
+	IEXEC = 00100,
+	IWRITE = 0200,
+	IREAD = 0400,
+	ISVTX = 01000,
+	ISGID = 02000,
+	ISUID = 04000,
+
+	/* type in Inode.mode */
+	IFMT = 0170000,
+	IFIFO = 0010000,
+	IFCHR = 0020000,
+	IFDIR = 0040000,
+	IFBLK = 0060000,
+	IFREG = 0100000,
+	IFLNK = 0120000,
+	IFSOCK = 0140000,
+	IFWHT = 0160000,
+};
+
+#define DIRLEN(namlen)	(((namlen)+8+3)&~3)
+
+
+/*
+ * Super block on-disk format.
+ */
+struct Super
+{
+	u32int	ninode;		/* Inodes count */
+	u32int	nblock;		/* Blocks count */
+	u32int	rblockcount;	/* Reserved blocks count */
+	u32int	freeblockcount;	/* Free blocks count */
+	u32int	freeinodecount;	/* Free inodes count */
+	u32int	firstdatablock;	/* First Data Block */
+	u32int	logblocksize;	/* Block size */
+	u32int	logfragsize;	/* Fragment size */
+	u32int	blockspergroup;	/* # Blocks per group */
+	u32int	fragpergroup;	/* # Fragments per group */
+	u32int	inospergroup;	/* # Inodes per group */
+	u32int	mtime;		/* Mount time */
+	u32int	wtime;		/* Write time */
+	u16int	mntcount;		/* Mount count */
+	u16int	maxmntcount;	/* Maximal mount count */
+	u16int	magic;		/* Magic signature */
+	u16int	state;		/* File system state */
+	u16int	errors;		/* Behaviour when detecting errors */
+	u16int	pad;
+	u32int	lastcheck;		/* time of last check */
+	u32int	checkinterval;	/* max. time between checks */
+	u32int	creatoros;		/* OS */
+	u32int	revlevel;		/* Revision level */
+	u16int	defresuid;		/* Default uid for reserved blocks */
+	u16int	defresgid;		/* Default gid for reserved blocks */
+	u32int	reserved[235];	/* Padding to the end of the block */
+};
+
+/*
+ * Blcok group on-disk format.
+ */
+struct Group
+{
+	u32int	bitblock;		/* Blocks bitmap block */
+	u32int	inodebitblock;		/* Inodes bitmap block */
+	u32int	inodeaddr;		/* Inodes table block */
+	u16int	freeblockscount;	/* Free blocks count */
+	u16int	freeinodescount;	/* Free inodes count */
+	u16int	useddirscount;	/* Directories count */
+	u16int	pad;
+	u32int	reserved[3];
+};
+enum
+{
+	GroupSize = 32
+};
+
+/*
+ * Structure of an inode on the disk
+ */
+struct Inode
+{
+	u16int	mode;		/* File mode */
+	u16int	uid;		/* Owner Uid */
+	u32int	size;		/* Size in bytes */
+	u32int	atime;		/* Access time */
+	u32int	ctime;		/* Creation time */
+	u32int	mtime;		/* Modification time */
+	u32int	dtime;		/* Deletion Time */
+	u16int	gid;		/* Group Id */
+	u16int	nlink;	/* Links count */
+	u32int	nblock;	/* Blocks count */
+	u32int	flags;		/* File flags */
+	u32int	osd1;				
+	u32int	block[NBLOCKS];/* Pointers to blocks */
+	u32int	version;	/* File version (for NFS) */
+	u32int	fileacl;	/* File ACL */
+	u32int	diracl;	/* Directory ACL */
+	u32int	faddr;		/* Fragment address */
+	uchar	osd2[12];
+};
+enum
+{
+	InodeSize = 128
+};
+
+/*
+ * Directory entry on-disk structure.
+ */
+struct Dirent
+{
+	u32int	ino;			/* Inode number */
+	u16int	reclen;		/* Directory entry length */
+	u8int	namlen;		/* Name length */
+	u8int	pad;
+	char	name[NAMELEN];	/* File name */
+};
+enum
+{
+	MinDirentSize = 4+2+1+1,
+};
+
+/*
+ * In-core fs info.
+ */
+struct Ext2
+{
+	uint	blocksize;
+	uint	nblock;
+	uint	ngroup;
+	uint	inospergroup;
+	uint	blockspergroup;
+	uint	inosperblock;
+	uint	groupaddr;
+	uint	descperblock;
+	uint	firstblock;
+	Disk *disk;
+	Fsys *fsys;
+};
+