Add start of mke2fs/gene2fs, and some other stuff I've been working on.

1 files changed, 241 insertions, 0 deletions

diff --git a/toys/mke2fs.c b/toys/mke2fs.c
new file mode 100644
index 00000000..a586a906
--- /dev/null
+++ b/toys/mke2fs.c
@@ -0,0 +1,241 @@
+/* vi: set ts=4:
+ *
+ * mke2fs.c - Create an ext2 filesystem image.
+ *
+ * Copyright 2006 Rob Landley <rob@landley.net>
+ */
+
+#include "toys.h"
+
+// Stuff defined in linux/ext2_fs.h
+
+#define EXT2_SUPER_MAGIC  0xEF53
+
+struct ext2_inode {
+	uint16_t mode;        // File mode
+	uint16_t uid;         // Low 16 bits of Owner Uid
+	uint32_t size;        // Size in bytes
+	uint32_t atime;       // Access time
+	uint32_t ctime;       // Creation time
+	uint32_t mtime;       // Modification time
+	uint32_t dtime;       // Deletion Time
+	uint16_t gid;         // Low 16 bits of Group Id
+	uint16_t links_count; // Links count
+	uint32_t blocks;      // Blocks count
+	uint32_t flags;       // File flags
+	uint32_t reserved1;
+	uint32_t block[15];   // Pointers to blocks
+	uint32_t generation;  // File version (for NFS)
+	uint32_t file_acl;    // File ACL
+	uint32_t dir_acl;     // Directory ACL
+	uint32_t faddr;       // Fragment address
+	uint8_t  frag;        // Fragment number
+	uint8_t  fsize;       // Fragment size
+	uint16_t pad1;
+	uint16_t uid_high;    // High bits of uid
+	uint16_t gid_high;    // High bits of gid
+	uint32_t reserved2;
+};
+
+struct ext2_super_block {
+	uint32_t inodes_count;      // Inodes count
+	uint32_t blocks_count;      // Blocks count
+	uint32_t r_blocks_count;    // Reserved blocks count
+	uint32_t free_blocks_count; // Free blocks count
+	uint32_t free_inodes_count; // Free inodes count
+	uint32_t first_data_block;  // First Data Block
+	uint32_t log_block_size;    // Block size
+	uint32_t log_frag_size;     // Fragment size
+	uint32_t blocks_per_group;  // # Blocks per group
+	uint32_t frags_per_group;   // # Fragments per group
+	uint32_t inodes_per_group;  // # Inodes per group
+	uint32_t mtime;             // Mount time
+	uint32_t wtime;             // Write time
+	uint16_t mnt_count;         // Mount count
+	uint16_t max_mnt_count;     // Maximal mount count
+	uint16_t magic;             // Magic signature
+	uint16_t state;             // File system state
+	uint16_t errors;            // Behaviour when detecting errors
+	uint16_t minor_rev_level;   // minor revision level
+	uint32_t lastcheck;         // time of last check
+	uint32_t checkinterval;     // max. time between checks
+	uint32_t creator_os;        // OS
+	uint32_t rev_level;         // Revision level
+	uint16_t def_resuid;        // Default uid for reserved blocks
+	uint16_t def_resgid;        // Default gid for reserved blocks
+	uint32_t first_ino;         // First non-reserved inode
+	uint16_t inode_size;        // size of inode structure
+	uint16_t block_group_nr;    // block group # of this superblock
+	uint32_t feature_compat;    // compatible feature set
+	uint32_t feature_incompat;  // incompatible feature set
+	uint32_t feature_ro_compat; // readonly-compatible feature set
+	char     uuid[16];          // 128-bit uuid for volume
+	char     volume_name[16];   // volume name
+	char     last_mounted[64];  // directory where last mounted
+	uint32_t alg_usage_bitmap;  // For compression
+	// For EXT2_COMPAT_PREALLOC
+	uint8_t  prealloc_blocks;   // Nr of blocks to try to preallocate
+	uint8_t  prealloc_dir_blocks; //Nr to preallocate for dirs
+	uint16_t padding1;
+	// For EXT3_FEATURE_COMPAT_HAS_JOURNAL
+	uint8_t  journal_uuid[16];   // uuid of journal superblock
+	uint32_t journal_inum;       // inode number of journal file
+	uint32_t journal_dev;        // device number of journal file
+	uint32_t last_orphan;        // start of list of inodes to delete
+	uint32_t hash_seed[4];       // HTREE hash seed
+	uint8_t  def_hash_version;   // Default hash version to use
+	uint8_t  padding2[3];
+	uint32_t default_mount_opts;
+ 	uint32_t first_meta_bg;      // First metablock block group
+	uint32_t reserved[190];      // Padding to the end of the block
+};
+
+#define EXT2_FEATURE_COMPAT_DIR_PREALLOC	0x0001
+#define EXT2_FEATURE_COMPAT_IMAGIC_INODES	0x0002
+#define EXT3_FEATURE_COMPAT_HAS_JOURNAL		0x0004
+#define EXT2_FEATURE_COMPAT_EXT_ATTR		0x0008
+#define EXT2_FEATURE_COMPAT_RESIZE_INO		0x0010
+#define EXT2_FEATURE_COMPAT_DIR_INDEX		0x0020
+
+#define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER	0x0001
+#define EXT2_FEATURE_RO_COMPAT_LARGE_FILE	0x0002
+#define EXT2_FEATURE_RO_COMPAT_BTREE_DIR	0x0004
+
+#define EXT2_FEATURE_INCOMPAT_COMPRESSION	0x0001
+#define EXT2_FEATURE_INCOMPAT_FILETYPE		0x0002
+#define EXT3_FEATURE_INCOMPAT_RECOVER		0x0004
+#define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV	0x0008
+#define EXT2_FEATURE_INCOMPAT_META_BG		0x0010
+
+#define EXT2_NAME_LEN 255
+
+struct ext2_dir_entry_2 {
+	uint32_t inode;         // Inode number
+    uint16_t rec_len;       // Directory entry length
+    uint8_t  name_len;      // Name length
+    uint8_t  file_type;
+	char     name[255];     // File name
+};
+
+// Ext2 directory file types.  Only the low 3 bits are used.  The
+// other bits are reserved for now.
+
+enum {
+	EXT2_FT_UNKNOWN,
+	EXT2_FT_REG_FILE,
+	EXT2_FT_DIR,
+	EXT2_FT_CHRDEV,
+	EXT2_FT_BLKDEV,
+	EXT2_FT_FIFO,
+	EXT2_FT_SOCK,
+	EXT2_FT_SYMLINK,
+	EXT2_FT_MAX
+};
+
+
+	// b - block size (1024, 2048, 4096)
+	// F - force (run on mounted device or non-block device)
+	// i - bytes per inode 
+	// N - number of inodes
+	// m - reserved blocks percentage
+	// n - Don't write
+	// q - quiet
+
+	// L - volume label
+	// M - last mounted path
+	// o - creator os
+	
+	// j - create journal
+	// J - journal options (size=1024-102400 blocks,device=)
+	//        device=/dev/blah or LABEL=label UUID=uuid
+
+	// E - extended options (stride=stripe-size blocks)
+	// O - none,dir_index,filetype,has_journal,journal_dev,sparse_super
+
+
+// This is what's in a UUID according to the spec at
+// http://www.opengroup.org/onlinepubs/9629399/apdxa.htm
+
+//struct uuid {
+//	uint32_t  time_low;
+//	uint16_t  time_mid;
+//	uint16_t  time_hi_and_version;
+//	uint8_t   clock_seq_hi_and_reserved;
+//	uint8_t   clock_seq_low;
+//	uint8_t   node[6];
+//};
+
+
+// According to http://www.opengroup.org/onlinepubs/9629399/apdxa.htm
+// we should generate a uuid structure by reading a clock with 100 nanosecond
+// precision, normalizing it to the start of the gregorian calendar in 1582,
+// and looking up our eth0 mac address.
+//
+// On the other hand, we have 128 bits to come up with a unique identifier, of
+// which 6 have a defined value.  /dev/urandom it is.
+
+void create_uuid(char *uuid)
+{
+	// Read 128 random bytes
+	int fd = xopen("/dev/urandom", O_RDONLY);
+	xreadall(fd, uuid, 16);
+	close(fd);
+
+	// Claim to be a DCE format UUID.
+	uuid[6] = (uuid[6] & 0x0F) | 0x40;
+	uuid[8] = (uuid[8] & 0x3F) | 0x80;
+
+    // rfc2518 section 6.4.1 suggests if we're not using a macaddr, we should
+	// set bit 1 of the node ID, which is the mac multicast bit.  This means we
+	// should never collide with anybody actually using a macaddr.
+	uuid[11] = uuid[11] | 128;
+}
+
+int mke2fs_main(void)
+{
+	struct ext2_super_block *sb = xzalloc(sizeof(struct ext2_super_block));
+	int temp;
+
+	// Handle command line arguments.
+
+	if (!*toys.optargs || (!CFG_MKE2FS_GEN && toys.optargs[1])) usage_exit();
+	if (CFG_MKE2FS_GEN && toys.optargs[1]) {
+			temp = O_RDWR|O_CREAT;
+			xaccess(toys.optargs[1], R_OK);
+	} else temp = O_RDWR;
+	if (toy.mke2fs.blocksize!=1024 && toy.mke2fs.blocksize!=2048
+		&& toy.mke2fs.blocksize!=4096) error_exit("bad blocksize");
+
+	// For mke?fs, open file.  For gene?fs, create file.
+	toy.mke2fs.fsfd = xcreate(*toys.optargs, temp, 0777);
+
+    // We don't autodetect block size from external journaling devices, instead
+	// we write our block size to that journaling device.  (If they want a
+	// specific block size, they have the -b option.)
+
+// What's the deal with fs_type?
+// line 1059
+
+	// We skip the first 1k (to avoid the boot sector, if any).  Use this to
+	// figure out if this file is seekable.
+	if(-1 == lseek(toy.mke2fs.fsfd, 1024, SEEK_SET)) {
+		toy.mke2fs.noseek=1;
+		xwrite(toy.mke2fs.fsfd, sb, 1024);
+	}
+
+	// Fill out superblock structure
+
+	sb->rev_level = SWAP_LE32(1);
+	sb->feature_incompat = SWAP_LE32(EXT2_FEATURE_INCOMPAT_FILETYPE);
+	sb->feature_ro_compat = SWAP_LE32(EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER);
+
+	// If we're called as mke3fs or mkfs.ext3, do a journal.
+
+	if (strchr(toys.which->name,'3'))
+		sb->feature_compat |= EXT3_FEATURE_COMPAT_HAS_JOURNAL;
+
+	// Write superblock to disk.	
+	xwrite(toy.mke2fs.fsfd, sb, 3072); // 4096-1024
+
+	return 0;
+}