On Thu, Mar 02, 2000 at 01:25:22PM -0600, Oleg Krivosheev wrote:
> On Thu, 2 Mar 2000 kmself@ix.netcom.com wrote:
>
> > On Thu, Mar 02, 2000 at 10:19:40AM -0500, Allan M. Wind wrote:
> > > On 2000-03-01 23:42:37, kmself@ix.netcom.com wrote:
> > > > On Wed, Mar 01, 2000 at 07:05:04PM -0500, Allan M. Wind wrote:
> > > > > On 2000-03-01 23:42:21, Mary Honeycutt wrote:
> > >
> > > > tar cf - source | ( cd /target; tar xpf - )
> > >
> > > Yes, that would be more like it.
> >
> > Thought so. I'd hate for someone to find out the hard way....
> >
> > > > There's a utility to recreate the lost+found directory if you do manage
> > > > to overwrite it -- it needs to sit on a specific inode for the
> > > > filesystem
> > > > to be able to recover lost clusters properly. RTFM, it's there
> > > > somewhere.
> > >
> > > Isn't lost+found created by mkfs?
> >
> > Yes, it is (or mke2fs, or whatever). My understanding of this is
> > somewhat limited, but here goes.
> >
> > Files and directories are identified under most Linux-like fileystems
> > (e2fs, minix fs, UFS, etc., but *not* msdos, vfat), by inodes. An inode
> > is essentially a database entry in a table giving storage location,
> > name, and values of several attributes (read/write/execute/suid), etc.
> ^^^^^^
>
> name? Files are nameless in UNIX. Read about hard links for example
> And from inode you should get storage, attirbutes, times (creation,
> access) and reference counter.
lost+found inode is 11 for ext2fs. Do:
ls -id /lost+found
As I said, limited understand. You're right, file name is referenced
only in the directory entry itself, which links an inode to a name.
Renaming myself Luke and using the source shows the structures.
I don't find the lost+found inode definition though. Anyone?
**********************************
** /usr/include/linux/ext2_fs.h **
**********************************
------------------------------------------------------------------------
[...]
/*
* Special inodes numbers
*/
#define EXT2_BAD_INO 1 /* Bad blocks inode */
#define EXT2_ROOT_INO 2 /* Root inode */
#define EXT2_ACL_IDX_INO 3 /* ACL inode */
#define EXT2_ACL_DATA_INO 4 /* ACL inode */
#define EXT2_BOOT_LOADER_INO 5 /* Boot loader inode */
#define EXT2_UNDEL_DIR_INO 6 /* Undelete directory inode */
/* First non-reserved inode for old ext2 filesystems */
#define EXT2_GOOD_OLD_FIRST_INO 11
[...]
/*
* Structure of an inode on the disk
*/
struct ext2_inode {
__u16 i_mode; /* File mode */
__u16 i_uid; /* Owner Uid */
__u32 i_size; /* Size in bytes */
__u32 i_atime; /* Access time */
__u32 i_ctime; /* Creation time */
__u32 i_mtime; /* Modification time */
__u32 i_dtime; /* Deletion Time */
__u16 i_gid; /* Group Id */
__u16 i_links_count; /* Links count */
__u32 i_blocks; /* Blocks count */
__u32 i_flags; /* File flags */
union {
struct {
__u32 l_i_reserved1;
} linux1;
struct {
__u32 h_i_translator;
} hurd1;
struct {
__u32 m_i_reserved1;
} masix1;
} osd1; /* OS dependent 1 */
__u32 i_block[EXT2_N_BLOCKS];/* Pointers to blocks */
__u32 i_version; /* File version (for NFS) */
__u32 i_file_acl; /* File ACL */
__u32 i_dir_acl; /* Directory ACL */
__u32 i_faddr; /* Fragment address */
union {
struct {
__u8 l_i_frag; /* Fragment number */
__u8 l_i_fsize; /* Fragment size */
__u16 i_pad1;
__u32 l_i_reserved2[2];
} linux2;
struct {
__u8 h_i_frag; /* Fragment number */
__u8 h_i_fsize; /* Fragment size */
__u16 h_i_mode_high;
__u16 h_i_uid_high;
__u16 h_i_gid_high;
__u32 h_i_author;
} hurd2;
struct {
__u8 m_i_frag; /* Fragment number */
__u8 m_i_fsize; /* Fragment size */
__u16 m_pad1;
__u32 m_i_reserved2[2];
} masix2;
} osd2; /* OS dependent 2 */
};
[...]
/*
* Structure of a directory entry
*/
#define EXT2_NAME_LEN 255
struct ext2_dir_entry {
__u32 inode; /* Inode number */
__u16 rec_len; /* Directory entry length */
__u16 name_len; /* Name length */
char name[EXT2_NAME_LEN]; /* File name */
};
------------------------------------------------------------------------
--
Karsten M. Self (kmself@ix.netcom.com)
What part of "Gestalt" don't you understand?
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