Re: ext2_block_alloc_info

[Eric Sandeen <sandeen@redhat.com>]

Peter Teoh wrote:
> Sorry, resent due to SMTP error:
> 
> anyone knows any way of enumerating all the low level information like
> these for each file?
> 
> Best I can get is "debugfs":

which uses libext2fs, so if you look at the debugfs source you can find
out which basic library calls to use to get this information.

> So using "show_inode_infor xxxx":
> 
> Inode: 1146884   Type: regular    Mode:  0767   Flags: 0x0
> Generation: 4262211373
> User:     0   Group:     0   Size: 4670783
> File ACL: 0    Directory ACL: 0
> Links: 1   Blockcount: 9152
> Fragment:  Address: 0    Number: 0    Size: 0
> ctime: 0x46db7fb6 -- Mon Sep  3 11:29:58 2007
> atime: 0x47c66735 -- Thu Feb 28 15:48:05 2008
> mtime: 0x43118298 -- Sun Aug 28 17:23:36 2005
> BLOCKS:
> (0-11):2317946-0, (IND):2317958, (12-1035):2317959-0, (DIND):2318983,
> (IND):2318984, (1036-1140):2318985-0
> TOTAL: 1144
> 
> Here the "BLOCKS" correspond to the block numbering we are talking
> about, right?   It always start at 0 per-file.   "IND" is the indirect
> block.   But what is "DIND"?   "2317946" is the physical block number
> right?   And what is the zero after the "2317946"?

BLOCKS: is the logical/physical mapping for the file.

(AA-BB): YY-ZZ are (logical):physical ranges.

IND is indirect, DIND is double indirect.

As for the "XXXX-0" I'm not sure offhand; it should be the start-end
range for the physical blocks.  Bug perhaps?  :)

-Eric