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ext2fs documentation

Posted: Mon Feb 11, 2008 12:24 pm
by octavio
Hello ,i'm searching info about ext2fs structure but all i have found are overviews and data does not match with the ext2fs i have on my hard disk
has someone a doc good enought to write drivers?

Posted: Mon Feb 11, 2008 1:07 pm
by Brynet-Inc
After searching Google, I've found a few sites that might be helpful to you..

http://www.nongnu.org/ext2-doc/ seems rather complete, if not slighly dated...

Other helpful sites:
http://web.mit.edu/tytso/www/linux/ext2intro.html
http://uranus.it.swin.edu.au/~jn/explore2fs/es2fs.htm

Optionally, OpenBSD/NetBSD and FreeBSD all have BSD-style licenced implementations you can look at, and of coarse, Linux has GPL source available as well.

Good luck.. 8)

Posted: Mon Feb 11, 2008 2:19 pm
by octavio
Thanks,the third link seems to be complete,the first two are only a overview.
is ext2fs limited to 4GB filesize?

Posted: Mon Feb 11, 2008 2:50 pm
by JamesM
Hi,

I've had no problems whatsoever regarding data on the internet and current implementations of ext2/ext3. The standard ext2 spec will get you well on your way - I would advise you to look inwards at your own implementation if something doesn't play right - it works fine for me.

Ext2 is *not* limited to 4GB, because it uses an indirection system - read the manual.

Posted: Tue Feb 12, 2008 4:15 am
by octavio
JamesM wrote:Hi,

Ext2 is *not* limited to 4GB, because it uses an indirection system - read the manual.
what manual?

Posted: Tue Feb 12, 2008 4:17 am
by AJ
See Brynet's post.

Posted: Tue Feb 12, 2008 8:54 am
by octavio
JamesM wrote: Ext2 is *not* limited to 4GB, because it uses an indirection system - read the manual.
Not sure if i'm reading the same manual but
1.5.3. i_size
32bit value indicating the size of the file in bytes.

Posted: Tue Feb 12, 2008 9:37 am
by JamesM
1.5.16. i_dir_acl

32bit value used to indicate the "high size" of the file. In previous revisions this value was always 0.
Which makes a 64 bit value (i_size | (i_dir_acl << 32)).