Anyway to extract a large file from EXT2FS filesystem?

[Tim Robbins]

On Tue, Feb 17, 2004 at 02:21:21AM -0800, Kris Kennaway wrote:

> 5BOn Tue, Feb 17, 2004 at 11:16:50AM +0100, Stefan Krantz wrote:
> > 
> > On Tue, 17 Feb 2004, Kris Kennaway wrote:
> > 
> > > On Tue, Feb 17, 2004 at 10:49:47AM +0100, Stefan Krantz wrote:
> > > >
> > > > Hi!
> > > >
> > > > I would like to extract a large (11GB) tar file on an ext3 filesystem. But
> > > > it shows only to be about 3gb large:
> > > >
> > > > yabba# ls -la pictures.tar
> > > > -rw-r--r--  1 root  wheel  3317055488 Feb 15 19:03 pictures.tar
> > > >
> > > > Is there any possible way to extract the file?
> > >
> > > It shouldn't be appearing truncated.  Are you certain that this size
> > > is incorrect, and the file has a different size when viewed from
> > > another OS?
> > 
> > Yes. Yesterday I tested the archive with "tar tvf" (11gb) in
> > Linux and it tested OK. In FBSD it says "unexpected EOF".
> > 
> > If I could i would just boot linux and split the file. But I can nolonger
> > boot linux =/ (migrated to fbsd 5.2 ;).
> 
> I'm CC'ing tjr and bde, who might have some idea about the problem.

Try this patch and let me know how it goes. You'll have to specify
the file name of /sys/gnu/ext2fs/ext2_inode_cnv.c to patch(1) manually,
then either buildkernel or rebuild only ext2fs.ko. If the file shows
up with the correct size in a directory listing, make sure you can actually
read data past 4 GB.

==== //depot/user/tjr/freebsd-tjr/src/sys/gnu/ext2fs/ext2_inode_cnv.c#1 - /p4/tjr/src/sys/gnu/ext2fs/ext2_inode_cnv.c ====
@@ -77,6 +77,8 @@
 	*/
 	ip->i_mode = ei->i_links_count ? ei->i_mode : 0;
 	ip->i_size = ei->i_size;
+	if (S_ISREG(ip->i_mode))
+		ip->i_size |= ((u_int64_t)ei->i_size_high) << 32;
 	ip->i_atime = ei->i_atime;
 	ip->i_mtime = ei->i_mtime;
 	ip->i_ctime = ei->i_ctime;
@@ -112,6 +114,8 @@
 	 */
 	ei->i_dtime = ei->i_links_count ? 0 : ip->i_mtime;
 	ei->i_size = ip->i_size;
+	if (S_ISREG(ip->i_mode))
+		ei->i_size_high = ip->i_size >> 32;
 	ei->i_atime = ip->i_atime;
 	ei->i_mtime = ip->i_mtime;
 	ei->i_ctime = ip->i_ctime;