Date: Wed, 18 Feb 2004 13:12:47 +1100 From: Tim Robbins <tjr@freebsd.org> To: Bruce Evans <bde@zeta.org.au> Cc: Kris Kennaway <kris@obsecurity.org> Subject: Re: Anyway to extract a large file from EXT2FS filesystem? Message-ID: <20040218021247.GA28724@cat.robbins.dropbear.id.au> In-Reply-To: <20040218112014.V19484@gamplex.bde.org> References: <20040217103909.N73217@yabba.500mhz.net> <20040217100822.GA13286@xor.obsecurity.org> <20040217110937.Y73217@yabba.500mhz.net> <20040217102121.GA13632@xor.obsecurity.org> <20040217112251.GA25431@cat.robbins.dropbear.id.au> <20040218112014.V19484@gamplex.bde.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On Wed, Feb 18, 2004 at 11:37:26AM +1100, Bruce Evans wrote: > On Tue, 17 Feb 2004, Tim Robbins wrote: > > > > 5BOn Tue, Feb 17, 2004 at 11:16:50AM +0100, Stefan Krantz wrote: > > > > > > 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? > > > 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; > > > > The feature stuff needs to be handled for writing. I discovered that a few minutes after posting the patch :-) I decided to take the lazy way out for now and to return EFBIG if we would need to upgrade the filesystem to EXT2_DYNAMIC_REV or set ..._RO_COMPAT_LARGE_FILE. I think what's most important here is being able to read large files from Linux ext2 filesystems, and I don't like the current ext2 code enough to implement superblock updating etc. Tim
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20040218021247.GA28724>