On Mon, Jan 17, 2005 at 05:46:35PM -0200, Marcelo Tosatti wrote: > On Sun, Jan 16, 2005 at 12:35:30AM +0100, Mario Holbe wrote:
> > mounting an ext2 (ext3 as well) filesystem seems to modify the > > block device's EOF behaviour: before the mount the device returned > > EOF, after the mount it doesn't anymore: > > > > [on a fresh booted system] > > [EMAIL PROTECTED]:~# uname -a > > Linux darkside 2.4.27 #1 Sat Jan 15 17:07:20 CET 2005 i686 GNU/Linux > > [EMAIL PROTECTED]:~# dd if=/dev/hdg7 of=/dev/null > > 9992366+0 records in > > 9992366+0 records out > > [EMAIL PROTECTED]:~# mount -t ext2 -o ro /dev/hdg7 /mnt > > [EMAIL PROTECTED]:~# umount /dev/hdg7 > > [EMAIL PROTECTED]:~# dd if=/dev/hdg7 of=/dev/null > > attempt to access beyond end of device > > 22:07: rw=0, want=4996184, limit=4996183 > > dd: reading `/dev/hdg7': Input/output error > > 9992360+0 records in > > 9992360+0 records out > > [EMAIL PROTECTED]:~# bc > > 1249045 * 4 > > 4996180 > > 1249045 * 4 * 2 > > 9992360 > > > > Could somebody please explain this to me? Is this intentional? > > No > > Its indeed strange. I suppose that what happens is the following: mounting sets the blocksize to 4096. After reading 9992360 sectors, reading the next block means reading the next 8 sectors and that fails because only 6 sectors are left. Test that this is what happens using blockdev --getbsz. If you want to restore the device to full size, use blockdev --setbsz 512. Andries - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/