---------- Forwarded message ---------- From: Alexander Harrowell <a.harrowell@xxxxxxxxx> Date: Thu, Sep 12, 2013 at 4:54 PM Subject: Re: Fwd: strange e2fsck magic number behaviour To: Eric Sandeen <sandeen@xxxxxxxxxx> It was 63GB and I just wanted to fork over 3GB of extra space from my Windows partition... The fstab is as follows /dev/sda1 SYSTEM_DRV ntfs 1.17g (boot) /dev/sda2 Windows7_OS ntfs 63.4G /dev/sda4 extended partition containing: -- /dev/sda6 swap linux-swap 8.05G -- /dev/sda5 /home ext4 66.14G /dev/sda3 Lenovo_Recovery ntfs 10.25G unallocated 1M that's what was intended and is what gparted reports. (however, weirdly, if you ask Ubuntu Disk Utility, it says /dev/sda5 is 71GB and /dev/sda4 is correspondingly bigger. this I have only just noticed.) kernel is 3.2.0-29-generic, machine is a ThinkPad X200s with 160GB disk. thanks for your help. On Thu, Sep 12, 2013 at 4:44 PM, Eric Sandeen <sandeen@xxxxxxxxxx> wrote: > On 9/12/13 11:39 AM, Alexander Harrowell wrote: >> I'm currently trying to recover an ext4 filesystem. Last night, during >> a resize operation, > > from what size to what size? On what kernel? > >> the system (Ubuntu 12.04 LTS on my fix-stuff usb >> stick) locked up hard and eventually crashed. Restarting, >> unsurprisingly, gparted offered to check the volume. e2fsck, called >> from within gparted, replayed the journal overnight and completed the >> resize. > > hmmm... perhaps. > >> however, where I was expecting a volume with about 3.5GB of free >> space, there was now a volume with 32GB free space, a bit more than >> 50% utilised. inevitably, trying to boot the linux that lives in there >> dropped into grub rescue. >> >> going back, I tried to e2fsck it. this reported large numbers of inode >> issues and eventually reported clean. I could mount the volume, but >> file metadata looked generally broken (lots of ?s). testdisk showed >> the partitions were intact, although it claimed the drive was the >> wrong size (incorrectly), and found lots of deleted files within my >> ecryptfs home folder. It also found the backup superblocks for the >> damaged volume. >> >> the first couple I tried were corrupt, but the third was valid. e2fsck >> -b [superblock] -y reports fixing a lot of inode things, checksums, >> and then restarts. it then starts to report hunormous numbers of >> multiply-claimed blocks. >> >> and now comes the interesting bit - at some point, block 16777215 >> starts to appear more and more often in the inodes, often duplicated, >> until it starts to print out the number 16777215 in a fast loop. in >> fact, it looks like it hits some inode and keeps printing block >> 16777215 to the same very long line (it's generated 500MB of log) > > = 111111111111111111111111 binary. > > Guessing it's maybe a bitmap block? > > Resize2fs has had a lot of trouble lately it seems. You may have just > been the unlucky recipient of a resize2fs bug... > > -Eric > >> I removed the first inode containing this block via debugfs, without >> this helping. >> >> It sticks out that 16777215 is a magic number (the maximum in a 48 bit >> address space) and I google that either ext4 or e2fsck has had a bug >> involving it before. >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-ext4" in >> the body of a message to majordomo@xxxxxxxxxxxxxxx >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> > -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
