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Date: Fri, 13 Sep 2013 13:34:13 +0000 From: Alexander Harrowell <a.harrowell@...il.com> To: Eric Sandeen <sandeen@...hat.com> Cc: linux-ext4@...r.kernel.org Subject: Re: Fwd: Fwd: strange e2fsck magic number behaviour example: Block Inode number 16777215 2937846 debugfs: clri <2937846> debugfs: icheck 16777215 Block Inode number 16777215 2937854 debugfs: clri <2937854> debugfs: icheck 16777215 Block Inode number 16777215 2937862 debugfs: clri <2937862> debugfs: icheck 16777215 Block Inode number 16777215 2937870 debugfs: clri <2937870> debugfs: icheck 16777215 Block Inode number 16777215 2937878 debugfs: clri <2937878> debugfs: icheck 16777215 debugfs: block_dump 16777215 0000 0000 0000 0000 0000 0000 0000 0000 0000 ................ * 2720 0000 0000 0000 0000 0000 0000 ffff ff00 ................ 2740 0000 0000 0000 0000 0000 0000 0000 0000 ................ * 3620 0000 0000 0000 0000 0000 0000 ffff ff00 ................ 3640 ffff ff00 ffff ff00 ffff ff00 ffff ff00 ................ * 4000 ffff ff00 ffff ff00 ffff ff00 0000 0000 ................ 4020 0000 0000 0000 0000 0000 0000 0000 0000 ................ * 4400 ffff ff00 ffff ff00 ffff ff00 ffff ff00 ................ * 4720 ffff ff00 ffff ff00 ffff ff00 0000 0000 ................ 4740 0000 0000 0000 0000 0000 0000 0000 0000 ................ * 5640 ffff ff00 ffff ff00 ffff ff00 ffff ff00 ................ * 6000 ffff ff00 ffff ff00 0000 0000 0000 0000 ................ 6020 0000 0000 0000 0000 0000 0000 0000 0000 ................ * 6400 0000 0000 ffff ff00 ffff ff00 ffff ff00 ................ 6420 ffff ff00 ffff ff00 ffff ff00 ffff ff00 ................ * 6720 ffff ff00 ffff ff00 0000 0000 0000 0000 ................ 6740 0000 0000 0000 0000 0000 0000 0000 0000 ................ * 7640 0000 0000 0000 0000 ffff ff00 ffff ff00 ................ 7660 ffff ff00 ffff ff00 ffff ff00 ffff ff00 ................ * 7720 ffff ff00 0000 0000 0000 0000 0000 0000 ................ 7740 0000 0000 0000 0000 0000 0000 0000 0000 ................ * On Fri, Sep 13, 2013 at 1:33 PM, Alexander Harrowell <a.harrowell@...il.com> wrote: > Hmm, coming back to this, block 16777215 with identical content is > recurring at intervals of 8 inodes. > > On Fri, Sep 13, 2013 at 11:46 AM, Alexander Harrowell > <a.harrowell@...il.com> wrote: >> To update, I've found that a) even with 8GB RAM and 8GB swap, e2fsck >> can silently run out of memory. >> >> b) something is clearly wrong in block 16777215. >> >> c) debugfs places that block in inode 409774, in use, with an extent >> of 16777212-5 and 10 associated filenames, plus several dozen ext2 >> directory errors. >> >> d) after a first attempt with the updated (1.42.8) version of >> e2fsprogs this morning, the disk is mountable again but not much on it >> is accessible and the % usage is still screwy. >> >> e) that said, "new" debugfs and e2fsck seem to find more things to fix. >> >> f) trying to decrypt the filenames, most of them don't get found by >> ecryptfs-find but the first one produces a list of the files in /home/ >> and a lot of find: no such file or directory messages. >> >> g) dumpe2fs -b reports no bad blocks. smart reports drive in good condition. >> >> h) I'm quite tempted to zap 409774. >> >> On Thu, Sep 12, 2013 at 7:33 PM, Alexander Harrowell >> <a.harrowell@...il.com> wrote: >>> investigating dmesg, I think e2fsck may have been running out of memory. >>> >>> On Thu, Sep 12, 2013 at 6:59 PM, Eric Sandeen <sandeen@...hat.com> wrote: >>>> On 9/12/13 11:56 AM, Alexander Harrowell wrote: >>>>> ---------- Forwarded message ---------- >>>>> From: Alexander Harrowell <a.harrowell@...il.com> >>>>> Date: Thu, Sep 12, 2013 at 4:54 PM >>>>> Subject: Re: Fwd: strange e2fsck magic number behaviour >>>>> To: Eric Sandeen <sandeen@...hat.com> >>>>> >>>>> >>>>> It was 63GB and I just wanted to fork over 3GB of extra space from my >>>>> Windows partition... >>>> >>>> Ok, so you tried to resize from 63G to 66G? Should have been relatively >>>> easy/safe. I forgot to ask which version of e2fsprogs you had, but if >>>> you did the grow online/mounted, most of the work is done in the kernel. >>>> >>>> As Ted said, knowing more info might yield clues: >>>> >>>> 1) what e2fsprogs version? >>>> 2) what were the kernel messages when it crashed/hung? >>>> 3) what was the fsck output? >>>> >>>> If you didn't save that stuff, it makes it harder to do a post-mortem... >>>> >>>>> 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.) >>>> >>>> TBH, I have no idea what Ubuntu Disk Utility does. I'd trust fdisk -lu >>>> output or /proc/partitions for accurate size info. >>>> >>>> Oh; 61.14GiB (powers of 2) == 71 GB (powers of 10) >>>> >>>> (61.14*1024*1024*1024/1000/1000/1000 = 71) >>>> >>>> So Ubuntu Disk Utility is in cahoots w/ the drive manufacturers, and >>>> using more favorable units. ;) >>>> >>>> -Eric >>>> >>>>> 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@...hat.com> 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@...r.kernel.org >>>>>>> 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@...r.kernel.org >>>>> 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@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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