RE: Query FSCK Errors on ext4

["Stephen Elliott" <techweb@ntlworld.com>]

Thanks for the reply guys...

The device in question is a ReadyNAS Pro 6, which happens to be running Linux :) I actually saw some issues with e2fsck 1.42.3 earlier this year:

***** File system check forced at Fri Apr 26 20:08:38 WEST 2013 ***** fsck 1.41.14 (22-Dec-2010) e2fsck 1.42.3 (14-May-2012) Pass 1: Checking inodes, blocks, and sizes Inode 4195619, i_blocks is 3135728, should be 3135904. Fix? yes

Running additional passes to resolve blocks claimed by more than one inode...
Pass 1B: Rescanning for multiply-claimed blocks Multiply-claimed block(s) in inode 4195619: 167904376 167904377 167904378 167904379 167904380 167904381 167904382 167904383 167904384 167904385 167904386 167949296 167949297 167949298 167949299 167949300 167949301 167949302 167949303 167949304 167949305 167949306 Pass 1C: Scanning directories for inodes with multiply-claimed blocks Pass 1D: Reconciling multiply-claimed blocks (There are 1 inodes containing multiply-claimed blocks.)

File /PREMIER/Premier Automation Purchase OrdersApp V18.5.mdb (inode #4195619, mod time Fri Apr 26 20:07:42 2013)
 has 22 multiply-claimed block(s), shared with 0 file(s):
Multiply-claimed blocks already reassigned or cloned.

Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information

/dev/c/c: ***** FILE SYSTEM WAS MODIFIED *****
/dev/c/c: 615898/30212096 files (13.6% non-contiguous), 62353456/483393536 blocks

After deleting the file (MS Access DB, and re-creating from backup, the file system got mounted read only and the following errors were logged:]

May 8 14:58:15 despair kernel: EXT4-fs error (device dm-0: mb_free_blocks:1411: group 5124block 167904376:freeing already freed block (bit 1144
May 8 14:58:15 despair kernel: Aborting journal on device dm-0-8.
May 8 14:58:15 despair kernel: EXT4-fs (dm-0: Remounting filesystem read-only
May 8 14:58:15 despair kernel: EXT4-fs error (device dm-0: mb_free_blocks:1411: group 5124block 167904377:freeing already freed block (bit 1145
May 8 14:58:15 despair kernel: EXT4-fs error (device dm-0: mb_free_blocks:1411: group 5124block 167904378:freeing already freed block (bit 1146
May 8 14:58:15 despair kernel: EXT4-fs error (device dm-0: mb_free_blocks:1411: group 5124block 167904379:freeing already freed block (bit 1147
May 8 14:58:15 despair kernel: EXT4-fs error (device dm-0: mb_free_blocks:1411: group 5124block 167904380:freeing already freed block (bit 1148
May 8 14:58:15 despair kernel: EXT4-fs error (device dm-0: mb_free_blocks:1411: group 5124block 167904381:freeing already freed block (bit 1149
May 8 14:58:15 despair kernel: EXT4-fs error (device dm-0: mb_free_blocks:1411: group 5124block 167904382:freeing already freed block (bit 1150
May 8 14:58:16 despair kernel: EXT4-fs error (device dm-0: mb_free_blocks:1411: group 5124block 167904383:freeing already freed block (bit 1151
May 8 14:58:16 despair kernel: EXT4-fs error (device dm-0: mb_free_blocks:1411: group 5124block 167904384:freeing already freed block (bit 1152
May 8 14:58:16 despair kernel: EXT4-fs error (device dm-0: mb_free_blocks:1411: group 5124block 167904385:freeing already freed block (bit 1153
May 8 14:58:16 despair kernel: EXT4-fs error (device dm-0: mb_free_blocks:1411: group 5124block 167904386:freeing already freed block (bit 1154
May 8 14:58:16 despair kernel: EXT4-fs error (device dm-0: mb_free_blocks:1411: group 5125block 167949296:freeing already freed block (bit 13296
May 8 14:58:16 despair kernel: EXT4-fs error (device dm-0: mb_free_blocks:1411: group 5125block 167949297:freeing already freed block (bit 13297
May 8 14:58:16 despair kernel: EXT4-fs error (device dm-0: mb_free_blocks:1411: group 5125block 167949298:freeing already freed block (bit 13298
May 8 14:58:16 despair kernel: EXT4-fs error (device dm-0: mb_free_blocks:1411: group 5125block 167949299:freeing already freed block (bit 13299
May 8 14:58:17 despair kernel: EXT4-fs error (device dm-0: mb_free_blocks:1411: group 5125block 167949300:freeing already freed block (bit 13300
May 8 14:58:17 despair kernel: EXT4-fs error (device dm-0: mb_free_blocks:1411: group 5125block 167949301:freeing already freed block (bit 13301
May 8 14:58:17 despair kernel: EXT4-fs error (device dm-0: mb_free_blocks:1411: group 5125block 167949302:freeing already freed block (bit 13302
May 8 14:58:17 despair kernel: EXT4-fs error (device dm-0: mb_free_blocks:1411: group 5125block 167949303:freeing already freed block (bit 13303
May 8 14:58:17 despair kernel: EXT4-fs error (device dm-0: mb_free_blocks:1411: group 5125block 167949304:freeing already freed block (bit 13304
May 8 14:58:17 despair kernel: EXT4-fs error (device dm-0: mb_free_blocks:1411: group 5125block 167949305:freeing already freed block (bit 13305
May 8 14:58:17 despair kernel: EXT4-fs error (device dm-0: mb_free_blocks:1411: group 5125block 167949306:freeing already freed block (bit 13306


These are the same blocks slated as multiply claimed 

And then running an FSCK, we got the following:

***** File system check forced at Wed May 8 15:16:50 WEST 2013 ***** fsck 1.41.14 (22-Dec-2010 e2fsck 1.42.3 (14-May-2012
/dev/c/c: recovering journal
Pass 1: Checking inodes, blocks, and sizes Pass 2: Checking directory structure Pass 3: Checking directory connectivity Pass 4: Checking reference counts Pass 5: Checking group summary information Free blocks count wrong for group #5124 (28170, counted=28159.
Fix? yes

Free blocks count wrong for group #5125 (25861, counted=25850.
Fix? yes

Free blocks count wrong (420683133, counted=420644972.
Fix? yes

Free inodes count wrong (29595347, counted=29595271.
Fix? yes


/dev/c/c: ***** FILE SYSTEM WAS MODIFIED *****
/dev/c/c: 616825/30212096 files (13.6% non-contiguous, 62748564/483393536 blocks

Then later in the year I reloaded the server with the database open from several client machines

***** File system check forced at Tue Jul 23 21:02:13 WEST 2013 ***** fsck 1.42.8 (20-Jun-2013) e2fsck 1.42.8 (20-Jun-2013) Pass 1: Checking inodes, blocks, and sizes Inode 4195619, end of extent exceeds allowed value
                (logical block 64907, physical block 11435403, len 16) Clear? yes

Inode 4195619, i_blocks is 1337216, should be 1337176.  Fix? yes

Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information Block bitmap differences:  -(11435403--11435407) Fix? yes

Free blocks count wrong for group #348 (2130, counted=2135).
Fix? yes

Free blocks count wrong (417470107, counted=417470112).
Fix? yes


/dev/c/c: ***** FILE SYSTEM WAS MODIFIED *****
/dev/c/c: 625785/30212096 files (13.6% non-contiguous), 65923424/483393536 blocks

Again related to the same file, which is only an MS Access DB open from several client machines over SMB when the server is rebooted. Moving forward I ensure all instances are closed when reloading but even so I am surprised that a clean reload causes corruption at the filesystem level.

Since ensuring the DB is closed before reload, I have seen no further issues like this.

Many Thanks
Stephen Elliott

-----Original Message-----
From: Zheng Liu [mailto:gnehzuil.liu@gmail.com] 
Sent: 28 October 2013 06:39
To: Andreas Dilger
Cc: Stephen Elliott; David Jeffery; linux-ext4@vger.kernel.org List; Bernd Schubert; Eric Whitney
Subject: Re: Query FSCK Errors on ext4

[Cc Eric Whitney to confirm this problem]

Hi Andreas,

If I remember correctly, this patch might can fix this problem [1].

1. http://www.spinics.net/lists/linux-ext4/msg39485.html

Regards,
                                                - Zheng

On Mon, Oct 28, 2013 at 12:13:26AM -0600, Andreas Dilger wrote:
> The error reported here is a relatively new one.  It only appeared in 
> e2fsck 1.42.8, and wasn t in the code that I m using locally (1.42.7) 
> so I wasn t sure what it actually meant without looking at it.
> 
> It looks like some kind of overflow of the extent tree, which causes 
> e2fsck to chop off the last 5 disk blocks (40 sectors), though I m not 
> sure exactly why.  From your comments, this can be reproduced with 
> your database usage?  Does it use fallocate() or any other strange IO 
> operations that might be causing this?
> 
> Have you tried updating your kernel?  If there is repeated corruption 
> appearing in the filesystem, then it is either a bug in the kernel or 
> in e2fsck.  Not really sure which one to blame at this point.
> 
> Cheers, Andreas
> 
> On Oct 18, 2013, at 9:45 AM, Stephen Elliott <techweb@ntlworld.com> wrote:
> 
> > Any feedback on this guys??? Would really appreciate somebody taking a look over this.
> >  
> > From: Stephen Elliott [mailto:techweb@ntlworld.com]
> > Sent: 22 September 2013 20:13
> > To: linux-ext4@vger.kernel.org; linux-fsdevel@vger.kernel.org; Andreas Dilger (adilger@dilger.ca); 'Bernd Schubert'
> > Subject: Query FSCK Errors on ext4
> >  
> > Hi all,
> >  
> > I have theorised that the problem comes from the MS access DB being open (over Samba) on client workstations when the server is reloaded.
> >  
> > Since ensuring these are closed prior to reloading, I have not seen further FSCK errors on reload. Is there an explanation for this? I can see why this may corrupt DB but not the filesystem.
> >  
> > Just as a primer, I used a ReadyNAS NV+ for many years which was running ext3 and never had this issue. However, since using ext4 on a ReadyNAS Pro, I now see this issue.
> >  
> > Many Thanks
> > Stephen Elliott
> >  
> > From: Stephen Elliott [mailto:techweb@ntlworld.com]
> > Sent: 23 July 2013 22:02
> > To: linux-ext4@vger.kernel.org; linux-fsdevel@vger.kernel.org; Andreas Dilger (adilger@dilger.ca); 'Bernd Schubert'
> > Subject: RE: FSCK Errors on ext4
> >  
> > If it helps guys, the same file as before is causing the issue with inode 4195610, a very large MS access DB.
> >  
> > From: Stephen Elliott [mailto:techweb@ntlworld.com]
> > Sent: 23 July 2013 21:52
> > To: linux-ext4@vger.kernel.org; linux-fsdevel@vger.kernel.org; Andreas Dilger (adilger@dilger.ca); 'Bernd Schubert'
> > Subject: FSCK Errors on ext4
> >  
> > Hi Andreas / Bernd / all,
> >  
> > You may recall advising me on another batch of FSCK errors a few months back.
> >  
> > The same device on an ext4 file system has produced the following errors after a clean reload. It seems to be fine now but wanted your input on this. No bad blocks are reported on the devices etc.
> >  
> > ***** File system check forced at Tue Jul 23 21:02:13 WEST 2013 ***** fsck 1.42.8 (20-Jun-2013) e2fsck 1.42.8 (20-Jun-2013) Pass 1: Checking inodes, blocks, and sizes Inode 4195619, end of extent exceeds allowed value
> >                 (logical block 64907, physical block 11435403, len 
> > 16) Clear? yes
> >  
> > Inode 4195619, i_blocks is 1337216, should be 1337176.  Fix? yes
> >  
> > Pass 2: Checking directory structure Pass 3: Checking directory 
> > connectivity Pass 4: Checking reference counts Pass 5: Checking 
> > group summary information Block bitmap differences:  
> > -(11435403--11435407) Fix? yes
> >  
> > Free blocks count wrong for group #348 (2130, counted=2135).
> > Fix? yes
> >  
> > Free blocks count wrong (417470107, counted=417470112).
> > Fix? yes
> >  
> >  
> > /dev/c/c: ***** FILE SYSTEM WAS MODIFIED *****
> > /dev/c/c: 625785/30212096 files (13.6% non-contiguous), 
> > 65923424/483393536 blocks
> >  
> > Many Thanks
> > Stephen Elliott
> 
> 
> Cheers, Andreas
> 
> 
> 
> 
> 
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