Re: mount & fsck of nilfs partition fail.

[Ryusuke Konishi <konishi.ryusuke-Zyj7fXuS5i5L9jVzuh4AOg@public.gmane.org>]

On Thu, 23 Jun 2011 11:21:03 -0700, Zahid Chowdhury wrote:
> Hello Ryusuke,
>   After the new kernel module (2.0.22) the nilfs partition mounted
>   with no problems. I have encountered no problems since then. Doing
>   a lssu(1) does not show segment 759 to be on the list of used
>   segments any further:
> 
> lssu -a /dev/sda2
>               SEGNUM        DATE     TIME STAT     NBLOCKS
>                    0  2011-06-23 10:56:42  -d-        2047
>                    1  2011-06-23 10:56:42  -d-        2048
>                    2  2011-06-23 10:56:42  -d-        2048
>                    3  2011-06-23 10:56:42  -d-        2048
>                    4  2011-06-23 10:56:44  -d-        2048
>                    5  2011-06-23 10:56:46  -d-        2048
>                    7  2011-06-23 10:56:46  -d-        2048
>                    8  2011-06-23 10:56:47  -d-        2048
>                    9  2011-06-23 10:56:47  -d-        2048
>                   10  2011-06-23 10:56:47  -d-        2048
>                   11  2011-06-23 10:56:47  -d-        2048
>                   12  2011-06-23 10:56:47  -d-        2048
>                   13  2011-06-23 10:56:52  -d-        2048
>                   14  2011-06-23 10:56:52  -d-        2048
>                   16  2011-06-23 10:56:52  -d-        2048
>                   17  2011-06-23 10:56:52  -d-        2048
>                   18  2011-06-23 10:56:52  -d-        2048
>                   19  2011-06-23 10:56:53  -d-        2048
p>                   20  2011-06-23 10:56:54  ad-        1273
>                   21  ---------- --:--:--  ad-           0
>                  946  2011-06-23 10:52:27  -d-        2048
>                  947  2011-06-23 10:52:28  -d-        2048
>                  948  2011-06-23 10:52:28  -d-        2048
>                  949  2011-06-23 10:52:28  -d-        2048
> 			.
> 			.
> 			.
> Though dumpseg 759 does not show anything untoward (I don't think its used any further, correct?):
> 
> dumpseg /dev/sda2 759
> segment: segnum = 759
>   sequence number = 608068, next segnum = 760
>   partial segment: blocknr = 1554432, nblocks = 2048
>     creation time = 2011-06-23 10:48:02
>     nfinfo = 652
>     finfo
>       ino = 7984, cno = 13, nblocks = 756, ndatblk = 756
>         vblocknr = 146359, blkoff = 30686, blocknr = 1554444
>         vblocknr = 146360, blkoff = 30687, blocknr = 1554445
> 		.
> 		.
> 		.
>     finfo
>       ino = 16619, cno = 3763620, nblocks = 2, ndatblk = 2
>         vblocknr = 224656, blkoff = 304, blocknr = 1555200
>         vblocknr = 224635, blkoff = 305, blocknr = 1555201
>     finfo
>       ino = 16619, cno = 3763616, nblocks = 1, ndatblk = 1
>         vblocknr = 224551, blkoff = 303, blocknr = 1555202
> 		.
> 		.
> 		.

Hmm, the segment looks to be overwritten with new data after the
partition was successfully mounted.  I don't know if it's certainly
safe now, but It might be needless fear.

> One other question I have for anybody on the list or Ryusuke, on a
> corruption of nilfs on older kernels (pre 2.6.30) should I leave
> fsck0.nilfs2 to run on the initscripts besides the new 2.0.22 kernel
> module or is this really redundant? Thanks for any
> help/comments. All, as far as I can see, this is a pretty cool
> filesystem.

For now, fsck0.nilfs2 is just a manual rollback tool.  There is no
merit to run it from initscripts since it doesn't verify filesystem
consistency.  ( Clearly, making a true fsck is one of TODO items. )

As for fsck0.nilfs2, you only have to use it when you couldn't mount
the partition.  I hope this never happens for the 2.0.22 module.

Thanks for your interest and help.

Regards,
Ryusuke Konishi


> Zahid 
> 
> -----Original Message-----
> From: Ryusuke Konishi [mailto:konishi.ryusuke-Zyj7fXuS5i5L9jVzuh4AOg@public.gmane.org] 
> Sent: Thursday, June 23, 2011 4:25 AM
> To: Zahid Chowdhury
> Cc: linux-nilfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> Subject: Re: mount & fsck of nilfs partition fail.
> 
> On Mon, 20 Jun 2011 11:27:49 -0700, Zahid Chowdhury wrote:
> > Hello Ryusuke,
> >
> >   Sorry, I was away on the w/e. I've attached the console trace and
> >   the out file again for posterity. I will be upgrading to the
> >   recently released 2.0.22 version, and will try to mount the
> >   corrupted filesystem with it - unlikely, it will work, though it
> >   should help on future filesystems based on nilfs2? Thanks for the
> >   fsck help and the new release for older kernels. Please let me
> >   know if you need anything further, such that I can recover the
> >   corrupted filesystem.
> >
> > Zahid
> > 
> > The console trace:
> > /sbin/fsck0.nilfs2 -f -v /dev/sda2
> > Super-block:
> >     revision = 2.0
> >     blocksize = 4096
> >     write time = 2011-06-11 23:22:03
> >     indicated log: blocknr = 1648528
> >         segnum = 804, seq = 401758, cno=3250953
> > 
> > Unclean FS.
> > The latest log is lost. Trying rollback recovery..
> > ......
> > Searching the latest checkpoint.
> > get_latest_cno: log_start=1556429 (segnum=759): nfinfo=6, fblocknr=1556430
> > get_latest_cno: finfo: ino=17874, sum-blocknr=1556429, offset=80, nblocks=2, ndatablk=1, fblocknr=1556430
> > get_latest_cno: finfo: ino=17875, sum-blocknr=1556429, offset=128, nblocks=1, ndatablk=1, fblocknr=1556432
> > get_latest_cno: finfo: ino=6, sum-blocknr=1556429, offset=168, nblocks=2, ndatablk=1, fblocknr=1556433
> > get_latest_cno: finfo: ino=4, sum-blocknr=1556429, offset=216, nblocks=3, ndatablk=2, fblocknr=1556435
> > get_latest_cno: finfo: ino=4499, sum-blocknr=1556429, offset=280, nblocks=1306282328, ndatablk=0, fblocknr=1556438
> 
> According to this log, the summary information of segment #759 looks
> broken.  This may cause future GC failure or filesystem corruption.
> 
> Could you confirm whether the segment summary is actually broken or
> not ?  This can be done with dumpseg tool:
> 
>  # dumpseg /dev/sda2 759
> 
> If it looks actually broken, I recommend you to back up all data as
> soon as possible.
> 
> Regards,
> Ryusuke Konishi
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