Re: oops from deliberate block trashing (of course!)

["Michael L. Semon" <mlsemon35@xxxxxxxxx>]

On 03/28/2013 02:14 AM, Dave Chinner wrote:
> On Thu, Mar 28, 2013 at 01:18:24AM -0400, Michael L. Semon wrote:
> > ==== SECOND OOPS: xfs_db blocktrash test
> >
> > root@oldsvrhw:~# xfs_db -x /dev/sdb2
> > xfs_db> blockget
> > xfs_db> blocktrash -n 10240 -s 755366564 -3 -x 1 -y 16
> > blocktrash: 0/17856 inode block 6 bits starting 423:0 randomized
> > [lots of blocktrash stuff removed but still available]
> > blocktrash: 3/25387 dir block 2 bits starting 1999:1 randomized
> > xfs_db> quit
> > root@oldsvrhw:~# mount /dev/sdb2 /mnt/hole-test/
> > root@oldsvrhw:~# cd /mnt/hole-test/
> > root@oldsvrhw:/mnt/hole-test# find . -type f
> >
> > XFS (sdb2): Mounting Filesystem
> > XFS (sdb2): Ending clean mount
> > XFS (sdb2): Invalid inode number 0x40000000800084
> > XFS (sdb2): Internal error xfs_dir_ino_validate at line 160 of file
> > fs/xfs/xfs_dir2.c.  Caller 0xc12b9d0d
> >
> > Pid: 97, comm: kworker/0:1H Not tainted 3.9.0-rc1+ #1
> > Call Trace:
> >   [<c1270cbb>] xfs_error_report+0x4b/0x50
> >   [<c12b9d0d>] ? __xfs_dir3_data_check+0x3cd/0x710
> >   [<c12b6326>] xfs_dir_ino_validate+0xb6/0x180
> >   [<c12b9d0d>] ? __xfs_dir3_data_check+0x3cd/0x710
> >   [<c12b9d0d>] __xfs_dir3_data_check+0x3cd/0x710
> >   [<c105ffe8>] ? update_curr.constprop.41+0xa8/0x180
> >   [<c12b7289>] xfs_dir3_block_verify+0x89/0xa0
> And here we validating a different directory block, and finding that
> the inode number it points to is invalid. So, same thing - debug
> kernel fires an assert, production kernel returns EFSCORRUPTED.
>
> What you are seeing is that the verifiers are doing their job as
> intended - catching corruption that is on disk as soon as we
> possibly can. i.e. before it has the chance of being propagated
> further.
>
> Cheers,
>
> Dave.
Very good!  It's good to learn that all of those verifiers are doing 
their jobs...that the ASSERTs all have some kind of dedicated 
purpose...and that I shouldn't face this in non-debug mode.
These proof-positve crash reports are excellent.  I just wish I knew how 
to make them on purpose.
Thanks again, Dave.

Michael