Re: [PATCH] xfs/097: Remove wrong broken assignment operation

["Darrick J. Wong" <darrick.wong@oracle.com>]

On Mon, Oct 21, 2019 at 08:09:39PM +0800, Yang Xu wrote:
> 
> 
>  on 2019/10/15 14:27, Yang Xu wrote:
> > 
> > 
> > on 2019/10/15 0:39, Darrick J. Wong wrote:
> > > On Tue, Oct 08, 2019 at 10:39:59AM +0800, Yang Xu wrote:
> > > > 
> > > > 
> > > > on 2019/10/07 23:12, Darrick J. Wong wrote:
> > > > > On Mon, Oct 07, 2019 at 03:15:15PM +0800, Yang Xu wrote:
> > > > > > On old kernel, since commit ded188b8609 ("xfs: Fix the
> > > > > > situation that mount
> > > > > > operation rejects corrupted XFS") running this case got
> > > > > > the mismatched output,
> > > > > > as below:
> > > > > 
> > > > > But why did the output mismatch?  Did the fs heal itself?  Did
> > > > > allocating 5 more files somehow avoid touching the finobt?  Is the
> > > > > assignment logic in the loop broken?
> > > > 
> > > > The output mismatch because on old kernel, we can mount the
> > > > corrupted xfs
> > > > and touch action will be refused. so broken is equal to 0.
> > > > The fs doesn't heal ifself.
> > > > allocating 5 more file will touch the finobt.
> > > > 
> > > > You can see this url
> > > > https://git.kernel.org/pub/scm/fs/xfs/xfstests-dev.git/commit/?id=ded188b86096e2845e59dedae6050c7f254a96b
> > > > 
> > > > 
> > > > eg xfs/087, they all delete "broken=0" before allocationg 5 more file.
> > > > commit ded188b86 compatibled old kernel(permit mount and refuse
> > > > touch) and
> > > > new kernel(refuse mount) behavior on corrupted xfs.  Or, I misunderstand
> > > > this case?
> > > 
> > > How old is the kernel?  At some point (4.10, I think?) we added a patch
> > > to reserve metadata blocks for future free inode btree expansion.  That
> > > required us to count the blocks in the finobt, at which point xfs/097's
> > > behavior changed such that the fs doesn't mount after the test corrupts
> > > the finobt.
> > I test this case on kernel-3.10.0-1062.el7.x86_64.
> > I find the patch you said to reserve metadata blocks for future free
> > inode btree expansion. This kernel doesn't backport this commit 76d771b4
> > ("xfs: use per-AG reservations for the finobt"), so it permmits to
> > mount.
> > 
> > I can understand your meaning. But from xfstests commit ded188b86, it
> > looks like refuse touch or refuse mount is acceptable for xfstests.
> > 
> > Also, xfs/087 is a similar case but it sets broken=1 instead of broken
> > =0.  Before this kernel commit 76d771b4, xfs/087(xfs/097) permits mount
> > and refuse touch, after this commit, xfs/087(xfs/097) refuses mount.
> > I think we should keep xfs/097 consistent with xfs/087. What do you
> > think about it?
> > 
> > ps:my patch is intend to fix the inconsistent of broken assignment
> > operation that xfstests commit ded188b86 introduced.
> Hi Darrick
>   Do you have some questions on this patch?

Does it still pass on upstreeam 5.4?

--D

> Hi Eryu
>    What do you think about this patch(I only want to keep xfs/097 consistent
> with xfs/087).
> > 
> > Thanks
> > Yang Xu
> > 
> > > 
> > > --D
> > > 
> > > > > 
> > > > > --D
> > > > > 
> > > > > > -----------------------------------
> > > > > >    + check fs
> > > > > >    + corrupt image
> > > > > >    + mount image && modify files
> > > > > > -broken: 1
> > > > > > +broken: 0
> > > > > >    + repair fs
> > > > > >    + mount image (2)
> > > > > > ------------------------------------
> > > > > > 
> > > > > > It fails because the broken is always equal to 0 when
> > > > > > _try_scratch_mount
> > > > > > succeed. So remove this wrong assignment operation.
> > > > > > 
> > > > > > Signed-off-by: Yang Xu <xuyang2018.jy@cn.fujitsu.com>
> > > > > > ---
> > > > > >    tests/xfs/097 | 2 --
> > > > > >    1 file changed, 2 deletions(-)
> > > > > > 
> > > > > > diff --git a/tests/xfs/097 b/tests/xfs/097
> > > > > > index 1cb7d69c..20791738 100755
> > > > > > --- a/tests/xfs/097
> > > > > > +++ b/tests/xfs/097
> > > > > > @@ -81,8 +81,6 @@ done
> > > > > >    echo "+ mount image && modify files"
> > > > > >    broken=1
> > > > > >    if _try_scratch_mount >> $seqres.full 2>&1; then
> > > > > > -
> > > > > > -    broken=0
> > > > > >        for x in `seq 65 70`; do
> > > > > >            touch "${TESTFILE}.${x}" 2> /dev/null && broken=0
> > > > > >        done
> > > > > > -- 
> > > > > > 2.18.1
> > > > > > 
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