-------- Original Message --------
Subject: Re: [PATCH 1/2] btrfs-progs: Add support for btrfs-image +
corrupt script fsck test case.
From: Dave Chinner <david@xxxxxxxxxxxxx>
To: Filipe David Manana <fdmanana@xxxxxxxxx>
Date: 2014年12月24日 08:03
[ Sorry to take some time to get to this, it got caught by a spam
filter and I only just noticed. ]
On Tue, Dec 16, 2014 at 02:08:53PM +0000, Filipe David Manana wrote:
On Tue, Dec 16, 2014 at 1:35 AM, Qu Wenruo <quwenruo@xxxxxxxxxxxxxx> wrote:
-------- Original Message --------
Subject: Re: [PATCH 1/2] btrfs-progs: Add support for btrfs-image + corrupt
script fsck test case.
From: David Sterba <dsterba@xxxxxxx>
To: Filipe David Manana <fdmanana@xxxxxxxxx>
Date: 2014年12月16日 02:19
On Mon, Dec 15, 2014 at 10:13:45AM +0000, Filipe David Manana wrote:
So another thing I would like to see is doing a more comprehensive
verification that the repair code worked as expected. Currently we
only check that a readonly fsck, after running fsck --repair, returns
0.
For the improvements you've been doing, it's equally important to
verify that --repair recovered the inodes, links, etc to the
lost+found directory (or whatever is the directory's name).
So perhaps adding a verify.sh script to the tarball for example?
Or, forgot before, it might be better to do such verification/test in
xfstests since we can create the fs and use the new btrfs-progs
programs to corrupt leafs/nodes. xfstests has a lot of infrastructure
already and probably run by a lot more people (compared to the fsck
tests of btrfs-progs).
I'm thinking about the best way how to integrate that, but it seems that
there will be always some level of code or infrastructure duplication
(or other hassle).
btrfs-corrupt-block is not installed by default (make install) and it's
not a type of utility I'd consider for default installations. The tests
would be skipped in absence of the utility, so there will be test
environments where "install xfstests, install btrfspprogs" will not add
the desired test coverage. Solvable by packaging the extra progs.
Adding corrupt-block into xfsprogs is infeasible (IMO too much code from
btrfs-progs to be added).
I don't know how much infrastructure code we'd have to either write or
copy from fstests, but I think it would not be that much. Ideally we
could write the tests within btrfs-progs and then submit them to fstests
once they're considered reliable. If we keep the same "syntax" of the
tests, provide stubs where applicable, the code duplication in test
itself would be zero. We'd only have to write the stubs in btrfs-progs
and probably extend fstests to provide helpers for preparing/unpacking
the images.
In my wildest idea, if we have a good enough btrfs debugger(maybe even
stronger than debugfs), which can
do almost everything from read key/item to corrupt given structure, then we
can resolve them all.
No binary image since corruption can be done by it and verify can also done
by it.
(OK, it's just a daydream)
But IMHO, isn't xfstests designed to mainly detect kernel defeats?
I don't see any fsck tool test case in it.
I don't think xfstests is specific to test the kernel implementation
of filesystems. I believe it includes user space code too, but I might
be wrong so I'm CCing fstests and Dave to get an authoritative answer.
We use fstests to test everything we ship for XFS - kernel and
userspace. i.e. we have tests that corrupt filesystems with xfs_db
and then test that xfs_repair can fix them, and once fixed the
filesystem can be mounted and used by the kernel...
i.e. fstests is for testing both the kernel code and the utilities
used to manipulate filesystems.
That's great.
But what will happen if some btrfs cases need binary(still huge even
compressed) or
btrfs-image dump(some existing dumps are already several MB)?
Will it be OK for fstests?
Or should we wait until btrfs-progs has a good debug tools like xfs_db
or debugfs and use
them to generate the corrupted image like xfs testcases do?
Thanks,
Qu
And I don't see a big problem with btrfs-corrupt not being built by
default when running "make" on btrfs-progs. We can make the xfstest
not run and print an informative message if the btrfs-corrupt program
isn't available - several xfstests do this, they require some
executable which isn't either in the xfstests nor xfsprogs
repositories - for example generic/241 which requires 'dbench' and
generic/299 which requires 'fio'.
_require_btrfs_corrupt_prog()
Just like we do with lots of other optional userspace tools that are
required for various tests to run.
I also have a slight preference to get all
tests in the same place (xfstests) rather than in multiple
repositories (btrfs-progs, xfstests).
Definitely my preference as well.
Cheers,
Dave.
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