At 12/05/2016 03:07 PM, Eryu Guan wrote:
On Tue, Nov 22, 2016 at 04:38:08PM +0800, Qu Wenruo wrote:
Despite the scrub test cases in fstests, there is not even one test case
which really checked if scrub can recover data.
In fact, btrfs scrub for RAID56 will even corrupt correct data stripes.
So let's start from the needed facilities and check scrub starting from RAID1.
The main reason the patchset is RFC, is the method I take to corrupt/verify
btrfs data.
unlike other stable fs, like ext* or xfs, which has good tool to
manipulate the fs.
There used to be btrfs-corrupt-block, but it gets fewer and fewer
update, no man page nor installed by default.
I really think that a tool manipulating btrfs should be developed first,
especially it's greatly demanded now and there's already a prototype
btrfs-corrupt-block available. Then this tool can act as a base &
benefit all future tests that corrupt fs metadata. e.g. Darrick
introduced blocktrash command to xfs_db and used it in many fuzz tests.
IMO, let's build and/or fix the tools first. To me, this is just the
right time to do this.
Thanks for the comment.
This idea really helps.
Here I take the method I normally do in my scripts: use btrfs-dump-tree
(btrfs inspect-internal dump-tree) and use bash to corrupt btrfs
pinpointly.
It works quite fine for several different mount options which affects
how data lies on-disk.
But the problem is also obvious, bash script is super hard to maintain,
and there is no promise that btrfs-dump-tree output won't change.
Such change will be destructive.
Agreed, it's very hard to maintain, and, as you pointed out, the output
format changing of btrfs-dump-tree makes the code even harder to read &
maintain. And it's hard to extend to work with other profiles too.
It's really a nightmare debugging the bash script, so I'm quite happy
that I don't need to bother this code anymore.
Add Cc to David to see if he has any better idea on this.
Thanks,
Qu
I'd like to hear what other btrfs developers and fstests users think.
Thanks,
Eryu
But IMHO it's still worthy, or btrfs scrub may break at any time.
Qu Wenruo (3):
fstests: common: rename _require_btrfs to _require_btrfs_subcommand
fstests: common/ondisk.btrfs: Introduce function to get btrfs ondisk
info
fstests: btrfs: Add new test case to check scrub recovery and report
common/ondisk.btrfs | 113 ++++++++++++++++++++++++++
common/rc | 2 +-
tests/btrfs/004 | 2 +-
tests/btrfs/048 | 2 +-
tests/btrfs/059 | 2 +-
tests/btrfs/131 | 2 +-
tests/btrfs/132 | 229 ++++++++++++++++++++++++++++++++++++++++++++++++++++
tests/btrfs/132.out | 111 +++++++++++++++++++++++++
tests/btrfs/group | 2 +
9 files changed, 460 insertions(+), 5 deletions(-)
create mode 100644 common/ondisk.btrfs
create mode 100755 tests/btrfs/132
create mode 100644 tests/btrfs/132.out
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