Re: kernel trace, (nearly) every time on send/receive

[Christoph Anton Mitterer <calestyo@scientia.net>]

Hey Anand.

Thanks for looking into this.

On Mon, 2019-12-02 at 10:58 +0800, Anand Jain wrote:
> Looks like ORPHAN_CLEANUP_DONE is not set on the root.
> 
>          WARN_ON(send_root->orphan_cleanup_state !=
> ORPHAN_CLEANUP_DONE);
> 
> ORPHAN_CLEANUP_DONE is set unless it is a readonly FS, which I doubt
> is,
> (can be checked using btrfs inspect duper-super <dev>) because you
> are
> creating the snapshot for the send.

I should perhaps add, that there are two btrfs filesystems involved
here:
The first is basically the master, having several snapshots including
all + one newer which is missing from the second (which is basically a
backup of the master).

So it's about:
/master# btrfs send -p already-on-copy newer-snapshot | btrfs receive /copy/snapshots/ ; 

In fact /master is mounted ro only here, whereas /copy is of course
mounted rw.
Since nothing should be changed on /master I assumed it would be ok to
have it mounted ro.


>  btrfs check --readonly might tell
> us more about the issue.

I cannot do this right now since I'll be on some diving vacation for ~2
weeks,... but since --readonly is the standard behaviour (i.e. same
without --readonly) I'm pretty sure that a fsck (which I always do
after each snapshot to the /copy) brought now visible errors.


Does the whole thing imply any corruption to any of the two
filesystems... or is it just a "cosmetic" issue?


Cheers,
Chris