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
