Re: BTRFS: error (device dm-2) in btrfs_run_delayed_refs:2960: errno=-17 Object already exists (since 3.4 / 2012)

[Marc MERLIN <marc@merlins.org>]

On Sun, Sep 03, 2017 at 03:26:34AM +0000, Josef Bacik wrote:
> I was looking through the code for other ways to cut down memory usage when I noticed we only catch improper re-allocations, not adding another ref for metadata which is what I suspect your problem is.  I added another patch and pushed it out, sorry for the churn.

Installed.

For now, I've seen this once, but otherwise no issues:
Dropping a ref for a root that doesn't have a ref on the block
Dumping block entry [26538725376 4096], num_refs 2, metadata 0, from disk 1
  Ref root 0, parent 29818880, owner 23608, offset 0, num_refs 18446744073709551615
  Ref root 0, parent 202129408, owner 23608, offset 0, num_refs 1
  Ref root 418, parent 0, owner 23608, offset 0, num_refs 1
  Root entry 418, num_refs 1
  Root entry 69809, num_refs 0
  Ref action 1, root 418, ref_root 0, parent 202129408, owner 23608, offset 0, num_refs 1
  No stacktrace support
  Ref action 2, root 69809, ref_root 0, parent 29818880, owner 23608, offset 0, num_refs 18446744073709551615
  No stacktrace support


I'm assuming this was done by your patch?
Should I worry about 'No stacktrace support' ?

Marc
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