Re: nfsd: radix tree warning in nfs4_put_stid and kernel panic

[ChenXiaoSong]

Greetings,

Have you fixed this issue [1]? The identical issue on Ubuntu [2] seems 
to have been fixed in tag v5.3-rc5, and patch [3] was committed in 
v5.5-rc1, so does patch [4](was committed in v5.1-rc7) seem more likely 
to fix the issue? Or is there other patch that can fix it?

Thanks,
ChenXiaoSong.

[1] https://lore.kernel.org/all/76C32636621C40EC87811F625761F2AF@alyakaslap/

[2] https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1840650

[3] 2bbfed98a4d8 nfsd: Fix races between nfsd4_cb_release() and 
nfsd4_shutdown_callback()

[4] e6abc8caa6de nfsd: Don't release the callback slot unless it was 
actually held

在 2020/6/28 17:07, Alex Lyakas 写道:

> I checked the git log, and found 2 commits that might be relevant [1]
> and [2], [2] seems more relevant. However, I don't have any evidence
> that in my case client was actually being destroyed, causing double
> free of a stateid.
>
> Thanks,
> Alex.
>
> [1]
> commit e6abc8caa6deb14be2a206253f7e1c5e37e9515b
> Author: Trond Myklebust <trondmy@xxxxxxxxx>
> Date:   Fri Apr 5 08:54:37 2019 -0700
>
>      nfsd: Don't release the callback slot unless it was actually held
>
>      If there are multiple callbacks queued, waiting for the callback
>      slot when the callback gets shut down, then they all currently
>      end up acting as if they hold the slot, and call
>      nfsd4_cb_sequence_done() resulting in interesting side-effects.
>
>      In addition, the 'retry_nowait' path in nfsd4_cb_sequence_done()
>      causes a loop back to nfsd4_cb_prepare() without first freeing the
>      slot, which causes a deadlock when nfsd41_cb_get_slot() gets called
>      a second time.
>
>      This patch therefore adds a boolean to track whether or not the
>      callback did pick up the slot, so that it can do the right thing
>      in these 2 cases.
>
>      Cc: stable@xxxxxxxxxxxxxxx
>      Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
>      Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxx>
>
>
> [2]
> commit 2bbfed98a4d82ac4e7abfcd4eba40bddfc670b1d
> Author: Trond Myklebust <trondmy@xxxxxxxxx>
> Date:   Wed Oct 23 17:43:18 2019 -0400
>
>      nfsd: Fix races between nfsd4_cb_release() and nfsd4_shutdown_callback()
>
>      When we're destroying the client lease, and we call
>      nfsd4_shutdown_callback(), we must ensure that we do not return
>      before all outstanding callbacks have terminated and have
>      released their payloads.
>
>      Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
>      Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxx>