Re: [PATCH 1/1] NFSD: free copynotify stateid in nfs4_free_ol_stateid()

[Chuck Lever <chuck.lever@oracle.com>]

On 10/14/25 2:20 PM, Olga Kornievskaia wrote:
> On Tue, Oct 14, 2025 at 2:05 PM Chuck Lever <chuck.lever@oracle.com> wrote:
>>
>> On 10/14/25 1:59 PM, Olga Kornievskaia wrote:
>>> Typically copynotify stateid is freed either when parent's stateid
>>> is being close/freed or in nfsd4_laundromat if the stateid hasn't
>>> been used in a lease period.
>>>
>>> However, in case when the server got an OPEN (which created
>>> a parent stateid), followed by a COPY_NOTIFY using that stateid,
>>> followed by a client reboot. New client instance while doing
>>> CREATE_SESSION would force expire previous state of this client.
>>> It leads to the open state being freed thru release_openowner->
>>> nfs4_free_ol_stateid() and it finds that it still has copynotify
>>> stateid associated with it. We currently print a warning and is
>>> triggerred
>>>
>>> WARNING: CPU: 1 PID: 8858 at fs/nfsd/nfs4state.c:1550 nfs4_free_ol_stateid+0xb0/0x100 [nfsd]
>>>
>>> This patch, instead, frees the associated copynotify stateid here.
>>>
>>> If the parent stateid is freed (without freeing the copynotify
>>> stateids associated with it), it leads to the list corruption
>>> when laundromat ends up freeing the copynotify state later.
>>>
>>> [ 1626.839430] Internal error: Oops - BUG: 00000000f2000800 [#1]  SMP
>>> [ 1626.842828] Modules linked in: nfnetlink_queue nfnetlink_log bluetooth cfg80211 rpcrdma rdma_cm iw_cm ib_cm ib_core nfsd nfs_acl lockd grace nfs_localio ext4 crc16 mbcache jbd2 overlay uinput snd_seq_dummy snd_hrtimer qrtr rfkill vfat fat uvcvideo snd_hda_codec_generic videobuf2_vmalloc videobuf2_memops snd_hda_intel uvc snd_intel_dspcfg videobuf2_v4l2 videobuf2_common snd_hda_codec snd_hda_core videodev snd_hwdep snd_seq mc snd_seq_device snd_pcm snd_timer snd soundcore sg loop auth_rpcgss vsock_loopback vmw_vsock_virtio_transport_common vmw_vsock_vmci_transport vmw_vmci vsock xfs 8021q garp stp llc mrp nvme ghash_ce e1000e nvme_core sr_mod nvme_keyring nvme_auth cdrom vmwgfx drm_ttm_helper ttm sunrpc dm_mirror dm_region_hash dm_log iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi fuse dm_multipath dm_mod nfnetlink
>>> [ 1626.855594] CPU: 2 UID: 0 PID: 199 Comm: kworker/u24:33 Kdump: loaded Tainted: G    B   W           6.17.0-rc7+ #22 PREEMPT(voluntary)
>>> [ 1626.857075] Tainted: [B]=BAD_PAGE, [W]=WARN
>>> [ 1626.857573] Hardware name: VMware, Inc. VMware20,1/VBSA, BIOS VMW201.00V.24006586.BA64.2406042154 06/04/2024
>>> [ 1626.858724] Workqueue: nfsd4 laundromat_main [nfsd]
>>> [ 1626.859304] pstate: 61400005 (nZCv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--)
>>> [ 1626.860010] pc : __list_del_entry_valid_or_report+0x148/0x200
>>> [ 1626.860601] lr : __list_del_entry_valid_or_report+0x148/0x200
>>> [ 1626.861182] sp : ffff8000881d7a40
>>> [ 1626.861521] x29: ffff8000881d7a40 x28: 0000000000000018 x27: ffff0000c2a98200
>>> [ 1626.862260] x26: 0000000000000600 x25: 0000000000000000 x24: ffff8000881d7b20
>>> [ 1626.862986] x23: ffff0000c2a981e8 x22: 1fffe00012410e7d x21: ffff0000920873e8
>>> [ 1626.863701] x20: ffff0000920873e8 x19: ffff000086f22998 x18: 0000000000000000
>>> [ 1626.864421] x17: 20747562202c3839 x16: 3932326636383030 x15: 3030666666662065
>>> [ 1626.865092] x14: 6220646c756f6873 x13: 0000000000000001 x12: ffff60004fd9e4a3
>>> [ 1626.865713] x11: 1fffe0004fd9e4a2 x10: ffff60004fd9e4a2 x9 : dfff800000000000
>>> [ 1626.866320] x8 : 00009fffb0261b5e x7 : ffff00027ecf2513 x6 : 0000000000000001
>>> [ 1626.866938] x5 : ffff00027ecf2510 x4 : ffff60004fd9e4a3 x3 : 0000000000000000
>>> [ 1626.867553] x2 : 0000000000000000 x1 : ffff000096069640 x0 : 000000000000006d
>>> [ 1626.868167] Call trace:
>>> [ 1626.868382]  __list_del_entry_valid_or_report+0x148/0x200 (P)
>>> [ 1626.868876]  _free_cpntf_state_locked+0xd0/0x268 [nfsd]
>>> [ 1626.869368]  nfs4_laundromat+0x6f8/0x1058 [nfsd]
>>> [ 1626.869813]  laundromat_main+0x24/0x60 [nfsd]
>>> [ 1626.870231]  process_one_work+0x584/0x1050
>>> [ 1626.870595]  worker_thread+0x4c4/0xc60
>>> [ 1626.870893]  kthread+0x2f8/0x398
>>> [ 1626.871146]  ret_from_fork+0x10/0x20
>>> [ 1626.871422] Code: aa1303e1 aa1403e3 910e8000 97bc55d7 (d4210000)
>>> [ 1626.871892] SMP: stopping secondary CPUs
>>>
>>
>> Reported-by: <rtm@csail.mit.edu>
>> Closes:
>> https://lore.kernel.org/linux-nfs/d8f064c1-a26f-4eed-b4f0-1f7f608f415f@oracle.com/T/#t
>> Cc: stable@vger.kernel.org
>>
> 
> To clarify, you want v2 with these lines added?

The additional tags in this email thread are picked up when I import
your patch. No need for a v2 unless reviewers ask for substantive
changes.


> (do you want me to add "cc: stable" too)?

As the policy document states, please don't add "Cc: stable". The
maintainers do that part.


>>> Fixes: 624322f1adc5 ("NFSD add COPY_NOTIFY operation")
>>> Signed-off-by: Olga Kornievskaia <okorniev@redhat.com>
>>> ---
>>>  fs/nfsd/nfs4state.c | 3 ++-
>>>  1 file changed, 2 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
>>> index 1c01836e8507..c197438765db 100644
>>> --- a/fs/nfsd/nfs4state.c
>>> +++ b/fs/nfsd/nfs4state.c
>>> @@ -1542,7 +1542,8 @@ static void nfs4_free_ol_stateid(struct nfs4_stid *stid)
>>>       release_all_access(stp);
>>>       if (stp->st_stateowner)
>>>               nfs4_put_stateowner(stp->st_stateowner);
>>> -     WARN_ON(!list_empty(&stid->sc_cp_list));
>>> +     if (!list_empty(&stid->sc_cp_list))
>>> +             nfs4_free_cpntf_statelist(stid->sc_client->net, stid);
>>>       kmem_cache_free(stateid_slab, stid);
>>>  }
>>>
>>
>>
>> --
>> Chuck Lever
>>


-- 
Chuck Lever