6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Lubos Rendek [ There is no upstream commit: this fixes the 6.18.y backport of d0beaee498e1. Mainline fixed the problem as part of the async COPY rework in commit f307b4f7ed17 ("nfsd: split nfsd4_copy into transient and durable async copy objects"), which is too risky to backport. ] Since commit 9b4e5e9ba5ae ("nfsd: fix stale s2s_cp_stateids IDR entry for async COPY"), nfsd4_copy() calls dup_copy_fields() before the copy stateid is created and then writes the new stateid only into the COPY result. The async copy's own cp_res.cb_stateid stays zero, so nfsd4_send_cb_offload() sends CB_OFFLOAD with an all-zero stateid. The client cannot match it to its pending COPY and waits forever in nfs42_proc_copy(). Also copy the new stateid into async_copy->cp_res.cb_stateid. Calling dup_copy_fields() after nfs4_init_copy_state() instead is not an option, because dup_copy_fields() also copies cp_stateid and would overwrite the stateid that the backport moved to the async copy. Tested on 6.18.56 with an NFSv4.2 server-side COPY between two exports: with this change the copy completes and CB_OFFLOAD carries the same stateid as the COPY reply. Without it, cp(1) hangs on 6.18.55; the affected code in nfsd4_copy() is the same in 6.18.56. Fixes: 9b4e5e9ba5ae ("nfsd: fix stale s2s_cp_stateids IDR entry for async COPY") Closes: https://lore.kernel.org/stable/7cc824c4-632d-49df-ae5e-cfcbb5bf76ad@proxmox.com/ Assisted-by: Claude:claude-opus-5-5 Signed-off-by: Lubos Rendek Signed-off-by: Sasha Levin --- fs/nfsd/nfs4proc.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c index 898aaeea2059a..864eebb1f0760 100644 --- a/fs/nfsd/nfs4proc.c +++ b/fs/nfsd/nfs4proc.c @@ -2084,6 +2084,8 @@ nfsd4_copy(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, goto out_dec_async_copy_err; memcpy(&result->cb_stateid, &async_copy->cp_stateid.cs_stid, sizeof(result->cb_stateid)); + memcpy(&async_copy->cp_res.cb_stateid, &async_copy->cp_stateid.cs_stid, + sizeof(async_copy->cp_res.cb_stateid)); if ((READ_ONCE(copy->nf_dst->nf_file->f_mode) & FMODE_NOCMTIME) != 0) async_copy->attr_update = true; -- 2.53.0