From aa0ebd21df9c90a69f8bf00e3fa49d476be8e290 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Thu, 31 Oct 2024 09:40:08 -0400 Subject: [PATCH] NFSD: Add nfsd4_copy time-to-live Keep async copy state alive for a few lease cycles after the copy completes so that OFFLOAD_STATUS returns something meaningful. This means that NFSD's client shutdown processing needs to purge any of this state that happens to be waiting to die. Reviewed-by: Jeff Layton Signed-off-by: Chuck Lever --- fs/nfsd/nfs4proc.c | 7 +++++-- fs/nfsd/state.h | 15 +++++++++++++++ fs/nfsd/xdr4.h | 1 + 3 files changed, 21 insertions(+), 2 deletions(-) diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c index dfc118bf9aa5d3..f8a10f90bc7a4b 100644 --- a/fs/nfsd/nfs4proc.c +++ b/fs/nfsd/nfs4proc.c @@ -1326,8 +1326,10 @@ void nfsd4_async_copy_reaper(struct nfsd_net *nn) list_for_each_safe(pos, next, &clp->async_copies) { copy = list_entry(pos, struct nfsd4_copy, copies); if (test_bit(NFSD4_COPY_F_OFFLOAD_DONE, ©->cp_flags)) { - list_del_init(©->copies); - list_add(©->copies, &reaplist); + if (--copy->cp_ttl) { + list_del_init(©->copies); + list_add(©->copies, &reaplist); + } } } spin_unlock(&clp->async_lock); @@ -1921,6 +1923,7 @@ nfsd4_copy(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, async_copy->cp_nn = nn; INIT_LIST_HEAD(&async_copy->copies); refcount_set(&async_copy->refcount, 1); + async_copy->cp_ttl = NFSD_COPY_INITIAL_TTL; /* Arbitrary cap on number of pending async copy operations */ if (atomic_inc_return(&nn->pending_async_copies) > (int)rqstp->rq_pool->sp_nrthreads) diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h index dcbebd53e5f409..8092894e8f3cdd 100644 --- a/fs/nfsd/state.h +++ b/fs/nfsd/state.h @@ -137,6 +137,21 @@ struct nfs4_cpntf_state { time64_t cpntf_time; /* last time stateid used */ }; +/* + * RFC 7862 Section 4.8 states: + * + * | A copy offload stateid will be valid until either (A) the client + * | or server restarts or (B) the client returns the resource by + * | issuing an OFFLOAD_CANCEL operation or the client replies to a + * | CB_OFFLOAD operation. + * + * Because a client might not reply to a CB_OFFLOAD, or a reply + * might get lost due to connection loss, NFSD purges async copy + * state after a short period to prevent it from accumulating + * over time. + */ +#define NFSD_COPY_INITIAL_TTL 10 + struct nfs4_cb_fattr { struct nfsd4_callback ncf_getattr; u32 ncf_cb_status; diff --git a/fs/nfsd/xdr4.h b/fs/nfsd/xdr4.h index 5951360f6d0393..382cc138939655 100644 --- a/fs/nfsd/xdr4.h +++ b/fs/nfsd/xdr4.h @@ -715,6 +715,7 @@ struct nfsd4_copy { struct list_head copies; struct task_struct *copy_task; refcount_t refcount; + unsigned int cp_ttl; struct nfsd4_ssc_umount_item *ss_nsui; struct nfs_fh c_fh;