From 9c8ecb9308d8013ff9ac9d36fdd8ae746033b93c Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Tue, 23 Apr 2024 17:48:43 -0400 Subject: Revert "NFSD: Reschedule CB operations when backchannel rpc_clnt is shut down" The reverted commit attempted to enable NFSD to retransmit pending callback operations if an NFS client disconnects, but unintentionally introduces a hazardous behavior regression if the client becomes permanently unreachable while callback operations are still pending. A disconnect can occur due to network partition or if the NFS server needs to force the NFS client to retransmit (for example, if a GSS window under-run occurs). Reverting the commit will make NFSD behave the same as it did in v6.8 and before. Pending callback operations are permanently lost if the client connection is terminated before the client receives them. For some callback operations, this loss is not harmful. However, for CB_RECALL, the loss means a delegation might be revoked unnecessarily. For CB_OFFLOAD, pending COPY operations will never complete unless the NFS client subsequently sends an OFFLOAD_STATUS operation, which the Linux NFS client does not currently implement. These issues still need to be addressed somehow. Reported-by: Dai Ngo Link: https://bugzilla.kernel.org/show_bug.cgi?id=218735 Signed-off-by: Chuck Lever --- fs/nfsd/nfs4callback.c | 20 ++------------------ 1 file changed, 2 insertions(+), 18 deletions(-) diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c index e440f72b9d4ea..d153af81f4060 100644 --- a/fs/nfsd/nfs4callback.c +++ b/fs/nfsd/nfs4callback.c @@ -986,14 +986,6 @@ static bool nfsd4_queue_cb(struct nfsd4_callback *cb) return queue_delayed_work(callback_wq, &cb->cb_work, 0); } -static void nfsd4_queue_cb_delayed(struct nfsd4_callback *cb, - unsigned long msecs) -{ - trace_nfsd_cb_queue(cb->cb_clp, cb); - queue_delayed_work(callback_wq, &cb->cb_work, - msecs_to_jiffies(msecs)); -} - static void nfsd41_cb_inflight_begin(struct nfs4_client *clp) { atomic_inc(&clp->cl_cb_inflight); @@ -1502,16 +1494,8 @@ nfsd4_run_cb_work(struct work_struct *work) clnt = clp->cl_cb_client; if (!clnt) { - if (test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags)) - nfsd41_destroy_cb(cb); - else { - /* - * XXX: Ideally, we could wait for the client to - * reconnect, but I haven't figured out how - * to do that yet. - */ - nfsd4_queue_cb_delayed(cb, 25); - } + /* Callback channel broken, or client killed; give up: */ + nfsd41_destroy_cb(cb); return; } -- cgit 1.2.3-korg From 8ddb7142c8ab37371c6fd167a8aded97922c6268 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Tue, 23 Apr 2024 17:52:24 -0400 Subject: Revert "NFSD: Convert the callback workqueue to use delayed_work" This commit was a pre-requisite for commit c1ccfcf1a9bf ("NFSD: Reschedule CB operations when backchannel rpc_clnt is shut down"), which has already been reverted. Signed-off-by: Chuck Lever --- fs/nfsd/nfs4callback.c | 6 +++--- fs/nfsd/state.h | 2 +- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c index d153af81f4060..6aff46701aa1a 100644 --- a/fs/nfsd/nfs4callback.c +++ b/fs/nfsd/nfs4callback.c @@ -983,7 +983,7 @@ static struct workqueue_struct *callback_wq; static bool nfsd4_queue_cb(struct nfsd4_callback *cb) { trace_nfsd_cb_queue(cb->cb_clp, cb); - return queue_delayed_work(callback_wq, &cb->cb_work, 0); + return queue_work(callback_wq, &cb->cb_work); } static void nfsd41_cb_inflight_begin(struct nfs4_client *clp) @@ -1482,7 +1482,7 @@ static void nfsd4_run_cb_work(struct work_struct *work) { struct nfsd4_callback *cb = - container_of(work, struct nfsd4_callback, cb_work.work); + container_of(work, struct nfsd4_callback, cb_work); struct nfs4_client *clp = cb->cb_clp; struct rpc_clnt *clnt; int flags; @@ -1528,7 +1528,7 @@ void nfsd4_init_cb(struct nfsd4_callback *cb, struct nfs4_client *clp, cb->cb_msg.rpc_argp = cb; cb->cb_msg.rpc_resp = cb; cb->cb_ops = ops; - INIT_DELAYED_WORK(&cb->cb_work, nfsd4_run_cb_work); + INIT_WORK(&cb->cb_work, nfsd4_run_cb_work); cb->cb_status = 0; cb->cb_need_restart = false; cb->cb_holds_slot = false; diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h index 01c6f34456469..2ed0fcf879fd1 100644 --- a/fs/nfsd/state.h +++ b/fs/nfsd/state.h @@ -68,7 +68,7 @@ struct nfsd4_callback { struct nfs4_client *cb_clp; struct rpc_message cb_msg; const struct nfsd4_callback_ops *cb_ops; - struct delayed_work cb_work; + struct work_struct cb_work; int cb_seq_status; int cb_status; bool cb_need_restart; -- cgit 1.2.3-korg