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| author |   Chuck Lever <chuck.lever@oracle.com> | 2020-04-17 12:40:31 -0400 |
|---|---|---|
| committer | Chuck Lever <chuck.lever@oracle.com> | 2020-04-17 12:40:31 -0400 |
| commit | 6221f1d9b63fed6260273e59a2b89ab30537a811 (patch) | |
| tree | 698698f228e81683fe292982fffca41181618881 /fs/nfsd/nfs4callback.c | |
| parent | SUNRPC/cache: Fix unsafe traverse caused double-free in cache_purge (diff) | |
| download | linux-dev-6221f1d9b63fed6260273e59a2b89ab30537a811.tar.xz linux-dev-6221f1d9b63fed6260273e59a2b89ab30537a811.zip | |
SUNRPC: Fix backchannel RPC soft lockups
Currently, after the forward channel connection goes away,
backchannel operations are causing soft lockups on the server
because call_transmit_status's SOFTCONN logic ignores ENOTCONN.
Such backchannel Calls are aggressively retried until the client
reconnects.
Backchannel Calls should use RPC_TASK_NOCONNECT rather than
RPC_TASK_SOFTCONN. If there is no forward connection, the server is
not capable of establishing a connection back to the client, thus
that backchannel request should fail before the server attempts to
send it. Commit 58255a4e3ce5 ("NFSD: NFSv4 callback client should
use RPC_TASK_SOFTCONN") was merged several years before
RPC_TASK_NOCONNECT was available.
Because setup_callback_client() explicitly sets NOPING, the NFSv4.0
callback connection depends on the first callback RPC to initiate
a connection to the client. Thus NFSv4.0 needs to continue to use
RPC_TASK_SOFTCONN.
Suggested-by: Trond Myklebust <trondmy@hammerspace.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: <stable@vger.kernel.org> # v4.20+
Diffstat (limited to 'fs/nfsd/nfs4callback.c')
| -rw-r--r-- | fs/nfsd/nfs4callback.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c index c3b11a715082..5cf91322de0f 100644 --- a/fs/nfsd/nfs4callback.c +++ b/fs/nfsd/nfs4callback.c @@ -1312,6 +1312,7 @@ nfsd4_run_cb_work(struct work_struct *work) container_of(work, struct nfsd4_callback, cb_work); struct nfs4_client *clp = cb->cb_clp; struct rpc_clnt *clnt; + int flags; if (cb->cb_need_restart) { cb->cb_need_restart = false; @@ -1340,7 +1341,8 @@ nfsd4_run_cb_work(struct work_struct *work) } cb->cb_msg.rpc_cred = clp->cl_cb_cred; - rpc_call_async(clnt, &cb->cb_msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN, + flags = clp->cl_minorversion ? RPC_TASK_NOCONNECT : RPC_TASK_SOFTCONN; + rpc_call_async(clnt, &cb->cb_msg, RPC_TASK_SOFT | flags, cb->cb_ops ? &nfsd4_cb_ops : &nfsd4_cb_probe_ops, cb); } |