On Wed, 2021-06-09 at 10:31 -0400, Benjamin Coddington wrote: > > It's not disputed that mounts waiting on the transport layer will block > other mounts. > > It might be able to be changed: there's this torch: > https://lore.kernel.org/linux-nfs/87378omld4.fsf@xxxxxxxxxxxxxxxxxxxxxxxx/ > No. > ..or there may be another way we don't have to wait .. > OK. So let's look at how we can solve the problem of the initial connection to the server timing out and causing hangs in nfs41_walk_client_list(), and leave aside any other corner case problems (such as the server going down while we're mounting). How about something like the following (compile tested only) patch? 8<-------------------------------------------------------- >From 30833f78b5b4c7780c91f705b0867ef5492a9eed Mon Sep 17 00:00:00 2001 From: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx> Date: Wed, 9 Jun 2021 10:04:46 -0400 Subject: [PATCH] NFSv4: Initialise connection to the server in nfs4_alloc_client() Set up the connection to the NFSv4 server in nfs4_alloc_client(), before we've added the struct nfs_client to the net-namespace's nfs_client_list so that a downed server won't cause other mounts to hang in the trunking detection code. Reported-by: Michael Wakabayashi <mwakabayashi@xxxxxxxxxx> Fixes: 5c6e5b60aae4 ("NFS: Fix an Oops in the pNFS files and flexfiles connection setup to the DS") Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx> --- fs/nfs/nfs4client.c | 82 +++++++++++++++++++++++---------------------- 1 file changed, 42 insertions(+), 40 deletions(-) diff --git a/fs/nfs/nfs4client.c b/fs/nfs/nfs4client.c index 42719384e25f..28431acd1230 100644 --- a/fs/nfs/nfs4client.c +++ b/fs/nfs/nfs4client.c @@ -197,8 +197,11 @@ void nfs40_shutdown_client(struct nfs_client *clp) struct nfs_client *nfs4_alloc_client(const struct nfs_client_initdata *cl_init) { - int err; + char buf[INET6_ADDRSTRLEN + 1]; + const char *ip_addr = cl_init->ip_addr; struct nfs_client *clp = nfs_alloc_client(cl_init); + int err; + if (IS_ERR(clp)) return clp; @@ -222,6 +225,44 @@ struct nfs_client *nfs4_alloc_client(const struct nfs_client_initdata *cl_init) init_waitqueue_head(&clp->cl_lock_waitq); #endif INIT_LIST_HEAD(&clp->pending_cb_stateids); + + if (cl_init->minorversion != 0) + __set_bit(NFS_CS_INFINITE_SLOTS, &clp->cl_flags); + __set_bit(NFS_CS_DISCRTRY, &clp->cl_flags); + __set_bit(NFS_CS_NO_RETRANS_TIMEOUT, &clp->cl_flags); + + /* + * Set up the connection to the server before we add add to the + * global list. + */ + err = nfs_create_rpc_client(clp, cl_init, RPC_AUTH_GSS_KRB5I); + if (err == -EINVAL) + err = nfs_create_rpc_client(clp, cl_init, RPC_AUTH_UNIX); + if (err < 0) + goto error; + + /* If no clientaddr= option was specified, find a usable cb address */ + if (ip_addr == NULL) { + struct sockaddr_storage cb_addr; + struct sockaddr *sap = (struct sockaddr *)&cb_addr; + + err = rpc_localaddr(clp->cl_rpcclient, sap, sizeof(cb_addr)); + if (err < 0) + goto error; + err = rpc_ntop(sap, buf, sizeof(buf)); + if (err < 0) + goto error; + ip_addr = (const char *)buf; + } + strlcpy(clp->cl_ipaddr, ip_addr, sizeof(clp->cl_ipaddr)); + + err = nfs_idmap_new(clp); + if (err < 0) { + dprintk("%s: failed to create idmapper. Error = %d\n", + __func__, err); + goto error; + } + __set_bit(NFS_CS_IDMAP, &clp->cl_res_state); return clp; error: @@ -372,8 +413,6 @@ static int nfs4_init_client_minor_version(struct nfs_client *clp) struct nfs_client *nfs4_init_client(struct nfs_client *clp, const struct nfs_client_initdata *cl_init) { - char buf[INET6_ADDRSTRLEN + 1]; - const char *ip_addr = cl_init->ip_addr; struct nfs_client *old; int error; @@ -381,43 +420,6 @@ struct nfs_client *nfs4_init_client(struct nfs_client *clp, /* the client is initialised already */ return clp; - /* Check NFS protocol revision and initialize RPC op vector */ - clp->rpc_ops = &nfs_v4_clientops; - - if (clp->cl_minorversion != 0) - __set_bit(NFS_CS_INFINITE_SLOTS, &clp->cl_flags); - __set_bit(NFS_CS_DISCRTRY, &clp->cl_flags); - __set_bit(NFS_CS_NO_RETRANS_TIMEOUT, &clp->cl_flags); - - error = nfs_create_rpc_client(clp, cl_init, RPC_AUTH_GSS_KRB5I); - if (error == -EINVAL) - error = nfs_create_rpc_client(clp, cl_init, RPC_AUTH_UNIX); - if (error < 0) - goto error; - - /* If no clientaddr= option was specified, find a usable cb address */ - if (ip_addr == NULL) { - struct sockaddr_storage cb_addr; - struct sockaddr *sap = (struct sockaddr *)&cb_addr; - - error = rpc_localaddr(clp->cl_rpcclient, sap, sizeof(cb_addr)); - if (error < 0) - goto error; - error = rpc_ntop(sap, buf, sizeof(buf)); - if (error < 0) - goto error; - ip_addr = (const char *)buf; - } - strlcpy(clp->cl_ipaddr, ip_addr, sizeof(clp->cl_ipaddr)); - - error = nfs_idmap_new(clp); - if (error < 0) { - dprintk("%s: failed to create idmapper. Error = %d\n", - __func__, error); - goto error; - } - __set_bit(NFS_CS_IDMAP, &clp->cl_res_state); - error = nfs4_init_client_minor_version(clp); if (error < 0) goto error; -- 2.31.1 -- Trond Myklebust Linux NFS client maintainer, Hammerspace trond.myklebust@xxxxxxxxxxxxxxx
