This is a note to let you know that I've just added the patch titled rpc: share one xps between all backchannels to the 4.6-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: rpc-share-one-xps-between-all-backchannels.patch and it can be found in the queue-4.6 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 39a9beab5acb83176e8b9a4f0778749a09341f1f Mon Sep 17 00:00:00 2001 From: "J. Bruce Fields" <bfields@xxxxxxxxxx> Date: Tue, 17 May 2016 12:38:21 -0400 Subject: rpc: share one xps between all backchannels From: J. Bruce Fields <bfields@xxxxxxxxxx> commit 39a9beab5acb83176e8b9a4f0778749a09341f1f upstream. The spec allows backchannels for multiple clients to share the same tcp connection. When that happens, we need to use the same xprt for all of them. Similarly, we need the same xps. This fixes list corruption introduced by the multipath code. Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxx> Acked-by: Trond Myklebust <trondmy@xxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- include/linux/sunrpc/svc_xprt.h | 1 + include/linux/sunrpc/xprt.h | 1 + net/sunrpc/clnt.c | 18 ++++++++++++++---- net/sunrpc/svc_xprt.c | 2 ++ net/sunrpc/xprtsock.c | 1 + 5 files changed, 19 insertions(+), 4 deletions(-) --- a/include/linux/sunrpc/svc_xprt.h +++ b/include/linux/sunrpc/svc_xprt.h @@ -84,6 +84,7 @@ struct svc_xprt { struct net *xpt_net; struct rpc_xprt *xpt_bc_xprt; /* NFSv4.1 backchannel */ + struct rpc_xprt_switch *xpt_bc_xps; /* NFSv4.1 backchannel */ }; static inline void unregister_xpt_user(struct svc_xprt *xpt, struct svc_xpt_user *u) --- a/include/linux/sunrpc/xprt.h +++ b/include/linux/sunrpc/xprt.h @@ -296,6 +296,7 @@ struct xprt_create { size_t addrlen; const char *servername; struct svc_xprt *bc_xprt; /* NFSv4.1 backchannel */ + struct rpc_xprt_switch *bc_xps; unsigned int flags; }; --- a/net/sunrpc/clnt.c +++ b/net/sunrpc/clnt.c @@ -452,10 +452,20 @@ static struct rpc_clnt *rpc_create_xprt( struct rpc_clnt *clnt = NULL; struct rpc_xprt_switch *xps; - xps = xprt_switch_alloc(xprt, GFP_KERNEL); - if (xps == NULL) { - xprt_put(xprt); - return ERR_PTR(-ENOMEM); + if (args->bc_xprt && args->bc_xprt->xpt_bc_xps) { + WARN_ON(args->protocol != XPRT_TRANSPORT_BC_TCP); + xps = args->bc_xprt->xpt_bc_xps; + xprt_switch_get(xps); + } else { + xps = xprt_switch_alloc(xprt, GFP_KERNEL); + if (xps == NULL) { + xprt_put(xprt); + return ERR_PTR(-ENOMEM); + } + if (xprt->bc_xprt) { + xprt_switch_get(xps); + xprt->bc_xprt->xpt_bc_xps = xps; + } } clnt = rpc_new_client(args, xps, xprt, NULL); if (IS_ERR(clnt)) --- a/net/sunrpc/svc_xprt.c +++ b/net/sunrpc/svc_xprt.c @@ -136,6 +136,8 @@ static void svc_xprt_free(struct kref *k /* See comment on corresponding get in xs_setup_bc_tcp(): */ if (xprt->xpt_bc_xprt) xprt_put(xprt->xpt_bc_xprt); + if (xprt->xpt_bc_xps) + xprt_switch_put(xprt->xpt_bc_xps); xprt->xpt_ops->xpo_free(xprt); module_put(owner); } --- a/net/sunrpc/xprtsock.c +++ b/net/sunrpc/xprtsock.c @@ -3050,6 +3050,7 @@ static struct rpc_xprt *xs_setup_bc_tcp( return xprt; args->bc_xprt->xpt_bc_xprt = NULL; + args->bc_xprt->xpt_bc_xps = NULL; xprt_put(xprt); ret = ERR_PTR(-EINVAL); out_err: Patches currently in stable-queue which might be from bfields@xxxxxxxxxx are queue-4.6/nfsd-check-permissions-when-setting-acls.patch queue-4.6/nfsd-always-lock-state-exclusively.patch queue-4.6/rpc-share-one-xps-between-all-backchannels.patch queue-4.6/nfsd-extend-the-mutex-holding-region-around-in-nfsd4_process_open2.patch queue-4.6/nfsd4-rpc-move-backchannel-create-logic-into-rpc-code.patch queue-4.6/sunrpc-fix-xprt-leak-on-xps-allocation-failure.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html