From 5fe6eaa1f9a00b9a5927e3b791ecad2f3eaab130 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Thu, 15 Sep 2016 10:55:20 -0400 Subject: SUNRPC: Generalize the RPC buffer allocation API xprtrdma needs to allocate the Call and Reply buffers separately. TBH, the reliance on using a single buffer for the pair of XDR buffers is transport implementation-specific. Transports that want to allocate separate Call and Reply buffers will ignore the "size" argument anyway. Don't bother passing it. The buf_alloc method can't return two pointers. Instead, make the method's return value an error code, and set the rq_buffer pointer in the method itself. This gives call_allocate an opportunity to terminate an RPC instead of looping forever when a permanent problem occurs. If a request is just bogus, or the transport is in a state where it can't allocate resources for any request, there needs to be a way to kill the RPC right there and not loop. This immediately fixes a rare problem in the backchannel send path, which loops if the server happens to send a CB request whose call+reply size is larger than a page (which it shouldn't do yet). One more issue: looks like xprt_inject_disconnect was incorrectly placed in the failure path in call_allocate. It needs to be in the success path, as it is for other call-sites. Signed-off-by: Chuck Lever Signed-off-by: Anna Schumaker --- net/sunrpc/xprtsock.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) (limited to 'net/sunrpc/xprtsock.c') diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c index bf168838a029..bd30b4b18d72 100644 --- a/net/sunrpc/xprtsock.c +++ b/net/sunrpc/xprtsock.c @@ -2533,23 +2533,28 @@ static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq) * we allocate pages instead doing a kmalloc like rpc_malloc is because we want * to use the server side send routines. */ -static void *bc_malloc(struct rpc_task *task, size_t size) +static int bc_malloc(struct rpc_task *task) { + struct rpc_rqst *rqst = task->tk_rqstp; + size_t size = rqst->rq_callsize; struct page *page; struct rpc_buffer *buf; - WARN_ON_ONCE(size > PAGE_SIZE - sizeof(struct rpc_buffer)); - if (size > PAGE_SIZE - sizeof(struct rpc_buffer)) - return NULL; + if (size > PAGE_SIZE - sizeof(struct rpc_buffer)) { + WARN_ONCE(1, "xprtsock: large bc buffer request (size %zu)\n", + size); + return -EINVAL; + } page = alloc_page(GFP_KERNEL); if (!page) - return NULL; + return -ENOMEM; buf = page_address(page); buf->len = PAGE_SIZE; - return buf->data; + rqst->rq_buffer = buf->data; + return 0; } /* -- cgit v1.2.3