forked from luck/tmp_suning_uos_patched
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 <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
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@ -239,7 +239,7 @@ struct rpc_task *rpc_wake_up_first(struct rpc_wait_queue *,
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void *);
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void rpc_wake_up_status(struct rpc_wait_queue *, int);
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void rpc_delay(struct rpc_task *, unsigned long);
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void * rpc_malloc(struct rpc_task *, size_t);
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int rpc_malloc(struct rpc_task *);
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void rpc_free(void *);
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int rpciod_up(void);
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void rpciod_down(void);
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@ -127,7 +127,7 @@ struct rpc_xprt_ops {
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void (*rpcbind)(struct rpc_task *task);
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void (*set_port)(struct rpc_xprt *xprt, unsigned short port);
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void (*connect)(struct rpc_xprt *xprt, struct rpc_task *task);
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void * (*buf_alloc)(struct rpc_task *task, size_t size);
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int (*buf_alloc)(struct rpc_task *task);
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void (*buf_free)(void *buffer);
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int (*send_request)(struct rpc_task *task);
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void (*set_retrans_timeout)(struct rpc_task *task);
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@ -1691,6 +1691,7 @@ call_allocate(struct rpc_task *task)
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struct rpc_rqst *req = task->tk_rqstp;
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struct rpc_xprt *xprt = req->rq_xprt;
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struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
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int status;
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dprint_status(task);
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@ -1716,11 +1717,14 @@ call_allocate(struct rpc_task *task)
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req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
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req->rq_rcvsize <<= 2;
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req->rq_buffer = xprt->ops->buf_alloc(task,
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req->rq_callsize + req->rq_rcvsize);
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if (req->rq_buffer != NULL)
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return;
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status = xprt->ops->buf_alloc(task);
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xprt_inject_disconnect(xprt);
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if (status == 0)
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return;
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if (status != -ENOMEM) {
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rpc_exit(task, status);
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return;
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}
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dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
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@ -849,14 +849,17 @@ static void rpc_async_schedule(struct work_struct *work)
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}
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/**
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* rpc_malloc - allocate an RPC buffer
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* @task: RPC task that will use this buffer
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* @size: requested byte size
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* rpc_malloc - allocate RPC buffer resources
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* @task: RPC task
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*
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* A single memory region is allocated, which is split between the
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* RPC call and RPC reply that this task is being used for. When
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* this RPC is retired, the memory is released by calling rpc_free.
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*
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* To prevent rpciod from hanging, this allocator never sleeps,
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* returning NULL and suppressing warning if the request cannot be serviced
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* immediately.
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* The caller can arrange to sleep in a way that is safe for rpciod.
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* returning -ENOMEM and suppressing warning if the request cannot
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* be serviced immediately. The caller can arrange to sleep in a
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* way that is safe for rpciod.
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*
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* Most requests are 'small' (under 2KiB) and can be serviced from a
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* mempool, ensuring that NFS reads and writes can always proceed,
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@ -865,8 +868,10 @@ static void rpc_async_schedule(struct work_struct *work)
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* In order to avoid memory starvation triggering more writebacks of
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* NFS requests, we avoid using GFP_KERNEL.
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*/
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void *rpc_malloc(struct rpc_task *task, size_t size)
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int rpc_malloc(struct rpc_task *task)
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{
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struct rpc_rqst *rqst = task->tk_rqstp;
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size_t size = rqst->rq_callsize + rqst->rq_rcvsize;
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struct rpc_buffer *buf;
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gfp_t gfp = GFP_NOIO | __GFP_NOWARN;
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@ -880,12 +885,13 @@ void *rpc_malloc(struct rpc_task *task, size_t size)
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buf = kmalloc(size, gfp);
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if (!buf)
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return NULL;
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return -ENOMEM;
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buf->len = size;
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dprintk("RPC: %5u allocated buffer of size %zu at %p\n",
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task->tk_pid, size, buf);
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return &buf->data;
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rqst->rq_buffer = buf->data;
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return 0;
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}
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EXPORT_SYMBOL_GPL(rpc_malloc);
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@ -159,29 +159,30 @@ static int svc_rdma_bc_sendto(struct svcxprt_rdma *rdma,
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/* Server-side transport endpoint wants a whole page for its send
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* buffer. The client RPC code constructs the RPC header in this
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* buffer before it invokes ->send_request.
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*
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* Returns NULL if there was a temporary allocation failure.
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*/
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static void *
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xprt_rdma_bc_allocate(struct rpc_task *task, size_t size)
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static int
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xprt_rdma_bc_allocate(struct rpc_task *task)
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{
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struct rpc_rqst *rqst = task->tk_rqstp;
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struct svc_xprt *sxprt = rqst->rq_xprt->bc_xprt;
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size_t size = rqst->rq_callsize;
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struct svcxprt_rdma *rdma;
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struct page *page;
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rdma = container_of(sxprt, struct svcxprt_rdma, sc_xprt);
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/* Prevent an infinite loop: try to make this case work */
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if (size > PAGE_SIZE)
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if (size > PAGE_SIZE) {
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WARN_ONCE(1, "svcrdma: large bc buffer request (size %zu)\n",
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size);
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return -EINVAL;
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}
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page = alloc_page(RPCRDMA_DEF_GFP);
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if (!page)
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return NULL;
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return -ENOMEM;
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return page_address(page);
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rqst->rq_buffer = page_address(page);
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return 0;
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}
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static void
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@ -477,7 +477,15 @@ xprt_rdma_connect(struct rpc_xprt *xprt, struct rpc_task *task)
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}
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}
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/*
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/**
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* xprt_rdma_allocate - allocate transport resources for an RPC
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* @task: RPC task
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*
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* Return values:
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* 0: Success; rq_buffer points to RPC buffer to use
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* ENOMEM: Out of memory, call again later
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* EIO: A permanent error occurred, do not retry
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*
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* The RDMA allocate/free functions need the task structure as a place
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* to hide the struct rpcrdma_req, which is necessary for the actual send/recv
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* sequence.
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@ -486,11 +494,12 @@ xprt_rdma_connect(struct rpc_xprt *xprt, struct rpc_task *task)
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* (rq_send_buf and rq_rcv_buf are both part of a single contiguous buffer).
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* We may register rq_rcv_buf when using reply chunks.
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*/
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static void *
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xprt_rdma_allocate(struct rpc_task *task, size_t size)
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static int
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xprt_rdma_allocate(struct rpc_task *task)
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{
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struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
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struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
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struct rpc_rqst *rqst = task->tk_rqstp;
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size_t size = rqst->rq_callsize + rqst->rq_rcvsize;
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struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(rqst->rq_xprt);
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struct rpcrdma_regbuf *rb;
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struct rpcrdma_req *req;
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size_t min_size;
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@ -498,7 +507,7 @@ xprt_rdma_allocate(struct rpc_task *task, size_t size)
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req = rpcrdma_buffer_get(&r_xprt->rx_buf);
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if (req == NULL)
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return NULL;
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return -ENOMEM;
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flags = RPCRDMA_DEF_GFP;
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if (RPC_IS_SWAPPER(task))
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dprintk("RPC: %s: size %zd, request 0x%p\n", __func__, size, req);
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req->rl_connect_cookie = 0; /* our reserved value */
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req->rl_task = task;
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return req->rl_sendbuf->rg_base;
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rqst->rq_buffer = req->rl_sendbuf->rg_base;
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return 0;
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out_rdmabuf:
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min_size = r_xprt->rx_data.inline_wsize;
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out_fail:
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rpcrdma_buffer_put(req);
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return NULL;
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return -ENOMEM;
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}
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/*
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@ -2533,23 +2533,28 @@ static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
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* we allocate pages instead doing a kmalloc like rpc_malloc is because we want
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* to use the server side send routines.
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*/
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static void *bc_malloc(struct rpc_task *task, size_t size)
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static int bc_malloc(struct rpc_task *task)
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{
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struct rpc_rqst *rqst = task->tk_rqstp;
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size_t size = rqst->rq_callsize;
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struct page *page;
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struct rpc_buffer *buf;
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WARN_ON_ONCE(size > PAGE_SIZE - sizeof(struct rpc_buffer));
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if (size > PAGE_SIZE - sizeof(struct rpc_buffer))
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return NULL;
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if (size > PAGE_SIZE - sizeof(struct rpc_buffer)) {
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WARN_ONCE(1, "xprtsock: large bc buffer request (size %zu)\n",
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size);
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return -EINVAL;
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}
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page = alloc_page(GFP_KERNEL);
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if (!page)
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return NULL;
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return -ENOMEM;
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buf = page_address(page);
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buf->len = PAGE_SIZE;
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return buf->data;
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rqst->rq_buffer = buf->data;
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return 0;
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}
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/*
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