Merge tag 'nfs-for-4.9-1' of git://git.linux-nfs.org/projects/anna/linux-nfs

[cascardo/linux.git] / net / sunrpc / sched.c

diff --git a/net/sunrpc/sched.c b/net/sunrpc/sched.c
index 9ae5885..5db68b3 100644 (file)
--- a/net/sunrpc/sched.c
+++ b/net/sunrpc/sched.c
@@ -849,14 +849,17 @@ static void rpc_async_schedule(struct work_struct *work)
 }
 
 /**
- * rpc_malloc - allocate an RPC buffer
- * @task: RPC task that will use this buffer
- * @size: requested byte size
+ * rpc_malloc - allocate RPC buffer resources
+ * @task: RPC task
+ *
+ * A single memory region is allocated, which is split between the
+ * RPC call and RPC reply that this task is being used for. When
+ * this RPC is retired, the memory is released by calling rpc_free.
  *
  * To prevent rpciod from hanging, this allocator never sleeps,
- * returning NULL and suppressing warning if the request cannot be serviced
- * immediately.
- * The caller can arrange to sleep in a way that is safe for rpciod.
+ * returning -ENOMEM and suppressing warning if the request cannot
+ * be serviced immediately. The caller can arrange to sleep in a
+ * way that is safe for rpciod.
  *
  * Most requests are 'small' (under 2KiB) and can be serviced from a
  * mempool, ensuring that NFS reads and writes can always proceed,
@@ -865,8 +868,10 @@ static void rpc_async_schedule(struct work_struct *work)
  * In order to avoid memory starvation triggering more writebacks of
  * NFS requests, we avoid using GFP_KERNEL.
  */
-void *rpc_malloc(struct rpc_task *task, size_t size)
+int rpc_malloc(struct rpc_task *task)
 {
+       struct rpc_rqst *rqst = task->tk_rqstp;
+       size_t size = rqst->rq_callsize + rqst->rq_rcvsize;
        struct rpc_buffer *buf;
        gfp_t gfp = GFP_NOIO | __GFP_NOWARN;
 
@@ -880,28 +885,28 @@ void *rpc_malloc(struct rpc_task *task, size_t size)
                buf = kmalloc(size, gfp);
 
        if (!buf)
-               return NULL;
+               return -ENOMEM;
 
        buf->len = size;
        dprintk("RPC: %5u allocated buffer of size %zu at %p\n",
                        task->tk_pid, size, buf);
-       return &buf->data;
+       rqst->rq_buffer = buf->data;
+       rqst->rq_rbuffer = (char *)rqst->rq_buffer + rqst->rq_callsize;
+       return 0;
 }
 EXPORT_SYMBOL_GPL(rpc_malloc);
 
 /**
- * rpc_free - free buffer allocated via rpc_malloc
- * @buffer: buffer to free
+ * rpc_free - free RPC buffer resources allocated via rpc_malloc
+ * @task: RPC task
  *
  */
-void rpc_free(void *buffer)
+void rpc_free(struct rpc_task *task)
 {
+       void *buffer = task->tk_rqstp->rq_buffer;
        size_t size;
        struct rpc_buffer *buf;
 
-       if (!buffer)
-               return;
-
        buf = container_of(buffer, struct rpc_buffer, data);
        size = buf->len;