SUNRPC: Clean up allocation and freeing of back channel requests

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

1 files changed, 55 insertions, 40 deletions

diff --git a/net/sunrpc/backchannel_rqst.c b/net/sunrpc/backchannel_rqst.c
index 28504dfd3dad..1baa41099469 100644
--- a/net/sunrpc/backchannel_rqst.c
+++ b/net/sunrpc/backchannel_rqst.c
@@ -67,6 +67,55 @@ static void xprt_free_allocation(struct rpc_rqst *req)
         kfree(req);
 }
 
+static int xprt_alloc_xdr_buf(struct xdr_buf *buf, gfp_t gfp_flags)
+{
+        struct page *page;
+        /* Preallocate one XDR receive buffer */
+        page = alloc_page(gfp_flags);
+        if (page == NULL)
+                return -ENOMEM;
+        buf->head[0].iov_base = page_address(page);
+        buf->head[0].iov_len = PAGE_SIZE;
+        buf->tail[0].iov_base = NULL;
+        buf->tail[0].iov_len = 0;
+        buf->page_len = 0;
+        buf->len = 0;
+        buf->buflen = PAGE_SIZE;
+        return 0;
+}
+
+static
+struct rpc_rqst *xprt_alloc_bc_req(struct rpc_xprt *xprt, gfp_t gfp_flags)
+{
+        struct rpc_rqst *req;
+
+        /* Pre-allocate one backchannel rpc_rqst */
+        req = kzalloc(sizeof(*req), gfp_flags);
+        if (req == NULL)
+                return NULL;
+
+        req->rq_xprt = xprt;
+        INIT_LIST_HEAD(&req->rq_list);
+        INIT_LIST_HEAD(&req->rq_bc_list);
+
+        /* Preallocate one XDR receive buffer */
+        if (xprt_alloc_xdr_buf(&req->rq_rcv_buf, gfp_flags) < 0) {
+                printk(KERN_ERR "Failed to create bc receive xbuf\n");
+                goto out_free;
+        }
+        req->rq_rcv_buf.len = PAGE_SIZE;
+
+        /* Preallocate one XDR send buffer */
+        if (xprt_alloc_xdr_buf(&req->rq_snd_buf, gfp_flags) < 0) {
+                printk(KERN_ERR "Failed to create bc snd xbuf\n");
+                goto out_free;
+        }
+        return req;
+out_free:
+        xprt_free_allocation(req);
+        return NULL;
+}
+
 /*
  * Preallocate up to min_reqs structures and related buffers for use
  * by the backchannel.  This function can be called multiple times
@@ -87,9 +136,7 @@ static void xprt_free_allocation(struct rpc_rqst *req)
  */
 int xprt_setup_backchannel(struct rpc_xprt *xprt, unsigned int min_reqs)
 {
-        struct page *page_rcv = NULL, *page_snd = NULL;
-        struct xdr_buf *xbufp = NULL;
-        struct rpc_rqst *req, *tmp;
+        struct rpc_rqst *req;
         struct list_head tmp_list;
         int i;
 
@@ -106,7 +153,7 @@ int xprt_setup_backchannel(struct rpc_xprt *xprt, unsigned int min_reqs)
         INIT_LIST_HEAD(&tmp_list);
         for (i = 0; i < min_reqs; i++) {
                 /* Pre-allocate one backchannel rpc_rqst */
-                req = kzalloc(sizeof(struct rpc_rqst), GFP_KERNEL);
+                req = xprt_alloc_bc_req(xprt, GFP_KERNEL);
                 if (req == NULL) {
                         printk(KERN_ERR "Failed to create bc rpc_rqst\n");
                         goto out_free;
@@ -115,41 +162,6 @@ int xprt_setup_backchannel(struct rpc_xprt *xprt, unsigned int min_reqs)
                 /* Add the allocated buffer to the tmp list */
                 dprintk("RPC:       adding req= %p\n", req);
                 list_add(&req->rq_bc_pa_list, &tmp_list);
-
-                req->rq_xprt = xprt;
-                INIT_LIST_HEAD(&req->rq_list);
-                INIT_LIST_HEAD(&req->rq_bc_list);
-
-                /* Preallocate one XDR receive buffer */
-                page_rcv = alloc_page(GFP_KERNEL);
-                if (page_rcv == NULL) {
-                        printk(KERN_ERR "Failed to create bc receive xbuf\n");
-                        goto out_free;
-                }
-                xbufp = &req->rq_rcv_buf;
-                xbufp->head[0].iov_base = page_address(page_rcv);
-                xbufp->head[0].iov_len = PAGE_SIZE;
-                xbufp->tail[0].iov_base = NULL;
-                xbufp->tail[0].iov_len = 0;
-                xbufp->page_len = 0;
-                xbufp->len = PAGE_SIZE;
-                xbufp->buflen = PAGE_SIZE;
-
-                /* Preallocate one XDR send buffer */
-                page_snd = alloc_page(GFP_KERNEL);
-                if (page_snd == NULL) {
-                        printk(KERN_ERR "Failed to create bc snd xbuf\n");
-                        goto out_free;
-                }
-
-                xbufp = &req->rq_snd_buf;
-                xbufp->head[0].iov_base = page_address(page_snd);
-                xbufp->head[0].iov_len = 0;
-                xbufp->tail[0].iov_base = NULL;
-                xbufp->tail[0].iov_len = 0;
-                xbufp->page_len = 0;
-                xbufp->len = 0;
-                xbufp->buflen = PAGE_SIZE;
         }
 
         /*
@@ -167,7 +179,10 @@ out_free:
         /*
          * Memory allocation failed, free the temporary list
          */
-        list_for_each_entry_safe(req, tmp, &tmp_list, rq_bc_pa_list) {
+        while (!list_empty(&tmp_list)) {
+                req = list_first_entry(&tmp_list,
+                                struct rpc_rqst,
+                                rq_bc_pa_list);
                 list_del(&req->rq_bc_pa_list);
                 xprt_free_allocation(req);
         }