SUNRPC/NFS: make rpc pipe upcall generic

The same function is used by idmap, gss and blocklayout code. Make it
generic.

Signed-off-by: Peng Tao <peng_tao@emc.com>
Signed-off-by: Jim Rees <rees@umich.edu>
Cc: stable@kernel.org [3.0]
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/blocklayout/blocklayout.c

@@ -964,7 +964,7 @@ static struct pnfs_layoutdriver_type blocklayout_type = {
 };
 
 static const struct rpc_pipe_ops bl_upcall_ops = {
-	.upcall		= bl_pipe_upcall,
+	.upcall		= rpc_pipe_generic_upcall,
 	.downcall	= bl_pipe_downcall,
 	.destroy_msg	= bl_pipe_destroy_msg,
 };

fs/nfs/blocklayout/blocklayout.h

@@ -169,8 +169,6 @@ extern wait_queue_head_t bl_wq;
 #define BL_DEVICE_REQUEST_ERR          0x2 /* User level process fails */
 
 /* blocklayoutdev.c */
-ssize_t bl_pipe_upcall(struct file *, struct rpc_pipe_msg *,
-		       char __user *, size_t);
 ssize_t bl_pipe_downcall(struct file *, const char __user *, size_t);
 void bl_pipe_destroy_msg(struct rpc_pipe_msg *);
 struct block_device *nfs4_blkdev_get(dev_t dev);

fs/nfs/blocklayout/blocklayoutdev.c

@@ -79,28 +79,6 @@ int nfs4_blkdev_put(struct block_device *bdev)
 	return blkdev_put(bdev, FMODE_READ);
 }
 
-/*
- * Shouldn't there be a rpc_generic_upcall() to do this for us?
- */
-ssize_t bl_pipe_upcall(struct file *filp, struct rpc_pipe_msg *msg,
-		       char __user *dst, size_t buflen)
-{
-	char *data = (char *)msg->data + msg->copied;
-	size_t mlen = min(msg->len - msg->copied, buflen);
-	unsigned long left;
-
-	left = copy_to_user(dst, data, mlen);
-	if (left == mlen) {
-		msg->errno = -EFAULT;
-		return -EFAULT;
-	}
-
-	mlen -= left;
-	msg->copied += mlen;
-	msg->errno = 0;
-	return mlen;
-}
-
 static struct bl_dev_msg bl_mount_reply;
 
 ssize_t bl_pipe_downcall(struct file *filp, const char __user *src,

fs/nfs/idmap.c

@@ -336,16 +336,14 @@ struct idmap {
 	struct idmap_hashtable	idmap_group_hash;
 };
 
-static ssize_t idmap_pipe_upcall(struct file *, struct rpc_pipe_msg *,
-				 char __user *, size_t);
 static ssize_t idmap_pipe_downcall(struct file *, const char __user *,
 				   size_t);
 static void idmap_pipe_destroy_msg(struct rpc_pipe_msg *);
 
 static unsigned int fnvhash32(const void *, size_t);
 
 static const struct rpc_pipe_ops idmap_upcall_ops = {
-	.upcall		= idmap_pipe_upcall,
+	.upcall		= rpc_pipe_generic_upcall,
 	.downcall	= idmap_pipe_downcall,
 	.destroy_msg	= idmap_pipe_destroy_msg,
 };
@@ -595,27 +593,6 @@ nfs_idmap_name(struct idmap *idmap, struct idmap_hashtable *h,
 	return ret;
 }
 
-/* RPC pipefs upcall/downcall routines */
-static ssize_t
-idmap_pipe_upcall(struct file *filp, struct rpc_pipe_msg *msg,
-		  char __user *dst, size_t buflen)
-{
-	char *data = (char *)msg->data + msg->copied;
-	size_t mlen = min(msg->len, buflen);
-	unsigned long left;
-
-	left = copy_to_user(dst, data, mlen);
-	if (left == mlen) {
-		msg->errno = -EFAULT;
-		return -EFAULT;
-	}
-
-	mlen -= left;
-	msg->copied += mlen;
-	msg->errno = 0;
-	return mlen;
-}
-
 static ssize_t
 idmap_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 {

include/linux/sunrpc/rpc_pipe_fs.h

@@ -44,6 +44,8 @@ RPC_I(struct inode *inode)
 	return container_of(inode, struct rpc_inode, vfs_inode);
 }
 
+extern ssize_t rpc_pipe_generic_upcall(struct file *, struct rpc_pipe_msg *,
+				       char __user *, size_t);
 extern int rpc_queue_upcall(struct inode *, struct rpc_pipe_msg *);
 
 struct rpc_clnt;

net/sunrpc/auth_gss/auth_gss.c

@@ -603,26 +603,6 @@ gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
 	return err;
 }
 
-static ssize_t
-gss_pipe_upcall(struct file *filp, struct rpc_pipe_msg *msg,
-		char __user *dst, size_t buflen)
-{
-	char *data = (char *)msg->data + msg->copied;
-	size_t mlen = min(msg->len, buflen);
-	unsigned long left;
-
-	left = copy_to_user(dst, data, mlen);
-	if (left == mlen) {
-		msg->errno = -EFAULT;
-		return -EFAULT;
-	}
-
-	mlen -= left;
-	msg->copied += mlen;
-	msg->errno = 0;
-	return mlen;
-}
-
 #define MSG_BUF_MAXSIZE 1024
 
 static ssize_t
@@ -1590,15 +1570,15 @@ static const struct rpc_credops gss_nullops = {
 };
 
 static const struct rpc_pipe_ops gss_upcall_ops_v0 = {
-	.upcall		= gss_pipe_upcall,
+	.upcall		= rpc_pipe_generic_upcall,
 	.downcall	= gss_pipe_downcall,
 	.destroy_msg	= gss_pipe_destroy_msg,
 	.open_pipe	= gss_pipe_open_v0,
 	.release_pipe	= gss_pipe_release,
 };
 
 static const struct rpc_pipe_ops gss_upcall_ops_v1 = {
-	.upcall		= gss_pipe_upcall,
+	.upcall		= rpc_pipe_generic_upcall,
 	.downcall	= gss_pipe_downcall,
 	.destroy_msg	= gss_pipe_destroy_msg,
 	.open_pipe	= gss_pipe_open_v1,

net/sunrpc/rpc_pipe.c

@@ -77,6 +77,26 @@ rpc_timeout_upcall_queue(struct work_struct *work)
 	rpc_purge_list(rpci, &free_list, destroy_msg, -ETIMEDOUT);
 }
 
+ssize_t rpc_pipe_generic_upcall(struct file *filp, struct rpc_pipe_msg *msg,
+				char __user *dst, size_t buflen)
+{
+	char *data = (char *)msg->data + msg->copied;
+	size_t mlen = min(msg->len - msg->copied, buflen);
+	unsigned long left;
+
+	left = copy_to_user(dst, data, mlen);
+	if (left == mlen) {
+		msg->errno = -EFAULT;
+		return -EFAULT;
+	}
+
+	mlen -= left;
+	msg->copied += mlen;
+	msg->errno = 0;
+	return mlen;
+}
+EXPORT_SYMBOL_GPL(rpc_pipe_generic_upcall);
+
 /**
  * rpc_queue_upcall - queue an upcall message to userspace
  * @inode: inode of upcall pipe on which to queue given message