NFS add support for asynchronous COPY

Change xdr to always send COPY asynchronously.

Keep the list copies send in a list under a server structure.
Once copy is sent, it waits on a completion structure that will
be signalled by the callback thread that receives CB_OFFLOAD.

If CB_OFFLOAD returned an error and even if it returned partial
bytes, ignore them (as we can't commit without a verifier to
match) and return an error.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

1 files changed, 50 insertions, 5 deletions

diff --git a/fs/nfs/nfs42proc.c b/fs/nfs/nfs42proc.c
index 5f59b6f65a42..023aea8f6cf1 100644
--- a/fs/nfs/nfs42proc.c
+++ b/fs/nfs/nfs42proc.c
@@ -130,6 +130,37 @@ out_unlock:
 	return err;
 }
 
+static int handle_async_copy(struct nfs42_copy_res *res,
+			     struct nfs_server *server,
+			     struct file *src,
+			     struct file *dst,
+			     nfs4_stateid *src_stateid)
+{
+	struct nfs4_copy_state *copy;
+	int status = NFS4_OK;
+
+	copy = kzalloc(sizeof(struct nfs4_copy_state), GFP_NOFS);
+	if (!copy)
+		return -ENOMEM;
+	memcpy(&copy->stateid, &res->write_res.stateid, NFS4_STATEID_SIZE);
+	init_completion(&copy->completion);
+
+	spin_lock(&server->nfs_client->cl_lock);
+	list_add_tail(&copy->copies, &server->ss_copies);
+	spin_unlock(&server->nfs_client->cl_lock);
+
+	wait_for_completion_interruptible(&copy->completion);
+	spin_lock(&server->nfs_client->cl_lock);
+	list_del_init(&copy->copies);
+	spin_unlock(&server->nfs_client->cl_lock);
+	res->write_res.count = copy->count;
+	memcpy(&res->write_res.verifier, &copy->verf, sizeof(copy->verf));
+	status = -copy->error;
+
+	kfree(copy);
+	return status;
+}
+
 static ssize_t _nfs42_proc_copy(struct file *src,
 				struct nfs_lock_context *src_lock,
 				struct file *dst,
@@ -168,9 +199,13 @@ static ssize_t _nfs42_proc_copy(struct file *src,
 	if (status)
 		return status;
 
-	res->commit_res.verf = kzalloc(sizeof(struct nfs_writeverf), GFP_NOFS);
-	if (!res->commit_res.verf)
-		return -ENOMEM;
+	res->commit_res.verf = NULL;
+	if (args->sync) {
+		res->commit_res.verf =
+			kzalloc(sizeof(struct nfs_writeverf), GFP_NOFS);
+		if (!res->commit_res.verf)
+			return -ENOMEM;
+	}
 	status = nfs4_call_sync(server->client, server, &msg,
 				&args->seq_args, &res->seq_res, 0);
 	if (status == -ENOTSUPP)
@@ -178,18 +213,27 @@ static ssize_t _nfs42_proc_copy(struct file *src,
 	if (status)
 		goto out;
 
-	if (nfs_write_verifier_cmp(&res->write_res.verifier.verifier,
+	if (args->sync &&
+		nfs_write_verifier_cmp(&res->write_res.verifier.verifier,
 				    &res->commit_res.verf->verifier)) {
 		status = -EAGAIN;
 		goto out;
 	}
 
+	if (!res->synchronous) {
+		status = handle_async_copy(res, server, src, dst,
+				&args->src_stateid);
+		if (status)
+			return status;
+	}
+
 	truncate_pagecache_range(dst_inode, pos_dst,
 				 pos_dst + res->write_res.count);
 
 	status = res->write_res.count;
 out:
-	kfree(res->commit_res.verf);
+	if (args->sync)
+		kfree(res->commit_res.verf);
 	return status;
 }
 
@@ -206,6 +250,7 @@ ssize_t nfs42_proc_copy(struct file *src, loff_t pos_src,
 		.dst_fh		= NFS_FH(file_inode(dst)),
 		.dst_pos	= pos_dst,
 		.count		= count,
+		.sync		= false,
 	};
 	struct nfs42_copy_res res;
 	struct nfs4_exception src_exception = {