[PATCH 2/5] NFSv4.1: Pin the inode and super block in asynchronous layoutcommit

[Trond Myklebust <trond.myklebust@primarydata.com>]

If we're sending an asynchronous layoutcommit, then we need to ensure
that the inode and the super block remain pinned.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
---
 fs/nfs/internal.h       | 18 ++++++++++++++++++
 fs/nfs/nfs4proc.c       | 19 +++++++++++--------
 include/linux/nfs_xdr.h |  1 +
 3 files changed, 30 insertions(+), 8 deletions(-)

diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index a98cf2006179..d65f693c013b 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -514,6 +514,24 @@ extern int nfs41_walk_client_list(struct nfs_client *clp,
 				struct nfs_client **result,
 				struct rpc_cred *cred);
 
+static inline struct inode *nfs_igrab_and_active(struct inode *inode)
+{
+	if (igrab(inode) == NULL)
+		return NULL;
+	nfs_sb_active(inode->i_sb);
+	return inode;
+}
+
+static inline void nfs_iput_and_deactive(struct inode *inode)
+{
+	if (!inode) {
+		struct super_block *sb = inode->i_sb;
+
+		iput(inode);
+		nfs_sb_deactive(sb);
+	}
+}
+
 /*
  * Determine the device name as a string
  */
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index b803c1d363e7..770495bcd525 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -7994,6 +7994,7 @@ static void nfs4_layoutcommit_release(void *calldata)
 	nfs_post_op_update_inode_force_wcc(data->args.inode,
 					   data->res.fattr);
 	put_rpccred(data->cred);
+	nfs_iput_and_deactive(data->inode);
 	kfree(data);
 }
 
@@ -8018,7 +8019,6 @@ nfs4_proc_layoutcommit(struct nfs4_layoutcommit_data *data, bool sync)
 		.rpc_message = &msg,
 		.callback_ops = &nfs4_layoutcommit_ops,
 		.callback_data = data,
-		.flags = RPC_TASK_ASYNC,
 	};
 	struct rpc_task *task;
 	int status = 0;
@@ -8029,18 +8029,21 @@ nfs4_proc_layoutcommit(struct nfs4_layoutcommit_data *data, bool sync)
 		data->args.lastbytewritten,
 		data->args.inode->i_ino);
 
+	if (!sync) {
+		data->inode = nfs_igrab_and_active(data->args.inode);
+		if (data->inode == NULL) {
+			nfs4_layoutcommit_release(data);
+			return -EAGAIN;
+		}
+		task_setup_data.flags = RPC_TASK_ASYNC;
+	}
 	nfs4_init_sequence(&data->args.seq_args, &data->res.seq_res, 1);
 	task = rpc_run_task(&task_setup_data);
 	if (IS_ERR(task))
 		return PTR_ERR(task);
-	if (sync == false)
-		goto out;
-	status = nfs4_wait_for_completion_rpc_task(task);
-	if (status != 0)
-		goto out;
-	status = task->tk_status;
+	if (sync)
+		status = task->tk_status;
 	trace_nfs4_layoutcommit(data->args.inode, status);
-out:
 	dprintk("%s: status %d\n", __func__, status);
 	rpc_put_task(task);
 	return status;
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index 2c35e2affa6f..bb0d56f737e0 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -285,6 +285,7 @@ struct nfs4_layoutcommit_data {
 	struct nfs_fattr fattr;
 	struct list_head lseg_list;
 	struct rpc_cred *cred;
+	struct inode *inode;
 	struct nfs4_layoutcommit_args args;
 	struct nfs4_layoutcommit_res res;
 };
-- 
2.1.0