[PATCH 1/5] NFSv4: Ensure we reference the inode for return-on-close in delegreturn

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

If we have to do a return-on-close in the delegreturn code, then
we must ensure that the inode and super block remain referenced.

Cc: Peng Tao <tao.peng@primarydata.com>
Cc: stable@vger.kernel.org # 3.17.x
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
---
 fs/nfs/nfs4proc.c | 19 ++++++++++++++-----
 1 file changed, 14 insertions(+), 5 deletions(-)

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index cd4295d84d54..b803c1d363e7 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -5175,9 +5175,16 @@ static void nfs4_delegreturn_done(struct rpc_task *task, void *calldata)
 static void nfs4_delegreturn_release(void *calldata)
 {
 	struct nfs4_delegreturndata *data = calldata;
+	struct inode *inode = data->inode;
+
+	if (inode) {
+		struct super_block *sb = inode->i_sb;
 
-	if (data->roc)
-		pnfs_roc_release(data->inode);
+		if (data->roc)
+			pnfs_roc_release(inode);
+		iput(inode);
+		nfs_sb_deactive(sb);
+	}
 	kfree(calldata);
 }
 
@@ -5234,9 +5241,11 @@ static int _nfs4_proc_delegreturn(struct inode *inode, struct rpc_cred *cred, co
 	nfs_fattr_init(data->res.fattr);
 	data->timestamp = jiffies;
 	data->rpc_status = 0;
-	data->inode = inode;
-	data->roc = list_empty(&NFS_I(inode)->open_files) ?
-		    pnfs_roc(inode) : false;
+	data->inode = igrab(inode);
+	if (data->inode) {
+		nfs_sb_active(inode->i_sb);
+		data->roc = nfs4_roc(inode);
+	}
 
 	task_setup_data.callback_data = data;
 	msg.rpc_argp = &data->args;
-- 
2.1.0