releases/4.14.139/nfsv4-only-pass-the-delegation-to-setattr-if-we-re-sending-a-truncate.patch

From 991eedb1371dc09b0f9848f59c8898fe63d198c0 Mon Sep 17 00:00:00 2001
From: Trond Myklebust <trond.myklebust@primarydata.com>
Date: Mon, 9 Apr 2018 11:15:30 -0400
Subject: NFSv4: Only pass the delegation to setattr if we're sending a truncate

From: Trond Myklebust <trond.myklebust@primarydata.com>

commit 991eedb1371dc09b0f9848f59c8898fe63d198c0 upstream.

Even then it isn't really necessary. The reason why we may not want to
pass in a stateid in other cases is that we cannot use the delegation
credential.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 fs/nfs/nfs4proc.c |   12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -2954,7 +2954,6 @@ static int _nfs4_do_setattr(struct inode
 	};
 	struct rpc_cred *delegation_cred = NULL;
 	unsigned long timestamp = jiffies;
-	fmode_t fmode;
 	bool truncate;
 	int status;
 
@@ -2962,11 +2961,12 @@ static int _nfs4_do_setattr(struct inode
 
 	/* Servers should only apply open mode checks for file size changes */
 	truncate = (arg->iap->ia_valid & ATTR_SIZE) ? true : false;
-	fmode = truncate ? FMODE_WRITE : FMODE_READ;
+	if (!truncate)
+		goto zero_stateid;
 
-	if (nfs4_copy_delegation_stateid(inode, fmode, &arg->stateid, &delegation_cred)) {
+	if (nfs4_copy_delegation_stateid(inode, FMODE_WRITE, &arg->stateid, &delegation_cred)) {
 		/* Use that stateid */
-	} else if (truncate && ctx != NULL) {
+	} else if (ctx != NULL) {
 		struct nfs_lock_context *l_ctx;
 		if (!nfs4_valid_open_stateid(ctx->state))
 			return -EBADF;
@@ -2978,8 +2978,10 @@ static int _nfs4_do_setattr(struct inode
 		nfs_put_lock_context(l_ctx);
 		if (status == -EIO)
 			return -EBADF;
-	} else
+	} else {
+zero_stateid:
 		nfs4_stateid_copy(&arg->stateid, &zero_stateid);
+	}
 	if (delegation_cred)
 		msg.rpc_cred = delegation_cred;