linux-kernel - [PATCH 4.14 62/69] NFSv4: Only pass the delegation to setattr if were sending a truncate

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Date:   Wed, 14 Aug 2019 19:02:00 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org,
        Trond Myklebust <trond.myklebust@...merspace.com>
Subject: [PATCH 4.14 62/69] NFSv4: Only pass the delegation to setattr if were sending a truncate

From: Trond Myklebust <trond.myklebust@...marydata.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@...merspace.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.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;