linux-kernel - [PATCH 2.6.32 18/42] nfs: if we have no valid attrs, then dont declare the attribute cache valid

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Message-Id: <20160123141222.761147351@1wt.eu>
Date:	Sat, 23 Jan 2016 15:12:39 +0100
From:	Willy Tarreau <w@....eu>
To:	linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:	Steve French <steve.french@...marydata.com>,
	Jeff Layton <jeff.layton@...marydata.com>,
	Trond Myklebust <trond.myklebust@...marydata.com>,
	Ben Hutchings <ben@...adent.org.uk>, Willy Tarreau <w@....eu>
Subject: [PATCH 2.6.32 18/42] nfs: if we have no valid attrs, then dont declare the
 attribute cache valid

2.6.32-longterm review patch.  If anyone has any objections, please let me know.

------------------

From: Jeff Layton <jlayton@...chiereds.net>

commit c812012f9ca7cf89c9e1a1cd512e6c3b5be04b85 upstream.

If we pass in an empty nfs_fattr struct to nfs_update_inode, it will
(correctly) not update any of the attributes, but it then clears the
NFS_INO_INVALID_ATTR flag, which indicates that the attributes are
up to date. Don't clear the flag if the fattr struct has no valid
attrs to apply.

Reviewed-by: Steve French <steve.french@...marydata.com>
Signed-off-by: Jeff Layton <jeff.layton@...marydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@...marydata.com>
Signed-off-by: Ben Hutchings <ben@...adent.org.uk>
(cherry picked from commit ddab0155aa9589600861e3f65d505982b719496a)
Signed-off-by: Willy Tarreau <w@....eu>
---
 fs/nfs/inode.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index bfaef7b..9129a32 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -1333,7 +1333,11 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
 			nfsi->attrtimeo_timestamp = now;
 		}
 	}
-	invalid &= ~NFS_INO_INVALID_ATTR;
+
+	/* Don't declare attrcache up to date if there were no attrs! */
+	if (fattr->valid != 0)
+		invalid &= ~NFS_INO_INVALID_ATTR;
+
 	/* Don't invalidate the data if we were to blame */
 	if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)
 				|| S_ISLNK(inode->i_mode)))
-- 
1.7.12.2.21.g234cd45.dirty