From: Trond Myklebust <trond.myklebust@primarydata.com>
Date: Wed, 8 Jun 2016 01:44:08 +0000 (-0400)
Subject: NFS: Don't flush caches for a getattr that races with writeback
X-Git-Tag: v4.8-rc1~87^2~6^2~30
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=38512aa98a3feb6acd7da8f0ed5dade5b592b426;p=karo-tx-linux.git

NFS: Don't flush caches for a getattr that races with writeback

If there were outstanding writes then chalk up the unexpected change
attribute on the server to them.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
---

diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 52e7d6869e3b..60051e62d3f1 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -1729,12 +1729,15 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
 		if (inode->i_version != fattr->change_attr) {
 			dprintk("NFS: change_attr change on server for file %s/%ld\n",
 					inode->i_sb->s_id, inode->i_ino);
-			invalid |= NFS_INO_INVALID_ATTR
-				| NFS_INO_INVALID_DATA
-				| NFS_INO_INVALID_ACCESS
-				| NFS_INO_INVALID_ACL;
-			if (S_ISDIR(inode->i_mode))
-				nfs_force_lookup_revalidate(inode);
+			/* Could it be a race with writeback? */
+			if (nfsi->nrequests == 0) {
+				invalid |= NFS_INO_INVALID_ATTR
+					| NFS_INO_INVALID_DATA
+					| NFS_INO_INVALID_ACCESS
+					| NFS_INO_INVALID_ACL;
+				if (S_ISDIR(inode->i_mode))
+					nfs_force_lookup_revalidate(inode);
+			}
 			inode->i_version = fattr->change_attr;
 		}
 	} else {