NFS: Avoid duplicate resets of attribute cache timeouts

We know that the attributes changed on the server if and only if the
change attribute is different. Otherwise, we're just refreshing our
cache with values that were already known to be stale.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

fs/nfs/inode.c

@@ -2055,13 +2055,13 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
 					| NFS_INO_INVALID_OTHER;
 				if (S_ISDIR(inode->i_mode))
 					nfs_force_lookup_revalidate(inode);
+				attr_changed = true;
 				dprintk("NFS: change_attr change on server for file %s/%ld\n",
 						inode->i_sb->s_id,
 						inode->i_ino);
 			} else if (!have_delegation)
 				nfsi->cache_validity |= NFS_INO_DATA_INVAL_DEFER;
 			inode_set_iversion_raw(inode, fattr->change_attr);
-			attr_changed = true;
 		}
 	} else {
 		nfsi->cache_validity |=
@@ -2094,7 +2094,6 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
 				i_size_write(inode, new_isize);
 				if (!have_writers)
 					invalid |= NFS_INO_INVALID_DATA;
-				attr_changed = true;
 			}
 			dprintk("NFS: isize change on server for file %s/%ld "
 					"(%Ld to %Ld)\n",
@@ -2126,7 +2125,6 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
 			inode->i_mode = newmode;
 			invalid |= NFS_INO_INVALID_ACCESS
 				| NFS_INO_INVALID_ACL;
-			attr_changed = true;
 		}
 	} else if (fattr_supported & NFS_ATTR_FATTR_MODE)
 		nfsi->cache_validity |=
@@ -2137,7 +2135,6 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
 			invalid |= NFS_INO_INVALID_ACCESS
 				| NFS_INO_INVALID_ACL;
 			inode->i_uid = fattr->uid;
-			attr_changed = true;
 		}
 	} else if (fattr_supported & NFS_ATTR_FATTR_OWNER)
 		nfsi->cache_validity |=
@@ -2148,7 +2145,6 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
 			invalid |= NFS_INO_INVALID_ACCESS
 				| NFS_INO_INVALID_ACL;
 			inode->i_gid = fattr->gid;
-			attr_changed = true;
 		}
 	} else if (fattr_supported & NFS_ATTR_FATTR_GROUP)
 		nfsi->cache_validity |=
@@ -2159,7 +2155,6 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
 			if (S_ISDIR(inode->i_mode))
 				invalid |= NFS_INO_INVALID_DATA;
 			set_nlink(inode, fattr->nlink);
-			attr_changed = true;
 		}
 	} else if (fattr_supported & NFS_ATTR_FATTR_NLINK)
 		nfsi->cache_validity |=