NFSv4.2: query the extended attribute access bits

RFC 8276 defines separate ACCESS bits for extended attribute checking.
Query them in nfs_do_access and opendata.
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

fs/nfs/dir.c

@@ -2673,6 +2673,10 @@ static int nfs_do_access(struct inode *inode, const struct cred *cred, int mask)
 	 * Determine which access bits we want to ask for...
 	 */
 	cache.mask = NFS_ACCESS_READ | NFS_ACCESS_MODIFY | NFS_ACCESS_EXTEND;
+	if (nfs_server_capable(inode, NFS_CAP_XATTR)) {
+		cache.mask |= NFS_ACCESS_XAREAD | NFS_ACCESS_XAWRITE |
+		    NFS_ACCESS_XALIST;
+	}
 	if (S_ISDIR(inode->i_mode))
 		cache.mask |= NFS_ACCESS_DELETE | NFS_ACCESS_LOOKUP;
 	else

fs/nfs/nfs4proc.c

@@ -1341,6 +1341,12 @@ static struct nfs4_opendata *nfs4_opendata_alloc(struct dentry *dentry,
 				NFS4_ACCESS_MODIFY |
 				NFS4_ACCESS_EXTEND |
 				NFS4_ACCESS_EXECUTE;
+#ifdef CONFIG_NFS_V4_2
+			if (server->caps & NFS_CAP_XATTR)
+				p->o_arg.access |= NFS4_ACCESS_XAREAD |
+				    NFS4_ACCESS_XAWRITE |
+				    NFS4_ACCESS_XALIST;
+#endif
 		}
 	}
 	p->o_arg.clientid = server->nfs_client->cl_clientid;