NFSv4.2: SETXATTR should update ctime

Otherwise, `stat` will report a stale value to users.

Signed-off-by: Anna Schumaker <[e-mail]>
Signed-off-by: Trond Myklebust <[e-mail]>

fs/nfs/nfs42proc.c

···
 				const void *buf, size_t buflen, int flags)
 {
 	struct nfs_server *server = NFS_SERVER(inode);
+	__u32 bitmask[NFS_BITMASK_SZ];
 	struct page *pages[NFS4XATTR_MAXPAGES];
 	struct nfs42_setxattrargs arg = {
 		.fh		= NFS_FH(inode),
+		.bitmask	= bitmask,
 		.xattr_pages	= pages,
 		.xattr_len	= buflen,
 		.xattr_name	= name,
 		.xattr_flags	= flags,
 	};
-	struct nfs42_setxattrres res;
+	struct nfs42_setxattrres res = {
+		.server		= server,
+	};
 	struct rpc_message msg = {
 		.rpc_proc	= &nfs4_procedures[NFSPROC4_CLNT_SETXATTR],
 		.rpc_argp	= &arg,
···
 	if (buflen > server->sxasize)
 		return -ERANGE;
 
+	res.fattr = nfs_alloc_fattr();
+	if (!res.fattr)
+		return -ENOMEM;
+
 	if (buflen > 0) {
 		np = nfs4_buf_to_pages_noslab(buf, buflen, arg.xattr_pages);
-		if (np < 0)
-			return np;
+		if (np < 0) {
+			ret = np;
+			goto out;
+		}
 	} else
 		np = 0;
+
+	nfs4_bitmask_set(bitmask, server->cache_consistency_bitmask,
+			 inode, NFS_INO_INVALID_CHANGE);
 
 	ret = nfs4_call_sync(server->client, server, &msg, &arg.seq_args,
 	    &res.seq_res, 1);
···
 	for (; np > 0; np--)
 		put_page(pages[np - 1]);
 
-	if (!ret)
+	if (!ret) {
 		nfs4_update_changeattr(inode, &res.cinfo, timestamp, 0);
+		ret = nfs_post_op_update_inode(inode, res.fattr);
+	}
 
+out:
+	kfree(res.fattr);
 	return ret;
 }
 

fs/nfs/nfs42xdr.c

···
 #define NFS4_enc_setxattr_sz		(compound_encode_hdr_maxsz + \
 					 encode_sequence_maxsz + \
 					 encode_putfh_maxsz + \
-					 encode_setxattr_maxsz)
+					 encode_setxattr_maxsz + \
+					 encode_getattr_maxsz)
 #define NFS4_dec_setxattr_sz		(compound_decode_hdr_maxsz + \
 					 decode_sequence_maxsz + \
 					 decode_putfh_maxsz + \
-					 decode_setxattr_maxsz)
+					 decode_setxattr_maxsz + \
+					 decode_getattr_maxsz)
 #define NFS4_enc_listxattrs_sz		(compound_encode_hdr_maxsz + \
 					 encode_sequence_maxsz + \
 					 encode_putfh_maxsz + \
···
 	encode_sequence(xdr, &args->seq_args, &hdr);
 	encode_putfh(xdr, args->fh, &hdr);
 	encode_setxattr(xdr, args, &hdr);
+	encode_getfattr(xdr, args->bitmask, &hdr);
 	encode_nops(&hdr);
 }
 
···
 	status = decode_putfh(xdr);
 	if (status)
 		goto out;
-
 	status = decode_setxattr(xdr, &res->cinfo);
+	if (status)
+		goto out;
+	status = decode_getfattr(xdr, res->fattr, res->server);
 out:
 	return status;
 }

include/linux/nfs_xdr.h

···
 struct nfs42_setxattrargs {
 	struct nfs4_sequence_args	seq_args;
 	struct nfs_fh			*fh;
+	const u32			*bitmask;
 	const char			*xattr_name;
 	u32				xattr_flags;
 	size_t				xattr_len;
···
 struct nfs42_setxattrres {
 	struct nfs4_sequence_res	seq_res;
 	struct nfs4_change_info		cinfo;
+	struct nfs_fattr		*fattr;
+	const struct nfs_server		*server;
 };
 
 struct nfs42_getxattrargs {