nfs: clean up rest of reqs when failing to add one

If we fail to set up things before sending anything over wire,
we need to clean up the reqs that are still attached to the
IO descriptor.
Signed-off-by: NPeng Tao <tao.peng@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

fs/nfs/pagelist.c

@@ -1126,6 +1126,7 @@ static int nfs_do_recoalesce(struct nfs_pageio_descriptor *desc)
 static int nfs_pageio_add_request_mirror(struct nfs_pageio_descriptor *desc,
 		struct nfs_page *req)
 {
+	struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
 	int ret;
 
 	do {
@@ -1153,7 +1154,7 @@ int nfs_pageio_add_request(struct nfs_pageio_descriptor *desc,
 
 	nfs_pageio_setup_mirroring(desc, req);
 	if (desc->pg_error < 0)
-		return 0;
+		goto out_failed;
 
 	for (midx = 0; midx < desc->pg_mirror_count; midx++) {
 		if (midx) {
@@ -1170,7 +1171,8 @@ int nfs_pageio_add_request(struct nfs_pageio_descriptor *desc,
 
 			if (IS_ERR(dupreq)) {
 				nfs_page_group_unlock(req);
-				return 0;
+				desc->pg_error = PTR_ERR(dupreq);
+				goto out_failed;
 			}
 
 			nfs_lock_request(dupreq);
@@ -1183,10 +1185,19 @@ int nfs_pageio_add_request(struct nfs_pageio_descriptor *desc,
 		if (nfs_pgio_has_mirroring(desc))
 			desc->pg_mirror_idx = midx;
 		if (!nfs_pageio_add_request_mirror(desc, dupreq))
-			return 0;
+			goto out_failed;
 	}
 
 	return 1;
+
+out_failed:
+	/*
+	 * We might have failed before sending any reqs over wire.
+	 * clean up rest of the reqs in mirror pg_list
+	 */
+	if (desc->pg_error)
+		desc->pg_completion_ops->error_cleanup(&mirror->pg_list);
+	return 0;
 }
 
 /*