NFSv4/pnfs: Ensure pNFS allocation modes are consistent with nfsiod

Ensure that pNFS allocations that can be called from rpciod/nfsiod
callback can fail in low memory mode, so that the threads don't block
and loop forever.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

fs/nfs/nfs42proc.c

@@ -1017,7 +1017,7 @@ int nfs42_proc_layouterror(struct pnfs_layout_segment *lseg,
 		return -EOPNOTSUPP;
 	if (n > NFS42_LAYOUTERROR_MAX)
 		return -EINVAL;
-	data = nfs42_alloc_layouterror_data(lseg, GFP_KERNEL);
+	data = nfs42_alloc_layouterror_data(lseg, nfs_io_gfp_mask());
 	if (!data)
 		return -ENOMEM;
 	for (i = 0; i < n; i++) {

fs/nfs/pnfs.c

@@ -1233,7 +1233,7 @@ pnfs_send_layoutreturn(struct pnfs_layout_hdr *lo,
 	int status = 0;
 
 	*pcred = NULL;
-	lrp = kzalloc(sizeof(*lrp), GFP_KERNEL);
+	lrp = kzalloc(sizeof(*lrp), nfs_io_gfp_mask());
 	if (unlikely(lrp == NULL)) {
 		status = -ENOMEM;
 		spin_lock(&ino->i_lock);
@@ -2206,7 +2206,7 @@ _pnfs_grab_empty_layout(struct inode *ino, struct nfs_open_context *ctx)
 	struct pnfs_layout_hdr *lo;
 
 	spin_lock(&ino->i_lock);
-	lo = pnfs_find_alloc_layout(ino, ctx, GFP_KERNEL);
+	lo = pnfs_find_alloc_layout(ino, ctx, nfs_io_gfp_mask());
 	if (!lo)
 		goto out_unlock;
 	if (!test_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags))
@@ -2249,8 +2249,8 @@ static void _lgopen_prepare_attached(struct nfs4_opendata *data,
 	lo = _pnfs_grab_empty_layout(ino, ctx);
 	if (!lo)
 		return;
-	lgp = pnfs_alloc_init_layoutget_args(ino, ctx, &current_stateid,
-					     &rng, GFP_KERNEL);
+	lgp = pnfs_alloc_init_layoutget_args(ino, ctx, &current_stateid, &rng,
+					     nfs_io_gfp_mask());
 	if (!lgp) {
 		pnfs_clear_first_layoutget(lo);
 		nfs_layoutget_end(lo);
@@ -2275,8 +2275,8 @@ static void _lgopen_prepare_floating(struct nfs4_opendata *data,
 	};
 	struct nfs4_layoutget *lgp;
 
-	lgp = pnfs_alloc_init_layoutget_args(ino, ctx, &current_stateid,
-					     &rng, GFP_KERNEL);
+	lgp = pnfs_alloc_init_layoutget_args(ino, ctx, &current_stateid, &rng,
+					     nfs_io_gfp_mask());
 	if (!lgp)
 		return;
 	data->lgp = lgp;
@@ -2691,13 +2691,11 @@ pnfs_generic_pg_init_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *r
 		else
 			rd_size = nfs_dreq_bytes_left(pgio->pg_dreq);
 
-		pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
-						   nfs_req_openctx(req),
-						   req_offset(req),
-						   rd_size,
-						   IOMODE_READ,
-						   false,
-						   GFP_KERNEL);
+		pgio->pg_lseg =
+			pnfs_update_layout(pgio->pg_inode, nfs_req_openctx(req),
+					   req_offset(req), rd_size,
+					   IOMODE_READ, false,
+					   nfs_io_gfp_mask());
 		if (IS_ERR(pgio->pg_lseg)) {
 			pgio->pg_error = PTR_ERR(pgio->pg_lseg);
 			pgio->pg_lseg = NULL;
@@ -2718,13 +2716,10 @@ pnfs_generic_pg_init_write(struct nfs_pageio_descriptor *pgio,
 	pnfs_generic_pg_check_layout(pgio);
 	pnfs_generic_pg_check_range(pgio, req);
 	if (pgio->pg_lseg == NULL) {
-		pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
-						   nfs_req_openctx(req),
-						   req_offset(req),
-						   wb_size,
-						   IOMODE_RW,
-						   false,
-						   GFP_KERNEL);
+		pgio->pg_lseg =
+			pnfs_update_layout(pgio->pg_inode, nfs_req_openctx(req),
+					   req_offset(req), wb_size, IOMODE_RW,
+					   false, nfs_io_gfp_mask());
 		if (IS_ERR(pgio->pg_lseg)) {
 			pgio->pg_error = PTR_ERR(pgio->pg_lseg);
 			pgio->pg_lseg = NULL;
@@ -3183,7 +3178,7 @@ pnfs_layoutcommit_inode(struct inode *inode, bool sync)
 
 	status = -ENOMEM;
 	/* Note kzalloc ensures data->res.seq_res.sr_slot == NULL */
-	data = kzalloc(sizeof(*data), GFP_NOFS);
+	data = kzalloc(sizeof(*data), nfs_io_gfp_mask());
 	if (!data)
 		goto clear_layoutcommitting;
 
@@ -3250,7 +3245,7 @@ struct nfs4_threshold *pnfs_mdsthreshold_alloc(void)
 {
 	struct nfs4_threshold *thp;
 
-	thp = kzalloc(sizeof(*thp), GFP_KERNEL);
+	thp = kzalloc(sizeof(*thp), nfs_io_gfp_mask());
 	if (!thp) {
 		dprintk("%s mdsthreshold allocation failed\n", __func__);
 		return NULL;