nfs: add support for large folios

NFS already is void of folio size assumption, so just pass the chunk size
to __filemap_get_folio and set the large folio address_space flag for all
regular files.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

fs/nfs/file.c

@@ -339,6 +339,7 @@ static int nfs_write_begin(struct file *file, struct address_space *mapping,
 			   loff_t pos, unsigned len, struct page **pagep,
 			   void **fsdata)
 {
+	fgf_t fgp = FGP_WRITEBEGIN;
 	struct folio *folio;
 	int once_thru = 0;
 	int ret;
@@ -346,8 +347,9 @@ static int nfs_write_begin(struct file *file, struct address_space *mapping,
 	dfprintk(PAGECACHE, "NFS: write_begin(%pD2(%lu), %u@%lld)\n",
 		file, mapping->host->i_ino, len, (long long) pos);
 
+	fgp |= fgf_set_order(len);
 start:
-	folio = __filemap_get_folio(mapping, pos >> PAGE_SHIFT, FGP_WRITEBEGIN,
+	folio = __filemap_get_folio(mapping, pos >> PAGE_SHIFT, fgp,
 				    mapping_gfp_mask(mapping));
 	if (IS_ERR(folio))
 		return PTR_ERR(folio);

fs/nfs/inode.c

@@ -491,6 +491,7 @@ nfs_fhget(struct super_block *sb, struct nfs_fh *fh, struct nfs_fattr *fattr)
 			inode->i_fop = NFS_SB(sb)->nfs_client->rpc_ops->file_ops;
 			inode->i_data.a_ops = &nfs_file_aops;
 			nfs_inode_init_regular(nfsi);
+			mapping_set_large_folios(inode->i_mapping);
 		} else if (S_ISDIR(inode->i_mode)) {
 			inode->i_op = NFS_SB(sb)->nfs_client->rpc_ops->dir_inode_ops;
 			inode->i_fop = &nfs_dir_operations;