NFS: nfs_async_write_reschedule_io must not recurse into the writeback code

It is not safe to call filemap_fdatawrite_range() from
nfs_async_write_reschedule_io(), since we're often calling from a page
reclaim context. Just let fsync() redrive the writeback for us.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

fs/nfs/write.c

@@ -1444,8 +1444,6 @@ static void nfs_async_write_error(struct list_head *head, int error)
 static void nfs_async_write_reschedule_io(struct nfs_pgio_header *hdr)
 {
 	nfs_async_write_error(&hdr->pages, 0);
-	filemap_fdatawrite_range(hdr->inode->i_mapping, hdr->args.offset,
-			hdr->args.offset + hdr->args.count - 1);
 }
 
 static const struct nfs_pgio_completion_ops nfs_async_write_completion_ops = {