On Fri, Apr 21, 2023 at 02:43:56PM -0700, Luis Chamberlain wrote: > struct shmem_sb_info { > +#ifdef CONFIG_TMPFS > + u64 blocksize; > +#endif u64? You're planning on supporting a blocksize larger than 2GB? I would store block_order (in an unsigned char) and then you can avoid the call to ffs(), at the expense of doing 1UL << sbi->block_order;