Re: [RFC 4/8] shmem: add helpers to get block size

From: Matthew Wilcox
Date: Fri Apr 21 2023 - 18:50:03 EST


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;