Re: [PATCH] proc: introduce proc_statfs()

From: Chao Yu
Date: Wed Jan 11 2023 - 04:21:15 EST


On 2023/1/11 1:58, Alexey Dobriyan wrote:
On Tue, Jan 10, 2023 at 11:20:03PM +0800, Chao Yu wrote:
Introduce proc_statfs() to replace simple_statfs(), so that
f_bsize queried from statfs() can be consistent w/ the value we
set in s_blocksize.

stat -f /proc/

Before:
ID: 0 Namelen: 255 Type: proc
Block size: 4096 Fundamental block size: 4096
Blocks: Total: 0 Free: 0 Available: 0
Inodes: Total: 0 Free: 0

After:
ID: 0 Namelen: 255 Type: proc
Block size: 1024 Fundamental block size: 1024
Blocks: Total: 0 Free: 0 Available: 0
Inodes: Total: 0 Free: 0

4096 is better value is in fact.

seq_files allocate 1 page and fill it, therefore reading less than
PAGE_SIZE from /proc is mostly waste of syscalls.

Ah, thanks for correcting me, so, how about updating .s_blocksize and
.s_blocksize_bits to PAGE_SIZE and PAGE_SHIFT?


I doubt anything uses f_bsize.

BTW this patch is not self contained.

Oh, yes, my bad.

Thanks,