Re: [PATCH v2] erofs-utils: dump: print filesystem blocksize

[Gao Xiang via Linux-erofs <linux-erofs@lists.ozlabs.org>]

Hi Sandeep,

On Mon, Apr 15, 2024 at 11:35:38AM -0700, Sandeep Dhavale wrote:
> mkfs.erofs supports creating filesystem images with different
> blocksizes. Add filesystem blocksize in super block dump so
> its easier to inspect the filesystem.
>
> The field is added after FS magic, so the output now looks like:
>
> Filesystem magic number:                      0xE0F5E1E2
> Filesystem blocksize:                         65536
> Filesystem blocks:                            21
> Filesystem inode metadata start block:        0
> Filesystem shared xattr metadata start block: 0
> Filesystem root nid:                          36
> Filesystem lz4_max_distance:                  65535
> Filesystem sb_extslots:                       0
> Filesystem inode count:                       10
> Filesystem created:                           Fri Apr 12 15:43:40 2024
> Filesystem features:                          sb_csum mtime 0padding
> Filesystem UUID:                              a84a2acc-08d8-4b72-8b8c-b811a815fa07
>
> Signed-off-by: Sandeep Dhavale <dhavale@google.com>
> ---
> Changes since v2:
> 	- Moved the field after FS magic as suggested by Gao
>  dump/main.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/dump/main.c b/dump/main.c
> index a89fc6b..928909d 100644
> --- a/dump/main.c
> +++ b/dump/main.c
> @@ -633,6 +633,8 @@ static void erofsdump_show_superblock(void)
>
>  	fprintf(stdout, "Filesystem magic number:                      0x%04X\n",
>  			EROFS_SUPER_MAGIC_V1);
> +	fprintf(stdout, "Filesystem blocksize:                         %llu\n",
> +			erofs_blksiz(&sbi) | 0ULL);

Could we use `%u` for `erofs_blksiz(&sbi)`? since currently EROFS
block size isn't possible to be larger than PAGE_SIZE.

Even if block size > page size is supported, I think we should
not consider too large blocksizes.

Otherwise it looks good to me.

Thanks,
Gao Xiang