Re: [PATCH v3 05/10] btrfs-progs: mkfs: align byte_count with sectorsize and zone size

[Qu Wenruo <quwenruo.btrfs@gmx.com>]

在 2024/5/22 15:32, Naohiro Aota 写道:
> While "byte_count" is eventually rounded down to sectorsize at make_btrfs()
> or btrfs_add_to_fs_id(), it would be better round it down first and do the
> size checks not to confuse the things.
>
> Also, on a zoned device, creating a btrfs whose size is not aligned to the
> zone boundary can be confusing. Round it down further to the zone boundary.
>
> The size calculation with a source directory is also tweaked to be aligned.
>
> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
> ---
>   mkfs/main.c | 11 +++++++++--
>   1 file changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/mkfs/main.c b/mkfs/main.c
> index a437ecc40c7f..baf889873b41 100644
> --- a/mkfs/main.c
> +++ b/mkfs/main.c
> @@ -1591,6 +1591,12 @@ int BOX_MAIN(mkfs)(int argc, char **argv)
>   	min_dev_size = btrfs_min_dev_size(nodesize, mixed,
>   					  opt_zoned ? zone_size(file) : 0,
>   					  metadata_profile, data_profile);
> +	if (byte_count) {
> +		byte_count = round_down(byte_count, sectorsize);
> +		if (opt_zoned)
> +			byte_count = round_down(byte_count,  zone_size(file));
> +	}
> +
>   	/*
>   	 * Enlarge the destination file or create a new one, using the size
>   	 * calculated from source dir.
> @@ -1624,12 +1630,13 @@ int BOX_MAIN(mkfs)(int argc, char **argv)
>   		 * Or we will always use source_dir_size calculated for mkfs.
>   		 */
>   		if (!byte_count)
> -			byte_count = device_get_partition_size_fd_stat(fd, &statbuf);
> +			byte_count = round_up(device_get_partition_size_fd_stat(fd, &statbuf),
> +					      sectorsize);
>   		source_dir_size = btrfs_mkfs_size_dir(source_dir, sectorsize,
>   				min_dev_size, metadata_profile, data_profile);
>   		if (byte_count < source_dir_size) {
>   			if (S_ISREG(statbuf.st_mode)) {
> -				byte_count = source_dir_size;
> +				byte_count = round_up(source_dir_size, sectorsize);

I believe we should round up not round down, if we're using --rootdir
option.

As smaller size would only be more possible to hit ENOSPC.

Otherwise looks good to me.

Thanks,
Qu
>   			} else {
>   				warning(
>   "the target device %llu (%s) is smaller than the calculated source directory size %llu (%s), mkfs may fail",