Re: [PATCH] f2fs-tools: fix the sector_size to default value

[Chao Yu]

On 2018/5/4 17:20, Yunlong Song wrote:
> f2fs-tools uses ioctl BLKSSZGET to get sector_size, however, this ioctl
> will return a value which may be larger than 512 (according to the value
> of q->limits.logical_block_size), then this will be inconsistent with
> the start_sector, since start_sector is got from ioctl HDIO_GETGEO and
> is always in 512 size unit for a sector. To fix this problem, just set
> the sector_size to the default value 512.

Please check below discussion:

https://sourceforge.net/p/linux-f2fs/mailman/message/36282479/

Anyway, we will not set sector_size to 512 by default for backward
compatibility, since some users may calculated total_sector_number by
theirselves via BLKSSZGET.

Usage: mkfs.f2fs [options] device [sectors]:
sectors: number of sectors. [default: determined by device size]

So how about changing as below?

	zone_align_start_offset =
		(c.start_sector * DEFAULT_SECTOR_SIZE +
		2 * F2FS_BLKSIZE + zone_size_bytes - 1) /
		zone_size_bytes * zone_size_bytes -
		c.start_sector * DEFAULT_SECTOR_SIZE;

Thanks,

> 
> Signed-off-by: Yunlong Song <yunlong.song@xxxxxxxxxx>
> ---
>  lib/libf2fs.c | 7 -------
>  1 file changed, 7 deletions(-)
> 
> diff --git a/lib/libf2fs.c b/lib/libf2fs.c
> index 102e579..e160f2a 100644
> --- a/lib/libf2fs.c
> +++ b/lib/libf2fs.c
> @@ -768,7 +768,6 @@ void get_kernel_uname_version(__u8 *version)
>  int get_device_info(int i)
>  {
>  	int32_t fd = 0;
> -	uint32_t sector_size;
>  #ifndef BLKGETSIZE64
>  	uint32_t total_sectors;
>  #endif
> @@ -822,12 +821,6 @@ int get_device_info(int i)
>  	} else if (S_ISREG(stat_buf->st_mode)) {
>  		dev->total_sectors = stat_buf->st_size / dev->sector_size;
>  	} else if (S_ISBLK(stat_buf->st_mode)) {
> -#ifdef BLKSSZGET
> -		if (ioctl(fd, BLKSSZGET, &sector_size) < 0)
> -			MSG(0, "\tError: Using the default sector size\n");
> -		else if (dev->sector_size < sector_size)
> -			dev->sector_size = sector_size;
> -#endif
>  #ifdef BLKGETSIZE64
>  		if (ioctl(fd, BLKGETSIZE64, &dev->total_sectors) < 0) {
>  			MSG(0, "\tError: Cannot get the device size\n");
>