Re: [PATCH blktests] src/miniublk: fix logical block size setting

[Ming Lei <ming.lei@redhat.com>]

On Sat, Nov 04, 2023 at 09:17:42PM +0900, Akinobu Mita wrote:
> The miniublk always sets the logical block size to 512 bytes when setting
> a regular file-backed loop target.
> A test fails if the regular file is on a filesystem built on a block
> device with a logical block size of 4KB.
> 
> $ cd blktests
> $ modprobe -r scsi_debug
> $ modprobe scsi_debug sector_size=4096 dev_size_mb=2048
> $ mkfs.ext4 /dev/sdX
> $ mount /dev/sdX results/
> $ ./check ublk/003
> 
> The logical block size of the ublk block device is set to 512 bytes,
> so a request that is not 4KB aligned may occur, and the miniublk will
> attempt to process it with direct IO and fail.
> 
> The original ublk program already fixed this problem by determining
> the logical block size to set based on the block device to which the
> target regular file belongs.
> 
> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
> ---
>  src/miniublk.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/src/miniublk.c b/src/miniublk.c
> index 1c97668..565aa60 100644
> --- a/src/miniublk.c
> +++ b/src/miniublk.c
> @@ -1440,6 +1440,8 @@ static int ublk_loop_tgt_init(struct ublk_dev *dev)
>  		p.basic.physical_bs_shift = ilog2(pbs);
>  	} else if (S_ISREG(st.st_mode)) {
>  		bytes = st.st_size;
> +		p.basic.logical_bs_shift = ilog2(st.st_blksize);
> +		p.basic.physical_bs_shift = ilog2(st.st_blksize);
>  	} else {
>  		bytes = 0;
>  	}
> @@ -1512,6 +1514,8 @@ static int ublk_loop_tgt_recover(struct ublk_dev *dev)
>  			return -1;
>  	} else if (S_ISREG(st.st_mode)) {
>  		bytes = st.st_size;
> +		bs = st.st_blksize;
> +		pbs = st.st_blksize;
>  	} else {
>  		bytes = 0;

Looks fine,

Reviewed-by: Ming Lei <ming.lei@redhat.com>

Thanks,
Ming