Re: [PATCH 05/10] block: null: use blk_is_valid_logical_block_size

Damien Le Moal
2020-07-21T11:15:58Z

On 2020/07/21 19:54, Maxim Levitsky wrote:
> This slightly changes the behavier of the driver,

s/behavier/behavior

> when given invalid block size (non power of two, or below 512 bytes),
> but shoudn't matter.
>
> Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
> ---
> drivers/block/null_blk_main.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/block/null_blk_main.c b/drivers/block/null_blk_main.c
> index 87b31f9ca362e..e4df4b903b90b 100644
> --- a/drivers/block/null_blk_main.c
> +++ b/drivers/block/null_blk_main.c
> @@ -1684,8 +1684,8 @@ static int null_init_tag_set(struct nullb *nullb, struct blk_mq_tag_set *set)
>
> static int null_validate_conf(struct nullb_device *dev)
> {
> - dev->blocksize = round_down(dev->blocksize, 512);
> - dev->blocksize = clamp_t(unsigned int, dev->blocksize, 512, 4096);
> + if (!blk_is_valid_logical_block_size(dev->blocksize))
> + return -ENODEV;
>
> if (dev->queue_mode == NULL_Q_MQ && dev->use_per_node_hctx) {
> if (dev->submit_queues != nr_online_nodes)
> @@ -1865,7 +1865,7 @@ static int __init null_init(void)
> struct nullb *nullb;
> struct nullb_device *dev;
>
> - if (g_bs > PAGE_SIZE) {
> + if (!blk_is_valid_logical_block_size(g_bs)) {
> pr_warn("invalid block size\n");
> pr_warn("defaults block size to %lu\n", PAGE_SIZE);
> g_bs = PAGE_SIZE;

Not sure if this change is OK. Shouldn't the if here be kept as is and
blk_is_valid_logical_block_size() called after it to check values lower than 4K ?

--
Damien Le Moal
Western Digital Research