2023-06-21 08:53:45

by Pankaj Raghav

Subject: [RFC 4/4] nvme: enable logical block size > PAGE_SIZE

Don't set the capacity to zero for when logical block size > PAGE_SIZE
as the block device with iomap aops support allocating block cache with
a minimum folio order.

Signed-off-by: Pankaj Raghav <[email protected]>
---
drivers/nvme/host/core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 98bfb3d9c22a..36cf610f938c 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -1886,7 +1886,7 @@ static void nvme_update_disk_info(struct gendisk *disk,
* The block layer can't support LBA sizes larger than the page size
* yet, so catch this early and don't allow block I/O.
*/
- if (ns->lba_shift > PAGE_SHIFT) {
+ if ((ns->lba_shift > PAGE_SHIFT) && IS_ENABLED(CONFIG_BUFFER_HEAD)) {
capacity = 0;
bs = (1 << 9);
}
--
2.39.2

2023-06-21 09:24:52

by Hannes Reinecke

Subject: Re: [RFC 4/4] nvme: enable logical block size > PAGE_SIZE

On 6/21/23 10:38, Pankaj Raghav wrote:
> Don't set the capacity to zero for when logical block size > PAGE_SIZE
> as the block device with iomap aops support allocating block cache with
> a minimum folio order.
>
> Signed-off-by: Pankaj Raghav <[email protected]>
> ---
> drivers/nvme/host/core.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
> index 98bfb3d9c22a..36cf610f938c 100644
> --- a/drivers/nvme/host/core.c
> +++ b/drivers/nvme/host/core.c
> @@ -1886,7 +1886,7 @@ static void nvme_update_disk_info(struct gendisk *disk,
> * The block layer can't support LBA sizes larger than the page size
> * yet, so catch this early and don't allow block I/O.
> */
> - if (ns->lba_shift > PAGE_SHIFT) {
> + if ((ns->lba_shift > PAGE_SHIFT) && IS_ENABLED(CONFIG_BUFFER_HEAD)) {
> capacity = 0;
> bs = (1 << 9);
> }
Again, I can't see why this would be contingent on CONFIG_BUFFER_HEAD.
I'll be rebasing my patchset on your mapping_set_orders() patches and
repost.

Cheers,

Hannes

2023-06-21 11:05:57

by Pankaj Raghav

Subject: Re: [RFC 4/4] nvme: enable logical block size > PAGE_SIZE

On 2023-06-21 11:07, Hannes Reinecke wrote:
> On 6/21/23 10:38, Pankaj Raghav wrote:
>> Don't set the capacity to zero for when logical block size > PAGE_SIZE
>> as the block device with iomap aops support allocating block cache with
>> a minimum folio order.
>>
>> Signed-off-by: Pankaj Raghav <[email protected]>
>> ---
>>   drivers/nvme/host/core.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
>> index 98bfb3d9c22a..36cf610f938c 100644
>> --- a/drivers/nvme/host/core.c
>> +++ b/drivers/nvme/host/core.c
>> @@ -1886,7 +1886,7 @@ static void nvme_update_disk_info(struct gendisk *disk,
>>        * The block layer can't support LBA sizes larger than the page size
>>        * yet, so catch this early and don't allow block I/O.
>>        */
>> -    if (ns->lba_shift > PAGE_SHIFT) {
>> +    if ((ns->lba_shift > PAGE_SHIFT) && IS_ENABLED(CONFIG_BUFFER_HEAD)) {
>>           capacity = 0;
>>           bs = (1 << 9);
>>       }
> Again, I can't see why this would be contingent on CONFIG_BUFFER_HEAD.
> I'll be rebasing my patchset on your mapping_set_orders() patches and repost.
>

As I explained in the previous email, I get a BUG from buffer.c when I don't make it conditional.
The hope is when we move to iomap based aops for the block cache, we can just get rid of
`if (ns->lba_shift > PAGE_SHIFT)` block and no dependence on CONFIG_BUFFER_HEAD.

> Cheers,
>
> Hannes
>