Re: [PATCH v2 17/19] md: raid1: check if adding pages to resync bio fails

[Johannes Thumshirn <jth@kernel.org>]

On 31/03/2023 20:13, Song Liu wrote:
> On Thu, Mar 30, 2023 at 3:44 AM Johannes Thumshirn
> <johannes.thumshirn@wdc.com> wrote:
>>
>> Check if adding pages to resync bio fails and if bail out.
>>
>> As the comment above suggests this cannot happen, WARN if it actually
>> happens.
>>
>> This way we can mark bio_add_pages as __must_check.
>>
>> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
>> Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
>> ---
>>   drivers/md/raid1-10.c |  7 ++++++-
>>   drivers/md/raid10.c   | 12 ++++++++++--
>>   2 files changed, 16 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/md/raid1-10.c b/drivers/md/raid1-10.c
>> index e61f6cad4e08..c21b6c168751 100644
>> --- a/drivers/md/raid1-10.c
>> +++ b/drivers/md/raid1-10.c
>> @@ -105,7 +105,12 @@ static void md_bio_reset_resync_pages(struct bio *bio, struct resync_pages *rp,
>>                   * won't fail because the vec table is big
>>                   * enough to hold all these pages
>>                   */
> 
> We know these won't fail. Shall we just use __bio_add_page?

We could yes, but I kind of like the assert() style warning.
But of cause ultimately your call.

Byte,
	Johannes