On 2020/5/25 09:26, Damien Le Moal wrote:
> On 2020/05/22 21:19, Coly Li wrote:
>> Currently we don't support writeback mode for zoned device as backing
>> device. So reject it by sysfs interface.
>>
>> This rejection will be removed after the writeback cache mode support
>> for zoned device gets done.
>>
>> Signed-off-by: Coly Li <colyli@xxxxxxx>
>> Cc: Damien Le Moal <damien.lemoal@xxxxxxx>
>> Cc: Hannes Reinecke <hare@xxxxxxxx>
>> Cc: Johannes Thumshirn <johannes.thumshirn@xxxxxxx>
>> ---
>> drivers/md/bcache/sysfs.c | 5 +++++
>> 1 file changed, 5 insertions(+)
>>
>> diff --git a/drivers/md/bcache/sysfs.c b/drivers/md/bcache/sysfs.c
>> index 323276994aab..41bdbc42a17d 100644
>> --- a/drivers/md/bcache/sysfs.c
>> +++ b/drivers/md/bcache/sysfs.c
>> @@ -359,6 +359,11 @@ STORE(__cached_dev)
>> if (v < 0)
>> return v;
>>
>> + if ((unsigned int) v == CACHE_MODE_WRITEBACK) {
>> + pr_err("writeback mode is not supported for zoned backing device.\n");
>> + return -ENOTSUPP;
>> + }
>> +
>> if ((unsigned int) v != BDEV_CACHE_MODE(&dc->sb)) {
>> SET_BDEV_CACHE_MODE(&dc->sb, v);
>> bch_write_bdev_super(dc, NULL);
>>
>
> Do you have a similar check in bcache user tools at format time ? Or is the
> cache mode specified only when the bcache device is started ?
Yes I do the cache mode check in bcache-tools, and if user sets
writeback mode, bcache-tools will inform user and switch it to
writethrough mode explicitly.
>
> Looks good.
>
> Reviewed-by: Damien Le Moal <damien.lemoal@xxxxxxx>
>
Thank you for the review!
Coly Li
