RE: Re: [PATCH v5 05/10] scsi: ufshpb: Region inactivation in host mode

[Daejun Park]

>>>>>> >> ---
>>>>>> >>  drivers/scsi/ufs/ufshpb.c | 14 ++++++++++++++
>>>>>> >>  drivers/scsi/ufs/ufshpb.h |  1 +
>>>>>> >>  2 files changed, 15 insertions(+)
>>>>>> >>
>>>>>> >> diff --git a/drivers/scsi/ufs/ufshpb.c b/drivers/scsi/ufs/ufshpb.c
>>>>>> >> index 6f4fd22eaf2f..0744feb4d484 100644
>>>>>> >> --- a/drivers/scsi/ufs/ufshpb.c
>>>>>> >> +++ b/drivers/scsi/ufs/ufshpb.c
>>>>>> >> @@ -907,6 +907,7 @@ static int ufshpb_execute_umap_req(struct
>>>>>> >> ufshpb_lu *hpb,
>>>>>> >>
>>>>>> >>      blk_execute_rq_nowait(q, NULL, req, 1, ufshpb_umap_req_compl_fn);
>>>>>> >>
>>>>>> >> +    hpb->stats.umap_req_cnt++;
>>>>>> >>      return 0;
>>>>>> >>  }
>>>>>> >>
>>>>>> >> @@ -1103,6 +1104,12 @@ static int ufshpb_issue_umap_req(struct
>>>>>> >> ufshpb_lu *hpb,
>>>>>> >>      return -EAGAIN;
>>>>>> >>  }
>>>>>> >>
>>>>>> >> +static int ufshpb_issue_umap_single_req(struct ufshpb_lu *hpb,
>>>>>> >> +                                    struct ufshpb_region *rgn)
>>>>>> >> +{
>>>>>> >> +    return ufshpb_issue_umap_req(hpb, rgn);
>>>>>> >> +}
>>>>>> >> +
>>>>>> >>  static int ufshpb_issue_umap_all_req(struct ufshpb_lu *hpb)
>>>>>> >>  {
>>>>>> >>      return ufshpb_issue_umap_req(hpb, NULL);
>>>>>> >> @@ -1115,6 +1122,10 @@ static void __ufshpb_evict_region(struct
>>>>>> >> ufshpb_lu *hpb,
>>>>>> >>      struct ufshpb_subregion *srgn;
>>>>>> >>      int srgn_idx;
>>>>>> >>
>>>>>> >> +
>>>>>> >> +    if (hpb->is_hcm && ufshpb_issue_umap_single_req(hpb, rgn))
>>>>>> >
>>>>>> > __ufshpb_evict_region() is called with rgn_state_lock held and IRQ
>>>>>> > disabled,
>>>>>> > when ufshpb_issue_umap_single_req() invokes blk_execute_rq_nowait(),
>>>>>> > below
>>>>>> > warning shall pop up every time, fix it?
>>>>>> >
>>>>>> > void blk_execute_rq_nowait(struct request_queue *q, struct gendisk
>>>>>> > *bd_disk,
>>>>>> >                  struct request *rq, int at_head,
>>>>>> >                          rq_end_io_fn *done)
>>>>>> > {
>>>>>> >       WARN_ON(irqs_disabled());
>>>>>> > ...
>>>>>> >
>>>>>> 
>>>>>> Moreover, since we are here with rgn_state_lock held and IRQ
>>>>>> disabled,
>>>>>> in ufshpb_get_req(), rq = kmem_cache_alloc(hpb->map_req_cache,
>>>>>> GFP_KERNEL)
>>>>>> has the GFP_KERNEL flag, scheduling while atomic???
>>>>> I think your comment applies to  ufshpb_issue_umap_all_req as well,
>>>>> Which is called from slave_configure/scsi_add_lun.
>>>>> 
>>>>> Since the host-mode series is utilizing the framework laid by the
>>>>> device-mode,
>>>>> Maybe you can add this comment to  Daejun's last version?
>>>> 
>>>> Hi Avri, Can Guo
>>>> 
>>>> I think ufshpb_issue_umap_single_req() can be moved to end of
>>>> ufshpb_evict_region().
>>>> Then we can avoid rgn_state_lock when it sends unmap command.
>>> 
>>> I am not the expert here, please you two fix it. I am just reporting
>>> what can be wrong. Anyways, ufshpb_issue_umap_single_req() should not
>>> be called with rgn_state_lock held - think about below (another 
>>> deadly)
>>> scenario.
>>> 
>>> lock(rgn_state_lock)
>>>   ufshpb_issue_umap_single_req()
>>>     ufshpb_prep()
>>>        lock(rgn_state_lock)   <---------- recursive spin_lock
>>> 
>>> BTW, @Daejun shouldn't we stop passthrough cmds from stepping
>>> into ufshpb_prep()? In current code, you are trying to use below
>>> check to block cmds other than write/discard/read, but a passthrough
>>> cmd can not be blocked by the check.
>>> 
>>>          if (!ufshpb_is_write_or_discard_cmd(cmd) &&
>>>              !ufshpb_is_read_cmd(cmd) )
>>>                  return 0;
>> 
>> I found this problem too. I fixed it and submit next patch.
> 
>You mean in V30, which has not been uploaded yet, right?

Yes, it is about v30.

Thanks,
Daejun

>Thanks,
>Can Guo.
> 
>> 
>> if (blk_rq_is_scsi(cmd->request) ||
>>             (!ufshpb_is_write_or_discard_cmd(cmd) &&
>>             !ufshpb_is_read_cmd(cmd)))
>>                 return 0;
>> 
>> 
>> Thanks,
>> Daejun
>> 
>>> Thanks,
>>> Can Guo.
>>> 
>>>> 
>>>> Thanks,
>>>> Daejun
>>>> 
>>>> 
>>>>> Thanks,
>>>>> Avri
>>>>> 
>>>>>> 
>>>>>> Can Guo.
>>>>>> 
>>>>>> > Thanks.
>>>>>> > Can Guo.
>>>>>> >
>>>>>> >> +            return;
>>>>>> >> +
>>>>>> >>      lru_info = &hpb->lru_info;
>>>>>> >>
>>>>>> >>      dev_dbg(&hpb->sdev_ufs_lu->sdev_dev, "evict region %d\n",
>>>>>> >> rgn->rgn_idx);
>>>>>> >> @@ -1855,6 +1866,7 @@ ufshpb_sysfs_attr_show_func(rb_noti_cnt);
>>>>>> >>  ufshpb_sysfs_attr_show_func(rb_active_cnt);
>>>>>> >>  ufshpb_sysfs_attr_show_func(rb_inactive_cnt);
>>>>>> >>  ufshpb_sysfs_attr_show_func(map_req_cnt);
>>>>>> >> +ufshpb_sysfs_attr_show_func(umap_req_cnt);
>>>>>> >>
>>>>>> >>  static struct attribute *hpb_dev_stat_attrs[] = {
>>>>>> >>      &dev_attr_hit_cnt.attr,
>>>>>> >> @@ -1863,6 +1875,7 @@ static struct attribute *hpb_dev_stat_attrs[] =
>>>>>> >> {
>>>>>> >>      &dev_attr_rb_active_cnt.attr,
>>>>>> >>      &dev_attr_rb_inactive_cnt.attr,
>>>>>> >>      &dev_attr_map_req_cnt.attr,
>>>>>> >> +    &dev_attr_umap_req_cnt.attr,
>>>>>> >>      NULL,
>>>>>> >>  };
>>>>>> >>
>>>>>> >> @@ -1978,6 +1991,7 @@ static void ufshpb_stat_init(struct ufshpb_lu
>>>>>> >> *hpb)
>>>>>> >>      hpb->stats.rb_active_cnt = 0;
>>>>>> >>      hpb->stats.rb_inactive_cnt = 0;
>>>>>> >>      hpb->stats.map_req_cnt = 0;
>>>>>> >> +    hpb->stats.umap_req_cnt = 0;
>>>>>> >>  }
>>>>>> >>
>>>>>> >>  static void ufshpb_param_init(struct ufshpb_lu *hpb)
>>>>>> >> diff --git a/drivers/scsi/ufs/ufshpb.h b/drivers/scsi/ufs/ufshpb.h
>>>>>> >> index bd4308010466..84598a317897 100644
>>>>>> >> --- a/drivers/scsi/ufs/ufshpb.h
>>>>>> >> +++ b/drivers/scsi/ufs/ufshpb.h
>>>>>> >> @@ -186,6 +186,7 @@ struct ufshpb_stats {
>>>>>> >>      u64 rb_inactive_cnt;
>>>>>> >>      u64 map_req_cnt;
>>>>>> >>      u64 pre_req_cnt;
>>>>>> >> +    u64 umap_req_cnt;
>>>>>> >>  };
>>>>>> >>
>>>>>> >>  struct ufshpb_lu {
>>>>> 
>>>>> 
>>>>> 
>>> 
>>> 
>>> 
> 
> 
>