2022-09-20 10:39:31

by John Garry

Subject: [PATCH RFC 3/6] scsi: core: Add scsi_get_dev()

Add a function which allows use to alloc a sdev with configurable
device parent, and channel:id:lun.

This is useful for separating adding a scsi device into separate alloc
and scan steps.

Signed-off-by: John Garry <[email protected]>
---
drivers/scsi/scsi_scan.c | 25 +++++++++++++++++++++++++
include/scsi/scsi_host.h | 3 +++
2 files changed, 28 insertions(+)

diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index 3759b1a77504..fd15ddac01b6 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -1988,3 +1988,28 @@ void scsi_forget_host(struct Scsi_Host *shost)
spin_unlock_irqrestore(shost->host_lock, flags);
}

+struct scsi_device *scsi_get_dev(struct device *parent, int channel, uint id, u64 lun)
+{
+ struct Scsi_Host *shost = dev_to_shost(parent);
+ struct scsi_device *sdev = NULL;
+ struct scsi_target *starget;
+
+ mutex_lock(&shost->scan_mutex);
+ if (!scsi_host_scan_allowed(shost))
+ goto out;
+
+ starget = scsi_alloc_target(parent, 0, id);
+ if (!starget)
+ goto out;
+
+ sdev = scsi_alloc_sdev(starget, 0, NULL);
+ if (sdev)
+ sdev->borken = 0;
+ else
+ scsi_target_reap(starget);
+ put_device(&starget->dev);
+ out:
+ mutex_unlock(&shost->scan_mutex);
+ return sdev;
+}
+EXPORT_SYMBOL(scsi_get_dev);
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index aa7b7496c93a..5142c7df7647 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -794,7 +794,10 @@ void scsi_host_busy_iter(struct Scsi_Host *,

struct class_container;

+extern struct scsi_device *scsi_get_dev(struct device *parent, int channel, uint id, u64 lun);
+
/*
+
* DIF defines the exchange of protection information between
* initiator and SBC block device.
*
--
2.35.3

2022-09-20 22:03:30

by Damien Le Moal

Subject: Re: [PATCH RFC 3/6] scsi: core: Add scsi_get_dev()

On 9/20/22 19:27, John Garry wrote:
> Add a function which allows use to alloc a sdev with configurable
> device parent, and channel:id:lun.
>
> This is useful for separating adding a scsi device into separate alloc
> and scan steps.
>
> Signed-off-by: John Garry <[email protected]>
> ---
> drivers/scsi/scsi_scan.c | 25 +++++++++++++++++++++++++
> include/scsi/scsi_host.h | 3 +++
> 2 files changed, 28 insertions(+)
>
> diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
> index 3759b1a77504..fd15ddac01b6 100644
> --- a/drivers/scsi/scsi_scan.c
> +++ b/drivers/scsi/scsi_scan.c
> @@ -1988,3 +1988,28 @@ void scsi_forget_host(struct Scsi_Host *shost)
> spin_unlock_irqrestore(shost->host_lock, flags);
> }
>
> +struct scsi_device *scsi_get_dev(struct device *parent, int channel, uint id, u64 lun)
> +{
> + struct Scsi_Host *shost = dev_to_shost(parent);
> + struct scsi_device *sdev = NULL;
> + struct scsi_target *starget;
> +
> + mutex_lock(&shost->scan_mutex);
> + if (!scsi_host_scan_allowed(shost))
> + goto out;
> +
> + starget = scsi_alloc_target(parent, 0, id);
> + if (!starget)
> + goto out;
> +
> + sdev = scsi_alloc_sdev(starget, 0, NULL);
> + if (sdev)
> + sdev->borken = 0;
> + else
> + scsi_target_reap(starget);
> + put_device(&starget->dev);
> + out:
> + mutex_unlock(&shost->scan_mutex);
> + return sdev;
> +}
> +EXPORT_SYMBOL(scsi_get_dev);
> diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
> index aa7b7496c93a..5142c7df7647 100644
> --- a/include/scsi/scsi_host.h
> +++ b/include/scsi/scsi_host.h
> @@ -794,7 +794,10 @@ void scsi_host_busy_iter(struct Scsi_Host *,
>
> struct class_container;
>
> +extern struct scsi_device *scsi_get_dev(struct device *parent, int channel, uint id, u64 lun);

You should not need extern here, and long line...

> +
> /*
> +

white line change.

> * DIF defines the exchange of protection information between
> * initiator and SBC block device.
> *

--
Damien Le Moal
Western Digital Research

2022-09-21 10:19:10

by John Garry

Subject: Re: [PATCH RFC 3/6] scsi: core: Add scsi_get_dev()

On 20/09/2022 22:58, Damien Le Moal wrote:
>> +extern struct scsi_device *scsi_get_dev(struct device *parent, int
>> channel, uint id, u64 lun);
>
> You should not need extern here, and long line...
>
>> +
>>   /*
>> +
>
> white line change.
>
>>    * DIF defines the exchange of protection information between
>>    * initiator and SBC block device.

ok, I'll tidy them.

Thanks,
John