Re: [PATCH] scsi: fix lockdep warning

[James Bottomley <James.Bottomley@suse.de>]

On Sat, 2010-03-20 at 00:17 -0700, Yinghai Lu wrote:
> Index: linux-2.6/drivers/scsi/scsi_sysfs.c
> ===================================================================
> --- linux-2.6.orig/drivers/scsi/scsi_sysfs.c
> +++ linux-2.6/drivers/scsi/scsi_sysfs.c
> @@ -907,20 +907,27 @@ int scsi_sysfs_add_sdev(struct scsi_devi
>  
>         /* create queue files, which may be writable, depending on the
> host */
>         if (sdev->host->hostt->change_queue_depth) {
> +               sysfs_bin_attr_init(&sdev_attr_queue_depth_rw);
>                 error = device_create_file(&sdev->sdev_gendev,
>                                            &sdev_attr_queue_depth_rw);
> +               sysfs_bin_attr_init(&sdev_attr_queue_ramp_up_period);
>                 error = device_create_file(&sdev->sdev_gendev,
> 
> &sdev_attr_queue_ramp_up_period);
>         }
> -       else
> +       else {
> +               sysfs_bin_attr_init(&dev_attr_queue_depth);
>                 error = device_create_file(&sdev->sdev_gendev,
> &dev_attr_queue_depth);
> +       }
>         if (error)
>                 return error;
>  
> -       if (sdev->host->hostt->change_queue_type)
> +       if (sdev->host->hostt->change_queue_type)  {
> +               sysfs_bin_attr_init(&sdev_attr_queue_type_rw);
>                 error = device_create_file(&sdev->sdev_gendev,
> &sdev_attr_queue_type_rw);
> -       else
> +       } else {
> +               sysfs_bin_attr_init(&dev_attr_queue_type);
>                 error = device_create_file(&sdev->sdev_gendev,
> &dev_attr_queue_type);
> +       }
>         if (error)
>                 return error;
>  
> @@ -935,6 +942,7 @@ int scsi_sysfs_add_sdev(struct scsi_devi
>         /* add additional host specific attributes */
>         if (sdev->host->hostt->sdev_attrs) {
>                 for (i = 0; sdev->host->hostt->sdev_attrs[i]; i++) {
> +                       sysfs_bin_attr_init(sdev->host->hostt->sdev_attrs[i]);
>                         error = device_create_file(&sdev->sdev_gendev,
>                                         sdev->host->hostt->sdev_attrs[i]);
>                         if (error)
> @@ -1060,6 +1068,7 @@ int scsi_sysfs_add_host(struct Scsi_Host
>         /* add host specific attributes */
>         if (shost->hostt->shost_attrs) {
>                 for (i = 0; shost->hostt->shost_attrs[i]; i++) {
> +                       sysfs_bin_attr_init(shost->hostt->shost_attrs[i]);
>                         error = device_create_file(&shost->shost_dev,
>                                         shost->hostt->shost_attrs[i]);
>                         if (error)


These are all clearly wrong.  The attribute in question is a device
attribute not a binary attribute.  It only actually compiles because
whoever did sysfs_bin_attr_init() has no type checking on the define and
it just so happens that struct device_attr has a member named attr as
well.

Also, none of these are dynamic attributes, so they shouldn't actually
need initialisation even for lockdep, so what went wrong?

James