Hannes Reinecke wrote:
> If a driver sets blk_queue_prep_rq() it should clean up itself
> and not rely on the bus callbacks to handle this. This removes
> the need to hook into bus->remove() as these should not be used
> at the same time as driver->remove().
>
> Signed-off-by: Hannes Reinecke <hare@xxxxxxx>
> Signed-off-by: Kay Sievers <kay.sievers@xxxxxxxx>
Hi Hannes, please I do not understand this patch.
I was always under the impression that the scsi ULD
remove() function is called from inside scsi_bus_remove()
at the very end, please see below.
> ---
> drivers/scsi/scsi_lib.c | 6 ++++++
> drivers/scsi/scsi_sysfs.c | 17 -----------------
> drivers/scsi/sd.c | 2 ++
> drivers/scsi/sr.c | 1 +
> include/scsi/scsi_driver.h | 1 +
> 5 files changed, 10 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
> index 4b13e36..73df41b 100644
> --- a/drivers/scsi/scsi_lib.c
> +++ b/drivers/scsi/scsi_lib.c
> @@ -1222,6 +1222,12 @@ int scsi_prep_fn(struct request_queue *q, struct request *req)
> return scsi_prep_return(q, req, ret);
> }
>
> +void scsi_reset_prep_fn(struct request_queue *q)
> +{
> + blk_queue_prep_rq(q, scsi_prep_fn);
> +}
> +EXPORT_SYMBOL(scsi_reset_prep_fn);
> +
> /*
> * scsi_dev_queue_ready: if we can send requests to sdev, return 1 else
> * return 0.
> diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
> index fa4711d..91482f2 100644
> --- a/drivers/scsi/scsi_sysfs.c
> +++ b/drivers/scsi/scsi_sysfs.c
> @@ -420,29 +420,12 @@ static int scsi_bus_resume(struct device * dev)
> return err;
> }
>
> -static int scsi_bus_remove(struct device *dev)
> -{
> - struct device_driver *drv = dev->driver;
> - struct scsi_device *sdev = to_scsi_device(dev);
> - int err = 0;
> -
> - /* reset the prep_fn back to the default since the
> - * driver may have altered it and it's being removed */
> - blk_queue_prep_rq(sdev->request_queue, scsi_prep_fn);
> -
> - if (drv && drv->remove)
> - err = drv->remove(dev);
This here is where my osd_uld.c::osd_remove() is called.
If this vector is not used will the drv-core call drv->remove(dev)
in behalf of scsi?
> -
> - return 0;
> -}
> -
> struct bus_type scsi_bus_type = {
> .name = "scsi",
> .match = scsi_bus_match,
> .uevent = scsi_bus_uevent,
> .suspend = scsi_bus_suspend,
> .resume = scsi_bus_resume,
> - .remove = scsi_bus_remove,
> };
> EXPORT_SYMBOL_GPL(scsi_bus_type);
>
> diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
> index aeab5d9..64e88e2 100644
> --- a/drivers/scsi/sd.c
> +++ b/drivers/scsi/sd.c
> @@ -2068,6 +2068,8 @@ static int sd_remove(struct device *dev)
Until today this was called from within scsi_bus_remove
what happens after your patch?
> {
> struct scsi_disk *sdkp = dev_get_drvdata(dev);
>
> + scsi_reset_prep_fn(sdkp->device->request_queue);
> +
> device_del(&sdkp->dev);
> del_gendisk(sdkp->disk);
> sd_shutdown(dev);
> diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c
> index e7fa3ca..914733a 100644
> --- a/drivers/scsi/sr.c
> +++ b/drivers/scsi/sr.c
> @@ -889,6 +889,7 @@ static int sr_remove(struct device *dev)
> {
> struct scsi_cd *cd = dev_get_drvdata(dev);
>
> + scsi_reset_prep_fn(cd->device->request_queue);
> del_gendisk(cd->disk);
>
> mutex_lock(&sr_ref_mutex);
> diff --git a/include/scsi/scsi_driver.h b/include/scsi/scsi_driver.h
> index 1f5ca7f..2e22929 100644
> --- a/include/scsi/scsi_driver.h
> +++ b/include/scsi/scsi_driver.h
> @@ -32,5 +32,6 @@ int scsi_setup_blk_pc_cmnd(struct scsi_device *sdev, struct request *req);
> int scsi_setup_fs_cmnd(struct scsi_device *sdev, struct request *req);
> int scsi_prep_state_check(struct scsi_device *sdev, struct request *req);
> int scsi_prep_return(struct request_queue *q, struct request *req, int ret);
> +int scsi_reset_prep_fn(struct request_queue *);
>
> #endif /* _SCSI_SCSI_DRIVER_H */
I did not test this patch with osd_uld yet, but I will tomorrow. If my assumption
is right then drv-core should call my osd_remove just the same, right?
Are there any different timing issue for example the presence of scsi_device
is still true?
Thanks
Boaz
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