On 2023/5/5 17:51, John Garry wrote:
On 05/05/2023 10:14, yangxingui wrote:
hmmm... is it really acceptable that libata is referencing libsas? I
didn't think that it would be. libsas uses libata, not the other way
around.
Yeah, I didn't expect that either. Is there any other way? If so, is
patch v1 OK?
I still think that we can do better than v1.
OK
#include <linux/libata.h>
#include <linux/hdreg.h>
#include <linux/uaccess.h>
@@ -2745,10 +2746,17 @@ static struct ata_device
*__ata_scsi_find_dev(struct ata_port *ap,
* Associated ATA device, or %NULL if not found.
*/
struct ata_device *
-ata_scsi_find_dev(struct ata_port *ap, const struct scsi_device
*scsidev)
Why drop the const ?
+ata_scsi_find_dev(struct ata_port *ap, struct scsi_device *scsidev)
{
- struct ata_device *dev = __ata_scsi_find_dev(ap, scsidev);
+ struct ata_device *dev;
+
+ if (ap->flags & ATA_FLAG_SAS_HOST) {
And this is SAS host. Not necessarily libsas (even though with ipr
libata usage gone, it would be the only user).
Add a new flag only for libsas?
No, because of previous reason.
Please remind me - at what point do we error within ata_scsi_find_dev()
and return NULL for a libsas host?
The scsi_host_template filled by libsas and call ata_scsi_find_dev() has
this problem. After sas_change_queue_depth() is fixed, only sas_ioctl()
has this problem now.
Note: it would be good to include that commit message for future reference.
Maybe we could add a method to ata_port_operations to do this lookup. I
assume that is abusing ata_port_operations purpose, since it's mostly
for HW methods.
Or do we actually use sdev->hostdata for libata or libsas? If not, maybe
we could store the struct ata_device pointer there.
Well, it might be a way.
Thanks,
Xingui
.
I'm just thinking out loud now...
Thanks,
John
.
