ata: libata-sata: Fix device queue depth control

The function __ata_change_queue_depth() uses the helper
ata_scsi_find_dev() to get the ata_device structure of a scsi device and
set that device maximum queue depth. However, when the ata device is
managed by libsas, ata_scsi_find_dev() returns NULL, turning
__ata_change_queue_depth() into a nop, which prevents the user from
setting the maximum queue depth of ATA devices used with libsas based
HBAs.

Fix this by renaming __ata_change_queue_depth() to
ata_change_queue_depth() and adding a pointer to the ata_device
structure of the target device as argument. This pointer is provided by
ata_scsi_change_queue_depth() using ata_scsi_find_dev() in the case of
a libata managed device and by sas_change_queue_depth() using
sas_to_ata_dev() in the case of a libsas managed ata device.

Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Tested-by: John Garry <john.garry@huawei.com>

diff --git a/drivers/ata/libata-sata.c b/drivers/ata/libata-sata.c
index 7a5fe41..13b9d0f 100644 (file)
--- a/drivers/ata/libata-sata.c
+++ b/drivers/ata/libata-sata.c
@@ -1018,26 +1018,25 @@ DEVICE_ATTR(sw_activity, S_IWUSR | S_IRUGO, ata_scsi_activity_show,
 EXPORT_SYMBOL_GPL(dev_attr_sw_activity);
 
 /**
- *     __ata_change_queue_depth - helper for ata_scsi_change_queue_depth
- *     @ap: ATA port to which the device change the queue depth
+ *     ata_change_queue_depth - Set a device maximum queue depth
+ *     @ap: ATA port of the target device
+ *     @dev: target ATA device
  *     @sdev: SCSI device to configure queue depth for
  *     @queue_depth: new queue depth
  *
- *     libsas and libata have different approaches for associating a sdev to
- *     its ata_port.
+ *     Helper to set a device maximum queue depth, usable with both libsas
+ *     and libata.
  *
  */
-int __ata_change_queue_depth(struct ata_port *ap, struct scsi_device *sdev,
-                            int queue_depth)
+int ata_change_queue_depth(struct ata_port *ap, struct ata_device *dev,
+                          struct scsi_device *sdev, int queue_depth)
 {
-       struct ata_device *dev;
        unsigned long flags;
 
-       if (queue_depth < 1 || queue_depth == sdev->queue_depth)
+       if (!dev || !ata_dev_enabled(dev))
                return sdev->queue_depth;
 
-       dev = ata_scsi_find_dev(ap, sdev);
-       if (!dev || !ata_dev_enabled(dev))
+       if (queue_depth < 1 || queue_depth == sdev->queue_depth)
                return sdev->queue_depth;
 
        /* NCQ enabled? */
@@ -1059,7 +1058,7 @@ int __ata_change_queue_depth(struct ata_port *ap, struct scsi_device *sdev,
 
        return scsi_change_queue_depth(sdev, queue_depth);
 }
-EXPORT_SYMBOL_GPL(__ata_change_queue_depth);
+EXPORT_SYMBOL_GPL(ata_change_queue_depth);
 
 /**
  *     ata_scsi_change_queue_depth - SCSI callback for queue depth config
@@ -1080,7 +1079,8 @@ int ata_scsi_change_queue_depth(struct scsi_device *sdev, int queue_depth)
 {
        struct ata_port *ap = ata_shost_to_port(sdev->host);
 
-       return __ata_change_queue_depth(ap, sdev, queue_depth);
+       return ata_change_queue_depth(ap, ata_scsi_find_dev(ap, sdev),
+                                     sdev, queue_depth);
 }
 EXPORT_SYMBOL_GPL(ata_scsi_change_queue_depth);
 

diff --git a/drivers/scsi/libsas/sas_scsi_host.c b/drivers/scsi/libsas/sas_scsi_host.c
index 9c82e5d..a36fa1c 100644 (file)
--- a/drivers/scsi/libsas/sas_scsi_host.c
+++ b/drivers/scsi/libsas/sas_scsi_host.c
@@ -872,7 +872,8 @@ int sas_change_queue_depth(struct scsi_device *sdev, int depth)
        struct domain_device *dev = sdev_to_domain_dev(sdev);
 
        if (dev_is_sata(dev))
-               return __ata_change_queue_depth(dev->sata_dev.ap, sdev, depth);
+               return ata_change_queue_depth(dev->sata_dev.ap,
+                                             sas_to_ata_dev(dev), sdev, depth);
 
        if (!sdev->tagged_supported)
                depth = 1;

diff --git a/include/linux/libata.h b/include/linux/libata.h
index 698032e..20765d1 100644 (file)
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -1136,8 +1136,8 @@ extern int ata_scsi_slave_config(struct scsi_device *sdev);
 extern void ata_scsi_slave_destroy(struct scsi_device *sdev);
 extern int ata_scsi_change_queue_depth(struct scsi_device *sdev,
                                       int queue_depth);
-extern int __ata_change_queue_depth(struct ata_port *ap, struct scsi_device *sdev,
-                                   int queue_depth);
+extern int ata_change_queue_depth(struct ata_port *ap, struct ata_device *dev,
+                                 struct scsi_device *sdev, int queue_depth);
 extern struct ata_device *ata_dev_pair(struct ata_device *adev);
 extern int ata_do_set_mode(struct ata_link *link, struct ata_device **r_failed_dev);
 extern void ata_scsi_port_error_handler(struct Scsi_Host *host, struct ata_port *ap);